David Smart / lwip

minor derivative to reduce compiler warnings and tag read-only parameters as const.

Dependents:   EthernetInterface

Fork of lwip by mbed official

core/ipv4/inet_chksum.c@21:d78ed585db09, 2018-06-10 (annotated)

Committer:
WiredHome
Date:
Sun Jun 10 22:17:20 2018 +0000
Revision:
21:d78ed585db09
Parent:
0:51ac1d130fd4 
revise some error returns for unique < 0 numbers

Who changed what in which revision?

UserRevisionLine numberNew contents of line
mbed_official 0:51ac1d130fd4 1 /**
mbed_official 0:51ac1d130fd4 2 * @file
mbed_official 0:51ac1d130fd4 3 * Incluse internet checksum functions.
mbed_official 0:51ac1d130fd4 4 *
mbed_official 0:51ac1d130fd4 5 */
mbed_official 0:51ac1d130fd4 6
mbed_official 0:51ac1d130fd4 7 /*
mbed_official 0:51ac1d130fd4 8 * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
mbed_official 0:51ac1d130fd4 9 * All rights reserved.
mbed_official 0:51ac1d130fd4 10 *
mbed_official 0:51ac1d130fd4 11 * Redistribution and use in source and binary forms, with or without modification,
mbed_official 0:51ac1d130fd4 12 * are permitted provided that the following conditions are met:
mbed_official 0:51ac1d130fd4 13 *
mbed_official 0:51ac1d130fd4 14 * 1. Redistributions of source code must retain the above copyright notice,
mbed_official 0:51ac1d130fd4 15 * this list of conditions and the following disclaimer.
mbed_official 0:51ac1d130fd4 16 * 2. Redistributions in binary form must reproduce the above copyright notice,
mbed_official 0:51ac1d130fd4 17 * this list of conditions and the following disclaimer in the documentation
mbed_official 0:51ac1d130fd4 18 * and/or other materials provided with the distribution.
mbed_official 0:51ac1d130fd4 19 * 3. The name of the author may not be used to endorse or promote products
mbed_official 0:51ac1d130fd4 20 * derived from this software without specific prior written permission.
mbed_official 0:51ac1d130fd4 21 *
mbed_official 0:51ac1d130fd4 22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
mbed_official 0:51ac1d130fd4 23 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
mbed_official 0:51ac1d130fd4 24 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
mbed_official 0:51ac1d130fd4 25 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
mbed_official 0:51ac1d130fd4 26 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
mbed_official 0:51ac1d130fd4 27 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
mbed_official 0:51ac1d130fd4 28 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
mbed_official 0:51ac1d130fd4 29 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
mbed_official 0:51ac1d130fd4 30 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
mbed_official 0:51ac1d130fd4 31 * OF SUCH DAMAGE.
mbed_official 0:51ac1d130fd4 32 *
mbed_official 0:51ac1d130fd4 33 * This file is part of the lwIP TCP/IP stack.
mbed_official 0:51ac1d130fd4 34 *
mbed_official 0:51ac1d130fd4 35 * Author: Adam Dunkels <adam@sics.se>
mbed_official 0:51ac1d130fd4 36 *
mbed_official 0:51ac1d130fd4 37 */
mbed_official 0:51ac1d130fd4 38
mbed_official 0:51ac1d130fd4 39 #include "lwip/opt.h"
mbed_official 0:51ac1d130fd4 40
mbed_official 0:51ac1d130fd4 41 #include "lwip/inet_chksum.h"
mbed_official 0:51ac1d130fd4 42 #include "lwip/def.h"
mbed_official 0:51ac1d130fd4 43
mbed_official 0:51ac1d130fd4 44 #include <stddef.h>
mbed_official 0:51ac1d130fd4 45 #include <string.h>
mbed_official 0:51ac1d130fd4 46
mbed_official 0:51ac1d130fd4 47 /* These are some reference implementations of the checksum algorithm, with the
mbed_official 0:51ac1d130fd4 48 * aim of being simple, correct and fully portable. Checksumming is the
mbed_official 0:51ac1d130fd4 49 * first thing you would want to optimize for your platform. If you create
mbed_official 0:51ac1d130fd4 50 * your own version, link it in and in your cc.h put:
mbed_official 0:51ac1d130fd4 51 *
mbed_official 0:51ac1d130fd4 52 * #define LWIP_CHKSUM <your_checksum_routine>
mbed_official 0:51ac1d130fd4 53 *
mbed_official 0:51ac1d130fd4 54 * Or you can select from the implementations below by defining
mbed_official 0:51ac1d130fd4 55 * LWIP_CHKSUM_ALGORITHM to 1, 2 or 3.
