1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *	Linux INET6 implementation
4  *	FIB front-end.
5  *
6  *	Authors:
7  *	Pedro Roque		<roque@di.fc.ul.pt>
8  */
9 
10 /*	Changes:
11  *
12  *	YOSHIFUJI Hideaki @USAGI
13  *		reworked default router selection.
14  *		- respect outgoing interface
15  *		- select from (probably) reachable routers (i.e.
16  *		routers in REACHABLE, STALE, DELAY or PROBE states).
17  *		- always select the same router if it is (probably)
18  *		reachable.  otherwise, round-robin the list.
19  *	Ville Nuorvala
20  *		Fixed routing subtrees.
21  */
22 
23 #define pr_fmt(fmt) "IPv6: " fmt
24 
25 #include <linux/capability.h>
26 #include <linux/errno.h>
27 #include <linux/export.h>
28 #include <linux/types.h>
29 #include <linux/times.h>
30 #include <linux/socket.h>
31 #include <linux/sockios.h>
32 #include <linux/net.h>
33 #include <linux/route.h>
34 #include <linux/netdevice.h>
35 #include <linux/in6.h>
36 #include <linux/mroute6.h>
37 #include <linux/init.h>
38 #include <linux/if_arp.h>
39 #include <linux/proc_fs.h>
40 #include <linux/seq_file.h>
41 #include <linux/nsproxy.h>
42 #include <linux/slab.h>
43 #include <linux/jhash.h>
44 #include <linux/siphash.h>
45 #include <net/net_namespace.h>
46 #include <net/snmp.h>
47 #include <net/ipv6.h>
48 #include <net/ip6_fib.h>
49 #include <net/ip6_route.h>
50 #include <net/ndisc.h>
51 #include <net/addrconf.h>
52 #include <net/tcp.h>
53 #include <linux/rtnetlink.h>
54 #include <net/dst.h>
55 #include <net/dst_metadata.h>
56 #include <net/xfrm.h>
57 #include <net/netevent.h>
58 #include <net/netlink.h>
59 #include <net/rtnh.h>
60 #include <net/lwtunnel.h>
61 #include <net/ip_tunnels.h>
62 #include <net/l3mdev.h>
63 #include <net/ip.h>
64 #include <linux/uaccess.h>
65 #include <linux/btf_ids.h>
66 
67 #ifdef CONFIG_SYSCTL
68 #include <linux/sysctl.h>
69 #endif
70 
71 static int ip6_rt_type_to_error(u8 fib6_type);
72 
73 #define CREATE_TRACE_POINTS
74 #include <trace/events/fib6.h>
75 EXPORT_TRACEPOINT_SYMBOL_GPL(fib6_table_lookup);
76 #undef CREATE_TRACE_POINTS
77 
78 enum rt6_nud_state {
79 	RT6_NUD_FAIL_HARD = -3,
80 	RT6_NUD_FAIL_PROBE = -2,
81 	RT6_NUD_FAIL_DO_RR = -1,
82 	RT6_NUD_SUCCEED = 1
83 };
84 
85 INDIRECT_CALLABLE_SCOPE
86 struct dst_entry	*ip6_dst_check(struct dst_entry *dst, u32 cookie);
87 static unsigned int	 ip6_default_advmss(const struct dst_entry *dst);
88 INDIRECT_CALLABLE_SCOPE
89 unsigned int		ip6_mtu(const struct dst_entry *dst);
90 static struct dst_entry *ip6_negative_advice(struct dst_entry *);
91 static void		ip6_dst_destroy(struct dst_entry *);
92 static void		ip6_dst_ifdown(struct dst_entry *,
93 				       struct net_device *dev);
94 static void		 ip6_dst_gc(struct dst_ops *ops);
95 
96 static int		ip6_pkt_discard(struct sk_buff *skb);
97 static int		ip6_pkt_discard_out(struct net *net, struct sock *sk, struct sk_buff *skb);
98 static int		ip6_pkt_prohibit(struct sk_buff *skb);
99 static int		ip6_pkt_prohibit_out(struct net *net, struct sock *sk, struct sk_buff *skb);
100 static void		ip6_link_failure(struct sk_buff *skb);
101 static void		ip6_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
102 					   struct sk_buff *skb, u32 mtu,
103 					   bool confirm_neigh);
104 static void		rt6_do_redirect(struct dst_entry *dst, struct sock *sk,
105 					struct sk_buff *skb);
106 static int rt6_score_route(const struct fib6_nh *nh, u32 fib6_flags, int oif,
107 			   int strict);
108 static size_t rt6_nlmsg_size(struct fib6_info *f6i);
109 static int rt6_fill_node(struct net *net, struct sk_buff *skb,
110 			 struct fib6_info *rt, struct dst_entry *dst,
111 			 struct in6_addr *dest, struct in6_addr *src,
112 			 int iif, int type, u32 portid, u32 seq,
113 			 unsigned int flags);
114 static struct rt6_info *rt6_find_cached_rt(const struct fib6_result *res,
115 					   const struct in6_addr *daddr,
116 					   const struct in6_addr *saddr);
117 
118 #ifdef CONFIG_IPV6_ROUTE_INFO
119 static struct fib6_info *rt6_add_route_info(struct net *net,
120 					   const struct in6_addr *prefix, int prefixlen,
121 					   const struct in6_addr *gwaddr,
122 					   struct net_device *dev,
123 					   unsigned int pref);
124 static struct fib6_info *rt6_get_route_info(struct net *net,
125 					   const struct in6_addr *prefix, int prefixlen,
126 					   const struct in6_addr *gwaddr,
127 					   struct net_device *dev);
128 #endif
129 
130 struct uncached_list {
131 	spinlock_t		lock;
132 	struct list_head	head;
133 	struct list_head	quarantine;
134 };
135 
136 static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt6_uncached_list);
137 
rt6_uncached_list_add(struct rt6_info * rt)138 void rt6_uncached_list_add(struct rt6_info *rt)
139 {
140 	struct uncached_list *ul = raw_cpu_ptr(&rt6_uncached_list);
141 
142 	rt->dst.rt_uncached_list = ul;
143 
144 	spin_lock_bh(&ul->lock);
145 	list_add_tail(&rt->dst.rt_uncached, &ul->head);
146 	spin_unlock_bh(&ul->lock);
147 }
148 
rt6_uncached_list_del(struct rt6_info * rt)149 void rt6_uncached_list_del(struct rt6_info *rt)
150 {
151 	if (!list_empty(&rt->dst.rt_uncached)) {
152 		struct uncached_list *ul = rt->dst.rt_uncached_list;
153 
154 		spin_lock_bh(&ul->lock);
155 		list_del_init(&rt->dst.rt_uncached);
156 		spin_unlock_bh(&ul->lock);
157 	}
158 }
159 
rt6_uncached_list_flush_dev(struct net_device * dev)160 static void rt6_uncached_list_flush_dev(struct net_device *dev)
161 {
162 	int cpu;
163 
164 	for_each_possible_cpu(cpu) {
165 		struct uncached_list *ul = per_cpu_ptr(&rt6_uncached_list, cpu);
166 		struct rt6_info *rt, *safe;
167 
168 		if (list_empty(&ul->head))
169 			continue;
170 
171 		spin_lock_bh(&ul->lock);
172 		list_for_each_entry_safe(rt, safe, &ul->head, dst.rt_uncached) {
173 			struct inet6_dev *rt_idev = rt->rt6i_idev;
174 			struct net_device *rt_dev = rt->dst.dev;
175 			bool handled = false;
176 
177 			if (rt_idev->dev == dev) {
178 				rt->rt6i_idev = in6_dev_get(blackhole_netdev);
179 				in6_dev_put(rt_idev);
180 				handled = true;
181 			}
182 
183 			if (rt_dev == dev) {
184 				rt->dst.dev = blackhole_netdev;
185 				netdev_ref_replace(rt_dev, blackhole_netdev,
186 						   &rt->dst.dev_tracker,
187 						   GFP_ATOMIC);
188 				handled = true;
189 			}
190 			if (handled)
191 				list_move(&rt->dst.rt_uncached,
192 					  &ul->quarantine);
193 		}
194 		spin_unlock_bh(&ul->lock);
195 	}
196 }
197 
choose_neigh_daddr(const struct in6_addr * p,struct sk_buff * skb,const void * daddr)198 static inline const void *choose_neigh_daddr(const struct in6_addr *p,
199 					     struct sk_buff *skb,
200 					     const void *daddr)
201 {
202 	if (!ipv6_addr_any(p))
203 		return (const void *) p;
204 	else if (skb)
205 		return &ipv6_hdr(skb)->daddr;
206 	return daddr;
207 }
208 
ip6_neigh_lookup(const struct in6_addr * gw,struct net_device * dev,struct sk_buff * skb,const void * daddr)209 struct neighbour *ip6_neigh_lookup(const struct in6_addr *gw,
210 				   struct net_device *dev,
211 				   struct sk_buff *skb,
212 				   const void *daddr)
213 {
214 	struct neighbour *n;
215 
216 	daddr = choose_neigh_daddr(gw, skb, daddr);
217 	n = __ipv6_neigh_lookup(dev, daddr);
218 	if (n)
219 		return n;
220 
221 	n = neigh_create(&nd_tbl, daddr, dev);
222 	return IS_ERR(n) ? NULL : n;
223 }
224 
ip6_dst_neigh_lookup(const struct dst_entry * dst,struct sk_buff * skb,const void * daddr)225 static struct neighbour *ip6_dst_neigh_lookup(const struct dst_entry *dst,
226 					      struct sk_buff *skb,
227 					      const void *daddr)
228 {
229 	const struct rt6_info *rt = container_of(dst, struct rt6_info, dst);
230 
231 	return ip6_neigh_lookup(rt6_nexthop(rt, &in6addr_any),
232 				dst->dev, skb, daddr);
233 }
234 
ip6_confirm_neigh(const struct dst_entry * dst,const void * daddr)235 static void ip6_confirm_neigh(const struct dst_entry *dst, const void *daddr)
236 {
237 	struct net_device *dev = dst->dev;
238 	struct rt6_info *rt = (struct rt6_info *)dst;
239 
240 	daddr = choose_neigh_daddr(rt6_nexthop(rt, &in6addr_any), NULL, daddr);
241 	if (!daddr)
242 		return;
243 	if (dev->flags & (IFF_NOARP | IFF_LOOPBACK))
244 		return;
245 	if (ipv6_addr_is_multicast((const struct in6_addr *)daddr))
246 		return;
247 	__ipv6_confirm_neigh(dev, daddr);
248 }
249 
250 static struct dst_ops ip6_dst_ops_template = {
251 	.family			=	AF_INET6,
252 	.gc			=	ip6_dst_gc,
253 	.gc_thresh		=	1024,
254 	.check			=	ip6_dst_check,
255 	.default_advmss		=	ip6_default_advmss,
256 	.mtu			=	ip6_mtu,
257 	.cow_metrics		=	dst_cow_metrics_generic,
258 	.destroy		=	ip6_dst_destroy,
259 	.ifdown			=	ip6_dst_ifdown,
260 	.negative_advice	=	ip6_negative_advice,
261 	.link_failure		=	ip6_link_failure,
262 	.update_pmtu		=	ip6_rt_update_pmtu,
263 	.redirect		=	rt6_do_redirect,
264 	.local_out		=	__ip6_local_out,
265 	.neigh_lookup		=	ip6_dst_neigh_lookup,
266 	.confirm_neigh		=	ip6_confirm_neigh,
267 };
268 
269 static struct dst_ops ip6_dst_blackhole_ops = {
270 	.family			= AF_INET6,
271 	.default_advmss		= ip6_default_advmss,
272 	.neigh_lookup		= ip6_dst_neigh_lookup,
273 	.check			= ip6_dst_check,
274 	.destroy		= ip6_dst_destroy,
275 	.cow_metrics		= dst_cow_metrics_generic,
276 	.update_pmtu		= dst_blackhole_update_pmtu,
277 	.redirect		= dst_blackhole_redirect,
278 	.mtu			= dst_blackhole_mtu,
279 };
280 
281 static const u32 ip6_template_metrics[RTAX_MAX] = {
282 	[RTAX_HOPLIMIT - 1] = 0,
283 };
284 
285 static const struct fib6_info fib6_null_entry_template = {
286 	.fib6_flags	= (RTF_REJECT | RTF_NONEXTHOP),
287 	.fib6_protocol  = RTPROT_KERNEL,
288 	.fib6_metric	= ~(u32)0,
289 	.fib6_ref	= REFCOUNT_INIT(1),
290 	.fib6_type	= RTN_UNREACHABLE,
291 	.fib6_metrics	= (struct dst_metrics *)&dst_default_metrics,
292 };
293 
294 static const struct rt6_info ip6_null_entry_template = {
295 	.dst = {
296 		.__rcuref	= RCUREF_INIT(1),
297 		.__use		= 1,
298 		.obsolete	= DST_OBSOLETE_FORCE_CHK,
299 		.error		= -ENETUNREACH,
300 		.input		= ip6_pkt_discard,
301 		.output		= ip6_pkt_discard_out,
302 	},
303 	.rt6i_flags	= (RTF_REJECT | RTF_NONEXTHOP),
304 };
305 
306 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
307 
308 static const struct rt6_info ip6_prohibit_entry_template = {
309 	.dst = {
310 		.__rcuref	= RCUREF_INIT(1),
311 		.__use		= 1,
312 		.obsolete	= DST_OBSOLETE_FORCE_CHK,
313 		.error		= -EACCES,
314 		.input		= ip6_pkt_prohibit,
315 		.output		= ip6_pkt_prohibit_out,
316 	},
317 	.rt6i_flags	= (RTF_REJECT | RTF_NONEXTHOP),
318 };
319 
320 static const struct rt6_info ip6_blk_hole_entry_template = {
321 	.dst = {
322 		.__rcuref	= RCUREF_INIT(1),
323 		.__use		= 1,
324 		.obsolete	= DST_OBSOLETE_FORCE_CHK,
325 		.error		= -EINVAL,
326 		.input		= dst_discard,
327 		.output		= dst_discard_out,
328 	},
329 	.rt6i_flags	= (RTF_REJECT | RTF_NONEXTHOP),
330 };
331 
332 #endif
333 
rt6_info_init(struct rt6_info * rt)334 static void rt6_info_init(struct rt6_info *rt)
335 {
336 	memset_after(rt, 0, dst);
337 }
338 
339 /* allocate dst with ip6_dst_ops */
ip6_dst_alloc(struct net * net,struct net_device * dev,int flags)340 struct rt6_info *ip6_dst_alloc(struct net *net, struct net_device *dev,
341 			       int flags)
342 {
343 	struct rt6_info *rt = dst_alloc(&net->ipv6.ip6_dst_ops, dev,
344 					1, DST_OBSOLETE_FORCE_CHK, flags);
345 
346 	if (rt) {
347 		rt6_info_init(rt);
348 		atomic_inc(&net->ipv6.rt6_stats->fib_rt_alloc);
349 	}
350 
351 	return rt;
352 }
353 EXPORT_SYMBOL(ip6_dst_alloc);
354 
ip6_dst_destroy(struct dst_entry * dst)355 static void ip6_dst_destroy(struct dst_entry *dst)
356 {
357 	struct rt6_info *rt = (struct rt6_info *)dst;
358 	struct fib6_info *from;
359 	struct inet6_dev *idev;
360 
361 	ip_dst_metrics_put(dst);
362 	rt6_uncached_list_del(rt);
363 
364 	idev = rt->rt6i_idev;
365 	if (idev) {
366 		rt->rt6i_idev = NULL;
367 		in6_dev_put(idev);
368 	}
369 
370 	from = xchg((__force struct fib6_info **)&rt->from, NULL);
371 	fib6_info_release(from);
372 }
373 
ip6_dst_ifdown(struct dst_entry * dst,struct net_device * dev)374 static void ip6_dst_ifdown(struct dst_entry *dst, struct net_device *dev)
375 {
376 	struct rt6_info *rt = (struct rt6_info *)dst;
377 	struct inet6_dev *idev = rt->rt6i_idev;
378 
379 	if (idev && idev->dev != blackhole_netdev) {
380 		struct inet6_dev *blackhole_idev = in6_dev_get(blackhole_netdev);
381 
382 		if (blackhole_idev) {
383 			rt->rt6i_idev = blackhole_idev;
384 			in6_dev_put(idev);
385 		}
386 	}
387 }
388 
__rt6_check_expired(const struct rt6_info * rt)389 static bool __rt6_check_expired(const struct rt6_info *rt)
390 {
391 	if (rt->rt6i_flags & RTF_EXPIRES)
392 		return time_after(jiffies, rt->dst.expires);
393 	else
394 		return false;
395 }
396 
rt6_check_expired(const struct rt6_info * rt)397 static bool rt6_check_expired(const struct rt6_info *rt)
398 {
399 	struct fib6_info *from;
400 
401 	from = rcu_dereference(rt->from);
402 
403 	if (rt->rt6i_flags & RTF_EXPIRES) {
404 		if (time_after(jiffies, rt->dst.expires))
405 			return true;
406 	} else if (from) {
407 		return rt->dst.obsolete != DST_OBSOLETE_FORCE_CHK ||
408 			fib6_check_expired(from);
409 	}
410 	return false;
411 }
412 
fib6_select_path(const struct net * net,struct fib6_result * res,struct flowi6 * fl6,int oif,bool have_oif_match,const struct sk_buff * skb,int strict)413 void fib6_select_path(const struct net *net, struct fib6_result *res,
414 		      struct flowi6 *fl6, int oif, bool have_oif_match,
415 		      const struct sk_buff *skb, int strict)
416 {
417 	struct fib6_info *sibling, *next_sibling;
418 	struct fib6_info *match = res->f6i;
419 
420 	if (!match->nh && (!match->fib6_nsiblings || have_oif_match))
421 		goto out;
422 
423 	if (match->nh && have_oif_match && res->nh)
424 		return;
425 
426 	if (skb)
427 		IP6CB(skb)->flags |= IP6SKB_MULTIPATH;
428 
429 	/* We might have already computed the hash for ICMPv6 errors. In such
430 	 * case it will always be non-zero. Otherwise now is the time to do it.
431 	 */
432 	if (!fl6->mp_hash &&
433 	    (!match->nh || nexthop_is_multipath(match->nh)))
434 		fl6->mp_hash = rt6_multipath_hash(net, fl6, skb, NULL);
435 
436 	if (unlikely(match->nh)) {
437 		nexthop_path_fib6_result(res, fl6->mp_hash);
438 		return;
439 	}
440 
441 	if (fl6->mp_hash <= atomic_read(&match->fib6_nh->fib_nh_upper_bound))
442 		goto out;
443 
444 	list_for_each_entry_safe(sibling, next_sibling, &match->fib6_siblings,
445 				 fib6_siblings) {
446 		const struct fib6_nh *nh = sibling->fib6_nh;
447 		int nh_upper_bound;
448 
449 		nh_upper_bound = atomic_read(&nh->fib_nh_upper_bound);
450 		if (fl6->mp_hash > nh_upper_bound)
451 			continue;
452 		if (rt6_score_route(nh, sibling->fib6_flags, oif, strict) < 0)
453 			break;
454 		match = sibling;
455 		break;
456 	}
457 
458 out:
459 	res->f6i = match;
460 	res->nh = match->fib6_nh;
461 }
462 
463 /*
464  *	Route lookup. rcu_read_lock() should be held.
465  */
466 
__rt6_device_match(struct net * net,const struct fib6_nh * nh,const struct in6_addr * saddr,int oif,int flags)467 static bool __rt6_device_match(struct net *net, const struct fib6_nh *nh,
468 			       const struct in6_addr *saddr, int oif, int flags)
469 {
470 	const struct net_device *dev;
471 
472 	if (nh->fib_nh_flags & RTNH_F_DEAD)
473 		return false;
474 
475 	dev = nh->fib_nh_dev;
476 	if (oif) {
477 		if (dev->ifindex == oif)
478 			return true;
479 	} else {
480 		if (ipv6_chk_addr(net, saddr, dev,
481 				  flags & RT6_LOOKUP_F_IFACE))
482 			return true;
483 	}
484 
485 	return false;
486 }
487 
488 struct fib6_nh_dm_arg {
489 	struct net		*net;
490 	const struct in6_addr	*saddr;
491 	int			oif;
492 	int			flags;
493 	struct fib6_nh		*nh;
494 };
495 
__rt6_nh_dev_match(struct fib6_nh * nh,void * _arg)496 static int __rt6_nh_dev_match(struct fib6_nh *nh, void *_arg)
497 {
498 	struct fib6_nh_dm_arg *arg = _arg;
499 
500 	arg->nh = nh;
501 	return __rt6_device_match(arg->net, nh, arg->saddr, arg->oif,
502 				  arg->flags);
503 }
504 
505 /* returns fib6_nh from nexthop or NULL */
rt6_nh_dev_match(struct net * net,struct nexthop * nh,struct fib6_result * res,const struct in6_addr * saddr,int oif,int flags)506 static struct fib6_nh *rt6_nh_dev_match(struct net *net, struct nexthop *nh,
507 					struct fib6_result *res,
508 					const struct in6_addr *saddr,
509 					int oif, int flags)
510 {
511 	struct fib6_nh_dm_arg arg = {
512 		.net   = net,
513 		.saddr = saddr,
514 		.oif   = oif,
515 		.flags = flags,
516 	};
517 
518 	if (nexthop_is_blackhole(nh))
519 		return NULL;
520 
521 	if (nexthop_for_each_fib6_nh(nh, __rt6_nh_dev_match, &arg))
522 		return arg.nh;
523 
524 	return NULL;
525 }
526 
rt6_device_match(struct net * net,struct fib6_result * res,const struct in6_addr * saddr,int oif,int flags)527 static void rt6_device_match(struct net *net, struct fib6_result *res,
528 			     const struct in6_addr *saddr, int oif, int flags)
529 {
530 	struct fib6_info *f6i = res->f6i;
531 	struct fib6_info *spf6i;
532 	struct fib6_nh *nh;
533 
534 	if (!oif && ipv6_addr_any(saddr)) {
535 		if (unlikely(f6i->nh)) {
536 			nh = nexthop_fib6_nh(f6i->nh);
537 			if (nexthop_is_blackhole(f6i->nh))
538 				goto out_blackhole;
539 		} else {
540 			nh = f6i->fib6_nh;
541 		}
542 		if (!(nh->fib_nh_flags & RTNH_F_DEAD))
543 			goto out;
544 	}
545 
546 	for (spf6i = f6i; spf6i; spf6i = rcu_dereference(spf6i->fib6_next)) {
547 		bool matched = false;
548 
549 		if (unlikely(spf6i->nh)) {
550 			nh = rt6_nh_dev_match(net, spf6i->nh, res, saddr,
551 					      oif, flags);
552 			if (nh)
553 				matched = true;
554 		} else {
555 			nh = spf6i->fib6_nh;
556 			if (__rt6_device_match(net, nh, saddr, oif, flags))
557 				matched = true;
558 		}
559 		if (matched) {
560 			res->f6i = spf6i;
561 			goto out;
562 		}
563 	}
564 
565 	if (oif && flags & RT6_LOOKUP_F_IFACE) {
566 		res->f6i = net->ipv6.fib6_null_entry;
567 		nh = res->f6i->fib6_nh;
568 		goto out;
569 	}
570 
571 	if (unlikely(f6i->nh)) {
572 		nh = nexthop_fib6_nh(f6i->nh);
573 		if (nexthop_is_blackhole(f6i->nh))
574 			goto out_blackhole;
575 	} else {
576 		nh = f6i->fib6_nh;
577 	}
578 
579 	if (nh->fib_nh_flags & RTNH_F_DEAD) {
580 		res->f6i = net->ipv6.fib6_null_entry;
581 		nh = res->f6i->fib6_nh;
582 	}
583 out:
584 	res->nh = nh;
585 	res->fib6_type = res->f6i->fib6_type;
586 	res->fib6_flags = res->f6i->fib6_flags;
587 	return;
588 
589 out_blackhole:
590 	res->fib6_flags |= RTF_REJECT;
591 	res->fib6_type = RTN_BLACKHOLE;
592 	res->nh = nh;
593 }
594 
595 #ifdef CONFIG_IPV6_ROUTER_PREF
596 struct __rt6_probe_work {
597 	struct work_struct work;
598 	struct in6_addr target;
599 	struct net_device *dev;
600 	netdevice_tracker dev_tracker;
601 };
602 
rt6_probe_deferred(struct work_struct * w)603 static void rt6_probe_deferred(struct work_struct *w)
604 {
605 	struct in6_addr mcaddr;
606 	struct __rt6_probe_work *work =
607 		container_of(w, struct __rt6_probe_work, work);
608 
609 	addrconf_addr_solict_mult(&work->target, &mcaddr);
610 	ndisc_send_ns(work->dev, &work->target, &mcaddr, NULL, 0);
611 	netdev_put(work->dev, &work->dev_tracker);
612 	kfree(work);
613 }
614 
rt6_probe(struct fib6_nh * fib6_nh)615 static void rt6_probe(struct fib6_nh *fib6_nh)
616 {
617 	struct __rt6_probe_work *work = NULL;
618 	const struct in6_addr *nh_gw;
619 	unsigned long last_probe;
620 	struct neighbour *neigh;
621 	struct net_device *dev;
622 	struct inet6_dev *idev;
623 
624 	/*
625 	 * Okay, this does not seem to be appropriate
626 	 * for now, however, we need to check if it
627 	 * is really so; aka Router Reachability Probing.
628 	 *
629 	 * Router Reachability Probe MUST be rate-limited
630 	 * to no more than one per minute.
631 	 */
632 	if (!fib6_nh->fib_nh_gw_family)
633 		return;
634 
635 	nh_gw = &fib6_nh->fib_nh_gw6;
636 	dev = fib6_nh->fib_nh_dev;
637 	rcu_read_lock();
638 	last_probe = READ_ONCE(fib6_nh->last_probe);
639 	idev = __in6_dev_get(dev);
640 	neigh = __ipv6_neigh_lookup_noref(dev, nh_gw);
641 	if (neigh) {
642 		if (READ_ONCE(neigh->nud_state) & NUD_VALID)
643 			goto out;
644 
645 		write_lock_bh(&neigh->lock);
646 		if (!(neigh->nud_state & NUD_VALID) &&
647 		    time_after(jiffies,
648 			       neigh->updated + idev->cnf.rtr_probe_interval)) {
649 			work = kmalloc(sizeof(*work), GFP_ATOMIC);
650 			if (work)
651 				__neigh_set_probe_once(neigh);
652 		}
653 		write_unlock_bh(&neigh->lock);
654 	} else if (time_after(jiffies, last_probe +
655 				       idev->cnf.rtr_probe_interval)) {
656 		work = kmalloc(sizeof(*work), GFP_ATOMIC);
657 	}
658 
659 	if (!work || cmpxchg(&fib6_nh->last_probe,
660 			     last_probe, jiffies) != last_probe) {
661 		kfree(work);
662 	} else {
663 		INIT_WORK(&work->work, rt6_probe_deferred);
664 		work->target = *nh_gw;
665 		netdev_hold(dev, &work->dev_tracker, GFP_ATOMIC);
666 		work->dev = dev;
667 		schedule_work(&work->work);
668 	}
669 
670 out:
671 	rcu_read_unlock();
672 }
673 #else
rt6_probe(struct fib6_nh * fib6_nh)674 static inline void rt6_probe(struct fib6_nh *fib6_nh)
675 {
676 }
677 #endif
678 
679 /*
680  * Default Router Selection (RFC 2461 6.3.6)
681  */
rt6_check_neigh(const struct fib6_nh * fib6_nh)682 static enum rt6_nud_state rt6_check_neigh(const struct fib6_nh *fib6_nh)
683 {
684 	enum rt6_nud_state ret = RT6_NUD_FAIL_HARD;
685 	struct neighbour *neigh;
686 
687 	rcu_read_lock();
688 	neigh = __ipv6_neigh_lookup_noref(fib6_nh->fib_nh_dev,
689 					  &fib6_nh->fib_nh_gw6);
690 	if (neigh) {
691 		u8 nud_state = READ_ONCE(neigh->nud_state);
692 
693 		if (nud_state & NUD_VALID)
694 			ret = RT6_NUD_SUCCEED;
695 #ifdef CONFIG_IPV6_ROUTER_PREF
696 		else if (!(nud_state & NUD_FAILED))
697 			ret = RT6_NUD_SUCCEED;
698 		else
699 			ret = RT6_NUD_FAIL_PROBE;
700 #endif
701 	} else {
702 		ret = IS_ENABLED(CONFIG_IPV6_ROUTER_PREF) ?
703 		      RT6_NUD_SUCCEED : RT6_NUD_FAIL_DO_RR;
704 	}
705 	rcu_read_unlock();
706 
707 	return ret;
708 }
709 
rt6_score_route(const struct fib6_nh * nh,u32 fib6_flags,int oif,int strict)710 static int rt6_score_route(const struct fib6_nh *nh, u32 fib6_flags, int oif,
711 			   int strict)
712 {
713 	int m = 0;
714 
715 	if (!oif || nh->fib_nh_dev->ifindex == oif)
716 		m = 2;
717 
718 	if (!m && (strict & RT6_LOOKUP_F_IFACE))
719 		return RT6_NUD_FAIL_HARD;
720 #ifdef CONFIG_IPV6_ROUTER_PREF
721 	m |= IPV6_DECODE_PREF(IPV6_EXTRACT_PREF(fib6_flags)) << 2;
722 #endif
723 	if ((strict & RT6_LOOKUP_F_REACHABLE) &&
724 	    !(fib6_flags & RTF_NONEXTHOP) && nh->fib_nh_gw_family) {
725 		int n = rt6_check_neigh(nh);
726 		if (n < 0)
727 			return n;
728 	}
729 	return m;
730 }
731 
find_match(struct fib6_nh * nh,u32 fib6_flags,int oif,int strict,int * mpri,bool * do_rr)732 static bool find_match(struct fib6_nh *nh, u32 fib6_flags,
733 		       int oif, int strict, int *mpri, bool *do_rr)
734 {
735 	bool match_do_rr = false;
736 	bool rc = false;
737 	int m;
738 
739 	if (nh->fib_nh_flags & RTNH_F_DEAD)
740 		goto out;
741 
742 	if (ip6_ignore_linkdown(nh->fib_nh_dev) &&
743 	    nh->fib_nh_flags & RTNH_F_LINKDOWN &&
744 	    !(strict & RT6_LOOKUP_F_IGNORE_LINKSTATE))
745 		goto out;
746 
747 	m = rt6_score_route(nh, fib6_flags, oif, strict);
748 	if (m == RT6_NUD_FAIL_DO_RR) {
749 		match_do_rr = true;
750 		m = 0; /* lowest valid score */
751 	} else if (m == RT6_NUD_FAIL_HARD) {
752 		goto out;
753 	}
754 
755 	if (strict & RT6_LOOKUP_F_REACHABLE)
756 		rt6_probe(nh);
757 
758 	/* note that m can be RT6_NUD_FAIL_PROBE at this point */
759 	if (m > *mpri) {
760 		*do_rr = match_do_rr;
761 		*mpri = m;
762 		rc = true;
763 	}
764 out:
765 	return rc;
766 }
767 
768 struct fib6_nh_frl_arg {
769 	u32		flags;
770 	int		oif;
771 	int		strict;
772 	int		*mpri;
773 	bool		*do_rr;
774 	struct fib6_nh	*nh;
775 };
776 
rt6_nh_find_match(struct fib6_nh * nh,void * _arg)777 static int rt6_nh_find_match(struct fib6_nh *nh, void *_arg)
778 {
779 	struct fib6_nh_frl_arg *arg = _arg;
780 
781 	arg->nh = nh;
782 	return find_match(nh, arg->flags, arg->oif, arg->strict,
783 			  arg->mpri, arg->do_rr);
784 }
785 
__find_rr_leaf(struct fib6_info * f6i_start,struct fib6_info * nomatch,u32 metric,struct fib6_result * res,struct fib6_info ** cont,int oif,int strict,bool * do_rr,int * mpri)786 static void __find_rr_leaf(struct fib6_info *f6i_start,
787 			   struct fib6_info *nomatch, u32 metric,
788 			   struct fib6_result *res, struct fib6_info **cont,
789 			   int oif, int strict, bool *do_rr, int *mpri)
790 {
791 	struct fib6_info *f6i;
792 
793 	for (f6i = f6i_start;
794 	     f6i && f6i != nomatch;
795 	     f6i = rcu_dereference(f6i->fib6_next)) {
796 		bool matched = false;
797 		struct fib6_nh *nh;
798 
799 		if (cont && f6i->fib6_metric != metric) {
800 			*cont = f6i;
801 			return;
802 		}
803 
804 		if (fib6_check_expired(f6i))
805 			continue;
806 
807 		if (unlikely(f6i->nh)) {
808 			struct fib6_nh_frl_arg arg = {
809 				.flags  = f6i->fib6_flags,
810 				.oif    = oif,
811 				.strict = strict,
812 				.mpri   = mpri,
813 				.do_rr  = do_rr
814 			};
815 
816 			if (nexthop_is_blackhole(f6i->nh)) {
817 				res->fib6_flags = RTF_REJECT;
818 				res->fib6_type = RTN_BLACKHOLE;
819 				res->f6i = f6i;
820 				res->nh = nexthop_fib6_nh(f6i->nh);
821 				return;
822 			}
823 			if (nexthop_for_each_fib6_nh(f6i->nh, rt6_nh_find_match,
824 						     &arg)) {
825 				matched = true;
826 				nh = arg.nh;
827 			}
828 		} else {
829 			nh = f6i->fib6_nh;
830 			if (find_match(nh, f6i->fib6_flags, oif, strict,
831 				       mpri, do_rr))
832 				matched = true;
833 		}
834 		if (matched) {
835 			res->f6i = f6i;
836 			res->nh = nh;
837 			res->fib6_flags = f6i->fib6_flags;
838 			res->fib6_type = f6i->fib6_type;
839 		}
840 	}
841 }
842 
find_rr_leaf(struct fib6_node * fn,struct fib6_info * leaf,struct fib6_info * rr_head,int oif,int strict,bool * do_rr,struct fib6_result * res)843 static void find_rr_leaf(struct fib6_node *fn, struct fib6_info *leaf,
844 			 struct fib6_info *rr_head, int oif, int strict,
845 			 bool *do_rr, struct fib6_result *res)
846 {
847 	u32 metric = rr_head->fib6_metric;
848 	struct fib6_info *cont = NULL;
849 	int mpri = -1;
850 
851 	__find_rr_leaf(rr_head, NULL, metric, res, &cont,
852 		       oif, strict, do_rr, &mpri);
853 
854 	__find_rr_leaf(leaf, rr_head, metric, res, &cont,
855 		       oif, strict, do_rr, &mpri);
856 
857 	if (res->f6i || !cont)
858 		return;
859 
860 	__find_rr_leaf(cont, NULL, metric, res, NULL,
861 		       oif, strict, do_rr, &mpri);
862 }
863 
rt6_select(struct net * net,struct fib6_node * fn,int oif,struct fib6_result * res,int strict)864 static void rt6_select(struct net *net, struct fib6_node *fn, int oif,
865 		       struct fib6_result *res, int strict)
866 {
867 	struct fib6_info *leaf = rcu_dereference(fn->leaf);
868 	struct fib6_info *rt0;
869 	bool do_rr = false;
870 	int key_plen;
871 
872 	/* make sure this function or its helpers sets f6i */
873 	res->f6i = NULL;
874 
875 	if (!leaf || leaf == net->ipv6.fib6_null_entry)
876 		goto out;
877 
878 	rt0 = rcu_dereference(fn->rr_ptr);
879 	if (!rt0)
880 		rt0 = leaf;
881 
882 	/* Double check to make sure fn is not an intermediate node
883 	 * and fn->leaf does not points to its child's leaf
884 	 * (This might happen if all routes under fn are deleted from
885 	 * the tree and fib6_repair_tree() is called on the node.)
