summaryrefslogtreecommitdiff
path: root/fs/ksmbd/smb_common.c
blob: b108b918ec8453676b8d03f5d509e583ebec44d1 (plain)
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
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *   Copyright (C) 2018 Samsung Electronics Co., Ltd.
 *   Copyright (C) 2018 Namjae Jeon <linkinjeon@kernel.org>
 */

#include "smb_common.h"
#include "server.h"
#include "misc.h"
#include "smbstatus.h"
#include "connection.h"
#include "ksmbd_work.h"
#include "mgmt/user_session.h"
#include "mgmt/user_config.h"
#include "mgmt/tree_connect.h"
#include "mgmt/share_config.h"

/*for shortname implementation */
static const char basechars[43] = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ_-!@#$%";
#define MANGLE_BASE (sizeof(basechars) / sizeof(char) - 1)
#define MAGIC_CHAR '~'
#define PERIOD '.'
#define mangle(V) ((char)(basechars[(V) % MANGLE_BASE]))
#define KSMBD_MIN_SUPPORTED_HEADER_SIZE	(sizeof(struct smb2_hdr))

struct smb_protocol {
	int		index;
	char		*name;
	char		*prot;
	__u16		prot_id;
};

static struct smb_protocol smb1_protos[] = {
	{
		SMB21_PROT,
		"\2SMB 2.1",
		"SMB2_10",
		SMB21_PROT_ID
	},
	{
		SMB2X_PROT,
		"\2SMB 2.???",
		"SMB2_22",
		SMB2X_PROT_ID
	},
};

static struct smb_protocol smb2_protos[] = {
	{
		SMB21_PROT,
		"\2SMB 2.1",
		"SMB2_10",
		SMB21_PROT_ID
	},
	{
		SMB30_PROT,
		"\2SMB 3.0",
		"SMB3_00",
		SMB30_PROT_ID
	},
	{
		SMB302_PROT,
		"\2SMB 3.02",
		"SMB3_02",
		SMB302_PROT_ID
	},
	{
		SMB311_PROT,
		"\2SMB 3.1.1",
		"SMB3_11",
		SMB311_PROT_ID
	},
};

unsigned int ksmbd_server_side_copy_max_chunk_count(void)
{
	return 256;
}

unsigned int ksmbd_server_side_copy_max_chunk_size(void)
{
	return (2U << 30) - 1;
}

unsigned int ksmbd_server_side_copy_max_total_size(void)
{
	return (2U << 30) - 1;
}

inline int ksmbd_min_protocol(void)
{
	return SMB2_PROT;
}

inline int ksmbd_max_protocol(void)
{
	return SMB311_PROT;
}

int ksmbd_lookup_protocol_idx(char *str)
{
	int offt = ARRAY_SIZE(smb1_protos) - 1;
	int len = strlen(str);

	while (offt >= 0) {
		if (!strncmp(str, smb1_protos[offt].prot, len)) {
			ksmbd_debug(SMB, "selected %s dialect idx = %d\n",
				    smb1_protos[offt].prot, offt);
			return smb1_protos[offt].index;
		}
		offt--;
	}

	offt = ARRAY_SIZE(smb2_protos) - 1;
	while (offt >= 0) {
		if (!strncmp(str, smb2_protos[offt].prot, len)) {
			ksmbd_debug(SMB, "selected %s dialect idx = %d\n",
				    smb2_protos[offt].prot, offt);
			return smb2_protos[offt].index;
		}
		offt--;
	}
	return -1;
}

/**
 * ksmbd_verify_smb_message() - check for valid smb2 request header
 * @work:	smb work
 *
 * check for valid smb signature and packet direction(request/response)
 *
 * Return:      0 on success, otherwise 1
 */
int ksmbd_verify_smb_message(struct ksmbd_work *work)
{
	struct smb2_hdr *smb2_hdr = work->request_buf;

	if (smb2_hdr->ProtocolId == SMB2_PROTO_NUMBER)
		return ksmbd_smb2_check_message(work);

	return 0;
}

/**
 * ksmbd_smb_request() - check for valid smb request type
 * @conn:	connection instance
 *
 * Return:      true on success, otherwise false
 */
bool ksmbd_smb_request(struct ksmbd_conn *conn)
{
	int type = *(char *)conn->request_buf;

