Darran Shepherd
/
Bonjour
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lwip/core/ipv4/inet_chksum.c@1:4218cacaf696, 2010-06-18 (annotated)
- Committer:
- darran
- Date:
- Fri Jun 18 15:54:21 2010 +0000
- Revision:
- 1:4218cacaf696
- Parent:
- 0:55a05330f8cc
Who changed what in which revision?
| User | Revision | Line number | New contents of line |
|---|---|---|---|
| darran | 0:55a05330f8cc | 1 | /** |
| darran | 0:55a05330f8cc | 2 | * @file |
| darran | 0:55a05330f8cc | 3 | * Incluse internet checksum functions. |
| darran | 0:55a05330f8cc | 4 | * |
| darran | 0:55a05330f8cc | 5 | */ |
| darran | 0:55a05330f8cc | 6 | |
| darran | 0:55a05330f8cc | 7 | /* |
| darran | 0:55a05330f8cc | 8 | * Copyright (c) 2001-2004 Swedish Institute of Computer Science. |
| darran | 0:55a05330f8cc | 9 | * All rights reserved. |
| darran | 0:55a05330f8cc | 10 | * |
| darran | 0:55a05330f8cc | 11 | * Redistribution and use in source and binary forms, with or without modification, |
| darran | 0:55a05330f8cc | 12 | * are permitted provided that the following conditions are met: |
| darran | 0:55a05330f8cc | 13 | * |
| darran | 0:55a05330f8cc | 14 | * 1. Redistributions of source code must retain the above copyright notice, |
| darran | 0:55a05330f8cc | 15 | * this list of conditions and the following disclaimer. |
| darran | 0:55a05330f8cc | 16 | * 2. Redistributions in binary form must reproduce the above copyright notice, |
| darran | 0:55a05330f8cc | 17 | * this list of conditions and the following disclaimer in the documentation |
| darran | 0:55a05330f8cc | 18 | * and/or other materials provided with the distribution. |
| darran | 0:55a05330f8cc | 19 | * 3. The name of the author may not be used to endorse or promote products |
| darran | 0:55a05330f8cc | 20 | * derived from this software without specific prior written permission. |
| darran | 0:55a05330f8cc | 21 | * |
| darran | 0:55a05330f8cc | 22 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED |
| darran | 0:55a05330f8cc | 23 | * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF |
| darran | 0:55a05330f8cc | 24 | * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT |
| darran | 0:55a05330f8cc | 25 | * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, |
| darran | 0:55a05330f8cc | 26 | * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT |
| darran | 0:55a05330f8cc | 27 | * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| darran | 0:55a05330f8cc | 28 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| darran | 0:55a05330f8cc | 29 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING |
| darran | 0:55a05330f8cc | 30 | * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY |
| darran | 0:55a05330f8cc | 31 | * OF SUCH DAMAGE. |
| darran | 0:55a05330f8cc | 32 | * |
| darran | 0:55a05330f8cc | 33 | * This file is part of the lwIP TCP/IP stack. |
| darran | 0:55a05330f8cc | 34 | * |
| darran | 0:55a05330f8cc | 35 | * Author: Adam Dunkels <adam@sics.se> |
| darran | 0:55a05330f8cc | 36 | * |
| darran | 0:55a05330f8cc | 37 | */ |
| darran | 0:55a05330f8cc | 38 | |
| darran | 0:55a05330f8cc | 39 | #include "lwip/opt.h" |
| darran | 0:55a05330f8cc | 40 | |
| darran | 0:55a05330f8cc | 41 | #include "lwip/inet_chksum.h" |
| darran | 0:55a05330f8cc | 42 | #include "lwip/def.h" |
| darran | 0:55a05330f8cc | 43 | |
| darran | 0:55a05330f8cc | 44 | #include <stddef.h> |
| darran | 0:55a05330f8cc | 45 | #include <string.h> |
| darran | 0:55a05330f8cc | 46 | |
| darran | 0:55a05330f8cc | 47 | /* These are some reference implementations of the checksum algorithm, with the |
