summaryrefslogtreecommitdiff
path: root/fs/smbfs/request.c
blob: 2d85dd7415bb2a487d35f6ddc96fb52e653bef1f (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
/*
 *  request.c
 *
 *  Copyright (C) 2001 by Urban Widmark
 *
 *  Please add a note about your changes to smbfs in the ChangeLog file.
 */

#include <linux/types.h>
#include <linux/fs.h>
#include <linux/slab.h>
#include <linux/net.h>

#include <linux/smb_fs.h>
#include <linux/smbno.h>
#include <linux/smb_mount.h>

#include "smb_debug.h"
#include "request.h"
#include "proto.h"

/* #define SMB_SLAB_DEBUG	(SLAB_RED_ZONE | SLAB_POISON) */
#define SMB_SLAB_DEBUG	0

#define ROUND_UP(x) (((x)+3) & ~3)

/* cache for request structures */
static kmem_cache_t *req_cachep;

static int smb_request_send_req(struct smb_request *req);

/*
  /proc/slabinfo:
  name, active, num, objsize, active_slabs, num_slaps, #pages
*/


int smb_init_request_cache(void)
{
	req_cachep = kmem_cache_create("smb_request",
				       sizeof(struct smb_request), 0,
				       SMB_SLAB_DEBUG | SLAB_HWCACHE_ALIGN,
				       NULL, NULL);
	if (req_cachep == NULL)
		return -ENOMEM;

	return 0;
}

void smb_destroy_request_cache(void)
{
	if (kmem_cache_destroy(req_cachep))
		printk(KERN_INFO "smb_destroy_request_cache: not all structures were freed\n");
}

/*
 * Allocate and initialise a request structure
 */
static struct smb_request *smb_do_alloc_request(struct smb_sb_info *server,
						int bufsize)
{
	struct smb_request *req;
	unsigned char *buf = NULL;

	req = kmem_cache_alloc(req_cachep, SLAB_KERNEL);
	VERBOSE("allocating request: %p\n", req);
	if (!req)
		goto out;

	if (bufsize > 0) {
		buf = smb_kmalloc(bufsize, GFP_NOFS);
		if (!buf) {
			kmem_cache_free(req_cachep, req);
			return NULL;
		}
	}

	memset(req, 0, sizeof(struct smb_request));
	req->rq_buffer = buf;
	req->rq_bufsize = bufsize;
	req->rq_server = server;
	init_waitqueue_head(&req->rq_wait);
	INIT_LIST_HEAD(&req->rq_queue);
	atomic_set(&req->rq_count, 1);

out:
	return req;
}

struct smb_request *smb_alloc_request(struct smb_sb_info *server, int bufsize)
{
	struct smb_request *req = NULL;

	for (;;) {
		atomic_inc(&server->nr_requests);
		if (atomic_read(&server->nr_requests) <= MAX_REQUEST_HARD) {
			req = smb_do_alloc_request(server, bufsize);
			if (req != NULL)
				break;
		}

#if 0
		/*
		 * Try to free up at least one request in order to stay
		 * below the hard limit
		 */
                if (nfs_try_to_free_pages(server))
			continue;

		if (signalled() && (server->flags & NFS_MOUNT_INTR))
			return ERR_PTR(-ERESTARTSYS);
		current->policy = SCHED_YIELD;
		schedule();
#else
		/* FIXME: we want something like nfs does above, but that
		   requires changes to all callers and can wait. */
		break;
#endif
	}
	return req;
}

static void smb_free_request(struct smb_request *req)
{
	atomic_dec(&req->rq_server->nr_requests);
	if (req->rq_buffer && !(req->rq_flags & SMB_REQ_STATIC))
		smb_kfree(req->rq_buffer);
	if (req->rq_trans2buffer)
		smb_kfree(req->rq_trans2buffer);
	kmem_cache_free(req_cachep, req);
}

/*
 * What prevents a rget to race with a rput? The count must never drop to zero
 * while it is in use. Only rput if it is ok that it is free'd.
 */
static void smb_rget(struct smb_request *req)
{
	atomic_inc(&req->rq_count);
}
void smb_rput(struct smb_request *req)
{
	if (atomic_dec_and_test(&req->rq_count)) {
		list_del_init(&req->rq_queue);
		smb_free_request(req);
	}
}

