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 rtable { 53 struct dst_entry dst; 54 55 /* Cache lookup keys */ 56 struct flowi fl; 57 58 int rt_genid; 59 unsigned rt_flags; 60 __u16 rt_type; 61 62 __be32 rt_dst; /* Path destination */ 63 __be32 rt_src; /* Path source */ 64 int rt_iif; 65 66 /* Info on neighbour */ 67 __be32 rt_gateway; 68 69 /* Miscellaneous cached information */ 70 __be32 rt_spec_dst; /* RFC1122 specific destination */ 71 struct inet_peer *peer; /* long-living peer info */ 72 }; 73 74 static inline bool rt_is_input_route(struct rtable *rt) 75 { 76 return rt->fl.iif != 0; 77 } 78 79 static inline bool rt_is_output_route(struct rtable *rt) 80 { 81 return rt->fl.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 int __ip_route_output_key(struct net *, struct rtable **, const struct flowi *flp); 119 extern int ip_route_output_key(struct net *, struct rtable **, struct flowi *flp); 120 extern int ip_route_output_flow(struct net *, struct rtable **rp, struct flowi *flp, struct sock *sk, int flags); 121 122 extern int ip_route_input_common(struct sk_buff *skb, __be32 dst, __be32 src, 123 u8 tos, struct net_device *devin, bool noref); 124 125 static inline int ip_route_input(struct sk_buff *skb, __be32 dst, __be32 src, 126 u8 tos, struct net_device *devin) 127 { 128 return ip_route_input_common(skb, dst, src, tos, devin, false); 129 } 130 131 static inline int ip_route_input_noref(struct sk_buff *skb, __be32 dst, __be32 src, 132 u8 tos, struct net_device *devin) 133 { 134 return ip_route_input_common(skb, dst, src, tos, devin, true); 135 } 136 137 extern unsigned short ip_rt_frag_needed(struct net *net, struct iphdr *iph, unsigned short new_mtu, struct net_device *dev); 138 extern void ip_rt_send_redirect(struct sk_buff *skb); 139 140 extern unsigned inet_addr_type(struct net *net, __be32 addr); 141 extern unsigned inet_dev_addr_type(struct net *net, const struct net_device *dev, __be32 addr); 142 extern void ip_rt_multicast_event(struct in_device *); 143 extern int ip_rt_ioctl(struct net *, unsigned int cmd, void __user *arg); 144 extern void ip_rt_get_source(u8 *src, struct rtable *rt); 145 extern int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb); 146 147 struct in_ifaddr; 148 extern void fib_add_ifaddr(struct in_ifaddr *); 149 150 static inline void ip_rt_put(struct rtable * rt) 151 { 152 if (rt) 153 dst_release(&rt->dst); 154 } 155 156 #define IPTOS_RT_MASK (IPTOS_TOS_MASK & ~3) 157 158 extern const __u8 ip_tos2prio[16]; 159 160 static inline char rt_tos2priority(u8 tos) 161 { 162 return ip_tos2prio[IPTOS_TOS(tos)>>1]; 163 } 164 165 static inline int ip_route_connect(struct rtable **rp, __be32 dst, 166 __be32 src, u32 tos, int oif, u8 protocol, 167 __be16 sport, __be16 dport, struct sock *sk, 168 int flags) 169 { 170 struct flowi fl = { .oif = oif, 171 .mark = sk->sk_mark, 172 .fl4_dst = dst, 173 .fl4_src = src, 174 .fl4_tos = tos, 175 .proto = protocol, 176 .fl_ip_sport = sport, 177 .fl_ip_dport = dport }; 178 int err; 179 struct net *net = sock_net(sk); 180 181 if (inet_sk(sk)->transparent) 182 fl.flags |= FLOWI_FLAG_ANYSRC; 183 184 if (!dst || !src) { 185 err = __ip_route_output_key(net, rp, &fl); 186 if (err) 187 return err; 188 fl.fl4_dst = (*rp)->rt_dst; 189 fl.fl4_src = (*rp)->rt_src; 190 ip_rt_put(*rp); 191 *rp = NULL; 192 } 193 security_sk_classify_flow(sk, &fl); 194 return ip_route_output_flow(net, rp, &fl, sk, flags); 195 } 196 197 static inline int ip_route_newports(struct rtable **rp, u8 protocol, 198 __be16 sport, __be16 dport, struct sock *sk) 199 { 200 if (sport != (*rp)->fl.fl_ip_sport || 201 dport != (*rp)->fl.fl_ip_dport) { 202 struct flowi fl; 203 204 memcpy(&fl, &(*rp)->fl, sizeof(fl)); 205 fl.fl_ip_sport = sport; 206 fl.fl_ip_dport = dport; 207 fl.proto = protocol; 208 if (inet_sk(sk)->transparent) 209 fl.flags |= FLOWI_FLAG_ANYSRC; 210 ip_rt_put(*rp); 211 *rp = NULL; 212 security_sk_classify_flow(sk, &fl); 213 return ip_route_output_flow(sock_net(sk), rp, &fl, sk, 0); 214 } 215 return 0; 216 } 217 218 extern void rt_bind_peer(struct rtable *rt, int create); 219 220 static inline struct inet_peer *rt_get_peer(struct rtable *rt) 221 { 222 if (rt->peer) 223 return rt->peer; 224 225 rt_bind_peer(rt, 0); 226 return rt->peer; 227 } 228 229 static inline int inet_iif(const struct sk_buff *skb) 230 { 231 return skb_rtable(skb)->rt_iif; 232 } 233 234 extern int sysctl_ip_default_ttl; 235 236 static inline int ip4_dst_hoplimit(const struct dst_entry *dst) 237 { 238 int hoplimit = dst_metric_raw(dst, RTAX_HOPLIMIT); 239 240 if (hoplimit == 0) 241 hoplimit = sysctl_ip_default_ttl; 242 return hoplimit; 243 } 244 245 #endif /* _ROUTE_H */ 246