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, int how);
94 static int		 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->rt6i_uncached_list = ul;
143 
144 	spin_lock_bh(&ul->lock);
145 	list_add_tail(&rt->rt6i_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->rt6i_uncached)) {
152 		struct uncached_list *ul = rt->rt6i_uncached_list;
153 
154 		spin_lock_bh(&ul->lock);
155 		list_del_init(&rt->rt6i_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, rt6i_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 				dev_replace_track(rt_dev, blackhole_netdev,
186 						  &rt->dst.dev_tracker,
187 						  GFP_ATOMIC);
188 				handled = true;
189 			}
190 			if (handled)
191 				list_move(&rt->rt6i_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 		.__refcnt	= ATOMIC_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 		.__refcnt	= ATOMIC_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 		.__refcnt	= ATOMIC_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 	INIT_LIST_HEAD(&rt->rt6i_uncached);
338 }
339 
340 /* allocate dst with ip6_dst_ops */
ip6_dst_alloc(struct net * net,struct net_device * dev,int flags)341 struct rt6_info *ip6_dst_alloc(struct net *net, struct net_device *dev,
342 			       int flags)
343 {
344 	struct rt6_info *rt = dst_alloc(&net->ipv6.ip6_dst_ops, dev,
345 					1, DST_OBSOLETE_FORCE_CHK, flags);
346 
347 	if (rt) {
348 		rt6_info_init(rt);
349 		atomic_inc(&net->ipv6.rt6_stats->fib_rt_alloc);
350 	}
351 
352 	return rt;
353 }
354 EXPORT_SYMBOL(ip6_dst_alloc);
355 
ip6_dst_destroy(struct dst_entry * dst)356 static void ip6_dst_destroy(struct dst_entry *dst)
357 {
358 	struct rt6_info *rt = (struct rt6_info *)dst;
359 	struct fib6_info *from;
360 	struct inet6_dev *idev;
361 
362 	ip_dst_metrics_put(dst);
363 	rt6_uncached_list_del(rt);
364 
365 	idev = rt->rt6i_idev;
366 	if (idev) {
367 		rt->rt6i_idev = NULL;
368 		in6_dev_put(idev);
369 	}
370 
371 	from = xchg((__force struct fib6_info **)&rt->from, NULL);
372 	fib6_info_release(from);
373 }
374 
ip6_dst_ifdown(struct dst_entry * dst,struct net_device * dev,int how)375 static void ip6_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
376 			   int how)
377 {
378 	struct rt6_info *rt = (struct rt6_info *)dst;
379 	struct inet6_dev *idev = rt->rt6i_idev;
380 
381 	if (idev && idev->dev != blackhole_netdev) {
382 		struct inet6_dev *blackhole_idev = in6_dev_get(blackhole_netdev);
383 
384 		if (blackhole_idev) {
385 			rt->rt6i_idev = blackhole_idev;
386 			in6_dev_put(idev);
387 		}
388 	}
389 }
390 
__rt6_check_expired(const struct rt6_info * rt)391 static bool __rt6_check_expired(const struct rt6_info *rt)
392 {
393 	if (rt->rt6i_flags & RTF_EXPIRES)
394 		return time_after(jiffies, rt->dst.expires);
395 	else
396 		return false;
397 }
398 
rt6_check_expired(const struct rt6_info * rt)399 static bool rt6_check_expired(const struct rt6_info *rt)
400 {
401 	struct fib6_info *from;
402 
403 	from = rcu_dereference(rt->from);
404 
405 	if (rt->rt6i_flags & RTF_EXPIRES) {
406 		if (time_after(jiffies, rt->dst.expires))
407 			return true;
408 	} else if (from) {
409 		return rt->dst.obsolete != DST_OBSOLETE_FORCE_CHK ||
410 			fib6_check_expired(from);
411 	}
412 	return false;
413 }
414 
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)415 void fib6_select_path(const struct net *net, struct fib6_result *res,
416 		      struct flowi6 *fl6, int oif, bool have_oif_match,
417 		      const struct sk_buff *skb, int strict)
418 {
419 	struct fib6_info *sibling, *next_sibling;
420 	struct fib6_info *match = res->f6i;
421 
422 	if (!match->nh && (!match->fib6_nsiblings || have_oif_match))
423 		goto out;
424 
425 	if (match->nh && have_oif_match && res->nh)
426 		return;
427 
428 	/* We might have already computed the hash for ICMPv6 errors. In such
429 	 * case it will always be non-zero. Otherwise now is the time to do it.
430 	 */
431 	if (!fl6->mp_hash &&
432 	    (!match->nh || nexthop_is_multipath(match->nh)))
433 		fl6->mp_hash = rt6_multipath_hash(net, fl6, skb, NULL);
434 
435 	if (unlikely(match->nh)) {
436 		nexthop_path_fib6_result(res, fl6->mp_hash);
437 		return;
438 	}
439 
440 	if (fl6->mp_hash <= atomic_read(&match->fib6_nh->fib_nh_upper_bound))
441 		goto out;
442 
443 	list_for_each_entry_safe(sibling, next_sibling, &match->fib6_siblings,
444 				 fib6_siblings) {
445 		const struct fib6_nh *nh = sibling->fib6_nh;
446 		int nh_upper_bound;
447 
448 		nh_upper_bound = atomic_read(&nh->fib_nh_upper_bound);
449 		if (fl6->mp_hash > nh_upper_bound)
450 			continue;
451 		if (rt6_score_route(nh, sibling->fib6_flags, oif, strict) < 0)
452 			break;
453 		match = sibling;
454 		break;
455 	}
456 
457 out:
458 	res->f6i = match;
459 	res->nh = match->fib6_nh;
460 }
461 
462 /*
463  *	Route lookup. rcu_read_lock() should be held.
464  */
465 
__rt6_device_match(struct net * net,const struct fib6_nh * nh,const struct in6_addr * saddr,int oif,int flags)466 static bool __rt6_device_match(struct net *net, const struct fib6_nh *nh,
467 			       const struct in6_addr *saddr, int oif, int flags)
468 {
469 	const struct net_device *dev;
470 
471 	if (nh->fib_nh_flags & RTNH_F_DEAD)
472 		return false;
473 
474 	dev = nh->fib_nh_dev;
475 	if (oif) {
476 		if (dev->ifindex == oif)
477 			return true;
478 	} else {
479 		if (ipv6_chk_addr(net, saddr, dev,
480 				  flags & RT6_LOOKUP_F_IFACE))
481 			return true;
482 	}
483 
484 	return false;
485 }
486 
487 struct fib6_nh_dm_arg {
488 	struct net		*net;
489 	const struct in6_addr	*saddr;
490 	int			oif;
491 	int			flags;
492 	struct fib6_nh		*nh;
493 };
494 
__rt6_nh_dev_match(struct fib6_nh * nh,void * _arg)495 static int __rt6_nh_dev_match(struct fib6_nh *nh, void *_arg)
496 {
497 	struct fib6_nh_dm_arg *arg = _arg;
498 
499 	arg->nh = nh;
500 	return __rt6_device_match(arg->net, nh, arg->saddr, arg->oif,
501 				  arg->flags);
502 }
503 
504 /* 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)505 static struct fib6_nh *rt6_nh_dev_match(struct net *net, struct nexthop *nh,
506 					struct fib6_result *res,
507 					const struct in6_addr *saddr,
508 					int oif, int flags)
509 {
510 	struct fib6_nh_dm_arg arg = {
511 		.net   = net,
512 		.saddr = saddr,
513 		.oif   = oif,
514 		.flags = flags,
515 	};
516 
517 	if (nexthop_is_blackhole(nh))
518 		return NULL;
519 
520 	if (nexthop_for_each_fib6_nh(nh, __rt6_nh_dev_match, &arg))
521 		return arg.nh;
522 
523 	return NULL;
524 }
525 
rt6_device_match(struct net * net,struct fib6_result * res,const struct in6_addr * saddr,int oif,int flags)526 static void rt6_device_match(struct net *net, struct fib6_result *res,
527 			     const struct in6_addr *saddr, int oif, int flags)
528 {
529 	struct fib6_info *f6i = res->f6i;
530 	struct fib6_info *spf6i;
531 	struct fib6_nh *nh;
532 
533 	if (!oif && ipv6_addr_any(saddr)) {
534 		if (unlikely(f6i->nh)) {
535 			nh = nexthop_fib6_nh(f6i->nh);
536 			if (nexthop_is_blackhole(f6i->nh))
537 				goto out_blackhole;
538 		} else {
539 			nh = f6i->fib6_nh;
540 		}
541 		if (!(nh->fib_nh_flags & RTNH_F_DEAD))
542 			goto out;
543 	}
544 
545 	for (spf6i = f6i; spf6i; spf6i = rcu_dereference(spf6i->fib6_next)) {
546 		bool matched = false;
547 
548 		if (unlikely(spf6i->nh)) {
549 			nh = rt6_nh_dev_match(net, spf6i->nh, res, saddr,
550 					      oif, flags);
551 			if (nh)
552 				matched = true;
553 		} else {
554 			nh = spf6i->fib6_nh;
555 			if (__rt6_device_match(net, nh, saddr, oif, flags))
556 				matched = true;
557 		}
558 		if (matched) {
559 			res->f6i = spf6i;
560 			goto out;
561 		}
562 	}
563 
564 	if (oif && flags & RT6_LOOKUP_F_IFACE) {
565 		res->f6i = net->ipv6.fib6_null_entry;
566 		nh = res->f6i->fib6_nh;
567 		goto out;
568 	}
569 
570 	if (unlikely(f6i->nh)) {
571 		nh = nexthop_fib6_nh(f6i->nh);
572 		if (nexthop_is_blackhole(f6i->nh))
573 			goto out_blackhole;
574 	} else {
575 		nh = f6i->fib6_nh;
576 	}
577 
578 	if (nh->fib_nh_flags & RTNH_F_DEAD) {
579 		res->f6i = net->ipv6.fib6_null_entry;
580 		nh = res->f6i->fib6_nh;
581 	}
582 out:
583 	res->nh = nh;
584 	res->fib6_type = res->f6i->fib6_type;
585 	res->fib6_flags = res->f6i->fib6_flags;
586 	return;
587 
588 out_blackhole:
589 	res->fib6_flags |= RTF_REJECT;
590 	res->fib6_type = RTN_BLACKHOLE;
591 	res->nh = nh;
592 }
593 
594 #ifdef CONFIG_IPV6_ROUTER_PREF
595 struct __rt6_probe_work {
596 	struct work_struct work;
597 	struct in6_addr target;
598 	struct net_device *dev;
599 	netdevice_tracker dev_tracker;
600 };
601 
rt6_probe_deferred(struct work_struct * w)602 static void rt6_probe_deferred(struct work_struct *w)
603 {
604 	struct in6_addr mcaddr;
605 	struct __rt6_probe_work *work =
606 		container_of(w, struct __rt6_probe_work, work);
607 
608 	addrconf_addr_solict_mult(&work->target, &mcaddr);
609 	ndisc_send_ns(work->dev, &work->target, &mcaddr, NULL, 0);
610 	dev_put_track(work->dev, &work->dev_tracker);
611 	kfree(work);
612 }
613 
rt6_probe(struct fib6_nh * fib6_nh)614 static void rt6_probe(struct fib6_nh *fib6_nh)
615 {
616 	struct __rt6_probe_work *work = NULL;
617 	const struct in6_addr *nh_gw;
618 	unsigned long last_probe;
619 	struct neighbour *neigh;
620 	struct net_device *dev;
621 	struct inet6_dev *idev;
622 
623 	/*
624 	 * Okay, this does not seem to be appropriate
625 	 * for now, however, we need to check if it
626 	 * is really so; aka Router Reachability Probing.
627 	 *
628 	 * Router Reachability Probe MUST be rate-limited
629 	 * to no more than one per minute.
630 	 */
631 	if (!fib6_nh->fib_nh_gw_family)
632 		return;
633 
634 	nh_gw = &fib6_nh->fib_nh_gw6;
635 	dev = fib6_nh->fib_nh_dev;
636 	rcu_read_lock_bh();
637 	last_probe = READ_ONCE(fib6_nh->last_probe);
638 	idev = __in6_dev_get(dev);
639 	neigh = __ipv6_neigh_lookup_noref(dev, nh_gw);
640 	if (neigh) {
641 		if (neigh->nud_state & NUD_VALID)
642 			goto out;
643 
644 		write_lock(&neigh->lock);
645 		if (!(neigh->nud_state & NUD_VALID) &&
646 		    time_after(jiffies,
647 			       neigh->updated + idev->cnf.rtr_probe_interval)) {
648 			work = kmalloc(sizeof(*work), GFP_ATOMIC);
649 			if (work)
650 				__neigh_set_probe_once(neigh);
651 		}
652 		write_unlock(&neigh->lock);
653 	} else if (time_after(jiffies, last_probe +
654 				       idev->cnf.rtr_probe_interval)) {
655 		work = kmalloc(sizeof(*work), GFP_ATOMIC);
656 	}
657 
658 	if (!work || cmpxchg(&fib6_nh->last_probe,
659 			     last_probe, jiffies) != last_probe) {
660 		kfree(work);
661 	} else {
662 		INIT_WORK(&work->work, rt6_probe_deferred);
663 		work->target = *nh_gw;
664 		dev_hold_track(dev, &work->dev_tracker, GFP_ATOMIC);
665 		work->dev = dev;
666 		schedule_work(&work->work);
667 	}
668 
669 out:
670 	rcu_read_unlock_bh();
671 }
672 #else
rt6_probe(struct fib6_nh * fib6_nh)673 static inline void rt6_probe(struct fib6_nh *fib6_nh)
674 {
675 }
676 #endif
677 
678 /*
679  * Default Router Selection (RFC 2461 6.3.6)
680  */
rt6_check_neigh(const struct fib6_nh * fib6_nh)681 static enum rt6_nud_state rt6_check_neigh(const struct fib6_nh *fib6_nh)
682 {
683 	enum rt6_nud_state ret = RT6_NUD_FAIL_HARD;
684 	struct neighbour *neigh;
685 
686 	rcu_read_lock_bh();
687 	neigh = __ipv6_neigh_lookup_noref(fib6_nh->fib_nh_dev,
688 					  &fib6_nh->fib_nh_gw6);
689 	if (neigh) {
690 		read_lock(&neigh->lock);
691 		if (neigh->nud_state & NUD_VALID)
692 			ret = RT6_NUD_SUCCEED;
693 #ifdef CONFIG_IPV6_ROUTER_PREF
694 		else if (!(neigh->nud_state & NUD_FAILED))
695 			ret = RT6_NUD_SUCCEED;
696 		else
697 			ret = RT6_NUD_FAIL_PROBE;
698 #endif
699 		read_unlock(&neigh->lock);
700 	} else {
701 		ret = IS_ENABLED(CONFIG_IPV6_ROUTER_PREF) ?
702 		      RT6_NUD_SUCCEED : RT6_NUD_FAIL_DO_RR;
703 	}
704 	rcu_read_unlock_bh();
705 
706 	return ret;
707 }
708 
rt6_score_route(const struct fib6_nh * nh,u32 fib6_flags,int oif,int strict)709 static int rt6_score_route(const struct fib6_nh *nh, u32 fib6_flags, int oif,
710 			   int strict)
711 {
712 	int m = 0;
713 
714 	if (!oif || nh->fib_nh_dev->ifindex == oif)
715 		m = 2;
716 
717 	if (!m && (strict & RT6_LOOKUP_F_IFACE))
718 		return RT6_NUD_FAIL_HARD;
719 #ifdef CONFIG_IPV6_ROUTER_PREF
720 	m |= IPV6_DECODE_PREF(IPV6_EXTRACT_PREF(fib6_flags)) << 2;
721 #endif
722 	if ((strict & RT6_LOOKUP_F_REACHABLE) &&
723 	    !(fib6_flags & RTF_NONEXTHOP) && nh->fib_nh_gw_family) {
724 		int n = rt6_check_neigh(nh);
725 		if (n < 0)
726 			return n;
727 	}
728 	return m;
729 }
730 
find_match(struct fib6_nh * nh,u32 fib6_flags,int oif,int strict,int * mpri,bool * do_rr)731 static bool find_match(struct fib6_nh *nh, u32 fib6_flags,
732 		       int oif, int strict, int *mpri, bool *do_rr)
733 {
734 	bool match_do_rr = false;
735 	bool rc = false;
736 	int m;
737 
738 	if (nh->fib_nh_flags & RTNH_F_DEAD)
739 		goto out;
740 
741 	if (ip6_ignore_linkdown(nh->fib_nh_dev) &&
742 	    nh->fib_nh_flags & RTNH_F_LINKDOWN &&
743 	    !(strict & RT6_LOOKUP_F_IGNORE_LINKSTATE))
744 		goto out;
745 
746 	m = rt6_score_route(nh, fib6_flags, oif, strict);
747 	if (m == RT6_NUD_FAIL_DO_RR) {
748 		match_do_rr = true;
749 		m = 0; /* lowest valid score */
750 	} else if (m == RT6_NUD_FAIL_HARD) {
751 		goto out;
752 	}
753 
754 	if (strict & RT6_LOOKUP_F_REACHABLE)
755 		rt6_probe(nh);
756 
757 	/* note that m can be RT6_NUD_FAIL_PROBE at this point */
758 	if (m > *mpri) {
759 		*do_rr = match_do_rr;
760 		*mpri = m;
761 		rc = true;
762 	}
763 out:
764 	return rc;
765 }
766 
767 struct fib6_nh_frl_arg {
768 	u32		flags;
769 	int		oif;
770 	int		strict;
771 	int		*mpri;
772 	bool		*do_rr;
773 	struct fib6_nh	*nh;
774 };
775 
rt6_nh_find_match(struct fib6_nh * nh,void * _arg)776 static int rt6_nh_find_match(struct fib6_nh *nh, void *_arg)
777 {
778 	struct fib6_nh_frl_arg *arg = _arg;
779 
780 	arg->nh = nh;
781 	return find_match(nh, arg->flags, arg->oif, arg->strict,
782 			  arg->mpri, arg->do_rr);
783 }
784 
__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)785 static void __find_rr_leaf(struct fib6_info *f6i_start,
786 			   struct fib6_info *nomatch, u32 metric,
787 			   struct fib6_result *res, struct fib6_info **cont,
788 			   int oif, int strict, bool *do_rr, int *mpri)
789 {
790 	struct fib6_info *f6i;
791 
792 	for (f6i = f6i_start;
793 	     f6i && f6i != nomatch;
794 	     f6i = rcu_dereference(f6i->fib6_next)) {
795 		bool matched = false;
796 		struct fib6_nh *nh;
797 
798 		if (cont && f6i->fib6_metric != metric) {
799 			*cont = f6i;
800 			return;
801 		}
802 
803 		if (fib6_check_expired(f6i))
804 			continue;
805 
806 		if (unlikely(f6i->nh)) {
807 			struct fib6_nh_frl_arg arg = {
808 				.flags  = f6i->fib6_flags,
809 				.oif    = oif,
810 				.strict = strict,
811 				.mpri   = mpri,
812 				.do_rr  = do_rr
813 			};
814 
815 			if (nexthop_is_blackhole(f6i->nh)) {
816 				res->fib6_flags = RTF_REJECT;
817 				res->fib6_type = RTN_BLACKHOLE;
818 				res->f6i = f6i;
819 				res->nh = nexthop_fib6_nh(f6i->nh);
820 				return;
821 			}
822 			if (nexthop_for_each_fib6_nh(f6i->nh, rt6_nh_find_match,
823 						     &arg)) {
824 				matched = true;
825 				nh = arg.nh;
826 			}
827 		} else {
828 			nh = f6i->fib6_nh;
829 			if (find_match(nh, f6i->fib6_flags, oif, strict,
830 				       mpri, do_rr))
831 				matched = true;
832 		}
833 		if (matched) {
834 			res->f6i = f6i;
835 			res->nh = nh;
836 			res->fib6_flags = f6i->fib6_flags;
837 			res->fib6_type = f6i->fib6_type;
838 		}
839 	}
840 }
841 
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)842 static void find_rr_leaf(struct fib6_node *fn, struct fib6_info *leaf,
843 			 struct fib6_info *rr_head, int oif, int strict,
844 			 bool *do_rr, struct fib6_result *res)
845 {
846 	u32 metric = rr_head->fib6_metric;
847 	struct fib6_info *cont = NULL;
848 	int mpri = -1;
849 
850 	__find_rr_leaf(rr_head, NULL, metric, res, &cont,
851 		       oif, strict, do_rr, &mpri);
852 
853 	__find_rr_leaf(leaf, rr_head, metric, res, &cont,
854 		       oif, strict, do_rr, &mpri);
855 
856 	if (res->f6i || !cont)
857 		return;
858 
859 	__find_rr_leaf(cont, NULL, metric, res, NULL,
860 		       oif, strict, do_rr, &mpri);
861 }
862 
rt6_select(struct net * net,struct fib6_node * fn,int oif,struct fib6_result * res,int strict)863 static void rt6_select(struct net *net, struct fib6_node *fn, int oif,
864 		       struct fib6_result *res, int strict)
865 {
866 	struct fib6_info *leaf = rcu_dereference(fn->leaf);
867 	struct fib6_info *rt0;
868 	bool do_rr = false;
869 	int key_plen;
870 
871 	/* make sure this function or its helpers sets f6i */
872 	res->f6i = NULL;
873 
874 	if (!leaf || leaf == net->ipv6.fib6_null_entry)
875 		goto out;
876 
877 	rt0 = rcu_dereference(fn->rr_ptr);
878 	if (!rt0)
879 		rt0 = leaf;
880 
881 	/* Double check to make sure fn is not an intermediate node
882 	 * and fn->leaf does not points to its child's leaf
883 	 * (This might happen if all routes under fn are deleted from
884 	 * the tree and fib6_repair_tree() is called on the node.)