mbed_official 0:51ac1d130fd4 56 */
mbed_official 0:51ac1d130fd4 57
mbed_official 0:51ac1d130fd4 58 #ifndef LWIP_CHKSUM
mbed_official 0:51ac1d130fd4 59 # define LWIP_CHKSUM lwip_standard_chksum
mbed_official 0:51ac1d130fd4 60 # ifndef LWIP_CHKSUM_ALGORITHM
mbed_official 0:51ac1d130fd4 61 # define LWIP_CHKSUM_ALGORITHM 2
mbed_official 0:51ac1d130fd4 62 # endif
mbed_official 0:51ac1d130fd4 63 #endif
mbed_official 0:51ac1d130fd4 64 /* If none set: */
mbed_official 0:51ac1d130fd4 65 #ifndef LWIP_CHKSUM_ALGORITHM
mbed_official 0:51ac1d130fd4 66 # define LWIP_CHKSUM_ALGORITHM 0
mbed_official 0:51ac1d130fd4 67 #endif
mbed_official 0:51ac1d130fd4 68
mbed_official 0:51ac1d130fd4 69 #if (LWIP_CHKSUM_ALGORITHM == 1) /* Version #1 */
mbed_official 0:51ac1d130fd4 70 /**
mbed_official 0:51ac1d130fd4 71 * lwip checksum
mbed_official 0:51ac1d130fd4 72 *
mbed_official 0:51ac1d130fd4 73 * @param dataptr points to start of data to be summed at any boundary
mbed_official 0:51ac1d130fd4 74 * @param len length of data to be summed
mbed_official 0:51ac1d130fd4 75 * @return host order (!) lwip checksum (non-inverted Internet sum)
mbed_official 0:51ac1d130fd4 76 *
mbed_official 0:51ac1d130fd4 77 * @note accumulator size limits summable length to 64k
mbed_official 0:51ac1d130fd4 78 * @note host endianess is irrelevant (p3 RFC1071)
mbed_official 0:51ac1d130fd4 79 */
mbed_official 0:51ac1d130fd4 80 static u16_t
mbed_official 0:51ac1d130fd4 81 lwip_standard_chksum(void *dataptr, u16_t len)
mbed_official 0:51ac1d130fd4 82 {
mbed_official 0:51ac1d130fd4 83 u32_t acc;
mbed_official 0:51ac1d130fd4 84 u16_t src;
mbed_official 0:51ac1d130fd4 85 u8_t *octetptr;
mbed_official 0:51ac1d130fd4 86
mbed_official 0:51ac1d130fd4 87 acc = 0;
mbed_official 0:51ac1d130fd4 88 /* dataptr may be at odd or even addresses */
mbed_official 0:51ac1d130fd4 89 octetptr = (u8_t*)dataptr;
mbed_official 0:51ac1d130fd4 90 while (len > 1) {
mbed_official 0:51ac1d130fd4 91 /* declare first octet as most significant
mbed_official 0:51ac1d130fd4 92 thus assume network order, ignoring host order */
mbed_official 0:51ac1d130fd4 93 src = (*octetptr) << 8;
mbed_official 0:51ac1d130fd4 94 octetptr++;
mbed_official 0:51ac1d130fd4 95 /* declare second octet as least significant */
mbed_official 0:51ac1d130fd4 96 src |= (*octetptr);
mbed_official 0:51ac1d130fd4 97 octetptr++;
mbed_official 0:51ac1d130fd4 98 acc += src;
mbed_official 0:51ac1d130fd4 99 len -= 2;
mbed_official 0:51ac1d130fd4 100 }
mbed_official 0:51ac1d130fd4 101 if (len > 0) {
mbed_official 0:51ac1d130fd4 102 /* accumulate remaining octet */
mbed_official 0:51ac1d130fd4 103 src = (*octetptr) << 8;
mbed_official 0:51ac1d130fd4 104 acc += src;
mbed_official 0:51ac1d130fd4 105 }
mbed_official 0:51ac1d130fd4 106 /* add deferred carry bits */
mbed_official 0:51ac1d130fd4 107 acc = (acc >> 16) + (acc & 0x0000ffffUL);
mbed_official 0:51ac1d130fd4 108 if ((acc & 0xffff0000UL) != 0) {
mbed_official 0:51ac1d130fd4 109 acc = (acc >> 16) + (acc & 0x0000ffffUL);
mbed_official 0:51ac1d130fd4 110 }
mbed_official 0:51ac1d130fd4 111 /* This maybe a little confusing: reorder sum using htons()
mbed_official 0:51ac1d130fd4 112 instead of ntohs() since it has a little less call overhead.
