ospf6d: add buffer length check to ifmtu changes

Previous fix was missing the possibility of having to modify the io
buffer size if the kernel reports an new mtu value.  This fix adds
that check.

Signed-off-by: Don Slice <dslice@cumulusnetworks.com>

diff --git a/ospf6d/ospf6_interface.c b/ospf6d/ospf6_interface.c
index 4d07e24b8821dbf4299ecc1ef9a4628c44c1c50f..991eb318d79b1f5434995c86ec2c754c6efff208 100644 (file)
--- a/ospf6d/ospf6_interface.c
+++ b/ospf6d/ospf6_interface.c
@@ -380,6 +380,7 @@ void
 ospf6_interface_state_update (struct interface *ifp)
 {
   struct ospf6_interface *oi;
+  unsigned int iobuflen;
 
   oi = (struct ospf6_interface *) ifp->info;
   if (oi == NULL)
@@ -392,9 +393,19 @@ ospf6_interface_state_update (struct interface *ifp)
   /* Adjust the mtu values if the kernel told us something new */
   if (ifp->mtu6 != oi->ifmtu)
     {
-      /* If nothing configured, just accept it */
+      /* If nothing configured, accept it and check for buffer size */
       if (!oi->c_ifmtu)
-        oi->ifmtu = ifp->mtu6;
+        {
+          oi->ifmtu = ifp->mtu6;
+          iobuflen = ospf6_iobuf_size (ifp->mtu6);
+          if (oi->ifmtu > iobuflen)
+            {
+              if (IS_OSPF6_DEBUG_INTERFACE)
+                zlog_debug ("Interface %s: IfMtu is adjusted to I/O buffer size: %d.",
+                             ifp->name, iobuflen);
+              oi->ifmtu = iobuflen;
+            }
+        }
       else if (oi->c_ifmtu > ifp->mtu6)
         {
           oi->ifmtu = ifp->mtu6;