8322 nl: misleading-indentation

[unleashed/tickless.git] / usr / src / cmd / fm / notify / snmp-notify / common / snmp-notify.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
 */

#include <sys/fm/protocol.h>
#include <fm/fmd_snmp.h>
#include <fm/fmd_msg.h>
#include <fm/libfmevent.h>
#include <net-snmp/net-snmp-config.h>
#include <net-snmp/net-snmp-includes.h>
#include <net-snmp/agent/net-snmp-agent-includes.h>
#include <errno.h>
#include <locale.h>
#include <netdb.h>
#include <signal.h>
#include <strings.h>
#include <stdlib.h>
#include <unistd.h>
#include <limits.h>
#include <alloca.h>
#include <priv_utils.h>
#include <zone.h>
#include "libfmnotify.h"

/*
 * Debug messages can be enabled by setting the debug property to true
 *
 * # svccfg -s svc:/system/fm/snmp-notify setprop config/debug=true
 */
#define SVCNAME         "system/fm/snmp-notify"

typedef struct ireport_trap {
        char *host;
        char *msgid;
        char *desc;
        long long tstamp;
        char *fmri;
        uint32_t from_state;
        uint32_t to_state;
        char *reason;
        boolean_t is_stn_event;
} ireport_trap_t;

static nd_hdl_t *nhdl;
static const char optstr[] = "dfR:";
static const char SNMP_SUPPCONF[] = "fmd-trapgen";
static char hostname[MAXHOSTNAMELEN + 1];

static int
usage(const char *pname)
{
        (void) fprintf(stderr, "Usage: %s [-df] [-R <altroot>]\n", pname);

        (void) fprintf(stderr,
            "\t-d  enable debug mode\n"
            "\t-f  stay in foreground\n"
            "\t-R  specify alternate root\n");

        return (1);
}

/*
 * If someone does an "svcadm refresh" on us, then this function gets called,
 * which rereads our service configuration.
 */
static void
get_svc_config()
{
        int s = 0;
        uint8_t val;

        s = nd_get_boolean_prop(nhdl, SVCNAME, "config", "debug", &val);
        nhdl->nh_debug = val;

        s += nd_get_astring_prop(nhdl, SVCNAME, "config", "rootdir",
            &(nhdl->nh_rootdir));

        if (s != 0)
                nd_error(nhdl, "Failed to read retrieve service "
                    "properties");
}

static void
nd_sighandler(int sig)
{
        if (sig == SIGHUP)
                get_svc_config();
        else
                nd_cleanup(nhdl);
}

static int
get_snmp_prefs(nd_hdl_t *nhdl, nvlist_t **pref_nvl, uint_t npref)
{
        boolean_t *a1, *a2;
        uint_t n;
        int r;

        /*
         * For SMF state transition events, pref_nvl contain two sets of
         * preferences, which will have to be merged.
         *
         * The "snmp" nvlist currently only supports a single boolean member,
         * "active" which will be set to true, if it is true in either set
         */
        if (npref == 2) {
                r = nvlist_lookup_boolean_array(pref_nvl[0], "active", &a1, &n);
                r += nvlist_lookup_boolean_array(pref_nvl[1], "active", &a2,
                    &n);
                if (r != 0) {
                        nd_debug(nhdl, "Malformed snmp notification "
                            "preferences");
                        nd_dump_nvlist(nhdl, pref_nvl[0]);
                        nd_dump_nvlist(nhdl, pref_nvl[1]);
                        return (-1);
                } else if (!a1[0] && !a2[0]) {
                        nd_debug(nhdl, "SNMP notification is disabled");
                        return (-1);
                }
        } else {
                if (nvlist_lookup_boolean_array(pref_nvl[0], "active",
                    &a1, &n)) {
                        nd_debug(nhdl, "Malformed snmp notification "
                            "preferences");
                        nd_dump_nvlist(nhdl, pref_nvl[0]);
                        return (-1);
                } else if (!a1[0]) {
                        nd_debug(nhdl, "SNMP notification is disabled");
                        return (-1);
                }
        }
        return (0);
}

static void
send_ireport_trap(ireport_trap_t *t)
{
        static const oid sunIreportTrap_oid[] =
            { SUNIREPORTTRAP_OID };
        const size_t sunIreportTrap_len =
            OID_LENGTH(sunIreportTrap_oid);

