mbed unsupported / lwip

A version of LWIP, provided for backwards compatibility.

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trunk/Core/lwIP/core/ipv4/inet_chksum.c@0:5e1631496985, 2012-05-08 (annotated)

Committer:
root@mbed.org
Date:
Tue May 08 15:32:10 2012 +0100
Revision:
0:5e1631496985
initial commit

Who changed what in which revision?

UserRevisionLine numberNew contents of line
root@mbed.org 0:5e1631496985 1 /**
root@mbed.org 0:5e1631496985 2 * @file
root@mbed.org 0:5e1631496985 3 * Incluse internet checksum functions.
root@mbed.org 0:5e1631496985 4 *
root@mbed.org 0:5e1631496985 5 */
root@mbed.org 0:5e1631496985 6
root@mbed.org 0:5e1631496985 7 /*
root@mbed.org 0:5e1631496985 8 * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
root@mbed.org 0:5e1631496985 9 * All rights reserved.
root@mbed.org 0:5e1631496985 10 *
root@mbed.org 0:5e1631496985 11 * Redistribution and use in source and binary forms, with or without modification,
root@mbed.org 0:5e1631496985 12 * are permitted provided that the following conditions are met:
root@mbed.org 0:5e1631496985 13 *
root@mbed.org 0:5e1631496985 14 * 1. Redistributions of source code must retain the above copyright notice,
root@mbed.org 0:5e1631496985 15 * this list of conditions and the following disclaimer.
root@mbed.org 0:5e1631496985 16 * 2. Redistributions in binary form must reproduce the above copyright notice,
root@mbed.org 0:5e1631496985 17 * this list of conditions and the following disclaimer in the documentation
root@mbed.org 0:5e1631496985 18 * and/or other materials provided with the distribution.
root@mbed.org 0:5e1631496985 19 * 3. The name of the author may not be used to endorse or promote products
root@mbed.org 0:5e1631496985 20 * derived from this software without specific prior written permission.
root@mbed.org 0:5e1631496985 21 *
root@mbed.org 0:5e1631496985 22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
root@mbed.org 0:5e1631496985 23 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
root@mbed.org 0:5e1631496985 24 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
root@mbed.org 0:5e1631496985 25 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
root@mbed.org 0:5e1631496985 26 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
root@mbed.org 0:5e1631496985 27 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
root@mbed.org 0:5e1631496985 28 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
root@mbed.org 0:5e1631496985 29 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
root@mbed.org 0:5e1631496985 30 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
root@mbed.org 0:5e1631496985 31 * OF SUCH DAMAGE.
root@mbed.org 0:5e1631496985 32 *
root@mbed.org 0:5e1631496985 33 * This file is part of the lwIP TCP/IP stack.
root@mbed.org 0:5e1631496985 34 *
root@mbed.org 0:5e1631496985 35 * Author: Adam Dunkels <adam@sics.se>
root@mbed.org 0:5e1631496985 36 *
root@mbed.org 0:5e1631496985 37 */
root@mbed.org 0:5e1631496985 38
root@mbed.org 0:5e1631496985 39 #include "lwip/opt.h"
root@mbed.org 0:5e1631496985 40
root@mbed.org 0:5e1631496985 41 #include "lwip/inet_chksum.h"
root@mbed.org 0:5e1631496985 42 #include "lwip/inet.h"
root@mbed.org 0:5e1631496985 43
root@mbed.org 0:5e1631496985 44 #include <stddef.h>
root@mbed.org 0:5e1631496985 45
root@mbed.org 0:5e1631496985 46 /* These are some reference implementations of the checksum algorithm, with the
root@mbed.org 0:5e1631496985 47 * aim of being simple, correct and fully portable. Checksumming is the
root@mbed.org 0:5e1631496985 48 * first thing you would want to optimize for your platform. If you create
root@mbed.org 0:5e1631496985 49 * your own version, link it in and in your cc.h put:
root@mbed.org 0:5e1631496985 50 *
root@mbed.org 0:5e1631496985 51 * #define LWIP_CHKSUM <your_checksum_routine>
root@mbed.org 0:5e1631496985 52 *
root@mbed.org 0:5e1631496985 53 * Or you can select from the implementations below by defining
root@mbed.org 0:5e1631496985 54 * LWIP_CHKSUM_ALGORITHM to 1, 2 or 3.
