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 struct fib_result_nl {
 113         u32             fl_addr;   /* To be looked up*/
 114         u32             fl_fwmark;
 115         unsigned char   fl_tos;
 116         unsigned char   fl_scope;
 117         unsigned char   tb_id_in;
 118
 119         unsigned char   tb_id;      /* Results */
 120         unsigned char   prefixlen;
 121         unsigned char   nh_sel;
 122         unsigned char   type;
 123         unsigned char   scope;
 124         int             err;
 125 };
 126
 127 #ifdef CONFIG_IP_ROUTE_MULTIPATH
 128
 129 #define FIB_RES_NH(res)         ((res).fi->fib_nh[(res).nh_sel])
 130 #define FIB_RES_RESET(res)      ((res).nh_sel = 0)
 131
 132 #else /* CONFIG_IP_ROUTE_MULTIPATH */
 133
 134 #define FIB_RES_NH(res)         ((res).fi->fib_nh[0])
 135 #define FIB_RES_RESET(res)
 136
 137 #endif /* CONFIG_IP_ROUTE_MULTIPATH */
 138
 139 #define FIB_RES_PREFSRC(res)            ((res).fi->fib_prefsrc ? : __fib_res_prefsrc(&res))
 140 #define FIB_RES_GW(res)                 (FIB_RES_NH(res).nh_gw)
 141 #define FIB_RES_DEV(res)                (FIB_RES_NH(res).nh_dev)
 142 #define FIB_RES_OIF(res)                (FIB_RES_NH(res).nh_oif)
 143
 144 #ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
 145 #define FIB_RES_NETWORK(res)            ((res).network)
 146 #define FIB_RES_NETMASK(res)            ((res).netmask)
 147 #else /* CONFIG_IP_ROUTE_MULTIPATH_CACHED */
 148 #define FIB_RES_NETWORK(res)            (0)
 149 #define FIB_RES_NETMASK(res)            (0)
 150 #endif /* CONFIG_IP_ROUTE_MULTIPATH_WRANDOM */
 151
 152 struct fib_table {
 153         unsigned char   tb_id;
 154         unsigned        tb_stamp;
 155         int             (*tb_lookup)(struct fib_table *tb, const struct flowi *flp, struct fib_result *res);
 156         int             (*tb_insert)(struct fib_table *table, struct rtmsg *r,
 157                                      struct kern_rta *rta, struct nlmsghdr *n,
 158                                      struct netlink_skb_parms *req);
 159         int             (*tb_delete)(struct fib_table *table, struct rtmsg *r,
 160                                      struct kern_rta *rta, struct nlmsghdr *n,
 161                                      struct netlink_skb_parms *req);
 162         int             (*tb_dump)(struct fib_table *table, struct sk_buff *skb,
 163                                      struct netlink_callback *cb);
 164         int             (*tb_flush)(struct fib_table *table);
 165         void            (*tb_select_default)(struct fib_table *table,
 166                                              const struct flowi *flp, struct fib_result *res);
 167
 168         unsigned char   tb_data[0];
 169 };
 170
 171 #ifndef CONFIG_IP_MULTIPLE_TABLES
 172
 173 extern struct fib_table *ip_fib_local_table;
 174 extern struct fib_table *ip_fib_main_table;
 175
 176 static inline struct fib_table *fib_get_table(int id)
 177 {
 178         if (id != RT_TABLE_LOCAL)
 179                 return ip_fib_main_table;
 180         return ip_fib_local_table;
 181 }
 182
 183 static inline struct fib_table *fib_new_table(int id)
 184 {
 185         return fib_get_table(id);
 186 }
 187
 188 static inline int fib_lookup(const struct flowi *flp, struct fib_result *res)
 189 {
 190         if (ip_fib_local_table->tb_lookup(ip_fib_local_table, flp, res) &&
 191             ip_fib_main_table->tb_lookup(ip_fib_main_table, flp, res))
 192                 return -ENETUNREACH;
 193         return 0;
 194 }
 195
 196 static inline void fib_select_default(const struct flowi *flp, struct fib_result *res)
 197 {
 198         if (FIB_RES_GW(*res) && FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