mbed_official 0:51ac1d130fd4 113 The caller must invert bits for Internet sum ! */
mbed_official 0:51ac1d130fd4 114 return htons((u16_t)acc);
mbed_official 0:51ac1d130fd4 115 }
mbed_official 0:51ac1d130fd4 116 #endif
mbed_official 0:51ac1d130fd4 117
mbed_official 0:51ac1d130fd4 118 #if (LWIP_CHKSUM_ALGORITHM == 2) /* Alternative version #2 */
mbed_official 0:51ac1d130fd4 119 /*
mbed_official 0:51ac1d130fd4 120 * Curt McDowell
mbed_official 0:51ac1d130fd4 121 * Broadcom Corp.
mbed_official 0:51ac1d130fd4 122 * csm@broadcom.com
mbed_official 0:51ac1d130fd4 123 *
mbed_official 0:51ac1d130fd4 124 * IP checksum two bytes at a time with support for
mbed_official 0:51ac1d130fd4 125 * unaligned buffer.
mbed_official 0:51ac1d130fd4 126 * Works for len up to and including 0x20000.
mbed_official 0:51ac1d130fd4 127 * by Curt McDowell, Broadcom Corp. 12/08/2005
mbed_official 0:51ac1d130fd4 128 *
mbed_official 0:51ac1d130fd4 129 * @param dataptr points to start of data to be summed at any boundary
mbed_official 0:51ac1d130fd4 130 * @param len length of data to be summed
mbed_official 0:51ac1d130fd4 131 * @return host order (!) lwip checksum (non-inverted Internet sum)
mbed_official 0:51ac1d130fd4 132 */
mbed_official 0:51ac1d130fd4 133
mbed_official 0:51ac1d130fd4 134 static u16_t
mbed_official 0:51ac1d130fd4 135 lwip_standard_chksum(void *dataptr, int len)
mbed_official 0:51ac1d130fd4 136 {
mbed_official 0:51ac1d130fd4 137 u8_t *pb = (u8_t *)dataptr;
mbed_official 0:51ac1d130fd4 138 u16_t *ps, t = 0;
mbed_official 0:51ac1d130fd4 139 u32_t sum = 0;
mbed_official 0:51ac1d130fd4 140 int odd = ((mem_ptr_t)pb & 1);
mbed_official 0:51ac1d130fd4 141
mbed_official 0:51ac1d130fd4 142 /* Get aligned to u16_t */
mbed_official 0:51ac1d130fd4 143 if (odd && len > 0) {
mbed_official 0:51ac1d130fd4 144 ((u8_t *)&t)[1] = *pb++;
mbed_official 0:51ac1d130fd4 145 len--;
mbed_official 0:51ac1d130fd4 146 }
mbed_official 0:51ac1d130fd4 147
mbed_official 0:51ac1d130fd4 148 /* Add the bulk of the data */
mbed_official 0:51ac1d130fd4 149 ps = (u16_t *)(void *)pb;
mbed_official 0:51ac1d130fd4 150 while (len > 1) {
mbed_official 0:51ac1d130fd4 151 sum += *ps++;
mbed_official 0:51ac1d130fd4 152 len -= 2;
mbed_official 0:51ac1d130fd4 153 }
mbed_official 0:51ac1d130fd4 154
mbed_official 0:51ac1d130fd4 155 /* Consume left-over byte, if any */
mbed_official 0:51ac1d130fd4 156 if (len > 0) {
mbed_official 0:51ac1d130fd4 157 ((u8_t *)&t)[0] = *(u8_t *)ps;
mbed_official 0:51ac1d130fd4 158 }
mbed_official 0:51ac1d130fd4 159
mbed_official 0:51ac1d130fd4 160 /* Add end bytes */
mbed_official 0:51ac1d130fd4 161 sum += t;
mbed_official 0:51ac1d130fd4 162
mbed_official 0:51ac1d130fd4 163 /* Fold 32-bit sum to 16 bits
mbed_official 0:51ac1d130fd4 164 calling this twice is propably faster than if statements... */
mbed_official 0:51ac1d130fd4 165 sum = FOLD_U32T(sum);
mbed_official 0:51ac1d130fd4 166 sum = FOLD_U32T(sum);
mbed_official 0:51ac1d130fd4 167
mbed_official 0:51ac1d130fd4 168 /* Swap if alignment was odd */
mbed_official 0:51ac1d130fd4 169 if (odd) {
mbed_official 0:51ac1d130fd4 170 sum = SWAP_BYTES_IN_WORD(sum);
mbed_official 0:51ac1d130fd4 171 }
mbed_official 0:51ac1d130fd4 172
mbed_official 0:51ac1d130fd4 173 return (u16_t)sum;
mbed_official 0:51ac1d130fd4 174 }
mbed_official 0:51ac1d130fd4 175 #endif
mbed_official 0:51ac1d130fd4 176
mbed_official 0:51ac1d130fd4 177 #if (LWIP_CHKSUM_ALGORITHM == 3) /* Alternative version #3 */
mbed_official 0:51ac1d130fd4 178 /**
mbed_official 0:51ac1d130fd4 179 * An optimized checksum routine. Basically, it uses loop-unrolling on
mbed_official 0:51ac1d130fd4 180 * the checksum loop, treating the head and tail bytes specially, whereas
mbed_official 0:51ac1d130fd4 181 * the inner loop acts on 8 bytes at a time.
