1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2015 Nexenta Systems, Inc.  All rights reserved.
24  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
25  * Copyright (c) 2014, 2015 by Delphix. All rights reserved.
26  * Copyright 2016 Igor Kozhukhov <ikozhukhov@gmail.com>
27  */
28 
29 /*
30  * Routines to manage ZFS mounts.  We separate all the nasty routines that have
31  * to deal with the OS.  The following functions are the main entry points --
32  * they are used by mount and unmount and when changing a filesystem's
33  * mountpoint.
34  *
35  * 	zfs_is_mounted()
36  * 	zfs_mount()
37  * 	zfs_unmount()
38  * 	zfs_unmountall()
39  *
40  * This file also contains the functions used to manage sharing filesystems via
41  * NFS and iSCSI:
42  *
43  * 	zfs_is_shared()
44  * 	zfs_share()
45  * 	zfs_unshare()
46  *
47  * 	zfs_is_shared_nfs()
48  * 	zfs_is_shared_smb()
49  * 	zfs_share_proto()
50  * 	zfs_shareall();
51  * 	zfs_unshare_nfs()
52  * 	zfs_unshare_smb()
53  * 	zfs_unshareall_nfs()
54  *	zfs_unshareall_smb()
55  *	zfs_unshareall()
56  *	zfs_unshareall_bypath()
57  *
58  * The following functions are available for pool consumers, and will
59  * mount/unmount and share/unshare all datasets within pool:
60  *
61  * 	zpool_enable_datasets()
62  * 	zpool_disable_datasets()
63  */
64 
65 #include <dirent.h>
66 #include <dlfcn.h>
67 #include <errno.h>
68 #include <fcntl.h>
69 #include <libgen.h>
70 #include <libintl.h>
71 #include <stdio.h>
72 #include <stdlib.h>
73 #include <strings.h>
74 #include <unistd.h>
75 #include <zone.h>
76 #include <sys/mntent.h>
77 #include <sys/mount.h>
78 #include <sys/stat.h>
79 
80 #include <libzfs.h>
81 
82 #include "libzfs_impl.h"
83 
84 #include <libshare.h>
85 #include <sys/systeminfo.h>
86 #define	MAXISALEN	257	/* based on sysinfo(2) man page */
87 
88 static int zfs_share_proto(zfs_handle_t *, zfs_share_proto_t *);
89 zfs_share_type_t zfs_is_shared_proto(zfs_handle_t *, char **,
90     zfs_share_proto_t);
91 
92 /*
93  * The share protocols table must be in the same order as the zfs_share_prot_t
94  * enum in libzfs_impl.h
95  */
96 typedef struct {
97 	zfs_prop_t p_prop;
98 	char *p_name;
99 	int p_share_err;
100 	int p_unshare_err;
101 } proto_table_t;
102 
103 proto_table_t proto_table[PROTO_END] = {
104 	{ZFS_PROP_SHARENFS, "nfs", EZFS_SHARENFSFAILED, EZFS_UNSHARENFSFAILED},
105 	{ZFS_PROP_SHARESMB, "smb", EZFS_SHARESMBFAILED, EZFS_UNSHARESMBFAILED},
106 };
107 
108 zfs_share_proto_t nfs_only[] = {
109 	PROTO_NFS,
110 	PROTO_END
111 };
112 
113 zfs_share_proto_t smb_only[] = {
114 	PROTO_SMB,
115 	PROTO_END
116 };
117 zfs_share_proto_t share_all_proto[] = {
118 	PROTO_NFS,
119 	PROTO_SMB,
120 	PROTO_END
121 };
122 
123 /*
124  * Search the sharetab for the given mountpoint and protocol, returning
125  * a zfs_share_type_t value.
126  */
127 static zfs_share_type_t
128 is_shared(libzfs_handle_t *hdl, const char *mountpoint, zfs_share_proto_t proto)
129 {
130 	char buf[MAXPATHLEN], *tab;
131 	char *ptr;
132 
133 	if (hdl->libzfs_sharetab == NULL)
134 		return (SHARED_NOT_SHARED);
135 
136 	(void) fseek(hdl->libzfs_sharetab, 0, SEEK_SET);
137 
138 	while (fgets(buf, sizeof (buf), hdl->libzfs_sharetab) != NULL) {
139 
140 		/* the mountpoint is the first entry on each line */
141 		if ((tab = strchr(buf, '\t')) == NULL)
142 			continue;
143 
144 		*tab = '\0';
145 		if (strcmp(buf, mountpoint) == 0) {
146 			/*
147 			 * the protocol field is the third field
148 			 * skip over second field
149 			 */
150 			ptr = ++tab;
151 			if ((tab = strchr(ptr, '\t')) == NULL)
152 				continue;
153 			ptr = ++tab;
154 			if ((tab = strchr(ptr, '\t')) == NULL)
155 				continue;
156 			*tab = '\0';
157 			if (strcmp(ptr,
158 			    proto_table[proto].p_name) == 0) {
159 				switch (proto) {
160 				case PROTO_NFS:
161 					return (SHARED_NFS);
162 				case PROTO_SMB:
163 					return (SHARED_SMB);
164 				default:
165 					return (0);
166 				}
167 			}
168 		}
169 	}
170 
171 	return (SHARED_NOT_SHARED);
172 }
173 
174 /*
175  * Returns true if the specified directory is empty.  If we can't open the
176  * directory at all, return true so that the mount can fail with a more
177  * informative error message.
178  */
179 static boolean_t
180 dir_is_empty(const char *dirname)
181 {
182 	DIR *dirp;
183 	struct dirent64 *dp;
184 	int dirfd;
185 
186 	if ((dirfd = openat(AT_FDCWD, dirname,
187 	    O_RDONLY | O_NDELAY | O_LARGEFILE | O_CLOEXEC, 0)) < 0) {
188 		return (B_TRUE);
189 	}
190 
191 	if ((dirp = fdopendir(dirfd)) == NULL) {
192 		return (B_TRUE);
193 	}
194 
195 	while ((dp = readdir64(dirp)) != NULL) {
196 
197 		if (strcmp(dp->d_name, ".") == 0 ||
198 		    strcmp(dp->d_name, "..") == 0)
199 			continue;
200 
201 		(void) closedir(dirp);
202 		return (B_FALSE);
203 	}
204 
205 	(void) closedir(dirp);
206 	return (B_TRUE);
207 }
208 
209 /*
210  * Checks to see if the mount is active.  If the filesystem is mounted, we fill
211  * in 'where' with the current mountpoint, and return 1.  Otherwise, we return
212  * 0.
