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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html><head><meta http-equiv="Content-Type" content="text/html;charset=iso-8859-1"><title>Procyon AVRlib: net/arp.h Source File</title><link href="dox.css" rel="stylesheet" type="text/css"></head><body><!-- Generated by Doxygen 1.4.2 --><div class="qindex"><a class="qindex" href="main.html">Main Page</a> | <a class="qindex" href="modules.html">Modules</a> | <a class="qindex" href="annotated.html">Data Structures</a> | <a class="qindex" href="dirs.html">Directories</a> | <a class="qindex" href="files.html">File List</a> | <a class="qindex" href="functions.html">Data Fields</a> | <a class="qindex" href="globals.html">Globals</a> | <a class="qindex" href="pages.html">Related Pages</a></div><div class="nav"><a class="el" href="dir_000001.html">net</a></div><h1>arp.h</h1><a href="arp_8h.html">Go to the documentation of this file.</a><div class="fragment"><pre class="fragment">00001 <span class="comment">/*! \file arp.h \brief ARP Protocol Library. */</span>00002 <span class="comment">//*****************************************************************************</span>00003 <span class="comment">//</span>00004 <span class="comment">// File Name : 'arp.h'</span>00005 <span class="comment">// Title : ARP Protocol Library</span>00006 <span class="comment">// Author : Pascal Stang</span>00007 <span class="comment">// Created : 9/7/2004</span>00008 <span class="comment">// Revised : 7/3/2005</span>00009 <span class="comment">// Version : 0.1</span>00010 <span class="comment">// Target MCU : Atmel AVR series</span>00011 <span class="comment">// Editor Tabs : 4</span>00012 <span class="comment">//</span><span class="comment"></span>00013 <span class="comment">/// \ingroup network</span>00014 <span class="comment">/// \defgroup arp ARP Protocol Library (arp.c)</span>00015 <span class="comment">/// \code #include "net/arp.h" \endcode</span>00016 <span class="comment">/// \par Description</span>00017 <span class="comment">/// To send anything over ethernet (or most any other physical network)</span>00018 <span class="comment">/// a packet must be addressed to a physical network node address, often</span>00019 <span class="comment">/// called a MAC/hardware/ethernet address. This MAC address identifies</span>00020 <span class="comment">/// a specific interface (like the ethernet card in your computer) on the</span>00021 <span class="comment">/// network.</span>00022 <span class="comment">/// ARP (Address Resolution Protocol) assists in mapping IP addresses to </span>00023 <span class="comment">/// the MAC addresses required to actually get data to its destination.</span>00024 <span class="comment">/// In other words, an IP address is not enough to send information over</span>00025 <span class="comment">/// ethernet. You need the MAC address of the network interface/card that</span>00026 <span class="comment">/// "owns" that IP address. ARP maintains a table mapping IP addresses to</span>00027 <span class="comment">/// MAC addresses. This table can be filled by both listening to</span>00028 <span class="comment">/// traffic on the network, as well as making specific ARP requests if</span>00029 <span class="comment">/// an IP<->MAC mapping is not in the table.</span>00030 <span class="comment">/// </span>00031 <span class="comment">/// \note This code is currently below version 1.0, and therefore is considered</span>00032 <span class="comment">/// to be lacking in some functionality or documentation, or may not be fully</span>00033 <span class="comment">/// tested. Nonetheless, you can expect most functions to work.</span>00034 <span class="comment">///</span>00035 <span class="comment"></span><span class="comment">// This code is distributed under the GNU Public License</span>00036 <span class="comment">// which can be found at http://www.gnu.org/licenses/gpl.txt</span>00037 <span class="comment">//*****************************************************************************</span><span class="comment"></span>00038 <span class="comment">//@{</span>00039 <span class="comment"></span>00040 <span class="preprocessor">#ifndef ARP_H</span>00041 <span class="preprocessor"></span><span class="preprocessor">#define ARP_H</span>00042 <span class="preprocessor"></span>00043 <span class="preprocessor">#include "<a class="code" href="global_8h.html">global.h</a>"</span>00044 <span class="preprocessor">#include "<a class="code" href="net_8h.html">net.h</a>"</span>00045 00046 <span class="preprocessor">#ifndef ARP_TABLE_SIZE</span>00047 <span class="preprocessor"></span><span class="preprocessor">#define ARP_TABLE_SIZE 8</span>00048 <span class="preprocessor"></span><span class="preprocessor">#endif</span>00049 <span class="preprocessor"></span>00050 <span class="preprocessor">#ifndef ARP_CACHE_TIME_TO_LIVE</span>00051 <span class="preprocessor"></span><span class="preprocessor">#define ARP_CACHE_TIME_TO_LIVE 100</span>00052 <span class="preprocessor"></span><span class="preprocessor">#endif</span>00053 <span class="preprocessor"></span>00054 <span class="comment">//#define ARP_DEBUG_PRINT</span>00055 00056 <span class="comment"></span>00057 <span class="comment">/*! Initialize ARP system.</span>00058 <span class="comment"> Clears ARP table and prepares it for use. This is typically done</span>00059 <span class="comment"> once at program initialization. */</span>00060 <span class="keywordtype">void</span> <a class="code" href="group__arp.html#ga0">arpInit</a>(<span class="keywordtype">void</span>);00061 <span class="comment"></span>00062 <span class="comment">/*! Set IP and Ethernet hardware/MAC address.