xref: /illumos-gate/usr/src/uts/common/fs/smbsrv/smb_locking_andx.c (revision 14b24e2b79293068c8e016a69ef1d872fb5e2fd5)
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) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
24  * Copyright 2014 Nexenta Systems, Inc.  All rights reserved.
25  */
26 
27 /*
28  * SMB: locking_andx
29  *
30  * SMB_COM_LOCKING_ANDX allows both locking and/or unlocking of file range(s).
31  *
32  *  Client Request                     Description
33  *  ================================== =================================
34  *
35  *  UCHAR WordCount;                   Count of parameter words = 8
36  *  UCHAR AndXCommand;                 Secondary (X) command;  0xFF = none
37  *  UCHAR AndXReserved;                Reserved (must be 0)
38  *  USHORT AndXOffset;                 Offset to next command WordCount
39  *  USHORT Fid;                        File handle
40  *  UCHAR LockType;                    See LockType table below
41  *  UCHAR OplockLevel;                 The new oplock level
42  *  ULONG Timeout;                     Milliseconds to wait for unlock
43  *  USHORT NumberOfUnlocks;            Num. unlock range structs following
44  *  USHORT NumberOfLocks;              Num. lock range structs following
45  *  USHORT ByteCount;                  Count of data bytes
46  *  LOCKING_ANDX_RANGE Unlocks[];      Unlock ranges
47  *  LOCKING_ANDX_RANGE Locks[];        Lock ranges
48  *
49  *  LockType Flag Name            Value Description
50  *  ============================  ===== ================================
51  *
52  *  LOCKING_ANDX_SHARED_LOCK      0x01  Read-only lock
53  *  LOCKING_ANDX_OPLOCK_RELEASE   0x02  Oplock break notification
54  *  LOCKING_ANDX_CHANGE_LOCKTYPE  0x04  Change lock type
55  *  LOCKING_ANDX_CANCEL_LOCK      0x08  Cancel outstanding request
56  *  LOCKING_ANDX_LARGE_FILES      0x10  Large file locking format
57  *
58  *  LOCKING_ANDX_RANGE Format
59  *  =====================================================================
60  *
61  *  USHORT Pid;                        PID of process "owning" lock
62  *  ULONG Offset;                      Offset to bytes to [un]lock
63  *  ULONG Length;                      Number of bytes to [un]lock
64  *
65  *  Large File LOCKING_ANDX_RANGE Format
66  *  =====================================================================
67  *
68  *  USHORT Pid;                        PID of process "owning" lock
69  *  USHORT Pad;                        Pad to DWORD align (mbz)
70  *  ULONG OffsetHigh;                  Offset to bytes to [un]lock
71  *                                      (high)
72  *  ULONG OffsetLow;                   Offset to bytes to [un]lock (low)
73  *  ULONG LengthHigh;                  Number of bytes to [un]lock
74  *                                      (high)
75  *  ULONG LengthLow;                   Number of bytes to [un]lock (low)
76  *
77  *  Server Response                    Description
78  *  ================================== =================================
79  *
80  *  UCHAR WordCount;                   Count of parameter words = 2
81  *  UCHAR AndXCommand;                 Secondary (X) command;  0xFF =
82  *                                      none
83  *  UCHAR AndXReserved;                Reserved (must be 0)
84  *  USHORT AndXOffset;                 Offset to next command WordCount
85  *  USHORT ByteCount;                  Count of data bytes = 0
86  *
87  * Locking is a simple mechanism for excluding other processes read/write
88  * access to regions of a file.  The locked regions can be anywhere in the
89  * logical file.  Locking beyond end-of-file is permitted.  Any process
90  * using the Fid specified in this request's Fid has access to the locked
91  * bytes, other processes will be denied the locking of the same bytes.
92  *
93  * The proper method for using locks is not to rely on being denied read or
94  * write access on any of the read/write protocols but rather to attempt
95  * the locking protocol and proceed with the read/write only if the locks
96  * succeeded.