885 	 */
886 	key_plen = rt0->fib6_dst.plen;
887 #ifdef CONFIG_IPV6_SUBTREES
888 	if (rt0->fib6_src.plen)
889 		key_plen = rt0->fib6_src.plen;
890 #endif
891 	if (fn->fn_bit != key_plen)
892 		goto out;
893 
894 	find_rr_leaf(fn, leaf, rt0, oif, strict, &do_rr, res);
895 	if (do_rr) {
896 		struct fib6_info *next = rcu_dereference(rt0->fib6_next);
897 
898 		/* no entries matched; do round-robin */
899 		if (!next || next->fib6_metric != rt0->fib6_metric)
900 			next = leaf;
901 
902 		if (next != rt0) {
903 			spin_lock_bh(&leaf->fib6_table->tb6_lock);
904 			/* make sure next is not being deleted from the tree */
905 			if (next->fib6_node)
906 				rcu_assign_pointer(fn->rr_ptr, next);
907 			spin_unlock_bh(&leaf->fib6_table->tb6_lock);
908 		}
909 	}
910 
911 out:
912 	if (!res->f6i) {
913 		res->f6i = net->ipv6.fib6_null_entry;
914 		res->nh = res->f6i->fib6_nh;
915 		res->fib6_flags = res->f6i->fib6_flags;
916 		res->fib6_type = res->f6i->fib6_type;
917 	}
918 }
919 
rt6_is_gw_or_nonexthop(const struct fib6_result * res)920 static bool rt6_is_gw_or_nonexthop(const struct fib6_result *res)
921 {
922 	return (res->f6i->fib6_flags & RTF_NONEXTHOP) ||
923 	       res->nh->fib_nh_gw_family;
924 }
925 
926 #ifdef CONFIG_IPV6_ROUTE_INFO
rt6_route_rcv(struct net_device * dev,u8 * opt,int len,const struct in6_addr * gwaddr)927 int rt6_route_rcv(struct net_device *dev, u8 *opt, int len,
928 		  const struct in6_addr *gwaddr)
929 {
930 	struct net *net = dev_net(dev);
931 	struct route_info *rinfo = (struct route_info *) opt;
932 	struct in6_addr prefix_buf, *prefix;
933 	unsigned int pref;
934 	unsigned long lifetime;
935 	struct fib6_info *rt;
936 
937 	if (len < sizeof(struct route_info)) {
938 		return -EINVAL;
939 	}
940 
941 	/* Sanity check for prefix_len and length */
942 	if (rinfo->length > 3) {
943 		return -EINVAL;
944 	} else if (rinfo->prefix_len > 128) {
945 		return -EINVAL;
946 	} else if (rinfo->prefix_len > 64) {
947 		if (rinfo->length < 2) {
948 			return -EINVAL;
949 		}
950 	} else if (rinfo->prefix_len > 0) {
951 		if (rinfo->length < 1) {
952 			return -EINVAL;
953 		}
954 	}
955 
956 	pref = rinfo->route_pref;
957 	if (pref == ICMPV6_ROUTER_PREF_INVALID)
958 		return -EINVAL;
959 
960 	lifetime = addrconf_timeout_fixup(ntohl(rinfo->lifetime), HZ);
961 
962 	if (rinfo->length == 3)
963 		prefix = (struct in6_addr *)rinfo->prefix;
964 	else {
965 		/* this function is safe */
966 		ipv6_addr_prefix(&prefix_buf,
967 				 (struct in6_addr *)rinfo->prefix,
968 				 rinfo->prefix_len);
969 		prefix = &prefix_buf;
970 	}
971 
972 	if (rinfo->prefix_len == 0)
973 		rt = rt6_get_dflt_router(net, gwaddr, dev);
974 	else
975 		rt = rt6_get_route_info(net, prefix, rinfo->prefix_len,
976 					gwaddr, dev);
977 
978 	if (rt && !lifetime) {
979 		ip6_del_rt(net, rt, false);
980 		rt = NULL;
981 	}
982 
983 	if (!rt && lifetime)
984 		rt = rt6_add_route_info(net, prefix, rinfo->prefix_len, gwaddr,
985 					dev, pref);
986 	else if (rt)
987 		rt->fib6_flags = RTF_ROUTEINFO |
988 				 (rt->fib6_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
989 
990 	if (rt) {
991 		if (!addrconf_finite_timeout(lifetime))
992 			fib6_clean_expires(rt);
993 		else
994 			fib6_set_expires(rt, jiffies + HZ * lifetime);
995 
996 		fib6_info_release(rt);
997 	}
998 	return 0;
999 }
1000 #endif
1001 
1002 /*
1003  *	Misc support functions
1004  */
1005 
1006 /* called with rcu_lock held */
ip6_rt_get_dev_rcu(const struct fib6_result * res)1007 static struct net_device *ip6_rt_get_dev_rcu(const struct fib6_result *res)
1008 {
1009 	struct net_device *dev = res->nh->fib_nh_dev;
1010 
1011 	if (res->fib6_flags & (RTF_LOCAL | RTF_ANYCAST)) {
1012 		/* for copies of local routes, dst->dev needs to be the
1013 		 * device if it is a master device, the master device if
1014 		 * device is enslaved, and the loopback as the default
1015 		 */
1016 		if (netif_is_l3_slave(dev) &&
1017 		    !rt6_need_strict(&res->f6i->fib6_dst.addr))
1018 			dev = l3mdev_master_dev_rcu(dev);
1019 		else if (!netif_is_l3_master(dev))
1020 			dev = dev_net(dev)->loopback_dev;
1021 		/* last case is netif_is_l3_master(dev) is true in which
1022 		 * case we want dev returned to be dev
1023 		 */
1024 	}
1025 
1026 	return dev;
1027 }
1028 
1029 static const int fib6_prop[RTN_MAX + 1] = {
1030 	[RTN_UNSPEC]	= 0,
1031 	[RTN_UNICAST]	= 0,
1032 	[RTN_LOCAL]	= 0,
1033 	[RTN_BROADCAST]	= 0,
1034 	[RTN_ANYCAST]	= 0,
1035 	[RTN_MULTICAST]	= 0,
1036 	[RTN_BLACKHOLE]	= -EINVAL,
1037 	[RTN_UNREACHABLE] = -EHOSTUNREACH,
1038 	[RTN_PROHIBIT]	= -EACCES,
1039 	[RTN_THROW]	= -EAGAIN,
1040 	[RTN_NAT]	= -EINVAL,
1041 	[RTN_XRESOLVE]	= -EINVAL,
1042 };
1043 
ip6_rt_type_to_error(u8 fib6_type)1044 static int ip6_rt_type_to_error(u8 fib6_type)
1045 {
1046 	return fib6_prop[fib6_type];
1047 }
1048 
fib6_info_dst_flags(struct fib6_info * rt)1049 static unsigned short fib6_info_dst_flags(struct fib6_info *rt)
1050 {
1051 	unsigned short flags = 0;
1052 
1053 	if (rt->dst_nocount)
1054 		flags |= DST_NOCOUNT;
1055 	if (rt->dst_nopolicy)
1056 		flags |= DST_NOPOLICY;
1057 
1058 	return flags;
1059 }
1060 
ip6_rt_init_dst_reject(struct rt6_info * rt,u8 fib6_type)1061 static void ip6_rt_init_dst_reject(struct rt6_info *rt, u8 fib6_type)
1062 {
1063 	rt->dst.error = ip6_rt_type_to_error(fib6_type);
1064 
1065 	switch (fib6_type) {
1066 	case RTN_BLACKHOLE:
1067 		rt->dst.output = dst_discard_out;
1068 		rt->dst.input = dst_discard;
1069 		break;
1070 	case RTN_PROHIBIT:
1071 		rt->dst.output = ip6_pkt_prohibit_out;
1072 		rt->dst.input = ip6_pkt_prohibit;
1073 		break;
1074 	case RTN_THROW:
1075 	case RTN_UNREACHABLE:
1076 	default:
1077 		rt->dst.output = ip6_pkt_discard_out;
1078 		rt->dst.input = ip6_pkt_discard;
1079 		break;
1080 	}
1081 }
1082 
ip6_rt_init_dst(struct rt6_info * rt,const struct fib6_result * res)1083 static void ip6_rt_init_dst(struct rt6_info *rt, const struct fib6_result *res)
1084 {
1085 	struct fib6_info *f6i = res->f6i;
1086 
1087 	if (res->fib6_flags & RTF_REJECT) {
1088 		ip6_rt_init_dst_reject(rt, res->fib6_type);
1089 		return;
1090 	}
1091 
1092 	rt->dst.error = 0;
1093 	rt->dst.output = ip6_output;
1094 
1095 	if (res->fib6_type == RTN_LOCAL || res->fib6_type == RTN_ANYCAST) {
1096 		rt->dst.input = ip6_input;
1097 	} else if (ipv6_addr_type(&f6i->fib6_dst.addr) & IPV6_ADDR_MULTICAST) {
1098 		rt->dst.input = ip6_mc_input;
1099 	} else {
1100 		rt->dst.input = ip6_forward;
1101 	}
1102 
1103 	if (res->nh->fib_nh_lws) {
1104 		rt->dst.lwtstate = lwtstate_get(res->nh->fib_nh_lws);
1105 		lwtunnel_set_redirect(&rt->dst);
1106 	}
1107 
1108 	rt->dst.lastuse = jiffies;
1109 }
1110 
1111 /* Caller must already hold reference to @from */
rt6_set_from(struct rt6_info * rt,struct fib6_info * from)1112 static void rt6_set_from(struct rt6_info *rt, struct fib6_info *from)
1113 {
1114 	rt->rt6i_flags &= ~RTF_EXPIRES;
1115 	rcu_assign_pointer(rt->from, from);
1116 	ip_dst_init_metrics(&rt->dst, from->fib6_metrics);
1117 }
1118 
1119 /* Caller must already hold reference to f6i in result */
ip6_rt_copy_init(struct rt6_info * rt,const struct fib6_result * res)1120 static void ip6_rt_copy_init(struct rt6_info *rt, const struct fib6_result *res)
1121 {
1122 	const struct fib6_nh *nh = res->nh;
1123 	const struct net_device *dev = nh->fib_nh_dev;
1124 	struct fib6_info *f6i = res->f6i;
1125 
1126 	ip6_rt_init_dst(rt, res);
1127 
1128 	rt->rt6i_dst = f6i->fib6_dst;
1129 	rt->rt6i_idev = dev ? in6_dev_get(dev) : NULL;
1130 	rt->rt6i_flags = res->fib6_flags;
1131 	if (nh->fib_nh_gw_family) {
1132 		rt->rt6i_gateway = nh->fib_nh_gw6;
1133 		rt->rt6i_flags |= RTF_GATEWAY;
1134 	}
1135 	rt6_set_from(rt, f6i);
1136 #ifdef CONFIG_IPV6_SUBTREES
1137 	rt->rt6i_src = f6i->fib6_src;
1138 #endif
1139 }
1140 
fib6_backtrack(struct fib6_node * fn,struct in6_addr * saddr)1141 static struct fib6_node* fib6_backtrack(struct fib6_node *fn,
1142 					struct in6_addr *saddr)
1143 {
1144 	struct fib6_node *pn, *sn;
1145 	while (1) {
1146 		if (fn->fn_flags & RTN_TL_ROOT)
1147 			return NULL;
1148 		pn = rcu_dereference(fn->parent);
1149 		sn = FIB6_SUBTREE(pn);
1150 		if (sn && sn != fn)
1151 			fn = fib6_node_lookup(sn, NULL, saddr);
1152 		else
1153 			fn = pn;
1154 		if (fn->fn_flags & RTN_RTINFO)
1155 			return fn;
1156 	}
1157 }
1158 
ip6_hold_safe(struct net * net,struct rt6_info ** prt)1159 static bool ip6_hold_safe(struct net *net, struct rt6_info **prt)
1160 {
1161 	struct rt6_info *rt = *prt;
1162 
1163 	if (dst_hold_safe(&rt->dst))
1164 		return true;
1165 	if (net) {
1166 		rt = net->ipv6.ip6_null_entry;
1167 		dst_hold(&rt->dst);
1168 	} else {
1169 		rt = NULL;
1170 	}
1171 	*prt = rt;
1172 	return false;
1173 }
1174 
1175 /* called with rcu_lock held */
ip6_create_rt_rcu(const struct fib6_result * res)1176 static struct rt6_info *ip6_create_rt_rcu(const struct fib6_result *res)
1177 {
1178 	struct net_device *dev = res->nh->fib_nh_dev;
1179 	struct fib6_info *f6i = res->f6i;
1180 	unsigned short flags;
1181 	struct rt6_info *nrt;
1182 
1183 	if (!fib6_info_hold_safe(f6i))
1184 		goto fallback;
1185 
1186 	flags = fib6_info_dst_flags(f6i);
1187 	nrt = ip6_dst_alloc(dev_net(dev), dev, flags);
1188 	if (!nrt) {
1189 		fib6_info_release(f6i);
1190 		goto fallback;
1191 	}
1192 
1193 	ip6_rt_copy_init(nrt, res);
1194 	return nrt;
1195 
1196 fallback:
1197 	nrt = dev_net(dev)->ipv6.ip6_null_entry;
1198 	dst_hold(&nrt->dst);
1199 	return nrt;
1200 }
1201 
ip6_pol_route_lookup(struct net * net,struct fib6_table * table,struct flowi6 * fl6,const struct sk_buff * skb,int flags)1202 INDIRECT_CALLABLE_SCOPE struct rt6_info *ip6_pol_route_lookup(struct net *net,
1203 					     struct fib6_table *table,
1204 					     struct flowi6 *fl6,
1205 					     const struct sk_buff *skb,
1206 					     int flags)
1207 {
1208 	struct fib6_result res = {};
1209 	struct fib6_node *fn;
1210 	struct rt6_info *rt;
1211 
1212 	rcu_read_lock();
1213 	fn = fib6_node_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr);
1214 restart:
1215 	res.f6i = rcu_dereference(fn->leaf);
1216 	if (!res.f6i)
1217 		res.f6i = net->ipv6.fib6_null_entry;
1218 	else
1219 		rt6_device_match(net, &res, &fl6->saddr, fl6->flowi6_oif,
1220 				 flags);
1221 
1222 	if (res.f6i == net->ipv6.fib6_null_entry) {
1223 		fn = fib6_backtrack(fn, &fl6->saddr);
1224 		if (fn)
1225 			goto restart;
1226 
1227 		rt = net->ipv6.ip6_null_entry;
1228 		dst_hold(&rt->dst);
1229 		goto out;
1230 	} else if (res.fib6_flags & RTF_REJECT) {
1231 		goto do_create;
1232 	}
1233 
1234 	fib6_select_path(net, &res, fl6, fl6->flowi6_oif,
1235 			 fl6->flowi6_oif != 0, skb, flags);
1236 
1237 	/* Search through exception table */
1238 	rt = rt6_find_cached_rt(&res, &fl6->daddr, &fl6->saddr);
1239 	if (rt) {
1240 		if (ip6_hold_safe(net, &rt))
1241 			dst_use_noref(&rt->dst, jiffies);
1242 	} else {
1243 do_create:
1244 		rt = ip6_create_rt_rcu(&res);
1245 	}
1246 
1247 out:
1248 	trace_fib6_table_lookup(net, &res, table, fl6);
1249 
1250 	rcu_read_unlock();
1251 
1252 	return rt;
1253 }
1254 
ip6_route_lookup(struct net * net,struct flowi6 * fl6,const struct sk_buff * skb,int flags)1255 struct dst_entry *ip6_route_lookup(struct net *net, struct flowi6 *fl6,
1256 				   const struct sk_buff *skb, int flags)
1257 {
1258 	return fib6_rule_lookup(net, fl6, skb, flags, ip6_pol_route_lookup);
1259 }
1260 EXPORT_SYMBOL_GPL(ip6_route_lookup);
1261 
rt6_lookup(struct net * net,const struct in6_addr * daddr,const struct in6_addr * saddr,int oif,const struct sk_buff * skb,int strict)1262 struct rt6_info *rt6_lookup(struct net *net, const struct in6_addr *daddr,
1263 			    const struct in6_addr *saddr, int oif,
1264 			    const struct sk_buff *skb, int strict)
1265 {
1266 	struct flowi6 fl6 = {
1267 		.flowi6_oif = oif,
1268 		.daddr = *daddr,
1269 	};
1270 	struct dst_entry *dst;
1271 	int flags = strict ? RT6_LOOKUP_F_IFACE : 0;
1272 
1273 	if (saddr) {
1274 		memcpy(&fl6.saddr, saddr, sizeof(*saddr));
1275 		flags |= RT6_LOOKUP_F_HAS_SADDR;
1276 	}
1277 
1278 	dst = fib6_rule_lookup(net, &fl6, skb, flags, ip6_pol_route_lookup);
1279 	if (dst->error == 0)
1280 		return (struct rt6_info *) dst;
1281 
1282 	dst_release(dst);
1283 
1284 	return NULL;
1285 }
1286 EXPORT_SYMBOL(rt6_lookup);
1287 
1288 /* ip6_ins_rt is called with FREE table->tb6_lock.
1289  * It takes new route entry, the addition fails by any reason the
1290  * route is released.
1291  * Caller must hold dst before calling it.
1292  */
1293 
__ip6_ins_rt(struct fib6_info * rt,struct nl_info * info,struct netlink_ext_ack * extack)1294 static int __ip6_ins_rt(struct fib6_info *rt, struct nl_info *info,
1295 			struct netlink_ext_ack *extack)
1296 {
1297 	int err;
1298 	struct fib6_table *table;
1299 
1300 	table = rt->fib6_table;
1301 	spin_lock_bh(&table->tb6_lock);
1302 	err = fib6_add(&table->tb6_root, rt, info, extack);
1303 	spin_unlock_bh(&table->tb6_lock);
1304 
1305 	return err;
1306 }
1307 
ip6_ins_rt(struct net * net,struct fib6_info * rt)1308 int ip6_ins_rt(struct net *net, struct fib6_info *rt)
1309 {
1310 	struct nl_info info = {	.nl_net = net, };
1311 
1312 	return __ip6_ins_rt(rt, &info, NULL);
1313 }
1314 
ip6_rt_cache_alloc(const struct fib6_result * res,const struct in6_addr * daddr,const struct in6_addr * saddr)1315 static struct rt6_info *ip6_rt_cache_alloc(const struct fib6_result *res,
1316 					   const struct in6_addr *daddr,
1317 					   const struct in6_addr *saddr)
1318 {
1319 	struct fib6_info *f6i = res->f6i;
1320 	struct net_device *dev;
1321 	struct rt6_info *rt;
1322 
1323 	/*
1324 	 *	Clone the route.
1325 	 */
1326 
1327 	if (!fib6_info_hold_safe(f6i))
1328 		return NULL;
1329 
1330 	dev = ip6_rt_get_dev_rcu(res);
1331 	rt = ip6_dst_alloc(dev_net(dev), dev, 0);
1332 	if (!rt) {
1333 		fib6_info_release(f6i);
1334 		return NULL;
1335 	}
1336 
1337 	ip6_rt_copy_init(rt, res);
1338 	rt->rt6i_flags |= RTF_CACHE;
1339 	rt->rt6i_dst.addr = *daddr;
1340 	rt->rt6i_dst.plen = 128;
1341 
1342 	if (!rt6_is_gw_or_nonexthop(res)) {
1343 		if (f6i->fib6_dst.plen != 128 &&
1344 		    ipv6_addr_equal(&f6i->fib6_dst.addr, daddr))
1345 			rt->rt6i_flags |= RTF_ANYCAST;
1346 #ifdef CONFIG_IPV6_SUBTREES
1347 		if (rt->rt6i_src.plen && saddr) {
1348 			rt->rt6i_src.addr = *saddr;
1349 			rt->rt6i_src.plen = 128;
1350 		}
1351 #endif
1352 	}
1353 
1354 	return rt;
1355 }
1356 
ip6_rt_pcpu_alloc(const struct fib6_result * res)1357 static struct rt6_info *ip6_rt_pcpu_alloc(const struct fib6_result *res)
1358 {
1359 	struct fib6_info *f6i = res->f6i;
1360 	unsigned short flags = fib6_info_dst_flags(f6i);
1361 	struct net_device *dev;
1362 	struct rt6_info *pcpu_rt;
1363 
1364 	if (!fib6_info_hold_safe(f6i))
1365 		return NULL;
1366 
1367 	rcu_read_lock();
1368 	dev = ip6_rt_get_dev_rcu(res);
1369 	pcpu_rt = ip6_dst_alloc(dev_net(dev), dev, flags | DST_NOCOUNT);
1370 	rcu_read_unlock();
1371 	if (!pcpu_rt) {
1372 		fib6_info_release(f6i);
1373 		return NULL;
1374 	}
1375 	ip6_rt_copy_init(pcpu_rt, res);
1376 	pcpu_rt->rt6i_flags |= RTF_PCPU;
1377 
1378 	if (f6i->nh)
1379 		pcpu_rt->sernum = rt_genid_ipv6(dev_net(dev));
1380 
1381 	return pcpu_rt;
1382 }
1383 
rt6_is_valid(const struct rt6_info * rt6)1384 static bool rt6_is_valid(const struct rt6_info *rt6)
1385 {
1386 	return rt6->sernum == rt_genid_ipv6(dev_net(rt6->dst.dev));
1387 }
1388 
1389 /* It should be called with rcu_read_lock() acquired */
rt6_get_pcpu_route(const struct fib6_result * res)1390 static struct rt6_info *rt6_get_pcpu_route(const struct fib6_result *res)
1391 {
1392 	struct rt6_info *pcpu_rt;
1393 
1394 	pcpu_rt = this_cpu_read(*res->nh->rt6i_pcpu);
1395 
1396 	if (pcpu_rt && pcpu_rt->sernum && !rt6_is_valid(pcpu_rt)) {
1397 		struct rt6_info *prev, **p;
1398 
1399 		p = this_cpu_ptr(res->nh->rt6i_pcpu);
1400 		prev = xchg(p, NULL);
1401 		if (prev) {
1402 			dst_dev_put(&prev->dst);
1403 			dst_release(&prev->dst);
1404 		}
1405 
1406 		pcpu_rt = NULL;
1407 	}
1408 
1409 	return pcpu_rt;
1410 }
1411 
rt6_make_pcpu_route(struct net * net,const struct fib6_result * res)1412 static struct rt6_info *rt6_make_pcpu_route(struct net *net,
1413 					    const struct fib6_result *res)
1414 {
1415 	struct rt6_info *pcpu_rt, *prev, **p;
1416 
1417 	pcpu_rt = ip6_rt_pcpu_alloc(res);
1418 	if (!pcpu_rt)
1419 		return NULL;
1420 
1421 	p = this_cpu_ptr(res->nh->rt6i_pcpu);
1422 	prev = cmpxchg(p, NULL, pcpu_rt);
1423 	BUG_ON(prev);
1424 
1425 	if (res->f6i->fib6_destroying) {
1426 		struct fib6_info *from;
1427 
1428 		from = xchg((__force struct fib6_info **)&pcpu_rt->from, NULL);
1429 		fib6_info_release(from);
1430 	}
1431 
1432 	return pcpu_rt;
1433 }
1434 
1435 /* exception hash table implementation
1436  */
1437 static DEFINE_SPINLOCK(rt6_exception_lock);
1438 
1439 /* Remove rt6_ex from hash table and free the memory
1440  * Caller must hold rt6_exception_lock
1441  */
rt6_remove_exception(struct rt6_exception_bucket * bucket,struct rt6_exception * rt6_ex)1442 static void rt6_remove_exception(struct rt6_exception_bucket *bucket,
1443 				 struct rt6_exception *rt6_ex)
1444 {
1445 	struct fib6_info *from;
1446 	struct net *net;
1447 
1448 	if (!bucket || !rt6_ex)
1449 		return;
1450 
1451 	net = dev_net(rt6_ex->rt6i->dst.dev);
1452 	net->ipv6.rt6_stats->fib_rt_cache--;
1453 
1454 	/* purge completely the exception to allow releasing the held resources:
1455 	 * some [sk] cache may keep the dst around for unlimited time
1456 	 */
1457 	from = xchg((__force struct fib6_info **)&rt6_ex->rt6i->from, NULL);
1458 	fib6_info_release(from);
1459 	dst_dev_put(&rt6_ex->rt6i->dst);
1460 
1461 	hlist_del_rcu(&rt6_ex->hlist);
1462 	dst_release(&rt6_ex->rt6i->dst);
1463 	kfree_rcu(rt6_ex, rcu);
1464 	WARN_ON_ONCE(!bucket->depth);
1465 	bucket->depth--;
1466 }
1467 
1468 /* Remove oldest rt6_ex in bucket and free the memory
1469  * Caller must hold rt6_exception_lock
1470  */
rt6_exception_remove_oldest(struct rt6_exception_bucket * bucket)1471 static void rt6_exception_remove_oldest(struct rt6_exception_bucket *bucket)
1472 {
1473 	struct rt6_exception *rt6_ex, *oldest = NULL;
1474 
1475 	if (!bucket)
1476 		return;
1477 
1478 	hlist_for_each_entry(rt6_ex, &bucket->chain, hlist) {
1479 		if (!oldest || time_before(rt6_ex->stamp, oldest->stamp))
1480 			oldest = rt6_ex;
1481 	}
1482 	rt6_remove_exception(bucket, oldest);
1483 }
1484 
rt6_exception_hash(const struct in6_addr * dst,const struct in6_addr * src)1485 static u32 rt6_exception_hash(const struct in6_addr *dst,
1486 			      const struct in6_addr *src)
1487 {
1488 	static siphash_aligned_key_t rt6_exception_key;
1489 	struct {
1490 		struct in6_addr dst;
1491 		struct in6_addr src;
1492 	} __aligned(SIPHASH_ALIGNMENT) combined = {
1493 		.dst = *dst,
1494 	};
1495 	u64 val;
1496 
1497 	net_get_random_once(&rt6_exception_key, sizeof(rt6_exception_key));
1498 
1499 #ifdef CONFIG_IPV6_SUBTREES
1500 	if (src)
1501 		combined.src = *src;
1502 #endif
1503 	val = siphash(&combined, sizeof(combined), &rt6_exception_key);
1504 
1505 	return hash_64(val, FIB6_EXCEPTION_BUCKET_SIZE_SHIFT);
1506 }
1507 
1508 /* Helper function to find the cached rt in the hash table
1509  * and update bucket pointer to point to the bucket for this
1510  * (daddr, saddr) pair
1511  * Caller must hold rt6_exception_lock
1512  */
1513 static struct rt6_exception *
__rt6_find_exception_spinlock(struct rt6_exception_bucket ** bucket,const struct in6_addr * daddr,const struct in6_addr * saddr)1514 __rt6_find_exception_spinlock(struct rt6_exception_bucket **bucket,
1515 			      const struct in6_addr *daddr,
1516 			      const struct in6_addr *saddr)
1517 {
1518 	struct rt6_exception *rt6_ex;
1519 	u32 hval;
1520 
1521 	if (!(*bucket) || !daddr)
1522 		return NULL;
1523 
1524 	hval = rt6_exception_hash(daddr, saddr);
1525 	*bucket += hval;
1526 
1527 	hlist_for_each_entry(rt6_ex, &(*bucket)->chain, hlist) {
1528 		struct rt6_info *rt6 = rt6_ex->rt6i;
1529 		bool matched = ipv6_addr_equal(daddr, &rt6->rt6i_dst.addr);
1530 
1531 #ifdef CONFIG_IPV6_SUBTREES
1532 		if (matched && saddr)
1533 			matched = ipv6_addr_equal(saddr, &rt6->rt6i_src.addr);
1534 #endif
1535 		if (matched)
1536 			return rt6_ex;
1537 	}
1538 	return NULL;
1539 }
1540 
1541 /* Helper function to find the cached rt in the hash table
1542  * and update bucket pointer to point to the bucket for this
1543  * (daddr, saddr) pair
1544  * Caller must hold rcu_read_lock()
1545  */
1546 static struct rt6_exception *
__rt6_find_exception_rcu(struct rt6_exception_bucket ** bucket,const struct in6_addr * daddr,const struct in6_addr * saddr)1547 __rt6_find_exception_rcu(struct rt6_exception_bucket **bucket,
1548 			 const struct in6_addr *daddr,
1549 			 const struct in6_addr *saddr)
1550 {
1551 	struct rt6_exception *rt6_ex;
1552 	u32 hval;
1553 
1554 	WARN_ON_ONCE(!rcu_read_lock_held());
1555 
1556 	if (!(*bucket) || !daddr)
1557 		return NULL;
1558 
1559 	hval = rt6_exception_hash(daddr, saddr);
1560 	*bucket += hval;
1561 
1562 	hlist_for_each_entry_rcu(rt6_ex, &(*bucket)->chain, hlist) {
1563 		struct rt6_info *rt6 = rt6_ex->rt6i;
1564 		bool matched = ipv6_addr_equal(daddr, &rt6->rt6i_dst.addr);
1565 
1566 #ifdef CONFIG_IPV6_SUBTREES
1567 		if (matched && saddr)
1568 			matched = ipv6_addr_equal(saddr, &rt6->rt6i_src.addr);
1569 #endif
1570 		if (matched)
1571 			return rt6_ex;
1572 	}
1573 	return NULL;
1574 }
1575 
fib6_mtu(const struct fib6_result * res)1576 static unsigned int fib6_mtu(const struct fib6_result *res)
1577 {
1578 	const struct fib6_nh *nh = res->nh;
1579 	unsigned int mtu;
1580 
1581 	if (res->f6i->fib6_pmtu) {
1582 		mtu = res->f6i->fib6_pmtu;
1583 	} else {
1584 		struct net_device *dev = nh->fib_nh_dev;
1585 		struct inet6_dev *idev;
1586 
1587 		rcu_read_lock();
1588 		idev = __in6_dev_get(dev);
1589 		mtu = idev->cnf.mtu6;
1590 		rcu_read_unlock();
1591 	}
1592 
1593 	mtu = min_t(unsigned int, mtu, IP6_MAX_MTU);
1594 
1595 	return mtu - lwtunnel_headroom(nh->fib_nh_lws, mtu);
1596 }
1597 
1598 #define FIB6_EXCEPTION_BUCKET_FLUSHED  0x1UL
1599 
1600 /* used when the flushed bit is not relevant, only access to the bucket
1601  * (ie., all bucket users except rt6_insert_exception);
1602  *
1603  * called under rcu lock; sometimes called with rt6_exception_lock held
1604  */
1605 static
fib6_nh_get_excptn_bucket(const struct fib6_nh * nh,spinlock_t * lock)1606 struct rt6_exception_bucket *fib6_nh_get_excptn_bucket(const struct fib6_nh *nh,
1607 						       spinlock_t *lock)
1608 {
1609 	struct rt6_exception_bucket *bucket;
1610 
1611 	if (lock)
1612 		bucket = rcu_dereference_protected(nh->rt6i_exception_bucket,
1613 						   lockdep_is_held(lock));
1614 	else
1615 		bucket = rcu_dereference(nh->rt6i_exception_bucket);
1616 
1617 	/* remove bucket flushed bit if set */
1618 	if (bucket) {
1619 		unsigned long p = (unsigned long)bucket;
1620 
1621 		p &= ~FIB6_EXCEPTION_BUCKET_FLUSHED;
1622 		bucket = (struct rt6_exception_bucket *)p;
1623 	}
1624 
1625 	return bucket;
1626 }
1627 
fib6_nh_excptn_bucket_flushed(struct rt6_exception_bucket * bucket)1628 static bool fib6_nh_excptn_bucket_flushed(struct rt6_exception_bucket *bucket)
1629 {
1630 	unsigned long p = (unsigned long)bucket;
1631 
1632 	return !!(p & FIB6_EXCEPTION_BUCKET_FLUSHED);
1633 }
1634 
1635 /* called with rt6_exception_lock held */
fib6_nh_excptn_bucket_set_flushed(struct fib6_nh * nh,spinlock_t * lock)1636 static void fib6_nh_excptn_bucket_set_flushed(struct fib6_nh *nh,
1637 					      spinlock_t *lock)
1638 {
1639 	struct rt6_exception_bucket *bucket;
1640 	unsigned long p;
1641 
1642 	bucket = rcu_dereference_protected(nh->rt6i_exception_bucket,
1643 					   lockdep_is_held(lock));
1644 
1645 	p = (unsigned long)bucket;
1646 	p |= FIB6_EXCEPTION_BUCKET_FLUSHED;
1647 	bucket = (struct rt6_exception_bucket *)p;
1648 	rcu_assign_pointer(nh->rt6i_exception_bucket, bucket);
1649 }
1650 
rt6_insert_exception(struct rt6_info * nrt,const struct fib6_result * res)1651 static int rt6_insert_exception(struct rt6_info *nrt,
1652 				const struct fib6_result *res)
1653 {
1654 	struct net *net = dev_net(nrt->dst.dev);
1655 	struct rt6_exception_bucket *bucket;
1656 	struct fib6_info *f6i = res->f6i;
1657 	struct in6_addr *src_key = NULL;
1658 	struct rt6_exception *rt6_ex;
1659 	struct fib6_nh *nh = res->nh;
1660 	int max_depth;
1661 	int err = 0;
1662 
1663 	spin_lock_bh(&rt6_exception_lock);
1664 
1665 	bucket = rcu_dereference_protected(nh->rt6i_exception_bucket,
1666 					  lockdep_is_held(&rt6_exception_lock));
1667 	if (!bucket) {
1668 		bucket = kcalloc(FIB6_EXCEPTION_BUCKET_SIZE, sizeof(*bucket),
1669 				 GFP_ATOMIC);
1670 		if (!bucket) {
1671 			err = -ENOMEM;
1672 			goto out;
1673 		}
1674 		rcu_assign_pointer(nh->rt6i_exception_bucket, bucket);
1675 	} else if (fib6_nh_excptn_bucket_flushed(bucket)) {
1676 		err = -EINVAL;
1677 		goto out;
1678 	}
1679 
1680 #ifdef CONFIG_IPV6_SUBTREES
1681 	/* fib6_src.plen != 0 indicates f6i is in subtree
1682 	 * and exception table is indexed by a hash of
1683 	 * both fib6_dst and fib6_src.
1684 	 * Otherwise, the exception table is indexed by
1685 	 * a hash of only fib6_dst.
1686 	 */
1687 	if (f6i->fib6_src.plen)
1688 		src_key = &nrt->rt6i_src.addr;
1689 #endif
1690 	/* rt6_mtu_change() might lower mtu on f6i.
1691 	 * Only insert this exception route if its mtu
1692 	 * is less than f6i's mtu value.
1693 	 */
1694 	if (dst_metric_raw(&nrt->dst, RTAX_MTU) >= fib6_mtu(res)) {
1695 		err = -EINVAL;
1696 		goto out;
1697 	}
1698 
1699 	rt6_ex = __rt6_find_exception_spinlock(&bucket, &nrt->rt6i_dst.addr,
1700 					       src_key);
1701 	if (rt6_ex)
1702 		rt6_remove_exception(bucket, rt6_ex);
1703 
1704 	rt6_ex = kzalloc(sizeof(*rt6_ex), GFP_ATOMIC);
1705 	if (!rt6_ex) {
1706 		err = -ENOMEM;
1707 		goto out;
1708 	}
1709 	rt6_ex->rt6i = nrt;
1710 	rt6_ex->stamp = jiffies;
1711 	hlist_add_head_rcu(&rt6_ex->hlist, &bucket->chain);
1712 	bucket->depth++;
1713 	net->ipv6.rt6_stats->fib_rt_cache++;
1714 
1715 	/* Randomize max depth to avoid some side channels attacks. */
1716 	max_depth = FIB6_MAX_DEPTH + prandom_u32_max(FIB6_MAX_DEPTH);
1717 	while (bucket->depth > max_depth)
1718 		rt6_exception_remove_oldest(bucket);
1719 
1720 out:
1721 	spin_unlock_bh(&rt6_exception_lock);
1722 
1723 	/* Update fn->fn_sernum to invalidate all cached dst */
1724 	if (!err) {
1725 		spin_lock_bh(&f6i->fib6_table->tb6_lock);
1726 		fib6_update_sernum(net, f6i);
1727 		spin_unlock_bh(&f6i->fib6_table->tb6_lock);
1728 		fib6_force_start_gc(net);
1729 	}
1730 
1731 	return err;
1732 }
1733 
fib6_nh_flush_exceptions(struct fib6_nh * nh,struct fib6_info * from)1734 static void fib6_nh_flush_exceptions(struct fib6_nh *nh, struct fib6_info *from)
1735 {
1736 	struct rt6_exception_bucket *bucket;
1737 	struct rt6_exception *rt6_ex;
1738 	struct hlist_node *tmp;
1739 	int i;
1740 
1741 	spin_lock_bh(&rt6_exception_lock);
1742 
1743 	bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock);
1744 	if (!bucket)
1745 		goto out;
1746 
1747 	/* Prevent rt6_insert_exception() to recreate the bucket list */
1748 	if (!from)
1749 		fib6_nh_excptn_bucket_set_flushed(nh, &rt6_exception_lock);
1750 
1751 	for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
1752 		hlist_for_each_entry_safe(rt6_ex, tmp, &bucket->chain, hlist) {
1753 			if (!from ||
1754 			    rcu_access_pointer(rt6_ex->rt6i->from) == from)
1755 				rt6_remove_exception(bucket, rt6_ex);
1756 		}
1757 		WARN_ON_ONCE(!from && bucket->depth);
1758 		bucket++;
1759 	}
1760 out:
1761 	spin_unlock_bh(&rt6_exception_lock);
1762 }
1763 
rt6_nh_flush_exceptions(struct fib6_nh * nh,void * arg)1764 static int rt6_nh_flush_exceptions(struct fib6_nh *nh, void *arg)
1765 {
1766 	struct fib6_info *f6i = arg;
1767 
1768 	fib6_nh_flush_exceptions(nh, f6i);
1769 
1770 	return 0;
1771 }
1772 
rt6_flush_exceptions(struct fib6_info * f6i)1773 void rt6_flush_exceptions(struct fib6_info *f6i)
1774 {
1775 	if (f6i->nh)
1776 		nexthop_for_each_fib6_nh(f6i->nh, rt6_nh_flush_exceptions,
1777 					 f6i);
1778 	else
1779 		fib6_nh_flush_exceptions(f6i->fib6_nh, f6i);
1780 }
1781 
1782 /* Find cached rt in the hash table inside passed in rt
1783  * Caller has to hold rcu_read_lock()
1784  */
rt6_find_cached_rt(const struct fib6_result * res,const struct in6_addr * daddr,const struct in6_addr * saddr)1785 static struct rt6_info *rt6_find_cached_rt(const struct fib6_result *res,
1786 					   const struct in6_addr *daddr,
1787 					   const struct in6_addr *saddr)
1788 {
1789 	const struct in6_addr *src_key = NULL;
1790 	struct rt6_exception_bucket *bucket;
1791 	struct rt6_exception *rt6_ex;
1792 	struct rt6_info *ret = NULL;
1793 
1794 #ifdef CONFIG_IPV6_SUBTREES
1795 	/* fib6i_src.plen != 0 indicates f6i is in subtree
1796 	 * and exception table is indexed by a hash of
1797 	 * both fib6_dst and fib6_src.
