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Diff: core/def.c
- Revision:
- 0:51ac1d130fd4
diff -r 000000000000 -r 51ac1d130fd4 core/def.c --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/core/def.c Fri Jun 22 09:25:39 2012 +0000 @@ -0,0 +1,108 @@ +/** + * @file + * Common functions used throughout the stack. + * + */ + +/* + * Copyright (c) 2001-2004 Swedish Institute of Computer Science. + * 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. 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 lwIP TCP/IP stack. + * + * Author: Simon Goldschmidt + * + */ + +#include "lwip/opt.h" +#include "lwip/def.h" + +/** + * These are reference implementations of the byte swapping functions. + * Again with the aim of being simple, correct and fully portable. + * Byte swapping is the second thing you would want to optimize. You will + * need to port it to your architecture and in your cc.h: + * + * #define LWIP_PLATFORM_BYTESWAP 1 + * #define LWIP_PLATFORM_HTONS(x) <your_htons> + * #define LWIP_PLATFORM_HTONL(x) <your_htonl> + * + * Note ntohs() and ntohl() are merely references to the htonx counterparts. + */ + +#if (LWIP_PLATFORM_BYTESWAP == 0) && (BYTE_ORDER == LITTLE_ENDIAN) + +/** + * Convert an u16_t from host- to network byte order. + * + * @param n u16_t in host byte order + * @return n in network byte order + */ +u16_t +lwip_htons(u16_t n) +{ + return ((n & 0xff) << 8) | ((n & 0xff00) >> 8); +} + +/** + * Convert an u16_t from network- to host byte order. + * + * @param n u16_t in network byte order + * @return n in host byte order + */ +u16_t +lwip_ntohs(u16_t n) +{ + return lwip_htons(n); +} + +/** + * Convert an u32_t from host- to network byte order. + * + * @param n u32_t in host byte order + * @return n in network byte order + */ +u32_t +lwip_htonl(u32_t n) +{ + return ((n & 0xff) << 24) | + ((n & 0xff00) << 8) | + ((n & 0xff0000UL) >> 8) | + ((n & 0xff000000UL) >> 24); +} + +/** + * Convert an u32_t from network- to host byte order. + * + * @param n u32_t in network byte order + * @return n in host byte order + */ +u32_t +lwip_ntohl(u32_t n) +{ + return lwip_htonl(n); +} + +#endif /* (LWIP_PLATFORM_BYTESWAP == 0) && (BYTE_ORDER == LITTLE_ENDIAN) */