ocfs2: fix data corruption after conversion from inline format
[platform/kernel/linux-starfive.git] / fs / ksmbd / smb_common.c
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 "smb_common.h"
8 #include "server.h"
9 #include "misc.h"
10 #include "smbstatus.h"
11 #include "connection.h"
12 #include "ksmbd_work.h"
13 #include "mgmt/user_session.h"
14 #include "mgmt/user_config.h"
15 #include "mgmt/tree_connect.h"
16 #include "mgmt/share_config.h"
17
18 /*for shortname implementation */
19 static const char basechars[43] = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ_-!@#$%";
20 #define MANGLE_BASE (sizeof(basechars) / sizeof(char) - 1)
21 #define MAGIC_CHAR '~'
22 #define PERIOD '.'
23 #define mangle(V) ((char)(basechars[(V) % MANGLE_BASE]))
24
25 struct smb_protocol {
26         int             index;
27         char            *name;
28         char            *prot;
29         __u16           prot_id;
30 };
31
32 static struct smb_protocol smb1_protos[] = {
33         {
34                 SMB21_PROT,
35                 "\2SMB 2.1",
36                 "SMB2_10",
37                 SMB21_PROT_ID
38         },
39         {
40                 SMB2X_PROT,
41                 "\2SMB 2.???",
42                 "SMB2_22",
43                 SMB2X_PROT_ID
44         },
45 };
46
47 static struct smb_protocol smb2_protos[] = {
48         {
49                 SMB21_PROT,
50                 "\2SMB 2.1",
51                 "SMB2_10",
52                 SMB21_PROT_ID
53         },
54         {
55                 SMB30_PROT,
56                 "\2SMB 3.0",
57                 "SMB3_00",
58                 SMB30_PROT_ID
59         },
60         {
61                 SMB302_PROT,
62                 "\2SMB 3.02",
63                 "SMB3_02",
64                 SMB302_PROT_ID
65         },
66         {
67                 SMB311_PROT,
68                 "\2SMB 3.1.1",
69                 "SMB3_11",
70                 SMB311_PROT_ID
71         },
72 };
73
74 unsigned int ksmbd_server_side_copy_max_chunk_count(void)
75 {
76         return 256;
77 }
78
79 unsigned int ksmbd_server_side_copy_max_chunk_size(void)
80 {
81         return (2U << 30) - 1;
82 }
83
84 unsigned int ksmbd_server_side_copy_max_total_size(void)
85 {
86         return (2U << 30) - 1;
87 }
88
89 inline int ksmbd_min_protocol(void)
90 {
91         return SMB21_PROT;
92 }
93
94 inline int ksmbd_max_protocol(void)
95 {
96         return SMB311_PROT;
97 }
98
99 int ksmbd_lookup_protocol_idx(char *str)
100 {
101         int offt = ARRAY_SIZE(smb1_protos) - 1;
102         int len = strlen(str);
103
104         while (offt >= 0) {
105                 if (!strncmp(str, smb1_protos[offt].prot, len)) {
106                         ksmbd_debug(SMB, "selected %s dialect idx = %d\n",
107                                     smb1_protos[offt].prot, offt);
108                         return smb1_protos[offt].index;
109                 }
110                 offt--;
111         }
112
113         offt = ARRAY_SIZE(smb2_protos) - 1;
114         while (offt >= 0) {
115                 if (!strncmp(str, smb2_protos[offt].prot, len)) {
116                         ksmbd_debug(SMB, "selected %s dialect idx = %d\n",
117                                     smb2_protos[offt].prot, offt);
118                         return smb2_protos[offt].index;
119                 }
120                 offt--;
121         }
122         return -1;
123 }
124
125 /**
126  * ksmbd_verify_smb_message() - check for valid smb2 request header
127  * @work:       smb work
128  *
129  * check for valid smb signature and packet direction(request/response)
130  *
131  * Return:      0 on success, otherwise -EINVAL
132  */
133 int ksmbd_verify_smb_message(struct ksmbd_work *work)
134 {
135         struct smb2_hdr *smb2_hdr = work->request_buf + work->next_smb2_rcv_hdr_off;
136         struct smb_hdr *hdr;
137
138         if (smb2_hdr->ProtocolId == SMB2_PROTO_NUMBER)
139                 return ksmbd_smb2_check_message(work);
140
141         hdr = work->request_buf;
142         if (*(__le32 *)hdr->Protocol == SMB1_PROTO_NUMBER &&
143             hdr->Command == SMB_COM_NEGOTIATE)
144                 return 0;
145
146         return -EINVAL;
147 }
148
149 /**
