1 // SPDX-License-Identifier: LGPL-2.1 2 /* 3 * 4 * Copyright (C) International Business Machines Corp., 2002,2008 5 * Author(s): Steve French (sfrench@us.ibm.com) 6 * 7 */ 8 9 #include <linux/slab.h> 10 #include <linux/ctype.h> 11 #include <linux/mempool.h> 12 #include <linux/vmalloc.h> 13 #include "cifspdu.h" 14 #include "cifsglob.h" 15 #include "cifsproto.h" 16 #include "cifs_debug.h" 17 #include "smberr.h" 18 #include "nterr.h" 19 #include "cifs_unicode.h" 20 #include "smb2pdu.h" 21 #include "smb2proto.h" 22 #include "cifsfs.h" 23 #ifdef CONFIG_CIFS_DFS_UPCALL 24 #include "dns_resolve.h" 25 #include "dfs_cache.h" 26 #include "dfs.h" 27 #endif 28 #include "fs_context.h" 29 #include "cached_dir.h" 30 31 /* The xid serves as a useful identifier for each incoming vfs request, 32 in a similar way to the mid which is useful to track each sent smb, 33 and CurrentXid can also provide a running counter (although it 34 will eventually wrap past zero) of the total vfs operations handled 35 since the cifs fs was mounted */ 36 37 unsigned int 38 _get_xid(void) 39 { 40 unsigned int xid; 41 42 spin_lock(&GlobalMid_Lock); 43 GlobalTotalActiveXid++; 44 45 /* keep high water mark for number of simultaneous ops in filesystem */ 46 if (GlobalTotalActiveXid > GlobalMaxActiveXid) 47 GlobalMaxActiveXid = GlobalTotalActiveXid; 48 if (GlobalTotalActiveXid > 65000) 49 cifs_dbg(FYI, "warning: more than 65000 requests active\n"); 50 xid = GlobalCurrentXid++; 51 spin_unlock(&GlobalMid_Lock); 52 return xid; 53 } 54 55 void 56 _free_xid(unsigned int xid) 57 { 58 spin_lock(&GlobalMid_Lock); 59 /* if (GlobalTotalActiveXid == 0) 60 BUG(); */ 61 GlobalTotalActiveXid--; 62 spin_unlock(&GlobalMid_Lock); 63 } 64 65 struct cifs_ses * 66 sesInfoAlloc(void) 67 { 68 struct cifs_ses *ret_buf; 69 70 ret_buf = kzalloc(sizeof(struct cifs_ses), GFP_KERNEL); 71 if (ret_buf) { 72 atomic_inc(&sesInfoAllocCount); 73 spin_lock_init(&ret_buf->ses_lock); 74 ret_buf->ses_status = SES_NEW; 75 ++ret_buf->ses_count; 76 INIT_LIST_HEAD(&ret_buf->smb_ses_list); 77 INIT_LIST_HEAD(&ret_buf->tcon_list); 78 mutex_init(&ret_buf->session_mutex); 79 spin_lock_init(&ret_buf->iface_lock); 80 INIT_LIST_HEAD(&ret_buf->iface_list); 81 spin_lock_init(&ret_buf->chan_lock); 82 } 83 return ret_buf; 84 } 85 86 void 87 sesInfoFree(struct cifs_ses *buf_to_free) 88 { 89 struct cifs_server_iface *iface = NULL, *niface = NULL; 90 91 if (buf_to_free == NULL) { 92 cifs_dbg(FYI, "Null buffer passed to sesInfoFree\n"); 93 return; 94 } 95 96 unload_nls(buf_to_free->local_nls); 97 atomic_dec(&sesInfoAllocCount); 98 kfree(buf_to_free->serverOS); 99 kfree(buf_to_free->serverDomain); 100 kfree(buf_to_free->serverNOS); 101 kfree_sensitive(buf_to_free->password); 102 kfree_sensitive(buf_to_free->password2); 103 kfree(buf_to_free->user_name); 104 kfree(buf_to_free->domainName); 105 kfree(buf_to_free->dns_dom); 106 kfree_sensitive(buf_to_free->auth_key.response); 107 spin_lock(&buf_to_free->iface_lock); 108 list_for_each_entry_safe(iface, niface, &buf_to_free->iface_list, 109 iface_head) 110 kref_put(&iface->refcount, release_iface); 111 spin_unlock(&buf_to_free->iface_lock); 112 kfree_sensitive(buf_to_free); 113 } 114 115 struct cifs_tcon * 116 tcon_info_alloc(bool dir_leases_enabled, enum smb3_tcon_ref_trace trace) 117 { 118 struct cifs_tcon *ret_buf; 119 static atomic_t tcon_debug_id; 120 121 ret_buf = kzalloc(sizeof(*ret_buf), GFP_KERNEL); 122 if (!ret_buf) 123 return NULL; 124 125 if (dir_leases_enabled == true) { 126 ret_buf->cfids = init_cached_dirs(); 127 if (!ret_buf->cfids) { 128 kfree(ret_buf); 129 return NULL; 130 } 131 } 132 /* else ret_buf->cfids is already set to NULL above */ 133 134 atomic_inc(&tconInfoAllocCount); 135 ret_buf->status = TID_NEW; 136 ret_buf->debug_id = atomic_inc_return(&tcon_debug_id); 137 ret_buf->tc_count = 1; 138 spin_lock_init(&ret_buf->tc_lock); 139 INIT_LIST_HEAD(&ret_buf->openFileList); 140 INIT_LIST_HEAD(&ret_buf->tcon_list); 141 INIT_LIST_HEAD(&ret_buf->cifs_sb_list); 142 spin_lock_init(&ret_buf->open_file_lock); 143 spin_lock_init(&ret_buf->stat_lock); 144 spin_lock_init(&ret_buf->sb_list_lock); 145 atomic_set(&ret_buf->num_local_opens, 0); 146 atomic_set(&ret_buf->num_remote_opens, 0); 147 ret_buf->stats_from_time = ktime_get_real_seconds(); 148 #ifdef CONFIG_CIFS_FSCACHE 149 mutex_init(&ret_buf->fscache_lock); 150 #endif 151 trace_smb3_tcon_ref(ret_buf->debug_id, ret_buf->tc_count, trace); 152 #ifdef CONFIG_CIFS_DFS_UPCALL 153 INIT_LIST_HEAD(&ret_buf->dfs_ses_list); 154 #endif 155 INIT_LIST_HEAD(&ret_buf->pending_opens); 156 INIT_DELAYED_WORK(&ret_buf->query_interfaces, 157 smb2_query_server_interfaces); 158 #ifdef CONFIG_CIFS_DFS_UPCALL 159 INIT_DELAYED_WORK(&ret_buf->dfs_cache_work, dfs_cache_refresh); 160 #endif 161 162 return ret_buf; 163 } 164 165 void 166 tconInfoFree(struct cifs_tcon *tcon, enum smb3_tcon_ref_trace trace) 167 { 168 if (tcon == NULL) { 169 cifs_dbg(FYI, "Null buffer passed to tconInfoFree\n"); 170 return; 171 } 172 trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count, trace); 173 free_cached_dirs(tcon->cfids); 174 atomic_dec(&tconInfoAllocCount); 175 kfree(tcon->nativeFileSystem); 176 kfree_sensitive(tcon->password); 177 kfree(tcon->origin_fullpath); 178 kfree(tcon); 179 } 180 181 struct smb_hdr * 182 cifs_buf_get(void) 183 { 184 struct smb_hdr *ret_buf = NULL; 185 /* 186 * SMB2 header is bigger than CIFS one - no problems to clean some 187 * more bytes for CIFS. 188 */ 189 size_t buf_size = sizeof(struct smb2_hdr); 190 191 /* 192 * We could use negotiated size instead of max_msgsize - 193 * but it may be more efficient to always alloc same size 194 * albeit slightly larger than necessary and maxbuffersize 195 * defaults to this and can not be bigger. 