Esempio n. 1
0
main(int argc, char *argv[])
#endif
{
    char            options[128] = "aAc:CdD::fhHI:l:L:m:M:n:p:P:qrsS:UvV-:Y:";
    int             arg, i, ret;
    int             dont_fork = 0, do_help = 0;
    int             log_set = 0;
    int             agent_mode = -1;
    char           *pid_file = NULL;
    char            option_compatability[] = "-Le";
#ifndef WIN32
    int             prepared_sockets = 0;
#endif
#if HAVE_GETPID
    int fd;
    FILE           *PID;
#endif

#ifndef WIN32
#ifndef NETSNMP_NO_SYSTEMD
    /* check if systemd has sockets for us and don't close them */
    prepared_sockets = netsnmp_sd_listen_fds(0);
#endif /* NETSNMP_NO_SYSTEMD */

    /*
     * close all non-standard file descriptors we may have
     * inherited from the shell.
     */
    if (!prepared_sockets) {
        for (i = getdtablesize() - 1; i > 2; --i) {
            (void) close(i);
        }
    }
#endif /* #WIN32 */
    
    /*
     * register signals ASAP to prevent default action (usually core)
     * for signals during startup...
     */
#ifdef SIGTERM
    DEBUGMSGTL(("signal", "registering SIGTERM signal handler\n"));
    signal(SIGTERM, SnmpdShutDown);
#endif
#ifdef SIGINT
    DEBUGMSGTL(("signal", "registering SIGINT signal handler\n"));
    signal(SIGINT, SnmpdShutDown);
#endif
#ifdef SIGHUP
    signal(SIGHUP, SIG_IGN);   /* do not terminate on early SIGHUP */
#endif
#ifdef SIGUSR1
    DEBUGMSGTL(("signal", "registering SIGUSR1 signal handler\n"));
    signal(SIGUSR1, SnmpdDump);
#endif
#ifdef SIGPIPE
    DEBUGMSGTL(("signal", "registering SIGPIPE signal handler\n"));
    signal(SIGPIPE, SIG_IGN);   /* 'Inline' failure of wayward readers */
#endif
#ifdef SIGXFSZ
    signal(SIGXFSZ, SnmpdCatchRandomSignal);
#endif

#ifdef NETSNMP_NO_ROOT_ACCESS
    /*
     * Default to no.  
     */
    netsnmp_ds_set_boolean(NETSNMP_DS_APPLICATION_ID, 
			   NETSNMP_DS_AGENT_NO_ROOT_ACCESS, 1);
#endif
    /*
     * Default to NOT running an AgentX master.  
     */
    netsnmp_ds_set_boolean(NETSNMP_DS_APPLICATION_ID, 
			   NETSNMP_DS_AGENT_AGENTX_MASTER, 0);
    netsnmp_ds_set_int(NETSNMP_DS_APPLICATION_ID,
                       NETSNMP_DS_AGENT_AGENTX_TIMEOUT, -1);
    netsnmp_ds_set_int(NETSNMP_DS_APPLICATION_ID,
                       NETSNMP_DS_AGENT_AGENTX_RETRIES, -1);

    netsnmp_ds_set_int(NETSNMP_DS_APPLICATION_ID,
                       NETSNMP_DS_AGENT_CACHE_TIMEOUT, 5);
    /*
     * Add some options if they are available.  
     */
#if HAVE_UNISTD_H
    strcat(options, "g:u:");
#endif
#if defined(USING_AGENTX_SUBAGENT_MODULE)|| defined(USING_AGENTX_MASTER_MODULE)
    strcat(options, "x:");
#endif
#ifdef USING_AGENTX_SUBAGENT_MODULE
    strcat(options, "X");
#endif

    /*
     * This is incredibly ugly, but it's probably the simplest way
     *  to handle the old '-L' option as well as the new '-Lx' style
     */
    for (i=0; i<argc; i++) {
        if (!strcmp(argv[i], "-L"))
            argv[i] = option_compatability;            
    }

#ifndef NETSNMP_FEATURE_REMOVE_LOGGING_SYSLOG
#ifdef WIN32
    snmp_log_syslogname(app_name_long);
#else
    snmp_log_syslogname(app_name);
#endif
#endif /* NETSNMP_FEATURE_REMOVE_LOGGING_SYSLOG */
    netsnmp_ds_set_string(NETSNMP_DS_LIBRARY_ID,
                          NETSNMP_DS_LIB_APPTYPE, app_name);

    /*
     * Now process options normally.  
     */
    while ((arg = getopt(argc, argv, options)) != EOF) {
        switch (arg) {
        case '-':
            if (strcasecmp(optarg, "help") == 0) {
                usage(argv[0]);
            }
            if (strcasecmp(optarg, "version") == 0) {
                version();
            }

            handle_long_opt(optarg);
            break;

        case 'a':
            log_addresses++;
            break;

        case 'A':
            netsnmp_ds_set_boolean(NETSNMP_DS_LIBRARY_ID,
                                   NETSNMP_DS_LIB_APPEND_LOGFILES, 1);
            break;

        case 'c':
            if (optarg != NULL) {
                netsnmp_ds_set_string(NETSNMP_DS_LIBRARY_ID, 
				      NETSNMP_DS_LIB_OPTIONALCONFIG, optarg);
            } else {
                usage(argv[0]);
            }
            break;

        case 'C':
            netsnmp_ds_set_boolean(NETSNMP_DS_LIBRARY_ID, 
				   NETSNMP_DS_LIB_DONT_READ_CONFIGS, 1);
            break;

        case 'd':
            netsnmp_ds_set_boolean(NETSNMP_DS_LIBRARY_ID,
                                   NETSNMP_DS_LIB_DUMP_PACKET,
                                   ++snmp_dump_packet);
            break;

        case 'D':
            debug_register_tokens(optarg);
            snmp_set_do_debugging(1);
            break;

        case 'f':
            dont_fork = 1;
            break;

#if HAVE_UNISTD_H
        case 'g':
            if (optarg != NULL) {
                char           *ecp;
                int             gid;

                gid = strtoul(optarg, &ecp, 10);
#if HAVE_GETGRNAM && HAVE_PWD_H
                if (*ecp) {
                    struct group  *info;

                    info = getgrnam(optarg);
                    gid = info ? info->gr_gid : -1;
                    endgrent();
                }
#endif
                if (gid < 0) {
                    fprintf(stderr, "Bad group id: %s\n", optarg);
                    exit(1);
                }
                netsnmp_ds_set_int(NETSNMP_DS_APPLICATION_ID, 
				   NETSNMP_DS_AGENT_GROUPID, gid);
            } else {
                usage(argv[0]);
            }
            break;
#endif

        case 'h':
            usage(argv[0]);
            break;

        case 'H':
            do_help = 1;
            break;

        case 'I':
            if (optarg != NULL) {
                add_to_init_list(optarg);
            } else {
                usage(argv[0]);
            }
            break;

