shenzhou-iv-stm32f107-rt-thread /rtt-1.1.0b/rt-thread_os/components/net/uip/doc/html/a00201.html

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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
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<title>uIP 1.0: uip/uip.c Source File</title>
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<h1>uip/uip.c</h1><a href="a00135.html">Go to the documentation of this file.</a><div class="fragment"><pre class="fragment"><a name="l00001"></a><a class="code" href="a00135.html#534d9e416324fb8ecca6b9cb4b1f6a6a">00001</a> <span class="preprocessor">#define DEBUG_PRINTF(...) </span><span class="comment">/*printf(__VA_ARGS__)*/</span>
<a name="l00002"></a>00002 <span class="comment"></span>
<a name="l00003"></a>00003 <span class="comment">/**</span>
<a name="l00004"></a>00004 <span class="comment"> * \defgroup uip The uIP TCP/IP stack</span>
<a name="l00005"></a>00005 <span class="comment"> * @{</span>
<a name="l00006"></a>00006 <span class="comment"> *</span>
<a name="l00007"></a>00007 <span class="comment"> * uIP is an implementation of the TCP/IP protocol stack intended for</span>
<a name="l00008"></a>00008 <span class="comment"> * small 8-bit and 16-bit microcontrollers.</span>
<a name="l00009"></a>00009 <span class="comment"> *</span>
<a name="l00010"></a>00010 <span class="comment"> * uIP provides the necessary protocols for Internet communication,</span>
<a name="l00011"></a>00011 <span class="comment"> * with a very small code footprint and RAM requirements - the uIP</span>
<a name="l00012"></a>00012 <span class="comment"> * code size is on the order of a few kilobytes and RAM usage is on</span>
<a name="l00013"></a>00013 <span class="comment"> * the order of a few hundred bytes.</span>
<a name="l00014"></a>00014 <span class="comment"> */</span>
<a name="l00015"></a>00015 <span class="comment"></span>
<a name="l00016"></a>00016 <span class="comment">/**</span>
<a name="l00017"></a>00017 <span class="comment"> * \file</span>
<a name="l00018"></a>00018 <span class="comment"> * The uIP TCP/IP stack code.</span>
<a name="l00019"></a>00019 <span class="comment"> * \author Adam Dunkels &lt;adam@dunkels.com&gt;</span>
<a name="l00020"></a>00020 <span class="comment"> */</span>
<a name="l00021"></a>00021 
<a name="l00022"></a>00022 <span class="comment">/*</span>
<a name="l00023"></a>00023 <span class="comment"> * Copyright (c) 2001-2003, Adam Dunkels.</span>
<a name="l00024"></a>00024 <span class="comment"> * All rights reserved.</span>
<a name="l00025"></a>00025 <span class="comment"> *</span>
<a name="l00026"></a>00026 <span class="comment"> * Redistribution and use in source and binary forms, with or without</span>
<a name="l00027"></a>00027 <span class="comment"> * modification, are permitted provided that the following conditions</span>
<a name="l00028"></a>00028 <span class="comment"> * are met:</span>
<a name="l00029"></a>00029 <span class="comment"> * 1. Redistributions of source code must retain the above copyright</span>
<a name="l00030"></a>00030 <span class="comment"> *    notice, this list of conditions and the following disclaimer.</span>
<a name="l00031"></a>00031 <span class="comment"> * 2. Redistributions in binary form must reproduce the above copyright</span>
<a name="l00032"></a>00032 <span class="comment"> *    notice, this list of conditions and the following disclaimer in the</span>
<a name="l00033"></a>00033 <span class="comment"> *    documentation and/or other materials provided with the distribution.</span>
<a name="l00034"></a>00034 <span class="comment"> * 3. The name of the author may not be used to endorse or promote</span>
<a name="l00035"></a>00035 <span class="comment"> *    products derived from this software without specific prior</span>
<a name="l00036"></a>00036 <span class="comment"> *    written permission.</span>
<a name="l00037"></a>00037 <span class="comment"> *</span>
<a name="l00038"></a>00038 <span class="comment"> * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS</span>
<a name="l00039"></a>00039 <span class="comment"> * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED</span>
<a name="l00040"></a>00040 <span class="comment"> * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE</span>
<a name="l00041"></a>00041 <span class="comment"> * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY</span>
<a name="l00042"></a>00042 <span class="comment"> * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL</span>
<a name="l00043"></a>00043 <span class="comment"> * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE</span>
<a name="l00044"></a>00044 <span class="comment"> * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS</span>
<a name="l00045"></a>00045 <span class="comment"> * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,</span>
<a name="l00046"></a>00046 <span class="comment"> * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING</span>
<a name="l00047"></a>00047 <span class="comment"> * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS</span>
<a name="l00048"></a>00048 <span class="comment"> * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.</span>
<a name="l00049"></a>00049 <span class="comment"> *</span>
<a name="l00050"></a>00050 <span class="comment"> * This file is part of the uIP TCP/IP stack.</span>
<a name="l00051"></a>00051 <span class="comment"> *</span>
<a name="l00052"></a>00052 <span class="comment"> * $Id: uip.c,v 1.65 2006/06/11 21:46:39 adam Exp $</span>
<a name="l00053"></a>00053 <span class="comment"> *</span>
<a name="l00054"></a>00054 <span class="comment"> */</span>
<a name="l00055"></a>00055 
<a name="l00056"></a>00056 <span class="comment">/*</span>
<a name="l00057"></a>00057 <span class="comment"> * uIP is a small implementation of the IP, UDP and TCP protocols (as</span>
<a name="l00058"></a>00058 <span class="comment"> * well as some basic ICMP stuff). The implementation couples the IP,</span>
<a name="l00059"></a>00059 <span class="comment"> * UDP, TCP and the application layers very tightly. To keep the size</span>
<a name="l00060"></a>00060 <span class="comment"> * of the compiled code down, this code frequently uses the goto</span>
<a name="l00061"></a>00061 <span class="comment"> * statement. While it would be possible to break the uip_process()</span>
<a name="l00062"></a>00062 <span class="comment"> * function into many smaller functions, this would increase the code</span>
<a name="l00063"></a>00063 <span class="comment"> * size because of the overhead of parameter passing and the fact that</span>
<a name="l00064"></a>00064 <span class="comment"> * the optimier would not be as efficient.</span>
<a name="l00065"></a>00065 <span class="comment"> *</span>
<a name="l00066"></a>00066 <span class="comment"> * The principle is that we have a small buffer, called the uip_buf,</span>
<a name="l00067"></a>00067 <span class="comment"> * in which the device driver puts an incoming packet. The TCP/IP</span>
<a name="l00068"></a>00068 <span class="comment"> * stack parses the headers in the packet, and calls the</span>
<a name="l00069"></a>00069 <span class="comment"> * application. If the remote host has sent data to the application,</span>
<a name="l00070"></a>00070 <span class="comment"> * this data is present in the uip_buf and the application read the</span>
<a name="l00071"></a>00071 <span class="comment"> * data from there. It is up to the application to put this data into</span>
<a name="l00072"></a>00072 <span class="comment"> * a byte stream if needed. The application will not be fed with data</span>
<a name="l00073"></a>00073 <span class="comment"> * that is out of sequence.</span>
<a name="l00074"></a>00074 <span class="comment"> *</span>
<a name="l00075"></a>00075 <span class="comment"> * If the application whishes to send data to the peer, it should put</span>
<a name="l00076"></a>00076 <span class="comment"> * its data into the uip_buf. The uip_appdata pointer points to the</span>
<a name="l00077"></a>00077 <span class="comment"> * first available byte. The TCP/IP stack will calculate the</span>
<a name="l00078"></a>00078 <span class="comment"> * checksums, and fill in the necessary header fields and finally send</span>
<a name="l00079"></a>00079 <span class="comment"> * the packet back to the peer.</span>
<a name="l00080"></a>00080 <span class="comment">*/</span>
<a name="l00081"></a>00081 
<a name="l00082"></a>00082 <span class="preprocessor">#include "<a class="code" href="a00136.html">uip.h</a>"</span>
<a name="l00083"></a>00083 <span class="preprocessor">#include "<a class="code" href="a00140.html">uipopt.h</a>"</span>
<a name="l00084"></a>00084 <span class="preprocessor">#include "<a class="code" href="a00137.html">uip_arch.h</a>"</span>
<a name="l00085"></a>00085 
<a name="l00086"></a>00086 <span class="preprocessor">#if UIP_CONF_IPV6</span>
<a name="l00087"></a>00087 <span class="preprocessor"></span><span class="preprocessor">#include "<a class="code" href="a00132.html">uip-neighbor.h</a>"</span>
<a name="l00088"></a>00088 <span class="preprocessor">#endif </span><span class="comment">/* UIP_CONF_IPV6 */</span>
<a name="l00089"></a>00089 
<a name="l00090"></a>00090 <span class="preprocessor">#include &lt;string.h&gt;</span>
<a name="l00091"></a>00091 
<a name="l00092"></a>00092 <span class="comment">/*---------------------------------------------------------------------------*/</span>
<a name="l00093"></a>00093 <span class="comment">/* Variable definitions. */</span>
<a name="l00094"></a>00094 
<a name="l00095"></a>00095 
<a name="l00096"></a>00096 <span class="comment">/* The IP address of this host. If it is defined to be fixed (by</span>
<a name="l00097"></a>00097 <span class="comment">   setting UIP_FIXEDADDR to 1 in uipopt.h), the address is set</span>
<a name="l00098"></a>00098 <span class="comment">   here. Otherwise, the address */</span>
<a name="l00099"></a>00099 <span class="preprocessor">#if UIP_FIXEDADDR &gt; 0</span>
<a name="l00100"></a>00100 <span class="preprocessor"></span><span class="keyword">const</span> <a class="code" href="a00150.html#g1ef35301f43a5bbb9f89f07b5a36b9a0">uip_ipaddr_t</a> <a class="code" href="a00150.html#g7d3673f52f5846b6961d23b150decd54">uip_hostaddr</a> =
<a name="l00101"></a>00101   {<a class="code" href="a00148.html#g69a7a4951ff21b302267532c21ee78fc">HTONS</a>((UIP_IPADDR0 &lt;&lt; 8) | UIP_IPADDR1),
<a name="l00102"></a>00102    <a class="code" href="a00148.html#g69a7a4951ff21b302267532c21ee78fc">HTONS</a>((UIP_IPADDR2 &lt;&lt; 8) | UIP_IPADDR3)};
<a name="l00103"></a>00103 <span class="keyword">const</span> <a class="code" href="a00150.html#g1ef35301f43a5bbb9f89f07b5a36b9a0">uip_ipaddr_t</a> <a class="code" href="a00150.html#g20df5c82f2a15a508c19e505b5d9de2b">uip_draddr</a> =
<a name="l00104"></a>00104   {<a class="code" href="a00148.html#g69a7a4951ff21b302267532c21ee78fc">HTONS</a>((UIP_DRIPADDR0 &lt;&lt; 8) | UIP_DRIPADDR1),
<a name="l00105"></a>00105    <a class="code" href="a00148.html#g69a7a4951ff21b302267532c21ee78fc">HTONS</a>((UIP_DRIPADDR2 &lt;&lt; 8) | UIP_DRIPADDR3)};
<a name="l00106"></a>00106 <span class="keyword">const</span> <a class="code" href="a00150.html#g1ef35301f43a5bbb9f89f07b5a36b9a0">uip_ipaddr_t</a> <a class="code" href="a00150.html#g3237be0d9ec457de0177689ee23c0d5c">uip_netmask</a> =
<a name="l00107"></a>00107   {<a class="code" href="a00148.html#g69a7a4951ff21b302267532c21ee78fc">HTONS</a>((UIP_NETMASK0 &lt;&lt; 8) | UIP_NETMASK1),
<a name="l00108"></a>00108    <a class="code" href="a00148.html#g69a7a4951ff21b302267532c21ee78fc">HTONS</a>((UIP_NETMASK2 &lt;&lt; 8) | UIP_NETMASK3)};
<a name="l00109"></a>00109 <span class="preprocessor">#else</span>
<a name="l00110"></a><a class="code" href="a00150.html#g3237be0d9ec457de0177689ee23c0d5c">00110</a> <span class="preprocessor"></span><a class="code" href="a00150.html#g1ef35301f43a5bbb9f89f07b5a36b9a0">uip_ipaddr_t</a> <a class="code" href="a00150.html#g7d3673f52f5846b6961d23b150decd54">uip_hostaddr</a>, <a class="code" href="a00150.html#g20df5c82f2a15a508c19e505b5d9de2b">uip_draddr</a>, uip_netmask;
<a name="l00111"></a>00111 <span class="preprocessor">#endif </span><span class="comment">/* UIP_FIXEDADDR */</span>
<a name="l00112"></a>00112 
<a name="l00113"></a>00113 <span class="keyword">static</span> <span class="keyword">const</span> <a class="code" href="a00150.html#g1ef35301f43a5bbb9f89f07b5a36b9a0">uip_ipaddr_t</a> all_ones_addr =
<a name="l00114"></a>00114 <span class="preprocessor">#if UIP_CONF_IPV6</span>
<a name="l00115"></a>00115 <span class="preprocessor"></span>  {0xffff,0xffff,0xffff,0xffff,0xffff,0xffff,0xffff,0xffff};
<a name="l00116"></a>00116 <span class="preprocessor">#else </span><span class="comment">/* UIP_CONF_IPV6 */</span>
<a name="l00117"></a>00117   {0xffff,0xffff};
<a name="l00118"></a>00118 <span class="preprocessor">#endif </span><span class="comment">/* UIP_CONF_IPV6 */</span>
<a name="l00119"></a>00119 <span class="keyword">static</span> <span class="keyword">const</span> <a class="code" href="a00150.html#g1ef35301f43a5bbb9f89f07b5a36b9a0">uip_ipaddr_t</a> all_zeroes_addr =
<a name="l00120"></a>00120 <span class="preprocessor">#if UIP_CONF_IPV6</span>
<a name="l00121"></a>00121 <span class="preprocessor"></span>  {0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000};
<a name="l00122"></a>00122 <span class="preprocessor">#else </span><span class="comment">/* UIP_CONF_IPV6 */</span>
<a name="l00123"></a>00123   {0x0000,0x0000};
<a name="l00124"></a>00124 <span class="preprocessor">#endif </span><span class="comment">/* UIP_CONF_IPV6 */</span>
<a name="l00125"></a>00125 
<a name="l00126"></a>00126 
<a name="l00127"></a>00127 <span class="preprocessor">#if UIP_FIXEDETHADDR</span>
<a name="l00128"></a>00128 <span class="preprocessor"></span><span class="keyword">const</span> <span class="keyword">struct </span><a class="code" href="a00089.html">uip_eth_addr</a> <a class="code" href="a00150.html#g499bb98a0b4ae9a98553ede81317606d">uip_ethaddr</a> = {{UIP_ETHADDR0,
<a name="l00129"></a>00129                                           UIP_ETHADDR1,
<a name="l00130"></a>00130                                           UIP_ETHADDR2,
<a name="l00131"></a>00131                                           UIP_ETHADDR3,
<a name="l00132"></a>00132                                           UIP_ETHADDR4,
<a name="l00133"></a>00133                                           UIP_ETHADDR5}};
<a name="l00134"></a>00134 <span class="preprocessor">#else</span>
<a name="l00135"></a><a class="code" href="a00152.html#g499bb98a0b4ae9a98553ede81317606d">00135</a> <span class="preprocessor"></span><span class="keyword">struct </span><a class="code" href="a00089.html">uip_eth_addr</a> <a class="code" href="a00150.html#g499bb98a0b4ae9a98553ede81317606d">uip_ethaddr</a> = {{0,0,0,0,0,0}};
<a name="l00136"></a>00136 <span class="preprocessor">#endif</span>
<a name="l00137"></a>00137 <span class="preprocessor"></span>
<a name="l00138"></a>00138 <span class="preprocessor">#ifndef UIP_CONF_EXTERNAL_BUFFER</span>
<a name="l00139"></a><a class="code" href="a00150.html#gb81e78f890dbbee50c533a9734b74fd9">00139</a> <span class="preprocessor"></span><a class="code" href="a00153.html#g4caecabca98b43919dd11be1c0d4cd8e">u8_t</a> <a class="code" href="a00146.html#gb81e78f890dbbee50c533a9734b74fd9">uip_buf</a>[<a class="code" href="a00153.html#g3589822ecb9d9c4145209756396b8a6b">UIP_BUFSIZE</a> + 2];   <span class="comment">/* The packet buffer that contains</span>
<a name="l00140"></a>00140 <span class="comment">                                    incoming packets. */</span>
<a name="l00141"></a>00141 <span class="preprocessor">#endif </span><span class="comment">/* UIP_CONF_EXTERNAL_BUFFER */</span>
<a name="l00142"></a>00142 
<a name="l00143"></a><a class="code" href="a00150.html#g561b8eda32e059d4e7397f776268cc63">00143</a> <span class="keywordtype">void</span> *<a class="code" href="a00150.html#g561b8eda32e059d4e7397f776268cc63">uip_appdata</a>;               <span class="comment">/* The uip_appdata pointer points to</span>
<a name="l00144"></a>00144 <span class="comment">                                    application data. */</span>
<a name="l00145"></a><a class="code" href="a00150.html#ga05a3dde2048480fa3ab2a5961898d18">00145</a> <span class="keywordtype">void</span> *<a class="code" href="a00150.html#ga05a3dde2048480fa3ab2a5961898d18">uip_sappdata</a>;              <span class="comment">/* The uip_appdata pointer points to</span>
<a name="l00146"></a>00146 <span class="comment">                                    the application data which is to</span>
<a name="l00147"></a>00147 <span class="comment">                                    be sent. */</span>
<a name="l00148"></a>00148 <span class="preprocessor">#if UIP_URGDATA &gt; 0</span>
<a name="l00149"></a>00149 <span class="preprocessor"></span><span class="keywordtype">void</span> *uip_urgdata;               <span class="comment">/* The uip_urgdata pointer points to</span>
<a name="l00150"></a>00150 <span class="comment">                                    urgent data (out-of-band data), if</span>
<a name="l00151"></a>00151 <span class="comment">                                    present. */</span>
<a name="l00152"></a>00152 <a class="code" href="a00153.html#g77570ac4fcab86864fa1916e55676da2">u16_t</a> uip_urglen, uip_surglen;
<a name="l00153"></a>00153 <span class="preprocessor">#endif </span><span class="comment">/* UIP_URGDATA &gt; 0 */</span>
<a name="l00154"></a>00154 
<a name="l00155"></a><a class="code" href="a00150.html#g5b5615dc240daed20949c0fded2b4679">00155</a> <a class="code" href="a00153.html#g77570ac4fcab86864fa1916e55676da2">u16_t</a> <a class="code" href="a00149.html#g12a33f0c09711167bdf3dd7d7cf8c5a1">uip_len</a>, <a class="code" href="a00150.html#g5b5615dc240daed20949c0fded2b4679">uip_slen</a>;
<a name="l00156"></a>00156                              <span class="comment">/* The uip_len is either 8 or 16 bits,</span>
<a name="l00157"></a>00157 <span class="comment">                                depending on the maximum packet</span>
<a name="l00158"></a>00158 <span class="comment">                                size. */</span>
<a name="l00159"></a>00159 
<a name="l00160"></a><a class="code" href="a00150.html#gb4ef6b00924990e7a293f66715b6d1d1">00160</a> <a class="code" href="a00153.html#g4caecabca98b43919dd11be1c0d4cd8e">u8_t</a> <a class="code" href="a00150.html#gb4ef6b00924990e7a293f66715b6d1d1">uip_flags</a>;     <span class="comment">/* The uip_flags variable is used for</span>
<a name="l00161"></a>00161 <span class="comment">                                communication between the TCP/IP stack</span>
<a name="l00162"></a>00162 <span class="comment">                                and the application program. */</span>
<a name="l00163"></a><a class="code" href="a00150.html#g788ffac72342f6172343d7f8099cbe1a">00163</a> <span class="keyword">struct </span><a class="code" href="a00088.html">uip_conn</a> *<a class="code" href="a00088.html">uip_conn</a>;   <span class="comment">/* uip_conn always points to the current</span>
<a name="l00164"></a>00164 <span class="comment">                                connection. */</span>
<a name="l00165"></a>00165 
<a name="l00166"></a><a class="code" href="a00150.html#gf703683056d2bfa5c81fa157dcb20fe2">00166</a> <span class="keyword">struct </span><a class="code" href="a00150.html#g788ffac72342f6172343d7f8099cbe1a">uip_conn</a> <a class="code" href="a00150.html#gf703683056d2bfa5c81fa157dcb20fe2">uip_conns</a>[<a class="code" href="a00153.html#gf5fe83be78b78b9e7d9e7f1e34ab1cc5">UIP_CONNS</a>];
<a name="l00167"></a>00167                              <span class="comment">/* The uip_conns array holds all TCP</span>
<a name="l00168"></a>00168 <span class="comment">                                connections. */</span>
<a name="l00169"></a><a class="code" href="a00150.html#g236d5c7872f59c8fe7b701c7252b976e">00169</a> <a class="code" href="a00153.html#g77570ac4fcab86864fa1916e55676da2">u16_t</a> <a class="code" href="a00150.html#g236d5c7872f59c8fe7b701c7252b976e">uip_listenports</a>[<a class="code" href="a00153.html#g8f4ebd8ef6c0ea665ed351d87fec09fd">UIP_LISTENPORTS</a>];
<a name="l00170"></a>00170                              <span class="comment">/* The uip_listenports list all currently</span>
<a name="l00171"></a>00171 <span class="comment">                                listning ports. */</span>
<a name="l00172"></a>00172 <span class="preprocessor">#if UIP_UDP</span>
<a name="l00173"></a><a class="code" href="a00150.html#g210f227119fc972e6222c9cb452e15a9">00173</a> <span class="preprocessor"></span><span class="keyword">struct </span><a class="code" href="a00095.html">uip_udp_conn</a> *<a class="code" href="a00095.html">uip_udp_conn</a>;
