[quagga-dev 803] Re: ripd fixes [was Re: ripd status]

sowmini.varadhan at Sun.COM sowmini.varadhan at Sun.COM
Wed Jan 21 19:14:53 GMT 2004


> 
>   Actually, I'm not really sure (I'll re-check) that the RIP spec
>   mandates anything here. The ZEBRA_IFA_SECONDARY is the common-sense
>   way to play with other RIPpers on the link (don't try to pretend
>   to be N nodes, just because you happen to be hogging N addresses on
>   that subnet), but I don't think it's a violation of the spec to 
>   send the packet either.
> 
> OK, well that belongs in a comment; it is certainly non-obvious what's
> going on.
> 

Ok, here goes:
---------------------------------------------------------------------------
The changes are:

- rip_interface.c: obsolete unbind code in rip_interface_multicast_set, 
  and instead do the more portable (though slower) method of creating a 
  socket for each outgoing packet and binding the source address on the 
  new socket.
- rip_interface.c, ripd.c, ripd.h: Modify rip_request_send so that source 
  address is determined by the caller of rip_request_send for 
  ripv1  packets and non-multicast interfaces (rip_request_send loops 
  over all connected address in all other cases).
- ripd.c/rip_send_packet: don't send packets with source set to 
  ZEBRA_IFA_SECONDARY connected addresses; improved debug messages; 


===================================================================
RCS file: ripd.c,v
retrieving revision 1.13
retrieving revision 1.14
diff -uwb -r1.13 -r1.14
--- /tmp/T0VEWkgj	Wed Jan 21 14:11:02 2004
+++ /tmp/T1WEWkgj	Wed Jan 21 14:11:02 2004
@@ -61,7 +61,7 @@
 
 void rip_output_process (struct interface *, struct prefix *,
 			 struct sockaddr_in *, int, u_char, 
-                         struct prefix_ipv4 *);
+                         struct connected *, struct prefix_ipv4 *);
 
 /* RIP output routes type. */
 enum
@@ -1235,11 +1235,44 @@
 /* RIP packet send to destination address. */
 int
 rip_send_packet (caddr_t buf, int size, struct sockaddr_in *to, 
-		 struct interface *ifp)
+		 struct interface *ifp, struct connected *connected)
 {
-  int ret;
+  int ret, send_sock;
   struct sockaddr_in sin;
 
+  if (IS_RIP_DEBUG_PACKET)
+    {
+      char dst[20];
+      if (to)
+        {
+          strcpy(dst, inet_ntoa(to->sin_addr));
+        }
+      else
+        {
+          sin.sin_addr.s_addr = htonl (INADDR_RIP_GROUP);
+          strcpy(dst, inet_ntoa(sin.sin_addr));
+        }
+      zlog_info("rip_send_packet %s > %s (%s)",
+                inet_ntoa(connected->address->u.prefix4), dst, ifp->name);
+    }
+  if (connected->flags & ZEBRA_IFA_SECONDARY)
+    {
+      /*
+       * ZEBRA_IFA_SECONDARY is set on linux when an interface is configured
+       * with multiple addresses on the same subnet: the first address
+       * on the subnet is configured "primary", and all subsequent addresses
+       * on that subnet are treated as "secondary" addresses. 
+       * In order to avoid routing-table bloat on other rip listeners, 
+       * we do not send out RIP packets with ZEBRA_IFA_SECONDARY source addrs.
+       * XXX Since Linux is the only system for which the ZEBRA_IFA_SECONDARY
+       * flag is set, we would end up sending a packet for a "secondary"
+       * source address on non-linux systems.  
+       */
+      if (IS_RIP_DEBUG_PACKET)
+        zlog_info("duplicate dropped");
+      return 0;
+    }
+
   /* Make destination address. */
   memset (&sin, 0, sizeof (struct sockaddr_in));
   sin.sin_family = AF_INET;
@@ -1252,6 +1285,7 @@
     {
       sin.sin_port = to->sin_port;
       sin.sin_addr = to->sin_addr;
+      send_sock = rip->sock;
     }
   else
     {
@@ -1259,11 +1293,28 @@
       sin.sin_port = htons (RIP_PORT_DEFAULT);
       sin.sin_addr.s_addr = htonl (INADDR_RIP_GROUP);
 
