diff options
Diffstat (limited to 'nest/neighbor.c')
| -rw-r--r-- | nest/neighbor.c | 203 |
1 files changed, 203 insertions, 0 deletions
diff --git a/nest/neighbor.c b/nest/neighbor.c new file mode 100644 index 00000000..e9be8658 --- /dev/null +++ b/nest/neighbor.c @@ -0,0 +1,203 @@ +/* + * BIRD -- Neighbor Cache + * + * (c) 1998--2000 Martin Mares <mj@ucw.cz> + * + * Can be freely distributed and used under the terms of the GNU GPL. + */ + +#define LOCAL_DEBUG + +#include "nest/bird.h" +#include "nest/iface.h" +#include "nest/protocol.h" +#include "lib/resource.h" + +#define NEIGH_HASH_SIZE 256 + +static slab *neigh_slab; +static list sticky_neigh_list, neigh_hash_table[NEIGH_HASH_SIZE]; + +static inline unsigned int +neigh_hash(struct proto *p, ip_addr *a) +{ + return (p->hash_key ^ ipa_hash(*a)) & (NEIGH_HASH_SIZE-1); +} + +static int +if_connected(ip_addr *a, struct iface *i) /* -1=error, 1=match, 0=no match */ +{ + struct ifa *b; + + if (!(i->flags & IF_UP)) + return 0; + WALK_LIST(b, i->addrs) + { + if (ipa_equal(*a, b->ip)) + return -1; + if (b->flags & IA_UNNUMBERED) + { + if (ipa_equal(*a, b->opposite)) + return 1; + } + else + { + if (ipa_in_net(*a, b->prefix, b->pxlen)) + { + if (ipa_equal(*a, b->prefix) || /* Network address */ + ipa_equal(*a, b->brd)) /* Broadcast */ + return -1; + return 1; + } + } + } + return 0; +} + +neighbor * +neigh_find(struct proto *p, ip_addr *a, unsigned flags) +{ + neighbor *n; + int class; + unsigned int h = neigh_hash(p, a); + struct iface *i, *j; + + WALK_LIST(n, neigh_hash_table[h]) /* Search the cache */ + if (n->proto == p && ipa_equal(*a, n->addr)) + return n; + + class = ipa_classify(*a); + if (class < 0) /* Invalid address */ + return NULL; + if ((class & IADDR_SCOPE_MASK) < SCOPE_SITE || + !(class & IADDR_HOST)) + return NULL; /* Bad scope or a somecast */ + + j = NULL; + WALK_LIST(i, iface_list) + switch (if_connected(a, i)) + { + case -1: + return NULL; + case 1: + if (!j) + j = i; + /* Fall-thru */ + } + if (!j && !(flags & NEF_STICKY)) + return NULL; + + n = sl_alloc(neigh_slab); + n->addr = *a; + n->iface = j; + if (j) + { + add_tail(&neigh_hash_table[h], &n->n); + add_tail(&j->neighbors, &n->if_n); + } + else + add_tail(&sticky_neigh_list, &n->n); + n->proto = p; + n->data = NULL; + n->aux = 0; + n->flags = flags; + return n; +} + +void +neigh_dump(neighbor *n) +{ + debug("%p %I ", n, n->addr); + if (n->iface) + debug("%s ", n->iface->name); + else + debug("[] "); + debug("%s %p %08x", n->proto->name, n->data, n->aux); + if (n->flags & NEF_STICKY) + debug(" STICKY"); + debug("\n"); +} + +void +neigh_dump_all(void) +{ + neighbor *n; + int i; + + debug("Known neighbors:\n"); + WALK_LIST(n, sticky_neigh_list) + neigh_dump(n); + for(i=0; i<NEIGH_HASH_SIZE; i++) + WALK_LIST(n, neigh_hash_table[i]); + debug("\n"); +} + +void +neigh_if_up(struct iface *i) +{ + neighbor *n, *next; + + WALK_LIST_DELSAFE(n, next, sticky_neigh_list) + if (!n->iface && + if_connected(&n->addr, i) > 0) + { + n->iface = i; + add_tail(&i->neighbors, &n->if_n); + rem_node(&n->n); + add_tail(&neigh_hash_table[neigh_hash(n->proto, &n->addr)], &n->n); + DBG("Waking up sticky neighbor %I\n", n->addr); + if (n->proto->neigh_notify && n->proto->core_state != FS_FLUSHING) + n->proto->neigh_notify(n); + } +} + +void +neigh_if_down(struct iface *i) +{ + node *x, *y; + + WALK_LIST_DELSAFE(x, y, i->neighbors) + { + neighbor *n = SKIP_BACK(neighbor, if_n, x); + DBG("Flushing neighbor %I on %s\n", n->addr, i->name); + rem_node(&n->if_n); + n->iface = NULL; + if (n->proto->neigh_notify && n->proto->core_state != FS_FLUSHING) + n->proto->neigh_notify(n); + rem_node(&n->n); + if (n->flags & NEF_STICKY) + add_tail(&sticky_neigh_list, &n->n); + else + sl_free(neigh_slab, n); + } +} + +void +neigh_prune(void) +{ + neighbor *n; + node *m; + int i; + + DBG("Pruning neighbors\n"); + for(i=0; i<NEIGH_HASH_SIZE; i++) + WALK_LIST_DELSAFE(n, m, neigh_hash_table[i]) + if (n->proto->core_state == FS_FLUSHING) + { + rem_node(&n->n); + if (n->iface) + rem_node(&n->if_n); + sl_free(neigh_slab, n); + } +} + +void +neigh_init(pool *if_pool) +{ + int i; + + neigh_slab = sl_new(if_pool, sizeof(neighbor)); + init_list(&sticky_neigh_list); + for(i=0; i<NEIGH_HASH_SIZE; i++) + init_list(&neigh_hash_table[i]); +} |