Commit | Line | Data |
---|---|---|
2874c5fd | 1 | /* SPDX-License-Identifier: GPL-2.0-or-later */ |
1da177e4 LT |
2 | /* |
3 | * INET An implementation of the TCP/IP protocol suite for the LINUX | |
4 | * operating system. INET is implemented using the BSD Socket | |
5 | * interface as the means of communication with the user level. | |
6 | * | |
7 | * Definitions for the IP router. | |
8 | * | |
9 | * Version: @(#)route.h 1.0.4 05/27/93 | |
10 | * | |
02c30a84 | 11 | * Authors: Ross Biro |
1da177e4 LT |
12 | * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> |
13 | * Fixes: | |
14 | * Alan Cox : Reformatted. Added ip_rt_local() | |
15 | * Alan Cox : Support for TCP parameters. | |
16 | * Alexey Kuznetsov: Major changes for new routing code. | |
17 | * Mike McLagan : Routing by source | |
18 | * Robert Olsson : Added rt_cache statistics | |
1da177e4 LT |
19 | */ |
20 | #ifndef _ROUTE_H | |
21 | #define _ROUTE_H | |
22 | ||
1da177e4 LT |
23 | #include <net/dst.h> |
24 | #include <net/inetpeer.h> | |
25 | #include <net/flow.h> | |
79876874 | 26 | #include <net/inet_sock.h> |
79a13159 | 27 | #include <net/ip_fib.h> |
5c9f7c1d DA |
28 | #include <net/arp.h> |
29 | #include <net/ndisc.h> | |
ff95cb5e | 30 | #include <net/inet_dscp.h> |
1dbdce30 | 31 | #include <net/sock.h> |
1da177e4 LT |
32 | #include <linux/in_route.h> |
33 | #include <linux/rtnetlink.h> | |
c6cffba4 | 34 | #include <linux/rcupdate.h> |
1da177e4 LT |
35 | #include <linux/route.h> |
36 | #include <linux/ip.h> | |
37 | #include <linux/cache.h> | |
beb8d13b | 38 | #include <linux/security.h> |
1da177e4 | 39 | |
67e1e2f4 GN |
40 | static inline __u8 ip_sock_rt_scope(const struct sock *sk) |
41 | { | |
42 | if (sock_flag(sk, SOCK_LOCALROUTE)) | |
43 | return RT_SCOPE_LINK; | |
44 | ||
45 | return RT_SCOPE_UNIVERSE; | |
46 | } | |
47 | ||
48 | static inline __u8 ip_sock_rt_tos(const struct sock *sk) | |
49 | { | |
ff95cb5e | 50 | return READ_ONCE(inet_sk(sk)->tos) & INET_DSCP_MASK; |
67e1e2f4 GN |
51 | } |
52 | ||
b6459415 | 53 | struct ip_tunnel_info; |
1da177e4 | 54 | struct fib_nh; |
62fa8a84 | 55 | struct fib_info; |
5055c371 | 56 | struct uncached_list; |
fd2c3ef7 | 57 | struct rtable { |
d8d1f30b | 58 | struct dst_entry dst; |
1da177e4 | 59 | |
29e75252 | 60 | int rt_genid; |
95c96174 | 61 | unsigned int rt_flags; |
1da177e4 | 62 | __u16 rt_type; |
155e8336 | 63 | __u8 rt_is_input; |
77d5bc7e | 64 | __u8 rt_uses_gateway; |
1da177e4 | 65 | |
1da177e4 LT |
66 | int rt_iif; |
67 | ||
77d5bc7e | 68 | u8 rt_gw_family; |
1da177e4 | 69 | /* Info on neighbour */ |
0f5f7d7b DA |
70 | union { |
71 | __be32 rt_gw4; | |
72 | struct in6_addr rt_gw6; | |
73 | }; | |
1da177e4 | 74 | |
1da177e4 | 75 | /* Miscellaneous cached information */ |
d52e5a7e SD |
76 | u32 rt_mtu_locked:1, |
77 | rt_pmtu:31; | |
1da177e4 LT |
78 | }; |
79 | ||
05d6d492 ED |
80 | #define dst_rtable(_ptr) container_of_const(_ptr, struct rtable, dst) |
81 | ||
