mirror_zfs/lib/libzfs/libzfs_util.c

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

/*
 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
 * Copyright (c) 2013, Joyent, Inc. All rights reserved.
 * Copyright (c) 2011, 2014 by Delphix. All rights reserved.
 * Copyright 2016 Igor Kozhukhov <ikozhukhov@gmail.com>
 */

/*
 * Internal utility routines for the ZFS library.
 */

#include <errno.h>
#include <fcntl.h>
#include <libintl.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <strings.h>
#include <unistd.h>
#include <ctype.h>
#include <math.h>
#include <sys/stat.h>
#include <sys/mnttab.h>
#include <sys/mntent.h>
#include <sys/types.h>
#include <sys/wait.h>

#include <libzfs.h>
#include <libzfs_core.h>

#include "libzfs_impl.h"
#include "zfs_prop.h"
#include "zfeature_common.h"
#include <zfs_fletcher.h>

int
libzfs_errno(libzfs_handle_t *hdl)
{
	return (hdl->libzfs_error);
}

const char *
libzfs_error_init(int error)
{
	switch (error) {
	case ENXIO:
		return (dgettext(TEXT_DOMAIN, "The ZFS modules are not "
		    "loaded.\nTry running '/sbin/modprobe zfs' as root "
		    "to load them.\n"));
	case ENOENT:
		return (dgettext(TEXT_DOMAIN, "/dev/zfs and /proc/self/mounts "
		    "are required.\nTry running 'udevadm trigger' and 'mount "
		    "-t proc proc /proc' as root.\n"));
	case ENOEXEC:
		return (dgettext(TEXT_DOMAIN, "The ZFS modules cannot be "
		    "auto-loaded.\nTry running '/sbin/modprobe zfs' as "
		    "root to manually load them.\n"));
	case EACCES:
		return (dgettext(TEXT_DOMAIN, "Permission denied the "
		    "ZFS utilities must be run as root.\n"));
	default:
		return (dgettext(TEXT_DOMAIN, "Failed to initialize the "
		    "libzfs library.\n"));
	}
}

const char *
libzfs_error_action(libzfs_handle_t *hdl)
{
	return (hdl->libzfs_action);
}

const char *
libzfs_error_description(libzfs_handle_t *hdl)
{
	if (hdl->libzfs_desc[0] != '\0')
		return (hdl->libzfs_desc);

	switch (hdl->libzfs_error) {
	case EZFS_NOMEM:
		return (dgettext(TEXT_DOMAIN, "out of memory"));
	case EZFS_BADPROP:
		return (dgettext(TEXT_DOMAIN, "invalid property value"));
	case EZFS_PROPREADONLY:
		return (dgettext(TEXT_DOMAIN, "read-only property"));
	case EZFS_PROPTYPE:
		return (dgettext(TEXT_DOMAIN, "property doesn't apply to "
		    "datasets of this type"));
	case EZFS_PROPNONINHERIT:
		return (dgettext(TEXT_DOMAIN, "property cannot be inherited"));
	case EZFS_PROPSPACE:
		return (dgettext(TEXT_DOMAIN, "invalid quota or reservation"));
	case EZFS_BADTYPE:
		return (dgettext(TEXT_DOMAIN, "operation not applicable to "
		    "datasets of this type"));
	case EZFS_BUSY:
		return (dgettext(TEXT_DOMAIN, "pool or dataset is busy"));
	case EZFS_EXISTS:
		return (dgettext(TEXT_DOMAIN, "pool or dataset exists"));
	case EZFS_NOENT:
		return (dgettext(TEXT_DOMAIN, "no such pool or dataset"));
	case EZFS_BADSTREAM:
		return (dgettext(TEXT_DOMAIN, "invalid backup stream"));
	case EZFS_DSREADONLY:
		return (dgettext(TEXT_DOMAIN, "dataset is read-only"));
	case EZFS_VOLTOOBIG:
		return (dgettext(TEXT_DOMAIN, "volume size exceeds limit for "
		    "this system"));
	case EZFS_INVALIDNAME:
		return (dgettext(TEXT_DOMAIN, "invalid name"));
	case EZFS_BADRESTORE:
		return (dgettext(TEXT_DOMAIN, "unable to restore to "
		    "destination"));
	case EZFS_BADBACKUP:
		return (dgettext(TEXT_DOMAIN, "backup failed"));
	case EZFS_BADTARGET:
		return (dgettext(TEXT_DOMAIN, "invalid target vdev"));
	case EZFS_NODEVICE:
		return (dgettext(TEXT_DOMAIN, "no such device in pool"));
	case EZFS_BADDEV:
		return (dgettext(TEXT_DOMAIN, "invalid device"));
	case EZFS_NOREPLICAS:
		return (dgettext(TEXT_DOMAIN, "no valid replicas"));
	case EZFS_RESILVERING:
		return (dgettext(TEXT_DOMAIN, "currently resilvering"));
	case EZFS_BADVERSION:
		return (dgettext(TEXT_DOMAIN, "unsupported version or "
		    "feature"));
	case EZFS_POOLUNAVAIL:
		return (dgettext(TEXT_DOMAIN, "pool is unavailable"));
	case EZFS_DEVOVERFLOW:
		return (dgettext(TEXT_DOMAIN, "too many devices in one vdev"));
	case EZFS_BADPATH:
		return (dgettext(TEXT_DOMAIN, "must be an absolute path"));
	case EZFS_CROSSTARGET:
		return (dgettext(TEXT_DOMAIN, "operation crosses datasets or "
		    "pools"));
	case EZFS_ZONED:
		return (dgettext(TEXT_DOMAIN, "dataset in use by local zone"));
	case EZFS_MOUNTFAILED:
		return (dgettext(TEXT_DOMAIN, "mount failed"));
	case EZFS_UMOUNTFAILED:
		return (dgettext(TEXT_DOMAIN, "umount failed"));
	case EZFS_UNSHARENFSFAILED:
		return (dgettext(TEXT_DOMAIN, "unshare(1M) failed"));
	case EZFS_SHARENFSFAILED:
		return (dgettext(TEXT_DOMAIN, "share(1M) failed"));
	case EZFS_UNSHARESMBFAILED:
		return (dgettext(TEXT_DOMAIN, "smb remove share failed"));
	case EZFS_SHARESMBFAILED:
		return (dgettext(TEXT_DOMAIN, "smb add share failed"));
	case EZFS_PERM:
		return (dgettext(TEXT_DOMAIN, "permission denied"));
	case EZFS_NOSPC:
		return (dgettext(TEXT_DOMAIN, "out of space"));
	case EZFS_FAULT:
		return (dgettext(TEXT_DOMAIN, "bad address"));
	case EZFS_IO:
		return (dgettext(TEXT_DOMAIN, "I/O error"));
	case EZFS_INTR:
		return (dgettext(TEXT_DOMAIN, "signal received"));
	case EZFS_ISSPARE:
		return (dgettext(TEXT_DOMAIN, "device is reserved as a hot "
		    "spare"));
	case EZFS_INVALCONFIG:
		return (dgettext(TEXT_DOMAIN, "invalid vdev configuration"));
	case EZFS_RECURSIVE:
		return (dgettext(TEXT_DOMAIN, "recursive dataset dependency"));
	case EZFS_NOHISTORY:
		return (dgettext(TEXT_DOMAIN, "no history available"));
	case EZFS_POOLPROPS:
		return (dgettext(TEXT_DOMAIN, "failed to retrieve "
		    "pool properties"));
	case EZFS_POOL_NOTSUP:
		return (dgettext(TEXT_DOMAIN, "operation not supported "
		    "on this type of pool"));
	case EZFS_POOL_INVALARG:
		return (dgettext(TEXT_DOMAIN, "invalid argument for "
		    "this pool operation"));
	case EZFS_NAMETOOLONG:
		return (dgettext(TEXT_DOMAIN, "dataset name is too long"));
	case EZFS_OPENFAILED:
		return (dgettext(TEXT_DOMAIN, "open failed"));
	case EZFS_NOCAP:
		return (dgettext(TEXT_DOMAIN,
		    "disk capacity information could not be retrieved"));
	case EZFS_LABELFAILED:
		return (dgettext(TEXT_DOMAIN, "write of label failed"));
	case EZFS_BADWHO:
		return (dgettext(TEXT_DOMAIN, "invalid user/group"));
	case EZFS_BADPERM:
		return (dgettext(TEXT_DOMAIN, "invalid permission"));
	case EZFS_BADPERMSET:
		return (dgettext(TEXT_DOMAIN, "invalid permission set name"));
	case EZFS_NODELEGATION:
		return (dgettext(TEXT_DOMAIN, "delegated administration is "
		    "disabled on pool"));
	case EZFS_BADCACHE:
		return (dgettext(TEXT_DOMAIN, "invalid or missing cache file"));
	case EZFS_ISL2CACHE:
		return (dgettext(TEXT_DOMAIN, "device is in use as a cache"));
	case EZFS_VDEVNOTSUP:
		return (dgettext(TEXT_DOMAIN, "vdev specification is not "
		    "supported"));
	case EZFS_NOTSUP:
		return (dgettext(TEXT_DOMAIN, "operation not supported "
		    "on this dataset"));
	case EZFS_ACTIVE_SPARE:
		return (dgettext(TEXT_DOMAIN, "pool has active shared spare "
		    "device"));
	case EZFS_UNPLAYED_LOGS:
		return (dgettext(TEXT_DOMAIN, "log device has unplayed intent "
		    "logs"));
	case EZFS_REFTAG_RELE:
		return (dgettext(TEXT_DOMAIN, "no such tag on this dataset"));
	case EZFS_REFTAG_HOLD:
		return (dgettext(TEXT_DOMAIN, "tag already exists on this "
		    "dataset"));
	case EZFS_TAGTOOLONG:
		return (dgettext(TEXT_DOMAIN, "tag too long"));
	case EZFS_PIPEFAILED:
		return (dgettext(TEXT_DOMAIN, "pipe create failed"));
	case EZFS_THREADCREATEFAILED:
		return (dgettext(TEXT_DOMAIN, "thread create failed"));
	case EZFS_POSTSPLIT_ONLINE:
		return (dgettext(TEXT_DOMAIN, "disk was split from this pool "
		    "into a new one"));
	case EZFS_SCRUBBING:
		return (dgettext(TEXT_DOMAIN, "currently scrubbing; "
		    "use 'zpool scrub -s' to cancel current scrub"));
	case EZFS_NO_SCRUB:
		return (dgettext(TEXT_DOMAIN, "there is no active scrub"));
	case EZFS_DIFF:
		return (dgettext(TEXT_DOMAIN, "unable to generate diffs"));
	case EZFS_DIFFDATA:
		return (dgettext(TEXT_DOMAIN, "invalid diff data"));
	case EZFS_POOLREADONLY:
		return (dgettext(TEXT_DOMAIN, "pool is read-only"));
	case EZFS_UNKNOWN:
		return (dgettext(TEXT_DOMAIN, "unknown error"));
	default:
		assert(hdl->libzfs_error == 0);
		return (dgettext(TEXT_DOMAIN, "no error"));
	}
}

