Pehr Hovey
Some quick code to use UDP-only (no TCP) with mBed. Echos received packets and sends packets when a button is pressed
Core/lwIP/core/ipv4/inet_chksum.c@0:a548a085de55, 2010-03-14 (annotated)
- Committer:
- pehrhovey
- Date:
- Sun Mar 14 00:54:12 2010 +0000
- Revision:
- 0:a548a085de55
Who changed what in which revision?
| User | Revision | Line number | New contents of line |
|---|---|---|---|
| pehrhovey | 0:a548a085de55 | 1 | /** |
| pehrhovey | 0:a548a085de55 | 2 | * @file |
| pehrhovey | 0:a548a085de55 | 3 | * Incluse internet checksum functions. |
| pehrhovey | 0:a548a085de55 | 4 | * |
| pehrhovey | 0:a548a085de55 | 5 | */ |
| pehrhovey | 0:a548a085de55 | 6 | |
| pehrhovey | 0:a548a085de55 | 7 | /* |
| pehrhovey | 0:a548a085de55 | 8 | * Copyright (c) 2001-2004 Swedish Institute of Computer Science. |
| pehrhovey | 0:a548a085de55 | 9 | * All rights reserved. |
| pehrhovey | 0:a548a085de55 | 10 | * |
| pehrhovey | 0:a548a085de55 | 11 | * Redistribution and use in source and binary forms, with or without modification, |
| pehrhovey | 0:a548a085de55 | 12 | * are permitted provided that the following conditions are met: |
| pehrhovey | 0:a548a085de55 | 13 | * |
| pehrhovey | 0:a548a085de55 | 14 | * 1. Redistributions of source code must retain the above copyright notice, |
| pehrhovey | 0:a548a085de55 | 15 | * this list of conditions and the following disclaimer. |
| pehrhovey | 0:a548a085de55 | 16 | * 2. Redistributions in binary form must reproduce the above copyright notice, |
| pehrhovey | 0:a548a085de55 | 17 | * this list of conditions and the following disclaimer in the documentation |
| pehrhovey | 0:a548a085de55 | 18 | * and/or other materials provided with the distribution. |
| pehrhovey | 0:a548a085de55 | 19 | * 3. The name of the author may not be used to endorse or promote products |
| pehrhovey | 0:a548a085de55 | 20 | * derived from this software without specific prior written permission. |
| pehrhovey | 0:a548a085de55 | 21 | * |
| pehrhovey | 0:a548a085de55 | 22 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED |
| pehrhovey | 0:a548a085de55 | 23 | * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF |
| pehrhovey | 0:a548a085de55 | 24 | * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT |
| pehrhovey | 0:a548a085de55 | 25 | * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, |
| pehrhovey | 0:a548a085de55 | 26 | * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT |
| pehrhovey | 0:a548a085de55 | 27 | * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| pehrhovey | 0:a548a085de55 | 28 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| pehrhovey | 0:a548a085de55 | 29 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING |
| pehrhovey | 0:a548a085de55 | 30 | * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY |
| pehrhovey | 0:a548a085de55 | 31 | * OF SUCH DAMAGE. |
| pehrhovey | 0:a548a085de55 | 32 | * |
| pehrhovey | 0:a548a085de55 | 33 | * This file is part of the lwIP TCP/IP stack. |
| pehrhovey | 0:a548a085de55 | 34 | * |
| pehrhovey | 0:a548a085de55 | 35 | * Author: Adam Dunkels <adam@sics.se> |
| pehrhovey | 0:a548a085de55 | 36 | * |
| pehrhovey | 0:a548a085de55 | 37 | */ |
| pehrhovey | 0:a548a085de55 | 38 | |
| pehrhovey | 0:a548a085de55 | 39 | #include "lwip/opt.h" |
| pehrhovey | 0:a548a085de55 | 40 | |
| pehrhovey | 0:a548a085de55 | 41 | #include "lwip/inet_chksum.h" |
| pehrhovey | 0:a548a085de55 | 42 | #include "lwip/inet.h" |
| pehrhovey | 0:a548a085de55 | 43 | |
| pehrhovey | 0:a548a085de55 | 44 | #include <stddef.h> |
| pehrhovey | 0:a548a085de55 | 45 | |
