usr/src/cmd/dlmgmtd/dlmgmt_main.c - illumos-gate - Gitiles

 /*
  * 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 2010 Sun Microsystems, Inc.  All rights reserved.
  * Use is subject to license terms.
  */

 /*
  * The dlmgmtd daemon is started by the datalink-management SMF service.
  * This daemon is used to manage <link name, linkid> mapping and the
  * persistent datalink configuration.
  *
  * Today, the <link name, linkid> mapping and the persistent configuration
  * of datalinks is kept in /etc/dladm/datalink.conf, and the daemon keeps
  * a copy of the datalinks in the memory (see dlmgmt_id_avl and
  * dlmgmt_name_avl). The active <link name, linkid> mapping is kept in
  * /etc/svc/volatile/dladm cache file, so that the mapping can be recovered
  * when dlmgmtd exits for some reason (e.g., when dlmgmtd is accidentally
  * killed).
  */

 #include <assert.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <priv.h>
 #include <signal.h>
 #include <stdlib.h>
 #include <stdio.h>
 #include <strings.h>
 #include <syslog.h>
 #include <zone.h>
 #include <sys/dld.h>
 #include <sys/dld_ioc.h>
 #include <sys/param.h>
 #include <sys/stat.h>
 #include <unistd.h>
 #include <libdladm_impl.h>
 #include <libdlmgmt.h>
 #include "dlmgmt_impl.h"

 const char		*progname;
 boolean_t		debug;
 static int		pfds[2];
 /*
  * This file descriptor to DLMGMT_DOOR cannot be in the libdladm
  * handle because the door isn't created when the handle is created.
  */
 static int		dlmgmt_door_fd = -1;

 /*
  * This libdladm handle is global so that dlmgmt_upcall_linkprop_init() can
  * pass to libdladm.  The handle is opened with "ALL" privileges, before
  * privileges are dropped in dlmgmt_drop_privileges().  It is not able to open
  * DLMGMT_DOOR at that time as it hasn't been created yet.  This door in the
  * handle is opened in the first call to dladm_door_fd().
  */
 dladm_handle_t		dld_handle = NULL;

 static void		dlmgmtd_exit(int);
 static int		dlmgmt_init();
 static void		dlmgmt_fini();
 static int		dlmgmt_set_privileges();

 static int
 dlmgmt_set_doorfd(boolean_t start)
 {
 	dld_ioc_door_t did;
 	int err = 0;

 	assert(dld_handle != NULL);

 	did.did_start_door = start;

 	if (ioctl(dladm_dld_fd(dld_handle), DLDIOC_DOORSERVER, &did) == -1)
 		err = errno;

 	return (err);
 }

 static int
 dlmgmt_door_init(void)
 {
 	int err = 0;

 	if ((dlmgmt_door_fd = door_create(dlmgmt_handler, NULL,
 	    DOOR_REFUSE_DESC | DOOR_NO_CANCEL)) == -1) {
 		err = errno;
 		dlmgmt_log(LOG_ERR, "door_create() failed: %s",
 		    strerror(err));
 		return (err);
 	}
 	return (err);
 }

 static void
 dlmgmt_door_fini(void)
 {
 	if (dlmgmt_door_fd == -1)
 		return;

 	if (door_revoke(dlmgmt_door_fd) == -1) {
 		dlmgmt_log(LOG_WARNING, "door_revoke(%s) failed: %s",
 		    DLMGMT_DOOR, strerror(errno));
 	}
 	(void) dlmgmt_set_doorfd(B_FALSE);
 	dlmgmt_door_fd = -1;
 }

 int
 dlmgmt_door_attach(zoneid_t zoneid, char *rootdir)
 {
 	int	fd;
 	int	err = 0;
 	char	doorpath[MAXPATHLEN];

 	(void) snprintf(doorpath, sizeof (doorpath), "%s%s", rootdir,
 	    DLMGMT_DOOR);