	switch (type) {
	case RFC1002_SESSION_MESSAGE:
		/* Regular SMB request */
		return true;
	case RFC1002_SESSION_KEEP_ALIVE:
		ksmbd_debug(SMB, "RFC 1002 session keep alive\n");
		break;
	default:
		ksmbd_debug(SMB, "RFC 1002 unknown request type 0x%x\n", type);
	}

	return false;
}

static bool supported_protocol(int idx)
{
	if (idx == SMB2X_PROT &&
	    (server_conf.min_protocol >= SMB21_PROT ||
	     server_conf.max_protocol <= SMB311_PROT))
		return true;

	return (server_conf.min_protocol <= idx &&
		idx <= server_conf.max_protocol);
}

static char *next_dialect(char *dialect, int *next_off)
{
	dialect = dialect + *next_off;
	*next_off = strlen(dialect);
	return dialect;
}

static int ksmbd_lookup_dialect_by_name(char *cli_dialects, __le16 byte_count)
{
	int i, seq_num, bcount, next;
	char *dialect;

	for (i = ARRAY_SIZE(smb1_protos) - 1; i >= 0; i--) {
		seq_num = 0;
		next = 0;
		dialect = cli_dialects;
		bcount = le16_to_cpu(byte_count);
		do {
			dialect = next_dialect(dialect, &next);
			ksmbd_debug(SMB, "client requested dialect %s\n",
				    dialect);
			if (!strcmp(dialect, smb1_protos[i].name)) {
				if (supported_protocol(smb1_protos[i].index)) {
					ksmbd_debug(SMB,
						    "selected %s dialect\n",
						    smb1_protos[i].name);
					if (smb1_protos[i].index == SMB1_PROT)
						return seq_num;
					return smb1_protos[i].prot_id;
				}
			}
			seq_num++;
			bcount -= (++next);
		} while (bcount > 0);
	}

	return BAD_PROT_ID;
}

int ksmbd_lookup_dialect_by_id(__le16 *cli_dialects, __le16 dialects_count)
{
	int i;
	int count;

	for (i = ARRAY_SIZE(smb2_protos) - 1; i >= 0; i--) {
		count = le16_to_cpu(dialects_count);
		while (--count >= 0) {
			ksmbd_debug(SMB, "client requested dialect 0x%x\n",
				    le16_to_cpu(cli_dialects[count]));
			if (le16_to_cpu(cli_dialects[count]) !=
					smb2_protos[i].prot_id)
				continue;

			if (supported_protocol(smb2_protos[i].index)) {
				ksmbd_debug(SMB, "selected %s dialect\n",
					    smb2_protos[i].name);
				return smb2_protos[i].prot_id;
			}
		}
	}

	return BAD_PROT_ID;
}

static int ksmbd_negotiate_smb_dialect(void *buf)
{
	__le32 proto;

	proto = ((struct smb2_hdr *)buf)->ProtocolId;
	if (proto == SMB2_PROTO_NUMBER) {
		struct smb2_negotiate_req *req;

		req = (struct smb2_negotiate_req *)buf;
		return ksmbd_lookup_dialect_by_id(req->Dialects,
						  req->DialectCount);
	}

	proto = *(__le32 *)((struct smb_hdr *)buf)->Protocol;
	if (proto == SMB1_PROTO_NUMBER) {
		struct smb_negotiate_req *req;

		req = (struct smb_negotiate_req *)buf;
		return ksmbd_lookup_dialect_by_name(req->DialectsArray,
						    req->ByteCount);
	}

	return BAD_PROT_ID;
}

#define SMB_COM_NEGOTIATE	0x72
int ksmbd_init_smb_server(struct ksmbd_work *work)
{
	struct ksmbd_conn *conn = work->conn;

	if (conn->need_neg == false)
		return 0;

	init_smb3_11_server(conn);

	if (conn->ops->get_cmd_val(work) != SMB_COM_NEGOTIATE)
		conn->need_neg = false;
	return 0;
}

bool ksmbd_pdu_size_has_room(unsigned int pdu)
{
	return (pdu >= KSMBD_MIN_SUPPORTED_HEADER_SIZE - 4);
}