886 	 */
887 	key_plen = rt0->fib6_dst.plen;
888 #ifdef CONFIG_IPV6_SUBTREES
889 	if (rt0->fib6_src.plen)
890 		key_plen = rt0->fib6_src.plen;
891 #endif
892 	if (fn->fn_bit != key_plen)
893 		goto out;
894 
895 	find_rr_leaf(fn, leaf, rt0, oif, strict, &do_rr, res);
896 	if (do_rr) {
897 		struct fib6_info *next = rcu_dereference(rt0->fib6_next);
898 
899 		/* no entries matched; do round-robin */
900 		if (!next || next->fib6_metric != rt0->fib6_metric)
901 			next = leaf;
902 
903 		if (next != rt0) {
904 			spin_lock_bh(&leaf->fib6_table->tb6_lock);
905 			/* make sure next is not being deleted from the tree */
906 			if (next->fib6_node)
907 				rcu_assign_pointer(fn->rr_ptr, next);
908 			spin_unlock_bh(&leaf->fib6_table->tb6_lock);
909 		}
910 	}
911 
912 out:
913 	if (!res->f6i) {
914 		res->f6i = net->ipv6.fib6_null_entry;
915 		res->nh = res->f6i->fib6_nh;
916 		res->fib6_flags = res->f6i->fib6_flags;
917 		res->fib6_type = res->f6i->fib6_type;
918 	}
919 }
920 
rt6_is_gw_or_nonexthop(const struct fib6_result * res)921 static bool rt6_is_gw_or_nonexthop(const struct fib6_result *res)
922 {
923 	return (res->f6i->fib6_flags & RTF_NONEXTHOP) ||
924 	       res->nh->fib_nh_gw_family;
925 }
926 
927 #ifdef CONFIG_IPV6_ROUTE_INFO
rt6_route_rcv(struct net_device * dev,u8 * opt,int len,const struct in6_addr * gwaddr)928 int rt6_route_rcv(struct net_device *dev, u8 *opt, int len,
929 		  const struct in6_addr *gwaddr)
930 {
931 	struct net *net = dev_net(dev);
932 	struct route_info *rinfo = (struct route_info *) opt;
933 	struct in6_addr prefix_buf, *prefix;
934 	unsigned int pref;
935 	unsigned long lifetime;
936 	struct fib6_info *rt;
937 
938 	if (len < sizeof(struct route_info)) {
939 		return -EINVAL;
940 	}
941 
942 	/* Sanity check for prefix_len and length */
943 	if (rinfo->length > 3) {
944 		return -EINVAL;
945 	} else if (rinfo->prefix_len > 128) {
946 		return -EINVAL;
947 	} else if (rinfo->prefix_len > 64) {
948 		if (rinfo->length < 2) {
949 			return -EINVAL;
950 		}
951 	} else if (rinfo->prefix_len > 0) {
952 		if (rinfo->length < 1) {
953 			return -EINVAL;
954 		}
955 	}
956 
957 	pref = rinfo->route_pref;
958 	if (pref == ICMPV6_ROUTER_PREF_INVALID)
959 		return -EINVAL;
960 
961 	lifetime = addrconf_timeout_fixup(ntohl(rinfo->lifetime), HZ);
962 
963 	if (rinfo->length == 3)
964 		prefix = (struct in6_addr *)rinfo->prefix;
965 	else {
966 		/* this function is safe */
967 		ipv6_addr_prefix(&prefix_buf,
968 				 (struct in6_addr *)rinfo->prefix,
969 				 rinfo->prefix_len);
970 		prefix = &prefix_buf;
971 	}
972 
973 	if (rinfo->prefix_len == 0)
974 		rt = rt6_get_dflt_router(net, gwaddr, dev);
975 	else
976 		rt = rt6_get_route_info(net, prefix, rinfo->prefix_len,
977 					gwaddr, dev);
978 
979 	if (rt && !lifetime) {
980 		ip6_del_rt(net, rt, false);
981 		rt = NULL;
982 	}
983 
984 	if (!rt && lifetime)
985 		rt = rt6_add_route_info(net, prefix, rinfo->prefix_len, gwaddr,
986 					dev, pref);
987 	else if (rt)
988 		rt->fib6_flags = RTF_ROUTEINFO |
989 				 (rt->fib6_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
990 
991 	if (rt) {
992 		if (!addrconf_finite_timeout(lifetime))
993 			fib6_clean_expires(rt);
994 		else
995 			fib6_set_expires(rt, jiffies + HZ * lifetime);
996 
997 		fib6_info_release(rt);
998 	}
999 	return 0;
1000 }
1001 #endif
1002 
1003 /*
1004  *	Misc support functions
1005  */
1006 
1007 /* called with rcu_lock held */
ip6_rt_get_dev_rcu(const struct fib6_result * res)1008 static struct net_device *ip6_rt_get_dev_rcu(const struct fib6_result *res)
1009 {
1010 	struct net_device *dev = res->nh->fib_nh_dev;
1011 
1012 	if (res->fib6_flags & (RTF_LOCAL | RTF_ANYCAST)) {
1013 		/* for copies of local routes, dst->dev needs to be the
1014 		 * device if it is a master device, the master device if
1015 		 * device is enslaved, and the loopback as the default
1016 		 */
1017 		if (netif_is_l3_slave(dev) &&
1018 		    !rt6_need_strict(&res->f6i->fib6_dst.addr))
1019 			dev = l3mdev_master_dev_rcu(dev);
1020 		else if (!netif_is_l3_master(dev))
1021 			dev = dev_net(dev)->loopback_dev;
1022 		/* last case is netif_is_l3_master(dev) is true in which
1023 		 * case we want dev returned to be dev
1024 		 */
1025 	}
1026 
1027 	return dev;
1028 }
1029 
1030 static const int fib6_prop[RTN_MAX + 1] = {
1031 	[RTN_UNSPEC]	= 0,
1032 	[RTN_UNICAST]	= 0,
1033 	[RTN_LOCAL]	= 0,
1034 	[RTN_BROADCAST]	= 0,
1035 	[RTN_ANYCAST]	= 0,
1036 	[RTN_MULTICAST]	= 0,
1037 	[RTN_BLACKHOLE]	= -EINVAL,
1038 	[RTN_UNREACHABLE] = -EHOSTUNREACH,
1039 	[RTN_PROHIBIT]	= -EACCES,
1040 	[RTN_THROW]	= -EAGAIN,
1041 	[RTN_NAT]	= -EINVAL,
1042 	[RTN_XRESOLVE]	= -EINVAL,
1043 };
1044 
ip6_rt_type_to_error(u8 fib6_type)1045 static int ip6_rt_type_to_error(u8 fib6_type)
1046 {
1047 	return fib6_prop[fib6_type];
1048 }
1049 
fib6_info_dst_flags(struct fib6_info * rt)1050 static unsigned short fib6_info_dst_flags(struct fib6_info *rt)
1051 {
1052 	unsigned short flags = 0;
1053 
1054 	if (rt->dst_nocount)
1055 		flags |= DST_NOCOUNT;
1056 	if (rt->dst_nopolicy)
1057 		flags |= DST_NOPOLICY;
1058 
1059 	return flags;
1060 }
1061 
ip6_rt_init_dst_reject(struct rt6_info * rt,u8 fib6_type)1062 static void ip6_rt_init_dst_reject(struct rt6_info *rt, u8 fib6_type)
1063 {
1064 	rt->dst.error = ip6_rt_type_to_error(fib6_type);
1065 
1066 	switch (fib6_type) {
1067 	case RTN_BLACKHOLE:
1068 		rt->dst.output = dst_discard_out;
1069 		rt->dst.input = dst_discard;
1070 		break;
1071 	case RTN_PROHIBIT:
1072 		rt->dst.output = ip6_pkt_prohibit_out;
1073 		rt->dst.input = ip6_pkt_prohibit;
1074 		break;
1075 	case RTN_THROW:
1076 	case RTN_UNREACHABLE:
1077 	default:
1078 		rt->dst.output = ip6_pkt_discard_out;
1079 		rt->dst.input = ip6_pkt_discard;
1080 		break;
1081 	}
1082 }
1083 
ip6_rt_init_dst(struct rt6_info * rt,const struct fib6_result * res)1084 static void ip6_rt_init_dst(struct rt6_info *rt, const struct fib6_result *res)
1085 {
1086 	struct fib6_info *f6i = res->f6i;
1087 
1088 	if (res->fib6_flags & RTF_REJECT) {
1089 		ip6_rt_init_dst_reject(rt, res->fib6_type);
1090 		return;
1091 	}
1092 
1093 	rt->dst.error = 0;
1094 	rt->dst.output = ip6_output;
1095 
1096 	if (res->fib6_type == RTN_LOCAL || res->fib6_type == RTN_ANYCAST) {
1097 		rt->dst.input = ip6_input;
1098 	} else if (ipv6_addr_type(&f6i->fib6_dst.addr) & IPV6_ADDR_MULTICAST) {
1099 		rt->dst.input = ip6_mc_input;
1100 	} else {
1101 		rt->dst.input = ip6_forward;
1102 	}
1103 
1104 	if (res->nh->fib_nh_lws) {
1105 		rt->dst.lwtstate = lwtstate_get(res->nh->fib_nh_lws);
1106 		lwtunnel_set_redirect(&rt->dst);
1107 	}
1108 
1109 	rt->dst.lastuse = jiffies;
1110 }
1111 
1112 /* Caller must already hold reference to @from */
rt6_set_from(struct rt6_info * rt,struct fib6_info * from)1113 static void rt6_set_from(struct rt6_info *rt, struct fib6_info *from)
1114 {
1115 	rt->rt6i_flags &= ~RTF_EXPIRES;
1116 	rcu_assign_pointer(rt->from, from);
1117 	ip_dst_init_metrics(&rt->dst, from->fib6_metrics);
1118 }
1119 
1120 /* Caller must already hold reference to f6i in result */
ip6_rt_copy_init(struct rt6_info * rt,const struct fib6_result * res)1121 static void ip6_rt_copy_init(struct rt6_info *rt, const struct fib6_result *res)
1122 {
1123 	const struct fib6_nh *nh = res->nh;
1124 	const struct net_device *dev = nh->fib_nh_dev;
1125 	struct fib6_info *f6i = res->f6i;
1126 
1127 	ip6_rt_init_dst(rt, res);
1128 
1129 	rt->rt6i_dst = f6i->fib6_dst;
1130 	rt->rt6i_idev = dev ? in6_dev_get(dev) : NULL;
1131 	rt->rt6i_flags = res->fib6_flags;
1132 	if (nh->fib_nh_gw_family) {
1133 		rt->rt6i_gateway = nh->fib_nh_gw6;
1134 		rt->rt6i_flags |= RTF_GATEWAY;
1135 	}
1136 	rt6_set_from(rt, f6i);
1137 #ifdef CONFIG_IPV6_SUBTREES
1138 	rt->rt6i_src = f6i->fib6_src;
1139 #endif
1140 }
1141 
fib6_backtrack(struct fib6_node * fn,struct in6_addr * saddr)1142 static struct fib6_node* fib6_backtrack(struct fib6_node *fn,
1143 					struct in6_addr *saddr)
1144 {
1145 	struct fib6_node *pn, *sn;
1146 	while (1) {
1147 		if (fn->fn_flags & RTN_TL_ROOT)
1148 			return NULL;
1149 		pn = rcu_dereference(fn->parent);
1150 		sn = FIB6_SUBTREE(pn);
1151 		if (sn && sn != fn)
1152 			fn = fib6_node_lookup(sn, NULL, saddr);
1153 		else
1154 			fn = pn;
1155 		if (fn->fn_flags & RTN_RTINFO)
1156 			return fn;
1157 	}
1158 }
1159 
ip6_hold_safe(struct net * net,struct rt6_info ** prt)1160 static bool ip6_hold_safe(struct net *net, struct rt6_info **prt)
1161 {
1162 	struct rt6_info *rt = *prt;
1163 
1164 	if (dst_hold_safe(&rt->dst))
1165 		return true;
1166 	if (net) {
1167 		rt = net->ipv6.ip6_null_entry;
1168 		dst_hold(&rt->dst);
1169 	} else {
1170 		rt = NULL;
1171 	}
1172 	*prt = rt;
1173 	return false;
1174 }
1175 
1176 /* called with rcu_lock held */
ip6_create_rt_rcu(const struct fib6_result * res)1177 static struct rt6_info *ip6_create_rt_rcu(const struct fib6_result *res)
1178 {
1179 	struct net_device *dev = res->nh->fib_nh_dev;
1180 	struct fib6_info *f6i = res->f6i;
1181 	unsigned short flags;
1182 	struct rt6_info *nrt;
1183 
1184 	if (!fib6_info_hold_safe(f6i))
1185 		goto fallback;
1186 
1187 	flags = fib6_info_dst_flags(f6i);
1188 	nrt = ip6_dst_alloc(dev_net(dev), dev, flags);
1189 	if (!nrt) {
1190 		fib6_info_release(f6i);
1191 		goto fallback;
1192 	}
1193 
1194 	ip6_rt_copy_init(nrt, res);
1195 	return nrt;
1196 
1197 fallback:
1198 	nrt = dev_net(dev)->ipv6.ip6_null_entry;
1199 	dst_hold(&nrt->dst);
1200 	return nrt;
1201 }
1202 
ip6_pol_route_lookup(struct net * net,struct fib6_table * table,struct flowi6 * fl6,const struct sk_buff * skb,int flags)1203 INDIRECT_CALLABLE_SCOPE struct rt6_info *ip6_pol_route_lookup(struct net *net,
1204 					     struct fib6_table *table,
1205 					     struct flowi6 *fl6,
1206 					     const struct sk_buff *skb,
1207 					     int flags)
1208 {
1209 	struct fib6_result res = {};
1210 	struct fib6_node *fn;
1211 	struct rt6_info *rt;
1212 
1213 	rcu_read_lock();
1214 	fn = fib6_node_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr);
1215 restart:
1216 	res.f6i = rcu_dereference(fn->leaf);
1217 	if (!res.f6i)
1218 		res.f6i = net->ipv6.fib6_null_entry;
1219 	else
1220 		rt6_device_match(net, &res, &fl6->saddr, fl6->flowi6_oif,
1221 				 flags);
1222 
1223 	if (res.f6i == net->ipv6.fib6_null_entry) {
1224 		fn = fib6_backtrack(fn, &fl6->saddr);
1225 		if (fn)
1226 			goto restart;
1227 
1228 		rt = net->ipv6.ip6_null_entry;
1229 		dst_hold(&rt->dst);
1230 		goto out;
1231 	} else if (res.fib6_flags & RTF_REJECT) {
1232 		goto do_create;
1233 	}
1234 
1235 	fib6_select_path(net, &res, fl6, fl6->flowi6_oif,
1236 			 fl6->flowi6_oif != 0, skb, flags);
1237 
1238 	/* Search through exception table */
1239 	rt = rt6_find_cached_rt(&res, &fl6->daddr, &fl6->saddr);
1240 	if (rt) {
1241 		if (ip6_hold_safe(net, &rt))
1242 			dst_use_noref(&rt->dst, jiffies);
1243 	} else {
1244 do_create:
1245 		rt = ip6_create_rt_rcu(&res);
1246 	}
1247 
1248 out:
1249 	trace_fib6_table_lookup(net, &res, table, fl6);
1250 
1251 	rcu_read_unlock();
1252 
1253 	return rt;
1254 }
1255 
ip6_route_lookup(struct net * net,struct flowi6 * fl6,const struct sk_buff * skb,int flags)1256 struct dst_entry *ip6_route_lookup(struct net *net, struct flowi6 *fl6,
1257 				   const struct sk_buff *skb, int flags)
1258 {
1259 	return fib6_rule_lookup(net, fl6, skb, flags, ip6_pol_route_lookup);
1260 }
1261 EXPORT_SYMBOL_GPL(ip6_route_lookup);
1262 
rt6_lookup(struct net * net,const struct in6_addr * daddr,const struct in6_addr * saddr,int oif,const struct sk_buff * skb,int strict)1263 struct rt6_info *rt6_lookup(struct net *net, const struct in6_addr *daddr,
1264 			    const struct in6_addr *saddr, int oif,
1265 			    const struct sk_buff *skb, int strict)
1266 {
1267 	struct flowi6 fl6 = {
1268 		.flowi6_oif = oif,
1269 		.daddr = *daddr,
1270 	};
1271 	struct dst_entry *dst;
1272 	int flags = strict ? RT6_LOOKUP_F_IFACE : 0;
1273 
1274 	if (saddr) {
1275 		memcpy(&fl6.saddr, saddr, sizeof(*saddr));
1276 		flags |= RT6_LOOKUP_F_HAS_SADDR;
1277 	}
1278 
1279 	dst = fib6_rule_lookup(net, &fl6, skb, flags, ip6_pol_route_lookup);
1280 	if (dst->error == 0)
1281 		return (struct rt6_info *) dst;
1282 
1283 	dst_release(dst);
1284 
1285 	return NULL;
1286 }
1287 EXPORT_SYMBOL(rt6_lookup);
1288 
1289 /* ip6_ins_rt is called with FREE table->tb6_lock.
1290  * It takes new route entry, the addition fails by any reason the
1291  * route is released.
1292  * Caller must hold dst before calling it.
1293  */
1294 
__ip6_ins_rt(struct fib6_info * rt,struct nl_info * info,struct netlink_ext_ack * extack)1295 static int __ip6_ins_rt(struct fib6_info *rt, struct nl_info *info,
1296 			struct netlink_ext_ack *extack)
1297 {
1298 	int err;
1299 	struct fib6_table *table;
1300 
1301 	table = rt->fib6_table;
1302 	spin_lock_bh(&table->tb6_lock);
1303 	err = fib6_add(&table->tb6_root, rt, info, extack);
1304 	spin_unlock_bh(&table->tb6_lock);
1305 
1306 	return err;
1307 }
1308 
ip6_ins_rt(struct net * net,struct fib6_info * rt)1309 int ip6_ins_rt(struct net *net, struct fib6_info *rt)
1310 {
1311 	struct nl_info info = {	.nl_net = net, };
1312 
1313 	return __ip6_ins_rt(rt, &info, NULL);
1314 }
1315 
ip6_rt_cache_alloc(const struct fib6_result * res,const struct in6_addr * daddr,const struct in6_addr * saddr)1316 static struct rt6_info *ip6_rt_cache_alloc(const struct fib6_result *res,
1317 					   const struct in6_addr *daddr,
1318 					   const struct in6_addr *saddr)
1319 {
1320 	struct fib6_info *f6i = res->f6i;
1321 	struct net_device *dev;
1322 	struct rt6_info *rt;
1323 
1324 	/*
1325 	 *	Clone the route.
1326 	 */
1327 
1328 	if (!fib6_info_hold_safe(f6i))
1329 		return NULL;
1330 
1331 	dev = ip6_rt_get_dev_rcu(res);
1332 	rt = ip6_dst_alloc(dev_net(dev), dev, 0);
1333 	if (!rt) {
1334 		fib6_info_release(f6i);
1335 		return NULL;
1336 	}
1337 
1338 	ip6_rt_copy_init(rt, res);
1339 	rt->rt6i_flags |= RTF_CACHE;
1340 	rt->rt6i_dst.addr = *daddr;
1341 	rt->rt6i_dst.plen = 128;
1342 
1343 	if (!rt6_is_gw_or_nonexthop(res)) {
1344 		if (f6i->fib6_dst.plen != 128 &&
1345 		    ipv6_addr_equal(&f6i->fib6_dst.addr, daddr))
1346 			rt->rt6i_flags |= RTF_ANYCAST;
1347 #ifdef CONFIG_IPV6_SUBTREES
1348 		if (rt->rt6i_src.plen && saddr) {
1349 			rt->rt6i_src.addr = *saddr;
1350 			rt->rt6i_src.plen = 128;
1351 		}
1352 #endif
1353 	}
1354 
1355 	return rt;
1356 }
1357 
ip6_rt_pcpu_alloc(const struct fib6_result * res)1358 static struct rt6_info *ip6_rt_pcpu_alloc(const struct fib6_result *res)
1359 {
1360 	struct fib6_info *f6i = res->f6i;
1361 	unsigned short flags = fib6_info_dst_flags(f6i);
1362 	struct net_device *dev;
1363 	struct rt6_info *pcpu_rt;
1364 
1365 	if (!fib6_info_hold_safe(f6i))
1366 		return NULL;
1367 
1368 	rcu_read_lock();
1369 	dev = ip6_rt_get_dev_rcu(res);
1370 	pcpu_rt = ip6_dst_alloc(dev_net(dev), dev, flags | DST_NOCOUNT);
1371 	rcu_read_unlock();
1372 	if (!pcpu_rt) {
1373 		fib6_info_release(f6i);
1374 		return NULL;
1375 	}
1376 	ip6_rt_copy_init(pcpu_rt, res);
1377 	pcpu_rt->rt6i_flags |= RTF_PCPU;
1378 
1379 	if (f6i->nh)
1380 		pcpu_rt->sernum = rt_genid_ipv6(dev_net(dev));
1381 
1382 	return pcpu_rt;
1383 }
1384 
rt6_is_valid(const struct rt6_info * rt6)1385 static bool rt6_is_valid(const struct rt6_info *rt6)
1386 {
1387 	return rt6->sernum == rt_genid_ipv6(dev_net(rt6->dst.dev));
1388 }
1389 
1390 /* It should be called with rcu_read_lock() acquired */
rt6_get_pcpu_route(const struct fib6_result * res)1391 static struct rt6_info *rt6_get_pcpu_route(const struct fib6_result *res)
1392 {
1393 	struct rt6_info *pcpu_rt;
1394 
1395 	pcpu_rt = this_cpu_read(*res->nh->rt6i_pcpu);
1396 
1397 	if (pcpu_rt && pcpu_rt->sernum && !rt6_is_valid(pcpu_rt)) {
1398 		struct rt6_info *prev, **p;
1399 
1400 		p = this_cpu_ptr(res->nh->rt6i_pcpu);
1401 		prev = xchg(p, NULL);
1402 		if (prev) {
1403 			dst_dev_put(&prev->dst);
1404 			dst_release(&prev->dst);
1405 		}
1406 
1407 		pcpu_rt = NULL;
1408 	}
1409 
1410 	return pcpu_rt;
1411 }
1412 
rt6_make_pcpu_route(struct net * net,const struct fib6_result * res)1413 static struct rt6_info *rt6_make_pcpu_route(struct net *net,
1414 					    const struct fib6_result *res)
1415 {
1416 	struct rt6_info *pcpu_rt, *prev, **p;
1417 
1418 	pcpu_rt = ip6_rt_pcpu_alloc(res);
1419 	if (!pcpu_rt)
1420 		return NULL;
1421 
1422 	p = this_cpu_ptr(res->nh->rt6i_pcpu);
1423 	prev = cmpxchg(p, NULL, pcpu_rt);
1424 	BUG_ON(prev);
1425 
1426 	if (res->f6i->fib6_destroying) {
1427 		struct fib6_info *from;
1428 
1429 		from = xchg((__force struct fib6_info **)&pcpu_rt->from, NULL);
1430 		fib6_info_release(from);
1431 	}
1432 
1433 	return pcpu_rt;
1434 }
1435 
1436 /* exception hash table implementation
1437  */
1438 static DEFINE_SPINLOCK(rt6_exception_lock);
1439 
1440 /* Remove rt6_ex from hash table and free the memory
1441  * Caller must hold rt6_exception_lock
1442  */
rt6_remove_exception(struct rt6_exception_bucket * bucket,struct rt6_exception * rt6_ex)1443 static void rt6_remove_exception(struct rt6_exception_bucket *bucket,
1444 				 struct rt6_exception *rt6_ex)
1445 {
1446 	struct fib6_info *from;
1447 	struct net *net;
1448 
1449 	if (!bucket || !rt6_ex)
1450 		return;
1451 
1452 	net = dev_net(rt6_ex->rt6i->dst.dev);
1453 	net->ipv6.rt6_stats->fib_rt_cache--;
1454 
1455 	/* purge completely the exception to allow releasing the held resources:
1456 	 * some [sk] cache may keep the dst around for unlimited time
1457 	 */
1458 	from = xchg((__force struct fib6_info **)&rt6_ex->rt6i->from, NULL);
1459 	fib6_info_release(from);
1460 	dst_dev_put(&rt6_ex->rt6i->dst);
1461 
1462 	hlist_del_rcu(&rt6_ex->hlist);
1463 	dst_release(&rt6_ex->rt6i->dst);
1464 	kfree_rcu(rt6_ex, rcu);
1465 	WARN_ON_ONCE(!bucket->depth);
1466 	bucket->depth--;
1467 }
1468 
1469 /* Remove oldest rt6_ex in bucket and free the memory
1470  * Caller must hold rt6_exception_lock
1471  */
rt6_exception_remove_oldest(struct rt6_exception_bucket * bucket)1472 static void rt6_exception_remove_oldest(struct rt6_exception_bucket *bucket)
1473 {
1474 	struct rt6_exception *rt6_ex, *oldest = NULL;
1475 
1476 	if (!bucket)
1477 		return;
1478 
1479 	hlist_for_each_entry(rt6_ex, &bucket->chain, hlist) {
1480 		if (!oldest || time_before(rt6_ex->stamp, oldest->stamp))
1481 			oldest = rt6_ex;
1482 	}
1483 	rt6_remove_exception(bucket, oldest);
1484 }
1485 
rt6_exception_hash(const struct in6_addr * dst,const struct in6_addr * src)1486 static u32 rt6_exception_hash(const struct in6_addr *dst,
1487 			      const struct in6_addr *src)
1488 {
1489 	static siphash_aligned_key_t rt6_exception_key;
1490 	struct {
1491 		struct in6_addr dst;
1492 		struct in6_addr src;
1493 	} __aligned(SIPHASH_ALIGNMENT) combined = {
1494 		.dst = *dst,
1495 	};
1496 	u64 val;
1497 
1498 	net_get_random_once(&rt6_exception_key, sizeof(rt6_exception_key));
1499 
1500 #ifdef CONFIG_IPV6_SUBTREES
1501 	if (src)
1502 		combined.src = *src;
1503 #endif
1504 	val = siphash(&combined, sizeof(combined), &rt6_exception_key);
1505 
1506 	return hash_64(val, FIB6_EXCEPTION_BUCKET_SIZE_SHIFT);
1507 }
1508 
1509 /* Helper function to find the cached rt in the hash table
1510  * and update bucket pointer to point to the bucket for this
1511  * (daddr, saddr) pair
1512  * Caller must hold rt6_exception_lock
1513  */
1514 static struct rt6_exception *
__rt6_find_exception_spinlock(struct rt6_exception_bucket ** bucket,const struct in6_addr * daddr,const struct in6_addr * saddr)1515 __rt6_find_exception_spinlock(struct rt6_exception_bucket **bucket,
1516 			      const struct in6_addr *daddr,
1517 			      const struct in6_addr *saddr)
1518 {
1519 	struct rt6_exception *rt6_ex;
1520 	u32 hval;
1521 
1522 	if (!(*bucket) || !daddr)
1523 		return NULL;
1524 
1525 	hval = rt6_exception_hash(daddr, saddr);
1526 	*bucket += hval;
1527 
1528 	hlist_for_each_entry(rt6_ex, &(*bucket)->chain, hlist) {
1529 		struct rt6_info *rt6 = rt6_ex->rt6i;
1530 		bool matched = ipv6_addr_equal(daddr, &rt6->rt6i_dst.addr);
1531 
1532 #ifdef CONFIG_IPV6_SUBTREES
1533 		if (matched && saddr)
1534 			matched = ipv6_addr_equal(saddr, &rt6->rt6i_src.addr);
1535 #endif
1536 		if (matched)
1537 			return rt6_ex;
1538 	}
1539 	return NULL;
1540 }
1541 
1542 /* Helper function to find the cached rt in the hash table
1543  * and update bucket pointer to point to the bucket for this
1544  * (daddr, saddr) pair
1545  * Caller must hold rcu_read_lock()
1546  */
1547 static struct rt6_exception *
__rt6_find_exception_rcu(struct rt6_exception_bucket ** bucket,const struct in6_addr * daddr,const struct in6_addr * saddr)1548 __rt6_find_exception_rcu(struct rt6_exception_bucket **bucket,
1549 			 const struct in6_addr *daddr,
1550 			 const struct in6_addr *saddr)
1551 {
1552 	struct rt6_exception *rt6_ex;
1553 	u32 hval;
1554 
1555 	WARN_ON_ONCE(!rcu_read_lock_held());
1556 
1557 	if (!(*bucket) || !daddr)
1558 		return NULL;
1559 
1560 	hval = rt6_exception_hash(daddr, saddr);
1561 	*bucket += hval;
1562 
1563 	hlist_for_each_entry_rcu(rt6_ex, &(*bucket)->chain, hlist) {
1564 		struct rt6_info *rt6 = rt6_ex->rt6i;
1565 		bool matched = ipv6_addr_equal(daddr, &rt6->rt6i_dst.addr);
1566 
1567 #ifdef CONFIG_IPV6_SUBTREES
1568 		if (matched && saddr)
1569 			matched = ipv6_addr_equal(saddr, &rt6->rt6i_src.addr);
1570 #endif
1571 		if (matched)
1572 			return rt6_ex;
1573 	}
1574 	return NULL;
1575 }
1576 
fib6_mtu(const struct fib6_result * res)1577 static unsigned int fib6_mtu(const struct fib6_result *res)
1578 {
1579 	const struct fib6_nh *nh = res->nh;
1580 	unsigned int mtu;
1581 
1582 	if (res->f6i->fib6_pmtu) {
1583 		mtu = res->f6i->fib6_pmtu;
1584 	} else {
1585 		struct net_device *dev = nh->fib_nh_dev;
1586 		struct inet6_dev *idev;
1587 
1588 		rcu_read_lock();
1589 		idev = __in6_dev_get(dev);
1590 		mtu = idev->cnf.mtu6;
1591 		rcu_read_unlock();
1592 	}
1593 
1594 	mtu = min_t(unsigned int, mtu, IP6_MAX_MTU);
1595 
1596 	return mtu - lwtunnel_headroom(nh->fib_nh_lws, mtu);
1597 }
1598 
1599 #define FIB6_EXCEPTION_BUCKET_FLUSHED  0x1UL
1600 
1601 /* used when the flushed bit is not relevant, only access to the bucket
1602  * (ie., all bucket users except rt6_insert_exception);
1603  *
1604  * called under rcu lock; sometimes called with rt6_exception_lock held
1605  */
1606 static
fib6_nh_get_excptn_bucket(const struct fib6_nh * nh,spinlock_t * lock)1607 struct rt6_exception_bucket *fib6_nh_get_excptn_bucket(const struct fib6_nh *nh,
1608 						       spinlock_t *lock)
1609 {
1610 	struct rt6_exception_bucket *bucket;
1611 
1612 	if (lock)
1613 		bucket = rcu_dereference_protected(nh->rt6i_exception_bucket,
1614 						   lockdep_is_held(lock));
1615 	else
1616 		bucket = rcu_dereference(nh->rt6i_exception_bucket);
1617 
1618 	/* remove bucket flushed bit if set */
1619 	if (bucket) {
1620 		unsigned long p = (unsigned long)bucket;
1621 
1622 		p &= ~FIB6_EXCEPTION_BUCKET_FLUSHED;
1623 		bucket = (struct rt6_exception_bucket *)p;
1624 	}
1625 
1626 	return bucket;
1627 }
1628 
fib6_nh_excptn_bucket_flushed(struct rt6_exception_bucket * bucket)1629 static bool fib6_nh_excptn_bucket_flushed(struct rt6_exception_bucket *bucket)
1630 {
1631 	unsigned long p = (unsigned long)bucket;
1632 
1633 	return !!(p & FIB6_EXCEPTION_BUCKET_FLUSHED);
1634 }
1635 
1636 /* called with rt6_exception_lock held */
fib6_nh_excptn_bucket_set_flushed(struct fib6_nh * nh,spinlock_t * lock)1637 static void fib6_nh_excptn_bucket_set_flushed(struct fib6_nh *nh,
1638 					      spinlock_t *lock)
1639 {
1640 	struct rt6_exception_bucket *bucket;
1641 	unsigned long p;
1642 
1643 	bucket = rcu_dereference_protected(nh->rt6i_exception_bucket,
1644 					   lockdep_is_held(lock));
1645 
1646 	p = (unsigned long)bucket;
1647 	p |= FIB6_EXCEPTION_BUCKET_FLUSHED;
1648 	bucket = (struct rt6_exception_bucket *)p;
1649 	rcu_assign_pointer(nh->rt6i_exception_bucket, bucket);
1650 }
1651 
rt6_insert_exception(struct rt6_info * nrt,const struct fib6_result * res)1652 static int rt6_insert_exception(struct rt6_info *nrt,
1653 				const struct fib6_result *res)
1654 {
1655 	struct net *net = dev_net(nrt->dst.dev);
1656 	struct rt6_exception_bucket *bucket;
1657 	struct fib6_info *f6i = res->f6i;
1658 	struct in6_addr *src_key = NULL;
1659 	struct rt6_exception *rt6_ex;
1660 	struct fib6_nh *nh = res->nh;
1661 	int max_depth;
1662 	int err = 0;
1663 
1664 	spin_lock_bh(&rt6_exception_lock);
1665 
1666 	bucket = rcu_dereference_protected(nh->rt6i_exception_bucket,
1667 					  lockdep_is_held(&rt6_exception_lock));
1668 	if (!bucket) {
1669 		bucket = kcalloc(FIB6_EXCEPTION_BUCKET_SIZE, sizeof(*bucket),
1670 				 GFP_ATOMIC);
1671 		if (!bucket) {
1672 			err = -ENOMEM;
1673 			goto out;
1674 		}
1675 		rcu_assign_pointer(nh->rt6i_exception_bucket, bucket);
1676 	} else if (fib6_nh_excptn_bucket_flushed(bucket)) {
1677 		err = -EINVAL;
1678 		goto out;
1679 	}
1680 
1681 #ifdef CONFIG_IPV6_SUBTREES
1682 	/* fib6_src.plen != 0 indicates f6i is in subtree
1683 	 * and exception table is indexed by a hash of
1684 	 * both fib6_dst and fib6_src.
1685 	 * Otherwise, the exception table is indexed by
1686 	 * a hash of only fib6_dst.
1687 	 */
1688 	if (f6i->fib6_src.plen)
1689 		src_key = &nrt->rt6i_src.addr;
1690 #endif
1691 	/* rt6_mtu_change() might lower mtu on f6i.
1692 	 * Only insert this exception route if its mtu
1693 	 * is less than f6i's mtu value.
1694 	 */
1695 	if (dst_metric_raw(&nrt->dst, RTAX_MTU) >= fib6_mtu(res)) {
1696 		err = -EINVAL;
1697 		goto out;
1698 	}
1699 
1700 	rt6_ex = __rt6_find_exception_spinlock(&bucket, &nrt->rt6i_dst.addr,
1701 					       src_key);
1702 	if (rt6_ex)
1703 		rt6_remove_exception(bucket, rt6_ex);
1704 
1705 	rt6_ex = kzalloc(sizeof(*rt6_ex), GFP_ATOMIC);
1706 	if (!rt6_ex) {
1707 		err = -ENOMEM;
1708 		goto out;
1709 	}
1710 	rt6_ex->rt6i = nrt;
1711 	rt6_ex->stamp = jiffies;
1712 	hlist_add_head_rcu(&rt6_ex->hlist, &bucket->chain);
1713 	bucket->depth++;
1714 	net->ipv6.rt6_stats->fib_rt_cache++;
1715 
1716 	/* Randomize max depth to avoid some side channels attacks. */
1717 	max_depth = FIB6_MAX_DEPTH + get_random_u32_below(FIB6_MAX_DEPTH);
1718 	while (bucket->depth > max_depth)
1719 		rt6_exception_remove_oldest(bucket);
1720 
1721 out:
1722 	spin_unlock_bh(&rt6_exception_lock);
1723 
1724 	/* Update fn->fn_sernum to invalidate all cached dst */
1725 	if (!err) {
1726 		spin_lock_bh(&f6i->fib6_table->tb6_lock);
1727 		fib6_update_sernum(net, f6i);
1728 		spin_unlock_bh(&f6i->fib6_table->tb6_lock);
1729 		fib6_force_start_gc(net);
1730 	}
1731 
1732 	return err;
1733 }
1734 
fib6_nh_flush_exceptions(struct fib6_nh * nh,struct fib6_info * from)1735 static void fib6_nh_flush_exceptions(struct fib6_nh *nh, struct fib6_info *from)
1736 {
1737 	struct rt6_exception_bucket *bucket;
1738 	struct rt6_exception *rt6_ex;
1739 	struct hlist_node *tmp;
1740 	int i;
1741 
1742 	spin_lock_bh(&rt6_exception_lock);
1743 
1744 	bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock);
1745 	if (!bucket)
1746 		goto out;
1747 
1748 	/* Prevent rt6_insert_exception() to recreate the bucket list */
1749 	if (!from)
1750 		fib6_nh_excptn_bucket_set_flushed(nh, &rt6_exception_lock);
1751 
1752 	for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
1753 		hlist_for_each_entry_safe(rt6_ex, tmp, &bucket->chain, hlist) {
1754 			if (!from ||
1755 			    rcu_access_pointer(rt6_ex->rt6i->from) == from)
1756 				rt6_remove_exception(bucket, rt6_ex);
1757 		}
1758 		WARN_ON_ONCE(!from && bucket->depth);
1759 		bucket++;
1760 	}
1761 out:
1762 	spin_unlock_bh(&rt6_exception_lock);
1763 }
1764 
rt6_nh_flush_exceptions(struct fib6_nh * nh,void * arg)1765 static int rt6_nh_flush_exceptions(struct fib6_nh *nh, void *arg)
1766 {
1767 	struct fib6_info *f6i = arg;
1768 
1769 	fib6_nh_flush_exceptions(nh, f6i);
1770 
1771 	return 0;
1772 }
1773 
rt6_flush_exceptions(struct fib6_info * f6i)1774 void rt6_flush_exceptions(struct fib6_info *f6i)
1775 {
1776 	if (f6i->nh)
1777 		nexthop_for_each_fib6_nh(f6i->nh, rt6_nh_flush_exceptions,
1778 					 f6i);
1779 	else
1780 		fib6_nh_flush_exceptions(f6i->fib6_nh, f6i);
1781 }
1782 
1783 /* Find cached rt in the hash table inside passed in rt
1784  * Caller has to hold rcu_read_lock()
1785  */
rt6_find_cached_rt(const struct fib6_result * res,const struct in6_addr * daddr,const struct in6_addr * saddr)1786 static struct rt6_info *rt6_find_cached_rt(const struct fib6_result *res,
1787 					   const struct in6_addr *daddr,
1788 					   const struct in6_addr *saddr)
1789 {
1790 	const struct in6_addr *src_key = NULL;
1791 	struct rt6_exception_bucket *bucket;
1792 	struct rt6_exception *rt6_ex;
1793 	struct rt6_info *ret = NULL;
1794 
1795 #ifdef CONFIG_IPV6_SUBTREES
1796 	/* fib6i_src.plen != 0 indicates f6i is in subtree
1797 	 * and exception table is indexed by a hash of
1798 	 * both fib6_dst and fib6_src.
