mtetriggerconf.c

开发snmp的开发包有两个开放的SNMP开发库

/*
 * DisMan Event MIB:
 *     Implementation of the trigger table configure handling
 */

#include <net-snmp/net-snmp-config.h>
#include <net-snmp/net-snmp-includes.h>
#include <net-snmp/agent/net-snmp-agent-includes.h>
#include <net-snmp/agent/agent_callbacks.h>
#include "utilities/iquery.h"
#include "disman/event/mteObjects.h"
#include "disman/event/mteTrigger.h"
#include "disman/event/mteTriggerConf.h"

#include <ctype.h>


/** Initializes the mteTriggerConf module */
void
init_mteTriggerConf(void)
{
    init_trigger_table_data();

    /*
     * Register config handler for user-level (fixed) triggers ...
     */
    snmpd_register_config_handler("monitor",
                                   parse_mteMonitor,  NULL,
                                  "triggername [-I] [-i OID | -o OID]* [-e event] expression ");
    snmpd_register_config_handler("defaultMonitors",
                                   parse_default_mteMonitors, NULL, "yes|no");
    snmpd_register_config_handler("linkUpDownNotifications",
                                   parse_linkUpDown_traps,    NULL, "yes|no");

    /*
     * ... for persistent storage of various event table entries ...
     */
    snmpd_register_config_handler("_mteTTable",
                                   parse_mteTTable,   NULL, NULL);
    snmpd_register_config_handler("_mteTDTable",
                                   parse_mteTDTable,  NULL, NULL);
    snmpd_register_config_handler("_mteTExTable",
                                   parse_mteTExTable, NULL, NULL);
    snmpd_register_config_handler("_mteTBlTable",
                                   parse_mteTBlTable, NULL, NULL);
    snmpd_register_config_handler("_mteTThTable",
                                   parse_mteTThTable, NULL, NULL);

    /*
     * ... and backwards compatability with the previous implementation.
     */
    snmpd_register_config_handler("mteTriggerTable",
                                   parse_mteTriggerTable, NULL, NULL);

    /*
     * Register to save (non-fixed) entries when the agent shuts down
     */
    snmp_register_callback(SNMP_CALLBACK_LIBRARY, SNMP_CALLBACK_STORE_DATA,
                           store_mteTTable, NULL);
    snmp_register_callback(SNMP_CALLBACK_APPLICATION,
                           SNMPD_CALLBACK_PRE_UPDATE_CONFIG,
                           clear_mteTTable, NULL);
}

/* ==============================
 *
 *       utility routines
 *
 * ============================== */

    /*
     * Find or create the specified trigger entry
     */
struct mteTrigger *
_find_mteTrigger_entry( char *owner, char *tname )
{
    netsnmp_variable_list owner_var, tname_var;
    netsnmp_tdata_row *row;

        /*
         * If there's already an existing entry,
         *   then use that...
         */
    memset(&owner_var, 0, sizeof(netsnmp_variable_list));
    memset(&tname_var, 0, sizeof(netsnmp_variable_list));
    snmp_set_var_typed_value(&owner_var, ASN_OCTET_STR, owner, strlen(owner));
    snmp_set_var_typed_value(&tname_var, ASN_PRIV_IMPLIED_OCTET_STR,
                                                        tname, strlen(tname));
    owner_var.next_variable = &tname_var;
    row = netsnmp_tdata_row_get_byidx( trigger_table_data, &owner_var );
        /*
         * ... otherwise, create a new one
         */
    if (!row)
        row = mteTrigger_createEntry( owner, tname, 0 );
    if (!row)
        return NULL;
    
    /* return (struct mteTrigger *)netsnmp_tdata_row_entry( row ); */
    return (struct mteTrigger *)row->data;
}

struct mteTrigger *
_find_typed_mteTrigger_entry( char *owner, char *tname, int type )
{
    struct mteTrigger *entry = _find_mteTrigger_entry( owner, tname );
    if (!entry)
        return NULL;

