基于exosip 编写呼叫流程实例
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本文链接：https://blog.csdn.net/zzqgtt/article/details/87179815
1、已经编译生成号exosip相关库，
2、复制如下代码生成UAC，该实例使用的是windows控制台程序，对于sdp的解析部分需修改一下
代码如下:
#include
#include
#include
#include
int main(int argc, char *argv[])
{
struct eXosip_t *context_eXosip;
eXosip_event_t *je;
osip_message_t *reg = NULL;
osip_message_t *invite = NULL;
osip_message_t *ack = NULL;
osip_message_t *info = NULL;
osip_message_t *message = NULL;
int call_id, dialog_id;
int i, flag;
int flag1 = 1;
char *identity = "sip:[email protected]"; //UAC1，端口是15060
char *registar = "sip:[email protected]:15061"; //UAS,端口是15061
char *source_call = "sip:[email protected]";
char *dest_call = "sip:[email protected]:15061";
//identify和register这一组地址是和source和destination地址相同的
//在这个例子中，uac和uas通信，则source就是自己的地址，而目的地址就是uac1的地址
char command;
char tmp[4096];
printf("r 向服务器注册\n\n");
printf("c 取消注册\n\n");
printf("i 发起呼叫请求\n\n");
printf("h 挂断\n\n");
printf("q 推出程序\n\n");
printf("s 执行方法INFO\n\n");
printf("m 执行方法MESSAGE\n\n");
//初始化
struct eXosip_t *excontext;
excontext = eXosip_malloc();
i = eXosip_init(excontext);
if (i != 0)
{
printf("Couldn't initialize eXosip!\n");
osip_free(excontext);
return -1;
}
else
{
printf("eXosip_init successfully!\n");
}
//绑定uac自己的端口15060，并进行端口监听
i = eXosip_listen_addr(excontext, IPPROTO_UDP, NULL, 15060, AF_INET, 0);
if (i != 0)
{
eXosip_quit(excontext);
fprintf(stderr, "Couldn't initialize transport layer!\n");
osip_free(excontext);
return -1;
}
flag = 1;
while (flag)
{
//输入命令
printf("Please input the command:\n");
scanf_s("%c", &command);
getchar();
switch (command)
{
case 'r':
printf("This modal is not completed!\n");
break;
case 'i'://INVITE，发起呼叫请求
i = eXosip_call_build_initial_invite(excontext, &invite, dest_call, source_call, NULL, "This is a call for conversation");
if (i != 0)
{
printf("Initial INVITE failed!\n");
break;
}
//符合SDP格式，其中属性a是自定义格式，也就是说可以存放自己的信息，
//但是只能有两列，比如帐户信息
//但是经过测试，格式vot必不可少，原因未知，估计是协议栈在传输时需要检查的
_snprintf_s(tmp, 4096,
"v=0\r\n"
"o=anonymous 0 0 IN IP4 0.0.0.0\r\n"
"t=0 0\r\n"
"m=audio 62100 RTP/AVP 114 0 8 101\r\n"
"a=rtpmap:114 AMR/8000\r\n"
"a=fmtp:114 octet-align=1;mode-set=7,0\r\n"
"a=rtpmap:0 PCMU/8000\r\n"
"a=rtpmap:8 PCMA/8000\r\n"
"m=video 62102 RTP/AVP 102 99\r\n"
"a=rtpmap:102 H264/90000\r\n"
"a=rtpmap:99 MP4V-ES/90000\r\n"
);
osip_message_set_body(invite, tmp, strlen(tmp));
osip_message_set_content_type(invite, "application/sdp");
eXosip_lock(excontext);
i = eXosip_call_send_initial_invite(excontext, invite); //invite SIP INVITE message to send
eXosip_unlock(excontext);
//发送了INVITE消息，等待应答
flag1 = 1;
while (flag1)
{
je = eXosip_event_wait(excontext, 0, 200); //Wait for an eXosip event
//(超时时间秒，超时时间毫秒)