196 */ 197 ret_buf = mempool_alloc(cifs_req_poolp, GFP_NOFS); 198 199 /* clear the first few header bytes */ 200 /* for most paths, more is cleared in header_assemble */ 201 memset(ret_buf, 0, buf_size + 3); 202 atomic_inc(&buf_alloc_count); 203 #ifdef CONFIG_CIFS_STATS2 204 atomic_inc(&total_buf_alloc_count); 205 #endif /* CONFIG_CIFS_STATS2 */ 206 207 return ret_buf; 208 } 209 210 void 211 cifs_buf_release(void *buf_to_free) 212 { 213 if (buf_to_free == NULL) { 214 /* cifs_dbg(FYI, "Null buffer passed to cifs_buf_release\n");*/ 215 return; 216 } 217 mempool_free(buf_to_free, cifs_req_poolp); 218 219 atomic_dec(&buf_alloc_count); 220 return; 221 } 222 223 struct smb_hdr * 224 cifs_small_buf_get(void) 225 { 226 struct smb_hdr *ret_buf = NULL; 227 228 /* We could use negotiated size instead of max_msgsize - 229 but it may be more efficient to always alloc same size 230 albeit slightly larger than necessary and maxbuffersize 231 defaults to this and can not be bigger */ 232 ret_buf = mempool_alloc(cifs_sm_req_poolp, GFP_NOFS); 233 /* No need to clear memory here, cleared in header assemble */ 234 /* memset(ret_buf, 0, sizeof(struct smb_hdr) + 27);*/ 235 atomic_inc(&small_buf_alloc_count); 236 #ifdef CONFIG_CIFS_STATS2 237 atomic_inc(&total_small_buf_alloc_count); 238 #endif /* CONFIG_CIFS_STATS2 */ 239 240 return ret_buf; 241 } 242 243 void 244 cifs_small_buf_release(void *buf_to_free) 245 { 246 247 if (buf_to_free == NULL) { 248 cifs_dbg(FYI, "Null buffer passed to cifs_small_buf_release\n"); 249 return; 250 } 251 mempool_free(buf_to_free, cifs_sm_req_poolp); 252 253 atomic_dec(&small_buf_alloc_count); 254 return; 255 } 256 257 void 258 free_rsp_buf(int resp_buftype, void *rsp) 259 { 260 if (resp_buftype == CIFS_SMALL_BUFFER) 261 cifs_small_buf_release(rsp); 262 else if (resp_buftype == CIFS_LARGE_BUFFER) 263 cifs_buf_release(rsp); 264 } 265 266 /* NB: MID can not be set if treeCon not passed in, in that 267 case it is responsibility of caller to set the mid */ 268 unsigned int 269 header_assemble(struct smb_hdr *buffer, char smb_command, 270 const struct cifs_tcon *treeCon, int word_count 271 /* length of fixed section (word count) in two byte units */) 272 { 273 unsigned int in_len; 274 char *temp = (char *) buffer; 275 276 memset(temp, 0, 256); /* bigger than MAX_CIFS_HDR_SIZE */ 277 278 in_len = (2 * word_count) + sizeof(struct smb_hdr) + 279 2 /* for bcc field itself */; 280 281 buffer->Protocol[0] = 0xFF; 282 buffer->Protocol[1] = 'S'; 283 buffer->Protocol[2] = 'M'; 284 buffer->Protocol[3] = 'B'; 285 buffer->Command = smb_command; 286 buffer->Flags = 0x00; /* case sensitive */ 287 buffer->Flags2 = SMBFLG2_KNOWS_LONG_NAMES; 288 buffer->Pid = cpu_to_le16((__u16)current->tgid); 289 buffer->PidHigh = cpu_to_le16((__u16)(current->tgid >> 16)); 290 if (treeCon) { 291 buffer->Tid = treeCon->tid; 292 if (treeCon->ses) { 293 if (treeCon->ses->capabilities & CAP_UNICODE) 294 buffer->Flags2 |= SMBFLG2_UNICODE; 295 if (treeCon->ses->capabilities & CAP_STATUS32) 296 buffer->Flags2 |= SMBFLG2_ERR_STATUS; 297 298 /* Uid is not converted */ 299 buffer->Uid = treeCon->ses->Suid; 300 if (treeCon->ses->server) 301 buffer->Mid = get_next_mid(treeCon->ses->server); 302 } 303 if (treeCon->Flags & SMB_SHARE_IS_IN_DFS) 304 buffer->Flags2 |= SMBFLG2_DFS; 305 if (treeCon->nocase) 306 buffer->Flags |= SMBFLG_CASELESS; 307 if ((treeCon->ses) && (treeCon->ses->server)) 308 if (treeCon->ses->server->sign) 309 buffer->Flags2 |= SMBFLG2_SECURITY_SIGNATURE; 310 } 311 312 /* endian conversion of flags is now done just before sending */ 313 buffer->WordCount = (char) word_count; 314 return in_len; 315 } 316 317 static int 318 check_smb_hdr(struct smb_hdr *smb) 319 { 320 /* does it have the right SMB "signature" ? */ 321 if (*(__le32 *) smb->Protocol != SMB1_PROTO_NUMBER) { 322 cifs_dbg(VFS, "Bad protocol string signature header 0x%x\n", 323 *(unsigned int *)smb->Protocol); 324 return 1; 325 } 326 327 /* if it's a response then accept */ 328 if (smb->Flags & SMBFLG_RESPONSE) 329 return 0; 330 331 /* only one valid case where server sends us request */ 332 if (smb->Command == SMB_COM_LOCKING_ANDX) 333 return 0; 334 335 /* 336 * Windows NT server returns error resposne (e.g. STATUS_DELETE_PENDING 337 * or STATUS_OBJECT_NAME_NOT_FOUND or ERRDOS/ERRbadfile or any other) 338 * for some TRANS2 requests without the RESPONSE flag set in header. 