include/net/route.h

   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_route_iif;
  68         int                     rt_iif;
  69         int                     rt_oif;
  70         __u32                   rt_mark;
  71
  72         /* Info on neighbour */
  73         __be32                  rt_gateway;
  74
  75         /* Miscellaneous cached information */
  76         __be32                  rt_spec_dst; /* RFC1122 specific destination */
  77         u32                     rt_peer_genid;
  78         struct inet_peer        *peer; /* long-living peer info */
  79         struct fib_info         *fi; /* for client ref to shared metrics */
  80 };
  81
  82 static inline bool rt_is_input_route(struct rtable *rt)
  83 {
  84         return rt->rt_route_iif != 0;
  85 }
  86
  87 static inline bool rt_is_output_route(struct rtable *rt)
  88 {
  89         return rt->rt_route_iif == 0;
  90 }
  91
  92 struct ip_rt_acct {
  93         __u32   o_bytes;
  94         __u32   o_packets;
  95         __u32   i_bytes;
  96         __u32   i_packets;
  97 };
  98
  99 struct rt_cache_stat {
 100         unsigned int in_hit;
 101         unsigned int in_slow_tot;
 102         unsigned int in_slow_mc;
 103         unsigned int in_no_route;
 104         unsigned int in_brd;
 105         unsigned int in_martian_dst;
 106         unsigned int in_martian_src;
 107         unsigned int out_hit;
 108         unsigned int out_slow_tot;
 109         unsigned int out_slow_mc;
 110         unsigned int gc_total;
 111         unsigned int gc_ignored;
 112         unsigned int gc_goal_miss;
 113         unsigned int gc_dst_overflow;
 114         unsigned int in_hlist_search;
 115         unsigned int out_hlist_search;
 116 };
 117
 118 extern struct ip_rt_acct __percpu *ip_rt_acct;
 119
 120 struct in_device;
 121 extern int              ip_rt_init(void);
 122 extern void             ip_rt_redirect(__be32 old_gw, __be32 dst, __be32 new_gw,
 123                                        __be32 src, struct net_device *dev);
 124 extern void             rt_cache_flush(struct net *net, int how);
 125 extern void             rt_cache_flush_batch(struct net *net);
 126 extern struct rtable *__ip_route_output_key(struct net *, const struct flowi4 *flp);
 127 extern struct rtable *ip_route_output_flow(struct net *, struct flowi4 *flp,
 128                                            struct sock *sk);
 129 extern struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig);
 130
 131 static inline struct rtable *ip_route_output_key(struct net *net, struct flowi4 *flp)
 132 {
 133         return ip_route_output_flow(net, flp, NULL);
 134 }
 135
 136 static inline struct rtable *ip_route_output(struct net *net, __be32 daddr,
 137                                              __be32 saddr, u8 tos, int oif)
 138 {
 139         struct flowi4 fl4 = {
 140                 .flowi4_oif = oif,
 141                 .daddr = daddr,
 142                 .saddr = saddr,
 143                 .flowi4_tos = tos,
 144         };
 145         return ip_route_output_key(net, &fl4);
 146 }
 147
 148 static inline struct rtable *ip_route_output_ports(struct net *net, struct sock *sk,
 149                                                    __be32 daddr, __be32 saddr,
 150                                                    __be16 dport, __be16 sport,
 151                                                    __u8 proto, __u8 tos, int oif)
 152 {
 153         struct flowi4 fl4 = {
 154                 .flowi4_oif = oif,
 155                 .flowi4_flags = sk ? inet_sk_flowi_flags(sk) : 0,
 156                 .flowi4_mark = sk ? sk->sk_mark : 0,
 157                 .daddr = daddr,
 158                 .saddr = saddr,
 159                 .flowi4_tos = tos,
 160                 .flowi4_proto = proto,
 161                 .fl4_dport = dport,
 162                 .fl4_sport = sport,
 163         };
 164         if (sk)
 165                 security_sk_classify_flow(sk, flowi4_to_flowi(&fl4));
 166         return ip_route_output_flow(net, &fl4, sk);
 167 }
 168
 169 static inline struct rtable *ip_route_output_gre(struct net *net,
 170                                                  __be32 daddr, __be32 saddr,
 171                                                  __be32 gre_key, __u8 tos, int oif)
 172 {
 173         struct flowi4 fl4 = {
 174                 .flowi4_oif = oif,
 175                 .daddr = daddr,
 176                 .saddr = saddr,
 177                 .flowi4_tos = tos,
 178                 .flowi4_proto = IPPROTO_GRE,
 179                 .fl4_gre_key = gre_key,
 180         };
 181         return ip_route_output_key(net, &fl4);
 182 }
 183
 184 extern int ip_route_input_common(struct sk_buff *skb, __be32 dst, __be32 src,
 185                                  u8 tos, struct net_device *devin, bool noref);
 186
 187 static inline int ip_route_input(struct sk_buff *skb, __be32 dst, __be32 src,
 188                                  u8 tos, struct net_device *devin)
 189 {
 190         return ip_route_input_common(skb, dst, src, tos, devin, false);
 191 }
 192
