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NetServices/lwip/core/ipv4/inet_chksum.c@0:05ccbd4f84f1, 2013-12-02 (annotated)

Committer:
hendrikvincent
Date:
Mon Dec 02 09:01:23 2013 +0000
Revision:
0:05ccbd4f84f1
eerste programma;

Who changed what in which revision?

UserRevisionLine numberNew contents of line
hendrikvincent 0:05ccbd4f84f1 1 /**
hendrikvincent 0:05ccbd4f84f1 2 * @file
hendrikvincent 0:05ccbd4f84f1 3 * Incluse internet checksum functions.
hendrikvincent 0:05ccbd4f84f1 4 *
hendrikvincent 0:05ccbd4f84f1 5 */
hendrikvincent 0:05ccbd4f84f1 6
hendrikvincent 0:05ccbd4f84f1 7 /*
hendrikvincent 0:05ccbd4f84f1 8 * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
hendrikvincent 0:05ccbd4f84f1 9 * All rights reserved.
hendrikvincent 0:05ccbd4f84f1 10 *
hendrikvincent 0:05ccbd4f84f1 11 * Redistribution and use in source and binary forms, with or without modification,
hendrikvincent 0:05ccbd4f84f1 12 * are permitted provided that the following conditions are met:
hendrikvincent 0:05ccbd4f84f1 13 *
hendrikvincent 0:05ccbd4f84f1 14 * 1. Redistributions of source code must retain the above copyright notice,
hendrikvincent 0:05ccbd4f84f1 15 * this list of conditions and the following disclaimer.
hendrikvincent 0:05ccbd4f84f1 16 * 2. Redistributions in binary form must reproduce the above copyright notice,
hendrikvincent 0:05ccbd4f84f1 17 * this list of conditions and the following disclaimer in the documentation
hendrikvincent 0:05ccbd4f84f1 18 * and/or other materials provided with the distribution.
hendrikvincent 0:05ccbd4f84f1 19 * 3. The name of the author may not be used to endorse or promote products
hendrikvincent 0:05ccbd4f84f1 20 * derived from this software without specific prior written permission.
hendrikvincent 0:05ccbd4f84f1 21 *
hendrikvincent 0:05ccbd4f84f1 22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
hendrikvincent 0:05ccbd4f84f1 23 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
hendrikvincent 0:05ccbd4f84f1 24 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
hendrikvincent 0:05ccbd4f84f1 25 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
hendrikvincent 0:05ccbd4f84f1 26 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
hendrikvincent 0:05ccbd4f84f1 27 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
hendrikvincent 0:05ccbd4f84f1 28 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
hendrikvincent 0:05ccbd4f84f1 29 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
hendrikvincent 0:05ccbd4f84f1 30 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
hendrikvincent 0:05ccbd4f84f1 31 * OF SUCH DAMAGE.
hendrikvincent 0:05ccbd4f84f1 32 *
hendrikvincent 0:05ccbd4f84f1 33 * This file is part of the lwIP TCP/IP stack.
hendrikvincent 0:05ccbd4f84f1 34 *
hendrikvincent 0:05ccbd4f84f1 35 * Author: Adam Dunkels <adam@sics.se>
hendrikvincent 0:05ccbd4f84f1 36 *
hendrikvincent 0:05ccbd4f84f1 37 */
hendrikvincent 0:05ccbd4f84f1 38
hendrikvincent 0:05ccbd4f84f1 39 #include "lwip/opt.h"
hendrikvincent 0:05ccbd4f84f1 40
hendrikvincent 0:05ccbd4f84f1 41 #include "lwip/inet_chksum.h"
hendrikvincent 0:05ccbd4f84f1 42 #include "lwip/def.h"
hendrikvincent 0:05ccbd4f84f1 43
hendrikvincent 0:05ccbd4f84f1 44 #include <stddef.h>
hendrikvincent 0:05ccbd4f84f1 45 #include <string.h>
hendrikvincent 0:05ccbd4f84f1 46
hendrikvincent 0:05ccbd4f84f1 47 /* These are some reference implementations of the checksum algorithm, with the
hendrikvincent 0:05ccbd4f84f1 48 * aim of being simple, correct and fully portable. Checksumming is the
hendrikvincent 0:05ccbd4f84f1 49 * first thing you would want to optimize for your platform. If you create
hendrikvincent 0:05ccbd4f84f1 50 * your own version, link it in and in your cc.h put:
hendrikvincent 0:05ccbd4f84f1 51 *
hendrikvincent 0:05ccbd4f84f1 52 * #define LWIP_CHKSUM <your_checksum_routine>
hendrikvincent 0:05ccbd4f84f1 53 *
hendrikvincent 0:05ccbd4f84f1 54 * Or you can select from the implementations below by defining
hendrikvincent 0:05ccbd4f84f1 55 * LWIP_CHKSUM_ALGORITHM to 1, 2 or 3.