339 */ 340 if (smb->Command == SMB_COM_TRANSACTION2 && smb->Status.CifsError != 0) 341 return 0; 342 343 cifs_dbg(VFS, "Server sent request, not response. mid=%u\n", 344 get_mid(smb)); 345 return 1; 346 } 347 348 int 349 checkSMB(char *buf, unsigned int pdu_len, unsigned int total_read, 350 struct TCP_Server_Info *server) 351 { 352 struct smb_hdr *smb = (struct smb_hdr *)buf; 353 __u32 rfclen = pdu_len; 354 __u32 clc_len; /* calculated length */ 355 cifs_dbg(FYI, "checkSMB Length: 0x%x, smb_buf_length: 0x%x\n", 356 total_read, rfclen); 357 358 /* is this frame too small to even get to a BCC? */ 359 if (total_read < 2 + sizeof(struct smb_hdr)) { 360 if ((total_read >= sizeof(struct smb_hdr) - 1) 361 && (smb->Status.CifsError != 0)) { 362 /* it's an error return */ 363 smb->WordCount = 0; 364 /* some error cases do not return wct and bcc */ 365 return 0; 366 } else if ((total_read == sizeof(struct smb_hdr) + 1) && 367 (smb->WordCount == 0)) { 368 char *tmp = (char *)smb; 369 /* Need to work around a bug in two servers here */ 370 /* First, check if the part of bcc they sent was zero */ 371 if (tmp[sizeof(struct smb_hdr)] == 0) { 372 /* some servers return only half of bcc 373 * on simple responses (wct, bcc both zero) 374 * in particular have seen this on 375 * ulogoffX and FindClose. This leaves 376 * one byte of bcc potentially uninitialized 377 */ 378 /* zero rest of bcc */ 379 tmp[sizeof(struct smb_hdr)+1] = 0; 380 return 0; 381 } 382 cifs_dbg(VFS, "rcvd invalid byte count (bcc)\n"); 383 return smb_EIO1(smb_eio_trace_rx_inv_bcc, tmp[sizeof(struct smb_hdr)]); 384 } else { 385 cifs_dbg(VFS, "Length less than smb header size\n"); 386 return smb_EIO2(smb_eio_trace_rx_too_short, 387 total_read, smb->WordCount); 388 } 389 } else if (total_read < sizeof(*smb) + 2 * smb->WordCount) { 390 cifs_dbg(VFS, "%s: can't read BCC due to invalid WordCount(%u)\n", 391 __func__, smb->WordCount); 392 return smb_EIO2(smb_eio_trace_rx_check_rsp, 393 total_read, 2 + sizeof(struct smb_hdr)); 394 } 395 396 /* otherwise, there is enough to get to the BCC */ 397 if (check_smb_hdr(smb)) 398 return smb_EIO1(smb_eio_trace_rx_rfc1002_magic, *(u32 *)smb->Protocol); 399 clc_len = smbCalcSize(smb); 400 401 if (rfclen != total_read) { 402 cifs_dbg(VFS, "Length read does not match RFC1001 length %d/%d\n", 403 rfclen, total_read); 404 return smb_EIO2(smb_eio_trace_rx_check_rsp, 405 total_read, rfclen); 406 } 407 408 if (rfclen != clc_len) { 409 __u16 mid = get_mid(smb); 410 /* check if bcc wrapped around for large read responses */ 411 if ((rfclen > 64 * 1024) && (rfclen > clc_len)) { 412 /* check if lengths match mod 64K */ 413 if (((rfclen) & 0xFFFF) == (clc_len & 0xFFFF)) 414 return 0; /* bcc wrapped */ 415 } 416 cifs_dbg(FYI, "Calculated size %u vs length %u mismatch for mid=%u\n", 417 clc_len, rfclen, mid); 418 419 if (rfclen < clc_len) { 420 cifs_dbg(VFS, "RFC1001 size %u smaller than SMB for mid=%u\n", 421 rfclen, mid); 422 return smb_EIO2(smb_eio_trace_rx_calc_len_too_big, 423 rfclen, clc_len); 424 } else if (rfclen > clc_len + 512) { 425 /* 426 * Some servers (Windows XP in particular) send more 427 * data than the lengths in the SMB packet would 428 * indicate on certain calls (byte range locks and 429 * trans2 find first calls in particular). While the 430 * client can handle such a frame by ignoring the 431 * trailing data, we choose limit the amount of extra 432 * data to 512 bytes. 433 */ 434 cifs_dbg(VFS, "RFC1001 size %u more than 512 bytes larger than SMB for mid=%u\n", 435 rfclen, mid); 436 return smb_EIO2(smb_eio_trace_rx_overlong, 437 rfclen, clc_len + 512); 438 } 439 } 440 return 0; 441 } 442 443 bool 444 is_valid_oplock_break(char *buffer, struct TCP_Server_Info *srv) 445 { 446 struct smb_hdr *buf = (struct smb_hdr *)buffer; 447 struct smb_com_lock_req *pSMB = (struct smb_com_lock_req *)buf; 448 struct TCP_Server_Info *pserver; 449 struct cifs_ses *ses; 450 struct cifs_tcon *tcon; 451 struct cifsInodeInfo *pCifsInode; 452 struct cifsFileInfo *netfile; 453 454 cifs_dbg(FYI, "Checking for oplock break or dnotify response\n"); 455 if ((pSMB->hdr.Command == SMB_COM_NT_TRANSACT) && 456 (pSMB->hdr.Flags & SMBFLG_RESPONSE)) { 457 struct smb_com_transaction_change_notify_rsp *pSMBr = 458 (struct smb_com_transaction_change_notify_rsp *)buf; 459 struct file_notify_information *pnotify; 460 __u32 data_offset = 0; 461 size_t len = srv->total_read - srv->pdu_size; 462 463 if (get_bcc(buf) > sizeof(struct file_notify_information)) { 464 data_offset = le32_to_cpu(pSMBr->DataOffset); 465 466 if (data_offset > 467 len - sizeof(struct file_notify_information)) { 468 cifs_dbg(FYI, "Invalid data_offset %u\n", 469 data_offset); 470 return true; 471 } 472 pnotify = (struct file_notify_information *) 473 ((char *)&pSMBr->hdr.Protocol + data_offset); 474 cifs_dbg(FYI, "dnotify on %s Action: 0x%x\n", 475 pnotify->FileName, pnotify->Action); 476 /* cifs_dump_mem("Rcvd notify Data: ",buf, 477 sizeof(struct smb_hdr)+60); */ 478 return true; 479 } 480 if (pSMBr->hdr.Status.CifsError) { 481 cifs_dbg(FYI, "notify err 0x%x\n", 482 pSMBr->hdr.Status.CifsError); 483 return true; 484 } 485 return false; 486 } 487 if (pSMB->hdr.Command != SMB_COM_LOCKING_ANDX) 488 return false; 489 if (pSMB->hdr.Flags & SMBFLG_RESPONSE) { 490 /* no sense logging error on invalid handle on oplock 491 break - harmless race between close request and oplock 492 break response is expected from time to time writing out 493 large dirty files cached on the client */ 494 if ((NT_STATUS_INVALID_HANDLE) == 495 le32_to_cpu(pSMB->hdr.Status.CifsError)) { 496 cifs_dbg(FYI, "Invalid handle on oplock break\n"); 497 return true; 498 } else if (ERRbadfid == 499 le16_to_cpu(pSMB->hdr.Status.DosError.Error)) { 500 return true; 501 } else { 502 return false; /* on valid oplock brk we get "request" */ 503 } 504 } 505 if (pSMB->hdr.WordCount != 8) 506 return false; 507 508 cifs_dbg(FYI, "oplock type 0x%x level 0x%x\n", 509 pSMB->LockType, pSMB->OplockLevel); 510 if (!