/*PRINTFLIKE2*/
void
zfs_error_aux(libzfs_handle_t *hdl, const char *fmt, ...)
{
	va_list ap;

	va_start(ap, fmt);

	(void) vsnprintf(hdl->libzfs_desc, sizeof (hdl->libzfs_desc),
	    fmt, ap);
	hdl->libzfs_desc_active = 1;

	va_end(ap);
}

static void
zfs_verror(libzfs_handle_t *hdl, int error, const char *fmt, va_list ap)
{
	(void) vsnprintf(hdl->libzfs_action, sizeof (hdl->libzfs_action),
	    fmt, ap);
	hdl->libzfs_error = error;

	if (hdl->libzfs_desc_active)
		hdl->libzfs_desc_active = 0;
	else
		hdl->libzfs_desc[0] = '\0';

	if (hdl->libzfs_printerr) {
		if (error == EZFS_UNKNOWN) {
			(void) fprintf(stderr, dgettext(TEXT_DOMAIN, "internal "
			    "error: %s\n"), libzfs_error_description(hdl));
			abort();
		}

		(void) fprintf(stderr, "%s: %s\n", hdl->libzfs_action,
		    libzfs_error_description(hdl));
		if (error == EZFS_NOMEM)
			exit(1);
	}
}

int
zfs_error(libzfs_handle_t *hdl, int error, const char *msg)
{
	return (zfs_error_fmt(hdl, error, "%s", msg));
}

/*PRINTFLIKE3*/
int
zfs_error_fmt(libzfs_handle_t *hdl, int error, const char *fmt, ...)
{
	va_list ap;

	va_start(ap, fmt);

	zfs_verror(hdl, error, fmt, ap);

	va_end(ap);

	return (-1);
}

static int
zfs_common_error(libzfs_handle_t *hdl, int error, const char *fmt,
    va_list ap)
{
	switch (error) {
	case EPERM:
	case EACCES:
		zfs_verror(hdl, EZFS_PERM, fmt, ap);
		return (-1);

	case ECANCELED:
		zfs_verror(hdl, EZFS_NODELEGATION, fmt, ap);
		return (-1);

	case EIO:
		zfs_verror(hdl, EZFS_IO, fmt, ap);
		return (-1);

	case EFAULT:
		zfs_verror(hdl, EZFS_FAULT, fmt, ap);
		return (-1);

	case EINTR:
		zfs_verror(hdl, EZFS_INTR, fmt, ap);
		return (-1);
	}

	return (0);
}

int
zfs_standard_error(libzfs_handle_t *hdl, int error, const char *msg)
{
	return (zfs_standard_error_fmt(hdl, error, "%s", msg));
}

/*PRINTFLIKE3*/
int
zfs_standard_error_fmt(libzfs_handle_t *hdl, int error, const char *fmt, ...)
{
	va_list ap;

	va_start(ap, fmt);

	if (zfs_common_error(hdl, error, fmt, ap) != 0) {
		va_end(ap);
		return (-1);
	}

	switch (error) {
	case ENXIO:
	case ENODEV:
	case EPIPE:
		zfs_verror(hdl, EZFS_IO, fmt, ap);
		break;

	case ENOENT:
		zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
		    "dataset does not exist"));
		zfs_verror(hdl, EZFS_NOENT, fmt, ap);
		break;

	case ENOSPC:
	case EDQUOT:
		zfs_verror(hdl, EZFS_NOSPC, fmt, ap);
		break;

	case EEXIST:
		zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
		    "dataset already exists"));
		zfs_verror(hdl, EZFS_EXISTS, fmt, ap);
		break;

	case EBUSY:
		zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
		    "dataset is busy"));
		zfs_verror(hdl, EZFS_BUSY, fmt, ap);
		break;
	case EROFS:
		zfs_verror(hdl, EZFS_POOLREADONLY, fmt, ap);
		break;
	case ENAMETOOLONG:
		zfs_verror(hdl, EZFS_NAMETOOLONG, fmt, ap);
		break;
	case ENOTSUP:
		zfs_verror(hdl, EZFS_BADVERSION, fmt, ap);
		break;
	case EAGAIN:
		zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
		    "pool I/O is currently suspended"));
		zfs_verror(hdl, EZFS_POOLUNAVAIL, fmt, ap);
		break;
	default:
		zfs_error_aux(hdl, strerror(error));
		zfs_verror(hdl, EZFS_UNKNOWN, fmt, ap);
		break;
	}

	va_end(ap);
	return (-1);
}

int
zpool_standard_error(libzfs_handle_t *hdl, int error, const char *msg)
{
	return (zpool_standard_error_fmt(hdl, error, "%s", msg));
}

