fcrondyn.c

/*
 * FCRON - periodic command scheduler 
 *
 *  Copyright 2000-2016 Thibault Godouet <fcron@free.fr>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 * 
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 * 
 *  The GNU General Public License can also be found in the file
 *  `LICENSE' that comes with the fcron source distribution.
 */


/* fcrondyn : interact dynamically with running fcron process :
 *     - list jobs, with their status, next time of execution, etc
 *     - run, delay a job
 *     - send a signal to a job
 *     - etc ...
 */

#include "fcrondyn.h"
#include "allow.h"
#include "read_string.h"
#include "mem.h"

#ifdef HAVE_LIBREADLINE
char **rl_cmpl_fcrondyn(const char *text, int start, int end);
char *rl_cmpl_command_generator(const char *text, int state);
#if defined(HAVE_READLINE_READLINE_H)
#include <readline/readline.h>
#elif defined(HAVE_READLINE_H)
#include <readline.h>
#endif                          /* !defined(HAVE_READLINE_H) */
#if defined(HAVE_READLINE_HISTORY_H)
#include <readline/history.h>
#elif defined(HAVE_HISTORY_H)
#include <history.h>
#endif                          /* defined(HAVE_READLINE_HISTORY_H) */
#endif                          /* HAVE_LIBREADLINE */

void info(void);
void usage(void);
void xexit(int exit_val);
RETSIGTYPE sigpipe_handler(int x);
int interactive_mode(int fd);
/* returned by parse_cmd() and/or talk_fcron() */
#define QUIT_CMD 1
#define HELP_CMD 2
#define ZEROLEN_CMD 3
#define CMD_NOT_FOUND 4
#define INVALID_ARG 5
int talk_fcron(char *cmd_str, int fd);
int parse_cmd(char *cmd_str, long int **cmd, int *cmd_len);
int connect_fcron(void);
int authenticate_user_password(int fd);

/* command line options */
char *cmd_str = NULL;

/* needed by log part : */
char *prog_name = NULL;
char foreground = 1;
pid_t daemon_pid = 0;

/* uid/gid of user/group root 
 * (we don't use the static UID or GID as we ask for user and group names
 * in the configure script) */
uid_t rootuid = 0;
gid_t rootgid = 0;

/* misc */
char *user_str = NULL;
uid_t user_uid = 0;
gid_t user_gid = 0;

struct cmd_list_ent cmd_list[] = {
    /* name, desc, num opt, cmd code, cmd opts, cmd defaults */
    {"ls", {NULL}, "List all jobs of user", 1, CMD_LIST_JOBS,
     {USER}, {CUR_USER}},
    {"ls_lavgq", {}, "List jobs of user which are in lavg queue", 1,
     CMD_LIST_LAVGQ, {USER}, {CUR_USER}},
    {"ls_serialq", {}, "List jobs of user which are in serial queue",
     1, CMD_LIST_SERIALQ, {USER}, {CUR_USER}},
    {"ls_exeq", {}, "List running jobs of user", 1, CMD_LIST_EXEQ,
     {USER}, {CUR_USER}},
    {"detail", {}, "Print details on job", 1, CMD_DETAILS,
     {JOBID}, {ARG_REQUIRED}},
/*    {"reschedule", {NULL}, "Reschedule next execution of job", 2,
      CMD_RESCHEDULE, {TIME_AND_DATE, JOBID}, {ARG_REQUIRED, ARG_REQUIRED}}, */
    {"runnow", {}, "Advance next execution of job to now", 1, CMD_RUNNOW,
     {JOBID}, {ARG_REQUIRED}},
    {"run", {}, "Run job now (without changing its current schedule)", 1,
     CMD_RUN, {JOBID}, {ARG_REQUIRED}},
    {"kill", {}, "Send signal to running job", 2, CMD_SEND_SIGNAL,
     {SIGNAL, JOBID}, {ARG_REQUIRED, ARG_REQUIRED}},
    {"renice", {}, "Renice running job", 2, CMD_RENICE,
     {NICE_VALUE, JOBID}, {ARG_REQUIRED, ARG_REQUIRED}},
    {"quit", {"q", "exit"}, "Quit fcrondyn", 0, QUIT_CMD, {}, {}},
    {"help", {"h"}, "Display a help message", 0, HELP_CMD, {}, {}},
};