82 | /** | |
83 | * skb_rtable - Returns the skb &rtable | |
84 | * @skb: buffer | |
85 | */ | |
86 | static inline struct rtable *skb_rtable(const struct sk_buff *skb) | |
87 | { | |
88 | return dst_rtable(skb_dst(skb)); | |
89 | } | |
90 | ||
b8400f37 | 91 | static inline bool rt_is_input_route(const struct rtable *rt) |
c7537967 | 92 | { |
9917e1e8 | 93 | return rt->rt_is_input != 0; |
c7537967 DM |
94 | } |
95 | ||
b8400f37 | 96 | static inline bool rt_is_output_route(const struct rtable *rt) |
c7537967 | 97 | { |
9917e1e8 | 98 | return rt->rt_is_input == 0; |
c7537967 DM |
99 | } |
100 | ||
f8126f1d DM |
101 | static inline __be32 rt_nexthop(const struct rtable *rt, __be32 daddr) |
102 | { | |
1550c171 DA |
103 | if (rt->rt_gw_family == AF_INET) |
104 | return rt->rt_gw4; | |
f8126f1d DM |
105 | return daddr; |
106 | } | |
107 | ||
fd2c3ef7 | 108 | struct ip_rt_acct { |
1da177e4 LT |
109 | __u32 o_bytes; |
110 | __u32 o_packets; | |
111 | __u32 i_bytes; | |
112 | __u32 i_packets; | |
113 | }; | |
114 | ||
fd2c3ef7 | 115 | struct rt_cache_stat { |
1da177e4 LT |
116 | unsigned int in_slow_tot; |
117 | unsigned int in_slow_mc; | |
118 | unsigned int in_no_route; | |
119 | unsigned int in_brd; | |
120 | unsigned int in_martian_dst; | |
121 | unsigned int in_martian_src; | |
1da177e4 LT |
122 | unsigned int out_slow_tot; |
123 | unsigned int out_slow_mc; | |
1da177e4 LT |
124 | }; |
125 | ||
7d720c3e | 126 | extern struct ip_rt_acct __percpu *ip_rt_acct; |
1da177e4 LT |
127 | |
128 | struct in_device; | |
2702c4bb JP |
129 | |
130 | int ip_rt_init(void); | |
131 | void rt_cache_flush(struct net *net); | |
132 | void rt_flush_dev(struct net_device *dev); | |
1dbdce30 GN |
133 | |
134 | static inline void inet_sk_init_flowi4(const struct inet_sock *inet, | |
135 | struct flowi4 *fl4) | |
136 | { | |
137 | const struct ip_options_rcu *ip4_opt; | |
138 | const struct sock *sk; | |
139 | __be32 daddr; | |
140 | ||
141 | rcu_read_lock(); | |
142 | ip4_opt = rcu_dereference(inet->inet_opt); | |
143 | ||
144 | /* Source routing option overrides the socket destination address */ | |
145 | if (ip4_opt && ip4_opt->opt.srr) | |
146 | daddr = ip4_opt->opt.faddr; | |
147 | else | |
148 | daddr = inet->inet_daddr; | |
149 | rcu_read_unlock(); | |
150 | ||
151 | sk = &inet->sk; | |
152 | flowi4_init_output(fl4, sk->sk_bound_dev_if, READ_ONCE(sk->sk_mark), | |
153 | ip_sock_rt_tos(sk), ip_sock_rt_scope(sk), | |
154 | sk->sk_protocol, inet_sk_flowi_flags(sk), daddr, | |
155 | inet->inet_saddr, inet->inet_dport, | |
156 | inet->inet_sport, sk->sk_uid); | |
157 | security_sk_classify_flow(sk, flowi4_to_flowi_common(fl4)); | |
158 | } | |
159 | ||
3abd1ade DA |
160 | struct rtable *ip_route_output_key_hash(struct net *net, struct flowi4 *flp, |
161 | const struct sk_buff *skb); | |
162 | struct rtable *ip_route_output_key_hash_rcu(struct net *net, struct flowi4 *flp, | |
163 | struct fib_result *res, | |
