xref: /titanic_51/usr/src/uts/common/fs/smbsrv/smb_vss.c (revision 87d5c1f9b787004b82b01c61d7159df8a96de8e0)
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  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 /*
27  * Volume Copy Shadow Services (VSS) provides a way for users to
28  * restore/recover deleted files/directories.
29  * For the server to support VSS for Microsoft clients, there is
30  * two basic functions that need to be implemented.
31  * The first is to intercept the NT_TRANSACT_IOCTL command with
32  * the function code of FSCTL_SRV_ENUMERATE_SNAPSHOTS (0x00144064).
33  * This is to report the count or the count and list of snapshots
34  * for that share.
35  * The second function need to trap commands with the
36  * SMB_FLAGS2_REPARSE_PATH bit set in the smb header.  This bit
37  * means that there is a @GMT token in path that needs to be
38  * processed.  The @GMT token means to process this command, but
39  * in the snapshot.
40  */
41 
42 #include <smbsrv/smb_incl.h>
43 #include <smbsrv/winioctl.h>
44 #include <smbsrv/ntstatus.h>
45 #include <smbsrv/smb_door_svc.h>
46 
47 /* Size of the token on the wire due to encoding */
48 #define	SMB_VSS_GMT_NET_SIZE(sr) (smb_ascii_or_unicode_null_len(sr) * \
49     SMB_VSS_GMT_SIZE)
50 
51 #define	SMB_VSS_COUNT_SIZE 16
52 
53 static boolean_t smb_vss_is_gmttoken(const char *str);
54 static const char *smb_vss_find_gmttoken(const char *path);
55 static int smb_vss_get_fsmountpath(smb_request_t *sr, char *buf,
56     uint32_t buflen);
57 static uint32_t smb_vss_encode_gmttokens(smb_request_t *sr, smb_xa_t *xa,
58     int32_t count, smb_dr_return_gmttokens_t *snap_data);
59 static void smb_vss_remove_first_token_from_path(char *c);
60 
61 /*
62  * This is to respond to the nt_transact_ioctl to either respond with the
63  * number of snapshots, or to respond with the list.  It needs to be sorted
64  * before the reply.  If the the max data bytes to return is
65  * SMB_VSS_COUNT_SIZE, then all that is requested is the count, otherwise
66  * return the count and the list of @GMT tokens (one token for each
67  * snapshot).
68  */
69 uint32_t
70 smb_vss_ioctl_enumerate_snaps(smb_request_t *sr, smb_xa_t *xa)
71 {
72 	uint32_t count = 0;
73 	char *root_path;
74 	uint32_t status = NT_STATUS_SUCCESS;
75 	smb_dr_return_gmttokens_t gmttokens;
76 
77 	if (xa->smb_mdrcnt < SMB_VSS_COUNT_SIZE)
78 		return (NT_STATUS_INVALID_PARAMETER);
79 
80 	root_path  = kmem_zalloc(MAXPATHLEN, KM_SLEEP);
81 	if (smb_vss_get_fsmountpath(sr, root_path, MAXPATHLEN) != 0)
82 		return (NT_STATUS_INVALID_PARAMETER);
83 
84 	if (xa->smb_mdrcnt == SMB_VSS_COUNT_SIZE) {
85 		count = smb_upcall_vss_get_count(root_path);
86 		if (smb_mbc_encodef(&xa->rep_data_mb, "lllw", count, 0,
87 		    (count * SMB_VSS_GMT_NET_SIZE(sr) +
88 		    smb_ascii_or_unicode_null_len(sr)), 0) != 0) {
89 			status = NT_STATUS_INVALID_PARAMETER;
90 		}
91 	} else {
92 		count = xa->smb_mdrcnt / SMB_VSS_GMT_NET_SIZE(sr);
93 
94 		smb_upcall_vss_get_snapshots(root_path, count, &gmttokens);
95 
96 		status = smb_vss_encode_gmttokens(sr, xa, count, &gmttokens);
97 
98 		smb_upcall_vss_get_snapshots_free(&gmttokens);
99 	}
100 
101 	kmem_free(root_path, MAXPATHLEN);
102 	return (status);
103 }
104 
105 /*
106  * sr - the request info, used to find root of dataset,
107  *      unicode or ascii, where the share is rooted in the
108  *      dataset
109  * root_node - root of the share
110  * cur_node - where in the share for the command
111  * buf - is the path for the command to be processed
112  *       returned without @GMT if processed
113  * vss_cur_node - returned value for the snapshot version
114  *                of the cur_node
115  * vss_root_node - returned value for the snapshot version
116  *                 of the root_node
117  *
118  * This routine is the processing for handling the
119  * SMB_FLAGS2_REPARSE_PATH bit being set in the smb header.
