351 lines
10 KiB
C
351 lines
10 KiB
C
/****************************************************************************
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* net/utils/net_chksum.c
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*
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* Copyright (C) 2007-2010, 2012, 2014 Gregory Nutt. All rights reserved.
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* Author: Gregory Nutt <gnutt@nuttx.org>
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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* 3. Neither the name NuttX nor the names of its contributors may be
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* used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
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* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
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* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*
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****************************************************************************/
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/****************************************************************************
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* Included Files
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****************************************************************************/
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#include <nuttx/config.h>
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#ifdef CONFIG_NET
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#include <stdint.h>
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#include <debug.h>
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#include <nuttx/net/netconfig.h>
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#include <nuttx/net/netdev.h>
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#include <nuttx/net/ip.h>
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#include <nuttx/net/icmp.h>
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#include "utils/utils.h"
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/****************************************************************************
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* Pre-processor Definitions
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****************************************************************************/
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#define BUF ((struct net_iphdr_s *)&dev->d_buf[NET_LL_HDRLEN])
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#define ICMPBUF ((struct icmp_iphdr_s *)&dev->d_buf[NET_LL_HDRLEN])
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/****************************************************************************
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* Private Data
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****************************************************************************/
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/****************************************************************************
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* Private Functions
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****************************************************************************/
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/****************************************************************************
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* Name: chksum
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****************************************************************************/
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#if !CONFIG_NET_ARCH_CHKSUM
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static uint16_t chksum(uint16_t sum, FAR const uint8_t *data, uint16_t len)
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{
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uint16_t t;
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const uint8_t *dataptr;
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const uint8_t *last_byte;
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dataptr = data;
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last_byte = data + len - 1;
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while (dataptr < last_byte)
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{
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/* At least two more bytes */
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t = (dataptr[0] << 8) + dataptr[1];
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sum += t;
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if (sum < t)
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{
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sum++; /* carry */
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}
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dataptr += 2;
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}
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if (dataptr == last_byte)
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{
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t = (dataptr[0] << 8) + 0;
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sum += t;
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if (sum < t)
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{
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sum++; /* carry */
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}
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}
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/* Return sum in host byte order. */
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return sum;
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}
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#endif /* CONFIG_NET_ARCH_CHKSUM */
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/****************************************************************************
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* Name: upper_layer_chksum
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****************************************************************************/
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#if !CONFIG_NET_ARCH_CHKSUM
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static uint16_t upper_layer_chksum(FAR struct net_driver_s *dev, uint8_t proto)
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{
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FAR struct net_iphdr_s *pbuf = BUF;
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uint16_t upper_layer_len;
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uint16_t sum;
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#ifdef CONFIG_NET_IPv6
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upper_layer_len = (((uint16_t)(pbuf->len[0]) << 8) + pbuf->len[1]);
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#else /* CONFIG_NET_IPv6 */
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upper_layer_len = (((uint16_t)(pbuf->len[0]) << 8) + pbuf->len[1]) - IP_HDRLEN;
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#endif /* CONFIG_NET_IPv6 */
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/* Verify some minimal assumptions */
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if (upper_layer_len > CONFIG_NET_BUFSIZE)
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{
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return 0;
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}
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/* First sum pseudo-header. */
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/* IP protocol and length fields. This addition cannot carry. */
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sum = upper_layer_len + proto;
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/* Sum IP source and destination addresses. */
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sum = chksum(sum, (uint8_t *)&pbuf->srcipaddr, 2 * sizeof(net_ipaddr_t));
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/* Sum TCP header and data. */
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sum = chksum(sum, &dev->d_buf[IP_HDRLEN + NET_LL_HDRLEN], upper_layer_len);
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return (sum == 0) ? 0xffff : htons(sum);
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}
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#endif /* CONFIG_NET_ARCH_CHKSUM */
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/****************************************************************************
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* Name: icmp_6chksum
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****************************************************************************/
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#if !CONFIG_NET_ARCH_CHKSUM
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#ifdef CONFIG_NET_IPv6
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static uint16_t icmp_6chksum(FAR struct net_driver_s *dev)
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{
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return upper_layer_chksum(dev, IP_PROTO_ICMP6);
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}
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#endif /* CONFIG_NET_IPv6 */
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#endif /* CONFIG_NET_ARCH_CHKSUM */
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/****************************************************************************
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* Name: net_carry32
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*
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* Description:
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* Calculate the Internet checksum over a buffer.
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*
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****************************************************************************/
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#if !CONFIG_NET_ARCH_INCR32
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static inline void net_carry32(FAR uint8_t *sum, uint16_t op16)
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{
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if (sum[2] < (op16 >> 8))
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{
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++sum[1];
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if (sum[1] == 0)
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{
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++sum[0];
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}
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}
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if (sum[3] < (op16 & 0xff))
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{
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++sum[2];
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if (sum[2] == 0)
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{
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++sum[1];
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if (sum[1] == 0)
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{
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++sum[0];
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}
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}
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}
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}
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#endif /* CONFIG_NET_ARCH_INCR32 */
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/****************************************************************************
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* Public Functions
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****************************************************************************/
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/****************************************************************************
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* Name: net_incr32
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*
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* Description:
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*
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* Carry out a 32-bit addition.