213  */
214 boolean_t
215 is_mounted(libzfs_handle_t *zfs_hdl, const char *special, char **where)
216 {
217 	struct mnttab entry;
218 
219 	if (libzfs_mnttab_find(zfs_hdl, special, &entry) != 0)
220 		return (B_FALSE);
221 
222 	if (where != NULL)
223 		*where = zfs_strdup(zfs_hdl, entry.mnt_mountp);
224 
225 	return (B_TRUE);
226 }
227 
228 boolean_t
229 zfs_is_mounted(zfs_handle_t *zhp, char **where)
230 {
231 	return (is_mounted(zhp->zfs_hdl, zfs_get_name(zhp), where));
232 }
233 
234 /*
235  * Returns true if the given dataset is mountable, false otherwise.  Returns the
236  * mountpoint in 'buf'.
237  */
238 static boolean_t
239 zfs_is_mountable(zfs_handle_t *zhp, char *buf, size_t buflen,
240     zprop_source_t *source)
241 {
242 	char sourceloc[MAXNAMELEN];
243 	zprop_source_t sourcetype;
244 
245 	if (!zfs_prop_valid_for_type(ZFS_PROP_MOUNTPOINT, zhp->zfs_type))
246 		return (B_FALSE);
247 
248 	verify(zfs_prop_get(zhp, ZFS_PROP_MOUNTPOINT, buf, buflen,
249 	    &sourcetype, sourceloc, sizeof (sourceloc), B_FALSE) == 0);
250 
251 	if (strcmp(buf, ZFS_MOUNTPOINT_NONE) == 0 ||
252 	    strcmp(buf, ZFS_MOUNTPOINT_LEGACY) == 0)
253 		return (B_FALSE);
254 
255 	if (zfs_prop_get_int(zhp, ZFS_PROP_CANMOUNT) == ZFS_CANMOUNT_OFF)
256 		return (B_FALSE);
257 
258 	if (zfs_prop_get_int(zhp, ZFS_PROP_ZONED) &&
259 	    getzoneid() == GLOBAL_ZONEID)
260 		return (B_FALSE);
261 
262 	if (source)
263 		*source = sourcetype;
264 
265 	return (B_TRUE);
266 }
267 
268 /*
269  * Mount the given filesystem.
270  */
271 int
272 zfs_mount(zfs_handle_t *zhp, const char *options, int flags)
273 {
274 	struct stat buf;
275 	char mountpoint[ZFS_MAXPROPLEN];
276 	char mntopts[MNT_LINE_MAX];
277 	libzfs_handle_t *hdl = zhp->zfs_hdl;
278 
279 	if (options == NULL)
280 		mntopts[0] = '\0';
281 	else
282 		(void) strlcpy(mntopts, options, sizeof (mntopts));
283 
284 	/*
285 	 * If the pool is imported read-only then all mounts must be read-only
286 	 */
287 	if (zpool_get_prop_int(zhp->zpool_hdl, ZPOOL_PROP_READONLY, NULL))
288 		flags |= MS_RDONLY;
289 
290 	if (!zfs_is_mountable(zhp, mountpoint, sizeof (mountpoint), NULL))
291 		return (0);
292 
293 	/* Create the directory if it doesn't already exist */
294 	if (lstat(mountpoint, &buf) != 0) {
295 		if (mkdirp(mountpoint, 0755) != 0) {
296 			zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
297 			    "failed to create mountpoint"));
298 			return (zfs_error_fmt(hdl, EZFS_MOUNTFAILED,
299 			    dgettext(TEXT_DOMAIN, "cannot mount '%s'"),
300 			    mountpoint));
301 		}
302 	}
303 
304 	/*
305 	 * Determine if the mountpoint is empty.  If so, refuse to perform the
306 	 * mount.  We don't perform this check if MS_OVERLAY is specified, which
307 	 * would defeat the point.  We also avoid this check if 'remount' is
308 	 * specified.
309 	 */
310 	if ((flags & MS_OVERLAY) == 0 &&
311 	    strstr(mntopts, MNTOPT_REMOUNT) == NULL &&
312 	    !dir_is_empty(mountpoint)) {
313 		zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
314 		    "directory is not empty"));
315 		return (zfs_error_fmt(hdl, EZFS_MOUNTFAILED,
316 		    dgettext(TEXT_DOMAIN, "cannot mount '%s'"), mountpoint));
317 	}
318 
319 	/* perform the mount */
320 	if (mount(zfs_get_name(zhp), mountpoint, MS_OPTIONSTR | flags,
321 	    MNTTYPE_ZFS, NULL, 0, mntopts, sizeof (mntopts)) != 0) {
322 		/*
323 		 * Generic errors are nasty, but there are just way too many
324 		 * from mount(), and they're well-understood.  We pick a few
325 		 * common ones to improve upon.
326 		 */
327 		if (errno == EBUSY) {
328 			zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
329 			    "mountpoint or dataset is busy"));
330 		} else if (errno == EPERM) {
331 			zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
332 			    "Insufficient privileges"));
333 		} else if (errno == ENOTSUP) {
334 			char buf[256];
335 			int spa_version;
336 
337 			VERIFY(zfs_spa_version(zhp, &spa_version) == 0);
338 			(void) snprintf(buf, sizeof (buf),
339 			    dgettext(TEXT_DOMAIN, "Can't mount a version %lld "
340 			    "file system on a version %d pool. Pool must be"
341 			    " upgraded to mount this file system."),
342 			    (u_longlong_t)zfs_prop_get_int(zhp,
343 			    ZFS_PROP_VERSION), spa_version);
344 			zfs_error_aux(hdl, dgettext(TEXT_DOMAIN, buf));
345 		} else {
346 			zfs_error_aux(hdl, strerror(errno));
347 		}
348 		return (zfs_error_fmt(hdl, EZFS_MOUNTFAILED,
349 		    dgettext(TEXT_DOMAIN, "cannot mount '%s'"),
350 		    zhp->zfs_name));
351 	}
352 
353 	/* add the mounted entry into our cache */
354 	libzfs_mnttab_add(hdl, zfs_get_name(zhp), mountpoint,
355 	    mntopts);
356 	return (0);
357 }
358 
359 /*
360  * Unmount a single filesystem.
