<?php
final class DiffusionServeController extends DiffusionController {
public static function isVCSRequest(AphrontRequest $request) {
if (!self::getCallsign($request)) {
return null;
}
$content_type = $request->getHTTPHeader('Content-Type');
$user_agent = idx($_SERVER, 'HTTP_USER_AGENT');
$vcs = null;
if ($request->getExists('service')) {
$service = $request->getStr('service');
// We get this initially for `info/refs`.
// Git also gives us a User-Agent like "git/1.8.2.3".
$vcs = PhabricatorRepositoryType::REPOSITORY_TYPE_GIT;
} else if (strncmp($user_agent, "git/", 4) === 0) {
$vcs = PhabricatorRepositoryType::REPOSITORY_TYPE_GIT;
} else if ($content_type == 'application/x-git-upload-pack-request') {
// We get this for `git-upload-pack`.
$vcs = PhabricatorRepositoryType::REPOSITORY_TYPE_GIT;
} else if ($content_type == 'application/x-git-receive-pack-request') {
// We get this for `git-receive-pack`.
$vcs = PhabricatorRepositoryType::REPOSITORY_TYPE_GIT;
} else if ($request->getExists('cmd')) {
// Mercurial also sends an Accept header like
// "application/mercurial-0.1", and a User-Agent like
// "mercurial/proto-1.0".
$vcs = PhabricatorRepositoryType::REPOSITORY_TYPE_MERCURIAL;
} else {
// Subversion also sends an initial OPTIONS request (vs GET/POST), and
// has a User-Agent like "SVN/1.8.3 (x86_64-apple-darwin11.4.2)
// serf/1.3.2".
$dav = $request->getHTTPHeader('DAV');
$dav = new PhutilURI($dav);
if ($dav->getDomain() === 'subversion.tigris.org') {
$vcs = PhabricatorRepositoryType::REPOSITORY_TYPE_SVN;
}
}
return $vcs;
}
private static function getCallsign(AphrontRequest $request) {
$uri = $request->getRequestURI();
$regex = '@^/diffusion/(?P<callsign>[A-Z]+)(/|$)@';
$matches = null;
if (!preg_match($regex, (string)$uri, $matches)) {
return null;
}
return $matches['callsign'];
}
public function processRequest() {
$request = $this->getRequest();
$callsign = self::getCallsign($request);
// If authentication credentials have been provided, try to find a user
// that actually matches those credentials.
if (isset($_SERVER['PHP_AUTH_USER']) && isset($_SERVER['PHP_AUTH_PW'])) {
$username = $_SERVER['PHP_AUTH_USER'];
$password = new PhutilOpaqueEnvelope($_SERVER['PHP_AUTH_PW']);
$viewer = $this->authenticateHTTPRepositoryUser($username, $password);
if (!$viewer) {
return new PhabricatorVCSResponse(
403,
pht('Invalid credentials.'));
}
} else {
// User hasn't provided credentials, which means we count them as
// being "not logged in".
$viewer = new PhabricatorUser();
}
$allow_public = PhabricatorEnv::getEnvConfig('policy.allow-public');
$allow_auth = PhabricatorEnv::getEnvConfig('diffusion.allow-http-auth');
if (!$allow_public) {
if (!$viewer->isLoggedIn()) {
if ($allow_auth) {
return new PhabricatorVCSResponse(
401,
pht('You must log in to access repositories.'));
} else {
return new PhabricatorVCSResponse(
403,
pht('Public and authenticated HTTP access are both forbidden.'));
}
}
}
try {
$repository = id(new PhabricatorRepositoryQuery())
->setViewer($viewer)
->withCallsigns(array($callsign))
->executeOne();
if (!$repository) {
return new PhabricatorVCSResponse(
404,
pht('No such repository exists.'));
}
} catch (PhabricatorPolicyException $ex) {
if ($viewer->isLoggedIn()) {
return new PhabricatorVCSResponse(
403,
pht('You do not have permission to access this repository.'));
} else {
if ($allow_auth) {
return new PhabricatorVCSResponse(
401,
pht('You must log in to access this repository.'));
} else {
return new PhabricatorVCSResponse(
403,
pht(
'This repository requires authentication, which is forbidden '.
