xref: /src/sys/kern/kern_subr.c

/*	$NetBSD: kern_subr.c,v 1.228 2020/01/01 22:57:17 thorpej Exp $	*/

/*-
 * Copyright (c) 1997, 1998, 1999, 2002, 2007, 2008 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
 * NASA Ames Research Center, and by Luke Mewburn.
 *
 * 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 NETBSD FOUNDATION, INC. 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 FOUNDATION OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

/*
 * Copyright (c) 1982, 1986, 1991, 1993
 *	The Regents of the University of California.  All rights reserved.
 * (c) UNIX System Laboratories, Inc.
 * All or some portions of this file are derived from material licensed
 * to the University of California by American Telephone and Telegraph
 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
 * the permission of UNIX System Laboratories, Inc.
 *
 * Copyright (c) 1992, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * This software was developed by the Computer Systems Engineering group
 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
 * contributed to Berkeley.
 *
 * All advertising materials mentioning features or use of this software
 * must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Lawrence Berkeley Laboratory.
 *
 * 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.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
 *
 *	@(#)kern_subr.c	8.4 (Berkeley) 2/14/95
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: kern_subr.c,v 1.228 2020/01/01 22:57:17 thorpej Exp $");

#include "opt_ddb.h"
#include "opt_md.h"
#include "opt_tftproot.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/mount.h>
#include <sys/device.h>
#include <sys/reboot.h>
#include <sys/conf.h>
#include <sys/disk.h>
#include <sys/disklabel.h>
#include <sys/queue.h>
#include <sys/fcntl.h>
#include <sys/kauth.h>
#include <sys/stat.h>
#include <sys/vnode.h>
#include <sys/module.h>

#include <dev/cons.h>

#include <net/if.h>

/* XXX these should eventually move to subr_autoconf.c */
static device_t finddevice(const char *);
static device_t getdisk(const char *, int, int, dev_t *, int);
static device_t parsedisk(const char *, int, int, dev_t *);
static const char *getwedgename(const char *, int);

static void setroot_nfs(device_t);
static void setroot_md(device_t *);
static void setroot_ask(device_t, int);
static void setroot_root(device_t, int);
static void setroot_dump(device_t, device_t);


#ifdef TFTPROOT
int tftproot_dhcpboot(device_t);
#endif

dev_t	dumpcdev;	/* for savecore */

static int
isswap(device_t dv)
{
	struct dkwedge_info wi;
	struct vnode *vn;
	int error;

	if (device_class(dv) != DV_DISK || !device_is_a(dv, "dk"))
		return 0;

	if ((vn = opendisk(dv)) == NULL)
		return 0;

	error = VOP_IOCTL(vn, DIOCGWEDGEINFO, &wi, FREAD, NOCRED);
	VOP_CLOSE(vn, FREAD, NOCRED);
	vput(vn);
	if (error) {
#ifdef DEBUG_WEDGE
		printf("%s: Get wedge info returned %d\n", device_xname(dv), error);
#endif
		return 0;
	}
	return strcmp(wi.dkw_ptype, DKW_PTYPE_SWAP) == 0;
}

/*
 * Determine the root device and, if instructed to, the root file system.
 */

#ifdef MEMORY_DISK_IS_ROOT
int md_is_root = 1;
#else
int md_is_root = 0;
#endif

/*
 * The device and partition that we booted from.
 *
 * This data might be initialized by MD code, but is defined here.
 */
device_t booted_device;
const char *booted_method;
int booted_partition;
daddr_t booted_startblk;
uint64_t booted_nblks;
char *bootspec;

/*
 * Use partition letters if it's a disk class but not a wedge or flash.
 * XXX Check for wedge/flash is kinda gross.
 */
#define	DEV_USES_PARTITIONS(dv)						\
	(device_class((dv)) == DV_DISK &&				\
	 !device_is_a((dv), "dk") &&					\
	 !device_is_a((dv), "flash"))

void
setroot(device_t bootdv, int bootpartition)
{

	/*
	 * Let bootcode augment "rootspec", ensure that
	 * rootdev is invalid to avoid confusion.
	 */
	if (rootspec == NULL) {
		rootspec = bootspec;
		rootdev = NODEV;
	}

