Exemplo n.º 1
0
void
start_tcl(void)
{
    char *id = "start_tcl";
    char buf[BUFSIZ];
    int fd;
    int tot, len;

    interp = Tcl_CreateInterp();

    if (Tcl_Init(interp) == TCL_ERROR)
    {
        sprintf(log_buffer, "Tcl_Init error: %s",
                Tcl_GetStringResult(interp));
        log_err(-1, id, log_buffer);
        die(0);
    }

#if TCLX
#if TCL_MINOR_VERSION < 5  && TCL_MAJOR_VERSION < 8
    if (TclX_Init(interp) == TCL_ERROR)
    {
#else

    if (Tclx_Init(interp) == TCL_ERROR)
    {
#endif
        sprintf(log_buffer, "Tclx_Init error: %s",
                Tcl_GetStringResult(interp));
        log_err(-1, id, log_buffer);
        die(0);
    }

#endif
    add_cmds(interp);

    if (initfil)
    {
        int  code;

        code = Tcl_EvalFile(interp, initfil);

        if (code != TCL_OK)
        {
            char *trace;

            trace = (char *)Tcl_GetVar(interp, "errorInfo", 0);

            if (trace == NULL)
                trace = (char *)Tcl_GetStringResult(interp);

            fprintf(stderr, "%s: TCL error @ line %d: %s\n",
                    initfil, interp->errorLine, trace);

            sprintf(log_buffer, "%s: TCL error @ line %d: %s",
                    initfil, interp->errorLine,
                    Tcl_GetStringResult(interp));

            log_err(-1, id, log_buffer);

            die(0);
        }

        sprintf(log_buffer, "init file %s", initfil);

        log_record(PBSEVENT_SYSTEM, PBS_EVENTCLASS_SERVER,
                   id, log_buffer);
    }

    if ((fd = open(bodyfil, O_RDONLY)) == -1)
    {
        log_err(errno, id, bodyfil);
        die(0);
    }

    sprintf(log_buffer, "body file: %s", bodyfil);

    log_record(PBSEVENT_SYSTEM, PBS_EVENTCLASS_SERVER, id, log_buffer);

    if (body)
        free(body);

    if ((body = malloc(BUFSIZ)) == NULL)
    {
        log_err(errno, id, "malloc");
        die(0);
    }

    for (tot = 0; (len = read(fd, buf, sizeof(buf))) > 0; tot += len)
    {
        if ((body = realloc(body, tot + len + 1)) == NULL)
        {
            log_err(errno, id, "realloc");
            die(0);
        }

        memcpy(&body[tot], buf, len);
    }

    if (len == -1)
    {
        log_err(errno, id, bodyfil);
        die(0);
    }

    body[tot] = '\0';

    close(fd);

#if TCL_MAJOR_VERSION >= 8

    if (body_obj == NULL)
    {
        body_obj = Tcl_NewStringObj(body, tot);
        Tcl_IncrRefCount(body_obj);
    }
    else
    {
        Tcl_SetStringObj(body_obj, body, tot);
    }

#endif
}

int

addclient(name)
char *name;
{
    static char id[] = "addclient";

    struct hostent  *host, *gethostbyname();

    struct  in_addr saddr;

    if ((host = gethostbyname(name)) == NULL)
    {
        sprintf(log_buffer, "host %s not found", name);
        log_err(-1, id, log_buffer);
        return -1;
    }

    if (numclients >= START_CLIENTS)
    {
        pbs_net_t *newclients;

        newclients = realloc(okclients,
                             sizeof(pbs_net_t) * (numclients + 1));

        if (newclients == NULL)
            return -1;

        okclients = newclients;
    }

    memcpy((char *)&saddr, host->h_addr, host->h_length);

    okclients[numclients++] = saddr.s_addr;
    return 0;
}

/*
 * read_config - read and process the configuration file (see -c option)
 *
 * Currently, the only statement is $clienthost to specify which systems
 * can contact the scheduler.
 */
#define CONF_LINE_LEN 120

static
int
read_config(file)
char *file;
{
    static char *id = "read_config";
    FILE *conf;
    int i;
    char line[CONF_LINE_LEN];
    char *token;

    struct specialconfig
    {
        char *name;
        int (*handler)();
    } special[] =