    /*
     *  If this is an existing (i.e. valid) entry of the
     *    same type, then throw an error and discard it.
     *  But allow combined Existence/Boolean/Threshold trigger.
     */
    if ( entry &&
        (entry->flags & MTE_TRIGGER_FLAG_VALID) &&
        (entry->mteTriggerTest & type )) {
        config_perror("duplicate trigger name");
        return NULL;
    }
    return entry;
}


/* ================================================
 *
 *  Handlers for user-configured (static) triggers
 *
 * ================================================ */

int
_mteTrigger_callback_enable( int   majorID,    int   minorID,
                             void *serverargs, void *clientarg)
{
    struct mteTrigger *entry = (struct mteTrigger *)clientarg;
    mteTrigger_enable( entry );

    return 0;
}


void
parse_mteMonitor(const char *token, char *line)
{
    char   buf[  SPRINT_MAX_LEN];
    char   tname[MTE_STR1_LEN+1];
    char  *cp;
    long   test = 0;

    char   ename[MTE_STR1_LEN+1];
    long   flags = MTE_TRIGGER_FLAG_ENABLED |
                   MTE_TRIGGER_FLAG_ACTIVE  |
                   MTE_TRIGGER_FLAG_FIXED   |
                   MTE_TRIGGER_FLAG_VWILD   |
                   MTE_TRIGGER_FLAG_SYSUPT  |
                   MTE_TRIGGER_FLAG_VALID;
    long   idx     = 0;
    long   startup = 1;    /* ??? or 0 */
    long   repeat  = 600;
    netsnmp_session *sess = NULL;

    int    seen_name = 0;
    char   oid_name_buf[SPRINT_MAX_LEN];
    oid    name_buf[MAX_OID_LEN];
    size_t name_buf_len;
    long   op    = 0;
    long   value = 0;

    struct mteObject  *object;
    struct mteTrigger *entry;

    DEBUGMSGTL(("disman:event:conf", "Parsing disman monitor config (%s)\n", line));

    /*
     * Before parsing the configuration fully, first
     * skim through the config line in order to:
     *   a) locate the name for the trigger, and
     *   b) identify the type of trigger test
     *
     * This information will be used both for creating the trigger
     *  entry, and registering any additional payload objects.
     */
    memset( buf,   0, sizeof(buf));
    memset( tname, 0, sizeof(tname));
    memset( ename, 0, sizeof(ename));
    for (cp = copy_nword(line, buf, SPRINT_MAX_LEN);
         ;
         cp = copy_nword(cp,   buf, SPRINT_MAX_LEN)) {

        if ( buf[0] == '-' ) {
            switch (buf[1]) {
            case 't':
                /* No longer necessary */
                break;
            case 'd':
            case 'e':
            case 'o':
            case 'r':
            case 'u':
                /* skip option parameter */
                cp = skip_token( cp );
                break;
            case 'D':
            case 'I':
            case 's':
            case 'S':
                /* flag options */
                break;
            case 'i':
                /*
                 * '-i' can act as a flag or take a parameter.
                 *      Handle either case.
                 */
                if (cp && *cp != '-')
                    cp = skip_token( cp );
                break;
            case '0':
            case '1':
            case '2':
            case '3':
            case '4':
            case '5':
            case '6':
            case '7':
            case '8':
            case '9':
                /* accept negative values */
            case '\0':
                /* and '-' placeholder value */
                break;
            default:
                config_perror("unrecognised option");
                return;
            }
        } else {
            /*
             * Save the first non-option parameter as the trigger name.
             *
             * This name will also be used to register entries in the
             *    mteObjectsTable, so insert a distinguishing prefix.
             * This will ensure combined trigger entries don't clash with
             *    each other, or with a similarly-named notification event.
             */
            if ( !tname[0] ) {
                tname[0] = '_';
                tname[1] = '_';   /* Placeholder */
                memcpy( tname+2, buf, MTE_STR1_LEN-2 );
            } else {
                /*
                 * This marks the beginning of the monitor expression,
                 *   so we don't need to scan any further
                 */
                break;
            }
        }
        if (!cp)
            break;
    }

