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1/*
2 * fs/cifs/misc.c
3 *
4 * Copyright (C) International Business Machines Corp., 2002,2008
5 * Author(s): Steve French (sfrench@us.ibm.com)
6 *
7 * This library is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU Lesser General Public License as published
9 * by the Free Software Foundation; either version 2.1 of the License, or
10 * (at your option) any later version.
11 *
12 * This library is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
15 * the GNU Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public License
18 * along with this library; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 */
21
22#include <linux/slab.h>
23#include <linux/ctype.h>
24#include <linux/mempool.h>
25#include <linux/vmalloc.h>
26#include "cifspdu.h"
27#include "cifsglob.h"
28#include "cifsproto.h"
29#include "cifs_debug.h"
30#include "smberr.h"
31#include "nterr.h"
32#include "cifs_unicode.h"
33#include "smb2pdu.h"
34
35extern mempool_t *cifs_sm_req_poolp;
36extern mempool_t *cifs_req_poolp;
37
38/* The xid serves as a useful identifier for each incoming vfs request,
39 in a similar way to the mid which is useful to track each sent smb,
40 and CurrentXid can also provide a running counter (although it
41 will eventually wrap past zero) of the total vfs operations handled
42 since the cifs fs was mounted */
43
44unsigned int
45_get_xid(void)
46{
47 unsigned int xid;
48
49 spin_lock(&GlobalMid_Lock);
50 GlobalTotalActiveXid++;
51
52 /* keep high water mark for number of simultaneous ops in filesystem */
53 if (GlobalTotalActiveXid > GlobalMaxActiveXid)
54 GlobalMaxActiveXid = GlobalTotalActiveXid;
55 if (GlobalTotalActiveXid > 65000)
56 cifs_dbg(FYI, "warning: more than 65000 requests active\n");
57 xid = GlobalCurrentXid++;
58 spin_unlock(&GlobalMid_Lock);
59 return xid;
60}
61
62void
63_free_xid(unsigned int xid)
64{
65 spin_lock(&GlobalMid_Lock);
66 /* if (GlobalTotalActiveXid == 0)
67 BUG(); */
68 GlobalTotalActiveXid--;
69 spin_unlock(&GlobalMid_Lock);
70}
71
72struct cifs_ses *
73sesInfoAlloc(void)
74{
75 struct cifs_ses *ret_buf;
76
77 ret_buf = kzalloc(sizeof(struct cifs_ses), GFP_KERNEL);
78 if (ret_buf) {
79 atomic_inc(&sesInfoAllocCount);
80 ret_buf->status = CifsNew;
81 ++ret_buf->ses_count;
82 INIT_LIST_HEAD(&ret_buf->smb_ses_list);
83 INIT_LIST_HEAD(&ret_buf->tcon_list);
84 mutex_init(&ret_buf->session_mutex);
85 }
86 return ret_buf;
87}
88
89void
90sesInfoFree(struct cifs_ses *buf_to_free)
91{
92 if (buf_to_free == NULL) {
93 cifs_dbg(FYI, "Null buffer passed to sesInfoFree\n");
94 return;
95 }
96
97 atomic_dec(&sesInfoAllocCount);
98 kfree(buf_to_free->serverOS);
99 kfree(buf_to_free->serverDomain);
100 kfree(buf_to_free->serverNOS);
101 kzfree(buf_to_free->password);
102 kfree(buf_to_free->user_name);
103 kfree(buf_to_free->domainName);
104 kzfree(buf_to_free->auth_key.response);
105 kzfree(buf_to_free);
106}
107
108struct cifs_tcon *
109tconInfoAlloc(void)
110{
111 struct cifs_tcon *ret_buf;
112 ret_buf = kzalloc(sizeof(struct cifs_tcon), GFP_KERNEL);
113 if (ret_buf) {
114 atomic_inc(&tconInfoAllocCount);
115 ret_buf->tidStatus = CifsNew;
116 ++ret_buf->tc_count;
117 INIT_LIST_HEAD(&ret_buf->openFileList);
118 INIT_LIST_HEAD(&ret_buf->tcon_list);
119 spin_lock_init(&ret_buf->open_file_lock);
120#ifdef CONFIG_CIFS_STATS
121 spin_lock_init(&ret_buf->stat_lock);
122#endif
123 }
124 return ret_buf;
125}
126
127void
128tconInfoFree(struct cifs_tcon *buf_to_free)
129{
130 if (buf_to_free == NULL) {
131 cifs_dbg(FYI, "Null buffer passed to tconInfoFree\n");
132 return;
133 }
134 atomic_dec(&tconInfoAllocCount);
135 kfree(buf_to_free->nativeFileSystem);
136 kzfree(buf_to_free->password);
137 kfree(buf_to_free);
138}
139
140struct smb_hdr *
141cifs_buf_get(void)
142{
143 struct smb_hdr *ret_buf = NULL;
144 /*
145 * SMB2 header is bigger than CIFS one - no problems to clean some
146 * more bytes for CIFS.
147 */
148 size_t buf_size = sizeof(struct smb2_hdr);
149
150 /*
151 * We could use negotiated size instead of max_msgsize -
152 * but it may be more efficient to always alloc same size
153 * albeit slightly larger than necessary and maxbuffersize
154 * defaults to this and can not be bigger.
