- Fix the stupid mess we created when making this from the cmake branch
[reactos.git] / lib / drivers / lwip / src / core / ipv4 / inet_chksum.c
1 /**
2 * @file
3 * Incluse internet checksum functions.
4 *
5 */
6
7 /*
8 * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
9 * All rights reserved.
10 *
11 * Redistribution and use in source and binary forms, with or without modification,
12 * are permitted provided that the following conditions are met:
13 *
14 * 1. Redistributions of source code must retain the above copyright notice,
15 * this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright notice,
17 * this list of conditions and the following disclaimer in the documentation
18 * and/or other materials provided with the distribution.
19 * 3. The name of the author may not be used to endorse or promote products
20 * derived from this software without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
23 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
24 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
25 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
26 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
27 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
28 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
29 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
30 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
31 * OF SUCH DAMAGE.
32 *
33 * This file is part of the lwIP TCP/IP stack.
34 *
35 * Author: Adam Dunkels <adam@sics.se>
36 *
37 */
38
39 #include "lwip/opt.h"
40
41 #include "lwip/inet_chksum.h"
42 #include "lwip/def.h"
43
44 #include <stddef.h>
45 #include <string.h>
46
47 /* These are some reference implementations of the checksum algorithm, with the
48 * aim of being simple, correct and fully portable. Checksumming is the
49 * first thing you would want to optimize for your platform. If you create
50 * your own version, link it in and in your cc.h put:
51 *
52 * #define LWIP_CHKSUM <your_checksum_routine>
53 *
54 * Or you can select from the implementations below by defining
55 * LWIP_CHKSUM_ALGORITHM to 1, 2 or 3.
56 */
57
58 #ifndef LWIP_CHKSUM
59 # define LWIP_CHKSUM lwip_standard_chksum
60 # ifndef LWIP_CHKSUM_ALGORITHM
61 # define LWIP_CHKSUM_ALGORITHM 2
62 # endif
63 #endif
64 /* If none set: */
65 #ifndef LWIP_CHKSUM_ALGORITHM
66 # define LWIP_CHKSUM_ALGORITHM 0
67 #endif
68
69 #if (LWIP_CHKSUM_ALGORITHM == 1) /* Version #1 */
70 /**
71 * lwip checksum
72 *
73 * @param dataptr points to start of data to be summed at any boundary
74 * @param len length of data to be summed
75 * @return host order (!) lwip checksum (non-inverted Internet sum)
76 *
77 * @note accumulator size limits summable length to 64k
78 * @note host endianess is irrelevant (p3 RFC1071)
79 */
80 static u16_t
81 lwip_standard_chksum(void *dataptr, u16_t len)
82 {
83 u32_t acc;
84 u16_t src;
85 u8_t *octetptr;
86
87 acc = 0;
88 /* dataptr may be at odd or even addresses */
89 octetptr = (u8_t*)dataptr;
90 while (len > 1) {
91 /* declare first octet as most significant
92 thus assume network order, ignoring host order */
93 src = (*octetptr) << 8;
94 octetptr++;
95 /* declare second octet as least significant */
96 src |= (*octetptr);
97 octetptr++;
98 acc += src;
99 len -= 2;
100 }
101 if (len > 0) {
102 /* accumulate remaining octet */
103 src = (*octetptr) << 8;
104 acc += src;
105 }
106 /* add deferred carry bits */
107 acc = (acc >> 16) + (acc & 0x0000ffffUL);
108 if ((acc & 0xffff0000UL) != 0) {
109 acc = (acc >> 16) + (acc & 0x0000ffffUL);
110 }
111 /* This maybe a little confusing: reorder sum using htons()
112 instead of ntohs() since it has a little less call overhead.
113 The caller must invert bits for Internet sum ! */
114 return htons((u16_t)acc);
115 }
116 #endif
117
118 #if (LWIP_CHKSUM_ALGORITHM == 2) /* Alternative version #2 */
119 /*
120 * Curt McDowell
121 * Broadcom Corp.
122 * csm@broadcom.com
123 *
124 * IP checksum two bytes at a time with support for
125 * unaligned buffer.
126 * Works for len up to and including 0x20000.
127 * by Curt McDowell, Broadcom Corp. 12/08/2005
128 *
129 * @param dataptr points to start of data to be summed at any boundary
130 * @param len length of data to be summed
131 * @return host order (!) lwip checksum (non-inverted Internet sum)
132 */
133
134 static u16_t
135 lwip_standard_chksum(void *dataptr, int len)
136 {
137 u8_t *pb = (u8_t *)dataptr;
138 u16_t *ps, t = 0;
139 u32_t sum = 0;
140 int odd = ((mem_ptr_t)pb & 1);
141
142 /* Get aligned to u16_t */
143 if (odd && len > 0) {
144 ((u8_t *)&t)[1] = *pb++;
145 len--;
146 }
147
148 /* Add the bulk of the data */
149 ps = (u16_t *)(void *)pb;
150 while (len > 1) {
151 sum += *ps++;
152 len -= 2;
153 }
154
155 /* Consume left-over byte, if any */
156 if (len > 0) {
157 ((u8_t *)&t)[0] = *(u8_t *)ps;
158 }
159
160 /* Add end bytes */
161 sum += t;
162
163 /* Fold 32-bit sum to 16 bits
164 calling this twice is propably faster than if statements... */
165 sum = FOLD_U32T(sum);
166 sum = FOLD_U32T(sum);
167
168 /* Swap if alignment was odd */
169 if (odd) {
170 sum = SWAP_BYTES_IN_WORD(sum);
171 }
172
173 return (u16_t)sum;
174 }
175 #endif
176
177 #if (LWIP_CHKSUM_ALGORITHM == 3) /* Alternative version #3 */
178 /**
179 * An optimized checksum routine. Basically, it uses loop-unrolling on
180 * the checksum loop, treating the head and tail bytes specially, whereas
181 * the inner loop acts on 8 bytes at a time.
182 *
183 * @arg start of buffer to be checksummed. May be an odd byte address.
184 * @len number of bytes in the buffer to be checksummed.
185 * @return host order (!) lwip checksum (non-inverted Internet sum)
186 *
187 * by Curt McDowell, Broadcom Corp. December 8th, 2005
188 */
189
190 static u16_t
191 lwip_standard_chksum(void *dataptr, int len)
192 {
193 u8_t *pb = (u8_t *)dataptr;
194 u16_t *ps, t = 0;
195 u32_t *pl;
196 u32_t sum = 0, tmp;
197 /* starts at odd byte address? */
198 int odd = ((mem_ptr_t)pb & 1);
199
200 if (odd && len > 0) {
201 ((u8_t *)&t)[1] = *pb++;
202 len--;
203 }
204
205 ps = (u16_t *)pb;
206
207 if (((mem_ptr_t)ps & 3) && len > 1) {
208 sum += *ps++;
209 len -= 2;
210 }
211
212 pl = (u32_t *)ps;
213
214 while (len > 7) {
215 tmp = sum + *pl++; /* ping */
216 if (tmp < sum) {
217 tmp++; /* add back carry */
218 }
219
220 sum = tmp + *pl++; /* pong */
221 if (sum < tmp) {
222 sum++; /* add back carry */
223 }
224
225 len -= 8;
226 }
227
228 /* make room in upper bits */
229 sum = FOLD_U32T(sum);
230
231 ps = (u16_t *)pl;
232
233 /* 16-bit aligned word remaining? */
234 while (len > 1) {
235 sum += *ps++;
236 len -= 2;
237 }
238
239 /* dangling tail byte remaining? */
240 if (len > 0) { /* include odd byte */
241 ((u8_t *)&t)[0] = *(u8_t *)ps;
242 }
243
244 sum += t; /* add end bytes */
245
246 /* Fold 32-bit sum to 16 bits
247 calling this twice is propably faster than if statements... */
248 sum = FOLD_U32T(sum);
249 sum = FOLD_U32T(sum);
250
251 if (odd) {
252 sum = SWAP_BYTES_IN_WORD(sum);
253 }
254
255 return (u16_t)sum;
256 }
257 #endif
258
259 /* inet_chksum_pseudo:
260 *
261 * Calculates the pseudo Internet checksum used by TCP and UDP for a pbuf chain.
262 * IP addresses are expected to be in network byte order.
263 *
264 * @param p chain of pbufs over that a checksum should be calculated (ip data part)
265 * @param src source ip address (used for checksum of pseudo header)
266 * @param dst destination ip address (used for checksum of pseudo header)
267 * @param proto ip protocol (used for checksum of pseudo header)
268 * @param proto_len length of the ip data part (used for checksum of pseudo header)
269 * @return checksum (as u16_t) to be saved directly in the protocol header
270 */
271 u16_t
272 inet_chksum_pseudo(struct pbuf *p,
273 ip_addr_t *src, ip_addr_t *dest,
274 u8_t proto, u16_t proto_len)
275 {
276 u32_t acc;
277 u32_t addr;
278 struct pbuf *q;
279 u8_t swapped;
280
281 acc = 0;
282 swapped = 0;
283 /* iterate through all pbuf in chain */
284 for(q = p; q != NULL; q = q->next) {
285 LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): checksumming pbuf %p (has next %p) \n",
286 (void *)q, (void *)q->next));
287 acc += LWIP_CHKSUM(q->payload, q->len);
288 /*LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): unwrapped lwip_chksum()=%"X32_F" \n", acc));*/
289 /* just executing this next line is probably faster that the if statement needed
290 to check whether we really need to execute it, and does no harm */
291 acc = FOLD_U32T(acc);
292 if (q->len % 2 != 0) {
293 swapped = 1 - swapped;
294 acc = SWAP_BYTES_IN_WORD(acc);
295 }
296 /*LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): wrapped lwip_chksum()=%"X32_F" \n", acc));*/
297 }
298
299 if (swapped) {
300 acc = SWAP_BYTES_IN_WORD(acc);
301 }
302 addr = ip4_addr_get_u32(src);
303 acc += (addr & 0xffffUL);
304 acc += ((addr >> 16) & 0xffffUL);
305 addr = ip4_addr_get_u32(dest);
306 acc += (addr & 0xffffUL);
307 acc += ((addr >> 16) & 0xffffUL);
308 acc += (u32_t)htons((u16_t)proto);
309 acc += (u32_t)htons(proto_len);
310
311 /* Fold 32-bit sum to 16 bits
312 calling this twice is propably faster than if statements... */
313 acc = FOLD_U32T(acc);
314 acc = FOLD_U32T(acc);
315 LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): pbuf chain lwip_chksum()=%"X32_F"\n", acc));
316 return (u16_t)~(acc & 0xffffUL);
317 }
318
319 /* inet_chksum_pseudo:
320 *
321 * Calculates the pseudo Internet checksum used by TCP and UDP for a pbuf chain.
322 * IP addresses are expected to be in network byte order.
323 *
324 * @param p chain of pbufs over that a checksum should be calculated (ip data part)
325 * @param src source ip address (used for checksum of pseudo header)
326 * @param dst destination ip address (used for checksum of pseudo header)
327 * @param proto ip protocol (used for checksum of pseudo header)
328 * @param proto_len length of the ip data part (used for checksum of pseudo header)
329 * @return checksum (as u16_t) to be saved directly in the protocol header
330 */
331 u16_t
332 inet_chksum_pseudo_partial(struct pbuf *p,
333 ip_addr_t *src, ip_addr_t *dest,
334 u8_t proto, u16_t proto_len, u16_t chksum_len)
335 {
336 u32_t acc;
337 u32_t addr;
338 struct pbuf *q;
339 u8_t swapped;
340 u16_t chklen;
341
342 acc = 0;
343 swapped = 0;
344 /* iterate through all pbuf in chain */
345 for(q = p; (q != NULL) && (chksum_len > 0); q = q->next) {
346 LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): checksumming pbuf %p (has next %p) \n",
347 (void *)q, (void *)q->next));
348 chklen = q->len;
349 if (chklen > chksum_len) {
350 chklen = chksum_len;
351 }
352 acc += LWIP_CHKSUM(q->payload, chklen);
353 chksum_len -= chklen;
354 LWIP_ASSERT("delete me", chksum_len < 0x7fff);
355 /*LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): unwrapped lwip_chksum()=%"X32_F" \n", acc));*/
356 /* fold the upper bit down */
357 acc = FOLD_U32T(acc);
358 if (q->len % 2 != 0) {
359 swapped = 1 - swapped;
360 acc = SWAP_BYTES_IN_WORD(acc);
361 }
362 /*LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): wrapped lwip_chksum()=%"X32_F" \n", acc));*/
363 }
364
365 if (swapped) {
366 acc = SWAP_BYTES_IN_WORD(acc);
367 }
368 addr = ip4_addr_get_u32(src);
369 acc += (addr & 0xffffUL);
370 acc += ((addr >> 16) & 0xffffUL);
371 addr = ip4_addr_get_u32(dest);
372 acc += (addr & 0xffffUL);
373 acc += ((addr >> 16) & 0xffffUL);
374 acc += (u32_t)htons((u16_t)proto);
375 acc += (u32_t)htons(proto_len);
376
377 /* Fold 32-bit sum to 16 bits
378 calling this twice is propably faster than if statements... */
379 acc = FOLD_U32T(acc);
380 acc = FOLD_U32T(acc);
381 LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): pbuf chain lwip_chksum()=%"X32_F"\n", acc));
382 return (u16_t)~(acc & 0xffffUL);
383 }
384
385 /* inet_chksum:
386 *
387 * Calculates the Internet checksum over a portion of memory. Used primarily for IP
388 * and ICMP.
389 *
390 * @param dataptr start of the buffer to calculate the checksum (no alignment needed)
391 * @param len length of the buffer to calculate the checksum
392 * @return checksum (as u16_t) to be saved directly in the protocol header
393 */
394
395 u16_t
396 inet_chksum(void *dataptr, u16_t len)
397 {
398 return ~LWIP_CHKSUM(dataptr, len);
399 }
400
401 /**
402 * Calculate a checksum over a chain of pbufs (without pseudo-header, much like
403 * inet_chksum only pbufs are used).
404 *
405 * @param p pbuf chain over that the checksum should be calculated
406 * @return checksum (as u16_t) to be saved directly in the protocol header
407 */
408 u16_t
409 inet_chksum_pbuf(struct pbuf *p)
410 {
411 u32_t acc;
412 struct pbuf *q;
413 u8_t swapped;
414
415 acc = 0;
416 swapped = 0;
417 for(q = p; q != NULL; q = q->next) {
418 acc += LWIP_CHKSUM(q->payload, q->len);
419 acc = FOLD_U32T(acc);
420 if (q->len % 2 != 0) {
421 swapped = 1 - swapped;
422 acc = SWAP_BYTES_IN_WORD(acc);
423 }
424 }
425
426 if (swapped) {
427 acc = SWAP_BYTES_IN_WORD(acc);
428 }
429 return (u16_t)~(acc & 0xffffUL);
430 }
431
432 /* These are some implementations for LWIP_CHKSUM_COPY, which copies data
433 * like MEMCPY but generates a checksum at the same time. Since this is a
434 * performance-sensitive function, you might want to create your own version
435 * in assembly targeted at your hardware by defining it in lwipopts.h:
436 * #define LWIP_CHKSUM_COPY(dst, src, len) your_chksum_copy(dst, src, len)
437 */
438
439 #if (LWIP_CHKSUM_COPY_ALGORITHM == 1) /* Version #1 */
440 /** Safe but slow: first call MEMCPY, then call LWIP_CHKSUM.
441 * For architectures with big caches, data might still be in cache when
442 * generating the checksum after copying.
443 */
444 u16_t
445 lwip_chksum_copy(void *dst, const void *src, u16_t len)
446 {
447 MEMCPY(dst, src, len);
448 return LWIP_CHKSUM(dst, len);
449 }
450 #endif /* (LWIP_CHKSUM_COPY_ALGORITHM == 1) */