1<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> 2<html><head><meta http-equiv="Content-Type" content="text/html;charset=iso-8859-1"> 3<title>uIP 1.0: uip/uip-split.c Source File</title> 4<link href="doxygen.css" rel="stylesheet" type="text/css"> 5<link href="tabs.css" rel="stylesheet" type="text/css"> 6</head><body> 7<!-- Generated by Doxygen 1.4.6 --> 8<div class="tabs"> 9 <ul> 10 <li><a href="main.html"><span>Main Page</span></a></li> 11 <li><a href="modules.html"><span>Modules</span></a></li> 12 <li><a href="classes.html"><span>Data Structures</span></a></li> 13 <li id="current"><a href="files.html"><span>Files</span></a></li> 14 <li><a href="examples.html"><span>Examples</span></a></li> 15 </ul></div> 16<div class="tabs"> 17 <ul> 18 <li><a href="files.html"><span>File List</span></a></li> 19 <li><a href="globals.html"><span>Globals</span></a></li> 20 </ul></div> 21<h1>uip/uip-split.c</h1><div class="fragment"><pre class="fragment"><a name="l00001"></a>00001 <span class="comment">/*</span> 22<a name="l00002"></a>00002 <span class="comment"> * Copyright (c) 2004, Swedish Institute of Computer Science.</span> 23<a name="l00003"></a>00003 <span class="comment"> * All rights reserved.</span> 24<a name="l00004"></a>00004 <span class="comment"> *</span> 25<a name="l00005"></a>00005 <span class="comment"> * Redistribution and use in source and binary forms, with or without</span> 26<a name="l00006"></a>00006 <span class="comment"> * modification, are permitted provided that the following conditions</span> 27<a name="l00007"></a>00007 <span class="comment"> * are met:</span> 28<a name="l00008"></a>00008 <span class="comment"> * 1. Redistributions of source code must retain the above copyright</span> 29<a name="l00009"></a>00009 <span class="comment"> * notice, this list of conditions and the following disclaimer.</span> 30<a name="l00010"></a>00010 <span class="comment"> * 2. Redistributions in binary form must reproduce the above copyright</span> 31<a name="l00011"></a>00011 <span class="comment"> * notice, this list of conditions and the following disclaimer in the</span> 32<a name="l00012"></a>00012 <span class="comment"> * documentation and/or other materials provided with the distribution.</span> 33<a name="l00013"></a>00013 <span class="comment"> * 3. Neither the name of the Institute nor the names of its contributors</span> 34<a name="l00014"></a>00014 <span class="comment"> * may be used to endorse or promote products derived from this software</span> 35<a name="l00015"></a>00015 <span class="comment"> * without specific prior written permission.</span> 36<a name="l00016"></a>00016 <span class="comment"> *</span> 37<a name="l00017"></a>00017 <span class="comment"> * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND</span> 38<a name="l00018"></a>00018 <span class="comment"> * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE</span> 39<a name="l00019"></a>00019 <span class="comment"> * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE</span> 40<a name="l00020"></a>00020 <span class="comment"> * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE</span> 41<a name="l00021"></a>00021 <span class="comment"> * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL</span> 42<a name="l00022"></a>00022 <span class="comment"> * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS</span> 43<a name="l00023"></a>00023 <span class="comment"> * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)</span> 44<a name="l00024"></a>00024 <span class="comment"> * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT</span> 45<a name="l00025"></a>00025 <span class="comment"> * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY</span> 46<a name="l00026"></a>00026 <span class="comment"> * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF</span> 47<a name="l00027"></a>00027 <span class="comment"> * SUCH DAMAGE.