[svn-commits] file: branch file/issue11797 r187639 - /team/file/issue11797/res/

[SVN commits to the Digium repositories]

Author: file
Date: Fri Apr 10 10:13:19 2009
New Revision: 187639

URL: http://svn.digium.com/svn-view/asterisk?view=rev&rev=187639
Log:
Add the rest of the needed bits. This should now send the control packets for Linksys type paging and should
also send the actual RTP packets.

Modified:
    team/file/issue11797/res/res_rtp_multicast.c

Modified: team/file/issue11797/res/res_rtp_multicast.c
URL: http://svn.digium.com/svn-view/asterisk/team/file/issue11797/res/res_rtp_multicast.c?view=diff&rev=187639&r1=187638&r2=187639
==============================================================================
--- team/file/issue11797/res/res_rtp_multicast.c (original)
+++ team/file/issue11797/res/res_rtp_multicast.c Fri Apr 10 10:13:19 2009
@@ -81,8 +81,10 @@
 	enum multicast_type type;
 	/*! Socket used for sending the audio on */
 	int socket;
-	/*! Control address used for Linksys paging */
-	struct sockaddr_in control_address;
+	/*! Synchronization source value, used when creating/sending the RTP packet */
+	unsigned int ssrc;
+	/*! Sequence number, used when creating/sending the RTP packet */
+	unsigned int seqno;
 };
 
 /* Forward Declarations */
@@ -126,7 +128,35 @@
 		return -1;
 	}
 
+	multicast->ssrc = ast_random();
+
 	ast_rtp_instance_set_data(instance, multicast);
+
+	return 0;
+}
+
+/*! \brief Helper function which populates a control packet with useful information and sends it */
+static int multicast_send_control_packet(struct ast_rtp_instance *instance, struct multicast_rtp *multicast, int command)
+{
+	struct multicast_control_packet control_packet = { .unique_id = htonl((u_long)time(NULL)),
+							   .command = htonl(command),
+	};
+	struct sockaddr_in control_address, remote_address;
+
+	ast_rtp_instance_get_local_address(instance, &control_address);
+	ast_rtp_instance_get_remote_address(instance, &remote_address);
+
+	/* Ensure the user of us have given us both the control address and destination address */
+	if (!control_address.sin_addr.s_addr || !remote_address.sin_addr.s_addr) {
+		return -1;
+	}
+
+	memcpy(&control_packet.ip, &remote_address.sin_addr, sizeof(control_packet.ip));
+	control_packet.port = htonl(ntohs(remote_address.sin_port));
+
+	/* Based on a recommendation by Brian West who did the FreeSWITCH implementation we send control packets twice */
+	sendto(multicast->socket, &control_packet, sizeof(control_packet), 0, (struct sockaddr *)&control_address, sizeof(control_address));
+	sendto(multicast->socket, &control_packet, sizeof(control_packet), 0, (struct sockaddr *)&control_address, sizeof(control_address));
 
 	return 0;
 }
@@ -136,11 +166,11 @@
 {
 	struct multicast_rtp *multicast = ast_rtp_instance_get_data(instance);
 
-	if (multicast->type == MULTICAST_TYPE_LINKSYS) {
-		struct multicast_control_packet control_packet = { 0, };
-	}
-
-	return 0;
+	if (multicast->type != MULTICAST_TYPE_LINKSYS) {
+		return 0;
+	}
+
+	return multicast_send_control_packet(instance, multicast, LINKSYS_MCAST_STARTCMD);
 }
 
 /*! \brief Function called to destroy a multicast instance */
@@ -149,7 +179,7 @@
 	struct multicast_rtp *multicast = ast_rtp_instance_get_data(instance);
 
 	if (multicast->type == MULTICAST_TYPE_LINKSYS) {
-		struct multicast_control_packet control_packet = { 0, };
+		multicast_send_control_packet(instance, multicast, LINKSYS_MCAST_STOPCMD);
 	}
 
 	close(multicast->socket);
@@ -163,18 +193,42 @@
 static int multicast_rtp_write(struct ast_rtp_instance *instance, struct ast_frame *frame)
 {
 	struct multicast_rtp *multicast = ast_rtp_instance_get_data(instance);
+	struct ast_frame *f = frame;
 	struct sockaddr_in remote_address;
-	int hdrlen = 12, res;
-	unsigned char *rtpheader = (unsigned char *)(frame->data.ptr - hdrlen);
+	int hdrlen = 12, res, codec;
+	unsigned char *rtpheader;
 
 	/* We only accept audio, nothing else */
 	if (frame->frametype != AST_FRAME_VOICE) {
 		return 0;
 	}
 
+	/* Grab the actual payload number for when we create the RTP packet */
+	if ((codec = ast_rtp_codecs_payload_code(ast_rtp_instance_get_codecs(instance), 1, frame->subclass)) < 0) {
+		return -1;
+	}
+
+	/* If we do not have space to construct an RTP header duplicate the frame so we get some */
+	if (frame->offset < hdrlen) {
+		f = ast_frdup(frame);
+	}
+
+	/* Construct an RTP header for our packet */
+	rtpheader = (unsigned char *)(f->data.ptr - hdrlen);
+	put_unaligned_uint32(rtpheader, htonl((2 << 30) | (codec << 16) | (multicast->seqno++) | (0 << 23)));
+	put_unaligned_uint32(rtpheader + 4, htonl(f->ts * 8));
+	put_unaligned_uint32(rtpheader + 8, htonl(multicast->ssrc));
+
+	/* Finally send it out to the eager phones listening for us */
 	ast_rtp_instance_get_remote_address(instance, &remote_address);
-
-	return -1;
+	res = sendto(multicast->socket, (void *)rtpheader, f->datalen + hdrlen, 0, (struct sockaddr *)&remote_address, sizeof(remote_address));
+
+	/* If we were forced to duplicate the frame free the new one */
+	if (frame != f) {
+		ast_frfree(f);
+	}
+
+	return res;
 }
 
 /*! \brief Function called to read from a multicast instance */