#ifndef NETSNMP_FEATURE_REMOVE_LOGGING_FILE
        case 'l':
            printf("Warning: -l option is deprecated, use -Lf <file> instead\n");
            if (optarg != NULL) {
                if (strlen(optarg) > PATH_MAX) {
                    fprintf(stderr,
                            "%s: logfile path too long (limit %d chars)\n",
                            argv[0], PATH_MAX);
                    exit(1);
                }
                snmp_enable_filelog(optarg,
                                    netsnmp_ds_get_boolean(NETSNMP_DS_LIBRARY_ID,
                                                           NETSNMP_DS_LIB_APPEND_LOGFILES));
                log_set = 1;
            } else {
                usage(argv[0]);
            }
            break;
#endif /* NETSNMP_FEATURE_REMOVE_LOGGING_FILE */

        case 'L':
	    if  (snmp_log_options( optarg, argc, argv ) < 0 ) {
                usage(argv[0]);
            }
            log_set = 1;
            break;

        case 'm':
            if (optarg != NULL) {
                setenv("MIBS", optarg, 1);
            } else {
                usage(argv[0]);
            }
            break;

        case 'M':
            if (optarg != NULL) {
                setenv("MIBDIRS", optarg, 1);
            } else {
                usage(argv[0]);
            }
            break;

        case 'n':
            if (optarg != NULL) {
                app_name = optarg;
                netsnmp_ds_set_string(NETSNMP_DS_LIBRARY_ID,
                                      NETSNMP_DS_LIB_APPTYPE, app_name);
            } else {
                usage(argv[0]);
            }
            break;

        case 'P':
            printf("Warning: -P option is deprecated, use -p instead\n");
        case 'p':
            if (optarg != NULL) {
                pid_file = optarg;
            } else {
                usage(argv[0]);
            }
            break;

        case 'q':
            netsnmp_ds_set_boolean(NETSNMP_DS_LIBRARY_ID, 
                                   NETSNMP_DS_LIB_QUICK_PRINT, 1);
            break;

        case 'r':
            netsnmp_ds_toggle_boolean(NETSNMP_DS_APPLICATION_ID, 
				      NETSNMP_DS_AGENT_NO_ROOT_ACCESS);
            break;

#ifndef NETSNMP_FEATURE_REMOVE_LOGGING_SYSLOG
        case 's':
            printf("Warning: -s option is deprecated, use -Lsd instead\n");
            snmp_enable_syslog();
            log_set = 1;
            break;

        case 'S':
            printf("Warning: -S option is deprecated, use -Ls <facility> instead\n");
            if (optarg != NULL) {
                switch (*optarg) {
                case 'd':
                case 'D':
                    Facility = LOG_DAEMON;
                    break;
                case 'i':
                case 'I':
                    Facility = LOG_INFO;
                    break;
                case '0':
                    Facility = LOG_LOCAL0;
                    break;
                case '1':
                    Facility = LOG_LOCAL1;
                    break;
                case '2':
                    Facility = LOG_LOCAL2;
                    break;
                case '3':
                    Facility = LOG_LOCAL3;
                    break;
                case '4':
                    Facility = LOG_LOCAL4;
                    break;
                case '5':
                    Facility = LOG_LOCAL5;
                    break;
                case '6':
                    Facility = LOG_LOCAL6;
                    break;
                case '7':
                    Facility = LOG_LOCAL7;
                    break;
                default:
                    fprintf(stderr, "invalid syslog facility: -S%c\n",*optarg);
                    usage(argv[0]);
                }
                snmp_enable_syslog_ident(snmp_log_syslogname(NULL), Facility);
                log_set = 1;
            } else {
                fprintf(stderr, "no syslog facility specified\n");
                usage(argv[0]);
            }
            break;
#endif /* NETSNMP_FEATURE_REMOVE_LOGGING_SYSLOG */

        case 'U':
            netsnmp_ds_toggle_boolean(NETSNMP_DS_APPLICATION_ID, 
				      NETSNMP_DS_AGENT_LEAVE_PIDFILE);
            break;

#if HAVE_UNISTD_H
        case 'u':
            if (optarg != NULL) {
                char           *ecp;
                int             uid;

                uid = strtoul(optarg, &ecp, 10);
#if HAVE_GETPWNAM && HAVE_PWD_H
                if (*ecp) {
                    struct passwd  *info;

                    info = getpwnam(optarg);
                    uid = info ? info->pw_uid : -1;
                    endpwent();
                }
#endif
                if (uid < 0) {
                    fprintf(stderr, "Bad user id: %s\n", optarg);
                    exit(1);
                }
                netsnmp_ds_set_int(NETSNMP_DS_APPLICATION_ID, 
				   NETSNMP_DS_AGENT_USERID, uid);
            } else {
                usage(argv[0]);
            }
            break;
#endif

        case 'v':
            version();

        case 'V':
            netsnmp_ds_set_boolean(NETSNMP_DS_APPLICATION_ID, 
				   NETSNMP_DS_AGENT_VERBOSE, 1);
            break;

#if defined(USING_AGENTX_SUBAGENT_MODULE)|| defined(USING_AGENTX_MASTER_MODULE)
        case 'x':
            if (optarg != NULL) {
                netsnmp_ds_set_string(NETSNMP_DS_APPLICATION_ID, 
				      NETSNMP_DS_AGENT_X_SOCKET, optarg);
            } else {
                usage(argv[0]);
            }
            netsnmp_ds_set_boolean(NETSNMP_DS_APPLICATION_ID, 
				   NETSNMP_DS_AGENT_AGENTX_MASTER, 1);
            break;
#endif

        case 'X':
#if defined(USING_AGENTX_SUBAGENT_MODULE)
            agent_mode = SUB_AGENT;
#else
            fprintf(stderr, "%s: Illegal argument -X:"
		            "AgentX support not compiled in.\n", argv[0]);
            usage(argv[0]);
            exit(1);
#endif
            break;

        case 'Y':
            netsnmp_config_remember(optarg);
            break;

        default:
            usage(argv[0]);
            break;
        }
    }

    if (do_help) {
        netsnmp_ds_set_boolean(NETSNMP_DS_APPLICATION_ID, 
                               NETSNMP_DS_AGENT_NO_ROOT_ACCESS, 1);
        init_agent(app_name);        /* register our .conf handlers */
        init_mib_modules();
        init_snmp(app_name);
        fprintf(stderr, "Configuration directives understood:\n");
        read_config_print_usage("  ");
        exit(0);
    }

