xref: /titanic_50/usr/src/lib/libshare/common/libshare_zfs.c (revision 582271e8d649568c83e9a016cc0d54265389c5d9)
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 2007 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 #include <stdio.h>
30 #include <libzfs.h>
31 #include <string.h>
32 #include <strings.h>
33 #include <libshare.h>
34 #include "libshare_impl.h"
35 #include <libintl.h>
36 #include <sys/mnttab.h>
37 #include <sys/mntent.h>
38 
39 extern sa_share_t _sa_add_share(sa_group_t, char *, int, int *, uint64_t);
40 extern sa_group_t _sa_create_zfs_group(sa_group_t, char *);
41 extern char *sa_fstype(char *);
42 extern void set_node_attr(void *, char *, char *);
43 extern int sa_is_share(void *);
44 
45 /*
46  * File system specific code for ZFS. The original code was stolen
47  * from the "zfs" command and modified to better suit this library's
48  * usage.
49  */
50 
51 typedef struct get_all_cbdata {
52 	zfs_handle_t	**cb_handles;
53 	size_t		cb_alloc;
54 	size_t		cb_used;
55 	uint_t		cb_types;
56 } get_all_cbdata_t;
57 
58 /*
59  * sa_zfs_init(impl_handle)
60  *
61  * Initialize an access handle into libzfs.  The handle needs to stay
62  * around until sa_zfs_fini() in order to maintain the cache of
63  * mounts.
64  */
65 
66 int
67 sa_zfs_init(sa_handle_impl_t impl_handle)
68 {
69 	impl_handle->zfs_libhandle = libzfs_init();
70 	if (impl_handle->zfs_libhandle != NULL) {
71 		libzfs_print_on_error(impl_handle->zfs_libhandle, B_TRUE);
72 		return (B_TRUE);
73 	}
74 	return (B_FALSE);
75 }
76 
77 /*
78  * sa_zfs_fini(impl_handle)
79  *
80  * cleanup data structures and the libzfs handle used for accessing
81  * zfs file share info.
82  */
83 
84 void
85 sa_zfs_fini(sa_handle_impl_t impl_handle)
86 {
87 	if (impl_handle->zfs_libhandle != NULL) {
88 		if (impl_handle->zfs_list != NULL) {
89 			zfs_handle_t **zhp = impl_handle->zfs_list;
90 			size_t i;
91 
92 			/*
93 			 * Contents of zfs_list need to be freed so we
94 			 * don't lose ZFS handles.
95 			 */
96 			for (i = 0; i < impl_handle->zfs_list_count; i++) {
97 				zfs_close(zhp[i]);
98 			}
99 			free(impl_handle->zfs_list);
100 			impl_handle->zfs_list = NULL;
101 			impl_handle->zfs_list_count = 0;
102 		}
103 
104 		libzfs_fini(impl_handle->zfs_libhandle);
105 		impl_handle->zfs_libhandle = NULL;
106 	}
107 }
108 
109 /*
110  * get_one_filesystem(zfs_handle_t, data)
111  *
112  * an iterator function called while iterating through the ZFS
113  * root. It accumulates into an array of file system handles that can
114  * be used to derive info about those file systems.
115  *
116  * Note that as this function is called, we close all zhp handles that
117  * are not going to be places into the cp_handles list. We don't want
118  * to close the ones we are keeping, but all others would be leaked if
119  * not closed here.
120  */
121 
122 static int
123 get_one_filesystem(zfs_handle_t *zhp, void *data)
124 {
125 	get_all_cbdata_t *cbp = data;
126 	zfs_type_t type = zfs_get_type(zhp);
127 
128 	/*
129 	 * Interate over any nested datasets.
130 	 */
131 	if (type == ZFS_TYPE_FILESYSTEM &&
132 	    zfs_iter_filesystems(zhp, get_one_filesystem, data) != 0) {
133 		zfs_close(zhp);
134 		return (1);
135 	}
136 
137 	/*
138 	 * Skip any datasets whose type does not match.
139 	 */
140 	if ((type & cbp->cb_types) == 0) {
141 		zfs_close(zhp);
142 		return (0);
143 	}
144 
145 	if (cbp->cb_alloc == cbp->cb_used) {
146 		zfs_handle_t **handles;
147 
148 		if (cbp->cb_alloc == 0)
149 			cbp->cb_alloc = 64;
150 		else
151 			cbp->cb_alloc *= 2;
152 
153 		handles = (zfs_handle_t **)calloc(1,
154 		    cbp->cb_alloc * sizeof (void *));
155 
156 		if (handles == NULL) {
157 			zfs_close(zhp);
158 			return (0);
159 		}
160 		if (cbp->cb_handles) {
161 			bcopy(cbp->cb_handles, handles,
162 			    cbp->cb_used * sizeof (void *));
163 			free(cbp->cb_handles);
164 		}
165 
166 		cbp->cb_handles = handles;
167 	}
168 
169 	cbp->cb_handles[cbp->cb_used++] = zhp;
170 
171 	return (0);
172 }
173 
174 /*
175  * get_all_filesystems(zfs_handle_t ***fslist, size_t *count)
176  *
177  * iterate through all ZFS file systems starting at the root. Returns
178  * a count and an array of handle pointers. Allocating is only done
179  * once. The caller does not need to free since it will be done at
180  * sa_zfs_fini() time.
