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 <span id="projectnumber">5.4.1</span>
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<div class="fragment"><pre class="fragment"><a name="l00001"></a>00001 <span class="comment">/*</span>
<a name="l00002"></a>00002 <span class="comment"> * Template MIB group implementation - example.c</span>
<a name="l00003"></a>00003 <span class="comment"> *</span>
<a name="l00004"></a>00004 <span class="comment"> */</span>
<a name="l00005"></a>00005
<a name="l00006"></a>00006 <span class="comment">/*</span>
<a name="l00007"></a>00007 <span class="comment"> * include important headers </span>
<a name="l00008"></a>00008 <span class="comment"> */</span>
<a name="l00009"></a>00009 <span class="preprocessor">#include <net-snmp/net-snmp-config.h></span>
<a name="l00010"></a>00010 <span class="preprocessor">#if HAVE_STDLIB_H</span>
<a name="l00011"></a>00011 <span class="preprocessor"></span><span class="preprocessor">#include <stdlib.h></span>
<a name="l00012"></a>00012 <span class="preprocessor">#endif</span>
<a name="l00013"></a>00013 <span class="preprocessor"></span><span class="preprocessor">#if HAVE_STRING_H</span>
<a name="l00014"></a>00014 <span class="preprocessor"></span><span class="preprocessor">#include <string.h></span>
<a name="l00015"></a>00015 <span class="preprocessor">#else</span>
<a name="l00016"></a>00016 <span class="preprocessor"></span><span class="preprocessor">#include <strings.h></span>
<a name="l00017"></a>00017 <span class="preprocessor">#endif</span>
<a name="l00018"></a>00018 <span class="preprocessor"></span>
<a name="l00019"></a>00019 <span class="comment">/*</span>
<a name="l00020"></a>00020 <span class="comment"> * needed by util_funcs.h </span>
<a name="l00021"></a>00021 <span class="comment"> */</span>
<a name="l00022"></a>00022 <span class="preprocessor">#if TIME_WITH_SYS_TIME</span>
<a name="l00023"></a>00023 <span class="preprocessor"></span><span class="preprocessor"># ifdef WIN32</span>
<a name="l00024"></a>00024 <span class="preprocessor"></span><span class="preprocessor"># include <sys/timeb.h></span>
<a name="l00025"></a>00025 <span class="preprocessor"># else</span>
<a name="l00026"></a>00026 <span class="preprocessor"></span><span class="preprocessor"># include <sys/time.h></span>
<a name="l00027"></a>00027 <span class="preprocessor"># endif</span>
<a name="l00028"></a>00028 <span class="preprocessor"></span><span class="preprocessor"># include <time.h></span>
<a name="l00029"></a>00029 <span class="preprocessor">#else</span>
<a name="l00030"></a>00030 <span class="preprocessor"></span><span class="preprocessor"># if HAVE_SYS_TIME_H</span>
<a name="l00031"></a>00031 <span class="preprocessor"></span><span class="preprocessor"># include <sys/time.h></span>
<a name="l00032"></a>00032 <span class="preprocessor"># else</span>
<a name="l00033"></a>00033 <span class="preprocessor"></span><span class="preprocessor"># include <time.h></span>
<a name="l00034"></a>00034 <span class="preprocessor"># endif</span>
<a name="l00035"></a>00035 <span class="preprocessor"></span><span class="preprocessor">#endif</span>
<a name="l00036"></a>00036 <span class="preprocessor"></span>
<a name="l00037"></a>00037 <span class="preprocessor">#if HAVE_WINSOCK_H</span>
<a name="l00038"></a>00038 <span class="preprocessor"></span><span class="preprocessor">#include <winsock.h></span>
<a name="l00039"></a>00039 <span class="preprocessor">#endif</span>
<a name="l00040"></a>00040 <span class="preprocessor"></span><span class="preprocessor">#if HAVE_NETINET_IN_H</span>
<a name="l00041"></a>00041 <span class="preprocessor"></span><span class="preprocessor">#include <netinet/in.h></span>
<a name="l00042"></a>00042 <span class="preprocessor">#endif</span>
<a name="l00043"></a>00043 <span class="preprocessor"></span>
<a name="l00044"></a>00044 <span class="preprocessor">#include <net-snmp/net-snmp-includes.h></span>
<a name="l00045"></a>00045 <span class="preprocessor">#include <net-snmp/agent/net-snmp-agent-includes.h></span>
<a name="l00046"></a>00046
<a name="l00047"></a>00047 <span class="comment">/*</span>
<a name="l00048"></a>00048 <span class="comment"> * header_generic() comes from here </span>
<a name="l00049"></a>00049 <span class="comment"> */</span>
<a name="l00050"></a>00050 <span class="preprocessor">#include "util_funcs.h"</span>
<a name="l00051"></a>00051
<a name="l00052"></a>00052 <span class="comment">/*</span>
<a name="l00053"></a>00053 <span class="comment"> * include our .h file </span>
<a name="l00054"></a>00054 <span class="comment"> */</span>
<a name="l00055"></a>00055 <span class="preprocessor">#include "example.h"</span>
<a name="l00056"></a>00056
<a name="l00057"></a>00057
<a name="l00058"></a>00058 <span class="comment">/*</span>
<a name="l00059"></a>00059 <span class="comment"> * Certain objects can be set via configuration file directives.</span>
<a name="l00060"></a>00060 <span class="comment"> * These variables hold the values for such objects, as they need to</span>
<a name="l00061"></a>00061 <span class="comment"> * be accessible to both the config handlers, and the callback routine.</span>
<a name="l00062"></a>00062 <span class="comment"> */</span>
<a name="l00063"></a>00063 <span class="preprocessor">#define EXAMPLE_STR_LEN 300</span>
<a name="l00064"></a>00064 <span class="preprocessor"></span><span class="preprocessor">#define EXAMPLE_STR_DEFAULT "life the universe and everything"</span>
<a name="l00065"></a>00065 <span class="preprocessor"></span><span class="keywordtype">int</span> example_int = 42;
<a name="l00066"></a>00066 <span class="keywordtype">char</span> example_str[EXAMPLE_STR_LEN];
<a name="l00067"></a>00067
<a name="l00068"></a>00068 <span class="comment">/*</span>
<a name="l00069"></a>00069 <span class="comment"> * Forward declarations for the config handlers </span>
<a name="l00070"></a>00070 <span class="comment"> */</span>
<a name="l00071"></a>00071 <span class="keywordtype">void</span> example_parse_config_exampleint(<span class="keyword">const</span> <span class="keywordtype">char</span> *token,
<a name="l00072"></a>00072 <span class="keywordtype">char</span> *cptr);
<a name="l00073"></a>00073 <span class="keywordtype">void</span> example_parse_config_examplestr(<span class="keyword">const</span> <span class="keywordtype">char</span> *token,
<a name="l00074"></a>00074 <span class="keywordtype">char</span> *cptr);
<a name="l00075"></a>00075 <span class="keywordtype">void</span> example_free_config_exampleint(<span class="keywordtype">void</span>);
<a name="l00076"></a>00076 <span class="keywordtype">void</span> example_free_config_examplestr(<span class="keywordtype">void</span>);
<a name="l00077"></a>00077
<a name="l00078"></a>00078
<a name="l00079"></a>00079 <span class="comment">/*********************</span>
<a name="l00080"></a>00080 <span class="comment"> *</span>
<a name="l00081"></a>00081 <span class="comment"> * Initialisation & common implementation functions</span>
<a name="l00082"></a>00082 <span class="comment"> *</span>
<a name="l00083"></a>00083 <span class="comment"> *********************/</span>
<a name="l00084"></a>00084
<a name="l00085"></a>00085 <span class="comment">/*</span>
<a name="l00086"></a>00086 <span class="comment"> * This array structure defines a representation of the</span>
<a name="l00087"></a>00087 <span class="comment"> * MIB being implemented.</span>
<a name="l00088"></a>00088 <span class="comment"> *</span>
<a name="l00089"></a>00089 <span class="comment"> * The type of the array is 'struct variableN', where N is</span>
<a name="l00090"></a>00090 <span class="comment"> * large enough to contain the longest OID sub-component</span>
