/*-
* 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>
__FBSDID("$FreeBSD$");
#include "opt_sctp.h"
#ifdef SCTP
#include <netinet/sctp_os.h>
#include <netinet/sctp.h>
#include <netinet/sctp_crc32.h>
#include <netinet/sctp_pcb.h>
#else
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mbuf.h>
#include <netinet/sctp_crc32.h>
#endif
static uint32_t
sctp_finalize_crc32c(uint32_t crc32c)
{
uint32_t result;
#if BYTE_ORDER == BIG_ENDIAN
uint8_t byte0, byte1, byte2, byte3;
#endif
/* Complement the result */
result = ~crc32c;
#if BYTE_ORDER == BIG_ENDIAN
/*
* For BIG-ENDIAN platforms the result is in little-endian form. So
* we must swap the bytes to return the result in network byte
* order.
*/
byte0 = result & 0x000000ff;
byte1 = (result >> 8) & 0x000000ff;
byte2 = (result >> 16) & 0x000000ff;
byte3 = (result >> 24) & 0x000000ff;
crc32c = ((byte0 << 24) | (byte1 << 16) | (byte2 << 8) | byte3);
#else
/*
* For LITTLE ENDIAN platforms the result is in already in network
* byte order.
*/
crc32c = result;
#endif
return (crc32c);
}
/*
* 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, uint32_t offset)
{
uint32_t base = 0xffffffff;
while (offset > 0) {
KASSERT(m != NULL, ("sctp_calculate_cksum, offset > length of mbuf chain"));
if (offset < (uint32_t)m->m_len) {
break;
}
offset -= m->m_len;
m = m->m_next;
}
if (offset > 0) {
base = calculate_crc32c(base,
(unsigned char *)(m->m_data + offset),
(unsigned int)(m->m_len - offset));
m = m->m_next;
}
while (m != NULL) {
base = calculate_crc32c(base,
(unsigned char *)m->m_data,
(unsigned int)m->m_len);
m = m->m_next;
}
base = sctp_finalize_crc32c(base);
return (base);
}
#ifdef SCTP
/*
* 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_len)) {
#ifdef INVARIANTS
panic("sctp_delayed_cksum(): m->m_len: %d, offset: %u.",
m->m_len, offset);
#else
SCTP_PRINTF("sctp_delayed_cksum(): m->m_len: %d, offset: %u.\n",
m->m_len, offset);
#endif
return;
}
*(uint32_t *)(m->m_data + offset) = checksum;
}
#endif
