Device megapatch 2/6:

This commit adds a couple of functions for pseudodrivers to use for
implementing cloning in a manner we will be able to lock down (shortly).

Basically what happens is that pseudo drivers get a way to ask for
"give me the dev_t with this unit number" or alternatively "give
me a dev_t with the lowest guaranteed free unit number" (there is
unfortunately a lot of non-POLA in the exact numeric value of this
number, just live with it for now)

Managing the unit number space this way removes the need to use
rman(9) to do so in the drivers this greatly simplifies the code in
the drivers because even using rman(9) they still needed to manage
their dev_t's anyway.

I have taken the if_tun, if_tap, snp and nmdm drivers through the
mill, partly because they (ab)used makedev(), but mostly because
together they represent three different problems for device-cloning:

if_tun and snp is the plain case: just give me a device.

if_tap has two kinds of devices, with a flag for device type.

nmdm has paired devices (ala pty) can you can clone either of them.

10 files changed, 342 insertions, 398 deletions

diff --git a/sys/conf/majors b/sys/conf/majors
index 62f5264..5671b38 100644
--- a/sys/conf/majors
+++ b/sys/conf/majors
@@ -23,7 +23,6 @@
 5	*pts		pseudo tty "tty" half
 6	*ptc		pseudo tty "master" half
 7	*log		system log
-18	*nmdm		nullmodem back-to-back tty ports
 19	*tw		X-10 power interface
 22	*fd		(/dev/stdin etc)
 30	*snd		sound driver system
@@ -37,7 +36,6 @@
 42	*cx		Cronyx/Sigma serial adapter
 43	vn		vnode "disk" device (retired)
 46	-		-
-52	*tun		IP tunnel device
 54	OLDnic		ISDN system
 58	-		Was dgb: Digiboard PC/Xe
 62	worm		SCSI "worm type"
@@ -77,7 +75,6 @@
 139	wanrouter	Sangoma Technologies Inc. (al.feldman@sangoma.com)
 141	pcdmx		PCDMX theatre lighting controller
 142	skip		SKIP port (security/skip) control device
-149	*tap		Ethernet tunneling device <myevmenkin@att.com>
 154	*asr		Adaptec SCSI RAID <msmith@freebsd.org>
 155	phone		Quicknet PhoneJACK and LineJACK cards for VoIP <roger>
 159	*ata		ATA control device
diff --git a/sys/dev/nmdm/nmdm.c b/sys/dev/nmdm/nmdm.c
index 3227b11..f3440dd 100644
--- a/sys/dev/nmdm/nmdm.c
+++ b/sys/dev/nmdm/nmdm.c
@@ -63,8 +63,7 @@ MALLOC_DEFINE(M_NLMDM, "nullmodem", "nullmodem data structures");
 static void 	nmdmstart(struct tty *tp);
 static void 	nmdmstop(struct tty *tp, int rw);
 static void 	wakeup_other(struct tty *tp, int flag);
-static void 	nmdminit(int);
-static int 	nmdmshutdown(void);
+static void 	nmdminit(dev_t dev);
 
 static d_open_t		nmdmopen;
 static d_close_t	nmdmclose;
@@ -72,7 +71,6 @@ static d_read_t		nmdmread;
 static d_write_t	nmdmwrite;
 static d_ioctl_t	nmdmioctl;
 
-#define	CDEV_MAJOR	18
 static struct cdevsw nmdm_cdevsw = {
 	.d_open =	nmdmopen,
 	.d_close =	nmdmclose,
@@ -80,14 +78,14 @@ static struct cdevsw nmdm_cdevsw = {
 	.d_write =	nmdmwrite,
 	.d_ioctl =	nmdmioctl,
 	.d_poll =	ttypoll,
-	.d_name =	"pts",
-	.d_maj =	CDEV_MAJOR,
-	.d_flags =	D_TTY,
+	.d_name =	"nmdm",
+	.d_flags =	D_TTY | D_PSEUDO,
 };
 
 #define BUFSIZ 		100		/* Chunk size iomoved to/from user */
 #define NMDM_MAX_NUM	128		/* Artificially limit # devices. */
 #define	PF_STOPPED	0x10		/* user told stopped */
+#define BFLAG		CLONE_FLAG0
 
 struct softpart {
 	struct tty	nm_tty;
@@ -97,11 +95,61 @@ struct softpart {
 };
 
 struct	nm_softc {
-	int	pt_flags;
-	struct softpart part1, part2;
-	struct	prison *pt_prison;
+	TAILQ_ENTRY(nm_softc)	pt_list;
+	int			pt_flags;
+	struct softpart 	part1, part2;
+	struct	prison 		*pt_prison;
 };
 
+static struct clonedevs *nmdmclones;
+static TAILQ_HEAD(,nm_softc) nmdmhead = TAILQ_HEAD_INITIALIZER(nmdmhead);
+
+static void
+nmdm_clone(void *arg, char *name, int nameen, dev_t *dev)
+{
+	int i, unit;
+	char *p;
+	dev_t d1, d2;
+
+	if (*dev != NODEV)
+		return;
+	if (strcmp(name, "nmdm") == 0) {
+		p = NULL;
+		unit = -1;
+	} else {
+		i = dev_stdclone(name, &p, "nmdm", &unit);
+		if (i == 0)
+			return;
+		if (p[0] != '\0' && p[0] != 'A' && p[0] != 'B')
+			return;
+		else if (p[0] != '\0' && p[1] != '\0')
+			return;
+	}
+	i = clone_create(&nmdmclones, &nmdm_cdevsw, &unit, &d1, 0);
+	if (i) {
+		d1 = make_dev(&nmdm_cdevsw, unit2minor(unit),
+		     0, 0, 0666, "nmdm%dA", unit);
+		if (d1 == NULL)
+			return;
+		d2 = make_dev(&nmdm_cdevsw, unit2minor(unit) | BFLAG,
+		     0, 0, 0666, "nmdm%dB", unit);
+		if (d2 == NULL) {
+			destroy_dev(d1);
+			return;
+		}
+		d2->si_drv2 = d1;
+		d1->si_drv2 = d2;
+		dev_depends(d1, d2);
+		dev_depends(d2, d1);
+		d1->si_flags |= SI_CHEAPCLONE;
+		d2->si_flags |= SI_CHEAPCLONE;
+	}
+	if (p != NULL && p[0] == 'B')
+		*dev = d1->si_drv2;
+	else
+		*dev = d1;
+}
+
 static void
 nmdm_crossover(struct nm_softc *pti,
 		struct softpart *ourpart,
@@ -123,24 +171,22 @@ do {	\
  * This function creates and initializes a pair of ttys.
  */
 static void
-nmdminit(n)
-	int n;
+nmdminit(dev_t dev1)
 {
-	dev_t dev1, dev2;
+	dev_t dev2;
 	struct nm_softc *pt;
 