    if (optind < argc) {
#ifndef NETSNMP_NO_LISTEN_SUPPORT
        /*
         * There are optional transport addresses on the command line.  
         */
        DEBUGMSGTL(("snmpd/main", "optind %d, argc %d\n", optind, argc));
        for (i = optind; i < argc; i++) {
            char *c, *astring;
            if ((c = netsnmp_ds_get_string(NETSNMP_DS_APPLICATION_ID, 
					   NETSNMP_DS_AGENT_PORTS))) {
                astring = (char*)malloc(strlen(c) + 2 + strlen(argv[i]));
                if (astring == NULL) {
                    fprintf(stderr, "malloc failure processing argv[%d]\n", i);
                    exit(1);
                }
                sprintf(astring, "%s,%s", c, argv[i]);
                netsnmp_ds_set_string(NETSNMP_DS_APPLICATION_ID, 
				      NETSNMP_DS_AGENT_PORTS, astring);
                SNMP_FREE(astring);
            } else {
                netsnmp_ds_set_string(NETSNMP_DS_APPLICATION_ID, 
				      NETSNMP_DS_AGENT_PORTS, argv[i]);
            }
        }
        DEBUGMSGTL(("snmpd/main", "port spec: %s\n",
                    netsnmp_ds_get_string(NETSNMP_DS_APPLICATION_ID, 
					  NETSNMP_DS_AGENT_PORTS)));
#else /* NETSNMP_NO_LISTEN_SUPPORT */
        fprintf(stderr, "You specified ports to open; this agent was built to only send notifications\n");
        exit(1);
#endif /* NETSNMP_NO_LISTEN_SUPPORT */
    }

#ifdef NETSNMP_LOGFILE
#ifndef NETSNMP_FEATURE_REMOVE_LOGGING_FILE
    if (0 == log_set)
        snmp_enable_filelog(NETSNMP_LOGFILE,
                            netsnmp_ds_get_boolean(NETSNMP_DS_LIBRARY_ID,
                                                   NETSNMP_DS_LIB_APPEND_LOGFILES));
#endif /* NETSNMP_FEATURE_REMOVE_LOGGING_FILE */
#endif

#ifdef USING_UTIL_FUNCS_RESTART_MODULE
    {
        /*
         * Initialize a argv set to the current for restarting the agent.
         */
        char *cptr, **argvptr;

        argvrestartp = (char **)malloc((argc + 2) * sizeof(char *));
        argvptr = argvrestartp;
        for (i = 0, ret = 1; i < argc; i++) {
            ret += strlen(argv[i]) + 1;
        }
        argvrestart = (char *) malloc(ret);
        argvrestartname = (char *) malloc(strlen(argv[0]) + 1);
        if (!argvrestartp || !argvrestart || !argvrestartname) {
            fprintf(stderr, "malloc failure processing argvrestart\n");
            exit(1);
        }
        strcpy(argvrestartname, argv[0]);

        for (cptr = argvrestart, i = 0; i < argc; i++) {
            strcpy(cptr, argv[i]);
            *(argvptr++) = cptr;
            cptr += strlen(argv[i]) + 1;
        }
    }
#endif /* USING_UTIL_FUNCS_RESTART_MODULE */

    if (agent_mode == -1) {
        if (strstr(argv[0], "agentxd") != NULL) {
            netsnmp_ds_set_boolean(NETSNMP_DS_APPLICATION_ID,
				   NETSNMP_DS_AGENT_ROLE, SUB_AGENT);
        } else {
            netsnmp_ds_set_boolean(NETSNMP_DS_APPLICATION_ID,
				   NETSNMP_DS_AGENT_ROLE, MASTER_AGENT);
        }
    } else {
        netsnmp_ds_set_boolean(NETSNMP_DS_APPLICATION_ID,
			       NETSNMP_DS_AGENT_ROLE, agent_mode);
    }

    SOCK_STARTUP;
    if (init_agent(app_name) != 0) {
        snmp_log(LOG_ERR, "Agent initialization failed\n");
        exit(1);
    }
    init_mib_modules();

    /*
     * start library 
     */
    init_snmp(app_name);

    if ((ret = init_master_agent()) != 0) {
        /*
         * Some error opening one of the specified agent transports.  
         */
        snmp_log(LOG_ERR, "Server Exiting with code 1\n");
        exit(1);
    }

    /*
     * Initialize the world.  Detach from the shell.  Create initial user.  
     */
    if(!dont_fork) {
        int quit = ! netsnmp_ds_get_boolean(NETSNMP_DS_APPLICATION_ID,
                                            NETSNMP_DS_AGENT_QUIT_IMMEDIATELY);
        ret = netsnmp_daemonize(quit,
#ifndef NETSNMP_FEATURE_REMOVE_LOGGING_STDIO
                                snmp_stderrlog_status()
#else /* NETSNMP_FEATURE_REMOVE_LOGGING_STDIO */
                                0
#endif /* NETSNMP_FEATURE_REMOVE_LOGGING_STDIO */
            );
        /*
         * xxx-rks: do we care if fork fails? I think we should...
         */
        if(ret != 0) {
            snmp_log(LOG_ERR, "Server Exiting with code 1\n");
            exit(1);
        }
    }

#if HAVE_GETPID
    if (pid_file != NULL) {
        /*
         * unlink the pid_file, if it exists, prior to open.  Without
         * doing this the open will fail if the user specified pid_file
         * already exists.
         */
        unlink(pid_file);
        fd = open(pid_file, O_CREAT | O_EXCL | O_WRONLY, 0600);
        if (fd == -1) {
            snmp_log_perror(pid_file);
            if (!netsnmp_ds_get_boolean(NETSNMP_DS_APPLICATION_ID, 
                                        NETSNMP_DS_AGENT_NO_ROOT_ACCESS)) {
                exit(1);
            }
        } else {
            if ((PID = fdopen(fd, "w")) == NULL) {
                snmp_log_perror(pid_file);
                exit(1);
            } else {
                fprintf(PID, "%d\n", (int) getpid());
                fclose(PID);
            }
#ifndef _MSC_VER
            /* The sequence open()/fdopen()/fclose()/close() makes MSVC crash,
               hence skip the close() call when using the MSVC runtime. */
            close(fd);
#endif
        }
    }
#endif

#if defined(HAVE_UNISTD_H) && (defined(HAVE_CHOWN) || defined(HAVE_SETGID) || defined(HAVE_SETUID))
    {
    const char     *persistent_dir;
    int             uid, gid;

    persistent_dir = get_persistent_directory();
    mkdirhier( persistent_dir, NETSNMP_AGENT_DIRECTORY_MODE, 0 );
   
    uid = netsnmp_ds_get_int(NETSNMP_DS_APPLICATION_ID, 
			     NETSNMP_DS_AGENT_USERID);
    gid = netsnmp_ds_get_int(NETSNMP_DS_APPLICATION_ID, 
			     NETSNMP_DS_AGENT_GROUPID);
    
#ifdef HAVE_CHOWN
    if ( uid != 0 || gid != 0 )
        chown( persistent_dir, uid, gid );
#endif

