Async, streaming plaintext TCP/IP and secure TLS socket server and client connections for ReactPHP
The socket library provides re-usable interfaces for a socket-layer
server and client based on the EventLoop
and Stream
components.
Its server component allows you to build networking servers that accept incoming
connections from networking clients (such as an HTTP server).
Its client component allows you to build networking clients that establish
outgoing connections to networking servers (such as an HTTP or database client).
This library provides async, streaming means for all of this, so you can
handle multiple concurrent connections without blocking.
Table of Contents
Here is a server that closes the connection if you send it anything:
$loop = React\EventLoop\Factory::create();
$socket = new React\Socket\Server('127.0.0.1:8080', $loop);
$socket->on('connection', function (ConnectionInterface $conn) {
$conn->write("Hello " . $conn->getRemoteAddress() . "!\n");
$conn->write("Welcome to this amazing server!\n");
$conn->write("Here's a tip: don't say anything.\n");
$conn->on('data', function ($data) use ($conn) {
$conn->close();
});
});
$loop->run();
See also the examples.
Here's a client that outputs the output of said server and then attempts to send it a string:
$loop = React\EventLoop\Factory::create();
$connector = new React\Socket\Connector($loop);
$connector->connect('127.0.0.1:8080')->then(function (ConnectionInterface $conn) use ($loop) {
$conn->pipe(new React\Stream\WritableResourceStream(STDOUT, $loop));
$conn->write("Hello World!\n");
});
$loop->run();
The ConnectionInterface
is used to represent any incoming and outgoing
connection, such as a normal TCP/IP connection.
An incoming or outgoing connection is a duplex stream (both readable and
writable) that implements React's
DuplexStreamInterface
.
It contains additional properties for the local and remote address (client IP)
where this connection has been established to/from.
Most commonly, instances implementing this ConnectionInterface
are emitted
by all classes implementing the ServerInterface
and
used by all classes implementing the ConnectorInterface
.
Because the ConnectionInterface
implements the underlying
DuplexStreamInterface
you can use any of its events and methods as usual:
$connection->on('data', function ($chunk) {
echo $chunk;
});
$connection->on('end', function () {
echo 'ended';
});
$connection->on('error', function (Exception $e) {
echo 'error: ' . $e->getMessage();
});
$connection->on('close', function () {
echo 'closed';
});
$connection->write($data);
$connection->end($data = null);
$connection->close();
// …
For more details, see the
DuplexStreamInterface
.
The getRemoteAddress(): ?string
method returns the full remote address
(URI) where this connection has been established with.
$address = $connection->getRemoteAddress();
echo 'Connection with ' . $address . PHP_EOL;
If the remote address can not be determined or is unknown at this time (such as
after the connection has been closed), it MAY return a NULL
value instead.
Otherwise, it will return the full address (URI) as a string value, such
as tcp://127.0.0.1:8080
, tcp://[::1]:80
, tls://127.0.0.1:443
,
unix://example.sock
or unix:///path/to/example.sock
.
Note that individual URI components are application specific and depend
on the underlying transport protocol.
If this is a TCP/IP based connection and you only want the remote IP, you may use something like this:
$address = $connection->getRemoteAddress();
$ip = trim(parse_url($address, PHP_URL_HOST), '[]');
echo 'Connection with ' . $ip . PHP_EOL;
The getLocalAddress(): ?string
method returns the full local address
(URI) where this connection has been established with.
$address = $connection->getLocalAddress();
echo 'Connection with ' . $address . PHP_EOL;
If the local address can not be determined or is unknown at this time (such as
after the connection has been closed), it MAY return a NULL
value instead.
Otherwise, it will return the full address (URI) as a string value, such
as tcp://127.0.0.1:8080
, tcp://[::1]:80
, tls://127.0.0.1:443
,
unix://example.sock
or unix:///path/to/example.sock
.
Note that individual URI components are application specific and depend
on the underlying transport protocol.
This method complements the getRemoteAddress()
method,
so they should not be confused.
If your TcpServer
instance is listening on multiple interfaces (e.g. using
the address 0.0.0.0
), you can use this method to find out which interface
actually accepted this connection (such as a public or local interface).