const int cmd_list_len = sizeof(cmd_list) / sizeof(cmd_list_ent);

void
info(void)
    /* print some informations about this program :
     * version, license */
{
    fprintf(stderr,
            "fcrondyn " VERSION_QUOTED
            " - interact dynamically with daemon fcron\n" "Copyright "
            COPYRIGHT_QUOTED " Thibault Godouet <fcron@free.fr>\n"
            "This program is free software distributed WITHOUT ANY WARRANTY.\n"
            "See the GNU General Public License for more details.\n");

    exit(EXIT_OK);

}


void
usage(void)
  /*  print a help message about command line options and exit */
{
    fprintf(stderr,
            "fcrondyn [-i]\n"
            "fcrondyn -x {command}\n"
            "fcrondyn -h\n"
            "  -i         run fcrontab in interactive mode.\n"
            "  -x         execute one command (in batch mode)\n"
            "  -c f       make fcrontab use config file f.\n"
            "  -d         set up debug mode.\n"
            "  -h         display this help message.\n"
            "  -V         display version & infos about fcrondyn.\n" "\n"
            "To list the available commands, run:\n" "  fcrondyn -x help\n");

    exit(EXIT_ERR);
}

RETSIGTYPE
sigpipe_handler(int x)
    /* handle broken pipes ... */
{
    fprintf(stderr,
            "Broken pipe : fcron may have closed the connection\nThe connection "
            "has been idle for more than %ds, or fcron may not be running anymore.\n",
            MAX_IDLE_TIME);
    fprintf(stderr, "Exiting ...\n");

    xexit(EXIT_ERR);
}

void
xexit(int exit_val)
    /* clean & exit */
{
    Free_safe(cmd_str);

    exit(exit_val);
}


/* used in parse_cmd : */
#define Write_cmd(DATA) \
	  memcpy(buf + *cmd_len, &DATA, sizeof(long int)); \
	  *cmd_len += 1;

#define Strncmp(STR1, STR2, STR1_SIZE) \
          strncmp(STR1, STR2, (STR1_SIZE < strlen(STR2)) ? strlen(STR2) : STR1_SIZE)

int
parse_cmd(char *cmd_str, long int **cmd, int *cmd_len)
    /* read a command string, check if it is valid and translate it */
{
    long int buf[SOCKET_MSG_LEN];
    int word_size = 0;
    int i = 0, j = 0, rank = -1;
    long int int_buf = 0;
    struct passwd *pass = NULL;
#ifdef SYSFCRONTAB
    long int sysfcrontab_uid = SYSFCRONTAB_UID;
#endif

    bzero(buf, sizeof(buf));
    *cmd_len = 0;
    remove_blanks(cmd_str);     /* at the end of the string */

    if ((word_size = get_word(&cmd_str)) == 0) {
        fprintf(stderr, "Warning : Zero-length command name : line ignored.\n");
        return ZEROLEN_CMD;
    }

    for (i = 0; i < cmd_list_len; i++) {
        int j;
        if (Strncmp(cmd_str, cmd_list[i].cmd_name, word_size) == 0) {
            rank = i;
            break;
        }
        for (j = 0; j < MAX_NUM_ALIAS && cmd_list[i].cmd_alias[j] != NULL; j++) {
            if (Strncmp(cmd_str, cmd_list[i].cmd_alias[j], word_size) == 0) {
                rank = i;
                break;
            }
        }
    }
    if (rank == (-1)) {
        fprintf(stderr, "Error : Unknown command.\n");
        return CMD_NOT_FOUND;
    }
    else if (cmd_list[rank].cmd_code == QUIT_CMD) {
        if (debug_opt)
            fprintf(stderr, "quit command\n");
        return QUIT_CMD;
    }
    else if (cmd_list[rank].cmd_code == HELP_CMD) {
        if (debug_opt)
            fprintf(stderr, "Help command\n");
        return HELP_CMD;
    }

