uip_arch.c

8051的WEB服务器

/*
 * 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by Adam Dunkels.
 * 4. 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 1.1.1.1 2002/04/02 01:22:54 felipe Exp $
 *
 */

#include "uip.h"
#include "uip_arch.h"

uip_tcpip_hdr * TCPBUF;
#define IP_PROTO_TCP    6


/*-----------------------------------------------------------------------------------*/
#if UIP_BUFSIZE >= 256
/*-----------------------------------------------------------------------------------*/
void
uip_add_rcv_nxt(u16_t n)
{
  uip_conn->rcv_nxt[3] += (n & 0xff);
  uip_conn->rcv_nxt[2] += (n >> 8);

  if(uip_conn->rcv_nxt[2] < (n >> 8)) {
    ++uip_conn->rcv_nxt[1];
    if(uip_conn->rcv_nxt[1] == 0) {
      ++uip_conn->rcv_nxt[0];
    }
  }


  if(uip_conn->rcv_nxt[3] < (n & 0xff)) {
    ++uip_conn->rcv_nxt[2];
    if(uip_conn->rcv_nxt[2] == 0) {
      ++uip_conn->rcv_nxt[1];
      if(uip_conn->rcv_nxt[1] == 0) {
	++uip_conn->rcv_nxt[0];
      }
    }
  }
}
/*-----------------------------------------------------------------------------------*/
void
uip_add_ack_nxt(u16_t n)
{
  uip_conn->ack_nxt[3] += (n & 0xff);
  uip_conn->ack_nxt[2] += (n >> 8);

  if(uip_conn->ack_nxt[2] < (n >> 8)) {
    ++uip_conn->ack_nxt[1];
    if(uip_conn->ack_nxt[1] == 0) {
      ++uip_conn->ack_nxt[0];
    }
  }


  if(uip_conn->ack_nxt[3] < (n & 0xff)) {
    ++uip_conn->ack_nxt[2];
    if(uip_conn->ack_nxt[2] == 0) {
      ++uip_conn->ack_nxt[1];
      if(uip_conn->ack_nxt[1] == 0) {
	++uip_conn->ack_nxt[0];
      }
    }
  }
}
/*-----------------------------------------------------------------------------------*/
#else /* UIP_BUFSIZE >= 256 */
/*-----------------------------------------------------------------------------------*/
void
uip_add_rcv_nxt(u8_t n)
{
  uip_conn->rcv_nxt[3] += n;
  if(uip_conn->rcv_nxt[3] < n) {
    ++uip_conn->rcv_nxt[2];
    if(uip_conn->rcv_nxt[2] == 0) {
      ++uip_conn->rcv_nxt[1];
      if(uip_conn->rcv_nxt[1] == 0) {
	++uip_conn->rcv_nxt[0];
      }
    }
  }
}
/*-----------------------------------------------------------------------------------*/
void
uip_add_ack_nxt(u8_t n)
{
  uip_conn->ack_nxt[3] += n;
  if(uip_conn->ack_nxt[3] < n) {
    ++uip_conn->ack_nxt[2];
    if(uip_conn->ack_nxt[2] == 0) {
      ++uip_conn->ack_nxt[1];
      if(uip_conn->ack_nxt[1] == 0) {
	++uip_conn->ack_nxt[0];
      }
    }
  }
}
/*-----------------------------------------------------------------------------------*/
#endif /* UIP_BUFSIZE >= 256 */
static u16_t
chksum(u16_t *sdata, u16_t len)
{
  u16_t acc;

  for(acc = 0; len > 1; len -= 2) {
    acc += *sdata;
    if(acc < *sdata) {
      /* 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 chksum((u16_t *)&uip_buf[UIP_LLH_LEN], 20);
}
/*-----------------------------------------------------------------------------------*/
u16_t
uip_tcpchksum(void)
{
  u16_t hsum, sum;

  TCPBUF = &uip_buf[UIP_LLH_LEN];

  /* Compute the checksum of the TCP header. */
  hsum = 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 = chksum((u16_t *)uip_appdata,
	       (u16_t)(((((u16_t)(TCPBUF->len[0]) << 8) + TCPBUF->len[1]) - 40)));

  if((sum += hsum) < hsum) {
    ++sum;
  }

  if((sum += TCPBUF->srcipaddr[0]) < TCPBUF->srcipaddr[0]) {
    ++sum;
  }
  if((sum += TCPBUF->srcipaddr[1]) < TCPBUF->srcipaddr[1]) {
    ++sum;
  }
  if((sum += TCPBUF->destipaddr[0]) < TCPBUF->destipaddr[0]) {
    ++sum;
  }
  if((sum += TCPBUF->destipaddr[1]) < TCPBUF->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)(TCPBUF->len[0]) << 8) + TCPBUF->len[1]) - 20);

  if((sum += hsum) < hsum) {
    ++sum;
  }

  return sum;
}
/*-----------------------------------------------------------------------------------*/