xref: /onnv-gate/usr/src/uts/common/fs/smbsrv/smb_write_raw.c (revision 7961:4b5e3051f38b)
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 2008 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 /*
27  * SMB: write_raw
28  * 5.27       WRITE_RAW: Write Raw Bytes
29  *
30  * The Write Block Raw protocol is used to maximize the performance of
31  * writing a large block of data from the client to the server.  The Write
32  * Block Raw command's scope includes files, Named Pipes, and spooled
33  * output (can be used in place COM_WRITE_PRINT_FILE ).
34  *
35  *  Client Request              Description
36  *  ==========================  =========================================
37  *
38  *  UCHAR WordCount;            Count of parameter words = 12
39  *  USHORT Fid;                 File handle
40  *  USHORT Count;               Total bytes, including this buffer
41  *  USHORT Reserved;
42  *  ULONG Offset;               Offset in file to begin write
43  *  ULONG Timeout;
44  *  USHORT WriteMode;           Write mode:
45  *                              bit 0 - complete write to disk and send
46  *                              final result response
47  *                              bit 1 - return Remaining (pipe/dev)
48  *                              (see WriteAndX for #defines)
49  *  ULONG Reserved2;
50  *  USHORT DataLength;          Number of data bytes this buffer
51  *  USHORT DataOffset;          Offset (from header start) to data
52  *  USHORT ByteCount;           Count of data bytes
53  *  UCHAR Pad[];                Pad to SHORT or LONG
54  *  UCHAR Data[];               Data (# = DataLength)
55  *
56  *  First Server Response          Description
57  *  ============================== =====================================
58  *
59  *  UCHAR WordCount;               Count of parameter words = 1
60  *  USHORT Remaining;              Bytes remaining to be read if pipe
61  *  USHORT ByteCount;              Count of data bytes = 0
62  *
63  *  Final Server Response              Description
64  *  ================================== =================================
65  *
66  *  UCHAR Command (in SMB header)      SMB_COM_WRITE_COMPLETE
67  *
68  *  UCHAR WordCount;                   Count of parameter words = 1
69  *  USHORT Count;                      Total number of bytes written
70  *  USHORT ByteCount;                  Count of data bytes = 0
71  *
72  * The first response format will be that of the final server response in
73  * the case where the server gets an error while writing the data sent
74  * along with the request.  Thus Count is the number of bytes which did get
75  * written any time an error is returned.  If an error occurs after the
76  * first response has been sent allowing the client to send the remaining
77  * data, the final response should not be sent unless write through is set.
78  * Rather the server should return this "write behind" error on the next
79  * access to the Fid.
80  *
81  * The client must guarantee that there is (and will be) no other request
82  * on the connection for the duration of this request.  The server will
83  * reserve enough resources to receive the data and respond with a response
84  * SMB as defined above.  The client then sends the raw data in one send.
85  * Thus the server is able to receive up to 65,535 bytes of data directly
86  * into the server buffer.  The amount of data transferred is expected to
87  * be larger than the negotiated buffer size for this protocol.
88  *
89  * The reason that no other requests can be active on the connection for
90  * the duration of the request is that if other receives are present on the
91  * connection, there is normally no way to guarantee that the data will be
92  * received into the correct server buffer, rather the data may fill one
93  * (or more) of the other buffers.  Also if the client is sending other
94  * requests on the connection, a request may land in the buffer that the
95  * server has allocated for the this SMB's data.
96  *
97  * Whether or not SMB_COM_WRITE_RAW is supported is returned in the
98  * response to SMB_COM_NEGOTIATE.  SMB_COM_WRITE_RAW is not supported for
99  * connectionless clients.
100  *
101  * When write through is not specified ((WriteMode & 01) == 0) this SMB is
102  * assumed to be a form of write behind.  The transport layer guarantees
103  * delivery of all secondary requests from the client.  Thus no "got the
104  * data you sent" SMB is needed.  If an error should occur at the server
105  * end, all bytes must be received and thrown away.  If an error occurs
106  * while writing data to disk such as disk full, the next access of the
107  * file handle (another write, close, read, etc.) will return the fact that
108  * the error occurred.