181  */
182 
183 static void
184 get_all_filesystems(sa_handle_impl_t impl_handle,
185 			zfs_handle_t ***fslist, size_t *count)
186 {
187 	get_all_cbdata_t cb = { 0 };
188 	cb.cb_types = ZFS_TYPE_FILESYSTEM;
189 
190 	if (impl_handle->zfs_list != NULL) {
191 		*fslist = impl_handle->zfs_list;
192 		*count = impl_handle->zfs_list_count;
193 		return;
194 	}
195 
196 	(void) zfs_iter_root(impl_handle->zfs_libhandle,
197 	    get_one_filesystem, &cb);
198 
199 	impl_handle->zfs_list = *fslist = cb.cb_handles;
200 	impl_handle->zfs_list_count = *count = cb.cb_used;
201 }
202 
203 /*
204  * mountpoint_compare(a, b)
205  *
206  * compares the mountpoint on two zfs file systems handles.
207  * returns values following strcmp() model.
208  */
209 
210 static int
211 mountpoint_compare(const void *a, const void *b)
212 {
213 	zfs_handle_t **za = (zfs_handle_t **)a;
214 	zfs_handle_t **zb = (zfs_handle_t **)b;
215 	char mounta[MAXPATHLEN];
216 	char mountb[MAXPATHLEN];
217 
218 	verify(zfs_prop_get(*za, ZFS_PROP_MOUNTPOINT, mounta,
219 	    sizeof (mounta), NULL, NULL, 0, B_FALSE) == 0);
220 	verify(zfs_prop_get(*zb, ZFS_PROP_MOUNTPOINT, mountb,
221 	    sizeof (mountb), NULL, NULL, 0, B_FALSE) == 0);
222 
223 	return (strcmp(mounta, mountb));
224 }
225 
226 /*
227  * return legacy mountpoint.  Caller provides space for mountpoint.
228  */
229 int
230 get_legacy_mountpoint(char *path, char *mountpoint, size_t len)
231 {
232 	FILE *fp;
233 	struct mnttab entry;
234 
235 	if ((fp = fopen(MNTTAB, "r")) == NULL) {
236 		return (1);
237 	}
238 
239 	while (getmntent(fp, &entry) == 0) {
240 
241 		if (entry.mnt_fstype == NULL ||
242 		    strcmp(entry.mnt_fstype, MNTTYPE_ZFS) != 0)
243 			continue;
244 
245 		if (strcmp(entry.mnt_mountp, path) == 0) {
246 			(void) strlcpy(mountpoint, entry.mnt_special, len);
247 			(void) fclose(fp);
248 			return (0);
249 		}
250 	}
251 	(void) fclose(fp);
252 	return (1);
253 }
254 
255 /*
256  * get_zfs_dataset(impl_handle, path)
257  *
258  * get the name of the ZFS dataset the path is equivalent to.  The
259  * dataset name is used for get/set of ZFS properties since libzfs
260  * requires a dataset to do a zfs_open().
261  */
262 
263 static char *
264 get_zfs_dataset(sa_handle_impl_t impl_handle, char *path,
265     boolean_t search_mnttab)
266 {
267 	size_t i, count = 0;
268 	char *dataset = NULL;
269 	zfs_handle_t **zlist;
270 	char mountpoint[ZFS_MAXPROPLEN];
271 	char canmount[ZFS_MAXPROPLEN];
272 
273 	get_all_filesystems(impl_handle, &zlist, &count);
274 	qsort(zlist, count, sizeof (void *), mountpoint_compare);
275 	for (i = 0; i < count; i++) {
276 		/* must have a mountpoint */
277 		if (zfs_prop_get(zlist[i], ZFS_PROP_MOUNTPOINT, mountpoint,
278 		    sizeof (mountpoint), NULL, NULL, 0, B_FALSE) != 0) {
279 			/* no mountpoint */
280 			continue;
281 		}
282 
283 		/* mountpoint must be a path */
284 		if (strcmp(mountpoint, ZFS_MOUNTPOINT_NONE) == 0 ||
285 		    strcmp(mountpoint, ZFS_MOUNTPOINT_LEGACY) == 0) {
286 			/*
287 			 * Search mmttab for mountpoint
288 			 */
289 
290 			if (search_mnttab == B_TRUE &&
291 			    get_legacy_mountpoint(path, mountpoint,
292 			    sizeof (mountpoint)) == 0) {
293 				dataset = mountpoint;
294 				break;
295 			}
296 			continue;
297 		}
298 
299 		/* canmount must be set */
300 		canmount[0] = '\0';
301 		if (zfs_prop_get(zlist[i], ZFS_PROP_CANMOUNT, canmount,
302 		    sizeof (canmount), NULL, NULL, 0, B_FALSE) != 0 ||
303 		    strcmp(canmount, "off") == 0)
304 			continue;
305 
306 		/*
307 		 * have a mountable handle but want to skip those marked none
308 		 * and legacy
309 		 */
310 		if (strcmp(mountpoint, path) == 0) {
311 			dataset = (char *)zfs_get_name(zlist[i]);
312 			break;
313 		}
314 
315 	}
316 
317 	if (dataset != NULL)
318 		dataset = strdup(dataset);
319 
320 	return (dataset);
321 }
322 
323 /*
324  * get_zfs_property(dataset, property)
325  *
326  * Get the file system property specified from the ZFS dataset.