150  * ksmbd_smb_request() - check for valid smb request type
151  * @conn:       connection instance
152  *
153  * Return:      true on success, otherwise false
154  */
155 bool ksmbd_smb_request(struct ksmbd_conn *conn)
156 {
157         return conn->request_buf[0] == 0;
158 }
159
160 static bool supported_protocol(int idx)
161 {
162         if (idx == SMB2X_PROT &&
163             (server_conf.min_protocol >= SMB21_PROT ||
164              server_conf.max_protocol <= SMB311_PROT))
165                 return true;
166
167         return (server_conf.min_protocol <= idx &&
168                 idx <= server_conf.max_protocol);
169 }
170
171 static char *next_dialect(char *dialect, int *next_off, int bcount)
172 {
173         dialect = dialect + *next_off;
174         *next_off = strnlen(dialect, bcount);
175         if (dialect[*next_off] != '\0')
176                 return NULL;
177         return dialect;
178 }
179
180 static int ksmbd_lookup_dialect_by_name(char *cli_dialects, __le16 byte_count)
181 {
182         int i, seq_num, bcount, next;
183         char *dialect;
184
185         for (i = ARRAY_SIZE(smb1_protos) - 1; i >= 0; i--) {
186                 seq_num = 0;
187                 next = 0;
188                 dialect = cli_dialects;
189                 bcount = le16_to_cpu(byte_count);
190                 do {
191                         dialect = next_dialect(dialect, &next, bcount);
192                         if (!dialect)
193                                 break;
194                         ksmbd_debug(SMB, "client requested dialect %s\n",
195                                     dialect);
196                         if (!strcmp(dialect, smb1_protos[i].name)) {
197                                 if (supported_protocol(smb1_protos[i].index)) {
198                                         ksmbd_debug(SMB,
199                                                     "selected %s dialect\n",
200                                                     smb1_protos[i].name);
201                                         if (smb1_protos[i].index == SMB1_PROT)
202                                                 return seq_num;
203                                         return smb1_protos[i].prot_id;
204                                 }
205                         }
206                         seq_num++;
207                         bcount -= (++next);
208                 } while (bcount > 0);
209         }
210
211         return BAD_PROT_ID;
212 }
213
214 int ksmbd_lookup_dialect_by_id(__le16 *cli_dialects, __le16 dialects_count)
215 {
216         int i;
217         int count;
218
219         for (i = ARRAY_SIZE(smb2_protos) - 1; i >= 0; i--) {
220                 count = le16_to_cpu(dialects_count);
221                 while (--count >= 0) {
222                         ksmbd_debug(SMB, "client requested dialect 0x%x\n",
223                                     le16_to_cpu(cli_dialects[count]));
224                         if (le16_to_cpu(cli_dialects[count]) !=
225                                         smb2_protos[i].prot_id)
226                                 continue;
227
228                         if (supported_protocol(smb2_protos[i].index)) {
229                                 ksmbd_debug(SMB, "selected %s dialect\n",
230                                             smb2_protos[i].name);
231                                 return smb2_protos[i].prot_id;
232                         }
233                 }
234         }
235
236         return BAD_PROT_ID;
237 }
238
239 static int ksmbd_negotiate_smb_dialect(void *buf)
240 {
241         int smb_buf_length = get_rfc1002_len(buf);
242         __le32 proto = ((struct smb2_hdr *)buf)->ProtocolId;
243
244         if (proto == SMB2_PROTO_NUMBER) {
245                 struct smb2_negotiate_req *req;
246                 int smb2_neg_size =
247                         offsetof(struct smb2_negotiate_req, Dialects) - 4;
248
249                 req = (struct smb2_negotiate_req *)buf;
250                 if (smb2_neg_size > smb_buf_length)
251                         goto err_out;
252
253                 if (smb2_neg_size + le16_to_cpu(req->DialectCount) * sizeof(__le16) >
254                     smb_buf_length)
