nntp-server-zefie
Version:
NNTP server implementation, modified for zefie_wtvp_minisrv
251 lines (199 loc) • 6.76 kB
JavaScript
// Client session. Contains all info about current connection state.
//
'use strict';
const crypto = require('crypto');
const Denque = require('denque');
const debug_err = require('debug')('nntp-server.error');
const debug_net = require('debug')('nntp-server.network');
const serializeError = require('serialize-error').serializeError;
const split2 = require('split2');
const pipeline = require('stream').pipeline;
const flattenStream = require('./flatten-stream');
const status = require('./status');
const CMD_WAIT = 0;
const CMD_PENDING = 1;
const CMD_RESOLVED = 2;
const CMD_REJECTED = 3;
// same as lodash.escapeRegExp
function escape_regexp(str) {
return str.replace(/[\\^$.*+?()[\]{}|]/g, '\\$&');
}
function Command(fn, cmd_line) {
this.state = CMD_WAIT;
this.fn = fn;
this.cmd_line = cmd_line;
this.resolved_value = null;
this.rejected_value = null;
}
Command.prototype.run = function () {
this.state = CMD_PENDING;
return this.fn().then(
value => {
this.state = CMD_RESOLVED;
this.resolved_value = value;
},
value => {
this.state = CMD_REJECTED;
this.rejected_value = value;
}
);
};
function Session(server, stream) {
this.in_stream = stream;
this.out_stream = flattenStream();
this.server = server;
// Could be just {}, but this is more clean
// if this.groups.name is not set, group is not selected
this.group = {
min_index: 0,
max_index: 0,
total: 0,
name: null,
description: '',
current_article: 0
};
this.pipeline = new Denque();
this.debug_mark = crypto.pseudoRandomBytes(3).toString('hex');
// Random string used to track connection in logs
debug_net(' [%s] %s', this.debug_mark, 'new connection');
// Create RE to search command name. Longest first (for subcommands)
let commands = Object.keys(this.server.commands).sort().reverse();
this.__search_cmd_re = RegExp(`^(${commands.map(escape_regexp).join('|')})`, 'i');
this.lines = split2();
this.write((server.options.allow_posting) ? status._200_SRV_READY_RW : status._201_SRV_READY_RO);
pipeline(stream, this.lines, () => {});
pipeline(this.out_stream, stream, () => {});
if (debug_net.enabled) {
let debug_logger = split2();
pipeline(this.out_stream, debug_logger, () => {});
debug_logger.on('data', line => {
debug_net('<-- [%s] %s', this.debug_mark, line);
});
}
this.lines.on('data', line => {
debug_net('--> [%s] %s', this.debug_mark, line);
this.parse(line);
});
this.lines.on('error', err => {
debug_err('ERROR: %O', serializeError(err));
this.server._onError(err);
this.out_stream.destroy();
});
this.lines.on('end', () => {
debug_net(' [%s] %s', this.debug_mark, 'connection closed');
this.out_stream.destroy();
});
}
// By default connection is not secure
Session.prototype.secure = false;
// Default mode is "reader"
Session.prototype.reader = true;
Session.prototype.authenticated = false;
Session.prototype.authinfo_user = null;
Session.prototype.authinfo_pass = null;
Session.prototype.current_group = null;
/**
* Send strings to connected client, adding CRLF after each
*
* data:
*
* - String
* - Stream of strings (object mode)
* - null (close session)
* - Array with any combinations above
*/
Session.prototype.write = function (data) {
if (!this.out_stream.writable) {
if (typeof data.destroy === 'function') data.destroy();
return;
}
this.out_stream.write(data);
};
function enqueue(session, command) {
session.pipeline.push(command);
session.tick();
}
// Parse client commands and push into pipeline
//
Session.prototype.parse = function (data) {
let input = data.toString().replace(/\r?\n$/, '');
if (input == "POST") {
if (this.posting_allowed) {
this.is_posting = true // handle post seperately
enqueue(this, new Command(() => Promise.resolve(status._340_SEND_ARTICLE), null))
return;
} else {
enqueue(this, new Command(() => Promise.resolve(status._440_NO_POST_PERM), null))
return;
}
}
if (!this.is_posting) {
// Command not recognized
if (!this.__search_cmd_re.test(input)) {
enqueue(this, new Command(() => Promise.resolve(status._500_CMD_UNKNOWN), input));
return;
}
let cmd = input.match(this.__search_cmd_re)[1].toUpperCase();
// Command looks known, but whole validation failed -> bad params
if (!this.server.commands[cmd].validate.test(input)) {
enqueue(this, new Command(() => Promise.resolve(status._501_SYNTAX_ERROR), input));
return;
}
// Command require auth, but it was not done yet
// Force secure connection if needed
if (this.server._needAuth(this, cmd)) {
enqueue(this, new Command(() => Promise.resolve(
this.secure ? status._480_AUTH_REQUIRED : status._483_NOT_SECURE
), input));
return;
}
enqueue(this, new Command(() => Promise.resolve(this.server.commands[cmd].run(this, input)), input));
} else {
if (!this.post_data) this.post_data = {};
if (data.toString().replace(/\r?\n$/, '') == '' && !this.recv_post_body) {
this.recv_post_body = true;
return;
}
if (input === ".") {
delete this.is_posting;
delete this.recv_post_body;
if (this.server._postArticle(this)) enqueue(this, new Command(() => Promise.resolve(status._240_ARTICLE_RECV_OK), null))
else enqueue(this, new Command(() => Promise.resolve(status._441_POSTING_FAILED), null))
delete this.post_data;
return;
}
if (!this.recv_post_body) {
// headers
if (!this.post_data.headers) this.post_data.headers = {}
var header = data.toString().split(/\: (.*)/s)
this.post_data.headers[header[0]] = header[1];
} else {
if (!this.post_data.body) this.post_data.body = [];
this.post_data.body.push((data) ? data.toString() : '');
}
}
};
Session.prototype.tick = function () {
if (this.pipeline.isEmpty()) return;
let cmd = this.pipeline.peekFront();
if (cmd.state === CMD_RESOLVED) {
this.write(cmd.resolved_value);
this.pipeline.shift();
this.tick();
} else if (cmd.state === CMD_REJECTED) {
if (cmd.rejected_value) cmd.rejected_value.nntp_command = cmd.cmd_line;
this.write(status._403_FUCKUP);
debug_err('ERROR: %O', serializeError(cmd.rejected_value));
this.server._onError(cmd.rejected_value);
this.pipeline.shift();
this.tick();
} else if (cmd.state === CMD_WAIT) {
// stop executing commands on closed connection
if (!this.out_stream.writable) return;
cmd.run().then(() => this.tick());
}
};
module.exports = Session;
module.exports.create = function (server, stream) {
return new Session(server, stream);
};