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 struct rtable *__ip_route_output_key(struct net *, const struct flowi *flp); 122 extern struct rtable *ip_route_output_flow(struct net *, struct flowi *flp, 123 struct sock *sk); 124 extern struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig); 125 126 static inline struct rtable *ip_route_output_key(struct net *net, struct flowi *flp) 127 { 128 return ip_route_output_flow(net, flp, NULL); 129 } 130 131 extern int ip_route_input_common(struct sk_buff *skb, __be32 dst, __be32 src, 132 u8 tos, struct net_device *devin, bool noref); 133 134 static inline int ip_route_input(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, false); 138 } 139 140 static inline int ip_route_input_noref(struct sk_buff *skb, __be32 dst, __be32 src, 141 u8 tos, struct net_device *devin) 142 { 143 return ip_route_input_common(skb, dst, src, tos, devin, true); 144 } 145 146 extern unsigned short ip_rt_frag_needed(struct net *net, struct iphdr *iph, unsigned short new_mtu, struct net_device *dev); 147 extern void ip_rt_send_redirect(struct sk_buff *skb); 148 149 extern unsigned inet_addr_type(struct net *net, __be32 addr); 150 extern unsigned inet_dev_addr_type(struct net *net, const struct net_device *dev, __be32 addr); 151 extern void ip_rt_multicast_event(struct in_device *); 152 extern int ip_rt_ioctl(struct net *, unsigned int cmd, void __user *arg); 153 extern void ip_rt_get_source(u8 *src, struct rtable *rt); 154 extern int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb); 155 156 struct in_ifaddr; 157 extern void fib_add_ifaddr(struct in_ifaddr *); 158 159 static inline void ip_rt_put(struct rtable * rt) 160 { 161 if (rt) 162 dst_release(&rt->dst); 163 } 164 165 #define IPTOS_RT_MASK (IPTOS_TOS_MASK & ~3) 166 167 extern const __u8 ip_tos2prio[16]; 168 169 static inline char rt_tos2priority(u8 tos) 170 { 171 return ip_tos2prio[IPTOS_TOS(tos)>>1]; 172 } 173 174 static inline struct rtable *ip_route_connect(__be32 dst, __be32 src, u32 tos, 175 int oif, u8 protocol, 176 __be16 sport, __be16 dport, 177 struct sock *sk, bool can_sleep) 178 { 179 struct flowi fl = { .oif = oif, 180 .mark = sk->sk_mark, 181 .fl4_dst = dst, 182 .fl4_src = src, 183 .fl4_tos = tos, 184 .proto = protocol, 185 .fl_ip_sport = sport, 186 .fl_ip_dport = dport }; 187 struct net *net = sock_net(sk); 188 struct rtable *rt; 189 190 if (inet_sk(sk)->transparent) 191 fl.flags |= FLOWI_FLAG_ANYSRC; 192 if (protocol == IPPROTO_TCP) 193 fl.flags |= FLOWI_FLAG_PRECOW_METRICS; 194 if (can_sleep) 195 fl.flags |= FLOWI_FLAG_CAN_SLEEP; 196 197 if (!dst || !src) { 198 rt = __ip_route_output_key(net, &fl); 199 if (IS_ERR(rt)) 200 return rt; 201 fl.fl4_dst = rt->rt_dst; 202 fl.fl4_src = rt->rt_src; 203 ip_rt_put(rt); 204 } 205 security_sk_classify_flow(sk, &fl); 206 return ip_route_output_flow(net, &fl, sk); 207 } 208 209 static inline struct rtable *ip_route_newports(struct rtable *rt, 210 u8 protocol, __be16 orig_sport, 211 __be16 orig_dport, __be16 sport, 212 __be16 dport, struct sock *sk) 213 { 214 if (sport != orig_sport || dport != orig_dport) { 215 struct flowi fl = { .oif = rt->fl.oif, 216 .mark = rt->fl.mark, 217 .fl4_dst = rt->fl.fl4_dst, 218 .fl4_src = rt->fl.fl4_src, 219 .fl4_tos = rt->fl.fl4_tos, 220 .proto = rt->fl.proto, 221 .fl_ip_sport = sport, 222 .fl_ip_dport = dport }; 223 224 if (inet_sk(sk)->transparent) 225 fl.flags |= FLOWI_FLAG_ANYSRC; 226 if (protocol == IPPROTO_TCP) 227 fl.flags |= FLOWI_FLAG_PRECOW_METRICS; 228 ip_rt_put(rt); 229 security_sk_classify_flow(sk, &fl); 230 return ip_route_output_flow(sock_net(sk), &fl, sk); 231 } 232 return rt; 233 } 234 235 extern void rt_bind_peer(struct rtable *rt, int create); 236 237 static inline struct inet_peer *rt_get_peer(struct rtable *rt) 238 { 239 if (rt->peer) 240 return rt->peer; 241 242 rt_bind_peer(rt, 0); 243 return rt->peer; 244 } 245 246 static inline int inet_iif(const struct sk_buff *skb) 247 { 248 return skb_rtable(skb)->rt_iif; 249 } 250 251 extern int sysctl_ip_default_ttl; 252 253 static inline int ip4_dst_hoplimit(const struct dst_entry *dst) 254 { 255 int hoplimit = dst_metric_raw(dst, RTAX_HOPLIMIT); 256 257 if (hoplimit == 0) 258 hoplimit = sysctl_ip_default_ttl; 259 return hoplimit; 260 } 261 262 #endif /* _ROUTE_H */ 263