--- old/usr/src/cmd/rcm_daemon/common/ttymux_rcm.c	Fri Aug  9 07:21:03 2019
+++ /dev/null	Fri Aug  9 00:52:51 2019
@@ -1,1434 +0,0 @@
-/*
- * CDDL HEADER START
- *
- * The contents of this file are subject to the terms of the
- * Common Development and Distribution License, Version 1.0 only
- * (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 2004 Sun Microsystems, Inc.  All rights reserved.
- * Use is subject to license terms.
- * Copyright (c) 2016 by Delphix. All rights reserved.
- */
-#pragma ident	"%Z%%M%	%I%	%E% SMI"
-
-#include <stdio.h>
-#include <stdlib.h>
-#include <stdarg.h>
-#include <unistd.h>
-#include <assert.h>
-#include <string.h>
-#include <limits.h>
-#include <synch.h>
-#include <libintl.h>
-#include <errno.h>
-#include <libdevinfo.h>
-#include <sys/uio.h>
-#include <sys/sysmacros.h>
-#include <sys/types.h>
-#include <stropts.h>
-#include <sys/stream.h>
-#include <fcntl.h>
-#include <sys/stat.h>
-#include <sys/mkdev.h>
-
-#include <sys/param.h>
-#include <sys/openpromio.h>
-#include <sys/ttymuxuser.h>
-
-#include "ttymux_rcm_impl.h"
-#include "rcm_module.h"
-
-#define	TTYMUX_OFFLINE_ERR	gettext("Resource is in use by")
-#define	TTYMUX_UNKNOWN_ERR	gettext("Unknown Operation attempted")
-#define	TTYMUX_ONLINE_ERR	gettext("Failed to connect under multiplexer")
-#define	TTYMUX_INVALID_ERR	gettext("Invalid Operation on this resource")
-#define	TTYMUX_OFFLINE_FAIL	gettext("Failed to disconnect from multiplexer")
-#define	TTYMUX_MEMORY_ERR	gettext("TTYMUX: strdup failure\n")
-
-
-static int  msglvl = 6;	/* print messages less than this level */
-#define	TEST(cond, stmt)  { if (cond) stmt; }
-#define	_msg(lvl, args)   TEST(msglvl > (lvl), trace args)
-
-static int	oflags = O_EXCL|O_RDWR|O_NONBLOCK|O_NOCTTY;
-static dev_t	cn_dev = NODEV;
-static rsrc_t	*cn_rsrc = NULL;
-static rsrc_t	cache_head;
-static rsrc_t	cache_tail;
-static mutex_t	cache_lock;
-static char	muxctl[PATH_MAX] = {0};
-static char	muxcon[PATH_MAX] = {0};
-static int	muxfd;
-static boolean_t	register_rsrcs;
-
-/* module interface routines */
-static int tty_register(rcm_handle_t *);
-static int tty_unregister(rcm_handle_t *);
-static int tty_getinfo(rcm_handle_t *, char *, id_t, uint_t, char **,
-    char **, nvlist_t *, rcm_info_t **);
-static int tty_suspend(rcm_handle_t *, char *, id_t,
-    timespec_t *, uint_t, char **, rcm_info_t **);
-static int tty_resume(rcm_handle_t *, char *, id_t, uint_t, char **,
-    rcm_info_t **);
-static int tty_offline(rcm_handle_t *, char *, id_t, uint_t, char **,
-    rcm_info_t **);
-static int tty_online(rcm_handle_t *, char *, id_t, uint_t, char **,
-    rcm_info_t **);
-static int tty_remove(rcm_handle_t *, char *, id_t, uint_t, char **,
-    rcm_info_t **);
-
-static int get_devpath(char *, char **, dev_t *);
-
-/*
- * Module-Private data
- */
-static struct rcm_mod_ops tty_ops = {
-	RCM_MOD_OPS_VERSION,
-	tty_register,
-	tty_unregister,
-	tty_getinfo,
-	tty_suspend,
-	tty_resume,
-	tty_offline,
-	tty_online,
-	tty_remove,
-	NULL,
-	NULL
-};
-
-/*PRINTFLIKE1*/
-static void
-trace(char *fmt, ...)
-{
-	va_list args;
-	char    buf[256];
-	int sz;
-
-	va_start(args, fmt);
-	sz = vsnprintf(buf, sizeof (buf), fmt, args);
-	va_end(args);
-
-	if (sz < 0)
-		rcm_log_message(RCM_TRACE1,
-		    _("TTYMUX: vsnprintf parse error\n"));
-	else if (sz > sizeof (buf)) {
-		char *b = malloc(sz + 1);
-
-		if (b != NULL) {
-			va_start(args, fmt);
-			sz = vsnprintf(b, sz + 1, fmt, args);
-			va_end(args);
-			if (sz > 0)
-				rcm_log_message(RCM_TRACE1, _("%s"), b);
-			free(b);
-		}
-	} else {
-		rcm_log_message(RCM_TRACE1, _("%s"), buf);
-	}
-}
-
-/*
- * CACHE MANAGEMENT
- * Resources managed by this module are stored in a list of rsrc_t
- * structures.
- */
-
-/*
- * cache_lookup()
- *
- * Get a cache node for a resource.  Call with cache lock held.
- */
-static rsrc_t *
-cache_lookup(const char *resource)
-{
-	rsrc_t *rsrc;
-	rsrc = cache_head.next;
-	while (rsrc != &cache_tail) {
-		if (rsrc->id && strcmp(resource, rsrc->id) == 0) {
-			return (rsrc);
-		}
-		rsrc = rsrc->next;
-	}
-	return (NULL);
-}
-
-/*
- * Get a cache node for a minor node.  Call with cache lock held.
- */
-static rsrc_t *
-cache_lookup_bydevt(dev_t devt)
-{
-	rsrc_t *rsrc;
-	rsrc = cache_head.next;
-	while (rsrc != &cache_tail) {
-		if (rsrc->dev == devt)
-			return (rsrc);
-		rsrc = rsrc->next;
-	}
-	return (NULL);
-}
-
-/*
- * free_node()
- *
- * Free a node.  Make sure it isn't in the list!