    {
        {"clienthost", addclient },
        { NULL,  NULL }
    };


#if !defined(DEBUG) && !defined(NO_SECURITY_CHECK)

    if (chk_file_sec(file, 0, 0, S_IWGRP | S_IWOTH, 1, 0))
        return (-1);

#endif

    if ((conf = fopen(file, "r")) == NULL)
    {
        log_err(errno, id, "cannot open config file");
        return (-1);
    }

    while (fgets(line, CONF_LINE_LEN, conf))
    {

        if ((line[0] == '#') || (line[0] == '\n'))
            continue;  /* ignore comment & null line */
        else if (line[0] == '$')   /* special */
        {

            if ((token = strtok(line, " \t")) == NULL)
                token = "";

            for (i = 0; special[i].name; i++)
            {
                if (strcmp(token + 1, special[i].name) == 0)
                    break;
            }

            if (special[i].name == NULL)
            {
                sprintf(log_buffer, "config name %s not known",
                        token);
                log_record(PBSEVENT_ERROR,
                           PBS_EVENTCLASS_SERVER,
                           msg_daemonname, log_buffer);
                return (-1);
            }

            token = strtok(NULL, " \t");

            if (*(token + strlen(token) - 1) == '\n')
                *(token + strlen(token) - 1) = '\0';

            if (special[i].handler(token))
            {
                fclose(conf);
                return (-1);
            }

        }
        else
        {
            log_record(PBSEVENT_ERROR, PBS_EVENTCLASS_SERVER,
                       msg_daemonname,
                       "invalid line in config file");
            fclose(conf);
            return (-1);
        }
    }

    fclose(conf);

    return (0);
}

void
restart(sig)
int sig;
{
    char    *id = "restart";

    if (sig)
    {
        sprintf(log_buffer, "restart on signal %d", sig);
        log_close(1);
        log_open(logfile, path_log);
    }
    else
    {
        sprintf(log_buffer, "restart command");
    }

    log_record(PBSEVENT_SYSTEM, PBS_EVENTCLASS_SERVER, id, log_buffer);

    Tcl_DeleteInterp(interp);

    if (configfile)
    {
        if (read_config(configfile) != 0)
            die(0);
    }

    start_tcl();
}

void
badconn(msg)
char *msg;
{
    static char id[] = "badconn";

    struct in_addr addr;
    char  buf[5*sizeof(addr) + 100];

    struct hostent *phe;

    addr = saddr.sin_addr;
    phe = gethostbyaddr((void *) & addr, sizeof(addr), AF_INET);

    if (phe == NULL)
    {
        char hold[6];
        int i;
        union
        {

            struct in_addr aa;
            u_char  bb[sizeof(addr)];
        } uu;

        uu.aa = addr;
        sprintf(buf, "%u", uu.bb[0]);

        for (i = 1; i < (int)sizeof(addr); i++)
        {
            sprintf(hold, ".%u", uu.bb[i]);
            strcat(buf, hold);
        }
    }
    else
    {
        strncpy(buf, phe->h_name, sizeof(buf));
        buf[sizeof(buf)-1] = '\0';
    }

    sprintf(log_buffer, "%s on port %u %s", buf, ntohs(saddr.sin_port), msg);

    log_err(-1, id, log_buffer);
    return;
}

unsigned int
server_command()
{
    static char id[] = "server_command";
    int  new_socket;
    int  i;
    torque_socklen_t slen;
    unsigned int  cmd;
    pbs_net_t addr;

    slen = sizeof(saddr);
    new_socket = accept(server_sock,
                        (struct sockaddr *) & saddr, &slen);