'over HTTP.'));
}
}
}
if (!$repository->isTracked()) {
return new PhabricatorVCSResponse(
403,
pht('This repository is inactive.'));
}
$is_push = !$this->isReadOnlyRequest($repository);
switch ($repository->getServeOverHTTP()) {
case PhabricatorRepository::SERVE_READONLY:
if ($is_push) {
return new PhabricatorVCSResponse(
403,
pht('This repository is read-only over HTTP.'));
}
break;
case PhabricatorRepository::SERVE_READWRITE:
if ($is_push) {
$can_push = PhabricatorPolicyFilter::hasCapability(
$viewer,
$repository,
DiffusionCapabilityPush::CAPABILITY);
if (!$can_push) {
if ($viewer->isLoggedIn()) {
return new PhabricatorVCSResponse(
403,
pht('You do not have permission to push to this repository.'));
} else {
if ($allow_auth) {
return new PhabricatorVCSResponse(
401,
pht('You must log in to push to this repository.'));
} else {
return new PhabricatorVCSResponse(
403,
pht(
'Pushing to this repository requires authentication, '.
'which is forbidden over HTTP.'));
}
}
}
}
break;
case PhabricatorRepository::SERVE_OFF:
default:
return new PhabricatorVCSResponse(
403,
pht('This repository is not available over HTTP.'));
}
$vcs_type = $repository->getVersionControlSystem();
$req_type = $this->isVCSRequest($request);
if ($vcs_type != $req_type) {
switch ($req_type) {
case PhabricatorRepositoryType::REPOSITORY_TYPE_GIT:
$result = new PhabricatorVCSResponse(
500,
pht('This is not a Git repository.'));
break;
case PhabricatorRepositoryType::REPOSITORY_TYPE_MERCURIAL:
$result = new PhabricatorVCSResponse(
500,
pht('This is not a Mercurial repository.'));
break;
case PhabricatorRepositoryType::REPOSITORY_TYPE_SVN:
$result = new PhabricatorVCSResponse(
500,
pht('This is not a Subversion repository.'));
break;
default:
$result = new PhabricatorVCSResponse(
500,
pht('Unknown request type.'));
break;
}
} else {
switch ($vcs_type) {
case PhabricatorRepositoryType::REPOSITORY_TYPE_GIT:
$result = $this->serveGitRequest($repository, $viewer);
break;
case PhabricatorRepositoryType::REPOSITORY_TYPE_MERCURIAL:
$result = $this->serveMercurialRequest($repository, $viewer);
break;
case PhabricatorRepositoryType::REPOSITORY_TYPE_SVN:
$result = new PhabricatorVCSResponse(
500,
pht(
'Phabricator does not support HTTP access to Subversion '.
'repositories.'));
break;
default:
$result = new PhabricatorVCSResponse(
500,
pht('Unknown version control system.'));
break;
}
}
$code = $result->getHTTPResponseCode();
if ($is_push && ($code == 200)) {
$unguarded = AphrontWriteGuard::beginScopedUnguardedWrites();
$repository->writeStatusMessage(
PhabricatorRepositoryStatusMessage::TYPE_NEEDS_UPDATE,
PhabricatorRepositoryStatusMessage::CODE_OKAY);
unset($unguarded);
}
return $result;
}
private function isReadOnlyRequest(
PhabricatorRepository $repository) {
$request = $this->getRequest();
$method = $_SERVER['REQUEST_METHOD'];
// TODO: This implementation is safe by default, but very incomplete.
switch ($repository->getVersionControlSystem()) {
case PhabricatorRepositoryType::REPOSITORY_TYPE_GIT:
$service = $request->getStr('service');
$path = $this->getRequestDirectoryPath();
// NOTE: Service names are the reverse of what you might expect, as they
// are from the point of view of the server. The main read service is
// "git-upload-pack", and the main write service is "git-receive-pack".