<a name="l00091"></a>00091 <span class="comment"> * being loaded. This will normally be the maximum value</span>
<a name="l00092"></a>00092 <span class="comment"> * of the fifth field in each line. In this case, the second</span>
<a name="l00093"></a>00093 <span class="comment"> * and third entries are both of size 2, so we're using</span>
<a name="l00094"></a>00094 <span class="comment"> * 'struct variable2'</span>
<a name="l00095"></a>00095 <span class="comment"> *</span>
<a name="l00096"></a>00096 <span class="comment"> * The supported values for N are listed in <agent/var_struct.h></span>
<a name="l00097"></a>00097 <span class="comment"> * If the value you need is not listed there, simply use the</span>
<a name="l00098"></a>00098 <span class="comment"> * next largest that is.</span>
<a name="l00099"></a>00099 <span class="comment"> *</span>
<a name="l00100"></a>00100 <span class="comment"> * The format of each line is as follows</span>
<a name="l00101"></a>00101 <span class="comment"> * (using the first entry as an example):</span>
<a name="l00102"></a>00102 <span class="comment"> * 1: EXAMPLESTRING:</span>
<a name="l00103"></a>00103 <span class="comment"> * The magic number defined in the example header file.</span>
<a name="l00104"></a>00104 <span class="comment"> * This is passed to the callback routine and is used</span>
<a name="l00105"></a>00105 <span class="comment"> * to determine which object is being queried.</span>
<a name="l00106"></a>00106 <span class="comment"> * 2: ASN_OCTET_STR:</span>
<a name="l00107"></a>00107 <span class="comment"> * The type of the object.</span>
<a name="l00108"></a>00108 <span class="comment"> * Valid types are listed in <snmp_impl.h></span>
<a name="l00109"></a>00109 <span class="comment"> * 3: RONLY (or RWRITE):</span>
<a name="l00110"></a>00110 <span class="comment"> * Whether this object can be SET or not.</span>
<a name="l00111"></a>00111 <span class="comment"> * 4: var_example:</span>
<a name="l00112"></a>00112 <span class="comment"> * The callback routine, used when the object is queried.</span>
<a name="l00113"></a>00113 <span class="comment"> * This will usually be the same for all objects in a module</span>
<a name="l00114"></a>00114 <span class="comment"> * and is typically defined later in this file.</span>
<a name="l00115"></a>00115 <span class="comment"> * 5: 1:</span>
<a name="l00116"></a>00116 <span class="comment"> * The length of the OID sub-component (the next field)</span>
<a name="l00117"></a>00117 <span class="comment"> * 6: {1}:</span>
<a name="l00118"></a>00118 <span class="comment"> * The OID sub-components of this entry.</span>
<a name="l00119"></a>00119 <span class="comment"> * In other words, the bits of the full OID that differ</span>
<a name="l00120"></a>00120 <span class="comment"> * between the various entries of this array.</span>
<a name="l00121"></a>00121 <span class="comment"> * This value is appended to the common prefix (defined later)</span>
<a name="l00122"></a>00122 <span class="comment"> * to obtain the full OID of each entry.</span>
<a name="l00123"></a>00123 <span class="comment"> */</span>
<a name="l00124"></a>00124 <span class="keyword">struct </span><a class="code" href="structvariable2.html">variable2</a> example_variables[] = {
<a name="l00125"></a>00125 {EXAMPLESTRING, ASN_OCTET_STR, RONLY, var_example, 1, {1}},
<a name="l00126"></a>00126 {EXAMPLEINTEGER, ASN_INTEGER, RWRITE, var_example, 2, {2, 1}},
<a name="l00127"></a>00127 {EXAMPLEOBJECTID, ASN_OBJECT_ID, RONLY, var_example, 2, {2, 2}},
<a name="l00128"></a>00128 {EXAMPLETIMETICKS, ASN_TIMETICKS, RONLY, var_example, 1, {3}},
<a name="l00129"></a>00129 {EXAMPLEIPADDRESS, ASN_IPADDRESS, RONLY, var_example, 1, {4}},
<a name="l00130"></a>00130 {EXAMPLECOUNTER, ASN_COUNTER, RONLY, var_example, 1, {5}},
<a name="l00131"></a>00131 {EXAMPLEGAUGE, ASN_GAUGE, RONLY, var_example, 1, {6}},
<a name="l00132"></a>00132 {EXAMPLETRIGGERTRAP, ASN_INTEGER, RWRITE, var_example, 1, {7}},
<a name="l00133"></a>00133 {EXAMPLETRIGGERTRAP2, ASN_INTEGER, RWRITE, var_example, 1, {8}}
<a name="l00134"></a>00134 };
<a name="l00135"></a>00135
<a name="l00136"></a>00136 <span class="comment">/*</span>
<a name="l00137"></a>00137 <span class="comment"> * This array defines the OID of the top of the mib tree that we're</span>
<a name="l00138"></a>00138 <span class="comment"> * registering underneath.</span>
<a name="l00139"></a>00139 <span class="comment"> * Note that this needs to be the correct size for the OID being </span>
<a name="l00140"></a>00140 <span class="comment"> * registered, so that the length of the OID can be calculated.</span>
<a name="l00141"></a>00141 <span class="comment"> * The format given here is the simplest way to achieve this.</span>
<a name="l00142"></a>00142 <span class="comment"> */</span>
<a name="l00143"></a>00143 oid example_variables_oid[] = { 1, 3, 6, 1, 4, 1, 2021, 254 };
<a name="l00144"></a>00144
<a name="l00145"></a>00145
<a name="l00146"></a>00146
<a name="l00147"></a>00147 <span class="comment">/*</span>
<a name="l00148"></a>00148 <span class="comment"> * This function is called at the time the agent starts up</span>
<a name="l00149"></a>00149 <span class="comment"> * to do any initializations that might be required.</span>
<a name="l00150"></a>00150 <span class="comment"> *</span>
<a name="l00151"></a>00151 <span class="comment"> * In theory it is optional and can be omitted if no</span>
<a name="l00152"></a>00152 <span class="comment"> * initialization is needed. In practise, every module</span>
<a name="l00153"></a>00153 <span class="comment"> * will need to register itself (or the objects being</span>
<a name="l00154"></a>00154 <span class="comment"> * implemented will not appear in the MIB tree), and this</span>
<a name="l00155"></a>00155 <span class="comment"> * registration is typically done here.</span>
<a name="l00156"></a>00156 <span class="comment"> *</span>
<a name="l00157"></a>00157 <span class="comment"> * If this function is added or removed, you must re-run</span>
<a name="l00158"></a>00158 <span class="comment"> * the configure script, to detect this change.</span>
<a name="l00159"></a>00159 <span class="comment"> */</span>
<a name="l00160"></a>00160 <span class="keywordtype">void</span>
<a name="l00161"></a>00161 init_example(<span class="keywordtype">void</span>)
<a name="l00162"></a>00162 {
<a name="l00163"></a>00163 <span class="comment">/*</span>
<a name="l00164"></a>00164 <span class="comment"> * Register ourselves with the agent to handle our mib tree.</span>
<a name="l00165"></a>00165 <span class="comment"> * The arguments are:</span>
<a name="l00166"></a>00166 <span class="comment"> * descr: A short description of the mib group being loaded.</span>
<a name="l00167"></a>00167 <span class="comment"> * var: The variable structure to load.</span>
<a name="l00168"></a>00168 <span class="comment"> * (the name of the variable structure defined above)</span>
<a name="l00169"></a>00169 <span class="comment"> * vartype: The type of this variable structure</span>
<a name="l00170"></a>00170 <span class="comment"> * theoid: The OID pointer this MIB is being registered underneath.</span>
<a name="l00171"></a>00171 <span class="comment"> */</span>
<a name="l00172"></a>00172 REGISTER_MIB(<span class="stringliteral">"example"</span>, example_variables, <a class="code" href="structvariable2.html">variable2</a>,
<a name="l00173"></a>00173 example_variables_oid);
<a name="l00174"></a>00174
<a name="l00175"></a>00175
<a name="l00176"></a>00176 <span class="comment">/*</span>
<a name="l00177"></a>00177 <span class="comment"> * Register config handlers for the two objects that can be set</span>
