Attachment 580431 Details for Bug 803585 – subagent for reproducer

subagent for reproducer

subagent.c (text/plain), 9.26 KB, created by Jan Safranek on 2012-04-26 10:56:48 UTC

(hide)

Description:

Filename:

MIME Type:

Creator: Jan Safranek

Created: 2012-04-26 10:56:48 UTC

Size: 9.26 KB

patch

obsolete

>/*
> *  Template MIB group implementation - example.c
> *
> */
>
>/*
> * include important headers 
> */
>#include <net-snmp/net-snmp-config.h>
>#if HAVE_STDLIB_H
>#include <stdlib.h>
>#endif
>#if HAVE_STRING_H
>#include <string.h>
>#else
>#include <strings.h>
>#endif
>
>/*
> * needed by util_funcs.h 
> */
>#if TIME_WITH_SYS_TIME
># ifdef WIN32
>#  include <sys/timeb.h>
># else
>#  include <sys/time.h>
># endif
># include <time.h>
>#else
># if HAVE_SYS_TIME_H
>#  include <sys/time.h>
># else
>#  include <time.h>
># endif
>#endif
>
>#if HAVE_WINSOCK_H
>#include <winsock.h>
>#endif
>#if HAVE_NETINET_IN_H
>#include <netinet/in.h>
>#endif
>
>#include <net-snmp/net-snmp-includes.h>
>#include <net-snmp/agent/net-snmp-agent-includes.h>
>
>/*
> * include our .h file 
> */
>#include "subagent.h"
>
>#include <limits.h>
>
>#define EXAMPLESTRING           1
>#define EXAMPLEINT1             2
>#define EXAMPLEINT2             3
>#define EXAMPLEINT3             4
>#define EXAMPLEINT4             5
>   /*
>    *  Certain objects can be set via configuration file directives.
>    *  These variables hold the values for such objects, as they need to
>    *   be accessible to both the config handlers, and the callback routine.
>    */
>#define EXAMPLE_STR_LEN	300
>#define EXAMPLE_STR_DEFAULT	"life the universe and everything"
>
>        /*********************
>	 *
>	 *  Initialisation & common implementation functions
>	 *
>	 *********************/
>
>    /*
>     * This array structure defines a representation of the
>     *  MIB being implemented.
>     *
>     * The type of the array is 'struct variableN', where N is
>     *  large enough to contain the longest OID sub-component
>     *  being loaded.  This will normally be the maximum value
>     *  of the fifth field in each line.  In this case, the second
>     *  and third entries are both of size 2, so we're using
>     *  'struct variable2'
>     *
>     * The supported values for N are listed in <agent/var_struct.h>
>     *  If the value you need is not listed there, simply use the
>     *  next largest that is.
>     *
>     * The format of each line is as follows
>     *  (using the first entry as an example):
>     *      1: EXAMPLESTRING:
>     *          The magic number defined in the example header file.
>     *          This is passed to the callback routine and is used
>     *            to determine which object is being queried.
>     *      2: ASN_OCTET_STR:
>     *          The type of the object.
>     *          Valid types are listed in <snmp_impl.h>
>     *      3: RONLY (or RWRITE):
>     *          Whether this object can be SET or not.
>     *      4: var_example:
>     *          The callback routine, used when the object is queried.
>     *          This will usually be the same for all objects in a module
>     *            and is typically defined later in this file.
>     *      5: 1:
>     *          The length of the OID sub-component (the next field)
>     *      6: {1}:
>     *          The OID sub-components of this entry.
>     *          In other words, the bits of the full OID that differ
>     *            between the various entries of this array.
>     *          This value is appended to the common prefix (defined later)
>     *            to obtain the full OID of each entry.
>     */
>struct variable2 example_variables[] = {
>    {EXAMPLESTRING, ASN_OCTET_STR, RONLY, var_example, 1, {1}},
>    {EXAMPLEINT1, ASN_COUNTER64, RONLY, var_example, 1, {2}},
>    {EXAMPLEINT2, ASN_COUNTER64, RONLY, var_example, 1, {3}},
>    {EXAMPLEINT3, ASN_COUNTER64, RONLY, var_example, 1, {4}},
>    {EXAMPLEINT4, ASN_COUNTER64, RONLY, var_example, 1, {5}},
>    
>};
>
>    /*
>     * This array defines the OID of the top of the mib tree that we're
>     *  registering underneath.
>     * Note that this needs to be the correct size for the OID being 
>     *  registered, so that the length of the OID can be calculated.
>     *  The format given here is the simplest way to achieve this.
>     */
>oid             example_variables_oid[] = { 1, 3, 6, 1, 4, 1, 2021, 1, 1 };
>
>
>
>    /*
>     * This function is called at the time the agent starts up
>     *  to do any initializations that might be required.
>     *
>     * In theory it is optional and can be omitted if no
>     *  initialization is needed.  In practise, every module
>     *  will need to register itself (or the objects being
>     *  implemented will not appear in the MIB tree), and this
>     *  registration is typically done here.
>     *
>     * If this function is added or removed, you must re-run
>     *  the configure script, to detect this change.
>     */
>void
>init_subagent(void)
>{
>    /*
>     * Register ourselves with the agent to handle our mib tree.