155 */
156 ret_buf = mempool_alloc(cifs_req_poolp, GFP_NOFS);
157
158 /* clear the first few header bytes */
159 /* for most paths, more is cleared in header_assemble */
160 memset(ret_buf, 0, buf_size + 3);
161 atomic_inc(&bufAllocCount);
162#ifdef CONFIG_CIFS_STATS2
163 atomic_inc(&totBufAllocCount);
164#endif /* CONFIG_CIFS_STATS2 */
165
166 return ret_buf;
167}
168
169void
170cifs_buf_release(void *buf_to_free)
171{
172 if (buf_to_free == NULL) {
173 /* cifs_dbg(FYI, "Null buffer passed to cifs_buf_release\n");*/
174 return;
175 }
176 mempool_free(buf_to_free, cifs_req_poolp);
177
178 atomic_dec(&bufAllocCount);
179 return;
180}
181
182struct smb_hdr *
183cifs_small_buf_get(void)
184{
185 struct smb_hdr *ret_buf = NULL;
186
187/* We could use negotiated size instead of max_msgsize -
188 but it may be more efficient to always alloc same size
189 albeit slightly larger than necessary and maxbuffersize
190 defaults to this and can not be bigger */
191 ret_buf = mempool_alloc(cifs_sm_req_poolp, GFP_NOFS);
192 /* No need to clear memory here, cleared in header assemble */
193 /* memset(ret_buf, 0, sizeof(struct smb_hdr) + 27);*/
194 atomic_inc(&smBufAllocCount);
195#ifdef CONFIG_CIFS_STATS2
196 atomic_inc(&totSmBufAllocCount);
197#endif /* CONFIG_CIFS_STATS2 */
198
199 return ret_buf;
200}
201
202void
203cifs_small_buf_release(void *buf_to_free)
204{
205
206 if (buf_to_free == NULL) {
207 cifs_dbg(FYI, "Null buffer passed to cifs_small_buf_release\n");
208 return;
209 }
210 mempool_free(buf_to_free, cifs_sm_req_poolp);
211
212 atomic_dec(&smBufAllocCount);
213 return;
214}
215
216void
217free_rsp_buf(int resp_buftype, void *rsp)
218{
219 if (resp_buftype == CIFS_SMALL_BUFFER)
220 cifs_small_buf_release(rsp);
221 else if (resp_buftype == CIFS_LARGE_BUFFER)
222 cifs_buf_release(rsp);
223}
224
225/* NB: MID can not be set if treeCon not passed in, in that
226 case it is responsbility of caller to set the mid */
227void
228header_assemble(struct smb_hdr *buffer, char smb_command /* command */ ,
229 const struct cifs_tcon *treeCon, int word_count
230 /* length of fixed section (word count) in two byte units */)
231{
232 char *temp = (char *) buffer;
233
234 memset(temp, 0, 256); /* bigger than MAX_CIFS_HDR_SIZE */
235
236 buffer->smb_buf_length = cpu_to_be32(
237 (2 * word_count) + sizeof(struct smb_hdr) -
238 4 /* RFC 1001 length field does not count */ +
239 2 /* for bcc field itself */) ;
240
241 buffer->Protocol[0] = 0xFF;
242 buffer->Protocol[1] = 'S';
243 buffer->Protocol[2] = 'M';
244 buffer->Protocol[3] = 'B';
245 buffer->Command = smb_command;
246 buffer->Flags = 0x00; /* case sensitive */
247 buffer->Flags2 = SMBFLG2_KNOWS_LONG_NAMES;
248 buffer->Pid = cpu_to_le16((__u16)current->tgid);
249 buffer->PidHigh = cpu_to_le16((__u16)(current->tgid >> 16));
250 if (treeCon) {
251 buffer->Tid = treeCon->tid;
252 if (treeCon->ses) {
253 if (treeCon->ses->capabilities & CAP_UNICODE)
254 buffer->Flags2 |= SMBFLG2_UNICODE;
255 if (treeCon->ses->capabilities & CAP_STATUS32)
256 buffer->Flags2 |= SMBFLG2_ERR_STATUS;
257
258 /* Uid is not converted */
259 buffer->Uid = treeCon->ses->Suid;
260 buffer->Mid = get_next_mid(treeCon->ses->server);
261 }
262 if (treeCon->Flags & SMB_SHARE_IS_IN_DFS)
263 buffer->Flags2 |= SMBFLG2_DFS;
264 if (treeCon->nocase)
265 buffer->Flags |= SMBFLG_CASELESS;
266 if ((treeCon->ses) && (treeCon->ses->server))
267 if (treeCon->ses->server->sign)
268 buffer->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
269 }
270
271/* endian conversion of flags is now done just before sending */
272 buffer->WordCount = (char) word_count;
273 return;
274}
275
276static int
277check_smb_hdr(struct smb_hdr *smb)
278{
279 /* does it have the right SMB "signature" ? */
280 if (*(__le32 *) smb->Protocol != cpu_to_le32(0x424d53ff)) {
281 cifs_dbg(VFS, "Bad protocol string signature header 0x%x\n",
282 *(unsigned int *)smb->Protocol);
283 return 1;
284 }
285
286 /* if it's a response then accept */
287 if (smb->Flags & SMBFLG_RESPONSE)
288 return 0;
289
290 /* only one valid case where server sends us request */
291 if (smb->Command == SMB_COM_LOCKING_ANDX)
292 return 0;
293
294 cifs_dbg(VFS, "Server sent request, not response. mid=%u\n",
295 get_mid(smb));
296 return 1;
297}
298
299int
300checkSMB(char *buf, unsigned int total_read, struct TCP_Server_Info *server)
301{
302 struct smb_hdr *smb = (struct smb_hdr *)buf;
303 __u32 rfclen = be32_to_cpu(smb->smb_buf_length);
304 __u32 clc_len; /* calculated length */
305 cifs_dbg(FYI, "checkSMB Length: 0x%x, smb_buf_length: 0x%x\n",
306 total_read, rfclen);
307
308 /* is this frame too small to even get to a BCC? */
309 if (total_read < 2 + sizeof(struct smb_hdr)) {
310 if ((total_read >= sizeof(struct smb_hdr) - 1)
311 && (smb->Status.CifsError != 0)) {
312 /* it's an error return */
313 smb->WordCount = 0;
314 /* some error cases do not return wct and bcc */
315 return 0;
316 } else if ((total_read == sizeof(struct smb_hdr) + 1) &&
317 (smb->WordCount == 0)) {
318 char *tmp = (char *)smb;
319 /* Need to work around a bug in two servers here */
320 /* First, check if the part of bcc they sent was zero */
321 if (tmp[sizeof(struct smb_hdr)] == 0) {
322 /* some servers return only half of bcc
323 * on simple responses (wct, bcc both zero)
324 * in particular have seen this on
325 * ulogoffX and FindClose. This leaves
326 * one byte of bcc potentially unitialized
327 */
328 /* zero rest of bcc */
329 tmp[sizeof(struct smb_hdr)+1] = 0;
330 return 0;
331 }
332 cifs_dbg(VFS, "rcvd invalid byte count (bcc)\n");
333 } else {
334 cifs_dbg(VFS, "Length less than smb header size\n");
335 }
336 return -EIO;
337 }
338
339 /* otherwise, there is enough to get to the BCC */
340 if (check_smb_hdr(smb))
341 return -EIO;
342 clc_len = smbCalcSize(smb);
343
344 if (4 + rfclen != total_read) {
345 cifs_dbg(VFS, "Length read does not match RFC1001 length %d\n",
346 rfclen);
347 return -EIO;
348 }
349
350 if (4 + rfclen != clc_len) {
351 __u16 mid = get_mid(smb);
352 /* check if bcc wrapped around for large read responses */
353 if ((rfclen > 64 * 1024) && (rfclen > clc_len)) {
354 /* check if lengths match mod 64K */
355 if (((4 + rfclen) & 0xFFFF) == (clc_len & 0xFFFF))
356 return 0; /* bcc wrapped */
357 }
358 cifs_dbg(FYI, "Calculated size %u vs length %u mismatch for mid=%u\n",
359 clc_len, 4 + rfclen, mid);
360
361 if (4 + rfclen < clc_len) {
362 cifs_dbg(VFS, "RFC1001 size %u smaller than SMB for mid=%u\n",
363 rfclen, mid);
364 return -EIO;
365 } else if (rfclen > clc_len + 512) {
366 /*
367 * Some servers (Windows XP in particular) send more
368 * data than the lengths in the SMB packet would
369 * indicate on certain calls (byte range locks and
370 * trans2 find first calls in particular). While the
371 * client can handle such a frame by ignoring the
372 * trailing data, we choose limit the amount of extra
373 * data to 512 bytes.
