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<h1 class="lined-header"><span>ranch_transport(3)</span></h1>
<h2 id="_name">Name</h2>
<p>ranch_transport - Transport modules</p>
<h2 id="_description">Description</h2>
<p>The module <code>ranch_transport</code> defines the interface used by Ranch transports.</p>
<h2 id="_callbacks">Callbacks</h2>
<p>Ranch transports implement the following interface:</p>
<h3 id="_accept">accept</h3>
<div class="listingblock"><div class="content"><!-- Generator: GNU source-highlight 3.1.9
by Lorenzo Bettini
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<pre><tt><b><font color="#000000">accept</font></b>(<font color="#009900">LSocket</font> <font color="#990000">::</font> <b><font color="#000000">socket</font></b>(), <font color="#009900">Timeout</font> <font color="#990000">::</font> <b><font color="#000000">timeout</font></b>())
<font color="#990000">-></font> {<font color="#FF6600">ok</font>, <font color="#009900">Socket</font> <font color="#990000">::</font> <b><font color="#000000">socket</font></b>()}
| {<font color="#FF6600">error</font>, <font color="#FF6600">closed</font> | <font color="#FF6600">timeout</font> | <b><font color="#000080">atom</font></b>()}</tt></pre>
</div></div>
<p>Use the listening socket returned by <code>listen/1</code> to accept a new connection. The timeout is specified in milliseconds.</p>
<h3 id="_close">close</h3>
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<pre><tt><b><font color="#000000">close</font></b>(<font color="#009900">Socket</font> <font color="#990000">::</font> <b><font color="#000000">socket</font></b>()) <font color="#990000">-></font> <font color="#FF6600">ok</font></tt></pre>
</div></div>
<p>Close the socket.</p>
<h3 id="_controlling_process">controlling_process</h3>
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<pre><tt><b><font color="#000000">controlling_process</font></b>(<font color="#009900">Socket</font> <font color="#990000">::</font> <b><font color="#000000">socket</font></b>(), <font color="#009900">Pid</font> <font color="#990000">::</font> <b><font color="#000080">pid</font></b>())
<font color="#990000">-></font> <font color="#FF6600">ok</font> | {<font color="#FF6600">error</font>, <font color="#FF6600">closed</font> | <font color="#FF6600">not_owner</font> | <b><font color="#000080">atom</font></b>()}</tt></pre>
</div></div>
<p>Assign a new controlling process to the socket. The controlling process is the process that is linked to and receives messages from the socket.</p>
<h3 id="_getopts">getopts</h3>
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by Lorenzo Bettini
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<pre><tt><b><font color="#000000">getopts</font></b>(<font color="#009900">Socket</font> <font color="#990000">::</font> <b><font color="#000000">socket</font></b>(), <font color="#009900">SockOpts</font> <font color="#990000">::</font> [<b><font color="#000080">atom</font></b>()])
<font color="#990000">-></font> {<font color="#FF6600">ok</font>, <b><font color="#000000">any</font></b>()} | {<font color="#FF6600">error</font>, <b><font color="#000080">atom</font></b>()}</tt></pre>
</div></div>
<p>Get one or more options for the socket.</p>
<h3 id="_getstat">getstat</h3>
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by Lorenzo Bettini
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<pre><tt><b><font color="#000000">getstat</font></b>(<font color="#009900">Socket</font> <font color="#990000">::</font> <b><font color="#000000">socket</font></b>())
<font color="#990000">-></font> {<font color="#FF6600">ok</font>, <font color="#009900">SockStatValues</font> <font color="#990000">::</font> <b><font color="#000000">any</font></b>()} | {<font color="#FF6600">error</font>, <b><font color="#000080">atom</font></b>()}</tt></pre>
</div></div>
<p>Get all statistics for the socket.</p>
<div class="listingblock"><div class="content"><!-- Generator: GNU source-highlight 3.1.9
by Lorenzo Bettini
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<pre><tt><b><font color="#000000">getstat</font></b>(<font color="#009900">Socket</font> <font color="#990000">::</font> <b><font color="#000000">socket</font></b>(), <font color="#009900">SockStats</font> <font color="#990000">::</font> [<b><font color="#000080">atom</font></b>()])
