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 "cifsfs.h"
22 #ifdef CONFIG_CIFS_DFS_UPCALL
23 #include "dns_resolve.h"
24 #include "dfs_cache.h"
25 #include "dfs.h"
26 #endif
27 #include "fs_context.h"
28 #include "cached_dir.h"
29
30 /* The xid serves as a useful identifier for each incoming vfs request,
31 in a similar way to the mid which is useful to track each sent smb,
32 and CurrentXid can also provide a running counter (although it
33 will eventually wrap past zero) of the total vfs operations handled
34 since the cifs fs was mounted */
35
36 unsigned int
_get_xid(void)37 _get_xid(void)
38 {
39 unsigned int xid;
40
41 spin_lock(&GlobalMid_Lock);
42 GlobalTotalActiveXid++;
43
44 /* keep high water mark for number of simultaneous ops in filesystem */
45 if (GlobalTotalActiveXid > GlobalMaxActiveXid)
46 GlobalMaxActiveXid = GlobalTotalActiveXid;
47 if (GlobalTotalActiveXid > 65000)
48 cifs_dbg(FYI, "warning: more than 65000 requests active\n");
49 xid = GlobalCurrentXid++;
50 spin_unlock(&GlobalMid_Lock);
51 return xid;
52 }
53
54 void
_free_xid(unsigned int xid)55 _free_xid(unsigned int xid)
56 {
57 spin_lock(&GlobalMid_Lock);
58 /* if (GlobalTotalActiveXid == 0)
59 BUG(); */
60 GlobalTotalActiveXid--;
61 spin_unlock(&GlobalMid_Lock);
62 }
63
64 struct cifs_ses *
sesInfoAlloc(void)65 sesInfoAlloc(void)
66 {
67 struct cifs_ses *ret_buf;
68
69 ret_buf = kzalloc(sizeof(struct cifs_ses), GFP_KERNEL);
70 if (ret_buf) {
71 atomic_inc(&sesInfoAllocCount);
72 spin_lock_init(&ret_buf->ses_lock);
73 ret_buf->ses_status = SES_NEW;
74 ++ret_buf->ses_count;
75 INIT_LIST_HEAD(&ret_buf->smb_ses_list);
76 INIT_LIST_HEAD(&ret_buf->tcon_list);
77 mutex_init(&ret_buf->session_mutex);
78 spin_lock_init(&ret_buf->iface_lock);
79 INIT_LIST_HEAD(&ret_buf->iface_list);
80 spin_lock_init(&ret_buf->chan_lock);
81 }
82 return ret_buf;
83 }
84
85 void
sesInfoFree(struct cifs_ses * buf_to_free)86 sesInfoFree(struct cifs_ses *buf_to_free)
87 {
88 struct cifs_server_iface *iface = NULL, *niface = NULL;
89
90 if (buf_to_free == NULL) {
91 cifs_dbg(FYI, "Null buffer passed to sesInfoFree\n");
92 return;
93 }
94
95 unload_nls(buf_to_free->local_nls);
96 atomic_dec(&sesInfoAllocCount);
97 kfree(buf_to_free->serverOS);
98 kfree(buf_to_free->serverDomain);
99 kfree(buf_to_free->serverNOS);
100 kfree_sensitive(buf_to_free->password);
101 kfree_sensitive(buf_to_free->password2);
102 kfree(buf_to_free->user_name);
103 kfree(buf_to_free->domainName);
104 kfree(buf_to_free->dns_dom);
105 kfree_sensitive(buf_to_free->auth_key.response);
106 spin_lock(&buf_to_free->iface_lock);
107 list_for_each_entry_safe(iface, niface, &buf_to_free->iface_list,
108 iface_head)
109 kref_put(&iface->refcount, release_iface);
110 spin_unlock(&buf_to_free->iface_lock);
111 kfree_sensitive(buf_to_free);
112 }
113
114 struct cifs_tcon *
tcon_info_alloc(bool dir_leases_enabled,enum smb3_tcon_ref_trace trace)115 tcon_info_alloc(bool dir_leases_enabled, enum smb3_tcon_ref_trace trace)
116 {
117 struct cifs_tcon *ret_buf;
118 static atomic_t tcon_debug_id;
119
120 ret_buf = kzalloc(sizeof(*ret_buf), GFP_KERNEL);
121 if (!ret_buf)
122 return NULL;
123
124 if (dir_leases_enabled == true) {
125 ret_buf->cfids = init_cached_dirs();
126 if (!ret_buf->cfids) {
127 kfree(ret_buf);
128 return NULL;
129 }
130 }
131 /* else ret_buf->cfids is already set to NULL above */
132
133 atomic_inc(&tconInfoAllocCount);
134 ret_buf->status = TID_NEW;
135 ret_buf->debug_id = atomic_inc_return(&tcon_debug_id);
136 ret_buf->tc_count = 1;
137 spin_lock_init(&ret_buf->tc_lock);
138 INIT_LIST_HEAD(&ret_buf->openFileList);
139 INIT_LIST_HEAD(&ret_buf->tcon_list);
140 INIT_LIST_HEAD(&ret_buf->cifs_sb_list);
141 spin_lock_init(&ret_buf->open_file_lock);
142 spin_lock_init(&ret_buf->stat_lock);
143 spin_lock_init(&ret_buf->sb_list_lock);
144 atomic_set(&ret_buf->num_local_opens, 0);
145 atomic_set(&ret_buf->num_remote_opens, 0);
146 ret_buf->stats_from_time = ktime_get_real_seconds();
147 #ifdef CONFIG_CIFS_FSCACHE
148 mutex_init(&ret_buf->fscache_lock);
149 #endif
150 trace_smb3_tcon_ref(ret_buf->debug_id, ret_buf->tc_count, trace);
151 #ifdef CONFIG_CIFS_DFS_UPCALL
152 INIT_LIST_HEAD(&ret_buf->dfs_ses_list);
153 #endif
154 INIT_LIST_HEAD(&ret_buf->pending_opens);
155 INIT_DELAYED_WORK(&ret_buf->query_interfaces,
156 smb2_query_server_interfaces);
157 #ifdef CONFIG_CIFS_DFS_UPCALL
158 INIT_DELAYED_WORK(&ret_buf->dfs_cache_work, dfs_cache_refresh);
159 #endif
160
161 return ret_buf;
162 }
163
164 void
tconInfoFree(struct cifs_tcon * tcon,enum smb3_tcon_ref_trace trace)165 tconInfoFree(struct cifs_tcon *tcon, enum smb3_tcon_ref_trace trace)
166 {
167 if (tcon == NULL) {
168 cifs_dbg(FYI, "Null buffer passed to tconInfoFree\n");
169 return;
170 }
171 trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count, trace);
172 free_cached_dirs(tcon->cfids);
173 atomic_dec(&tconInfoAllocCount);
174 kfree(tcon->nativeFileSystem);
175 kfree_sensitive(tcon->password);
176 kfree(tcon->origin_fullpath);
177 kfree(tcon);
178 }
179
180 struct smb_hdr *
cifs_buf_get(void)181 cifs_buf_get(void)
182 {
183 struct smb_hdr *ret_buf = NULL;
184 /*
185 * SMB2 header is bigger than CIFS one - no problems to clean some
186 * more bytes for CIFS.
