Donatien Garnier
ZG2100 Network interface source
lwip/core/ipv4/inet_chksum.c@0:b802fc31f1db, 2010-07-09 (annotated)
- Committer:
- donatien
- Date:
- Fri Jul 09 15:37:23 2010 +0000
- Revision:
- 0:b802fc31f1db
Who changed what in which revision?
| User | Revision | Line number | New contents of line |
|---|---|---|---|
| donatien | 0:b802fc31f1db | 1 | /** |
| donatien | 0:b802fc31f1db | 2 | * @file |
| donatien | 0:b802fc31f1db | 3 | * Incluse internet checksum functions. |
| donatien | 0:b802fc31f1db | 4 | * |
| donatien | 0:b802fc31f1db | 5 | */ |
| donatien | 0:b802fc31f1db | 6 | |
| donatien | 0:b802fc31f1db | 7 | /* |
| donatien | 0:b802fc31f1db | 8 | * Copyright (c) 2001-2004 Swedish Institute of Computer Science. |
| donatien | 0:b802fc31f1db | 9 | * All rights reserved. |
| donatien | 0:b802fc31f1db | 10 | * |
| donatien | 0:b802fc31f1db | 11 | * Redistribution and use in source and binary forms, with or without modification, |
| donatien | 0:b802fc31f1db | 12 | * are permitted provided that the following conditions are met: |
| donatien | 0:b802fc31f1db | 13 | * |
| donatien | 0:b802fc31f1db | 14 | * 1. Redistributions of source code must retain the above copyright notice, |
| donatien | 0:b802fc31f1db | 15 | * this list of conditions and the following disclaimer. |
| donatien | 0:b802fc31f1db | 16 | * 2. Redistributions in binary form must reproduce the above copyright notice, |
| donatien | 0:b802fc31f1db | 17 | * this list of conditions and the following disclaimer in the documentation |
| donatien | 0:b802fc31f1db | 18 | * and/or other materials provided with the distribution. |
| donatien | 0:b802fc31f1db | 19 | * 3. The name of the author may not be used to endorse or promote products |
| donatien | 0:b802fc31f1db | 20 | * derived from this software without specific prior written permission. |
| donatien | 0:b802fc31f1db | 21 | * |
| donatien | 0:b802fc31f1db | 22 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED |
| donatien | 0:b802fc31f1db | 23 | * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF |
| donatien | 0:b802fc31f1db | 24 | * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT |
| donatien | 0:b802fc31f1db | 25 | * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, |
| donatien | 0:b802fc31f1db | 26 | * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT |
| donatien | 0:b802fc31f1db | 27 | * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| donatien | 0:b802fc31f1db | 28 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| donatien | 0:b802fc31f1db | 29 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING |
| donatien | 0:b802fc31f1db | 30 | * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY |
| donatien | 0:b802fc31f1db | 31 | * OF SUCH DAMAGE. |
| donatien | 0:b802fc31f1db | 32 | * |
| donatien | 0:b802fc31f1db | 33 | * This file is part of the lwIP TCP/IP stack. |
| donatien | 0:b802fc31f1db | 34 | * |
| donatien | 0:b802fc31f1db | 35 | * Author: Adam Dunkels <adam@sics.se> |
| donatien | 0:b802fc31f1db | 36 | * |
| donatien | 0:b802fc31f1db | 37 | */ |
| donatien | 0:b802fc31f1db | 38 | |
| donatien | 0:b802fc31f1db | 39 | #include "lwip/opt.h" |
| donatien | 0:b802fc31f1db | 40 | |
| donatien | 0:b802fc31f1db | 41 | #include "lwip/inet_chksum.h" |
| donatien | 0:b802fc31f1db | 42 | #include "lwip/def.h" |
| donatien | 0:b802fc31f1db | 43 | |
| donatien | 0:b802fc31f1db | 44 | #include <stddef.h> |
| donatien | 0:b802fc31f1db | 45 | #include <string.h> |
| donatien | 0:b802fc31f1db | 46 | |
| donatien | 0:b802fc31f1db | 47 | /* These are some reference implementations of the checksum algorithm, with the |
