X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=udp_send.c;h=140458e7ed9b1d4e3a03d05c2e26a6b36d66db54;hp=b0f55bc35c7ccb661b6db32997a88fc9284ed98e;hb=1e6a73e98fecaba8226d5a4aa3cdc84e410f8029;hpb=01556501c32d5ec155cc7e2cd78307ec1f177a07

diff --git a/udp_send.c b/udp_send.c
index b0f55bc3..140458e7 100644
--- a/udp_send.c
+++ b/udp_send.c
@@ -68,19 +68,107 @@ static void udp_delete_target(struct udp_target *ut, const char *msg)
 	free(ut);
 }
 
+/**
+ * Perform AF-independent multicast sender setup.
+ *
+ * \param fd	The connected socket descriptor.
+ * \param ttl	UDPv4 multicast TTL or UDPv6 multicast number of hops.
+ *		Use -1 to mean default, 0..255 otherwise.
+ * \param iface	The outgoing multicast interface, or NULL for the default.
+ *
+ * \return Zero if okay, negative on error.
+ */
+static int mcast_sender_setup(struct udp_target *ut, int ttl, char *iface)
+{
+	struct sockaddr_storage ss;
+	socklen_t sslen = sizeof(ss);
+
+	const int on = 1;
+	int id = iface == NULL ? 0 : if_nametoindex(iface);
+
+	if (getpeername(ut->fd, (struct sockaddr *)&ss, &sslen) < 0)
+		goto err;
+
+	if (iface != NULL && id == 0)
+		PARA_WARNING_LOG("could not resolve interface %s, using default", iface);
+
+	/* RFC 3493, 5.2: -1 means 'use kernel default' */
+	if (ttl < 0 || ttl > 255)
+		ttl = -1;
+
+	switch (ss.ss_family) {
+	case AF_INET:
+		if (!IN_MULTICAST(htonl(((struct sockaddr_in *)&ss)->sin_addr.s_addr)))
+			return 0;
+		if (id != 0) {
+#ifdef HAVE_IP_MREQN
+			struct ip_mreqn mn;
+
+			memset(&mn, 0, sizeof(mn));
+			mn.imr_ifindex = id;
+			if (setsockopt(ut->fd, IPPROTO_IP, IP_MULTICAST_IF, &mn, sizeof(mn)) < 0)
+				goto err;
+#else
+			PARA_ERROR_LOG("No support for setting outgoing IPv4 mcast interface.");
+#endif
+		}
+		/*
+		 * Enable receiving multicast messages generated on the local host
+		 * At least on Linux, this is enabled by default.
+		 */
+		if (setsockopt(ut->fd, IPPROTO_IP, IP_MULTICAST_LOOP, &on, sizeof(on)) < 0)
+			break;
+
+		/* Default: use local subnet (do not flood out into the WAN) */
+		if (ttl == -1)
+			ttl = 1;
+		if (setsockopt(ut->fd, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)) < 0)
+			break;
+		return 0;
+	case AF_INET6:
+		if (!IN6_IS_ADDR_MULTICAST(&((struct sockaddr_in6 *)&ss)->sin6_addr))
+			return 0;
+		if (id != 0 &&
+		    setsockopt(ut->fd, IPPROTO_IPV6, IPV6_MULTICAST_IF, &id, sizeof(id)) < 0)
+			break;
+		if (setsockopt(ut->fd, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &on, sizeof(on)) < 0)
+			break;
+		if (setsockopt(ut->fd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &ttl, sizeof(ttl)) < 0)
+			break;
+		return 0;
+	default:
+		PARA_ERROR_LOG("address family %d not supported", ss.ss_family);
+		return -E_ADDRESS_LOOKUP;
+	}
+err:
+	return -ERRNO_TO_PARA_ERROR(errno);
+}
+
+/** The maximal size of the per-target chunk queue. */
 #define UDP_CQ_BYTES 40000
 
 static int udp_init_session(struct udp_target *ut)
 {
 	int ret;
+	char *iface = NULL;
 
 	if (ut->fd >= 0) /* nothing to do */
 		return 0;
-	ret = create_udp_send_socket(TARGET_ADDR(ut), ut->port,
-		conf.udp_ttl_arg);
+
+	ret = makesock(AF_UNSPEC, IPPROTO_UDP, 0, TARGET_ADDR(ut), ut->port);
 	if (ret < 0)
 		return ret;
 	ut->fd = ret;
+
+	if (conf.udp_mcast_iface_given)
+		iface = conf.udp_mcast_iface_arg;
+
+	ret = mcast_sender_setup(ut, conf.udp_ttl_arg, iface);
+	if (ret < 0) {
+		close(ut->fd);
+		return ret;
+	}
+
 	ret = mark_fd_nonblocking(ut->fd);
 	if (ret < 0) {
 		close(ut->fd);