120  *
121  * By using the cur_node passed in, a new node is found or
122  * created that is the same place in the directory tree, but
123  * in the snapshot. We also use root_node to do the same for
124  * the root.
125  * One the new smb node is found, the path is modified by
126  * removing the @GMT token from the path in the buf.
127  */
128 int
129 smb_vss_lookup_nodes(smb_request_t *sr, smb_node_t *root_node,
130     smb_node_t *cur_node, char *buf, smb_node_t **vss_cur_node,
131     smb_node_t **vss_root_node)
132 {
133 	const char *p;
134 	char *rootpath;
135 	char *snapname;
136 	char *nodepath;
137 	char gmttoken[SMB_VSS_GMT_SIZE];
138 	smb_attr_t attr;
139 	vnode_t *fsrootvp;
140 	vnode_t *vp = NULL;
141 	int err = 0;
142 
143 	if (sr->tid_tree == NULL)
144 		return (ESTALE);
145 
146 	ASSERT(sr->tid_tree->t_snode);
147 	ASSERT(sr->tid_tree->t_snode->vp);
148 	ASSERT(sr->tid_tree->t_snode->vp->v_vfsp);
149 
150 	if ((p = smb_vss_find_gmttoken(buf)) == NULL)
151 		return (ENOENT);
152 
153 	bcopy(p, gmttoken, SMB_VSS_GMT_SIZE);
154 	gmttoken[SMB_VSS_GMT_SIZE - 1] = '\0';
155 
156 	err = VFS_ROOT(sr->tid_tree->t_snode->vp->v_vfsp, &fsrootvp);
157 	if (err != 0)
158 		return (err);
159 
160 	rootpath = kmem_alloc(MAXPATHLEN, KM_SLEEP);
161 	snapname = kmem_alloc(MAXNAMELEN, KM_SLEEP);
162 	nodepath = kmem_alloc(MAXPATHLEN, KM_SLEEP);
163 
164 	err = smb_vss_get_fsmountpath(sr, rootpath, MAXPATHLEN);
165 	if (err != 0)
166 		goto error;
167 
168 	*snapname = '\0';
169 
170 	smb_upcall_vss_map_gmttoken(rootpath, gmttoken, snapname);
171 
172 	if (!*snapname) {
173 		err = ENOENT;
174 		goto error;
175 	}
176 
177 	/* note the value of root_node->vp */
178 	err = vnodetopath(fsrootvp, root_node->vp, nodepath,
179 	    MAXPATHLEN, kcred);
180 
181 	if (err != 0)
182 		goto error;
183 
184 	(void) snprintf(rootpath, MAXPATHLEN, ".zfs/snapshot/%s/%s",
185 	    snapname, nodepath);
186 
187 	vp = smb_lookuppathvptovp(sr, rootpath, fsrootvp, fsrootvp);
188 
189 	if (vp) {
190 		/* note the value of cur_node->vp */
191 		err = vnodetopath(fsrootvp, cur_node->vp, nodepath,
192 		    MAXPATHLEN, kcred);
193 		if (err != 0) {
194 			VN_RELE(vp);
195 			goto error;
196 		}
197 
198 		*vss_root_node = smb_node_lookup(sr, NULL, kcred, vp,
199 		    gmttoken, cur_node, NULL, &attr);
200 		VN_RELE(vp);
201 
202 		if (*vss_root_node == NULL) {
203 			err = ENOENT;
204 			goto error;
205 		}
206 
207 		(void) snprintf(rootpath, MAXPATHLEN, ".zfs/snapshot/%s/%s",
208 		    snapname, nodepath);
209 
210 
211 		vp = smb_lookuppathvptovp(sr, rootpath, fsrootvp, fsrootvp);
212 
213 		if (vp) {
214 			*vss_cur_node = smb_node_lookup(sr, NULL, kcred, vp,
215 			    gmttoken, cur_node, NULL, &attr);
216 			VN_RELE(vp);
217 
218 			if (*vss_cur_node != NULL) {
219 				smb_vss_remove_first_token_from_path(buf);
220 			} else {
221 				(void) smb_node_release(*vss_root_node);
222 				err = ENOENT;
223 			}
224 		} else {
225 			(void) smb_node_release(*vss_root_node);
226 			err = ENOENT;
227 		}
228 	} else {
229 		err = ENOENT;
230 	}
231 
232 error:
233 	VN_RELE(fsrootvp);
234 	kmem_free(rootpath, MAXPATHLEN);
235 	kmem_free(snapname, MAXNAMELEN);