255                         goto err_out;
256
257                 return ksmbd_lookup_dialect_by_id(req->Dialects,
258                                                   req->DialectCount);
259         }
260
261         proto = *(__le32 *)((struct smb_hdr *)buf)->Protocol;
262         if (proto == SMB1_PROTO_NUMBER) {
263                 struct smb_negotiate_req *req;
264
265                 req = (struct smb_negotiate_req *)buf;
266                 if (le16_to_cpu(req->ByteCount) < 2)
267                         goto err_out;
268
269                 if (offsetof(struct smb_negotiate_req, DialectsArray) - 4 +
270                         le16_to_cpu(req->ByteCount) > smb_buf_length) {
271                         goto err_out;
272                 }
273
274                 return ksmbd_lookup_dialect_by_name(req->DialectsArray,
275                                                     req->ByteCount);
276         }
277
278 err_out:
279         return BAD_PROT_ID;
280 }
281
282 int ksmbd_init_smb_server(struct ksmbd_work *work)
283 {
284         struct ksmbd_conn *conn = work->conn;
285
286         if (conn->need_neg == false)
287                 return 0;
288
289         init_smb3_11_server(conn);
290
291         if (conn->ops->get_cmd_val(work) != SMB_COM_NEGOTIATE)
292                 conn->need_neg = false;
293         return 0;
294 }
295
296 int ksmbd_populate_dot_dotdot_entries(struct ksmbd_work *work, int info_level,
297                                       struct ksmbd_file *dir,
298                                       struct ksmbd_dir_info *d_info,
299                                       char *search_pattern,
300                                       int (*fn)(struct ksmbd_conn *, int,
301                                                 struct ksmbd_dir_info *,
302                                                 struct ksmbd_kstat *))
303 {
304         int i, rc = 0;
305         struct ksmbd_conn *conn = work->conn;
306         struct user_namespace *user_ns = file_mnt_user_ns(dir->filp);
307
308         for (i = 0; i < 2; i++) {
309                 struct kstat kstat;
310                 struct ksmbd_kstat ksmbd_kstat;
311
312                 if (!dir->dot_dotdot[i]) { /* fill dot entry info */
313                         if (i == 0) {
314                                 d_info->name = ".";
315                                 d_info->name_len = 1;
316                         } else {
317                                 d_info->name = "..";
318                                 d_info->name_len = 2;
319                         }
320
321                         if (!match_pattern(d_info->name, d_info->name_len,
322                                            search_pattern)) {
323                                 dir->dot_dotdot[i] = 1;
324                                 continue;
325                         }
326
327                         ksmbd_kstat.kstat = &kstat;
328                         ksmbd_vfs_fill_dentry_attrs(work,
329                                                     user_ns,
330                                                     dir->filp->f_path.dentry->d_parent,
331                                                     &ksmbd_kstat);
332                         rc = fn(conn, info_level, d_info, &ksmbd_kstat);
333                         if (rc)
334                                 break;
335                         if (d_info->out_buf_len <= 0)
336                                 break;
337
338                         dir->dot_dotdot[i] = 1;
339                         if (d_info->flags & SMB2_RETURN_SINGLE_ENTRY) {
340                                 d_info->out_buf_len = 0;
341                                 break;
342                         }
343                 }
344         }
345
346         return rc;
347 }
348
349 /**
350  * ksmbd_extract_shortname() - get shortname from long filename
351  * @conn:       connection instance
352  * @longname:   source long filename
353  * @shortname:  destination short filename
354  *
355  * Return:      shortname length or 0 when source long name is '.' or '..'
356  * TODO: Though this function comforms the restriction of 8.3 Filename spec,
357  * but the result is different with Windows 7's one. need to check.