/* setup to receive the data part of the SMB */
static int smb_setup_bcc(struct smb_request *req)
{
	int result = 0;
	req->rq_rlen = smb_len(req->rq_header) + 4 - req->rq_bytes_recvd;

	if (req->rq_rlen > req->rq_bufsize) {
		PARANOIA("Packet too large %d > %d\n",
			 req->rq_rlen, req->rq_bufsize);
		return -ENOBUFS;
	}

	req->rq_iov[0].iov_base = req->rq_buffer;
	req->rq_iov[0].iov_len  = req->rq_rlen;
	req->rq_iovlen = 1;

	return result;
}

/*
 * Prepare a "normal" request structure.
 */
static int smb_setup_request(struct smb_request *req)
{
	int len = smb_len(req->rq_header) + 4;
	req->rq_slen = len;

	/* if we expect a data part in the reply we set the iov's to read it */
	if (req->rq_resp_bcc)
		req->rq_setup_read = smb_setup_bcc;

	/* This tries to support re-using the same request */
	req->rq_bytes_sent = 0;
	req->rq_rcls = 0;
	req->rq_err = 0;
	req->rq_errno = 0;
	req->rq_fragment = 0;
	if (req->rq_trans2buffer)
		smb_kfree(req->rq_trans2buffer);

	return 0;
}

/*
 * Prepare a transaction2 request structure
 */
static int smb_setup_trans2request(struct smb_request *req)
{
	struct smb_sb_info *server = req->rq_server;
	int mparam, mdata;
	static unsigned char padding[4];

	/* I know the following is very ugly, but I want to build the
	   smb packet as efficiently as possible. */

	const int smb_parameters = 15;
	const int header = SMB_HEADER_LEN + 2 * smb_parameters + 2;
	const int oparam = ROUND_UP(header + 3);
	const int odata  = ROUND_UP(oparam + req->rq_lparm);
	const int bcc = (req->rq_data ? odata + req->rq_ldata :
					oparam + req->rq_lparm) - header;

	if ((bcc + oparam) > server->opt.max_xmit)
		return -ENOMEM;
	smb_setup_header(req, SMBtrans2, smb_parameters, bcc);

	/*
	 * max parameters + max data + max setup == bufsize to make NT4 happy
	 * and not abort the transfer or split into multiple responses. It also
	 * makes smbfs happy as handling packets larger than the buffer size
	 * is extra work.
	 *
	 * OS/2 is probably going to hate me for this ...
	 */
	mparam = SMB_TRANS2_MAX_PARAM;
	mdata = req->rq_bufsize - mparam;

	mdata = server->opt.max_xmit - mparam - 100;
	if (mdata < 1024) {
		mdata = 1024;
		mparam = 20;
	}

#if 0
	/* NT/win2k has ~4k max_xmit, so with this we request more than it wants
	   to return as one SMB. Useful for testing the fragmented trans2
	   handling. */
	mdata = 8192;
#endif

	WSET(req->rq_header, smb_tpscnt, req->rq_lparm);
	WSET(req->rq_header, smb_tdscnt, req->rq_ldata);
	WSET(req->rq_header, smb_mprcnt, mparam);
	WSET(req->rq_header, smb_mdrcnt, mdata);
	WSET(req->rq_header, smb_msrcnt, 0);    /* max setup always 0 ? */
	WSET(req->rq_header, smb_flags, 0);
	DSET(req->rq_header, smb_timeout, 0);
	WSET(req->rq_header, smb_pscnt, req->rq_lparm);
	WSET(req->rq_header, smb_psoff, oparam - 4);
	WSET(req->rq_header, smb_dscnt, req->rq_ldata);
	WSET(req->rq_header, smb_dsoff, req->rq_data ? odata - 4 : 0);
	*(req->rq_header + smb_suwcnt) = 0x01;          /* setup count */
	*(req->rq_header + smb_suwcnt + 1) = 0x00;      /* reserved */
	WSET(req->rq_header, smb_setup0, req->rq_trans2_command);

	req->rq_iovlen = 2;
	req->rq_iov[0].iov_base = (void *) req->rq_header;
	req->rq_iov[0].iov_len = oparam;
	req->rq_iov[1].iov_base = (req->rq_parm==NULL) ? padding : req->rq_parm;
	req->rq_iov[1].iov_len = req->rq_lparm;
	req->rq_slen = oparam + req->rq_lparm;

	if (req->rq_data) {
		req->rq_iovlen += 2;
		req->rq_iov[2].iov_base = padding;
		req->rq_iov[2].iov_len = odata - oparam - req->rq_lparm;
		req->rq_iov[3].iov_base = req->rq_data;
		req->rq_iov[3].iov_len = req->rq_ldata;
		req->rq_slen = odata + req->rq_ldata;
	}