- */
-static void
-free_node(rsrc_t *node)
-{
-	if (node) {
-		if (node->id) {
-			free(node->id);
-		}
-		free(node);
-	}
-}
-
-/*
- * cache_insert()
- *
- * Call with the cache_lock held.
- */
-static void
-cache_insert(rsrc_t *node)
-{
-		/* insert at the head for best performance */
-		node->next = cache_head.next;
-		node->prev = &cache_head;
-
-		node->next->prev = node;
-		node->prev->next = node;
-}
-
-/*
- * cache_create()
- *
- * Call with the cache_lock held.
- */
-static rsrc_t *
-cache_create(const char *resource, dev_t dev)
-{
-	rsrc_t *rsrc = malloc(sizeof (rsrc_t));
-
-	if (rsrc != NULL) {
-		if ((rsrc->id = strdup(resource)) != NULL) {
-			rsrc->dev = dev;
-			rsrc->flags = 0;
-			rsrc->dependencies = NULL;
-			cache_insert(rsrc);
-		} else {
-			free(rsrc);
-			rsrc = NULL;
-		}
-	} else {
-		_msg(0, ("TTYMUX: malloc failure for resource %s.\n",
-		    resource));
-	}
-	return (rsrc);
-}
-
-/*
- * cache_get()
- *
- * Call with the cache_lock held.
- */
-static rsrc_t *
-cache_get(const char *resource)
-{
-	rsrc_t *rsrc = cache_lookup(resource);
-	if (rsrc == NULL) {
-		dev_t	dev;
-
-		(void) get_devpath((char *)resource, NULL, &dev);
-		rsrc = cache_create(resource, dev);
-	}
-	return (rsrc);
-}
-
-/*
- * cache_remove()
- *
- * Call with the cache_lock held.
- */
-static void
-cache_remove(rsrc_t *node)
-{
-	node->next->prev = node->prev;
-	node->prev->next = node->next;
-	node->next = NULL;
-	node->prev = NULL;
-}
-
-/*
- * Open a file identified by fname with the given open flags.
- * If the request is to open a file with exclusive access and the open
- * fails then backoff exponentially and then retry the open.
- * Do not wait for longer than about a second (since this may be an rcm
- * framework thread).
- */
-static int
-open_file(char *fname, int flags)
-{
-	int		fd, cnt;
-	struct timespec ts;
-
-	if ((flags & O_EXCL) == 0)
-		return (open(fname, flags));
-
-	ts.tv_sec = 0;
-	ts.tv_nsec = 16000000;	/* 16 milliseconds */
-
-	for (cnt = 0; cnt < 5 && (fd = open(fname, flags)) == -1; cnt++) {
-		(void) nanosleep(&ts, NULL);
-		ts.tv_nsec *= 2;
-	}
-	return (fd);
-}
-
-/*
- * No-op for creating an association between a pair of resources.
- */
-/*ARGSUSED*/
-static int
-nullconnect(link_t *link)
-{
-	return (0);
-}
-
-/*
- * No-op for destroying an association between a pair of resources.
- */
-/*ARGSUSED*/
-static int
-nulldisconnect(link_t *link)
-{
-	return (0);
-}
-
-/*
- * Record an actual or desired association between two resources
- * identified by their rsrc_t structures.
- */
-static link_t *
-add_dependency(rsrc_t *user, rsrc_t *used)
-{
-	link_t *linkhead;
-	link_t *link;
-
-	if (user == NULL || used == NULL)
-		return (NULL);
-
-	if (user->id && used->id && strcmp(user->id, used->id) == 0) {
-		_msg(2, ("TTYMUX: attempt to connect devices created by "
-		    "the same driver\n"));
-		return (NULL);
-	}
-
-	/*
-	 * Search for all resources that this resource user is depending
-	 * upon.
-	 */
-	linkhead = user->dependencies;
-	for (link = linkhead; link != NULL; link = link->next) {
-		/*
-		 * Does the using resource already depends on the used
-		 * resource
-		 */
-		if (link->used == used)
-			return (link);
-	}
-
-	link = malloc(sizeof (link_t));
-
-	if (link == NULL) {
-		rcm_log_message(RCM_ERROR, _("TTYMUX: Out of memory\n"));
-		return (NULL);
-	}
-
-	_msg(6, ("TTYMUX: New link user %s used %s\n", user->id, used->id));
-
-	link->user = user;
-	link->used = used;
-	link->linkid = 0;
-	link->state = UNKNOWN;
-	link->flags = 0;
-
-	link->connect = nullconnect;
-	link->disconnect = nulldisconnect;
-	link->next = linkhead;
-
-	user->dependencies = link;
-
-	return (link);
-}
-
-/*
- * Send an I_STR stream ioctl to a device
- */
-static int
-istrioctl(int fd, int cmd, void *data, int datalen, int *bytes) {
-	struct strioctl ios;
-	int rval;
-
-	ios.ic_timout = 0; /* use the default */
-	ios.ic_cmd = cmd;
-	ios.ic_dp = (char *)data;
-	ios.ic_len = datalen;
-
-	rval = ioctl(fd, I_STR, (char *)&ios);
-	if (bytes)
-		*bytes = ios.ic_len;
-	return (rval);
-}
-
-/*
- * Streams link the driver identified by fd underneath a mux
- * identified by ctrl_fd.
- */
-static int
-plink(int ctrl_fd, int fd)
-{
-	int linkid;
-
-	/*
-	 * pop any modules off the lower stream.
-	 */
-	while (ioctl(fd, I_POP, 0) == 0)
-		;
-
-	if ((linkid = ioctl(ctrl_fd, I_PLINK, fd)) < 0)
-		rcm_log_message(RCM_ERROR,
-		    _("TTYMUX: I_PLINK error %d.\n"), errno);
-	return (linkid);
-}
-
-/*
- * Streams unlink the STREAM identified by linkid from a mux
- * identified by ctrl_fd.
