/* * Routing Table * Copyright (C) 1998 Kunihiro Ishiguro * * This file is part of GNU Zebra. * * GNU Zebra is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by the * Free Software Foundation; either version 2, or (at your option) any * later version. * * GNU Zebra is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public License along * with this program; see the file COPYING; if not, write to the Free Software * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ #ifndef _ZEBRA_TABLE_H #define _ZEBRA_TABLE_H #include "memory.h" #include "hash.h" #include "prefix.h" DECLARE_MTYPE(ROUTE_TABLE) DECLARE_MTYPE(ROUTE_NODE) /* * Forward declarations. */ struct route_node; struct route_table; /* * route_table_delegate_t * * Function vector that can be used by a client to customize the * behavior of one or more route tables. */ typedef struct route_table_delegate_t_ route_table_delegate_t; typedef struct route_node *(*route_table_create_node_func_t)( route_table_delegate_t *, struct route_table *); typedef void (*route_table_destroy_node_func_t)(route_table_delegate_t *, struct route_table *, struct route_node *); struct route_table_delegate_t_ { route_table_create_node_func_t create_node; route_table_destroy_node_func_t destroy_node; }; /* Routing table top structure. */ struct route_table { struct route_node *top; struct hash *hash; /* * Delegate that performs certain functions for this table. */ route_table_delegate_t *delegate; void (*cleanup)(struct route_table *, struct route_node *); unsigned long count; /* * User data. */ void *info; }; /* * node->link is really internal to the table code and should not be * accessed by outside code. We don't have any writers (yay), though some * readers are left to be fixed. * * rationale: we need to add a hash table in parallel, to speed up * exact-match lookups. * * same really applies for node->parent, though that's less of an issue. * table->link should be - and is - NEVER written by outside code */ #ifdef FRR_COMPILING_TABLE_C #define table_rdonly(x) x #define table_internal(x) x #else #define table_rdonly(x) const x #define table_internal(x) \ const x __attribute__( \ (deprecated("this should only be accessed by lib/table.c"))) /* table_internal is for node->link and node->lock, once we have done * something about remaining accesses */ #endif /* so... the problem with this is that "const" doesn't mean "readonly". * It in fact may allow the compiler to optimize based on the assumption * that the value doesn't change. Hence, since the only purpose of this * is to aid in development, don't put the "const" in release builds. * * (I haven't seen this actually break, but GCC and LLVM are getting ever * more aggressive in optimizing...) */ #ifndef DEV_BUILD #undef table_rdonly #define table_rdonly(x) x #endif /* * Macro that defines all fields in a route node. */ #define ROUTE_NODE_FIELDS \ /* Actual prefix of this radix. */ \ struct prefix p; \ \ /* Tree link. */ \ struct route_table *table_rdonly(table); \ struct route_node *table_rdonly(parent); \ struct route_node *table_rdonly(link[2]); \ \ /* Lock of this radix */ \ unsigned int table_rdonly(lock); \ \ /* Each node of route. */ \ void *info; \ /* Each routing entry. */ struct route_node { ROUTE_NODE_FIELDS #define l_left link[0] #define l_right link[1] }; typedef struct route_table_iter_t_ route_table_iter_t; typedef enum { RT_ITER_STATE_INIT, RT_ITER_STATE_ITERATING, RT_ITER_STATE_PAUSED, RT_ITER_STATE_DONE } route_table_iter_state_t; /* * route_table_iter_t * * Structure that holds state for iterating over a route table. */ struct route_table_iter_t_ { route_table_iter_state_t state; /* * Routing table that we are iterating over. The caller must ensure * that that table outlives the iterator. */ struct route_table *table; /* * The node that the iterator is currently on. */ struct route_node *current; /* * The last prefix that the iterator processed before it was paused. */ struct prefix pause_prefix; }; /* Prototypes. */ extern struct route_table *route_table_init(void); extern struct route_table * route_table_init_with_delegate(route_table_delegate_t *delegate); extern route_table_delegate_t *route_table_get_default_delegate(void); extern void route_table_finish(struct route_table *table); extern struct route_node *route_top(struct route_table *table); extern struct route_node *route_next(struct route_node *node); extern struct route_node *route_next_until(struct route_node *node, const struct route_node *limit); extern struct route_node *route_node_get(struct route_table *const table, union prefixconstptr pu); extern struct route_node *route_node_lookup(const struct route_table *table, union prefixconstptr pu); extern struct route_node * route_node_lookup_maynull(const struct route_table *table, union prefixconstptr pu); extern struct route_node *route_node_match(const struct route_table *table, union prefixconstptr pu); extern struct route_node *route_node_match_ipv4(const struct route_table *table, const struct in_addr *addr); extern struct route_node *route_node_match_ipv6(const struct route_table *table, const struct in6_addr *addr); extern unsigned long route_table_count(const struct route_table *table); extern struct route_node *route_node_create(route_table_delegate_t *delegate, struct route_table *table); extern void route_node_delete(struct route_node *node); extern void route_node_destroy(route_table_delegate_t *delegate, struct route_table *table, struct route_node *node); extern struct route_node *route_table_get_next(const struct route_table *table, union prefixconstptr pu); extern int route_table_prefix_iter_cmp(const struct prefix *p1, const struct prefix *p2); /* * Iterator functions. */ extern void route_table_iter_init(route_table_iter_t *iter, struct route_table *table); extern void route_table_iter_pause(route_table_iter_t *iter); extern void route_table_iter_cleanup(route_table_iter_t *iter); /* * Inline functions. */ /* Lock node. */ static inline struct route_node *route_lock_node(struct route_node *node) { (*(unsigned *)&node->lock)++; return node; } /* Unlock node. */ static inline void route_unlock_node(struct route_node *node) { assert(node->lock > 0); (*(unsigned *)&node->lock)--; if (node->lock == 0) route_node_delete(node); } /* * route_table_iter_next * * Get the next node in the tree. */ static inline struct route_node *route_table_iter_next(route_table_iter_t *iter) { struct route_node *node; switch (iter->state) { case RT_ITER_STATE_INIT: /* * We're just starting the iteration. */ node = route_top(iter->table); break; case RT_ITER_STATE_ITERATING: node = route_next(iter->current); break; case RT_ITER_STATE_PAUSED: /* * Start with the node following pause_prefix. */ node = route_table_get_next(iter->table, &iter->pause_prefix); break; case RT_ITER_STATE_DONE: return NULL; default: assert(0); } iter->current = node; if (node) iter->state = RT_ITER_STATE_ITERATING; else iter->state = RT_ITER_STATE_DONE; return node; } /* * route_table_iter_is_done * * Returns TRUE if the iteration is complete. */ static inline int route_table_iter_is_done(route_table_iter_t *iter) { return iter->state == RT_ITER_STATE_DONE; } /* * route_table_iter_started * * Returns TRUE if this iterator has started iterating over the tree. */ static inline int route_table_iter_started(route_table_iter_t *iter) { return iter->state != RT_ITER_STATE_INIT; } #endif /* _ZEBRA_TABLE_H */