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 #endif
25 #include "fs_context.h"
26
27 extern mempool_t *cifs_sm_req_poolp;
28 extern mempool_t *cifs_req_poolp;
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 ret_buf->status = CifsNew;
73 ++ret_buf->ses_count;
74 INIT_LIST_HEAD(&ret_buf->smb_ses_list);
75 INIT_LIST_HEAD(&ret_buf->tcon_list);
76 mutex_init(&ret_buf->session_mutex);
77 spin_lock_init(&ret_buf->iface_lock);
78 spin_lock_init(&ret_buf->chan_lock);
79 }
80 return ret_buf;
81 }
82
83 void
sesInfoFree(struct cifs_ses * buf_to_free)84 sesInfoFree(struct cifs_ses *buf_to_free)
85 {
86 if (buf_to_free == NULL) {
87 cifs_dbg(FYI, "Null buffer passed to sesInfoFree\n");
88 return;
89 }
90
91 atomic_dec(&sesInfoAllocCount);
92 kfree(buf_to_free->serverOS);
93 kfree(buf_to_free->serverDomain);
94 kfree(buf_to_free->serverNOS);
95 kfree_sensitive(buf_to_free->password);
96 kfree(buf_to_free->user_name);
97 kfree(buf_to_free->domainName);
98 kfree_sensitive(buf_to_free->auth_key.response);
99 kfree(buf_to_free->iface_list);
100 kfree_sensitive(buf_to_free);
101 }
102
103 struct cifs_tcon *
tconInfoAlloc(void)104 tconInfoAlloc(void)
105 {
106 struct cifs_tcon *ret_buf;
107
108 ret_buf = kzalloc(sizeof(*ret_buf), GFP_KERNEL);
109 if (!ret_buf)
110 return NULL;
111 ret_buf->crfid.fid = kzalloc(sizeof(*ret_buf->crfid.fid), GFP_KERNEL);
112 if (!ret_buf->crfid.fid) {
113 kfree(ret_buf);
114 return NULL;
115 }
116
117 atomic_inc(&tconInfoAllocCount);
118 ret_buf->tidStatus = CifsNew;
119 ++ret_buf->tc_count;
120 INIT_LIST_HEAD(&ret_buf->openFileList);
121 INIT_LIST_HEAD(&ret_buf->tcon_list);
122 spin_lock_init(&ret_buf->open_file_lock);
123 mutex_init(&ret_buf->crfid.fid_mutex);
124 spin_lock_init(&ret_buf->stat_lock);
125 atomic_set(&ret_buf->num_local_opens, 0);
126 atomic_set(&ret_buf->num_remote_opens, 0);
127
128 return ret_buf;
129 }
130
131 void
tconInfoFree(struct cifs_tcon * buf_to_free)132 tconInfoFree(struct cifs_tcon *buf_to_free)
133 {
134 if (buf_to_free == NULL) {
135 cifs_dbg(FYI, "Null buffer passed to tconInfoFree\n");
136 return;
137 }
138 atomic_dec(&tconInfoAllocCount);
139 kfree(buf_to_free->nativeFileSystem);
140 kfree_sensitive(buf_to_free->password);
141 kfree(buf_to_free->crfid.fid);
142 kfree(buf_to_free);
143 }
144
145 struct smb_hdr *
cifs_buf_get(void)146 cifs_buf_get(void)
147 {
148 struct smb_hdr *ret_buf = NULL;
149 /*
150 * SMB2 header is bigger than CIFS one - no problems to clean some
151 * more bytes for CIFS.
152 */
153 size_t buf_size = sizeof(struct smb2_sync_hdr);
154
155 /*
156 * We could use negotiated size instead of max_msgsize -
157 * but it may be more efficient to always alloc same size
158 * albeit slightly larger than necessary and maxbuffersize
159 * defaults to this and can not be bigger.
160 */
161 ret_buf = mempool_alloc(cifs_req_poolp, GFP_NOFS);
162
163 /* clear the first few header bytes */
164 /* for most paths, more is cleared in header_assemble */
165 memset(ret_buf, 0, buf_size + 3);
166 atomic_inc(&bufAllocCount);
167 #ifdef CONFIG_CIFS_STATS2
168 atomic_inc(&totBufAllocCount);
169 #endif /* CONFIG_CIFS_STATS2 */
170
171 return ret_buf;
172 }
173
174 void
cifs_buf_release(void * buf_to_free)175 cifs_buf_release(void *buf_to_free)
176 {
177 if (buf_to_free == NULL) {
178 /* cifs_dbg(FYI, "Null buffer passed to cifs_buf_release\n");*/
179 return;
180 }
181 mempool_free(buf_to_free, cifs_req_poolp);
182
183 atomic_dec(&bufAllocCount);
184 return;
185 }
186
187 struct smb_hdr *
cifs_small_buf_get(void)188 cifs_small_buf_get(void)
189 {
190 struct smb_hdr *ret_buf = NULL;
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 ret_buf = mempool_alloc(cifs_sm_req_poolp, GFP_NOFS);
197 /* No need to clear memory here, cleared in header assemble */
198 /* memset(ret_buf, 0, sizeof(struct smb_hdr) + 27);*/
199 atomic_inc(&smBufAllocCount);
200 #ifdef CONFIG_CIFS_STATS2
201 atomic_inc(&totSmBufAllocCount);
202 #endif /* CONFIG_CIFS_STATS2 */
203
204 return ret_buf;
205 }
206
207 void
cifs_small_buf_release(void * buf_to_free)208 cifs_small_buf_release(void *buf_to_free)
209 {
210
211 if (buf_to_free == NULL) {
212 cifs_dbg(FYI, "Null buffer passed to cifs_small_buf_release\n");
213 return;
214 }
215 mempool_free(buf_to_free, cifs_sm_req_poolp);
216
217 atomic_dec(&smBufAllocCount);
218 return;
219 }
220
221 void
free_rsp_buf(int resp_buftype,void * rsp)222 free_rsp_buf(int resp_buftype, void *rsp)
223 {
224 if (resp_buftype == CIFS_SMALL_BUFFER)
225 cifs_small_buf_release(rsp);
226 else if (resp_buftype == CIFS_LARGE_BUFFER)
227 cifs_buf_release(rsp);
228 }
229
230 /* NB: MID can not be set if treeCon not passed in, in that
231 case it is responsbility of caller to set the mid */
232 void
header_assemble(struct smb_hdr * buffer,char smb_command,const struct cifs_tcon * treeCon,int word_count)233 header_assemble(struct smb_hdr *buffer, char smb_command /* command */ ,
234 const struct cifs_tcon *treeCon, int word_count
235 /* length of fixed section (word count) in two byte units */)
236 {
237 char *temp = (char *) buffer;
