1 /* SPDX-License-Identifier: GPL-2.0-or-later */
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.
7 * Definitions for the IP router.
9 * Version: @(#)route.h 1.0.4 05/27/93
12 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
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
24 #include <net/inetpeer.h>
26 #include <net/inet_sock.h>
27 #include <net/ip_fib.h>
29 #include <net/ndisc.h>
30 #include <linux/in_route.h>
31 #include <linux/rtnetlink.h>
32 #include <linux/rcupdate.h>
33 #include <linux/route.h>
35 #include <linux/cache.h>
36 #include <linux/security.h>
38 #define RTO_ONLINK 0x01
40 #define RT_CONN_FLAGS(sk) (RT_TOS(READ_ONCE(inet_sk(sk)->tos)) | sock_flag(sk, SOCK_LOCALROUTE))
41 #define RT_CONN_FLAGS_TOS(sk,tos) (RT_TOS(tos) | sock_flag(sk, SOCK_LOCALROUTE))
43 static inline __u8 ip_sock_rt_scope(const struct sock *sk)
45 if (sock_flag(sk, SOCK_LOCALROUTE))
48 return RT_SCOPE_UNIVERSE;
51 static inline __u8 ip_sock_rt_tos(const struct sock *sk)
53 return RT_TOS(READ_ONCE(inet_sk(sk)->tos));
56 struct ip_tunnel_info;
64 unsigned int rt_flags;
72 /* Info on neighbour */
75 struct in6_addr rt_gw6;
78 /* Miscellaneous cached information */
83 static inline bool rt_is_input_route(const struct rtable *rt)
85 return rt->rt_is_input != 0;
88 static inline bool rt_is_output_route(const struct rtable *rt)
90 return rt->rt_is_input == 0;
93 static inline __be32 rt_nexthop(const struct rtable *rt, __be32 daddr)
95 if (rt->rt_gw_family == AF_INET)
107 struct rt_cache_stat {
108 unsigned int in_slow_tot;
109 unsigned int in_slow_mc;
110 unsigned int in_no_route;
112 unsigned int in_martian_dst;
113 unsigned int in_martian_src;
114 unsigned int out_slow_tot;
115 unsigned int out_slow_mc;
118 extern struct ip_rt_acct __percpu *ip_rt_acct;
122 int ip_rt_init(void);
123 void rt_cache_flush(struct net *net);
124 void rt_flush_dev(struct net_device *dev);
125 struct rtable *ip_route_output_key_hash(struct net *net, struct flowi4 *flp,
126 const struct sk_buff *skb);
127 struct rtable *ip_route_output_key_hash_rcu(struct net *net, struct flowi4 *flp,
128 struct fib_result *res,
129 const struct sk_buff *skb);
131 static inline struct rtable *__ip_route_output_key(struct net *net,
134 return ip_route_output_key_hash(net, flp, NULL);
137 struct rtable *ip_route_output_flow(struct net *, struct flowi4 *flp,
138 const struct sock *sk);
139 struct dst_entry *ipv4_blackhole_route(struct net *net,
140 struct dst_entry *dst_orig);
142 static inline struct rtable *ip_route_output_key(struct net *net, struct flowi4 *flp)
144 return ip_route_output_flow(net, flp, NULL);
147 static inline struct rtable *ip_route_output(struct net *net, __be32 daddr,
148 __be32 saddr, u8 tos, int oif)
150 struct flowi4 fl4 = {
156 return ip_route_output_key(net, &fl4);
159 static inline struct rtable *ip_route_output_ports(struct net *net, struct flowi4 *fl4,
160 const struct sock *sk,
161 __be32 daddr, __be32 saddr,
162 __be16 dport, __be16 sport,
163 __u8 proto, __u8 tos, int oif)
165 flowi4_init_output(fl4, oif, sk ? READ_ONCE(sk->sk_mark) : 0, tos,
166 RT_SCOPE_UNIVERSE, proto,
167 sk ? inet_sk_flowi_flags(sk) : 0,
168 daddr, saddr, dport, sport, sock_net_uid(net, sk));
