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 #ifndef __KERNEL__ 39 #warning This file is not supposed to be used outside of kernel. 40 #endif 41 42 #define RTO_ONLINK 0x01 43 44 #define RTO_CONN 0 45 /* RTO_CONN is not used (being alias for 0), but preserved not to break 46 * some modules referring to it. */ 47 48 #define RT_CONN_FLAGS(sk) (RT_TOS(inet_sk(sk)->tos) | sock_flag(sk, SOCK_LOCALROUTE)) 49 50 struct fib_nh; 51 struct inet_peer; 52 struct fib_info; 53 struct rtable { 54 struct dst_entry dst; 55 56 /* Lookup key. */ 57 __be32 rt_key_dst; 58 __be32 rt_key_src; 59 60 int rt_genid; 61 unsigned rt_flags; 62 __u16 rt_type; 63 __u8 rt_tos; 64 65 __be32 rt_dst; /* Path destination */ 66 __be32 rt_src; /* Path source */ 67 int rt_route_iif; 68 int rt_iif; 69 int rt_oif; 70 __u32 rt_mark; 71 72 /* Info on neighbour */ 73 __be32 rt_gateway; 74 75 /* Miscellaneous cached information */ 76 __be32 rt_spec_dst; /* RFC1122 specific destination */ 77 u32 rt_peer_genid; 78 struct inet_peer *peer; /* long-living peer info */ 79 struct fib_info *fi; /* for client ref to shared metrics */ 80 }; 81 82 static inline bool rt_is_input_route(struct rtable *rt) 83 { 84 return rt->rt_route_iif != 0; 85 } 86 87 static inline bool rt_is_output_route(struct rtable *rt) 88 { 89 return rt->rt_route_iif == 0; 90 } 91 92 struct ip_rt_acct { 93 __u32 o_bytes; 94 __u32 o_packets; 95 __u32 i_bytes; 96 __u32 i_packets; 97 }; 98 99 struct rt_cache_stat { 100 unsigned int in_hit; 101 unsigned int in_slow_tot; 102 unsigned int in_slow_mc; 103 unsigned int in_no_route; 104 unsigned int in_brd; 105 unsigned int in_martian_dst; 106 unsigned int in_martian_src; 107 unsigned int out_hit; 108 unsigned int out_slow_tot; 109 unsigned int out_slow_mc; 110 unsigned int gc_total; 111 unsigned int gc_ignored; 112 unsigned int gc_goal_miss; 113 unsigned int gc_dst_overflow; 114 unsigned int in_hlist_search; 115 unsigned int out_hlist_search; 116 }; 117 118 extern struct ip_rt_acct __percpu *ip_rt_acct; 119 120 struct in_device; 121 extern int ip_rt_init(void); 122 extern void ip_rt_redirect(__be32 old_gw, __be32 dst, __be32 new_gw, 123 __be32 src, struct net_device *dev); 124 extern void rt_cache_flush(struct net *net, int how); 125 extern void rt_cache_flush_batch(struct net *net); 126 extern struct rtable *__ip_route_output_key(struct net *, const struct flowi4 *flp); 127 extern struct rtable *ip_route_output_flow(struct net *, struct flowi4 *flp, 128 struct sock *sk); 129 extern struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig); 130 131 static inline struct rtable *ip_route_output_key(struct net *net, struct flowi4 *flp) 132 { 133 return ip_route_output_flow(net, flp, NULL); 134 } 135 136 static inline struct rtable *ip_route_output(struct net *net, __be32 daddr, 137 __be32 saddr, u8 tos, int oif) 138 { 139 struct flowi4 fl4 = { 140 .flowi4_oif = oif, 141 .daddr = daddr, 142 .saddr = saddr, 143 .flowi4_tos = tos, 144 }; 145 return ip_route_output_key(net, &fl4); 146 } 147 148 static inline struct rtable *ip_route_output_ports(struct net *net, struct sock *sk, 149 __be32 daddr, __be32 saddr, 150 __be16 dport, __be16 sport, 151 __u8 proto, __u8 tos, int oif) 152 { 153 struct flowi4 fl4; 154 155 flowi4_init_output(&fl4, oif, sk ? sk->sk_mark : 0, tos, 156 RT_SCOPE_UNIVERSE, proto, 157 sk ? inet_sk_flowi_flags(sk) : 0, 158 daddr, saddr, dport, sport); 159 if (sk) 160 security_sk_classify_flow(sk, flowi4_to_flowi(&fl4)); 161 return ip_route_output_flow(net, &fl4, sk); 162 } 163 164 static inline struct rtable *ip_route_output_gre(struct net *net, 165 __be32 daddr, __be32 saddr, 166 __be32 gre_key, __u8 tos, int oif) 167 { 168 struct flowi4 fl4 = { 169 .flowi4_oif = oif, 170 .daddr = daddr, 171 .saddr = saddr, 172 .flowi4_tos = tos, 173 .flowi4_proto = IPPROTO_GRE, 174 .fl4_gre_key = gre_key, 175 }; 176 return ip_route_output_key(net, &fl4); 177 } 178 179 extern int ip_route_input_common(struct sk_buff *skb, __be32 