187 */
188 size_t buf_size = sizeof(struct smb2_hdr);
189
190 /*
191 * We could use negotiated size instead of max_msgsize -
192 * but it may be more efficient to always alloc same size
193 * albeit slightly larger than necessary and maxbuffersize
194 * defaults to this and can not be bigger.
195 */
196 ret_buf = mempool_alloc(cifs_req_poolp, GFP_NOFS);
197
198 /* clear the first few header bytes */
199 /* for most paths, more is cleared in header_assemble */
200 memset(ret_buf, 0, buf_size + 3);
201 atomic_inc(&buf_alloc_count);
202 #ifdef CONFIG_CIFS_STATS2
203 atomic_inc(&total_buf_alloc_count);
204 #endif /* CONFIG_CIFS_STATS2 */
205
206 return ret_buf;
207 }
208
209 void
cifs_buf_release(void * buf_to_free)210 cifs_buf_release(void *buf_to_free)
211 {
212 if (buf_to_free == NULL) {
213 /* cifs_dbg(FYI, "Null buffer passed to cifs_buf_release\n");*/
214 return;
215 }
216 mempool_free(buf_to_free, cifs_req_poolp);
217
218 atomic_dec(&buf_alloc_count);
219 return;
220 }
221
222 struct smb_hdr *
cifs_small_buf_get(void)223 cifs_small_buf_get(void)
224 {
225 struct smb_hdr *ret_buf = NULL;
226
227 /* We could use negotiated size instead of max_msgsize -
228 but it may be more efficient to always alloc same size
229 albeit slightly larger than necessary and maxbuffersize
230 defaults to this and can not be bigger */
231 ret_buf = mempool_alloc(cifs_sm_req_poolp, GFP_NOFS);
232 /* No need to clear memory here, cleared in header assemble */
233 /* memset(ret_buf, 0, sizeof(struct smb_hdr) + 27);*/
234 atomic_inc(&small_buf_alloc_count);
235 #ifdef CONFIG_CIFS_STATS2
236 atomic_inc(&total_small_buf_alloc_count);
237 #endif /* CONFIG_CIFS_STATS2 */
238
239 return ret_buf;
240 }
241
242 void
cifs_small_buf_release(void * buf_to_free)243 cifs_small_buf_release(void *buf_to_free)
244 {
245
246 if (buf_to_free == NULL) {
247 cifs_dbg(FYI, "Null buffer passed to cifs_small_buf_release\n");
248 return;
249 }
250 mempool_free(buf_to_free, cifs_sm_req_poolp);
251
252 atomic_dec(&small_buf_alloc_count);
253 return;
254 }
255
256 void
free_rsp_buf(int resp_buftype,void * rsp)257 free_rsp_buf(int resp_buftype, void *rsp)
258 {
259 if (resp_buftype == CIFS_SMALL_BUFFER)
260 cifs_small_buf_release(rsp);
261 else if (resp_buftype == CIFS_LARGE_BUFFER)
262 cifs_buf_release(rsp);
263 }
264
265 /* NB: MID can not be set if treeCon not passed in, in that
266 case it is responsibility of caller to set the mid */
267 void
header_assemble(struct smb_hdr * buffer,char smb_command,const struct cifs_tcon * treeCon,int word_count)268 header_assemble(struct smb_hdr *buffer, char smb_command /* command */ ,
269 const struct cifs_tcon *treeCon, int word_count
270 /* length of fixed section (word count) in two byte units */)
271 {
272 char *temp = (char *) buffer;
273
274 memset(temp, 0, 256); /* bigger than MAX_CIFS_HDR_SIZE */
275
276 buffer->smb_buf_length = cpu_to_be32(
277 (2 * word_count) + sizeof(struct smb_hdr) -
278 4 /* RFC 1001 length field does not count */ +
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;
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 != cpu_to_le32(0x424d53ff)) {
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 total_read,struct TCP_Server_Info * server)349 checkSMB(char *buf, unsigned int total_read, struct TCP_Server_Info *server)
350 {
351 struct smb_hdr *smb = (struct smb_hdr *)buf;
352 __u32 rfclen = be32_to_cpu(smb->smb_buf_length);
353 __u32 clc_len; /* calculated length */
354 cifs_dbg(FYI, "checkSMB Length: 0x%x, smb_buf_length: 0x%x\n",
355 total_read, rfclen);
356
357 /* is this frame too small to even get to a BCC? */
358 if (total_read < 2 + sizeof(struct smb_hdr)) {
359 if ((total_read >= sizeof(struct smb_hdr) - 1)
360 && (smb->Status.CifsError != 0)) {
361 /* it's an error return */
362 smb->WordCount = 0;
363 /* some error cases do not return wct and bcc */
364 return 0;
365 } else if ((total_read == sizeof(struct smb_hdr) + 1) &&
366 (smb->WordCount == 0)) {
367 char *tmp = (char *)smb;
368 /* Need to work around a bug in two servers here */
369 /* First, check if the part of bcc they sent was zero */
370 if (tmp[sizeof(struct smb_hdr)] == 0) {
371 /* some servers return only half of bcc
372 * on simple responses (wct, bcc both zero)
373 * in particular have seen this on
374 * ulogoffX and FindClose. This leaves
375 * one byte of bcc potentially uninitialized
376 */
377 /* zero rest of bcc */
378 tmp[sizeof(struct smb_hdr)+1] = 0;
379 return 0;
380 }
381 cifs_dbg(VFS, "rcvd invalid byte count (bcc)\n");
382 } else {
383 cifs_dbg(VFS, "Length less than smb header size\n");
384 }
385 return -EIO;
386 } else if (total_read < sizeof(*smb) + 2 * smb->WordCount) {
387 cifs_dbg(VFS, "%s: can't read BCC due to invalid WordCount(%u)\n",
388 __func__, smb->WordCount);
389 return -EIO;
390 }
391
392 /* otherwise, there is enough to get to the BCC */
393 if (check_smb_hdr(smb))
394 return -EIO;
395 clc_len = smbCalcSize(smb);
396
397 if (4 + rfclen != total_read) {
398 cifs_dbg(VFS, "Length read does not match RFC1001 length %d\n",
399 rfclen);
400 return -EIO;
401 }
402
403 if (4 + rfclen != clc_len) {
404 __u16 mid = get_mid(smb);
405 /* check if bcc wrapped around for large read responses */
406 if ((rfclen > 64 * 1024) && (rfclen > clc_len)) {
407 /* check if lengths match mod 64K */
408 if (((4 + rfclen) & 0xFFFF) == (clc_len & 0xFFFF))
409 return 0; /* bcc wrapped */
410 }
411 cifs_dbg(FYI, "Calculated size %u vs length %u mismatch for mid=%u\n",
412 clc_len, 4 + rfclen, mid);
413
414 if (4 + rfclen < clc_len) {
415 cifs_dbg(VFS, "RFC1001 size %u smaller than SMB for mid=%u\n",
416 rfclen, mid);
417 return -EIO;
418 } else if (rfclen > clc_len + 512) {
419 /*
420 * Some servers (Windows XP in particular) send more
421 * data than the lengths in the SMB packet would
422 * indicate on certain calls (byte range locks and
423 * trans2 find first calls in particular). While the
424 * client can handle such a frame by ignoring the
425 * trailing data, we choose limit the amount of extra
426 * data to 512 bytes.
