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 (uint16_t)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 (uint16_t)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 (uint16_t)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 (uint16_t)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(buf: ip, len: (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 | |
183 | return inet_cksum(m, 0, 0, hlen); |
184 | } |
185 | |
186 | uint16_t |
187 | ip_cksum_hdr_dir_buffer(const void *buffer, uint32_t hlen, uint32_t len, |
188 | int out) |
189 | { |
190 | const struct ip *ip = buffer; |
191 | |
192 | if (out) { |
193 | ipstat.ips_snd_swcsum++; |
194 | ipstat.ips_snd_swcsum_bytes += hlen; |
195 | } else { |
196 | ipstat.ips_rcv_swcsum++; |
197 | ipstat.ips_rcv_swcsum_bytes += hlen; |
198 | } |
199 | |
200 | if (hlen == sizeof(*ip) && |
201 | len >= sizeof(*ip) && IP_HDR_ALIGNED_P(ip)) { |
202 | return in_cksum_hdr(ip); |
203 | } |
204 | |
205 | return inet_cksum_buffer(buffer, 0, 0, len: hlen); |
206 | } |
207 | |
208 | /* |
209 | * m MUST contain at least an IP header, if nxt is specified; |
210 | * nxt is the upper layer protocol number; |
211 | * off is an offset where TCP/UDP/ICMP header starts; |
212 | * len is a total length of a transport segment (e.g. TCP header + TCP payload) |
213 | */ |
214 | uint16_t |
215 | inet_cksum(struct mbuf *m, uint32_t nxt, uint32_t off, uint32_t len) |
216 | { |
217 | uint32_t sum; |
218 | |
219 | sum = m_sum16(m, off, len); |
220 | |
221 | /* include pseudo header checksum? */ |
222 | if (nxt != 0) { |
223 | struct ip *ip; |
224 | unsigned char buf[sizeof((*ip))] __attribute__((aligned(8))); |
225 | uint32_t mlen; |
226 | |
227 | /* |
228 | * Sanity check |
229 | * |
230 | * Use m_length2() instead of m_length(), as we cannot rely on |
231 | * the caller setting m_pkthdr.len correctly, if the mbuf is |
232 | * a M_PKTHDR one. |
233 | */ |
234 | if ((mlen = m_length2(m, NULL)) < sizeof(*ip)) { |
235 | panic("%s: mbuf %p too short (%d) for IPv4 header" , |
236 | __func__, m, mlen); |
237 | /* NOTREACHED */ |
238 | } |
239 | |
240 | /* |
241 | * In case the IP header is not contiguous, or not 32-bit |
242 | * aligned, copy it to a local buffer. Note here that we |
243 | * expect the data pointer to point to the IP header. |
244 | */ |
245 | if ((sizeof(*ip) > m->m_len) || |
246 | !IP_HDR_ALIGNED_P(mtod(m, caddr_t))) { |
247 | m_copydata(m, 0, sizeof(*ip), (caddr_t)buf); |
248 | ip = (struct ip *)(void *)buf; |
249 | } else { |
250 | ip = (struct ip *)(void *)(m->m_data); |
251 | } |
252 | |
253 | /* add pseudo header checksum */ |
254 | sum += in_pseudo(a: ip->ip_src.s_addr, b: ip->ip_dst.s_addr, |
255 | htonl(len + nxt)); |
256 | |
257 | /* fold in carry bits */ |
258 | ADDCARRY(sum); |
259 | } |
260 | |
261 | return ~sum & 0xffff; |
262 | } |
263 | |
264 | /* |
265 | * buffer MUST contain at least an IP header, if nxt is specified; |
266 | * nxt is the upper layer protocol number; |