/*PRINTFLIKE3*/
int
zpool_standard_error_fmt(libzfs_handle_t *hdl, int error, const char *fmt, ...)
{
	va_list ap;

	va_start(ap, fmt);

	if (zfs_common_error(hdl, error, fmt, ap) != 0) {
		va_end(ap);
		return (-1);
	}

	switch (error) {
	case ENODEV:
		zfs_verror(hdl, EZFS_NODEVICE, fmt, ap);
		break;

	case ENOENT:
		zfs_error_aux(hdl,
		    dgettext(TEXT_DOMAIN, "no such pool or dataset"));
		zfs_verror(hdl, EZFS_NOENT, fmt, ap);
		break;

	case EEXIST:
		zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
		    "pool already exists"));
		zfs_verror(hdl, EZFS_EXISTS, fmt, ap);
		break;

	case EBUSY:
		zfs_error_aux(hdl, dgettext(TEXT_DOMAIN, "pool is busy"));
		zfs_verror(hdl, EZFS_BUSY, fmt, ap);
		break;

	case ENXIO:
		zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
		    "one or more devices is currently unavailable"));
		zfs_verror(hdl, EZFS_BADDEV, fmt, ap);
		break;

	case ENAMETOOLONG:
		zfs_verror(hdl, EZFS_DEVOVERFLOW, fmt, ap);
		break;

	case ENOTSUP:
		zfs_verror(hdl, EZFS_POOL_NOTSUP, fmt, ap);
		break;

	case EINVAL:
		zfs_verror(hdl, EZFS_POOL_INVALARG, fmt, ap);
		break;

	case ENOSPC:
	case EDQUOT:
		zfs_verror(hdl, EZFS_NOSPC, fmt, ap);
		return (-1);

	case EAGAIN:
		zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
		    "pool I/O is currently suspended"));
		zfs_verror(hdl, EZFS_POOLUNAVAIL, fmt, ap);
		break;

	case EROFS:
		zfs_verror(hdl, EZFS_POOLREADONLY, fmt, ap);
		break;
	case EDOM:
		zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
		    "block size out of range or does not match"));
		zfs_verror(hdl, EZFS_BADPROP, fmt, ap);
		break;

	default:
		zfs_error_aux(hdl, strerror(error));
		zfs_verror(hdl, EZFS_UNKNOWN, fmt, ap);
	}

	va_end(ap);
	return (-1);
}

/*
 * Display an out of memory error message and abort the current program.
 */
int
no_memory(libzfs_handle_t *hdl)
{
	return (zfs_error(hdl, EZFS_NOMEM, "internal error"));
}

/*
 * A safe form of malloc() which will die if the allocation fails.
 */
void *
zfs_alloc(libzfs_handle_t *hdl, size_t size)
{
	void *data;

	if ((data = calloc(1, size)) == NULL)
		(void) no_memory(hdl);

	return (data);
}

/*
 * A safe form of asprintf() which will die if the allocation fails.
 */
/*PRINTFLIKE2*/
char *
zfs_asprintf(libzfs_handle_t *hdl, const char *fmt, ...)
{
	va_list ap;
	char *ret;
	int err;

	va_start(ap, fmt);

	err = vasprintf(&ret, fmt, ap);

	va_end(ap);

	if (err < 0)
		(void) no_memory(hdl);

	return (ret);
}

/*
 * A safe form of realloc(), which also zeroes newly allocated space.
 */
void *
zfs_realloc(libzfs_handle_t *hdl, void *ptr, size_t oldsize, size_t newsize)
{
	void *ret;

	if ((ret = realloc(ptr, newsize)) == NULL) {
		(void) no_memory(hdl);
		return (NULL);
	}

	bzero((char *)ret + oldsize, (newsize - oldsize));
	return (ret);
}

/*
 * A safe form of strdup() which will die if the allocation fails.
 */
char *
zfs_strdup(libzfs_handle_t *hdl, const char *str)
{
	char *ret;

	if ((ret = strdup(str)) == NULL)
		(void) no_memory(hdl);

	return (ret);
}

/*
 * Convert a number to an appropriately human-readable output.
 */
void
zfs_nicenum_format(uint64_t num, char *buf, size_t buflen,
    enum zfs_nicenum_format format)
{
	uint64_t n = num;
	int index = 0;
	const char *u;
	const char *units[3][7] = {
	    [ZFS_NICENUM_1024] = {"", "K", "M", "G", "T", "P", "E"},
	    [ZFS_NICENUM_BYTES] = {"B", "K", "M", "G", "T", "P", "E"},
	    [ZFS_NICENUM_TIME] = {"ns", "us", "ms", "s", "?", "?", "?"}
	};

	const int units_len[] = {[ZFS_NICENUM_1024] = 6,
	    [ZFS_NICENUM_BYTES] = 6,
	    [ZFS_NICENUM_TIME] = 4};

	const int k_unit[] = {	[ZFS_NICENUM_1024] = 1024,
	    [ZFS_NICENUM_BYTES] = 1024,
	    [ZFS_NICENUM_TIME] = 1000};

	double val;

	if (format == ZFS_NICENUM_RAW) {
		snprintf(buf, buflen, "%llu", (u_longlong_t)num);
		return;
	}


	while (n >= k_unit[format] && index < units_len[format]) {
		n /= k_unit[format];
		index++;
	}

	u = units[format][index];

	/* Don't print 0ns times */
	if ((format == ZFS_NICENUM_TIME) && (num == 0)) {
		(void) snprintf(buf, buflen, "-");
	} else if ((index == 0) || ((num %
	    (uint64_t)powl(k_unit[format], index)) == 0)) {
		/*
		 * If this is an even multiple of the base, always display
		 * without any decimal precision.
		 */
		(void) snprintf(buf, buflen, "%llu%s", (u_longlong_t)n, u);

	} else {
		/*
		 * We want to choose a precision that reflects the best choice
		 * for fitting in 5 characters.  This can get rather tricky when
		 * we have numbers that are very close to an order of magnitude.
		 * For example, when displaying 10239 (which is really 9.999K),
		 * we want only a single place of precision for 10.0K.  We could
		 * develop some complex heuristics for this, but it's much
		 * easier just to try each combination in turn.
		 */
		int i;
		for (i = 2; i >= 0; i--) {
			val = (double)num /
			    (uint64_t)powl(k_unit[format], index);

			/*
			 * Don't print floating point values for time.  Note,
			 * we use floor() instead of round() here, since
			 * round can result in undesirable results.  For
			 * example, if "num" is in the range of
			 * 999500-999999, it will print out "1000us".  This
			 * doesn't happen if we use floor().
			 */
			if (format == ZFS_NICENUM_TIME) {
				if (snprintf(buf, buflen, "%d%s",
				    (unsigned int) floor(val), u) <= 5)
					break;

			} else {
				if (snprintf(buf, buflen, "%.*f%s", i,
				    val, u) <= 5)
					break;
			}
		}
	}
}

/*
 * Convert a number to an appropriately human-readable output.
 */
void
zfs_nicenum(uint64_t num, char *buf, size_t buflen)
{
	zfs_nicenum_format(num, buf, buflen, ZFS_NICENUM_1024);
}

/*
 * Convert a time to an appropriately human-readable output.
 * @num:	Time in nanoseconds
 */
void
zfs_nicetime(uint64_t num, char *buf, size_t buflen)
{
	zfs_nicenum_format(num, buf, buflen, ZFS_NICENUM_TIME);
}

/*
 * Print out a raw number with correct column spacing
 */
void
zfs_niceraw(uint64_t num, char *buf, size_t buflen)
{
	zfs_nicenum_format(num, buf, buflen, ZFS_NICENUM_RAW);
}

/*
 * Convert a number of bytes to an appropriately human-readable output.
 */
void
zfs_nicebytes(uint64_t num, char *buf, size_t buflen)
{
	zfs_nicenum_format(num, buf, buflen, ZFS_NICENUM_BYTES);
}

void
libzfs_print_on_error(libzfs_handle_t *hdl, boolean_t printerr)
{
	hdl->libzfs_printerr = printerr;
}

static int
libzfs_module_loaded(const char *module)
{
	const char path_prefix[] = "/sys/module/";
	char path[256];

	memcpy(path, path_prefix, sizeof (path_prefix) - 1);
	strcpy(path + sizeof (path_prefix) - 1, module);

	return (access(path, F_OK) == 0);
}


/*
 * Read lines from an open file descriptor and store them in an array of
 * strings until EOF.  lines[] will be allocated and populated with all the
 * lines read.  All newlines are replaced with NULL terminators for
 * convenience.  lines[] must be freed after use with libzfs_free_str_array().
 *
 * Returns the number of lines read.
 */
static int
libzfs_read_stdout_from_fd(int fd, char **lines[])
{