374 */
375 cifs_dbg(VFS, "RFC1001 size %u more than 512 bytes larger than SMB for mid=%u\n",
376 rfclen, mid);
377 return -EIO;
378 }
379 }
380 return 0;
381}
382
383bool
384is_valid_oplock_break(char *buffer, struct TCP_Server_Info *srv)
385{
386 struct smb_hdr *buf = (struct smb_hdr *)buffer;
387 struct smb_com_lock_req *pSMB = (struct smb_com_lock_req *)buf;
388 struct list_head *tmp, *tmp1, *tmp2;
389 struct cifs_ses *ses;
390 struct cifs_tcon *tcon;
391 struct cifsInodeInfo *pCifsInode;
392 struct cifsFileInfo *netfile;
393
394 cifs_dbg(FYI, "Checking for oplock break or dnotify response\n");
395 if ((pSMB->hdr.Command == SMB_COM_NT_TRANSACT) &&
396 (pSMB->hdr.Flags & SMBFLG_RESPONSE)) {
397 struct smb_com_transaction_change_notify_rsp *pSMBr =
398 (struct smb_com_transaction_change_notify_rsp *)buf;
399 struct file_notify_information *pnotify;
400 __u32 data_offset = 0;
401 if (get_bcc(buf) > sizeof(struct file_notify_information)) {
402 data_offset = le32_to_cpu(pSMBr->DataOffset);
403
404 pnotify = (struct file_notify_information *)
405 ((char *)&pSMBr->hdr.Protocol + data_offset);
406 cifs_dbg(FYI, "dnotify on %s Action: 0x%x\n",
407 pnotify->FileName, pnotify->Action);
408 /* cifs_dump_mem("Rcvd notify Data: ",buf,
409 sizeof(struct smb_hdr)+60); */
410 return true;
411 }
412 if (pSMBr->hdr.Status.CifsError) {
413 cifs_dbg(FYI, "notify err 0x%x\n",
414 pSMBr->hdr.Status.CifsError);
415 return true;
416 }
417 return false;
418 }
419 if (pSMB->hdr.Command != SMB_COM_LOCKING_ANDX)
420 return false;
421 if (pSMB->hdr.Flags & SMBFLG_RESPONSE) {
422 /* no sense logging error on invalid handle on oplock
423 break - harmless race between close request and oplock
424 break response is expected from time to time writing out
425 large dirty files cached on the client */
426 if ((NT_STATUS_INVALID_HANDLE) ==
427 le32_to_cpu(pSMB->hdr.Status.CifsError)) {
428 cifs_dbg(FYI, "invalid handle on oplock break\n");
429 return true;
430 } else if (ERRbadfid ==
431 le16_to_cpu(pSMB->hdr.Status.DosError.Error)) {
432 return true;
433 } else {
434 return false; /* on valid oplock brk we get "request" */
435 }
436 }
437 if (pSMB->hdr.WordCount != 8)
438 return false;
439
440 cifs_dbg(FYI, "oplock type 0x%x level 0x%x\n",
441 pSMB->LockType, pSMB->OplockLevel);
442 if (!(pSMB->LockType & LOCKING_ANDX_OPLOCK_RELEASE))
443 return false;
444
445 /* look up tcon based on tid & uid */
446 spin_lock(&cifs_tcp_ses_lock);
447 list_for_each(tmp, &srv->smb_ses_list) {
448 ses = list_entry(tmp, struct cifs_ses, smb_ses_list);
449 list_for_each(tmp1, &ses->tcon_list) {
450 tcon = list_entry(tmp1, struct cifs_tcon, tcon_list);
451 if (tcon->tid != buf->Tid)
452 continue;
453
454 cifs_stats_inc(&tcon->stats.cifs_stats.num_oplock_brks);
455 spin_lock(&tcon->open_file_lock);
456 list_for_each(tmp2, &tcon->openFileList) {
457 netfile = list_entry(tmp2, struct cifsFileInfo,
458 tlist);
459 if (pSMB->Fid != netfile->fid.netfid)
460 continue;
461
462 cifs_dbg(FYI, "file id match, oplock break\n");
463 pCifsInode = CIFS_I(d_inode(netfile->dentry));
464
465 set_bit(CIFS_INODE_PENDING_OPLOCK_BREAK,
466 &pCifsInode->flags);
467
468 /*
469 * Set flag if the server downgrades the oplock
470 * to L2 else clear.