327  */
328 
329 static char *
330 get_zfs_property(char *dataset, zfs_prop_t property)
331 {
332 	zfs_handle_t *handle = NULL;
333 	char shareopts[ZFS_MAXPROPLEN];
334 	libzfs_handle_t *libhandle;
335 
336 	libhandle = libzfs_init();
337 	if (libhandle != NULL) {
338 		handle = zfs_open(libhandle, dataset, ZFS_TYPE_FILESYSTEM);
339 		if (handle != NULL) {
340 			if (zfs_prop_get(handle, property, shareopts,
341 			    sizeof (shareopts), NULL, NULL, 0,
342 			    B_FALSE) == 0) {
343 				zfs_close(handle);
344 				libzfs_fini(libhandle);
345 				return (strdup(shareopts));
346 			}
347 			zfs_close(handle);
348 		}
349 		libzfs_fini(libhandle);
350 	}
351 	return (NULL);
352 }
353 
354 /*
355  * sa_zfs_is_shared(handle, path)
356  *
357  * Check to see if the ZFS path provided has the sharenfs option set
358  * or not.
359  */
360 
361 int
362 sa_zfs_is_shared(sa_handle_t sahandle, char *path)
363 {
364 	int ret = 0;
365 	char *dataset;
366 	zfs_handle_t *handle = NULL;
367 	char shareopts[ZFS_MAXPROPLEN];
368 	libzfs_handle_t *libhandle;
369 
370 	dataset = get_zfs_dataset((sa_handle_t)sahandle, path, B_FALSE);
371 	if (dataset != NULL) {
372 		libhandle = libzfs_init();
373 		if (libhandle != NULL) {
374 			handle = zfs_open(libhandle, dataset,
375 			    ZFS_TYPE_FILESYSTEM);
376 			if (handle != NULL) {
377 				if (zfs_prop_get(handle, ZFS_PROP_SHARENFS,
378 				    shareopts, sizeof (shareopts), NULL, NULL,
379 				    0, B_FALSE) == 0 &&
380 				    strcmp(shareopts, "off") != 0) {
381 					ret = 1; /* it is shared */
382 				}
383 				zfs_close(handle);
384 			}
385 			libzfs_fini(libhandle);
386 		}
387 		free(dataset);
388 	}
389 	return (ret);
390 }
391 
392 /*
393  * find_or_create_group(handle, groupname, proto, *err)
394  *
395  * While walking the ZFS tree, we need to add shares to a defined
396  * group. If the group doesn't exist, create it first, making sure it
397  * is marked as a ZFS group.
398  *
399  * Note that all ZFS shares are in a subgroup of the top level group
400  * called "zfs".
401  */
402 
403 static sa_group_t
404 find_or_create_group(sa_handle_t handle, char *groupname, char *proto, int *err)
405 {
406 	sa_group_t group;
407 	sa_optionset_t optionset;
408 	int ret = SA_OK;
409 
410 	/*
411 	 * we check to see if the "zfs" group exists. Since this
412 	 * should be the top level group, we don't want the
413 	 * parent. This is to make sure the zfs group has been created
414 	 * and to created if it hasn't been.
415 	 */
416 	group = sa_get_group(handle, groupname);
417 	if (group == NULL) {
418 		group = sa_create_group(handle, groupname, &ret);
419 
420 		/* make sure this is flagged as a ZFS group */
421 		if (group != NULL)
422 			ret = sa_set_group_attr(group, "zfs", "true");
423 	}
424 	if (group != NULL) {
425 		if (proto != NULL) {
426 			optionset = sa_get_optionset(group, proto);
427 			if (optionset == NULL)
428 				optionset = sa_create_optionset(group, proto);
429 		}
430 	}
431 	if (err != NULL)
432 		*err = ret;
433 	return (group);
434 }
435 
436 /*
437  * find_or_create_zfs_subgroup(groupname, optstring, *err)
438  *
439  * ZFS shares will be in a subgroup of the "zfs" master group.  This
440  * function looks to see if the groupname exists and returns it if it
441  * does or else creates a new one with the specified name and returns
442  * that.  The "zfs" group will exist before we get here, but we make
443  * sure just in case.
444  *
445  * err must be a valid pointer.
446  */
447 
448 static sa_group_t
449 find_or_create_zfs_subgroup(sa_handle_t handle, char *groupname, char *proto,
450     char *optstring, int *err)
451 {
452 	sa_group_t group = NULL;
453 	sa_group_t zfs;
454 	char *name;
455 	char *options;
456 
457 	/* start with the top-level "zfs" group */
458 	zfs = sa_get_group(handle, "zfs");
459 	*err = SA_OK;
460 	if (zfs != NULL) {
461 		for (group = sa_get_sub_group(zfs); group != NULL;
462 		    group = sa_get_next_group(group)) {
463 			name = sa_get_group_attr(group, "name");
464 			if (name != NULL && strcmp(name, groupname) == 0) {
465 				/* have the group so break out of here */
466 				sa_free_attr_string(name);
467 				break;
468 			}
469 			if (name != NULL)
470 				sa_free_attr_string(name);
471 		}
472 
473 		if (group == NULL) {
474 			/*
475 			 * need to create the sub-group since it doesn't exist
476 			 */
477 			group = _sa_create_zfs_group(zfs, groupname);
478 			if (group != NULL)
479 				set_node_attr(group, "zfs", "true");
480 			if (strcmp(optstring, "on") == 0)
481 				optstring = "rw";
482 			if (group != NULL) {
483 				options = strdup(optstring);
484 				if (options != NULL) {
485 					*err = sa_parse_legacy_options(group,
486 					    options, proto);
487 
488 					/* If no optionset, add one */
489 					if (sa_get_optionset(group, proto) ==
490 					    NULL)
491 						(void) sa_create_optionset(
492 						    group, proto);
493 					free(options);
494 				} else {
495 					*err = SA_NO_MEMORY;
496 				}
497 			}
498 		} else if (proto != NULL && strcmp(proto, "smb") == 0) {
499 			*err = SA_PROP_SHARE_ONLY;
500 		}
501 	}
502 	return (group);
503 }
504 
505 /*
506  * zfs_construct_resource(share, name, base, dataset)
507  *
508  * Add a resource to the share using name as a template. If name ==
509  * NULL, then construct a name based on the dataset value.
