2005-04-02 Andrew J. Schorr <ajschorr@alumni.princeton.edu>

	Fix problems when netlink interfaces are renamed (same ifindex used
	for a new interface).  Start cleaning up some problems with the way
	interface names are handled.
	* interface.c: (if_new_intern_ifindex) Remove obsolete function.
	  (if_delete_update) After distributing the interface deletion message,
	  set ifp->ifindex to IFINDEX_INTERNAL.
	  (if_dump_vty) Detect pseudo interface by checking if ifp->ifindex is
	  IFINDEX_INTERNAL.
	  (zebra_interface) Check return code from interface_cmd.func.
	  Do not set internal ifindex values to if_new_intern_ifindex(),
	  since we now use IFINDEX_INTERNAL for all pseudo interfaces.
	* kernel_socket.c: (ifm_read) Fix code and comments to reflect that
	  all internal interfaces now have ifp->ifindex set to IFINDEX_INTERNAL.
        * rt_netlink.c: (set_ifindex) New function used to update ifp->ifindex.
	  Detects interface rename events by checking if that ifindex is already
	  being used.  If it is, delete the old interface before assigning
	  the ifindex to the new interface.
	  (netlink_interface, netlink_link_change) Call set_ifindex to update
	  the ifindex.
	* if.h: Remove define for IFINDEX_INTERNBASE and add define
	  IFINDEX_INTERNAL 0, since all internal (i.e. non-kernel) pseudo-
	  interfaces should have ifindex set to 0.
	  (if_new) Remove function.
	  (if_delete_retain) New function to delete an interface without
	  removing from iflist and freeing the structure.
	  (ifname2ifindex) New function.
	* if.c: (if_new) Remove function (absorb into if_create).
	  (if_create) Replace function if_new with call to calloc.
	  Set ifp->ifindex to IFINDEX_INTERNAL.  Fix off-by-one error
	  in assert to check length of interface name.  Add error message
	  if interface with this name already exists.
	  (if_delete_retain) New function to delete an interface without
	  removing from iflist and freeing the structure.
	  (if_delete) Implement with help of if_delete_retain.
	  (ifindex2ifname) Reimplement using if_lookup_by_index.
	  (ifname2ifindex) New function to complement ifindex2ifname.
	  (interface) The interface command should check the name length
	  and fail with a warning message if it is too long.
	  (no_interface) Fix spelling in warning message.
	  (if_nametoindex) Reimplement using if_lookup_by_name.
	  (if_indextoname, ifaddr_ipv4_lookup) Reimplement using
	  if_lookup_by_index.
	* bgp_zebra.c: (bgp_interface_delete) After deleting, set ifp->ifindex
	  to IFINDEX_INTERNAL.
	* isis_zebra.c: (isis_zebra_if_del) Call if_delete_retain instead
	  of if_delete, since it is generally not safe to remove interface
	  structures.  After deleting, set ifp->ifindex to IFINDEX_INTERNAL.
	  (zebra_interface_if_lookup) Tighten up code.
	* ospf6_zebra.c: (ospf6_zebra_if_del) Previously, this whole function
	  was commented out.  But this is not safe: we should at least update
	  the ifindex when the interface is deleted.  So the new version
	  updates the interface status and sets ifp->ifindex to
	  IFINDEX_INTERNAL.
	  (ospf6_zebra_route_update) Use if_indextoname properly.
	* ospf_vty.c: (show_ip_ospf_interface_sub) Show ifindex and interface
	  flags to help with debugging.
	* ospf_zebra.c: (ospf_interface_delete) After deleting, set ifp->ifindex
	  to IFINDEX_INTERNAL.
	  (zebra_interface_if_lookup) Make function static.  Tighten up code.
	* rip_interface.c: (rip_interface_delete) After deleting, set
	  ifp->ifindex to IFINDEX_INTERNAL.
	* ripng_interface.c: (ripng_interface_delete) After deleting, set
	  ifp->ifindex to IFINDEX_INTERNAL.

2 files changed, 15 insertions, 10 deletions

diff --git a/isisd/ChangeLog b/isisd/ChangeLog
index d7fadd0c..6f4f3958 100644
--- a/isisd/ChangeLog
+++ b/isisd/ChangeLog
@@ -1,3 +1,10 @@
+2005-04-02 Andrew J. Schorr <ajschorr@alumni.princeton.edu>
+
+	* isis_zebra.c: (isis_zebra_if_del) Call if_delete_retain instead
+	  of if_delete, since it is generally not safe to remove interface
+	  structures.  After deleting, set ifp->ifindex to IFINDEX_INTERNAL.
+	  (zebra_interface_if_lookup) Tighten up code.
+
 2005-03-07 Michael Sandee <voidptr@voidptr.sboost.org>
 
 	* isis_spf.c: host.name might be NULL.
diff --git a/isisd/isis_zebra.c b/isisd/isis_zebra.c
index 40743b29..0f8d1162 100644
--- a/isisd/isis_zebra.c
+++ b/isisd/isis_zebra.c
@@ -95,30 +95,28 @@ isis_zebra_if_del (int command, struct zclient *zclient, zebra_size_t length)
   zlog_debug ("Zebra I/F delete: %s index %d flags %ld metric %d mtu %d",
 	      ifp->name, ifp->ifindex, ifp->flags, ifp->metric, ifp->mtu);
 
-  if_delete (ifp);
+
+  /* Cannot call if_delete because we should retain the pseudo interface
+     in case there is configuration info attached to it. */
+  if_delete_retain(ifp);
 
   isis_csm_state_change (IF_DOWN_FROM_Z, circuit_scan_by_ifp (ifp), ifp);
 
+  ifp->ifindex = IFINDEX_INTERNAL;
+
   return 0;
 }
 
 static struct interface *
 zebra_interface_if_lookup (struct stream *s)
 {
-  struct interface *ifp;
   u_char ifname_tmp[INTERFACE_NAMSIZ];
 
   /* Read interface name. */
   stream_get (ifname_tmp, s, INTERFACE_NAMSIZ);
 
-  /* Lookup this by interface index. */
-  ifp = if_lookup_by_name ((char *) ifname_tmp);
-
-  /* If such interface does not exist, indicate an error */
-  if (!ifp)
-    return NULL;
-
-  return ifp;
+  /* And look it up. */
+  return if_lookup_by_name ((char *) ifname_tmp);
 }
 
 static int