| pehrhovey | 0:a548a085de55 | 46 | /* These are some reference implementations of the checksum algorithm, with the |
| pehrhovey | 0:a548a085de55 | 47 | * aim of being simple, correct and fully portable. Checksumming is the |
| pehrhovey | 0:a548a085de55 | 48 | * first thing you would want to optimize for your platform. If you create |
| pehrhovey | 0:a548a085de55 | 49 | * your own version, link it in and in your cc.h put: |
| pehrhovey | 0:a548a085de55 | 50 | * |
| pehrhovey | 0:a548a085de55 | 51 | * #define LWIP_CHKSUM <your_checksum_routine> |
| pehrhovey | 0:a548a085de55 | 52 | * |
| pehrhovey | 0:a548a085de55 | 53 | * Or you can select from the implementations below by defining |
| pehrhovey | 0:a548a085de55 | 54 | * LWIP_CHKSUM_ALGORITHM to 1, 2 or 3. |
| pehrhovey | 0:a548a085de55 | 55 | */ |
| pehrhovey | 0:a548a085de55 | 56 | |
| pehrhovey | 0:a548a085de55 | 57 | #ifndef LWIP_CHKSUM |
| pehrhovey | 0:a548a085de55 | 58 | # define LWIP_CHKSUM lwip_standard_chksum |
| pehrhovey | 0:a548a085de55 | 59 | # ifndef LWIP_CHKSUM_ALGORITHM |
| pehrhovey | 0:a548a085de55 | 60 | # define LWIP_CHKSUM_ALGORITHM 1 |
| pehrhovey | 0:a548a085de55 | 61 | # endif |
| pehrhovey | 0:a548a085de55 | 62 | #endif |
| pehrhovey | 0:a548a085de55 | 63 | /* If none set: */ |
| pehrhovey | 0:a548a085de55 | 64 | #ifndef LWIP_CHKSUM_ALGORITHM |
| pehrhovey | 0:a548a085de55 | 65 | # define LWIP_CHKSUM_ALGORITHM 0 |
| pehrhovey | 0:a548a085de55 | 66 | #endif |
| pehrhovey | 0:a548a085de55 | 67 | |
| pehrhovey | 0:a548a085de55 | 68 | /** Like the name says... */ |
| pehrhovey | 0:a548a085de55 | 69 | #if LWIP_PLATFORM_BYTESWAP && (BYTE_ORDER == LITTLE_ENDIAN) |
| pehrhovey | 0:a548a085de55 | 70 | /* little endian and PLATFORM_BYTESWAP defined */ |
| pehrhovey | 0:a548a085de55 | 71 | #define SWAP_BYTES_IN_WORD(w) LWIP_PLATFORM_HTONS(w) |
| pehrhovey | 0:a548a085de55 | 72 | #else |
| pehrhovey | 0:a548a085de55 | 73 | /* can't use htons on big endian (or PLATFORM_BYTESWAP not defined)... */ |
| pehrhovey | 0:a548a085de55 | 74 | #define SWAP_BYTES_IN_WORD(w) ((w & 0xff) << 8) | ((w & 0xff00) >> 8) |
| pehrhovey | 0:a548a085de55 | 75 | #endif |
| pehrhovey | 0:a548a085de55 | 76 | |
| pehrhovey | 0:a548a085de55 | 77 | /** Split an u32_t in two u16_ts and add them up */ |
| pehrhovey | 0:a548a085de55 | 78 | #define FOLD_U32T(u) ((u >> 16) + (u & 0x0000ffffUL)) |
| pehrhovey | 0:a548a085de55 | 79 | |
| pehrhovey | 0:a548a085de55 | 80 | #if (LWIP_CHKSUM_ALGORITHM == 1) /* Version #1 */ |
| pehrhovey | 0:a548a085de55 | 81 | /** |
| pehrhovey | 0:a548a085de55 | 82 | * lwip checksum |
| pehrhovey | 0:a548a085de55 | 83 | * |
| pehrhovey | 0:a548a085de55 | 84 | * @param dataptr points to start of data to be summed at any boundary |
| pehrhovey | 0:a548a085de55 | 85 | * @param len length of data to be summed |
| pehrhovey | 0:a548a085de55 | 86 | * @return host order (!) lwip checksum (non-inverted Internet sum) |
| pehrhovey | 0:a548a085de55 | 87 | * |
| pehrhovey | 0:a548a085de55 | 88 | * @note accumulator size limits summable length to 64k |
| pehrhovey | 0:a548a085de55 | 89 | * @note host endianess is irrelevant (p3 RFC1071) |
| pehrhovey | 0:a548a085de55 | 90 | */ |
| pehrhovey | 0:a548a085de55 | 91 | static u16_t |
| pehrhovey | 0:a548a085de55 | 92 | lwip_standard_chksum(void *dataptr, u16_t len) |
| pehrhovey | 0:a548a085de55 | 93 | { |
| pehrhovey | 0:a548a085de55 | 94 | u32_t acc; |
| pehrhovey | 0:a548a085de55 | 95 | u16_t src; |
| pehrhovey | 0:a548a085de55 | 96 | u8_t *octetptr; |
| pehrhovey | 0:a548a085de55 | 97 | |
| pehrhovey | 0:a548a085de55 | 98 | acc = 0; |
| pehrhovey | 0:a548a085de55 | 99 | /* dataptr may be at odd or even addresses */ |