164 | const struct sk_buff *skb); | |
79a13159 PN |
165 | |
166 | static inline struct rtable *__ip_route_output_key(struct net *net, | |
167 | struct flowi4 *flp) | |
168 | { | |
3abd1ade | 169 | return ip_route_output_key_hash(net, flp, NULL); |
79a13159 PN |
170 | } |
171 | ||
2702c4bb | 172 | struct rtable *ip_route_output_flow(struct net *, struct flowi4 *flp, |
6f9c9615 | 173 | const struct sock *sk); |
2702c4bb JP |
174 | struct dst_entry *ipv4_blackhole_route(struct net *net, |
175 | struct dst_entry *dst_orig); | |
407eadd9 | 176 | |
9d6ec938 | 177 | static inline struct rtable *ip_route_output_key(struct net *net, struct flowi4 *flp) |
5bfa787f DM |
178 | { |
179 | return ip_route_output_flow(net, flp, NULL); | |
180 | } | |
181 | ||
ec20b283 GN |
182 | /* Simplistic IPv4 route lookup function. |
183 | * This is only suitable for some particular use cases: since the flowi4 | |
184 | * structure is only partially set, it may bypass some fib-rules. | |
185 | */ | |
78fbfd8a | 186 | static inline struct rtable *ip_route_output(struct net *net, __be32 daddr, |
48171c65 GN |
187 | __be32 saddr, dscp_t dscp, |
188 | int oif, __u8 scope) | |
78fbfd8a | 189 | { |
9d6ec938 DM |
190 | struct flowi4 fl4 = { |
191 | .flowi4_oif = oif, | |
48171c65 | 192 | .flowi4_tos = inet_dscp_to_dsfield(dscp), |
ec20b283 | 193 | .flowi4_scope = scope, |
9d6ec938 DM |
194 | .daddr = daddr, |
195 | .saddr = saddr, | |
78fbfd8a | 196 | }; |
ec20b283 | 197 | |
9d6ec938 | 198 | return ip_route_output_key(net, &fl4); |
78fbfd8a DM |
199 | } |
200 | ||
31e4543d | 201 | static inline struct rtable *ip_route_output_ports(struct net *net, struct flowi4 *fl4, |
8d6eba33 | 202 | const struct sock *sk, |
78fbfd8a DM |
203 | __be32 daddr, __be32 saddr, |
204 | __be16 dport, __be16 sport, | |
205 | __u8 proto, __u8 tos, int oif) | |
206 | { | |
3c5b4d69 | 207 | flowi4_init_output(fl4, oif, sk ? READ_ONCE(sk->sk_mark) : 0, tos, |
a3522a2e GN |
208 | sk ? ip_sock_rt_scope(sk) : RT_SCOPE_UNIVERSE, |
209 | proto, sk ? inet_sk_flowi_flags(sk) : 0, | |
e2d118a1 | 210 | daddr, saddr, dport, sport, sock_net_uid(net, sk)); |
78fbfd8a | 211 | if (sk) |
3df98d79 | 212 | security_sk_classify_flow(sk, flowi4_to_flowi_common(fl4)); |
31e4543d | 213 | return ip_route_output_flow(net, fl4, sk); |
78fbfd8a DM |
214 | } |
215 | ||
d46f8270 MD |
216 | enum skb_drop_reason |
217 | ip_mc_validate_source(struct sk_buff *skb, __be32 daddr, __be32 saddr, | |
218 | dscp_t dscp, struct net_device *dev, | |
219 | struct in_device *in_dev, u32 *itag); | |
82d9983e MD |
220 | enum skb_drop_reason |
221 | ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr, | |
222 | dscp_t dscp, struct net_device *dev); | |
479aed04 MD |
223 | enum skb_drop_reason |
224 | ip_route_use_hint(struct sk_buff *skb, __be32 daddr, __be32 saddr, | |
225 | dscp_t dscp, struct net_device *dev, | |
226 | const struct sk_buff *hint); | |
02b24941 | 227 | |
50038bf3 MD |
