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DiffusionSubversionServeSSHWorkflow.php
10c4dedd1830production

DiffusionSubversionServeSSHWorkflow.php
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			<?php

			/**
			* This protocol has a good spec here:
			*
			* http://svn.apache.org/repos/asf/subversion/trunk/subversion/libsvn_ra_svn/protocol
			*/
			final class DiffusionSubversionServeSSHWorkflow
			extends DiffusionSubversionSSHWorkflow {

			private $didSeeWrite;

			private $inProtocol;
			private $outProtocol;

			private $inSeenGreeting;

			private $outPhaseCount = 0;

			private $internalBaseURI;
			private $externalBaseURI;
			private $peekBuffer;
			private $command;
			private $isProxying;

			private function getCommand() {
			return $this->command;
			}

			protected function didConstruct() {
			$this->setName('svnserve');
			$this->setArguments(
			array(
			array(
			'name' => 'tunnel',
			'short' => 't',
			),
			));
			}

			protected function identifyRepository() {
			// NOTE: In SVN, we need to read the first few protocol frames before we
			// can determine which repository the user is trying to access. We're
			// going to peek at the data on the wire to identify the repository.

			$io_channel = $this->getIOChannel();

			// Before the client will send us the first protocol frame, we need to send
			// it a connection frame with server capabilities. To figure out the
			// correct frame we're going to start `svnserve`, read the frame from it,
			// send it to the client, then kill the subprocess.

			// TODO: This is pretty inelegant and the protocol frame will change very
			// rarely. We could cache it if we can find a reasonable way to dirty the
			// cache.

			$command = csprintf('svnserve -t');
			$command = PhabricatorDaemon::sudoCommandAsDaemonUser($command);
			$future = new ExecFuture('%C', $command);
			$exec_channel = new PhutilExecChannel($future);
			$exec_protocol = new DiffusionSubversionWireProtocol();

			while (true) {
			PhutilChannel::waitForAny(array($exec_channel));
			$exec_channel->update();

			$exec_message = $exec_channel->read();
			if ($exec_message !== null) {
			$messages = $exec_protocol->writeData($exec_message);
			if ($messages) {
			$message = head($messages);
			$raw = $message['raw'];

			// Write the greeting frame to the client.
			$io_channel->write($raw);

			// Kill the subprocess.
			$future->resolveKill();
			break;
			}
			}

			if (!$exec_channel->isOpenForReading()) {
			throw new Exception(
			pht(
			'%s subprocess exited before emitting a protocol frame.',
			'svnserve'));
			}
			}

			$io_protocol = new DiffusionSubversionWireProtocol();
			while (true) {
			PhutilChannel::waitForAny(array($io_channel));
			$io_channel->update();

			$in_message = $io_channel->read();
			if ($in_message !== null) {
			$this->peekBuffer .= $in_message;
			if (strlen($this->peekBuffer) > (1024 * 1024)) {
			throw new Exception(
			pht(
			'Client transmitted more than 1MB of data without transmitting '.
			'a recognizable protocol frame.'));
			}

			$messages = $io_protocol->writeData($in_message);
			if ($messages) {
			$message = head($messages);
			$struct = $message['structure'];

			// This is the:
			//
			// ( version ( cap1 ... ) url ... )
			//
			// The `url` allows us to identify the repository.

			$uri = $struct[2]['value'];
			$path = $this->getPathFromSubversionURI($uri);

			return $this->loadRepositoryWithPath(
			$path,
			PhabricatorRepositoryType::REPOSITORY_TYPE_SVN);
			}
			}

			if (!$io_channel->isOpenForReading()) {
			throw new Exception(
			pht(
			'Client closed connection before sending a complete protocol '.
			'frame.'));
			}

			// If the client has disconnected, kill the subprocess and bail.
			if (!$io_channel->isOpenForWriting()) {
			throw new Exception(
			pht(
			'Client closed connection before receiving response.'));
			}
			}
			}

			protected function executeRepositoryOperations() {
			$repository = $this->getRepository();

			$args = $this->getArgs();
			if (!$args->getArg('tunnel')) {
			throw new Exception(pht('Expected `%s`!', 'svnserve -t'));
			}

			if ($this->shouldProxy()) {
			$command = $this->getProxyCommand();
			$this->isProxying = true;
			$cwd = null;
			} else {
			$command = csprintf(
			'svnserve -t --tunnel-user=%s',
			$this->getUser()->getUsername());
			$cwd = PhabricatorEnv::getEmptyCWD();
			}

			$command = PhabricatorDaemon::sudoCommandAsDaemonUser($command);
			$future = new ExecFuture('%C', $command);