    Write_cmd(cmd_list[rank].cmd_code);

    if (debug_opt)
        fprintf(stderr, "command : %s\n", cmd_list[i].cmd_name);

    cmd_str += word_size;
    for (i = 0; i < cmd_list[rank].cmd_numopt; i++) {

        if ((word_size = get_word(&cmd_str)) == 0) {

            if (cmd_list[rank].cmd_default[i] == ARG_REQUIRED) {
                fprintf(stderr, "Error : arg required !\n");
                return INVALID_ARG;
            }

            /* use default value : currently, works only with CUR_USER */
            if (user_uid == rootuid) {
                /* default for root = all */
                int_buf = ALL;
                Write_cmd(int_buf);
                if (debug_opt)
                    fprintf(stderr, "  uid = ALL\n");
            }
            else {
                Write_cmd(user_uid);
                if (debug_opt)
                    fprintf(stderr, "  uid = %d\n", (int)user_uid);
            }

        }

        else {

            /* get value from line ... */
            switch (cmd_list[rank].cmd_opt[i]) {

            case USER:
                int_buf = (long int)*(cmd_str + word_size);
                *(cmd_str + word_size) = '\0';
#ifdef SYSFCRONTAB
                if (strcmp(cmd_str, SYSFCRONTAB) == 0) {
                    Write_cmd(sysfcrontab_uid);
                }
                else {
#endif
                    if ((pass = getpwnam(cmd_str)) == NULL) {
                        fprintf(stderr,
                                "Error : '%s' isn't a valid username.\n",
                                cmd_str);
                        return INVALID_ARG;
                    }
                    Write_cmd(pass->pw_uid);
#ifdef SYSFCRONTAB
                }
#endif
                *(cmd_str + word_size) = (char)int_buf;
                cmd_str += word_size;
                if (debug_opt)
                    fprintf(stderr, "  uid = %d\n",
#ifdef SYSFCRONTAB
                            (pass) ? (int)pass->pw_uid : (int)SYSFCRONTAB_UID
#else
                            (int)pass->pw_uid
#endif
                        );
                break;

            case JOBID:
                /* after strtol(), cmd_str will be updated (first non-number char) */
                if ((int_buf = strtol(cmd_str, &cmd_str, 10)) < 0
                    || int_buf >= LONG_MAX || (!isspace((int)*cmd_str)
                                               && *cmd_str != '\0')) {
                    fprintf(stderr, "Error : invalid jobid.\n");
                    return INVALID_ARG;
                }
                Write_cmd(int_buf);
                if (debug_opt)
                    fprintf(stderr, "  jobid = %ld\n", int_buf);
                break;

            case TIME_AND_DATE:
                /* argghh !!! no standard function ! */
                break;

            case NICE_VALUE:
                /* after strtol(), cmd_str will be updated (first non-number char) */
                if ((int_buf = strtol(cmd_str, &cmd_str, 10)) > 20
                    || (int_buf < 0 && getuid() != rootuid) || int_buf < -20
                    || (!isspace((int)*cmd_str) && *cmd_str != '\0')) {
                    fprintf(stderr, "Error : invalid nice value.\n");
                    return INVALID_ARG;
                }
                Write_cmd(int_buf);
                if (debug_opt)
                    fprintf(stderr, "  nicevalue = %ld\n", int_buf);
                break;