	/* always a data part for trans2 replies */
	req->rq_setup_read = smb_setup_bcc;

	return 0;
}

/*
 * Add a request and tell smbiod to process it
 */
int smb_add_request(struct smb_request *req)
{
	long timeleft;
	struct smb_sb_info *server = req->rq_server;
	int result = 0;

	smb_setup_request(req);
	if (req->rq_trans2_command) {
		if (req->rq_buffer == NULL) {
			PARANOIA("trans2 attempted without response buffer!\n");
			return -EIO;
		}
		result = smb_setup_trans2request(req);
	}
	if (result < 0)
		return result;

#ifdef SMB_DEBUG_PACKET_SIZE
	add_xmit_stats(req);
#endif

	/* add 'req' to the queue of requests */
	if (smb_lock_server_interruptible(server))
		return -EINTR;

	/*
	 * Try to send the request as the process. If that fails we queue the
	 * request and let smbiod send it later.
	 */

	/* FIXME: each server has a number on the maximum number of parallel
	   requests. 10, 50 or so. We should not allow more requests to be
	   active. */
	if (server->mid > 0xf000)
		server->mid = 0;
	req->rq_mid = server->mid++;
	WSET(req->rq_header, smb_mid, req->rq_mid);

	result = 0;
	if (server->state == CONN_VALID) {
		if (list_empty(&server->xmitq))
			result = smb_request_send_req(req);
		if (result < 0) {
			/* Connection lost? */
			server->conn_error = result;
			server->state = CONN_INVALID;
		}
	}
	if (result != 1)
		list_add_tail(&req->rq_queue, &server->xmitq);
	smb_rget(req);

	if (server->state != CONN_VALID)
		smbiod_retry(server);

	smb_unlock_server(server);

	smbiod_wake_up();

	timeleft = wait_event_interruptible_timeout(req->rq_wait,
				    req->rq_flags & SMB_REQ_RECEIVED, 30*HZ);
	if (!timeleft || signal_pending(current)) {
		/*
		 * On timeout or on interrupt we want to try and remove the
		 * request from the recvq/xmitq.
		 */
		smb_lock_server(server);
		if (!(req->rq_flags & SMB_REQ_RECEIVED)) {
			list_del_init(&req->rq_queue);
			smb_rput(req);
		}
		smb_unlock_server(server);
	}

	if (!timeleft) {
		PARANOIA("request [%p, mid=%d] timed out!\n",
			 req, req->rq_mid);
		VERBOSE("smb_com:  %02x\n", *(req->rq_header + smb_com));
		VERBOSE("smb_rcls: %02x\n", *(req->rq_header + smb_rcls));
		VERBOSE("smb_flg:  %02x\n", *(req->rq_header + smb_flg));
		VERBOSE("smb_tid:  %04x\n", WVAL(req->rq_header, smb_tid));
		VERBOSE("smb_pid:  %04x\n", WVAL(req->rq_header, smb_pid));
		VERBOSE("smb_uid:  %04x\n", WVAL(req->rq_header, smb_uid));
		VERBOSE("smb_mid:  %04x\n", WVAL(req->rq_header, smb_mid));
		VERBOSE("smb_wct:  %02x\n", *(req->rq_header + smb_wct));

		req->rq_rcls = ERRSRV;
		req->rq_err  = ERRtimeout;

		/* Just in case it was "stuck" */
		smbiod_wake_up();
	}
	VERBOSE("woke up, rcls=%d\n", req->rq_rcls);

	if (req->rq_rcls != 0)
		req->rq_errno = smb_errno(req);
	if (signal_pending(current))
		req->rq_errno = -ERESTARTSYS;
	return req->rq_errno;
}

/*
 * Send a request and place it on the recvq if successfully sent.
 * Must be called with the server lock held.
 */
static int smb_request_send_req(struct smb_request *req)
{
	struct smb_sb_info *server = req->rq_server;
	int result;

	if (req->rq_bytes_sent == 0) {
		WSET(req->rq_header, smb_tid, server->opt.tid);
		WSET(req->rq_header, smb_pid, 1);
		WSET(req->rq_header, smb_uid, server->opt.server_uid);
	}

	result = smb_send_request(req);
	if (result < 0 && result != -EAGAIN)
		goto out;

	result = 0;
	if (!(req->rq_flags & SMB_REQ_TRANSMITTED))
		goto out;

	list_del_init(&req->rq_queue);
	list_add_tail(&req->rq_queue, &server->recvq);
	result = 1;
out:
	return result;
}