hendrikvincent 0:05ccbd4f84f1 56 */
hendrikvincent 0:05ccbd4f84f1 57
hendrikvincent 0:05ccbd4f84f1 58 #ifndef LWIP_CHKSUM
hendrikvincent 0:05ccbd4f84f1 59 # define LWIP_CHKSUM lwip_standard_chksum
hendrikvincent 0:05ccbd4f84f1 60 # ifndef LWIP_CHKSUM_ALGORITHM
hendrikvincent 0:05ccbd4f84f1 61 # define LWIP_CHKSUM_ALGORITHM 2
hendrikvincent 0:05ccbd4f84f1 62 # endif
hendrikvincent 0:05ccbd4f84f1 63 #endif
hendrikvincent 0:05ccbd4f84f1 64 /* If none set: */
hendrikvincent 0:05ccbd4f84f1 65 #ifndef LWIP_CHKSUM_ALGORITHM
hendrikvincent 0:05ccbd4f84f1 66 # define LWIP_CHKSUM_ALGORITHM 0
hendrikvincent 0:05ccbd4f84f1 67 #endif
hendrikvincent 0:05ccbd4f84f1 68
hendrikvincent 0:05ccbd4f84f1 69 #if (LWIP_CHKSUM_ALGORITHM == 1) /* Version #1 */
hendrikvincent 0:05ccbd4f84f1 70 /**
hendrikvincent 0:05ccbd4f84f1 71 * lwip checksum
hendrikvincent 0:05ccbd4f84f1 72 *
hendrikvincent 0:05ccbd4f84f1 73 * @param dataptr points to start of data to be summed at any boundary
hendrikvincent 0:05ccbd4f84f1 74 * @param len length of data to be summed
hendrikvincent 0:05ccbd4f84f1 75 * @return host order (!) lwip checksum (non-inverted Internet sum)
hendrikvincent 0:05ccbd4f84f1 76 *
hendrikvincent 0:05ccbd4f84f1 77 * @note accumulator size limits summable length to 64k
hendrikvincent 0:05ccbd4f84f1 78 * @note host endianess is irrelevant (p3 RFC1071)
hendrikvincent 0:05ccbd4f84f1 79 */
hendrikvincent 0:05ccbd4f84f1 80 static u16_t
hendrikvincent 0:05ccbd4f84f1 81 lwip_standard_chksum(void *dataptr, u16_t len)
hendrikvincent 0:05ccbd4f84f1 82 {
hendrikvincent 0:05ccbd4f84f1 83 u32_t acc;
hendrikvincent 0:05ccbd4f84f1 84 u16_t src;
hendrikvincent 0:05ccbd4f84f1 85 u8_t *octetptr;
hendrikvincent 0:05ccbd4f84f1 86
hendrikvincent 0:05ccbd4f84f1 87 acc = 0;
hendrikvincent 0:05ccbd4f84f1 88 /* dataptr may be at odd or even addresses */
hendrikvincent 0:05ccbd4f84f1 89 octetptr = (u8_t*)dataptr;
hendrikvincent 0:05ccbd4f84f1 90 while (len > 1) {
hendrikvincent 0:05ccbd4f84f1 91 /* declare first octet as most significant
hendrikvincent 0:05ccbd4f84f1 92 thus assume network order, ignoring host order */
hendrikvincent 0:05ccbd4f84f1 93 src = (*octetptr) << 8;
hendrikvincent 0:05ccbd4f84f1 94 octetptr++;
hendrikvincent 0:05ccbd4f84f1 95 /* declare second octet as least significant */
hendrikvincent 0:05ccbd4f84f1 96 src |= (*octetptr);
hendrikvincent 0:05ccbd4f84f1 97 octetptr++;
hendrikvincent 0:05ccbd4f84f1 98 acc += src;
hendrikvincent 0:05ccbd4f84f1 99 len -= 2;
hendrikvincent 0:05ccbd4f84f1 100 }
hendrikvincent 0:05ccbd4f84f1 101 if (len > 0) {
hendrikvincent 0:05ccbd4f84f1 102 /* accumulate remaining octet */
hendrikvincent 0:05ccbd4f84f1 103 src = (*octetptr) << 8;
hendrikvincent 0:05ccbd4f84f1 104 acc += src;
hendrikvincent 0:05ccbd4f84f1 105 }
hendrikvincent 0:05ccbd4f84f1 106 /* add deferred carry bits */
hendrikvincent 0:05ccbd4f84f1 107 acc = (acc >> 16) + (acc & 0x0000ffffUL);
hendrikvincent 0:05ccbd4f84f1 108 if ((acc & 0xffff0000UL) != 0) {
hendrikvincent 0:05ccbd4f84f1 109 acc = (acc >> 16) + (acc & 0x0000ffffUL);
hendrikvincent 0:05ccbd4f84f1 110 }
hendrikvincent 0:05ccbd4f84f1 111 /* This maybe a little confusing: reorder sum using htons()
hendrikvincent 0:05ccbd4f84f1 112 instead of ntohs() since it has a little less call overhead.