- */
-static int
-punlink(int ctrl_fd, int linkid)
-{
-	if (ioctl(ctrl_fd, I_PUNLINK, linkid) < 0)
-		return (errno);
-	else
-		return (0);
-}
-
-/*
- * Connect a pair of resources by establishing the dependency association.
- * Only works for devices that support the TTYMUX ioctls.
- */
-static int
-mux_connect(link_t *link)
-{
-	int lfd;
-	int rv;
-	ttymux_assoc_t as;
-	uint8_t ioflags;
-
-	_msg(6, ("TTYMUX: mux_connect (%ld:%ld<->%ld:%ld %s <-> %s\n",
-		major(link->user->dev), minor(link->user->dev),
-		major(link->used->dev), minor(link->used->dev),
-		link->user->id, link->used->id));
-
-	_msg(12, ("TTYMUX: struct size = %d (plen %d)\n",
-	    sizeof (as), PATH_MAX));
-
-	if (link->user->dev == NODEV || link->used->dev == NODEV) {
-		/*
-		 * One of the resources in the association is not
-		 * present (wait for the online notification before
-		 * attempting to establish the dependency association.
-		 */
-		return (EAGAIN);
-	}
-	if (major(link->user->dev) == major(link->used->dev)) {
-		_msg(2, ("TTYMUX: attempt to link devices created by "
-		    "the same driver\n"));
-		return (EINVAL);
-	}
-	/*
-	 * Explicitly check for attempts to plumb the system console -
-	 * required becuase not all serial devices support the
-	 * O_EXCL open flag.
-	 */
-	if (link->used->dev == cn_dev) {
-		rcm_log_message(RCM_WARNING, _("TTYMUX: Request to link the "
-		    " system console under another device not allowed!\n"));
-
-		return (EPERM);
-	}
-
-	/*
-	 * Ensure that the input/output mode of the dependent is reasonable
-	 */
-	if ((ioflags = link->flags & FORIO) == 0)
-		ioflags = FORIO;
-
-	/*
-	 * Open each resource participating in the association.
-	 */
-	lfd  = open(link->used->id, O_EXCL|O_RDWR|O_NONBLOCK|O_NOCTTY);
-	if (lfd == -1) {
-		if (errno == EBUSY) {
-			rcm_log_message(RCM_WARNING, _("TTYMUX: device %s is "
-			    " busy - " " cannot connect to %s\n"),
-			    link->used->id, link->user->id);
-		} else {
-			rcm_log_message(RCM_WARNING,
-			    _("TTYMUX: open error %d for device %s\n"),
-			    errno, link->used->id);
-		}
-		return (errno);
-	}
-	/*
-	 * Note: Issuing the I_PLINK and TTYMUX_ASSOC request on the 'using'
-	 * resource is more generic:
-	 * 	muxfd = open(link->user->id, oflags);
-	 * However using the ctl (MUXCTLLINK) node means that any current opens
-	 * on the 'using' resource are uneffected.
-	 */
-
-	/*
-	 * Figure out if the 'used' resource is already associated with
-	 * some resource - if so tell the caller to try again later.
-	 * More generally if any user or kernel thread has the resource
-	 * open then the association should not be made.
-	 * The ttymux driver makes this check (but it should be done here).
-	 */
-	as.ttymux_linkid = 0;
-	as.ttymux_ldev = link->used->dev;
-
-	if (istrioctl(muxfd, TTYMUX_GETLINK,
-		(void *)&as, sizeof (as), NULL) == 0) {
-
-		_msg(7, ("TTYMUX: %ld:%ld (%d) (udev %ld:%ld) already linked\n",
-		    major(as.ttymux_ldev), minor(as.ttymux_ldev),
-				as.ttymux_linkid, major(as.ttymux_udev),
-				minor(as.ttymux_udev)));
-		link->linkid = as.ttymux_linkid;
-		if (as.ttymux_udev != NODEV) {
-			(void) close(lfd);
-			return (EAGAIN);
-		}
-	}
-
-	/*
-	 * Now link and associate the used resource under the using resource.
-	 */
-	as.ttymux_udev = link->user->dev;
-	as.ttymux_ldev = link->used->dev;
-	as.ttymux_tag = 0ul;
-	as.ttymux_ioflag = ioflags;
-
-	_msg(6, ("TTYMUX: connecting %ld:%ld to %ld:%ld\n",
-		major(as.ttymux_ldev), minor(as.ttymux_ldev),
-		major(as.ttymux_udev), minor(as.ttymux_udev)));
-
-	if (as.ttymux_udev == cn_dev) {
-		struct termios tc;
-
-		if (ioctl(lfd, TCGETS, &tc) != -1) {
-			tc.c_cflag |= CREAD;
-			if (ioctl(lfd, TCSETSW, &tc) == -1) {
-				rcm_log_message(RCM_WARNING,
-				    _("TTYMUX: error %d whilst enabling the "
-				    "receiver on device %d:%d\n"),
-				    errno, major(as.ttymux_ldev),
-				    minor(as.ttymux_ldev));
-			}
-		}
-	}
-
-	if (as.ttymux_linkid <= 0 && (as.ttymux_linkid =
-			plink(muxfd, lfd)) <= 0) {
-		rcm_log_message(RCM_WARNING,
-		    _("TTYMUX: Link error %d for device %s\n"),
-		    errno, link->used->id);
-		rv = errno;
-		goto out;
-	}
-	link->linkid = as.ttymux_linkid;
-
-	_msg(6, ("TTYMUX: associating\n"));
-	if (istrioctl(muxfd, TTYMUX_ASSOC, (void *)&as, sizeof (as), 0) != 0) {
-		rv = errno;
-		goto out;
-	}
-	_msg(6, ("TTYMUX: Succesfully connected %ld:%ld to %ld:%ld\n",
-		major(as.ttymux_ldev), minor(as.ttymux_ldev),
-		major(as.ttymux_udev), minor(as.ttymux_udev)));
-	link->state = CONNECTED;
-	(void) close(lfd);
-	return (0);
-out:
-	rcm_log_message(RCM_WARNING,
-	    _("TTYMUX: Error [%d] connecting %d:%d to %d:%d\n"),
-	    rv, major(as.ttymux_ldev), minor(as.ttymux_ldev),
-	    major(as.ttymux_udev), minor(as.ttymux_udev));
-
-	(void) close(lfd);
-	if (as.ttymux_linkid > 0) {
-		/*
-		 * There was an error so unwind the I_PLINK step
-		 */
-		if (punlink(muxfd, as.ttymux_linkid) != 0)
-			rcm_log_message(RCM_WARNING,
-			    _("TTYMUX: Unlink error %d (%s).\n"),
-			    errno, link->used->id);
-	}
-	return (rv);
-}
-
-/*
- * Disconnect a pair of resources by destroying the dependency association.