109  *
110  * If write through is specified ((WriteMode & 01) != 0), the server will
111  * receive the data, write it to disk and then send a final response
112  * indicating the result of the write.  The total number of bytes written
113  * is also returned in this response in the Count field.
114  *
115  * The flow for the SMB_COM_WRITE_RAW SMB is:
116  *
117  * client -----> SMB_COM_WRITE_RAW request (optional data) >-------> server
118  * client <------------------< OK send (more) data <---------------- server
119  * client  ----------------------> raw data >----------------------> server
120  * client  <---< data on disk or error (write through only) <------- server
121  *
122  * This protocol is set up such that the SMB_COM_WRITE_RAW request may also
123  * carry data.  This is an optimization in that up to the server's buffer
124  * size (MaxCount from SMB_COM_NEGOTIATE response), minus the size of the
125  * SMB_COM_WRITE_RAW SMB request, may be sent along with the request.  Thus
126  * if the server is busy and unable to support the raw write of the
127  * remaining data, the data sent along with the request has been delivered
128  * and need not be sent again.  The server will write any data sent in the
129  * request (and wait for it to be on the disk or device if write through is
130  * set), prior to sending the response.
131  *
132  * The specific responses error class ERRSRV, error codes ERRusempx and
133  * ERRusestd, indicate that the server is temporarily out of the resources
134  *
135  * needed to support the raw write of the remaining data, but that any data
136  * sent along with the request has been successfully written.  The client
137  * should then write the remaining data using a different type of SMB write
138  * request, or delay and retry using SMB_COM_WRITE_RAW.  If a write error
139  * occurs writing the initial data, it will be returned and the write raw
140  * request is implicitly denied.
141  *
142  * The return field Remaining is returned for named pipes only.  It is used
143  * to return the number of bytes currently available in the pipe.  This
144  * information can then be used by the client to know when a subsequent
145  * (non blocking) read of the pipe may return some data.  Of course when
146  * the read request is actually received by the server there may be more or
147  * less actual data in the pipe (more data has been written to the pipe /
148  * device or another reader drained it).  If the information is currently
149  * not available or the request is NOT for a pipe or the server does not
150  * support this feature, a -1 value should be returned.
151  *
152  * If the negotiated dialect is NT LM 0.12 or later, and the response to
153  * the SMB_COM_NEGOTIATE SMB has CAP_LARGE_FILES set in the Capabilities
154  * field, an additional request format is allowed which accommodates very
155  * large files having 64 bit offsets:
156  *
157  *  Client Request                     Description
158  *  ================================== =================================
159  *   UCHAR WordCount;                   Count of parameter words = 14
160  *   USHORT Fid;                       File handle
161  *   USHORT Count;                     Total bytes, including this
162  *                                      buffer
163  *   USHORT Reserved;
164  *   ULONG Offset;                     Offset in file to begin write
165  *   ULONG Timeout;
166  *   USHORT WriteMode;                 Write mode:
167  *                                      bit 0 - complete write to disk
168  *                                      and send final result response
169  *                                      bit 1 - return Remaining
170  *                                      (pipe/dev)
171  *   ULONG Reserved2;
172  *   USHORT DataLength;                Number of data bytes this buffer
173  *   USHORT DataOffset;                Offset (from header start) to
174  *                                      data
175  *   ULONG OffsetHigh;                 Upper 32 bits of offset
176  *   USHORT ByteCount;                  Count of data bytes
177  *   UCHAR Pad[];                       Pad to SHORT or LONG
178  *   UCHAR Data[];                     Data (# = DataLength)
179  *
180  * In this case the final offset in the file is formed by combining
181  * OffsetHigh and Offset, the resulting offset must not be negative.