hendrikvincent 0:05ccbd4f84f1 113 The caller must invert bits for Internet sum ! */
hendrikvincent 0:05ccbd4f84f1 114 return htons((u16_t)acc);
hendrikvincent 0:05ccbd4f84f1 115 }
hendrikvincent 0:05ccbd4f84f1 116 #endif
hendrikvincent 0:05ccbd4f84f1 117
hendrikvincent 0:05ccbd4f84f1 118 #if (LWIP_CHKSUM_ALGORITHM == 2) /* Alternative version #2 */
hendrikvincent 0:05ccbd4f84f1 119 /*
hendrikvincent 0:05ccbd4f84f1 120 * Curt McDowell
hendrikvincent 0:05ccbd4f84f1 121 * Broadcom Corp.
hendrikvincent 0:05ccbd4f84f1 122 * csm@broadcom.com
hendrikvincent 0:05ccbd4f84f1 123 *
hendrikvincent 0:05ccbd4f84f1 124 * IP checksum two bytes at a time with support for
hendrikvincent 0:05ccbd4f84f1 125 * unaligned buffer.
hendrikvincent 0:05ccbd4f84f1 126 * Works for len up to and including 0x20000.
hendrikvincent 0:05ccbd4f84f1 127 * by Curt McDowell, Broadcom Corp. 12/08/2005
hendrikvincent 0:05ccbd4f84f1 128 *
hendrikvincent 0:05ccbd4f84f1 129 * @param dataptr points to start of data to be summed at any boundary
hendrikvincent 0:05ccbd4f84f1 130 * @param len length of data to be summed
hendrikvincent 0:05ccbd4f84f1 131 * @return host order (!) lwip checksum (non-inverted Internet sum)
hendrikvincent 0:05ccbd4f84f1 132 */
hendrikvincent 0:05ccbd4f84f1 133
hendrikvincent 0:05ccbd4f84f1 134 static u16_t
hendrikvincent 0:05ccbd4f84f1 135 lwip_standard_chksum(void *dataptr, int len)
hendrikvincent 0:05ccbd4f84f1 136 {
hendrikvincent 0:05ccbd4f84f1 137 u8_t *pb = (u8_t *)dataptr;
hendrikvincent 0:05ccbd4f84f1 138 u16_t *ps, t = 0;
hendrikvincent 0:05ccbd4f84f1 139 u32_t sum = 0;
hendrikvincent 0:05ccbd4f84f1 140 int odd = ((mem_ptr_t)pb & 1);
hendrikvincent 0:05ccbd4f84f1 141
hendrikvincent 0:05ccbd4f84f1 142 /* Get aligned to u16_t */
hendrikvincent 0:05ccbd4f84f1 143 if (odd && len > 0) {
hendrikvincent 0:05ccbd4f84f1 144 ((u8_t *)&t)[1] = *pb++;
hendrikvincent 0:05ccbd4f84f1 145 len--;
hendrikvincent 0:05ccbd4f84f1 146 }
hendrikvincent 0:05ccbd4f84f1 147
hendrikvincent 0:05ccbd4f84f1 148 /* Add the bulk of the data */
hendrikvincent 0:05ccbd4f84f1 149 ps = (u16_t *)(void *)pb;
hendrikvincent 0:05ccbd4f84f1 150 while (len > 1) {
hendrikvincent 0:05ccbd4f84f1 151 sum += *ps++;
hendrikvincent 0:05ccbd4f84f1 152 len -= 2;
hendrikvincent 0:05ccbd4f84f1 153 }
hendrikvincent 0:05ccbd4f84f1 154
hendrikvincent 0:05ccbd4f84f1 155 /* Consume left-over byte, if any */
hendrikvincent 0:05ccbd4f84f1 156 if (len > 0) {
hendrikvincent 0:05ccbd4f84f1 157 ((u8_t *)&t)[0] = *(u8_t *)ps;
hendrikvincent 0:05ccbd4f84f1 158 }
hendrikvincent 0:05ccbd4f84f1 159
hendrikvincent 0:05ccbd4f84f1 160 /* Add end bytes */
hendrikvincent 0:05ccbd4f84f1 161 sum += t;
hendrikvincent 0:05ccbd4f84f1 162
hendrikvincent 0:05ccbd4f84f1 163 /* Fold 32-bit sum to 16 bits
hendrikvincent 0:05ccbd4f84f1 164 calling this twice is propably faster than if statements... */
hendrikvincent 0:05ccbd4f84f1 165 sum = FOLD_U32T(sum);
hendrikvincent 0:05ccbd4f84f1 166 sum = FOLD_U32T(sum);
hendrikvincent 0:05ccbd4f84f1 167
hendrikvincent 0:05ccbd4f84f1 168 /* Swap if alignment was odd */
hendrikvincent 0:05ccbd4f84f1 169 if (odd) {
hendrikvincent 0:05ccbd4f84f1 170 sum = SWAP_BYTES_IN_WORD(sum);
hendrikvincent 0:05ccbd4f84f1 171 }
hendrikvincent 0:05ccbd4f84f1 172
hendrikvincent 0:05ccbd4f84f1 173 return (u16_t)sum;
hendrikvincent 0:05ccbd4f84f1 174 }
hendrikvincent 0:05ccbd4f84f1 175 #endif
hendrikvincent 0:05ccbd4f84f1 176
hendrikvincent 0:05ccbd4f84f1 177 #if (LWIP_CHKSUM_ALGORITHM == 3) /* Alternative version #3 */
hendrikvincent 0:05ccbd4f84f1 178 /**
hendrikvincent 0:05ccbd4f84f1 179 * An optimized checksum routine. Basically, it uses loop-unrolling on
hendrikvincent 0:05ccbd4f84f1 180 * the checksum loop, treating the head and tail bytes specially, whereas
hendrikvincent 0:05ccbd4f84f1 181 * the inner loop acts on 8 bytes at a time.
