inet_chksum.h

00001 /*
00002  * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
00003  * All rights reserved. 
00004  * 
00005  * Redistribution and use in source and binary forms, with or without modification, 
00006  * are permitted provided that the following conditions are met:
00007  *
00008  * 1. Redistributions of source code must retain the above copyright notice,
00009  *    this list of conditions and the following disclaimer.
00010  * 2. Redistributions in binary form must reproduce the above copyright notice,
00011  *    this list of conditions and the following disclaimer in the documentation
00012  *    and/or other materials provided with the distribution.
00013  * 3. The name of the author may not be used to endorse or promote products
00014  *    derived from this software without specific prior written permission. 
00015  *
00016  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED 
00017  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 
00018  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT 
00019  * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 
00020  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT 
00021  * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
00022  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 
00023  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 
00024  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY 
00025  * OF SUCH DAMAGE.
00026  *
00027  * This file is part of the lwIP TCP/IP stack.
00028  * 
00029  * Author: Adam Dunkels <adam@sics.se>
00030  *
00031  */
00032 #ifndef __LWIP_INET_CHKSUM_H__
00033 #define __LWIP_INET_CHKSUM_H__
00034 
00035 #include "lwip/opt.h"
00036 
00037 #include "lwip/pbuf.h"
00038 #include "lwip/ip_addr.h"
00039 
00040 /** Swap the bytes in an u16_t: much like htons() for little-endian */
00041 #ifndef SWAP_BYTES_IN_WORD
00042 #if LWIP_PLATFORM_BYTESWAP && (BYTE_ORDER == LITTLE_ENDIAN)
00043 /* little endian and PLATFORM_BYTESWAP defined */
00044 #define SWAP_BYTES_IN_WORD(w) LWIP_PLATFORM_HTONS(w)
00045 #else /* LWIP_PLATFORM_BYTESWAP && (BYTE_ORDER == LITTLE_ENDIAN) */
00046 /* can't use htons on big endian (or PLATFORM_BYTESWAP not defined)... */
00047 #define SWAP_BYTES_IN_WORD(w) (((w) & 0xff) << 8) | (((w) & 0xff00) >> 8)
00048 #endif /* LWIP_PLATFORM_BYTESWAP && (BYTE_ORDER == LITTLE_ENDIAN)*/
00049 #endif /* SWAP_BYTES_IN_WORD */
00050 
00051 /** Split an u32_t in two u16_ts and add them up */
00052 #ifndef FOLD_U32T
00053 #define FOLD_U32T(u)          (((u) >> 16) + ((u) & 0x0000ffffUL))
00054 #endif
00055 
00056 #if LWIP_CHECKSUM_ON_COPY
00057 /** Function-like macro: same as MEMCPY but returns the checksum of copied data
00058     as u16_t */
00059 #ifndef LWIP_CHKSUM_COPY
00060 #define LWIP_CHKSUM_COPY(dst, src, len) lwip_chksum_copy(dst, src, len)
00061 #ifndef LWIP_CHKSUM_COPY_ALGORITHM
00062 #define LWIP_CHKSUM_COPY_ALGORITHM 1
00063 #endif /* LWIP_CHKSUM_COPY_ALGORITHM */
00064 #endif /* LWIP_CHKSUM_COPY */
00065 #else /* LWIP_CHECKSUM_ON_COPY */
00066 #define LWIP_CHKSUM_COPY_ALGORITHM 0
00067 #endif /* LWIP_CHECKSUM_ON_COPY */
00068 
00069 #ifdef __cplusplus
00070 extern "C" {
00071 #endif
00072 
00073 u16_t inet_chksum(void *dataptr, u16_t len);
00074 u16_t inet_chksum_pbuf(struct pbuf *p);
00075 u16_t inet_chksum_pseudo(struct pbuf *p,
00076        ip_addr_t *src, ip_addr_t *dest,
00077        u8_t proto, u16_t proto_len);
00078 u16_t inet_chksum_pseudo_partial(struct pbuf *p,
00079        ip_addr_t *src, ip_addr_t *dest,
00080        u8_t proto, u16_t proto_len, u16_t chksum_len);
00081 #if LWIP_CHKSUM_COPY_ALGORITHM
00082 u16_t lwip_chksum_copy(void *dst, const void *src, u16_t len);
00083 #endif /* LWIP_CHKSUM_COPY_ALGORITHM */
00084 
00085 #ifdef __cplusplus
00086 }
00087 #endif
00088 
00089 #endif /* __LWIP_INET_H__ */
00090