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 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 rc = ksmbd_vfs_fill_dentry_attrs(work, 461 idmap, 462 dentry, 463 &ksmbd_kstat); 464 if (rc) 465 break; 466 467 rc = fn(conn, info_level, d_info, &ksmbd_kstat); 468 if (rc) 469 break; 470 if (d_info->out_buf_len <= 0) 471 break; 472 473 dir->dot_dotdot[i] = 1; 474 if (d_info->flags & SMB2_RETURN_SINGLE_ENTRY) { 475 d_info->out_buf_len = 0; 476 break; 477 } 478 } 479 } 480 481 return rc; 482 } 483 484 /** 485 * ksmbd_extract_shortname() - get shortname from long filename 486 * @conn: connection instance 487 * @longname: source long filename 488 * @shortname: destination short filename 489 * 490 * Return: shortname length or 0 when source long name is '.' or '..' 491 * TODO: Though this function comforms the restriction of 8.3 Filename spec, 492 * but the result is different with Windows 7's one. need to check. 493 */ 494 int ksmbd_extract_shortname(struct ksmbd_conn *conn, const char *longname, 495 char *shortname) 496 { 497 const char *p; 498 char base[9], extension[4]; 499 char out[13] = {0}; 500 int baselen = 0; 501 int extlen = 0, len = 0; 502 unsigned int csum = 0; 503 const unsigned char *ptr; 504 bool dot_present = true; 505 506 p = longname; 507 if ((*p == '.') || (!(strcmp(p, "..")))) { 508 /*no mangling required */ 509 return 0; 510 } 511 512 p = strrchr(longname, '.'); 513 if (p == longname) { /*name starts with a dot*/ 514 strscpy(extension, "___", strlen("___")); 515 } else { 516 if (p) { 517 p++; 518 while (*p && extlen < 3) { 519 if (*p != '.') 520 extension[extlen++] = toupper(*p); 521 p++; 522 } 523 extension[extlen] = '\0'; 524 } else { 525 dot_present = false; 526 } 527 } 528 529 p = longname; 530 if (*p == '.') { 531 p++; 532 longname++; 533 } 534 while (*p && (baselen < 5)) { 535 if (*p != '.') 536 base[baselen++] = toupper(*p); 537 p++; 538 } 539 540 base[baselen] = MAGIC_CHAR; 541 memcpy(out, base, baselen + 1); 542 543 ptr = longname; 544 len = strlen(longname); 545 for (; len > 0; len--, ptr++) 546 csum += *ptr; 547 548 csum = csum % (MANGLE_BASE * MANGLE_BASE); 549 out[baselen + 1] = mangle(csum / MANGLE_BASE); 550 out[baselen + 2] = mangle(csum); 551 out[baselen + 3] = PERIOD; 552 553 if (dot_present) 554 memcpy(out + baselen + 4, extension, 4); 555 else 556 out[baselen + 4] = '\0'; 557 smbConvertToUTF16((__le16 *)shortname, out, PATH_MAX, 558 conn->local_nls, 0); 559 len = strlen(out) * 2; 560 return len; 561 } 562 563 static int __smb2_negotiate(struct ksmbd_conn *conn) 564 { 565 return (conn->dialect >= SMB20_PROT_ID && 566 conn->dialect <= SMB311_PROT_ID); 567 } 568 569 static int smb_handle_negotiate(struct ksmbd_work *work) 570 { 571 struct smb_negotiate_rsp *neg_rsp = work->response_buf; 572 573 ksmbd_debug(SMB, "Unsupported SMB1 protocol\n"); 574 575 if (ksmbd_iov_pin_rsp(work, (void *)neg_rsp, 576 sizeof(struct smb_negotiate_rsp) - 4)) 577 return -ENOMEM; 578 579 neg_rsp->hdr.Status.CifsError = STATUS_SUCCESS; 580 neg_rsp->hdr.WordCount = 1; 581 neg_rsp->DialectIndex = cpu_to_le16(work->conn->dialect); 582 neg_rsp->ByteCount = 0; 583 return 0; 584 } 585 586 int ksmbd_smb_negotiate_common(struct ksmbd_work *work, unsigned int command) 587 { 588 struct ksmbd_conn *conn = work->conn; 589 int ret; 590 591 conn->dialect = 592 ksmbd_negotiate_smb_dialect(work->request_buf); 593 ksmbd_debug(SMB, "conn->dialect 0x%x\n", conn->dialect); 594 595 if (command == SMB2_NEGOTIATE_HE) { 596 ret = smb2_handle_negotiate(work); 597 return ret; 598 } 599 600 if (command == SMB_COM_NEGOTIATE) { 601 if (__smb2_negotiate(conn)) { 602 init_smb3_11_server(conn); 603 init_smb2_neg_rsp(work); 604 ksmbd_debug(SMB, "Upgrade to SMB2 negotiation\n"); 605 return 0; 606 } 607 return smb_handle_negotiate(work); 608 } 609 610 pr_err("Unknown SMB negotiation command: %u\n", command); 611 return -EINVAL; 612 } 613 614 enum SHARED_MODE_ERRORS { 615 SHARE_DELETE_ERROR, 616 SHARE_READ_ERROR, 617 SHARE_WRITE_ERROR, 618 FILE_READ_ERROR, 619 FILE_WRITE_ERROR, 620 FILE_DELETE_ERROR, 621 }; 622 623 static const char * const shared_mode_errors[] = { 624 "Current access mode does not permit SHARE_DELETE", 625 "Current access mode does not permit SHARE_READ", 626 "Current access mode does not permit SHARE_WRITE", 627 "Desired access mode does not permit FILE_READ", 628 "Desired access mode does not permit FILE_WRITE", 629 "Desired access mode does not permit FILE_DELETE", 630 }; 631 632 static void smb_shared_mode_error(int error, struct ksmbd_file *prev_fp, 633 struct ksmbd_file *curr_fp) 634 { 635 ksmbd_debug(SMB, "%s\n", shared_mode_errors[error]); 636 ksmbd_debug(SMB, "Current mode: 0x%x Desired mode: 0x%x\n", 637 prev_fp->saccess, curr_fp->daccess); 638 } 639 640 int ksmbd_smb_check_shared_mode(struct file *filp, struct ksmbd_file *curr_fp) 641 { 642 int rc = 0; 643 struct ksmbd_file *prev_fp; 644 645 /* 646 * Lookup fp in master fp list, and check desired access and 647 * shared mode between previous open and current open. 648 */ 649 down_read(&curr_fp->f_ci->m_lock); 650 list_for_each_entry(prev_fp, &curr_fp->f_ci->m_fp_list, node) { 651 if (file_inode(filp) != file_inode(prev_fp->filp)) 652 continue; 653 654 if (filp == prev_fp->filp) 655 continue; 656 657 if (ksmbd_stream_fd(prev_fp) && ksmbd_stream_fd(curr_fp)) 658 if (strcmp(prev_fp->stream.name, curr_fp->stream.name)) 659 continue; 660 661 if (prev_fp->attrib_only != curr_fp->attrib_only) 662 continue; 663 664 if (!(prev_fp->saccess & FILE_SHARE_DELETE_LE) && 665 curr_fp->daccess & FILE_DELETE_LE) { 666 smb_shared_mode_error(SHARE_DELETE_ERROR, 667 prev_fp, 668 curr_fp); 669 rc = -EPERM; 670 break; 671 } 672 673 /* 674 * Only check FILE_SHARE_DELETE if stream opened and 675 * normal file opened. 676 */ 677 if (ksmbd_stream_fd(prev_fp) && !ksmbd_stream_fd(curr_fp)) 678 continue; 679 680 if (!(prev_fp->saccess & FILE_SHARE_READ_LE) && 681 curr_fp->daccess & (FILE_EXECUTE_LE | FILE_READ_DATA_LE)) { 682 smb_shared_mode_error(SHARE_READ_ERROR, 683 prev_fp, 684 curr_fp); 685 rc = -EPERM; 686 break; 687 } 688 689 if (!