zebra/rib.h

   1 /*
   2  * Routing Information Base header
   3  * Copyright (C) 1997 Kunihiro Ishiguro
   4  *
   5  * This file is part of GNU Zebra.
   6  *
   7  * GNU Zebra is free software; you can redistribute it and/or modify it
   8  * under the terms of the GNU General Public License as published by the
   9  * Free Software Foundation; either version 2, or (at your option) any
  10  * later version.
  11  *
  12  * GNU Zebra is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with GNU Zebra; see the file COPYING.  If not, write to the Free
  19  * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  20  * 02111-1307, USA.
  21  */
  22
  23 #ifndef _ZEBRA_RIB_H
  24 #define _ZEBRA_RIB_H
  25
  26 #include "zebra.h"
  27 #include "hook.h"
  28 #include "linklist.h"
  29 #include "prefix.h"
  30 #include "table.h"
  31 #include "queue.h"
  32 #include "nexthop.h"
  33 #include "vrf.h"
  34 #include "if.h"
  35 #include "mpls.h"
  36 #include "srcdest_table.h"
  37
  38 #define DISTANCE_INFINITY  255
  39 #define ZEBRA_KERNEL_TABLE_MAX 252 /* support for no more than this rt tables */
  40
  41 struct rib {
  42         /* Link list. */
  43         struct rib *next;
  44         struct rib *prev;
  45
  46         /* Nexthop structure */
  47         struct nexthop *nexthop;
  48
  49         /* Refrence count. */
  50         unsigned long refcnt;
  51
  52         /* Tag */
  53         route_tag_t tag;
  54
  55         /* Uptime. */
  56         time_t uptime;
  57
  58         /* Type fo this route. */
  59         int type;
  60
  61         /* Source protocol instance */
  62         u_short instance;
  63
  64         /* VRF identifier. */
  65         vrf_id_t vrf_id;
  66
  67         /* Which routing table */
  68         uint32_t table;
  69
  70         /* Metric */
  71         u_int32_t metric;
  72
  73         /* MTU */
  74         u_int32_t mtu;
  75         u_int32_t nexthop_mtu;
  76
  77         /* Distance. */
  78         u_char distance;
  79
  80         /* Flags of this route.
  81          * This flag's definition is in lib/zebra.h ZEBRA_FLAG_* and is exposed
  82          * to clients via Zserv
  83          */
  84         u_int32_t flags;
  85
  86         /* RIB internal status */
  87         u_char status;
  88 #define RIB_ENTRY_REMOVED          0x1
  89 /* to simplify NHT logic when NHs change, instead of doing a NH by NH cmp */
  90 #define RIB_ENTRY_NEXTHOPS_CHANGED 0x2
  91 #define RIB_ENTRY_CHANGED          0x4
  92 #define RIB_ENTRY_SELECTED_FIB     0x8
  93 #define RIB_ENTRY_LABELS_CHANGED   0x10
  94
  95         /* Nexthop information. */
  96         u_char nexthop_num;
  97         u_char nexthop_active_num;
  98 };
  99
 100 /* meta-queue structure:
 101  * sub-queue 0: connected, kernel
 102  * sub-queue 1: static
 103  * sub-queue 2: RIP, RIPng, OSPF, OSPF6, IS-IS
 104  * sub-queue 3: iBGP, eBGP
 105  * sub-queue 4: any other origin (if any)
 106  */
 107 #define MQ_SIZE 5
 108 struct meta_queue {
 109         struct list *subq[MQ_SIZE];
 110         u_int32_t size; /* sum of lengths of all subqueues */
 111 };
 112
 113 /*
 114  * Structure that represents a single destination (prefix).
 115  */
 116 typedef struct rib_dest_t_ {
 117
 118         /*
 119          * Back pointer to the route node for this destination. This helps
 120          * us get to the prefix that this structure is for.
 121          */
 122         struct route_node *rnode;
 123
 124         /*
 125          * Doubly-linked list of routes for this prefix.
