xref: /illumos-gate/usr/src/uts/common/fs/smbsrv/smb_locking_andx.c (revision e4d060fb4c00d44cd578713eb9a921f594b733b8)
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  * SMB: locking_andx
27  *
28  * SMB_COM_LOCKING_ANDX allows both locking and/or unlocking of file range(s).
29  *
30  *  Client Request                     Description
31  *  ================================== =================================
32  *
33  *  UCHAR WordCount;                   Count of parameter words = 8
34  *  UCHAR AndXCommand;                 Secondary (X) command;  0xFF = none
35  *  UCHAR AndXReserved;                Reserved (must be 0)
36  *  USHORT AndXOffset;                 Offset to next command WordCount
37  *  USHORT Fid;                        File handle
38  *  UCHAR LockType;                    See LockType table below
39  *  UCHAR OplockLevel;                 The new oplock level
40  *  ULONG Timeout;                     Milliseconds to wait for unlock
41  *  USHORT NumberOfUnlocks;            Num. unlock range structs following
42  *  USHORT NumberOfLocks;              Num. lock range structs following
43  *  USHORT ByteCount;                  Count of data bytes
44  *  LOCKING_ANDX_RANGE Unlocks[];      Unlock ranges
45  *  LOCKING_ANDX_RANGE Locks[];        Lock ranges
46  *
47  *  LockType Flag Name            Value Description
48  *  ============================  ===== ================================
49  *
50  *  LOCKING_ANDX_SHARED_LOCK      0x01  Read-only lock
51  *  LOCKING_ANDX_OPLOCK_RELEASE   0x02  Oplock break notification
52  *  LOCKING_ANDX_CHANGE_LOCKTYPE  0x04  Change lock type
53  *  LOCKING_ANDX_CANCEL_LOCK      0x08  Cancel outstanding request
54  *  LOCKING_ANDX_LARGE_FILES      0x10  Large file locking format
55  *
56  *  LOCKING_ANDX_RANGE Format
57  *  =====================================================================
58  *
59  *  USHORT Pid;                        PID of process "owning" lock
60  *  ULONG Offset;                      Offset to bytes to [un]lock
61  *  ULONG Length;                      Number of bytes to [un]lock
62  *
63  *  Large File LOCKING_ANDX_RANGE Format
64  *  =====================================================================
65  *
66  *  USHORT Pid;                        PID of process "owning" lock
67  *  USHORT Pad;                        Pad to DWORD align (mbz)
68  *  ULONG OffsetHigh;                  Offset to bytes to [un]lock
69  *                                      (high)
70  *  ULONG OffsetLow;                   Offset to bytes to [un]lock (low)
71  *  ULONG LengthHigh;                  Number of bytes to [un]lock
72  *                                      (high)
73  *  ULONG LengthLow;                   Number of bytes to [un]lock (low)
74  *
75  *  Server Response                    Description
76  *  ================================== =================================
77  *
78  *  UCHAR WordCount;                   Count of parameter words = 2
79  *  UCHAR AndXCommand;                 Secondary (X) command;  0xFF =
80  *                                      none
81  *  UCHAR AndXReserved;                Reserved (must be 0)
82  *  USHORT AndXOffset;                 Offset to next command WordCount
83  *  USHORT ByteCount;                  Count of data bytes = 0
84  *
85  * Locking is a simple mechanism for excluding other processes read/write
86  * access to regions of a file.  The locked regions can be anywhere in the
87  * logical file.  Locking beyond end-of-file is permitted.  Any process
88  * using the Fid specified in this request's Fid has access to the locked
89  * bytes, other processes will be denied the locking of the same bytes.
90  *
91  * The proper method for using locks is not to rely on being denied read or
92  * write access on any of the read/write protocols but rather to attempt
93  * the locking protocol and proceed with the read/write only if the locks
94  * succeeded.
95  *
96  * Locking a range of bytes will fail if any subranges or overlapping
97  * ranges are locked.  In other words, if any of the specified bytes are
98  * already locked, the lock will fail.
99  *
100  * If NumberOfUnlocks is non-zero, the Unlocks vector contains
101  * NumberOfUnlocks elements.  Each element requests that a lock at Offset
102  * of Length be released.  If NumberOfLocks is nonzero, the Locks vector
103  * contains NumberOfLocks elements.  Each element requests the acquisition
104  * of a lock at Offset of Length.