510  * name.
511  */
512 static void
513 zfs_construct_resource(sa_share_t share, char *dataset)
514 {
515 	char buff[SA_MAX_RESOURCE_NAME + 1];
516 	int ret = SA_OK;
517 
518 	(void) snprintf(buff, SA_MAX_RESOURCE_NAME, "%s", dataset);
519 	sa_fix_resource_name(buff);
520 	(void) sa_add_resource(share, buff, SA_SHARE_TRANSIENT, &ret);
521 }
522 
523 /*
524  * zfs_inherited(handle, source, sourcestr)
525  *
526  * handle case of inherited share{nfs,smb}. Pulled out of sa_get_zfs_shares
527  * for readability.
528  */
529 static int
530 zfs_inherited(sa_handle_t handle, sa_share_t share, char *sourcestr,
531     char *shareopts, char *mountpoint, char *proto, char *dataset)
532 {
533 	int doshopt = 0;
534 	int err = SA_OK;
535 	sa_group_t group;
536 	sa_resource_t resource;
537 	uint64_t features;
538 
539 	/*
540 	 * Need to find the "real" parent sub-group. It may not be
541 	 * mounted, but it was identified in the "sourcestr"
542 	 * variable. The real parent not mounted can occur if
543 	 * "canmount=off and sharenfs=on".
544 	 */
545 	group = find_or_create_zfs_subgroup(handle, sourcestr, proto,
546 	    shareopts, &doshopt);
547 	if (group != NULL) {
548 		/*
549 		 * We may need the first share for resource
550 		 * prototype. We only care about it if it has a
551 		 * resource that sets a prefix value.
552 		 */
553 		if (share == NULL)
554 			share = _sa_add_share(group, mountpoint,
555 			    SA_SHARE_TRANSIENT, &err,
556 			    (uint64_t)SA_FEATURE_NONE);
557 		/*
558 		 * some options may only be on shares. If the opt
559 		 * string contains one of those, we put it just on the
560 		 * share.
561 		 */
562 		if (share != NULL && doshopt == SA_PROP_SHARE_ONLY) {
563 			char *options;
564 			options = strdup(shareopts);
565 			if (options != NULL) {
566 				set_node_attr(share, "dataset", dataset);
567 				err = sa_parse_legacy_options(share, options,
568 				    proto);
569 				set_node_attr(share, "dataset", NULL);
570 				free(options);
571 			}
572 			if (sa_get_optionset(group, proto) == NULL)
573 				(void) sa_create_optionset(group, proto);
574 		}
575 		features = sa_proto_get_featureset(proto);
576 		if (share != NULL && features & SA_FEATURE_RESOURCE) {
577 			/*
578 			 * We have a share and the protocol requires
579 			 * that at least one resource exist (probably
580 			 * SMB). We need to make sure that there is at
581 			 * least one.
582 			 */
583 			resource = sa_get_share_resource(share, NULL);
584 			if (resource == NULL) {
585 				zfs_construct_resource(share, dataset);
586 			}
587 		}
588 	} else {
589 		err = SA_NO_MEMORY;
590 	}
591 	return (err);
592 }
593 
594 /*
595  * zfs_notinherited()
596  *
597  * handle case where this is the top of a sub-group in ZFS. Pulled out
598  * of sa_get_zfs_shares for readability.
599  */
600 static int
601 zfs_notinherited(sa_group_t group, sa_share_t share, char *mountpoint,
602     char *shareopts, char *proto, char *dataset)
603 {
604 	int err = SA_OK;
605 	sa_resource_t resource;
606 	uint64_t features;
607 
608 	set_node_attr(group, "zfs", "true");
609 	if (share == NULL)
610 		share = _sa_add_share(group, mountpoint, SA_SHARE_TRANSIENT,
611 		    &err, (uint64_t)SA_FEATURE_NONE);
612 	if (err == SA_OK) {
613 		if (strcmp(shareopts, "on") == 0)
614 			shareopts = "";
615 		if (shareopts != NULL) {
616 			char *options;
617 			options = strdup(shareopts);
618 			if (options != NULL) {
619 				err = sa_parse_legacy_options(group, options,
620 				    proto);
621 				free(options);
622 			}
623 			if (err == SA_PROP_SHARE_ONLY) {
624 				/*
625 				 * Same as above, some properties may
626 				 * only be on shares, but due to the
627 				 * ZFS sub-groups being artificial, we
628 				 * sometimes get this and have to deal
629 				 * with it. We do it by attempting to
630 				 * put it on the share.
631 				 */
632 				options = strdup(shareopts);
633 				if (options != NULL) {
634 					err = sa_parse_legacy_options(share,
635 					    options, proto);
636 					free(options);
637 				}
638 			}
639 			/* unmark the share's changed state */
640 			set_node_attr(share, "changed", NULL);
641 		}
642 		features = sa_proto_get_featureset(proto);
643 		if (share != NULL && features & SA_FEATURE_RESOURCE) {
644 			/*
645 			 * We have a share and the protocol requires
646 			 * that at least one resource exist (probably
647 			 * SMB). We need to make sure that there is at
648 			 * least one.