| pehrhovey | 0:a548a085de55 | 100 | octetptr = (u8_t*)dataptr; |
| pehrhovey | 0:a548a085de55 | 101 | while (len > 1) { |
| pehrhovey | 0:a548a085de55 | 102 | /* declare first octet as most significant |
| pehrhovey | 0:a548a085de55 | 103 | thus assume network order, ignoring host order */ |
| pehrhovey | 0:a548a085de55 | 104 | src = (*octetptr) << 8; |
| pehrhovey | 0:a548a085de55 | 105 | octetptr++; |
| pehrhovey | 0:a548a085de55 | 106 | /* declare second octet as least significant */ |
| pehrhovey | 0:a548a085de55 | 107 | src |= (*octetptr); |
| pehrhovey | 0:a548a085de55 | 108 | octetptr++; |
| pehrhovey | 0:a548a085de55 | 109 | acc += src; |
| pehrhovey | 0:a548a085de55 | 110 | len -= 2; |
| pehrhovey | 0:a548a085de55 | 111 | } |
| pehrhovey | 0:a548a085de55 | 112 | if (len > 0) { |
| pehrhovey | 0:a548a085de55 | 113 | /* accumulate remaining octet */ |
| pehrhovey | 0:a548a085de55 | 114 | src = (*octetptr) << 8; |
| pehrhovey | 0:a548a085de55 | 115 | acc += src; |
| pehrhovey | 0:a548a085de55 | 116 | } |
| pehrhovey | 0:a548a085de55 | 117 | /* add deferred carry bits */ |
| pehrhovey | 0:a548a085de55 | 118 | acc = (acc >> 16) + (acc & 0x0000ffffUL); |
| pehrhovey | 0:a548a085de55 | 119 | if ((acc & 0xffff0000UL) != 0) { |
| pehrhovey | 0:a548a085de55 | 120 | acc = (acc >> 16) + (acc & 0x0000ffffUL); |
| pehrhovey | 0:a548a085de55 | 121 | } |
| pehrhovey | 0:a548a085de55 | 122 | /* This maybe a little confusing: reorder sum using htons() |
| pehrhovey | 0:a548a085de55 | 123 | instead of ntohs() since it has a little less call overhead. |
| pehrhovey | 0:a548a085de55 | 124 | The caller must invert bits for Internet sum ! */ |
| pehrhovey | 0:a548a085de55 | 125 | return htons((u16_t)acc); |
| pehrhovey | 0:a548a085de55 | 126 | } |
| pehrhovey | 0:a548a085de55 | 127 | #endif |
| pehrhovey | 0:a548a085de55 | 128 | |
| pehrhovey | 0:a548a085de55 | 129 | #if (LWIP_CHKSUM_ALGORITHM == 2) /* Alternative version #2 */ |
| pehrhovey | 0:a548a085de55 | 130 | /* |
| pehrhovey | 0:a548a085de55 | 131 | * Curt McDowell |
| pehrhovey | 0:a548a085de55 | 132 | * Broadcom Corp. |
| pehrhovey | 0:a548a085de55 | 133 | * csm@broadcom.com |
| pehrhovey | 0:a548a085de55 | 134 | * |
| pehrhovey | 0:a548a085de55 | 135 | * IP checksum two bytes at a time with support for |
| pehrhovey | 0:a548a085de55 | 136 | * unaligned buffer. |
| pehrhovey | 0:a548a085de55 | 137 | * Works for len up to and including 0x20000. |
| pehrhovey | 0:a548a085de55 | 138 | * by Curt McDowell, Broadcom Corp. 12/08/2005 |
| pehrhovey | 0:a548a085de55 | 139 | * |
| pehrhovey | 0:a548a085de55 | 140 | * @param dataptr points to start of data to be summed at any boundary |
| pehrhovey | 0:a548a085de55 | 141 | * @param len length of data to be summed |
| pehrhovey | 0:a548a085de55 | 142 | * @return host order (!) lwip checksum (non-inverted Internet sum) |
| pehrhovey | 0:a548a085de55 | 143 | */ |
| pehrhovey | 0:a548a085de55 | 144 | |
| pehrhovey | 0:a548a085de55 | 145 | static u16_t |
| pehrhovey | 0:a548a085de55 | 146 | lwip_standard_chksum(void *dataptr, int len) |
| pehrhovey | 0:a548a085de55 | 147 | { |
| pehrhovey | 0:a548a085de55 | 148 | u8_t *pb = dataptr; |
| pehrhovey | 0:a548a085de55 | 149 | u16_t *ps, t = 0; |
| pehrhovey | 0:a548a085de55 | 150 | u32_t sum = 0; |
| pehrhovey | 0:a548a085de55 | 151 | int odd = ((u32_t)pb & 1); |
| pehrhovey | 0:a548a085de55 | 152 | |
| pehrhovey | 0:a548a085de55 | 153 | /* Get aligned to u16_t */ |
| pehrhovey | 0:a548a085de55 | 154 | if (odd && len > 0) { |
| pehrhovey | 0:a548a085de55 | 155 | ((u8_t *)&t)[1] = *pb++; |
| pehrhovey | 0:a548a085de55 | 156 | len--; |
| pehrhovey | 0:a548a085de55 | 157 | } |