/*
 * Sends one request for this server. (smbiod)
 * Must be called with the server lock held.
 * Returns: <0 on error
 *           0 if no request could be completely sent
 *           1 if all data for one request was sent
 */
int smb_request_send_server(struct smb_sb_info *server)
{
	struct list_head *head;
	struct smb_request *req;
	int result;

	if (server->state != CONN_VALID)
		return 0;

	/* dequeue first request, if any */
	req = NULL;
	head = server->xmitq.next;
	if (head != &server->xmitq) {
		req = list_entry(head, struct smb_request, rq_queue);
	}
	if (!req)
		return 0;

	result = smb_request_send_req(req);
	if (result < 0) {
		server->conn_error = result;
		list_del_init(&req->rq_queue);
		list_add(&req->rq_queue, &server->xmitq);
		result = -EIO;
		goto out;
	}

out:
	return result;
}

/*
 * Try to find a request matching this "mid". Typically the first entry will
 * be the matching one.
 */
static struct smb_request *find_request(struct smb_sb_info *server, int mid)
{
	struct list_head *tmp;
	struct smb_request *req = NULL;

	list_for_each(tmp, &server->recvq) {
		req = list_entry(tmp, struct smb_request, rq_queue);
		if (req->rq_mid == mid) {
			break;
		}
		req = NULL;
	}

	if (!req) {
		VERBOSE("received reply with mid %d but no request!\n",
			WVAL(server->header, smb_mid));
		server->rstate = SMB_RECV_DROP;
	}

	return req;
}

/*
 * Called when we have read the smb header and believe this is a response.
 */
static int smb_init_request(struct smb_sb_info *server, struct smb_request *req)
{
	int hdrlen, wct;

	memcpy(req->rq_header, server->header, SMB_HEADER_LEN);

	wct = *(req->rq_header + smb_wct);
	if (wct > 20) {	
		PARANOIA("wct too large, %d > 20\n", wct);
		server->rstate = SMB_RECV_DROP;
		return 0;
	}

	req->rq_resp_wct = wct;
	hdrlen = SMB_HEADER_LEN + wct*2 + 2;
	VERBOSE("header length: %d   smb_wct: %2d\n", hdrlen, wct);

	req->rq_bytes_recvd = SMB_HEADER_LEN;
	req->rq_rlen = hdrlen;
	req->rq_iov[0].iov_base = req->rq_header;
	req->rq_iov[0].iov_len  = hdrlen;
	req->rq_iovlen = 1;
	server->rstate = SMB_RECV_PARAM;

#ifdef SMB_DEBUG_PACKET_SIZE
	add_recv_stats(smb_len(server->header));
#endif
	return 0;
}

/*
 * Reads the SMB parameters
 */
static int smb_recv_param(struct smb_sb_info *server, struct smb_request *req)
{
	int result;

	result = smb_receive(server, req);
	if (result < 0)
		return result;
	if (req->rq_bytes_recvd < req->rq_rlen)
		return 0;

	VERBOSE("result: %d   smb_bcc:  %04x\n", result,
		WVAL(req->rq_header, SMB_HEADER_LEN +
		     (*(req->rq_header + smb_wct) * 2)));

	result = 0;
	req->rq_iov[0].iov_base = NULL;
	req->rq_rlen = 0;
	if (req->rq_callback)
		req->rq_callback(req);
	else if (req->rq_setup_read)
		result = req->rq_setup_read(req);
	if (result < 0) {
		server->rstate = SMB_RECV_DROP;
		return result;
	}

	server->rstate = req->rq_rlen > 0 ? SMB_RECV_DATA : SMB_RECV_END;

	req->rq_bytes_recvd = 0;	// recvd out of the iov

	VERBOSE("rlen: %d\n", req->rq_rlen);
	if (req->rq_rlen < 0) {
		PARANOIA("Parameters read beyond end of packet!\n");
		server->rstate = SMB_RECV_END;
		return -EIO;
	}
	return 0;
}

/*
 * Reads the SMB data
 */
static int smb_recv_data(struct smb_sb_info *server, struct smb_request *req)
{
	int result;

	result = smb_receive(server, req);
	if (result < 0)
		goto out;
	if (req->rq_bytes_recvd < req->rq_rlen)
		goto out;
	server->rstate = SMB_RECV_END;
out:
	VERBOSE("result: %d\n", result);
	return result;
}

