mirror of https://github.com/OISF/suricata
You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
61 lines
2.1 KiB
C
61 lines
2.1 KiB
C
/*
|
|
* Reference: OpenBSD's pf.c.
|
|
*
|
|
* Copyright (c) 2001 Daniel Hartmeier
|
|
* Copyright (c) 2002 - 2008 Henning Brauer
|
|
* All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
*
|
|
* - Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* - Redistributions in binary form must reproduce the above
|
|
* copyright notice, this list of conditions and the following
|
|
* disclaimer in the documentation and/or other materials provided
|
|
* with the distribution.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
|
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
|
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
|
|
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
|
|
* COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
|
|
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
|
|
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
|
|
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
|
|
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
|
|
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
|
* POSSIBILITY OF SUCH DAMAGE.
|
|
*
|
|
* Effort sponsored in part by the Defense Advanced Research Projects
|
|
* Agency (DARPA) and Air Force Research Laboratory, Air Force
|
|
* Materiel Command, USAF, under agreement number F30602-01-2-0537.
|
|
*/
|
|
|
|
#include <stdint.h>
|
|
|
|
#include "util-fix_checksum.h"
|
|
|
|
/**
|
|
* \brief Fix-up an IP checksum.
|
|
*
|
|
* \param sum The current checksum.
|
|
* \param old Value of old header parameter.
|
|
* \param new Value of new header parameter.
|
|
*
|
|
* \retval New checksum.
|
|
*/
|
|
uint16_t
|
|
FixChecksum(uint16_t sum, uint16_t old, uint16_t new)
|
|
{
|
|
uint32_t l;
|
|
|
|
l = sum + old - new;
|
|
l = (l >> 16) + (l & 65535);
|
|
l = l & 65535;
|
|
|
|
return l;
|
|
}
|