mbed_official 0:51ac1d130fd4 182 *
mbed_official 0:51ac1d130fd4 183 * @arg start of buffer to be checksummed. May be an odd byte address.
mbed_official 0:51ac1d130fd4 184 * @len number of bytes in the buffer to be checksummed.
mbed_official 0:51ac1d130fd4 185 * @return host order (!) lwip checksum (non-inverted Internet sum)
mbed_official 0:51ac1d130fd4 186 *
mbed_official 0:51ac1d130fd4 187 * by Curt McDowell, Broadcom Corp. December 8th, 2005
mbed_official 0:51ac1d130fd4 188 */
mbed_official 0:51ac1d130fd4 189
mbed_official 0:51ac1d130fd4 190 static u16_t
mbed_official 0:51ac1d130fd4 191 lwip_standard_chksum(void *dataptr, int len)
mbed_official 0:51ac1d130fd4 192 {
mbed_official 0:51ac1d130fd4 193 u8_t *pb = (u8_t *)dataptr;
mbed_official 0:51ac1d130fd4 194 u16_t *ps, t = 0;
mbed_official 0:51ac1d130fd4 195 u32_t *pl;
mbed_official 0:51ac1d130fd4 196 u32_t sum = 0, tmp;
mbed_official 0:51ac1d130fd4 197 /* starts at odd byte address? */
mbed_official 0:51ac1d130fd4 198 int odd = ((mem_ptr_t)pb & 1);
mbed_official 0:51ac1d130fd4 199
mbed_official 0:51ac1d130fd4 200 if (odd && len > 0) {
mbed_official 0:51ac1d130fd4 201 ((u8_t *)&t)[1] = *pb++;
mbed_official 0:51ac1d130fd4 202 len--;
mbed_official 0:51ac1d130fd4 203 }
mbed_official 0:51ac1d130fd4 204
mbed_official 0:51ac1d130fd4 205 ps = (u16_t *)pb;
mbed_official 0:51ac1d130fd4 206
mbed_official 0:51ac1d130fd4 207 if (((mem_ptr_t)ps & 3) && len > 1) {
mbed_official 0:51ac1d130fd4 208 sum += *ps++;
mbed_official 0:51ac1d130fd4 209 len -= 2;
mbed_official 0:51ac1d130fd4 210 }
mbed_official 0:51ac1d130fd4 211
mbed_official 0:51ac1d130fd4 212 pl = (u32_t *)ps;
mbed_official 0:51ac1d130fd4 213
mbed_official 0:51ac1d130fd4 214 while (len > 7) {
mbed_official 0:51ac1d130fd4 215 tmp = sum + *pl++; /* ping */
mbed_official 0:51ac1d130fd4 216 if (tmp < sum) {
mbed_official 0:51ac1d130fd4 217 tmp++; /* add back carry */
mbed_official 0:51ac1d130fd4 218 }
mbed_official 0:51ac1d130fd4 219
mbed_official 0:51ac1d130fd4 220 sum = tmp + *pl++; /* pong */
mbed_official 0:51ac1d130fd4 221 if (sum < tmp) {
mbed_official 0:51ac1d130fd4 222 sum++; /* add back carry */
mbed_official 0:51ac1d130fd4 223 }
mbed_official 0:51ac1d130fd4 224
mbed_official 0:51ac1d130fd4 225 len -= 8;
mbed_official 0:51ac1d130fd4 226 }
mbed_official 0:51ac1d130fd4 227
mbed_official 0:51ac1d130fd4 228 /* make room in upper bits */
mbed_official 0:51ac1d130fd4 229 sum = FOLD_U32T(sum);
mbed_official 0:51ac1d130fd4 230
mbed_official 0:51ac1d130fd4 231 ps = (u16_t *)pl;
mbed_official 0:51ac1d130fd4 232
mbed_official 0:51ac1d130fd4 233 /* 16-bit aligned word remaining? */
mbed_official 0:51ac1d130fd4 234 while (len > 1) {
mbed_official 0:51ac1d130fd4 235 sum += *ps++;
mbed_official 0:51ac1d130fd4 236 len -= 2;
mbed_official 0:51ac1d130fd4 237 }
mbed_official 0:51ac1d130fd4 238
mbed_official 0:51ac1d130fd4 239 /* dangling tail byte remaining? */
mbed_official 0:51ac1d130fd4 240 if (len > 0) { /* include odd byte */
mbed_official 0:51ac1d130fd4 241 ((u8_t *)&t)[0] = *(u8_t *)ps;
mbed_official 0:51ac1d130fd4 242 }
mbed_official 0:51ac1d130fd4 243