hendrikvincent 0:05ccbd4f84f1 182 *
hendrikvincent 0:05ccbd4f84f1 183 * @arg start of buffer to be checksummed. May be an odd byte address.
hendrikvincent 0:05ccbd4f84f1 184 * @len number of bytes in the buffer to be checksummed.
hendrikvincent 0:05ccbd4f84f1 185 * @return host order (!) lwip checksum (non-inverted Internet sum)
hendrikvincent 0:05ccbd4f84f1 186 *
hendrikvincent 0:05ccbd4f84f1 187 * by Curt McDowell, Broadcom Corp. December 8th, 2005
hendrikvincent 0:05ccbd4f84f1 188 */
hendrikvincent 0:05ccbd4f84f1 189
hendrikvincent 0:05ccbd4f84f1 190 static u16_t
hendrikvincent 0:05ccbd4f84f1 191 lwip_standard_chksum(void *dataptr, int len)
hendrikvincent 0:05ccbd4f84f1 192 {
hendrikvincent 0:05ccbd4f84f1 193 u8_t *pb = (u8_t *)dataptr;
hendrikvincent 0:05ccbd4f84f1 194 u16_t *ps, t = 0;
hendrikvincent 0:05ccbd4f84f1 195 u32_t *pl;
hendrikvincent 0:05ccbd4f84f1 196 u32_t sum = 0, tmp;
hendrikvincent 0:05ccbd4f84f1 197 /* starts at odd byte address? */
hendrikvincent 0:05ccbd4f84f1 198 int odd = ((mem_ptr_t)pb & 1);
hendrikvincent 0:05ccbd4f84f1 199
hendrikvincent 0:05ccbd4f84f1 200 if (odd && len > 0) {
hendrikvincent 0:05ccbd4f84f1 201 ((u8_t *)&t)[1] = *pb++;
hendrikvincent 0:05ccbd4f84f1 202 len--;
hendrikvincent 0:05ccbd4f84f1 203 }
hendrikvincent 0:05ccbd4f84f1 204
hendrikvincent 0:05ccbd4f84f1 205 ps = (u16_t *)pb;
hendrikvincent 0:05ccbd4f84f1 206
hendrikvincent 0:05ccbd4f84f1 207 if (((mem_ptr_t)ps & 3) && len > 1) {
hendrikvincent 0:05ccbd4f84f1 208 sum += *ps++;
hendrikvincent 0:05ccbd4f84f1 209 len -= 2;
hendrikvincent 0:05ccbd4f84f1 210 }
hendrikvincent 0:05ccbd4f84f1 211
hendrikvincent 0:05ccbd4f84f1 212 pl = (u32_t *)ps;
hendrikvincent 0:05ccbd4f84f1 213
hendrikvincent 0:05ccbd4f84f1 214 while (len > 7) {
hendrikvincent 0:05ccbd4f84f1 215 tmp = sum + *pl++; /* ping */
hendrikvincent 0:05ccbd4f84f1 216 if (tmp < sum) {
hendrikvincent 0:05ccbd4f84f1 217 tmp++; /* add back carry */
hendrikvincent 0:05ccbd4f84f1 218 }
hendrikvincent 0:05ccbd4f84f1 219
hendrikvincent 0:05ccbd4f84f1 220 sum = tmp + *pl++; /* pong */
hendrikvincent 0:05ccbd4f84f1 221 if (sum < tmp) {
hendrikvincent 0:05ccbd4f84f1 222 sum++; /* add back carry */
hendrikvincent 0:05ccbd4f84f1 223 }
hendrikvincent 0:05ccbd4f84f1 224
hendrikvincent 0:05ccbd4f84f1 225 len -= 8;
hendrikvincent 0:05ccbd4f84f1 226 }
hendrikvincent 0:05ccbd4f84f1 227
hendrikvincent 0:05ccbd4f84f1 228 /* make room in upper bits */
hendrikvincent 0:05ccbd4f84f1 229 sum = FOLD_U32T(sum);
hendrikvincent 0:05ccbd4f84f1 230
hendrikvincent 0:05ccbd4f84f1 231 ps = (u16_t *)pl;
hendrikvincent 0:05ccbd4f84f1 232
hendrikvincent 0:05ccbd4f84f1 233 /* 16-bit aligned word remaining? */
hendrikvincent 0:05ccbd4f84f1 234 while (len > 1) {
hendrikvincent 0:05ccbd4f84f1 235 sum += *ps++;
hendrikvincent 0:05ccbd4f84f1 236 len -= 2;
hendrikvincent 0:05ccbd4f84f1 237 }
hendrikvincent 0:05ccbd4f84f1 238
hendrikvincent 0:05ccbd4f84f1 239 /* dangling tail byte remaining? */
hendrikvincent 0:05ccbd4f84f1 240 if (len > 0) { /* include odd byte */
hendrikvincent 0:05ccbd4f84f1 241 ((u8_t *)&t)[0] = *(u8_t *)ps;
hendrikvincent 0:05ccbd4f84f1 242 }
hendrikvincent 0:05ccbd4f84f1 243
