[PtP over ethernet] New peer flag allows much more addressing flexibility

2006-12-12 Andrew J. Schorr <ajschorr@alumni.princeton.edu>

	* if.h: (struct connected) Add new ZEBRA_IFA_PEER flag indicating
	  whether a peer address has been configured.  Comment now shows
	  the new interpretation of the destination addr: if ZEBRA_IFA_PEER
	  is set, then it must contain the destination address, otherwise
	  it may contain the broadcast address or be NULL.
	  (CONNECTED_DEST_HOST,CONNECTED_POINTOPOINT_HOST) Remove obsolete
	  macros that were specific to IPv4 and not fully general.
	  (CONNECTED_PEER) New macro to check ZEBRA_IFA_PEER flag.
	  (CONNECTED_PREFIX) New macro giving the prefix to insert into
	  the RIB: if CONNECTED_PEER, then use the destination (peer) address,
	  else use the address field.
	  (CONNECTED_ID) New macro to come up with an identifying address
	  for the struct connected.
	* if.c: (if_lookup_address, connected_lookup_address) Streamline
	  logic with new CONNECTED_PREFIX macro.
	* prefix.h: (PREFIX_COPY_IPV4, PREFIX_COPY_IPV6) New macros
	  for better performance than the general prefix_copy function.
	* zclient.c: (zebra_interface_address_read) For non-null destination
	  addresses, set prefixlen to equal the address prefixlen.  This
	  is needed to get the new CONNECTED_PREFIX macro to work properly.
	* connected.c: (connected_up_ipv4, connected_down_ipv4,
	  connected_up_ipv6, connected_down_ipv6) Simplify logic using the
	  new CONNECTED_PREFIX macro.
	  (connected_add_ipv4) Set prefixlen in destination addresses (required
	  by the CONNECTED_PREFIX macro).  Use CONNECTED_PEER macro instead
	  of testing for IFF_POINTOPOINT.  Delete invalid warning message.
	  Warn about cases where the ZEBRA_IFA_PEER is set but no
	  destination address has been supplied (and turn off the flag).
	  (connected_add_ipv6) Add new flags argument so callers may set
	  the ZEBRA_IFA_PEER flag.  If peer/broadcast address satisfies
	  IN6_IS_ADDR_UNSPECIFIED, then reject it with a warning.
	  Set prefixlen in destination address so CONNECTED_PREFIX will work.
	* connected.h: (connected_add_ipv6) Add new flags argument so
	  callers may set the ZEBRA_IFA_PEER flag.
	* interface.c: (connected_dump_vty) Use CONNECTED_PEER macro
	  to decide whether the destination address is a peer or broadcast
	  address (instead of checking IFF_BROADCAST and IFF_POINTOPOINT).
	* if_ioctl.c: (if_getaddrs) Instead of setting a peer address
	  only when the IFF_POINTOPOINT is set, we now accept a peer
	  address whenever it is available and not the same as the local
	  address.  Otherwise (no peer address assigned), we check
	  for a broadcast address (regardless of the IFF_BROADCAST flag).
	  And must now pass a flags value of ZEBRA_IFA_PEER to
	  connected_add_ipv4 when a peer address is assigned.
	  The same new logic is used with the IPv6 code as well (and we
	  pass the new flags argument to connected_add_ipv6).
	  (if_get_addr) Do not bother to check IFF_POINTOPOINT: just
	  issue the SIOCGIFDSTADDR ioctl and see if we get back
	  a peer address not matching the local address (and set
	  the ZEBRA_IFA_PEER in that case).  If there's no peer address,
	  try to grab SIOCGIFBRDADDR regardless of whether IFF_BROADCAST is set.
	* if_ioctl_solaris.c: (if_get_addr) Just try the SIOCGLIFDSTADDR ioctl
	  without bothering to check the IFF_POINTOPOINT flag.  And if
	  no peer address was found, just try the SIOCGLIFBRDADDR ioctl
	  without checking the IFF_BROADCAST flag.  Call connected_add_ipv4
	  and connected_add_ipv6 with appropriate flags.
	* if_proc.c: (ifaddr_proc_ipv6) Must pass new flags argument to
	  connected_add_ipv6.
	* kernel_socket.c: (ifam_read) Must pass new flags argument to
	  connected_add_ipv6.
	* rt_netlink.c: (netlink_interface_addr) Copy logic from iproute2
	  to determine local and possible peer address (so there's no longer
	  a test for IFF_POINTOPOINT).  Set ZEBRA_IFA_PEER flag appropriately.
	  Pass new flags argument to connected_add_ipv6.
	  (netlink_address) Test !CONNECTED_PEER instead of if_is_broadcast
	  to determine whether the connected destination address is a
	  broadcast address.
	* bgp_nexthop.c: (bgp_connected_add, bgp_connected_delete)
	  Simplify logic by using new CONNECTED_PREFIX macro.
	* ospf_interface.c: (ospf_if_is_configured, ospf_if_lookup_by_prefix,
	  ospf_if_lookup_recv_if) Simplify logic using new CONNECTED_PREFIX
	  macro.
	* ospf_lsa.c: (lsa_link_ptop_set) Using the new CONNECTED_PREFIX
	  macro, both options collapse into the same code.
	* ospf_snmp.c: (ospf_snmp_if_update) Simplify logic using new
	  CONNECTED_ID macro.
	  (ospf_snmp_is_if_have_addr) Simplify logic using new CONNECTED_PREFIX
	  macro.
	* ospf_vty.c: (show_ip_ospf_interface_sub) Use new CONNECTED_PEER macro
	  instead of testing the IFF_POINTOPOINT flag.
	* ospfd.c: (ospf_network_match_iface) Use new CONNECTED_PEER macro
	  instead of testing with if_is_pointopoint.  And add commented-out
	  code to implement alternative (in my opinion) more elegant behavior
	  that has no special-case treatment for PtP addresses.
	  (ospf_network_run) Use new CONNECTED_ID macro to simplify logic.
	* rip_interface.c: (rip_interface_multicast_set) Use new CONNECTED_ID
	  macro to simplify logic.
	  (rip_request_interface_send) Fix minor bug: ipv4_broadcast_addr does
	  not give a useful result if prefixlen is 32 (we require a peer
	  address in such cases).
	* ripd.c: (rip_update_interface) Fix same bug as above.

