視訊監控安防平臺-GB28181-exosip協議棧重新整理訂閱

由於之前的sip協議棧是自己寫的所以對傳送訂閱訊息和相應規定都是自己組裝，這次嘗試使用exosip來進行訂閱，發現不能單純的呼叫訂閱，必須呼叫協議棧裡面的初始化訂閱和重新整理訂閱，理解好之後，構造程式碼測試，發現還是不通，以為是協議棧不支援重新整理訂閱，就一步一步的除錯，跟到協議棧內部發現不是這麼簡單，是exosip協議棧有問題，明明根據sid找到相應的訂閱資訊，但是返回的時候還是null， 發現是協議棧的問題，修改協議棧原始碼，重新編譯。那麼採用exosip重新整理訂閱的問題就迎刃而解。

        下面講解下解決問題的思路：

採用eXosip_subscribe_build_refresh_request來進行重新整理訂閱，在除錯程式碼的發現eXosip_subscribe_dialog_find這個函式返回出來的jd == NULL始終是錯誤的，下面就跟到int eXosip_subscribe_dialog_find(int sid， eXosip_subscribe_t ** js, eXosip_dialog_t ** jd)這個函式，發現通過 sid能找到相應的eXosip_subscribe_t，問題出現在

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

不難看出找到sid之後直接返回成功，那麼現在就是解決問題，需要把eXosip_dialog_t ** jd這個引數返回出去，下面就是修改原始碼：

//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;
}

紅色部分為修改內容。這樣重新整理訂閱就沒問題了。

下面貼上下訂閱和重新整理訂閱的程式碼，提供一段系統目錄訂閱的函式：

//send subscribe
int CSExtRegister::SendSubSribe(void)
{
	//構建目錄訂閱程式碼
	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)
	{
		//構建to地址
		char PToStr[128] = "";
		sprintf(PToStr,"sip:%
 
[email protected]%s:%d", Username, EpReg.TvsAddr.OutIpAddr, EpReg.TvsAddr.OutPort);
		char Proxy[SIP_AOR_MAX_SIZE+1] = "";
		snprintf(Proxy,SIP_AOR_MAX_SIZE, "sip:%[email protected]%s:%d",Username, EpReg.TvsAddr.OutIpAddr, EpReg.TvsAddr.OutPort);
		char Contact[SIP_AOR_MAX_SIZE+1] = "";
		snprintf(Contact, SIP_AOR_MAX_SIZE, "sip:%[email protected]%s:%d", CSBase::m_SipSvrPubID, CSBase::m_MyIpAddr, CSBase::m_MyPort);

		//第一次構造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
	{
		//重新整理構建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;
}