170 security_sk_classify_flow(sk, flowi4_to_flowi_common(fl4));
171 return ip_route_output_flow(net, fl4, sk);
174 static inline struct rtable *ip_route_output_gre(struct net *net, struct flowi4 *fl4,
175 __be32 daddr, __be32 saddr,
176 __be32 gre_key, __u8 tos, int oif)
178 memset(fl4, 0, sizeof(*fl4));
179 fl4->flowi4_oif = oif;
182 fl4->flowi4_tos = tos;
183 fl4->flowi4_proto = IPPROTO_GRE;
184 fl4->fl4_gre_key = gre_key;
185 return ip_route_output_key(net, fl4);
187 int ip_mc_validate_source(struct sk_buff *skb, __be32 daddr, __be32 saddr,
188 u8 tos, struct net_device *dev,
189 struct in_device *in_dev, u32 *itag);
190 int ip_route_input_noref(struct sk_buff *skb, __be32 dst, __be32 src,
191 u8 tos, struct net_device *devin);
192 int ip_route_use_hint(struct sk_buff *skb, __be32 dst, __be32 src,
193 u8 tos, struct net_device *devin,
194 const struct sk_buff *hint);
196 static inline int ip_route_input(struct sk_buff *skb, __be32 dst, __be32 src,
197 u8 tos, struct net_device *devin)
202 err = ip_route_input_noref(skb, dst, src, tos, devin);
213 void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu, int oif,
215 void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu);
216 void ipv4_redirect(struct sk_buff *skb, struct net *net, int oif, u8 protocol);
217 void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk);
218 void ip_rt_send_redirect(struct sk_buff *skb);
220 unsigned int inet_addr_type(struct net *net, __be32 addr);
221 unsigned int inet_addr_type_table(struct net *net, __be32 addr, u32 tb_id);
222 unsigned int inet_dev_addr_type(struct net *net, const struct net_device *dev,
224 unsigned int inet_addr_type_dev_table(struct net *net,
225 const struct net_device *dev,
227 void ip_rt_multicast_event(struct in_device *);
228 int ip_rt_ioctl(struct net *, unsigned int cmd, struct rtentry *rt);
229 void ip_rt_get_source(u8 *src, struct sk_buff *skb, struct rtable *rt);
230 struct rtable *rt_dst_alloc(struct net_device *dev,
231 unsigned int flags, u16 type, bool noxfrm);
232 struct rtable *rt_dst_clone(struct net_device *dev, struct rtable *rt);
235 void fib_add_ifaddr(struct in_ifaddr *);
236 void fib_del_ifaddr(struct in_ifaddr *, struct in_ifaddr *);
237 void fib_modify_prefix_metric(struct in_ifaddr *ifa, u32 new_metric);
239 void rt_add_uncached_list(struct rtable *rt);
240 void rt_del_uncached_list(struct rtable *rt);
242 int fib_dump_info_fnhe(struct sk_buff *skb, struct netlink_callback *cb,
243 u32 table_id, struct fib_info *fi,
244 int *fa_index, int fa_start, unsigned int flags);
246 static inline void ip_rt_put(struct rtable *rt)
248 /* dst_release() accepts a NULL parameter.
249 * We rely on dst being first structure in struct rtable
251 BUILD_BUG_ON(offsetof(struct rtable, dst) != 0);
252 dst_release(&rt->dst);
255 #define IPTOS_RT_MASK (IPTOS_TOS_MASK & ~3)
257 extern const __u8 ip_tos2prio[16];
259 static inline char rt_tos2priority(u8 tos)
261 return ip_tos2prio[IPTOS_TOS(tos)>>1];
264 /* ip_route_connect() and ip_route_newports() work in tandem whilst
265 * binding a socket for a new outgoing connection.
267 * In order to use IPSEC properly, we must, in the end, have a
268 * route that was looked up using all available keys including source
269 * and destination ports.