| donatien | 0:b802fc31f1db | 48 | * aim of being simple, correct and fully portable. Checksumming is the |
| donatien | 0:b802fc31f1db | 49 | * first thing you would want to optimize for your platform. If you create |
| donatien | 0:b802fc31f1db | 50 | * your own version, link it in and in your cc.h put: |
| donatien | 0:b802fc31f1db | 51 | * |
| donatien | 0:b802fc31f1db | 52 | * #define LWIP_CHKSUM <your_checksum_routine> |
| donatien | 0:b802fc31f1db | 53 | * |
| donatien | 0:b802fc31f1db | 54 | * Or you can select from the implementations below by defining |
| donatien | 0:b802fc31f1db | 55 | * LWIP_CHKSUM_ALGORITHM to 1, 2 or 3. |
| donatien | 0:b802fc31f1db | 56 | */ |
| donatien | 0:b802fc31f1db | 57 | |
| donatien | 0:b802fc31f1db | 58 | #ifndef LWIP_CHKSUM |
| donatien | 0:b802fc31f1db | 59 | # define LWIP_CHKSUM lwip_standard_chksum |
| donatien | 0:b802fc31f1db | 60 | # ifndef LWIP_CHKSUM_ALGORITHM |
| donatien | 0:b802fc31f1db | 61 | # define LWIP_CHKSUM_ALGORITHM 2 |
| donatien | 0:b802fc31f1db | 62 | # endif |
| donatien | 0:b802fc31f1db | 63 | #endif |
| donatien | 0:b802fc31f1db | 64 | /* If none set: */ |
| donatien | 0:b802fc31f1db | 65 | #ifndef LWIP_CHKSUM_ALGORITHM |
| donatien | 0:b802fc31f1db | 66 | # define LWIP_CHKSUM_ALGORITHM 0 |
| donatien | 0:b802fc31f1db | 67 | #endif |
| donatien | 0:b802fc31f1db | 68 | |
| donatien | 0:b802fc31f1db | 69 | #if (LWIP_CHKSUM_ALGORITHM == 1) /* Version #1 */ |
| donatien | 0:b802fc31f1db | 70 | /** |
| donatien | 0:b802fc31f1db | 71 | * lwip checksum |
| donatien | 0:b802fc31f1db | 72 | * |
| donatien | 0:b802fc31f1db | 73 | * @param dataptr points to start of data to be summed at any boundary |
| donatien | 0:b802fc31f1db | 74 | * @param len length of data to be summed |
| donatien | 0:b802fc31f1db | 75 | * @return host order (!) lwip checksum (non-inverted Internet sum) |
| donatien | 0:b802fc31f1db | 76 | * |
| donatien | 0:b802fc31f1db | 77 | * @note accumulator size limits summable length to 64k |
| donatien | 0:b802fc31f1db | 78 | * @note host endianess is irrelevant (p3 RFC1071) |
| donatien | 0:b802fc31f1db | 79 | */ |
| donatien | 0:b802fc31f1db | 80 | static u16_t |
| donatien | 0:b802fc31f1db | 81 | lwip_standard_chksum(void *dataptr, u16_t len) |
| donatien | 0:b802fc31f1db | 82 | { |
| donatien | 0:b802fc31f1db | 83 | u32_t acc; |
| donatien | 0:b802fc31f1db | 84 | u16_t src; |
| donatien | 0:b802fc31f1db | 85 | u8_t *octetptr; |
| donatien | 0:b802fc31f1db | 86 | |
| donatien | 0:b802fc31f1db | 87 | acc = 0; |
| donatien | 0:b802fc31f1db | 88 | /* dataptr may be at odd or even addresses */ |
| donatien | 0:b802fc31f1db | 89 | octetptr = (u8_t*)dataptr; |
| donatien | 0:b802fc31f1db | 90 | while (len > 1) { |
| donatien | 0:b802fc31f1db | 91 | /* declare first octet as most significant |
| donatien | 0:b802fc31f1db | 92 | thus assume network order, ignoring host order */ |
| donatien | 0:b802fc31f1db | 93 | src = (*octetptr) << 8; |
| donatien | 0:b802fc31f1db | 94 | octetptr++; |
| donatien | 0:b802fc31f1db | 95 | /* declare second octet as least significant */ |
| donatien | 0:b802fc31f1db | 96 | src |= (*octetptr); |
| donatien | 0:b802fc31f1db | 97 | octetptr++; |
| donatien | 0:b802fc31f1db | 98 | acc += src; |
| donatien | 0:b802fc31f1db | 99 | len -= 2; |
| donatien | 0:b802fc31f1db | 100 | } |
| donatien | 0:b802fc31f1db | 101 | if (len > 0) { |
| donatien | 0:b802fc31f1db | 102 | /* accumulate remaining octet */ |
| donatien | 0:b802fc31f1db | 103 | src = (*octetptr) << 8; |
| donatien | 0:b802fc31f1db | 104 | acc += src; |
| donatien | 0:b802fc31f1db | 105 | } |
| donatien | 0:b802fc31f1db | 106 | /* add deferred carry bits */ |
| donatien | 0:b802fc31f1db | 107 | acc = (acc >> 16) + (acc & 0x0000ffffUL); |