358  */
359 int ksmbd_extract_shortname(struct ksmbd_conn *conn, const char *longname,
360                             char *shortname)
361 {
362         const char *p;
363         char base[9], extension[4];
364         char out[13] = {0};
365         int baselen = 0;
366         int extlen = 0, len = 0;
367         unsigned int csum = 0;
368         const unsigned char *ptr;
369         bool dot_present = true;
370
371         p = longname;
372         if ((*p == '.') || (!(strcmp(p, "..")))) {
373                 /*no mangling required */
374                 return 0;
375         }
376
377         p = strrchr(longname, '.');
378         if (p == longname) { /*name starts with a dot*/
379                 strscpy(extension, "___", strlen("___"));
380         } else {
381                 if (p) {
382                         p++;
383                         while (*p && extlen < 3) {
384                                 if (*p != '.')
385                                         extension[extlen++] = toupper(*p);
386                                 p++;
387                         }
388                         extension[extlen] = '\0';
389                 } else {
390                         dot_present = false;
391                 }
392         }
393
394         p = longname;
395         if (*p == '.') {
396                 p++;
397                 longname++;
398         }
399         while (*p && (baselen < 5)) {
400                 if (*p != '.')
401                         base[baselen++] = toupper(*p);
402                 p++;
403         }
404
405         base[baselen] = MAGIC_CHAR;
406         memcpy(out, base, baselen + 1);
407
408         ptr = longname;
409         len = strlen(longname);
410         for (; len > 0; len--, ptr++)
411                 csum += *ptr;
412
413         csum = csum % (MANGLE_BASE * MANGLE_BASE);
414         out[baselen + 1] = mangle(csum / MANGLE_BASE);
415         out[baselen + 2] = mangle(csum);
416         out[baselen + 3] = PERIOD;
417
418         if (dot_present)
419                 memcpy(&out[baselen + 4], extension, 4);
420         else
421                 out[baselen + 4] = '\0';
422         smbConvertToUTF16((__le16 *)shortname, out, PATH_MAX,
423                           conn->local_nls, 0);
424         len = strlen(out) * 2;
425         return len;
426 }
427
428 static int __smb2_negotiate(struct ksmbd_conn *conn)
429 {
430         return (conn->dialect >= SMB21_PROT_ID &&
431                 conn->dialect <= SMB311_PROT_ID);
432 }
433
434 static int smb_handle_negotiate(struct ksmbd_work *work)
435 {
436         struct smb_negotiate_rsp *neg_rsp = work->response_buf;
437
438         ksmbd_debug(SMB, "Unsupported SMB protocol\n");
439         neg_rsp->hdr.Status.CifsError = STATUS_INVALID_LOGON_TYPE;
440         return -EINVAL;
441 }
442
443 int ksmbd_smb_negotiate_common(struct ksmbd_work *work, unsigned int command)
444 {
445         struct ksmbd_conn *conn = work->conn;
446         int ret;
447
448         conn->dialect = ksmbd_negotiate_smb_dialect(work->request_buf);
449         ksmbd_debug(SMB, "conn->dialect 0x%x\n", conn->dialect);
450
451         if (command == SMB2_NEGOTIATE_HE) {
452                 struct smb2_hdr *smb2_hdr = work->request_buf;
453
454                 if (smb2_hdr->ProtocolId != SMB2_PROTO_NUMBER) {
455                         ksmbd_debug(SMB, "Downgrade to SMB1 negotiation\n");
