Files
duplicati/Tools/CGIProxyHandler/Program.cs
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428 lines
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C#
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2016-05-13 00:06:12 +02:00
using System;
using System.Diagnostics;
using System.Threading.Tasks;
using System.Text.RegularExpressions;
using System.Linq;
using System.IO;
using System.Collections.Generic;
using System.Threading;
using System.Runtime.InteropServices;
namespace CGIProxyHandler
{
class MainClass
{
private class LogHandler
{
private object m_lock = new object();
private StreamWriter m_stream;
private bool m_debug;
public LogHandler(StreamWriter writer, bool debug)
{
m_stream = writer;
m_debug = debug;
}
public void WriteMessage(string msg)
{
if (m_stream != null)
lock(m_lock)
m_stream.WriteLine(msg);
}
public void WriteDebugMessage(string msg)
{
if (m_stream != null && m_debug)
lock(m_lock)
m_stream.WriteLine(msg);
}
}
/// <summary>
/// Runs an external command
/// </summary>
/// <returns>The stdout data.</returns>
/// <param name="command">The executable</param>
/// <param name="args">The executable and the arguments.</param>
/// <param name="shell">If set to <c>true</c> use the shell context for execution.</param>
/// <param name="exitcode">Set the value to check for a particular exitcode.</param>
private static async Task<string> ShellExec(string command, string args = null, bool shell = false, int exitcode = -1, Dictionary<string, string> env = null)
{
var psi = new ProcessStartInfo() {
FileName = command,
Arguments = shell ? null : args,
UseShellExecute = false,
RedirectStandardInput = shell,
RedirectStandardOutput = true
};
if (env != null)
foreach (var pk in env)
psi.EnvironmentVariables[pk.Key] = pk.Value;
using (var p = Process.Start(psi))
{
if (shell && args != null)
await p.StandardInput.WriteLineAsync(args);
var res = await p.StandardOutput.ReadToEndAsync();
p.WaitForExit((int)TimeSpan.FromSeconds(5).TotalMilliseconds);
if (p.ExitCode != exitcode && exitcode != -1)
throw new Exception(string.Format("Exit code was: {0}, stdout: {1}", p.ExitCode, res));
return res;
}
}
private static string GetEnvArg(string key, string @default = null)
{
var res = Environment.GetEnvironmentVariable(key);
return string.IsNullOrWhiteSpace(res) ? @default : res.Trim();
}
private const string CRLF = "\r\n";
private static readonly byte[] ERROR_MESSAGE = System.Text.Encoding.ASCII.GetBytes("Status: 500 Server error" + CRLF + CRLF);
public static void Main(string[] args)
{
var debug = GetEnvArg("PROXY_DEBUG", "0") == "1";
var logfile = GetEnvArg("PROXY_LOGFILE", "/var/log/duplicat-proxy.log");
using (var logout = new StreamWriter(File.Open(logfile, System.IO.FileMode.Append, FileAccess.Write, FileShare.ReadWrite)))
using(var stdout = Console.OpenStandardOutput())
{
if (logout != null)
logout.AutoFlush = true;
var logger = new LogHandler(logout, debug);
try
{
//stdout.WriteTimeout = (int)ACTIVITY_TIMEOUT.TotalMilliseconds;
logger.WriteDebugMessage("Started!");
logger.WriteDebugMessage(string.Format("Processing request for target url: {0}", GetEnvArg("HTTP_X_PROXY_PATH")));
logger.WriteDebugMessage(string.Format("Redirects: {0},{1},{2}", Console.IsInputRedirected, Console.IsOutputRedirected, Console.IsErrorRedirected));
if (args == null)
args = new string[0];
foreach(var a in args)
logger.WriteDebugMessage(string.Format("arg: {0}", a));
Run(args, logger, stdout).Wait();
}
catch (Exception ex)
{
var rex = ex;
if (rex is AggregateException && (rex as AggregateException).Flatten().InnerExceptions.Count == 1)
rex = (rex as AggregateException).Flatten().InnerExceptions.First();
if (debug)
logger.WriteMessage(string.Format("Failed: {0}", rex));
else
logger.WriteMessage(string.Format("Failed: {0}", rex.Message));
try
{
stdout.Write(ERROR_MESSAGE, 0, ERROR_MESSAGE.Length);
}
catch (Exception ex2)
{
logger.WriteDebugMessage(string.Format("Failed to set error status: {0}", ex2));
}
}
}
}
private static async Task Run(string[] args, LogHandler logger, Stream stdout)
{
var login_cgi = GetEnvArg("SYNO_LOGIN_CGI", "/usr/syno/synoman/webman/login.cgi");
