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_iif; 68 int rt_oif; 69 __u32 rt_mark; 70 71 /* Info on neighbour */ 72 __be32 rt_gateway; 73 74 /* Miscellaneous cached information */ 75 __be32 rt_spec_dst; /* RFC1122 specific destination */ 76 u32 rt_peer_genid; 77 struct inet_peer *peer; /* long-living peer info */ 78 struct fib_info *fi; /* for client ref to shared metrics */ 79 }; 80 81 static inline bool rt_is_input_route(struct rtable *rt) 82 { 83 return rt->rt_iif != 0; 84 } 85 86 static inline bool rt_is_output_route(struct rtable *rt) 87 { 88 return rt->rt_iif == 0; 89 } 90 91 struct ip_rt_acct { 92 __u32 o_bytes; 93 __u32 o_packets; 94 __u32 i_bytes; 95 __u32 i_packets; 96 }; 97 98 struct rt_cache_stat { 99 unsigned int in_hit; 100 unsigned int in_slow_tot; 101 unsigned int in_slow_mc; 102 unsigned int in_no_route; 103 unsigned int in_brd; 104 unsigned int in_martian_dst; 105 unsigned int in_martian_src; 106 unsigned int out_hit; 107 unsigned int out_slow_tot; 108 unsigned int out_slow_mc; 109 unsigned int gc_total; 110 unsigned int gc_ignored; 111 unsigned int gc_goal_miss; 112 unsigned int gc_dst_overflow; 113 unsigned int in_hlist_search; 114 unsigned int out_hlist_search; 115 }; 116 117 extern struct ip_rt_acct __percpu *ip_rt_acct; 118 119 struct in_device; 120 extern int ip_rt_init(void); 121 extern void ip_rt_redirect(__be32 old_gw, __be32 dst, __be32 new_gw, 122 __be32 src, struct net_device *dev); 123 extern void rt_cache_flush(struct net *net, int how); 124 extern void rt_cache_flush_batch(struct net *net); 125 extern struct rtable *__ip_route_output_key(struct net *, const struct flowi *flp); 126 extern struct rtable *ip_route_output_flow(struct net *, struct flowi *flp, 127 struct sock *sk); 128 extern struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig); 129 130 static inline struct rtable *ip_route_output_key(struct net *net, struct flowi *flp) 131 { 132 return ip_route_output_flow(net, flp, NULL); 133 } 134 135 static inline struct rtable *ip_route_output(struct net *net, __be32 daddr, 136 __be32 saddr, u8 tos, int oif) 137 { 138 struct flowi fl = { 139 .oif = oif, 140 .fl4_dst = daddr, 141 .fl4_src = saddr, 142 .fl4_tos = tos, 143 }; 144 return ip_route_output_key(net, &fl); 145 } 146 147 static inline struct rtable *ip_route_output_ports(struct net *net, struct sock *sk, 148 __be32 daddr, __be32 saddr, 149 __be16 dport, __be16 sport, 150 __u8 proto, __u8 tos, int oif) 151 { 152 struct flowi fl = { 153 .oif = oif, 154 .flags = sk ? inet_sk_flowi_flags(sk) : 0, 155 .mark = sk ? sk->sk_mark : 0, 156 .fl4_dst = daddr, 157 .fl4_src = saddr, 158 .fl4_tos = tos, 159 .proto = proto, 160 .fl_ip_dport = dport, 161 .fl_ip_sport = sport, 162 }; 163 if (sk) 164 security_sk_classify_flow(sk, &fl); 165 return ip_route_output_flow(net, &fl, sk); 166 } 167 168 static inline struct rtable *ip_route_output_gre(struct net *net, 169 __be32 daddr, __be32 saddr, 170 __be32 gre_key, __u8 tos, int oif) 171 { 172 struct flowi fl = { 173 .oif = oif, 174 .fl4_dst = daddr, 175 .fl4_src = saddr, 176 .fl4_tos = tos, 177 .proto = IPPROTO_GRE, 178 .fl_gre_key = gre_key, 179 }; 180 return ip_route_output_key(net, &fl); 181 } 182 183 extern int ip_route_input_common(struct sk_buff *skb, __be32 dst, __be32 src, 184 u8 tos, struct net_device *devin, bool noref); 185 186 static inline int ip_route_input(struct sk_buff *skb, __be32 dst, __be32 src, 187 u8 tos, struct net_device *devin) 188 { 189 return ip_route_input_common(skb, dst, src, tos, devin, false); 190 } 191 192 static inline