    if (new_socket == -1)
    {
        log_err(errno, id, "accept");
        return SCH_ERROR;
    }

    if (ntohs(saddr.sin_port) >= IPPORT_RESERVED)
    {
        badconn("non-reserved port");
        close(new_socket);
        return SCH_ERROR;
    }

    addr = (pbs_net_t)saddr.sin_addr.s_addr;

    for (i = 0; i < numclients; i++)
    {
        if (addr == okclients[i])
            break;
    }

    if (i == numclients)
    {
        badconn("unauthorized host");
        close(new_socket);
        return SCH_ERROR;
    }

    if ((connector = socket_to_conn(new_socket)) < 0)
    {
        log_err(errno, id, "socket_to_conn");
        return SCH_ERROR;
    }

    if (get_4byte(new_socket, &cmd) != 1)
    {
        log_err(errno, id, "get4bytes");
        return SCH_ERROR;
    }

    return cmd;
}


/*
 * lock_out - lock out other daemons from this directory.
 */

static void lock_out(fds, op)
int fds;
int op;  /* F_WRLCK  or  F_UNLCK */
{

    struct flock flock;

    flock.l_type   = op;
    flock.l_whence = SEEK_SET;
    flock.l_start  = 0;
    flock.l_len    = 0; /* whole file */

    if (fcntl(fds, F_SETLK, &flock) < 0)
    {
        (void)strcpy(log_buffer, "pbs_sched: another scheduler running\n");
        log_err(errno, msg_daemonname, log_buffer);
        fprintf(stderr, log_buffer);
        exit(1);
    }
}

int main(argc, argv)
int  argc;
char *argv[];
{
    char  *id = "main";
    int  code;

    struct hostent *hp;
    int  go, c, errflg = 0;
    int  lockfds;
    int  t = 1;
    char  *ptr;
    pid_t  pid;
    char  *cp, host[100];
    char  *homedir = PBS_SERVER_HOME;
    unsigned int port;
    char  path_priv[_POSIX_PATH_MAX];
    char  *dbfile = "sched_out";
    int  alarm_time = 180;

    struct sigaction act;
    caddr_t  curr_brk = 0, next_brk;
    extern char *optarg;
    extern int optind, opterr;
    fd_set  fdset;

#ifndef DEBUG
    if (IamRoot() == 0)
    {
        return (1);
    }
#endif /* DEBUG */

    glob_argv = argv;

    if ((cp = strrchr(argv[0], '/')) == NULL)
        cp = argv[0];
    else
        cp++;

    msg_daemonname = strdup(cp);

    port = get_svrport(PBS_SCHEDULER_SERVICE_NAME, "tcp",
                       PBS_SCHEDULER_SERVICE_PORT);

    while ((c = getopt(argc, argv, "L:S:d:i:b:t:p:a:vc:")) != EOF)
    {
        switch (c)
        {

        case 'L':
            logfile = optarg;
            break;

        case 'S':
            port = (unsigned int)atoi(optarg);

            if (port == 0)
            {
                fprintf(stderr,
                        "%s: illegal port\n", optarg);
                errflg = 1;
            }

            break;

        case 'd':
            homedir = optarg;
            break;

        case 'i':  /* initialize */
            initfil = optarg;
            break;

        case 'b':
            bodyfil = optarg;
            break;

        case 't':
            termfil = optarg;
            break;

        case 'p':
            dbfile = optarg;
            break;

        case 'a':
            alarm_time = strtol(optarg, &ptr, 10);

            if (alarm_time <= 0 || *ptr != '\0')
            {
                fprintf(stderr,
                        "%s: bad alarm time\n", optarg);
                errflg = 1;
            }

            break;

        case 'c':
            configfile = optarg;
            break;

        case 'v':
            verbose = 1;
            break;