mbed_official 0:51ac1d130fd4 244 sum += t; /* add end bytes */
mbed_official 0:51ac1d130fd4 245
mbed_official 0:51ac1d130fd4 246 /* Fold 32-bit sum to 16 bits
mbed_official 0:51ac1d130fd4 247 calling this twice is propably faster than if statements... */
mbed_official 0:51ac1d130fd4 248 sum = FOLD_U32T(sum);
mbed_official 0:51ac1d130fd4 249 sum = FOLD_U32T(sum);
mbed_official 0:51ac1d130fd4 250
mbed_official 0:51ac1d130fd4 251 if (odd) {
mbed_official 0:51ac1d130fd4 252 sum = SWAP_BYTES_IN_WORD(sum);
mbed_official 0:51ac1d130fd4 253 }
mbed_official 0:51ac1d130fd4 254
mbed_official 0:51ac1d130fd4 255 return (u16_t)sum;
mbed_official 0:51ac1d130fd4 256 }
mbed_official 0:51ac1d130fd4 257 #endif
mbed_official 0:51ac1d130fd4 258
mbed_official 0:51ac1d130fd4 259 /* inet_chksum_pseudo:
mbed_official 0:51ac1d130fd4 260 *
mbed_official 0:51ac1d130fd4 261 * Calculates the pseudo Internet checksum used by TCP and UDP for a pbuf chain.
mbed_official 0:51ac1d130fd4 262 * IP addresses are expected to be in network byte order.
mbed_official 0:51ac1d130fd4 263 *
mbed_official 0:51ac1d130fd4 264 * @param p chain of pbufs over that a checksum should be calculated (ip data part)
mbed_official 0:51ac1d130fd4 265 * @param src source ip address (used for checksum of pseudo header)
mbed_official 0:51ac1d130fd4 266 * @param dst destination ip address (used for checksum of pseudo header)
mbed_official 0:51ac1d130fd4 267 * @param proto ip protocol (used for checksum of pseudo header)
mbed_official 0:51ac1d130fd4 268 * @param proto_len length of the ip data part (used for checksum of pseudo header)
mbed_official 0:51ac1d130fd4 269 * @return checksum (as u16_t) to be saved directly in the protocol header
mbed_official 0:51ac1d130fd4 270 */
mbed_official 0:51ac1d130fd4 271 u16_t
mbed_official 0:51ac1d130fd4 272 inet_chksum_pseudo(struct pbuf *p,
mbed_official 0:51ac1d130fd4 273 ip_addr_t *src, ip_addr_t *dest,
mbed_official 0:51ac1d130fd4 274 u8_t proto, u16_t proto_len)
mbed_official 0:51ac1d130fd4 275 {
mbed_official 0:51ac1d130fd4 276 u32_t acc;
mbed_official 0:51ac1d130fd4 277 u32_t addr;
mbed_official 0:51ac1d130fd4 278 struct pbuf *q;
mbed_official 0:51ac1d130fd4 279 u8_t swapped;
mbed_official 0:51ac1d130fd4 280
mbed_official 0:51ac1d130fd4 281 acc = 0;
mbed_official 0:51ac1d130fd4 282 swapped = 0;
mbed_official 0:51ac1d130fd4 283 /* iterate through all pbuf in chain */
mbed_official 0:51ac1d130fd4 284 for(q = p; q != NULL; q = q->next) {
mbed_official 0:51ac1d130fd4 285 LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): checksumming pbuf %p (has next %p) \n",
mbed_official 0:51ac1d130fd4 286 (void *)q, (void *)q->next));
mbed_official 0:51ac1d130fd4 287 acc += LWIP_CHKSUM(q->payload, q->len);
mbed_official 0:51ac1d130fd4 288 /*LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): unwrapped lwip_chksum()=%"X32_F" \n", acc));*/
mbed_official 0:51ac1d130fd4 289 /* just executing this next line is probably faster that the if statement needed
mbed_official 0:51ac1d130fd4 290 to check whether we really need to execute it, and does no harm */
mbed_official 0:51ac1d130fd4 291 acc = FOLD_U32T(acc);