471 */
472 if (pSMB->OplockLevel)
473 set_bit(
474 CIFS_INODE_DOWNGRADE_OPLOCK_TO_L2,
475 &pCifsInode->flags);
476 else
477 clear_bit(
478 CIFS_INODE_DOWNGRADE_OPLOCK_TO_L2,
479 &pCifsInode->flags);
480
481 queue_work(cifsoplockd_wq,
482 &netfile->oplock_break);
483 netfile->oplock_break_cancelled = false;
484
485 spin_unlock(&tcon->open_file_lock);
486 spin_unlock(&cifs_tcp_ses_lock);
487 return true;
488 }
489 spin_unlock(&tcon->open_file_lock);
490 spin_unlock(&cifs_tcp_ses_lock);
491 cifs_dbg(FYI, "No matching file for oplock break\n");
492 return true;
493 }
494 }
495 spin_unlock(&cifs_tcp_ses_lock);
496 cifs_dbg(FYI, "Can not process oplock break for non-existent connection\n");
497 return true;
498}
499
500void
501dump_smb(void *buf, int smb_buf_length)
502{
503 if (traceSMB == 0)
504 return;
505
506 print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_NONE, 8, 2, buf,
507 smb_buf_length, true);
508}
509
510void
511cifs_autodisable_serverino(struct cifs_sb_info *cifs_sb)
512{
513 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) {
514 cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM;
515 cifs_dbg(VFS, "Autodisabling the use of server inode numbers on %s. This server doesn't seem to support them properly. Hardlinks will not be recognized on this mount. Consider mounting with the \"noserverino\" option to silence this message.\n",
516 cifs_sb_master_tcon(cifs_sb)->treeName);
517 }
518}
519
520void cifs_set_oplock_level(struct cifsInodeInfo *cinode, __u32 oplock)
521{
522 oplock &= 0xF;
523
524 if (oplock == OPLOCK_EXCLUSIVE) {
525 cinode->oplock = CIFS_CACHE_WRITE_FLG | CIFS_CACHE_READ_FLG;
526 cifs_dbg(FYI, "Exclusive Oplock granted on inode %p\n",
527 &cinode->vfs_inode);
528 } else if (oplock == OPLOCK_READ) {
529 cinode->oplock = CIFS_CACHE_READ_FLG;
530 cifs_dbg(FYI, "Level II Oplock granted on inode %p\n",
531 &cinode->vfs_inode);
532 } else
533 cinode->oplock = 0;
534}
535
536/*
537 * We wait for oplock breaks to be processed before we attempt to perform
538 * writes.
539 */
540int cifs_get_writer(struct cifsInodeInfo *cinode)
541{
542 int rc;
543
544start:
545 rc = wait_on_bit(&cinode->flags, CIFS_INODE_PENDING_OPLOCK_BREAK,
546 TASK_KILLABLE);
547 if (rc)
548 return rc;
549
550 spin_lock(&cinode->writers_lock);
551 if (!cinode->writers)
552 set_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags);
553 cinode->writers++;
554 /* Check to see if we have started servicing an oplock break */
555 if (test_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, &cinode->flags)) {
556 cinode->writers--;
557 if (cinode->writers == 0) {
558 clear_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags);
559 wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_WRITERS);
560 }
561 spin_unlock(&cinode->writers_lock);
562 goto start;
563 }
564 spin_unlock(&cinode->writers_lock);
565 return 0;
566}
567
568void cifs_put_writer(struct cifsInodeInfo *cinode)
569{
570 spin_lock(&cinode->writers_lock);
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}
578
579void cifs_done_oplock_break(struct cifsInodeInfo *cinode)
580{
581 clear_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, &cinode->flags);
582 wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_OPLOCK_BREAK);
583}
584
585bool
586backup_cred(struct cifs_sb_info *cifs_sb)
587{
588 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPUID) {
589 if (uid_eq(cifs_sb->mnt_backupuid, current_fsuid()))
590 return true;
591 }
592 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPGID) {
593 if (in_group_p(cifs_sb->mnt_backupgid))
594 return true;
595 }
596
597 return false;
598}
599
600void
601cifs_del_pending_open(struct cifs_pending_open *open)
602{
603 spin_lock(&tlink_tcon(open->tlink)->open_file_lock);
604 list_del(&open->olist);
605 spin_unlock(&tlink_tcon(open->tlink)->open_file_lock);
606}
607
608void
609cifs_add_pending_open_locked(struct cifs_fid *fid, struct tcon_link *tlink,
610 struct cifs_pending_open *open)
611{
612 memcpy(open->lease_key, fid->lease_key, SMB2_LEASE_KEY_SIZE);
613 open->oplock = CIFS_OPLOCK_NO_CHANGE;
614 open->tlink = tlink;
615 fid->pending_open = open;
616 list_add_tail(&open->olist, &tlink_tcon(tlink)->pending_opens);
617}
618
619void
620cifs_add_pending_open(struct cifs_fid *fid, struct tcon_link *tlink,
621 struct cifs_pending_open *open)
622{
623 spin_lock(&tlink_tcon(tlink)->open_file_lock);
624 cifs_add_pending_open_locked(fid, tlink, open);
625 spin_unlock(&tlink_tcon(open->tlink)->open_file_lock);
626}
627
628/* parses DFS refferal V3 structure
629 * caller is responsible for freeing target_nodes
630 * returns:
631 * - on success - 0
632 * - on failure - errno
633 */
634int
635parse_dfs_referrals(struct get_dfs_referral_rsp *rsp, u32 rsp_size,
636 unsigned int *num_of_nodes,
637 struct dfs_info3_param **target_nodes,
638 const struct nls_table *nls_codepage, int remap,
639 const char *searchName, bool is_unicode)
640{
641 int i, rc = 0;
642 char *data_end;
643 struct dfs_referral_level_3 *ref;
644
645 *num_of_nodes = le16_to_cpu(rsp->NumberOfReferrals);
646
647 if (*num_of_nodes < 1) {
648 cifs_dbg(VFS, "num_referrals: must be at least > 0, but we get num_referrals = %d\n",
649 *num_of_nodes);
650 rc = -EINVAL;
651 goto parse_DFS_referrals_exit;
652 }
653
654 ref = (struct dfs_referral_level_3 *) &(rsp->referrals);