			// If we're receiving a commit, svnserve will fail to execute the commit
			// hook with an unhelpful error if the CWD isn't readable by the user we
			// are sudoing to. Switch to a readable, empty CWD before running
			// svnserve. See T10941.
			if ($cwd !== null) {
			$future->setCWD($cwd);
			}

			$this->inProtocol = new DiffusionSubversionWireProtocol();
			$this->outProtocol = new DiffusionSubversionWireProtocol();

			$this->command = id($this->newPassthruCommand())
			->setIOChannel($this->getIOChannel())
			->setCommandChannelFromExecFuture($future)
			->setWillWriteCallback(array($this, 'willWriteMessageCallback'))
			->setWillReadCallback(array($this, 'willReadMessageCallback'));

			$this->command->setPauseIOReads(true);

			$err = $this->command->execute();

			if (!$err && $this->didSeeWrite) {
			$this->getRepository()->writeStatusMessage(
			PhabricatorRepositoryStatusMessage::TYPE_NEEDS_UPDATE,
			PhabricatorRepositoryStatusMessage::CODE_OKAY);
			}

			return $err;
			}

			public function willWriteMessageCallback(
			PhabricatorSSHPassthruCommand $command,
			$message) {

			$proto = $this->inProtocol;
			$messages = $proto->writeData($message);

			$result = array();
			foreach ($messages as $message) {
			$message_raw = $message['raw'];
			$struct = $message['structure'];

			if (!$this->inSeenGreeting) {
			$this->inSeenGreeting = true;

			// The first message the client sends looks like:
			//
			// ( version ( cap1 ... ) url ... )
			//
			// We want to grab the URL, load the repository, make sure it exists and
			// is accessible, and then replace it with the location of the
			// repository on disk.

			$uri = $struct[2]['value'];
			$struct[2]['value'] = $this->makeInternalURI($uri);

			$message_raw = $proto->serializeStruct($struct);
			} else if (isset($struct[0]) && $struct[0]['type'] == 'word') {

			if (!$proto->isReadOnlyCommand($struct)) {
			$this->didSeeWrite = true;
			$this->requireWriteAccess($struct[0]['value']);
			}

			// Several other commands also pass in URLs. We need to translate
			// all of these into the internal representation; this also makes sure
			// they're valid and accessible.

			switch ($struct[0]['value']) {
			case 'reparent':
			// ( reparent ( url ) )
			$struct[1]['value'][0]['value'] = $this->makeInternalURI(
			$struct[1]['value'][0]['value']);
			$message_raw = $proto->serializeStruct($struct);
			break;
			case 'switch':
			// ( switch ( ( rev ) target recurse url ... ) )
			$struct[1]['value'][3]['value'] = $this->makeInternalURI(
			$struct[1]['value'][3]['value']);
			$message_raw = $proto->serializeStruct($struct);
			break;
			case 'diff':
			// ( diff ( ( rev ) target recurse ignore-ancestry url ... ) )
			$struct[1]['value'][4]['value'] = $this->makeInternalURI(
			$struct[1]['value'][4]['value']);
			$message_raw = $proto->serializeStruct($struct);
			break;
			case 'add-file':
			case 'add-dir':
			// ( add-file ( path dir-token file-token [ copy-path copy-rev ] ) )
			// ( add-dir ( path parent child [ copy-path copy-rev ] ) )
			if (isset($struct[1]['value'][3]['value'][0]['value'])) {
			$copy_from = $struct[1]['value'][3]['value'][0]['value'];
			$copy_from = $this->makeInternalURI($copy_from);
			$struct[1]['value'][3]['value'][0]['value'] = $copy_from;
			}
			$message_raw = $proto->serializeStruct($struct);
			break;
			}
			}

			$result[] = $message_raw;
			}

			if (!$result) {
			return null;
			}

			return implode('', $result);
			}

			public function willReadMessageCallback(
			PhabricatorSSHPassthruCommand $command,
			$message) {

			$proto = $this->outProtocol;
			$messages = $proto->writeData($message);

			$result = array();
			foreach ($messages as $message) {
			$message_raw = $message['raw'];
			$struct = $message['structure'];

			if (isset($struct[0]) && ($struct[0]['type'] == 'word')) {

			if ($struct[0]['value'] == 'success') {
			switch ($this->outPhaseCount) {
			case 0:
			// This is the "greeting", which announces capabilities.

			// We already sent this when we were figuring out which
			// repository this request is for, so we aren't going to send
			// it again.

			// Instead, we're going to replay the client's response (which
			// we also already read).

