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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (C) 2018 Samsung Electronics Co., Ltd.
4 * Copyright (C) 2018 Namjae Jeon <linkinjeon@kernel.org>
5 */
6
7#include <linux/user_namespace.h>
8
9#include "smb_common.h"
10#include "server.h"
11#include "misc.h"
12#include "smbstatus.h"
13#include "connection.h"
14#include "ksmbd_work.h"
15#include "mgmt/user_session.h"
16#include "mgmt/user_config.h"
17#include "mgmt/tree_connect.h"
18#include "mgmt/share_config.h"
19
20/*for shortname implementation */
21static const char basechars[43] = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ_-!@#$%";
22#define MANGLE_BASE (sizeof(basechars) / sizeof(char) - 1)
23#define MAGIC_CHAR '~'
24#define PERIOD '.'
25#define mangle(V) ((char)(basechars[(V) % MANGLE_BASE]))
26
27struct smb_protocol {
28 int index;
29 char *name;
30 char *prot;
31 __u16 prot_id;
32};
33
34static struct smb_protocol smb1_protos[] = {
35 {
36 SMB21_PROT,
37 "\2SMB 2.1",
38 "SMB2_10",
39 SMB21_PROT_ID
40 },
41 {
42 SMB2X_PROT,
43 "\2SMB 2.???",
44 "SMB2_22",
45 SMB2X_PROT_ID
46 },
47};
48
49static struct smb_protocol smb2_protos[] = {
50 {
51 SMB21_PROT,
52 "\2SMB 2.1",
53 "SMB2_10",
54 SMB21_PROT_ID
55 },
56 {
57 SMB30_PROT,
58 "\2SMB 3.0",
59 "SMB3_00",
60 SMB30_PROT_ID
61 },
62 {
63 SMB302_PROT,
64 "\2SMB 3.02",
65 "SMB3_02",
66 SMB302_PROT_ID
67 },
68 {
69 SMB311_PROT,
70 "\2SMB 3.1.1",
71 "SMB3_11",
72 SMB311_PROT_ID
73 },
74};
75
76unsigned int ksmbd_server_side_copy_max_chunk_count(void)
77{
78 return 256;
79}
80
81unsigned int ksmbd_server_side_copy_max_chunk_size(void)
82{
83 return (2U << 30) - 1;
84}
85
86unsigned int ksmbd_server_side_copy_max_total_size(void)
87{
88 return (2U << 30) - 1;
89}
90
91inline int ksmbd_min_protocol(void)
92{
93 return SMB21_PROT;
94}
95
96inline int ksmbd_max_protocol(void)
97{
98 return SMB311_PROT;
99}
100
101int ksmbd_lookup_protocol_idx(char *str)
102{
103 int offt = ARRAY_SIZE(smb1_protos) - 1;
104 int len = strlen(str);
105
106 while (offt >= 0) {
107 if (!strncmp(str, smb1_protos[offt].prot, len)) {
108 ksmbd_debug(SMB, "selected %s dialect idx = %d\n",
109 smb1_protos[offt].prot, offt);
110 return smb1_protos[offt].index;
111 }
112 offt--;
113 }
114
115 offt = ARRAY_SIZE(smb2_protos) - 1;
116 while (offt >= 0) {
117 if (!strncmp(str, smb2_protos[offt].prot, len)) {
118 ksmbd_debug(SMB, "selected %s dialect idx = %d\n",
119 smb2_protos[offt].prot, offt);
120 return smb2_protos[offt].index;
121 }
122 offt--;
123 }
124 return -1;
125}
126
127/**
128 * ksmbd_verify_smb_message() - check for valid smb2 request header
129 * @work: smb work
130 *
131 * check for valid smb signature and packet direction(request/response)
132 *
133 * Return: 0 on success, otherwise -EINVAL
134 */
135int ksmbd_verify_smb_message(struct ksmbd_work *work)
136{
137 struct smb2_hdr *smb2_hdr = ksmbd_req_buf_next(work);
138 struct smb_hdr *hdr;
139
140 if (smb2_hdr->ProtocolId == SMB2_PROTO_NUMBER)
141 return ksmbd_smb2_check_message(work);