	/*
	 * force boot device to md0
	 */
	if (md_is_root)
		setroot_md(&bootdv);

#ifdef TFTPROOT
	/*
	 * XXX
	 * if rootspec specifies an interface
	 * sets root_device to that interface
	 * reuses NFS init code to set up network
	 * fetch image into ram disk
	 *
	 * if successful, we change boot device
	 */
	if (tftproot_dhcpboot(bootdv) == 0)
		setroot_md(&bootdv);
#endif

	/*
	 * quirk for
	 *  evbarm/mini2440
	 *  hpcarm
	 *  hpcmips
	 *  hpcsh
	 *
	 * if rootfstype is set to NFS and the
	 * kernel supports NFS and the boot device
	 * is unknown or not a network interface
 	 * -> chose the first network interface you find
	 *
	 * hp300 has similar MD code
	 */
	setroot_nfs(bootdv);

	/*
	 * If no bootdv was found by MD code and no
	 * root specified ask the user.
	 */
	if (rootspec == NULL && bootdv == NULL)
		boothowto |= RB_ASKNAME;

	/*
	 * loop until a root device is specified
	 */
	do {
		if (boothowto & RB_ASKNAME)
			setroot_ask(bootdv, bootpartition);
		else
			setroot_root(bootdv, bootpartition);

		if (root_device == NULL)
			boothowto |= RB_ASKNAME;
	} while (root_device == NULL);
}

/*
 * If NFS is specified as the file system, and we found
 * a DV_DISK boot device (or no boot device at all), then
 * find a reasonable network interface for "rootspec".
 */
static void
setroot_nfs(device_t dv)
{
	struct vfsops *vops;
	struct ifnet *ifp;

	vops = vfs_getopsbyname(MOUNT_NFS);
	if (vops != NULL && strcmp(rootfstype, MOUNT_NFS) == 0 &&
	    rootspec == NULL &&
	    (dv == NULL || device_class(dv) != DV_IFNET)) {
		int s = pserialize_read_enter();
		IFNET_READER_FOREACH(ifp) {
			if ((ifp->if_flags &
			     (IFF_LOOPBACK|IFF_POINTOPOINT)) == 0)
				break;
		}
		if (ifp != NULL) {
			/*
			 * Have a suitable interface; behave as if
			 * the user specified this interface.
			 */
			rootspec = (const char *)ifp->if_xname;
		}
		pserialize_read_exit(s);
	}
	if (vops != NULL)
		vfs_delref(vops);
}

/*
 * Change boot device to md0
 *
 * md0 only exists when it is opened once.
 */
static void
setroot_md(device_t *dvp)
{
	int md_major;
	dev_t md_dev;

	md_major = devsw_name2blk("md", NULL, 0);
	if (md_major >= 0) {
		md_dev = MAKEDISKDEV(md_major, 0, RAW_PART);
		if (bdev_open(md_dev, FREAD, S_IFBLK, curlwp) == 0)
			*dvp = device_find_by_xname("md0");
	}
}

static void
setroot_ask(device_t bootdv, int bootpartition)
{
	device_t dv, defdumpdv, rootdv, dumpdv;
	dev_t nrootdev, ndumpdev;
	struct vfsops *vops;
	const char *deffsname;
	int len;
	char buf[128];

	for (;;) {
		printf("root device");
		if (bootdv != NULL) {
			printf(" (default %s", device_xname(bootdv));
			if (DEV_USES_PARTITIONS(bootdv))
				printf("%c", bootpartition + 'a');
			printf(")");
		}
		printf(": ");
		len = cngetsn(buf, sizeof(buf));
		if (len == 0 && bootdv != NULL) {
			strlcpy(buf, device_xname(bootdv), sizeof(buf));
			len = strlen(buf);
		}
		if (len > 0 && buf[len - 1] == '*') {
			buf[--len] = '\0';
			dv = getdisk(buf, len, 1, &nrootdev, 0);
			if (dv != NULL) {
				rootdv = dv;
				break;
			}
		}
		dv = getdisk(buf, len, bootpartition, &nrootdev, 0);
		if (dv != NULL) {
			rootdv = dv;
			break;
		}
	}
	rootdev = nrootdev;