238
239 memset(temp, 0, 256); /* bigger than MAX_CIFS_HDR_SIZE */
240
241 buffer->smb_buf_length = cpu_to_be32(
242 (2 * word_count) + sizeof(struct smb_hdr) -
243 4 /* RFC 1001 length field does not count */ +
244 2 /* for bcc field itself */) ;
245
246 buffer->Protocol[0] = 0xFF;
247 buffer->Protocol[1] = 'S';
248 buffer->Protocol[2] = 'M';
249 buffer->Protocol[3] = 'B';
250 buffer->Command = smb_command;
251 buffer->Flags = 0x00; /* case sensitive */
252 buffer->Flags2 = SMBFLG2_KNOWS_LONG_NAMES;
253 buffer->Pid = cpu_to_le16((__u16)current->tgid);
254 buffer->PidHigh = cpu_to_le16((__u16)(current->tgid >> 16));
255 if (treeCon) {
256 buffer->Tid = treeCon->tid;
257 if (treeCon->ses) {
258 if (treeCon->ses->capabilities & CAP_UNICODE)
259 buffer->Flags2 |= SMBFLG2_UNICODE;
260 if (treeCon->ses->capabilities & CAP_STATUS32)
261 buffer->Flags2 |= SMBFLG2_ERR_STATUS;
262
263 /* Uid is not converted */
264 buffer->Uid = treeCon->ses->Suid;
265 if (treeCon->ses->server)
266 buffer->Mid = get_next_mid(treeCon->ses->server);
267 }
268 if (treeCon->Flags & SMB_SHARE_IS_IN_DFS)
269 buffer->Flags2 |= SMBFLG2_DFS;
270 if (treeCon->nocase)
271 buffer->Flags |= SMBFLG_CASELESS;
272 if ((treeCon->ses) && (treeCon->ses->server))
273 if (treeCon->ses->server->sign)
274 buffer->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
275 }
276
277 /* endian conversion of flags is now done just before sending */
278 buffer->WordCount = (char) word_count;
279 return;
280 }
281
282 static int
check_smb_hdr(struct smb_hdr * smb)283 check_smb_hdr(struct smb_hdr *smb)
284 {
285 /* does it have the right SMB "signature" ? */
286 if (*(__le32 *) smb->Protocol != cpu_to_le32(0x424d53ff)) {
287 cifs_dbg(VFS, "Bad protocol string signature header 0x%x\n",
288 *(unsigned int *)smb->Protocol);
289 return 1;
290 }
291
292 /* if it's a response then accept */
293 if (smb->Flags & SMBFLG_RESPONSE)
294 return 0;
295
296 /* only one valid case where server sends us request */
297 if (smb->Command == SMB_COM_LOCKING_ANDX)
298 return 0;
299
300 cifs_dbg(VFS, "Server sent request, not response. mid=%u\n",
301 get_mid(smb));
302 return 1;
303 }
304
305 int
checkSMB(char * buf,unsigned int total_read,struct TCP_Server_Info * server)306 checkSMB(char *buf, unsigned int total_read, struct TCP_Server_Info *server)
307 {
308 struct smb_hdr *smb = (struct smb_hdr *)buf;
309 __u32 rfclen = be32_to_cpu(smb->smb_buf_length);
310 __u32 clc_len; /* calculated length */
311 cifs_dbg(FYI, "checkSMB Length: 0x%x, smb_buf_length: 0x%x\n",
312 total_read, rfclen);
313
314 /* is this frame too small to even get to a BCC? */
315 if (total_read < 2 + sizeof(struct smb_hdr)) {
316 if ((total_read >= sizeof(struct smb_hdr) - 1)
317 && (smb->Status.CifsError != 0)) {
318 /* it's an error return */
319 smb->WordCount = 0;
320 /* some error cases do not return wct and bcc */
321 return 0;
322 } else if ((total_read == sizeof(struct smb_hdr) + 1) &&
323 (smb->WordCount == 0)) {
324 char *tmp = (char *)smb;
325 /* Need to work around a bug in two servers here */
326 /* First, check if the part of bcc they sent was zero */
327 if (tmp[sizeof(struct smb_hdr)] == 0) {
328 /* some servers return only half of bcc
329 * on simple responses (wct, bcc both zero)
330 * in particular have seen this on
331 * ulogoffX and FindClose. This leaves
332 * one byte of bcc potentially unitialized
333 */
334 /* zero rest of bcc */
335 tmp[sizeof(struct smb_hdr)+1] = 0;
336 return 0;
337 }
338 cifs_dbg(VFS, "rcvd invalid byte count (bcc)\n");
339 } else {
340 cifs_dbg(VFS, "Length less than smb header size\n");
341 }
342 return -EIO;
343 } else if (total_read < sizeof(*smb) + 2 * smb->WordCount) {
344 cifs_dbg(VFS, "%s: can't read BCC due to invalid WordCount(%u)\n",
345 __func__, smb->WordCount);
346 return -EIO;
347 }
348
349 /* otherwise, there is enough to get to the BCC */
350 if (check_smb_hdr(smb))
351 return -EIO;
352 clc_len = smbCalcSize(smb, server);
353
354 if (4 + rfclen != total_read) {
355 cifs_dbg(VFS, "Length read does not match RFC1001 length %d\n",
356 rfclen);
357 return -EIO;
358 }
359
360 if (4 + rfclen != clc_len) {
361 __u16 mid = get_mid(smb);
362 /* check if bcc wrapped around for large read responses */
363 if ((rfclen > 64 * 1024) && (rfclen > clc_len)) {
364 /* check if lengths match mod 64K */
365 if (((4 + rfclen) & 0xFFFF) == (clc_len & 0xFFFF))
366 return 0; /* bcc wrapped */
367 }
368 cifs_dbg(FYI, "Calculated size %u vs length %u mismatch for mid=%u\n",
369 clc_len, 4 + rfclen, mid);
370
371 if (4 + rfclen < clc_len) {
372 cifs_dbg(VFS, "RFC1001 size %u smaller than SMB for mid=%u\n",
373 rfclen, mid);
374 return -EIO;
375 } else if (rfclen > clc_len + 512) {
376 /*
377 * Some servers (Windows XP in particular) send more
378 * data than the lengths in the SMB packet would
379 * indicate on certain calls (byte range locks and
380 * trans2 find first calls in particular). While the
381 * client can handle such a frame by ignoring the
382 * trailing data, we choose limit the amount of extra
383 * data to 512 bytes.