if ($method == 'GET' &&
$path == '/info/refs' &&
$service == 'git-upload-pack') {
return true;
}
if ($path == '/git-upload-pack') {
return true;
}
break;
case PhabricatorRepositoryType::REPOSITORY_TYPE_MERCURIAL:
$cmd = $request->getStr('cmd');
if ($cmd == 'batch') {
$cmds = idx($this->getMercurialArguments(), 'cmds');
return DiffusionMercurialWireProtocol::isReadOnlyBatchCommand($cmds);
}
return DiffusionMercurialWireProtocol::isReadOnlyCommand($cmd);
case PhabricatorRepositoryType::REPOSITORY_TYPE_SVN:
break;
}
return false;
}
/**
* @phutil-external-symbol class PhabricatorStartup
*/
private function serveGitRequest(
PhabricatorRepository $repository,
PhabricatorUser $viewer) {
$request = $this->getRequest();
$request_path = $this->getRequestDirectoryPath();
$repository_root = $repository->getLocalPath();
// Rebuild the query string to strip `__magic__` parameters and prevent
// issues where we might interpret inputs like "service=read&service=write"
// differently than the server does and pass it an unsafe command.
// NOTE: This does not use getPassthroughRequestParameters() because
// that code is HTTP-method agnostic and will encode POST data.
$query_data = $_GET;
foreach ($query_data as $key => $value) {
if (!strncmp($key, '__', 2)) {
unset($query_data[$key]);
}
}
$query_string = http_build_query($query_data, '', '&');
// We're about to wipe out PATH with the rest of the environment, so
// resolve the binary first.
$bin = Filesystem::resolveBinary('git-http-backend');
if (!$bin) {
throw new Exception("Unable to find `git-http-backend` in PATH!");
}
$env = array(
'REQUEST_METHOD' => $_SERVER['REQUEST_METHOD'],
'QUERY_STRING' => $query_string,
'CONTENT_TYPE' => $request->getHTTPHeader('Content-Type'),
'HTTP_CONTENT_ENCODING' => $request->getHTTPHeader('Content-Encoding'),
'REMOTE_ADDR' => $_SERVER['REMOTE_ADDR'],
'GIT_PROJECT_ROOT' => $repository_root,
'GIT_HTTP_EXPORT_ALL' => '1',
'PATH_INFO' => $request_path,
'REMOTE_USER' => $viewer->getUsername(),
// TODO: Set these correctly.
// GIT_COMMITTER_NAME
// GIT_COMMITTER_EMAIL
);
$input = PhabricatorStartup::getRawInput();
list($err, $stdout, $stderr) = id(new ExecFuture('%s', $bin))
->setEnv($env, true)
->write($input)
->resolve();
if ($err) {
if ($this->isValidGitShallowCloneResponse($stdout, $stderr)) {
// Ignore the error if the response passes this special check for
// validity.
$err = 0;
}
}
if ($err) {
return new PhabricatorVCSResponse(
500,
pht('Error %d: %s', $err, $stderr));
}
return id(new DiffusionGitResponse())->setGitData($stdout);
}
private function getRequestDirectoryPath() {
$request = $this->getRequest();
$request_path = $request->getRequestURI()->getPath();
return preg_replace('@^/diffusion/[A-Z]+@', '', $request_path);
}
private function authenticateHTTPRepositoryUser(
$username,
PhutilOpaqueEnvelope $password) {
if (!PhabricatorEnv::getEnvConfig('diffusion.allow-http-auth')) {
// No HTTP auth permitted.
return null;
}
if (!strlen($username)) {
// No username.
return null;
}
if (!strlen($password->openEnvelope())) {
// No password.
return null;
}
$user = id(new PhabricatorPeopleQuery())
->setViewer(PhabricatorUser::getOmnipotentUser())
->withUsernames(array($username))
->executeOne();
if (!$user) {
// Username doesn't match anything.
return null;
}
$password_entry = id(new PhabricatorRepositoryVCSPassword())
->loadOneWhere('userPHID = %s', $user->getPHID());
if (!$password_entry) {
// User doesn't have a password set.
return null;
}
if (!$password_entry->comparePassword($password, $user)) {
// Password doesn't match.
return null;
}
if ($user->getIsDisabled()) {
// User is disabled.