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*
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* By defining CONFIG_NET_ARCH_INCR32, the architecture can replace
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* net_incr32 with hardware assisted solutions.
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*
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* Input Parameters:
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* op32 - A pointer to a 4-byte array representing a 32-bit integer in
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* network byte order (big endian). This value may not be word
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* aligned. The value pointed to by op32 is modified in place
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*
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* op16 - A 16-bit integer in host byte order.
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*
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****************************************************************************/
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#if !CONFIG_NET_ARCH_INCR32
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void net_incr32(FAR uint8_t *op32, uint16_t op16)
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{
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op32[3] += (op16 & 0xff);
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op32[2] += (op16 >> 8);
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net_carry32(op32, op16);
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}
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#endif /* CONFIG_NET_ARCH_INCR32 */
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/****************************************************************************
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* Name: net_chksum
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*
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* Description:
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* Calculate the Internet checksum over a buffer.
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*
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* The Internet checksum is the one's complement of the one's complement
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* sum of all 16-bit words in the buffer.
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*
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* See RFC1071.
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*
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* If CONFIG_NET_ARCH_CHKSUM is defined, then this function must be
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* provided by architecture-specific logic.
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*
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* Input Parameters:
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*
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* buf - A pointer to the buffer over which the checksum is to be computed.
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*
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* len - The length of the buffer over which the checksum is to be computed.
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*
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* Returned Value:
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* The Internet checksum of the buffer.
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*
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****************************************************************************/
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#if !CONFIG_NET_ARCH_CHKSUM
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uint16_t net_chksum(FAR uint16_t *data, uint16_t len)
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{
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return htons(chksum(0, (uint8_t *)data, len));
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}
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#endif /* CONFIG_NET_ARCH_CHKSUM */
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/****************************************************************************
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* Name: ip_chksum
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*
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* Description:
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* Calculate the IP header checksum of the packet header in d_buf.
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*
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* The IP header checksum is the Internet checksum of the 20 bytes of
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* the IP header.
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*
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* If CONFIG_NET_ARCH_CHKSUM is defined, then this function must be
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* provided by architecture-specific logic.
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*
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* Returned Value:
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* The IP header checksum of the IP header in the d_buf buffer.
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*
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****************************************************************************/
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#if !CONFIG_NET_ARCH_CHKSUM
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uint16_t ip_chksum(FAR struct net_driver_s *dev)
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{
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uint16_t sum;
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sum = chksum(0, &dev->d_buf[NET_LL_HDRLEN], IP_HDRLEN);
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return (sum == 0) ? 0xffff : htons(sum);
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}
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#endif /* CONFIG_NET_ARCH_CHKSUM */
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/****************************************************************************
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* Name: tcp_chksum
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*
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* Description:
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* Calculate the TCP checksum of the packet in d_buf and d_appdata.
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*
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* The TCP checksum is the Internet checksum of data contents of the
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* TCP segment, and a pseudo-header as defined in RFC793.
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*
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* Note: The d_appdata pointer that points to the packet data may
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* point anywhere in memory, so it is not possible to simply calculate
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* the Internet checksum of the contents of the d_buf buffer.
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*
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* Returned Value:
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* The TCP checksum of the TCP segment in d_buf and pointed to by
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* d_appdata.
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*
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****************************************************************************/
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#if !CONFIG_NET_ARCH_CHKSUM
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uint16_t tcp_chksum(FAR struct net_driver_s *dev)
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{
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return upper_layer_chksum(dev, IP_PROTO_TCP);
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}
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#endif /* CONFIG_NET_ARCH_CHKSUM */
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/****************************************************************************
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* Name: udp_chksum
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*
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* Description:
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* Calculate the UDP checksum of the packet in d_buf and d_appdata.
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*
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****************************************************************************/
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#if defined(CONFIG_NET_UDP_CHECKSUMS) && !defined(CONFIG_NET_ARCH_CHKSUM)
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uint16_t udp_chksum(FAR struct net_driver_s *dev)
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{
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return upper_layer_chksum(dev, IP_PROTO_UDP);
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}
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#endif /* CONFIG_NET_UDP_CHECKSUMS && !CONFIG_NET_ARCH_CHKSUM */
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/****************************************************************************
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* Name: icmp_chksum
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*
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* Description:
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* Calculate the checksum of the ICMP message
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*
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****************************************************************************/
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#if defined(CONFIG_NET_ICMP) && defined(CONFIG_NET_ICMP_PING)
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uint16_t icmp_chksum(FAR struct net_driver_s *dev, int len)
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{
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FAR struct icmp_iphdr_s *picmp = ICMPBUF;
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return net_chksum((uint16_t*)&picmp->type, len);
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}
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#endif /* CONFIG_NET_ICMP && CONFIG_NET_ICMP_PING */
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#endif /* CONFIG_NET */
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