If your system has multiple interfaces (e.g. a WAN and a LAN interface), you can use this method to find out which interface was actually used for this connection.
The ServerInterface
is responsible for providing an interface for accepting
incoming streaming connections, such as a normal TCP/IP connection.
Most higher-level components (such as a HTTP server) accept an instance implementing this interface to accept incoming streaming connections. This is usually done via dependency injection, so it's fairly simple to actually swap this implementation against any other implementation of this interface. This means that you SHOULD typehint against this interface instead of a concrete implementation of this interface.
Besides defining a few methods, this interface also implements the
EventEmitterInterface
which allows you to react to certain events.
The connection
event will be emitted whenever a new connection has been
established, i.e. a new client connects to this server socket:
$server->on('connection', function (ConnectionInterface $connection) {
echo 'new connection' . PHP_EOL;
});
See also the ConnectionInterface
for more details
about handling the incoming connection.
The error
event will be emitted whenever there's an error accepting a new
connection from a client.
$server->on('error', function (Exception $e) {
echo 'error: ' . $e->getMessage() . PHP_EOL;
});
Note that this is not a fatal error event, i.e. the server keeps listening for new connections even after this event.
The getAddress(): ?string
method can be used to
return the full address (URI) this server is currently listening on.
$address = $server->getAddress();
echo 'Server listening on ' . $address . PHP_EOL;
If the address can not be determined or is unknown at this time (such as
after the socket has been closed), it MAY return a NULL
value instead.
Otherwise, it will return the full address (URI) as a string value, such
as tcp://127.0.0.1:8080
, tcp://[::1]:80
or tls://127.0.0.1:443
.
Note that individual URI components are application specific and depend
on the underlying transport protocol.
If this is a TCP/IP based server and you only want the local port, you may use something like this:
$address = $server->getAddress();
$port = parse_url($address, PHP_URL_PORT);
echo 'Server listening on port ' . $port . PHP_EOL;
The pause(): void
method can be used to
pause accepting new incoming connections.
Removes the socket resource from the EventLoop and thus stop accepting new connections. Note that the listening socket stays active and is not closed.
This means that new incoming connections will stay pending in the operating system backlog until its configurable backlog is filled. Once the backlog is filled, the operating system may reject further incoming connections until the backlog is drained again by resuming to accept new connections.
Once the server is paused, no futher connection
events SHOULD
be emitted.
$server->pause();
$server->on('connection', assertShouldNeverCalled());
This method is advisory-only, though generally not recommended, the
server MAY continue emitting connection
events.
Unless otherwise noted, a successfully opened server SHOULD NOT start in paused state.
You can continue processing events by calling resume()
again.
Note that both methods can be called any number of times, in particular
calling pause()
more than once SHOULD NOT have any effect.
Similarly, calling this after close()
is a NO-OP.
The resume(): void
method can be used to
resume accepting new incoming connections.
Re-attach the socket resource to the EventLoop after a previous pause()
.
$server->pause();
$loop->addTimer(1.0, function () use ($server) {
$server->resume();
});
Note that both methods can be called any number of times, in particular
calling resume()
without a prior pause()
SHOULD NOT have any effect.
Similarly, calling this after close()
is a NO-OP.
The close(): void
method can be used to
shut down this listening socket.
This will stop listening for new incoming connections on this socket.
echo 'Shutting down server socket' . PHP_EOL;
$server->close();
Calling this method more than once on the same instance is a NO-OP.
The Server
class is the main class in this package that implements the
ServerInterface
and allows you to accept incoming
streaming connections, such as plaintext TCP/IP or secure TLS connection streams.
$server = new Server(8080, $loop);
As above, the $uri
parameter can consist of only a port, in which case the
server will default to listening on the localhost address 127.0.0.1
,
which means it will not be reachable from outside of this system.