271 * However, if a source port needs to be allocated (the user specified
272 * a wildcard source port) we need to obtain addressing information
273 * in order to perform that allocation.
275 * So ip_route_connect() looks up a route using wildcarded source and
276 * destination ports in the key, simply so that we can get a pair of
277 * addresses to use for port allocation.
279 * Later, once the ports are allocated, ip_route_newports() will make
280 * another route lookup if needed to make sure we catch any IPSEC
281 * rules keyed on the port information.
283 * The callers allocate the flow key on their stack, and must pass in
284 * the same flowi4 object to both the ip_route_connect() and the
285 * ip_route_newports() calls.
288 static inline void ip_route_connect_init(struct flowi4 *fl4, __be32 dst,
289 __be32 src, int oif, u8 protocol,
290 __be16 sport, __be16 dport,
291 const struct sock *sk)
295 if (inet_test_bit(TRANSPARENT, sk))
296 flow_flags |= FLOWI_FLAG_ANYSRC;
298 flowi4_init_output(fl4, oif, READ_ONCE(sk->sk_mark), ip_sock_rt_tos(sk),
299 ip_sock_rt_scope(sk), protocol, flow_flags, dst,
300 src, dport, sport, sk->sk_uid);
303 static inline struct rtable *ip_route_connect(struct flowi4 *fl4, __be32 dst,
304 __be32 src, int oif, u8 protocol,
305 __be16 sport, __be16 dport,
306 const struct sock *sk)
308 struct net *net = sock_net(sk);
311 ip_route_connect_init(fl4, dst, src, oif, protocol, sport, dport, sk);
314 rt = __ip_route_output_key(net, fl4);
318 flowi4_update_output(fl4, oif, fl4->daddr, fl4->saddr);
320 security_sk_classify_flow(sk, flowi4_to_flowi_common(fl4));
321 return ip_route_output_flow(net, fl4, sk);
324 static inline struct rtable *ip_route_newports(struct flowi4 *fl4, struct rtable *rt,
325 __be16 orig_sport, __be16 orig_dport,
326 __be16 sport, __be16 dport,
327 const struct sock *sk)
329 if (sport != orig_sport || dport != orig_dport) {
330 fl4->fl4_dport = dport;
331 fl4->fl4_sport = sport;
333 flowi4_update_output(fl4, sk->sk_bound_dev_if, fl4->daddr,
335 security_sk_classify_flow(sk, flowi4_to_flowi_common(fl4));
336 return ip_route_output_flow(sock_net(sk), fl4, sk);
341 static inline int inet_iif(const struct sk_buff *skb)
343 struct rtable *rt = skb_rtable(skb);
345 if (rt && rt->rt_iif)
351 static inline int ip4_dst_hoplimit(const struct dst_entry *dst)
353 int hoplimit = dst_metric_raw(dst, RTAX_HOPLIMIT);
354 struct net *net = dev_net(dst->dev);
357 hoplimit = READ_ONCE(net->ipv4.sysctl_ip_default_ttl);
361 static inline struct neighbour *ip_neigh_gw4(struct net_device *dev,
364 struct neighbour *neigh;
366 neigh = __ipv4_neigh_lookup_noref(dev, (__force u32)daddr);
367 if (unlikely(!neigh))
368 neigh = __neigh_create(&arp_tbl, &daddr, dev, false);
373 static inline struct neighbour *ip_neigh_for_gw(struct rtable *rt,
377 struct net_device *dev = rt->dst.dev;
378 struct neighbour *neigh;
380 if (likely(rt->rt_gw_family == AF_INET)) {
381 neigh = ip_neigh_gw4(dev, rt->rt_gw4);
382 } else if (rt->rt_gw_family == AF_INET6) {
383 neigh = ip_neigh_gw6(dev, &rt->rt_gw6);
386 neigh = ip_neigh_gw4(dev, ip_hdr(skb)->daddr);
391 #endif /* _ROUTE_H */