384 */
385 cifs_dbg(VFS, "RFC1001 size %u more than 512 bytes larger than SMB for mid=%u\n",
386 rfclen, mid);
387 return -EIO;
388 }
389 }
390 return 0;
391 }
392
393 bool
is_valid_oplock_break(char * buffer,struct TCP_Server_Info * srv)394 is_valid_oplock_break(char *buffer, struct TCP_Server_Info *srv)
395 {
396 struct smb_hdr *buf = (struct smb_hdr *)buffer;
397 struct smb_com_lock_req *pSMB = (struct smb_com_lock_req *)buf;
398 struct list_head *tmp, *tmp1, *tmp2;
399 struct cifs_ses *ses;
400 struct cifs_tcon *tcon;
401 struct cifsInodeInfo *pCifsInode;
402 struct cifsFileInfo *netfile;
403
404 cifs_dbg(FYI, "Checking for oplock break or dnotify response\n");
405 if ((pSMB->hdr.Command == SMB_COM_NT_TRANSACT) &&
406 (pSMB->hdr.Flags & SMBFLG_RESPONSE)) {
407 struct smb_com_transaction_change_notify_rsp *pSMBr =
408 (struct smb_com_transaction_change_notify_rsp *)buf;
409 struct file_notify_information *pnotify;
410 __u32 data_offset = 0;
411 size_t len = srv->total_read - sizeof(pSMBr->hdr.smb_buf_length);
412
413 if (get_bcc(buf) > sizeof(struct file_notify_information)) {
414 data_offset = le32_to_cpu(pSMBr->DataOffset);
415
416 if (data_offset >
417 len - sizeof(struct file_notify_information)) {
418 cifs_dbg(FYI, "Invalid data_offset %u\n",
419 data_offset);
420 return true;
421 }
422 pnotify = (struct file_notify_information *)
423 ((char *)&pSMBr->hdr.Protocol + data_offset);
424 cifs_dbg(FYI, "dnotify on %s Action: 0x%x\n",
425 pnotify->FileName, pnotify->Action);
426 /* cifs_dump_mem("Rcvd notify Data: ",buf,
427 sizeof(struct smb_hdr)+60); */
428 return true;
429 }
430 if (pSMBr->hdr.Status.CifsError) {
431 cifs_dbg(FYI, "notify err 0x%x\n",
432 pSMBr->hdr.Status.CifsError);
433 return true;
434 }
435 return false;
436 }
437 if (pSMB->hdr.Command != SMB_COM_LOCKING_ANDX)
438 return false;
439 if (pSMB->hdr.Flags & SMBFLG_RESPONSE) {
440 /* no sense logging error on invalid handle on oplock
441 break - harmless race between close request and oplock
442 break response is expected from time to time writing out
443 large dirty files cached on the client */
444 if ((NT_STATUS_INVALID_HANDLE) ==
445 le32_to_cpu(pSMB->hdr.Status.CifsError)) {
446 cifs_dbg(FYI, "Invalid handle on oplock break\n");
447 return true;
448 } else if (ERRbadfid ==
449 le16_to_cpu(pSMB->hdr.Status.DosError.Error)) {
450 return true;
451 } else {
452 return false; /* on valid oplock brk we get "request" */
453 }
454 }
455 if (pSMB->hdr.WordCount != 8)
456 return false;
457
458 cifs_dbg(FYI, "oplock type 0x%x level 0x%x\n",
459 pSMB->LockType, pSMB->OplockLevel);
460 if (!(pSMB->LockType & LOCKING_ANDX_OPLOCK_RELEASE))
461 return false;
462
463 /* look up tcon based on tid & uid */
464 spin_lock(&cifs_tcp_ses_lock);
465 list_for_each(tmp, &srv->smb_ses_list) {
466 ses = list_entry(tmp, struct cifs_ses, smb_ses_list);
467 list_for_each(tmp1, &ses->tcon_list) {
468 tcon = list_entry(tmp1, struct cifs_tcon, tcon_list);
469 if (tcon->tid != buf->Tid)
470 continue;
471
472 cifs_stats_inc(&tcon->stats.cifs_stats.num_oplock_brks);
473 spin_lock(&tcon->open_file_lock);
474 list_for_each(tmp2, &tcon->openFileList) {
475 netfile = list_entry(tmp2, struct cifsFileInfo,
476 tlist);
477 if (pSMB->Fid != netfile->fid.netfid)
478 continue;
479
480 cifs_dbg(FYI, "file id match, oplock break\n");
481 pCifsInode = CIFS_I(d_inode(netfile->dentry));
482
483 set_bit(CIFS_INODE_PENDING_OPLOCK_BREAK,
484 &pCifsInode->flags);
485
486 netfile->oplock_epoch = 0;
487 netfile->oplock_level = pSMB->OplockLevel;
488 netfile->oplock_break_cancelled = false;
489 cifs_queue_oplock_break(netfile);
490
491 spin_unlock(&tcon->open_file_lock);
492 spin_unlock(&cifs_tcp_ses_lock);
493 return true;
494 }
495 spin_unlock(&tcon->open_file_lock);
496 spin_unlock(&cifs_tcp_ses_lock);
497 cifs_dbg(FYI, "No matching file for oplock break\n");
498 return true;
499 }
500 }
501 spin_unlock(&cifs_tcp_ses_lock);
502 cifs_dbg(FYI, "Can not process oplock break for non-existent connection\n");
503 return true;
504 }
505
506 void
dump_smb(void * buf,int smb_buf_length)507 dump_smb(void *buf, int smb_buf_length)
508 {
509 if (traceSMB == 0)
510 return;
511
512 print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_NONE, 8, 2, buf,
513 smb_buf_length, true);
514 }
515
516 void
cifs_autodisable_serverino(struct cifs_sb_info * cifs_sb)517 cifs_autodisable_serverino(struct cifs_sb_info *cifs_sb)
518 {
519 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) {
520 struct cifs_tcon *tcon = NULL;
521
522 if (cifs_sb->master_tlink)
523 tcon = cifs_sb_master_tcon(cifs_sb);
524
525 cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM;
526 cifs_sb->mnt_cifs_serverino_autodisabled = true;
527 cifs_dbg(VFS, "Autodisabling the use of server inode numbers on %s\n",
528 tcon ? tcon->treeName : "new server");
529 cifs_dbg(VFS, "The server doesn't seem to support them properly or the files might be on different servers (DFS)\n");
530 cifs_dbg(VFS, "Hardlinks will not be recognized on this mount. Consider mounting with the \"noserverino\" option to silence this message.\n");
531
532 }
533 }
534
cifs_set_oplock_level(struct cifsInodeInfo * cinode,__u32 oplock)535 void cifs_set_oplock_level(struct cifsInodeInfo *cinode, __u32 oplock)
536 {
537 oplock &= 0xF;
538
539 if (oplock == OPLOCK_EXCLUSIVE) {
540 cinode->oplock = CIFS_CACHE_WRITE_FLG | CIFS_CACHE_READ_FLG;
541 cifs_dbg(FYI, "Exclusive Oplock granted on inode %p\n",
542 &cinode->vfs_inode);
543 } else if (oplock == OPLOCK_READ) {
544 cinode->oplock = CIFS_CACHE_READ_FLG;
545 cifs_dbg(FYI, "Level II Oplock granted on inode %p\n",
546 &cinode->vfs_inode);
547 } else
548 cinode->oplock = 0;
549 }
550
551 /*
552 * We wait for oplock breaks to be processed before we attempt to perform
553 * writes.