</span> 48<a name="l00028"></a>00028 <span class="comment"> *</span> 49<a name="l00029"></a>00029 <span class="comment"> * This file is part of the uIP TCP/IP stack</span> 50<a name="l00030"></a>00030 <span class="comment"> *</span> 51<a name="l00031"></a>00031 <span class="comment"> * Author: Adam Dunkels <[email protected]></span> 52<a name="l00032"></a>00032 <span class="comment"> *</span> 53<a name="l00033"></a>00033 <span class="comment"> * $Id: uip-split.c,v 1.2 2006/06/12 08:00:30 adam Exp $</span> 54<a name="l00034"></a>00034 <span class="comment"> */</span> 55<a name="l00035"></a>00035 56<a name="l00036"></a>00036 <span class="preprocessor">#include <string.h></span> 57<a name="l00037"></a>00037 58<a name="l00038"></a>00038 <span class="preprocessor">#include "<a class="code" href="a00134.html">uip-split.h</a>"</span> 59<a name="l00039"></a>00039 <span class="preprocessor">#include "<a class="code" href="a00136.html">uip.h</a>"</span> 60<a name="l00040"></a>00040 <span class="preprocessor">#include "uip-fw.h"</span> 61<a name="l00041"></a>00041 <span class="preprocessor">#include "<a class="code" href="a00137.html">uip_arch.h</a>"</span> 62<a name="l00042"></a>00042 63<a name="l00043"></a>00043 64<a name="l00044"></a>00044 65<a name="l00045"></a>00045 <span class="preprocessor">#define BUF ((struct uip_tcpip_hdr *)&uip_buf[UIP_LLH_LEN])</span> 66<a name="l00046"></a>00046 <span class="preprocessor"></span> 67<a name="l00047"></a>00047 <span class="comment">/*-----------------------------------------------------------------------------*/</span> 68<a name="l00048"></a>00048 <span class="keywordtype">void</span> 69<a name="l00049"></a><a class="code" href="a00154.html#gb4b17aaf20d630f30919b19937b966a3">00049</a> <a class="code" href="a00154.html#gb4b17aaf20d630f30919b19937b966a3">uip_split_output</a>(<span class="keywordtype">void</span>) 70<a name="l00050"></a>00050 { 71<a name="l00051"></a>00051 <a class="code" href="a00153.html#g77570ac4fcab86864fa1916e55676da2">u16_t</a> tcplen, len1, len2; 72<a name="l00052"></a>00052 73<a name="l00053"></a>00053 <span class="comment">/* We only try to split maximum sized TCP segments. */</span> 74<a name="l00054"></a>00054 <span class="keywordflow">if</span>(<a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>->proto == <a class="code" href="a00150.html#g517c770991459cc62dc009c0d3875c6a">UIP_PROTO_TCP</a> && 75<a name="l00055"></a>00055 <a class="code" href="a00149.html#g12a33f0c09711167bdf3dd7d7cf8c5a1">uip_len</a> == <a class="code" href="a00153.html#g3589822ecb9d9c4145209756396b8a6b">UIP_BUFSIZE</a> - <a class="code" href="a00153.html#ge6f4a2453dbd8bc60e6a82774552366a">UIP_LLH_LEN</a>) { 76<a name="l00056"></a>00056 77<a name="l00057"></a>00057 tcplen = <a class="code" href="a00149.html#g12a33f0c09711167bdf3dd7d7cf8c5a1">uip_len</a> - <a class="code" href="a00150.html#gee37386b2ab828787c05227eb109def7">UIP_TCPIP_HLEN</a>; 78<a name="l00058"></a>00058 <span class="comment">/* Split the segment in two. If the original packet length was</span> 79<a name="l00059"></a>00059 <span class="comment"> odd, we make the second packet one byte larger. */</span> 80<a name="l00060"></a>00060 len1 = len2 = tcplen / 2; 81<a name="l00061"></a>00061 <span class="keywordflow">if</span>(len1 + len2 < tcplen) { 82<a name="l00062"></a>00062 ++len2; 83<a name="l00063"></a>00063 } 84<a name="l00064"></a>00064 85<a name="l00065"></a>00065 <span class="comment">/* Create the first packet. This is done by altering the length</span> 86<a name="l00066"></a>00066 <span class="comment"> field of the IP header and updating the checksums. */</span> 87<a name="l00067"></a>00067 <a class="code" href="a00149.html#g12a33f0c09711167bdf3dd7d7cf8c5a1">uip_len</a> = len1 + UIP_TCPIP_HLEN; 88<a name="l00068"></a>00068 <span class="preprocessor">#if UIP_CONF_IPV6</span> 89<a name="l00069"></a>00069 <span class="preprocessor"></span> <span class="comment">/* For IPv6, the IP length field does not include the IPv6 IP header</span> 90<a name="l00070"></a>00070 <span class="comment"> length. */</span> 91<a name="l00071"></a>00071 <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>->len[0] = ((<a class="code" href="a00149.html#g12a33f0c09711167bdf3dd7d7cf8c5a1">uip_len</a> - <a class="code" href="a00150.html#g6bc12c6c7b56f73ce5d57abfdcdc6eb5">UIP_IPH_LEN</a>) >> 8); 92<a name="l00072"></a>00072 <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>->len[1] = ((<a class="code" href="a00149.html#g12a33f0c09711167bdf3dd7d7cf8c5a1">uip_len</a> - <a class="code" href="a00150.html#g6bc12c6c7b56f73ce5d57abfdcdc6eb5">UIP_IPH_LEN</a>) & 0xff); 93<a name="l00073"></a>00073 <span class="preprocessor">#else </span><span class="comment">/* UIP_CONF_IPV6 */</span> 94<a name="l00074"></a>00074 <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>->len[0] = <a class="code" href="a00149.html#g12a33f0c09711167bdf3dd7d7cf8c5a1">uip_len</a> >> 8; 95<a name="l00075"></a>00075 <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>->len[1] = <a class="code" href="a00149.html#g12a33f0c09711167bdf3dd7d7cf8c5a1">uip_len</a> & 0xff; 96<a name="l00076"></a>00076 <span class="preprocessor">#endif </span><span class="comment">/* UIP_CONF_IPV6 */</span> 97<a name="l00077"></a>00077 98<a name="l00078"></a>00078 <span class="comment">/* Recalculate the TCP checksum. */</span> 99<a name="l00079"></a>00079 <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>->tcpchksum = 0; 100<a name="l00080"></a>00080 <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>->tcpchksum = ~(<a class="code" href="a00150.html#g85b65e38aa74eba18979156f97a94a87">uip_tcpchksum</a>()); 101<a name="l00081"></a>00081 102<a name="l00082"></a>00082 <span class="preprocessor">#if !UIP_CONF_IPV6</span> 103<a name="l00083"></a>00083 <span class="preprocessor"></span> <span class="comment">/* Recalculate the IP checksum. */</span> 104<a name="l00084"></a>00084 <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>->ipchksum = 0; 105<a name="l00085"></a>00085 <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>->ipchksum = ~(<a class="code" href="a00150.html#g2addf34c7d457c1a7899a7e2171ef1e9">uip_ipchksum</a>()); 106<a name="l00086"></a>00086 <span class="preprocessor">#endif </span><span class="comment">/* UIP_CONF_IPV6 */</span> 107<a name="l00087"></a>00087 108<a name="l00088"></a>00088 <span class="comment">/* Transmit the first packet. */</span> 109<a name="l00089"></a>00089 <span class="comment">/* uip_fw_output();*/</span> 110<a name="l00090"></a>00090 tcpip_output(); 111<a name="l00091"></a>00091 112<a name="l00092"></a>00092 <span class="comment">/* Now, create the second packet. To do this, it is not enough to</span> 113<a name="l00093"></a>00093 <span class="comment"> just alter the length field, but we must also update the TCP</span> 114<a name="l00094"></a>00094 <span class="comment"> sequence number and point the uip_appdata to a new place in</span> 115<a name="l00095"></a>00095 <span class="comment"> memory. This place is detemined by the length of the first</span> 116<a name="l00096"></a>00096 <span class="comment"> packet (len1). */</span> 117<a name="l00097"></a>00097 <a class="code" href="a00149.html#g12a33f0c09711167bdf3dd7d7cf8c5a1">uip_len</a> = len2 + UIP_TCPIP_HLEN; 118<a name="l00098"></a>00098 <span class="preprocessor">#if UIP_CONF_IPV6</span> 119<a name="l00099"></a>00099 <span class="preprocessor"></span> <span class="comment">/* For IPv6, the IP length field does not include the IPv6 IP header</span> 120<a name="l00100"></a>00100 <span class="comment"> length. */</span> 121<a name="l00101"></a>00101 <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>->len[0] = ((<a class="code" href="a00149.html#g12a33f0c09711167bdf3dd7d7cf8c5a1">uip_len</a> - <a class="code" href="a00150.html#g6bc12c6c7b56f73ce5d57abfdcdc6eb5">UIP_IPH_LEN</a>) >> 8); 122<a name="l00102"></a>00102 <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>->len[1] = ((<a class="code" href="a00149.html#g12a33f0c09711167bdf3dd7d7cf8c5a1">uip_len</a> - <a class="code" href="a00150.html#g6bc12c6c7b56f73ce5d57abfdcdc6eb5">UIP_IPH_LEN</a>) & 0xff); 123<a