182  */
183 
184 #include <sys/sdt.h>
185 #include <smbsrv/smb_incl.h>
186 #include <smbsrv/smb_fsops.h>
187 #include <smbsrv/mbuf.h>
188 #include <smbsrv/netbios.h>
189 
190 extern uint32_t smb_keep_alive;
191 
192 static int smb_write_raw_helper(smb_request_t *, struct uio *, int,
193     offset_t *, uint32_t *);
194 static int smb_transfer_write_raw_data(smb_request_t *, uint16_t);
195 
196 #define	WR_MODE_WR_THRU	1
197 
198 smb_sdrc_t
199 smb_pre_write_raw(smb_request_t *sr)
200 {
201 	int rc = 0;
202 
203 	DTRACE_SMB_2(op__WriteRaw__start, smb_request_t *, sr,
204 	    smb_rw_param_t *, sr->arg.rw);
205 
206 	return ((rc == 0) ? SDRC_SUCCESS : SDRC_ERROR);
207 }
208 
209 void
210 smb_post_write_raw(smb_request_t *sr)
211 {
212 	DTRACE_SMB_2(op__WriteRaw__done, smb_request_t *, sr,
213 	    smb_rw_param_t *, sr->arg.rw);
214 }
215 
216 smb_sdrc_t
217 smb_com_write_raw(struct smb_request *sr)
218 {
219 	int			rc = 0;
220 	int			session_send_rc = 0;
221 	unsigned short		addl_xfer_count;
222 	unsigned short		count;
223 	unsigned short		write_mode, data_offset, data_length;
224 	offset_t		off;
225 	uint32_t		off_low, off_high, timeout;
226 	uint32_t		lcount = 0;
227 	uint32_t		addl_lcount = 0;
228 	struct uio		uio;
229 	iovec_t			iovec;
230 	int			stability;
231 	struct mbuf_chain	reply;
232 	smb_node_t		*fnode;
233 	smb_error_t		err;
234 
235 	if (sr->session->s_state != SMB_SESSION_STATE_WRITE_RAW_ACTIVE)
236 		return (SDRC_DROP_VC);
237 
238 	if (sr->smb_wct == 12) {
239 		off_high = 0;
240 		rc = smbsr_decode_vwv(sr, "ww2.llw4.ww", &sr->smb_fid, &count,
241 		    &off_low, &timeout, &write_mode, &data_length,
242 		    &data_offset);
243 		data_offset -= 59;
244 	} else {
245 		rc = smbsr_decode_vwv(sr, "ww2.llw4.wwl", &sr->smb_fid, &count,
246 		    &off_low, &timeout, &write_mode, &data_length,
247 		    &data_offset, &off_high);
248 		data_offset -= 63;
249 	}
250 
251 	if (rc != 0)
252 		return (SDRC_ERROR);
253 
254 	off = ((offset_t)off_high << 32) | off_low;
255 	addl_xfer_count = count - data_length;
256 
257 	sr->fid_ofile = smb_ofile_lookup_by_fid(sr->tid_tree, sr->smb_fid);
258 	if (sr->fid_ofile == NULL) {
259 		smbsr_error(sr, NT_STATUS_INVALID_HANDLE, ERRDOS, ERRbadfid);
260 		return (SDRC_ERROR);
261 	}
262 
263 	sr->user_cr = smb_ofile_getcred(sr->fid_ofile);
264 
265 	fnode = sr->fid_ofile->f_node;
266 	stability = ((write_mode & WR_MODE_WR_THRU) ||
267 	    (fnode->flags & NODE_FLAGS_WRITE_THROUGH)) ? FSYNC : 0;
268 
269 	if (STYPE_ISDSK(sr->tid_tree->t_res_type)) {
270 		/*
271 		 * See comments in smb_write.c
272 		 */
273 		if (fnode->attr.sa_vattr.va_type != VDIR) {
274 			rc = smb_lock_range_access(sr, fnode, off,
275 			    count, B_TRUE);
276 			if (rc != NT_STATUS_SUCCESS) {
277 				smbsr_error(sr, rc, ERRSRV, ERRaccess);
278 				return (SDRC_ERROR);
279 			}
280 		}
281 	}
282 
283 	/*
284 	 * Make sure any raw write data that is supposed to be
285 	 * contained in this SMB is actually present.
286 	 */
287 	if (sr->smb_data.chain_offset + data_offset + data_length >
288 	    sr->smb_data.max_bytes) {
289 		/* Error handling code will wake up the session daemon */
290 		return (SDRC_ERROR);
291 	}
292 
293 	/*
294 	 * Init uio (resid will get filled in later)
295 	 */
296 	uio.uio_iov = &iovec;
297 	uio.uio_iovcnt = 1;
298 	uio.uio_segflg = UIO_SYSSPACE;
299 	uio.uio_loffset = off;
300 
301 	/*
302 	 * Send response if there is additional data to transfer.  This
303 	 * will prompt the client to send the remaining data.