-	/* For now we only map the lower 8 bits of the minor */
-	if (n & ~0xff)
-		return;
+	dev2 = dev1->si_drv2;
 
-	pt = malloc(sizeof(*pt), M_NLMDM, M_WAITOK);
-	bzero(pt, sizeof(*pt));
-	pt->part1.dev = dev1 = make_dev(&nmdm_cdevsw, n+n,
-	    0, 0, 0666, "nmdm%dA", n);
-	pt->part2.dev = dev2 = make_dev(&nmdm_cdevsw, n+n+1,
-	    0, 0, 0666, "nmdm%dB", n);
+	dev1->si_flags &= ~SI_CHEAPCLONE;
+	dev2->si_flags &= ~SI_CHEAPCLONE;
 
+	pt = malloc(sizeof(*pt), M_NLMDM, M_WAITOK | M_ZERO);
+	TAILQ_INSERT_TAIL(&nmdmhead, pt, pt_list);
 	dev1->si_drv1 = dev2->si_drv1 = pt;
+
+	pt->part1.dev = dev1;
+	pt->part2.dev = dev2;
 	dev1->si_tty = &pt->part1.nm_tty;
 	dev2->si_tty = &pt->part2.nm_tty;
 	ttyregister(&pt->part1.nm_tty);
@@ -148,9 +194,9 @@ nmdminit(n)
 	pt->part1.nm_tty.t_oproc = nmdmstart;
 	pt->part2.nm_tty.t_oproc = nmdmstart;
 	pt->part1.nm_tty.t_stop = nmdmstop;
+	pt->part2.nm_tty.t_stop = nmdmstop;
 	pt->part2.nm_tty.t_dev = dev1;
 	pt->part1.nm_tty.t_dev = dev2;
-	pt->part2.nm_tty.t_stop = nmdmstop;
 }
 
 /*
@@ -161,39 +207,14 @@ nmdmopen(dev_t dev, int flag, int devtype, struct thread *td)
 {
 	register struct tty *tp, *tp2;
 	int error;
-	int minr;
-	dev_t nextdev;
 	struct nm_softc *pti;
-	int is_b;
-	int	pair;
 	struct	softpart *ourpart, *otherpart;
 
-	/*
-	 * XXX: Gross hack for DEVFS:
-	 * If we openned this device, ensure we have the
-	 * next one too, so people can open it.
-	 */
-	minr = dev2unit(dev);
-	pair = minr >> 1;
-	is_b = minr & 1;
-	
-	if (pair < (NMDM_MAX_NUM - 1)) {
-		nextdev = makedev(major(dev), minr + 2);
-		if (!nextdev->si_drv1) {
-			nmdminit(pair + 1);
-		}
-	} else { /* Limit ourselves to 128 of them for now */
-		if (pair > (NMDM_MAX_NUM - 1))
-			return (ENXIO);
-	}
-	if (!dev->si_drv1)
-		nmdminit(pair);
-
-	if (!dev->si_drv1)
-		return(ENXIO);	
-
+	if (dev->si_drv1 == NULL)
+		nmdminit(dev);
 	pti = dev->si_drv1;
-	if (is_b) 
+
+	if (minor(dev) & BFLAG)
 		tp = &pti->part2.nm_tty;
 	else 
 		tp = &pti->part1.nm_tty;
@@ -567,20 +588,27 @@ nmdm_crossover(struct nm_softc *pti, struct softpart *ourpart,
 static int
 nmdm_modevent(module_t mod, int type, void *data)
 {
+	static eventhandler_tag tag;
+	struct nm_softc *pt, *tpt;
         int error = 0;
 
         switch(type) {
-        case MOD_LOAD: /* start with 4 of them */
-		nmdminit(0);
-		nmdminit(1);
-		nmdminit(2);
-		nmdminit(3);
+        case MOD_LOAD: 
+		tag = EVENTHANDLER_REGISTER(dev_clone, nmdm_clone, 0, 1000);
+		if (tag == NULL)
+			return (ENOMEM);
 		break;
 
 	case MOD_SHUTDOWN:
 		/* FALLTHROUGH */
 	case MOD_UNLOAD:
-		nmdmshutdown();
+		EVENTHANDLER_DEREGISTER(dev_clone, tag);
+		TAILQ_FOREACH_SAFE(pt, &nmdmhead, pt_list, tpt) {
+			destroy_dev(pt->part1.dev);
+			TAILQ_REMOVE(&nmdmhead, pt, pt_list);
+			free(pt, M_NLMDM);
+		}
+		clone_cleanup(&nmdmclones);
 		break;
 	default:
 		error = EOPNOTSUPP;
@@ -588,31 +616,4 @@ nmdm_modevent(module_t mod, int type, void *data)
 	return (error);
 }
 
-/*
- * Handle teardown of device
- */
-static int
-nmdmshutdown(void)
-{
-	int i;
-	dev_t	nextdev1;
-	dev_t	nextdev2;
-	void * ptr1;
-
-	for(i = 0;( i < NMDM_MAX_NUM) ;i++) {
-		nextdev1 = makedev(CDEV_MAJOR, (i+i) );
-		nextdev2 = makedev(CDEV_MAJOR, (i+i) + 1);
-		ptr1 = nextdev1->si_drv1;
-		if (ptr1) {
-			destroy_dev(nextdev1);
-			destroy_dev(nextdev2);
-			free(ptr1, M_NLMDM);
-		} else {
-			freedev(nextdev1);
-			freedev(nextdev2);
-		}
-	}
-	return(0);
-}
-
 DEV_MODULE(nmdm, nmdm_modevent, NULL);
diff --git a/sys/dev/snp/snp.c b/sys/dev/snp/snp.c
index 4c4115d..2c1c3c6 100644
--- a/sys/dev/snp/snp.c
+++ b/sys/dev/snp/snp.c
@@ -38,7 +38,6 @@ static	d_write_t	snpwrite;
 static	d_ioctl_t	snpioctl;
 static	d_poll_t	snppoll;
 