#ifdef HAVE_SETGID
    if ((gid = netsnmp_ds_get_int(NETSNMP_DS_APPLICATION_ID, 
				  NETSNMP_DS_AGENT_GROUPID)) > 0) {
        DEBUGMSGTL(("snmpd/main", "Changing gid to %d.\n", gid));
        if (setgid(gid) == -1
#ifdef HAVE_SETGROUPS
            || setgroups(1, (gid_t *)&gid) == -1
#endif
            ) {
            snmp_log_perror("setgid failed");
            if (!netsnmp_ds_get_boolean(NETSNMP_DS_APPLICATION_ID, 
					NETSNMP_DS_AGENT_NO_ROOT_ACCESS)) {
                exit(1);
            }
        }
    }
#endif
#ifdef HAVE_SETUID
    if ((uid = netsnmp_ds_get_int(NETSNMP_DS_APPLICATION_ID, 
				  NETSNMP_DS_AGENT_USERID)) > 0) {
#if HAVE_GETPWNAM && HAVE_PWD_H && HAVE_INITGROUPS
        struct passwd *info;

        /*
         * Set supplementary groups before changing UID
         *   (which probably involves giving up privileges)
         */
        info = getpwuid(uid);
        if (info) {
            DEBUGMSGTL(("snmpd/main", "Supplementary groups for %s.\n", info->pw_name));
            if (initgroups(info->pw_name, (gid != 0 ? (gid_t)gid : info->pw_gid)) == -1) {
                snmp_log_perror("initgroups failed");
                if (!netsnmp_ds_get_boolean(NETSNMP_DS_APPLICATION_ID, 
                                            NETSNMP_DS_AGENT_NO_ROOT_ACCESS)) {
                    exit(1);
                }
            }
        }
        endpwent();
#endif
        DEBUGMSGTL(("snmpd/main", "Changing uid to %d.\n", uid));
        if (setuid(uid) == -1) {
            snmp_log_perror("setuid failed");
            if (!netsnmp_ds_get_boolean(NETSNMP_DS_APPLICATION_ID, 
					NETSNMP_DS_AGENT_NO_ROOT_ACCESS)) {
                exit(1);
            }
        }
    }
#endif
    }
#endif

    /*
     * Store persistent data immediately in case we crash later.  
     */
    snmp_store(app_name);

#ifdef SIGHUP
    DEBUGMSGTL(("signal", "registering SIGHUP signal handler\n"));
    signal(SIGHUP, SnmpdReconfig);
#endif

    /*
     * Send coldstart trap if possible.  
     */
    send_easy_trap(0, 0);

    /*
     * We're up, log our version number.  
     */
    snmp_log(LOG_INFO, "NET-SNMP version %s\n", netsnmp_get_version());
#ifdef WIN32SERVICE
    agent_status = AGENT_RUNNING;
#endif
    netsnmp_addrcache_initialise();

    /*
     * Let systemd know we're up.
     */
#ifndef NETSNMP_NO_SYSTEMD
    netsnmp_sd_notify(1, "READY=1\n");
    if (prepared_sockets)
        /*
         * Clear the environment variable, we already processed all the sockets
         * by now.
         */
        netsnmp_sd_listen_fds(1);
#endif

    /*
     * Forever monitor the dest_port for incoming PDUs.  
     */
    DEBUGMSGTL(("snmpd/main", "We're up.  Starting to process data.\n"));
    if (!netsnmp_ds_get_boolean(NETSNMP_DS_APPLICATION_ID, 
				NETSNMP_DS_AGENT_QUIT_IMMEDIATELY))
        receive();
    DEBUGMSGTL(("snmpd/main", "sending shutdown trap\n"));
    SnmpTrapNodeDown();
    DEBUGMSGTL(("snmpd/main", "Bye...\n"));
    snmp_shutdown(app_name);
    shutdown_master_agent();
    shutdown_agent();

    if (!netsnmp_ds_get_boolean(NETSNMP_DS_APPLICATION_ID, 
				NETSNMP_DS_AGENT_LEAVE_PIDFILE) &&
	(pid_file != NULL)) {
        unlink(pid_file);
    }
#ifdef WIN32SERVICE
    agent_status = AGENT_STOPPED;
#endif

#ifdef USING_UTIL_FUNCS_RESTART_MODULE
    SNMP_FREE(argvrestartname);
    SNMP_FREE(argvrestart);
    SNMP_FREE(argvrestartp);
#endif /* USING_UTIL_FUNCS_RESTART_MODULE */

    SOCK_CLEANUP;
    return 0;
}                               /* End main() -- snmpd */
Esempio n. 2
0
static void
updateLogmatch(int iindex)
{

    int             matchResultCode;
    char            inbuf[1024];
    char            perfilename[1024];
    FILE           *perfile;
    unsigned long   pos, ccounter, counter;
    int             result;
    int             toobig;
    int             anyChanges = FALSE;
    struct stat     sb;
    char            lastFilename[256];

    /*
     * ------------------------------------ 
     * we can never be sure if this is the  
     * last time we are being called here,  
     * so we always update a persistent     
     * data file with our current file      
     * position                             
     * ------------------------------------ 
     */

    snprintf(perfilename, sizeof(perfilename), "%s/snmpd_logmatch_%s.pos",
             get_persistent_directory(), logmatchTable[iindex].name);

    if (logmatchTable[iindex].virgin) {

        /*
         * ------------------------------------ 
         * this is the first time we are being  
         * called; let's try to find an old     
         * file position stored in a persistent 
         * data file and restore it             
         * ------------------------------------ 
         */

        if ((perfile = fopen(perfilename, "r"))) {

            /*
             * ------------------------------------ 
             * the persistent data file exists so   
             * let's read it out                    
             * ------------------------------------ 
             */


            pos = counter = ccounter = 0;

            if (fscanf(perfile, "%lu %lu %lu %s",
                       &pos, &ccounter, &counter, lastFilename)) {


                /*
                 * ------------------------------------ 
                 * the data could be read; now let's    
                 * try to open the  logfile to be       
                 * scanned                              
                 * ------------------------------------ 
                 */

                if (logmatch_update_filename(logmatchTable[iindex].filenamePattern,
                                             lastFilename) == 0) {

                    /*
                     * ---------------------------------
                     * the filename is still the same as 
                     * the one stored in the persistent
                     * data file.
                     * ---------------------------------
                     */

                    if ((logmatchTable[iindex].logfile =
                        fopen(logmatchTable[iindex].filename, "r"))) {


                        /*
                         * ------------------------------------ 
                         * the log file could be opened; now    
                         * let's try to set the pointer         
                         * ------------------------------------ 
                         */

                        if (!fseek
                            (logmatchTable[iindex].logfile, pos, SEEK_SET)) {


                            /*
                             * ------------------------------------ 
                             * the pointer could be set - this is   
                             * the most that we can do: if the      
                             * pointer is smaller than the file     
                             * size we must assume that the pointer 
                             * still points to where it read the    
                             * file last time; let's restore the    
                             * data                                 
                             * ------------------------------------ 
                             */