304 	 */
305 	if (addl_xfer_count != 0) {
306 		MBC_INIT(&reply, MLEN);
307 		(void) smb_mbc_encodef(&reply, SMB_HEADER_ED_FMT "bww",
308 		    sr->first_smb_com,
309 		    sr->smb_rcls,
310 		    sr->smb_reh,
311 		    sr->smb_err,
312 		    sr->smb_flg | SMB_FLAGS_REPLY,
313 		    sr->smb_flg2,
314 		    sr->smb_pid_high,
315 		    sr->smb_sig,
316 		    sr->smb_tid,
317 		    sr->smb_pid,
318 		    sr->smb_uid,
319 		    sr->smb_mid, 1, -1, 0);
320 
321 		if (sr->session->signing.flags & SMB_SIGNING_ENABLED)
322 			smb_sign_reply(sr, &reply);
323 
324 		session_send_rc = smb_session_send(sr->session, 0, &reply);
325 
326 		/*
327 		 * If the session response failed we're not going to
328 		 * return an error just yet -- we can still write the
329 		 * data we received along with the SMB even if the
330 		 * response failed.  If it failed, we need to force the
331 		 * stability level to "write-through".
332 		 */
333 		stability = (session_send_rc == 0) ? stability : FSYNC;
334 	}
335 
336 	/*
337 	 * While the response is in flight (and the data begins to arrive)
338 	 * write out the first data segment.  Start by setting up the
339 	 * iovec list for the first transfer.
340 	 */
341 	iovec.iov_base = sr->smb_data.chain->m_data +
342 	    sr->smb_data.chain_offset + data_offset;
343 	iovec.iov_len = data_length;
344 	uio.uio_resid = data_length;
345 
346 	/*
347 	 * smb_write_raw_helper will call smb_opipe_write or
348 	 * smb_fsop_write as appropriate, handle the NODE_FLAGS_SET_SIZE
349 	 * flag (if set) and update the other f_node fields.  It's possible
350 	 * that data_length may be 0 for this transfer but we still want
351 	 * process it since it will update the file state (seek position,
352 	 * file size (possibly), etc).
353 	 */
354 	rc = smb_write_raw_helper(sr, &uio, stability, &off, &lcount);
355 
356 	/*
357 	 * If our initial session response failed then we're done.  Return
358 	 * failure.  The client will know we wrote some of the data because
359 	 * of the transfer count (count - lcount) in the response.
360 	 */
361 	if (session_send_rc != 0) {
362 		sr->smb_rcls = ERRSRV;
363 		sr->smb_err  = ERRusestd;
364 		goto write_raw_transfer_failed;
365 	}
366 
367 	/*
368 	 * If we have more data to read then go get it
369 	 */
370 	if (addl_xfer_count) {
371 		/*
372 		 * This is the only place where a worker thread should
373 		 * directly read from the session socket.  If the data
374 		 * is read successfully then the buffer (sr->sr_raw_data_buf)
375 		 * will need to be freed after the data is written.
376 		 */
377 		if (smb_transfer_write_raw_data(sr, addl_xfer_count) != 0) {
378 			/*
379 			 * Raw data transfer failed
380 			 */
381 			goto write_raw_transfer_failed;
382 		}
383 
384 		/*
385 		 * Fill in next iov entry
386 		 */
387 		iovec.iov_base = sr->sr_raw_data_buf;
388 		iovec.iov_len = addl_xfer_count;
389 		uio.uio_resid = addl_xfer_count;
390 	}
391 
392 	/*
393 	 * Wake up session daemon since we now have all of our data and
394 	 * it's safe for the session daemon to resume processing SMB's.
395 	 */
396 	sr->session->s_write_raw_status = 0;
397 	sr->session->s_state = SMB_SESSION_STATE_NEGOTIATED;
398 
399 	/*
400 	 * If we didn't write all the data from the first segment then
401 	 * there's not much point in continuing (we still wanted to
402 	 * read any additional data above since we don't necessarily
403 	 * want to drop the connection and we need to read through
404 	 * to the next SMB).
