route.h revision c6cffba4ffa26a8ffacd0bb9f3144e34f20da7de
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/rcupdate.h> 34#include <linux/route.h> 35#include <linux/ip.h> 36#include <linux/cache.h> 37#include <linux/security.h> 38 39#define RTO_ONLINK 0x01 40 41#define RT_CONN_FLAGS(sk) (RT_TOS(inet_sk(sk)->tos) | sock_flag(sk, SOCK_LOCALROUTE)) 42 43struct fib_nh; 44struct fib_info; 45struct rtable { 46 struct dst_entry dst; 47 48 int rt_genid; 49 unsigned int rt_flags; 50 __u16 rt_type; 51 __u16 rt_is_input; 52 53 int rt_iif; 54 55 /* Info on neighbour */ 56 __be32 rt_gateway; 57 58 /* Miscellaneous cached information */ 59 u32 rt_pmtu; 60}; 61 62static inline bool rt_is_input_route(const struct rtable *rt) 63{ 64 return rt->rt_is_input != 0; 65} 66 67static inline bool rt_is_output_route(const struct rtable *rt) 68{ 69 return rt->rt_is_input == 0; 70} 71 72static inline __be32 rt_nexthop(const struct rtable *rt, __be32 daddr) 73{ 74 if (rt->rt_gateway) 75 return rt->rt_gateway; 76 return daddr; 77} 78 79struct ip_rt_acct { 80 __u32 o_bytes; 81 __u32 o_packets; 82 __u32 i_bytes; 83 __u32 i_packets; 84}; 85 86struct rt_cache_stat { 87 unsigned int in_hit; 88 unsigned int in_slow_tot; 89 unsigned int in_slow_mc; 90 unsigned int in_no_route; 91 unsigned int in_brd; 92 unsigned int in_martian_dst; 93 unsigned int in_martian_src; 94 unsigned int out_hit; 95 unsigned int out_slow_tot; 96 unsigned int out_slow_mc; 97 unsigned int gc_total; 98 unsigned int gc_ignored; 99 unsigned int gc_goal_miss; 100 unsigned int gc_dst_overflow; 101 unsigned int in_hlist_search; 102 unsigned int out_hlist_search; 103}; 104 105extern struct ip_rt_acct __percpu *ip_rt_acct; 106 107struct in_device; 108extern int ip_rt_init(void); 109extern void rt_cache_flush(struct net *net, int how); 110extern struct rtable *__ip_route_output_key(struct net *, struct flowi4 *flp); 111extern struct rtable *ip_route_output_flow(struct net *, struct flowi4 *flp, 112 struct sock *sk); 113extern struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig); 114 115static inline struct rtable *ip_route_output_key(struct net *net, struct flowi4 *flp) 116{ 117 return ip_route_output_flow(net, flp, NULL); 118} 119 120static inline struct rtable *ip_route_output(struct net *net, __be32 daddr, 121 __be32 saddr, u8 tos, int oif) 122{ 123 struct flowi4 fl4 = { 124 .flowi4_oif = oif, 125 .flowi4_tos = tos, 126 .daddr = daddr, 127 .saddr = saddr, 128 }; 129 return ip_route_output_key(net, &fl4); 130} 131 132static inline struct rtable *ip_route_output_ports(struct net *net, struct flowi4 *fl4, 133 struct sock *sk, 134 __be32 daddr, __be32 saddr, 135 __be16 dport, __be16 sport, 136 __u8 proto, __u8 tos, int oif) 137{ 138 flowi4_init_output(fl4, oif, sk ? sk->sk_mark : 0, tos, 139 RT_SCOPE_UNIVERSE, proto, 140 sk ? inet_sk_flowi_flags(sk) : 0, 141 daddr, saddr, dport, sport); 142 if (sk) 143 security_sk_classify_flow(sk, flowi4_to_flowi(fl4)); 144 return ip_route_output_flow(net, fl4, sk); 145} 146 147static inline struct rtable *ip_route_output_gre(struct net *net, struct flowi4 *fl4, 148 __be32 daddr, __be32 saddr, 149 __be32 gre_key, __u8 tos, int oif) 150{ 151 memset(fl4, 0, sizeof(*fl4)); 152 fl4->flowi4_oif = oif; 153 fl4->daddr = daddr; 154 fl4->saddr = saddr; 155 fl4->flowi4_tos = tos; 156 fl4->flowi4_proto = IPPROTO_GRE; 157 fl4->fl4_gre_key = gre_key; 158 return ip_route_output_key(net, fl4); 159} 160 161extern int ip_route_input_noref(struct sk_buff *skb, __be32 dst, __be32 src, 162 u8 tos, struct net_device *devin); 163 164static inline int ip_route_input(struct sk_buff *skb, __be32 dst, __be32 src, 165 u8 tos, struct net_device *devin) 166{ 167 int err; 168 169 rcu_read_lock(); 170 err = ip_route_input_noref(skb, dst, src, tos, devin); 171 if (!err) 172 skb_dst_force(skb); 173 rcu_read_unlock(); 174 175 return err; 176} 177 178extern void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu, 179 int oif, u32 mark, u8 protocol, int flow_flags); 180extern void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu); 181extern void ipv4_redirect(struct sk_buff *skb, struct net *net, 182 int oif, u32 mark, u8 protocol, int flow_flags); 183extern void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk); 