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 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 struct inet_peer *peer; /* long-living peer info */ 71 struct fib_info *fi; /* for client ref to shared metrics */ 72 }; 73 74 static inline bool rt_is_input_route(struct rtable *rt) 75 { 76 return rt->rt_route_iif != 0; 77 } 78 79 static inline bool rt_is_output_route(struct rtable *rt) 80 { 81 return rt->rt_route_iif == 0; 82 } 83 84 struct ip_rt_acct { 85 __u32 o_bytes; 86 __u32 o_packets; 87 __u32 i_bytes; 88 __u32 i_packets; 89 }; 90 91 struct rt_cache_stat { 92 unsigned int in_hit; 93 unsigned int in_slow_tot; 94 unsigned int in_slow_mc; 95 unsigned int in_no_route; 96 unsigned int in_brd; 97 unsigned int in_martian_dst; 98 unsigned int in_martian_src; 99 unsigned int out_hit; 100 unsigned int out_slow_tot; 101 unsigned int out_slow_mc; 102 unsigned int gc_total; 103 unsigned int gc_ignored; 104 unsigned int gc_goal_miss; 105 unsigned int gc_dst_overflow; 106 unsigned int in_hlist_search; 107 unsigned int out_hlist_search; 108 }; 109 110 extern struct ip_rt_acct __percpu *ip_rt_acct; 111 112 struct in_device; 113 extern int ip_rt_init(void); 114 extern void ip_rt_redirect(__be32 old_gw, __be32 dst, __be32 new_gw, 115 __be32 src, struct net_device *dev); 116 extern void rt_cache_flush(struct net *net, int how); 117 extern void rt_cache_flush_batch(struct net *net); 118 extern struct rtable *__ip_route_output_key(struct net *, struct flowi4 *flp); 119 extern struct rtable *ip_route_output_flow(struct net *, struct flowi4 *flp, 120 struct sock *sk); 121 extern struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig); 122 123 static inline struct rtable *ip_route_output_key(struct net *net, struct flowi4 *flp) 124 { 125 return ip_route_output_flow(net, flp, NULL); 126 } 127 128 static inline struct rtable *ip_route_output(struct net *net, __be32 daddr, 129 __be32 saddr, u8 tos, int oif) 130 { 131 struct flowi4 fl4 = { 132 .flowi4_oif = oif, 133 .daddr = daddr, 134 .saddr = saddr, 135 .flowi4_tos = tos, 136 }; 137 return ip_route_output_key(net, &fl4); 138 } 139 140 static inline struct rtable *ip_route_output_ports(struct net *net, struct flowi4 *fl4, 141 struct sock *sk, 142 __be32 daddr, __be32 saddr, 143 __be16 dport, __be16 sport, 144 __u8 proto, __u8 tos, int oif) 145 { 146 flowi4_init_output(fl4, oif, sk ? sk->sk_mark : 0, tos, 147 RT_SCOPE_UNIVERSE, proto, 148 sk ? inet_sk_flowi_flags(sk) : 0, 149 daddr, saddr, dport, sport); 150 if (sk) 151 security_sk_classify_flow(sk, flowi4_to_flowi(fl4)); 152 return ip_route_output_flow(net, fl4, sk); 153 } 154 155 static inline struct rtable *ip_route_output_gre(struct net *net, struct flowi4 *fl4, 156 __be32 daddr, __be32 saddr, 157 __be32 gre_key, __u8 tos, int oif) 158 { 159 memset(fl4, 0, sizeof(*fl4)); 160 fl4->flowi4_oif = oif; 161 fl4->daddr = daddr; 162 fl4->saddr = saddr; 163 fl4->flowi4_tos = tos; 164 fl4->flowi4_proto = IPPROTO_GRE; 165 fl4->fl4_gre_key = gre_key; 166 return ip_route_output_key(net, fl4); 167 } 168 169 extern int ip_route_input_common(struct sk_buff *skb, __be32 dst, __be32 src, 170 u8 tos, struct net_device *devin, bool noref); 171 172 static inline int ip_route_input(struct sk_buff *skb, __be32 dst, __be32 src, 173 u8 tos, struct net_device *devin) 174 { 175 return ip_route_input_common(skb, dst, src, tos, devin, false); 176 } 177 178 static inline int ip_route_input_noref(struct sk_buff *skb, __be32 dst, __be32 src, 179 u8 tos, struct net_device *devin) 180 { 181 return ip_route_input_common(skb, dst, src, tos, devin, true); 182 } 183 184 extern unsigned short ip_rt_frag_needed(struct net *net, const struct iphdr *iph, 185 unsigned short new_mtu, struct net_device *dev); 186 extern void ip_rt_send_redirect(struct sk_buff *skb); 187 188 extern unsigned inet_addr_type(struct net *net, __be32 addr); 189 extern unsigned inet_dev_addr_type(struct net *net, const struct net_device *dev, __be32 addr); 190 extern void