142
143 hdr = work->request_buf;
144 if (*(__le32 *)hdr->Protocol == SMB1_PROTO_NUMBER &&
145 hdr->Command == SMB_COM_NEGOTIATE) {
146 work->conn->outstanding_credits++;
147 return 0;
148 }
149
150 return -EINVAL;
151}
152
153/**
154 * ksmbd_smb_request() - check for valid smb request type
155 * @conn: connection instance
156 *
157 * Return: true on success, otherwise false
158 */
159bool ksmbd_smb_request(struct ksmbd_conn *conn)
160{
161 __le32 *proto;
162
163 if (conn->request_buf[0] != 0)
164 return false;
165
166 proto = (__le32 *)smb2_get_msg(conn->request_buf);
167 if (*proto == SMB2_COMPRESSION_TRANSFORM_ID) {
168 pr_err_ratelimited("smb2 compression not support yet");
169 return false;
170 }
171
172 if (*proto != SMB1_PROTO_NUMBER &&
173 *proto != SMB2_PROTO_NUMBER &&
174 *proto != SMB2_TRANSFORM_PROTO_NUM)
175 return false;
176
177 return true;
178}
179
180static bool supported_protocol(int idx)
181{
182 if (idx == SMB2X_PROT &&
183 (server_conf.min_protocol >= SMB21_PROT ||
184 server_conf.max_protocol <= SMB311_PROT))
185 return true;
186
187 return (server_conf.min_protocol <= idx &&
188 idx <= server_conf.max_protocol);
189}
190
191static char *next_dialect(char *dialect, int *next_off, int bcount)
192{
193 dialect = dialect + *next_off;
194 *next_off = strnlen(dialect, bcount);
195 if (dialect[*next_off] != '\0')
196 return NULL;
197 return dialect;
198}
199
200static int ksmbd_lookup_dialect_by_name(char *cli_dialects, __le16 byte_count)
201{
202 int i, seq_num, bcount, next;
203 char *dialect;
204
205 for (i = ARRAY_SIZE(smb1_protos) - 1; i >= 0; i--) {
206 seq_num = 0;
207 next = 0;
208 dialect = cli_dialects;
209 bcount = le16_to_cpu(byte_count);
210 do {
211 dialect = next_dialect(dialect, &next, bcount);
212 if (!dialect)
213 break;
214 ksmbd_debug(SMB, "client requested dialect %s\n",
215 dialect);
216 if (!strcmp(dialect, smb1_protos[i].name)) {
217 if (supported_protocol(smb1_protos[i].index)) {
218 ksmbd_debug(SMB,
219 "selected %s dialect\n",
220 smb1_protos[i].name);
221 if (smb1_protos[i].index == SMB1_PROT)
222 return seq_num;
223 return smb1_protos[i].prot_id;
224 }
225 }
226 seq_num++;
227 bcount -= (++next);
228 } while (bcount > 0);
229 }
230
231 return BAD_PROT_ID;
232}
233
234int ksmbd_lookup_dialect_by_id(__le16 *cli_dialects, __le16 dialects_count)
235{
236 int i;
237 int count;
238
239 for (i = ARRAY_SIZE(smb2_protos) - 1; i >= 0; i--) {
240 count = le16_to_cpu(dialects_count);
241 while (--count >= 0) {
242 ksmbd_debug(SMB, "client requested dialect 0x%x\n",
243 le16_to_cpu(cli_dialects[count]));
244 if (le16_to_cpu(cli_dialects[count]) !=
245 smb2_protos[i].prot_id)
246 continue;
247
248 if (supported_protocol(smb2_protos[i].index)) {
249 ksmbd_debug(SMB, "selected %s dialect\n",
250 smb2_protos[i].name);
251 return smb2_protos[i].prot_id;
252 }
253 }
254 }
255
256 return BAD_PROT_ID;
257}
258
259static int ksmbd_negotiate_smb_dialect(void *buf)
260{
261 int smb_buf_length = get_rfc1002_len(buf);
262 __le32 proto = ((struct smb2_hdr *)smb2_get_msg(buf))->ProtocolId;