267 | * off is an offset where TCP/UDP/ICMP header starts; |
268 | * len is a total length of a transport segment (e.g. TCP header + TCP payload) |
269 | */ |
270 | uint16_t |
271 | inet_cksum_buffer(const void *buffer, uint32_t nxt, uint32_t off, |
272 | uint32_t len) |
273 | { |
274 | uint32_t sum; |
275 | |
276 | if (off >= len) { |
277 | panic("%s: off (%d) >= len (%d)" , __func__, off, len); |
278 | } |
279 | |
280 | sum = b_sum16(buf: &((const uint8_t *)buffer)[off], len); |
281 | |
282 | /* include pseudo header checksum? */ |
283 | if (nxt != 0) { |
284 | const struct ip *ip; |
285 | unsigned char buf[sizeof((*ip))] __attribute__((aligned(8))); |
286 | |
287 | /* |
288 | * In case the IP header is not contiguous, or not 32-bit |
289 | * aligned, copy it to a local buffer. Note here that we |
290 | * expect the data pointer to point to the IP header. |
291 | */ |
292 | if (!IP_HDR_ALIGNED_P(buffer)) { |
293 | memcpy(dst: buf, src: buffer, n: sizeof(*ip)); |
294 | ip = (const struct ip *)(const void *)buf; |
295 | } else { |
296 | ip = (const struct ip *)buffer; |
297 | } |
298 | |
299 | /* add pseudo header checksum */ |
300 | sum += in_pseudo(a: ip->ip_src.s_addr, b: ip->ip_dst.s_addr, |
301 | htonl(len + nxt)); |
302 | |
303 | /* fold in carry bits */ |
304 | ADDCARRY(sum); |
305 | } |
306 | |
307 | return ~sum & 0xffff; |
308 | } |
309 | |
310 | #if DEBUG || DEVELOPMENT |
311 | #include <pexpert/pexpert.h> |
312 | |
313 | #define CKSUM_ERR kprintf |
314 | |
315 | /* |
316 | * The following routines implement the portable, reference implementation |
317 | * of os_cpu_in_cksum_mbuf(). This is currently used only for validating |
318 | * the correctness of the platform-specific implementation, at boot time |
319 | * in dlil_verify_sum16(). It returns the 32-bit accumulator without doing |
320 | * a 1's complement on it. |
321 | */ |
322 | #if !defined(__LP64__) |
323 | /* 32-bit version */ |
324 | uint32_t |
325 | in_cksum_mbuf_ref(struct mbuf *m, int len, int off, uint32_t initial_sum) |
326 | { |
327 | int mlen; |
328 | uint32_t sum, partial; |
329 | unsigned int final_acc; |
330 | uint8_t *data; |
331 | boolean_t needs_swap, started_on_odd; |
332 | |
333 | VERIFY(len >= 0); |
334 | VERIFY(off >= 0); |
335 | |
336 | needs_swap = FALSE; |
337 | started_on_odd = FALSE; |
338 | sum = (initial_sum >> 16) + (initial_sum & 0xffff); |
339 | |
340 | for (;;) { |
341 | if (__improbable(m == NULL)) { |
342 | CKSUM_ERR("%s: out of data\n" , __func__); |
343 | return (uint32_t)-1; |
344 | } |
345 | mlen = m->m_len; |
346 | if (mlen > off) { |
347 | mlen -= off; |
348 | data = mtod(m, uint8_t *) + off; |
349 | goto post_initial_offset; |
350 | } |
351 | off -= mlen; |
352 | if (len == 0) { |
353 | break; |
354 | } |
355 | m = m->m_next; |
356 | } |
357 | |
358 | for (; len > 0; m = m->m_next) { |
359 | if (__improbable(m == NULL)) { |
360 | CKSUM_ERR("%s: out of data\n" , __func__); |
361 | return (uint32_t)-1; |
362 | } |
363 | mlen = m->m_len; |
364 | data = mtod(m, uint8_t *); |