dst, __be32 src, 180 u8 tos, struct net_device *devin, bool noref); 181 182 static inline int ip_route_input(struct sk_buff *skb, __be32 dst, __be32 src, 183 u8 tos, struct net_device *devin) 184 { 185 return ip_route_input_common(skb, dst, src, tos, devin, false); 186 } 187 188 static inline int ip_route_input_noref(struct sk_buff *skb, __be32 dst, __be32 src, 189 u8 tos, struct net_device *devin) 190 { 191 return ip_route_input_common(skb, dst, src, tos, devin, true); 192 } 193 194 extern unsigned short ip_rt_frag_needed(struct net *net, const struct iphdr *iph, 195 unsigned short new_mtu, struct net_device *dev); 196 extern void ip_rt_send_redirect(struct sk_buff *skb); 197 198 extern unsigned inet_addr_type(struct net *net, __be32 addr); 199 extern unsigned inet_dev_addr_type(struct net *net, const struct net_device *dev, __be32 addr); 200 extern void ip_rt_multicast_event(struct in_device *); 201 extern int ip_rt_ioctl(struct net *, unsigned int cmd, void __user *arg); 202 extern void ip_rt_get_source(u8 *src, struct rtable *rt); 203 extern int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb); 204 205 struct in_ifaddr; 206 extern void fib_add_ifaddr(struct in_ifaddr *); 207 extern void fib_del_ifaddr(struct in_ifaddr *, struct in_ifaddr *); 208 209 static inline void ip_rt_put(struct rtable * rt) 210 { 211 if (rt) 212 dst_release(&rt->dst); 213 } 214 215 #define IPTOS_RT_MASK (IPTOS_TOS_MASK & ~3) 216 217 extern const __u8 ip_tos2prio[16]; 218 219 static inline char rt_tos2priority(u8 tos) 220 { 221 return ip_tos2prio[IPTOS_TOS(tos)>>1]; 222 } 223 224 static inline struct rtable *ip_route_connect(__be32 dst, __be32 src, u32 tos, 225 int oif, u8 protocol, 226 __be16 sport, __be16 dport, 227 struct sock *sk, bool can_sleep) 228 { 229 struct net *net = sock_net(sk); 230 struct rtable *rt; 231 struct flowi4 fl4; 232 __u8 flow_flags; 233 234 flow_flags = 0; 235 if (inet_sk(sk)->transparent) 236 flow_flags |= FLOWI_FLAG_ANYSRC; 237 if (protocol == IPPROTO_TCP) 238 flow_flags |= FLOWI_FLAG_PRECOW_METRICS; 239 if (can_sleep) 240 flow_flags |= FLOWI_FLAG_CAN_SLEEP; 241 242 flowi4_init_output(&fl4, oif, sk->sk_mark, tos, RT_SCOPE_UNIVERSE, 243 protocol, flow_flags, dst, src, dport, sport); 244 245 if (!dst || !src) { 246 rt = __ip_route_output_key(net, &fl4); 247 if (IS_ERR(rt)) 248 return rt; 249 fl4.daddr = rt->rt_dst; 250 fl4.saddr = rt->rt_src; 251 ip_rt_put(rt); 252 } 253 security_sk_classify_flow(sk, flowi4_to_flowi(&fl4)); 254 return ip_route_output_flow(net, &fl4, sk); 255 } 256 257 static inline struct rtable *ip_route_newports(struct rtable *rt, 258 u8 protocol, __be16 orig_sport, 259 __be16 orig_dport, __be16 sport, 260 __be16 dport, struct sock *sk) 261 { 262 if (sport != orig_sport || dport != orig_dport) { 263 struct flowi4 fl4; 264 __u8 flow_flags; 265 266 flow_flags = 0; 267 if (inet_sk(sk)->transparent) 268 flow_flags |= FLOWI_FLAG_ANYSRC; 269 if (protocol == IPPROTO_TCP) 270 flow_flags |= FLOWI_FLAG_PRECOW_METRICS; 271 flowi4_init_output(&fl4, rt->rt_oif, rt->rt_mark, rt->rt_tos, 272 RT_SCOPE_UNIVERSE, protocol, flow_flags, 273 rt->rt_dst, rt->rt_src, dport, sport); 274 ip_rt_put(rt); 275 security_sk_classify_flow(sk, flowi4_to_flowi(&fl4)); 276 return ip_route_output_flow(sock_net(sk), &fl4, sk); 277 } 278 return rt; 279 } 280 281 extern void rt_bind_peer(struct rtable *rt, int create); 282 283 static inline struct inet_peer *rt_get_peer(struct rtable *rt) 284 { 285 if (rt->peer) 286 return rt->peer; 287 288 rt_bind_peer(rt, 0); 289 return rt->peer; 290 } 291 292 static inline int inet_iif(const struct sk_buff *skb) 293 { 294 return skb_rtable(skb)->rt_iif; 295 } 296 297 extern int sysctl_ip_default_ttl; 298 299 static inline int ip4_dst_hoplimit(const struct dst_entry *dst) 300 { 301 int hoplimit = dst_metric_raw(dst, RTAX_HOPLIMIT); 302 303 if (hoplimit == 0) 304 hoplimit = sysctl_ip_default_ttl; 305 return hoplimit; 306 } 307 308 #endif /* _ROUTE_H */ 309