<a name="l00174"></a><a class="code" href="a00150.html#geb533744817cf6695d75293369c2248b">00174</a> <span class="keyword">struct </span><a class="code" href="a00150.html#g210f227119fc972e6222c9cb452e15a9">uip_udp_conn</a> <a class="code" href="a00150.html#geb533744817cf6695d75293369c2248b">uip_udp_conns</a>[<a class="code" href="a00153.html#g196379ceb1219a99f4495e41ccc9bbfb">UIP_UDP_CONNS</a>];
<a name="l00175"></a>00175 <span class="preprocessor">#endif </span><span class="comment">/* UIP_UDP */</span>
<a name="l00176"></a>00176 
<a name="l00177"></a>00177 <span class="keyword">static</span> <a class="code" href="a00153.html#g77570ac4fcab86864fa1916e55676da2">u16_t</a> ipid;           <span class="comment">/* Ths ipid variable is an increasing</span>
<a name="l00178"></a>00178 <span class="comment">                                number that is used for the IP ID</span>
<a name="l00179"></a>00179 <span class="comment">                                field. */</span>
<a name="l00180"></a>00180 
<a name="l00181"></a><a class="code" href="a00150.html#g22f140b02c354dfebcc7ad481c3bcd68">00181</a> <span class="keywordtype">void</span> <a class="code" href="a00145.html#g22f140b02c354dfebcc7ad481c3bcd68">uip_setipid</a>(<a class="code" href="a00153.html#g77570ac4fcab86864fa1916e55676da2">u16_t</a> <span class="keywordtype">id</span>) { ipid = id; }
<a name="l00182"></a>00182 
<a name="l00183"></a>00183 <span class="keyword">static</span> <a class="code" href="a00153.html#g4caecabca98b43919dd11be1c0d4cd8e">u8_t</a> iss[4];          <span class="comment">/* The iss variable is used for the TCP</span>
<a name="l00184"></a>00184 <span class="comment">                                initial sequence number. */</span>
<a name="l00185"></a>00185 
<a name="l00186"></a>00186 <span class="preprocessor">#if UIP_ACTIVE_OPEN</span>
<a name="l00187"></a>00187 <span class="preprocessor"></span><span class="keyword">static</span> <a class="code" href="a00153.html#g77570ac4fcab86864fa1916e55676da2">u16_t</a> lastport;       <span class="comment">/* Keeps track of the last port used for</span>
<a name="l00188"></a>00188 <span class="comment">                                a new connection. */</span>
<a name="l00189"></a>00189 <span class="preprocessor">#endif </span><span class="comment">/* UIP_ACTIVE_OPEN */</span>
<a name="l00190"></a>00190 
<a name="l00191"></a>00191 <span class="comment">/* Temporary variables. */</span>
<a name="l00192"></a><a class="code" href="a00150.html#g2a0cf5d86c58fab216414ce59bf1fea1">00192</a> <a class="code" href="a00153.html#g4caecabca98b43919dd11be1c0d4cd8e">u8_t</a> <a class="code" href="a00151.html#g2a0cf5d86c58fab216414ce59bf1fea1">uip_acc32</a>[4];
<a name="l00193"></a>00193 <span class="keyword">static</span> <a class="code" href="a00153.html#g4caecabca98b43919dd11be1c0d4cd8e">u8_t</a> c, opt;
<a name="l00194"></a>00194 <span class="keyword">static</span> <a class="code" href="a00153.html#g77570ac4fcab86864fa1916e55676da2">u16_t</a> tmp16;
<a name="l00195"></a>00195 
<a name="l00196"></a>00196 <span class="comment">/* Structures and definitions. */</span>
<a name="l00197"></a><a class="code" href="a00150.html#g88e60aa2cf23e1c65d630701db08c743">00197</a> <span class="preprocessor">#define TCP_FIN 0x01</span>
<a name="l00198"></a><a class="code" href="a00150.html#g6020613f5062417d9811cfa837215c83">00198</a> <span class="preprocessor"></span><span class="preprocessor">#define TCP_SYN 0x02</span>
<a name="l00199"></a><a class="code" href="a00150.html#g5ca559def464ef20d8b1f7d32f2f160d">00199</a> <span class="preprocessor"></span><span class="preprocessor">#define TCP_RST 0x04</span>
<a name="l00200"></a><a class="code" href="a00150.html#g1320fd0006a2f70138bc2d0018dda829">00200</a> <span class="preprocessor"></span><span class="preprocessor">#define TCP_PSH 0x08</span>
<a name="l00201"></a><a class="code" href="a00150.html#g44b3b1ab31a403ba28ec135adfcbefef">00201</a> <span class="preprocessor"></span><span class="preprocessor">#define TCP_ACK 0x10</span>
<a name="l00202"></a><a class="code" href="a00150.html#gc84f499cba8a02fc0e306c10b2acabf0">00202</a> <span class="preprocessor"></span><span class="preprocessor">#define TCP_URG 0x20</span>
<a name="l00203"></a><a class="code" href="a00150.html#g1425d4a0c2760adb653a04c0fb137a8d">00203</a> <span class="preprocessor"></span><span class="preprocessor">#define TCP_CTL 0x3f</span>
<a name="l00204"></a>00204 <span class="preprocessor"></span>
<a name="l00205"></a><a class="code" href="a00150.html#g1215163245304bad20d6c5608ad75ab7">00205</a> <span class="preprocessor">#define TCP_OPT_END     0   </span><span class="comment">/* End of TCP options list */</span>
<a name="l00206"></a><a class="code" href="a00150.html#g9f1822e1d231235edacad691f3cb7bbb">00206</a> <span class="preprocessor">#define TCP_OPT_NOOP    1   </span><span class="comment">/* "No-operation" TCP option */</span>
<a name="l00207"></a><a class="code" href="a00150.html#g691688604655ea8943d15f14c60027d8">00207</a> <span class="preprocessor">#define TCP_OPT_MSS     2   </span><span class="comment">/* Maximum segment size TCP option */</span>
<a name="l00208"></a>00208 
<a name="l00209"></a><a class="code" href="a00150.html#g12f3bf821224b8e7b48a57ed3cea15cf">00209</a> <span class="preprocessor">#define TCP_OPT_MSS_LEN 4   </span><span class="comment">/* Length of TCP MSS option. */</span>
<a name="l00210"></a>00210 
<a name="l00211"></a><a class="code" href="a00150.html#g5c5b1834e497f53ad0ef947bbe9777fa">00211</a> <span class="preprocessor">#define ICMP_ECHO_REPLY 0</span>
<a name="l00212"></a><a class="code" href="a00150.html#gd58231410d58e34b455328b888a9e73c">00212</a> <span class="preprocessor"></span><span class="preprocessor">#define ICMP_ECHO       8</span>
<a name="l00213"></a>00213 <span class="preprocessor"></span>
<a name="l00214"></a><a class="code" href="a00150.html#g207d17b633cd095120a74bc1f2257b17">00214</a> <span class="preprocessor">#define ICMP6_ECHO_REPLY             129</span>
<a name="l00215"></a><a class="code" href="a00150.html#g4cc3e223b63f27b546d62e9a258dba5a">00215</a> <span class="preprocessor"></span><span class="preprocessor">#define ICMP6_ECHO                   128</span>
<a name="l00216"></a><a class="code" href="a00150.html#g1cea57e3ea526f210b1068e6dcf7b4f4">00216</a> <span class="preprocessor"></span><span class="preprocessor">#define ICMP6_NEIGHBOR_SOLICITATION  135</span>
<a name="l00217"></a><a class="code" href="a00150.html#g62c03e0a308cc23929a80fe8d8f9dc1e">00217</a> <span class="preprocessor"></span><span class="preprocessor">#define ICMP6_NEIGHBOR_ADVERTISEMENT 136</span>
<a name="l00218"></a>00218 <span class="preprocessor"></span>
<a name="l00219"></a><a class="code" href="a00150.html#g1d3211dbbdfb22d6a47b60dddcf945e8">00219</a> <span class="preprocessor">#define ICMP6_FLAG_S (1 &lt;&lt; 6)</span>
<a name="l00220"></a>00220 <span class="preprocessor"></span>
<a name="l00221"></a><a class="code" href="a00150.html#g42288d5c3cf4b10becefec657f441e54">00221</a> <span class="preprocessor">#define ICMP6_OPTION_SOURCE_LINK_ADDRESS 1</span>
<a name="l00222"></a><a class="code" href="a00150.html#g8387881de3a8bfd3c0d57b9d04ac9b7e">00222</a> <span class="preprocessor"></span><span class="preprocessor">#define ICMP6_OPTION_TARGET_LINK_ADDRESS 2</span>
<a name="l00223"></a>00223 <span class="preprocessor"></span>
<a name="l00224"></a>00224 
<a name="l00225"></a>00225 <span class="comment">/* Macros. */</span>
<a name="l00226"></a><a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">00226</a> <span class="preprocessor">#define BUF ((struct uip_tcpip_hdr *)&amp;uip_buf[UIP_LLH_LEN])</span>
<a name="l00227"></a><a class="code" href="a00150.html#g96544dedc1cdc71ad2ad54bf1d5e5433">00227</a> <span class="preprocessor"></span><span class="preprocessor">#define FBUF ((struct uip_tcpip_hdr *)&amp;uip_reassbuf[0])</span>
<a name="l00228"></a><a class="code" href="a00150.html#g4309376690872fa4beb4f025f5cc199b">00228</a> <span class="preprocessor"></span><span class="preprocessor">#define ICMPBUF ((struct uip_icmpip_hdr *)&amp;uip_buf[UIP_LLH_LEN])</span>
<a name="l00229"></a><a class="code" href="a00150.html#gb9435261753469accec0c9bf8a5a2686">00229</a> <span class="preprocessor"></span><span class="preprocessor">#define UDPBUF ((struct uip_udpip_hdr *)&amp;uip_buf[UIP_LLH_LEN])</span>
<a name="l00230"></a>00230 <span class="preprocessor"></span>
<a name="l00231"></a>00231 
<a name="l00232"></a>00232 <span class="preprocessor">#if UIP_STATISTICS == 1</span>
<a name="l00233"></a>00233 <span class="preprocessor"></span><span class="keyword">struct </span><a class="code" href="a00093.html">uip_stats</a> <a class="code" href="a00150.html#g9ee50a40597e67fce96541ab56c3b712">uip_stat</a>;
<a name="l00234"></a>00234 <span class="preprocessor">#define UIP_STAT(s) s</span>
<a name="l00235"></a>00235 <span class="preprocessor"></span><span class="preprocessor">#else</span>
<a name="l00236"></a><a class="code" href="a00150.html#g9c0814ed491fa452ec97910c0728d410">00236</a> <span class="preprocessor"></span><span class="preprocessor">#define UIP_STAT(s)</span>
<a name="l00237"></a>00237 <span class="preprocessor"></span><span class="preprocessor">#endif </span><span class="comment">/* UIP_STATISTICS == 1 */</span>
<a name="l00238"></a>00238 
<a name="l00239"></a>00239 <span class="preprocessor">#if UIP_LOGGING == 1</span>
<a name="l00240"></a>00240 <span class="preprocessor"></span><span class="preprocessor">#include &lt;stdio.h&gt;</span>
<a name="l00241"></a>00241 <span class="keywordtype">void</span> <a class="code" href="a00153.html#gb58e1ceb7cb73ca2bcd73146b6c1b4e7">uip_log</a>(<span class="keywordtype">char</span> *msg);
<a name="l00242"></a>00242 <span class="preprocessor">#define UIP_LOG(m) uip_log(m)</span>
<a name="l00243"></a>00243 <span class="preprocessor"></span><span class="preprocessor">#else</span>
<a name="l00244"></a><a class="code" href="a00150.html#g013c3a06a8b58589a77f4a3442f89c2a">00244</a> <span class="preprocessor"></span><span class="preprocessor">#define UIP_LOG(m)</span>
<a name="l00245"></a>00245 <span class="preprocessor"></span><span class="preprocessor">#endif </span><span class="comment">/* UIP_LOGGING == 1 */</span>
<a name="l00246"></a>00246 
<a name="l00247"></a>00247 <span class="preprocessor">#if ! UIP_ARCH_ADD32</span>
<a name="l00248"></a>00248 <span class="preprocessor"></span><span class="keywordtype">void</span>
<a name="l00249"></a><a class="code" href="a00151.html#g6832e4d2d046536b6472f7ac92340f68">00249</a> <a class="code" href="a00150.html#g6832e4d2d046536b6472f7ac92340f68">uip_add32</a>(<a class="code" href="a00153.html#g4caecabca98b43919dd11be1c0d4cd8e">u8_t</a> *op32, <a class="code" href="a00153.html#g77570ac4fcab86864fa1916e55676da2">u16_t</a> op16)
<a name="l00250"></a>00250 {
<a name="l00251"></a>00251   uip_acc32[3] = op32[3] + (op16 &amp; 0xff);
<a name="l00252"></a>00252   uip_acc32[2] = op32[2] + (op16 &gt;&gt; 8);
<a name="l00253"></a>00253   uip_acc32[1] = op32[1];
<a name="l00254"></a>00254   uip_acc32[0] = op32[0];
<a name="l00255"></a>00255   
<a name="l00256"></a>00256   <span class="keywordflow">if</span>(uip_acc32[2] &lt; (op16 &gt;&gt; 8)) {
<a name="l00257"></a>00257     ++uip_acc32[1];
<a name="l00258"></a>00258     <span class="keywordflow">if</span>(uip_acc32[1] == 0) {
<a name="l00259"></a>00259       ++uip_acc32[0];
<a name="l00260"></a>00260     }
<a name="l00261"></a>00261   }
<a name="l00262"></a>00262   
<a name="l00263"></a>00263   
<a name="l00264"></a>00264   <span class="keywordflow">if</span>(uip_acc32[3] &lt; (op16 &amp; 0xff)) {
<a name="l00265"></a>00265     ++uip_acc32[2];
<a name="l00266"></a>00266     <span class="keywordflow">if</span>(uip_acc32[2] == 0) {
<a name="l00267"></a>00267       ++uip_acc32[1];
<a name="l00268"></a>00268       <span class="keywordflow">if</span>(uip_acc32[1] == 0) {
<a name="l00269"></a>00269         ++uip_acc32[0];
<a name="l00270"></a>00270       }
<a name="l00271"></a>00271     }
<a name="l00272"></a>00272   }
<a name="l00273"></a>00273 }
<a name="l00274"></a>00274 
<a name="l00275"></a>00275 <span class="preprocessor">#endif </span><span class="comment">/* UIP_ARCH_ADD32 */</span>
<a name="l00276"></a>00276 
<a name="l00277"></a>00277 <span class="preprocessor">#if ! UIP_ARCH_CHKSUM</span>
<a name="l00278"></a>00278 <span class="preprocessor"></span><span class="comment">/*---------------------------------------------------------------------------*/</span>
<a name="l00279"></a>00279 <span class="keyword">static</span> <a class="code" href="a00153.html#g77570ac4fcab86864fa1916e55676da2">u16_t</a>
<a name="l00280"></a>00280 chksum(<a class="code" href="a00153.html#g77570ac4fcab86864fa1916e55676da2">u16_t</a> sum, <span class="keyword">const</span> <a class="code" href="a00153.html#g4caecabca98b43919dd11be1c0d4cd8e">u8_t</a> *data, <a class="code" href="a00153.html#g77570ac4fcab86864fa1916e55676da2">u16_t</a> len)
<a name="l00281"></a>00281 {
<a name="l00282"></a>00282   <a class="code" href="a00153.html#g77570ac4fcab86864fa1916e55676da2">u16_t</a> t;
<a name="l00283"></a>00283   <span class="keyword">const</span> <a class="code" href="a00153.html#g4caecabca98b43919dd11be1c0d4cd8e">u8_t</a> *dataptr;
<a name="l00284"></a>00284   <span class="keyword">const</span> <a class="code" href="a00153.html#g4caecabca98b43919dd11be1c0d4cd8e">u8_t</a> *last_byte;
<a name="l00285"></a>00285 
<a name="l00286"></a>00286   dataptr = data;
<a name="l00287"></a>00287   last_byte = data + len - 1;
<a name="l00288"></a>00288   
<a name="l00289"></a>00289   <span class="keywordflow">while</span>(dataptr &lt; last_byte) {  <span class="comment">/* At least two more bytes */</span>
<a name="l00290"></a>00290     t = (dataptr[0] &lt;&lt; 8) + dataptr[1];
<a name="l00291"></a>00291     sum += t;
<a name="l00292"></a>00292     <span class="keywordflow">if</span>(sum &lt; t) {
<a name="l00293"></a>00293       sum++;            <span class="comment">/* carry */</span>
<a name="l00294"></a>00294     }
<a name="l00295"></a>00295     dataptr += 2;
<a name="l00296"></a>00296   }
<a name="l00297"></a>00297   
<a name="l00298"></a>00298   <span class="keywordflow">if</span>(dataptr == last_byte) {
<a name="l00299"></a>00299     t = (dataptr[0] &lt;&lt; 8) + 0;
<a name="l00300"></a>00300     sum += t;
<a name="l00301"></a>00301     <span class="keywordflow">if</span>(sum &lt; t) {
<a name="l00302"></a>00302       sum++;            <span class="comment">/* carry */</span>
<a name="l00303"></a>00303     }
<a name="l00304"></a>00304   }
<a name="l00305"></a>00305 
<a name="l00306"></a>00306   <span class="comment">/* Return sum in host byte order. */</span>
<a name="l00307"></a>00307   <span class="keywordflow">return</span> sum;
<a name="l00308"></a>00308 }
<a name="l00309"></a>00309 <span class="comment">/*---------------------------------------------------------------------------*/</span>
<a name="l00310"></a>00310 <a class="code" href="a00153.html#g77570ac4fcab86864fa1916e55676da2">u16_t</a>
<a name="l00311"></a><a class="code" href="a00150.html#gb6683dd83fe1c8de9a24086d4b69e907">00311</a> <a class="code" href="a00150.html#gb6683dd83fe1c8de9a24086d4b69e907">uip_chksum</a>(<a class="code" href="a00153.html#g77570ac4fcab86864fa1916e55676da2">u16_t</a> *data, <a class="code" href="a00153.html#g77570ac4fcab86864fa1916e55676da2">u16_t</a> len)
<a name="l00312"></a>00312 {
<a name="l00313"></a>00313   <span class="keywordflow">return</span> <a class="code" href="a00148.html#ga22b04cac8cf283ca12f028578bebc06">htons</a>(chksum(0, (<a class="code" href="a00153.html#g4caecabca98b43919dd11be1c0d4cd8e">u8_t</a> *)data, len));
<a name="l00314"></a>00314 }
<a name="l00315"></a>00315 <span class="comment">/*---------------------------------------------------------------------------*/</span>
<a name="l00316"></a>00316 <span class="preprocessor">#ifndef UIP_ARCH_IPCHKSUM</span>
<a name="l00317"></a>00317 <span class="preprocessor"></span><a class="code" href="a00153.html#g77570ac4fcab86864fa1916e55676da2">u16_t</a>
<a name="l00318"></a><a class="code" href="a00150.html#g2addf34c7d457c1a7899a7e2171ef1e9">00318</a> <a class="code" href="a00150.html#g2addf34c7d457c1a7899a7e2171ef1e9">uip_ipchksum</a>(<span class="keywordtype">void</span>)
<a name="l00319"></a>00319 {
<a name="l00320"></a>00320   <a class="code" href="a00153.html#g77570ac4fcab86864fa1916e55676da2">u16_t</a> sum;
<a name="l00321"></a>00321 
<a name="l00322"></a>00322   sum = chksum(0, &amp;uip_buf[<a class="code" href="a00153.html#ge6f4a2453dbd8bc60e6a82774552366a">UIP_LLH_LEN</a>], <a class="code" href="a00150.html#g6bc12c6c7b56f73ce5d57abfdcdc6eb5">UIP_IPH_LEN</a>);
<a name="l00323"></a>00323   <a class="code" href="a00135.html#534d9e416324fb8ecca6b9cb4b1f6a6a">DEBUG_PRINTF</a>(<span class="stringliteral">"uip_ipchksum: sum 0x%04x\n"</span>, sum);
<a name="l00324"></a>00324   <span class="keywordflow">return</span> (sum == 0) ? 0xffff : <a class="code" href="a00148.html#ga22b04cac8cf283ca12f028578bebc06">htons</a>(sum);
<a name="l00325"></a>00325 }
<a name="l00326"></a>00326 <span class="preprocessor">#endif</span>
<a name="l00327"></a>00327 <span class="preprocessor"></span><span class="comment">/*---------------------------------------------------------------------------*/</span>
<a name="l00328"></a>00328 <span class="keyword">static</span> <a class="code" href="a00153.html#g77570ac4fcab86864fa1916e55676da2">u16_t</a>
<a name="l00329"></a>00329 upper_layer_chksum(<a class="code" href="a00153.html#g4caecabca98b43919dd11be1c0d4cd8e">u8_t</a> proto)
<a name="l00330"></a>00330 {
<a name="l00331"></a>00331   <a class="code" href="a00153.html#g77570ac4fcab86864fa1916e55676da2">u16_t</a> upper_layer_len;
<a name="l00332"></a>00332   <a class="code" href="a00153.html#g77570ac4fcab86864fa1916e55676da2">u16_t</a> sum;
<a name="l00333"></a>00333   
<a name="l00334"></a>00334 <span class="preprocessor">#if UIP_CONF_IPV6</span>
<a name="l00335"></a>00335 <span class="preprocessor"></span>  upper_layer_len = (((<a class="code" href="a00153.html#g77570ac4fcab86864fa1916e55676da2">u16_t</a>)(<a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;len[0]) &lt;&lt; 8) + <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;len[1]);
<a name="l00336"></a>00336 <span class="preprocessor">#else </span><span class="comment">/* UIP_CONF_IPV6 */</span>
<a name="l00337"></a>00337   upper_layer_len = (((<a class="code" href="a00153.html#g77570ac4fcab86864fa1916e55676da2">u16_t</a>)(<a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;len[0]) &lt;&lt; 8) + <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;len[1]) - <a class="code" href="a00150.html#g6bc12c6c7b56f73ce5d57abfdcdc6eb5">UIP_IPH_LEN</a>;
<a name="l00338"></a>00338 <span class="preprocessor">#endif </span><span class="comment">/* UIP_CONF_IPV6 */</span>
<a name="l00339"></a>00339   
<a name="l00340"></a>00340   <span class="comment">/* First sum pseudoheader. */</span>
<a name="l00341"></a>00341   
<a name="l00342"></a>00342   <span class="comment">/* IP protocol and length fields. This addition cannot carry. */</span>
<a name="l00343"></a>00343   sum = upper_layer_len + proto;
<a name="l00344"></a>00344   <span class="comment">/* Sum IP source and destination addresses. */</span>
<a name="l00345"></a>00345   sum = chksum(sum, (<a class="code" href="a00153.html#g4caecabca98b43919dd11be1c0d4cd8e">u8_t</a> *)&amp;<a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;srcipaddr[0], 2 * <span class="keyword">sizeof</span>(<a class="code" href="a00150.html#g1ef35301f43a5bbb9f89f07b5a36b9a0">uip_ipaddr_t</a>));
<a name="l00346"></a>00346 
<a name="l00347"></a>00347   <span class="comment">/* Sum TCP header and data. */</span>
<a name="l00348"></a>00348   sum = chksum(sum, &amp;uip_buf[<a class="code" href="a00150.html#g6bc12c6c7b56f73ce5d57abfdcdc6eb5">UIP_IPH_LEN</a> + <a class="code" href="a00153.html#ge6f4a2453dbd8bc60e6a82774552366a">UIP_LLH_LEN</a>],
<a name="l00349"></a>00349                upper_layer_len);
<a name="l00350"></a>00350     
<a name="l00351"></a>00351   <span class="keywordflow">return</span> (sum == 0) ? 0xffff : <a class="code" href="a00148.html#ga22b04cac8cf283ca12f028578bebc06">htons</a>(sum);
<a name="l00352"></a>00352 }
<a name="l00353"></a>00353 <span class="comment">/*---------------------------------------------------------------------------*/</span>
<a name="l00354"></a>00354 <span class="preprocessor">#if UIP_CONF_IPV6</span>
<a name="l00355"></a>00355 <span class="preprocessor"></span><a class="code" href="a00153.html#g77570ac4fcab86864fa1916e55676da2">u16_t</a>
<a name="l00356"></a>00356 uip_icmp6chksum(<span class="keywordtype">void</span>)
<a name="l00357"></a>00357 {