1798 	 * However, the src addr used to create the hash
1799 	 * might not be exactly the passed in saddr which
1800 	 * is a /128 addr from the flow.
1801 	 * So we need to use f6i->fib6_src to redo lookup
1802 	 * if the passed in saddr does not find anything.
1803 	 * (See the logic in ip6_rt_cache_alloc() on how
1804 	 * rt->rt6i_src is updated.)
1805 	 */
1806 	if (res->f6i->fib6_src.plen)
1807 		src_key = saddr;
1808 find_ex:
1809 #endif
1810 	bucket = fib6_nh_get_excptn_bucket(res->nh, NULL);
1811 	rt6_ex = __rt6_find_exception_rcu(&bucket, daddr, src_key);
1812 
1813 	if (rt6_ex && !rt6_check_expired(rt6_ex->rt6i))
1814 		ret = rt6_ex->rt6i;
1815 
1816 #ifdef CONFIG_IPV6_SUBTREES
1817 	/* Use fib6_src as src_key and redo lookup */
1818 	if (!ret && src_key && src_key != &res->f6i->fib6_src.addr) {
1819 		src_key = &res->f6i->fib6_src.addr;
1820 		goto find_ex;
1821 	}
1822 #endif
1823 
1824 	return ret;
1825 }
1826 
1827 /* 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)1828 static int fib6_nh_remove_exception(const struct fib6_nh *nh, int plen,
1829 				    const struct rt6_info *rt)
1830 {
1831 	const struct in6_addr *src_key = NULL;
1832 	struct rt6_exception_bucket *bucket;
1833 	struct rt6_exception *rt6_ex;
1834 	int err;
1835 
1836 	if (!rcu_access_pointer(nh->rt6i_exception_bucket))
1837 		return -ENOENT;
1838 
1839 	spin_lock_bh(&rt6_exception_lock);
1840 	bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock);
1841 
1842 #ifdef CONFIG_IPV6_SUBTREES
1843 	/* rt6i_src.plen != 0 indicates 'from' is in subtree
1844 	 * and exception table is indexed by a hash of
1845 	 * both rt6i_dst and rt6i_src.
1846 	 * Otherwise, the exception table is indexed by
1847 	 * a hash of only rt6i_dst.
1848 	 */
1849 	if (plen)
1850 		src_key = &rt->rt6i_src.addr;
1851 #endif
1852 	rt6_ex = __rt6_find_exception_spinlock(&bucket,
1853 					       &rt->rt6i_dst.addr,
1854 					       src_key);
1855 	if (rt6_ex) {
1856 		rt6_remove_exception(bucket, rt6_ex);
1857 		err = 0;
1858 	} else {
1859 		err = -ENOENT;
1860 	}
1861 
1862 	spin_unlock_bh(&rt6_exception_lock);
1863 	return err;
1864 }
1865 
1866 struct fib6_nh_excptn_arg {
1867 	struct rt6_info	*rt;
1868 	int		plen;
1869 };
1870 
rt6_nh_remove_exception_rt(struct fib6_nh * nh,void * _arg)1871 static int rt6_nh_remove_exception_rt(struct fib6_nh *nh, void *_arg)
1872 {
1873 	struct fib6_nh_excptn_arg *arg = _arg;
1874 	int err;
1875 
1876 	err = fib6_nh_remove_exception(nh, arg->plen, arg->rt);
1877 	if (err == 0)
1878 		return 1;
1879 
1880 	return 0;
1881 }
1882 
rt6_remove_exception_rt(struct rt6_info * rt)1883 static int rt6_remove_exception_rt(struct rt6_info *rt)
1884 {
1885 	struct fib6_info *from;
1886 
1887 	from = rcu_dereference(rt->from);
1888 	if (!from || !(rt->rt6i_flags & RTF_CACHE))
1889 		return -EINVAL;
1890 
1891 	if (from->nh) {
1892 		struct fib6_nh_excptn_arg arg = {
1893 			.rt = rt,
1894 			.plen = from->fib6_src.plen
1895 		};
1896 		int rc;
1897 
1898 		/* rc = 1 means an entry was found */
1899 		rc = nexthop_for_each_fib6_nh(from->nh,
1900 					      rt6_nh_remove_exception_rt,
1901 					      &arg);
1902 		return rc ? 0 : -ENOENT;
1903 	}
1904 
1905 	return fib6_nh_remove_exception(from->fib6_nh,
1906 					from->fib6_src.plen, rt);
1907 }
1908 
1909 /* Find rt6_ex which contains the passed in rt cache and
1910  * refresh its stamp
1911  */
fib6_nh_update_exception(const struct fib6_nh * nh,int plen,const struct rt6_info * rt)1912 static void fib6_nh_update_exception(const struct fib6_nh *nh, int plen,
1913 				     const struct rt6_info *rt)
1914 {
1915 	const struct in6_addr *src_key = NULL;
1916 	struct rt6_exception_bucket *bucket;
1917 	struct rt6_exception *rt6_ex;
1918 
1919 	bucket = fib6_nh_get_excptn_bucket(nh, NULL);
1920 #ifdef CONFIG_IPV6_SUBTREES
1921 	/* rt6i_src.plen != 0 indicates 'from' is in subtree
1922 	 * and exception table is indexed by a hash of
1923 	 * both rt6i_dst and rt6i_src.
1924 	 * Otherwise, the exception table is indexed by
1925 	 * a hash of only rt6i_dst.
1926 	 */
1927 	if (plen)
1928 		src_key = &rt->rt6i_src.addr;
1929 #endif
1930 	rt6_ex = __rt6_find_exception_rcu(&bucket, &rt->rt6i_dst.addr, src_key);
1931 	if (rt6_ex)
1932 		rt6_ex->stamp = jiffies;
1933 }
1934 
1935 struct fib6_nh_match_arg {
1936 	const struct net_device *dev;
1937 	const struct in6_addr	*gw;
1938 	struct fib6_nh		*match;
1939 };
1940 
1941 /* determine if fib6_nh has given device and gateway */
fib6_nh_find_match(struct fib6_nh * nh,void * _arg)1942 static int fib6_nh_find_match(struct fib6_nh *nh, void *_arg)
1943 {
1944 	struct fib6_nh_match_arg *arg = _arg;
1945 
1946 	if (arg->dev != nh->fib_nh_dev ||
1947 	    (arg->gw && !nh->fib_nh_gw_family) ||
1948 	    (!arg->gw && nh->fib_nh_gw_family) ||
1949 	    (arg->gw && !ipv6_addr_equal(arg->gw, &nh->fib_nh_gw6)))
1950 		return 0;
1951 
1952 	arg->match = nh;
1953 
1954 	/* found a match, break the loop */
1955 	return 1;
1956 }
1957 
rt6_update_exception_stamp_rt(struct rt6_info * rt)1958 static void rt6_update_exception_stamp_rt(struct rt6_info *rt)
1959 {
1960 	struct fib6_info *from;
1961 	struct fib6_nh *fib6_nh;
1962 
1963 	rcu_read_lock();
1964 
1965 	from = rcu_dereference(rt->from);
1966 	if (!from || !(rt->rt6i_flags & RTF_CACHE))
1967 		goto unlock;
1968 
1969 	if (from->nh) {
1970 		struct fib6_nh_match_arg arg = {
1971 			.dev = rt->dst.dev,
1972 			.gw = &rt->rt6i_gateway,
1973 		};
1974 
1975 		nexthop_for_each_fib6_nh(from->nh, fib6_nh_find_match, &arg);
1976 
1977 		if (!arg.match)
1978 			goto unlock;
1979 		fib6_nh = arg.match;
1980 	} else {
1981 		fib6_nh = from->fib6_nh;
1982 	}
1983 	fib6_nh_update_exception(fib6_nh, from->fib6_src.plen, rt);
1984 unlock:
1985 	rcu_read_unlock();
1986 }
1987 
rt6_mtu_change_route_allowed(struct inet6_dev * idev,struct rt6_info * rt,int mtu)1988 static bool rt6_mtu_change_route_allowed(struct inet6_dev *idev,
1989 					 struct rt6_info *rt, int mtu)
1990 {
1991 	/* If the new MTU is lower than the route PMTU, this new MTU will be the
1992 	 * lowest MTU in the path: always allow updating the route PMTU to
1993 	 * reflect PMTU decreases.
1994 	 *
1995 	 * If the new MTU is higher, and the route PMTU is equal to the local
1996 	 * MTU, this means the old MTU is the lowest in the path, so allow
1997 	 * updating it: if other nodes now have lower MTUs, PMTU discovery will
1998 	 * handle this.
1999 	 */
2000 
2001 	if (dst_mtu(&rt->dst) >= mtu)
2002 		return true;
2003 
2004 	if (dst_mtu(&rt->dst) == idev->cnf.mtu6)
2005 		return true;
2006 
2007 	return false;
2008 }
2009 
rt6_exceptions_update_pmtu(struct inet6_dev * idev,const struct fib6_nh * nh,int mtu)2010 static void rt6_exceptions_update_pmtu(struct inet6_dev *idev,
2011 				       const struct fib6_nh *nh, int mtu)
2012 {
2013 	struct rt6_exception_bucket *bucket;
2014 	struct rt6_exception *rt6_ex;
2015 	int i;
2016 
2017 	bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock);
2018 	if (!bucket)
2019 		return;
2020 
2021 	for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
2022 		hlist_for_each_entry(rt6_ex, &bucket->chain, hlist) {
2023 			struct rt6_info *entry = rt6_ex->rt6i;
2024 
2025 			/* For RTF_CACHE with rt6i_pmtu == 0 (i.e. a redirected
2026 			 * route), the metrics of its rt->from have already
2027 			 * been updated.
2028 			 */
2029 			if (dst_metric_raw(&entry->dst, RTAX_MTU) &&
2030 			    rt6_mtu_change_route_allowed(idev, entry, mtu))
2031 				dst_metric_set(&entry->dst, RTAX_MTU, mtu);
2032 		}
2033 		bucket++;
2034 	}
2035 }
2036 
2037 #define RTF_CACHE_GATEWAY	(RTF_GATEWAY | RTF_CACHE)
2038 
fib6_nh_exceptions_clean_tohost(const struct fib6_nh * nh,const struct in6_addr * gateway)2039 static void fib6_nh_exceptions_clean_tohost(const struct fib6_nh *nh,
2040 					    const struct in6_addr *gateway)
2041 {
2042 	struct rt6_exception_bucket *bucket;
2043 	struct rt6_exception *rt6_ex;
2044 	struct hlist_node *tmp;
2045 	int i;
2046 
2047 	if (!rcu_access_pointer(nh->rt6i_exception_bucket))
2048 		return;
2049 
2050 	spin_lock_bh(&rt6_exception_lock);
2051 	bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock);
2052 	if (bucket) {
2053 		for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
2054 			hlist_for_each_entry_safe(rt6_ex, tmp,
2055 						  &bucket->chain, hlist) {
2056 				struct rt6_info *entry = rt6_ex->rt6i;
2057 
2058 				if ((entry->rt6i_flags & RTF_CACHE_GATEWAY) ==
2059 				    RTF_CACHE_GATEWAY &&
2060 				    ipv6_addr_equal(gateway,
2061 						    &entry->rt6i_gateway)) {
2062 					rt6_remove_exception(bucket, rt6_ex);
2063 				}
2064 			}
2065 			bucket++;
2066 		}
2067 	}
2068 
2069 	spin_unlock_bh(&rt6_exception_lock);
2070 }
2071 
rt6_age_examine_exception(struct rt6_exception_bucket * bucket,struct rt6_exception * rt6_ex,struct fib6_gc_args * gc_args,unsigned long now)2072 static void rt6_age_examine_exception(struct rt6_exception_bucket *bucket,
2073 				      struct rt6_exception *rt6_ex,
2074 				      struct fib6_gc_args *gc_args,
2075 				      unsigned long now)
2076 {
2077 	struct rt6_info *rt = rt6_ex->rt6i;
2078 
2079 	/* we are pruning and obsoleting aged-out and non gateway exceptions
2080 	 * even if others have still references to them, so that on next
2081 	 * dst_check() such references can be dropped.
2082 	 * EXPIRES exceptions - e.g. pmtu-generated ones are pruned when
2083 	 * expired, independently from their aging, as per RFC 8201 section 4
2084 	 */
2085 	if (!(rt->rt6i_flags & RTF_EXPIRES)) {
2086 		if (time_after_eq(now, rt->dst.lastuse + gc_args->timeout)) {
2087 			RT6_TRACE("aging clone %p\n", rt);
2088 			rt6_remove_exception(bucket, rt6_ex);
2089 			return;
2090 		}
2091 	} else if (time_after(jiffies, rt->dst.expires)) {
2092 		RT6_TRACE("purging expired route %p\n", rt);
2093 		rt6_remove_exception(bucket, rt6_ex);
2094 		return;
2095 	}
2096 
2097 	if (rt->rt6i_flags & RTF_GATEWAY) {
2098 		struct neighbour *neigh;
2099 
2100 		neigh = __ipv6_neigh_lookup_noref(rt->dst.dev, &rt->rt6i_gateway);
2101 
2102 		if (!(neigh && (neigh->flags & NTF_ROUTER))) {
2103 			RT6_TRACE("purging route %p via non-router but gateway\n",
2104 				  rt);
2105 			rt6_remove_exception(bucket, rt6_ex);
2106 			return;
2107 		}
2108 	}
2109 
2110 	gc_args->more++;
2111 }
2112 
fib6_nh_age_exceptions(const struct fib6_nh * nh,struct fib6_gc_args * gc_args,unsigned long now)2113 static void fib6_nh_age_exceptions(const struct fib6_nh *nh,
2114 				   struct fib6_gc_args *gc_args,
2115 				   unsigned long now)
2116 {
2117 	struct rt6_exception_bucket *bucket;
2118 	struct rt6_exception *rt6_ex;
2119 	struct hlist_node *tmp;
2120 	int i;
2121 
2122 	if (!rcu_access_pointer(nh->rt6i_exception_bucket))
2123 		return;
2124 
2125 	rcu_read_lock_bh();
2126 	spin_lock(&rt6_exception_lock);
2127 	bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock);
2128 	if (bucket) {
2129 		for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
2130 			hlist_for_each_entry_safe(rt6_ex, tmp,
2131 						  &bucket->chain, hlist) {
2132 				rt6_age_examine_exception(bucket, rt6_ex,
2133 							  gc_args, now);
2134 			}
2135 			bucket++;
2136 		}
2137 	}
2138 	spin_unlock(&rt6_exception_lock);
2139 	rcu_read_unlock_bh();
2140 }
2141 
2142 struct fib6_nh_age_excptn_arg {
2143 	struct fib6_gc_args	*gc_args;
2144 	unsigned long		now;
2145 };
2146 
rt6_nh_age_exceptions(struct fib6_nh * nh,void * _arg)2147 static int rt6_nh_age_exceptions(struct fib6_nh *nh, void *_arg)
2148 {
2149 	struct fib6_nh_age_excptn_arg *arg = _arg;
2150 
2151 	fib6_nh_age_exceptions(nh, arg->gc_args, arg->now);
2152 	return 0;
2153 }
2154 
rt6_age_exceptions(struct fib6_info * f6i,struct fib6_gc_args * gc_args,unsigned long now)2155 void rt6_age_exceptions(struct fib6_info *f6i,
2156 			struct fib6_gc_args *gc_args,
2157 			unsigned long now)
2158 {
2159 	if (f6i->nh) {
2160 		struct fib6_nh_age_excptn_arg arg = {
2161 			.gc_args = gc_args,
2162 			.now = now
2163 		};
2164 
2165 		nexthop_for_each_fib6_nh(f6i->nh, rt6_nh_age_exceptions,
2166 					 &arg);
2167 	} else {
2168 		fib6_nh_age_exceptions(f6i->fib6_nh, gc_args, now);
2169 	}
2170 }
2171 
2172 /* 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)2173 int fib6_table_lookup(struct net *net, struct fib6_table *table, int oif,
2174 		      struct flowi6 *fl6, struct fib6_result *res, int strict)
2175 {
2176 	struct fib6_node *fn, *saved_fn;
2177 
2178 	fn = fib6_node_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr);
2179 	saved_fn = fn;
2180 
2181 redo_rt6_select:
2182 	rt6_select(net, fn, oif, res, strict);
2183 	if (res->f6i == net->ipv6.fib6_null_entry) {
2184 		fn = fib6_backtrack(fn, &fl6->saddr);
2185 		if (fn)
2186 			goto redo_rt6_select;
2187 		else if (strict & RT6_LOOKUP_F_REACHABLE) {
2188 			/* also consider unreachable route */
2189 			strict &= ~RT6_LOOKUP_F_REACHABLE;
2190 			fn = saved_fn;
2191 			goto redo_rt6_select;
2192 		}
2193 	}
2194 
2195 	trace_fib6_table_lookup(net, res, table, fl6);
2196 
2197 	return 0;
2198 }
2199 
ip6_pol_route(struct net * net,struct fib6_table * table,int oif,struct flowi6 * fl6,const struct sk_buff * skb,int flags)2200 struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table,
2201 			       int oif, struct flowi6 *fl6,
2202 			       const struct sk_buff *skb, int flags)
2203 {
2204 	struct fib6_result res = {};
2205 	struct rt6_info *rt = NULL;
2206 	int strict = 0;
2207 
2208 	WARN_ON_ONCE((flags & RT6_LOOKUP_F_DST_NOREF) &&
2209 		     !rcu_read_lock_held());
2210 
2211 	strict |= flags & RT6_LOOKUP_F_IFACE;
2212 	strict |= flags & RT6_LOOKUP_F_IGNORE_LINKSTATE;
2213 	if (net->ipv6.devconf_all->forwarding == 0)
2214 		strict |= RT6_LOOKUP_F_REACHABLE;
2215 
2216 	rcu_read_lock();
2217 
2218 	fib6_table_lookup(net, table, oif, fl6, &res, strict);
2219 	if (res.f6i == net->ipv6.fib6_null_entry)
2220 		goto out;
2221 
2222 	fib6_select_path(net, &res, fl6, oif, false, skb, strict);
2223 
2224 	/*Search through exception table */
2225 	rt = rt6_find_cached_rt(&res, &fl6->daddr, &fl6->saddr);
2226 	if (rt) {
2227 		goto out;
2228 	} else if (unlikely((fl6->flowi6_flags & FLOWI_FLAG_KNOWN_NH) &&
2229 			    !res.nh->fib_nh_gw_family)) {
2230 		/* Create a RTF_CACHE clone which will not be
2231 		 * owned by the fib6 tree.  It is for the special case where
2232 		 * the daddr in the skb during the neighbor look-up is different
2233 		 * from the fl6->daddr used to look-up route here.
2234 		 */
2235 		rt = ip6_rt_cache_alloc(&res, &fl6->daddr, NULL);
2236 
2237 		if (rt) {
2238 			/* 1 refcnt is taken during ip6_rt_cache_alloc().
2239 			 * As rt6_uncached_list_add() does not consume refcnt,
2240 			 * this refcnt is always returned to the caller even
2241 			 * if caller sets RT6_LOOKUP_F_DST_NOREF flag.
2242 			 */
2243 			rt6_uncached_list_add(rt);
2244 			rcu_read_unlock();
2245 
2246 			return rt;
2247 		}
2248 	} else {
2249 		/* Get a percpu copy */
2250 		local_bh_disable();
2251 		rt = rt6_get_pcpu_route(&res);
2252 
2253 		if (!rt)
2254 			rt = rt6_make_pcpu_route(net, &res);
2255 
2256 		local_bh_enable();
2257 	}
2258 out:
2259 	if (!rt)
2260 		rt = net->ipv6.ip6_null_entry;
2261 	if (!(flags & RT6_LOOKUP_F_DST_NOREF))
2262 		ip6_hold_safe(net, &rt);
2263 	rcu_read_unlock();
2264 
2265 	return rt;
2266 }
2267 EXPORT_SYMBOL_GPL(ip6_pol_route);
2268 
ip6_pol_route_input(struct net * net,struct fib6_table * table,struct flowi6 * fl6,const struct sk_buff * skb,int flags)2269 INDIRECT_CALLABLE_SCOPE struct rt6_info *ip6_pol_route_input(struct net *net,
2270 					    struct fib6_table *table,
2271 					    struct flowi6 *fl6,
2272 					    const struct sk_buff *skb,
2273 					    int flags)
2274 {
2275 	return ip6_pol_route(net, table, fl6->flowi6_iif, fl6, skb, flags);
2276 }
2277 
ip6_route_input_lookup(struct net * net,struct net_device * dev,struct flowi6 * fl6,const struct sk_buff * skb,int flags)2278 struct dst_entry *ip6_route_input_lookup(struct net *net,
2279 					 struct net_device *dev,
2280 					 struct flowi6 *fl6,
2281 					 const struct sk_buff *skb,
2282 					 int flags)
2283 {
2284 	if (rt6_need_strict(&fl6->daddr) && dev->type != ARPHRD_PIMREG)
2285 		flags |= RT6_LOOKUP_F_IFACE;
2286 
2287 	return fib6_rule_lookup(net, fl6, skb, flags, ip6_pol_route_input);
2288 }
2289 EXPORT_SYMBOL_GPL(ip6_route_input_lookup);
2290 
ip6_multipath_l3_keys(const struct sk_buff * skb,struct flow_keys * keys,struct flow_keys * flkeys)2291 static void ip6_multipath_l3_keys(const struct sk_buff *skb,
2292 				  struct flow_keys *keys,
2293 				  struct flow_keys *flkeys)
2294 {
2295 	const struct ipv6hdr *outer_iph = ipv6_hdr(skb);
2296 	const struct ipv6hdr *key_iph = outer_iph;
2297 	struct flow_keys *_flkeys = flkeys;
2298 	const struct ipv6hdr *inner_iph;
2299 	const struct icmp6hdr *icmph;
2300 	struct ipv6hdr _inner_iph;
2301 	struct icmp6hdr _icmph;
2302 
2303 	if (likely(outer_iph->nexthdr != IPPROTO_ICMPV6))
2304 		goto out;
2305 
2306 	icmph = skb_header_pointer(skb, skb_transport_offset(skb),
2307 				   sizeof(_icmph), &_icmph);
2308 	if (!icmph)
2309 		goto out;
2310 
2311 	if (!icmpv6_is_err(icmph->icmp6_type))
2312 		goto out;
2313 
2314 	inner_iph = skb_header_pointer(skb,
2315 				       skb_transport_offset(skb) + sizeof(*icmph),
2316 				       sizeof(_inner_iph), &_inner_iph);
2317 	if (!inner_iph)
2318 		goto out;
2319 
2320 	key_iph = inner_iph;
2321 	_flkeys = NULL;
2322 out:
2323 	if (_flkeys) {
2324 		keys->addrs.v6addrs.src = _flkeys->addrs.v6addrs.src;
2325 		keys->addrs.v6addrs.dst = _flkeys->addrs.v6addrs.dst;
2326 		keys->tags.flow_label = _flkeys->tags.flow_label;
2327 		keys->basic.ip_proto = _flkeys->basic.ip_proto;
2328 	} else {
2329 		keys->addrs.v6addrs.src = key_iph->saddr;
2330 		keys->addrs.v6addrs.dst = key_iph->daddr;
2331 		keys->tags.flow_label = ip6_flowlabel(key_iph);
2332 		keys->basic.ip_proto = key_iph->nexthdr;
2333 	}
2334 }
2335 
rt6_multipath_custom_hash_outer(const struct net * net,const struct sk_buff * skb,bool * p_has_inner)2336 static u32 rt6_multipath_custom_hash_outer(const struct net *net,
2337 					   const struct sk_buff *skb,
2338 					   bool *p_has_inner)
2339 {
2340 	u32 hash_fields = ip6_multipath_hash_fields(net);
2341 	struct flow_keys keys, hash_keys;
2342 
2343 	if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK))
2344 		return 0;
2345 
2346 	memset(&hash_keys, 0, sizeof(hash_keys));
2347 	skb_flow_dissect_flow_keys(skb, &keys, FLOW_DISSECTOR_F_STOP_AT_ENCAP);
2348 
2349 	hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2350 	if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP)
2351 		hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src;
2352 	if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP)
2353 		hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst;
2354 	if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO)
2355 		hash_keys.basic.ip_proto = keys.basic.ip_proto;
2356 	if (hash_fields & FIB_MULTIPATH_HASH_FIELD_FLOWLABEL)
2357 		hash_keys.tags.flow_label = keys.tags.flow_label;
2358 	if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT)
2359 		hash_keys.ports.src = keys.ports.src;
2360 	if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT)
2361 		hash_keys.ports.dst = keys.ports.dst;
2362 
2363 	*p_has_inner = !!(keys.control.flags & FLOW_DIS_ENCAPSULATION);
2364 	return flow_hash_from_keys(&hash_keys);
2365 }
2366 
rt6_multipath_custom_hash_inner(const struct net * net,const struct sk_buff * skb,bool has_inner)2367 static u32 rt6_multipath_custom_hash_inner(const struct net *net,
2368 					   const struct sk_buff *skb,
2369 					   bool has_inner)
2370 {
2371 	u32 hash_fields = ip6_multipath_hash_fields(net);
2372 	struct flow_keys keys, hash_keys;
2373 
2374 	/* We assume the packet carries an encapsulation, but if none was
2375 	 * encountered during dissection of the outer flow, then there is no
2376 	 * point in calling the flow dissector again.
