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 struct rtable *__ip_route_output_key(struct net *, const struct flowi *flp);
 122 extern struct rtable *ip_route_output_key(struct net *, struct flowi *flp);
 123 extern struct rtable *ip_route_output_flow(struct net *, struct flowi *flp,
 124                                            struct sock *sk);
 125 extern struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig);
 126
 127 extern int ip_route_input_common(struct sk_buff *skb, __be32 dst, __be32 src,
 128                                  u8 tos, struct net_device *devin, bool noref);
 129
 130 static inline int ip_route_input(struct sk_buff *skb, __be32 dst, __be32 src,
 131                                  u8 tos, struct net_device *devin)
 132 {
 133         return ip_route_input_common(skb, dst, src, tos, devin, false);
 134 }
 135
 136 static inline int ip_route_input_noref(struct sk_buff *skb, __be32 dst, __be32 src,
 137                                        u8 tos, struct net_device *devin)
 138 {
 139         return ip_route_input_common(skb, dst, src, tos, devin, true);
 140 }
 141
 142 extern unsigned short   ip_rt_frag_needed(struct net *net, struct iphdr *iph, unsigned short new_mtu, struct net_device *dev);
 143 extern void             ip_rt_send_redirect(struct sk_buff *skb);
 144
 145 extern unsigned         inet_addr_type(struct net *net, __be32 addr);
 146 extern unsigned         inet_dev_addr_type(struct net *net, const struct net_device *dev, __be32 addr);
 147 extern void             ip_rt_multicast_event(struct in_device *);
 148 extern int              ip_rt_ioctl(struct net *, unsigned int cmd, void __user *arg);
 149 extern void             ip_rt_get_source(u8 *src, struct rtable *rt);
 150 extern int              ip_rt_dump(struct sk_buff *skb,  struct netlink_callback *cb);
 151
 152 struct in_ifaddr;
 153 extern void fib_add_ifaddr(struct in_ifaddr *);
 154
 155 static inline void ip_rt_put(struct rtable * rt)
 156 {
 157         if (rt)
 158                 dst_release(&rt->dst);
 159 }
 160
 161 #define IPTOS_RT_MASK   (IPTOS_TOS_MASK & ~3)
 162
 163 extern const __u8 ip_tos2prio[16];
 164
 165 static inline char rt_tos2priority(u8 tos)
 166 {
 167         return ip_tos2prio[IPTOS_TOS(tos)>>1];
 168 }
 169
 170 static inline struct rtable *ip_route_connect(__be32 dst, __be32 src, u32 tos,
 171                                               int oif, u8 protocol,
 172                                               __be16 sport, __be16 dport,
 173                                               struct sock *sk, bool can_sleep)
 174 {
 175         struct flowi fl = { .oif = oif,
 176                             .mark = sk->sk_mark,
 177                             .fl4_dst = dst,
 178                             .fl4_src = src,
 179                             .fl4_tos = tos,
 180                             .proto = protocol,
 181                             .fl_ip_sport = sport,
 182                             .fl_ip_dport = dport };
 183         struct net *net = sock_net(sk);
 184         struct rtable *rt;
 185
 186         if (inet_sk(sk)->transparent)
 187                 fl.flags |= FLOWI_FLAG_ANYSRC;
 188         if (protocol == IPPROTO_TCP)
 189                 fl.flags |= FLOWI_FLAG_PRECOW_METRICS;
 190         if (can_sleep)
 191                 fl.flags |= FLOWI_FLAG_CAN_SLEEP;
 192
 193         if (!dst || !src) {
 194                 rt = __ip_route_output_key(net, &fl);
 195                 if (IS_ERR(rt))
 196                         return rt;
 197                 fl.fl4_dst = rt->rt_dst;
 198                 fl.fl4_src = rt->rt_src;
 199                 ip_rt_put(rt);
 200         }
 201         security_sk_classify_flow(sk, &fl);
 202         return ip_route_output_flow(net, &fl, sk);
 203 }
 204
 205 static inline struct rtable *ip_route_newports(struct rtable *rt,
 206                                                u8 protocol, __be16 orig_sport,
 207                                                __be16 orig_dport, __be16 sport,
 208                                                __be16 dport, struct sock *sk)
 209 {
 210         if (sport != orig_sport || dport != orig_dport) {
 211                 struct flowi fl = { .oif = rt->fl.oif,
 212                                     .mark = rt->fl.mark,
 213                                     .fl4_dst = rt->fl.fl4_dst,
 214                                     .fl4_src = rt->fl.fl4_src,
 215                                     .fl4_tos = rt->fl.fl4_tos,
 216                                     .proto = rt->fl.proto,
 217                                     .fl_ip_sport = sport,
 218                                     .fl_ip_dport = dport };
 219
 220                 if (inet_sk(sk)->transparent)
 221                         fl.flags |= FLOWI_FLAG_ANYSRC;
 222                 if (protocol == IPPROTO_TCP)
 223                         fl.flags |= FLOWI_FLAG_PRECOW_METRICS;
 224                 ip_rt_put(rt);
 225                 security_sk_classify_flow(sk, &fl);
 226                 return ip_route_output_flow(sock_net(sk), &fl, sk);
 227         }
 228         return rt;
 229 }
 230
 231 extern void rt_bind_peer(struct rtable *rt, int create);
 232
 233 static inline struct inet_peer *rt_get_peer(struct rtable *rt)
 234 {
 235         if (rt->peer)
 236                 return rt->peer;
 237
 238         rt_bind_peer(rt, 0);
 239         return rt->peer;
 240 }
 241
 242 static inline int inet_iif(const struct sk_buff *skb)
 243 {
 244         return skb_rtable(skb)->rt_iif;
 245 }
 246
 247 extern int sysctl_ip_default_ttl;
 248
 249 static inline int ip4_dst_hoplimit(const struct dst_entry *dst)
 250 {
 251         int hoplimit = dst_metric_raw(dst, RTAX_HOPLIMIT);
 252
 253         if (hoplimit == 0)
 254                 hoplimit = sysctl_ip_default_ttl;
 255         return hoplimit;
 256 }
 257
 258 #endif  /* _ROUTE_H */