/*
 * Receive a transaction2 response
 * Return: 0 if the response has been fully read
 *         1 if there are further "fragments" to read
 *        <0 if there is an error
 */
static int smb_recv_trans2(struct smb_sb_info *server, struct smb_request *req)
{
	unsigned char *inbuf;
	unsigned int parm_disp, parm_offset, parm_count, parm_tot;
	unsigned int data_disp, data_offset, data_count, data_tot;
	int hdrlen = SMB_HEADER_LEN + req->rq_resp_wct*2 - 2;

	VERBOSE("handling trans2\n");

	inbuf = req->rq_header;
	data_tot    = WVAL(inbuf, smb_tdrcnt);
	parm_tot    = WVAL(inbuf, smb_tprcnt);
	parm_disp   = WVAL(inbuf, smb_prdisp);
	parm_offset = WVAL(inbuf, smb_proff);
	parm_count  = WVAL(inbuf, smb_prcnt);
	data_disp   = WVAL(inbuf, smb_drdisp);
	data_offset = WVAL(inbuf, smb_droff);
	data_count  = WVAL(inbuf, smb_drcnt);

	/* Modify offset for the split header/buffer we use */
	if (data_count || data_offset) {
		if (unlikely(data_offset < hdrlen))
			goto out_bad_data;
		else
			data_offset -= hdrlen;
	}
	if (parm_count || parm_offset) {
		if (unlikely(parm_offset < hdrlen))
			goto out_bad_parm;
		else
			parm_offset -= hdrlen;
	}

	if (parm_count == parm_tot && data_count == data_tot) {
		/*
		 * This packet has all the trans2 data.
		 *
		 * We setup the request so that this will be the common
		 * case. It may be a server error to not return a
		 * response that fits.
		 */
		VERBOSE("single trans2 response  "
			"dcnt=%u, pcnt=%u, doff=%u, poff=%u\n",
			data_count, parm_count,
			data_offset, parm_offset);
		req->rq_ldata = data_count;
		req->rq_lparm = parm_count;
		req->rq_data = req->rq_buffer + data_offset;
		req->rq_parm = req->rq_buffer + parm_offset;
		if (unlikely(parm_offset + parm_count > req->rq_rlen))
			goto out_bad_parm;
		if (unlikely(data_offset + data_count > req->rq_rlen))
			goto out_bad_data;
		return 0;
	}

	VERBOSE("multi trans2 response  "
		"frag=%d, dcnt=%u, pcnt=%u, doff=%u, poff=%u\n",
		req->rq_fragment,
		data_count, parm_count,
		data_offset, parm_offset);

	if (!req->rq_fragment) {
		int buf_len;

		/* We got the first trans2 fragment */
		req->rq_fragment = 1;
		req->rq_total_data = data_tot;
		req->rq_total_parm = parm_tot;
		req->rq_ldata = 0;
		req->rq_lparm = 0;

		buf_len = data_tot + parm_tot;
		if (buf_len > SMB_MAX_PACKET_SIZE)
			goto out_too_long;

		req->rq_trans2bufsize = buf_len;
		req->rq_trans2buffer = smb_kmalloc(buf_len, GFP_NOFS);
		if (!req->rq_trans2buffer)
			goto out_no_mem;
		memset(req->rq_trans2buffer, 0, buf_len);

		req->rq_parm = req->rq_trans2buffer;
		req->rq_data = req->rq_trans2buffer + parm_tot;
	} else if (unlikely(req->rq_total_data < data_tot ||
			    req->rq_total_parm < parm_tot))
		goto out_data_grew;

	if (unlikely(parm_disp + parm_count > req->rq_total_parm ||
		     parm_offset + parm_count > req->rq_rlen))
		goto out_bad_parm;
	if (unlikely(data_disp + data_count > req->rq_total_data ||
		     data_offset + data_count > req->rq_rlen))
		goto out_bad_data;

	inbuf = req->rq_buffer;
	memcpy(req->rq_parm + parm_disp, inbuf + parm_offset, parm_count);
	memcpy(req->rq_data + data_disp, inbuf + data_offset, data_count);

	req->rq_ldata += data_count;
	req->rq_lparm += parm_count;