-#define CDEV_MAJOR 53
 static struct cdevsw snp_cdevsw = {
 	.d_open =	snpopen,
 	.d_close =	snpclose,
@@ -47,7 +46,7 @@ static struct cdevsw snp_cdevsw = {
 	.d_ioctl =	snpioctl,
 	.d_poll =	snppoll,
 	.d_name =	"snp",
-	.d_maj =	CDEV_MAJOR,
+	.d_flags =	D_PSEUDO,
 };
 
 static struct linesw snpdisc = {
@@ -101,10 +100,9 @@ static MALLOC_DEFINE(M_SNP, "snp", "Snoop device data");
  * module load time.
  */
 static int snooplinedisc;
-static udev_t snpbasedev = NOUDEV;
-
 
 static LIST_HEAD(, snoop) snp_sclist = LIST_HEAD_INITIALIZER(&snp_sclist);
+static struct clonedevs	  *snpclones;
 
 static struct tty	*snpdevtotty(dev_t dev);
 static void		snp_clone(void *arg, char *name,
@@ -384,9 +382,7 @@ snpopen(dev, flag, mode, td)
 	struct snoop *snp;
 
 	if (dev->si_drv1 == NULL) {
-		if (!(dev->si_flags & SI_NAMED))
-			make_dev(&snp_cdevsw, minor(dev), UID_ROOT, GID_WHEEL,
-			    0600, "snp%d", dev2unit(dev));
+		dev->si_flags &= ~SI_CHEAPCLONE;
 		dev->si_drv1 = snp = malloc(sizeof(*snp), M_SNP,
 		    M_WAITOK | M_ZERO);
 		snp->snp_unit = dev2unit(dev);
@@ -466,6 +462,7 @@ snpclose(dev, flags, fmt, td)
 	free(snp->snp_buf, M_SNP);
 	snp->snp_flags &= ~SNOOP_OPEN;
 	dev->si_drv1 = NULL;
+	destroy_dev(dev);
 
 	return (snp_detach(snp));
 }
@@ -608,20 +605,18 @@ snp_clone(arg, name, namelen, dev)
 	int namelen;
 	dev_t *dev;
 {
-	int u;
+	int u, i;
 
 	if (*dev != NODEV)
 		return;
 	if (dev_stdclone(name, NULL, "snp", &u) != 1)
 		return;
-	*dev = make_dev(&snp_cdevsw, unit2minor(u), UID_ROOT, GID_WHEEL, 0600,
-	    "snp%d", u);
-	if (snpbasedev == NOUDEV)
-		snpbasedev = (*dev)->si_udev;
-	else {
+	i = clone_create(&snpclones, &snp_cdevsw, &u, dev, 0);
+	if (i)
+		*dev = make_dev(&snp_cdevsw, unit2minor(u),
+		     UID_ROOT, GID_WHEEL, 0600, "snp%d", u);
+	if (*dev != NULL)
 		(*dev)->si_flags |= SI_CHEAPCLONE;
-		dev_depends(udev2dev(snpbasedev, 0), *dev);
-	}
 }
 
 static int
@@ -642,8 +637,7 @@ snp_modevent(mod, type, data)
 		if (!LIST_EMPTY(&snp_sclist))
 			return (EBUSY);
 		EVENTHANDLER_DEREGISTER(dev_clone, eh_tag);
-		if (snpbasedev != NOUDEV)
-			destroy_dev(udev2dev(snpbasedev, 0));
+		clone_cleanup(&snpclones);
 		ldisc_deregister(snooplinedisc);
 		break;
 	default:
@@ -657,4 +651,4 @@ static moduledata_t snp_mod = {
         snp_modevent,
         NULL
 };
-DECLARE_MODULE(snp, snp_mod, SI_SUB_DRIVERS, SI_ORDER_MIDDLE + CDEV_MAJOR);
+DECLARE_MODULE(snp, snp_mod, SI_SUB_DRIVERS, SI_ORDER_MIDDLE);
diff --git a/sys/kern/kern_conf.c b/sys/kern/kern_conf.c
index c99173d..62033c7 100644
--- a/sys/kern/kern_conf.c
+++ b/sys/kern/kern_conf.c
@@ -324,10 +324,22 @@ makeudev(int x, int y)
 }
 
 static void
-prep_cdevsw(struct cdevsw *devsw)
+find_major(struct cdevsw *devsw)
 {
 	int i;
 
+	for (i = NUMCDEVSW - 1; i > 0; i--)
+		if (reserved_majors[i] != i)
+			break;
+	KASSERT(i > 0, ("Out of major numbers (%s)", devsw->d_name));
+	devsw->d_maj = i;
+	reserved_majors[i] = i;
+}
+
+static void
+prep_cdevsw(struct cdevsw *devsw)
+{
+
 	if (devsw->d_open == NULL)	devsw->d_open = null_open;
 	if (devsw->d_close == NULL)	devsw->d_close = null_close;
 	if (devsw->d_read == NULL)	devsw->d_read = no_read;
@@ -339,12 +351,7 @@ prep_cdevsw(struct cdevsw *devsw)
 	if (devsw->d_dump == NULL)	devsw->d_dump = no_dump;
 	if (devsw->d_kqfilter == NULL)	devsw->d_kqfilter = no_kqfilter;
 	if (devsw->d_maj == MAJOR_AUTO) {
-		for (i = NUMCDEVSW - 1; i > 0; i--)
-			if (reserved_majors[i] != i)
-				break;
-		KASSERT(i > 0, ("Out of major numbers (%s)", devsw->d_name));
-		devsw->d_maj = i;
-		reserved_majors[i] = i;
+		find_major(devsw);
 	} else {
 		if (devsw->d_maj == 256)	/* XXX: tty_cons.c is magic */
 			devsw->d_maj = 0;	
@@ -458,17 +465,22 @@ destroy_dev(dev_t dev)
 	}
 		
 	devfs_destroy(dev);
+	dev->si_flags &= ~SI_NAMED;
+
 	if (dev->si_flags & SI_CHILD) {
 		LIST_REMOVE(dev, si_siblings);
 		dev->si_flags &= ~SI_CHILD;
 	}
 	while (!LIST_EMPTY(&dev->si_children))
 		destroy_dev(LIST_FIRST(&dev->si_children));
+	if (dev->si_flags & SI_CLONELIST) {
+		LIST_REMOVE(dev, si_clone);
+		dev->si_flags &= ~SI_CLONELIST;
+	}
 	dev->si_drv1 = 0;
 	dev->si_drv2 = 0;
 	dev->si_devsw = 0;
 	bzero(&dev->__si_u, sizeof(dev->__si_u));
-	dev->si_flags &= ~SI_NAMED;
 	dev->si_flags &= ~SI_ALIAS;
 	freedev(dev);
 }
@@ -523,6 +535,115 @@ dev_stdclone(char *name, char **namep, const char *stem, int *unit)
 }
 