405 	 */
406 	if ((rc != 0) || (lcount != data_length)) {
407 		goto notify_write_raw_complete;
408 	}
409 
410 	/*
411 	 * Write any additional data
412 	 */
413 	if (addl_xfer_count) {
414 		rc = smb_write_raw_helper(sr, &uio, stability, &off,
415 		    &addl_lcount);
416 	}
417 
418 	/*
419 	 * If we were called in "Write-behind" mode ((write_mode & 1) == 0)
420 	 * and the transfer was successful then we don't need to send
421 	 * any further response.  If we were called in "Write-Through" mode
422 	 * ((write_mode & 1) == 1) or if the transfer failed we need to
423 	 * send a completion notification.  The "count" value will indicate
424 	 * whether the transfer was successful.
425 	 */
426 	if ((rc != 0) || (write_mode & WR_MODE_WR_THRU) ||
427 	    (lcount + addl_lcount != count)) {
428 		goto notify_write_raw_complete;
429 	}
430 
431 	/*
432 	 * Free raw write buffer (allocated in smb_transfer_write_raw_data)
433 	 */
434 	kmem_free(sr->sr_raw_data_buf, sr->sr_raw_data_length);
435 
436 	(void) smb_session_send(sr->session, SESSION_KEEP_ALIVE, NULL);
437 	return (SDRC_NO_REPLY);
438 
439 write_raw_transfer_failed:
440 	/*
441 	 * Raw data transfer failed, wake up session
442 	 * daemon
443 	 */
444 	sr->session->s_write_raw_status = 20;
445 	sr->session->s_state = SMB_SESSION_STATE_NEGOTIATED;
446 
447 notify_write_raw_complete:
448 	/*
449 	 * If we had an error fill in the appropriate error code
450 	 */
451 	if (rc != 0) {
452 		smbsr_map_errno(rc, &err);
453 		smbsr_set_error(sr, &err);
454 	}
455 
456 	/*
457 	 * Free raw write buffer if present (from smb_transfer_write_raw_data)
458 	 */
459 	if (sr->sr_raw_data_buf != NULL) {
460 		kmem_free(sr->sr_raw_data_buf, sr->sr_raw_data_length);
461 	}
462 	/* Write complete notification */
463 	sr->first_smb_com = SMB_COM_WRITE_COMPLETE;
464 	rc = smbsr_encode_result(sr, 1, 0, "bww", 1,
465 	    count - (lcount + addl_lcount), 0);
466 	return ((rc == 0) ? SDRC_SUCCESS : SDRC_ERROR);
467 }
468 
469 
470 
471 /*
472  * smb_write_raw_helper
473  *
474  * This function will call smb_opipe_write or smb_fsop_write as appropriate,
475  * handle the NODE_FLAGS_SET_SIZE flag (if set) and update the other f_node
476  * fields.  It's possible that data_length may be 0 for this transfer but
477  * we still want process it since it will update the file state (seek
478  * position, file size (possibly), etc).
479  *
480  * Returns 0 for success, non-zero for failure
481  */
482 static int
483 smb_write_raw_helper(struct smb_request *sr, struct uio *uiop,
484     int stability, offset_t *offp, uint32_t *lcountp)
485 {
486 	smb_node_t *fnode;
487 	int rc = 0;
488 
489 	if (STYPE_ISIPC(sr->tid_tree->t_res_type)) {
490 		*lcountp = uiop->uio_resid;
491 
492 		if ((rc = smb_opipe_write(sr, uiop)) != 0)
493 			*lcountp = 0;
494 	} else {
495 		fnode = sr->fid_ofile->f_node;
496 		rc = smb_fsop_write(sr, sr->user_cr, fnode,
497 		    uiop, lcountp, &fnode->attr, stability);
498 
499 		if (rc == 0) {
500 
501 			fnode->flags |= NODE_FLAGS_SYNCATIME;
502 
503 			if (fnode->flags & NODE_FLAGS_SET_SIZE) {
504 				if ((*offp + *lcountp) >= fnode->n_size) {
505 					fnode->flags &= ~NODE_FLAGS_SET_SIZE;
506 					fnode->n_size = *offp + *lcountp;
507 				}
508 			}
509 		}
510 	}
511 
512 	*offp += *lcountp;
513 	mutex_enter(&sr->fid_ofile->f_mutex);
514 	sr->fid_ofile->f_seek_pos = *offp;
515 	mutex_exit(&sr->fid_ofile->f_mutex);
516 
517 	return (rc);
518 }
519 
520 
521 /*
522  * smb_handle_write_raw
523  *
524  * Called from smb_session_daemon() when the SMB command is SMB_COM_WRITE_RAW.
