[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, 89 deletions

diff --git a/zebra/connected.c b/zebra/connected.c
index 44002e76..3fe9717d 100644
--- a/zebra/connected.c
+++ b/zebra/connected.c
@@ -173,24 +173,11 @@ void
 connected_up_ipv4 (struct interface *ifp, struct connected *ifc)
 {
   struct prefix_ipv4 p;
-  struct prefix_ipv4 *addr;
-  struct prefix_ipv4 *dest;
 
   if (! CHECK_FLAG (ifc->conf, ZEBRA_IFC_REAL))
     return;
 
-  addr = (struct prefix_ipv4 *) ifc->address;
-  dest = (struct prefix_ipv4 *) ifc->destination;
-
-  memset (&p, 0, sizeof (struct prefix_ipv4));
-  p.family = AF_INET;
-  p.prefixlen = addr->prefixlen;
-
-  /* Point-to-point check. */
-  if (CONNECTED_POINTOPOINT_HOST(ifc))
-    p.prefix = dest->prefix;
-  else
-    p.prefix = addr->prefix;
+  PREFIX_COPY_IPV4(&p, CONNECTED_PREFIX(ifc));
 
   /* Apply mask to the network. */
   apply_mask_ipv4 (&p);
@@ -227,33 +214,22 @@ connected_add_ipv4 (struct interface *ifp, int flags, struct in_addr *addr,
   p->prefixlen = prefixlen;
   ifc->address = (struct prefix *) p;
   
-  /* If there is broadcast or pointopoint address. */
+  /* If there is broadcast or peer address. */
   if (broad)
     {
       p = prefix_ipv4_new ();
       p->family = AF_INET;
       p->prefix = *broad;
+      p->prefixlen = prefixlen;
       ifc->destination = (struct prefix *) p;
 
       /* validate the destination address */
-      if (ifp->flags & IFF_POINTOPOINT)
+      if (CONNECTED_PEER(ifc))
         {
 	  if (IPV4_ADDR_SAME(addr,broad))
-	    zlog_warn("warning: PtP interface %s has same local and peer "
+	    zlog_warn("warning: interface %s has same local and peer "
 		      "address %s, routing protocols may malfunction",
 		      ifp->name,inet_ntoa(*addr));
-	  else if ((prefixlen != IPV4_MAX_PREFIXLEN) &&
-	   	   (ipv4_network_addr(addr->s_addr,prefixlen) !=
-	   	    ipv4_network_addr(broad->s_addr,prefixlen)))
-	    {
-	      char buf[2][INET_ADDRSTRLEN];
-	      zlog_warn("warning: PtP interface %s network mismatch: local "
-	      		"%s/%d vs. peer %s, routing protocols may malfunction",
-	    		ifp->name,
-			inet_ntop (AF_INET, addr, buf[0], sizeof(buf[0])),
-			prefixlen,
-			inet_ntop (AF_INET, broad, buf[1], sizeof(buf[1])));
-	    }
         }
       else
         {
@@ -273,10 +249,20 @@ connected_add_ipv4 (struct interface *ifp, int flags, struct in_addr *addr,
 
     }
   else
-    /* no broadcast or destination address was supplied */
-    if ((prefixlen == IPV4_MAX_PREFIXLEN) && if_is_pointopoint(ifp))
-      zlog_warn("warning: PtP interface %s with addr %s/%d needs a "
-      		"peer address",ifp->name,inet_ntoa(*addr),prefixlen);
+    {
+      if (CHECK_FLAG(ifc->flags, ZEBRA_IFA_PEER))
+        {
+	  zlog_warn("warning: %s called for interface %s "
+		    "with peer flag set, but no peer address supplied",
+		    __func__, ifp->name);
+	  UNSET_FLAG(ifc->flags, ZEBRA_IFA_PEER);
+	}
+
+      /* no broadcast or destination address was supplied */
+      if ((prefixlen == IPV4_MAX_PREFIXLEN) && if_is_pointopoint(ifp))
+	zlog_warn("warning: PtP interface %s with addr %s/%d needs a "
+		  "peer address",ifp->name,inet_ntoa(*addr),prefixlen);
+    }
 
   /* Label of this address. */
   if (label)
@@ -293,24 +279,11 @@ void
 connected_down_ipv4 (struct interface *ifp, struct connected *ifc)
 {
   struct prefix_ipv4 p;
-  struct prefix_ipv4 *addr;
-  struct prefix_ipv4 *dest;
 
   if (! CHECK_FLAG (ifc->conf, ZEBRA_IFC_REAL))
     return;
 