 /*
+ * Helper functions for cloning device drivers.
+ *
+ * The objective here is to make it unnecessary for the device drivers to
+ * use rman or similar to manage their unit number space.  Due to the way
+ * we do "on-demand" devices, using rman or other "private" methods 
+ * will be very tricky to lock down properly once we lock down this file.
+ *
+ * Instead we give the drivers these routines which puts the dev_t's that
+ * are to be managed on their own list, and gives the driver the ability
+ * to ask for the first free unit number or a given specified unit number.
+ *
+ * In addition these routines support paired devices (pty, nmdm and similar)
+ * by respecting a number of "flag" bits in the minor number.
+ *
+ */
+
+struct clonedevs {
+	LIST_HEAD(,cdev)	head;
+};
+
+int
+clone_create(struct clonedevs **cdp, struct cdevsw *csw, int *up, dev_t *dp, u_int extra)
+{
+	struct clonedevs *cd;
+	dev_t dev, dl, de;
+	int unit, low, u;
+
+	KASSERT(!(extra & CLONE_UNITMASK),
+	     ("Illegal extra bits (0x%x) in clone_create", extra));
+	KASSERT(*up <= CLONE_UNITMASK,
+	     ("Too high unit (0x%x) in clone_create", *up));
+
+	if (csw->d_maj == MAJOR_AUTO)
+		find_major(csw);
+	/* if clonedevs have not been initialized, we do it here */
+	cd = *cdp;
+	if (cd == NULL) {
+		cd = malloc(sizeof *cd, M_DEVBUF, M_WAITOK | M_ZERO);
+		LIST_INIT(&cd->head);
+		*cdp = cd;
+	}
+
+	/*
+	 * Search the list for a lot of things in one go:
+	 *   A preexisting match is returned immediately.
+	 *   The lowest free unit number if we are passed -1, and the place
+	 *	 in the list where we should insert that new element.
+	 *   The place to insert a specified unit number, if applicable
+	 *       the end of the list.
+	 */
+	unit = *up;
+	low = 0;
+	de = dl = NULL;
+	LIST_FOREACH(dev, &cd->head, si_clone) {
+		u = dev2unit(dev);
+		if (u == (unit | extra)) {
+			*dp = dev;
+			return (0);
+		}
+		if (unit == -1 && u == low) {
+			low++;
+			de = dev;
+			continue;
+		}
+		if (u > unit) {
+			dl = dev;
+			break;
+		}
+		de = dev;
+	}
+	if (unit == -1)
+		unit = low;
+	dev = makedev(csw->d_maj, unit2minor(unit | extra));
+	KASSERT(!(dev->si_flags & SI_CLONELIST),
+	    ("Dev %p should not be on clonelist", dev));
+	if (dl != NULL)
+		LIST_INSERT_BEFORE(dl, dev, si_clone);
+	else if (de != NULL)
+		LIST_INSERT_AFTER(de, dev, si_clone);
+	else
+		LIST_INSERT_HEAD(&cd->head, dev, si_clone);
+	dev->si_flags |= SI_CLONELIST;
+	*up = unit;
+	return (1);
+}
+
+/*
+ * Kill everything still on the list.  The driver should already have
+ * disposed of any softc hung of the dev_t's at this time.
+ */
+void
+clone_cleanup(struct clonedevs **cdp)
+{
+	dev_t dev, tdev;
+	struct clonedevs *cd;
+	
+	cd = *cdp;
+	if (cd == NULL)
+		return;
+	LIST_FOREACH_SAFE(dev, &cd->head, si_clone, tdev) {
+		KASSERT(dev->si_flags & SI_NAMED,
+		    ("Driver has goofed in cloning underways udev %x", dev->si_udev));
+		destroy_dev(dev);
+	}
+	free(cd, M_DEVBUF);
+	*cdp = NULL;
+}
+
+/*
  * Helper sysctl for devname(3).  We're given a {u}dev_t and return
  * the name, if any, registered by the device driver.
  */
diff --git a/sys/net/if_tap.c b/sys/net/if_tap.c
index 82ae3b9..f83243b 100644
--- a/sys/net/if_tap.c
+++ b/sys/net/if_tap.c
@@ -54,8 +54,6 @@
 #include <sys/ttycom.h>
 #include <sys/uio.h>
 #include <sys/vnode.h>
-#include <machine/bus.h>	/* XXX: Shouldn't really be required! */
-#include <sys/rman.h>
 #include <sys/queue.h>
 
 #include <net/bpf.h>
@@ -71,14 +69,12 @@
 
 
 #define CDEV_NAME	"tap"
-#define CDEV_MAJOR	149
 #define TAPDEBUG	if (tapdebug) printf
 
 #define TAP		"tap"
 #define VMNET		"vmnet"
 #define TAPMAXUNIT	0x7fff
-#define VMNET_DEV_MASK	0x00800000
-		/*	0x007f00ff	*/
+#define VMNET_DEV_MASK	CLONE_FLAG0
 
 /* module */
 static int		tapmodevent(module_t, int, void *);
@@ -108,15 +104,12 @@ static struct cdevsw	tap_cdevsw = {
 	.d_ioctl =	tapioctl,
 	.d_poll =	tappoll,
 	.d_name =	CDEV_NAME,
-	.d_maj =	CDEV_MAJOR,
+	.d_flags =	D_PSEUDO,
 };
 
 static int			tapdebug = 0;        /* debug flag   */
 static SLIST_HEAD(, tap_softc)	taphead;             /* first device */
-static udev_t			tapbasedev = NOUDEV; /* base device  */
-static struct rman		tapdevunits[2];      /* device units */
-#define		tapunits	tapdevunits
-#define		vmnetunits	(tapdevunits + 1)
+static struct clonedevs 	*tapclones;
 
 MALLOC_DECLARE(M_TAP);
 MALLOC_DEFINE(M_TAP, CDEV_NAME, "Ethernet tunnel interface");
@@ -137,63 +130,27 @@ tapmodevent(mod, type, data)
 	static eventhandler_tag	 eh_tag = NULL;
 	struct tap_softc	*tp = NULL;
 	struct ifnet		*ifp = NULL;
-	int			 error, s;
+	int			 s;
 
 	switch (type) {
 	case MOD_LOAD:
-		/* initialize resources */
-		tapunits->rm_type = RMAN_ARRAY;
-		tapunits->rm_descr = "open tap units";
-		vmnetunits->rm_type = RMAN_ARRAY;
-		vmnetunits->rm_descr = "open vmnet units";
-
-		error = rman_init(tapunits);
-		if (error != 0)
-			goto bail;
-
-		error = rman_init(vmnetunits);
-		if (error != 0)
-			goto bail1;
-
-		error = rman_manage_region(tapunits, 0, TAPMAXUNIT);
-		if (error != 0)
-			goto bail2;
-
-		error = rman_manage_region(vmnetunits, 0, TAPMAXUNIT);
-		if (error != 0)
-			goto bail2;
 
 		/* intitialize device */
 
 		SLIST_INIT(&taphead);
 
 		eh_tag = EVENTHANDLER_REGISTER(dev_clone, tapclone, 0, 1000);
-		if (eh_tag == NULL) {
-			error = ENOMEM;
-			goto bail2;
-		}
-
-
+		if (eh_tag == NULL)
+			return (ENOMEM);
 		return (0);
-bail2:
-		rman_fini(vmnetunits);
-bail1:
-		rman_fini(tapunits);
-bail:
-		return (error);
 
 	case MOD_UNLOAD:
 		SLIST_FOREACH(tp, &taphead, tap_next)
-			if (tp->tap_unit != NULL)
+			if (tp->tap_flags & TAP_OPEN)
 				return (EBUSY);
 