 	/*
 	 * Create the door file for dlmgmtd.
 	 */
 	if ((fd = open(doorpath, O_CREAT|O_RDONLY, 0644)) == -1) {
 		err = errno;
 		dlmgmt_log(LOG_ERR, "open(%s) failed: %s", doorpath,
 		    strerror(err));
 		return (err);
 	}
 	(void) close(fd);
 	if (chown(doorpath, UID_DLADM, GID_NETADM) == -1)
 		return (errno);

 	/*
 	 * fdetach first in case a previous daemon instance exited
 	 * ungracefully.
 	 */
 	(void) fdetach(doorpath);
 	if (fattach(dlmgmt_door_fd, doorpath) != 0) {
 		err = errno;
 		dlmgmt_log(LOG_ERR, "fattach(%s) failed: %s", doorpath,
 		    strerror(err));
 	} else if (zoneid == GLOBAL_ZONEID) {
 		if ((err = dlmgmt_set_doorfd(B_TRUE)) != 0) {
 			dlmgmt_log(LOG_ERR, "cannot set kernel doorfd: %s",
 			    strerror(err));
 		}
 	}

 	return (err);
 }

 /*
  * Create the /etc/svc/volatile/dladm/ directory if it doesn't exist, load the
  * datalink.conf data for this zone, and create/attach the door rendezvous
  * file.
  */
 int
 dlmgmt_zone_init(zoneid_t zoneid)
 {
 	char	rootdir[MAXPATHLEN], tmpfsdir[MAXPATHLEN];
 	int	err;
 	struct stat statbuf;

 	if (zoneid == GLOBAL_ZONEID) {
 		rootdir[0] = '\0';
 	} else if (zone_getattr(zoneid, ZONE_ATTR_ROOT, rootdir,
 	    sizeof (rootdir)) < 0) {
 		return (errno);
 	}

 	/*
 	 * Create the DLMGMT_TMPFS_DIR directory.
 	 */
 	(void) snprintf(tmpfsdir, sizeof (tmpfsdir), "%s%s", rootdir,
 	    DLMGMT_TMPFS_DIR);
 	if (stat(tmpfsdir, &statbuf) < 0) {
 		if (mkdir(tmpfsdir, (mode_t)0755) < 0)
 			return (errno);
 	} else if ((statbuf.st_mode & S_IFMT) != S_IFDIR) {
 		return (ENOTDIR);
 	}

 	if ((chmod(tmpfsdir, 0755) < 0) ||
 	    (chown(tmpfsdir, UID_DLADM, GID_NETADM) < 0)) {
 		return (EPERM);
 	}

 	if ((err = dlmgmt_db_init(zoneid)) != 0)
 		return (err);
 	return (dlmgmt_door_attach(zoneid, rootdir));
 }

 /*
  * Initialize each running zone.
  */
 static int
 dlmgmt_allzones_init(void)
 {
 	int		err, i;
 	zoneid_t	*zids = NULL;
 	uint_t		nzids, nzids_saved;

 	if (zone_list(NULL, &nzids) != 0)
 		return (errno);
 again:
 	nzids *= 2;
 	if ((zids = malloc(nzids * sizeof (zoneid_t))) == NULL)
 		return (errno);
 	nzids_saved = nzids;
 	if (zone_list(zids, &nzids) != 0) {
 		free(zids);
 		return (errno);
 	}
 	if (nzids > nzids_saved) {
 		free(zids);
 		goto again;
 	}

 	for (i = 0; i < nzids; i++) {
 		if ((err = dlmgmt_zone_init(zids[i])) != 0)
 			break;
 	}
 	free(zids);
 	return (err);
 }

 static int
 dlmgmt_init(void)
 {
 	int	err;
 	char	*fmri, *c;
 	char	filename[MAXPATHLEN];

 	if (dladm_open(&dld_handle) != DLADM_STATUS_OK) {
 		dlmgmt_log(LOG_ERR, "dladm_open() failed");
 		return (EPERM);
 	}

 	if (signal(SIGTERM, dlmgmtd_exit) == SIG_ERR ||
 	    signal(SIGINT, dlmgmtd_exit) == SIG_ERR) {
 		err = errno;
 		dlmgmt_log(LOG_ERR, "signal() for SIGTERM/INT failed: %s",
 		    strerror(err));
 		return (err);
 	}