| pehrhovey | 0:a548a085de55 | 158 | |
| pehrhovey | 0:a548a085de55 | 159 | /* Add the bulk of the data */ |
| pehrhovey | 0:a548a085de55 | 160 | ps = (u16_t *)pb; |
| pehrhovey | 0:a548a085de55 | 161 | while (len > 1) { |
| pehrhovey | 0:a548a085de55 | 162 | sum += *ps++; |
| pehrhovey | 0:a548a085de55 | 163 | len -= 2; |
| pehrhovey | 0:a548a085de55 | 164 | } |
| pehrhovey | 0:a548a085de55 | 165 | |
| pehrhovey | 0:a548a085de55 | 166 | /* Consume left-over byte, if any */ |
| pehrhovey | 0:a548a085de55 | 167 | if (len > 0) { |
| pehrhovey | 0:a548a085de55 | 168 | ((u8_t *)&t)[0] = *(u8_t *)ps;; |
| pehrhovey | 0:a548a085de55 | 169 | } |
| pehrhovey | 0:a548a085de55 | 170 | |
| pehrhovey | 0:a548a085de55 | 171 | /* Add end bytes */ |
| pehrhovey | 0:a548a085de55 | 172 | sum += t; |
| pehrhovey | 0:a548a085de55 | 173 | |
| pehrhovey | 0:a548a085de55 | 174 | /* Fold 32-bit sum to 16 bits |
| pehrhovey | 0:a548a085de55 | 175 | calling this twice is propably faster than if statements... */ |
| pehrhovey | 0:a548a085de55 | 176 | sum = FOLD_U32T(sum); |
| pehrhovey | 0:a548a085de55 | 177 | sum = FOLD_U32T(sum); |
| pehrhovey | 0:a548a085de55 | 178 | |
| pehrhovey | 0:a548a085de55 | 179 | /* Swap if alignment was odd */ |
| pehrhovey | 0:a548a085de55 | 180 | if (odd) { |
| pehrhovey | 0:a548a085de55 | 181 | sum = SWAP_BYTES_IN_WORD(sum); |
| pehrhovey | 0:a548a085de55 | 182 | } |
| pehrhovey | 0:a548a085de55 | 183 | |
| pehrhovey | 0:a548a085de55 | 184 | return sum; |
| pehrhovey | 0:a548a085de55 | 185 | } |
| pehrhovey | 0:a548a085de55 | 186 | #endif |
| pehrhovey | 0:a548a085de55 | 187 | |
| pehrhovey | 0:a548a085de55 | 188 | #if (LWIP_CHKSUM_ALGORITHM == 3) /* Alternative version #3 */ |
| pehrhovey | 0:a548a085de55 | 189 | /** |
| pehrhovey | 0:a548a085de55 | 190 | * An optimized checksum routine. Basically, it uses loop-unrolling on |
| pehrhovey | 0:a548a085de55 | 191 | * the checksum loop, treating the head and tail bytes specially, whereas |
| pehrhovey | 0:a548a085de55 | 192 | * the inner loop acts on 8 bytes at a time. |
| pehrhovey | 0:a548a085de55 | 193 | * |
| pehrhovey | 0:a548a085de55 | 194 | * @arg start of buffer to be checksummed. May be an odd byte address. |
| pehrhovey | 0:a548a085de55 | 195 | * @len number of bytes in the buffer to be checksummed. |
| pehrhovey | 0:a548a085de55 | 196 | * @return host order (!) lwip checksum (non-inverted Internet sum) |
| pehrhovey | 0:a548a085de55 | 197 | * |
| pehrhovey | 0:a548a085de55 | 198 | * by Curt McDowell, Broadcom Corp. December 8th, 2005 |
| pehrhovey | 0:a548a085de55 | 199 | */ |
| pehrhovey | 0:a548a085de55 | 200 | |
| pehrhovey | 0:a548a085de55 | 201 | static u16_t |
| pehrhovey | 0:a548a085de55 | 202 | lwip_standard_chksum(void *dataptr, int len) |
| pehrhovey | 0:a548a085de55 | 203 | { |
| pehrhovey | 0:a548a085de55 | 204 | u8_t *pb = dataptr; |
| pehrhovey | 0:a548a085de55 | 205 | u16_t *ps, t = 0; |
| pehrhovey | 0:a548a085de55 | 206 | u32_t *pl; |
| pehrhovey | 0:a548a085de55 | 207 | u32_t sum = 0, tmp; |
| pehrhovey | 0:a548a085de55 | 208 | /* starts at odd byte address? */ |
| pehrhovey | 0:a548a085de55 | 209 | int odd = ((u32_t)pb & 1); |
| pehrhovey | 0:a548a085de55 | 210 | |
| pehrhovey | 0:a548a085de55 | 211 | if (odd && len > 0) { |
| pehrhovey | 0:a548a085de55 | 212 | ((u8_t *)&t)[1] = *pb++; |
| pehrhovey | 0:a548a085de55 | 213 | len--; |
| pehrhovey | 0:a548a085de55 | 214 | } |
| pehrhovey | 0:a548a085de55 | 215 | |
| pehrhovey | 0:a548a085de55 | 216 | ps = (u16_t *)pb; |
| pehrhovey | 0:a548a085de55 | 217 | |
| pehrhovey | 0:a548a085de55 | 218 | if (((u32_t)ps & 3) && len > 1) { |