554 */
cifs_get_writer(struct cifsInodeInfo * cinode)555 int cifs_get_writer(struct cifsInodeInfo *cinode)
556 {
557 int rc;
558
559 start:
560 rc = wait_on_bit(&cinode->flags, CIFS_INODE_PENDING_OPLOCK_BREAK,
561 TASK_KILLABLE);
562 if (rc)
563 return rc;
564
565 spin_lock(&cinode->writers_lock);
566 if (!cinode->writers)
567 set_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags);
568 cinode->writers++;
569 /* Check to see if we have started servicing an oplock break */
570 if (test_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, &cinode->flags)) {
571 cinode->writers--;
572 if (cinode->writers == 0) {
573 clear_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags);
574 wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_WRITERS);
575 }
576 spin_unlock(&cinode->writers_lock);
577 goto start;
578 }
579 spin_unlock(&cinode->writers_lock);
580 return 0;
581 }
582
cifs_put_writer(struct cifsInodeInfo * cinode)583 void cifs_put_writer(struct cifsInodeInfo *cinode)
584 {
585 spin_lock(&cinode->writers_lock);
586 cinode->writers--;
587 if (cinode->writers == 0) {
588 clear_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags);
589 wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_WRITERS);
590 }
591 spin_unlock(&cinode->writers_lock);
592 }
593
594 /**
595 * cifs_queue_oplock_break - queue the oplock break handler for cfile
596 * @cfile: The file to break the oplock on
597 *
598 * This function is called from the demultiplex thread when it
599 * receives an oplock break for @cfile.
600 *
601 * Assumes the tcon->open_file_lock is held.
602 * Assumes cfile->file_info_lock is NOT held.
603 */
cifs_queue_oplock_break(struct cifsFileInfo * cfile)604 void cifs_queue_oplock_break(struct cifsFileInfo *cfile)
605 {
606 /*
607 * Bump the handle refcount now while we hold the
608 * open_file_lock to enforce the validity of it for the oplock
609 * break handler. The matching put is done at the end of the
610 * handler.
611 */
612 cifsFileInfo_get(cfile);
613
614 queue_work(cifsoplockd_wq, &cfile->oplock_break);
615 }
616
cifs_done_oplock_break(struct cifsInodeInfo * cinode)617 void cifs_done_oplock_break(struct cifsInodeInfo *cinode)
618 {
619 clear_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, &cinode->flags);
620 wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_OPLOCK_BREAK);
621 }
622
623 bool
backup_cred(struct cifs_sb_info * cifs_sb)624 backup_cred(struct cifs_sb_info *cifs_sb)
625 {
626 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPUID) {
627 if (uid_eq(cifs_sb->ctx->backupuid, current_fsuid()))
628 return true;
629 }
630 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPGID) {
631 if (in_group_p(cifs_sb->ctx->backupgid))
632 return true;
633 }
634
635 return false;
636 }
637
638 void
cifs_del_pending_open(struct cifs_pending_open * open)639 cifs_del_pending_open(struct cifs_pending_open *open)
640 {
641 spin_lock(&tlink_tcon(open->tlink)->open_file_lock);
642 list_del(&open->olist);
643 spin_unlock(&tlink_tcon(open->tlink)->open_file_lock);
644 }
645
646 void
cifs_add_pending_open_locked(struct cifs_fid * fid,struct tcon_link * tlink,struct cifs_pending_open * open)647 cifs_add_pending_open_locked(struct cifs_fid *fid, struct tcon_link *tlink,
648 struct cifs_pending_open *open)
649 {
650 memcpy(open->lease_key, fid->lease_key, SMB2_LEASE_KEY_SIZE);
651 open->oplock = CIFS_OPLOCK_NO_CHANGE;
652 open->tlink = tlink;
653 fid->pending_open = open;
654 list_add_tail(&open->olist, &tlink_tcon(tlink)->pending_opens);
655 }
656
657 void
cifs_add_pending_open(struct cifs_fid * fid,struct tcon_link * tlink,struct cifs_pending_open * open)658 cifs_add_pending_open(struct cifs_fid *fid, struct tcon_link *tlink,
659 struct cifs_pending_open *open)
660 {
661 spin_lock(&tlink_tcon(tlink)->open_file_lock);
662 cifs_add_pending_open_locked(fid, tlink, open);
663 spin_unlock(&tlink_tcon(open->tlink)->open_file_lock);
664 }
665
666 /*
667 * Critical section which runs after acquiring deferred_lock.
668 * As there is no reference count on cifs_deferred_close, pdclose
669 * should not be used outside deferred_lock.