365 | post_initial_offset: |
366 | if (mlen == 0) { |
367 | continue; |
368 | } |
369 | if (mlen > len) { |
370 | mlen = len; |
371 | } |
372 | len -= mlen; |
373 | |
374 | partial = 0; |
375 | if ((uintptr_t)data & 1) { |
376 | /* Align on word boundary */ |
377 | started_on_odd = !started_on_odd; |
378 | #if BYTE_ORDER == LITTLE_ENDIAN |
379 | partial = *data << 8; |
380 | #else /* BYTE_ORDER != LITTLE_ENDIAN */ |
381 | partial = *data; |
382 | #endif /* BYTE_ORDER != LITTLE_ENDIAN */ |
383 | ++data; |
384 | --mlen; |
385 | } |
386 | needs_swap = started_on_odd; |
387 | while (mlen >= 32) { |
388 | __builtin_prefetch(data + 32); |
389 | partial += *(uint16_t *)(void *)data; |
390 | partial += *(uint16_t *)(void *)(data + 2); |
391 | partial += *(uint16_t *)(void *)(data + 4); |
392 | partial += *(uint16_t *)(void *)(data + 6); |
393 | partial += *(uint16_t *)(void *)(data + 8); |
394 | partial += *(uint16_t *)(void *)(data + 10); |
395 | partial += *(uint16_t *)(void *)(data + 12); |
396 | partial += *(uint16_t *)(void *)(data + 14); |
397 | partial += *(uint16_t *)(void *)(data + 16); |
398 | partial += *(uint16_t *)(void *)(data + 18); |
399 | partial += *(uint16_t *)(void *)(data + 20); |
400 | partial += *(uint16_t *)(void *)(data + 22); |
401 | partial += *(uint16_t *)(void *)(data + 24); |
402 | partial += *(uint16_t *)(void *)(data + 26); |
403 | partial += *(uint16_t *)(void *)(data + 28); |
404 | partial += *(uint16_t *)(void *)(data + 30); |
405 | data += 32; |
406 | mlen -= 32; |
407 | if (__improbable(partial & 0xc0000000)) { |
408 | if (needs_swap) { |
409 | partial = (partial << 8) + |
410 | (partial >> 24); |
411 | } |
412 | sum += (partial >> 16); |
413 | sum += (partial & 0xffff); |
414 | partial = 0; |
415 | } |
416 | } |
417 | if (mlen & 16) { |
418 | partial += *(uint16_t *)(void *)data; |
419 | partial += *(uint16_t *)(void *)(data + 2); |
420 | partial += *(uint16_t *)(void *)(data + 4); |
421 | partial += *(uint16_t *)(void *)(data + 6); |
422 | partial += *(uint16_t *)(void *)(data + 8); |
423 | partial += *(uint16_t *)(void *)(data + 10); |
424 | partial += *(uint16_t *)(void *)(data + 12); |
425 | partial += *(uint16_t *)(void *)(data + 14); |
426 | data += 16; |
427 | mlen -= 16; |
428 | } |
429 | /* |
430 | * mlen is not updated below as the remaining tests |
431 | * are using bit masks, which are not affected. |
432 | */ |
433 | if (mlen & 8) { |
434 | partial += *(uint16_t *)(void *)data; |
435 | partial += *(uint16_t *)(void *)(data + 2); |
436 | partial += *(uint16_t *)(void *)(data + 4); |
437 | partial += *(uint16_t *)(void *)(data + 6); |
438 | data += 8; |
439 | } |
440 | if (mlen & 4) { |
441 | partial += *(uint16_t *)(void *)data; |
442 | partial += *(uint16_t *)(void *)(data + 2); |
443 | data += 4; |
444 | } |
445 | if (mlen & 2) { |
446 | partial += *(uint16_t *)(void *)data; |
447 | data += 2; |
448 | } |
449 | if (mlen & 1) { |
450 | #if BYTE_ORDER == LITTLE_ENDIAN |
451 | partial += *data; |