 126          */
 127         struct rib *routes;
 128
 129         /*
 130          * Flags, see below.
 131          */
 132         u_int32_t flags;
 133
 134         /*
 135          * Linkage to put dest on the FPM processing queue.
 136          */
 137         TAILQ_ENTRY(rib_dest_t_) fpm_q_entries;
 138
 139 } rib_dest_t;
 140
 141 #define RIB_ROUTE_QUEUED(x)     (1 << (x))
 142
 143 /*
 144  * The maximum qindex that can be used.
 145  */
 146 #define ZEBRA_MAX_QINDEX        (MQ_SIZE - 1)
 147
 148 /*
 149  * This flag indicates that a given prefix has been 'advertised' to
 150  * the FPM to be installed in the forwarding plane.
 151  */
 152 #define RIB_DEST_SENT_TO_FPM   (1 << (ZEBRA_MAX_QINDEX + 1))
 153
 154 /*
 155  * This flag is set when we need to send an update to the FPM about a
 156  * dest.
 157  */
 158 #define RIB_DEST_UPDATE_FPM    (1 << (ZEBRA_MAX_QINDEX + 2))
 159
 160 /*
 161  * Macro to iterate over each route for a destination (prefix).
 162  */
 163 #define RIB_DEST_FOREACH_ROUTE(dest, rib)                                      \
 164         for ((rib) = (dest) ? (dest)->routes : NULL; (rib); (rib) = (rib)->next)
 165
 166 /*
 167  * Same as above, but allows the current node to be unlinked.
 168  */
 169 #define RIB_DEST_FOREACH_ROUTE_SAFE(dest, rib, next)                           \
 170         for ((rib) = (dest) ? (dest)->routes : NULL;                           \
 171              (rib) && ((next) = (rib)->next, 1); (rib) = (next))
 172
 173 #define RNODE_FOREACH_RIB(rn, rib)                                             \
 174         RIB_DEST_FOREACH_ROUTE(rib_dest_from_rnode(rn), rib)
 175
 176 #define RNODE_FOREACH_RIB_SAFE(rn, rib, next)                                  \
 177         RIB_DEST_FOREACH_ROUTE_SAFE(rib_dest_from_rnode(rn), rib, next)
 178
 179 /* The following for loop allows to iterate over the nexthop
 180  * structure of routes.
 181  *
 182  * We have to maintain quite a bit of state:
 183  *
 184  * nexthop:   The pointer to the current nexthop, either in the
 185  *            top-level chain or in the resolved chain of ni.
 186  * tnexthop:  The pointer to the current nexthop in the top-level
 187  *            nexthop chain.
 188  * recursing: Information if nh currently is in the top-level chain
 189  *            (0) or in a resolved chain (1).
 190  *
 191  * Initialization: Set `nexthop' and `tnexthop' to the head of the
 192  * top-level chain. As nexthop is in the top level chain, set recursing
 193  * to 0.
 194  *
 195  * Iteration check: Check that the `nexthop' pointer is not NULL.
 196  *
 197  * Iteration step: This is the tricky part. Check if `nexthop' has
 198  * NEXTHOP_FLAG_RECURSIVE set. If yes, this implies that `nexthop' is in
 199  * the top level chain and has at least one nexthop attached to
 200  * `nexthop->resolved'. As we want to descend into `nexthop->resolved',
 201  * set `recursing' to 1 and set `nexthop' to `nexthop->resolved'.
 202  * `tnexthop' is left alone in that case so we can remember which nexthop
 203  * in the top level chain we are currently handling.
 204  *
 205  * If NEXTHOP_FLAG_RECURSIVE is not set, `nexthop' will progress in its
 206  * current chain. If we are recursing, `nexthop' will be set to
 207  * `nexthop->next' and `tnexthop' will be left alone. If we are not
 208  * recursing, both `tnexthop' and `nexthop' will be set to `nexthop->next'
 209  * as we are progressing in the top level chain.