2377 	 */
2378 	if (!has_inner)
2379 		return 0;
2380 
2381 	if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_MASK))
2382 		return 0;
2383 
2384 	memset(&hash_keys, 0, sizeof(hash_keys));
2385 	skb_flow_dissect_flow_keys(skb, &keys, 0);
2386 
2387 	if (!(keys.control.flags & FLOW_DIS_ENCAPSULATION))
2388 		return 0;
2389 
2390 	if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) {
2391 		hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
2392 		if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP)
2393 			hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src;
2394 		if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP)
2395 			hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst;
2396 	} else if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) {
2397 		hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2398 		if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP)
2399 			hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src;
2400 		if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP)
2401 			hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst;
2402 		if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_FLOWLABEL)
2403 			hash_keys.tags.flow_label = keys.tags.flow_label;
2404 	}
2405 
2406 	if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_IP_PROTO)
2407 		hash_keys.basic.ip_proto = keys.basic.ip_proto;
2408 	if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_PORT)
2409 		hash_keys.ports.src = keys.ports.src;
2410 	if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_PORT)
2411 		hash_keys.ports.dst = keys.ports.dst;
2412 
2413 	return flow_hash_from_keys(&hash_keys);
2414 }
2415 
rt6_multipath_custom_hash_skb(const struct net * net,const struct sk_buff * skb)2416 static u32 rt6_multipath_custom_hash_skb(const struct net *net,
2417 					 const struct sk_buff *skb)
2418 {
2419 	u32 mhash, mhash_inner;
2420 	bool has_inner = true;
2421 
2422 	mhash = rt6_multipath_custom_hash_outer(net, skb, &has_inner);
2423 	mhash_inner = rt6_multipath_custom_hash_inner(net, skb, has_inner);
2424 
2425 	return jhash_2words(mhash, mhash_inner, 0);
2426 }
2427 
rt6_multipath_custom_hash_fl6(const struct net * net,const struct flowi6 * fl6)2428 static u32 rt6_multipath_custom_hash_fl6(const struct net *net,
2429 					 const struct flowi6 *fl6)
2430 {
2431 	u32 hash_fields = ip6_multipath_hash_fields(net);
2432 	struct flow_keys hash_keys;
2433 
2434 	if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK))
2435 		return 0;
2436 
2437 	memset(&hash_keys, 0, sizeof(hash_keys));
2438 	hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2439 	if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP)
2440 		hash_keys.addrs.v6addrs.src = fl6->saddr;
2441 	if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP)
2442 		hash_keys.addrs.v6addrs.dst = fl6->daddr;
2443 	if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO)
2444 		hash_keys.basic.ip_proto = fl6->flowi6_proto;
2445 	if (hash_fields & FIB_MULTIPATH_HASH_FIELD_FLOWLABEL)
2446 		hash_keys.tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6);
2447 	if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT)
2448 		hash_keys.ports.src = fl6->fl6_sport;
2449 	if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT)
2450 		hash_keys.ports.dst = fl6->fl6_dport;
2451 
2452 	return flow_hash_from_keys(&hash_keys);
2453 }
2454 
2455 /* 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)2456 u32 rt6_multipath_hash(const struct net *net, const struct flowi6 *fl6,
2457 		       const struct sk_buff *skb, struct flow_keys *flkeys)
2458 {
2459 	struct flow_keys hash_keys;
2460 	u32 mhash = 0;
2461 
2462 	switch (ip6_multipath_hash_policy(net)) {
2463 	case 0:
2464 		memset(&hash_keys, 0, sizeof(hash_keys));
2465 		hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2466 		if (skb) {
2467 			ip6_multipath_l3_keys(skb, &hash_keys, flkeys);
2468 		} else {
2469 			hash_keys.addrs.v6addrs.src = fl6->saddr;
2470 			hash_keys.addrs.v6addrs.dst = fl6->daddr;
2471 			hash_keys.tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6);
2472 			hash_keys.basic.ip_proto = fl6->flowi6_proto;
2473 		}
2474 		mhash = flow_hash_from_keys(&hash_keys);
2475 		break;
2476 	case 1:
2477 		if (skb) {
2478 			unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP;
2479 			struct flow_keys keys;
2480 
2481 			/* short-circuit if we already have L4 hash present */
2482 			if (skb->l4_hash)
2483 				return skb_get_hash_raw(skb) >> 1;
2484 
2485 			memset(&hash_keys, 0, sizeof(hash_keys));
2486 
2487 			if (!flkeys) {
2488 				skb_flow_dissect_flow_keys(skb, &keys, flag);
2489 				flkeys = &keys;
2490 			}
2491 			hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2492 			hash_keys.addrs.v6addrs.src = flkeys->addrs.v6addrs.src;
2493 			hash_keys.addrs.v6addrs.dst = flkeys->addrs.v6addrs.dst;
2494 			hash_keys.ports.src = flkeys->ports.src;
2495 			hash_keys.ports.dst = flkeys->ports.dst;
2496 			hash_keys.basic.ip_proto = flkeys->basic.ip_proto;
2497 		} else {
2498 			memset(&hash_keys, 0, sizeof(hash_keys));
2499 			hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2500 			hash_keys.addrs.v6addrs.src = fl6->saddr;
2501 			hash_keys.addrs.v6addrs.dst = fl6->daddr;
2502 			hash_keys.ports.src = fl6->fl6_sport;
2503 			hash_keys.ports.dst = fl6->fl6_dport;
2504 			hash_keys.basic.ip_proto = fl6->flowi6_proto;
2505 		}
2506 		mhash = flow_hash_from_keys(&hash_keys);
2507 		break;
2508 	case 2:
2509 		memset(&hash_keys, 0, sizeof(hash_keys));
2510 		hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2511 		if (skb) {
2512 			struct flow_keys keys;
2513 
2514 			if (!flkeys) {
2515 				skb_flow_dissect_flow_keys(skb, &keys, 0);
2516 				flkeys = &keys;
2517 			}
2518 
2519 			/* Inner can be v4 or v6 */
2520 			if (flkeys->control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) {
2521 				hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
2522 				hash_keys.addrs.v4addrs.src = flkeys->addrs.v4addrs.src;
2523 				hash_keys.addrs.v4addrs.dst = flkeys->addrs.v4addrs.dst;
2524 			} else if (flkeys->control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) {
2525 				hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2526 				hash_keys.addrs.v6addrs.src = flkeys->addrs.v6addrs.src;
2527 				hash_keys.addrs.v6addrs.dst = flkeys->addrs.v6addrs.dst;
2528 				hash_keys.tags.flow_label = flkeys->tags.flow_label;
2529 				hash_keys.basic.ip_proto = flkeys->basic.ip_proto;
2530 			} else {
2531 				/* Same as case 0 */
2532 				hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2533 				ip6_multipath_l3_keys(skb, &hash_keys, flkeys);
2534 			}
2535 		} else {
2536 			/* Same as case 0 */
2537 			hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2538 			hash_keys.addrs.v6addrs.src = fl6->saddr;
2539 			hash_keys.addrs.v6addrs.dst = fl6->daddr;
2540 			hash_keys.tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6);
2541 			hash_keys.basic.ip_proto = fl6->flowi6_proto;
2542 		}
2543 		mhash = flow_hash_from_keys(&hash_keys);
2544 		break;
2545 	case 3:
2546 		if (skb)
2547 			mhash = rt6_multipath_custom_hash_skb(net, skb);
2548 		else
2549 			mhash = rt6_multipath_custom_hash_fl6(net, fl6);
2550 		break;
2551 	}
2552 
2553 	return mhash >> 1;
2554 }
2555 
2556 /* Called with rcu held */
ip6_route_input(struct sk_buff * skb)2557 void ip6_route_input(struct sk_buff *skb)
2558 {
2559 	const struct ipv6hdr *iph = ipv6_hdr(skb);
2560 	struct net *net = dev_net(skb->dev);
2561 	int flags = RT6_LOOKUP_F_HAS_SADDR | RT6_LOOKUP_F_DST_NOREF;
2562 	struct ip_tunnel_info *tun_info;
2563 	struct flowi6 fl6 = {
2564 		.flowi6_iif = skb->dev->ifindex,
2565 		.daddr = iph->daddr,
2566 		.saddr = iph->saddr,
2567 		.flowlabel = ip6_flowinfo(iph),
2568 		.flowi6_mark = skb->mark,
2569 		.flowi6_proto = iph->nexthdr,
2570 	};
2571 	struct flow_keys *flkeys = NULL, _flkeys;
2572 
2573 	tun_info = skb_tunnel_info(skb);
2574 	if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX))
2575 		fl6.flowi6_tun_key.tun_id = tun_info->key.tun_id;
2576 
2577 	if (fib6_rules_early_flow_dissect(net, skb, &fl6, &_flkeys))
2578 		flkeys = &_flkeys;
2579 
2580 	if (unlikely(fl6.flowi6_proto == IPPROTO_ICMPV6))
2581 		fl6.mp_hash = rt6_multipath_hash(net, &fl6, skb, flkeys);
2582 	skb_dst_drop(skb);
2583 	skb_dst_set_noref(skb, ip6_route_input_lookup(net, skb->dev,
2584 						      &fl6, skb, flags));
2585 }
2586 
ip6_pol_route_output(struct net * net,struct fib6_table * table,struct flowi6 * fl6,const struct sk_buff * skb,int flags)2587 INDIRECT_CALLABLE_SCOPE struct rt6_info *ip6_pol_route_output(struct net *net,
2588 					     struct fib6_table *table,
2589 					     struct flowi6 *fl6,
2590 					     const struct sk_buff *skb,
2591 					     int flags)
2592 {
2593 	return ip6_pol_route(net, table, fl6->flowi6_oif, fl6, skb, flags);
2594 }
2595 
ip6_route_output_flags_noref(struct net * net,const struct sock * sk,struct flowi6 * fl6,int flags)2596 struct dst_entry *ip6_route_output_flags_noref(struct net *net,
2597 					       const struct sock *sk,
2598 					       struct flowi6 *fl6, int flags)
2599 {
2600 	bool any_src;
2601 
2602 	if (ipv6_addr_type(&fl6->daddr) &
2603 	    (IPV6_ADDR_MULTICAST | IPV6_ADDR_LINKLOCAL)) {
2604 		struct dst_entry *dst;
2605 
2606 		/* This function does not take refcnt on the dst */
2607 		dst = l3mdev_link_scope_lookup(net, fl6);
2608 		if (dst)
2609 			return dst;
2610 	}
2611 
2612 	fl6->flowi6_iif = LOOPBACK_IFINDEX;
2613 
2614 	flags |= RT6_LOOKUP_F_DST_NOREF;
2615 	any_src = ipv6_addr_any(&fl6->saddr);
2616 	if ((sk && sk->sk_bound_dev_if) || rt6_need_strict(&fl6->daddr) ||
2617 	    (fl6->flowi6_oif && any_src))
2618 		flags |= RT6_LOOKUP_F_IFACE;
2619 
2620 	if (!any_src)
2621 		flags |= RT6_LOOKUP_F_HAS_SADDR;
2622 	else if (sk)
2623 		flags |= rt6_srcprefs2flags(inet6_sk(sk)->srcprefs);
2624 
2625 	return fib6_rule_lookup(net, fl6, NULL, flags, ip6_pol_route_output);
2626 }
2627 EXPORT_SYMBOL_GPL(ip6_route_output_flags_noref);
2628 
ip6_route_output_flags(struct net * net,const struct sock * sk,struct flowi6 * fl6,int flags)2629 struct dst_entry *ip6_route_output_flags(struct net *net,
2630 					 const struct sock *sk,
2631 					 struct flowi6 *fl6,
2632 					 int flags)
2633 {
2634 	struct dst_entry *dst;
2635 	struct rt6_info *rt6;
2636 
2637 	rcu_read_lock();
2638 	dst = ip6_route_output_flags_noref(net, sk, fl6, flags);
2639 	rt6 = (struct rt6_info *)dst;
2640 	/* For dst cached in uncached_list, refcnt is already taken. */
2641 	if (list_empty(&rt6->rt6i_uncached) && !dst_hold_safe(dst)) {
2642 		dst = &net->ipv6.ip6_null_entry->dst;
2643 		dst_hold(dst);
2644 	}
2645 	rcu_read_unlock();
2646 
2647 	return dst;
2648 }
2649 EXPORT_SYMBOL_GPL(ip6_route_output_flags);
2650 
ip6_blackhole_route(struct net * net,struct dst_entry * dst_orig)2651 struct dst_entry *ip6_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2652 {
2653 	struct rt6_info *rt, *ort = (struct rt6_info *) dst_orig;
2654 	struct net_device *loopback_dev = net->loopback_dev;
2655 	struct dst_entry *new = NULL;
2656 
2657 	rt = dst_alloc(&ip6_dst_blackhole_ops, loopback_dev, 1,
2658 		       DST_OBSOLETE_DEAD, 0);
2659 	if (rt) {
2660 		rt6_info_init(rt);
2661 		atomic_inc(&net->ipv6.rt6_stats->fib_rt_alloc);
2662 
2663 		new = &rt->dst;
2664 		new->__use = 1;
2665 		new->input = dst_discard;
2666 		new->output = dst_discard_out;
2667 
2668 		dst_copy_metrics(new, &ort->dst);
2669 
2670 		rt->rt6i_idev = in6_dev_get(loopback_dev);
2671 		rt->rt6i_gateway = ort->rt6i_gateway;
2672 		rt->rt6i_flags = ort->rt6i_flags & ~RTF_PCPU;
2673 
2674 		memcpy(&rt->rt6i_dst, &ort->rt6i_dst, sizeof(struct rt6key));
2675 #ifdef CONFIG_IPV6_SUBTREES
2676 		memcpy(&rt->rt6i_src, &ort->rt6i_src, sizeof(struct rt6key));
2677 #endif
2678 	}
2679 
2680 	dst_release(dst_orig);
2681 	return new ? new : ERR_PTR(-ENOMEM);
2682 }
2683 
2684 /*
2685  *	Destination cache support functions
2686  */
2687 
fib6_check(struct fib6_info * f6i,u32 cookie)2688 static bool fib6_check(struct fib6_info *f6i, u32 cookie)
2689 {
2690 	u32 rt_cookie = 0;
2691 
2692 	if (!fib6_get_cookie_safe(f6i, &rt_cookie) || rt_cookie != cookie)
2693 		return false;
2694 
2695 	if (fib6_check_expired(f6i))
2696 		return false;
2697 
2698 	return true;
2699 }
2700 
rt6_check(struct rt6_info * rt,struct fib6_info * from,u32 cookie)2701 static struct dst_entry *rt6_check(struct rt6_info *rt,
2702 				   struct fib6_info *from,
2703 				   u32 cookie)
2704 {
2705 	u32 rt_cookie = 0;
2706 
2707 	if (!from || !fib6_get_cookie_safe(from, &rt_cookie) ||
2708 	    rt_cookie != cookie)
2709 		return NULL;
2710 
2711 	if (rt6_check_expired(rt))
2712 		return NULL;
2713 
2714 	return &rt->dst;
2715 }
2716 
rt6_dst_from_check(struct rt6_info * rt,struct fib6_info * from,u32 cookie)2717 static struct dst_entry *rt6_dst_from_check(struct rt6_info *rt,
2718 					    struct fib6_info *from,
2719 					    u32 cookie)
2720 {
2721 	if (!__rt6_check_expired(rt) &&
2722 	    rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK &&
2723 	    fib6_check(from, cookie))
2724 		return &rt->dst;
2725 	else
2726 		return NULL;
2727 }
2728 
ip6_dst_check(struct dst_entry * dst,u32 cookie)2729 INDIRECT_CALLABLE_SCOPE struct dst_entry *ip6_dst_check(struct dst_entry *dst,
2730 							u32 cookie)
2731 {
2732 	struct dst_entry *dst_ret;
2733 	struct fib6_info *from;
2734 	struct rt6_info *rt;
2735 
2736 	rt = container_of(dst, struct rt6_info, dst);
2737 
2738 	if (rt->sernum)
2739 		return rt6_is_valid(rt) ? dst : NULL;
2740 
2741 	rcu_read_lock();
2742 
2743 	/* All IPV6 dsts are created with ->obsolete set to the value
2744 	 * DST_OBSOLETE_FORCE_CHK which forces validation calls down
2745 	 * into this function always.
2746 	 */
2747 
2748 	from = rcu_dereference(rt->from);
2749 
2750 	if (from && (rt->rt6i_flags & RTF_PCPU ||
2751 	    unlikely(!list_empty(&rt->rt6i_uncached))))
2752 		dst_ret = rt6_dst_from_check(rt, from, cookie);
2753 	else
2754 		dst_ret = rt6_check(rt, from, cookie);
2755 
2756 	rcu_read_unlock();
2757 
2758 	return dst_ret;
2759 }
2760 EXPORT_INDIRECT_CALLABLE(ip6_dst_check);
2761 
ip6_negative_advice(struct dst_entry * dst)2762 static struct dst_entry *ip6_negative_advice(struct dst_entry *dst)
2763 {
2764 	struct rt6_info *rt = (struct rt6_info *) dst;
2765 
2766 	if (rt) {
2767 		if (rt->rt6i_flags & RTF_CACHE) {
2768 			rcu_read_lock();
2769 			if (rt6_check_expired(rt)) {
2770 				rt6_remove_exception_rt(rt);
2771 				dst = NULL;
2772 			}
2773 			rcu_read_unlock();
2774 		} else {
2775 			dst_release(dst);
2776 			dst = NULL;
2777 		}
2778 	}
2779 	return dst;
2780 }
2781 
ip6_link_failure(struct sk_buff * skb)2782 static void ip6_link_failure(struct sk_buff *skb)
2783 {
2784 	struct rt6_info *rt;
2785 
2786 	icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH, 0);
2787 
2788 	rt = (struct rt6_info *) skb_dst(skb);
2789 	if (rt) {
2790 		rcu_read_lock();
2791 		if (rt->rt6i_flags & RTF_CACHE) {
2792 			rt6_remove_exception_rt(rt);
2793 		} else {
2794 			struct fib6_info *from;
2795 			struct fib6_node *fn;
2796 
2797 			from = rcu_dereference(rt->from);
2798 			if (from) {
2799 				fn = rcu_dereference(from->fib6_node);
2800 				if (fn && (rt->rt6i_flags & RTF_DEFAULT))
2801 					WRITE_ONCE(fn->fn_sernum, -1);
2802 			}
2803 		}
2804 		rcu_read_unlock();
2805 	}
2806 }
2807 
rt6_update_expires(struct rt6_info * rt0,int timeout)2808 static void rt6_update_expires(struct rt6_info *rt0, int timeout)
2809 {
2810 	if (!(rt0->rt6i_flags & RTF_EXPIRES)) {
2811 		struct fib6_info *from;
2812 
2813 		rcu_read_lock();
2814 		from = rcu_dereference(rt0->from);
2815 		if (from)
2816 			rt0->dst.expires = from->expires;
2817 		rcu_read_unlock();
2818 	}
2819 
2820 	dst_set_expires(&rt0->dst, timeout);
2821 	rt0->rt6i_flags |= RTF_EXPIRES;
2822 }
2823 
rt6_do_update_pmtu(struct rt6_info * rt,u32 mtu)2824 static void rt6_do_update_pmtu(struct rt6_info *rt, u32 mtu)
2825 {
2826 	struct net *net = dev_net(rt->dst.dev);
2827 
2828 	dst_metric_set(&rt->dst, RTAX_MTU, mtu);
2829 	rt->rt6i_flags |= RTF_MODIFIED;
2830 	rt6_update_expires(rt, net->ipv6.sysctl.ip6_rt_mtu_expires);
2831 }
2832 
rt6_cache_allowed_for_pmtu(const struct rt6_info * rt)2833 static bool rt6_cache_allowed_for_pmtu(const struct rt6_info *rt)
2834 {
2835 	return !(rt->rt6i_flags & RTF_CACHE) &&
2836 		(rt->rt6i_flags & RTF_PCPU || rcu_access_pointer(rt->from));
2837 }
2838 
__ip6_rt_update_pmtu(struct dst_entry * dst,const struct sock * sk,const struct ipv6hdr * iph,u32 mtu,bool confirm_neigh)2839 static void __ip6_rt_update_pmtu(struct dst_entry *dst, const struct sock *sk,
2840 				 const struct ipv6hdr *iph, u32 mtu,
2841 				 bool confirm_neigh)
2842 {
2843 	const struct in6_addr *daddr, *saddr;
2844 	struct rt6_info *rt6 = (struct rt6_info *)dst;
2845 
2846 	/* Note: do *NOT* check dst_metric_locked(dst, RTAX_MTU)
2847 	 * IPv6 pmtu discovery isn't optional, so 'mtu lock' cannot disable it.
2848 	 * [see also comment in rt6_mtu_change_route()]
2849 	 */
2850 
2851 	if (iph) {
2852 		daddr = &iph->daddr;
2853 		saddr = &iph->saddr;
2854 	} else if (sk) {
2855 		daddr = &sk->sk_v6_daddr;
2856 		saddr = &inet6_sk(sk)->saddr;
2857 	} else {
2858 		daddr = NULL;
2859 		saddr = NULL;
2860 	}
2861 
2862 	if (confirm_neigh)
2863 		dst_confirm_neigh(dst, daddr);
2864 
2865 	if (mtu < IPV6_MIN_MTU)
2866 		return;
2867 	if (mtu >= dst_mtu(dst))
2868 		return;
2869 
2870 	if (!rt6_cache_allowed_for_pmtu(rt6)) {
2871 		rt6_do_update_pmtu(rt6, mtu);
2872 		/* update rt6_ex->stamp for cache */
2873 		if (rt6->rt6i_flags & RTF_CACHE)
2874 			rt6_update_exception_stamp_rt(rt6);
2875 	} else if (daddr) {
2876 		struct fib6_result res = {};
2877 		struct rt6_info *nrt6;
2878 
2879 		rcu_read_lock();
2880 		res.f6i = rcu_dereference(rt6->from);
2881 		if (!res.f6i)
2882 			goto out_unlock;
2883 
2884 		res.fib6_flags = res.f6i->fib6_flags;
2885 		res.fib6_type = res.f6i->fib6_type;
2886 
2887 		if (res.f6i->nh) {
2888 			struct fib6_nh_match_arg arg = {
2889 				.dev = dst->dev,
2890 				.gw = &rt6->rt6i_gateway,
2891 			};
2892 
2893 			nexthop_for_each_fib6_nh(res.f6i->nh,
2894 						 fib6_nh_find_match, &arg);
2895 
2896 			/* fib6_info uses a nexthop that does not have fib6_nh
2897 			 * using the dst->dev + gw. Should be impossible.
2898 			 */
2899 			if (!arg.match)
2900 				goto out_unlock;
2901 
2902 			res.nh = arg.match;
2903 		} else {
2904 			res.nh = res.f6i->fib6_nh;
2905 		}
2906 
2907 		nrt6 = ip6_rt_cache_alloc(&res, daddr, saddr);
2908 		if (nrt6) {
2909 			rt6_do_update_pmtu(nrt6, mtu);
2910 			if (rt6_insert_exception(nrt6, &res))
2911 				dst_release_immediate(&nrt6->dst);
2912 		}
2913 out_unlock:
2914 		rcu_read_unlock();
2915 	}
2916 }
2917 
ip6_rt_update_pmtu(struct dst_entry * dst,struct sock * sk,struct sk_buff * skb,u32 mtu,bool confirm_neigh)2918 static void ip6_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
2919 			       struct sk_buff *skb, u32 mtu,
2920 			       bool confirm_neigh)
2921 {
2922 	__ip6_rt_update_pmtu(dst, sk, skb ? ipv6_hdr(skb) : NULL, mtu,
2923 			     confirm_neigh);
2924 }
2925 
ip6_update_pmtu(struct sk_buff * skb,struct net * net,__be32 mtu,int oif,u32 mark,kuid_t uid)2926 void ip6_update_pmtu(struct sk_buff *skb, struct net *net, __be32 mtu,
2927 		     int oif, u32 mark, kuid_t uid)
2928 {
2929 	const struct ipv6hdr *iph = (struct ipv6hdr *) skb->data;
2930 	struct dst_entry *dst;
2931 	struct flowi6 fl6 = {
2932 		.flowi6_oif = oif,
2933 		.flowi6_mark = mark ? mark : IP6_REPLY_MARK(net, skb->mark),
2934 		.daddr = iph->daddr,
2935 		.saddr = iph->saddr,
2936 		.flowlabel = ip6_flowinfo(iph),
2937 		.flowi6_uid = uid,
2938 	};
2939 
2940 	dst = ip6_route_output(net, NULL, &fl6);
2941 	if (!dst->error)
2942 		__ip6_rt_update_pmtu(dst, NULL, iph, ntohl(mtu), true);
2943 	dst_release(dst);
2944 }
2945 EXPORT_SYMBOL_GPL(ip6_update_pmtu);
2946 
ip6_sk_update_pmtu(struct sk_buff * skb,struct sock * sk,__be32 mtu)2947 void ip6_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, __be32 mtu)
2948 {
2949 	int oif = sk->sk_bound_dev_if;
2950 	struct dst_entry *dst;
2951 
2952 	if (!oif && skb->dev)
2953 		oif = l3mdev_master_ifindex(skb->dev);
2954 
2955 	ip6_update_pmtu(skb, sock_net(sk), mtu, oif, sk->sk_mark, sk->sk_uid);
2956 
2957 	dst = __sk_dst_get(sk);
2958 	if (!dst || !dst->obsolete ||
2959 	    dst->ops->check(dst, inet6_sk(sk)->dst_cookie))
2960 		return;
2961 
2962 	bh_lock_sock(sk);
2963 	if (!sock_owned_by_user(sk) && !ipv6_addr_v4mapped(&sk->sk_v6_daddr))
2964 		ip6_datagram_dst_update(sk, false);
2965 	bh_unlock_sock(sk);
2966 }
2967 EXPORT_SYMBOL_GPL(ip6_sk_update_pmtu);
2968 
ip6_sk_dst_store_flow(struct sock * sk,struct dst_entry * dst,const struct flowi6 * fl6)2969 void ip6_sk_dst_store_flow(struct sock *sk, struct dst_entry *dst,
2970 			   const struct flowi6 *fl6)
2971 {
2972 #ifdef CONFIG_IPV6_SUBTREES
2973 	struct ipv6_pinfo *np = inet6_sk(sk);
2974 #endif
2975 
2976 	ip6_dst_store(sk, dst,
2977 		      ipv6_addr_equal(&fl6->daddr, &sk->sk_v6_daddr) ?
2978 		      &sk->sk_v6_daddr : NULL,
2979 #ifdef CONFIG_IPV6_SUBTREES
2980 		      ipv6_addr_equal(&fl6->saddr, &np->saddr) ?
2981 		      &np->saddr :
2982 #endif
2983 		      NULL);
2984 }
2985 
ip6_redirect_nh_match(const struct fib6_result * res,struct flowi6 * fl6,const struct in6_addr * gw,struct rt6_info ** ret)2986 static bool ip6_redirect_nh_match(const struct fib6_result *res,
2987 				  struct flowi6 *fl6,
2988 				  const struct in6_addr *gw,
2989 				  struct rt6_info **ret)
2990 {
2991 	const struct fib6_nh *nh = res->nh;
2992 
2993 	if (nh->fib_nh_flags & RTNH_F_DEAD || !nh->fib_nh_gw_family ||
2994 	    fl6->flowi6_oif != nh->fib_nh_dev->ifindex)
2995 		return false;
2996 
2997 	/* rt_cache's gateway might be different from its 'parent'
2998 	 * in the case of an ip redirect.
2999 	 * So we keep searching in the exception table if the gateway
3000 	 * is different.
3001 	 */
3002 	if (!ipv6_addr_equal(gw, &nh->fib_nh_gw6)) {
3003 		struct rt6_info *rt_cache;
3004 
3005 		rt_cache = rt6_find_cached_rt(res, &fl6->daddr, &fl6->saddr);
3006 		if (rt_cache &&
3007 		    ipv6_addr_equal(gw, &rt_cache->rt6i_gateway)) {
3008 			*ret = rt_cache;
3009 			return true;
3010 		}
3011 		return false;
3012 	}
3013 	return true;
3014 }
3015 
3016 struct fib6_nh_rd_arg {
3017 	struct fib6_result	*res;
3018 	struct flowi6		*fl6;
3019 	const struct in6_addr	*gw;
3020 	struct rt6_info		**ret;
3021 };
3022 
fib6_nh_redirect_match(struct fib6_nh * nh,void * _arg)3023 static int fib6_nh_redirect_match(struct fib6_nh *nh, void *_arg)
3024 {
3025 	struct fib6_nh_rd_arg *arg = _arg;
3026 
3027 	arg->res->nh = nh;
3028 	return ip6_redirect_nh_match(arg->res, arg->fl6, arg->gw, arg->ret);
3029 }
3030 
3031 /* Handle redirects */
3032 struct ip6rd_flowi {
3033 	struct flowi6 fl6;
3034 	struct in6_addr gateway;
3035 };
3036 
__ip6_route_redirect(struct net * net,struct fib6_table * table,struct flowi6 * fl6,const struct sk_buff * skb,int flags)3037 INDIRECT_CALLABLE_SCOPE struct rt6_info *__ip6_route_redirect(struct net *net,
3038 					     struct fib6_table *table,
3039 					     struct flowi6 *fl6,
3040 					     const struct sk_buff *skb,
3041 					     int flags)
3042 {
3043 	struct ip6rd_flowi *rdfl = (struct ip6rd_flowi *)fl6;
3044 	struct rt6_info *ret = NULL;
3045 	struct fib6_result res = {};
3046 	struct fib6_nh_rd_arg arg = {
3047 		.res = &res,
3048 		.fl6 = fl6,
3049 		.gw  = &rdfl->gateway,
3050 		.ret = &ret
3051 	};
3052 	struct fib6_info *rt;
3053 	struct fib6_node *fn;
3054 
3055 	/* Get the "current" route for this destination and
3056 	 * check if the redirect has come from appropriate router.
3057 	 *
3058 	 * RFC 4861 specifies that redirects should only be
3059 	 * accepted if they come from the nexthop to the target.
3060 	 * Due to the way the routes are chosen, this notion
3061 	 * is a bit fuzzy and one might need to check all possible
3062 	 * routes.
3063 	 */
3064 
3065 	rcu_read_lock();
3066 	fn = fib6_node_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr);
3067 restart:
3068 	for_each_fib6_node_rt_rcu(fn) {
3069 		res.f6i = rt;
3070 		if (fib6_check_expired(rt))
3071 			continue;
3072 		if (rt->fib6_flags & RTF_REJECT)
3073 			break;
3074 		if (unlikely(rt->nh)) {
3075 			if (nexthop_is_blackhole(rt->nh))
3076 				continue;
3077 			/* on match, res->nh is filled in and potentially ret */
3078 			if (nexthop_for_each_fib6_nh(rt->nh,
3079 						     fib6_nh_redirect_match,
3080 						     &arg))
3081 				goto out;
3082 		} else {
3083 			res.nh = rt->fib6_nh;
3084 			if (ip6_redirect_nh_match(&res, fl6, &rdfl->gateway,
3085 						  &ret))
3086 				goto out;
3087 		}
3088 	}
3089 
3090 	if (!rt)
3091 		rt = net->ipv6.fib6_null_entry;
3092 	else if (rt->fib6_flags & RTF_REJECT) {
3093 		ret = net->ipv6.ip6_null_entry;
3094 		goto out;
3095 	}
3096 
3097 	if (rt == net->ipv6.fib6_null_entry) {
3098 		fn = fib6_backtrack(fn, &fl6->saddr);
3099 		if (fn)
3100 			goto restart;
3101 	}
3102 
3103 	res.f6i = rt;
3104 	res.nh = rt->fib6_nh;
3105 out:
3106 	if (ret) {
3107 		ip6_hold_safe(net, &ret);
3108 	} else {
3109 		res.fib6_flags = res.f6i->fib6_flags;
3110 		res.fib6_type = res.f6i->fib6_type;
3111 		ret = ip6_create_rt_rcu(&res);
3112 	}
3113 
3114 	rcu_read_unlock();
3115 
3116 	trace_fib6_table_lookup(net, &res, table, fl6);
3117 	return ret;
3118 };
3119 
ip6_route_redirect(struct net * net,const struct flowi6 * fl6,const struct sk_buff * skb,const struct in6_addr * gateway)3120 static struct dst_entry *ip6_route_redirect(struct net *net,
3121 					    const struct flowi6 *fl6,
3122 					    const struct sk_buff *skb,
3123 					    const struct in6_addr *gateway)
3124 {
3125 	int flags = RT6_LOOKUP_F_HAS_SADDR;
3126 	struct ip6rd_flowi rdfl;
3127 
3128 	rdfl.fl6 = *fl6;
3129 	rdfl.gateway = *gateway;
3130 
3131 	return fib6_rule_lookup(net, &rdfl.fl6, skb,
3132 				flags, __ip6_route_redirect);
3133 }
3134 
ip6_redirect(struct sk_buff * skb,struct net * net,int oif,u32 mark,kuid_t uid)3135 void ip6_redirect(struct sk_buff *skb, struct net *net, int oif, u32 mark,
3136 		  kuid_t uid)
3137 {
3138 	const struct ipv6hdr *iph = (struct ipv6hdr *) skb->data;
3139 	struct dst_entry *dst;
3140 	struct flowi6 fl6 = {
3141 		.flowi6_iif = LOOPBACK_IFINDEX,
3142 		.flowi6_oif = oif,
3143 		.flowi6_mark = mark,
3144 		.daddr = iph->daddr,
3145 		.saddr = iph->saddr,
3146 		.flowlabel = ip6_flowinfo(iph),
3147 		.flowi6_uid = uid,
3148 	};
3149 
3150 	dst = ip6_route_redirect(net, &fl6, skb, &ipv6_hdr(skb)->saddr);
3151 	rt6_do_redirect(dst, NULL, skb);
3152 	dst_release(dst);
3153 }
3154 EXPORT_SYMBOL_GPL(ip6_redirect);
3155 
ip6_redirect_no_header(struct sk_buff * skb,struct net * net,int oif)3156 void ip6_redirect_no_header(struct sk_buff *skb, struct net *net, int oif)
3157 {
3158 	const struct ipv6hdr *iph = ipv6_hdr(skb);
3159 	const struct rd_msg *msg = (struct rd_msg *)icmp6_hdr(skb);
3160 	struct dst_entry *dst;
3161 	struct flowi6 fl6 = {
3162 		.flowi6_iif = LOOPBACK_IFINDEX,
3163 		.flowi6_oif = oif,
3164 		.daddr = msg->dest,
3165 		.saddr = iph->daddr,
3166 		.flowi6_uid = sock_net_uid(net, NULL),
3167 	};
3168 
3169 	dst = ip6_route_redirect(net, &fl6, skb, &iph->saddr);
3170 	rt6_do_redirect(dst, NULL, skb);
3171 	dst_release(dst);
3172 }
3173 
ip6_sk_redirect(struct sk_buff * skb,struct sock * sk)3174 void ip6_sk_redirect(struct sk_buff *skb, struct sock *sk)
3175 {
3176 	ip6_redirect(skb, sock_net(sk), sk->sk_bound_dev_if, sk->sk_mark,
3177 		     sk->sk_uid);
3178 }
3179 EXPORT_SYMBOL_GPL(ip6_sk_redirect);
3180 
ip6_default_advmss(const struct dst_entry * dst)3181 static unsigned int ip6_default_advmss(const struct dst_entry *dst)
3182 {
3183 	struct net_device *dev = dst->dev;
3184 	unsigned int mtu = dst_mtu(dst);
3185 	struct net *net = dev_net(dev);
3186 
3187 	mtu -= sizeof(struct ipv6hdr) + sizeof(struct tcphdr);
3188 
3189 	if (mtu < net->ipv6.sysctl.ip6_rt_min_advmss)
3190 		mtu = net->ipv6.sysctl.ip6_rt_min_advmss;
3191 
3192 	/*
3193 	 * Maximal non-jumbo IPv6 payload is IPV6_MAXPLEN and
3194 	 * corresponding MSS is IPV6_MAXPLEN - tcp_header_size.
