1 | /* |
2 | * Copyright (c) 2000-2017 Apple Inc. All rights reserved. |
3 | * |
4 | * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ |
5 | * |
6 | * This file contains Original Code and/or Modifications of Original Code |
7 | * as defined in and that are subject to the Apple Public Source License |
8 | * Version 2.0 (the 'License'). You may not use this file except in |
9 | * compliance with the License. The rights granted to you under the License |
10 | * may not be used to create, or enable the creation or redistribution of, |
11 | * unlawful or unlicensed copies of an Apple operating system, or to |
12 | * circumvent, violate, or enable the circumvention or violation of, any |
13 | * terms of an Apple operating system software license agreement. |
14 | * |
15 | * Please obtain a copy of the License at |
16 | * http://www.opensource.apple.com/apsl/ and read it before using this file. |
17 | * |
18 | * The Original Code and all software distributed under the License are |
19 | * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER |
20 | * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, |
21 | * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, |
22 | * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. |
23 | * Please see the License for the specific language governing rights and |
24 | * limitations under the License. |
25 | * |
26 | * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ |
27 | */ |
28 | /* |
29 | * Copyright (c) 1988, 1992, 1993 |
30 | * The Regents of the University of California. All rights reserved. |
31 | * |
32 | * Redistribution and use in source and binary forms, with or without |
33 | * modification, are permitted provided that the following conditions |
34 | * are met: |
35 | * 1. Redistributions of source code must retain the above copyright |
36 | * notice, this list of conditions and the following disclaimer. |
37 | * 2. Redistributions in binary form must reproduce the above copyright |
38 | * notice, this list of conditions and the following disclaimer in the |
39 | * documentation and/or other materials provided with the distribution. |
40 | * 3. All advertising materials mentioning features or use of this software |
41 | * must display the following acknowledgement: |
42 | * This product includes software developed by the University of |
43 | * California, Berkeley and its contributors. |
44 | * 4. Neither the name of the University nor the names of its contributors |
45 | * may be used to endorse or promote products derived from this software |
46 | * without specific prior written permission. |
47 | * |
48 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
49 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
50 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
51 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
52 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
53 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
54 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
55 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
56 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
57 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
58 | * SUCH DAMAGE. |
59 | * |
60 | * @(#)in_cksum.c 8.1 (Berkeley) 6/10/93 |
61 | */ |
62 | |
63 | #include <sys/param.h> |
64 | #include <machine/endian.h> |
65 | #include <sys/mbuf.h> |
66 | #include <kern/debug.h> |
67 | #include <net/dlil.h> |
68 | #include <netinet/in.h> |
69 | #define _IP_VHL |