427 */
428 cifs_dbg(VFS, "RFC1001 size %u more than 512 bytes larger than SMB for mid=%u\n",
429 rfclen, mid);
430 return -EIO;
431 }
432 }
433 return 0;
434 }
435
436 bool
is_valid_oplock_break(char * buffer,struct TCP_Server_Info * srv)437 is_valid_oplock_break(char *buffer, struct TCP_Server_Info *srv)
438 {
439 struct smb_hdr *buf = (struct smb_hdr *)buffer;
440 struct smb_com_lock_req *pSMB = (struct smb_com_lock_req *)buf;
441 struct TCP_Server_Info *pserver;
442 struct cifs_ses *ses;
443 struct cifs_tcon *tcon;
444 struct cifsInodeInfo *pCifsInode;
445 struct cifsFileInfo *netfile;
446
447 cifs_dbg(FYI, "Checking for oplock break or dnotify response\n");
448 if ((pSMB->hdr.Command == SMB_COM_NT_TRANSACT) &&
449 (pSMB->hdr.Flags & SMBFLG_RESPONSE)) {
450 struct smb_com_transaction_change_notify_rsp *pSMBr =
451 (struct smb_com_transaction_change_notify_rsp *)buf;
452 struct file_notify_information *pnotify;
453 __u32 data_offset = 0;
454 size_t len = srv->total_read - sizeof(pSMBr->hdr.smb_buf_length);
455
456 if (get_bcc(buf) > sizeof(struct file_notify_information)) {
457 data_offset = le32_to_cpu(pSMBr->DataOffset);
458
459 if (data_offset >
460 len - sizeof(struct file_notify_information)) {
461 cifs_dbg(FYI, "Invalid data_offset %u\n",
462 data_offset);
463 return true;
464 }
465 pnotify = (struct file_notify_information *)
466 ((char *)&pSMBr->hdr.Protocol + data_offset);
467 cifs_dbg(FYI, "dnotify on %s Action: 0x%x\n",
468 pnotify->FileName, pnotify->Action);
469 /* cifs_dump_mem("Rcvd notify Data: ",buf,
470 sizeof(struct smb_hdr)+60); */
471 return true;
472 }
473 if (pSMBr->hdr.Status.CifsError) {
474 cifs_dbg(FYI, "notify err 0x%x\n",
475 pSMBr->hdr.Status.CifsError);
476 return true;
477 }
478 return false;
479 }
480 if (pSMB->hdr.Command != SMB_COM_LOCKING_ANDX)
481 return false;
482 if (pSMB->hdr.Flags & SMBFLG_RESPONSE) {
483 /* no sense logging error on invalid handle on oplock
484 break - harmless race between close request and oplock
485 break response is expected from time to time writing out
486 large dirty files cached on the client */
487 if ((NT_STATUS_INVALID_HANDLE) ==
488 le32_to_cpu(pSMB->hdr.Status.CifsError)) {
489 cifs_dbg(FYI, "Invalid handle on oplock break\n");
490 return true;
491 } else if (ERRbadfid ==
492 le16_to_cpu(pSMB->hdr.Status.DosError.Error)) {
493 return true;
494 } else {
495 return false; /* on valid oplock brk we get "request" */
496 }
497 }
498 if (pSMB->hdr.WordCount != 8)
499 return false;
500
501 cifs_dbg(FYI, "oplock type 0x%x level 0x%x\n",
502 pSMB->LockType, pSMB->OplockLevel);
503 if (!(pSMB->LockType & LOCKING_ANDX_OPLOCK_RELEASE))
504 return false;
505
506 /* If server is a channel, select the primary channel */
507 pserver = SERVER_IS_CHAN(srv) ? srv->primary_server : srv;
508
509 /* look up tcon based on tid & uid */
510 spin_lock(&cifs_tcp_ses_lock);
511 list_for_each_entry(ses, &pserver->smb_ses_list, smb_ses_list) {
512 if (cifs_ses_exiting(ses))
513 continue;
514 list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
515 if (tcon->tid != buf->Tid)
516 continue;
517
518 cifs_stats_inc(&tcon->stats.cifs_stats.num_oplock_brks);
519 spin_lock(&tcon->open_file_lock);
520 list_for_each_entry(netfile, &tcon->openFileList, tlist) {
521 if (pSMB->Fid != netfile->fid.netfid)
522 continue;
523
524 cifs_dbg(FYI, "file id match, oplock break\n");
525 pCifsInode = CIFS_I(d_inode(netfile->dentry));
526
527 set_bit(CIFS_INODE_PENDING_OPLOCK_BREAK,
528 &pCifsInode->flags);
529
530 netfile->oplock_epoch = 0;
531 netfile->oplock_level = pSMB->OplockLevel;
532 netfile->oplock_break_cancelled = false;
533 cifs_queue_oplock_break(netfile);
534
535 spin_unlock(&tcon->open_file_lock);
536 spin_unlock(&cifs_tcp_ses_lock);
537 return true;
538 }
539 spin_unlock(&tcon->open_file_lock);
540 spin_unlock(&cifs_tcp_ses_lock);
541 cifs_dbg(FYI, "No matching file for oplock break\n");
542 return true;
543 }
544 }
545 spin_unlock(&cifs_tcp_ses_lock);
546 cifs_dbg(FYI, "Can not process oplock break for non-existent connection\n");
547 return true;
548 }
549
550 void
dump_smb(void * buf,int smb_buf_length)551 dump_smb(void *buf, int smb_buf_length)
552 {
553 if (traceSMB == 0)
554 return;
555
556 print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_NONE, 8, 2, buf,
557 smb_buf_length, true);
558 }
559
560 void
cifs_autodisable_serverino(struct cifs_sb_info * cifs_sb)561 cifs_autodisable_serverino(struct cifs_sb_info *cifs_sb)
562 {
563 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) {
564 struct cifs_tcon *tcon = NULL;
565
566 if (cifs_sb->master_tlink)
567 tcon = cifs_sb_master_tcon(cifs_sb);
568
569 cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM;
570 cifs_sb->mnt_cifs_serverino_autodisabled = true;
571 cifs_dbg(VFS, "Autodisabling the use of server inode numbers on %s\n",
572 tcon ? tcon->tree_name : "new server");