<a name="l00178"></a>00178 <span class="comment"> * via configuration file directive.</span>
<a name="l00179"></a>00179 <span class="comment"> * Also set a default value for the string object. Note that the</span>
<a name="l00180"></a>00180 <span class="comment"> * example integer variable was initialised above.</span>
<a name="l00181"></a>00181 <span class="comment"> */</span>
<a name="l00182"></a>00182 strncpy(example_str, EXAMPLE_STR_DEFAULT, EXAMPLE_STR_LEN);
<a name="l00183"></a>00183
<a name="l00184"></a>00184 snmpd_register_config_handler(<span class="stringliteral">"exampleint"</span>,
<a name="l00185"></a>00185 example_parse_config_exampleint,
<a name="l00186"></a>00186 example_free_config_exampleint,
<a name="l00187"></a>00187 <span class="stringliteral">"exampleint value"</span>);
<a name="l00188"></a>00188 snmpd_register_config_handler(<span class="stringliteral">"examplestr"</span>,
<a name="l00189"></a>00189 example_parse_config_examplestr,
<a name="l00190"></a>00190 example_free_config_examplestr,
<a name="l00191"></a>00191 <span class="stringliteral">"examplestr value"</span>);
<a name="l00192"></a>00192 snmpd_register_config_handler(<span class="stringliteral">"examplestring"</span>,
<a name="l00193"></a>00193 example_parse_config_examplestr,
<a name="l00194"></a>00194 example_free_config_examplestr,
<a name="l00195"></a>00195 <span class="stringliteral">"examplestring value"</span>);
<a name="l00196"></a>00196
<a name="l00197"></a>00197 <span class="comment">/*</span>
<a name="l00198"></a>00198 <span class="comment"> * One common requirement is to read values from the kernel.</span>
<a name="l00199"></a>00199 <span class="comment"> * This is usually initialised here, to speed up access when the</span>
<a name="l00200"></a>00200 <span class="comment"> * information is read in, as a response to an incoming request.</span>
<a name="l00201"></a>00201 <span class="comment"> *</span>
<a name="l00202"></a>00202 <span class="comment"> * This module doesn't actually use this mechanism,</span>
<a name="l00203"></a>00203 <span class="comment"> * so this call is commented out here.</span>
<a name="l00204"></a>00204 <span class="comment"> */</span>
<a name="l00205"></a>00205 <span class="comment">/*</span>
<a name="l00206"></a>00206 <span class="comment"> * auto_nlist( "example_symbol", 0, 0 ); </span>
<a name="l00207"></a>00207 <span class="comment"> */</span>
<a name="l00208"></a>00208 }
<a name="l00209"></a>00209
<a name="l00210"></a>00210 <span class="comment">/*********************</span>
<a name="l00211"></a>00211 <span class="comment"> *</span>
<a name="l00212"></a>00212 <span class="comment"> * Configuration file handling functions</span>
<a name="l00213"></a>00213 <span class="comment"> *</span>
<a name="l00214"></a>00214 <span class="comment"> *********************/</span>
<a name="l00215"></a>00215
<a name="l00216"></a>00216 <span class="keywordtype">void</span>
<a name="l00217"></a>00217 example_parse_config_exampleint(<span class="keyword">const</span> <span class="keywordtype">char</span> *token, <span class="keywordtype">char</span> *cptr)
<a name="l00218"></a>00218 {
<a name="l00219"></a>00219 example_int = atoi(cptr);
<a name="l00220"></a>00220 }
<a name="l00221"></a>00221
<a name="l00222"></a>00222 <span class="keywordtype">void</span>
<a name="l00223"></a>00223 example_parse_config_examplestr(<span class="keyword">const</span> <span class="keywordtype">char</span> *token, <span class="keywordtype">char</span> *cptr)
<a name="l00224"></a>00224 {
<a name="l00225"></a>00225 <span class="comment">/*</span>
<a name="l00226"></a>00226 <span class="comment"> * Make sure the string fits in the space allocated for it.</span>
<a name="l00227"></a>00227 <span class="comment"> */</span>
<a name="l00228"></a>00228 <span class="keywordflow">if</span> (strlen(cptr) < EXAMPLE_STR_LEN)
<a name="l00229"></a>00229 strcpy(example_str, cptr);
<a name="l00230"></a>00230 <span class="keywordflow">else</span> {
<a name="l00231"></a>00231 <span class="comment">/*</span>
<a name="l00232"></a>00232 <span class="comment"> * Truncate the string if necessary.</span>
<a name="l00233"></a>00233 <span class="comment"> * An alternative approach would be to log an error,</span>
<a name="l00234"></a>00234 <span class="comment"> * and discard this value altogether.</span>
<a name="l00235"></a>00235 <span class="comment"> */</span>
<a name="l00236"></a>00236 strncpy(example_str, cptr, EXAMPLE_STR_LEN - 4);
<a name="l00237"></a>00237 example_str[EXAMPLE_STR_LEN - 4] = 0;
<a name="l00238"></a>00238 strcat(example_str, <span class="stringliteral">"..."</span>);
<a name="l00239"></a>00239 example_str[EXAMPLE_STR_LEN - 1] = 0;
<a name="l00240"></a>00240 }
<a name="l00241"></a>00241 }
<a name="l00242"></a>00242
<a name="l00243"></a>00243 <span class="comment">/*</span>
<a name="l00244"></a>00244 <span class="comment"> * We don't need to do anything special when closing down </span>
<a name="l00245"></a>00245 <span class="comment"> */</span>
<a name="l00246"></a>00246 <span class="keywordtype">void</span>
<a name="l00247"></a>00247 example_free_config_exampleint(<span class="keywordtype">void</span>)
<a name="l00248"></a>00248 {
<a name="l00249"></a>00249 }
<a name="l00250"></a>00250
<a name="l00251"></a>00251 <span class="keywordtype">void</span>
<a name="l00252"></a>00252 example_free_config_examplestr(<span class="keywordtype">void</span>)
<a name="l00253"></a>00253 {
<a name="l00254"></a>00254 }
<a name="l00255"></a>00255
<a name="l00256"></a>00256 <span class="comment">/*********************</span>
<a name="l00257"></a>00257 <span class="comment"> *</span>
<a name="l00258"></a>00258 <span class="comment"> * System specific implementation functions</span>
<a name="l00259"></a>00259 <span class="comment"> *</span>
<a name="l00260"></a>00260 <span class="comment"> *********************/</span>
<a name="l00261"></a>00261
<a name="l00262"></a>00262 <span class="comment">/*</span>
<a name="l00263"></a>00263 <span class="comment"> * Define the callback function used in the example_variables structure.</span>
<a name="l00264"></a>00264 <span class="comment"> * This is called whenever an incoming request refers to an object</span>
<a name="l00265"></a>00265 <span class="comment"> * within this sub-tree.</span>
<a name="l00266"></a>00266 <span class="comment"> *</span>
<a name="l00267"></a>00267 <span class="comment"> * Four of the parameters are used to pass information in.</span>
<a name="l00268"></a>00268 <span class="comment"> * These are:</span>
<a name="l00269"></a>00269 <span class="comment"> * vp The entry from the 'example_variables' array for the</span>
<a name="l00270"></a>00270 <span class="comment"> * object being queried.</span>
<a name="l00271"></a>00271 <span class="comment"> * name The OID from the request.</span>
<a name="l00272"></a>00272 <span class="comment"> * length The length of this OID.</span>
<a name="l00273"></a>00273 <span class="comment"> * exact A flag to indicate whether this is an 'exact' request</span>
<a name="l00274"></a>00274 <span class="comment"> * (GET/SET) or an 'inexact' one (GETNEXT/GETBULK).</span>
<a name="l00275"></a>00275 <span class="comment"> *</span>
<a name="l00276"></a>00276 <span class="comment"> * Four of the parameters are used to pass information back out.</span>
<a name="l00277"></a>00277 <span class="comment"> * These are:</span>
<a name="l00278"></a>00278 <span class="comment"> * name The OID being returned.</span>
<a name="l00279"></a>00279 <span class="comment"> * length The length of this OID.</span>
<a name="l00280"></a>00280 <span class="comment"> * var_len The length of the answer being returned.</span>