1799 	 * However, the src addr used to create the hash
1800 	 * might not be exactly the passed in saddr which
1801 	 * is a /128 addr from the flow.
1802 	 * So we need to use f6i->fib6_src to redo lookup
1803 	 * if the passed in saddr does not find anything.
1804 	 * (See the logic in ip6_rt_cache_alloc() on how
1805 	 * rt->rt6i_src is updated.)
1806 	 */
1807 	if (res->f6i->fib6_src.plen)
1808 		src_key = saddr;
1809 find_ex:
1810 #endif
1811 	bucket = fib6_nh_get_excptn_bucket(res->nh, NULL);
1812 	rt6_ex = __rt6_find_exception_rcu(&bucket, daddr, src_key);
1813 
1814 	if (rt6_ex && !rt6_check_expired(rt6_ex->rt6i))
1815 		ret = rt6_ex->rt6i;
1816 
1817 #ifdef CONFIG_IPV6_SUBTREES
1818 	/* Use fib6_src as src_key and redo lookup */
1819 	if (!ret && src_key && src_key != &res->f6i->fib6_src.addr) {
1820 		src_key = &res->f6i->fib6_src.addr;
1821 		goto find_ex;
1822 	}
1823 #endif
1824 
1825 	return ret;
1826 }
1827 
1828 /* Remove the passed in cached rt from the hash table that contains it */
fib6_nh_remove_exception(const struct fib6_nh * nh,int plen,const struct rt6_info * rt)1829 static int fib6_nh_remove_exception(const struct fib6_nh *nh, int plen,
1830 				    const struct rt6_info *rt)
1831 {
1832 	const struct in6_addr *src_key = NULL;
1833 	struct rt6_exception_bucket *bucket;
1834 	struct rt6_exception *rt6_ex;
1835 	int err;
1836 
1837 	if (!rcu_access_pointer(nh->rt6i_exception_bucket))
1838 		return -ENOENT;
1839 
1840 	spin_lock_bh(&rt6_exception_lock);
1841 	bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock);
1842 
1843 #ifdef CONFIG_IPV6_SUBTREES
1844 	/* rt6i_src.plen != 0 indicates 'from' is in subtree
1845 	 * and exception table is indexed by a hash of
1846 	 * both rt6i_dst and rt6i_src.
1847 	 * Otherwise, the exception table is indexed by
1848 	 * a hash of only rt6i_dst.
1849 	 */
1850 	if (plen)
1851 		src_key = &rt->rt6i_src.addr;
1852 #endif
1853 	rt6_ex = __rt6_find_exception_spinlock(&bucket,
1854 					       &rt->rt6i_dst.addr,
1855 					       src_key);
1856 	if (rt6_ex) {
1857 		rt6_remove_exception(bucket, rt6_ex);
1858 		err = 0;
1859 	} else {
1860 		err = -ENOENT;
1861 	}
1862 
1863 	spin_unlock_bh(&rt6_exception_lock);
1864 	return err;
1865 }
1866 
1867 struct fib6_nh_excptn_arg {
1868 	struct rt6_info	*rt;
1869 	int		plen;
1870 };
1871 
rt6_nh_remove_exception_rt(struct fib6_nh * nh,void * _arg)1872 static int rt6_nh_remove_exception_rt(struct fib6_nh *nh, void *_arg)
1873 {
1874 	struct fib6_nh_excptn_arg *arg = _arg;
1875 	int err;
1876 
1877 	err = fib6_nh_remove_exception(nh, arg->plen, arg->rt);
1878 	if (err == 0)
1879 		return 1;
1880 
1881 	return 0;
1882 }
1883 
rt6_remove_exception_rt(struct rt6_info * rt)1884 static int rt6_remove_exception_rt(struct rt6_info *rt)
1885 {
1886 	struct fib6_info *from;
1887 
1888 	from = rcu_dereference(rt->from);
1889 	if (!from || !(rt->rt6i_flags & RTF_CACHE))
1890 		return -EINVAL;
1891 
1892 	if (from->nh) {
1893 		struct fib6_nh_excptn_arg arg = {
1894 			.rt = rt,
1895 			.plen = from->fib6_src.plen
1896 		};
1897 		int rc;
1898 
1899 		/* rc = 1 means an entry was found */
1900 		rc = nexthop_for_each_fib6_nh(from->nh,
1901 					      rt6_nh_remove_exception_rt,
1902 					      &arg);
1903 		return rc ? 0 : -ENOENT;
1904 	}
1905 
1906 	return fib6_nh_remove_exception(from->fib6_nh,
1907 					from->fib6_src.plen, rt);
1908 }
1909 
1910 /* Find rt6_ex which contains the passed in rt cache and
1911  * refresh its stamp
1912  */
fib6_nh_update_exception(const struct fib6_nh * nh,int plen,const struct rt6_info * rt)1913 static void fib6_nh_update_exception(const struct fib6_nh *nh, int plen,
1914 				     const struct rt6_info *rt)
1915 {
1916 	const struct in6_addr *src_key = NULL;
1917 	struct rt6_exception_bucket *bucket;
1918 	struct rt6_exception *rt6_ex;
1919 
1920 	bucket = fib6_nh_get_excptn_bucket(nh, NULL);
1921 #ifdef CONFIG_IPV6_SUBTREES
1922 	/* rt6i_src.plen != 0 indicates 'from' is in subtree
1923 	 * and exception table is indexed by a hash of
1924 	 * both rt6i_dst and rt6i_src.
1925 	 * Otherwise, the exception table is indexed by
1926 	 * a hash of only rt6i_dst.
1927 	 */
1928 	if (plen)
1929 		src_key = &rt->rt6i_src.addr;
1930 #endif
1931 	rt6_ex = __rt6_find_exception_rcu(&bucket, &rt->rt6i_dst.addr, src_key);
1932 	if (rt6_ex)
1933 		rt6_ex->stamp = jiffies;
1934 }
1935 
1936 struct fib6_nh_match_arg {
1937 	const struct net_device *dev;
1938 	const struct in6_addr	*gw;
1939 	struct fib6_nh		*match;
1940 };
1941 
1942 /* determine if fib6_nh has given device and gateway */
fib6_nh_find_match(struct fib6_nh * nh,void * _arg)1943 static int fib6_nh_find_match(struct fib6_nh *nh, void *_arg)
1944 {
1945 	struct fib6_nh_match_arg *arg = _arg;
1946 
1947 	if (arg->dev != nh->fib_nh_dev ||
1948 	    (arg->gw && !nh->fib_nh_gw_family) ||
1949 	    (!arg->gw && nh->fib_nh_gw_family) ||
1950 	    (arg->gw && !ipv6_addr_equal(arg->gw, &nh->fib_nh_gw6)))
1951 		return 0;
1952 
1953 	arg->match = nh;
1954 
1955 	/* found a match, break the loop */
1956 	return 1;
1957 }
1958 
rt6_update_exception_stamp_rt(struct rt6_info * rt)1959 static void rt6_update_exception_stamp_rt(struct rt6_info *rt)
1960 {
1961 	struct fib6_info *from;
1962 	struct fib6_nh *fib6_nh;
1963 
1964 	rcu_read_lock();
1965 
1966 	from = rcu_dereference(rt->from);
1967 	if (!from || !(rt->rt6i_flags & RTF_CACHE))
1968 		goto unlock;
1969 
1970 	if (from->nh) {
1971 		struct fib6_nh_match_arg arg = {
1972 			.dev = rt->dst.dev,
1973 			.gw = &rt->rt6i_gateway,
1974 		};
1975 
1976 		nexthop_for_each_fib6_nh(from->nh, fib6_nh_find_match, &arg);
1977 
1978 		if (!arg.match)
1979 			goto unlock;
1980 		fib6_nh = arg.match;
1981 	} else {
1982 		fib6_nh = from->fib6_nh;
1983 	}
1984 	fib6_nh_update_exception(fib6_nh, from->fib6_src.plen, rt);
1985 unlock:
1986 	rcu_read_unlock();
1987 }
1988 
rt6_mtu_change_route_allowed(struct inet6_dev * idev,struct rt6_info * rt,int mtu)1989 static bool rt6_mtu_change_route_allowed(struct inet6_dev *idev,
1990 					 struct rt6_info *rt, int mtu)
1991 {
1992 	/* If the new MTU is lower than the route PMTU, this new MTU will be the
1993 	 * lowest MTU in the path: always allow updating the route PMTU to
1994 	 * reflect PMTU decreases.
1995 	 *
1996 	 * If the new MTU is higher, and the route PMTU is equal to the local
1997 	 * MTU, this means the old MTU is the lowest in the path, so allow
1998 	 * updating it: if other nodes now have lower MTUs, PMTU discovery will
1999 	 * handle this.
2000 	 */
2001 
2002 	if (dst_mtu(&rt->dst) >= mtu)
2003 		return true;
2004 
2005 	if (dst_mtu(&rt->dst) == idev->cnf.mtu6)
2006 		return true;
2007 
2008 	return false;
2009 }
2010 
rt6_exceptions_update_pmtu(struct inet6_dev * idev,const struct fib6_nh * nh,int mtu)2011 static void rt6_exceptions_update_pmtu(struct inet6_dev *idev,
2012 				       const struct fib6_nh *nh, int mtu)
2013 {
2014 	struct rt6_exception_bucket *bucket;
2015 	struct rt6_exception *rt6_ex;
2016 	int i;
2017 
2018 	bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock);
2019 	if (!bucket)
2020 		return;
2021 
2022 	for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
2023 		hlist_for_each_entry(rt6_ex, &bucket->chain, hlist) {
2024 			struct rt6_info *entry = rt6_ex->rt6i;
2025 
2026 			/* For RTF_CACHE with rt6i_pmtu == 0 (i.e. a redirected
2027 			 * route), the metrics of its rt->from have already
2028 			 * been updated.
2029 			 */
2030 			if (dst_metric_raw(&entry->dst, RTAX_MTU) &&
2031 			    rt6_mtu_change_route_allowed(idev, entry, mtu))
2032 				dst_metric_set(&entry->dst, RTAX_MTU, mtu);
2033 		}
2034 		bucket++;
2035 	}
2036 }
2037 
2038 #define RTF_CACHE_GATEWAY	(RTF_GATEWAY | RTF_CACHE)
2039 
fib6_nh_exceptions_clean_tohost(const struct fib6_nh * nh,const struct in6_addr * gateway)2040 static void fib6_nh_exceptions_clean_tohost(const struct fib6_nh *nh,
2041 					    const struct in6_addr *gateway)
2042 {
2043 	struct rt6_exception_bucket *bucket;
2044 	struct rt6_exception *rt6_ex;
2045 	struct hlist_node *tmp;
2046 	int i;
2047 
2048 	if (!rcu_access_pointer(nh->rt6i_exception_bucket))
2049 		return;
2050 
2051 	spin_lock_bh(&rt6_exception_lock);
2052 	bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock);
2053 	if (bucket) {
2054 		for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
2055 			hlist_for_each_entry_safe(rt6_ex, tmp,
2056 						  &bucket->chain, hlist) {
2057 				struct rt6_info *entry = rt6_ex->rt6i;
2058 
2059 				if ((entry->rt6i_flags & RTF_CACHE_GATEWAY) ==
2060 				    RTF_CACHE_GATEWAY &&
2061 				    ipv6_addr_equal(gateway,
2062 						    &entry->rt6i_gateway)) {
2063 					rt6_remove_exception(bucket, rt6_ex);
2064 				}
2065 			}
2066 			bucket++;
2067 		}
2068 	}
2069 
2070 	spin_unlock_bh(&rt6_exception_lock);
2071 }
2072 
rt6_age_examine_exception(struct rt6_exception_bucket * bucket,struct rt6_exception * rt6_ex,struct fib6_gc_args * gc_args,unsigned long now)2073 static void rt6_age_examine_exception(struct rt6_exception_bucket *bucket,
2074 				      struct rt6_exception *rt6_ex,
2075 				      struct fib6_gc_args *gc_args,
2076 				      unsigned long now)
2077 {
2078 	struct rt6_info *rt = rt6_ex->rt6i;
2079 
2080 	/* we are pruning and obsoleting aged-out and non gateway exceptions
2081 	 * even if others have still references to them, so that on next
2082 	 * dst_check() such references can be dropped.
2083 	 * EXPIRES exceptions - e.g. pmtu-generated ones are pruned when
2084 	 * expired, independently from their aging, as per RFC 8201 section 4
2085 	 */
2086 	if (!(rt->rt6i_flags & RTF_EXPIRES)) {
2087 		if (time_after_eq(now, rt->dst.lastuse + gc_args->timeout)) {
2088 			RT6_TRACE("aging clone %p\n", rt);
2089 			rt6_remove_exception(bucket, rt6_ex);
2090 			return;
2091 		}
2092 	} else if (time_after(jiffies, rt->dst.expires)) {
2093 		RT6_TRACE("purging expired route %p\n", rt);
2094 		rt6_remove_exception(bucket, rt6_ex);
2095 		return;
2096 	}
2097 
2098 	if (rt->rt6i_flags & RTF_GATEWAY) {
2099 		struct neighbour *neigh;
2100 
2101 		neigh = __ipv6_neigh_lookup_noref(rt->dst.dev, &rt->rt6i_gateway);
2102 
2103 		if (!(neigh && (neigh->flags & NTF_ROUTER))) {
2104 			RT6_TRACE("purging route %p via non-router but gateway\n",
2105 				  rt);
2106 			rt6_remove_exception(bucket, rt6_ex);
2107 			return;
2108 		}
2109 	}
2110 
2111 	gc_args->more++;
2112 }
2113 
fib6_nh_age_exceptions(const struct fib6_nh * nh,struct fib6_gc_args * gc_args,unsigned long now)2114 static void fib6_nh_age_exceptions(const struct fib6_nh *nh,
2115 				   struct fib6_gc_args *gc_args,
2116 				   unsigned long now)
2117 {
2118 	struct rt6_exception_bucket *bucket;
2119 	struct rt6_exception *rt6_ex;
2120 	struct hlist_node *tmp;
2121 	int i;
2122 
2123 	if (!rcu_access_pointer(nh->rt6i_exception_bucket))
2124 		return;
2125 
2126 	rcu_read_lock_bh();
2127 	spin_lock(&rt6_exception_lock);
2128 	bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock);
2129 	if (bucket) {
2130 		for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
2131 			hlist_for_each_entry_safe(rt6_ex, tmp,
2132 						  &bucket->chain, hlist) {
2133 				rt6_age_examine_exception(bucket, rt6_ex,
2134 							  gc_args, now);
2135 			}
2136 			bucket++;
2137 		}
2138 	}
2139 	spin_unlock(&rt6_exception_lock);
2140 	rcu_read_unlock_bh();
2141 }
2142 
2143 struct fib6_nh_age_excptn_arg {
2144 	struct fib6_gc_args	*gc_args;
2145 	unsigned long		now;
2146 };
2147 
rt6_nh_age_exceptions(struct fib6_nh * nh,void * _arg)2148 static int rt6_nh_age_exceptions(struct fib6_nh *nh, void *_arg)
2149 {
2150 	struct fib6_nh_age_excptn_arg *arg = _arg;
2151 
2152 	fib6_nh_age_exceptions(nh, arg->gc_args, arg->now);
2153 	return 0;
2154 }
2155 
rt6_age_exceptions(struct fib6_info * f6i,struct fib6_gc_args * gc_args,unsigned long now)2156 void rt6_age_exceptions(struct fib6_info *f6i,
2157 			struct fib6_gc_args *gc_args,
2158 			unsigned long now)
2159 {
2160 	if (f6i->nh) {
2161 		struct fib6_nh_age_excptn_arg arg = {
2162 			.gc_args = gc_args,
2163 			.now = now
2164 		};
2165 
2166 		nexthop_for_each_fib6_nh(f6i->nh, rt6_nh_age_exceptions,
2167 					 &arg);
2168 	} else {
2169 		fib6_nh_age_exceptions(f6i->fib6_nh, gc_args, now);
2170 	}
2171 }
2172 
2173 /* must be called with rcu lock held */
fib6_table_lookup(struct net * net,struct fib6_table * table,int oif,struct flowi6 * fl6,struct fib6_result * res,int strict)2174 int fib6_table_lookup(struct net *net, struct fib6_table *table, int oif,
2175 		      struct flowi6 *fl6, struct fib6_result *res, int strict)
2176 {
2177 	struct fib6_node *fn, *saved_fn;
2178 
2179 	fn = fib6_node_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr);
2180 	saved_fn = fn;
2181 
2182 redo_rt6_select:
2183 	rt6_select(net, fn, oif, res, strict);
2184 	if (res->f6i == net->ipv6.fib6_null_entry) {
2185 		fn = fib6_backtrack(fn, &fl6->saddr);
2186 		if (fn)
2187 			goto redo_rt6_select;
2188 		else if (strict & RT6_LOOKUP_F_REACHABLE) {
2189 			/* also consider unreachable route */
2190 			strict &= ~RT6_LOOKUP_F_REACHABLE;
2191 			fn = saved_fn;
2192 			goto redo_rt6_select;
2193 		}
2194 	}
2195 
2196 	trace_fib6_table_lookup(net, res, table, fl6);
2197 
2198 	return 0;
2199 }
2200 
ip6_pol_route(struct net * net,struct fib6_table * table,int oif,struct flowi6 * fl6,const struct sk_buff * skb,int flags)2201 struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table,
2202 			       int oif, struct flowi6 *fl6,
2203 			       const struct sk_buff *skb, int flags)
2204 {
2205 	struct fib6_result res = {};
2206 	struct rt6_info *rt = NULL;
2207 	int strict = 0;
2208 
2209 	WARN_ON_ONCE((flags & RT6_LOOKUP_F_DST_NOREF) &&
2210 		     !rcu_read_lock_held());
2211 
2212 	strict |= flags & RT6_LOOKUP_F_IFACE;
2213 	strict |= flags & RT6_LOOKUP_F_IGNORE_LINKSTATE;
2214 	if (net->ipv6.devconf_all->forwarding == 0)
2215 		strict |= RT6_LOOKUP_F_REACHABLE;
2216 
2217 	rcu_read_lock();
2218 
2219 	fib6_table_lookup(net, table, oif, fl6, &res, strict);
2220 	if (res.f6i == net->ipv6.fib6_null_entry)
2221 		goto out;
2222 
2223 	fib6_select_path(net, &res, fl6, oif, false, skb, strict);
2224 
2225 	/*Search through exception table */
2226 	rt = rt6_find_cached_rt(&res, &fl6->daddr, &fl6->saddr);
2227 	if (rt) {
2228 		goto out;
2229 	} else if (unlikely((fl6->flowi6_flags & FLOWI_FLAG_KNOWN_NH) &&
2230 			    !res.nh->fib_nh_gw_family)) {
2231 		/* Create a RTF_CACHE clone which will not be
2232 		 * owned by the fib6 tree.  It is for the special case where
2233 		 * the daddr in the skb during the neighbor look-up is different
2234 		 * from the fl6->daddr used to look-up route here.
2235 		 */
2236 		rt = ip6_rt_cache_alloc(&res, &fl6->daddr, NULL);
2237 
2238 		if (rt) {
2239 			/* 1 refcnt is taken during ip6_rt_cache_alloc().
2240 			 * As rt6_uncached_list_add() does not consume refcnt,
2241 			 * this refcnt is always returned to the caller even
2242 			 * if caller sets RT6_LOOKUP_F_DST_NOREF flag.
2243 			 */
2244 			rt6_uncached_list_add(rt);
2245 			rcu_read_unlock();
2246 
2247 			return rt;
2248 		}
2249 	} else {
2250 		/* Get a percpu copy */
2251 		local_bh_disable();
2252 		rt = rt6_get_pcpu_route(&res);
2253 
2254 		if (!rt)
2255 			rt = rt6_make_pcpu_route(net, &res);
2256 
2257 		local_bh_enable();
2258 	}
2259 out:
2260 	if (!rt)
2261 		rt = net->ipv6.ip6_null_entry;
2262 	if (!(flags & RT6_LOOKUP_F_DST_NOREF))
2263 		ip6_hold_safe(net, &rt);
2264 	rcu_read_unlock();
2265 
2266 	return rt;
2267 }
2268 EXPORT_SYMBOL_GPL(ip6_pol_route);
2269 
ip6_pol_route_input(struct net * net,struct fib6_table * table,struct flowi6 * fl6,const struct sk_buff * skb,int flags)2270 INDIRECT_CALLABLE_SCOPE struct rt6_info *ip6_pol_route_input(struct net *net,
2271 					    struct fib6_table *table,
2272 					    struct flowi6 *fl6,
2273 					    const struct sk_buff *skb,
2274 					    int flags)
2275 {
2276 	return ip6_pol_route(net, table, fl6->flowi6_iif, fl6, skb, flags);
2277 }
2278 
ip6_route_input_lookup(struct net * net,struct net_device * dev,struct flowi6 * fl6,const struct sk_buff * skb,int flags)2279 struct dst_entry *ip6_route_input_lookup(struct net *net,
2280 					 struct net_device *dev,
2281 					 struct flowi6 *fl6,
2282 					 const struct sk_buff *skb,
2283 					 int flags)
2284 {
2285 	if (rt6_need_strict(&fl6->daddr) && dev->type != ARPHRD_PIMREG)
2286 		flags |= RT6_LOOKUP_F_IFACE;
2287 
2288 	return fib6_rule_lookup(net, fl6, skb, flags, ip6_pol_route_input);
2289 }
2290 EXPORT_SYMBOL_GPL(ip6_route_input_lookup);
2291 
ip6_multipath_l3_keys(const struct sk_buff * skb,struct flow_keys * keys,struct flow_keys * flkeys)2292 static void ip6_multipath_l3_keys(const struct sk_buff *skb,
2293 				  struct flow_keys *keys,
2294 				  struct flow_keys *flkeys)
2295 {
2296 	const struct ipv6hdr *outer_iph = ipv6_hdr(skb);
2297 	const struct ipv6hdr *key_iph = outer_iph;
2298 	struct flow_keys *_flkeys = flkeys;
2299 	const struct ipv6hdr *inner_iph;
2300 	const struct icmp6hdr *icmph;
2301 	struct ipv6hdr _inner_iph;
2302 	struct icmp6hdr _icmph;
2303 
2304 	if (likely(outer_iph->nexthdr != IPPROTO_ICMPV6))
2305 		goto out;
2306 
2307 	icmph = skb_header_pointer(skb, skb_transport_offset(skb),
2308 				   sizeof(_icmph), &_icmph);
2309 	if (!icmph)
2310 		goto out;
2311 
2312 	if (!icmpv6_is_err(icmph->icmp6_type))
2313 		goto out;
2314 
2315 	inner_iph = skb_header_pointer(skb,
2316 				       skb_transport_offset(skb) + sizeof(*icmph),
2317 				       sizeof(_inner_iph), &_inner_iph);
2318 	if (!inner_iph)
2319 		goto out;
2320 
2321 	key_iph = inner_iph;
2322 	_flkeys = NULL;
2323 out:
2324 	if (_flkeys) {
2325 		keys->addrs.v6addrs.src = _flkeys->addrs.v6addrs.src;
2326 		keys->addrs.v6addrs.dst = _flkeys->addrs.v6addrs.dst;
2327 		keys->tags.flow_label = _flkeys->tags.flow_label;
2328 		keys->basic.ip_proto = _flkeys->basic.ip_proto;
2329 	} else {
2330 		keys->addrs.v6addrs.src = key_iph->saddr;
2331 		keys->addrs.v6addrs.dst = key_iph->daddr;
2332 		keys->tags.flow_label = ip6_flowlabel(key_iph);
2333 		keys->basic.ip_proto = key_iph->nexthdr;
2334 	}
2335 }
2336 
rt6_multipath_custom_hash_outer(const struct net * net,const struct sk_buff * skb,bool * p_has_inner)2337 static u32 rt6_multipath_custom_hash_outer(const struct net *net,
2338 					   const struct sk_buff *skb,
2339 					   bool *p_has_inner)
2340 {
2341 	u32 hash_fields = ip6_multipath_hash_fields(net);
2342 	struct flow_keys keys, hash_keys;
2343 
2344 	if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK))
2345 		return 0;
2346 
2347 	memset(&hash_keys, 0, sizeof(hash_keys));
2348 	skb_flow_dissect_flow_keys(skb, &keys, FLOW_DISSECTOR_F_STOP_AT_ENCAP);
2349 
2350 	hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2351 	if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP)
2352 		hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src;
2353 	if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP)
2354 		hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst;
2355 	if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO)
2356 		hash_keys.basic.ip_proto = keys.basic.ip_proto;
2357 	if (hash_fields & FIB_MULTIPATH_HASH_FIELD_FLOWLABEL)
2358 		hash_keys.tags.flow_label = keys.tags.flow_label;
2359 	if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT)
2360 		hash_keys.ports.src = keys.ports.src;
2361 	if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT)
2362 		hash_keys.ports.dst = keys.ports.dst;
2363 
2364 	*p_has_inner = !!(keys.control.flags & FLOW_DIS_ENCAPSULATION);
2365 	return flow_hash_from_keys(&hash_keys);
2366 }
2367 
rt6_multipath_custom_hash_inner(const struct net * net,const struct sk_buff * skb,bool has_inner)2368 static u32 rt6_multipath_custom_hash_inner(const struct net *net,
2369 					   const struct sk_buff *skb,
2370 					   bool has_inner)
2371 {
2372 	u32 hash_fields = ip6_multipath_hash_fields(net);
2373 	struct flow_keys keys, hash_keys;
2374 
2375 	/* We assume the packet carries an encapsulation, but if none was
2376 	 * encountered during dissection of the outer flow, then there is no
2377 	 * point in calling the flow dissector again.
2378 	 */
2379 	if (!has_inner)
2380 		return 0;
2381 
2382 	if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_MASK))
2383 		return 0;
2384 
2385 	memset(&hash_keys, 0, sizeof(hash_keys));
2386 	skb_flow_dissect_flow_keys(skb, &keys, 0);
2387 
2388 	if (!(keys.control.flags & FLOW_DIS_ENCAPSULATION))
2389 		return 0;
2390 
2391 	if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) {
2392 		hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
2393 		if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP)
2394 			hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src;
2395 		if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP)
2396 			hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst;
2397 	} else if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) {
2398 		hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2399 		if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP)
2400 			hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src;
2401 		if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP)
2402 			hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst;
2403 		if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_FLOWLABEL)
2404 			hash_keys.tags.flow_label = keys.tags.flow_label;
2405 	}
2406 
2407 	if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_IP_PROTO)
2408 		hash_keys.basic.ip_proto = keys.basic.ip_proto;
2409 	if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_PORT)
2410 		hash_keys.ports.src = keys.ports.src;
2411 	if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_PORT)
2412 		hash_keys.ports.dst = keys.ports.dst;
2413 
2414 	return flow_hash_from_keys(&hash_keys);
2415 }
2416 
rt6_multipath_custom_hash_skb(const struct net * net,const struct sk_buff * skb)2417 static u32 rt6_multipath_custom_hash_skb(const struct net *net,
2418 					 const struct sk_buff *skb)
2419 {
2420 	u32 mhash, mhash_inner;
2421 	bool has_inner = true;
2422 
2423 	mhash = rt6_multipath_custom_hash_outer(net, skb, &has_inner);
2424 	mhash_inner = rt6_multipath_custom_hash_inner(net, skb, has_inner);
2425 
2426 	return jhash_2words(mhash, mhash_inner, 0);
2427 }
2428 
rt6_multipath_custom_hash_fl6(const struct net * net,const struct flowi6 * fl6)2429 static u32 rt6_multipath_custom_hash_fl6(const struct net *net,
2430 					 const struct flowi6 *fl6)
2431 {
2432 	u32 hash_fields = ip6_multipath_hash_fields(net);
2433 	struct flow_keys hash_keys;
2434 
2435 	if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK))
2436 		return 0;
2437 
2438 	memset(&hash_keys, 0, sizeof(hash_keys));
2439 	hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2440 	if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP)
2441 		hash_keys.addrs.v6addrs.src = fl6->saddr;
2442 	if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP)
2443 		hash_keys.addrs.v6addrs.dst = fl6->daddr;
2444 	if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO)
2445 		hash_keys.basic.ip_proto = fl6->flowi6_proto;
2446 	if (hash_fields & FIB_MULTIPATH_HASH_FIELD_FLOWLABEL)
2447 		hash_keys.tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6);
2448 	if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT)
2449 		hash_keys.ports.src = fl6->fl6_sport;
2450 	if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT)
2451 		hash_keys.ports.dst = fl6->fl6_dport;
2452 
2453 	return flow_hash_from_keys(&hash_keys);
2454 }
2455 
2456 /* if skb is set it will be used and fl6 can be NULL */
rt6_multipath_hash(const struct net * net,const struct flowi6 * fl6,const struct sk_buff * skb,struct flow_keys * flkeys)2457 u32 rt6_multipath_hash(const struct net *net, const struct flowi6 *fl6,
2458 		       const struct sk_buff *skb, struct flow_keys *flkeys)
2459 {
2460 	struct flow_keys hash_keys;
2461 	u32 mhash = 0;
2462 
2463 	switch (ip6_multipath_hash_policy(net)) {
2464 	case 0:
2465 		memset(&hash_keys, 0, sizeof(hash_keys));
2466 		hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2467 		if (skb) {
2468 			ip6_multipath_l3_keys(skb, &hash_keys, flkeys);
2469 		} else {
2470 			hash_keys.addrs.v6addrs.src = fl6->saddr;
2471 			hash_keys.addrs.v6addrs.dst = fl6->daddr;
2472 			hash_keys.tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6);
2473 			hash_keys.basic.ip_proto = fl6->flowi6_proto;
2474 		}
2475 		mhash = flow_hash_from_keys(&hash_keys);
2476 		break;
2477 	case 1:
2478 		if (skb) {
2479 			unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP;
2480 			struct flow_keys keys;
2481 
2482 			/* short-circuit if we already have L4 hash present */
2483 			if (skb->l4_hash)
2484 				return skb_get_hash_raw(skb) >> 1;
2485 
2486 			memset(&hash_keys, 0, sizeof(hash_keys));
2487 
2488 			if (!flkeys) {
2489 				skb_flow_dissect_flow_keys(skb, &keys, flag);
2490 				flkeys = &keys;
2491 			}
2492 			hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2493 			hash_keys.addrs.v6addrs.src = flkeys->addrs.v6addrs.src;
2494 			hash_keys.addrs.v6addrs.dst = flkeys->addrs.v6addrs.dst;
2495 			hash_keys.ports.src = flkeys->ports.src;
2496 			hash_keys.ports.dst = flkeys->ports.dst;
2497 			hash_keys.basic.ip_proto = flkeys->basic.ip_proto;
2498 		} else {
2499 			memset(&hash_keys, 0, sizeof(hash_keys));
2500 			hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2501 			hash_keys.addrs.v6addrs.src = fl6->saddr;
2502 			hash_keys.addrs.v6addrs.dst = fl6->daddr;
2503 			hash_keys.ports.src = fl6->fl6_sport;
2504 			hash_keys.ports.dst = fl6->fl6_dport;
2505 			hash_keys.basic.ip_proto = fl6->flowi6_proto;
2506 		}
2507 		mhash = flow_hash_from_keys(&hash_keys);
2508 		break;
2509 	case 2:
2510 		memset(&hash_keys, 0, sizeof(hash_keys));
2511 		hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2512 		if (skb) {
2513 			struct flow_keys keys;
2514 
2515 			if (!flkeys) {
2516 				skb_flow_dissect_flow_keys(skb, &keys, 0);
2517 				flkeys = &keys;
2518 			}
2519 
2520 			/* Inner can be v4 or v6 */
2521 			if (flkeys->control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) {
2522 				hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
2523 				hash_keys.addrs.v4addrs.src = flkeys->addrs.v4addrs.src;
2524 				hash_keys.addrs.v4addrs.dst = flkeys->addrs.v4addrs.dst;
2525 			} else if (flkeys->control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) {
2526 				hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2527 				hash_keys.addrs.v6addrs.src = flkeys->addrs.v6addrs.src;
2528 				hash_keys.addrs.v6addrs.dst = flkeys->addrs.v6addrs.dst;
2529 				hash_keys.tags.flow_label = flkeys->tags.flow_label;
2530 				hash_keys.basic.ip_proto = flkeys->basic.ip_proto;
2531 			} else {
2532 				/* Same as case 0 */
2533 				hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2534 				ip6_multipath_l3_keys(skb, &hash_keys, flkeys);
2535 			}
2536 		} else {
2537 			/* Same as case 0 */
2538 			hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2539 			hash_keys.addrs.v6addrs.src = fl6->saddr;
2540 			hash_keys.addrs.v6addrs.dst = fl6->daddr;
2541 			hash_keys.tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6);
2542 			hash_keys.basic.ip_proto = fl6->flowi6_proto;
2543 		}
2544 		mhash = flow_hash_from_keys(&hash_keys);
2545 		break;
2546 	case 3:
2547 		if (skb)
2548 			mhash = rt6_multipath_custom_hash_skb(net, skb);
2549 		else
2550 			mhash = rt6_multipath_custom_hash_fl6(net, fl6);
2551 		break;
2552 	}
2553 
2554 	return mhash >> 1;
2555 }
2556 
2557 /* Called with rcu held */
ip6_route_input(struct sk_buff * skb)2558 void ip6_route_input(struct sk_buff *skb)
2559 {
2560 	const struct ipv6hdr *iph = ipv6_hdr(skb);
2561 	struct net *net = dev_net(skb->dev);
2562 	int flags = RT6_LOOKUP_F_HAS_SADDR | RT6_LOOKUP_F_DST_NOREF;
2563 	struct ip_tunnel_info *tun_info;
2564 	struct flowi6 fl6 = {
2565 		.flowi6_iif = skb->dev->ifindex,
2566 		.daddr = iph->daddr,
2567 		.saddr = iph->saddr,
2568 		.flowlabel = ip6_flowinfo(iph),
2569 		.flowi6_mark = skb->mark,
2570 		.flowi6_proto = iph->nexthdr,
2571 	};
2572 	struct flow_keys *flkeys = NULL, _flkeys;
2573 
2574 	tun_info = skb_tunnel_info(skb);
2575 	if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX))
2576 		fl6.flowi6_tun_key.tun_id = tun_info->key.tun_id;
2577 
2578 	if (fib6_rules_early_flow_dissect(net, skb, &fl6, &_flkeys))
2579 		flkeys = &_flkeys;
2580 
2581 	if (unlikely(fl6.flowi6_proto == IPPROTO_ICMPV6))
2582 		fl6.mp_hash = rt6_multipath_hash(net, &fl6, skb, flkeys);
2583 	skb_dst_drop(skb);
2584 	skb_dst_set_noref(skb, ip6_route_input_lookup(net, skb->dev,
2585 						      &fl6, skb, flags));
2586 }
2587 
ip6_pol_route_output(struct net * net,struct fib6_table * table,struct flowi6 * fl6,const struct sk_buff * skb,int flags)2588 INDIRECT_CALLABLE_SCOPE struct rt6_info *ip6_pol_route_output(struct net *net,
2589 					     struct fib6_table *table,
2590 					     struct flowi6 *fl6,
2591 					     const struct sk_buff *skb,
2592 					     int flags)
2593 {
2594 	return ip6_pol_route(net, table, fl6->flowi6_oif, fl6, skb, flags);
2595 }
2596 
ip6_route_output_flags_noref(struct net * net,const struct sock * sk,struct flowi6 * fl6,int flags)2597 static struct dst_entry *ip6_route_output_flags_noref(struct net *net,
2598 						      const struct sock *sk,
2599 						      struct flowi6 *fl6,
2600 						      int flags)
2601 {
2602 	bool any_src;
2603 
2604 	if (ipv6_addr_type(&fl6->daddr) &
2605 	    (IPV6_ADDR_MULTICAST | IPV6_ADDR_LINKLOCAL)) {
2606 		struct dst_entry *dst;
2607 
2608 		/* This function does not take refcnt on the dst */
2609 		dst = l3mdev_link_scope_lookup(net, fl6);
2610 		if (dst)
2611 			return dst;
2612 	}
2613 
2614 	fl6->flowi6_iif = LOOPBACK_IFINDEX;
2615 
2616 	flags |= RT6_LOOKUP_F_DST_NOREF;
2617 	any_src = ipv6_addr_any(&fl6->saddr);
2618 	if ((sk && sk->sk_bound_dev_if) || rt6_need_strict(&fl6->daddr) ||
2619 	    (fl6->flowi6_oif && any_src))
2620 		flags |= RT6_LOOKUP_F_IFACE;
2621 
2622 	if (!any_src)
2623 		flags |= RT6_LOOKUP_F_HAS_SADDR;
2624 	else if (sk)
2625 		flags |= rt6_srcprefs2flags(inet6_sk(sk)->srcprefs);
2626 
2627 	return fib6_rule_lookup(net, fl6, NULL, flags, ip6_pol_route_output);
2628 }
2629 
ip6_route_output_flags(struct net * net,const struct sock * sk,struct flowi6 * fl6,int flags)2630 struct dst_entry *ip6_route_output_flags(struct net *net,
2631 					 const struct sock *sk,
2632 					 struct flowi6 *fl6,
2633 					 int flags)
2634 {
2635 	struct dst_entry *dst;
2636 	struct rt6_info *rt6;
2637 
2638 	rcu_read_lock();
2639 	dst = ip6_route_output_flags_noref(net, sk, fl6, flags);
2640 	rt6 = (struct rt6_info *)dst;
2641 	/* For dst cached in uncached_list, refcnt is already taken. */
2642 	if (list_empty(&rt6->dst.rt_uncached) && !dst_hold_safe(dst)) {
2643 		dst = &net->ipv6.ip6_null_entry->dst;
2644 		dst_hold(dst);
2645 	}
2646 	rcu_read_unlock();
2647 
2648 	return dst;
2649 }
2650 EXPORT_SYMBOL_GPL(ip6_route_output_flags);
2651 
ip6_blackhole_route(struct net * net,struct dst_entry * dst_orig)2652 struct dst_entry *ip6_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2653 {
2654 	struct rt6_info *rt, *ort = (struct rt6_info *) dst_orig;
2655 	struct net_device *loopback_dev = net->loopback_dev;
2656 	struct dst_entry *new = NULL;
2657 
2658 	rt = dst_alloc(&ip6_dst_blackhole_ops, loopback_dev, 1,
2659 		       DST_OBSOLETE_DEAD, 0);
2660 	if (rt) {
2661 		rt6_info_init(rt);
2662 		atomic_inc(&net->ipv6.rt6_stats->fib_rt_alloc);
2663 
2664 		new = &rt->dst;
2665 		new->__use = 1;
2666 		new->input = dst_discard;
2667 		new->output = dst_discard_out;
2668 
2669 		dst_copy_metrics(new, &ort->dst);
2670 
2671 		rt->rt6i_idev = in6_dev_get(loopback_dev);
2672 		rt->rt6i_gateway = ort->rt6i_gateway;
2673 		rt->rt6i_flags = ort->rt6i_flags & ~RTF_PCPU;
2674 
2675 		memcpy(&rt->rt6i_dst, &ort->rt6i_dst, sizeof(struct rt6key));
2676 #ifdef CONFIG_IPV6_SUBTREES
2677 		memcpy(&rt->rt6i_src, &ort->rt6i_src, sizeof(struct rt6key));
2678 #endif
2679 	}
2680 
2681 	dst_release(dst_orig);
2682 	return new ? new : ERR_PTR(-ENOMEM);
2683 }
2684 
2685 /*
2686  *	Destination cache support functions
2687  */
2688 
fib6_check(struct fib6_info * f6i,u32 cookie)2689 static bool fib6_check(struct fib6_info *f6i, u32 cookie)
2690 {
2691 	u32 rt_cookie = 0;
2692 
2693 	if (!fib6_get_cookie_safe(f6i, &rt_cookie) || rt_cookie != cookie)
2694 		return false;
2695 
2696 	if (fib6_check_expired(f6i))
2697 		return false;
2698 
2699 	return true;
2700 }
2701 
rt6_check(struct rt6_info * rt,struct fib6_info * from,u32 cookie)2702 static struct dst_entry *rt6_check(struct rt6_info *rt,
2703 				   struct fib6_info *from,
2704 				   u32 cookie)
2705 {
2706 	u32 rt_cookie = 0;
2707 
2708 	if (!from || !fib6_get_cookie_safe(from, &rt_cookie) ||
2709 	    rt_cookie != cookie)
2710 		return NULL;
2711 
2712 	if (rt6_check_expired(rt))
2713 		return NULL;
2714 
2715 	return &rt->dst;
2716 }
2717 
rt6_dst_from_check(struct rt6_info * rt,struct fib6_info * from,u32 cookie)2718 static struct dst_entry *rt6_dst_from_check(struct rt6_info *rt,
2719 					    struct fib6_info *from,
2720 					    u32 cookie)
2721 {
2722 	if (!__rt6_check_expired(rt) &&
2723 	    rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK &&
2724 	    fib6_check(from, cookie))
2725 		return &rt->dst;
2726 	else
2727 		return NULL;
2728 }
2729 
ip6_dst_check(struct dst_entry * dst,u32 cookie)2730 INDIRECT_CALLABLE_SCOPE struct dst_entry *ip6_dst_check(struct dst_entry *dst,
2731 							u32 cookie)
2732 {
2733 	struct dst_entry *dst_ret;
2734 	struct fib6_info *from;
2735 	struct rt6_info *rt;
2736 
2737 	rt = container_of(dst, struct rt6_info, dst);
2738 
2739 	if (rt->sernum)
2740 		return rt6_is_valid(rt) ? dst : NULL;
2741 
2742 	rcu_read_lock();
2743 
2744 	/* All IPV6 dsts are created with ->obsolete set to the value
2745 	 * DST_OBSOLETE_FORCE_CHK which forces validation calls down
2746 	 * into this function always.
