From 727d104b15d6293d7223e7830f2e37ae98022cac Mon Sep 17 00:00:00 2001
From: paul <paul>
Date: Fri, 13 Dec 2002 20:50:29 +0000
Subject: Added RIPv1 patch - bug fixes and improved/more interoperable
 classful subnet handling

---
 lib/if.c | 59 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 lib/if.h |  1 +
 2 files changed, 60 insertions(+)

(limited to 'lib')

diff --git a/lib/if.c b/lib/if.c
index bbf22ab1..0934e40d 100644
--- a/lib/if.c
+++ b/lib/if.c
@@ -553,6 +553,65 @@ connected_delete_by_prefix (struct interface *ifp, struct prefix *p)
   return NULL;
 }
 
+/* Find the IPv4 address on our side that will be used when packets
+   are sent to dst. */
+struct connected *
+connected_lookup_address (struct interface *ifp, struct in_addr dst)
+{
+  struct prefix addr;
+  struct prefix best;
+  listnode cnode;
+  struct prefix *p;
+  struct connected *c;
+  struct connected *match;
+
+  /* Zero structures - get rid of rubbish from stack */
+  memset(&addr, 0, sizeof(addr));
+  memset(&best, 0, sizeof(best));
+
+  addr.family = AF_INET;
+  addr.u.prefix4 = dst;
+  addr.prefixlen = IPV4_MAX_BITLEN;
+
+  match = NULL;
+
+  for (cnode = listhead (ifp->connected); cnode; nextnode (cnode))
+    {
+      c = getdata (cnode);
+
+      if (if_is_pointopoint (ifp))
+	{
+	  p = c->address;
+
+	  if (p && p->family == AF_INET)
+	    {
+#ifdef OLD_RIB	 /* PTP  links are conventionally identified 
+		    by the address of the far end - MAG */
+	      if (IPV4_ADDR_SAME (&p->u.prefix4, &dst))
+		return c;
+#endif
+	      p = c->destination;
+	      if (p && IPV4_ADDR_SAME (&p->u.prefix4, &dst))
+		return c;
+	    }
+	}
+      else
+	{
+	  p = c->address;
+
+	  if (p->family == AF_INET)
+	    {
+	      if (prefix_match (p, &addr) && p->prefixlen > best.prefixlen)
+		{
+		  best = *p;
+		  match = c;
+		}
+	    }
+	}
+    }
+  return match;
+}
+
 /* Check the connected information is PtP style or not.  */
 int
 ifc_pointopoint (struct connected *ifc)
diff --git a/lib/if.h b/lib/if.h
index 3896d187..55337fc4 100644
--- a/lib/if.h
+++ b/lib/if.h
@@ -202,6 +202,7 @@ struct connected *connected_new ();
 void connected_free (struct connected *);
 void connected_add (struct interface *, struct connected *);
 struct connected  *connected_delete_by_prefix (struct interface *, struct prefix *);
+struct connected  *connected_lookup_address (struct interface *, struct in_addr);
 int ifc_pointopoint (struct connected *);
 
 #ifndef HAVE_IF_NAMETOINDEX
-- 
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