        static const oid sunIreportHostname_oid[] =
            { SUNIREPORTHOSTNAME_OID };
        static const oid sunIreportMsgid_oid[] =
            { SUNIREPORTMSGID_OID };
        static const oid sunIreportDescription_oid[] =
            { SUNIREPORTDESCRIPTION_OID };
        static const oid sunIreportTime_oid[] =
            { SUNIREPORTTIME_OID };

        static const oid sunIreportSmfFmri_oid[] =
            { SUNIREPORTSMFFMRI_OID };
        static const oid sunIreportSmfFromState_oid[] =
            { SUNIREPORTSMFFROMSTATE_OID };
        static const oid sunIreportSmfToState_oid[] =
            { SUNIREPORTSMFTOSTATE_OID };
        static const oid sunIreportSmfTransitionReason_oid[] =
            { SUNIREPORTTRANSITIONREASON_OID };
        const size_t
            sunIreport_base_len = OID_LENGTH(sunIreportHostname_oid);

        size_t var_len = sunIreport_base_len + 1;
        oid var_name[MAX_OID_LEN];

        netsnmp_variable_list *notification_vars = NULL;

        size_t dt_len;
        uchar_t dt[11], *tdt;
        time_t ts = t->tstamp;

        tdt = date_n_time(&ts, &dt_len);
        /*
         * We know date_n_time is broken, it returns a buffer from
         * its stack. So we copy before we step over it!
         */
        for (int i = 0; i < dt_len; ++i)
                dt[i] = tdt[i];

        if (var_len > MAX_OID_LEN) {
                nd_error(nhdl, "var_len %d > MAX_OID_LEN %d\n", var_len,
                    MAX_OID_LEN);
                return;
        }

        (void) memcpy(var_name, sunIreportHostname_oid, sunIreport_base_len *
            sizeof (oid));
        (void) snmp_varlist_add_variable(&notification_vars, var_name,
            sunIreport_base_len + 1, ASN_OCTET_STR, (uchar_t *)t->host,
            strlen(t->host));

        (void) memcpy(var_name, sunIreportMsgid_oid,
            sunIreport_base_len * sizeof (oid));
        (void) snmp_varlist_add_variable(&notification_vars, var_name,
            sunIreport_base_len + 1, ASN_OCTET_STR, (uchar_t *)t->msgid,
            strlen(t->msgid));

        (void) memcpy(var_name, sunIreportDescription_oid,
            sunIreport_base_len * sizeof (oid));
        (void) snmp_varlist_add_variable(&notification_vars, var_name,
            sunIreport_base_len + 1, ASN_OCTET_STR, (uchar_t *)t->desc,
            strlen(t->desc));

        (void) memcpy(var_name, sunIreportTime_oid, sunIreport_base_len *
            sizeof (oid));
        (void) snmp_varlist_add_variable(&notification_vars, var_name,
            sunIreport_base_len + 1, ASN_OCTET_STR, dt, dt_len);

        if (t->is_stn_event) {
                (void) memcpy(var_name, sunIreportSmfFmri_oid,
                    sunIreport_base_len * sizeof (oid));
                (void) snmp_varlist_add_variable(&notification_vars, var_name,
                    sunIreport_base_len + 1, ASN_OCTET_STR, (uchar_t *)t->fmri,
                    strlen(t->fmri));

                (void) memcpy(var_name, sunIreportSmfFromState_oid,
                    sunIreport_base_len * sizeof (oid));
                (void) snmp_varlist_add_variable(&notification_vars, var_name,
                    sunIreport_base_len + 1, ASN_INTEGER,
                    (uchar_t *)&t->from_state, sizeof (uint32_t));

                (void) memcpy(var_name, sunIreportSmfToState_oid,
                    sunIreport_base_len * sizeof (oid));
                (void) snmp_varlist_add_variable(&notification_vars, var_name,
                    sunIreport_base_len + 1, ASN_INTEGER,
                    (uchar_t *)&t->to_state, sizeof (uint32_t));