root@mbed.org 0:5e1631496985 55 */
root@mbed.org 0:5e1631496985 56
root@mbed.org 0:5e1631496985 57 #ifndef LWIP_CHKSUM
root@mbed.org 0:5e1631496985 58 # define LWIP_CHKSUM lwip_standard_chksum
root@mbed.org 0:5e1631496985 59 # ifndef LWIP_CHKSUM_ALGORITHM
root@mbed.org 0:5e1631496985 60 # define LWIP_CHKSUM_ALGORITHM 1
root@mbed.org 0:5e1631496985 61 # endif
root@mbed.org 0:5e1631496985 62 #endif
root@mbed.org 0:5e1631496985 63 /* If none set: */
root@mbed.org 0:5e1631496985 64 #ifndef LWIP_CHKSUM_ALGORITHM
root@mbed.org 0:5e1631496985 65 # define LWIP_CHKSUM_ALGORITHM 0
root@mbed.org 0:5e1631496985 66 #endif
root@mbed.org 0:5e1631496985 67
root@mbed.org 0:5e1631496985 68 /** Like the name says... */
root@mbed.org 0:5e1631496985 69 #if LWIP_PLATFORM_BYTESWAP && (BYTE_ORDER == LITTLE_ENDIAN)
root@mbed.org 0:5e1631496985 70 /* little endian and PLATFORM_BYTESWAP defined */
root@mbed.org 0:5e1631496985 71 #define SWAP_BYTES_IN_WORD(w) LWIP_PLATFORM_HTONS(w)
root@mbed.org 0:5e1631496985 72 #else
root@mbed.org 0:5e1631496985 73 /* can't use htons on big endian (or PLATFORM_BYTESWAP not defined)... */
root@mbed.org 0:5e1631496985 74 #define SWAP_BYTES_IN_WORD(w) ((w & 0xff) << 8) | ((w & 0xff00) >> 8)
root@mbed.org 0:5e1631496985 75 #endif
root@mbed.org 0:5e1631496985 76
root@mbed.org 0:5e1631496985 77 /** Split an u32_t in two u16_ts and add them up */
root@mbed.org 0:5e1631496985 78 #define FOLD_U32T(u) ((u >> 16) + (u & 0x0000ffffUL))
root@mbed.org 0:5e1631496985 79
root@mbed.org 0:5e1631496985 80 #if (LWIP_CHKSUM_ALGORITHM == 1) /* Version #1 */
root@mbed.org 0:5e1631496985 81 /**
root@mbed.org 0:5e1631496985 82 * lwip checksum
root@mbed.org 0:5e1631496985 83 *
root@mbed.org 0:5e1631496985 84 * @param dataptr points to start of data to be summed at any boundary
root@mbed.org 0:5e1631496985 85 * @param len length of data to be summed
root@mbed.org 0:5e1631496985 86 * @return host order (!) lwip checksum (non-inverted Internet sum)
root@mbed.org 0:5e1631496985 87 *
root@mbed.org 0:5e1631496985 88 * @note accumulator size limits summable length to 64k
root@mbed.org 0:5e1631496985 89 * @note host endianess is irrelevant (p3 RFC1071)
root@mbed.org 0:5e1631496985 90 */
root@mbed.org 0:5e1631496985 91 static u16_t
root@mbed.org 0:5e1631496985 92 lwip_standard_chksum(void *dataptr, u16_t len)
root@mbed.org 0:5e1631496985 93 {
root@mbed.org 0:5e1631496985 94 u32_t acc;
root@mbed.org 0:5e1631496985 95 u16_t src;
root@mbed.org 0:5e1631496985 96 u8_t *octetptr;
root@mbed.org 0:5e1631496985 97
root@mbed.org 0:5e1631496985 98 acc = 0;
root@mbed.org 0:5e1631496985 99 /* dataptr may be at odd or even addresses */
root@mbed.org 0:5e1631496985 100 octetptr = (u8_t*)dataptr;
root@mbed.org 0:5e1631496985 101 while (len > 1) {
root@mbed.org 0:5e1631496985 102 /* declare first octet as most significant
root@mbed.org 0:5e1631496985 103 thus assume network order, ignoring host order */
root@mbed.org 0:5e1631496985 104 src = (*octetptr) << 8;