In order to use a random port assignment, you can use the port 0
:
$server = new Server(0, $loop);
$address = $server->getAddress();
In order to change the host the socket is listening on, you can provide an IP
address through the first parameter provided to the constructor, optionally
preceded by the tcp://
scheme:
$server = new Server('192.168.0.1:8080', $loop);
If you want to listen on an IPv6 address, you MUST enclose the host in square brackets:
$server = new Server('[::1]:8080', $loop);
If the given URI is invalid, does not contain a port, any other scheme or if it
contains a hostname, it will throw an InvalidArgumentException
:
// throws InvalidArgumentException due to missing port
$server = new Server('127.0.0.1', $loop);
If the given URI appears to be valid, but listening on it fails (such as if port
is already in use or port below 1024 may require root access etc.), it will
throw a RuntimeException
:
$first = new Server(8080, $loop);
// throws RuntimeException because port is already in use
$second = new Server(8080, $loop);
Note that these error conditions may vary depending on your system and/or configuration. See the exception message and code for more details about the actual error condition.
Optionally, you can specify TCP socket context options for the underlying stream socket resource like this:
$server = new Server('[::1]:8080', $loop, array(
'tcp' => array(
'backlog' => 200,
'so_reuseport' => true,
'ipv6_v6only' => true
)
));
Note that available socket context options, their defaults and effects of changing these may vary depending on your system and/or PHP version. Passing unknown context options has no effect. For BC reasons, you can also pass the TCP socket context options as a simple array without wrapping this in another array under the
tcp
key.
You can start a secure TLS (formerly known as SSL) server by simply prepending
the tls://
URI scheme.
Internally, it will wait for plaintext TCP/IP connections and then performs a
TLS handshake for each connection.
It thus requires valid TLS context options,
which in its most basic form may look something like this if you're using a
PEM encoded certificate file:
$server = new Server('tls://127.0.0.1:8080', $loop, array(
'tls' => array(
'local_cert' => 'server.pem'
)
));
Note that the certificate file will not be loaded on instantiation but when an incoming connection initializes its TLS context. This implies that any invalid certificate file paths or contents will only cause an
error
event at a later time.
If your private key is encrypted with a passphrase, you have to specify it like this:
$server = new Server('tls://127.0.0.1:8000', $loop, array(
'tls' => array(
'local_cert' => 'server.pem',
'passphrase' => 'secret'
)
));
Note that available TLS context options, their defaults and effects of changing these may vary depending on your system and/or PHP version. The outer context array allows you to also use
tcp
(and possibly more) context options at the same time. Passing unknown context options has no effect. If you do not use thetls://
scheme, then passingtls
context options has no effect.
Whenever a client connects, it will emit a connection
event with a connection
instance implementing ConnectionInterface
:
$server->on('connection', function (ConnectionInterface $connection) {
echo 'Plaintext connection from ' . $connection->getRemoteAddress() . PHP_EOL;
$connection->write('hello there!' . PHP_EOL);
…
});
See also the ServerInterface
for more details.
Note that the
Server
class is a concrete implementation for TCP/IP sockets. If you want to typehint in your higher-level protocol implementation, you SHOULD use the genericServerInterface
instead.
The TcpServer
class implements the ServerInterface
and
is responsible for accepting plaintext TCP/IP connections.
$server = new TcpServer(8080, $loop);
As above, the $uri
parameter can consist of only a port, in which case the
server will default to listening on the localhost address 127.0.0.1
,
which means it will not be reachable from outside of this system.
In order to use a random port assignment, you can use the port 0
:
$server = new TcpServer(0, $loop);
$address = $server->getAddress();
In order to change the host the socket is listening on, you can provide an IP
address through the first parameter provided to the constructor, optionally
preceded by the tcp://
scheme:
$server = new TcpServer('192.168.0.1:8080', $loop);
If you want to listen on an IPv6 address, you MUST enclose the host in square brackets:
$server = new TcpServer('[::1]:8080', $loop);
If the given URI is invalid, does not contain a port, any other scheme or if it
contains a hostname, it will throw an InvalidArgumentException
:
// throws InvalidArgumentException due to missing port
$server = new TcpServer('127.0.0.1', $loop);
If the given URI appears to be valid, but listening on it fails (such as if port
is already in use or port below 1024 may require root access etc.), it will
throw a RuntimeException
:
$first = new TcpServer(8080, $loop);
// throws RuntimeException because port is already in use
$second = new TcpServer(8080, $loop);
Note that these error conditions may vary depending on your system and/or configuration. See the exception message and code for more details about the actual error condition.