(prev_fp->saccess & FILE_SHARE_WRITE_LE) && 690 curr_fp->daccess & (FILE_WRITE_DATA_LE | FILE_APPEND_DATA_LE)) { 691 smb_shared_mode_error(SHARE_WRITE_ERROR, 692 prev_fp, 693 curr_fp); 694 rc = -EPERM; 695 break; 696 } 697 698 if (prev_fp->daccess & (FILE_EXECUTE_LE | FILE_READ_DATA_LE) && 699 !(curr_fp->saccess & FILE_SHARE_READ_LE)) { 700 smb_shared_mode_error(FILE_READ_ERROR, 701 prev_fp, 702 curr_fp); 703 rc = -EPERM; 704 break; 705 } 706 707 if (prev_fp->daccess & (FILE_WRITE_DATA_LE | FILE_APPEND_DATA_LE) && 708 !(curr_fp->saccess & FILE_SHARE_WRITE_LE)) { 709 smb_shared_mode_error(FILE_WRITE_ERROR, 710 prev_fp, 711 curr_fp); 712 rc = -EPERM; 713 break; 714 } 715 716 if (prev_fp->daccess & FILE_DELETE_LE && 717 !(curr_fp->saccess & FILE_SHARE_DELETE_LE)) { 718 smb_shared_mode_error(FILE_DELETE_ERROR, 719 prev_fp, 720 curr_fp); 721 rc = -EPERM; 722 break; 723 } 724 } 725 up_read(&curr_fp->f_ci->m_lock); 726 727 return rc; 728 } 729 730 bool is_asterisk(char *p) 731 { 732 return p && p[0] == '*'; 733 } 734 735 int __ksmbd_override_fsids(struct ksmbd_work *work, 736 struct ksmbd_share_config *share) 737 { 738 struct ksmbd_session *sess = work->sess; 739 struct cred *cred; 740 struct group_info *gi; 741 unsigned int uid; 742 unsigned int gid; 743 744 uid = user_uid(sess->user); 745 gid = user_gid(sess->user); 746 if (share->force_uid != KSMBD_SHARE_INVALID_UID) 747 uid = share->force_uid; 748 if (share->force_gid != KSMBD_SHARE_INVALID_GID) 749 gid = share->force_gid; 750 751 cred = prepare_kernel_cred(&init_task); 752 if (!cred) 753 return -ENOMEM; 754 755 cred->fsuid = make_kuid(&init_user_ns, uid); 756 cred->fsgid = make_kgid(&init_user_ns, gid); 757 758 gi = groups_alloc(0); 759 if (!gi) { 760 abort_creds(cred); 761 return -ENOMEM; 762 } 763 set_groups(cred, gi); 764 put_group_info(gi); 765 766 if (!uid_eq(cred->fsuid, GLOBAL_ROOT_UID)) 767 cred->cap_effective = cap_drop_fs_set(cred->cap_effective); 768 769 WARN_ON(work->saved_cred); 770 work->saved_cred = override_creds(cred); 771 if (!work->saved_cred) { 772 abort_creds(cred); 773 return -EINVAL; 774 } 775 return 0; 776 } 777 778 int ksmbd_override_fsids(struct ksmbd_work *work) 779 { 780 return __ksmbd_override_fsids(work, work->tcon->share_conf); 781 } 782 783 void ksmbd_revert_fsids(struct ksmbd_work *work) 784 { 785 const struct cred *cred; 786 787 WARN_ON(!work->saved_cred); 788 789 cred = current_cred(); 790 revert_creds(work->saved_cred); 791 put_cred(cred); 792 work->saved_cred = NULL; 793 } 794 795 __le32 smb_map_generic_desired_access(__le32 daccess) 796 { 797 if (daccess & FILE_GENERIC_READ_LE) { 798 daccess |= cpu_to_le32(GENERIC_READ_FLAGS); 799 daccess &= ~FILE_GENERIC_READ_LE; 800 } 801 802 if (daccess & FILE_GENERIC_WRITE_LE) { 803 daccess |= cpu_to_le32(GENERIC_WRITE_FLAGS); 804 daccess &= ~FILE_GENERIC_WRITE_LE; 805 } 806 807 if (daccess & FILE_GENERIC_EXECUTE_LE) { 808 daccess |= cpu_to_le32(GENERIC_EXECUTE_FLAGS); 809 daccess &= ~FILE_GENERIC_EXECUTE_LE; 810 } 811 812 if (daccess & FILE_GENERIC_ALL_LE) { 813 daccess |= cpu_to_le32(GENERIC_ALL_FLAGS); 814 daccess &= ~FILE_GENERIC_ALL_LE; 815 } 816 817 return daccess; 818 } 819