-      /* caller has set multicast interface */
-
+      /*
+       * we have to open a new socket for each packet because this
+       * is the most portable way to bind to a different source
+       * ipv4 address for each packet. 
+       */
+      send_sock = socket(AF_INET, SOCK_DGRAM, 0);
+      if (send_sock < 0)
+        {
+          zlog_warn("rip_send_packet could not create socket %s",
+                    strerror(errno));
+          return -1;
     }
+      sockopt_broadcast (send_sock);
+      sockopt_reuseaddr (send_sock);
+      sockopt_reuseport (send_sock);
+#ifdef RIP_RECVMSG
+      setsockopt_pktinfo (send_sock);
+#endif /* RIP_RECVMSG */
+      rip_interface_multicast_set(send_sock, connected, if_is_pointopoint(ifp));
+    }
 
-  ret = sendto (rip->sock, buf, size, 0, (struct sockaddr *)&sin,
+  ret = sendto (send_sock, buf, size, 0, (struct sockaddr *)&sin,
 		sizeof (struct sockaddr_in));
 
   if (IS_RIP_DEBUG_EVENT)
@@ -1273,6 +1324,9 @@
   if (ret < 0)
     zlog_warn ("can't send packet : %s", strerror (errno));
 
+  if (!to)
+    close(send_sock);
+
   return ret;
 }
 
@@ -1456,7 +1510,7 @@
 
       /* All route with split horizon */
       rip_output_process (ifp, NULL, from, rip_all_route, packet->version, 
-                          &saddr);
+                          NULL, &saddr);
     }
   else
     {
@@ -1488,7 +1542,7 @@
 	}
       packet->command = RIP_RESPONSE;
 
-      rip_send_packet ((caddr_t) packet, size, from, ifp);
+      rip_send_packet ((caddr_t) packet, size, from, ifp, NULL);
     }
   rip_global_queries++;
 }
@@ -1983,7 +2037,7 @@
 void
 rip_output_process (struct interface *ifp, struct prefix *ifaddr,
 		    struct sockaddr_in *to, int route_type, u_char version,
-                    struct prefix_ipv4 *saddr)
+                    struct connected *connected, struct prefix_ipv4 *saddr)
 {
   int ret;
   struct stream *s;
@@ -2243,7 +2297,7 @@
 	      rip_auth_md5_set (s, ifp);
 
 	    ret = rip_send_packet (STREAM_DATA (s), stream_get_endp (s),
-				   to, ifp);
+				   to, ifp, connected);
 
 	    if (ret >= 0 && IS_RIP_DEBUG_SEND)
 	      rip_packet_dump ((struct rip_packet *)STREAM_DATA (s),
@@ -2259,7 +2313,8 @@
       if (version == RIPv2 && ri->auth_type == RIP_AUTH_MD5)
 	rip_auth_md5_set (s, ifp);
 
-      ret = rip_send_packet (STREAM_DATA (s), stream_get_endp (s), to, ifp);
+      ret = rip_send_packet (STREAM_DATA (s), stream_get_endp (s), to, ifp, 
+			     connected);
 
       if (ret >= 0 && IS_RIP_DEBUG_SEND)
 	rip_packet_dump ((struct rip_packet *)STREAM_DATA (s),
@@ -2275,12 +2330,13 @@
 /* Send RIP packet to the interface. */
 void
 rip_update_interface (struct interface *ifp, u_char version, int route_type,
-                      struct prefix_ipv4 *saddr)
+                      struct connected *sconn)
 {
   struct prefix_ipv4 *p;
   struct connected *connected;
   listnode node;
   struct sockaddr_in to;
+  struct prefix_ipv4 *saddr = (struct prefix_ipv4 *) sconn->address;
 