 	/*
 	 * First derive the name of the cache file from the FMRI name. This
 	 * cache name is used to keep active datalink configuration.
 	 */
 	if (debug) {
 		(void) snprintf(cachefile, MAXPATHLEN, "%s/%s%s",
 		    DLMGMT_TMPFS_DIR, progname, ".debug.cache");
 	} else {
 		if ((fmri = getenv("SMF_FMRI")) == NULL) {
 			dlmgmt_log(LOG_ERR, "dlmgmtd is an smf(5) managed "
 			    "service and should not be run from the command "
 			    "line.");
 			return (EINVAL);
 		}

 		/*
 		 * The FMRI name is in the form of
 		 * svc:/service/service:instance.  We need to remove the
 		 * prefix "svc:/" and replace '/' with '-'.  The cache file
 		 * name is in the form of "service:instance.cache".
 		 */
 		if ((c = strchr(fmri, '/')) != NULL)
 			c++;
 		else
 			c = fmri;
 		(void) snprintf(filename, MAXPATHLEN, "%s.cache", c);
 		c = filename;
 		while ((c = strchr(c, '/')) != NULL)
 			*c = '-';

 		(void) snprintf(cachefile, MAXPATHLEN, "%s/%s",
 		    DLMGMT_TMPFS_DIR, filename);
 	}

 	dlmgmt_linktable_init();
 	if ((err = dlmgmt_door_init()) != 0)
 		goto done;

 	/*
 	 * Load datalink configuration and create dlmgmtd door files for all
 	 * currently running zones.
 	 */
 	if ((err = dlmgmt_allzones_init()) != 0)
 		dlmgmt_door_fini();

 done:
 	if (err != 0)
 		dlmgmt_linktable_fini();
 	return (err);
 }

 static void
 dlmgmt_fini(void)
 {
 	dlmgmt_door_fini();
 	dlmgmt_linktable_fini();
 	if (dld_handle != NULL) {
 		dladm_close(dld_handle);
 		dld_handle = NULL;
 	}
 }

 /*
  * This is called by the child process to inform the parent process to
  * exit with the given return value.
  */
 static void
 dlmgmt_inform_parent_exit(int rv)
 {
 	if (debug)
 		return;

 	if (write(pfds[1], &rv, sizeof (int)) != sizeof (int)) {
 		dlmgmt_log(LOG_WARNING,
 		    "dlmgmt_inform_parent_exit() failed: %s", strerror(errno));
 		(void) close(pfds[1]);
 		exit(EXIT_FAILURE);
 	}
 	(void) close(pfds[1]);
 }

 /*ARGSUSED*/
 static void
 dlmgmtd_exit(int signo)
 {
 	(void) close(pfds[1]);
 	dlmgmt_fini();
 	exit(EXIT_FAILURE);
 }

 static void
 usage(void)
 {
 	(void) fprintf(stderr, "Usage: %s [-d]\n", progname);
 	exit(EXIT_FAILURE);
 }

 /*
  * Restrict privileges to only those needed.
  */
 int
 dlmgmt_drop_privileges(void)
 {
 	priv_set_t	*pset;
 	priv_ptype_t	ptype;
 	zoneid_t	zoneid = getzoneid();
 	int		err = 0;

 	if ((pset = priv_allocset()) == NULL)
 		return (errno);

