route.h revision 55afabaa0df0dd139c8796a71beb43d1216fbe43
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 42struct fib_nh; 43struct inet_peer; 44struct fib_info; 45struct 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 74static inline struct inet_peer *rt_peer_ptr(struct rtable *rt) 75{ 76 return inetpeer_ptr(rt->_peer); 77} 78 79static inline bool rt_has_peer(struct rtable *rt) 80{ 81 return inetpeer_ptr_is_peer(rt->_peer); 82} 83 84static inline void __rt_set_peer(struct rtable *rt, struct inet_peer *peer) 85{ 86 __inetpeer_ptr_set_peer(&rt->_peer, peer); 87} 88 89static inline bool rt_set_peer(struct rtable *rt, struct inet_peer *peer) 90{ 91 return inetpeer_ptr_set_peer(&rt->_peer, peer); 92} 93 94static inline void rt_init_peer(struct rtable *rt, struct inet_peer_base *base) 95{ 96 inetpeer_init_ptr(&rt->_peer, base); 97} 98 99static 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 108static inline bool rt_is_input_route(const struct rtable *rt) 109{ 110 return rt->rt_route_iif != 0; 111} 112 113static inline bool rt_is_output_route(const struct rtable *rt) 114{ 115 return rt->rt_route_iif == 0; 116} 117 118struct ip_rt_acct { 119 __u32 o_bytes; 120 __u32 o_packets; 121 __u32 i_bytes; 122 __u32 i_packets; 123}; 124 125struct 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 144extern struct ip_rt_acct __percpu *ip_rt_acct; 145 146struct in_device; 147extern int ip_rt_init(void); 148extern void ip_rt_redirect(__be32 old_gw, __be32 dst, __be32 new_gw, 149 __be32 src, struct net_device *dev); 150extern void rt_cache_flush(struct net *net, int how); 151extern void rt_cache_flush_batch(struct net *net); 152extern struct rtable *__ip_route_output_key(struct net *, struct flowi4 *flp); 153extern struct rtable *ip_route_output_flow(struct net *, struct flowi4 *flp, 154 struct sock *sk); 155extern struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig); 156 157static 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 162static 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 .daddr = daddr, 168 .saddr = saddr, 169 .flowi4_tos = tos, 170 }; 171 return ip_route_output_key(net, &fl4); 172} 173 174static 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 189static 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 203extern int ip_route_input_common(struct sk_buff *skb, __be32 dst, __be32 src, 204 u8 tos, struct net_device *devin, bool noref); 205 206static 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); 210} 211 212static inline int ip_route_input_noref(struct sk_buff *skb, __be32 dst, __be32 src, 213 u8 tos, struct net_device *devin) 214{ 215 return ip_route_input_common(skb, dst, src, tos, devin, true); 216} 217 218extern void ip_rt_send_redirect(struct sk_buff *skb); 219 220extern unsigned int inet_addr_type(struct net *net, __be32 addr); 221extern unsigned int inet_dev_addr_type(struct net *net, const struct net_device *dev, __be32 addr); 222extern void ip_rt_multicast_event(struct in_device *); 223extern int ip_rt_ioctl(struct net *, unsigned int cmd, void __user *arg); 224extern void ip_rt_get_source(u8 *src, struct sk_buff *skb, struct rtable *rt); 225extern int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb); 226 227struct in_ifaddr; 228extern void fib_add_ifaddr(struct in_ifaddr *); 229extern void fib_del_ifaddr(struct in_ifaddr *, struct in_ifaddr *); 230 231static inline void ip_rt_put(struct rtable * rt) 232{ 233 if (rt) 234 dst_release(&rt->dst); 235} 236 237#define IPTOS_RT_MASK (IPTOS_TOS_MASK & ~3) 238 239extern const __u8 ip_tos2prio[16]; 240 241static inline char rt_tos2priority(u8 tos) 242{ 243 return ip_tos2prio[IPTOS_TOS(tos)>>1]; 244} 245 246/* ip_route_connect() and ip_route_newports() work in tandem whilst 247 * binding a socket for a new outgoing connection. 