- * Only works for devices that support the TTYMUX ioctls.
- */
-static int
-mux_disconnect(link_t *link)
-{
-	int rv;
-	ttymux_assoc_t as;
-
-	_msg(6, ("TTYMUX: mux_disconnect %s<->%s (%ld:%ld<->%ld:%ld)\n",
-	    link->user->id, link->used->id,
-	    major(link->user->dev), minor(link->user->dev),
-	    major(link->used->dev), minor(link->used->dev)));
-
-	as.ttymux_ldev = link->used->dev;
-
-	if (istrioctl(muxfd, TTYMUX_GETLINK,
-	    (void *)&as, sizeof (as), NULL) != 0) {
-
-		_msg(1, ("TTYMUX: %ld:%ld not linked [err %d]\n",
-		    major(link->used->dev), minor(link->used->dev), errno));
-		return (0);
-
-		/*
-		 * Do not disassociate console resources - simply
-		 * unlink them so that they remain persistent.
-		 */
-	} else if (as.ttymux_udev != cn_dev &&
-	    istrioctl(muxfd, TTYMUX_DISASSOC, (void *)&as,
-	    sizeof (as), 0) == -1) {
-
-		rv = errno;
-		rcm_log_message(RCM_WARNING,
-		    _("TTYMUX: Dissassociate error %d for %s\n"),
-		    rv, link->used->id);
-
-	} else if (punlink(muxfd, as.ttymux_linkid) != 0) {
-		rv = errno;
-		rcm_log_message(RCM_WARNING,
-		    _("TTYMUX: Error %d unlinking %d:%d\n"),
-		    errno, major(link->used->dev), minor(link->used->dev));
-	} else {
-		_msg(6, ("TTYMUX: %s<->%s disconnected.\n",
-		    link->user->id, link->used->id));
-
-		link->state = DISCONNECTED;
-		link->linkid = 0;
-		rv = 0;
-	}
-	return (rv);
-}
-
-/* PESISTENCY */
-
-/*
- * Given a special device file system path return the /devices path
- * and/or the device number (dev_t) of the device.
- */
-static int
-get_devpath(char *dev, char **cname, dev_t *devt)
-{
-	struct stat sb;
-
-	if (cname != NULL)
-		*cname = NULL;
-
-	if (devt != NULL)
-		*devt = NODEV;
-
-	if (lstat(dev, &sb) < 0) {
-		return (errno);
-	} else if ((sb.st_mode & S_IFMT) == S_IFLNK) {
-		int lsz;
-		char linkbuf[PATH_MAX+1];
-
-		if (stat(dev, &sb) < 0)
-			return (errno);
-
-		lsz = readlink(dev, linkbuf, PATH_MAX);
-
-		if (lsz <= 0)
-			return (ENODEV);
-		linkbuf[lsz] = '\0';
-		dev = strstr(linkbuf, "/devices");
-		if (dev == NULL)
-			return (ENODEV);
-	}
-
-	if (cname != NULL)
-		*cname = strdup(dev);
-
-	if (devt != NULL)
-		*devt = sb.st_rdev;
-
-	return (0);
-}
-
-/*
- * See routine locate_node
- */
-static int
-locate_dev(di_node_t node, di_minor_t minor, void *arg)
-{
-	char	*devfspath;
-	char	resource[PATH_MAX];
-	rsrc_t	*rsrc;
-
-	if (di_minor_devt(minor) != (dev_t)arg)
-		return (DI_WALK_CONTINUE);
-
-	if ((devfspath = di_devfs_path(node)) == NULL)
-		return (DI_WALK_TERMINATE);
-
-	if (snprintf(resource, sizeof (resource), "/devices%s:%s",
-	    devfspath, di_minor_name(minor)) > sizeof (resource)) {
-		di_devfs_path_free(devfspath);
-		return (DI_WALK_TERMINATE);
-	}
-
-	di_devfs_path_free(devfspath);
-
-	rsrc = cache_lookup(resource);
-	if (rsrc == NULL &&
-	    (rsrc = cache_create(resource, di_minor_devt(minor))) == NULL)
-		return (DI_WALK_TERMINATE);
-
-	rsrc->dev = di_minor_devt(minor);
-	rsrc->flags |= PRESENT;
-	rsrc->flags &= ~UNKNOWN;
-	return (DI_WALK_TERMINATE);
-}
-
-/*
- * Find a devinfo node that matches the device argument (dev).
- * This is an expensive search of the whole device tree!
- */
-static rsrc_t *
-locate_node(dev_t dev, di_node_t *root)
-{
-	rsrc_t		*rsrc;
-
-	assert(root != NULL);
-
-	if ((rsrc = cache_lookup_bydevt(dev)) != NULL)
-		return (rsrc);
-
-	(void) di_walk_minor(*root, NULL, 0, (void*)dev, locate_dev);
-
-	return (cache_lookup_bydevt(dev));
-}
-
-/*
- * Search for any existing dependency relationships managed by this
- * RCM module.