| donatien | 0:b802fc31f1db | 108 | if ((acc & 0xffff0000UL) != 0) { |
| donatien | 0:b802fc31f1db | 109 | acc = (acc >> 16) + (acc & 0x0000ffffUL); |
| donatien | 0:b802fc31f1db | 110 | } |
| donatien | 0:b802fc31f1db | 111 | /* This maybe a little confusing: reorder sum using htons() |
| donatien | 0:b802fc31f1db | 112 | instead of ntohs() since it has a little less call overhead. |
| donatien | 0:b802fc31f1db | 113 | The caller must invert bits for Internet sum ! */ |
| donatien | 0:b802fc31f1db | 114 | return htons((u16_t)acc); |
| donatien | 0:b802fc31f1db | 115 | } |
| donatien | 0:b802fc31f1db | 116 | #endif |
| donatien | 0:b802fc31f1db | 117 | |
| donatien | 0:b802fc31f1db | 118 | #if (LWIP_CHKSUM_ALGORITHM == 2) /* Alternative version #2 */ |
| donatien | 0:b802fc31f1db | 119 | /* |
| donatien | 0:b802fc31f1db | 120 | * Curt McDowell |
| donatien | 0:b802fc31f1db | 121 | * Broadcom Corp. |
| donatien | 0:b802fc31f1db | 122 | * csm@broadcom.com |
| donatien | 0:b802fc31f1db | 123 | * |
| donatien | 0:b802fc31f1db | 124 | * IP checksum two bytes at a time with support for |
| donatien | 0:b802fc31f1db | 125 | * unaligned buffer. |
| donatien | 0:b802fc31f1db | 126 | * Works for len up to and including 0x20000. |
| donatien | 0:b802fc31f1db | 127 | * by Curt McDowell, Broadcom Corp. 12/08/2005 |
| donatien | 0:b802fc31f1db | 128 | * |
| donatien | 0:b802fc31f1db | 129 | * @param dataptr points to start of data to be summed at any boundary |
| donatien | 0:b802fc31f1db | 130 | * @param len length of data to be summed |
| donatien | 0:b802fc31f1db | 131 | * @return host order (!) lwip checksum (non-inverted Internet sum) |
| donatien | 0:b802fc31f1db | 132 | */ |
| donatien | 0:b802fc31f1db | 133 | |
| donatien | 0:b802fc31f1db | 134 | static u16_t |
| donatien | 0:b802fc31f1db | 135 | lwip_standard_chksum(void *dataptr, int len) |
| donatien | 0:b802fc31f1db | 136 | { |
| donatien | 0:b802fc31f1db | 137 | u8_t *pb = (u8_t *)dataptr; |
| donatien | 0:b802fc31f1db | 138 | u16_t *ps, t = 0; |
| donatien | 0:b802fc31f1db | 139 | u32_t sum = 0; |
| donatien | 0:b802fc31f1db | 140 | int odd = ((mem_ptr_t)pb & 1); |
| donatien | 0:b802fc31f1db | 141 | |
| donatien | 0:b802fc31f1db | 142 | /* Get aligned to u16_t */ |
| donatien | 0:b802fc31f1db | 143 | if (odd && len > 0) { |
| donatien | 0:b802fc31f1db | 144 | ((u8_t *)&t)[1] = *pb++; |
| donatien | 0:b802fc31f1db | 145 | len--; |
| donatien | 0:b802fc31f1db | 146 | } |
| donatien | 0:b802fc31f1db | 147 | |
| donatien | 0:b802fc31f1db | 148 | /* Add the bulk of the data */ |
| donatien | 0:b802fc31f1db | 149 | ps = (u16_t *)(void *)pb; |
| donatien | 0:b802fc31f1db | 150 | while (len > 1) { |
| donatien | 0:b802fc31f1db | 151 | sum += *ps++; |
| donatien | 0:b802fc31f1db | 152 | len -= 2; |
| donatien | 0:b802fc31f1db | 153 | } |
| donatien | 0:b802fc31f1db | 154 | |
| donatien | 0:b802fc31f1db | 155 | /* Consume left-over byte, if any */ |
| donatien | 0:b802fc31f1db | 156 | if (len > 0) { |
| donatien | 0:b802fc31f1db | 157 | ((u8_t *)&t)[0] = *(u8_t *)ps; |
| donatien | 0:b802fc31f1db | 158 | } |
| donatien | 0:b802fc31f1db | 159 | |
| donatien | 0:b802fc31f1db | 160 | /* Add end bytes */ |
| donatien | 0:b802fc31f1db | 161 | sum += t; |
| donatien | 0:b802fc31f1db | 162 | |
| donatien | 0:b802fc31f1db | 163 | /* Fold 32-bit sum to 16 bits |
| donatien | 0:b802fc31f1db | 164 | calling this twice is propably faster than if statements... */ |
| donatien | 0:b802fc31f1db | 165 | sum = FOLD_U32T(sum); |
| donatien | 0:b802fc31f1db | 166 | sum = FOLD_U32T(sum); |
| donatien | 0:b802fc31f1db | 167 | |
