Method matchMessage

SIP/SIPBase.cpp:1264–1287

Does this incoming message want to be processed by this dialog? NOTE: This is temporary until we fully support SipTransactions, in which case this will be used only for in-dialog requests, and in that case both to- and from-tags must match. This may not be correct for group calls - we may want to search each of several possible matching dialogs for the transaction matching the via-branch.

// This may not be correct for group calls - we may want to search each of several possible
// matching dialogs for the transaction matching the via-branch.
bool SipBase::matchMessage(SipMessage *msg)
{
	// The caller already checked the callid, but lets do it again in case someone modifies the code later.
	if (msg->smGetCallId() != this->callId()) { return false; }
	// This code could be simplified by combining logic, but I left it verbose for clarity
	if (msg->isRequest()) {
		// If it is a request sent by the peer, the remote tag must match.  Both empty is ok.
		if (msg->smGetRemoteTag() != this->dsRemoteTag()) { return false; }
		// The local tag in the message is either empty (meaning the peer has not received it yet) or matches.
		string msgLocalTag = msg->smGetLocalTag();
		if (! msgLocalTag.empty()) {
			if (msgLocalTag != this->dsLocalTag()) { return false; }
		}
	} else {
		// If it is a reply, it means the original request was sent by us.  The local tags must match.  Both empty is ok.
		if (msg->smGetLocalTag() != this->dsLocalTag()) { return false; }
		// The remote tag in the dialog is either empty (has not been set yet, will probably be set by this message), or matches.
		string remoteTag = dsRemoteTag();
		if (! remoteTag.empty()) {
			if (remoteTag != msg->smGetRemoteTag()) { return false; }
		}
	}
	return true;	// Good enough.
}


// 17.2.3 tells how to match requests to server transactions, but that does not apply to this.