rlgwebd/webttyd.js
2012-05-06 08:45:40 -07:00

531 lines
14 KiB
JavaScript
Executable file

#!/usr/bin/env node
// If you can't quite trust node to find it on its own
var localModules = '/usr/local/lib/node_modules/';
var http = require('http');
var url = require('url');
var path = require('path');
var fs = require('fs');
//var tty = require("tty");
var child_process = require('child_process');
var daemon = require(path.join(localModules, "daemon"));
var chrootDir = "/var/dgl/";
var dropToUID = 501;
var dropToGID = 501;
var serveStaticRoot = "/var/www/"; // inside the chroot
var passwdfile = "/dgldir/dgl-login";
var sessions = {};
var games = {
"rogue3": {
"name": "Rogue V3",
"uname": "rogue3",
"path": "/bin/rogue3"
},
"rogue4": {
"name": "Rogue V4",
"uname": "rogue4",
"path": "/bin/rogue4"
},
"rogue5": {
"name": "Rogue V5",
"uname": "rogue5",
"path": "/bin/rogue5"
},
"srogue": {
"name": "Super-Rogue",
"uname": "srogue",
"path": "/bin/srogue"
}
};
/* Constructor for TermSessions. Note that it opens the terminal and
* adds itself to the sessions dict. It currently assumes the user has
* been authenticated.
*/
function TermSession(game, user, files) {
/* First make sure starting the game will work. */
if (!(game in games)) {
// TODO: throw an exception instead
return null;
}
/* This order seems to best avoid race conditions... */
this.alive = false;
this.sessid = randkey();
while (this.sessid in sessions) {
this.sessid = randkey();
}
/* Grab a spot in the sessions table. */
sessions[this.sessid] = this;
/* TODO handle tty-opening errors */
//var pterm = tty.open(games[game].path, ["-n", user.toString()]);
/* TODO make argument-finding into a method */
args = [games[game].path, "-n", user.toString()];
this.child = child_process.spawn("/bin/ptyhelper", args);
var ss = this;
//this.ptmx = pterm[0];
//this.child = pterm[1];
this.alive = true;
this.data = [];
this.lock = files[0];
fs.writeFile(this.lock, this.child.pid.toString() + '\n80\n24\n', "utf8");
this.record = fs.createWriteStream(files[1], { mode: 0664 });
/* END setup */
function ttyrec_chunk(buf) {
var ts = new Date();
var chunk = new Buffer(buf.length + 12);
/* TTYREC headers */
chunk.writeUInt32LE(Math.floor(ts.getTime() / 1000), 0);
chunk.writeUInt32LE(1000 * (ts.getTime() % 1000), 4);
chunk.writeUInt32LE(buf.length, 8);
buf.copy(chunk, 12);
ss.data.push(chunk);
ss.record.write(chunk);
}
this.child.stdout.on("data", ttyrec_chunk);
this.child.stderr.on("data", ttyrec_chunk);
this.child.on("exit", function (code, signal) {
ss.exitcode = (code != null ? code : 255);
ss.alive = false;
fs.unlink(ss.lock);
/* Wait for all the data to get collected */
setTimeout(ss.cleanup, 1000);
});
this.write = function (data) {
if (this.alive)
this.child.stdin.write(data);
/* Otherwise, throw some kind of exception? */
};
this.read = function () {
if (this.data.length == 0)
return null;
var pos = 0;
var i = 0;
for (i = 0; i < this.data.length; i++)
pos += this.data[i].length - 12;
var nbuf = new Buffer(pos);
var tptr;
pos = 0;
while (this.data.length > 0) {
tptr = this.data.shift();
tptr.copy(nbuf, pos, 12);
pos += tptr.length - 12;
}
return nbuf;
};
this.close = function () {
if (this.alive)
this.child.kill('SIGHUP');
};
this.cleanup = function () {
/* Call this when the child is dead. */
if (this.alive)
return;
//ss.ptmx.destroy();
ss.record.end();
/* Give the client a chance to read any leftover data. */
if (ss.data.length > 0)
setTimeout(ss.remove, 8000);
else
ss.remove();
};
this.remove = function () {
delete sessions[ss.sessid];
console.log("Session " + this.sessid + " removed.");
};
}
/* A few utility functions */
function timestamp() {
dd = new Date();
sd = dd.toISOString();
sd = sd.slice(0, sd.indexOf("."));
return sd.replace("T", ".");
}
function randkey() {
rnum = Math.floor(Math.random() * 65536 * 65536);
hexstr = rnum.toString(16);
while (hexstr.length < 8)
hexstr = "0" + hexstr;
return hexstr;
}
/* Returns a list of the cookies in the request, obviously. */
function getCookies(req) {
cookies = [];
if ("cookie" in req.headers) {
cookstrs = req.headers["cookie"].split("; ");
for (var i = 0; i < cookstrs.length; i++) {
eqsign = cookstrs[i].indexOf("=");
if (eqsign > 0) {
name = cookstrs[i].slice(0, eqsign).toLowerCase();
val = cookstrs[i].slice(eqsign + 1);
cookies[name] = val;
}
else if (eqsign < 0)