                (void) memcpy(var_name, sunIreportSmfTransitionReason_oid,
                    sunIreport_base_len * sizeof (oid));
                (void) snmp_varlist_add_variable(&notification_vars, var_name,
                    sunIreport_base_len + 1, ASN_OCTET_STR,
                    (uchar_t *)t->reason, strlen(t->reason));
        }

        /*
         * This function is capable of sending both v1 and v2/v3 traps.
         * Which is sent to a specific destination is determined by the
         * configuration file(s).
         */
        send_enterprise_trap_vars(SNMP_TRAP_ENTERPRISESPECIFIC,
            sunIreportTrap_oid[sunIreportTrap_len - 1],
            (oid *)sunIreportTrap_oid, sunIreportTrap_len - 2,
            notification_vars);
        nd_debug(nhdl, "Sent SNMP trap for %s", t->msgid);

        snmp_free_varbind(notification_vars);

}

/*ARGSUSED*/
static void
send_fm_trap(const char *uuid, const char *code, const char *url)
{
        static const oid sunFmProblemTrap_oid[] = { SUNFMPROBLEMTRAP_OID };
        const size_t sunFmProblemTrap_len = OID_LENGTH(sunFmProblemTrap_oid);

        static const oid sunFmProblemUUID_oid[] =
            { SUNFMPROBLEMTABLE_OID, 1, SUNFMPROBLEM_COL_UUID };
        static const oid sunFmProblemCode_oid[] =
            { SUNFMPROBLEMTABLE_OID, 1, SUNFMPROBLEM_COL_CODE };
        static const oid sunFmProblemURL_oid[] =
            { SUNFMPROBLEMTABLE_OID, 1, SUNFMPROBLEM_COL_URL };

        const size_t sunFmProblem_base_len = OID_LENGTH(sunFmProblemUUID_oid);

        size_t uuid_len = strlen(uuid);
        size_t var_len = sunFmProblem_base_len + 1 + uuid_len;
        oid var_name[MAX_OID_LEN];

        netsnmp_variable_list *notification_vars = NULL;

        /*
         * The format of our trap varbinds' oids is as follows:
         *
         * +-----------------------+---+--------+----------+------+
         * | SUNFMPROBLEMTABLE_OID | 1 | column | uuid_len | uuid |
         * +-----------------------+---+--------+----------+------+
         *                                       \---- index ----/
         *
         * A common mistake here is to send the trap with varbinds that
         * do not contain the index.  All the indices are the same, and
         * all the oids are the same length, so the only thing we need to
         * do for each varbind is set the table and column parts of the
         * variable name.
         */

        if (var_len > MAX_OID_LEN)
                return;

        var_name[sunFmProblem_base_len] = (oid)uuid_len;
        for (int i = 0; i < uuid_len; i++)
                var_name[i + sunFmProblem_base_len + 1] = (oid)uuid[i];

        /*
         * Ordinarily, we would need to add the OID of the trap itself
         * to the head of the variable list; this is required by SNMP v2.
         * However, send_enterprise_trap_vars does this for us as a part
         * of converting between v1 and v2 traps, so we skip directly to
         * the objects we're sending.
         */

        (void) memcpy(var_name, sunFmProblemUUID_oid,
            sunFmProblem_base_len * sizeof (oid));
        (void) snmp_varlist_add_variable(&notification_vars, var_name, var_len,
            ASN_OCTET_STR, (uchar_t *)uuid, strlen(uuid));
        (void) memcpy(var_name, sunFmProblemCode_oid,
            sunFmProblem_base_len * sizeof (oid));
        (void) snmp_varlist_add_variable(&notification_vars, var_name, var_len,
            ASN_OCTET_STR, (uchar_t *)code, strlen(code));
        (void) memcpy(var_name, sunFmProblemURL_oid,
            sunFmProblem_base_len * sizeof (oid));
        (void) snmp_varlist_add_variable(&notification_vars, var_name, var_len,
            ASN_OCTET_STR, (uchar_t *)url, strlen(url));

