sipprocessor.cpp

a open source project in linux for peer to peer on seep

	// Forward INVITE to callee
	string tempIP(calleeSocket->RemoteIPAddress().GetAddressString());
	log->debug("Forwarding ACK Message to: IP = " + tempIP + ", port = ", calleeSocket->RemotePortNumber());
	bytesTransferred = calleeSocket->SendDatagram(originalRequest.c_str(), originalRequest.size());
	log->debug(" - sent bytes: ", bytesTransferred);
	
	*/
}

void SipProcessor::sendServerError() {
	string response = "SERVER ERROR";
	serverSocket->SendDatagram(response.c_str(), response.size(), *callerIPSource, callerPort);
	log->debug("SERVER ERROR sent to caller.");
}

void SipProcessor::sendRequestNotSupported() {
	string response = "REQUEST NOT SUPPORTED";
	serverSocket->SendDatagram(response.c_str(), response.size(), *callerIPSource, callerPort);
	log->debug("REQUEST NOT SUPPORTED sent to caller.");
}

void SipProcessor::sendInvalidRequest() {
	string response = "INVALID REQUEST";
	serverSocket->SendDatagram(response.c_str(), response.size(), *callerIPSource, callerPort);
	log->debug("INVALID REQUEST sent to caller.");
}

void SipProcessor::sendNotFound() {
	string response = "NOT FOUND";
	serverSocket->SendDatagram(response.c_str(), response.size(), *callerIPSource, callerPort);
	log->debug("NOT FOUND sent to caller.");
}


const string SipProcessor::prepareInvite() {
	istringstream is(originalRequest);
	string line;
	
	// First iterate over the request, to find the <To: XXX> line
	// When found, seach in Kademlia network for real data
	// Then iterate over the request again, replace the old
	// To data with the one found in kademlia network
	
	for (getline(is, line); line != ""; getline(is, line)) {
		if (line.find("To:") == 0) {
			if (!splitContactData(line)) {
				log->debug("Error reading contact data from line: " + line);
				sendInvalidRequest();
				return "";
			}
			break;
		}
	}
	
	// Now search for data in kademlia
	Database* api = Database::getInstance();
	string foundData = api->get(responseContact[0]);
	if (foundData == "") {
		log->debug("Name '" + responseContact[0] + "' not found in kademlia!");
		sendNotFound();
		return "";
	}
	
	int index = foundData.find("@");
	responseContact[0] = foundData.substr(0, index);	// name
	responseContact[1] = foundData.substr(index + 1);	// ip + port
	
	index = responseContact[1].find(":");
	
	if (index == -1) {
		responseContact[2] = "5060"; 	// def port
	} else {
		responseContact[2] = responseContact[1].substr(index +1); 	// port
		responseContact[1] = responseContact[1].substr(0, index);	// IP adr
	}
	
	// The data should be prepared. Now generate the response
	ostringstream response;
	is.str(originalRequest);
	
	// Copy needed lines from request to response
	int emptyLines = 0;
	for (getline(is, line); emptyLines < 2; getline(is, line)) {
		if (line == "") {
			// Count empty lines, after two of them we are done
			response << line << endl;
			emptyLines++;
		} else if (line.find(INVITE) == 0) {
			// Replace values in header
			response << INVITE << " sip:" << responseContact[0] << "@" << responseContact[1] << " SIP/2.0" << endl;
		} else if (line.find("To:") == 0) {
			// Replace values in To: field
			response << "To: <sip:" << responseContact[0] << "@" << responseContact[1] << ":" << responseContact[2] << ">" << endl;
		} else {
			// Else just copy the line
			response << line << endl;
		} 
	}
	response << endl;
	return response.str();
}

const string SipProcessor::createTryingMessage() {
	istringstream is(originalRequest);
	ostringstream responseStream;
	string line;
	
	responseStream << SIP_HEADER_TRYING << endl;
	// Copy needed lines from request to response
	for (getline(is, line); line != ""; getline(is, line)) {
		if (line.find("Via:") == 0) {
			responseStream << line << endl;
		} else if (line.find("To:") == 0) {
			responseStream << line << endl;
		} else if (line.find("Contact:") == 0) {
			responseStream << line << endl;
		} else if (line.find("From:") == 0) {
			responseStream << line << endl;
		} else if (line.find("Call-ID:") == 0) {
			responseStream << line << endl;
		} else if (line.find("Server:") == 0) {
			responseStream << line << endl;
		} else if (line.find("Content-Length:") == 0) {
			responseStream << "Content-Length: 0" << endl << endl;
		} 
	}
	
