1 /* 2 * INET An implementation of the TCP/IP protocol suite for the LINUX 3 * operating system. INET is implemented using the BSD Socket 4 * interface as the means of communication with the user level. 5 * 6 * Definitions for the IP router. 7 * 8 * Version: @(#)route.h 1.0.4 05/27/93 9 * 10 * Authors: Ross Biro 11 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> 12 * Fixes: 13 * Alan Cox : Reformatted. Added ip_rt_local() 14 * Alan Cox : Support for TCP parameters. 15 * Alexey Kuznetsov: Major changes for new routing code. 16 * Mike McLagan : Routing by source 17 * Robert Olsson : Added rt_cache statistics 18 * 19 * This program is free software; you can redistribute it and/or 20 * modify it under the terms of the GNU General Public License 21 * as published by the Free Software Foundation; either version 22 * 2 of the License, or (at your option) any later version. 23 */ 24 #ifndef _ROUTE_H 25 #define _ROUTE_H 26 27 #include <net/dst.h> 28 #include <net/inetpeer.h> 29 #include <net/flow.h> 30 #include <net/inet_sock.h> 31 #include <linux/in_route.h> 32 #include <linux/rtnetlink.h> 33 #include <linux/route.h> 34 #include <linux/ip.h> 35 #include <linux/cache.h> 36 #include <linux/security.h> 37 38 #define RTO_ONLINK 0x01 39 40 #define RT_CONN_FLAGS(sk) (RT_TOS(inet_sk(sk)->tos) | sock_flag(sk, SOCK_LOCALROUTE)) 41 42 struct fib_nh; 43 struct inet_peer; 44 struct fib_info; 45 struct rtable { 46 struct dst_entry dst; 47 48 /* Lookup key. */ 49 __be32 rt_key_dst; 50 __be32 rt_key_src; 51 52 int rt_genid; 53 unsigned int rt_flags; 54 __u16 rt_type; 55 __u8 rt_key_tos; 56 57 __be32 rt_dst; /* Path destination */ 58 __be32 rt_src; /* Path source */ 59 int rt_route_iif; 60 int rt_iif; 61 int rt_oif; 62 __u32 rt_mark; 63 64 /* Info on neighbour */ 65 __be32 rt_gateway; 66 67 /* Miscellaneous cached information */ 68 __be32 rt_spec_dst; /* RFC1122 specific destination */ 69 u32 rt_peer_genid; 70 unsigned long _peer; /* long-living peer info */ 71 struct fib_info *fi; /* for client ref to shared metrics */ 72 }; 73 74 static inline struct inet_peer *rt_peer_ptr(struct rtable *rt) 75 { 76 return inetpeer_ptr(rt->_peer); 77 } 78 79 static inline bool rt_has_peer(struct rtable *rt) 80 { 81 return inetpeer_ptr_is_peer(rt->_peer); 82 } 83 84 static inline void __rt_set_peer(struct rtable *rt, struct inet_peer *peer) 85 { 86 __inetpeer_ptr_set_peer(&rt->_peer, peer); 87 } 88 89 static inline bool rt_set_peer(struct rtable *rt, struct inet_peer *peer) 90 { 91 return inetpeer_ptr_set_peer(&rt->_peer, peer); 92 } 93 94 static inline void rt_init_peer(struct rtable *rt, struct inet_peer_base *base) 95 { 96 inetpeer_init_ptr(&rt->_peer, base); 97 } 98 99 static inline void rt_transfer_peer(struct rtable *rt, struct rtable *ort) 100 { 101 rt->_peer = ort->_peer; 102 if (rt_has_peer(ort)) { 103 struct inet_peer *peer = rt_peer_ptr(ort); 104 atomic_inc(&peer->refcnt); 105 } 106 } 107 108 static inline bool rt_is_input_route(const struct rtable *rt) 109 { 110 return rt->rt_route_iif != 0; 111 } 112 113 static inline bool rt_is_output_route(const struct rtable *rt) 114 { 115 return rt->rt_route_iif == 0; 116 } 117 118 struct ip_rt_acct { 119 __u32 o_bytes; 120 __u32 o_packets; 121 __u32 i_bytes; 122 __u32 i_packets; 123 }; 124 125 struct rt_cache_stat { 126 unsigned int in_hit; 127 unsigned int in_slow_tot; 128 unsigned int in_slow_mc; 129 unsigned int in_no_route; 130 unsigned int in_brd; 131 unsigned int in_martian_dst; 132 unsigned int in_martian_src; 133 unsigned int out_hit; 134 unsigned int out_slow_tot; 135 unsigned int out_slow_mc; 136 unsigned int gc_total; 137 unsigned int gc_ignored; 138 unsigned int gc_goal_miss; 139 unsigned int gc_dst_overflow; 140 unsigned int in_hlist_search; 141 unsigned int out_hlist_search; 142 }; 143 144 extern struct ip_rt_acct __percpu *ip_rt_acct; 145 146 struct in_device; 147 extern int ip_rt_init(void); 148 extern void ip_rt_redirect(__be32 old_gw, __be32 dst, __be32 new_gw, 149 __be32 src, struct net_device *dev); 150 extern void rt_cache_flush(struct net *net, int how); 151 extern void rt_cache_flush_batch(struct net *net); 152 extern struct rtable *__ip_route_output_key(struct net *, struct flowi4 *flp); 153 extern struct rtable *ip_route_output_flow(struct net *, struct flowi4 *flp, 154 struct sock *sk); 155 extern struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig); 156 157 static inline struct rtable *ip_route_output_key(struct net *net, struct flowi4 *flp) 158 { 159 return ip_route_output_flow(net, flp, NULL); 160 } 161 162 static inline struct rtable *ip_route_output(struct net *net, __be32 daddr, 163 __be32 saddr, u8 tos, int oif) 164 { 165 struct flowi4 fl4 = { 166 .flowi4_oif = oif, 167 .flowi4_tos = tos, 168 .daddr = daddr, 169 .saddr = saddr, 170 }; 171 return ip_route_output_key(net, &fl4); 172 } 173 174 static inline struct rtable *ip_route_output_ports(struct net *net, struct flowi4 *fl4, 175 struct sock *sk, 176 __be32 daddr, __be32 saddr, 177 __be16 dport, __be16 sport, 178 __u8 proto, __u8 tos, int oif) 179 { 180 flowi4_init_output(fl4, oif, sk ? sk->sk_mark : 0, tos, 181 RT_SCOPE_UNIVERSE, proto, 182 sk ? inet_sk_flowi_flags(sk) : 0, 183 daddr, saddr, dport, sport); 184 if (sk) 185 security_sk_classify_flow(sk, flowi4_to_flowi(fl4)); 186 return ip_route_output_flow(net, fl4, sk); 187 } 188 189 static inline struct rtable *ip_route_output_gre(struct net *net, struct flowi4 *fl4, 190 __be32 daddr, __be32 saddr, 191 __be32 gre_key, __u8 tos, int oif) 192 { 193 memset(fl4, 0, sizeof(*fl4)); 194 fl4->flowi4_oif = oif; 195 fl4->daddr = daddr; 196 fl4->saddr = saddr; 197 fl4->flowi4_tos = tos; 198 fl4->flowi4_proto = IPPROTO_GRE; 199 fl4->fl4_gre_key = gre_key; 200 return ip_route_output_key(net, fl4); 201 } 202 203 extern int ip_route_input_common(struct sk_buff *skb, __be32 dst, __be32 src, 204 u8 tos, struct net_device *devin, bool noref, bool nocache); 205 206 static inline int ip_route_input(struct sk_buff *skb, __be32 dst, __be32 src, 207 u8 tos, struct net_device *devin) 208 { 209 return ip_route_input_common(skb, dst, src, tos, devin, false, false); 210 } 211 212 static inline int ip_route_input_noref(struct sk_buff *skb, __be32 dst, __be32 src, 213 u8 tos, struct net_device *devin, bool nocache) 214 { 215 return ip_route_input_common(skb, dst, src, tos, devin, true, nocache); 216 } 217 218 extern void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu, 219 int oif, u32 mark, u8 protocol, int flow_flags); 220 extern void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu); 221 extern void ip_rt_send_redirect(struct sk_buff *skb); 222 223 extern unsigned int inet_addr_type(struct net *net, __be32 addr); 224 extern unsigned int inet_dev_addr_type(struct net *net, const struct net_device *dev, __be32 addr); 225 extern void ip_rt_multicast_event(struct in_device *); 226 extern int ip_rt_ioctl(struct net *, unsigned int cmd, void __user *arg); 227 extern void ip_rt_get_source(u8 *src, struct sk_buff *skb, struct rtable *rt); 228 extern int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb); 229 230 struct in_ifaddr; 231 extern void fib_add_ifaddr(struct in_ifaddr *); 232 extern void fib_del_ifaddr(struct in_ifaddr *, struct in_ifaddr *); 233 234 static inline void ip_rt_put(struct rtable * rt) 235 { 236 if (rt) 237 dst_release(&rt->dst); 238 } 239 240 #define IPTOS_RT_MASK (IPTOS_TOS_MASK & ~3) 241 242 extern const __u8 ip_tos2prio[16]; 243 244 static inline char rt_tos2priority(u8 tos) 245 { 246 return ip_tos2prio[IPTOS_TOS(tos)>>1]; 247 } 248 249 /* ip_route_connect() and ip_route_newports() work in tandem whilst 250 * binding a socket for a new outgoing connection. 