97  *
98  * Locking a range of bytes will fail if any subranges or overlapping
99  * ranges are locked.  In other words, if any of the specified bytes are
100  * already locked, the lock will fail.
101  *
102  * If NumberOfUnlocks is non-zero, the Unlocks vector contains
103  * NumberOfUnlocks elements.  Each element requests that a lock at Offset
104  * of Length be released.  If NumberOfLocks is nonzero, the Locks vector
105  * contains NumberOfLocks elements.  Each element requests the acquisition
106  * of a lock at Offset of Length.
107  *
108  * Timeout is the maximum amount of time to wait for the byte range(s)
109  * specified to become unlocked.  A timeout value of 0 indicates that the
110  * server should fail immediately if any lock range specified is locked.  A
111  *
112  * timeout value of -1 indicates that the server should wait as long as it
113  * takes for each byte range specified to become unlocked so that it may be
114  * again locked by this protocol.  Any other value of smb_timeout specifies
115  * the maximum number of milliseconds to wait for all lock range(s)
116  * specified to become available.
117  *
118  * If any of the lock ranges timeout because of the area to be locked is
119  * already locked (or the lock fails), the other ranges in the protocol
120  * request which were successfully locked as a result of this protocol will
121  * be unlocked (either all requested ranges will be locked when this
122  * protocol returns to the client or none).
123  *
124  * If LockType has the LOCKING_ANDX_SHARED_LOCK flag set, the lock is
125  * specified as a shared lock.  Locks for both read and write (where
126  * LOCKING_ANDX_SHARED_LOCK is clear) should be prohibited, but other
127  * shared locks should be permitted.  If shared locks can not be supported
128  * by a server, the server should map the lock to a lock for both read and
129  * write.  Closing a file with locks still in force causes the locks to be
130  * released in no defined order.
131  *
132  * If LockType has the LOCKING_ANDX_LARGE_FILES flag set and if the
133  * negotiated protocol is NT LM 0.12 or later, then the Locks and Unlocks
134  * vectors are in the Large File LOCKING_ANDX_RANGE format.  This allows
135  * specification of 64 bit offsets for very large files.
136  *
137  * If the one and only member of the Locks vector has the
138  * LOCKING_ANDX_CANCEL_LOCK flag set in the LockType field, the client is
139  * requesting the server to cancel a previously requested, but not yet
140  * responded to, lock.
141  *
142  * If LockType has the LOCKING_ANDX_CHANGE_LOCKTYPE flag set, the client is
143  * requesting that the server atomically change the lock type from a shared
144  * lock to an exclusive lock or vice versa.  If the server can not do this
145  * in an atomic fashion, the server must reject this request.  NT and W95
146  * servers do not support this capability.
147  *
148  * Oplocks are described in the "Opportunistic Locks" section elsewhere in
149  * this document.  A client requests an oplock by setting the appropriate
150  * bit in the SMB_COM_OPEN_ANDX request when the file is being opened in a
151  * mode which is not exclusive.  The server responds by setting the
152  * appropriate bit in the response SMB indicating whether or not the oplock
153  * was granted.  By granting the oplock, the server tells the client the
154  * file is currently only being used by this one client process at the
155  * current time.  The client can therefore safely do read ahead and write
156  * behind as well as local caching of file locks knowing that the file will
157  * not be accessed/changed in any way by another process while the oplock
158  * is in effect.  The client will be notified when any other process
159  * attempts to open or modify the oplocked file.
160  *
161  * When another user attempts to open or otherwise modify the file which a
162  * client has oplocked, the server delays the second attempt and notifies
163  * the client via an SMB_LOCKING_ANDX SMB asynchronously sent from the
164  * server to the client.  This message has the LOCKING_ANDX_OPLOCK_RELEASE
165  * flag set indicating to the client that the oplock is being broken.