| donatien | 0:b802fc31f1db | 168 | /* Swap if alignment was odd */ |
| donatien | 0:b802fc31f1db | 169 | if (odd) { |
| donatien | 0:b802fc31f1db | 170 | sum = SWAP_BYTES_IN_WORD(sum); |
| donatien | 0:b802fc31f1db | 171 | } |
| donatien | 0:b802fc31f1db | 172 | |
| donatien | 0:b802fc31f1db | 173 | return (u16_t)sum; |
| donatien | 0:b802fc31f1db | 174 | } |
| donatien | 0:b802fc31f1db | 175 | #endif |
| donatien | 0:b802fc31f1db | 176 | |
| donatien | 0:b802fc31f1db | 177 | #if (LWIP_CHKSUM_ALGORITHM == 3) /* Alternative version #3 */ |
| donatien | 0:b802fc31f1db | 178 | /** |
| donatien | 0:b802fc31f1db | 179 | * An optimized checksum routine. Basically, it uses loop-unrolling on |
| donatien | 0:b802fc31f1db | 180 | * the checksum loop, treating the head and tail bytes specially, whereas |
| donatien | 0:b802fc31f1db | 181 | * the inner loop acts on 8 bytes at a time. |
| donatien | 0:b802fc31f1db | 182 | * |
| donatien | 0:b802fc31f1db | 183 | * @arg start of buffer to be checksummed. May be an odd byte address. |
| donatien | 0:b802fc31f1db | 184 | * @len number of bytes in the buffer to be checksummed. |
| donatien | 0:b802fc31f1db | 185 | * @return host order (!) lwip checksum (non-inverted Internet sum) |
| donatien | 0:b802fc31f1db | 186 | * |
| donatien | 0:b802fc31f1db | 187 | * by Curt McDowell, Broadcom Corp. December 8th, 2005 |
| donatien | 0:b802fc31f1db | 188 | */ |
| donatien | 0:b802fc31f1db | 189 | |
| donatien | 0:b802fc31f1db | 190 | static u16_t |
| donatien | 0:b802fc31f1db | 191 | lwip_standard_chksum(void *dataptr, int len) |
| donatien | 0:b802fc31f1db | 192 | { |
| donatien | 0:b802fc31f1db | 193 | u8_t *pb = (u8_t *)dataptr; |
| donatien | 0:b802fc31f1db | 194 | u16_t *ps, t = 0; |
| donatien | 0:b802fc31f1db | 195 | u32_t *pl; |
| donatien | 0:b802fc31f1db | 196 | u32_t sum = 0, tmp; |
| donatien | 0:b802fc31f1db | 197 | /* starts at odd byte address? */ |
| donatien | 0:b802fc31f1db | 198 | int odd = ((mem_ptr_t)pb & 1); |
| donatien | 0:b802fc31f1db | 199 | |
| donatien | 0:b802fc31f1db | 200 | if (odd && len > 0) { |
| donatien | 0:b802fc31f1db | 201 | ((u8_t *)&t)[1] = *pb++; |
| donatien | 0:b802fc31f1db | 202 | len--; |
| donatien | 0:b802fc31f1db | 203 | } |
| donatien | 0:b802fc31f1db | 204 | |
| donatien | 0:b802fc31f1db | 205 | ps = (u16_t *)pb; |
| donatien | 0:b802fc31f1db | 206 | |
| donatien | 0:b802fc31f1db | 207 | if (((mem_ptr_t)ps & 3) && len > 1) { |
| donatien | 0:b802fc31f1db | 208 | sum += *ps++; |
| donatien | 0:b802fc31f1db | 209 | len -= 2; |
| donatien | 0:b802fc31f1db | 210 | } |
| donatien | 0:b802fc31f1db | 211 | |
| donatien | 0:b802fc31f1db | 212 | pl = (u32_t *)ps; |
| donatien | 0:b802fc31f1db | 213 | |
| donatien | 0:b802fc31f1db | 214 | while (len > 7) { |
| donatien | 0:b802fc31f1db | 215 | tmp = sum + *pl++; /* ping */ |
| donatien | 0:b802fc31f1db | 216 | if (tmp < sum) { |
| donatien | 0:b802fc31f1db | 217 | tmp++; /* add back carry */ |
| donatien | 0:b802fc31f1db | 218 | } |
| donatien | 0:b802fc31f1db | 219 | |
| donatien | 0:b802fc31f1db | 220 | sum = tmp + *pl++; /* pong */ |
| donatien | 0:b802fc31f1db | 221 | if (sum < tmp) { |
| donatien | 0:b802fc31f1db | 222 | sum++; /* add back carry */ |
| donatien | 0:b802fc31f1db | 223 | } |
| donatien | 0:b802fc31f1db | 224 | |
| donatien | 0:b802fc31f1db | 225 | len -= 8; |
| donatien | 0:b802fc31f1db | 226 | } |
| donatien | 0:b802fc31f1db | 227 | |
| donatien | 0:b802fc31f1db | 228 | /* make room in upper bits */ |
| donatien | 0:b802fc31f1db | 229 | sum = FOLD_U32T(sum); |
| donatien | 0:b802fc31f1db | 230 | |
| donatien | 0:b802fc31f1db | 231 | ps = (u16_t *)pl; |
| donatien | 0:b802fc31f1db | 232 | |