        /*
         * This function is capable of sending both v1 and v2/v3 traps.
         * Which is sent to a specific destination is determined by the
         * configuration file(s).
         */
        send_enterprise_trap_vars(SNMP_TRAP_ENTERPRISESPECIFIC,
            sunFmProblemTrap_oid[sunFmProblemTrap_len - 1],
            (oid *)sunFmProblemTrap_oid, sunFmProblemTrap_len - 2,
            notification_vars);
        nd_debug(nhdl, "Sent SNMP trap for %s", code);

        snmp_free_varbind(notification_vars);
}

/*
 * The SUN-IREPORT-MIB declares the following enum to represent SMF service
 * states.
 *
 * offline(0), online(1), degraded(2), disabled(3), maintenance(4),
 * uninitialized(5)
 *
 * This function converts a string representation of an SMF service state
 * to it's corresponding enum val.
 */
static int
state_to_val(char *statestr, uint32_t *stateval)
{
        if (strcmp(statestr, "offline") == 0)
                *stateval = 0;
        else if (strcmp(statestr, "online") == 0)
                *stateval = 1;
        else if (strcmp(statestr, "degraded") == 0)
                *stateval = 2;
        else if (strcmp(statestr, "disabled") == 0)
                *stateval = 3;
        else if (strcmp(statestr, "maintenance") == 0)
                *stateval = 4;
        else if (strcmp(statestr, "uninitialized") == 0)
                *stateval = 5;
        else
                return (-1);
        return (0);
}

/*ARGSUSED*/
static void
ireport_cb(fmev_t ev, const char *class, nvlist_t *nvl, void *arg)
{
        nvlist_t **pref_nvl = NULL;
        nd_ev_info_t *ev_info = NULL;
        ireport_trap_t swtrap;
        uint_t npref;
        int ret;

        nd_debug(nhdl, "Received event of class %s", class);

        ret = nd_get_notify_prefs(nhdl, "snmp", ev, &pref_nvl, &npref);
        if (ret == SCF_ERROR_NOT_FOUND) {
                /*
                 * No snmp notification preferences specified for this type of
                 * event, so we're done
                 */
                return;
        } else if (ret != 0) {
                nd_error(nhdl, "Failed to retrieve notification preferences "
                    "for this event");
                return;
        }

        if (get_snmp_prefs(nhdl, pref_nvl, npref) != 0)
                goto irpt_done;

        if (nd_get_event_info(nhdl, class, ev, &ev_info) != 0)
                goto irpt_done;

        swtrap.host = hostname;
        swtrap.msgid = ev_info->ei_diagcode;
        swtrap.desc = ev_info->ei_descr;
        swtrap.tstamp = (time_t)fmev_time_sec(ev);

        if (strncmp(class, "ireport.os.smf", 14) == 0) {
                swtrap.fmri = ev_info->ei_fmri;
                if (state_to_val(ev_info->ei_from_state, &swtrap.from_state)
                    < 0 ||
                    state_to_val(ev_info->ei_to_state, &swtrap.to_state) < 0) {
                        nd_error(nhdl, "Malformed event - invalid svc state");
                        nd_dump_nvlist(nhdl, ev_info->ei_payload);
                        goto irpt_done;
                }
                swtrap.reason = ev_info->ei_reason;
                swtrap.is_stn_event = B_TRUE;
        }
        send_ireport_trap(&swtrap);
irpt_done:
        if (ev_info)
                nd_free_event_info(ev_info);
        nd_free_nvlarray(pref_nvl, npref);
}

/*ARGSUSED*/
static void
list_cb(fmev_t ev, const char *class, nvlist_t *nvl, void *arg)
{
        char *uuid;
        uint8_t version;
        nd_ev_info_t *ev_info = NULL;
        nvlist_t **pref_nvl = NULL;
        uint_t npref;
        int ret;
        boolean_t domsg;

        nd_debug(nhdl, "Received event of class %s", class);

        ret = nd_get_notify_prefs(nhdl, "snmp", ev, &pref_nvl, &npref);
        if (ret == SCF_ERROR_NOT_FOUND) {
                /*
                 * No snmp notification preferences specified for this type of
                 * event, so we're done
                 */
                return;
        } else if (ret != 0) {
                nd_error(nhdl, "Failed to retrieve notification preferences "
                    "for this event");
                return;
        }

        if (get_snmp_prefs(nhdl, pref_nvl, npref) != 0)
                goto listcb_done;

        if (nd_get_event_info(nhdl, class, ev, &ev_info) != 0)
                goto listcb_done;