228 | static inline enum skb_drop_reason |
229 | ip_route_input(struct sk_buff *skb, __be32 dst, __be32 src, dscp_t dscp, | |
230 | struct net_device *devin) | |
c6cffba4 | 231 | { |
82d9983e | 232 | enum skb_drop_reason reason; |
c6cffba4 DM |
233 | |
234 | rcu_read_lock(); | |
82d9983e MD |
235 | reason = ip_route_input_noref(skb, dst, src, dscp, devin); |
236 | if (!reason) { | |
222d7dbd | 237 | skb_dst_force(skb); |
64327fc8 | 238 | if (!skb_dst(skb)) |
82d9983e | 239 | reason = SKB_DROP_REASON_NOT_SPECIFIED; |
64327fc8 | 240 | } |
c6cffba4 DM |
241 | rcu_read_unlock(); |
242 | ||
50038bf3 | 243 | return reason; |
c6cffba4 | 244 | } |
407eadd9 | 245 | |
2702c4bb | 246 | void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu, int oif, |
d888f396 | 247 | u8 protocol); |
2702c4bb | 248 | void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu); |
1042caa7 | 249 | void ipv4_redirect(struct sk_buff *skb, struct net *net, int oif, u8 protocol); |
2702c4bb JP |
250 | void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk); |
251 | void ip_rt_send_redirect(struct sk_buff *skb); | |
252 | ||
253 | unsigned int inet_addr_type(struct net *net, __be32 addr); | |
9b8ff518 | 254 | unsigned int inet_addr_type_table(struct net *net, __be32 addr, u32 tb_id); |
2702c4bb JP |
255 | unsigned int inet_dev_addr_type(struct net *net, const struct net_device *dev, |
256 | __be32 addr); | |
30bbaa19 DA |
257 | unsigned int inet_addr_type_dev_table(struct net *net, |
258 | const struct net_device *dev, | |
259 | __be32 addr); | |
2702c4bb | 260 | void ip_rt_multicast_event(struct in_device *); |
ca25c300 | 261 | int ip_rt_ioctl(struct net *, unsigned int cmd, struct rtentry *rt); |
2702c4bb | 262 | void ip_rt_get_source(u8 *src, struct sk_buff *skb, struct rtable *rt); |
9ab179d8 | 263 | struct rtable *rt_dst_alloc(struct net_device *dev, |
b5c8b3fe | 264 | unsigned int flags, u16 type, bool noxfrm); |
5b18f128 | 265 | struct rtable *rt_dst_clone(struct net_device *dev, struct rtable *rt); |
1da177e4 | 266 | |
0ff60a45 | 267 | struct in_ifaddr; |
2702c4bb JP |
268 | void fib_add_ifaddr(struct in_ifaddr *); |
269 | void fib_del_ifaddr(struct in_ifaddr *, struct in_ifaddr *); | |
af4d768a | 270 | void fib_modify_prefix_metric(struct in_ifaddr *ifa, u32 new_metric); |
0ff60a45 | 271 | |
510c321b XL |
272 | void rt_add_uncached_list(struct rtable *rt); |
273 | void rt_del_uncached_list(struct rtable *rt); | |
274 | ||
ee28906f SB |
275 | int fib_dump_info_fnhe(struct sk_buff *skb, struct netlink_callback *cb, |
276 | u32 table_id, struct fib_info *fi, | |
e93fb3e9 | 277 | int *fa_index, int fa_start, unsigned int flags); |
ee28906f | 278 | |
6da025fa | 279 | static inline void ip_rt_put(struct rtable *rt) |
1da177e4 | 280 | { |
6da025fa ED |
281 | /* dst_release() accepts a NULL parameter. |
282 | * We rely on dst being first structure in struct rtable | |
283 | */ | |
284 | BUILD_BUG_ON(offsetof(struct rtable, dst) != 0); | |