649 			 */
650 			resource = sa_get_share_resource(share, NULL);
651 			if (resource == NULL) {
652 				zfs_construct_resource(share, dataset);
653 			}
654 		}
655 	}
656 	return (err);
657 }
658 
659 /*
660  * zfs_grp_error(err)
661  *
662  * Print group create error, but only once. If err is 0 do the
663  * print else don't.
664  */
665 
666 static void
667 zfs_grp_error(int err)
668 {
669 	if (err == 0) {
670 		/* only print error once */
671 		(void) fprintf(stderr, dgettext(TEXT_DOMAIN,
672 		    "Cannot create ZFS subgroup during initialization:"
673 		    " %s\n"), sa_errorstr(SA_SYSTEM_ERR));
674 	}
675 }
676 
677 /*
678  * zfs_process_share(handle, share, mountpoint, proto, source,
679  *     shareopts, sourcestr)
680  *
681  * Creates the subgroup, if necessary and adds shares and adds shares
682  * and properties.
683  */
684 static int
685 zfs_process_share(sa_handle_t handle, sa_group_t group, sa_share_t share,
686     char *mountpoint, char *proto, zprop_source_t source, char *shareopts,
687     char *sourcestr, char *dataset)
688 {
689 	int err = SA_OK;
690 
691 	if (source & ZPROP_SRC_INHERITED) {
692 		err = zfs_inherited(handle, share, sourcestr, shareopts,
693 		    mountpoint, proto, dataset);
694 	} else {
695 		group = find_or_create_zfs_subgroup(handle, dataset, proto,
696 		    shareopts, &err);
697 		if (group == NULL) {
698 			static int err = 0;
699 			/*
700 			 * there is a problem, but we can't do
701 			 * anything about it at this point so we issue
702 			 * a warning an move on.
703 			 */
704 			zfs_grp_error(err);
705 			err = 1;
706 		}
707 		set_node_attr(group, "zfs", "true");
708 		/*
709 		 * Add share with local opts via zfs_notinherited.
710 		 */
711 		err = zfs_notinherited(group, share, mountpoint, shareopts,
712 		    proto, dataset);
713 	}
714 	return (err);
715 }
716 
717 /*
718  * sa_get_zfs_shares(handle, groupname)
719  *
720  * Walk the mnttab for all zfs mounts and determine which are
721  * shared. Find or create the appropriate group/sub-group to contain
722  * the shares.
723  *
724  * All shares are in a sub-group that will hold the properties. This
725  * allows representing the inherited property model.
726  */
727 
728 int
729 sa_get_zfs_shares(sa_handle_t handle, char *groupname)
730 {
731 	sa_group_t group;
732 	sa_group_t zfsgroup;
733 	int legacy = 0;
734 	int err;
735 	zfs_handle_t **zlist;
736 	char shareopts[ZFS_MAXPROPLEN];
737 	sa_share_t share;
738 	zprop_source_t source;
739 	char sourcestr[ZFS_MAXPROPLEN];
740 	char mountpoint[ZFS_MAXPROPLEN];
741 	size_t count = 0, i;
742 	libzfs_handle_t *zfs_libhandle;
743 
744 	/*
745 	 * If we can't access libzfs, don't bother doing anything.
746 	 */
747 	zfs_libhandle = ((sa_handle_impl_t)handle)->zfs_libhandle;
748 	if (zfs_libhandle == NULL)
749 		return (SA_SYSTEM_ERR);
750 
751 	zfsgroup = find_or_create_group(handle, groupname, NULL, &err);
752 	if (zfsgroup == NULL)
753 		return (legacy);
754 
755 	/*
756 	 * need to walk the mounted ZFS pools and datasets to
757 	 * find shares that are possible.
758 	 */
759 	get_all_filesystems((sa_handle_impl_t)handle, &zlist, &count);
760 	qsort(zlist, count, sizeof (void *), mountpoint_compare);
761 
762 	group = zfsgroup;
763 	for (i = 0; i < count; i++) {
764 		char *dataset;
765 		int foundnfs = 0;
766 
767 		source = ZPROP_SRC_ALL;
768 		/* If no mountpoint, skip. */
769 		if (zfs_prop_get(zlist[i], ZFS_PROP_MOUNTPOINT,
770 		    mountpoint, sizeof (mountpoint), NULL, NULL, 0,
771 		    B_FALSE) != 0)
772 			continue;
773 
774 		/*
775 		 * zfs_get_name value must not be freed. It is just a
776 		 * pointer to a value in the handle.
777 		 */
778 		if ((dataset = (char *)zfs_get_name(zlist[i])) == NULL)
779 			continue;
780 
781 		/*
782 		 * only deal with "mounted" file systems since
783 		 * unmounted file systems can't actually be shared.
784 		 */
785 
786 		if (!zfs_is_mounted(zlist[i], NULL))
787 			continue;
788 
789 		if (zfs_prop_get(zlist[i], ZFS_PROP_SHARENFS, shareopts,
790 		    sizeof (shareopts), &source, sourcestr,
791 		    ZFS_MAXPROPLEN, B_FALSE) == 0 &&
792 		    strcmp(shareopts, "off") != 0) {
793 			/* it is shared so add to list */
794 			err = SA_OK;
795 			foundnfs = 1;
796 			share = sa_find_share(handle, mountpoint);
797 			if (share != NULL) {
798 				/*
799 				 * A zfs file system had been shared
800 				 * through traditional methods
801 				 * (share/dfstab or added to a non-zfs
802 				 * group.  Now it has been added to a
803 				 * ZFS group via the zfs
804 				 * command. Remove from previous
805 				 * config and setup with current
806 				 * options.