236 	kmem_free(nodepath, MAXPATHLEN);
237 
238 	return (err);
239 }
240 
241 static boolean_t
242 smb_vss_is_gmttoken(const char *s)
243 {
244 	char *t = "@GMT-NNNN.NN.NN-NN.NN.NN";
245 	const char *str;
246 	char *template;
247 
248 	template = t;
249 	str = s;
250 
251 	while (*template) {
252 		if (*template == 'N') {
253 			if (!mts_isdigit(*str))
254 				return (B_FALSE);
255 		} else if (*template != *str) {
256 			return (B_FALSE);
257 		}
258 
259 		template++;
260 		str++;
261 	}
262 
263 	/* Make sure it is JUST the @GMT token */
264 	if ((*str == '\0') || (*str == '/'))
265 		return (B_TRUE);
266 
267 	return (B_FALSE);
268 }
269 
270 static const char *
271 smb_vss_find_gmttoken(const char *path)
272 {
273 	const char *p;
274 
275 	p = path;
276 
277 	while (*p) {
278 		if (smb_vss_is_gmttoken(p))
279 			return (p);
280 		p++;
281 	}
282 	return (NULL);
283 }
284 
285 static int
286 smb_vss_get_fsmountpath(smb_request_t *sr, char *buf, uint32_t buflen)
287 {
288 	vnode_t *vp, *root_vp;
289 	vfs_t *vfsp;
290 	int err;
291 
292 	ASSERT(sr->tid_tree);
293 	ASSERT(sr->tid_tree->t_snode);
294 	ASSERT(sr->tid_tree->t_snode->vp);
295 	ASSERT(sr->tid_tree->t_snode->vp->v_vfsp);
296 
297 	vp = sr->tid_tree->t_snode->vp;
298 	vfsp = vp->v_vfsp;
299 
300 	if (VFS_ROOT(vfsp, &root_vp))
301 		return (ENOENT);
302 
303 	VN_HOLD(vp);
304 
305 	/* NULL is passed in as we want to start at "/" */
306 	err = vnodetopath(NULL, root_vp, buf, buflen, sr->user_cr);
307 
308 	VN_RELE(vp);
309 	VN_RELE(root_vp);
310 	return (err);
311 }
312 
313 static uint32_t
314 smb_vss_encode_gmttokens(smb_request_t *sr, smb_xa_t *xa,
315     int32_t count, smb_dr_return_gmttokens_t *snap_data)
316 {
317 	uint32_t i;
318 	uint32_t returned_count;
319 	uint32_t num_gmttokens;
320 	char **gmttokens;
321 	uint32_t status = NT_STATUS_SUCCESS;
322 	uint32_t data_size;
323 
324 	returned_count = snap_data->rg_count;
325 	num_gmttokens = snap_data->rg_gmttokens.rg_gmttokens_len;
326 	gmttokens = snap_data->rg_gmttokens.rg_gmttokens_val;
327 
328 	if (returned_count > count)
329 		status = NT_STATUS_BUFFER_TOO_SMALL;
330 
331 	data_size = returned_count * SMB_VSS_GMT_NET_SIZE(sr) +
332 	    smb_ascii_or_unicode_null_len(sr);
333 
334 	if (smb_mbc_encodef(&xa->rep_data_mb, "lll", returned_count,
335 	    num_gmttokens, data_size) != 0)
336 		return (NT_STATUS_INVALID_PARAMETER);
337 
338 	if (status == NT_STATUS_SUCCESS) {
339 		for (i = 0; i < num_gmttokens; i++) {
340 			if (smb_mbc_encodef(&xa->rep_data_mb, "%u", sr,
341 			    *gmttokens) != 0)
342 				status = NT_STATUS_INVALID_PARAMETER;
343 			gmttokens++;
344 		}
345 	}
346 
347 	return (status);
348 }
349 
350 /* This removes the first @GMT from the path */
351 static void
352 smb_vss_remove_first_token_from_path(char *path)
353 {
354 	boolean_t found;
355 	char *src, *dest;
356 
357 	src = path;
358 	dest = path;
359 
360 	found = B_FALSE;
361 
362 	while (*src != '\0') {
363 		if (!found && smb_vss_is_gmttoken(src)) {
364 			src += SMB_VSS_GMT_SIZE - 1;
365 			if (*src == '/')
366 				src += 1;
367 			found = B_TRUE;
368 			continue;
369 		}
370 		*dest = *src;
371 		src++;
372 		dest++;
373 	}
374 	*dest = *src;
375 }
376