if (je == NULL)
{
printf("No response or the time is over!\n");
break;
}
switch (je->type) //可能会到来的事件类型
{
case EXOSIP_CALL_INVITE: //收到一个INVITE请求
printf("a new invite received!\n");
break;
case EXOSIP_CALL_PROCEEDING: //收到100 trying消息，表示请求正在处理中
printf("proceeding!\n");
break;
case EXOSIP_CALL_RINGING: //收到180 Ringing应答，表示接收到INVITE请求的UAS正在向被叫用户振铃
printf("ringing!\n");
printf("call_id is %d,dialog_id is %d \n", je->cid, je->did);
break;
case EXOSIP_CALL_ANSWERED: //收到200 OK，表示请求已经被成功接受，用户应答
printf("ok!connected!\n");
call_id = je->cid;
dialog_id = je->did;
printf("call_id is %d,dialog_id is %d \n", je->cid, je->did);
//回送ack应答消息
eXosip_call_build_ack(excontext, je->did, &ack);
eXosip_call_send_ack(excontext, je->did, ack);
flag1 = 0; //推出While循环
break;
case EXOSIP_CALL_CLOSED: //a BYE was received for this call
printf("the other sid closed!\n");
break;
case EXOSIP_CALL_ACK: //ACK received for 200ok to INVITE
printf("ACK received!\n");
break;
default: //收到其他应答
printf("other response!\n");
break;
}
eXosip_event_free(je); //Free ressource in an eXosip event
}
break;
case 'h': //挂断
printf("Holded!\n");
eXosip_lock(excontext);
eXosip_call_terminate(excontext, call_id, dialog_id);
eXosip_unlock(excontext);
break;
case 'c':
printf("This modal is not commpleted!\n");
break;
case 's': //传输INFO方法
eXosip_call_build_info(excontext, dialog_id, &info);
_snprintf_s(tmp, 4096, "\nThis is a sip message(Method:INFO)");
osip_message_set_body(info, tmp, strlen(tmp));
//格式可以任意设定，text/plain代表文本信息;
osip_message_set_content_type(info, "text/plain");
eXosip_call_send_request(excontext, dialog_id, info);
break;
case 'm':
//传输MESSAGE方法，也就是即时消息，和INFO方法相比，我认为主要区别是：
//MESSAGE不用建立连接，直接传输信息，而INFO消息必须在建立INVITE的基础上传输
printf("the method : MESSAGE\n");
eXosip_message_build_request(excontext, &message, "MESSAGE", dest_call, source_call, NULL);
//内容，方法， to ，from ，route
_snprintf_s(tmp, 4096, "This is a sip message(Method:MESSAGE)");
osip_message_set_body(message, tmp, strlen(tmp));
//假设格式是xml
osip_message_set_content_type(message, "text/xml");
eXosip_message_send_request(excontext, message);
break;
case 'q':
eXosip_quit(excontext);
printf("Exit the setup!\n");
flag = 0;
break;
}
}
osip_free(excontext);
return(0);
}
invite sdp 格式参照如下：
INVITE sip:[email protected]:5060 SIP/2.0
Via: SIP/2.0/UDP 10.4.46.1:49552;rport;branch=z9hG4bK2032385714
From:
To:
Call-ID: 3012165000
CSeq: 21 INVITE
Contact:
Proxy-Authorization: Digest username="8006", realm="BCC", nonce="0af1a282e6687dc7fe2442989bf23ea4", uri="sip:[email protected]:5060", response="51f136f0c58570397ba1b94c256d12b9", algorithm=MD5
Content-Type: application/sdp
Call-Info:
Max-Forwards: 70
User-Agent: #SDK Console 3.0
Subject: ## Dispatch Console!
