xref: /illumos-gate/usr/src/cmd/smbsrv/smbd/smbd_vss.c (revision b02947bf393d39f68e6c7fa8ccb98688f7f9c407)
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 (c) 2009, 2010, Oracle and/or its affiliates. All rights reserved.
24  * Copyright 2018 Nexenta Systems, Inc.  All rights reserved.
25  * Copyright 2016 Martin Matuska. All rights reserved.
26  */
27 
28 #include <synch.h>
29 #include <pthread.h>
30 #include <unistd.h>
31 #include <string.h>
32 #include <strings.h>
33 #include <sys/errno.h>
34 #include <libzfs.h>
35 
36 #include <smbsrv/libsmb.h>
37 #include <smbsrv/libsmbns.h>
38 #include <smbsrv/libmlsvc.h>
39 #include <smbsrv/smbinfo.h>
40 #include "smbd.h"
41 
42 /*
43  * This file supports three basic functions that all use the
44  * the zfs_iter_snapshots function to get the snapshot info
45  * from ZFS.  If the filesystem is not ZFS, the an error is sent
46  * to the caller (door functions in this case) with the count of
47  * zero in the case of smbd_vss_get_count.  Each function
48  * is expecting a path that is the root of the dataset.
49  * The basic idea is to define a structure for the data and
50  * an iterator function that will be called for every snapshot
51  * in the dataset that was opened.  The iterator function gets
52  * a zfs_handle_t(that needs to be closed) for the snapshot
53  * and a pointer to the structure of data defined passed to it.
54  * If the iterator function returns a non-zero value, no more
55  * snapshots will be processed.  There is no guarantee in the
56  * order in which the snapshots are processed.
57  *
58  * The structure of this file is:
59  * Three structures that are used between the iterator functions
60  * and "main" functions
61  * The 3 "main" functions
62  * Support functions
63  * The 3 iterator functions
64  */
65 
66 /*
67  * The maximum number of snapshots returned per request.
68  */
69 #define	SMBD_VSS_SNAPSHOT_MAX	725
70 
71 static void smbd_vss_time2gmttoken(time_t time, char *gmttoken);
72 static int smbd_vss_cmp_time(const void *a, const void *b);
73 static int smbd_vss_iterate_count(zfs_handle_t *zhp, void *data);
74 static int smbd_vss_iterate_get_uint64_date(zfs_handle_t *zhp, void *data);
75 static int smbd_vss_iterate_map_gmttoken(zfs_handle_t *zhp, void *data);
76 
77 typedef struct smbd_vss_count {
78 	int vc_count;
79 } smbd_vss_count_t;
80 
81 /*
82  * gd_count how many @GMT tokens are expected
83  * gd_return_count how many @GMT tokens are being returned
84  * gd_gmt_array array of the @GMT token with max size of gd_count
85  */
86 typedef struct smbd_vss_get_uint64_date {
87 	int gd_count;
88 	int gd_return_count;
89 	uint64_t *gd_gmt_array;
90 } smbd_vss_get_uint64_date_t;
91 
92 typedef struct smbd_vss_map_gmttoken {
93 	time_t mg_snaptime;
94 	char *mg_snapname;
95 } smbd_vss_map_gmttoken_t;
96 
97 
98 /*
99  * path - path of the dataset
100  * count - return value of the number of snapshots for the dataset
101  */
102 int
103 smbd_vss_get_count(const char *path, uint32_t *count)
104 {
105 	char dataset[MAXPATHLEN];
106 	libzfs_handle_t *libhd;
107 	zfs_handle_t *zfshd;
108 	smbd_vss_count_t vss_count;
109 
110 	bzero(&vss_count, sizeof (smbd_vss_count_t));
111 	*count = 0;
112 
113 	if ((libhd = libzfs_init()) == NULL)
114 		return (-1);
115 
116 	if (smb_getdataset(libhd, path, dataset, MAXPATHLEN) != 0) {
117 		libzfs_fini(libhd);
118 		return (-1);
119 	}
120 
121 	if ((zfshd = zfs_open(libhd, dataset, ZFS_TYPE_DATASET)) == NULL) {
122 		libzfs_fini(libhd);
123 		return (-1);
124 	}
125 
126 	(void) zfs_iter_snapshots(zfshd, B_FALSE, smbd_vss_iterate_count,