	FILE *fp;
	int lines_cnt = 0;
	size_t len = 0;
	char *line = NULL;
	char **tmp_lines = NULL, **tmp;
	char *nl = NULL;
	int rc;

	fp = fdopen(fd, "r");
	if (fp == NULL)
		return (0);
	while (1) {
		rc = getline(&line, &len, fp);
		if (rc == -1)
			break;

		tmp = realloc(tmp_lines, sizeof (*tmp_lines) * (lines_cnt + 1));
		if (tmp == NULL) {
			/* Return the lines we were able to process */
			break;
		}
		tmp_lines = tmp;

		/* Terminate newlines */
		if ((nl = strchr(line, '\n')) != NULL)
			*nl = '\0';
		tmp_lines[lines_cnt] = line;
		lines_cnt++;
		line = NULL;
	}
	fclose(fp);
	*lines = tmp_lines;
	return (lines_cnt);
}

static int
libzfs_run_process_impl(const char *path, char *argv[], char *env[], int flags,
    char **lines[], int *lines_cnt)
{
	pid_t pid;
	int error, devnull_fd;
	int link[2];

	/*
	 * Setup a pipe between our child and parent process if we're
	 * reading stdout.
	 */
	if ((lines != NULL) && pipe(link) == -1)
		return (-ESTRPIPE);

	pid = vfork();
	if (pid == 0) {
		/* Child process */
		devnull_fd = open("/dev/null", O_WRONLY);

		if (devnull_fd < 0)
			_exit(-1);

		if (!(flags & STDOUT_VERBOSE) && (lines == NULL))
			(void) dup2(devnull_fd, STDOUT_FILENO);
		else if (lines != NULL) {
			/* Save the output to lines[] */
			dup2(link[1], STDOUT_FILENO);
			close(link[0]);
			close(link[1]);
		}

		if (!(flags & STDERR_VERBOSE))
			(void) dup2(devnull_fd, STDERR_FILENO);

		close(devnull_fd);

		if (flags & NO_DEFAULT_PATH) {
			if (env == NULL)
				execv(path, argv);
			else
				execve(path, argv, env);
		} else {
			if (env == NULL)
				execvp(path, argv);
			else
				execvpe(path, argv, env);
		}

		_exit(-1);
	} else if (pid > 0) {
		/* Parent process */
		int status;

		while ((error = waitpid(pid, &status, 0)) == -1 &&
		    errno == EINTR) { }
		if (error < 0 || !WIFEXITED(status))
			return (-1);

		if (lines != NULL) {
			close(link[1]);
			*lines_cnt = libzfs_read_stdout_from_fd(link[0], lines);
		}
		return (WEXITSTATUS(status));
	}

	return (-1);
}

int
libzfs_run_process(const char *path, char *argv[], int flags)
{
	return (libzfs_run_process_impl(path, argv, NULL, flags, NULL, NULL));
}

/*
 * Run a command and store its stdout lines in an array of strings (lines[]).
 * lines[] is allocated and populated for you, and the number of lines is set in
 * lines_cnt.  lines[] must be freed after use with libzfs_free_str_array().
 * All newlines (\n) in lines[] are terminated for convenience.
 */
int
libzfs_run_process_get_stdout(const char *path, char *argv[], char *env[],
    char **lines[], int *lines_cnt)
{
	return (libzfs_run_process_impl(path, argv, env, 0, lines, lines_cnt));
}

/*
 * Same as libzfs_run_process_get_stdout(), but run without $PATH set.  This
 * means that *path needs to be the full path to the executable.
 */
int
libzfs_run_process_get_stdout_nopath(const char *path, char *argv[],
    char *env[], char **lines[], int *lines_cnt)
{
	return (libzfs_run_process_impl(path, argv, env, NO_DEFAULT_PATH,
	    lines, lines_cnt));
}

/*
 * Free an array of strings.  Free both the strings contained in the array and
 * the array itself.
 */
void
libzfs_free_str_array(char **strs, int count)
{
	while (--count >= 0)
		free(strs[count]);

	free(strs);
}

/*
 * Returns 1 if environment variable is set to "YES", "yes", "ON", "on", or
 * a non-zero number.
 *
 * Returns 0 otherwise.
 */
int
libzfs_envvar_is_set(char *envvar)
{
	char *env = getenv(envvar);
	if (env && (strtoul(env, NULL, 0) > 0 ||
	    (!strncasecmp(env, "YES", 3) && strnlen(env, 4) == 3) ||
	    (!strncasecmp(env, "ON", 2) && strnlen(env, 3) == 2)))
		return (1);

	return (0);
}

/*
 * Verify the required ZFS_DEV device is available and optionally attempt
 * to load the ZFS modules.  Under normal circumstances the modules
 * should already have been loaded by some external mechanism.
 *
 * Environment variables:
 * - ZFS_MODULE_LOADING="YES|yes|ON|on" - Attempt to load modules.
 * - ZFS_MODULE_TIMEOUT="<seconds>"     - Seconds to wait for ZFS_DEV
 */
static int
libzfs_load_module(const char *module)
{
	char *argv[4] = {"/sbin/modprobe", "-q", (char *)module, (char *)0};
	char *load_str, *timeout_str;
	long timeout = 10; /* seconds */
	long busy_timeout = 10; /* milliseconds */
	int load = 0, fd;
	hrtime_t start;

	/* Optionally request module loading */
	if (!libzfs_module_loaded(module)) {
		load_str = getenv("ZFS_MODULE_LOADING");
		if (load_str) {
			if (!strncasecmp(load_str, "YES", strlen("YES")) ||
			    !strncasecmp(load_str, "ON", strlen("ON")))
				load = 1;
			else
				load = 0;
		}

		if (load && libzfs_run_process("/sbin/modprobe", argv, 0))
			return (ENOEXEC);
	}

	/* Module loading is synchronous it must be available */
	if (!libzfs_module_loaded(module))
		return (ENXIO);

	/*
	 * Device creation by udev is asynchronous and waiting may be
	 * required.  Busy wait for 10ms and then fall back to polling every
	 * 10ms for the allowed timeout (default 10s, max 10m).  This is
	 * done to optimize for the common case where the device is
	 * immediately available and to avoid penalizing the possible
	 * case where udev is slow or unable to create the device.
	 */
	timeout_str = getenv("ZFS_MODULE_TIMEOUT");
	if (timeout_str) {
		timeout = strtol(timeout_str, NULL, 0);
		timeout = MAX(MIN(timeout, (10 * 60)), 0); /* 0 <= N <= 600 */
	}

	start = gethrtime();
	do {
		fd = open(ZFS_DEV, O_RDWR);
		if (fd >= 0) {
			(void) close(fd);
			return (0);
		} else if (errno != ENOENT) {
			return (errno);
		} else if (NSEC2MSEC(gethrtime() - start) < busy_timeout) {
			sched_yield();
		} else {
			usleep(10 * MILLISEC);
		}
	} while (NSEC2MSEC(gethrtime() - start) < (timeout * MILLISEC));

	return (ENOENT);
}

libzfs_handle_t *
libzfs_init(void)
{
	libzfs_handle_t *hdl;
	int error;

	error = libzfs_load_module(ZFS_DRIVER);
	if (error) {
		errno = error;
		return (NULL);
	}

	if ((hdl = calloc(1, sizeof (libzfs_handle_t))) == NULL) {
		return (NULL);
	}

	if ((hdl->libzfs_fd = open(ZFS_DEV, O_RDWR)) < 0) {
		free(hdl);
		return (NULL);
	}