184extern void ip_rt_send_redirect(struct sk_buff *skb); 185 186extern unsigned int inet_addr_type(struct net *net, __be32 addr); 187extern unsigned int inet_dev_addr_type(struct net *net, const struct net_device *dev, __be32 addr); 188extern void ip_rt_multicast_event(struct in_device *); 189extern int ip_rt_ioctl(struct net *, unsigned int cmd, void __user *arg); 190extern void ip_rt_get_source(u8 *src, struct sk_buff *skb, struct rtable *rt); 191extern int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb); 192 193struct in_ifaddr; 194extern void fib_add_ifaddr(struct in_ifaddr *); 195extern void fib_del_ifaddr(struct in_ifaddr *, struct in_ifaddr *); 196 197static inline void ip_rt_put(struct rtable * rt) 198{ 199 if (rt) 200 dst_release(&rt->dst); 201} 202 203#define IPTOS_RT_MASK (IPTOS_TOS_MASK & ~3) 204 205extern const __u8 ip_tos2prio[16]; 206 207static inline char rt_tos2priority(u8 tos) 208{ 209 return ip_tos2prio[IPTOS_TOS(tos)>>1]; 210} 211 212/* ip_route_connect() and ip_route_newports() work in tandem whilst 213 * binding a socket for a new outgoing connection. 214 * 215 * In order to use IPSEC properly, we must, in the end, have a 216 * route that was looked up using all available keys including source 217 * and destination ports. 218 * 219 * However, if a source port needs to be allocated (the user specified 220 * a wildcard source port) we need to obtain addressing information 221 * in order to perform that allocation. 222 * 223 * So ip_route_connect() looks up a route using wildcarded source and 224 * destination ports in the key, simply so that we can get a pair of 225 * addresses to use for port allocation. 226 * 227 * Later, once the ports are allocated, ip_route_newports() will make 228 * another route lookup if needed to make sure we catch any IPSEC 229 * rules keyed on the port information. 230 * 231 * The callers allocate the flow key on their stack, and must pass in 232 * the same flowi4 object to both the ip_route_connect() and the 233 * ip_route_newports() calls. 234 */ 235 236static inline void ip_route_connect_init(struct flowi4 *fl4, __be32 dst, __be32 src, 237 u32 tos, int oif, u8 protocol, 238 __be16 sport, __be16 dport, 239 struct sock *sk, bool can_sleep) 240{ 241 __u8 flow_flags = 0; 242 243 if (inet_sk(sk)->transparent) 244 flow_flags |= FLOWI_FLAG_ANYSRC; 245 if (can_sleep) 246 flow_flags |= FLOWI_FLAG_CAN_SLEEP; 247 248 flowi4_init_output(fl4, oif, sk->sk_mark, tos, RT_SCOPE_UNIVERSE, 249 protocol, flow_flags, dst, src, dport, sport); 250} 251 252static inline struct rtable *ip_route_connect(struct flowi4 *fl4, 253 __be32 dst, __be32 src, u32 tos, 254 int oif, u8 protocol, 255 __be16 sport, __be16 dport, 256 struct sock *sk, bool can_sleep) 257{ 258 struct net *net = sock_net(sk); 259 struct rtable *rt; 260 261 ip_route_connect_init(fl4, dst, src, tos, oif, protocol, 262 sport, dport, sk, can_sleep); 263 264 if (!dst || !src) { 265 rt = __ip_route_output_key(net, fl4); 266 if (IS_ERR(rt)) 267 return rt; 268 ip_rt_put(rt); 269 flowi4_update_output(fl4, oif, tos, fl4->daddr, fl4->saddr); 270 } 271 security_sk_classify_flow(sk, flowi4_to_flowi(fl4)); 272 return ip_route_output_flow(net, fl4, sk); 273} 274 275static inline struct rtable *ip_route_newports(struct flowi4 *fl4, struct rtable *rt, 276 __be16 orig_sport, __be16 orig_dport, 277 __be16 sport, __be16 dport, 278 struct sock *sk) 279{ 280 if (sport != orig_sport || dport != orig_dport) { 281 fl4->fl4_dport = dport; 282 fl4->fl4_sport = sport; 283 ip_rt_put(rt); 284 flowi4_update_output(fl4, sk->sk_bound_dev_if, 285 RT_CONN_FLAGS(sk), fl4->daddr, 286 fl4->saddr); 287 security_sk_classify_flow(sk, flowi4_to_flowi(fl4)); 288 return ip_route_output_flow(sock_net(sk), fl4, sk); 289 } 290 return rt; 291} 292 293static inline int inet_iif(const struct sk_buff *skb) 294{ 295 int iif = skb_rtable(skb)->rt_iif; 296 297 if (iif) 298 return iif; 299 return skb->skb_iif; 300} 301 302extern int sysctl_ip_default_ttl; 303 304static inline int ip4_dst_hoplimit(const struct dst_entry *dst) 305{ 306 int hoplimit = dst_metric_raw(dst, RTAX_HOPLIMIT); 307 308 if (hoplimit == 0) 309 hoplimit = sysctl_ip_default_ttl; 310 return hoplimit; 311} 312 313#endif /* _ROUTE_H */ 314