456                         command = SMB_COM_NEGOTIATE;
457                 }
458         }
459
460         if (command == SMB2_NEGOTIATE_HE && __smb2_negotiate(conn)) {
461                 ret = smb2_handle_negotiate(work);
462                 init_smb2_neg_rsp(work);
463                 return ret;
464         }
465
466         if (command == SMB_COM_NEGOTIATE) {
467                 if (__smb2_negotiate(conn)) {
468                         conn->need_neg = true;
469                         init_smb3_11_server(conn);
470                         init_smb2_neg_rsp(work);
471                         ksmbd_debug(SMB, "Upgrade to SMB2 negotiation\n");
472                         return 0;
473                 }
474                 return smb_handle_negotiate(work);
475         }
476
477         pr_err("Unknown SMB negotiation command: %u\n", command);
478         return -EINVAL;
479 }
480
481 enum SHARED_MODE_ERRORS {
482         SHARE_DELETE_ERROR,
483         SHARE_READ_ERROR,
484         SHARE_WRITE_ERROR,
485         FILE_READ_ERROR,
486         FILE_WRITE_ERROR,
487         FILE_DELETE_ERROR,
488 };
489
490 static const char * const shared_mode_errors[] = {
491         "Current access mode does not permit SHARE_DELETE",
492         "Current access mode does not permit SHARE_READ",
493         "Current access mode does not permit SHARE_WRITE",
494         "Desired access mode does not permit FILE_READ",
495         "Desired access mode does not permit FILE_WRITE",
496         "Desired access mode does not permit FILE_DELETE",
497 };
498
499 static void smb_shared_mode_error(int error, struct ksmbd_file *prev_fp,
500                                   struct ksmbd_file *curr_fp)
501 {
502         ksmbd_debug(SMB, "%s\n", shared_mode_errors[error]);
503         ksmbd_debug(SMB, "Current mode: 0x%x Desired mode: 0x%x\n",
504                     prev_fp->saccess, curr_fp->daccess);
505 }
506
507 int ksmbd_smb_check_shared_mode(struct file *filp, struct ksmbd_file *curr_fp)
508 {
509         int rc = 0;
510         struct ksmbd_file *prev_fp;
511
512         /*
513          * Lookup fp in master fp list, and check desired access and
514          * shared mode between previous open and current open.
515          */
516         read_lock(&curr_fp->f_ci->m_lock);
517         list_for_each_entry(prev_fp, &curr_fp->f_ci->m_fp_list, node) {
518                 if (file_inode(filp) != file_inode(prev_fp->filp))
519                         continue;
520
521                 if (filp == prev_fp->filp)
522                         continue;
523
524                 if (ksmbd_stream_fd(prev_fp) && ksmbd_stream_fd(curr_fp))
525                         if (strcmp(prev_fp->stream.name, curr_fp->stream.name))
526                                 continue;
527
528                 if (prev_fp->attrib_only != curr_fp->attrib_only)
529                         continue;
530
531                 if (!(prev_fp->saccess & FILE_SHARE_DELETE_LE) &&
532                     curr_fp->daccess & FILE_DELETE_LE) {
533                         smb_shared_mode_error(SHARE_DELETE_ERROR,
534                                               prev_fp,
535                                               curr_fp);
536                         rc = -EPERM;
537                         break;
538                 }
539
540                 /*
541                  * Only check FILE_SHARE_DELETE if stream opened and
542                  * normal file opened.