            case SIGNAL:
                if (isalpha((int)*cmd_str)) {
                    for (j = 0; j < word_size; j++)
                        *(cmd_str + j) = tolower(*(cmd_str + j));
                    if (Strncmp(cmd_str, "hup", word_size) == 0)
                        int_buf = SIGHUP;
                    else if (Strncmp(cmd_str, "int", word_size) == 0)
                        int_buf = SIGINT;
                    else if (Strncmp(cmd_str, "quit", word_size) == 0)
                        int_buf = SIGQUIT;
                    else if (Strncmp(cmd_str, "kill", word_size) == 0)
                        int_buf = SIGKILL;
                    else if (Strncmp(cmd_str, "alrm", word_size) == 0)
                        int_buf = SIGALRM;
                    else if (Strncmp(cmd_str, "term", word_size) == 0)
                        int_buf = SIGTERM;
                    else if (Strncmp(cmd_str, "usr1", word_size) == 0)
                        int_buf = SIGUSR1;
                    else if (Strncmp(cmd_str, "usr2", word_size) == 0)
                        int_buf = SIGUSR2;
                    else if (Strncmp(cmd_str, "cont", word_size) == 0)
                        int_buf = SIGCONT;
                    else if (Strncmp(cmd_str, "stop", word_size) == 0)
                        int_buf = SIGSTOP;
                    else if (Strncmp(cmd_str, "tstp", word_size) == 0)
                        int_buf = SIGTSTP;
                    else {
                        fprintf(stderr,
                                "Error : unknow signal (try integer value)\n");
                        return INVALID_ARG;
                    }
                    cmd_str += word_size;
                }
                /* after strtol(), cmd_str will be updated (first non-number char) */
                else if ((int_buf = strtol(cmd_str, &cmd_str, 10)) <= 0
                         || int_buf >= LONG_MAX || (!isspace((int)*cmd_str)
                                                    && *cmd_str != '\0')) {
                    fprintf(stderr, "Error : invalid signal value.\n");
                    return INVALID_ARG;
                }
                Write_cmd(int_buf);
                if (debug_opt)
                    fprintf(stderr, "  signal = %ld\n", int_buf);
                break;

            default:
                fprintf(stderr, "Error : Unknown arg !");
                return INVALID_ARG;
            }
        }
    }

    Skip_blanks(cmd_str);
    if (*cmd_str != '\0')
        fprintf(stderr, "Warning : too much arguments : '%s' ignored.\n",
                cmd_str);

    /* This is a valid command ... */
    *cmd = alloc_safe(*cmd_len * sizeof(long int), "command string");
    memcpy(*cmd, buf, *cmd_len * sizeof(long int));

    return OK;
}

int
authenticate_user_password(int fd)
    /* authenticate user */
{
    char *password = NULL;
    char buf[USER_NAME_LEN + 16];
    int len = 0;
    fd_set read_set;            /* needed to use select to check if some data is waiting */
    struct timeval tv;

    snprintf(buf, sizeof(buf), "password for %s :", user_str);
    if ((password = read_string(CONV_ECHO_OFF, buf)) == NULL)
        return ERR;

    len = snprintf(buf, sizeof(buf), "%s", user_str) + 1;
    len += snprintf(buf + len, sizeof(buf) - len, "%s", password) + 1;
    send(fd, buf, len, 0);
    Overwrite(buf);
    Overwrite(password);
    Free_safe(password);

    tv.tv_sec = MAX_WAIT_TIME;
    tv.tv_usec = 0;
    FD_ZERO(&read_set);
    FD_SET(fd, &read_set);
    if (select(fd + 1, &read_set, NULL, NULL, &tv) <= 0) {
        error_e("Couldn't get data from socket during %d seconds.",
                MAX_WAIT_TIME);
        return ERR;
    }
    while (recv(fd, buf, sizeof(buf), 0) < 0 && errno == EINTR)
        if (errno == EINTR && debug_opt)
            fprintf(stderr, "Got EINTR ...");
    if (strncmp(buf, "1", sizeof("1")) != 0)
        return ERR;

    return OK;
}


int
connect_fcron(void)
    /* connect to fcron through a socket, and identify user */
{
    int fd = -1;
    struct sockaddr_un addr;
    int len = 0;
    int sun_len = 0;

    if ((fd = socket(PF_UNIX, SOCK_STREAM, 0)) == -1)
        die_e("could not create socket");