361  */
362 static int
363 unmount_one(libzfs_handle_t *hdl, const char *mountpoint, int flags)
364 {
365 	if (umount2(mountpoint, flags) != 0) {
366 		zfs_error_aux(hdl, strerror(errno));
367 		return (zfs_error_fmt(hdl, EZFS_UMOUNTFAILED,
368 		    dgettext(TEXT_DOMAIN, "cannot unmount '%s'"),
369 		    mountpoint));
370 	}
371 
372 	return (0);
373 }
374 
375 /*
376  * Unmount the given filesystem.
377  */
378 int
379 zfs_unmount(zfs_handle_t *zhp, const char *mountpoint, int flags)
380 {
381 	libzfs_handle_t *hdl = zhp->zfs_hdl;
382 	struct mnttab entry;
383 	char *mntpt = NULL;
384 
385 	/* check to see if we need to unmount the filesystem */
386 	if (mountpoint != NULL || ((zfs_get_type(zhp) == ZFS_TYPE_FILESYSTEM) &&
387 	    libzfs_mnttab_find(hdl, zhp->zfs_name, &entry) == 0)) {
388 		/*
389 		 * mountpoint may have come from a call to
390 		 * getmnt/getmntany if it isn't NULL. If it is NULL,
391 		 * we know it comes from libzfs_mnttab_find which can
392 		 * then get freed later. We strdup it to play it safe.
393 		 */
394 		if (mountpoint == NULL)
395 			mntpt = zfs_strdup(hdl, entry.mnt_mountp);
396 		else
397 			mntpt = zfs_strdup(hdl, mountpoint);
398 
399 		/*
400 		 * Unshare and unmount the filesystem
401 		 */
402 		if (zfs_unshare_proto(zhp, mntpt, share_all_proto) != 0)
403 			return (-1);
404 
405 		if (unmount_one(hdl, mntpt, flags) != 0) {
406 			free(mntpt);
407 			(void) zfs_shareall(zhp);
408 			return (-1);
409 		}
410 		libzfs_mnttab_remove(hdl, zhp->zfs_name);
411 		free(mntpt);
412 	}
413 
414 	return (0);
415 }
416 
417 /*
418  * Unmount this filesystem and any children inheriting the mountpoint property.
419  * To do this, just act like we're changing the mountpoint property, but don't
420  * remount the filesystems afterwards.
421  */
422 int
423 zfs_unmountall(zfs_handle_t *zhp, int flags)
424 {
425 	prop_changelist_t *clp;
426 	int ret;
427 
428 	clp = changelist_gather(zhp, ZFS_PROP_MOUNTPOINT, 0, flags);
429 	if (clp == NULL)
430 		return (-1);
431 
432 	ret = changelist_prefix(clp);
433 	changelist_free(clp);
434 
435 	return (ret);
436 }
437 
438 boolean_t
439 zfs_is_shared(zfs_handle_t *zhp)
440 {
441 	zfs_share_type_t rc = 0;
442 	zfs_share_proto_t *curr_proto;
443 
444 	if (ZFS_IS_VOLUME(zhp))
445 		return (B_FALSE);
446 
447 	for (curr_proto = share_all_proto; *curr_proto != PROTO_END;
448 	    curr_proto++)
449 		rc |= zfs_is_shared_proto(zhp, NULL, *curr_proto);
450 
451 	return (rc ? B_TRUE : B_FALSE);
452 }
453 
454 int
455 zfs_share(zfs_handle_t *zhp)
456 {
457 	assert(!ZFS_IS_VOLUME(zhp));
458 	return (zfs_share_proto(zhp, share_all_proto));
459 }
460 
461 int
462 zfs_unshare(zfs_handle_t *zhp)
463 {
464 	assert(!ZFS_IS_VOLUME(zhp));
465 	return (zfs_unshareall(zhp));
466 }
467 
468 /*
469  * Check to see if the filesystem is currently shared.
470  */
471 zfs_share_type_t
472 zfs_is_shared_proto(zfs_handle_t *zhp, char **where, zfs_share_proto_t proto)
473 {
474 	char *mountpoint;
475 	zfs_share_type_t rc;
476 
477 	if (!zfs_is_mounted(zhp, &mountpoint))
478 		return (SHARED_NOT_SHARED);
479 
480 	if ((rc = is_shared(zhp->zfs_hdl, mountpoint, proto))
481 	    != SHARED_NOT_SHARED) {
482 		if (where != NULL)
483 			*where = mountpoint;
484 		else
485 			free(mountpoint);
486 		return (rc);
487 	} else {
488 		free(mountpoint);
489 		return (SHARED_NOT_SHARED);
490 	}
491 }
492 
493 boolean_t
494 zfs_is_shared_nfs(zfs_handle_t *zhp, char **where)
495 {
496 	return (zfs_is_shared_proto(zhp, where,
497 	    PROTO_NFS) != SHARED_NOT_SHARED);
498 }
499 
500 boolean_t
501 zfs_is_shared_smb(zfs_handle_t *zhp, char **where)
502 {
503 	return (zfs_is_shared_proto(zhp, where,
504 	    PROTO_SMB) != SHARED_NOT_SHARED);
505 }
506 
507 /*
508  * Make sure things will work if libshare isn't installed by using
509  * wrapper functions that check to see that the pointers to functions
510  * initialized in _zfs_init_libshare() are actually present.
