[FEATURE] Support for Source-Specific Multicast (#802)

* Support for Source-Specific Multicast

* fixing whitespace issues

* updating changelog

docs/CHANGES.TXT

@@ -1,3 +1,7 @@
+0.87
+-----------------
+- New: Support for source-specific multicast.
+
 0.86
 -----------------
 - New: Added a histogram in one-minute increments of the number of lines in a subtitle.

src/GUI/popups.c

@@ -48,7 +48,7 @@ void draw_network_popup(struct nk_context *ctx, struct network_popup *network_se
 			nk_label(ctx, "UDP:", NK_TEXT_CENTERED);
 			nk_layout_row_static(ctx, 20, 200, 2);
 			nk_label(ctx, "Hostname/IPv4 Address:", NK_TEXT_LEFT);
-			nk_edit_string(ctx, NK_EDIT_SIMPLE, network_settings->udp_ipv4, &network_settings->udp_ipv4_len, 25, nk_filter_default);
+			nk_edit_string(ctx, NK_EDIT_SIMPLE, network_settings->udp_ipv4, &network_settings->udp_ipv4_len, 50, nk_filter_default);
 
 			nk_layout_row(ctx, NK_DYNAMIC, 21, 3, udp_tcp_ratio);
 			nk_spacing(ctx, 1);

src/lib_ccx/ccx_common_option.c

@@ -90,6 +90,7 @@ void init_options (struct ccx_s_options *options)
 	options->debug_mask=CCX_DMT_GENERIC_NOTICES; // dbg_print will use this mask to print or ignore different types
 	options->debug_mask_on_debug=CCX_DMT_VERBOSE; // If we're using temp_debug to enable/disable debug "live", this is the mask when temp_debug=1
 	/* Networking */
+	options->udpsrc = NULL;
 	options->udpaddr = NULL;
 	options->udpport=0; // Non-zero => Listen for UDP packets on this port, no files.
 	options->send_to_srv = 0;

src/lib_ccx/ccx_common_option.h

@@ -157,6 +157,7 @@ struct ccx_s_options // Options from user parameters
 	LLONG debug_mask;                                   // dbg_print will use this mask to print or ignore different types
 	LLONG debug_mask_on_debug;                          // If we're using temp_debug to enable/disable debug "live", this is the mask when temp_debug=1
 	/* Networking */
+	char *udpsrc;
 	char *udpaddr;
 	unsigned udpport;                                   // Non-zero => Listen for UDP packets on this port, no files.
 	char *tcpport;

src/lib_ccx/ccx_demuxer.c

@@ -78,7 +78,7 @@ static int ccx_demuxer_open(struct ccx_demuxer *ctx, const char *file)
 			return -1;
 		}
 
-		ctx->infd = start_upd_srv(ccx_options.udpaddr, ccx_options.udpport);
+		ctx->infd = start_upd_srv(ccx_options.udpsrc, ccx_options.udpaddr, ccx_options.udpport);
 		if(ctx->infd < 0)
 		{
 			print_error(ccx_options.gui_mode_reports,"socket() failed.");

src/lib_ccx/networking.c

@@ -927,10 +927,28 @@ ssize_t read_byte(int fd, char *ch)
 	return readn(fd, ch, 1);
 }
 
-int start_upd_srv(const char *addr_str, unsigned port)
+int start_upd_srv(const char *src_str, const char *addr_str, unsigned port)
 {
 	init_sockets();
 
+	in_addr_t src;
+	if (src_str != NULL)
+	{
+		struct hostent *host = gethostbyname(src_str);
+		if (NULL == host)
+		{
+			fatal(EXIT_MALFORMED_PARAMETER, "Cannot look up udp network address: %s\n",
+					src_str);
+		}
+		else if (host->h_addrtype != AF_INET)
+		{
+			fatal(EXIT_MALFORMED_PARAMETER, "No support for non-IPv4 network addresses: %s\n",
+					src_str);
+		}
+
+		src = ntohl(((struct in_addr *)host->h_addr_list[0])->s_addr);
+	}
+
 	in_addr_t addr;
 	if (addr_str != NULL)
 	{
@@ -1000,10 +1018,23 @@ int start_upd_srv(const char *addr_str, unsigned port)
 	}
 