   /* When RIP version is 2 and multicast enable interface. */
   if (version == RIPv2 && if_is_multicast (ifp)) 
@@ -2289,7 +2345,7 @@
 	zlog_info ("multicast announce on %s ", ifp->name);
 
       rip_output_process (ifp, NULL, NULL, route_type, rip->version_send, 
-                          saddr);
+                          sconn, saddr);
       return;
     }
 
@@ -2317,7 +2373,7 @@
 			   inet_ntoa (to.sin_addr), ifp->name);
 
 	      rip_output_process (ifp, connected->address, &to, route_type,
-				 rip->version_send, saddr);
+				 rip->version_send, connected, saddr);
 	    }
 	}
     }
@@ -2371,10 +2427,11 @@
 	  LIST_LOOP(ifp->connected, connected, ifnode)
 	    {
 	      struct prefix_ipv4 *ifaddr;
-          
-
-	  /* If there is no version configuration in the interface,
-             use rip's version setting. */
+              int done = 0;
+	      /* 
+               * If there is no version configuration in the interface,
+               * use rip's version setting. 
+               */
 	      int vsend = ((ri->ri_send == RI_RIP_UNSPEC) ?
 			   rip->version_send : ri->ri_send);
 
@@ -2383,12 +2440,14 @@
 	      if (ifaddr->family != AF_INET)
 		continue;
 
-	      rip_interface_multicast_set(rip->sock, connected,
-					  if_is_pointopoint(ifp));
-	      if (vsend & RIPv1)
-		rip_update_interface (ifp, RIPv1, route_type, ifaddr);
-	      if (vsend & RIPv2)
-		rip_update_interface (ifp, RIPv2, route_type, ifaddr);
+              if ((vsend & RIPv1) && !done)
+	        rip_update_interface (ifp, RIPv1, route_type, connected);
+              if ((vsend & RIPv2) && if_is_multicast(ifp))
+	        rip_update_interface (ifp, RIPv2, route_type, connected);
+              done = 1;
+              if (!(vsend & RIPv2) || !if_is_multicast(ifp))
+                break;
+		
 	  }
 	}
     }
@@ -2413,7 +2472,8 @@
 	to.sin_port = htons (RIP_PORT_DEFAULT);
 
 	/* RIP version is rip's configuration. */
-	rip_output_process (ifp, NULL, &to, route_type, rip->version_send, p);
+	rip_output_process (ifp, NULL, &to, route_type, rip->version_send, 
+                            NULL, p);
       }
 }
 
@@ -2589,12 +2649,11 @@
 /* Sned RIP request to the destination. */
 int
 rip_request_send (struct sockaddr_in *to, struct interface *ifp,
-		  u_char version)
+		  u_char version, struct connected *connected)
 {
   struct rte *rte;
   struct rip_packet rip_packet;
   listnode node;
-  struct connected *connected;
 
   memset (&rip_packet, 0, sizeof (rip_packet));
 
@@ -2603,6 +2662,20 @@
   rte = rip_packet.rte;
   rte->metric = htonl (RIP_METRIC_INFINITY);
 
+  if (connected) 
+    {
+      /* 
+       * connected is only sent for ripv1 case, or when
+       * interface does not support multicast.  Caller loops
+       * over each connected address for this case.
+       */
+      if (rip_send_packet ((caddr_t) &rip_packet, sizeof (rip_packet), 
+                            to, ifp, connected) != sizeof (rip_packet))
+        return -1;
+      else
+        return sizeof (rip_packet);
+    }
+	
   /* send request on each connected network */
   LIST_LOOP(ifp->connected, connected, node)
     {
@@ -2613,10 +2686,8 @@
       if (p->family != AF_INET)
         continue;
 