root@mbed.org 0:5e1631496985 105 octetptr++;
root@mbed.org 0:5e1631496985 106 /* declare second octet as least significant */
root@mbed.org 0:5e1631496985 107 src |= (*octetptr);
root@mbed.org 0:5e1631496985 108 octetptr++;
root@mbed.org 0:5e1631496985 109 acc += src;
root@mbed.org 0:5e1631496985 110 len -= 2;
root@mbed.org 0:5e1631496985 111 }
root@mbed.org 0:5e1631496985 112 if (len > 0) {
root@mbed.org 0:5e1631496985 113 /* accumulate remaining octet */
root@mbed.org 0:5e1631496985 114 src = (*octetptr) << 8;
root@mbed.org 0:5e1631496985 115 acc += src;
root@mbed.org 0:5e1631496985 116 }
root@mbed.org 0:5e1631496985 117 /* add deferred carry bits */
root@mbed.org 0:5e1631496985 118 acc = (acc >> 16) + (acc & 0x0000ffffUL);
root@mbed.org 0:5e1631496985 119 if ((acc & 0xffff0000UL) != 0) {
root@mbed.org 0:5e1631496985 120 acc = (acc >> 16) + (acc & 0x0000ffffUL);
root@mbed.org 0:5e1631496985 121 }
root@mbed.org 0:5e1631496985 122 /* This maybe a little confusing: reorder sum using htons()
root@mbed.org 0:5e1631496985 123 instead of ntohs() since it has a little less call overhead.
root@mbed.org 0:5e1631496985 124 The caller must invert bits for Internet sum ! */
root@mbed.org 0:5e1631496985 125 return htons((u16_t)acc);
root@mbed.org 0:5e1631496985 126 }
root@mbed.org 0:5e1631496985 127 #endif
root@mbed.org 0:5e1631496985 128
root@mbed.org 0:5e1631496985 129 #if (LWIP_CHKSUM_ALGORITHM == 2) /* Alternative version #2 */
root@mbed.org 0:5e1631496985 130 /*
root@mbed.org 0:5e1631496985 131 * Curt McDowell
root@mbed.org 0:5e1631496985 132 * Broadcom Corp.
root@mbed.org 0:5e1631496985 133 * csm@broadcom.com
root@mbed.org 0:5e1631496985 134 *
root@mbed.org 0:5e1631496985 135 * IP checksum two bytes at a time with support for
root@mbed.org 0:5e1631496985 136 * unaligned buffer.
root@mbed.org 0:5e1631496985 137 * Works for len up to and including 0x20000.
root@mbed.org 0:5e1631496985 138 * by Curt McDowell, Broadcom Corp. 12/08/2005
root@mbed.org 0:5e1631496985 139 *
root@mbed.org 0:5e1631496985 140 * @param dataptr points to start of data to be summed at any boundary
root@mbed.org 0:5e1631496985 141 * @param len length of data to be summed
root@mbed.org 0:5e1631496985 142 * @return host order (!) lwip checksum (non-inverted Internet sum)
root@mbed.org 0:5e1631496985 143 */
root@mbed.org 0:5e1631496985 144
root@mbed.org 0:5e1631496985 145 static u16_t
root@mbed.org 0:5e1631496985 146 lwip_standard_chksum(void *dataptr, int len)
root@mbed.org 0:5e1631496985 147 {
root@mbed.org 0:5e1631496985 148 u8_t *pb = dataptr;
root@mbed.org 0:5e1631496985 149 u16_t *ps, t = 0;
root@mbed.org 0:5e1631496985 150 u32_t sum = 0;
root@mbed.org 0:5e1631496985 151 int odd = ((u32_t)pb & 1);
root@mbed.org 0:5e1631496985 152
root@mbed.org 0:5e1631496985 153 /* Get aligned to u16_t */
root@mbed.org 0:5e1631496985 154 if (odd && len > 0) {
root@mbed.org 0:5e1631496985 155 ((u8_t *)&t)[1] = *pb++;
root@mbed.org 0:5e1631496985 156 len--;
root@mbed.org 0:5e1631496985 157 }