807 				 */
808 				err = sa_remove_share(share);
809 				share = NULL;
810 			}
811 			if (err == SA_OK) {
812 				err = zfs_process_share(handle, group,
813 				    share, mountpoint, "nfs", source,
814 				    shareopts, sourcestr, dataset);
815 			}
816 		}
817 		if (zfs_prop_get(zlist[i], ZFS_PROP_SHARESMB, shareopts,
818 		    sizeof (shareopts), &source, sourcestr,
819 		    ZFS_MAXPROPLEN, B_FALSE) == 0 &&
820 		    strcmp(shareopts, "off") != 0) {
821 			/* it is shared so add to list */
822 			err = SA_OK;
823 			share = sa_find_share(handle, mountpoint);
824 			if (share != NULL && !foundnfs) {
825 				/*
826 				 * A zfs file system had been shared
827 				 * through traditional methods
828 				 * (share/dfstab or added to a non-zfs
829 				 * group.  Now it has been added to a
830 				 * ZFS group via the zfs
831 				 * command. Remove from previous
832 				 * config and setup with current
833 				 * options.
834 				 */
835 				err = sa_remove_share(share);
836 				share = NULL;
837 			}
838 			if (err == SA_OK) {
839 				err = zfs_process_share(handle, group,
840 				    share, mountpoint, "smb", source,
841 				    shareopts, sourcestr, dataset);
842 			}
843 		}
844 	}
845 	/*
846 	 * Don't need to free the "zlist" variable since it is only a
847 	 * pointer to a cached value that will be freed when
848 	 * sa_fini() is called.
849 	 */
850 	return (legacy);
851 }
852 
853 #define	COMMAND		"/usr/sbin/zfs"
854 
855 /*
856  * sa_zfs_set_sharenfs(group, path, on)
857  *
858  * Update the "sharenfs" property on the path. If on is true, then set
859  * to the properties on the group or "on" if no properties are
860  * defined. Set to "off" if on is false.
861  */
862 
863 int
864 sa_zfs_set_sharenfs(sa_group_t group, char *path, int on)
865 {
866 	int ret = SA_NOT_IMPLEMENTED;
867 	char *command;
868 
869 	command = malloc(ZFS_MAXPROPLEN * 2);
870 	if (command != NULL) {
871 		char *opts = NULL;
872 		char *dataset = NULL;
873 		FILE *pfile;
874 		sa_handle_impl_t impl_handle;
875 		/* for now, NFS is always available for "zfs" */
876 		if (on) {
877 			opts = sa_proto_legacy_format("nfs", group, 1);
878 			if (opts != NULL && strlen(opts) == 0) {
879 				free(opts);
880 				opts = strdup("on");
881 			}
882 		}
883 
884 		impl_handle = (sa_handle_impl_t)sa_find_group_handle(group);
885 		assert(impl_handle != NULL);
886 		if (impl_handle != NULL)
887 			dataset = get_zfs_dataset(impl_handle, path, B_FALSE);
888 		else
889 			ret = SA_SYSTEM_ERR;
890 
891 		if (dataset != NULL) {
892 			(void) snprintf(command, ZFS_MAXPROPLEN * 2,
893 			    "%s set sharenfs=\"%s\" %s", COMMAND,
894 			    opts != NULL ? opts : "off", dataset);
895 			pfile = popen(command, "r");
896 			if (pfile != NULL) {
897 				ret = pclose(pfile);
898 				if (ret != 0)
899 					ret = SA_SYSTEM_ERR;
900 			}
901 		}
902 		if (opts != NULL)
903 			free(opts);
904 		if (dataset != NULL)
905 			free(dataset);
906 		free(command);
907 	}
908 	return (ret);
909 }
910 
911 /*
912  * add_resources(share, opt)
913  *
914  * Add resource properties to those in "opt".  Resources are prefixed
915  * with name=resourcename.
916  */
917 static char *
918 add_resources(sa_share_t share, char *opt)
919 {
920 	char *newopt = NULL;
921 	char *propstr;
922 	sa_resource_t resource;
923 
924 	newopt = strdup(opt);
925 	if (newopt == NULL)
926 		return (newopt);
927 
928 	for (resource = sa_get_share_resource(share, NULL);
929 	    resource != NULL;
930 	    resource = sa_get_next_resource(resource)) {
931 		char *name;
932 		size_t size;
933 
934 		name = sa_get_resource_attr(resource, "name");
935 		if (name == NULL) {
936 			free(newopt);
937 			return (NULL);
938 		}
939 		size = strlen(name) + strlen(opt) + sizeof ("name=") + 1;
940 		newopt = calloc(1, size);
941 		if (newopt != NULL)
942 			(void) snprintf(newopt, size, "%s,name=%s", opt, name);
943 		free(opt);
944 		opt = newopt;
945 		propstr = sa_proto_legacy_format("smb", resource, 0);
946 		if (propstr == NULL) {
947 			free(opt);
948 			return (NULL);
949 		}
950 		size = strlen(propstr) + strlen(opt) + 2;
951 		newopt = calloc(1, size);
952 		if (newopt != NULL)
953 			(void) snprintf(newopt, size, "%s,%s", opt, propstr);
954 		free(opt);
955 		opt = newopt;
956 	}
957 	return (opt);
958 }
959 
960 /*
961  * sa_zfs_set_sharesmb(group, path, on)
962  *
963  * Update the "sharesmb" property on the path. If on is true, then set
964  * to the properties on the group or "on" if no properties are
965  * defined. Set to "off" if on is false.