655 if (ref->VersionNumber != cpu_to_le16(3)) {
656 cifs_dbg(VFS, "Referrals of V%d version are not supported, should be V3\n",
657 le16_to_cpu(ref->VersionNumber));
658 rc = -EINVAL;
659 goto parse_DFS_referrals_exit;
660 }
661
662 /* get the upper boundary of the resp buffer */
663 data_end = (char *)rsp + rsp_size;
664
665 cifs_dbg(FYI, "num_referrals: %d dfs flags: 0x%x ...\n",
666 *num_of_nodes, le32_to_cpu(rsp->DFSFlags));
667
668 *target_nodes = kcalloc(*num_of_nodes, sizeof(struct dfs_info3_param),
669 GFP_KERNEL);
670 if (*target_nodes == NULL) {
671 rc = -ENOMEM;
672 goto parse_DFS_referrals_exit;
673 }
674
675 /* collect necessary data from referrals */
676 for (i = 0; i < *num_of_nodes; i++) {
677 char *temp;
678 int max_len;
679 struct dfs_info3_param *node = (*target_nodes)+i;
680
681 node->flags = le32_to_cpu(rsp->DFSFlags);
682 if (is_unicode) {
683 __le16 *tmp = kmalloc(strlen(searchName)*2 + 2,
684 GFP_KERNEL);
685 if (tmp == NULL) {
686 rc = -ENOMEM;
687 goto parse_DFS_referrals_exit;
688 }
689 cifsConvertToUTF16((__le16 *) tmp, searchName,
690 PATH_MAX, nls_codepage, remap);
691 node->path_consumed = cifs_utf16_bytes(tmp,
692 le16_to_cpu(rsp->PathConsumed),
693 nls_codepage);
694 kfree(tmp);
695 } else
696 node->path_consumed = le16_to_cpu(rsp->PathConsumed);
697
698 node->server_type = le16_to_cpu(ref->ServerType);
699 node->ref_flag = le16_to_cpu(ref->ReferralEntryFlags);
700
701 /* copy DfsPath */
702 temp = (char *)ref + le16_to_cpu(ref->DfsPathOffset);
703 max_len = data_end - temp;
704 node->path_name = cifs_strndup_from_utf16(temp, max_len,
705 is_unicode, nls_codepage);
706 if (!node->path_name) {
707 rc = -ENOMEM;
708 goto parse_DFS_referrals_exit;
709 }
710
711 /* copy link target UNC */
712 temp = (char *)ref + le16_to_cpu(ref->NetworkAddressOffset);
713 max_len = data_end - temp;
714 node->node_name = cifs_strndup_from_utf16(temp, max_len,
715 is_unicode, nls_codepage);
716 if (!node->node_name) {
717 rc = -ENOMEM;
718 goto parse_DFS_referrals_exit;
719 }
720
721 ref++;
722 }
723
724parse_DFS_referrals_exit:
725 if (rc) {
726 free_dfs_info_array(*target_nodes, *num_of_nodes);
727 *target_nodes = NULL;
728 *num_of_nodes = 0;
729 }
730 return rc;
731}
732
733struct cifs_aio_ctx *
734cifs_aio_ctx_alloc(void)
735{
736 struct cifs_aio_ctx *ctx;
737
738 ctx = kzalloc(sizeof(struct cifs_aio_ctx), GFP_KERNEL);
739 if (!ctx)
740 return NULL;
741
742 INIT_LIST_HEAD(&ctx->list);
743 mutex_init(&ctx->aio_mutex);
744 init_completion(&ctx->done);
745 kref_init(&ctx->refcount);
746 return ctx;
747}
748
749void
750cifs_aio_ctx_release(struct kref *refcount)
751{
752 struct cifs_aio_ctx *ctx = container_of(refcount,
753 struct cifs_aio_ctx, refcount);
754
755 cifsFileInfo_put(ctx->cfile);
756 kvfree(ctx->bv);
757 kfree(ctx);
758}
759
760#define CIFS_AIO_KMALLOC_LIMIT (1024 * 1024)
761
762int
763setup_aio_ctx_iter(struct cifs_aio_ctx *ctx, struct iov_iter *iter, int rw)
764{
765 ssize_t rc;
766 unsigned int cur_npages;
767 unsigned int npages = 0;
768 unsigned int i;
769 size_t len;
770 size_t count = iov_iter_count(iter);
771 unsigned int saved_len;
772 size_t start;
773 unsigned int max_pages = iov_iter_npages(iter, INT_MAX);
774 struct page **pages = NULL;
775 struct bio_vec *bv = NULL;
776
777 if (iter->type & ITER_KVEC) {
778 memcpy(&ctx->iter, iter, sizeof(struct iov_iter));
779 ctx->len = count;
780 iov_iter_advance(iter, count);
781 return 0;
782 }
783
784 if (max_pages * sizeof(struct bio_vec) <= CIFS_AIO_KMALLOC_LIMIT)
785 bv = kmalloc_array(max_pages, sizeof(struct bio_vec),
786 GFP_KERNEL);
787
788 if (!bv) {
789 bv = vmalloc(max_pages * sizeof(struct bio_vec));
790 if (!bv)
791 return -ENOMEM;
792 }
793
794 if (max_pages * sizeof(struct page *) <= CIFS_AIO_KMALLOC_LIMIT)
795 pages = kmalloc_array(max_pages, sizeof(struct page *),
796 GFP_KERNEL);
797
798 if (!pages) {
799 pages = vmalloc(max_pages * sizeof(struct page *));
800 if (!pages) {
801 kvfree(bv);
802 return -ENOMEM;
803 }
804 }
805
806 saved_len = count;
807
808 while (count && npages < max_pages) {
809 rc = iov_iter_get_pages(iter, pages, count, max_pages, &start);
810 if (rc < 0) {
811 cifs_dbg(VFS, "couldn't get user pages (rc=%zd)\n", rc);
812 break;
813 }
814
815 if (rc > count) {
816 cifs_dbg(VFS, "get pages rc=%zd more than %zu\n", rc,
817 count);
818 break;
819 }
820
821 iov_iter_advance(iter, rc);
822 count -= rc;
823 rc += start;
824 cur_npages = DIV_ROUND_UP(rc, PAGE_SIZE);
825
826 if (npages + cur_npages > max_pages) {
827 cifs_dbg(VFS, "out of vec array capacity (%u vs %u)\n",
828 npages + cur_npages, max_pages);
829 break;
830 }
831
832 for (i = 0; i < cur_npages; i++) {
833 len = rc > PAGE_SIZE ? PAGE_SIZE : rc;
834 bv[npages + i].bv_page = pages[i];
835 bv[npages + i].bv_offset = start;
836 bv[npages + i].bv_len = len - start;
837 rc -= len;
838 start = 0;
839 }
840
841 npages += cur_npages;
842 }
843
844 kvfree(pages);
845 ctx->bv = bv;
846 ctx->len = saved_len - count;
847 ctx->npages = npages;
848 iov_iter_bvec(&ctx->iter, ITER_BVEC | rw, ctx->bv, npages, ctx->len);
849 return 0;
850}
851
852/**
853 * cifs_alloc_hash - allocate hash and hash context together
854 *
855 * The caller has to make sure @sdesc is initialized to either NULL or
856 * a valid context. Both can be freed via cifs_free_hash().
