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 fib_info; 44 struct rtable { 45 struct dst_entry dst; 46 47 int rt_genid; 48 unsigned int rt_flags; 49 __u16 rt_type; 50 __u16 rt_is_input; 51 52 int rt_iif; 53 54 /* Info on neighbour */ 55 __be32 rt_gateway; 56 57 /* Miscellaneous cached information */ 58 u32 rt_pmtu; 59 struct fib_info *fi; /* for client ref to shared metrics */ 60 }; 61 62 static inline bool rt_is_input_route(const struct rtable *rt) 63 { 64 return rt->rt_is_input != 0; 65 } 66 67 static inline bool rt_is_output_route(const struct rtable *rt) 68 { 69 return rt->rt_is_input == 0; 70 } 71 72 static 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 79 struct ip_rt_acct { 80 __u32 o_bytes; 81 __u32 o_packets; 82 __u32 i_bytes; 83 __u32 i_packets; 84 }; 85 86 struct 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 }; 104 105 extern struct ip_rt_acct __percpu *ip_rt_acct; 106 107 struct in_device; 108 extern int ip_rt_init(void); 109 extern void rt_cache_flush(struct net *net, int how); 110 extern struct rtable *__ip_route_output_key(struct net *, struct flowi4 *flp); 111 extern struct rtable *ip_route_output_flow(struct net *, struct flowi4 *flp, 112 struct sock *sk); 113 extern struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig); 114 115 static inline struct rtable *ip_route_output_key(struct net *net, struct flowi4 *flp) 116 { 117 return ip_route_output_flow(net, flp, NULL); 118 } 119 120 static 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 } 131 132 static 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 } 146 147 static 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 } 160 161 extern int ip_route_input(struct sk_buff *skb, __be32 dst, __be32 src, 162 u8 tos, struct net_device *devin); 163 164 extern void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu, 165 int oif, u32 mark, u8 protocol, int flow_flags); 166 extern void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu); 167 extern void ipv4_redirect(struct sk_buff *skb, struct net *net, 168 int oif, u32 mark, u8 protocol, int flow_flags); 169 extern void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk); 170 extern void ip_rt_send_redirect(struct sk_buff *skb); 171 172 extern unsigned int inet_addr_type(struct net *net, __be32 addr); 173 extern unsigned int inet_dev_addr_type(struct net *net, const struct net_device *dev, __be32 addr); 174 extern void ip_rt_multicast_event(struct in_device *); 175 extern int ip_rt_ioctl(struct net *, unsigned int cmd, void __user *arg); 176 extern void ip_rt_get_source(u8 *src, struct sk_buff *skb, struct rtable *rt); 177 extern int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb); 178 179 struct in_ifaddr; 180 extern void fib_add_ifaddr(struct in_ifaddr *); 181 extern void fib_del_ifaddr(struct in_ifaddr *, struct in_ifaddr *); 182 183 static inline void ip_rt_put(struct rtable * rt) 184 { 185 if (rt) 186 dst_release(&rt->dst); 187 } 188 189 #define IPTOS_RT_MASK (IPTOS_TOS_MASK & ~3) 190 191 extern const __u8 ip_tos2prio[16]; 192 193 static inline char rt_tos2priority(u8 tos) 194 { 195 return ip_tos2prio[IPTOS_TOS(tos)>>1]; 196 } 197 198 /* ip_route_connect() and ip_route_newports() work in tandem whilst 199 * binding a socket for a new outgoing connection. 200 * 201 * In order to use IPSEC properly, we must, in the end, have a 202 * route that was looked up using all available keys including source 203 * and destination ports. 204 * 205 * However, if a source port needs to be allocated (the user specified 206 * a wildcard source port) we need to obtain addressing information 207 * in order to perform that allocation. 208 * 209 * So ip_route_connect() looks up a route using wildcarded source and 210 * destination ports in the key, simply so that we can get a pair of 211 * addresses to use for port allocation. 212 * 213 * Later, once the ports are allocated, ip_route_newports() will make 214 * another route lookup if needed to make sure we catch any IPSEC 215 * rules keyed on the port information. 216 * 217 * The callers allocate the flow key on their stack, and must pass in 218 * the same flowi4 object to both the ip_route_connect() and the 219 * ip_route_newports() calls. 220 */ 221 222 static inline void ip_route_connect_init(struct flowi4 *fl4, __be32 dst, __be32 src, 223 u32 tos, int oif, u8 protocol, 224 __be16 sport, __be16 dport, 225 struct sock *sk, bool can_sleep) 226 { 227 __u8 flow_flags = 0; 228 229 if (inet_sk(sk)->transparent) 230 flow_flags |= FLOWI_FLAG_ANYSRC; 231 if (can_sleep) 232 flow_flags |= FLOWI_FLAG_CAN_SLEEP; 233 234 flowi4_init_output(fl4, oif, sk->sk_mark, tos, RT_SCOPE_UNIVERSE, 235 protocol, flow_flags, dst, src, dport, sport); 236 } 237 238 static inline struct rtable *ip_route_connect(struct flowi4 *fl4, 239 __be32 dst, __be32 src, u32 tos, 240 int oif, u8 protocol, 241 __be16 sport, __be16 dport, 242 struct sock *sk, bool can_sleep) 243 { 244 struct net *net = sock_net(sk); 245 struct rtable *rt; 246 247 ip_route_connect_init(fl4, dst, src, tos, oif, protocol, 248 sport, dport, sk, can_sleep); 249 250 if (!dst || !src) { 251 rt = __ip_route_output_key(net, fl4); 252 if (IS_ERR(rt)) 253 return rt; 254 ip_rt_put(rt); 255 flowi4_update_output(fl4, oif, tos, fl4->daddr, fl4->saddr); 256 } 257 security_sk_classify_flow(sk, flowi4_to_flowi(fl4)); 258 return ip_route_output_flow(net, fl4, sk); 259 } 260 261 static inline struct rtable *ip_route_newports(struct flowi4 *fl4, struct rtable *rt, 262 __be16 orig_sport, __be16 orig_dport, 263 __be16 sport, __be16 dport, 264 struct sock *sk) 265 { 266 if (sport != orig_sport || dport != orig_dport) { 267 fl4->fl4_dport = dport; 268 fl4->fl4_sport = sport; 269 ip_rt_put(rt); 270 flowi4_update_output(fl4, sk->sk_bound_dev_if, 271 RT_CONN_FLAGS(sk), fl4->daddr, 272 fl4->saddr); 273 security_sk_classify_flow(sk, flowi4_to_flowi(fl4)); 274 return ip_route_output_flow(sock_net(sk), fl4, sk); 275 } 276 return rt; 277 } 278 279 static inline int inet_iif(const struct sk_buff *skb) 280 { 281 return skb_rtable(skb)->rt_iif; 282 } 283 284 extern int sysctl_ip_default_ttl; 285 286 static inline int ip4_dst_hoplimit(const struct dst_entry *dst) 287 { 288 int hoplimit = dst_metric_raw(dst, RTAX_HOPLIMIT); 289 290 if (hoplimit == 0) 291 hoplimit = sysctl_ip_default_ttl; 292 return hoplimit; 293 } 294 295 #endif /* _ROUTE_H */ 296