[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.

1 files changed, 43 insertions, 38 deletions

diff --git a/zebra/if_ioctl.c b/zebra/if_ioctl.c
index 788184f8..f357e154 100644
--- a/zebra/if_ioctl.c
+++ b/zebra/if_ioctl.c
@@ -249,6 +249,7 @@ if_getaddrs (void)
 	  struct sockaddr_in *mask;
 	  struct sockaddr_in *dest;
 	  struct in_addr *dest_pnt;
+	  int flags = 0;
 
 	  addr = (struct sockaddr_in *) ifap->ifa_addr;
 	  mask = (struct sockaddr_in *) ifap->ifa_netmask;
@@ -256,19 +257,25 @@ if_getaddrs (void)
 
 	  dest_pnt = NULL;
 
-	  if (ifap->ifa_flags & IFF_POINTOPOINT) 
+	  if (ifap->ifa_dstaddr &&
+	      !IPV4_ADDR_SAME(&addr->sin_addr,
+			      &((struct sockaddr_in *)
+			      	ifap->ifa_dstaddr)->sin_addr))
 	    {
 	      dest = (struct sockaddr_in *) ifap->ifa_dstaddr;
 	      dest_pnt = &dest->sin_addr;
+	      flags = ZEBRA_IFA_PEER;
 	    }
-
-	  if (ifap->ifa_flags & IFF_BROADCAST)
+	  else if (ifap->ifa_broadaddr &&
+		   !IPV4_ADDR_SAME(&addr->sin_addr,
+				   &((struct sockaddr_in *)
+				     ifap->ifa_broadaddr)->sin_addr))
 	    {
 	      dest = (struct sockaddr_in *) ifap->ifa_broadaddr;
 	      dest_pnt = &dest->sin_addr;
 	    }
 
-	  connected_add_ipv4 (ifp, 0, &addr->sin_addr,
+	  connected_add_ipv4 (ifp, flags, &addr->sin_addr,
 			      prefixlen, dest_pnt, NULL);
 	}
 #ifdef HAVE_IPV6
@@ -278,6 +285,7 @@ if_getaddrs (void)
 	  struct sockaddr_in6 *mask;
 	  struct sockaddr_in6 *dest;
 	  struct in6_addr *dest_pnt;
+	  int flags = 0;
 
 	  addr = (struct sockaddr_in6 *) ifap->ifa_addr;
 	  mask = (struct sockaddr_in6 *) ifap->ifa_netmask;
@@ -285,22 +293,22 @@ if_getaddrs (void)
 
 	  dest_pnt = NULL;
 
-	  if (ifap->ifa_flags & IFF_POINTOPOINT) 
+	  if (ifap->ifa_dstaddr &&
+	      !IPV6_ADDR_SAME(&addr->sin6_addr,
+			      &((struct sockaddr_in6 *)
+			      	ifap->ifa_dstaddr)->sin6_addr))
 	    {
-	      if (ifap->ifa_dstaddr)
-		{
-		  dest = (struct sockaddr_in6 *) ifap->ifa_dstaddr;
-		  dest_pnt = &dest->sin6_addr;
-		}
+	      dest = (struct sockaddr_in6 *) ifap->ifa_dstaddr;
+	      dest_pnt = &dest->sin6_addr;
+	      flags = ZEBRA_IFA_PEER;
 	    }
-
-	  if (ifap->ifa_flags & IFF_BROADCAST)
+	  else if (ifap->ifa_broadaddr &&
+		   !IPV6_ADDR_SAME(&addr->sin6_addr,
+				   &((struct sockaddr_in6 *)
+				     ifap->ifa_broadaddr)->sin6_addr))
 	    {
-	      if (ifap->ifa_broadaddr)
-		{
-		  dest = (struct sockaddr_in6 *) ifap->ifa_broadaddr;
-		  dest_pnt = &dest->sin6_addr;
-		}
+	      dest = (struct sockaddr_in6 *) ifap->ifa_broadaddr;
+	      dest_pnt = &dest->sin6_addr;
 	    }
 
 #if defined(KAME)
@@ -312,7 +320,7 @@ if_getaddrs (void)
 	    }	
 #endif          
 
-	  connected_add_ipv6 (ifp, &addr->sin6_addr, prefixlen, 
+	  connected_add_ipv6 (ifp, flags, &addr->sin6_addr, prefixlen, 
 	                      dest_pnt, NULL);
 	}
 #endif /* HAVE_IPV6 */
@@ -335,6 +343,7 @@ if_get_addr (struct interface *ifp)
   struct sockaddr_in dest;
   struct in_addr *dest_pnt;
   u_char prefixlen;
+  int flags = 0;
 
   /* Interface's name and address family. */
   strncpy (ifreq.ifr_name, ifp->name, IFNAMSIZ);
@@ -374,40 +383,36 @@ if_get_addr (struct interface *ifp)
   /* Point to point or borad cast address pointer init. */
   dest_pnt = NULL;
 
-  if (ifp->flags & IFF_POINTOPOINT) 
+  ret = if_ioctl (SIOCGIFDSTADDR, (caddr_t) &ifreq);
+  if (ret < 0) 
+    {
+      if (errno != EADDRNOTAVAIL) 
+	zlog_warn ("SIOCGIFDSTADDR fail: %s", safe_strerror (errno));
+    }
+  else if (!IPV4_ADDR_SAME(&addr.sin_addr, &ifreq.ifr_dstaddr.sin_addr))
     {
-      ret = if_ioctl (SIOCGIFDSTADDR, (caddr_t) &ifreq);
-      if (ret < 0) 
-	{
-	  if (errno != EADDRNOTAVAIL) 
-	    {
-	      zlog_warn ("SIOCGIFDSTADDR fail: %s", safe_strerror (errno));
-	      return ret;
-	    }
-	  return 0;
-	}
       memcpy (&dest, &ifreq.ifr_dstaddr, sizeof (struct sockaddr_in));
       dest_pnt = &dest.sin_addr;
+      flags = ZEBRA_IFA_PEER;
     }
-  if (ifp->flags & IFF_BROADCAST)
+  if (!dest_pnt)
     {
       ret = if_ioctl (SIOCGIFBRDADDR, (caddr_t) &ifreq);
       if (ret < 0) 
 	{
 	  if (errno != EADDRNOTAVAIL) 
-	    {
-	      zlog_warn ("SIOCGIFBRDADDR fail: %s", safe_strerror (errno));
-	      return ret;
-	    }
-	  return 0;
+	    zlog_warn ("SIOCGIFBRDADDR fail: %s", safe_strerror (errno));
 	}
-      memcpy (&dest, &ifreq.ifr_broadaddr, sizeof (struct sockaddr_in));
-      dest_pnt = &dest.sin_addr;
+      else if (!IPV4_ADDR_SAME(&addr.sin_addr, &ifreq.ifr_broadaddr.sin_addr))
+        {
+	  memcpy (&dest, &ifreq.ifr_broadaddr, sizeof (struct sockaddr_in));
+	  dest_pnt = &dest.sin_addr;
+        }
     }
 
 
   /* Set address to the interface. */
-  connected_add_ipv4 (ifp, 0, &addr.sin_addr, prefixlen, dest_pnt, NULL);
+  connected_add_ipv4 (ifp, flags, &addr.sin_addr, prefixlen, dest_pnt, NULL);
 
   return 0;
 }