 193 static inline int ip_route_input_noref(struct sk_buff *skb, __be32 dst, __be32 src,
 194                                        u8 tos, struct net_device *devin)
 195 {
 196         return ip_route_input_common(skb, dst, src, tos, devin, true);
 197 }
 198
 199 extern unsigned short   ip_rt_frag_needed(struct net *net, struct iphdr *iph, unsigned short new_mtu, struct net_device *dev);
 200 extern void             ip_rt_send_redirect(struct sk_buff *skb);
 201
 202 extern unsigned         inet_addr_type(struct net *net, __be32 addr);
 203 extern unsigned         inet_dev_addr_type(struct net *net, const struct net_device *dev, __be32 addr);
 204 extern void             ip_rt_multicast_event(struct in_device *);
 205 extern int              ip_rt_ioctl(struct net *, unsigned int cmd, void __user *arg);
 206 extern void             ip_rt_get_source(u8 *src, struct rtable *rt);
 207 extern int              ip_rt_dump(struct sk_buff *skb,  struct netlink_callback *cb);
 208
 209 struct in_ifaddr;
 210 extern void fib_add_ifaddr(struct in_ifaddr *);
 211 extern void fib_del_ifaddr(struct in_ifaddr *, struct in_ifaddr *);
 212
 213 static inline void ip_rt_put(struct rtable * rt)
 214 {
 215         if (rt)
 216                 dst_release(&rt->dst);
 217 }
 218
 219 #define IPTOS_RT_MASK   (IPTOS_TOS_MASK & ~3)
 220
 221 extern const __u8 ip_tos2prio[16];
 222
 223 static inline char rt_tos2priority(u8 tos)
 224 {
 225         return ip_tos2prio[IPTOS_TOS(tos)>>1];
 226 }
 227
 228 static inline struct rtable *ip_route_connect(__be32 dst, __be32 src, u32 tos,
 229                                               int oif, u8 protocol,
 230                                               __be16 sport, __be16 dport,
 231                                               struct sock *sk, bool can_sleep)
 232 {
 233         struct flowi4 fl4 = {
 234                 .flowi4_oif = oif,
 235                 .flowi4_mark = sk->sk_mark,
 236                 .daddr = dst,
 237                 .saddr = src,
 238                 .flowi4_tos = tos,
 239                 .flowi4_proto = protocol,
 240                 .fl4_sport = sport,
 241                 .fl4_dport = dport,
 242         };
 243         struct net *net = sock_net(sk);
 244         struct rtable *rt;
 245
 246         if (inet_sk(sk)->transparent)
 247                 fl4.flowi4_flags |= FLOWI_FLAG_ANYSRC;
 248         if (protocol == IPPROTO_TCP)
 249                 fl4.flowi4_flags |= FLOWI_FLAG_PRECOW_METRICS;
 250         if (can_sleep)
 251                 fl4.flowi4_flags |= FLOWI_FLAG_CAN_SLEEP;
 252
 253         if (!dst || !src) {
 254                 rt = __ip_route_output_key(net, &fl4);
 255                 if (IS_ERR(rt))
 256                         return rt;
 257                 fl4.daddr = rt->rt_dst;
 258                 fl4.saddr = rt->rt_src;
 259                 ip_rt_put(rt);
 260         }
 261         security_sk_classify_flow(sk, flowi4_to_flowi(&fl4));
 262         return ip_route_output_flow(net, &fl4, sk);
 263 }
 264
 265 static inline struct rtable *ip_route_newports(struct rtable *rt,
 266                                                u8 protocol, __be16 orig_sport,
 267                                                __be16 orig_dport, __be16 sport,
 268                                                __be16 dport, struct sock *sk)
 269 {
 270         if (sport != orig_sport || dport != orig_dport) {
 271                 struct flowi4 fl4 = {
 272                         .flowi4_oif = rt->rt_oif,
 273                         .flowi4_mark = rt->rt_mark,
 274                         .daddr = rt->rt_dst,
 275                         .saddr = rt->rt_src,
 276                         .flowi4_tos = rt->rt_tos,
 277                         .flowi4_proto = protocol,
 278                         .fl4_sport = sport,
 279                         .fl4_dport = dport
 280                 };
 281                 if (inet_sk(sk)->transparent)
 282                         fl4.flowi4_flags |= FLOWI_FLAG_ANYSRC;
 283                 if (protocol == IPPROTO_TCP)
 284                         fl4.flowi4_flags |= FLOWI_FLAG_PRECOW_METRICS;
 285                 ip_rt_put(rt);
 286                 security_sk_classify_flow(sk, flowi4_to_flowi(&fl4));
 287                 return ip_route_output_flow(sock_net(sk), &fl4, sk);
 288         }
 289         return rt;
 290 }
 291
 292 extern void rt_bind_peer(struct rtable *rt, int create);
 293
 294 static inline struct inet_peer *rt_get_peer(struct rtable *rt)
 295 {
 296         if (rt->peer)
 297                 return rt->peer;
 298
 299         rt_bind_peer(rt, 0);
 300         return rt->peer;
 301 }
 302
 303 static inline int inet_iif(const struct sk_buff *skb)
 304 {
 305         return skb_rtable(skb)->rt_iif;
 306 }
 307
 308 extern int sysctl_ip_default_ttl;
 309
 310 static inline int ip4_dst_hoplimit(const struct dst_entry *dst)
 311 {
 312         int hoplimit = dst_metric_raw(dst, RTAX_HOPLIMIT);
 313
 314         if (hoplimit == 0)
 315                 hoplimit = sysctl_ip_default_ttl;
 316         return hoplimit;
 317 }
 318
 319 #endif  /* _ROUTE_H */