70 | #include <netinet/ip.h> |
71 | #include <netinet/ip_var.h> |
72 | |
73 | /* |
74 | * Checksum routine for Internet Protocol family headers (Portable Version). |
75 | * |
76 | * This routine is very heavily used in the network |
77 | * code and should be modified for each CPU to be as fast as possible. |
78 | */ |
79 | #define REDUCE16 { \ |
80 | q_util.q = sum; \ |
81 | l_util.l = q_util.s[0] + q_util.s[1] + q_util.s[2] + q_util.s[3]; \ |
82 | sum = l_util.s[0] + l_util.s[1]; \ |
83 | ADDCARRY(sum); \ |
84 | } |
85 | |
86 | union l_util { |
87 | uint16_t s[2]; |
88 | uint32_t l; |
89 | }; |
90 | |
91 | union q_util { |
92 | uint16_t s[4]; |
93 | uint32_t l[2]; |
94 | uint64_t q; |
95 | }; |
96 | |
97 | extern uint32_t os_cpu_in_cksum(const void *, uint32_t, uint32_t); |
98 | |
99 | /* |
100 | * Perform 16-bit 1's complement sum on a contiguous span. |
101 | */ |
102 | uint16_t |
103 | b_sum16(const void *buf, int len) |
104 | { |
105 | return (os_cpu_in_cksum(buf, len, 0)); |
106 | } |
107 | |
108 | uint16_t inet_cksum_simple(struct mbuf *, int); |
109 | /* |
110 | * For the exported _in_cksum symbol in BSDKernel symbol set. |
111 | */ |
112 | uint16_t |
113 | inet_cksum_simple(struct mbuf *m, int len) |
114 | { |
115 | return (inet_cksum(m, 0, 0, len)); |
116 | } |
117 | |
118 | uint16_t |
119 | in_addword(uint16_t a, uint16_t b) |
120 | { |
121 | uint64_t sum = a + b; |
122 | |
123 | ADDCARRY(sum); |
124 | return (sum); |
125 | } |
126 | |
127 | uint16_t |
128 | in_pseudo(uint32_t a, uint32_t b, uint32_t c) |
129 | { |
130 | uint64_t sum; |
131 | union q_util q_util; |
132 | union l_util l_util; |
133 | |
134 | sum = (uint64_t)a + b + c; |
135 | REDUCE16; |
136 | return (sum); |
137 | } |
138 | |
139 | uint16_t |
140 | in_pseudo64(uint64_t a, uint64_t b, uint64_t c) |
141 | { |
142 | uint64_t sum; |
143 | union q_util q_util; |
144 | union l_util l_util; |
145 | |
146 | sum = a + b + c; |
147 | REDUCE16; |
148 | return (sum); |
149 | } |
150 | |
151 | /* |
152 | * May be used on IP header with options. |
153 | */ |
154 | uint16_t |
155 | in_cksum_hdr_opt(const struct ip *ip) |
156 | { |
157 | return (~b_sum16(ip, (IP_VHL_HL(ip->ip_vhl) << 2)) & 0xffff); |
158 | } |
159 | |
160 | /* |
161 | * A wrapper around the simple in_cksum_hdr() and the more complicated |
162 | * inet_cksum(); the former is chosen if the IP header is simple, |
163 | * contiguous and 32-bit aligned. Also does some stats accounting. |
164 | */ |
165 | uint16_t |
166 | ip_cksum_hdr_dir(struct mbuf *m, uint32_t hlen, int out) |
167 | { |
168 | struct ip *ip = mtod(m, struct ip *); |
169 | |
170 | if (out) { |
171 | ipstat.ips_snd_swcsum++; |
172 | ipstat.ips_snd_swcsum_bytes += hlen; |
173 | } else { |
174 | ipstat.ips_rcv_swcsum++; |
175 | ipstat.ips_rcv_swcsum_bytes += hlen; |
176 | } |
177 | |
178 | if (hlen == sizeof (*ip) && |
179 | m->m_len >= sizeof (*ip) && IP_HDR_ALIGNED_P(ip)) |
180 | return (in_cksum_hdr(ip)); |
181 | |
182 | return (inet_cksum(m, 0, 0, hlen)); |
183 | } |
184 | |
185 | uint16_t |
186 | ip_cksum_hdr_dir_buffer(const void *buffer, uint32_t hlen, uint32_t len, |
187 | int out) |
188 | { |
189 | const struct ip *ip = buffer; |
190 | |
191 | if (out) { |
192 | ipstat.ips_snd_swcsum++; |
193 | ipstat.ips_snd_swcsum_bytes += hlen; |
194 | } else { |
195 | ipstat.ips_rcv_swcsum++; |
196 | ipstat.ips_rcv_swcsum_bytes += hlen; |
197 | } |
198 | |
199 | if (hlen == sizeof (*ip) && |
200 | len >= sizeof (*ip) && IP_HDR_ALIGNED_P(ip)) |
