uip_arch.h

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00001 /**
00002  * \addtogroup uip
00003  * {@
00004  */
00005 
00006 /**
00007  * \defgroup uiparch Architecture specific uIP functions
00008  * @{
00009  *
00010  * The functions in the architecture specific module implement the IP
00011  * check sum and 32-bit additions.
00012  *
00013  * The IP checksum calculation is the most computationally expensive
00014  * operation in the TCP/IP stack and it therefore pays off to
00015  * implement this in efficient assembler. The purpose of the uip-arch
00016  * module is to let the checksum functions to be implemented in
00017  * architecture specific assembler.
00018  *
00019  */
00020 
00021 /**
00022  * \file
00023  * Declarations of architecture specific functions.
00024  * \author Adam Dunkels <adam@dunkels.com>
00025  */
00026 
00027 /*
00028  * Copyright (c) 2001, Adam Dunkels.
00029  * All rights reserved. 
00030  *
00031  * Redistribution and use in source and binary forms, with or without 
00032  * modification, are permitted provided that the following conditions 
00033  * are met: 
00034  * 1. Redistributions of source code must retain the above copyright 
00035  *    notice, this list of conditions and the following disclaimer. 
00036  * 2. Redistributions in binary form must reproduce the above copyright 
00037  *    notice, this list of conditions and the following disclaimer in the 
00038  *    documentation and/or other materials provided with the distribution. 
00039  * 3. The name of the author may not be used to endorse or promote
00040  *    products derived from this software without specific prior
00041  *    written permission.  
00042  *
00043  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
00044  * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
00045  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
00046  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
00047  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
00048  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
00049  * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
00050  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
00051  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
00052  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
00053  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.  
00054  *
00055  * This file is part of the uIP TCP/IP stack.
00056  *
00057  * $Id: uip_arch.h,v 1.1 2006/06/17 22:41:19 adamdunkels Exp $
00058  *
00059  */
00060 
00061 #ifndef __UIP_ARCH_H__
00062 #define __UIP_ARCH_H__
00063 
00064 #include "net/uip.h"
00065 
00066 /**
00067  * Carry out a 32-bit addition.
00068  *
00069  * Because not all architectures for which uIP is intended has native
00070  * 32-bit arithmetic, uIP uses an external C function for doing the
00071  * required 32-bit additions in the TCP protocol processing. This
00072  * function should add the two arguments and place the result in the
00073  * global variable uip_acc32.
00074  *
00075  * \note The 32-bit integer pointed to by the op32 parameter and the
00076  * result in the uip_acc32 variable are in network byte order (big
00077  * endian).
00078  *
00079  * \param op32 A pointer to a 4-byte array representing a 32-bit
00080  * integer in network byte order (big endian).
00081  *
00082  * \param op16 A 16-bit integer in host byte order.
00083  */
00084 void uip_add32(u8_t *op32, u16_t op16);
00085 
00086 /**
00087  * Calculate the Internet checksum over a buffer.
00088  *
00089  * The Internet checksum is the one's complement of the one's
00090  * complement sum of all 16-bit words in the buffer.
00091  *
00092  * See RFC1071.
00093  *
00094  * \note This function is not called in the current version of uIP,
00095  * but future versions might make use of it.
00096  *
00097  * \param buf A pointer to the buffer over which the checksum is to be
00098  * computed.
00099  *
00100  * \param len The length of the buffer over which the checksum is to
00101  * be computed.
00102  *
00103  * \return The Internet checksum of the buffer.
00104  */
00105 u16_t uip_chksum(u16_t *buf, u16_t len);
00106 
00107 /**
00108  * Calculate the IP header checksum of the packet header in uip_buf.
00109  *
00110  * The IP header checksum is the Internet checksum of the 20 bytes of
00111  * the IP header.
00112  *
00113  * \return The IP header checksum of the IP header in the uip_buf
00114  * buffer.
00115  */
00116 u16_t uip_ipchksum(void);
00117 
00118 /**
00119  * Calculate the TCP checksum of the packet in uip_buf and uip_appdata.
00120  *
00121  * The TCP checksum is the Internet checksum of data contents of the
00122  * TCP segment, and a pseudo-header as defined in RFC793.
00123  *
00124  * \note The uip_appdata pointer that points to the packet data may
00125  * point anywhere in memory, so it is not possible to simply calculate
00126  * the Internet checksum of the contents of the uip_buf buffer.
00127  *
00128  * \return The TCP checksum of the TCP segment in uip_buf and pointed
00129  * to by uip_appdata.
00130  */
00131 u16_t uip_tcpchksum(void);
00132 
00133 u16_t uip_udpchksum(void);
00134 
00135 /** @} */
00136 /** @} */
00137 
00138 #endif /* __UIP_ARCH_H__ */

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