<a name="l00358"></a>00358   <span class="keywordflow">return</span> upper_layer_chksum(<a class="code" href="a00150.html#gad0321f4c570f9983c6de81ece3ddc20">UIP_PROTO_ICMP6</a>);
<a name="l00359"></a>00359   
<a name="l00360"></a>00360 }
<a name="l00361"></a>00361 <span class="preprocessor">#endif </span><span class="comment">/* UIP_CONF_IPV6 */</span>
<a name="l00362"></a>00362 <span class="comment">/*---------------------------------------------------------------------------*/</span>
<a name="l00363"></a>00363 <a class="code" href="a00153.html#g77570ac4fcab86864fa1916e55676da2">u16_t</a>
<a name="l00364"></a><a class="code" href="a00150.html#g85b65e38aa74eba18979156f97a94a87">00364</a> <a class="code" href="a00150.html#g85b65e38aa74eba18979156f97a94a87">uip_tcpchksum</a>(<span class="keywordtype">void</span>)
<a name="l00365"></a>00365 {
<a name="l00366"></a>00366   <span class="keywordflow">return</span> upper_layer_chksum(<a class="code" href="a00150.html#g517c770991459cc62dc009c0d3875c6a">UIP_PROTO_TCP</a>);
<a name="l00367"></a>00367 }
<a name="l00368"></a>00368 <span class="comment">/*---------------------------------------------------------------------------*/</span>
<a name="l00369"></a>00369 <span class="preprocessor">#if UIP_UDP_CHECKSUMS</span>
<a name="l00370"></a>00370 <span class="preprocessor"></span><a class="code" href="a00153.html#g77570ac4fcab86864fa1916e55676da2">u16_t</a>
<a name="l00371"></a>00371 <a class="code" href="a00150.html#g7023a34ba9e9d03b5fbedbcb32924453">uip_udpchksum</a>(<span class="keywordtype">void</span>)
<a name="l00372"></a>00372 {
<a name="l00373"></a>00373   <span class="keywordflow">return</span> upper_layer_chksum(<a class="code" href="a00150.html#gf72d7b9a737707dcfb2c41fec2b6792e">UIP_PROTO_UDP</a>);
<a name="l00374"></a>00374 }
<a name="l00375"></a>00375 <span class="preprocessor">#endif </span><span class="comment">/* UIP_UDP_CHECKSUMS */</span>
<a name="l00376"></a>00376 <span class="preprocessor">#endif </span><span class="comment">/* UIP_ARCH_CHKSUM */</span>
<a name="l00377"></a>00377 <span class="comment">/*---------------------------------------------------------------------------*/</span>
<a name="l00378"></a>00378 <span class="keywordtype">void</span>
<a name="l00379"></a><a class="code" href="a00150.html#gc48ed5f0d27721ef62a3ed02a5ad8d2e">00379</a> <a class="code" href="a00145.html#gc48ed5f0d27721ef62a3ed02a5ad8d2e">uip_init</a>(<span class="keywordtype">void</span>)
<a name="l00380"></a>00380 {
<a name="l00381"></a>00381   <span class="keywordflow">for</span>(c = 0; c &lt; <a class="code" href="a00153.html#g8f4ebd8ef6c0ea665ed351d87fec09fd">UIP_LISTENPORTS</a>; ++c) {
<a name="l00382"></a>00382     uip_listenports[c] = 0;
<a name="l00383"></a>00383   }
<a name="l00384"></a>00384   <span class="keywordflow">for</span>(c = 0; c &lt; <a class="code" href="a00153.html#gf5fe83be78b78b9e7d9e7f1e34ab1cc5">UIP_CONNS</a>; ++c) {
<a name="l00385"></a>00385     <a class="code" href="a00150.html#gf703683056d2bfa5c81fa157dcb20fe2">uip_conns</a>[c].tcpstateflags = <a class="code" href="a00150.html#g28eda870cff3d8e3cf2949e6f57a502b">UIP_CLOSED</a>;
<a name="l00386"></a>00386   }
<a name="l00387"></a>00387 <span class="preprocessor">#if UIP_ACTIVE_OPEN</span>
<a name="l00388"></a>00388 <span class="preprocessor"></span>  lastport = 1024;
<a name="l00389"></a>00389 <span class="preprocessor">#endif </span><span class="comment">/* UIP_ACTIVE_OPEN */</span>
<a name="l00390"></a>00390 
<a name="l00391"></a>00391 <span class="preprocessor">#if UIP_UDP</span>
<a name="l00392"></a>00392 <span class="preprocessor"></span>  <span class="keywordflow">for</span>(c = 0; c &lt; <a class="code" href="a00153.html#g196379ceb1219a99f4495e41ccc9bbfb">UIP_UDP_CONNS</a>; ++c) {
<a name="l00393"></a>00393     <a class="code" href="a00150.html#geb533744817cf6695d75293369c2248b">uip_udp_conns</a>[c].lport = 0;
<a name="l00394"></a>00394   }
<a name="l00395"></a>00395 <span class="preprocessor">#endif </span><span class="comment">/* UIP_UDP */</span>
<a name="l00396"></a>00396   
<a name="l00397"></a>00397 
<a name="l00398"></a>00398   <span class="comment">/* IPv4 initialization. */</span>
<a name="l00399"></a>00399 <span class="preprocessor">#if UIP_FIXEDADDR == 0</span>
<a name="l00400"></a>00400 <span class="preprocessor"></span>  <span class="comment">/*  uip_hostaddr[0] = uip_hostaddr[1] = 0;*/</span>
<a name="l00401"></a>00401 <span class="preprocessor">#endif </span><span class="comment">/* UIP_FIXEDADDR */</span>
<a name="l00402"></a>00402 
<a name="l00403"></a>00403 }
<a name="l00404"></a>00404 <span class="comment">/*---------------------------------------------------------------------------*/</span>
<a name="l00405"></a>00405 <span class="preprocessor">#if UIP_ACTIVE_OPEN</span>
<a name="l00406"></a>00406 <span class="preprocessor"></span><span class="keyword">struct </span><a class="code" href="a00150.html#g788ffac72342f6172343d7f8099cbe1a">uip_conn</a> *
<a name="l00407"></a><a class="code" href="a00150.html#g9c24fba2cd8f7f62accb0a0d5bbe4dad">00407</a> <a class="code" href="a00147.html#g8096b0c4b543dc408f4dd031ddae7240">uip_connect</a>(<a class="code" href="a00150.html#g1ef35301f43a5bbb9f89f07b5a36b9a0">uip_ipaddr_t</a> *<a class="code" href="a00088.html#79510aa86d3fa0a0fc6cfc49b1da7279">ripaddr</a>, <a class="code" href="a00153.html#g77570ac4fcab86864fa1916e55676da2">u16_t</a> <a class="code" href="a00088.html#1df6aa054ef2fa634ac4c6f418228285">rport</a>)
<a name="l00408"></a>00408 {
<a name="l00409"></a>00409   <span class="keyword">register</span> <span class="keyword">struct </span><a class="code" href="a00150.html#g788ffac72342f6172343d7f8099cbe1a">uip_conn</a> *conn, *cconn;
<a name="l00410"></a>00410   
<a name="l00411"></a>00411   <span class="comment">/* Find an unused local port. */</span>
<a name="l00412"></a>00412  again:
<a name="l00413"></a>00413   ++lastport;
<a name="l00414"></a>00414 
<a name="l00415"></a>00415   <span class="keywordflow">if</span>(lastport &gt;= 32000) {
<a name="l00416"></a>00416     lastport = 4096;
<a name="l00417"></a>00417   }
<a name="l00418"></a>00418 
<a name="l00419"></a>00419   <span class="comment">/* Check if this port is already in use, and if so try to find</span>
<a name="l00420"></a>00420 <span class="comment">     another one. */</span>
<a name="l00421"></a>00421   <span class="keywordflow">for</span>(c = 0; c &lt; <a class="code" href="a00153.html#gf5fe83be78b78b9e7d9e7f1e34ab1cc5">UIP_CONNS</a>; ++c) {
<a name="l00422"></a>00422     conn = &amp;<a class="code" href="a00150.html#gf703683056d2bfa5c81fa157dcb20fe2">uip_conns</a>[c];
<a name="l00423"></a>00423     <span class="keywordflow">if</span>(conn-&gt;<a class="code" href="a00088.html#a5f58074435cdc180f17de69651beebd">tcpstateflags</a> != <a class="code" href="a00150.html#g28eda870cff3d8e3cf2949e6f57a502b">UIP_CLOSED</a> &amp;&amp;
<a name="l00424"></a>00424        conn-&gt;<a class="code" href="a00088.html#0cd09beee671e7e9efb0b4aced10249e">lport</a> == <a class="code" href="a00148.html#ga22b04cac8cf283ca12f028578bebc06">htons</a>(lastport)) {
<a name="l00425"></a>00425       <span class="keywordflow">goto</span> again;
<a name="l00426"></a>00426     }
<a name="l00427"></a>00427   }
<a name="l00428"></a>00428 
<a name="l00429"></a>00429   conn = 0;
<a name="l00430"></a>00430   <span class="keywordflow">for</span>(c = 0; c &lt; <a class="code" href="a00153.html#gf5fe83be78b78b9e7d9e7f1e34ab1cc5">UIP_CONNS</a>; ++c) {
<a name="l00431"></a>00431     cconn = &amp;<a class="code" href="a00150.html#gf703683056d2bfa5c81fa157dcb20fe2">uip_conns</a>[c];
<a name="l00432"></a>00432     <span class="keywordflow">if</span>(cconn-&gt;tcpstateflags == <a class="code" href="a00150.html#g28eda870cff3d8e3cf2949e6f57a502b">UIP_CLOSED</a>) {
<a name="l00433"></a>00433       conn = cconn;
<a name="l00434"></a>00434       <span class="keywordflow">break</span>;
<a name="l00435"></a>00435     }
<a name="l00436"></a>00436     <span class="keywordflow">if</span>(cconn-&gt;tcpstateflags == <a class="code" href="a00150.html#gfff0ed43201bf1e2020de1a0d6cac070">UIP_TIME_WAIT</a>) {
<a name="l00437"></a>00437       <span class="keywordflow">if</span>(conn == 0 ||
<a name="l00438"></a>00438          cconn-&gt;timer &gt; conn-&gt;timer) {
<a name="l00439"></a>00439         conn = cconn;
<a name="l00440"></a>00440       }
<a name="l00441"></a>00441     }
<a name="l00442"></a>00442   }
<a name="l00443"></a>00443 
<a name="l00444"></a>00444   <span class="keywordflow">if</span>(conn == 0) {
<a name="l00445"></a>00445     <span class="keywordflow">return</span> 0;
<a name="l00446"></a>00446   }
<a name="l00447"></a>00447   
<a name="l00448"></a>00448   conn-&gt;<a class="code" href="a00088.html#a5f58074435cdc180f17de69651beebd">tcpstateflags</a> = <a class="code" href="a00150.html#g8af482dec973db57d8b3bd3f69461488">UIP_SYN_SENT</a>;
<a name="l00449"></a>00449 
<a name="l00450"></a>00450   conn-&gt;snd_nxt[0] = iss[0];
<a name="l00451"></a>00451   conn-&gt;snd_nxt[1] = iss[1];
<a name="l00452"></a>00452   conn-&gt;snd_nxt[2] = iss[2];
<a name="l00453"></a>00453   conn-&gt;snd_nxt[3] = iss[3];
<a name="l00454"></a>00454 
<a name="l00455"></a>00455   conn-&gt;initialmss = conn-&gt;mss = <a class="code" href="a00153.html#g4910467b83a639f06739c82cd362037e">UIP_TCP_MSS</a>;
<a name="l00456"></a>00456   
<a name="l00457"></a>00457   conn-&gt;len = 1;   <span class="comment">/* TCP length of the SYN is one. */</span>
<a name="l00458"></a>00458   conn-&gt;nrtx = 0;
<a name="l00459"></a>00459   conn-&gt;timer = 1; <span class="comment">/* Send the SYN next time around. */</span>
<a name="l00460"></a>00460   conn-&gt;rto = <a class="code" href="a00153.html#g15de27b044603284f68db05a378235a7">UIP_RTO</a>;
<a name="l00461"></a>00461   conn-&gt;sa = 0;
<a name="l00462"></a>00462   conn-&gt;sv = 16;   <span class="comment">/* Initial value of the RTT variance. */</span>
<a name="l00463"></a>00463   conn-&gt;lport = <a class="code" href="a00148.html#ga22b04cac8cf283ca12f028578bebc06">htons</a>(lastport);
<a name="l00464"></a>00464   conn-&gt;rport = <a class="code" href="a00088.html#1df6aa054ef2fa634ac4c6f418228285">rport</a>;
<a name="l00465"></a>00465   <a class="code" href="a00148.html#g769512993b7b27271909d6daa4748b60">uip_ipaddr_copy</a>(&amp;conn-&gt;ripaddr, <a class="code" href="a00088.html#79510aa86d3fa0a0fc6cfc49b1da7279">ripaddr</a>);
<a name="l00466"></a>00466   
<a name="l00467"></a>00467   <span class="keywordflow">return</span> conn;
<a name="l00468"></a>00468 }
<a name="l00469"></a>00469 <span class="preprocessor">#endif </span><span class="comment">/* UIP_ACTIVE_OPEN */</span>
<a name="l00470"></a>00470 <span class="comment">/*---------------------------------------------------------------------------*/</span>
<a name="l00471"></a>00471 <span class="preprocessor">#if UIP_UDP</span>
<a name="l00472"></a>00472 <span class="preprocessor"></span><span class="keyword">struct </span><a class="code" href="a00150.html#g210f227119fc972e6222c9cb452e15a9">uip_udp_conn</a> *
<a name="l00473"></a><a class="code" href="a00150.html#g79c4110211247df3fb30b8cf1c4c02af">00473</a> <a class="code" href="a00147.html#g79c4110211247df3fb30b8cf1c4c02af">uip_udp_new</a>(<a class="code" href="a00150.html#g1ef35301f43a5bbb9f89f07b5a36b9a0">uip_ipaddr_t</a> *<a class="code" href="a00095.html#8a661a2d544100b82d0d14a1985083d5">ripaddr</a>, <a class="code" href="a00153.html#g77570ac4fcab86864fa1916e55676da2">u16_t</a> <a class="code" href="a00095.html#280a0c2a93544e597f92bbacf36ee1dc">rport</a>)
<a name="l00474"></a>00474 {
<a name="l00475"></a>00475   <span class="keyword">register</span> <span class="keyword">struct </span><a class="code" href="a00150.html#g210f227119fc972e6222c9cb452e15a9">uip_udp_conn</a> *conn;
<a name="l00476"></a>00476   
<a name="l00477"></a>00477   <span class="comment">/* Find an unused local port. */</span>
<a name="l00478"></a>00478  again:
<a name="l00479"></a>00479   ++lastport;
<a name="l00480"></a>00480 
<a name="l00481"></a>00481   <span class="keywordflow">if</span>(lastport &gt;= 32000) {
<a name="l00482"></a>00482     lastport = 4096;
<a name="l00483"></a>00483   }
<a name="l00484"></a>00484   
<a name="l00485"></a>00485   <span class="keywordflow">for</span>(c = 0; c &lt; <a class="code" href="a00153.html#g196379ceb1219a99f4495e41ccc9bbfb">UIP_UDP_CONNS</a>; ++c) {
<a name="l00486"></a>00486     <span class="keywordflow">if</span>(<a class="code" href="a00150.html#geb533744817cf6695d75293369c2248b">uip_udp_conns</a>[c].<a class="code" href="a00095.html#981392e295db4d024eea95805c51c371">lport</a> == <a class="code" href="a00148.html#ga22b04cac8cf283ca12f028578bebc06">htons</a>(lastport)) {
<a name="l00487"></a>00487       <span class="keywordflow">goto</span> again;
<a name="l00488"></a>00488     }
<a name="l00489"></a>00489   }
<a name="l00490"></a>00490 
<a name="l00491"></a>00491 
<a name="l00492"></a>00492   conn = 0;
<a name="l00493"></a>00493   <span class="keywordflow">for</span>(c = 0; c &lt; <a class="code" href="a00153.html#g196379ceb1219a99f4495e41ccc9bbfb">UIP_UDP_CONNS</a>; ++c) {
<a name="l00494"></a>00494     <span class="keywordflow">if</span>(<a class="code" href="a00150.html#geb533744817cf6695d75293369c2248b">uip_udp_conns</a>[c].<a class="code" href="a00095.html#981392e295db4d024eea95805c51c371">lport</a> == 0) {
<a name="l00495"></a>00495       conn = &amp;<a class="code" href="a00150.html#geb533744817cf6695d75293369c2248b">uip_udp_conns</a>[c];
<a name="l00496"></a>00496       <span class="keywordflow">break</span>;
<a name="l00497"></a>00497     }
<a name="l00498"></a>00498   }
<a name="l00499"></a>00499 
<a name="l00500"></a>00500   <span class="keywordflow">if</span>(conn == 0) {
<a name="l00501"></a>00501     <span class="keywordflow">return</span> 0;
<a name="l00502"></a>00502   }
<a name="l00503"></a>00503   
<a name="l00504"></a>00504   conn-&gt;<a class="code" href="a00095.html#981392e295db4d024eea95805c51c371">lport</a> = <a class="code" href="a00148.html#g69a7a4951ff21b302267532c21ee78fc">HTONS</a>(lastport);
<a name="l00505"></a>00505   conn-&gt;rport = <a class="code" href="a00095.html#280a0c2a93544e597f92bbacf36ee1dc">rport</a>;
<a name="l00506"></a>00506   <span class="keywordflow">if</span>(<a class="code" href="a00095.html#8a661a2d544100b82d0d14a1985083d5">ripaddr</a> == <a class="code" href="a00160.html#g070d2ce7b6bb7e5c05602aa8c308d0c4">NULL</a>) {
<a name="l00507"></a>00507     memset(conn-&gt;ripaddr, 0, <span class="keyword">sizeof</span>(<a class="code" href="a00150.html#g1ef35301f43a5bbb9f89f07b5a36b9a0">uip_ipaddr_t</a>));
<a name="l00508"></a>00508   } <span class="keywordflow">else</span> {
<a name="l00509"></a>00509     <a class="code" href="a00148.html#g769512993b7b27271909d6daa4748b60">uip_ipaddr_copy</a>(&amp;conn-&gt;ripaddr, <a class="code" href="a00095.html#8a661a2d544100b82d0d14a1985083d5">ripaddr</a>);
<a name="l00510"></a>00510   }
<a name="l00511"></a>00511   conn-&gt;ttl = <a class="code" href="a00153.html#gb61381673de27f31848c5396bf0b338e">UIP_TTL</a>;
<a name="l00512"></a>00512   
<a name="l00513"></a>00513   <span class="keywordflow">return</span> conn;
<a name="l00514"></a>00514 }
<a name="l00515"></a>00515 <span class="preprocessor">#endif </span><span class="comment">/* UIP_UDP */</span>
<a name="l00516"></a>00516 <span class="comment">/*---------------------------------------------------------------------------*/</span>
<a name="l00517"></a>00517 <span class="keywordtype">void</span>
<a name="l00518"></a><a class="code" href="a00150.html#gaa585784b0914cac1d37f07f85457008">00518</a> <a class="code" href="a00147.html#gaa585784b0914cac1d37f07f85457008">uip_unlisten</a>(<a class="code" href="a00153.html#g77570ac4fcab86864fa1916e55676da2">u16_t</a> port)
<a name="l00519"></a>00519 {
<a name="l00520"></a>00520   <span class="keywordflow">for</span>(c = 0; c &lt; <a class="code" href="a00153.html#g8f4ebd8ef6c0ea665ed351d87fec09fd">UIP_LISTENPORTS</a>; ++c) {
<a name="l00521"></a>00521     <span class="keywordflow">if</span>(uip_listenports[c] == port) {
<a name="l00522"></a>00522       uip_listenports[c] = 0;
<a name="l00523"></a>00523       <span class="keywordflow">return</span>;
<a name="l00524"></a>00524     }
<a name="l00525"></a>00525   }
<a name="l00526"></a>00526 }
<a name="l00527"></a>00527 <span class="comment">/*---------------------------------------------------------------------------*/</span>
<a name="l00528"></a>00528 <span class="keywordtype">void</span>
<a name="l00529"></a><a class="code" href="a00150.html#gdd1ab3704ecd4900eec61a6897d32dc8">00529</a> <a class="code" href="a00147.html#gdd1ab3704ecd4900eec61a6897d32dc8">uip_listen</a>(<a class="code" href="a00153.html#g77570ac4fcab86864fa1916e55676da2">u16_t</a> port)
<a name="l00530"></a>00530 {
<a name="l00531"></a>00531   <span class="keywordflow">for</span>(c = 0; c &lt; <a class="code" href="a00153.html#g8f4ebd8ef6c0ea665ed351d87fec09fd">UIP_LISTENPORTS</a>; ++c) {
<a name="l00532"></a>00532     <span class="keywordflow">if</span>(uip_listenports[c] == 0) {
<a name="l00533"></a>00533       uip_listenports[c] = port;
<a name="l00534"></a>00534       <span class="keywordflow">return</span>;
<a name="l00535"></a>00535     }
<a name="l00536"></a>00536   }
<a name="l00537"></a>00537 }
<a name="l00538"></a>00538 <span class="comment">/*---------------------------------------------------------------------------*/</span>
<a name="l00539"></a>00539 <span class="comment">/* XXX: IP fragment reassembly: not well-tested. */</span>
<a name="l00540"></a>00540 
<a name="l00541"></a>00541 <span class="preprocessor">#if UIP_REASSEMBLY &amp;&amp; !UIP_CONF_IPV6</span>
<a name="l00542"></a>00542 <span class="preprocessor"></span><span class="preprocessor">#define UIP_REASS_BUFSIZE (UIP_BUFSIZE - UIP_LLH_LEN)</span>
<a name="l00543"></a>00543 <span class="preprocessor"></span><span class="keyword">static</span> <a class="code" href="a00153.html#g4caecabca98b43919dd11be1c0d4cd8e">u8_t</a> uip_reassbuf[UIP_REASS_BUFSIZE];
<a name="l00544"></a>00544 <span class="keyword">static</span> <a class="code" href="a00153.html#g4caecabca98b43919dd11be1c0d4cd8e">u8_t</a> uip_reassbitmap[UIP_REASS_BUFSIZE / (8 * 8)];
<a name="l00545"></a>00545 <span class="keyword">static</span> <span class="keyword">const</span> <a class="code" href="a00153.html#g4caecabca98b43919dd11be1c0d4cd8e">u8_t</a> bitmap_bits[8] = {0xff, 0x7f, 0x3f, 0x1f,
<a name="l00546"></a>00546                                     0x0f, 0x07, 0x03, 0x01};
<a name="l00547"></a>00547 <span class="keyword">static</span> <a class="code" href="a00153.html#g77570ac4fcab86864fa1916e55676da2">u16_t</a> uip_reasslen;
<a name="l00548"></a>00548 <span class="keyword">static</span> <a class="code" href="a00153.html#g4caecabca98b43919dd11be1c0d4cd8e">u8_t</a> uip_reassflags;
<a name="l00549"></a>00549 <span class="preprocessor">#define UIP_REASS_FLAG_LASTFRAG 0x01</span>
<a name="l00550"></a>00550 <span class="preprocessor"></span><span class="keyword">static</span> <a class="code" href="a00153.html#g4caecabca98b43919dd11be1c0d4cd8e">u8_t</a> uip_reasstmr;
<a name="l00551"></a>00551 
<a name="l00552"></a>00552 <span class="preprocessor">#define IP_MF   0x20</span>
<a name="l00553"></a>00553 <span class="preprocessor"></span>
<a name="l00554"></a>00554 <span class="keyword">static</span> <a class="code" href="a00153.html#g4caecabca98b43919dd11be1c0d4cd8e">u8_t</a>
<a name="l00555"></a>00555 uip_reass(<span class="keywordtype">void</span>)
<a name="l00556"></a>00556 {
<a name="l00557"></a>00557   <a class="code" href="a00153.html#g77570ac4fcab86864fa1916e55676da2">u16_t</a> offset, len;
<a name="l00558"></a>00558   <a class="code" href="a00153.html#g77570ac4fcab86864fa1916e55676da2">u16_t</a> i;
<a name="l00559"></a>00559 
<a name="l00560"></a>00560   <span class="comment">/* If ip_reasstmr is zero, no packet is present in the buffer, so we</span>
<a name="l00561"></a>00561 <span class="comment">     write the IP header of the fragment into the reassembly</span>
<a name="l00562"></a>00562 <span class="comment">     buffer. The timer is updated with the maximum age. */</span>
<a name="l00563"></a>00563   <span class="keywordflow">if</span>(uip_reasstmr == 0) {
<a name="l00564"></a>00564     memcpy(uip_reassbuf, &amp;<a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;vhl, <a class="code" href="a00150.html#g6bc12c6c7b56f73ce5d57abfdcdc6eb5">UIP_IPH_LEN</a>);
<a name="l00565"></a>00565     uip_reasstmr = <a class="code" href="a00153.html#gc3882366feda1cb759ccbfe98327a7db">UIP_REASS_MAXAGE</a>;
<a name="l00566"></a>00566     uip_reassflags = 0;
<a name="l00567"></a>00567     <span class="comment">/* Clear the bitmap. */</span>