- */
-static int
-probe_dependencies()
-{
-	ttymux_assocs_t	links;
-	ttymux_assoc_t	*asp;
-	int		cnt, n;
-	rsrc_t		*ruser;
-	rsrc_t		*used;
-	link_t		*link;
-	di_node_t	root;
-
-	cnt = istrioctl(muxfd, TTYMUX_LIST, (void *)0, 0, 0);
-
-	_msg(8, ("TTYMUX: Probed %d links [%d]\n", cnt, errno));
-
-	if (cnt <= 0)
-		return (0);
-
-	if ((links.ttymux_assocs = calloc(cnt, sizeof (ttymux_assoc_t))) == 0)
-		return (EAGAIN);
-
-	links.ttymux_nlinks = cnt;
-
-	n = istrioctl(muxfd, TTYMUX_LIST, (void *)&links, sizeof (links), 0);
-
-	if (n == -1) {
-		_msg(2, ("TTYMUX: Probe error %s\n", strerror(errno)));
-		free(links.ttymux_assocs);
-		return (0);
-	}
-
-	asp = (ttymux_assoc_t *)links.ttymux_assocs;
-
-	if ((root = di_init("/", DINFOSUBTREE|DINFOMINOR)) == DI_NODE_NIL)
-		return (errno);
-
-	(void) mutex_lock(&cache_lock);
-	for (; cnt--; asp++) {
-		_msg(7, ("TTYMUX: Probed: %ld %ld %ld:%ld <->  %ld:%ld\n",
-		    asp->ttymux_udev, asp->ttymux_ldev,
-		    major(asp->ttymux_udev), minor(asp->ttymux_udev),
-		    major(asp->ttymux_ldev), minor(asp->ttymux_ldev)));
-		/*
-		 * The TTYMUX_LIST ioctl can return links relating
-		 * to potential devices. Such devices are identified
-		 * in the path field.
-		 */
-		if (asp->ttymux_ldev == NODEV) {
-			char	buf[PATH_MAX];
-
-			if (asp->ttymux_path == NULL ||
-				*asp->ttymux_path != '/')
-				continue;
-
-			if (snprintf(buf, sizeof (buf), "/devices%s",
-			    asp->ttymux_path) > sizeof (buf))
-				continue;
-
-			used = cache_get(buf);
-		} else {
-			used = locate_node(asp->ttymux_ldev, &root);
-		}
-		if ((ruser = locate_node(asp->ttymux_udev, &root)) == NULL) {
-			_msg(7, ("TTYMUX: Probe: %ld:%ld not present\n",
-			    major(asp->ttymux_udev), minor(asp->ttymux_udev)));
-			continue;
-		}
-		if (used == NULL) {
-			_msg(7, ("TTYMUX: Probe: %ld:%ld not present\n",
-			    major(asp->ttymux_ldev), minor(asp->ttymux_ldev)));
-			continue;
-		}
-		_msg(6, ("TTYMUX: Probe: Restore %s <-> %s (id %d)\n",
-		    ruser->id, used->id, asp->ttymux_linkid));
-
-		link = add_dependency(ruser, used);
-
-		if (link != NULL) {
-			link->flags = (uint_t)asp->ttymux_ioflag;
-			link->linkid = asp->ttymux_linkid;
-			link->state = CONNECTED;
-			link->connect = mux_connect;
-			link->disconnect = mux_disconnect;
-		}
-	}
-	di_fini(root);
-	(void) mutex_unlock(&cache_lock);
-	free(links.ttymux_assocs);
-	return (0);
-}
-
-/*
- * A resource has become available. Re-establish any associations involving
- * the resource.
- */
-static int
-rsrc_available(rsrc_t *rsrc)
-{
-	link_t	*link;
-	rsrc_t	*rs;
-
-	if (rsrc->dev == NODEV) {
-		/*
-		 * Now that the resource is present obtain its device number.
-		 * For this to work the node must be present in the /devices
-		 * tree (see devfsadm(1M) or drvconfig(1M)).
-		 * We do not use libdevinfo because the node must be present
-		 * under /devices for the connect step below to work
-		 * (the node needs to be opened).
-		 */
-		(void) get_devpath(rsrc->id, NULL, &rsrc->dev);
-		if (rsrc->dev == NODEV) {
-			_msg(4,
-			    ("Device node %s does not exist\n", rsrc->id));
-			/*
-			 * What does RCM do with failed online notifications.
-			 */
-			return (RCM_FAILURE);
-		}
-	}
-	for (rs  = cache_head.next; rs != &cache_tail; rs = rs->next) {
-		for (link = rs->dependencies;
-		    link != NULL;
-		    link = link->next) {
-			if (link->user == rsrc || link->used == rsrc) {
-				_msg(6, ("TTYMUX: re-connect\n"));
-				(void) link->connect(link);
-			}
-		}
-	}
-	return (RCM_SUCCESS);
-}
-
-/*
- * A resource is going away. Tear down any associations involving
- * the resource.
- */
-static int
-rsrc_unavailable(rsrc_t *rsrc)
-{
-	link_t	*link;
-	rsrc_t	*rs;
-
-	for (rs  = cache_head.next; rs != &cache_tail; rs = rs->next) {
-		for (link = rs->dependencies;
-		    link != NULL;
-		    link = link->next) {
-			if (link->user == rsrc || link->used == rsrc) {
-				_msg(6, ("TTYMUX: unavailable %s %s\n",
-				    link->user->id, link->used->id));
-				(void) link->disconnect(link);
-			}
-		}
-	}
-
-	return (RCM_SUCCESS);
-}
-
-/*
- * Find any resources that are using a given resource (identified by
- * the rsrc argument). The search begins after the resource identified
- * by the next argument. If next is NULL start at the first resource
- * in this RCM modules resource list. If the redundancy argument is
- * greater than zero then a resource which uses rsrc will only be
- * returned if it is associated with >= redundancy dependents.
- *
- * Thus, provided that the caller keeps the list locked it can iterate
- * through all the resources in the cache that depend upon rsrc.