int ksmbd_populate_dot_dotdot_entries(struct ksmbd_work *work, int info_level,
				      struct ksmbd_file *dir,
				      struct ksmbd_dir_info *d_info,
				      char *search_pattern,
				      int (*fn)(struct ksmbd_conn *, int,
						struct ksmbd_dir_info *,
						struct user_namespace *,
						struct ksmbd_kstat *))
{
	int i, rc = 0;
	struct ksmbd_conn *conn = work->conn;
	struct user_namespace *user_ns = file_mnt_user_ns(dir->filp);

	for (i = 0; i < 2; i++) {
		struct kstat kstat;
		struct ksmbd_kstat ksmbd_kstat;

		if (!dir->dot_dotdot[i]) { /* fill dot entry info */
			if (i == 0) {
				d_info->name = ".";
				d_info->name_len = 1;
			} else {
				d_info->name = "..";
				d_info->name_len = 2;
			}

			if (!match_pattern(d_info->name, d_info->name_len,
					   search_pattern)) {
				dir->dot_dotdot[i] = 1;
				continue;
			}

			ksmbd_kstat.kstat = &kstat;
			ksmbd_vfs_fill_dentry_attrs(work,
						    user_ns,
						    dir->filp->f_path.dentry->d_parent,
						    &ksmbd_kstat);
			rc = fn(conn, info_level, d_info,
				user_ns, &ksmbd_kstat);
			if (rc)
				break;
			if (d_info->out_buf_len <= 0)
				break;

			dir->dot_dotdot[i] = 1;
			if (d_info->flags & SMB2_RETURN_SINGLE_ENTRY) {
				d_info->out_buf_len = 0;
				break;
			}
		}
	}

	return rc;
}

/**
 * ksmbd_extract_shortname() - get shortname from long filename
 * @conn:	connection instance
 * @longname:	source long filename
 * @shortname:	destination short filename
 *
 * Return:	shortname length or 0 when source long name is '.' or '..'
 * TODO: Though this function comforms the restriction of 8.3 Filename spec,
 * but the result is different with Windows 7's one. need to check.
 */
int ksmbd_extract_shortname(struct ksmbd_conn *conn, const char *longname,
			    char *shortname)
{
	const char *p;
	char base[9], extension[4];
	char out[13] = {0};
	int baselen = 0;
	int extlen = 0, len = 0;
	unsigned int csum = 0;
	const unsigned char *ptr;
	bool dot_present = true;

	p = longname;
	if ((*p == '.') || (!(strcmp(p, "..")))) {
		/*no mangling required */
		return 0;
	}

	p = strrchr(longname, '.');
	if (p == longname) { /*name starts with a dot*/
		strscpy(extension, "___", strlen("___"));
	} else {
		if (p) {
			p++;
			while (*p && extlen < 3) {
				if (*p != '.')
					extension[extlen++] = toupper(*p);
				p++;
			}
			extension[extlen] = '\0';
		} else {
			dot_present = false;
		}
	}

	p = longname;
	if (*p == '.') {
		p++;
		longname++;
	}
	while (*p && (baselen < 5)) {
		if (*p != '.')
			base[baselen++] = toupper(*p);
		p++;
	}

	base[baselen] = MAGIC_CHAR;
	memcpy(out, base, baselen + 1);

	ptr = longname;
	len = strlen(longname);
	for (; len > 0; len--, ptr++)
		csum += *ptr;

	csum = csum % (MANGLE_BASE * MANGLE_BASE);
	out[baselen + 1] = mangle(csum / MANGLE_BASE);
	out[baselen + 2] = mangle(csum);
	out[baselen + 3] = PERIOD;

	if (dot_present)
		memcpy(&out[baselen + 4], extension, 4);
	else
		out[baselen + 4] = '\0';
	smbConvertToUTF16((__le16 *)shortname, out, PATH_MAX,
			  conn->local_nls, 0);
	len = strlen(out) * 2;
	return len;
}

static int __smb2_negotiate(struct ksmbd_conn *conn)
{
	return (conn->dialect >= SMB20_PROT_ID &&
		conn->dialect <= SMB311_PROT_ID);
}

static int smb_handle_negotiate(struct ksmbd_work *work)
{
	struct smb_negotiate_rsp *neg_rsp = work->response_buf;