Optionally, you can specify socket context options for the underlying stream socket resource like this:
$server = new TcpServer('[::1]:8080', $loop, array(
'backlog' => 200,
'so_reuseport' => true,
'ipv6_v6only' => true
));
Note that available socket context options, their defaults and effects of changing these may vary depending on your system and/or PHP version. Passing unknown context options has no effect.
Whenever a client connects, it will emit a connection
event with a connection
instance implementing ConnectionInterface
:
$server->on('connection', function (ConnectionInterface $connection) {
echo 'Plaintext connection from ' . $connection->getRemoteAddress() . PHP_EOL;
$connection->write('hello there!' . PHP_EOL);
…
});
See also the ServerInterface
for more details.
The SecureServer
class implements the ServerInterface
and is responsible for providing a secure TLS (formerly known as SSL) server.
It does so by wrapping a TcpServer
instance which waits for plaintext
TCP/IP connections and then performs a TLS handshake for each connection.
It thus requires valid TLS context options,
which in its most basic form may look something like this if you're using a
PEM encoded certificate file:
$server = new TcpServer(8000, $loop);
$server = new SecureServer($server, $loop, array(
'local_cert' => 'server.pem'
));
Note that the certificate file will not be loaded on instantiation but when an incoming connection initializes its TLS context. This implies that any invalid certificate file paths or contents will only cause an
error
event at a later time.
If your private key is encrypted with a passphrase, you have to specify it like this:
$server = new TcpServer(8000, $loop);
$server = new SecureServer($server, $loop, array(
'local_cert' => 'server.pem',
'passphrase' => 'secret'
));
Note that available TLS context options, their defaults and effects of changing these may vary depending on your system and/or PHP version. Passing unknown context options has no effect.
Whenever a client completes the TLS handshake, it will emit a connection
event
with a connection instance implementing ConnectionInterface
:
$server->on('connection', function (ConnectionInterface $connection) {
echo 'Secure connection from' . $connection->getRemoteAddress() . PHP_EOL;
$connection->write('hello there!' . PHP_EOL);
…
});
Whenever a client fails to perform a successful TLS handshake, it will emit an
error
event and then close the underlying TCP/IP connection:
$server->on('error', function (Exception $e) {
echo 'Error' . $e->getMessage() . PHP_EOL;
});
See also the ServerInterface
for more details.
Note that the SecureServer
class is a concrete implementation for TLS sockets.
If you want to typehint in your higher-level protocol implementation, you SHOULD
use the generic ServerInterface
instead.
Advanced usage: Despite allowing any
ServerInterface
as first parameter, you SHOULD pass aTcpServer
instance as first parameter, unless you know what you're doing. Internally, theSecureServer
has to set the required TLS context options on the underlying stream resources. These resources are not exposed through any of the interfaces defined in this package, but only through the internalConnection
class. TheTcpServer
class is guaranteed to emit connections that implement theConnectionInterface
and uses the internalConnection
class in order to expose these underlying resources. If you use a customServerInterface
and itsconnection
event does not meet this requirement, theSecureServer
will emit anerror
event and then close the underlying connection.
The LimitingServer
decorator wraps a given ServerInterface
and is responsible
for limiting and keeping track of open connections to this server instance.
Whenever the underlying server emits a connection
event, it will check its
limits and then either
connection
eventerror
event instead.Whenever a connection closes, it will remove this connection from the list of open connections.
$server = new LimitingServer($server, 100);
$server->on('connection', function (ConnectionInterface $connection) {
$connection->write('hello there!' . PHP_EOL);
…
});
See also the second example for more details.
You have to pass a maximum number of open connections to ensure
the server will automatically reject (close) connections once this limit
is exceeded. In this case, it will emit an error
event to inform about
this and no connection
event will be emitted.
$server = new LimitingServer($server, 100);
$server->on('connection', function (ConnectionInterface $connection) {
$connection->write('hello there!' . PHP_EOL);
…
});
You MAY pass a null
limit in order to put no limit on the number of
open connections and keep accepting new connection until you run out of
operating system resources (such as open file handles). This may be
useful it you do not want to take care of applying a limit but still want
to use the getConnections()
method.