<a name="l00568"></a>00568     memset(uip_reassbitmap, 0, <span class="keyword">sizeof</span>(uip_reassbitmap));
<a name="l00569"></a>00569   }
<a name="l00570"></a>00570 
<a name="l00571"></a>00571   <span class="comment">/* Check if the incoming fragment matches the one currently present</span>
<a name="l00572"></a>00572 <span class="comment">     in the reasembly buffer. If so, we proceed with copying the</span>
<a name="l00573"></a>00573 <span class="comment">     fragment into the buffer. */</span>
<a name="l00574"></a>00574   <span class="keywordflow">if</span>(<a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;srcipaddr[0] == <a class="code" href="a00150.html#g96544dedc1cdc71ad2ad54bf1d5e5433">FBUF</a>-&gt;srcipaddr[0] &amp;&amp;
<a name="l00575"></a>00575      <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;srcipaddr[1] == <a class="code" href="a00150.html#g96544dedc1cdc71ad2ad54bf1d5e5433">FBUF</a>-&gt;srcipaddr[1] &amp;&amp;
<a name="l00576"></a>00576      <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;destipaddr[0] == <a class="code" href="a00150.html#g96544dedc1cdc71ad2ad54bf1d5e5433">FBUF</a>-&gt;destipaddr[0] &amp;&amp;
<a name="l00577"></a>00577      <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;destipaddr[1] == <a class="code" href="a00150.html#g96544dedc1cdc71ad2ad54bf1d5e5433">FBUF</a>-&gt;destipaddr[1] &amp;&amp;
<a name="l00578"></a>00578      <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;ipid[0] == <a class="code" href="a00150.html#g96544dedc1cdc71ad2ad54bf1d5e5433">FBUF</a>-&gt;ipid[0] &amp;&amp;
<a name="l00579"></a>00579      <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;ipid[1] == <a class="code" href="a00150.html#g96544dedc1cdc71ad2ad54bf1d5e5433">FBUF</a>-&gt;ipid[1]) {
<a name="l00580"></a>00580 
<a name="l00581"></a>00581     len = (<a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;len[0] &lt;&lt; 8) + <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;len[1] - (<a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;vhl &amp; 0x0f) * 4;
<a name="l00582"></a>00582     offset = (((<a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;ipoffset[0] &amp; 0x3f) &lt;&lt; 8) + <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;ipoffset[1]) * 8;
<a name="l00583"></a>00583 
<a name="l00584"></a>00584     <span class="comment">/* If the offset or the offset + fragment length overflows the</span>
<a name="l00585"></a>00585 <span class="comment">       reassembly buffer, we discard the entire packet. */</span>
<a name="l00586"></a>00586     <span class="keywordflow">if</span>(offset &gt; UIP_REASS_BUFSIZE ||
<a name="l00587"></a>00587        offset + len &gt; UIP_REASS_BUFSIZE) {
<a name="l00588"></a>00588       uip_reasstmr = 0;
<a name="l00589"></a>00589       <span class="keywordflow">goto</span> nullreturn;
<a name="l00590"></a>00590     }
<a name="l00591"></a>00591 
<a name="l00592"></a>00592     <span class="comment">/* Copy the fragment into the reassembly buffer, at the right</span>
<a name="l00593"></a>00593 <span class="comment">       offset. */</span>
<a name="l00594"></a>00594     memcpy(&amp;uip_reassbuf[<a class="code" href="a00150.html#g6bc12c6c7b56f73ce5d57abfdcdc6eb5">UIP_IPH_LEN</a> + offset],
<a name="l00595"></a>00595            (<span class="keywordtype">char</span> *)<a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a> + (<span class="keywordtype">int</span>)((<a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;vhl &amp; 0x0f) * 4),
<a name="l00596"></a>00596            len);
<a name="l00597"></a>00597       
<a name="l00598"></a>00598     <span class="comment">/* Update the bitmap. */</span>
<a name="l00599"></a>00599     <span class="keywordflow">if</span>(offset / (8 * 8) == (offset + len) / (8 * 8)) {
<a name="l00600"></a>00600       <span class="comment">/* If the two endpoints are in the same byte, we only update</span>
<a name="l00601"></a>00601 <span class="comment">         that byte. */</span>
<a name="l00602"></a>00602              
<a name="l00603"></a>00603       uip_reassbitmap[offset / (8 * 8)] |=
<a name="l00604"></a>00604              bitmap_bits[(offset / 8 ) &amp; 7] &amp;
<a name="l00605"></a>00605              ~bitmap_bits[((offset + len) / 8 ) &amp; 7];
<a name="l00606"></a>00606     } <span class="keywordflow">else</span> {
<a name="l00607"></a>00607       <span class="comment">/* If the two endpoints are in different bytes, we update the</span>
<a name="l00608"></a>00608 <span class="comment">         bytes in the endpoints and fill the stuff inbetween with</span>
<a name="l00609"></a>00609 <span class="comment">         0xff. */</span>
<a name="l00610"></a>00610       uip_reassbitmap[offset / (8 * 8)] |=
<a name="l00611"></a>00611         bitmap_bits[(offset / 8 ) &amp; 7];
<a name="l00612"></a>00612       <span class="keywordflow">for</span>(i = 1 + offset / (8 * 8); i &lt; (offset + len) / (8 * 8); ++i) {
<a name="l00613"></a>00613         uip_reassbitmap[i] = 0xff;
<a name="l00614"></a>00614       }
<a name="l00615"></a>00615       uip_reassbitmap[(offset + len) / (8 * 8)] |=
<a name="l00616"></a>00616         ~bitmap_bits[((offset + len) / 8 ) &amp; 7];
<a name="l00617"></a>00617     }
<a name="l00618"></a>00618     
<a name="l00619"></a>00619     <span class="comment">/* If this fragment has the More Fragments flag set to zero, we</span>
<a name="l00620"></a>00620 <span class="comment">       know that this is the last fragment, so we can calculate the</span>
<a name="l00621"></a>00621 <span class="comment">       size of the entire packet. We also set the</span>
<a name="l00622"></a>00622 <span class="comment">       IP_REASS_FLAG_LASTFRAG flag to indicate that we have received</span>
<a name="l00623"></a>00623 <span class="comment">       the final fragment. */</span>
<a name="l00624"></a>00624 
<a name="l00625"></a>00625     <span class="keywordflow">if</span>((<a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;ipoffset[0] &amp; IP_MF) == 0) {
<a name="l00626"></a>00626       uip_reassflags |= UIP_REASS_FLAG_LASTFRAG;
<a name="l00627"></a>00627       uip_reasslen = offset + len;
<a name="l00628"></a>00628     }
<a name="l00629"></a>00629     
<a name="l00630"></a>00630     <span class="comment">/* Finally, we check if we have a full packet in the buffer. We do</span>
<a name="l00631"></a>00631 <span class="comment">       this by checking if we have the last fragment and if all bits</span>
<a name="l00632"></a>00632 <span class="comment">       in the bitmap are set. */</span>
<a name="l00633"></a>00633     <span class="keywordflow">if</span>(uip_reassflags &amp; UIP_REASS_FLAG_LASTFRAG) {
<a name="l00634"></a>00634       <span class="comment">/* Check all bytes up to and including all but the last byte in</span>
<a name="l00635"></a>00635 <span class="comment">         the bitmap. */</span>
<a name="l00636"></a>00636       <span class="keywordflow">for</span>(i = 0; i &lt; uip_reasslen / (8 * 8) - 1; ++i) {
<a name="l00637"></a>00637         <span class="keywordflow">if</span>(uip_reassbitmap[i] != 0xff) {
<a name="l00638"></a>00638           <span class="keywordflow">goto</span> nullreturn;
<a name="l00639"></a>00639         }
<a name="l00640"></a>00640       }
<a name="l00641"></a>00641       <span class="comment">/* Check the last byte in the bitmap. It should contain just the</span>
<a name="l00642"></a>00642 <span class="comment">         right amount of bits. */</span>
<a name="l00643"></a>00643       <span class="keywordflow">if</span>(uip_reassbitmap[uip_reasslen / (8 * 8)] !=
<a name="l00644"></a>00644          (<a class="code" href="a00153.html#g4caecabca98b43919dd11be1c0d4cd8e">u8_t</a>)~bitmap_bits[uip_reasslen / 8 &amp; 7]) {
<a name="l00645"></a>00645         <span class="keywordflow">goto</span> nullreturn;
<a name="l00646"></a>00646       }
<a name="l00647"></a>00647 
<a name="l00648"></a>00648       <span class="comment">/* If we have come this far, we have a full packet in the</span>
<a name="l00649"></a>00649 <span class="comment">         buffer, so we allocate a pbuf and copy the packet into it. We</span>
<a name="l00650"></a>00650 <span class="comment">         also reset the timer. */</span>
<a name="l00651"></a>00651       uip_reasstmr = 0;
<a name="l00652"></a>00652       memcpy(<a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>, <a class="code" href="a00150.html#g96544dedc1cdc71ad2ad54bf1d5e5433">FBUF</a>, uip_reasslen);
<a name="l00653"></a>00653 
<a name="l00654"></a>00654       <span class="comment">/* Pretend to be a "normal" (i.e., not fragmented) IP packet</span>
<a name="l00655"></a>00655 <span class="comment">         from now on. */</span>
<a name="l00656"></a>00656       <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;ipoffset[0] = <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;ipoffset[1] = 0;
<a name="l00657"></a>00657       <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;len[0] = uip_reasslen &gt;&gt; 8;
<a name="l00658"></a>00658       <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;len[1] = uip_reasslen &amp; 0xff;
<a name="l00659"></a>00659       <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;ipchksum = 0;
<a name="l00660"></a>00660       <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;ipchksum = ~(<a class="code" href="a00150.html#g2addf34c7d457c1a7899a7e2171ef1e9">uip_ipchksum</a>());
<a name="l00661"></a>00661 
<a name="l00662"></a>00662       <span class="keywordflow">return</span> uip_reasslen;
<a name="l00663"></a>00663     }
<a name="l00664"></a>00664   }
<a name="l00665"></a>00665 
<a name="l00666"></a>00666  nullreturn:
<a name="l00667"></a>00667   <span class="keywordflow">return</span> 0;
<a name="l00668"></a>00668 }
<a name="l00669"></a>00669 <span class="preprocessor">#endif </span><span class="comment">/* UIP_REASSEMBLY */</span>
<a name="l00670"></a>00670 <span class="comment">/*---------------------------------------------------------------------------*/</span>
<a name="l00671"></a>00671 <span class="keyword">static</span> <span class="keywordtype">void</span>
<a name="l00672"></a>00672 uip_add_rcv_nxt(<a class="code" href="a00153.html#g77570ac4fcab86864fa1916e55676da2">u16_t</a> n)
<a name="l00673"></a>00673 {
<a name="l00674"></a>00674   <a class="code" href="a00150.html#g6832e4d2d046536b6472f7ac92340f68">uip_add32</a>(<a class="code" href="a00088.html">uip_conn</a>-&gt;rcv_nxt, n);
<a name="l00675"></a>00675   <a class="code" href="a00088.html">uip_conn</a>-&gt;rcv_nxt[0] = <a class="code" href="a00151.html#g2a0cf5d86c58fab216414ce59bf1fea1">uip_acc32</a>[0];
<a name="l00676"></a>00676   <a class="code" href="a00088.html">uip_conn</a>-&gt;rcv_nxt[1] = <a class="code" href="a00151.html#g2a0cf5d86c58fab216414ce59bf1fea1">uip_acc32</a>[1];
<a name="l00677"></a>00677   <a class="code" href="a00088.html">uip_conn</a>-&gt;rcv_nxt[2] = <a class="code" href="a00151.html#g2a0cf5d86c58fab216414ce59bf1fea1">uip_acc32</a>[2];
<a name="l00678"></a>00678   <a class="code" href="a00088.html">uip_conn</a>-&gt;rcv_nxt[3] = <a class="code" href="a00151.html#g2a0cf5d86c58fab216414ce59bf1fea1">uip_acc32</a>[3];
<a name="l00679"></a>00679 }
<a name="l00680"></a>00680 <span class="comment">/*---------------------------------------------------------------------------*/</span>
<a name="l00681"></a>00681 <span class="keywordtype">void</span>
<a name="l00682"></a><a class="code" href="a00150.html#g266263ac78a1361a2b1d15741d3b0675">00682</a> <a class="code" href="a00150.html#g266263ac78a1361a2b1d15741d3b0675">uip_process</a>(<a class="code" href="a00153.html#g4caecabca98b43919dd11be1c0d4cd8e">u8_t</a> flag)
<a name="l00683"></a>00683 {
<a name="l00684"></a>00684   <span class="keyword">register</span> <span class="keyword">struct </span><a class="code" href="a00088.html">uip_conn</a> *uip_connr = <a class="code" href="a00088.html">uip_conn</a>;
<a name="l00685"></a>00685 
<a name="l00686"></a>00686 <span class="preprocessor">#if UIP_UDP</span>
<a name="l00687"></a>00687 <span class="preprocessor"></span>  <span class="keywordflow">if</span>(flag == <a class="code" href="a00150.html#g5c97ae587595b5444be80f5ecc1d3382">UIP_UDP_SEND_CONN</a>) {
<a name="l00688"></a>00688     <span class="keywordflow">goto</span> udp_send;
<a name="l00689"></a>00689   }
<a name="l00690"></a>00690 <span class="preprocessor">#endif </span><span class="comment">/* UIP_UDP */</span>
<a name="l00691"></a>00691   
<a name="l00692"></a>00692   <a class="code" href="a00150.html#ga05a3dde2048480fa3ab2a5961898d18">uip_sappdata</a> = <a class="code" href="a00150.html#g561b8eda32e059d4e7397f776268cc63">uip_appdata</a> = &amp;<a class="code" href="a00146.html#gb81e78f890dbbee50c533a9734b74fd9">uip_buf</a>[<a class="code" href="a00150.html#g15f2617f7dc1713f9d10282125c6027b">UIP_IPTCPH_LEN</a> + <a class="code" href="a00153.html#ge6f4a2453dbd8bc60e6a82774552366a">UIP_LLH_LEN</a>];
<a name="l00693"></a>00693 
<a name="l00694"></a>00694   <span class="comment">/* Check if we were invoked because of a poll request for a</span>
<a name="l00695"></a>00695 <span class="comment">     particular connection. */</span>
<a name="l00696"></a>00696   <span class="keywordflow">if</span>(flag == <a class="code" href="a00150.html#gd605357e29affb0d3104294c90f09905">UIP_POLL_REQUEST</a>) {
<a name="l00697"></a>00697     <span class="keywordflow">if</span>((uip_connr-&gt;<a class="code" href="a00088.html#a5f58074435cdc180f17de69651beebd">tcpstateflags</a> &amp; <a class="code" href="a00150.html#g13dfcb4a5f920e108253ade527a66cc2">UIP_TS_MASK</a>) == <a class="code" href="a00150.html#gae59b70658f28ee6e998eaaab05e423f">UIP_ESTABLISHED</a> &amp;&amp;
<a name="l00698"></a>00698        !<a class="code" href="a00147.html#gef14e83c046e19ab9fe9d1bbcca276c2">uip_outstanding</a>(uip_connr)) {
<a name="l00699"></a>00699         <a class="code" href="a00150.html#gb4ef6b00924990e7a293f66715b6d1d1">uip_flags</a> = <a class="code" href="a00150.html#gf0ed78fd2be24d849cdd5af75e3b2674">UIP_POLL</a>;
<a name="l00700"></a>00700         <a class="code" href="a00153.html#g41aa744caa46913b3b3aedb2a4e78546">UIP_APPCALL</a>();
<a name="l00701"></a>00701         <span class="keywordflow">goto</span> appsend;
<a name="l00702"></a>00702     }
<a name="l00703"></a>00703     <span class="keywordflow">goto</span> drop;
<a name="l00704"></a>00704     
<a name="l00705"></a>00705     <span class="comment">/* Check if we were invoked because of the perodic timer fireing. */</span>
<a name="l00706"></a>00706   } <span class="keywordflow">else</span> <span class="keywordflow">if</span>(flag == <a class="code" href="a00150.html#g041aea91aa6ef84dcc6cac3c51db9b2f">UIP_TIMER</a>) {
<a name="l00707"></a>00707 <span class="preprocessor">#if UIP_REASSEMBLY</span>
<a name="l00708"></a>00708 <span class="preprocessor"></span>    <span class="keywordflow">if</span>(uip_reasstmr != 0) {
<a name="l00709"></a>00709       --uip_reasstmr;
<a name="l00710"></a>00710     }
<a name="l00711"></a>00711 <span class="preprocessor">#endif </span><span class="comment">/* UIP_REASSEMBLY */</span>
<a name="l00712"></a>00712     <span class="comment">/* Increase the initial sequence number. */</span>
<a name="l00713"></a>00713     <span class="keywordflow">if</span>(++iss[3] == 0) {
<a name="l00714"></a>00714       <span class="keywordflow">if</span>(++iss[2] == 0) {
<a name="l00715"></a>00715         <span class="keywordflow">if</span>(++iss[1] == 0) {
<a name="l00716"></a>00716           ++iss[0];
<a name="l00717"></a>00717         }
<a name="l00718"></a>00718       }
<a name="l00719"></a>00719     }
<a name="l00720"></a>00720 
<a name="l00721"></a>00721     <span class="comment">/* Reset the length variables. */</span>
<a name="l00722"></a>00722     <a class="code" href="a00149.html#g12a33f0c09711167bdf3dd7d7cf8c5a1">uip_len</a> = 0;
<a name="l00723"></a>00723     <a class="code" href="a00150.html#g5b5615dc240daed20949c0fded2b4679">uip_slen</a> = 0;
<a name="l00724"></a>00724 
<a name="l00725"></a>00725     <span class="comment">/* Check if the connection is in a state in which we simply wait</span>
<a name="l00726"></a>00726 <span class="comment">       for the connection to time out. If so, we increase the</span>
<a name="l00727"></a>00727 <span class="comment">       connection's timer and remove the connection if it times</span>
<a name="l00728"></a>00728 <span class="comment">       out. */</span>
<a name="l00729"></a>00729     <span class="keywordflow">if</span>(uip_connr-&gt;<a class="code" href="a00088.html#a5f58074435cdc180f17de69651beebd">tcpstateflags</a> == <a class="code" href="a00150.html#gfff0ed43201bf1e2020de1a0d6cac070">UIP_TIME_WAIT</a> ||
<a name="l00730"></a>00730        uip_connr-&gt;<a class="code" href="a00088.html#a5f58074435cdc180f17de69651beebd">tcpstateflags</a> == <a class="code" href="a00150.html#g160128ab5d2ea3cc497b91ee4eb4ef99">UIP_FIN_WAIT_2</a>) {
<a name="l00731"></a>00731       ++(uip_connr-&gt;<a class="code" href="a00088.html#2d9732cf5752d30bd11cb25dc7d0c8d3">timer</a>);
<a name="l00732"></a>00732       <span class="keywordflow">if</span>(uip_connr-&gt;<a class="code" href="a00088.html#2d9732cf5752d30bd11cb25dc7d0c8d3">timer</a> == <a class="code" href="a00153.html#g2bc3b489923793759526a3181eb667fa">UIP_TIME_WAIT_TIMEOUT</a>) {
<a name="l00733"></a>00733         uip_connr-&gt;<a class="code" href="a00088.html#a5f58074435cdc180f17de69651beebd">tcpstateflags</a> = <a class="code" href="a00150.html#g28eda870cff3d8e3cf2949e6f57a502b">UIP_CLOSED</a>;
<a name="l00734"></a>00734       }
<a name="l00735"></a>00735     } <span class="keywordflow">else</span> <span class="keywordflow">if</span>(uip_connr-&gt;<a class="code" href="a00088.html#a5f58074435cdc180f17de69651beebd">tcpstateflags</a> != <a class="code" href="a00150.html#g28eda870cff3d8e3cf2949e6f57a502b">UIP_CLOSED</a>) {
<a name="l00736"></a>00736       <span class="comment">/* If the connection has outstanding data, we increase the</span>
<a name="l00737"></a>00737 <span class="comment">         connection's timer and see if it has reached the RTO value</span>
<a name="l00738"></a>00738 <span class="comment">         in which case we retransmit. */</span>
<a name="l00739"></a>00739       <span class="keywordflow">if</span>(<a class="code" href="a00147.html#gef14e83c046e19ab9fe9d1bbcca276c2">uip_outstanding</a>(uip_connr)) {
<a name="l00740"></a>00740         <span class="keywordflow">if</span>(uip_connr-&gt;timer-- == 0) {
<a name="l00741"></a>00741           <span class="keywordflow">if</span>(uip_connr-&gt;nrtx == <a class="code" href="a00153.html#g67cf1e0d2324c93f332c1f020c0fe8b3">UIP_MAXRTX</a> ||
<a name="l00742"></a>00742              ((uip_connr-&gt;tcpstateflags == <a class="code" href="a00150.html#g8af482dec973db57d8b3bd3f69461488">UIP_SYN_SENT</a> ||
<a name="l00743"></a>00743                uip_connr-&gt;tcpstateflags == <a class="code" href="a00150.html#ga5e3c856b86725125d19fccc34cd9eb5">UIP_SYN_RCVD</a>) &amp;&amp;
<a name="l00744"></a>00744               uip_connr-&gt;nrtx == <a class="code" href="a00153.html#g24aa5bc36939cc9a0833e1df01478a7e">UIP_MAXSYNRTX</a>)) {
<a name="l00745"></a>00745             uip_connr-&gt;tcpstateflags = <a class="code" href="a00150.html#g28eda870cff3d8e3cf2949e6f57a502b">UIP_CLOSED</a>;
<a name="l00746"></a>00746 
<a name="l00747"></a>00747             <span class="comment">/* We call UIP_APPCALL() with uip_flags set to</span>
<a name="l00748"></a>00748 <span class="comment">               UIP_TIMEDOUT to inform the application that the</span>
<a name="l00749"></a>00749 <span class="comment">               connection has timed out. */</span>
<a name="l00750"></a>00750             <a class="code" href="a00150.html#gb4ef6b00924990e7a293f66715b6d1d1">uip_flags</a> = <a class="code" href="a00150.html#g2d3ba4b14d6d2f6576f9b547800b7945">UIP_TIMEDOUT</a>;
<a name="l00751"></a>00751             <a class="code" href="a00153.html#g41aa744caa46913b3b3aedb2a4e78546">UIP_APPCALL</a>();
<a name="l00752"></a>00752 
<a name="l00753"></a>00753             <span class="comment">/* We also send a reset packet to the remote host. */</span>
<a name="l00754"></a>00754             <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;flags = <a class="code" href="a00150.html#g5ca559def464ef20d8b1f7d32f2f160d">TCP_RST</a> | <a class="code" href="a00150.html#g44b3b1ab31a403ba28ec135adfcbefef">TCP_ACK</a>;
<a name="l00755"></a>00755             <span class="keywordflow">goto</span> tcp_send_nodata;
<a name="l00756"></a>00756           }
<a name="l00757"></a>00757 
<a name="l00758"></a>00758           <span class="comment">/* Exponential backoff. */</span>
<a name="l00759"></a>00759           uip_connr-&gt;timer = <a class="code" href="a00153.html#g15de27b044603284f68db05a378235a7">UIP_RTO</a> &lt;&lt; (uip_connr-&gt;nrtx &gt; 4?