670 */
671 bool
cifs_is_deferred_close(struct cifsFileInfo * cfile,struct cifs_deferred_close ** pdclose)672 cifs_is_deferred_close(struct cifsFileInfo *cfile, struct cifs_deferred_close **pdclose)
673 {
674 struct cifs_deferred_close *dclose;
675
676 list_for_each_entry(dclose, &CIFS_I(d_inode(cfile->dentry))->deferred_closes, dlist) {
677 if ((dclose->netfid == cfile->fid.netfid) &&
678 (dclose->persistent_fid == cfile->fid.persistent_fid) &&
679 (dclose->volatile_fid == cfile->fid.volatile_fid)) {
680 *pdclose = dclose;
681 return true;
682 }
683 }
684 return false;
685 }
686
687 /*
688 * Critical section which runs after acquiring deferred_lock.
689 */
690 void
cifs_add_deferred_close(struct cifsFileInfo * cfile,struct cifs_deferred_close * dclose)691 cifs_add_deferred_close(struct cifsFileInfo *cfile, struct cifs_deferred_close *dclose)
692 {
693 bool is_deferred = false;
694 struct cifs_deferred_close *pdclose;
695
696 is_deferred = cifs_is_deferred_close(cfile, &pdclose);
697 if (is_deferred) {
698 kfree(dclose);
699 return;
700 }
701
702 dclose->tlink = cfile->tlink;
703 dclose->netfid = cfile->fid.netfid;
704 dclose->persistent_fid = cfile->fid.persistent_fid;
705 dclose->volatile_fid = cfile->fid.volatile_fid;
706 list_add_tail(&dclose->dlist, &CIFS_I(d_inode(cfile->dentry))->deferred_closes);
707 }
708
709 /*
710 * Critical section which runs after acquiring deferred_lock.
711 */
712 void
cifs_del_deferred_close(struct cifsFileInfo * cfile)713 cifs_del_deferred_close(struct cifsFileInfo *cfile)
714 {
715 bool is_deferred = false;
716 struct cifs_deferred_close *dclose;
717
718 is_deferred = cifs_is_deferred_close(cfile, &dclose);
719 if (!is_deferred)
720 return;
721 list_del(&dclose->dlist);
722 kfree(dclose);
723 }
724
725 void
cifs_close_deferred_file(struct cifsInodeInfo * cifs_inode)726 cifs_close_deferred_file(struct cifsInodeInfo *cifs_inode)
727 {
728 struct cifsFileInfo *cfile = NULL;
729 struct file_list *tmp_list, *tmp_next_list;
730 struct list_head file_head;
731
732 if (cifs_inode == NULL)
733 return;
734
735 INIT_LIST_HEAD(&file_head);
736 spin_lock(&cifs_inode->open_file_lock);
737 list_for_each_entry(cfile, &cifs_inode->openFileList, flist) {
738 if (delayed_work_pending(&cfile->deferred)) {
739 if (cancel_delayed_work(&cfile->deferred)) {
740 spin_lock(&cifs_inode->deferred_lock);
741 cifs_del_deferred_close(cfile);
742 spin_unlock(&cifs_inode->deferred_lock);
743
744 tmp_list = kmalloc(sizeof(struct file_list), GFP_ATOMIC);
745 if (tmp_list == NULL)
746 break;
747 tmp_list->cfile = cfile;
748 list_add_tail(&tmp_list->list, &file_head);
749 }
750 }
751 }
752 spin_unlock(&cifs_inode->open_file_lock);
753
754 list_for_each_entry_safe(tmp_list, tmp_next_list, &file_head, list) {
755 _cifsFileInfo_put(tmp_list->cfile, false, false);
756 list_del(&tmp_list->list);
757 kfree(tmp_list);
758 }
759 }
760
761 void
cifs_close_all_deferred_files(struct cifs_tcon * tcon)762 cifs_close_all_deferred_files(struct cifs_tcon *tcon)
763 {
764 struct cifsFileInfo *cfile;
765 struct list_head *tmp;
766 struct file_list *tmp_list, *tmp_next_list;
767 struct list_head file_head;
768
769 INIT_LIST_HEAD(&file_head);
770 spin_lock(&tcon->open_file_lock);
771 list_for_each(tmp, &tcon->openFileList) {
772 cfile = list_entry(tmp, struct cifsFileInfo, tlist);
773 if (delayed_work_pending(&cfile->deferred)) {
774 if (cancel_delayed_work(&cfile->deferred)) {
775 spin_lock(&CIFS_I(d_inode(cfile->dentry))->deferred_lock);
776 cifs_del_deferred_close(cfile);
777 spin_unlock(&CIFS_I(d_inode(cfile->dentry))->deferred_lock);
778
779 tmp_list = kmalloc(sizeof(struct file_list), GFP_ATOMIC);
780 if (tmp_list == NULL)
781 break;
782 tmp_list->cfile = cfile;
783 list_add_tail(&tmp_list->list, &file_head);
784 }
785 }
786 }
787 spin_unlock(&tcon->open_file_lock);
788
789 list_for_each_entry_safe(tmp_list, tmp_next_list, &file_head, list) {
790 _cifsFileInfo_put(tmp_list->cfile, true, false);
791 list_del(&tmp_list->list);
792 kfree(tmp_list);
793 }
794 }
795 void
cifs_close_deferred_file_under_dentry(struct cifs_tcon * tcon,const char * path)796 cifs_close_deferred_file_under_dentry(struct cifs_tcon *tcon, const char *path)
797 {
798 struct cifsFileInfo *cfile;
799 struct list_head *tmp;
800 struct file_list *tmp_list, *tmp_next_list;
801 struct list_head file_head;
802 void *page;
803 const char *full_path;
804
805 INIT_LIST_HEAD(&file_head);
806 page = alloc_dentry_path();
807 spin_lock(&tcon->open_file_lock);
808 list_for_each(tmp, &tcon->openFileList) {
809 cfile = list_entry(tmp, struct cifsFileInfo, tlist);
810 full_path = build_path_from_dentry(cfile->dentry, page);
811 if (strstr(full_path, path)) {