| darran | 0:55a05330f8cc | 48 | * aim of being simple, correct and fully portable. Checksumming is the |
| darran | 0:55a05330f8cc | 49 | * first thing you would want to optimize for your platform. If you create |
| darran | 0:55a05330f8cc | 50 | * your own version, link it in and in your cc.h put: |
| darran | 0:55a05330f8cc | 51 | * |
| darran | 0:55a05330f8cc | 52 | * #define LWIP_CHKSUM <your_checksum_routine> |
| darran | 0:55a05330f8cc | 53 | * |
| darran | 0:55a05330f8cc | 54 | * Or you can select from the implementations below by defining |
| darran | 0:55a05330f8cc | 55 | * LWIP_CHKSUM_ALGORITHM to 1, 2 or 3. |
| darran | 0:55a05330f8cc | 56 | */ |
| darran | 0:55a05330f8cc | 57 | |
| darran | 0:55a05330f8cc | 58 | #ifndef LWIP_CHKSUM |
| darran | 0:55a05330f8cc | 59 | # define LWIP_CHKSUM lwip_standard_chksum |
| darran | 0:55a05330f8cc | 60 | # ifndef LWIP_CHKSUM_ALGORITHM |
| darran | 0:55a05330f8cc | 61 | # define LWIP_CHKSUM_ALGORITHM 2 |
| darran | 0:55a05330f8cc | 62 | # endif |
| darran | 0:55a05330f8cc | 63 | #endif |
| darran | 0:55a05330f8cc | 64 | /* If none set: */ |
| darran | 0:55a05330f8cc | 65 | #ifndef LWIP_CHKSUM_ALGORITHM |
| darran | 0:55a05330f8cc | 66 | # define LWIP_CHKSUM_ALGORITHM 0 |
| darran | 0:55a05330f8cc | 67 | #endif |
| darran | 0:55a05330f8cc | 68 | |
| darran | 0:55a05330f8cc | 69 | #if (LWIP_CHKSUM_ALGORITHM == 1) /* Version #1 */ |
| darran | 0:55a05330f8cc | 70 | /** |
| darran | 0:55a05330f8cc | 71 | * lwip checksum |
| darran | 0:55a05330f8cc | 72 | * |
| darran | 0:55a05330f8cc | 73 | * @param dataptr points to start of data to be summed at any boundary |
| darran | 0:55a05330f8cc | 74 | * @param len length of data to be summed |
| darran | 0:55a05330f8cc | 75 | * @return host order (!) lwip checksum (non-inverted Internet sum) |
| darran | 0:55a05330f8cc | 76 | * |
| darran | 0:55a05330f8cc | 77 | * @note accumulator size limits summable length to 64k |
| darran | 0:55a05330f8cc | 78 | * @note host endianess is irrelevant (p3 RFC1071) |
| darran | 0:55a05330f8cc | 79 | */ |
| darran | 0:55a05330f8cc | 80 | static u16_t |
| darran | 0:55a05330f8cc | 81 | lwip_standard_chksum(void *dataptr, u16_t len) |
| darran | 0:55a05330f8cc | 82 | { |
| darran | 0:55a05330f8cc | 83 | u32_t acc; |
| darran | 0:55a05330f8cc | 84 | u16_t src; |
| darran | 0:55a05330f8cc | 85 | u8_t *octetptr; |
| darran | 0:55a05330f8cc | 86 | |
| darran | 0:55a05330f8cc | 87 | acc = 0; |
| darran | 0:55a05330f8cc | 88 | /* dataptr may be at odd or even addresses */ |
| darran | 0:55a05330f8cc | 89 | octetptr = (u8_t*)dataptr; |
| darran | 0:55a05330f8cc | 90 | while (len > 1) { |
| darran | 0:55a05330f8cc | 91 | /* declare first octet as most significant |
| darran | 0:55a05330f8cc | 92 | thus assume network order, ignoring host order */ |
| darran | 0:55a05330f8cc | 93 | src = (*octetptr) << 8; |
| darran | 0:55a05330f8cc | 94 | octetptr++; |
| darran | 0:55a05330f8cc | 95 | /* declare second octet as least significant */ |
| darran | 0:55a05330f8cc | 96 | src |= (*octetptr); |
| darran | 0:55a05330f8cc | 97 | octetptr++; |
| darran | 0:55a05330f8cc | 98 | acc += src; |
| darran | 0:55a05330f8cc | 99 | len -= 2; |
| darran | 0:55a05330f8cc | 100 | } |
| darran | 0:55a05330f8cc | 101 | if (len > 0) { |
| darran | 0:55a05330f8cc | 102 | /* accumulate remaining octet */ |
| darran | 0:55a05330f8cc | 103 | src = (*octetptr) << 8; |
| darran | 0:55a05330f8cc | 104 | acc += src; |
| darran | 0:55a05330f8cc | 105 | } |
| darran | 0:55a05330f8cc | 106 | /* add deferred carry bits */ |