(pSMB->LockType & LOCKING_ANDX_OPLOCK_RELEASE)) 511 return false; 512 513 /* If server is a channel, select the primary channel */ 514 pserver = SERVER_IS_CHAN(srv) ? srv->primary_server : srv; 515 516 /* look up tcon based on tid & uid */ 517 spin_lock(&cifs_tcp_ses_lock); 518 list_for_each_entry(ses, &pserver->smb_ses_list, smb_ses_list) { 519 if (cifs_ses_exiting(ses)) 520 continue; 521 list_for_each_entry(tcon, &ses->tcon_list, tcon_list) { 522 if (tcon->tid != buf->Tid) 523 continue; 524 525 cifs_stats_inc(&tcon->stats.cifs_stats.num_oplock_brks); 526 spin_lock(&tcon->open_file_lock); 527 list_for_each_entry(netfile, &tcon->openFileList, tlist) { 528 if (pSMB->Fid != netfile->fid.netfid) 529 continue; 530 531 cifs_dbg(FYI, "file id match, oplock break\n"); 532 pCifsInode = CIFS_I(d_inode(netfile->dentry)); 533 534 set_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, 535 &pCifsInode->flags); 536 537 netfile->oplock_epoch = 0; 538 netfile->oplock_level = pSMB->OplockLevel; 539 netfile->oplock_break_cancelled = false; 540 cifs_queue_oplock_break(netfile); 541 542 spin_unlock(&tcon->open_file_lock); 543 spin_unlock(&cifs_tcp_ses_lock); 544 return true; 545 } 546 spin_unlock(&tcon->open_file_lock); 547 spin_unlock(&cifs_tcp_ses_lock); 548 cifs_dbg(FYI, "No matching file for oplock break\n"); 549 return true; 550 } 551 } 552 spin_unlock(&cifs_tcp_ses_lock); 553 cifs_dbg(FYI, "Can not process oplock break for non-existent connection\n"); 554 return true; 555 } 556 557 void 558 dump_smb(void *buf, int smb_buf_length) 559 { 560 if (traceSMB == 0) 561 return; 562 563 print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_NONE, 8, 2, buf, 564 smb_buf_length, true); 565 } 566 567 void 568 cifs_autodisable_serverino(struct cifs_sb_info *cifs_sb) 569 { 570 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) { 571 struct cifs_tcon *tcon = NULL; 572 573 if (cifs_sb->master_tlink) 574 tcon = cifs_sb_master_tcon(cifs_sb); 575 576 cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM; 577 cifs_sb->mnt_cifs_serverino_autodisabled = true; 578 cifs_dbg(VFS, "Autodisabling the use of server inode numbers on %s\n", 579 tcon ? tcon->tree_name : "new server"); 580 cifs_dbg(VFS, "The server doesn't seem to support them properly or the files might be on different servers (DFS)\n"); 581 cifs_dbg(VFS, "Hardlinks will not be recognized on this mount. Consider mounting with the \"noserverino\" option to silence this message.\n"); 582 583 } 584 } 585 586 void cifs_set_oplock_level(struct cifsInodeInfo *cinode, __u32 oplock) 587 { 588 oplock &= 0xF; 589 590 if (oplock == OPLOCK_EXCLUSIVE) { 591 cinode->oplock = CIFS_CACHE_WRITE_FLG | CIFS_CACHE_READ_FLG; 592 cifs_dbg(FYI, "Exclusive Oplock granted on inode %p\n", 593 &cinode->netfs.inode); 594 } else if (oplock == OPLOCK_READ) { 595 cinode->oplock = CIFS_CACHE_READ_FLG; 596 cifs_dbg(FYI, "Level II Oplock granted on inode %p\n", 597 &cinode->netfs.inode); 598 } else 599 cinode->oplock = 0; 600 } 601 602 /* 603 * We wait for oplock breaks to be processed before we attempt to perform 604 * writes. 605 */ 606 int cifs_get_writer(struct cifsInodeInfo *cinode) 607 { 608 int rc; 609 610 start: 611 rc = wait_on_bit(&cinode->flags, CIFS_INODE_PENDING_OPLOCK_BREAK, 612 TASK_KILLABLE); 613 if (rc) 614 return rc; 615 616 spin_lock(&cinode->writers_lock); 617 if (!cinode->writers) 618 set_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags); 619 cinode->writers++; 620 /* Check to see if we have started servicing an oplock break */ 621 if (test_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, &cinode->flags)) { 622 cinode->writers--; 623 if (cinode->writers == 0) { 624 clear_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags); 625 wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_WRITERS); 626 } 627 spin_unlock(&cinode->writers_lock); 628 goto start; 629 } 630 spin_unlock(&cinode->writers_lock); 631 return 0; 632 } 633 634 void cifs_put_writer(struct cifsInodeInfo *cinode) 635 { 636 spin_lock(&cinode->writers_lock); 637 cinode->writers--; 638 if (cinode->writers == 0) { 639 clear_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags); 640 wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_WRITERS); 641 } 642 spin_unlock(&cinode->writers_lock); 643 } 644 645 /** 646 * cifs_queue_oplock_break - queue the oplock break handler for cfile 647 * @cfile: The file to break the oplock on 648 * 649 * This function is called from the demultiplex thread when it 650 * receives an oplock break for @cfile. 651 * 652 * Assumes the tcon->open_file_lock is held. 653 * Assumes cfile->file_info_lock is NOT held. 654 */ 655 void cifs_queue_oplock_break(struct cifsFileInfo *cfile) 656 { 657 /* 658 * Bump the handle refcount now while we hold the 659 * open_file_lock to enforce the validity of it for the oplock 660 * break handler. The matching put is done at the end of the 661 * handler. 