3195 	 * IPV6_MAXPLEN is also valid and means: "any MSS,
3196 	 * rely only on pmtu discovery"
3197 	 */
3198 	if (mtu > IPV6_MAXPLEN - sizeof(struct tcphdr))
3199 		mtu = IPV6_MAXPLEN;
3200 	return mtu;
3201 }
3202 
ip6_mtu(const struct dst_entry * dst)3203 INDIRECT_CALLABLE_SCOPE unsigned int ip6_mtu(const struct dst_entry *dst)
3204 {
3205 	return ip6_dst_mtu_maybe_forward(dst, false);
3206 }
3207 EXPORT_INDIRECT_CALLABLE(ip6_mtu);
3208 
3209 /* MTU selection:
3210  * 1. mtu on route is locked - use it
3211  * 2. mtu from nexthop exception
3212  * 3. mtu from egress device
3213  *
3214  * based on ip6_dst_mtu_forward and exception logic of
3215  * rt6_find_cached_rt; called with rcu_read_lock
3216  */
ip6_mtu_from_fib6(const struct fib6_result * res,const struct in6_addr * daddr,const struct in6_addr * saddr)3217 u32 ip6_mtu_from_fib6(const struct fib6_result *res,
3218 		      const struct in6_addr *daddr,
3219 		      const struct in6_addr *saddr)
3220 {
3221 	const struct fib6_nh *nh = res->nh;
3222 	struct fib6_info *f6i = res->f6i;
3223 	struct inet6_dev *idev;
3224 	struct rt6_info *rt;
3225 	u32 mtu = 0;
3226 
3227 	if (unlikely(fib6_metric_locked(f6i, RTAX_MTU))) {
3228 		mtu = f6i->fib6_pmtu;
3229 		if (mtu)
3230 			goto out;
3231 	}
3232 
3233 	rt = rt6_find_cached_rt(res, daddr, saddr);
3234 	if (unlikely(rt)) {
3235 		mtu = dst_metric_raw(&rt->dst, RTAX_MTU);
3236 	} else {
3237 		struct net_device *dev = nh->fib_nh_dev;
3238 
3239 		mtu = IPV6_MIN_MTU;
3240 		idev = __in6_dev_get(dev);
3241 		if (idev && idev->cnf.mtu6 > mtu)
3242 			mtu = idev->cnf.mtu6;
3243 	}
3244 
3245 	mtu = min_t(unsigned int, mtu, IP6_MAX_MTU);
3246 out:
3247 	return mtu - lwtunnel_headroom(nh->fib_nh_lws, mtu);
3248 }
3249 
icmp6_dst_alloc(struct net_device * dev,struct flowi6 * fl6)3250 struct dst_entry *icmp6_dst_alloc(struct net_device *dev,
3251 				  struct flowi6 *fl6)
3252 {
3253 	struct dst_entry *dst;
3254 	struct rt6_info *rt;
3255 	struct inet6_dev *idev = in6_dev_get(dev);
3256 	struct net *net = dev_net(dev);
3257 
3258 	if (unlikely(!idev))
3259 		return ERR_PTR(-ENODEV);
3260 
3261 	rt = ip6_dst_alloc(net, dev, 0);
3262 	if (unlikely(!rt)) {
3263 		in6_dev_put(idev);
3264 		dst = ERR_PTR(-ENOMEM);
3265 		goto out;
3266 	}
3267 
3268 	rt->dst.input = ip6_input;
3269 	rt->dst.output  = ip6_output;
3270 	rt->rt6i_gateway  = fl6->daddr;
3271 	rt->rt6i_dst.addr = fl6->daddr;
3272 	rt->rt6i_dst.plen = 128;
3273 	rt->rt6i_idev     = idev;
3274 	dst_metric_set(&rt->dst, RTAX_HOPLIMIT, 0);
3275 
3276 	/* Add this dst into uncached_list so that rt6_disable_ip() can
3277 	 * do proper release of the net_device
3278 	 */
3279 	rt6_uncached_list_add(rt);
3280 
3281 	dst = xfrm_lookup(net, &rt->dst, flowi6_to_flowi(fl6), NULL, 0);
3282 
3283 out:
3284 	return dst;
3285 }
3286 
ip6_dst_gc(struct dst_ops * ops)3287 static int ip6_dst_gc(struct dst_ops *ops)
3288 {
3289 	struct net *net = container_of(ops, struct net, ipv6.ip6_dst_ops);
3290 	int rt_min_interval = net->ipv6.sysctl.ip6_rt_gc_min_interval;
3291 	int rt_max_size = net->ipv6.sysctl.ip6_rt_max_size;
3292 	int rt_elasticity = net->ipv6.sysctl.ip6_rt_gc_elasticity;
3293 	int rt_gc_timeout = net->ipv6.sysctl.ip6_rt_gc_timeout;
3294 	unsigned long rt_last_gc = net->ipv6.ip6_rt_last_gc;
3295 	unsigned int val;
3296 	int entries;
3297 
3298 	entries = dst_entries_get_fast(ops);
3299 	if (entries > rt_max_size)
3300 		entries = dst_entries_get_slow(ops);
3301 
3302 	if (time_after(rt_last_gc + rt_min_interval, jiffies) &&
3303 	    entries <= rt_max_size)
3304 		goto out;
3305 
3306 	fib6_run_gc(atomic_inc_return(&net->ipv6.ip6_rt_gc_expire), net, true);
3307 	entries = dst_entries_get_slow(ops);
3308 	if (entries < ops->gc_thresh)
3309 		atomic_set(&net->ipv6.ip6_rt_gc_expire, rt_gc_timeout >> 1);
3310 out:
3311 	val = atomic_read(&net->ipv6.ip6_rt_gc_expire);
3312 	atomic_set(&net->ipv6.ip6_rt_gc_expire, val - (val >> rt_elasticity));
3313 	return entries > rt_max_size;
3314 }
3315 
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)3316 static int ip6_nh_lookup_table(struct net *net, struct fib6_config *cfg,
3317 			       const struct in6_addr *gw_addr, u32 tbid,
3318 			       int flags, struct fib6_result *res)
3319 {
3320 	struct flowi6 fl6 = {
3321 		.flowi6_oif = cfg->fc_ifindex,
3322 		.daddr = *gw_addr,
3323 		.saddr = cfg->fc_prefsrc,
3324 	};
3325 	struct fib6_table *table;
3326 	int err;
3327 
3328 	table = fib6_get_table(net, tbid);
3329 	if (!table)
3330 		return -EINVAL;
3331 
3332 	if (!ipv6_addr_any(&cfg->fc_prefsrc))
3333 		flags |= RT6_LOOKUP_F_HAS_SADDR;
3334 
3335 	flags |= RT6_LOOKUP_F_IGNORE_LINKSTATE;
3336 
3337 	err = fib6_table_lookup(net, table, cfg->fc_ifindex, &fl6, res, flags);
3338 	if (!err && res->f6i != net->ipv6.fib6_null_entry)
3339 		fib6_select_path(net, res, &fl6, cfg->fc_ifindex,
3340 				 cfg->fc_ifindex != 0, NULL, flags);
3341 
3342 	return err;
3343 }
3344 
ip6_route_check_nh_onlink(struct net * net,struct fib6_config * cfg,const struct net_device * dev,struct netlink_ext_ack * extack)3345 static int ip6_route_check_nh_onlink(struct net *net,
3346 				     struct fib6_config *cfg,
3347 				     const struct net_device *dev,
3348 				     struct netlink_ext_ack *extack)
3349 {
3350 	u32 tbid = l3mdev_fib_table_rcu(dev) ? : RT_TABLE_MAIN;
3351 	const struct in6_addr *gw_addr = &cfg->fc_gateway;
3352 	struct fib6_result res = {};
3353 	int err;
3354 
3355 	err = ip6_nh_lookup_table(net, cfg, gw_addr, tbid, 0, &res);
3356 	if (!err && !(res.fib6_flags & RTF_REJECT) &&
3357 	    /* ignore match if it is the default route */
3358 	    !ipv6_addr_any(&res.f6i->fib6_dst.addr) &&
3359 	    (res.fib6_type != RTN_UNICAST || dev != res.nh->fib_nh_dev)) {
3360 		NL_SET_ERR_MSG(extack,
3361 			       "Nexthop has invalid gateway or device mismatch");
3362 		err = -EINVAL;
3363 	}
3364 
3365 	return err;
3366 }
3367 
ip6_route_check_nh(struct net * net,struct fib6_config * cfg,struct net_device ** _dev,struct inet6_dev ** idev)3368 static int ip6_route_check_nh(struct net *net,
3369 			      struct fib6_config *cfg,
3370 			      struct net_device **_dev,
3371 			      struct inet6_dev **idev)
3372 {
3373 	const struct in6_addr *gw_addr = &cfg->fc_gateway;
3374 	struct net_device *dev = _dev ? *_dev : NULL;
3375 	int flags = RT6_LOOKUP_F_IFACE;
3376 	struct fib6_result res = {};
3377 	int err = -EHOSTUNREACH;
3378 
3379 	if (cfg->fc_table) {
3380 		err = ip6_nh_lookup_table(net, cfg, gw_addr,
3381 					  cfg->fc_table, flags, &res);
3382 		/* gw_addr can not require a gateway or resolve to a reject
3383 		 * route. If a device is given, it must match the result.
3384 		 */
3385 		if (err || res.fib6_flags & RTF_REJECT ||
3386 		    res.nh->fib_nh_gw_family ||
3387 		    (dev && dev != res.nh->fib_nh_dev))
3388 			err = -EHOSTUNREACH;
3389 	}
3390 
3391 	if (err < 0) {
3392 		struct flowi6 fl6 = {
3393 			.flowi6_oif = cfg->fc_ifindex,
3394 			.daddr = *gw_addr,
3395 		};
3396 
3397 		err = fib6_lookup(net, cfg->fc_ifindex, &fl6, &res, flags);
3398 		if (err || res.fib6_flags & RTF_REJECT ||
3399 		    res.nh->fib_nh_gw_family)
3400 			err = -EHOSTUNREACH;
3401 
3402 		if (err)
3403 			return err;
3404 
3405 		fib6_select_path(net, &res, &fl6, cfg->fc_ifindex,
3406 				 cfg->fc_ifindex != 0, NULL, flags);
3407 	}
3408 
3409 	err = 0;
3410 	if (dev) {
3411 		if (dev != res.nh->fib_nh_dev)
3412 			err = -EHOSTUNREACH;
3413 	} else {
3414 		*_dev = dev = res.nh->fib_nh_dev;
3415 		dev_hold(dev);
3416 		*idev = in6_dev_get(dev);
3417 	}
3418 
3419 	return err;
3420 }
3421 
ip6_validate_gw(struct net * net,struct fib6_config * cfg,struct net_device ** _dev,struct inet6_dev ** idev,struct netlink_ext_ack * extack)3422 static int ip6_validate_gw(struct net *net, struct fib6_config *cfg,
3423 			   struct net_device **_dev, struct inet6_dev **idev,
3424 			   struct netlink_ext_ack *extack)
3425 {
3426 	const struct in6_addr *gw_addr = &cfg->fc_gateway;
3427 	int gwa_type = ipv6_addr_type(gw_addr);
3428 	bool skip_dev = gwa_type & IPV6_ADDR_LINKLOCAL ? false : true;
3429 	const struct net_device *dev = *_dev;
3430 	bool need_addr_check = !dev;
3431 	int err = -EINVAL;
3432 
3433 	/* if gw_addr is local we will fail to detect this in case
3434 	 * address is still TENTATIVE (DAD in progress). rt6_lookup()
3435 	 * will return already-added prefix route via interface that
3436 	 * prefix route was assigned to, which might be non-loopback.
3437 	 */
3438 	if (dev &&
3439 	    ipv6_chk_addr_and_flags(net, gw_addr, dev, skip_dev, 0, 0)) {
3440 		NL_SET_ERR_MSG(extack, "Gateway can not be a local address");
3441 		goto out;
3442 	}
3443 
3444 	if (gwa_type != (IPV6_ADDR_LINKLOCAL | IPV6_ADDR_UNICAST)) {
3445 		/* IPv6 strictly inhibits using not link-local
3446 		 * addresses as nexthop address.
3447 		 * Otherwise, router will not able to send redirects.
3448 		 * It is very good, but in some (rare!) circumstances
3449 		 * (SIT, PtP, NBMA NOARP links) it is handy to allow
3450 		 * some exceptions. --ANK
3451 		 * We allow IPv4-mapped nexthops to support RFC4798-type
3452 		 * addressing
3453 		 */
3454 		if (!(gwa_type & (IPV6_ADDR_UNICAST | IPV6_ADDR_MAPPED))) {
3455 			NL_SET_ERR_MSG(extack, "Invalid gateway address");
3456 			goto out;
3457 		}
3458 
3459 		rcu_read_lock();
3460 
3461 		if (cfg->fc_flags & RTNH_F_ONLINK)
3462 			err = ip6_route_check_nh_onlink(net, cfg, dev, extack);
3463 		else
3464 			err = ip6_route_check_nh(net, cfg, _dev, idev);
3465 
3466 		rcu_read_unlock();
3467 
3468 		if (err)
3469 			goto out;
3470 	}
3471 
3472 	/* reload in case device was changed */
3473 	dev = *_dev;
3474 
3475 	err = -EINVAL;
3476 	if (!dev) {
3477 		NL_SET_ERR_MSG(extack, "Egress device not specified");
3478 		goto out;
3479 	} else if (dev->flags & IFF_LOOPBACK) {
3480 		NL_SET_ERR_MSG(extack,
3481 			       "Egress device can not be loopback device for this route");
3482 		goto out;
3483 	}
3484 
3485 	/* if we did not check gw_addr above, do so now that the
3486 	 * egress device has been resolved.
3487 	 */
3488 	if (need_addr_check &&
3489 	    ipv6_chk_addr_and_flags(net, gw_addr, dev, skip_dev, 0, 0)) {
3490 		NL_SET_ERR_MSG(extack, "Gateway can not be a local address");
3491 		goto out;
3492 	}
3493 
3494 	err = 0;
3495 out:
3496 	return err;
3497 }
3498 
fib6_is_reject(u32 flags,struct net_device * dev,int addr_type)3499 static bool fib6_is_reject(u32 flags, struct net_device *dev, int addr_type)
3500 {
3501 	if ((flags & RTF_REJECT) ||
3502 	    (dev && (dev->flags & IFF_LOOPBACK) &&
3503 	     !(addr_type & IPV6_ADDR_LOOPBACK) &&
3504 	     !(flags & (RTF_ANYCAST | RTF_LOCAL))))
3505 		return true;
3506 
3507 	return false;
3508 }
3509 
fib6_nh_init(struct net * net,struct fib6_nh * fib6_nh,struct fib6_config * cfg,gfp_t gfp_flags,struct netlink_ext_ack * extack)3510 int fib6_nh_init(struct net *net, struct fib6_nh *fib6_nh,
3511 		 struct fib6_config *cfg, gfp_t gfp_flags,
3512 		 struct netlink_ext_ack *extack)
3513 {
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 = dev_get_by_index(net, cfg->fc_ifindex);
3532 		if (!dev)
3533 			goto out;
3534 		idev = in6_dev_get(dev);
3535 		if (!idev)
3536 			goto out;
3537 	}
3538 
3539 	if (cfg->fc_flags & RTNH_F_ONLINK) {
3540 		if (!dev) {
3541 			NL_SET_ERR_MSG(extack,
3542 				       "Nexthop device required for onlink");
3543 			goto out;
3544 		}
3545 
3546 		if (!(dev->flags & IFF_UP)) {
3547 			NL_SET_ERR_MSG(extack, "Nexthop device is not up");
3548 			err = -ENETDOWN;
3549 			goto out;
3550 		}
3551 
3552 		fib6_nh->fib_nh_flags |= RTNH_F_ONLINK;
3553 	}
3554 
3555 	fib6_nh->fib_nh_weight = 1;
3556 
3557 	/* We cannot add true routes via loopback here,
3558 	 * they would result in kernel looping; promote them to reject routes
3559 	 */
3560 	addr_type = ipv6_addr_type(&cfg->fc_dst);
3561 	if (fib6_is_reject(cfg->fc_flags, dev, addr_type)) {
3562 		/* hold loopback dev/idev if we haven't done so. */
3563 		if (dev != net->loopback_dev) {
3564 			if (dev) {
3565 				dev_put(dev);
3566 				in6_dev_put(idev);
3567 			}
3568 			dev = net->loopback_dev;
3569 			dev_hold(dev);
3570 			idev = in6_dev_get(dev);
3571 			if (!idev) {
3572 				err = -ENODEV;
3573 				goto out;
3574 			}
3575 		}
3576 		goto pcpu_alloc;
3577 	}
3578 
3579 	if (cfg->fc_flags & RTF_GATEWAY) {
3580 		err = ip6_validate_gw(net, cfg, &dev, &idev, extack);
3581 		if (err)
3582 			goto out;
3583 
3584 		fib6_nh->fib_nh_gw6 = cfg->fc_gateway;
3585 		fib6_nh->fib_nh_gw_family = AF_INET6;
3586 	}
3587 
3588 	err = -ENODEV;
3589 	if (!dev)
3590 		goto out;
3591 
3592 	if (idev->cnf.disable_ipv6) {
3593 		NL_SET_ERR_MSG(extack, "IPv6 is disabled on nexthop device");
3594 		err = -EACCES;
3595 		goto out;
3596 	}
3597 
3598 	if (!(dev->flags & IFF_UP) && !cfg->fc_ignore_dev_down) {
3599 		NL_SET_ERR_MSG(extack, "Nexthop device is not up");
3600 		err = -ENETDOWN;
3601 		goto out;
3602 	}
3603 
3604 	if (!(cfg->fc_flags & (RTF_LOCAL | RTF_ANYCAST)) &&
3605 	    !netif_carrier_ok(dev))
3606 		fib6_nh->fib_nh_flags |= RTNH_F_LINKDOWN;
3607 
3608 	err = fib_nh_common_init(net, &fib6_nh->nh_common, cfg->fc_encap,
3609 				 cfg->fc_encap_type, cfg, gfp_flags, extack);
3610 	if (err)
3611 		goto out;
3612 
3613 pcpu_alloc:
3614 	fib6_nh->rt6i_pcpu = alloc_percpu_gfp(struct rt6_info *, gfp_flags);
3615 	if (!fib6_nh->rt6i_pcpu) {
3616 		err = -ENOMEM;
3617 		goto out;
3618 	}
3619 
3620 	fib6_nh->fib_nh_dev = dev;
3621 	netdev_tracker_alloc(dev, &fib6_nh->fib_nh_dev_tracker, gfp_flags);
3622 
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 		dev_put(dev);
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)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 {
4551 	struct fib6_config cfg = {
4552 		.fc_table = l3mdev_fib_table(idev->dev) ? : RT6_TABLE_LOCAL,
4553 		.fc_ifindex = idev->dev->ifindex,
4554 		.fc_flags = RTF_UP | RTF_NONEXTHOP,
4555 		.fc_dst = *addr,
4556 		.fc_dst_len = 128,
4557 		.fc_protocol = RTPROT_KERNEL,
4558 		.fc_nlinfo.nl_net = net,
4559 		.fc_ignore_dev_down = true,
4560 	};
4561 	struct fib6_info *f6i;
4562 
4563 	if (anycast) {
4564 		cfg.fc_type = RTN_ANYCAST;
4565 		cfg.fc_flags |= RTF_ANYCAST;
4566 	} else {
4567 		cfg.fc_type = RTN_LOCAL;
4568 		cfg.fc_flags |= RTF_LOCAL;
4569 	}
4570 
4571 	f6i = ip6_route_info_create(&cfg, gfp_flags, NULL);
4572 	if (!IS_ERR(f6i)) {
4573 		f6i->dst_nocount = true;
4574 
4575 		if (!anycast &&
4576 		    (net->ipv6.devconf_all->disable_policy ||
4577 		     idev->cnf.disable_policy))
4578 			f6i->dst_nopolicy = true;
4579 	}
4580 
4581 	return f6i;
4582 }
4583 
4584 /* remove deleted ip from prefsrc entries */
4585 struct arg_dev_net_ip {
4586 	struct net_device *dev;
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_device *dev = ((struct arg_dev_net_ip *)arg)->dev;
4594 	struct net *net = ((struct arg_dev_net_ip *)arg)->net;
4595 	struct in6_addr *addr = ((struct arg_dev_net_ip *)arg)->addr;
4596 
4597 	if (!rt->nh &&
4598 	    ((void *)rt->fib6_nh->fib_nh_dev == dev || !dev) &&
4599 	    rt != net->ipv6.fib6_null_entry &&
4600 	    ipv6_addr_equal(addr, &rt->fib6_prefsrc.addr)) {
4601 		spin_lock_bh(&rt6_exception_lock);
4602 		/* remove prefsrc entry */
4603 		rt->fib6_prefsrc.plen = 0;
4604 		spin_unlock_bh(&rt6_exception_lock);
4605 	}
4606 	return 0;
4607 }
4608 
rt6_remove_prefsrc(struct inet6_ifaddr * ifp)4609 void rt6_remove_prefsrc(struct inet6_ifaddr *ifp)
4610 {
4611 	struct net *net = dev_net(ifp->idev->dev);
4612 	struct arg_dev_net_ip adni = {
4613 		.dev = ifp->idev->dev,
4614 		.net = net,
4615 		.addr = &ifp->addr,
4616 	};
4617 	fib6_clean_all(net, fib6_remove_prefsrc, &adni);
4618 }
4619 
4620 #define RTF_RA_ROUTER		(RTF_ADDRCONF | RTF_DEFAULT)
4621 
4622 /* Remove routers and update dst entries when gateway turn into host. */
fib6_clean_tohost(struct fib6_info * rt,void * arg)4623 static int fib6_clean_tohost(struct fib6_info *rt, void *arg)
4624 {
4625 	struct in6_addr *gateway = (struct in6_addr *)arg;
4626 	struct fib6_nh *nh;
4627 
4628 	/* RA routes do not use nexthops */
4629 	if (rt->nh)
4630 		return 0;
4631 
4632 	nh = rt->fib6_nh;
4633 	if (((rt->fib6_flags & RTF_RA_ROUTER) == RTF_RA_ROUTER) &&
4634 	    nh->fib_nh_gw_family && ipv6_addr_equal(gateway, &nh->fib_nh_gw6))
4635 		return -1;
4636 
4637 	/* Further clean up cached routes in exception table.
4638 	 * This is needed because cached route may have a different
4639 	 * gateway than its 'parent' in the case of an ip redirect.
4640 	 */
4641 	fib6_nh_exceptions_clean_tohost(nh, gateway);
4642 
4643 	return 0;
4644 }
4645 
rt6_clean_tohost(struct net * net,struct in6_addr * gateway)4646 void rt6_clean_tohost(struct net *net, struct in6_addr *gateway)
4647 {
4648 	fib6_clean_all(net, fib6_clean_tohost, gateway);
4649 }
4650 
4651 struct arg_netdev_event {
4652 	const struct net_device *dev;
4653 	union {
4654 		unsigned char nh_flags;
4655 		unsigned long event;
4656 	};
4657 };
4658 
rt6_multipath_first_sibling(const struct fib6_info * rt)4659 static struct fib6_info *rt6_multipath_first_sibling(const struct fib6_info *rt)
4660 {
4661 	struct fib6_info *iter;
4662 	struct fib6_node *fn;
4663 
4664 	fn = rcu_dereference_protected(rt->fib6_node,
4665 			lockdep_is_held(&rt->fib6_table->tb6_lock));
4666 	iter = rcu_dereference_protected(fn->leaf,
4667 			lockdep_is_held(&rt->fib6_table->tb6_lock));
4668 	while (iter) {
4669 		if (iter->fib6_metric == rt->fib6_metric &&
4670 		    rt6_qualify_for_ecmp(iter))
4671 			return iter;
4672 		iter = rcu_dereference_protected(iter->fib6_next,
4673 				lockdep_is_held(&rt->fib6_table->tb6_lock));
4674 	}
4675 
4676 	return NULL;
4677 }
4678 
4679 /* only called for fib entries with builtin fib6_nh */
rt6_is_dead(const struct fib6_info * rt)4680 static bool rt6_is_dead(const struct fib6_info *rt)
4681 {
4682 	if (rt->fib6_nh->fib_nh_flags & RTNH_F_DEAD ||
4683 	    (rt->fib6_nh->fib_nh_flags & RTNH_F_LINKDOWN &&
4684 	     ip6_ignore_linkdown(rt->fib6_nh->fib_nh_dev)))
4685 		return true;
4686 
4687 	return false;
4688 }
4689 
rt6_multipath_total_weight(const struct fib6_info * rt)4690 static int rt6_multipath_total_weight(const struct fib6_info *rt)
4691 {
4692 	struct fib6_info *iter;
4693 	int total = 0;
4694 
4695 	if (!rt6_is_dead(rt))
4696 		total += rt->fib6_nh->fib_nh_weight;
4697 
4698 	list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings) {
4699 		if (!rt6_is_dead(iter))
4700 			total += iter->fib6_nh->fib_nh_weight;
4701 	}
4702 
4703 	return total;
4704 }
4705 
rt6_upper_bound_set(struct fib6_info * rt,int * weight,int total)4706 static void rt6_upper_bound_set(struct fib6_info *rt, int *weight, int total)
4707 {
4708 	int upper_bound = -1;
4709 
4710 	if (!rt6_is_dead(rt)) {
4711 		*weight += rt->fib6_nh->fib_nh_weight;
4712 		upper_bound = DIV_ROUND_CLOSEST_ULL((u64) (*weight) << 31,
4713 						    total) - 1;
4714 	}
4715 	atomic_set(&rt->fib6_nh->fib_nh_upper_bound, upper_bound);
4716 }
4717 
rt6_multipath_upper_bound_set(struct fib6_info * rt,int total)4718 static void rt6_multipath_upper_bound_set(struct fib6_info *rt, int total)
4719 {
4720 	struct fib6_info *iter;
4721 	int weight = 0;
4722 
4723 	rt6_upper_bound_set(rt, &weight, total);
4724 
4725 	list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
4726 		rt6_upper_bound_set(iter, &weight, total);
4727 }
4728 
rt6_multipath_rebalance(struct fib6_info * rt)4729 void rt6_multipath_rebalance(struct fib6_info *rt)
4730 {
4731 	struct fib6_info *first;
4732 	int total;
4733 
4734 	/* In case the entire multipath route was marked for flushing,
4735 	 * then there is no need to rebalance upon the removal of every
4736 	 * sibling route.
4737 	 */
4738 	if (!rt->fib6_nsiblings || rt->should_flush)
4739 		return;
4740 
4741 	/* During lookup routes are evaluated in order, so we need to
4742 	 * make sure upper bounds are assigned from the first sibling
4743 	 * onwards.