| donatien | 0:b802fc31f1db | 233 | /* 16-bit aligned word remaining? */ |
| donatien | 0:b802fc31f1db | 234 | while (len > 1) { |
| donatien | 0:b802fc31f1db | 235 | sum += *ps++; |
| donatien | 0:b802fc31f1db | 236 | len -= 2; |
| donatien | 0:b802fc31f1db | 237 | } |
| donatien | 0:b802fc31f1db | 238 | |
| donatien | 0:b802fc31f1db | 239 | /* dangling tail byte remaining? */ |
| donatien | 0:b802fc31f1db | 240 | if (len > 0) { /* include odd byte */ |
| donatien | 0:b802fc31f1db | 241 | ((u8_t *)&t)[0] = *(u8_t *)ps; |
| donatien | 0:b802fc31f1db | 242 | } |
| donatien | 0:b802fc31f1db | 243 | |
| donatien | 0:b802fc31f1db | 244 | sum += t; /* add end bytes */ |
| donatien | 0:b802fc31f1db | 245 | |
| donatien | 0:b802fc31f1db | 246 | /* Fold 32-bit sum to 16 bits |
| donatien | 0:b802fc31f1db | 247 | calling this twice is propably faster than if statements... */ |
| donatien | 0:b802fc31f1db | 248 | sum = FOLD_U32T(sum); |
| donatien | 0:b802fc31f1db | 249 | sum = FOLD_U32T(sum); |
| donatien | 0:b802fc31f1db | 250 | |
| donatien | 0:b802fc31f1db | 251 | if (odd) { |
| donatien | 0:b802fc31f1db | 252 | sum = SWAP_BYTES_IN_WORD(sum); |
| donatien | 0:b802fc31f1db | 253 | } |
| donatien | 0:b802fc31f1db | 254 | |
| donatien | 0:b802fc31f1db | 255 | return (u16_t)sum; |
| donatien | 0:b802fc31f1db | 256 | } |
| donatien | 0:b802fc31f1db | 257 | #endif |
| donatien | 0:b802fc31f1db | 258 | |
| donatien | 0:b802fc31f1db | 259 | /* inet_chksum_pseudo: |
| donatien | 0:b802fc31f1db | 260 | * |
| donatien | 0:b802fc31f1db | 261 | * Calculates the pseudo Internet checksum used by TCP and UDP for a pbuf chain. |
| donatien | 0:b802fc31f1db | 262 | * IP addresses are expected to be in network byte order. |
| donatien | 0:b802fc31f1db | 263 | * |
| donatien | 0:b802fc31f1db | 264 | * @param p chain of pbufs over that a checksum should be calculated (ip data part) |
| donatien | 0:b802fc31f1db | 265 | * @param src source ip address (used for checksum of pseudo header) |
| donatien | 0:b802fc31f1db | 266 | * @param dst destination ip address (used for checksum of pseudo header) |
| donatien | 0:b802fc31f1db | 267 | * @param proto ip protocol (used for checksum of pseudo header) |
| donatien | 0:b802fc31f1db | 268 | * @param proto_len length of the ip data part (used for checksum of pseudo header) |
| donatien | 0:b802fc31f1db | 269 | * @return checksum (as u16_t) to be saved directly in the protocol header |
| donatien | 0:b802fc31f1db | 270 | */ |
| donatien | 0:b802fc31f1db | 271 | u16_t |
| donatien | 0:b802fc31f1db | 272 | inet_chksum_pseudo(struct pbuf *p, |
| donatien | 0:b802fc31f1db | 273 | ip_addr_t *src, ip_addr_t *dest, |
| donatien | 0:b802fc31f1db | 274 | u8_t proto, u16_t proto_len) |
| donatien | 0:b802fc31f1db | 275 | { |
| donatien | 0:b802fc31f1db | 276 | u32_t acc; |
| donatien | 0:b802fc31f1db | 277 | u32_t addr; |
| donatien | 0:b802fc31f1db | 278 | struct pbuf *q; |
| donatien | 0:b802fc31f1db | 279 | u8_t swapped; |
| donatien | 0:b802fc31f1db | 280 | |
| donatien | 0:b802fc31f1db | 281 | acc = 0; |
| donatien | 0:b802fc31f1db | 282 | swapped = 0; |
| donatien | 0:b802fc31f1db | 283 | /* iterate through all pbuf in chain */ |
| donatien | 0:b802fc31f1db | 284 | for(q = p; q != NULL; q = q->next) { |
| donatien | 0:b802fc31f1db | 285 | LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): checksumming pbuf %p (has next %p) \n", |
| donatien | 0:b802fc31f1db | 286 | (void *)q, (void *)q->next)); |
| donatien | 0:b802fc31f1db | 287 | acc += LWIP_CHKSUM(q->payload, q->len); |
| donatien | 0:b802fc31f1db | 288 | /*LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): unwrapped lwip_chksum()=%"X32_F" \n", acc));*/ |