3 files changed, 23 insertions, 14 deletions

diff --git a/ripd/ChangeLog b/ripd/ChangeLog
index 68813f14..ba13a595 100644
--- a/ripd/ChangeLog
+++ b/ripd/ChangeLog
@@ -1,3 +1,12 @@
+2006-12-12 Andrew J. Schorr <ajschorr@alumni.princeton.edu>
+
+	* rip_interface.c: (rip_interface_multicast_set) Use new CONNECTED_ID
+	  macro to simplify logic.
+	  (rip_request_interface_send) Fix minor bug: ipv4_broadcast_addr does
+	  not give a useful result if prefixlen is 32 (we require a peer
+	  address in such cases).
+	* ripd.c: (rip_update_interface) Fix same bug as above.
+
 2006-09-11 Paul Jakma <paul.jakma@sun.com>
 
 	* ripd.c: (rip_read) remove gratuitous use of mid-function
diff --git a/ripd/rip_interface.c b/ripd/rip_interface.c
index a5b12db6..c8a1a84f 100644
--- a/ripd/rip_interface.c
+++ b/ripd/rip_interface.c
@@ -141,16 +141,10 @@ void
 rip_interface_multicast_set (int sock, struct connected *connected)
 {
   struct in_addr addr;
-  struct prefix_ipv4 *p;
   
   assert (connected != NULL);
   
-  if (if_is_pointopoint(connected->ifp) && CONNECTED_DEST_HOST(connected))
-    p = (struct prefix_ipv4 *) connected->destination;
-  else
-    p = (struct prefix_ipv4 *) connected->address;
-  
-  addr = p->prefix;
+  addr = CONNECTED_ID(connected)->u.prefix4;
 
   if (setsockopt_multicast_ipv4 (sock, IP_MULTICAST_IF, addr, 0, 
                                  connected->ifp->ifindex) < 0) 
@@ -197,13 +191,16 @@ rip_request_interface_send (struct interface *ifp, u_char version)
 	      memset (&to, 0, sizeof (struct sockaddr_in));
 	      to.sin_port = htons (RIP_PORT_DEFAULT);
               if (connected->destination)
-                /* use specified broadcast or point-to-point destination addr */
+                /* use specified broadcast or peer destination addr */
                 to.sin_addr = connected->destination->u.prefix4;
-              else
+              else if (connected->address->prefixlen < IPV4_MAX_PREFIXLEN)
 	        /* calculate the appropriate broadcast address */
                 to.sin_addr.s_addr =
 		  ipv4_broadcast_addr(connected->address->u.prefix4.s_addr,
 				      connected->address->prefixlen);
+	      else
+		/* do not know where to send the packet */
+	        continue;
 
 	      if (IS_RIP_DEBUG_EVENT)
 		zlog_debug ("SEND request to %s", inet_ntoa (to.sin_addr));
diff --git a/ripd/ripd.c b/ripd/ripd.c
index a1630f6c..afa49fd6 100644
--- a/ripd/ripd.c
+++ b/ripd/ripd.c
@@ -2449,19 +2449,22 @@ rip_update_interface (struct connected *ifc, u_char version, int route_type)
           /* Destination address and port setting. */
           memset (&to, 0, sizeof (struct sockaddr_in));
           if (ifc->destination)
-            /* use specified broadcast or point-to-point destination addr */
+            /* use specified broadcast or peer destination addr */
             to.sin_addr = ifc->destination->u.prefix4;
-          else
+          else if (ifc->address->prefixlen < IPV4_MAX_PREFIXLEN)
             /* calculate the appropriate broadcast address */
             to.sin_addr.s_addr =
               ipv4_broadcast_addr(ifc->address->u.prefix4.s_addr,
                                   ifc->address->prefixlen);
+	  else
+	    /* do not know where to send the packet */
+	    return;
           to.sin_port = htons (RIP_PORT_DEFAULT);
 
           if (IS_RIP_DEBUG_EVENT)
-            zlog_debug ("%s announce to %s on %s",
-                       if_is_pointopoint (ifc->ifp) ? "unicast" : "broadcast",
-                       inet_ntoa (to.sin_addr), ifc->ifp->name);
+            zlog_debug("%s announce to %s on %s",
+		       CONNECTED_PEER(ifc) ? "unicast" : "broadcast",
+		       inet_ntoa (to.sin_addr), ifc->ifp->name);
 
           rip_output_process (ifc, &to, route_type, version);
         }