4744 	 */
4745 	first = rt6_multipath_first_sibling(rt);
4746 	if (WARN_ON_ONCE(!first))
4747 		return;
4748 
4749 	total = rt6_multipath_total_weight(first);
4750 	rt6_multipath_upper_bound_set(first, total);
4751 }
4752 
fib6_ifup(struct fib6_info * rt,void * p_arg)4753 static int fib6_ifup(struct fib6_info *rt, void *p_arg)
4754 {
4755 	const struct arg_netdev_event *arg = p_arg;
4756 	struct net *net = dev_net(arg->dev);
4757 
4758 	if (rt != net->ipv6.fib6_null_entry && !rt->nh &&
4759 	    rt->fib6_nh->fib_nh_dev == arg->dev) {
4760 		rt->fib6_nh->fib_nh_flags &= ~arg->nh_flags;
4761 		fib6_update_sernum_upto_root(net, rt);
4762 		rt6_multipath_rebalance(rt);
4763 	}
4764 
4765 	return 0;
4766 }
4767 
rt6_sync_up(struct net_device * dev,unsigned char nh_flags)4768 void rt6_sync_up(struct net_device *dev, unsigned char nh_flags)
4769 {
4770 	struct arg_netdev_event arg = {
4771 		.dev = dev,
4772 		{
4773 			.nh_flags = nh_flags,
4774 		},
4775 	};
4776 
4777 	if (nh_flags & RTNH_F_DEAD && netif_carrier_ok(dev))
4778 		arg.nh_flags |= RTNH_F_LINKDOWN;
4779 
4780 	fib6_clean_all(dev_net(dev), fib6_ifup, &arg);
4781 }
4782 
4783 /* only called for fib entries with inline fib6_nh */
rt6_multipath_uses_dev(const struct fib6_info * rt,const struct net_device * dev)4784 static bool rt6_multipath_uses_dev(const struct fib6_info *rt,
4785 				   const struct net_device *dev)
4786 {
4787 	struct fib6_info *iter;
4788 
4789 	if (rt->fib6_nh->fib_nh_dev == dev)
4790 		return true;
4791 	list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
4792 		if (iter->fib6_nh->fib_nh_dev == dev)
4793 			return true;
4794 
4795 	return false;
4796 }
4797 
rt6_multipath_flush(struct fib6_info * rt)4798 static void rt6_multipath_flush(struct fib6_info *rt)
4799 {
4800 	struct fib6_info *iter;
4801 
4802 	rt->should_flush = 1;
4803 	list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
4804 		iter->should_flush = 1;
4805 }
4806 
rt6_multipath_dead_count(const struct fib6_info * rt,const struct net_device * down_dev)4807 static unsigned int rt6_multipath_dead_count(const struct fib6_info *rt,
4808 					     const struct net_device *down_dev)
4809 {
4810 	struct fib6_info *iter;
4811 	unsigned int dead = 0;
4812 
4813 	if (rt->fib6_nh->fib_nh_dev == down_dev ||
4814 	    rt->fib6_nh->fib_nh_flags & RTNH_F_DEAD)
4815 		dead++;
4816 	list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
4817 		if (iter->fib6_nh->fib_nh_dev == down_dev ||
4818 		    iter->fib6_nh->fib_nh_flags & RTNH_F_DEAD)
4819 			dead++;
4820 
4821 	return dead;
4822 }
4823 
rt6_multipath_nh_flags_set(struct fib6_info * rt,const struct net_device * dev,unsigned char nh_flags)4824 static void rt6_multipath_nh_flags_set(struct fib6_info *rt,
4825 				       const struct net_device *dev,
4826 				       unsigned char nh_flags)
4827 {
4828 	struct fib6_info *iter;
4829 
4830 	if (rt->fib6_nh->fib_nh_dev == dev)
4831 		rt->fib6_nh->fib_nh_flags |= nh_flags;
4832 	list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
4833 		if (iter->fib6_nh->fib_nh_dev == dev)
4834 			iter->fib6_nh->fib_nh_flags |= nh_flags;
4835 }
4836 
4837 /* called with write lock held for table with rt */
fib6_ifdown(struct fib6_info * rt,void * p_arg)4838 static int fib6_ifdown(struct fib6_info *rt, void *p_arg)
4839 {
4840 	const struct arg_netdev_event *arg = p_arg;
4841 	const struct net_device *dev = arg->dev;
4842 	struct net *net = dev_net(dev);
4843 
4844 	if (rt == net->ipv6.fib6_null_entry || rt->nh)
4845 		return 0;
4846 
4847 	switch (arg->event) {
4848 	case NETDEV_UNREGISTER:
4849 		return rt->fib6_nh->fib_nh_dev == dev ? -1 : 0;
4850 	case NETDEV_DOWN:
4851 		if (rt->should_flush)
4852 			return -1;
4853 		if (!rt->fib6_nsiblings)
4854 			return rt->fib6_nh->fib_nh_dev == dev ? -1 : 0;
4855 		if (rt6_multipath_uses_dev(rt, dev)) {
4856 			unsigned int count;
4857 
4858 			count = rt6_multipath_dead_count(rt, dev);
4859 			if (rt->fib6_nsiblings + 1 == count) {
4860 				rt6_multipath_flush(rt);
4861 				return -1;
4862 			}
4863 			rt6_multipath_nh_flags_set(rt, dev, RTNH_F_DEAD |
4864 						   RTNH_F_LINKDOWN);
4865 			fib6_update_sernum(net, rt);
4866 			rt6_multipath_rebalance(rt);
4867 		}
4868 		return -2;
4869 	case NETDEV_CHANGE:
4870 		if (rt->fib6_nh->fib_nh_dev != dev ||
4871 		    rt->fib6_flags & (RTF_LOCAL | RTF_ANYCAST))
4872 			break;
4873 		rt->fib6_nh->fib_nh_flags |= RTNH_F_LINKDOWN;
4874 		rt6_multipath_rebalance(rt);
4875 		break;
4876 	}
4877 
4878 	return 0;
4879 }
4880 
rt6_sync_down_dev(struct net_device * dev,unsigned long event)4881 void rt6_sync_down_dev(struct net_device *dev, unsigned long event)
4882 {
4883 	struct arg_netdev_event arg = {
4884 		.dev = dev,
4885 		{
4886 			.event = event,
4887 		},
4888 	};
4889 	struct net *net = dev_net(dev);
4890 
4891 	if (net->ipv6.sysctl.skip_notify_on_dev_down)
4892 		fib6_clean_all_skip_notify(net, fib6_ifdown, &arg);
4893 	else
4894 		fib6_clean_all(net, fib6_ifdown, &arg);
4895 }
4896 
rt6_disable_ip(struct net_device * dev,unsigned long event)4897 void rt6_disable_ip(struct net_device *dev, unsigned long event)
4898 {
4899 	rt6_sync_down_dev(dev, event);
4900 	rt6_uncached_list_flush_dev(dev);
4901 	neigh_ifdown(&nd_tbl, dev);
4902 }
4903 
4904 struct rt6_mtu_change_arg {
4905 	struct net_device *dev;
4906 	unsigned int mtu;
4907 	struct fib6_info *f6i;
4908 };
4909 
fib6_nh_mtu_change(struct fib6_nh * nh,void * _arg)4910 static int fib6_nh_mtu_change(struct fib6_nh *nh, void *_arg)
4911 {
4912 	struct rt6_mtu_change_arg *arg = (struct rt6_mtu_change_arg *)_arg;
4913 	struct fib6_info *f6i = arg->f6i;
4914 
4915 	/* For administrative MTU increase, there is no way to discover
4916 	 * IPv6 PMTU increase, so PMTU increase should be updated here.
4917 	 * Since RFC 1981 doesn't include administrative MTU increase
4918 	 * update PMTU increase is a MUST. (i.e. jumbo frame)
4919 	 */
4920 	if (nh->fib_nh_dev == arg->dev) {
4921 		struct inet6_dev *idev = __in6_dev_get(arg->dev);
4922 		u32 mtu = f6i->fib6_pmtu;
4923 
4924 		if (mtu >= arg->mtu ||
4925 		    (mtu < arg->mtu && mtu == idev->cnf.mtu6))
4926 			fib6_metric_set(f6i, RTAX_MTU, arg->mtu);
4927 
4928 		spin_lock_bh(&rt6_exception_lock);
4929 		rt6_exceptions_update_pmtu(idev, nh, arg->mtu);
4930 		spin_unlock_bh(&rt6_exception_lock);
4931 	}
4932 
4933 	return 0;
4934 }
4935 
rt6_mtu_change_route(struct fib6_info * f6i,void * p_arg)4936 static int rt6_mtu_change_route(struct fib6_info *f6i, void *p_arg)
4937 {
4938 	struct rt6_mtu_change_arg *arg = (struct rt6_mtu_change_arg *) p_arg;
4939 	struct inet6_dev *idev;
4940 
4941 	/* In IPv6 pmtu discovery is not optional,
4942 	   so that RTAX_MTU lock cannot disable it.
4943 	   We still use this lock to block changes
4944 	   caused by addrconf/ndisc.
4945 	*/
4946 
4947 	idev = __in6_dev_get(arg->dev);
4948 	if (!idev)
4949 		return 0;
4950 
4951 	if (fib6_metric_locked(f6i, RTAX_MTU))
4952 		return 0;
4953 
4954 	arg->f6i = f6i;
4955 	if (f6i->nh) {
4956 		/* fib6_nh_mtu_change only returns 0, so this is safe */
4957 		return nexthop_for_each_fib6_nh(f6i->nh, fib6_nh_mtu_change,
4958 						arg);
4959 	}
4960 
4961 	return fib6_nh_mtu_change(f6i->fib6_nh, arg);
4962 }
4963 
rt6_mtu_change(struct net_device * dev,unsigned int mtu)4964 void rt6_mtu_change(struct net_device *dev, unsigned int mtu)
4965 {
4966 	struct rt6_mtu_change_arg arg = {
4967 		.dev = dev,
4968 		.mtu = mtu,
4969 	};
4970 
4971 	fib6_clean_all(dev_net(dev), rt6_mtu_change_route, &arg);
4972 }
4973 
4974 static const struct nla_policy rtm_ipv6_policy[RTA_MAX+1] = {
4975 	[RTA_UNSPEC]		= { .strict_start_type = RTA_DPORT + 1 },
4976 	[RTA_GATEWAY]           = { .len = sizeof(struct in6_addr) },
4977 	[RTA_PREFSRC]		= { .len = sizeof(struct in6_addr) },
4978 	[RTA_OIF]               = { .type = NLA_U32 },
4979 	[RTA_IIF]		= { .type = NLA_U32 },
4980 	[RTA_PRIORITY]          = { .type = NLA_U32 },
4981 	[RTA_METRICS]           = { .type = NLA_NESTED },
4982 	[RTA_MULTIPATH]		= { .len = sizeof(struct rtnexthop) },
4983 	[RTA_PREF]              = { .type = NLA_U8 },
4984 	[RTA_ENCAP_TYPE]	= { .type = NLA_U16 },
4985 	[RTA_ENCAP]		= { .type = NLA_NESTED },
4986 	[RTA_EXPIRES]		= { .type = NLA_U32 },
4987 	[RTA_UID]		= { .type = NLA_U32 },
4988 	[RTA_MARK]		= { .type = NLA_U32 },
4989 	[RTA_TABLE]		= { .type = NLA_U32 },
4990 	[RTA_IP_PROTO]		= { .type = NLA_U8 },
4991 	[RTA_SPORT]		= { .type = NLA_U16 },
4992 	[RTA_DPORT]		= { .type = NLA_U16 },
4993 	[RTA_NH_ID]		= { .type = NLA_U32 },
4994 };
4995 
rtm_to_fib6_config(struct sk_buff * skb,struct nlmsghdr * nlh,struct fib6_config * cfg,struct netlink_ext_ack * extack)4996 static int rtm_to_fib6_config(struct sk_buff *skb, struct nlmsghdr *nlh,
4997 			      struct fib6_config *cfg,
4998 			      struct netlink_ext_ack *extack)
4999 {
5000 	struct rtmsg *rtm;
5001 	struct nlattr *tb[RTA_MAX+1];
5002 	unsigned int pref;
5003 	int err;
5004 
5005 	err = nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX,
5006 				     rtm_ipv6_policy, extack);
5007 	if (err < 0)
5008 		goto errout;
5009 
5010 	err = -EINVAL;
5011 	rtm = nlmsg_data(nlh);
5012 
5013 	if (rtm->rtm_tos) {
5014 		NL_SET_ERR_MSG(extack,
5015 			       "Invalid dsfield (tos): option not available for IPv6");
5016 		goto errout;
5017 	}
5018 
5019 	*cfg = (struct fib6_config){
5020 		.fc_table = rtm->rtm_table,
5021 		.fc_dst_len = rtm->rtm_dst_len,
5022 		.fc_src_len = rtm->rtm_src_len,
5023 		.fc_flags = RTF_UP,
5024 		.fc_protocol = rtm->rtm_protocol,
5025 		.fc_type = rtm->rtm_type,
5026 
5027 		.fc_nlinfo.portid = NETLINK_CB(skb).portid,
5028 		.fc_nlinfo.nlh = nlh,
5029 		.fc_nlinfo.nl_net = sock_net(skb->sk),
5030 	};
5031 
5032 	if (rtm->rtm_type == RTN_UNREACHABLE ||
5033 	    rtm->rtm_type == RTN_BLACKHOLE ||
5034 	    rtm->rtm_type == RTN_PROHIBIT ||
5035 	    rtm->rtm_type == RTN_THROW)
5036 		cfg->fc_flags |= RTF_REJECT;
5037 
5038 	if (rtm->rtm_type == RTN_LOCAL)
5039 		cfg->fc_flags |= RTF_LOCAL;
5040 
5041 	if (rtm->rtm_flags & RTM_F_CLONED)
5042 		cfg->fc_flags |= RTF_CACHE;
5043 
5044 	cfg->fc_flags |= (rtm->rtm_flags & RTNH_F_ONLINK);
5045 
5046 	if (tb[RTA_NH_ID]) {
5047 		if (tb[RTA_GATEWAY]   || tb[RTA_OIF] ||
5048 		    tb[RTA_MULTIPATH] || tb[RTA_ENCAP]) {
5049 			NL_SET_ERR_MSG(extack,
5050 				       "Nexthop specification and nexthop id are mutually exclusive");
5051 			goto errout;
5052 		}
5053 		cfg->fc_nh_id = nla_get_u32(tb[RTA_NH_ID]);
5054 	}
5055 
5056 	if (tb[RTA_GATEWAY]) {
5057 		cfg->fc_gateway = nla_get_in6_addr(tb[RTA_GATEWAY]);
5058 		cfg->fc_flags |= RTF_GATEWAY;
5059 	}
5060 	if (tb[RTA_VIA]) {
5061 		NL_SET_ERR_MSG(extack, "IPv6 does not support RTA_VIA attribute");
5062 		goto errout;
5063 	}
5064 
5065 	if (tb[RTA_DST]) {
5066 		int plen = (rtm->rtm_dst_len + 7) >> 3;
5067 
5068 		if (nla_len(tb[RTA_DST]) < plen)
5069 			goto errout;
5070 
5071 		nla_memcpy(&cfg->fc_dst, tb[RTA_DST], plen);
5072 	}
5073 
5074 	if (tb[RTA_SRC]) {
5075 		int plen = (rtm->rtm_src_len + 7) >> 3;
5076 
5077 		if (nla_len(tb[RTA_SRC]) < plen)
5078 			goto errout;
5079 
5080 		nla_memcpy(&cfg->fc_src, tb[RTA_SRC], plen);
5081 	}
5082 
5083 	if (tb[RTA_PREFSRC])
5084 		cfg->fc_prefsrc = nla_get_in6_addr(tb[RTA_PREFSRC]);
5085 
5086 	if (tb[RTA_OIF])
5087 		cfg->fc_ifindex = nla_get_u32(tb[RTA_OIF]);
5088 
5089 	if (tb[RTA_PRIORITY])
5090 		cfg->fc_metric = nla_get_u32(tb[RTA_PRIORITY]);
5091 
5092 	if (tb[RTA_METRICS]) {
5093 		cfg->fc_mx = nla_data(tb[RTA_METRICS]);
5094 		cfg->fc_mx_len = nla_len(tb[RTA_METRICS]);
5095 	}
5096 
5097 	if (tb[RTA_TABLE])
5098 		cfg->fc_table = nla_get_u32(tb[RTA_TABLE]);
5099 
5100 	if (tb[RTA_MULTIPATH]) {
5101 		cfg->fc_mp = nla_data(tb[RTA_MULTIPATH]);
5102 		cfg->fc_mp_len = nla_len(tb[RTA_MULTIPATH]);
5103 
5104 		err = lwtunnel_valid_encap_type_attr(cfg->fc_mp,
5105 						     cfg->fc_mp_len, extack);
5106 		if (err < 0)
5107 			goto errout;
5108 	}
5109 
5110 	if (tb[RTA_PREF]) {
5111 		pref = nla_get_u8(tb[RTA_PREF]);
5112 		if (pref != ICMPV6_ROUTER_PREF_LOW &&
5113 		    pref != ICMPV6_ROUTER_PREF_HIGH)
5114 			pref = ICMPV6_ROUTER_PREF_MEDIUM;
5115 		cfg->fc_flags |= RTF_PREF(pref);
5116 	}
5117 
5118 	if (tb[RTA_ENCAP])
5119 		cfg->fc_encap = tb[RTA_ENCAP];
5120 
5121 	if (tb[RTA_ENCAP_TYPE]) {
5122 		cfg->fc_encap_type = nla_get_u16(tb[RTA_ENCAP_TYPE]);
5123 
5124 		err = lwtunnel_valid_encap_type(cfg->fc_encap_type, extack);
5125 		if (err < 0)
5126 			goto errout;
5127 	}
5128 
5129 	if (tb[RTA_EXPIRES]) {
5130 		unsigned long timeout = addrconf_timeout_fixup(nla_get_u32(tb[RTA_EXPIRES]), HZ);
5131 
5132 		if (addrconf_finite_timeout(timeout)) {
5133 			cfg->fc_expires = jiffies_to_clock_t(timeout * HZ);
5134 			cfg->fc_flags |= RTF_EXPIRES;
5135 		}
5136 	}
5137 
5138 	err = 0;
5139 errout:
5140 	return err;
5141 }
5142 
5143 struct rt6_nh {
5144 	struct fib6_info *fib6_info;
5145 	struct fib6_config r_cfg;
5146 	struct list_head next;
5147 };
5148 
ip6_route_info_append(struct net * net,struct list_head * rt6_nh_list,struct fib6_info * rt,struct fib6_config * r_cfg)5149 static int ip6_route_info_append(struct net *net,
5150 				 struct list_head *rt6_nh_list,
5151 				 struct fib6_info *rt,
5152 				 struct fib6_config *r_cfg)
5153 {
5154 	struct rt6_nh *nh;
5155 	int err = -EEXIST;
5156 
5157 	list_for_each_entry(nh, rt6_nh_list, next) {
5158 		/* check if fib6_info already exists */
5159 		if (rt6_duplicate_nexthop(nh->fib6_info, rt))
5160 			return err;
5161 	}
5162 
5163 	nh = kzalloc(sizeof(*nh), GFP_KERNEL);
5164 	if (!nh)
5165 		return -ENOMEM;
5166 	nh->fib6_info = rt;
5167 	memcpy(&nh->r_cfg, r_cfg, sizeof(*r_cfg));
5168 	list_add_tail(&nh->next, rt6_nh_list);
5169 
5170 	return 0;
5171 }
5172 
ip6_route_mpath_notify(struct fib6_info * rt,struct fib6_info * rt_last,struct nl_info * info,__u16 nlflags)5173 static void ip6_route_mpath_notify(struct fib6_info *rt,
5174 				   struct fib6_info *rt_last,
5175 				   struct nl_info *info,
5176 				   __u16 nlflags)
5177 {
5178 	/* if this is an APPEND route, then rt points to the first route
5179 	 * inserted and rt_last points to last route inserted. Userspace
5180 	 * wants a consistent dump of the route which starts at the first
5181 	 * nexthop. Since sibling routes are always added at the end of
5182 	 * the list, find the first sibling of the last route appended
5183 	 */
5184 	if ((nlflags & NLM_F_APPEND) && rt_last && rt_last->fib6_nsiblings) {
5185 		rt = list_first_entry(&rt_last->fib6_siblings,
5186 				      struct fib6_info,
5187 				      fib6_siblings);
5188 	}
5189 
5190 	if (rt)
5191 		inet6_rt_notify(RTM_NEWROUTE, rt, info, nlflags);
5192 }
5193 
ip6_route_mpath_should_notify(const struct fib6_info * rt)5194 static bool ip6_route_mpath_should_notify(const struct fib6_info *rt)
5195 {
5196 	bool rt_can_ecmp = rt6_qualify_for_ecmp(rt);
5197 	bool should_notify = false;
5198 	struct fib6_info *leaf;
5199 	struct fib6_node *fn;
5200 
5201 	rcu_read_lock();
5202 	fn = rcu_dereference(rt->fib6_node);
5203 	if (!fn)
5204 		goto out;
5205 
5206 	leaf = rcu_dereference(fn->leaf);
5207 	if (!leaf)
5208 		goto out;
5209 
5210 	if (rt == leaf ||
5211 	    (rt_can_ecmp && rt->fib6_metric == leaf->fib6_metric &&
5212 	     rt6_qualify_for_ecmp(leaf)))
5213 		should_notify = true;
5214 out:
5215 	rcu_read_unlock();
5216 
5217 	return should_notify;
5218 }
5219 
fib6_gw_from_attr(struct in6_addr * gw,struct nlattr * nla,struct netlink_ext_ack * extack)5220 static int fib6_gw_from_attr(struct in6_addr *gw, struct nlattr *nla,
5221 			     struct netlink_ext_ack *extack)
5222 {
5223 	if (nla_len(nla) < sizeof(*gw)) {
5224 		NL_SET_ERR_MSG(extack, "Invalid IPv6 address in RTA_GATEWAY");
5225 		return -EINVAL;
5226 	}
5227 
5228 	*gw = nla_get_in6_addr(nla);
5229 
5230 	return 0;
5231 }
5232 
ip6_route_multipath_add(struct fib6_config * cfg,struct netlink_ext_ack * extack)5233 static int ip6_route_multipath_add(struct fib6_config *cfg,
5234 				   struct netlink_ext_ack *extack)
5235 {
5236 	struct fib6_info *rt_notif = NULL, *rt_last = NULL;
5237 	struct nl_info *info = &cfg->fc_nlinfo;
5238 	struct fib6_config r_cfg;
5239 	struct rtnexthop *rtnh;
5240 	struct fib6_info *rt;
5241 	struct rt6_nh *err_nh;
5242 	struct rt6_nh *nh, *nh_safe;
5243 	__u16 nlflags;
5244 	int remaining;
5245 	int attrlen;
5246 	int err = 1;
5247 	int nhn = 0;
5248 	int replace = (cfg->fc_nlinfo.nlh &&
5249 		       (cfg->fc_nlinfo.nlh->nlmsg_flags & NLM_F_REPLACE));
5250 	LIST_HEAD(rt6_nh_list);
5251 
5252 	nlflags = replace ? NLM_F_REPLACE : NLM_F_CREATE;
5253 	if (info->nlh && info->nlh->nlmsg_flags & NLM_F_APPEND)
5254 		nlflags |= NLM_F_APPEND;
5255 
5256 	remaining = cfg->fc_mp_len;
5257 	rtnh = (struct rtnexthop *)cfg->fc_mp;
5258 
5259 	/* Parse a Multipath Entry and build a list (rt6_nh_list) of
5260 	 * fib6_info structs per nexthop
5261 	 */
5262 	while (rtnh_ok(rtnh, remaining)) {
5263 		memcpy(&r_cfg, cfg, sizeof(*cfg));
5264 		if (rtnh->rtnh_ifindex)
5265 			r_cfg.fc_ifindex = rtnh->rtnh_ifindex;
5266 
5267 		attrlen = rtnh_attrlen(rtnh);
5268 		if (attrlen > 0) {
5269 			struct nlattr *nla, *attrs = rtnh_attrs(rtnh);
5270 
5271 			nla = nla_find(attrs, attrlen, RTA_GATEWAY);
5272 			if (nla) {
5273 				err = fib6_gw_from_attr(&r_cfg.fc_gateway, nla,
5274 							extack);
5275 				if (err)
5276 					goto cleanup;
5277 
5278 				r_cfg.fc_flags |= RTF_GATEWAY;
5279 			}
5280 			r_cfg.fc_encap = nla_find(attrs, attrlen, RTA_ENCAP);
5281 
5282 			/* RTA_ENCAP_TYPE length checked in
5283 			 * lwtunnel_valid_encap_type_attr
5284 			 */
5285 			nla = nla_find(attrs, attrlen, RTA_ENCAP_TYPE);
5286 			if (nla)
5287 				r_cfg.fc_encap_type = nla_get_u16(nla);
5288 		}
5289 
5290 		r_cfg.fc_flags |= (rtnh->rtnh_flags & RTNH_F_ONLINK);
5291 		rt = ip6_route_info_create(&r_cfg, GFP_KERNEL, extack);
5292 		if (IS_ERR(rt)) {
5293 			err = PTR_ERR(rt);
5294 			rt = NULL;
5295 			goto cleanup;
5296 		}
5297 		if (!rt6_qualify_for_ecmp(rt)) {
5298 			err = -EINVAL;
5299 			NL_SET_ERR_MSG(extack,
5300 				       "Device only routes can not be added for IPv6 using the multipath API.");
5301 			fib6_info_release(rt);
5302 			goto cleanup;
5303 		}
5304 
5305 		rt->fib6_nh->fib_nh_weight = rtnh->rtnh_hops + 1;
5306 
5307 		err = ip6_route_info_append(info->nl_net, &rt6_nh_list,
5308 					    rt, &r_cfg);
5309 		if (err) {
5310 			fib6_info_release(rt);
5311 			goto cleanup;
5312 		}
5313 
5314 		rtnh = rtnh_next(rtnh, &remaining);
5315 	}
5316 
5317 	if (list_empty(&rt6_nh_list)) {
5318 		NL_SET_ERR_MSG(extack,
5319 			       "Invalid nexthop configuration - no valid nexthops");
5320 		return -EINVAL;
5321 	}
5322 
5323 	/* for add and replace send one notification with all nexthops.
5324 	 * Skip the notification in fib6_add_rt2node and send one with
5325 	 * the full route when done
5326 	 */
5327 	info->skip_notify = 1;
5328 
5329 	/* For add and replace, send one notification with all nexthops. For
5330 	 * append, send one notification with all appended nexthops.
5331 	 */
5332 	info->skip_notify_kernel = 1;
5333 
5334 	err_nh = NULL;
5335 	list_for_each_entry(nh, &rt6_nh_list, next) {
5336 		err = __ip6_ins_rt(nh->fib6_info, info, extack);
5337 		fib6_info_release(nh->fib6_info);
5338 
5339 		if (!err) {
5340 			/* save reference to last route successfully inserted */
5341 			rt_last = nh->fib6_info;
5342 
5343 			/* save reference to first route for notification */
5344 			if (!rt_notif)
5345 				rt_notif = nh->fib6_info;
5346 		}
5347 
5348 		/* nh->fib6_info is used or freed at this point, reset to NULL*/
5349 		nh->fib6_info = NULL;
5350 		if (err) {
5351 			if (replace && nhn)
5352 				NL_SET_ERR_MSG_MOD(extack,
5353 						   "multipath route replace failed (check consistency of installed routes)");
5354 			err_nh = nh;
5355 			goto add_errout;
5356 		}
5357 
5358 		/* Because each route is added like a single route we remove
5359 		 * these flags after the first nexthop: if there is a collision,
5360 		 * we have already failed to add the first nexthop:
5361 		 * fib6_add_rt2node() has rejected it; when replacing, old
5362 		 * nexthops have been replaced by first new, the rest should
5363 		 * be added to it.
5364 		 */
5365 		if (cfg->fc_nlinfo.nlh) {
5366 			cfg->fc_nlinfo.nlh->nlmsg_flags &= ~(NLM_F_EXCL |
5367 							     NLM_F_REPLACE);
5368 			cfg->fc_nlinfo.nlh->nlmsg_flags |= NLM_F_CREATE;
5369 		}
5370 		nhn++;
5371 	}
5372 
5373 	/* An in-kernel notification should only be sent in case the new
5374 	 * multipath route is added as the first route in the node, or if
5375 	 * it was appended to it. We pass 'rt_notif' since it is the first
5376 	 * sibling and might allow us to skip some checks in the replace case.