263
264 if (proto == SMB2_PROTO_NUMBER) {
265 struct smb2_negotiate_req *req;
266 int smb2_neg_size =
267 offsetof(struct smb2_negotiate_req, Dialects);
268
269 req = (struct smb2_negotiate_req *)smb2_get_msg(buf);
270 if (smb2_neg_size > smb_buf_length)
271 goto err_out;
272
273 if (struct_size(req, Dialects, le16_to_cpu(req->DialectCount)) >
274 smb_buf_length)
275 goto err_out;
276
277 return ksmbd_lookup_dialect_by_id(req->Dialects,
278 req->DialectCount);
279 }
280
281 proto = *(__le32 *)((struct smb_hdr *)buf)->Protocol;
282 if (proto == SMB1_PROTO_NUMBER) {
283 struct smb_negotiate_req *req;
284
285 req = (struct smb_negotiate_req *)buf;
286 if (le16_to_cpu(req->ByteCount) < 2)
287 goto err_out;
288
289 if (offsetof(struct smb_negotiate_req, DialectsArray) - 4 +
290 le16_to_cpu(req->ByteCount) > smb_buf_length) {
291 goto err_out;
292 }
293
294 return ksmbd_lookup_dialect_by_name(req->DialectsArray,
295 req->ByteCount);
296 }
297
298err_out:
299 return BAD_PROT_ID;
300}
301
302#define SMB_COM_NEGOTIATE_EX 0x0
303
304/**
305 * get_smb1_cmd_val() - get smb command value from smb header
306 * @work: smb work containing smb header
307 *
308 * Return: smb command value
309 */
310static u16 get_smb1_cmd_val(struct ksmbd_work *work)
311{
312 return SMB_COM_NEGOTIATE_EX;
313}
314
315/**
316 * init_smb1_rsp_hdr() - initialize smb negotiate response header
317 * @work: smb work containing smb request
318 *
319 * Return: 0 on success, otherwise -EINVAL
320 */
321static int init_smb1_rsp_hdr(struct ksmbd_work *work)
322{
323 struct smb_hdr *rsp_hdr = (struct smb_hdr *)work->response_buf;
324 struct smb_hdr *rcv_hdr = (struct smb_hdr *)work->request_buf;
325
326 rsp_hdr->Command = SMB_COM_NEGOTIATE;
327 *(__le32 *)rsp_hdr->Protocol = SMB1_PROTO_NUMBER;
328 rsp_hdr->Flags = SMBFLG_RESPONSE;
329 rsp_hdr->Flags2 = SMBFLG2_UNICODE | SMBFLG2_ERR_STATUS |
330 SMBFLG2_EXT_SEC | SMBFLG2_IS_LONG_NAME;
331 rsp_hdr->Pid = rcv_hdr->Pid;
332 rsp_hdr->Mid = rcv_hdr->Mid;
333 return 0;
334}
335
336/**
337 * smb1_check_user_session() - check for valid session for a user
338 * @work: smb work containing smb request buffer
339 *
340 * Return: 0 on success, otherwise error
341 */
342static int smb1_check_user_session(struct ksmbd_work *work)
343{
344 unsigned int cmd = work->conn->ops->get_cmd_val(work);
345
346 if (cmd == SMB_COM_NEGOTIATE_EX)
347 return 0;
348
349 return -EINVAL;
350}
351
352/**
353 * smb1_allocate_rsp_buf() - allocate response buffer for a command
354 * @work: smb work containing smb request
355 *
356 * Return: 0 on success, otherwise -ENOMEM
357 */
358static int smb1_allocate_rsp_buf(struct ksmbd_work *work)
359{
360 work->response_buf = kzalloc(MAX_CIFS_SMALL_BUFFER_SIZE,
361 GFP_KERNEL);
362 work->response_sz = MAX_CIFS_SMALL_BUFFER_SIZE;
363
364 if (!work->response_buf) {
365 pr_err("Failed to allocate %u bytes buffer\n",
366 MAX_CIFS_SMALL_BUFFER_SIZE);
367 return -ENOMEM;
368 }
369
370 return 0;
371}
372
373/**