root@mbed.org 0:5e1631496985 158
root@mbed.org 0:5e1631496985 159 /* Add the bulk of the data */
root@mbed.org 0:5e1631496985 160 ps = (u16_t *)pb;
root@mbed.org 0:5e1631496985 161 while (len > 1) {
root@mbed.org 0:5e1631496985 162 sum += *ps++;
root@mbed.org 0:5e1631496985 163 len -= 2;
root@mbed.org 0:5e1631496985 164 }
root@mbed.org 0:5e1631496985 165
root@mbed.org 0:5e1631496985 166 /* Consume left-over byte, if any */
root@mbed.org 0:5e1631496985 167 if (len > 0) {
root@mbed.org 0:5e1631496985 168 ((u8_t *)&t)[0] = *(u8_t *)ps;;
root@mbed.org 0:5e1631496985 169 }
root@mbed.org 0:5e1631496985 170
root@mbed.org 0:5e1631496985 171 /* Add end bytes */
root@mbed.org 0:5e1631496985 172 sum += t;
root@mbed.org 0:5e1631496985 173
root@mbed.org 0:5e1631496985 174 /* Fold 32-bit sum to 16 bits
root@mbed.org 0:5e1631496985 175 calling this twice is propably faster than if statements... */
root@mbed.org 0:5e1631496985 176 sum = FOLD_U32T(sum);
root@mbed.org 0:5e1631496985 177 sum = FOLD_U32T(sum);
root@mbed.org 0:5e1631496985 178
root@mbed.org 0:5e1631496985 179 /* Swap if alignment was odd */
root@mbed.org 0:5e1631496985 180 if (odd) {
root@mbed.org 0:5e1631496985 181 sum = SWAP_BYTES_IN_WORD(sum);
root@mbed.org 0:5e1631496985 182 }
root@mbed.org 0:5e1631496985 183
root@mbed.org 0:5e1631496985 184 return sum;
root@mbed.org 0:5e1631496985 185 }
root@mbed.org 0:5e1631496985 186 #endif
root@mbed.org 0:5e1631496985 187
root@mbed.org 0:5e1631496985 188 #if (LWIP_CHKSUM_ALGORITHM == 3) /* Alternative version #3 */
root@mbed.org 0:5e1631496985 189 /**
root@mbed.org 0:5e1631496985 190 * An optimized checksum routine. Basically, it uses loop-unrolling on
root@mbed.org 0:5e1631496985 191 * the checksum loop, treating the head and tail bytes specially, whereas
root@mbed.org 0:5e1631496985 192 * the inner loop acts on 8 bytes at a time.
root@mbed.org 0:5e1631496985 193 *
root@mbed.org 0:5e1631496985 194 * @arg start of buffer to be checksummed. May be an odd byte address.
root@mbed.org 0:5e1631496985 195 * @len number of bytes in the buffer to be checksummed.
root@mbed.org 0:5e1631496985 196 * @return host order (!) lwip checksum (non-inverted Internet sum)
root@mbed.org 0:5e1631496985 197 *
root@mbed.org 0:5e1631496985 198 * by Curt McDowell, Broadcom Corp. December 8th, 2005
root@mbed.org 0:5e1631496985 199 */
root@mbed.org 0:5e1631496985 200
root@mbed.org 0:5e1631496985 201 static u16_t
root@mbed.org 0:5e1631496985 202 lwip_standard_chksum(void *dataptr, int len)
root@mbed.org 0:5e1631496985 203 {
root@mbed.org 0:5e1631496985 204 u8_t *pb = dataptr;
root@mbed.org 0:5e1631496985 205 u16_t *ps, t = 0;
root@mbed.org 0:5e1631496985 206 u32_t *pl;
root@mbed.org 0:5e1631496985 207 u32_t sum = 0, tmp;
root@mbed.org 0:5e1631496985 208 /* starts at odd byte address? */
root@mbed.org 0:5e1631496985 209 int odd = ((u32_t)pb & 1);
root@mbed.org 0:5e1631496985 210
root@mbed.org 0:5e1631496985 211 if (odd && len > 0) {
root@mbed.org 0:5e1631496985 212 ((u8_t *)&t)[1] = *pb++;