| donatien | 0:b802fc31f1db | 289 | /* just executing this next line is probably faster that the if statement needed |
| donatien | 0:b802fc31f1db | 290 | to check whether we really need to execute it, and does no harm */ |
| donatien | 0:b802fc31f1db | 291 | acc = FOLD_U32T(acc); |
| donatien | 0:b802fc31f1db | 292 | if (q->len % 2 != 0) { |
| donatien | 0:b802fc31f1db | 293 | swapped = 1 - swapped; |
| donatien | 0:b802fc31f1db | 294 | acc = SWAP_BYTES_IN_WORD(acc); |
| donatien | 0:b802fc31f1db | 295 | } |
| donatien | 0:b802fc31f1db | 296 | /*LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): wrapped lwip_chksum()=%"X32_F" \n", acc));*/ |
| donatien | 0:b802fc31f1db | 297 | } |
| donatien | 0:b802fc31f1db | 298 | |
| donatien | 0:b802fc31f1db | 299 | if (swapped) { |
| donatien | 0:b802fc31f1db | 300 | acc = SWAP_BYTES_IN_WORD(acc); |
| donatien | 0:b802fc31f1db | 301 | } |
| donatien | 0:b802fc31f1db | 302 | addr = ip4_addr_get_u32(src); |
| donatien | 0:b802fc31f1db | 303 | acc += (addr & 0xffffUL); |
| donatien | 0:b802fc31f1db | 304 | acc += ((addr >> 16) & 0xffffUL); |
| donatien | 0:b802fc31f1db | 305 | addr = ip4_addr_get_u32(dest); |
| donatien | 0:b802fc31f1db | 306 | acc += (addr & 0xffffUL); |
| donatien | 0:b802fc31f1db | 307 | acc += ((addr >> 16) & 0xffffUL); |
| donatien | 0:b802fc31f1db | 308 | acc += (u32_t)htons((u16_t)proto); |
| donatien | 0:b802fc31f1db | 309 | acc += (u32_t)htons(proto_len); |
| donatien | 0:b802fc31f1db | 310 | |
| donatien | 0:b802fc31f1db | 311 | /* Fold 32-bit sum to 16 bits |
| donatien | 0:b802fc31f1db | 312 | calling this twice is propably faster than if statements... */ |
| donatien | 0:b802fc31f1db | 313 | acc = FOLD_U32T(acc); |
| donatien | 0:b802fc31f1db | 314 | acc = FOLD_U32T(acc); |
| donatien | 0:b802fc31f1db | 315 | LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): pbuf chain lwip_chksum()=%"X32_F"\n", acc)); |
| donatien | 0:b802fc31f1db | 316 | return (u16_t)~(acc & 0xffffUL); |
| donatien | 0:b802fc31f1db | 317 | } |
| donatien | 0:b802fc31f1db | 318 | |
| donatien | 0:b802fc31f1db | 319 | /* inet_chksum_pseudo: |
| donatien | 0:b802fc31f1db | 320 | * |
| donatien | 0:b802fc31f1db | 321 | * Calculates the pseudo Internet checksum used by TCP and UDP for a pbuf chain. |
| donatien | 0:b802fc31f1db | 322 | * IP addresses are expected to be in network byte order. |
| donatien | 0:b802fc31f1db | 323 | * |
| donatien | 0:b802fc31f1db | 324 | * @param p chain of pbufs over that a checksum should be calculated (ip data part) |
| donatien | 0:b802fc31f1db | 325 | * @param src source ip address (used for checksum of pseudo header) |
| donatien | 0:b802fc31f1db | 326 | * @param dst destination ip address (used for checksum of pseudo header) |
| donatien | 0:b802fc31f1db | 327 | * @param proto ip protocol (used for checksum of pseudo header) |
| donatien | 0:b802fc31f1db | 328 | * @param proto_len length of the ip data part (used for checksum of pseudo header) |
| donatien | 0:b802fc31f1db | 329 | * @return checksum (as u16_t) to be saved directly in the protocol header |
| donatien | 0:b802fc31f1db | 330 | */ |
| donatien | 0:b802fc31f1db | 331 | u16_t |
| donatien | 0:b802fc31f1db | 332 | inet_chksum_pseudo_partial(struct pbuf *p, |
| donatien | 0:b802fc31f1db | 333 | ip_addr_t *src, ip_addr_t *dest, |
| donatien | 0:b802fc31f1db | 334 | u8_t proto, u16_t proto_len, u16_t chksum_len) |
| donatien | 0:b802fc31f1db | 335 | { |
| donatien | 0:b802fc31f1db | 336 | u32_t acc; |
| donatien | 0:b802fc31f1db | 337 | u32_t addr; |
| donatien | 0:b802fc31f1db | 338 | struct pbuf *q; |
| donatien | 0:b802fc31f1db | 339 | u8_t swapped; |
