Reimplemented neighbor cache. Now uses real hashing.

1 files changed, 203 insertions, 0 deletions

diff --git a/nest/neighbor.c b/nest/neighbor.c
new file mode 100644
index 0000000..e9be865
--- /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]);
+}