route.h revision 1f42539d257af671d56d4bdbcf13aef31abff6ef
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 fib_info; 44struct rtable { 45 struct dst_entry dst; 46 47 /* Lookup key. */ 48 __be32 rt_key_dst; 49 __be32 rt_key_src; 50 51 int rt_genid; 52 unsigned int rt_flags; 53 __u16 rt_type; 54 __u8 rt_key_tos; 55 56 __be32 rt_dst; /* Path destination */ 57 __be32 rt_src; /* Path source */ 58 int rt_route_iif; 59 int rt_iif; 60 int rt_oif; 61 __u32 rt_mark; 62 63 /* Info on neighbour */ 64 __be32 rt_gateway; 65 66 /* Miscellaneous cached information */ 67 u32 rt_pmtu; 68 struct fib_info *fi; /* for client ref to shared metrics */ 69}; 70 71static inline bool rt_is_input_route(const struct rtable *rt) 72{ 73 return rt->rt_route_iif != 0; 74} 75 76static inline bool rt_is_output_route(const struct rtable *rt) 77{ 78 return rt->rt_route_iif == 0; 79} 80 81struct ip_rt_acct { 82 __u32 o_bytes; 83 __u32 o_packets; 84 __u32 i_bytes; 85 __u32 i_packets; 86}; 87 88struct rt_cache_stat { 89 unsigned int in_hit; 90 unsigned int in_slow_tot; 91 unsigned int in_slow_mc; 92 unsigned int in_no_route; 93 unsigned int in_brd; 94 unsigned int in_martian_dst; 95 unsigned int in_martian_src; 96 unsigned int out_hit; 97 unsigned int out_slow_tot; 98 unsigned int out_slow_mc; 99 unsigned int gc_total; 100 unsigned int gc_ignored; 101 unsigned int gc_goal_miss; 102 unsigned int gc_dst_overflow; 103 unsigned int in_hlist_search; 104 unsigned int out_hlist_search; 105}; 106 107extern struct ip_rt_acct __percpu *ip_rt_acct; 108 109struct in_device; 110extern int ip_rt_init(void); 111extern void rt_cache_flush(struct net *net, int how); 112extern void rt_cache_flush_batch(struct net *net); 113extern struct rtable *__ip_route_output_key(struct net *, struct flowi4 *flp); 114extern struct rtable *ip_route_output_flow(struct net *, struct flowi4 *flp, 115 struct sock *sk); 116extern struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig); 117 118static inline struct rtable *ip_route_output_key(struct net *net, struct flowi4 *flp) 119{ 120 return ip_route_output_flow(net, flp, NULL); 121} 122 123static inline struct rtable *ip_route_output(struct net *net, __be32 daddr, 124 __be32 saddr, u8 tos, int oif) 125{ 126 struct flowi4 fl4 = { 127 .flowi4_oif = oif, 128 .flowi4_tos = tos, 129 .daddr = daddr, 130 .saddr = saddr, 131 }; 132 return ip_route_output_key(net, &fl4); 133} 134 135static inline struct rtable *ip_route_output_ports(struct net *net, struct flowi4 *fl4, 136 struct sock *sk, 137 __be32 daddr, __be32 saddr, 138 __be16 dport, __be16 sport, 139 __u8 proto, __u8 tos, int oif) 140{ 141 flowi4_init_output(fl4, oif, sk ? sk->sk_mark : 0, tos, 142 RT_SCOPE_UNIVERSE, proto, 143 sk ? inet_sk_flowi_flags(sk) : 0, 144 daddr, saddr, dport, sport); 145 if (sk) 146 security_sk_classify_flow(sk, flowi4_to_flowi(fl4)); 147 return ip_route_output_flow(net, fl4, sk); 148} 149 150static inline struct rtable *ip_route_output_gre(struct net *net, struct flowi4 *fl4, 151 __be32 daddr, __be32 saddr, 152 __be32 gre_key, __u8 tos, int oif) 153{ 154 memset(fl4, 0, sizeof(*fl4)); 155 fl4->flowi4_oif = oif; 156 fl4->daddr = daddr; 157 fl4->saddr = saddr; 158 fl4->flowi4_tos = tos; 159 fl4->flowi4_proto = IPPROTO_GRE; 160 fl4->fl4_gre_key = gre_key; 161 return ip_route_output_key(net, fl4); 162} 163 164extern int ip_route_input_common(struct sk_buff *skb, __be32 dst, __be32 src, 165 u8 tos, struct net_device *devin, bool noref); 166 167static inline int ip_route_input(struct sk_buff *skb, __be32 dst, __be32 src, 168 u8 tos, struct net_device *devin) 169{ 170 return ip_route_input_common(skb, dst, src, tos, devin, false); 171} 172 173static inline int ip_route_input_noref(struct sk_buff *skb, __be32 dst, __be32 src, 174 u8 tos, struct net_device *devin) 175{ 176 return ip_route_input_common(skb, dst, src, tos, devin, true); 177} 178 179extern void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu, 180 int oif, u32 mark, u8 protocol, int flow_flags); 181extern void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu); 182extern void ipv4_redirect(struct sk_buff *skb, struct net *net, 183 int oif, u32 mark, u8 protocol, int flow_flags); 184extern