| darran | 0:55a05330f8cc | 107 | acc = (acc >> 16) + (acc & 0x0000ffffUL); |
| darran | 0:55a05330f8cc | 108 | if ((acc & 0xffff0000UL) != 0) { |
| darran | 0:55a05330f8cc | 109 | acc = (acc >> 16) + (acc & 0x0000ffffUL); |
| darran | 0:55a05330f8cc | 110 | } |
| darran | 0:55a05330f8cc | 111 | /* This maybe a little confusing: reorder sum using htons() |
| darran | 0:55a05330f8cc | 112 | instead of ntohs() since it has a little less call overhead. |
| darran | 0:55a05330f8cc | 113 | The caller must invert bits for Internet sum ! */ |
| darran | 0:55a05330f8cc | 114 | return htons((u16_t)acc); |
| darran | 0:55a05330f8cc | 115 | } |
| darran | 0:55a05330f8cc | 116 | #endif |
| darran | 0:55a05330f8cc | 117 | |
| darran | 0:55a05330f8cc | 118 | #if (LWIP_CHKSUM_ALGORITHM == 2) /* Alternative version #2 */ |
| darran | 0:55a05330f8cc | 119 | /* |
| darran | 0:55a05330f8cc | 120 | * Curt McDowell |
| darran | 0:55a05330f8cc | 121 | * Broadcom Corp. |
| darran | 0:55a05330f8cc | 122 | * csm@broadcom.com |
| darran | 0:55a05330f8cc | 123 | * |
| darran | 0:55a05330f8cc | 124 | * IP checksum two bytes at a time with support for |
| darran | 0:55a05330f8cc | 125 | * unaligned buffer. |
| darran | 0:55a05330f8cc | 126 | * Works for len up to and including 0x20000. |
| darran | 0:55a05330f8cc | 127 | * by Curt McDowell, Broadcom Corp. 12/08/2005 |
| darran | 0:55a05330f8cc | 128 | * |
| darran | 0:55a05330f8cc | 129 | * @param dataptr points to start of data to be summed at any boundary |
| darran | 0:55a05330f8cc | 130 | * @param len length of data to be summed |
| darran | 0:55a05330f8cc | 131 | * @return host order (!) lwip checksum (non-inverted Internet sum) |
| darran | 0:55a05330f8cc | 132 | */ |
| darran | 0:55a05330f8cc | 133 | |
| darran | 0:55a05330f8cc | 134 | static u16_t |
| darran | 0:55a05330f8cc | 135 | lwip_standard_chksum(void *dataptr, int len) |
| darran | 0:55a05330f8cc | 136 | { |
| darran | 0:55a05330f8cc | 137 | u8_t *pb = (u8_t *)dataptr; |
| darran | 0:55a05330f8cc | 138 | u16_t *ps, t = 0; |
| darran | 0:55a05330f8cc | 139 | u32_t sum = 0; |
| darran | 0:55a05330f8cc | 140 | int odd = ((mem_ptr_t)pb & 1); |
| darran | 0:55a05330f8cc | 141 | |
| darran | 0:55a05330f8cc | 142 | /* Get aligned to u16_t */ |
| darran | 0:55a05330f8cc | 143 | if (odd && len > 0) { |
| darran | 0:55a05330f8cc | 144 | ((u8_t *)&t)[1] = *pb++; |
| darran | 0:55a05330f8cc | 145 | len--; |
| darran | 0:55a05330f8cc | 146 | } |
| darran | 0:55a05330f8cc | 147 | |
| darran | 0:55a05330f8cc | 148 | /* Add the bulk of the data */ |
| darran | 0:55a05330f8cc | 149 | ps = (u16_t *)(void *)pb; |
| darran | 0:55a05330f8cc | 150 | while (len > 1) { |
| darran | 0:55a05330f8cc | 151 | sum += *ps++; |
| darran | 0:55a05330f8cc | 152 | len -= 2; |
| darran | 0:55a05330f8cc | 153 | } |
| darran | 0:55a05330f8cc | 154 | |
| darran | 0:55a05330f8cc | 155 | /* Consume left-over byte, if any */ |
| darran | 0:55a05330f8cc | 156 | if (len > 0) { |
| darran | 0:55a05330f8cc | 157 | ((u8_t *)&t)[0] = *(u8_t *)ps; |
| darran | 0:55a05330f8cc | 158 | } |
| darran | 0:55a05330f8cc | 159 | |
| darran | 0:55a05330f8cc | 160 | /* Add end bytes */ |
| darran | 0:55a05330f8cc | 161 | sum += t; |
| darran | 0:55a05330f8cc | 162 | |
| darran | 0:55a05330f8cc | 163 | /* Fold 32-bit sum to 16 bits |
| darran | 0:55a05330f8cc | 164 | calling this twice is propably faster than if statements... */ |
| darran | 0:55a05330f8cc | 165 | sum = FOLD_U32T(sum); |
| darran | 0:55a05330f8cc | 166 | sum = FOLD_U32T(sum); |
| darran | 0:55a05330f8cc | 167 | |