                            logmatchTable[iindex].currentFilePosition = pos;
                            logmatchTable[iindex].currentMatchCounter =
                                ccounter;
                        }

                        fclose(logmatchTable[iindex].logfile);
                    }
                }
                logmatchTable[iindex].globalMatchCounter = counter;
            }

            fclose(perfile);
        }

        logmatchTable[iindex].virgin = FALSE;
    }

    /*
     * -------------------------------------------
     * check if a new input file needs to be opened
     * if yes, reset counter and position
     * -------------------------------------------
     */

    if (logmatch_update_filename(logmatchTable[iindex].filenamePattern,
                                 logmatchTable[iindex].filename) == 1) {
        logmatchTable[iindex].currentFilePosition = 0; 
        logmatchTable[iindex].currentMatchCounter = 0;
    }


    /*
     * ------------------------------------ 
     * now the pointer and the counter are  
     * set either zero or reset to old      
     * value; now let's try to read some    
     * data                                 
     * ------------------------------------ 
     */

    if (stat(logmatchTable[iindex].filename, &sb) == 0) {

        if (logmatchTable[iindex].currentFilePosition > sb.st_size) {
            toobig = TRUE;
        } else {
            toobig = FALSE;
        }

        if ((logmatchTable[iindex].logfile =
            fopen(logmatchTable[iindex].filename, "r"))) {

            result =
                fseek(logmatchTable[iindex].logfile,
                      logmatchTable[iindex].currentFilePosition, SEEK_SET);

            if (result || toobig || (errno == EINVAL)
                || feof(logmatchTable[iindex].logfile)) {


                /*
                 * ------------------------------------ 
                 * when we are here that means we       
                 * could't set the file position maybe  
                 * the file was rotated; let's reset    
                 * the filepointer, but not the counter 
                 * ------------------------------------ 
                 */


                logmatchTable[iindex].currentFilePosition = 0;
                logmatchTable[iindex].currentMatchCounter = 0;
                fseek(logmatchTable[iindex].logfile, 0, SEEK_SET);
                anyChanges = TRUE;
            }

            while (fgets
                   (inbuf, sizeof(inbuf), logmatchTable[iindex].logfile)) {

                matchResultCode =
                    regexec(&(logmatchTable[iindex].regexBuffer),
                            inbuf, 0, NULL, REG_NOTEOL);

                if (matchResultCode == 0) {
                    logmatchTable[iindex].globalMatchCounter++;
                    logmatchTable[iindex].currentMatchCounter++;
                    logmatchTable[iindex].matchCounter++;
                    anyChanges = TRUE;
                }
            }

            logmatchTable[iindex].currentFilePosition =
                ftell(logmatchTable[iindex].logfile);
            fclose(logmatchTable[iindex].logfile);
        }
    }


    /*
     * ------------------------------------ 
     * at this point we can be safe that    
     * our current file position is         
     * straightened out o.k. - we never     
     * know if this is the last time we are 
     * being called so save the position    
     * in a file                            
     * ------------------------------------ 
     */

    if (anyChanges && (perfile = fopen(perfilename, "w"))) {


        /*
         * ------------------------------------ 
         * o.k. lets write out our variable     
         * ------------------------------------ 
         */

        fprintf(perfile, "%lu %lu %lu %s\n",
                logmatchTable[iindex].currentFilePosition,
                logmatchTable[iindex].currentMatchCounter,
                logmatchTable[iindex].globalMatchCounter,
                logmatchTable[iindex].filename);

        fclose(perfile);
    }

}
Esempio n. 3
0
int
get_exec_output(struct extensible *ex)
{
#if HAVE_EXECV && HAVE_FORK
    char            cachefile[STRMAX];
    char            cache[NETSNMP_MAXCACHESIZE];
    ssize_t         cachebytes;
    int             cfd;
#ifdef NETSNMP_EXCACHETIME
    long            curtime;
    static char     lastcmd[STRMAX];
    static int      lastresult;
#endif

    DEBUGMSGTL(("exec:get_exec_output","calling %s\n", ex->command));

    sprintf(cachefile, "%s/%s", get_persistent_directory(), NETSNMP_CACHEFILE);
#ifdef NETSNMP_EXCACHETIME
    curtime = time(NULL);
    if (curtime > (cachetime + NETSNMP_EXCACHETIME) ||
        strcmp(ex->command, lastcmd) != 0) {
        strcpy(lastcmd, ex->command);
        cachetime = curtime;
#endif

        cachebytes = NETSNMP_MAXCACHESIZE;
        ex->result = run_exec_command( ex->command, NULL, cache, &cachebytes );

        unlink(cachefile);
            /*
             * XXX  Use SNMP_FILEMODE_CLOSED instead of 644? 
             */
        if ((cfd = open(cachefile, O_WRONLY | O_TRUNC | O_CREAT, 0600)) < 0) {
                snmp_log(LOG_ERR,"can not create cache file\n");
                setPerrorstatus(cachefile);
                cachetime = 0;
                return -1;
        }
        if (cachebytes > 0)
            write(cfd, (void *) cache, cachebytes);
        close(cfd);
#ifdef NETSNMP_EXCACHETIME
        lastresult = ex->result;
    } else {
        ex->result = lastresult;
    }
#endif
    DEBUGMSGTL(("exec:get_exec_output","using cached value\n"));
    if ((cfd = open(cachefile, O_RDONLY)) < 0) {
        snmp_log(LOG_ERR,"can not open cache file\n");
        setPerrorstatus(cachefile);
        return -1;
    }
    return (cfd);
#else                           /* !HAVE_EXECV || !HAVE_FORK */
#if defined(WIN32) && !defined(HAVE_EXECV)
/* MSVC and MinGW.  Cygwin already works as it has execv and fork */
    int         fd;   
    
    /* Reference:  MS tech note: 190351 */
    HANDLE hOutputReadTmp, hOutputRead, hOutputWrite = NULL;
        
    HANDLE hErrorWrite;
    SECURITY_ATTRIBUTES sa;
    PROCESS_INFORMATION pi;
    STARTUPINFO si;
    
    sa.nLength= sizeof(SECURITY_ATTRIBUTES);
    sa.lpSecurityDescriptor = NULL;
    sa.bInheritHandle = TRUE;

    DEBUGMSGTL(("exec:get_exec_output","calling %s\n", ex->command));
    
    /* Child temporary output pipe with Inheritance on (sa.bInheritHandle is true) */    
    if (!CreatePipe(&hOutputReadTmp,&hOutputWrite,&sa,0)) {
      DEBUGMSGTL(("util_funcs", "get_exec_pipes CreatePipe ChildOut: %d\n",
            GetLastError()));
      return -1;
    }
    