573 cifs_dbg(VFS, "The server doesn't seem to support them properly or the files might be on different servers (DFS)\n");
574 cifs_dbg(VFS, "Hardlinks will not be recognized on this mount. Consider mounting with the \"noserverino\" option to silence this message.\n");
575
576 }
577 }
578
cifs_set_oplock_level(struct cifsInodeInfo * cinode,__u32 oplock)579 void cifs_set_oplock_level(struct cifsInodeInfo *cinode, __u32 oplock)
580 {
581 oplock &= 0xF;
582
583 if (oplock == OPLOCK_EXCLUSIVE) {
584 cinode->oplock = CIFS_CACHE_WRITE_FLG | CIFS_CACHE_READ_FLG;
585 cifs_dbg(FYI, "Exclusive Oplock granted on inode %p\n",
586 &cinode->netfs.inode);
587 } else if (oplock == OPLOCK_READ) {
588 cinode->oplock = CIFS_CACHE_READ_FLG;
589 cifs_dbg(FYI, "Level II Oplock granted on inode %p\n",
590 &cinode->netfs.inode);
591 } else
592 cinode->oplock = 0;
593 }
594
595 /*
596 * We wait for oplock breaks to be processed before we attempt to perform
597 * writes.
598 */
cifs_get_writer(struct cifsInodeInfo * cinode)599 int cifs_get_writer(struct cifsInodeInfo *cinode)
600 {
601 int rc;
602
603 start:
604 rc = wait_on_bit(&cinode->flags, CIFS_INODE_PENDING_OPLOCK_BREAK,
605 TASK_KILLABLE);
606 if (rc)
607 return rc;
608
609 spin_lock(&cinode->writers_lock);
610 if (!cinode->writers)
611 set_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags);
612 cinode->writers++;
613 /* Check to see if we have started servicing an oplock break */
614 if (test_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, &cinode->flags)) {
615 cinode->writers--;
616 if (cinode->writers == 0) {
617 clear_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags);
618 wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_WRITERS);
619 }
620 spin_unlock(&cinode->writers_lock);
621 goto start;
622 }
623 spin_unlock(&cinode->writers_lock);
624 return 0;
625 }
626
cifs_put_writer(struct cifsInodeInfo * cinode)627 void cifs_put_writer(struct cifsInodeInfo *cinode)
628 {
629 spin_lock(&cinode->writers_lock);
630 cinode->writers--;
631 if (cinode->writers == 0) {
632 clear_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags);
633 wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_WRITERS);
634 }
635 spin_unlock(&cinode->writers_lock);
636 }
637
638 /**
639 * cifs_queue_oplock_break - queue the oplock break handler for cfile
640 * @cfile: The file to break the oplock on
641 *
642 * This function is called from the demultiplex thread when it
643 * receives an oplock break for @cfile.
644 *
645 * Assumes the tcon->open_file_lock is held.
646 * Assumes cfile->file_info_lock is NOT held.
647 */
cifs_queue_oplock_break(struct cifsFileInfo * cfile)648 void cifs_queue_oplock_break(struct cifsFileInfo *cfile)
649 {
650 /*
651 * Bump the handle refcount now while we hold the
652 * open_file_lock to enforce the validity of it for the oplock
653 * break handler. The matching put is done at the end of the
654 * handler.
655 */
656 cifsFileInfo_get(cfile);
657
658 queue_work(cifsoplockd_wq, &cfile->oplock_break);
659 }
660
cifs_done_oplock_break(struct cifsInodeInfo * cinode)661 void cifs_done_oplock_break(struct cifsInodeInfo *cinode)
662 {
663 clear_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, &cinode->flags);
664 wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_OPLOCK_BREAK);
665 }
666
667 bool
backup_cred(struct cifs_sb_info * cifs_sb)668 backup_cred(struct cifs_sb_info *cifs_sb)
669 {
670 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPUID) {
671 if (uid_eq(cifs_sb->ctx->backupuid, current_fsuid()))
672 return true;
673 }
674 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPGID) {
675 if (in_group_p(cifs_sb->ctx->backupgid))
676 return true;
677 }
678
679 return false;
680 }
681
682 void
cifs_del_pending_open(struct cifs_pending_open * open)683 cifs_del_pending_open(struct cifs_pending_open *open)
684 {
685 spin_lock(&tlink_tcon(open->tlink)->open_file_lock);
686 list_del(&open->olist);
687 spin_unlock(&tlink_tcon(open->tlink)->open_file_lock);
688 }
689
690 void
cifs_add_pending_open_locked(struct cifs_fid * fid,struct tcon_link * tlink,struct cifs_pending_open * open)691 cifs_add_pending_open_locked(struct cifs_fid *fid, struct tcon_link *tlink,
692 struct cifs_pending_open *open)
693 {
694 memcpy(open->lease_key, fid->lease_key, SMB2_LEASE_KEY_SIZE);
695 open->oplock = CIFS_OPLOCK_NO_CHANGE;
696 open->tlink = tlink;
697 fid->pending_open = open;
698 list_add_tail(&open->olist, &tlink_tcon(tlink)->pending_opens);
699 }
700
701 void
cifs_add_pending_open(struct cifs_fid * fid,struct tcon_link * tlink,struct cifs_pending_open * open)702 cifs_add_pending_open(struct cifs_fid *fid, struct tcon_link *tlink,
703 struct cifs_pending_open *open)
704 {
705 spin_lock(&tlink_tcon(tlink)->open_file_lock);
706 cifs_add_pending_open_locked(fid, tlink, open);
707 spin_unlock(&tlink_tcon(open->tlink)->open_file_lock);
708 }
709
710 /*
711 * Critical section which runs after acquiring deferred_lock.