105  *
106  * Timeout is the maximum amount of time to wait for the byte range(s)
107  * specified to become unlocked.  A timeout value of 0 indicates that the
108  * server should fail immediately if any lock range specified is locked.  A
109  *
110  * timeout value of -1 indicates that the server should wait as long as it
111  * takes for each byte range specified to become unlocked so that it may be
112  * again locked by this protocol.  Any other value of smb_timeout specifies
113  * the maximum number of milliseconds to wait for all lock range(s)
114  * specified to become available.
115  *
116  * If any of the lock ranges timeout because of the area to be locked is
117  * already locked (or the lock fails), the other ranges in the protocol
118  * request which were successfully locked as a result of this protocol will
119  * be unlocked (either all requested ranges will be locked when this
120  * protocol returns to the client or none).
121  *
122  * If LockType has the LOCKING_ANDX_SHARED_LOCK flag set, the lock is
123  * specified as a shared lock.  Locks for both read and write (where
124  * LOCKING_ANDX_SHARED_LOCK is clear) should be prohibited, but other
125  * shared locks should be permitted.  If shared locks can not be supported
126  * by a server, the server should map the lock to a lock for both read and
127  * write.  Closing a file with locks still in force causes the locks to be
128  * released in no defined order.
129  *
130  * If LockType has the LOCKING_ANDX_LARGE_FILES flag set and if the
131  * negotiated protocol is NT LM 0.12 or later, then the Locks and Unlocks
132  * vectors are in the Large File LOCKING_ANDX_RANGE format.  This allows
133  * specification of 64 bit offsets for very large files.
134  *
135  * If the one and only member of the Locks vector has the
136  * LOCKING_ANDX_CANCEL_LOCK flag set in the LockType field, the client is
137  * requesting the server to cancel a previously requested, but not yet
138  * responded to, lock.
139  *
140  * If LockType has the LOCKING_ANDX_CHANGE_LOCKTYPE flag set, the client is
141  * requesting that the server atomically change the lock type from a shared
142  * lock to an exclusive lock or vice versa.  If the server can not do this
143  * in an atomic fashion, the server must reject this request.  NT and W95
144  * servers do not support this capability.
145  *
146  * Oplocks are described in the "Opportunistic Locks" section elsewhere in
147  * this document.  A client requests an oplock by setting the appropriate
148  * bit in the SMB_COM_OPEN_ANDX request when the file is being opened in a
149  * mode which is not exclusive.  The server responds by setting the
150  * appropriate bit in the response SMB indicating whether or not the oplock
151  * was granted.  By granting the oplock, the server tells the client the
152  * file is currently only being used by this one client process at the
153  * current time.  The client can therefore safely do read ahead and write
154  * behind as well as local caching of file locks knowing that the file will
155  * not be accessed/changed in any way by another process while the oplock
156  * is in effect.  The client will be notified when any other process
157  * attempts to open or modify the oplocked file.
158  *
159  * When another user attempts to open or otherwise modify the file which a
160  * client has oplocked, the server delays the second attempt and notifies
161  * the client via an SMB_LOCKING_ANDX SMB asynchronously sent from the
162  * server to the client.  This message has the LOCKING_ANDX_OPLOCK_RELEASE
163  * flag set indicating to the client that the oplock is being broken.
164  *
165  * OplockLevel indicates the type of oplock the client now owns. If
166  * OplockLevel is 0, the client possesses no oplocks on the file at all, if
167  * OplockLevel is 1 the client possesses a Level II oplock.  The client is
168  * expected to flush any dirty buffers to the server, submit any file locks
169  * and respond to the server with either an SMB_LOCKING_ANDX SMB having the
170  * LOCKING_ANDX_OPLOCK_RELEASE flag set, or with a file close if the file
171  * is no longer in use by the client.  If the client sends an
172  * SMB_LOCKING_ANDX SMB with the LOCKING_ANDX_OPLOCK_RELEASE flag set and
173  * NumberOfLocks is zero, the server does not send a response.  Since a
174  * close being sent to the server and break oplock notification from the
175  * server could cross on the wire, if the client gets an oplock
176  * notification on a file which it does not have open, that notification
177  * should be ignored.