    addr.sun_family = AF_UNIX;
    len = strlen(fifofile);
    if (len > sizeof(addr.sun_path) - 1)
        die("Error : fifo file path too long (max is %d)",
            sizeof(addr.sun_path) - 1);
    /* length(fifofile) < sizeof(add.sun_path), so strncpy will terminate
     * the string with at least one \0 (not necessarily required by the OS,
     * but still a good idea) */
    strncpy(addr.sun_path, fifofile, sizeof(addr.sun_path));
    addr.sun_path[sizeof(addr.sun_path) - 1] = '\0';
    sun_len = (addr.sun_path - (char *)&addr) + len;
#if HAVE_SA_LEN
    addr.sun_len = sun_len;
#endif

    if (connect(fd, (struct sockaddr *)&addr, sun_len) < 0)
        die_e("Cannot connect() to fcron (check if fcron is running)");

/* Nothing to do on the client side if we use SO_PASSCRED */
#if !defined(SO_PASSCRED) && !defined(HAVE_GETPEERUCRED) && !defined(HAVE_GETPEEREID)
    if (authenticate_user_password(fd) == ERR) {
        fprintf(stderr, "Invalid password or too many authentication failures"
                " (try to connect later).\n(In the later case, fcron rejects all"
                " new authentication during %d secs)\n", AUTH_WAIT);
        die("Unable to authenticate user");
    }
#endif                          /* SO_PASSCRED HAVE_GETPEERUCRED HAVE_GETPEEREID */

    return fd;

}

int
talk_fcron(char *cmd_str, int fd)
    /* read a string command, check if it is valid and translate it,
     * send it to fcron, and print its answer */
{
    long int *cmd = NULL;
    int cmd_len = 0;
    char buf[LINE_LEN];
    ssize_t read_len = 0;
    char existing_connection = (fd < 0) ? 0 : 1;
    fd_set read_set;            /* needed to use select to check if some data is waiting */
    struct timeval tv;

    switch (parse_cmd(cmd_str, &cmd, &cmd_len)) {
    case OK:
        break;
    case HELP_CMD:
        {
            int i, j, len;
            printf("Command recognized by fcrondyn :\n");
            printf("------------------------------\n");
            for (i = 0; i < cmd_list_len; i++) {
                len = printf("%s ", cmd_list[i].cmd_name);

                /* print args : */
                for (j = 0; j < cmd_list[i].cmd_numopt; j++) {
                    if (cmd_list[i].cmd_default[j] != ARG_REQUIRED)
                        len += printf("[");
                    switch (cmd_list[i].cmd_opt[j]) {
                    case USER:
                        len += printf("user");
                        break;
                    case JOBID:
                        len += printf("jobid");
                        break;
                    case TIME_AND_DATE:
                        len += printf("time");
                        break;
                    case NICE_VALUE:
                        len += printf("niceval");
                        break;
                    case SIGNAL:
                        len += printf("sig");
                        break;
                    case BOOLEAN:
                        len += printf("bool");
                        break;
                    default:
                        len += printf("unknown_arg!");
                    }
                    if (cmd_list[i].cmd_default[j] != ARG_REQUIRED)
                        len += printf("]");
                    len += printf(" ");
                }
                /* Align correctly the descriptions : */
                printf("%*s%s", 24 - len, "", cmd_list[i].cmd_desc);

                /* print alias list (if any) */
                if (cmd_list[i].cmd_alias[0] != NULL) {
                    printf(" (aliases:");
                    for (j = 0;
                         j < MAX_NUM_ALIAS && cmd_list[i].cmd_alias[j] != NULL;
                         j++) {
                        printf(" %s", cmd_list[i].cmd_alias[j]);
                    }
                    printf(")");
                }

                printf("\n");
            }
        }
        return HELP_CMD;
    case QUIT_CMD:
        return QUIT_CMD;
    case CMD_NOT_FOUND:
        return CMD_NOT_FOUND;
    case INVALID_ARG:
        return INVALID_ARG;
    case ZEROLEN_CMD:
        return ZEROLEN_CMD;
    default:
        return ERR;
    }