857 */
858int
859cifs_alloc_hash(const char *name,
860 struct crypto_shash **shash, struct sdesc **sdesc)
861{
862 int rc = 0;
863 size_t size;
864
865 if (*sdesc != NULL)
866 return 0;
867
868 *shash = crypto_alloc_shash(name, 0, 0);
869 if (IS_ERR(*shash)) {
870 cifs_dbg(VFS, "could not allocate crypto %s\n", name);
871 rc = PTR_ERR(*shash);
872 *shash = NULL;
873 *sdesc = NULL;
874 return rc;
875 }
876
877 size = sizeof(struct shash_desc) + crypto_shash_descsize(*shash);
878 *sdesc = kmalloc(size, GFP_KERNEL);
879 if (*sdesc == NULL) {
880 cifs_dbg(VFS, "no memory left to allocate crypto %s\n", name);
881 crypto_free_shash(*shash);
882 *shash = NULL;
883 return -ENOMEM;
884 }
885
886 (*sdesc)->shash.tfm = *shash;
887 (*sdesc)->shash.flags = 0x0;
888 return 0;
889}
890
891/**
892 * cifs_free_hash - free hash and hash context together
893 *
894 * Freeing a NULL hash or context is safe.
895 */
896void
897cifs_free_hash(struct crypto_shash **shash, struct sdesc **sdesc)
898{
899 kfree(*sdesc);
900 *sdesc = NULL;
901 if (*shash)
902 crypto_free_shash(*shash);
903 *shash = NULL;
904}
1// SPDX-License-Identifier: LGPL-2.1
2/*
3 * fs/cifs/misc.c
4 *
5 * Copyright (C) International Business Machines Corp., 2002,2008
6 * Author(s): Steve French (sfrench@us.ibm.com)
7 *
8 */
9
10#include <linux/slab.h>
11#include <linux/ctype.h>
12#include <linux/mempool.h>
13#include <linux/vmalloc.h>
14#include "cifspdu.h"
15#include "cifsglob.h"
16#include "cifsproto.h"
17#include "cifs_debug.h"
18#include "smberr.h"
19#include "nterr.h"
20#include "cifs_unicode.h"
21#include "smb2pdu.h"
22#include "cifsfs.h"
23#ifdef CONFIG_CIFS_DFS_UPCALL
24#include "dns_resolve.h"
25#endif
26#include "fs_context.h"
27
28extern mempool_t *cifs_sm_req_poolp;
29extern mempool_t *cifs_req_poolp;
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
37unsigned int
38_get_xid(void)
39{
40 unsigned int xid;
41
42 spin_lock(&GlobalMid_Lock);
43 GlobalTotalActiveXid++;
44
45 /* keep high water mark for number of simultaneous ops in filesystem */
46 if (GlobalTotalActiveXid > GlobalMaxActiveXid)
47 GlobalMaxActiveXid = GlobalTotalActiveXid;
48 if (GlobalTotalActiveXid > 65000)
49 cifs_dbg(FYI, "warning: more than 65000 requests active\n");
50 xid = GlobalCurrentXid++;
51 spin_unlock(&GlobalMid_Lock);
52 return xid;
53}
54
55void
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
65struct cifs_ses *
66sesInfoAlloc(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 ret_buf->status = CifsNew;
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 }
80 return ret_buf;
81}
82
83void
84sesInfoFree(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
103struct cifs_tcon *
104tconInfoAlloc(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
131void
132tconInfoFree(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#ifdef CONFIG_CIFS_DFS_UPCALL
143 kfree(buf_to_free->dfs_path);
144#endif
145 kfree(buf_to_free);
146}
147
148struct smb_hdr *
149cifs_buf_get(void)
150{
151 struct smb_hdr *ret_buf = NULL;
152 /*
153 * SMB2 header is bigger than CIFS one - no problems to clean some
154 * more bytes for CIFS.
155 */
156 size_t buf_size = sizeof(struct smb2_sync_hdr);
157
158 /*
159 * We could use negotiated size instead of max_msgsize -
160 * but it may be more efficient to always alloc same size
161 * albeit slightly larger than necessary and maxbuffersize
162 * defaults to this and can not be bigger.
