| /* |
| * Copyright (c) 2001-2003 Swedish Institute of Computer Science. |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without modification, |
| * are permitted provided that the following conditions are met: |
| * |
| * 1. Redistributions of source code must retain the above copyright notice, |
| * this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright notice, |
| * this list of conditions and the following disclaimer in the documentation |
| * and/or other materials provided with the distribution. |
| * 3. The name of the author may not be used to endorse or promote products |
| * derived from this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED |
| * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF |
| * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT |
| * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, |
| * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT |
| * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING |
| * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY |
| * OF SUCH DAMAGE. |
| * |
| * This file is part of the lwIP TCP/IP stack. |
| * |
| * Author: Adam Dunkels <adam@sics.se> |
| * |
| */ |
| |
| #include "lwip/debug.h" |
| |
| #include "lwip/arch.h" |
| |
| #include "lwip/def.h" |
| #include "lwip/inet.h" |
| |
| |
| /*-----------------------------------------------------------------------------------*/ |
| /* lwip_chksum: |
| * |
| * Sums up all 16 bit words in a memory portion. Also includes any odd byte. |
| * This function is used by the other checksum functions. |
| * |
| */ |
| /*-----------------------------------------------------------------------------------*/ |
| #if 0 |
| u16_t |
| lwip_chksum(void *dataptr, int len) |
| { |
| u32_t acc; |
| |
| for(acc = 0; len > 1; len -= 2) { |
| acc += *((u16_t *)dataptr)++; |
| } |
| |
| /* add up any odd byte */ |
| if(len == 1) { |
| acc += htons((u16_t)((*(u8_t *)dataptr) & 0xff) << 8); |
| DEBUGF(INET_DEBUG, ("inet: chksum: odd byte %d\n", *(u8_t *)dataptr)); |
| } |
| acc = (acc >> 16) + (acc & 0xffffUL); |
| |
| if(acc & 0xffff0000 != 0) { |
| acc = (acc >> 16) + (acc & 0xffffUL); |
| } |
| |
| return (u16_t)acc; |
| } |
| /*-----------------------------------------------------------------------------------*/ |
| #endif |