5377 	 */
5378 	if (ip6_route_mpath_should_notify(rt_notif)) {
5379 		enum fib_event_type fib_event;
5380 
5381 		if (rt_notif->fib6_nsiblings != nhn - 1)
5382 			fib_event = FIB_EVENT_ENTRY_APPEND;
5383 		else
5384 			fib_event = FIB_EVENT_ENTRY_REPLACE;
5385 
5386 		err = call_fib6_multipath_entry_notifiers(info->nl_net,
5387 							  fib_event, rt_notif,
5388 							  nhn - 1, extack);
5389 		if (err) {
5390 			/* Delete all the siblings that were just added */
5391 			err_nh = NULL;
5392 			goto add_errout;
5393 		}
5394 	}
5395 
5396 	/* success ... tell user about new route */
5397 	ip6_route_mpath_notify(rt_notif, rt_last, info, nlflags);
5398 	goto cleanup;
5399 
5400 add_errout:
5401 	/* send notification for routes that were added so that
5402 	 * the delete notifications sent by ip6_route_del are
5403 	 * coherent
5404 	 */
5405 	if (rt_notif)
5406 		ip6_route_mpath_notify(rt_notif, rt_last, info, nlflags);
5407 
5408 	/* Delete routes that were already added */
5409 	list_for_each_entry(nh, &rt6_nh_list, next) {
5410 		if (err_nh == nh)
5411 			break;
5412 		ip6_route_del(&nh->r_cfg, extack);
5413 	}
5414 
5415 cleanup:
5416 	list_for_each_entry_safe(nh, nh_safe, &rt6_nh_list, next) {
5417 		if (nh->fib6_info)
5418 			fib6_info_release(nh->fib6_info);
5419 		list_del(&nh->next);
5420 		kfree(nh);
5421 	}
5422 
5423 	return err;
5424 }
5425 
ip6_route_multipath_del(struct fib6_config * cfg,struct netlink_ext_ack * extack)5426 static int ip6_route_multipath_del(struct fib6_config *cfg,
5427 				   struct netlink_ext_ack *extack)
5428 {
5429 	struct fib6_config r_cfg;
5430 	struct rtnexthop *rtnh;
5431 	int last_err = 0;
5432 	int remaining;
5433 	int attrlen;
5434 	int err;
5435 
5436 	remaining = cfg->fc_mp_len;
5437 	rtnh = (struct rtnexthop *)cfg->fc_mp;
5438 
5439 	/* Parse a Multipath Entry */
5440 	while (rtnh_ok(rtnh, remaining)) {
5441 		memcpy(&r_cfg, cfg, sizeof(*cfg));
5442 		if (rtnh->rtnh_ifindex)
5443 			r_cfg.fc_ifindex = rtnh->rtnh_ifindex;
5444 
5445 		attrlen = rtnh_attrlen(rtnh);
5446 		if (attrlen > 0) {
5447 			struct nlattr *nla, *attrs = rtnh_attrs(rtnh);
5448 
5449 			nla = nla_find(attrs, attrlen, RTA_GATEWAY);
5450 			if (nla) {
5451 				err = fib6_gw_from_attr(&r_cfg.fc_gateway, nla,
5452 							extack);
5453 				if (err) {
5454 					last_err = err;
5455 					goto next_rtnh;
5456 				}
5457 
5458 				r_cfg.fc_flags |= RTF_GATEWAY;
5459 			}
5460 		}
5461 		err = ip6_route_del(&r_cfg, extack);
5462 		if (err)
5463 			last_err = err;
5464 
5465 next_rtnh:
5466 		rtnh = rtnh_next(rtnh, &remaining);
5467 	}
5468 
5469 	return last_err;
5470 }
5471 
inet6_rtm_delroute(struct sk_buff * skb,struct nlmsghdr * nlh,struct netlink_ext_ack * extack)5472 static int inet6_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh,
5473 			      struct netlink_ext_ack *extack)
5474 {
5475 	struct fib6_config cfg;
5476 	int err;
5477 
5478 	err = rtm_to_fib6_config(skb, nlh, &cfg, extack);
5479 	if (err < 0)
5480 		return err;
5481 
5482 	if (cfg.fc_nh_id &&
5483 	    !nexthop_find_by_id(sock_net(skb->sk), cfg.fc_nh_id)) {
5484 		NL_SET_ERR_MSG(extack, "Nexthop id does not exist");
5485 		return -EINVAL;
5486 	}
5487 
5488 	if (cfg.fc_mp)
5489 		return ip6_route_multipath_del(&cfg, extack);
5490 	else {
5491 		cfg.fc_delete_all_nh = 1;
5492 		return ip6_route_del(&cfg, extack);
5493 	}
5494 }
5495 
inet6_rtm_newroute(struct sk_buff * skb,struct nlmsghdr * nlh,struct netlink_ext_ack * extack)5496 static int inet6_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh,
5497 			      struct netlink_ext_ack *extack)
5498 {
5499 	struct fib6_config cfg;
5500 	int err;
5501 
5502 	err = rtm_to_fib6_config(skb, nlh, &cfg, extack);
5503 	if (err < 0)
5504 		return err;
5505 
5506 	if (cfg.fc_metric == 0)
5507 		cfg.fc_metric = IP6_RT_PRIO_USER;
5508 
5509 	if (cfg.fc_mp)
5510 		return ip6_route_multipath_add(&cfg, extack);
5511 	else
5512 		return ip6_route_add(&cfg, GFP_KERNEL, extack);
5513 }
5514 
5515 /* add the overhead of this fib6_nh to nexthop_len */
rt6_nh_nlmsg_size(struct fib6_nh * nh,void * arg)5516 static int rt6_nh_nlmsg_size(struct fib6_nh *nh, void *arg)
5517 {
5518 	int *nexthop_len = arg;
5519 
5520 	*nexthop_len += nla_total_size(0)	 /* RTA_MULTIPATH */
5521 		     + NLA_ALIGN(sizeof(struct rtnexthop))
5522 		     + nla_total_size(16); /* RTA_GATEWAY */
5523 
5524 	if (nh->fib_nh_lws) {
5525 		/* RTA_ENCAP_TYPE */
5526 		*nexthop_len += lwtunnel_get_encap_size(nh->fib_nh_lws);
5527 		/* RTA_ENCAP */
5528 		*nexthop_len += nla_total_size(2);
5529 	}
5530 
5531 	return 0;
5532 }
5533 
rt6_nlmsg_size(struct fib6_info * f6i)5534 static size_t rt6_nlmsg_size(struct fib6_info *f6i)
5535 {
5536 	int nexthop_len;
5537 
5538 	if (f6i->nh) {
5539 		nexthop_len = nla_total_size(4); /* RTA_NH_ID */
5540 		nexthop_for_each_fib6_nh(f6i->nh, rt6_nh_nlmsg_size,
5541 					 &nexthop_len);
5542 	} else {
5543 		struct fib6_nh *nh = f6i->fib6_nh;
5544 
5545 		nexthop_len = 0;
5546 		if (f6i->fib6_nsiblings) {
5547 			nexthop_len = nla_total_size(0)	 /* RTA_MULTIPATH */
5548 				    + NLA_ALIGN(sizeof(struct rtnexthop))
5549 				    + nla_total_size(16) /* RTA_GATEWAY */
5550 				    + lwtunnel_get_encap_size(nh->fib_nh_lws);
5551 
5552 			nexthop_len *= f6i->fib6_nsiblings;
5553 		}
5554 		nexthop_len += lwtunnel_get_encap_size(nh->fib_nh_lws);
5555 	}
5556 
5557 	return NLMSG_ALIGN(sizeof(struct rtmsg))
5558 	       + nla_total_size(16) /* RTA_SRC */
5559 	       + nla_total_size(16) /* RTA_DST */
5560 	       + nla_total_size(16) /* RTA_GATEWAY */
5561 	       + nla_total_size(16) /* RTA_PREFSRC */
5562 	       + nla_total_size(4) /* RTA_TABLE */
5563 	       + nla_total_size(4) /* RTA_IIF */
5564 	       + nla_total_size(4) /* RTA_OIF */
5565 	       + nla_total_size(4) /* RTA_PRIORITY */
5566 	       + RTAX_MAX * nla_total_size(4) /* RTA_METRICS */
5567 	       + nla_total_size(sizeof(struct rta_cacheinfo))
5568 	       + nla_total_size(TCP_CA_NAME_MAX) /* RTAX_CC_ALGO */
5569 	       + nla_total_size(1) /* RTA_PREF */
5570 	       + nexthop_len;
5571 }
5572 
rt6_fill_node_nexthop(struct sk_buff * skb,struct nexthop * nh,unsigned char * flags)5573 static int rt6_fill_node_nexthop(struct sk_buff *skb, struct nexthop *nh,
5574 				 unsigned char *flags)
5575 {
5576 	if (nexthop_is_multipath(nh)) {
5577 		struct nlattr *mp;
5578 
5579 		mp = nla_nest_start_noflag(skb, RTA_MULTIPATH);
5580 		if (!mp)
5581 			goto nla_put_failure;
5582 
5583 		if (nexthop_mpath_fill_node(skb, nh, AF_INET6))
5584 			goto nla_put_failure;
5585 
5586 		nla_nest_end(skb, mp);
5587 	} else {
5588 		struct fib6_nh *fib6_nh;
5589 
5590 		fib6_nh = nexthop_fib6_nh(nh);
5591 		if (fib_nexthop_info(skb, &fib6_nh->nh_common, AF_INET6,
5592 				     flags, false) < 0)
5593 			goto nla_put_failure;
5594 	}
5595 
5596 	return 0;
5597 
5598 nla_put_failure:
5599 	return -EMSGSIZE;
5600 }
5601 
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)5602 static int rt6_fill_node(struct net *net, struct sk_buff *skb,
5603 			 struct fib6_info *rt, struct dst_entry *dst,
5604 			 struct in6_addr *dest, struct in6_addr *src,
5605 			 int iif, int type, u32 portid, u32 seq,
5606 			 unsigned int flags)
5607 {
5608 	struct rt6_info *rt6 = (struct rt6_info *)dst;
5609 	struct rt6key *rt6_dst, *rt6_src;
5610 	u32 *pmetrics, table, rt6_flags;
5611 	unsigned char nh_flags = 0;
5612 	struct nlmsghdr *nlh;
5613 	struct rtmsg *rtm;
5614 	long expires = 0;
5615 
5616 	nlh = nlmsg_put(skb, portid, seq, type, sizeof(*rtm), flags);
5617 	if (!nlh)
5618 		return -EMSGSIZE;
5619 
5620 	if (rt6) {
5621 		rt6_dst = &rt6->rt6i_dst;
5622 		rt6_src = &rt6->rt6i_src;
5623 		rt6_flags = rt6->rt6i_flags;
5624 	} else {
5625 		rt6_dst = &rt->fib6_dst;
5626 		rt6_src = &rt->fib6_src;
5627 		rt6_flags = rt->fib6_flags;
5628 	}
5629 
5630 	rtm = nlmsg_data(nlh);
5631 	rtm->rtm_family = AF_INET6;
5632 	rtm->rtm_dst_len = rt6_dst->plen;
5633 	rtm->rtm_src_len = rt6_src->plen;
5634 	rtm->rtm_tos = 0;
5635 	if (rt->fib6_table)
5636 		table = rt->fib6_table->tb6_id;
5637 	else
5638 		table = RT6_TABLE_UNSPEC;
5639 	rtm->rtm_table = table < 256 ? table : RT_TABLE_COMPAT;
5640 	if (nla_put_u32(skb, RTA_TABLE, table))
5641 		goto nla_put_failure;
5642 
5643 	rtm->rtm_type = rt->fib6_type;
5644 	rtm->rtm_flags = 0;
5645 	rtm->rtm_scope = RT_SCOPE_UNIVERSE;
5646 	rtm->rtm_protocol = rt->fib6_protocol;
5647 
5648 	if (rt6_flags & RTF_CACHE)
5649 		rtm->rtm_flags |= RTM_F_CLONED;
5650 
5651 	if (dest) {
5652 		if (nla_put_in6_addr(skb, RTA_DST, dest))
5653 			goto nla_put_failure;
5654 		rtm->rtm_dst_len = 128;
5655 	} else if (rtm->rtm_dst_len)
5656 		if (nla_put_in6_addr(skb, RTA_DST, &rt6_dst->addr))
5657 			goto nla_put_failure;
5658 #ifdef CONFIG_IPV6_SUBTREES
5659 	if (src) {
5660 		if (nla_put_in6_addr(skb, RTA_SRC, src))
5661 			goto nla_put_failure;
5662 		rtm->rtm_src_len = 128;
5663 	} else if (rtm->rtm_src_len &&
5664 		   nla_put_in6_addr(skb, RTA_SRC, &rt6_src->addr))
5665 		goto nla_put_failure;
5666 #endif
5667 	if (iif) {
5668 #ifdef CONFIG_IPV6_MROUTE
5669 		if (ipv6_addr_is_multicast(&rt6_dst->addr)) {
5670 			int err = ip6mr_get_route(net, skb, rtm, portid);
5671 
5672 			if (err == 0)
5673 				return 0;
5674 			if (err < 0)
5675 				goto nla_put_failure;
5676 		} else
5677 #endif
5678 			if (nla_put_u32(skb, RTA_IIF, iif))
5679 				goto nla_put_failure;
5680 	} else if (dest) {
5681 		struct in6_addr saddr_buf;
5682 		if (ip6_route_get_saddr(net, rt, dest, 0, &saddr_buf) == 0 &&
5683 		    nla_put_in6_addr(skb, RTA_PREFSRC, &saddr_buf))
5684 			goto nla_put_failure;
5685 	}
5686 
5687 	if (rt->fib6_prefsrc.plen) {
5688 		struct in6_addr saddr_buf;
5689 		saddr_buf = rt->fib6_prefsrc.addr;
5690 		if (nla_put_in6_addr(skb, RTA_PREFSRC, &saddr_buf))
5691 			goto nla_put_failure;
5692 	}
5693 
5694 	pmetrics = dst ? dst_metrics_ptr(dst) : rt->fib6_metrics->metrics;
5695 	if (rtnetlink_put_metrics(skb, pmetrics) < 0)
5696 		goto nla_put_failure;
5697 
5698 	if (nla_put_u32(skb, RTA_PRIORITY, rt->fib6_metric))
5699 		goto nla_put_failure;
5700 
5701 	/* For multipath routes, walk the siblings list and add
5702 	 * each as a nexthop within RTA_MULTIPATH.
5703 	 */
5704 	if (rt6) {
5705 		if (rt6_flags & RTF_GATEWAY &&
5706 		    nla_put_in6_addr(skb, RTA_GATEWAY, &rt6->rt6i_gateway))
5707 			goto nla_put_failure;
5708 
5709 		if (dst->dev && nla_put_u32(skb, RTA_OIF, dst->dev->ifindex))
5710 			goto nla_put_failure;
5711 
5712 		if (dst->lwtstate &&
5713 		    lwtunnel_fill_encap(skb, dst->lwtstate, RTA_ENCAP, RTA_ENCAP_TYPE) < 0)
5714 			goto nla_put_failure;
5715 	} else if (rt->fib6_nsiblings) {
5716 		struct fib6_info *sibling, *next_sibling;
5717 		struct nlattr *mp;
5718 
5719 		mp = nla_nest_start_noflag(skb, RTA_MULTIPATH);
5720 		if (!mp)
5721 			goto nla_put_failure;
5722 
5723 		if (fib_add_nexthop(skb, &rt->fib6_nh->nh_common,
5724 				    rt->fib6_nh->fib_nh_weight, AF_INET6,
5725 				    0) < 0)
5726 			goto nla_put_failure;
5727 
5728 		list_for_each_entry_safe(sibling, next_sibling,
5729 					 &rt->fib6_siblings, fib6_siblings) {
5730 			if (fib_add_nexthop(skb, &sibling->fib6_nh->nh_common,
5731 					    sibling->fib6_nh->fib_nh_weight,
5732 					    AF_INET6, 0) < 0)
5733 				goto nla_put_failure;
5734 		}
5735 
5736 		nla_nest_end(skb, mp);
5737 	} else if (rt->nh) {
5738 		if (nla_put_u32(skb, RTA_NH_ID, rt->nh->id))
5739 			goto nla_put_failure;
5740 
5741 		if (nexthop_is_blackhole(rt->nh))
5742 			rtm->rtm_type = RTN_BLACKHOLE;
5743 
5744 		if (READ_ONCE(net->ipv4.sysctl_nexthop_compat_mode) &&
5745 		    rt6_fill_node_nexthop(skb, rt->nh, &nh_flags) < 0)
5746 			goto nla_put_failure;
5747 
5748 		rtm->rtm_flags |= nh_flags;
5749 	} else {
5750 		if (fib_nexthop_info(skb, &rt->fib6_nh->nh_common, AF_INET6,
5751 				     &nh_flags, false) < 0)
5752 			goto nla_put_failure;
5753 
5754 		rtm->rtm_flags |= nh_flags;
5755 	}
5756 
5757 	if (rt6_flags & RTF_EXPIRES) {
5758 		expires = dst ? dst->expires : rt->expires;
5759 		expires -= jiffies;
5760 	}
5761 
5762 	if (!dst) {
5763 		if (READ_ONCE(rt->offload))
5764 			rtm->rtm_flags |= RTM_F_OFFLOAD;
5765 		if (READ_ONCE(rt->trap))
5766 			rtm->rtm_flags |= RTM_F_TRAP;
5767 		if (READ_ONCE(rt->offload_failed))
5768 			rtm->rtm_flags |= RTM_F_OFFLOAD_FAILED;
5769 	}
5770 
5771 	if (rtnl_put_cacheinfo(skb, dst, 0, expires, dst ? dst->error : 0) < 0)
5772 		goto nla_put_failure;
5773 
5774 	if (nla_put_u8(skb, RTA_PREF, IPV6_EXTRACT_PREF(rt6_flags)))
5775 		goto nla_put_failure;
5776 
5777 
5778 	nlmsg_end(skb, nlh);
5779 	return 0;
5780 
5781 nla_put_failure:
5782 	nlmsg_cancel(skb, nlh);
5783 	return -EMSGSIZE;
5784 }
5785 
fib6_info_nh_uses_dev(struct fib6_nh * nh,void * arg)5786 static int fib6_info_nh_uses_dev(struct fib6_nh *nh, void *arg)
5787 {
5788 	const struct net_device *dev = arg;
5789 
5790 	if (nh->fib_nh_dev == dev)
5791 		return 1;
5792 
5793 	return 0;
5794 }
5795 
fib6_info_uses_dev(const struct fib6_info * f6i,const struct net_device * dev)5796 static bool fib6_info_uses_dev(const struct fib6_info *f6i,
5797 			       const struct net_device *dev)
5798 {
5799 	if (f6i->nh) {
5800 		struct net_device *_dev = (struct net_device *)dev;
5801 
5802 		return !!nexthop_for_each_fib6_nh(f6i->nh,
5803 						  fib6_info_nh_uses_dev,
5804 						  _dev);
5805 	}
5806 
5807 	if (f6i->fib6_nh->fib_nh_dev == dev)
5808 		return true;
5809 
5810 	if (f6i->fib6_nsiblings) {
5811 		struct fib6_info *sibling, *next_sibling;
5812 
5813 		list_for_each_entry_safe(sibling, next_sibling,
5814 					 &f6i->fib6_siblings, fib6_siblings) {
5815 			if (sibling->fib6_nh->fib_nh_dev == dev)
5816 				return true;
5817 		}
5818 	}
5819 
5820 	return false;
5821 }
5822 
5823 struct fib6_nh_exception_dump_walker {
5824 	struct rt6_rtnl_dump_arg *dump;
5825 	struct fib6_info *rt;
5826 	unsigned int flags;
5827 	unsigned int skip;
5828 	unsigned int count;
5829 };
5830 
rt6_nh_dump_exceptions(struct fib6_nh * nh,void * arg)5831 static int rt6_nh_dump_exceptions(struct fib6_nh *nh, void *arg)
5832 {
5833 	struct fib6_nh_exception_dump_walker *w = arg;
5834 	struct rt6_rtnl_dump_arg *dump = w->dump;
5835 	struct rt6_exception_bucket *bucket;
5836 	struct rt6_exception *rt6_ex;
5837 	int i, err;
5838 
5839 	bucket = fib6_nh_get_excptn_bucket(nh, NULL);
5840 	if (!bucket)
5841 		return 0;
5842 
5843 	for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
5844 		hlist_for_each_entry(rt6_ex, &bucket->chain, hlist) {
5845 			if (w->skip) {
5846 				w->skip--;
5847 				continue;
5848 			}
5849 
5850 			/* Expiration of entries doesn't bump sernum, insertion
5851 			 * does. Removal is triggered by insertion, so we can
5852 			 * rely on the fact that if entries change between two
5853 			 * partial dumps, this node is scanned again completely,
5854 			 * see rt6_insert_exception() and fib6_dump_table().
5855 			 *
5856 			 * Count expired entries we go through as handled
5857 			 * entries that we'll skip next time, in case of partial
5858 			 * node dump. Otherwise, if entries expire meanwhile,
5859 			 * we'll skip the wrong amount.
5860 			 */
5861 			if (rt6_check_expired(rt6_ex->rt6i)) {
5862 				w->count++;
5863 				continue;
5864 			}
5865 
5866 			err = rt6_fill_node(dump->net, dump->skb, w->rt,
5867 					    &rt6_ex->rt6i->dst, NULL, NULL, 0,
5868 					    RTM_NEWROUTE,
5869 					    NETLINK_CB(dump->cb->skb).portid,
5870 					    dump->cb->nlh->nlmsg_seq, w->flags);
5871 			if (err)
5872 				return err;
5873 
5874 			w->count++;
5875 		}
5876 		bucket++;
5877 	}
5878 
5879 	return 0;
5880 }
5881 
5882 /* 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)5883 int rt6_dump_route(struct fib6_info *rt, void *p_arg, unsigned int skip)
5884 {
5885 	struct rt6_rtnl_dump_arg *arg = (struct rt6_rtnl_dump_arg *) p_arg;
5886 	struct fib_dump_filter *filter = &arg->filter;
5887 	unsigned int flags = NLM_F_MULTI;
5888 	struct net *net = arg->net;
5889 	int count = 0;
5890 
5891 	if (rt == net->ipv6.fib6_null_entry)
5892 		return -1;
5893 
5894 	if ((filter->flags & RTM_F_PREFIX) &&
5895 	    !(rt->fib6_flags & RTF_PREFIX_RT)) {
5896 		/* success since this is not a prefix route */
5897 		return -1;
5898 	}
5899 	if (filter->filter_set &&
5900 	    ((filter->rt_type  && rt->fib6_type != filter->rt_type) ||
5901 	     (filter->dev      && !fib6_info_uses_dev(rt, filter->dev)) ||
5902 	     (filter->protocol && rt->fib6_protocol != filter->protocol))) {
5903 		return -1;
5904 	}
5905 
5906 	if (filter->filter_set ||
5907 	    !filter->dump_routes || !filter->dump_exceptions) {
5908 		flags |= NLM_F_DUMP_FILTERED;
5909 	}
5910 
5911 	if (filter->dump_routes) {
5912 		if (skip) {
5913 			skip--;
5914 		} else {
5915 			if (rt6_fill_node(net, arg->skb, rt, NULL, NULL, NULL,
5916 					  0, RTM_NEWROUTE,
5917 					  NETLINK_CB(arg->cb->skb).portid,
5918 					  arg->cb->nlh->nlmsg_seq, flags)) {
5919 				return 0;
5920 			}
5921 			count++;
5922 		}
5923 	}
5924 
5925 	if (filter->dump_exceptions) {
5926 		struct fib6_nh_exception_dump_walker w = { .dump = arg,
5927 							   .rt = rt,
5928 							   .flags = flags,
5929 							   .skip = skip,
5930 							   .count = 0 };
5931 		int err;
5932 
5933 		rcu_read_lock();
5934 		if (rt->nh) {
5935 			err = nexthop_for_each_fib6_nh(rt->nh,
5936 						       rt6_nh_dump_exceptions,
5937 						       &w);
5938 		} else {
5939 			err = rt6_nh_dump_exceptions(rt->fib6_nh, &w);
5940 		}
5941 		rcu_read_unlock();
5942 
5943 		if (err)
5944 			return count += w.count;
5945 	}
5946 
5947 	return -1;
5948 }
5949 
inet6_rtm_valid_getroute_req(struct sk_buff * skb,const struct nlmsghdr * nlh,struct nlattr ** tb,struct netlink_ext_ack * extack)5950 static int inet6_rtm_valid_getroute_req(struct sk_buff *skb,
5951 					const struct nlmsghdr *nlh,
5952 					struct nlattr **tb,
5953 					struct netlink_ext_ack *extack)
5954 {
5955 	struct rtmsg *rtm;
5956 	int i, err;
5957 
5958 	if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) {
5959 		NL_SET_ERR_MSG_MOD(extack,
5960 				   "Invalid header for get route request");
5961 		return -EINVAL;
5962 	}
5963 
5964 	if (!netlink_strict_get_check(skb))
5965 		return nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX,
5966 					      rtm_ipv6_policy, extack);
5967 
5968 	rtm = nlmsg_data(nlh);
5969 	if ((rtm->rtm_src_len && rtm->rtm_src_len != 128) ||
5970 	    (rtm->rtm_dst_len && rtm->rtm_dst_len != 128) ||
5971 	    rtm->rtm_table || rtm->rtm_protocol || rtm->rtm_scope ||
5972 	    rtm->rtm_type) {
5973 		NL_SET_ERR_MSG_MOD(extack, "Invalid values in header for get route request");
5974 		return -EINVAL;
5975 	}
5976 	if (rtm->rtm_flags & ~RTM_F_FIB_MATCH) {
5977 		NL_SET_ERR_MSG_MOD(extack,
5978 				   "Invalid flags for get route request");
5979 		return -EINVAL;
5980 	}
5981 
5982 	err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX,
5983 					    rtm_ipv6_policy, extack);
5984 	if (err)
5985 		return err;
5986 
5987 	if ((tb[RTA_SRC] && !rtm->rtm_src_len) ||
5988 	    (tb[RTA_DST] && !rtm->rtm_dst_len)) {
5989 		NL_SET_ERR_MSG_MOD(extack, "rtm_src_len and rtm_dst_len must be 128 for IPv6");
5990 		return -EINVAL;
5991 	}
5992 
5993 	for (i = 0; i <= RTA_MAX; i++) {
5994 		if (!tb[i])
5995 			continue;
5996 
5997 		switch (i) {
5998 		case RTA_SRC:
5999 		case RTA_DST:
6000 		case RTA_IIF:
6001 		case RTA_OIF:
6002 		case RTA_MARK:
6003 		case RTA_UID:
6004 		case RTA_SPORT:
6005 		case RTA_DPORT:
6006 		case RTA_IP_PROTO:
6007 			break;
6008 		default:
6009 			NL_SET_ERR_MSG_MOD(extack, "Unsupported attribute in get route request");
6010 			return -EINVAL;
6011 		}
6012 	}
6013 
6014 	return 0;
6015 }
6016 
inet6_rtm_getroute(struct sk_buff * in_skb,struct nlmsghdr * nlh,struct netlink_ext_ack * extack)6017 static int inet6_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
6018 			      struct netlink_ext_ack *extack)
6019 {
6020 	struct net *net = sock_net(in_skb->sk);
6021 	struct nlattr *tb[RTA_MAX+1];
6022 	int err, iif = 0, oif = 0;
6023 	struct fib6_info *from;
6024 	struct dst_entry *dst;
6025 	struct rt6_info *rt;
6026 	struct sk_buff *skb;
6027 	struct rtmsg *rtm;
6028 	struct flowi6 fl6 = {};
6029 	bool fibmatch;
6030 
6031 	err = inet6_rtm_valid_getroute_req(in_skb, nlh, tb, extack);
6032 	if (err < 0)
6033 		goto errout;
6034 
6035 	err = -EINVAL;
6036 	rtm = nlmsg_data(nlh);
6037 	fl6.flowlabel = ip6_make_flowinfo(rtm->rtm_tos, 0);
6038 	fibmatch = !!(rtm->rtm_flags & RTM_F_FIB_MATCH);
6039 
6040 	if (tb[RTA_SRC]) {
6041 		if (nla_len(tb[RTA_SRC]) < sizeof(struct in6_addr))
6042 			goto errout;
6043 
6044 		fl6.saddr = *(struct in6_addr *)nla_data(tb[RTA_SRC]);
6045 	}
6046 
6047 	if (tb[RTA_DST]) {
6048 		if (nla_len(tb[RTA_DST]) < sizeof(struct in6_addr))
6049 			goto errout;
6050 
6051 		fl6.daddr = *(struct in6_addr *)nla_data(tb[RTA_DST]);
6052 	}
6053 
6054 	if (tb[RTA_IIF])
6055 		iif = nla_get_u32(tb[RTA_IIF]);
6056 
6057 	if (tb[RTA_OIF])
6058 		oif = nla_get_u32(tb[RTA_OIF]);
6059 
6060 	if (tb[RTA_MARK])
6061 		fl6.flowi6_mark = nla_get_u32(tb[RTA_MARK]);
6062 
6063 	if (tb[RTA_UID])
6064 		fl6.flowi6_uid = make_kuid(current_user_ns(),
6065 					   nla_get_u32(tb[RTA_UID]));
6066 	else
6067 		fl6.flowi6_uid = iif ? INVALID_UID : current_uid();
6068 
6069 	if (tb[RTA_SPORT])
6070 		fl6.fl6_sport = nla_get_be16(tb[RTA_SPORT]);
6071 
6072 	if (tb[RTA_DPORT])
6073 		fl6.fl6_dport = nla_get_be16(tb[RTA_DPORT]);
6074 
6075 	if (tb[RTA_IP_PROTO]) {
6076 		err = rtm_getroute_parse_ip_proto(tb[RTA_IP_PROTO],
6077 						  &fl6.flowi6_proto, AF_INET6,
6078 						  extack);
6079 		if (err)
6080 			goto errout;
6081 	}
6082 
6083 	if (iif) {
6084 		struct net_device *dev;
6085 		int flags = 0;
6086 
6087 		rcu_read_lock();
6088 
6089 		dev = dev_get_by_index_rcu(net, iif);
6090 		if (!dev) {
6091 			rcu_read_unlock();
6092 			err = -ENODEV;
6093 			goto errout;
6094 		}
6095 
6096 		fl6.flowi6_iif = iif;
6097 
6098 		if (!ipv6_addr_any(&fl6.saddr))
6099 			flags |= RT6_LOOKUP_F_HAS_SADDR;
6100 
6101 		dst = ip6_route_input_lookup(net, dev, &fl6, NULL, flags);
6102 
6103 		rcu_read_unlock();
6104 	} else {
6105 		fl6.flowi6_oif = oif;
6106 
6107 		dst = ip6_route_output(net, NULL, &fl6);
6108 	}
6109 
6110 
6111 	rt = container_of(dst, struct rt6_info, dst);
6112 	if (rt->dst.error) {
6113 		err = rt->dst.error;
6114 		ip6_rt_put(rt);
6115 		goto errout;
6116 	}
6117 
6118 	if (rt == net->ipv6.ip6_null_entry) {
6119 		err = rt->dst.error;
6120 		ip6_rt_put(rt);
6121 		goto errout;
6122 	}
6123 
6124 	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
6125 	if (!skb) {
6126 		ip6_rt_put(rt);
6127 		err = -ENOBUFS;
6128 		goto errout;
6129 	}
6130 
6131 	skb_dst_set(skb, &rt->dst);
6132 
6133 	rcu_read_lock();
6134 	from = rcu_dereference(rt->from);
6135 	if (from) {
6136 		if (fibmatch)
6137 			err = rt6_fill_node(net, skb, from, NULL, NULL, NULL,
6138 					    iif, RTM_NEWROUTE,
6139 					    NETLINK_CB(in_skb).portid,
6140 					    nlh->nlmsg_seq, 0);
6141 		else
6142 			err = rt6_fill_node(net, skb, from, dst, &fl6.daddr,
6143 					    &fl6.saddr, iif, RTM_NEWROUTE,
6144 					    NETLINK_CB(in_skb).portid,
6145 					    nlh->nlmsg_seq, 0);
6146 	} else {
6147 		err = -ENETUNREACH;
6148 	}
6149 	rcu_read_unlock();
6150 
6151 	if (err < 0) {
6152 		kfree_skb(skb);
6153 		goto errout;
6154 	}
6155 
6156 	err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
6157 errout:
6158 	return err;
6159 }
6160 
inet6_rt_notify(int event,struct fib6_info * rt,struct nl_info * info,unsigned int nlm_flags)6161 void inet6_rt_notify(int event, struct fib6_info *rt, struct nl_info *info,
6162 		     unsigned int nlm_flags)
6163 {
6164 	struct sk_buff *skb;
6165 	struct net *net = info->nl_net;
6166 	u32 seq;
6167 	int err;
6168 
6169 	err = -ENOBUFS;
6170 	seq = info->nlh ? info->nlh->nlmsg_seq : 0;
6171 
6172 	skb = nlmsg_new(rt6_nlmsg_size(rt), gfp_any());
6173 	if (!skb)
6174 		goto errout;
6175 
6176 	err = rt6_fill_node(net, skb, rt, NULL, NULL, NULL, 0,
6177 			    event, info->portid, seq, nlm_flags);
6178 	if (err < 0) {
6179 		/* -EMSGSIZE implies BUG in rt6_nlmsg_size() */
6180 		WARN_ON(err == -EMSGSIZE);
6181 		kfree_skb(skb);
6182 		goto errout;
6183 	}
6184 	rtnl_notify(skb, net, info->portid, RTNLGRP_IPV6_ROUTE,
6185 		    info->nlh, gfp_any());
6186 	return;
6187 errout:
6188 	if (err < 0)
6189 		rtnl_set_sk_err(net, RTNLGRP_IPV6_ROUTE, err);
6190 }
6191 
fib6_rt_update(struct net * net,struct fib6_info * rt,struct nl_info * info)6192 void fib6_rt_update(struct net *net, struct fib6_info *rt,
6193 		    struct nl_info *info)
6194 {
6195 	u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0;
6196 	struct sk_buff *skb;
6197 	int err = -ENOBUFS;
6198 
6199 	skb = nlmsg_new(rt6_nlmsg_size(rt), gfp_any());
6200 	if (!skb)
6201 		goto errout;
6202 
6203 	err = rt6_fill_node(net, skb, rt, NULL, NULL, NULL, 0,
6204 			    RTM_NEWROUTE, info->portid, seq, NLM_F_REPLACE);
6205 	if (err < 0) {
6206 		/* -EMSGSIZE implies BUG in rt6_nlmsg_size() */
6207 		WARN_ON(err == -EMSGSIZE);
6208 		kfree_skb(skb);
6209 		goto errout;
6210 	}
6211 	rtnl_notify(skb, net, info->portid, RTNLGRP_IPV6_ROUTE,
6212 		    info->nlh, gfp_any());
6213 	return;
6214 errout:
6215 	if (err < 0)
6216 		rtnl_set_sk_err(net, RTNLGRP_IPV6_ROUTE, err);
6217 }
6218 
fib6_info_hw_flags_set(struct net * net,struct fib6_info * f6i,bool offload,bool trap,bool offload_failed)6219 void fib6_info_hw_flags_set(struct net *net, struct fib6_info *f6i,
6220 			    bool offload, bool trap, bool offload_failed)
6221 {
6222 	struct sk_buff *skb;
6223 	int err;
6224 
6225 	if (READ_ONCE(f6i->offload) == offload &&
6226 	    READ_ONCE(f6i->trap) == trap &&
6227 	    READ_ONCE(f6i->offload_failed) == offload_failed)
6228 		return;
6229 
6230 	WRITE_ONCE(f6i->offload, offload);
6231 	WRITE_ONCE(f6i->trap, trap);
6232 
6233 	/* 2 means send notifications only if offload_failed was changed. */
6234 	if (net->ipv6.sysctl.fib_notify_on_flag_change == 2 &&
6235 	    READ_ONCE(f6i->offload_failed) == offload_failed)
6236 		return;
6237 
6238 	WRITE_ONCE(f6i->offload_failed, offload_failed);
6239 
6240 	if (!rcu_access_pointer(f6i->fib6_node))
6241 		/* The route was removed from the tree, do not send
6242 		 * notification.