<a name="l00760"></a>00760                                          4:
<a name="l00761"></a>00761                                          uip_connr-&gt;nrtx);
<a name="l00762"></a>00762           ++(uip_connr-&gt;nrtx);
<a name="l00763"></a>00763           
<a name="l00764"></a>00764           <span class="comment">/* Ok, so we need to retransmit. We do this differently</span>
<a name="l00765"></a>00765 <span class="comment">             depending on which state we are in. In ESTABLISHED, we</span>
<a name="l00766"></a>00766 <span class="comment">             call upon the application so that it may prepare the</span>
<a name="l00767"></a>00767 <span class="comment">             data for the retransmit. In SYN_RCVD, we resend the</span>
<a name="l00768"></a>00768 <span class="comment">             SYNACK that we sent earlier and in LAST_ACK we have to</span>
<a name="l00769"></a>00769 <span class="comment">             retransmit our FINACK. */</span>
<a name="l00770"></a>00770           <a class="code" href="a00150.html#g9c0814ed491fa452ec97910c0728d410">UIP_STAT</a>(++<a class="code" href="a00150.html#g9ee50a40597e67fce96541ab56c3b712">uip_stat</a>.<a class="code" href="a00093.html#e292b8977f6b81265bf14e1676face3e">tcp</a>.<a class="code" href="a00093.html#3ad48284f7a91f78bb24096aad89056e">rexmit</a>);
<a name="l00771"></a>00771           <span class="keywordflow">switch</span>(uip_connr-&gt;tcpstateflags &amp; <a class="code" href="a00150.html#g13dfcb4a5f920e108253ade527a66cc2">UIP_TS_MASK</a>) {
<a name="l00772"></a>00772           <span class="keywordflow">case</span> <a class="code" href="a00150.html#ga5e3c856b86725125d19fccc34cd9eb5">UIP_SYN_RCVD</a>:
<a name="l00773"></a>00773             <span class="comment">/* In the SYN_RCVD state, we should retransmit our</span>
<a name="l00774"></a>00774 <span class="comment">               SYNACK. */</span>
<a name="l00775"></a>00775             <span class="keywordflow">goto</span> tcp_send_synack;
<a name="l00776"></a>00776             
<a name="l00777"></a>00777 <span class="preprocessor">#if UIP_ACTIVE_OPEN</span>
<a name="l00778"></a>00778 <span class="preprocessor"></span>          <span class="keywordflow">case</span> <a class="code" href="a00150.html#g8af482dec973db57d8b3bd3f69461488">UIP_SYN_SENT</a>:
<a name="l00779"></a>00779             <span class="comment">/* In the SYN_SENT state, we retransmit out SYN. */</span>
<a name="l00780"></a>00780             <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;flags = 0;
<a name="l00781"></a>00781             <span class="keywordflow">goto</span> tcp_send_syn;
<a name="l00782"></a>00782 <span class="preprocessor">#endif </span><span class="comment">/* UIP_ACTIVE_OPEN */</span>
<a name="l00783"></a>00783             
<a name="l00784"></a>00784           <span class="keywordflow">case</span> <a class="code" href="a00150.html#gae59b70658f28ee6e998eaaab05e423f">UIP_ESTABLISHED</a>:
<a name="l00785"></a>00785             <span class="comment">/* In the ESTABLISHED state, we call upon the application</span>
<a name="l00786"></a>00786 <span class="comment">               to do the actual retransmit after which we jump into</span>
<a name="l00787"></a>00787 <span class="comment">               the code for sending out the packet (the apprexmit</span>
<a name="l00788"></a>00788 <span class="comment">               label). */</span>
<a name="l00789"></a>00789             <a class="code" href="a00150.html#gb4ef6b00924990e7a293f66715b6d1d1">uip_flags</a> = <a class="code" href="a00150.html#gf848ce44c810492e7a35c2d23a429f45">UIP_REXMIT</a>;
<a name="l00790"></a>00790             <a class="code" href="a00153.html#g41aa744caa46913b3b3aedb2a4e78546">UIP_APPCALL</a>();
<a name="l00791"></a>00791             <span class="keywordflow">goto</span> apprexmit;
<a name="l00792"></a>00792             
<a name="l00793"></a>00793           <span class="keywordflow">case</span> <a class="code" href="a00150.html#ga533c394b1fa0030205534befa31c525">UIP_FIN_WAIT_1</a>:
<a name="l00794"></a>00794           <span class="keywordflow">case</span> <a class="code" href="a00150.html#g64d9affc680a445d708234e70450477b">UIP_CLOSING</a>:
<a name="l00795"></a>00795           <span class="keywordflow">case</span> <a class="code" href="a00150.html#gd135fb0cfdfb2c212f0f51865a3640e4">UIP_LAST_ACK</a>:
<a name="l00796"></a>00796             <span class="comment">/* In all these states we should retransmit a FINACK. */</span>
<a name="l00797"></a>00797             <span class="keywordflow">goto</span> tcp_send_finack;
<a name="l00798"></a>00798             
<a name="l00799"></a>00799           }
<a name="l00800"></a>00800         }
<a name="l00801"></a>00801       } <span class="keywordflow">else</span> <span class="keywordflow">if</span>((uip_connr-&gt;tcpstateflags &amp; <a class="code" href="a00150.html#g13dfcb4a5f920e108253ade527a66cc2">UIP_TS_MASK</a>) == <a class="code" href="a00150.html#gae59b70658f28ee6e998eaaab05e423f">UIP_ESTABLISHED</a>) {
<a name="l00802"></a>00802         <span class="comment">/* If there was no need for a retransmission, we poll the</span>
<a name="l00803"></a>00803 <span class="comment">           application for new data. */</span>
<a name="l00804"></a>00804         <a class="code" href="a00150.html#gb4ef6b00924990e7a293f66715b6d1d1">uip_flags</a> = <a class="code" href="a00150.html#gf0ed78fd2be24d849cdd5af75e3b2674">UIP_POLL</a>;
<a name="l00805"></a>00805         <a class="code" href="a00153.html#g41aa744caa46913b3b3aedb2a4e78546">UIP_APPCALL</a>();
<a name="l00806"></a>00806         <span class="keywordflow">goto</span> appsend;
<a name="l00807"></a>00807       }
<a name="l00808"></a>00808     }
<a name="l00809"></a>00809     <span class="keywordflow">goto</span> drop;
<a name="l00810"></a>00810   }
<a name="l00811"></a>00811 <span class="preprocessor">#if UIP_UDP</span>
<a name="l00812"></a>00812 <span class="preprocessor"></span>  <span class="keywordflow">if</span>(flag == <a class="code" href="a00150.html#gf0ccbc3bb2a3ba1ebc255c7b3fcedd24">UIP_UDP_TIMER</a>) {
<a name="l00813"></a>00813     <span class="keywordflow">if</span>(<a class="code" href="a00095.html">uip_udp_conn</a>-&gt;lport != 0) {
<a name="l00814"></a>00814       <a class="code" href="a00088.html">uip_conn</a> = <a class="code" href="a00160.html#g070d2ce7b6bb7e5c05602aa8c308d0c4">NULL</a>;
<a name="l00815"></a>00815       <a class="code" href="a00150.html#ga05a3dde2048480fa3ab2a5961898d18">uip_sappdata</a> = <a class="code" href="a00150.html#g561b8eda32e059d4e7397f776268cc63">uip_appdata</a> = &amp;<a class="code" href="a00146.html#gb81e78f890dbbee50c533a9734b74fd9">uip_buf</a>[<a class="code" href="a00153.html#ge6f4a2453dbd8bc60e6a82774552366a">UIP_LLH_LEN</a> + <a class="code" href="a00150.html#g6f2b90c597ec23f39ec716ccec11233c">UIP_IPUDPH_LEN</a>];
<a name="l00816"></a>00816       <a class="code" href="a00149.html#g12a33f0c09711167bdf3dd7d7cf8c5a1">uip_len</a> = <a class="code" href="a00150.html#g5b5615dc240daed20949c0fded2b4679">uip_slen</a> = 0;
<a name="l00817"></a>00817       <a class="code" href="a00150.html#gb4ef6b00924990e7a293f66715b6d1d1">uip_flags</a> = <a class="code" href="a00150.html#gf0ed78fd2be24d849cdd5af75e3b2674">UIP_POLL</a>;
<a name="l00818"></a>00818       <a class="code" href="a00160.html#g3d768e989e308144190ae1a5ddfa9726">UIP_UDP_APPCALL</a>();
<a name="l00819"></a>00819       <span class="keywordflow">goto</span> udp_send;
<a name="l00820"></a>00820     } <span class="keywordflow">else</span> {
<a name="l00821"></a>00821       <span class="keywordflow">goto</span> drop;
<a name="l00822"></a>00822     }
<a name="l00823"></a>00823   }
<a name="l00824"></a>00824 <span class="preprocessor">#endif</span>
<a name="l00825"></a>00825 <span class="preprocessor"></span>
<a name="l00826"></a>00826   <span class="comment">/* This is where the input processing starts. */</span>
<a name="l00827"></a>00827   <a class="code" href="a00150.html#g9c0814ed491fa452ec97910c0728d410">UIP_STAT</a>(++<a class="code" href="a00150.html#g9ee50a40597e67fce96541ab56c3b712">uip_stat</a>.<a class="code" href="a00093.html#1deb2899508216804823498a69378118">ip</a>.<a class="code" href="a00093.html#7f7bb2145afba5df00c6e10ddefa8ae1">recv</a>);
<a name="l00828"></a>00828 
<a name="l00829"></a>00829   <span class="comment">/* Start of IP input header processing code. */</span>
<a name="l00830"></a>00830   
<a name="l00831"></a>00831 <span class="preprocessor">#if UIP_CONF_IPV6</span>
<a name="l00832"></a>00832 <span class="preprocessor"></span>  <span class="comment">/* Check validity of the IP header. */</span>
<a name="l00833"></a>00833   <span class="keywordflow">if</span>((<a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;vtc &amp; 0xf0) != 0x60)  { <span class="comment">/* IP version and header length. */</span>
<a name="l00834"></a>00834     <a class="code" href="a00150.html#g9c0814ed491fa452ec97910c0728d410">UIP_STAT</a>(++<a class="code" href="a00150.html#g9ee50a40597e67fce96541ab56c3b712">uip_stat</a>.<a class="code" href="a00093.html#1deb2899508216804823498a69378118">ip</a>.<a class="code" href="a00093.html#5d8996950cdf3d8130cc3ad340eb9dff">drop</a>);
<a name="l00835"></a>00835     <a class="code" href="a00150.html#g9c0814ed491fa452ec97910c0728d410">UIP_STAT</a>(++<a class="code" href="a00150.html#g9ee50a40597e67fce96541ab56c3b712">uip_stat</a>.<a class="code" href="a00093.html#1deb2899508216804823498a69378118">ip</a>.<a class="code" href="a00093.html#b93e351c3abba0c700b26b7b07e9527d">vhlerr</a>);
<a name="l00836"></a>00836     <a class="code" href="a00150.html#g013c3a06a8b58589a77f4a3442f89c2a">UIP_LOG</a>(<span class="stringliteral">"ipv6: invalid version."</span>);
<a name="l00837"></a>00837     <span class="keywordflow">goto</span> drop;
<a name="l00838"></a>00838   }
<a name="l00839"></a>00839 <span class="preprocessor">#else </span><span class="comment">/* UIP_CONF_IPV6 */</span>
<a name="l00840"></a>00840   <span class="comment">/* Check validity of the IP header. */</span>
<a name="l00841"></a>00841   <span class="keywordflow">if</span>(<a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;vhl != 0x45)  { <span class="comment">/* IP version and header length. */</span>
<a name="l00842"></a>00842     <a class="code" href="a00150.html#g9c0814ed491fa452ec97910c0728d410">UIP_STAT</a>(++<a class="code" href="a00150.html#g9ee50a40597e67fce96541ab56c3b712">uip_stat</a>.<a class="code" href="a00093.html#1deb2899508216804823498a69378118">ip</a>.<a class="code" href="a00093.html#5d8996950cdf3d8130cc3ad340eb9dff">drop</a>);
<a name="l00843"></a>00843     <a class="code" href="a00150.html#g9c0814ed491fa452ec97910c0728d410">UIP_STAT</a>(++<a class="code" href="a00150.html#g9ee50a40597e67fce96541ab56c3b712">uip_stat</a>.<a class="code" href="a00093.html#1deb2899508216804823498a69378118">ip</a>.<a class="code" href="a00093.html#b93e351c3abba0c700b26b7b07e9527d">vhlerr</a>);
<a name="l00844"></a>00844     <a class="code" href="a00150.html#g013c3a06a8b58589a77f4a3442f89c2a">UIP_LOG</a>(<span class="stringliteral">"ip: invalid version or header length."</span>);
<a name="l00845"></a>00845     <span class="keywordflow">goto</span> drop;
<a name="l00846"></a>00846   }
<a name="l00847"></a>00847 <span class="preprocessor">#endif </span><span class="comment">/* UIP_CONF_IPV6 */</span>
<a name="l00848"></a>00848   
<a name="l00849"></a>00849   <span class="comment">/* Check the size of the packet. If the size reported to us in</span>
<a name="l00850"></a>00850 <span class="comment">     uip_len is smaller the size reported in the IP header, we assume</span>
<a name="l00851"></a>00851 <span class="comment">     that the packet has been corrupted in transit. If the size of</span>
<a name="l00852"></a>00852 <span class="comment">     uip_len is larger than the size reported in the IP packet header,</span>
<a name="l00853"></a>00853 <span class="comment">     the packet has been padded and we set uip_len to the correct</span>
<a name="l00854"></a>00854 <span class="comment">     value.. */</span>
<a name="l00855"></a>00855 
<a name="l00856"></a>00856   <span class="keywordflow">if</span>((<a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;len[0] &lt;&lt; 8) + <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;len[1] &lt;= <a class="code" href="a00149.html#g12a33f0c09711167bdf3dd7d7cf8c5a1">uip_len</a>) {
<a name="l00857"></a>00857     <a class="code" href="a00149.html#g12a33f0c09711167bdf3dd7d7cf8c5a1">uip_len</a> = (<a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;len[0] &lt;&lt; 8) + <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;len[1];
<a name="l00858"></a>00858 #<span class="keywordflow">if</span> UIP_CONF_IPV6
<a name="l00859"></a>00859     <a class="code" href="a00149.html#g12a33f0c09711167bdf3dd7d7cf8c5a1">uip_len</a> += 40; <span class="comment">/* The length reported in the IPv6 header is the</span>
<a name="l00860"></a>00860 <span class="comment">                      length of the payload that follows the</span>
<a name="l00861"></a>00861 <span class="comment">                      header. However, uIP uses the uip_len variable</span>
<a name="l00862"></a>00862 <span class="comment">                      for holding the size of the entire packet,</span>
<a name="l00863"></a>00863 <span class="comment">                      including the IP header. For IPv4 this is not a</span>
<a name="l00864"></a>00864 <span class="comment">                      problem as the length field in the IPv4 header</span>
<a name="l00865"></a>00865 <span class="comment">                      contains the length of the entire packet. But</span>
<a name="l00866"></a>00866 <span class="comment">                      for IPv6 we need to add the size of the IPv6</span>
<a name="l00867"></a>00867 <span class="comment">                      header (40 bytes). */</span>
<a name="l00868"></a>00868 #endif <span class="comment">/* UIP_CONF_IPV6 */</span>
<a name="l00869"></a>00869   } <span class="keywordflow">else</span> {
<a name="l00870"></a>00870     <a class="code" href="a00150.html#g013c3a06a8b58589a77f4a3442f89c2a">UIP_LOG</a>(<span class="stringliteral">"ip: packet shorter than reported in IP header."</span>);
<a name="l00871"></a>00871     <span class="keywordflow">goto</span> drop;
<a name="l00872"></a>00872   }
<a name="l00873"></a>00873 
<a name="l00874"></a>00874 <span class="preprocessor">#if !UIP_CONF_IPV6</span>
<a name="l00875"></a>00875 <span class="preprocessor"></span>  <span class="comment">/* Check the fragment flag. */</span>
<a name="l00876"></a>00876   <span class="keywordflow">if</span>((<a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;ipoffset[0] &amp; 0x3f) != 0 ||
<a name="l00877"></a>00877      <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;ipoffset[1] != 0) {
<a name="l00878"></a>00878 <span class="preprocessor">#if UIP_REASSEMBLY</span>
<a name="l00879"></a>00879 <span class="preprocessor"></span>    <a class="code" href="a00149.html#g12a33f0c09711167bdf3dd7d7cf8c5a1">uip_len</a> = uip_reass();
<a name="l00880"></a>00880     <span class="keywordflow">if</span>(<a class="code" href="a00149.html#g12a33f0c09711167bdf3dd7d7cf8c5a1">uip_len</a> == 0) {
<a name="l00881"></a>00881       <span class="keywordflow">goto</span> drop;
<a name="l00882"></a>00882     }
<a name="l00883"></a>00883 <span class="preprocessor">#else </span><span class="comment">/* UIP_REASSEMBLY */</span>
<a name="l00884"></a>00884     <a class="code" href="a00150.html#g9c0814ed491fa452ec97910c0728d410">UIP_STAT</a>(++<a class="code" href="a00150.html#g9ee50a40597e67fce96541ab56c3b712">uip_stat</a>.<a class="code" href="a00093.html#1deb2899508216804823498a69378118">ip</a>.<a class="code" href="a00093.html#5d8996950cdf3d8130cc3ad340eb9dff">drop</a>);
<a name="l00885"></a>00885     <a class="code" href="a00150.html#g9c0814ed491fa452ec97910c0728d410">UIP_STAT</a>(++<a class="code" href="a00150.html#g9ee50a40597e67fce96541ab56c3b712">uip_stat</a>.<a class="code" href="a00093.html#1deb2899508216804823498a69378118">ip</a>.<a class="code" href="a00093.html#8082509468b2ac80ed7746aa1a5bc4f7">fragerr</a>);
<a name="l00886"></a>00886     <a class="code" href="a00150.html#g013c3a06a8b58589a77f4a3442f89c2a">UIP_LOG</a>(<span class="stringliteral">"ip: fragment dropped."</span>);
<a name="l00887"></a>00887     <span class="keywordflow">goto</span> drop;
<a name="l00888"></a>00888 <span class="preprocessor">#endif </span><span class="comment">/* UIP_REASSEMBLY */</span>
<a name="l00889"></a>00889   }
<a name="l00890"></a>00890 <span class="preprocessor">#endif </span><span class="comment">/* UIP_CONF_IPV6 */</span>
<a name="l00891"></a>00891 
<a name="l00892"></a>00892   <span class="keywordflow">if</span>(<a class="code" href="a00148.html#g210e629f7252e4bc8458cbdf260b3318">uip_ipaddr_cmp</a>(<a class="code" href="a00150.html#g7d3673f52f5846b6961d23b150decd54">uip_hostaddr</a>, all_zeroes_addr)) {
<a name="l00893"></a>00893     <span class="comment">/* If we are configured to use ping IP address configuration and</span>
<a name="l00894"></a>00894 <span class="comment">       hasn't been assigned an IP address yet, we accept all ICMP</span>
<a name="l00895"></a>00895 <span class="comment">       packets. */</span>
<a name="l00896"></a>00896 <span class="preprocessor">#if UIP_PINGADDRCONF &amp;&amp; !UIP_CONF_IPV6</span>
<a name="l00897"></a>00897 <span class="preprocessor"></span>    <span class="keywordflow">if</span>(<a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;proto == <a class="code" href="a00150.html#g359951eecd80541c2101f628a9da9146">UIP_PROTO_ICMP</a>) {
<a name="l00898"></a>00898       <a class="code" href="a00150.html#g013c3a06a8b58589a77f4a3442f89c2a">UIP_LOG</a>(<span class="stringliteral">"ip: possible ping config packet received."</span>);
<a name="l00899"></a>00899       <span class="keywordflow">goto</span> icmp_input;
<a name="l00900"></a>00900     } <span class="keywordflow">else</span> {
<a name="l00901"></a>00901       <a class="code" href="a00150.html#g013c3a06a8b58589a77f4a3442f89c2a">UIP_LOG</a>(<span class="stringliteral">"ip: packet dropped since no address assigned."</span>);
<a name="l00902"></a>00902       <span class="keywordflow">goto</span> drop;
<a name="l00903"></a>00903     }
<a name="l00904"></a>00904 <span class="preprocessor">#endif </span><span class="comment">/* UIP_PINGADDRCONF */</span>
<a name="l00905"></a>00905 
<a name="l00906"></a>00906   } <span class="keywordflow">else</span> {
<a name="l00907"></a>00907     <span class="comment">/* If IP broadcast support is configured, we check for a broadcast</span>
<a name="l00908"></a>00908 <span class="comment">       UDP packet, which may be destined to us. */</span>
<a name="l00909"></a>00909 <span class="preprocessor">#if UIP_BROADCAST</span>
<a name="l00910"></a>00910 <span class="preprocessor"></span>    <a class="code" href="a00135.html#534d9e416324fb8ecca6b9cb4b1f6a6a">DEBUG_PRINTF</a>(<span class="stringliteral">"UDP IP checksum 0x%04x\n"</span>, <a class="code" href="a00150.html#g2addf34c7d457c1a7899a7e2171ef1e9">uip_ipchksum</a>());
<a name="l00911"></a>00911     <span class="keywordflow">if</span>(<a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;proto == <a class="code" href="a00150.html#gf72d7b9a737707dcfb2c41fec2b6792e">UIP_PROTO_UDP</a> &amp;&amp;
<a name="l00912"></a>00912        <a class="code" href="a00148.html#g210e629f7252e4bc8458cbdf260b3318">uip_ipaddr_cmp</a>(<a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;destipaddr, all_ones_addr)
<a name="l00913"></a>00913        <span class="comment">/*&amp;&amp;</span>
<a name="l00914"></a>00914 <span class="comment">         uip_ipchksum() == 0xffff*/</span>) {
<a name="l00915"></a>00915       <span class="keywordflow">goto</span> udp_input;
<a name="l00916"></a>00916     }
<a name="l00917"></a>00917 <span class="preprocessor">#endif </span><span class="comment">/* UIP_BROADCAST */</span>
<a name="l00918"></a>00918     
<a name="l00919"></a>00919     <span class="comment">/* Check if the packet is destined for our IP address. */</span>
<a name="l00920"></a>00920 <span class="preprocessor">#if !UIP_CONF_IPV6</span>
<a name="l00921"></a>00921 <span class="preprocessor"></span>    <span class="keywordflow">if</span>(!<a class="code" href="a00148.html#g210e629f7252e4bc8458cbdf260b3318">uip_ipaddr_cmp</a>(<a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;destipaddr, <a class="code" href="a00150.html#g7d3673f52f5846b6961d23b150decd54">uip_hostaddr</a>)) {
<a name="l00922"></a>00922       <a class="code" href="a00150.html#g9c0814ed491fa452ec97910c0728d410">UIP_STAT</a>(++<a class="code" href="a00150.html#g9ee50a40597e67fce96541ab56c3b712">uip_stat</a>.<a class="code" href="a00093.html#1deb2899508216804823498a69378118">ip</a>.<a class="code" href="a00093.html#5d8996950cdf3d8130cc3ad340eb9dff">drop</a>);
<a name="l00923"></a>00923       <span class="keywordflow">goto</span> drop;
<a name="l00924"></a>00924     }
<a name="l00925"></a>00925 <span class="preprocessor">#else </span><span class="comment">/* UIP_CONF_IPV6 */</span>
<a name="l00926"></a>00926     <span class="comment">/* For IPv6, packet reception is a little trickier as we need to</span>
<a name="l00927"></a>00927 <span class="comment">       make sure that we listen to certain multicast addresses (all</span>
<a name="l00928"></a>00928 <span class="comment">       hosts multicast address, and the solicited-node multicast</span>
<a name="l00929"></a>00929 <span class="comment">       address) as well. However, we will cheat here and accept all</span>
<a name="l00930"></a>00930 <span class="comment">       multicast packets that are sent to the ff02::/16 addresses. */</span>
<a name="l00931"></a>00931     <span class="keywordflow">if</span>(!<a class="code" href="a00148.html#g210e629f7252e4bc8458cbdf260b3318">uip_ipaddr_cmp</a>(<a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;destipaddr, <a class="code" href="a00150.html#g7d3673f52f5846b6961d23b150decd54">uip_hostaddr</a>) &amp;&amp;
<a name="l00932"></a>00932        <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;destipaddr[0] != <a class="code" href="a00148.html#g69a7a4951ff21b302267532c21ee78fc">HTONS</a>(0xff02)) {
<a name="l00933"></a>00933       <a class="code" href="a00150.html#g9c0814ed491fa452ec97910c0728d410">UIP_STAT</a>(++<a class="code" href="a00150.html#g9ee50a40597e67fce96541ab56c3b712">uip_stat</a>.<a class="code" href="a00093.html#1deb2899508216804823498a69378118">ip</a>.<a class="code" href="a00093.html#5d8996950cdf3d8130cc3ad340eb9dff">drop</a>);
<a name="l00934"></a>00934       <span class="keywordflow">goto</span> drop;
<a name="l00935"></a>00935     }
<a name="l00936"></a>00936 <span class="preprocessor">#endif </span><span class="comment">/* UIP_CONF_IPV6 */</span>
<a name="l00937"></a>00937   }
<a name="l00938"></a>00938 
<a name="l00939"></a>00939 <span class="preprocessor">#if !UIP_CONF_IPV6</span>
<a name="l00940"></a>00940 <span class="preprocessor"></span>  <span class="keywordflow">if</span>(<a class="code" href="a00150.html#g2addf34c7d457c1a7899a7e2171ef1e9">uip_ipchksum</a>() != 0xffff) { <span class="comment">/* Compute and check the IP header</span>
<a name="l00941"></a>00941 <span class="comment">                                    checksum. */</span>
<a name="l00942"></a>00942     <a class="code" href="a00150.html#g9c0814ed491fa452ec97910c0728d410">UIP_STAT</a>(++<a class="code" href="a00150.html#g9ee50a40597e67fce96541ab56c3b712">uip_stat</a>.<a class="code" href="a00093.html#1deb2899508216804823498a69378118">ip</a>.<a class="code" href="a00093.html#5d8996950cdf3d8130cc3ad340eb9dff">drop</a>);
