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.

4 files changed, 69 insertions, 43 deletions

diff --git a/zebra/ChangeLog b/zebra/ChangeLog
index 150c08a3..572d2687 100644
--- a/zebra/ChangeLog
+++ b/zebra/ChangeLog
@@ -1,3 +1,22 @@
+2005-04-02 Andrew J. Schorr <ajschorr@alumni.princeton.edu>
+
+	* 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.
+
 2005-03-31 Hasso Tepper <hasso at quagga.net>
 
 	* rt_netlink.c (netlink_talk_filter): Show always warning message,
diff --git a/zebra/interface.c b/zebra/interface.c
index 55717545..0f294a56 100644
--- a/zebra/interface.c
+++ b/zebra/interface.c
@@ -40,27 +40,7 @@
 #include "zebra/redistribute.h"
 #include "zebra/debug.h"
 #include "zebra/irdp.h"
-
-/* Allocate a new internal interface index 
- * This works done from the top so that %d macros
- * print a - sign! 
- */
-static unsigned int
-if_new_intern_ifindex (void)
-{
-  /* Start here so that first one assigned is 0xFFFFFFFF */
-  static unsigned int ifindex = IFINDEX_INTERNBASE + 1;
-
-  for (;;) 
-    {
-      ifindex--;
-      if ( ifindex <= IFINDEX_INTERNBASE )
-       ifindex = 0xFFFFFFFF;
 
-      if (if_lookup_by_index(ifindex) == NULL)
-       return ifindex;
-    }
-}
 
 /* Called when new interface is added. */
 int
@@ -418,6 +398,13 @@ if_delete_update (struct interface *ifp)
 	}
     }
   zebra_interface_delete_update (ifp);
+
+  /* Update ifindex after distributing the delete message.  This is in
+     case any client needs to have the old value of ifindex available
+     while processing the deletion.  Each client daemon is responsible
+     for setting ifindex to IFINDEX_INTERNAL after processing the
+     interface deletion message. */
+  ifp->ifindex = IFINDEX_INTERNAL;
 }
 #endif /* (defined(RTM_IFANNOUNCE) || defined(HAVE_NETLINK) */
 
@@ -680,9 +667,9 @@ if_dump_vty (struct vty *vty, struct interface *ifp)
   if (ifp->desc)
     vty_out (vty, "  Description: %s%s", ifp->desc,
 	     VTY_NEWLINE);
-  if (ifp->ifindex <= 0)
+  if (ifp->ifindex == IFINDEX_INTERNAL)
     {
-      vty_out(vty, "  index %d pseudo interface%s", ifp->ifindex, VTY_NEWLINE);
+      vty_out(vty, "  pseudo interface%s", VTY_NEWLINE);
       return;
     }
   else if (! CHECK_FLAG (ifp->status, ZEBRA_INTERFACE_ACTIVE))
@@ -861,17 +848,15 @@ DEFUN_NOSH (zebra_interface,
   struct interface * ifp;
   
   /* Call lib interface() */
-  ret = interface_cmd.func (self, vty, argc, argv);
+  if ((ret = interface_cmd.func (self, vty, argc, argv)) != CMD_SUCCESS)
+    return ret;
 
   ifp = vty->index;  
 
-  /* Set ifindex 
-     this only happens if interface is NOT in kernel */
-  if (ifp->ifindex == 0)
-    {
-      ifp->ifindex = if_new_intern_ifindex ();
-      UNSET_FLAG (ifp->status, ZEBRA_INTERFACE_ACTIVE);
-    }
+  if (ifp->ifindex == IFINDEX_INTERNAL)
+    /* Is this really necessary?  Shouldn't status be initialized to 0
+       in that case? */
+    UNSET_FLAG (ifp->status, ZEBRA_INTERFACE_ACTIVE);
 
   return ret;
 }
diff --git a/zebra/kernel_socket.c b/zebra/kernel_socket.c
index e6e74449..cdc6822c 100644
--- a/zebra/kernel_socket.c
+++ b/zebra/kernel_socket.c
@@ -301,8 +301,8 @@ ifm_read (struct if_msghdr *ifm)
    * If lookup by index was unsuccessful and we have a name, try
    * looking up by name.  Interfaces specified in the configuration
    * file for which the ifindex has not been determined will have
-   * ifindex == -1, and such interfaces are found by this search, and
-   * then their ifindex values can be filled in.
+   * ifindex == IFINDEX_INTERNAL, and such interfaces are found by this search,
+   * and then their ifindex values can be filled in.
    */
   if (ifp == NULL && sdl != NULL)
     {
@@ -322,14 +322,10 @@ ifm_read (struct if_msghdr *ifm)
     }
 
