HardenedBSD/sys/netinet/sctp_crc32.c
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137 lines
4.3 KiB
C

/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 2001-2007, by Cisco Systems, Inc. All rights reserved.
* Copyright (c) 2008-2012, by Randall Stewart. All rights reserved.
* Copyright (c) 2008-2012, by Michael Tuexen. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* a) Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* b) 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.
*
* c) Neither the name of Cisco Systems, Inc. nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* 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 OWNER 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.
*/
#include <sys/cdefs.h>
#include "opt_sctp.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/gsb_crc32.h>
#include <sys/mbuf.h>
#include <netinet/sctp.h>
#include <netinet/sctp_crc32.h>
#if defined(SCTP) || defined(SCTP_SUPPORT)
#include <netinet/sctp_os.h>
#include <netinet/sctp_pcb.h>
#endif
static uint32_t
sctp_finalize_crc32c(uint32_t crc32c)
{
#if BYTE_ORDER == BIG_ENDIAN
uint32_t byte0, byte1, byte2, byte3;
#endif
#if BYTE_ORDER == BIG_ENDIAN
/*
* For BIG-ENDIAN platforms, the result is in LITTLE-ENDIAN byte
* order. For LITTLE-ENDIAN platforms, the result is in in
* BIG-ENDIAN byte order. So for BIG-ENDIAN platforms the bytes must
* be swapped to return the result always in network byte order (aka
* BIG-ENDIAN).
*/
byte0 = crc32c & 0x000000ff;
byte1 = (crc32c >> 8) & 0x000000ff;
byte2 = (crc32c >> 16) & 0x000000ff;
byte3 = (crc32c >> 24) & 0x000000ff;
crc32c = ((byte0 << 24) | (byte1 << 16) | (byte2 << 8) | byte3);
#endif
return (~crc32c);
}
static int
sctp_calculate_cksum_cb(void *arg, void *data, u_int len)
{
uint32_t *basep;
basep = arg;
*basep = calculate_crc32c(*basep, data, len);
return (0);
}
/*
* Compute the SCTP checksum in network byte order for a given mbuf chain m
* which contains an SCTP packet starting at offset.
* Since this function is also called by ipfw, don't assume that
* it is compiled on a kernel with SCTP support.
*/
uint32_t
sctp_calculate_cksum(struct mbuf *m, int32_t offset)
{
uint32_t base;
int len;
M_ASSERTPKTHDR(m);
KASSERT(offset < m->m_pkthdr.len,
("%s: invalid offset %u into mbuf %p", __func__, offset, m));
base = 0xffffffff;
len = m->m_pkthdr.len - offset;
(void)m_apply(m, offset, len, sctp_calculate_cksum_cb, &base);
return (sctp_finalize_crc32c(base));
}
#if defined(SCTP) || defined(SCTP_SUPPORT)
VNET_DEFINE(struct sctp_base_info, system_base_info);
/*
* Compute and insert the SCTP checksum in network byte order for a given
* mbuf chain m which contains an SCTP packet starting at offset.
*/
void
sctp_delayed_cksum(struct mbuf *m, uint32_t offset)
{
uint32_t checksum;
checksum = sctp_calculate_cksum(m, offset);
SCTP_STAT_DECR(sctps_sendhwcrc);
SCTP_STAT_INCR(sctps_sendswcrc);
offset += offsetof(struct sctphdr, checksum);
if (offset + sizeof(uint32_t) > (uint32_t)(m->m_pkthdr.len)) {
#ifdef INVARIANTS
panic("sctp_delayed_cksum(): m->m_pkthdr.len: %d, offset: %u.",
m->m_pkthdr.len, offset);
#else
SCTP_PRINTF("sctp_delayed_cksum(): m->m_pkthdr.len: %d, offset: %u.\n",
m->m_pkthdr.len, offset);
#endif
return;
}
m_copyback(m, (int)offset, (int)sizeof(uint32_t), (caddr_t)&checksum);
}
#endif