/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright (c) 2004, 2010, Oracle and/or its affiliates. All rights reserved.
 */

#include <sys/types.h>
#include <sys/stat.h>
#include <sys/wait.h>
#include <sys/corectl.h>
#include <sys/resource.h>

#include <priv_utils.h>
#include <signal.h>
#include <unistd.h>
#include <limits.h>
#include <fcntl.h>
#include <strings.h>
#include <stdlib.h>
#include <stdio.h>
#include <zone.h>

#include <fmd_error.h>
#include <fmd_string.h>
#include <fmd_conf.h>
#include <fmd_dispq.h>
#include <fmd_subr.h>
#include <fmd.h>

fmd_t fmd;
mutex_t _svcstate_lock = ERRORCHECKMUTEX;

/*
 * For DEBUG builds, we define a set of hooks for libumem that provide useful
 * default settings for the allocator's debugging facilities.
 */
#ifdef  DEBUG
const char *
_umem_debug_init()
{
        return ("default,verbose"); /* $UMEM_DEBUG setting */
}

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

/*
 * We use a two-phase algorithm for becoming a daemon because we want the
 * daemon process (the child) to do the work of becoming MT-hot and opening our
 * event transport.  Since these operations can fail and need to result in the
 * daemon failing to start, the parent must wait until fmd_run() completes to
 * know whether it can return zero or non-zero status to the invoking command.
 * The parent waits on a pipe inside this function to read the exit status.
 * The child gets the write-end of the pipe returned by daemonize_init() and
 * then fmd_run() uses the pipe to set the exit status and detach the parent.
 */
static int
daemonize_init(void)
{
        const char *gzp1, *gzp2, *gzp3, *gzp4, *gzp5;
        int status, pfds[2];
        sigset_t set, oset;
        struct rlimit rlim;
        char path[PATH_MAX];
        pid_t pid;

        /*
         * Set our per-process core file path to leave core files in our
         * var/fm/fmd directory, named after the PID to aid in debugging,
         * and make sure that there is no restriction on core file size.
         */
        (void) snprintf(path, sizeof (path),
            "%s/var/fm/fmd/core.%s.%%p", fmd.d_rootdir, fmd.d_pname);

        (void) core_set_process_path(path, strlen(path) + 1, fmd.d_pid);

        rlim.rlim_cur = RLIM_INFINITY;
        rlim.rlim_max = RLIM_INFINITY;

        (void) setrlimit(RLIMIT_CORE, &rlim);

        /*
         * Claim all the file descriptors we can.
         */
        if (getrlimit(RLIMIT_NOFILE, &rlim) == 0) {
                rlim.rlim_cur = rlim.rlim_max;
                (void) setrlimit(RLIMIT_NOFILE, &rlim);
        }

        /*
         * Reset all of our privilege sets to the minimum set of required
         * privileges.  We continue to run as root so that files we create
         * such as logs and checkpoints are secured in the /var filesystem.
         *
         * In a non-global zone some of the privileges we retain in a
         * global zone are only optionally assigned to the zone, while others
         * are prohibited:
         *
         * PRIV_PROC_PRIOCNTL (optional in a non-global zone):
         *      There are no calls to priocntl(2) in fmd or plugins.
         *
         * PRIV_SYS_CONFIG (prohibited in a non-global zone):
         *      Required, I think, for sysevent_post_event and/or
         *      other legacy sysevent activity.  Legacy sysevent is not
         *      supported in a non-global zone.
         *
         * PRIV_SYS_DEVICES (prohibited in a non-global zone):
         *      Needed in the global zone for ioctls on various drivers
         *      such as memory-controller drivers.
         *
         * PRIV_SYS_RES_CONFIG (prohibited in a non-global zone):
         *      Require for p_online(2) calls to offline cpus.
         *
         * PRIV_SYS_NET_CONFIG (prohibited in a non-global zone):
         *      Required for ipsec in etm (which also requires
         *      PRIV_NET_PRIVADDR).
         *
         * We do without those privileges in a non-global zone.  It's
         * possible that there are other privs we could drop since
         * hardware-related plugins are not present.
         */
        if (getzoneid() == GLOBAL_ZONEID) {
                gzp1 = PRIV_PROC_PRIOCNTL;
                gzp2 = PRIV_SYS_CONFIG;
                gzp3 = PRIV_SYS_DEVICES;
                gzp4 = PRIV_SYS_RES_CONFIG;
                gzp5 = PRIV_SYS_NET_CONFIG;
        } else {
                gzp1 = gzp2 = gzp3 = gzp4 = gzp5 = NULL;
        }

        if (__init_daemon_priv(PU_RESETGROUPS | PU_LIMITPRIVS | PU_INHERITPRIVS,
            0, 0, /* run as uid 0 and gid 0 */
            PRIV_FILE_DAC_EXECUTE, PRIV_FILE_DAC_READ, PRIV_FILE_DAC_SEARCH,
            PRIV_FILE_DAC_WRITE, PRIV_FILE_OWNER, PRIV_PROC_OWNER,
            PRIV_SYS_ADMIN, PRIV_NET_PRIVADDR,
            gzp1, gzp2, gzp3, gzp4, gzp5, NULL) != 0)
                fmd_error(EFMD_EXIT, "additional privileges required to run\n");

        /*
         * 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 (pipe(pfds) == -1)
                fmd_error(EFMD_EXIT, "failed to create pipe for daemonize");

        if ((pid = fork()) == -1)
                fmd_error(EFMD_EXIT, "failed to fork into background");