- */
-static rsrc_t *
-get_next_user(rsrc_t *next, rsrc_t *rsrc, int redundancy)
-{
-	rsrc_t *src;
-	link_t *link;
-	int	cnt = 0;
-	boolean_t inuse;
-
-	src = (next != NULL) ? next->next : cache_head.next;
-
-	while (src != &cache_tail) {
-		inuse = B_FALSE;
-
-		for (link = src->dependencies, cnt = 0;
-			link != NULL;
-			link = link->next) {
-
-			if (link->state == CONNECTED)
-				cnt++;
-
-			if (link->used == rsrc)
-				inuse = B_TRUE;
-		}
-		if (inuse == B_TRUE &&
-		    (redundancy <= 0 || cnt == redundancy)) {
-			return (src);
-		}
-
-		src = src->next;
-	}
-
-	_msg(8, ("TTYMUX: count_users(%s) res %d.\n", rsrc->id, cnt));
-	return (NULL);
-}
-
-/*
- * Common handler for RCM notifications.
- */
-/*ARGSUSED*/
-static int
-rsrc_change_common(rcm_handle_t *hd, int op, const char *rsrcid, uint_t flag,
-	char **reason, rcm_info_t **dependent_reason, void *arg)
-{
-	rsrc_t	*rsrc, *user;
-	int	rv, len;
-	char	*tmp = NULL;
-
-	(void) mutex_lock(&cache_lock);
-	rsrc = cache_lookup(rsrcid);
-	if (rsrc == NULL) {
-		/* shouldn't happen because rsrc has been registered */
-		(void) mutex_unlock(&cache_lock);
-		return (RCM_SUCCESS);
-	}
-	if ((muxfd = open_file(muxctl, oflags)) == -1) {
-		rcm_log_message(RCM_ERROR, _("TTYMUX: %s unavailable: %s\n"),
-		    muxctl, strerror(errno));
-		(void) mutex_unlock(&cache_lock);
-		return (RCM_SUCCESS);
-	}
-	switch (op) {
-
-	case TTYMUX_SUSPEND:
-		rv = RCM_FAILURE;
-		_msg(4, ("TTYMUX: SUSPEND %s operation refused.\n",
-		    rsrc->id));
-		if ((*reason = strdup(TTYMUX_INVALID_ERR)) == NULL) {
-			rcm_log_message(RCM_ERROR, TTYMUX_MEMORY_ERR);
-		}
-		break;
-
-	case TTYMUX_REMOVE:
-		rsrc->flags |= UNKNOWN;
-		rsrc->flags &= ~(PRESENT | REGISTERED);
-		rv = RCM_SUCCESS;
-		break;
-
-	case TTYMUX_OFFLINE:
-		user = get_next_user(NULL, rsrc, 1);
-		if (flag & RCM_QUERY) {
-			rv = ((flag & RCM_FORCE) || (user == NULL)) ?
-						RCM_SUCCESS : RCM_FAILURE;
-			if (rv == RCM_FAILURE) {
-				tmp = TTYMUX_OFFLINE_ERR;
-				assert(tmp != NULL);
-				len = strlen(tmp) + strlen(user->id) + 2;
-				if ((*reason = (char *)malloc(len)) != NULL) {
-					(void) snprintf(*reason, len,
-							"%s %s", tmp, user->id);
-				} else {
-				rcm_log_message(RCM_ERROR, TTYMUX_MEMORY_ERR);
-				}
-			}
-
-		} else if (flag & RCM_FORCE) {
-			rv = rsrc_unavailable(rsrc);
-
-			if (rv == RCM_FAILURE) {
-				if ((*reason = strdup(TTYMUX_OFFLINE_FAIL)) ==
-								NULL) {
-					rcm_log_message(RCM_ERROR,
-							TTYMUX_MEMORY_ERR);
-				}
-			}
-
-		} else if (user != NULL) {
-			rv = RCM_FAILURE;
-			tmp = TTYMUX_OFFLINE_ERR;
-			assert(tmp != NULL);
-			len = strlen(tmp) + strlen(user->id) + 2;
-			if ((*reason = (char *)malloc(len)) != NULL) {
-					(void) snprintf(*reason, len,
-							"%s %s", tmp, user->id);
-			} else {
-				rcm_log_message(RCM_ERROR, TTYMUX_MEMORY_ERR);
-			}
-
-		} else  {
-			rv = rsrc_unavailable(rsrc);
-			if (rv == RCM_FAILURE) {
-				if ((*reason = strdup(TTYMUX_OFFLINE_FAIL)) ==
-								NULL) {
-					rcm_log_message(RCM_ERROR,
-							TTYMUX_MEMORY_ERR);
-				}
-			}
-		}
-
-		if (rv == RCM_FAILURE) {
-			_msg(4, ("TTYMUX: OFFLINE %s operation refused.\n",
-			    rsrc->id));
-
-		} else {
-			_msg(4, ("TTYMUX: OFFLINE %s res %d.\n", rsrc->id, rv));
-		}
-		break;
-
-	case TTYMUX_RESUME:
-		rv = RCM_FAILURE;
-		_msg(4, ("TTYMUX: RESUME %s operation refused.\n",
-		    rsrc->id));
-		if ((*reason = strdup(TTYMUX_INVALID_ERR)) == NULL) {
-			rcm_log_message(RCM_ERROR, TTYMUX_MEMORY_ERR);
-		}
-		break;
-
-	case TTYMUX_ONLINE:
-		_msg(4, ("TTYMUX: ONLINE %s res %d.\n", rsrc->id, rv));
-		rv = rsrc_available(rsrc);
-		if (rv == RCM_FAILURE) {
-			if ((*reason = strdup(TTYMUX_ONLINE_ERR)) == NULL) {
-				rcm_log_message(RCM_ERROR, TTYMUX_MEMORY_ERR);
-			}
-		}
-		break;
-	default:
-		rv = RCM_FAILURE;
-		if ((*reason = strdup(TTYMUX_UNKNOWN_ERR)) == NULL) {
-			rcm_log_message(RCM_ERROR, TTYMUX_MEMORY_ERR);
-		}
-	}
-
-	(void) close(muxfd);
-	(void) mutex_unlock(&cache_lock);
-	return (rv);
-}
-
-static boolean_t
-find_mux_nodes(char *drv)
-{
-	di_node_t	root, node;
-	di_minor_t	dim;
-	char		*devfspath;
-	char		muxctlname[] = "ctl";
-	char		muxconname[] = "con";
-	int		nminors = 0;
-
-	(void) strcpy(muxctl, MUXCTLLINK);
-	(void) strcpy(muxcon, MUXCONLINK);
-	cn_rsrc = NULL;
-
-	if ((root = di_init("/", DINFOCPYALL)) == DI_NODE_NIL) {
-		rcm_log_message(RCM_WARNING, _("di_init error\n"));
-		return (B_FALSE);
-	}
-
-	node = di_drv_first_node(drv, root);
-	if (node == DI_NODE_NIL) {
-		_msg(4, ("no node for %s\n", drv));
-		di_fini(root);
-		return (B_FALSE);
-	}
-	/*
-	 * If the device is not a prom node do not continue.