	// Everything ok -> return created message;
	return responseStream.str();
}

const string SipProcessor::createRedirectionMessage() {
	istringstream is(originalRequest);
	string line;
	
	string foundData = "";
	
	// Firs search the for the TO field, and get data
	for (getline(is, line); line != ""; getline(is, line)) {
		if (line.find("To:") == 0) {
			if (!splitContactData(line)) {
				log->debug("Error reading contact data from line: " + line);
				sendInvalidRequest();
				return "";
			}
			// Now search for data in kademlia
			Database* api = Database::getInstance();
			log->debug("Searching for " + responseContact[0]);
			foundData = api->get(responseContact[0]);
			log->debug("Found " + foundData);
			if (foundData == "") {
				log->debug("Name '" + responseContact[0] + "' not found in kademlia!");
				sendNotFound();
				return "";
			}
		} 
	}
	
	log->debug("Data found, prepare redirection");
	istringstream is2(originalRequest);
	ostringstream responseStream;
	
	responseStream << SIP_HEADER_MOVED_TEMPORARILY << endl;
	
	for (getline(is2, line); line != ""; getline(is2, line)) {
		if (line.find("Via:") == 0) {
			string tempLine = "Via: SIP/2.0/UDP 80.108.236.241:5063;rport;branch=z9hG4bKowbwhxec";
			responseStream << tempLine << endl;
			responseStream << line << endl;
		} else if (line.find("To:") == 0) {
			responseStream << "To: <sip:" + foundData + ">" << endl;
		} else if (line.find("From:") == 0) {
			responseStream << line << endl;
		} else if (line.find("Contact:") == 0) {
			responseStream << "Contact: <sip:" + foundData + ">" << endl;
		} else if (line.find("Call-ID:") == 0) {
			responseStream << line << endl;
		} else if (line.find("CSeq:") == 0) {
			responseStream << line << endl;
		} else if (line.find("Content-Length:") == 0) {
			responseStream << "Content-Length: 0" << endl << endl;
		} 
	}
	
	
	// Everything ok -> return created message;
	log->debug("Exiting...");
	return responseStream.str();
}

/** 
 * Prepare contact data
 */
bool SipProcessor::splitContactData(const string& cl) {
	string contactLine = cl;
	int index = contactLine.find("<sip:");
	int index2 = contactLine.find(">");
	if (index == -1 || index2 ==-1) {
		return false;
	}
	contactLine = contactLine.substr(index + 5, index2 - index - 5);
	index = contactLine.find("@");
	if (index == -1) {
		return false;
	}
	
	string name = contactLine.substr(0, index);
	string ipAddress = contactLine.substr(index + 1);
	string port = "";
	index = ipAddress.find(":");
	if (index != -1) {
		port = ipAddress.substr(index+1);
		ipAddress = ipAddress.substr(0, index);
	}
	
	responseContact[0] = name;
	responseContact[1] = ipAddress;
	responseContact[2] = port;
	log->debug("PORT = " + port);
	return true;
}

/** 
 * Gets current date and time in format prepared for SIP.
 */
const string SipProcessor::getDateAndTime() {
	time_t rawtime;
	struct tm * timeinfo;
	time(&rawtime);
	timeinfo = localtime(&rawtime);
	char* now = asctime(timeinfo);
    string nfdt(now);
    
    string fdt;
    
    fdt += nfdt.substr(0, 3) + ", ";	// day in week
    fdt += nfdt.substr(8, 2) + " ";	// date
    fdt += nfdt.substr(4, 3) + " ";	// Month
    fdt += nfdt.substr(20, 4) + " ";	// year
    fdt += nfdt.substr(11, 8) + " GMT";

    return fdt;
}