<a name="l00943"></a>00943     <a class="code" href="a00150.html#g9c0814ed491fa452ec97910c0728d410">UIP_STAT</a>(++<a class="code" href="a00150.html#g9ee50a40597e67fce96541ab56c3b712">uip_stat</a>.<a class="code" href="a00093.html#1deb2899508216804823498a69378118">ip</a>.<a class="code" href="a00093.html#7675e6b9adbddbd545d3aac8ca092fbb">chkerr</a>);
<a name="l00944"></a>00944     <a class="code" href="a00150.html#g013c3a06a8b58589a77f4a3442f89c2a">UIP_LOG</a>(<span class="stringliteral">"ip: bad checksum."</span>);
<a name="l00945"></a>00945     <span class="keywordflow">goto</span> drop;
<a name="l00946"></a>00946   }
<a name="l00947"></a>00947 <span class="preprocessor">#endif </span><span class="comment">/* UIP_CONF_IPV6 */</span>
<a name="l00948"></a>00948 
<a name="l00949"></a>00949   <span class="keywordflow">if</span>(<a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;proto == <a class="code" href="a00150.html#g517c770991459cc62dc009c0d3875c6a">UIP_PROTO_TCP</a>) { <span class="comment">/* Check for TCP packet. If so,</span>
<a name="l00950"></a>00950 <span class="comment">                                       proceed with TCP input</span>
<a name="l00951"></a>00951 <span class="comment">                                       processing. */</span>
<a name="l00952"></a>00952     <span class="keywordflow">goto</span> tcp_input;
<a name="l00953"></a>00953   }
<a name="l00954"></a>00954 
<a name="l00955"></a>00955 <span class="preprocessor">#if UIP_UDP</span>
<a name="l00956"></a>00956 <span class="preprocessor"></span>  <span class="keywordflow">if</span>(<a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;proto == <a class="code" href="a00150.html#gf72d7b9a737707dcfb2c41fec2b6792e">UIP_PROTO_UDP</a>) {
<a name="l00957"></a>00957     <span class="keywordflow">goto</span> udp_input;
<a name="l00958"></a>00958   }
<a name="l00959"></a>00959 <span class="preprocessor">#endif </span><span class="comment">/* UIP_UDP */</span>
<a name="l00960"></a>00960 
<a name="l00961"></a>00961 <span class="preprocessor">#if !UIP_CONF_IPV6</span>
<a name="l00962"></a>00962 <span class="preprocessor"></span>  <span class="comment">/* ICMPv4 processing code follows. */</span>
<a name="l00963"></a>00963   <span class="keywordflow">if</span>(<a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;proto != <a class="code" href="a00150.html#g359951eecd80541c2101f628a9da9146">UIP_PROTO_ICMP</a>) { <span class="comment">/* We only allow ICMP packets from</span>
<a name="l00964"></a>00964 <span class="comment">                                        here. */</span>
<a name="l00965"></a>00965     <a class="code" href="a00150.html#g9c0814ed491fa452ec97910c0728d410">UIP_STAT</a>(++<a class="code" href="a00150.html#g9ee50a40597e67fce96541ab56c3b712">uip_stat</a>.<a class="code" href="a00093.html#1deb2899508216804823498a69378118">ip</a>.<a class="code" href="a00093.html#5d8996950cdf3d8130cc3ad340eb9dff">drop</a>);
<a name="l00966"></a>00966     <a class="code" href="a00150.html#g9c0814ed491fa452ec97910c0728d410">UIP_STAT</a>(++<a class="code" href="a00150.html#g9ee50a40597e67fce96541ab56c3b712">uip_stat</a>.<a class="code" href="a00093.html#1deb2899508216804823498a69378118">ip</a>.<a class="code" href="a00093.html#b4622e2599ff3a592db09219b2641682">protoerr</a>);
<a name="l00967"></a>00967     <a class="code" href="a00150.html#g013c3a06a8b58589a77f4a3442f89c2a">UIP_LOG</a>(<span class="stringliteral">"ip: neither tcp nor icmp."</span>);
<a name="l00968"></a>00968     <span class="keywordflow">goto</span> drop;
<a name="l00969"></a>00969   }
<a name="l00970"></a>00970 
<a name="l00971"></a>00971 <span class="preprocessor">#if UIP_PINGADDRCONF</span>
<a name="l00972"></a>00972 <span class="preprocessor"></span> icmp_input:
<a name="l00973"></a>00973 <span class="preprocessor">#endif </span><span class="comment">/* UIP_PINGADDRCONF */</span>
<a name="l00974"></a>00974   <a class="code" href="a00150.html#g9c0814ed491fa452ec97910c0728d410">UIP_STAT</a>(++<a class="code" href="a00150.html#g9ee50a40597e67fce96541ab56c3b712">uip_stat</a>.<a class="code" href="a00093.html#3983b45977630418d3038231aa8b68ed">icmp</a>.<a class="code" href="a00093.html#7f7bb2145afba5df00c6e10ddefa8ae1">recv</a>);
<a name="l00975"></a>00975 
<a name="l00976"></a>00976   <span class="comment">/* ICMP echo (i.e., ping) processing. This is simple, we only change</span>
<a name="l00977"></a>00977 <span class="comment">     the ICMP type from ECHO to ECHO_REPLY and adjust the ICMP</span>
<a name="l00978"></a>00978 <span class="comment">     checksum before we return the packet. */</span>
<a name="l00979"></a>00979   <span class="keywordflow">if</span>(<a class="code" href="a00150.html#g4309376690872fa4beb4f025f5cc199b">ICMPBUF</a>-&gt;type != <a class="code" href="a00150.html#gd58231410d58e34b455328b888a9e73c">ICMP_ECHO</a>) {
<a name="l00980"></a>00980     <a class="code" href="a00150.html#g9c0814ed491fa452ec97910c0728d410">UIP_STAT</a>(++<a class="code" href="a00150.html#g9ee50a40597e67fce96541ab56c3b712">uip_stat</a>.<a class="code" href="a00093.html#3983b45977630418d3038231aa8b68ed">icmp</a>.<a class="code" href="a00093.html#5d8996950cdf3d8130cc3ad340eb9dff">drop</a>);
<a name="l00981"></a>00981     <a class="code" href="a00150.html#g9c0814ed491fa452ec97910c0728d410">UIP_STAT</a>(++<a class="code" href="a00150.html#g9ee50a40597e67fce96541ab56c3b712">uip_stat</a>.<a class="code" href="a00093.html#3983b45977630418d3038231aa8b68ed">icmp</a>.<a class="code" href="a00093.html#8da121d6e50992ec55778f9b2141552d">typeerr</a>);
<a name="l00982"></a>00982     <a class="code" href="a00150.html#g013c3a06a8b58589a77f4a3442f89c2a">UIP_LOG</a>(<span class="stringliteral">"icmp: not icmp echo."</span>);
<a name="l00983"></a>00983     <span class="keywordflow">goto</span> drop;
<a name="l00984"></a>00984   }
<a name="l00985"></a>00985 
<a name="l00986"></a>00986   <span class="comment">/* If we are configured to use ping IP address assignment, we use</span>
<a name="l00987"></a>00987 <span class="comment">     the destination IP address of this ping packet and assign it to</span>
<a name="l00988"></a>00988 <span class="comment">     ourself. */</span>
<a name="l00989"></a>00989 <span class="preprocessor">#if UIP_PINGADDRCONF</span>
<a name="l00990"></a>00990 <span class="preprocessor"></span>  <span class="keywordflow">if</span>((<a class="code" href="a00150.html#g7d3673f52f5846b6961d23b150decd54">uip_hostaddr</a>[0] | <a class="code" href="a00150.html#g7d3673f52f5846b6961d23b150decd54">uip_hostaddr</a>[1]) == 0) {
<a name="l00991"></a>00991     <a class="code" href="a00150.html#g7d3673f52f5846b6961d23b150decd54">uip_hostaddr</a>[0] = <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;destipaddr[0];
<a name="l00992"></a>00992     <a class="code" href="a00150.html#g7d3673f52f5846b6961d23b150decd54">uip_hostaddr</a>[1] = <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;destipaddr[1];
<a name="l00993"></a>00993   }
<a name="l00994"></a>00994 <span class="preprocessor">#endif </span><span class="comment">/* UIP_PINGADDRCONF */</span>
<a name="l00995"></a>00995 
<a name="l00996"></a>00996   <a class="code" href="a00150.html#g4309376690872fa4beb4f025f5cc199b">ICMPBUF</a>-&gt;type = <a class="code" href="a00150.html#g5c5b1834e497f53ad0ef947bbe9777fa">ICMP_ECHO_REPLY</a>;
<a name="l00997"></a>00997 
<a name="l00998"></a>00998   <span class="keywordflow">if</span>(<a class="code" href="a00150.html#g4309376690872fa4beb4f025f5cc199b">ICMPBUF</a>-&gt;icmpchksum &gt;= <a class="code" href="a00148.html#g69a7a4951ff21b302267532c21ee78fc">HTONS</a>(0xffff - (<a class="code" href="a00150.html#gd58231410d58e34b455328b888a9e73c">ICMP_ECHO</a> &lt;&lt; 8))) {
<a name="l00999"></a>00999     <a class="code" href="a00150.html#g4309376690872fa4beb4f025f5cc199b">ICMPBUF</a>-&gt;icmpchksum += <a class="code" href="a00148.html#g69a7a4951ff21b302267532c21ee78fc">HTONS</a>(<a class="code" href="a00150.html#gd58231410d58e34b455328b888a9e73c">ICMP_ECHO</a> &lt;&lt; 8) + 1;
<a name="l01000"></a>01000   } <span class="keywordflow">else</span> {
<a name="l01001"></a>01001     <a class="code" href="a00150.html#g4309376690872fa4beb4f025f5cc199b">ICMPBUF</a>-&gt;icmpchksum += <a class="code" href="a00148.html#g69a7a4951ff21b302267532c21ee78fc">HTONS</a>(<a class="code" href="a00150.html#gd58231410d58e34b455328b888a9e73c">ICMP_ECHO</a> &lt;&lt; 8);
<a name="l01002"></a>01002   }
<a name="l01003"></a>01003 
<a name="l01004"></a>01004   <span class="comment">/* Swap IP addresses. */</span>
<a name="l01005"></a>01005   <a class="code" href="a00148.html#g769512993b7b27271909d6daa4748b60">uip_ipaddr_copy</a>(<a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;destipaddr, <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;srcipaddr);
<a name="l01006"></a>01006   <a class="code" href="a00148.html#g769512993b7b27271909d6daa4748b60">uip_ipaddr_copy</a>(<a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;srcipaddr, <a class="code" href="a00150.html#g7d3673f52f5846b6961d23b150decd54">uip_hostaddr</a>);
<a name="l01007"></a>01007 
<a name="l01008"></a>01008   <a class="code" href="a00150.html#g9c0814ed491fa452ec97910c0728d410">UIP_STAT</a>(++<a class="code" href="a00150.html#g9ee50a40597e67fce96541ab56c3b712">uip_stat</a>.<a class="code" href="a00093.html#3983b45977630418d3038231aa8b68ed">icmp</a>.<a class="code" href="a00093.html#dc69abadd5aa07c7d74f9292db2cd93c">sent</a>);
<a name="l01009"></a>01009   <span class="keywordflow">goto</span> send;
<a name="l01010"></a>01010 
<a name="l01011"></a>01011   <span class="comment">/* End of IPv4 input header processing code. */</span>
<a name="l01012"></a>01012 <span class="preprocessor">#else </span><span class="comment">/* !UIP_CONF_IPV6 */</span>
<a name="l01013"></a>01013 
<a name="l01014"></a>01014   <span class="comment">/* This is IPv6 ICMPv6 processing code. */</span>
<a name="l01015"></a>01015   <a class="code" href="a00135.html#534d9e416324fb8ecca6b9cb4b1f6a6a">DEBUG_PRINTF</a>(<span class="stringliteral">"icmp6_input: length %d\n"</span>, <a class="code" href="a00149.html#g12a33f0c09711167bdf3dd7d7cf8c5a1">uip_len</a>);
<a name="l01016"></a>01016 
<a name="l01017"></a>01017   <span class="keywordflow">if</span>(<a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;proto != <a class="code" href="a00150.html#gad0321f4c570f9983c6de81ece3ddc20">UIP_PROTO_ICMP6</a>) { <span class="comment">/* We only allow ICMPv6 packets from</span>
<a name="l01018"></a>01018 <span class="comment">                                         here. */</span>
<a name="l01019"></a>01019     <a class="code" href="a00150.html#g9c0814ed491fa452ec97910c0728d410">UIP_STAT</a>(++<a class="code" href="a00150.html#g9ee50a40597e67fce96541ab56c3b712">uip_stat</a>.<a class="code" href="a00093.html#1deb2899508216804823498a69378118">ip</a>.<a class="code" href="a00093.html#5d8996950cdf3d8130cc3ad340eb9dff">drop</a>);
<a name="l01020"></a>01020     <a class="code" href="a00150.html#g9c0814ed491fa452ec97910c0728d410">UIP_STAT</a>(++<a class="code" href="a00150.html#g9ee50a40597e67fce96541ab56c3b712">uip_stat</a>.<a class="code" href="a00093.html#1deb2899508216804823498a69378118">ip</a>.<a class="code" href="a00093.html#b4622e2599ff3a592db09219b2641682">protoerr</a>);
<a name="l01021"></a>01021     <a class="code" href="a00150.html#g013c3a06a8b58589a77f4a3442f89c2a">UIP_LOG</a>(<span class="stringliteral">"ip: neither tcp nor icmp6."</span>);
<a name="l01022"></a>01022     <span class="keywordflow">goto</span> drop;
<a name="l01023"></a>01023   }
<a name="l01024"></a>01024 
<a name="l01025"></a>01025   <a class="code" href="a00150.html#g9c0814ed491fa452ec97910c0728d410">UIP_STAT</a>(++<a class="code" href="a00150.html#g9ee50a40597e67fce96541ab56c3b712">uip_stat</a>.<a class="code" href="a00093.html#3983b45977630418d3038231aa8b68ed">icmp</a>.<a class="code" href="a00093.html#7f7bb2145afba5df00c6e10ddefa8ae1">recv</a>);
<a name="l01026"></a>01026 
<a name="l01027"></a>01027   <span class="comment">/* If we get a neighbor solicitation for our address we should send</span>
<a name="l01028"></a>01028 <span class="comment">     a neighbor advertisement message back. */</span>
<a name="l01029"></a>01029   <span class="keywordflow">if</span>(<a class="code" href="a00150.html#g4309376690872fa4beb4f025f5cc199b">ICMPBUF</a>-&gt;type == <a class="code" href="a00150.html#g1cea57e3ea526f210b1068e6dcf7b4f4">ICMP6_NEIGHBOR_SOLICITATION</a>) {
<a name="l01030"></a>01030     <span class="keywordflow">if</span>(<a class="code" href="a00148.html#g210e629f7252e4bc8458cbdf260b3318">uip_ipaddr_cmp</a>(<a class="code" href="a00150.html#g4309376690872fa4beb4f025f5cc199b">ICMPBUF</a>-&gt;icmp6data, <a class="code" href="a00150.html#g7d3673f52f5846b6961d23b150decd54">uip_hostaddr</a>)) {
<a name="l01031"></a>01031 
<a name="l01032"></a>01032       <span class="keywordflow">if</span>(<a class="code" href="a00150.html#g4309376690872fa4beb4f025f5cc199b">ICMPBUF</a>-&gt;options[0] == <a class="code" href="a00150.html#g42288d5c3cf4b10becefec657f441e54">ICMP6_OPTION_SOURCE_LINK_ADDRESS</a>) {
<a name="l01033"></a>01033         <span class="comment">/* Save the sender's address in our neighbor list. */</span>
<a name="l01034"></a>01034         <a class="code" href="a00132.html#88460bea09a462d0e22511cb567eee14">uip_neighbor_add</a>(<a class="code" href="a00150.html#g4309376690872fa4beb4f025f5cc199b">ICMPBUF</a>-&gt;srcipaddr, &amp;(<a class="code" href="a00150.html#g4309376690872fa4beb4f025f5cc199b">ICMPBUF</a>-&gt;options[2]));
<a name="l01035"></a>01035       }
<a name="l01036"></a>01036       
<a name="l01037"></a>01037       <span class="comment">/* We should now send a neighbor advertisement back to where the</span>
<a name="l01038"></a>01038 <span class="comment">         neighbor solicication came from. */</span>
<a name="l01039"></a>01039       <a class="code" href="a00150.html#g4309376690872fa4beb4f025f5cc199b">ICMPBUF</a>-&gt;type = <a class="code" href="a00150.html#g62c03e0a308cc23929a80fe8d8f9dc1e">ICMP6_NEIGHBOR_ADVERTISEMENT</a>;
<a name="l01040"></a>01040       <a class="code" href="a00150.html#g4309376690872fa4beb4f025f5cc199b">ICMPBUF</a>-&gt;flags = <a class="code" href="a00150.html#g1d3211dbbdfb22d6a47b60dddcf945e8">ICMP6_FLAG_S</a>; <span class="comment">/* Solicited flag. */</span>
<a name="l01041"></a>01041       
<a name="l01042"></a>01042       <a class="code" href="a00150.html#g4309376690872fa4beb4f025f5cc199b">ICMPBUF</a>-&gt;reserved1 = <a class="code" href="a00150.html#g4309376690872fa4beb4f025f5cc199b">ICMPBUF</a>-&gt;reserved2 = <a class="code" href="a00150.html#g4309376690872fa4beb4f025f5cc199b">ICMPBUF</a>-&gt;reserved3 = 0;
<a name="l01043"></a>01043       
<a name="l01044"></a>01044       <a class="code" href="a00148.html#g769512993b7b27271909d6daa4748b60">uip_ipaddr_copy</a>(<a class="code" href="a00150.html#g4309376690872fa4beb4f025f5cc199b">ICMPBUF</a>-&gt;destipaddr, <a class="code" href="a00150.html#g4309376690872fa4beb4f025f5cc199b">ICMPBUF</a>-&gt;srcipaddr);
<a name="l01045"></a>01045       <a class="code" href="a00148.html#g769512993b7b27271909d6daa4748b60">uip_ipaddr_copy</a>(<a class="code" href="a00150.html#g4309376690872fa4beb4f025f5cc199b">ICMPBUF</a>-&gt;srcipaddr, <a class="code" href="a00150.html#g7d3673f52f5846b6961d23b150decd54">uip_hostaddr</a>);
<a name="l01046"></a>01046       <a class="code" href="a00150.html#g4309376690872fa4beb4f025f5cc199b">ICMPBUF</a>-&gt;options[0] = <a class="code" href="a00150.html#g8387881de3a8bfd3c0d57b9d04ac9b7e">ICMP6_OPTION_TARGET_LINK_ADDRESS</a>;
<a name="l01047"></a>01047       <a class="code" href="a00150.html#g4309376690872fa4beb4f025f5cc199b">ICMPBUF</a>-&gt;options[1] = 1;  <span class="comment">/* Options length, 1 = 8 bytes. */</span>
<a name="l01048"></a>01048       memcpy(&amp;(<a class="code" href="a00150.html#g4309376690872fa4beb4f025f5cc199b">ICMPBUF</a>-&gt;options[2]), &amp;<a class="code" href="a00150.html#g499bb98a0b4ae9a98553ede81317606d">uip_ethaddr</a>, <span class="keyword">sizeof</span>(<a class="code" href="a00150.html#g499bb98a0b4ae9a98553ede81317606d">uip_ethaddr</a>));
<a name="l01049"></a>01049       <a class="code" href="a00150.html#g4309376690872fa4beb4f025f5cc199b">ICMPBUF</a>-&gt;icmpchksum = 0;
<a name="l01050"></a>01050       <a class="code" href="a00150.html#g4309376690872fa4beb4f025f5cc199b">ICMPBUF</a>-&gt;icmpchksum = ~uip_icmp6chksum();
<a name="l01051"></a>01051       <span class="keywordflow">goto</span> send;
<a name="l01052"></a>01052       
<a name="l01053"></a>01053     }
<a name="l01054"></a>01054     <span class="keywordflow">goto</span> drop;
<a name="l01055"></a>01055   } <span class="keywordflow">else</span> <span class="keywordflow">if</span>(<a class="code" href="a00150.html#g4309376690872fa4beb4f025f5cc199b">ICMPBUF</a>-&gt;type == <a class="code" href="a00150.html#g4cc3e223b63f27b546d62e9a258dba5a">ICMP6_ECHO</a>) {
<a name="l01056"></a>01056     <span class="comment">/* ICMP echo (i.e., ping) processing. This is simple, we only</span>
<a name="l01057"></a>01057 <span class="comment">       change the ICMP type from ECHO to ECHO_REPLY and update the</span>
<a name="l01058"></a>01058 <span class="comment">       ICMP checksum before we return the packet. */</span>
<a name="l01059"></a>01059 
<a name="l01060"></a>01060     <a class="code" href="a00150.html#g4309376690872fa4beb4f025f5cc199b">ICMPBUF</a>-&gt;type = <a class="code" href="a00150.html#g207d17b633cd095120a74bc1f2257b17">ICMP6_ECHO_REPLY</a>;
<a name="l01061"></a>01061     
<a name="l01062"></a>01062     <a class="code" href="a00148.html#g769512993b7b27271909d6daa4748b60">uip_ipaddr_copy</a>(<a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;destipaddr, <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;srcipaddr);
<a name="l01063"></a>01063     <a class="code" href="a00148.html#g769512993b7b27271909d6daa4748b60">uip_ipaddr_copy</a>(<a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;srcipaddr, <a class="code" href="a00150.html#g7d3673f52f5846b6961d23b150decd54">uip_hostaddr</a>);
<a name="l01064"></a>01064     <a class="code" href="a00150.html#g4309376690872fa4beb4f025f5cc199b">ICMPBUF</a>-&gt;icmpchksum = 0;
<a name="l01065"></a>01065     <a class="code" href="a00150.html#g4309376690872fa4beb4f025f5cc199b">ICMPBUF</a>-&gt;icmpchksum = ~uip_icmp6chksum();
<a name="l01066"></a>01066     
<a name="l01067"></a>01067     <a class="code" href="a00150.html#g9c0814ed491fa452ec97910c0728d410">UIP_STAT</a>(++<a class="code" href="a00150.html#g9ee50a40597e67fce96541ab56c3b712">uip_stat</a>.<a class="code" href="a00093.html#3983b45977630418d3038231aa8b68ed">icmp</a>.<a class="code" href="a00093.html#dc69abadd5aa07c7d74f9292db2cd93c">sent</a>);
<a name="l01068"></a>01068     <span class="keywordflow">goto</span> send;
<a name="l01069"></a>01069   } <span class="keywordflow">else</span> {
<a name="l01070"></a>01070     <a class="code" href="a00135.html#534d9e416324fb8ecca6b9cb4b1f6a6a">DEBUG_PRINTF</a>(<span class="stringliteral">"Unknown icmp6 message type %d\n"</span>, <a class="code" href="a00150.html#g4309376690872fa4beb4f025f5cc199b">ICMPBUF</a>-&gt;type);
<a name="l01071"></a>01071     <a class="code" href="a00150.html#g9c0814ed491fa452ec97910c0728d410">UIP_STAT</a>(++<a class="code" href="a00150.html#g9ee50a40597e67fce96541ab56c3b712">uip_stat</a>.<a class="code" href="a00093.html#3983b45977630418d3038231aa8b68ed">icmp</a>.<a class="code" href="a00093.html#5d8996950cdf3d8130cc3ad340eb9dff">drop</a>);
<a name="l01072"></a>01072     <a class="code" href="a00150.html#g9c0814ed491fa452ec97910c0728d410">UIP_STAT</a>(++<a class="code" href="a00150.html#g9ee50a40597e67fce96541ab56c3b712">uip_stat</a>.<a class="code" href="a00093.html#3983b45977630418d3038231aa8b68ed">icmp</a>.<a class="code" href="a00093.html#8da121d6e50992ec55778f9b2141552d">typeerr</a>);
<a name="l01073"></a>01073     <a class="code" href="a00150.html#g013c3a06a8b58589a77f4a3442f89c2a">UIP_LOG</a>(<span class="stringliteral">"icmp: unknown ICMP message."</span>);
<a name="l01074"></a>01074     <span class="keywordflow">goto</span> drop;
<a name="l01075"></a>01075   }
<a name="l01076"></a>01076 
<a name="l01077"></a>01077   <span class="comment">/* End of IPv6 ICMP processing. */</span>
<a name="l01078"></a>01078   
<a name="l01079"></a>01079 <span class="preprocessor">#endif </span><span class="comment">/* !UIP_CONF_IPV6 */</span>
<a name="l01080"></a>01080 
<a name="l01081"></a>01081 <span class="preprocessor">#if UIP_UDP</span>
<a name="l01082"></a>01082 <span class="preprocessor"></span>  <span class="comment">/* UDP input processing. */</span>
<a name="l01083"></a>01083  udp_input:
<a name="l01084"></a>01084   <span class="comment">/* UDP processing is really just a hack. We don't do anything to the</span>
<a name="l01085"></a>01085 <span class="comment">     UDP/IP headers, but let the UDP application do all the hard</span>
<a name="l01086"></a>01086 <span class="comment">     work. If the application sets uip_slen, it has a packet to</span>
<a name="l01087"></a>01087 <span class="comment">     send. */</span>
<a name="l01088"></a>01088 <span class="preprocessor">#if UIP_UDP_CHECKSUMS</span>
<a name="l01089"></a>01089 <span class="preprocessor"></span>  <a class="code" href="a00149.html#g12a33f0c09711167bdf3dd7d7cf8c5a1">uip_len</a> = <a class="code" href="a00149.html#g12a33f0c09711167bdf3dd7d7cf8c5a1">uip_len</a> - <a class="code" href="a00150.html#g6f2b90c597ec23f39ec716ccec11233c">UIP_IPUDPH_LEN</a>;
<a name="l01090"></a>01090   <a class="code" href="a00150.html#g561b8eda32e059d4e7397f776268cc63">uip_appdata</a> = &amp;<a class="code" href="a00146.html#gb81e78f890dbbee50c533a9734b74fd9">uip_buf</a>[<a class="code" href="a00153.html#ge6f4a2453dbd8bc60e6a82774552366a">UIP_LLH_LEN</a> + UIP_IPUDPH_LEN];
<a name="l01091"></a>01091   <span class="keywordflow">if</span>(<a class="code" href="a00150.html#gb9435261753469accec0c9bf8a5a2686">UDPBUF</a>-&gt;udpchksum != 0 &amp;&amp; <a class="code" href="a00150.html#g7023a34ba9e9d03b5fbedbcb32924453">uip_udpchksum</a>() != 0xffff) {
<a name="l01092"></a>01092     <a class="code" href="a00150.html#g9c0814ed491fa452ec97910c0728d410">UIP_STAT</a>(++<a class="code" href="a00150.html#g9ee50a40597e67fce96541ab56c3b712">uip_stat</a>.<a class="code" href="a00093.html#4f39f0fe6a820d260fe6cddf9ccaa832">udp</a>.<a class="code" href="a00093.html#5d8996950cdf3d8130cc3ad340eb9dff">drop</a>);
<a name="l01093"></a>01093     <a class="code" href="a00150.html#g9c0814ed491fa452ec97910c0728d410">UIP_STAT</a>(++<a class="code" href="a00150.html#g9ee50a40597e67fce96541ab56c3b712">uip_stat</a>.<a class="code" href="a00093.html#4f39f0fe6a820d260fe6cddf9ccaa832">udp</a>.<a class="code" href="a00093.html#7675e6b9adbddbd545d3aac8ca092fbb">chkerr</a>);
<a name="l01094"></a>01094     <a class="code" href="a00150.html#g013c3a06a8b58589a77f4a3442f89c2a">UIP_LOG</a>(<span class="stringliteral">"udp: bad checksum."</span>);
<a name="l01095"></a>01095     <span class="keywordflow">goto</span> drop;
<a name="l01096"></a>01096   }
<a name="l01097"></a>01097 <span class="preprocessor">#else </span><span class="comment">/* UIP_UDP_CHECKSUMS */</span>
<a name="l01098"></a>01098   <a class="code" href="a00149.html#g12a33f0c09711167bdf3dd7d7cf8c5a1">uip_len</a> = <a class="code" href="a00149.html#g12a33f0c09711167bdf3dd7d7cf8c5a1">uip_len</a> - UIP_IPUDPH_LEN;
<a name="l01099"></a>01099 <span class="preprocessor">#endif </span><span class="comment">/* UIP_UDP_CHECKSUMS */</span>
<a name="l01100"></a>01100 
<a name="l01101"></a>01101   <span class="comment">/* Demultiplex this UDP packet between the UDP "connections". */</span>
<a name="l01102"></a>01102   <span class="keywordflow">for</span>(<a class="code" href="a00095.html">uip_udp_conn</a> = &amp;<a class="code" href="a00150.html#geb533744817cf6695d75293369c2248b">uip_udp_conns</a>[0];