712 * As there is no reference count on cifs_deferred_close, pdclose
713 * should not be used outside deferred_lock.
714 */
715 bool
cifs_is_deferred_close(struct cifsFileInfo * cfile,struct cifs_deferred_close ** pdclose)716 cifs_is_deferred_close(struct cifsFileInfo *cfile, struct cifs_deferred_close **pdclose)
717 {
718 struct cifs_deferred_close *dclose;
719
720 list_for_each_entry(dclose, &CIFS_I(d_inode(cfile->dentry))->deferred_closes, dlist) {
721 if ((dclose->netfid == cfile->fid.netfid) &&
722 (dclose->persistent_fid == cfile->fid.persistent_fid) &&
723 (dclose->volatile_fid == cfile->fid.volatile_fid)) {
724 *pdclose = dclose;
725 return true;
726 }
727 }
728 return false;
729 }
730
731 /*
732 * Critical section which runs after acquiring deferred_lock.
733 */
734 void
cifs_add_deferred_close(struct cifsFileInfo * cfile,struct cifs_deferred_close * dclose)735 cifs_add_deferred_close(struct cifsFileInfo *cfile, struct cifs_deferred_close *dclose)
736 {
737 bool is_deferred = false;
738 struct cifs_deferred_close *pdclose;
739
740 is_deferred = cifs_is_deferred_close(cfile, &pdclose);
741 if (is_deferred) {
742 kfree(dclose);
743 return;
744 }
745
746 dclose->tlink = cfile->tlink;
747 dclose->netfid = cfile->fid.netfid;
748 dclose->persistent_fid = cfile->fid.persistent_fid;
749 dclose->volatile_fid = cfile->fid.volatile_fid;
750 list_add_tail(&dclose->dlist, &CIFS_I(d_inode(cfile->dentry))->deferred_closes);
751 }
752
753 /*
754 * Critical section which runs after acquiring deferred_lock.
755 */
756 void
cifs_del_deferred_close(struct cifsFileInfo * cfile)757 cifs_del_deferred_close(struct cifsFileInfo *cfile)
758 {
759 bool is_deferred = false;
760 struct cifs_deferred_close *dclose;
761
762 is_deferred = cifs_is_deferred_close(cfile, &dclose);
763 if (!is_deferred)
764 return;
765 list_del(&dclose->dlist);
766 kfree(dclose);
767 }
768
769 void
cifs_close_deferred_file(struct cifsInodeInfo * cifs_inode)770 cifs_close_deferred_file(struct cifsInodeInfo *cifs_inode)
771 {
772 struct cifsFileInfo *cfile = NULL;
773 struct file_list *tmp_list, *tmp_next_list;
774 LIST_HEAD(file_head);
775
776 if (cifs_inode == NULL)
777 return;
778
779 spin_lock(&cifs_inode->open_file_lock);
780 list_for_each_entry(cfile, &cifs_inode->openFileList, flist) {
781 if (delayed_work_pending(&cfile->deferred)) {
782 if (cancel_delayed_work(&cfile->deferred)) {
783 spin_lock(&cifs_inode->deferred_lock);
784 cifs_del_deferred_close(cfile);
785 spin_unlock(&cifs_inode->deferred_lock);
786
787 tmp_list = kmalloc(sizeof(struct file_list), GFP_ATOMIC);
788 if (tmp_list == NULL)
789 break;
790 tmp_list->cfile = cfile;
791 list_add_tail(&tmp_list->list, &file_head);
792 }
793 }
794 }
795 spin_unlock(&cifs_inode->open_file_lock);
796
797 list_for_each_entry_safe(tmp_list, tmp_next_list, &file_head, list) {
798 _cifsFileInfo_put(tmp_list->cfile, false, false);
799 list_del(&tmp_list->list);
800 kfree(tmp_list);
801 }
802 }
803
804 void
cifs_close_all_deferred_files(struct cifs_tcon * tcon)805 cifs_close_all_deferred_files(struct cifs_tcon *tcon)
806 {
807 struct cifsFileInfo *cfile;
808 struct file_list *tmp_list, *tmp_next_list;
809 LIST_HEAD(file_head);
810
811 spin_lock(&tcon->open_file_lock);
812 list_for_each_entry(cfile, &tcon->openFileList, tlist) {
813 if (delayed_work_pending(&cfile->deferred)) {
814 if (cancel_delayed_work(&cfile->deferred)) {
815 spin_lock(&CIFS_I(d_inode(cfile->dentry))->deferred_lock);
816 cifs_del_deferred_close(cfile);
817 spin_unlock(&CIFS_I(d_inode(cfile->dentry))->deferred_lock);
818
819 tmp_list = kmalloc(sizeof(struct file_list), GFP_ATOMIC);
820 if (tmp_list == NULL)
821 break;
822 tmp_list->cfile = cfile;
823 list_add_tail(&tmp_list->list, &file_head);
824 }
825 }
826 }
827 spin_unlock(&tcon->open_file_lock);
828
829 list_for_each_entry_safe(tmp_list, tmp_next_list, &file_head, list) {
830 _cifsFileInfo_put(tmp_list->cfile, true, false);
831 list_del(&tmp_list->list);
832 kfree(tmp_list);
833 }
834 }
835 void
cifs_close_deferred_file_under_dentry(struct cifs_tcon * tcon,const char * path)836 cifs_close_deferred_file_under_dentry(struct cifs_tcon *tcon, const char *path)
837 {
838 struct cifsFileInfo *cfile;
839 struct file_list *tmp_list, *tmp_next_list;
840 void *page;
841 const char *full_path;
842 LIST_HEAD(file_head);
843
844 page = alloc_dentry_path();
845 spin_lock(&tcon->open_file_lock);
846 list_for_each_entry(cfile, &tcon->openFileList, tlist) {
847 full_path = build_path_from_dentry(cfile->dentry, page);
848 if (strstr(full_path, path)) {
849 if (delayed_work_pending(&cfile->deferred)) {
850 if (cancel_delayed_work(&cfile->deferred)) {
851 spin_lock(&CIFS_I(d_inode(cfile->dentry))->deferred_lock);
852 cifs_del_deferred_close(cfile);
853 spin_unlock(&CIFS_I(d_inode(cfile->dentry))->deferred_lock);
854
855 tmp_list = kmalloc(sizeof(struct file_list), GFP_ATOMIC);
856 if (tmp_list == NULL)
857 break;
858 tmp_list->cfile = cfile;
859 list_add_tail(&tmp_list->list, &file_head);
860 }
861 }
862 }
863 }
864 spin_unlock(&tcon->open_file_lock);
865
866 list_for_each_entry_safe(tmp_list, tmp_next_list, &file_head, list) {
867 _cifsFileInfo_put(tmp_list->cfile, true, false);
868 list_del(&tmp_list->list);
869 kfree(tmp_list);
870 }
871 free_dentry_path(page);
872 }
873
874 /*
875 * If a dentry has been deleted, all corresponding open handles should know that
876 * so that we do not defer close them.
