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/gsb_crc32.h> 41 #ifdef SCTP 42 #include <netinet/sctp_os.h> 43 #include <netinet/sctp.h> 44 #include <netinet/sctp_crc32.h> 45 #include <netinet/sctp_pcb.h> 46 #else 47 #include <sys/param.h> 48 #include <sys/systm.h> 49 #include <sys/mbuf.h> 50 51 #include <netinet/sctp_crc32.h> 52 #endif 53 54 static uint32_t 55 sctp_finalize_crc32c(uint32_t crc32c) 56 { 57 uint32_t result; 58 #if BYTE_ORDER == BIG_ENDIAN 59 uint8_t byte0, byte1, byte2, byte3; 60 #endif 61 62 /* Complement the result */ 63 result = ~crc32c; 64 #if BYTE_ORDER == BIG_ENDIAN 65 /* 66 * For BIG-ENDIAN platforms the result is in little-endian form. So 67 * we must swap the bytes to return the result in network byte 68 * order. 69 */ 70 byte0 = result & 0x000000ff; 71 byte1 = (result >> 8) & 0x000000ff; 72 byte2 = (result >> 16) & 0x000000ff; 73 byte3 = (result >> 24) & 0x000000ff; 74 crc32c = ((byte0 << 24) | (byte1 << 16) | (byte2 << 8) | byte3); 75 #else 76 /* 77 * For LITTLE ENDIAN platforms the result is in already in network 78 * byte order. 79 */ 80 crc32c = result; 81 #endif 82 return (crc32c); 83 } 84 85 /* 86 * Compute the SCTP checksum in network byte order for a given mbuf chain m 87 * which contains an SCTP packet starting at offset. 88 * Since this function is also called by ipfw, don't assume that 89 * it is compiled on a kernel with SCTP support. 90 */ 91 uint32_t 92 sctp_calculate_cksum(struct mbuf *m, uint32_t offset) 93 { 94 uint32_t base = 0xffffffff; 95 96 while (offset > 0) { 97 KASSERT(m != NULL, ("sctp_calculate_cksum, offset > length of mbuf chain")); 98 if (offset < (uint32_t)m->m_len) { 99 break; 100 } 101 offset -= m->m_len; 102 m = m->m_next; 103 } 104 if (offset > 0) { 105 base = calculate_crc32c(base, 106 (unsigned char *)(m->m_data + offset), 107 (unsigned int)(m->m_len - offset)); 108 m = m->m_next; 109 } 110 while (m != NULL) { 111 base = calculate_crc32c(base, 112 (unsigned char *)m->m_data, 113 (unsigned int)m->m_len); 114 m = m->m_next; 115 } 116 base = sctp_finalize_crc32c(base); 117 return (base); 118 } 119 120 #ifdef SCTP 121 /* 122 * Compute and insert the SCTP checksum in network byte order for a given 123 * mbuf chain m which contains an SCTP packet starting at offset. 124 */ 125 void 126 sctp_delayed_cksum(struct mbuf *m, uint32_t offset) 127 { 128 uint32_t checksum; 129 130 checksum = sctp_calculate_cksum(m, offset); 131 SCTP_STAT_DECR(sctps_sendhwcrc); 132 SCTP_STAT_INCR(sctps_sendswcrc); 133 offset += offsetof(struct sctphdr, checksum); 134 135 if (offset + sizeof(uint32_t) > (uint32_t)(m->m_pkthdr.len)) { 136 #ifdef INVARIANTS 137 panic("sctp_delayed_cksum(): m->m_pkthdr.len: %d, offset: %u.", 138 m->m_pkthdr.len, offset); 139 #else 140 SCTP_PRINTF("sctp_delayed_cksum(): m->m_pkthdr.len: %d, offset: %u.\n", 141 m->m_pkthdr.len, offset); 142 #endif 143 return; 144 } 145 m_copyback(m, (int)offset, (int)sizeof(uint32_t), (caddr_t)&checksum); 146 } 147 #endif 148