374 * set_smb1_rsp_status() - set error type in smb response header
375 * @work: smb work containing smb response header
376 * @err: error code to set in response
377 */
378static void set_smb1_rsp_status(struct ksmbd_work *work, __le32 err)
379{
380 work->send_no_response = 1;
381}
382
383static struct smb_version_ops smb1_server_ops = {
384 .get_cmd_val = get_smb1_cmd_val,
385 .init_rsp_hdr = init_smb1_rsp_hdr,
386 .allocate_rsp_buf = smb1_allocate_rsp_buf,
387 .check_user_session = smb1_check_user_session,
388 .set_rsp_status = set_smb1_rsp_status,
389};
390
391static int smb1_negotiate(struct ksmbd_work *work)
392{
393 return ksmbd_smb_negotiate_common(work, SMB_COM_NEGOTIATE);
394}
395
396static struct smb_version_cmds smb1_server_cmds[1] = {
397 [SMB_COM_NEGOTIATE_EX] = { .proc = smb1_negotiate, },
398};
399
400static int init_smb1_server(struct ksmbd_conn *conn)
401{
402 conn->ops = &smb1_server_ops;
403 conn->cmds = smb1_server_cmds;
404 conn->max_cmds = ARRAY_SIZE(smb1_server_cmds);
405 return 0;
406}
407
408int ksmbd_init_smb_server(struct ksmbd_work *work)
409{
410 struct ksmbd_conn *conn = work->conn;
411 __le32 proto;
412
413 proto = *(__le32 *)((struct smb_hdr *)work->request_buf)->Protocol;
414 if (conn->need_neg == false) {
415 if (proto == SMB1_PROTO_NUMBER)
416 return -EINVAL;
417 return 0;
418 }
419
420 if (proto == SMB1_PROTO_NUMBER)
421 return init_smb1_server(conn);
422 return init_smb3_11_server(conn);
423}
424
425int ksmbd_populate_dot_dotdot_entries(struct ksmbd_work *work, int info_level,
426 struct ksmbd_file *dir,
427 struct ksmbd_dir_info *d_info,
428 char *search_pattern,
429 int (*fn)(struct ksmbd_conn *, int,
430 struct ksmbd_dir_info *,
431 struct ksmbd_kstat *))
432{
433 int i, rc = 0;
434 struct ksmbd_conn *conn = work->conn;
435 struct mnt_idmap *idmap = file_mnt_idmap(dir->filp);
436
437 for (i = 0; i < 2; i++) {
438 struct kstat kstat;
439 struct ksmbd_kstat ksmbd_kstat;
440 struct dentry *dentry;
441
442 if (!dir->dot_dotdot[i]) { /* fill dot entry info */
443 if (i == 0) {
444 d_info->name = ".";
445 d_info->name_len = 1;
446 dentry = dir->filp->f_path.dentry;
447 } else {
448 d_info->name = "..";
449 d_info->name_len = 2;
450 dentry = dir->filp->f_path.dentry->d_parent;
451 }
452
453 if (!match_pattern(d_info->name, d_info->name_len,
454 search_pattern)) {
455 dir->dot_dotdot[i] = 1;
456 continue;
457 }
458
459 ksmbd_kstat.kstat = &kstat;
460 ksmbd_vfs_fill_dentry_attrs(work,
461 idmap,
462 dentry,
463 &ksmbd_kstat);
464 rc = fn(conn, info_level, d_info, &ksmbd_kstat);
465 if (rc)
466 break;
467 if (d_info->out_buf_len <= 0)
468 break;
469
470 dir->dot_dotdot[i] = 1;
471 if (d_info->flags & SMB2_RETURN_SINGLE_ENTRY) {
472 d_info->out_buf_len = 0;
473 break;
474 }
475 }
476 }
477
478 return rc;
479}
480
481/**
482 * ksmbd_extract_shortname() - get shortname from long filename
483 * @conn: connection instance
484 * @longname: source long filename
485 * @shortname: destination short filename
486 *
487 * Return: shortname length or 0 when source long name is '.' or '..'