127 	    (void *)&vss_count);
128 
129 	if (vss_count.vc_count > SMBD_VSS_SNAPSHOT_MAX)
130 		vss_count.vc_count = SMBD_VSS_SNAPSHOT_MAX;
131 
132 	*count = vss_count.vc_count;
133 	zfs_close(zfshd);
134 	libzfs_fini(libhd);
135 	return (0);
136 }
137 
138 /*
139  * path - is the path of the dataset
140  * count - is the maxium number of GMT tokens allowed to be returned
141  * return_count - is how many should be returned
142  * num_gmttokens - how many gmttokens in gmttokenp (0 if error)
143  * gmttokenp - array of @GMT tokens (even if zero, elements still need
144  * to be freed)
145  */
146 
147 void
148 smbd_vss_get_snapshots(const char *path, uint32_t count,
149     uint32_t *return_count, uint32_t *num_gmttokens, char **gmttokenp)
150 {
151 	char dataset[MAXPATHLEN];
152 	libzfs_handle_t *libhd;
153 	zfs_handle_t *zfshd;
154 	smbd_vss_get_uint64_date_t vss_uint64_date;
155 	int i;
156 	uint64_t *timep;
157 
158 	*return_count = 0;
159 	*num_gmttokens = 0;
160 
161 	if (count == 0)
162 		return;
163 
164 	if (count > SMBD_VSS_SNAPSHOT_MAX)
165 		count = SMBD_VSS_SNAPSHOT_MAX;
166 
167 	vss_uint64_date.gd_count = count;
168 	vss_uint64_date.gd_return_count = 0;
169 	vss_uint64_date.gd_gmt_array = malloc(count * sizeof (uint64_t));
170 
171 	if (vss_uint64_date.gd_gmt_array == NULL)
172 		return;
173 
174 	if ((libhd = libzfs_init()) == NULL) {
175 		free(vss_uint64_date.gd_gmt_array);
176 		return;
177 	}
178 
179 	if (smb_getdataset(libhd, path, dataset, MAXPATHLEN) != 0) {
180 		free(vss_uint64_date.gd_gmt_array);
181 		libzfs_fini(libhd);
182 		return;
183 	}
184 
185 	if ((zfshd = zfs_open(libhd, dataset, ZFS_TYPE_DATASET)) == NULL) {
186 		free(vss_uint64_date.gd_gmt_array);
187 		libzfs_fini(libhd);
188 		return;
189 	}
190 
191 	(void) zfs_iter_snapshots(zfshd, B_FALSE,
192 	    smbd_vss_iterate_get_uint64_date, (void *)&vss_uint64_date);
193 
194 	*num_gmttokens = vss_uint64_date.gd_return_count;
195 	*return_count = vss_uint64_date.gd_return_count;
196 
197 	/*
198 	 * Sort the list since neither zfs nor the client sorts it.
199 	 */
200 	qsort((char *)vss_uint64_date.gd_gmt_array,
201 	    vss_uint64_date.gd_return_count,
202 	    sizeof (uint64_t), smbd_vss_cmp_time);
203 
204 	timep = vss_uint64_date.gd_gmt_array;
205 
206 	for (i = 0; i < vss_uint64_date.gd_return_count; i++) {
207 		*gmttokenp = malloc(SMB_VSS_GMT_SIZE);
208 
209 		if (*gmttokenp)
210 			smbd_vss_time2gmttoken(*timep, *gmttokenp);
211 		else
212 			vss_uint64_date.gd_return_count = 0;
213 
214 		timep++;
215 		gmttokenp++;
216 	}
217 
218 	free(vss_uint64_date.gd_gmt_array);
219 	zfs_close(zfshd);
220 	libzfs_fini(libhd);
221 }
222 
223 static const char
224 smbd_vss_gmttoken_fmt[] = "@GMT-%Y.%m.%d-%H.%M.%S";
225 
226 /*
227  * path - path of the dataset for the operation
228  * gmttoken - the @GMT token to be looked up
229  * toktime - time_t used if gmttoken == NULL
230  * snapname - the snapshot name to be returned [MAXPATHLEN]
231  *
232  * Here we are going to get the snapshot name from the @GMT token
233  * The snapname returned by ZFS is : <dataset name>@<snapshot name>
234  * So we are going to make sure there is the @ symbol in
235  * the right place and then just return the snapshot name
236  */
237 int
238 smbd_vss_map_gmttoken(const char *path, char *gmttoken, time_t toktime,
239 	char *snapname)
240 {
241 	char dataset[MAXPATHLEN];
242 	libzfs_handle_t *libhd;
243 	zfs_handle_t *zfshd;
244 	smbd_vss_map_gmttoken_t vss_map_gmttoken;
245 	char *zsnap;
246 	const char *lsnap;
247 	struct tm tm;
248 