166  *
167  * OplockLevel indicates the type of oplock the client now owns. If
168  * OplockLevel is 0, the client possesses no oplocks on the file at all, if
169  * OplockLevel is 1 the client possesses a Level II oplock.  The client is
170  * expected to flush any dirty buffers to the server, submit any file locks
171  * and respond to the server with either an SMB_LOCKING_ANDX SMB having the
172  * LOCKING_ANDX_OPLOCK_RELEASE flag set, or with a file close if the file
173  * is no longer in use by the client.  If the client sends an
174  * SMB_LOCKING_ANDX SMB with the LOCKING_ANDX_OPLOCK_RELEASE flag set and
175  * NumberOfLocks is zero, the server does not send a response.  Since a
176  * close being sent to the server and break oplock notification from the
177  * server could cross on the wire, if the client gets an oplock
178  * notification on a file which it does not have open, that notification
179  * should be ignored.
180  *
181  * Due to timing, the client could get an "oplock broken" notification in a
182  * user's data buffer as a result of this notification crossing on the wire
183  * with a SMB_COM_READ_RAW request.  The client must detect this (use
184  * length of msg, "FFSMB", MID of -1 and Command of SMB_COM_LOCKING_ANDX)
185  * and honor the "oplock broken" notification as usual.  The server must
186  * also note on receipt of an SMB_COM_READ_RAW request that there is an
187  * outstanding (unanswered) "oplock broken" notification to the client and
188  * return a zero length response denoting failure of the read raw request.
189  * The client should (after responding to the "oplock broken"
190  * notification), use a standard read protocol to redo the read request.
191  * This allows a file to actually contain data matching an "oplock broken"
192  * notification and still be read correctly.
193  *
194  * The entire message sent and received including the optional second
195  * protocol must fit in the negotiated maximum transfer size.  The
196  * following are the only valid SMB commands for AndXCommand for
197  * SMB_COM_LOCKING_ANDX:
198  *
199  *     SMB_COM_READ       SMB_COM_READ_ANDX
200  *     SMB_COM_WRITE      SMB_COM_WRITE_ANDX
201  *     SMB_COM_FLUSH
202  *
203  * 4.2.6.1   Errors
204  *
205  * ERRDOS/ERRbadfile
206  * ERRDOS/ERRbadfid
207  * ERRDOS/ERRlock
208  * ERRDOS/ERRinvdevice
209  * ERRSRV/ERRinvid
210  * ERRSRV/ERRbaduid
211  */
212 
213 #include <smbsrv/smb_kproto.h>
214 
215 smb_sdrc_t
216 smb_pre_locking_andx(smb_request_t *sr)
217 {
218 	DTRACE_SMB_1(op__LockingX__start, smb_request_t *, sr);
219 	return (SDRC_SUCCESS);
220 }
221 
222 void
223 smb_post_locking_andx(smb_request_t *sr)
224 {
225 	DTRACE_SMB_1(op__LockingX__done, smb_request_t *, sr);
226 }
227 
228 smb_sdrc_t
229 smb_com_locking_andx(smb_request_t *sr)