488 * TODO: Though this function comforms the restriction of 8.3 Filename spec,
489 * but the result is different with Windows 7's one. need to check.
490 */
491int ksmbd_extract_shortname(struct ksmbd_conn *conn, const char *longname,
492 char *shortname)
493{
494 const char *p;
495 char base[9], extension[4];
496 char out[13] = {0};
497 int baselen = 0;
498 int extlen = 0, len = 0;
499 unsigned int csum = 0;
500 const unsigned char *ptr;
501 bool dot_present = true;
502
503 p = longname;
504 if ((*p == '.') || (!(strcmp(p, "..")))) {
505 /*no mangling required */
506 return 0;
507 }
508
509 p = strrchr(longname, '.');
510 if (p == longname) { /*name starts with a dot*/
511 strscpy(extension, "___", strlen("___"));
512 } else {
513 if (p) {
514 p++;
515 while (*p && extlen < 3) {
516 if (*p != '.')
517 extension[extlen++] = toupper(*p);
518 p++;
519 }
520 extension[extlen] = '\0';
521 } else {
522 dot_present = false;
523 }
524 }
525
526 p = longname;
527 if (*p == '.') {
528 p++;
529 longname++;
530 }
531 while (*p && (baselen < 5)) {
532 if (*p != '.')
533 base[baselen++] = toupper(*p);
534 p++;
535 }
536
537 base[baselen] = MAGIC_CHAR;
538 memcpy(out, base, baselen + 1);
539
540 ptr = longname;
541 len = strlen(longname);
542 for (; len > 0; len--, ptr++)
543 csum += *ptr;
544
545 csum = csum % (MANGLE_BASE * MANGLE_BASE);
546 out[baselen + 1] = mangle(csum / MANGLE_BASE);
547 out[baselen + 2] = mangle(csum);
548 out[baselen + 3] = PERIOD;
549
550 if (dot_present)
551 memcpy(out + baselen + 4, extension, 4);
552 else
553 out[baselen + 4] = '\0';
554 smbConvertToUTF16((__le16 *)shortname, out, PATH_MAX,
555 conn->local_nls, 0);
556 len = strlen(out) * 2;
557 return len;
558}
559
560static int __smb2_negotiate(struct ksmbd_conn *conn)
561{
562 return (conn->dialect >= SMB20_PROT_ID &&
563 conn->dialect <= SMB311_PROT_ID);
564}
565
566static int smb_handle_negotiate(struct ksmbd_work *work)
567{
568 struct smb_negotiate_rsp *neg_rsp = work->response_buf;
569
570 ksmbd_debug(SMB, "Unsupported SMB1 protocol\n");
571
572 if (ksmbd_iov_pin_rsp(work, (void *)neg_rsp,
573 sizeof(struct smb_negotiate_rsp) - 4))
574 return -ENOMEM;
575
576 neg_rsp->hdr.Status.CifsError = STATUS_SUCCESS;
577 neg_rsp->hdr.WordCount = 1;
578 neg_rsp->DialectIndex = cpu_to_le16(work->conn->dialect);
579 neg_rsp->ByteCount = 0;
580 return 0;
581}
582
583int ksmbd_smb_negotiate_common(struct ksmbd_work *work, unsigned int command)
584{
585 struct ksmbd_conn *conn = work->conn;