163 */
164 ret_buf = mempool_alloc(cifs_req_poolp, GFP_NOFS);
165
166 /* clear the first few header bytes */
167 /* for most paths, more is cleared in header_assemble */
168 memset(ret_buf, 0, buf_size + 3);
169 atomic_inc(&bufAllocCount);
170#ifdef CONFIG_CIFS_STATS2
171 atomic_inc(&totBufAllocCount);
172#endif /* CONFIG_CIFS_STATS2 */
173
174 return ret_buf;
175}
176
177void
178cifs_buf_release(void *buf_to_free)
179{
180 if (buf_to_free == NULL) {
181 /* cifs_dbg(FYI, "Null buffer passed to cifs_buf_release\n");*/
182 return;
183 }
184 mempool_free(buf_to_free, cifs_req_poolp);
185
186 atomic_dec(&bufAllocCount);
187 return;
188}
189
190struct smb_hdr *
191cifs_small_buf_get(void)
192{
193 struct smb_hdr *ret_buf = NULL;
194
195/* We could use negotiated size instead of max_msgsize -
196 but it may be more efficient to always alloc same size
197 albeit slightly larger than necessary and maxbuffersize
198 defaults to this and can not be bigger */
199 ret_buf = mempool_alloc(cifs_sm_req_poolp, GFP_NOFS);
200 /* No need to clear memory here, cleared in header assemble */
201 /* memset(ret_buf, 0, sizeof(struct smb_hdr) + 27);*/
202 atomic_inc(&smBufAllocCount);
203#ifdef CONFIG_CIFS_STATS2
204 atomic_inc(&totSmBufAllocCount);
205#endif /* CONFIG_CIFS_STATS2 */
206
207 return ret_buf;
208}
209
210void
211cifs_small_buf_release(void *buf_to_free)
212{
213
214 if (buf_to_free == NULL) {
215 cifs_dbg(FYI, "Null buffer passed to cifs_small_buf_release\n");
216 return;
217 }
218 mempool_free(buf_to_free, cifs_sm_req_poolp);
219
220 atomic_dec(&smBufAllocCount);
221 return;
222}
223
224void
225free_rsp_buf(int resp_buftype, void *rsp)
226{
227 if (resp_buftype == CIFS_SMALL_BUFFER)
228 cifs_small_buf_release(rsp);
229 else if (resp_buftype == CIFS_LARGE_BUFFER)
230 cifs_buf_release(rsp);
231}
232
233/* NB: MID can not be set if treeCon not passed in, in that
234 case it is responsbility of caller to set the mid */
235void
236header_assemble(struct smb_hdr *buffer, char smb_command /* command */ ,
237 const struct cifs_tcon *treeCon, int word_count
238 /* length of fixed section (word count) in two byte units */)
239{
240 char *temp = (char *) buffer;
241
242 memset(temp, 0, 256); /* bigger than MAX_CIFS_HDR_SIZE */
243
244 buffer->smb_buf_length = cpu_to_be32(
245 (2 * word_count) + sizeof(struct smb_hdr) -
246 4 /* RFC 1001 length field does not count */ +
247 2 /* for bcc field itself */) ;
248
249 buffer->Protocol[0] = 0xFF;
250 buffer->Protocol[1] = 'S';
251 buffer->Protocol[2] = 'M';
252 buffer->Protocol[3] = 'B';
253 buffer->Command = smb_command;
254 buffer->Flags = 0x00; /* case sensitive */
255 buffer->Flags2 = SMBFLG2_KNOWS_LONG_NAMES;
256 buffer->Pid = cpu_to_le16((__u16)current->tgid);
257 buffer->PidHigh = cpu_to_le16((__u16)(current->tgid >> 16));
258 if (treeCon) {
259 buffer->Tid = treeCon->tid;
260 if (treeCon->ses) {
261 if (treeCon->ses->capabilities & CAP_UNICODE)
262 buffer->Flags2 |= SMBFLG2_UNICODE;
263 if (treeCon->ses->capabilities & CAP_STATUS32)
264 buffer->Flags2 |= SMBFLG2_ERR_STATUS;
265
266 /* Uid is not converted */
267 buffer->Uid = treeCon->ses->Suid;
268 buffer->Mid = get_next_mid(treeCon->ses->server);
269 }
270 if (treeCon->Flags & SMB_SHARE_IS_IN_DFS)
271 buffer->Flags2 |= SMBFLG2_DFS;
272 if (treeCon->nocase)
273 buffer->Flags |= SMBFLG_CASELESS;
274 if ((treeCon->ses) && (treeCon->ses->server))
275 if (treeCon->ses->server->sign)
276 buffer->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
277 }
278
279/* endian conversion of flags is now done just before sending */
280 buffer->WordCount = (char) word_count;
281 return;
282}
283
284static int
285check_smb_hdr(struct smb_hdr *smb)
286{
287 /* does it have the right SMB "signature" ? */
288 if (*(__le32 *) smb->Protocol != cpu_to_le32(0x424d53ff)) {
289 cifs_dbg(VFS, "Bad protocol string signature header 0x%x\n",
290 *(unsigned int *)smb->Protocol);
291 return 1;
292 }
293
294 /* if it's a response then accept */
295 if (smb->Flags & SMBFLG_RESPONSE)
296 return 0;
297
298 /* only one valid case where server sends us request */
299 if (smb->Command == SMB_COM_LOCKING_ANDX)
300 return 0;
301
302 cifs_dbg(VFS, "Server sent request, not response. mid=%u\n",
303 get_mid(smb));
304 return 1;
305}
306
307int
308checkSMB(char *buf, unsigned int total_read, struct TCP_Server_Info *server)
309{
310 struct smb_hdr *smb = (struct smb_hdr *)buf;
311 __u32 rfclen = be32_to_cpu(smb->smb_buf_length);
312 __u32 clc_len; /* calculated length */
313 cifs_dbg(FYI, "checkSMB Length: 0x%x, smb_buf_length: 0x%x\n",
314 total_read, rfclen);
315
316 /* is this frame too small to even get to a BCC? */
317 if (total_read < 2 + sizeof(struct smb_hdr)) {
318 if ((total_read >= sizeof(struct smb_hdr) - 1)
319 && (smb->Status.CifsError != 0)) {
320 /* it's an error return */
321 smb->WordCount = 0;
322 /* some error cases do not return wct and bcc */
323 return 0;
324 } else if ((total_read == sizeof(struct smb_hdr) + 1) &&
325 (smb->WordCount == 0)) {
326 char *tmp = (char *)smb;
327 /* Need to work around a bug in two servers here */
328 /* First, check if the part of bcc they sent was zero */
329 if (tmp[sizeof(struct smb_hdr)] == 0) {
330 /* some servers return only half of bcc
331 * on simple responses (wct, bcc both zero)
332 * in particular have seen this on
333 * ulogoffX and FindClose. This leaves
334 * one byte of bcc potentially unitialized
335 */
336 /* zero rest of bcc */
337 tmp[sizeof(struct smb_hdr)+1] = 0;
338 return 0;
339 }
340 cifs_dbg(VFS, "rcvd invalid byte count (bcc)\n");
341 } else {
342 cifs_dbg(VFS, "Length less than smb header size\n");
343 }
344 return -EIO;
345 }
346
347 /* otherwise, there is enough to get to the BCC */
348 if (check_smb_hdr(smb))
349 return -EIO;
350 clc_len = smbCalcSize(smb, server);
351
352 if (4 + rfclen != total_read) {
353 cifs_dbg(VFS, "Length read does not match RFC1001 length %d\n",
354 rfclen);
355 return -EIO;
356 }
357
358 if (4 + rfclen != clc_len) {
359 __u16 mid = get_mid(smb);
360 /* check if bcc wrapped around for large read responses */
361 if ((rfclen > 64 * 1024) && (rfclen > clc_len)) {
362 /* check if lengths match mod 64K */
363 if (((4 + rfclen) & 0xFFFF) == (clc_len & 0xFFFF))
364 return 0; /* bcc wrapped */
365 }
366 cifs_dbg(FYI, "Calculated size %u vs length %u mismatch for mid=%u\n",
367 clc_len, 4 + rfclen, mid);
368
369 if (4 + rfclen < clc_len) {
370 cifs_dbg(VFS, "RFC1001 size %u smaller than SMB for mid=%u\n",
371 rfclen, mid);
372 return -EIO;
373 } else if (rfclen > clc_len + 512) {
374 /*
375 * Some servers (Windows XP in particular) send more
376 * data than the lengths in the SMB packet would
377 * indicate on certain calls (byte range locks and
378 * trans2 find first calls in particular). While the
379 * client can handle such a frame by ignoring the
380 * trailing data, we choose limit the amount of extra
381 * data to 512 bytes.