525  * Dispatches the command to the worker thread and waits until the worker
526  * has completed processing the command.
527  *
528  * Returns 0 for success, non-zero for failure
529  */
530 int
531 smb_handle_write_raw(smb_session_t *session, smb_request_t *sr)
532 {
533 	int	drop_reason = 0;
534 
535 	/*
536 	 * Set flag to indicate that we are waiting for raw data.  The
537 	 * worker thread will actually retrieve the raw data directly
538 	 * from the socket.  This should be the only case when a worker
539 	 * thread reads from the session socket.  When the data is read
540 	 * the worker will clear the flag.
541 	 */
542 	smb_rwx_rwenter(&session->s_lock, RW_WRITER);
543 	switch (session->s_state) {
544 	case SMB_SESSION_STATE_NEGOTIATED:
545 	case SMB_SESSION_STATE_OPLOCK_BREAKING:
546 		session->s_state = SMB_SESSION_STATE_WRITE_RAW_ACTIVE;
547 		smb_rwx_rwexit(&session->s_lock);
548 		sr->sr_state = SMB_REQ_STATE_SUBMITTED;
549 		(void) taskq_dispatch(session->s_server->sv_thread_pool,
550 		    smb_session_worker, sr, TQ_SLEEP);
551 		smb_rwx_rwenter(&session->s_lock, RW_READER);
552 		while (session->s_state == SMB_SESSION_STATE_WRITE_RAW_ACTIVE) {
553 			(void) smb_rwx_rwwait(&session->s_lock, -1);
554 		}
555 		drop_reason = session->s_write_raw_status;
556 		break;
557 	default:
558 		drop_reason = 21;
559 		break;
560 	}
561 	smb_rwx_rwexit(&session->s_lock);
562 	return (drop_reason);
563 }
564 
565 /*
566  * smb_transfer_write_raw_data
567  *
568  * Handles the second transfer phase of SMB_COM_WRITE_RAW.  smb_com_write_raw()
569  * will process the parameters and data from the SMB and send the initial
570  * SMB response.  This function reads the remaining data from the socket
571  * as it arrives from the client.
572  *
573  * Clients may send KEEP_ALIVE messages (when using NBT) between the first
574  * and second parts of write raw requests.  The only session transport
575  * types accepted here are SESSION_MESSAGE or SESSION_KEEP_ALIVE.
576  *
577  * Returns 0 for success, non-zero for failure
578  */
579 int
580 smb_transfer_write_raw_data(smb_request_t *sr, uint16_t addl_xfer_count)
581 {
582 	smb_session_t *session = sr->session;
583 	smb_xprt_t hdr;
584 	uint8_t *data_buf;
585 
586 	do {
587 		if (smb_session_xprt_gethdr(session, &hdr) != 0)
588 			return (-1);
589 
590 		if ((hdr.xh_type == SESSION_MESSAGE) ||
591 		    (hdr.xh_type == SESSION_KEEP_ALIVE)) {
592 			session->keep_alive = smb_keep_alive;
593 		} else {
594 			return (-1);
595 		}
596 	} while (hdr.xh_type == SESSION_KEEP_ALIVE);
597 
598 	if (hdr.xh_length < addl_xfer_count) {
599 		/*
600 		 * Less data than we were expecting.
601 		 */
602 		return (-1);
603 	}
604 
605 	data_buf = kmem_alloc(hdr.xh_length, KM_SLEEP);
606 
607 	if (smb_sorecv(session->sock, data_buf, hdr.xh_length) != 0) {
608 		kmem_free(data_buf, hdr.xh_length);
609 		sr->sr_raw_data_buf = NULL;
610 		sr->sr_raw_data_length = 0;
611 		return (-1);
612 	}
613 
614 	sr->sr_raw_data_buf = data_buf;
615 	sr->sr_raw_data_length = hdr.xh_length;
616 	return (0);
617 }
618