452 | #else /* BYTE_ORDER != LITTLE_ENDIAN */ |
453 | partial += *data << 8; |
454 | #endif /* BYTE_ORDER != LITTLE_ENDIAN */ |
455 | started_on_odd = !started_on_odd; |
456 | } |
457 | |
458 | if (needs_swap) { |
459 | partial = (partial << 8) + (partial >> 24); |
460 | } |
461 | sum += (partial >> 16) + (partial & 0xffff); |
462 | /* |
463 | * Reduce sum to allow potential byte swap |
464 | * in the next iteration without carry. |
465 | */ |
466 | sum = (sum >> 16) + (sum & 0xffff); |
467 | } |
468 | final_acc = ((sum >> 16) & 0xffff) + (sum & 0xffff); |
469 | final_acc = (final_acc >> 16) + (final_acc & 0xffff); |
470 | return final_acc & 0xffff; |
471 | } |
472 | |
473 | #else /* __LP64__ */ |
474 | /* 64-bit version */ |
475 | uint32_t |
476 | in_cksum_mbuf_ref(struct mbuf *m, int len, int off, uint32_t initial_sum) |
477 | { |
478 | int mlen; |
479 | uint64_t sum, partial; |
480 | unsigned int final_acc; |
481 | uint8_t *data; |
482 | boolean_t needs_swap, started_on_odd; |
483 | |
484 | VERIFY(len >= 0); |
485 | VERIFY(off >= 0); |
486 | |
487 | needs_swap = FALSE; |
488 | started_on_odd = FALSE; |
489 | sum = initial_sum; |
490 | |
491 | for (;;) { |
492 | if (__improbable(m == NULL)) { |
493 | CKSUM_ERR("%s: out of data\n" , __func__); |
494 | return (uint32_t)-1; |
495 | } |
496 | mlen = m->m_len; |
497 | if (mlen > off) { |
498 | mlen -= off; |
499 | data = mtod(m, uint8_t *) + off; |
500 | goto post_initial_offset; |
501 | } |
502 | off -= mlen; |
503 | if (len == 0) { |
504 | break; |
505 | } |
506 | m = m->m_next; |
507 | } |
508 | |
509 | for (; len > 0; m = m->m_next) { |
510 | if (__improbable(m == NULL)) { |
511 | CKSUM_ERR("%s: out of data\n" , __func__); |
512 | return (uint32_t)-1; |
513 | } |
514 | mlen = m->m_len; |
515 | data = mtod(m, uint8_t *); |
516 | post_initial_offset: |
517 | if (mlen == 0) { |
518 | continue; |
519 | } |
520 | if (mlen > len) { |
521 | mlen = len; |
522 | } |
523 | len -= mlen; |
524 | |
525 | partial = 0; |
526 | if ((uintptr_t)data & 1) { |
527 | /* Align on word boundary */ |
528 | started_on_odd = !started_on_odd; |
529 | #if BYTE_ORDER == LITTLE_ENDIAN |
530 | partial = *data << 8; |
531 | #else /* BYTE_ORDER != LITTLE_ENDIAN */ |
532 | partial = *data; |
533 | #endif /* BYTE_ORDER != LITTLE_ENDIAN */ |
534 | ++data; |
535 | --mlen; |
536 | } |
537 | needs_swap = started_on_odd; |
538 | if ((uintptr_t)data & 2) { |
539 | if (mlen < 2) { |
540 | goto trailing_bytes; |
541 | } |
542 | partial += *(uint16_t *)(void *)data; |
543 | data += 2; |
544 | mlen -= 2; |
545 | } |
546 | while (mlen >= 64) { |
547 | __builtin_prefetch(data + 32); |
548 | __builtin_prefetch(data + 64); |
549 | partial += *(uint32_t *)(void *)data; |
550 | partial += *(uint32_t *)(void *)(data + 4); |
551 | partial += *(uint32_t *)(void *)(data + 8); |
552 | partial += *(uint32_t *)(void *)(data + 12); |
553 | partial += *(uint32_t *)(void *)(data + 16); |
554 | partial += *(uint32_t *)(void *)(data + 20); |