812 if (delayed_work_pending(&cfile->deferred)) {
813 if (cancel_delayed_work(&cfile->deferred)) {
814 spin_lock(&CIFS_I(d_inode(cfile->dentry))->deferred_lock);
815 cifs_del_deferred_close(cfile);
816 spin_unlock(&CIFS_I(d_inode(cfile->dentry))->deferred_lock);
817
818 tmp_list = kmalloc(sizeof(struct file_list), GFP_ATOMIC);
819 if (tmp_list == NULL)
820 break;
821 tmp_list->cfile = cfile;
822 list_add_tail(&tmp_list->list, &file_head);
823 }
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 free_dentry_path(page);
835 }
836
837 /* parses DFS refferal V3 structure
838 * caller is responsible for freeing target_nodes
839 * returns:
840 * - on success - 0
841 * - on failure - errno
842 */
843 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)844 parse_dfs_referrals(struct get_dfs_referral_rsp *rsp, u32 rsp_size,
845 unsigned int *num_of_nodes,
846 struct dfs_info3_param **target_nodes,
847 const struct nls_table *nls_codepage, int remap,
848 const char *searchName, bool is_unicode)
849 {
850 int i, rc = 0;
851 char *data_end;
852 struct dfs_referral_level_3 *ref;
853
854 *num_of_nodes = le16_to_cpu(rsp->NumberOfReferrals);
855
856 if (*num_of_nodes < 1) {
857 cifs_dbg(VFS, "num_referrals: must be at least > 0, but we get num_referrals = %d\n",
858 *num_of_nodes);
859 rc = -EINVAL;
860 goto parse_DFS_referrals_exit;
861 }
862
863 ref = (struct dfs_referral_level_3 *) &(rsp->referrals);
864 if (ref->VersionNumber != cpu_to_le16(3)) {
865 cifs_dbg(VFS, "Referrals of V%d version are not supported, should be V3\n",
866 le16_to_cpu(ref->VersionNumber));
867 rc = -EINVAL;
868 goto parse_DFS_referrals_exit;
869 }
870
871 /* get the upper boundary of the resp buffer */
872 data_end = (char *)rsp + rsp_size;
873
874 cifs_dbg(FYI, "num_referrals: %d dfs flags: 0x%x ...\n",
875 *num_of_nodes, le32_to_cpu(rsp->DFSFlags));
876
877 *target_nodes = kcalloc(*num_of_nodes, sizeof(struct dfs_info3_param),
878 GFP_KERNEL);
879 if (*target_nodes == NULL) {
880 rc = -ENOMEM;
881 goto parse_DFS_referrals_exit;
882 }
883
884 /* collect necessary data from referrals */
885 for (i = 0; i < *num_of_nodes; i++) {
886 char *temp;
887 int max_len;
888 struct dfs_info3_param *node = (*target_nodes)+i;
889
890 node->flags = le32_to_cpu(rsp->DFSFlags);
891 if (is_unicode) {
892 __le16 *tmp = kmalloc(strlen(searchName)*2 + 2,
893 GFP_KERNEL);
894 if (tmp == NULL) {
895 rc = -ENOMEM;
896 goto parse_DFS_referrals_exit;
897 }
898 cifsConvertToUTF16((__le16 *) tmp, searchName,
899 PATH_MAX, nls_codepage, remap);
900 node->path_consumed = cifs_utf16_bytes(tmp,
901 le16_to_cpu(rsp->PathConsumed),
902 nls_codepage);
903 kfree(tmp);
904 } else
905 node->path_consumed = le16_to_cpu(rsp->PathConsumed);
906
907 node->server_type = le16_to_cpu(ref->ServerType);
908 node->ref_flag = le16_to_cpu(ref->ReferralEntryFlags);
909
910 /* copy DfsPath */
911 temp = (char *)ref + le16_to_cpu(ref->DfsPathOffset);
912 max_len = data_end - temp;
913 node->path_name = cifs_strndup_from_utf16(temp, max_len,
914 is_unicode, nls_codepage);
915 if (!node->path_name) {
916 rc = -ENOMEM;
917 goto parse_DFS_referrals_exit;
918 }
919
920 /* copy link target UNC */
921 temp = (char *)ref + le16_to_cpu(ref->NetworkAddressOffset);
922 max_len = data_end - temp;
923 node->node_name = cifs_strndup_from_utf16(temp, max_len,
924 is_unicode, nls_codepage);
925 if (!node->node_name) {
926 rc = -ENOMEM;
927 goto parse_DFS_referrals_exit;
928 }
929
930 node->ttl = le32_to_cpu(ref->TimeToLive);
931
932 ref++;
933 }
934
935 parse_DFS_referrals_exit:
936 if (rc) {
937 free_dfs_info_array(*target_nodes, *num_of_nodes);
938 *target_nodes = NULL;
939 *num_of_nodes = 0;
940 }
941 return rc;
942 }
943
944 struct cifs_aio_ctx *
cifs_aio_ctx_alloc(void)945 cifs_aio_ctx_alloc(void)
946 {
947 struct cifs_aio_ctx *ctx;
948
949 /*
950 * Must use kzalloc to initialize ctx->bv to NULL and ctx->direct_io
951 * to false so that we know when we have to unreference pages within
952 * cifs_aio_ctx_release()
953 */
954 ctx = kzalloc(sizeof(struct cifs_aio_ctx), GFP_KERNEL);
955 if (!ctx)
956 return NULL;
957
958 INIT_LIST_HEAD(&ctx->list);
959 mutex_init(&ctx->aio_mutex);
960 init_completion(&ctx->done);
961 kref_init(&ctx->refcount);
962 return ctx;
963 }
964
965 void
cifs_aio_ctx_release(struct kref * refcount)966 cifs_aio_ctx_release(struct kref *refcount)
967 {
968 struct cifs_aio_ctx *ctx = container_of(refcount,
969 struct cifs_aio_ctx, refcount);
970
971 cifsFileInfo_put(ctx->cfile);
972
973 /*
974 * ctx->bv is only set if setup_aio_ctx_iter() was call successfuly
975 * which means that iov_iter_get_pages() was a success and thus that
976 * we have taken reference on pages.