 	/*
 	 * The global zone needs PRIV_PROC_FORK so that it can fork() when it
 	 * issues db ops in non-global zones, PRIV_SYS_CONFIG to post
 	 * sysevents, and PRIV_SYS_DL_CONFIG to initialize link properties in
 	 * dlmgmt_upcall_linkprop_init().
 	 *
 	 * We remove non-basic privileges from the permitted (and thus
 	 * effective) set.  When executing in a non-global zone, dlmgmtd
 	 * only needs to read and write to files that it already owns.
 	 */
 	priv_basicset(pset);
 	(void) priv_delset(pset, PRIV_PROC_EXEC);
 	(void) priv_delset(pset, PRIV_PROC_INFO);
 	(void) priv_delset(pset, PRIV_PROC_SESSION);
 	(void) priv_delset(pset, PRIV_FILE_LINK_ANY);
 	if (zoneid == GLOBAL_ZONEID) {
 		ptype = PRIV_EFFECTIVE;
 		if (priv_addset(pset, PRIV_SYS_CONFIG) == -1 ||
 		    priv_addset(pset, PRIV_SYS_DL_CONFIG) == -1)
 			err = errno;
 	} else {
 		(void) priv_delset(pset, PRIV_PROC_FORK);
 		ptype = PRIV_PERMITTED;
 	}
 	if (err == 0 && setppriv(PRIV_SET, ptype, pset) == -1)
 		err = errno;
 done:
 	priv_freeset(pset);
 	return (err);
 }

 int
 dlmgmt_elevate_privileges(void)
 {
 	priv_set_t	*privset;
 	int		err = 0;

 	if ((privset = priv_str_to_set("zone", ",", NULL)) == NULL)
 		return (errno);
 	if (setppriv(PRIV_SET, PRIV_EFFECTIVE, privset) == -1)
 		err = errno;
 	priv_freeset(privset);
 	return (err);
 }

 /*
  * Set the uid of this daemon to the "dladm" user and drop privileges to only
  * those needed.
  */
 static int
 dlmgmt_set_privileges(void)
 {
 	int err;

 	(void) setgroups(0, NULL);
 	if (setegid(GID_NETADM) == -1 || seteuid(UID_DLADM) == -1)
 		err = errno;
 	else
 		err = dlmgmt_drop_privileges();
 done:
 	return (err);
 }

 /*
  * Keep the pfds fd open, close other fds.
  */
 /*ARGSUSED*/
 static int
 closefunc(void *arg, int fd)
 {
 	if (fd != pfds[1])
 		(void) close(fd);
 	return (0);
 }

 static boolean_t
 dlmgmt_daemonize(void)
 {
 	pid_t pid;
 	int rv;

 	if (pipe(pfds) < 0) {
 		(void) fprintf(stderr, "%s: pipe() failed: %s\n",
 		    progname, strerror(errno));
 		exit(EXIT_FAILURE);
 	}

 	if ((pid = fork()) == -1) {
 		(void) fprintf(stderr, "%s: fork() failed: %s\n",
 		    progname, strerror(errno));
 		exit(EXIT_FAILURE);
 	} else if (pid > 0) { /* Parent */
 		(void) close(pfds[1]);

 		/*
 		 * Read the child process's return value from the pfds.
 		 * If the child process exits unexpected, read() returns -1.
 		 */
 		if (read(pfds[0], &rv, sizeof (int)) != sizeof (int)) {
 			(void) kill(pid, SIGKILL);
 			rv = EXIT_FAILURE;
 		}

 		(void) close(pfds[0]);
 		exit(rv);
 	}

 	/* Child */
 	(void) close(pfds[0]);
 	(void) setsid();

 	/*
 	 * Close all files except pfds[1].
 	 */
 	(void) fdwalk(closefunc, NULL);
 	(void) chdir("/");
 	openlog(progname, LOG_PID, LOG_DAEMON);
 	return (B_TRUE);
 }

 int
 main(int argc, char *argv[])
 {
 	int opt, err;

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

 	/*
 	 * Process options.
 	 */
 	while ((opt = getopt(argc, argv, "d")) != EOF) {
 		switch (opt) {
 		case 'd':
 			debug = B_TRUE;
 			break;
 		default:
 			usage();
 		}
 	}

 	if (!debug && !dlmgmt_daemonize())
 		return (EXIT_FAILURE);

 	if ((err = dlmgmt_init()) != 0) {
 		dlmgmt_log(LOG_ERR, "unable to initialize daemon: %s",
 		    strerror(err));
 		goto child_out;
 	} else if ((err = dlmgmt_set_privileges()) != 0) {
 		dlmgmt_log(LOG_ERR, "unable to set daemon privileges: %s",
 		    strerror(err));
 		dlmgmt_fini();
 		goto child_out;
 	}