511  */
512 
513 static sa_handle_t (*_sa_init)(int);
514 static void (*_sa_fini)(sa_handle_t);
515 static sa_share_t (*_sa_find_share)(sa_handle_t, char *);
516 static int (*_sa_enable_share)(sa_share_t, char *);
517 static int (*_sa_disable_share)(sa_share_t, char *);
518 static char *(*_sa_errorstr)(int);
519 static int (*_sa_parse_legacy_options)(sa_group_t, char *, char *);
520 static boolean_t (*_sa_needs_refresh)(sa_handle_t *);
521 static libzfs_handle_t *(*_sa_get_zfs_handle)(sa_handle_t);
522 static int (*_sa_zfs_process_share)(sa_handle_t, sa_group_t, sa_share_t,
523     char *, char *, zprop_source_t, char *, char *, char *);
524 static void (*_sa_update_sharetab_ts)(sa_handle_t);
525 
526 /*
527  * _zfs_init_libshare()
528  *
529  * Find the libshare.so.1 entry points that we use here and save the
530  * values to be used later. This is triggered by the runtime loader.
531  * Make sure the correct ISA version is loaded.
532  */
533 
534 #pragma init(_zfs_init_libshare)
535 static void
536 _zfs_init_libshare(void)
537 {
538 	void *libshare;
539 	char path[MAXPATHLEN];
540 	char isa[MAXISALEN];
541 
542 #if defined(_LP64)
543 	if (sysinfo(SI_ARCHITECTURE_64, isa, MAXISALEN) == -1)
544 		isa[0] = '\0';
545 #else
546 	isa[0] = '\0';
547 #endif
548 	(void) snprintf(path, MAXPATHLEN,
549 	    "/usr/lib/%s/libshare.so.1", isa);
550 
551 	if ((libshare = dlopen(path, RTLD_LAZY | RTLD_GLOBAL)) != NULL) {
552 		_sa_init = (sa_handle_t (*)(int))dlsym(libshare, "sa_init");
553 		_sa_fini = (void (*)(sa_handle_t))dlsym(libshare, "sa_fini");
554 		_sa_find_share = (sa_share_t (*)(sa_handle_t, char *))
555 		    dlsym(libshare, "sa_find_share");
556 		_sa_enable_share = (int (*)(sa_share_t, char *))dlsym(libshare,
557 		    "sa_enable_share");
558 		_sa_disable_share = (int (*)(sa_share_t, char *))dlsym(libshare,
559 		    "sa_disable_share");
560 		_sa_errorstr = (char *(*)(int))dlsym(libshare, "sa_errorstr");
561 		_sa_parse_legacy_options = (int (*)(sa_group_t, char *, char *))
562 		    dlsym(libshare, "sa_parse_legacy_options");
563 		_sa_needs_refresh = (boolean_t (*)(sa_handle_t *))
564 		    dlsym(libshare, "sa_needs_refresh");
565 		_sa_get_zfs_handle = (libzfs_handle_t *(*)(sa_handle_t))
566 		    dlsym(libshare, "sa_get_zfs_handle");
567 		_sa_zfs_process_share = (int (*)(sa_handle_t, sa_group_t,
568 		    sa_share_t, char *, char *, zprop_source_t, char *,
569 		    char *, char *))dlsym(libshare, "sa_zfs_process_share");
570 		_sa_update_sharetab_ts = (void (*)(sa_handle_t))
571 		    dlsym(libshare, "sa_update_sharetab_ts");
572 		if (_sa_init == NULL || _sa_fini == NULL ||
573 		    _sa_find_share == NULL || _sa_enable_share == NULL ||
574 		    _sa_disable_share == NULL || _sa_errorstr == NULL ||
575 		    _sa_parse_legacy_options == NULL ||
576 		    _sa_needs_refresh == NULL || _sa_get_zfs_handle == NULL ||
577 		    _sa_zfs_process_share == NULL ||
578 		    _sa_update_sharetab_ts == NULL) {
579 			_sa_init = NULL;
580 			_sa_fini = NULL;
581 			_sa_disable_share = NULL;
582 			_sa_enable_share = NULL;
583 			_sa_errorstr = NULL;
584 			_sa_parse_legacy_options = NULL;
585 			(void) dlclose(libshare);
586 			_sa_needs_refresh = NULL;
587 			_sa_get_zfs_handle = NULL;
588 			_sa_zfs_process_share = NULL;
589 			_sa_update_sharetab_ts = NULL;
590 		}
591 	}
592 }
593 
594 /*
595  * zfs_init_libshare(zhandle, service)
596  *
597  * Initialize the libshare API if it hasn't already been initialized.
598  * In all cases it returns 0 if it succeeded and an error if not. The
599  * service value is which part(s) of the API to initialize and is a
600  * direct map to the libshare sa_init(service) interface.
601  */
602 int
603 zfs_init_libshare(libzfs_handle_t *zhandle, int service)
604 {
605 	int ret = SA_OK;
606 
607 	if (_sa_init == NULL)
608 		ret = SA_CONFIG_ERR;
609 
610 	if (ret == SA_OK && zhandle->libzfs_shareflags & ZFSSHARE_MISS) {
611 		/*
612 		 * We had a cache miss. Most likely it is a new ZFS
613 		 * dataset that was just created. We want to make sure
614 		 * so check timestamps to see if a different process
615 		 * has updated any of the configuration. If there was
616 		 * some non-ZFS change, we need to re-initialize the
617 		 * internal cache.
618 		 */
619 		zhandle->libzfs_shareflags &= ~ZFSSHARE_MISS;
620 		if (_sa_needs_refresh != NULL &&
621 		    _sa_needs_refresh(zhandle->libzfs_sharehdl)) {
622 			zfs_uninit_libshare(zhandle);
623 			zhandle->libzfs_sharehdl = _sa_init(service);
624 		}
625 	}
626 
627 	if (ret == SA_OK && zhandle && zhandle->libzfs_sharehdl == NULL)
628 		zhandle->libzfs_sharehdl = _sa_init(service);
629 
630 	if (ret == SA_OK && zhandle->libzfs_sharehdl == NULL)
631 		ret = SA_NO_MEMORY;
632 
633 	return (ret);
634 }
635 
636 /*
637  * zfs_uninit_libshare(zhandle)
638  *
639  * Uninitialize the libshare API if it hasn't already been
640  * uninitialized. It is OK to call multiple times.