hendrikvincent 0:05ccbd4f84f1 244 sum += t; /* add end bytes */
hendrikvincent 0:05ccbd4f84f1 245
hendrikvincent 0:05ccbd4f84f1 246 /* Fold 32-bit sum to 16 bits
hendrikvincent 0:05ccbd4f84f1 247 calling this twice is propably faster than if statements... */
hendrikvincent 0:05ccbd4f84f1 248 sum = FOLD_U32T(sum);
hendrikvincent 0:05ccbd4f84f1 249 sum = FOLD_U32T(sum);
hendrikvincent 0:05ccbd4f84f1 250
hendrikvincent 0:05ccbd4f84f1 251 if (odd) {
hendrikvincent 0:05ccbd4f84f1 252 sum = SWAP_BYTES_IN_WORD(sum);
hendrikvincent 0:05ccbd4f84f1 253 }
hendrikvincent 0:05ccbd4f84f1 254
hendrikvincent 0:05ccbd4f84f1 255 return (u16_t)sum;
hendrikvincent 0:05ccbd4f84f1 256 }
hendrikvincent 0:05ccbd4f84f1 257 #endif
hendrikvincent 0:05ccbd4f84f1 258
hendrikvincent 0:05ccbd4f84f1 259 /* inet_chksum_pseudo:
hendrikvincent 0:05ccbd4f84f1 260 *
hendrikvincent 0:05ccbd4f84f1 261 * Calculates the pseudo Internet checksum used by TCP and UDP for a pbuf chain.
hendrikvincent 0:05ccbd4f84f1 262 * IP addresses are expected to be in network byte order.
hendrikvincent 0:05ccbd4f84f1 263 *
hendrikvincent 0:05ccbd4f84f1 264 * @param p chain of pbufs over that a checksum should be calculated (ip data part)
hendrikvincent 0:05ccbd4f84f1 265 * @param src source ip address (used for checksum of pseudo header)
hendrikvincent 0:05ccbd4f84f1 266 * @param dst destination ip address (used for checksum of pseudo header)
hendrikvincent 0:05ccbd4f84f1 267 * @param proto ip protocol (used for checksum of pseudo header)
hendrikvincent 0:05ccbd4f84f1 268 * @param proto_len length of the ip data part (used for checksum of pseudo header)
hendrikvincent 0:05ccbd4f84f1 269 * @return checksum (as u16_t) to be saved directly in the protocol header
hendrikvincent 0:05ccbd4f84f1 270 */
hendrikvincent 0:05ccbd4f84f1 271 u16_t
hendrikvincent 0:05ccbd4f84f1 272 inet_chksum_pseudo(struct pbuf *p,
hendrikvincent 0:05ccbd4f84f1 273 ip_addr_t *src, ip_addr_t *dest,
hendrikvincent 0:05ccbd4f84f1 274 u8_t proto, u16_t proto_len)
hendrikvincent 0:05ccbd4f84f1 275 {
hendrikvincent 0:05ccbd4f84f1 276 u32_t acc;
hendrikvincent 0:05ccbd4f84f1 277 u32_t addr;
hendrikvincent 0:05ccbd4f84f1 278 struct pbuf *q;
hendrikvincent 0:05ccbd4f84f1 279 u8_t swapped;
hendrikvincent 0:05ccbd4f84f1 280
hendrikvincent 0:05ccbd4f84f1 281 acc = 0;
hendrikvincent 0:05ccbd4f84f1 282 swapped = 0;
hendrikvincent 0:05ccbd4f84f1 283 /* iterate through all pbuf in chain */
hendrikvincent 0:05ccbd4f84f1 284 for(q = p; q != NULL; q = q->next) {
hendrikvincent 0:05ccbd4f84f1 285 LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): checksumming pbuf %p (has next %p) \n",
hendrikvincent 0:05ccbd4f84f1 286 (void *)q, (void *)q->next));
hendrikvincent 0:05ccbd4f84f1 287 acc += LWIP_CHKSUM(q->payload, q->len);
hendrikvincent 0:05ccbd4f84f1 288 /*LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): unwrapped lwip_chksum()=%"X32_F" \n", acc));*/
hendrikvincent 0:05ccbd4f84f1 289 /* just executing this next line is probably faster that the if statement needed
hendrikvincent 0:05ccbd4f84f1 290 to check whether we really need to execute it, and does no harm */
hendrikvincent 0:05ccbd4f84f1 291 acc = FOLD_U32T(acc);
