"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.downloadTo = exports.uploadFrom = exports.connectForPassiveTransfer = exports.parsePasvResponse = exports.enterPassiveModeIPv4 = exports.parseEpsvResponse = exports.enterPassiveModeIPv6 = void 0;
const netUtils_1 = require("./netUtils");
const stream_1 = require("stream");
const tls_1 = require("tls");
const parseControlResponse_1 = require("./parseControlResponse");
/**
* Prepare a data socket using passive mode over IPv6.
*/
async function enterPassiveModeIPv6(ftp) {
const res = await ftp.request("EPSV");
const port = parseEpsvResponse(res.message);
if (!port) {
throw new Error("Can't parse EPSV response: " + res.message);
}
const controlHost = ftp.socket.remoteAddress;
if (controlHost === undefined) {
throw new Error("Control socket is disconnected, can't get remote address.");
}
await connectForPassiveTransfer(controlHost, port, ftp);
return res;
}
exports.enterPassiveModeIPv6 = enterPassiveModeIPv6;
/**
* Parse an EPSV response. Returns only the port as in EPSV the host of the control connection is used.
*/
function parseEpsvResponse(message) {
// Get port from EPSV response, e.g. "229 Entering Extended Passive Mode (|||6446|)"
// Some FTP Servers such as the one on IBM i (OS/400) use ! instead of | in their EPSV response.
const groups = message.match(/[|!]{3}(.+)[|!]/);
if (groups === null || groups[1] === undefined) {
throw new Error(`Can't parse response to 'EPSV': ${message}`);
}
const port = parseInt(groups[1], 10);
if (Number.isNaN(port)) {
throw new Error(`Can't parse response to 'EPSV', port is not a number: ${message}`);
}
return port;
}
exports.parseEpsvResponse = parseEpsvResponse;
/**
* Prepare a data socket using passive mode over IPv4.
*/
async function enterPassiveModeIPv4(ftp) {
const res = await ftp.request("PASV");
const target = parsePasvResponse(res.message);
if (!target) {
throw new Error("Can't parse PASV response: " + res.message);
}
// If the host in the PASV response has a local address while the control connection hasn't,
// we assume a NAT issue and use the IP of the control connection as the target for the data connection.
// We can't always perform this replacement because it's possible (although unlikely) that the FTP server
// indeed uses a different host for data connections.
const controlHost = ftp.socket.remoteAddress;
if ((0, netUtils_1.ipIsPrivateV4Address)(target.host) && controlHost && !(0, netUtils_1.ipIsPrivateV4Address)(controlHost)) {
target.host = controlHost;
}
await connectForPassiveTransfer(target.host, target.port, ftp);
return res;
}
exports.enterPassiveModeIPv4 = enterPassiveModeIPv4;
/**
* Parse a PASV response.
*/
function parsePasvResponse(message) {
// Get host and port from PASV response, e.g. "227 Entering Passive Mode (192,168,1,100,10,229)"
const groups = message.match(/([-\d]+,[-\d]+,[-\d]+,[-\d]+),([-\d]+),([-\d]+)/);
if (groups === null || groups.length !== 4) {
throw new Error(`Can't parse response to 'PASV': ${message}`);
}
return {
host: groups[1].replace(/,/g, "."),
port: (parseInt(groups[2], 10) & 255) * 256 + (parseInt(groups[3], 10) & 255)
};
}
exports.parsePasvResponse = parsePasvResponse;
function connectForPassiveTransfer(host, port, ftp) {
return new Promise((resolve, reject) => {
let socket = ftp._newSocket();
const handleConnErr = function (err) {
err.message = "Can't open data connection in passive mode: " + err.message;
reject(err);
};
const handleTimeout = function () {
socket.destroy();
reject(new Error(`Timeout when trying to open data connection to ${host}:${port}`));
};
socket.setTimeout(ftp.timeout);
socket.on("error", handleConnErr);
socket.on("timeout", handleTimeout);
socket.connect({ port, host, family: ftp.ipFamily }, () => {
if (ftp.socket instanceof tls_1.TLSSocket) {
socket = (0, tls_1.connect)(Object.assign({}, ftp.tlsOptions, {
socket,
// Reuse the TLS session negotiated earlier when the control connection
// was upgraded. Servers expect this because it provides additional
// security: If a completely new session would be negotiated, a hacker
// could guess the port and connect to the new data connection before we do
// by just starting his/her own TLS session.
session: ftp.socket.getSession()
}));
// It's the responsibility of the transfer task to wait until the
// TLS socket issued the event 'secureConnect'. We can't do this
// here because some servers will start upgrading after the
// specific transfer request has been made. List and download don't
// have to wait for this event because the server sends whenever it
// is ready. But for upload this has to be taken into account,
// see the details in the upload() function below.
}
// Let the FTPContext listen to errors from now on, remove local handler.
socket.removeListener("error", handleConnErr);
socket.removeListener("timeout", handleTimeout);
ftp.dataSocket = socket;
resolve();
});
});
}
exports.connectForPassiveTransfer = connectForPassiveTransfer;
/**
* Helps resolving/rejecting transfers.
*
* This is used internally for all FTP transfers. For example when downloading, the server might confirm
* with "226 Transfer complete" when in fact the download on the data connection has not finished
* yet. With all transfers we make sure that a) the result arrived and b) has been confirmed by
* e.g. the control connection. We just don't know in which order this will happen.
*/
class TransferResolver {
/**
* Instantiate a TransferResolver
*/
constructor(ftp, progress) {
this.ftp = ftp;
this.progress = progress;
this.response = undefined;
this.dataTransferDone = false;
}
/**
* Mark the beginning of a transfer.
