1/* $FreeBSD: head/sys/netinet6/in6_cksum.c 62587 2000-07-04 16:35:15Z itojun $ */
2/* $KAME: in6_cksum.c,v 1.6 2000/03/25 07:23:43 sumikawa Exp $ */
3 |
4/*
5 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
6 * 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
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the project nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
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28 *
29 * $FreeBSD: head/sys/netinet6/in6_cksum.c 53541 1999-11-22 02:45:11Z shin $
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31 */
32
33/*
34 * Copyright (c) 1988, 1992, 1993
35 * The Regents of the University of California. All rights reserved.
36 *
37 * Redistribution and use in source and binary forms, with or without
38 * modification, are permitted provided that the following conditions
39 * are met:
40 * 1. Redistributions of source code must retain the above copyright
41 * notice, this list of conditions and the following disclaimer.
42 * 2. Redistributions in binary form must reproduce the above copyright
43 * notice, this list of conditions and the following disclaimer in the
44 * documentation and/or other materials provided with the distribution.
45 * 3. All advertising materials mentioning features or use of this software
46 * must display the following acknowledgement:
47 * This product includes software developed by the University of
48 * California, Berkeley and its contributors.
49 * 4. Neither the name of the University nor the names of its contributors
50 * may be used to endorse or promote products derived from this software
51 * without specific prior written permission.
52 *
53 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
54 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
55 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
56 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
57 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
58 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
59 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
60 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
61 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
62 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
63 * SUCH DAMAGE.
64 *
65 * @(#)in_cksum.c 8.1 (Berkeley) 6/10/93
66 */
67
68#include <sys/param.h>
69#include <sys/mbuf.h>
70#include <sys/systm.h>
71#include <netinet/in.h>
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71#include <netinet6/ip6.h>
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| 72#include |
73
74#include <net/net_osdep.h>
75
76/*
77 * Checksum routine for Internet Protocol family headers (Portable Version).
78 *
79 * This routine is very heavily used in the network
80 * code and should be modified for each CPU to be as fast as possible.
81 */
82
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82#define ADDCARRY(x) (x > 65535 ? x -= 65535 : x)
83#define REDUCE {l_util.l = sum; sum = l_util.s[0] + l_util.s[1]; ADDCARRY(sum);}
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83#define ADDCARRY(x) (x > 65535 ? x -= 65535 : x)
84#define REDUCE {l_util.l = sum; sum = l_util.s[0] + l_util.s[1]; ADDCARRY(sum);} |
85
86static union {
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86 u_int16_t phs[4];
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| 87 u_int16_t phs[4]; |
88 struct {
89 u_int32_t ph_len;
90 u_int8_t ph_zero[3];
91 u_int8_t ph_nxt;
92 } ph;
93} uph;
94
95/*
96 * m MUST contain a continuous IP6 header.
97 * off is a offset where TCP/UDP/ICMP6 header starts.
98 * len is a total length of a transport segment.
99 * (e.g. TCP header + TCP payload)
100 */
101
102int
103in6_cksum(m, nxt, off, len)
104 register struct mbuf *m;
105 u_int8_t nxt;
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105 register int off, len;
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| 106 u_int32_t off, len; |
107{
108 register u_int16_t *w;
109 register int sum = 0;
110 register int mlen = 0;
111 int byte_swapped = 0;
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112#if 0
113 int srcifid = 0, dstifid = 0;
114#endif |
115 struct ip6_hdr *ip6;
116
117 union {
118 u_int8_t c[2];
119 u_int16_t s;
120 } s_util;
121 union {
122 u_int16_t s[2];
123 u_int32_t l;
124 } l_util;
125
126 /* sanity check */
127 if (m->m_pkthdr.len < off + len) {
128 panic("in6_cksum: mbuf len (%d) < off+len (%d+%d)\n",
129 m->m_pkthdr.len, off, len);
130 }
131
132 /*
133 * First create IP6 pseudo header and calculate a summary.
134 */
135 ip6 = mtod(m, struct ip6_hdr *);
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136#if 0
137 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) {
138 srcifid = ip6->ip6_src.s6_addr16[1];
139 ip6->ip6_src.s6_addr16[1] = 0;
140 }
141 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) {
142 dstifid = ip6->ip6_dst.s6_addr16[1];
143 ip6->ip6_dst.s6_addr16[1] = 0;
144 }
145#endif |
146 w = (u_int16_t *)&ip6->ip6_src;
147 uph.ph.ph_len = htonl(len);
148 uph.ph.ph_nxt = nxt;
149
150 /* IPv6 source address */
151 sum += w[0];
152 if (!IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src))
153 sum += w[1];
154 sum += w[2]; sum += w[3]; sum += w[4]; sum += w[5];
155 sum += w[6]; sum += w[7];
156 /* IPv6 destination address */
157 sum += w[8];
158 if (!IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst))
159 sum += w[9];
160 sum += w[10]; sum += w[11]; sum += w[12]; sum += w[13];
161 sum += w[14]; sum += w[15];
162 /* Payload length and upper layer identifier */
163 sum += uph.phs[0]; sum += uph.phs[1];
164 sum += uph.phs[2]; sum += uph.phs[3];
165
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166#if 0
167 if (srcifid)
168 ip6->ip6_src.s6_addr16[1] = srcifid;
169 if (dstifid)
170 ip6->ip6_dst.s6_addr16[1] = dstifid;
171#endif |
172 /*
173 * Secondly calculate a summary of the first mbuf excluding offset.