201 | return (in_cksum_hdr(ip)); |
202 | |
203 | return (inet_cksum_buffer(buffer, 0, 0, hlen)); |
204 | } |
205 | |
206 | /* |
207 | * m MUST contain at least an IP header, if nxt is specified; |
208 | * nxt is the upper layer protocol number; |
209 | * off is an offset where TCP/UDP/ICMP header starts; |
210 | * len is a total length of a transport segment (e.g. TCP header + TCP payload) |
211 | */ |
212 | uint16_t |
213 | inet_cksum(struct mbuf *m, uint32_t nxt, uint32_t off, uint32_t len) |
214 | { |
215 | uint32_t sum; |
216 | |
217 | sum = m_sum16(m, off, len); |
218 | |
219 | /* include pseudo header checksum? */ |
220 | if (nxt != 0) { |
221 | struct ip *ip; |
222 | unsigned char buf[sizeof ((*ip))] __attribute__((aligned(8))); |
223 | uint32_t mlen; |
224 | |
225 | /* |
226 | * Sanity check |
227 | * |
228 | * Use m_length2() instead of m_length(), as we cannot rely on |
229 | * the caller setting m_pkthdr.len correctly, if the mbuf is |
230 | * a M_PKTHDR one. |
231 | */ |
232 | if ((mlen = m_length2(m, NULL)) < sizeof (*ip)) { |
233 | panic("%s: mbuf %p too short (%d) for IPv4 header" , |
234 | __func__, m, mlen); |
235 | /* NOTREACHED */ |
236 | } |
237 | |
238 | /* |
239 | * In case the IP header is not contiguous, or not 32-bit |
240 | * aligned, copy it to a local buffer. Note here that we |
241 | * expect the data pointer to point to the IP header. |
242 | */ |
243 | if ((sizeof (*ip) > m->m_len) || |
244 | !IP_HDR_ALIGNED_P(mtod(m, caddr_t))) { |
245 | m_copydata(m, 0, sizeof (*ip), (caddr_t)buf); |
246 | ip = (struct ip *)(void *)buf; |
247 | } else { |
248 | ip = (struct ip *)(void *)(m->m_data); |
249 | } |
250 | |
251 | /* add pseudo header checksum */ |
252 | sum += in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, |
253 | htonl(len + nxt)); |
254 | |
255 | /* fold in carry bits */ |
256 | ADDCARRY(sum); |
257 | } |
258 | |
259 | return (~sum & 0xffff); |
260 | } |
261 | |
262 | /* |
263 | * buffer MUST contain at least an IP header, if nxt is specified; |
264 | * nxt is the upper layer protocol number; |
265 | * off is an offset where TCP/UDP/ICMP header starts; |
266 | * len is a total length of a transport segment (e.g. TCP header + TCP payload) |
267 | */ |
268 | uint16_t |
269 | inet_cksum_buffer(const void *buffer, uint32_t nxt, uint32_t off, |
270 | uint32_t len) |
271 | { |
272 | uint32_t sum; |
273 | |
274 | if (off >= len) |
275 | panic("%s: off (%d) >= len (%d)" , __func__, off, len); |
276 | |
277 | sum = b_sum16(&((const uint8_t *)buffer)[off], len); |
278 | |
279 | /* include pseudo header checksum? */ |
280 | if (nxt != 0) { |
281 | const struct ip *ip; |
282 | unsigned char buf[sizeof ((*ip))] __attribute__((aligned(8))); |
283 | |
284 | /* |
285 | * In case the IP header is not contiguous, or not 32-bit |
286 | * aligned, copy it to a local buffer. Note here that we |
287 | * expect the data pointer to point to the IP header. |
288 | */ |
289 | if (!IP_HDR_ALIGNED_P(buffer)) { |
290 | memcpy(buf, buffer, sizeof (*ip)); |
291 | ip = (const struct ip *)(const void *)buf; |
292 | } else { |
293 | ip = (const struct ip *)buffer; |
294 | } |
295 | |
296 | /* add pseudo header checksum */ |
297 | sum += in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, |
298 | htonl(len + nxt)); |
299 | |
300 | /* fold in carry bits */ |
301 | ADDCARRY(sum); |
302 | } |
303 | |
304 | return (~sum & 0xffff); |
305 | } |
306 | |
307 | #if DEBUG || DEVELOPMENT |
308 | #include <pexpert/pexpert.h> |