-	 */
-	if (di_nodeid(node) != DI_PROM_NODEID) {
-		di_fini(root);
-		return (B_FALSE);
-	}
-	if ((devfspath = di_devfs_path(node)) == NULL) {
-		di_fini(root);
-		return (B_FALSE);
-	}
-
-	/*
-	 * Loop through all the minor nodes the driver (drv) looking
-	 * for the ctl node (this is the device on which
-	 * to issue ioctls).
-	 */
-	dim = DI_MINOR_NIL;
-	while ((dim = di_minor_next(node, dim)) != DI_MINOR_NIL) {
-
-		_msg(7, ("MUXNODES: minor %s\n", di_minor_name(dim)));
-
-		if (strcmp(di_minor_name(dim), muxctlname) == 0) {
-			if (snprintf(muxctl, sizeof (muxctl),
-			    "/devices%s:%s", devfspath,
-			    di_minor_name(dim)) > sizeof (muxctl)) {
-				_msg(1, ("muxctl:snprintf error\n"));
-			}
-			if (++nminors == 2)
-				break;
-		} else if (strcmp(di_minor_name(dim), muxconname) == 0) {
-			if (snprintf(muxcon, sizeof (muxcon),
-			    "/devices%s:%s", devfspath,
-			    di_minor_name(dim)) > sizeof (muxcon)) {
-				_msg(1, ("muxcon:snprintf error\n"));
-			}
-			if (++nminors == 2)
-				break;
-		}
-	}
-
-	di_devfs_path_free(devfspath);
-	di_fini(root);
-
-	if ((muxfd = open_file(muxctl, oflags)) != -1) {
-
-		if (istrioctl(muxfd, TTYMUX_CONSDEV, (void *)&cn_dev,
-			    sizeof (cn_dev), 0) != 0) {
-				cn_dev = NODEV;
-		} else {
-			_msg(8, ("MUXNODES: found sys console: %ld:%ld\n",
-				major(cn_dev), minor(cn_dev)));
-
-			cn_rsrc = cache_create(muxcon, cn_dev);
-			if (cn_rsrc != NULL) {
-				cn_rsrc->flags |= PRESENT;
-				cn_rsrc->flags &= ~UNKNOWN;
-			}
-		}
-		(void) close(muxfd);
-
-		if (cn_dev != NODEV)
-			return (B_TRUE);
-	} else {
-		_msg(1, ("TTYMUX: %s unavailable: %s\n",
-		    muxctl, strerror(errno)));
-	}
-
-	return (B_FALSE);
-}
-
-/*
- * Update registrations, and return the ops structure.
- */
-struct rcm_mod_ops *
-rcm_mod_init()
-{
-	_msg(4, ("TTYMUX: mod_init:\n"));
-	cache_head.next = &cache_tail;
-	cache_head.prev = NULL;
-	cache_tail.prev = &cache_head;
-	cache_tail.next = NULL;
-	(void) mutex_init(&cache_lock, NULL, NULL);
-
-	/*
-	 * Find the multiplexer ctl and con nodes
-	 */
-	register_rsrcs = find_mux_nodes(TTYMUX_DRVNAME);
-
-	return (&tty_ops);
-}
-
-/*
- * Save state and release resources.
- */
-int
-rcm_mod_fini()
-{
-	rsrc_t	*rsrc;
-	link_t	*link, *nlink;
-
-	_msg(7, ("TTYMUX: freeing cache.\n"));
-	(void) mutex_lock(&cache_lock);
-	rsrc = cache_head.next;
-	while (rsrc != &cache_tail) {
-		cache_remove(rsrc);
-
-		for (link = rsrc->dependencies; link != NULL; ) {
-			nlink = link->next;
-			free(link);
-			link = nlink;
-		}
-
-		free_node(rsrc);
-		rsrc = cache_head.next;
-	}
-	(void) mutex_unlock(&cache_lock);
-
-	(void) mutex_destroy(&cache_lock);
-	return (RCM_SUCCESS);
-}
-
-/*
- * Return a string describing this module.
- */
-const char *
-rcm_mod_info()
-{
-	return ("Serial mux device module 1.1");
-}
-
-/*
- * RCM Notification Handlers
- */
-
-static int
-tty_register(rcm_handle_t *hd)
-{
-	rsrc_t	*rsrc;
-	link_t	*link;
-	int	rv;
-
-	if (register_rsrcs == B_FALSE)
-		return (RCM_SUCCESS);
-
-	if ((muxfd = open_file(muxctl, oflags)) == -1) {
-		rcm_log_message(RCM_ERROR, _("TTYMUX: %s unavailable: %s\n"),
-		    muxctl, strerror(errno));
-		return (RCM_SUCCESS);
-	}
-	/*
-	 * Search for any new dependencies since the last notification or
-	 * since module was initialisated.