966  */
967 
968 int
969 sa_zfs_set_sharesmb(sa_group_t group, char *path, int on)
970 {
971 	int ret = SA_NOT_IMPLEMENTED;
972 	char *command;
973 	sa_share_t share;
974 
975 	/* In case SMB not enabled */
976 	if (sa_get_optionset(group, "smb") == NULL)
977 		return (SA_NOT_SUPPORTED);
978 
979 	command = malloc(ZFS_MAXPROPLEN * 2);
980 	if (command != NULL) {
981 		char *opts = NULL;
982 		char *dataset = NULL;
983 		FILE *pfile;
984 		sa_handle_impl_t impl_handle;
985 
986 		if (on) {
987 			char *newopt;
988 
989 			share = sa_get_share(group, NULL);
990 			opts = sa_proto_legacy_format("smb", share, 1);
991 			if (opts != NULL && strlen(opts) == 0) {
992 				free(opts);
993 				opts = strdup("on");
994 			}
995 			newopt = add_resources(opts, share);
996 			free(opts);
997 			opts = newopt;
998 		}
999 
1000 		impl_handle = (sa_handle_impl_t)sa_find_group_handle(group);
1001 		assert(impl_handle != NULL);
1002 		if (impl_handle != NULL)
1003 			dataset = get_zfs_dataset(impl_handle, path, B_FALSE);
1004 		else
1005 			ret = SA_SYSTEM_ERR;
1006 
1007 		if (dataset != NULL) {
1008 			(void) snprintf(command, ZFS_MAXPROPLEN * 2,
1009 			    "echo %s set sharesmb=\"%s\" %s", COMMAND,
1010 			    opts != NULL ? opts : "off", dataset);
1011 			pfile = popen(command, "r");
1012 			if (pfile != NULL) {
1013 				ret = pclose(pfile);
1014 				if (ret != 0)
1015 					ret = SA_SYSTEM_ERR;
1016 			}
1017 		}
1018 		if (opts != NULL)
1019 			free(opts);
1020 		if (dataset != NULL)
1021 			free(dataset);
1022 		free(command);
1023 	}
1024 	return (ret);
1025 }
1026 
1027 /*
1028  * sa_zfs_update(group)
1029  *
1030  * call back to ZFS to update the share if necessary.
1031  * Don't do it if it isn't a real change.
1032  */
1033 int
1034 sa_zfs_update(sa_group_t group)
1035 {
1036 	sa_optionset_t protopt;
1037 	sa_group_t parent;
1038 	char *command;
1039 	char *optstring;
1040 	int ret = SA_OK;
1041 	int doupdate = 0;
1042 	FILE *pfile;
1043 
1044 	if (sa_is_share(group))
1045 		parent = sa_get_parent_group(group);
1046 	else
1047 		parent = group;
1048 
1049 	if (parent != NULL) {
1050 		command = malloc(ZFS_MAXPROPLEN * 2);
1051 		if (command == NULL)
1052 			return (SA_NO_MEMORY);
1053 
1054 		*command = '\0';
1055 		for (protopt = sa_get_optionset(parent, NULL); protopt != NULL;
1056 		    protopt = sa_get_next_optionset(protopt)) {
1057 
1058 			char *proto = sa_get_optionset_attr(protopt, "type");
1059 			char *path;
1060 			char *dataset = NULL;
1061 			char *zfsopts = NULL;
1062 
1063 			if (sa_is_share(group)) {
1064 				path = sa_get_share_attr((sa_share_t)group,
1065 				    "path");
1066 				if (path != NULL) {
1067 					sa_handle_impl_t impl_handle;
1068 
1069 					impl_handle = sa_find_group_handle(
1070 					    group);
1071 					if (impl_handle != NULL)
1072 						dataset = get_zfs_dataset(
1073 						    impl_handle, path, B_FALSE);
1074 					else
1075 						ret = SA_SYSTEM_ERR;
1076 
1077 					sa_free_attr_string(path);
1078 				}
1079 			} else {
1080 				dataset = sa_get_group_attr(group, "name");
1081 			}
1082 			/* update only when there is an optstring found */
1083 			doupdate = 0;
1084 			if (proto != NULL && dataset != NULL) {
1085 				optstring = sa_proto_legacy_format(proto,
1086 				    group, 1);
1087 				zfsopts = get_zfs_property(dataset,
1088 				    ZFS_PROP_SHARENFS);
1089 
1090 				if (optstring != NULL && zfsopts != NULL) {
1091 					if (strcmp(optstring, zfsopts) != 0)
1092 						doupdate++;
1093 				}
1094 				if (doupdate) {
1095 					if (optstring != NULL &&
1096 					    strlen(optstring) > 0) {
1097 						(void) snprintf(command,
1098 						    ZFS_MAXPROPLEN * 2,
1099 						    "%s set sharenfs=%s %s",
1100 						    COMMAND,
1101 						    optstring, dataset);
1102 					} else {
1103 						(void) snprintf(command,
1104 						    ZFS_MAXPROPLEN * 2,
1105 						    "%s set sharenfs=on %s",
1106 						    COMMAND,
1107 						    dataset);
1108 					}
1109 					pfile = popen(command, "r");
1110 					if (pfile != NULL)
1111 						ret = pclose(pfile);
1112 					switch (ret) {
1113 					default:
1114 					case 1:
1115 						ret = SA_SYSTEM_ERR;
1116 						break;
1117 					case 2:
1118 						ret = SA_SYNTAX_ERR;
1119 						break;
1120 					case 0:
1121 						break;
1122 					}
1123 				}
1124 				if (optstring != NULL)
1125 					free(optstring);
1126 				if (zfsopts != NULL)
1127 					free(zfsopts);
1128 			}
1129 			if (proto != NULL)
1130 				sa_free_attr_string(proto);
1131 			if (dataset != NULL)
1132 				free(dataset);
1133 		}
1134 		free(command);
1135 	}
1136 	return (ret);
1137 }
1138 
1139 /*
1140  * sa_group_is_zfs(group)
1141  *
1142  * Given the group, determine if the zfs attribute is set.