662 */ 663 cifsFileInfo_get(cfile); 664 665 queue_work(cifsoplockd_wq, &cfile->oplock_break); 666 } 667 668 void cifs_done_oplock_break(struct cifsInodeInfo *cinode) 669 { 670 clear_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, &cinode->flags); 671 wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_OPLOCK_BREAK); 672 } 673 674 bool 675 backup_cred(struct cifs_sb_info *cifs_sb) 676 { 677 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPUID) { 678 if (uid_eq(cifs_sb->ctx->backupuid, current_fsuid())) 679 return true; 680 } 681 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPGID) { 682 if (in_group_p(cifs_sb->ctx->backupgid)) 683 return true; 684 } 685 686 return false; 687 } 688 689 void 690 cifs_del_pending_open(struct cifs_pending_open *open) 691 { 692 spin_lock(&tlink_tcon(open->tlink)->open_file_lock); 693 list_del(&open->olist); 694 spin_unlock(&tlink_tcon(open->tlink)->open_file_lock); 695 } 696 697 void 698 cifs_add_pending_open_locked(struct cifs_fid *fid, struct tcon_link *tlink, 699 struct cifs_pending_open *open) 700 { 701 memcpy(open->lease_key, fid->lease_key, SMB2_LEASE_KEY_SIZE); 702 open->oplock = CIFS_OPLOCK_NO_CHANGE; 703 open->tlink = tlink; 704 fid->pending_open = open; 705 list_add_tail(&open->olist, &tlink_tcon(tlink)->pending_opens); 706 } 707 708 void 709 cifs_add_pending_open(struct cifs_fid *fid, struct tcon_link *tlink, 710 struct cifs_pending_open *open) 711 { 712 spin_lock(&tlink_tcon(tlink)->open_file_lock); 713 cifs_add_pending_open_locked(fid, tlink, open); 714 spin_unlock(&tlink_tcon(open->tlink)->open_file_lock); 715 } 716 717 /* 718 * Critical section which runs after acquiring deferred_lock. 719 * As there is no reference count on cifs_deferred_close, pdclose 720 * should not be used outside deferred_lock. 721 */ 722 bool 723 cifs_is_deferred_close(struct cifsFileInfo *cfile, struct cifs_deferred_close **pdclose) 724 { 725 struct cifs_deferred_close *dclose; 726 727 list_for_each_entry(dclose, &CIFS_I(d_inode(cfile->dentry))->deferred_closes, dlist) { 728 if ((dclose->netfid == cfile->fid.netfid) && 729 (dclose->persistent_fid == cfile->fid.persistent_fid) && 730 (dclose->volatile_fid == cfile->fid.volatile_fid)) { 731 *pdclose = dclose; 732 return true; 733 } 734 } 735 return false; 736 } 737 738 /* 739 * Critical section which runs after acquiring deferred_lock. 740 */ 741 void 742 cifs_add_deferred_close(struct cifsFileInfo *cfile, struct cifs_deferred_close *dclose) 743 { 744 bool is_deferred = false; 745 struct cifs_deferred_close *pdclose; 746 747 is_deferred = cifs_is_deferred_close(cfile, &pdclose); 748 if (is_deferred) { 749 kfree(dclose); 750 return; 751 } 752 753 dclose->tlink = cfile->tlink; 754 dclose->netfid = cfile->fid.netfid; 755 dclose->persistent_fid = cfile->fid.persistent_fid; 756 dclose->volatile_fid = cfile->fid.volatile_fid; 757 list_add_tail(&dclose->dlist, &CIFS_I(d_inode(cfile->dentry))->deferred_closes); 758 } 759 760 /* 761 * Critical section which runs after acquiring deferred_lock. 762 */ 763 void 764 cifs_del_deferred_close(struct cifsFileInfo *cfile) 765 { 766 bool is_deferred = false; 767 struct cifs_deferred_close *dclose; 768 769 is_deferred = cifs_is_deferred_close(cfile, &dclose); 770 if (!is_deferred) 771 return; 772 list_del(&dclose->dlist); 773 kfree(dclose); 774 } 775 776 void 777 cifs_close_deferred_file(struct cifsInodeInfo *cifs_inode) 778 { 779 struct cifsFileInfo *cfile = NULL; 780 struct file_list *tmp_list, *tmp_next_list; 781 LIST_HEAD(file_head); 782 783 if (cifs_inode == NULL) 784 return; 785 786 spin_lock(&cifs_inode->open_file_lock); 787 list_for_each_entry(cfile, &cifs_inode->openFileList, flist) { 788 if (delayed_work_pending(&cfile->deferred)) { 789 if (cancel_delayed_work(&cfile->deferred)) { 790 spin_lock(&cifs_inode->deferred_lock); 791 cifs_del_deferred_close(cfile); 792 spin_unlock(&cifs_inode->deferred_lock); 793 794 tmp_list = kmalloc(sizeof(struct file_list), GFP_ATOMIC); 795 if (tmp_list == NULL) 796 break; 797 tmp_list->cfile = cfile; 798 list_add_tail(&tmp_list->list, &file_head); 799 } 800 } 801 } 802 spin_unlock(&cifs_inode->open_file_lock); 803 804 list_for_each_entry_safe(tmp_list, tmp_next_list, &file_head, list) { 805 _cifsFileInfo_put(tmp_list->cfile, false, false); 806 list_del(&tmp_list->list); 807 kfree(tmp_list); 808 } 809 } 810 811 void 812 cifs_close_all_deferred_files(struct cifs_tcon *tcon) 813 { 814 struct cifsFileInfo *cfile; 815 struct file_list *tmp_list, *tmp_next_list; 816 LIST_HEAD(file_head); 817 818 spin_lock(&tcon->open_file_lock); 819 list_for_each_entry(cfile, &tcon->openFileList, tlist) { 820 if (delayed_work_pending(&cfile->deferred)) { 821 if (cancel_delayed_work(&cfile->deferred)) { 822 spin_lock(&CIFS_I(d_inode(cfile->dentry))->deferred_lock); 823 cifs_del_deferred_close(cfile); 824 spin_unlock(&CIFS_I(d_inode(cfile->dentry))->deferred_lock); 825 826 tmp_list = kmalloc(sizeof(struct file_list), GFP_ATOMIC); 827 if (tmp_list == NULL) 828 break; 829 tmp_list->cfile = cfile; 830 list_add_tail(&tmp_list->list, &file_head); 