inet_chksum.h

00001 /**
00002  * @file
00003  * IP checksum calculation functions
00004  */
00005 
00006 /*
00007  * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
00008  * All rights reserved.
00009  *
00010  * Redistribution and use in source and binary forms, with or without modification,
00011  * are permitted provided that the following conditions are met:
00012  *
00013  * 1. Redistributions of source code must retain the above copyright notice,
00014  *    this list of conditions and the following disclaimer.
00015  * 2. Redistributions in binary form must reproduce the above copyright notice,
00016  *    this list of conditions and the following disclaimer in the documentation
00017  *    and/or other materials provided with the distribution.
00018  * 3. The name of the author may not be used to endorse or promote products
00019  *    derived from this software without specific prior written permission.
00020  *
00021  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
00022  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
00023  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
00024  * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
00025  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
00026  * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
00027  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
00028  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
00029  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
00030  * OF SUCH DAMAGE.
00031  *
00032  * This file is part of the lwIP TCP/IP stack.
00033  *
00034  * Author: Adam Dunkels <adam@sics.se>
00035  *
00036  */
00037 #ifndef LWIP_HDR_INET_CHKSUM_H
00038 #define LWIP_HDR_INET_CHKSUM_H
00039 
00040 #include "lwip/opt.h"
00041 
00042 #include "lwip/pbuf.h"
00043 #include "lwip/ip_addr.h"
00044 
00045 /** Swap the bytes in an u16_t: much like lwip_htons() for little-endian */
00046 #ifndef SWAP_BYTES_IN_WORD
00047 #define SWAP_BYTES_IN_WORD(w) (((w) & 0xff) << 8) | (((w) & 0xff00) >> 8)
00048 #endif /* SWAP_BYTES_IN_WORD */
00049 
00050 /** Split an u32_t in two u16_ts and add them up */
00051 #ifndef FOLD_U32T
00052 #define FOLD_U32T(u)          (((u) >> 16) + ((u) & 0x0000ffffUL))
00053 #endif
00054 
00055 #if LWIP_CHECKSUM_ON_COPY
00056 /** Function-like macro: same as MEMCPY but returns the checksum of copied data
00057     as u16_t */
00058 # ifndef LWIP_CHKSUM_COPY
00059 #  define LWIP_CHKSUM_COPY(dst, src, len) lwip_chksum_copy(dst, src, len)
00060 #  ifndef LWIP_CHKSUM_COPY_ALGORITHM
00061 #   define LWIP_CHKSUM_COPY_ALGORITHM 1
00062 #  endif /* LWIP_CHKSUM_COPY_ALGORITHM */
00063 # else /* LWIP_CHKSUM_COPY */
00064 #  define LWIP_CHKSUM_COPY_ALGORITHM 0
00065 # endif /* LWIP_CHKSUM_COPY */
00066 #else /* LWIP_CHECKSUM_ON_COPY */
00067 # define LWIP_CHKSUM_COPY_ALGORITHM 0
00068 #endif /* LWIP_CHECKSUM_ON_COPY */
00069 
00070 #ifdef __cplusplus
00071 extern "C" {
00072 #endif
00073 
00074 u16_t inet_chksum(const void *dataptr, u16_t len);
00075 u16_t inet_chksum_pbuf(struct pbuf *p);
00076 #if LWIP_CHKSUM_COPY_ALGORITHM
00077 u16_t lwip_chksum_copy(void *dst, const void *src, u16_t len);
00078 #endif /* LWIP_CHKSUM_COPY_ALGORITHM */
00079 
00080 #if LWIP_IPV4
00081 u16_t inet_chksum_pseudo(struct pbuf *p, u8_t proto, u16_t proto_len,
00082        const ip4_addr_t *src, const ip4_addr_t *dest);
00083 u16_t inet_chksum_pseudo_partial(struct pbuf *p, u8_t proto,
00084        u16_t proto_len, u16_t chksum_len, const ip4_addr_t *src, const ip4_addr_t *dest);
00085 #endif /* LWIP_IPV4 */
00086 
00087 #if LWIP_IPV6
00088 u16_t ip6_chksum_pseudo(struct pbuf *p, u8_t proto, u16_t proto_len,
00089        const ip6_addr_t *src, const ip6_addr_t *dest);
00090 u16_t ip6_chksum_pseudo_partial(struct pbuf *p, u8_t proto, u16_t proto_len,
00091        u16_t chksum_len, const ip6_addr_t *src, const ip6_addr_t *dest);
00092 #endif /* LWIP_IPV6 */
00093 
00094 
00095 u16_t ip_chksum_pseudo(struct pbuf *p, u8_t proto, u16_t proto_len,
00096        const ip_addr_t *src, const ip_addr_t *dest);
00097 u16_t ip_chksum_pseudo_partial(struct pbuf *p, u8_t proto, u16_t proto_len,
00098        u16_t chksum_len, const ip_addr_t *src, const ip_addr_t *dest);
00099 
00100 #ifdef __cplusplus
00101 }
00102 #endif
00103 
00104 #endif /* LWIP_HDR_INET_H */
00105