root@mbed.org 0:5e1631496985 213 len--;
root@mbed.org 0:5e1631496985 214 }
root@mbed.org 0:5e1631496985 215
root@mbed.org 0:5e1631496985 216 ps = (u16_t *)pb;
root@mbed.org 0:5e1631496985 217
root@mbed.org 0:5e1631496985 218 if (((u32_t)ps & 3) && len > 1) {
root@mbed.org 0:5e1631496985 219 sum += *ps++;
root@mbed.org 0:5e1631496985 220 len -= 2;
root@mbed.org 0:5e1631496985 221 }
root@mbed.org 0:5e1631496985 222
root@mbed.org 0:5e1631496985 223 pl = (u32_t *)ps;
root@mbed.org 0:5e1631496985 224
root@mbed.org 0:5e1631496985 225 while (len > 7) {
root@mbed.org 0:5e1631496985 226 tmp = sum + *pl++; /* ping */
root@mbed.org 0:5e1631496985 227 if (tmp < sum) {
root@mbed.org 0:5e1631496985 228 tmp++; /* add back carry */
root@mbed.org 0:5e1631496985 229 }
root@mbed.org 0:5e1631496985 230
root@mbed.org 0:5e1631496985 231 sum = tmp + *pl++; /* pong */
root@mbed.org 0:5e1631496985 232 if (sum < tmp) {
root@mbed.org 0:5e1631496985 233 sum++; /* add back carry */
root@mbed.org 0:5e1631496985 234 }
root@mbed.org 0:5e1631496985 235
root@mbed.org 0:5e1631496985 236 len -= 8;
root@mbed.org 0:5e1631496985 237 }
root@mbed.org 0:5e1631496985 238
root@mbed.org 0:5e1631496985 239 /* make room in upper bits */
root@mbed.org 0:5e1631496985 240 sum = FOLD_U32T(sum);
root@mbed.org 0:5e1631496985 241
root@mbed.org 0:5e1631496985 242 ps = (u16_t *)pl;
root@mbed.org 0:5e1631496985 243
root@mbed.org 0:5e1631496985 244 /* 16-bit aligned word remaining? */
root@mbed.org 0:5e1631496985 245 while (len > 1) {
root@mbed.org 0:5e1631496985 246 sum += *ps++;
root@mbed.org 0:5e1631496985 247 len -= 2;
root@mbed.org 0:5e1631496985 248 }
root@mbed.org 0:5e1631496985 249
root@mbed.org 0:5e1631496985 250 /* dangling tail byte remaining? */
root@mbed.org 0:5e1631496985 251 if (len > 0) { /* include odd byte */
root@mbed.org 0:5e1631496985 252 ((u8_t *)&t)[0] = *(u8_t *)ps;
root@mbed.org 0:5e1631496985 253 }
root@mbed.org 0:5e1631496985 254
root@mbed.org 0:5e1631496985 255 sum += t; /* add end bytes */
root@mbed.org 0:5e1631496985 256
root@mbed.org 0:5e1631496985 257 /* Fold 32-bit sum to 16 bits
root@mbed.org 0:5e1631496985 258 calling this twice is propably faster than if statements... */
root@mbed.org 0:5e1631496985 259 sum = FOLD_U32T(sum);
root@mbed.org 0:5e1631496985 260 sum = FOLD_U32T(sum);
root@mbed.org 0:5e1631496985 261
root@mbed.org 0:5e1631496985 262 if (odd) {
root@mbed.org 0:5e1631496985 263 sum = SWAP_BYTES_IN_WORD(sum);
root@mbed.org 0:5e1631496985 264 }
root@mbed.org 0:5e1631496985 265
root@mbed.org 0:5e1631496985 266 return sum;
root@mbed.org 0:5e1631496985 267 }
root@mbed.org 0:5e1631496985 268 #endif
root@mbed.org 0:5e1631496985 269
root@mbed.org 0:5e1631496985 270 /* inet_chksum_pseudo:
root@mbed.org 0:5e1631496985 271 *
root@mbed.org 0:5e1631496985 272 * Calculates the pseudo Internet checksum used by TCP and UDP for a pbuf chain.
root@mbed.org 0:5e1631496985 273 * IP addresses are expected to be in network byte order.