<a name="l00281"></a>00281 <span class="comment"> * write_method A pointer to the SET function for this object.</span>
<a name="l00282"></a>00282 <span class="comment"> *</span>
<a name="l00283"></a>00283 <span class="comment"> * Note that name & length serve a dual purpose in both roles.</span>
<a name="l00284"></a>00284 <span class="comment"> */</span>
<a name="l00285"></a>00285
<a name="l00286"></a>00286 u_char *
<a name="l00287"></a>00287 var_example(<span class="keyword">struct</span> <a class="code" href="structvariable.html">variable</a> *vp,
<a name="l00288"></a>00288 oid * name,
<a name="l00289"></a>00289 <span class="keywordtype">size_t</span> * length,
<a name="l00290"></a>00290 <span class="keywordtype">int</span> exact, <span class="keywordtype">size_t</span> * var_len, WriteMethod ** write_method)
<a name="l00291"></a>00291 {
<a name="l00292"></a>00292 <span class="comment">/*</span>
<a name="l00293"></a>00293 <span class="comment"> * The result returned from this function needs to be a pointer to</span>
<a name="l00294"></a>00294 <span class="comment"> * static data (so that it can be accessed from outside).</span>
<a name="l00295"></a>00295 <span class="comment"> * Define suitable variables for any type of data we may return.</span>
<a name="l00296"></a>00296 <span class="comment"> */</span>
<a name="l00297"></a>00297 <span class="keyword">static</span> <span class="keywordtype">char</span> <span class="keywordtype">string</span>[EXAMPLE_STR_LEN]; <span class="comment">/* for EXAMPLESTRING */</span>
<a name="l00298"></a>00298 <span class="keyword">static</span> oid oid_ret[8]; <span class="comment">/* for EXAMPLEOBJECTID */</span>
<a name="l00299"></a>00299 <span class="keyword">static</span> <span class="keywordtype">long</span> long_ret; <span class="comment">/* for everything else */</span>
<a name="l00300"></a>00300
<a name="l00301"></a>00301 <span class="comment">/*</span>
<a name="l00302"></a>00302 <span class="comment"> * Before returning an answer, we need to check that the request</span>
<a name="l00303"></a>00303 <span class="comment"> * refers to a valid instance of this object. The utility routine</span>
<a name="l00304"></a>00304 <span class="comment"> * 'header_generic' can be used to do this for scalar objects.</span>
<a name="l00305"></a>00305 <span class="comment"> *</span>
<a name="l00306"></a>00306 <span class="comment"> * This routine 'header_simple_table' does the same thing for "simple"</span>
<a name="l00307"></a>00307 <span class="comment"> * tables. (See the AGENT.txt file for the definition of a simple table).</span>
<a name="l00308"></a>00308 <span class="comment"> *</span>
<a name="l00309"></a>00309 <span class="comment"> * Both these utility routines also set up default values for the</span>
<a name="l00310"></a>00310 <span class="comment"> * return arguments (assuming the check succeeded).</span>
<a name="l00311"></a>00311 <span class="comment"> * The name and length are set suitably for the current object,</span>
<a name="l00312"></a>00312 <span class="comment"> * var_len assumes that the result is an integer of some form,</span>
<a name="l00313"></a>00313 <span class="comment"> * and write_method assumes that the object cannot be set.</span>
<a name="l00314"></a>00314 <span class="comment"> *</span>
<a name="l00315"></a>00315 <span class="comment"> * If these assumptions are correct, this callback routine simply</span>
<a name="l00316"></a>00316 <span class="comment"> * needs to return a pointer to the appropriate value (using 'long_ret').</span>
<a name="l00317"></a>00317 <span class="comment"> * Otherwise, 'var_len' and/or 'write_method' should be set suitably.</span>
<a name="l00318"></a>00318 <span class="comment"> */</span>
<a name="l00319"></a>00319 DEBUGMSGTL((<span class="stringliteral">"example"</span>, <span class="stringliteral">"var_example entered\n"</span>));
<a name="l00320"></a>00320 <span class="keywordflow">if</span> (header_generic(vp, name, length, exact, var_len, write_method) ==
<a name="l00321"></a>00321 MATCH_FAILED)
<a name="l00322"></a>00322 <span class="keywordflow">return</span> NULL;
<a name="l00323"></a>00323
<a name="l00324"></a>00324
<a name="l00325"></a>00325 <span class="comment">/*</span>
<a name="l00326"></a>00326 <span class="comment"> * Many object will need to obtain data from the operating system in</span>
<a name="l00327"></a>00327 <span class="comment"> * order to return the appropriate value. Typically, this is done</span>
<a name="l00328"></a>00328 <span class="comment"> * here - immediately following the 'header' call, and before the</span>
<a name="l00329"></a>00329 <span class="comment"> * switch statement. This is particularly appropriate if a single </span>
<a name="l00330"></a>00330 <span class="comment"> * interface call can return data for all the objects supported.</span>
<a name="l00331"></a>00331 <span class="comment"> *</span>
<a name="l00332"></a>00332 <span class="comment"> * This example module does not rely on external data, so no such</span>
<a name="l00333"></a>00333 <span class="comment"> * calls are needed in this case. </span>
<a name="l00334"></a>00334 <span class="comment"> */</span>
<a name="l00335"></a>00335
<a name="l00336"></a>00336 <span class="comment">/*</span>
<a name="l00337"></a>00337 <span class="comment"> * Now use the magic number from the variable pointer 'vp' to</span>
<a name="l00338"></a>00338 <span class="comment"> * select the particular object being queried.</span>
<a name="l00339"></a>00339 <span class="comment"> * In each case, one of the static objects is set up with the</span>
<a name="l00340"></a>00340 <span class="comment"> * appropriate information, and returned mapped to a 'u_char *'</span>
<a name="l00341"></a>00341 <span class="comment"> */</span>
<a name="l00342"></a>00342 <span class="keywordflow">switch</span> (vp->magic) {
<a name="l00343"></a>00343 <span class="keywordflow">case</span> EXAMPLESTRING:
<a name="l00344"></a>00344 sprintf(<span class="keywordtype">string</span>, example_str);
<a name="l00345"></a>00345 <span class="comment">/*</span>
<a name="l00346"></a>00346 <span class="comment"> * Note that the assumption that the answer will be an</span>
<a name="l00347"></a>00347 <span class="comment"> * integer does not hold true in this case, so the length</span>
<a name="l00348"></a>00348 <span class="comment"> * of the answer needs to be set explicitly. </span>
<a name="l00349"></a>00349 <span class="comment"> */</span>
<a name="l00350"></a>00350 *var_len = strlen(<span class="keywordtype">string</span>);
<a name="l00351"></a>00351 <span class="keywordflow">return</span> (u_char *) string;
<a name="l00352"></a>00352
<a name="l00353"></a>00353 <span class="keywordflow">case</span> EXAMPLEINTEGER:
<a name="l00354"></a>00354 <span class="comment">/*</span>
<a name="l00355"></a>00355 <span class="comment"> * Here the length assumption is correct, but the</span>
<a name="l00356"></a>00356 <span class="comment"> * object is writeable, so we need to set the</span>
<a name="l00357"></a>00357 <span class="comment"> * write_method pointer as well as the current value.</span>
<a name="l00358"></a>00358 <span class="comment"> */</span>
<a name="l00359"></a>00359 long_ret = example_int;
<a name="l00360"></a>00360 *write_method = write_exampleint;
<a name="l00361"></a>00361 <span class="keywordflow">return</span> (u_char *) & long_ret;
<a name="l00362"></a>00362
<a name="l00363"></a>00363 <span class="keywordflow">case</span> EXAMPLEOBJECTID:
<a name="l00364"></a>00364 oid_ret[0] = 1;
<a name="l00365"></a>00365 oid_ret[1] = 3;
<a name="l00366"></a>00366 oid_ret[2] = 6;
<a name="l00367"></a>00367 oid_ret[3] = 1;
<a name="l00368"></a>00368 oid_ret[4] = 4;