| darran | 0:55a05330f8cc | 168 | /* Swap if alignment was odd */ |
| darran | 0:55a05330f8cc | 169 | if (odd) { |
| darran | 0:55a05330f8cc | 170 | sum = SWAP_BYTES_IN_WORD(sum); |
| darran | 0:55a05330f8cc | 171 | } |
| darran | 0:55a05330f8cc | 172 | |
| darran | 0:55a05330f8cc | 173 | return (u16_t)sum; |
| darran | 0:55a05330f8cc | 174 | } |
| darran | 0:55a05330f8cc | 175 | #endif |
| darran | 0:55a05330f8cc | 176 | |
| darran | 0:55a05330f8cc | 177 | #if (LWIP_CHKSUM_ALGORITHM == 3) /* Alternative version #3 */ |
| darran | 0:55a05330f8cc | 178 | /** |
| darran | 0:55a05330f8cc | 179 | * An optimized checksum routine. Basically, it uses loop-unrolling on |
| darran | 0:55a05330f8cc | 180 | * the checksum loop, treating the head and tail bytes specially, whereas |
| darran | 0:55a05330f8cc | 181 | * the inner loop acts on 8 bytes at a time. |
| darran | 0:55a05330f8cc | 182 | * |
| darran | 0:55a05330f8cc | 183 | * @arg start of buffer to be checksummed. May be an odd byte address. |
| darran | 0:55a05330f8cc | 184 | * @len number of bytes in the buffer to be checksummed. |
| darran | 0:55a05330f8cc | 185 | * @return host order (!) lwip checksum (non-inverted Internet sum) |
| darran | 0:55a05330f8cc | 186 | * |
| darran | 0:55a05330f8cc | 187 | * by Curt McDowell, Broadcom Corp. December 8th, 2005 |
| darran | 0:55a05330f8cc | 188 | */ |
| darran | 0:55a05330f8cc | 189 | |
| darran | 0:55a05330f8cc | 190 | static u16_t |
| darran | 0:55a05330f8cc | 191 | lwip_standard_chksum(void *dataptr, int len) |
| darran | 0:55a05330f8cc | 192 | { |
| darran | 0:55a05330f8cc | 193 | u8_t *pb = (u8_t *)dataptr; |
| darran | 0:55a05330f8cc | 194 | u16_t *ps, t = 0; |
| darran | 0:55a05330f8cc | 195 | u32_t *pl; |
| darran | 0:55a05330f8cc | 196 | u32_t sum = 0, tmp; |
| darran | 0:55a05330f8cc | 197 | /* starts at odd byte address? */ |
| darran | 0:55a05330f8cc | 198 | int odd = ((mem_ptr_t)pb & 1); |
| darran | 0:55a05330f8cc | 199 | |
| darran | 0:55a05330f8cc | 200 | if (odd && len > 0) { |
| darran | 0:55a05330f8cc | 201 | ((u8_t *)&t)[1] = *pb++; |
| darran | 0:55a05330f8cc | 202 | len--; |
| darran | 0:55a05330f8cc | 203 | } |
| darran | 0:55a05330f8cc | 204 | |
| darran | 0:55a05330f8cc | 205 | ps = (u16_t *)pb; |
| darran | 0:55a05330f8cc | 206 | |
| darran | 0:55a05330f8cc | 207 | if (((mem_ptr_t)ps & 3) && len > 1) { |
| darran | 0:55a05330f8cc | 208 | sum += *ps++; |
| darran | 0:55a05330f8cc | 209 | len -= 2; |
| darran | 0:55a05330f8cc | 210 | } |
| darran | 0:55a05330f8cc | 211 | |
| darran | 0:55a05330f8cc | 212 | pl = (u32_t *)ps; |
| darran | 0:55a05330f8cc | 213 | |
| darran | 0:55a05330f8cc | 214 | while (len > 7) { |
| darran | 0:55a05330f8cc | 215 | tmp = sum + *pl++; /* ping */ |
| darran | 0:55a05330f8cc | 216 | if (tmp < sum) { |
| darran | 0:55a05330f8cc | 217 | tmp++; /* add back carry */ |
| darran | 0:55a05330f8cc | 218 | } |
| darran | 0:55a05330f8cc | 219 | |
| darran | 0:55a05330f8cc | 220 | sum = tmp + *pl++; /* pong */ |
| darran | 0:55a05330f8cc | 221 | if (sum < tmp) { |
| darran | 0:55a05330f8cc | 222 | sum++; /* add back carry */ |
| darran | 0:55a05330f8cc | 223 | } |
| darran | 0:55a05330f8cc | 224 | |
| darran | 0:55a05330f8cc | 225 | len -= 8; |
| darran | 0:55a05330f8cc | 226 | } |
| darran | 0:55a05330f8cc | 227 | |
| darran | 0:55a05330f8cc | 228 | /* make room in upper bits */ |
| darran | 0:55a05330f8cc | 229 | sum = FOLD_U32T(sum); |
| darran | 0:55a05330f8cc | 230 | |
| darran | 0:55a05330f8cc | 231 | ps = (u16_t *)pl; |
| darran | 0:55a05330f8cc | 232 | |