178  *
179  * Due to timing, the client could get an "oplock broken" notification in a
180  * user's data buffer as a result of this notification crossing on the wire
181  * with a SMB_COM_READ_RAW request.  The client must detect this (use
182  * length of msg, "FFSMB", MID of -1 and Command of SMB_COM_LOCKING_ANDX)
183  * and honor the "oplock broken" notification as usual.  The server must
184  * also note on receipt of an SMB_COM_READ_RAW request that there is an
185  * outstanding (unanswered) "oplock broken" notification to the client and
186  * return a zero length response denoting failure of the read raw request.
187  * The client should (after responding to the "oplock broken"
188  * notification), use a standard read protocol to redo the read request.
189  * This allows a file to actually contain data matching an "oplock broken"
190  * notification and still be read correctly.
191  *
192  * The entire message sent and received including the optional second
193  * protocol must fit in the negotiated maximum transfer size.  The
194  * following are the only valid SMB commands for AndXCommand for
195  * SMB_COM_LOCKING_ANDX:
196  *
197  *     SMB_COM_READ       SMB_COM_READ_ANDX
198  *     SMB_COM_WRITE      SMB_COM_WRITE_ANDX
199  *     SMB_COM_FLUSH
200  *
201  * 4.2.6.1   Errors
202  *
203  * ERRDOS/ERRbadfile
204  * ERRDOS/ERRbadfid
205  * ERRDOS/ERRlock
206  * ERRDOS/ERRinvdevice
207  * ERRSRV/ERRinvid
208  * ERRSRV/ERRbaduid
209  */
210 
211 #include <smbsrv/smb_kproto.h>
212 
213 smb_sdrc_t
214 smb_pre_locking_andx(smb_request_t *sr)
215 {
216 	DTRACE_SMB_1(op__LockingX__start, smb_request_t *, sr);
217 	return (SDRC_SUCCESS);
218 }
219 
220 void
221 smb_post_locking_andx(smb_request_t *sr)
222 {
223 	DTRACE_SMB_1(op__LockingX__done, smb_request_t *, sr);
224 }
225 
226 smb_sdrc_t
227 smb_com_locking_andx(smb_request_t *sr)
228 {
229 	unsigned short	i;
230 	unsigned char	lock_type;	/* See lock_type table above */
231 	unsigned char	oplock_level;	/* The new oplock level */
232 	uint32_t	timeout;	/* Milliseconds to wait for lock */
233 	unsigned short	unlock_num;	/* # unlock range structs */
234 	unsigned short	lock_num;	/* # lock range structs */
235 	unsigned short	pid;		/* Process Id of owner */
236 	uint32_t	offset32, length32;
237 	uint64_t	offset64;
238 	uint64_t	length64;
239 	DWORD		result;
240 	int 		rc;
241 	uint32_t	ltype;
242 
243 	rc = smbsr_decode_vwv(sr, "4.wbblww", &sr->smb_fid, &lock_type,
244 	    &oplock_level, &timeout, &unlock_num, &lock_num);
245 	if (rc != 0)
246 		return (SDRC_ERROR);
247 
248 	smbsr_lookup_file(sr);
249 	if (sr->fid_ofile == NULL) {
250 		smbsr_error(sr, NT_STATUS_INVALID_HANDLE, ERRDOS, ERRbadfid);
251 		return (SDRC_ERROR);
252 	}
253 
254 	if (lock_type & LOCKING_ANDX_SHARED_LOCK)
255 		ltype = SMB_LOCK_TYPE_READONLY;
256 	else
257 		ltype = SMB_LOCK_TYPE_READWRITE;
258 
259 	pid = sr->smb_pid;	/* Save the original pid */
260 
261 	if (lock_type & LOCKING_ANDX_OPLOCK_RELEASE) {
262 		smb_oplock_release(sr->fid_ofile->f_node, sr->fid_ofile);
263 		/*
264 		 * According to the protocol:
265 		 *
266 		 * If the client sends an SMB_LOCKING_ANDX request with the
267 		 * LOCKING_ANDX_OPLOCK_RELEASE flag set
268 		 * and NumberOfLocks is zero,
269 		 * the server does not send a response.
270 		 *
271 		 * I'm not sure if it's going to break anything if I change
272 		 * it according to the protocol. So, I leave it unchanged
273 		 * for now.