 		EVENTHANDLER_DEREGISTER(dev_clone, eh_tag);
 
-		error = rman_fini(tapunits);
-		KASSERT((error == 0), ("Could not fini tap units"));
-		error = rman_fini(vmnetunits);
-		KASSERT((error == 0), ("Could not fini vmnet units"));
-
 		while ((tp = SLIST_FIRST(&taphead)) != NULL) {
 			SLIST_REMOVE_HEAD(&taphead, tap_next);
 
@@ -204,18 +161,14 @@ bail:
 			KASSERT(!(tp->tap_flags & TAP_OPEN), 
 				("%s flags is out of sync", ifp->if_xname));
 
-			/* XXX makedev check? nah.. not right now :) */
-
+			destroy_dev(tp->tap_dev);
 			s = splimp();
 			ether_ifdetach(ifp);
 			splx(s);
 
 			free(tp, M_TAP);
 		}
-
-		if (tapbasedev != NOUDEV)
-			destroy_dev(udev2dev(tapbasedev, 0));
-
+		clone_cleanup(&tapclones);
 
 		break;
 
@@ -239,65 +192,35 @@ tapclone(arg, name, namelen, dev)
 	int	 namelen;
 	dev_t	*dev;
 {
-	int		 unit, minor = 0 /* XXX avoid warning */ , error;
+	u_int		extra;
+	int		i, unit;
 	char		*device_name = name;
-	struct resource	*r = NULL;
 
 	if (*dev != NODEV)
 		return;
 
-	if (strcmp(device_name, TAP) == 0) {
-		/* get first free tap unit */
-		r = rman_reserve_resource(tapunits, 0, TAPMAXUNIT, 1,
-			RF_ALLOCATED | RF_ACTIVE, NULL);
-		unit = rman_get_start(r);
-		minor = unit2minor(unit);
-	}
-	else if (strcmp(device_name, VMNET) == 0) {
-		/* get first free vmnet unit */
-		r = rman_reserve_resource(vmnetunits, 0, TAPMAXUNIT, 1,
-			RF_ALLOCATED | RF_ACTIVE, NULL);
-		unit = rman_get_start(r);
-		minor = unit2minor(unit) | VMNET_DEV_MASK;
+	device_name = TAP;
+	extra = 0;
+	if (strcmp(name, TAP) == 0) {
+		unit = -1;
+	} else if (strcmp(name, VMNET) == 0) {
+		device_name = VMNET;
+		extra = VMNET_DEV_MASK;
+		unit = -1;
+	} else if (dev_stdclone(name, NULL, device_name, &unit) != 1) {
+		device_name = VMNET;
+		extra = VMNET_DEV_MASK;
+		if (dev_stdclone(name, NULL, device_name, &unit) != 1)
+			return;
 	}
 
-	if (r != NULL) { /* need cloning */
-		TAPDEBUG("%s%d is available. minor = %#x\n",
-			device_name, unit, minor);
-
-		error = rman_release_resource(r);
-		KASSERT((error == 0), ("Could not release tap/vmnet unit"));
-
-		/* check if device for the unit has been created */
-		*dev = makedev(CDEV_MAJOR, minor);
-		if ((*dev)->si_flags & SI_NAMED) {
-			TAPDEBUG("%s%d device exists. minor = %#x\n",
-				device_name, unit, minor);
-			return; /* device has been created */
-		}
-	} else { /* try to match name/unit, first try tap then vmnet */
-		device_name = TAP;
-		if (dev_stdclone(name, NULL, device_name, &unit) != 1) {
-			device_name = VMNET;
-
-			if (dev_stdclone(name, NULL, device_name, &unit) != 1)
-				return;
-
-			minor = unit2minor(unit) | VMNET_DEV_MASK;
-		} else
-			minor = unit2minor(unit);
-	}
-
-	TAPDEBUG("make_dev(%s%d). minor = %#x\n", device_name, unit, minor);
-
-	*dev = make_dev(&tap_cdevsw, minor, UID_ROOT, GID_WHEEL, 0600, "%s%d",
-			device_name, unit);
-
-	if (tapbasedev == NOUDEV)
-		tapbasedev = (*dev)->si_udev;
-	else {
-		(*dev)->si_flags |= SI_CHEAPCLONE;
-		dev_depends(udev2dev(tapbasedev, 0), *dev);
+	/* find any existing device, or allocate new unit number */
+	i = clone_create(&tapclones, &tap_cdevsw, &unit, dev, extra);
+	if (i) {
+		*dev = make_dev(&tap_cdevsw, unit2minor(unit) | extra,
+		     UID_ROOT, GID_WHEEL, 0600, "%s%d", device_name, unit);
+		if (*dev != NULL)
+			(*dev)->si_flags |= SI_CHEAPCLONE;
 	}
 } /* tapclone */
 
@@ -317,6 +240,8 @@ tapcreate(dev)
 	int			 unit, s;
 	char			*name = NULL;
 
+	dev->si_flags &= ~SI_CHEAPCLONE;
+
 	/* allocate driver storage and create device */
 	MALLOC(tp, struct tap_softc *, sizeof(*tp), M_TAP, M_WAITOK | M_ZERO);
 	SLIST_INSERT_HEAD(&taphead, tp, tap_next);
@@ -354,6 +279,7 @@ tapcreate(dev)
 	ifp->if_snd.ifq_maxlen = ifqmaxlen;
 
 	dev->si_drv1 = tp;
+	tp->tap_dev = dev;
 
 	s = splimp();
 	ether_ifattach(ifp, tp->arpcom.ac_enaddr);
@@ -380,24 +306,12 @@ tapopen(dev, flag, mode, td)
 {
 	struct tap_softc	*tp = NULL;
 	int			 unit, error;
-	struct resource		*r = NULL;
 
 	if ((error = suser(td)) != 0)
 		return (error);
 
 	unit = dev2unit(dev) & TAPMAXUNIT;
 
-	if (minor(dev) & VMNET_DEV_MASK)
-		r = rman_reserve_resource(vmnetunits, unit, unit, 1,
-			RF_ALLOCATED | RF_ACTIVE, NULL);
-	else
-		r = rman_reserve_resource(tapunits, unit, unit, 1,
-			RF_ALLOCATED | RF_ACTIVE, NULL);
-
-	if (r == NULL)
-		return (EBUSY);
-
-	dev->si_flags &= ~SI_CHEAPCLONE;
 
 	tp = dev->si_drv1;
 	if (tp == NULL) {
@@ -410,7 +324,6 @@ tapopen(dev, flag, mode, td)
 
 	bcopy(tp->arpcom.ac_enaddr, tp->ether_addr, sizeof(tp->ether_addr));
 