831 } 832 } 833 } 834 spin_unlock(&tcon->open_file_lock); 835 836 list_for_each_entry_safe(tmp_list, tmp_next_list, &file_head, list) { 837 _cifsFileInfo_put(tmp_list->cfile, true, false); 838 list_del(&tmp_list->list); 839 kfree(tmp_list); 840 } 841 } 842 843 void cifs_close_deferred_file_under_dentry(struct cifs_tcon *tcon, 844 struct dentry *dentry) 845 { 846 struct file_list *tmp_list, *tmp_next_list; 847 struct cifsFileInfo *cfile; 848 LIST_HEAD(file_head); 849 850 spin_lock(&tcon->open_file_lock); 851 list_for_each_entry(cfile, &tcon->openFileList, tlist) { 852 if ((cfile->dentry == dentry) && 853 delayed_work_pending(&cfile->deferred) && 854 cancel_delayed_work(&cfile->deferred)) { 855 spin_lock(&CIFS_I(d_inode(cfile->dentry))->deferred_lock); 856 cifs_del_deferred_close(cfile); 857 spin_unlock(&CIFS_I(d_inode(cfile->dentry))->deferred_lock); 858 859 tmp_list = kmalloc(sizeof(struct file_list), GFP_ATOMIC); 860 if (tmp_list == NULL) 861 break; 862 tmp_list->cfile = cfile; 863 list_add_tail(&tmp_list->list, &file_head); 864 } 865 } 866 spin_unlock(&tcon->open_file_lock); 867 868 list_for_each_entry_safe(tmp_list, tmp_next_list, &file_head, list) { 869 _cifsFileInfo_put(tmp_list->cfile, true, false); 870 list_del(&tmp_list->list); 871 kfree(tmp_list); 872 } 873 } 874 875 /* 876 * If a dentry has been deleted, all corresponding open handles should know that 877 * so that we do not defer close them. 878 */ 879 void cifs_mark_open_handles_for_deleted_file(struct inode *inode, 880 const char *path) 881 { 882 struct cifsFileInfo *cfile; 883 void *page; 884 const char *full_path; 885 struct cifsInodeInfo *cinode = CIFS_I(inode); 886 887 page = alloc_dentry_path(); 888 spin_lock(&cinode->open_file_lock); 889 890 /* 891 * note: we need to construct path from dentry and compare only if the 892 * inode has any hardlinks. When number of hardlinks is 1, we can just 893 * mark all open handles since they are going to be from the same file. 894 */ 895 if (inode->i_nlink > 1) { 896 list_for_each_entry(cfile, &cinode->openFileList, flist) { 897 full_path = build_path_from_dentry(cfile->dentry, page); 898 if (!IS_ERR(full_path) && strcmp(full_path, path) == 0) 899 cfile->status_file_deleted = true; 900 } 901 } else { 902 list_for_each_entry(cfile, &cinode->openFileList, flist) 903 cfile->status_file_deleted = true; 904 } 905 spin_unlock(&cinode->open_file_lock); 906 free_dentry_path(page); 907 } 908 909 /* parses DFS referral V3 structure 910 * caller is responsible for freeing target_nodes 911 * returns: 912 * - on success - 0 913 * - on failure - errno 914 */ 915 int 916 parse_dfs_referrals(struct get_dfs_referral_rsp *rsp, u32 rsp_size, 917 unsigned int *num_of_nodes, 918 struct dfs_info3_param **target_nodes, 919 const struct nls_table *nls_codepage, int remap, 920 const char *searchName, bool is_unicode) 921 { 922 int i, rc = 0; 923 char *data_end; 924 struct dfs_referral_level_3 *ref; 925 926 if (rsp_size < sizeof(*rsp)) { 927 cifs_dbg(VFS | ONCE, 928 "%s: header is malformed (size is %u, must be %zu)\n", 929 __func__, rsp_size, sizeof(*rsp)); 930 rc = -EINVAL; 931 goto parse_DFS_referrals_exit; 932 } 933 934 *num_of_nodes = le16_to_cpu(rsp->NumberOfReferrals); 935 936 if (*num_of_nodes < 1) { 937 cifs_dbg(VFS | ONCE, "%s: [path=%s] num_referrals must be at least > 0, but we got %d\n", 938 __func__, searchName, *num_of_nodes); 939 rc = -ENOENT; 940 goto parse_DFS_referrals_exit; 941 } 942 943 if (sizeof(*rsp) + *num_of_nodes * sizeof(REFERRAL3) > rsp_size) { 944 cifs_dbg(VFS | ONCE, 945 "%s: malformed buffer (size is %u, must be at least %zu)\n", 946 __func__, rsp_size, 947 sizeof(*rsp) + *num_of_nodes * sizeof(REFERRAL3)); 948 rc = -EINVAL; 949 goto parse_DFS_referrals_exit; 950 } 951 952 ref = (struct dfs_referral_level_3 *) &(rsp->referrals); 953 if (ref->VersionNumber != cpu_to_le16(3)) { 954 cifs_dbg(VFS, "Referrals of V%d version are not supported, should be V3\n", 955 le16_to_cpu(ref->VersionNumber)); 956 rc = -EINVAL; 957 goto parse_DFS_referrals_exit; 958 } 959 960 /* get the upper boundary of the resp buffer */ 961 data_end = (char *)rsp + rsp_size; 962 963 cifs_dbg(FYI, "num_referrals: %d dfs flags: 0x%x ...\n", 964 *num_of_nodes, le32_to_cpu(rsp->DFSFlags)); 965 966 *target_nodes = kcalloc(*num_of_nodes, sizeof(struct dfs_info3_param), 967 GFP_KERNEL); 968 if (*target_nodes == NULL) { 969 rc = -ENOMEM; 970 goto parse_DFS_referrals_exit; 971 } 972 973 /* collect necessary data from referrals */ 974 for (i = 0; i < *num_of_nodes; i++) { 975 char *temp; 976 int max_len; 977 struct dfs_info3_param *node = (*target_nodes)+i; 978 979 node->flags = le32_to_cpu(rsp->DFSFlags); 980 if (is_unicode) { 981 __le16 *tmp = kmalloc(strlen(searchName)*2 + 2, 982 GFP_KERNEL); 983 if (tmp == NULL) { 984 rc = -ENOMEM; 985 goto parse_DFS_referrals_exit; 986 } 987 cifsConvertToUTF16((__le16 *) tmp, searchName, 988 PATH_MAX, nls_codepage, remap); 989 node->path_consumed = cifs_utf16_bytes(tmp, 990 le16_to_cpu(rsp->PathConsumed), 991 nls_codepage); 992 kfree(tmp); 993 } else 994 node->path_consumed = le16_to_cpu(rsp->PathConsumed); 995 996 node->server_type = le16_to_cpu(ref->ServerType); 997 node->ref_flag = le16_to_cpu(ref->ReferralEntryFlags); 