309 | |
310 | #define CKSUM_ERR kprintf |
311 | |
312 | /* |
313 | * The following routines implement the portable, reference implementation |
314 | * of os_cpu_in_cksum_mbuf(). This is currently used only for validating |
315 | * the correctness of the platform-specific implementation, at boot time |
316 | * in dlil_verify_sum16(). It returns the 32-bit accumulator without doing |
317 | * a 1's complement on it. |
318 | */ |
319 | #if !defined(__LP64__) |
320 | /* 32-bit version */ |
321 | uint32_t |
322 | in_cksum_mbuf_ref(struct mbuf *m, int len, int off, uint32_t initial_sum) |
323 | { |
324 | int mlen; |
325 | uint32_t sum, partial; |
326 | unsigned int final_acc; |
327 | uint8_t *data; |
328 | boolean_t needs_swap, started_on_odd; |
329 | |
330 | VERIFY(len >= 0); |
331 | VERIFY(off >= 0); |
332 | |
333 | needs_swap = FALSE; |
334 | started_on_odd = FALSE; |
335 | sum = (initial_sum >> 16) + (initial_sum & 0xffff); |
336 | |
337 | for (;;) { |
338 | if (__improbable(m == NULL)) { |
339 | CKSUM_ERR("%s: out of data\n" , __func__); |
340 | return ((uint32_t)-1); |
341 | } |
342 | mlen = m->m_len; |
343 | if (mlen > off) { |
344 | mlen -= off; |
345 | data = mtod(m, uint8_t *) + off; |
346 | goto post_initial_offset; |
347 | } |
348 | off -= mlen; |
349 | if (len == 0) |
350 | break; |
351 | m = m->m_next; |
352 | } |
353 | |
354 | for (; len > 0; m = m->m_next) { |
355 | if (__improbable(m == NULL)) { |
356 | CKSUM_ERR("%s: out of data\n" , __func__); |
357 | return ((uint32_t)-1); |
358 | } |
359 | mlen = m->m_len; |
360 | data = mtod(m, uint8_t *); |
361 | post_initial_offset: |
362 | if (mlen == 0) |
363 | continue; |
364 | if (mlen > len) |
365 | mlen = len; |
366 | len -= mlen; |
367 | |
368 | partial = 0; |
369 | if ((uintptr_t)data & 1) { |
370 | /* Align on word boundary */ |
371 | started_on_odd = !started_on_odd; |
372 | #if BYTE_ORDER == LITTLE_ENDIAN |
373 | partial = *data << 8; |
374 | #else /* BYTE_ORDER != LITTLE_ENDIAN */ |
375 | partial = *data; |
376 | #endif /* BYTE_ORDER != LITTLE_ENDIAN */ |
377 | ++data; |
378 | --mlen; |
379 | } |
380 | needs_swap = started_on_odd; |
381 | while (mlen >= 32) { |
382 | __builtin_prefetch(data + 32); |
383 | partial += *(uint16_t *)(void *)data; |
384 | partial += *(uint16_t *)(void *)(data + 2); |
385 | partial += *(uint16_t *)(void *)(data + 4); |
386 | partial += *(uint16_t *)(void *)(data + 6); |
387 | partial += *(uint16_t *)(void *)(data + 8); |
388 | partial += *(uint16_t *)(void *)(data + 10); |
389 | partial += *(uint16_t *)(void *)(data + 12); |
390 | partial += *(uint16_t *)(void *)(data + 14); |
391 | partial += *(uint16_t *)(void *)(data + 16); |
392 | partial += *(uint16_t *)(void *)(data + 18); |
393 | partial += *(uint16_t *)(void *)(data + 20); |
394 | partial += *(uint16_t *)(void *)(data + 22); |
395 | partial += *(uint16_t *)(void *)(data + 24); |
396 | partial += *(uint16_t *)(void *)(data + 26); |
397 | partial += *(uint16_t *)(void *)(data + 28); |
398 | partial += *(uint16_t *)(void *)(data + 30); |
399 | data += 32; |
400 | mlen -= 32; |
401 | if (__improbable(partial & 0xc0000000)) { |
402 | if (needs_swap) |
403 | partial = (partial << 8) + |
404 | (partial >> 24); |
405 | sum += (partial >> 16); |
406 | sum += (partial & 0xffff); |
407 | partial = 0; |
408 | } |
409 | } |
410 | if (mlen & 16) { |
411 | partial += *(uint16_t *)(void *)data; |
412 | partial += *(uint16_t *)(void *)(data + 2); |
413 | partial += *(uint16_t *)(void *)(data + 4); |