    /*
     * Now let's examine the expression to determine the type of
     *   monitor being configured.  There are four possible forms:
     *     != OID  (or ! OID)     (existence test)
     *        OID                 (existence test)
     *        OID  op  VALUE      (boolean   test)
     *        OID  MIN MAX        (threshold test)
     */
    if ( *buf == '!' ) {
       /*
        * If the expression starts with '!=' or '!', then
        *  it must be the first style of existence test.
        */
       test = MTE_TRIGGER_EXISTENCE;
    } else {
       /*
        * Otherwise the first token is the OID to be monitored.
        *   Skip it and look at the next token (if any).
        */
        cp = copy_nword(cp,   buf, SPRINT_MAX_LEN);
        if (cp) {
            /*
             * If this is a numeric value, then it'll be the MIN
             *   field of a threshold test (the fourth form)
             * Otherwise it'll be the operation field of a
             *   boolean test (the third form)
             */
            if ( isdigit(buf[0]) || buf[0] == '-' )
                test = MTE_TRIGGER_THRESHOLD;
            else
                test = MTE_TRIGGER_BOOLEAN;
        } else {
            /*
             * If there isn't a "next token", then this
             *   must be the second style of existence test.
             */
            test = MTE_TRIGGER_EXISTENCE;
        }
    }

    /*
     * Use the type of trigger test to update the trigger name buffer
     */
    switch (test) {
    case MTE_TRIGGER_BOOLEAN:
        tname[1] = 'B'; break;
    case MTE_TRIGGER_THRESHOLD:
        tname[1] = 'T'; break;
    case MTE_TRIGGER_EXISTENCE:
        tname[1] = 'X'; break;
    }
    
 
    
    /*
     * Now start parsing again at the beginning of the directive,
     *   extracting the various options...
     */
    for (cp = copy_nword(line, buf, SPRINT_MAX_LEN);
         ;
         cp = copy_nword(cp,   buf, SPRINT_MAX_LEN)) {

        if (buf[0] == '-' ) {
            switch (buf[1]) {
            case 'D':   /* delta sample value */
                flags |= MTE_TRIGGER_FLAG_DELTA;
                break;

            case 'd':   /* discontinuity OID (implies delta sample) */
                flags |= MTE_TRIGGER_FLAG_DELTA;
                if (buf[2] != 'i')
                    flags |= MTE_TRIGGER_FLAG_DWILD;
                memset( oid_name_buf, 0, sizeof(oid_name_buf));
                memset(     name_buf, 0, sizeof(    name_buf));
                name_buf_len = MAX_OID_LEN;
                cp = copy_nword(cp, oid_name_buf, MTE_STR1_LEN);
                if (!snmp_parse_oid(oid_name_buf, name_buf, &name_buf_len)) {
                    snmp_log(LOG_ERR, "discontinuity OID: %s\n", oid_name_buf);
                    config_perror("unknown discontinuity OID");
                    mteObjects_removeEntries( "snmpd.conf", tname );
                    return;
                }
                if ( snmp_oid_compare( name_buf, name_buf_len,
                                       _sysUpTime_instance,
                                       _sysUpTime_inst_len) != 0 )
                    flags &= ~MTE_TRIGGER_FLAG_SYSUPT;
                break;
    
            case 'e':   /*  event */
                cp     = copy_nword(cp, ename, MTE_STR1_LEN);
                break;
    
            case 'I':   /* value instance */
                flags &= ~MTE_TRIGGER_FLAG_VWILD;
                break;
    
                        /*
                         * "instance" flag:
                         *     either non-wildcarded mteTriggerValueID
                         *       (backwards compatability - see '-I')
                         *     or exact payload OID
                         *       (c.f. notificationEvent config)
                         */
            case 'i':
                if ( *cp == '-' ) {
                    /* Backwards compatibility - now '-I' */
                    flags &= ~MTE_TRIGGER_FLAG_VWILD;
                    continue;
                }
                idx++;
                cp     = copy_nword(cp, buf, SPRINT_MAX_LEN);