998 999 /* copy DfsPath */ 1000 temp = (char *)ref + le16_to_cpu(ref->DfsPathOffset); 1001 max_len = data_end - temp; 1002 node->path_name = cifs_strndup_from_utf16(temp, max_len, 1003 is_unicode, nls_codepage); 1004 if (!node->path_name) { 1005 rc = -ENOMEM; 1006 goto parse_DFS_referrals_exit; 1007 } 1008 1009 /* copy link target UNC */ 1010 temp = (char *)ref + le16_to_cpu(ref->NetworkAddressOffset); 1011 max_len = data_end - temp; 1012 node->node_name = cifs_strndup_from_utf16(temp, max_len, 1013 is_unicode, nls_codepage); 1014 if (!node->node_name) { 1015 rc = -ENOMEM; 1016 goto parse_DFS_referrals_exit; 1017 } 1018 1019 node->ttl = le32_to_cpu(ref->TimeToLive); 1020 1021 ref++; 1022 } 1023 1024 parse_DFS_referrals_exit: 1025 if (rc) { 1026 free_dfs_info_array(*target_nodes, *num_of_nodes); 1027 *target_nodes = NULL; 1028 *num_of_nodes = 0; 1029 } 1030 return rc; 1031 } 1032 1033 /** 1034 * cifs_alloc_hash - allocate hash and hash context together 1035 * @name: The name of the crypto hash algo 1036 * @sdesc: SHASH descriptor where to put the pointer to the hash TFM 1037 * 1038 * The caller has to make sure @sdesc is initialized to either NULL or 1039 * a valid context. It can be freed via cifs_free_hash(). 1040 */ 1041 int 1042 cifs_alloc_hash(const char *name, struct shash_desc **sdesc) 1043 { 1044 int rc = 0; 1045 struct crypto_shash *alg = NULL; 1046 1047 if (*sdesc) 1048 return 0; 1049 1050 alg = crypto_alloc_shash(name, 0, 0); 1051 if (IS_ERR(alg)) { 1052 cifs_dbg(VFS, "Could not allocate shash TFM '%s'\n", name); 1053 rc = PTR_ERR(alg); 1054 *sdesc = NULL; 1055 return rc; 1056 } 1057 1058 *sdesc = kmalloc(sizeof(struct shash_desc) + crypto_shash_descsize(alg), GFP_KERNEL); 1059 if (*sdesc == NULL) { 1060 cifs_dbg(VFS, "no memory left to allocate shash TFM '%s'\n", name); 1061 crypto_free_shash(alg); 1062 return -ENOMEM; 1063 } 1064 1065 (*sdesc)->tfm = alg; 1066 return 0; 1067 } 1068 1069 /** 1070 * cifs_free_hash - free hash and hash context together 1071 * @sdesc: Where to find the pointer to the hash TFM 1072 * 1073 * Freeing a NULL descriptor is safe. 1074 */ 1075 void 1076 cifs_free_hash(struct shash_desc **sdesc) 1077 { 1078 if (unlikely(!sdesc) || !*sdesc) 1079 return; 1080 1081 if ((*sdesc)->tfm) { 1082 crypto_free_shash((*sdesc)->tfm); 1083 (*sdesc)->tfm = NULL; 1084 } 1085 1086 kfree_sensitive(*sdesc); 1087 *sdesc = NULL; 1088 } 1089 1090 void extract_unc_hostname(const char *unc, const char **h, size_t *len) 1091 { 1092 const char *end; 1093 1094 /* skip initial slashes */ 1095 while (*unc && (*unc == '\\' || *unc == '/')) 1096 unc++; 1097 1098 end = unc; 1099 1100 while (*end && !(*end == '\\' || *end == '/')) 1101 end++; 1102 1103 *h = unc; 1104 *len = end - unc; 1105 } 1106 1107 /** 1108 * copy_path_name - copy src path to dst, possibly truncating 1109 * @dst: The destination buffer 1110 * @src: The source name 1111 * 1112 * returns number of bytes written (including trailing nul) 1113 */ 1114 int copy_path_name(char *dst, const char *src) 1115 { 1116 int name_len; 1117 1118 /* 1119 * PATH_MAX includes nul, so if strlen(src) >= PATH_MAX it 1120 * will truncate and strlen(dst) will be PATH_MAX-1 1121 */ 1122 name_len = strscpy(dst, src, PATH_MAX); 1123 if (WARN_ON_ONCE(name_len < 0)) 1124 name_len = PATH_MAX-1; 1125 1126 /* we count the trailing nul */ 1127 name_len++; 1128 return name_len; 1129 } 1130 1131 struct super_cb_data { 1132 void *data; 1133 struct super_block *sb; 1134 }; 1135 1136 static void tcon_super_cb(struct super_block *sb, void *arg) 1137 { 1138 struct super_cb_data *sd = arg; 1139 struct cifs_sb_info *cifs_sb; 1140 struct cifs_tcon *t1 = sd->data, *t2; 1141 1142 if (sd->sb) 1143 return; 1144 1145 cifs_sb = CIFS_SB(sb); 1146 t2 = cifs_sb_master_tcon(cifs_sb); 1147 1148 spin_lock(&t2->tc_lock); 1149 if ((t1->ses == t2->ses || 1150 t1->ses->dfs_root_ses == t2->ses->dfs_root_ses) && 1151 t1->ses->server == t2->ses->server && 1152 t2->origin_fullpath && 1153 dfs_src_pathname_equal(t2->origin_fullpath, t1->origin_fullpath)) 1154 sd->sb = sb; 1155 spin_unlock(&t2->tc_lock); 1156 } 1157 1158 static struct super_block *__cifs_get_super(void (*f)(struct super_block *, void *), 1159 void *data) 1160 { 1161 struct super_cb_data sd = { 1162 .data = data, 1163 .sb = NULL, 1164 }; 1165 struct file_system_type **fs_type = (struct file_system_type *[]) { 1166 &cifs_fs_type, &smb3_fs_type, NULL, 1167 }; 1168 1169 for (; *fs_type; fs_type++) { 1170 iterate_supers_type(*fs_type, f, &sd); 1171 if (sd.sb) { 1172 /* 1173 * Grab an active reference in order to prevent automounts (DFS links) 1174 * of expiring and then freeing up our cifs superblock pointer while 1175 * we're doing failover. 1176 */ 1177 cifs_sb_active(sd.sb); 1178 return sd.sb; 1179 } 1180 } 1181 pr_warn_once("%s: could not find dfs superblock\n", __func__); 1182 return ERR_PTR(-EINVAL); 1183 } 1184 1185 static void __cifs_put_super(struct super_block *sb) 1186 { 1187 if (!IS_ERR_OR_NULL(sb)) 1188 cifs_sb_deactive(sb); 1189 } 1190 1191 struct super_block *cifs_get_dfs_tcon_super(struct cifs_tcon *tcon) 1192 { 1193 spin_lock(&tcon->tc_lock); 1194 if (!tcon->origin_fullpath) { 1195 spin_unlock(&tcon->tc_lock); 1196 return ERR_PTR(-ENOENT); 1197 } 1198 spin_unlock(&tcon->tc_lock); 1199 return __cifs_get_super(tcon_super_cb, tcon); 1200 } 1201 1202 void cifs_put_tcp_super(struct super_block *sb) 1203 { 1204 __cifs_put_super(sb); 1205 } 1206 1207 #ifdef CONFIG_CIFS_DFS_UPCALL 1208 int match_target_ip(struct TCP_Server_Info *server, 1209 const char *host, size_t hostlen, 1210 bool *result) 1211 { 1212 struct sockaddr_storage ss; 1213 int rc; 1214 1215 cifs_dbg(FYI, "%s: hostname=%.