diff --git a/sys/netinet/sctp_crc32.c b/sys/netinet/sctp_crc32.c index 97b881bb5062..9e17637d74d6 100644 --- a/sys/netinet/sctp_crc32.c +++ b/sys/netinet/sctp_crc32.c @@ -1,145 +1,138 @@ /*- * 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 __FBSDID("$FreeBSD$"); #include "opt_sctp.h" #include #include #include #include #include #include #if defined(SCTP) || defined(SCTP_SUPPORT) #include #include #endif static uint32_t sctp_finalize_crc32c(uint32_t crc32c) { - uint32_t result; #if BYTE_ORDER == BIG_ENDIAN - uint8_t byte0, byte1, byte2, byte3; + uint32_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. + * 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 = result & 0x000000ff; - byte1 = (result >> 8) & 0x000000ff; - byte2 = (result >> 16) & 0x000000ff; - byte3 = (result >> 24) & 0x000000ff; + byte0 = crc32c & 0x000000ff; + byte1 = (crc32c >> 8) & 0x000000ff; + byte2 = (crc32c >> 16) & 0x000000ff; + byte3 = (crc32c >> 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); + 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, uint32_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