 	/*
 	 * Inform the parent process that it can successfully exit.
 	 */
 	dlmgmt_inform_parent_exit(EXIT_SUCCESS);

 	for (;;)
 		(void) pause();

 child_out:
 	/* return from main() forcibly exits an MT process */
 	dlmgmt_inform_parent_exit(EXIT_FAILURE);
 	return (EXIT_FAILURE);
 }
	/*
	* 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 2010 Sun Microsystems, Inc. All rights reserved.
	* Use is subject to license terms.
	*/

	/*
	* The dlmgmtd daemon is started by the datalink-management SMF service.
	* This daemon is used to manage <link name, linkid> mapping and the
	* persistent datalink configuration.
	*
	* Today, the <link name, linkid> mapping and the persistent configuration
	* of datalinks is kept in /etc/dladm/datalink.conf, and the daemon keeps
	* a copy of the datalinks in the memory (see dlmgmt_id_avl and
	* dlmgmt_name_avl). The active <link name, linkid> mapping is kept in
	* /etc/svc/volatile/dladm cache file, so that the mapping can be recovered
	* when dlmgmtd exits for some reason (e.g., when dlmgmtd is accidentally
	* killed).
	*/

	#include <assert.h>
	#include <errno.h>
	#include <fcntl.h>
	#include <priv.h>
	#include <signal.h>
	#include <stdlib.h>
	#include <stdio.h>
	#include <strings.h>
	#include <syslog.h>
	#include <zone.h>
	#include <sys/dld.h>
	#include <sys/dld_ioc.h>
	#include <sys/param.h>
	#include <sys/stat.h>
	#include <unistd.h>
	#include <libdladm_impl.h>
	#include <libdlmgmt.h>
	#include "dlmgmt_impl.h"

	const char *progname;
	boolean_t debug;
	static int pfds[2];
	/*
	* This file descriptor to DLMGMT_DOOR cannot be in the libdladm
	* handle because the door isn't created when the handle is created.
	*/
	static int dlmgmt_door_fd = -1;

	/*
	* This libdladm handle is global so that dlmgmt_upcall_linkprop_init() can
	* pass to libdladm. The handle is opened with "ALL" privileges, before
	* privileges are dropped in dlmgmt_drop_privileges(). It is not able to open
	* DLMGMT_DOOR at that time as it hasn't been created yet. This door in the
	* handle is opened in the first call to dladm_door_fd().
	*/
	dladm_handle_t dld_handle = NULL;

	static void dlmgmtd_exit(int);
	static int dlmgmt_init();
	static void dlmgmt_fini();
	static int dlmgmt_set_privileges();

	static int
	dlmgmt_set_doorfd(boolean_t start)
	{
	dld_ioc_door_t did;
	int err = 0;

	assert(dld_handle != NULL);

	did.did_start_door = start;

	if (ioctl(dladm_dld_fd(dld_handle), DLDIOC_DOORSERVER, &did) == -1)
	err = errno;

	return (err);
	}

	static int
	dlmgmt_door_init(void)
	{
	int err = 0;

	if ((dlmgmt_door_fd = door_create(dlmgmt_handler, NULL,
	DOOR_REFUSE_DESC \| DOOR_NO_CANCEL)) == -1) {
	err = errno;
	dlmgmt_log(LOG_ERR, "door_create() failed: %s",
	strerror(err));
	return (err);
	}
	return (err);
	}

	static void
	dlmgmt_door_fini(void)
	{
	if (dlmgmt_door_fd == -1)
	return;

	if (door_revoke(dlmgmt_door_fd) == -1) {
	dlmgmt_log(LOG_WARNING, "door_revoke(%s) failed: %s",
	DLMGMT_DOOR, strerror(errno));
	}
	(void) dlmgmt_set_doorfd(B_FALSE);
	dlmgmt_door_fd = -1;
	}

	int
	dlmgmt_door_attach(zoneid_t zoneid, char *rootdir)
	{
	int fd;
	int err = 0;
	char doorpath[MAXPATHLEN];