877 */
cifs_mark_open_handles_for_deleted_file(struct inode * inode,const char * path)878 void cifs_mark_open_handles_for_deleted_file(struct inode *inode,
879 const char *path)
880 {
881 struct cifsFileInfo *cfile;
882 void *page;
883 const char *full_path;
884 struct cifsInodeInfo *cinode = CIFS_I(inode);
885
886 page = alloc_dentry_path();
887 spin_lock(&cinode->open_file_lock);
888
889 /*
890 * note: we need to construct path from dentry and compare only if the
891 * inode has any hardlinks. When number of hardlinks is 1, we can just
892 * mark all open handles since they are going to be from the same file.
893 */
894 if (inode->i_nlink > 1) {
895 list_for_each_entry(cfile, &cinode->openFileList, flist) {
896 full_path = build_path_from_dentry(cfile->dentry, page);
897 if (!IS_ERR(full_path) && strcmp(full_path, path) == 0)
898 cfile->status_file_deleted = true;
899 }
900 } else {
901 list_for_each_entry(cfile, &cinode->openFileList, flist)
902 cfile->status_file_deleted = true;
903 }
904 spin_unlock(&cinode->open_file_lock);
905 free_dentry_path(page);
906 }
907
908 /* parses DFS referral V3 structure
909 * caller is responsible for freeing target_nodes
910 * returns:
911 * - on success - 0
912 * - on failure - errno
913 */
914 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)915 parse_dfs_referrals(struct get_dfs_referral_rsp *rsp, u32 rsp_size,
916 unsigned int *num_of_nodes,
917 struct dfs_info3_param **target_nodes,
918 const struct nls_table *nls_codepage, int remap,
919 const char *searchName, bool is_unicode)
920 {
921 int i, rc = 0;
922 char *data_end;
923 struct dfs_referral_level_3 *ref;
924
925 *num_of_nodes = le16_to_cpu(rsp->NumberOfReferrals);
926
927 if (*num_of_nodes < 1) {
928 cifs_dbg(VFS | ONCE, "%s: [path=%s] num_referrals must be at least > 0, but we got %d\n",
929 __func__, searchName, *num_of_nodes);
930 rc = -ENOENT;
931 goto parse_DFS_referrals_exit;
932 }
933
934 ref = (struct dfs_referral_level_3 *) &(rsp->referrals);
935 if (ref->VersionNumber != cpu_to_le16(3)) {
936 cifs_dbg(VFS, "Referrals of V%d version are not supported, should be V3\n",
937 le16_to_cpu(ref->VersionNumber));
938 rc = -EINVAL;
939 goto parse_DFS_referrals_exit;
940 }
941
942 /* get the upper boundary of the resp buffer */
943 data_end = (char *)rsp + rsp_size;
944
945 cifs_dbg(FYI, "num_referrals: %d dfs flags: 0x%x ...\n",
946 *num_of_nodes, le32_to_cpu(rsp->DFSFlags));
947
948 *target_nodes = kcalloc(*num_of_nodes, sizeof(struct dfs_info3_param),
949 GFP_KERNEL);
950 if (*target_nodes == NULL) {
951 rc = -ENOMEM;
952 goto parse_DFS_referrals_exit;
953 }
954
955 /* collect necessary data from referrals */
956 for (i = 0; i < *num_of_nodes; i++) {
957 char *temp;
958 int max_len;
959 struct dfs_info3_param *node = (*target_nodes)+i;
960
961 node->flags = le32_to_cpu(rsp->DFSFlags);
962 if (is_unicode) {
963 __le16 *tmp = kmalloc(strlen(searchName)*2 + 2,
964 GFP_KERNEL);
965 if (tmp == NULL) {
966 rc = -ENOMEM;
967 goto parse_DFS_referrals_exit;
968 }
969 cifsConvertToUTF16((__le16 *) tmp, searchName,
970 PATH_MAX, nls_codepage, remap);
971 node->path_consumed = cifs_utf16_bytes(tmp,
972 le16_to_cpu(rsp->PathConsumed),
973 nls_codepage);
974 kfree(tmp);
975 } else
976 node->path_consumed = le16_to_cpu(rsp->PathConsumed);
977
978 node->server_type = le16_to_cpu(ref->ServerType);
979 node->ref_flag = le16_to_cpu(ref->ReferralEntryFlags);
980
981 /* copy DfsPath */
982 temp = (char *)ref + le16_to_cpu(ref->DfsPathOffset);
983 max_len = data_end - temp;
984 node->path_name = cifs_strndup_from_utf16(temp, max_len,
985 is_unicode, nls_codepage);
986 if (!node->path_name) {
987 rc = -ENOMEM;
988 goto parse_DFS_referrals_exit;
989 }
990
991 /* copy link target UNC */
992 temp = (char *)ref + le16_to_cpu(ref->NetworkAddressOffset);
993 max_len = data_end - temp;
994 node->node_name = cifs_strndup_from_utf16(temp, max_len,
995 is_unicode, nls_codepage);
996 if (!node->node_name) {
997 rc = -ENOMEM;
998 goto parse_DFS_referrals_exit;
999 }
1000
1001 node->ttl = le32_to_cpu(ref->TimeToLive);
1002
1003 ref++;
1004 }
1005
1006 parse_DFS_referrals_exit:
1007 if (rc) {
1008 free_dfs_info_array(*target_nodes, *num_of_nodes);
1009 *target_nodes = NULL;
1010 *num_of_nodes = 0;
1011 }
1012 return rc;
1013 }
1014
1015 /**
1016 * cifs_alloc_hash - allocate hash and hash context together
1017 * @name: The name of the crypto hash algo
1018 * @sdesc: SHASH descriptor where to put the pointer to the hash TFM
1019 *
1020 * The caller has to make sure @sdesc is initialized to either NULL or
1021 * a valid context. It can be freed via cifs_free_hash().
