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 rtable {
  53         struct dst_entry        dst;
  54
  55         /* Cache lookup keys */
  56         struct flowi            fl;
  57
  58         struct in_device        *idev;
  59
  60         int                     rt_genid;
  61         unsigned                rt_flags;
  62         __u16                   rt_type;
  63
  64         __be32                  rt_dst; /* Path destination     */
  65         __be32                  rt_src; /* Path source          */
  66         int                     rt_iif;
  67
  68         /* Info on neighbour */
  69         __be32                  rt_gateway;
  70
  71         /* Miscellaneous cached information */
  72         __be32                  rt_spec_dst; /* RFC1122 specific destination */
  73         struct inet_peer        *peer; /* long-living peer info */
  74 };
  75
  76 struct ip_rt_acct {
  77         __u32   o_bytes;
  78         __u32   o_packets;
  79         __u32   i_bytes;
  80         __u32   i_packets;
  81 };
  82
  83 struct rt_cache_stat {
  84         unsigned int in_hit;
  85         unsigned int in_slow_tot;
  86         unsigned int in_slow_mc;
  87         unsigned int in_no_route;
  88         unsigned int in_brd;
  89         unsigned int in_martian_dst;
  90         unsigned int in_martian_src;
  91         unsigned int out_hit;
  92         unsigned int out_slow_tot;
  93         unsigned int out_slow_mc;
  94         unsigned int gc_total;
  95         unsigned int gc_ignored;
  96         unsigned int gc_goal_miss;
  97         unsigned int gc_dst_overflow;
  98         unsigned int in_hlist_search;
  99         unsigned int out_hlist_search;
 100 };
 101
 102 extern struct ip_rt_acct __percpu *ip_rt_acct;
 103
 104 struct in_device;
 105 extern int              ip_rt_init(void);
 106 extern void             ip_rt_redirect(__be32 old_gw, __be32 dst, __be32 new_gw,
 107                                        __be32 src, struct net_device *dev);
 108 extern void             rt_cache_flush(struct net *net, int how);
 109 extern void             rt_cache_flush_batch(void);
 110 extern int              __ip_route_output_key(struct net *, struct rtable **, const struct flowi *flp);
 111 extern int              ip_route_output_key(struct net *, struct rtable **, struct flowi *flp);
 112 extern int              ip_route_output_flow(struct net *, struct rtable **rp, struct flowi *flp, struct sock *sk, int flags);
 113
 114 extern int ip_route_input_common(struct sk_buff *skb, __be32 dst, __be32 src,
 115                                  u8 tos, struct net_device *devin, bool noref);
 116
 117 static inline int ip_route_input(struct sk_buff *skb, __be32 dst, __be32 src,
 118                                  u8 tos, struct net_device *devin)
 119 {
 120         return ip_route_input_common(skb, dst, src, tos, devin, false);
 121 }
 122
 123 static inline int ip_route_input_noref(struct sk_buff *skb, __be32 dst, __be32 src,
 124                                        u8 tos, struct net_device *devin)
 125 {
 126         return ip_route_input_common(skb, dst, src, tos, devin, true);
 127 }
 128
 129 extern unsigned short   ip_rt_frag_needed(struct net *net, struct iphdr *iph, unsigned short new_mtu, struct net_device *dev);
 130 extern void             ip_rt_send_redirect(struct sk_buff *skb);
 131
 132 extern unsigned         inet_addr_type(struct net *net, __be32 addr);
 133 extern unsigned         inet_dev_addr_type(struct net *net, const struct net_device *dev, __be32 addr);
 134 extern void             ip_rt_multicast_event(struct in_device *);
 135 extern int              ip_rt_ioctl(struct net *, unsigned int cmd, void __user *arg);
 136 extern void             ip_rt_get_source(u8 *src, struct rtable *rt);
 137 extern int              ip_rt_dump(struct sk_buff *skb,  struct netlink_callback *cb);
 138
 139 struct in_ifaddr;
 140 extern void fib_add_ifaddr(struct in_ifaddr *);
 141
 142 static inline void ip_rt_put(struct rtable * rt)
 143 {
 144         if (rt)
 145                 dst_release(&rt->dst);
 146 }
 147
 148 #define IPTOS_RT_MASK   (IPTOS_TOS_MASK & ~3)
 149
 150 extern const __u8 ip_tos2prio[16];
 151
 152 static inline char rt_tos2priority(u8 tos)
 153 {
 154         return ip_tos2prio[IPTOS_TOS(tos)>>1];
 155 }
 156
 157 static inline int ip_route_connect(struct rtable **rp, __be32 dst,
 158                                    __be32 src, u32 tos, int oif, u8 protocol,
 159                                    __be16 sport, __be16 dport, struct sock *sk,
 160                                    int flags)
 161 {
 162         struct flowi fl = { .oif = oif,
 163                             .mark = sk->sk_mark,
 164                             .nl_u = { .ip4_u = { .daddr = dst,
 165                                                  .saddr = src,
 166                                                  .tos   = tos } },
 167                             .proto = protocol,
 168                             .uli_u = { .ports =
 169                                        { .sport = sport,
 170                                          .dport = dport } } };
 171
 172         int err;
 173         struct net *net = sock_net(sk);
 174
 175         if (inet_sk(sk)->transparent)
 176                 fl.flags |= FLOWI_FLAG_ANYSRC;
 177
 178         if (!dst || !src) {
 179                 err = __ip_route_output_key(net, rp, &fl);
 180                 if (err)
 181                         return err;
 182                 fl.fl4_dst = (*rp)->rt_dst;
 183                 fl.fl4_src = (*rp)->rt_src;
 184                 ip_rt_put(*rp);
 185                 *rp = NULL;
 186         }
 187         security_sk_classify_flow(sk, &fl);
 188         return ip_route_output_flow(net, rp, &fl, sk, flags);
 189 }
 190
 191 static inline int ip_route_newports(struct rtable **rp, u8 protocol,
 192                                     __be16 sport, __be16 dport, struct sock *sk)
 193 {
 194         if (sport != (*rp)->fl.fl_ip_sport ||
 195             dport != (*rp)->fl.fl_ip_dport) {
 196                 struct flowi fl;
 197
 198                 memcpy(&fl, &(*rp)->fl, sizeof(fl));
 199                 fl.fl_ip_sport = sport;
 200                 fl.fl_ip_dport = dport;
 201                 fl.proto = protocol;
 202                 if (inet_sk(sk)->transparent)
 203                         fl.flags |= FLOWI_FLAG_ANYSRC;
 204                 ip_rt_put(*rp);
 205                 *rp = NULL;
 206                 security_sk_classify_flow(sk, &fl);
 207                 return ip_route_output_flow(sock_net(sk), rp, &fl, sk, 0);
 208         }
 209         return 0;
 210 }
 211
 212 extern void rt_bind_peer(struct rtable *rt, int create);
 213
 214 static inline struct inet_peer *rt_get_peer(struct rtable *rt)
 215 {
 216         if (rt->peer)
 217                 return rt->peer;
 218
 219         rt_bind_peer(rt, 0);
 220         return rt->peer;
 221 }
 222
 223 static inline int inet_iif(const struct sk_buff *skb)
 224 {
 225         return skb_rtable(skb)->rt_iif;
 226 }
 227
 228 #endif  /* _ROUTE_H */