Allows sticky link-local neighbors.

Allows using NEF_STICKY neighbors with link-local addresses. This is
used for static route nexthops, they can be specified like fe80::1%eth0
.

3 files changed, 29 insertions, 7 deletions

diff --git a/nest/iface.c b/nest/iface.c
index bf57a9b1..b8b214e5 100644
--- a/nest/iface.c
+++ b/nest/iface.c
@@ -424,6 +424,24 @@ if_find_by_name(char *name)
   return NULL;
 }
 
+struct iface *
+if_get_by_name(char *name)
+{
+  struct iface *i;
+
+  if (i = if_find_by_name(name))
+    return i;
+
+  /* No active iface, create a dummy */
+  i = mb_allocz(if_pool, sizeof(struct iface));
+  strncpy(i->name, name, sizeof(i->name)-1);
+  i->flags = IF_SHUTDOWN;
+  init_list(&i->addrs);
+  init_list(&i->neighbors);
+  add_tail(&iface_list, &i->n);
+  return i;
+}
+
 struct ifa *kif_choose_primary(struct iface *i);
 
 static int
diff --git a/nest/iface.h b/nest/iface.h
index 7307844e..d6d58ff9 100644
--- a/nest/iface.h
+++ b/nest/iface.h
@@ -97,6 +97,7 @@ void if_flush_ifaces(struct proto *p);
 void if_feed_baby(struct proto *);
 struct iface *if_find_by_index(unsigned);
 struct iface *if_find_by_name(char *);
+struct iface *if_get_by_name(char *);
 void ifa_recalc_all_primary_addresses(void);
 
 /* The Neighbor Cache */
@@ -110,11 +111,13 @@ typedef struct neighbor {
   void *data;				/* Protocol-specific data */
   unsigned aux;				/* Protocol-specific data */
   unsigned flags;
-  unsigned scope;			/* Address scope, SCOPE_HOST when it's our own address */
+  int scope;				/* Address scope, -1 for unreachable sticky neighbors,
+					   SCOPE_HOST when it's our own address */
 } neighbor;
 
 #define NEF_STICKY 1
 #define NEF_ONLINK 2
+#define NEF_BIND 4			/* Used internally for neighbors bound to an iface */
 
 neighbor *neigh_find(struct proto *, ip_addr *, unsigned flags);
 neighbor *neigh_find2(struct proto *p, ip_addr *a, struct iface *ifa, unsigned flags);
diff --git a/nest/neighbor.c b/nest/neighbor.c
index 67bd32b3..506d9bde 100644
--- a/nest/neighbor.c
+++ b/nest/neighbor.c
@@ -133,6 +133,7 @@ neigh_find2(struct proto *p, ip_addr *a, struct iface *ifa, unsigned flags)
   if (ifa)
     {
       scope = if_connected(a, ifa);
+      flags |= NEF_BIND;
 
       if ((scope < 0) && (flags & NEF_ONLINK))
 	scope = class & IADDR_SCOPE_MASK;
@@ -160,10 +161,7 @@ neigh_find2(struct proto *p, ip_addr *a, struct iface *ifa, unsigned flags)
     }
   else
     {
-      /* sticky flag does not work for link-local neighbors;
-	 fortunately, we don't use this combination */
       add_tail(&sticky_neigh_list, &n->n);
-      ifa = NULL;
       scope = -1;
     }
   n->iface = ifa;
@@ -235,7 +233,9 @@ neigh_down(neighbor *n)
 {
   DBG("Flushing neighbor %I on %s\n", n->addr, i->name);
   rem_node(&n->if_n);
-  n->iface = NULL;
+  if (! (n->flags & NEF_BIND))
+    n->iface = NULL;
+  n->scope = -1;
   if (n->proto->neigh_notify && n->proto->core_state != FS_FLUSHING)
     n->proto->neigh_notify(n);
   rem_node(&n->n);
@@ -262,7 +262,8 @@ neigh_if_up(struct iface *i)
   int scope;
 
   WALK_LIST_DELSAFE(n, next, sticky_neigh_list)
-    if ((scope = if_connected(&n->addr, i)) >= 0)
+    if ((!n->iface || n->iface == i) &&
+	((scope = if_connected(&n->addr, i)) >= 0))
       neigh_up(n, i, scope);
 }
 
@@ -339,7 +340,7 @@ neigh_prune_one(neighbor *n)
   if (n->proto->proto_state != PS_DOWN)
     return;
   rem_node(&n->n);
-  if (n->iface)
+  if (n->scope >= 0)
     rem_node(&n->if_n);
   sl_free(neigh_slab, n);
 }