| donatien | 0:b802fc31f1db | 340 | u16_t chklen; |
| donatien | 0:b802fc31f1db | 341 | |
| donatien | 0:b802fc31f1db | 342 | acc = 0; |
| donatien | 0:b802fc31f1db | 343 | swapped = 0; |
| donatien | 0:b802fc31f1db | 344 | /* iterate through all pbuf in chain */ |
| donatien | 0:b802fc31f1db | 345 | for(q = p; (q != NULL) && (chksum_len > 0); q = q->next) { |
| donatien | 0:b802fc31f1db | 346 | LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): checksumming pbuf %p (has next %p) \n", |
| donatien | 0:b802fc31f1db | 347 | (void *)q, (void *)q->next)); |
| donatien | 0:b802fc31f1db | 348 | chklen = q->len; |
| donatien | 0:b802fc31f1db | 349 | if (chklen > chksum_len) { |
| donatien | 0:b802fc31f1db | 350 | chklen = chksum_len; |
| donatien | 0:b802fc31f1db | 351 | } |
| donatien | 0:b802fc31f1db | 352 | acc += LWIP_CHKSUM(q->payload, chklen); |
| donatien | 0:b802fc31f1db | 353 | chksum_len -= chklen; |
| donatien | 0:b802fc31f1db | 354 | LWIP_ASSERT("delete me", chksum_len < 0x7fff); |
| donatien | 0:b802fc31f1db | 355 | /*LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): unwrapped lwip_chksum()=%"X32_F" \n", acc));*/ |
| donatien | 0:b802fc31f1db | 356 | /* fold the upper bit down */ |
| donatien | 0:b802fc31f1db | 357 | acc = FOLD_U32T(acc); |
| donatien | 0:b802fc31f1db | 358 | if (q->len % 2 != 0) { |
| donatien | 0:b802fc31f1db | 359 | swapped = 1 - swapped; |
| donatien | 0:b802fc31f1db | 360 | acc = SWAP_BYTES_IN_WORD(acc); |
| donatien | 0:b802fc31f1db | 361 | } |
| donatien | 0:b802fc31f1db | 362 | /*LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): wrapped lwip_chksum()=%"X32_F" \n", acc));*/ |
| donatien | 0:b802fc31f1db | 363 | } |
| donatien | 0:b802fc31f1db | 364 | |
| donatien | 0:b802fc31f1db | 365 | if (swapped) { |
| donatien | 0:b802fc31f1db | 366 | acc = SWAP_BYTES_IN_WORD(acc); |
| donatien | 0:b802fc31f1db | 367 | } |
| donatien | 0:b802fc31f1db | 368 | addr = ip4_addr_get_u32(src); |
| donatien | 0:b802fc31f1db | 369 | acc += (addr & 0xffffUL); |
| donatien | 0:b802fc31f1db | 370 | acc += ((addr >> 16) & 0xffffUL); |
| donatien | 0:b802fc31f1db | 371 | addr = ip4_addr_get_u32(dest); |
| donatien | 0:b802fc31f1db | 372 | acc += (addr & 0xffffUL); |
| donatien | 0:b802fc31f1db | 373 | acc += ((addr >> 16) & 0xffffUL); |
| donatien | 0:b802fc31f1db | 374 | acc += (u32_t)htons((u16_t)proto); |
| donatien | 0:b802fc31f1db | 375 | acc += (u32_t)htons(proto_len); |
| donatien | 0:b802fc31f1db | 376 | |
| donatien | 0:b802fc31f1db | 377 | /* Fold 32-bit sum to 16 bits |
| donatien | 0:b802fc31f1db | 378 | calling this twice is propably faster than if statements... */ |
| donatien | 0:b802fc31f1db | 379 | acc = FOLD_U32T(acc); |
| donatien | 0:b802fc31f1db | 380 | acc = FOLD_U32T(acc); |
| donatien | 0:b802fc31f1db | 381 | LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): pbuf chain lwip_chksum()=%"X32_F"\n", acc)); |
| donatien | 0:b802fc31f1db | 382 | return (u16_t)~(acc & 0xffffUL); |
| donatien | 0:b802fc31f1db | 383 | } |
| donatien | 0:b802fc31f1db | 384 | |
| donatien | 0:b802fc31f1db | 385 | /* inet_chksum: |
| donatien | 0:b802fc31f1db | 386 | * |
| donatien | 0:b802fc31f1db | 387 | * Calculates the Internet checksum over a portion of memory. Used primarily for IP |
| donatien | 0:b802fc31f1db | 388 | * and ICMP. |
| donatien | 0:b802fc31f1db | 389 | * |
| donatien | 0:b802fc31f1db | 390 | * @param dataptr start of the buffer to calculate the checksum (no alignment needed) |
| donatien | 0:b802fc31f1db | 391 | * @param len length of the buffer to calculate the checksum |
| donatien | 0:b802fc31f1db | 392 | * @return checksum (as u16_t) to be saved directly in the protocol header |
