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_iif;
  68         int                     rt_oif;
  69         __u32                   rt_mark;
  70
  71         /* Info on neighbour */
  72         __be32                  rt_gateway;
  73
  74         /* Miscellaneous cached information */
  75         __be32                  rt_spec_dst; /* RFC1122 specific destination */
  76         u32                     rt_peer_genid;
  77         struct inet_peer        *peer; /* long-living peer info */
  78         struct fib_info         *fi; /* for client ref to shared metrics */
  79 };
  80
  81 static inline bool rt_is_input_route(struct rtable *rt)
  82 {
  83         return rt->rt_iif != 0;
  84 }
  85
  86 static inline bool rt_is_output_route(struct rtable *rt)
  87 {
  88         return rt->rt_iif == 0;
  89 }
  90
  91 struct ip_rt_acct {
  92         __u32   o_bytes;
  93         __u32   o_packets;
  94         __u32   i_bytes;
  95         __u32   i_packets;
  96 };
  97
  98 struct rt_cache_stat {
  99         unsigned int in_hit;
 100         unsigned int in_slow_tot;
 101         unsigned int in_slow_mc;
 102         unsigned int in_no_route;
 103         unsigned int in_brd;
 104         unsigned int in_martian_dst;
 105         unsigned int in_martian_src;
 106         unsigned int out_hit;
 107         unsigned int out_slow_tot;
 108         unsigned int out_slow_mc;
 109         unsigned int gc_total;
 110         unsigned int gc_ignored;
 111         unsigned int gc_goal_miss;
 112         unsigned int gc_dst_overflow;
 113         unsigned int in_hlist_search;
 114         unsigned int out_hlist_search;
 115 };
 116
 117 extern struct ip_rt_acct __percpu *ip_rt_acct;
 118
 119 struct in_device;
 120 extern int              ip_rt_init(void);
 121 extern void             ip_rt_redirect(__be32 old_gw, __be32 dst, __be32 new_gw,
 122                                        __be32 src, struct net_device *dev);
 123 extern void             rt_cache_flush(struct net *net, int how);
 124 extern void             rt_cache_flush_batch(struct net *net);
 125 extern struct rtable *__ip_route_output_key(struct net *, const struct flowi *flp);
 126 extern struct rtable *ip_route_output_flow(struct net *, struct flowi *flp,
 127                                            struct sock *sk);
 128 extern struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig);
 129
 130 static inline struct rtable *ip_route_output_key(struct net *net, struct flowi *flp)
 131 {
 132         return ip_route_output_flow(net, flp, NULL);
 133 }
 134
 135 static inline struct rtable *ip_route_output(struct net *net, __be32 daddr,
 136                                              __be32 saddr, u8 tos, int oif)
 137 {
 138         struct flowi fl = {
 139                 .oif = oif,
 140                 .fl4_dst = daddr,
 141                 .fl4_src = saddr,
 142                 .fl4_tos = tos,
 143         };
 144         return ip_route_output_key(net, &fl);
 145 }
 146
 147 static inline struct rtable *ip_route_output_ports(struct net *net, struct sock *sk,
 148                                                    __be32 daddr, __be32 saddr,
 149                                                    __be16 dport, __be16 sport,
 150                                                    __u8 proto, __u8 tos, int oif)
 151 {
 152         struct flowi fl = {
 153                 .oif = oif,
 154                 .flags = sk ? inet_sk_flowi_flags(sk) : 0,
 155                 .mark = sk ? sk->sk_mark : 0,
 156                 .fl4_dst = daddr,
 157                 .fl4_src = saddr,
 158                 .fl4_tos = tos,
 159                 .proto = proto,
 160                 .fl_ip_dport = dport,
 161                 .fl_ip_sport = sport,
 162         };
 163         if (sk)
 164                 security_sk_classify_flow(sk, &fl);
 165         return ip_route_output_flow(net, &fl, sk);
 166 }
 167
 168 static inline struct rtable *ip_route_output_gre(struct net *net,
 169                                                  __be32 daddr, __be32 saddr,
 170                                                  __be32 gre_key, __u8 tos, int oif)
 171 {
 172         struct flowi fl = {
 173                 .oif = oif,
 174                 .fl4_dst = daddr,
 175                 .fl4_src = saddr,
 176                 .fl4_tos = tos,
 177                 .proto = IPPROTO_GRE,
 178                 .fl_gre_key = gre_key,
 179         };
 180         return ip_route_output_key(net, &fl);
 181 }
 182
 183 extern int ip_route_input_common(struct sk_buff *skb, __be32 dst, __be32 src,
 184                                  u8 tos, struct net_device *devin, bool noref);
 185
 186 static inline int ip_route_input(struct sk_buff *skb, __be32 dst, __be32 src,
 187                                  u8 tos, struct net_device *devin)
 188 {
 189         return ip_route_input_common(skb, dst, src, tos, devin, false);
 190 }
 191
 192 static inline int ip_route_input_noref(struct sk_buff *skb, __be32 dst, __be32 src,