#ifdef HAVE_SETMNTENT
	if ((hdl->libzfs_mnttab = setmntent(MNTTAB, "r")) == NULL) {
#else
	if ((hdl->libzfs_mnttab = fopen(MNTTAB, "r")) == NULL) {
#endif
		(void) close(hdl->libzfs_fd);
		free(hdl);
		return (NULL);
	}

	hdl->libzfs_sharetab = fopen(ZFS_SHARETAB, "r");

	if (libzfs_core_init() != 0) {
		(void) close(hdl->libzfs_fd);
		(void) fclose(hdl->libzfs_mnttab);
		if (hdl->libzfs_sharetab)
			(void) fclose(hdl->libzfs_sharetab);
		free(hdl);
		return (NULL);
	}

	zfs_prop_init();
	zpool_prop_init();
	zpool_feature_init();
	libzfs_mnttab_init(hdl);
	fletcher_4_init();

	return (hdl);
}

void
libzfs_fini(libzfs_handle_t *hdl)
{
	(void) close(hdl->libzfs_fd);
	if (hdl->libzfs_mnttab)
#ifdef HAVE_SETMNTENT
		(void) endmntent(hdl->libzfs_mnttab);
#else
		(void) fclose(hdl->libzfs_mnttab);
#endif
	if (hdl->libzfs_sharetab)
		(void) fclose(hdl->libzfs_sharetab);
	zfs_uninit_libshare(hdl);
	zpool_free_handles(hdl);
	libzfs_fru_clear(hdl, B_TRUE);
	namespace_clear(hdl);
	libzfs_mnttab_fini(hdl);
	libzfs_core_fini();
	fletcher_4_fini();
	free(hdl);
}

libzfs_handle_t *
zpool_get_handle(zpool_handle_t *zhp)
{
	return (zhp->zpool_hdl);
}

libzfs_handle_t *
zfs_get_handle(zfs_handle_t *zhp)
{
	return (zhp->zfs_hdl);
}

zpool_handle_t *
zfs_get_pool_handle(const zfs_handle_t *zhp)
{
	return (zhp->zpool_hdl);
}

/*
 * Given a name, determine whether or not it's a valid path
 * (starts with '/' or "./").  If so, walk the mnttab trying
 * to match the device number.  If not, treat the path as an
 * fs/vol/snap/bkmark name.
 */
zfs_handle_t *
zfs_path_to_zhandle(libzfs_handle_t *hdl, char *path, zfs_type_t argtype)
{
	struct stat64 statbuf;
	struct extmnttab entry;
	int ret;

	if (path[0] != '/' && strncmp(path, "./", strlen("./")) != 0) {
		/*
		 * It's not a valid path, assume it's a name of type 'argtype'.
		 */
		return (zfs_open(hdl, path, argtype));
	}

	if (stat64(path, &statbuf) != 0) {
		(void) fprintf(stderr, "%s: %s\n", path, strerror(errno));
		return (NULL);
	}

	/* Reopen MNTTAB to prevent reading stale data from open file */
	if (freopen(MNTTAB, "r", hdl->libzfs_mnttab) == NULL)
		return (NULL);

	while ((ret = getextmntent(hdl->libzfs_mnttab, &entry, 0)) == 0) {
		if (makedevice(entry.mnt_major, entry.mnt_minor) ==
		    statbuf.st_dev) {
			break;
		}
	}
	if (ret != 0) {
		return (NULL);
	}

	if (strcmp(entry.mnt_fstype, MNTTYPE_ZFS) != 0) {
		(void) fprintf(stderr, gettext("'%s': not a ZFS filesystem\n"),
		    path);
		return (NULL);
	}

	return (zfs_open(hdl, entry.mnt_special, ZFS_TYPE_FILESYSTEM));
}

/*
 * Append partition suffix to an otherwise fully qualified device path.
 * This is used to generate the name the full path as its stored in
 * ZPOOL_CONFIG_PATH for whole disk devices.  On success the new length
 * of 'path' will be returned on error a negative value is returned.
 */
int
zfs_append_partition(char *path, size_t max_len)
{
	int len = strlen(path);

	if ((strncmp(path, UDISK_ROOT, strlen(UDISK_ROOT)) == 0) ||
	    (strncmp(path, ZVOL_ROOT, strlen(ZVOL_ROOT)) == 0)) {
		if (len + 6 >= max_len)
			return (-1);

		(void) strcat(path, "-part1");
		len += 6;
	} else {
		if (len + 2 >= max_len)
			return (-1);

		if (isdigit(path[len-1])) {
			(void) strcat(path, "p1");
			len += 2;
		} else {
			(void) strcat(path, "1");
			len += 1;
		}
	}

	return (len);
}

/*
 * Given a shorthand device name check if a file by that name exists in any
 * of the 'zpool_default_import_path' or ZPOOL_IMPORT_PATH directories.  If
 * one is found, store its fully qualified path in the 'path' buffer passed
 * by the caller and return 0, otherwise return an error.
 */
int
zfs_resolve_shortname(const char *name, char *path, size_t len)
{
	int i, error = -1;
	char *dir, *env, *envdup;

	env = getenv("ZPOOL_IMPORT_PATH");
	errno = ENOENT;

	if (env) {
		envdup = strdup(env);
		dir = strtok(envdup, ":");
		while (dir && error) {
			(void) snprintf(path, len, "%s/%s", dir, name);
			error = access(path, F_OK);
			dir = strtok(NULL, ":");
		}
		free(envdup);
	} else {
		for (i = 0; i < DEFAULT_IMPORT_PATH_SIZE && error < 0; i++) {
			(void) snprintf(path, len, "%s/%s",
			    zpool_default_import_path[i], name);
			error = access(path, F_OK);
		}
	}

	return (error ? ENOENT : 0);
}

/*
 * Given a shorthand device name look for a match against 'cmp_name'.  This
 * is done by checking all prefix expansions using either the default
 * 'zpool_default_import_paths' or the ZPOOL_IMPORT_PATH environment
 * variable.  Proper partition suffixes will be appended if this is a
 * whole disk.  When a match is found 0 is returned otherwise ENOENT.
 */
static int
zfs_strcmp_shortname(char *name, char *cmp_name, int wholedisk)
{
	int path_len, cmp_len, i = 0, error = ENOENT;
	char *dir, *env, *envdup = NULL;
	char path_name[MAXPATHLEN];

	cmp_len = strlen(cmp_name);
	env = getenv("ZPOOL_IMPORT_PATH");

	if (env) {
		envdup = strdup(env);
		dir = strtok(envdup, ":");
	} else {
		dir =  zpool_default_import_path[i];
	}

	while (dir) {
		/* Trim trailing directory slashes from ZPOOL_IMPORT_PATH */
		while (dir[strlen(dir)-1] == '/')
			dir[strlen(dir)-1] = '\0';

		path_len = snprintf(path_name, MAXPATHLEN, "%s/%s", dir, name);
		if (wholedisk)
			path_len = zfs_append_partition(path_name, MAXPATHLEN);

		if ((path_len == cmp_len) && strcmp(path_name, cmp_name) == 0) {
			error = 0;
			break;
		}

		if (env) {
			dir = strtok(NULL, ":");
		} else if (++i < DEFAULT_IMPORT_PATH_SIZE) {
			dir = zpool_default_import_path[i];
		} else {
			dir = NULL;
		}
	}

	if (env)
		free(envdup);

	return (error);
}

/*
 * Given either a shorthand or fully qualified path name look for a match
 * against 'cmp'.  The passed name will be expanded as needed for comparison
 * purposes and redundant slashes stripped to ensure an accurate match.
 */
int
zfs_strcmp_pathname(char *name, char *cmp, int wholedisk)
{
	int path_len, cmp_len;
	char path_name[MAXPATHLEN];
	char cmp_name[MAXPATHLEN];
	char *dir, *dup;

	/* Strip redundant slashes if one exists due to ZPOOL_IMPORT_PATH */
	memset(cmp_name, 0, MAXPATHLEN);
	dup = strdup(cmp);
	dir = strtok(dup, "/");
	while (dir) {
		strlcat(cmp_name, "/", sizeof (cmp_name));
		strlcat(cmp_name, dir, sizeof (cmp_name));
		dir = strtok(NULL, "/");
	}
	free(dup);

	if (name[0] != '/')
		return (zfs_strcmp_shortname(name, cmp_name, wholedisk));