641  */
642 void
643 zfs_uninit_libshare(libzfs_handle_t *zhandle)
644 {
645 	if (zhandle != NULL && zhandle->libzfs_sharehdl != NULL) {
646 		if (_sa_fini != NULL)
647 			_sa_fini(zhandle->libzfs_sharehdl);
648 		zhandle->libzfs_sharehdl = NULL;
649 	}
650 }
651 
652 /*
653  * zfs_parse_options(options, proto)
654  *
655  * Call the legacy parse interface to get the protocol specific
656  * options using the NULL arg to indicate that this is a "parse" only.
657  */
658 int
659 zfs_parse_options(char *options, zfs_share_proto_t proto)
660 {
661 	if (_sa_parse_legacy_options != NULL) {
662 		return (_sa_parse_legacy_options(NULL, options,
663 		    proto_table[proto].p_name));
664 	}
665 	return (SA_CONFIG_ERR);
666 }
667 
668 /*
669  * zfs_sa_find_share(handle, path)
670  *
671  * wrapper around sa_find_share to find a share path in the
672  * configuration.
673  */
674 static sa_share_t
675 zfs_sa_find_share(sa_handle_t handle, char *path)
676 {
677 	if (_sa_find_share != NULL)
678 		return (_sa_find_share(handle, path));
679 	return (NULL);
680 }
681 
682 /*
683  * zfs_sa_enable_share(share, proto)
684  *
685  * Wrapper for sa_enable_share which enables a share for a specified
686  * protocol.
687  */
688 static int
689 zfs_sa_enable_share(sa_share_t share, char *proto)
690 {
691 	if (_sa_enable_share != NULL)
692 		return (_sa_enable_share(share, proto));
693 	return (SA_CONFIG_ERR);
694 }
695 
696 /*
697  * zfs_sa_disable_share(share, proto)
698  *
699  * Wrapper for sa_enable_share which disables a share for a specified
700  * protocol.
701  */
702 static int
703 zfs_sa_disable_share(sa_share_t share, char *proto)
704 {
705 	if (_sa_disable_share != NULL)
706 		return (_sa_disable_share(share, proto));
707 	return (SA_CONFIG_ERR);
708 }
709 
710 /*
711  * Share the given filesystem according to the options in the specified
712  * protocol specific properties (sharenfs, sharesmb).  We rely
713  * on "libshare" to the dirty work for us.
714  */
715 static int
716 zfs_share_proto(zfs_handle_t *zhp, zfs_share_proto_t *proto)
717 {
718 	char mountpoint[ZFS_MAXPROPLEN];
719 	char shareopts[ZFS_MAXPROPLEN];
720 	char sourcestr[ZFS_MAXPROPLEN];
721 	libzfs_handle_t *hdl = zhp->zfs_hdl;
722 	sa_share_t share;
723 	zfs_share_proto_t *curr_proto;
724 	zprop_source_t sourcetype;
725 	int ret;
726 
727 	if (!zfs_is_mountable(zhp, mountpoint, sizeof (mountpoint), NULL))
728 		return (0);
729 
730 	for (curr_proto = proto; *curr_proto != PROTO_END; curr_proto++) {
731 		/*
732 		 * Return success if there are no share options.
733 		 */
734 		if (zfs_prop_get(zhp, proto_table[*curr_proto].p_prop,
735 		    shareopts, sizeof (shareopts), &sourcetype, sourcestr,
736 		    ZFS_MAXPROPLEN, B_FALSE) != 0 ||
737 		    strcmp(shareopts, "off") == 0)
738 			continue;
739 
740 		ret = zfs_init_libshare(hdl, SA_INIT_SHARE_API);
741 		if (ret != SA_OK) {
742 			(void) zfs_error_fmt(hdl, EZFS_SHARENFSFAILED,
743 			    dgettext(TEXT_DOMAIN, "cannot share '%s': %s"),
744 			    zfs_get_name(zhp), _sa_errorstr != NULL ?
745 			    _sa_errorstr(ret) : "");
746 			return (-1);
747 		}
748 
749 		/*
750 		 * If the 'zoned' property is set, then zfs_is_mountable()
751 		 * will have already bailed out if we are in the global zone.
752 		 * But local zones cannot be NFS servers, so we ignore it for
753 		 * local zones as well.
754 		 */
755 		if (zfs_prop_get_int(zhp, ZFS_PROP_ZONED))
756 			continue;
757 
758 		share = zfs_sa_find_share(hdl->libzfs_sharehdl, mountpoint);
759 		if (share == NULL) {
760 			/*
761 			 * This may be a new file system that was just
762 			 * created so isn't in the internal cache
763 			 * (second time through). Rather than
764 			 * reloading the entire configuration, we can
765 			 * assume ZFS has done the checking and it is
766 			 * safe to add this to the internal
767 			 * configuration.
768 			 */
769 			if (_sa_zfs_process_share(hdl->libzfs_sharehdl,
770 			    NULL, NULL, mountpoint,
771 			    proto_table[*curr_proto].p_name, sourcetype,
772 			    shareopts, sourcestr, zhp->zfs_name) != SA_OK) {
773 				(void) zfs_error_fmt(hdl,
774 				    proto_table[*curr_proto].p_share_err,
775 				    dgettext(TEXT_DOMAIN, "cannot share '%s'"),
776 				    zfs_get_name(zhp));
777 				return (-1);
778 			}
779 			hdl->libzfs_shareflags |= ZFSSHARE_MISS;
780 			share = zfs_sa_find_share(hdl->libzfs_sharehdl,
781 			    mountpoint);
782 		}
783 		if (share != NULL) {
784 			int err;
785 			err = zfs_sa_enable_share(share,
786 			    proto_table[*curr_proto].p_name);
787 			if (err != SA_OK) {
788 				(void) zfs_error_fmt(hdl,
789 				    proto_table[*curr_proto].p_share_err,
790 				    dgettext(TEXT_DOMAIN, "cannot share '%s'"),
791 				    zfs_get_name(zhp));
792 				return (-1);
793 			}
794 		} else {
795 			(void) zfs_error_fmt(hdl,
796 			    proto_table[*curr_proto].p_share_err,
797 			    dgettext(TEXT_DOMAIN, "cannot share '%s'"),
798 			    zfs_get_name(zhp));
799 			return (-1);
800 		}
801 
802 	}
803 	return (0);
804 }
805 
806 
807 int
808 zfs_share_nfs(zfs_handle_t *zhp)
809 {
810 	return (zfs_share_proto(zhp, nfs_only));
811 }
812 
813 int
814 zfs_share_smb(zfs_handle_t *zhp)
815 {
816 	return (zfs_share_proto(zhp, smb_only));
817 }
818 
819 int
820 zfs_shareall(zfs_handle_t *zhp)
821 {
822 	return (zfs_share_proto(zhp, share_all_proto));
823 }
824 
825 /*
826  * Unshare a filesystem by mountpoint.