<a name="l00369"></a>00369 oid_ret[5] = oid_ret[6] = oid_ret[7] = 42;
<a name="l00370"></a>00370 <span class="comment">/*</span>
<a name="l00371"></a>00371 <span class="comment"> * Again, the assumption regarding the answer length is wrong.</span>
<a name="l00372"></a>00372 <span class="comment"> */</span>
<a name="l00373"></a>00373 *var_len = 8 * <span class="keyword">sizeof</span>(oid);
<a name="l00374"></a>00374 <span class="keywordflow">return</span> (u_char *) oid_ret;
<a name="l00375"></a>00375
<a name="l00376"></a>00376 <span class="keywordflow">case</span> EXAMPLETIMETICKS:
<a name="l00377"></a>00377 <span class="comment">/*</span>
<a name="l00378"></a>00378 <span class="comment"> * Here both assumptions are correct,</span>
<a name="l00379"></a>00379 <span class="comment"> * so we just need to set up the answer.</span>
<a name="l00380"></a>00380 <span class="comment"> */</span>
<a name="l00381"></a>00381 long_ret = 363136200; <span class="comment">/* 42 days, 42 minutes and 42.0 seconds */</span>
<a name="l00382"></a>00382 <span class="keywordflow">return</span> (u_char *) & long_ret;
<a name="l00383"></a>00383
<a name="l00384"></a>00384 <span class="keywordflow">case</span> EXAMPLEIPADDRESS:
<a name="l00385"></a>00385 <span class="comment">/*</span>
<a name="l00386"></a>00386 <span class="comment"> * ipaddresses get returned as a long. ick </span>
<a name="l00387"></a>00387 <span class="comment"> */</span>
<a name="l00388"></a>00388 <span class="comment">/*</span>
<a name="l00389"></a>00389 <span class="comment"> * we're returning 127.0.0.1 </span>
<a name="l00390"></a>00390 <span class="comment"> */</span>
<a name="l00391"></a>00391 long_ret = ntohl(INADDR_LOOPBACK);
<a name="l00392"></a>00392 <span class="keywordflow">return</span> (u_char *) & long_ret;
<a name="l00393"></a>00393
<a name="l00394"></a>00394 <span class="keywordflow">case</span> EXAMPLECOUNTER:
<a name="l00395"></a>00395 long_ret = 42;
<a name="l00396"></a>00396 <span class="keywordflow">return</span> (u_char *) & long_ret;
<a name="l00397"></a>00397
<a name="l00398"></a>00398 <span class="keywordflow">case</span> EXAMPLEGAUGE:
<a name="l00399"></a>00399 long_ret = 42; <span class="comment">/* Do we detect a theme running through these answers? */</span>
<a name="l00400"></a>00400 <span class="keywordflow">return</span> (u_char *) & long_ret;
<a name="l00401"></a>00401
<a name="l00402"></a>00402 <span class="keywordflow">case</span> EXAMPLETRIGGERTRAP:
<a name="l00403"></a>00403 <span class="comment">/*</span>
<a name="l00404"></a>00404 <span class="comment"> * This object is essentially "write-only".</span>
<a name="l00405"></a>00405 <span class="comment"> * It only exists to trigger the sending of a trap.</span>
<a name="l00406"></a>00406 <span class="comment"> * Reading it will always return 0.</span>
<a name="l00407"></a>00407 <span class="comment"> */</span>
<a name="l00408"></a>00408 long_ret = 0;
<a name="l00409"></a>00409 *write_method = write_exampletrap;
<a name="l00410"></a>00410 <span class="keywordflow">return</span> (u_char *) & long_ret;
<a name="l00411"></a>00411
<a name="l00412"></a>00412 <span class="keywordflow">case</span> EXAMPLETRIGGERTRAP2:
<a name="l00413"></a>00413 <span class="comment">/*</span>
<a name="l00414"></a>00414 <span class="comment"> * This object is essentially "write-only".</span>
<a name="l00415"></a>00415 <span class="comment"> * It only exists to trigger the sending of a v2 trap.</span>
<a name="l00416"></a>00416 <span class="comment"> * Reading it will always return 0.</span>
<a name="l00417"></a>00417 <span class="comment"> */</span>
<a name="l00418"></a>00418 long_ret = 0;
<a name="l00419"></a>00419 *write_method = write_exampletrap2;
<a name="l00420"></a>00420 <span class="keywordflow">return</span> (u_char *) & long_ret;
<a name="l00421"></a>00421
<a name="l00422"></a>00422 <span class="keywordflow">default</span>:
<a name="l00423"></a>00423 <span class="comment">/*</span>
<a name="l00424"></a>00424 <span class="comment"> * This will only be triggered if there's a problem with</span>
<a name="l00425"></a>00425 <span class="comment"> * the coding of the module. SNMP requests that reference</span>
<a name="l00426"></a>00426 <span class="comment"> * a non-existant OID will be directed elsewhere.</span>
<a name="l00427"></a>00427 <span class="comment"> * If this branch is reached, log an error, so that</span>
<a name="l00428"></a>00428 <span class="comment"> * the problem can be investigated.</span>
<a name="l00429"></a>00429 <span class="comment"> */</span>
<a name="l00430"></a>00430 DEBUGMSGTL((<span class="stringliteral">"snmpd"</span>, <span class="stringliteral">"unknown sub-id %d in examples/var_example\n"</span>,
<a name="l00431"></a>00431 vp->magic));
<a name="l00432"></a>00432 }
<a name="l00433"></a>00433 <span class="comment">/*</span>
<a name="l00434"></a>00434 <span class="comment"> * If we fall through to here, fail by returning NULL.</span>
<a name="l00435"></a>00435 <span class="comment"> * This is essentially a continuation of the 'default' case above.</span>
<a name="l00436"></a>00436 <span class="comment"> */</span>
<a name="l00437"></a>00437 <span class="keywordflow">return</span> NULL;
<a name="l00438"></a>00438 }
<a name="l00439"></a>00439
<a name="l00440"></a>00440 <span class="comment">/*********************</span>
<a name="l00441"></a>00441 <span class="comment"> *</span>
<a name="l00442"></a>00442 <span class="comment"> * Writeable object SET handling routines</span>
<a name="l00443"></a>00443 <span class="comment"> *</span>
<a name="l00444"></a>00444 <span class="comment"> *********************/</span>
<a name="l00445"></a>00445 <span class="keywordtype">int</span>
<a name="l00446"></a>00446 write_exampleint(<span class="keywordtype">int</span> action,
<a name="l00447"></a>00447 u_char * var_val,
<a name="l00448"></a>00448 u_char var_val_type,
<a name="l00449"></a>00449 <span class="keywordtype">size_t</span> var_val_len,
<a name="l00450"></a>00450 u_char * statP, oid * name, <span class="keywordtype">size_t</span> name_len)
<a name="l00451"></a>00451 {
<a name="l00452"></a>00452 <span class="comment">/*</span>
<a name="l00453"></a>00453 <span class="comment"> * Define an arbitrary maximum permissible value </span>
<a name="l00454"></a>00454 <span class="comment"> */</span>
<a name="l00455"></a>00455 <span class="preprocessor">#define MAX_EXAMPLE_INT 100</span>
<a name="l00456"></a>00456 <span class="preprocessor"></span> <span class="keyword">static</span> <span class="keywordtype">long</span> intval;
<a name="l00457"></a>00457 <span class="keyword">static</span> <span class="keywordtype">long</span> old_intval;
<a name="l00458"></a>00458
<a name="l00459"></a>00459 <span class="keywordflow">switch</span> (action) {
<a name="l00460"></a>00460 <span class="keywordflow">case</span> RESERVE1:
<a name="l00461"></a>00461 <span class="comment">/*</span>
<a name="l00462"></a>00462 <span class="comment"> * Check that the value being set is acceptable</span>
<a name="l00463"></a>00463 <span class="comment"> */</span>
<a name="l00464"></a>00464 <span class="keywordflow">if</span> (var_val_type != ASN_INTEGER) {
<a name="l00465"></a>00465 DEBUGMSGTL((<span class="stringliteral">"example"</span>, <span class="stringliteral">"%x not integer type"</span>, var_val_type));
<a name="l00466"></a>00466 <span class="keywordflow">return</span> SNMP_ERR_WRONGTYPE;
<a name="l00467"></a>00467 }
<a name="l00468"></a>00468 <span class="keywordflow">if</span> (var_val_len > <span class="keyword">sizeof</span>(<span class="keywordtype">long</span>)) {