	/*
	 * Check whether we've received all of the data. Note that
	 * we use the packet totals -- total lengths might shrink!
	 */
	if (req->rq_ldata >= data_tot && req->rq_lparm >= parm_tot) {
		req->rq_ldata = data_tot;
		req->rq_lparm = parm_tot;
		return 0;
	}
	return 1;

out_too_long:
	printk(KERN_ERR "smb_trans2: data/param too long, data=%u, parm=%u\n",
		data_tot, parm_tot);
	goto out_EIO;
out_no_mem:
	printk(KERN_ERR "smb_trans2: couldn't allocate data area of %d bytes\n",
	       req->rq_trans2bufsize);
	req->rq_errno = -ENOMEM;
	goto out;
out_data_grew:
	printk(KERN_ERR "smb_trans2: data/params grew!\n");
	goto out_EIO;
out_bad_parm:
	printk(KERN_ERR "smb_trans2: invalid parms, disp=%u, cnt=%u, tot=%u, ofs=%u\n",
	       parm_disp, parm_count, parm_tot, parm_offset);
	goto out_EIO;
out_bad_data:
	printk(KERN_ERR "smb_trans2: invalid data, disp=%u, cnt=%u, tot=%u, ofs=%u\n",
	       data_disp, data_count, data_tot, data_offset);
out_EIO:
	req->rq_errno = -EIO;
out:
	return req->rq_errno;
}

/*
 * State machine for receiving responses. We handle the fact that we can't
 * read the full response in one try by having states telling us how much we
 * have read.
 *
 * Must be called with the server lock held (only called from smbiod).
 *
 * Return: <0 on error
 */
int smb_request_recv(struct smb_sb_info *server)
{
	struct smb_request *req = NULL;
	int result = 0;

	if (smb_recv_available(server) <= 0)
		return 0;

	VERBOSE("state: %d\n", server->rstate);
	switch (server->rstate) {
	case SMB_RECV_DROP:
		result = smb_receive_drop(server);
		if (result < 0)
			break;
		if (server->rstate == SMB_RECV_DROP)
			break;
		server->rstate = SMB_RECV_START;
		/* fallthrough */
	case SMB_RECV_START:
		server->smb_read = 0;
		server->rstate = SMB_RECV_HEADER;
		/* fallthrough */
	case SMB_RECV_HEADER:
		result = smb_receive_header(server);
		if (result < 0)
			break;
		if (server->rstate == SMB_RECV_HEADER)
			break;
		if (! (*(server->header + smb_flg) & SMB_FLAGS_REPLY) ) {
			server->rstate = SMB_RECV_REQUEST;
			break;
		}
		if (server->rstate != SMB_RECV_HCOMPLETE)
			break;
		/* fallthrough */
	case SMB_RECV_HCOMPLETE:
		req = find_request(server, WVAL(server->header, smb_mid));
		if (!req)
			break;
		smb_init_request(server, req);
		req->rq_rcls = *(req->rq_header + smb_rcls);
		req->rq_err  = WVAL(req->rq_header, smb_err);
		if (server->rstate != SMB_RECV_PARAM)
			break;
		/* fallthrough */
	case SMB_RECV_PARAM:
		if (!req)
			req = find_request(server,WVAL(server->header,smb_mid));
		if (!req)
			break;
		result = smb_recv_param(server, req);
		if (result < 0)
			break;
		if (server->rstate != SMB_RECV_DATA)
			break;
		/* fallthrough */
	case SMB_RECV_DATA:
		if (!req)
			req = find_request(server,WVAL(server->header,smb_mid));
		if (!req)
			break;
		result = smb_recv_data(server, req);
		if (result < 0)
			break;
		break;

		/* We should never be called with any of these states */
	case SMB_RECV_END:
	case SMB_RECV_REQUEST:
		server->rstate = SMB_RECV_END;
		break;
	}

	if (result < 0) {
		/* We saw an error */
		return result;
	}

	if (server->rstate != SMB_RECV_END)
		return 0;

	result = 0;
	if (req->rq_trans2_command && req->rq_rcls == SUCCESS)
		result = smb_recv_trans2(server, req);

	/*
	 * Response completely read. Drop any extra bytes sent by the server.
	 * (Yes, servers sometimes add extra bytes to responses)
	 */
	VERBOSE("smb_len: %d   smb_read: %d\n",
		server->smb_len, server->smb_read);
	if (server->smb_read < server->smb_len)
		smb_receive_drop(server);

	server->rstate = SMB_RECV_START;

	if (!result) {
		list_del_init(&req->rq_queue);
		req->rq_flags |= SMB_REQ_RECEIVED;
		smb_rput(req);
		wake_up_interruptible(&req->rq_wait);
	}
	return 0;
}