    /* This is a valid command (so we'll have to free() it) ... */

    if (!existing_connection && (fd = connect_fcron()) == ERR)
        return ERR;

    send(fd, cmd, cmd_len * sizeof(long int), 0);
    Free_safe(cmd);
    cmd_len = 0;

    tv.tv_sec = MAX_WAIT_TIME;
    tv.tv_usec = 0;
    FD_ZERO(&read_set);
    FD_SET(fd, &read_set);
    if (select(fd + 1, &read_set, NULL, NULL, &tv) <= 0) {
        error_e("Couldn't get data from socket during %d seconds.",
                MAX_WAIT_TIME);
        return ERR;
    }


    while ((read_len = recv(fd, buf, sizeof(buf) - 1, 0)) >= 0
           || errno == EINTR) {

        if (errno == EINTR && debug_opt)
            fprintf(stderr, "got EINTR ...\n");
        else if (read_len > sizeof(buf)) {
            /* weird ... no data yet ? */
            if (debug_opt)
                fprintf(stderr, "no data yet ?");
        }
        else if (read_len <= 0) {
            if (debug_opt)
                fprintf(stderr, "read_len = %d\n", (int)read_len);
            fprintf(stderr, "connection closed by fcron\n");
            shutdown(fd, SHUT_RDWR);
            return ERR;
        }
        else {
            /* ensure the string is terminated by a '\0' for when we'll printf() it */
            buf[read_len] = '\0';
            printf("%s", buf);

            /* check for the end of command output marker */
            if (read_len >= sizeof(END_STR) &&
                strncmp(&buf[read_len - sizeof(END_STR)], END_STR,
                        sizeof(END_STR)) == 0)
                break;
        }
    }
    if (read_len < 0) {
        error_e("error in recv()");
    }

    if (!existing_connection)
        xclose_check(&fd, "unix socket");

    return OK;
}

#ifdef HAVE_LIBREADLINE
/* Attempt to complete on the contents of TEXT. START and END bound the
   region of rl_line_buffer that contains the word to complete. TEXT is
   the word to complete. We can use the entire contents of rl_line_buffer
   in case we want to do some simple parsing. Return the array of matches,
   or NULL if there aren't any. */
char **
rl_cmpl_fcrondyn(const char *text, int start, int end)
{
    char **matches;

    matches = (char **)NULL;

    /* If this word is at the start of the line, then it is a command
     * to complete. Otherwise it is an argument which we ignore for now */
    if (start == 0) {
        matches = rl_completion_matches(text, rl_cmpl_command_generator);
    }

    return (matches);
}

/* Generator function for command completion. STATE lets us know whether
   to start from scratch; without any state (i.e. STATE == 0), then we
   start at the top of the list. */
char *
rl_cmpl_command_generator(const char *text, int state)
{
    static int list_index, len;
    char *name = NULL;

    /* If this is a new word to complete, initialize now.  This includes
     * saving the length of TEXT for efficiency, and initializing the index
     * variable to 0. */
    if (!state) {
        list_index = 0;
        len = strlen(text);
    }

    /* Return the next name which partially matches from the command list. */
    while (list_index < cmd_list_len) {
        name = cmd_list[list_index].cmd_name;
        list_index++;
        if (strncmp(name, text, len) == 0) {
            return (strdup2(name));
        }
    }

    /* If no names matched, then return NULL. */
    return ((char *)NULL);
}
#endif                          /* HAVE_LIBREADLINE */

int
interactive_mode(int fd)
    /* provide user a prompt, read command, send it to fcron, print its answer,
     * then give another prompt, etc, until user type an exit command */
{
    char existing_connection = (fd < 0) ? 0 : 1;
    int return_code = 0;
#ifdef HAVE_LIBREADLINE
    char *line_read = NULL;
#else                           /* HAVE_LIBREADLINE */
    char buf[LINE_LEN];
#endif                          /* HAVE_LIBREADLINE */

    if (!existing_connection && (fd = connect_fcron()) == ERR)
        return ERR;

#ifdef HAVE_LIBREADLINE
    /* Allow conditional parsing of the ~/.inputrc file. */
    rl_readline_name = "fcrondyn";