root@mbed.org 0:5e1631496985 274 *
root@mbed.org 0:5e1631496985 275 * @param p chain of pbufs over that a checksum should be calculated (ip data part)
root@mbed.org 0:5e1631496985 276 * @param src source ip address (used for checksum of pseudo header)
root@mbed.org 0:5e1631496985 277 * @param dst destination ip address (used for checksum of pseudo header)
root@mbed.org 0:5e1631496985 278 * @param proto ip protocol (used for checksum of pseudo header)
root@mbed.org 0:5e1631496985 279 * @param proto_len length of the ip data part (used for checksum of pseudo header)
root@mbed.org 0:5e1631496985 280 * @return checksum (as u16_t) to be saved directly in the protocol header
root@mbed.org 0:5e1631496985 281 */
root@mbed.org 0:5e1631496985 282 u16_t
root@mbed.org 0:5e1631496985 283 inet_chksum_pseudo(struct pbuf *p,
root@mbed.org 0:5e1631496985 284 struct ip_addr *src, struct ip_addr *dest,
root@mbed.org 0:5e1631496985 285 u8_t proto, u16_t proto_len)
root@mbed.org 0:5e1631496985 286 {
root@mbed.org 0:5e1631496985 287 u32_t acc;
root@mbed.org 0:5e1631496985 288 struct pbuf *q;
root@mbed.org 0:5e1631496985 289 u8_t swapped;
root@mbed.org 0:5e1631496985 290
root@mbed.org 0:5e1631496985 291 acc = 0;
root@mbed.org 0:5e1631496985 292 swapped = 0;
root@mbed.org 0:5e1631496985 293 /* iterate through all pbuf in chain */
root@mbed.org 0:5e1631496985 294 for(q = p; q != NULL; q = q->next) {
root@mbed.org 0:5e1631496985 295 LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): checksumming pbuf %p (has next %p) \n",
root@mbed.org 0:5e1631496985 296 (void *)q, (void *)q->next));
root@mbed.org 0:5e1631496985 297 acc += LWIP_CHKSUM(q->payload, q->len);
root@mbed.org 0:5e1631496985 298 /*LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): unwrapped lwip_chksum()=%"X32_F" \n", acc));*/
root@mbed.org 0:5e1631496985 299 /* just executing this next line is probably faster that the if statement needed
root@mbed.org 0:5e1631496985 300 to check whether we really need to execute it, and does no harm */
root@mbed.org 0:5e1631496985 301 acc = FOLD_U32T(acc);
root@mbed.org 0:5e1631496985 302 if (q->len % 2 != 0) {
root@mbed.org 0:5e1631496985 303 swapped = 1 - swapped;
root@mbed.org 0:5e1631496985 304 acc = SWAP_BYTES_IN_WORD(acc);
root@mbed.org 0:5e1631496985 305 }
root@mbed.org 0:5e1631496985 306 /*LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): wrapped lwip_chksum()=%"X32_F" \n", acc));*/
root@mbed.org 0:5e1631496985 307 }
root@mbed.org 0:5e1631496985 308
root@mbed.org 0:5e1631496985 309 if (swapped) {
root@mbed.org 0:5e1631496985 310 acc = SWAP_BYTES_IN_WORD(acc);
root@mbed.org 0:5e1631496985 311 }
root@mbed.org 0:5e1631496985 312 acc += (src->addr & 0xffffUL);
root@mbed.org 0:5e1631496985 313 acc += ((src->addr >> 16) & 0xffffUL);
root@mbed.org 0:5e1631496985 314 acc += (dest->addr & 0xffffUL);
root@mbed.org 0:5e1631496985 315 acc += ((dest->addr >> 16) & 0xffffUL);
root@mbed.org 0:5e1631496985 316 acc += (u32_t)htons((u16_t)proto);
root@mbed.org 0:5e1631496985 317 acc += (u32_t)htons(proto_len);
root@mbed.org 0:5e1631496985 318
root@mbed.org 0:5e1631496985 319 /* Fold 32-bit sum to 16 bits
root@mbed.org 0:5e1631496985 320 calling this twice is propably faster than if statements... */
root@mbed.org 0:5e1631496985 321 acc = FOLD_U32T(acc);
root@mbed.org 0:5e1631496985 322 acc = FOLD_U32T(acc);
root@mbed.org 0:5e1631496985 323 LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): pbuf chain lwip_chksum()=%"X32_F"\n", acc));
root@mbed.org 0:5e1631496985 324 return (u16_t)~(acc & 0xffffUL);
root@mbed.org 0:5e1631496985 325 }
root@mbed.org 0:5e1631496985 326
root@mbed.org 0:5e1631496985 327 /* inet_chksum_pseudo:
root@mbed.org 0:5e1631496985 328 *
root@mbed.org 0:5e1631496985 329 * Calculates the pseudo Internet checksum used by TCP and UDP for a pbuf chain.
root@mbed.org 0:5e1631496985 330 * IP addresses are expected to be in network byte order.