 210  *   If we encounter `nexthop->next == NULL', we will clear the `recursing'
 211  * flag as we arived either at the end of the resolved chain or at the end
 212  * of the top level chain. In both cases, we set `tnexthop' and `nexthop'
 213  * to `tnexthop->next', progressing to the next position in the top-level
 214  * chain and possibly to its end marked by NULL.
 215  */
 216 #define ALL_NEXTHOPS_RO(head, nexthop, tnexthop, recursing)                    \
 217         (tnexthop) = (nexthop) = (head), (recursing) = 0;                      \
 218         (nexthop);                                                             \
 219         (nexthop) =                                                            \
 220                 CHECK_FLAG((nexthop)->flags, NEXTHOP_FLAG_RECURSIVE)           \
 221                         ? (((recursing) = 1), (nexthop)->resolved)             \
 222                         : ((nexthop)->next                                     \
 223                                    ? ((recursing) ? (nexthop)->next            \
 224                                                   : ((tnexthop) =              \
 225                                                              (nexthop)->next)) \
 226                                    : (((recursing) = 0),                       \
 227                                       ((tnexthop) = (tnexthop)->next)))
 228
 229 #if defined(HAVE_RTADV)
 230 /* Structure which hold status of router advertisement. */
 231 struct rtadv {
 232         int sock;
 233
 234         int adv_if_count;
 235         int adv_msec_if_count;
 236
 237         struct thread *ra_read;
 238         struct thread *ra_timer;
 239 };
 240 #endif /* HAVE_RTADV */
 241
 242 /*
 243  * rib_table_info_t
 244  *
 245  * Structure that is hung off of a route_table that holds information about
 246  * the table.
 247  */
 248 typedef struct rib_table_info_t_ {
 249
 250         /*
 251          * Back pointer to zebra_vrf.
 252          */
 253         struct zebra_vrf *zvrf;
 254         afi_t afi;
 255         safi_t safi;
 256
 257 } rib_table_info_t;
 258
 259 typedef enum {
 260         RIB_TABLES_ITER_S_INIT,
 261         RIB_TABLES_ITER_S_ITERATING,
 262         RIB_TABLES_ITER_S_DONE
 263 } rib_tables_iter_state_t;
 264
 265 /*
 266  * Structure that holds state for iterating over all tables in the
 267  * Routing Information Base.
 268  */
 269 typedef struct rib_tables_iter_t_ {
 270         vrf_id_t vrf_id;
 271         int afi_safi_ix;
 272
 273         rib_tables_iter_state_t state;
 274 } rib_tables_iter_t;
 275
 276 /* Events/reasons triggering a RIB update. */
 277 typedef enum {
 278         RIB_UPDATE_IF_CHANGE,
 279         RIB_UPDATE_RMAP_CHANGE,
 280         RIB_UPDATE_OTHER
 281 } rib_update_event_t;
 282
 283 extern struct nexthop *rib_nexthop_ifindex_add(struct rib *, ifindex_t);
 284 extern struct nexthop *rib_nexthop_blackhole_add(struct rib *);
 285 extern struct nexthop *rib_nexthop_ipv4_add(struct rib *, struct in_addr *,
 286                                             struct in_addr *);
 287 extern struct nexthop *rib_nexthop_ipv4_ifindex_add(struct rib *,
 288                                                     struct in_addr *,
 289                                                     struct in_addr *,
 290                                                     ifindex_t);
 291 extern void rib_nexthop_add(struct rib *rib, struct nexthop *nexthop);
 292 extern void rib_copy_nexthops(struct rib *rib, struct nexthop *nh);
 293
 294 /* RPF lookup behaviour */
 295 enum multicast_mode {
 296         MCAST_NO_CONFIG = 0,  /* MIX_MRIB_FIRST, but no show in config write */
 297         MCAST_MRIB_ONLY,      /* MRIB only */
 298         MCAST_URIB_ONLY,      /* URIB only */
 299         MCAST_MIX_MRIB_FIRST, /* MRIB, if nothing at all then URIB */
 300         MCAST_MIX_DISTANCE,   /* MRIB & URIB, lower distance wins */
 301         MCAST_MIX_PFXLEN,     /* MRIB & URIB, longer prefix wins */
