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         u32             *rta_mp_alg;
  41 };
  42
  43 struct fib_info;
  44
  45 struct fib_nh {
  46         struct net_device       *nh_dev;
  47         struct hlist_node       nh_hash;
  48         struct fib_info         *nh_parent;
  49         unsigned                nh_flags;
  50         unsigned char           nh_scope;
  51 #ifdef CONFIG_IP_ROUTE_MULTIPATH
  52         int                     nh_weight;
  53         int                     nh_power;
  54 #endif
  55 #ifdef CONFIG_NET_CLS_ROUTE
  56         __u32                   nh_tclassid;
  57 #endif
  58         int                     nh_oif;
  59         u32                     nh_gw;
  60 };
  61
  62 /*
  63  * This structure contains data shared by many of routes.
  64  */
  65
  66 struct fib_info {
  67         struct hlist_node       fib_hash;
  68         struct hlist_node       fib_lhash;
  69         int                     fib_treeref;
  70         atomic_t                fib_clntref;
  71         int                     fib_dead;
  72         unsigned                fib_flags;
  73         int                     fib_protocol;
  74         u32                     fib_prefsrc;
  75         u32                     fib_priority;
  76         u32                     fib_metrics[RTAX_MAX];
  77 #define fib_mtu fib_metrics[RTAX_MTU-1]
  78 #define fib_window fib_metrics[RTAX_WINDOW-1]
  79 #define fib_rtt fib_metrics[RTAX_RTT-1]
  80 #define fib_advmss fib_metrics[RTAX_ADVMSS-1]
  81         int                     fib_nhs;
  82 #ifdef CONFIG_IP_ROUTE_MULTIPATH
  83         int                     fib_power;
  84 #endif
  85 #ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
  86         u32                     fib_mp_alg;
  87 #endif
  88         struct fib_nh           fib_nh[0];
  89 #define fib_dev         fib_nh[0].nh_dev
  90 };
  91
  92
  93 #ifdef CONFIG_IP_MULTIPLE_TABLES
  94 struct fib_rule;
  95 #endif
  96
  97 struct fib_result {
  98         unsigned char   prefixlen;
  99         unsigned char   nh_sel;
 100         unsigned char   type;
 101         unsigned char   scope;
 102 #ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
 103         __u32           network;
 104         __u32           netmask;
 105 #endif
 106         struct fib_info *fi;
 107 #ifdef CONFIG_IP_MULTIPLE_TABLES
 108         struct fib_rule *r;
 109 #endif
 110 };
 111
 112
 113 #ifdef CONFIG_IP_ROUTE_MULTIPATH
 114
 115 #define FIB_RES_NH(res)         ((res).fi->fib_nh[(res).nh_sel])
 116 #define FIB_RES_RESET(res)      ((res).nh_sel = 0)
 117
 118 #else /* CONFIG_IP_ROUTE_MULTIPATH */
 119
 120 #define FIB_RES_NH(res)         ((res).fi->fib_nh[0])
 121 #define FIB_RES_RESET(res)
 122
 123 #endif /* CONFIG_IP_ROUTE_MULTIPATH */
 124
 125 #define FIB_RES_PREFSRC(res)            ((res).fi->fib_prefsrc ? : __fib_res_prefsrc(&res))
 126 #define FIB_RES_GW(res)                 (FIB_RES_NH(res).nh_gw)
 127 #define FIB_RES_DEV(res)                (FIB_RES_NH(res).nh_dev)
 128 #define FIB_RES_OIF(res)                (FIB_RES_NH(res).nh_oif)
 129
 130 #ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
 131 #define FIB_RES_NETWORK(res)            ((res).network)
 132 #define FIB_RES_NETMASK(res)            ((res).netmask)
 133 #else /* CONFIG_IP_ROUTE_MULTIPATH_CACHED */
 134 #define FIB_RES_NETWORK(res)            (0)
 135 #define FIB_RES_NETMASK(res)            (0)
 136 #endif /* CONFIG_IP_ROUTE_MULTIPATH_WRANDOM */
 137
 138 struct fib_table {
 139         unsigned char   tb_id;
 140         unsigned        tb_stamp;
 141         int             (*tb_lookup)(struct fib_table *tb, const struct flowi *flp, struct fib_result *res);
 142         int             (*tb_insert)(struct fib_table *table, struct rtmsg *r,
 143                                      struct kern_rta *rta, struct nlmsghdr *n,
 144                                      struct netlink_skb_parms *req);
 145         int             (*tb_delete)(struct fib_table *table, struct rtmsg *r,
 146                                      struct kern_rta *rta, struct nlmsghdr *n,
 147                                      struct netlink_skb_parms *req);
 148         int             (*tb_dump)(struct fib_table *table, struct sk_buff *skb,
 149                                      struct netlink_callback *cb);
 150         int             (*tb_flush)(struct fib_table *table);
 151         void            (*tb_select_default)(struct fib_table *table,
 152                                              const struct flowi *flp, struct fib_result *res);
 153
 154         unsigned char   tb_data[0];
 155 };
 156
 157 #ifndef CONFIG_IP_MULTIPLE_TABLES