hendrikvincent 0:05ccbd4f84f1 292 if (q->len % 2 != 0) {
hendrikvincent 0:05ccbd4f84f1 293 swapped = 1 - swapped;
hendrikvincent 0:05ccbd4f84f1 294 acc = SWAP_BYTES_IN_WORD(acc);
hendrikvincent 0:05ccbd4f84f1 295 }
hendrikvincent 0:05ccbd4f84f1 296 /*LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): wrapped lwip_chksum()=%"X32_F" \n", acc));*/
hendrikvincent 0:05ccbd4f84f1 297 }
hendrikvincent 0:05ccbd4f84f1 298
hendrikvincent 0:05ccbd4f84f1 299 if (swapped) {
hendrikvincent 0:05ccbd4f84f1 300 acc = SWAP_BYTES_IN_WORD(acc);
hendrikvincent 0:05ccbd4f84f1 301 }
hendrikvincent 0:05ccbd4f84f1 302 addr = ip4_addr_get_u32(src);
hendrikvincent 0:05ccbd4f84f1 303 acc += (addr & 0xffffUL);
hendrikvincent 0:05ccbd4f84f1 304 acc += ((addr >> 16) & 0xffffUL);
hendrikvincent 0:05ccbd4f84f1 305 addr = ip4_addr_get_u32(dest);
hendrikvincent 0:05ccbd4f84f1 306 acc += (addr & 0xffffUL);
hendrikvincent 0:05ccbd4f84f1 307 acc += ((addr >> 16) & 0xffffUL);
hendrikvincent 0:05ccbd4f84f1 308 acc += (u32_t)htons((u16_t)proto);
hendrikvincent 0:05ccbd4f84f1 309 acc += (u32_t)htons(proto_len);
hendrikvincent 0:05ccbd4f84f1 310
hendrikvincent 0:05ccbd4f84f1 311 /* Fold 32-bit sum to 16 bits
hendrikvincent 0:05ccbd4f84f1 312 calling this twice is propably faster than if statements... */
hendrikvincent 0:05ccbd4f84f1 313 acc = FOLD_U32T(acc);
hendrikvincent 0:05ccbd4f84f1 314 acc = FOLD_U32T(acc);
hendrikvincent 0:05ccbd4f84f1 315 LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): pbuf chain lwip_chksum()=%"X32_F"\n", acc));
hendrikvincent 0:05ccbd4f84f1 316 return (u16_t)~(acc & 0xffffUL);
hendrikvincent 0:05ccbd4f84f1 317 }
hendrikvincent 0:05ccbd4f84f1 318
hendrikvincent 0:05ccbd4f84f1 319 /* inet_chksum_pseudo:
hendrikvincent 0:05ccbd4f84f1 320 *
hendrikvincent 0:05ccbd4f84f1 321 * Calculates the pseudo Internet checksum used by TCP and UDP for a pbuf chain.
hendrikvincent 0:05ccbd4f84f1 322 * IP addresses are expected to be in network byte order.
hendrikvincent 0:05ccbd4f84f1 323 *
hendrikvincent 0:05ccbd4f84f1 324 * @param p chain of pbufs over that a checksum should be calculated (ip data part)
hendrikvincent 0:05ccbd4f84f1 325 * @param src source ip address (used for checksum of pseudo header)
hendrikvincent 0:05ccbd4f84f1 326 * @param dst destination ip address (used for checksum of pseudo header)
hendrikvincent 0:05ccbd4f84f1 327 * @param proto ip protocol (used for checksum of pseudo header)
hendrikvincent 0:05ccbd4f84f1 328 * @param proto_len length of the ip data part (used for checksum of pseudo header)
hendrikvincent 0:05ccbd4f84f1 329 * @return checksum (as u16_t) to be saved directly in the protocol header
hendrikvincent 0:05ccbd4f84f1 330 */
hendrikvincent 0:05ccbd4f84f1 331 u16_t
hendrikvincent 0:05ccbd4f84f1 332 inet_chksum_pseudo_partial(struct pbuf *p,
hendrikvincent 0:05ccbd4f84f1 333 ip_addr_t *src, ip_addr_t *dest,
hendrikvincent 0:05ccbd4f84f1 334 u8_t proto, u16_t proto_len, u16_t chksum_len)
hendrikvincent 0:05ccbd4f84f1 335 {
hendrikvincent 0:05ccbd4f84f1 336 u32_t acc;
hendrikvincent 0:05ccbd4f84f1 337 u32_t addr;
hendrikvincent 0:05ccbd4f84f1 338 struct pbuf *q;