<a name="l00469"></a>00469 DEBUGMSGTL((<span class="stringliteral">"example"</span>, <span class="stringliteral">"wrong length %x"</span>, var_val_len));
<a name="l00470"></a>00470 <span class="keywordflow">return</span> SNMP_ERR_WRONGLENGTH;
<a name="l00471"></a>00471 }
<a name="l00472"></a>00472
<a name="l00473"></a>00473 intval = *((<span class="keywordtype">long</span> *) var_val);
<a name="l00474"></a>00474 <span class="keywordflow">if</span> (intval > MAX_EXAMPLE_INT) {
<a name="l00475"></a>00475 DEBUGMSGTL((<span class="stringliteral">"example"</span>, <span class="stringliteral">"wrong value %x"</span>, intval));
<a name="l00476"></a>00476 <span class="keywordflow">return</span> SNMP_ERR_WRONGVALUE;
<a name="l00477"></a>00477 }
<a name="l00478"></a>00478 <span class="keywordflow">break</span>;
<a name="l00479"></a>00479
<a name="l00480"></a>00480 <span class="keywordflow">case</span> RESERVE2:
<a name="l00481"></a>00481 <span class="comment">/*</span>
<a name="l00482"></a>00482 <span class="comment"> * This is conventially where any necesary</span>
<a name="l00483"></a>00483 <span class="comment"> * resources are allocated (e.g. calls to malloc)</span>
<a name="l00484"></a>00484 <span class="comment"> * Here, we are using static variables</span>
<a name="l00485"></a>00485 <span class="comment"> * so don't need to worry about this.</span>
<a name="l00486"></a>00486 <span class="comment"> */</span>
<a name="l00487"></a>00487 <span class="keywordflow">break</span>;
<a name="l00488"></a>00488
<a name="l00489"></a>00489 <span class="keywordflow">case</span> FREE:
<a name="l00490"></a>00490 <span class="comment">/*</span>
<a name="l00491"></a>00491 <span class="comment"> * This is where any of the above resources</span>
<a name="l00492"></a>00492 <span class="comment"> * are freed again (because one of the other</span>
<a name="l00493"></a>00493 <span class="comment"> * values being SET failed for some reason).</span>
<a name="l00494"></a>00494 <span class="comment"> * Again, since we are using static variables</span>
<a name="l00495"></a>00495 <span class="comment"> * we don't need to worry about this either.</span>
<a name="l00496"></a>00496 <span class="comment"> */</span>
<a name="l00497"></a>00497 <span class="keywordflow">break</span>;
<a name="l00498"></a>00498
<a name="l00499"></a>00499 <span class="keywordflow">case</span> ACTION:
<a name="l00500"></a>00500 <span class="comment">/*</span>
<a name="l00501"></a>00501 <span class="comment"> * Set the variable as requested.</span>
<a name="l00502"></a>00502 <span class="comment"> * Note that this may need to be reversed,</span>
<a name="l00503"></a>00503 <span class="comment"> * so save any information needed to do this.</span>
<a name="l00504"></a>00504 <span class="comment"> */</span>
<a name="l00505"></a>00505 old_intval = example_int;
<a name="l00506"></a>00506 example_int = intval;
<a name="l00507"></a>00507 <span class="keywordflow">break</span>;
<a name="l00508"></a>00508
<a name="l00509"></a>00509 <span class="keywordflow">case</span> UNDO:
<a name="l00510"></a>00510 <span class="comment">/*</span>
<a name="l00511"></a>00511 <span class="comment"> * Something failed, so re-set the</span>
<a name="l00512"></a>00512 <span class="comment"> * variable to its previous value</span>
<a name="l00513"></a>00513 <span class="comment"> * (and free any allocated resources).</span>
<a name="l00514"></a>00514 <span class="comment"> */</span>
<a name="l00515"></a>00515 example_int = old_intval;
<a name="l00516"></a>00516 <span class="keywordflow">break</span>;
<a name="l00517"></a>00517
<a name="l00518"></a>00518 <span class="keywordflow">case</span> COMMIT:
<a name="l00519"></a>00519 <span class="comment">/*</span>
<a name="l00520"></a>00520 <span class="comment"> * Everything worked, so we can discard any</span>
<a name="l00521"></a>00521 <span class="comment"> * saved information, and make the change</span>
<a name="l00522"></a>00522 <span class="comment"> * permanent (e.g. write to the config file).</span>
<a name="l00523"></a>00523 <span class="comment"> * We also free any allocated resources.</span>
<a name="l00524"></a>00524 <span class="comment"> *</span>
<a name="l00525"></a>00525 <span class="comment"> * In this case, there's nothing to do.</span>
<a name="l00526"></a>00526 <span class="comment"> */</span>
<a name="l00527"></a>00527 <span class="keywordflow">break</span>;
<a name="l00528"></a>00528
<a name="l00529"></a>00529 }
<a name="l00530"></a>00530 <span class="keywordflow">return</span> SNMP_ERR_NOERROR;
<a name="l00531"></a>00531 }
<a name="l00532"></a>00532
<a name="l00533"></a>00533 <span class="keywordtype">int</span>
<a name="l00534"></a>00534 write_exampletrap(<span class="keywordtype">int</span> action,
<a name="l00535"></a>00535 u_char * var_val,
<a name="l00536"></a>00536 u_char var_val_type,
<a name="l00537"></a>00537 <span class="keywordtype">size_t</span> var_val_len,
<a name="l00538"></a>00538 u_char * statP, oid * name, <span class="keywordtype">size_t</span> name_len)
<a name="l00539"></a>00539 {
<a name="l00540"></a>00540 <span class="keywordtype">long</span> intval;
<a name="l00541"></a>00541
<a name="l00542"></a>00542 DEBUGMSGTL((<span class="stringliteral">"example"</span>, <span class="stringliteral">"write_exampletrap entered: action=%d\n"</span>,
<a name="l00543"></a>00543 action));
<a name="l00544"></a>00544 <span class="keywordflow">switch</span> (action) {
<a name="l00545"></a>00545 <span class="keywordflow">case</span> RESERVE1:
<a name="l00546"></a>00546 <span class="comment">/*</span>
<a name="l00547"></a>00547 <span class="comment"> * The only acceptable value is the integer 1</span>
<a name="l00548"></a>00548 <span class="comment"> */</span>
<a name="l00549"></a>00549 <span class="keywordflow">if</span> (var_val_type != ASN_INTEGER) {
<a name="l00550"></a>00550 DEBUGMSGTL((<span class="stringliteral">"example"</span>, <span class="stringliteral">"%x not integer type"</span>, var_val_type));
<a name="l00551"></a>00551 <span class="keywordflow">return</span> SNMP_ERR_WRONGTYPE;
<a name="l00552"></a>00552 }
<a name="l00553"></a>00553 <span class="keywordflow">if</span> (var_val_len > <span class="keyword">sizeof</span>(<span class="keywordtype">long</span>)) {
<a name="l00554"></a>00554 DEBUGMSGTL((<span class="stringliteral">"example"</span>, <span class="stringliteral">"wrong length %x"</span>, var_val_len));
<a name="l00555"></a>00555 <span class="keywordflow">return</span> SNMP_ERR_WRONGLENGTH;
<a name="l00556"></a>00556 }
<a name="l00557"></a>00557
<a name="l00558"></a>00558 intval = *((<span class="keywordtype">long</span> *) var_val);
<a name="l00559"></a>00559 <span class="keywordflow">if</span> (intval != 1) {
<a name="l00560"></a>00560 DEBUGMSGTL((<span class="stringliteral">"example"</span>, <span class="stringliteral">"wrong value %x"</span>, intval));
<a name="l00561"></a>00561 <span class="keywordflow">return</span> SNMP_ERR_WRONGVALUE;
<a name="l00562"></a>00562 }
<a name="l00563"></a>00563 <span class="keywordflow">break</span>;
<a name="l00564"></a>00564
<a name="l00565"></a>00565 <span class="keywordflow">case</span> RESERVE2:
<a name="l00566"></a>00566 <span class="comment">/*</span>
<a name="l00567"></a>00567 <span class="comment"> * No resources are required.... </span>
<a name="l00568"></a>00568 <span class="comment"> */</span>
<a name="l00569"></a>00569 <span class="keywordflow">break</span>;
<a name="l00570"></a>00570
<a name="l00571"></a>00571 <span class="keywordflow">case</span> FREE:
<a name="l00572"></a>00572 <span class="comment">/*</span>
<a name="l00573"></a>00573 <span class="comment"> * ... so no resources need be freed </span>
<a name="l00574"></a>00574 <span class="comment"> */</span>