You can optionally configure the server to pause accepting new connections once the connection limit is reached. In this case, it will pause the underlying server and no longer process any new connections at all, thus also no longer closing any excessive connections. The underlying operating system is responsible for keeping a backlog of pending connections until its limit is reached, at which point it will start rejecting further connections. Once the server is below the connection limit, it will continue consuming connections from the backlog and will process any outstanding data on each connection. This mode may be useful for some protocols that are designed to wait for a response message (such as HTTP), but may be less useful for other protocols that demand immediate responses (such as a "welcome" message in an interactive chat).
$server = new LimitingServer($server, 100, true);
$server->on('connection', function (ConnectionInterface $connection) {
$connection->write('hello there!' . PHP_EOL);
…
});
The getConnections(): ConnectionInterface[]
method can be used to
return an array with all currently active connections.
foreach ($server->getConnection() as $connection) {
$connection->write('Hi!');
}
The ConnectorInterface
is responsible for providing an interface for
establishing streaming connections, such as a normal TCP/IP connection.
This is the main interface defined in this package and it is used throughout React's vast ecosystem.
Most higher-level components (such as HTTP, database or other networking service clients) accept an instance implementing this interface to create their TCP/IP connection to the underlying networking service. This is usually done via dependency injection, so it's fairly simple to actually swap this implementation against any other implementation of this interface.
The interface only offers a single method:
The connect(string $uri): PromiseInterface<ConnectionInterface, Exception>
method
can be used to create a streaming connection to the given remote address.
It returns a Promise which either
fulfills with a stream implementing ConnectionInterface
on success or rejects with an Exception
if the connection is not successful:
$connector->connect('google.com:443')->then(
function (ConnectionInterface $connection) {
// connection successfully established
},
function (Exception $error) {
// failed to connect due to $error
}
);
See also ConnectionInterface
for more details.
The returned Promise MUST be implemented in such a way that it can be
cancelled when it is still pending. Cancelling a pending promise MUST
reject its value with an Exception
. It SHOULD clean up any underlying
resources and references as applicable:
$promise = $connector->connect($uri);
$promise->cancel();
The Connector
class is the main class in this package that implements the
ConnectorInterface
and allows you to create streaming connections.
You can use this connector to create any kind of streaming connections, such as plaintext TCP/IP, secure TLS or local Unix connection streams.
It binds to the main event loop and can be used like this:
$loop = React\EventLoop\Factory::create();
$connector = new Connector($loop);
$connector->connect($uri)->then(function (ConnectionInterface $connection) {
$connection->write('...');
$connection->end();
});
$loop->run();
In order to create a plaintext TCP/IP connection, you can simply pass a host and port combination like this:
$connector->connect('www.google.com:80')->then(function (ConnectionInterface $connection) {
$connection->write('...');
$connection->end();
});
If you do no specify a URI scheme in the destination URI, it will assume
tcp://
as a default and establish a plaintext TCP/IP connection. Note that TCP/IP connections require a host and port part in the destination URI like above, all other URI components are optional.
In order to create a secure TLS connection, you can use the tls://
URI scheme
like this:
$connector->connect('tls://www.google.com:443')->then(function (ConnectionInterface $connection) {
$connection->write('...');
$connection->end();
});
In order to create a local Unix domain socket connection, you can use the
unix://
URI scheme like this:
$connector->connect('unix:///tmp/demo.sock')->then(function (ConnectionInterface $connection) {
$connection->write('...');
$connection->end();
});
The
getRemoteAddress()
method will return the target Unix domain socket (UDS) path as given to theconnect()
method, including theunix://
scheme, for exampleunix:///tmp/demo.sock
. ThegetLocalAddress()
method will most likely return anull
value as this value is not applicable to UDS connections here.
Under the hood, the Connector
is implemented as a higher-level facade
for the lower-level connectors implemented in this package. This means it
also shares all of their features and implementation details.
If you want to typehint in your higher-level protocol implementation, you SHOULD
use the generic ConnectorInterface
instead.