root@mbed.org 0:5e1631496985 331 *
root@mbed.org 0:5e1631496985 332 * @param p chain of pbufs over that a checksum should be calculated (ip data part)
root@mbed.org 0:5e1631496985 333 * @param src source ip address (used for checksum of pseudo header)
root@mbed.org 0:5e1631496985 334 * @param dst destination ip address (used for checksum of pseudo header)
root@mbed.org 0:5e1631496985 335 * @param proto ip protocol (used for checksum of pseudo header)
root@mbed.org 0:5e1631496985 336 * @param proto_len length of the ip data part (used for checksum of pseudo header)
root@mbed.org 0:5e1631496985 337 * @return checksum (as u16_t) to be saved directly in the protocol header
root@mbed.org 0:5e1631496985 338 */
root@mbed.org 0:5e1631496985 339 /* Currently only used by UDPLITE, although this could change in the future. */
root@mbed.org 0:5e1631496985 340 #if LWIP_UDPLITE
root@mbed.org 0:5e1631496985 341 u16_t
root@mbed.org 0:5e1631496985 342 inet_chksum_pseudo_partial(struct pbuf *p,
root@mbed.org 0:5e1631496985 343 struct ip_addr *src, struct ip_addr *dest,
root@mbed.org 0:5e1631496985 344 u8_t proto, u16_t proto_len, u16_t chksum_len)
root@mbed.org 0:5e1631496985 345 {
root@mbed.org 0:5e1631496985 346 u32_t acc;
root@mbed.org 0:5e1631496985 347 struct pbuf *q;
root@mbed.org 0:5e1631496985 348 u8_t swapped;
root@mbed.org 0:5e1631496985 349 u16_t chklen;
root@mbed.org 0:5e1631496985 350
root@mbed.org 0:5e1631496985 351 acc = 0;
root@mbed.org 0:5e1631496985 352 swapped = 0;
root@mbed.org 0:5e1631496985 353 /* iterate through all pbuf in chain */
root@mbed.org 0:5e1631496985 354 for(q = p; (q != NULL) && (chksum_len > 0); q = q->next) {
root@mbed.org 0:5e1631496985 355 LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): checksumming pbuf %p (has next %p) \n",
root@mbed.org 0:5e1631496985 356 (void *)q, (void *)q->next));
root@mbed.org 0:5e1631496985 357 chklen = q->len;
root@mbed.org 0:5e1631496985 358 if (chklen > chksum_len) {
root@mbed.org 0:5e1631496985 359 chklen = chksum_len;
root@mbed.org 0:5e1631496985 360 }
root@mbed.org 0:5e1631496985 361 acc += LWIP_CHKSUM(q->payload, chklen);
root@mbed.org 0:5e1631496985 362 chksum_len -= chklen;
root@mbed.org 0:5e1631496985 363 LWIP_ASSERT("delete me", chksum_len < 0x7fff);
root@mbed.org 0:5e1631496985 364 /*LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): unwrapped lwip_chksum()=%"X32_F" \n", acc));*/
root@mbed.org 0:5e1631496985 365 /* fold the upper bit down */
root@mbed.org 0:5e1631496985 366 acc = FOLD_U32T(acc);
root@mbed.org 0:5e1631496985 367 if (q->len % 2 != 0) {
root@mbed.org 0:5e1631496985 368 swapped = 1 - swapped;
root@mbed.org 0:5e1631496985 369 acc = SWAP_BYTES_IN_WORD(acc);
root@mbed.org 0:5e1631496985 370 }
root@mbed.org 0:5e1631496985 371 /*LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): wrapped lwip_chksum()=%"X32_F" \n", acc));*/
root@mbed.org 0:5e1631496985 372 }
root@mbed.org 0:5e1631496985 373
root@mbed.org 0:5e1631496985 374 if (swapped) {
root@mbed.org 0:5e1631496985 375 acc = SWAP_BYTES_IN_WORD(acc);
root@mbed.org 0:5e1631496985 376 }
root@mbed.org 0:5e1631496985 377 acc += (src->addr & 0xffffUL);
root@mbed.org 0:5e1631496985 378 acc += ((src->addr >> 16) & 0xffffUL);
root@mbed.org 0:5e1631496985 379 acc += (dest->addr & 0xffffUL);
root@mbed.org 0:5e1631496985 380 acc += ((dest->addr >> 16) & 0xffffUL);
root@mbed.org 0:5e1631496985 381 acc += (u32_t)htons((u16_t)proto);
root@mbed.org 0:5e1631496985 382 acc += (u32_t)htons(proto_len);
root@mbed.org 0:5e1631496985 383
root@mbed.org 0:5e1631496985 384 /* Fold 32-bit sum to 16 bits
root@mbed.org 0:5e1631496985 385 calling this twice is propably faster than if statements... */
root@mbed.org 0:5e1631496985 386 acc = FOLD_U32T(acc);
root@mbed.org 0:5e1631496985 387 acc = FOLD_U32T(acc);
root@mbed.org 0:5e1631496985 388 LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): pbuf chain lwip_chksum()=%"X32_F"\n", acc));
root@mbed.org 0:5e1631496985 389 return (u16_t)~(acc & 0xffffUL);
root@mbed.org 0:5e1631496985 390 }
root@mbed.org 0:5e1631496985 391 #endif /* LWIP_UDPLITE */
root@mbed.org 0:5e1631496985 392
root@mbed.org 0:5e1631496985 393 /* inet_chksum:
root@mbed.org 0:5e1631496985 394 *
root@mbed.org 0:5e1631496985 395 * Calculates the Internet checksum over a portion of memory. Used primarily for IP
root@mbed.org 0:5e1631496985 396 * and ICMP.