>     * The arguments are:
>     *    descr:   A short description of the mib group being loaded.
>     *    var:     The variable structure to load.
>     *                  (the name of the variable structure defined above)
>     *    vartype: The type of this variable structure
>     *    theoid:  The OID pointer this MIB is being registered underneath.
>     */
>     register_mib_priority("subagent", (struct variable *) example_variables, sizeof(struct variable2), sizeof(example_variables)/sizeof(struct variable2), example_variables_oid,
>        sizeof(example_variables_oid)/sizeof(oid), 120);
>//    REGISTER_MIB("example", example_variables, variable2, example_variables_oid);
>}
>
>        /*********************
>	 *
>	 *  System specific implementation functions
>	 *
>	 *********************/
>
>    /*
>     * Define the callback function used in the example_variables structure.
>     * This is called whenever an incoming request refers to an object
>     *  within this sub-tree.
>     *
>     * Four of the parameters are used to pass information in.
>     * These are:
>     *    vp      The entry from the 'example_variables' array for the
>     *             object being queried.
>     *    name    The OID from the request.
>     *    length  The length of this OID.
>     *    exact   A flag to indicate whether this is an 'exact' request
>     *             (GET/SET) or an 'inexact' one (GETNEXT/GETBULK).
>     *
>     * Four of the parameters are used to pass information back out.
>     * These are:
>     *    name     The OID being returned.
>     *    length   The length of this OID.
>     *    var_len  The length of the answer being returned.
>     *    write_method   A pointer to the SET function for this object.
>     *
>     * Note that name & length serve a dual purpose in both roles.
>     */
>
>u_char         *
>var_example(struct variable *vp,
>            oid * name,
>            size_t * length,
>            int exact, size_t * var_len, WriteMethod ** write_method)
>{
>    /*
>     *  The result returned from this function needs to be a pointer to
>     *    static data (so that it can be accessed from outside).
>     *  Define suitable variables for any type of data we may return.
>     */
>    static char string[200];
>    static int i;
>    static long l;
>    static U64 counter;
>
>    /*
>     * Before returning an answer, we need to check that the request
>     *  refers to a valid instance of this object.  The utility routine
>     *  'header_generic' can be used to do this for scalar objects.
>     *
>     * This routine 'header_simple_table' does the same thing for "simple"
>     *  tables. (See the AGENT.txt file for the definition of a simple table).
>     *
>     * Both these utility routines also set up default values for the
>     *  return arguments (assuming the check succeeded).
>     * The name and length are set suitably for the current object,
>     *  var_len assumes that the result is an integer of some form,
>     *  and write_method assumes that the object cannot be set.
>     *
>     * If these assumptions are correct, this callback routine simply
>     * needs to return a pointer to the appropriate value (using 'long_ret').
>     * Otherwise, 'var_len' and/or 'write_method' should be set suitably.
>     */
>    DEBUGMSGTL(("example", "var_example entered\n"));
>    if (header_generic(vp, name, length, exact, var_len, write_method) ==
>        MATCH_FAILED)
>        return NULL;
>
>    switch (vp->magic) {
>    case EXAMPLESTRING:
>        sprintf(string, "Hello world, i=%d, l=%d", sizeof(i), sizeof(l));
>        *var_len = strlen(string);
>        return (u_char *) string;
>
>    case EXAMPLEINT1:
>        counter.low=0;
>        counter.high=1;
>        *var_len = sizeof(U64);
>        return (u_char *) & counter;
>    case EXAMPLEINT2:
>        counter.low=1;
>        counter.high=1;
>        *var_len = sizeof(U64);
>        return (u_char *) & counter;
>    case EXAMPLEINT3:
>        counter.low=2;
>        counter.high=1;
>        *var_len = sizeof(U64);
>        return (u_char *) & counter;
>    case EXAMPLEINT4:
>        counter.low=3;
>        counter.high=1;
>        *var_len = sizeof(U64);
>        return (u_char *) & counter;
>
>    default:
>        /*
>         *  This will only be triggered if there's a problem with
>         *   the coding of the module.  SNMP requests that reference
>         *   a non-existant OID will be directed elsewhere.
>         *  If this branch is reached, log an error, so that
>         *   the problem can be investigated.
>         */
>        printf("Intentionally exiting subagent to test AgentX\n");
>        exit(0);
>
>        DEBUGMSGTL(("snmpd", "unknown sub-id %d in examples/var_example\n",
>                    vp->magic));
>    }
>    /*
>     * If we fall through to here, fail by returning NULL.
>     * This is essentially a continuation of the 'default' case above.
>     */
>    return NULL;
>}
>

Actions: View

Attachments on bug 803585: 580431