var auth_cgi = GetEnvArg("SYNO_AUTHENTICATE_CGI", "/usr/syno/synoman/webman/modules/authenticate.cgi");
var admin_only = !(GetEnvArg("SYNO_ALL_USERS", "0") == "1");
var auto_xsrf = GetEnvArg("SYNO_AUTO_XSRF", "1") == "1";
var skip_auth = GetEnvArg("SYNO_SKIP_AUTH", "0") == "1";
var query_string = GetEnvArg("QUERY_STRING", "");
var proxy_host = GetEnvArg("PROXY_HOST", "localhost");
var proxy_port = GetEnvArg("PROXY_PORT", "8200");
var xsrftoken = GetEnvArg("HTTP_X_SYNO_TOKEN");
if (string.IsNullOrWhiteSpace(xsrftoken) && !string.IsNullOrWhiteSpace(query_string))
{
// Avoid loading a library just for parsing the token
var tkre = new Regex(@"SynoToken=(<?token>[^&+])");
var m = tkre.Match(query_string);
if (m.Success)
xsrftoken = m.Groups["token"].Value;
}
if (!skip_auth)
{
if (string.IsNullOrWhiteSpace(xsrftoken) && auto_xsrf)
{
var authre = new Regex(@"""SynoToken""\s?\:\s?""(?<token>[^""]+)""");
var resp = await ShellExec(login_cgi);
logger.WriteDebugMessage(string.Format("xsrf response is: {0}", resp));
var m = authre.Match(resp);
if (m.Success)
xsrftoken = m.Groups["token"].Value;
else
throw new Exception("Unable to get XSRF token");
}
var tmpenv = new Dictionary<string, string>();
tmpenv["QUERY_STRING"] = "SynoToken=" + xsrftoken;
var username = GetEnvArg("SYNO_USERNAME");
if (string.IsNullOrWhiteSpace(username))
{
username = await ShellExec(auth_cgi, shell: false, exitcode: 0, env: tmpenv);
logger.WriteDebugMessage(string.Format("Username: {0}", username));
}
if (string.IsNullOrWhiteSpace(username))
throw new Exception("Not logged in");
username = username.Trim();
if (admin_only)
{
var groups = GetEnvArg("SYNO_GROUP_IDS");
if (string.IsNullOrWhiteSpace(groups))
groups = await ShellExec("id", "-G '" + username.Trim().Replace("'", "\\'") + "'", exitcode: 0) ?? "";
if (!groups.Split(new char[] { ' ' }).Contains("101"))
throw new Exception(string.Format("User {0} is not an admin", username));
logger.WriteDebugMessage("User is admin");
}
}
var path = GetEnvArg("HTTP_X_PROXY_PATH");
if (string.IsNullOrWhiteSpace(path))
{
var xpre = new Regex(@"x-proxy-path=(<?url>[^&+])");
var m = xpre.Match(query_string);
if (m.Success)
path = Uri.UnescapeDataString(m.Groups["url"].Value);
}
logger.WriteDebugMessage(string.Format("Path is {0} and query string is {1}", path, query_string));
if (string.IsNullOrWhiteSpace(path) || !path.StartsWith("/"))
throw new Exception("Invalid path requested");
if (!string.IsNullOrWhiteSpace(query_string))
path += (query_string.StartsWith("?") ? "" : "?") + Uri.EscapeUriString(query_string);
int port;
if (!int.TryParse(proxy_port, out port))
port = 8200;
logger.WriteDebugMessage(string.Format("About to connect to {0}:{1}", proxy_host, port));
using (var client = new System.Net.Sockets.TcpClient())
{
logger.WriteDebugMessage(string.Format("Connecting to {0}:{1}", proxy_host, port));
client.Connect(proxy_host, port);
logger.WriteDebugMessage("Connected");
using (var ns = client.GetStream())
{
logger.WriteDebugMessage("Opened TCP stream");
using (var sw = new StreamWriter(ns))
{
logger.WriteDebugMessage("Created StreamWriter");
//await ForwardRequest(sw, path, logout);
//await ForwardResponse(ns, stdout, logout);
await Task.WhenAll(
ForwardRequest(sw, path, logger),
ForwardResponse(ns, stdout, logger)
);
logger.WriteDebugMessage("Done processing");
}
}
}
}
private static readonly byte[] STATUS_PREFIX = System.Text.Encoding.ASCII.GetBytes("Status: ");
private static readonly int HTTP_HEAD_LEN = "HTTP/1.1 ".Length;
private static async Task ForwardResponse(Stream source, Stream target, LogHandler logger)
{
var buf = new byte[8 * 1024];
int r = 0;
int offset = 0;
var lastmatch = 0;
var status = false;
long contentlength = -1;
var canceltoken = new CancellationTokenSource();
logger.WriteDebugMessage("Forward response");
while ((r = await source.ReadAsync(buf, offset, buf.Length - offset, canceltoken.Token)) != 0)
{
logger.WriteDebugMessage(string.Format("Read {0} bytes", r));
offset += r;
var ix = Array.IndexOf(buf, (byte)13, 0, offset);
while (ix >= 0 && ix < offset - 1)
{
