incubator-nuttx/net/utils/net_ipchksum.c

200 lines
6.7 KiB
C

/****************************************************************************
* net/utils/net_ipchksum.c
*
* Copyright (C) 2007-2010, 2012, 2014-2015, 2017 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* 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>
#include <stdint.h>
#include <nuttx/net/netconfig.h>
#include <nuttx/net/netdev.h>
#include <nuttx/net/ip.h>
#include "utils/utils.h"
#ifdef CONFIG_NET
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#define IPv4BUF ((struct ipv4_hdr_s *)&dev->d_buf[NET_LL_HDRLEN(dev)])
#define IPv6BUF ((struct ipv6_hdr_s *)&dev->d_buf[NET_LL_HDRLEN(dev)])
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: ipv4_upperlayer_chksum
*
* Description:
* Perform the checksum calcaultion over the IPv4, protocol headers, and
* data payload as necessary.
*
* Input Parameters:
* dev - The network driver instance. The packet data is in the d_buf
* of the device.
* proto - The protocol being supported
*
* Returned Value:
* The calculated checksum
*
****************************************************************************/
#if !defined(CONFIG_NET_ARCH_CHKSUM) && defined(CONFIG_NET_IPv4)
uint16_t ipv4_upperlayer_chksum(FAR struct net_driver_s *dev, uint8_t proto)
{
FAR struct ipv4_hdr_s *ipv4 = IPv4BUF;
uint16_t upperlen;
uint16_t sum;
/* The length reported in the IPv4 header is the length of both the IPv4
* header and the payload that follows the header. We need to subtract
* the size of the IPv4 header to get the size of the payload.
*/
upperlen = (((uint16_t)(ipv4->len[0]) << 8) + ipv4->len[1]) - IPv4_HDRLEN;
/* Verify some minimal assumptions */
if (upperlen > NET_DEV_MTU(dev))
{
return 0;
}
/* First sum pseudo-header. */
/* IP protocol and length fields. This addition cannot carry. */
sum = upperlen + proto;
/* Sum IP source and destination addresses. */
sum = chksum(sum, (FAR uint8_t *)&ipv4->srcipaddr, 2 * sizeof(in_addr_t));
/* Sum IP payload data. */
sum = chksum(sum, &dev->d_buf[IPv4_HDRLEN + NET_LL_HDRLEN(dev)], upperlen);
return (sum == 0) ? 0xffff : htons(sum);
}
#endif /* CONFIG_NET_ARCH_CHKSUM */
/****************************************************************************
* Name: ipv6_upperlayer_chksum
*
* Description:
* Perform the checksum calculation over the IPv6, protocol headers, and
* data payload as necessary.
*
* Input Parameters:
* dev - The network driver instance. The packet data is in the d_buf
* of the device.
* proto - The protocol being supported
*
* Returned Value:
* The calculated checksum
*
****************************************************************************/
#if !defined(CONFIG_NET_ARCH_CHKSUM) && defined(CONFIG_NET_IPv6)
uint16_t ipv6_upperlayer_chksum(FAR struct net_driver_s *dev, uint8_t proto)
{
FAR struct ipv6_hdr_s *ipv6 = IPv6BUF;
uint16_t upperlen;
uint16_t sum;
/* The length reported in the IPv6 header is the length of the payload
* that follows the header.
*/
upperlen = ((uint16_t)ipv6->len[0] << 8) + ipv6->len[1];
/* Verify some minimal assumptions */
if (upperlen > NET_DEV_MTU(dev))
{
return 0;
}
/* The checksum is calculated starting with a pseudo-header of IPv6 header
* fields according to the IPv6 standard, which consists of the source
* and destination addresses, the packet length and the next header field.
*/
sum = upperlen + proto;
/* Sum IP source and destination addresses. */
sum = chksum(sum, (FAR uint8_t *)&ipv6->srcipaddr, 2 * sizeof(net_ipv6addr_t));
/* Sum IP payload data. */
sum = chksum(sum, &dev->d_buf[IPv6_HDRLEN + NET_LL_HDRLEN(dev)], upperlen);
return (sum == 0) ? 0xffff : htons(sum);
}
#endif /* CONFIG_NET_ARCH_CHKSUM */
/****************************************************************************
* Name: ipv4_chksum
*
* Description:
* Calculate the IPv4 header checksum of the packet header in d_buf.
*
* The IPv4 header checksum is the Internet checksum of the 20 bytes of
* the IPv4 header.
*
* If CONFIG_NET_ARCH_CHKSUM is defined, then this function must be
* provided by architecture-specific logic.
*
* Returned Value:
* The IPv4 header checksum of the IPv4 header in the d_buf buffer.
*
****************************************************************************/
#if defined(CONFIG_NET_IPv4) && !defined(CONFIG_NET_ARCH_CHKSUM)
uint16_t ipv4_chksum(FAR struct net_driver_s *dev)
{
uint16_t sum;
sum = chksum(0, &dev->d_buf[NET_LL_HDRLEN(dev)], IPv4_HDRLEN);
return (sum == 0) ? 0xffff : htons(sum);
}
#endif /* CONFIG_NET_ARCH_CHKSUM */
#endif /* CONFIG_NET */