'\" t
.\"     Title: skb_checksum_complete
.\"    Author: [FIXME: author] [see http://docbook.sf.net/el/author]
.\" Generator: DocBook XSL Stylesheets v1.78.1 <http://docbook.sf.net/>
.\"      Date: May 2018
.\"    Manual: Linux Networking
.\"    Source: Kernel Hackers Manual 3.16.56
.\"  Language: English
.\"
.TH "SKB_CHECKSUM_COMPLET" "9" "May 2018" "Kernel Hackers Manual 3\&.16\&" "Linux Networking"
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.SH "NAME"
skb_checksum_complete \- Calculate checksum of an entire packet
.SH "SYNOPSIS"
.HP \w'__sum16\ skb_checksum_complete('u
.BI "__sum16 skb_checksum_complete(struct\ sk_buff\ *\ " "skb" ");"
.SH "ARGUMENTS"
.PP
\fIskb\fR
.RS 4
packet to process
.RE
.SH "DESCRIPTION"
.PP
This function calculates the checksum over the entire packet plus the value of skb\->csum\&. The latter can be used to supply the checksum of a pseudo header as used by TCP/UDP\&. It returns the checksum\&.
.PP
For protocols that contain complete checksums such as ICMP/TCP/UDP, this function can be used to verify that checksum on received packets\&. In that case the function should return zero if the checksum is correct\&. In particular, this function will return zero if skb\->ip_summed is CHECKSUM_UNNECESSARY which indicates that the hardware has already verified the correctness of the checksum\&.
.SH "COPYRIGHT"
.br