*s\n", __func__, (int)hostlen, host); 1216 1217 *result = false; 1218 1219 rc = dns_resolve_name(server->dns_dom, host, hostlen, 1220 (struct sockaddr *)&ss); 1221 if (rc < 0) 1222 return rc; 1223 1224 spin_lock(&server->srv_lock); 1225 *result = cifs_match_ipaddr((struct sockaddr *)&server->dstaddr, (struct sockaddr *)&ss); 1226 spin_unlock(&server->srv_lock); 1227 cifs_dbg(FYI, "%s: ip addresses matched: %s\n", __func__, str_yes_no(*result)); 1228 return 0; 1229 } 1230 1231 int cifs_update_super_prepath(struct cifs_sb_info *cifs_sb, char *prefix) 1232 { 1233 int rc; 1234 1235 kfree(cifs_sb->prepath); 1236 cifs_sb->prepath = NULL; 1237 1238 if (prefix && *prefix) { 1239 cifs_sb->prepath = cifs_sanitize_prepath(prefix, GFP_ATOMIC); 1240 if (IS_ERR(cifs_sb->prepath)) { 1241 rc = PTR_ERR(cifs_sb->prepath); 1242 cifs_sb->prepath = NULL; 1243 return rc; 1244 } 1245 if (cifs_sb->prepath) 1246 convert_delimiter(cifs_sb->prepath, CIFS_DIR_SEP(cifs_sb)); 1247 } 1248 1249 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH; 1250 return 0; 1251 } 1252 1253 /* 1254 * Handle weird Windows SMB server behaviour. It responds with 1255 * STATUS_OBJECT_NAME_INVALID code to SMB2 QUERY_INFO request for 1256 * "\<server>\<dfsname>\<linkpath>" DFS reference, where <dfsname> contains 1257 * non-ASCII unicode symbols. 1258 */ 1259 int cifs_inval_name_dfs_link_error(const unsigned int xid, 1260 struct cifs_tcon *tcon, 1261 struct cifs_sb_info *cifs_sb, 1262 const char *full_path, 1263 bool *islink) 1264 { 1265 struct TCP_Server_Info *server = tcon->ses->server; 1266 struct cifs_ses *ses = tcon->ses; 1267 size_t len; 1268 char *path; 1269 char *ref_path; 1270 1271 *islink = false; 1272 1273 /* 1274 * Fast path - skip check when @full_path doesn't have a prefix path to 1275 * look up or tcon is not DFS. 1276 */ 1277 if (strlen(full_path) < 2 || !cifs_sb || 1278 (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_DFS) || 1279 !is_tcon_dfs(tcon)) 1280 return 0; 1281 1282 spin_lock(&server->srv_lock); 1283 if (!server->leaf_fullpath) { 1284 spin_unlock(&server->srv_lock); 1285 return 0; 1286 } 1287 spin_unlock(&server->srv_lock); 1288 1289 /* 1290 * Slow path - tcon is DFS and @full_path has prefix path, so attempt 1291 * to get a referral to figure out whether it is an DFS link. 1292 */ 1293 len = strnlen(tcon->tree_name, MAX_TREE_SIZE + 1) + strlen(full_path) + 1; 1294 path = kmalloc(len, GFP_KERNEL); 1295 if (!path) 1296 return -ENOMEM; 1297 1298 scnprintf(path, len, "%s%s", tcon->tree_name, full_path); 1299 ref_path = dfs_cache_canonical_path(path + 1, cifs_sb->local_nls, 1300 cifs_remap(cifs_sb)); 1301 kfree(path); 1302 1303 if (IS_ERR(ref_path)) { 1304 if (PTR_ERR(ref_path) != -EINVAL) 1305 return PTR_ERR(ref_path); 1306 } else { 1307 struct dfs_info3_param *refs = NULL; 1308 int num_refs = 0; 1309 1310 /* 1311 * XXX: we are not using dfs_cache_find() here because we might 1312 * end up filling all the DFS cache and thus potentially 1313 * removing cached DFS targets that the client would eventually 1314 * need during failover. 1315 */ 1316 ses = CIFS_DFS_ROOT_SES(ses); 1317 if (ses->server->ops->get_dfs_refer && 1318 !ses->server->ops->get_dfs_refer(xid, ses, ref_path, &refs, 1319 &num_refs, cifs_sb->local_nls, 1320 cifs_remap(cifs_sb))) 1321 *islink = refs[0].server_type == DFS_TYPE_LINK; 1322 free_dfs_info_array(refs, num_refs); 1323 kfree(ref_path); 1324 } 1325 return 0; 1326 } 1327 #endif 1328 1329 int cifs_wait_for_server_reconnect(struct TCP_Server_Info *server, bool retry) 1330 { 1331 int timeout = 10; 1332 int rc; 1333 1334 spin_lock(&server->srv_lock); 1335 if (server->tcpStatus != CifsNeedReconnect) { 1336 spin_unlock(&server->srv_lock); 1337 return 0; 1338 } 1339 timeout *= server->nr_targets; 1340 spin_unlock(&server->srv_lock); 1341 1342 /* 1343 * Give demultiplex thread up to 10 seconds to each target available for 1344 * reconnect -- should be greater than cifs socket timeout which is 7 1345 * seconds. 1346 * 1347 * On "soft" mounts we wait once. Hard mounts keep retrying until 1348 * process is killed or server comes back on-line. 1349 */ 1350 do { 1351 rc = wait_event_interruptible_timeout(server->response_q, 1352 (server->tcpStatus != CifsNeedReconnect), 1353 timeout * HZ); 1354 if (rc < 0) { 1355 cifs_dbg(FYI, "%s: aborting reconnect due to received signal\n", 1356 __func__); 1357 return -ERESTARTSYS; 1358 } 1359 1360 /* are we still trying to reconnect? */ 1361 spin_lock(&server->srv_lock); 1362 if (server->tcpStatus != CifsNeedReconnect) { 1363 spin_unlock(&server->srv_lock); 1364 return 0; 1365 } 1366 spin_unlock(&server->srv_lock); 1367 } while (retry); 1368 1369 cifs_dbg(FYI, "%s: gave up waiting on reconnect\n", __func__); 1370 return -EHOSTDOWN; 1371 } 1372