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/mbuf.h>
43 #include <sys/gsb_crc32.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_len)) {
137 #ifdef INVARIANTS
138 panic("sctp_delayed_cksum(): m->m_len: %d, offset: %u.",
139 m->m_len, offset);
140 #else
141 SCTP_PRINTF("sctp_delayed_cksum(): m->m_len: %d, offset: %u.\n",
142 m->m_len, offset);
143 #endif
144 return;
145 }
146 *(uint32_t *)(m->m_data + offset) = checksum;
147 }
148 #endif
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