From a97122a3caff40bf35e6019a9b60d5e5ef35a84f Mon Sep 17 00:00:00 2001
From: Ondrej Zajicek <santiago@crfreenet.org>
Date: Sun, 26 Oct 2008 23:43:13 +0100
Subject: [PATCH] Bugfix in LSA origination for PTP OSPF links.

The code generating LSAs for PTP OSPF links is buggy. The old behavior
is that it generates PTP link if there is a full/ptp neighbor and stub
link if there isn't. According to RFC 2328, the correct behavior is to
generate stub link in both cases (in the first case together with PTP
link).

And because of buggy detection of unnumbered networks, for numbered
networks the code creates stub links with 0.0.0.0/32.
---
 proto/ospf/topology.c | 42 +++++++++++++++++++++++++++++++-----------
 1 file changed, 31 insertions(+), 11 deletions(-)

diff --git a/proto/ospf/topology.c b/proto/ospf/topology.c
index 419a3951..1d6b06ef 100644
--- a/proto/ospf/topology.c
+++ b/proto/ospf/topology.c
@@ -20,6 +20,8 @@
 #define HASH_LO_STEP 2
 #define HASH_LO_MIN 8
 
+int ptp_unnumbered_stub_lsa = 0;
+
 static void *
 originate_rt_lsa_body(struct ospf_area *oa, u16 * length)
 {
@@ -28,7 +30,7 @@ originate_rt_lsa_body(struct ospf_area *oa, u16 * length)
   int j = 0, k = 0;
   u16 i = 0;
   struct ospf_lsa_rt *rt;
-  struct ospf_lsa_rt_link *ln;
+  struct ospf_lsa_rt_link *ln, *ln_after;
   struct ospf_neighbor *neigh;
 
   DBG("%s: Originating RT_lsa body for area \"%I\".\n", po->proto.name,
@@ -39,6 +41,9 @@ originate_rt_lsa_body(struct ospf_area *oa, u16 * length)
     if ((ifa->oa == oa) && (ifa->state != OSPF_IS_DOWN))
     {
       i++;
+      if ((ifa->type == OSPF_IT_PTP) && (ifa->state == OSPF_IS_PTP) &&
+      	  (ptp_unnumbered_stub_lsa || !(ifa->iface->addr->flags & IA_UNNUMBERED)))
+        i++;
     }
   }
   rt = mb_allocz(po->proto.pool, sizeof(struct ospf_lsa_rt) +
@@ -48,6 +53,7 @@ originate_rt_lsa_body(struct ospf_area *oa, u16 * length)
   if ((po->ebit) && (!oa->stub))
     rt->veb.bit.e = 1;
   ln = (struct ospf_lsa_rt_link *) (rt + 1);
+  ln_after = ln + i;
 
   WALK_LIST(ifa, po->iface_list)
   {
@@ -61,6 +67,9 @@ originate_rt_lsa_body(struct ospf_area *oa, u16 * length)
     if ((ifa->oa != oa) || (ifa->state == OSPF_IS_DOWN))
       continue;
 
+    if (ln == ln_after)
+      die("LSA space overflow");
+
     if (ifa->state == OSPF_IS_LOOP)
     {
       ln->type = 3;
@@ -81,7 +90,7 @@ originate_rt_lsa_body(struct ospf_area *oa, u16 * length)
 	  ln->id = neigh->rid;
 	  ln->metric = ifa->cost;
 	  ln->notos = 0;
-	  if (ifa->iface->flags && IA_UNNUMBERED)
+	  if (ifa->iface->addr->flags & IA_UNNUMBERED)
 	  {
 	    ln->data = ifa->iface->index;
 	  }
@@ -92,19 +101,30 @@ originate_rt_lsa_body(struct ospf_area *oa, u16 * length)
 	}
 	else
 	{
-	  if (ifa->state == OSPF_IS_PTP)
+          ln--;
+	  i--;		/* No link added */
+        }
+
+	if ((ifa->state == OSPF_IS_PTP) && 
+	    (ptp_unnumbered_stub_lsa || !(ifa->iface->addr->flags & IA_UNNUMBERED)))
+	{
+	  ln++;
+	  if (ln == ln_after)
+            die("LSA space overflow");
+
+	  ln->type = LSART_STUB;
+	  ln->metric = ifa->cost;
+	  ln->notos = 0;
+	  if (ifa->iface->addr->flags & IA_UNNUMBERED)
 	  {
-	    ln->type = LSART_STUB;
-	    ln->id = ln->id = ipa_to_u32(ifa->iface->addr->opposite);
-	    ln->metric = ifa->cost;
-	    ln->notos = 0;
+	    ln->id = ipa_to_u32(ifa->iface->addr->opposite);
 	    ln->data = 0xffffffff;
 	  }
 	  else
-          {
-            ln--;
-	    i--;		/* No link added */
-          }
+	  {
+	    ln->data = ipa_to_u32(ipa_mkmask(ifa->iface->addr->pxlen));
+	    ln->id = ipa_to_u32(ifa->iface->addr->prefix) & ln->data;
+	  }
 	}
 	break;
       case OSPF_IT_BCAST: