Pascal Nysten / lwip

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Dependencies:   DebugLib

Dependents:   LoRaWAN-lmic-app LoRaWAN-lmic-app LoRaWAN-test-10secs LoRaPersonalizedDeviceForEverynet ... more

Fork of lwip_ppp_ethernet by Donatien Garnier

src/core/ipv4/inet_chksum.c@3:a9e6ba815945, 2015-11-20 (annotated)

Committer:
pnysten
Date:
Fri Nov 20 12:30:58 2015 +0000
Revision:
3:a9e6ba815945
Parent:
0:8e01dca41002 
Adapted to Nucleo, LoRa Semtech

Who changed what in which revision?

UserRevisionLine numberNew contents of line
donatien 0:8e01dca41002 1 /**
donatien 0:8e01dca41002 2 * @file
donatien 0:8e01dca41002 3 * Incluse internet checksum functions.
donatien 0:8e01dca41002 4 *
donatien 0:8e01dca41002 5 */
donatien 0:8e01dca41002 6
donatien 0:8e01dca41002 7 /*
donatien 0:8e01dca41002 8 * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
donatien 0:8e01dca41002 9 * All rights reserved.
donatien 0:8e01dca41002 10 *
donatien 0:8e01dca41002 11 * Redistribution and use in source and binary forms, with or without modification,
donatien 0:8e01dca41002 12 * are permitted provided that the following conditions are met:
donatien 0:8e01dca41002 13 *
donatien 0:8e01dca41002 14 * 1. Redistributions of source code must retain the above copyright notice,
donatien 0:8e01dca41002 15 * this list of conditions and the following disclaimer.
donatien 0:8e01dca41002 16 * 2. Redistributions in binary form must reproduce the above copyright notice,
donatien 0:8e01dca41002 17 * this list of conditions and the following disclaimer in the documentation
donatien 0:8e01dca41002 18 * and/or other materials provided with the distribution.
donatien 0:8e01dca41002 19 * 3. The name of the author may not be used to endorse or promote products
donatien 0:8e01dca41002 20 * derived from this software without specific prior written permission.
donatien 0:8e01dca41002 21 *
donatien 0:8e01dca41002 22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
donatien 0:8e01dca41002 23 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
donatien 0:8e01dca41002 24 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
donatien 0:8e01dca41002 25 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
donatien 0:8e01dca41002 26 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
donatien 0:8e01dca41002 27 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
donatien 0:8e01dca41002 28 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
donatien 0:8e01dca41002 29 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
donatien 0:8e01dca41002 30 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
donatien 0:8e01dca41002 31 * OF SUCH DAMAGE.
donatien 0:8e01dca41002 32 *
donatien 0:8e01dca41002 33 * This file is part of the lwIP TCP/IP stack.
donatien 0:8e01dca41002 34 *
donatien 0:8e01dca41002 35 * Author: Adam Dunkels <adam@sics.se>
donatien 0:8e01dca41002 36 *
donatien 0:8e01dca41002 37 */
donatien 0:8e01dca41002 38
donatien 0:8e01dca41002 39 #include "lwip/opt.h"
donatien 0:8e01dca41002 40
donatien 0:8e01dca41002 41 #include "lwip/inet_chksum.h"
donatien 0:8e01dca41002 42 #include "lwip/def.h"
donatien 0:8e01dca41002 43
donatien 0:8e01dca41002 44 #include <stddef.h>
donatien 0:8e01dca41002 45 #include <string.h>
donatien 0:8e01dca41002 46
donatien 0:8e01dca41002 47 /* These are some reference implementations of the checksum algorithm, with the
donatien 0:8e01dca41002 48 * aim of being simple, correct and fully portable. Checksumming is the
donatien 0:8e01dca41002 49 * first thing you would want to optimize for your platform. If you create
donatien 0:8e01dca41002 50 * your own version, link it in and in your cc.h put:
donatien 0:8e01dca41002 51 *
donatien 0:8e01dca41002 52 * #define LWIP_CHKSUM <your_checksum_routine>
donatien 0:8e01dca41002 53 *
donatien 0:8e01dca41002 54 * Or you can select from the implementations below by defining
donatien 0:8e01dca41002 55 * LWIP_CHKSUM_ALGORITHM to 1, 2 or 3.
donatien 0:8e01dca41002 56 */
donatien 0:8e01dca41002 57
donatien 0:8e01dca41002 58 #ifndef LWIP_CHKSUM
donatien 0:8e01dca41002 59 # define LWIP_CHKSUM lwip_standard_chksum
donatien 0:8e01dca41002 60 # ifndef LWIP_CHKSUM_ALGORITHM
donatien 0:8e01dca41002 61 # define LWIP_CHKSUM_ALGORITHM 2
donatien 0:8e01dca41002 62 # endif
donatien 0:8e01dca41002 63 #endif
donatien 0:8e01dca41002 64 /* If none set: */
donatien 0:8e01dca41002 65 #ifndef LWIP_CHKSUM_ALGORITHM
donatien 0:8e01dca41002 66 # define LWIP_CHKSUM_ALGORITHM 0
donatien 0:8e01dca41002 67 #endif
donatien 0:8e01dca41002 68
donatien 0:8e01dca41002 69 #if (LWIP_CHKSUM_ALGORITHM == 1) /* Version #1 */
donatien 0:8e01dca41002 70 /**
donatien 0:8e01dca41002 71 * lwip checksum
donatien 0:8e01dca41002 72 *
donatien 0:8e01dca41002 73 * @param dataptr points to start of data to be summed at any boundary
donatien 0:8e01dca41002 74 * @param len length of data to be summed
donatien 0:8e01dca41002 75 * @return host order (!) lwip checksum (non-inverted Internet sum)
donatien 0:8e01dca41002 76 *
donatien 0:8e01dca41002 77 * @note accumulator size limits summable length to 64k
donatien 0:8e01dca41002 78 * @note host endianess is irrelevant (p3 RFC1071)
donatien 0:8e01dca41002 79 */
donatien 0:8e01dca41002 80 static u16_t
donatien 0:8e01dca41002 81 lwip_standard_chksum(void *dataptr, u16_t len)
donatien 0:8e01dca41002 82 {
donatien 0:8e01dca41002 83 u32_t acc;
donatien 0:8e01dca41002 84 u16_t src;
donatien 0:8e01dca41002 85 u8_t *octetptr;
donatien 0:8e01dca41002 86
donatien 0:8e01dca41002 87 acc = 0;
donatien 0:8e01dca41002 88 /* dataptr may be at odd or even addresses */
donatien 0:8e01dca41002 89 octetptr = (u8_t*)dataptr;
donatien 0:8e01dca41002 90 while (len > 1) {
donatien 0:8e01dca41002 91 /* declare first octet as most significant
donatien 0:8e01dca41002 92 thus assume network order, ignoring host order */
donatien 0:8e01dca41002 93 src = (*octetptr) << 8;
donatien 0:8e01dca41002 94 octetptr++;
donatien 0:8e01dca41002 95 /* declare second octet as least significant */
donatien 0:8e01dca41002 96 src |= (*octetptr);
donatien 0:8e01dca41002 97 octetptr++;
donatien 0:8e01dca41002 98 acc += src;
donatien 0:8e01dca41002 99 len -= 2;
donatien 0:8e01dca41002 100 }
donatien 0:8e01dca41002 101 if (len > 0) {
donatien 0:8e01dca41002 102 /* accumulate remaining octet */
donatien 0:8e01dca41002 103 src = (*octetptr) << 8;
donatien 0:8e01dca41002 104 acc += src;
donatien 0:8e01dca41002 105 }
donatien 0:8e01dca41002 106 /* add deferred carry bits */
donatien 0:8e01dca41002 107 acc = (acc >> 16) + (acc & 0x0000ffffUL);
donatien 0:8e01dca41002 108 if ((acc & 0xffff0000UL) != 0) {
donatien 0:8e01dca41002 109 acc = (acc >> 16) + (acc & 0x0000ffffUL);
donatien 0:8e01dca41002 110 }
donatien 0:8e01dca41002 111 /* This maybe a little confusing: reorder sum using htons()
donatien 0:8e01dca41002 112 instead of ntohs() since it has a little less call overhead.
donatien 0:8e01dca41002 113 The caller must invert bits for Internet sum ! */
donatien 0:8e01dca41002 114 return htons((u16_t)acc);
donatien 0:8e01dca41002 115 }
donatien 0:8e01dca41002 116 #endif
donatien 0:8e01dca41002 117
donatien 0:8e01dca41002 118 #if (LWIP_CHKSUM_ALGORITHM == 2) /* Alternative version #2 */
donatien 0:8e01dca41002 119 /*
donatien 0:8e01dca41002 120 * Curt McDowell
donatien 0:8e01dca41002 121 * Broadcom Corp.
donatien 0:8e01dca41002 122 * csm@broadcom.com
donatien 0:8e01dca41002 123 *
donatien 0:8e01dca41002 124 * IP checksum two bytes at a time with support for
donatien 0:8e01dca41002 125 * unaligned buffer.
donatien 0:8e01dca41002 126 * Works for len up to and including 0x20000.
donatien 0:8e01dca41002 127 * by Curt McDowell, Broadcom Corp. 12/08/2005
donatien 0:8e01dca41002 128 *
donatien 0:8e01dca41002 129 * @param dataptr points to start of data to be summed at any boundary
donatien 0:8e01dca41002 130 * @param len length of data to be summed
donatien 0:8e01dca41002 131 * @return host order (!) lwip checksum (non-inverted Internet sum)
donatien 0:8e01dca41002 132 */
donatien 0:8e01dca41002 133
donatien 0:8e01dca41002 134 static u16_t
donatien 0:8e01dca41002 135 lwip_standard_chksum(void *dataptr, int len)
donatien 0:8e01dca41002 136 {
donatien 0:8e01dca41002 137 u8_t *pb = (u8_t *)dataptr;
donatien 0:8e01dca41002 138 u16_t *ps, t = 0;
donatien 0:8e01dca41002 139 u32_t sum = 0;
donatien 0:8e01dca41002 140 int odd = ((mem_ptr_t)pb & 1);
donatien 0:8e01dca41002 141
donatien 0:8e01dca41002 142 /* Get aligned to u16_t */
donatien 0:8e01dca41002 143 if (odd && len > 0) {
donatien 0:8e01dca41002 144 ((u8_t *)&t)[1] = *pb++;
donatien 0:8e01dca41002 145 len--;
donatien 0:8e01dca41002 146 }
donatien 0:8e01dca41002 147
donatien 0:8e01dca41002 148 /* Add the bulk of the data */
donatien 0:8e01dca41002 149 ps = (u16_t *)(void *)pb;
donatien 0:8e01dca41002 150 while (len > 1) {
donatien 0:8e01dca41002 151 sum += *ps++;
donatien 0:8e01dca41002 152 len -= 2;
donatien 0:8e01dca41002 153 }
donatien 0:8e01dca41002 154
donatien 0:8e01dca41002 155 /* Consume left-over byte, if any */
donatien 0:8e01dca41002 156 if (len > 0) {
donatien 0:8e01dca41002 157 ((u8_t *)&t)[0] = *(u8_t *)ps;
donatien 0:8e01dca41002 158 }
donatien 0:8e01dca41002 159
donatien 0:8e01dca41002 160 /* Add end bytes */
donatien 0:8e01dca41002 161 sum += t;
donatien 0:8e01dca41002 162
donatien 0:8e01dca41002 163 /* Fold 32-bit sum to 16 bits
donatien 0:8e01dca41002 164 calling this twice is propably faster than if statements... */
donatien 0:8e01dca41002 165 sum = FOLD_U32T(sum);
donatien 0:8e01dca41002 166 sum = FOLD_U32T(sum);
donatien 0:8e01dca41002 167
donatien 0:8e01dca41002 168 /* Swap if alignment was odd */
donatien 0:8e01dca41002 169 if (odd) {
donatien 0:8e01dca41002 170 sum = SWAP_BYTES_IN_WORD(sum);
donatien 0:8e01dca41002 171 }
donatien 0:8e01dca41002 172
donatien 0:8e01dca41002 173 return (u16_t)sum;
donatien 0:8e01dca41002 174 }
donatien 0:8e01dca41002 175 #endif
donatien 0:8e01dca41002 176
donatien 0:8e01dca41002 177 #if (LWIP_CHKSUM_ALGORITHM == 3) /* Alternative version #3 */
donatien 0:8e01dca41002 178 /**
donatien 0:8e01dca41002 179 * An optimized checksum routine. Basically, it uses loop-unrolling on
donatien 0:8e01dca41002 180 * the checksum loop, treating the head and tail bytes specially, whereas
donatien 0:8e01dca41002 181 * the inner loop acts on 8 bytes at a time.
donatien 0:8e01dca41002 182 *
donatien 0:8e01dca41002 183 * @arg start of buffer to be checksummed. May be an odd byte address.
donatien 0:8e01dca41002 184 * @len number of bytes in the buffer to be checksummed.
donatien 0:8e01dca41002 185 * @return host order (!) lwip checksum (non-inverted Internet sum)
donatien 0:8e01dca41002 186 *
donatien 0:8e01dca41002 187 * by Curt McDowell, Broadcom Corp. December 8th, 2005
donatien 0:8e01dca41002 188 */
donatien 0:8e01dca41002 189
donatien 0:8e01dca41002 190 static u16_t
donatien 0:8e01dca41002 191 lwip_standard_chksum(void *dataptr, int len)
donatien 0:8e01dca41002 192 {
donatien 0:8e01dca41002 193 u8_t *pb = (u8_t *)dataptr;
donatien 0:8e01dca41002 194 u16_t *ps, t = 0;
donatien 0:8e01dca41002 195 u32_t *pl;
donatien 0:8e01dca41002 196 u32_t sum = 0, tmp;
donatien 0:8e01dca41002 197 /* starts at odd byte address? */
donatien 0:8e01dca41002 198 int odd = ((mem_ptr_t)pb & 1);
donatien 0:8e01dca41002 199
donatien 0:8e01dca41002 200 if (odd && len > 0) {
donatien 0:8e01dca41002 201 ((u8_t *)&t)[1] = *pb++;
donatien 0:8e01dca41002 202 len--;
donatien 0:8e01dca41002 203 }
donatien 0:8e01dca41002 204
donatien 0:8e01dca41002 205 ps = (u16_t *)pb;
donatien 0:8e01dca41002 206
donatien 0:8e01dca41002 207 if (((mem_ptr_t)ps & 3) && len > 1) {
donatien 0:8e01dca41002 208 sum += *ps++;
donatien 0:8e01dca41002 209 len -= 2;
donatien 0:8e01dca41002 210 }
donatien 0:8e01dca41002 211
donatien 0:8e01dca41002 212 pl = (u32_t *)ps;
donatien 0:8e01dca41002 213
donatien 0:8e01dca41002 214 while (len > 7) {
donatien 0:8e01dca41002 215 tmp = sum + *pl++; /* ping */
donatien 0:8e01dca41002 216 if (tmp < sum) {
donatien 0:8e01dca41002 217 tmp++; /* add back carry */
donatien 0:8e01dca41002 218 }
donatien 0:8e01dca41002 219
donatien 0:8e01dca41002 220 sum = tmp + *pl++; /* pong */
donatien 0:8e01dca41002 221 if (sum < tmp) {
donatien 0:8e01dca41002 222 sum++; /* add back carry */
donatien 0:8e01dca41002 223 }
donatien 0:8e01dca41002 224
donatien 0:8e01dca41002 225 len -= 8;
donatien 0:8e01dca41002 226 }
donatien 0:8e01dca41002 227
donatien 0:8e01dca41002 228 /* make room in upper bits */
donatien 0:8e01dca41002 229 sum = FOLD_U32T(sum);
donatien 0:8e01dca41002 230
donatien 0:8e01dca41002 231 ps = (u16_t *)pl;
donatien 0:8e01dca41002 232
donatien 0:8e01dca41002 233 /* 16-bit aligned word remaining? */
donatien 0:8e01dca41002 234 while (len > 1) {
donatien 0:8e01dca41002 235 sum += *ps++;
donatien 0:8e01dca41002 236 len -= 2;
donatien 0:8e01dca41002 237 }
donatien 0:8e01dca41002 238
donatien 0:8e01dca41002 239 /* dangling tail byte remaining? */
donatien 0:8e01dca41002 240 if (len > 0) { /* include odd byte */
donatien 0:8e01dca41002 241 ((u8_t *)&t)[0] = *(u8_t *)ps;
donatien 0:8e01dca41002 242 }
donatien 0:8e01dca41002 243
donatien 0:8e01dca41002 244 sum += t; /* add end bytes */
donatien 0:8e01dca41002 245
donatien 0:8e01dca41002 246 /* Fold 32-bit sum to 16 bits
donatien 0:8e01dca41002 247 calling this twice is propably faster than if statements... */
donatien 0:8e01dca41002 248 sum = FOLD_U32T(sum);
donatien 0:8e01dca41002 249 sum = FOLD_U32T(sum);
donatien 0:8e01dca41002 250
donatien 0:8e01dca41002 251 if (odd) {
donatien 0:8e01dca41002 252 sum = SWAP_BYTES_IN_WORD(sum);
donatien 0:8e01dca41002 253 }
donatien 0:8e01dca41002 254
donatien 0:8e01dca41002 255 return (u16_t)sum;
donatien 0:8e01dca41002 256 }
donatien 0:8e01dca41002 257 #endif
donatien 0:8e01dca41002 258
donatien 0:8e01dca41002 259 /* inet_chksum_pseudo:
donatien 0:8e01dca41002 260 *
donatien 0:8e01dca41002 261 * Calculates the pseudo Internet checksum used by TCP and UDP for a pbuf chain.
donatien 0:8e01dca41002 262 * IP addresses are expected to be in network byte order.
donatien 0:8e01dca41002 263 *
donatien 0:8e01dca41002 264 * @param p chain of pbufs over that a checksum should be calculated (ip data part)
donatien 0:8e01dca41002 265 * @param src source ip address (used for checksum of pseudo header)
donatien 0:8e01dca41002 266 * @param dst destination ip address (used for checksum of pseudo header)
donatien 0:8e01dca41002 267 * @param proto ip protocol (used for checksum of pseudo header)
donatien 0:8e01dca41002 268 * @param proto_len length of the ip data part (used for checksum of pseudo header)
donatien 0:8e01dca41002 269 * @return checksum (as u16_t) to be saved directly in the protocol header
donatien 0:8e01dca41002 270 */
donatien 0:8e01dca41002 271 u16_t
donatien 0:8e01dca41002 272 inet_chksum_pseudo(struct pbuf *p,
donatien 0:8e01dca41002 273 ip_addr_t *src, ip_addr_t *dest,
donatien 0:8e01dca41002 274 u8_t proto, u16_t proto_len)
donatien 0:8e01dca41002 275 {
donatien 0:8e01dca41002 276 u32_t acc;
donatien 0:8e01dca41002 277 u32_t addr;
donatien 0:8e01dca41002 278 struct pbuf *q;
donatien 0:8e01dca41002 279 u8_t swapped;
donatien 0:8e01dca41002 280
donatien 0:8e01dca41002 281 acc = 0;
donatien 0:8e01dca41002 282 swapped = 0;
donatien 0:8e01dca41002 283 /* iterate through all pbuf in chain */
donatien 0:8e01dca41002 284 for(q = p; q != NULL; q = q->next) {
donatien 0:8e01dca41002 285 LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): checksumming pbuf %p (has next %p) \n",
donatien 0:8e01dca41002 286 (void *)q, (void *)q->next));
donatien 0:8e01dca41002 287 acc += LWIP_CHKSUM(q->payload, q->len);
donatien 0:8e01dca41002 288 /*LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): unwrapped lwip_chksum()=%"X32_F" \n", acc));*/
donatien 0:8e01dca41002 289 /* just executing this next line is probably faster that the if statement needed
donatien 0:8e01dca41002 290 to check whether we really need to execute it, and does no harm */
donatien 0:8e01dca41002 291 acc = FOLD_U32T(acc);
donatien 0:8e01dca41002 292 if (q->len % 2 != 0) {
donatien 0:8e01dca41002 293 swapped = 1 - swapped;
donatien 0:8e01dca41002 294 acc = SWAP_BYTES_IN_WORD(acc);
donatien 0:8e01dca41002 295 }
donatien 0:8e01dca41002 296 /*LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): wrapped lwip_chksum()=%"X32_F" \n", acc));*/
donatien 0:8e01dca41002 297 }
donatien 0:8e01dca41002 298
donatien 0:8e01dca41002 299 if (swapped) {
donatien 0:8e01dca41002 300 acc = SWAP_BYTES_IN_WORD(acc);
donatien 0:8e01dca41002 301 }
donatien 0:8e01dca41002 302 addr = ip4_addr_get_u32(src);
donatien 0:8e01dca41002 303 acc += (addr & 0xffffUL);
donatien 0:8e01dca41002 304 acc += ((addr >> 16) & 0xffffUL);
donatien 0:8e01dca41002 305 addr = ip4_addr_get_u32(dest);
donatien 0:8e01dca41002 306 acc += (addr & 0xffffUL);
donatien 0:8e01dca41002 307 acc += ((addr >> 16) & 0xffffUL);
donatien 0:8e01dca41002 308 acc += (u32_t)htons((u16_t)proto);
donatien 0:8e01dca41002 309 acc += (u32_t)htons(proto_len);
donatien 0:8e01dca41002 310
donatien 0:8e01dca41002 311 /* Fold 32-bit sum to 16 bits
donatien 0:8e01dca41002 312 calling this twice is propably faster than if statements... */
donatien 0:8e01dca41002 313 acc = FOLD_U32T(acc);
donatien 0:8e01dca41002 314 acc = FOLD_U32T(acc);
donatien 0:8e01dca41002 315 LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): pbuf chain lwip_chksum()=%"X32_F"\n", acc));
donatien 0:8e01dca41002 316 return (u16_t)~(acc & 0xffffUL);
donatien 0:8e01dca41002 317 }
donatien 0:8e01dca41002 318
donatien 0:8e01dca41002 319 /* inet_chksum_pseudo:
donatien 0:8e01dca41002 320 *
donatien 0:8e01dca41002 321 * Calculates the pseudo Internet checksum used by TCP and UDP for a pbuf chain.
donatien 0:8e01dca41002 322 * IP addresses are expected to be in network byte order.
donatien 0:8e01dca41002 323 *
donatien 0:8e01dca41002 324 * @param p chain of pbufs over that a checksum should be calculated (ip data part)
donatien 0:8e01dca41002 325 * @param src source ip address (used for checksum of pseudo header)
donatien 0:8e01dca41002 326 * @param dst destination ip address (used for checksum of pseudo header)
donatien 0:8e01dca41002 327 * @param proto ip protocol (used for checksum of pseudo header)
donatien 0:8e01dca41002 328 * @param proto_len length of the ip data part (used for checksum of pseudo header)
donatien 0:8e01dca41002 329 * @return checksum (as u16_t) to be saved directly in the protocol header
donatien 0:8e01dca41002 330 */
donatien 0:8e01dca41002 331 u16_t
donatien 0:8e01dca41002 332 inet_chksum_pseudo_partial(struct pbuf *p,
donatien 0:8e01dca41002 333 ip_addr_t *src, ip_addr_t *dest,
donatien 0:8e01dca41002 334 u8_t proto, u16_t proto_len, u16_t chksum_len)
donatien 0:8e01dca41002 335 {
donatien 0:8e01dca41002 336 u32_t acc;
donatien 0:8e01dca41002 337 u32_t addr;
donatien 0:8e01dca41002 338 struct pbuf *q;
donatien 0:8e01dca41002 339 u8_t swapped;
donatien 0:8e01dca41002 340 u16_t chklen;
donatien 0:8e01dca41002 341
donatien 0:8e01dca41002 342 acc = 0;
donatien 0:8e01dca41002 343 swapped = 0;
donatien 0:8e01dca41002 344 /* iterate through all pbuf in chain */
donatien 0:8e01dca41002 345 for(q = p; (q != NULL) && (chksum_len > 0); q = q->next) {
donatien 0:8e01dca41002 346 LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): checksumming pbuf %p (has next %p) \n",
donatien 0:8e01dca41002 347 (void *)q, (void *)q->next));
donatien 0:8e01dca41002 348 chklen = q->len;
donatien 0:8e01dca41002 349 if (chklen > chksum_len) {
donatien 0:8e01dca41002 350 chklen = chksum_len;
donatien 0:8e01dca41002 351 }
donatien 0:8e01dca41002 352 acc += LWIP_CHKSUM(q->payload, chklen);
donatien 0:8e01dca41002 353 chksum_len -= chklen;
donatien 0:8e01dca41002 354 LWIP_ASSERT("delete me", chksum_len < 0x7fff);
donatien 0:8e01dca41002 355 /*LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): unwrapped lwip_chksum()=%"X32_F" \n", acc));*/
donatien 0:8e01dca41002 356 /* fold the upper bit down */
donatien 0:8e01dca41002 357 acc = FOLD_U32T(acc);
donatien 0:8e01dca41002 358 if (q->len % 2 != 0) {
donatien 0:8e01dca41002 359 swapped = 1 - swapped;
donatien 0:8e01dca41002 360 acc = SWAP_BYTES_IN_WORD(acc);
donatien 0:8e01dca41002 361 }
donatien 0:8e01dca41002 362 /*LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): wrapped lwip_chksum()=%"X32_F" \n", acc));*/
donatien 0:8e01dca41002 363 }
donatien 0:8e01dca41002 364
donatien 0:8e01dca41002 365 if (swapped) {
donatien 0:8e01dca41002 366 acc = SWAP_BYTES_IN_WORD(acc);
donatien 0:8e01dca41002 367 }
donatien 0:8e01dca41002 368 addr = ip4_addr_get_u32(src);
donatien 0:8e01dca41002 369 acc += (addr & 0xffffUL);
donatien 0:8e01dca41002 370 acc += ((addr >> 16) & 0xffffUL);
donatien 0:8e01dca41002 371 addr = ip4_addr_get_u32(dest);
donatien 0:8e01dca41002 372 acc += (addr & 0xffffUL);
donatien 0:8e01dca41002 373 acc += ((addr >> 16) & 0xffffUL);
donatien 0:8e01dca41002 374 acc += (u32_t)htons((u16_t)proto);
donatien 0:8e01dca41002 375 acc += (u32_t)htons(proto_len);
donatien 0:8e01dca41002 376
donatien 0:8e01dca41002 377 /* Fold 32-bit sum to 16 bits
donatien 0:8e01dca41002 378 calling this twice is propably faster than if statements... */
donatien 0:8e01dca41002 379 acc = FOLD_U32T(acc);
donatien 0:8e01dca41002 380 acc = FOLD_U32T(acc);
donatien 0:8e01dca41002 381 LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): pbuf chain lwip_chksum()=%"X32_F"\n", acc));
donatien 0:8e01dca41002 382 return (u16_t)~(acc & 0xffffUL);
donatien 0:8e01dca41002 383 }
donatien 0:8e01dca41002 384
donatien 0:8e01dca41002 385 /* inet_chksum:
donatien 0:8e01dca41002 386 *
donatien 0:8e01dca41002 387 * Calculates the Internet checksum over a portion of memory. Used primarily for IP
donatien 0:8e01dca41002 388 * and ICMP.
donatien 0:8e01dca41002 389 *
donatien 0:8e01dca41002 390 * @param dataptr start of the buffer to calculate the checksum (no alignment needed)
donatien 0:8e01dca41002 391 * @param len length of the buffer to calculate the checksum
donatien 0:8e01dca41002 392 * @return checksum (as u16_t) to be saved directly in the protocol header
donatien 0:8e01dca41002 393 */
donatien 0:8e01dca41002 394
donatien 0:8e01dca41002 395 u16_t
donatien 0:8e01dca41002 396 inet_chksum(void *dataptr, u16_t len)
donatien 0:8e01dca41002 397 {
donatien 0:8e01dca41002 398 return ~LWIP_CHKSUM(dataptr, len);
donatien 0:8e01dca41002 399 }
donatien 0:8e01dca41002 400
donatien 0:8e01dca41002 401 /**
donatien 0:8e01dca41002 402 * Calculate a checksum over a chain of pbufs (without pseudo-header, much like
donatien 0:8e01dca41002 403 * inet_chksum only pbufs are used).
donatien 0:8e01dca41002 404 *
donatien 0:8e01dca41002 405 * @param p pbuf chain over that the checksum should be calculated
donatien 0:8e01dca41002 406 * @return checksum (as u16_t) to be saved directly in the protocol header
donatien 0:8e01dca41002 407 */
donatien 0:8e01dca41002 408 u16_t
donatien 0:8e01dca41002 409 inet_chksum_pbuf(struct pbuf *p)
donatien 0:8e01dca41002 410 {
donatien 0:8e01dca41002 411 u32_t acc;
donatien 0:8e01dca41002 412 struct pbuf *q;
donatien 0:8e01dca41002 413 u8_t swapped;
donatien 0:8e01dca41002 414
donatien 0:8e01dca41002 415 acc = 0;
donatien 0:8e01dca41002 416 swapped = 0;
donatien 0:8e01dca41002 417 for(q = p; q != NULL; q = q->next) {
donatien 0:8e01dca41002 418 acc += LWIP_CHKSUM(q->payload, q->len);
donatien 0:8e01dca41002 419 acc = FOLD_U32T(acc);
donatien 0:8e01dca41002 420 if (q->len % 2 != 0) {
donatien 0:8e01dca41002 421 swapped = 1 - swapped;
donatien 0:8e01dca41002 422 acc = SWAP_BYTES_IN_WORD(acc);
donatien 0:8e01dca41002 423 }
donatien 0:8e01dca41002 424 }
donatien 0:8e01dca41002 425
donatien 0:8e01dca41002 426 if (swapped) {
donatien 0:8e01dca41002 427 acc = SWAP_BYTES_IN_WORD(acc);
donatien 0:8e01dca41002 428 }
donatien 0:8e01dca41002 429 return (u16_t)~(acc & 0xffffUL);
donatien 0:8e01dca41002 430 }
donatien 0:8e01dca41002 431
donatien 0:8e01dca41002 432 /* These are some implementations for LWIP_CHKSUM_COPY, which copies data
donatien 0:8e01dca41002 433 * like MEMCPY but generates a checksum at the same time. Since this is a
donatien 0:8e01dca41002 434 * performance-sensitive function, you might want to create your own version
donatien 0:8e01dca41002 435 * in assembly targeted at your hardware by defining it in lwipopts.h:
donatien 0:8e01dca41002 436 * #define LWIP_CHKSUM_COPY(dst, src, len) your_chksum_copy(dst, src, len)
donatien 0:8e01dca41002 437 */
donatien 0:8e01dca41002 438
donatien 0:8e01dca41002 439 #if (LWIP_CHKSUM_COPY_ALGORITHM == 1) /* Version #1 */
donatien 0:8e01dca41002 440 /** Safe but slow: first call MEMCPY, then call LWIP_CHKSUM.
donatien 0:8e01dca41002 441 * For architectures with big caches, data might still be in cache when
donatien 0:8e01dca41002 442 * generating the checksum after copying.
donatien 0:8e01dca41002 443 */
donatien 0:8e01dca41002 444 u16_t
donatien 0:8e01dca41002 445 lwip_chksum_copy(void *dst, const void *src, u16_t len)
donatien 0:8e01dca41002 446 {
donatien 0:8e01dca41002 447 MEMCPY(dst, src, len);
donatien 0:8e01dca41002 448 return LWIP_CHKSUM(dst, len);
donatien 0:8e01dca41002 449 }
donatien 0:8e01dca41002 450 #endif /* (LWIP_CHKSUM_COPY_ALGORITHM == 1) */