 	if (IN_MULTICAST(addr)) {
-		struct ip_mreq group;
-		group.imr_multiaddr.s_addr = htonl(addr);
-		group.imr_interface.s_addr = htonl(INADDR_ANY);
-		if (setsockopt(sockfd, IPPROTO_IP, IP_ADD_MEMBERSHIP, (char *)&group, sizeof(group)) < 0)
+		int setsockopt_return = 0;
+		if (src_str != NULL) {
+			struct ip_mreq_source multicast_req;
+			multicast_req.imr_sourceaddr.s_addr = htonl(src);
+			multicast_req.imr_multiaddr.s_addr = htonl(addr);
+			multicast_req.imr_interface.s_addr = htonl(INADDR_ANY);
+			setsockopt_return = setsockopt(sockfd, IPPROTO_IP, IP_ADD_SOURCE_MEMBERSHIP, (char *)&multicast_req, sizeof(multicast_req));
+		}
+		else
+		{
+			struct ip_mreq multicast_req;
+			multicast_req.imr_multiaddr.s_addr = htonl(addr);
+			multicast_req.imr_interface.s_addr = htonl(INADDR_ANY);
+			setsockopt_return = setsockopt(sockfd, IPPROTO_IP, IP_ADD_MEMBERSHIP, (char *)&multicast_req, sizeof(multicast_req));
+		}
+
+		if (setsockopt_return < 0)
 		{
 #if _WIN32
 			wprintf(L"setsockopt() error: %ld\n", WSAGetLastError());
@@ -1019,6 +1050,21 @@ int start_upd_srv(const char *addr_str, unsigned port)
 	{
 		mprint("\rReading from UDP socket %u\n", port);
 	}
+	else if (src_str != NULL)
+	{
+		struct in_addr source;
+		struct in_addr group;
+		char src_ip[15];
+		char addr_ip[15];
+		source.s_addr = htonl(src);
+		memset(src_ip, 0, sizeof(char) * 15);
+		memcpy(src_ip, inet_ntoa(source), sizeof(src_ip));
+		group.s_addr = htonl(addr);
+		memset(addr_ip, 0, sizeof(char) * 15);
+		memcpy(addr_ip, inet_ntoa(group), sizeof(addr_ip));
+
+		mprint("\rReading from UDP socket %s@%s:%u\n", src_ip, addr_ip, port);
+	}
 	else
 	{
 		struct in_addr in;

src/lib_ccx/networking.h

@@ -23,6 +23,6 @@ int net_tcp_read(int socket, void *buffer, size_t length);
 
 int start_tcp_srv(const char *port, const char *pwd);
 
-int start_upd_srv(const char *addr, unsigned port);
+int start_upd_srv(const char *src, const char *addr, unsigned port);
 
 #endif /* end of include guard: NETWORKING_H */

src/lib_ccx/params.c

@@ -335,6 +335,10 @@ void print_usage (void)
 	mprint ("                              port) instead of reading a file. Host can be a\n");
 	mprint ("                              hostname or IPv4 address. If host is not specified\n");
 	mprint ("                              then listens on the local host.\n\n");
+	mprint ("            -udp [src@host:]port: Read the input via UDP (listening in the specified\n");
+	mprint ("                              port) instead of reading a file. Host and src can be a\n");
+	mprint ("                              hostname or IPv4 address. If host is not specified\n");
+	mprint ("                              then listens on the local host.\n\n");
 	mprint ("            -sendto host[:port]: Sends data in BIN format to the server\n");
 	mprint ("                                 according to the CCExtractor's protocol over\n");
 	mprint ("                                 TCP. For IPv6 use [address]:port\n");
@@ -2220,8 +2224,21 @@ int parse_parameters (struct ccx_s_options *opt, int argc, char *argv[])
 		/* Network stuff */
 		if (strcmp (argv[i],"-udp")==0 && i<argc-1)
 		{
+			char *at = strchr(argv[i + 1], '@');
 			char *colon = strchr(argv[i + 1], ':');
-			if (colon)
+			if (at && !colon)
+			{
+				fatal(EXIT_MALFORMED_PARAMETER, "If -udp contains an '@', it must also contain a ':'");
+			}
+			else if (at && colon)
+			{
+				*at = '\0';
+				*colon = '\0';
+				opt->udpsrc = argv[i + 1];
+				opt->udpaddr = at + 1;
+				opt->udpport = atoi_hex(colon + 1);
+			}
+			else if (colon)
 			{
 				*colon = '\0';
 				opt->udpaddr = argv[i + 1];

src/lib_ccx/params_dump.c

@@ -18,7 +18,9 @@ void params_dump(struct lib_ccx_ctx *ctx)
 			mprint ("stdin");
 			break;
 		case CCX_DS_NETWORK:
-			if (ccx_options.udpaddr == NULL)
+			if (ccx_options.udpsrc != NULL)
+				mprint ("Network, %s@%s:%d", ccx_options.udpsrc, ccx_options.udpaddr, ccx_options.udpport);
+			else if (ccx_options.udpaddr == NULL)
 				mprint ("Network, UDP/%u",ccx_options.udpport);
 			else
 			{