827  */
828 static int
829 unshare_one(libzfs_handle_t *hdl, const char *name, const char *mountpoint,
830     zfs_share_proto_t proto)
831 {
832 	sa_share_t share;
833 	int err;
834 	char *mntpt;
835 	/*
836 	 * Mountpoint could get trashed if libshare calls getmntany
837 	 * which it does during API initialization, so strdup the
838 	 * value.
839 	 */
840 	mntpt = zfs_strdup(hdl, mountpoint);
841 
842 	/* make sure libshare initialized */
843 	if ((err = zfs_init_libshare(hdl, SA_INIT_SHARE_API)) != SA_OK) {
844 		free(mntpt);	/* don't need the copy anymore */
845 		return (zfs_error_fmt(hdl, EZFS_UNSHARENFSFAILED,
846 		    dgettext(TEXT_DOMAIN, "cannot unshare '%s': %s"),
847 		    name, _sa_errorstr(err)));
848 	}
849 
850 	share = zfs_sa_find_share(hdl->libzfs_sharehdl, mntpt);
851 	free(mntpt);	/* don't need the copy anymore */
852 
853 	if (share != NULL) {
854 		err = zfs_sa_disable_share(share, proto_table[proto].p_name);
855 		if (err != SA_OK) {
856 			return (zfs_error_fmt(hdl, EZFS_UNSHARENFSFAILED,
857 			    dgettext(TEXT_DOMAIN, "cannot unshare '%s': %s"),
858 			    name, _sa_errorstr(err)));
859 		}
860 	} else {
861 		return (zfs_error_fmt(hdl, EZFS_UNSHARENFSFAILED,
862 		    dgettext(TEXT_DOMAIN, "cannot unshare '%s': not found"),
863 		    name));
864 	}
865 	return (0);
866 }
867 
868 /*
869  * Unshare the given filesystem.
870  */
871 int
872 zfs_unshare_proto(zfs_handle_t *zhp, const char *mountpoint,
873     zfs_share_proto_t *proto)
874 {
875 	libzfs_handle_t *hdl = zhp->zfs_hdl;
876 	struct mnttab entry;
877 	char *mntpt = NULL;
878 
879 	/* check to see if need to unmount the filesystem */
880 	rewind(zhp->zfs_hdl->libzfs_mnttab);
881 	if (mountpoint != NULL)
882 		mountpoint = mntpt = zfs_strdup(hdl, mountpoint);
883 
884 	if (mountpoint != NULL || ((zfs_get_type(zhp) == ZFS_TYPE_FILESYSTEM) &&
885 	    libzfs_mnttab_find(hdl, zfs_get_name(zhp), &entry) == 0)) {
886 		zfs_share_proto_t *curr_proto;
887 
888 		if (mountpoint == NULL)
889 			mntpt = zfs_strdup(zhp->zfs_hdl, entry.mnt_mountp);
890 
891 		for (curr_proto = proto; *curr_proto != PROTO_END;
892 		    curr_proto++) {
893 
894 			if (is_shared(hdl, mntpt, *curr_proto) &&
895 			    unshare_one(hdl, zhp->zfs_name,
896 			    mntpt, *curr_proto) != 0) {
897 				if (mntpt != NULL)
898 					free(mntpt);
899 				return (-1);
900 			}
901 		}
902 	}
903 	if (mntpt != NULL)
904 		free(mntpt);
905 
906 	return (0);
907 }
908 
909 int
910 zfs_unshare_nfs(zfs_handle_t *zhp, const char *mountpoint)
911 {
912 	return (zfs_unshare_proto(zhp, mountpoint, nfs_only));
913 }
914 
915 int
916 zfs_unshare_smb(zfs_handle_t *zhp, const char *mountpoint)
917 {
918 	return (zfs_unshare_proto(zhp, mountpoint, smb_only));
919 }
920 
921 /*
922  * Same as zfs_unmountall(), but for NFS and SMB unshares.
923  */
924 int
925 zfs_unshareall_proto(zfs_handle_t *zhp, zfs_share_proto_t *proto)
926 {
927 	prop_changelist_t *clp;
928 	int ret;
929 
930 	clp = changelist_gather(zhp, ZFS_PROP_SHARENFS, 0, 0);
931 	if (clp == NULL)
932 		return (-1);
933 
934 	ret = changelist_unshare(clp, proto);
935 	changelist_free(clp);
936 
937 	return (ret);
938 }
939 
940 int
941 zfs_unshareall_nfs(zfs_handle_t *zhp)
942 {
943 	return (zfs_unshareall_proto(zhp, nfs_only));
944 }
945 
946 int
947 zfs_unshareall_smb(zfs_handle_t *zhp)
948 {
949 	return (zfs_unshareall_proto(zhp, smb_only));
950 }
951 
952 int
953 zfs_unshareall(zfs_handle_t *zhp)
954 {
955 	return (zfs_unshareall_proto(zhp, share_all_proto));
956 }
957 
958 int
959 zfs_unshareall_bypath(zfs_handle_t *zhp, const char *mountpoint)
960 {
961 	return (zfs_unshare_proto(zhp, mountpoint, share_all_proto));
962 }
963 
964 /*
965  * Remove the mountpoint associated with the current dataset, if necessary.
966  * We only remove the underlying directory if:
967  *
968  *	- The mountpoint is not 'none' or 'legacy'
969  *	- The mountpoint is non-empty
970  *	- The mountpoint is the default or inherited
971  *	- The 'zoned' property is set, or we're in a local zone
972  *
973  * Any other directories we leave alone.