        case '?':
            errflg = 1;
            break;
        }
    }

    if (errflg || optind != argc)
    {
        static char *options[] =
        {
            "[-L logfile]",
            "[-S port]",
            "[-d home]",
            "[-i init]",
            "[-b body]",
            "[-t term]",
            "[-p output]",
            "[-a alarm]",
            "[-c configfile]",
            "[-v]",
            NULL
        };
        int i;

        fprintf(stderr, "usage: %s\n", argv[0]);

        for (i = 0; options[i]; i++)
            fprintf(stderr, "\t%s\n", options[i]);

        exit(1);
    }

    /* Save the original working directory for "restart" */
    if ((oldpath = getcwd((char *)NULL, MAXPATHLEN)) == NULL)
    {
        fprintf(stderr, "cannot get current working directory\n");
        exit(1);
    }

    (void)sprintf(path_priv, "%s/sched_priv", homedir);
#if !defined(DEBUG) && !defined(NO_SECURITY_CHECK)
    c  = chk_file_sec(path_priv, 1, 0, S_IWGRP | S_IWOTH, 1, 0);
    c |= chk_file_sec(PBS_ENVIRON, 0, 0, S_IWGRP | S_IWOTH, 0, 0);

    if (c != 0) exit(1);

#endif  /* not DEBUG and not NO_SECURITY_CHECK */
    if (chdir(path_priv) == -1)
    {
        perror(path_priv);
        exit(1);
    }

    (void)sprintf(path_log, "%s/sched_logs", homedir);
    (void)strcpy(pbs_current_user, "Scheduler");

    /* The following is code to reduce security risks                */
    /* start out with standard umask, system resource limit infinite */

    umask(022);

    if (setup_env(PBS_ENVIRON) == -1)
        exit(1);

    c = getgid();

    (void)setgroups(1, (gid_t *)&c); /* secure suppl. group ids */

    c = sysconf(_SC_OPEN_MAX);

    while (--c > 2)
        (void)close(c); /* close any file desc left open by parent */

#ifndef DEBUG
#ifdef _CRAY
    (void)limit(C_JOB,      0, L_CPROC, 0);

    (void)limit(C_JOB,      0, L_CPU,   0);

    (void)limit(C_JOBPROCS, 0, L_CPU,   0);

    (void)limit(C_PROC,     0, L_FD,  255);

    (void)limit(C_JOB,      0, L_FSBLK, 0);

    (void)limit(C_JOBPROCS, 0, L_FSBLK, 0);

    (void)limit(C_JOB,      0, L_MEM  , 0);

    (void)limit(C_JOBPROCS, 0, L_MEM  , 0);

#else /* not  _CRAY */
    {

        struct rlimit rlimit;

        rlimit.rlim_cur = RLIM_INFINITY;
        rlimit.rlim_max = RLIM_INFINITY;
        (void)setrlimit(RLIMIT_CPU,   &rlimit);
        (void)setrlimit(RLIMIT_FSIZE, &rlimit);
        (void)setrlimit(RLIMIT_DATA,  &rlimit);
        (void)setrlimit(RLIMIT_STACK, &rlimit);
#ifdef  RLIMIT_RSS
        (void)setrlimit(RLIMIT_RSS  , &rlimit);
#endif  /* RLIMIT_RSS */
#ifdef  RLIMIT_VMEM
        (void)setrlimit(RLIMIT_VMEM  , &rlimit);
#endif  /* RLIMIT_VMEM */
    }
#endif /* not _CRAY */

