# clue/socket-raw

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Simple and lightweight OOP wrapper for PHP's low-level sockets extension (ext-sockets).

PHP offers two networking APIs, the newer [streams API](https://www.php.net/manual/en/book.stream.php) and the older [socket API](https://www.php.net/manual/en/ref.sockets.php).
While the former has been a huge step forward in generalizing various streaming resources,
it lacks some of the advanced features of the original and much more low-level socket API.
This lightweight library exposes this socket API in a modern way by providing a thin wrapper around the underlying API.

* **Full socket API** -
  It exposes the whole [socket API](https://www.php.net/manual/en/ref.sockets.php) through a *sane* object-oriented interface.
  Provides convenience methods for common operations as well as exposing all underlying methods and options.
* **Fluent interface** -
  Uses a fluent interface so you can easily chain method calls.
  Error conditions will be signalled using `Exception`s instead of relying on cumbersome return codes.
* **Lightweight, SOLID design** -
  Provides a thin abstraction that is [*just good enough*](https://en.wikipedia.org/wiki/Principle_of_good_enough)
  and does not get in your way.
  This library is merely a very thin wrapper and has no other external dependencies.
* **Good test coverage** -
  Comes with an automated test suite and is regularly tested in the *real world*.

**Table of contents**

* [Support us](#support-us)
* [Quickstart example](#quickstart-example)
* [Usage](#usage)
  * [Factory](#factory)
    * [createClient()](#createclient)
    * [createServer()](#createserver)
    * [create*()](#create)
  * [Socket](#socket)
    * [Methods](#methods)
      * [Data I/O](#data-io)
      * [Unconnected I/O](#unconnected-io)
      * [Non-blocking (async) I/O](#non-blocking-async-io)
      * [Connection handling](#connection-handling)
* [Install](#install)
* [Tests](#tests)
* [License](#license)

## Support us

We invest a lot of time developing, maintaining and updating our awesome
open-source projects. You can help us sustain this high-quality of our work by
[becoming a sponsor on GitHub](https://github.com/sponsors/clue). Sponsors get
numerous benefits in return, see our [sponsoring page](https://github.com/sponsors/clue)
for details.

Let's take these projects to the next level together! 🚀

## Quickstart example

Once [installed](#install), you can use the following example to send and receive HTTP messages:

```php
$factory = new \Socket\Raw\Factory();

$socket = $factory->createClient('www.google.com:80');
echo 'Connected to ' . $socket->getPeerName() . PHP_EOL;

// send simple HTTP request to remote side
$socket->write("GET / HTTP/1.1\r\n\Host: www.google.com\r\n\r\n");

// receive and dump HTTP response
var_dump($socket->read(8192));

$socket->close();
```

See also the [examples](examples).

## Usage

### Factory

As shown in the [quickstart example](#quickstart-example), this library uses a `Factory` pattern
as a simple API to [`socket_create()`](https://www.php.net/manual/en/function.socket-create.php).
It provides simple access to creating TCP, UDP, UNIX, UDG and ICMP protocol sockets and supports both IPv4 and IPv6 addressing.

```php
$factory = new \Socket\Raw\Factory();
```

#### createClient()

The `createClient(string $address, null|float $timeout): Socket` method is
the most convenient method for creating connected client sockets
(similar to how [`fsockopen()`](https://www.php.net/manual/en/function.fsockopen.php) or
[`stream_socket_client()`](https://www.php.net/manual/en/function.stream-socket-client.php) work).

```php
// establish a TCP/IP stream connection socket to www.google.com on port 80
$socket = $factory->createClient('tcp://www.google.com:80');

// same as above, as scheme defaults to TCP
$socket = $factory->createClient('www.google.com:80');

// same as above, but wait no longer than 2.5s for connection
$socket = $factory->createClient('www.google.com:80', 2.5);

// create connectionless UDP/IP datagram socket connected to google's DNS
$socket = $factory->createClient('udp://8.8.8.8:53');

// establish TCP/IPv6 stream connection socket to localhost on port 1337
$socket = $factory->createClient('tcp://[::1]:1337');

// connect to local Unix stream socket path
$socket = $factory->createClient('unix:///tmp/daemon.sock');

// create Unix datagram socket
$socket = $factory->createClient('udg:///tmp/udg.socket');

// create a raw low-level ICMP socket (requires root!)
$socket = $factory->createClient('icmp://192.168.0.1');
```