<a name="l01103"></a>01103       <a class="code" href="a00095.html">uip_udp_conn</a> &lt; &amp;<a class="code" href="a00150.html#geb533744817cf6695d75293369c2248b">uip_udp_conns</a>[<a class="code" href="a00153.html#g196379ceb1219a99f4495e41ccc9bbfb">UIP_UDP_CONNS</a>];
<a name="l01104"></a>01104       ++<a class="code" href="a00095.html">uip_udp_conn</a>) {
<a name="l01105"></a>01105     <span class="comment">/* If the local UDP port is non-zero, the connection is considered</span>
<a name="l01106"></a>01106 <span class="comment">       to be used. If so, the local port number is checked against the</span>
<a name="l01107"></a>01107 <span class="comment">       destination port number in the received packet. If the two port</span>
<a name="l01108"></a>01108 <span class="comment">       numbers match, the remote port number is checked if the</span>
<a name="l01109"></a>01109 <span class="comment">       connection is bound to a remote port. Finally, if the</span>
<a name="l01110"></a>01110 <span class="comment">       connection is bound to a remote IP address, the source IP</span>
<a name="l01111"></a>01111 <span class="comment">       address of the packet is checked. */</span>
<a name="l01112"></a>01112     <span class="keywordflow">if</span>(<a class="code" href="a00095.html">uip_udp_conn</a>-&gt;lport != 0 &amp;&amp;
<a name="l01113"></a>01113        <a class="code" href="a00150.html#gb9435261753469accec0c9bf8a5a2686">UDPBUF</a>-&gt;destport == <a class="code" href="a00095.html">uip_udp_conn</a>-&gt;lport &amp;&amp;
<a name="l01114"></a>01114        (<a class="code" href="a00095.html">uip_udp_conn</a>-&gt;rport == 0 ||
<a name="l01115"></a>01115         <a class="code" href="a00150.html#gb9435261753469accec0c9bf8a5a2686">UDPBUF</a>-&gt;srcport == <a class="code" href="a00095.html">uip_udp_conn</a>-&gt;rport) &amp;&amp;
<a name="l01116"></a>01116        (<a class="code" href="a00148.html#g210e629f7252e4bc8458cbdf260b3318">uip_ipaddr_cmp</a>(<a class="code" href="a00095.html">uip_udp_conn</a>-&gt;ripaddr, all_zeroes_addr) ||
<a name="l01117"></a>01117         <a class="code" href="a00148.html#g210e629f7252e4bc8458cbdf260b3318">uip_ipaddr_cmp</a>(<a class="code" href="a00095.html">uip_udp_conn</a>-&gt;ripaddr, all_ones_addr) ||
<a name="l01118"></a>01118         <a class="code" href="a00148.html#g210e629f7252e4bc8458cbdf260b3318">uip_ipaddr_cmp</a>(<a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;srcipaddr, <a class="code" href="a00095.html">uip_udp_conn</a>-&gt;ripaddr))) {
<a name="l01119"></a>01119       <span class="keywordflow">goto</span> udp_found;
<a name="l01120"></a>01120     }
<a name="l01121"></a>01121   }
<a name="l01122"></a>01122   <a class="code" href="a00150.html#g013c3a06a8b58589a77f4a3442f89c2a">UIP_LOG</a>(<span class="stringliteral">"udp: no matching connection found"</span>);
<a name="l01123"></a>01123   <span class="keywordflow">goto</span> drop;
<a name="l01124"></a>01124   
<a name="l01125"></a>01125  udp_found:
<a name="l01126"></a>01126   <a class="code" href="a00088.html">uip_conn</a> = <a class="code" href="a00160.html#g070d2ce7b6bb7e5c05602aa8c308d0c4">NULL</a>;
<a name="l01127"></a>01127   <a class="code" href="a00150.html#gb4ef6b00924990e7a293f66715b6d1d1">uip_flags</a> = <a class="code" href="a00150.html#g39ce739bd352d7e348e37395ce903e43">UIP_NEWDATA</a>;
<a name="l01128"></a>01128   <a class="code" href="a00150.html#ga05a3dde2048480fa3ab2a5961898d18">uip_sappdata</a> = <a class="code" href="a00150.html#g561b8eda32e059d4e7397f776268cc63">uip_appdata</a> = &amp;<a class="code" href="a00146.html#gb81e78f890dbbee50c533a9734b74fd9">uip_buf</a>[<a class="code" href="a00153.html#ge6f4a2453dbd8bc60e6a82774552366a">UIP_LLH_LEN</a> + <a class="code" href="a00150.html#g6f2b90c597ec23f39ec716ccec11233c">UIP_IPUDPH_LEN</a>];
<a name="l01129"></a>01129   <a class="code" href="a00150.html#g5b5615dc240daed20949c0fded2b4679">uip_slen</a> = 0;
<a name="l01130"></a>01130   <a class="code" href="a00160.html#g3d768e989e308144190ae1a5ddfa9726">UIP_UDP_APPCALL</a>();
<a name="l01131"></a>01131  udp_send:
<a name="l01132"></a>01132   <span class="keywordflow">if</span>(<a class="code" href="a00150.html#g5b5615dc240daed20949c0fded2b4679">uip_slen</a> == 0) {
<a name="l01133"></a>01133     <span class="keywordflow">goto</span> drop;
<a name="l01134"></a>01134   }
<a name="l01135"></a>01135   <a class="code" href="a00149.html#g12a33f0c09711167bdf3dd7d7cf8c5a1">uip_len</a> = <a class="code" href="a00150.html#g5b5615dc240daed20949c0fded2b4679">uip_slen</a> + <a class="code" href="a00150.html#g6f2b90c597ec23f39ec716ccec11233c">UIP_IPUDPH_LEN</a>;
<a name="l01136"></a>01136 
<a name="l01137"></a>01137 <span class="preprocessor">#if UIP_CONF_IPV6</span>
<a name="l01138"></a>01138 <span class="preprocessor"></span>  <span class="comment">/* For IPv6, the IP length field does not include the IPv6 IP header</span>
<a name="l01139"></a>01139 <span class="comment">     length. */</span>
<a name="l01140"></a>01140   <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;len[0] = ((<a class="code" href="a00149.html#g12a33f0c09711167bdf3dd7d7cf8c5a1">uip_len</a> - <a class="code" href="a00150.html#g6bc12c6c7b56f73ce5d57abfdcdc6eb5">UIP_IPH_LEN</a>) &gt;&gt; 8);
<a name="l01141"></a>01141   <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;len[1] = ((<a class="code" href="a00149.html#g12a33f0c09711167bdf3dd7d7cf8c5a1">uip_len</a> - <a class="code" href="a00150.html#g6bc12c6c7b56f73ce5d57abfdcdc6eb5">UIP_IPH_LEN</a>) &amp; 0xff);
<a name="l01142"></a>01142 <span class="preprocessor">#else </span><span class="comment">/* UIP_CONF_IPV6 */</span>
<a name="l01143"></a>01143   <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;len[0] = (<a class="code" href="a00149.html#g12a33f0c09711167bdf3dd7d7cf8c5a1">uip_len</a> &gt;&gt; 8);
<a name="l01144"></a>01144   <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;len[1] = (<a class="code" href="a00149.html#g12a33f0c09711167bdf3dd7d7cf8c5a1">uip_len</a> &amp; 0xff);
<a name="l01145"></a>01145 <span class="preprocessor">#endif </span><span class="comment">/* UIP_CONF_IPV6 */</span>
<a name="l01146"></a>01146 
<a name="l01147"></a>01147   <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;ttl = <a class="code" href="a00095.html">uip_udp_conn</a>-&gt;ttl;
<a name="l01148"></a>01148   <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;proto = <a class="code" href="a00150.html#gf72d7b9a737707dcfb2c41fec2b6792e">UIP_PROTO_UDP</a>;
<a name="l01149"></a>01149 
<a name="l01150"></a>01150   <a class="code" href="a00150.html#gb9435261753469accec0c9bf8a5a2686">UDPBUF</a>-&gt;udplen = <a class="code" href="a00148.html#g69a7a4951ff21b302267532c21ee78fc">HTONS</a>(<a class="code" href="a00150.html#g5b5615dc240daed20949c0fded2b4679">uip_slen</a> + <a class="code" href="a00150.html#gb948296aea6b6b3aa1f156799c4d479c">UIP_UDPH_LEN</a>);
<a name="l01151"></a>01151   <a class="code" href="a00150.html#gb9435261753469accec0c9bf8a5a2686">UDPBUF</a>-&gt;udpchksum = 0;
<a name="l01152"></a>01152 
<a name="l01153"></a>01153   <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;srcport  = <a class="code" href="a00095.html">uip_udp_conn</a>-&gt;lport;
<a name="l01154"></a>01154   <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;destport = <a class="code" href="a00095.html">uip_udp_conn</a>-&gt;rport;
<a name="l01155"></a>01155 
<a name="l01156"></a>01156   <a class="code" href="a00148.html#g769512993b7b27271909d6daa4748b60">uip_ipaddr_copy</a>(<a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;srcipaddr, <a class="code" href="a00150.html#g7d3673f52f5846b6961d23b150decd54">uip_hostaddr</a>);
<a name="l01157"></a>01157   <a class="code" href="a00148.html#g769512993b7b27271909d6daa4748b60">uip_ipaddr_copy</a>(<a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;destipaddr, <a class="code" href="a00095.html">uip_udp_conn</a>-&gt;ripaddr);
<a name="l01158"></a>01158    
<a name="l01159"></a>01159   <a class="code" href="a00150.html#g561b8eda32e059d4e7397f776268cc63">uip_appdata</a> = &amp;<a class="code" href="a00146.html#gb81e78f890dbbee50c533a9734b74fd9">uip_buf</a>[<a class="code" href="a00153.html#ge6f4a2453dbd8bc60e6a82774552366a">UIP_LLH_LEN</a> + <a class="code" href="a00150.html#g15f2617f7dc1713f9d10282125c6027b">UIP_IPTCPH_LEN</a>];
<a name="l01160"></a>01160 
<a name="l01161"></a>01161 <span class="preprocessor">#if UIP_UDP_CHECKSUMS</span>
<a name="l01162"></a>01162 <span class="preprocessor"></span>  <span class="comment">/* Calculate UDP checksum. */</span>
<a name="l01163"></a>01163   <a class="code" href="a00150.html#gb9435261753469accec0c9bf8a5a2686">UDPBUF</a>-&gt;udpchksum = ~(<a class="code" href="a00150.html#g7023a34ba9e9d03b5fbedbcb32924453">uip_udpchksum</a>());
<a name="l01164"></a>01164   <span class="keywordflow">if</span>(<a class="code" href="a00150.html#gb9435261753469accec0c9bf8a5a2686">UDPBUF</a>-&gt;udpchksum == 0) {
<a name="l01165"></a>01165     <a class="code" href="a00150.html#gb9435261753469accec0c9bf8a5a2686">UDPBUF</a>-&gt;udpchksum = 0xffff;
<a name="l01166"></a>01166   }
<a name="l01167"></a>01167 <span class="preprocessor">#endif </span><span class="comment">/* UIP_UDP_CHECKSUMS */</span>
<a name="l01168"></a>01168   
<a name="l01169"></a>01169   <span class="keywordflow">goto</span> ip_send_nolen;
<a name="l01170"></a>01170 <span class="preprocessor">#endif </span><span class="comment">/* UIP_UDP */</span>
<a name="l01171"></a>01171   
<a name="l01172"></a>01172   <span class="comment">/* TCP input processing. */</span>
<a name="l01173"></a>01173  tcp_input:
<a name="l01174"></a>01174   <a class="code" href="a00150.html#g9c0814ed491fa452ec97910c0728d410">UIP_STAT</a>(++<a class="code" href="a00150.html#g9ee50a40597e67fce96541ab56c3b712">uip_stat</a>.<a class="code" href="a00093.html#e292b8977f6b81265bf14e1676face3e">tcp</a>.<a class="code" href="a00093.html#7f7bb2145afba5df00c6e10ddefa8ae1">recv</a>);
<a name="l01175"></a>01175 
<a name="l01176"></a>01176   <span class="comment">/* Start of TCP input header processing code. */</span>
<a name="l01177"></a>01177   
<a name="l01178"></a>01178   <span class="keywordflow">if</span>(<a class="code" href="a00150.html#g85b65e38aa74eba18979156f97a94a87">uip_tcpchksum</a>() != 0xffff) {   <span class="comment">/* Compute and check the TCP</span>
<a name="l01179"></a>01179 <span class="comment">                                       checksum. */</span>
<a name="l01180"></a>01180     <a class="code" href="a00150.html#g9c0814ed491fa452ec97910c0728d410">UIP_STAT</a>(++<a class="code" href="a00150.html#g9ee50a40597e67fce96541ab56c3b712">uip_stat</a>.<a class="code" href="a00093.html#e292b8977f6b81265bf14e1676face3e">tcp</a>.<a class="code" href="a00093.html#5d8996950cdf3d8130cc3ad340eb9dff">drop</a>);
<a name="l01181"></a>01181     <a class="code" href="a00150.html#g9c0814ed491fa452ec97910c0728d410">UIP_STAT</a>(++<a class="code" href="a00150.html#g9ee50a40597e67fce96541ab56c3b712">uip_stat</a>.<a class="code" href="a00093.html#e292b8977f6b81265bf14e1676face3e">tcp</a>.<a class="code" href="a00093.html#7675e6b9adbddbd545d3aac8ca092fbb">chkerr</a>);
<a name="l01182"></a>01182     <a class="code" href="a00150.html#g013c3a06a8b58589a77f4a3442f89c2a">UIP_LOG</a>(<span class="stringliteral">"tcp: bad checksum."</span>);
<a name="l01183"></a>01183     <span class="keywordflow">goto</span> drop;
<a name="l01184"></a>01184   }
<a name="l01185"></a>01185   
<a name="l01186"></a>01186   
<a name="l01187"></a>01187   <span class="comment">/* Demultiplex this segment. */</span>
<a name="l01188"></a>01188   <span class="comment">/* First check any active connections. */</span>
<a name="l01189"></a>01189   <span class="keywordflow">for</span>(uip_connr = &amp;<a class="code" href="a00150.html#gf703683056d2bfa5c81fa157dcb20fe2">uip_conns</a>[0]; uip_connr &lt;= &amp;<a class="code" href="a00150.html#gf703683056d2bfa5c81fa157dcb20fe2">uip_conns</a>[<a class="code" href="a00153.html#gf5fe83be78b78b9e7d9e7f1e34ab1cc5">UIP_CONNS</a> - 1];
<a name="l01190"></a>01190       ++uip_connr) {
<a name="l01191"></a>01191     <span class="keywordflow">if</span>(uip_connr-&gt;tcpstateflags != <a class="code" href="a00150.html#g28eda870cff3d8e3cf2949e6f57a502b">UIP_CLOSED</a> &amp;&amp;
<a name="l01192"></a>01192        <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;destport == uip_connr-&gt;lport &amp;&amp;
<a name="l01193"></a>01193        <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;srcport == uip_connr-&gt;rport &amp;&amp;
<a name="l01194"></a>01194        <a class="code" href="a00148.html#g210e629f7252e4bc8458cbdf260b3318">uip_ipaddr_cmp</a>(<a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;srcipaddr, uip_connr-&gt;ripaddr)) {
<a name="l01195"></a>01195       <span class="keywordflow">goto</span> found;
<a name="l01196"></a>01196     }
<a name="l01197"></a>01197   }
<a name="l01198"></a>01198 
<a name="l01199"></a>01199   <span class="comment">/* If we didn't find and active connection that expected the packet,</span>
<a name="l01200"></a>01200 <span class="comment">     either this packet is an old duplicate, or this is a SYN packet</span>
<a name="l01201"></a>01201 <span class="comment">     destined for a connection in LISTEN. If the SYN flag isn't set,</span>
<a name="l01202"></a>01202 <span class="comment">     it is an old packet and we send a RST. */</span>
<a name="l01203"></a>01203   <span class="keywordflow">if</span>((<a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;flags &amp; <a class="code" href="a00150.html#g1425d4a0c2760adb653a04c0fb137a8d">TCP_CTL</a>) != <a class="code" href="a00150.html#g6020613f5062417d9811cfa837215c83">TCP_SYN</a>) {
<a name="l01204"></a>01204     <span class="keywordflow">goto</span> reset;
<a name="l01205"></a>01205   }
<a name="l01206"></a>01206   
<a name="l01207"></a>01207   tmp16 = <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;destport;
<a name="l01208"></a>01208   <span class="comment">/* Next, check listening connections. */</span>
<a name="l01209"></a>01209   <span class="keywordflow">for</span>(c = 0; c &lt; <a class="code" href="a00153.html#g8f4ebd8ef6c0ea665ed351d87fec09fd">UIP_LISTENPORTS</a>; ++c) {
<a name="l01210"></a>01210     <span class="keywordflow">if</span>(tmp16 == <a class="code" href="a00150.html#g236d5c7872f59c8fe7b701c7252b976e">uip_listenports</a>[c])
<a name="l01211"></a>01211       <span class="keywordflow">goto</span> found_listen;
<a name="l01212"></a>01212   }
<a name="l01213"></a>01213   
<a name="l01214"></a>01214   <span class="comment">/* No matching connection found, so we send a RST packet. */</span>
<a name="l01215"></a>01215   <a class="code" href="a00150.html#g9c0814ed491fa452ec97910c0728d410">UIP_STAT</a>(++<a class="code" href="a00150.html#g9ee50a40597e67fce96541ab56c3b712">uip_stat</a>.<a class="code" href="a00093.html#e292b8977f6b81265bf14e1676face3e">tcp</a>.<a class="code" href="a00093.html#e9205a565ea3c911a785fc4e87c91a58">synrst</a>);
<a name="l01216"></a>01216  reset:
<a name="l01217"></a>01217 
<a name="l01218"></a>01218   <span class="comment">/* We do not send resets in response to resets. */</span>
<a name="l01219"></a>01219   <span class="keywordflow">if</span>(<a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;flags &amp; <a class="code" href="a00150.html#g5ca559def464ef20d8b1f7d32f2f160d">TCP_RST</a>) {
<a name="l01220"></a>01220     <span class="keywordflow">goto</span> drop;
<a name="l01221"></a>01221   }
<a name="l01222"></a>01222 
<a name="l01223"></a>01223   <a class="code" href="a00150.html#g9c0814ed491fa452ec97910c0728d410">UIP_STAT</a>(++<a class="code" href="a00150.html#g9ee50a40597e67fce96541ab56c3b712">uip_stat</a>.<a class="code" href="a00093.html#e292b8977f6b81265bf14e1676face3e">tcp</a>.<a class="code" href="a00093.html#b6e9a75167bdddd561373bc5b6ef501c">rst</a>);
<a name="l01224"></a>01224   
<a name="l01225"></a>01225   <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;flags = <a class="code" href="a00150.html#g5ca559def464ef20d8b1f7d32f2f160d">TCP_RST</a> | <a class="code" href="a00150.html#g44b3b1ab31a403ba28ec135adfcbefef">TCP_ACK</a>;
<a name="l01226"></a>01226   <a class="code" href="a00149.html#g12a33f0c09711167bdf3dd7d7cf8c5a1">uip_len</a> = <a class="code" href="a00150.html#g15f2617f7dc1713f9d10282125c6027b">UIP_IPTCPH_LEN</a>;
<a name="l01227"></a>01227   <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;tcpoffset = 5 &lt;&lt; 4;
<a name="l01228"></a>01228 
<a name="l01229"></a>01229   <span class="comment">/* Flip the seqno and ackno fields in the TCP header. */</span>
<a name="l01230"></a>01230   c = <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;seqno[3];
<a name="l01231"></a>01231   <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;seqno[3] = <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;ackno[3];
<a name="l01232"></a>01232   <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;ackno[3] = c;
<a name="l01233"></a>01233   
<a name="l01234"></a>01234   c = <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;seqno[2];
<a name="l01235"></a>01235   <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;seqno[2] = <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;ackno[2];
<a name="l01236"></a>01236   <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;ackno[2] = c;
<a name="l01237"></a>01237   
<a name="l01238"></a>01238   c = <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;seqno[1];
<a name="l01239"></a>01239   <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;seqno[1] = <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;ackno[1];
<a name="l01240"></a>01240   <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;ackno[1] = c;
<a name="l01241"></a>01241   
<a name="l01242"></a>01242   c = <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;seqno[0];
<a name="l01243"></a>01243   <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;seqno[0] = <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;ackno[0];
<a name="l01244"></a>01244   <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;ackno[0] = c;
<a name="l01245"></a>01245 
<a name="l01246"></a>01246   <span class="comment">/* We also have to increase the sequence number we are</span>
<a name="l01247"></a>01247 <span class="comment">     acknowledging. If the least significant byte overflowed, we need</span>
<a name="l01248"></a>01248 <span class="comment">     to propagate the carry to the other bytes as well. */</span>
<a name="l01249"></a>01249   <span class="keywordflow">if</span>(++<a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;ackno[3] == 0) {
<a name="l01250"></a>01250     <span class="keywordflow">if</span>(++<a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;ackno[2] == 0) {
<a name="l01251"></a>01251       <span class="keywordflow">if</span>(++<a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;ackno[1] == 0) {
<a name="l01252"></a>01252         ++<a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;ackno[0];
<a name="l01253"></a>01253       }
<a name="l01254"></a>01254     }
<a name="l01255"></a>01255   }
<a name="l01256"></a>01256  
<a name="l01257"></a>01257   <span class="comment">/* Swap port numbers. */</span>
<a name="l01258"></a>01258   tmp16 = <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;srcport;
<a name="l01259"></a>01259   <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;srcport = <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;destport;
<a name="l01260"></a>01260   <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;destport = tmp16;
<a name="l01261"></a>01261   
<a name="l01262"></a>01262   <span class="comment">/* Swap IP addresses. */</span>
<a name="l01263"></a>01263   <a class="code" href="a00148.html#g769512993b7b27271909d6daa4748b60">uip_ipaddr_copy</a>(<a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;destipaddr, <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;srcipaddr);
<a name="l01264"></a>01264   <a class="code" href="a00148.html#g769512993b7b27271909d6daa4748b60">uip_ipaddr_copy</a>(<a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;srcipaddr, <a class="code" href="a00150.html#g7d3673f52f5846b6961d23b150decd54">uip_hostaddr</a>);
<a name="l01265"></a>01265   
<a name="l01266"></a>01266   <span class="comment">/* And send out the RST packet! */</span>
<a name="l01267"></a>01267   <span class="keywordflow">goto</span> tcp_send_noconn;
<a name="l01268"></a>01268 
<a name="l01269"></a>01269   <span class="comment">/* This label will be jumped to if we matched the incoming packet</span>
<a name="l01270"></a>01270 <span class="comment">     with a connection in LISTEN. In that case, we should create a new</span>
<a name="l01271"></a>01271 <span class="comment">     connection and send a SYNACK in return. */</span>
<a name="l01272"></a>01272  found_listen:
<a name="l01273"></a>01273   <span class="comment">/* First we check if there are any connections avaliable. Unused</span>
<a name="l01274"></a>01274 <span class="comment">     connections are kept in the same table as used connections, but</span>
<a name="l01275"></a>01275 <span class="comment">     unused ones have the tcpstate set to CLOSED. Also, connections in</span>
<a name="l01276"></a>01276 <span class="comment">     TIME_WAIT are kept track of and we'll use the oldest one if no</span>
<a name="l01277"></a>01277 <span class="comment">     CLOSED connections are found. Thanks to Eddie C. Dost for a very</span>
<a name="l01278"></a>01278 <span class="comment">     nice algorithm for the TIME_WAIT search. */</span>
<a name="l01279"></a>01279   uip_connr = 0;
<a name="l01280"></a>01280   <span class="keywordflow">for</span>(c = 0; c &lt; <a class="code" href="a00153.html#gf5fe83be78b78b9e7d9e7f1e34ab1cc5">UIP_CONNS</a>; ++c) {
<a name="l01281"></a>01281     <span class="keywordflow">if</span>(<a class="code" href="a00150.html#gf703683056d2bfa5c81fa157dcb20fe2">uip_conns</a>[c].<a class="code" href="a00088.html#a5f58074435cdc180f17de69651beebd">tcpstateflags</a> == <a class="code" href="a00150.html#g28eda870cff3d8e3cf2949e6f57a502b">UIP_CLOSED</a>) {
<a name="l01282"></a>01282       uip_connr = &amp;<a class="code" href="a00150.html#gf703683056d2bfa5c81fa157dcb20fe2">uip_conns</a>[c];
<a name="l01283"></a>01283       <span class="keywordflow">break</span>;
<a name="l01284"></a>01284     }
<a name="l01285"></a>01285     <span class="keywordflow">if</span>(<a class="code" href="a00150.html#gf703683056d2bfa5c81fa157dcb20fe2">uip_conns</a>[c].<a class="code" href="a00088.html#a5f58074435cdc180f17de69651beebd">tcpstateflags</a> == <a class="code" href="a00150.html#gfff0ed43201bf1e2020de1a0d6cac070">UIP_TIME_WAIT</a>) {
<a name="l01286"></a>01286       <span class="keywordflow">if</span>(uip_connr == 0 ||
<a name="l01287"></a>01287          <a class="code" href="a00150.html#gf703683056d2bfa5c81fa157dcb20fe2">uip_conns</a>[c].<a class="code" href="a00087.html">timer</a> &gt; uip_connr-&gt;<a class="code" href="a00088.html#2d9732cf5752d30bd11cb25dc7d0c8d3">timer</a>) {
<a name="l01288"></a>01288         uip_connr = &amp;<a class="code" href="a00150.html#gf703683056d2bfa5c81fa157dcb20fe2">uip_conns</a>[c];
<a name="l01289"></a>01289       }
<a name="l01290"></a>01290     }
<a name="l01291"></a>01291   }
<a name="l01292"></a>01292 
<a name="l01293"></a>01293   <span class="keywordflow">if</span>(uip_connr == 0) {
<a name="l01294"></a>01294     <span class="comment">/* All connections are used already, we drop packet and hope that</span>
<a name="l01295"></a>01295 <span class="comment">       the remote end will retransmit the packet at a time when we</span>
