1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _NET_IP6_ROUTE_H
3 #define _NET_IP6_ROUTE_H
4
5 struct route_info {
6 __u8 type;
7 __u8 length;
8 __u8 prefix_len;
9 #if defined(__BIG_ENDIAN_BITFIELD)
10 __u8 reserved_h:3,
11 route_pref:2,
12 reserved_l:3;
13 #elif defined(__LITTLE_ENDIAN_BITFIELD)
14 __u8 reserved_l:3,
15 route_pref:2,
16 reserved_h:3;
17 #endif
18 __be32 lifetime;
19 __u8 prefix[]; /* 0,8 or 16 */
20 };
21
22 #include <net/addrconf.h>
23 #include <net/flow.h>
24 #include <net/ip6_fib.h>
25 #include <net/sock.h>
26 #include <net/lwtunnel.h>
27 #include <linux/ip.h>
28 #include <linux/ipv6.h>
29 #include <linux/route.h>
30 #include <net/nexthop.h>
31
32 #define RT6_LOOKUP_F_IFACE 0x00000001
33 #define RT6_LOOKUP_F_REACHABLE 0x00000002
34 #define RT6_LOOKUP_F_HAS_SADDR 0x00000004
35 #define RT6_LOOKUP_F_SRCPREF_TMP 0x00000008
36 #define RT6_LOOKUP_F_SRCPREF_PUBLIC 0x00000010
37 #define RT6_LOOKUP_F_SRCPREF_COA 0x00000020
38 #define RT6_LOOKUP_F_IGNORE_LINKSTATE 0x00000040
39 #define RT6_LOOKUP_F_DST_NOREF 0x00000080
40
41 /* We do not (yet ?) support IPv6 jumbograms (RFC 2675)
42 * Unlike IPv4, hdr->seg_len doesn't include the IPv6 header
43 */
44 #define IP6_MAX_MTU (0xFFFF + sizeof(struct ipv6hdr))
45
46 /*
47 * rt6_srcprefs2flags() and rt6_flags2srcprefs() translate
48 * between IPV6_ADDR_PREFERENCES socket option values
49 * IPV6_PREFER_SRC_TMP = 0x1
50 * IPV6_PREFER_SRC_PUBLIC = 0x2
51 * IPV6_PREFER_SRC_COA = 0x4
52 * and above RT6_LOOKUP_F_SRCPREF_xxx flags.
53 */
rt6_srcprefs2flags(unsigned int srcprefs)54 static inline int rt6_srcprefs2flags(unsigned int srcprefs)
55 {
56 /* No need to bitmask because srcprefs have only 3 bits. */
57 return srcprefs << 3;
58 }
59
rt6_flags2srcprefs(int flags)60 static inline unsigned int rt6_flags2srcprefs(int flags)
61 {
62 return (flags >> 3) & 7;
63 }
64
rt6_need_strict(const struct in6_addr * daddr)65 static inline bool rt6_need_strict(const struct in6_addr *daddr)
66 {
67 return ipv6_addr_type(daddr) &
68 (IPV6_ADDR_MULTICAST | IPV6_ADDR_LINKLOCAL | IPV6_ADDR_LOOPBACK);
69 }
70
71 /* fib entries using a nexthop object can not be coalesced into
72 * a multipath route
73 */
rt6_qualify_for_ecmp(const struct fib6_info * f6i)74 static inline bool rt6_qualify_for_ecmp(const struct fib6_info *f6i)
75 {
76 /* the RTF_ADDRCONF flag filters out RA's */
77 return !(f6i->fib6_flags & RTF_ADDRCONF) && !f6i->nh &&
78 f6i->fib6_nh->fib_nh_gw_family;
79 }
80
81 void ip6_route_input(struct sk_buff *skb);
82 struct dst_entry *ip6_route_input_lookup(struct net *net,
83 struct net_device *dev,
84 struct flowi6 *fl6,
85 const struct sk_buff *skb, int flags);
86
87 struct dst_entry *ip6_route_output_flags_noref(struct net *net,
88 const struct sock *sk,
89 struct flowi6 *fl6, int flags);
90
91 struct dst_entry *ip6_route_output_flags(struct net *net, const struct sock *sk,
92 struct flowi6 *fl6, int flags);
93
ip6_route_output(struct net * net,const struct sock * sk,struct flowi6 * fl6)94 static inline struct dst_entry *ip6_route_output(struct net *net,
95 const struct sock *sk,
96 struct flowi6 *fl6)
97 {
98 return ip6_route_output_flags(net, sk, fl6, 0);
99 }
100
101 /* Only conditionally release dst if flags indicates
102 * !RT6_LOOKUP_F_DST_NOREF or dst is in uncached_list.