249 	if (gmttoken != NULL && *gmttoken == '@' &&
250 	    strptime(gmttoken, smbd_vss_gmttoken_fmt, &tm) != NULL) {
251 		toktime = timegm(&tm);
252 	}
253 
254 	vss_map_gmttoken.mg_snaptime = toktime;
255 	vss_map_gmttoken.mg_snapname = snapname;
256 	*snapname = '\0';
257 
258 	if ((libhd = libzfs_init()) == NULL)
259 		return (-1);
260 
261 	if (smb_getdataset(libhd, path, dataset, MAXPATHLEN) != 0) {
262 		libzfs_fini(libhd);
263 		return (-1);
264 	}
265 
266 	if ((zfshd = zfs_open(libhd, dataset, ZFS_TYPE_DATASET)) == NULL) {
267 		libzfs_fini(libhd);
268 		return (-1);
269 	}
270 
271 	(void) zfs_iter_snapshots(zfshd, B_FALSE, smbd_vss_iterate_map_gmttoken,
272 	    (void *)&vss_map_gmttoken);
273 
274 	/* compare the zfs snapshot name and the local snap name */
275 	zsnap = snapname;
276 	lsnap = dataset;
277 	while ((*lsnap != '\0') && (*zsnap != '\0') && (*lsnap == *zsnap)) {
278 		zsnap++;
279 		lsnap++;
280 	}
281 
282 	/* Now we should be passed the dataset name */
283 	if ((*zsnap == '@') && (*lsnap == '\0')) {
284 		zsnap++;
285 		(void) strlcpy(snapname, zsnap, MAXPATHLEN);
286 	} else {
287 		*snapname = '\0';
288 	}
289 
290 	zfs_close(zfshd);
291 	libzfs_fini(libhd);
292 	return (0);
293 }
294 
295 static void
296 smbd_vss_time2gmttoken(time_t time, char *gmttoken)
297 {
298 	struct tm t;
299 
300 	(void) gmtime_r(&time, &t);
301 
302 	(void) strftime(gmttoken, SMB_VSS_GMT_SIZE,
303 	    smbd_vss_gmttoken_fmt, &t);
304 }
305 
306 static int
307 smbd_vss_cmp_time(const void *a, const void *b)
308 {
309 	if (*(uint64_t *)a < *(uint64_t *)b)
310 		return (1);
311 	if (*(uint64_t *)a == *(uint64_t *)b)
312 		return (0);
313 	return (-1);
314 }
315 
316 /*
317  * ZFS snapshot iterator to count snapshots.
318  * Note: libzfs expects us to close the handle.
319  * Return 0 to continue iterating or non-zreo to terminate the iteration.
320  */
321 static int
322 smbd_vss_iterate_count(zfs_handle_t *zhp, void *data)
323 {
324 	smbd_vss_count_t *vss_data = data;
325 
326 	if (vss_data->vc_count < SMBD_VSS_SNAPSHOT_MAX) {
327 		vss_data->vc_count++;
328 		zfs_close(zhp);
329 		return (0);
330 	}
331 
332 	zfs_close(zhp);
333 	return (-1);
334 }
335 
336 /*
337  * ZFS snapshot iterator to get snapshot creation time.
338  * Note: libzfs expects us to close the handle.
339  * Return 0 to continue iterating or non-zreo to terminate the iteration.
340  */
341 static int
342 smbd_vss_iterate_get_uint64_date(zfs_handle_t *zhp, void *data)
343 {
344 	smbd_vss_get_uint64_date_t *vss_data = data;
345 	int count;
346 
347 	count = vss_data->gd_return_count;
348 
349 	if (count < vss_data->gd_count) {
350 		vss_data->gd_gmt_array[count] =
351 		    zfs_prop_get_int(zhp, ZFS_PROP_CREATION);
352 		vss_data->gd_return_count++;
353 		zfs_close(zhp);
354 		return (0);
355 	}
356 
357 	zfs_close(zhp);
358 	return (-1);
359 }
360 
361 /*
362  * ZFS snapshot iterator to map a snapshot creation time to a token.
363  * Note: libzfs expects us to close the handle.
364  * Return 0 to continue iterating or non-zreo to terminate the iteration.
365  */
366 static int
367 smbd_vss_iterate_map_gmttoken(zfs_handle_t *zhp, void *data)
368 {
369 	smbd_vss_map_gmttoken_t *vss_data = data;
370 	time_t time;
371 
372 	time = (time_t)zfs_prop_get_int(zhp, ZFS_PROP_CREATION);
373 	if (time == vss_data->mg_snaptime) {
374 		(void) strlcpy(vss_data->mg_snapname, zfs_get_name(zhp),
375 		    MAXPATHLEN);
376 
377 		/* we found a match, do not process anymore snapshots */
378 		zfs_close(zhp);
379 		return (-1);
380 	}
381 
382 	zfs_close(zhp);
383 	return (0);
384 }
385