2747 	 */
2748 
2749 	from = rcu_dereference(rt->from);
2750 
2751 	if (from && (rt->rt6i_flags & RTF_PCPU ||
2752 	    unlikely(!list_empty(&rt->dst.rt_uncached))))
2753 		dst_ret = rt6_dst_from_check(rt, from, cookie);
2754 	else
2755 		dst_ret = rt6_check(rt, from, cookie);
2756 
2757 	rcu_read_unlock();
2758 
2759 	return dst_ret;
2760 }
2761 EXPORT_INDIRECT_CALLABLE(ip6_dst_check);
2762 
ip6_negative_advice(struct dst_entry * dst)2763 static struct dst_entry *ip6_negative_advice(struct dst_entry *dst)
2764 {
2765 	struct rt6_info *rt = (struct rt6_info *) dst;
2766 
2767 	if (rt) {
2768 		if (rt->rt6i_flags & RTF_CACHE) {
2769 			rcu_read_lock();
2770 			if (rt6_check_expired(rt)) {
2771 				rt6_remove_exception_rt(rt);
2772 				dst = NULL;
2773 			}
2774 			rcu_read_unlock();
2775 		} else {
2776 			dst_release(dst);
2777 			dst = NULL;
2778 		}
2779 	}
2780 	return dst;
2781 }
2782 
ip6_link_failure(struct sk_buff * skb)2783 static void ip6_link_failure(struct sk_buff *skb)
2784 {
2785 	struct rt6_info *rt;
2786 
2787 	icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH, 0);
2788 
2789 	rt = (struct rt6_info *) skb_dst(skb);
2790 	if (rt) {
2791 		rcu_read_lock();
2792 		if (rt->rt6i_flags & RTF_CACHE) {
2793 			rt6_remove_exception_rt(rt);
2794 		} else {
2795 			struct fib6_info *from;
2796 			struct fib6_node *fn;
2797 
2798 			from = rcu_dereference(rt->from);
2799 			if (from) {
2800 				fn = rcu_dereference(from->fib6_node);
2801 				if (fn && (rt->rt6i_flags & RTF_DEFAULT))
2802 					WRITE_ONCE(fn->fn_sernum, -1);
2803 			}
2804 		}
2805 		rcu_read_unlock();
2806 	}
2807 }
2808 
rt6_update_expires(struct rt6_info * rt0,int timeout)2809 static void rt6_update_expires(struct rt6_info *rt0, int timeout)
2810 {
2811 	if (!(rt0->rt6i_flags & RTF_EXPIRES)) {
2812 		struct fib6_info *from;
2813 
2814 		rcu_read_lock();
2815 		from = rcu_dereference(rt0->from);
2816 		if (from)
2817 			rt0->dst.expires = from->expires;
2818 		rcu_read_unlock();
2819 	}
2820 
2821 	dst_set_expires(&rt0->dst, timeout);
2822 	rt0->rt6i_flags |= RTF_EXPIRES;
2823 }
2824 
rt6_do_update_pmtu(struct rt6_info * rt,u32 mtu)2825 static void rt6_do_update_pmtu(struct rt6_info *rt, u32 mtu)
2826 {
2827 	struct net *net = dev_net(rt->dst.dev);
2828 
2829 	dst_metric_set(&rt->dst, RTAX_MTU, mtu);
2830 	rt->rt6i_flags |= RTF_MODIFIED;
2831 	rt6_update_expires(rt, net->ipv6.sysctl.ip6_rt_mtu_expires);
2832 }
2833 
rt6_cache_allowed_for_pmtu(const struct rt6_info * rt)2834 static bool rt6_cache_allowed_for_pmtu(const struct rt6_info *rt)
2835 {
2836 	return !(rt->rt6i_flags & RTF_CACHE) &&
2837 		(rt->rt6i_flags & RTF_PCPU || rcu_access_pointer(rt->from));
2838 }
2839 
__ip6_rt_update_pmtu(struct dst_entry * dst,const struct sock * sk,const struct ipv6hdr * iph,u32 mtu,bool confirm_neigh)2840 static void __ip6_rt_update_pmtu(struct dst_entry *dst, const struct sock *sk,
2841 				 const struct ipv6hdr *iph, u32 mtu,
2842 				 bool confirm_neigh)
2843 {
2844 	const struct in6_addr *daddr, *saddr;
2845 	struct rt6_info *rt6 = (struct rt6_info *)dst;
2846 
2847 	/* Note: do *NOT* check dst_metric_locked(dst, RTAX_MTU)
2848 	 * IPv6 pmtu discovery isn't optional, so 'mtu lock' cannot disable it.
2849 	 * [see also comment in rt6_mtu_change_route()]
2850 	 */
2851 
2852 	if (iph) {
2853 		daddr = &iph->daddr;
2854 		saddr = &iph->saddr;
2855 	} else if (sk) {
2856 		daddr = &sk->sk_v6_daddr;
2857 		saddr = &inet6_sk(sk)->saddr;
2858 	} else {
2859 		daddr = NULL;
2860 		saddr = NULL;
2861 	}
2862 
2863 	if (confirm_neigh)
2864 		dst_confirm_neigh(dst, daddr);
2865 
2866 	if (mtu < IPV6_MIN_MTU)
2867 		return;
2868 	if (mtu >= dst_mtu(dst))
2869 		return;
2870 
2871 	if (!rt6_cache_allowed_for_pmtu(rt6)) {
2872 		rt6_do_update_pmtu(rt6, mtu);
2873 		/* update rt6_ex->stamp for cache */
2874 		if (rt6->rt6i_flags & RTF_CACHE)
2875 			rt6_update_exception_stamp_rt(rt6);
2876 	} else if (daddr) {
2877 		struct fib6_result res = {};
2878 		struct rt6_info *nrt6;
2879 
2880 		rcu_read_lock();
2881 		res.f6i = rcu_dereference(rt6->from);
2882 		if (!res.f6i)
2883 			goto out_unlock;
2884 
2885 		res.fib6_flags = res.f6i->fib6_flags;
2886 		res.fib6_type = res.f6i->fib6_type;
2887 
2888 		if (res.f6i->nh) {
2889 			struct fib6_nh_match_arg arg = {
2890 				.dev = dst->dev,
2891 				.gw = &rt6->rt6i_gateway,
2892 			};
2893 
2894 			nexthop_for_each_fib6_nh(res.f6i->nh,
2895 						 fib6_nh_find_match, &arg);
2896 
2897 			/* fib6_info uses a nexthop that does not have fib6_nh
2898 			 * using the dst->dev + gw. Should be impossible.
2899 			 */
2900 			if (!arg.match)
2901 				goto out_unlock;
2902 
2903 			res.nh = arg.match;
2904 		} else {
2905 			res.nh = res.f6i->fib6_nh;
2906 		}
2907 
2908 		nrt6 = ip6_rt_cache_alloc(&res, daddr, saddr);
2909 		if (nrt6) {
2910 			rt6_do_update_pmtu(nrt6, mtu);
2911 			if (rt6_insert_exception(nrt6, &res))
2912 				dst_release_immediate(&nrt6->dst);
2913 		}
2914 out_unlock:
2915 		rcu_read_unlock();
2916 	}
2917 }
2918 
ip6_rt_update_pmtu(struct dst_entry * dst,struct sock * sk,struct sk_buff * skb,u32 mtu,bool confirm_neigh)2919 static void ip6_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
2920 			       struct sk_buff *skb, u32 mtu,
2921 			       bool confirm_neigh)
2922 {
2923 	__ip6_rt_update_pmtu(dst, sk, skb ? ipv6_hdr(skb) : NULL, mtu,
2924 			     confirm_neigh);
2925 }
2926 
ip6_update_pmtu(struct sk_buff * skb,struct net * net,__be32 mtu,int oif,u32 mark,kuid_t uid)2927 void ip6_update_pmtu(struct sk_buff *skb, struct net *net, __be32 mtu,
2928 		     int oif, u32 mark, kuid_t uid)
2929 {
2930 	const struct ipv6hdr *iph = (struct ipv6hdr *) skb->data;
2931 	struct dst_entry *dst;
2932 	struct flowi6 fl6 = {
2933 		.flowi6_oif = oif,
2934 		.flowi6_mark = mark ? mark : IP6_REPLY_MARK(net, skb->mark),
2935 		.daddr = iph->daddr,
2936 		.saddr = iph->saddr,
2937 		.flowlabel = ip6_flowinfo(iph),
2938 		.flowi6_uid = uid,
2939 	};
2940 
2941 	dst = ip6_route_output(net, NULL, &fl6);
2942 	if (!dst->error)
2943 		__ip6_rt_update_pmtu(dst, NULL, iph, ntohl(mtu), true);
2944 	dst_release(dst);
2945 }
2946 EXPORT_SYMBOL_GPL(ip6_update_pmtu);
2947 
ip6_sk_update_pmtu(struct sk_buff * skb,struct sock * sk,__be32 mtu)2948 void ip6_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, __be32 mtu)
2949 {
2950 	int oif = sk->sk_bound_dev_if;
2951 	struct dst_entry *dst;
2952 
2953 	if (!oif && skb->dev)
2954 		oif = l3mdev_master_ifindex(skb->dev);
2955 
2956 	ip6_update_pmtu(skb, sock_net(sk), mtu, oif, READ_ONCE(sk->sk_mark),
2957 			sk->sk_uid);
2958 
2959 	dst = __sk_dst_get(sk);
2960 	if (!dst || !dst->obsolete ||
2961 	    dst->ops->check(dst, inet6_sk(sk)->dst_cookie))
2962 		return;
2963 
2964 	bh_lock_sock(sk);
2965 	if (!sock_owned_by_user(sk) && !ipv6_addr_v4mapped(&sk->sk_v6_daddr))
2966 		ip6_datagram_dst_update(sk, false);
2967 	bh_unlock_sock(sk);
2968 }
2969 EXPORT_SYMBOL_GPL(ip6_sk_update_pmtu);
2970 
ip6_sk_dst_store_flow(struct sock * sk,struct dst_entry * dst,const struct flowi6 * fl6)2971 void ip6_sk_dst_store_flow(struct sock *sk, struct dst_entry *dst,
2972 			   const struct flowi6 *fl6)
2973 {
2974 #ifdef CONFIG_IPV6_SUBTREES
2975 	struct ipv6_pinfo *np = inet6_sk(sk);
2976 #endif
2977 
2978 	ip6_dst_store(sk, dst,
2979 		      ipv6_addr_equal(&fl6->daddr, &sk->sk_v6_daddr) ?
2980 		      &sk->sk_v6_daddr : NULL,
2981 #ifdef CONFIG_IPV6_SUBTREES
2982 		      ipv6_addr_equal(&fl6->saddr, &np->saddr) ?
2983 		      &np->saddr :
2984 #endif
2985 		      NULL);
2986 }
2987 
ip6_redirect_nh_match(const struct fib6_result * res,struct flowi6 * fl6,const struct in6_addr * gw,struct rt6_info ** ret)2988 static bool ip6_redirect_nh_match(const struct fib6_result *res,
2989 				  struct flowi6 *fl6,
2990 				  const struct in6_addr *gw,
2991 				  struct rt6_info **ret)
2992 {
2993 	const struct fib6_nh *nh = res->nh;
2994 
2995 	if (nh->fib_nh_flags & RTNH_F_DEAD || !nh->fib_nh_gw_family ||
2996 	    fl6->flowi6_oif != nh->fib_nh_dev->ifindex)
2997 		return false;
2998 
2999 	/* rt_cache's gateway might be different from its 'parent'
3000 	 * in the case of an ip redirect.
3001 	 * So we keep searching in the exception table if the gateway
3002 	 * is different.
3003 	 */
3004 	if (!ipv6_addr_equal(gw, &nh->fib_nh_gw6)) {
3005 		struct rt6_info *rt_cache;
3006 
3007 		rt_cache = rt6_find_cached_rt(res, &fl6->daddr, &fl6->saddr);
3008 		if (rt_cache &&
3009 		    ipv6_addr_equal(gw, &rt_cache->rt6i_gateway)) {
3010 			*ret = rt_cache;
3011 			return true;
3012 		}
3013 		return false;
3014 	}
3015 	return true;
3016 }
3017 
3018 struct fib6_nh_rd_arg {
3019 	struct fib6_result	*res;
3020 	struct flowi6		*fl6;
3021 	const struct in6_addr	*gw;
3022 	struct rt6_info		**ret;
3023 };
3024 
fib6_nh_redirect_match(struct fib6_nh * nh,void * _arg)3025 static int fib6_nh_redirect_match(struct fib6_nh *nh, void *_arg)
3026 {
3027 	struct fib6_nh_rd_arg *arg = _arg;
3028 
3029 	arg->res->nh = nh;
3030 	return ip6_redirect_nh_match(arg->res, arg->fl6, arg->gw, arg->ret);
3031 }
3032 
3033 /* Handle redirects */
3034 struct ip6rd_flowi {
3035 	struct flowi6 fl6;
3036 	struct in6_addr gateway;
3037 };
3038 
__ip6_route_redirect(struct net * net,struct fib6_table * table,struct flowi6 * fl6,const struct sk_buff * skb,int flags)3039 INDIRECT_CALLABLE_SCOPE struct rt6_info *__ip6_route_redirect(struct net *net,
3040 					     struct fib6_table *table,
3041 					     struct flowi6 *fl6,
3042 					     const struct sk_buff *skb,
3043 					     int flags)
3044 {
3045 	struct ip6rd_flowi *rdfl = (struct ip6rd_flowi *)fl6;
3046 	struct rt6_info *ret = NULL;
3047 	struct fib6_result res = {};
3048 	struct fib6_nh_rd_arg arg = {
3049 		.res = &res,
3050 		.fl6 = fl6,
3051 		.gw  = &rdfl->gateway,
3052 		.ret = &ret
3053 	};
3054 	struct fib6_info *rt;
3055 	struct fib6_node *fn;
3056 
3057 	/* Get the "current" route for this destination and
3058 	 * check if the redirect has come from appropriate router.
3059 	 *
3060 	 * RFC 4861 specifies that redirects should only be
3061 	 * accepted if they come from the nexthop to the target.
3062 	 * Due to the way the routes are chosen, this notion
3063 	 * is a bit fuzzy and one might need to check all possible
3064 	 * routes.
3065 	 */
3066 
3067 	rcu_read_lock();
3068 	fn = fib6_node_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr);
3069 restart:
3070 	for_each_fib6_node_rt_rcu(fn) {
3071 		res.f6i = rt;
3072 		if (fib6_check_expired(rt))
3073 			continue;
3074 		if (rt->fib6_flags & RTF_REJECT)
3075 			break;
3076 		if (unlikely(rt->nh)) {
3077 			if (nexthop_is_blackhole(rt->nh))
3078 				continue;
3079 			/* on match, res->nh is filled in and potentially ret */
3080 			if (nexthop_for_each_fib6_nh(rt->nh,
3081 						     fib6_nh_redirect_match,
3082 						     &arg))
3083 				goto out;
3084 		} else {
3085 			res.nh = rt->fib6_nh;
3086 			if (ip6_redirect_nh_match(&res, fl6, &rdfl->gateway,
3087 						  &ret))
3088 				goto out;
3089 		}
3090 	}
3091 
3092 	if (!rt)
3093 		rt = net->ipv6.fib6_null_entry;
3094 	else if (rt->fib6_flags & RTF_REJECT) {
3095 		ret = net->ipv6.ip6_null_entry;
3096 		goto out;
3097 	}
3098 
3099 	if (rt == net->ipv6.fib6_null_entry) {
3100 		fn = fib6_backtrack(fn, &fl6->saddr);
3101 		if (fn)
3102 			goto restart;
3103 	}
3104 
3105 	res.f6i = rt;
3106 	res.nh = rt->fib6_nh;
3107 out:
3108 	if (ret) {
3109 		ip6_hold_safe(net, &ret);
3110 	} else {
3111 		res.fib6_flags = res.f6i->fib6_flags;
3112 		res.fib6_type = res.f6i->fib6_type;
3113 		ret = ip6_create_rt_rcu(&res);
3114 	}
3115 
3116 	rcu_read_unlock();
3117 
3118 	trace_fib6_table_lookup(net, &res, table, fl6);
3119 	return ret;
3120 };
3121 
ip6_route_redirect(struct net * net,const struct flowi6 * fl6,const struct sk_buff * skb,const struct in6_addr * gateway)3122 static struct dst_entry *ip6_route_redirect(struct net *net,
3123 					    const struct flowi6 *fl6,
3124 					    const struct sk_buff *skb,
3125 					    const struct in6_addr *gateway)
3126 {
3127 	int flags = RT6_LOOKUP_F_HAS_SADDR;
3128 	struct ip6rd_flowi rdfl;
3129 
3130 	rdfl.fl6 = *fl6;
3131 	rdfl.gateway = *gateway;
3132 
3133 	return fib6_rule_lookup(net, &rdfl.fl6, skb,
3134 				flags, __ip6_route_redirect);
3135 }
3136 
ip6_redirect(struct sk_buff * skb,struct net * net,int oif,u32 mark,kuid_t uid)3137 void ip6_redirect(struct sk_buff *skb, struct net *net, int oif, u32 mark,
3138 		  kuid_t uid)
3139 {
3140 	const struct ipv6hdr *iph = (struct ipv6hdr *) skb->data;
3141 	struct dst_entry *dst;
3142 	struct flowi6 fl6 = {
3143 		.flowi6_iif = LOOPBACK_IFINDEX,
3144 		.flowi6_oif = oif,
3145 		.flowi6_mark = mark,
3146 		.daddr = iph->daddr,
3147 		.saddr = iph->saddr,
3148 		.flowlabel = ip6_flowinfo(iph),
3149 		.flowi6_uid = uid,
3150 	};
3151 
3152 	dst = ip6_route_redirect(net, &fl6, skb, &ipv6_hdr(skb)->saddr);
3153 	rt6_do_redirect(dst, NULL, skb);
3154 	dst_release(dst);
3155 }
3156 EXPORT_SYMBOL_GPL(ip6_redirect);
3157 
ip6_redirect_no_header(struct sk_buff * skb,struct net * net,int oif)3158 void ip6_redirect_no_header(struct sk_buff *skb, struct net *net, int oif)
3159 {
3160 	const struct ipv6hdr *iph = ipv6_hdr(skb);
3161 	const struct rd_msg *msg = (struct rd_msg *)icmp6_hdr(skb);
3162 	struct dst_entry *dst;
3163 	struct flowi6 fl6 = {
3164 		.flowi6_iif = LOOPBACK_IFINDEX,
3165 		.flowi6_oif = oif,
3166 		.daddr = msg->dest,
3167 		.saddr = iph->daddr,
3168 		.flowi6_uid = sock_net_uid(net, NULL),
3169 	};
3170 
3171 	dst = ip6_route_redirect(net, &fl6, skb, &iph->saddr);
3172 	rt6_do_redirect(dst, NULL, skb);
3173 	dst_release(dst);
3174 }
3175 
ip6_sk_redirect(struct sk_buff * skb,struct sock * sk)3176 void ip6_sk_redirect(struct sk_buff *skb, struct sock *sk)
3177 {
3178 	ip6_redirect(skb, sock_net(sk), sk->sk_bound_dev_if,
3179 		     READ_ONCE(sk->sk_mark), sk->sk_uid);
3180 }
3181 EXPORT_SYMBOL_GPL(ip6_sk_redirect);
3182 
ip6_default_advmss(const struct dst_entry * dst)3183 static unsigned int ip6_default_advmss(const struct dst_entry *dst)
3184 {
3185 	struct net_device *dev = dst->dev;
3186 	unsigned int mtu = dst_mtu(dst);
3187 	struct net *net = dev_net(dev);
3188 
3189 	mtu -= sizeof(struct ipv6hdr) + sizeof(struct tcphdr);
3190 
3191 	if (mtu < net->ipv6.sysctl.ip6_rt_min_advmss)
3192 		mtu = net->ipv6.sysctl.ip6_rt_min_advmss;
3193 
3194 	/*
3195 	 * Maximal non-jumbo IPv6 payload is IPV6_MAXPLEN and
3196 	 * corresponding MSS is IPV6_MAXPLEN - tcp_header_size.
3197 	 * IPV6_MAXPLEN is also valid and means: "any MSS,
3198 	 * rely only on pmtu discovery"
3199 	 */
3200 	if (mtu > IPV6_MAXPLEN - sizeof(struct tcphdr))
3201 		mtu = IPV6_MAXPLEN;
3202 	return mtu;
3203 }
3204 
ip6_mtu(const struct dst_entry * dst)3205 INDIRECT_CALLABLE_SCOPE unsigned int ip6_mtu(const struct dst_entry *dst)
3206 {
3207 	return ip6_dst_mtu_maybe_forward(dst, false);
3208 }
3209 EXPORT_INDIRECT_CALLABLE(ip6_mtu);
3210 
3211 /* MTU selection:
3212  * 1. mtu on route is locked - use it
3213  * 2. mtu from nexthop exception
3214  * 3. mtu from egress device
3215  *
3216  * based on ip6_dst_mtu_forward and exception logic of
3217  * rt6_find_cached_rt; called with rcu_read_lock
3218  */
ip6_mtu_from_fib6(const struct fib6_result * res,const struct in6_addr * daddr,const struct in6_addr * saddr)3219 u32 ip6_mtu_from_fib6(const struct fib6_result *res,
3220 		      const struct in6_addr *daddr,
3221 		      const struct in6_addr *saddr)
3222 {
3223 	const struct fib6_nh *nh = res->nh;
3224 	struct fib6_info *f6i = res->f6i;
3225 	struct inet6_dev *idev;
3226 	struct rt6_info *rt;
3227 	u32 mtu = 0;
3228 
3229 	if (unlikely(fib6_metric_locked(f6i, RTAX_MTU))) {
3230 		mtu = f6i->fib6_pmtu;
3231 		if (mtu)
3232 			goto out;
3233 	}
3234 
3235 	rt = rt6_find_cached_rt(res, daddr, saddr);
3236 	if (unlikely(rt)) {
3237 		mtu = dst_metric_raw(&rt->dst, RTAX_MTU);
3238 	} else {
3239 		struct net_device *dev = nh->fib_nh_dev;
3240 
3241 		mtu = IPV6_MIN_MTU;
3242 		idev = __in6_dev_get(dev);
3243 		if (idev && idev->cnf.mtu6 > mtu)
3244 			mtu = idev->cnf.mtu6;
3245 	}
3246 
3247 	mtu = min_t(unsigned int, mtu, IP6_MAX_MTU);
3248 out:
3249 	return mtu - lwtunnel_headroom(nh->fib_nh_lws, mtu);
3250 }
3251 
icmp6_dst_alloc(struct net_device * dev,struct flowi6 * fl6)3252 struct dst_entry *icmp6_dst_alloc(struct net_device *dev,
3253 				  struct flowi6 *fl6)
3254 {
3255 	struct dst_entry *dst;
3256 	struct rt6_info *rt;
3257 	struct inet6_dev *idev = in6_dev_get(dev);
3258 	struct net *net = dev_net(dev);
3259 
3260 	if (unlikely(!idev))
3261 		return ERR_PTR(-ENODEV);
3262 
3263 	rt = ip6_dst_alloc(net, dev, 0);
3264 	if (unlikely(!rt)) {
3265 		in6_dev_put(idev);
3266 		dst = ERR_PTR(-ENOMEM);
3267 		goto out;
3268 	}
3269 
3270 	rt->dst.input = ip6_input;
3271 	rt->dst.output  = ip6_output;
3272 	rt->rt6i_gateway  = fl6->daddr;
3273 	rt->rt6i_dst.addr = fl6->daddr;
3274 	rt->rt6i_dst.plen = 128;
3275 	rt->rt6i_idev     = idev;
3276 	dst_metric_set(&rt->dst, RTAX_HOPLIMIT, 0);
3277 
3278 	/* Add this dst into uncached_list so that rt6_disable_ip() can
3279 	 * do proper release of the net_device
3280 	 */
3281 	rt6_uncached_list_add(rt);
3282 
3283 	dst = xfrm_lookup(net, &rt->dst, flowi6_to_flowi(fl6), NULL, 0);
3284 
3285 out:
3286 	return dst;
3287 }
3288 
ip6_dst_gc(struct dst_ops * ops)3289 static void ip6_dst_gc(struct dst_ops *ops)
3290 {
3291 	struct net *net = container_of(ops, struct net, ipv6.ip6_dst_ops);
3292 	int rt_min_interval = net->ipv6.sysctl.ip6_rt_gc_min_interval;
3293 	int rt_elasticity = net->ipv6.sysctl.ip6_rt_gc_elasticity;
3294 	int rt_gc_timeout = net->ipv6.sysctl.ip6_rt_gc_timeout;
3295 	unsigned long rt_last_gc = net->ipv6.ip6_rt_last_gc;
3296 	unsigned int val;
3297 	int entries;
3298 
3299 	if (time_after(rt_last_gc + rt_min_interval, jiffies))
3300 		goto out;
3301 
3302 	fib6_run_gc(atomic_inc_return(&net->ipv6.ip6_rt_gc_expire), net, true);
3303 	entries = dst_entries_get_slow(ops);
3304 	if (entries < ops->gc_thresh)
3305 		atomic_set(&net->ipv6.ip6_rt_gc_expire, rt_gc_timeout >> 1);
3306 out:
3307 	val = atomic_read(&net->ipv6.ip6_rt_gc_expire);
3308 	atomic_set(&net->ipv6.ip6_rt_gc_expire, val - (val >> rt_elasticity));
3309 }
3310 
ip6_nh_lookup_table(struct net * net,struct fib6_config * cfg,const struct in6_addr * gw_addr,u32 tbid,int flags,struct fib6_result * res)3311 static int ip6_nh_lookup_table(struct net *net, struct fib6_config *cfg,
3312 			       const struct in6_addr *gw_addr, u32 tbid,
3313 			       int flags, struct fib6_result *res)
3314 {
3315 	struct flowi6 fl6 = {
3316 		.flowi6_oif = cfg->fc_ifindex,
3317 		.daddr = *gw_addr,
3318 		.saddr = cfg->fc_prefsrc,
3319 	};
3320 	struct fib6_table *table;
3321 	int err;
3322 
3323 	table = fib6_get_table(net, tbid);
3324 	if (!table)
3325 		return -EINVAL;
3326 
3327 	if (!ipv6_addr_any(&cfg->fc_prefsrc))
3328 		flags |= RT6_LOOKUP_F_HAS_SADDR;
3329 
3330 	flags |= RT6_LOOKUP_F_IGNORE_LINKSTATE;
3331 
3332 	err = fib6_table_lookup(net, table, cfg->fc_ifindex, &fl6, res, flags);
3333 	if (!err && res->f6i != net->ipv6.fib6_null_entry)
3334 		fib6_select_path(net, res, &fl6, cfg->fc_ifindex,
3335 				 cfg->fc_ifindex != 0, NULL, flags);
3336 
3337 	return err;
3338 }
3339 
ip6_route_check_nh_onlink(struct net * net,struct fib6_config * cfg,const struct net_device * dev,struct netlink_ext_ack * extack)3340 static int ip6_route_check_nh_onlink(struct net *net,
3341 				     struct fib6_config *cfg,
3342 				     const struct net_device *dev,
3343 				     struct netlink_ext_ack *extack)
3344 {
3345 	u32 tbid = l3mdev_fib_table_rcu(dev) ? : RT_TABLE_MAIN;
3346 	const struct in6_addr *gw_addr = &cfg->fc_gateway;
3347 	struct fib6_result res = {};
3348 	int err;
3349 
3350 	err = ip6_nh_lookup_table(net, cfg, gw_addr, tbid, 0, &res);
3351 	if (!err && !(res.fib6_flags & RTF_REJECT) &&
3352 	    /* ignore match if it is the default route */
3353 	    !ipv6_addr_any(&res.f6i->fib6_dst.addr) &&
3354 	    (res.fib6_type != RTN_UNICAST || dev != res.nh->fib_nh_dev)) {
3355 		NL_SET_ERR_MSG(extack,
3356 			       "Nexthop has invalid gateway or device mismatch");
3357 		err = -EINVAL;
3358 	}
3359 
3360 	return err;
3361 }
3362 
ip6_route_check_nh(struct net * net,struct fib6_config * cfg,struct net_device ** _dev,netdevice_tracker * dev_tracker,struct inet6_dev ** idev)3363 static int ip6_route_check_nh(struct net *net,
3364 			      struct fib6_config *cfg,
3365 			      struct net_device **_dev,
3366 			      netdevice_tracker *dev_tracker,
3367 			      struct inet6_dev **idev)
3368 {
3369 	const struct in6_addr *gw_addr = &cfg->fc_gateway;
3370 	struct net_device *dev = _dev ? *_dev : NULL;
3371 	int flags = RT6_LOOKUP_F_IFACE;
3372 	struct fib6_result res = {};
3373 	int err = -EHOSTUNREACH;
3374 
3375 	if (cfg->fc_table) {
3376 		err = ip6_nh_lookup_table(net, cfg, gw_addr,
3377 					  cfg->fc_table, flags, &res);
3378 		/* gw_addr can not require a gateway or resolve to a reject
3379 		 * route. If a device is given, it must match the result.
3380 		 */
3381 		if (err || res.fib6_flags & RTF_REJECT ||
3382 		    res.nh->fib_nh_gw_family ||
3383 		    (dev && dev != res.nh->fib_nh_dev))
3384 			err = -EHOSTUNREACH;
3385 	}
3386 
3387 	if (err < 0) {
3388 		struct flowi6 fl6 = {
3389 			.flowi6_oif = cfg->fc_ifindex,
3390 			.daddr = *gw_addr,
3391 		};
3392 
3393 		err = fib6_lookup(net, cfg->fc_ifindex, &fl6, &res, flags);
3394 		if (err || res.fib6_flags & RTF_REJECT ||
3395 		    res.nh->fib_nh_gw_family)
3396 			err = -EHOSTUNREACH;
3397 
3398 		if (err)
3399 			return err;
3400 
3401 		fib6_select_path(net, &res, &fl6, cfg->fc_ifindex,
3402 				 cfg->fc_ifindex != 0, NULL, flags);
3403 	}
3404 
3405 	err = 0;
3406 	if (dev) {
3407 		if (dev != res.nh->fib_nh_dev)
3408 			err = -EHOSTUNREACH;
3409 	} else {
3410 		*_dev = dev = res.nh->fib_nh_dev;
3411 		netdev_hold(dev, dev_tracker, GFP_ATOMIC);
3412 		*idev = in6_dev_get(dev);
3413 	}
3414 
3415 	return err;
3416 }
3417 
ip6_validate_gw(struct net * net,struct fib6_config * cfg,struct net_device ** _dev,netdevice_tracker * dev_tracker,struct inet6_dev ** idev,struct netlink_ext_ack * extack)3418 static int ip6_validate_gw(struct net *net, struct fib6_config *cfg,
3419 			   struct net_device **_dev,
3420 			   netdevice_tracker *dev_tracker,
3421 			   struct inet6_dev **idev,
3422 			   struct netlink_ext_ack *extack)
3423 {
3424 	const struct in6_addr *gw_addr = &cfg->fc_gateway;
3425 	int gwa_type = ipv6_addr_type(gw_addr);
3426 	bool skip_dev = gwa_type & IPV6_ADDR_LINKLOCAL ? false : true;
3427 	const struct net_device *dev = *_dev;
3428 	bool need_addr_check = !dev;
3429 	int err = -EINVAL;
3430 
3431 	/* if gw_addr is local we will fail to detect this in case
3432 	 * address is still TENTATIVE (DAD in progress). rt6_lookup()
3433 	 * will return already-added prefix route via interface that
3434 	 * prefix route was assigned to, which might be non-loopback.