230 {
231 	unsigned short	i;
232 	unsigned char	lock_type;	/* See lock_type table above */
233 	unsigned char	oplock_level;	/* The new oplock level */
234 	uint32_t	timeout;	/* Milliseconds to wait for lock */
235 	unsigned short	unlock_num;	/* # unlock range structs */
236 	unsigned short	lock_num;	/* # lock range structs */
237 	uint32_t	save_pid;	/* Process Id of owner */
238 	uint32_t	offset32, length32;
239 	uint64_t	offset64;
240 	uint64_t	length64;
241 	DWORD		result;
242 	int 		rc;
243 	uint32_t	ltype;
244 	smb_ofile_t	*ofile;
245 	uint16_t	tmp_pid;	/* locking uses 16-bit pids */
246 	uint8_t		brk;
247 
248 	rc = smbsr_decode_vwv(sr, "4.wbblww", &sr->smb_fid, &lock_type,
249 	    &oplock_level, &timeout, &unlock_num, &lock_num);
250 	if (rc != 0)
251 		return (SDRC_ERROR);
252 
253 	smbsr_lookup_file(sr);
254 	if (sr->fid_ofile == NULL) {
255 		smbsr_error(sr, NT_STATUS_INVALID_HANDLE, ERRDOS, ERRbadfid);
256 		return (SDRC_ERROR);
257 	}
258 	ofile = sr->fid_ofile;
259 	if (ofile->f_node == NULL) {
260 		smbsr_error(sr, NT_STATUS_INVALID_PARAMETER,
261 		    ERRDOS, ERROR_INVALID_PARAMETER);
262 		return (SDRC_ERROR);
263 	}
264 
265 	if (lock_type & LOCKING_ANDX_SHARED_LOCK)
266 		ltype = SMB_LOCK_TYPE_READONLY;
267 	else
268 		ltype = SMB_LOCK_TYPE_READWRITE;
269 
270 	save_pid = sr->smb_pid;	/* Save the original pid */
271 
272 	if (lock_type & LOCKING_ANDX_OPLOCK_RELEASE) {
273 		if (oplock_level == 0)
274 			brk = SMB_OPLOCK_BREAK_TO_NONE;
275 		else
276 			brk = SMB_OPLOCK_BREAK_TO_LEVEL_II;
277 		smb_oplock_ack(ofile->f_node, ofile, brk);
278 		if (unlock_num == 0 && lock_num == 0)
279 			return (SDRC_NO_REPLY);
280 	}
281 
282 	/*
283 	 * No support for changing locktype (although we could probably
284 	 * implement this)
285 	 */
286 	if (lock_type & LOCKING_ANDX_CHANGE_LOCK_TYPE) {
287 		smbsr_error(sr, 0, ERRDOS,
288 		    ERROR_ATOMIC_LOCKS_NOT_SUPPORTED);
289 		return (SDRC_ERROR);
290 	}
291 
292 	/*
293 	 * No support for cancel lock (smbtorture expects this)
294 	 */
295 	if (lock_type & LOCKING_ANDX_CANCEL_LOCK) {
296 		smbsr_error(sr, NT_STATUS_INVALID_PARAMETER,
297 		    ERRDOS, ERROR_INVALID_PARAMETER);
298 		return (SDRC_ERROR);
299 	}
300 
301 	if (lock_type & LOCKING_ANDX_LARGE_FILES) {
302 		/*
303 		 * negotiated protocol should be NT LM 0.12 or later
304 		 */
305 		if (sr->session->dialect < NT_LM_0_12) {
306 			smbsr_error(sr, NT_STATUS_INVALID_PARAMETER,
307 			    ERRDOS, ERROR_INVALID_PARAMETER);
308 			return (SDRC_ERROR);
309 		}
310 
311 		for (i = 0; i < unlock_num; i++) {
312 			rc = smb_mbc_decodef(&sr->smb_data, "w2.QQ",
313 			    &tmp_pid, &offset64, &length64);
314 			if (rc) {
315 				/*
316 				 * This is the error returned by Windows 2000
317 				 * even when STATUS32 has been negotiated.