<a name="l01296"></a>01296 <span class="comment">       have more spare connections. */</span>
<a name="l01297"></a>01297     <a class="code" href="a00150.html#g9c0814ed491fa452ec97910c0728d410">UIP_STAT</a>(++<a class="code" href="a00150.html#g9ee50a40597e67fce96541ab56c3b712">uip_stat</a>.<a class="code" href="a00093.html#e292b8977f6b81265bf14e1676face3e">tcp</a>.<a class="code" href="a00093.html#494ea6767a8a8fab7abe96b799d6c3b3">syndrop</a>);
<a name="l01298"></a>01298     <a class="code" href="a00150.html#g013c3a06a8b58589a77f4a3442f89c2a">UIP_LOG</a>(<span class="stringliteral">"tcp: found no unused connections."</span>);
<a name="l01299"></a>01299     <span class="keywordflow">goto</span> drop;
<a name="l01300"></a>01300   }
<a name="l01301"></a>01301   <a class="code" href="a00088.html">uip_conn</a> = uip_connr;
<a name="l01302"></a>01302   
<a name="l01303"></a>01303   <span class="comment">/* Fill in the necessary fields for the new connection. */</span>
<a name="l01304"></a>01304   uip_connr-&gt;rto = uip_connr-&gt;timer = <a class="code" href="a00153.html#g15de27b044603284f68db05a378235a7">UIP_RTO</a>;
<a name="l01305"></a>01305   uip_connr-&gt;sa = 0;
<a name="l01306"></a>01306   uip_connr-&gt;sv = 4;
<a name="l01307"></a>01307   uip_connr-&gt;nrtx = 0;
<a name="l01308"></a>01308   uip_connr-&gt;lport = <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;destport;
<a name="l01309"></a>01309   uip_connr-&gt;rport = <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;srcport;
<a name="l01310"></a>01310   <a class="code" href="a00148.html#g769512993b7b27271909d6daa4748b60">uip_ipaddr_copy</a>(uip_connr-&gt;ripaddr, <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;srcipaddr);
<a name="l01311"></a>01311   uip_connr-&gt;tcpstateflags = <a class="code" href="a00150.html#ga5e3c856b86725125d19fccc34cd9eb5">UIP_SYN_RCVD</a>;
<a name="l01312"></a>01312 
<a name="l01313"></a>01313   uip_connr-&gt;snd_nxt[0] = iss[0];
<a name="l01314"></a>01314   uip_connr-&gt;snd_nxt[1] = iss[1];
<a name="l01315"></a>01315   uip_connr-&gt;snd_nxt[2] = iss[2];
<a name="l01316"></a>01316   uip_connr-&gt;snd_nxt[3] = iss[3];
<a name="l01317"></a>01317   uip_connr-&gt;len = 1;
<a name="l01318"></a>01318 
<a name="l01319"></a>01319   <span class="comment">/* rcv_nxt should be the seqno from the incoming packet + 1. */</span>
<a name="l01320"></a>01320   uip_connr-&gt;rcv_nxt[3] = <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;seqno[3];
<a name="l01321"></a>01321   uip_connr-&gt;rcv_nxt[2] = <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;seqno[2];
<a name="l01322"></a>01322   uip_connr-&gt;rcv_nxt[1] = <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;seqno[1];
<a name="l01323"></a>01323   uip_connr-&gt;rcv_nxt[0] = <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;seqno[0];
<a name="l01324"></a>01324   uip_add_rcv_nxt(1);
<a name="l01325"></a>01325 
<a name="l01326"></a>01326   <span class="comment">/* Parse the TCP MSS option, if present. */</span>
<a name="l01327"></a>01327   <span class="keywordflow">if</span>((<a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;tcpoffset &amp; 0xf0) &gt; 0x50) {
<a name="l01328"></a>01328     <span class="keywordflow">for</span>(c = 0; c &lt; ((<a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;tcpoffset &gt;&gt; 4) - 5) &lt;&lt; 2 ;) {
<a name="l01329"></a>01329       opt = <a class="code" href="a00146.html#gb81e78f890dbbee50c533a9734b74fd9">uip_buf</a>[<a class="code" href="a00150.html#gee37386b2ab828787c05227eb109def7">UIP_TCPIP_HLEN</a> + <a class="code" href="a00153.html#ge6f4a2453dbd8bc60e6a82774552366a">UIP_LLH_LEN</a> + c];
<a name="l01330"></a>01330       <span class="keywordflow">if</span>(opt == <a class="code" href="a00150.html#g1215163245304bad20d6c5608ad75ab7">TCP_OPT_END</a>) {
<a name="l01331"></a>01331         <span class="comment">/* End of options. */</span>
<a name="l01332"></a>01332         <span class="keywordflow">break</span>;
<a name="l01333"></a>01333       } <span class="keywordflow">else</span> <span class="keywordflow">if</span>(opt == <a class="code" href="a00150.html#g9f1822e1d231235edacad691f3cb7bbb">TCP_OPT_NOOP</a>) {
<a name="l01334"></a>01334         ++c;
<a name="l01335"></a>01335         <span class="comment">/* NOP option. */</span>
<a name="l01336"></a>01336       } <span class="keywordflow">else</span> <span class="keywordflow">if</span>(opt == <a class="code" href="a00150.html#g691688604655ea8943d15f14c60027d8">TCP_OPT_MSS</a> &amp;&amp;
<a name="l01337"></a>01337                 <a class="code" href="a00146.html#gb81e78f890dbbee50c533a9734b74fd9">uip_buf</a>[<a class="code" href="a00150.html#gee37386b2ab828787c05227eb109def7">UIP_TCPIP_HLEN</a> + <a class="code" href="a00153.html#ge6f4a2453dbd8bc60e6a82774552366a">UIP_LLH_LEN</a> + 1 + c] == <a class="code" href="a00150.html#g12f3bf821224b8e7b48a57ed3cea15cf">TCP_OPT_MSS_LEN</a>) {
<a name="l01338"></a>01338         <span class="comment">/* An MSS option with the right option length. */</span>
<a name="l01339"></a>01339         tmp16 = ((<a class="code" href="a00153.html#g77570ac4fcab86864fa1916e55676da2">u16_t</a>)<a class="code" href="a00146.html#gb81e78f890dbbee50c533a9734b74fd9">uip_buf</a>[<a class="code" href="a00150.html#gee37386b2ab828787c05227eb109def7">UIP_TCPIP_HLEN</a> + <a class="code" href="a00153.html#ge6f4a2453dbd8bc60e6a82774552366a">UIP_LLH_LEN</a> + 2 + c] &lt;&lt; 8) |
<a name="l01340"></a>01340           (<a class="code" href="a00153.html#g77570ac4fcab86864fa1916e55676da2">u16_t</a>)<a class="code" href="a00146.html#gb81e78f890dbbee50c533a9734b74fd9">uip_buf</a>[<a class="code" href="a00150.html#g15f2617f7dc1713f9d10282125c6027b">UIP_IPTCPH_LEN</a> + <a class="code" href="a00153.html#ge6f4a2453dbd8bc60e6a82774552366a">UIP_LLH_LEN</a> + 3 + c];
<a name="l01341"></a>01341         uip_connr-&gt;initialmss = uip_connr-&gt;mss =
<a name="l01342"></a>01342           tmp16 &gt; <a class="code" href="a00153.html#g4910467b83a639f06739c82cd362037e">UIP_TCP_MSS</a>? <a class="code" href="a00153.html#g4910467b83a639f06739c82cd362037e">UIP_TCP_MSS</a>: tmp16;
<a name="l01343"></a>01343         
<a name="l01344"></a>01344         <span class="comment">/* And we are done processing options. */</span>
<a name="l01345"></a>01345         <span class="keywordflow">break</span>;
<a name="l01346"></a>01346       } <span class="keywordflow">else</span> {
<a name="l01347"></a>01347         <span class="comment">/* All other options have a length field, so that we easily</span>
<a name="l01348"></a>01348 <span class="comment">           can skip past them. */</span>
<a name="l01349"></a>01349         <span class="keywordflow">if</span>(<a class="code" href="a00146.html#gb81e78f890dbbee50c533a9734b74fd9">uip_buf</a>[<a class="code" href="a00150.html#gee37386b2ab828787c05227eb109def7">UIP_TCPIP_HLEN</a> + <a class="code" href="a00153.html#ge6f4a2453dbd8bc60e6a82774552366a">UIP_LLH_LEN</a> + 1 + c] == 0) {
<a name="l01350"></a>01350           <span class="comment">/* If the length field is zero, the options are malformed</span>
<a name="l01351"></a>01351 <span class="comment">             and we don't process them further. */</span>
<a name="l01352"></a>01352           <span class="keywordflow">break</span>;
<a name="l01353"></a>01353         }
<a name="l01354"></a>01354         c += <a class="code" href="a00146.html#gb81e78f890dbbee50c533a9734b74fd9">uip_buf</a>[<a class="code" href="a00150.html#gee37386b2ab828787c05227eb109def7">UIP_TCPIP_HLEN</a> + <a class="code" href="a00153.html#ge6f4a2453dbd8bc60e6a82774552366a">UIP_LLH_LEN</a> + 1 + c];
<a name="l01355"></a>01355       }
<a name="l01356"></a>01356     }
<a name="l01357"></a>01357   }
<a name="l01358"></a>01358   
<a name="l01359"></a>01359   <span class="comment">/* Our response will be a SYNACK. */</span>
<a name="l01360"></a>01360 <span class="preprocessor">#if UIP_ACTIVE_OPEN</span>
<a name="l01361"></a>01361 <span class="preprocessor"></span> tcp_send_synack:
<a name="l01362"></a>01362   <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;flags = <a class="code" href="a00150.html#g44b3b1ab31a403ba28ec135adfcbefef">TCP_ACK</a>;
<a name="l01363"></a>01363   
<a name="l01364"></a>01364  tcp_send_syn:
<a name="l01365"></a>01365   <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;flags |= <a class="code" href="a00150.html#g6020613f5062417d9811cfa837215c83">TCP_SYN</a>;
<a name="l01366"></a>01366 <span class="preprocessor">#else </span><span class="comment">/* UIP_ACTIVE_OPEN */</span>
<a name="l01367"></a>01367  tcp_send_synack:
<a name="l01368"></a>01368   <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;flags = <a class="code" href="a00150.html#g6020613f5062417d9811cfa837215c83">TCP_SYN</a> | <a class="code" href="a00150.html#g44b3b1ab31a403ba28ec135adfcbefef">TCP_ACK</a>;
<a name="l01369"></a>01369 <span class="preprocessor">#endif </span><span class="comment">/* UIP_ACTIVE_OPEN */</span>
<a name="l01370"></a>01370   
<a name="l01371"></a>01371   <span class="comment">/* We send out the TCP Maximum Segment Size option with our</span>
<a name="l01372"></a>01372 <span class="comment">     SYNACK. */</span>
<a name="l01373"></a>01373   <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;optdata[0] = <a class="code" href="a00150.html#g691688604655ea8943d15f14c60027d8">TCP_OPT_MSS</a>;
<a name="l01374"></a>01374   <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;optdata[1] = <a class="code" href="a00150.html#g12f3bf821224b8e7b48a57ed3cea15cf">TCP_OPT_MSS_LEN</a>;
<a name="l01375"></a>01375   <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;optdata[2] = (<a class="code" href="a00153.html#g4910467b83a639f06739c82cd362037e">UIP_TCP_MSS</a>) / 256;
<a name="l01376"></a>01376   <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;optdata[3] = (<a class="code" href="a00153.html#g4910467b83a639f06739c82cd362037e">UIP_TCP_MSS</a>) &amp; 255;
<a name="l01377"></a>01377   <a class="code" href="a00149.html#g12a33f0c09711167bdf3dd7d7cf8c5a1">uip_len</a> = <a class="code" href="a00150.html#g15f2617f7dc1713f9d10282125c6027b">UIP_IPTCPH_LEN</a> + <a class="code" href="a00150.html#g12f3bf821224b8e7b48a57ed3cea15cf">TCP_OPT_MSS_LEN</a>;
<a name="l01378"></a>01378   <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;tcpoffset = ((<a class="code" href="a00150.html#g17d111686f98e4c09db73a770ac3f1a4">UIP_TCPH_LEN</a> + TCP_OPT_MSS_LEN) / 4) &lt;&lt; 4;
<a name="l01379"></a>01379   <span class="keywordflow">goto</span> tcp_send;
<a name="l01380"></a>01380 
<a name="l01381"></a>01381   <span class="comment">/* This label will be jumped to if we found an active connection. */</span>
<a name="l01382"></a>01382  found:
<a name="l01383"></a>01383   <a class="code" href="a00088.html">uip_conn</a> = uip_connr;
<a name="l01384"></a>01384   <a class="code" href="a00150.html#gb4ef6b00924990e7a293f66715b6d1d1">uip_flags</a> = 0;
<a name="l01385"></a>01385   <span class="comment">/* We do a very naive form of TCP reset processing; we just accept</span>
<a name="l01386"></a>01386 <span class="comment">     any RST and kill our connection. We should in fact check if the</span>
<a name="l01387"></a>01387 <span class="comment">     sequence number of this reset is wihtin our advertised window</span>
<a name="l01388"></a>01388 <span class="comment">     before we accept the reset. */</span>
<a name="l01389"></a>01389   <span class="keywordflow">if</span>(<a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;flags &amp; <a class="code" href="a00150.html#g5ca559def464ef20d8b1f7d32f2f160d">TCP_RST</a>) {
<a name="l01390"></a>01390     uip_connr-&gt;tcpstateflags = <a class="code" href="a00150.html#g28eda870cff3d8e3cf2949e6f57a502b">UIP_CLOSED</a>;
<a name="l01391"></a>01391     <a class="code" href="a00150.html#g013c3a06a8b58589a77f4a3442f89c2a">UIP_LOG</a>(<span class="stringliteral">"tcp: got reset, aborting connection."</span>);
<a name="l01392"></a>01392     <a class="code" href="a00150.html#gb4ef6b00924990e7a293f66715b6d1d1">uip_flags</a> = <a class="code" href="a00150.html#ga4c4310e54f18541b09e1e251fe7b22d">UIP_ABORT</a>;
<a name="l01393"></a>01393     <a class="code" href="a00153.html#g41aa744caa46913b3b3aedb2a4e78546">UIP_APPCALL</a>();
<a name="l01394"></a>01394     <span class="keywordflow">goto</span> drop;
<a name="l01395"></a>01395   }
<a name="l01396"></a>01396   <span class="comment">/* Calculated the length of the data, if the application has sent</span>
<a name="l01397"></a>01397 <span class="comment">     any data to us. */</span>
<a name="l01398"></a>01398   c = (<a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;tcpoffset &gt;&gt; 4) &lt;&lt; 2;
<a name="l01399"></a>01399   <span class="comment">/* uip_len will contain the length of the actual TCP data. This is</span>
<a name="l01400"></a>01400 <span class="comment">     calculated by subtracing the length of the TCP header (in</span>
<a name="l01401"></a>01401 <span class="comment">     c) and the length of the IP header (20 bytes). */</span>
<a name="l01402"></a>01402   <a class="code" href="a00149.html#g12a33f0c09711167bdf3dd7d7cf8c5a1">uip_len</a> = <a class="code" href="a00149.html#g12a33f0c09711167bdf3dd7d7cf8c5a1">uip_len</a> - c - <a class="code" href="a00150.html#g6bc12c6c7b56f73ce5d57abfdcdc6eb5">UIP_IPH_LEN</a>;
<a name="l01403"></a>01403 
<a name="l01404"></a>01404   <span class="comment">/* First, check if the sequence number of the incoming packet is</span>
<a name="l01405"></a>01405 <span class="comment">     what we're expecting next. If not, we send out an ACK with the</span>
<a name="l01406"></a>01406 <span class="comment">     correct numbers in. */</span>
<a name="l01407"></a>01407   <span class="keywordflow">if</span>(!(((uip_connr-&gt;tcpstateflags &amp; <a class="code" href="a00150.html#g13dfcb4a5f920e108253ade527a66cc2">UIP_TS_MASK</a>) == <a class="code" href="a00150.html#g8af482dec973db57d8b3bd3f69461488">UIP_SYN_SENT</a>) &amp;&amp;
<a name="l01408"></a>01408        ((<a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;flags &amp; <a class="code" href="a00150.html#g1425d4a0c2760adb653a04c0fb137a8d">TCP_CTL</a>) == (<a class="code" href="a00150.html#g6020613f5062417d9811cfa837215c83">TCP_SYN</a> | <a class="code" href="a00150.html#g44b3b1ab31a403ba28ec135adfcbefef">TCP_ACK</a>)))) {
<a name="l01409"></a>01409     <span class="keywordflow">if</span>((<a class="code" href="a00149.html#g12a33f0c09711167bdf3dd7d7cf8c5a1">uip_len</a> &gt; 0 || ((<a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;flags &amp; (<a class="code" href="a00150.html#g6020613f5062417d9811cfa837215c83">TCP_SYN</a> | <a class="code" href="a00150.html#g88e60aa2cf23e1c65d630701db08c743">TCP_FIN</a>)) != 0)) &amp;&amp;
<a name="l01410"></a>01410        (<a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;seqno[0] != uip_connr-&gt;rcv_nxt[0] ||
<a name="l01411"></a>01411         <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;seqno[1] != uip_connr-&gt;rcv_nxt[1] ||
<a name="l01412"></a>01412         <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;seqno[2] != uip_connr-&gt;rcv_nxt[2] ||
<a name="l01413"></a>01413         <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;seqno[3] != uip_connr-&gt;rcv_nxt[3])) {
<a name="l01414"></a>01414       <span class="keywordflow">goto</span> tcp_send_ack;
<a name="l01415"></a>01415     }
<a name="l01416"></a>01416   }
<a name="l01417"></a>01417 
<a name="l01418"></a>01418   <span class="comment">/* Next, check if the incoming segment acknowledges any outstanding</span>
<a name="l01419"></a>01419 <span class="comment">     data. If so, we update the sequence number, reset the length of</span>
<a name="l01420"></a>01420 <span class="comment">     the outstanding data, calculate RTT estimations, and reset the</span>
<a name="l01421"></a>01421 <span class="comment">     retransmission timer. */</span>
<a name="l01422"></a>01422   <span class="keywordflow">if</span>((<a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;flags &amp; <a class="code" href="a00150.html#g44b3b1ab31a403ba28ec135adfcbefef">TCP_ACK</a>) &amp;&amp; <a class="code" href="a00147.html#gef14e83c046e19ab9fe9d1bbcca276c2">uip_outstanding</a>(uip_connr)) {
<a name="l01423"></a>01423     <a class="code" href="a00150.html#g6832e4d2d046536b6472f7ac92340f68">uip_add32</a>(uip_connr-&gt;snd_nxt, uip_connr-&gt;len);
<a name="l01424"></a>01424 
<a name="l01425"></a>01425     <span class="keywordflow">if</span>(<a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;ackno[0] == <a class="code" href="a00151.html#g2a0cf5d86c58fab216414ce59bf1fea1">uip_acc32</a>[0] &amp;&amp;
<a name="l01426"></a>01426        <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;ackno[1] == <a class="code" href="a00151.html#g2a0cf5d86c58fab216414ce59bf1fea1">uip_acc32</a>[1] &amp;&amp;
<a name="l01427"></a>01427        <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;ackno[2] == <a class="code" href="a00151.html#g2a0cf5d86c58fab216414ce59bf1fea1">uip_acc32</a>[2] &amp;&amp;
<a name="l01428"></a>01428        <a class="code" href="a00150.html#g24f52ac52d6e714cb04a5aa01be3bdd0">BUF</a>-&gt;ackno[3] == <a class="code" href="a00151.html#g2a0cf5d86c58fab216414ce59bf1fea1">uip_acc32</a>[3]) {
<a name="l01429"></a>01429       <span class="comment">/* Update sequence number. */</span>
<a name="l01430"></a>01430       uip_connr-&gt;snd_nxt[0] = <a class="code" href="a00151.html#g2a0cf5d86c58fab216414ce59bf1fea1">uip_acc32</a>[0];
<a name="l01431"></a>01431       uip_connr-&gt;snd_nxt[1] = <a class="code" href="a00151.html#g2a0cf5d86c58fab216414ce59bf1fea1">uip_acc32</a>[1];
<a name="l01432"></a>01432       uip_connr-&gt;snd_nxt[2] = <a class="code" href="a00151.html#g2a0cf5d86c58fab216414ce59bf1fea1">uip_acc32</a>[2];
<a name="l01433"></a>01433       uip_connr-&gt;snd_nxt[3] = <a class="code" href="a00151.html#g2a0cf5d86c58fab216414ce59bf1fea1">uip_acc32</a>[3];
<a name="l01434"></a>01434         
<a name="l01435"></a>01435 
<a name="l01436"></a>01436       <span class="comment">/* Do RTT estimation, unless we have done retransmissions. */</span>
<a name="l01437"></a>01437       <span class="keywordflow">if</span>(uip_connr-&gt;nrtx == 0) {
<a name="l01438"></a>01438         <span class="keywordtype">signed</span> <span class="keywordtype">char</span> m;
<a name="l01439"></a>01439         m = uip_connr-&gt;rto - uip_connr-&gt;timer;
<a name="l01440"></a>01440         <span class="comment">/* This is taken directly from VJs original code in his paper */</span>
<a name="l01441"></a>01441         m = m - (uip_connr-&gt;sa &gt;&gt; 3);
<a name="l01442"></a>01442         uip_connr-&gt;sa += m;
<a name="l01443"></a>01443         <span class="keywordflow">if</span>(m &lt; 0) {
<a name="l01444"></a>01444           m = -m;
<a name="l01445"></a>01445         }
<a name="l01446"></a>01446         m = m - (uip_connr-&gt;sv &gt;&gt; 2);
<a name="l01447"></a>01447         uip_connr-&gt;sv += m;
<a name="l01448"></a>01448         uip_connr-&gt;rto = (uip_connr-&gt;sa &gt;&gt; 3) + uip_connr-&gt;sv;
<a name="l01449"></a>01449 
<a name="l01450"></a>01450       }
<a name="l01451"></a>01451       <span class="comment">/* Set the acknowledged flag. */</span>
<a name="l01452"></a>01452       <a class="code" href="a00150.html#gb4ef6b00924990e7a293f66715b6d1d1">uip_flags</a> = <a class="code" href="a00150.html#g6bfa488f87f68a6f7f4a3efb9e45eaf8">UIP_ACKDATA</a>;
<a name="l01453"></a>01453       <span class="comment">/* Reset the retransmission timer. */</span>
<a name="l01454"></a>01454       uip_connr-&gt;timer = uip_connr-&gt;rto;
<a name="l01455"></a>01455 
<a name="l01456"></a>01456       <span class="comment">/* Reset length of outstanding data. */</span>
<a name="l01457"></a>01457       uip_connr-&gt;len = 0;
<a name="l01458"></a>01458     }
<a name="l01459"></a>01459     
<a name="l01460"></a>01460   }
<a name="l01461"></a>01461 
<a name="l01462"></a>01462   <span class="comment">/* Do different things depending on in what state the connection is. */</span>
<a name="l01463"></a>01463   <span class="keywordflow">switch</span>(uip_connr-&gt;tcpstateflags &amp; <a class="code" href="a00150.html#g13dfcb4a5f920e108253ade527a66cc2">UIP_TS_MASK</a>) {
<a name="l01464"></a>01464     <span class="comment">/* CLOSED and LISTEN are not handled here. CLOSE_WAIT is not</span>
<a name="l01465"></a>01465 <span class="comment">        implemented, since we force the application to close when the</span>
<a name="l01466"></a>01466 <span class="comment">        peer sends a FIN (hence the application goes directly from</span>
<a name="l01467"></a>01467 <span class="comment">        ESTABLISHED to LAST_ACK). */</span>
<a name="l01468"></a>01468   <span class="keywordflow">case</span> <a class="code" href="a00150.html#ga5e3c856b86725125d19fccc34cd9eb5">UIP_SYN_RCVD</a>:
<a name="l01469"></a>01469     <span class="comment">/* In SYN_RCVD we have sent out a SYNACK in response to a SYN, and</span>
<a name="l01470"></a>01470 <span class="comment">       we are waiting for an ACK that acknowledges the data we sent</span>
<a name="l01471"></a>01471 <span class="comment">       out the last time. Therefore, we want to have the UIP_ACKDATA</span>
<a name="l01472"></a>01472 <span class="comment">       flag set. If so, we enter the ESTABLISHED state. */</span>
<a name="l01473"></a>01473     <span class="keywordflow">if</span>(<a class="code" href="a00150.html#gb4ef6b00924990e7a293f66715b6d1d1">uip_flags</a> &amp; <a class="code" href="a00150.html#g6bfa488f87f68a6f7f4a3efb9e45eaf8">UIP_ACKDATA</a>) {
<a name="l01474"></a>01474       uip_connr-&gt;tcpstateflags = <a class="code" href="a00150.html#gae59b70658f28ee6e998eaaab05e423f">UIP_ESTABLISHED</a>;
<a name="l01475"></a>01475       <a class="code" href="a00150.html#gb4ef6b00924990e7a293f66715b6d1d1">uip_flags</a> = <a class="code" href="a00150.html#gf84316f469ce0726985c0702db49a989">UIP_CONNECTED</a>;
<a name="l01476"></a>01476       uip_connr-&gt;len = 0;
<a name="l01477"></a>01477       <span class="keywordflow">if</span>(<a class="code" href="a00149.html#g12a33f0c09711167bdf3dd7d7cf8c5a1">uip_len</a> &gt; 0) {
<a name="l01478"></a>01478         <a class="code" href="a00150.html#gb4ef6b00924990e7a293f66715b6d1d1">uip_flags</a> |= <a class="code" href="a00150.html#g39ce739bd352d7e348e37395ce903e43">UIP_NEWDATA</a>;
<a name="l01479"></a>01479         uip_add_rcv_nxt(<a class="code" href="a00149.html#g12a33f0c09711167bdf3dd7d7cf8c5a1">uip_len</a>);
<a name="l01480"></a>01480       }
<a name="l01481"></a>01481       <a class="code" href="a00150.html#g5b5615dc240daed20949c0fded2b4679">uip_slen</a> = 0;
<a name="l01482"></a>01482       <a class="code" href="a00153.html#g41aa744caa46913b3b3aedb2a4e78546">UIP_APPCALL</a>();
<a name="l01483"></a>01483       <span class="keywordflow">goto</span> appsend;
<a name="l01484"></a>01484     }
<a name="l01485"></a>01485     <span class="keywordflow">goto</span> drop;
<a name="l01486"></a>01486 <span class="preprocessor">#if UIP_ACTIVE_OPEN</span>
<a name="l01487"></a>01487 <span class="preprocessor"></span>  <span class="keywordflow">case</span> <a class="code" href="a00150.html#g8af482dec973db57d8b3bd3f69461488">UIP_SYN_SENT</a>:
<a name="l01488"></a>01488     <span class="comment">/* In SYN_SENT, we wait for a SYNACK that is sent in response to</span>
<a name="l01489"></a>01489 <span class="comment">       our SYN. The rcv_nxt is set to sequence number in the SYNACK</span>
<a name="l01490"></a>01490 <span class="comment">       plus one, and we send an ACK. We move into the ESTABLISHED</span>
<a name="l01491"></a>01491 <span class="comment">       state. */</span>
<a name="l01492"></a>01492     <span class="keywordflow">if</span>((<a class="code"