1143  */
1144 
1145 int
1146 sa_group_is_zfs(sa_group_t group)
1147 {
1148 	char *zfs;
1149 	int ret = 0;
1150 
1151 	zfs = sa_get_group_attr(group, "zfs");
1152 	if (zfs != NULL) {
1153 		ret = 1;
1154 		sa_free_attr_string(zfs);
1155 	}
1156 	return (ret);
1157 }
1158 
1159 /*
1160  * sa_path_is_zfs(path)
1161  *
1162  * Check to see if the file system path represents is of type "zfs".
1163  */
1164 
1165 int
1166 sa_path_is_zfs(char *path)
1167 {
1168 	char *fstype;
1169 	int ret = 0;
1170 
1171 	fstype = sa_fstype(path);
1172 	if (fstype != NULL && strcmp(fstype, "zfs") == 0)
1173 		ret = 1;
1174 	if (fstype != NULL)
1175 		sa_free_fstype(fstype);
1176 	return (ret);
1177 }
1178 
1179 int
1180 sa_sharetab_fill_zfs(sa_share_t share, share_t *sh, char *proto)
1181 {
1182 	char *path;
1183 
1184 	/* Make sure path is valid */
1185 
1186 	path = sa_get_share_attr(share, "path");
1187 	if (path != NULL) {
1188 		(void) memset(sh, 0, sizeof (sh));
1189 		(void) sa_fillshare(share, proto, sh);
1190 		sa_free_attr_string(path);
1191 		return (0);
1192 	} else
1193 		return (1);
1194 }
1195 
1196 #define	SMAX(i, j)	\
1197 	if ((j) > (i)) { \
1198 		(i) = (j); \
1199 	}
1200 
1201 int
1202 sa_share_zfs(sa_share_t share, char *path, share_t *sh,
1203     void *exportdata, zfs_share_op_t operation)
1204 {
1205 	libzfs_handle_t *libhandle;
1206 	sa_group_t group;
1207 	sa_handle_t sahandle;
1208 	char *dataset;
1209 	int err = EINVAL;
1210 	int i, j;
1211 	char newpath[MAXPATHLEN];
1212 	char *pathp;
1213 
1214 	/*
1215 	 * First find the dataset name
1216 	 */
1217 	if ((group = sa_get_parent_group(share)) == NULL)  {
1218 		return (SA_SYSTEM_ERR);
1219 	}
1220 	if ((sahandle = sa_find_group_handle(group)) == NULL) {
1221 		return (SA_SYSTEM_ERR);
1222 	}
1223 
1224 	/*
1225 	 * If get_zfs_dataset fails, see if it is a subdirectory
1226 	 */
1227 
1228 	pathp = path;
1229 	while ((dataset = get_zfs_dataset(sahandle, pathp, B_TRUE)) == NULL) {
1230 		char *p;
1231 
1232 		if (pathp == path) {
1233 			(void) strlcpy(newpath, path, sizeof (newpath));
1234 			pathp = newpath;
1235 		}
1236 
1237 		/*
1238 		 * chop off part of path, but if we are at root then
1239 		 * make sure path is a /
1240 		 */
1241 		if ((strlen(pathp) > 1) && (p = strrchr(pathp, '/'))) {
1242 			if (pathp == p) {
1243 				*(p + 1) = '\0';  /* skip over /, root case */
1244 			} else {
1245 				*p = '\0';
1246 			}
1247 		} else {
1248 			return (SA_SYSTEM_ERR);
1249 		}
1250 	}
1251 
1252 	libhandle = libzfs_init();
1253 	if (libhandle != NULL) {
1254 
1255 		i = (sh->sh_path ? strlen(sh->sh_path) : 0);
1256 		sh->sh_size = i;
1257 
1258 		j = (sh->sh_res ? strlen(sh->sh_res) : 0);
1259 		sh->sh_size += j;
1260 		SMAX(i, j);
1261 
1262 		j = (sh->sh_fstype ? strlen(sh->sh_fstype) : 0);
1263 		sh->sh_size += j;
1264 		SMAX(i, j);
1265 
1266 		j = (sh->sh_opts ? strlen(sh->sh_opts) : 0);
1267 		sh->sh_size += j;
1268 		SMAX(i, j);
1269 
1270 		j = (sh->sh_descr ? strlen(sh->sh_descr) : 0);
1271 		sh->sh_size += j;
1272 		SMAX(i, j);
1273 		err = zfs_deleg_share_nfs(libhandle, dataset, path,
1274 		    exportdata, sh, i, operation);
1275 		libzfs_fini(libhandle);
1276 	}
1277 	free(dataset);
1278 	return (err);
1279 }
1280