318 				 */
319 				smbsr_error(sr, 0, ERRSRV, ERRerror);
320 				return (SDRC_ERROR);
321 			}
322 			sr->smb_pid = tmp_pid;	/* NB: 16-bit */
323 
324 			result = smb_unlock_range(sr, sr->fid_ofile->f_node,
325 			    offset64, length64);
326 			if (result != NT_STATUS_SUCCESS) {
327 				smbsr_error(sr, NT_STATUS_RANGE_NOT_LOCKED,
328 				    ERRDOS, ERROR_NOT_LOCKED);
329 				return (SDRC_ERROR);
330 			}
331 		}
332 
333 		for (i = 0; i < lock_num; i++) {
334 			rc = smb_mbc_decodef(&sr->smb_data, "w2.QQ",
335 			    &tmp_pid, &offset64, &length64);
336 			if (rc) {
337 				smbsr_error(sr, 0, ERRSRV, ERRerror);
338 				return (SDRC_ERROR);
339 			}
340 			sr->smb_pid = tmp_pid;	/* NB: 16-bit */
341 
342 			result = smb_lock_range(sr, offset64, length64, timeout,
343 			    ltype);
344 			if (result != NT_STATUS_SUCCESS) {
345 				smb_lock_range_error(sr, result);
346 				return (SDRC_ERROR);
347 			}
348 		}
349 	} else {
350 		for (i = 0; i < unlock_num; i++) {
351 			rc = smb_mbc_decodef(&sr->smb_data, "wll", &tmp_pid,
352 			    &offset32, &length32);
353 			if (rc) {
354 				smbsr_error(sr, 0, ERRSRV, ERRerror);
355 				return (SDRC_ERROR);
356 			}
357 			sr->smb_pid = tmp_pid;	/* NB: 16-bit */
358 
359 			result = smb_unlock_range(sr, sr->fid_ofile->f_node,
360 			    (uint64_t)offset32, (uint64_t)length32);
361 			if (result != NT_STATUS_SUCCESS) {
362 				smbsr_error(sr, NT_STATUS_RANGE_NOT_LOCKED,
363 				    ERRDOS, ERROR_NOT_LOCKED);
364 				return (SDRC_ERROR);
365 			}
366 		}
367 
368 		for (i = 0; i < lock_num; i++) {
369 			rc = smb_mbc_decodef(&sr->smb_data, "wll", &tmp_pid,
370 			    &offset32, &length32);
371 			if (rc) {
372 				smbsr_error(sr, 0, ERRSRV, ERRerror);
373 				return (SDRC_ERROR);
374 			}
375 			sr->smb_pid = tmp_pid;	/* NB: 16-bit */
376 
377 			result = smb_lock_range(sr, (uint64_t)offset32,
378 			    (uint64_t)length32, timeout, ltype);
379 			if (result != NT_STATUS_SUCCESS) {
380 				smb_lock_range_error(sr, result);
381 				return (SDRC_ERROR);
382 			}
383 		}
384 	}
385 
386 	sr->smb_pid = save_pid;
387 	if (smbsr_encode_result(sr, 2, 0, "bb.ww", 2, sr->andx_com, 7, 0))
388 		return (SDRC_ERROR);
389 	return (SDRC_SUCCESS);
390 }
391 
392 /*
393  * Compose an SMB1 Oplock Break Notification packet, including
394  * the SMB1 header and everything, in sr->reply.
395  * The caller will send it and free the request.
396  */
397 void
398 smb1_oplock_break_notification(smb_request_t *sr, uint8_t brk)
399 {
400 	smb_ofile_t *ofile = sr->fid_ofile;
401 	uint16_t fid;
402 	uint8_t lock_type;
403 	uint8_t oplock_level;
404 
405 	switch (brk) {
406 	default:
407 		ASSERT(0);
408 		/* FALLTHROUGH */
409 	case SMB_OPLOCK_BREAK_TO_NONE:
410 		oplock_level = 0;
411 		break;
412 	case SMB_OPLOCK_BREAK_TO_LEVEL_II:
413 		oplock_level = 1;
414 		break;
415 	}
416 
417 	sr->smb_com = SMB_COM_LOCKING_ANDX;
418 	sr->smb_tid = ofile->f_tree->t_tid;
419 	sr->smb_pid = 0xFFFF;
420 	sr->smb_uid = 0;
421 	sr->smb_mid = 0xFFFF;
422 	fid = ofile->f_fid;
423 	lock_type = LOCKING_ANDX_OPLOCK_RELEASE;
424 
425 	(void) smb_mbc_encodef(
426 	    &sr->reply, "Mb19.wwwwbb3.wbb10.",
427 	    /*  "\xffSMB"		   M */
428 	    sr->smb_com,		/* b */
429 	    /* status, flags, signature	 19. */
430 	    sr->smb_tid,		/* w */
431 	    sr->smb_pid,		/* w */
432 	    sr->smb_uid,		/* w */
433 	    sr->smb_mid,		/* w */
434 	    8,		/* word count	   b */
435 	    0xFF,	/* AndX cmd	   b */
436 	    /*  AndX reserved, offset	  3. */
437 	    fid,
438 	    lock_type,
439 	    oplock_level);
440 }
441