	(void) strlcpy(path_name, name, MAXPATHLEN);
	path_len = strlen(path_name);
	cmp_len = strlen(cmp_name);

	if (wholedisk) {
		path_len = zfs_append_partition(path_name, MAXPATHLEN);
		if (path_len == -1)
			return (ENOMEM);
	}

	if ((path_len != cmp_len) || strcmp(path_name, cmp_name))
		return (ENOENT);

	return (0);
}

/*
 * Given a full path to a device determine if that device appears in the
 * import search path.  If it does return the first match and store the
 * index in the passed 'order' variable, otherwise return an error.
 */
int
zfs_path_order(char *name, int *order)
{
	int i = 0, error = ENOENT;
	char *dir, *env, *envdup;

	env = getenv("ZPOOL_IMPORT_PATH");
	if (env) {
		envdup = strdup(env);
		dir = strtok(envdup, ":");
		while (dir) {
			if (strncmp(name, dir, strlen(dir)) == 0) {
				*order = i;
				error = 0;
				break;
			}
			dir = strtok(NULL, ":");
			i++;
		}
		free(envdup);
	} else {
		for (i = 0; i < DEFAULT_IMPORT_PATH_SIZE; i++) {
			if (strncmp(name, zpool_default_import_path[i],
			    strlen(zpool_default_import_path[i])) == 0) {
				*order = i;
				error = 0;
				break;
			}
		}
	}

	return (error);
}

/*
 * Initialize the zc_nvlist_dst member to prepare for receiving an nvlist from
 * an ioctl().
 */
int
zcmd_alloc_dst_nvlist(libzfs_handle_t *hdl, zfs_cmd_t *zc, size_t len)
{
	if (len == 0)
		len = 16 * 1024;
	zc->zc_nvlist_dst_size = len;
	zc->zc_nvlist_dst =
	    (uint64_t)(uintptr_t)zfs_alloc(hdl, zc->zc_nvlist_dst_size);
	if (zc->zc_nvlist_dst == 0)
		return (-1);

	return (0);
}

/*
 * Called when an ioctl() which returns an nvlist fails with ENOMEM.  This will
 * expand the nvlist to the size specified in 'zc_nvlist_dst_size', which was
 * filled in by the kernel to indicate the actual required size.
 */
int
zcmd_expand_dst_nvlist(libzfs_handle_t *hdl, zfs_cmd_t *zc)
{
	free((void *)(uintptr_t)zc->zc_nvlist_dst);
	zc->zc_nvlist_dst =
	    (uint64_t)(uintptr_t)zfs_alloc(hdl, zc->zc_nvlist_dst_size);
	if (zc->zc_nvlist_dst == 0)
		return (-1);

	return (0);
}

/*
 * Called to free the src and dst nvlists stored in the command structure.
 */
void
zcmd_free_nvlists(zfs_cmd_t *zc)
{
	free((void *)(uintptr_t)zc->zc_nvlist_conf);
	free((void *)(uintptr_t)zc->zc_nvlist_src);
	free((void *)(uintptr_t)zc->zc_nvlist_dst);
	zc->zc_nvlist_conf = 0;
	zc->zc_nvlist_src = 0;
	zc->zc_nvlist_dst = 0;
}

static int
zcmd_write_nvlist_com(libzfs_handle_t *hdl, uint64_t *outnv, uint64_t *outlen,
    nvlist_t *nvl)
{
	char *packed;
	size_t len;

	verify(nvlist_size(nvl, &len, NV_ENCODE_NATIVE) == 0);

	if ((packed = zfs_alloc(hdl, len)) == NULL)
		return (-1);

	verify(nvlist_pack(nvl, &packed, &len, NV_ENCODE_NATIVE, 0) == 0);

	*outnv = (uint64_t)(uintptr_t)packed;
	*outlen = len;

	return (0);
}

int
zcmd_write_conf_nvlist(libzfs_handle_t *hdl, zfs_cmd_t *zc, nvlist_t *nvl)
{
	return (zcmd_write_nvlist_com(hdl, &zc->zc_nvlist_conf,
	    &zc->zc_nvlist_conf_size, nvl));
}

int
zcmd_write_src_nvlist(libzfs_handle_t *hdl, zfs_cmd_t *zc, nvlist_t *nvl)
{
	return (zcmd_write_nvlist_com(hdl, &zc->zc_nvlist_src,
	    &zc->zc_nvlist_src_size, nvl));
}

/*
 * Unpacks an nvlist from the ZFS ioctl command structure.
 */
int
zcmd_read_dst_nvlist(libzfs_handle_t *hdl, zfs_cmd_t *zc, nvlist_t **nvlp)
{
	if (nvlist_unpack((void *)(uintptr_t)zc->zc_nvlist_dst,
	    zc->zc_nvlist_dst_size, nvlp, 0) != 0)
		return (no_memory(hdl));

	return (0);
}

int
zfs_ioctl(libzfs_handle_t *hdl, int request, zfs_cmd_t *zc)
{
	return (ioctl(hdl->libzfs_fd, request, zc));
}

/*
 * ================================================================
 * API shared by zfs and zpool property management
 * ================================================================
 */

static void
zprop_print_headers(zprop_get_cbdata_t *cbp, zfs_type_t type)
{
	zprop_list_t *pl = cbp->cb_proplist;
	int i;
	char *title;
	size_t len;

	cbp->cb_first = B_FALSE;
	if (cbp->cb_scripted)
		return;

	/*
	 * Start with the length of the column headers.
	 */
	cbp->cb_colwidths[GET_COL_NAME] = strlen(dgettext(TEXT_DOMAIN, "NAME"));
	cbp->cb_colwidths[GET_COL_PROPERTY] = strlen(dgettext(TEXT_DOMAIN,
	    "PROPERTY"));
	cbp->cb_colwidths[GET_COL_VALUE] = strlen(dgettext(TEXT_DOMAIN,
	    "VALUE"));
	cbp->cb_colwidths[GET_COL_RECVD] = strlen(dgettext(TEXT_DOMAIN,
	    "RECEIVED"));
	cbp->cb_colwidths[GET_COL_SOURCE] = strlen(dgettext(TEXT_DOMAIN,
	    "SOURCE"));

	/* first property is always NAME */
	assert(cbp->cb_proplist->pl_prop ==
	    ((type == ZFS_TYPE_POOL) ?  ZPOOL_PROP_NAME : ZFS_PROP_NAME));

	/*
	 * Go through and calculate the widths for each column.  For the
	 * 'source' column, we kludge it up by taking the worst-case scenario of
	 * inheriting from the longest name.  This is acceptable because in the
	 * majority of cases 'SOURCE' is the last column displayed, and we don't
	 * use the width anyway.  Note that the 'VALUE' column can be oversized,
	 * if the name of the property is much longer than any values we find.
	 */
	for (pl = cbp->cb_proplist; pl != NULL; pl = pl->pl_next) {
		/*
		 * 'PROPERTY' column
		 */
		if (pl->pl_prop != ZPROP_INVAL) {
			const char *propname = (type == ZFS_TYPE_POOL) ?
			    zpool_prop_to_name(pl->pl_prop) :
			    zfs_prop_to_name(pl->pl_prop);

			len = strlen(propname);
			if (len > cbp->cb_colwidths[GET_COL_PROPERTY])
				cbp->cb_colwidths[GET_COL_PROPERTY] = len;
		} else {
			len = strlen(pl->pl_user_prop);
			if (len > cbp->cb_colwidths[GET_COL_PROPERTY])
				cbp->cb_colwidths[GET_COL_PROPERTY] = len;
		}

		/*
		 * 'VALUE' column.  The first property is always the 'name'
		 * property that was tacked on either by /sbin/zfs's
		 * zfs_do_get() or when calling zprop_expand_list(), so we
		 * ignore its width.  If the user specified the name property
		 * to display, then it will be later in the list in any case.
		 */
		if (pl != cbp->cb_proplist &&
		    pl->pl_width > cbp->cb_colwidths[GET_COL_VALUE])
			cbp->cb_colwidths[GET_COL_VALUE] = pl->pl_width;

		/* 'RECEIVED' column. */
		if (pl != cbp->cb_proplist &&
		    pl->pl_recvd_width > cbp->cb_colwidths[GET_COL_RECVD])
			cbp->cb_colwidths[GET_COL_RECVD] = pl->pl_recvd_width;

		/*
		 * 'NAME' and 'SOURCE' columns
		 */
		if (pl->pl_prop == (type == ZFS_TYPE_POOL ? ZPOOL_PROP_NAME :
		    ZFS_PROP_NAME) &&
		    pl->pl_width > cbp->cb_colwidths[GET_COL_NAME]) {
			cbp->cb_colwidths[GET_COL_NAME] = pl->pl_width;
			cbp->cb_colwidths[GET_COL_SOURCE] = pl->pl_width +
			    strlen(dgettext(TEXT_DOMAIN, "inherited from"));
		}
	}

