Beispiel #1
0
/*******************************************************************-o-******
 * receive
 *
 * Parameters:
 *      
 * Returns:
 *	0	On success.
 *	-1	System error.
 *
 * Infinite while-loop which monitors incoming messages for the agent.
 * Invoke the established message handlers for incoming messages on a per
 * port basis.  Handle timeouts.
 */
static int
receive(void)
{
    int             numfds;
    netsnmp_large_fd_set readfds, writefds, exceptfds;
    struct timeval  timeout, *tvp = &timeout;
    int             count, block, i;
#ifdef	USING_SMUX_MODULE
    int             sd;
#endif                          /* USING_SMUX_MODULE */

    netsnmp_large_fd_set_init(&readfds, FD_SETSIZE);
    netsnmp_large_fd_set_init(&writefds, FD_SETSIZE);
    netsnmp_large_fd_set_init(&exceptfds, FD_SETSIZE);

    /*
     * ignore early sighup during startup
     */
    reconfig = 0;

#if defined(WIN32)
    create_stdin_waiter_thread();
#endif

    /*
     * Loop-forever: execute message handlers for sockets with data
     */
    while (netsnmp_running) {
        if (reconfig) {
#if HAVE_SIGHOLD
            sighold(SIGHUP);
#endif
            reconfig = 0;
            snmp_log(LOG_INFO, "Reconfiguring daemon\n");
	    /*  Stop and restart logging.  This allows logfiles to be
		rotated etc.  */
	    netsnmp_logging_restart();
	    snmp_log(LOG_INFO, "NET-SNMP version %s restarted\n",
		     netsnmp_get_version());
            update_config();
            send_easy_trap(SNMP_TRAP_ENTERPRISESPECIFIC, 3);
#if HAVE_SIGHOLD
            sigrelse(SIGHUP);
#endif
        }

        /*
         * default to sleeping for a really long time. INT_MAX
         * should be sufficient (eg we don't care if time_t is
         * a long that's bigger than an int).
         */
        tvp = &timeout;
        tvp->tv_sec = INT_MAX;
        tvp->tv_usec = 0;

        numfds = 0;
        NETSNMP_LARGE_FD_ZERO(&readfds);
        NETSNMP_LARGE_FD_ZERO(&writefds);
        NETSNMP_LARGE_FD_ZERO(&exceptfds);
        block = 0;
        snmp_select_info2(&numfds, &readfds, tvp, &block);
        if (block == 1) {
            tvp = NULL;         /* block without timeout */
	}

#ifdef	USING_SMUX_MODULE
        if (smux_listen_sd >= 0) {
            NETSNMP_LARGE_FD_SET(smux_listen_sd, &readfds);
            numfds =
                smux_listen_sd >= numfds ? smux_listen_sd + 1 : numfds;

            for (i = 0; i < smux_snmp_select_list_get_length(); i++) {
                sd = smux_snmp_select_list_get_SD_from_List(i);
                if (sd != 0)
                {
                   NETSNMP_LARGE_FD_SET(sd, &readfds);
                   numfds = sd >= numfds ? sd + 1 : numfds;
                }
            }
        }
#endif                          /* USING_SMUX_MODULE */

#ifndef NETSNMP_FEATURE_REMOVE_FD_EVENT_MANAGER
        netsnmp_external_event_info2(&numfds, &readfds, &writefds, &exceptfds);
#endif /* NETSNMP_FEATURE_REMOVE_FD_EVENT_MANAGER */

    reselect:
        for (i = 0; i < NUM_EXTERNAL_SIGS; i++) {
            if (external_signal_scheduled[i]) {
                external_signal_scheduled[i]--;
                external_signal_handler[i](i);
            }
        }

        DEBUGMSGTL(("snmpd/select", "select( numfds=%d, ..., tvp=%p)\n",
                    numfds, tvp));
        if (tvp)
            DEBUGMSGTL(("timer", "tvp %ld.%ld\n", (long) tvp->tv_sec,
                        (long) tvp->tv_usec));
        count = netsnmp_large_fd_set_select(numfds, &readfds, &writefds, &exceptfds,
				     tvp);
        DEBUGMSGTL(("snmpd/select", "returned, count = %d\n", count));

        if (count > 0) {

#ifdef USING_SMUX_MODULE
            /*
             * handle the SMUX sd's 
             */
            if (smux_listen_sd >= 0) {
                for (i = 0; i < smux_snmp_select_list_get_length(); i++) {
                    sd = smux_snmp_select_list_get_SD_from_List(i);
                    if (NETSNMP_LARGE_FD_ISSET(sd, &readfds)) {
                        if (smux_process(sd) < 0) {
                            smux_snmp_select_list_del(sd);
                        }
                    }
                }
                /*
                 * new connection 
                 */
                if (NETSNMP_LARGE_FD_ISSET(smux_listen_sd, &readfds)) {
                    if ((sd = smux_accept(smux_listen_sd)) >= 0) {
                        smux_snmp_select_list_add(sd);
                    }
                }
            }

#endif                          /* USING_SMUX_MODULE */

#ifndef NETSNMP_FEATURE_REMOVE_FD_EVENT_MANAGER
            netsnmp_dispatch_external_events2(&count, &readfds,
                                              &writefds, &exceptfds);
#endif /* NETSNMP_FEATURE_REMOVE_FD_EVENT_MANAGER */