#if !defined(NO_SECURITY_CHECK)
    c = 0;

    if (initfil)
    {
        if (*initfil != '/')
        {
            (void)sprintf(log_buffer, "%s/%s", path_priv, initfil);
            c |= chk_file_sec(log_buffer, 0, 0, S_IWGRP | S_IWOTH, 1, 0);
        }
        else
        {
            c |= chk_file_sec(initfil, 0, 0, S_IWGRP | S_IWOTH, 1, 0);
        }
    }

    if (bodyfil)
    {
        if (*bodyfil != '/')
        {
            (void)sprintf(log_buffer, "%s/%s", path_priv, bodyfil);
            c |= chk_file_sec(log_buffer, 0, 0, S_IWGRP | S_IWOTH, 1, 0);
        }
        else
        {
            c |= chk_file_sec(bodyfil, 0, 0, S_IWGRP | S_IWOTH, 1, 0);
        }
    }

    if (termfil)
    {
        if (*termfil != '/')
        {
            (void)sprintf(log_buffer, "%s/%s", path_priv, termfil);
            c |= chk_file_sec(log_buffer, 0, 0, S_IWGRP | S_IWOTH, 1, 0);
        }
        else
        {
            c |= chk_file_sec(termfil, 0, 0, S_IWGRP | S_IWOTH, 1, 0);
        }
    }

    if (c) exit(1);

#endif /* not NO_SECURITY_CHECK */
#endif /* not DEBUG */

    if (log_open(logfile, path_log) == -1)
    {
        fprintf(stderr, "%s: logfile could not be opened\n", argv[0]);
        exit(1);
    }

    if (gethostname(host, sizeof(host)) == -1)
    {
        char *prob = "gethostname";

        log_err(errno, id, prob);
        perror(prob);
        die(0);
    }

    if ((hp = gethostbyname(host)) == NULL)
    {
        char *prob = "gethostbyname";

        log_err(errno, id, prob);
        perror(prob);
        die(0);
    }

    if ((server_sock = socket(AF_INET, SOCK_STREAM, 0)) < 0)
    {
        char *prob = "socket";

        log_err(errno, id, prob);
        perror(prob);
        die(0);
    }

    if (setsockopt(server_sock, SOL_SOCKET, SO_REUSEADDR,
                   (char *)&t, sizeof(t)) == -1)
    {
        char *prob = "setsockopt";

        log_err(errno, id, prob);
        perror(prob);
        die(0);
    }

    saddr.sin_family = AF_INET;

    saddr.sin_port = htons((unsigned short)port);
    memcpy(&saddr.sin_addr, hp->h_addr, hp->h_length);

    if (bind(server_sock, (struct sockaddr *)&saddr, sizeof(saddr)) < 0)
    {
        char *prob = "bind";

        log_err(errno, id, prob);
        perror(prob);
        die(0);
    }

    if (listen(server_sock, 5) < 0)
    {
        char *prob = "listen";

        log_err(errno, id, prob);
        perror(prob);
        die(0);
    }

    okclients = (pbs_net_t *)calloc(START_CLIENTS, sizeof(pbs_net_t));

    addclient("localhost");   /* who has permission to call MOM */
    addclient(host);

    if (configfile)
    {
        if (read_config(configfile) != 0)
            die(0);
    }

    lockfds = open("sched.lock", O_CREAT | O_TRUNC | O_WRONLY, 0644);

    if (lockfds < 0)
    {
        char *prob = "lock file";

        log_err(errno, id, prob);
        perror(prob);
        die(0);
    }

    lock_out(lockfds, F_WRLCK);

#ifndef DEBUG
    lock_out(lockfds, F_UNLCK);

    if ((pid = fork()) == -1)       /* error on fork */
    {
        char *prob = "fork";

        log_err(errno, id, prob);
        perror(prob);
        die(0);
    }
    else if (pid > 0)               /* parent exits */
        exit(0);

    if ((pid = setsid()) == -1)
    {
        log_err(errno, id, "setsid");
        die(0);
    }

    lock_out(lockfds, F_WRLCK);

    freopen(dbfile, "a", stdout);
    setvbuf(stdout, NULL, _IOLBF, 0);
    dup2(fileno(stdout), fileno(stderr));
#else
    pid = getpid();
    setvbuf(stdout, NULL, _IOLBF, 0);
    setvbuf(stderr, NULL, _IOLBF, 0);
#endif
    freopen("/dev/null", "r", stdin);