			$command = $this->getCommand();
			$command->writeIORead($this->peekBuffer);
			$command->setPauseIOReads(false);

			$message_raw = null;
			break;
			case 1:
			// This responds to the client greeting, and announces auth.
			break;
			case 2:
			// This responds to auth, which should be trivial over SSH.
			break;
			case 3:
			// This contains the URI of the repository. We need to edit it;
			// if it does not match what the client requested it will reject
			// the response.
			$struct[1]['value'][1]['value'] = $this->makeExternalURI(
			$struct[1]['value'][1]['value']);
			$message_raw = $proto->serializeStruct($struct);
			break;
			default:
			// We don't care about other protocol frames.
			break;
			}

			$this->outPhaseCount++;
			} else if ($struct[0]['value'] == 'failure') {
			// Find any error messages which include the internal URI, and
			// replace the text with the external URI.
			foreach ($struct[1]['value'] as $key => $error) {
			$code = $error['value'][0]['value'];
			$message = $error['value'][1]['value'];

			$message = str_replace(
			$this->internalBaseURI,
			$this->externalBaseURI,
			$message);

			// Derp derp derp derp derp. The structure looks like this:
			// ( failure ( ( code message ... ) ... ) )
			$struct[1]['value'][$key]['value'][1]['value'] = $message;
			}
			$message_raw = $proto->serializeStruct($struct);
			}

			}

			if ($message_raw !== null) {
			$result[] = $message_raw;
			}
			}

			if (!$result) {
			return null;
			}

			return implode('', $result);
			}

			private function getPathFromSubversionURI($uri_string) {
			$uri = new PhutilURI($uri_string);

			$proto = $uri->getProtocol();
			if ($proto !== 'svn+ssh') {
			throw new Exception(
			pht(
			'Protocol for URI "%s" MUST be "%s".',
			$uri_string,
			'svn+ssh'));
			}
			$path = $uri->getPath();

			// Subversion presumably deals with this, but make sure there's nothing
			// sketchy going on with the URI.
			if (preg_match('(/\\.\\./)', $path)) {
			throw new Exception(
			pht(
			'String "%s" is invalid in path specification "%s".',
			'/../',
			$uri_string));
			}

			$path = $this->normalizeSVNPath($path);

			return $path;
			}

			private function makeInternalURI($uri_string) {
			if ($this->isProxying) {
			return $uri_string;
			}

			$uri = new PhutilURI($uri_string);

			$repository = $this->getRepository();

			$path = $this->getPathFromSubversionURI($uri_string);
			$external_base = $this->getBaseRequestPath();

			// Replace "/diffusion/X" in the request with the repository local path,
			// so "/diffusion/X/master/" becomes "/path/to/repository/X/master/".
			$local_path = rtrim($repository->getLocalPath(), '/');
			$path = $local_path.substr($path, strlen($external_base));

			// NOTE: We are intentionally NOT removing username information from the
			// URI. Subversion retains it over the course of the request and considers
			// two repositories with different username identifiers to be distinct and
			// incompatible.

			$uri->setPath($path);

			// If this is happening during the handshake, these are the base URIs for
			// the request.
			if ($this->externalBaseURI === null) {
			$pre = (string)id(clone $uri)->setPath('');

			$external_path = $external_base;
			$external_path = $this->normalizeSVNPath($external_path);
			$this->externalBaseURI = $pre.$external_path;

			$internal_path = rtrim($repository->getLocalPath(), '/');
			$internal_path = $this->normalizeSVNPath($internal_path);
			$this->internalBaseURI = $pre.$internal_path;
			}

			return (string)$uri;
			}

			private function makeExternalURI($uri) {
			if ($this->isProxying) {
			return $uri;
			}

			$internal = $this->internalBaseURI;
			$external = $this->externalBaseURI;

			if (strncmp($uri, $internal, strlen($internal)) === 0) {
			$uri = $external.substr($uri, strlen($internal));
			}

			return $uri;
			}

			private function normalizeSVNPath($path) {
			// Subversion normalizes redundant slashes internally, so normalize them
			// here as well to make sure things match up.
			$path = preg_replace('(/+)', '/', $path);

			return $path;
			}

			}

phab/src/applications/diffusion/ssh/DiffusionSubversionServeSSHWorkflow.php10c4dedd1830production

DiffusionSubversionServeSSHWorkflow.phpView Options

phab/src/applications/diffusion/ssh/DiffusionSubversionServeSSHWorkflow.php
10c4dedd1830production

DiffusionSubversionServeSSHWorkflow.php
View Options