	(void) snprintf(doorpath, sizeof (doorpath), "%s%s", rootdir,
	DLMGMT_DOOR);

	/*
	* Create the door file for dlmgmtd.
	*/
	if ((fd = open(doorpath, O_CREAT\|O_RDONLY, 0644)) == -1) {
	err = errno;
	dlmgmt_log(LOG_ERR, "open(%s) failed: %s", doorpath,
	strerror(err));
	return (err);
	}
	(void) close(fd);
	if (chown(doorpath, UID_DLADM, GID_NETADM) == -1)
	return (errno);

	/*
	* fdetach first in case a previous daemon instance exited
	* ungracefully.
	*/
	(void) fdetach(doorpath);
	if (fattach(dlmgmt_door_fd, doorpath) != 0) {
	err = errno;
	dlmgmt_log(LOG_ERR, "fattach(%s) failed: %s", doorpath,
	strerror(err));
	} else if (zoneid == GLOBAL_ZONEID) {
	if ((err = dlmgmt_set_doorfd(B_TRUE)) != 0) {
	dlmgmt_log(LOG_ERR, "cannot set kernel doorfd: %s",
	strerror(err));
	}
	}

	return (err);
	}

	/*
	* Create the /etc/svc/volatile/dladm/ directory if it doesn't exist, load the
	* datalink.conf data for this zone, and create/attach the door rendezvous
	* file.
	*/
	int
	dlmgmt_zone_init(zoneid_t zoneid)
	{
	char rootdir[MAXPATHLEN], tmpfsdir[MAXPATHLEN];
	int err;
	struct stat statbuf;

	if (zoneid == GLOBAL_ZONEID) {
	rootdir[0] = '\0';
	} else if (zone_getattr(zoneid, ZONE_ATTR_ROOT, rootdir,
	sizeof (rootdir)) < 0) {
	return (errno);
	}

	/*
	* Create the DLMGMT_TMPFS_DIR directory.
	*/
	(void) snprintf(tmpfsdir, sizeof (tmpfsdir), "%s%s", rootdir,
	DLMGMT_TMPFS_DIR);
	if (stat(tmpfsdir, &statbuf) < 0) {
	if (mkdir(tmpfsdir, (mode_t)0755) < 0)
	return (errno);
	} else if ((statbuf.st_mode & S_IFMT) != S_IFDIR) {
	return (ENOTDIR);
	}

	if ((chmod(tmpfsdir, 0755) < 0) \|\|
	(chown(tmpfsdir, UID_DLADM, GID_NETADM) < 0)) {
	return (EPERM);
	}

	if ((err = dlmgmt_db_init(zoneid)) != 0)
	return (err);
	return (dlmgmt_door_attach(zoneid, rootdir));
	}

	/*
	* Initialize each running zone.
	*/
	static int
	dlmgmt_allzones_init(void)
	{
	int err, i;
	zoneid_t *zids = NULL;
	uint_t nzids, nzids_saved;

	if (zone_list(NULL, &nzids) != 0)
	return (errno);
	again:
	nzids *= 2;
	if ((zids = malloc(nzids * sizeof (zoneid_t))) == NULL)
	return (errno);
	nzids_saved = nzids;
	if (zone_list(zids, &nzids) != 0) {
	free(zids);
	return (errno);
	}
	if (nzids > nzids_saved) {
	free(zids);
	goto again;
	}

	for (i = 0; i < nzids; i++) {
	if ((err = dlmgmt_zone_init(zids[i])) != 0)
	break;
	}
	free(zids);
	return (err);
	}

	static int
	dlmgmt_init(void)
	{
	int err;
	char fmri, c;
	char filename[MAXPATHLEN];

	if (dladm_open(&dld_handle) != DLADM_STATUS_OK) {
	dlmgmt_log(LOG_ERR, "dladm_open() failed");
	return (EPERM);
	}

	if (signal(SIGTERM, dlmgmtd_exit) == SIG_ERR \|\|
	signal(SIGINT, dlmgmtd_exit) == SIG_ERR) {
	err = errno;
	dlmgmt_log(LOG_ERR, "signal() for SIGTERM/INT failed: %s",
	strerror(err));
	return (err);
	}