    /* write schedulers pid into lockfile */
    (void)sprintf(log_buffer, "%d\n", pid);
    (void)write(lockfds, log_buffer, strlen(log_buffer) + 1);

#if (PLOCK_DAEMONS & 2)
    (void)plock(PROCLOCK); /* lock daemon into memory */
#endif

    sprintf(log_buffer, "%s startup pid %d", argv[0], pid);
    log_record(PBSEVENT_SYSTEM, PBS_EVENTCLASS_SERVER, id, log_buffer);

    sprintf(log_buffer, "%s using TCL %s (%s)", argv[0],
            TCL_VERSION, TCL_PATCH_LEVEL);
    fprintf(stderr, "%s\n", log_buffer);
    log_record(PBSEVENT_SYSTEM, PBS_EVENTCLASS_SERVER, id, log_buffer);

    fullresp(0);
    sigemptyset(&allsigs);
    act.sa_flags = 0;
    sigaddset(&allsigs, SIGHUP);    /* remember to block these */
    sigaddset(&allsigs, SIGINT);    /* during critical sections */
    sigaddset(&allsigs, SIGTERM);   /* so we don't get confused */
    act.sa_mask = allsigs;

    act.sa_handler = restart;       /* do a restart on SIGHUP */
    sigaction(SIGHUP, &act, NULL);

    act.sa_handler = toolong; /* handle an alarm call */
    sigaction(SIGALRM, &act, NULL);

    act.sa_handler = die;           /* bite the biscuit for all following */
    sigaction(SIGINT, &act, NULL);
    sigaction(SIGTERM, &act, NULL);

    start_tcl();

    FD_ZERO(&fdset);

    for (go = 1; go;)
    {
        unsigned int cmd;


        FD_SET(server_sock, &fdset);

        if (select(FD_SETSIZE, &fdset, NULL, NULL, NULL) == -1)
        {
            if (errno != EINTR)
                log_err(errno, id, "select");

            continue;
        }

        if (!FD_ISSET(server_sock, &fdset))
            continue;

        cmd = server_command();

        if (cmd == (unsigned)SCH_ERROR || cmd == (unsigned)SCH_SCHEDULE_NULL)
            continue;

        if (sigprocmask(SIG_BLOCK, &allsigs, &oldsigs) == -1)
            log_err(errno, id, "sigprocmaskSIG_BLOCK)");

        if (verbose)
        {
            sprintf(log_buffer, "command %d", cmd);
            log_record(PBSEVENT_SYSTEM, PBS_EVENTCLASS_SERVER,
                       id, log_buffer);
        }

        switch (cmd)
        {

        case SCH_SCHEDULE_NEW:

        case SCH_SCHEDULE_TERM:

        case SCH_SCHEDULE_TIME:

        case SCH_SCHEDULE_RECYC:

        case SCH_SCHEDULE_CMD:

        case SCH_SCHEDULE_FIRST:
            alarm(alarm_time);

#if TCL_MAJOR_VERSION >= 8
            /* execute compiled body code for TCL-8 */
            code = Tcl_EvalObj(interp, body_obj);
#else
            code = Tcl_Eval(interp, body);
#endif
            alarm(0);

            switch (code)
            {

            case TCL_OK:

            case TCL_RETURN:
                break;

            default:
            {

                char *trace;
                char  codename[20];

                switch (code)
                {

                case TCL_BREAK:
                    strcpy(codename, "break");
                    break;

                case TCL_CONTINUE:
                    strcpy(codename, "continue");
                    break;

                default:
                    strcpy(codename, "<unknown>");
                    break;
                }

                trace = (char *)Tcl_GetVar(interp, "errorInfo", 0);

                if (trace == NULL)
                    trace = (char *)Tcl_GetStringResult(interp);