| darran | 0:55a05330f8cc | 233 | /* 16-bit aligned word remaining? */ |
| darran | 0:55a05330f8cc | 234 | while (len > 1) { |
| darran | 0:55a05330f8cc | 235 | sum += *ps++; |
| darran | 0:55a05330f8cc | 236 | len -= 2; |
| darran | 0:55a05330f8cc | 237 | } |
| darran | 0:55a05330f8cc | 238 | |
| darran | 0:55a05330f8cc | 239 | /* dangling tail byte remaining? */ |
| darran | 0:55a05330f8cc | 240 | if (len > 0) { /* include odd byte */ |
| darran | 0:55a05330f8cc | 241 | ((u8_t *)&t)[0] = *(u8_t *)ps; |
| darran | 0:55a05330f8cc | 242 | } |
| darran | 0:55a05330f8cc | 243 | |
| darran | 0:55a05330f8cc | 244 | sum += t; /* add end bytes */ |
| darran | 0:55a05330f8cc | 245 | |
| darran | 0:55a05330f8cc | 246 | /* Fold 32-bit sum to 16 bits |
| darran | 0:55a05330f8cc | 247 | calling this twice is propably faster than if statements... */ |
| darran | 0:55a05330f8cc | 248 | sum = FOLD_U32T(sum); |
| darran | 0:55a05330f8cc | 249 | sum = FOLD_U32T(sum); |
| darran | 0:55a05330f8cc | 250 | |
| darran | 0:55a05330f8cc | 251 | if (odd) { |
| darran | 0:55a05330f8cc | 252 | sum = SWAP_BYTES_IN_WORD(sum); |
| darran | 0:55a05330f8cc | 253 | } |
| darran | 0:55a05330f8cc | 254 | |
| darran | 0:55a05330f8cc | 255 | return (u16_t)sum; |
| darran | 0:55a05330f8cc | 256 | } |
| darran | 0:55a05330f8cc | 257 | #endif |
| darran | 0:55a05330f8cc | 258 | |
| darran | 0:55a05330f8cc | 259 | /* inet_chksum_pseudo: |
| darran | 0:55a05330f8cc | 260 | * |
| darran | 0:55a05330f8cc | 261 | * Calculates the pseudo Internet checksum used by TCP and UDP for a pbuf chain. |
| darran | 0:55a05330f8cc | 262 | * IP addresses are expected to be in network byte order. |
| darran | 0:55a05330f8cc | 263 | * |
| darran | 0:55a05330f8cc | 264 | * @param p chain of pbufs over that a checksum should be calculated (ip data part) |
| darran | 0:55a05330f8cc | 265 | * @param src source ip address (used for checksum of pseudo header) |
| darran | 0:55a05330f8cc | 266 | * @param dst destination ip address (used for checksum of pseudo header) |
| darran | 0:55a05330f8cc | 267 | * @param proto ip protocol (used for checksum of pseudo header) |
| darran | 0:55a05330f8cc | 268 | * @param proto_len length of the ip data part (used for checksum of pseudo header) |
| darran | 0:55a05330f8cc | 269 | * @return checksum (as u16_t) to be saved directly in the protocol header |
| darran | 0:55a05330f8cc | 270 | */ |
| darran | 0:55a05330f8cc | 271 | u16_t |
| darran | 0:55a05330f8cc | 272 | inet_chksum_pseudo(struct pbuf *p, |
| darran | 0:55a05330f8cc | 273 | ip_addr_t *src, ip_addr_t *dest, |
| darran | 0:55a05330f8cc | 274 | u8_t proto, u16_t proto_len) |
| darran | 0:55a05330f8cc | 275 | { |
| darran | 0:55a05330f8cc | 276 | u32_t acc; |
| darran | 0:55a05330f8cc | 277 | u32_t addr; |
| darran | 0:55a05330f8cc | 278 | struct pbuf *q; |
| darran | 0:55a05330f8cc | 279 | u8_t swapped; |
| darran | 0:55a05330f8cc | 280 | |
| darran | 0:55a05330f8cc | 281 | acc = 0; |
| darran | 0:55a05330f8cc | 282 | swapped = 0; |
| darran | 0:55a05330f8cc | 283 | /* iterate through all pbuf in chain */ |
| darran | 0:55a05330f8cc | 284 | for(q = p; q != NULL; q = q->next) { |
| darran | 0:55a05330f8cc | 285 | LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): checksumming pbuf %p (has next %p) \n", |
| darran | 0:55a05330f8cc | 286 | (void *)q, (void *)q->next)); |
| darran | 0:55a05330f8cc | 287 | acc += LWIP_CHKSUM(q->payload, q->len); |
| darran | 0:55a05330f8cc | 288 | /*LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): unwrapped lwip_chksum()=%"X32_F" \n", acc));*/ |