-	tp->tap_unit = r;
 	tp->tap_pid = td->td_proc->p_pid;
 	tp->tap_flags |= TAP_OPEN;
 
@@ -433,12 +346,9 @@ tapclose(dev, foo, bar, td)
 	int		 bar;
 	struct thread	*td;
 {
-	int			 s, error;
 	struct tap_softc	*tp = dev->si_drv1;
 	struct ifnet		*ifp = &tp->tap_if;
-
-	KASSERT((tp->tap_unit != NULL),
-		("%s is not open", ifp->if_xname));
+	int			s;
 
 	/* junk all pending output */
 	IF_DRAIN(&ifp->if_snd);
@@ -479,10 +389,6 @@ tapclose(dev, foo, bar, td)
 
 	tp->tap_flags &= ~TAP_OPEN;
 	tp->tap_pid = 0;
-	error = rman_release_resource(tp->tap_unit);
-	KASSERT((error == 0), 
-		("%s could not release unit", ifp->if_xname)); 
-	tp->tap_unit = NULL;
 
 	TAPDEBUG("%s is closed. minor = %#x\n", 
 		ifp->if_xname, minor(dev));
diff --git a/sys/net/if_tapvar.h b/sys/net/if_tapvar.h
index 06e3bbdf..ae6c3cd 100644
--- a/sys/net/if_tapvar.h
+++ b/sys/net/if_tapvar.h
@@ -61,6 +61,7 @@ struct tap_softc {
 	struct selinfo	 tap_rsel;		/* read select               */
 
 	SLIST_ENTRY(tap_softc)	tap_next;	/* next device in chain      */
+	dev_t		 tap_dev;
 };
 
 #endif /* !_NET_IF_TAPVAR_H_ */
diff --git a/sys/net/if_tun.c b/sys/net/if_tun.c
index 516d299..4a64da4 100644
--- a/sys/net/if_tun.c
+++ b/sys/net/if_tun.c
@@ -41,9 +41,7 @@
 #include <sys/uio.h>
 #include <sys/vnode.h>
 #include <sys/malloc.h>
-#include <machine/bus.h>	/* XXX Shouldn't really be required ! */
 #include <sys/random.h>
-#include <sys/rman.h>
 
 #include <net/if.h>
 #include <net/if_types.h>
@@ -53,17 +51,40 @@
 #include <netinet/in.h>
 #endif
 #include <net/bpf.h>
-#include <net/if_tunvar.h>
 #include <net/if_tun.h>
 
+#include <sys/queue.h>
+
+struct tun_softc {
+	TAILQ_ENTRY(tun_softc)	tun_list;
+	int			tun_unit;
+	dev_t			tun_dev;
+	u_short	tun_flags;		/* misc flags */
+#define	TUN_OPEN	0x0001
+#define	TUN_INITED	0x0002
+#define	TUN_RCOLL	0x0004
+#define	TUN_IASET	0x0008
+#define	TUN_DSTADDR	0x0010
+#define	TUN_LMODE	0x0020
+#define	TUN_RWAIT	0x0040
+#define	TUN_ASYNC	0x0080
+#define	TUN_IFHEAD	0x0100
+
+#define TUN_READY       (TUN_OPEN | TUN_INITED)
+
+	struct proc		*tun_proc;	/* Owning process */
+	struct	ifnet tun_if;		/* the interface */
+	struct  sigio *tun_sigio;	/* information for async I/O */
+	struct	selinfo	tun_rsel;	/* read select */
+};
+
 #define TUNDEBUG	if (tundebug) if_printf
 #define	TUNNAME		"tun"
 
 static MALLOC_DEFINE(M_TUN, TUNNAME, "Tunnel Interface");
 static int tundebug = 0;
-static struct tun_softc *tunhead = NULL;
-static struct rman tununits;
-static udev_t tunbasedev = NOUDEV;
+static struct clonedevs *tunclones;
+static TAILQ_HEAD(,tun_softc)	tunhead = TAILQ_HEAD_INITIALIZER(tunhead);
 SYSCTL_INT(_debug, OID_AUTO, if_tun_debug, CTLFLAG_RW, &tundebug, 0, "");
 
 static void	tunclone(void *arg, char *name, int namelen, dev_t *dev);
@@ -82,7 +103,6 @@ static d_write_t	tunwrite;
 static d_ioctl_t	tunioctl;
 static d_poll_t		tunpoll;
 
-#define CDEV_MAJOR 52
 static struct cdevsw tun_cdevsw = {
 	.d_open =	tunopen,
 	.d_close =	tunclose,
@@ -91,44 +111,32 @@ static struct cdevsw tun_cdevsw = {
 	.d_ioctl =	tunioctl,
 	.d_poll =	tunpoll,
 	.d_name =	TUNNAME,
-	.d_maj =	CDEV_MAJOR,
+	.d_flags =	D_PSEUDO,
 };
 
 static void
 tunclone(void *arg, char *name, int namelen, dev_t *dev)
 {
-	struct resource *r;
-	int err;
-	int u;
+	int u, i;
 
 	if (*dev != NODEV)
 		return;
 
 	if (strcmp(name, TUNNAME) == 0) {
-		r = rman_reserve_resource(&tununits, 0, IF_MAXUNIT, 1,
-		    RF_ALLOCATED | RF_ACTIVE, NULL);
-		u = rman_get_start(r);
-		err = rman_release_resource(r);
-		KASSERT(err == 0, ("Unexpected failure releasing resource"));
-		*dev = makedev(CDEV_MAJOR, unit2minor(u));
-		if ((*dev)->si_flags & SI_NAMED)
-			return;	/* Already make_dev()d */
+		u = -1;
 	} else if (dev_stdclone(name, NULL, TUNNAME, &u) != 1)
 		return;	/* Don't recognise the name */
-
-	*dev = make_dev(&tun_cdevsw, unit2minor(u),
-	    UID_ROOT, GID_WHEEL, 0600, "tun%d", u);
-
-	/*
-	 * All devices depend on tunbasedev so that we can simply
-	 * destroy_dev() this device at module unload time to get
-	 * rid of all our make_dev()d resources.
-	 */
-	if (tunbasedev == NOUDEV)
-		tunbasedev = (*dev)->si_udev;
-	else {
-		(*dev)->si_flags |= SI_CHEAPCLONE;
-		dev_depends(udev2dev(tunbasedev, 0), *dev);
+	if (u != -1 && u > IF_MAXUNIT)
+		return;	/* Unit number too high */
+
+	/* find any existing device, or allocate new unit number */
+	i = clone_create(&tunclones, &tun_cdevsw, &u, dev, 0);
+	if (i) {
+		/* No preexisting dev_t, create one */
+		*dev = make_dev(&tun_cdevsw, unit2minor(u),
+		    UID_UUCP, GID_DIALER, 0600, "tun%d", u);
+		if (*dev != NULL)
+			(*dev)->si_flags |= SI_CHEAPCLONE;
 	}
 }
 