name="l00103"></a>00103 <span class="preprocessor">#else </span><span class="comment">/* UIP_CONF_IPV6 */</span> 124<a name="l00104"></a>00104 <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>->len[0] = <a class="code" href="a00149.html#g12a33f0c09711167bdf3dd7d7cf8c5a1">uip_len</a> >> 8; 125<a name="l00105"></a>00105 <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>->len[1] = <a class="code" href="a00149.html#g12a33f0c09711167bdf3dd7d7cf8c5a1">uip_len</a> & 0xff; 126<a name="l00106"></a>00106 <span class="preprocessor">#endif </span><span class="comment">/* UIP_CONF_IPV6 */</span> 127<a name="l00107"></a>00107 128<a name="l00108"></a>00108 <span class="comment">/* uip_appdata += len1;*/</span> 129<a name="l00109"></a>00109 memcpy(<a class="code" href="a00150.html#g561b8eda32e059d4e7397f776268cc63">uip_appdata</a>, (<a class="code" href="a00153.html#g4caecabca98b43919dd11be1c0d4cd8e">u8_t</a> *)<a class="code" href="a00150.html#g561b8eda32e059d4e7397f776268cc63">uip_appdata</a> + len1, len2); 130<a name="l00110"></a>00110 131<a name="l00111"></a>00111 <a class="code" href="a00150.html#g6832e4d2d046536b6472f7ac92340f68">uip_add32</a>(<a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>->seqno, len1); 132<a name="l00112"></a>00112 <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>->seqno[0] = <a class="code" href="a00151.html#g2a0cf5d86c58fab216414ce59bf1fea1">uip_acc32</a>[0]; 133<a name="l00113"></a>00113 <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>->seqno[1] = <a class="code" href="a00151.html#g2a0cf5d86c58fab216414ce59bf1fea1">uip_acc32</a>[1]; 134<a name="l00114"></a>00114 <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>->seqno[2] = <a class="code" href="a00151.html#g2a0cf5d86c58fab216414ce59bf1fea1">uip_acc32</a>[2]; 135<a name="l00115"></a>00115 <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>->seqno[3] = <a class="code" href="a00151.html#g2a0cf5d86c58fab216414ce59bf1fea1">uip_acc32</a>[3]; 136<a name="l00116"></a>00116 137<a name="l00117"></a>00117 <span class="comment">/* Recalculate the TCP checksum. */</span> 138<a name="l00118"></a>00118 <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>->tcpchksum = 0; 139<a name="l00119"></a>00119 <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>->tcpchksum = ~(<a class="code" href="a00150.html#g85b65e38aa74eba18979156f97a94a87">uip_tcpchksum</a>()); 140<a name="l00120"></a>00120 141<a name="l00121"></a>00121 <span class="preprocessor">#if !UIP_CONF_IPV6</span> 142<a name="l00122"></a>00122 <span class="preprocessor"></span> <span class="comment">/* Recalculate the IP checksum. */</span> 143<a name="l00123"></a>00123 <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>->ipchksum = 0; 144<a name="l00124"></a>00124 <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>->ipchksum = ~(<a class="code" href="a00150.html#g2addf34c7d457c1a7899a7e2171ef1e9">uip_ipchksum</a>()); 145<a name="l00125"></a>00125 <span class="preprocessor">#endif </span><span class="comment">/* UIP_CONF_IPV6 */</span> 146<a name="l00126"></a>00126 147<a name="l00127"></a>00127 <span class="comment">/* Transmit the second packet. */</span> 148<a name="l00128"></a>00128 <span class="comment">/* uip_fw_output();*/</span> 149<a name="l00129"></a>00129 tcpip_output(); 150<a name="l00130"></a>00130 } <span class="keywordflow">else</span> { 151<a name="l00131"></a>00131 <span class="comment">/* uip_fw_output();*/</span> 152<a name="l00132"></a>00132 tcpip_output(); 153<a name="l00133"></a>00133 } 154<a name="l00134"></a>00134 155<a name="l00135"></a>00135 } 156<a name="l00136"></a>00136 <span class="comment">/*-----------------------------------------------------------------------------*/</span> 157</pre></div><hr size="1"><address style="align: right;"><small>Generated on Mon Jun 12 10:23:01 2006 for uIP 1.0 by 158<a href="http://www.doxygen.org/index.html"> 159<img src="doxygen.png" alt="doxygen" align="middle" border="0"></a> 1.4.6 </small></address> 160</body> 161</html> 162