| darran | 0:55a05330f8cc | 289 | /* just executing this next line is probably faster that the if statement needed |
| darran | 0:55a05330f8cc | 290 | to check whether we really need to execute it, and does no harm */ |
| darran | 0:55a05330f8cc | 291 | acc = FOLD_U32T(acc); |
| darran | 0:55a05330f8cc | 292 | if (q->len % 2 != 0) { |
| darran | 0:55a05330f8cc | 293 | swapped = 1 - swapped; |
| darran | 0:55a05330f8cc | 294 | acc = SWAP_BYTES_IN_WORD(acc); |
| darran | 0:55a05330f8cc | 295 | } |
| darran | 0:55a05330f8cc | 296 | /*LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): wrapped lwip_chksum()=%"X32_F" \n", acc));*/ |
| darran | 0:55a05330f8cc | 297 | } |
| darran | 0:55a05330f8cc | 298 | |
| darran | 0:55a05330f8cc | 299 | if (swapped) { |
| darran | 0:55a05330f8cc | 300 | acc = SWAP_BYTES_IN_WORD(acc); |
| darran | 0:55a05330f8cc | 301 | } |
| darran | 0:55a05330f8cc | 302 | addr = ip4_addr_get_u32(src); |
| darran | 0:55a05330f8cc | 303 | acc += (addr & 0xffffUL); |
| darran | 0:55a05330f8cc | 304 | acc += ((addr >> 16) & 0xffffUL); |
| darran | 0:55a05330f8cc | 305 | addr = ip4_addr_get_u32(dest); |
| darran | 0:55a05330f8cc | 306 | acc += (addr & 0xffffUL); |
| darran | 0:55a05330f8cc | 307 | acc += ((addr >> 16) & 0xffffUL); |
| darran | 0:55a05330f8cc | 308 | acc += (u32_t)htons((u16_t)proto); |
| darran | 0:55a05330f8cc | 309 | acc += (u32_t)htons(proto_len); |
| darran | 0:55a05330f8cc | 310 | |
| darran | 0:55a05330f8cc | 311 | /* Fold 32-bit sum to 16 bits |
| darran | 0:55a05330f8cc | 312 | calling this twice is propably faster than if statements... */ |
| darran | 0:55a05330f8cc | 313 | acc = FOLD_U32T(acc); |
| darran | 0:55a05330f8cc | 314 | acc = FOLD_U32T(acc); |
| darran | 0:55a05330f8cc | 315 | LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): pbuf chain lwip_chksum()=%"X32_F"\n", acc)); |
| darran | 0:55a05330f8cc | 316 | return (u16_t)~(acc & 0xffffUL); |
| darran | 0:55a05330f8cc | 317 | } |
| darran | 0:55a05330f8cc | 318 | |
| darran | 0:55a05330f8cc | 319 | /* inet_chksum_pseudo: |
| darran | 0:55a05330f8cc | 320 | * |
| darran | 0:55a05330f8cc | 321 | * Calculates the pseudo Internet checksum used by TCP and UDP for a pbuf chain. |
| darran | 0:55a05330f8cc | 322 | * IP addresses are expected to be in network byte order. |
| darran | 0:55a05330f8cc | 323 | * |
| darran | 0:55a05330f8cc | 324 | * @param p chain of pbufs over that a checksum should be calculated (ip data part) |
| darran | 0:55a05330f8cc | 325 | * @param src source ip address (used for checksum of pseudo header) |
| darran | 0:55a05330f8cc | 326 | * @param dst destination ip address (used for checksum of pseudo header) |
| darran | 0:55a05330f8cc | 327 | * @param proto ip protocol (used for checksum of pseudo header) |
| darran | 0:55a05330f8cc | 328 | * @param proto_len length of the ip data part (used for checksum of pseudo header) |
| darran | 0:55a05330f8cc | 329 | * @return checksum (as u16_t) to be saved directly in the protocol header |
| darran | 0:55a05330f8cc | 330 | */ |
| darran | 0:55a05330f8cc | 331 | u16_t |
| darran | 0:55a05330f8cc | 332 | inet_chksum_pseudo_partial(struct pbuf *p, |
| darran | 0:55a05330f8cc | 333 | ip_addr_t *src, ip_addr_t *dest, |
| darran | 0:55a05330f8cc | 334 | u8_t proto, u16_t proto_len, u16_t chksum_len) |
| darran | 0:55a05330f8cc | 335 | { |
| darran | 0:55a05330f8cc | 336 | u32_t acc; |
| darran | 0:55a05330f8cc | 337 | u32_t addr; |
| darran | 0:55a05330f8cc | 338 | struct pbuf *q; |
| darran | 0:55a05330f8cc | 339 | u8_t swapped; |