285 | dst_release(&rt->dst); | |
1da177e4 LT |
286 | } |
287 | ||
4839c52b | 288 | extern const __u8 ip_tos2prio[16]; |
1da177e4 LT |
289 | |
290 | static inline char rt_tos2priority(u8 tos) | |
291 | { | |
292 | return ip_tos2prio[IPTOS_TOS(tos)>>1]; | |
293 | } | |
294 | ||
2d7192d6 DM |
295 | /* ip_route_connect() and ip_route_newports() work in tandem whilst |
296 | * binding a socket for a new outgoing connection. | |
297 | * | |
298 | * In order to use IPSEC properly, we must, in the end, have a | |
299 | * route that was looked up using all available keys including source | |
300 | * and destination ports. | |
301 | * | |
302 | * However, if a source port needs to be allocated (the user specified | |
303 | * a wildcard source port) we need to obtain addressing information | |
304 | * in order to perform that allocation. | |
305 | * | |
306 | * So ip_route_connect() looks up a route using wildcarded source and | |
307 | * destination ports in the key, simply so that we can get a pair of | |
308 | * addresses to use for port allocation. | |
309 | * | |
310 | * Later, once the ports are allocated, ip_route_newports() will make | |
311 | * another route lookup if needed to make sure we catch any IPSEC | |
312 | * rules keyed on the port information. | |
313 | * | |
314 | * The callers allocate the flow key on their stack, and must pass in | |
315 | * the same flowi4 object to both the ip_route_connect() and the | |
316 | * ip_route_newports() calls. | |
317 | */ | |
318 | ||
67e1e2f4 GN |
319 | static inline void ip_route_connect_init(struct flowi4 *fl4, __be32 dst, |
320 | __be32 src, int oif, u8 protocol, | |
2d7192d6 | 321 | __be16 sport, __be16 dport, |
67e1e2f4 | 322 | const struct sock *sk) |
1da177e4 | 323 | { |
2d7192d6 | 324 | __u8 flow_flags = 0; |
79876874 | 325 | |
4bd0623f | 326 | if (inet_test_bit(TRANSPARENT, sk)) |
94b92b88 | 327 | flow_flags |= FLOWI_FLAG_ANYSRC; |
94b92b88 | 328 | |
65e90246 WB |
329 | if (IS_ENABLED(CONFIG_IP_ROUTE_MULTIPATH) && !sport) |
330 | flow_flags |= FLOWI_FLAG_ANY_SPORT; | |
331 | ||
3c5b4d69 | 332 | flowi4_init_output(fl4, oif, READ_ONCE(sk->sk_mark), ip_sock_rt_tos(sk), |
67e1e2f4 GN |
333 | ip_sock_rt_scope(sk), protocol, flow_flags, dst, |
334 | src, dport, sport, sk->sk_uid); | |
2d7192d6 DM |
335 | } |
336 | ||
67e1e2f4 GN |
337 | static inline struct rtable *ip_route_connect(struct flowi4 *fl4, __be32 dst, |
338 | __be32 src, int oif, u8 protocol, | |
2d7192d6 | 339 | __be16 sport, __be16 dport, |
8d6eba33 | 340 | const struct sock *sk) |
2d7192d6 DM |
341 | { |
342 | struct net *net = sock_net(sk); | |
343 | struct rtable *rt; | |
344 | ||
67e1e2f4 | 345 | ip_route_connect_init(fl4, dst, src, oif, protocol, sport, dport, sk); |
79876874 | 346 | |
1da177e4 | 347 | if (!dst || !src) { |
2d7192d6 | 348 | rt = __ip_route_output_key(net, fl4); |
b23dd4fe DM |
349 | if (IS_ERR(rt)) |
350 | return rt; | |