 302                               /* on equal value, MRIB wins for last 2 */
 303 };
 304
 305 extern void multicast_mode_ipv4_set(enum multicast_mode mode);
 306 extern enum multicast_mode multicast_mode_ipv4_get(void);
 307
 308 extern int nexthop_has_fib_child(struct nexthop *);
 309 extern void rib_lookup_and_dump(struct prefix_ipv4 *, vrf_id_t);
 310 extern void rib_lookup_and_pushup(struct prefix_ipv4 *, vrf_id_t);
 311 #define rib_dump(prefix, src, rib) _rib_dump(__func__, prefix, src, rib)
 312 extern void _rib_dump(const char *, union prefixconstptr, union prefixconstptr,
 313                       const struct rib *);
 314 extern int rib_lookup_ipv4_route(struct prefix_ipv4 *, union sockunion *,
 315                                  vrf_id_t);
 316 #define ZEBRA_RIB_LOOKUP_ERROR -1
 317 #define ZEBRA_RIB_FOUND_EXACT 0
 318 #define ZEBRA_RIB_FOUND_NOGATE 1
 319 #define ZEBRA_RIB_FOUND_CONNECTED 2
 320 #define ZEBRA_RIB_NOTFOUND 3
 321
 322 extern void rib_nexthop_delete(struct rib *rib, struct nexthop *nexthop);
 323 extern struct nexthop *rib_nexthop_ipv6_add(struct rib *, struct in6_addr *);
 324 extern struct nexthop *rib_nexthop_ipv6_ifindex_add(struct rib *rib,
 325                                                     struct in6_addr *ipv6,
 326                                                     ifindex_t ifindex);
 327
 328 extern int is_zebra_valid_kernel_table(u_int32_t table_id);
 329 extern int is_zebra_main_routing_table(u_int32_t table_id);
 330 extern int zebra_check_addr(struct prefix *p);
 331
 332 extern void rib_addnode(struct route_node *rn, struct rib *rib, int process);
 333 extern void rib_delnode(struct route_node *rn, struct rib *rib);
 334 extern int rib_install_kernel(struct route_node *rn, struct rib *rib,
 335                               struct rib *old);
 336 extern int rib_uninstall_kernel(struct route_node *rn, struct rib *rib);
 337
 338 /* NOTE:
 339  * All rib_add function will not just add prefix into RIB, but
 340  * also implicitly withdraw equal prefix of same type. */
 341 extern int rib_add(afi_t afi, safi_t safi, vrf_id_t vrf_id, int type,
 342                    u_short instance, int flags, struct prefix *p,
 343                    struct prefix_ipv6 *src_p, union g_addr *gate,
 344                    union g_addr *src, ifindex_t ifindex, u_int32_t table_id,
 345                    u_int32_t, u_int32_t, u_char);
 346
 347 extern int rib_add_multipath(afi_t afi, safi_t safi, struct prefix *,
 348                              struct prefix_ipv6 *src_p, struct rib *);
 349
 350 extern void rib_delete(afi_t afi, safi_t safi, vrf_id_t vrf_id, int type,
 351                        u_short instance, int flags, struct prefix *p,
 352                        struct prefix_ipv6 *src_p, union g_addr *gate,
 353                        ifindex_t ifindex, u_int32_t table_id);
 354
 355 extern struct rib *rib_match(afi_t afi, safi_t safi, vrf_id_t, union g_addr *,
 356                              struct route_node **rn_out);
 357 extern struct rib *rib_match_ipv4_multicast(vrf_id_t vrf_id,
 358                                             struct in_addr addr,
 359                                             struct route_node **rn_out);
 360
 361 extern struct rib *rib_lookup_ipv4(struct prefix_ipv4 *, vrf_id_t);
 362
 363 extern void rib_update(vrf_id_t, rib_update_event_t);
 364 extern void rib_weed_tables(void);
 365 extern void rib_sweep_route(void);
 366 extern void rib_close_table(struct route_table *);
 367 extern void rib_init(void);
 368 extern unsigned long rib_score_proto(u_char proto, u_short instance);
 369 extern void rib_queue_add(struct route_node *rn);
 370 extern void meta_queue_free(struct meta_queue *mq);
 371
 372 extern struct route_table *rib_table_ipv6;
 373
 374 extern void rib_unlink(struct route_node *, struct rib *);
 375 extern int rib_gc_dest(struct route_node *rn);
 376 extern struct route_table *rib_tables_iter_next(rib_tables_iter_t *iter);
 377
 378 extern u_char route_distance(int type);
 379
 380 /*
 381  * Inline functions.
