[FIX] for issue #668 (Windows and Multicast) (#1059)

* Fixed udp multicast stream issue on windows

* Optimized OS detection for source multicast.

* Moved the udp read code to networking.c file

src/lib_ccx/file_functions.c

@@ -190,7 +190,7 @@ void position_sanity_check(struct ccx_demuxer *ctx)
 	{
 		LLONG realpos = LSEEK (ctx->infd,0,SEEK_CUR);
 		if (realpos == -1) // Happens for example when infd==stdin.
-			return; 
+			return;
 		if (realpos != ctx->past - ctx->filebuffer_pos + ctx->bytesinbuffer)
 		{
 			fatal (CCX_COMMON_EXIT_BUG_BUG, "Position desync, THIS IS A BUG. Real pos =%lld, past=%lld.\n", realpos, ctx->past);
@@ -391,7 +391,7 @@ size_t buffered_read_opt (struct ccx_demuxer *ctx, unsigned char *buffer, size_t
 				else if (ccx_options.input_source == CCX_DS_TCP)
 					i = net_tcp_read(ctx->infd, (char *) ctx->filebuffer + keep, FILEBUFFERSIZE - keep);
 				else
-					i = recvfrom(ctx->infd,(char *) ctx->filebuffer + keep, FILEBUFFERSIZE - keep, 0, NULL, NULL);
+					i = net_udp_read(ctx->infd, (char*) ctx->filebuffer + keep, FILEBUFFERSIZE - keep, ccx_options.udpsrc, ccx_options.udpaddr);
 				if (terminate_asap) /* Looks like receiving a signal here will trigger a -1, so check that first */
 					break;
 				if (i == -1)

src/lib_ccx/networking.c

@@ -329,6 +329,44 @@ int net_tcp_read(int socket, void *buffer, size_t length)
 	return l;
 }
 
+int net_udp_read(int socket, void *buffer, size_t length, const char *src_str, const char *addr_str)
+{
+	assert(buffer != NULL);
+	assert(length > 0);
+
+	int i;
+	char ip[50] = "";
+	struct sockaddr_in source_addr;
+	socklen_t len = sizeof(source_addr);
+	/* Get address of host to check for udp network mutlicasting */
+	in_addr_t addr;
+	if (addr_str != NULL)
+	{
+		struct hostent *host = gethostbyname(addr_str);
+		addr = ntohl(((struct in_addr *)host->h_addr_list[0])->s_addr);
+	}
+	else
+	{
+		addr = INADDR_ANY;
+	}
+	#ifdef _WIN32
+	if (IN_MULTICAST(addr) && src_str != NULL)						  					/* We check if the case is of source multicast and we are in windowsOS */
+	{
+		do {
+			i = recvfrom(socket, (char *) buffer, length, 0, (struct sockaddr*)&source_addr, &len); /* peek at the data*/
+			inet_ntop(AF_INET, &(source_addr.sin_addr), ip, 50);
+		} while (strcmp(ip, src_str)!=0);												/* Loop till we find intended source */
+	}
+	else
+		i = recvfrom(socket, (char *) buffer, length, 0, NULL, NULL); 								/*read normally if not source mutlicast case*/
+	#else
+	i = recvfrom(socket, (char *) buffer, length, 0, NULL, NULL); 									/*read normally if not windows*/
+	#endif
+
+	return i;
+}
+
+
 /*
  * command | length        | data         | \r\n
  * 1 byte  | INT_LEN bytes | length bytes | 2 bytes
@@ -507,7 +545,7 @@ int start_tcp_srv(const char *port, const char *pwd)
 		if ((sockfd = accept(listen_sd, cliaddr, &clilen)) < 0)
 		{
 			if (EINTR == errno) /* TODO not necessary */
-			{   
+			{
                 		free(cliaddr);
 				continue;
 			}
@@ -999,7 +1037,7 @@ int start_upd_srv(const char *src_str, const char *addr_str, unsigned port)
 	servaddr.sin_port = htons(port);
 #if _WIN32
 	// Doesn't seem correct, if there's more than one multicast stream with the same
-	// port number we get corruption - IP address needs to be specified, but 
+	// port number we get corruption - IP address needs to be specified, but
 	// in Windows we get an error 10049 (cannot bind).
 	// http ://stackoverflow.com/questions/6140734/cannot-bind-to-multicast-address-windows
 	servaddr.sin_addr.s_addr = htonl(IN_MULTICAST(addr) ? INADDR_ANY : addr);

src/lib_ccx/networking.h

@@ -20,6 +20,7 @@ void net_send_epg(
 		);
 
 int net_tcp_read(int socket, void *buffer, size_t length);
+int net_udp_read(int socket, void *buffer, size_t length, const char *src_str, const char *addr_str);
 
 int start_tcp_srv(const char *port, const char *pwd);