<a name="l00575"></a>00575 <span class="keywordflow">break</span>;
<a name="l00576"></a>00576
<a name="l00577"></a>00577 <span class="keywordflow">case</span> ACTION:
<a name="l00578"></a>00578 <span class="comment">/*</span>
<a name="l00579"></a>00579 <span class="comment"> * Having triggered the sending of a trap,</span>
<a name="l00580"></a>00580 <span class="comment"> * it would be impossible to revoke this,</span>
<a name="l00581"></a>00581 <span class="comment"> * so we can't actually invoke the action here.</span>
<a name="l00582"></a>00582 <span class="comment"> */</span>
<a name="l00583"></a>00583 <span class="keywordflow">break</span>;
<a name="l00584"></a>00584
<a name="l00585"></a>00585 <span class="keywordflow">case</span> UNDO:
<a name="l00586"></a>00586 <span class="comment">/*</span>
<a name="l00587"></a>00587 <span class="comment"> * We haven't done anything yet,</span>
<a name="l00588"></a>00588 <span class="comment"> * so there's nothing to undo </span>
<a name="l00589"></a>00589 <span class="comment"> */</span>
<a name="l00590"></a>00590 <span class="keywordflow">break</span>;
<a name="l00591"></a>00591
<a name="l00592"></a>00592 <span class="keywordflow">case</span> COMMIT:
<a name="l00593"></a>00593 <span class="comment">/*</span>
<a name="l00594"></a>00594 <span class="comment"> * Everything else worked, so it's now safe</span>
<a name="l00595"></a>00595 <span class="comment"> * to trigger the trap.</span>
<a name="l00596"></a>00596 <span class="comment"> * Note that this is *only* acceptable since</span>
<a name="l00597"></a>00597 <span class="comment"> * the trap sending routines are "failsafe".</span>
<a name="l00598"></a>00598 <span class="comment"> * (In fact, they can fail, but they return no</span>
<a name="l00599"></a>00599 <span class="comment"> * indication of this, which is the next best thing!)</span>
<a name="l00600"></a>00600 <span class="comment"> */</span>
<a name="l00601"></a>00601 DEBUGMSGTL((<span class="stringliteral">"example"</span>, <span class="stringliteral">"write_exampletrap sending the trap\n"</span>,
<a name="l00602"></a>00602 action));
<a name="l00603"></a>00603 <a class="code" href="group__agent__trap.html#ga86b1bcdaed1156316838acd02a276dc8" title="Sends an SNMPv1 trap (or the SNMPv2 equivalent) to the list of configured trap destinations (or "sink...">send_easy_trap</a>(SNMP_TRAP_ENTERPRISESPECIFIC, 99);
<a name="l00604"></a>00604 DEBUGMSGTL((<span class="stringliteral">"example"</span>, <span class="stringliteral">"write_exampletrap trap sent\n"</span>, action));
<a name="l00605"></a>00605 <span class="keywordflow">break</span>;
<a name="l00606"></a>00606
<a name="l00607"></a>00607 }
<a name="l00608"></a>00608 <span class="keywordflow">return</span> SNMP_ERR_NOERROR;
<a name="l00609"></a>00609 }
<a name="l00610"></a>00610
<a name="l00611"></a>00611 <span class="comment">/*</span>
<a name="l00612"></a>00612 <span class="comment"> * this documents how to send a SNMPv2 (and higher) trap via the</span>
<a name="l00613"></a>00613 <span class="comment"> * send_v2trap() API.</span>
<a name="l00614"></a>00614 <span class="comment"> * </span>
<a name="l00615"></a>00615 <span class="comment"> * Coding SNMP-v2 Trap:</span>
<a name="l00616"></a>00616 <span class="comment"> * </span>
<a name="l00617"></a>00617 <span class="comment"> * The SNMPv2-Trap PDU contains at least a pair of object names and</span>
<a name="l00618"></a>00618 <span class="comment"> * values: - sysUpTime.0 whose value is the time in hundredths of a</span>
<a name="l00619"></a>00619 <span class="comment"> * second since the netwok management portion of system was last</span>
<a name="l00620"></a>00620 <span class="comment"> * reinitialized. - snmpTrapOID.0 which is part of the trap group SNMPv2</span>
<a name="l00621"></a>00621 <span class="comment"> * MIB whose value is the object-id of the specific trap you have defined</span>
<a name="l00622"></a>00622 <span class="comment"> * in your own MIB. Other variables can be added to caracterize the</span>
<a name="l00623"></a>00623 <span class="comment"> * trap.</span>
<a name="l00624"></a>00624 <span class="comment"> * </span>
<a name="l00625"></a>00625 <span class="comment"> * The function send_v2trap adds automaticallys the two objects but the</span>
<a name="l00626"></a>00626 <span class="comment"> * value of snmpTrapOID.0 is 0.0 by default. If you want to add your trap</span>
<a name="l00627"></a>00627 <span class="comment"> * name, you have to reconstruct this object and to add your own</span>
<a name="l00628"></a>00628 <span class="comment"> * variable.</span>
<a name="l00629"></a>00629 <span class="comment"> * </span>
<a name="l00630"></a>00630 <span class="comment"> */</span>
<a name="l00631"></a>00631
<a name="l00632"></a>00632
<a name="l00633"></a>00633
<a name="l00634"></a>00634 <span class="keywordtype">int</span>
<a name="l00635"></a>00635 write_exampletrap2(<span class="keywordtype">int</span> action,
<a name="l00636"></a>00636 u_char * var_val,
<a name="l00637"></a>00637 u_char var_val_type,
<a name="l00638"></a>00638 <span class="keywordtype">size_t</span> var_val_len,
<a name="l00639"></a>00639 u_char * statP, oid * name, <span class="keywordtype">size_t</span> name_len)
<a name="l00640"></a>00640 {
<a name="l00641"></a>00641 <span class="keywordtype">long</span> intval;
<a name="l00642"></a>00642
<a name="l00643"></a>00643 <span class="comment">/*</span>
<a name="l00644"></a>00644 <span class="comment"> * these variales will be used when we send the trap </span>
<a name="l00645"></a>00645 <span class="comment"> */</span>
<a name="l00646"></a>00646 oid objid_snmptrap[] = { 1, 3, 6, 1, 6, 3, 1, 1, 4, 1, 0 }; <span class="comment">/* snmpTrapOID.0 */</span>
<a name="l00647"></a>00647 oid demo_trap[] = { 1, 3, 6, 1, 4, 1, 2021, 13, 990 }; <span class="comment">/*demo-trap */</span>
<a name="l00648"></a>00648 oid example_string_oid[] =
<a name="l00649"></a>00649 { 1, 3, 6, 1, 4, 1, 2021, 254, 1, 0 };
<a name="l00650"></a>00650 <span class="keyword">static</span> <a class="code" href="structvariable__list.html" title="The netsnmp variable list binding structure, it's typedef'd to netsnmp_variable_list.">netsnmp_variable_list</a> var_trap;
<a name="l00651"></a>00651 <span class="keyword">static</span> <a class="code" href="structvariable__list.html" title="The netsnmp variable list binding structure, it's typedef'd to netsnmp_variable_list.">netsnmp_variable_list</a> var_obj;
<a name="l00652"></a>00652
<a name="l00653"></a>00653 DEBUGMSGTL((<span class="stringliteral">"example"</span>, <span class="stringliteral">"write_exampletrap2 entered: action=%d\n"</span>,
<a name="l00654"></a>00654 action));
<a name="l00655"></a>00655 <span class="keywordflow">switch</span> (action) {
<a name="l00656"></a>00656 <span class="keywordflow">case</span> RESERVE1:
<a name="l00657"></a>00657 <span class="comment">/*</span>
<a name="l00658"></a>00658 <span class="comment"> * The only acceptable value is the integer 1</span>
<a name="l00659"></a>00659 <span class="comment"> */</span>
<a name="l00660"></a>00660 <span class="keywordflow">if</span> (var_val_type != ASN_INTEGER) {
<a name="l00661"></a>00661 DEBUGMSGTL((<span class="stringliteral">"example"</span>, <span class="stringliteral">"%x not integer type"</span>, var_val_type));
<a name="l00662"></a>00662 <span class="keywordflow">return</span> SNMP_ERR_WRONGTYPE;
<a name="l00663"></a>00663 }
<a name="l00664"></a>00664 <span class="keywordflow">if</span> (var_val_len > <span class="keyword">sizeof</span>(<span class="keywordtype">long</span>)) {
<a name="l00665"></a>00665 DEBUGMSGTL((<span class="stringliteral">"example"</span>, <span class="stringliteral">"wrong length %x"</span>, var_val_len));
