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
_get_xid(void)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
_free_xid(unsigned int xid)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 *
sesInfoAlloc(void)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
sesInfoFree(struct cifs_ses * buf_to_free)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 *
tcon_info_alloc(bool dir_leases_enabled,enum smb3_tcon_ref_trace trace)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
tconInfoFree(struct cifs_tcon * tcon,enum smb3_tcon_ref_trace trace)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 *
cifs_buf_get(void)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
cifs_buf_release(void * buf_to_free)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 *
cifs_small_buf_get(void)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
cifs_small_buf_release(void * buf_to_free)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
free_rsp_buf(int resp_buftype,void * rsp)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
header_assemble(struct smb_hdr * buffer,char smb_command,const struct cifs_tcon * treeCon,int word_count)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
check_smb_hdr(struct smb_hdr * smb)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
checkSMB(char * buf,unsigned int pdu_len,unsigned int total_read,struct TCP_Server_Info * server)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
is_valid_oplock_break(char * buffer,struct TCP_Server_Info * srv)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
dump_smb(void * buf,int smb_buf_length)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
cifs_autodisable_serverino(struct cifs_sb_info * cifs_sb)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
cifs_set_oplock_level(struct cifsInodeInfo * cinode,__u32 oplock)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 */
cifs_get_writer(struct cifsInodeInfo * cinode)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
cifs_put_writer(struct cifsInodeInfo * cinode)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 */
cifs_queue_oplock_break(struct cifsFileInfo * cfile)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
cifs_done_oplock_break(struct cifsInodeInfo * cinode)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
backup_cred(struct cifs_sb_info * cifs_sb)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
cifs_del_pending_open(struct cifs_pending_open * open)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
cifs_add_pending_open_locked(struct cifs_fid * fid,struct tcon_link * tlink,struct cifs_pending_open * open)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
cifs_add_pending_open(struct cifs_fid * fid,struct tcon_link * tlink,struct cifs_pending_open * open)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
cifs_is_deferred_close(struct cifsFileInfo * cfile,struct cifs_deferred_close ** pdclose)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
cifs_add_deferred_close(struct cifsFileInfo * cfile,struct cifs_deferred_close * dclose)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
cifs_del_deferred_close(struct cifsFileInfo * cfile)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
cifs_close_deferred_file(struct cifsInodeInfo * cifs_inode)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
cifs_close_all_deferred_files(struct cifs_tcon * tcon)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
cifs_close_deferred_file_under_dentry(struct cifs_tcon * tcon,struct dentry * dentry)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 */
cifs_mark_open_handles_for_deleted_file(struct inode * inode,const char * path)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
parse_dfs_referrals(struct get_dfs_referral_rsp * rsp,u32 rsp_size,unsigned int * num_of_nodes,struct dfs_info3_param ** target_nodes,const struct nls_table * nls_codepage,int remap,const char * searchName,bool is_unicode)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
cifs_alloc_hash(const char * name,struct shash_desc ** sdesc)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
cifs_free_hash(struct shash_desc ** sdesc)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
extract_unc_hostname(const char * unc,const char ** h,size_t * len)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 */
copy_path_name(char * dst,const char * src)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
tcon_super_cb(struct super_block * sb,void * arg)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
__cifs_get_super(void (* f)(struct super_block *,void *),void * data)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
__cifs_put_super(struct super_block * sb)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
cifs_get_dfs_tcon_super(struct cifs_tcon * tcon)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
cifs_put_tcp_super(struct super_block * sb)1202 void cifs_put_tcp_super(struct super_block *sb)
1203 {
1204 __cifs_put_super(sb);
1205 }
1206
1207 #ifdef CONFIG_CIFS_DFS_UPCALL
match_target_ip(struct TCP_Server_Info * server,const char * host,size_t hostlen,bool * result)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
cifs_update_super_prepath(struct cifs_sb_info * cifs_sb,char * prefix)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 */
cifs_inval_name_dfs_link_error(const unsigned int xid,struct cifs_tcon * tcon,struct cifs_sb_info * cifs_sb,const char * full_path,bool * islink)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
cifs_wait_for_server_reconnect(struct TCP_Server_Info * server,bool retry)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