414 | partial += *(uint16_t *)(void *)(data + 6); |
415 | partial += *(uint16_t *)(void *)(data + 8); |
416 | partial += *(uint16_t *)(void *)(data + 10); |
417 | partial += *(uint16_t *)(void *)(data + 12); |
418 | partial += *(uint16_t *)(void *)(data + 14); |
419 | data += 16; |
420 | mlen -= 16; |
421 | } |
422 | /* |
423 | * mlen is not updated below as the remaining tests |
424 | * are using bit masks, which are not affected. |
425 | */ |
426 | if (mlen & 8) { |
427 | partial += *(uint16_t *)(void *)data; |
428 | partial += *(uint16_t *)(void *)(data + 2); |
429 | partial += *(uint16_t *)(void *)(data + 4); |
430 | partial += *(uint16_t *)(void *)(data + 6); |
431 | data += 8; |
432 | } |
433 | if (mlen & 4) { |
434 | partial += *(uint16_t *)(void *)data; |
435 | partial += *(uint16_t *)(void *)(data + 2); |
436 | data += 4; |
437 | } |
438 | if (mlen & 2) { |
439 | partial += *(uint16_t *)(void *)data; |
440 | data += 2; |
441 | } |
442 | if (mlen & 1) { |
443 | #if BYTE_ORDER == LITTLE_ENDIAN |
444 | partial += *data; |
445 | #else /* BYTE_ORDER != LITTLE_ENDIAN */ |
446 | partial += *data << 8; |
447 | #endif /* BYTE_ORDER != LITTLE_ENDIAN */ |
448 | started_on_odd = !started_on_odd; |
449 | } |
450 | |
451 | if (needs_swap) |
452 | partial = (partial << 8) + (partial >> 24); |
453 | sum += (partial >> 16) + (partial & 0xffff); |
454 | /* |
455 | * Reduce sum to allow potential byte swap |
456 | * in the next iteration without carry. |
457 | */ |
458 | sum = (sum >> 16) + (sum & 0xffff); |
459 | } |
460 | final_acc = ((sum >> 16) & 0xffff) + (sum & 0xffff); |
461 | final_acc = (final_acc >> 16) + (final_acc & 0xffff); |
462 | return (final_acc & 0xffff); |
463 | } |
464 | |
465 | #else /* __LP64__ */ |
466 | /* 64-bit version */ |
467 | uint32_t |
468 | in_cksum_mbuf_ref(struct mbuf *m, int len, int off, uint32_t initial_sum) |
469 | { |
470 | int mlen; |
471 | uint64_t sum, partial; |
472 | unsigned int final_acc; |
473 | uint8_t *data; |
474 | boolean_t needs_swap, started_on_odd; |
475 | |
476 | VERIFY(len >= 0); |
477 | VERIFY(off >= 0); |
478 | |
479 | needs_swap = FALSE; |
480 | started_on_odd = FALSE; |
481 | sum = initial_sum; |
482 | |
483 | for (;;) { |
484 | if (__improbable(m == NULL)) { |
485 | CKSUM_ERR("%s: out of data\n" , __func__); |
486 | return ((uint32_t)-1); |
487 | } |
488 | mlen = m->m_len; |
489 | if (mlen > off) { |
490 | mlen -= off; |
491 | data = mtod(m, uint8_t *) + off; |
492 | goto post_initial_offset; |
493 | } |
494 | off -= mlen; |
495 | if (len == 0) |
496 | break; |
497 | m = m->m_next; |
498 | } |
499 | |
500 | for (; len > 0; m = m->m_next) { |
501 | if (__improbable(m == NULL)) { |
502 | CKSUM_ERR("%s: out of data\n" , __func__); |
503 | return ((uint32_t)-1); |
504 | } |
505 | mlen = m->m_len; |
506 | data = mtod(m, uint8_t *); |
507 | post_initial_offset: |
508 | if (mlen == 0) |
509 | continue; |
510 | if (mlen > len) |
511 | mlen = len; |
512 | len -= mlen; |
513 | |
514 | partial = 0; |
515 | if ((uintptr_t)data & 1) { |
516 | /* Align on word boundary */ |
517 | started_on_odd = !started_on_odd; |
518 | #if BYTE_ORDER == LITTLE_ENDIAN |
519 | partial = *data << 8; |
520 | #else /* BYTE_ORDER != LITTLE_ENDIAN */ |
521 | partial = *data; |
522 | #endif /* BYTE_ORDER != LITTLE_ENDIAN */ |
523 | ++data; |
524 | --mlen; |
525 | } |
526 | needs_swap = started_on_odd; |
527 | if ((uintptr_t)data & 2) { |
528 | if (mlen < 2) |
529 | goto trailing_bytes; |