return null;
}
return $user;
}
private function serveMercurialRequest(PhabricatorRepository $repository) {
$request = $this->getRequest();
$bin = Filesystem::resolveBinary('hg');
if (!$bin) {
throw new Exception("Unable to find `hg` in PATH!");
}
$env = array();
$input = PhabricatorStartup::getRawInput();
$cmd = $request->getStr('cmd');
$args = $this->getMercurialArguments();
$args = $this->formatMercurialArguments($cmd, $args);
if (strlen($input)) {
$input = strlen($input)."\n".$input."0\n";
}
list($err, $stdout, $stderr) = id(new ExecFuture('%s serve --stdio', $bin))
->setEnv($env, true)
->setCWD($repository->getLocalPath())
->write("{$cmd}\n{$args}{$input}")
->resolve();
if ($err) {
return new PhabricatorVCSResponse(
500,
pht('Error %d: %s', $err, $stderr));
}
if ($cmd == 'getbundle' ||
$cmd == 'changegroup' ||
$cmd == 'changegroupsubset') {
// We're not completely sure that "changegroup" and "changegroupsubset"
// actually work, they're for very old Mercurial.
$body = gzcompress($stdout);
} else if ($cmd == 'unbundle') {
// This includes diagnostic information and anything echoed by commit
// hooks. We ignore `stdout` since it just has protocol garbage, and
// substitute `stderr`.
$body = strlen($stderr)."\n".$stderr;
} else {
list($length, $body) = explode("\n", $stdout, 2);
}
return id(new DiffusionMercurialResponse())->setContent($body);
}
private function getMercurialArguments() {
// Mercurial sends arguments in HTTP headers. "Why?", you might wonder,
// "Why would you do this?".
$args_raw = array();
for ($ii = 1; ; $ii++) {
$header = 'HTTP_X_HGARG_'.$ii;
if (!array_key_exists($header, $_SERVER)) {
break;
}
$args_raw[] = $_SERVER[$header];
}
$args_raw = implode('', $args_raw);
return id(new PhutilQueryStringParser())
->parseQueryString($args_raw);
}
private function formatMercurialArguments($command, array $arguments) {
$spec = DiffusionMercurialWireProtocol::getCommandArgs($command);
$out = array();
// Mercurial takes normal arguments like this:
//
// name <length(value)>
// value
$has_star = false;
foreach ($spec as $arg_key) {
if ($arg_key == '*') {
$has_star = true;
continue;
}
if (isset($arguments[$arg_key])) {
$value = $arguments[$arg_key];
$size = strlen($value);
$out[] = "{$arg_key} {$size}\n{$value}";
unset($arguments[$arg_key]);
}
}
if ($has_star) {
// Mercurial takes arguments for variable argument lists roughly like
// this:
//
// * <count(args)>
// argname1 <length(argvalue1)>
// argvalue1
// argname2 <length(argvalue2)>
// argvalue2
$count = count($arguments);
$out[] = "* {$count}\n";
foreach ($arguments as $key => $value) {
if (in_array($key, $spec)) {
// We already added this argument above, so skip it.
continue;
}
$size = strlen($value);
$out[] = "{$key} {$size}\n{$value}";
}
}
return implode('', $out);
}
private function isValidGitShallowCloneResponse($stdout, $stderr) {
// If you execute `git clone --depth N ...`, git sends a request which
// `git-http-backend` responds to by emitting valid output and then exiting
// with a failure code and an error message. If we ignore this error,
// everything works.
// This is a pretty funky fix: it would be nice to more precisely detect
// that a request is a `--depth N` clone request, but we don't have any code
// to decode protocol frames yet. Instead, look for reasonable evidence
// in the error and output that we're looking at a `--depth` clone.
// For evidence this isn't completely crazy, see:
// https://github.com/schacon/grack/pull/7
$stdout_regexp = '(^Content-Type: application/x-git-upload-pack-result)m';
$stderr_regexp = '(The remote end hung up unexpectedly)';
$has_pack = preg_match($stdout_regexp, $stdout);
$is_hangup = preg_match($stderr_regexp, $stderr);
return $has_pack && $is_hangup;
}
}