248 * 249 * In order to use IPSEC properly, we must, in the end, have a 250 * route that was looked up using all available keys including source 251 * and destination ports. 252 * 253 * However, if a source port needs to be allocated (the user specified 254 * a wildcard source port) we need to obtain addressing information 255 * in order to perform that allocation. 256 * 257 * So ip_route_connect() looks up a route using wildcarded source and 258 * destination ports in the key, simply so that we can get a pair of 259 * addresses to use for port allocation. 260 * 261 * Later, once the ports are allocated, ip_route_newports() will make 262 * another route lookup if needed to make sure we catch any IPSEC 263 * rules keyed on the port information. 264 * 265 * The callers allocate the flow key on their stack, and must pass in 266 * the same flowi4 object to both the ip_route_connect() and the 267 * ip_route_newports() calls. 268 */ 269 270static inline void ip_route_connect_init(struct flowi4 *fl4, __be32 dst, __be32 src, 271 u32 tos, int oif, u8 protocol, 272 __be16 sport, __be16 dport, 273 struct sock *sk, bool can_sleep) 274{ 275 __u8 flow_flags = 0; 276 277 if (inet_sk(sk)->transparent) 278 flow_flags |= FLOWI_FLAG_ANYSRC; 279 if (protocol == IPPROTO_TCP) 280 flow_flags |= FLOWI_FLAG_PRECOW_METRICS; 281 if (can_sleep) 282 flow_flags |= FLOWI_FLAG_CAN_SLEEP; 283 284 flowi4_init_output(fl4, oif, sk->sk_mark, tos, RT_SCOPE_UNIVERSE, 285 protocol, flow_flags, dst, src, dport, sport); 286} 287 288static inline struct rtable *ip_route_connect(struct flowi4 *fl4, 289 __be32 dst, __be32 src, u32 tos, 290 int oif, u8 protocol, 291 __be16 sport, __be16 dport, 292 struct sock *sk, bool can_sleep) 293{ 294 struct net *net = sock_net(sk); 295 struct rtable *rt; 296 297 ip_route_connect_init(fl4, dst, src, tos, oif, protocol, 298 sport, dport, sk, can_sleep); 299 300 if (!dst || !src) { 301 rt = __ip_route_output_key(net, fl4); 302 if (IS_ERR(rt)) 303 return rt; 304 ip_rt_put(rt); 305 flowi4_update_output(fl4, oif, tos, fl4->daddr, fl4->saddr); 306 } 307 security_sk_classify_flow(sk, flowi4_to_flowi(fl4)); 308 return ip_route_output_flow(net, fl4, sk); 309} 310 311static inline struct rtable *ip_route_newports(struct flowi4 *fl4, struct rtable *rt, 312 __be16 orig_sport, __be16 orig_dport, 313 __be16 sport, __be16 dport, 314 struct sock *sk) 315{ 316 if (sport != orig_sport || dport != orig_dport) { 317 fl4->fl4_dport = dport; 318 fl4->fl4_sport = sport; 319 ip_rt_put(rt); 320 flowi4_update_output(fl4, sk->sk_bound_dev_if, 321 RT_CONN_FLAGS(sk), fl4->daddr, 322 fl4->saddr); 323 security_sk_classify_flow(sk, flowi4_to_flowi(fl4)); 324 return ip_route_output_flow(sock_net(sk), fl4, sk); 325 } 326 return rt; 327} 328 329extern void rt_bind_peer(struct rtable *rt, __be32 daddr, int create); 330 331static inline struct inet_peer *__rt_get_peer(struct rtable *rt, __be32 daddr, int create) 332{ 333 if (rt_has_peer(rt)) 334 return rt_peer_ptr(rt); 335 336 rt_bind_peer(rt, daddr, create); 337 return (rt_has_peer(rt) ? rt_peer_ptr(rt) : NULL); 338} 339 340static inline struct inet_peer *rt_get_peer(struct rtable *rt, __be32 daddr) 341{ 342 return __rt_get_peer(rt, daddr, 0); 343} 344 345static inline struct inet_peer *rt_get_peer_create(struct rtable *rt, __be32 daddr) 346{ 347 return __rt_get_peer(rt, daddr, 1); 348} 349 350static inline int inet_iif(const struct sk_buff *skb) 351{ 352 return skb_rtable(skb)->rt_iif; 353} 354 355extern int sysctl_ip_default_ttl; 356 357static inline int ip4_dst_hoplimit(const struct dst_entry *dst) 358{ 359 int hoplimit = dst_metric_raw(dst, RTAX_HOPLIMIT); 360 361 if (hoplimit == 0) 362 hoplimit = sysctl_ip_default_ttl; 363 return hoplimit; 364} 365 366#endif /* _ROUTE_H */ 367