	/*
	 * Now go through and print the headers.
	 */
	for (i = 0; i < ZFS_GET_NCOLS; i++) {
		switch (cbp->cb_columns[i]) {
		case GET_COL_NAME:
			title = dgettext(TEXT_DOMAIN, "NAME");
			break;
		case GET_COL_PROPERTY:
			title = dgettext(TEXT_DOMAIN, "PROPERTY");
			break;
		case GET_COL_VALUE:
			title = dgettext(TEXT_DOMAIN, "VALUE");
			break;
		case GET_COL_RECVD:
			title = dgettext(TEXT_DOMAIN, "RECEIVED");
			break;
		case GET_COL_SOURCE:
			title = dgettext(TEXT_DOMAIN, "SOURCE");
			break;
		default:
			title = NULL;
		}

		if (title != NULL) {
			if (i == (ZFS_GET_NCOLS - 1) ||
			    cbp->cb_columns[i + 1] == GET_COL_NONE)
				(void) printf("%s", title);
			else
				(void) printf("%-*s  ",
				    cbp->cb_colwidths[cbp->cb_columns[i]],
				    title);
		}
	}
	(void) printf("\n");
}

/*
 * Display a single line of output, according to the settings in the callback
 * structure.
 */
void
zprop_print_one_property(const char *name, zprop_get_cbdata_t *cbp,
    const char *propname, const char *value, zprop_source_t sourcetype,
    const char *source, const char *recvd_value)
{
	int i;
	const char *str = NULL;
	char buf[128];

	/*
	 * Ignore those source types that the user has chosen to ignore.
	 */
	if ((sourcetype & cbp->cb_sources) == 0)
		return;

	if (cbp->cb_first)
		zprop_print_headers(cbp, cbp->cb_type);

	for (i = 0; i < ZFS_GET_NCOLS; i++) {
		switch (cbp->cb_columns[i]) {
		case GET_COL_NAME:
			str = name;
			break;

		case GET_COL_PROPERTY:
			str = propname;
			break;

		case GET_COL_VALUE:
			str = value;
			break;

		case GET_COL_SOURCE:
			switch (sourcetype) {
			case ZPROP_SRC_NONE:
				str = "-";
				break;

			case ZPROP_SRC_DEFAULT:
				str = "default";
				break;

			case ZPROP_SRC_LOCAL:
				str = "local";
				break;

			case ZPROP_SRC_TEMPORARY:
				str = "temporary";
				break;

			case ZPROP_SRC_INHERITED:
				(void) snprintf(buf, sizeof (buf),
				    "inherited from %s", source);
				str = buf;
				break;
			case ZPROP_SRC_RECEIVED:
				str = "received";
				break;

			default:
				str = NULL;
				assert(!"unhandled zprop_source_t");
			}
			break;

		case GET_COL_RECVD:
			str = (recvd_value == NULL ? "-" : recvd_value);
			break;

		default:
			continue;
		}

		if (i == (ZFS_GET_NCOLS - 1) ||
		    cbp->cb_columns[i + 1] == GET_COL_NONE)
			(void) printf("%s", str);
		else if (cbp->cb_scripted)
			(void) printf("%s\t", str);
		else
			(void) printf("%-*s  ",
			    cbp->cb_colwidths[cbp->cb_columns[i]],
			    str);
	}

	(void) printf("\n");
}

/*
 * Given a numeric suffix, convert the value into a number of bits that the
 * resulting value must be shifted.
 */
static int
str2shift(libzfs_handle_t *hdl, const char *buf)
{
	const char *ends = "BKMGTPEZ";
	int i;

	if (buf[0] == '\0')
		return (0);
	for (i = 0; i < strlen(ends); i++) {
		if (toupper(buf[0]) == ends[i])
			break;
	}
	if (i == strlen(ends)) {
		if (hdl)
			zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
			    "invalid numeric suffix '%s'"), buf);
		return (-1);
	}

	/*
	 * Allow 'G' = 'GB' = 'GiB', case-insensitively.
	 * However, 'BB' and 'BiB' are disallowed.
	 */
	if (buf[1] == '\0' ||
	    (toupper(buf[0]) != 'B' &&
	    ((toupper(buf[1]) == 'B' && buf[2] == '\0') ||
	    (toupper(buf[1]) == 'I' && toupper(buf[2]) == 'B' &&
	    buf[3] == '\0'))))
		return (10 * i);

	if (hdl)
		zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
		    "invalid numeric suffix '%s'"), buf);
	return (-1);
}

/*
 * Convert a string of the form '100G' into a real number.  Used when setting
 * properties or creating a volume.  'buf' is used to place an extended error
 * message for the caller to use.
 */
int
zfs_nicestrtonum(libzfs_handle_t *hdl, const char *value, uint64_t *num)
{
	char *end;
	int shift;

	*num = 0;

	/* Check to see if this looks like a number.  */
	if ((value[0] < '0' || value[0] > '9') && value[0] != '.') {
		if (hdl)
			zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
			    "bad numeric value '%s'"), value);
		return (-1);
	}

	/* Rely on strtoull() to process the numeric portion.  */
	errno = 0;
	*num = strtoull(value, &end, 10);

	/*
	 * Check for ERANGE, which indicates that the value is too large to fit
	 * in a 64-bit value.
	 */
	if (errno == ERANGE) {
		if (hdl)
			zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
			    "numeric value is too large"));
		return (-1);
	}

	/*
	 * If we have a decimal value, then do the computation with floating
	 * point arithmetic.  Otherwise, use standard arithmetic.
	 */
	if (*end == '.') {
		double fval = strtod(value, &end);

		if ((shift = str2shift(hdl, end)) == -1)
			return (-1);

		fval *= pow(2, shift);

		if (fval > UINT64_MAX) {
			if (hdl)
				zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
				    "numeric value is too large"));
			return (-1);
		}

		*num = (uint64_t)fval;
	} else {
		if ((shift = str2shift(hdl, end)) == -1)
			return (-1);

		/* Check for overflow */
		if (shift >= 64 || (*num << shift) >> shift != *num) {
			if (hdl)
				zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
				    "numeric value is too large"));
			return (-1);
		}

		*num <<= shift;
	}

	return (0);
}

/*
 * Given a propname=value nvpair to set, parse any numeric properties
 * (index, boolean, etc) if they are specified as strings and add the
 * resulting nvpair to the returned nvlist.
 *
 * At the DSL layer, all properties are either 64-bit numbers or strings.
 * We want the user to be able to ignore this fact and specify properties
 * as native values (numbers, for example) or as strings (to simplify
 * command line utilities).  This also handles converting index types
 * (compression, checksum, etc) from strings to their on-disk index.
 */
int
zprop_parse_value(libzfs_handle_t *hdl, nvpair_t *elem, int prop,
    zfs_type_t type, nvlist_t *ret, char **svalp, uint64_t *ivalp,
    const char *errbuf)
{
	data_type_t datatype = nvpair_type(elem);
	zprop_type_t proptype;
	const char *propname;
	char *value;
	boolean_t isnone = B_FALSE;
	int err = 0;

	if (type == ZFS_TYPE_POOL) {
		proptype = zpool_prop_get_type(prop);
		propname = zpool_prop_to_name(prop);
	} else {
		proptype = zfs_prop_get_type(prop);
		propname = zfs_prop_to_name(prop);
	}

	/*
	 * Convert any properties to the internal DSL value types.
	 */
	*svalp = NULL;
	*ivalp = 0;

	switch (proptype) {
	case PROP_TYPE_STRING:
		if (datatype != DATA_TYPE_STRING) {
			zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
			    "'%s' must be a string"), nvpair_name(elem));
			goto error;
		}
		err = nvpair_value_string(elem, svalp);
		if (err != 0) {
			zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
			    "'%s' is invalid"), nvpair_name(elem));
			goto error;
		}
		if (strlen(*svalp) >= ZFS_MAXPROPLEN) {
			zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
			    "'%s' is too long"), nvpair_name(elem));
			goto error;
		}
		break;

	case PROP_TYPE_NUMBER:
		if (datatype == DATA_TYPE_STRING) {
			(void) nvpair_value_string(elem, &value);
			if (strcmp(value, "none") == 0) {
				isnone = B_TRUE;
			} else if (zfs_nicestrtonum(hdl, value, ivalp)
			    != 0) {
				goto error;
			}
		} else if (datatype == DATA_TYPE_UINT64) {
			(void) nvpair_value_uint64(elem, ivalp);
		} else {
			zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
			    "'%s' must be a number"), nvpair_name(elem));
			goto error;
		}