In particular, the Connector
class uses Google's public DNS server 8.8.8.8
to resolve all hostnames into underlying IP addresses by default.
This implies that it also ignores your hosts
file and resolve.conf
, which
means you won't be able to connect to localhost
and other non-public
hostnames by default.
If you want to use a custom DNS server (such as a local DNS relay), you can set
up the Connector
like this:
$connector = new Connector($loop, array(
'dns' => '127.0.1.1'
));
$connector->connect('localhost:80')->then(function (ConnectionInterface $connection) {
$connection->write('...');
$connection->end();
});
If you do not want to use a DNS resolver at all and want to connect to IP
addresses only, you can also set up your Connector
like this:
$connector = new Connector($loop, array(
'dns' => false
));
$connector->connect('127.0.0.1:80')->then(function (ConnectionInterface $connection) {
$connection->write('...');
$connection->end();
});
Advanced: If you need a custom DNS Resolver
instance, you can also set up
your Connector
like this:
$dnsResolverFactory = new React\Dns\Resolver\Factory();
$resolver = $dnsResolverFactory->createCached('127.0.1.1', $loop);
$connector = new Connector($loop, array(
'dns' => $resolver
));
$connector->connect('localhost:80')->then(function (ConnectionInterface $connection) {
$connection->write('...');
$connection->end();
});
By default, the tcp://
and tls://
URI schemes will use timeout value that
repects your default_socket_timeout
ini setting (which defaults to 60s).
If you want a custom timeout value, you can simply pass this like this:
$connector = new Connector($loop, array(
'timeout' => 10.0
));
Similarly, if you do not want to apply a timeout at all and let the operating system handle this, you can pass a boolean flag like this:
$connector = new Connector($loop, array(
'timeout' => false
));
By default, the Connector
supports the tcp://
, tls://
and unix://
URI schemes. If you want to explicitly prohibit any of these, you can simply
pass boolean flags like this:
// only allow secure TLS connections
$connector = new Connector($loop, array(
'tcp' => false,
'tls' => true,
'unix' => false,
));
$connector->connect('tls://google.com:443')->then(function (ConnectionInterface $connection) {
$connection->write('...');
$connection->end();
});
The tcp://
and tls://
also accept additional context options passed to
the underlying connectors.
If you want to explicitly pass additional context options, you can simply
pass arrays of context options like this:
// allow insecure TLS connections
$connector = new Connector($loop, array(
'tcp' => array(
'bindto' => '192.168.0.1:0'
),
'tls' => array(
'verify_peer' => false,
'verify_peer_name' => false
),
));
$connector->connect('tls://localhost:443')->then(function (ConnectionInterface $connection) {
$connection->write('...');
$connection->end();
});
For more details about context options, please refer to the PHP documentation about socket context options and SSL context options.
Advanced: By default, the Connector
supports the tcp://
, tls://
and
unix://
URI schemes.
For this, it sets up the required connector classes automatically.
If you want to explicitly pass custom connectors for any of these, you can simply
pass an instance implementing the ConnectorInterface
like this:
$dnsResolverFactory = new React\Dns\Resolver\Factory();
$resolver = $dnsResolverFactory->createCached('127.0.1.1', $loop);
$tcp = new DnsConnector(new TcpConnector($loop), $resolver);
$tls = new SecureConnector($tcp, $loop);
$unix = new UnixConnector($loop);
$connector = new Connector($loop, array(
'tcp' => $tcp,
'tls' => $tls,
'unix' => $unix,
'dns' => false,
'timeout' => false,
));
$connector->connect('google.com:80')->then(function (ConnectionInterface $connection) {
$connection->write('...');
$connection->end();
});
Internally, the
tcp://
connector will always be wrapped by the DNS resolver, unless you disable DNS like in the above example. In this case, thetcp://
connector receives the actual hostname instead of only the resolved IP address and is thus responsible for performing the lookup. Internally, the automatically createdtls://
connector will always wrap the underlyingtcp://
connector for establishing the underlying plaintext TCP/IP connection before enabling secure TLS mode. If you want to use a custom underlyingtcp://
connector for secure TLS connections only, you may explicitly pass atls://
connector like above instead. Internally, thetcp://
andtls://
connectors will always be wrapped byTimeoutConnector
, unless you disable timeouts like in the above example.
