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