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         /* Cache lookup keys */
  57         struct flowi            fl;
  58
  59         int                     rt_genid;
  60         unsigned                rt_flags;
  61         __u16                   rt_type;
  62
  63         __be32                  rt_dst; /* Path destination     */
  64         __be32                  rt_src; /* Path source          */
  65         int                     rt_iif;
  66
  67         /* Info on neighbour */
  68         __be32                  rt_gateway;
  69
  70         /* Miscellaneous cached information */
  71         __be32                  rt_spec_dst; /* RFC1122 specific destination */
  72         struct inet_peer        *peer; /* long-living peer info */
  73         struct fib_info         *fi; /* for client ref to shared metrics */
  74 };
  75
  76 static inline bool rt_is_input_route(struct rtable *rt)
  77 {
  78         return rt->fl.iif != 0;
  79 }
  80
  81 static inline bool rt_is_output_route(struct rtable *rt)
  82 {
  83         return rt->fl.iif == 0;
  84 }
  85
  86 struct ip_rt_acct {
  87         __u32   o_bytes;
  88         __u32   o_packets;
  89         __u32   i_bytes;
  90         __u32   i_packets;
  91 };
  92
  93 struct rt_cache_stat {
  94         unsigned int in_hit;
  95         unsigned int in_slow_tot;
  96         unsigned int in_slow_mc;
  97         unsigned int in_no_route;
  98         unsigned int in_brd;
  99         unsigned int in_martian_dst;
 100         unsigned int in_martian_src;
 101         unsigned int out_hit;
 102         unsigned int out_slow_tot;
 103         unsigned int out_slow_mc;
 104         unsigned int gc_total;
 105         unsigned int gc_ignored;
 106         unsigned int gc_goal_miss;
 107         unsigned int gc_dst_overflow;
 108         unsigned int in_hlist_search;
 109         unsigned int out_hlist_search;
 110 };
 111
 112 extern struct ip_rt_acct __percpu *ip_rt_acct;
 113
 114 struct in_device;
 115 extern int              ip_rt_init(void);
 116 extern void             ip_rt_redirect(__be32 old_gw, __be32 dst, __be32 new_gw,
 117                                        __be32 src, struct net_device *dev);
 118 extern void             rt_cache_flush(struct net *net, int how);
 119 extern void             rt_cache_flush_batch(struct net *net);
 120 extern int              __ip_route_output_key(struct net *, struct rtable **, const struct flowi *flp);
 121 extern int              ip_route_output_key(struct net *, struct rtable **, struct flowi *flp);
 122 extern int              ip_route_output_flow(struct net *, struct rtable **rp, struct flowi *flp, struct sock *sk, int flags);
 123
 124 extern int ip_route_input_common(struct sk_buff *skb, __be32 dst, __be32 src,
 125                                  u8 tos, struct net_device *devin, bool noref);
 126
 127 static inline int ip_route_input(struct sk_buff *skb, __be32 dst, __be32 src,
 128                                  u8 tos, struct net_device *devin)
 129 {
 130         return ip_route_input_common(skb, dst, src, tos, devin, false);
 131 }
 132
 133 static inline int ip_route_input_noref(struct sk_buff *skb, __be32 dst, __be32 src,
 134                                        u8 tos, struct net_device *devin)
 135 {
 136         return ip_route_input_common(skb, dst, src, tos, devin, true);
 137 }
 138
 139 extern unsigned short   ip_rt_frag_needed(struct net *net, struct iphdr *iph, unsigned short new_mtu, struct net_device *dev);
 140 extern void             ip_rt_send_redirect(struct sk_buff *skb);
 141
 142 extern unsigned         inet_addr_type(struct net *net, __be32 addr);
 143 extern unsigned         inet_dev_addr_type(struct net *net, const struct net_device *dev, __be32 addr);
 144 extern void             ip_rt_multicast_event(struct in_device *);