1022 */
1023 int
cifs_alloc_hash(const char * name,struct shash_desc ** sdesc)1024 cifs_alloc_hash(const char *name, struct shash_desc **sdesc)
1025 {
1026 int rc = 0;
1027 struct crypto_shash *alg = NULL;
1028
1029 if (*sdesc)
1030 return 0;
1031
1032 alg = crypto_alloc_shash(name, 0, 0);
1033 if (IS_ERR(alg)) {
1034 cifs_dbg(VFS, "Could not allocate shash TFM '%s'\n", name);
1035 rc = PTR_ERR(alg);
1036 *sdesc = NULL;
1037 return rc;
1038 }
1039
1040 *sdesc = kmalloc(sizeof(struct shash_desc) + crypto_shash_descsize(alg), GFP_KERNEL);
1041 if (*sdesc == NULL) {
1042 cifs_dbg(VFS, "no memory left to allocate shash TFM '%s'\n", name);
1043 crypto_free_shash(alg);
1044 return -ENOMEM;
1045 }
1046
1047 (*sdesc)->tfm = alg;
1048 return 0;
1049 }
1050
1051 /**
1052 * cifs_free_hash - free hash and hash context together
1053 * @sdesc: Where to find the pointer to the hash TFM
1054 *
1055 * Freeing a NULL descriptor is safe.
1056 */
1057 void
cifs_free_hash(struct shash_desc ** sdesc)1058 cifs_free_hash(struct shash_desc **sdesc)
1059 {
1060 if (unlikely(!sdesc) || !*sdesc)
1061 return;
1062
1063 if ((*sdesc)->tfm) {
1064 crypto_free_shash((*sdesc)->tfm);
1065 (*sdesc)->tfm = NULL;
1066 }
1067
1068 kfree_sensitive(*sdesc);
1069 *sdesc = NULL;
1070 }
1071
extract_unc_hostname(const char * unc,const char ** h,size_t * len)1072 void extract_unc_hostname(const char *unc, const char **h, size_t *len)
1073 {
1074 const char *end;
1075
1076 /* skip initial slashes */
1077 while (*unc && (*unc == '\\' || *unc == '/'))
1078 unc++;
1079
1080 end = unc;
1081
1082 while (*end && !(*end == '\\' || *end == '/'))
1083 end++;
1084
1085 *h = unc;
1086 *len = end - unc;
1087 }
1088
1089 /**
1090 * copy_path_name - copy src path to dst, possibly truncating
1091 * @dst: The destination buffer
1092 * @src: The source name
1093 *
1094 * returns number of bytes written (including trailing nul)
1095 */
copy_path_name(char * dst,const char * src)1096 int copy_path_name(char *dst, const char *src)
1097 {
1098 int name_len;
1099
1100 /*
1101 * PATH_MAX includes nul, so if strlen(src) >= PATH_MAX it
1102 * will truncate and strlen(dst) will be PATH_MAX-1
1103 */
1104 name_len = strscpy(dst, src, PATH_MAX);
1105 if (WARN_ON_ONCE(name_len < 0))
1106 name_len = PATH_MAX-1;
1107
1108 /* we count the trailing nul */
1109 name_len++;
1110 return name_len;
1111 }
1112
1113 struct super_cb_data {
1114 void *data;
1115 struct super_block *sb;
1116 };
1117
tcon_super_cb(struct super_block * sb,void * arg)1118 static void tcon_super_cb(struct super_block *sb, void *arg)
1119 {
1120 struct super_cb_data *sd = arg;
1121 struct cifs_sb_info *cifs_sb;
1122 struct cifs_tcon *t1 = sd->data, *t2;
1123
1124 if (sd->sb)
1125 return;
1126
1127 cifs_sb = CIFS_SB(sb);
1128 t2 = cifs_sb_master_tcon(cifs_sb);
1129
1130 spin_lock(&t2->tc_lock);
1131 if ((t1->ses == t2->ses ||
1132 t1->ses->dfs_root_ses == t2->ses->dfs_root_ses) &&
1133 t1->ses->server == t2->ses->server &&
1134 t2->origin_fullpath &&
1135 dfs_src_pathname_equal(t2->origin_fullpath, t1->origin_fullpath))
1136 sd->sb = sb;
1137 spin_unlock(&t2->tc_lock);
1138 }
1139
__cifs_get_super(void (* f)(struct super_block *,void *),void * data)1140 static struct super_block *__cifs_get_super(void (*f)(struct super_block *, void *),
1141 void *data)
1142 {
1143 struct super_cb_data sd = {
1144 .data = data,
1145 .sb = NULL,
1146 };
1147 struct file_system_type **fs_type = (struct file_system_type *[]) {
1148 &cifs_fs_type, &smb3_fs_type, NULL,
1149 };
1150
1151 for (; *fs_type; fs_type++) {
1152 iterate_supers_type(*fs_type, f, &sd);
1153 if (sd.sb) {
1154 /*
1155 * Grab an active reference in order to prevent automounts (DFS links)
1156 * of expiring and then freeing up our cifs superblock pointer while
1157 * we're doing failover.