        /*
         * If the message payload member is set to 0, then it's an event we
         * typically suppress messaging on, so we won't send a trap for it.
         */
        if (nvlist_lookup_boolean_value(ev_info->ei_payload, FM_SUSPECT_MESSAGE,
            &domsg) == 0 && !domsg) {
                nd_debug(nhdl, "Messaging suppressed for this event");
                goto listcb_done;
        }

        if (nvlist_lookup_uint8(ev_info->ei_payload, FM_VERSION, &version)
            != 0 || version > FM_SUSPECT_VERSION) {
                nd_error(nhdl, "invalid event version: %u", version);
                goto listcb_done;
        }

        (void) nvlist_lookup_string(ev_info->ei_payload, FM_SUSPECT_UUID,
            &uuid);

        if (strcmp(ev_info->ei_url, ND_UNKNOWN) != 0)
                send_fm_trap(uuid, ev_info->ei_diagcode, ev_info->ei_url);
        else
                nd_error(nhdl, "failed to format url for %s", uuid);
listcb_done:
        nd_free_nvlarray(pref_nvl, npref);
        if (ev_info)
                nd_free_event_info(ev_info);
}

static int
init_sma(void)
{
        int err;

        /*
         * The only place we could possibly log is syslog, but the
         * full agent doesn't normally log there.  It would be confusing
         * if this agent did so; therefore we disable logging entirely.
         */
        snmp_disable_log();

        /*
         * Net-SNMP has a provision for reading an arbitrary number of
         * configuration files.  A configuration file is read if it has
         * had any handlers registered for it, or if it's the value in
         * of NETSNMP_DS_LIB_APPTYPE.  Our objective here is to read
         * both snmpd.conf and fmd-trapgen.conf.
         */
        if ((err = netsnmp_ds_set_boolean(NETSNMP_DS_APPLICATION_ID,
            NETSNMP_DS_AGENT_ROLE, 0 /* MASTER_AGENT */)) != SNMPERR_SUCCESS)
                return (err);

        init_agent_read_config("snmpd");
        if ((err = netsnmp_ds_set_string(NETSNMP_DS_LIBRARY_ID,
            NETSNMP_DS_LIB_APPTYPE, SNMP_SUPPCONF)) != SNMPERR_SUCCESS)
                return (err);
        if (register_app_config_handler("trapsink", snmpd_parse_config_trapsink,
            snmpd_free_trapsinks, "host [community] [port]") == NULL)
                return (SNMPERR_MALLOC);
        if (register_app_config_handler("trap2sink",
            snmpd_parse_config_trap2sink, NULL, "host [community] [port]") ==
            NULL)
                return (SNMPERR_MALLOC);
        if (register_app_config_handler("trapsess", snmpd_parse_config_trapsess,
            NULL, "[snmpcmdargs] host") == NULL)
                return (SNMPERR_MALLOC);

        init_traps();
        init_snmp(SNMP_SUPPCONF);

        return (SNMPERR_SUCCESS);
}

int
main(int argc, char *argv[])
{
        struct rlimit rlim;
        struct sigaction act;
        sigset_t set;
        char c;
        boolean_t run_fg = B_FALSE;

        if ((nhdl = malloc(sizeof (nd_hdl_t))) == NULL) {
                (void) fprintf(stderr, "Failed to allocate space for notifyd "
                    "handle (%s)", strerror(errno));
                return (1);
        }
        bzero(nhdl, sizeof (nd_hdl_t));
        nhdl->nh_keep_running = B_TRUE;
        nhdl->nh_log_fd = stderr;
        nhdl->nh_pname = argv[0];

        get_svc_config();

        /*
         * In the case where we get started outside of SMF, args passed on the
         * command line override SMF property setting
         */
        while (optind < argc) {
                while ((c = getopt(argc, argv, optstr)) != -1) {
                        switch (c) {
                        case 'd':
                                nhdl->nh_debug = B_TRUE;
                                break;
                        case 'f':
                                run_fg = B_TRUE;
                                break;
                        case 'R':
                                nhdl->nh_rootdir = strdup(optarg);
                                break;
                        default:
                                free(nhdl);
                                return (usage(nhdl->nh_pname));
                        }
                }
        }