	/*
	 * Set up the default dump device.  If root is on
	 * a network device or a disk without partitions,
	 * there is no default dump device.
	 */
	if (DEV_USES_PARTITIONS(rootdv) == 0)
		defdumpdv = NULL;
	else
		defdumpdv = rootdv;

	ndumpdev = NODEV;
	for (;;) {
		printf("dump device");
		if (defdumpdv != NULL) {
			/*
			 * Note, we know it's a disk if we get here.
			 */
			printf(" (default %sb)", device_xname(defdumpdv));
		}
		printf(": ");
		len = cngetsn(buf, sizeof(buf));
		if (len == 0) {
			if (defdumpdv != NULL) {
				ndumpdev = MAKEDISKDEV(major(nrootdev),
				    DISKUNIT(nrootdev), 1);
			}
			dumpdv = defdumpdv;
			break;
		}
		if (len == 4 && strcmp(buf, "none") == 0) {
			dumpdv = NULL;
			break;
		}
		dv = getdisk(buf, len, 1, &ndumpdev, 1);
		if (dv != NULL) {
			dumpdv = dv;
			break;
		}
	}
	dumpdev = ndumpdev;

	for (vops = LIST_FIRST(&vfs_list); vops != NULL;
	     vops = LIST_NEXT(vops, vfs_list)) {
		if (vops->vfs_mountroot != NULL &&
		    strcmp(rootfstype, vops->vfs_name) == 0)
		break;
	}

	if (vops == NULL) {
		deffsname = "generic";
	} else
		deffsname = vops->vfs_name;

	for (;;) {
		printf("file system (default %s): ", deffsname);
		len = cngetsn(buf, sizeof(buf));
		if (len == 0) {
			if (strcmp(deffsname, "generic") == 0)
				rootfstype = ROOT_FSTYPE_ANY;
			break;
		}
		if (len == 4 && strcmp(buf, "halt") == 0)
			kern_reboot(RB_HALT, NULL);
		else if (len == 6 && strcmp(buf, "reboot") == 0)
			kern_reboot(0, NULL);
#if defined(DDB)
		else if (len == 3 && strcmp(buf, "ddb") == 0) {
			console_debugger();
		}
#endif
		else if (len == 7 && strcmp(buf, "generic") == 0) {
			rootfstype = ROOT_FSTYPE_ANY;
			break;
		}
		vops = vfs_getopsbyname(buf);
		if (vops == NULL || vops->vfs_mountroot == NULL) {
			printf("use one of: generic");
			for (vops = LIST_FIRST(&vfs_list);
			     vops != NULL;
			     vops = LIST_NEXT(vops, vfs_list)) {
				if (vops->vfs_mountroot != NULL)
					printf(" %s", vops->vfs_name);
			}
			if (vops != NULL)
				vfs_delref(vops);
#if defined(DDB)
			printf(" ddb");
#endif
			printf(" halt reboot\n");
		} else {
			/*
			 * XXX If *vops gets freed between here and
			 * the call to mountroot(), rootfstype will
			 * point to something unexpected.  But in
			 * this case the system will fail anyway.
			 */
			rootfstype = vops->vfs_name;
			vfs_delref(vops);
			break;
		}
	}

	root_device = rootdv;
	setroot_dump(root_device, dumpdv);
}

/*
 * configure
 *   device_t root_device
 *   dev_t rootdev (for disks)
 *
 */
static void
setroot_root(device_t bootdv, int bootpartition)
{
	device_t rootdv;
	int majdev;
	const char *rootdevname;
	char buf[128];
	dev_t nrootdev;

	if (rootspec == NULL) {

		/*
		 * Wildcarded root; use the boot device.
		 */
		rootdv = bootdv;

		if (bootdv)
			majdev = devsw_name2blk(device_xname(bootdv), NULL, 0);
		else
			majdev = -1;
		if (majdev >= 0) {
			/*
			 * Root is on a disk.  `bootpartition' is root,
			 * unless the device does not use partitions.
			 */
			if (DEV_USES_PARTITIONS(bootdv))
				rootdev = MAKEDISKDEV(majdev,
						      device_unit(bootdv),
						      bootpartition);
			else
				rootdev = makedev(majdev, device_unit(bootdv));
		}
	} else {

