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 #include "opt_sctp.h" 37 38 #include <sys/param.h> 39 #include <sys/systm.h> 40 #include <sys/gsb_crc32.h> 41 #include <sys/mbuf.h> 42 43 #include <netinet/sctp.h> 44 #include <netinet/sctp_crc32.h> 45 #if defined(SCTP) || defined(SCTP_SUPPORT) 46 #include <netinet/sctp_os.h> 47 #include <netinet/sctp_pcb.h> 48 #endif 49 50 static uint32_t 51 sctp_finalize_crc32c(uint32_t crc32c) 52 { 53 #if BYTE_ORDER == BIG_ENDIAN 54 uint32_t byte0, byte1, byte2, byte3; 55 #endif 56 57 #if BYTE_ORDER == BIG_ENDIAN 58 /* 59 * For BIG-ENDIAN platforms, the result is in LITTLE-ENDIAN byte 60 * order. For LITTLE-ENDIAN platforms, the result is in in 61 * BIG-ENDIAN byte order. So for BIG-ENDIAN platforms the bytes must 62 * be swapped to return the result always in network byte order (aka 63 * BIG-ENDIAN). 64 */ 65 byte0 = crc32c & 0x000000ff; 66 byte1 = (crc32c >> 8) & 0x000000ff; 67 byte2 = (crc32c >> 16) & 0x000000ff; 68 byte3 = (crc32c >> 24) & 0x000000ff; 69 crc32c = ((byte0 << 24) | (byte1 << 16) | (byte2 << 8) | byte3); 70 #endif 71 return (~crc32c); 72 } 73 74 static int 75 sctp_calculate_cksum_cb(void *arg, void *data, u_int len) 76 { 77 uint32_t *basep; 78 79 basep = arg; 80 *basep = calculate_crc32c(*basep, data, len); 81 return (0); 82 } 83 84 /* 85 * Compute the SCTP checksum in network byte order for a given mbuf chain m 86 * which contains an SCTP packet starting at offset. 87 * Since this function is also called by ipfw, don't assume that 88 * it is compiled on a kernel with SCTP support. 89 */ 90 uint32_t 91 sctp_calculate_cksum(struct mbuf *m, int32_t offset) 92 { 93 uint32_t base; 94 int len; 95 96 M_ASSERTPKTHDR(m); 97 KASSERT(offset < m->m_pkthdr.len, 98 ("%s: invalid offset %u into mbuf %p", __func__, offset, m)); 99 100 base = 0xffffffff; 101 len = m->m_pkthdr.len - offset; 102 (void)m_apply(m, offset, len, sctp_calculate_cksum_cb, &base); 103 return (sctp_finalize_crc32c(base)); 104 } 105 106 #if defined(SCTP) || defined(SCTP_SUPPORT) 107 108 VNET_DEFINE(struct sctp_base_info, system_base_info); 109 110 /* 111 * Compute and insert the SCTP checksum in network byte order for a given 112 * mbuf chain m which contains an SCTP packet starting at offset. 113 */ 114 void 115 sctp_delayed_cksum(struct mbuf *m, uint32_t offset) 116 { 117 uint32_t checksum; 118 119 checksum = sctp_calculate_cksum(m, offset); 120 SCTP_STAT_DECR(sctps_sendhwcrc); 121 SCTP_STAT_INCR(sctps_sendswcrc); 122 offset += offsetof(struct sctphdr, checksum); 123 124 if (offset + sizeof(uint32_t) > (uint32_t)(m->m_pkthdr.len)) { 125 #ifdef INVARIANTS 126 panic("sctp_delayed_cksum(): m->m_pkthdr.len: %d, offset: %u.", 127 m->m_pkthdr.len, offset); 128 #else 129 SCTP_PRINTF("sctp_delayed_cksum(): m->m_pkthdr.len: %d, offset: %u.\n", 130 m->m_pkthdr.len, offset); 131 #endif 132 return; 133 } 134 m_copyback(m, (int)offset, (int)sizeof(uint32_t), (caddr_t)&checksum); 135 } 136 #endif 137