cookies[cookstrs[i]] = null;
}
}
return cookies;
}
function urlDec(encstr) {
var decstr = "";
var tnum;
for (var i = 0; i < encstr.length; i++)
{
if (encstr.charAt(i) == "+")
decstr += " ";
else if (encstr.charAt(i) == "%")
{
tnum = Number("0x" + encstr.slice(i + 1, 2));
if (!isNaN(tnum) && tnum >= 0)
decstr += String.fromCharCode(tnum);
i += 2;
}
else
decstr += encstr.charAt(i);
}
return decstr;
}
/* Returns the contents of a form */
function getFormValues(formtext) {
var pairstrs = formtext.split("&");
var data = {};
for (var i = 0; i < pairstrs.length; i++)
{
var eqsign = pairstrs[i].indexOf("=");
if (eqsign > 0) {
rawname = pairstrs[i].slice(0, eqsign);
rawval = pairstrs[i].slice(eqsign + 1);
name = urlDec(rawname);
val = urlDec(rawval);
if (!(name in data))
data[name] = [];
data[name].push(val);
}
}
return data;
}
function auth(username, password) {
// Real authentication not implemented
return true;
}
function login(req, res, formdata) {
if (!("game" in formdata)) {
sendError(res, 2, "No game specified.");
return;
}
else if (!("name" in formdata)) {
sendError(res, 2, "Username not given.");
return;
}
else if (!("pw" in formdata)) {
sendError(res, 2, "Password not given.");
return;
}
var username = formdata["name"][0];
var password = formdata["pw"][0];
var gname = formdata["game"][0];
if (!(gname in games)) {
sendError(res, 2, "No such game: " + gname);
console.log("Request for nonexistant game \"" + gname + "\"");
return;
}
var progressdir = "/dgldir/inprogress-" + games[gname].uname;
// This sets up the game once starting is approved.
function startgame() {
var ts = timestamp();
var lockfile = path.join(progressdir, username + ":node:" + ts + ".ttyrec");
var ttyrec = path.join("/dgldir/ttyrec", username, gname, ts + ".ttyrec");
var nsession = new TermSession(gname, username, [lockfile, ttyrec]);
if (nsession) {
/* Technically there's a race condition for the "lock"file, but since
* it requires the user deliberately starting two games at similar times,
* it's not too serious. We can't get O_EXCL in Node anyway. */
res.writeHead(200, {'Content-Type': 'text/plain'});
res.write("l1\n" + nsession.sessid + "\n");
res.end();
console.log("%s playing %s (key %s, pid %d)", username, gname,
nsession.sessid, nsession.child.pid);
}
else {
sendError(res, 5, "Failed to open TTY");
console.log("Unable to allocate TTY for " + gname);
}
}
function checkit(code, signal) {
// check the password
if (code != 0) {
sendError(res, 3);
console.log("Password check failed for user " + username);
return;
}
// check for an existing game
fs.readdir(progressdir, function(err, files) {
if (!err) {
var fre = RegExp("^" + username + ":");
for (var i = 0; i < files.length; i++) {
if (files[i].match(fre)) {
sendError(res, 4, null);
return;
}
}
}
// If progressdir isn't readable, start a new game anyway.
startgame();
});
}
/* Look for the user in the password file */
fs.readFile(passwdfile, "utf8", function(err, data) {
if (err) {
sendError(res, 3);
console.log("Can't authenticate: " + err.toString());
return;
}
var dlines = data.split('\n');
for (var n = 0; n < dlines.length; n++) {
var fields = dlines[n].split(':');
if (fields[0] == username) {
// check the password with the quickrypt utility
checker = require('child_process').spawn("/bin/quickrypt")
checker.on("exit", checkit);
checker.stdin.end(password + '\n' + fields[2] + '\n', "utf8");
return;
}
}
sendError(res, 3);
console.log("Attempted login by nonexistent user " + username);
});
return;
}
function logout(term, res) {
if (!term.alive) {
sendError(res, 1, null);
return;
}
cterm.close();
var resheaders = {'Content-Type': 'text/plain'};
res.writeHead(200, resheaders);
res.write("q1\n\n");
res.end();
return;
}
function findTermSession(formdata) {
if ("id" in formdata) {
var sessid = formdata["id"][0];
if (sessid in sessions) {
return sessions[sessid];
}
}
return null;
}
function serveStatic(req, res, fname) {
var nname = path.normalize(fname);
if (nname == "" || nname == "/")
nname = "index.html";
if (nname.match(/\/$/))
path.join(nname, "index.html"); /* it was a directory */
var realname = path.join(serveStaticRoot, nname);
var extension = path.extname(realname);
path.exists(realname, function (exists) {
var resheaders = {};
if (!exists || !extension || extension == ".html")
resheaders["Content-Type"] = "text/html";