| darran | 0:55a05330f8cc | 340 | u16_t chklen; |
| darran | 0:55a05330f8cc | 341 | |
| darran | 0:55a05330f8cc | 342 | acc = 0; |
| darran | 0:55a05330f8cc | 343 | swapped = 0; |
| darran | 0:55a05330f8cc | 344 | /* iterate through all pbuf in chain */ |
| darran | 0:55a05330f8cc | 345 | for(q = p; (q != NULL) && (chksum_len > 0); q = q->next) { |
| darran | 0:55a05330f8cc | 346 | LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): checksumming pbuf %p (has next %p) \n", |
| darran | 0:55a05330f8cc | 347 | (void *)q, (void *)q->next)); |
| darran | 0:55a05330f8cc | 348 | chklen = q->len; |
| darran | 0:55a05330f8cc | 349 | if (chklen > chksum_len) { |
| darran | 0:55a05330f8cc | 350 | chklen = chksum_len; |
| darran | 0:55a05330f8cc | 351 | } |
| darran | 0:55a05330f8cc | 352 | acc += LWIP_CHKSUM(q->payload, chklen); |
| darran | 0:55a05330f8cc | 353 | chksum_len -= chklen; |
| darran | 0:55a05330f8cc | 354 | LWIP_ASSERT("delete me", chksum_len < 0x7fff); |
| darran | 0:55a05330f8cc | 355 | /*LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): unwrapped lwip_chksum()=%"X32_F" \n", acc));*/ |
| darran | 0:55a05330f8cc | 356 | /* fold the upper bit down */ |
| darran | 0:55a05330f8cc | 357 | acc = FOLD_U32T(acc); |
| darran | 0:55a05330f8cc | 358 | if (q->len % 2 != 0) { |
| darran | 0:55a05330f8cc | 359 | swapped = 1 - swapped; |
| darran | 0:55a05330f8cc | 360 | acc = SWAP_BYTES_IN_WORD(acc); |
| darran | 0:55a05330f8cc | 361 | } |
| darran | 0:55a05330f8cc | 362 | /*LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): wrapped lwip_chksum()=%"X32_F" \n", acc));*/ |
| darran | 0:55a05330f8cc | 363 | } |
| darran | 0:55a05330f8cc | 364 | |
| darran | 0:55a05330f8cc | 365 | if (swapped) { |
| darran | 0:55a05330f8cc | 366 | acc = SWAP_BYTES_IN_WORD(acc); |
| darran | 0:55a05330f8cc | 367 | } |
| darran | 0:55a05330f8cc | 368 | addr = ip4_addr_get_u32(src); |
| darran | 0:55a05330f8cc | 369 | acc += (addr & 0xffffUL); |
| darran | 0:55a05330f8cc | 370 | acc += ((addr >> 16) & 0xffffUL); |
| darran | 0:55a05330f8cc | 371 | addr = ip4_addr_get_u32(dest); |
| darran | 0:55a05330f8cc | 372 | acc += (addr & 0xffffUL); |
| darran | 0:55a05330f8cc | 373 | acc += ((addr >> 16) & 0xffffUL); |
| darran | 0:55a05330f8cc | 374 | acc += (u32_t)htons((u16_t)proto); |
| darran | 0:55a05330f8cc | 375 | acc += (u32_t)htons(proto_len); |
| darran | 0:55a05330f8cc | 376 | |
| darran | 0:55a05330f8cc | 377 | /* Fold 32-bit sum to 16 bits |
| darran | 0:55a05330f8cc | 378 | calling this twice is propably faster than if statements... */ |
| darran | 0:55a05330f8cc | 379 | acc = FOLD_U32T(acc); |
| darran | 0:55a05330f8cc | 380 | acc = FOLD_U32T(acc); |
| darran | 0:55a05330f8cc | 381 | LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): pbuf chain lwip_chksum()=%"X32_F"\n", acc)); |
| darran | 0:55a05330f8cc | 382 | return (u16_t)~(acc & 0xffffUL); |
| darran | 0:55a05330f8cc | 383 | } |
| darran | 0:55a05330f8cc | 384 | |
| darran | 0:55a05330f8cc | 385 | /* inet_chksum: |
| darran | 0:55a05330f8cc | 386 | * |
| darran | 0:55a05330f8cc | 387 | * Calculates the Internet checksum over a portion of memory. Used primarily for IP |
| darran | 0:55a05330f8cc | 388 | * and ICMP. |
| darran | 0:55a05330f8cc | 389 | * |
| darran | 0:55a05330f8cc | 390 | * @param dataptr start of the buffer to calculate the checksum (no alignment needed) |
| darran | 0:55a05330f8cc | 391 | * @param len length of the buffer to calculate the checksum |
| darran | 0:55a05330f8cc | 392 | * @return checksum (as u16_t) to be saved directly in the protocol header |