	/*
	* First derive the name of the cache file from the FMRI name. This
	* cache name is used to keep active datalink configuration.
	*/
	if (debug) {
	(void) snprintf(cachefile, MAXPATHLEN, "%s/%s%s",
	DLMGMT_TMPFS_DIR, progname, ".debug.cache");
	} else {
	if ((fmri = getenv("SMF_FMRI")) == NULL) {
	dlmgmt_log(LOG_ERR, "dlmgmtd is an smf(5) managed "
	"service and should not be run from the command "
	"line.");
	return (EINVAL);
	}

	/*
	* The FMRI name is in the form of
	* svc:/service/service:instance. We need to remove the
	* prefix "svc:/" and replace '/' with '-'. The cache file
	* name is in the form of "service:instance.cache".
	*/
	if ((c = strchr(fmri, '/')) != NULL)
	c++;
	else
	c = fmri;
	(void) snprintf(filename, MAXPATHLEN, "%s.cache", c);
	c = filename;
	while ((c = strchr(c, '/')) != NULL)
	*c = '-';

	(void) snprintf(cachefile, MAXPATHLEN, "%s/%s",
	DLMGMT_TMPFS_DIR, filename);
	}

	dlmgmt_linktable_init();
	if ((err = dlmgmt_door_init()) != 0)
	goto done;

	/*
	* Load datalink configuration and create dlmgmtd door files for all
	* currently running zones.
	*/
	if ((err = dlmgmt_allzones_init()) != 0)
	dlmgmt_door_fini();

	done:
	if (err != 0)
	dlmgmt_linktable_fini();
	return (err);
	}

	static void
	dlmgmt_fini(void)
	{
	dlmgmt_door_fini();
	dlmgmt_linktable_fini();
	if (dld_handle != NULL) {
	dladm_close(dld_handle);
	dld_handle = NULL;
	}
	}

	/*
	* This is called by the child process to inform the parent process to
	* exit with the given return value.
	*/
	static void
	dlmgmt_inform_parent_exit(int rv)
	{
	if (debug)
	return;

	if (write(pfds[1], &rv, sizeof (int)) != sizeof (int)) {
	dlmgmt_log(LOG_WARNING,
	"dlmgmt_inform_parent_exit() failed: %s", strerror(errno));
	(void) close(pfds[1]);
	exit(EXIT_FAILURE);
	}
	(void) close(pfds[1]);
	}

	/ARGSUSED/
	static void
	dlmgmtd_exit(int signo)
	{
	(void) close(pfds[1]);
	dlmgmt_fini();
	exit(EXIT_FAILURE);
	}

	static void
	usage(void)
	{
	(void) fprintf(stderr, "Usage: %s [-d]\n", progname);
	exit(EXIT_FAILURE);
	}

	/*
	* Restrict privileges to only those needed.
	*/
	int
	dlmgmt_drop_privileges(void)
	{
	priv_set_t *pset;
	priv_ptype_t ptype;
	zoneid_t zoneid = getzoneid();
	int err = 0;

	if ((pset = priv_allocset()) == NULL)
	return (errno);

	/*
	* The global zone needs PRIV_PROC_FORK so that it can fork() when it
	* issues db ops in non-global zones, PRIV_SYS_CONFIG to post
	* sysevents, and PRIV_SYS_DL_CONFIG to initialize link properties in
	* dlmgmt_upcall_linkprop_init().
	*
	* We remove non-basic privileges from the permitted (and thus
	* effective) set. When executing in a non-global zone, dlmgmtd
	* only needs to read and write to files that it already owns.
	*/
	priv_basicset(pset);
	(void) priv_delset(pset, PRIV_PROC_EXEC);
	(void) priv_delset(pset, PRIV_PROC_INFO);
	(void) priv_delset(pset, PRIV_PROC_SESSION);
	(void) priv_delset(pset, PRIV_FILE_LINK_ANY);
	if (zoneid == GLOBAL_ZONEID) {
	ptype = PRIV_EFFECTIVE;
	if (priv_addset(pset, PRIV_SYS_CONFIG) == -1 \|\|
	priv_addset(pset, PRIV_SYS_DL_CONFIG) == -1)
	err = errno;
	} else {
	(void) priv_delset(pset, PRIV_PROC_FORK);
	ptype = PRIV_PERMITTED;
	}
	if (err == 0 && setppriv(PRIV_SET, ptype, pset) == -1)
	err = errno;
	done:
	priv_freeset(pset);
	return (err);
	}

