1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 2001-2007, by Cisco Systems, Inc. All rights reserved. 5 * Copyright (c) 2008-2012, by Randall Stewart. All rights reserved. 6 * Copyright (c) 2008-2012, by Michael Tuexen. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions are met: 10 * 11 * a) Redistributions of source code must retain the above copyright notice, 12 * this list of conditions and the following disclaimer. 13 * 14 * b) Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in 16 * the documentation and/or other materials provided with the distribution. 17 * 18 * c) Neither the name of Cisco Systems, Inc. nor the names of its 19 * contributors may be used to endorse or promote products derived 20 * from this software without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 23 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, 24 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE 26 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 27 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 28 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 29 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 30 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 31 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF 32 * THE POSSIBILITY OF SUCH DAMAGE. 33 */ 34 35 #include <sys/cdefs.h> 36 __FBSDID("$FreeBSD$"); 37 38 #include "opt_sctp.h" 39 40 #include <sys/param.h> 41 #include <sys/systm.h> 42 #include <sys/gsb_crc32.h> 43 #include <sys/mbuf.h> 44 45 #include <netinet/sctp.h> 46 #include <netinet/sctp_crc32.h> 47 #if defined(SCTP) || defined(SCTP_SUPPORT) 48 #include <netinet/sctp_os.h> 49 #include <netinet/sctp_pcb.h> 50 #endif 51 52 static uint32_t 53 sctp_finalize_crc32c(uint32_t crc32c) 54 { 55 #if BYTE_ORDER == BIG_ENDIAN 56 uint32_t byte0, byte1, byte2, byte3; 57 #endif 58 59 #if BYTE_ORDER == BIG_ENDIAN 60 /* 61 * For BIG-ENDIAN platforms, the result is in LITTLE-ENDIAN byte 62 * order. For LITTLE-ENDIAN platforms, the result is in in 63 * BIG-ENDIAN byte order. So for BIG-ENDIAN platforms the bytes must 64 * be swapped to return the result always in network byte order (aka 65 * BIG-ENDIAN). 66 */ 67 byte0 = crc32c & 0x000000ff; 68 byte1 = (crc32c >> 8) & 0x000000ff; 69 byte2 = (crc32c >> 16) & 0x000000ff; 70 byte3 = (crc32c >> 24) & 0x000000ff; 71 crc32c = ((byte0 << 24) | (byte1 << 16) | (byte2 << 8) | byte3); 72 #endif 73 return (~crc32c); 74 } 75 76 static int 77 sctp_calculate_cksum_cb(void *arg, void *data, u_int len) 78 { 79 uint32_t *basep; 80 81 basep = arg; 82 *basep = calculate_crc32c(*basep, data, len); 83 return (0); 84 } 85 86 /* 87 * Compute the SCTP checksum in network byte order for a given mbuf chain m 88 * which contains an SCTP packet starting at offset. 89 * Since this function is also called by ipfw, don't assume that 90 * it is compiled on a kernel with SCTP support. 91 */ 92 uint32_t 93 sctp_calculate_cksum(struct mbuf *m, int32_t offset) 94 { 95 uint32_t base; 96 int len; 97 98 M_ASSERTPKTHDR(m); 99 KASSERT(offset < m->m_pkthdr.len, 100 ("%s: invalid offset %u into mbuf %p", __func__, offset, m)); 101 102 base = 0xffffffff; 103 len = m->m_pkthdr.len - offset; 104 (void)m_apply(m, offset, len, sctp_calculate_cksum_cb, &base); 105 return (sctp_finalize_crc32c(base)); 106 } 107 108 #if defined(SCTP) || defined(SCTP_SUPPORT) 109 110 VNET_DEFINE(struct sctp_base_info, system_base_info); 111 112 /* 113 * Compute and insert the SCTP checksum in network byte order for a given 114 * mbuf chain m which contains an SCTP packet starting at offset. 115 */ 116 void 117 sctp_delayed_cksum(struct mbuf *m, uint32_t offset) 118 { 119 uint32_t checksum; 120 121 checksum = sctp_calculate_cksum(m, offset); 122 SCTP_STAT_DECR(sctps_sendhwcrc); 123 SCTP_STAT_INCR(sctps_sendswcrc); 124 offset += offsetof(struct sctphdr, checksum); 125 126 if (offset + sizeof(uint32_t) > (uint32_t)(m->m_pkthdr.len)) { 127 #ifdef INVARIANTS 128 panic("sctp_delayed_cksum(): m->m_pkthdr.len: %d, offset: %u.", 129 m->m_pkthdr.len, offset); 130 #else 131 SCTP_PRINTF("sctp_delayed_cksum(): m->m_pkthdr.len: %d, offset: %u.\n", 132 m->m_pkthdr.len, offset); 133 #endif 134 return; 135 } 136 m_copyback(m, (int)offset, (int)sizeof(uint32_t), (caddr_t)&checksum); 137 } 138 #endif 139