| pehrhovey | 0:a548a085de55 | 219 | sum += *ps++; |
| pehrhovey | 0:a548a085de55 | 220 | len -= 2; |
| pehrhovey | 0:a548a085de55 | 221 | } |
| pehrhovey | 0:a548a085de55 | 222 | |
| pehrhovey | 0:a548a085de55 | 223 | pl = (u32_t *)ps; |
| pehrhovey | 0:a548a085de55 | 224 | |
| pehrhovey | 0:a548a085de55 | 225 | while (len > 7) { |
| pehrhovey | 0:a548a085de55 | 226 | tmp = sum + *pl++; /* ping */ |
| pehrhovey | 0:a548a085de55 | 227 | if (tmp < sum) { |
| pehrhovey | 0:a548a085de55 | 228 | tmp++; /* add back carry */ |
| pehrhovey | 0:a548a085de55 | 229 | } |
| pehrhovey | 0:a548a085de55 | 230 | |
| pehrhovey | 0:a548a085de55 | 231 | sum = tmp + *pl++; /* pong */ |
| pehrhovey | 0:a548a085de55 | 232 | if (sum < tmp) { |
| pehrhovey | 0:a548a085de55 | 233 | sum++; /* add back carry */ |
| pehrhovey | 0:a548a085de55 | 234 | } |
| pehrhovey | 0:a548a085de55 | 235 | |
| pehrhovey | 0:a548a085de55 | 236 | len -= 8; |
| pehrhovey | 0:a548a085de55 | 237 | } |
| pehrhovey | 0:a548a085de55 | 238 | |
| pehrhovey | 0:a548a085de55 | 239 | /* make room in upper bits */ |
| pehrhovey | 0:a548a085de55 | 240 | sum = FOLD_U32T(sum); |
| pehrhovey | 0:a548a085de55 | 241 | |
| pehrhovey | 0:a548a085de55 | 242 | ps = (u16_t *)pl; |
| pehrhovey | 0:a548a085de55 | 243 | |
| pehrhovey | 0:a548a085de55 | 244 | /* 16-bit aligned word remaining? */ |
| pehrhovey | 0:a548a085de55 | 245 | while (len > 1) { |
| pehrhovey | 0:a548a085de55 | 246 | sum += *ps++; |
| pehrhovey | 0:a548a085de55 | 247 | len -= 2; |
| pehrhovey | 0:a548a085de55 | 248 | } |
| pehrhovey | 0:a548a085de55 | 249 | |
| pehrhovey | 0:a548a085de55 | 250 | /* dangling tail byte remaining? */ |
| pehrhovey | 0:a548a085de55 | 251 | if (len > 0) { /* include odd byte */ |
| pehrhovey | 0:a548a085de55 | 252 | ((u8_t *)&t)[0] = *(u8_t *)ps; |
| pehrhovey | 0:a548a085de55 | 253 | } |
| pehrhovey | 0:a548a085de55 | 254 | |
| pehrhovey | 0:a548a085de55 | 255 | sum += t; /* add end bytes */ |
| pehrhovey | 0:a548a085de55 | 256 | |
| pehrhovey | 0:a548a085de55 | 257 | /* Fold 32-bit sum to 16 bits |
| pehrhovey | 0:a548a085de55 | 258 | calling this twice is propably faster than if statements... */ |
| pehrhovey | 0:a548a085de55 | 259 | sum = FOLD_U32T(sum); |
| pehrhovey | 0:a548a085de55 | 260 | sum = FOLD_U32T(sum); |
| pehrhovey | 0:a548a085de55 | 261 | |
| pehrhovey | 0:a548a085de55 | 262 | if (odd) { |
| pehrhovey | 0:a548a085de55 | 263 | sum = SWAP_BYTES_IN_WORD(sum); |
| pehrhovey | 0:a548a085de55 | 264 | } |
| pehrhovey | 0:a548a085de55 | 265 | |
| pehrhovey | 0:a548a085de55 | 266 | return sum; |
| pehrhovey | 0:a548a085de55 | 267 | } |
| pehrhovey | 0:a548a085de55 | 268 | #endif |
| pehrhovey | 0:a548a085de55 | 269 | |
| pehrhovey | 0:a548a085de55 | 270 | /* inet_chksum_pseudo: |
| pehrhovey | 0:a548a085de55 | 271 | * |
| pehrhovey | 0:a548a085de55 | 272 | * Calculates the pseudo Internet checksum used by TCP and UDP for a pbuf chain. |
| pehrhovey | 0:a548a085de55 | 273 | * IP addresses are expected to be in network byte order. |
| pehrhovey | 0:a548a085de55 | 274 | * |
| pehrhovey | 0:a548a085de55 | 275 | * @param p chain of pbufs over that a checksum should be calculated (ip data part) |
| pehrhovey | 0:a548a085de55 | 276 | * @param src source ip address (used for checksum of pseudo header) |
| pehrhovey | 0:a548a085de55 | 277 | * @param dst destination ip address (used for checksum of pseudo header) |
| pehrhovey | 0:a548a085de55 | 278 | * @param proto ip protocol (used for checksum of pseudo header) |
| pehrhovey | 0:a548a085de55 | 279 | * @param proto_len length of the ip data part (used for checksum of pseudo header) |