		/*
		 * `root on <dev> ...'
		 */

		/*
		 * If rootspec can be parsed, just use it.
		 */
		rootdv = parsedisk(rootspec, strlen(rootspec), 0, &nrootdev);
		if (rootdv != NULL) {
			rootdev = nrootdev;
			goto haveroot;
		}

		/*
		 * Fall back to rootdev, compute rootdv for it
		 */
		rootdevname = devsw_blk2name(major(rootdev));
		if (rootdevname == NULL) {
			printf("unknown device major 0x%llx\n",
			    (unsigned long long)rootdev);
			return;
		}
		memset(buf, 0, sizeof(buf));
		snprintf(buf, sizeof(buf), "%s%llu", rootdevname,
		    (unsigned long long)DISKUNIT(rootdev));

		rootdv = finddevice(buf);
		if (rootdv == NULL) {
			printf("device %s (0x%llx) not configured\n",
			    buf, (unsigned long long)rootdev);
			return;
		}
	}

haveroot:
	switch (device_class(rootdv)) {
	case DV_IFNET:
	case DV_DISK:
		aprint_normal("root on %s", device_xname(rootdv));
		if (DEV_USES_PARTITIONS(rootdv))
			aprint_normal("%c", (int)DISKPART(rootdev) + 'a');
		break;
	default:
		printf("can't determine root device\n");
		return;
	}

	root_device = rootdv;
	setroot_dump(rootdv, NULL);
}

/*
 * configure
 *   dev_t dumpdev
 *   dev_t dumpcdev
 *
 * set to NODEV if device not found
 */
static void
setroot_dump(device_t rootdv, device_t dumpdv)
{
	device_t dv;
	deviter_t di;
	const char *dumpdevname;
	int majdev;
	char buf[128];

	/*
	 * Now configure the dump device.
	 *
	 * If we haven't figured out the dump device, do so, with
	 * the following rules:
	 *
	 *	(a) We already know dumpdv in the RB_ASKNAME case.
	 *
	 *	(b) If dumpspec is set, try to use it.  If the device
	 *	    is not available, punt.
	 *
	 *	(c) If dumpspec is not set, the dump device is
	 *	    wildcarded or unspecified.  If the root device
	 *	    is DV_IFNET, punt.  Otherwise, use partition b
	 *	    of the root device.
	 */

	if (boothowto & RB_ASKNAME) {		/* (a) */
		if (dumpdv == NULL)
			goto nodumpdev;
	} else if (dumpspec != NULL) {		/* (b) */
		if (strcmp(dumpspec, "none") == 0 || dumpdev == NODEV) {
			/*
			 * Operator doesn't want a dump device.
			 * Or looks like they tried to pick a network
			 * device.  Oops.
			 */
			goto nodumpdev;
		}

		dumpdevname = devsw_blk2name(major(dumpdev));
		if (dumpdevname == NULL)
			goto nodumpdev;
		memset(buf, 0, sizeof(buf));
		snprintf(buf, sizeof(buf), "%s%llu", dumpdevname,
		    (unsigned long long)DISKUNIT(dumpdev));

		dumpdv = finddevice(buf);
		if (dumpdv == NULL) {
			/*
			 * Device not configured.
			 */
			goto nodumpdev;
		}
	} else {				/* (c) */
		if (DEV_USES_PARTITIONS(rootdv) == 0) {
			for (dv = deviter_first(&di, DEVITER_F_ROOT_FIRST);
			     dv != NULL;
			     dv = deviter_next(&di))
				if (isswap(dv))
					break;
			deviter_release(&di);
			if (dv == NULL)
				goto nodumpdev;

			majdev = devsw_name2blk(device_xname(dv), NULL, 0);
			if (majdev < 0)
				goto nodumpdev;
			dumpdv = dv;
			dumpdev = makedev(majdev, device_unit(dumpdv));
		} else {
			dumpdv = rootdv;
			dumpdev = MAKEDISKDEV(major(rootdev),
			    device_unit(dumpdv), 1);
		}
	}