@@ -138,57 +146,29 @@ tunmodevent(module_t mod, int type, void *data)
 	static eventhandler_tag tag;
 	struct tun_softc *tp;
 	dev_t dev;
-	int err;
 
 	switch (type) {
 	case MOD_LOAD:
 		tag = EVENTHANDLER_REGISTER(dev_clone, tunclone, 0, 1000);
 		if (tag == NULL)
 			return (ENOMEM);
-		tununits.rm_type = RMAN_ARRAY;
-		tununits.rm_descr = "open if_tun units";
-		err = rman_init(&tununits);
-		if (err != 0) {
-			EVENTHANDLER_DEREGISTER(dev_clone, tag);
-			return (err);
-		}
-		err = rman_manage_region(&tununits, 0, IF_MAXUNIT);
-		if (err != 0) {
-			printf("%s: tununits: rman_manage_region: Failed %d\n",
-			    TUNNAME, err);
-			rman_fini(&tununits);
-			EVENTHANDLER_DEREGISTER(dev_clone, tag);
-			return (err);
-		}
 		break;
 	case MOD_UNLOAD:
-		err = rman_fini(&tununits);
-		if (err != 0)
-			return (err);
 		EVENTHANDLER_DEREGISTER(dev_clone, tag);
 
-		while (tunhead != NULL) {
-			KASSERT((tunhead->tun_flags & TUN_OPEN) == 0,
+		while (!TAILQ_EMPTY(&tunhead)) {
+			tp = TAILQ_FIRST(&tunhead);
+			KASSERT((tp->tun_flags & TUN_OPEN) == 0,
 			    ("tununits is out of sync - unit %d",
-			    tunhead->tun_if.if_dunit));
-			tp = tunhead;
-			dev = makedev(tun_cdevsw.d_maj,
-			    unit2minor(tp->tun_if.if_dunit));
-			KASSERT(dev->si_drv1 == tp, ("Bad makedev result"));
-			tunhead = tp->next;
+			    tp->tun_if.if_dunit));
+			TAILQ_REMOVE(&tunhead, tp, tun_list);
+			dev = tp->tun_dev;
 			bpfdetach(&tp->tun_if);
 			if_detach(&tp->tun_if);
-			KASSERT(dev->si_flags & SI_NAMED, ("Missing make_dev"));
+			destroy_dev(dev);
 			free(tp, M_TUN);
 		}
-
-		/*
-		 * Destroying tunbasedev results in all of our make_dev()s
-		 * conveniently going away.
-		 */
-		if (tunbasedev != NOUDEV)
-			destroy_dev(udev2dev(tunbasedev, 0));
-
+		clone_cleanup(&tunclones);
 		break;
 	}
 	return 0;
@@ -222,14 +202,12 @@ tuncreate(dev_t dev)
 	struct tun_softc *sc;
 	struct ifnet *ifp;
 
-	if (!(dev->si_flags & SI_NAMED))
-		dev = make_dev(&tun_cdevsw, minor(dev),
-		    UID_UUCP, GID_DIALER, 0600, "tun%d", dev2unit(dev));
+	dev->si_flags &= ~SI_CHEAPCLONE;
 
 	MALLOC(sc, struct tun_softc *, sizeof(*sc), M_TUN, M_WAITOK | M_ZERO);
 	sc->tun_flags = TUN_INITED;
-	sc->next = tunhead;
-	tunhead = sc;
+	sc->tun_dev = dev;
+	TAILQ_INSERT_TAIL(&tunhead, sc, tun_list);
 
 	ifp = &sc->tun_if;
 	if_initname(ifp, TUNNAME, dev2unit(dev));
@@ -249,32 +227,21 @@ tuncreate(dev_t dev)
 static int
 tunopen(dev_t dev, int flag, int mode, struct thread *td)
 {
-	struct resource *r;
 	struct ifnet	*ifp;
 	struct tun_softc *tp;
-	int unit;
-
-	unit = dev2unit(dev);
-	if (unit > IF_MAXUNIT)
-		return (ENXIO);
-
-	r = rman_reserve_resource(&tununits, unit, unit, 1,
-	    RF_ALLOCATED | RF_ACTIVE, NULL);
-	if (r == NULL)
-		return (EBUSY);
-
-	dev->si_flags &= ~SI_CHEAPCLONE;
 
 	tp = dev->si_drv1;
 	if (!tp) {
 		tuncreate(dev);
 		tp = dev->si_drv1;
 	}
-	KASSERT(!(tp->tun_flags & TUN_OPEN), ("Resource & flags out-of-sync"));
-	tp->tun_unit = r;
-	tp->tun_pid = td->td_proc->p_pid;
-	ifp = &tp->tun_if;
+
+	if (tp->tun_proc != NULL && tp->tun_proc != td->td_proc)
+		return (EBUSY);
+	tp->tun_proc = td->td_proc;
+
 	tp->tun_flags |= TUN_OPEN;
+	ifp = &tp->tun_if;
 	TUNDEBUG(ifp, "open\n");
 
 	return (0);
@@ -290,14 +257,12 @@ tunclose(dev_t dev, int foo, int bar, struct thread *td)
 	struct tun_softc *tp;
 	struct ifnet *ifp;
 	int s;
-	int err;
 
 	tp = dev->si_drv1;
 	ifp = &tp->tun_if;
 
-	KASSERT(tp->tun_unit, ("Unit %d not marked open", tp->tun_if.if_dunit));
 	tp->tun_flags &= ~TUN_OPEN;
-	tp->tun_pid = 0;
+	tp->tun_proc = NULL;
 
 	/*
 	 * junk all pending output
@@ -325,11 +290,7 @@ tunclose(dev_t dev, int foo, int bar, struct thread *td)
 
 	funsetown(&tp->tun_sigio);
 	selwakeuppri(&tp->tun_rsel, PZERO + 1);
-
 	TUNDEBUG (ifp, "closed\n");
-	err = rman_release_resource(tp->tun_unit);
-	KASSERT(err == 0, ("Unit %d failed to release", tp->tun_if.if_dunit));
-
 	return (0);
 }
 