| pehrhovey | 0:a548a085de55 | 280 | * @return checksum (as u16_t) to be saved directly in the protocol header |
| pehrhovey | 0:a548a085de55 | 281 | */ |
| pehrhovey | 0:a548a085de55 | 282 | u16_t |
| pehrhovey | 0:a548a085de55 | 283 | inet_chksum_pseudo(struct pbuf *p, |
| pehrhovey | 0:a548a085de55 | 284 | struct ip_addr *src, struct ip_addr *dest, |
| pehrhovey | 0:a548a085de55 | 285 | u8_t proto, u16_t proto_len) |
| pehrhovey | 0:a548a085de55 | 286 | { |
| pehrhovey | 0:a548a085de55 | 287 | u32_t acc; |
| pehrhovey | 0:a548a085de55 | 288 | struct pbuf *q; |
| pehrhovey | 0:a548a085de55 | 289 | u8_t swapped; |
| pehrhovey | 0:a548a085de55 | 290 | |
| pehrhovey | 0:a548a085de55 | 291 | acc = 0; |
| pehrhovey | 0:a548a085de55 | 292 | swapped = 0; |
| pehrhovey | 0:a548a085de55 | 293 | /* iterate through all pbuf in chain */ |
| pehrhovey | 0:a548a085de55 | 294 | for(q = p; q != NULL; q = q->next) { |
| pehrhovey | 0:a548a085de55 | 295 | LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): checksumming pbuf %p (has next %p) \n", |
| pehrhovey | 0:a548a085de55 | 296 | (void *)q, (void *)q->next)); |
| pehrhovey | 0:a548a085de55 | 297 | acc += LWIP_CHKSUM(q->payload, q->len); |
| pehrhovey | 0:a548a085de55 | 298 | /*LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): unwrapped lwip_chksum()=%"X32_F" \n", acc));*/ |
| pehrhovey | 0:a548a085de55 | 299 | /* just executing this next line is probably faster that the if statement needed |
| pehrhovey | 0:a548a085de55 | 300 | to check whether we really need to execute it, and does no harm */ |
| pehrhovey | 0:a548a085de55 | 301 | acc = FOLD_U32T(acc); |
| pehrhovey | 0:a548a085de55 | 302 | if (q->len % 2 != 0) { |
| pehrhovey | 0:a548a085de55 | 303 | swapped = 1 - swapped; |
| pehrhovey | 0:a548a085de55 | 304 | acc = SWAP_BYTES_IN_WORD(acc); |
| pehrhovey | 0:a548a085de55 | 305 | } |
| pehrhovey | 0:a548a085de55 | 306 | /*LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): wrapped lwip_chksum()=%"X32_F" \n", acc));*/ |
| pehrhovey | 0:a548a085de55 | 307 | } |
| pehrhovey | 0:a548a085de55 | 308 | |
| pehrhovey | 0:a548a085de55 | 309 | if (swapped) { |
| pehrhovey | 0:a548a085de55 | 310 | acc = SWAP_BYTES_IN_WORD(acc); |
| pehrhovey | 0:a548a085de55 | 311 | } |
| pehrhovey | 0:a548a085de55 | 312 | acc += (src->addr & 0xffffUL); |
| pehrhovey | 0:a548a085de55 | 313 | acc += ((src->addr >> 16) & 0xffffUL); |
| pehrhovey | 0:a548a085de55 | 314 | acc += (dest->addr & 0xffffUL); |
| pehrhovey | 0:a548a085de55 | 315 | acc += ((dest->addr >> 16) & 0xffffUL); |
| pehrhovey | 0:a548a085de55 | 316 | acc += (u32_t)htons((u16_t)proto); |
| pehrhovey | 0:a548a085de55 | 317 | acc += (u32_t)htons(proto_len); |
| pehrhovey | 0:a548a085de55 | 318 | |
| pehrhovey | 0:a548a085de55 | 319 | /* Fold 32-bit sum to 16 bits |
| pehrhovey | 0:a548a085de55 | 320 | calling this twice is propably faster than if statements... */ |
| pehrhovey | 0:a548a085de55 | 321 | acc = FOLD_U32T(acc); |
| pehrhovey | 0:a548a085de55 | 322 | acc = FOLD_U32T(acc); |
| pehrhovey | 0:a548a085de55 | 323 | LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): pbuf chain lwip_chksum()=%"X32_F"\n", acc)); |
| pehrhovey | 0:a548a085de55 | 324 | return (u16_t)~(acc & 0xffffUL); |
| pehrhovey | 0:a548a085de55 | 325 | } |
| pehrhovey | 0:a548a085de55 | 326 | |
| pehrhovey | 0:a548a085de55 | 327 | /* inet_chksum_pseudo: |
| pehrhovey | 0:a548a085de55 | 328 | * |
| pehrhovey | 0:a548a085de55 | 329 | * Calculates the pseudo Internet checksum used by TCP and UDP for a pbuf chain. |
| pehrhovey | 0:a548a085de55 | 330 | * IP addresses are expected to be in network byte order. |
| pehrhovey | 0:a548a085de55 | 331 | * |