if (buf[ix + 1] == 10)
{
if (!status)
{
status = true;
logger.WriteDebugMessage("Writing: Status: " + System.Text.Encoding.ASCII.GetString(buf, lastmatch + HTTP_HEAD_LEN, ix - lastmatch - HTTP_HEAD_LEN));
await target.WriteAsync(STATUS_PREFIX, 0, STATUS_PREFIX.Length, canceltoken.Token);
await target.WriteAsync(buf, lastmatch + HTTP_HEAD_LEN, (ix - lastmatch - HTTP_HEAD_LEN) + 2, canceltoken.Token);
logger.WriteDebugMessage("Wrote status line");
}
else
{
// Blank line and we are done
if (ix - lastmatch == 0)
{
logger.WriteDebugMessage(string.Format("Completed header, writing remaining {0} bytes", offset - lastmatch));
await target.WriteAsync(buf, lastmatch, offset - lastmatch, canceltoken.Token);
// Adjust remaining data length
if (contentlength > 0)
contentlength -= offset - lastmatch - 2;
logger.WriteDebugMessage(string.Format("Body has remaining {0} bytes", contentlength));
while(contentlength > 0)
{
r = await source.ReadAsync(buf, 0, (int)Math.Min(buf.Length, contentlength), canceltoken.Token);
if (r == 0)
break;
contentlength -= r;
await target.WriteAsync(buf, 0, r, canceltoken.Token);
logger.WriteDebugMessage(string.Format("Body has remaining {0} bytes", contentlength));
}
await target.FlushAsync(canceltoken.Token);
//await logout.WriteDebugMessageAsync(string.Format("Last body chunck: {0}", System.Text.Encoding.ASCII.GetString(buf, 0, r)));
logger.WriteDebugMessage(string.Format("Completed response forward"));
target.Close();
return;
}
else
{
var header = System.Text.Encoding.ASCII.GetString(buf, lastmatch, ix - lastmatch) ?? string.Empty;
if (header.StartsWith("Content-Length: ", StringComparison.OrdinalIgnoreCase))
if (!long.TryParse(header.Substring("Content-Length: ".Length), out contentlength))
contentlength = -1;
logger.WriteDebugMessage("Writing: " + header);
await target.WriteAsync(buf, lastmatch, (ix - lastmatch) + 2, canceltoken.Token);
}
}
lastmatch = ix + 2;
}
//await logger.WriteDebugMessageAsync(string.Format("Buf stats: {0},{1},{2},{3}", buf.Length, ix, offset, lastmatch));
ix = Array.IndexOf(buf, (byte)13, ix + 1, offset - ix - 1);
}
}
}
private static async Task ForwardRequest(StreamWriter sw, string path, LogHandler logger)
{
var canceltoken = new CancellationTokenSource();
var env = Environment.GetEnvironmentVariables();
/*foreach (var k in env.Keys)
logger.WriteDebugMessage(string.Format("{0}: {1}", k, env[k]));*/
await sw.WriteAsync(string.Format("{0} {1} HTTP/1.1{2}", GetEnvArg("REQUEST_METHOD", "").Trim(), path, CRLF));
logger.WriteDebugMessage("Wrote request header line");
foreach (var key in env.Keys.Cast<string>().Where<string>(x => x.StartsWith("HTTP_")))
await sw.WriteAsync(string.Format("{0}: {1}{2}", key.Substring("HTTP_".Length).Replace("_", "-"), env[key], CRLF));
if (!string.IsNullOrWhiteSpace(GetEnvArg("CONTENT_TYPE")))
await sw.WriteAsync(string.Format("{0}: {1}{2}", "Content-Type", GetEnvArg("CONTENT_TYPE"), CRLF));
if (!string.IsNullOrWhiteSpace(GetEnvArg("CONTENT_LENGTH")))
await sw.WriteAsync(string.Format("{0}: {1}{2}", "Content-Length", GetEnvArg("CONTENT_LENGTH"), CRLF));
await sw.WriteAsync(string.Format("{0}: {1}{2}", "Connection", "close", CRLF));
await sw.WriteAsync(CRLF);
await sw.FlushAsync();
logger.WriteDebugMessage("Wrote all header lines");
if (new string[] { "POST", "PUT", "PATCH" }.Contains(GetEnvArg("REQUEST_METHOD", "").Trim().ToUpper()))
{
logger.WriteDebugMessage(string.Format("Copying StdIn"));
using(var stdin = Console.OpenStandardInput())
{
logger.WriteDebugMessage("Opened StdIn");
long reqsize;
if (!long.TryParse(GetEnvArg("CONTENT_LENGTH"), out reqsize))
reqsize = long.MaxValue;
var buf = new byte[4 * 1024 * 1024];
var r = 0;
while(reqsize > 0)
{
logger.WriteDebugMessage(string.Format("Remaining {0} bytes from stdin", reqsize));
r = await stdin.ReadAsync(buf, 0, buf.Length, canceltoken.Token);
logger.WriteDebugMessage(string.Format("Got {0} bytes from stdin", r));
if (r == 0)
break;
reqsize -= r;
await sw.BaseStream.WriteAsync(buf, 0, r, canceltoken.Token);
}
}
logger.WriteDebugMessage("Copy stdin done");
}
logger.WriteDebugMessage("Completed writing request");
}
}
}