274 		 */
275 		if (unlock_num == 0 && lock_num == 0)
276 			return (SDRC_NO_REPLY);
277 	}
278 
279 	/*
280 	 * No support for changing locktype (although we could probably
281 	 * implement this)
282 	 */
283 	if (lock_type & LOCKING_ANDX_CHANGE_LOCK_TYPE) {
284 		smbsr_error(sr, 0, ERRDOS, ERRnoatomiclocks);
285 		return (SDRC_ERROR);
286 	}
287 
288 	/*
289 	 * No support for cancel lock (smbtorture expects this)
290 	 */
291 	if (lock_type & LOCKING_ANDX_CANCEL_LOCK) {
292 		smbsr_error(sr, NT_STATUS_INVALID_PARAMETER,
293 		    ERRDOS, ERROR_INVALID_PARAMETER);
294 		return (SDRC_ERROR);
295 	}
296 
297 	if (lock_type & LOCKING_ANDX_LARGE_FILES) {
298 		/*
299 		 * negotiated protocol should be NT LM 0.12 or later
300 		 */
301 		if (sr->session->dialect < NT_LM_0_12) {
302 			smbsr_error(sr, NT_STATUS_INVALID_PARAMETER,
303 			    ERRDOS, ERROR_INVALID_PARAMETER);
304 			return (SDRC_ERROR);
305 		}
306 
307 		for (i = 0; i < unlock_num; i++) {
308 			rc = smb_mbc_decodef(&sr->smb_data, "w2.QQ",
309 			    &sr->smb_pid, &offset64, &length64);
310 			if (rc) {
311 				/*
312 				 * This is the error returned by Windows 2000
313 				 * even when STATUS32 has been negotiated.
314 				 */
315 				smbsr_error(sr, 0, ERRSRV, ERRerror);
316 				return (SDRC_ERROR);
317 			}
318 
319 			result = smb_unlock_range(sr, sr->fid_ofile->f_node,
320 			    offset64, length64);
321 			if (result != NT_STATUS_SUCCESS) {
322 				smbsr_error(sr, NT_STATUS_RANGE_NOT_LOCKED,
323 				    ERRDOS, ERRnotlocked);
324 				return (SDRC_ERROR);
325 			}
326 		}
327 
328 		for (i = 0; i < lock_num; i++) {
329 			rc = smb_mbc_decodef(&sr->smb_data, "w2.QQ",
330 			    &sr->smb_pid, &offset64, &length64);
331 			if (rc) {
332 				smbsr_error(sr, 0, ERRSRV, ERRerror);
333 				return (SDRC_ERROR);
334 			}
335 
336 			result = smb_lock_range(sr, offset64, length64, timeout,
337 			    ltype);
338 			if (result != NT_STATUS_SUCCESS) {
339 				smb_lock_range_error(sr, result);
340 				return (SDRC_ERROR);
341 			}
342 		}
343 	} else {
344 		for (i = 0; i < unlock_num; i++) {
345 			rc = smb_mbc_decodef(&sr->smb_data, "wll", &sr->smb_pid,
346 			    &offset32, &length32);
347 			if (rc) {
348 				smbsr_error(sr, 0, ERRSRV, ERRerror);
349 				return (SDRC_ERROR);
350 			}
351 
352 			result = smb_unlock_range(sr, sr->fid_ofile->f_node,
353 			    (uint64_t)offset32, (uint64_t)length32);
354 			if (result != NT_STATUS_SUCCESS) {
355 				smbsr_error(sr, NT_STATUS_RANGE_NOT_LOCKED,
356 				    ERRDOS, ERRnotlocked);
357 				return (SDRC_ERROR);
358 			}
359 		}
360 
361 		for (i = 0; i < lock_num; i++) {
362 			rc = smb_mbc_decodef(&sr->smb_data, "wll", &sr->smb_pid,
363 			    &offset32, &length32);
364 			if (rc) {
365 				smbsr_error(sr, 0, ERRSRV, ERRerror);
366 				return (SDRC_ERROR);
367 			}
368 
369 			result = smb_lock_range(sr, (uint64_t)offset32,
370 			    (uint64_t)length32, timeout, ltype);
371 			if (result != NT_STATUS_SUCCESS) {
372 				smb_lock_range_error(sr, result);
373 				return (SDRC_ERROR);
374 			}
375 		}
376 	}
377 
378 	sr->smb_pid = pid;
379 	if (smbsr_encode_result(sr, 2, 0, "bb.ww", 2, sr->andx_com, 7, 0))
380 		return (SDRC_ERROR);
381 	return (SDRC_SUCCESS);
382 }
383