'\" t .\" Title: pskb_expand_head .\" Author: [FIXME: author] [see http://docbook.sf.net/el/author] .\" Generator: DocBook XSL Stylesheets v1.79.1 .\" Date: January 2017 .\" Manual: Linux Networking .\" Source: Kernel Hackers Manual 4.8.15 .\" Language: English .\" .TH "PSKB_EXPAND_HEAD" "9" "January 2017" "Kernel Hackers Manual 4\&.8\&." "Linux Networking" .\" ----------------------------------------------------------------- .\" * Define some portability stuff .\" ----------------------------------------------------------------- .\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .\" http://bugs.debian.org/507673 .\" http://lists.gnu.org/archive/html/groff/2009-02/msg00013.html .\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .ie \n(.g .ds Aq \(aq .el .ds Aq ' .\" ----------------------------------------------------------------- .\" * set default formatting .\" ----------------------------------------------------------------- .\" disable hyphenation .nh .\" disable justification (adjust text to left margin only) .ad l .\" ----------------------------------------------------------------- .\" * MAIN CONTENT STARTS HERE * .\" ----------------------------------------------------------------- .SH "NAME" pskb_expand_head \- reallocate header of sk_buff .SH "SYNOPSIS" .HP \w'int\ pskb_expand_head('u .BI "int pskb_expand_head(struct\ sk_buff\ *\ " "skb" ", int\ " "nhead" ", int\ " "ntail" ", gfp_t\ " "gfp_mask" ");" .SH "ARGUMENTS" .PP \fIskb\fR .RS 4 buffer to reallocate .RE .PP \fInhead\fR .RS 4 room to add at head .RE .PP \fIntail\fR .RS 4 room to add at tail .RE .PP \fIgfp_mask\fR .RS 4 allocation priority .RE .SH "DESCRIPTION" .PP Expands (or creates identical copy, if \fInhead\fR and \fIntail\fR are zero) header of \fIskb\fR\&. sk_buff itself is not changed\&. sk_buff MUST have reference count of 1\&. Returns zero in the case of success or error, if expansion failed\&. In the last case, sk_buff is not changed\&. .PP All the pointers pointing into skb header may change and must be reloaded after call to this function\&. .SH "COPYRIGHT" .br