1<html><head><meta http-equiv="Content-Type" content="text/html; charset=ANSI_X3.4-1968"><title>pskb_expand_head</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---pskb-copy-fclone.html" title="__pskb_copy_fclone"><link rel="next" href="API-skb-copy-expand.html" title="skb_copy_expand"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center"><span class="phrase">pskb_expand_head</span></th></tr><tr><td width="20%" align="left"><a accesskey="p" href="API---pskb-copy-fclone.html">Prev</a>&#160;</td><th width="60%" align="center">Socket Buffer Functions</th><td width="20%" align="right">&#160;<a accesskey="n" href="API-skb-copy-expand.html">Next</a></td></tr></table><hr></div><div class="refentry"><a name="API-pskb-expand-head"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>pskb_expand_head &#8212; 
2     reallocate header of <span class="structname">sk_buff</span>
3 </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">int <b class="fsfunc">pskb_expand_head </b>(</code></td><td>struct sk_buff * <var class="pdparam">skb</var>, </td></tr><tr><td>&#160;</td><td>int <var class="pdparam">nhead</var>, </td></tr><tr><td>&#160;</td><td>int <var class="pdparam">ntail</var>, </td></tr><tr><td>&#160;</td><td>gfp_t <var class="pdparam">gfp_mask</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer">&#160;</div></div></div><div class="refsect1"><a name="idp1096106500"></a><h2>Arguments</h2><div class="variablelist"><dl class="variablelist"><dt><span class="term"><em class="parameter"><code>skb</code></em></span></dt><dd><p>
4     buffer to reallocate
5    </p></dd><dt><span class="term"><em class="parameter"><code>nhead</code></em></span></dt><dd><p>
6     room to add at head
7    </p></dd><dt><span class="term"><em class="parameter"><code>ntail</code></em></span></dt><dd><p>
8     room to add at tail
9    </p></dd><dt><span class="term"><em class="parameter"><code>gfp_mask</code></em></span></dt><dd><p>
10     allocation priority
11    </p></dd></dl></div></div><div class="refsect1"><a name="idp1096111172"></a><h2>Description</h2><p>
12   Expands (or creates identical copy, if <em class="parameter"><code>nhead</code></em> and <em class="parameter"><code>ntail</code></em> are zero)
13   header of <em class="parameter"><code>skb</code></em>. <span class="structname">sk_buff</span> itself is not changed. <span class="structname">sk_buff</span> MUST have
14   reference count of 1. Returns zero in the case of success or error,
15   if expansion failed. In the last case, <span class="structname">sk_buff</span> is not changed.
16   </p><p>
17
18   All the pointers pointing into skb header may change and must be
19   reloaded after call to this function.
20</p></div></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="API---pskb-copy-fclone.html">Prev</a>&#160;</td><td width="20%" align="center"><a accesskey="u" href="ch01s02.html">Up</a></td><td width="40%" align="right">&#160;<a accesskey="n" href="API-skb-copy-expand.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top"><span class="phrase">__pskb_copy_fclone</span>&#160;</td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top">&#160;<span class="phrase">skb_copy_expand</span></td></tr></table></div></body></html>
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