3435 	 */
3436 	if (dev &&
3437 	    ipv6_chk_addr_and_flags(net, gw_addr, dev, skip_dev, 0, 0)) {
3438 		NL_SET_ERR_MSG(extack, "Gateway can not be a local address");
3439 		goto out;
3440 	}
3441 
3442 	if (gwa_type != (IPV6_ADDR_LINKLOCAL | IPV6_ADDR_UNICAST)) {
3443 		/* IPv6 strictly inhibits using not link-local
3444 		 * addresses as nexthop address.
3445 		 * Otherwise, router will not able to send redirects.
3446 		 * It is very good, but in some (rare!) circumstances
3447 		 * (SIT, PtP, NBMA NOARP links) it is handy to allow
3448 		 * some exceptions. --ANK
3449 		 * We allow IPv4-mapped nexthops to support RFC4798-type
3450 		 * addressing
3451 		 */
3452 		if (!(gwa_type & (IPV6_ADDR_UNICAST | IPV6_ADDR_MAPPED))) {
3453 			NL_SET_ERR_MSG(extack, "Invalid gateway address");
3454 			goto out;
3455 		}
3456 
3457 		rcu_read_lock();
3458 
3459 		if (cfg->fc_flags & RTNH_F_ONLINK)
3460 			err = ip6_route_check_nh_onlink(net, cfg, dev, extack);
3461 		else
3462 			err = ip6_route_check_nh(net, cfg, _dev, dev_tracker,
3463 						 idev);
3464 
3465 		rcu_read_unlock();
3466 
3467 		if (err)
3468 			goto out;
3469 	}
3470 
3471 	/* reload in case device was changed */
3472 	dev = *_dev;
3473 
3474 	err = -EINVAL;
3475 	if (!dev) {
3476 		NL_SET_ERR_MSG(extack, "Egress device not specified");
3477 		goto out;
3478 	} else if (dev->flags & IFF_LOOPBACK) {
3479 		NL_SET_ERR_MSG(extack,
3480 			       "Egress device can not be loopback device for this route");
3481 		goto out;
3482 	}
3483 
3484 	/* if we did not check gw_addr above, do so now that the
3485 	 * egress device has been resolved.
3486 	 */
3487 	if (need_addr_check &&
3488 	    ipv6_chk_addr_and_flags(net, gw_addr, dev, skip_dev, 0, 0)) {
3489 		NL_SET_ERR_MSG(extack, "Gateway can not be a local address");
3490 		goto out;
3491 	}
3492 
3493 	err = 0;
3494 out:
3495 	return err;
3496 }
3497 
fib6_is_reject(u32 flags,struct net_device * dev,int addr_type)3498 static bool fib6_is_reject(u32 flags, struct net_device *dev, int addr_type)
3499 {
3500 	if ((flags & RTF_REJECT) ||
3501 	    (dev && (dev->flags & IFF_LOOPBACK) &&
3502 	     !(addr_type & IPV6_ADDR_LOOPBACK) &&
3503 	     !(flags & (RTF_ANYCAST | RTF_LOCAL))))
3504 		return true;
3505 
3506 	return false;
3507 }
3508 
fib6_nh_init(struct net * net,struct fib6_nh * fib6_nh,struct fib6_config * cfg,gfp_t gfp_flags,struct netlink_ext_ack * extack)3509 int fib6_nh_init(struct net *net, struct fib6_nh *fib6_nh,
3510 		 struct fib6_config *cfg, gfp_t gfp_flags,
3511 		 struct netlink_ext_ack *extack)
3512 {
3513 	netdevice_tracker *dev_tracker = &fib6_nh->fib_nh_dev_tracker;
3514 	struct net_device *dev = NULL;
3515 	struct inet6_dev *idev = NULL;
3516 	int addr_type;
3517 	int err;
3518 
3519 	fib6_nh->fib_nh_family = AF_INET6;
3520 #ifdef CONFIG_IPV6_ROUTER_PREF
3521 	fib6_nh->last_probe = jiffies;
3522 #endif
3523 	if (cfg->fc_is_fdb) {
3524 		fib6_nh->fib_nh_gw6 = cfg->fc_gateway;
3525 		fib6_nh->fib_nh_gw_family = AF_INET6;
3526 		return 0;
3527 	}
3528 
3529 	err = -ENODEV;
3530 	if (cfg->fc_ifindex) {
3531 		dev = netdev_get_by_index(net, cfg->fc_ifindex,
3532 					  dev_tracker, gfp_flags);
3533 		if (!dev)
3534 			goto out;
3535 		idev = in6_dev_get(dev);
3536 		if (!idev)
3537 			goto out;
3538 	}
3539 
3540 	if (cfg->fc_flags & RTNH_F_ONLINK) {
3541 		if (!dev) {
3542 			NL_SET_ERR_MSG(extack,
3543 				       "Nexthop device required for onlink");
3544 			goto out;
3545 		}
3546 
3547 		if (!(dev->flags & IFF_UP)) {
3548 			NL_SET_ERR_MSG(extack, "Nexthop device is not up");
3549 			err = -ENETDOWN;
3550 			goto out;
3551 		}
3552 
3553 		fib6_nh->fib_nh_flags |= RTNH_F_ONLINK;
3554 	}
3555 
3556 	fib6_nh->fib_nh_weight = 1;
3557 
3558 	/* We cannot add true routes via loopback here,
3559 	 * they would result in kernel looping; promote them to reject routes
3560 	 */
3561 	addr_type = ipv6_addr_type(&cfg->fc_dst);
3562 	if (fib6_is_reject(cfg->fc_flags, dev, addr_type)) {
3563 		/* hold loopback dev/idev if we haven't done so. */
3564 		if (dev != net->loopback_dev) {
3565 			if (dev) {
3566 				netdev_put(dev, dev_tracker);
3567 				in6_dev_put(idev);
3568 			}
3569 			dev = net->loopback_dev;
3570 			netdev_hold(dev, dev_tracker, gfp_flags);
3571 			idev = in6_dev_get(dev);
3572 			if (!idev) {
3573 				err = -ENODEV;
3574 				goto out;
3575 			}
3576 		}
3577 		goto pcpu_alloc;
3578 	}
3579 
3580 	if (cfg->fc_flags & RTF_GATEWAY) {
3581 		err = ip6_validate_gw(net, cfg, &dev, dev_tracker,
3582 				      &idev, extack);
3583 		if (err)
3584 			goto out;
3585 
3586 		fib6_nh->fib_nh_gw6 = cfg->fc_gateway;
3587 		fib6_nh->fib_nh_gw_family = AF_INET6;
3588 	}
3589 
3590 	err = -ENODEV;
3591 	if (!dev)
3592 		goto out;
3593 
3594 	if (idev->cnf.disable_ipv6) {
3595 		NL_SET_ERR_MSG(extack, "IPv6 is disabled on nexthop device");
3596 		err = -EACCES;
3597 		goto out;
3598 	}
3599 
3600 	if (!(dev->flags & IFF_UP) && !cfg->fc_ignore_dev_down) {
3601 		NL_SET_ERR_MSG(extack, "Nexthop device is not up");
3602 		err = -ENETDOWN;
3603 		goto out;
3604 	}
3605 
3606 	if (!(cfg->fc_flags & (RTF_LOCAL | RTF_ANYCAST)) &&
3607 	    !netif_carrier_ok(dev))
3608 		fib6_nh->fib_nh_flags |= RTNH_F_LINKDOWN;
3609 
3610 	err = fib_nh_common_init(net, &fib6_nh->nh_common, cfg->fc_encap,
3611 				 cfg->fc_encap_type, cfg, gfp_flags, extack);
3612 	if (err)
3613 		goto out;
3614 
3615 pcpu_alloc:
3616 	fib6_nh->rt6i_pcpu = alloc_percpu_gfp(struct rt6_info *, gfp_flags);
3617 	if (!fib6_nh->rt6i_pcpu) {
3618 		err = -ENOMEM;
3619 		goto out;
3620 	}
3621 
3622 	fib6_nh->fib_nh_dev = dev;
3623 	fib6_nh->fib_nh_oif = dev->ifindex;
3624 	err = 0;
3625 out:
3626 	if (idev)
3627 		in6_dev_put(idev);
3628 
3629 	if (err) {
3630 		lwtstate_put(fib6_nh->fib_nh_lws);
3631 		fib6_nh->fib_nh_lws = NULL;
3632 		netdev_put(dev, dev_tracker);
3633 	}
3634 
3635 	return err;
3636 }
3637 
fib6_nh_release(struct fib6_nh * fib6_nh)3638 void fib6_nh_release(struct fib6_nh *fib6_nh)
3639 {
3640 	struct rt6_exception_bucket *bucket;
3641 
3642 	rcu_read_lock();
3643 
3644 	fib6_nh_flush_exceptions(fib6_nh, NULL);
3645 	bucket = fib6_nh_get_excptn_bucket(fib6_nh, NULL);
3646 	if (bucket) {
3647 		rcu_assign_pointer(fib6_nh->rt6i_exception_bucket, NULL);
3648 		kfree(bucket);
3649 	}
3650 
3651 	rcu_read_unlock();
3652 
3653 	fib6_nh_release_dsts(fib6_nh);
3654 	free_percpu(fib6_nh->rt6i_pcpu);
3655 
3656 	fib_nh_common_release(&fib6_nh->nh_common);
3657 }
3658 
fib6_nh_release_dsts(struct fib6_nh * fib6_nh)3659 void fib6_nh_release_dsts(struct fib6_nh *fib6_nh)
3660 {
3661 	int cpu;
3662 
3663 	if (!fib6_nh->rt6i_pcpu)
3664 		return;
3665 
3666 	for_each_possible_cpu(cpu) {
3667 		struct rt6_info *pcpu_rt, **ppcpu_rt;
3668 
3669 		ppcpu_rt = per_cpu_ptr(fib6_nh->rt6i_pcpu, cpu);
3670 		pcpu_rt = xchg(ppcpu_rt, NULL);
3671 		if (pcpu_rt) {
3672 			dst_dev_put(&pcpu_rt->dst);
3673 			dst_release(&pcpu_rt->dst);
3674 		}
3675 	}
3676 }
3677 
ip6_route_info_create(struct fib6_config * cfg,gfp_t gfp_flags,struct netlink_ext_ack * extack)3678 static struct fib6_info *ip6_route_info_create(struct fib6_config *cfg,
3679 					      gfp_t gfp_flags,
3680 					      struct netlink_ext_ack *extack)
3681 {
3682 	struct net *net = cfg->fc_nlinfo.nl_net;
3683 	struct fib6_info *rt = NULL;
3684 	struct nexthop *nh = NULL;
3685 	struct fib6_table *table;
3686 	struct fib6_nh *fib6_nh;
3687 	int err = -EINVAL;
3688 	int addr_type;
3689 
3690 	/* RTF_PCPU is an internal flag; can not be set by userspace */
3691 	if (cfg->fc_flags & RTF_PCPU) {
3692 		NL_SET_ERR_MSG(extack, "Userspace can not set RTF_PCPU");
3693 		goto out;
3694 	}
3695 
3696 	/* RTF_CACHE is an internal flag; can not be set by userspace */
3697 	if (cfg->fc_flags & RTF_CACHE) {
3698 		NL_SET_ERR_MSG(extack, "Userspace can not set RTF_CACHE");
3699 		goto out;
3700 	}
3701 
3702 	if (cfg->fc_type > RTN_MAX) {
3703 		NL_SET_ERR_MSG(extack, "Invalid route type");
3704 		goto out;
3705 	}
3706 
3707 	if (cfg->fc_dst_len > 128) {
3708 		NL_SET_ERR_MSG(extack, "Invalid prefix length");
3709 		goto out;
3710 	}
3711 	if (cfg->fc_src_len > 128) {
3712 		NL_SET_ERR_MSG(extack, "Invalid source address length");
3713 		goto out;
3714 	}
3715 #ifndef CONFIG_IPV6_SUBTREES
3716 	if (cfg->fc_src_len) {
3717 		NL_SET_ERR_MSG(extack,
3718 			       "Specifying source address requires IPV6_SUBTREES to be enabled");
3719 		goto out;
3720 	}
3721 #endif
3722 	if (cfg->fc_nh_id) {
3723 		nh = nexthop_find_by_id(net, cfg->fc_nh_id);
3724 		if (!nh) {
3725 			NL_SET_ERR_MSG(extack, "Nexthop id does not exist");
3726 			goto out;
3727 		}
3728 		err = fib6_check_nexthop(nh, cfg, extack);
3729 		if (err)
3730 			goto out;
3731 	}
3732 
3733 	err = -ENOBUFS;
3734 	if (cfg->fc_nlinfo.nlh &&
3735 	    !(cfg->fc_nlinfo.nlh->nlmsg_flags & NLM_F_CREATE)) {
3736 		table = fib6_get_table(net, cfg->fc_table);
3737 		if (!table) {
3738 			pr_warn("NLM_F_CREATE should be specified when creating new route\n");
3739 			table = fib6_new_table(net, cfg->fc_table);
3740 		}
3741 	} else {
3742 		table = fib6_new_table(net, cfg->fc_table);
3743 	}
3744 
3745 	if (!table)
3746 		goto out;
3747 
3748 	err = -ENOMEM;
3749 	rt = fib6_info_alloc(gfp_flags, !nh);
3750 	if (!rt)
3751 		goto out;
3752 
3753 	rt->fib6_metrics = ip_fib_metrics_init(net, cfg->fc_mx, cfg->fc_mx_len,
3754 					       extack);
3755 	if (IS_ERR(rt->fib6_metrics)) {
3756 		err = PTR_ERR(rt->fib6_metrics);
3757 		/* Do not leave garbage there. */
3758 		rt->fib6_metrics = (struct dst_metrics *)&dst_default_metrics;
3759 		goto out_free;
3760 	}
3761 
3762 	if (cfg->fc_flags & RTF_ADDRCONF)
3763 		rt->dst_nocount = true;
3764 
3765 	if (cfg->fc_flags & RTF_EXPIRES)
3766 		fib6_set_expires(rt, jiffies +
3767 				clock_t_to_jiffies(cfg->fc_expires));
3768 	else
3769 		fib6_clean_expires(rt);
3770 
3771 	if (cfg->fc_protocol == RTPROT_UNSPEC)
3772 		cfg->fc_protocol = RTPROT_BOOT;
3773 	rt->fib6_protocol = cfg->fc_protocol;
3774 
3775 	rt->fib6_table = table;
3776 	rt->fib6_metric = cfg->fc_metric;
3777 	rt->fib6_type = cfg->fc_type ? : RTN_UNICAST;
3778 	rt->fib6_flags = cfg->fc_flags & ~RTF_GATEWAY;
3779 
3780 	ipv6_addr_prefix(&rt->fib6_dst.addr, &cfg->fc_dst, cfg->fc_dst_len);
3781 	rt->fib6_dst.plen = cfg->fc_dst_len;
3782 
3783 #ifdef CONFIG_IPV6_SUBTREES
3784 	ipv6_addr_prefix(&rt->fib6_src.addr, &cfg->fc_src, cfg->fc_src_len);
3785 	rt->fib6_src.plen = cfg->fc_src_len;
3786 #endif
3787 	if (nh) {
3788 		if (rt->fib6_src.plen) {
3789 			NL_SET_ERR_MSG(extack, "Nexthops can not be used with source routing");
3790 			goto out_free;
3791 		}
3792 		if (!nexthop_get(nh)) {
3793 			NL_SET_ERR_MSG(extack, "Nexthop has been deleted");
3794 			goto out_free;
3795 		}
3796 		rt->nh = nh;
3797 		fib6_nh = nexthop_fib6_nh(rt->nh);
3798 	} else {
3799 		err = fib6_nh_init(net, rt->fib6_nh, cfg, gfp_flags, extack);
3800 		if (err)
3801 			goto out;
3802 
3803 		fib6_nh = rt->fib6_nh;
3804 
3805 		/* We cannot add true routes via loopback here, they would
3806 		 * result in kernel looping; promote them to reject routes
3807 		 */
3808 		addr_type = ipv6_addr_type(&cfg->fc_dst);
3809 		if (fib6_is_reject(cfg->fc_flags, rt->fib6_nh->fib_nh_dev,
3810 				   addr_type))
3811 			rt->fib6_flags = RTF_REJECT | RTF_NONEXTHOP;
3812 	}
3813 
3814 	if (!ipv6_addr_any(&cfg->fc_prefsrc)) {
3815 		struct net_device *dev = fib6_nh->fib_nh_dev;
3816 
3817 		if (!ipv6_chk_addr(net, &cfg->fc_prefsrc, dev, 0)) {
3818 			NL_SET_ERR_MSG(extack, "Invalid source address");
3819 			err = -EINVAL;
3820 			goto out;
3821 		}
3822 		rt->fib6_prefsrc.addr = cfg->fc_prefsrc;
3823 		rt->fib6_prefsrc.plen = 128;
3824 	} else
3825 		rt->fib6_prefsrc.plen = 0;
3826 
3827 	return rt;
3828 out:
3829 	fib6_info_release(rt);
3830 	return ERR_PTR(err);
3831 out_free:
3832 	ip_fib_metrics_put(rt->fib6_metrics);
3833 	kfree(rt);
3834 	return ERR_PTR(err);
3835 }
3836 
ip6_route_add(struct fib6_config * cfg,gfp_t gfp_flags,struct netlink_ext_ack * extack)3837 int ip6_route_add(struct fib6_config *cfg, gfp_t gfp_flags,
3838 		  struct netlink_ext_ack *extack)
3839 {
3840 	struct fib6_info *rt;
3841 	int err;
3842 
3843 	rt = ip6_route_info_create(cfg, gfp_flags, extack);
3844 	if (IS_ERR(rt))
3845 		return PTR_ERR(rt);
3846 
3847 	err = __ip6_ins_rt(rt, &cfg->fc_nlinfo, extack);
3848 	fib6_info_release(rt);
3849 
3850 	return err;
3851 }
3852 
__ip6_del_rt(struct fib6_info * rt,struct nl_info * info)3853 static int __ip6_del_rt(struct fib6_info *rt, struct nl_info *info)
3854 {
3855 	struct net *net = info->nl_net;
3856 	struct fib6_table *table;
3857 	int err;
3858 
3859 	if (rt == net->ipv6.fib6_null_entry) {
3860 		err = -ENOENT;
3861 		goto out;
3862 	}
3863 
3864 	table = rt->fib6_table;
3865 	spin_lock_bh(&table->tb6_lock);
3866 	err = fib6_del(rt, info);
3867 	spin_unlock_bh(&table->tb6_lock);
3868 
3869 out:
3870 	fib6_info_release(rt);
3871 	return err;
3872 }
3873 
ip6_del_rt(struct net * net,struct fib6_info * rt,bool skip_notify)3874 int ip6_del_rt(struct net *net, struct fib6_info *rt, bool skip_notify)
3875 {
3876 	struct nl_info info = {
3877 		.nl_net = net,
3878 		.skip_notify = skip_notify
3879 	};
3880 
3881 	return __ip6_del_rt(rt, &info);
3882 }
3883 
__ip6_del_rt_siblings(struct fib6_info * rt,struct fib6_config * cfg)3884 static int __ip6_del_rt_siblings(struct fib6_info *rt, struct fib6_config *cfg)
3885 {
3886 	struct nl_info *info = &cfg->fc_nlinfo;
3887 	struct net *net = info->nl_net;
3888 	struct sk_buff *skb = NULL;
3889 	struct fib6_table *table;
3890 	int err = -ENOENT;
3891 
3892 	if (rt == net->ipv6.fib6_null_entry)
3893 		goto out_put;
3894 	table = rt->fib6_table;
3895 	spin_lock_bh(&table->tb6_lock);
3896 
3897 	if (rt->fib6_nsiblings && cfg->fc_delete_all_nh) {
3898 		struct fib6_info *sibling, *next_sibling;
3899 		struct fib6_node *fn;
3900 
3901 		/* prefer to send a single notification with all hops */
3902 		skb = nlmsg_new(rt6_nlmsg_size(rt), gfp_any());
3903 		if (skb) {
3904 			u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0;
3905 
3906 			if (rt6_fill_node(net, skb, rt, NULL,
3907 					  NULL, NULL, 0, RTM_DELROUTE,
3908 					  info->portid, seq, 0) < 0) {
3909 				kfree_skb(skb);
3910 				skb = NULL;
3911 			} else
3912 				info->skip_notify = 1;
3913 		}
3914 
3915 		/* 'rt' points to the first sibling route. If it is not the
3916 		 * leaf, then we do not need to send a notification. Otherwise,
3917 		 * we need to check if the last sibling has a next route or not
3918 		 * and emit a replace or delete notification, respectively.
3919 		 */
3920 		info->skip_notify_kernel = 1;
3921 		fn = rcu_dereference_protected(rt->fib6_node,
3922 					    lockdep_is_held(&table->tb6_lock));
3923 		if (rcu_access_pointer(fn->leaf) == rt) {
3924 			struct fib6_info *last_sibling, *replace_rt;
3925 
3926 			last_sibling = list_last_entry(&rt->fib6_siblings,
3927 						       struct fib6_info,
3928 						       fib6_siblings);
3929 			replace_rt = rcu_dereference_protected(
3930 					    last_sibling->fib6_next,
3931 					    lockdep_is_held(&table->tb6_lock));
3932 			if (replace_rt)
3933 				call_fib6_entry_notifiers_replace(net,
3934 								  replace_rt);
3935 			else
3936 				call_fib6_multipath_entry_notifiers(net,
3937 						       FIB_EVENT_ENTRY_DEL,
3938 						       rt, rt->fib6_nsiblings,
3939 						       NULL);
3940 		}
3941 		list_for_each_entry_safe(sibling, next_sibling,
3942 					 &rt->fib6_siblings,
3943 					 fib6_siblings) {
3944 			err = fib6_del(sibling, info);
3945 			if (err)
3946 				goto out_unlock;
3947 		}
3948 	}
3949 
3950 	err = fib6_del(rt, info);
3951 out_unlock:
3952 	spin_unlock_bh(&table->tb6_lock);
3953 out_put:
3954 	fib6_info_release(rt);
3955 
3956 	if (skb) {
3957 		rtnl_notify(skb, net, info->portid, RTNLGRP_IPV6_ROUTE,
3958 			    info->nlh, gfp_any());
3959 	}
3960 	return err;
3961 }
3962 
__ip6_del_cached_rt(struct rt6_info * rt,struct fib6_config * cfg)3963 static int __ip6_del_cached_rt(struct rt6_info *rt, struct fib6_config *cfg)
3964 {
3965 	int rc = -ESRCH;
3966 
3967 	if (cfg->fc_ifindex && rt->dst.dev->ifindex != cfg->fc_ifindex)
3968 		goto out;
3969 
3970 	if (cfg->fc_flags & RTF_GATEWAY &&
3971 	    !ipv6_addr_equal(&cfg->fc_gateway, &rt->rt6i_gateway))
3972 		goto out;
3973 
3974 	rc = rt6_remove_exception_rt(rt);
3975 out:
3976 	return rc;
3977 }
3978 
ip6_del_cached_rt(struct fib6_config * cfg,struct fib6_info * rt,struct fib6_nh * nh)3979 static int ip6_del_cached_rt(struct fib6_config *cfg, struct fib6_info *rt,
3980 			     struct fib6_nh *nh)
3981 {
3982 	struct fib6_result res = {
3983 		.f6i = rt,
3984 		.nh = nh,
3985 	};
3986 	struct rt6_info *rt_cache;
3987 
3988 	rt_cache = rt6_find_cached_rt(&res, &cfg->fc_dst, &cfg->fc_src);
3989 	if (rt_cache)
3990 		return __ip6_del_cached_rt(rt_cache, cfg);
3991 
3992 	return 0;
3993 }
3994 
3995 struct fib6_nh_del_cached_rt_arg {
3996 	struct fib6_config *cfg;
3997 	struct fib6_info *f6i;
3998 };
3999 
fib6_nh_del_cached_rt(struct fib6_nh * nh,void * _arg)4000 static int fib6_nh_del_cached_rt(struct fib6_nh *nh, void *_arg)
4001 {
4002 	struct fib6_nh_del_cached_rt_arg *arg = _arg;
4003 	int rc;
4004 
4005 	rc = ip6_del_cached_rt(arg->cfg, arg->f6i, nh);
4006 	return rc != -ESRCH ? rc : 0;
4007 }
4008 
ip6_del_cached_rt_nh(struct fib6_config * cfg,struct fib6_info * f6i)4009 static int ip6_del_cached_rt_nh(struct fib6_config *cfg, struct fib6_info *f6i)
4010 {
4011 	struct fib6_nh_del_cached_rt_arg arg = {
4012 		.cfg = cfg,
4013 		.f6i = f6i
4014 	};
4015 
4016 	return nexthop_for_each_fib6_nh(f6i->nh, fib6_nh_del_cached_rt, &arg);
4017 }
4018 
ip6_route_del(struct fib6_config * cfg,struct netlink_ext_ack * extack)4019 static int ip6_route_del(struct fib6_config *cfg,
4020 			 struct netlink_ext_ack *extack)
4021 {
4022 	struct fib6_table *table;
4023 	struct fib6_info *rt;
4024 	struct fib6_node *fn;
4025 	int err = -ESRCH;
4026 
4027 	table = fib6_get_table(cfg->fc_nlinfo.nl_net, cfg->fc_table);
4028 	if (!table) {
4029 		NL_SET_ERR_MSG(extack, "FIB table does not exist");
4030 		return err;
4031 	}
4032 
4033 	rcu_read_lock();
4034 
4035 	fn = fib6_locate(&table->tb6_root,
4036 			 &cfg->fc_dst, cfg->fc_dst_len,
4037 			 &cfg->fc_src, cfg->fc_src_len,
4038 			 !(cfg->fc_flags & RTF_CACHE));
4039 
4040 	if (fn) {
4041 		for_each_fib6_node_rt_rcu(fn) {
4042 			struct fib6_nh *nh;
4043 
4044 			if (rt->nh && cfg->fc_nh_id &&
4045 			    rt->nh->id != cfg->fc_nh_id)
4046 				continue;
4047 
4048 			if (cfg->fc_flags & RTF_CACHE) {
4049 				int rc = 0;
4050 
4051 				if (rt->nh) {
4052 					rc = ip6_del_cached_rt_nh(cfg, rt);
4053 				} else if (cfg->fc_nh_id) {
4054 					continue;
4055 				} else {
4056 					nh = rt->fib6_nh;
4057 					rc = ip6_del_cached_rt(cfg, rt, nh);
4058 				}
4059 				if (rc != -ESRCH) {
4060 					rcu_read_unlock();
4061 					return rc;
4062 				}
4063 				continue;
4064 			}
4065 
4066 			if (cfg->fc_metric && cfg->fc_metric != rt->fib6_metric)
4067 				continue;
4068 			if (cfg->fc_protocol &&
4069 			    cfg->fc_protocol != rt->fib6_protocol)
4070 				continue;
4071 
4072 			if (rt->nh) {
4073 				if (!fib6_info_hold_safe(rt))
4074 					continue;
4075 				rcu_read_unlock();
4076 
4077 				return __ip6_del_rt(rt, &cfg->fc_nlinfo);
4078 			}
4079 			if (cfg->fc_nh_id)
4080 				continue;
4081 
4082 			nh = rt->fib6_nh;
4083 			if (cfg->fc_ifindex &&
4084 			    (!nh->fib_nh_dev ||
4085 			     nh->fib_nh_dev->ifindex != cfg->fc_ifindex))
4086 				continue;
4087 			if (cfg->fc_flags & RTF_GATEWAY &&
4088 			    !ipv6_addr_equal(&cfg->fc_gateway, &nh->fib_nh_gw6))
4089 				continue;
4090 			if (!fib6_info_hold_safe(rt))
4091 				continue;
4092 			rcu_read_unlock();
4093 
4094 			/* if gateway was specified only delete the one hop */
4095 			if (cfg->fc_flags & RTF_GATEWAY)
4096 				return __ip6_del_rt(rt, &cfg->fc_nlinfo);
4097 
4098 			return __ip6_del_rt_siblings(rt, cfg);
4099 		}
4100 	}
4101 	rcu_read_unlock();
4102 
4103 	return err;
4104 }
4105 
rt6_do_redirect(struct dst_entry * dst,struct sock * sk,struct sk_buff * skb)4106 static void rt6_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb)
4107 {
4108 	struct netevent_redirect netevent;
4109 	struct rt6_info *rt, *nrt = NULL;
4110 	struct fib6_result res = {};
4111 	struct ndisc_options ndopts;
4112 	struct inet6_dev *in6_dev;
4113 	struct neighbour *neigh;
4114 	struct rd_msg *msg;
4115 	int optlen, on_link;
4116 	u8 *lladdr;
4117 
4118 	optlen = skb_tail_pointer(skb) - skb_transport_header(skb);
4119 	optlen -= sizeof(*msg);
4120 
4121 	if (optlen < 0) {
4122 		net_dbg_ratelimited("rt6_do_redirect: packet too short\n");
4123 		return;
4124 	}
4125 
4126 	msg = (struct rd_msg *)icmp6_hdr(skb);
4127 
4128 	if (ipv6_addr_is_multicast(&msg->dest)) {
4129 		net_dbg_ratelimited("rt6_do_redirect: destination address is multicast\n");
4130 		return;
4131 	}
4132 
4133 	on_link = 0;
4134 	if (ipv6_addr_equal(&msg->dest, &msg->target)) {
4135 		on_link = 1;
4136 	} else if (ipv6_addr_type(&msg->target) !=
4137 		   (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
4138 		net_dbg_ratelimited("rt6_do_redirect: target address is not link-local unicast\n");
4139 		return;
4140 	}
4141 
4142 	in6_dev = __in6_dev_get(skb->dev);
4143 	if (!in6_dev)
4144 		return;
4145 	if (in6_dev->cnf.forwarding || !in6_dev->cnf.accept_redirects)
4146 		return;
4147 
4148 	/* RFC2461 8.1:
4149 	 *	The IP source address of the Redirect MUST be the same as the current
4150 	 *	first-hop router for the specified ICMP Destination Address.
4151 	 */
4152 
4153 	if (!ndisc_parse_options(skb->dev, msg->opt, optlen, &ndopts)) {
4154 		net_dbg_ratelimited("rt6_redirect: invalid ND options\n");
4155 		return;
4156 	}
4157 
4158 	lladdr = NULL;
4159 	if (ndopts.nd_opts_tgt_lladdr) {
4160 		lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr,
4161 					     skb->dev);
4162 		if (!lladdr) {
4163 			net_dbg_ratelimited("rt6_redirect: invalid link-layer address length\n");
4164 			return;
4165 		}
4166 	}
4167 
4168 	rt = (struct rt6_info *) dst;
4169 	if (rt->rt6i_flags & RTF_REJECT) {
4170 		net_dbg_ratelimited("rt6_redirect: source isn't a valid nexthop for redirect target\n");
4171 		return;
4172 	}
4173 
4174 	/* Redirect received -> path was valid.
4175 	 * Look, redirects are sent only in response to data packets,
4176 	 * so that this nexthop apparently is reachable. --ANK
4177 	 */
4178 	dst_confirm_neigh(&rt->dst, &ipv6_hdr(skb)->saddr);
4179 
4180 	neigh = __neigh_lookup(&nd_tbl, &msg->target, skb->dev, 1);
4181 	if (!neigh)
4182 		return;
4183 
4184 	/*
4185 	 *	We have finally decided to accept it.