    /* Tell the completer that we want a crack first. */
    rl_attempted_completion_function = rl_cmpl_fcrondyn;

    while (1) {
        line_read = readline("fcrondyn> ");

        if (line_read == NULL) {
            /* Handle EOF gracefully and move past the prompt line */
            printf("\n");
            break;
        }

        return_code = talk_fcron(line_read, fd);

#ifdef HAVE_READLINE_HISTORY
        if (line_read && *line_read) {
            add_history(line_read);
        }
#endif                          /* HAVE_READLINE_HISTORY */

        free(line_read);
        if (return_code == QUIT_CMD || return_code == ERR) {
            break;
        }
    }
#else                           /* HAVE_LIBREADLINE */
    while (fprintf(stderr, "fcrondyn> ")
           && fgets(buf, sizeof(buf), stdin) != NULL
           && (return_code = talk_fcron(buf, fd)) != QUIT_CMD
           && return_code != ERR) ;
#endif                          /* HAVE_LIBREADLINE */

    if (!existing_connection)
        xclose_check(&fd, "unix socket");

    return OK;
}


void
parseopt(int argc, char *argv[])
  /* set options */
{

    int c, i;
    extern char *optarg;
    extern int optind, opterr, optopt;

    /* constants and variables defined by command line */

    while (1) {
        c = getopt(argc, argv, "hVdc:ix:");
        if (c == EOF)
            break;
        switch (c) {

        case 'V':
            info();
            break;

        case 'h':
            usage();
            break;

        case 'd':
            debug_opt = 1;
            break;

        case 'c':
            Set(fcronconf, optarg);
            break;

        case 'i':
            Free_safe(cmd_str);
            break;

        case 'x':
            Set(cmd_str, optarg);
            break;

        case ':':
            fprintf(stderr, "(setopt) Missing parameter.\n");
            usage();

        case '?':
            usage();

        default:
            fprintf(stderr, "(setopt) Warning: getopt returned %c.\n", c);
        }

    }

    if (optind < argc) {
        for (i = optind; i <= argc; i++)
            fprintf(stderr, "Unknown argument \"%s\"", argv[i]);
        usage();
    }
}


int
main(int argc, char **argv)
{
    int return_code = 0;
    int fd = (-1);              /* fd == -1 means connection to fcron is not currently open */
    struct passwd *pass = NULL;

    rootuid = get_user_uid_safe(ROOTNAME);
    rootgid = get_group_gid_safe(ROOTGROUP);

    if (strrchr(argv[0], '/') == NULL)
        prog_name = argv[0];
    else
        prog_name = strrchr(argv[0], '/') + 1;

    user_uid = getuid();
    user_gid = getgid();
    if ((pass = getpwuid(user_uid)) == NULL)
        die("user \"%s\" is not in passwd file. Aborting.", USERNAME);
    user_str = strdup2(pass->pw_name);

    /* drop suid rights that we don't need, but keep the sgid rights
     * for now as we will need them for read_conf() and is_allowed() */
#ifdef USE_SETE_ID
    seteuid_safe(user_uid);
#endif
    if (setuid(user_uid) < 0)
        die_e("could not setuid() to %d", user_uid);

    /* interpret command line options */
    parseopt(argc, argv);

    /* read fcron.conf and update global parameters */
    read_conf();

    if (!is_allowed(user_str)) {
        die("User \"%s\" is not allowed to use %s. Aborting.", user_str,
            prog_name);
    }

    /* we don't need anymore special rights : drop remaining ones */
#ifdef USE_SETE_ID
    setegid_safe(user_gid);
#endif
    if (setgid(user_gid) < 0)
        die_e("could not setgid() to %d", user_gid);

    /* check for broken pipes ... */
    signal(SIGPIPE, sigpipe_handler);

    if (cmd_str == NULL)
        return_code = interactive_mode(fd);
    else
        return_code = talk_fcron(cmd_str, fd);

    xexit((return_code == OK) ? EXIT_OK : EXIT_ERR);

    /* never reached */
    return EXIT_OK;

}