586 int ret;
587
588 conn->dialect =
589 ksmbd_negotiate_smb_dialect(work->request_buf);
590 ksmbd_debug(SMB, "conn->dialect 0x%x\n", conn->dialect);
591
592 if (command == SMB2_NEGOTIATE_HE) {
593 ret = smb2_handle_negotiate(work);
594 return ret;
595 }
596
597 if (command == SMB_COM_NEGOTIATE) {
598 if (__smb2_negotiate(conn)) {
599 init_smb3_11_server(conn);
600 init_smb2_neg_rsp(work);
601 ksmbd_debug(SMB, "Upgrade to SMB2 negotiation\n");
602 return 0;
603 }
604 return smb_handle_negotiate(work);
605 }
606
607 pr_err("Unknown SMB negotiation command: %u\n", command);
608 return -EINVAL;
609}
610
611enum SHARED_MODE_ERRORS {
612 SHARE_DELETE_ERROR,
613 SHARE_READ_ERROR,
614 SHARE_WRITE_ERROR,
615 FILE_READ_ERROR,
616 FILE_WRITE_ERROR,
617 FILE_DELETE_ERROR,
618};
619
620static const char * const shared_mode_errors[] = {
621 "Current access mode does not permit SHARE_DELETE",
622 "Current access mode does not permit SHARE_READ",
623 "Current access mode does not permit SHARE_WRITE",
624 "Desired access mode does not permit FILE_READ",
625 "Desired access mode does not permit FILE_WRITE",
626 "Desired access mode does not permit FILE_DELETE",
627};
628
629static void smb_shared_mode_error(int error, struct ksmbd_file *prev_fp,
630 struct ksmbd_file *curr_fp)
631{
632 ksmbd_debug(SMB, "%s\n", shared_mode_errors[error]);
633 ksmbd_debug(SMB, "Current mode: 0x%x Desired mode: 0x%x\n",
634 prev_fp->saccess, curr_fp->daccess);
635}
636
637int ksmbd_smb_check_shared_mode(struct file *filp, struct ksmbd_file *curr_fp)
638{
639 int rc = 0;
640 struct ksmbd_file *prev_fp;
641
642 /*
643 * Lookup fp in master fp list, and check desired access and
644 * shared mode between previous open and current open.
645 */
646 read_lock(&curr_fp->f_ci->m_lock);
647 list_for_each_entry(prev_fp, &curr_fp->f_ci->m_fp_list, node) {
648 if (file_inode(filp) != file_inode(prev_fp->filp))
649 continue;
650
651 if (filp == prev_fp->filp)
652 continue;
653
654 if (ksmbd_stream_fd(prev_fp) && ksmbd_stream_fd(curr_fp))
655 if (strcmp(prev_fp->stream.name, curr_fp->stream.name))
656 continue;
657
658 if (prev_fp->attrib_only != curr_fp->attrib_only)
659 continue;
660
661 if (!(prev_fp->saccess & FILE_SHARE_DELETE_LE) &&
662 curr_fp->daccess & FILE_DELETE_LE) {
663 smb_shared_mode_error(SHARE_DELETE_ERROR,
664 prev_fp,
665 curr_fp);
666 rc = -EPERM;
667 break;
668 }
669
670 /*
671 * Only check FILE_SHARE_DELETE if stream opened and
672 * normal file opened.