977 */
978 if (ctx->bv) {
979 unsigned i;
980
981 for (i = 0; i < ctx->npages; i++) {
982 if (ctx->should_dirty)
983 set_page_dirty(ctx->bv[i].bv_page);
984 put_page(ctx->bv[i].bv_page);
985 }
986 kvfree(ctx->bv);
987 }
988
989 kfree(ctx);
990 }
991
992 #define CIFS_AIO_KMALLOC_LIMIT (1024 * 1024)
993
994 int
setup_aio_ctx_iter(struct cifs_aio_ctx * ctx,struct iov_iter * iter,int rw)995 setup_aio_ctx_iter(struct cifs_aio_ctx *ctx, struct iov_iter *iter, int rw)
996 {
997 ssize_t rc;
998 unsigned int cur_npages;
999 unsigned int npages = 0;
1000 unsigned int i;
1001 size_t len;
1002 size_t count = iov_iter_count(iter);
1003 unsigned int saved_len;
1004 size_t start;
1005 unsigned int max_pages = iov_iter_npages(iter, INT_MAX);
1006 struct page **pages = NULL;
1007 struct bio_vec *bv = NULL;
1008
1009 if (iov_iter_is_kvec(iter)) {
1010 memcpy(&ctx->iter, iter, sizeof(*iter));
1011 ctx->len = count;
1012 iov_iter_advance(iter, count);
1013 return 0;
1014 }
1015
1016 if (array_size(max_pages, sizeof(*bv)) <= CIFS_AIO_KMALLOC_LIMIT)
1017 bv = kmalloc_array(max_pages, sizeof(*bv), GFP_KERNEL);
1018
1019 if (!bv) {
1020 bv = vmalloc(array_size(max_pages, sizeof(*bv)));
1021 if (!bv)
1022 return -ENOMEM;
1023 }
1024
1025 if (array_size(max_pages, sizeof(*pages)) <= CIFS_AIO_KMALLOC_LIMIT)
1026 pages = kmalloc_array(max_pages, sizeof(*pages), GFP_KERNEL);
1027
1028 if (!pages) {
1029 pages = vmalloc(array_size(max_pages, sizeof(*pages)));
1030 if (!pages) {
1031 kvfree(bv);
1032 return -ENOMEM;
1033 }
1034 }
1035
1036 saved_len = count;
1037
1038 while (count && npages < max_pages) {
1039 rc = iov_iter_get_pages(iter, pages, count, max_pages, &start);
1040 if (rc < 0) {
1041 cifs_dbg(VFS, "Couldn't get user pages (rc=%zd)\n", rc);
1042 break;
1043 }
1044
1045 if (rc > count) {
1046 cifs_dbg(VFS, "get pages rc=%zd more than %zu\n", rc,
1047 count);
1048 break;
1049 }
1050
1051 iov_iter_advance(iter, rc);
1052 count -= rc;
1053 rc += start;
1054 cur_npages = DIV_ROUND_UP(rc, PAGE_SIZE);
1055
1056 if (npages + cur_npages > max_pages) {
1057 cifs_dbg(VFS, "out of vec array capacity (%u vs %u)\n",
1058 npages + cur_npages, max_pages);
1059 break;
1060 }
1061
1062 for (i = 0; i < cur_npages; i++) {
1063 len = rc > PAGE_SIZE ? PAGE_SIZE : rc;
1064 bv[npages + i].bv_page = pages[i];
1065 bv[npages + i].bv_offset = start;
1066 bv[npages + i].bv_len = len - start;
1067 rc -= len;
1068 start = 0;
1069 }
1070
1071 npages += cur_npages;
1072 }
1073
1074 kvfree(pages);
1075 ctx->bv = bv;
1076 ctx->len = saved_len - count;
1077 ctx->npages = npages;
1078 iov_iter_bvec(&ctx->iter, rw, ctx->bv, npages, ctx->len);
1079 return 0;
1080 }
1081
1082 /**
1083 * cifs_alloc_hash - allocate hash and hash context together
1084 * @name: The name of the crypto hash algo
1085 * @shash: Where to put the pointer to the hash algo
1086 * @sdesc: Where to put the pointer to the hash descriptor
1087 *
1088 * The caller has to make sure @sdesc is initialized to either NULL or
1089 * a valid context. Both can be freed via cifs_free_hash().
1090 */
1091 int
cifs_alloc_hash(const char * name,struct crypto_shash ** shash,struct sdesc ** sdesc)1092 cifs_alloc_hash(const char *name,
1093 struct crypto_shash **shash, struct sdesc **sdesc)
1094 {
1095 int rc = 0;
1096 size_t size;
1097
1098 if (*sdesc != NULL)
1099 return 0;
1100
1101 *shash = crypto_alloc_shash(name, 0, 0);
1102 if (IS_ERR(*shash)) {
1103 cifs_dbg(VFS, "Could not allocate crypto %s\n", name);
1104 rc = PTR_ERR(*shash);
1105 *shash = NULL;
1106 *sdesc = NULL;
1107 return rc;
1108 }
1109
1110 size = sizeof(struct shash_desc) + crypto_shash_descsize(*shash);
1111 *sdesc = kmalloc(size, GFP_KERNEL);
1112 if (*sdesc == NULL) {
1113 cifs_dbg(VFS, "no memory left to allocate crypto %s\n", name);
1114 crypto_free_shash(*shash);
1115 *shash = NULL;
1116 return -ENOMEM;
1117 }
1118
1119 (*sdesc)->shash.tfm = *shash;
1120 return 0;
1121 }
1122
1123 /**
1124 * cifs_free_hash - free hash and hash context together
1125 * @shash: Where to find the pointer to the hash algo
1126 * @sdesc: Where to find the pointer to the hash descriptor
1127 *
1128 * Freeing a NULL hash or context is safe.
