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 /* Cache lookup keys */ 57 struct flowi fl; 58 59 int rt_genid; 60 unsigned rt_flags; 61 __u16 rt_type; 62 63 __be32 rt_dst; /* Path destination */ 64 __be32 rt_src; /* Path source */ 65 int rt_iif; 66 67 /* Info on neighbour */ 68 __be32 rt_gateway; 69 70 /* Miscellaneous cached information */ 71 __be32 rt_spec_dst; /* RFC1122 specific destination */ 72 u32 rt_peer_genid; 73 struct inet_peer *peer; /* long-living peer info */ 74 struct fib_info *fi; /* for client ref to shared metrics */ 75 }; 76 77 static inline bool rt_is_input_route(struct rtable *rt) 78 { 79 return rt->fl.iif != 0; 80 } 81 82 static inline bool rt_is_output_route(struct rtable *rt) 83 { 84 return rt->fl.iif == 0; 85 } 86 87 struct ip_rt_acct { 88 __u32 o_bytes; 89 __u32 o_packets; 90 __u32 i_bytes; 91 __u32 i_packets; 92 }; 93 94 struct rt_cache_stat { 95 unsigned int in_hit; 96 unsigned int in_slow_tot; 97 unsigned int in_slow_mc; 98 unsigned int in_no_route; 99 unsigned int in_brd; 100 unsigned int in_martian_dst; 101 unsigned int in_martian_src; 102 unsigned int out_hit; 103 unsigned int out_slow_tot; 104 unsigned int out_slow_mc; 105 unsigned int gc_total; 106 unsigned int gc_ignored; 107 unsigned int gc_goal_miss; 108 unsigned int gc_dst_overflow; 109 unsigned int in_hlist_search; 110 unsigned int out_hlist_search; 111 }; 112 113 extern struct ip_rt_acct __percpu *ip_rt_acct; 114 115 struct in_device; 116 extern int ip_rt_init(void); 117 extern void ip_rt_redirect(__be32 old_gw, __be32 dst, __be32 new_gw, 118 __be32 src, struct net_device *dev); 119 extern void rt_cache_flush(struct net *net, int how); 120 extern void rt_cache_flush_batch(struct net *net); 121 extern int __ip_route_output_key(struct net *, struct rtable **, const struct flowi *flp); 122 extern int ip_route_output_key(struct net *, struct rtable **, struct flowi *flp); 123 extern int ip_route_output_flow(struct net *, struct rtable **rp, struct flowi *flp, struct sock *sk, int flags); 124 125 extern int ip_route_input_common(struct sk_buff *skb, __be32 dst, __be32 src, 126 u8 tos, struct net_device *devin, bool noref); 127 128 static inline int ip_route_input(struct sk_buff *skb, __be32 dst, __be32 src, 129 u8 tos, struct net_device *devin) 130 { 131 return ip_route_input_common(skb, dst, src, tos, devin, false); 132 } 133 134 static inline int ip_route_input_noref(struct sk_buff *skb, __be32 dst, __be32 src, 135 u8 tos, struct net_device *devin) 136 { 137 return ip_route_input_common(skb, dst, src, tos, devin, true); 138 } 139 140 extern unsigned short ip_rt_frag_needed(struct net *net, struct iphdr *iph, unsigned short new_mtu, struct net_device *dev); 141 extern void ip_rt_send_redirect(struct sk_buff *skb); 142 143 extern unsigned inet_addr_type(struct net *net, __be32 addr); 144 extern unsigned inet_dev_addr_type(struct net *net, const struct net_device *dev, __be32 addr); 145 extern void ip_rt_multicast_event(struct in_device *); 146 extern int ip_rt_ioctl(struct net *, unsigned int cmd, void __user *arg); 147 extern void ip_rt_get_source(u8 *src, struct rtable *rt); 148 extern int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb); 149 150 struct in_ifaddr; 151 extern void fib_add_ifaddr(struct in_ifaddr *); 152 153 static inline void ip_rt_put(struct rtable * rt) 154 { 155 if (rt) 156 dst_release(&rt->dst); 157 } 158 159 #define IPTOS_RT_MASK (IPTOS_TOS_MASK & ~3) 160 161 extern const __u8 ip_tos2prio[16]; 162 163 static inline char rt_tos2priority(u8 tos) 164 { 165 return ip_tos2prio[IPTOS_TOS(tos)>>1]; 166 } 167 168 static inline int ip_route_connect(struct rtable **rp, __be32 dst, 169 __be32 src, u32 tos, int oif, u8 protocol, 170 __be16 sport, __be16 dport, struct sock *sk, 171 int flags) 172 { 173 struct flowi fl = { .oif = oif, 174 .mark = sk->sk_mark, 175 .fl4_dst = dst, 176 .fl4_src = src, 177 .fl4_tos = tos, 178 .proto = protocol, 179 .fl_ip_sport = sport, 180 .fl_ip_dport = dport }; 181 int err; 182 struct net *net = sock_net(sk); 183 184 if (inet_sk(sk)->transparent) 185 fl.flags |= FLOWI_FLAG_ANYSRC; 186 if (protocol == IPPROTO_TCP) 187 fl.flags |= FLOWI_FLAG_PRECOW_METRICS; 188 189 if (!dst || !src) { 190 err = __ip_route_output_key(net, rp, &fl); 191 if (err) 192 return err; 193 fl.fl4_dst = (*rp)->rt_dst; 194 fl.fl4_src = (*rp)->rt_src; 195 ip_rt_put(*rp); 196 *rp = NULL; 197 } 198 security_sk_classify_flow(sk, &fl); 199 return ip_route_output_flow(net, rp, &fl, sk, flags); 200 } 201 202 static inline int ip_route_newports(struct rtable **rp, u8 protocol, 203 __be16 sport, __be16 dport, struct sock *sk) 204 { 205 if (sport != (*rp)->fl.fl_ip_sport || 206 dport != (*rp)->fl.fl_ip_dport) { 207 struct flowi fl; 208 209 memcpy(&fl, &(*rp)->fl, sizeof(fl)); 210 fl.fl_ip_sport = sport; 211 fl.fl_ip_dport = dport; 212 fl.proto = protocol; 213 if (inet_sk(sk)->transparent) 214 fl.flags |= FLOWI_FLAG_ANYSRC; 215 if (protocol == IPPROTO_TCP) 216 fl.flags |= FLOWI_FLAG_PRECOW_METRICS; 217 ip_rt_put(*rp); 218 *rp = NULL; 219 security_sk_classify_flow(sk, &fl); 220 return ip_route_output_flow(sock_net(sk), rp, &fl, sk, 0); 221 } 222 return 0; 223 } 224 225 extern void rt_bind_peer(struct rtable *rt, int create); 226 227 static inline struct inet_peer *rt_get_peer(struct rtable *rt) 228 { 229 if (rt->peer) 230 return rt->peer; 231 232 rt_bind_peer(rt, 0); 233 return rt->peer; 234 } 235 236 static inline int inet_iif(const struct sk_buff *skb) 237 { 238 return skb_rtable(skb)->rt_iif; 239 } 240 241 extern int sysctl_ip_default_ttl; 242 243 static inline int ip4_dst_hoplimit(const struct dst_entry *dst) 244 { 245 int hoplimit = dst_metric_raw(dst, RTAX_HOPLIMIT); 246 247 if (hoplimit == 0) 248 hoplimit = sysctl_ip_default_ttl; 249 return hoplimit; 250 } 251 252 #endif /* _ROUTE_H */ 253