        /*
         * Set up a signal handler for SIGTERM (and SIGINT if we'll
         * be running in the foreground) to ensure sure we get a chance to exit
         * in an orderly fashion.  We also catch SIGHUP, which will be sent to
         * us by SMF if the service is refreshed.
         */
        (void) sigfillset(&set);
        (void) sigfillset(&act.sa_mask);
        act.sa_handler = nd_sighandler;
        act.sa_flags = 0;

        (void) sigaction(SIGTERM, &act, NULL);
        (void) sigdelset(&set, SIGTERM);
        (void) sigaction(SIGHUP, &act, NULL);
        (void) sigdelset(&set, SIGHUP);

        if (run_fg) {
                (void) sigaction(SIGINT, &act, NULL);
                (void) sigdelset(&set, SIGINT);
        } else
                nd_daemonize(nhdl);

        rlim.rlim_cur = RLIM_INFINITY;
        rlim.rlim_max = RLIM_INFINITY;
        (void) setrlimit(RLIMIT_CORE, &rlim);

        /*
         * We need to be root initialize our libfmevent handle (because that
         * involves reading/writing to /dev/sysevent), so we do this before
         * calling __init_daemon_priv.
         */
        nhdl->nh_evhdl = fmev_shdl_init(LIBFMEVENT_VERSION_2, NULL, NULL, NULL);
        if (nhdl->nh_evhdl == NULL) {
                (void) sleep(5);
                nd_abort(nhdl, "failed to initialize libfmevent: %s",
                    fmev_strerror(fmev_errno));
        }

        /*
         * If we're in the global zone, reset all of our privilege sets to
         * the minimum set of required privileges.   We also change our
         * uid/gid to noaccess/noaccess
         *
         * __init_daemon_priv will also set the process core path for us
         *
         */
        if (getzoneid() == GLOBAL_ZONEID)
                if (__init_daemon_priv(
                    PU_RESETGROUPS | PU_LIMITPRIVS | PU_INHERITPRIVS,
                    60002, 60002, PRIV_FILE_DAC_READ, NULL) != 0)
                        nd_abort(nhdl, "additional privileges required to run");

        nhdl->nh_msghdl = fmd_msg_init(nhdl->nh_rootdir, FMD_MSG_VERSION);
        if (nhdl->nh_msghdl == NULL)
                nd_abort(nhdl, "failed to initialize libfmd_msg");

        if (init_sma() != SNMPERR_SUCCESS)
                nd_abort(nhdl, "SNMP initialization failed");

        (void) gethostname(hostname, MAXHOSTNAMELEN + 1);
        /*
         * Set up our event subscriptions.  We subscribe to everything and then
         * consult libscf when we receive an event to determine what (if any)
         * notification to send.
         */
        nd_debug(nhdl, "Subscribing to ireport.os.smf.* events");
        if (fmev_shdl_subscribe(nhdl->nh_evhdl, "ireport.os.smf.*",
            ireport_cb, NULL) != FMEV_SUCCESS) {
                nd_abort(nhdl, "fmev_shdl_subscribe failed: %s",
                    fmev_strerror(fmev_errno));
        }

        nd_debug(nhdl, "Subscribing to list.* events");
        if (fmev_shdl_subscribe(nhdl->nh_evhdl, "list.*", list_cb,
            NULL) != FMEV_SUCCESS) {
                nd_abort(nhdl, "fmev_shdl_subscribe failed: %s",
                    fmev_strerror(fmev_errno));
        }

        /*
         * We run until someone kills us
         */
        while (nhdl->nh_keep_running)
                (void) sigsuspend(&set);

        /*
         * snmp_shutdown, which we would normally use here, calls free_slots,
         * a callback that is supposed to tear down the pkcs11 state; however,
         * it abuses C_Finalize, causing fmd to drop core on shutdown.  Avoid
         * this by shutting down the library piecemeal.
         */
        snmp_store(SNMP_SUPPCONF);
        snmp_alarm_unregister_all();
        (void) snmp_close_sessions();
        shutdown_mib();
        unregister_all_config_handlers();
        netsnmp_ds_shutdown();

        free(nhdl->nh_rootdir);
        free(nhdl);

        return (0);
}