mbed_official 0:51ac1d130fd4 292 if (q->len % 2 != 0) {
mbed_official 0:51ac1d130fd4 293 swapped = 1 - swapped;
mbed_official 0:51ac1d130fd4 294 acc = SWAP_BYTES_IN_WORD(acc);
mbed_official 0:51ac1d130fd4 295 }
mbed_official 0:51ac1d130fd4 296 /*LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): wrapped lwip_chksum()=%"X32_F" \n", acc));*/
mbed_official 0:51ac1d130fd4 297 }
mbed_official 0:51ac1d130fd4 298
mbed_official 0:51ac1d130fd4 299 if (swapped) {
mbed_official 0:51ac1d130fd4 300 acc = SWAP_BYTES_IN_WORD(acc);
mbed_official 0:51ac1d130fd4 301 }
mbed_official 0:51ac1d130fd4 302 addr = ip4_addr_get_u32(src);
mbed_official 0:51ac1d130fd4 303 acc += (addr & 0xffffUL);
mbed_official 0:51ac1d130fd4 304 acc += ((addr >> 16) & 0xffffUL);
mbed_official 0:51ac1d130fd4 305 addr = ip4_addr_get_u32(dest);
mbed_official 0:51ac1d130fd4 306 acc += (addr & 0xffffUL);
mbed_official 0:51ac1d130fd4 307 acc += ((addr >> 16) & 0xffffUL);
mbed_official 0:51ac1d130fd4 308 acc += (u32_t)htons((u16_t)proto);
mbed_official 0:51ac1d130fd4 309 acc += (u32_t)htons(proto_len);
mbed_official 0:51ac1d130fd4 310
mbed_official 0:51ac1d130fd4 311 /* Fold 32-bit sum to 16 bits
mbed_official 0:51ac1d130fd4 312 calling this twice is propably faster than if statements... */
mbed_official 0:51ac1d130fd4 313 acc = FOLD_U32T(acc);
mbed_official 0:51ac1d130fd4 314 acc = FOLD_U32T(acc);
mbed_official 0:51ac1d130fd4 315 LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): pbuf chain lwip_chksum()=%"X32_F"\n", acc));
mbed_official 0:51ac1d130fd4 316 return (u16_t)~(acc & 0xffffUL);
mbed_official 0:51ac1d130fd4 317 }
mbed_official 0:51ac1d130fd4 318
mbed_official 0:51ac1d130fd4 319 /* inet_chksum_pseudo:
mbed_official 0:51ac1d130fd4 320 *
mbed_official 0:51ac1d130fd4 321 * Calculates the pseudo Internet checksum used by TCP and UDP for a pbuf chain.
mbed_official 0:51ac1d130fd4 322 * IP addresses are expected to be in network byte order.
mbed_official 0:51ac1d130fd4 323 *
mbed_official 0:51ac1d130fd4 324 * @param p chain of pbufs over that a checksum should be calculated (ip data part)
mbed_official 0:51ac1d130fd4 325 * @param src source ip address (used for checksum of pseudo header)
mbed_official 0:51ac1d130fd4 326 * @param dst destination ip address (used for checksum of pseudo header)
mbed_official 0:51ac1d130fd4 327 * @param proto ip protocol (used for checksum of pseudo header)
mbed_official 0:51ac1d130fd4 328 * @param proto_len length of the ip data part (used for checksum of pseudo header)
mbed_official 0:51ac1d130fd4 329 * @return checksum (as u16_t) to be saved directly in the protocol header
mbed_official 0:51ac1d130fd4 330 */
mbed_official 0:51ac1d130fd4 331 u16_t
mbed_official 0:51ac1d130fd4 332 inet_chksum_pseudo_partial(struct pbuf *p,
mbed_official 0:51ac1d130fd4 333 ip_addr_t *src, ip_addr_t *dest,
mbed_official 0:51ac1d130fd4 334 u8_t proto, u16_t proto_len, u16_t chksum_len)
mbed_official 0:51ac1d130fd4 335 {
mbed_official 0:51ac1d130fd4 336 u32_t acc;
mbed_official 0:51ac1d130fd4 337 u32_t addr;
mbed_official 0:51ac1d130fd4 338 struct pbuf *q;
