<?xml version="1.0" encoding="ANSI_X3.4-1968" standalone="no"?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=ANSI_X3.4-1968" /><title>__alloc_skb</title><meta name="generator" content="DocBook XSL Stylesheets V1.78.1" /><link rel="home" href="index.html" title="Linux Networking and Network Devices APIs" /><link rel="up" href="ch01s02.html" title="Socket Buffer Functions" /><link rel="prev" href="API-sock-unregister.html" title="sock_unregister" /><link rel="next" href="API-build-skb.html" title="build_skb" /></head><body><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center"><span class="phrase">__alloc_skb</span></th></tr><tr><td width="20%" align="left"><a accesskey="p" href="API-sock-unregister.html">Prev</a> </td><th width="60%" align="center">Socket Buffer Functions</th><td width="20%" align="right"> <a accesskey="n" href="API-build-skb.html">Next</a></td></tr></table><hr /></div><div class="refentry"><a id="API---alloc-skb"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>__alloc_skb — allocate a network buffer </p></div><div class="refsynopsisdiv"><h2>Synopsis</h2><div class="funcsynopsis"><table border="0" class="funcprototype-table" summary="Function synopsis" style="cellspacing: 0; cellpadding: 0;"><tr><td><code class="funcdef">struct sk_buff * <strong class="fsfunc">__alloc_skb </strong>(</code></td><td>unsigned int <var class="pdparam">size</var>, </td></tr><tr><td> </td><td>gfp_t <var class="pdparam">gfp_mask</var>, </td></tr><tr><td> </td><td>int <var class="pdparam">flags</var>, </td></tr><tr><td> </td><td>int <var class="pdparam">node</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer"> </div></div></div><div class="refsect1"><a id="idm140045380023152"></a><h2>Arguments</h2><div class="variablelist"><dl class="variablelist"><dt><span class="term"><em class="parameter"><code>size</code></em></span></dt><dd><p> size to allocate </p></dd><dt><span class="term"><em class="parameter"><code>gfp_mask</code></em></span></dt><dd><p> allocation mask </p></dd><dt><span class="term"><em class="parameter"><code>flags</code></em></span></dt><dd><p> If SKB_ALLOC_FCLONE is set, allocate from fclone cache instead of head cache and allocate a cloned (child) skb. If SKB_ALLOC_RX is set, __GFP_MEMALLOC will be used for allocations in case the data is required for writeback </p></dd><dt><span class="term"><em class="parameter"><code>node</code></em></span></dt><dd><p> numa node to allocate memory on </p></dd></dl></div></div><div class="refsect1"><a id="idm140045380014112"></a><h2>Description</h2><p> Allocate a new <span class="structname">sk_buff</span>. The returned buffer has no headroom and a tail room of at least size bytes. The object has a reference count of one. The return is the buffer. On a failure the return is <code class="constant">NULL</code>. </p><p> Buffers may only be allocated from interrupts using a <em class="parameter"><code>gfp_mask</code></em> of <code class="constant">GFP_ATOMIC</code>. </p></div></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="API-sock-unregister.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="ch01s02.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="API-build-skb.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top"><span class="phrase">sock_unregister</span> </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> <span class="phrase">build_skb</span></td></tr></table></div></body></html>