rt-thread-official/components/net/uip/rt-thread/uip_arch.c

144 lines
4.0 KiB
C

/*
* Copyright (c) 2001, Adam Dunkels.
* 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 uIP TCP/IP stack.
*
* $Id: uip_arch.c,v 1.2.2.1 2003/10/04 22:54:17 adam Exp $
*
*/
#include "uip.h"
#include "uip_arch.h"
#define BUF ((struct uip_tcpip_hdr *)&uip_buf[UIP_LLH_LEN])
#define IP_PROTO_TCP 6
/*-----------------------------------------------------------------------------------*/
void uip_add32(u8_t *op32, u16_t op16)
{
uip_acc32[3] = op32[3] + (op16 & 0xff);
uip_acc32[2] = op32[2] + (op16 >> 8);
uip_acc32[1] = op32[1];
uip_acc32[0] = op32[0];
if(uip_acc32[2] < (op16 >> 8)) {
++uip_acc32[1];
if(uip_acc32[1] == 0) {
++uip_acc32[0];
}
}
if(uip_acc32[3] < (op16 & 0xff)) {
++uip_acc32[2];
if(uip_acc32[2] == 0) {
++uip_acc32[1];
if(uip_acc32[1] == 0) {
++uip_acc32[0];
}
}
}
}
/*-----------------------------------------------------------------------------------*/
u16_t uip_chksum(u16_t *sdata, u16_t len)
{
u16_t acc;
for (acc = 0; len > 1; len -= 2) {
u16_t u = ((unsigned char *)sdata)[0] + (((unsigned char *)sdata)[1] << 8);
if ((acc += u) < u) {
/* Overflow, so we add the carry to acc (i.e., increase by
one). */
++acc;
}
++sdata;
}
/* add up any odd byte */
if(len == 1) {
acc += htons(((u16_t)(*(u8_t *)sdata)) << 8);
if(acc < htons(((u16_t)(*(u8_t *)sdata)) << 8)) {
++acc;
}
}
return acc;
}
/*-----------------------------------------------------------------------------------*/
u16_t uip_ipchksum(void)
{
return uip_chksum((u16_t *)&uip_buf[UIP_LLH_LEN], 20);
}
/*-----------------------------------------------------------------------------------*/
u16_t uip_tcpchksum(void)
{
u16_t hsum, sum;
/* Compute the checksum of the TCP header. */
hsum = uip_chksum((u16_t *)&uip_buf[20 + UIP_LLH_LEN], 20);
/* Compute the checksum of the data in the TCP packet and add it to
the TCP header checksum. */
sum = uip_chksum((u16_t *)uip_appdata,
(u16_t)(((((u16_t)(BUF->len[0]) << 8) + BUF->len[1]) - 40)));
if((sum += hsum) < hsum) {
++sum;
}
if((sum += BUF->srcipaddr[0]) < BUF->srcipaddr[0]) {
++sum;
}
if((sum += BUF->srcipaddr[1]) < BUF->srcipaddr[1]) {
++sum;
}
if((sum += BUF->destipaddr[0]) < BUF->destipaddr[0]) {
++sum;
}
if((sum += BUF->destipaddr[1]) < BUF->destipaddr[1]) {
++sum;
}
if((sum += (u16_t)htons((u16_t)IP_PROTO_TCP)) < (u16_t)htons((u16_t)IP_PROTO_TCP)) {
++sum;
}
hsum = (u16_t)htons((((u16_t)(BUF->len[0]) << 8) + BUF->len[1]) - 20);
if((sum += hsum) < hsum) {
++sum;
}
return sum;
}