555 | partial += *(uint32_t *)(void *)(data + 24); |
556 | partial += *(uint32_t *)(void *)(data + 28); |
557 | partial += *(uint32_t *)(void *)(data + 32); |
558 | partial += *(uint32_t *)(void *)(data + 36); |
559 | partial += *(uint32_t *)(void *)(data + 40); |
560 | partial += *(uint32_t *)(void *)(data + 44); |
561 | partial += *(uint32_t *)(void *)(data + 48); |
562 | partial += *(uint32_t *)(void *)(data + 52); |
563 | partial += *(uint32_t *)(void *)(data + 56); |
564 | partial += *(uint32_t *)(void *)(data + 60); |
565 | data += 64; |
566 | mlen -= 64; |
567 | if (__improbable(partial & (3ULL << 62))) { |
568 | if (needs_swap) { |
569 | partial = (partial << 8) + |
570 | (partial >> 56); |
571 | } |
572 | sum += (partial >> 32); |
573 | sum += (partial & 0xffffffff); |
574 | partial = 0; |
575 | } |
576 | } |
577 | /* |
578 | * mlen is not updated below as the remaining tests |
579 | * are using bit masks, which are not affected. |
580 | */ |
581 | if (mlen & 32) { |
582 | partial += *(uint32_t *)(void *)data; |
583 | partial += *(uint32_t *)(void *)(data + 4); |
584 | partial += *(uint32_t *)(void *)(data + 8); |
585 | partial += *(uint32_t *)(void *)(data + 12); |
586 | partial += *(uint32_t *)(void *)(data + 16); |
587 | partial += *(uint32_t *)(void *)(data + 20); |
588 | partial += *(uint32_t *)(void *)(data + 24); |
589 | partial += *(uint32_t *)(void *)(data + 28); |
590 | data += 32; |
591 | } |
592 | if (mlen & 16) { |
593 | partial += *(uint32_t *)(void *)data; |
594 | partial += *(uint32_t *)(void *)(data + 4); |
595 | partial += *(uint32_t *)(void *)(data + 8); |
596 | partial += *(uint32_t *)(void *)(data + 12); |
597 | data += 16; |
598 | } |
599 | if (mlen & 8) { |
600 | partial += *(uint32_t *)(void *)data; |
601 | partial += *(uint32_t *)(void *)(data + 4); |
602 | data += 8; |
603 | } |
604 | if (mlen & 4) { |
605 | partial += *(uint32_t *)(void *)data; |
606 | data += 4; |
607 | } |
608 | if (mlen & 2) { |
609 | partial += *(uint16_t *)(void *)data; |
610 | data += 2; |
611 | } |
612 | trailing_bytes: |
613 | if (mlen & 1) { |
614 | #if BYTE_ORDER == LITTLE_ENDIAN |
615 | partial += *data; |
616 | #else /* BYTE_ORDER != LITTLE_ENDIAN */ |
617 | partial += *data << 8; |
618 | #endif /* BYTE_ORDER != LITTLE_ENDIAN */ |
619 | started_on_odd = !started_on_odd; |
620 | } |
621 | |
622 | if (needs_swap) { |
623 | partial = (partial << 8) + (partial >> 56); |
624 | } |
625 | sum += (partial >> 32) + (partial & 0xffffffff); |
626 | /* |
627 | * Reduce sum to allow potential byte swap |
628 | * in the next iteration without carry. |
629 | */ |
630 | sum = (sum >> 32) + (sum & 0xffffffff); |
631 | } |
632 | final_acc = (sum >> 48) + ((sum >> 32) & 0xffff) + |
633 | ((sum >> 16) & 0xffff) + (sum & 0xffff); |
634 | final_acc = (final_acc >> 16) + (final_acc & 0xffff); |
635 | final_acc = (final_acc >> 16) + (final_acc & 0xffff); |
636 | return final_acc & 0xffff; |
637 | } |
638 | #endif /* __LP64 */ |
639 | #endif /* DEBUG || DEVELOPMENT */ |
640 | |