		/*
		 * Quota special: force 'none' and don't allow 0.
		 */
		if ((type & ZFS_TYPE_DATASET) && *ivalp == 0 && !isnone &&
		    (prop == ZFS_PROP_QUOTA || prop == ZFS_PROP_REFQUOTA)) {
			zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
			    "use 'none' to disable quota/refquota"));
			goto error;
		}

		/*
		 * Special handling for "*_limit=none". In this case it's not
		 * 0 but UINT64_MAX.
		 */
		if ((type & ZFS_TYPE_DATASET) && isnone &&
		    (prop == ZFS_PROP_FILESYSTEM_LIMIT ||
		    prop == ZFS_PROP_SNAPSHOT_LIMIT)) {
			*ivalp = UINT64_MAX;
		}
		break;

	case PROP_TYPE_INDEX:
		if (datatype != DATA_TYPE_STRING) {
			zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
			    "'%s' must be a string"), nvpair_name(elem));
			goto error;
		}

		(void) nvpair_value_string(elem, &value);

		if (zprop_string_to_index(prop, value, ivalp, type) != 0) {
			zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
			    "'%s' must be one of '%s'"), propname,
			    zprop_values(prop, type));
			goto error;
		}
		break;

	default:
		abort();
	}

	/*
	 * Add the result to our return set of properties.
	 */
	if (*svalp != NULL) {
		if (nvlist_add_string(ret, propname, *svalp) != 0) {
			(void) no_memory(hdl);
			return (-1);
		}
	} else {
		if (nvlist_add_uint64(ret, propname, *ivalp) != 0) {
			(void) no_memory(hdl);
			return (-1);
		}
	}

	return (0);
error:
	(void) zfs_error(hdl, EZFS_BADPROP, errbuf);
	return (-1);
}

static int
addlist(libzfs_handle_t *hdl, char *propname, zprop_list_t **listp,
    zfs_type_t type)
{
	int prop;
	zprop_list_t *entry;

	prop = zprop_name_to_prop(propname, type);

	if (prop != ZPROP_INVAL && !zprop_valid_for_type(prop, type, B_FALSE))
		prop = ZPROP_INVAL;

	/*
	 * When no property table entry can be found, return failure if
	 * this is a pool property or if this isn't a user-defined
	 * dataset property,
	 */
	if (prop == ZPROP_INVAL && ((type == ZFS_TYPE_POOL &&
	    !zpool_prop_feature(propname) &&
	    !zpool_prop_unsupported(propname)) ||
	    (type == ZFS_TYPE_DATASET && !zfs_prop_user(propname) &&
	    !zfs_prop_userquota(propname) && !zfs_prop_written(propname)))) {
		zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
		    "invalid property '%s'"), propname);
		return (zfs_error(hdl, EZFS_BADPROP,
		    dgettext(TEXT_DOMAIN, "bad property list")));
	}

	if ((entry = zfs_alloc(hdl, sizeof (zprop_list_t))) == NULL)
		return (-1);

	entry->pl_prop = prop;
	if (prop == ZPROP_INVAL) {
		if ((entry->pl_user_prop = zfs_strdup(hdl, propname)) ==
		    NULL) {
			free(entry);
			return (-1);
		}
		entry->pl_width = strlen(propname);
	} else {
		entry->pl_width = zprop_width(prop, &entry->pl_fixed,
		    type);
	}

	*listp = entry;

	return (0);
}

/*
 * Given a comma-separated list of properties, construct a property list
 * containing both user-defined and native properties.  This function will
 * return a NULL list if 'all' is specified, which can later be expanded
 * by zprop_expand_list().
 */
int
zprop_get_list(libzfs_handle_t *hdl, char *props, zprop_list_t **listp,
    zfs_type_t type)
{
	*listp = NULL;

	/*
	 * If 'all' is specified, return a NULL list.
	 */
	if (strcmp(props, "all") == 0)
		return (0);

	/*
	 * If no props were specified, return an error.
	 */
	if (props[0] == '\0') {
		zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
		    "no properties specified"));
		return (zfs_error(hdl, EZFS_BADPROP, dgettext(TEXT_DOMAIN,
		    "bad property list")));
	}

	/*
	 * It would be nice to use getsubopt() here, but the inclusion of column
	 * aliases makes this more effort than it's worth.
	 */
	while (*props != '\0') {
		size_t len;
		char *p;
		char c;

		if ((p = strchr(props, ',')) == NULL) {
			len = strlen(props);
			p = props + len;
		} else {
			len = p - props;
		}

		/*
		 * Check for empty options.
		 */
		if (len == 0) {
			zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
			    "empty property name"));
			return (zfs_error(hdl, EZFS_BADPROP,
			    dgettext(TEXT_DOMAIN, "bad property list")));
		}

		/*
		 * Check all regular property names.
		 */
		c = props[len];
		props[len] = '\0';

		if (strcmp(props, "space") == 0) {
			static char *spaceprops[] = {
				"name", "avail", "used", "usedbysnapshots",
				"usedbydataset", "usedbyrefreservation",
				"usedbychildren", NULL
			};
			int i;

			for (i = 0; spaceprops[i]; i++) {
				if (addlist(hdl, spaceprops[i], listp, type))
					return (-1);
				listp = &(*listp)->pl_next;
			}
		} else {
			if (addlist(hdl, props, listp, type))
				return (-1);
			listp = &(*listp)->pl_next;
		}

		props = p;
		if (c == ',')
			props++;
	}

	return (0);
}

void
zprop_free_list(zprop_list_t *pl)
{
	zprop_list_t *next;

	while (pl != NULL) {
		next = pl->pl_next;
		free(pl->pl_user_prop);
		free(pl);
		pl = next;
	}
}

typedef struct expand_data {
	zprop_list_t	**last;
	libzfs_handle_t	*hdl;
	zfs_type_t type;
} expand_data_t;

int
zprop_expand_list_cb(int prop, void *cb)
{
	zprop_list_t *entry;
	expand_data_t *edp = cb;

	if ((entry = zfs_alloc(edp->hdl, sizeof (zprop_list_t))) == NULL)
		return (ZPROP_INVAL);

	entry->pl_prop = prop;
	entry->pl_width = zprop_width(prop, &entry->pl_fixed, edp->type);
	entry->pl_all = B_TRUE;

	*(edp->last) = entry;
	edp->last = &entry->pl_next;

	return (ZPROP_CONT);
}

int
zprop_expand_list(libzfs_handle_t *hdl, zprop_list_t **plp, zfs_type_t type)
{
	zprop_list_t *entry;
	zprop_list_t **last;
	expand_data_t exp;

	if (*plp == NULL) {
		/*
		 * If this is the very first time we've been called for an 'all'
		 * specification, expand the list to include all native
		 * properties.
		 */
		last = plp;

		exp.last = last;
		exp.hdl = hdl;
		exp.type = type;

		if (zprop_iter_common(zprop_expand_list_cb, &exp, B_FALSE,
		    B_FALSE, type) == ZPROP_INVAL)
			return (-1);

		/*
		 * Add 'name' to the beginning of the list, which is handled
		 * specially.
		 */
		if ((entry = zfs_alloc(hdl, sizeof (zprop_list_t))) == NULL)
			return (-1);

		entry->pl_prop = (type == ZFS_TYPE_POOL) ?  ZPOOL_PROP_NAME :
		    ZFS_PROP_NAME;
		entry->pl_width = zprop_width(entry->pl_prop,
		    &entry->pl_fixed, type);
		entry->pl_all = B_TRUE;
		entry->pl_next = *plp;
		*plp = entry;
	}
	return (0);
}

int
zprop_iter(zprop_func func, void *cb, boolean_t show_all, boolean_t ordered,
    zfs_type_t type)
{
	return (zprop_iter_common(func, cb, show_all, ordered, type));
}