	ksmbd_debug(SMB, "Unsupported SMB protocol\n");
	neg_rsp->hdr.Status.CifsError = STATUS_INVALID_LOGON_TYPE;
	return -EINVAL;
}

int ksmbd_smb_negotiate_common(struct ksmbd_work *work, unsigned int command)
{
	struct ksmbd_conn *conn = work->conn;
	int ret;

	conn->dialect = ksmbd_negotiate_smb_dialect(work->request_buf);
	ksmbd_debug(SMB, "conn->dialect 0x%x\n", conn->dialect);

	if (command == SMB2_NEGOTIATE_HE) {
		struct smb2_hdr *smb2_hdr = work->request_buf;

		if (smb2_hdr->ProtocolId != SMB2_PROTO_NUMBER) {
			ksmbd_debug(SMB, "Downgrade to SMB1 negotiation\n");
			command = SMB_COM_NEGOTIATE;
		}
	}

	if (command == SMB2_NEGOTIATE_HE) {
		ret = smb2_handle_negotiate(work);
		init_smb2_neg_rsp(work);
		return ret;
	}

	if (command == SMB_COM_NEGOTIATE) {
		if (__smb2_negotiate(conn)) {
			conn->need_neg = true;
			init_smb3_11_server(conn);
			init_smb2_neg_rsp(work);
			ksmbd_debug(SMB, "Upgrade to SMB2 negotiation\n");
			return 0;
		}
		return smb_handle_negotiate(work);
	}

	pr_err("Unknown SMB negotiation command: %u\n", command);
	return -EINVAL;
}

enum SHARED_MODE_ERRORS {
	SHARE_DELETE_ERROR,
	SHARE_READ_ERROR,
	SHARE_WRITE_ERROR,
	FILE_READ_ERROR,
	FILE_WRITE_ERROR,
	FILE_DELETE_ERROR,
};

static const char * const shared_mode_errors[] = {
	"Current access mode does not permit SHARE_DELETE",
	"Current access mode does not permit SHARE_READ",
	"Current access mode does not permit SHARE_WRITE",
	"Desired access mode does not permit FILE_READ",
	"Desired access mode does not permit FILE_WRITE",
	"Desired access mode does not permit FILE_DELETE",
};

static void smb_shared_mode_error(int error, struct ksmbd_file *prev_fp,
				  struct ksmbd_file *curr_fp)
{
	ksmbd_debug(SMB, "%s\n", shared_mode_errors[error]);
	ksmbd_debug(SMB, "Current mode: 0x%x Desired mode: 0x%x\n",
		    prev_fp->saccess, curr_fp->daccess);
}

int ksmbd_smb_check_shared_mode(struct file *filp, struct ksmbd_file *curr_fp)
{
	int rc = 0;
	struct ksmbd_file *prev_fp;

	/*
	 * Lookup fp in master fp list, and check desired access and
	 * shared mode between previous open and current open.
	 */
	read_lock(&curr_fp->f_ci->m_lock);
	list_for_each_entry(prev_fp, &curr_fp->f_ci->m_fp_list, node) {
		if (file_inode(filp) != file_inode(prev_fp->filp))
			continue;

		if (filp == prev_fp->filp)
			continue;

		if (ksmbd_stream_fd(prev_fp) && ksmbd_stream_fd(curr_fp))
			if (strcmp(prev_fp->stream.name, curr_fp->stream.name))
				continue;

		if (prev_fp->attrib_only != curr_fp->attrib_only)
			continue;

		if (!(prev_fp->saccess & FILE_SHARE_DELETE_LE) &&
		    curr_fp->daccess & FILE_DELETE_LE) {
			smb_shared_mode_error(SHARE_DELETE_ERROR,
					      prev_fp,
					      curr_fp);
			rc = -EPERM;
			break;
		}