103 */
ip6_rt_put_flags(struct rt6_info * rt,int flags)104 static inline void ip6_rt_put_flags(struct rt6_info *rt, int flags)
105 {
106 if (!(flags & RT6_LOOKUP_F_DST_NOREF) ||
107 !list_empty(&rt->rt6i_uncached))
108 ip6_rt_put(rt);
109 }
110
111 struct dst_entry *ip6_route_lookup(struct net *net, struct flowi6 *fl6,
112 const struct sk_buff *skb, int flags);
113 struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table,
114 int ifindex, struct flowi6 *fl6,
115 const struct sk_buff *skb, int flags);
116
117 void ip6_route_init_special_entries(void);
118 int ip6_route_init(void);
119 void ip6_route_cleanup(void);
120
121 int ipv6_route_ioctl(struct net *net, unsigned int cmd,
122 struct in6_rtmsg *rtmsg);
123
124 int ip6_route_add(struct fib6_config *cfg, gfp_t gfp_flags,
125 struct netlink_ext_ack *extack);
126 int ip6_ins_rt(struct net *net, struct fib6_info *f6i);
127 int ip6_del_rt(struct net *net, struct fib6_info *f6i, bool skip_notify);
128
129 void rt6_flush_exceptions(struct fib6_info *f6i);
130 void rt6_age_exceptions(struct fib6_info *f6i, struct fib6_gc_args *gc_args,
131 unsigned long now);
132
ip6_route_get_saddr(struct net * net,struct fib6_info * f6i,const struct in6_addr * daddr,unsigned int prefs,struct in6_addr * saddr)133 static inline int ip6_route_get_saddr(struct net *net, struct fib6_info *f6i,
134 const struct in6_addr *daddr,
135 unsigned int prefs,
136 struct in6_addr *saddr)
137 {
138 int err = 0;
139
140 if (f6i && f6i->fib6_prefsrc.plen) {
141 *saddr = f6i->fib6_prefsrc.addr;
142 } else {
143 struct net_device *dev = f6i ? fib6_info_nh_dev(f6i) : NULL;
144
145 err = ipv6_dev_get_saddr(net, dev, daddr, prefs, saddr);
146 }
147
148 return err;
149 }
150
151 struct rt6_info *rt6_lookup(struct net *net, const struct in6_addr *daddr,
152 const struct in6_addr *saddr, int oif,
153 const struct sk_buff *skb, int flags);
154 u32 rt6_multipath_hash(const struct net *net, const struct flowi6 *fl6,
155 const struct sk_buff *skb, struct flow_keys *hkeys);
156
157 struct dst_entry *icmp6_dst_alloc(struct net_device *dev, struct flowi6 *fl6);
158
159 void fib6_force_start_gc(struct net *net);
160
161 struct fib6_info *addrconf_f6i_alloc(struct net *net, struct inet6_dev *idev,
162 const struct in6_addr *addr, bool anycast,
163 gfp_t gfp_flags);
164
165 struct rt6_info *ip6_dst_alloc(struct net *net, struct net_device *dev,
166 int flags);
167
168 /*
169 * support functions for ND
170 *
171 */
172 struct fib6_info *rt6_get_dflt_router(struct net *net,
173 const struct in6_addr *addr,
174 struct net_device *dev);
175 struct fib6_info *rt6_add_dflt_router(struct net *net,
176 const struct in6_addr *gwaddr,
177 struct net_device *dev, unsigned int pref,
178 u32 defrtr_usr_metric);
179
180 void rt6_purge_dflt_routers(struct net *net);
181
182 int rt6_route_rcv(struct net_device *dev, u8 *opt, int len,
183 const struct in6_addr *gwaddr);
184
185 void ip6_update_pmtu(struct sk_buff *skb, struct net *net, __be32 mtu, int oif,
186 u32 mark, kuid_t uid);
187 void ip6_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, __be32 mtu);