int ip_route_input_noref(struct sk_buff *skb, __be32 dst, __be32 src, 193 u8 tos, struct net_device *devin) 194 { 195 return ip_route_input_common(skb, dst, src, tos, devin, true); 196 } 197 198 extern unsigned short ip_rt_frag_needed(struct net *net, struct iphdr *iph, unsigned short new_mtu, struct net_device *dev); 199 extern void ip_rt_send_redirect(struct sk_buff *skb); 200 201 extern unsigned inet_addr_type(struct net *net, __be32 addr); 202 extern unsigned inet_dev_addr_type(struct net *net, const struct net_device *dev, __be32 addr); 203 extern void ip_rt_multicast_event(struct in_device *); 204 extern int ip_rt_ioctl(struct net *, unsigned int cmd, void __user *arg); 205 extern void ip_rt_get_source(u8 *src, struct rtable *rt); 206 extern int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb); 207 208 struct in_ifaddr; 209 extern void fib_add_ifaddr(struct in_ifaddr *); 210 211 static inline void ip_rt_put(struct rtable * rt) 212 { 213 if (rt) 214 dst_release(&rt->dst); 215 } 216 217 #define IPTOS_RT_MASK (IPTOS_TOS_MASK & ~3) 218 219 extern const __u8 ip_tos2prio[16]; 220 221 static inline char rt_tos2priority(u8 tos) 222 { 223 return ip_tos2prio[IPTOS_TOS(tos)>>1]; 224 } 225 226 static inline struct rtable *ip_route_connect(__be32 dst, __be32 src, u32 tos, 227 int oif, u8 protocol, 228 __be16 sport, __be16 dport, 229 struct sock *sk, bool can_sleep) 230 { 231 struct flowi fl = { .oif = oif, 232 .mark = sk->sk_mark, 233 .fl4_dst = dst, 234 .fl4_src = src, 235 .fl4_tos = tos, 236 .proto = protocol, 237 .fl_ip_sport = sport, 238 .fl_ip_dport = dport }; 239 struct net *net = sock_net(sk); 240 struct rtable *rt; 241 242 if (inet_sk(sk)->transparent) 243 fl.flags |= FLOWI_FLAG_ANYSRC; 244 if (protocol == IPPROTO_TCP) 245 fl.flags |= FLOWI_FLAG_PRECOW_METRICS; 246 if (can_sleep) 247 fl.flags |= FLOWI_FLAG_CAN_SLEEP; 248 249 if (!dst || !src) { 250 rt = __ip_route_output_key(net, &fl); 251 if (IS_ERR(rt)) 252 return rt; 253 fl.fl4_dst = rt->rt_dst; 254 fl.fl4_src = rt->rt_src; 255 ip_rt_put(rt); 256 } 257 security_sk_classify_flow(sk, &fl); 258 return ip_route_output_flow(net, &fl, sk); 259 } 260 261 static inline struct rtable *ip_route_newports(struct rtable *rt, 262 u8 protocol, __be16 orig_sport, 263 __be16 orig_dport, __be16 sport, 264 __be16 dport, struct sock *sk) 265 { 266 if (sport != orig_sport || dport != orig_dport) { 267 struct flowi fl = { .oif = rt->rt_oif, 268 .mark = rt->rt_mark, 269 .fl4_dst = rt->rt_key_dst, 270 .fl4_src = rt->rt_key_src, 271 .fl4_tos = rt->rt_tos, 272 .proto = protocol, 273 .fl_ip_sport = sport, 274 .fl_ip_dport = dport }; 275 276 if (inet_sk(sk)->transparent) 277 fl.flags |= FLOWI_FLAG_ANYSRC; 278 if (protocol == IPPROTO_TCP) 279 fl.flags |= FLOWI_FLAG_PRECOW_METRICS; 280 ip_rt_put(rt); 281 security_sk_classify_flow(sk, &fl); 282 return ip_route_output_flow(sock_net(sk), &fl, sk); 283 } 284 return rt; 285 } 286 287 extern void rt_bind_peer(struct rtable *rt, int create); 288 289 static inline struct inet_peer *rt_get_peer(struct rtable *rt) 290 { 291 if (rt->peer) 292 return rt->peer; 293 294 rt_bind_peer(rt, 0); 295 return rt->peer; 296 } 297 298 static inline int inet_iif(const struct sk_buff *skb) 299 { 300 return skb_rtable(skb)->rt_iif; 301 } 302 303 extern int sysctl_ip_default_ttl; 304 305 static inline int ip4_dst_hoplimit(const struct dst_entry *dst) 306 { 307 int hoplimit = dst_metric_raw(dst, RTAX_HOPLIMIT); 308 309 if (hoplimit == 0) 310 hoplimit = sysctl_ip_default_ttl; 311 return hoplimit; 312 } 313 314 #endif /* _ROUTE_H */ 315