<font color="#990000">-></font> {<font color="#FF6600">ok</font>, <font color="#009900">SockStatValues</font> <font color="#990000">::</font> <b><font color="#000000">any</font></b>()} | {<font color="#FF6600">error</font>, <b><font color="#000080">atom</font></b>()}</tt></pre>
</div></div>
<p>Get one or more statistic options for the socket.</p>
<h3 id="_handshake">handshake</h3>
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by Lorenzo Bettini
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<pre><tt><b><font color="#000000">handshake</font></b>(<font color="#009900">Socket0</font> <font color="#990000">::</font> <b><font color="#000000">socket</font></b>(),
<font color="#009900">SockOpts</font> <font color="#990000">::</font> <b><font color="#000000">any</font></b>(),
<font color="#009900">Timeout</font> <font color="#990000">::</font> <b><font color="#000000">timeout</font></b>())
<font color="#990000">-></font> {<font color="#FF6600">ok</font>, <font color="#009900">Socket</font>}</tt></pre>
</div></div>
<p>Perform the transport-level handshake.</p>
<p>This function will be called by connection processes before performing any socket operation. It allows transports that require extra initialization to perform their task and return a socket that is ready to use.</p>
<p>This function may also be used to upgrade a connection from a transport to another depending on the capabilities of the transports. For example a <code>ranch_tcp</code> socket may be upgraded to a <code>ranch_ssl</code> one using this function.</p>
<h3 id="_listen">listen</h3>
<div class="listingblock"><div class="content"><!-- Generator: GNU source-highlight 3.1.9
by Lorenzo Bettini
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<pre><tt><b><font color="#000000">listen</font></b>(<font color="#009900">SockOpts</font> <font color="#990000">::</font> <b><font color="#000000">any</font></b>())
<font color="#990000">-></font> {<font color="#FF6600">ok</font>, <font color="#009900">LSocket</font> <font color="#990000">::</font> <b><font color="#000000">socket</font></b>()} | {<font color="#FF6600">error</font>, <b><font color="#000080">atom</font></b>()}</tt></pre>
</div></div>
<p>Create a socket that listens on the given port.</p>
<p>The port may not be specified or may be set to 0, which means a random available port number will be chosen.</p>
<h3 id="_messages">messages</h3>
<div class="listingblock"><div class="content"><!-- Generator: GNU source-highlight 3.1.9
by Lorenzo Bettini
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<pre><tt><b><font color="#000000">messages</font></b>()
<font color="#990000">-></font> {<font color="#009900">OK</font> <font color="#990000">::</font> <b><font color="#000080">atom</font></b>(),
<font color="#009900">Closed</font> <font color="#990000">::</font> <b><font color="#000080">atom</font></b>(),
<font color="#009900">Error</font> <font color="#990000">::</font> <b><font color="#000080">atom</font></b>()}</tt></pre>
</div></div>
<p>Return the tuple keys for the messages sent by the socket.</p>
<h3 id="_name">name</h3>
<div class="listingblock"><div class="content"><!-- Generator: GNU source-highlight 3.1.9
by Lorenzo Bettini
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<pre><tt><b><font color="#000080">name</font></b>() <font color="#990000">-></font> <font color="#009900">Name</font> <font color="#990000">::</font> <b><font color="#000080">atom</font></b>()</tt></pre>
</div></div>
<p>Return the name of the transport.</p>
<h3 id="_peername">peername</h3>
<div class="listingblock"><div class="content"><!-- Generator: GNU source-highlight 3.1.9
by Lorenzo Bettini
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<pre><tt><b><font color="#000000">peername</font></b>(<font color="#009900">Socket</font> <font color="#990000">::</font> <b><font color="#000000">socket</font></b>())
<font color="#990000">-></font> {<font color="#FF6600">ok</font>, {<b><font color="#000000">inet:ip_address</font></b>(), <b><font color="#000000">inet:port_number</font></b>()}}
| {<font color="#FF6600">error</font>, <b><font color="#000080">atom</font></b>()}<font color="#990000">.</font></tt></pre>
</div></div>
<p>Return the address and port number for the other end of the connection.</p>
<h3 id="_recv">recv</h3>
<div class="listingblock"><div class="content"><!-- Generator: GNU source-highlight 3.1.9
by Lorenzo Bettini