mbed_official 0:51ac1d130fd4 339 u8_t swapped;
mbed_official 0:51ac1d130fd4 340 u16_t chklen;
mbed_official 0:51ac1d130fd4 341
mbed_official 0:51ac1d130fd4 342 acc = 0;
mbed_official 0:51ac1d130fd4 343 swapped = 0;
mbed_official 0:51ac1d130fd4 344 /* iterate through all pbuf in chain */
mbed_official 0:51ac1d130fd4 345 for(q = p; (q != NULL) && (chksum_len > 0); q = q->next) {
mbed_official 0:51ac1d130fd4 346 LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): checksumming pbuf %p (has next %p) \n",
mbed_official 0:51ac1d130fd4 347 (void *)q, (void *)q->next));
mbed_official 0:51ac1d130fd4 348 chklen = q->len;
mbed_official 0:51ac1d130fd4 349 if (chklen > chksum_len) {
mbed_official 0:51ac1d130fd4 350 chklen = chksum_len;
mbed_official 0:51ac1d130fd4 351 }
mbed_official 0:51ac1d130fd4 352 acc += LWIP_CHKSUM(q->payload, chklen);
mbed_official 0:51ac1d130fd4 353 chksum_len -= chklen;
mbed_official 0:51ac1d130fd4 354 LWIP_ASSERT("delete me", chksum_len < 0x7fff);
mbed_official 0:51ac1d130fd4 355 /*LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): unwrapped lwip_chksum()=%"X32_F" \n", acc));*/
mbed_official 0:51ac1d130fd4 356 /* fold the upper bit down */
mbed_official 0:51ac1d130fd4 357 acc = FOLD_U32T(acc);
mbed_official 0:51ac1d130fd4 358 if (q->len % 2 != 0) {
mbed_official 0:51ac1d130fd4 359 swapped = 1 - swapped;
mbed_official 0:51ac1d130fd4 360 acc = SWAP_BYTES_IN_WORD(acc);
mbed_official 0:51ac1d130fd4 361 }
mbed_official 0:51ac1d130fd4 362 /*LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): wrapped lwip_chksum()=%"X32_F" \n", acc));*/
mbed_official 0:51ac1d130fd4 363 }
mbed_official 0:51ac1d130fd4 364
mbed_official 0:51ac1d130fd4 365 if (swapped) {
mbed_official 0:51ac1d130fd4 366 acc = SWAP_BYTES_IN_WORD(acc);
mbed_official 0:51ac1d130fd4 367 }
mbed_official 0:51ac1d130fd4 368 addr = ip4_addr_get_u32(src);
mbed_official 0:51ac1d130fd4 369 acc += (addr & 0xffffUL);
mbed_official 0:51ac1d130fd4 370 acc += ((addr >> 16) & 0xffffUL);
mbed_official 0:51ac1d130fd4 371 addr = ip4_addr_get_u32(dest);
mbed_official 0:51ac1d130fd4 372 acc += (addr & 0xffffUL);
mbed_official 0:51ac1d130fd4 373 acc += ((addr >> 16) & 0xffffUL);
mbed_official 0:51ac1d130fd4 374 acc += (u32_t)htons((u16_t)proto);
mbed_official 0:51ac1d130fd4 375 acc += (u32_t)htons(proto_len);
mbed_official 0:51ac1d130fd4 376
mbed_official 0:51ac1d130fd4 377 /* Fold 32-bit sum to 16 bits
mbed_official 0:51ac1d130fd4 378 calling this twice is propably faster than if statements... */
mbed_official 0:51ac1d130fd4 379 acc = FOLD_U32T(acc);
mbed_official 0:51ac1d130fd4 380 acc = FOLD_U32T(acc);
mbed_official 0:51ac1d130fd4 381 LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): pbuf chain lwip_chksum()=%"X32_F"\n", acc));
mbed_official 0:51ac1d130fd4 382 return (u16_t)~(acc & 0xffffUL);
mbed_official 0:51ac1d130fd4 383 }
mbed_official 0:51ac1d130fd4 384
mbed_official 0:51ac1d130fd4 385 /* inet_chksum:
mbed_official 0:51ac1d130fd4 386 *
mbed_official 0:51ac1d130fd4 387 * Calculates the Internet checksum over a portion of memory. Used primarily for IP
mbed_official 0:51ac1d130fd4 388 * and ICMP.
