Add support for the IPV6_V6ONLY socket option defaulting to on.

src/options.c

@@ -154,6 +154,11 @@ int opt_set_ip_drop_membersip(lua_State *L, p_socket ps)
     return opt_setmembership(L, ps, IPPROTO_IP, IP_DROP_MEMBERSHIP);
 }
 
+int opt_set_ip6_v6only(lua_State *L, p_socket ps)
+{
+    return opt_setboolean(L, ps, IPPROTO_IPV6, IPV6_V6ONLY);
+}
+
 /*=========================================================================*\
 * Auxiliar functions
 \*=========================================================================*/

src/options.h

@@ -32,6 +32,7 @@ int opt_set_ip_multicast_ttl(lua_State *L, p_socket ps);
 int opt_set_ip_multicast_loop(lua_State *L, p_socket ps);
 int opt_set_ip_add_membership(lua_State *L, p_socket ps);
 int opt_set_ip_drop_membersip(lua_State *L, p_socket ps);
+int opt_set_ip6_v6only(lua_State *L, p_socket ps);
 /* invokes the appropriate option handler */
 int opt_meth_setoption(lua_State *L, p_opt opt, p_socket ps);
 

src/tcp.c

@@ -70,6 +70,7 @@ static t_opt optset[] = {
     {"keepalive",   opt_set_keepalive},
     {"reuseaddr",   opt_set_reuseaddr},
     {"tcp-nodelay", opt_set_tcp_nodelay},
+    {"ipv6-v6only", opt_set_ip6_v6only},
     {"linger",      opt_set_linger},
     {NULL,          NULL}
 };
@@ -334,6 +335,11 @@ static int tcp_create(lua_State *L, int domain) {
         auxiliar_setclass(L, "tcp{master}", -1);
         /* initialize remaining structure fields */
         socket_setnonblocking(&sock);
+        if (domain == PF_INET6) {
+            int yes = 1;
+            setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY,
+                (void *)&yes, sizeof(yes));
+        }
         tcp->sock = sock;
         io_init(&tcp->io, (p_send) socket_send, (p_recv) socket_recv, 
                 (p_error) socket_ioerror, &tcp->sock);

src/udp.c

@@ -77,6 +77,7 @@ static t_opt optset[] = {
     {"ip-multicast-loop",  opt_set_ip_multicast_loop},
     {"ip-add-membership",  opt_set_ip_add_membership},
     {"ip-drop-membership", opt_set_ip_drop_membersip},
+    {"ipv6-v6only",        opt_set_ip6_v6only},
     {NULL,                 NULL}
 };
 
@@ -352,6 +353,11 @@ static int udp_create(lua_State *L, int domain) {
         auxiliar_setclass(L, "udp{unconnected}", -1);
         /* initialize remaining structure fields */
         socket_setnonblocking(&sock);
+        if (domain == PF_INET6) {
+            int yes = 1;
+            setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY,
+                (void *)&yes, sizeof(yes));
+        }
         udp->sock = sock;
         timeout_init(&udp->tm, -1, -1);
         udp->domain = domain;