    /* Copy the stdout handle to the stderr handle in case the child closes one of 
     * its stdout handles. */
    if (!DuplicateHandle(GetCurrentProcess(),hOutputWrite, GetCurrentProcess(),
          &hErrorWrite,0, TRUE,DUPLICATE_SAME_ACCESS)) {
      DEBUGMSGTL(("util_funcs", "get_exec_output DuplicateHandle: %d\n", GetLastError()));
      return -1;
    }

    /* Create new copies of the input and output handles but set bInheritHandle to 
     * FALSE so the new handle can not be inherited.  Otherwise the handles can not
     * be closed.  */
    if (!DuplicateHandle(GetCurrentProcess(), hOutputReadTmp, GetCurrentProcess(),
          &hOutputRead, 0, FALSE, DUPLICATE_SAME_ACCESS)) {
      DEBUGMSGTL(("util_funcs", "get_exec_output DupliateHandle ChildOut: %d\n", GetLastError()));
      CloseHandle(hErrorWrite);
      return -1;
    }   

    /* Close the temporary output and input handles */
    if (!CloseHandle(hOutputReadTmp)) {
      DEBUGMSGTL(("util_funcs", "get_exec_output CloseHandle (hOutputReadTmp): %d\n", GetLastError()));
      CloseHandle(hErrorWrite);
      CloseHandle(hOutputRead);
      return -1;
    }
    
    /* Associates a C run-time file descriptor with an existing operating-system file handle. */
    fd = _open_osfhandle((long) hOutputRead, 0);
    
    /* Set up STARTUPINFO for CreateProcess with the handles and have it hide the window
     * for the new process. */
    ZeroMemory(&si,sizeof(STARTUPINFO));
    si.cb = sizeof(STARTUPINFO);
    si.dwFlags = STARTF_USESTDHANDLES | STARTF_USESHOWWINDOW;
    si.hStdOutput = hOutputWrite;
    si.hStdError = hErrorWrite;
    si.wShowWindow = SW_HIDE;
   
    /* Launch the process that you want to redirect.  Example snmpd.conf pass_persist:
     * pass_persist    .1.3.6.1.4.1.2021.255  c:/perl/bin/perl c:/temp/pass_persisttest
    */
    if (!CreateProcess(NULL, ex->command, NULL, NULL, TRUE, CREATE_NEW_CONSOLE, NULL, NULL, &si, &pi)) {
      DEBUGMSGTL(("util_funcs","get_exec_output CreateProcess:'%s' %d\n",ex->command, GetLastError()));
      CloseHandle(hErrorWrite);
      CloseHandle(hOutputRead);
      return -1;
    }
    
    /* Set global child process handle */
    ex->pid = (int)pi.hProcess;
    ex->tid = (int)pi.hThread;

    /* Close pipe handles to make sure that no handles to the write end of the
     * output pipe are maintained in this process or else the pipe will
     * not close when the child process exits and any calls to ReadFile 
     * will hang.
     */

    if (!CloseHandle(hOutputWrite)){
      DEBUGMSGTL(("util_funcs","get_exec_output CloseHandle hOutputWrite: %d\n",ex->command, GetLastError()));
      return -1;
    }
    if (!CloseHandle(hErrorWrite)) {
      DEBUGMSGTL(("util_funcs","get_exec_output CloseHandle hErrorWrite: %d\n",ex->command, GetLastError()));
      return -1;
    }
    return fd;
#endif                          /* WIN32 */
    return -1;
#endif
}
Esempio n. 4
0
int
get_exec_output(struct extensible *ex)
{
#if HAVE_EXECV
    int             fd[2], i, cnt;
    char            ctmp[STRMAX], *cptr1, *cptr2, argvs[STRMAX], **argv,
        **aptr;
#ifdef EXCACHETIME
    char            cachefile[STRMAX];
    char            cache[MAXCACHESIZE];
    ssize_t         cachebytes;
    long            curtime;
    static char     lastcmd[STRMAX];
    int             cfd;
    static int      lastresult;
    int             readcount;
#endif

#ifdef EXCACHETIME
    sprintf(cachefile, "%s/%s", get_persistent_directory(), CACHEFILE);
    curtime = time(NULL);
    if (curtime > (cachetime + EXCACHETIME) ||
        strcmp(ex->command, lastcmd) != 0) {
        strcpy(lastcmd, ex->command);
        cachetime = curtime;
#endif
        if (pipe(fd)) {
            setPerrorstatus("pipe");
#ifdef EXCACHETIME
            cachetime = 0;
#endif
            return -1;
        }
        if ((ex->pid = fork()) == 0) {
            close(1);
            if (dup(fd[1]) != 1) {
                setPerrorstatus("dup");
                return -1;
            }

            /*
             * write standard output and standard error to pipe. 
             */
            /*
             * close all other file descriptors. 
             */
            for (cnt = getdtablesize() - 1; cnt >= 2; --cnt)
                (void) close(cnt);
            (void) dup(1);      /* stderr */

            /*
             * set standard input to /dev/null 
             */
            close(0);
            (void) open("/dev/null", O_RDWR);

            for (cnt = 1, cptr1 = ex->command, cptr2 = argvs;
                 cptr1 && *cptr1 != 0; cptr2++, cptr1++) {
                *cptr2 = *cptr1;
                if (*cptr1 == ' ') {
                    *(cptr2++) = 0;
                    if ((cptr1 = skip_white(cptr1)) == NULL)
                        break;
                    if (cptr1) {
                        *cptr2 = *cptr1;
                        if (*cptr1 != 0)
                            cnt++;
                    }
                }
            }
            *cptr2 = 0;
            *(cptr2 + 1) = 0;
            argv = (char **) malloc((cnt + 2) * sizeof(char *));
            if (argv == NULL)
                return 0;       /* memory alloc error */
            aptr = argv;
            *(aptr++) = argvs;
            for (cptr2 = argvs, i = 1; i != cnt; cptr2++)
                if (*cptr2 == 0) {
                    *(aptr++) = cptr2 + 1;
                    i++;
                }
            while (*cptr2 != 0)
                cptr2++;
            *(aptr++) = NULL;
            copy_nword(ex->command, ctmp, sizeof(ctmp));
            execv(ctmp, argv);
            perror(ctmp);
            exit(1);
        } else {
            close(fd[1]);
            if (ex->pid < 0) {
                close(fd[0]);
                setPerrorstatus("fork");
#ifdef EXCACHETIME
                cachetime = 0;
#endif
                return -1;
            }
#ifdef EXCACHETIME
            unlink(cachefile);
            /*
             * XXX  Use SNMP_FILEMODE_CLOSED instead of 644? 
             */
            if ((cfd =
                 open(cachefile, O_WRONLY | O_TRUNC | O_CREAT,
                      0644)) < 0) {
                setPerrorstatus(cachefile);
                cachetime = 0;
                return -1;
            }
            fcntl(fd[0], F_SETFL, O_NONBLOCK);  /* don't block on reads */
#ifdef HAVE_USLEEP
            for (readcount = 0; readcount <= MAXREADCOUNT * 100 &&
                 (cachebytes = read(fd[0], (void *) cache, MAXCACHESIZE));
                 readcount++) {
#else
            for (readcount = 0; readcount <= MAXREADCOUNT &&
                 (cachebytes = read(fd[0], (void *) cache, MAXCACHESIZE));
                 readcount++) {
#endif
                if (cachebytes > 0)
                    write(cfd, (void *) cache, cachebytes);
                else if (cachebytes == -1 && errno != EAGAIN) {
                    setPerrorstatus("read");
                    break;
                } else
#ifdef HAVE_USLEEP
                    usleep(10000);      /* sleeps for 0.01 sec */
#else
                    sleep(1);
#endif
            }
            close(cfd);
            close(fd[0]);
            /*
             * wait for the child to finish 
             */
            if (ex->pid > 0 && waitpid(ex->pid, &ex->result, 0) < 0) {
                setPerrorstatus("waitpid()");
                cachetime = 0;
                return -1;
            }
            ex->pid = 0;
            ex->result = WEXITSTATUS(ex->result);
            lastresult = ex->result;
#else                           /* !EXCACHETIME */
            return (fd[0]);
#endif
        }
#ifdef EXCACHETIME
    } else {
Esempio n. 5
0
netsnmp_transport *
netsnmp_ssh_transport(const struct sockaddr_in *addr, int local)
{
    netsnmp_transport *t = NULL;
    netsnmp_ssh_addr_pair *addr_pair = NULL;
    int rc = 0;
    int i, auth_pw = 0;
    const char *fingerprint;
    char *userauthlist;
    struct sockaddr_un *unaddr;
    const char *sockpath =
        netsnmp_ds_get_string(NETSNMP_DS_LIBRARY_ID,
                              NETSNMP_DS_LIB_SSHTOSNMP_SOCKET);
    char tmpsockpath[MAXPATHLEN];