-      rip_interface_multicast_set(rip->sock, connected,
-				  if_is_pointopoint(ifp));
       if (rip_send_packet ((caddr_t) &rip_packet, sizeof (rip_packet), 
-                            to, ifp) != sizeof (rip_packet))
+                            to, ifp, connected) != sizeof (rip_packet))
         return -1;
     }
   return sizeof (rip_packet);
===================================================================
RCS file: rip_interface.c,v
retrieving revision 1.13
retrieving revision 1.14
diff -uwb -r1.13 -r1.14
--- /tmp/T0HgWngj	Wed Jan 21 14:12:18 2004
+++ /tmp/T1IgWngj	Wed Jan 21 14:12:18 2004
@@ -146,16 +146,20 @@
       struct in_addr addr;
   struct prefix_ipv4 *p;
 
+  if (connected != NULL) 
+    {
   if (if_pointopoint)
     p = (struct prefix_ipv4 *) connected->destination;
   else
       p = (struct prefix_ipv4 *) connected->address;
-
 	  addr = p->prefix;
+    }
+  else 
+    {
+      addr.s_addr = INADDR_ANY;
+    }
 
-
-	  if (setsockopt_multicast_ipv4 (sock, IP_MULTICAST_IF,
-				 addr, 0, 0) < 0) 
+  if (setsockopt_multicast_ipv4 (sock, IP_MULTICAST_IF, addr, 0, 0) < 0) 
 	    {
 	      zlog_warn ("Can't setsockopt IP_MULTICAST_IF to fd %d", sock);
 	      return;
@@ -171,8 +175,9 @@
 	  else 
 	    from.sin_port = htons (RIP_PORT_DEFAULT);
 
-	  /* Address shoud be any address. */
+  /* Address should be any address. */
 	  from.sin_family = AF_INET;
+  if (connected)
   addr = ((struct prefix_ipv4 *) connected->address)->prefix;
 	  from.sin_addr = addr;
 #ifdef HAVE_SIN_LEN
@@ -182,7 +187,6 @@
     if (ripd_privs.change (ZPRIVS_RAISE))
       zlog_err ("rip_interface_multicast_set: could not raise privs");
       
-  bind (sock, NULL, 0); /* unbind any previous association */
   ret = bind (sock, (struct sockaddr *) & from, sizeof (struct sockaddr_in));
 	  if (ret < 0)
 	    {
@@ -209,7 +213,7 @@
       if (IS_RIP_DEBUG_EVENT)
 	zlog_info ("multicast request on %s", ifp->name);
 
-      rip_request_send (NULL, ifp, version);
+      rip_request_send (NULL, ifp, version, NULL);
       return;
     }
 
@@ -238,7 +242,7 @@
 	      if (IS_RIP_DEBUG_EVENT)
 		zlog_info ("SEND request to %s", inet_ntoa (to.sin_addr));
 	      
-	      rip_request_send (&to, ifp, version);
+	      rip_request_send (&to, ifp, version, connected);
 	    }
 	}
     }
@@ -284,7 +288,7 @@
   to.sin_port = htons (RIP_PORT_DEFAULT);
   to.sin_addr = addr;
 
-  rip_request_send (&to, NULL, rip->version_send);
+  rip_request_send (&to, NULL, rip->version_send, NULL);
 }
 
 /* Request routes at all interfaces. */
===================================================================
RCS file: ripd.h,v
retrieving revision 1.8
retrieving revision 1.9
diff -uwb -r1.8 -r1.9
--- /tmp/T0_RWpgj	Wed Jan 21 14:12:49 2004
+++ /tmp/T1aSWpgj	Wed Jan 21 14:12:49 2004
@@ -377,7 +377,8 @@
 int if_check_address (struct in_addr addr);
 int if_valid_neighbor (struct in_addr addr);
 
-int rip_request_send (struct sockaddr_in *, struct interface *, u_char);
+int rip_request_send (struct sockaddr_in *, struct interface *, u_char,
+                      struct connected *);
 int rip_neighbor_lookup (struct sockaddr_in *);
 void rip_redistribute_add (int, int, struct prefix_ipv4 *, unsigned int, 
 			   struct in_addr *);



More information about the Quagga-dev mailing list