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<pre><tt><b><font color="#000000">recv</font></b>(<font color="#009900">Socket</font> <font color="#990000">::</font> <b><font color="#000000">socket</font></b>(),
<font color="#009900">Length</font> <font color="#990000">::</font> <b><font color="#000000">non_neg_integer</font></b>(),
<font color="#009900">Timeout</font> <font color="#990000">::</font> <b><font color="#000000">timeout</font></b>())
<font color="#990000">-></font> {<font color="#FF6600">ok</font>, <font color="#009900">Packet</font> <font color="#990000">::</font> <b><font color="#000000">any</font></b>()}
| {<font color="#FF6600">error</font>, <font color="#FF6600">closed</font> | <font color="#FF6600">timeout</font> | <b><font color="#000080">atom</font></b>()}</tt></pre>
</div></div>
<p>Receive a packet from the socket in passive mode.</p>
<p>Attempting to receive data from a socket that is in active mode will return an error.</p>
<p>A length of 0 will return the data available on the socket as soon as possible, regardless of length.</p>
<p>While it is possible to use the timeout value <code>infinity</code>, it is highly discouraged as it could cause your process to get stuck waiting for data that will never come. This may happen when a socket becomes half-open due to a crash of the remote endpoint. Wi-Fi going down is another common culprit.</p>
<h3 id="_secure">secure</h3>
<div class="listingblock"><div class="content"><!-- Generator: GNU source-highlight 3.1.9
by Lorenzo Bettini
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<pre><tt><b><font color="#000000">secure</font></b>() <font color="#990000">-></font> <b><font color="#000000">boolean</font></b>()</tt></pre>
</div></div>
<p>Return whether the transport can be used for secure connections.</p>
<h3 id="_send">send</h3>
<div class="listingblock"><div class="content"><!-- Generator: GNU source-highlight 3.1.9
by Lorenzo Bettini
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<pre><tt><b><font color="#000000">send</font></b>(<font color="#009900">Socket</font> <font color="#990000">::</font> <b><font color="#000000">socket</font></b>(), <font color="#009900">Packet</font> <font color="#990000">::</font> <b><font color="#000000">iodata</font></b>())
<font color="#990000">-></font> <font color="#FF6600">ok</font> | {<font color="#FF6600">error</font>, <b><font color="#000080">atom</font></b>()}</tt></pre>
</div></div>
<p>Send a packet on the socket.</p>
<h3 id="_sendfile">sendfile</h3>
<div class="listingblock"><div class="content"><!-- Generator: GNU source-highlight 3.1.9
by Lorenzo Bettini
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<pre><tt><b><font color="#000000">sendfile</font></b>(<font color="#009900">Socket</font>, <font color="#009900">File</font>)
<font color="#990000">-></font> <b><font color="#000000">sendfile</font></b>(<font color="#009900">Socket</font>, <font color="#009900">File</font>, <font color="#993399">0</font>, <font color="#993399">0</font>, [])
<b><font color="#000000">sendfile</font></b>(<font color="#009900">Socket</font>, <font color="#009900">File</font>, <font color="#009900">Offset</font>, <font color="#009900">Bytes</font>)
<font color="#990000">-></font> <b><font color="#000000">sendfile</font></b>(<font color="#009900">Socket</font>, <font color="#009900">File</font>, <font color="#009900">Offset</font>, <font color="#009900">Bytes</font>, [])
<b><font color="#000000">sendfile</font></b>(<font color="#009900">Socket</font> <font color="#990000">::</font> <b><font color="#000000">socket</font></b>(),
<font color="#009900">File</font> <font color="#990000">::</font> <b><font color="#000000">file:name_all</font></b>() | <b><font color="#000000">file:fd</font></b>(),
<font color="#009900">Offset</font> <font color="#990000">::</font> <b><font color="#000000">non_neg_integer</font></b>(),
<font color="#009900">Bytes</font> <font color="#990000">::</font> <b><font color="#000000">non_neg_integer</font></b>(),
<font color="#009900">Opts</font> <font color="#990000">::</font> <b><font color="#000000">sendfile_opts</font></b>())
<font color="#990000">-></font> {<font color="#FF6600">ok</font>, <font color="#009900">SentBytes</font> <font color="#990000">::</font> <b><font color="#000000">non_neg_integer</font></b>()} | {<font color="#FF6600">error</font>, <b><font color="#000080">atom</font></b>()}</tt></pre>