	dumpcdev = devsw_blk2chr(dumpdev);
	aprint_normal(" dumps on %s", device_xname(dumpdv));
	if (DEV_USES_PARTITIONS(dumpdv))
		aprint_normal("%c", (int)DISKPART(dumpdev) + 'a');
	aprint_normal("\n");
	return;

 nodumpdev:
	dumpdev = NODEV;
	dumpcdev = NODEV;
	aprint_normal("\n");
}

static device_t
finddevice(const char *name)
{
	const char *wname;

	if ((wname = getwedgename(name, strlen(name))) != NULL)
		return dkwedge_find_by_wname(wname);

	return device_find_by_xname(name);
}

static device_t
getdisk(const char *str, int len, int defpart, dev_t *devp, int isdump)
{
	device_t dv;
	deviter_t di;

	if (len == 4 && strcmp(str, "halt") == 0)
		kern_reboot(RB_HALT, NULL);
	else if (len == 6 && strcmp(str, "reboot") == 0)
		kern_reboot(0, NULL);
#if defined(DDB)
	else if (len == 3 && strcmp(str, "ddb") == 0) {
		console_debugger();
		return NULL;
	}
#endif

	if ((dv = parsedisk(str, len, defpart, devp)) == NULL) {
		printf("use one of:");
		for (dv = deviter_first(&di, DEVITER_F_ROOT_FIRST); dv != NULL;
		     dv = deviter_next(&di)) {
			if (DEV_USES_PARTITIONS(dv))
				printf(" %s[a-%c]", device_xname(dv),
				    'a' + MAXPARTITIONS - 1);
			else if (device_class(dv) == DV_DISK)
				printf(" %s", device_xname(dv));
			if (isdump == 0 && device_class(dv) == DV_IFNET)
				printf(" %s", device_xname(dv));
		}
		deviter_release(&di);
		dkwedge_print_wnames();
		if (isdump)
			printf(" none");
#if defined(DDB)
		printf(" ddb");
#endif
		printf(" halt reboot\n");
	}
	return dv;
}

static const char *
getwedgename(const char *name, int namelen)
{
	const char *wpfx1 = "wedge:";
	const char *wpfx2 = "NAME=";
	const int wpfx1len = strlen(wpfx1);
	const int wpfx2len = strlen(wpfx2);

	if (namelen > wpfx1len && strncmp(name, wpfx1, wpfx1len) == 0)
		return name + wpfx1len;

	if (namelen > wpfx2len && strncasecmp(name, wpfx2, wpfx2len) == 0)
		return name + wpfx2len;

	return NULL;
}

static device_t
parsedisk(const char *str, int len, int defpart, dev_t *devp)
{
	device_t dv;
	const char *wname;
	char c;
	int majdev, part;
	char xname[16]; /* same size as dv_xname */

	if (len == 0)
		return (NULL);

	if ((wname = getwedgename(str, len)) != NULL) {
		if ((dv = dkwedge_find_by_wname(wname)) == NULL)
			return NULL;
		part = defpart;
		goto gotdisk;
	}

	c = str[len-1];
	if (c >= 'a' && c <= ('a' + MAXPARTITIONS - 1)) {
		part = c - 'a';
		len--;
		if (len > sizeof(xname)-1)
			return NULL;
		memcpy(xname, str, len);
		xname[len] = '\0';
		str = xname;
	} else
		part = defpart;

	dv = finddevice(str);
	if (dv != NULL) {
		if (device_class(dv) == DV_DISK) {
 gotdisk:
			majdev = devsw_name2blk(device_xname(dv), NULL, 0);
			if (majdev < 0)
				panic("parsedisk");
			if (DEV_USES_PARTITIONS(dv))
				*devp = MAKEDISKDEV(majdev, device_unit(dv),
						    part);
			else
				*devp = makedev(majdev, device_unit(dv));
		}

		if (device_class(dv) == DV_IFNET)
			*devp = NODEV;
	}

	return (dv);
}