*
* @param name - Name of the transfer, usually the filename.
* @param type - Type of transfer, usually "upload" or "download".
*/
onDataStart(name, type) {
// Let the data socket be in charge of tracking timeouts during transfer.
// The control socket sits idle during this time anyway and might provoke
// a timeout unnecessarily. The control connection will take care
// of timeouts again once data transfer is complete or failed.
if (this.ftp.dataSocket === undefined) {
throw new Error("Data transfer should start but there is no data connection.");
}
this.ftp.socket.setTimeout(0);
this.ftp.dataSocket.setTimeout(this.ftp.timeout);
this.progress.start(this.ftp.dataSocket, name, type);
}
/**
* The data connection has finished the transfer.
*/
onDataDone(task) {
this.progress.updateAndStop();
// Hand-over timeout tracking back to the control connection. It's possible that
// we don't receive the response over the control connection that the transfer is
// done. In this case, we want to correctly associate the resulting timeout with
// the control connection.
this.ftp.socket.setTimeout(this.ftp.timeout);
if (this.ftp.dataSocket) {
this.ftp.dataSocket.setTimeout(0);
}
this.dataTransferDone = true;
this.tryResolve(task);
}
/**
* The control connection reports the transfer as finished.
*/
onControlDone(task, response) {
this.response = response;
this.tryResolve(task);
}
/**
* An error has been reported and the task should be rejected.
*/
onError(task, err) {
this.progress.updateAndStop();
this.ftp.socket.setTimeout(this.ftp.timeout);
this.ftp.dataSocket = undefined;
task.reject(err);
}
/**
* Control connection sent an unexpected request requiring a response from our part. We
* can't provide that (because unknown) and have to close the contrext with an error because
* the FTP server is now caught up in a state we can't resolve.
*/
onUnexpectedRequest(response) {
const err = new Error(`Unexpected FTP response is requesting an answer: ${response.message}`);
this.ftp.closeWithError(err);
}
tryResolve(task) {
// To resolve, we need both control and data connection to report that the transfer is done.
const canResolve = this.dataTransferDone && this.response !== undefined;
if (canResolve) {
this.ftp.dataSocket = undefined;
task.resolve(this.response);
}
}
}
function uploadFrom(source, config) {
const resolver = new TransferResolver(config.ftp, config.tracker);
const fullCommand = `${config.command} ${config.remotePath}`;
return config.ftp.handle(fullCommand, (res, task) => {
if (res instanceof Error) {
resolver.onError(task, res);
}
else if (res.code === 150 || res.code === 125) { // Ready to upload
const dataSocket = config.ftp.dataSocket;
if (!dataSocket) {
resolver.onError(task, new Error("Upload should begin but no data connection is available."));
return;
}
// If we are using TLS, we have to wait until the dataSocket issued
// 'secureConnect'. If this hasn't happened yet, getCipher() returns undefined.
const canUpload = "getCipher" in dataSocket ? dataSocket.getCipher() !== undefined : true;
onConditionOrEvent(canUpload, dataSocket, "secureConnect", () => {
config.ftp.log(`Uploading to ${(0, netUtils_1.describeAddress)(dataSocket)} (${(0, netUtils_1.describeTLS)(dataSocket)})`);
resolver.onDataStart(config.remotePath, config.type);
(0, stream_1.pipeline)(source, dataSocket, err => {
if (err) {
resolver.onError(task, err);
}
else {
resolver.onDataDone(task);
}
});
});
}
else if ((0, parseControlResponse_1.positiveCompletion)(res.code)) { // Transfer complete
resolver.onControlDone(task, res);
}
else if ((0, parseControlResponse_1.positiveIntermediate)(res.code)) {
resolver.onUnexpectedRequest(res);
}
// Ignore all other positive preliminary response codes (< 200)
});
}
exports.uploadFrom = uploadFrom;
function downloadTo(destination, config) {
if (!config.ftp.dataSocket) {
throw new Error("Download will be initiated but no data connection is available.");
}
const resolver = new TransferResolver(config.ftp, config.tracker);
return config.ftp.handle(config.command, (res, task) => {
if (res instanceof Error) {
resolver.onError(task, res);
}
else if (res.code === 150 || res.code === 125) { // Ready to download
const dataSocket = config.ftp.dataSocket;
if (!dataSocket) {
resolver.onError(task, new Error("Download should begin but no data connection is available."));
return;
}
config.ftp.log(`Downloading from ${(0, netUtils_1.describeAddress)(dataSocket)} (${(0, netUtils_1.describeTLS)(dataSocket)})`);
resolver.onDataStart(config.remotePath, config.type);
(0, stream_1.pipeline)(dataSocket, destination, err => {
if (err) {
resolver.onError(task, err);
}
else {
resolver.onDataDone(task);
}
});
}
else if (res.code === 350) { // Restarting at startAt.
config.ftp.send("RETR " + config.remotePath);
}
else if ((0, parseControlResponse_1.positiveCompletion)(res.code)) { // Transfer complete
resolver.onControlDone(task, res);
}
else if ((0, parseControlResponse_1.positiveIntermediate)(res.code)) {
resolver.onUnexpectedRequest(res);
}
// Ignore all other positive preliminary response codes (< 200)
});
}
exports.downloadTo = downloadTo;
/**
* Calls a function immediately if a condition is met or subscribes to an event and calls
* it once the event is emitted.
*
* @param condition The condition to test.
* @param emitter The emitter to use if the condition is not met.
* @param eventName The event to subscribe to if the condition is not met.
* @param action The function to call.
*/
function onConditionOrEvent(condition, emitter, eventName, action) {
if (condition === true) {
action();
}
else {
emitter.once(eventName, () => action());
}
}