            /* If there are still events leftover, process them */
            if (count > 0) {
              snmp_read2(&readfds);
            }
        } else
            switch (count) {
            case 0:
                snmp_timeout();
                break;
            case -1:
                DEBUGMSGTL(("snmpd/select", "  errno = %d\n", errno));
                if (errno == EINTR) {
                    /*
                     * likely that we got a signal. Check our special signal
                     * flags before retrying select.
                     */
		    if (netsnmp_running && !reconfig) {
                        goto reselect;
		    }
                    continue;
                } else {
                    snmp_log_perror("select");
                }
                return -1;
            default:
                snmp_log(LOG_ERR, "select returned %d\n", count);
                return -1;
            }                   /* endif -- count>0 */

        /*
         * see if persistent store needs to be saved
         */
        snmp_store_if_needed();

        /*
         * run requested alarms 
         */
        run_alarms();

        netsnmp_check_outstanding_agent_requests();

    }                           /* endwhile */

    netsnmp_large_fd_set_cleanup(&readfds);
    netsnmp_large_fd_set_cleanup(&writefds);
    netsnmp_large_fd_set_cleanup(&exceptfds);

#if defined(WIN32)
    join_stdin_waiter_thread();
#endif

    snmp_log(LOG_INFO, "Received TERM or STOP signal...  shutting down...\n");
    return 0;

}                               /* end receive() */
Beispiel #2
0
/*******************************************************************-o-******
 * receive
 *
 * Parameters:
 *
 * Returns:
 *  0   On success.
 *  -1  System error.
 *
 * Infinite while-loop which monitors incoming messages for the agent.
 * Invoke the established message handlers for incoming messages on a per
 * port basis.  Handle timeouts.
 */
static int
receive(void)
{
    int             numfds;

    netsnmp_large_fd_set readfds, writefds, exceptfds;
    struct timeval  timeout, *tvp = &timeout;
    int             count, block, i;

    netsnmp_large_fd_set_init(&readfds, FD_SETSIZE);
    netsnmp_large_fd_set_init(&writefds, FD_SETSIZE);
    netsnmp_large_fd_set_init(&exceptfds, FD_SETSIZE);

    /*
     * you're main loop here... 
     */
    while (ams_running) {
	/* following code from snmpd */
        /*
         * if you use select(), see snmp_select_info() in snmp_api(3) 
         */
        /*
         * default to sleeping for a really long time. INT_MAX
         * should be sufficient (eg we don't care if time_t is
         * a long that's bigger than an int).
         */
        tvp = &timeout;
        tvp->tv_sec = INT_MAX;
        tvp->tv_usec = 0;

        numfds = 0;
        NETSNMP_LARGE_FD_ZERO(&readfds);
        NETSNMP_LARGE_FD_ZERO(&writefds);
        NETSNMP_LARGE_FD_ZERO(&exceptfds);
        block = 0;
        snmp_sess_select_info2_flags(0, &numfds, &readfds, tvp, &block, 
                                     NETSNMP_SELECT_NOFLAGS);

        if (block == 1) {
            tvp = NULL;         /* block without timeout */
	}

        netsnmp_external_event_info2(&numfds, &readfds, &writefds, &exceptfds);

    reselect:
        for (i = 0; i < NUM_EXTERNAL_SIGS; i++) {
            if (external_signal_scheduled[i]) {
                external_signal_scheduled[i]--;
                external_signal_handler[i](i);
            }
        }

        DEBUGMSGTL(("snmpd/select", "select( numfds=%d, ..., tvp=%p)\n",
                    numfds, tvp));
        if (tvp)
            DEBUGMSGTL(("timer", "tvp %ld.%ld\n", (long) tvp->tv_sec,
                        (long) tvp->tv_usec));
        count = netsnmp_large_fd_set_select(numfds, &readfds, &writefds, &exceptfds,
				     tvp);
        DEBUGMSGTL(("snmpd/select", "returned, count = %d\n", count));

        if (count > 0) {
            netsnmp_dispatch_external_events2(&count, &readfds,
                                              &writefds, &exceptfds);

            /* If there are still events leftover, process them */
            if (count > 0) {
              snmp_read2(&readfds);
            }
        } else
            switch (count) {
            case 0:
                snmp_timeout();
                break;
            case -1:
                DEBUGMSGTL(("snmpd/select", "  errno = %d\n", errno));
                if (errno == EINTR) {
                    /*
                     * likely that we got a signal. Check our special signal
                     * flags before retrying select.
                     */
		    if (ams_running) {
                        goto reselect;
		    }
                    continue;
                } else {
                    snmp_log_perror("select");
                }
                return -1;
            default:
                snmp_log(LOG_ERR, "select returned %d\n", count);
                return -1;
            }                   /* endif -- count>0 */

        /*
         * run requested alarms 
         */
        run_alarms();

        netsnmp_check_outstanding_agent_requests();
    }
    /* lets give a seconb or 2 to log the shutdown */
    sleep(0);
    netsnmp_large_fd_set_cleanup(&readfds);
    netsnmp_large_fd_set_cleanup(&writefds);
    netsnmp_large_fd_set_cleanup(&exceptfds);

    /*
     * at shutdown time 
     */


    snmp_log(LOG_INFO, "Received TERM or STOP signal...  shutting down...\n");
    return 0;
}                               /* end receive() */