-  addr = (struct prefix_ipv4 *)ifc->address;
-  dest = (struct prefix_ipv4 *)ifc->destination;
-
-  memset (&p, 0, sizeof (struct prefix_ipv4));
-  p.family = AF_INET;
-  p.prefixlen = addr->prefixlen;
-
-  /* Point-to-point check. */
-  if (CONNECTED_POINTOPOINT_HOST(ifc))
-    p.prefix = dest->prefix;
-  else
-    p.prefix = addr->prefix;
+  PREFIX_COPY_IPV4(&p, CONNECTED_PREFIX(ifc));
 
   /* Apply mask to the network. */
   apply_mask_ipv4 (&p);
@@ -350,28 +323,11 @@ void
 connected_up_ipv6 (struct interface *ifp, struct connected *ifc)
 {
   struct prefix_ipv6 p;
-  struct prefix_ipv6 *addr;
-  struct prefix_ipv6 *dest;
 
   if (! CHECK_FLAG (ifc->conf, ZEBRA_IFC_REAL))
     return;
 
-  addr = (struct prefix_ipv6 *) ifc->address;
-  dest = (struct prefix_ipv6 *) ifc->destination;
-
-  memset (&p, 0, sizeof (struct prefix_ipv6));
-  p.family = AF_INET6;
-  p.prefixlen = addr->prefixlen;
-
-  if (if_is_pointopoint (ifp) && dest)
-    {
-      if (IN6_IS_ADDR_UNSPECIFIED (&dest->prefix))
-	p.prefix = addr->prefix;
-      else
-	p.prefix = dest->prefix;
-    }
-  else
-    p.prefix = addr->prefix;
+  PREFIX_COPY_IPV6(&p, CONNECTED_PREFIX(ifc));
 
   /* Apply mask to the network. */
   apply_mask_ipv6 (&p);
@@ -390,7 +346,7 @@ connected_up_ipv6 (struct interface *ifp, struct connected *ifc)
 
 /* Add connected IPv6 route to the interface. */
 void
-connected_add_ipv6 (struct interface *ifp, struct in6_addr *addr,
+connected_add_ipv6 (struct interface *ifp, int flags, struct in6_addr *addr,
 		    u_char prefixlen, struct in6_addr *broad,
 		    const char *label)
 {
@@ -400,6 +356,7 @@ connected_add_ipv6 (struct interface *ifp, struct in6_addr *addr,
   /* Make connected structure. */
   ifc = connected_new ();
   ifc->ifp = ifp;
+  ifc->flags = flags;
 
   /* Allocate new connected address. */
   p = prefix_ipv6_new ();
@@ -408,13 +365,27 @@ connected_add_ipv6 (struct interface *ifp, struct in6_addr *addr,
   p->prefixlen = prefixlen;
   ifc->address = (struct prefix *) p;
 
-  /* If there is broadcast or pointopoint address. */
+  /* If there is broadcast or peer address. */
   if (broad)
     {
-      p = prefix_ipv6_new ();
-      p->family = AF_INET6;
-      IPV6_ADDR_COPY (&p->prefix, broad);
-      ifc->destination = (struct prefix *) p;
+      if (IN6_IS_ADDR_UNSPECIFIED(broad))
+	zlog_warn("warning: %s called for interface %s with unspecified "
+		  "destination address; ignoring!", __func__, ifp->name);
+      else
+	{
+	  p = prefix_ipv6_new ();
+	  p->family = AF_INET6;
+	  IPV6_ADDR_COPY (&p->prefix, broad);
+	  p->prefixlen = prefixlen;
+	  ifc->destination = (struct prefix *) p;
+	}
+    }
+  if (CHECK_FLAG(ifc->flags, ZEBRA_IFA_PEER) && !ifc->destination)
+    {
+      zlog_warn("warning: %s called for interface %s "
+		"with peer flag set, but no peer address supplied",
+		__func__, ifp->name);
+      UNSET_FLAG(ifc->flags, ZEBRA_IFA_PEER);
     }
 
   /* Label of this address. */
@@ -431,28 +402,11 @@ void
 connected_down_ipv6 (struct interface *ifp, struct connected *ifc)
 {
   struct prefix_ipv6 p;
-  struct prefix_ipv6 *addr;
-  struct prefix_ipv6 *dest;
 
   if (! CHECK_FLAG (ifc->conf, ZEBRA_IFC_REAL))
     return;
 
-  addr = (struct prefix_ipv6 *) ifc->address;
-  dest = (struct prefix_ipv6 *) ifc->destination;
-
-  memset (&p, 0, sizeof (struct prefix_ipv6));
-  p.family = AF_INET6;
-  p.prefixlen = addr->prefixlen;
-
-  if (if_is_pointopoint (ifp) && dest)
-    {
-      if (IN6_IS_ADDR_UNSPECIFIED (&dest->prefix))
-	p.prefix = addr->prefix;
-      else
-	p.prefix = dest->prefix;
-    }
-  else
-    p.prefix = addr->prefix;
+  PREFIX_COPY_IPV6(&p, CONNECTED_PREFIX(ifc));
 
   apply_mask_ipv6 (&p);