174 */
175 while (m != NULL && off > 0) {
176 if (m->m_len <= off)
177 off -= m->m_len;
178 else
179 break;
180 m = m->m_next;
181 }
182 w = (u_int16_t *)(mtod(m, u_char *) + off);
183 mlen = m->m_len - off;
184 if (len < mlen)
185 mlen = len;
186 len -= mlen;
187 /*
188 * Force to even boundary.
189 */
190 if ((1 & (long) w) && (mlen > 0)) {
191 REDUCE;
192 sum <<= 8;
193 s_util.c[0] = *(u_char *)w;
194 w = (u_int16_t *)((char *)w + 1);
195 mlen--;
196 byte_swapped = 1;
197 }
198 /*
199 * Unroll the loop to make overhead from
200 * branches &c small.
201 */
202 while ((mlen -= 32) >= 0) {
203 sum += w[0]; sum += w[1]; sum += w[2]; sum += w[3];
204 sum += w[4]; sum += w[5]; sum += w[6]; sum += w[7];
205 sum += w[8]; sum += w[9]; sum += w[10]; sum += w[11];
206 sum += w[12]; sum += w[13]; sum += w[14]; sum += w[15];
207 w += 16;
208 }
209 mlen += 32;
210 while ((mlen -= 8) >= 0) {
211 sum += w[0]; sum += w[1]; sum += w[2]; sum += w[3];
212 w += 4;
213 }
214 mlen += 8;
215 if (mlen == 0 && byte_swapped == 0)
216 goto next;
217 REDUCE;
218 while ((mlen -= 2) >= 0) {
219 sum += *w++;
220 }
221 if (byte_swapped) {
222 REDUCE;
223 sum <<= 8;
224 byte_swapped = 0;
225 if (mlen == -1) {
226 s_util.c[1] = *(char *)w;
227 sum += s_util.s;
228 mlen = 0;
229 } else
230 mlen = -1;
231 } else if (mlen == -1)
232 s_util.c[0] = *(char *)w;
233 next:
234 m = m->m_next;
235
236 /*
237 * Lastly calculate a summary of the rest of mbufs.
238 */
239
240 for (;m && len; m = m->m_next) {
241 if (m->m_len == 0)
242 continue;
243 w = mtod(m, u_int16_t *);
244 if (mlen == -1) {
245 /*
246 * The first byte of this mbuf is the continuation
247 * of a word spanning between this mbuf and the
248 * last mbuf.
249 *
250 * s_util.c[0] is already saved when scanning previous
251 * mbuf.
252 */
253 s_util.c[1] = *(char *)w;
254 sum += s_util.s;
255 w = (u_int16_t *)((char *)w + 1);
256 mlen = m->m_len - 1;
257 len--;
258 } else
259 mlen = m->m_len;
260 if (len < mlen)
261 mlen = len;
262 len -= mlen;
263 /*
264 * Force to even boundary.
265 */
266 if ((1 & (long) w) && (mlen > 0)) {
267 REDUCE;
268 sum <<= 8;
269 s_util.c[0] = *(u_char *)w;
270 w = (u_int16_t *)((char *)w + 1);
271 mlen--;
272 byte_swapped = 1;
273 }
274 /*
275 * Unroll the loop to make overhead from
276 * branches &c small.
277 */
278 while ((mlen -= 32) >= 0) {
279 sum += w[0]; sum += w[1]; sum += w[2]; sum += w[3];
280 sum += w[4]; sum += w[5]; sum += w[6]; sum += w[7];
281 sum += w[8]; sum += w[9]; sum += w[10]; sum += w[11];
282 sum += w[12]; sum += w[13]; sum += w[14]; sum += w[15];
283 w += 16;
284 }
285 mlen += 32;
286 while ((mlen -= 8) >= 0) {
287 sum += w[0]; sum += w[1]; sum += w[2]; sum += w[3];
288 w += 4;
289 }
290 mlen += 8;
291 if (mlen == 0 && byte_swapped == 0)
292 continue;
293 REDUCE;
294 while ((mlen -= 2) >= 0) {
295 sum += *w++;
296 }
297 if (byte_swapped) {
298 REDUCE;
299 sum <<= 8;
300 byte_swapped = 0;
301 if (mlen == -1) {
302 s_util.c[1] = *(char *)w;
303 sum += s_util.s;
304 mlen = 0;
305 } else
306 mlen = -1;
307 } else if (mlen == -1)
308 s_util.c[0] = *(char *)w;
309 }
310 if (len)
311 panic("in6_cksum: out of data\n");
312 if (mlen == -1) {
313 /* The last mbuf has odd # of bytes. Follow the
314 standard (the odd byte may be shifted left by 8 bits
315 or not as determined by endian-ness of the machine) */
316 s_util.c[1] = 0;
317 sum += s_util.s;
318 }
319 REDUCE;
320 return (~sum & 0xffff);
321}
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