Allow more than one --bridge-interface option to refer to an interface.

CHANGELOG

@@ -23,6 +23,14 @@ version 2.79
 	time validation when --dnssec-no-timecheck is in use.
 	Note that this is an incompatible change from earlier releases.
 
+	Allow more than one --bridge-interface option to refer to an
+	interface, so that we can use
+	--bridge-interface=int1,alias1
+	--bridge-interface=int1,alias2
+	as an alternative to
+	--bridge-interface=int1,alias1,alias2
+	Thanks to Neil Jerram for work on this.
+	
 
 version 2.78
         Fix logic of appending ".<layer>" to PXE basename. Thanks to Chris

man/dnsmasq.8

@@ -1695,13 +1695,17 @@ option also forces the leasechange script to be called on changes
 to the client-id and lease length and expiry time.
 .TP
 .B --bridge-interface=<interface>,<alias>[,<alias>]
-Treat DHCP (v4 and v6) request and IPv6 Router Solicit packets
+Treat DHCP (v4 and v6) requests and IPv6 Router Solicit packets
 arriving at any of the <alias> interfaces as if they had arrived at
 <interface>.  This option allows dnsmasq to provide DHCP and RA
 service over unaddressed and unbridged Ethernet interfaces, e.g. on an
 OpenStack compute host where each such interface is a TAP interface to
 a VM, or as in "old style bridging" on BSD platforms.  A trailing '*'
 wildcard can be used in each <alias>.
+
+It is permissible to add more than one alias using more than one --bridge-interface option since 
+--bridge-interface=int1,alias1,alias2 is exactly equivalent to
+--bridge-interface=int1,alias1 --bridge-interface=int1,alias2
 .TP
 .B \-s, --domain=<domain>[,<address range>[,local]]
 Specifies DNS domains for the DHCP server. Domains may be be given 

src/option.c

@@ -2733,15 +2733,24 @@ static int one_opt(int option, char *arg, char *errstr, char *gen_err, int comma
 	      
     case LOPT_BRIDGE:   /* --bridge-interface */
       {
-	struct dhcp_bridge *new = opt_malloc(sizeof(struct dhcp_bridge));
+	struct dhcp_bridge *new;
+
 	if (!(comma = split(arg)) || strlen(arg) > IF_NAMESIZE - 1 )
 	  ret_err(_("bad bridge-interface"));
-	
-	strcpy(new->iface, arg);
-	new->alias = NULL;
-	new->next = daemon->bridges;
-	daemon->bridges = new;
 
+	for (new = daemon->bridges; new; new = new->next)
+	  if (strcmp(new->iface, arg) == 0)
+	    break;
+
+	if (!new)
+	  {
+	     new = opt_malloc(sizeof(struct dhcp_bridge));
+	     strcpy(new->iface, arg);
+	     new->alias = NULL;
+	     new->next = daemon->bridges;
+	     daemon->bridges = new;
+	  }
+	
 	do {
 	  arg = comma;
 	  comma = split(arg);