 199                 ip_fib_main_table->tb_select_default(ip_fib_main_table, flp, res);
 200 }
 201
 202 #else /* CONFIG_IP_MULTIPLE_TABLES */
 203 #define ip_fib_local_table (fib_tables[RT_TABLE_LOCAL])
 204 #define ip_fib_main_table (fib_tables[RT_TABLE_MAIN])
 205
 206 extern struct fib_table * fib_tables[RT_TABLE_MAX+1];
 207 extern int fib_lookup(const struct flowi *flp, struct fib_result *res);
 208 extern struct fib_table *__fib_new_table(int id);
 209 extern void fib_rule_put(struct fib_rule *r);
 210
 211 static inline struct fib_table *fib_get_table(int id)
 212 {
 213         if (id == 0)
 214                 id = RT_TABLE_MAIN;
 215
 216         return fib_tables[id];
 217 }
 218
 219 static inline struct fib_table *fib_new_table(int id)
 220 {
 221         if (id == 0)
 222                 id = RT_TABLE_MAIN;
 223
 224         return fib_tables[id] ? : __fib_new_table(id);
 225 }
 226
 227 extern void fib_select_default(const struct flowi *flp, struct fib_result *res);
 228
 229 #endif /* CONFIG_IP_MULTIPLE_TABLES */
 230
 231 /* Exported by fib_frontend.c */
 232 extern void             ip_fib_init(void);
 233 extern int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg);
 234 extern int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg);
 235 extern int inet_rtm_getroute(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg);
 236 extern int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb);
 237 extern int fib_validate_source(u32 src, u32 dst, u8 tos, int oif,
 238                                struct net_device *dev, u32 *spec_dst, u32 *itag);
 239 extern void fib_select_multipath(const struct flowi *flp, struct fib_result *res);
 240
 241 /* Exported by fib_semantics.c */
 242 extern int ip_fib_check_default(u32 gw, struct net_device *dev);
 243 extern int fib_sync_down(u32 local, struct net_device *dev, int force);
 244 extern int fib_sync_up(struct net_device *dev);
 245 extern int fib_convert_rtentry(int cmd, struct nlmsghdr *nl, struct rtmsg *rtm,
 246                                struct kern_rta *rta, struct rtentry *r);
 247 extern u32  __fib_res_prefsrc(struct fib_result *res);
 248
 249 /* Exported by fib_hash.c */
 250 extern struct fib_table *fib_hash_init(int id);
 251
 252 #ifdef CONFIG_IP_MULTIPLE_TABLES
 253 /* Exported by fib_rules.c */
 254
 255 extern int inet_rtm_delrule(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg);
 256 extern int inet_rtm_newrule(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg);
 257 extern int inet_dump_rules(struct sk_buff *skb, struct netlink_callback *cb);
 258 #ifdef CONFIG_NET_CLS_ROUTE
 259 extern u32 fib_rules_tclass(struct fib_result *res);
 260 #endif
 261 extern void fib_rules_init(void);
 262 #endif
 263
 264 static inline void fib_combine_itag(u32 *itag, struct fib_result *res)
 265 {
 266 #ifdef CONFIG_NET_CLS_ROUTE
 267 #ifdef CONFIG_IP_MULTIPLE_TABLES
 268         u32 rtag;
 269 #endif
 270         *itag = FIB_RES_NH(*res).nh_tclassid<<16;
 271 #ifdef CONFIG_IP_MULTIPLE_TABLES
 272         rtag = fib_rules_tclass(res);
 273         if (*itag == 0)
 274                 *itag = (rtag<<16);
 275         *itag |= (rtag>>16);
 276 #endif
 277 #endif
 278 }
 279
 280 extern void free_fib_info(struct fib_info *fi);
 281
 282 static inline void fib_info_put(struct fib_info *fi)
 283 {
 284         if (atomic_dec_and_test(&fi->fib_clntref))
 285                 free_fib_info(fi);
 286 }
 287
 288 static inline void fib_res_put(struct fib_result *res)
 289 {
 290         if (res->fi)
 291                 fib_info_put(res->fi);
 292 #ifdef CONFIG_IP_MULTIPLE_TABLES
 293         if (res->r)
 294                 fib_rule_put(res->r);
 295 #endif
 296 }
 297
 298 #endif  /* _NET_FIB_H */