6243 		 */
6244 		return;
6245 
6246 	if (!net->ipv6.sysctl.fib_notify_on_flag_change)
6247 		return;
6248 
6249 	skb = nlmsg_new(rt6_nlmsg_size(f6i), GFP_KERNEL);
6250 	if (!skb) {
6251 		err = -ENOBUFS;
6252 		goto errout;
6253 	}
6254 
6255 	err = rt6_fill_node(net, skb, f6i, NULL, NULL, NULL, 0, RTM_NEWROUTE, 0,
6256 			    0, 0);
6257 	if (err < 0) {
6258 		/* -EMSGSIZE implies BUG in rt6_nlmsg_size() */
6259 		WARN_ON(err == -EMSGSIZE);
6260 		kfree_skb(skb);
6261 		goto errout;
6262 	}
6263 
6264 	rtnl_notify(skb, net, 0, RTNLGRP_IPV6_ROUTE, NULL, GFP_KERNEL);
6265 	return;
6266 
6267 errout:
6268 	rtnl_set_sk_err(net, RTNLGRP_IPV6_ROUTE, err);
6269 }
6270 EXPORT_SYMBOL(fib6_info_hw_flags_set);
6271 
ip6_route_dev_notify(struct notifier_block * this,unsigned long event,void * ptr)6272 static int ip6_route_dev_notify(struct notifier_block *this,
6273 				unsigned long event, void *ptr)
6274 {
6275 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
6276 	struct net *net = dev_net(dev);
6277 
6278 	if (!(dev->flags & IFF_LOOPBACK))
6279 		return NOTIFY_OK;
6280 
6281 	if (event == NETDEV_REGISTER) {
6282 		net->ipv6.fib6_null_entry->fib6_nh->fib_nh_dev = dev;
6283 		net->ipv6.ip6_null_entry->dst.dev = dev;
6284 		net->ipv6.ip6_null_entry->rt6i_idev = in6_dev_get(dev);
6285 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
6286 		net->ipv6.ip6_prohibit_entry->dst.dev = dev;
6287 		net->ipv6.ip6_prohibit_entry->rt6i_idev = in6_dev_get(dev);
6288 		net->ipv6.ip6_blk_hole_entry->dst.dev = dev;
6289 		net->ipv6.ip6_blk_hole_entry->rt6i_idev = in6_dev_get(dev);
6290 #endif
6291 	 } else if (event == NETDEV_UNREGISTER &&
6292 		    dev->reg_state != NETREG_UNREGISTERED) {
6293 		/* NETDEV_UNREGISTER could be fired for multiple times by
6294 		 * netdev_wait_allrefs(). Make sure we only call this once.
6295 		 */
6296 		in6_dev_put_clear(&net->ipv6.ip6_null_entry->rt6i_idev);
6297 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
6298 		in6_dev_put_clear(&net->ipv6.ip6_prohibit_entry->rt6i_idev);
6299 		in6_dev_put_clear(&net->ipv6.ip6_blk_hole_entry->rt6i_idev);
6300 #endif
6301 	}
6302 
6303 	return NOTIFY_OK;
6304 }
6305 
6306 /*
6307  *	/proc
6308  */
6309 
6310 #ifdef CONFIG_PROC_FS
rt6_stats_seq_show(struct seq_file * seq,void * v)6311 static int rt6_stats_seq_show(struct seq_file *seq, void *v)
6312 {
6313 	struct net *net = (struct net *)seq->private;
6314 	seq_printf(seq, "%04x %04x %04x %04x %04x %04x %04x\n",
6315 		   net->ipv6.rt6_stats->fib_nodes,
6316 		   net->ipv6.rt6_stats->fib_route_nodes,
6317 		   atomic_read(&net->ipv6.rt6_stats->fib_rt_alloc),
6318 		   net->ipv6.rt6_stats->fib_rt_entries,
6319 		   net->ipv6.rt6_stats->fib_rt_cache,
6320 		   dst_entries_get_slow(&net->ipv6.ip6_dst_ops),
6321 		   net->ipv6.rt6_stats->fib_discarded_routes);
6322 
6323 	return 0;
6324 }
6325 #endif	/* CONFIG_PROC_FS */
6326 
6327 #ifdef CONFIG_SYSCTL
6328 
ipv6_sysctl_rtcache_flush(struct ctl_table * ctl,int write,void * buffer,size_t * lenp,loff_t * ppos)6329 static int ipv6_sysctl_rtcache_flush(struct ctl_table *ctl, int write,
6330 			      void *buffer, size_t *lenp, loff_t *ppos)
6331 {
6332 	struct net *net;
6333 	int delay;
6334 	int ret;
6335 	if (!write)
6336 		return -EINVAL;
6337 
6338 	net = (struct net *)ctl->extra1;
6339 	delay = net->ipv6.sysctl.flush_delay;
6340 	ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
6341 	if (ret)
6342 		return ret;
6343 
6344 	fib6_run_gc(delay <= 0 ? 0 : (unsigned long)delay, net, delay > 0);
6345 	return 0;
6346 }
6347 
6348 static struct ctl_table ipv6_route_table_template[] = {
6349 	{
6350 		.procname	=	"max_size",
6351 		.data		=	&init_net.ipv6.sysctl.ip6_rt_max_size,
6352 		.maxlen		=	sizeof(int),
6353 		.mode		=	0644,
6354 		.proc_handler	=	proc_dointvec,
6355 	},
6356 	{
6357 		.procname	=	"gc_thresh",
6358 		.data		=	&ip6_dst_ops_template.gc_thresh,
6359 		.maxlen		=	sizeof(int),
6360 		.mode		=	0644,
6361 		.proc_handler	=	proc_dointvec,
6362 	},
6363 	{
6364 		.procname	=	"flush",
6365 		.data		=	&init_net.ipv6.sysctl.flush_delay,
6366 		.maxlen		=	sizeof(int),
6367 		.mode		=	0200,
6368 		.proc_handler	=	ipv6_sysctl_rtcache_flush
6369 	},
6370 	{
6371 		.procname	=	"gc_min_interval",
6372 		.data		=	&init_net.ipv6.sysctl.ip6_rt_gc_min_interval,
6373 		.maxlen		=	sizeof(int),
6374 		.mode		=	0644,
6375 		.proc_handler	=	proc_dointvec_jiffies,
6376 	},
6377 	{
6378 		.procname	=	"gc_timeout",
6379 		.data		=	&init_net.ipv6.sysctl.ip6_rt_gc_timeout,
6380 		.maxlen		=	sizeof(int),
6381 		.mode		=	0644,
6382 		.proc_handler	=	proc_dointvec_jiffies,
6383 	},
6384 	{
6385 		.procname	=	"gc_interval",
6386 		.data		=	&init_net.ipv6.sysctl.ip6_rt_gc_interval,
6387 		.maxlen		=	sizeof(int),
6388 		.mode		=	0644,
6389 		.proc_handler	=	proc_dointvec_jiffies,
6390 	},
6391 	{
6392 		.procname	=	"gc_elasticity",
6393 		.data		=	&init_net.ipv6.sysctl.ip6_rt_gc_elasticity,
6394 		.maxlen		=	sizeof(int),
6395 		.mode		=	0644,
6396 		.proc_handler	=	proc_dointvec,
6397 	},
6398 	{
6399 		.procname	=	"mtu_expires",
6400 		.data		=	&init_net.ipv6.sysctl.ip6_rt_mtu_expires,
6401 		.maxlen		=	sizeof(int),
6402 		.mode		=	0644,
6403 		.proc_handler	=	proc_dointvec_jiffies,
6404 	},
6405 	{
6406 		.procname	=	"min_adv_mss",
6407 		.data		=	&init_net.ipv6.sysctl.ip6_rt_min_advmss,
6408 		.maxlen		=	sizeof(int),
6409 		.mode		=	0644,
6410 		.proc_handler	=	proc_dointvec,
6411 	},
6412 	{
6413 		.procname	=	"gc_min_interval_ms",
6414 		.data		=	&init_net.ipv6.sysctl.ip6_rt_gc_min_interval,
6415 		.maxlen		=	sizeof(int),
6416 		.mode		=	0644,
6417 		.proc_handler	=	proc_dointvec_ms_jiffies,
6418 	},
6419 	{
6420 		.procname	=	"skip_notify_on_dev_down",
6421 		.data		=	&init_net.ipv6.sysctl.skip_notify_on_dev_down,
6422 		.maxlen		=	sizeof(int),
6423 		.mode		=	0644,
6424 		.proc_handler	=	proc_dointvec_minmax,
6425 		.extra1		=	SYSCTL_ZERO,
6426 		.extra2		=	SYSCTL_ONE,
6427 	},
6428 	{ }
6429 };
6430 
ipv6_route_sysctl_init(struct net * net)6431 struct ctl_table * __net_init ipv6_route_sysctl_init(struct net *net)
6432 {
6433 	struct ctl_table *table;
6434 
6435 	table = kmemdup(ipv6_route_table_template,
6436 			sizeof(ipv6_route_table_template),
6437 			GFP_KERNEL);
6438 
6439 	if (table) {
6440 		table[0].data = &net->ipv6.sysctl.ip6_rt_max_size;
6441 		table[1].data = &net->ipv6.ip6_dst_ops.gc_thresh;
6442 		table[2].data = &net->ipv6.sysctl.flush_delay;
6443 		table[2].extra1 = net;
6444 		table[3].data = &net->ipv6.sysctl.ip6_rt_gc_min_interval;
6445 		table[4].data = &net->ipv6.sysctl.ip6_rt_gc_timeout;
6446 		table[5].data = &net->ipv6.sysctl.ip6_rt_gc_interval;
6447 		table[6].data = &net->ipv6.sysctl.ip6_rt_gc_elasticity;
6448 		table[7].data = &net->ipv6.sysctl.ip6_rt_mtu_expires;
6449 		table[8].data = &net->ipv6.sysctl.ip6_rt_min_advmss;
6450 		table[9].data = &net->ipv6.sysctl.ip6_rt_gc_min_interval;
6451 		table[10].data = &net->ipv6.sysctl.skip_notify_on_dev_down;
6452 
6453 		/* Don't export sysctls to unprivileged users */
6454 		if (net->user_ns != &init_user_ns)
6455 			table[1].procname = NULL;
6456 	}
6457 
6458 	return table;
6459 }
6460 #endif
6461 
ip6_route_net_init(struct net * net)6462 static int __net_init ip6_route_net_init(struct net *net)
6463 {
6464 	int ret = -ENOMEM;
6465 
6466 	memcpy(&net->ipv6.ip6_dst_ops, &ip6_dst_ops_template,
6467 	       sizeof(net->ipv6.ip6_dst_ops));
6468 
6469 	if (dst_entries_init(&net->ipv6.ip6_dst_ops) < 0)
6470 		goto out_ip6_dst_ops;
6471 
6472 	net->ipv6.fib6_null_entry = fib6_info_alloc(GFP_KERNEL, true);
6473 	if (!net->ipv6.fib6_null_entry)
6474 		goto out_ip6_dst_entries;
6475 	memcpy(net->ipv6.fib6_null_entry, &fib6_null_entry_template,
6476 	       sizeof(*net->ipv6.fib6_null_entry));
6477 
6478 	net->ipv6.ip6_null_entry = kmemdup(&ip6_null_entry_template,
6479 					   sizeof(*net->ipv6.ip6_null_entry),
6480 					   GFP_KERNEL);
6481 	if (!net->ipv6.ip6_null_entry)
6482 		goto out_fib6_null_entry;
6483 	net->ipv6.ip6_null_entry->dst.ops = &net->ipv6.ip6_dst_ops;
6484 	dst_init_metrics(&net->ipv6.ip6_null_entry->dst,
6485 			 ip6_template_metrics, true);
6486 	INIT_LIST_HEAD(&net->ipv6.ip6_null_entry->rt6i_uncached);
6487 
6488 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
6489 	net->ipv6.fib6_has_custom_rules = false;
6490 	net->ipv6.ip6_prohibit_entry = kmemdup(&ip6_prohibit_entry_template,
6491 					       sizeof(*net->ipv6.ip6_prohibit_entry),
6492 					       GFP_KERNEL);
6493 	if (!net->ipv6.ip6_prohibit_entry)
6494 		goto out_ip6_null_entry;
6495 	net->ipv6.ip6_prohibit_entry->dst.ops = &net->ipv6.ip6_dst_ops;
6496 	dst_init_metrics(&net->ipv6.ip6_prohibit_entry->dst,
6497 			 ip6_template_metrics, true);
6498 	INIT_LIST_HEAD(&net->ipv6.ip6_prohibit_entry->rt6i_uncached);
6499 
6500 	net->ipv6.ip6_blk_hole_entry = kmemdup(&ip6_blk_hole_entry_template,
6501 					       sizeof(*net->ipv6.ip6_blk_hole_entry),
6502 					       GFP_KERNEL);
6503 	if (!net->ipv6.ip6_blk_hole_entry)
6504 		goto out_ip6_prohibit_entry;
6505 	net->ipv6.ip6_blk_hole_entry->dst.ops = &net->ipv6.ip6_dst_ops;
6506 	dst_init_metrics(&net->ipv6.ip6_blk_hole_entry->dst,
6507 			 ip6_template_metrics, true);
6508 	INIT_LIST_HEAD(&net->ipv6.ip6_blk_hole_entry->rt6i_uncached);
6509 #ifdef CONFIG_IPV6_SUBTREES
6510 	net->ipv6.fib6_routes_require_src = 0;
6511 #endif
6512 #endif
6513 
6514 	net->ipv6.sysctl.flush_delay = 0;
6515 	net->ipv6.sysctl.ip6_rt_max_size = 4096;
6516 	net->ipv6.sysctl.ip6_rt_gc_min_interval = HZ / 2;
6517 	net->ipv6.sysctl.ip6_rt_gc_timeout = 60*HZ;
6518 	net->ipv6.sysctl.ip6_rt_gc_interval = 30*HZ;
6519 	net->ipv6.sysctl.ip6_rt_gc_elasticity = 9;
6520 	net->ipv6.sysctl.ip6_rt_mtu_expires = 10*60*HZ;
6521 	net->ipv6.sysctl.ip6_rt_min_advmss = IPV6_MIN_MTU - 20 - 40;
6522 	net->ipv6.sysctl.skip_notify_on_dev_down = 0;
6523 
6524 	atomic_set(&net->ipv6.ip6_rt_gc_expire, 30*HZ);
6525 
6526 	ret = 0;
6527 out:
6528 	return ret;
6529 
6530 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
6531 out_ip6_prohibit_entry:
6532 	kfree(net->ipv6.ip6_prohibit_entry);
6533 out_ip6_null_entry:
6534 	kfree(net->ipv6.ip6_null_entry);
6535 #endif
6536 out_fib6_null_entry:
6537 	kfree(net->ipv6.fib6_null_entry);
6538 out_ip6_dst_entries:
6539 	dst_entries_destroy(&net->ipv6.ip6_dst_ops);
6540 out_ip6_dst_ops:
6541 	goto out;
6542 }
6543 
ip6_route_net_exit(struct net * net)6544 static void __net_exit ip6_route_net_exit(struct net *net)
6545 {
6546 	kfree(net->ipv6.fib6_null_entry);
6547 	kfree(net->ipv6.ip6_null_entry);
6548 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
6549 	kfree(net->ipv6.ip6_prohibit_entry);
6550 	kfree(net->ipv6.ip6_blk_hole_entry);
6551 #endif
6552 	dst_entries_destroy(&net->ipv6.ip6_dst_ops);
6553 }
6554 
ip6_route_net_init_late(struct net * net)6555 static int __net_init ip6_route_net_init_late(struct net *net)
6556 {
6557 #ifdef CONFIG_PROC_FS
6558 	proc_create_net("ipv6_route", 0, net->proc_net, &ipv6_route_seq_ops,
6559 			sizeof(struct ipv6_route_iter));
6560 	proc_create_net_single("rt6_stats", 0444, net->proc_net,
6561 			rt6_stats_seq_show, NULL);
6562 #endif
6563 	return 0;
6564 }
6565 
ip6_route_net_exit_late(struct net * net)6566 static void __net_exit ip6_route_net_exit_late(struct net *net)
6567 {
6568 #ifdef CONFIG_PROC_FS
6569 	remove_proc_entry("ipv6_route", net->proc_net);
6570 	remove_proc_entry("rt6_stats", net->proc_net);
6571 #endif
6572 }
6573 
6574 static struct pernet_operations ip6_route_net_ops = {
6575 	.init = ip6_route_net_init,
6576 	.exit = ip6_route_net_exit,
6577 };
6578 
ipv6_inetpeer_init(struct net * net)6579 static int __net_init ipv6_inetpeer_init(struct net *net)
6580 {
6581 	struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL);
6582 
6583 	if (!bp)
6584 		return -ENOMEM;
6585 	inet_peer_base_init(bp);
6586 	net->ipv6.peers = bp;
6587 	return 0;
6588 }
6589 
ipv6_inetpeer_exit(struct net * net)6590 static void __net_exit ipv6_inetpeer_exit(struct net *net)
6591 {
6592 	struct inet_peer_base *bp = net->ipv6.peers;
6593 
6594 	net->ipv6.peers = NULL;
6595 	inetpeer_invalidate_tree(bp);
6596 	kfree(bp);
6597 }
6598 
6599 static struct pernet_operations ipv6_inetpeer_ops = {
6600 	.init	=	ipv6_inetpeer_init,
6601 	.exit	=	ipv6_inetpeer_exit,
6602 };
6603 
6604 static struct pernet_operations ip6_route_net_late_ops = {
6605 	.init = ip6_route_net_init_late,
6606 	.exit = ip6_route_net_exit_late,
6607 };
6608 
6609 static struct notifier_block ip6_route_dev_notifier = {
6610 	.notifier_call = ip6_route_dev_notify,
6611 	.priority = ADDRCONF_NOTIFY_PRIORITY - 10,
6612 };
6613 
ip6_route_init_special_entries(void)6614 void __init ip6_route_init_special_entries(void)
6615 {
6616 	/* Registering of the loopback is done before this portion of code,
6617 	 * the loopback reference in rt6_info will not be taken, do it
6618 	 * manually for init_net */
6619 	init_net.ipv6.fib6_null_entry->fib6_nh->fib_nh_dev = init_net.loopback_dev;
6620 	init_net.ipv6.ip6_null_entry->dst.dev = init_net.loopback_dev;
6621 	init_net.ipv6.ip6_null_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
6622   #ifdef CONFIG_IPV6_MULTIPLE_TABLES
6623 	init_net.ipv6.ip6_prohibit_entry->dst.dev = init_net.loopback_dev;
6624 	init_net.ipv6.ip6_prohibit_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
6625 	init_net.ipv6.ip6_blk_hole_entry->dst.dev = init_net.loopback_dev;
6626 	init_net.ipv6.ip6_blk_hole_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
6627   #endif
6628 }
6629 
6630 #if IS_BUILTIN(CONFIG_IPV6)
6631 #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS)
6632 DEFINE_BPF_ITER_FUNC(ipv6_route, struct bpf_iter_meta *meta, struct fib6_info *rt)
6633 
6634 BTF_ID_LIST(btf_fib6_info_id)
6635 BTF_ID(struct, fib6_info)
6636 
6637 static const struct bpf_iter_seq_info ipv6_route_seq_info = {
6638 	.seq_ops		= &ipv6_route_seq_ops,
6639 	.init_seq_private	= bpf_iter_init_seq_net,
6640 	.fini_seq_private	= bpf_iter_fini_seq_net,
6641 	.seq_priv_size		= sizeof(struct ipv6_route_iter),
6642 };
6643 
6644 static struct bpf_iter_reg ipv6_route_reg_info = {
6645 	.target			= "ipv6_route",
6646 	.ctx_arg_info_size	= 1,
6647 	.ctx_arg_info		= {
6648 		{ offsetof(struct bpf_iter__ipv6_route, rt),
6649 		  PTR_TO_BTF_ID_OR_NULL },
6650 	},
6651 	.seq_info		= &ipv6_route_seq_info,
6652 };
6653 
bpf_iter_register(void)6654 static int __init bpf_iter_register(void)
6655 {
6656 	ipv6_route_reg_info.ctx_arg_info[0].btf_id = *btf_fib6_info_id;
6657 	return bpf_iter_reg_target(&ipv6_route_reg_info);
6658 }
6659 
bpf_iter_unregister(void)6660 static void bpf_iter_unregister(void)
6661 {
6662 	bpf_iter_unreg_target(&ipv6_route_reg_info);
6663 }
6664 #endif
6665 #endif
6666 
ip6_route_init(void)6667 int __init ip6_route_init(void)
6668 {
6669 	int ret;
6670 	int cpu;
6671 
6672 	ret = -ENOMEM;
6673 	ip6_dst_ops_template.kmem_cachep =
6674 		kmem_cache_create("ip6_dst_cache", sizeof(struct rt6_info), 0,
6675 				  SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT, NULL);
6676 	if (!ip6_dst_ops_template.kmem_cachep)
6677 		goto out;
6678 
6679 	ret = dst_entries_init(&ip6_dst_blackhole_ops);
6680 	if (ret)
6681 		goto out_kmem_cache;
6682 
6683 	ret = register_pernet_subsys(&ipv6_inetpeer_ops);
6684 	if (ret)
6685 		goto out_dst_entries;
6686 
6687 	ret = register_pernet_subsys(&ip6_route_net_ops);
6688 	if (ret)
6689 		goto out_register_inetpeer;
6690 
6691 	ip6_dst_blackhole_ops.kmem_cachep = ip6_dst_ops_template.kmem_cachep;
6692 
6693 	ret = fib6_init();
6694 	if (ret)
6695 		goto out_register_subsys;
6696 
6697 	ret = xfrm6_init();
6698 	if (ret)
6699 		goto out_fib6_init;
6700 
6701 	ret = fib6_rules_init();
6702 	if (ret)
6703 		goto xfrm6_init;
6704 
6705 	ret = register_pernet_subsys(&ip6_route_net_late_ops);
6706 	if (ret)
6707 		goto fib6_rules_init;
6708 
6709 	ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_NEWROUTE,
6710 				   inet6_rtm_newroute, NULL, 0);
6711 	if (ret < 0)
6712 		goto out_register_late_subsys;
6713 
6714 	ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_DELROUTE,
6715 				   inet6_rtm_delroute, NULL, 0);
6716 	if (ret < 0)
6717 		goto out_register_late_subsys;
6718 
6719 	ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_GETROUTE,
6720 				   inet6_rtm_getroute, NULL,
6721 				   RTNL_FLAG_DOIT_UNLOCKED);
6722 	if (ret < 0)
6723 		goto out_register_late_subsys;
6724 
6725 	ret = register_netdevice_notifier(&ip6_route_dev_notifier);
6726 	if (ret)
6727 		goto out_register_late_subsys;
6728 
6729 #if IS_BUILTIN(CONFIG_IPV6)
6730 #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS)
6731 	ret = bpf_iter_register();
6732 	if (ret)
6733 		goto out_register_late_subsys;
6734 #endif
6735 #endif
6736 
6737 	for_each_possible_cpu(cpu) {
6738 		struct uncached_list *ul = per_cpu_ptr(&rt6_uncached_list, cpu);
6739 
6740 		INIT_LIST_HEAD(&ul->head);
6741 		INIT_LIST_HEAD(&ul->quarantine);
6742 		spin_lock_init(&ul->lock);
6743 	}
6744 
6745 out:
6746 	return ret;
6747 
6748 out_register_late_subsys:
6749 	rtnl_unregister_all(PF_INET6);
6750 	unregister_pernet_subsys(&ip6_route_net_late_ops);
6751 fib6_rules_init:
6752 	fib6_rules_cleanup();
6753 xfrm6_init:
6754 	xfrm6_fini();
6755 out_fib6_init:
6756 	fib6_gc_cleanup();
6757 out_register_subsys:
6758 	unregister_pernet_subsys(&ip6_route_net_ops);
6759 out_register_inetpeer:
6760 	unregister_pernet_subsys(&ipv6_inetpeer_ops);
6761 out_dst_entries:
6762 	dst_entries_destroy(&ip6_dst_blackhole_ops);
6763 out_kmem_cache:
6764 	kmem_cache_destroy(ip6_dst_ops_template.kmem_cachep);
6765 	goto out;
6766 }
6767 
ip6_route_cleanup(void)6768 void ip6_route_cleanup(void)
6769 {
6770 #if IS_BUILTIN(CONFIG_IPV6)
6771 #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS)
6772 	bpf_iter_unregister();
6773 #endif
6774 #endif
6775 	unregister_netdevice_notifier(&ip6_route_dev_notifier);
6776 	unregister_pernet_subsys(&ip6_route_net_late_ops);
6777 	fib6_rules_cleanup();
6778 	xfrm6_fini();
6779 	fib6_gc_cleanup();
6780 	unregister_pernet_subsys(&ipv6_inetpeer_ops);
6781 	unregister_pernet_subsys(&ip6_route_net_ops);
6782 	dst_entries_destroy(&ip6_dst_blackhole_ops);
6783 	kmem_cache_destroy(ip6_dst_ops_template.kmem_cachep);
6784 }
6785