ipp-server/lib/bind.js

Create a printer on the network

"use strict";

var util       = require("util");
var os         = require("os");
var http       = require("http");
var ipp        = require("ipp-encoder");
var debug      = require("debug")(require("../package").name);
var groups     = require("./groups");
var operations = require("./operations");

var C = ipp.CONSTANTS;

module.exports = function (printer) {
	var server  = printer.server;

	if (server) {
		server.on("request", onrequest);

		if (server.address()) {
			onlistening();
		} else {
			server.on("listening", onlistening);
		}
	} else {
		server = printer.server = http.createServer(onrequest);

		server.listen(printer.port, onlistening);
	}

	return printer;

	function onrequest(req, res) {
		debug("HTTP request: %s %s", req.method, req.url);

		if (req.method !== "POST") {
			res.writeHead(405);
			return res.end();
		}
		if (req.headers["content-type"] !== "application/ipp") {
			res.writeHead(400);
			return res.end();
		}

		req.on("data", consumeAttrGroups);
		req.on("end", fail);

		function consumeAttrGroups(chunk) {
			req._body = req._body ? Buffer.concat([req._body, chunk]) : chunk;

			try {
				req._body = ipp.request.decode(req._body);
			} catch (e) {
				return debug("incomplete IPP body - waiting for more data...");
			}

			req.removeListener("data", consumeAttrGroups);
			req.removeListener("end", fail);

			printer.emit("operation", req._body);

			router(printer, req, res);
		}

		function fail() {
			// decode only the most essential part of the IPP request header to allow
			// best possible response
			if (req._body.length >= 8) {
				var body = {
					version     : {
						major : req._body.readInt8(0),
						minor : req._body.readInt8(1)
					},
					operationId : req._body.readInt16BE(2),
					requestId   : req._body.readInt32BE(4)
				};
			}

			send(printer, body, res, C.CLIENT_ERROR_BAD_REQUEST);
		}
	}

	function onlistening() {
		printer.port = server.address().port;

		if (!printer.uri) {
			printer.uri = "ipp://" + os.hostname() + ":" + printer.port + "/";
		}

		debug("printer \"%s\" is listening on %s", printer.name, printer.uri);

		printer.start();

		if (printer._zeroconf) {
			debug("advertising printer \"%s\" on network on port %s", printer.name, printer.port);
		}
	}
}

function router(printer, req, res) {
	var body               = req._body;
	var checkAuthorization = typeof printer.authorize == "function"
	                       ? printer.authorize
	                       : function (req, res, body, next) { return next(); };

	debug("IPP/%d.%d operation %d (request #%d)",
		body.version.major,
		body.version.minor,
		body.operationId,
		body.requestId,
		util.inspect(body.groups, { depth: null }));

	res.send = send.bind(null, printer, body, res);

	if (body.version.major !== 1) {
		return res.send(C.SERVER_ERROR_VERSION_NOT_SUPPORTED);
	}

	checkAuthorization(req, res, body, function () {
		switch (body.operationId) {
			// Printer Operations
			case C.PRINT_JOB:              return operations.printJob(printer, req, res);
			case C.VALIDATE_JOB:           return operations.validateJob(printer, req, res);
			case C.GET_PRINTER_ATTRIBUTES: return operations.getPrinterAttributes(printer, req, res);
			case C.GET_JOBS:               return operations.getJobs(printer, req, res);

			// Job Operations
			case C.CANCEL_JOB:             return operations.cancelJob(printer, req, res);
			case C.GET_JOB_ATTRIBUTES:     return operations.getJobAttributes(printer, req, res);

			default: res.send(C.SERVER_ERROR_OPERATION_NOT_SUPPORTED);
		}
	});
}

function send(printer, req, res, statusCode, _groups) {
	if (typeof statusCode === "object") {
		return send(printer, req, res, C.SUCCESSFUL_OK, statusCode);
	}

	if (statusCode === undefined) {
		statusCode = C.SUCCESSFUL_OK;
	}

	var obj = {};

	if (printer.fallback && req && req.version.major === 1 && req.version.minor === 0) {
		obj.version = { major: 1, minor: 0 };
	}

	obj.statusCode = statusCode;
	obj.requestId  = req ? req.requestId : 0;
	obj.groups     = [ groups.operationAttributesTag(ipp.STATUS_CODES[statusCode]) ];

	if (_groups) obj.groups = obj.groups.concat(_groups);

	debug("responding to request #%d", obj.requestId, util.inspect(obj, { depth: null }));

	var buf = ipp.response.encode(obj);

	res.writeHead(200, {
		"Content-Length" : buf.length,
		"Content-Type"   : "application/ipp"
	});

	res.end(buf);
}