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 <linux/in_route.h>
  31 #include <linux/rtnetlink.h>
  32 #include <linux/route.h>
  33 #include <linux/ip.h>
  34 #include <linux/cache.h>
  35
  36 #ifndef __KERNEL__
  37 #warning This file is not supposed to be used outside of kernel.
  38 #endif
  39
  40 #define RTO_ONLINK      0x01
  41
  42 #define RTO_CONN        0
  43 /* RTO_CONN is not used (being alias for 0), but preserved not to break
  44  * some modules referring to it. */
  45
  46 #define RT_CONN_FLAGS(sk)   (RT_TOS(inet_sk(sk)->tos) | sock_flag(sk, SOCK_LOCALROUTE))
  47
  48 struct fib_nh;
  49 struct inet_peer;
  50 struct rtable
  51 {
  52         union
  53         {
  54                 struct dst_entry        dst;
  55                 struct rtable           *rt_next;
  56         } u;
  57
  58         struct in_device        *idev;
  59
  60         unsigned                rt_flags;
  61         __u16                   rt_type;
  62         __u16                   rt_multipath_alg;
  63
  64         __u32                   rt_dst; /* Path destination     */
  65         __u32                   rt_src; /* Path source          */
  66         int                     rt_iif;
  67
  68         /* Info on neighbour */
  69         __u32                   rt_gateway;
  70
  71         /* Cache lookup keys */
  72         struct flowi            fl;
  73
  74         /* Miscellaneous cached information */
  75         __u32                   rt_spec_dst; /* RFC1122 specific destination */
  76         struct inet_peer        *peer; /* long-living peer info */
  77 };
  78
  79 struct ip_rt_acct
  80 {
  81         __u32   o_bytes;
  82         __u32   o_packets;
  83         __u32   i_bytes;
  84         __u32   i_packets;
  85 };
  86
  87 struct rt_cache_stat
  88 {
  89         unsigned int in_hit;
  90         unsigned int in_slow_tot;
  91         unsigned int in_slow_mc;
  92         unsigned int in_no_route;
  93         unsigned int in_brd;
  94         unsigned int in_martian_dst;
  95         unsigned int in_martian_src;
  96         unsigned int out_hit;
  97         unsigned int out_slow_tot;
  98         unsigned int out_slow_mc;
  99         unsigned int gc_total;
 100         unsigned int gc_ignored;
 101         unsigned int gc_goal_miss;
 102         unsigned int gc_dst_overflow;
 103         unsigned int in_hlist_search;
 104         unsigned int out_hlist_search;
 105 };
 106
 107 extern struct ip_rt_acct *ip_rt_acct;
 108
 109 struct in_device;
 110 extern int              ip_rt_init(void);
 111 extern void             ip_rt_redirect(u32 old_gw, u32 dst, u32 new_gw,
 112                                        u32 src, struct net_device *dev);
 113 extern void             ip_rt_advice(struct rtable **rp, int advice);
 114 extern void             rt_cache_flush(int how);
 115 extern int              __ip_route_output_key(struct rtable **, const struct flowi *flp);
 116 extern int              ip_route_output_key(struct rtable **, struct flowi *flp);
 117 extern int              ip_route_output_flow(struct rtable **rp, struct flowi *flp, struct sock *sk, int flags);
 118 extern int              ip_route_input(struct sk_buff*, u32 dst, u32 src, u8 tos, struct net_device *devin);
 119 extern unsigned short   ip_rt_frag_needed(struct iphdr *iph, unsigned short new_mtu);
 120 extern void             ip_rt_send_redirect(struct sk_buff *skb);
 121
 122 extern unsigned         inet_addr_type(u32 addr);
 123 extern void             ip_rt_multicast_event(struct in_device *);
 124 extern int              ip_rt_ioctl(unsigned int cmd, void __user *arg);
 125 extern void             ip_rt_get_source(u8 *src, struct rtable *rt);
 126 extern int              ip_rt_dump(struct sk_buff *skb,  struct netlink_callback *cb);
 127
 128 struct in_ifaddr;
 129 extern void fib_add_ifaddr(struct in_ifaddr *);
 130
 131 static inline void ip_rt_put(struct rtable * rt)
 132 {
 133         if (rt)
 134                 dst_release(&rt->u.dst);
 135 }
 136
 137 #define IPTOS_RT_MASK   (IPTOS_TOS_MASK & ~3)
 138
 139 extern __u8 ip_tos2prio[16];
 140
 141 static inline char rt_tos2priority(u8 tos)
 142 {
 143         return ip_tos2prio[IPTOS_TOS(tos)>>1];
 144 }
 145
 146 static inline int ip_route_connect(struct rtable **rp, u32 dst,
 147                                    u32 src, u32 tos, int oif, u8 protocol,
 148                                    u16 sport, u16 dport, struct sock *sk)
 149 {
 150         struct flowi fl = { .oif = oif,
 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         if (!dst || !src) {
 161                 err = __ip_route_output_key(rp, &fl);
 162                 if (err)
 163                         return err;
 164                 fl.fl4_dst = (*rp)->rt_dst;
 165                 fl.fl4_src = (*rp)->rt_src;
 166                 ip_rt_put(*rp);
 167                 *rp = NULL;
 168         }
 169         return ip_route_output_flow(rp, &fl, sk, 0);
 170 }
 171
 172 static inline int ip_route_newports(struct rtable **rp, u8 protocol,
 173                                     u16 sport, u16 dport, struct sock *sk)
 174 {
 175         if (sport != (*rp)->fl.fl_ip_sport ||
 176             dport != (*rp)->fl.fl_ip_dport) {
 177                 struct flowi fl;
 178
 179                 memcpy(&fl, &(*rp)->fl, sizeof(fl));
 180                 fl.fl_ip_sport = sport;
 181                 fl.fl_ip_dport = dport;
 182                 fl.proto = protocol;
 183                 ip_rt_put(*rp);
 184                 *rp = NULL;
 185                 return ip_route_output_flow(rp, &fl, sk, 0);
 186         }
 187         return 0;
 188 }
 189
 190 extern void rt_bind_peer(struct rtable *rt, int create);
 191
 192 static inline struct inet_peer *rt_get_peer(struct rtable *rt)
 193 {
 194         if (rt->peer)
 195                 return rt->peer;
 196
 197         rt_bind_peer(rt, 0);
 198         return rt->peer;
 199 }
 200
 201 extern ctl_table ipv4_route_table[];
 202
 203 #endif  /* _ROUTE_H */