543                  */
544                 if (ksmbd_stream_fd(prev_fp) && !ksmbd_stream_fd(curr_fp))
545                         continue;
546
547                 if (!(prev_fp->saccess & FILE_SHARE_READ_LE) &&
548                     curr_fp->daccess & (FILE_EXECUTE_LE | FILE_READ_DATA_LE)) {
549                         smb_shared_mode_error(SHARE_READ_ERROR,
550                                               prev_fp,
551                                               curr_fp);
552                         rc = -EPERM;
553                         break;
554                 }
555
556                 if (!(prev_fp->saccess & FILE_SHARE_WRITE_LE) &&
557                     curr_fp->daccess & (FILE_WRITE_DATA_LE | FILE_APPEND_DATA_LE)) {
558                         smb_shared_mode_error(SHARE_WRITE_ERROR,
559                                               prev_fp,
560                                               curr_fp);
561                         rc = -EPERM;
562                         break;
563                 }
564
565                 if (prev_fp->daccess & (FILE_EXECUTE_LE | FILE_READ_DATA_LE) &&
566                     !(curr_fp->saccess & FILE_SHARE_READ_LE)) {
567                         smb_shared_mode_error(FILE_READ_ERROR,
568                                               prev_fp,
569                                               curr_fp);
570                         rc = -EPERM;
571                         break;
572                 }
573
574                 if (prev_fp->daccess & (FILE_WRITE_DATA_LE | FILE_APPEND_DATA_LE) &&
575                     !(curr_fp->saccess & FILE_SHARE_WRITE_LE)) {
576                         smb_shared_mode_error(FILE_WRITE_ERROR,
577                                               prev_fp,
578                                               curr_fp);
579                         rc = -EPERM;
580                         break;
581                 }
582
583                 if (prev_fp->daccess & FILE_DELETE_LE &&
584                     !(curr_fp->saccess & FILE_SHARE_DELETE_LE)) {
585                         smb_shared_mode_error(FILE_DELETE_ERROR,
586                                               prev_fp,
587                                               curr_fp);
588                         rc = -EPERM;
589                         break;
590                 }
591         }
592         read_unlock(&curr_fp->f_ci->m_lock);
593
594         return rc;
595 }
596
597 bool is_asterisk(char *p)
598 {
599         return p && p[0] == '*';
600 }
601
602 int ksmbd_override_fsids(struct ksmbd_work *work)
603 {
604         struct ksmbd_session *sess = work->sess;
605         struct ksmbd_share_config *share = work->tcon->share_conf;
606         struct cred *cred;
607         struct group_info *gi;
608         unsigned int uid;
609         unsigned int gid;
610
611         uid = user_uid(sess->user);
612         gid = user_gid(sess->user);
613         if (share->force_uid != KSMBD_SHARE_INVALID_UID)
614                 uid = share->force_uid;
615         if (share->force_gid != KSMBD_SHARE_INVALID_GID)
616                 gid = share->force_gid;
617
618         cred = prepare_kernel_cred(NULL);
619         if (!cred)
620                 return -ENOMEM;
621
622         cred->fsuid = make_kuid(current_user_ns(), uid);
623         cred->fsgid = make_kgid(current_user_ns(), gid);
624
625         gi = groups_alloc(0);
626         if (!gi) {
627                 abort_creds(cred);
628                 return -ENOMEM;
629         }
630         set_groups(cred, gi);
631         put_group_info(gi);
632
633         if (!uid_eq(cred->fsuid, GLOBAL_ROOT_UID))
634                 cred->cap_effective = cap_drop_fs_set(cred->cap_effective);
635
636         WARN_ON(work->saved_cred);
637         work->saved_cred = override_creds(cred);
638         if (!work->saved_cred) {
639                 abort_creds(cred);
640                 return -EINVAL;
641         }
642         return 0;
643 }
644
645 void ksmbd_revert_fsids(struct ksmbd_work *work)
646 {
647         const struct cred *cred;
648
649         WARN_ON(!work->saved_cred);
650
651         cred = current_cred();
652         revert_creds(work->saved_cred);
653         put_cred(cred);
654         work->saved_cred = NULL;
655 }
656
657 __le32 smb_map_generic_desired_access(__le32 daccess)
658 {
659         if (daccess & FILE_GENERIC_READ_LE) {
660                 daccess |= cpu_to_le32(GENERIC_READ_FLAGS);
661                 daccess &= ~FILE_GENERIC_READ_LE;
662         }
663
664         if (daccess & FILE_GENERIC_WRITE_LE) {
665                 daccess |= cpu_to_le32(GENERIC_WRITE_FLAGS);
666                 daccess &= ~FILE_GENERIC_WRITE_LE;
667         }
668
669         if (daccess & FILE_GENERIC_EXECUTE_LE) {
670                 daccess |= cpu_to_le32(GENERIC_EXECUTE_FLAGS);
671                 daccess &= ~FILE_GENERIC_EXECUTE_LE;
672         }
673
674         if (daccess & FILE_GENERIC_ALL_LE) {
675                 daccess |= cpu_to_le32(GENERIC_ALL_FLAGS);
676                 daccess &= ~FILE_GENERIC_ALL_LE;
677         }
678
679         return daccess;
680 }