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 uint32_t result; 56 #if BYTE_ORDER == BIG_ENDIAN 57 uint8_t byte0, byte1, byte2, byte3; 58 #endif 59 60 /* Complement the result */ 61 result = ~crc32c; 62 #if BYTE_ORDER == BIG_ENDIAN 63 /* 64 * For BIG-ENDIAN platforms the result is in little-endian form. So 65 * we must swap the bytes to return the result in network byte 66 * order. 67 */ 68 byte0 = result & 0x000000ff; 69 byte1 = (result >> 8) & 0x000000ff; 70 byte2 = (result >> 16) & 0x000000ff; 71 byte3 = (result >> 24) & 0x000000ff; 72 crc32c = ((byte0 << 24) | (byte1 << 16) | (byte2 << 8) | byte3); 73 #else 74 /* 75 * For LITTLE ENDIAN platforms the result is in already in network 76 * byte order. 77 */ 78 crc32c = result; 79 #endif 80 return (crc32c); 81 } 82 83 /* 84 * Compute the SCTP checksum in network byte order for a given mbuf chain m 85 * which contains an SCTP packet starting at offset. 86 * Since this function is also called by ipfw, don't assume that 87 * it is compiled on a kernel with SCTP support. 88 */ 89 uint32_t 90 sctp_calculate_cksum(struct mbuf *m, uint32_t offset) 91 { 92 uint32_t base = 0xffffffff; 93 94 while (offset > 0) { 95 KASSERT(m != NULL, ("sctp_calculate_cksum, offset > length of mbuf chain")); 96 if (offset < (uint32_t)m->m_len) { 97 break; 98 } 99 offset -= m->m_len; 100 m = m->m_next; 101 } 102 if (offset > 0) { 103 base = calculate_crc32c(base, 104 (unsigned char *)(m->m_data + offset), 105 (unsigned int)(m->m_len - offset)); 106 m = m->m_next; 107 } 108 while (m != NULL) { 109 base = calculate_crc32c(base, 110 (unsigned char *)m->m_data, 111 (unsigned int)m->m_len); 112 m = m->m_next; 113 } 114 base = sctp_finalize_crc32c(base); 115 return (base); 116 } 117 118 #if defined(SCTP) || defined(SCTP_SUPPORT) 119 120 VNET_DEFINE(struct sctp_base_info, system_base_info); 121 122 /* 123 * Compute and insert the SCTP checksum in network byte order for a given 124 * mbuf chain m which contains an SCTP packet starting at offset. 125 */ 126 void 127 sctp_delayed_cksum(struct mbuf *m, uint32_t offset) 128 { 129 uint32_t checksum; 130 131 checksum = sctp_calculate_cksum(m, offset); 132 SCTP_STAT_DECR(sctps_sendhwcrc); 133 SCTP_STAT_INCR(sctps_sendswcrc); 134 offset += offsetof(struct sctphdr, checksum); 135 136 if (offset + sizeof(uint32_t) > (uint32_t)(m->m_pkthdr.len)) { 137 #ifdef INVARIANTS 138 panic("sctp_delayed_cksum(): m->m_pkthdr.len: %d, offset: %u.", 139 m->m_pkthdr.len, offset); 140 #else 141 SCTP_PRINTF("sctp_delayed_cksum(): m->m_pkthdr.len: %d, offset: %u.\n", 142 m->m_pkthdr.len, offset); 143 #endif 144 return; 145 } 146 m_copyback(m, (int)offset, (int)sizeof(uint32_t), (caddr_t)&checksum); 147 } 148 #endif 149