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/*
* BIRD -- Neighbor Cache
*
* (c) 1998--2000 Martin Mares <mj@ucw.cz>
*
* Can be freely distributed and used under the terms of the GNU GPL.
*/
#undef 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 -1;
WALK_LIST(b, i->addrs)
{
if (ipa_equal(*a, b->ip))
return SCOPE_HOST;
if (b->flags & IA_UNNUMBERED)
{
if (ipa_equal(*a, b->opposite))
return b->scope;
}
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 b->scope;
}
}
}
return -1;
}
neighbor *
neigh_find(struct proto *p, ip_addr *a, unsigned flags)
{
neighbor *n;
int class, scope = SCOPE_HOST;
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)
if ((scope = if_connected(a, i)) >= 0)
{
j = i;
break;
}
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;
n->scope = scope;
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 scope %s", n->proto->name, n->data, n->aux, ip_scope_text(n->scope));
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])
neigh_dump(n);
debug("\n");
}
void
neigh_if_up(struct iface *i)
{
neighbor *n, *next;
int scope;
WALK_LIST_DELSAFE(n, next, sticky_neigh_list)
if ((scope = if_connected(&n->addr, i)) >= 0)
{
n->iface = i;
n->scope = scope;
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);
}
}
static inline void
neigh_prune_one(neighbor *n)
{
if (n->proto->core_state != FS_FLUSHING)
return;
rem_node(&n->n);
if (n->iface)
rem_node(&n->if_n);
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])
neigh_prune_one(n);
WALK_LIST_DELSAFE(n, m, sticky_neigh_list)
neigh_prune_one(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]);
}
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