4186 	 */
4187 
4188 	ndisc_update(skb->dev, neigh, lladdr, NUD_STALE,
4189 		     NEIGH_UPDATE_F_WEAK_OVERRIDE|
4190 		     NEIGH_UPDATE_F_OVERRIDE|
4191 		     (on_link ? 0 : (NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
4192 				     NEIGH_UPDATE_F_ISROUTER)),
4193 		     NDISC_REDIRECT, &ndopts);
4194 
4195 	rcu_read_lock();
4196 	res.f6i = rcu_dereference(rt->from);
4197 	if (!res.f6i)
4198 		goto out;
4199 
4200 	if (res.f6i->nh) {
4201 		struct fib6_nh_match_arg arg = {
4202 			.dev = dst->dev,
4203 			.gw = &rt->rt6i_gateway,
4204 		};
4205 
4206 		nexthop_for_each_fib6_nh(res.f6i->nh,
4207 					 fib6_nh_find_match, &arg);
4208 
4209 		/* fib6_info uses a nexthop that does not have fib6_nh
4210 		 * using the dst->dev. Should be impossible
4211 		 */
4212 		if (!arg.match)
4213 			goto out;
4214 		res.nh = arg.match;
4215 	} else {
4216 		res.nh = res.f6i->fib6_nh;
4217 	}
4218 
4219 	res.fib6_flags = res.f6i->fib6_flags;
4220 	res.fib6_type = res.f6i->fib6_type;
4221 	nrt = ip6_rt_cache_alloc(&res, &msg->dest, NULL);
4222 	if (!nrt)
4223 		goto out;
4224 
4225 	nrt->rt6i_flags = RTF_GATEWAY|RTF_UP|RTF_DYNAMIC|RTF_CACHE;
4226 	if (on_link)
4227 		nrt->rt6i_flags &= ~RTF_GATEWAY;
4228 
4229 	nrt->rt6i_gateway = *(struct in6_addr *)neigh->primary_key;
4230 
4231 	/* rt6_insert_exception() will take care of duplicated exceptions */
4232 	if (rt6_insert_exception(nrt, &res)) {
4233 		dst_release_immediate(&nrt->dst);
4234 		goto out;
4235 	}
4236 
4237 	netevent.old = &rt->dst;
4238 	netevent.new = &nrt->dst;
4239 	netevent.daddr = &msg->dest;
4240 	netevent.neigh = neigh;
4241 	call_netevent_notifiers(NETEVENT_REDIRECT, &netevent);
4242 
4243 out:
4244 	rcu_read_unlock();
4245 	neigh_release(neigh);
4246 }
4247 
4248 #ifdef CONFIG_IPV6_ROUTE_INFO
rt6_get_route_info(struct net * net,const struct in6_addr * prefix,int prefixlen,const struct in6_addr * gwaddr,struct net_device * dev)4249 static struct fib6_info *rt6_get_route_info(struct net *net,
4250 					   const struct in6_addr *prefix, int prefixlen,
4251 					   const struct in6_addr *gwaddr,
4252 					   struct net_device *dev)
4253 {
4254 	u32 tb_id = l3mdev_fib_table(dev) ? : RT6_TABLE_INFO;
4255 	int ifindex = dev->ifindex;
4256 	struct fib6_node *fn;
4257 	struct fib6_info *rt = NULL;
4258 	struct fib6_table *table;
4259 
4260 	table = fib6_get_table(net, tb_id);
4261 	if (!table)
4262 		return NULL;
4263 
4264 	rcu_read_lock();
4265 	fn = fib6_locate(&table->tb6_root, prefix, prefixlen, NULL, 0, true);
4266 	if (!fn)
4267 		goto out;
4268 
4269 	for_each_fib6_node_rt_rcu(fn) {
4270 		/* these routes do not use nexthops */
4271 		if (rt->nh)
4272 			continue;
4273 		if (rt->fib6_nh->fib_nh_dev->ifindex != ifindex)
4274 			continue;
4275 		if (!(rt->fib6_flags & RTF_ROUTEINFO) ||
4276 		    !rt->fib6_nh->fib_nh_gw_family)
4277 			continue;
4278 		if (!ipv6_addr_equal(&rt->fib6_nh->fib_nh_gw6, gwaddr))
4279 			continue;
4280 		if (!fib6_info_hold_safe(rt))
4281 			continue;
4282 		break;
4283 	}
4284 out:
4285 	rcu_read_unlock();
4286 	return rt;
4287 }
4288 
rt6_add_route_info(struct net * net,const struct in6_addr * prefix,int prefixlen,const struct in6_addr * gwaddr,struct net_device * dev,unsigned int pref)4289 static struct fib6_info *rt6_add_route_info(struct net *net,
4290 					   const struct in6_addr *prefix, int prefixlen,
4291 					   const struct in6_addr *gwaddr,
4292 					   struct net_device *dev,
4293 					   unsigned int pref)
4294 {
4295 	struct fib6_config cfg = {
4296 		.fc_metric	= IP6_RT_PRIO_USER,
4297 		.fc_ifindex	= dev->ifindex,
4298 		.fc_dst_len	= prefixlen,
4299 		.fc_flags	= RTF_GATEWAY | RTF_ADDRCONF | RTF_ROUTEINFO |
4300 				  RTF_UP | RTF_PREF(pref),
4301 		.fc_protocol = RTPROT_RA,
4302 		.fc_type = RTN_UNICAST,
4303 		.fc_nlinfo.portid = 0,
4304 		.fc_nlinfo.nlh = NULL,
4305 		.fc_nlinfo.nl_net = net,
4306 	};
4307 
4308 	cfg.fc_table = l3mdev_fib_table(dev) ? : RT6_TABLE_INFO;
4309 	cfg.fc_dst = *prefix;
4310 	cfg.fc_gateway = *gwaddr;
4311 
4312 	/* We should treat it as a default route if prefix length is 0. */
4313 	if (!prefixlen)
4314 		cfg.fc_flags |= RTF_DEFAULT;
4315 
4316 	ip6_route_add(&cfg, GFP_ATOMIC, NULL);
4317 
4318 	return rt6_get_route_info(net, prefix, prefixlen, gwaddr, dev);
4319 }
4320 #endif
4321 
rt6_get_dflt_router(struct net * net,const struct in6_addr * addr,struct net_device * dev)4322 struct fib6_info *rt6_get_dflt_router(struct net *net,
4323 				     const struct in6_addr *addr,
4324 				     struct net_device *dev)
4325 {
4326 	u32 tb_id = l3mdev_fib_table(dev) ? : RT6_TABLE_DFLT;
4327 	struct fib6_info *rt;
4328 	struct fib6_table *table;
4329 
4330 	table = fib6_get_table(net, tb_id);
4331 	if (!table)
4332 		return NULL;
4333 
4334 	rcu_read_lock();
4335 	for_each_fib6_node_rt_rcu(&table->tb6_root) {
4336 		struct fib6_nh *nh;
4337 
4338 		/* RA routes do not use nexthops */
4339 		if (rt->nh)
4340 			continue;
4341 
4342 		nh = rt->fib6_nh;
4343 		if (dev == nh->fib_nh_dev &&
4344 		    ((rt->fib6_flags & (RTF_ADDRCONF | RTF_DEFAULT)) == (RTF_ADDRCONF | RTF_DEFAULT)) &&
4345 		    ipv6_addr_equal(&nh->fib_nh_gw6, addr))
4346 			break;
4347 	}
4348 	if (rt && !fib6_info_hold_safe(rt))
4349 		rt = NULL;
4350 	rcu_read_unlock();
4351 	return rt;
4352 }
4353 
rt6_add_dflt_router(struct net * net,const struct in6_addr * gwaddr,struct net_device * dev,unsigned int pref,u32 defrtr_usr_metric)4354 struct fib6_info *rt6_add_dflt_router(struct net *net,
4355 				     const struct in6_addr *gwaddr,
4356 				     struct net_device *dev,
4357 				     unsigned int pref,
4358 				     u32 defrtr_usr_metric)
4359 {
4360 	struct fib6_config cfg = {
4361 		.fc_table	= l3mdev_fib_table(dev) ? : RT6_TABLE_DFLT,
4362 		.fc_metric	= defrtr_usr_metric,
4363 		.fc_ifindex	= dev->ifindex,
4364 		.fc_flags	= RTF_GATEWAY | RTF_ADDRCONF | RTF_DEFAULT |
4365 				  RTF_UP | RTF_EXPIRES | RTF_PREF(pref),
4366 		.fc_protocol = RTPROT_RA,
4367 		.fc_type = RTN_UNICAST,
4368 		.fc_nlinfo.portid = 0,
4369 		.fc_nlinfo.nlh = NULL,
4370 		.fc_nlinfo.nl_net = net,
4371 	};
4372 
4373 	cfg.fc_gateway = *gwaddr;
4374 
4375 	if (!ip6_route_add(&cfg, GFP_ATOMIC, NULL)) {
4376 		struct fib6_table *table;
4377 
4378 		table = fib6_get_table(dev_net(dev), cfg.fc_table);
4379 		if (table)
4380 			table->flags |= RT6_TABLE_HAS_DFLT_ROUTER;
4381 	}
4382 
4383 	return rt6_get_dflt_router(net, gwaddr, dev);
4384 }
4385 
__rt6_purge_dflt_routers(struct net * net,struct fib6_table * table)4386 static void __rt6_purge_dflt_routers(struct net *net,
4387 				     struct fib6_table *table)
4388 {
4389 	struct fib6_info *rt;
4390 
4391 restart:
4392 	rcu_read_lock();
4393 	for_each_fib6_node_rt_rcu(&table->tb6_root) {
4394 		struct net_device *dev = fib6_info_nh_dev(rt);
4395 		struct inet6_dev *idev = dev ? __in6_dev_get(dev) : NULL;
4396 
4397 		if (rt->fib6_flags & (RTF_DEFAULT | RTF_ADDRCONF) &&
4398 		    (!idev || idev->cnf.accept_ra != 2) &&
4399 		    fib6_info_hold_safe(rt)) {
4400 			rcu_read_unlock();
4401 			ip6_del_rt(net, rt, false);
4402 			goto restart;
4403 		}
4404 	}
4405 	rcu_read_unlock();
4406 
4407 	table->flags &= ~RT6_TABLE_HAS_DFLT_ROUTER;
4408 }
4409 
rt6_purge_dflt_routers(struct net * net)4410 void rt6_purge_dflt_routers(struct net *net)
4411 {
4412 	struct fib6_table *table;
4413 	struct hlist_head *head;
4414 	unsigned int h;
4415 
4416 	rcu_read_lock();
4417 
4418 	for (h = 0; h < FIB6_TABLE_HASHSZ; h++) {
4419 		head = &net->ipv6.fib_table_hash[h];
4420 		hlist_for_each_entry_rcu(table, head, tb6_hlist) {
4421 			if (table->flags & RT6_TABLE_HAS_DFLT_ROUTER)
4422 				__rt6_purge_dflt_routers(net, table);
4423 		}
4424 	}
4425 
4426 	rcu_read_unlock();
4427 }
4428 
rtmsg_to_fib6_config(struct net * net,struct in6_rtmsg * rtmsg,struct fib6_config * cfg)4429 static void rtmsg_to_fib6_config(struct net *net,
4430 				 struct in6_rtmsg *rtmsg,
4431 				 struct fib6_config *cfg)
4432 {
4433 	*cfg = (struct fib6_config){
4434 		.fc_table = l3mdev_fib_table_by_index(net, rtmsg->rtmsg_ifindex) ?
4435 			 : RT6_TABLE_MAIN,
4436 		.fc_ifindex = rtmsg->rtmsg_ifindex,
4437 		.fc_metric = rtmsg->rtmsg_metric ? : IP6_RT_PRIO_USER,
4438 		.fc_expires = rtmsg->rtmsg_info,
4439 		.fc_dst_len = rtmsg->rtmsg_dst_len,
4440 		.fc_src_len = rtmsg->rtmsg_src_len,
4441 		.fc_flags = rtmsg->rtmsg_flags,
4442 		.fc_type = rtmsg->rtmsg_type,
4443 
4444 		.fc_nlinfo.nl_net = net,
4445 
4446 		.fc_dst = rtmsg->rtmsg_dst,
4447 		.fc_src = rtmsg->rtmsg_src,
4448 		.fc_gateway = rtmsg->rtmsg_gateway,
4449 	};
4450 }
4451 
ipv6_route_ioctl(struct net * net,unsigned int cmd,struct in6_rtmsg * rtmsg)4452 int ipv6_route_ioctl(struct net *net, unsigned int cmd, struct in6_rtmsg *rtmsg)
4453 {
4454 	struct fib6_config cfg;
4455 	int err;
4456 
4457 	if (cmd != SIOCADDRT && cmd != SIOCDELRT)
4458 		return -EINVAL;
4459 	if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
4460 		return -EPERM;
4461 
4462 	rtmsg_to_fib6_config(net, rtmsg, &cfg);
4463 
4464 	rtnl_lock();
4465 	switch (cmd) {
4466 	case SIOCADDRT:
4467 		err = ip6_route_add(&cfg, GFP_KERNEL, NULL);
4468 		break;
4469 	case SIOCDELRT:
4470 		err = ip6_route_del(&cfg, NULL);
4471 		break;
4472 	}
4473 	rtnl_unlock();
4474 	return err;
4475 }
4476 
4477 /*
4478  *	Drop the packet on the floor
4479  */
4480 
ip6_pkt_drop(struct sk_buff * skb,u8 code,int ipstats_mib_noroutes)4481 static int ip6_pkt_drop(struct sk_buff *skb, u8 code, int ipstats_mib_noroutes)
4482 {
4483 	struct dst_entry *dst = skb_dst(skb);
4484 	struct net *net = dev_net(dst->dev);
4485 	struct inet6_dev *idev;
4486 	SKB_DR(reason);
4487 	int type;
4488 
4489 	if (netif_is_l3_master(skb->dev) ||
4490 	    dst->dev == net->loopback_dev)
4491 		idev = __in6_dev_get_safely(dev_get_by_index_rcu(net, IP6CB(skb)->iif));
4492 	else
4493 		idev = ip6_dst_idev(dst);
4494 
4495 	switch (ipstats_mib_noroutes) {
4496 	case IPSTATS_MIB_INNOROUTES:
4497 		type = ipv6_addr_type(&ipv6_hdr(skb)->daddr);
4498 		if (type == IPV6_ADDR_ANY) {
4499 			SKB_DR_SET(reason, IP_INADDRERRORS);
4500 			IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS);
4501 			break;
4502 		}
4503 		SKB_DR_SET(reason, IP_INNOROUTES);
4504 		fallthrough;
4505 	case IPSTATS_MIB_OUTNOROUTES:
4506 		SKB_DR_OR(reason, IP_OUTNOROUTES);
4507 		IP6_INC_STATS(net, idev, ipstats_mib_noroutes);
4508 		break;
4509 	}
4510 
4511 	/* Start over by dropping the dst for l3mdev case */
4512 	if (netif_is_l3_master(skb->dev))
4513 		skb_dst_drop(skb);
4514 
4515 	icmpv6_send(skb, ICMPV6_DEST_UNREACH, code, 0);
4516 	kfree_skb_reason(skb, reason);
4517 	return 0;
4518 }
4519 
ip6_pkt_discard(struct sk_buff * skb)4520 static int ip6_pkt_discard(struct sk_buff *skb)
4521 {
4522 	return ip6_pkt_drop(skb, ICMPV6_NOROUTE, IPSTATS_MIB_INNOROUTES);
4523 }
4524 
ip6_pkt_discard_out(struct net * net,struct sock * sk,struct sk_buff * skb)4525 static int ip6_pkt_discard_out(struct net *net, struct sock *sk, struct sk_buff *skb)
4526 {
4527 	skb->dev = skb_dst(skb)->dev;
4528 	return ip6_pkt_drop(skb, ICMPV6_NOROUTE, IPSTATS_MIB_OUTNOROUTES);
4529 }
4530 
ip6_pkt_prohibit(struct sk_buff * skb)4531 static int ip6_pkt_prohibit(struct sk_buff *skb)
4532 {
4533 	return ip6_pkt_drop(skb, ICMPV6_ADM_PROHIBITED, IPSTATS_MIB_INNOROUTES);
4534 }
4535 
ip6_pkt_prohibit_out(struct net * net,struct sock * sk,struct sk_buff * skb)4536 static int ip6_pkt_prohibit_out(struct net *net, struct sock *sk, struct sk_buff *skb)
4537 {
4538 	skb->dev = skb_dst(skb)->dev;
4539 	return ip6_pkt_drop(skb, ICMPV6_ADM_PROHIBITED, IPSTATS_MIB_OUTNOROUTES);
4540 }
4541 
4542 /*
4543  *	Allocate a dst for local (unicast / anycast) address.
4544  */
4545 
addrconf_f6i_alloc(struct net * net,struct inet6_dev * idev,const struct in6_addr * addr,bool anycast,gfp_t gfp_flags,struct netlink_ext_ack * extack)4546 struct fib6_info *addrconf_f6i_alloc(struct net *net,
4547 				     struct inet6_dev *idev,
4548 				     const struct in6_addr *addr,
4549 				     bool anycast, gfp_t gfp_flags,
4550 				     struct netlink_ext_ack *extack)
4551 {
4552 	struct fib6_config cfg = {
4553 		.fc_table = l3mdev_fib_table(idev->dev) ? : RT6_TABLE_LOCAL,
4554 		.fc_ifindex = idev->dev->ifindex,
4555 		.fc_flags = RTF_UP | RTF_NONEXTHOP,
4556 		.fc_dst = *addr,
4557 		.fc_dst_len = 128,
4558 		.fc_protocol = RTPROT_KERNEL,
4559 		.fc_nlinfo.nl_net = net,
4560 		.fc_ignore_dev_down = true,
4561 	};
4562 	struct fib6_info *f6i;
4563 
4564 	if (anycast) {
4565 		cfg.fc_type = RTN_ANYCAST;
4566 		cfg.fc_flags |= RTF_ANYCAST;
4567 	} else {
4568 		cfg.fc_type = RTN_LOCAL;
4569 		cfg.fc_flags |= RTF_LOCAL;
4570 	}
4571 
4572 	f6i = ip6_route_info_create(&cfg, gfp_flags, extack);
4573 	if (!IS_ERR(f6i)) {
4574 		f6i->dst_nocount = true;
4575 
4576 		if (!anycast &&
4577 		    (net->ipv6.devconf_all->disable_policy ||
4578 		     idev->cnf.disable_policy))
4579 			f6i->dst_nopolicy = true;
4580 	}
4581 
4582 	return f6i;
4583 }
4584 
4585 /* remove deleted ip from prefsrc entries */
4586 struct arg_dev_net_ip {
4587 	struct net *net;
4588 	struct in6_addr *addr;
4589 };
4590 
fib6_remove_prefsrc(struct fib6_info * rt,void * arg)4591 static int fib6_remove_prefsrc(struct fib6_info *rt, void *arg)
4592 {
4593 	struct net *net = ((struct arg_dev_net_ip *)arg)->net;
4594 	struct in6_addr *addr = ((struct arg_dev_net_ip *)arg)->addr;
4595 
4596 	if (!rt->nh &&
4597 	    rt != net->ipv6.fib6_null_entry &&
4598 	    ipv6_addr_equal(addr, &rt->fib6_prefsrc.addr) &&
4599 	    !ipv6_chk_addr(net, addr, rt->fib6_nh->fib_nh_dev, 0)) {
4600 		spin_lock_bh(&rt6_exception_lock);
4601 		/* remove prefsrc entry */
4602 		rt->fib6_prefsrc.plen = 0;
4603 		spin_unlock_bh(&rt6_exception_lock);
4604 	}
4605 	return 0;
4606 }
4607 
rt6_remove_prefsrc(struct inet6_ifaddr * ifp)4608 void rt6_remove_prefsrc(struct inet6_ifaddr *ifp)
4609 {
4610 	struct net *net = dev_net(ifp->idev->dev);
4611 	struct arg_dev_net_ip adni = {
4612 		.net = net,
4613 		.addr = &ifp->addr,
4614 	};
4615 	fib6_clean_all(net, fib6_remove_prefsrc, &adni);
4616 }
4617 
4618 #define RTF_RA_ROUTER		(RTF_ADDRCONF | RTF_DEFAULT)
4619 
4620 /* Remove routers and update dst entries when gateway turn into host. */
fib6_clean_tohost(struct fib6_info * rt,void * arg)4621 static int fib6_clean_tohost(struct fib6_info *rt, void *arg)
4622 {
4623 	struct in6_addr *gateway = (struct in6_addr *)arg;
4624 	struct fib6_nh *nh;
4625 
4626 	/* RA routes do not use nexthops */
4627 	if (rt->nh)
4628 		return 0;
4629 
4630 	nh = rt->fib6_nh;
4631 	if (((rt->fib6_flags & RTF_RA_ROUTER) == RTF_RA_ROUTER) &&
4632 	    nh->fib_nh_gw_family && ipv6_addr_equal(gateway, &nh->fib_nh_gw6))
4633 		return -1;
4634 
4635 	/* Further clean up cached routes in exception table.
4636 	 * This is needed because cached route may have a different
4637 	 * gateway than its 'parent' in the case of an ip redirect.
4638 	 */
4639 	fib6_nh_exceptions_clean_tohost(nh, gateway);
4640 
4641 	return 0;
4642 }
4643 
rt6_clean_tohost(struct net * net,struct in6_addr * gateway)4644 void rt6_clean_tohost(struct net *net, struct in6_addr *gateway)
4645 {
4646 	fib6_clean_all(net, fib6_clean_tohost, gateway);
4647 }
4648 
4649 struct arg_netdev_event {
4650 	const struct net_device *dev;
4651 	union {
4652 		unsigned char nh_flags;
4653 		unsigned long event;
4654 	};
4655 };
4656 
rt6_multipath_first_sibling(const struct fib6_info * rt)4657 static struct fib6_info *rt6_multipath_first_sibling(const struct fib6_info *rt)
4658 {
4659 	struct fib6_info *iter;
4660 	struct fib6_node *fn;
4661 
4662 	fn = rcu_dereference_protected(rt->fib6_node,
4663 			lockdep_is_held(&rt->fib6_table->tb6_lock));
4664 	iter = rcu_dereference_protected(fn->leaf,
4665 			lockdep_is_held(&rt->fib6_table->tb6_lock));
4666 	while (iter) {
4667 		if (iter->fib6_metric == rt->fib6_metric &&
4668 		    rt6_qualify_for_ecmp(iter))
4669 			return iter;
4670 		iter = rcu_dereference_protected(iter->fib6_next,
4671 				lockdep_is_held(&rt->fib6_table->tb6_lock));
4672 	}
4673 
4674 	return NULL;
4675 }
4676 
4677 /* only called for fib entries with builtin fib6_nh */
rt6_is_dead(const struct fib6_info * rt)4678 static bool rt6_is_dead(const struct fib6_info *rt)
4679 {
4680 	if (rt->fib6_nh->fib_nh_flags & RTNH_F_DEAD ||
4681 	    (rt->fib6_nh->fib_nh_flags & RTNH_F_LINKDOWN &&
4682 	     ip6_ignore_linkdown(rt->fib6_nh->fib_nh_dev)))
4683 		return true;
4684 
4685 	return false;
4686 }
4687 
rt6_multipath_total_weight(const struct fib6_info * rt)4688 static int rt6_multipath_total_weight(const struct fib6_info *rt)
4689 {
4690 	struct fib6_info *iter;
4691 	int total = 0;
4692 
4693 	if (!rt6_is_dead(rt))
4694 		total += rt->fib6_nh->fib_nh_weight;
4695 
4696 	list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings) {
4697 		if (!rt6_is_dead(iter))
4698 			total += iter->fib6_nh->fib_nh_weight;
4699 	}
4700 
4701 	return total;
4702 }
4703 
rt6_upper_bound_set(struct fib6_info * rt,int * weight,int total)4704 static void rt6_upper_bound_set(struct fib6_info *rt, int *weight, int total)
4705 {
4706 	int upper_bound = -1;
4707 
4708 	if (!rt6_is_dead(rt)) {
4709 		*weight += rt->fib6_nh->fib_nh_weight;
4710 		upper_bound = DIV_ROUND_CLOSEST_ULL((u64) (*weight) << 31,
4711 						    total) - 1;
4712 	}
4713 	atomic_set(&rt->fib6_nh->fib_nh_upper_bound, upper_bound);
4714 }
4715 
rt6_multipath_upper_bound_set(struct fib6_info * rt,int total)4716 static void rt6_multipath_upper_bound_set(struct fib6_info *rt, int total)
4717 {
4718 	struct fib6_info *iter;
4719 	int weight = 0;
4720 
4721 	rt6_upper_bound_set(rt, &weight, total);
4722 
4723 	list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
4724 		rt6_upper_bound_set(iter, &weight, total);
4725 }
4726 
rt6_multipath_rebalance(struct fib6_info * rt)4727 void rt6_multipath_rebalance(struct fib6_info *rt)
4728 {
4729 	struct fib6_info *first;
4730 	int total;
4731 
4732 	/* In case the entire multipath route was marked for flushing,
4733 	 * then there is no need to rebalance upon the removal of every
4734 	 * sibling route.
4735 	 */
4736 	if (!rt->fib6_nsiblings || rt->should_flush)
4737 		return;
4738 
4739 	/* During lookup routes are evaluated in order, so we need to
4740 	 * make sure upper bounds are assigned from the first sibling
4741 	 * onwards.
4742 	 */
4743 	first = rt6_multipath_first_sibling(rt);
4744 	if (WARN_ON_ONCE(!first))
4745 		return;
4746 
4747 	total = rt6_multipath_total_weight(first);
4748 	rt6_multipath_upper_bound_set(first, total);
4749 }
4750 
fib6_ifup(struct fib6_info * rt,void * p_arg)4751 static int fib6_ifup(struct fib6_info *rt, void *p_arg)
4752 {
4753 	const struct arg_netdev_event *arg = p_arg;
4754 	struct net *net = dev_net(arg->dev);
4755 
4756 	if (rt != net->ipv6.fib6_null_entry && !rt->nh &&
4757 	    rt->fib6_nh->fib_nh_dev == arg->dev) {
4758 		rt->fib6_nh->fib_nh_flags &= ~arg->nh_flags;
4759 		fib6_update_sernum_upto_root(net, rt);
4760 		rt6_multipath_rebalance(rt);
4761 	}
4762 
4763 	return 0;
4764 }
4765 
rt6_sync_up(struct net_device * dev,unsigned char nh_flags)4766 void rt6_sync_up(struct net_device *dev, unsigned char nh_flags)
4767 {
4768 	struct arg_netdev_event arg = {
4769 		.dev = dev,
4770 		{
4771 			.nh_flags = nh_flags,
4772 		},
4773 	};
4774 
4775 	if (nh_flags & RTNH_F_DEAD && netif_carrier_ok(dev))
4776 		arg.nh_flags |= RTNH_F_LINKDOWN;
4777 
4778 	fib6_clean_all(dev_net(dev), fib6_ifup, &arg);
4779 }
4780 
4781 /* only called for fib entries with inline fib6_nh */
rt6_multipath_uses_dev(const struct fib6_info * rt,const struct net_device * dev)4782 static bool rt6_multipath_uses_dev(const struct fib6_info *rt,
4783 				   const struct net_device *dev)
4784 {
4785 	struct fib6_info *iter;
4786 
4787 	if (rt->fib6_nh->fib_nh_dev == dev)
4788 		return true;
4789 	list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
4790 		if (iter->fib6_nh->fib_nh_dev == dev)
4791 			return true;
4792 
4793 	return false;
4794 }
4795 
rt6_multipath_flush(struct fib6_info * rt)4796 static void rt6_multipath_flush(struct fib6_info *rt)
4797 {
4798 	struct fib6_info *iter;
4799 
4800 	rt->should_flush = 1;
4801 	list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
4802 		iter->should_flush = 1;
4803 }
4804 
rt6_multipath_dead_count(const struct fib6_info * rt,const struct net_device * down_dev)4805 static unsigned int rt6_multipath_dead_count(const struct fib6_info *rt,
4806 					     const struct net_device *down_dev)
4807 {
4808 	struct fib6_info *iter;
4809 	unsigned int dead = 0;
4810 
4811 	if (rt->fib6_nh->fib_nh_dev == down_dev ||
4812 	    rt->fib6_nh->fib_nh_flags & RTNH_F_DEAD)
4813 		dead++;
4814 	list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
4815 		if (iter->fib6_nh->fib_nh_dev == down_dev ||
4816 		    iter->fib6_nh->fib_nh_flags & RTNH_F_DEAD)
4817 			dead++;
4818 
4819 	return dead;
4820 }
4821 
rt6_multipath_nh_flags_set(struct fib6_info * rt,const struct net_device * dev,unsigned char nh_flags)4822 static void rt6_multipath_nh_flags_set(struct fib6_info *rt,
4823 				       const struct net_device *dev,
4824 				       unsigned char nh_flags)
4825 {
4826 	struct fib6_info *iter;
4827 
4828 	if (rt->fib6_nh->fib_nh_dev == dev)
4829 		rt->fib6_nh->fib_nh_flags |= nh_flags;
4830 	list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
4831 		if (iter->fib6_nh->fib_nh_dev == dev)
4832 			iter->fib6_nh->fib_nh_flags |= nh_flags;
4833 }
4834 
4835 /* called with write lock held for table with rt */
fib6_ifdown(struct fib6_info * rt,void * p_arg)4836 static int fib6_ifdown(struct fib6_info *rt, void *p_arg)
4837 {
4838 	const struct arg_netdev_event *arg = p_arg;
4839 	const struct net_device *dev = arg->dev;
4840 	struct net *net = dev_net(dev);
4841 
4842 	if (rt == net->ipv6.fib6_null_entry || rt->nh)
4843 		return 0;
4844 
4845 	switch (arg->event) {
4846 	case NETDEV_UNREGISTER:
4847 		return rt->fib6_nh->fib_nh_dev == dev ? -1 : 0;
4848 	case NETDEV_DOWN:
4849 		if (rt->should_flush)
4850 			return -1;
4851 		if (!rt->fib6_nsiblings)
4852 			return rt->fib6_nh->fib_nh_dev == dev ? -1 : 0;
4853 		if (rt6_multipath_uses_dev(rt, dev)) {
4854 			unsigned int count;
4855 
4856 			count = rt6_multipath_dead_count(rt, dev);
4857 			if (rt->fib6_nsiblings + 1 == count) {
4858 				rt6_multipath_flush(rt);
4859 				return -1;
4860 			}
4861 			rt6_multipath_nh_flags_set(rt, dev, RTNH_F_DEAD |
4862 						   RTNH_F_LINKDOWN);
4863 			fib6_update_sernum(net, rt);
4864 			rt6_multipath_rebalance(rt);
4865 		}
4866 		return -2;
4867 	case NETDEV_CHANGE:
4868 		if (rt->fib6_nh->fib_nh_dev != dev ||
4869 		    rt->fib6_flags & (RTF_LOCAL | RTF_ANYCAST))
4870 			break;
4871 		rt->fib6_nh->fib_nh_flags |= RTNH_F_LINKDOWN;
4872 		rt6_multipath_rebalance(rt);
4873 		break;
4874 	}
4875 
4876 	return 0;
4877 }
4878 
rt6_sync_down_dev(struct net_device * dev,unsigned long event)4879 void rt6_sync_down_dev(struct net_device *dev, unsigned long event)
4880 {
4881 	struct arg_netdev_event arg = {
4882 		.dev = dev,
4883 		{
4884 			.event = event,
4885 		},
4886 	};
4887 	struct net *net = dev_net(dev);
4888 
4889 	if (net->ipv6.sysctl.skip_notify_on_dev_down)
4890 		fib6_clean_all_skip_notify(net, fib6_ifdown, &arg);
4891 	else
4892 		fib6_clean_all(net, fib6_ifdown, &arg);
4893 }
4894 
rt6_disable_ip(struct net_device * dev,unsigned long event)4895 void rt6_disable_ip(struct net_device *dev, unsigned long event)
4896 {
4897 	rt6_sync_down_dev(dev, event);
4898 	rt6_uncached_list_flush_dev(dev);
4899 	neigh_ifdown(&nd_tbl, dev);
4900 }
4901 
4902 struct rt6_mtu_change_arg {
4903 	struct net_device *dev;
4904 	unsigned int mtu;
4905 	struct fib6_info *f6i;
4906 };
4907 
fib6_nh_mtu_change(struct fib6_nh * nh,void * _arg)4908 static int fib6_nh_mtu_change(struct fib6_nh *nh, void *_arg)
4909 {
4910 	struct rt6_mtu_change_arg *arg = (struct rt6_mtu_change_arg *)_arg;
4911 	struct fib6_info *f6i = arg->f6i;
4912 
4913 	/* For administrative MTU increase, there is no way to discover
4914 	 * IPv6 PMTU increase, so PMTU increase should be updated here.
4915 	 * Since RFC 1981 doesn't include administrative MTU increase
4916 	 * update PMTU increase is a MUST. (i.e. jumbo frame)
4917 	 */
4918 	if (nh->fib_nh_dev == arg->dev) {
4919 		struct inet6_dev *idev = __in6_dev_get(arg->dev);
4920 		u32 mtu = f6i->fib6_pmtu;
4921 
4922 		if (mtu >= arg->mtu ||
4923 		    (mtu < arg->mtu && mtu == idev->cnf.mtu6))
4924 			fib6_metric_set(f6i, RTAX_MTU, arg->mtu);
4925 
4926 		spin_lock_bh(&rt6_exception_lock);
4927 		rt6_exceptions_update_pmtu(idev, nh, arg->mtu);
4928 		spin_unlock_bh(&rt6_exception_lock);
4929 	}
4930 
4931 	return 0;
4932 }
4933 
rt6_mtu_change_route(struct fib6_info * f6i,void * p_arg)4934 static int rt6_mtu_change_route(struct fib6_info *f6i, void *p_arg)
4935 {
4936 	struct rt6_mtu_change_arg *arg = (struct rt6_mtu_change_arg *) p_arg;
4937 	struct inet6_dev *idev;
4938 
4939 	/* In IPv6 pmtu discovery is not optional,
4940 	   so that RTAX_MTU lock cannot disable it.
4941 	   We still use this lock to block changes
4942 	   caused by addrconf/ndisc.
