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 <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 */
  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;
 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
 180 static 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
 191 static 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
 200 static 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
 234 int 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
 259 static 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
 298 err_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  */
 310 static 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  */
 321 static 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  */
 342 static 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  */
 358 static 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  */
 378 static void set_smb1_rsp_status(struct ksmbd_work *work, __le32 err)
 379 {
 380         work->send_no_response = 1;
 381 }
 382
 383 static 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
 391 static int smb1_negotiate(struct ksmbd_work *work)
 392 {
 393         return ksmbd_smb_negotiate_common(work, SMB_COM_NEGOTIATE);
 394 }
 395
 396 static struct smb_version_cmds smb1_server_cmds[1] = {
 397         [SMB_COM_NEGOTIATE_EX]  = { .proc = smb1_negotiate, },
 398 };
 399
 400 static 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
 408 int 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
 425 int 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 user_namespace *user_ns = file_mnt_user_ns(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                                                     user_ns,
 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  */
 491 int 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
 560 static int __smb2_negotiate(struct ksmbd_conn *conn)
 561 {
 562         return (conn->dialect >= SMB20_PROT_ID &&
 563                 conn->dialect <= SMB311_PROT_ID);
 564 }
 565
 566 static 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
 583 int 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
 611 enum 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
 620 static 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
 629 static 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
 637 int 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
 727 bool is_asterisk(char *p)
 728 {
 729         return p && p[0] == '*';
 730 }
 731
 732 int 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(NULL);
 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
 775 void 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 }