ndmpd/ndmp/ndmpd_main.c

	ndmpd_main.c revision 2654012f83cec5dc15b61dfe3e4a4915f186e7a6
/*
 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*
 * BSD 3 Clause License
 *
 * Copyright (c) 2007, The Storage Networking Industry Association.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *  - Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 *  - Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 *  - Neither the name of The Storage Networking Industry Association (SNIA)
 *    nor the names of its contributors may be used to endorse or promote
 *    products derived from this software without specific prior written
 *    permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */
/* Copyright (c) 1996, 1997 PDC, Network Appliance. All Rights Reserved */

#include <errno.h>
#include <signal.h>
#include <libgen.h>
#include <libscf.h>
#include <libintl.h>
#include <sys/wait.h>
#include <zone.h>
#include <tsol/label.h>
#include <dlfcn.h>
#include "ndmpd.h"
#include "ndmpd_common.h"


/* zfs library handle & mutex */
libzfs_handle_t *zlibh;
mutex_t zlib_mtx;
void *mod_plp;

static void ndmpd_sig_handler(int sig);

typedef struct ndmpd {
    int s_shutdown_flag;    /* Fields for shutdown control */
    int s_sigval;
} ndmpd_t;

ndmpd_t ndmpd;


/*
 * Load and initialize the plug-in module
 */
static int
mod_init()
{
    char *plname;
    ndmp_plugin_t *(*plugin_init)(int);

    ndmp_pl = NULL;
    if ((plname = ndmpd_get_prop(NDMP_PLUGIN_PATH)) == NULL)
        return (0);

    if ((mod_plp = dlopen(plname, RTLD_LOCAL | RTLD_NOW)) == NULL) {
        syslog(LOG_ERR, "Error loading the plug-in %s", plname);
        return (0);
    }

    plugin_init = (ndmp_plugin_t *(*)(int))dlsym(mod_plp, "_ndmp_init");
    if (plugin_init == NULL) {
        (void) dlclose(mod_plp);
        return (0);
    }
    if ((ndmp_pl = plugin_init(NDMP_PLUGIN_VERSION)) == NULL) {
        syslog(LOG_ERR, "Error loading the plug-in %s", plname);
        return (-1);
    }
    return (0);
}

/*
 * Unload
 */
static void
mod_fini()
{
    if (ndmp_pl == NULL)
        return;

    void (*plugin_fini)(ndmp_plugin_t *);

    plugin_fini = (void (*)(ndmp_plugin_t *))dlsym(mod_plp, "_ndmp_fini");
    if (plugin_fini == NULL) {
        (void) dlclose(mod_plp);
        return;
    }
    plugin_fini(ndmp_pl);
    (void) dlclose(mod_plp);
}

static void
daemonize_init(char *arg)
{
    sigset_t set, oset;
    pid_t pid;

    /*
     * Set effective sets privileges to 'least' required. If fails, send
     * error messages to log file and proceed.
     */
    if (priv_set(PRIV_SET, PRIV_EFFECTIVE,
        PRIV_FILE_LINK_ANY, PRIV_PROC_INFO, PRIV_PROC_SESSION,
        PRIV_PROC_FORK, PRIV_PROC_EXEC,
        PRIV_PROC_AUDIT, PRIV_PROC_SETID, PRIV_PROC_OWNER, PRIV_FILE_CHOWN,
        PRIV_FILE_CHOWN_SELF, PRIV_FILE_DAC_READ, PRIV_FILE_DAC_SEARCH,
        PRIV_FILE_DAC_WRITE, PRIV_FILE_OWNER, PRIV_FILE_SETID,
        PRIV_SYS_LINKDIR, PRIV_SYS_DEVICES, PRIV_SYS_MOUNT, PRIV_SYS_CONFIG,
        NULL))
        syslog(LOG_ERR,
            "Failed to set least required privileges to the service.");

    /*
     * Block all signals prior to the fork and leave them blocked in the
     * parent so we don't get in a situation where the parent gets SIGINT
     * and returns non-zero exit status and the child is actually running.
     * In the child, restore the signal mask once we've done our setsid().
     */
    (void) sigfillset(&set);
    (void) sigdelset(&set, SIGABRT);
    (void) sigprocmask(SIG_BLOCK, &set, &oset);

    if ((pid = fork()) == -1) {
        openlog(arg, LOG_PID | LOG_NDELAY, LOG_DAEMON);
        syslog(LOG_ERR, "Failed to start process in background.");
        exit(SMF_EXIT_ERR_CONFIG);
    }

    /* If we're the parent process, exit. */
    if (pid != 0) {
        _exit(0);
    }
    (void) setsid();
    (void) sigprocmask(SIG_SETMASK, &oset, NULL);
    (void) chdir("/");
    (void) umask(0);
}

static void
daemonize_fini(void)
{
    int fd;

    if ((fd = open("/dev/null", O_RDWR)) >= 0) {
        (void) fcntl(fd, F_DUP2FD, STDIN_FILENO);
        (void) fcntl(fd, F_DUP2FD, STDOUT_FILENO);
        (void) fcntl(fd, F_DUP2FD, STDERR_FILENO);
        (void) close(fd);
    }
}