@@ -384,9 +345,9 @@ tunifioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
 	switch(cmd) {
 	case SIOCGIFSTATUS:
 		ifs = (struct ifstat *)data;
-		if (tp->tun_pid)
+		if (tp->tun_proc)
 			sprintf(ifs->ascii + strlen(ifs->ascii),
-			    "\tOpened by PID %d\n", tp->tun_pid);
+			    "\tOpened by PID %d\n", tp->tun_proc->p_pid);
 		break;
 	case SIOCSIFADDR:
 		error = tuninit(ifp);
@@ -573,7 +534,7 @@ tunioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct thread *td)
 		}
 		break;
 	case TUNSIFPID:
-		tp->tun_pid = curthread->td_proc->p_pid;
+		tp->tun_proc = curthread->td_proc;
 		break;
 	case FIONBIO:
 		break;
diff --git a/sys/net/if_tunvar.h b/sys/net/if_tunvar.h
deleted file mode 100644
index cda53f0..0000000
--- a/sys/net/if_tunvar.h
+++ /dev/null
@@ -1,55 +0,0 @@
-/*-
- * Copyright (c) 1998 Brian Somers <brian@Awfulhak.org>
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- *    notice, this list of conditions and the following disclaimer.
- * 2. 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.
- *
- * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
- *
- * $FreeBSD$
- */
-
-#ifndef _NET_IF_TUNVAR_H_
-#define _NET_IF_TUNVAR_H_
-
-struct tun_softc {
-	u_short	tun_flags;		/* misc flags */
-#define	TUN_OPEN	0x0001
-#define	TUN_INITED	0x0002
-#define	TUN_RCOLL	0x0004
-#define	TUN_IASET	0x0008
-#define	TUN_DSTADDR	0x0010
-#define	TUN_LMODE	0x0020
-#define	TUN_RWAIT	0x0040
-#define	TUN_ASYNC	0x0080
-#define	TUN_IFHEAD	0x0100
-
-#define TUN_READY       (TUN_OPEN | TUN_INITED)
-
-	pid_t	tun_pid;		/* PID of process to open */
-	struct	ifnet tun_if;		/* the interface */
-	struct  sigio *tun_sigio;	/* information for async I/O */
-	struct	selinfo	tun_rsel;	/* read select */
-
-	struct	tun_softc *next;	/* Next softc in list */
-	struct	resource *tun_unit;	/* resource allocated for this unit */
-};
-
-#endif /* !_NET_IF_TUNVAR_H_ */
diff --git a/sys/sys/conf.h b/sys/sys/conf.h
index fb39f08..a203c11 100644
--- a/sys/sys/conf.h
+++ b/sys/sys/conf.h
@@ -64,10 +64,12 @@ struct cdev {
 #define SI_CONSOPEN	0x0040	/* opened by console */
 #define SI_DUMPDEV	0x0080	/* is kernel dumpdev */
 #define SI_CANDELETE	0x0100	/* can do BIO_DELETE */
+#define SI_CLONELIST	0x0200	/* on a clone list */
 	struct timespec	si_atime;
 	struct timespec	si_ctime;
 	struct timespec	si_mtime;
 	udev_t		si_udev;
+	LIST_ENTRY(cdev)	si_clone;
 	LIST_ENTRY(cdev)	si_hash;
 	SLIST_HEAD(, vnode)	si_hlist;
 	LIST_HEAD(, cdev)	si_children;
@@ -125,6 +127,7 @@ struct buf;
 struct thread;
 struct uio;
 struct knote;
+struct clonedevs;
 
 /*
  * Note: d_thread_t is provided as a transition aid for those drivers
@@ -198,6 +201,7 @@ typedef int dumper_t(
 #define	D_NAGGED	0x00020000	/* nagged about missing make_dev() */
 #define	D_TRACKCLOSE	0x00080000	/* track all closes */
 #define D_MMAP_ANON	0x00100000	/* special treatment in vm_mmap.c */
+#define D_PSEUDO	0x00200000	/* make_dev() can return NULL */
 #define D_NOGIANT	0x00400000	/* Doesn't want Giant */
 
 /*
@@ -274,6 +278,11 @@ static moduledata_t name##_mod = {					\
 DECLARE_MODULE(name, name##_mod, SI_SUB_DRIVERS, SI_ORDER_MIDDLE)
 
 
+void clone_cleanup(struct clonedevs **);
+#define CLONE_UNITMASK 0xfffff
+#define CLONE_FLAG0 (CLONE_UNITMASK + 1)
+int clone_create(struct clonedevs **, struct cdevsw *, int *unit, dev_t *dev, u_int extra);
+
 int	count_dev(dev_t _dev);
 void	destroy_dev(dev_t _dev);
 struct cdevsw *devsw(dev_t _dev);
diff --git a/sys/sys/linedisc.h b/sys/sys/linedisc.h
index fb39f08..a203c11 100644
--- a/sys/sys/linedisc.h
+++ b/sys/sys/linedisc.h
@@ -64,10 +64,12 @@ struct cdev {
 #define SI_CONSOPEN	0x0040	/* opened by console */
 #define SI_DUMPDEV	0x0080	/* is kernel dumpdev */
 #define SI_CANDELETE	0x0100	/* can do BIO_DELETE */
+#define SI_CLONELIST	0x0200	/* on a clone list */
 	struct timespec	si_atime;
 	struct timespec	si_ctime;
 	struct timespec	si_mtime;
 	udev_t		si_udev;
+	LIST_ENTRY(cdev)	si_clone;
 	LIST_ENTRY(cdev)	si_hash;
 	SLIST_HEAD(, vnode)	si_hlist;
 	LIST_HEAD(, cdev)	si_children;
@@ -125,6 +127,7 @@ struct buf;
 struct thread;
 struct uio;
 struct knote;
+struct clonedevs;
 
 /*
  * Note: d_thread_t is provided as a transition aid for those drivers
@@ -198,6 +201,7 @@ typedef int dumper_t(
 #define	D_NAGGED	0x00020000	/* nagged about missing make_dev() */
 #define	D_TRACKCLOSE	0x00080000	/* track all closes */
 #define D_MMAP_ANON	0x00100000	/* special treatment in vm_mmap.c */
+#define D_PSEUDO	0x00200000	/* make_dev() can return NULL */
 #define D_NOGIANT	0x00400000	/* Doesn't want Giant */
 
 /*
@@ -274,6 +278,11 @@ static moduledata_t name##_mod = {					\
 DECLARE_MODULE(name, name##_mod, SI_SUB_DRIVERS, SI_ORDER_MIDDLE)
 
 
+void clone_cleanup(struct clonedevs **);
+#define CLONE_UNITMASK 0xfffff
+#define CLONE_FLAG0 (CLONE_UNITMASK + 1)
+int clone_create(struct clonedevs **, struct cdevsw *, int *unit, dev_t *dev, u_int extra);
+
 int	count_dev(dev_t _dev);
 void	destroy_dev(dev_t _dev);
 struct cdevsw *devsw(dev_t _dev);