4943 	*/
4944 
4945 	idev = __in6_dev_get(arg->dev);
4946 	if (!idev)
4947 		return 0;
4948 
4949 	if (fib6_metric_locked(f6i, RTAX_MTU))
4950 		return 0;
4951 
4952 	arg->f6i = f6i;
4953 	if (f6i->nh) {
4954 		/* fib6_nh_mtu_change only returns 0, so this is safe */
4955 		return nexthop_for_each_fib6_nh(f6i->nh, fib6_nh_mtu_change,
4956 						arg);
4957 	}
4958 
4959 	return fib6_nh_mtu_change(f6i->fib6_nh, arg);
4960 }
4961 
rt6_mtu_change(struct net_device * dev,unsigned int mtu)4962 void rt6_mtu_change(struct net_device *dev, unsigned int mtu)
4963 {
4964 	struct rt6_mtu_change_arg arg = {
4965 		.dev = dev,
4966 		.mtu = mtu,
4967 	};
4968 
4969 	fib6_clean_all(dev_net(dev), rt6_mtu_change_route, &arg);
4970 }
4971 
4972 static const struct nla_policy rtm_ipv6_policy[RTA_MAX+1] = {
4973 	[RTA_UNSPEC]		= { .strict_start_type = RTA_DPORT + 1 },
4974 	[RTA_GATEWAY]           = { .len = sizeof(struct in6_addr) },
4975 	[RTA_PREFSRC]		= { .len = sizeof(struct in6_addr) },
4976 	[RTA_OIF]               = { .type = NLA_U32 },
4977 	[RTA_IIF]		= { .type = NLA_U32 },
4978 	[RTA_PRIORITY]          = { .type = NLA_U32 },
4979 	[RTA_METRICS]           = { .type = NLA_NESTED },
4980 	[RTA_MULTIPATH]		= { .len = sizeof(struct rtnexthop) },
4981 	[RTA_PREF]              = { .type = NLA_U8 },
4982 	[RTA_ENCAP_TYPE]	= { .type = NLA_U16 },
4983 	[RTA_ENCAP]		= { .type = NLA_NESTED },
4984 	[RTA_EXPIRES]		= { .type = NLA_U32 },
4985 	[RTA_UID]		= { .type = NLA_U32 },
4986 	[RTA_MARK]		= { .type = NLA_U32 },
4987 	[RTA_TABLE]		= { .type = NLA_U32 },
4988 	[RTA_IP_PROTO]		= { .type = NLA_U8 },
4989 	[RTA_SPORT]		= { .type = NLA_U16 },
4990 	[RTA_DPORT]		= { .type = NLA_U16 },
4991 	[RTA_NH_ID]		= { .type = NLA_U32 },
4992 };
4993 
rtm_to_fib6_config(struct sk_buff * skb,struct nlmsghdr * nlh,struct fib6_config * cfg,struct netlink_ext_ack * extack)4994 static int rtm_to_fib6_config(struct sk_buff *skb, struct nlmsghdr *nlh,
4995 			      struct fib6_config *cfg,
4996 			      struct netlink_ext_ack *extack)
4997 {
4998 	struct rtmsg *rtm;
4999 	struct nlattr *tb[RTA_MAX+1];
5000 	unsigned int pref;
5001 	int err;
5002 
5003 	err = nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX,
5004 				     rtm_ipv6_policy, extack);
5005 	if (err < 0)
5006 		goto errout;
5007 
5008 	err = -EINVAL;
5009 	rtm = nlmsg_data(nlh);
5010 
5011 	if (rtm->rtm_tos) {
5012 		NL_SET_ERR_MSG(extack,
5013 			       "Invalid dsfield (tos): option not available for IPv6");
5014 		goto errout;
5015 	}
5016 
5017 	*cfg = (struct fib6_config){
5018 		.fc_table = rtm->rtm_table,
5019 		.fc_dst_len = rtm->rtm_dst_len,
5020 		.fc_src_len = rtm->rtm_src_len,
5021 		.fc_flags = RTF_UP,
5022 		.fc_protocol = rtm->rtm_protocol,
5023 		.fc_type = rtm->rtm_type,
5024 
5025 		.fc_nlinfo.portid = NETLINK_CB(skb).portid,
5026 		.fc_nlinfo.nlh = nlh,
5027 		.fc_nlinfo.nl_net = sock_net(skb->sk),
5028 	};
5029 
5030 	if (rtm->rtm_type == RTN_UNREACHABLE ||
5031 	    rtm->rtm_type == RTN_BLACKHOLE ||
5032 	    rtm->rtm_type == RTN_PROHIBIT ||
5033 	    rtm->rtm_type == RTN_THROW)
5034 		cfg->fc_flags |= RTF_REJECT;
5035 
5036 	if (rtm->rtm_type == RTN_LOCAL)
5037 		cfg->fc_flags |= RTF_LOCAL;
5038 
5039 	if (rtm->rtm_flags & RTM_F_CLONED)
5040 		cfg->fc_flags |= RTF_CACHE;
5041 
5042 	cfg->fc_flags |= (rtm->rtm_flags & RTNH_F_ONLINK);
5043 
5044 	if (tb[RTA_NH_ID]) {
5045 		if (tb[RTA_GATEWAY]   || tb[RTA_OIF] ||
5046 		    tb[RTA_MULTIPATH] || tb[RTA_ENCAP]) {
5047 			NL_SET_ERR_MSG(extack,
5048 				       "Nexthop specification and nexthop id are mutually exclusive");
5049 			goto errout;
5050 		}
5051 		cfg->fc_nh_id = nla_get_u32(tb[RTA_NH_ID]);
5052 	}
5053 
5054 	if (tb[RTA_GATEWAY]) {
5055 		cfg->fc_gateway = nla_get_in6_addr(tb[RTA_GATEWAY]);
5056 		cfg->fc_flags |= RTF_GATEWAY;
5057 	}
5058 	if (tb[RTA_VIA]) {
5059 		NL_SET_ERR_MSG(extack, "IPv6 does not support RTA_VIA attribute");
5060 		goto errout;
5061 	}
5062 
5063 	if (tb[RTA_DST]) {
5064 		int plen = (rtm->rtm_dst_len + 7) >> 3;
5065 
5066 		if (nla_len(tb[RTA_DST]) < plen)
5067 			goto errout;
5068 
5069 		nla_memcpy(&cfg->fc_dst, tb[RTA_DST], plen);
5070 	}
5071 
5072 	if (tb[RTA_SRC]) {
5073 		int plen = (rtm->rtm_src_len + 7) >> 3;
5074 
5075 		if (nla_len(tb[RTA_SRC]) < plen)
5076 			goto errout;
5077 
5078 		nla_memcpy(&cfg->fc_src, tb[RTA_SRC], plen);
5079 	}
5080 
5081 	if (tb[RTA_PREFSRC])
5082 		cfg->fc_prefsrc = nla_get_in6_addr(tb[RTA_PREFSRC]);
5083 
5084 	if (tb[RTA_OIF])
5085 		cfg->fc_ifindex = nla_get_u32(tb[RTA_OIF]);
5086 
5087 	if (tb[RTA_PRIORITY])
5088 		cfg->fc_metric = nla_get_u32(tb[RTA_PRIORITY]);
5089 
5090 	if (tb[RTA_METRICS]) {
5091 		cfg->fc_mx = nla_data(tb[RTA_METRICS]);
5092 		cfg->fc_mx_len = nla_len(tb[RTA_METRICS]);
5093 	}
5094 
5095 	if (tb[RTA_TABLE])
5096 		cfg->fc_table = nla_get_u32(tb[RTA_TABLE]);
5097 
5098 	if (tb[RTA_MULTIPATH]) {
5099 		cfg->fc_mp = nla_data(tb[RTA_MULTIPATH]);
5100 		cfg->fc_mp_len = nla_len(tb[RTA_MULTIPATH]);
5101 
5102 		err = lwtunnel_valid_encap_type_attr(cfg->fc_mp,
5103 						     cfg->fc_mp_len, extack);
5104 		if (err < 0)
5105 			goto errout;
5106 	}
5107 
5108 	if (tb[RTA_PREF]) {
5109 		pref = nla_get_u8(tb[RTA_PREF]);
5110 		if (pref != ICMPV6_ROUTER_PREF_LOW &&
5111 		    pref != ICMPV6_ROUTER_PREF_HIGH)
5112 			pref = ICMPV6_ROUTER_PREF_MEDIUM;
5113 		cfg->fc_flags |= RTF_PREF(pref);
5114 	}
5115 
5116 	if (tb[RTA_ENCAP])
5117 		cfg->fc_encap = tb[RTA_ENCAP];
5118 
5119 	if (tb[RTA_ENCAP_TYPE]) {
5120 		cfg->fc_encap_type = nla_get_u16(tb[RTA_ENCAP_TYPE]);
5121 
5122 		err = lwtunnel_valid_encap_type(cfg->fc_encap_type, extack);
5123 		if (err < 0)
5124 			goto errout;
5125 	}
5126 
5127 	if (tb[RTA_EXPIRES]) {
5128 		unsigned long timeout = addrconf_timeout_fixup(nla_get_u32(tb[RTA_EXPIRES]), HZ);
5129 
5130 		if (addrconf_finite_timeout(timeout)) {
5131 			cfg->fc_expires = jiffies_to_clock_t(timeout * HZ);
5132 			cfg->fc_flags |= RTF_EXPIRES;
5133 		}
5134 	}
5135 
5136 	err = 0;
5137 errout:
5138 	return err;
5139 }
5140 
5141 struct rt6_nh {
5142 	struct fib6_info *fib6_info;
5143 	struct fib6_config r_cfg;
5144 	struct list_head next;
5145 };
5146 
ip6_route_info_append(struct net * net,struct list_head * rt6_nh_list,struct fib6_info * rt,struct fib6_config * r_cfg)5147 static int ip6_route_info_append(struct net *net,
5148 				 struct list_head *rt6_nh_list,
5149 				 struct fib6_info *rt,
5150 				 struct fib6_config *r_cfg)
5151 {
5152 	struct rt6_nh *nh;
5153 	int err = -EEXIST;
5154 
5155 	list_for_each_entry(nh, rt6_nh_list, next) {
5156 		/* check if fib6_info already exists */
5157 		if (rt6_duplicate_nexthop(nh->fib6_info, rt))
5158 			return err;
5159 	}
5160 
5161 	nh = kzalloc(sizeof(*nh), GFP_KERNEL);
5162 	if (!nh)
5163 		return -ENOMEM;
5164 	nh->fib6_info = rt;
5165 	memcpy(&nh->r_cfg, r_cfg, sizeof(*r_cfg));
5166 	list_add_tail(&nh->next, rt6_nh_list);
5167 
5168 	return 0;
5169 }
5170 
ip6_route_mpath_notify(struct fib6_info * rt,struct fib6_info * rt_last,struct nl_info * info,__u16 nlflags)5171 static void ip6_route_mpath_notify(struct fib6_info *rt,
5172 				   struct fib6_info *rt_last,
5173 				   struct nl_info *info,
5174 				   __u16 nlflags)
5175 {
5176 	/* if this is an APPEND route, then rt points to the first route
5177 	 * inserted and rt_last points to last route inserted. Userspace
5178 	 * wants a consistent dump of the route which starts at the first
5179 	 * nexthop. Since sibling routes are always added at the end of
5180 	 * the list, find the first sibling of the last route appended
5181 	 */
5182 	if ((nlflags & NLM_F_APPEND) && rt_last && rt_last->fib6_nsiblings) {
5183 		rt = list_first_entry(&rt_last->fib6_siblings,
5184 				      struct fib6_info,
5185 				      fib6_siblings);
5186 	}
5187 
5188 	if (rt)
5189 		inet6_rt_notify(RTM_NEWROUTE, rt, info, nlflags);
5190 }
5191 
ip6_route_mpath_should_notify(const struct fib6_info * rt)5192 static bool ip6_route_mpath_should_notify(const struct fib6_info *rt)
5193 {
5194 	bool rt_can_ecmp = rt6_qualify_for_ecmp(rt);
5195 	bool should_notify = false;
5196 	struct fib6_info *leaf;
5197 	struct fib6_node *fn;
5198 
5199 	rcu_read_lock();
5200 	fn = rcu_dereference(rt->fib6_node);
5201 	if (!fn)
5202 		goto out;
5203 
5204 	leaf = rcu_dereference(fn->leaf);
5205 	if (!leaf)
5206 		goto out;
5207 
5208 	if (rt == leaf ||
5209 	    (rt_can_ecmp && rt->fib6_metric == leaf->fib6_metric &&
5210 	     rt6_qualify_for_ecmp(leaf)))
5211 		should_notify = true;
5212 out:
5213 	rcu_read_unlock();
5214 
5215 	return should_notify;
5216 }
5217 
fib6_gw_from_attr(struct in6_addr * gw,struct nlattr * nla,struct netlink_ext_ack * extack)5218 static int fib6_gw_from_attr(struct in6_addr *gw, struct nlattr *nla,
5219 			     struct netlink_ext_ack *extack)
5220 {
5221 	if (nla_len(nla) < sizeof(*gw)) {
5222 		NL_SET_ERR_MSG(extack, "Invalid IPv6 address in RTA_GATEWAY");
5223 		return -EINVAL;
5224 	}
5225 
5226 	*gw = nla_get_in6_addr(nla);
5227 
5228 	return 0;
5229 }
5230 
ip6_route_multipath_add(struct fib6_config * cfg,struct netlink_ext_ack * extack)5231 static int ip6_route_multipath_add(struct fib6_config *cfg,
5232 				   struct netlink_ext_ack *extack)
5233 {
5234 	struct fib6_info *rt_notif = NULL, *rt_last = NULL;
5235 	struct nl_info *info = &cfg->fc_nlinfo;
5236 	struct fib6_config r_cfg;
5237 	struct rtnexthop *rtnh;
5238 	struct fib6_info *rt;
5239 	struct rt6_nh *err_nh;
5240 	struct rt6_nh *nh, *nh_safe;
5241 	__u16 nlflags;
5242 	int remaining;
5243 	int attrlen;
5244 	int err = 1;
5245 	int nhn = 0;
5246 	int replace = (cfg->fc_nlinfo.nlh &&
5247 		       (cfg->fc_nlinfo.nlh->nlmsg_flags & NLM_F_REPLACE));
5248 	LIST_HEAD(rt6_nh_list);
5249 
5250 	nlflags = replace ? NLM_F_REPLACE : NLM_F_CREATE;
5251 	if (info->nlh && info->nlh->nlmsg_flags & NLM_F_APPEND)
5252 		nlflags |= NLM_F_APPEND;
5253 
5254 	remaining = cfg->fc_mp_len;
5255 	rtnh = (struct rtnexthop *)cfg->fc_mp;
5256 
5257 	/* Parse a Multipath Entry and build a list (rt6_nh_list) of
5258 	 * fib6_info structs per nexthop
5259 	 */
5260 	while (rtnh_ok(rtnh, remaining)) {
5261 		memcpy(&r_cfg, cfg, sizeof(*cfg));
5262 		if (rtnh->rtnh_ifindex)
5263 			r_cfg.fc_ifindex = rtnh->rtnh_ifindex;
5264 
5265 		attrlen = rtnh_attrlen(rtnh);
5266 		if (attrlen > 0) {
5267 			struct nlattr *nla, *attrs = rtnh_attrs(rtnh);
5268 
5269 			nla = nla_find(attrs, attrlen, RTA_GATEWAY);
5270 			if (nla) {
5271 				err = fib6_gw_from_attr(&r_cfg.fc_gateway, nla,
5272 							extack);
5273 				if (err)
5274 					goto cleanup;
5275 
5276 				r_cfg.fc_flags |= RTF_GATEWAY;
5277 			}
5278 			r_cfg.fc_encap = nla_find(attrs, attrlen, RTA_ENCAP);
5279 
5280 			/* RTA_ENCAP_TYPE length checked in
5281 			 * lwtunnel_valid_encap_type_attr
5282 			 */
5283 			nla = nla_find(attrs, attrlen, RTA_ENCAP_TYPE);
5284 			if (nla)
5285 				r_cfg.fc_encap_type = nla_get_u16(nla);
5286 		}
5287 
5288 		r_cfg.fc_flags |= (rtnh->rtnh_flags & RTNH_F_ONLINK);
5289 		rt = ip6_route_info_create(&r_cfg, GFP_KERNEL, extack);
5290 		if (IS_ERR(rt)) {
5291 			err = PTR_ERR(rt);
5292 			rt = NULL;
5293 			goto cleanup;
5294 		}
5295 		if (!rt6_qualify_for_ecmp(rt)) {
5296 			err = -EINVAL;
5297 			NL_SET_ERR_MSG(extack,
5298 				       "Device only routes can not be added for IPv6 using the multipath API.");
5299 			fib6_info_release(rt);
5300 			goto cleanup;
5301 		}
5302 
5303 		rt->fib6_nh->fib_nh_weight = rtnh->rtnh_hops + 1;
5304 
5305 		err = ip6_route_info_append(info->nl_net, &rt6_nh_list,
5306 					    rt, &r_cfg);
5307 		if (err) {
5308 			fib6_info_release(rt);
5309 			goto cleanup;
5310 		}
5311 
5312 		rtnh = rtnh_next(rtnh, &remaining);
5313 	}
5314 
5315 	if (list_empty(&rt6_nh_list)) {
5316 		NL_SET_ERR_MSG(extack,
5317 			       "Invalid nexthop configuration - no valid nexthops");
5318 		return -EINVAL;
5319 	}
5320 
5321 	/* for add and replace send one notification with all nexthops.
5322 	 * Skip the notification in fib6_add_rt2node and send one with
5323 	 * the full route when done
5324 	 */
5325 	info->skip_notify = 1;
5326 
5327 	/* For add and replace, send one notification with all nexthops. For
5328 	 * append, send one notification with all appended nexthops.
5329 	 */
5330 	info->skip_notify_kernel = 1;
5331 
5332 	err_nh = NULL;
5333 	list_for_each_entry(nh, &rt6_nh_list, next) {
5334 		err = __ip6_ins_rt(nh->fib6_info, info, extack);
5335 		fib6_info_release(nh->fib6_info);
5336 
5337 		if (!err) {
5338 			/* save reference to last route successfully inserted */
5339 			rt_last = nh->fib6_info;
5340 
5341 			/* save reference to first route for notification */
5342 			if (!rt_notif)
5343 				rt_notif = nh->fib6_info;
5344 		}
5345 
5346 		/* nh->fib6_info is used or freed at this point, reset to NULL*/
5347 		nh->fib6_info = NULL;
5348 		if (err) {
5349 			if (replace && nhn)
5350 				NL_SET_ERR_MSG_MOD(extack,
5351 						   "multipath route replace failed (check consistency of installed routes)");
5352 			err_nh = nh;
5353 			goto add_errout;
5354 		}
5355 
5356 		/* Because each route is added like a single route we remove
5357 		 * these flags after the first nexthop: if there is a collision,
5358 		 * we have already failed to add the first nexthop:
5359 		 * fib6_add_rt2node() has rejected it; when replacing, old
5360 		 * nexthops have been replaced by first new, the rest should
5361 		 * be added to it.
5362 		 */
5363 		if (cfg->fc_nlinfo.nlh) {
5364 			cfg->fc_nlinfo.nlh->nlmsg_flags &= ~(NLM_F_EXCL |
5365 							     NLM_F_REPLACE);
5366 			cfg->fc_nlinfo.nlh->nlmsg_flags |= NLM_F_CREATE;
5367 		}
5368 		nhn++;
5369 	}
5370 
5371 	/* An in-kernel notification should only be sent in case the new
5372 	 * multipath route is added as the first route in the node, or if
5373 	 * it was appended to it. We pass 'rt_notif' since it is the first
5374 	 * sibling and might allow us to skip some checks in the replace case.
5375 	 */
5376 	if (ip6_route_mpath_should_notify(rt_notif)) {
5377 		enum fib_event_type fib_event;
5378 
5379 		if (rt_notif->fib6_nsiblings != nhn - 1)
5380 			fib_event = FIB_EVENT_ENTRY_APPEND;
5381 		else
5382 			fib_event = FIB_EVENT_ENTRY_REPLACE;
5383 
5384 		err = call_fib6_multipath_entry_notifiers(info->nl_net,
5385 							  fib_event, rt_notif,
5386 							  nhn - 1, extack);
5387 		if (err) {
5388 			/* Delete all the siblings that were just added */
5389 			err_nh = NULL;
5390 			goto add_errout;
5391 		}
5392 	}
5393 
5394 	/* success ... tell user about new route */
5395 	ip6_route_mpath_notify(rt_notif, rt_last, info, nlflags);
5396 	goto cleanup;
5397 
5398 add_errout:
5399 	/* send notification for routes that were added so that
5400 	 * the delete notifications sent by ip6_route_del are
5401 	 * coherent
5402 	 */
5403 	if (rt_notif)
5404 		ip6_route_mpath_notify(rt_notif, rt_last, info, nlflags);
5405 
5406 	/* Delete routes that were already added */
5407 	list_for_each_entry(nh, &rt6_nh_list, next) {
5408 		if (err_nh == nh)
5409 			break;
5410 		ip6_route_del(&nh->r_cfg, extack);
5411 	}
5412 
5413 cleanup:
5414 	list_for_each_entry_safe(nh, nh_safe, &rt6_nh_list, next) {
5415 		if (nh->fib6_info)
5416 			fib6_info_release(nh->fib6_info);
5417 		list_del(&nh->next);
5418 		kfree(nh);
5419 	}
5420 
5421 	return err;
5422 }
5423 
ip6_route_multipath_del(struct fib6_config * cfg,struct netlink_ext_ack * extack)5424 static int ip6_route_multipath_del(struct fib6_config *cfg,
5425 				   struct netlink_ext_ack *extack)
5426 {
5427 	struct fib6_config r_cfg;
5428 	struct rtnexthop *rtnh;
5429 	int last_err = 0;
5430 	int remaining;
5431 	int attrlen;
5432 	int err;
5433 
5434 	remaining = cfg->fc_mp_len;
5435 	rtnh = (struct rtnexthop *)cfg->fc_mp;
5436 
5437 	/* Parse a Multipath Entry */
5438 	while (rtnh_ok(rtnh, remaining)) {
5439 		memcpy(&r_cfg, cfg, sizeof(*cfg));
5440 		if (rtnh->rtnh_ifindex)
5441 			r_cfg.fc_ifindex = rtnh->rtnh_ifindex;
5442 
5443 		attrlen = rtnh_attrlen(rtnh);
5444 		if (attrlen > 0) {
5445 			struct nlattr *nla, *attrs = rtnh_attrs(rtnh);
5446 
5447 			nla = nla_find(attrs, attrlen, RTA_GATEWAY);
5448 			if (nla) {
5449 				err = fib6_gw_from_attr(&r_cfg.fc_gateway, nla,
5450 							extack);
5451 				if (err) {
5452 					last_err = err;
5453 					goto next_rtnh;
5454 				}
5455 
5456 				r_cfg.fc_flags |= RTF_GATEWAY;
5457 			}
5458 		}
5459 		err = ip6_route_del(&r_cfg, extack);
5460 		if (err)
5461 			last_err = err;
5462 
5463 next_rtnh:
5464 		rtnh = rtnh_next(rtnh, &remaining);
5465 	}
5466 
5467 	return last_err;
5468 }
5469 
inet6_rtm_delroute(struct sk_buff * skb,struct nlmsghdr * nlh,struct netlink_ext_ack * extack)5470 static int inet6_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh,
5471 			      struct netlink_ext_ack *extack)
5472 {
5473 	struct fib6_config cfg;
5474 	int err;
5475 
5476 	err = rtm_to_fib6_config(skb, nlh, &cfg, extack);
5477 	if (err < 0)
5478 		return err;
5479 
5480 	if (cfg.fc_nh_id &&
5481 	    !nexthop_find_by_id(sock_net(skb->sk), cfg.fc_nh_id)) {
5482 		NL_SET_ERR_MSG(extack, "Nexthop id does not exist");
5483 		return -EINVAL;
5484 	}
5485 
5486 	if (cfg.fc_mp)
5487 		return ip6_route_multipath_del(&cfg, extack);
5488 	else {
5489 		cfg.fc_delete_all_nh = 1;
5490 		return ip6_route_del(&cfg, extack);
5491 	}
5492 }
5493 
inet6_rtm_newroute(struct sk_buff * skb,struct nlmsghdr * nlh,struct netlink_ext_ack * extack)5494 static int inet6_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh,
5495 			      struct netlink_ext_ack *extack)
5496 {
5497 	struct fib6_config cfg;
5498 	int err;
5499 
5500 	err = rtm_to_fib6_config(skb, nlh, &cfg, extack);
5501 	if (err < 0)
5502 		return err;
5503 
5504 	if (cfg.fc_metric == 0)
5505 		cfg.fc_metric = IP6_RT_PRIO_USER;
5506 
5507 	if (cfg.fc_mp)
5508 		return ip6_route_multipath_add(&cfg, extack);
5509 	else
5510 		return ip6_route_add(&cfg, GFP_KERNEL, extack);
5511 }
5512 
5513 /* add the overhead of this fib6_nh to nexthop_len */
rt6_nh_nlmsg_size(struct fib6_nh * nh,void * arg)5514 static int rt6_nh_nlmsg_size(struct fib6_nh *nh, void *arg)
5515 {
5516 	int *nexthop_len = arg;
5517 
5518 	*nexthop_len += nla_total_size(0)	 /* RTA_MULTIPATH */
5519 		     + NLA_ALIGN(sizeof(struct rtnexthop))
5520 		     + nla_total_size(16); /* RTA_GATEWAY */
5521 
5522 	if (nh->fib_nh_lws) {
5523 		/* RTA_ENCAP_TYPE */
5524 		*nexthop_len += lwtunnel_get_encap_size(nh->fib_nh_lws);
5525 		/* RTA_ENCAP */
5526 		*nexthop_len += nla_total_size(2);
5527 	}
5528 
5529 	return 0;
5530 }
5531 
rt6_nlmsg_size(struct fib6_info * f6i)5532 static size_t rt6_nlmsg_size(struct fib6_info *f6i)
5533 {
5534 	int nexthop_len;
5535 
5536 	if (f6i->nh) {
5537 		nexthop_len = nla_total_size(4); /* RTA_NH_ID */
5538 		nexthop_for_each_fib6_nh(f6i->nh, rt6_nh_nlmsg_size,
5539 					 &nexthop_len);
5540 	} else {
5541 		struct fib6_info *sibling, *next_sibling;
5542 		struct fib6_nh *nh = f6i->fib6_nh;
5543 
5544 		nexthop_len = 0;
5545 		if (f6i->fib6_nsiblings) {
5546 			rt6_nh_nlmsg_size(nh, &nexthop_len);
5547 
5548 			list_for_each_entry_safe(sibling, next_sibling,
5549 						 &f6i->fib6_siblings, fib6_siblings) {
5550 				rt6_nh_nlmsg_size(sibling->fib6_nh, &nexthop_len);
5551 			}
5552 		}
5553 		nexthop_len += lwtunnel_get_encap_size(nh->fib_nh_lws);
5554 	}
5555 
5556 	return NLMSG_ALIGN(sizeof(struct rtmsg))
5557 	       + nla_total_size(16) /* RTA_SRC */
5558 	       + nla_total_size(16) /* RTA_DST */
5559 	       + nla_total_size(16) /* RTA_GATEWAY */
5560 	       + nla_total_size(16) /* RTA_PREFSRC */
5561 	       + nla_total_size(4) /* RTA_TABLE */
5562 	       + nla_total_size(4) /* RTA_IIF */
5563 	       + nla_total_size(4) /* RTA_OIF */
5564 	       + nla_total_size(4) /* RTA_PRIORITY */
5565 	       + RTAX_MAX * nla_total_size(4) /* RTA_METRICS */
5566 	       + nla_total_size(sizeof(struct rta_cacheinfo))
5567 	       + nla_total_size(TCP_CA_NAME_MAX) /* RTAX_CC_ALGO */
5568 	       + nla_total_size(1) /* RTA_PREF */
5569 	       + nexthop_len;
5570 }
5571 
rt6_fill_node_nexthop(struct sk_buff * skb,struct nexthop * nh,unsigned char * flags)5572 static int rt6_fill_node_nexthop(struct sk_buff *skb, struct nexthop *nh,
5573 				 unsigned char *flags)
5574 {
5575 	if (nexthop_is_multipath(nh)) {
5576 		struct nlattr *mp;
5577 
5578 		mp = nla_nest_start_noflag(skb, RTA_MULTIPATH);
5579 		if (!mp)
5580 			goto nla_put_failure;
5581 
5582 		if (nexthop_mpath_fill_node(skb, nh, AF_INET6))
5583 			goto nla_put_failure;
5584 
5585 		nla_nest_end(skb, mp);
5586 	} else {
5587 		struct fib6_nh *fib6_nh;
5588 
5589 		fib6_nh = nexthop_fib6_nh(nh);
5590 		if (fib_nexthop_info(skb, &fib6_nh->nh_common, AF_INET6,
5591 				     flags, false) < 0)
5592 			goto nla_put_failure;
5593 	}
5594 
5595 	return 0;
5596 
5597 nla_put_failure:
5598 	return -EMSGSIZE;
5599 }
5600 
rt6_fill_node(struct net * net,struct sk_buff * skb,struct fib6_info * rt,struct dst_entry * dst,struct in6_addr * dest,struct in6_addr * src,int iif,int type,u32 portid,u32 seq,unsigned int flags)5601 static int rt6_fill_node(struct net *net, struct sk_buff *skb,
5602 			 struct fib6_info *rt, struct dst_entry *dst,
5603 			 struct in6_addr *dest, struct in6_addr *src,
5604 			 int iif, int type, u32 portid, u32 seq,
5605 			 unsigned int flags)
5606 {
5607 	struct rt6_info *rt6 = (struct rt6_info *)dst;
5608 	struct rt6key *rt6_dst, *rt6_src;
5609 	u32 *pmetrics, table, rt6_flags;
5610 	unsigned char nh_flags = 0;
5611 	struct nlmsghdr *nlh;
5612 	struct rtmsg *rtm;
5613 	long expires = 0;
5614 
5615 	nlh = nlmsg_put(skb, portid, seq, type, sizeof(*rtm), flags);
5616 	if (!nlh)
5617 		return -EMSGSIZE;
5618 
5619 	if (rt6) {
5620 		rt6_dst = &rt6->rt6i_dst;
5621 		rt6_src = &rt6->rt6i_src;
5622 		rt6_flags = rt6->rt6i_flags;
5623 	} else {
5624 		rt6_dst = &rt->fib6_dst;
5625 		rt6_src = &rt->fib6_src;
5626 		rt6_flags = rt->fib6_flags;
5627 	}
5628 
5629 	rtm = nlmsg_data(nlh);
5630 	rtm->rtm_family = AF_INET6;
5631 	rtm->rtm_dst_len = rt6_dst->plen;
5632 	rtm->rtm_src_len = rt6_src->plen;
5633 	rtm->rtm_tos = 0;
5634 	if (rt->fib6_table)
5635 		table = rt->fib6_table->tb6_id;
5636 	else
5637 		table = RT6_TABLE_UNSPEC;
5638 	rtm->rtm_table = table < 256 ? table : RT_TABLE_COMPAT;
5639 	if (nla_put_u32(skb, RTA_TABLE, table))
5640 		goto nla_put_failure;
5641 
5642 	rtm->rtm_type = rt->fib6_type;
5643 	rtm->rtm_flags = 0;
5644 	rtm->rtm_scope = RT_SCOPE_UNIVERSE;
5645 	rtm->rtm_protocol = rt->fib6_protocol;
5646 
5647 	if (rt6_flags & RTF_CACHE)
5648 		rtm->rtm_flags |= RTM_F_CLONED;
5649 
5650 	if (dest) {
5651 		if (nla_put_in6_addr(skb, RTA_DST, dest))
5652 			goto nla_put_failure;
5653 		rtm->rtm_dst_len = 128;
5654 	} else if (rtm->rtm_dst_len)
5655 		if (nla_put_in6_addr(skb, RTA_DST, &rt6_dst->addr))
5656 			goto nla_put_failure;
5657 #ifdef CONFIG_IPV6_SUBTREES
5658 	if (src) {
5659 		if (nla_put_in6_addr(skb, RTA_SRC, src))
5660 			goto nla_put_failure;
5661 		rtm->rtm_src_len = 128;
5662 	} else if (rtm->rtm_src_len &&
5663 		   nla_put_in6_addr(skb, RTA_SRC, &rt6_src->addr))
5664 		goto nla_put_failure;
5665 #endif
5666 	if (iif) {
5667 #ifdef CONFIG_IPV6_MROUTE
5668 		if (ipv6_addr_is_multicast(&rt6_dst->addr)) {
5669 			int err = ip6mr_get_route(net, skb, rtm, portid);
5670 
5671 			if (err == 0)
5672 				return 0;
5673 			if (err < 0)
5674 				goto nla_put_failure;
5675 		} else
5676 #endif
5677 			if (nla_put_u32(skb, RTA_IIF, iif))
5678 				goto nla_put_failure;
5679 	} else if (dest) {
5680 		struct in6_addr saddr_buf;
5681 		if (ip6_route_get_saddr(net, rt, dest, 0, &saddr_buf) == 0 &&
5682 		    nla_put_in6_addr(skb, RTA_PREFSRC, &saddr_buf))
5683 			goto nla_put_failure;
5684 	}
5685 
5686 	if (rt->fib6_prefsrc.plen) {
5687 		struct in6_addr saddr_buf;
5688 		saddr_buf = rt->fib6_prefsrc.addr;
5689 		if (nla_put_in6_addr(skb, RTA_PREFSRC, &saddr_buf))
5690 			goto nla_put_failure;
5691 	}
5692 
5693 	pmetrics = dst ? dst_metrics_ptr(dst) : rt->fib6_metrics->metrics;
5694 	if (rtnetlink_put_metrics(skb, pmetrics) < 0)
5695 		goto nla_put_failure;
5696 
5697 	if (nla_put_u32(skb, RTA_PRIORITY, rt->fib6_metric))
5698 		goto nla_put_failure;
5699 
5700 	/* For multipath routes, walk the siblings list and add
5701 	 * each as a nexthop within RTA_MULTIPATH.
5702 	 */
5703 	if (rt6) {
5704 		if (rt6_flags & RTF_GATEWAY &&
5705 		    nla_put_in6_addr(skb, RTA_GATEWAY, &rt6->rt6i_gateway))
5706 			goto nla_put_failure;
5707 
5708 		if (dst->dev && nla_put_u32(skb, RTA_OIF, dst->dev->ifindex))
5709 			goto nla_put_failure;
5710 
5711 		if (dst->lwtstate &&
5712 		    lwtunnel_fill_encap(skb, dst->lwtstate, RTA_ENCAP, RTA_ENCAP_TYPE) < 0)
5713 			goto nla_put_failure;
5714 	} else if (rt->fib6_nsiblings) {
5715 		struct fib6_info *sibling, *next_sibling;
5716 		struct nlattr *mp;
5717 
5718 		mp = nla_nest_start_noflag(skb, RTA_MULTIPATH);
5719 		if (!mp)
5720 			goto nla_put_failure;
5721 
5722 		if (fib_add_nexthop(skb, &rt->fib6_nh->nh_common,
5723 				    rt->fib6_nh->fib_nh_weight, AF_INET6,
5724 				    0) < 0)
5725 			goto nla_put_failure;
5726 
5727 		list_for_each_entry_safe(sibling, next_sibling,
5728 					 &rt->fib6_siblings, fib6_siblings) {
5729 			if (fib_add_nexthop(skb, &sibling->fib6_nh->nh_common,
5730 					    sibling->fib6_nh->fib_nh_weight,
5731 					    AF_INET6, 0) < 0)
5732 				goto nla_put_failure;
5733 		}
5734 
5735 		nla_nest_end(skb, mp);
5736 	} else if (rt->nh) {
5737 		if (nla_put_u32(skb, RTA_NH_ID, rt->nh->id))
5738 			goto nla_put_failure;
5739 
5740 		if (nexthop_is_blackhole(rt->nh))
5741 			rtm->rtm_type = RTN_BLACKHOLE;
5742 
5743 		if (READ_ONCE(net->ipv4.sysctl_nexthop_compat_mode) &&
5744 		    rt6_fill_node_nexthop(skb, rt->nh, &nh_flags) < 0)
5745 			goto nla_put_failure;
5746 
5747 		rtm->rtm_flags |= nh_flags;
5748 	} else {
5749 		if (fib_nexthop_info(skb, &rt->fib6_nh->nh_common, AF_INET6,
5750 				     &nh_flags, false) < 0)
5751 			goto nla_put_failure;
5752 
5753 		rtm->rtm_flags |= nh_flags;
5754 	}
5755 
5756 	if (rt6_flags & RTF_EXPIRES) {
5757 		expires = dst ? dst->expires : rt->expires;
5758 		expires -= jiffies;
5759 	}
5760 
5761 	if (!dst) {
5762 		if (READ_ONCE(rt->offload))
5763 			rtm->rtm_flags |= RTM_F_OFFLOAD;
5764 		if (READ_ONCE(rt->trap))
5765 			rtm->rtm_flags |= RTM_F_TRAP;
5766 		if (READ_ONCE(rt->offload_failed))
5767 			rtm->rtm_flags |= RTM_F_OFFLOAD_FAILED;
5768 	}
5769 
5770 	if (rtnl_put_cacheinfo(skb, dst, 0, expires, dst ? dst->error : 0) < 0)
5771 		goto nla_put_failure;
5772 
5773 	if (nla_put_u8(skb, RTA_PREF, IPV6_EXTRACT_PREF(rt6_flags)))
5774 		goto nla_put_failure;
5775 
5776 
5777 	nlmsg_end(skb, nlh);
5778 	return 0;
5779 
5780 nla_put_failure:
5781 	nlmsg_cancel(skb, nlh);
5782 	return -EMSGSIZE;
5783 }
5784 
fib6_info_nh_uses_dev(struct fib6_nh * nh,void * arg)5785 static int fib6_info_nh_uses_dev(struct fib6_nh *nh, void *arg)
5786 {
5787 	const struct net_device *dev = arg;
5788 
5789 	if (nh->fib_nh_dev == dev)
5790 		return 1;
5791 
5792 	return 0;
5793 }
5794 
fib6_info_uses_dev(const struct fib6_info * f6i,const struct net_device * dev)5795 static bool fib6_info_uses_dev(const struct fib6_info *f6i,
5796 			       const struct net_device *dev)
5797 {
5798 	if (f6i->nh) {
5799 		struct net_device *_dev = (struct net_device *)dev;
5800 
5801 		return !!nexthop_for_each_fib6_nh(f6i->nh,
5802 						  fib6_info_nh_uses_dev,
5803 						  _dev);
5804 	}
5805 
5806 	if (f6i->fib6_nh->fib_nh_dev == dev)
5807 		return true;
5808 
5809 	if (f6i->fib6_nsiblings) {
5810 		struct fib6_info *sibling, *next_sibling;
5811 
5812 		list_for_each_entry_safe(sibling, next_sibling,
5813 					 &f6i->fib6_siblings, fib6_siblings) {
5814 			if (sibling->fib6_nh->fib_nh_dev == dev)
5815 				return true;
5816 		}
5817 	}
5818 
5819 	return false;
5820 }
5821 
5822 struct fib6_nh_exception_dump_walker {
5823 	struct rt6_rtnl_dump_arg *dump;
5824 	struct fib6_info *rt;
5825 	unsigned int flags;
5826 	unsigned int skip;
5827 	unsigned int count;
5828 };
5829 
rt6_nh_dump_exceptions(struct fib6_nh * nh,void * arg)5830 static int rt6_nh_dump_exceptions(struct fib6_nh *nh, void *arg)
5831 {
5832 	struct fib6_nh_exception_dump_walker *w = arg;
5833 	struct rt6_rtnl_dump_arg *dump = w->dump;
5834 	struct rt6_exception_bucket *bucket;
5835 	struct rt6_exception *rt6_ex;
5836 	int i, err;
5837 
5838 	bucket = fib6_nh_get_excptn_bucket(nh, NULL);
5839 	if (!bucket)
5840 		return 0;
5841 
5842 	for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
5843 		hlist_for_each_entry(rt6_ex, &bucket->chain, hlist) {
5844 			if (w->skip) {
5845 				w->skip--;
5846 				continue;
5847 			}
5848 
5849 			/* Expiration of entries doesn't bump sernum, insertion
5850 			 * does. Removal is triggered by insertion, so we can
5851 			 * rely on the fact that if entries change between two
5852 			 * partial dumps, this node is scanned again completely,
5853 			 * see rt6_insert_exception() and fib6_dump_table().
5854 			 *
5855 			 * Count expired entries we go through as handled
5856 			 * entries that we'll skip next time, in case of partial
5857 			 * node dump. Otherwise, if entries expire meanwhile,
5858 			 * we'll skip the wrong amount.