974  */
975 void
976 remove_mountpoint(zfs_handle_t *zhp)
977 {
978 	char mountpoint[ZFS_MAXPROPLEN];
979 	zprop_source_t source;
980 
981 	if (!zfs_is_mountable(zhp, mountpoint, sizeof (mountpoint),
982 	    &source))
983 		return;
984 
985 	if (source == ZPROP_SRC_DEFAULT ||
986 	    source == ZPROP_SRC_INHERITED) {
987 		/*
988 		 * Try to remove the directory, silently ignoring any errors.
989 		 * The filesystem may have since been removed or moved around,
990 		 * and this error isn't really useful to the administrator in
991 		 * any way.
992 		 */
993 		(void) rmdir(mountpoint);
994 	}
995 }
996 
997 void
998 libzfs_add_handle(get_all_cb_t *cbp, zfs_handle_t *zhp)
999 {
1000 	if (cbp->cb_alloc == cbp->cb_used) {
1001 		size_t newsz;
1002 		void *ptr;
1003 
1004 		newsz = cbp->cb_alloc ? cbp->cb_alloc * 2 : 64;
1005 		ptr = zfs_realloc(zhp->zfs_hdl,
1006 		    cbp->cb_handles, cbp->cb_alloc * sizeof (void *),
1007 		    newsz * sizeof (void *));
1008 		cbp->cb_handles = ptr;
1009 		cbp->cb_alloc = newsz;
1010 	}
1011 	cbp->cb_handles[cbp->cb_used++] = zhp;
1012 }
1013 
1014 static int
1015 mount_cb(zfs_handle_t *zhp, void *data)
1016 {
1017 	get_all_cb_t *cbp = data;
1018 
1019 	if (!(zfs_get_type(zhp) & ZFS_TYPE_FILESYSTEM)) {
1020 		zfs_close(zhp);
1021 		return (0);
1022 	}
1023 
1024 	if (zfs_prop_get_int(zhp, ZFS_PROP_CANMOUNT) == ZFS_CANMOUNT_NOAUTO) {
1025 		zfs_close(zhp);
1026 		return (0);
1027 	}
1028 
1029 	/*
1030 	 * If this filesystem is inconsistent and has a receive resume
1031 	 * token, we can not mount it.
1032 	 */
1033 	if (zfs_prop_get_int(zhp, ZFS_PROP_INCONSISTENT) &&
1034 	    zfs_prop_get(zhp, ZFS_PROP_RECEIVE_RESUME_TOKEN,
1035 	    NULL, 0, NULL, NULL, 0, B_TRUE) == 0) {
1036 		zfs_close(zhp);
1037 		return (0);
1038 	}
1039 
1040 	libzfs_add_handle(cbp, zhp);
1041 	if (zfs_iter_filesystems(zhp, mount_cb, cbp) != 0) {
1042 		zfs_close(zhp);
1043 		return (-1);
1044 	}
1045 	return (0);
1046 }
1047 
1048 int
1049 libzfs_dataset_cmp(const void *a, const void *b)
1050 {
1051 	zfs_handle_t **za = (zfs_handle_t **)a;
1052 	zfs_handle_t **zb = (zfs_handle_t **)b;
1053 	char mounta[MAXPATHLEN];
1054 	char mountb[MAXPATHLEN];
1055 	boolean_t gota, gotb;
1056 
1057 	if ((gota = (zfs_get_type(*za) == ZFS_TYPE_FILESYSTEM)) != 0)
1058 		verify(zfs_prop_get(*za, ZFS_PROP_MOUNTPOINT, mounta,
1059 		    sizeof (mounta), NULL, NULL, 0, B_FALSE) == 0);
1060 	if ((gotb = (zfs_get_type(*zb) == ZFS_TYPE_FILESYSTEM)) != 0)
1061 		verify(zfs_prop_get(*zb, ZFS_PROP_MOUNTPOINT, mountb,
1062 		    sizeof (mountb), NULL, NULL, 0, B_FALSE) == 0);
1063 
1064 	if (gota && gotb)
1065 		return (strcmp(mounta, mountb));
1066 
1067 	if (gota)
1068 		return (-1);
1069 	if (gotb)
1070 		return (1);
1071 
1072 	return (strcmp(zfs_get_name(a), zfs_get_name(b)));
1073 }
1074 
1075 /*
1076  * Mount and share all datasets within the given pool.  This assumes that no
1077  * datasets within the pool are currently mounted.  Because users can create
1078  * complicated nested hierarchies of mountpoints, we first gather all the
1079  * datasets and mountpoints within the pool, and sort them by mountpoint.  Once
1080  * we have the list of all filesystems, we iterate over them in order and mount
1081  * and/or share each one.
1082  */
1083 #pragma weak zpool_mount_datasets = zpool_enable_datasets
1084 int
1085 zpool_enable_datasets(zpool_handle_t *zhp, const char *mntopts, int flags)
1086 {
1087 	get_all_cb_t cb = { 0 };
1088 	libzfs_handle_t *hdl = zhp->zpool_hdl;
1089 	zfs_handle_t *zfsp;
1090 	int i, ret = -1;
1091 	int *good;
1092 
1093 	/*
1094 	 * Gather all non-snap datasets within the pool.
1095 	 */
1096 	if ((zfsp = zfs_open(hdl, zhp->zpool_name, ZFS_TYPE_DATASET)) == NULL)
1097 		goto out;
1098 
1099 	libzfs_add_handle(&cb, zfsp);
1100 	if (zfs_iter_filesystems(zfsp, mount_cb, &cb) != 0)
1101 		goto out;
1102 	/*
1103 	 * Sort the datasets by mountpoint.
1104 	 */
1105 	qsort(cb.cb_handles, cb.cb_used, sizeof (void *),
1106 	    libzfs_dataset_cmp);
1107 
1108 	/*
1109 	 * And mount all the datasets, keeping track of which ones
1110 	 * succeeded or failed.
1111 	 */
1112 	if ((good = zfs_alloc(zhp->zpool_hdl,
1113 	    cb.cb_used * sizeof (int))) == NULL)
1114 		goto out;
1115 
1116 	ret = 0;
1117 	for (i = 0; i < cb.cb_used; i++) {
1118 		if (zfs_mount(cb.cb_handles[i], mntopts, flags) != 0)
1119 			ret = -1;
1120 		else
1121 			good[i] = 1;
1122 	}
1123 
1124 	/*
1125 	 * Then share all the ones that need to be shared. This needs
1126 	 * to be a separate pass in order to avoid excessive reloading
1127 	 * of the configuration. Good should never be NULL since
1128 	 * zfs_alloc is supposed to exit if memory isn't available.
