Don't send RAs to the wrong place when DAD in progress.

CHANGELOG

@@ -58,6 +58,15 @@ version 2.64
 	    Check interface for outgoing unsolicited router 
 	    advertisements, rather than relying on interface address 
 	    configuration. Thanks to Gene Czarinski for the patch.
+
+	    Handle better attempts to transmit on interfaces which are
+	    still doing DAD, and specifically do not just transmit
+	    without setting source address and interface, since this
+	    can cause very puzzling effects when a router
+	    advertisement goes astray. Thanks again to Gene Czarinski.
+
+	    Get RA timers right when there is more than one
+	    dhcp-range on a subnet.
 	    
 
 version 2.63

src/forward.c

@@ -95,26 +95,19 @@ int send_from(int fd, int nowild, char *packet, size_t len,
 #endif
     }
   
- retry:
-  if (sendmsg(fd, &msg, 0) == -1)
+  while (sendmsg(fd, &msg, 0) == -1)
     {
-      /* certain Linux kernels seem to object to setting the source address in the IPv6 stack
-	 by returning EINVAL from sendmsg. In that case, try again without setting the
-	 source address, since it will nearly alway be correct anyway.  IPv6 stinks. */
-      if (errno == EINVAL && msg.msg_controllen)
-	{
-	  msg.msg_controllen = 0;
-	  goto retry;
-	}
-      
       if (retry_send())
-	goto retry;
+	continue;
+      
+      /* If interface is still in DAD, EINVAL results - ignore that. */
+      if (errno == EINVAL)
+	break;
       
       my_syslog(LOG_ERR, _("failed to send packet: %s"), strerror(errno));
-      
       return 0;
     }
-
+  
   return 1;
 }
           

src/radv.c

@@ -457,6 +457,7 @@ time_t periodic_ra(time_t now)
   char interface[IF_NAMESIZE+1];
   
   param.now = now;
+  param.iface = 0;
 
   while (1)
     {
@@ -482,7 +483,8 @@ time_t periodic_ra(time_t now)
 	 ever be able to send ra's and satistfy it. */
       if (iface_enumerate(AF_INET6, &param, iface_search))
 	context->ra_time = 0;
-      else if (indextoname(daemon->icmp6fd, param.iface, interface) &&
+      else if (param.iface != 0 &&
+	       indextoname(daemon->icmp6fd, param.iface, interface) &&
 	       iface_check(AF_LOCAL, NULL, interface))
 	{
 	  struct iname *tmp;
@@ -512,9 +514,11 @@ static int iface_search(struct in6_addr *local,  int prefix,
       if (context->ra_time != 0 && difftime(context->ra_time, param->now) <= 0.0)
 	{
 	  /* found an interface that's overdue for RA determine new 
-	     timeout value and zap other contexts on the same interface 
-	     so they don't timeout independently .*/
-	  param->iface = if_index;
+	     timeout value and arrange for RA to be sent unless interface is
+	     still doing DAD.*/
+
+	  if (!dad)
+	    param->iface = if_index;
 	  
 	  if (difftime(param->now, ra_short_period_start) < 60.0)
 	    /* range 5 - 20 */
@@ -523,6 +527,14 @@ static int iface_search(struct in6_addr *local,  int prefix,
 	    /* range 450 - 600 */
 	    context->ra_time = param->now + 450 + (rand16()/440);
 	  
+	  /* zero timers for other contexts on the same subnet, so they don't timeout 
+	     independently */
+	  for (context = context->next; context; context = context->next)
+	    if (prefix == context->prefix &&
+		is_same_net6(local, &context->start6, prefix) &&
+		is_same_net6(local, &context->end6, prefix))
+	      context->ra_time = 0;
+	  
 	  return 0; /* found, abort */
 	}