188 void ip6_redirect(struct sk_buff *skb, struct net *net, int oif, u32 mark,
189 kuid_t uid);
190 void ip6_redirect_no_header(struct sk_buff *skb, struct net *net, int oif);
191 void ip6_sk_redirect(struct sk_buff *skb, struct sock *sk);
192
193 struct netlink_callback;
194
195 struct rt6_rtnl_dump_arg {
196 struct sk_buff *skb;
197 struct netlink_callback *cb;
198 struct net *net;
199 struct fib_dump_filter filter;
200 };
201
202 int rt6_dump_route(struct fib6_info *f6i, void *p_arg, unsigned int skip);
203 void rt6_mtu_change(struct net_device *dev, unsigned int mtu);
204 void rt6_remove_prefsrc(struct inet6_ifaddr *ifp);
205 void rt6_clean_tohost(struct net *net, struct in6_addr *gateway);
206 void rt6_sync_up(struct net_device *dev, unsigned char nh_flags);
207 void rt6_disable_ip(struct net_device *dev, unsigned long event);
208 void rt6_sync_down_dev(struct net_device *dev, unsigned long event);
209 void rt6_multipath_rebalance(struct fib6_info *f6i);
210
211 void rt6_uncached_list_add(struct rt6_info *rt);
212 void rt6_uncached_list_del(struct rt6_info *rt);
213
skb_rt6_info(const struct sk_buff * skb)214 static inline const struct rt6_info *skb_rt6_info(const struct sk_buff *skb)
215 {
216 const struct dst_entry *dst = skb_dst(skb);
217 const struct rt6_info *rt6 = NULL;
218
219 if (dst)
220 rt6 = container_of(dst, struct rt6_info, dst);
221
222 return rt6;
223 }
224
225 /*
226 * Store a destination cache entry in a socket
227 */
ip6_dst_store(struct sock * sk,struct dst_entry * dst,const struct in6_addr * daddr,const struct in6_addr * saddr)228 static inline void ip6_dst_store(struct sock *sk, struct dst_entry *dst,
229 const struct in6_addr *daddr,
230 const struct in6_addr *saddr)
231 {
232 struct ipv6_pinfo *np = inet6_sk(sk);
233
234 np->dst_cookie = rt6_get_cookie((struct rt6_info *)dst);
235 sk_setup_caps(sk, dst);
236 np->daddr_cache = daddr;
237 #ifdef CONFIG_IPV6_SUBTREES
238 np->saddr_cache = saddr;
239 #endif
240 }
241
242 void ip6_sk_dst_store_flow(struct sock *sk, struct dst_entry *dst,
243 const struct flowi6 *fl6);
244
ipv6_unicast_destination(const struct sk_buff * skb)245 static inline bool ipv6_unicast_destination(const struct sk_buff *skb)
246 {
247 struct rt6_info *rt = (struct rt6_info *) skb_dst(skb);
248
249 return rt->rt6i_flags & RTF_LOCAL;
250 }
251
ipv6_anycast_destination(const struct dst_entry * dst,const struct in6_addr * daddr)252 static inline bool ipv6_anycast_destination(const struct dst_entry *dst,
253 const struct in6_addr *daddr)
254 {
255 struct rt6_info *rt = (struct rt6_info *)dst;
256
257 return rt->rt6i_flags & RTF_ANYCAST ||
258 (rt->rt6i_dst.plen < 127 &&
259 !(rt->rt6i_flags & (RTF_GATEWAY | RTF_NONEXTHOP)) &&
260 ipv6_addr_equal(&rt->rt6i_dst.addr, daddr));
261 }
262
263 int ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
264 int (*output)(struct net *, struct sock *, struct sk_buff *));
265
ip6_skb_dst_mtu(const struct sk_buff * skb)266 static inline unsigned int ip6_skb_dst_mtu(const struct sk_buff *skb)
267 {
268 const struct ipv6_pinfo *np = skb->sk && !dev_recursion_level() ?