Content-Length: 307
v=0
o=DConsole 1 1 IN IP4 10.4.46.1
s=##DConsole demo
c=IN IP4 10.4.46.1
t=0 0
m=audio 62100 RTP/AVP 114 0 8 101
a=rtpmap:114 AMR/8000
a=fmtp:114 octet-align=1;mode-set=7,0
a=rtpmap:0 PCMU/8000
a=rtpmap:8 PCMA/8000
m=video 62102 RTP/AVP 102 99
a=rtpmap:102 H264/90000
a=rtpmap:99 MP4V-ES/90000
3、复制如下代码生成UAS，该实例使用的是windows控制台程序，对于sdp的解析部分需修改一下，请参照音频的获取方式修改视频sdp解析代码。
代码如下:
# include
# include
# include
# include
int main(int argc, char *argv[])
{
eXosip_event_t *je = NULL;
osip_message_t *ack = NULL;
osip_message_t *invite = NULL;
osip_message_t *answer = NULL;
sdp_message_t *remote_sdp = NULL;
int call_id, dialog_id;
int i, j;
int id;
char *sour_call = "sip:[email protected]";
char *dest_call = "sip:[email protected]:15060";//client ip
char command;
char tmp[4096];
char localip[128];
int pos = 0;
//初始化sip
struct eXosip_t *excontext;
excontext = eXosip_malloc();
i = eXosip_init(excontext);
if (i != 0)
{
printf("Can't initialize eXosip!\n");
return -1;
}
else
{
printf("eXosip_init successfully!\n");
}
i = eXosip_listen_addr(excontext, IPPROTO_UDP, NULL, 15061, AF_INET, 0);
if (i != 0)
{
eXosip_quit(excontext);
fprintf(stderr, "eXosip_listen_addr error!\nCouldn't initialize transport layer!\n");
}
for (;;)
{
//侦听是否有消息到来
je = eXosip_event_wait(excontext, 0, 50);
//协议栈带有此语句,具体作用未知
eXosip_lock(excontext);
eXosip_default_action(excontext, je);
//eXosip_automatic_refresh();
eXosip_automatic_action(excontext);
eXosip_unlock(excontext);
if (je == NULL)//没有接收到消息
continue;
// printf ("the cid is %s, did is %s/n", je->did, je->cid);
switch (je->type)
{
case EXOSIP_MESSAGE_NEW://新的消息到来
printf(" EXOSIP_MESSAGE_NEW!\n");
if (MSG_IS_MESSAGE(je->request))//如果接受到的消息类型是MESSAGE
{
{
osip_body_t *body;
osip_message_get_body(je->request, 0, &body);
printf("I get the msg is: %s\n", body->body);
//printf ("the cid is %s, did is %s/n", je->did, je->cid);
}
//按照规则，需要回复OK信息
eXosip_message_build_answer(excontext, je->tid, 200, &answer);
eXosip_message_send_answer(excontext, je->tid, 200, answer);
}
break;
case EXOSIP_CALL_INVITE:
{ //得到接收到消息的具体信息
printf("Received a INVITE msg from %s:%s, UserName is %s, password is %s\n", je->request->req_uri->host,
je->request->req_uri->port, je->request->req_uri->username, je->request->req_uri->password);
//得到消息体,认为该消息就是SDP格式.
remote_sdp = eXosip_get_remote_sdp(excontext, je->did);
call_id = je->cid;
dialog_id = je->did;
eXosip_lock(excontext);
eXosip_call_send_answer(excontext, je->tid, 180, NULL);
i = eXosip_call_build_answer(excontext, je->tid, 200, &answer);
if (i != 0)
{
printf("This request msg is invalid!Cann't response!\n");
eXosip_call_send_answer(excontext, je->tid, 400, NULL);
}
else
{
_snprintf_s(tmp, 4096,
"v=0\r\n"
"o=anonymous 0 0 IN IP4 0.0.0.0\r\n"
"t=1 10\r\n");
//设置回复的SDP消息体,下一步计划分析消息体
//没有分析消息体，直接回复原来的消息，这一块做的不好。
osip_message_set_body(answer, tmp, strlen(tmp));
osip_message_set_content_type(answer, "application/sdp");
eXosip_call_send_answer(excontext, je->tid, 200, answer);
printf("send 200 over!\n");
}
eXosip_unlock(excontext);
//显示出在sdp消息体中的attribute 的内容,里面计划存放我们的信息
printf("the INFO is :\n");