   /*
-   * If ifp does not exist or has an invalid index (-1), create or
+   * If ifp does not exist or has an invalid index (IFINDEX_INTERNAL), create or
    * fill in an interface.
    */
-  /*
-   * XXX warning: comparison between signed and unsigned
-   * ifindex should probably be signed
-   */
-  if ((ifp == NULL) || (ifp->ifindex == -1))
+  if ((ifp == NULL) || (ifp->ifindex == IFINDEX_INTERNAL))
     {
       /*
        * To create or fill in an interface, a sockaddr_dl (via
@@ -348,7 +344,7 @@ ifm_read (struct if_msghdr *ifm)
 
       /* 
        * Fill in newly created interface structure, or larval
-       * structure with ifindex -1.
+       * structure with ifindex IFINDEX_INTERNAL.
        */
       ifp->ifindex = ifm->ifm_index;
       ifp->flags = ifm->ifm_flags;
diff --git a/zebra/rt_netlink.c b/zebra/rt_netlink.c
index 042ee331..b3b2aab5 100644
--- a/zebra/rt_netlink.c
+++ b/zebra/rt_netlink.c
@@ -86,6 +86,33 @@ extern struct zebra_privs_t zserv_privs;
 
 extern u_int32_t nl_rcvbufsize;
 
+/* Note: on netlink systems, there should be a 1-to-1 mapping between interface
+   names and ifindex values. */
+static void
+set_ifindex(struct interface *ifp, unsigned int ifi_index)
+{
+  struct interface *oifp;
+
+  if (((oifp = if_lookup_by_index(ifi_index)) != NULL) && (oifp != ifp))
+    {
+      if (ifi_index == IFINDEX_INTERNAL)
+        zlog_err("Netlink is setting interface %s ifindex to reserved "
+		 "internal value %u", ifp->name, ifi_index);
+      else
+        {
+	  if (IS_ZEBRA_DEBUG_KERNEL)
+	    zlog_debug("interface index %d was renamed from %s to %s",
+	    	       ifi_index, oifp->name, ifp->name);
+	  if (if_is_up(oifp))
+	    zlog_err("interface rename detected on up interface: index %d "
+		     "was renamed from %s to %s, results are uncertain!", 
+	    	     ifi_index, oifp->name, ifp->name);
+	  if_delete_update(oifp);
+        }
+    }
+  ifp->ifindex = ifi_index;
+}
+
 /* Make socket for Linux netlink interface. */
 static int
 netlink_socket (struct nlsock *nl, unsigned long groups)
@@ -504,8 +531,7 @@ netlink_interface (struct sockaddr_nl *snl, struct nlmsghdr *h)
 
   /* Add interface. */
   ifp = if_get_by_name (name);
-
-  ifp->ifindex = ifi->ifi_index;
+  set_ifindex(ifp, ifi->ifi_index);
   ifp->flags = ifi->ifi_flags & 0x0000fffff;
   ifp->mtu6 = ifp->mtu = *(int *) RTA_DATA (tb[IFLA_MTU]);
   ifp->metric = 1;
@@ -981,7 +1007,7 @@ netlink_link_change (struct sockaddr_nl *snl, struct nlmsghdr *h)
           if (ifp == NULL)
             ifp = if_get_by_name (name);
 
-          ifp->ifindex = ifi->ifi_index;
+          set_ifindex(ifp, ifi->ifi_index);
           ifp->flags = ifi->ifi_flags & 0x0000fffff;
           ifp->mtu6 = ifp->mtu = *(int *) RTA_DATA (tb[IFLA_MTU]);
           ifp->metric = 1;
@@ -992,7 +1018,7 @@ netlink_link_change (struct sockaddr_nl *snl, struct nlmsghdr *h)
       else
         {
           /* Interface status change. */
-          ifp->ifindex = ifi->ifi_index;
+          set_ifindex(ifp, ifi->ifi_index);
           ifp->mtu6 = ifp->mtu = *(int *) RTA_DATA (tb[IFLA_MTU]);
           ifp->metric = 1;