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#include <time.h>
#include <sys/types.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <stdint.h>
#include <event.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include "getstream.h"
#include "sap.h"
#include "socket.h"
/*
* Implement Mini-SAP Service
*
* RFC 2974 (Session Announcement Protocol)
* http://www.ietf.org/rfc/rfc2974.txt
* RFC 2327 (SDP: Session Description Protocol)
* http://www.ietf.org/rfc/rfc2327.txt
*
*/
/*
RFC 2327
v=0
o=mhandley 2890844526 2890842807 IN IP4 126.16.64.4
o=<username> <session id> <version> <network type> <address type> <address>
s=SDP Seminar
i=A Seminar on the session description protocol
u=http://www.cs.ucl.ac.uk/staff/M.Handley/sdp.03.ps
e=mjh@isi.edu (Mark Handley)
c=IN IP4 224.2.17.12/127
c=<network type> <address type> <connection address>
t=2873397496 2873404696
a=recvonly
m=audio 49170 RTP/AVP 0
m=video 51372 RTP/AVP 31
m=application 32416 udp wb
m=<media> <port> <transport> <fmt list>
a=orient:portrait
*/
static void sap_init_timer_single(struct sap_s *sap);
static char sappkt[SAP_MAX_SIZE];
static int sid=1; /* MSG Identifier - Unique for each session */
#define SAP_VERSION 1
#define SAP_VERSION_SHIFT 5
static void sap_send(int fd, short event, void *arg) {
struct sap_s *sap=arg;
char *sp;
/* Clear Packet */
memset(&sappkt, 0, SAP_MAX_SIZE);
sappkt[0]=SAP_VERSION<<SAP_VERSION_SHIFT; /* Version + Bitfield */
sappkt[1]=0x0; /* Auth len */
sappkt[2]=sap->sid>>8&0xff; /* Unique session ID */
sappkt[3]=sap->sid&0xff;
/*
* FIXME - This would need to be the originating
* not the destination address
*/
sappkt[4]=sap->addr&0xff;
sappkt[5]=sap->addr>>8&0xff;
sappkt[6]=sap->addr>>16&0xff;
sappkt[7]=sap->addr>>24&0xff;
sp=sappkt+8;
sp+=sprintf(sp, "v=0\r\n");
sp+=sprintf(sp, "o=%s\r\n", sap->odata);
if (sap->output->stream->name)
sp+=sprintf(sp, "s=%s\r\n", sap->output->stream->name);
sp+=sprintf(sp, "t=0 0\r\n");
sp+=sprintf(sp, "a=tool:getstream\r\n");
sp+=sprintf(sp, "a=type:broadcast\r\n");
sp+=sprintf(sp, "m=%s\r\n", sap->mdata);
sp+=sprintf(sp, "c=%s\r\n", sap->cdata);
if (sap->playgroup) {
sp+=sprintf(sp, "a=x-plgroup:%s\r\n", sap->playgroup);
}
send(sap->fd, sappkt, sp-sappkt, MSG_DONTWAIT);
sap_init_timer_single(sap);
}
static void sap_init_timer_single(struct sap_s *sap) {
static struct timeval tv;
/*
* Create timer to send out SAPs regularly
*/
tv.tv_usec=0;
tv.tv_sec=1;
evtimer_set(&sap->event, &sap_send, sap);
evtimer_add(&sap->event, &tv);
}
static void sap_init_socket_single(struct sap_s *sap) {
char *maddr;
int port;
sap->fd=socket_open(NULL, 0);
if (sap->fd == -1) {
fprintf(stderr, "Unable to open SAP socket\n");
exit(-1);
}
/* Last resort Multicast config */
maddr=SAP_V4_GLOBAL_ADDRESS;
port=SAP_PORT;
/* get SAP remote address from scope or group */
if (sap->scope) {
/* Most simple way - We have a scope */
if (strcasecmp(sap->scope, "global") == 0) {
maddr=SAP_V4_GLOBAL_ADDRESS;
} else if(strcasecmp(sap->scope, "org") == 0) {
maddr=SAP_V4_ORG_ADDRESS;
} else if(strcasecmp(sap->scope, "local") == 0) {
maddr=SAP_V4_LOCAL_ADDRESS;
} else {
maddr=SAP_V4_LINK_ADDRESS;
}
port=SAP_PORT;
} else if(sap->group) {
maddr=sap->group;
port=sap->port;
}
socket_join_multicast(sap->fd, maddr);
socket_connect(sap->fd, maddr, port);
socket_set_ttl(sap->fd, sap->ttl);
}
/* Create SDP Connection Data as per RFC2327 */
static char *sap_init_cdata(struct sap_s *sap) {
char cdata[128];
/* mcast c=IN IP4 ipaddr/ttl */
/* ucast c=IN IP4 ipaddr */
/* Ignore the ucast case for UDP and RTP as it does not make
* sense to announce ucast UDP/RTP
*/
switch(sap->output->type) {
case(OTYPE_UDP):
case(OTYPE_RTP):
sprintf(cdata, "IN IP4 %s/%d",
sap->output->remoteaddr,
sap->output->ttl);
break;
case(OTYPE_RTCP):
if (sap->output->localaddr) {
sprintf(cdata, "IN IP4 %s/%d",
sap->output->localaddr,
sap->output->ttl);
} else {
char hname[80];
gethostname(hname, sizeof(hname));
sprintf(cdata, "IN IP4 %s/%d",
hname,
sap->output->ttl);
}
break;
default:
fprintf(stderr, "Unknown stream output type in %s", __FUNCTION__);
exit(-1);
}
return strdup(cdata);
}
/* Create SDP Media Announcement as per RFC2327 */
static char *sap_init_mdata(struct sap_s *sap) {
char mdata[128];
/* m=audio/video ipport udp 33 */
/* m=audio/video ipport rtp/avp 31 */
switch(sap->output->type) {
case(OTYPE_UDP):
sprintf(mdata, "video %d udp 33",
sap->output->remoteport);
break;
case(OTYPE_RTP):
sprintf(mdata, "video %d RTP/AVP 33",
sap->output->remoteport);
break;
case(OTYPE_RTCP):
sprintf(mdata, "video %d RTP/AVP 33",
sap->output->rtpport);
break;
}
return strdup(mdata);
}
/* Create SDP Origin as per RFC2327 */
static char *sap_init_odata(struct sap_s *sap) {
char odata[128];
switch(sap->output->type) {
case(OTYPE_UDP):
case(OTYPE_RTP):
sprintf(odata, "- %d %lu IN IP4 %s",
sap->sid,
time(NULL),
sap->output->remoteaddr);
break;
case(OTYPE_RTCP):
if (sap->output->localaddr) {
sprintf(odata, "IN IP4 %s",
sap->output->localaddr);
} else {
char hname[80];
gethostname(hname, sizeof(hname));
sprintf(odata, "- %d %lu IN IP4 %s",
sap->sid,
time(NULL),
hname);
}
break;
}
return strdup(odata);
}
int sap_init(struct sap_s *sap) {
/* Copy a Session ID into the SAP structure. This needs to be unique
* for a SAP sender and needs to be changed in case the SAP announcement
* changes
*/
sap->sid=sid++;
/* Open Socket */
sap_init_socket_single(sap);
/* Create Stream Connection Data for SDP */
sap->cdata=sap_init_cdata(sap);
/* Create Media Announcement Data for SDP */
sap->mdata=sap_init_mdata(sap);
/* Create Origin Data for SDP */
sap->odata=sap_init_odata(sap);
/* Start timer */
sap_init_timer_single(sap);
return 1;
}
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