/****************************************************************************
* net/uip/uip-chksum.c
*
* Copyright (C) 2007 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <spudmonkey@racsa.co.cr>
*
*
* 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. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "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
* COPYRIGHT OWNER OR CONTRIBUTORS 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.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#ifdef CONFIG_NET
#include <sys/types.h>
#include <debug.h>
#include <net/uip/uipopt.h>
#include <net/uip/uip.h>
#include <net/uip/uip-arch.h>
#include "uip-internal.h"
/****************************************************************************
* Definitions
****************************************************************************/
#define BUF ((struct uip_tcpip_hdr *)&dev->d_buf[UIP_LLH_LEN])
/****************************************************************************
* Private Data
****************************************************************************/
/****************************************************************************
* Private Functions
****************************************************************************/
#if !UIP_ARCH_CHKSUM
static uint16 chksum(uint16 sum, const uint8 *data, uint16 len)
{
uint16 t;
const uint8 *dataptr;
const uint8 *last_byte;
dataptr = data;
last_byte = data + len - 1;
while(dataptr < last_byte)
{
/* At least two more bytes */
t = (dataptr[0] << 8) + dataptr[1];
sum += t;
if (sum < t)
{
sum++; /* carry */
}
dataptr += 2;
}
if (dataptr == last_byte)
{
t = (dataptr[0] << 8) + 0;
sum += t;
if (sum < t)
{
sum++; /* carry */
}
}
/* Return sum in host byte order. */
return sum;
}
static uint16 upper_layer_chksum(struct uip_driver_s *dev, uint8 proto)
{
uint16 upper_layer_len;
uint16 sum;
#ifdef CONFIG_NET_IPv6
upper_layer_len = (((uint16)(BUF->len[0]) << 8) + BUF->len[1]);
#else /* CONFIG_NET_IPv6 */
upper_layer_len = (((uint16)(BUF->len[0]) << 8) + BUF->len[1]) - UIP_IPH_LEN;
#endif /* CONFIG_NET_IPv6 */
/* First sum pseudoheader. */
/* IP protocol and length fields. This addition cannot carry. */
sum = upper_layer_len + proto;
/* Sum IP source and destination addresses. */
sum = chksum(sum, (uint8 *)&BUF->srcipaddr, 2 * sizeof(uip_ipaddr_t));
/* Sum TCP header and data. */
sum = chksum(sum, &dev->d_buf[UIP_IPH_LEN + UIP_LLH_LEN], upper_layer_len);
return (sum == 0) ? 0xffff : htons(sum);
}
#ifdef CONFIG_NET_IPv6
static uint16 uip_icmp6chksum(struct uip_driver_s *dev)
{
return upper_layer_chksum(dev, UIP_PROTO_ICMP6);
}
#endif /* CONFIG_NET_IPv6 */
#endif /* UIP_ARCH_CHKSUM */
/****************************************************************************
* Public Functions
****************************************************************************/
/* Calculate the Internet checksum over a buffer. */
#if !UIP_ARCH_ADD32
static void uip_carry32(uint8 *sum, uint16 op16)
{
if (sum[2] < (op16 >> 8))
{
++sum[1];
if (sum[1] == 0)
{
++sum[0];
}
}
if (sum[3] < (op16 & 0xff))
{
++sum[2];
if (sum[2] == 0)
{
++sum[1];
if (sum[1] == 0)
{
++sum[0];
}
}
}
}
void uip_add32(const uint8 *op32, uint16 op16, uint8 *sum)
{
/* op32 and the sum are in network order (big-endian); op16 is host order. */
sum[3] = op32[3] + (op16 & 0xff);
sum[2] = op32[2] + (op16 >> 8);
sum[1] = op32[1];
sum[0] = op32[0];
uip_carry32(sum, op16);
}
void uip_incr32(uint8 *op32, uint16 op16)
{
op32[3] += (op16 & 0xff);
op32[2] += (op16 >> 8);
uip_carry32(op32, op16);
}
#endif /* UIP_ARCH_ADD32 */
#if !UIP_ARCH_CHKSUM
uint16 uip_chksum(uint16 *data, uint16 len)
{
return htons(chksum(0, (uint8 *)data, len));
}
/* Calculate the IP header checksum of the packet header in d_buf. */
#ifndef UIP_ARCH_IPCHKSUM
uint16 uip_ipchksum(struct uip_driver_s *dev)
{
uint16 sum;
sum = chksum(0, &dev->d_buf[UIP_LLH_LEN], UIP_IPH_LEN);
return (sum == 0) ? 0xffff : htons(sum);
}
#endif
/* Calculate the TCP checksum of the packet in d_buf and d_appdata. */
uint16 uip_tcpchksum(struct uip_driver_s *dev)
{
return upper_layer_chksum(dev, UIP_PROTO_TCP);
}
/* Calculate the UDP checksum of the packet in d_buf and d_appdata. */
#ifdef CONFIG_NET_UDP_CHECKSUMS
uint16 uip_udpchksum(struct uip_driver_s *dev)
{
return upper_layer_chksum(dev, UIP_PROTO_UDP);
}
#endif
#endif /* UIP_ARCH_CHKSUM */
#endif /* CONFIG_NET */