| darran | 0:55a05330f8cc | 393 | */ |
| darran | 0:55a05330f8cc | 394 | |
| darran | 0:55a05330f8cc | 395 | u16_t |
| darran | 0:55a05330f8cc | 396 | inet_chksum(void *dataptr, u16_t len) |
| darran | 0:55a05330f8cc | 397 | { |
| darran | 0:55a05330f8cc | 398 | return ~LWIP_CHKSUM(dataptr, len); |
| darran | 0:55a05330f8cc | 399 | } |
| darran | 0:55a05330f8cc | 400 | |
| darran | 0:55a05330f8cc | 401 | /** |
| darran | 0:55a05330f8cc | 402 | * Calculate a checksum over a chain of pbufs (without pseudo-header, much like |
| darran | 0:55a05330f8cc | 403 | * inet_chksum only pbufs are used). |
| darran | 0:55a05330f8cc | 404 | * |
| darran | 0:55a05330f8cc | 405 | * @param p pbuf chain over that the checksum should be calculated |
| darran | 0:55a05330f8cc | 406 | * @return checksum (as u16_t) to be saved directly in the protocol header |
| darran | 0:55a05330f8cc | 407 | */ |
| darran | 0:55a05330f8cc | 408 | u16_t |
| darran | 0:55a05330f8cc | 409 | inet_chksum_pbuf(struct pbuf *p) |
| darran | 0:55a05330f8cc | 410 | { |
| darran | 0:55a05330f8cc | 411 | u32_t acc; |
| darran | 0:55a05330f8cc | 412 | struct pbuf *q; |
| darran | 0:55a05330f8cc | 413 | u8_t swapped; |
| darran | 0:55a05330f8cc | 414 | |
| darran | 0:55a05330f8cc | 415 | acc = 0; |
| darran | 0:55a05330f8cc | 416 | swapped = 0; |
| darran | 0:55a05330f8cc | 417 | for(q = p; q != NULL; q = q->next) { |
| darran | 0:55a05330f8cc | 418 | acc += LWIP_CHKSUM(q->payload, q->len); |
| darran | 0:55a05330f8cc | 419 | acc = FOLD_U32T(acc); |
| darran | 0:55a05330f8cc | 420 | if (q->len % 2 != 0) { |
| darran | 0:55a05330f8cc | 421 | swapped = 1 - swapped; |
| darran | 0:55a05330f8cc | 422 | acc = SWAP_BYTES_IN_WORD(acc); |
| darran | 0:55a05330f8cc | 423 | } |
| darran | 0:55a05330f8cc | 424 | } |
| darran | 0:55a05330f8cc | 425 | |
| darran | 0:55a05330f8cc | 426 | if (swapped) { |
| darran | 0:55a05330f8cc | 427 | acc = SWAP_BYTES_IN_WORD(acc); |
| darran | 0:55a05330f8cc | 428 | } |
| darran | 0:55a05330f8cc | 429 | return (u16_t)~(acc & 0xffffUL); |
| darran | 0:55a05330f8cc | 430 | } |
| darran | 0:55a05330f8cc | 431 | |
| darran | 0:55a05330f8cc | 432 | /* These are some implementations for LWIP_CHKSUM_COPY, which copies data |
| darran | 0:55a05330f8cc | 433 | * like MEMCPY but generates a checksum at the same time. Since this is a |
| darran | 0:55a05330f8cc | 434 | * performance-sensitive function, you might want to create your own version |
| darran | 0:55a05330f8cc | 435 | * in assembly targeted at your hardware by defining it in lwipopts.h: |
| darran | 0:55a05330f8cc | 436 | * #define LWIP_CHKSUM_COPY(dst, src, len) your_chksum_copy(dst, src, len) |
| darran | 0:55a05330f8cc | 437 | */ |
| darran | 0:55a05330f8cc | 438 | |
| darran | 0:55a05330f8cc | 439 | #if (LWIP_CHKSUM_COPY_ALGORITHM == 1) /* Version #1 */ |
| darran | 0:55a05330f8cc | 440 | /** Safe but slow: first call MEMCPY, then call LWIP_CHKSUM. |
| darran | 0:55a05330f8cc | 441 | * For architectures with big caches, data might still be in cache when |
| darran | 0:55a05330f8cc | 442 | * generating the checksum after copying. |
| darran | 0:55a05330f8cc | 443 | */ |
| darran | 0:55a05330f8cc | 444 | u16_t |
| darran | 0:55a05330f8cc | 445 | lwip_chksum_copy(void *dst, const void *src, u16_t len) |
| darran | 0:55a05330f8cc | 446 | { |
| darran | 0:55a05330f8cc | 447 | MEMCPY(dst, src, len); |
| darran | 0:55a05330f8cc | 448 | return LWIP_CHKSUM(dst, len); |
| darran | 0:55a05330f8cc | 449 | } |
| darran | 0:55a05330f8cc | 450 | #endif /* (LWIP_CHKSUM_COPY_ALGORITHM == 1) */ |