5859 			 */
5860 			if (rt6_check_expired(rt6_ex->rt6i)) {
5861 				w->count++;
5862 				continue;
5863 			}
5864 
5865 			err = rt6_fill_node(dump->net, dump->skb, w->rt,
5866 					    &rt6_ex->rt6i->dst, NULL, NULL, 0,
5867 					    RTM_NEWROUTE,
5868 					    NETLINK_CB(dump->cb->skb).portid,
5869 					    dump->cb->nlh->nlmsg_seq, w->flags);
5870 			if (err)
5871 				return err;
5872 
5873 			w->count++;
5874 		}
5875 		bucket++;
5876 	}
5877 
5878 	return 0;
5879 }
5880 
5881 /* Return -1 if done with node, number of handled routes on partial dump */
rt6_dump_route(struct fib6_info * rt,void * p_arg,unsigned int skip)5882 int rt6_dump_route(struct fib6_info *rt, void *p_arg, unsigned int skip)
5883 {
5884 	struct rt6_rtnl_dump_arg *arg = (struct rt6_rtnl_dump_arg *) p_arg;
5885 	struct fib_dump_filter *filter = &arg->filter;
5886 	unsigned int flags = NLM_F_MULTI;
5887 	struct net *net = arg->net;
5888 	int count = 0;
5889 
5890 	if (rt == net->ipv6.fib6_null_entry)
5891 		return -1;
5892 
5893 	if ((filter->flags & RTM_F_PREFIX) &&
5894 	    !(rt->fib6_flags & RTF_PREFIX_RT)) {
5895 		/* success since this is not a prefix route */
5896 		return -1;
5897 	}
5898 	if (filter->filter_set &&
5899 	    ((filter->rt_type  && rt->fib6_type != filter->rt_type) ||
5900 	     (filter->dev      && !fib6_info_uses_dev(rt, filter->dev)) ||
5901 	     (filter->protocol && rt->fib6_protocol != filter->protocol))) {
5902 		return -1;
5903 	}
5904 
5905 	if (filter->filter_set ||
5906 	    !filter->dump_routes || !filter->dump_exceptions) {
5907 		flags |= NLM_F_DUMP_FILTERED;
5908 	}
5909 
5910 	if (filter->dump_routes) {
5911 		if (skip) {
5912 			skip--;
5913 		} else {
5914 			if (rt6_fill_node(net, arg->skb, rt, NULL, NULL, NULL,
5915 					  0, RTM_NEWROUTE,
5916 					  NETLINK_CB(arg->cb->skb).portid,
5917 					  arg->cb->nlh->nlmsg_seq, flags)) {
5918 				return 0;
5919 			}
5920 			count++;
5921 		}
5922 	}
5923 
5924 	if (filter->dump_exceptions) {
5925 		struct fib6_nh_exception_dump_walker w = { .dump = arg,
5926 							   .rt = rt,
5927 							   .flags = flags,
5928 							   .skip = skip,
5929 							   .count = 0 };
5930 		int err;
5931 
5932 		rcu_read_lock();
5933 		if (rt->nh) {
5934 			err = nexthop_for_each_fib6_nh(rt->nh,
5935 						       rt6_nh_dump_exceptions,
5936 						       &w);
5937 		} else {
5938 			err = rt6_nh_dump_exceptions(rt->fib6_nh, &w);
5939 		}
5940 		rcu_read_unlock();
5941 
5942 		if (err)
5943 			return count + w.count;
5944 	}
5945 
5946 	return -1;
5947 }
5948 
inet6_rtm_valid_getroute_req(struct sk_buff * skb,const struct nlmsghdr * nlh,struct nlattr ** tb,struct netlink_ext_ack * extack)5949 static int inet6_rtm_valid_getroute_req(struct sk_buff *skb,
5950 					const struct nlmsghdr *nlh,
5951 					struct nlattr **tb,
5952 					struct netlink_ext_ack *extack)
5953 {
5954 	struct rtmsg *rtm;
5955 	int i, err;
5956 
5957 	if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) {
5958 		NL_SET_ERR_MSG_MOD(extack,
5959 				   "Invalid header for get route request");
5960 		return -EINVAL;
5961 	}
5962 
5963 	if (!netlink_strict_get_check(skb))
5964 		return nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX,
5965 					      rtm_ipv6_policy, extack);
5966 
5967 	rtm = nlmsg_data(nlh);
5968 	if ((rtm->rtm_src_len && rtm->rtm_src_len != 128) ||
5969 	    (rtm->rtm_dst_len && rtm->rtm_dst_len != 128) ||
5970 	    rtm->rtm_table || rtm->rtm_protocol || rtm->rtm_scope ||
5971 	    rtm->rtm_type) {
5972 		NL_SET_ERR_MSG_MOD(extack, "Invalid values in header for get route request");
5973 		return -EINVAL;
5974 	}
5975 	if (rtm->rtm_flags & ~RTM_F_FIB_MATCH) {
5976 		NL_SET_ERR_MSG_MOD(extack,
5977 				   "Invalid flags for get route request");
5978 		return -EINVAL;
5979 	}
5980 
5981 	err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX,
5982 					    rtm_ipv6_policy, extack);
5983 	if (err)
5984 		return err;
5985 
5986 	if ((tb[RTA_SRC] && !rtm->rtm_src_len) ||
5987 	    (tb[RTA_DST] && !rtm->rtm_dst_len)) {
5988 		NL_SET_ERR_MSG_MOD(extack, "rtm_src_len and rtm_dst_len must be 128 for IPv6");
5989 		return -EINVAL;
5990 	}
5991 
5992 	for (i = 0; i <= RTA_MAX; i++) {
5993 		if (!tb[i])
5994 			continue;
5995 
5996 		switch (i) {
5997 		case RTA_SRC:
5998 		case RTA_DST:
5999 		case RTA_IIF:
6000 		case RTA_OIF:
6001 		case RTA_MARK:
6002 		case RTA_UID:
6003 		case RTA_SPORT:
6004 		case RTA_DPORT:
6005 		case RTA_IP_PROTO:
6006 			break;
6007 		default:
6008 			NL_SET_ERR_MSG_MOD(extack, "Unsupported attribute in get route request");
6009 			return -EINVAL;
6010 		}
6011 	}
6012 
6013 	return 0;
6014 }
6015 
inet6_rtm_getroute(struct sk_buff * in_skb,struct nlmsghdr * nlh,struct netlink_ext_ack * extack)6016 static int inet6_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
6017 			      struct netlink_ext_ack *extack)
6018 {
6019 	struct net *net = sock_net(in_skb->sk);
6020 	struct nlattr *tb[RTA_MAX+1];
6021 	int err, iif = 0, oif = 0;
6022 	struct fib6_info *from;
6023 	struct dst_entry *dst;
6024 	struct rt6_info *rt;
6025 	struct sk_buff *skb;
6026 	struct rtmsg *rtm;
6027 	struct flowi6 fl6 = {};
6028 	bool fibmatch;
6029 
6030 	err = inet6_rtm_valid_getroute_req(in_skb, nlh, tb, extack);
6031 	if (err < 0)
6032 		goto errout;
6033 
6034 	err = -EINVAL;
6035 	rtm = nlmsg_data(nlh);
6036 	fl6.flowlabel = ip6_make_flowinfo(rtm->rtm_tos, 0);
6037 	fibmatch = !!(rtm->rtm_flags & RTM_F_FIB_MATCH);
6038 
6039 	if (tb[RTA_SRC]) {
6040 		if (nla_len(tb[RTA_SRC]) < sizeof(struct in6_addr))
6041 			goto errout;
6042 
6043 		fl6.saddr = *(struct in6_addr *)nla_data(tb[RTA_SRC]);
6044 	}
6045 
6046 	if (tb[RTA_DST]) {
6047 		if (nla_len(tb[RTA_DST]) < sizeof(struct in6_addr))
6048 			goto errout;
6049 
6050 		fl6.daddr = *(struct in6_addr *)nla_data(tb[RTA_DST]);
6051 	}
6052 
6053 	if (tb[RTA_IIF])
6054 		iif = nla_get_u32(tb[RTA_IIF]);
6055 
6056 	if (tb[RTA_OIF])
6057 		oif = nla_get_u32(tb[RTA_OIF]);
6058 
6059 	if (tb[RTA_MARK])
6060 		fl6.flowi6_mark = nla_get_u32(tb[RTA_MARK]);
6061 
6062 	if (tb[RTA_UID])
6063 		fl6.flowi6_uid = make_kuid(current_user_ns(),
6064 					   nla_get_u32(tb[RTA_UID]));
6065 	else
6066 		fl6.flowi6_uid = iif ? INVALID_UID : current_uid();
6067 
6068 	if (tb[RTA_SPORT])
6069 		fl6.fl6_sport = nla_get_be16(tb[RTA_SPORT]);
6070 
6071 	if (tb[RTA_DPORT])
6072 		fl6.fl6_dport = nla_get_be16(tb[RTA_DPORT]);
6073 
6074 	if (tb[RTA_IP_PROTO]) {
6075 		err = rtm_getroute_parse_ip_proto(tb[RTA_IP_PROTO],
6076 						  &fl6.flowi6_proto, AF_INET6,
6077 						  extack);
6078 		if (err)
6079 			goto errout;
6080 	}
6081 
6082 	if (iif) {
6083 		struct net_device *dev;
6084 		int flags = 0;
6085 
6086 		rcu_read_lock();
6087 
6088 		dev = dev_get_by_index_rcu(net, iif);
6089 		if (!dev) {
6090 			rcu_read_unlock();
6091 			err = -ENODEV;
6092 			goto errout;
6093 		}
6094 
6095 		fl6.flowi6_iif = iif;
6096 
6097 		if (!ipv6_addr_any(&fl6.saddr))
6098 			flags |= RT6_LOOKUP_F_HAS_SADDR;
6099 
6100 		dst = ip6_route_input_lookup(net, dev, &fl6, NULL, flags);
6101 
6102 		rcu_read_unlock();
6103 	} else {
6104 		fl6.flowi6_oif = oif;
6105 
6106 		dst = ip6_route_output(net, NULL, &fl6);
6107 	}
6108 
6109 
6110 	rt = container_of(dst, struct rt6_info, dst);
6111 	if (rt->dst.error) {
6112 		err = rt->dst.error;
6113 		ip6_rt_put(rt);
6114 		goto errout;
6115 	}
6116 
6117 	if (rt == net->ipv6.ip6_null_entry) {
6118 		err = rt->dst.error;
6119 		ip6_rt_put(rt);
6120 		goto errout;
6121 	}
6122 
6123 	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
6124 	if (!skb) {
6125 		ip6_rt_put(rt);
6126 		err = -ENOBUFS;
6127 		goto errout;
6128 	}
6129 
6130 	skb_dst_set(skb, &rt->dst);
6131 
6132 	rcu_read_lock();
6133 	from = rcu_dereference(rt->from);
6134 	if (from) {
6135 		if (fibmatch)
6136 			err = rt6_fill_node(net, skb, from, NULL, NULL, NULL,
6137 					    iif, RTM_NEWROUTE,
6138 					    NETLINK_CB(in_skb).portid,
6139 					    nlh->nlmsg_seq, 0);
6140 		else
6141 			err = rt6_fill_node(net, skb, from, dst, &fl6.daddr,
6142 					    &fl6.saddr, iif, RTM_NEWROUTE,
6143 					    NETLINK_CB(in_skb).portid,
6144 					    nlh->nlmsg_seq, 0);
6145 	} else {
6146 		err = -ENETUNREACH;
6147 	}
6148 	rcu_read_unlock();
6149 
6150 	if (err < 0) {
6151 		kfree_skb(skb);
6152 		goto errout;
6153 	}
6154 
6155 	err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
6156 errout:
6157 	return err;
6158 }
6159 
inet6_rt_notify(int event,struct fib6_info * rt,struct nl_info * info,unsigned int nlm_flags)6160 void inet6_rt_notify(int event, struct fib6_info *rt, struct nl_info *info,
6161 		     unsigned int nlm_flags)
6162 {
6163 	struct sk_buff *skb;
6164 	struct net *net = info->nl_net;
6165 	u32 seq;
6166 	int err;
6167 
6168 	err = -ENOBUFS;
6169 	seq = info->nlh ? info->nlh->nlmsg_seq : 0;
6170 
6171 	skb = nlmsg_new(rt6_nlmsg_size(rt), gfp_any());
6172 	if (!skb)
6173 		goto errout;
6174 
6175 	err = rt6_fill_node(net, skb, rt, NULL, NULL, NULL, 0,
6176 			    event, info->portid, seq, nlm_flags);
6177 	if (err < 0) {
6178 		/* -EMSGSIZE implies BUG in rt6_nlmsg_size() */
6179 		WARN_ON(err == -EMSGSIZE);
6180 		kfree_skb(skb);
6181 		goto errout;
6182 	}
6183 	rtnl_notify(skb, net, info->portid, RTNLGRP_IPV6_ROUTE,
6184 		    info->nlh, gfp_any());
6185 	return;
6186 errout:
6187 	if (err < 0)
6188 		rtnl_set_sk_err(net, RTNLGRP_IPV6_ROUTE, err);
6189 }
6190 
fib6_rt_update(struct net * net,struct fib6_info * rt,struct nl_info * info)6191 void fib6_rt_update(struct net *net, struct fib6_info *rt,
6192 		    struct nl_info *info)
6193 {
6194 	u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0;
6195 	struct sk_buff *skb;
6196 	int err = -ENOBUFS;
6197 
6198 	skb = nlmsg_new(rt6_nlmsg_size(rt), gfp_any());
6199 	if (!skb)
6200 		goto errout;
6201 
6202 	err = rt6_fill_node(net, skb, rt, NULL, NULL, NULL, 0,
6203 			    RTM_NEWROUTE, info->portid, seq, NLM_F_REPLACE);
6204 	if (err < 0) {
6205 		/* -EMSGSIZE implies BUG in rt6_nlmsg_size() */
6206 		WARN_ON(err == -EMSGSIZE);
6207 		kfree_skb(skb);
6208 		goto errout;
6209 	}
6210 	rtnl_notify(skb, net, info->portid, RTNLGRP_IPV6_ROUTE,
6211 		    info->nlh, gfp_any());
6212 	return;
6213 errout:
6214 	if (err < 0)
6215 		rtnl_set_sk_err(net, RTNLGRP_IPV6_ROUTE, err);
6216 }
6217 
fib6_info_hw_flags_set(struct net * net,struct fib6_info * f6i,bool offload,bool trap,bool offload_failed)6218 void fib6_info_hw_flags_set(struct net *net, struct fib6_info *f6i,
6219 			    bool offload, bool trap, bool offload_failed)
6220 {
6221 	struct sk_buff *skb;
6222 	int err;
6223 
6224 	if (READ_ONCE(f6i->offload) == offload &&
6225 	    READ_ONCE(f6i->trap) == trap &&
6226 	    READ_ONCE(f6i->offload_failed) == offload_failed)
6227 		return;
6228 
6229 	WRITE_ONCE(f6i->offload, offload);
6230 	WRITE_ONCE(f6i->trap, trap);
6231 
6232 	/* 2 means send notifications only if offload_failed was changed. */
6233 	if (net->ipv6.sysctl.fib_notify_on_flag_change == 2 &&
6234 	    READ_ONCE(f6i->offload_failed) == offload_failed)
6235 		return;
6236 
6237 	WRITE_ONCE(f6i->offload_failed, offload_failed);
6238 
6239 	if (!rcu_access_pointer(f6i->fib6_node))
6240 		/* The route was removed from the tree, do not send
6241 		 * notification.
6242 		 */
6243 		return;
6244 
6245 	if (!net->ipv6.sysctl.fib_notify_on_flag_change)
6246 		return;
6247 
6248 	skb = nlmsg_new(rt6_nlmsg_size(f6i), GFP_KERNEL);
6249 	if (!skb) {
6250 		err = -ENOBUFS;
6251 		goto errout;
6252 	}
6253 
6254 	err = rt6_fill_node(net, skb, f6i, NULL, NULL, NULL, 0, RTM_NEWROUTE, 0,
6255 			    0, 0);
6256 	if (err < 0) {
6257 		/* -EMSGSIZE implies BUG in rt6_nlmsg_size() */
6258 		WARN_ON(err == -EMSGSIZE);
6259 		kfree_skb(skb);
6260 		goto errout;
6261 	}
6262 
6263 	rtnl_notify(skb, net, 0, RTNLGRP_IPV6_ROUTE, NULL, GFP_KERNEL);
6264 	return;
6265 
6266 errout:
6267 	rtnl_set_sk_err(net, RTNLGRP_IPV6_ROUTE, err);
6268 }
6269 EXPORT_SYMBOL(fib6_info_hw_flags_set);
6270 
ip6_route_dev_notify(struct notifier_block * this,unsigned long event,void * ptr)6271 static int ip6_route_dev_notify(struct notifier_block *this,
6272 				unsigned long event, void *ptr)
6273 {
6274 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
6275 	struct net *net = dev_net(dev);
6276 
6277 	if (!(dev->flags & IFF_LOOPBACK))
6278 		return NOTIFY_OK;
6279 
6280 	if (event == NETDEV_REGISTER) {
6281 		net->ipv6.fib6_null_entry->fib6_nh->fib_nh_dev = dev;
6282 		net->ipv6.ip6_null_entry->dst.dev = dev;
6283 		net->ipv6.ip6_null_entry->rt6i_idev = in6_dev_get(dev);
6284 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
6285 		net->ipv6.ip6_prohibit_entry->dst.dev = dev;
6286 		net->ipv6.ip6_prohibit_entry->rt6i_idev = in6_dev_get(dev);
6287 		net->ipv6.ip6_blk_hole_entry->dst.dev = dev;
6288 		net->ipv6.ip6_blk_hole_entry->rt6i_idev = in6_dev_get(dev);
6289 #endif
6290 	 } else if (event == NETDEV_UNREGISTER &&
6291 		    dev->reg_state != NETREG_UNREGISTERED) {
6292 		/* NETDEV_UNREGISTER could be fired for multiple times by
6293 		 * netdev_wait_allrefs(). Make sure we only call this once.
6294 		 */
6295 		in6_dev_put_clear(&net->ipv6.ip6_null_entry->rt6i_idev);
6296 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
6297 		in6_dev_put_clear(&net->ipv6.ip6_prohibit_entry->rt6i_idev);
6298 		in6_dev_put_clear(&net->ipv6.ip6_blk_hole_entry->rt6i_idev);
6299 #endif
6300 	}
6301 
6302 	return NOTIFY_OK;
6303 }
6304 
6305 /*
6306  *	/proc
6307  */
6308 
6309 #ifdef CONFIG_PROC_FS
rt6_stats_seq_show(struct seq_file * seq,void * v)6310 static int rt6_stats_seq_show(struct seq_file *seq, void *v)
6311 {
6312 	struct net *net = (struct net *)seq->private;
6313 	seq_printf(seq, "%04x %04x %04x %04x %04x %04x %04x\n",
6314 		   net->ipv6.rt6_stats->fib_nodes,
6315 		   net->ipv6.rt6_stats->fib_route_nodes,
6316 		   atomic_read(&net->ipv6.rt6_stats->fib_rt_alloc),
6317 		   net->ipv6.rt6_stats->fib_rt_entries,
6318 		   net->ipv6.rt6_stats->fib_rt_cache,
6319 		   dst_entries_get_slow(&net->ipv6.ip6_dst_ops),
6320 		   net->ipv6.rt6_stats->fib_discarded_routes);
6321 
6322 	return 0;
6323 }
6324 #endif	/* CONFIG_PROC_FS */
6325 
6326 #ifdef CONFIG_SYSCTL
6327 
ipv6_sysctl_rtcache_flush(struct ctl_table * ctl,int write,void * buffer,size_t * lenp,loff_t * ppos)6328 static int ipv6_sysctl_rtcache_flush(struct ctl_table *ctl, int write,
6329 			      void *buffer, size_t *lenp, loff_t *ppos)
6330 {
6331 	struct net *net;
6332 	int delay;
6333 	int ret;
6334 	if (!write)
6335 		return -EINVAL;
6336 
6337 	net = (struct net *)ctl->extra1;
6338 	delay = net->ipv6.sysctl.flush_delay;
6339 	ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
6340 	if (ret)
6341 		return ret;
6342 
6343 	fib6_run_gc(delay <= 0 ? 0 : (unsigned long)delay, net, delay > 0);
6344 	return 0;
6345 }
6346 
6347 static struct ctl_table ipv6_route_table_template[] = {
6348 	{
6349 		.procname	=	"max_size",
6350 		.data		=	&init_net.ipv6.sysctl.ip6_rt_max_size,
6351 		.maxlen		=	sizeof(int),
6352 		.mode		=	0644,
6353 		.proc_handler	=	proc_dointvec,
6354 	},
6355 	{
6356 		.procname	=	"gc_thresh",
6357 		.data		=	&ip6_dst_ops_template.gc_thresh,
6358 		.maxlen		=	sizeof(int),
6359 		.mode		=	0644,
6360 		.proc_handler	=	proc_dointvec,
6361 	},
6362 	{
6363 		.procname	=	"flush",
6364 		.data		=	&init_net.ipv6.sysctl.flush_delay,
6365 		.maxlen		=	sizeof(int),
6366 		.mode		=	0200,
6367 		.proc_handler	=	ipv6_sysctl_rtcache_flush
6368 	},
6369 	{
6370 		.procname	=	"gc_min_interval",
6371 		.data		=	&init_net.ipv6.sysctl.ip6_rt_gc_min_interval,
6372 		.maxlen		=	sizeof(int),
6373 		.mode		=	0644,
6374 		.proc_handler	=	proc_dointvec_jiffies,
6375 	},
6376 	{
6377 		.procname	=	"gc_timeout",
6378 		.data		=	&init_net.ipv6.sysctl.ip6_rt_gc_timeout,
6379 		.maxlen		=	sizeof(int),
6380 		.mode		=	0644,
6381 		.proc_handler	=	proc_dointvec_jiffies,
6382 	},
6383 	{
6384 		.procname	=	"gc_interval",
6385 		.data		=	&init_net.ipv6.sysctl.ip6_rt_gc_interval,
6386 		.maxlen		=	sizeof(int),
6387 		.mode		=	0644,
6388 		.proc_handler	=	proc_dointvec_jiffies,
6389 	},
6390 	{
6391 		.procname	=	"gc_elasticity",
6392 		.data		=	&init_net.ipv6.sysctl.ip6_rt_gc_elasticity,
6393 		.maxlen		=	sizeof(int),
6394 		.mode		=	0644,
6395 		.proc_handler	=	proc_dointvec,
6396 	},
6397 	{
6398 		.procname	=	"mtu_expires",
6399 		.data		=	&init_net.ipv6.sysctl.ip6_rt_mtu_expires,
6400 		.maxlen		=	sizeof(int),
6401 		.mode		=	0644,
6402 		.proc_handler	=	proc_dointvec_jiffies,
6403 	},
6404 	{
6405 		.procname	=	"min_adv_mss",
6406 		.data		=	&init_net.ipv6.sysctl.ip6_rt_min_advmss,
6407 		.maxlen		=	sizeof(int),
6408 		.mode		=	0644,
6409 		.proc_handler	=	proc_dointvec,
6410 	},
6411 	{
6412 		.procname	=	"gc_min_interval_ms",
6413 		.data		=	&init_net.ipv6.sysctl.ip6_rt_gc_min_interval,
6414 		.maxlen		=	sizeof(int),
6415 		.mode		=	0644,
6416 		.proc_handler	=	proc_dointvec_ms_jiffies,
6417 	},
6418 	{
6419 		.procname	=	"skip_notify_on_dev_down",
6420 		.data		=	&init_net.ipv6.sysctl.skip_notify_on_dev_down,
6421 		.maxlen		=	sizeof(u8),
6422 		.mode		=	0644,
6423 		.proc_handler	=	proc_dou8vec_minmax,
6424 		.extra1		=	SYSCTL_ZERO,
6425 		.extra2		=	SYSCTL_ONE,
6426 	},
6427 	{ }
6428 };
6429 
ipv6_route_sysctl_init(struct net * net)6430 struct ctl_table * __net_init ipv6_route_sysctl_init(struct net *net)
6431 {
6432 	struct ctl_table *table;
6433 
6434 	table = kmemdup(ipv6_route_table_template,
6435 			sizeof(ipv6_route_table_template),
6436 			GFP_KERNEL);
6437 
6438 	if (table) {
6439 		table[0].data = &net->ipv6.sysctl.ip6_rt_max_size;
6440 		table[1].data = &net->ipv6.ip6_dst_ops.gc_thresh;
6441 		table[2].data = &net->ipv6.sysctl.flush_delay;
6442 		table[2].extra1 = net;
6443 		table[3].data = &net->ipv6.sysctl.ip6_rt_gc_min_interval;
6444 		table[4].data = &net->ipv6.sysctl.ip6_rt_gc_timeout;
6445 		table[5].data = &net->ipv6.sysctl.ip6_rt_gc_interval;
6446 		table[6].data = &net->ipv6.sysctl.ip6_rt_gc_elasticity;
6447 		table[7].data = &net->ipv6.sysctl.ip6_rt_mtu_expires;
6448 		table[8].data = &net->ipv6.sysctl.ip6_rt_min_advmss;
6449 		table[9].data = &net->ipv6.sysctl.ip6_rt_gc_min_interval;
6450 		table[10].data = &net->ipv6.sysctl.skip_notify_on_dev_down;
6451 
6452 		/* Don't export sysctls to unprivileged users */
6453 		if (net->user_ns != &init_user_ns)
6454 			table[1].procname = NULL;
6455 	}
6456 
6457 	return table;
6458 }
6459 
ipv6_route_sysctl_table_size(struct net * net)6460 size_t ipv6_route_sysctl_table_size(struct net *net)
6461 {
6462 	/* Don't export sysctls to unprivileged users */
6463 	if (net->user_ns != &init_user_ns)
6464 		return 1;
6465 
6466 	return ARRAY_SIZE(ipv6_route_table_template);
6467 }
6468 #endif
6469 
ip6_route_net_init(struct net * net)6470 static int __net_init ip6_route_net_init(struct net *net)
6471 {
6472 	int ret = -ENOMEM;
6473 
6474 	memcpy(&net->ipv6.ip6_dst_ops, &ip6_dst_ops_template,
6475 	       sizeof(net->ipv6.ip6_dst_ops));
6476 
6477 	if (dst_entries_init(&net->ipv6.ip6_dst_ops) < 0)
6478 		goto out_ip6_dst_ops;
6479 
6480 	net->ipv6.fib6_null_entry = fib6_info_alloc(GFP_KERNEL, true);
6481 	if (!net->ipv6.fib6_null_entry)
6482 		goto out_ip6_dst_entries;
6483 	memcpy(net->ipv6.fib6_null_entry, &fib6_null_entry_template,
6484 	       sizeof(*net->ipv6.fib6_null_entry));
6485 
6486 	net->ipv6.ip6_null_entry = kmemdup(&ip6_null_entry_template,
6487 					   sizeof(*net->ipv6.ip6_null_entry),
6488 					   GFP_KERNEL);
6489 	if (!net->ipv6.ip6_null_entry)
6490 		goto out_fib6_null_entry;
6491 	net->ipv6.ip6_null_entry->dst.ops = &net->ipv6.ip6_dst_ops;
6492 	dst_init_metrics(&net->ipv6.ip6_null_entry->dst,
6493 			 ip6_template_metrics, true);
6494 	INIT_LIST_HEAD(&net->ipv6.ip6_null_entry->dst.rt_uncached);
6495 
6496 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
6497 	net->ipv6.fib6_has_custom_rules = false;
6498 	net->ipv6.ip6_prohibit_entry = kmemdup(&ip6_prohibit_entry_template,
6499 					       sizeof(*net->ipv6.ip6_prohibit_entry),
6500 					       GFP_KERNEL);
6501 	if (!net->ipv6.ip6_prohibit_entry)
6502 		goto out_ip6_null_entry;
6503 	net->ipv6.ip6_prohibit_entry->dst.ops = &net->ipv6.ip6_dst_ops;
6504 	dst_init_metrics(&net->ipv6.ip6_prohibit_entry->dst,
6505 			 ip6_template_metrics, true);
6506 	INIT_LIST_HEAD(&net->ipv6.ip6_prohibit_entry->dst.rt_uncached);
6507 
6508 	net->ipv6.ip6_blk_hole_entry = kmemdup(&ip6_blk_hole_entry_template,
6509 					       sizeof(*net->ipv6.ip6_blk_hole_entry),
6510 					       GFP_KERNEL);
6511 	if (!net->ipv6.ip6_blk_hole_entry)
6512 		goto out_ip6_prohibit_entry;
6513 	net->ipv6.ip6_blk_hole_entry->dst.ops = &net->ipv6.ip6_dst_ops;
6514 	dst_init_metrics(&net->ipv6.ip6_blk_hole_entry->dst,
6515 			 ip6_template_metrics, true);
6516 	INIT_LIST_HEAD(&net->ipv6.ip6_blk_hole_entry->dst.rt_uncached);
6517 #ifdef CONFIG_IPV6_SUBTREES
6518 	net->ipv6.fib6_routes_require_src = 0;
6519 #endif
6520 #endif
6521 
6522 	net->ipv6.sysctl.flush_delay = 0;
6523 	net->ipv6.sysctl.ip6_rt_max_size = INT_MAX;
6524 	net->ipv6.sysctl.ip6_rt_gc_min_interval = HZ / 2;
6525 	net->ipv6.sysctl.ip6_rt_gc_timeout = 60*HZ;
6526 	net->ipv6.sysctl.ip6_rt_gc_interval = 30*HZ;
6527 	net->ipv6.sysctl.ip6_rt_gc_elasticity = 9;
6528 	net->ipv6.sysctl.ip6_rt_mtu_expires = 10*60*HZ;
6529 	net->ipv6.sysctl.ip6_rt_min_advmss = IPV6_MIN_MTU - 20 - 40;
6530 	net->ipv6.sysctl.skip_notify_on_dev_down = 0;
6531 
6532 	atomic_set(&net->ipv6.ip6_rt_gc_expire, 30*HZ);
6533 
6534 	ret = 0;
6535 out:
6536 	return ret;
6537 
6538 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
6539 out_ip6_prohibit_entry:
6540 	kfree(net->ipv6.ip6_prohibit_entry);
6541 out_ip6_null_entry:
6542 	kfree(net->ipv6.ip6_null_entry);
6543 #endif
6544 out_fib6_null_entry:
6545 	kfree(net->ipv6.fib6_null_entry);
6546 out_ip6_dst_entries:
6547 	dst_entries_destroy(&net->ipv6.ip6_dst_ops);
6548 out_ip6_dst_ops:
6549 	goto out;
6550 }
6551 
ip6_route_net_exit(struct net * net)6552 static void __net_exit ip6_route_net_exit(struct net *net)
6553 {
6554 	kfree(net->ipv6.fib6_null_entry);
6555 	kfree(net->ipv6.ip6_null_entry);
6556 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
6557 	kfree(net->ipv6.ip6_prohibit_entry);
6558 	kfree(net->ipv6.ip6_blk_hole_entry);
6559 #endif
6560 	dst_entries_destroy(&net->ipv6.ip6_dst_ops);
6561 }
6562 
ip6_route_net_init_late(struct net * net)6563 static int __net_init ip6_route_net_init_late(struct net *net)
6564 {
6565 #ifdef CONFIG_PROC_FS
6566 	if (!proc_create_net("ipv6_route", 0, net->proc_net,
6567 			     &ipv6_route_seq_ops,
6568 			     sizeof(struct ipv6_route_iter)))
6569 		return -ENOMEM;
6570 
6571 	if (!proc_create_net_single("rt6_stats", 0444, net->proc_net,
6572 				    rt6_stats_seq_show, NULL)) {
6573 		remove_proc_entry("ipv6_route", net->proc_net);
6574 		return -ENOMEM;
6575 	}
6576 #endif
6577 	return 0;
6578 }
6579 
ip6_route_net_exit_late(struct net * net)6580 static void __net_exit ip6_route_net_exit_late(struct net *net)
6581 {
6582 #ifdef CONFIG_PROC_FS
6583 	remove_proc_entry("ipv6_route", net->proc_net);
6584 	remove_proc_entry("rt6_stats", net->proc_net);
6585 #endif
6586 }
6587 
6588 static struct pernet_operations ip6_route_net_ops = {
6589 	.init = ip6_route_net_init,
6590 	.exit = ip6_route_net_exit,
6591 };
6592 
ipv6_inetpeer_init(struct net * net)6593 static int __net_init ipv6_inetpeer_init(struct net *net)
6594 {
6595 	struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL);
6596 
6597 	if (!bp)
6598 		return -ENOMEM;
6599 	inet_peer_base_init(bp);
6600 	net->ipv6.peers = bp;
6601 	return 0;
6602 }
6603 
ipv6_inetpeer_exit(struct net * net)6604 static void __net_exit ipv6_inetpeer_exit(struct net *net)
6605 {
6606 	struct inet_peer_base *bp = net->ipv6.peers;
6607 
6608 	net->ipv6.peers = NULL;
6609 	inetpeer_invalidate_tree(bp);
6610 	kfree(bp);
6611 }
6612 
6613 static struct pernet_operations ipv6_inetpeer_ops = {
6614 	.init	=	ipv6_inetpeer_init,
6615 	.exit	=	ipv6_inetpeer_exit,
6616 };
6617 
6618 static struct pernet_operations ip6_route_net_late_ops = {
6619 	.init = ip6_route_net_init_late,
6620 	.exit = ip6_route_net_exit_late,
6621 };
6622 
6623 static struct notifier_block ip6_route_dev_notifier = {
6624 	.notifier_call = ip6_route_dev_notify,
6625 	.priority = ADDRCONF_NOTIFY_PRIORITY - 10,
6626 };
6627 
ip6_route_init_special_entries(void)6628 void __init ip6_route_init_special_entries(void)
6629 {
6630 	/* Registering of the loopback is done before this portion of code,
6631 	 * the loopback reference in rt6_info will not be taken, do it
6632 	 * manually for init_net */
6633 	init_net.ipv6.fib6_null_entry->fib6_nh->fib_nh_dev = init_net.loopback_dev;
6634 	init_net.ipv6.ip6_null_entry->dst.dev = init_net.loopback_dev;
6635 	init_net.ipv6.ip6_null_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
6636   #ifdef CONFIG_IPV6_MULTIPLE_TABLES
6637 	init_net.ipv6.ip6_prohibit_entry->dst.dev = init_net.loopback_dev;
6638 	init_net.ipv6.ip6_prohibit_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
6639 	init_net.ipv6.ip6_blk_hole_entry->dst.dev = init_net.loopback_dev;
6640 	init_net.ipv6.ip6_blk_hole_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
6641   #endif
6642 }
6643 
6644 #if IS_BUILTIN(CONFIG_IPV6)
6645 #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS)
6646 DEFINE_BPF_ITER_FUNC(ipv6_route, struct bpf_iter_meta *meta, struct fib6_info *rt)
6647 
6648 BTF_ID_LIST(btf_fib6_info_id)
6649 BTF_ID(struct, fib6_info)
6650 
6651 static const struct bpf_iter_seq_info ipv6_route_seq_info = {
6652 	.seq_ops		= &ipv6_route_seq_ops,
6653 	.init_seq_private	= bpf_iter_init_seq_net,
6654 	.fini_seq_private	= bpf_iter_fini_seq_net,
6655 	.seq_priv_size		= sizeof(struct ipv6_route_iter),
6656 };
6657 
6658 static struct bpf_iter_reg ipv6_route_reg_info = {
6659 	.target			= "ipv6_route",
6660 	.ctx_arg_info_size	= 1,
6661 	.ctx_arg_info		= {
6662 		{ offsetof(struct bpf_iter__ipv6_route, rt),
6663 		  PTR_TO_BTF_ID_OR_NULL },
6664 	},
6665 	.seq_info		= &ipv6_route_seq_info,
6666 };
6667 
bpf_iter_register(void)6668 static int __init bpf_iter_register(void)
6669 {
6670 	ipv6_route_reg_info.ctx_arg_info[0].btf_id = *btf_fib6_info_id;
6671 	return bpf_iter_reg_target(&ipv6_route_reg_info);
6672 }
6673 
bpf_iter_unregister(void)6674 static void bpf_iter_unregister(void)
6675 {
6676 	bpf_iter_unreg_target(&ipv6_route_reg_info);
6677 }
6678 #endif
6679 #endif
6680 
ip6_route_init(void)6681 int __init ip6_route_init(void)
6682 {
6683 	int ret;
6684 	int cpu;
6685 
6686 	ret = -ENOMEM;
6687 	ip6_dst_ops_template.kmem_cachep =
6688 		kmem_cache_create("ip6_dst_cache", sizeof(struct rt6_info), 0,
6689 				  SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT, NULL);
6690 	if (!ip6_dst_ops_template.kmem_cachep)
6691 		goto out;
6692 
6693 	ret = dst_entries_init(&ip6_dst_blackhole_ops);
6694 	if (ret)
6695 		goto out_kmem_cache;
6696 
6697 	ret = register_pernet_subsys(&ipv6_inetpeer_ops);
6698 	if (ret)
6699 		goto out_dst_entries;
6700 
6701 	ret = register_pernet_subsys(&ip6_route_net_ops);
6702 	if (ret)
6703 		goto out_register_inetpeer;
6704 
6705 	ip6_dst_blackhole_ops.kmem_cachep = ip6_dst_ops_template.kmem_cachep;
6706 
6707 	ret = fib6_init();
6708 	if (ret)
6709 		goto out_register_subsys;
6710 
6711 	ret = xfrm6_init();
6712 	if (ret)
6713 		goto out_fib6_init;
6714 
6715 	ret = fib6_rules_init();
6716 	if (ret)
6717 		goto xfrm6_init;
6718 
6719 	ret = register_pernet_subsys(&ip6_route_net_late_ops);
6720 	if (ret)
6721 		goto fib6_rules_init;
6722 
6723 	ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_NEWROUTE,
6724 				   inet6_rtm_newroute, NULL, 0);
6725 	if (ret < 0)
6726 		goto out_register_late_subsys;
6727 
6728 	ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_DELROUTE,
6729 				   inet6_rtm_delroute, NULL, 0);
6730 	if (ret < 0)
6731 		goto out_register_late_subsys;
6732 
6733 	ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_GETROUTE,
6734 				   inet6_rtm_getroute, NULL,
6735 				   RTNL_FLAG_DOIT_UNLOCKED);
6736 	if (ret < 0)
6737 		goto out_register_late_subsys;
6738 
6739 	ret = register_netdevice_notifier(&ip6_route_dev_notifier);
6740 	if (ret)
6741 		goto out_register_late_subsys;
6742 
6743 #if IS_BUILTIN(CONFIG_IPV6)
6744 #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS)
6745 	ret = bpf_iter_register();
6746 	if (ret)
6747 		goto out_register_late_subsys;
6748 #endif
6749 #endif
6750 
6751 	for_each_possible_cpu(cpu) {
6752 		struct uncached_list *ul = per_cpu_ptr(&rt6_uncached_list, cpu);
6753 
6754 		INIT_LIST_HEAD(&ul->head);
6755 		INIT_LIST_HEAD(&ul->quarantine);
6756 		spin_lock_init(&ul->lock);
6757 	}
6758 
6759 out:
6760 	return ret;
6761 
6762 out_register_late_subsys:
6763 	rtnl_unregister_all(PF_INET6);
6764 	unregister_pernet_subsys(&ip6_route_net_late_ops);
6765 fib6_rules_init:
6766 	fib6_rules_cleanup();
6767 xfrm6_init:
6768 	xfrm6_fini();
6769 out_fib6_init:
6770 	fib6_gc_cleanup();
6771 out_register_subsys:
6772 	unregister_pernet_subsys(&ip6_route_net_ops);
6773 out_register_inetpeer:
6774 	unregister_pernet_subsys(&ipv6_inetpeer_ops);
6775 out_dst_entries:
6776 	dst_entries_destroy(&ip6_dst_blackhole_ops);
6777 out_kmem_cache:
6778 	kmem_cache_destroy(ip6_dst_ops_template.kmem_cachep);
6779 	goto out;
6780 }
6781 
ip6_route_cleanup(void)6782 void ip6_route_cleanup(void)
6783 {
6784 #if IS_BUILTIN(CONFIG_IPV6)
6785 #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS)
6786 	bpf_iter_unregister();
6787 #endif
6788 #endif
6789 	unregister_netdevice_notifier(&ip6_route_dev_notifier);
6790 	unregister_pernet_subsys(&ip6_route_net_late_ops);
6791 	fib6_rules_cleanup();
6792 	xfrm6_fini();
6793 	fib6_gc_cleanup();
6794 	unregister_pernet_subsys(&ipv6_inetpeer_ops);
6795 	unregister_pernet_subsys(&ip6_route_net_ops);
6796 	dst_entries_destroy(&ip6_dst_blackhole_ops);
6797 	kmem_cache_destroy(ip6_dst_ops_template.kmem_cachep);
6798 }
6799