269 inet6_sk(skb->sk) : NULL;
270 const struct dst_entry *dst = skb_dst(skb);
271 unsigned int mtu;
272
273 if (np && np->pmtudisc >= IPV6_PMTUDISC_PROBE) {
274 mtu = READ_ONCE(dst->dev->mtu);
275 mtu -= lwtunnel_headroom(dst->lwtstate, mtu);
276 } else {
277 mtu = dst_mtu(dst);
278 }
279 return mtu;
280 }
281
ip6_sk_accept_pmtu(const struct sock * sk)282 static inline bool ip6_sk_accept_pmtu(const struct sock *sk)
283 {
284 return inet6_sk(sk)->pmtudisc != IPV6_PMTUDISC_INTERFACE &&
285 inet6_sk(sk)->pmtudisc != IPV6_PMTUDISC_OMIT;
286 }
287
ip6_sk_ignore_df(const struct sock * sk)288 static inline bool ip6_sk_ignore_df(const struct sock *sk)
289 {
290 return inet6_sk(sk)->pmtudisc < IPV6_PMTUDISC_DO ||
291 inet6_sk(sk)->pmtudisc == IPV6_PMTUDISC_OMIT;
292 }
293
rt6_nexthop(const struct rt6_info * rt,const struct in6_addr * daddr)294 static inline const struct in6_addr *rt6_nexthop(const struct rt6_info *rt,
295 const struct in6_addr *daddr)
296 {
297 if (rt->rt6i_flags & RTF_GATEWAY)
298 return &rt->rt6i_gateway;
299 else if (unlikely(rt->rt6i_flags & RTF_CACHE))
300 return &rt->rt6i_dst.addr;
301 else
302 return daddr;
303 }
304
rt6_duplicate_nexthop(struct fib6_info * a,struct fib6_info * b)305 static inline bool rt6_duplicate_nexthop(struct fib6_info *a, struct fib6_info *b)
306 {
307 struct fib6_nh *nha, *nhb;
308
309 if (a->nh || b->nh)
310 return nexthop_cmp(a->nh, b->nh);
311
312 nha = a->fib6_nh;
313 nhb = b->fib6_nh;
314 return nha->fib_nh_dev == nhb->fib_nh_dev &&
315 ipv6_addr_equal(&nha->fib_nh_gw6, &nhb->fib_nh_gw6) &&
316 !lwtunnel_cmp_encap(nha->fib_nh_lws, nhb->fib_nh_lws);
317 }
318
ip6_dst_mtu_maybe_forward(const struct dst_entry * dst,bool forwarding)319 static inline unsigned int ip6_dst_mtu_maybe_forward(const struct dst_entry *dst,
320 bool forwarding)
321 {
322 struct inet6_dev *idev;
323 unsigned int mtu;
324
325 if (!forwarding || dst_metric_locked(dst, RTAX_MTU)) {
326 mtu = dst_metric_raw(dst, RTAX_MTU);
327 if (mtu)
328 goto out;
329 }
330
331 mtu = IPV6_MIN_MTU;
332 rcu_read_lock();
333 idev = __in6_dev_get(dst->dev);
334 if (idev)
335 mtu = idev->cnf.mtu6;
336 rcu_read_unlock();
337
338 out:
339 return mtu - lwtunnel_headroom(dst->lwtstate, mtu);
340 }
341
342 u32 ip6_mtu_from_fib6(const struct fib6_result *res,
343 const struct in6_addr *daddr,
344 const struct in6_addr *saddr);
345
346 struct neighbour *ip6_neigh_lookup(const struct in6_addr *gw,
347 struct net_device *dev, struct sk_buff *skb,
348 const void *daddr);
349 #endif
350