	int
	dlmgmt_elevate_privileges(void)
	{
	priv_set_t *privset;
	int err = 0;

	if ((privset = priv_str_to_set("zone", ",", NULL)) == NULL)
	return (errno);
	if (setppriv(PRIV_SET, PRIV_EFFECTIVE, privset) == -1)
	err = errno;
	priv_freeset(privset);
	return (err);
	}

	/*
	* Set the uid of this daemon to the "dladm" user and drop privileges to only
	* those needed.
	*/
	static int
	dlmgmt_set_privileges(void)
	{
	int err;

	(void) setgroups(0, NULL);
	if (setegid(GID_NETADM) == -1 \|\| seteuid(UID_DLADM) == -1)
	err = errno;
	else
	err = dlmgmt_drop_privileges();
	done:
	return (err);
	}

	/*
	* Keep the pfds fd open, close other fds.
	*/
	/ARGSUSED/
	static int
	closefunc(void *arg, int fd)
	{
	if (fd != pfds[1])
	(void) close(fd);
	return (0);
	}

	static boolean_t
	dlmgmt_daemonize(void)
	{
	pid_t pid;
	int rv;

	if (pipe(pfds) < 0) {
	(void) fprintf(stderr, "%s: pipe() failed: %s\n",
	progname, strerror(errno));
	exit(EXIT_FAILURE);
	}

	if ((pid = fork()) == -1) {
	(void) fprintf(stderr, "%s: fork() failed: %s\n",
	progname, strerror(errno));
	exit(EXIT_FAILURE);
	} else if (pid > 0) { /* Parent */
	(void) close(pfds[1]);

	/*
	* Read the child process's return value from the pfds.
	* If the child process exits unexpected, read() returns -1.
	*/
	if (read(pfds[0], &rv, sizeof (int)) != sizeof (int)) {
	(void) kill(pid, SIGKILL);
	rv = EXIT_FAILURE;
	}

	(void) close(pfds[0]);
	exit(rv);
	}

	/* Child */
	(void) close(pfds[0]);
	(void) setsid();

	/*
	* Close all files except pfds[1].
	*/
	(void) fdwalk(closefunc, NULL);
	(void) chdir("/");
	openlog(progname, LOG_PID, LOG_DAEMON);
	return (B_TRUE);
	}

	int
	main(int argc, char *argv[])
	{
	int opt, err;

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

	/*
	* Process options.
	*/
	while ((opt = getopt(argc, argv, "d")) != EOF) {
	switch (opt) {
	case 'd':
	debug = B_TRUE;
	break;
	default:
	usage();
	}
	}

	if (!debug && !dlmgmt_daemonize())
	return (EXIT_FAILURE);

	if ((err = dlmgmt_init()) != 0) {
	dlmgmt_log(LOG_ERR, "unable to initialize daemon: %s",
	strerror(err));
	goto child_out;
	} else if ((err = dlmgmt_set_privileges()) != 0) {
	dlmgmt_log(LOG_ERR, "unable to set daemon privileges: %s",
	strerror(err));
	dlmgmt_fini();
	goto child_out;
	}

	/*
	* Inform the parent process that it can successfully exit.
	*/
	dlmgmt_inform_parent_exit(EXIT_SUCCESS);

	for (;;)
	(void) pause();

	child_out:
	/* return from main() forcibly exits an MT process */
	dlmgmt_inform_parent_exit(EXIT_FAILURE);
	return (EXIT_FAILURE);
	}