530 | partial += *(uint16_t *)(void *)data; |
531 | data += 2; |
532 | mlen -= 2; |
533 | } |
534 | while (mlen >= 64) { |
535 | __builtin_prefetch(data + 32); |
536 | __builtin_prefetch(data + 64); |
537 | partial += *(uint32_t *)(void *)data; |
538 | partial += *(uint32_t *)(void *)(data + 4); |
539 | partial += *(uint32_t *)(void *)(data + 8); |
540 | partial += *(uint32_t *)(void *)(data + 12); |
541 | partial += *(uint32_t *)(void *)(data + 16); |
542 | partial += *(uint32_t *)(void *)(data + 20); |
543 | partial += *(uint32_t *)(void *)(data + 24); |
544 | partial += *(uint32_t *)(void *)(data + 28); |
545 | partial += *(uint32_t *)(void *)(data + 32); |
546 | partial += *(uint32_t *)(void *)(data + 36); |
547 | partial += *(uint32_t *)(void *)(data + 40); |
548 | partial += *(uint32_t *)(void *)(data + 44); |
549 | partial += *(uint32_t *)(void *)(data + 48); |
550 | partial += *(uint32_t *)(void *)(data + 52); |
551 | partial += *(uint32_t *)(void *)(data + 56); |
552 | partial += *(uint32_t *)(void *)(data + 60); |
553 | data += 64; |
554 | mlen -= 64; |
555 | if (__improbable(partial & (3ULL << 62))) { |
556 | if (needs_swap) |
557 | partial = (partial << 8) + |
558 | (partial >> 56); |
559 | sum += (partial >> 32); |
560 | sum += (partial & 0xffffffff); |
561 | partial = 0; |
562 | } |
563 | } |
564 | /* |
565 | * mlen is not updated below as the remaining tests |
566 | * are using bit masks, which are not affected. |
567 | */ |
568 | if (mlen & 32) { |
569 | partial += *(uint32_t *)(void *)data; |
570 | partial += *(uint32_t *)(void *)(data + 4); |
571 | partial += *(uint32_t *)(void *)(data + 8); |
572 | partial += *(uint32_t *)(void *)(data + 12); |
573 | partial += *(uint32_t *)(void *)(data + 16); |
574 | partial += *(uint32_t *)(void *)(data + 20); |
575 | partial += *(uint32_t *)(void *)(data + 24); |
576 | partial += *(uint32_t *)(void *)(data + 28); |
577 | data += 32; |
578 | } |
579 | if (mlen & 16) { |
580 | partial += *(uint32_t *)(void *)data; |
581 | partial += *(uint32_t *)(void *)(data + 4); |
582 | partial += *(uint32_t *)(void *)(data + 8); |
583 | partial += *(uint32_t *)(void *)(data + 12); |
584 | data += 16; |
585 | } |
586 | if (mlen & 8) { |
587 | partial += *(uint32_t *)(void *)data; |
588 | partial += *(uint32_t *)(void *)(data + 4); |
589 | data += 8; |
590 | } |
591 | if (mlen & 4) { |
592 | partial += *(uint32_t *)(void *)data; |
593 | data += 4; |
594 | } |
595 | if (mlen & 2) { |
596 | partial += *(uint16_t *)(void *)data; |
597 | data += 2; |
598 | } |
599 | trailing_bytes: |
600 | if (mlen & 1) { |
601 | #if BYTE_ORDER == LITTLE_ENDIAN |
602 | partial += *data; |
603 | #else /* BYTE_ORDER != LITTLE_ENDIAN */ |
604 | partial += *data << 8; |
605 | #endif /* BYTE_ORDER != LITTLE_ENDIAN */ |
606 | started_on_odd = !started_on_odd; |
607 | } |
608 | |
609 | if (needs_swap) |
610 | partial = (partial << 8) + (partial >> 56); |
611 | sum += (partial >> 32) + (partial & 0xffffffff); |
612 | /* |
613 | * Reduce sum to allow potential byte swap |
614 | * in the next iteration without carry. |
615 | */ |
616 | sum = (sum >> 32) + (sum & 0xffffffff); |
617 | } |
618 | final_acc = (sum >> 48) + ((sum >> 32) & 0xffff) + |
619 | ((sum >> 16) & 0xffff) + (sum & 0xffff); |
620 | final_acc = (final_acc >> 16) + (final_acc & 0xffff); |
621 | final_acc = (final_acc >> 16) + (final_acc & 0xffff); |
622 | return (final_acc & 0xffff); |
623 | } |
624 | #endif /* __LP64 */ |
625 | #endif /* DEBUG || DEVELOPMENT */ |
626 | |