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