        /*
         * If we're the parent process, wait for either the child to send us
         * the appropriate exit status over the pipe or for the read to fail
         * (presumably with 0 for EOF if our child terminated abnormally).
         * If the read fails, exit with either the child's exit status if it
         * exited or with FMD_EXIT_ERROR if it died from a fatal signal.
         */
        if (pid != 0) {
                (void) close(pfds[1]);

                if (read(pfds[0], &status, sizeof (status)) == sizeof (status))
                        _exit(status);

                if (waitpid(pid, &status, 0) == pid && WIFEXITED(status))
                        _exit(WEXITSTATUS(status));

                _exit(FMD_EXIT_ERROR);
        }

        fmd.d_pid = getpid();
        (void) setsid();
        (void) sigprocmask(SIG_SETMASK, &oset, NULL);
        (void) chdir("/");
        (void) umask(022);
        (void) close(pfds[0]);

        return (pfds[1]);
}

static void
daemonize_fini(int fd)
{
        (void) close(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);
        }
}

static void
handler(int sig)
{
        if (fmd.d_signal == 0)
                fmd.d_signal = sig;
}

static int
usage(const char *arg0, FILE *fp)
{
        (void) fprintf(fp,
            "Usage: %s [-V] [-f file] [-o opt=val] [-R dir]\n", arg0);

        return (FMD_EXIT_USAGE);
}

int
main(int argc, char *argv[])
{
        const char *opt_f = NULL, *opt_R = NULL;
        const char optstr[] = "f:o:R:V";
        int c, pfd = -1, opt_V = 0;
        char *p;

        struct sigaction act;
        sigset_t set;

        /*
         * Parse the command-line once to validate all options and retrieve
         * any overrides for our configuration file and root directory.
         */
        while ((c = getopt(argc, argv, optstr)) != EOF) {
                switch (c) {
                case 'f':
                        opt_f = optarg;
                        break;
                case 'o':
                        break; /* handle -o below */
                case 'R':
                        opt_R = optarg;
                        break;
                case 'V':
                        opt_V++;
                        break;
                default:
                        return (usage(argv[0], stderr));
                }
        }

        if (optind < argc)
                return (usage(argv[0], stderr));

        if (opt_V) {
#ifdef DEBUG
                const char *debug = " (DEBUG)";
#else
                const char *debug = "";
#endif
                (void) printf("%s: version %s%s\n",
                    argv[0], _fmd_version, debug);
                return (FMD_EXIT_SUCCESS);
        }

        closefrom(STDERR_FILENO + 1);
        fmd_create(&fmd, argv[0], opt_R, opt_f);

        /*
         * Now that we've initialized our global state, parse the command-line
         * again for any configuration options specified using -o and set them.
         */
        for (optind = 1; (c = getopt(argc, argv, optstr)) != EOF; ) {
                if (c == 'o') {
                        if ((p = strchr(optarg, '=')) == NULL) {
                                (void) fprintf(stderr, "%s: failed to set "
                                    "option -o %s: option requires value\n",
                                    fmd.d_pname, optarg);
                                return (FMD_EXIT_USAGE);
                        }

                        *p++ = '\0'; /* strike out the delimiter */

                        if (p[0] == '"' && p[strlen(p) - 1] == '"') {
                                p[strlen(p) - 1] = '\0';
                                (void) fmd_stresc2chr(++p);
                        }

                        if (fmd_conf_setprop(fmd.d_conf, optarg, p) != 0) {
                                (void) fprintf(stderr,
                                    "%s: failed to set option -o %s: %s\n",
                                    fmd.d_pname, optarg, fmd_strerror(errno));
                                return (FMD_EXIT_USAGE);
                        }
                }
        }

        if (fmd.d_fmd_debug & FMD_DBG_HELP) {
                fmd_help(&fmd);
                fmd_destroy(&fmd);
                return (FMD_EXIT_SUCCESS);
        }

        /*
         * Update the value of fmd.d_fg based on "fg" in case it changed.  We
         * use this property to decide whether to daemonize below.
         */
        (void) fmd_conf_getprop(fmd.d_conf, "fg", &fmd.d_fg);

        /*
         * Once we're done setting our global state up, set up signal handlers
         * for ensuring orderly termination on SIGTERM.  If we are starting in
         * the foreground, we also use the same handler for SIGINT and SIGHUP.
         */
        (void) sigfillset(&set);
        (void) sigdelset(&set, SIGABRT); /* always unblocked for ASSERT() */

        (void) sigfillset(&act.sa_mask);
        act.sa_handler = handler;
        act.sa_flags = 0;

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

        if (fmd.d_fg) {
                (void) sigaction(SIGHUP, &act, NULL);
                (void) sigdelset(&set, SIGHUP);
                (void) sigaction(SIGINT, &act, NULL);
                (void) sigdelset(&set, SIGINT);

                (void) sigdelset(&set, SIGTSTP);
                (void) sigdelset(&set, SIGTTIN);
                (void) sigdelset(&set, SIGTTOU);

                (void) printf("%s: [ loading modules ... ", fmd.d_pname);
                (void) fflush(stdout);
        } else
                pfd = daemonize_init();

        /*
         * Prior to this point, we are single-threaded.  Once fmd_run() is
         * called, we will be multi-threaded from this point on.  The daemon's
         * main thread will wait at the end of this function for signals.
         */
        fmd_run(&fmd, pfd);

        if (fmd.d_fg) {
                (void) printf("done ]\n");
                (void) printf("%s: [ awaiting events ]\n", fmd.d_pname);
        } else
                daemonize_fini(pfd);

        while (!fmd.d_signal)
                (void) sigsuspend(&set);

        fmd_destroy(&fmd);
        return (FMD_EXIT_SUCCESS);
}