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- /****************************************************************************
- * net/utils/net_incr32.c
- *
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements. See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership. The
- * ASF licenses this file to you under the Apache License, Version 2.0 (the
- * "License"); you may not use this file except in compliance with the
- * License. You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
- * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
- * License for the specific language governing permissions and limitations
- * under the License.
- *
- ****************************************************************************/
- /****************************************************************************
- * Included Files
- ****************************************************************************/
- #include <nuttx/config.h>
- #include <nuttx/net/netdev.h>
- #ifndef CONFIG_NET_ARCH_INCR32
- /****************************************************************************
- * Private Functions
- ****************************************************************************/
- /****************************************************************************
- * Name: net_carry32
- *
- * Description:
- * Calculate the Internet checksum over a buffer.
- *
- ****************************************************************************/
- static inline void net_carry32(FAR uint8_t *sum, uint16_t 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];
- }
- }
- }
- }
- /****************************************************************************
- * Public Functions
- ****************************************************************************/
- /****************************************************************************
- * Name: net_incr32
- *
- * Description:
- *
- * Carry out a 32-bit addition.
- *
- * By defining CONFIG_NET_ARCH_INCR32, the architecture can replace
- * net_incr32 with hardware assisted solutions.
- *
- * Input Parameters:
- * op32 - A pointer to a 4-byte array representing a 32-bit integer in
- * network byte order (big endian). This value may not be word
- * aligned. The value pointed to by op32 is modified in place
- *
- * op16 - A 16-bit integer in host byte order.
- *
- ****************************************************************************/
- void net_incr32(FAR uint8_t *op32, uint16_t op16)
- {
- op32[3] += (op16 & 0xff);
- op32[2] += (op16 >> 8);
- net_carry32(op32, op16);
- }
- #endif /* CONFIG_NET_ARCH_INCR32 */
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