1129 */
1130 void
cifs_free_hash(struct crypto_shash ** shash,struct sdesc ** sdesc)1131 cifs_free_hash(struct crypto_shash **shash, struct sdesc **sdesc)
1132 {
1133 kfree(*sdesc);
1134 *sdesc = NULL;
1135 if (*shash)
1136 crypto_free_shash(*shash);
1137 *shash = NULL;
1138 }
1139
1140 /**
1141 * rqst_page_get_length - obtain the length and offset for a page in smb_rqst
1142 * @rqst: The request descriptor
1143 * @page: The index of the page to query
1144 * @len: Where to store the length for this page:
1145 * @offset: Where to store the offset for this page
1146 */
rqst_page_get_length(const struct smb_rqst * rqst,unsigned int page,unsigned int * len,unsigned int * offset)1147 void rqst_page_get_length(const struct smb_rqst *rqst, unsigned int page,
1148 unsigned int *len, unsigned int *offset)
1149 {
1150 *len = rqst->rq_pagesz;
1151 *offset = (page == 0) ? rqst->rq_offset : 0;
1152
1153 if (rqst->rq_npages == 1 || page == rqst->rq_npages-1)
1154 *len = rqst->rq_tailsz;
1155 else if (page == 0)
1156 *len = rqst->rq_pagesz - rqst->rq_offset;
1157 }
1158
extract_unc_hostname(const char * unc,const char ** h,size_t * len)1159 void extract_unc_hostname(const char *unc, const char **h, size_t *len)
1160 {
1161 const char *end;
1162
1163 /* skip initial slashes */
1164 while (*unc && (*unc == '\\' || *unc == '/'))
1165 unc++;
1166
1167 end = unc;
1168
1169 while (*end && !(*end == '\\' || *end == '/'))
1170 end++;
1171
1172 *h = unc;
1173 *len = end - unc;
1174 }
1175
1176 /**
1177 * copy_path_name - copy src path to dst, possibly truncating
1178 * @dst: The destination buffer
1179 * @src: The source name
1180 *
1181 * returns number of bytes written (including trailing nul)
1182 */
copy_path_name(char * dst,const char * src)1183 int copy_path_name(char *dst, const char *src)
1184 {
1185 int name_len;
1186
1187 /*
1188 * PATH_MAX includes nul, so if strlen(src) >= PATH_MAX it
1189 * will truncate and strlen(dst) will be PATH_MAX-1
1190 */
1191 name_len = strscpy(dst, src, PATH_MAX);
1192 if (WARN_ON_ONCE(name_len < 0))
1193 name_len = PATH_MAX-1;
1194
1195 /* we count the trailing nul */
1196 name_len++;
1197 return name_len;
1198 }
1199
1200 struct super_cb_data {
1201 void *data;
1202 struct super_block *sb;
1203 };
1204
tcp_super_cb(struct super_block * sb,void * arg)1205 static void tcp_super_cb(struct super_block *sb, void *arg)
1206 {
1207 struct super_cb_data *sd = arg;
1208 struct TCP_Server_Info *server = sd->data;
1209 struct cifs_sb_info *cifs_sb;
1210 struct cifs_tcon *tcon;
1211
1212 if (sd->sb)
1213 return;
1214
1215 cifs_sb = CIFS_SB(sb);
1216 tcon = cifs_sb_master_tcon(cifs_sb);
1217 if (tcon->ses->server == server)
1218 sd->sb = sb;
1219 }
1220
__cifs_get_super(void (* f)(struct super_block *,void *),void * data)1221 static struct super_block *__cifs_get_super(void (*f)(struct super_block *, void *),
1222 void *data)
1223 {
1224 struct super_cb_data sd = {
1225 .data = data,
1226 .sb = NULL,
1227 };
1228 struct file_system_type **fs_type = (struct file_system_type *[]) {
1229 &cifs_fs_type, &smb3_fs_type, NULL,
1230 };
1231
1232 for (; *fs_type; fs_type++) {
1233 iterate_supers_type(*fs_type, f, &sd);
1234 if (sd.sb) {
1235 /*
1236 * Grab an active reference in order to prevent automounts (DFS links)
1237 * of expiring and then freeing up our cifs superblock pointer while
1238 * we're doing failover.
1239 */
1240 cifs_sb_active(sd.sb);
1241 return sd.sb;
1242 }
1243 }
1244 return ERR_PTR(-EINVAL);
1245 }
1246
__cifs_put_super(struct super_block * sb)1247 static void __cifs_put_super(struct super_block *sb)
1248 {
1249 if (!IS_ERR_OR_NULL(sb))
1250 cifs_sb_deactive(sb);
1251 }
1252
cifs_get_tcp_super(struct TCP_Server_Info * server)1253 struct super_block *cifs_get_tcp_super(struct TCP_Server_Info *server)
1254 {
1255 return __cifs_get_super(tcp_super_cb, server);
1256 }
1257
cifs_put_tcp_super(struct super_block * sb)1258 void cifs_put_tcp_super(struct super_block *sb)
1259 {
1260 __cifs_put_super(sb);
1261 }
1262
1263 #ifdef CONFIG_CIFS_DFS_UPCALL
match_target_ip(struct TCP_Server_Info * server,const char * share,size_t share_len,bool * result)1264 int match_target_ip(struct TCP_Server_Info *server,
1265 const char *share, size_t share_len,
1266 bool *result)
1267 {
1268 int rc;
1269 char *target, *tip = NULL;
1270 struct sockaddr tipaddr;
1271
1272 *result = false;
1273
1274 target = kzalloc(share_len + 3, GFP_KERNEL);
1275 if (!target) {
1276 rc = -ENOMEM;
1277 goto out;
1278 }
1279
1280 scnprintf(target, share_len + 3, "\\\\%.*s", (int)share_len, share);
1281
1282 cifs_dbg(FYI, "%s: target name: %s\n", __func__, target + 2);
1283
1284 rc = dns_resolve_server_name_to_ip(target, &tip, NULL);
1285 if (rc < 0)
1286 goto out;
1287
1288 cifs_dbg(FYI, "%s: target ip: %s\n", __func__, tip);
1289
1290 if (!cifs_convert_address(&tipaddr, tip, strlen(tip))) {
1291 cifs_dbg(VFS, "%s: failed to convert target ip address\n",
1292 __func__);
1293 rc = -EINVAL;
1294 goto out;
1295 }
1296
1297 *result = cifs_match_ipaddr((struct sockaddr *)&server->dstaddr,
1298 &tipaddr);
1299 cifs_dbg(FYI, "%s: ip addresses match: %u\n", __func__, *result);
1300 rc = 0;
1301
1302 out:
1303 kfree(target);
1304 kfree(tip);
1305
1306 return rc;
1307 }
1308
cifs_update_super_prepath(struct cifs_sb_info * cifs_sb,char * prefix)1309 int cifs_update_super_prepath(struct cifs_sb_info *cifs_sb, char *prefix)
1310 {
1311 kfree(cifs_sb->prepath);
1312
1313 if (prefix && *prefix) {
1314 cifs_sb->prepath = cifs_sanitize_prepath(prefix, GFP_ATOMIC);
1315 if (!cifs_sb->prepath)
1316 return -ENOMEM;
1317
1318 convert_delimiter(cifs_sb->prepath, CIFS_DIR_SEP(cifs_sb));
1319 } else
1320 cifs_sb->prepath = NULL;
1321
1322 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
1323 return 0;
1324 }
1325 #endif
1326