include/net/ip_fib.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 Forwarding Information Base.
   7  *
   8  * Authors:     A.N.Kuznetsov, <kuznet@ms2.inr.ac.ru>
   9  *
  10  *              This program is free software; you can redistribute it and/or
  11  *              modify it under the terms of the GNU General Public License
  12  *              as published by the Free Software Foundation; either version
  13  *              2 of the License, or (at your option) any later version.
  14  */
  15
  16 #ifndef _NET_IP_FIB_H
  17 #define _NET_IP_FIB_H
  18
  19 #include <linux/config.h>
  20 #include <net/flow.h>
  21 #include <linux/seq_file.h>
  22
  23 /* WARNING: The ordering of these elements must match ordering
  24  *          of RTA_* rtnetlink attribute numbers.
  25  */
  26 struct kern_rta {
  27         void            *rta_dst;
  28         void            *rta_src;
  29         int             *rta_iif;
  30         int             *rta_oif;
  31         void            *rta_gw;
  32         u32             *rta_priority;
  33         void            *rta_prefsrc;
  34         struct rtattr   *rta_mx;
  35         struct rtattr   *rta_mp;
  36         unsigned char   *rta_protoinfo;
  37         u32             *rta_flow;
  38         struct rta_cacheinfo *rta_ci;
  39         struct rta_session *rta_sess;
  40 };
  41
  42 struct fib_info;
  43
  44 struct fib_nh {
  45         struct net_device       *nh_dev;
  46         struct hlist_node       nh_hash;
  47         struct fib_info         *nh_parent;
  48         unsigned                nh_flags;
  49         unsigned char           nh_scope;
  50 #ifdef CONFIG_IP_ROUTE_MULTIPATH
  51         int                     nh_weight;
  52         int                     nh_power;
  53 #endif
  54 #ifdef CONFIG_NET_CLS_ROUTE
  55         __u32                   nh_tclassid;
  56 #endif
  57         int                     nh_oif;
  58         u32                     nh_gw;
  59 };
  60
  61 /*
  62  * This structure contains data shared by many of routes.
  63  */
  64
  65 struct fib_info {
  66         struct hlist_node       fib_hash;
  67         struct hlist_node       fib_lhash;
  68         int                     fib_treeref;
  69         atomic_t                fib_clntref;
  70         int                     fib_dead;
  71         unsigned                fib_flags;
  72         int                     fib_protocol;
  73         u32                     fib_prefsrc;
  74         u32                     fib_priority;
  75         u32                     fib_metrics[RTAX_MAX];
  76 #define fib_mtu fib_metrics[RTAX_MTU-1]
  77 #define fib_window fib_metrics[RTAX_WINDOW-1]
  78 #define fib_rtt fib_metrics[RTAX_RTT-1]
  79 #define fib_advmss fib_metrics[RTAX_ADVMSS-1]
  80         int                     fib_nhs;
  81 #ifdef CONFIG_IP_ROUTE_MULTIPATH
  82         int                     fib_power;
  83 #endif
  84         struct fib_nh           fib_nh[0];
  85 #define fib_dev         fib_nh[0].nh_dev
  86 };
  87
  88
  89 #ifdef CONFIG_IP_MULTIPLE_TABLES
  90 struct fib_rule;
  91 #endif
  92
  93 struct fib_result {
  94         unsigned char   prefixlen;
  95         unsigned char   nh_sel;
  96         unsigned char   type;
  97         unsigned char   scope;
  98         struct fib_info *fi;
  99 #ifdef CONFIG_IP_MULTIPLE_TABLES
 100         struct fib_rule *r;
 101 #endif
 102 };
 103
 104
 105 #ifdef CONFIG_IP_ROUTE_MULTIPATH
 106
 107 #define FIB_RES_NH(res)         ((res).fi->fib_nh[(res).nh_sel])
 108 #define FIB_RES_RESET(res)      ((res).nh_sel = 0)
 109
 110 #else /* CONFIG_IP_ROUTE_MULTIPATH */
 111
 112 #define FIB_RES_NH(res)         ((res).fi->fib_nh[0])
 113 #define FIB_RES_RESET(res)
 114
 115 #endif /* CONFIG_IP_ROUTE_MULTIPATH */
 116
 117 #define FIB_RES_PREFSRC(res)            ((res).fi->fib_prefsrc ? : __fib_res_prefsrc(&res))
 118 #define FIB_RES_GW(res)                 (FIB_RES_NH(res).nh_gw)
 119 #define FIB_RES_DEV(res)                (FIB_RES_NH(res).nh_dev)
 120 #define FIB_RES_OIF(res)                (FIB_RES_NH(res).nh_oif)
 121
 122 struct fib_table {
 123         unsigned char   tb_id;
 124         unsigned        tb_stamp;
 125         int             (*tb_lookup)(struct fib_table *tb, const struct flowi *flp, struct fib_result *res);
 126         int             (*tb_insert)(struct fib_table *table, struct rtmsg *r,
 127                                      struct kern_rta *rta, struct nlmsghdr *n,
 128                                      struct netlink_skb_parms *req);
 129         int             (*tb_delete)(struct fib_table *table, struct rtmsg *r,
 130                                      struct kern_rta *rta, struct nlmsghdr *n,
 131                                      struct netlink_skb_parms *req);
 132         int             (*tb_dump)(struct fib_table *table, struct sk_buff *skb,
 133                                      struct netlink_callback *cb);
 134         int             (*tb_flush)(struct fib_table *table);