673 */
674 if (ksmbd_stream_fd(prev_fp) && !ksmbd_stream_fd(curr_fp))
675 continue;
676
677 if (!(prev_fp->saccess & FILE_SHARE_READ_LE) &&
678 curr_fp->daccess & (FILE_EXECUTE_LE | FILE_READ_DATA_LE)) {
679 smb_shared_mode_error(SHARE_READ_ERROR,
680 prev_fp,
681 curr_fp);
682 rc = -EPERM;
683 break;
684 }
685
686 if (!(prev_fp->saccess & FILE_SHARE_WRITE_LE) &&
687 curr_fp->daccess & (FILE_WRITE_DATA_LE | FILE_APPEND_DATA_LE)) {
688 smb_shared_mode_error(SHARE_WRITE_ERROR,
689 prev_fp,
690 curr_fp);
691 rc = -EPERM;
692 break;
693 }
694
695 if (prev_fp->daccess & (FILE_EXECUTE_LE | FILE_READ_DATA_LE) &&
696 !(curr_fp->saccess & FILE_SHARE_READ_LE)) {
697 smb_shared_mode_error(FILE_READ_ERROR,
698 prev_fp,
699 curr_fp);
700 rc = -EPERM;
701 break;
702 }
703
704 if (prev_fp->daccess & (FILE_WRITE_DATA_LE | FILE_APPEND_DATA_LE) &&
705 !(curr_fp->saccess & FILE_SHARE_WRITE_LE)) {
706 smb_shared_mode_error(FILE_WRITE_ERROR,
707 prev_fp,
708 curr_fp);
709 rc = -EPERM;
710 break;
711 }
712
713 if (prev_fp->daccess & FILE_DELETE_LE &&
714 !(curr_fp->saccess & FILE_SHARE_DELETE_LE)) {
715 smb_shared_mode_error(FILE_DELETE_ERROR,
716 prev_fp,
717 curr_fp);
718 rc = -EPERM;
719 break;
720 }
721 }
722 read_unlock(&curr_fp->f_ci->m_lock);
723
724 return rc;
725}
726
727bool is_asterisk(char *p)
728{
729 return p && p[0] == '*';
730}
731
732int ksmbd_override_fsids(struct ksmbd_work *work)
733{
734 struct ksmbd_session *sess = work->sess;
735 struct ksmbd_share_config *share = work->tcon->share_conf;
736 struct cred *cred;
737 struct group_info *gi;
738 unsigned int uid;
739 unsigned int gid;
740
741 uid = user_uid(sess->user);
742 gid = user_gid(sess->user);
743 if (share->force_uid != KSMBD_SHARE_INVALID_UID)
744 uid = share->force_uid;
745 if (share->force_gid != KSMBD_SHARE_INVALID_GID)
746 gid = share->force_gid;
747
748 cred = prepare_kernel_cred(&init_task);
749 if (!cred)
750 return -ENOMEM;
751
752 cred->fsuid = make_kuid(&init_user_ns, uid);
753 cred->fsgid = make_kgid(&init_user_ns, gid);
754
755 gi = groups_alloc(0);
756 if (!gi) {
757 abort_creds(cred);
758 return -ENOMEM;
759 }
760 set_groups(cred, gi);
761 put_group_info(gi);
762
763 if (!uid_eq(cred->fsuid, GLOBAL_ROOT_UID))
764 cred->cap_effective = cap_drop_fs_set(cred->cap_effective);
765
766 WARN_ON(work->saved_cred);
767 work->saved_cred = override_creds(cred);
768 if (!work->saved_cred) {
769 abort_creds(cred);
770 return -EINVAL;
771 }
772 return 0;
773}
774
775void ksmbd_revert_fsids(struct ksmbd_work *work)
776{
777 const struct cred *cred;
778
779 WARN_ON(!work->saved_cred);
780
781 cred = current_cred();
782 revert_creds(work->saved_cred);
783 put_cred(cred);
784 work->saved_cred = NULL;
785}
786
787__le32 smb_map_generic_desired_access(__le32 daccess)
788{
789 if (daccess & FILE_GENERIC_READ_LE) {
790 daccess |= cpu_to_le32(GENERIC_READ_FLAGS);
791 daccess &= ~FILE_GENERIC_READ_LE;
792 }
793
794 if (daccess & FILE_GENERIC_WRITE_LE) {
795 daccess |= cpu_to_le32(GENERIC_WRITE_FLAGS);
796 daccess &= ~FILE_GENERIC_WRITE_LE;
797 }
798
799 if (daccess & FILE_GENERIC_EXECUTE_LE) {
800 daccess |= cpu_to_le32(GENERIC_EXECUTE_FLAGS);
801 daccess &= ~FILE_GENERIC_EXECUTE_LE;
802 }
803
804 if (daccess & FILE_GENERIC_ALL_LE) {
805 daccess |= cpu_to_le32(GENERIC_ALL_FLAGS);
806 daccess &= ~FILE_GENERIC_ALL_LE;
807 }
808
809 return daccess;
810}