b23dd4fe | 351 | ip_rt_put(rt); |
3f06760c | 352 | flowi4_update_output(fl4, oif, fl4->daddr, fl4->saddr); |
1da177e4 | 353 | } |
3df98d79 | 354 | security_sk_classify_flow(sk, flowi4_to_flowi_common(fl4)); |
2d7192d6 | 355 | return ip_route_output_flow(net, fl4, sk); |
1da177e4 LT |
356 | } |
357 | ||
2d7192d6 DM |
358 | static inline struct rtable *ip_route_newports(struct flowi4 *fl4, struct rtable *rt, |
359 | __be16 orig_sport, __be16 orig_dport, | |
360 | __be16 sport, __be16 dport, | |
8d6eba33 | 361 | const struct sock *sk) |
1da177e4 | 362 | { |
dca8b089 | 363 | if (sport != orig_sport || dport != orig_dport) { |
2d7192d6 DM |
364 | fl4->fl4_dport = dport; |
365 | fl4->fl4_sport = sport; | |
b23dd4fe | 366 | ip_rt_put(rt); |
3f06760c | 367 | flowi4_update_output(fl4, sk->sk_bound_dev_if, fl4->daddr, |
e6b45241 | 368 | fl4->saddr); |
3df98d79 | 369 | security_sk_classify_flow(sk, flowi4_to_flowi_common(fl4)); |
2d7192d6 | 370 | return ip_route_output_flow(sock_net(sk), fl4, sk); |
1da177e4 | 371 | } |
b23dd4fe | 372 | return rt; |
1da177e4 LT |
373 | } |
374 | ||
1668e010 KK |
375 | static inline int inet_iif(const struct sk_buff *skb) |
376 | { | |
0340d0b9 TH |
377 | struct rtable *rt = skb_rtable(skb); |
378 | ||
379 | if (rt && rt->rt_iif) | |
380 | return rt->rt_iif; | |
13378cad | 381 | |
13378cad | 382 | return skb->skb_iif; |
1668e010 KK |
383 | } |
384 | ||
323e126f DM |
385 | static inline int ip4_dst_hoplimit(const struct dst_entry *dst) |
386 | { | |
387 | int hoplimit = dst_metric_raw(dst, RTAX_HOPLIMIT); | |
388 | ||
46930855 ED |
389 | if (hoplimit == 0) { |
390 | const struct net *net; | |
391 | ||
392 | rcu_read_lock(); | |
393 | net = dev_net_rcu(dst->dev); | |
8281b7ec | 394 | hoplimit = READ_ONCE(net->ipv4.sysctl_ip_default_ttl); |
46930855 ED |
395 | rcu_read_unlock(); |
396 | } | |
323e126f DM |
397 | return hoplimit; |
398 | } | |
399 | ||
5c9f7c1d DA |
400 | static inline struct neighbour *ip_neigh_gw4(struct net_device *dev, |
401 | __be32 daddr) | |
402 | { | |
403 | struct neighbour *neigh; | |
404 | ||
3c42b201 | 405 | neigh = __ipv4_neigh_lookup_noref(dev, (__force u32)daddr); |
5c9f7c1d DA |
406 | if (unlikely(!neigh)) |
407 | neigh = __neigh_create(&arp_tbl, &daddr, dev, false); | |
408 | ||
409 | return neigh; | |
410 | } | |
411 | ||
412 | static inline struct neighbour *ip_neigh_for_gw(struct rtable *rt, | |
413 | struct sk_buff *skb, | |
414 | bool *is_v6gw) | |
415 | { | |
416 | struct net_device *dev = rt->dst.dev; | |
417 | struct neighbour *neigh; | |
418 | ||
419 | if (likely(rt->rt_gw_family == AF_INET)) { | |
420 | neigh = ip_neigh_gw4(dev, rt->rt_gw4); | |
421 | } else if (rt->rt_gw_family == AF_INET6) { | |
422 | neigh = ip_neigh_gw6(dev, &rt->rt_gw6); | |
423 | *is_v6gw = true; | |
424 | } else { | |
425 | neigh = ip_neigh_gw4(dev, ip_hdr(skb)->daddr); | |
426 | } | |
427 | return neigh; | |
428 | } | |
429 | ||
1da177e4 | 430 | #endif /* _ROUTE_H */ |