 135         void            (*tb_select_default)(struct fib_table *table,
 136                                              const struct flowi *flp, struct fib_result *res);
 137
 138         unsigned char   tb_data[0];
 139 };
 140
 141 #ifndef CONFIG_IP_MULTIPLE_TABLES
 142
 143 extern struct fib_table *ip_fib_local_table;
 144 extern struct fib_table *ip_fib_main_table;
 145
 146 static inline struct fib_table *fib_get_table(int id)
 147 {
 148         if (id != RT_TABLE_LOCAL)
 149                 return ip_fib_main_table;
 150         return ip_fib_local_table;
 151 }
 152
 153 static inline struct fib_table *fib_new_table(int id)
 154 {
 155         return fib_get_table(id);
 156 }
 157
 158 static inline int fib_lookup(const struct flowi *flp, struct fib_result *res)
 159 {
 160         if (ip_fib_local_table->tb_lookup(ip_fib_local_table, flp, res) &&
 161             ip_fib_main_table->tb_lookup(ip_fib_main_table, flp, res))
 162                 return -ENETUNREACH;
 163         return 0;
 164 }
 165
 166 static inline void fib_select_default(const struct flowi *flp, struct fib_result *res)
 167 {
 168         if (FIB_RES_GW(*res) && FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
 169                 ip_fib_main_table->tb_select_default(ip_fib_main_table, flp, res);
 170 }
 171
 172 #else /* CONFIG_IP_MULTIPLE_TABLES */
 173 #define ip_fib_local_table (fib_tables[RT_TABLE_LOCAL])
 174 #define ip_fib_main_table (fib_tables[RT_TABLE_MAIN])
 175
 176 extern struct fib_table * fib_tables[RT_TABLE_MAX+1];
 177 extern int fib_lookup(const struct flowi *flp, struct fib_result *res);
 178 extern struct fib_table *__fib_new_table(int id);
 179 extern void fib_rule_put(struct fib_rule *r);
 180
 181 static inline struct fib_table *fib_get_table(int id)
 182 {
 183         if (id == 0)
 184                 id = RT_TABLE_MAIN;
 185
 186         return fib_tables[id];
 187 }
 188
 189 static inline struct fib_table *fib_new_table(int id)
 190 {
 191         if (id == 0)
 192                 id = RT_TABLE_MAIN;
 193
 194         return fib_tables[id] ? : __fib_new_table(id);
 195 }
 196
 197 extern void fib_select_default(const struct flowi *flp, struct fib_result *res);
 198
 199 #endif /* CONFIG_IP_MULTIPLE_TABLES */
 200
 201 /* Exported by fib_frontend.c */
 202 extern void             ip_fib_init(void);
 203 extern void             fib_flush(void);
 204 extern int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg);
 205 extern int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg);
 206 extern int inet_rtm_getroute(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg);
 207 extern int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb);
 208 extern int fib_validate_source(u32 src, u32 dst, u8 tos, int oif,
 209                                struct net_device *dev, u32 *spec_dst, u32 *itag);
 210 extern void fib_select_multipath(const struct flowi *flp, struct fib_result *res);
 211
 212 /* Exported by fib_semantics.c */
 213 extern int ip_fib_check_default(u32 gw, struct net_device *dev);
 214 extern int fib_sync_down(u32 local, struct net_device *dev, int force);
 215 extern int fib_sync_up(struct net_device *dev);
 216 extern int fib_convert_rtentry(int cmd, struct nlmsghdr *nl, struct rtmsg *rtm,
 217                                struct kern_rta *rta, struct rtentry *r);
 218 extern u32  __fib_res_prefsrc(struct fib_result *res);
 219
 220 /* Exported by fib_hash.c */
 221 extern struct fib_table *fib_hash_init(int id);
 222
 223 #ifdef CONFIG_IP_MULTIPLE_TABLES
 224 /* Exported by fib_rules.c */
 225
 226 extern int inet_rtm_delrule(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg);
 227 extern int inet_rtm_newrule(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg);
 228 extern int inet_dump_rules(struct sk_buff *skb, struct netlink_callback *cb);
 229 extern u32 fib_rules_map_destination(u32 daddr, struct fib_result *res);
 230 #ifdef CONFIG_NET_CLS_ROUTE
 231 extern u32 fib_rules_tclass(struct fib_result *res);
 232 #endif
 233 extern void fib_rules_init(void);
 234 #endif
 235
 236 static inline void fib_combine_itag(u32 *itag, struct fib_result *res)
 237 {
 238 #ifdef CONFIG_NET_CLS_ROUTE
 239 #ifdef CONFIG_IP_MULTIPLE_TABLES
 240         u32 rtag;
 241 #endif
 242         *itag = FIB_RES_NH(*res).nh_tclassid<<16;
 243 #ifdef CONFIG_IP_MULTIPLE_TABLES
 244         rtag = fib_rules_tclass(res);
 245         if (*itag == 0)
 246                 *itag = (rtag<<16);
 247         *itag |= (rtag>>16);
 248 #endif
 249 #endif
 250 }
 251
 252 extern void free_fib_info(struct fib_info *fi);
 253
 254 static inline void fib_info_put(struct fib_info *fi)
 255 {
 256         if (atomic_dec_and_test(&fi->fib_clntref))
 257                 free_fib_info(fi);
 258 }
 259
 260 static inline void fib_res_put(struct fib_result *res)
 261 {
 262         if (res->fi)
 263                 fib_info_put(res->fi);
 264 #ifdef CONFIG_IP_MULTIPLE_TABLES
 265         if (res->r)
 266                 fib_rule_put(res->r);
 267 #endif
 268 }
 269
 270 #endif  /* _NET_FIB_H */