#### createServer()

The `createServer($address)` method can be used to create a server side (listening) socket bound to specific address/path
(similar to how [`stream_socket_server()`](https://www.php.net/manual/en/function.stream-socket-server.php) works).
It accepts the same addressing scheme as the [`createClient()`](#createclient) method.

```php
// create a TCP/IP stream connection socket server on port 1337
$socket = $factory->createServer('tcp://localhost:1337');

// create a UDP/IPv6 datagram socket server on port 1337
$socket = $factory->createServer('udp://[::1]:1337');
```

#### create*()

Less commonly used, the `Factory` provides access to creating (unconnected) sockets for various socket types:

```php
$socket = $factory->createTcp4();
$socket = $factory->createTcp6();

$socket = $factory->createUdp4();
$socket = $factory->createUdp6();

$socket = $factory->createUnix();
$socket = $factory->createUdg();

$socket = $factory->createIcmp4();
$socket = $factory->createIcmp6();
```

You can also create arbitrary socket protocol types through the underlying mechanism:

```php
$factory->create($family, $type, $protocol);
```

### Socket

As discussed above, the `Socket` class is merely an object-oriented wrapper around a socket resource. As such, it helps if you're familar with socket programming in general.

The recommended way to create a `Socket` instance is via the above [`Factory`](#factory).

#### Methods

All low-level socket operations are available as methods on the `Socket` class.

You can refer to PHP's fairly good [socket API documentation](https://www.php.net/manual/en/ref.sockets.php) or the docblock comments in the [`Socket` class](src/Socket.php) to get you started.

##### Data I/O:

```
$socket->write('data');
$data = $socket->read(8192);
```

##### Unconnected I/O:

```
$socket->sendTo('data', $flags, $remote);
$data = $socket->rcvFrom(8192, $flags, $remote);
```

##### Non-blocking (async) I/O:

```
$socket->setBlocking(false);
$socket->selectRead();
$socket->selectWrite();
```

##### Connection handling:

```php
$client = $socket->accept();
$socket->bind($address);
$socket->connect($address);
$socket->shutdown();
$socket->close();
```

## Install

The recommended way to install this library is [through Composer](https://getcomposer.org/).
[New to Composer?](https://getcomposer.org/doc/00-intro.md)

This project follows [SemVer](https://semver.org/).
This will install the latest supported version:

```bash
$ composer require clue/socket-raw:^1.6
```

See also the [CHANGELOG](CHANGELOG.md) for details about version upgrades.

This project aims to run on any platform and thus does not require any PHP
extensions besides `ext-sockets` and supports running on legacy PHP 5.3 through
current PHP 8+.
It's *highly recommended to use the latest supported PHP version* for this project.

## Tests

To run the test suite, you first need to clone this repo and then install all
dependencies [through Composer](https://getcomposer.org/):

```bash
$ composer install
```

To run the test suite, go to the project root and run:

```bash
$ vendor/bin/phpunit
```

Note that the test suite contains tests for ICMP sockets which require root
access on Unix/Linux systems. Therefor some tests will be skipped unless you run
the following command to execute the full test suite:

```bash
$ sudo vendor/bin/phpunit
```

The test suite also contains a number of functional integration tests that rely
on a stable internet connection.
If you do not want to run these, they can simply be skipped like this:

```bash
$ vendor/bin/phpunit --exclude-group internet
```

## License

This project is released under the permissive [MIT license](LICENSE).

> Did you know that I offer custom development services and issuing invoices for
  sponsorships of releases and for contributions? Contact me (@clue) for details.