| pehrhovey | 0:a548a085de55 | 332 | * @param p chain of pbufs over that a checksum should be calculated (ip data part) |
| pehrhovey | 0:a548a085de55 | 333 | * @param src source ip address (used for checksum of pseudo header) |
| pehrhovey | 0:a548a085de55 | 334 | * @param dst destination ip address (used for checksum of pseudo header) |
| pehrhovey | 0:a548a085de55 | 335 | * @param proto ip protocol (used for checksum of pseudo header) |
| pehrhovey | 0:a548a085de55 | 336 | * @param proto_len length of the ip data part (used for checksum of pseudo header) |
| pehrhovey | 0:a548a085de55 | 337 | * @return checksum (as u16_t) to be saved directly in the protocol header |
| pehrhovey | 0:a548a085de55 | 338 | */ |
| pehrhovey | 0:a548a085de55 | 339 | /* Currently only used by UDPLITE, although this could change in the future. */ |
| pehrhovey | 0:a548a085de55 | 340 | #if LWIP_UDPLITE |
| pehrhovey | 0:a548a085de55 | 341 | u16_t |
| pehrhovey | 0:a548a085de55 | 342 | inet_chksum_pseudo_partial(struct pbuf *p, |
| pehrhovey | 0:a548a085de55 | 343 | struct ip_addr *src, struct ip_addr *dest, |
| pehrhovey | 0:a548a085de55 | 344 | u8_t proto, u16_t proto_len, u16_t chksum_len) |
| pehrhovey | 0:a548a085de55 | 345 | { |
| pehrhovey | 0:a548a085de55 | 346 | u32_t acc; |
| pehrhovey | 0:a548a085de55 | 347 | struct pbuf *q; |
| pehrhovey | 0:a548a085de55 | 348 | u8_t swapped; |
| pehrhovey | 0:a548a085de55 | 349 | u16_t chklen; |
| pehrhovey | 0:a548a085de55 | 350 | |
| pehrhovey | 0:a548a085de55 | 351 | acc = 0; |
| pehrhovey | 0:a548a085de55 | 352 | swapped = 0; |
| pehrhovey | 0:a548a085de55 | 353 | /* iterate through all pbuf in chain */ |
| pehrhovey | 0:a548a085de55 | 354 | for(q = p; (q != NULL) && (chksum_len > 0); q = q->next) { |
| pehrhovey | 0:a548a085de55 | 355 | LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): checksumming pbuf %p (has next %p) \n", |
| pehrhovey | 0:a548a085de55 | 356 | (void *)q, (void *)q->next)); |
| pehrhovey | 0:a548a085de55 | 357 | chklen = q->len; |
| pehrhovey | 0:a548a085de55 | 358 | if (chklen > chksum_len) { |
| pehrhovey | 0:a548a085de55 | 359 | chklen = chksum_len; |
| pehrhovey | 0:a548a085de55 | 360 | } |
| pehrhovey | 0:a548a085de55 | 361 | acc += LWIP_CHKSUM(q->payload, chklen); |
| pehrhovey | 0:a548a085de55 | 362 | chksum_len -= chklen; |
| pehrhovey | 0:a548a085de55 | 363 | LWIP_ASSERT("delete me", chksum_len < 0x7fff); |
| pehrhovey | 0:a548a085de55 | 364 | /*LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): unwrapped lwip_chksum()=%"X32_F" \n", acc));*/ |
| pehrhovey | 0:a548a085de55 | 365 | /* fold the upper bit down */ |
| pehrhovey | 0:a548a085de55 | 366 | acc = FOLD_U32T(acc); |
| pehrhovey | 0:a548a085de55 | 367 | if (q->len % 2 != 0) { |
| pehrhovey | 0:a548a085de55 | 368 | swapped = 1 - swapped; |
| pehrhovey | 0:a548a085de55 | 369 | acc = SWAP_BYTES_IN_WORD(acc); |
| pehrhovey | 0:a548a085de55 | 370 | } |
| pehrhovey | 0:a548a085de55 | 371 | /*LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): wrapped lwip_chksum()=%"X32_F" \n", acc));*/ |
| pehrhovey | 0:a548a085de55 | 372 | } |
| pehrhovey | 0:a548a085de55 | 373 | |
| pehrhovey | 0:a548a085de55 | 374 | if (swapped) { |
| pehrhovey | 0:a548a085de55 | 375 | acc = SWAP_BYTES_IN_WORD(acc); |
| pehrhovey | 0:a548a085de55 | 376 | } |
| pehrhovey | 0:a548a085de55 | 377 | acc += (src->addr & 0xffffUL); |
| pehrhovey | 0:a548a085de55 | 378 | acc += ((src->addr >> 16) & 0xffffUL); |
| pehrhovey | 0:a548a085de55 | 379 | acc += (dest->addr & 0xffffUL); |
| pehrhovey | 0:a548a085de55 | 380 | acc += ((dest->addr >> 16) & 0xffffUL); |