ip_rt_multicast_event(struct in_device *); 191 extern int ip_rt_ioctl(struct net *, unsigned int cmd, void __user *arg); 192 extern void ip_rt_get_source(u8 *src, struct rtable *rt); 193 extern int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb); 194 195 struct in_ifaddr; 196 extern void fib_add_ifaddr(struct in_ifaddr *); 197 extern void fib_del_ifaddr(struct in_ifaddr *, struct in_ifaddr *); 198 199 static inline void ip_rt_put(struct rtable * rt) 200 { 201 if (rt) 202 dst_release(&rt->dst); 203 } 204 205 #define IPTOS_RT_MASK (IPTOS_TOS_MASK & ~3) 206 207 extern const __u8 ip_tos2prio[16]; 208 209 static inline char rt_tos2priority(u8 tos) 210 { 211 return ip_tos2prio[IPTOS_TOS(tos)>>1]; 212 } 213 214 /* ip_route_connect() and ip_route_newports() work in tandem whilst 215 * binding a socket for a new outgoing connection. 216 * 217 * In order to use IPSEC properly, we must, in the end, have a 218 * route that was looked up using all available keys including source 219 * and destination ports. 220 * 221 * However, if a source port needs to be allocated (the user specified 222 * a wildcard source port) we need to obtain addressing information 223 * in order to perform that allocation. 224 * 225 * So ip_route_connect() looks up a route using wildcarded source and 226 * destination ports in the key, simply so that we can get a pair of 227 * addresses to use for port allocation. 228 * 229 * Later, once the ports are allocated, ip_route_newports() will make 230 * another route lookup if needed to make sure we catch any IPSEC 231 * rules keyed on the port information. 232 * 233 * The callers allocate the flow key on their stack, and must pass in 234 * the same flowi4 object to both the ip_route_connect() and the 235 * ip_route_newports() calls. 236 */ 237 238 static inline void ip_route_connect_init(struct flowi4 *fl4, __be32 dst, __be32 src, 239 u32 tos, int oif, u8 protocol, 240 __be16 sport, __be16 dport, 241 struct sock *sk, bool can_sleep) 242 { 243 __u8 flow_flags = 0; 244 245 if (inet_sk(sk)->transparent) 246 flow_flags |= FLOWI_FLAG_ANYSRC; 247 if (protocol == IPPROTO_TCP) 248 flow_flags |= FLOWI_FLAG_PRECOW_METRICS; 249 if (can_sleep) 250 flow_flags |= FLOWI_FLAG_CAN_SLEEP; 251 252 flowi4_init_output(fl4, oif, sk->sk_mark, tos, RT_SCOPE_UNIVERSE, 253 protocol, flow_flags, dst, src, dport, sport); 254 } 255 256 static inline struct rtable *ip_route_connect(struct flowi4 *fl4, 257 __be32 dst, __be32 src, u32 tos, 258 int oif, u8 protocol, 259 __be16 sport, __be16 dport, 260 struct sock *sk, bool can_sleep) 261 { 262 struct net *net = sock_net(sk); 263 struct rtable *rt; 264 265 ip_route_connect_init(fl4, dst, src, tos, oif, protocol, 266 sport, dport, sk, can_sleep); 267 268 if (!dst || !src) { 269 rt = __ip_route_output_key(net, fl4); 270 if (IS_ERR(rt)) 271 return rt; 272 ip_rt_put(rt); 273 } 274 security_sk_classify_flow(sk, flowi4_to_flowi(fl4)); 275 return ip_route_output_flow(net, fl4, sk); 276 } 277 278 static inline struct rtable *ip_route_newports(struct flowi4 *fl4, struct rtable *rt, 279 __be16 orig_sport, __be16 orig_dport, 280 __be16 sport, __be16 dport, 281 struct sock *sk) 282 { 283 if (sport != orig_sport || dport != orig_dport) { 284 fl4->fl4_dport = dport; 285 fl4->fl4_sport = sport; 286 ip_rt_put(rt); 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 } 292 293 extern void rt_bind_peer(struct rtable *rt, int create); 294 295 static inline struct inet_peer *rt_get_peer(struct rtable *rt) 296 { 297 if (rt->peer) 298 return rt->peer; 299 300 rt_bind_peer(rt, 0); 301 return rt->peer; 302 } 303 304 static inline int inet_iif(const struct sk_buff *skb) 305 { 306 return skb_rtable(skb)->rt_iif; 307 } 308 309 extern int sysctl_ip_default_ttl; 310 311 static inline int ip4_dst_hoplimit(const struct dst_entry *dst) 312 { 313 int hoplimit = dst_metric_raw(dst, RTAX_HOPLIMIT); 314 315 if (hoplimit == 0) 316 hoplimit = sysctl_ip_default_ttl; 317 return hoplimit; 318 } 319 320 #endif /* _ROUTE_H */ 321