root@mbed.org 0:5e1631496985 397 *
root@mbed.org 0:5e1631496985 398 * @param dataptr start of the buffer to calculate the checksum (no alignment needed)
root@mbed.org 0:5e1631496985 399 * @param len length of the buffer to calculate the checksum
root@mbed.org 0:5e1631496985 400 * @return checksum (as u16_t) to be saved directly in the protocol header
root@mbed.org 0:5e1631496985 401 */
root@mbed.org 0:5e1631496985 402
root@mbed.org 0:5e1631496985 403 u16_t
root@mbed.org 0:5e1631496985 404 inet_chksum(void *dataptr, u16_t len)
root@mbed.org 0:5e1631496985 405 {
root@mbed.org 0:5e1631496985 406 return ~LWIP_CHKSUM(dataptr, len);
root@mbed.org 0:5e1631496985 407 }
root@mbed.org 0:5e1631496985 408
root@mbed.org 0:5e1631496985 409 /**
root@mbed.org 0:5e1631496985 410 * Calculate a checksum over a chain of pbufs (without pseudo-header, much like
root@mbed.org 0:5e1631496985 411 * inet_chksum only pbufs are used).
root@mbed.org 0:5e1631496985 412 *
root@mbed.org 0:5e1631496985 413 * @param p pbuf chain over that the checksum should be calculated
root@mbed.org 0:5e1631496985 414 * @return checksum (as u16_t) to be saved directly in the protocol header
root@mbed.org 0:5e1631496985 415 */
root@mbed.org 0:5e1631496985 416 u16_t
root@mbed.org 0:5e1631496985 417 inet_chksum_pbuf(struct pbuf *p)
root@mbed.org 0:5e1631496985 418 {
root@mbed.org 0:5e1631496985 419 u32_t acc;
root@mbed.org 0:5e1631496985 420 struct pbuf *q;
root@mbed.org 0:5e1631496985 421 u8_t swapped;
root@mbed.org 0:5e1631496985 422
root@mbed.org 0:5e1631496985 423 acc = 0;
root@mbed.org 0:5e1631496985 424 swapped = 0;
root@mbed.org 0:5e1631496985 425 for(q = p; q != NULL; q = q->next) {
root@mbed.org 0:5e1631496985 426 acc += LWIP_CHKSUM(q->payload, q->len);
root@mbed.org 0:5e1631496985 427 acc = FOLD_U32T(acc);
root@mbed.org 0:5e1631496985 428 if (q->len % 2 != 0) {
root@mbed.org 0:5e1631496985 429 swapped = 1 - swapped;
root@mbed.org 0:5e1631496985 430 acc = SWAP_BYTES_IN_WORD(acc);
root@mbed.org 0:5e1631496985 431 }
root@mbed.org 0:5e1631496985 432 }
root@mbed.org 0:5e1631496985 433
root@mbed.org 0:5e1631496985 434 if (swapped) {
root@mbed.org 0:5e1631496985 435 acc = SWAP_BYTES_IN_WORD(acc);
root@mbed.org 0:5e1631496985 436 }
root@mbed.org 0:5e1631496985 437 return (u16_t)~(acc & 0xffffUL);
root@mbed.org 0:5e1631496985 438 }