</div></div>
<p>Send a file on the socket.</p>
<p>The file may be sent full or in parts, and may be specified by its filename or by an already open file descriptor.</p>
<p>Transports that manipulate TCP directly may use the <code>file:sendfile/2,4,5</code> function, which calls the <code>sendfile</code> syscall where applicable (on Linux, for example). Other transports can use the <code>sendfile/6</code> function exported from this module.</p>
<h3 id="_setopts">setopts</h3>
<div class="listingblock"><div class="content"><!-- Generator: GNU source-highlight 3.1.9
by Lorenzo Bettini
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<pre><tt><b><font color="#000000">setopts</font></b>(<font color="#009900">Socket</font> <font color="#990000">::</font> <b><font color="#000000">socket</font></b>(), <font color="#009900">SockOpts</font> <font color="#990000">::</font> <b><font color="#000000">any</font></b>())
<font color="#990000">-></font> <font color="#FF6600">ok</font> | {<font color="#FF6600">error</font>, <b><font color="#000080">atom</font></b>()}</tt></pre>
</div></div>
<p>Set one or more options for the socket.</p>
<h3 id="_shutdown">shutdown</h3>
<div class="listingblock"><div class="content"><!-- Generator: GNU source-highlight 3.1.9
by Lorenzo Bettini
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<pre><tt><font color="#000080">shutdown</font>(<font color="#009900">Socket</font> <font color="#990000">::</font> <b><font color="#000000">socket</font></b>(),
<font color="#009900">How</font> <font color="#990000">::</font> <font color="#FF6600">read</font> | <font color="#FF6600">write</font> | <font color="#FF6600">read_write</font>)
<font color="#990000">-></font> <font color="#FF6600">ok</font> | {<font color="#FF6600">error</font>, <b><font color="#000080">atom</font></b>()}</tt></pre>
</div></div>
<p>Close the socket for reading and/or writing.</p>
<h3 id="_sockname">sockname</h3>
<div class="listingblock"><div class="content"><!-- Generator: GNU source-highlight 3.1.9
by Lorenzo Bettini
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<pre><tt><b><font color="#000000">sockname</font></b>(<font color="#009900">Socket</font> <font color="#990000">::</font> <b><font color="#000000">socket</font></b>())
<font color="#990000">-></font> {<font color="#FF6600">ok</font>, {<b><font color="#000000">inet:ip_address</font></b>(), <b><font color="#000000">inet:port_number</font></b>()}}
| {<font color="#FF6600">error</font>, <b><font color="#000080">atom</font></b>()}<font color="#990000">.</font></tt></pre>
</div></div>
<p>Return the address and port number for the local end of the connection.</p>
<h2 id="_exports">Exports</h2>
<p>The following function can be used when implementing transport modules:</p>
<ul><li><a href="../ranch_transport.sendfile">ranch_transport:sendfile(3)</a> - Send a file on the socket
</li>
</ul>
<h2 id="_types">Types</h2>
<h3 id="_sendfile_opts">sendfile_opts()</h3>
<div class="listingblock"><div class="content"><!-- Generator: GNU source-highlight 3.1.9
by Lorenzo Bettini
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<pre><tt><b><font color="#000000">sendfile_opts</font></b>() <font color="#990000">::</font> [{<font color="#FF6600">chunk_size</font>, <b><font color="#000000">non_neg_integer</font></b>()}]</tt></pre>
</div></div>
<p>Options accepted by the sendfile function and callbacks:</p>
<dl><dt>chunk_size (8191)</dt>
<dd><p>The chunk size, in bytes.</p>
</dd>
</dl>
<h3 id="_socket">socket()</h3>
<div class="listingblock"><div class="content"><!-- Generator: GNU source-highlight 3.1.9
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<pre><tt><b><font color="#000000">socket</font></b>() <font color="#990000">::</font> <b><font color="#000000">any</font></b>()</tt></pre>
</div></div>
<p>The socket.</p>
<p>The exact type will vary depending on the transport module.</p>
<h2 id="_changelog">Changelog</h2>
<ul><li><strong>1.6</strong>: The <code>socket()</code> type was added for documentation purposes.
</li>
<li><strong>1.6</strong>: The type of the sendfile filename was extended.
</li>
</ul>
<h2 id="_see_also">See also</h2>
<p><a href="..">ranch(7)</a>, <a href="../ranch_tcp">ranch_tcp(3)</a>, <a href="../ranch_ssl">ranch_ssl(3)</a></p>
</div>
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Function Reference
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