视频监控安防平台-GB28181-exosip协议栈系统刷新订阅

                             视频监控安防平台-GB28181-exosip协议栈刷新订阅

由于之前的sip协议栈是自己写的所以对发送订阅消息和相应规定都是自己组装，这次尝试使用exosip来进行订阅，发现不能单纯的调用订阅，必须调用协议栈里面的初始化订阅和刷新订阅，理解好之后，构造代码测试，发现还是不通，以为是协议栈不支持刷新订阅，就一步一步的调试，跟到协议栈内部发现不是这么简单，是exosip协议栈有问题，明明根据sid找到相应的订阅信息，但是返回的时候还是null， 发现是协议栈的问题，修改协议栈源码，重新编译。那么采用exosip刷新订阅的问题就迎刃而解。

        下面讲解下解决问题的思路：

采用eXosip_subscribe_build_refresh_request来进行刷新订阅，在调试代码的发现eXosip_subscribe_dialog_find这个函数返回出来的jd == NULL始终是错误的，下面就跟到int eXosip_subscribe_dialog_find(int sid， eXosip_subscribe_t ** js, eXosip_dialog_t ** jd)这个函数，发现通过 sid能找到相应的eXosip_subscribe_t，问题出现在

if ((*js)->s_id == sid)
return OSIP_SUCCESS;

不难看出找到sid之后直接返回成功，那么现在就是解决问题，需要把eXosip_dialog_t ** jd这个参数返回出去，下面就是修改源码：

//if ((*js)->s_id == sid)
//return OSIP_SUCCESS;
// modify by songxw 2017-12-01
if ((*js)->s_id == sid)
{
*jd = (*js)->s_dialogs;
return OSIP_SUCCESS;
}

红色部分为修改内容。这样刷新订阅就没问题了。

下面粘贴下订阅和刷新订阅的代码，提供一段系统目录订阅的函数：

//send subscribe
int CSExtRegister::SendSubSribe(void)
{
	//构建目录订阅代码
	string strSubXml = "";
	TCatalogSubscriReq CatalogSubscriReq;
	CatalogSubscriReq.nSn = GetSipBodySN();
	CatalogSubscriReq.strDevId = Username;
	CatalogSubscriReq.strBeginTime = "";
	CatalogSubscriReq.strEndTime = ""; 
	BuildMsg(E_PT_CATALOG_SUBCRI_REQ,&CatalogSubscriReq, strSubXml, E_TRANPRO_SUBSCRIBE);

	int iRet = -1;
	osip_message_t* pSubScribeMsg = NULL; 
	if (m_SubCatalogTid <= 0)
	{
		//构建to地址
		char PToStr[128] = "";
		sprintf(PToStr,"sip:%s@%s:%d", Username, EpReg.TvsAddr.OutIpAddr, EpReg.TvsAddr.OutPort);
		char Proxy[SIP_AOR_MAX_SIZE+1] = "";
		snprintf(Proxy,SIP_AOR_MAX_SIZE, "sip:%s@%s:%d",Username, EpReg.TvsAddr.OutIpAddr, EpReg.TvsAddr.OutPort);
		char Contact[SIP_AOR_MAX_SIZE+1] = "";
		snprintf(Contact, SIP_AOR_MAX_SIZE, "sip:%s@%s:%d", CSBase::m_SipSvrPubID, CSBase::m_MyIpAddr, CSBase::m_MyPort);

		//第一次构造subscribe
		iRet = eXosip_subscribe_build_initial_request(&pSubScribeMsg, PToStr, CSBase::m_From, Proxy, "presence", m_SubCatalogTime);
		if (iRet != OSIP_SUCCESS || pSubScribeMsg == NULL)
		{
			DBGPrint(M_SipUA, ERROR_LEVEL, "%s: build initial subscribe error for <%s>, iRet<%d>!", __FUNCTION__, Username, iRet);
			return -1;
		}
		
		osip_message_set_content_type(pSubScribeMsg, "Application/MANSCDP+xml");
		osip_message_set_body(pSubScribeMsg, strSubXml.c_str(), strlen(strSubXml.c_str()));
		//osip_message_set_contact(pSubScribeMsg, TmpBuf);
	
		m_SubCatalogTid = eXosip_subscribe_send_initial_request(pSubScribeMsg);
		if (m_SubCatalogTid <= 0)
		{
			DBGPrint(M_SipUA, ERROR_LEVEL, "%s: send subscribe error for <%s>, m_SubCatalogTid<%d>!", __FUNCTION__, Username, m_SubCatalogTid);	
			return -1;
		}
	}
	else
	{
		//刷新构建subscrbe
		iRet = eXosip_subscribe_build_refresh_request(m_SubCatalogTid, &pSubScribeMsg);
		if (iRet != OSIP_SUCCESS || pSubScribeMsg == NULL)
		{
			DBGPrint(M_SipUA, ERROR_LEVEL, "%s: build refresh subscribe error for <%s>, iRet<%d>!", __FUNCTION__, Username, iRet);
			return -1;
		}
		char        	TmpBuf[CLIP_BUFFER_SIZE+1] = {0};
		snprintf(TmpBuf, CLIP_BUFFER_SIZE, "%d", m_SubCatalogTime);
		osip_message_set_expires(pSubScribeMsg, TmpBuf);
		osip_message_set_content_type(pSubScribeMsg, "Application/MANSCDP+xml");
		osip_message_set_body(pSubScribeMsg, strSubXml.c_str(), strlen(strSubXml.c_str()));

		if (eXosip_subscribe_send_refresh_request(m_SubCatalogTid, pSubScribeMsg) != OSIP_SUCCESS)
		{
			DBGPrint(M_SipUA, ERROR_LEVEL, "%s: send refresh subscribe error for <%s>, iRet<%d>!", __FUNCTION__, Username, iRet);
			return -1;
		}
	}
	
	return 0;
}