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