</span>00063 <span class="comment"> This must be done before valid replies can be generated for ARP</span>00064 <span class="comment"> requests. Typically done once at program initialization. */</span>00065 <span class="keywordtype">void</span> <a class="code" href="group__arp.html#ga1">arpSetAddress</a>(<span class="keyword">struct</span> netEthAddr* myeth, uint32_t myip);00066 <span class="comment"></span>00067 <span class="comment">/*! Processes incoming ARP packets.</span>00068 <span class="comment"> This function is to be called when an ARP type packet has arrived</span>00069 <span class="comment"> over the network. If the packet type is an ARP request for us,</span>00070 <span class="comment"> an ARP reply will be generated and sent. */</span>00071 <span class="keywordtype">void</span> <a class="code" href="group__arp.html#ga2">arpArpIn</a>(<span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> len, <span class="keyword">struct</span> netEthArpHeader* packet);00072 <span class="comment"></span>00073 <span class="comment">/*! Process incoming IP packets to harvest IP<->MAC relationships.</span>00074 <span class="comment"> This function should be called when IP packets are received over the</span>00075 <span class="comment"> network. It does nothing more than harvest the IP<->MAC address</span>00076 <span class="comment"> relationships from the ethernet and IP header of the packet. The</span>00077 <span class="comment"> packet is not changed nor processed. Nothing is sent on the network.</span>00078 <span class="comment"> Use of this command is not required, but it is a good way to</span>00079 <span class="comment"> automatically fill the ARP table with information about nodes that are</span>00080 <span class="comment"> active on the network.</span>00081 <span class="comment"> </span>00082 <span class="comment"> \warning On very busy or heavily populated netorks, this can quickly</span>00083 <span class="comment"> fill the ARP table with unnecessary entries, and/or cause some CPU load.</span>00084 <span class="comment">*/</span>00085 <span class="keywordtype">void</span> <a class="code" href="group__arp.html#ga3">arpIpIn</a>(<span class="keyword">struct</span> netEthIpHeader* packet);00086 <span class="comment"></span>00087 <span class="comment">/*! Process outgoing IP packet to fill in ethernet header information.</span>00088 <span class="comment"> To be sent on a network, an IP packet must have the correct ethernet</span>00089 <span class="comment"> header information appended to the front. This function will fill</span>00090 <span class="comment"> in this information.</span>00091 <span class="comment"> </span>00092 <span class="comment"> A physical destination IP address argument is needed to support</span>00093 <span class="comment"> sending to a gateway (i.e. when a packet is destined for a node that</span>00094 <span class="comment"> is not on this network, IP addressing is as usual, but we phyiscally</span>00095 <span class="comment"> send the packet to the gateway's ethernet address/interface).</span>00096 <span class="comment"> </span>00097 <span class="comment"> \warning Technically, if an IP<->MAC address mapping is not in the</span>00098 <span class="comment"> ARP table, then the IP packet should be held while an ARP request is</span>00099 <span class="comment"> made, and the reply received. However, in single-threaded ram-limited</span>00100 <span class="comment"> embedded systems, such a holdup is unacceptable. This function instead</span>00101 <span class="comment"> sends the packet as an ethernet broadcast if a mapping cannot be found.</span>00102 <span class="comment"></span>00103 <span class="comment"> \todo Send the packet broadcast AND send an ARP request, if a mapping</span>00104 <span class="comment"> is not found.</span>00105 <span class="comment">*/</span>00106 <span class="keywordtype">void</span> <a class="code" href="group__arp.html#ga4">arpIpOut</a>(<span class="keyword">struct</span> netEthIpHeader* packet, uint32_t phyDstIp);00107 <span class="comment"></span>00108 <span class="comment">/*! Periodic ARP cache maintenance.</span>00109 <span class="comment"> This function is to be called once per second and will slowly </span>00110 <span class="comment"> expire old ARP cache entries. */</span>00111 <span class="keywordtype">void</span> <a class="code" href="group__arp.html#ga5">arpTimer</a>(<span class="keywordtype">void</span>);00112 00113 <span class="comment"></span>00114 <span class="comment">/*! Check if this IP address is present in the ARP cache. Internal function.</span>00115 <span class="comment"> If IP address is found, function returns index of entry. If not found,</span>00116 <span class="comment"> returns -1. */</span>00117 <span class="keywordtype">int</span> <a class="code" href="group__arp.html#ga6">arpMatchIp</a>(uint32_t ipaddr);00118 <span class="comment"></span>00119 <span class="comment">//! Print diagnotic information about ARP packet.</span>00120 <span class="comment"></span><span class="keywordtype">void</span> <a class="code" href="group__arp.html#ga7">arpPrintHeader</a>(<span class="keyword">struct</span> netArpHeader* packet);<span class="comment"></span>00121 <span class="comment">//! Print diagnotic information about ARP cache.</span>00122 <span class="comment"></span><span class="keywordtype">void</span> <a class="code" href="group__arp.html#ga8">arpPrintTable</a>(<span class="keywordtype">void</span>);00123 00124 <span class="preprocessor">#endif</span>00125 <span class="preprocessor"></span><span class="comment">//@}</span></span></pre></div><hr size="1"><address style="align: right;"><small>Generated on Sun Oct 29 03:41:07 2006 for Procyon AVRlib by <a href="http://www.doxygen.org/index.html"><img src="doxygen.png" alt="doxygen" align="middle" border="0"></a> 1.4.2 </small></address></body></html>⌨️ 快捷键说明
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