| donatien | 0:b802fc31f1db | 393 | */ |
| donatien | 0:b802fc31f1db | 394 | |
| donatien | 0:b802fc31f1db | 395 | u16_t |
| donatien | 0:b802fc31f1db | 396 | inet_chksum(void *dataptr, u16_t len) |
| donatien | 0:b802fc31f1db | 397 | { |
| donatien | 0:b802fc31f1db | 398 | return ~LWIP_CHKSUM(dataptr, len); |
| donatien | 0:b802fc31f1db | 399 | } |
| donatien | 0:b802fc31f1db | 400 | |
| donatien | 0:b802fc31f1db | 401 | /** |
| donatien | 0:b802fc31f1db | 402 | * Calculate a checksum over a chain of pbufs (without pseudo-header, much like |
| donatien | 0:b802fc31f1db | 403 | * inet_chksum only pbufs are used). |
| donatien | 0:b802fc31f1db | 404 | * |
| donatien | 0:b802fc31f1db | 405 | * @param p pbuf chain over that the checksum should be calculated |
| donatien | 0:b802fc31f1db | 406 | * @return checksum (as u16_t) to be saved directly in the protocol header |
| donatien | 0:b802fc31f1db | 407 | */ |
| donatien | 0:b802fc31f1db | 408 | u16_t |
| donatien | 0:b802fc31f1db | 409 | inet_chksum_pbuf(struct pbuf *p) |
| donatien | 0:b802fc31f1db | 410 | { |
| donatien | 0:b802fc31f1db | 411 | u32_t acc; |
| donatien | 0:b802fc31f1db | 412 | struct pbuf *q; |
| donatien | 0:b802fc31f1db | 413 | u8_t swapped; |
| donatien | 0:b802fc31f1db | 414 | |
| donatien | 0:b802fc31f1db | 415 | acc = 0; |
| donatien | 0:b802fc31f1db | 416 | swapped = 0; |
| donatien | 0:b802fc31f1db | 417 | for(q = p; q != NULL; q = q->next) { |
| donatien | 0:b802fc31f1db | 418 | acc += LWIP_CHKSUM(q->payload, q->len); |
| donatien | 0:b802fc31f1db | 419 | acc = FOLD_U32T(acc); |
| donatien | 0:b802fc31f1db | 420 | if (q->len % 2 != 0) { |
| donatien | 0:b802fc31f1db | 421 | swapped = 1 - swapped; |
| donatien | 0:b802fc31f1db | 422 | acc = SWAP_BYTES_IN_WORD(acc); |
| donatien | 0:b802fc31f1db | 423 | } |
| donatien | 0:b802fc31f1db | 424 | } |
| donatien | 0:b802fc31f1db | 425 | |
| donatien | 0:b802fc31f1db | 426 | if (swapped) { |
| donatien | 0:b802fc31f1db | 427 | acc = SWAP_BYTES_IN_WORD(acc); |
| donatien | 0:b802fc31f1db | 428 | } |
| donatien | 0:b802fc31f1db | 429 | return (u16_t)~(acc & 0xffffUL); |
| donatien | 0:b802fc31f1db | 430 | } |
| donatien | 0:b802fc31f1db | 431 | |
| donatien | 0:b802fc31f1db | 432 | /* These are some implementations for LWIP_CHKSUM_COPY, which copies data |
| donatien | 0:b802fc31f1db | 433 | * like MEMCPY but generates a checksum at the same time. Since this is a |
| donatien | 0:b802fc31f1db | 434 | * performance-sensitive function, you might want to create your own version |
| donatien | 0:b802fc31f1db | 435 | * in assembly targeted at your hardware by defining it in lwipopts.h: |
| donatien | 0:b802fc31f1db | 436 | * #define LWIP_CHKSUM_COPY(dst, src, len) your_chksum_copy(dst, src, len) |
| donatien | 0:b802fc31f1db | 437 | */ |
| donatien | 0:b802fc31f1db | 438 | |
| donatien | 0:b802fc31f1db | 439 | #if (LWIP_CHKSUM_COPY_ALGORITHM == 1) /* Version #1 */ |
| donatien | 0:b802fc31f1db | 440 | /** Safe but slow: first call MEMCPY, then call LWIP_CHKSUM. |
| donatien | 0:b802fc31f1db | 441 | * For architectures with big caches, data might still be in cache when |
| donatien | 0:b802fc31f1db | 442 | * generating the checksum after copying. |
| donatien | 0:b802fc31f1db | 443 | */ |
| donatien | 0:b802fc31f1db | 444 | u16_t |
| donatien | 0:b802fc31f1db | 445 | lwip_chksum_copy(void *dst, const void *src, u16_t len) |
| donatien | 0:b802fc31f1db | 446 | { |
| donatien | 0:b802fc31f1db | 447 | MEMCPY(dst, src, len); |
| donatien | 0:b802fc31f1db | 448 | return LWIP_CHKSUM(dst, len); |
| donatien | 0:b802fc31f1db | 449 | } |
| donatien | 0:b802fc31f1db | 450 | #endif /* (LWIP_CHKSUM_COPY_ALGORITHM == 1) */ |