1 /** 2 * @file 3 * IP checksum calculation functions 4 */ 5 6 /* 7 * Copyright (c) 2001-2004 Swedish Institute of Computer Science. 8 * All rights reserved. 9 * 10 * Redistribution and use in source and binary forms, with or without modification, 11 * are permitted provided that the following conditions are met: 12 * 13 * 1. Redistributions of source code must retain the above copyright notice, 14 * this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright notice, 16 * this list of conditions and the following disclaimer in the documentation 17 * and/or other materials provided with the distribution. 18 * 3. The name of the author may not be used to endorse or promote products 19 * derived from this software without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED 22 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 23 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT 24 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 25 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT 26 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 29 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY 30 * OF SUCH DAMAGE. 31 * 32 * This file is part of the lwIP TCP/IP stack. 33 * 34 * Author: Adam Dunkels <adam@sics.se> 35 * 36 */ 37 #ifndef LWIP_HDR_INET_CHKSUM_H 38 #define LWIP_HDR_INET_CHKSUM_H 39 40 #include "lwip/opt.h" 41 42 #include "lwip/pbuf.h" 43 #include "lwip/ip_addr.h" 44 45 /** Swap the bytes in an u16_t: much like lwip_htons() for little-endian */ 46 #ifndef SWAP_BYTES_IN_WORD 47 #define SWAP_BYTES_IN_WORD(w) (((w) & 0xff) << 8) | (((w) & 0xff00) >> 8) 48 #endif /* SWAP_BYTES_IN_WORD */ 49 50 /** Split an u32_t in two u16_ts and add them up */ 51 #ifndef FOLD_U32T 52 #define FOLD_U32T(u) ((u32_t)(((u) >> 16) + ((u) & 0x0000ffffUL))) 53 #endif 54 55 #if LWIP_CHECKSUM_ON_COPY 56 /** Function-like macro: same as MEMCPY but returns the checksum of copied data 57 as u16_t */ 58 # ifndef LWIP_CHKSUM_COPY 59 # define LWIP_CHKSUM_COPY(dst, src, len) lwip_chksum_copy(dst, src, len) 60 # ifndef LWIP_CHKSUM_COPY_ALGORITHM 61 # define LWIP_CHKSUM_COPY_ALGORITHM 1 62 # endif /* LWIP_CHKSUM_COPY_ALGORITHM */ 63 # else /* LWIP_CHKSUM_COPY */ 64 # define LWIP_CHKSUM_COPY_ALGORITHM 0 65 # endif /* LWIP_CHKSUM_COPY */ 66 #else /* LWIP_CHECKSUM_ON_COPY */ 67 # define LWIP_CHKSUM_COPY_ALGORITHM 0 68 #endif /* LWIP_CHECKSUM_ON_COPY */ 69 70 #ifdef __cplusplus 71 extern "C" { 72 #endif 73 74 u16_t inet_chksum(const void *dataptr, u16_t len); 75 u16_t inet_chksum_pbuf(struct pbuf *p); 76 #if LWIP_CHKSUM_COPY_ALGORITHM 77 u16_t lwip_chksum_copy(void *dst, const void *src, u16_t len); 78 #endif /* LWIP_CHKSUM_COPY_ALGORITHM */ 79 80 #if LWIP_IPV4 81 u16_t inet_chksum_pseudo(struct pbuf *p, u8_t proto, u16_t proto_len, 82 const ip4_addr_t *src, const ip4_addr_t *dest); 83 u16_t inet_chksum_pseudo_partial(struct pbuf *p, u8_t proto, 84 u16_t proto_len, u16_t chksum_len, const ip4_addr_t *src, const ip4_addr_t *dest); 85 #endif /* LWIP_IPV4 */ 86 87 #if LWIP_IPV6 88 u16_t ip6_chksum_pseudo(struct pbuf *p, u8_t proto, u16_t proto_len, 89 const ip6_addr_t *src, const ip6_addr_t *dest); 90 u16_t ip6_chksum_pseudo_partial(struct pbuf *p, u8_t proto, u16_t proto_len, 91 u16_t chksum_len, const ip6_addr_t *src, const ip6_addr_t *dest); 92 #endif /* LWIP_IPV6 */ 93 94 95 u16_t ip_chksum_pseudo(struct pbuf *p, u8_t proto, u16_t proto_len, 96 const ip_addr_t *src, const ip_addr_t *dest); 97 u16_t ip_chksum_pseudo_partial(struct pbuf *p, u8_t proto, u16_t proto_len, 98 u16_t chksum_len, const ip_addr_t *src, const ip_addr_t *dest); 99 100 #ifdef __cplusplus 101 } 102 #endif 103 104 #endif /* LWIP_HDR_INET_H */ 105