/*
 * main
 *
 * The main NDMP daemon function
 *
 * Parameters:
 *   argc (input) - the argument count
 *   argv (input) - command line options
 *
 * Returns:
 *   0
 */
int
main(int argc, char *argv[])
{
    char c;
    struct sigaction act;
    sigset_t set;
    void *arg = 0;

    openlog(argv[0], LOG_PID | LOG_NDELAY, LOG_DAEMON);

    /*
     * Check for existing ndmpd door server (make sure ndmpd is not already
     * running)
     */
    if (ndmp_door_check()) {
        /* ndmpd is already running, exit. */
        return (0);
    }

    /* load ENVs */
    if (ndmpd_load_prop()) {
        syslog(LOG_ERR,
            "%s SMF properties initialization failed.", argv[0]);
        exit(SMF_EXIT_ERR_CONFIG);
    }

    /* Global zone check */
    if (getzoneid() != GLOBAL_ZONEID) {
        syslog(LOG_ERR, "Local zone not supported.");
        exit(SMF_EXIT_ERR_FATAL);
    }

    /* Trusted Solaris check */
    if (is_system_labeled()) {
        syslog(LOG_ERR, "Trusted Solaris not supported.");
        exit(SMF_EXIT_ERR_FATAL);
    }

    opterr = 0;
    while ((c = getopt(argc, argv, ":d")) != -1) {
        switch (c) {
        case 'd':
            (void) set_debug_level(TRUE);
            break;
        default:
            syslog(LOG_ERR, "%s: Invalid option -%c.",
                argv[0], optopt);
            syslog(LOG_ERR, "Usage: %s [-d]", argv[0]);
            exit(SMF_EXIT_ERR_CONFIG);
        }

    }

    closelog();
    /*
     * close any open file descriptors which are greater
     * than STDERR_FILENO
     */
    closefrom(STDERR_FILENO + 1);

    /* set up signal handler */
    (void) sigfillset(&set);
    (void) sigdelset(&set, SIGABRT); /* always unblocked for ASSERT() */
    (void) sigfillset(&act.sa_mask);
    act.sa_handler = ndmpd_sig_handler;
    act.sa_flags = 0;

    (void) sigaction(SIGTERM, &act, NULL);
    (void) sigaction(SIGHUP, &act, NULL);
    (void) sigaction(SIGINT, &act, NULL);
    (void) sigaction(SIGUSR1, &act, NULL);
    (void) sigdelset(&set, SIGTERM);
    (void) sigdelset(&set, SIGHUP);
    (void) sigdelset(&set, SIGINT);
    (void) sigdelset(&set, SIGUSR1);

    (void) daemonize_init(argv[0]);

    openlog(argv[0], LOG_PID | LOG_NDELAY, LOG_DAEMON);
    (void) mutex_init(&log_lock, 0, NULL);

    if (mod_init() != 0) {
        syslog(LOG_ERR, "Failed to load the plugin module.");
        exit(SMF_EXIT_ERR_CONFIG);
    }

    /* libzfs init */
    if ((zlibh = libzfs_init()) == NULL) {
        syslog(LOG_ERR, "Failed to initialize ZFS library.");
        exit(SMF_EXIT_ERR_CONFIG);
    }

    /* initialize and start the door server */
    if (ndmp_door_init()) {
        syslog(LOG_ERR, "Can not start ndmpd door server.");
        exit(SMF_EXIT_ERR_CONFIG);
    }

    (void) tlm_init();

    /*
     * Prior to this point, we are single-threaded. We will be
     * multi-threaded from this point on.
     */
    (void) pthread_create(NULL, NULL, (funct_t)ndmpd_main,
        (void *)&arg);

    while (!ndmpd.s_shutdown_flag) {
        (void) sigsuspend(&set);

        switch (ndmpd.s_sigval) {
        case 0:
            break;

        case SIGHUP:
            /* Refresh SMF properties */
            if (ndmpd_load_prop())
                syslog(LOG_ERR,
                    "Service properties initialization "
                    "failed.");
            break;

        default:
            /*
             * Typically SIGINT or SIGTERM.
             */
            ndmpd.s_shutdown_flag = 1;
            break;
        }

        ndmpd.s_sigval = 0;
    }

    (void) mutex_destroy(&log_lock);
    libzfs_fini(zlibh);
    mod_fini();
    ndmp_door_fini();
    daemonize_fini();
    free(ndmp_log_path);
    return (SMF_EXIT_OK);
}

static void
ndmpd_sig_handler(int sig)
{
    if (ndmpd.s_sigval == 0)
        ndmpd.s_sigval = sig;
}

/*
 * Enable libumem debugging by default on DEBUG builds.
 */
#ifdef DEBUG
const char *
_umem_debug_init(void)
{
    return ("default,verbose"); /* $UMEM_DEBUG setting */
}

const char *
_umem_logging_init(void)
{
    return ("fail,contents"); /* $UMEM_LOGGING setting */
}
#endif