 382  */
 383
 384 /*
 385  * rib_table_info
 386  */
 387 static inline rib_table_info_t *rib_table_info(struct route_table *table)
 388 {
 389         return (rib_table_info_t *)table->info;
 390 }
 391
 392 /*
 393  * rib_dest_from_rnode
 394  */
 395 static inline rib_dest_t *rib_dest_from_rnode(struct route_node *rn)
 396 {
 397         return (rib_dest_t *)rn->info;
 398 }
 399
 400 /*
 401  * rnode_to_ribs
 402  *
 403  * Returns a pointer to the list of routes corresponding to the given
 404  * route_node.
 405  */
 406 static inline struct rib *rnode_to_ribs(struct route_node *rn)
 407 {
 408         rib_dest_t *dest;
 409
 410         dest = rib_dest_from_rnode(rn);
 411         if (!dest)
 412                 return NULL;
 413
 414         return dest->routes;
 415 }
 416
 417 /*
 418  * rib_dest_prefix
 419  */
 420 static inline struct prefix *rib_dest_prefix(rib_dest_t *dest)
 421 {
 422         return &dest->rnode->p;
 423 }
 424
 425 /*
 426  * rib_dest_af
 427  *
 428  * Returns the address family that the destination is for.
 429  */
 430 static inline u_char rib_dest_af(rib_dest_t *dest)
 431 {
 432         return dest->rnode->p.family;
 433 }
 434
 435 /*
 436  * rib_dest_table
 437  */
 438 static inline struct route_table *rib_dest_table(rib_dest_t *dest)
 439 {
 440         return srcdest_rnode_table(dest->rnode);
 441 }
 442
 443 /*
 444  * rib_dest_vrf
 445  */
 446 static inline struct zebra_vrf *rib_dest_vrf(rib_dest_t *dest)
 447 {
 448         return rib_table_info(rib_dest_table(dest))->zvrf;
 449 }
 450
 451 /*
 452  * rib_tables_iter_init
 453  */
 454 static inline void rib_tables_iter_init(rib_tables_iter_t *iter)
 455
 456 {
 457         memset(iter, 0, sizeof(*iter));
 458         iter->state = RIB_TABLES_ITER_S_INIT;
 459 }
 460
 461 /*
 462  * rib_tables_iter_started
 463  *
 464  * Returns TRUE if this iterator has started iterating over the set of
 465  * tables.
 466  */
 467 static inline int rib_tables_iter_started(rib_tables_iter_t *iter)
 468 {
 469         return iter->state != RIB_TABLES_ITER_S_INIT;
 470 }
 471
 472 /*
 473  * rib_tables_iter_cleanup
 474  */
 475 static inline void rib_tables_iter_cleanup(rib_tables_iter_t *iter)
 476 {
 477         iter->state = RIB_TABLES_ITER_S_DONE;
 478 }
 479
 480 DECLARE_HOOK(rib_update, (struct route_node * rn, const char *reason),
 481              (rn, reason))
 482
 483 #endif /*_ZEBRA_RIB_H */