                fprintf(stderr, "%s: TCL interpreter return code %d (%s) @ line %d: %s\n",
                        bodyfil, code, codename,
                        interp->errorLine, trace);

                sprintf(log_buffer,
                        "%s: TCL error @ line %d: %s",
                        bodyfil, interp->errorLine,
                        Tcl_GetStringResult(interp));

                log_err(-1, id, log_buffer);

                die(0);
            }
            }

            break;

        case SCH_CONFIGURE:

        case SCH_RULESET:
            restart(0);
            break;

        case SCH_QUIT:
            go = 0;
            break;

        default:
            log_err(-1, id, "unknown command");
            break;
        }

        if (connector >= 0 && server_disconnect(connector))
        {
            log_err(errno, id, "server_disconnect");
            die(0);
        }

        connector = -1;

        if (verbose)
        {
            next_brk = (caddr_t)sbrk(0);

            if (next_brk > curr_brk)
            {
                sprintf(log_buffer, "brk point %p", next_brk);
                log_record(PBSEVENT_SYSTEM,
                           PBS_EVENTCLASS_SERVER,
                           id, log_buffer);
                curr_brk = next_brk;
            }
        }

        if (sigprocmask(SIG_SETMASK, &oldsigs, NULL) == -1)
            log_err(errno, id, "sigprocmask(SIG_SETMASK)");
    }

    if (termfil)
    {
        code = Tcl_EvalFile(interp, termfil);

        if (code != TCL_OK)
        {
            char *trace;

            trace = (char *)Tcl_GetVar(interp, "errorInfo", 0);

            if (trace == NULL)
                trace = (char *)Tcl_GetStringResult(interp);

            fprintf(stderr, "%s: TCL error @ line %d: %s\n",
                    termfil, interp->errorLine, trace);

            sprintf(log_buffer, "%s: TCL error @ line %d: %s",
                    termfil, interp->errorLine,
                    Tcl_GetStringResult(interp));

            log_err(-1, id, log_buffer);

            die(0);
        }

        sprintf(log_buffer, "term file: %s", termfil);

        log_record(PBSEVENT_SYSTEM, PBS_EVENTCLASS_SERVER,
                   id, log_buffer);
    }

    sprintf(log_buffer, "%s normal finish pid %d", argv[0], pid);

    log_record(PBSEVENT_SYSTEM, PBS_EVENTCLASS_SERVER, id, log_buffer);

    (void)close(server_sock);
    exit(0);
}
Exemplo n.º 2
0
int
server_command(void)

  {
  char *id = "server_command";

  int           new_socket;
  torque_socklen_t slen;
  int  i;
  unsigned int  cmd;
  pbs_net_t addr;

  slen = sizeof(saddr);

  new_socket = accept(server_sock, (struct sockaddr *) & saddr, &slen);

  if (new_socket == -1)
    {
    log_err(errno, id, "accept");

    return(SCH_ERROR);
    }

  addr = (pbs_net_t)saddr.sin_addr.s_addr;

  if (ntohs(saddr.sin_port) >= IPPORT_USERRESERVED+10000)
    {
    for (i = 0;i < mask_num;i++)
      {
      if (addr == maskclient[i])
        break;
      }

#if 0
    if (i == mask_num)
      {
      badconn("non-reserved port");

      close(new_socket);

      return(SCH_ERROR);
      }
#endif
    }
  else
    {
    for (i = 0;i < numclients;i++)
      {
      if (addr == okclients[i])
        break;
      }

    if (i == numclients)
      {
      badconn("unauthorized host");

      close(new_socket);

      return(SCH_ERROR);
      }
    }

  if ((connector = socket_to_conn(new_socket)) < 0)
    {
    log_err(errno, id, "socket_to_conn");

    return(SCH_ERROR);
    }

  if (get_4byte(new_socket, &cmd) != 1)
    {
    log_err(errno, id, "get4bytes");

    return(SCH_ERROR);
    }

  return((int)cmd);
  }