hendrikvincent 0:05ccbd4f84f1 339 u8_t swapped;
hendrikvincent 0:05ccbd4f84f1 340 u16_t chklen;
hendrikvincent 0:05ccbd4f84f1 341
hendrikvincent 0:05ccbd4f84f1 342 acc = 0;
hendrikvincent 0:05ccbd4f84f1 343 swapped = 0;
hendrikvincent 0:05ccbd4f84f1 344 /* iterate through all pbuf in chain */
hendrikvincent 0:05ccbd4f84f1 345 for(q = p; (q != NULL) && (chksum_len > 0); q = q->next) {
hendrikvincent 0:05ccbd4f84f1 346 LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): checksumming pbuf %p (has next %p) \n",
hendrikvincent 0:05ccbd4f84f1 347 (void *)q, (void *)q->next));
hendrikvincent 0:05ccbd4f84f1 348 chklen = q->len;
hendrikvincent 0:05ccbd4f84f1 349 if (chklen > chksum_len) {
hendrikvincent 0:05ccbd4f84f1 350 chklen = chksum_len;
hendrikvincent 0:05ccbd4f84f1 351 }
hendrikvincent 0:05ccbd4f84f1 352 acc += LWIP_CHKSUM(q->payload, chklen);
hendrikvincent 0:05ccbd4f84f1 353 chksum_len -= chklen;
hendrikvincent 0:05ccbd4f84f1 354 LWIP_ASSERT("delete me", chksum_len < 0x7fff);
hendrikvincent 0:05ccbd4f84f1 355 /*LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): unwrapped lwip_chksum()=%"X32_F" \n", acc));*/
hendrikvincent 0:05ccbd4f84f1 356 /* fold the upper bit down */
hendrikvincent 0:05ccbd4f84f1 357 acc = FOLD_U32T(acc);
hendrikvincent 0:05ccbd4f84f1 358 if (q->len % 2 != 0) {
hendrikvincent 0:05ccbd4f84f1 359 swapped = 1 - swapped;
hendrikvincent 0:05ccbd4f84f1 360 acc = SWAP_BYTES_IN_WORD(acc);
hendrikvincent 0:05ccbd4f84f1 361 }
hendrikvincent 0:05ccbd4f84f1 362 /*LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): wrapped lwip_chksum()=%"X32_F" \n", acc));*/
hendrikvincent 0:05ccbd4f84f1 363 }
hendrikvincent 0:05ccbd4f84f1 364
hendrikvincent 0:05ccbd4f84f1 365 if (swapped) {
hendrikvincent 0:05ccbd4f84f1 366 acc = SWAP_BYTES_IN_WORD(acc);
hendrikvincent 0:05ccbd4f84f1 367 }
hendrikvincent 0:05ccbd4f84f1 368 addr = ip4_addr_get_u32(src);
hendrikvincent 0:05ccbd4f84f1 369 acc += (addr & 0xffffUL);
hendrikvincent 0:05ccbd4f84f1 370 acc += ((addr >> 16) & 0xffffUL);
hendrikvincent 0:05ccbd4f84f1 371 addr = ip4_addr_get_u32(dest);
hendrikvincent 0:05ccbd4f84f1 372 acc += (addr & 0xffffUL);
hendrikvincent 0:05ccbd4f84f1 373 acc += ((addr >> 16) & 0xffffUL);
hendrikvincent 0:05ccbd4f84f1 374 acc += (u32_t)htons((u16_t)proto);
hendrikvincent 0:05ccbd4f84f1 375 acc += (u32_t)htons(proto_len);
hendrikvincent 0:05ccbd4f84f1 376
hendrikvincent 0:05ccbd4f84f1 377 /* Fold 32-bit sum to 16 bits
hendrikvincent 0:05ccbd4f84f1 378 calling this twice is propably faster than if statements... */
hendrikvincent 0:05ccbd4f84f1 379 acc = FOLD_U32T(acc);
hendrikvincent 0:05ccbd4f84f1 380 acc = FOLD_U32T(acc);
hendrikvincent 0:05ccbd4f84f1 381 LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): pbuf chain lwip_chksum()=%"X32_F"\n", acc));
hendrikvincent 0:05ccbd4f84f1 382 return (u16_t)~(acc & 0xffffUL);
hendrikvincent 0:05ccbd4f84f1 383 }
hendrikvincent 0:05ccbd4f84f1 384
hendrikvincent 0:05ccbd4f84f1 385 /* inet_chksum:
hendrikvincent 0:05ccbd4f84f1 386 *
hendrikvincent 0:05ccbd4f84f1 387 * Calculates the Internet checksum over a portion of memory. Used primarily for IP
hendrikvincent 0:05ccbd4f84f1 388 * and ICMP.