#ifdef NETSNMP_NO_LISTEN_SUPPORT
    if (local)
        return NULL;
#endif /* NETSNMP_NO_LISTEN_SUPPORT */

    if (addr == NULL || addr->sin_family != AF_INET) {
        return NULL;
    }

    t = SNMP_MALLOC_TYPEDEF(netsnmp_transport);
    if (t == NULL) {
        return NULL;
    }

    t->domain = netsnmp_snmpSSHDomain;
    t->domain_length = netsnmp_snmpSSHDomain_len;
    t->flags = NETSNMP_TRANSPORT_FLAG_STREAM | NETSNMP_TRANSPORT_FLAG_TUNNELED;

    addr_pair = SNMP_MALLOC_TYPEDEF(netsnmp_ssh_addr_pair);
    if (addr_pair == NULL) {
        netsnmp_transport_free(t);
        return NULL;
    }
    t->data = addr_pair;
    t->data_length = sizeof(netsnmp_ssh_addr_pair);

    if (local) {
#ifndef NETSNMP_NO_LISTEN_SUPPORT
#ifdef SNMPSSHDOMAIN_USE_EXTERNAL_PIPE

        /* XXX: set t->local and t->local_length */


        t->flags |= NETSNMP_TRANSPORT_FLAG_LISTEN;

        unaddr = &addr_pair->unix_socket_end;

        /* open a unix domain socket */
        /* XXX: get data from the transport def for it's location */
        unaddr->sun_family = AF_UNIX;
        if (NULL == sockpath) {
            sprintf(tmpsockpath, "%s/%s", get_persistent_directory(),
                    DEFAULT_SOCK_NAME);
            sockpath = tmpsockpath;
        }

        snprintf(unaddr->sun_path, sizeof(unaddr->sun_path), "%s", sockpath);
        snprintf(addr_pair->socket_path, sizeof(addr_pair->socket_path), "%s",
                 sockpath);

        t->sock = socket(PF_UNIX, SOCK_STREAM, 0);
        if (t->sock < 0) {
            netsnmp_transport_free(t);
            return NULL;
        }

        /* set the SO_PASSCRED option so we can receive the remote uid */
        {
            int one = 1;
            setsockopt(t->sock, SOL_SOCKET, SO_PASSCRED, (void *) &one,
                       sizeof(one));
        }

        unlink(unaddr->sun_path);
        rc = bind(t->sock, unaddr, SUN_LEN(unaddr));
        if (rc != 0) {
            DEBUGMSGTL(("netsnmp_ssh_transport",
                        "couldn't bind \"%s\", errno %d (%s)\n",
                        unaddr->sun_path, errno, strerror(errno)));
            netsnmp_ssh_close(t);
            netsnmp_transport_free(t);
            return NULL;
        }


        /* set the socket permissions */
        {
            /*
             * Apply any settings to the ownership/permissions of the
             * Sshdomain socket
             */
            int sshdomain_sock_perm =
                netsnmp_ds_get_int(NETSNMP_DS_LIBRARY_ID,
                                   NETSNMP_DS_SSHDOMAIN_SOCK_PERM);
            int sshdomain_sock_user =
                netsnmp_ds_get_int(NETSNMP_DS_LIBRARY_ID,
                                   NETSNMP_DS_SSHDOMAIN_SOCK_USER);
            int sshdomain_sock_group =
                netsnmp_ds_get_int(NETSNMP_DS_LIBRARY_ID,
                                   NETSNMP_DS_SSHDOMAIN_SOCK_GROUP);

            DEBUGMSGTL(("ssh", "here: %s, %d, %d, %d\n",
                        unaddr->sun_path,
                        sshdomain_sock_perm, sshdomain_sock_user,
                        sshdomain_sock_group));
            if (sshdomain_sock_perm != 0) {
                DEBUGMSGTL(("ssh", "Setting socket perms to %d\n",
                            sshdomain_sock_perm));
                chmod(unaddr->sun_path, sshdomain_sock_perm);
            }

            if (sshdomain_sock_user || sshdomain_sock_group) {
                /*
                 * If either of user or group haven't been set,
                 *  then leave them unchanged.
                 */
                if (sshdomain_sock_user == 0 )
                    sshdomain_sock_user = -1;
                if (sshdomain_sock_group == 0 )
                    sshdomain_sock_group = -1;
                DEBUGMSGTL(("ssh", "Setting socket user/group to %d/%d\n",
                            sshdomain_sock_user, sshdomain_sock_group));
                chown(unaddr->sun_path,
                      sshdomain_sock_user, sshdomain_sock_group);
            }
        }

        rc = listen(t->sock, NETSNMP_STREAM_QUEUE_LEN);
        if (rc != 0) {
            DEBUGMSGTL(("netsnmp_ssh_transport",
                        "couldn't listen to \"%s\", errno %d (%s)\n",
                        unaddr->sun_path, errno, strerror(errno)));
            netsnmp_ssh_close(t);
            netsnmp_transport_free(t);
            return NULL;
        }
        