1129 	 */
1130 	for (i = 0; i < cb.cb_used; i++) {
1131 		if (good[i] && zfs_share(cb.cb_handles[i]) != 0)
1132 			ret = -1;
1133 	}
1134 
1135 	free(good);
1136 
1137 out:
1138 	for (i = 0; i < cb.cb_used; i++)
1139 		zfs_close(cb.cb_handles[i]);
1140 	free(cb.cb_handles);
1141 
1142 	return (ret);
1143 }
1144 
1145 static int
1146 mountpoint_compare(const void *a, const void *b)
1147 {
1148 	const char *mounta = *((char **)a);
1149 	const char *mountb = *((char **)b);
1150 
1151 	return (strcmp(mountb, mounta));
1152 }
1153 
1154 /* alias for 2002/240 */
1155 #pragma weak zpool_unmount_datasets = zpool_disable_datasets
1156 /*
1157  * Unshare and unmount all datasets within the given pool.  We don't want to
1158  * rely on traversing the DSL to discover the filesystems within the pool,
1159  * because this may be expensive (if not all of them are mounted), and can fail
1160  * arbitrarily (on I/O error, for example).  Instead, we walk /etc/mnttab and
1161  * gather all the filesystems that are currently mounted.
1162  */
1163 int
1164 zpool_disable_datasets(zpool_handle_t *zhp, boolean_t force)
1165 {
1166 	int used, alloc;
1167 	struct mnttab entry;
1168 	size_t namelen;
1169 	char **mountpoints = NULL;
1170 	zfs_handle_t **datasets = NULL;
1171 	libzfs_handle_t *hdl = zhp->zpool_hdl;
1172 	int i;
1173 	int ret = -1;
1174 	int flags = (force ? MS_FORCE : 0);
1175 
1176 	namelen = strlen(zhp->zpool_name);
1177 
1178 	rewind(hdl->libzfs_mnttab);
1179 	used = alloc = 0;
1180 	while (getmntent(hdl->libzfs_mnttab, &entry) == 0) {
1181 		/*
1182 		 * Ignore non-ZFS entries.
1183 		 */
1184 		if (entry.mnt_fstype == NULL ||
1185 		    strcmp(entry.mnt_fstype, MNTTYPE_ZFS) != 0)
1186 			continue;
1187 
1188 		/*
1189 		 * Ignore filesystems not within this pool.
1190 		 */
1191 		if (entry.mnt_mountp == NULL ||
1192 		    strncmp(entry.mnt_special, zhp->zpool_name, namelen) != 0 ||
1193 		    (entry.mnt_special[namelen] != '/' &&
1194 		    entry.mnt_special[namelen] != '\0'))
1195 			continue;
1196 
1197 		/*
1198 		 * At this point we've found a filesystem within our pool.  Add
1199 		 * it to our growing list.
1200 		 */
1201 		if (used == alloc) {
1202 			if (alloc == 0) {
1203 				if ((mountpoints = zfs_alloc(hdl,
1204 				    8 * sizeof (void *))) == NULL)
1205 					goto out;
1206 
1207 				if ((datasets = zfs_alloc(hdl,
1208 				    8 * sizeof (void *))) == NULL)
1209 					goto out;
1210 
1211 				alloc = 8;
1212 			} else {
1213 				void *ptr;
1214 
1215 				if ((ptr = zfs_realloc(hdl, mountpoints,
1216 				    alloc * sizeof (void *),
1217 				    alloc * 2 * sizeof (void *))) == NULL)
1218 					goto out;
1219 				mountpoints = ptr;
1220 
1221 				if ((ptr = zfs_realloc(hdl, datasets,
1222 				    alloc * sizeof (void *),
1223 				    alloc * 2 * sizeof (void *))) == NULL)
1224 					goto out;
1225 				datasets = ptr;
1226 
1227 				alloc *= 2;
1228 			}
1229 		}
1230 
1231 		if ((mountpoints[used] = zfs_strdup(hdl,
1232 		    entry.mnt_mountp)) == NULL)
1233 			goto out;
1234 
1235 		/*
1236 		 * This is allowed to fail, in case there is some I/O error.  It
1237 		 * is only used to determine if we need to remove the underlying
1238 		 * mountpoint, so failure is not fatal.
1239 		 */
1240 		datasets[used] = make_dataset_handle(hdl, entry.mnt_special);
1241 
1242 		used++;
1243 	}
1244 
1245 	/*
1246 	 * At this point, we have the entire list of filesystems, so sort it by
1247 	 * mountpoint.
1248 	 */
1249 	qsort(mountpoints, used, sizeof (char *), mountpoint_compare);
1250 
1251 	/*
1252 	 * Walk through and first unshare everything.
1253 	 */
1254 	for (i = 0; i < used; i++) {
1255 		zfs_share_proto_t *curr_proto;
1256 		for (curr_proto = share_all_proto; *curr_proto != PROTO_END;
1257 		    curr_proto++) {
1258 			if (is_shared(hdl, mountpoints[i], *curr_proto) &&
1259 			    unshare_one(hdl, mountpoints[i],
1260 			    mountpoints[i], *curr_proto) != 0)
1261 				goto out;
1262 		}
1263 	}
1264 
1265 	/*
1266 	 * Now unmount everything, removing the underlying directories as
1267 	 * appropriate.
1268 	 */
1269 	for (i = 0; i < used; i++) {
1270 		if (unmount_one(hdl, mountpoints[i], flags) != 0)
1271 			goto out;
1272 	}
1273 
1274 	for (i = 0; i < used; i++) {
1275 		if (datasets[i])
1276 			remove_mountpoint(datasets[i]);
1277 	}
1278 
1279 	ret = 0;
1280 out:
1281 	for (i = 0; i < used; i++) {
1282 		if (datasets[i])
1283 			zfs_close(datasets[i]);
1284 		free(mountpoints[i]);
1285 	}
1286 	free(datasets);
1287 	free(mountpoints);
1288 
1289 	return (ret);
1290 }
1291