//sdp_media_t *connection = eXosip_get_audio_media(remote_sdp);
//if (!connection)
// return false;
//char* audio_ip = connection->c_addr; //audio_ip
sdp_media_t * audio_sdp = eXosip_get_audio_media(remote_sdp);
if (!audio_sdp)
return false;
char* audio_port = audio_sdp->m_port; //audio_port
for (int i = 0; i < audio_sdp->a_attributes.nb_elt; i++)
{
sdp_attribute_t *attr = (sdp_attribute_t*)osip_list_get(&audio_sdp->a_attributes, i);
printf("%s : %s\n", attr->a_att_field, attr->a_att_value);
}
while (!osip_list_eol(&(remote_sdp->a_attributes), pos))
{
sdp_attribute_t *at;
at = (sdp_attribute_t *)osip_list_get(&remote_sdp->a_attributes, pos);
printf("%s : %s\n", at->a_att_field, at->a_att_value);//这里解释了为什么在SDP消息体中属性a里面存放必须是两列
pos++;
}
while (!osip_list_eol(&(remote_sdp->m_medias), pos))
{
sdp_attribute_t *at;
at = (sdp_attribute_t *)osip_list_get(&remote_sdp->m_medias, pos);
printf("%s : %s\n", at->a_att_field, at->a_att_value);//这里解释了为什么在SDP消息体中属性a里面存放必须是两列
pos++;
}
}
break;
case EXOSIP_CALL_ACK:
printf("ACK recieved!\n");
// printf ("the cid is %s, did is %s/n", je->did, je->cid);
break;
case EXOSIP_CALL_CLOSED:
printf("the remote hold the session!\n");
// eXosip_call_build_ack(dialog_id, &ack);
//eXosip_call_send_ack(dialog_id, ack);
i = eXosip_call_build_answer(excontext, je->tid, 200, &answer);
if (i != 0)
{
printf("This request msg is invalid!Cann't response!\n");
eXosip_call_send_answer(excontext, je->tid, 400, NULL);
}
else
{
eXosip_call_send_answer(excontext, je->tid, 200, answer);
printf("bye send 200 over!\n");
}
break;
case EXOSIP_CALL_MESSAGE_NEW://至于该类型和EXOSIP_MESSAGE_NEW的区别，源代码这么解释的
/*
// request related events within calls (except INVITE)
EXOSIP_CALL_MESSAGE_NEW, < announce new incoming request.
// response received for request outside calls
EXOSIP_MESSAGE_NEW, < announce new incoming request.
我也不是很明白，理解是：EXOSIP_CALL_MESSAGE_NEW是一个呼叫中的新的消息到来，比如ring trying都算，所以在接受到后必须判断
该消息类型，EXOSIP_MESSAGE_NEW而是表示不是呼叫内的消息到来。
该解释有不妥地方，仅供参考。
*/
printf(" EXOSIP_CALL_MESSAGE_NEW\n");
if (MSG_IS_INFO(je->request)) //如果传输的是INFO方法
{
eXosip_lock(excontext);
i = eXosip_call_build_answer(excontext, je->tid, 200, &answer);
if (i == 0)
{
eXosip_call_send_answer(excontext, je->tid, 200, answer);
}
eXosip_unlock(excontext);
{
osip_body_t *body;
osip_message_get_body(je->request, 0, &body);
printf("the body is %s\n", body->body);
}
}
break;
default:
printf("Could not parse the msg!\n");
}
}
} UAS 回复的sdp 格式请参照
SIP/2.0 200 OK
Via: SIP/2.0/UDP 10.4.46.1:49552;rport=49552;branch=z9hG4bK2032385714
From:
To:
Call-ID: 3012165000
CSeq: 21 INVITE
Contact:
Content-Type: application/sdp
Call-Info:
User-agent: BCC/3.0
Content-Length: 215
v=0
o=B2BUA 1 1 IN IP4 10.4.54.2
s=BCC Switch
c=IN IP4 10.4.54.2
t=0 0
m=audio 26438 RTP/AVP 114
a=rtpmap:114 AMR/8000
a=fmtp:114 octet-align=1;mode-set=7
m=video 26442 RTP/AVP 102
a=rtpmap:102 H264/90000
4、以上程序的ip请修改成自己实际电脑的ip，根据UAC和UAS协商好的端口即可进行收流解析播放。
5、有问题可以给我留言 一起探讨。
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版权声明：本文为CSDN博主「zzqgtt」的原创文章，遵循 CC 4.0 BY-SA 版权协议，转载请附上原文出处链接及本声明。
原文链接：https://blog.csdn.net/zzqgtt/article/details/87179815