 158
 159 extern struct fib_table *ip_fib_local_table;
 160 extern struct fib_table *ip_fib_main_table;
 161
 162 static inline struct fib_table *fib_get_table(int id)
 163 {
 164         if (id != RT_TABLE_LOCAL)
 165                 return ip_fib_main_table;
 166         return ip_fib_local_table;
 167 }
 168
 169 static inline struct fib_table *fib_new_table(int id)
 170 {
 171         return fib_get_table(id);
 172 }
 173
 174 static inline int fib_lookup(const struct flowi *flp, struct fib_result *res)
 175 {
 176         if (ip_fib_local_table->tb_lookup(ip_fib_local_table, flp, res) &&
 177             ip_fib_main_table->tb_lookup(ip_fib_main_table, flp, res))
 178                 return -ENETUNREACH;
 179         return 0;
 180 }
 181
 182 static inline void fib_select_default(const struct flowi *flp, struct fib_result *res)
 183 {
 184         if (FIB_RES_GW(*res) && FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
 185                 ip_fib_main_table->tb_select_default(ip_fib_main_table, flp, res);
 186 }
 187
 188 #else /* CONFIG_IP_MULTIPLE_TABLES */
 189 #define ip_fib_local_table (fib_tables[RT_TABLE_LOCAL])
 190 #define ip_fib_main_table (fib_tables[RT_TABLE_MAIN])
 191
 192 extern struct fib_table * fib_tables[RT_TABLE_MAX+1];
 193 extern int fib_lookup(const struct flowi *flp, struct fib_result *res);
 194 extern struct fib_table *__fib_new_table(int id);
 195 extern void fib_rule_put(struct fib_rule *r);
 196
 197 static inline struct fib_table *fib_get_table(int id)
 198 {
 199         if (id == 0)
 200                 id = RT_TABLE_MAIN;
 201
 202         return fib_tables[id];
 203 }
 204
 205 static inline struct fib_table *fib_new_table(int id)
 206 {
 207         if (id == 0)
 208                 id = RT_TABLE_MAIN;
 209
 210         return fib_tables[id] ? : __fib_new_table(id);
 211 }
 212
 213 extern void fib_select_default(const struct flowi *flp, struct fib_result *res);
 214
 215 #endif /* CONFIG_IP_MULTIPLE_TABLES */
 216
 217 /* Exported by fib_frontend.c */
 218 extern void             ip_fib_init(void);
 219 extern int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg);
 220 extern int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg);
 221 extern int inet_rtm_getroute(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg);
 222 extern int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb);
 223 extern int fib_validate_source(u32 src, u32 dst, u8 tos, int oif,
 224                                struct net_device *dev, u32 *spec_dst, u32 *itag);
 225 extern void fib_select_multipath(const struct flowi *flp, struct fib_result *res);
 226
 227 /* Exported by fib_semantics.c */
 228 extern int ip_fib_check_default(u32 gw, struct net_device *dev);
 229 extern int fib_sync_down(u32 local, struct net_device *dev, int force);
 230 extern int fib_sync_up(struct net_device *dev);
 231 extern int fib_convert_rtentry(int cmd, struct nlmsghdr *nl, struct rtmsg *rtm,
 232                                struct kern_rta *rta, struct rtentry *r);
 233 extern u32  __fib_res_prefsrc(struct fib_result *res);
 234
 235 /* Exported by fib_hash.c */
 236 extern struct fib_table *fib_hash_init(int id);
 237
 238 #ifdef CONFIG_IP_MULTIPLE_TABLES
 239 /* Exported by fib_rules.c */
 240
 241 extern int inet_rtm_delrule(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg);
 242 extern int inet_rtm_newrule(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg);
 243 extern int inet_dump_rules(struct sk_buff *skb, struct netlink_callback *cb);
 244 #ifdef CONFIG_NET_CLS_ROUTE
 245 extern u32 fib_rules_tclass(struct fib_result *res);
 246 #endif
 247 extern void fib_rules_init(void);
 248 #endif
 249
 250 static inline void fib_combine_itag(u32 *itag, struct fib_result *res)
 251 {
 252 #ifdef CONFIG_NET_CLS_ROUTE
 253 #ifdef CONFIG_IP_MULTIPLE_TABLES
 254         u32 rtag;
 255 #endif
 256         *itag = FIB_RES_NH(*res).nh_tclassid<<16;
 257 #ifdef CONFIG_IP_MULTIPLE_TABLES
 258         rtag = fib_rules_tclass(res);
 259         if (*itag == 0)
 260                 *itag = (rtag<<16);
 261         *itag |= (rtag>>16);
 262 #endif
 263 #endif
 264 }
 265
 266 extern void free_fib_info(struct fib_info *fi);
 267
 268 static inline void fib_info_put(struct fib_info *fi)
 269 {
 270         if (atomic_dec_and_test(&fi->fib_clntref))
 271                 free_fib_info(fi);
 272 }
 273
 274 static inline void fib_res_put(struct fib_result *res)
 275 {
 276         if (res->fi)
 277                 fib_info_put(res->fi);
 278 #ifdef CONFIG_IP_MULTIPLE_TABLES
 279         if (res->r)
 280                 fib_rule_put(res->r);
 281 #endif
 282 }
 283
 284 #endif  /* _NET_FIB_H */