-	 */
-	(void) probe_dependencies();
-
-	/*
-	 * Search the whole cache looking for any unregistered used resources
-	 * and register them. Note that the 'using resource' (a ttymux device
-	 * node) is not subject to DR operations so there is no need to
-	 * register them with the RCM framework.
-	 */
-	(void) mutex_lock(&cache_lock);
-	for (rsrc  = cache_head.next; rsrc != &cache_tail; rsrc = rsrc->next) {
-		_msg(6, ("TTYMUX: REGISTER rsrc %s flags %d\n",
-		    rsrc->id, rsrc->flags));
-
-		if (rsrc->dependencies != NULL &&
-			(rsrc->flags & REGISTERED) == 0) {
-			_msg(6, ("TTYMUX: Registering rsrc %s\n", rsrc->id));
-			rv = rcm_register_interest(hd, rsrc->id, 0, NULL);
-			if (rv == RCM_SUCCESS)
-				rsrc->flags |= REGISTERED;
-		}
-
-		for (link = rsrc->dependencies; link != NULL;
-			link = link->next) {
-			if ((link->used->flags & REGISTERED) != 0)
-				continue;
-
-			_msg(6, ("TTYMUX: Registering rsrc %s\n",
-			    link->used->id));
-			rv = rcm_register_interest(hd, link->used->id,
-				0, NULL);
-			if (rv != RCM_SUCCESS)
-				rcm_log_message(RCM_WARNING,
-				    _("TTYMUX: err %d registering %s\n"),
-				    rv, link->used->id);
-			else
-				link->used->flags |= REGISTERED;
-		}
-	}
-
-	(void) mutex_unlock(&cache_lock);
-	(void) close(muxfd);
-	return (RCM_SUCCESS);
-}
-
-/*
- * Unregister all registrations.
- */
-static int
-tty_unregister(rcm_handle_t *hd)
-{
-	rsrc_t	*rsrc;
-
-	(void) mutex_lock(&cache_lock);
-	/*
-	 * Search every resource in the cache and if it has been registered
-	 * then unregister it from the RCM framework.
-	 */
-	for (rsrc  = cache_head.next; rsrc != &cache_tail; rsrc = rsrc->next) {
-		if ((rsrc->flags & REGISTERED) == 0)
-			continue;
-
-		if (rcm_unregister_interest(hd, rsrc->id, 0) != RCM_SUCCESS)
-			rcm_log_message(RCM_WARNING,
-			    _("TTYMUX: Failed to unregister %s\n"), rsrc->id);
-		else
-			rsrc->flags &= ~REGISTERED;
-	}
-	(void) mutex_unlock(&cache_lock);
-	return (RCM_SUCCESS);
-}
-
-/*
- * Report resource usage information.
- */
-/*ARGSUSED*/
-static int
-tty_getinfo(rcm_handle_t *hd, char *rsrcid, id_t id, uint_t flag, char **info,
-    char **errstr, nvlist_t *proplist, rcm_info_t **depend_info)
-{
-	rsrc_t	*rsrc, *user;
-	char	*ru;
-	size_t	sz;
-
-	(void) mutex_lock(&cache_lock);
-	rsrc = cache_lookup(rsrcid);
-
-	if (rsrc == NULL) {
-		(void) mutex_unlock(&cache_lock);
-		*errstr = strdup(gettext("Unmanaged resource"));
-		return (RCM_FAILURE);
-	}
-
-	ru = strdup(gettext("Resource Users"));
-	user = NULL;
-	while ((user = get_next_user(user, rsrc, -1)) != NULL) {
-		*info = ru;
-		sz = strlen(*info) + strlen(user->id) + 2;
-		ru = malloc(sz);
-		if (ru == NULL) {
-			free(*info);
-			*info = NULL;
-			break;
-		}
-		if (snprintf(ru, sz, ": %s%s", *info, user->id) > sz) {
-			_msg(4, ("tty_getinfo: snprintf error.\n"));
-		}
-
-		free(*info);
-	}
-	*info = ru;
-
-	if (*info == NULL) {
-		(void) mutex_unlock(&cache_lock);
-		*errstr = strdup(gettext("Short of memory resources"));
-		return (RCM_FAILURE);
-	}
-
-	(void) mutex_unlock(&cache_lock);
-	return (RCM_SUCCESS);
-}
-
-/*ARGSUSED*/
-static int
-tty_offline(rcm_handle_t *hd, char *rsrc, id_t id, uint_t flags,
-    char **reason, rcm_info_t **dependent_reason)
-{
-	return (rsrc_change_common(hd, TTYMUX_OFFLINE, rsrc, flags,
-	    reason, dependent_reason, NULL));
-}
-
-/*ARGSUSED*/
-static int
-tty_remove(rcm_handle_t *hd, char *rsrc, id_t id, uint_t flags,
-    char **reason, rcm_info_t **dependent_reason)
-{
-	return (rsrc_change_common(hd, TTYMUX_REMOVE, rsrc, flags,
-	    reason, dependent_reason, NULL));
-}
-
-/*ARGSUSED*/
-static int
-tty_suspend(rcm_handle_t *hd, char *rsrc, id_t id, timespec_t *interval,
-    uint_t flag, char **reason, rcm_info_t **dependent_reason)
-{
-	return (rsrc_change_common(hd, TTYMUX_SUSPEND, rsrc, flag,
-	    reason, dependent_reason, (void *)interval));
-}
-
-/*ARGSUSED*/
-static int
-tty_online(rcm_handle_t *hd, char *rsrc, id_t id, uint_t flags,
-    char **reason, rcm_info_t **dependent_reason)
-{
-	return (rsrc_change_common(hd, TTYMUX_ONLINE, rsrc, flags,
-	    reason, dependent_reason, NULL));
-}
-
-/*ARGSUSED*/
-static int
-tty_resume(rcm_handle_t *hd, char *rsrc, id_t id, uint_t flags,
-    char **reason, rcm_info_t **dependent_reason)
-{
-	return (rsrc_change_common(hd, TTYMUX_RESUME, rsrc, flags,
-	    reason, dependent_reason, NULL));
-}