 193                                        u8 tos, struct net_device *devin)
 194 {
 195         return ip_route_input_common(skb, dst, src, tos, devin, true);
 196 }
 197
 198 extern unsigned short   ip_rt_frag_needed(struct net *net, struct iphdr *iph, unsigned short new_mtu, struct net_device *dev);
 199 extern void             ip_rt_send_redirect(struct sk_buff *skb);
 200
 201 extern unsigned         inet_addr_type(struct net *net, __be32 addr);
 202 extern unsigned         inet_dev_addr_type(struct net *net, const struct net_device *dev, __be32 addr);
 203 extern void             ip_rt_multicast_event(struct in_device *);
 204 extern int              ip_rt_ioctl(struct net *, unsigned int cmd, void __user *arg);
 205 extern void             ip_rt_get_source(u8 *src, struct rtable *rt);
 206 extern int              ip_rt_dump(struct sk_buff *skb,  struct netlink_callback *cb);
 207
 208 struct in_ifaddr;
 209 extern void fib_add_ifaddr(struct in_ifaddr *);
 210
 211 static inline void ip_rt_put(struct rtable * rt)
 212 {
 213         if (rt)
 214                 dst_release(&rt->dst);
 215 }
 216
 217 #define IPTOS_RT_MASK   (IPTOS_TOS_MASK & ~3)
 218
 219 extern const __u8 ip_tos2prio[16];
 220
 221 static inline char rt_tos2priority(u8 tos)
 222 {
 223         return ip_tos2prio[IPTOS_TOS(tos)>>1];
 224 }
 225
 226 static inline struct rtable *ip_route_connect(__be32 dst, __be32 src, u32 tos,
 227                                               int oif, u8 protocol,
 228                                               __be16 sport, __be16 dport,
 229                                               struct sock *sk, bool can_sleep)
 230 {
 231         struct flowi fl = { .oif = oif,
 232                             .mark = sk->sk_mark,
 233                             .fl4_dst = dst,
 234                             .fl4_src = src,
 235                             .fl4_tos = tos,
 236                             .proto = protocol,
 237                             .fl_ip_sport = sport,
 238                             .fl_ip_dport = dport };
 239         struct net *net = sock_net(sk);
 240         struct rtable *rt;
 241
 242         if (inet_sk(sk)->transparent)
 243                 fl.flags |= FLOWI_FLAG_ANYSRC;
 244         if (protocol == IPPROTO_TCP)
 245                 fl.flags |= FLOWI_FLAG_PRECOW_METRICS;
 246         if (can_sleep)
 247                 fl.flags |= FLOWI_FLAG_CAN_SLEEP;
 248
 249         if (!dst || !src) {
 250                 rt = __ip_route_output_key(net, &fl);
 251                 if (IS_ERR(rt))
 252                         return rt;
 253                 fl.fl4_dst = rt->rt_dst;
 254                 fl.fl4_src = rt->rt_src;
 255                 ip_rt_put(rt);
 256         }
 257         security_sk_classify_flow(sk, &fl);
 258         return ip_route_output_flow(net, &fl, sk);
 259 }
 260
 261 static inline struct rtable *ip_route_newports(struct rtable *rt,
 262                                                u8 protocol, __be16 orig_sport,
 263                                                __be16 orig_dport, __be16 sport,
 264                                                __be16 dport, struct sock *sk)
 265 {
 266         if (sport != orig_sport || dport != orig_dport) {
 267                 struct flowi fl = { .oif = rt->rt_oif,
 268                                     .mark = rt->rt_mark,
 269                                     .fl4_dst = rt->rt_key_dst,
 270                                     .fl4_src = rt->rt_key_src,
 271                                     .fl4_tos = rt->rt_tos,
 272                                     .proto = protocol,
 273                                     .fl_ip_sport = sport,
 274                                     .fl_ip_dport = dport };
 275
 276                 if (inet_sk(sk)->transparent)
 277                         fl.flags |= FLOWI_FLAG_ANYSRC;
 278                 if (protocol == IPPROTO_TCP)
 279                         fl.flags |= FLOWI_FLAG_PRECOW_METRICS;
 280                 ip_rt_put(rt);
 281                 security_sk_classify_flow(sk, &fl);
 282                 return ip_route_output_flow(sock_net(sk), &fl, sk);
 283         }
 284         return rt;
 285 }
 286
 287 extern void rt_bind_peer(struct rtable *rt, int create);
 288
 289 static inline struct inet_peer *rt_get_peer(struct rtable *rt)
 290 {
 291         if (rt->peer)
 292                 return rt->peer;
 293
 294         rt_bind_peer(rt, 0);
 295         return rt->peer;
 296 }
 297
 298 static inline int inet_iif(const struct sk_buff *skb)
 299 {
 300         return skb_rtable(skb)->rt_iif;
 301 }
 302
 303 extern int sysctl_ip_default_ttl;
 304
 305 static inline int ip4_dst_hoplimit(const struct dst_entry *dst)
 306 {
 307         int hoplimit = dst_metric_raw(dst, RTAX_HOPLIMIT);
 308
 309         if (hoplimit == 0)
 310                 hoplimit = sysctl_ip_default_ttl;
 311         return hoplimit;
 312 }
 313
 314 #endif  /* _ROUTE_H */