else if (extension == ".png")
resheaders["Content-Type"] = "image/png";
else if (extension == ".css")
resheaders["Content-Type"] = "text/css";
else if (extension == ".js")
resheaders["Content-Type"] = "text/javascript";
else if (extension == ".svg")
resheaders["Content-Type"] = "image/svg+xml";
else
resheaders["Content-Type"] = "application/octet-stream";
if (exists) {
fs.readFile(realname, function (error, data) {
if (error) {
res.writeHead(500, {});
res.end();
}
else {
res.writeHead(200, resheaders);
res.write(data);
res.end();
}
});
}
else {
res.writeHead(404, resheaders);
res.write("<html><head><title>" + nname + "</title></head>\n<body><h1>" + nname + " Not Found</h1></body></html>\n");
res.end();
}
});
return;
}
function readFeed(res, term) {
if (term) {
var result = term.read();
res.writeHead(200, { "Content-Type": "text/plain" });
if (result == null)
resultstr = "";
else
resultstr = result.toString("hex");
if (result == null && !term.alive) {
/* Child has terminated and data is flushed. */
res.write("q1\n\n");
}
else
res.write("d" + resultstr.length.toString() + "\n" + resultstr + "\n");
res.end();
}
else {
//console.log("Where's the term?");
sendError(res, 1, null);
}
}
var errorcodes = [ "Generic Error", "Not logged in", "Invalid data",
"Login failed", "Already playing", "Game launch failed" ];
function sendError(res, ecode, msg) {
res.writeHead(200, { "Content-Type": "text/plain" });
if (ecode < errorcodes.length && ecode > 0) {
var emsg = errorcodes[ecode];
if (msg)
emsg += ": " + msg;
res.write("E" + ecode + '\n' + emsg + '\n');
}
else
res.write("E0\nGeneric Error\n");
res.end();
}
function handler(req, res) {
/* default headers for the response */
var resheaders = {'Content-Type': 'text/html'};
/* The request body will be added to this as it arrives. */
var reqbody = "";
var formdata;
/* Register a listener to get the body. */
function moredata(chunk) {
reqbody += chunk;
}
req.on('data', moredata);
/* This will send the response once the whole request is here. */
function respond() {
formdata = getFormValues(reqbody);
var target = url.parse(req.url).pathname;
var cterm = findTermSession(formdata);
/* First figure out if the client is POSTing to a command interface. */
if (req.method == 'POST') {
if (target == '/feed') {
if (!cterm) {
sendError(res, 1, null);
return;
}
if ("quit" in formdata) {
/* The client wants to terminate the process. */
logout(cterm, res);
}
else if (formdata["keys"]) {
/* process the keys */
hexstr = formdata["keys"][0].replace(/[^0-9a-f]/gi, "");
if (hexstr.length % 2 != 0) {
sendError(res, 2, "incomplete byte");
return;
}
keybuf = new Buffer(hexstr, "hex");
cterm.write(keybuf);
}
readFeed(res, cterm);
}
else if (target == "/login") {
login(req, res, formdata);
}
else {
res.writeHead(405, resheaders);
res.end();
}
}
else if (req.method == 'GET' || req.method == 'HEAD') {
if (target == '/feed') {
if (!cterm) {
sendError(res, 1, null);
return;
}
readFeed(res, cterm);
}
/* Default page, create a new term */
/* FIXME New term not created anymore, is a special case still needed? */
else if (target == '/') {
serveStatic(req, res, "/");
}
else /* Go look for it in the filesystem */
serveStatic(req, res, target);
}
else { /* Some other method */
res.writeHead(501, resheaders);
res.write("<html><head><title>501</title></head>\n<body><h1>501 Not Implemented</h1></body></html>\n");
res.end();
}
return;
}
req.on('end', respond);
}
process.on("exit", function () {
for (var sessid in sessions) {
if (sessions[sessid].alive)
sessions[sessid].child.kill('SIGHUP');
}
console.log("Quitting...");
return;
});
/* Initialization STARTS HERE */
process.env["TERM"] = "xterm-256color";
if (process.getuid() != 0) {
console.log("Not running as root, cannot chroot.");
process.exit(1);
}
try {
process.chdir(chrootDir);
}
catch (err) {
console.log("Cannot enter " + chrootDir + " : " + err);
process.exit(1);
}
try {
daemon.chroot(chrootDir);
}
catch (err) {
console.log("chroot to " + chrootDir + " failed: " + err);
process.exit(1);
}
try {
// drop gid first, that requires UID=0
process.setgid(dropToGID);
process.setuid(dropToUID);
}
catch (err) {
console.log("Could not drop permissions: " + err);
process.exit(1);
}
http.createServer(handler).listen(8080, "127.0.0.1");
console.log('webttyd running at http://127.0.0.1:8080/');