The React\Socket\TcpConnector
class implements the
ConnectorInterface
and allows you to create plaintext
TCP/IP connections to any IP-port-combination:
$tcpConnector = new React\Socket\TcpConnector($loop);
$tcpConnector->connect('127.0.0.1:80')->then(function (ConnectionInterface $connection) {
$connection->write('...');
$connection->end();
});
$loop->run();
See also the first example.
Pending connection attempts can be cancelled by cancelling its pending promise like so:
$promise = $tcpConnector->connect('127.0.0.1:80');
$promise->cancel();
Calling cancel()
on a pending promise will close the underlying socket
resource, thus cancelling the pending TCP/IP connection, and reject the
resulting promise.
You can optionally pass additional socket context options to the constructor like this:
$tcpConnector = new React\Socket\TcpConnector($loop, array(
'bindto' => '192.168.0.1:0'
));
Note that this class only allows you to connect to IP-port-combinations.
If the given URI is invalid, does not contain a valid IP address and port
or contains any other scheme, it will reject with an
InvalidArgumentException
:
If the given URI appears to be valid, but connecting to it fails (such as if
the remote host rejects the connection etc.), it will reject with a
RuntimeException
.
If you want to connect to hostname-port-combinations, see also the following chapter.
Advanced usage: Internally, the
TcpConnector
allocates an empty context resource for each stream resource. If the destination URI contains ahostname
query parameter, its value will be used to set up the TLS peer name. This is used by theSecureConnector
andDnsConnector
to verify the peer name and can also be used if you want a custom TLS peer name.
The DnsConnector
class implements the
ConnectorInterface
and allows you to create plaintext
TCP/IP connections to any hostname-port-combination.
It does so by decorating a given TcpConnector
instance so that it first
looks up the given domain name via DNS (if applicable) and then establishes the
underlying TCP/IP connection to the resolved target IP address.
Make sure to set up your DNS resolver and underlying TCP connector like this:
$dnsResolverFactory = new React\Dns\Resolver\Factory();
$dns = $dnsResolverFactory->createCached('8.8.8.8', $loop);
$dnsConnector = new React\Socket\DnsConnector($tcpConnector, $dns);
$dnsConnector->connect('www.google.com:80')->then(function (ConnectionInterface $connection) {
$connection->write('...');
$connection->end();
});
$loop->run();
See also the first example.
Pending connection attempts can be cancelled by cancelling its pending promise like so:
$promise = $dnsConnector->connect('www.google.com:80');
$promise->cancel();
Calling cancel()
on a pending promise will cancel the underlying DNS lookup
and/or the underlying TCP/IP connection and reject the resulting promise.
Advanced usage: Internally, the
DnsConnector
relies on aResolver
to look up the IP address for the given hostname. It will then replace the hostname in the destination URI with this IP and append ahostname
query parameter and pass this updated URI to the underlying connector. The underlying connector is thus responsible for creating a connection to the target IP address, while this query parameter can be used to check the original hostname and is used by theTcpConnector
to set up the TLS peer name. If ahostname
is given explicitly, this query parameter will not be modified, which can be useful if you want a custom TLS peer name.
The SecureConnector
class implements the
ConnectorInterface
and allows you to create secure
TLS (formerly known as SSL) connections to any hostname-port-combination.
It does so by decorating a given DnsConnector
instance so that it first
creates a plaintext TCP/IP connection and then enables TLS encryption on this
stream.
$secureConnector = new React\Socket\SecureConnector($dnsConnector, $loop);
$secureConnector->connect('www.google.com:443')->then(function (ConnectionInterface $connection) {
$connection->write("GET / HTTP/1.0\r\nHost: www.google.com\r\n\r\n");
...
});
$loop->run();
See also the second example.
Pending connection attempts can be cancelled by cancelling its pending promise like so:
$promise = $secureConnector->connect('www.google.com:443');
$promise->cancel();
Calling cancel()
on a pending promise will cancel the underlying TCP/IP
connection and/or the SSL/TLS negonation and reject the resulting promise.