 145 extern int              ip_rt_ioctl(struct net *, unsigned int cmd, void __user *arg);
 146 extern void             ip_rt_get_source(u8 *src, struct rtable *rt);
 147 extern int              ip_rt_dump(struct sk_buff *skb,  struct netlink_callback *cb);
 148
 149 struct in_ifaddr;
 150 extern void fib_add_ifaddr(struct in_ifaddr *);
 151
 152 static inline void ip_rt_put(struct rtable * rt)
 153 {
 154         if (rt)
 155                 dst_release(&rt->dst);
 156 }
 157
 158 #define IPTOS_RT_MASK   (IPTOS_TOS_MASK & ~3)
 159
 160 extern const __u8 ip_tos2prio[16];
 161
 162 static inline char rt_tos2priority(u8 tos)
 163 {
 164         return ip_tos2prio[IPTOS_TOS(tos)>>1];
 165 }
 166
 167 static inline int ip_route_connect(struct rtable **rp, __be32 dst,
 168                                    __be32 src, u32 tos, int oif, u8 protocol,
 169                                    __be16 sport, __be16 dport, struct sock *sk,
 170                                    int flags)
 171 {
 172         struct flowi fl = { .oif = oif,
 173                             .mark = sk->sk_mark,
 174                             .fl4_dst = dst,
 175                             .fl4_src = src,
 176                             .fl4_tos = tos,
 177                             .proto = protocol,
 178                             .fl_ip_sport = sport,
 179                             .fl_ip_dport = dport };
 180         int err;
 181         struct net *net = sock_net(sk);
 182
 183         if (inet_sk(sk)->transparent)
 184                 fl.flags |= FLOWI_FLAG_ANYSRC;
 185         if (protocol == IPPROTO_TCP)
 186                 fl.flags |= FLOWI_FLAG_PRECOW_METRICS;
 187
 188         if (!dst || !src) {
 189                 err = __ip_route_output_key(net, rp, &fl);
 190                 if (err)
 191                         return err;
 192                 fl.fl4_dst = (*rp)->rt_dst;
 193                 fl.fl4_src = (*rp)->rt_src;
 194                 ip_rt_put(*rp);
 195                 *rp = NULL;
 196         }
 197         security_sk_classify_flow(sk, &fl);
 198         return ip_route_output_flow(net, rp, &fl, sk, flags);
 199 }
 200
 201 static inline int ip_route_newports(struct rtable **rp, u8 protocol,
 202                                     __be16 sport, __be16 dport, struct sock *sk)
 203 {
 204         if (sport != (*rp)->fl.fl_ip_sport ||
 205             dport != (*rp)->fl.fl_ip_dport) {
 206                 struct flowi fl;
 207
 208                 memcpy(&fl, &(*rp)->fl, sizeof(fl));
 209                 fl.fl_ip_sport = sport;
 210                 fl.fl_ip_dport = dport;
 211                 fl.proto = protocol;
 212                 if (inet_sk(sk)->transparent)
 213                         fl.flags |= FLOWI_FLAG_ANYSRC;
 214                 if (protocol == IPPROTO_TCP)
 215                         fl.flags |= FLOWI_FLAG_PRECOW_METRICS;
 216                 ip_rt_put(*rp);
 217                 *rp = NULL;
 218                 security_sk_classify_flow(sk, &fl);
 219                 return ip_route_output_flow(sock_net(sk), rp, &fl, sk, 0);
 220         }
 221         return 0;
 222 }
 223
 224 extern void rt_bind_peer(struct rtable *rt, int create);
 225
 226 static inline struct inet_peer *rt_get_peer(struct rtable *rt)
 227 {
 228         if (rt->peer)
 229                 return rt->peer;
 230
 231         rt_bind_peer(rt, 0);
 232         return rt->peer;
 233 }
 234
 235 static inline int inet_iif(const struct sk_buff *skb)
 236 {
 237         return skb_rtable(skb)->rt_iif;
 238 }
 239
 240 extern int sysctl_ip_default_ttl;
 241
 242 static inline int ip4_dst_hoplimit(const struct dst_entry *dst)
 243 {
 244         int hoplimit = dst_metric_raw(dst, RTAX_HOPLIMIT);
 245
 246         if (hoplimit == 0)
 247                 hoplimit = sysctl_ip_default_ttl;
 248         return hoplimit;
 249 }
 250
 251 #endif  /* _ROUTE_H */