| pehrhovey | 0:a548a085de55 | 381 | acc += (u32_t)htons((u16_t)proto); |
| pehrhovey | 0:a548a085de55 | 382 | acc += (u32_t)htons(proto_len); |
| pehrhovey | 0:a548a085de55 | 383 | |
| pehrhovey | 0:a548a085de55 | 384 | /* Fold 32-bit sum to 16 bits |
| pehrhovey | 0:a548a085de55 | 385 | calling this twice is propably faster than if statements... */ |
| pehrhovey | 0:a548a085de55 | 386 | acc = FOLD_U32T(acc); |
| pehrhovey | 0:a548a085de55 | 387 | acc = FOLD_U32T(acc); |
| pehrhovey | 0:a548a085de55 | 388 | LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): pbuf chain lwip_chksum()=%"X32_F"\n", acc)); |
| pehrhovey | 0:a548a085de55 | 389 | return (u16_t)~(acc & 0xffffUL); |
| pehrhovey | 0:a548a085de55 | 390 | } |
| pehrhovey | 0:a548a085de55 | 391 | #endif /* LWIP_UDPLITE */ |
| pehrhovey | 0:a548a085de55 | 392 | |
| pehrhovey | 0:a548a085de55 | 393 | /* inet_chksum: |
| pehrhovey | 0:a548a085de55 | 394 | * |
| pehrhovey | 0:a548a085de55 | 395 | * Calculates the Internet checksum over a portion of memory. Used primarily for IP |
| pehrhovey | 0:a548a085de55 | 396 | * and ICMP. |
| pehrhovey | 0:a548a085de55 | 397 | * |
| pehrhovey | 0:a548a085de55 | 398 | * @param dataptr start of the buffer to calculate the checksum (no alignment needed) |
| pehrhovey | 0:a548a085de55 | 399 | * @param len length of the buffer to calculate the checksum |
| pehrhovey | 0:a548a085de55 | 400 | * @return checksum (as u16_t) to be saved directly in the protocol header |
| pehrhovey | 0:a548a085de55 | 401 | */ |
| pehrhovey | 0:a548a085de55 | 402 | |
| pehrhovey | 0:a548a085de55 | 403 | u16_t |
| pehrhovey | 0:a548a085de55 | 404 | inet_chksum(void *dataptr, u16_t len) |
| pehrhovey | 0:a548a085de55 | 405 | { |
| pehrhovey | 0:a548a085de55 | 406 | return ~LWIP_CHKSUM(dataptr, len); |
| pehrhovey | 0:a548a085de55 | 407 | } |
| pehrhovey | 0:a548a085de55 | 408 | |
| pehrhovey | 0:a548a085de55 | 409 | /** |
| pehrhovey | 0:a548a085de55 | 410 | * Calculate a checksum over a chain of pbufs (without pseudo-header, much like |
| pehrhovey | 0:a548a085de55 | 411 | * inet_chksum only pbufs are used). |
| pehrhovey | 0:a548a085de55 | 412 | * |
| pehrhovey | 0:a548a085de55 | 413 | * @param p pbuf chain over that the checksum should be calculated |
| pehrhovey | 0:a548a085de55 | 414 | * @return checksum (as u16_t) to be saved directly in the protocol header |
| pehrhovey | 0:a548a085de55 | 415 | */ |
| pehrhovey | 0:a548a085de55 | 416 | u16_t |
| pehrhovey | 0:a548a085de55 | 417 | inet_chksum_pbuf(struct pbuf *p) |
| pehrhovey | 0:a548a085de55 | 418 | { |
| pehrhovey | 0:a548a085de55 | 419 | u32_t acc; |
| pehrhovey | 0:a548a085de55 | 420 | struct pbuf *q; |
| pehrhovey | 0:a548a085de55 | 421 | u8_t swapped; |
| pehrhovey | 0:a548a085de55 | 422 | |
| pehrhovey | 0:a548a085de55 | 423 | acc = 0; |
| pehrhovey | 0:a548a085de55 | 424 | swapped = 0; |
| pehrhovey | 0:a548a085de55 | 425 | for(q = p; q != NULL; q = q->next) { |
| pehrhovey | 0:a548a085de55 | 426 | acc += LWIP_CHKSUM(q->payload, q->len); |
| pehrhovey | 0:a548a085de55 | 427 | acc = FOLD_U32T(acc); |
| pehrhovey | 0:a548a085de55 | 428 | if (q->len % 2 != 0) { |
| pehrhovey | 0:a548a085de55 | 429 | swapped = 1 - swapped; |
| pehrhovey | 0:a548a085de55 | 430 | acc = SWAP_BYTES_IN_WORD(acc); |
| pehrhovey | 0:a548a085de55 | 431 | } |
| pehrhovey | 0:a548a085de55 | 432 | } |
| pehrhovey | 0:a548a085de55 | 433 | |
| pehrhovey | 0:a548a085de55 | 434 | if (swapped) { |
| pehrhovey | 0:a548a085de55 | 435 | acc = SWAP_BYTES_IN_WORD(acc); |
| pehrhovey | 0:a548a085de55 | 436 | } |
| pehrhovey | 0:a548a085de55 | 437 | return (u16_t)~(acc & 0xffffUL); |
| pehrhovey | 0:a548a085de55 | 438 | } |