void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk); 185extern void ip_rt_send_redirect(struct sk_buff *skb); 186 187extern unsigned int inet_addr_type(struct net *net, __be32 addr); 188extern unsigned int inet_dev_addr_type(struct net *net, const struct net_device *dev, __be32 addr); 189extern void ip_rt_multicast_event(struct in_device *); 190extern int ip_rt_ioctl(struct net *, unsigned int cmd, void __user *arg); 191extern void ip_rt_get_source(u8 *src, struct sk_buff *skb, struct rtable *rt); 192extern int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb); 193 194struct in_ifaddr; 195extern void fib_add_ifaddr(struct in_ifaddr *); 196extern void fib_del_ifaddr(struct in_ifaddr *, struct in_ifaddr *); 197 198static inline void ip_rt_put(struct rtable * rt) 199{ 200 if (rt) 201 dst_release(&rt->dst); 202} 203 204#define IPTOS_RT_MASK (IPTOS_TOS_MASK & ~3) 205 206extern const __u8 ip_tos2prio[16]; 207 208static inline char rt_tos2priority(u8 tos) 209{ 210 return ip_tos2prio[IPTOS_TOS(tos)>>1]; 211} 212 213/* ip_route_connect() and ip_route_newports() work in tandem whilst 214 * binding a socket for a new outgoing connection. 215 * 216 * In order to use IPSEC properly, we must, in the end, have a 217 * route that was looked up using all available keys including source 218 * and destination ports. 219 * 220 * However, if a source port needs to be allocated (the user specified 221 * a wildcard source port) we need to obtain addressing information 222 * in order to perform that allocation. 223 * 224 * So ip_route_connect() looks up a route using wildcarded source and 225 * destination ports in the key, simply so that we can get a pair of 226 * addresses to use for port allocation. 227 * 228 * Later, once the ports are allocated, ip_route_newports() will make 229 * another route lookup if needed to make sure we catch any IPSEC 230 * rules keyed on the port information. 231 * 232 * The callers allocate the flow key on their stack, and must pass in 233 * the same flowi4 object to both the ip_route_connect() and the 234 * ip_route_newports() calls. 235 */ 236 237static inline void ip_route_connect_init(struct flowi4 *fl4, __be32 dst, __be32 src, 238 u32 tos, int oif, u8 protocol, 239 __be16 sport, __be16 dport, 240 struct sock *sk, bool can_sleep) 241{ 242 __u8 flow_flags = 0; 243 244 if (inet_sk(sk)->transparent) 245 flow_flags |= FLOWI_FLAG_ANYSRC; 246 if (can_sleep) 247 flow_flags |= FLOWI_FLAG_CAN_SLEEP; 248 249 flowi4_init_output(fl4, oif, sk->sk_mark, tos, RT_SCOPE_UNIVERSE, 250 protocol, flow_flags, dst, src, dport, sport); 251} 252 253static inline struct rtable *ip_route_connect(struct flowi4 *fl4, 254 __be32 dst, __be32 src, u32 tos, 255 int oif, u8 protocol, 256 __be16 sport, __be16 dport, 257 struct sock *sk, bool can_sleep) 258{ 259 struct net *net = sock_net(sk); 260 struct rtable *rt; 261 262 ip_route_connect_init(fl4, dst, src, tos, oif, protocol, 263 sport, dport, sk, can_sleep); 264 265 if (!dst || !src) { 266 rt = __ip_route_output_key(net, fl4); 267 if (IS_ERR(rt)) 268 return rt; 269 ip_rt_put(rt); 270 flowi4_update_output(fl4, oif, tos, fl4->daddr, fl4->saddr); 271 } 272 security_sk_classify_flow(sk, flowi4_to_flowi(fl4)); 273 return ip_route_output_flow(net, fl4, sk); 274} 275 276static inline struct rtable *ip_route_newports(struct flowi4 *fl4, struct rtable *rt, 277 __be16 orig_sport, __be16 orig_dport, 278 __be16 sport, __be16 dport, 279 struct sock *sk) 280{ 281 if (sport != orig_sport || dport != orig_dport) { 282 fl4->fl4_dport = dport; 283 fl4->fl4_sport = sport; 284 ip_rt_put(rt); 285 flowi4_update_output(fl4, sk->sk_bound_dev_if, 286 RT_CONN_FLAGS(sk), fl4->daddr, 287 fl4->saddr); 288 security_sk_classify_flow(sk, flowi4_to_flowi(fl4)); 289 return ip_route_output_flow(sock_net(sk), fl4, sk); 290 } 291 return rt; 292} 293 294static inline int inet_iif(const struct sk_buff *skb) 295{ 296 return skb_rtable(skb)->rt_iif; 297} 298 299extern int sysctl_ip_default_ttl; 300 301static inline int ip4_dst_hoplimit(const struct dst_entry *dst) 302{ 303 int hoplimit = dst_metric_raw(dst, RTAX_HOPLIMIT); 304 305 if (hoplimit == 0) 306 hoplimit = sysctl_ip_default_ttl; 307 return hoplimit; 308} 309 310#endif /* _ROUTE_H */ 311