1158 */
1159 cifs_sb_active(sd.sb);
1160 return sd.sb;
1161 }
1162 }
1163 pr_warn_once("%s: could not find dfs superblock\n", __func__);
1164 return ERR_PTR(-EINVAL);
1165 }
1166
__cifs_put_super(struct super_block * sb)1167 static void __cifs_put_super(struct super_block *sb)
1168 {
1169 if (!IS_ERR_OR_NULL(sb))
1170 cifs_sb_deactive(sb);
1171 }
1172
cifs_get_dfs_tcon_super(struct cifs_tcon * tcon)1173 struct super_block *cifs_get_dfs_tcon_super(struct cifs_tcon *tcon)
1174 {
1175 spin_lock(&tcon->tc_lock);
1176 if (!tcon->origin_fullpath) {
1177 spin_unlock(&tcon->tc_lock);
1178 return ERR_PTR(-ENOENT);
1179 }
1180 spin_unlock(&tcon->tc_lock);
1181 return __cifs_get_super(tcon_super_cb, tcon);
1182 }
1183
cifs_put_tcp_super(struct super_block * sb)1184 void cifs_put_tcp_super(struct super_block *sb)
1185 {
1186 __cifs_put_super(sb);
1187 }
1188
1189 #ifdef CONFIG_CIFS_DFS_UPCALL
match_target_ip(struct TCP_Server_Info * server,const char * host,size_t hostlen,bool * result)1190 int match_target_ip(struct TCP_Server_Info *server,
1191 const char *host, size_t hostlen,
1192 bool *result)
1193 {
1194 struct sockaddr_storage ss;
1195 int rc;
1196
1197 cifs_dbg(FYI, "%s: hostname=%.*s\n", __func__, (int)hostlen, host);
1198
1199 *result = false;
1200
1201 rc = dns_resolve_name(server->dns_dom, host, hostlen,
1202 (struct sockaddr *)&ss);
1203 if (rc < 0)
1204 return rc;
1205
1206 spin_lock(&server->srv_lock);
1207 *result = cifs_match_ipaddr((struct sockaddr *)&server->dstaddr, (struct sockaddr *)&ss);
1208 spin_unlock(&server->srv_lock);
1209 cifs_dbg(FYI, "%s: ip addresses matched: %s\n", __func__, str_yes_no(*result));
1210 return 0;
1211 }
1212
cifs_update_super_prepath(struct cifs_sb_info * cifs_sb,char * prefix)1213 int cifs_update_super_prepath(struct cifs_sb_info *cifs_sb, char *prefix)
1214 {
1215 int rc;
1216
1217 kfree(cifs_sb->prepath);
1218 cifs_sb->prepath = NULL;
1219
1220 if (prefix && *prefix) {
1221 cifs_sb->prepath = cifs_sanitize_prepath(prefix, GFP_ATOMIC);
1222 if (IS_ERR(cifs_sb->prepath)) {
1223 rc = PTR_ERR(cifs_sb->prepath);
1224 cifs_sb->prepath = NULL;
1225 return rc;
1226 }
1227 if (cifs_sb->prepath)
1228 convert_delimiter(cifs_sb->prepath, CIFS_DIR_SEP(cifs_sb));
1229 }
1230
1231 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
1232 return 0;
1233 }
1234
1235 /*
1236 * Handle weird Windows SMB server behaviour. It responds with
1237 * STATUS_OBJECT_NAME_INVALID code to SMB2 QUERY_INFO request for
1238 * "\<server>\<dfsname>\<linkpath>" DFS reference, where <dfsname> contains
1239 * non-ASCII unicode symbols.
1240 */
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)1241 int cifs_inval_name_dfs_link_error(const unsigned int xid,
1242 struct cifs_tcon *tcon,
1243 struct cifs_sb_info *cifs_sb,
1244 const char *full_path,
1245 bool *islink)
1246 {
1247 struct TCP_Server_Info *server = tcon->ses->server;
1248 struct cifs_ses *ses = tcon->ses;
1249 size_t len;
1250 char *path;
1251 char *ref_path;
1252
1253 *islink = false;
1254
1255 /*
1256 * Fast path - skip check when @full_path doesn't have a prefix path to
1257 * look up or tcon is not DFS.
1258 */
1259 if (strlen(full_path) < 2 || !cifs_sb ||
1260 (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_DFS) ||
1261 !is_tcon_dfs(tcon))
1262 return 0;
1263
1264 spin_lock(&server->srv_lock);
1265 if (!server->leaf_fullpath) {
1266 spin_unlock(&server->srv_lock);
1267 return 0;
1268 }
1269 spin_unlock(&server->srv_lock);
1270
1271 /*
1272 * Slow path - tcon is DFS and @full_path has prefix path, so attempt
1273 * to get a referral to figure out whether it is an DFS link.
1274 */
1275 len = strnlen(tcon->tree_name, MAX_TREE_SIZE + 1) + strlen(full_path) + 1;
1276 path = kmalloc(len, GFP_KERNEL);
1277 if (!path)
1278 return -ENOMEM;
1279
1280 scnprintf(path, len, "%s%s", tcon->tree_name, full_path);
1281 ref_path = dfs_cache_canonical_path(path + 1, cifs_sb->local_nls,
1282 cifs_remap(cifs_sb));
1283 kfree(path);
1284
1285 if (IS_ERR(ref_path)) {
1286 if (PTR_ERR(ref_path) != -EINVAL)
1287 return PTR_ERR(ref_path);
1288 } else {
1289 struct dfs_info3_param *refs = NULL;
1290 int num_refs = 0;
1291
1292 /*
1293 * XXX: we are not using dfs_cache_find() here because we might
1294 * end up filling all the DFS cache and thus potentially
1295 * removing cached DFS targets that the client would eventually
1296 * need during failover.
1297 */
1298 ses = CIFS_DFS_ROOT_SES(ses);
1299 if (ses->server->ops->get_dfs_refer &&
1300 !ses->server->ops->get_dfs_refer(xid, ses, ref_path, &refs,
1301 &num_refs, cifs_sb->local_nls,
1302 cifs_remap(cifs_sb)))
1303 *islink = refs[0].server_type == DFS_TYPE_LINK;
1304 free_dfs_info_array(refs, num_refs);
1305 kfree(ref_path);
1306 }
1307 return 0;
1308 }
1309 #endif
1310
cifs_wait_for_server_reconnect(struct TCP_Server_Info * server,bool retry)1311 int cifs_wait_for_server_reconnect(struct TCP_Server_Info *server, bool retry)
1312 {
1313 int timeout = 10;
1314 int rc;
1315
1316 spin_lock(&server->srv_lock);
1317 if (server->tcpStatus != CifsNeedReconnect) {
1318 spin_unlock(&server->srv_lock);
1319 return 0;
1320 }
1321 timeout *= server->nr_targets;
1322 spin_unlock(&server->srv_lock);
1323
1324 /*
1325 * Give demultiplex thread up to 10 seconds to each target available for
1326 * reconnect -- should be greater than cifs socket timeout which is 7
1327 * seconds.
1328 *
1329 * On "soft" mounts we wait once. Hard mounts keep retrying until
1330 * process is killed or server comes back on-line.
1331 */
1332 do {
1333 rc = wait_event_interruptible_timeout(server->response_q,
1334 (server->tcpStatus != CifsNeedReconnect),
1335 timeout * HZ);
1336 if (rc < 0) {
1337 cifs_dbg(FYI, "%s: aborting reconnect due to received signal\n",
1338 __func__);
1339 return -ERESTARTSYS;
1340 }
1341
1342 /* are we still trying to reconnect? */
1343 spin_lock(&server->srv_lock);
1344 if (server->tcpStatus != CifsNeedReconnect) {
1345 spin_unlock(&server->srv_lock);
1346 return 0;
1347 }
1348 spin_unlock(&server->srv_lock);
1349 } while (retry);
1350
1351 cifs_dbg(FYI, "%s: gave up waiting on reconnect\n", __func__);
1352 return -EHOSTDOWN;
1353 }
1354