		/*
		 * Only check FILE_SHARE_DELETE if stream opened and
		 * normal file opened.
		 */
		if (ksmbd_stream_fd(prev_fp) && !ksmbd_stream_fd(curr_fp))
			continue;

		if (!(prev_fp->saccess & FILE_SHARE_READ_LE) &&
		    curr_fp->daccess & (FILE_EXECUTE_LE | FILE_READ_DATA_LE)) {
			smb_shared_mode_error(SHARE_READ_ERROR,
					      prev_fp,
					      curr_fp);
			rc = -EPERM;
			break;
		}

		if (!(prev_fp->saccess & FILE_SHARE_WRITE_LE) &&
		    curr_fp->daccess & (FILE_WRITE_DATA_LE | FILE_APPEND_DATA_LE)) {
			smb_shared_mode_error(SHARE_WRITE_ERROR,
					      prev_fp,
					      curr_fp);
			rc = -EPERM;
			break;
		}

		if (prev_fp->daccess & (FILE_EXECUTE_LE | FILE_READ_DATA_LE) &&
		    !(curr_fp->saccess & FILE_SHARE_READ_LE)) {
			smb_shared_mode_error(FILE_READ_ERROR,
					      prev_fp,
					      curr_fp);
			rc = -EPERM;
			break;
		}

		if (prev_fp->daccess & (FILE_WRITE_DATA_LE | FILE_APPEND_DATA_LE) &&
		    !(curr_fp->saccess & FILE_SHARE_WRITE_LE)) {
			smb_shared_mode_error(FILE_WRITE_ERROR,
					      prev_fp,
					      curr_fp);
			rc = -EPERM;
			break;
		}

		if (prev_fp->daccess & FILE_DELETE_LE &&
		    !(curr_fp->saccess & FILE_SHARE_DELETE_LE)) {
			smb_shared_mode_error(FILE_DELETE_ERROR,
					      prev_fp,
					      curr_fp);
			rc = -EPERM;
			break;
		}
	}
	read_unlock(&curr_fp->f_ci->m_lock);

	return rc;
}

bool is_asterisk(char *p)
{
	return p && p[0] == '*';
}

int ksmbd_override_fsids(struct ksmbd_work *work)
{
	struct ksmbd_session *sess = work->sess;
	struct ksmbd_share_config *share = work->tcon->share_conf;
	struct cred *cred;
	struct group_info *gi;
	unsigned int uid;
	unsigned int gid;

	uid = user_uid(sess->user);
	gid = user_gid(sess->user);
	if (share->force_uid != KSMBD_SHARE_INVALID_UID)
		uid = share->force_uid;
	if (share->force_gid != KSMBD_SHARE_INVALID_GID)
		gid = share->force_gid;

	cred = prepare_kernel_cred(NULL);
	if (!cred)
		return -ENOMEM;

	cred->fsuid = make_kuid(current_user_ns(), uid);
	cred->fsgid = make_kgid(current_user_ns(), gid);

	gi = groups_alloc(0);
	if (!gi) {
		abort_creds(cred);
		return -ENOMEM;
	}
	set_groups(cred, gi);
	put_group_info(gi);

	if (!uid_eq(cred->fsuid, GLOBAL_ROOT_UID))
		cred->cap_effective = cap_drop_fs_set(cred->cap_effective);

	WARN_ON(work->saved_cred);
	work->saved_cred = override_creds(cred);
	if (!work->saved_cred) {
		abort_creds(cred);
		return -EINVAL;
	}
	return 0;
}

void ksmbd_revert_fsids(struct ksmbd_work *work)
{
	const struct cred *cred;

	WARN_ON(!work->saved_cred);

	cred = current_cred();
	revert_creds(work->saved_cred);
	put_cred(cred);
	work->saved_cred = NULL;
}

__le32 smb_map_generic_desired_access(__le32 daccess)
{
	if (daccess & FILE_GENERIC_READ_LE) {
		daccess |= cpu_to_le32(GENERIC_READ_FLAGS);
		daccess &= ~FILE_GENERIC_READ_LE;
	}

	if (daccess & FILE_GENERIC_WRITE_LE) {
		daccess |= cpu_to_le32(GENERIC_WRITE_FLAGS);
		daccess &= ~FILE_GENERIC_WRITE_LE;
	}

	if (daccess & FILE_GENERIC_EXECUTE_LE) {
		daccess |= cpu_to_le32(GENERIC_EXECUTE_FLAGS);
		daccess &= ~FILE_GENERIC_EXECUTE_LE;
	}

	if (daccess & FILE_GENERIC_ALL_LE) {
		daccess |= cpu_to_le32(GENERIC_ALL_FLAGS);
		daccess &= ~FILE_GENERIC_ALL_LE;
	}

	return daccess;
}