You can optionally pass additional SSL context options to the constructor like this:
$secureConnector = new React\Socket\SecureConnector($dnsConnector, $loop, array(
'verify_peer' => false,
'verify_peer_name' => false
));
Advanced usage: Internally, the
SecureConnector
relies on setting up the required context options on the underlying stream resource. It should therefor be used with aTcpConnector
somewhere in the connector stack so that it can allocate an empty context resource for each stream resource and verify the peer name. Failing to do so may result in a TLS peer name mismatch error or some hard to trace race conditions, because all stream resources will use a single, shared default context resource otherwise.
The TimeoutConnector
class implements the
ConnectorInterface
and allows you to add timeout
handling to any existing connector instance.
It does so by decorating any given ConnectorInterface
instance and starting a timer that will automatically reject and abort any
underlying connection attempt if it takes too long.
$timeoutConnector = new React\Socket\TimeoutConnector($connector, 3.0, $loop);
$timeoutConnector->connect('google.com:80')->then(function (ConnectionInterface $connection) {
// connection succeeded within 3.0 seconds
});
See also any of the examples.
Pending connection attempts can be cancelled by cancelling its pending promise like so:
$promise = $timeoutConnector->connect('google.com:80');
$promise->cancel();
Calling cancel()
on a pending promise will cancel the underlying connection
attempt, abort the timer and reject the resulting promise.
The UnixConnector
class implements the
ConnectorInterface
and allows you to connect to
Unix domain socket (UDS) paths like this:
$connector = new React\Socket\UnixConnector($loop);
$connector->connect('/tmp/demo.sock')->then(function (ConnectionInterface $connection) {
$connection->write("HELLO\n");
});
$loop->run();
Connecting to Unix domain sockets is an atomic operation, i.e. its promise will
settle (either resolve or reject) immediately.
As such, calling cancel()
on the resulting promise has no effect.
The
getRemoteAddress()
method will return the target Unix domain socket (UDS) path as given to theconnect()
method, prepended with theunix://
scheme, for exampleunix:///tmp/demo.sock
. ThegetLocalAddress()
method will most likely return anull
value as this value is not applicable to UDS connections here.
The recommended way to install this library is through Composer. New to Composer?
This will install the latest supported version:
$ composer require react/socket:^0.8
More details about version upgrades can be found in the CHANGELOG.
This project aims to run on any platform and thus does not require any PHP extensions and supports running on legacy PHP 5.3 through current PHP 7+ and HHVM. It's highly recommended to use PHP 7+ for this project, partly due to its vast performance improvements and partly because legacy PHP versions require several workarounds as described below.
Secure TLS connections received some major upgrades starting with PHP 5.6, with the defaults now being more secure, while older versions required explicit context options. This library does not take responsibility over these context options, so it's up to consumers of this library to take care of setting appropriate context options as described above.
All versions of PHP prior to 5.6.8 suffered from a buffering issue where reading
from a streaming TLS connection could be one data
event behind.
This library implements a work-around to try to flush the complete incoming
data buffers on these legacy PHP versions, which has a penalty of around 10% of
throughput on all connections.
With this work-around, we have not been able to reproduce this issue anymore,
but we have seen reports of people saying this could still affect some of the
older PHP versions (5.5.23
, 5.6.7
, and 5.6.8
).
Note that this only affects some higher-level streaming protocols, such as
IRC over TLS, but should not affect HTTP over TLS (HTTPS).
Further investigation of this issue is needed.
For more insights, this issue is also covered by our test suite.
This project also supports running on HHVM.
Note that really old HHVM < 3.8 does not support secure TLS connections, as it
lacks the required stream_socket_enable_crypto()
function.
As such, trying to create a secure TLS connections on affected versions will
return a rejected promise instead.
This issue is also covered by our test suite, which will skip related tests
on affected versions.
To run the test suite, you first need to clone this repo and then install all dependencies through Composer. Because the test suite contains some circular dependencies, you may have to manually specify the root package version like this:
$ COMPOSER_ROOT_VERSION=`git describe --abbrev=0` composer install
To run the test suite, go to the project root and run:
$ php vendor/bin/phpunit
MIT, see LICENSE file.