<a name="l00666"></a>00666 <span class="keywordflow">return</span> SNMP_ERR_WRONGLENGTH;
<a name="l00667"></a>00667 }
<a name="l00668"></a>00668
<a name="l00669"></a>00669 intval = *((<span class="keywordtype">long</span> *) var_val);
<a name="l00670"></a>00670 <span class="keywordflow">if</span> (intval != 1) {
<a name="l00671"></a>00671 DEBUGMSGTL((<span class="stringliteral">"example"</span>, <span class="stringliteral">"wrong value %x"</span>, intval));
<a name="l00672"></a>00672 <span class="keywordflow">return</span> SNMP_ERR_WRONGVALUE;
<a name="l00673"></a>00673 }
<a name="l00674"></a>00674 <span class="keywordflow">break</span>;
<a name="l00675"></a>00675
<a name="l00676"></a>00676 <span class="keywordflow">case</span> RESERVE2:
<a name="l00677"></a>00677 <span class="comment">/*</span>
<a name="l00678"></a>00678 <span class="comment"> * No resources are required.... </span>
<a name="l00679"></a>00679 <span class="comment"> */</span>
<a name="l00680"></a>00680 <span class="keywordflow">break</span>;
<a name="l00681"></a>00681
<a name="l00682"></a>00682 <span class="keywordflow">case</span> FREE:
<a name="l00683"></a>00683 <span class="comment">/*</span>
<a name="l00684"></a>00684 <span class="comment"> * ... so no resources need be freed </span>
<a name="l00685"></a>00685 <span class="comment"> */</span>
<a name="l00686"></a>00686 <span class="keywordflow">break</span>;
<a name="l00687"></a>00687
<a name="l00688"></a>00688 <span class="keywordflow">case</span> ACTION:
<a name="l00689"></a>00689 <span class="comment">/*</span>
<a name="l00690"></a>00690 <span class="comment"> * Having triggered the sending of a trap,</span>
<a name="l00691"></a>00691 <span class="comment"> * it would be impossible to revoke this,</span>
<a name="l00692"></a>00692 <span class="comment"> * so we can't actually invoke the action here.</span>
<a name="l00693"></a>00693 <span class="comment"> */</span>
<a name="l00694"></a>00694 <span class="keywordflow">break</span>;
<a name="l00695"></a>00695
<a name="l00696"></a>00696 <span class="keywordflow">case</span> UNDO:
<a name="l00697"></a>00697 <span class="comment">/*</span>
<a name="l00698"></a>00698 <span class="comment"> * We haven't done anything yet,</span>
<a name="l00699"></a>00699 <span class="comment"> * so there's nothing to undo </span>
<a name="l00700"></a>00700 <span class="comment"> */</span>
<a name="l00701"></a>00701 <span class="keywordflow">break</span>;
<a name="l00702"></a>00702
<a name="l00703"></a>00703 <span class="keywordflow">case</span> COMMIT:
<a name="l00704"></a>00704 <span class="comment">/*</span>
<a name="l00705"></a>00705 <span class="comment"> * Everything else worked, so it's now safe</span>
<a name="l00706"></a>00706 <span class="comment"> * to trigger the trap.</span>
<a name="l00707"></a>00707 <span class="comment"> * Note that this is *only* acceptable since</span>
<a name="l00708"></a>00708 <span class="comment"> * the trap sending routines are "failsafe".</span>
<a name="l00709"></a>00709 <span class="comment"> * (In fact, they can fail, but they return no</span>
<a name="l00710"></a>00710 <span class="comment"> * indication of this, which is the next best thing!)</span>
<a name="l00711"></a>00711 <span class="comment"> */</span>
<a name="l00712"></a>00712
<a name="l00713"></a>00713 <span class="comment">/*</span>
<a name="l00714"></a>00714 <span class="comment"> * trap definition objects </span>
<a name="l00715"></a>00715 <span class="comment"> */</span>
<a name="l00716"></a>00716
<a name="l00717"></a>00717 var_trap.<a class="code" href="structvariable__list.html#a036af3c8c73da042622a58afa452d76e" title="NULL for last variable.">next_variable</a> = &var_obj; <span class="comment">/* next variable */</span>
<a name="l00718"></a>00718 var_trap.<a class="code" href="structvariable__list.html#a7b5bdda01921550d24ea53033ce76146" title="Object identifier of variable.">name</a> = objid_snmptrap; <span class="comment">/* snmpTrapOID.0 */</span>
<a name="l00719"></a>00719 var_trap.<a class="code" href="structvariable__list.html#a089e5b1a422bf8e693510ff5408a57a7" title="number of subid's in name">name_length</a> = <span class="keyword">sizeof</span>(objid_snmptrap) / <span class="keyword">sizeof</span>(oid); <span class="comment">/* number of sub-ids */</span>
<a name="l00720"></a>00720 var_trap.<a class="code" href="structvariable__list.html#a8bd719974b3554116631ea80dc88b6aa" title="ASN type of variable.">type</a> = ASN_OBJECT_ID;
<a name="l00721"></a>00721 var_trap.<a class="code" href="structvariable__list.html#a6ed7c00d712b83c174823b1cff6e9e29" title="value of variable">val</a>.objid = demo_trap; <span class="comment">/* demo-trap objid */</span>
<a name="l00722"></a>00722 var_trap.<a class="code" href="structvariable__list.html#a17aaa6b445178fc39aba69642247d3e9" title="the length of the value to be copied into buf">val_len</a> = <span class="keyword">sizeof</span>(demo_trap); <span class="comment">/* length in bytes (not number of subids!) */</span>
<a name="l00723"></a>00723
<a name="l00724"></a>00724
<a name="l00725"></a>00725 <span class="comment">/*</span>
<a name="l00726"></a>00726 <span class="comment"> * additional objects </span>
<a name="l00727"></a>00727 <span class="comment"> */</span>
<a name="l00728"></a>00728
<a name="l00729"></a>00729
<a name="l00730"></a>00730 var_obj.<a class="code" href="structvariable__list.html#a036af3c8c73da042622a58afa452d76e" title="NULL for last variable.">next_variable</a> = NULL; <span class="comment">/* No more variables after this one */</span>
<a name="l00731"></a>00731 var_obj.<a class="code" href="structvariable__list.html#a7b5bdda01921550d24ea53033ce76146" title="Object identifier of variable.">name</a> = example_string_oid;
<a name="l00732"></a>00732 var_obj.<a class="code" href="structvariable__list.html#a089e5b1a422bf8e693510ff5408a57a7" title="number of subid's in name">name_length</a> = <span class="keyword">sizeof</span>(example_string_oid) / <span class="keyword">sizeof</span>(oid); <span class="comment">/* number of sub-ids */</span>
<a name="l00733"></a>00733 var_obj.<a class="code" href="structvariable__list.html#a8bd719974b3554116631ea80dc88b6aa" title="ASN type of variable.">type</a> = ASN_OCTET_STR; <span class="comment">/* type of variable */</span>
<a name="l00734"></a>00734 var_obj.<a class="code" href="structvariable__list.html#a6ed7c00d712b83c174823b1cff6e9e29" title="value of variable">val</a>.string = example_str; <span class="comment">/* value */</span>
<a name="l00735"></a>00735 var_obj.<a class="code" href="structvariable__list.html#a17aaa6b445178fc39aba69642247d3e9" title="the length of the value to be copied into buf">val_len</a> = strlen(example_str);
<a name="l00736"></a>00736 DEBUGMSGTL((<span class="stringliteral">"example"</span>, <span class="stringliteral">"write_exampletrap2 sending the v2 trap\n"</span>,
<a name="l00737"></a>00737 action));
<a name="l00738"></a>00738 <a class="code" href="group__agent__trap.html#gac9fa0228d574f715b60cd93b87968a15" title="Uses the supplied list of variable bindings to form an SNMPv2 trap, which is sent to SNMPv2-capable s...">send_v2trap</a>(&var_trap);
<a name="l00739"></a>00739 DEBUGMSGTL((<span class="stringliteral">"example"</span>, <span class="stringliteral">"write_exampletrap2 v2 trap sent\n"</span>,
<a name="l00740"></a>00740 action));
<a name="l00741"></a>00741
<a name="l00742"></a>00742 <span class="keywordflow">break</span>;
<a name="l00743"></a>00743
<a name="l00744"></a>00744 }
<a name="l00745"></a>00745 <span class="keywordflow">return</span> SNMP_ERR_NOERROR;
<a name="l00746"></a>00746 }
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