hendrikvincent 0:05ccbd4f84f1 389 *
hendrikvincent 0:05ccbd4f84f1 390 * @param dataptr start of the buffer to calculate the checksum (no alignment needed)
hendrikvincent 0:05ccbd4f84f1 391 * @param len length of the buffer to calculate the checksum
hendrikvincent 0:05ccbd4f84f1 392 * @return checksum (as u16_t) to be saved directly in the protocol header
hendrikvincent 0:05ccbd4f84f1 393 */
hendrikvincent 0:05ccbd4f84f1 394
hendrikvincent 0:05ccbd4f84f1 395 u16_t
hendrikvincent 0:05ccbd4f84f1 396 inet_chksum(void *dataptr, u16_t len)
hendrikvincent 0:05ccbd4f84f1 397 {
hendrikvincent 0:05ccbd4f84f1 398 return ~LWIP_CHKSUM(dataptr, len);
hendrikvincent 0:05ccbd4f84f1 399 }
hendrikvincent 0:05ccbd4f84f1 400
hendrikvincent 0:05ccbd4f84f1 401 /**
hendrikvincent 0:05ccbd4f84f1 402 * Calculate a checksum over a chain of pbufs (without pseudo-header, much like
hendrikvincent 0:05ccbd4f84f1 403 * inet_chksum only pbufs are used).
hendrikvincent 0:05ccbd4f84f1 404 *
hendrikvincent 0:05ccbd4f84f1 405 * @param p pbuf chain over that the checksum should be calculated
hendrikvincent 0:05ccbd4f84f1 406 * @return checksum (as u16_t) to be saved directly in the protocol header
hendrikvincent 0:05ccbd4f84f1 407 */
hendrikvincent 0:05ccbd4f84f1 408 u16_t
hendrikvincent 0:05ccbd4f84f1 409 inet_chksum_pbuf(struct pbuf *p)
hendrikvincent 0:05ccbd4f84f1 410 {
hendrikvincent 0:05ccbd4f84f1 411 u32_t acc;
hendrikvincent 0:05ccbd4f84f1 412 struct pbuf *q;
hendrikvincent 0:05ccbd4f84f1 413 u8_t swapped;
hendrikvincent 0:05ccbd4f84f1 414
hendrikvincent 0:05ccbd4f84f1 415 acc = 0;
hendrikvincent 0:05ccbd4f84f1 416 swapped = 0;
hendrikvincent 0:05ccbd4f84f1 417 for(q = p; q != NULL; q = q->next) {
hendrikvincent 0:05ccbd4f84f1 418 acc += LWIP_CHKSUM(q->payload, q->len);
hendrikvincent 0:05ccbd4f84f1 419 acc = FOLD_U32T(acc);
hendrikvincent 0:05ccbd4f84f1 420 if (q->len % 2 != 0) {
hendrikvincent 0:05ccbd4f84f1 421 swapped = 1 - swapped;
hendrikvincent 0:05ccbd4f84f1 422 acc = SWAP_BYTES_IN_WORD(acc);
hendrikvincent 0:05ccbd4f84f1 423 }
hendrikvincent 0:05ccbd4f84f1 424 }
hendrikvincent 0:05ccbd4f84f1 425
hendrikvincent 0:05ccbd4f84f1 426 if (swapped) {
hendrikvincent 0:05ccbd4f84f1 427 acc = SWAP_BYTES_IN_WORD(acc);
hendrikvincent 0:05ccbd4f84f1 428 }
hendrikvincent 0:05ccbd4f84f1 429 return (u16_t)~(acc & 0xffffUL);
hendrikvincent 0:05ccbd4f84f1 430 }
hendrikvincent 0:05ccbd4f84f1 431
hendrikvincent 0:05ccbd4f84f1 432 /* These are some implementations for LWIP_CHKSUM_COPY, which copies data
hendrikvincent 0:05ccbd4f84f1 433 * like MEMCPY but generates a checksum at the same time. Since this is a
hendrikvincent 0:05ccbd4f84f1 434 * performance-sensitive function, you might want to create your own version
hendrikvincent 0:05ccbd4f84f1 435 * in assembly targeted at your hardware by defining it in lwipopts.h:
hendrikvincent 0:05ccbd4f84f1 436 * #define LWIP_CHKSUM_COPY(dst, src, len) your_chksum_copy(dst, src, len)
hendrikvincent 0:05ccbd4f84f1 437 */
hendrikvincent 0:05ccbd4f84f1 438
hendrikvincent 0:05ccbd4f84f1 439 #if (LWIP_CHKSUM_COPY_ALGORITHM == 1) /* Version #1 */
hendrikvincent 0:05ccbd4f84f1 440 /** Safe but slow: first call MEMCPY, then call LWIP_CHKSUM.
hendrikvincent 0:05ccbd4f84f1 441 * For architectures with big caches, data might still be in cache when
hendrikvincent 0:05ccbd4f84f1 442 * generating the checksum after copying.
hendrikvincent 0:05ccbd4f84f1 443 */
hendrikvincent 0:05ccbd4f84f1 444 u16_t
hendrikvincent 0:05ccbd4f84f1 445 lwip_chksum_copy(void *dst, const void *src, u16_t len)
hendrikvincent 0:05ccbd4f84f1 446 {
hendrikvincent 0:05ccbd4f84f1 447 MEMCPY(dst, src, len);
hendrikvincent 0:05ccbd4f84f1 448 return LWIP_CHKSUM(dst, len);
hendrikvincent 0:05ccbd4f84f1 449 }
hendrikvincent 0:05ccbd4f84f1 450 #endif /* (LWIP_CHKSUM_COPY_ALGORITHM == 1) */