mbed_official 0:51ac1d130fd4 389 *
mbed_official 0:51ac1d130fd4 390 * @param dataptr start of the buffer to calculate the checksum (no alignment needed)
mbed_official 0:51ac1d130fd4 391 * @param len length of the buffer to calculate the checksum
mbed_official 0:51ac1d130fd4 392 * @return checksum (as u16_t) to be saved directly in the protocol header
mbed_official 0:51ac1d130fd4 393 */
mbed_official 0:51ac1d130fd4 394
mbed_official 0:51ac1d130fd4 395 u16_t
mbed_official 0:51ac1d130fd4 396 inet_chksum(void *dataptr, u16_t len)
mbed_official 0:51ac1d130fd4 397 {
mbed_official 0:51ac1d130fd4 398 return ~LWIP_CHKSUM(dataptr, len);
mbed_official 0:51ac1d130fd4 399 }
mbed_official 0:51ac1d130fd4 400
mbed_official 0:51ac1d130fd4 401 /**
mbed_official 0:51ac1d130fd4 402 * Calculate a checksum over a chain of pbufs (without pseudo-header, much like
mbed_official 0:51ac1d130fd4 403 * inet_chksum only pbufs are used).
mbed_official 0:51ac1d130fd4 404 *
mbed_official 0:51ac1d130fd4 405 * @param p pbuf chain over that the checksum should be calculated
mbed_official 0:51ac1d130fd4 406 * @return checksum (as u16_t) to be saved directly in the protocol header
mbed_official 0:51ac1d130fd4 407 */
mbed_official 0:51ac1d130fd4 408 u16_t
mbed_official 0:51ac1d130fd4 409 inet_chksum_pbuf(struct pbuf *p)
mbed_official 0:51ac1d130fd4 410 {
mbed_official 0:51ac1d130fd4 411 u32_t acc;
mbed_official 0:51ac1d130fd4 412 struct pbuf *q;
mbed_official 0:51ac1d130fd4 413 u8_t swapped;
mbed_official 0:51ac1d130fd4 414
mbed_official 0:51ac1d130fd4 415 acc = 0;
mbed_official 0:51ac1d130fd4 416 swapped = 0;
mbed_official 0:51ac1d130fd4 417 for(q = p; q != NULL; q = q->next) {
mbed_official 0:51ac1d130fd4 418 acc += LWIP_CHKSUM(q->payload, q->len);
mbed_official 0:51ac1d130fd4 419 acc = FOLD_U32T(acc);
mbed_official 0:51ac1d130fd4 420 if (q->len % 2 != 0) {
mbed_official 0:51ac1d130fd4 421 swapped = 1 - swapped;
mbed_official 0:51ac1d130fd4 422 acc = SWAP_BYTES_IN_WORD(acc);
mbed_official 0:51ac1d130fd4 423 }
mbed_official 0:51ac1d130fd4 424 }
mbed_official 0:51ac1d130fd4 425
mbed_official 0:51ac1d130fd4 426 if (swapped) {
mbed_official 0:51ac1d130fd4 427 acc = SWAP_BYTES_IN_WORD(acc);
mbed_official 0:51ac1d130fd4 428 }
mbed_official 0:51ac1d130fd4 429 return (u16_t)~(acc & 0xffffUL);
mbed_official 0:51ac1d130fd4 430 }
mbed_official 0:51ac1d130fd4 431
mbed_official 0:51ac1d130fd4 432 /* These are some implementations for LWIP_CHKSUM_COPY, which copies data
mbed_official 0:51ac1d130fd4 433 * like MEMCPY but generates a checksum at the same time. Since this is a
mbed_official 0:51ac1d130fd4 434 * performance-sensitive function, you might want to create your own version
mbed_official 0:51ac1d130fd4 435 * in assembly targeted at your hardware by defining it in lwipopts.h:
mbed_official 0:51ac1d130fd4 436 * #define LWIP_CHKSUM_COPY(dst, src, len) your_chksum_copy(dst, src, len)
mbed_official 0:51ac1d130fd4 437 */
mbed_official 0:51ac1d130fd4 438
mbed_official 0:51ac1d130fd4 439 #if (LWIP_CHKSUM_COPY_ALGORITHM == 1) /* Version #1 */
mbed_official 0:51ac1d130fd4 440 /** Safe but slow: first call MEMCPY, then call LWIP_CHKSUM.
mbed_official 0:51ac1d130fd4 441 * For architectures with big caches, data might still be in cache when
mbed_official 0:51ac1d130fd4 442 * generating the checksum after copying.
mbed_official 0:51ac1d130fd4 443 */
mbed_official 0:51ac1d130fd4 444 u16_t
mbed_official 0:51ac1d130fd4 445 lwip_chksum_copy(void *dst, const void *src, u16_t len)
mbed_official 0:51ac1d130fd4 446 {
mbed_official 0:51ac1d130fd4 447 MEMCPY(dst, src, len);
mbed_official 0:51ac1d130fd4 448 return LWIP_CHKSUM(dst, len);
mbed_official 0:51ac1d130fd4 449 }
mbed_official 0:51ac1d130fd4 450 #endif /* (LWIP_CHKSUM_COPY_ALGORITHM == 1) */