#else /* we're called directly by sshd and use stdin/out */
        /* for ssh on the server side we've been launched so bind to
           stdin/out */

        /* nothing to do */

        /* XXX: verify we're inside ssh */
        t->sock = STDIN_FILENO;
#endif /* ! SNMPSSHDOMAIN_USE_EXTERNAL_PIPE */
#else /* NETSNMP_NO_LISTEN_SUPPORT */
        netsnmp_transport_free(t);
        return NULL;
#endif /* NETSNMP_NO_LISTEN_SUPPORT */
    } else {
        char *username;
        char *keyfilepub;
        char *keyfilepriv;
        
        /* use the requested user name */
        /* XXX: default to the current user name on the system like ssh does */
        username = netsnmp_ds_get_string(NETSNMP_DS_LIBRARY_ID,
                                         NETSNMP_DS_LIB_SSH_USERNAME);
        if (!username || 0 == *username) {
            snmp_log(LOG_ERR, "You must specify a ssh username to use.  See the snmp.conf manual page\n");
            netsnmp_transport_free(t);
            return NULL;
        }

        /* use the requested public key file */
        keyfilepub = netsnmp_ds_get_string(NETSNMP_DS_LIBRARY_ID,
                                           NETSNMP_DS_LIB_SSH_PUBKEY);
        if (!keyfilepub || 0 == *keyfilepub) {
            /* XXX: default to ~/.ssh/id_rsa.pub */
            snmp_log(LOG_ERR, "You must specify a ssh public key file to use.  See the snmp.conf manual page\n");
            netsnmp_transport_free(t);
            return NULL;
        }

        /* use the requested private key file */
        keyfilepriv = netsnmp_ds_get_string(NETSNMP_DS_LIBRARY_ID,
                                            NETSNMP_DS_LIB_SSH_PRIVKEY);
        if (!keyfilepriv || 0 == *keyfilepriv) {
            /* XXX: default to keyfilepub without the .pub suffix */
            snmp_log(LOG_ERR, "You must specify a ssh private key file to use.  See the snmp.conf manual page\n");
            netsnmp_transport_free(t);
            return NULL;
        }

        /* xxx: need an ipv6 friendly one too (sigh) */

        /* XXX: not ideal when structs don't actually match size wise */
        memcpy(&(addr_pair->remote_addr), addr, sizeof(struct sockaddr_in));

        t->sock = socket(PF_INET, SOCK_STREAM, 0);
        if (t->sock < 0) {
            netsnmp_transport_free(t);
            return NULL;
        }

        t->remote_length = sizeof(*addr);
        t->remote = netsnmp_memdup(addr, sizeof(*addr));
        if (!t->remote) {
            netsnmp_ssh_close(t);
            netsnmp_transport_free(t);
            return NULL;
        }

        /*
         * This is a client-type session, so attempt to connect to the far
         * end.  We don't go non-blocking here because it's not obvious what
         * you'd then do if you tried to do snmp_sends before the connection
         * had completed.  So this can block.
         */

        rc = connect(t->sock, addr, sizeof(struct sockaddr));

        if (rc < 0) {
            netsnmp_ssh_close(t);
            netsnmp_transport_free(t);
            return NULL;
        }

        /*
         * Allow user to override the send and receive buffers. Default is
         * to use os default.  Don't worry too much about errors --
         * just plough on regardless.  
         */
        netsnmp_sock_buffer_set(t->sock, SO_SNDBUF, local, 0);
        netsnmp_sock_buffer_set(t->sock, SO_RCVBUF, local, 0);

        /* open the SSH session and channel */
        addr_pair->session = libssh2_session_init();
        if (libssh2_session_startup(addr_pair->session, t->sock)) {
          shutdown:
            snmp_log(LOG_ERR, "Failed to establish an SSH session\n");
            netsnmp_ssh_close(t);
            netsnmp_transport_free(t);
            return NULL;
        }

        /* At this point we havn't authenticated, The first thing to
           do is check the hostkey's fingerprint against our known
           hosts Your app may have it hard coded, may go to a file,
           may present it to the user, that's your call
         */
        fingerprint =
            libssh2_hostkey_hash(addr_pair->session, LIBSSH2_HOSTKEY_HASH_MD5);
        DEBUGMSGTL(("ssh", "Fingerprint: "));
        for(i = 0; i < 16; i++) {
            DEBUGMSG(("ssh", "%02x",
                      (unsigned char)fingerprint[i]));
        }
        DEBUGMSG(("ssh", "\n"));

        /* check what authentication methods are available */
        userauthlist =
            libssh2_userauth_list(addr_pair->session,
                                  username, strlen(username));
        DEBUGMSG(("ssh", "Authentication methods: %s\n", userauthlist));

        /* XXX: allow other types */
        /* XXX: 4 seems magic to me... */
        if (strstr(userauthlist, "publickey") != NULL) {
            auth_pw |= 4;
        }

        /* XXX: hard coded paths and users */
        if (auth_pw & 4) {
            /* public key */
            if (libssh2_userauth_publickey_fromfile(addr_pair->session,
                                                    username,
                                                    keyfilepub, keyfilepriv,
                                                    NULL)) {
                snmp_log(LOG_ERR,"Authentication by public key failed!\n");
                goto shutdown;
            } else {
                DEBUGMSG(("ssh",
                          "\tAuthentication by public key succeeded.\n"));
            }
        } else {
            snmp_log(LOG_ERR,"Authentication by public key failed!\n");
            goto shutdown;
        }

        /* we've now authenticated both sides; contining onward ... */

        /* Request a channel */
        if (!(addr_pair->channel =
              libssh2_channel_open_session(addr_pair->session))) {
            snmp_log(LOG_ERR, "Unable to open a session\n");
            goto shutdown;
        }

        /* Request a terminal with 'vanilla' terminal emulation
         * See /etc/termcap for more options
         */
        /* XXX: needed?  doubt it */
/*         if (libssh2_channel_request_pty(addr_pair->channel, "vanilla")) { */
/*             snmp_log(LOG_ERR, "Failed requesting pty\n"); */
/*             goto shutdown; */
/*         } */
        if (libssh2_channel_subsystem(addr_pair->channel, "snmp")) {
            snmp_log(LOG_ERR, "Failed to request the ssh 'snmp' subsystem\n");
            goto shutdown;
        }
    }

    DEBUGMSG(("ssh","Opened connection.\n"));
    /*
     * Message size is not limited by this transport (hence msgMaxSize
     * is equal to the maximum legal size of an SNMP message).  
     */

    t->msgMaxSize = SNMP_MAX_PACKET_LEN;
    t->f_recv     = netsnmp_ssh_recv;
    t->f_send     = netsnmp_ssh_send;
    t->f_close    = netsnmp_ssh_close;
    t->f_accept   = netsnmp_ssh_accept;
    t->f_fmtaddr  = netsnmp_ssh_fmtaddr;

    return t;
}