251 * 252 * In order to use IPSEC properly, we must, in the end, have a 253 * route that was looked up using all available keys including source 254 * and destination ports. 255 * 256 * However, if a source port needs to be allocated (the user specified 257 * a wildcard source port) we need to obtain addressing information 258 * in order to perform that allocation. 259 * 260 * So ip_route_connect() looks up a route using wildcarded source and 261 * destination ports in the key, simply so that we can get a pair of 262 * addresses to use for port allocation. 263 * 264 * Later, once the ports are allocated, ip_route_newports() will make 265 * another route lookup if needed to make sure we catch any IPSEC 266 * rules keyed on the port information. 267 * 268 * The callers allocate the flow key on their stack, and must pass in 269 * the same flowi4 object to both the ip_route_connect() and the 270 * ip_route_newports() calls. 271 */ 272 273 static inline void ip_route_connect_init(struct flowi4 *fl4, __be32 dst, __be32 src, 274 u32 tos, int oif, u8 protocol, 275 __be16 sport, __be16 dport, 276 struct sock *sk, bool can_sleep) 277 { 278 __u8 flow_flags = 0; 279 280 if (inet_sk(sk)->transparent) 281 flow_flags |= FLOWI_FLAG_ANYSRC; 282 if (protocol == IPPROTO_TCP) 283 flow_flags |= FLOWI_FLAG_PRECOW_METRICS; 284 if (can_sleep) 285 flow_flags |= FLOWI_FLAG_CAN_SLEEP; 286 287 flowi4_init_output(fl4, oif, sk->sk_mark, tos, RT_SCOPE_UNIVERSE, 288 protocol, flow_flags, dst, src, dport, sport); 289 } 290 291 static inline struct rtable *ip_route_connect(struct flowi4 *fl4, 292 __be32 dst, __be32 src, u32 tos, 293 int oif, u8 protocol, 294 __be16 sport, __be16 dport, 295 struct sock *sk, bool can_sleep) 296 { 297 struct net *net = sock_net(sk); 298 struct rtable *rt; 299 300 ip_route_connect_init(fl4, dst, src, tos, oif, protocol, 301 sport, dport, sk, can_sleep); 302 303 if (!dst || !src) { 304 rt = __ip_route_output_key(net, fl4); 305 if (IS_ERR(rt)) 306 return rt; 307 ip_rt_put(rt); 308 flowi4_update_output(fl4, oif, tos, fl4->daddr, fl4->saddr); 309 } 310 security_sk_classify_flow(sk, flowi4_to_flowi(fl4)); 311 return ip_route_output_flow(net, fl4, sk); 312 } 313 314 static inline struct rtable *ip_route_newports(struct flowi4 *fl4, struct rtable *rt, 315 __be16 orig_sport, __be16 orig_dport, 316 __be16 sport, __be16 dport, 317 struct sock *sk) 318 { 319 if (sport != orig_sport || dport != orig_dport) { 320 fl4->fl4_dport = dport; 321 fl4->fl4_sport = sport; 322 ip_rt_put(rt); 323 flowi4_update_output(fl4, sk->sk_bound_dev_if, 324 RT_CONN_FLAGS(sk), fl4->daddr, 325 fl4->saddr); 326 security_sk_classify_flow(sk, flowi4_to_flowi(fl4)); 327 return ip_route_output_flow(sock_net(sk), fl4, sk); 328 } 329 return rt; 330 } 331 332 extern void rt_bind_peer(struct rtable *rt, __be32 daddr, int create); 333 334 static inline struct inet_peer *__rt_get_peer(struct rtable *rt, __be32 daddr, int create) 335 { 336 if (rt_has_peer(rt)) 337 return rt_peer_ptr(rt); 338 339 rt_bind_peer(rt, daddr, create); 340 return (rt_has_peer(rt) ? rt_peer_ptr(rt) : NULL); 341 } 342 343 static inline struct inet_peer *rt_get_peer(struct rtable *rt, __be32 daddr) 344 { 345 return __rt_get_peer(rt, daddr, 0); 346 } 347 348 static inline struct inet_peer *rt_get_peer_create(struct rtable *rt, __be32 daddr) 349 { 350 return __rt_get_peer(rt, daddr, 1); 351 } 352 353 static inline int inet_iif(const struct sk_buff *skb) 354 { 355 return skb_rtable(skb)->rt_iif; 356 } 357 358 extern int sysctl_ip_default_ttl; 359 360 static inline int ip4_dst_hoplimit(const struct dst_entry *dst) 361 { 362 int hoplimit = dst_metric_raw(dst, RTAX_HOPLIMIT); 363 364 if (hoplimit == 0) 365 hoplimit = sysctl_ip_default_ttl; 366 return hoplimit; 367 } 368 369 #endif /* _ROUTE_H */ 370