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 <linux/config.h>
  28 #include <net/dst.h>
  29 #include <net/inetpeer.h>
  30 #include <net/flow.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
  37 #ifndef __KERNEL__
  38 #warning This file is not supposed to be used outside of kernel.
  39 #endif
  40
  41 #define RTO_ONLINK      0x01
  42
  43 #define RTO_CONN        0
  44 /* RTO_CONN is not used (being alias for 0), but preserved not to break
  45  * some modules referring to it. */
  46
  47 #define RT_CONN_FLAGS(sk)   (RT_TOS(inet_sk(sk)->tos) | sock_flag(sk, SOCK_LOCALROUTE))
  48
  49 struct fib_nh;
  50 struct inet_peer;
  51 struct rtable
  52 {
  53         union
  54         {
  55                 struct dst_entry        dst;
  56                 struct rtable           *rt_next;
  57         } u;
  58
  59         struct in_device        *idev;
  60
  61         unsigned                rt_flags;
  62         __u16                   rt_type;
  63         __u16                   rt_multipath_alg;
  64
  65         __u32                   rt_dst; /* Path destination     */
  66         __u32                   rt_src; /* Path source          */
  67         int                     rt_iif;
  68
  69         /* Info on neighbour */
  70         __u32                   rt_gateway;
  71
  72         /* Cache lookup keys */
  73         struct flowi            fl;
  74
  75         /* Miscellaneous cached information */
  76         __u32                   rt_spec_dst; /* RFC1122 specific destination */
  77         struct inet_peer        *peer; /* long-living peer info */
  78 };
  79
  80 struct ip_rt_acct
  81 {
  82         __u32   o_bytes;
  83         __u32   o_packets;
  84         __u32   i_bytes;
  85         __u32   i_packets;
  86 };
  87
  88 struct rt_cache_stat
  89 {
  90         unsigned int in_hit;
  91         unsigned int in_slow_tot;
  92         unsigned int in_slow_mc;
  93         unsigned int in_no_route;
  94         unsigned int in_brd;
  95         unsigned int in_martian_dst;
  96         unsigned int in_martian_src;
  97         unsigned int out_hit;
  98         unsigned int out_slow_tot;
  99         unsigned int out_slow_mc;
 100         unsigned int gc_total;
 101         unsigned int gc_ignored;
 102         unsigned int gc_goal_miss;
 103         unsigned int gc_dst_overflow;
 104         unsigned int in_hlist_search;
 105         unsigned int out_hlist_search;
 106 };
 107
 108 extern struct rt_cache_stat *rt_cache_stat;
 109 #define RT_CACHE_STAT_INC(field)                                          \
 110                 (per_cpu_ptr(rt_cache_stat, raw_smp_processor_id())->field++)
 111
 112 extern struct ip_rt_acct *ip_rt_acct;
 113
 114 struct in_device;
 115 extern int              ip_rt_init(void);
 116 extern void             ip_rt_redirect(u32 old_gw, u32 dst, u32 new_gw,
 117                                        u32 src, u8 tos, struct net_device *dev);
 118 extern void             ip_rt_advice(struct rtable **rp, int advice);
 119 extern void             rt_cache_flush(int how);
 120 extern int              __ip_route_output_key(struct rtable **, const struct flowi *flp);
 121 extern int              ip_route_output_key(struct rtable **, struct flowi *flp);
 122 extern int              ip_route_output_flow(struct rtable **rp, struct flowi *flp, struct sock *sk, int flags);
 123 extern int              ip_route_input(struct sk_buff*, u32 dst, u32 src, u8 tos, struct net_device *devin);
 124 extern unsigned short   ip_rt_frag_needed(struct iphdr *iph, unsigned short new_mtu);
 125 extern void             ip_rt_send_redirect(struct sk_buff *skb);
 126
 127 extern unsigned         inet_addr_type(u32 addr);
 128 extern void             ip_rt_multicast_event(struct in_device *);
 129 extern int              ip_rt_ioctl(unsigned int cmd, void __user *arg);
 130 extern void             ip_rt_get_source(u8 *src, struct rtable *rt);
 131 extern int              ip_rt_dump(struct sk_buff *skb,  struct netlink_callback *cb);
 132
 133 static inline void ip_rt_put(struct rtable * rt)
 134 {
 135         if (rt)
 136                 dst_release(&rt->u.dst);
 137 }
 138
 139 #define IPTOS_RT_MASK   (IPTOS_TOS_MASK & ~3)
 140
 141 extern __u8 ip_tos2prio[16];
 142
 143 static inline char rt_tos2priority(u8 tos)
 144 {
 145         return ip_tos2prio[IPTOS_TOS(tos)>>1];
 146 }
 147
 148 static inline int ip_route_connect(struct rtable **rp, u32 dst,
 149                                    u32 src, u32 tos, int oif, u8 protocol,
 150                                    u16 sport, u16 dport, struct sock *sk)
 151 {
 152         struct flowi fl = { .oif = oif,
 153                             .nl_u = { .ip4_u = { .daddr = dst,
 154                                                  .saddr = src,
 155                                                  .tos   = tos } },
 156                             .proto = protocol,
 157                             .uli_u = { .ports =
 158                                        { .sport = sport,
 159                                          .dport = dport } } };
 160
 161         int err;
 162         if (!dst || !src) {
 163                 err = __ip_route_output_key(rp, &fl);
 164                 if (err)
 165                         return err;
 166                 fl.fl4_dst = (*rp)->rt_dst;
 167                 fl.fl4_src = (*rp)->rt_src;
 168                 ip_rt_put(*rp);
 169                 *rp = NULL;
 170         }
 171         return ip_route_output_flow(rp, &fl, sk, 0);
 172 }
 173
 174 static inline int ip_route_newports(struct rtable **rp, u16 sport, u16 dport,
 175                                     struct sock *sk)
 176 {
 177         if (sport != (*rp)->fl.fl_ip_sport ||
 178             dport != (*rp)->fl.fl_ip_dport) {
 179                 struct flowi fl;
 180
 181                 memcpy(&fl, &(*rp)->fl, sizeof(fl));
 182                 fl.fl_ip_sport = sport;
 183                 fl.fl_ip_dport = dport;
 184                 ip_rt_put(*rp);
 185                 *rp = NULL;
 186                 return ip_route_output_flow(rp, &fl, sk, 0);
 187         }
 188         return 0;
 189 }
 190
 191 extern void rt_bind_peer(struct rtable *rt, int create);
 192
 193 static inline struct inet_peer *rt_get_peer(struct rtable *rt)
 194 {
 195         if (rt->peer)
 196                 return rt->peer;
 197
 198         rt_bind_peer(rt, 0);
 199         return rt->peer;
 200 }
 201
 202 #endif  /* _ROUTE_H */