382 */
383 cifs_dbg(VFS, "RFC1001 size %u more than 512 bytes larger than SMB for mid=%u\n",
384 rfclen, mid);
385 return -EIO;
386 }
387 }
388 return 0;
389}
390
391bool
392is_valid_oplock_break(char *buffer, struct TCP_Server_Info *srv)
393{
394 struct smb_hdr *buf = (struct smb_hdr *)buffer;
395 struct smb_com_lock_req *pSMB = (struct smb_com_lock_req *)buf;
396 struct list_head *tmp, *tmp1, *tmp2;
397 struct cifs_ses *ses;
398 struct cifs_tcon *tcon;
399 struct cifsInodeInfo *pCifsInode;
400 struct cifsFileInfo *netfile;
401
402 cifs_dbg(FYI, "Checking for oplock break or dnotify response\n");
403 if ((pSMB->hdr.Command == SMB_COM_NT_TRANSACT) &&
404 (pSMB->hdr.Flags & SMBFLG_RESPONSE)) {
405 struct smb_com_transaction_change_notify_rsp *pSMBr =
406 (struct smb_com_transaction_change_notify_rsp *)buf;
407 struct file_notify_information *pnotify;
408 __u32 data_offset = 0;
409 size_t len = srv->total_read - sizeof(pSMBr->hdr.smb_buf_length);
410
411 if (get_bcc(buf) > sizeof(struct file_notify_information)) {
412 data_offset = le32_to_cpu(pSMBr->DataOffset);
413
414 if (data_offset >
415 len - sizeof(struct file_notify_information)) {
416 cifs_dbg(FYI, "Invalid data_offset %u\n",
417 data_offset);
418 return true;
419 }
420 pnotify = (struct file_notify_information *)
421 ((char *)&pSMBr->hdr.Protocol + data_offset);
422 cifs_dbg(FYI, "dnotify on %s Action: 0x%x\n",
423 pnotify->FileName, pnotify->Action);
424 /* cifs_dump_mem("Rcvd notify Data: ",buf,
425 sizeof(struct smb_hdr)+60); */
426 return true;
427 }
428 if (pSMBr->hdr.Status.CifsError) {
429 cifs_dbg(FYI, "notify err 0x%x\n",
430 pSMBr->hdr.Status.CifsError);
431 return true;
432 }
433 return false;
434 }
435 if (pSMB->hdr.Command != SMB_COM_LOCKING_ANDX)
436 return false;
437 if (pSMB->hdr.Flags & SMBFLG_RESPONSE) {
438 /* no sense logging error on invalid handle on oplock
439 break - harmless race between close request and oplock
440 break response is expected from time to time writing out
441 large dirty files cached on the client */
442 if ((NT_STATUS_INVALID_HANDLE) ==
443 le32_to_cpu(pSMB->hdr.Status.CifsError)) {
444 cifs_dbg(FYI, "Invalid handle on oplock break\n");
445 return true;
446 } else if (ERRbadfid ==
447 le16_to_cpu(pSMB->hdr.Status.DosError.Error)) {
448 return true;
449 } else {
450 return false; /* on valid oplock brk we get "request" */
451 }
452 }
453 if (pSMB->hdr.WordCount != 8)
454 return false;
455
456 cifs_dbg(FYI, "oplock type 0x%x level 0x%x\n",
457 pSMB->LockType, pSMB->OplockLevel);
458 if (!(pSMB->LockType & LOCKING_ANDX_OPLOCK_RELEASE))
459 return false;
460
461 /* look up tcon based on tid & uid */
462 spin_lock(&cifs_tcp_ses_lock);
463 list_for_each(tmp, &srv->smb_ses_list) {
464 ses = list_entry(tmp, struct cifs_ses, smb_ses_list);
465 list_for_each(tmp1, &ses->tcon_list) {
466 tcon = list_entry(tmp1, struct cifs_tcon, tcon_list);
467 if (tcon->tid != buf->Tid)
468 continue;
469
470 cifs_stats_inc(&tcon->stats.cifs_stats.num_oplock_brks);
471 spin_lock(&tcon->open_file_lock);
472 list_for_each(tmp2, &tcon->openFileList) {
473 netfile = list_entry(tmp2, struct cifsFileInfo,
474 tlist);
475 if (pSMB->Fid != netfile->fid.netfid)
476 continue;
477
478 cifs_dbg(FYI, "file id match, oplock break\n");
479 pCifsInode = CIFS_I(d_inode(netfile->dentry));
480
481 set_bit(CIFS_INODE_PENDING_OPLOCK_BREAK,
482 &pCifsInode->flags);
483
484 netfile->oplock_epoch = 0;
485 netfile->oplock_level = pSMB->OplockLevel;
486 netfile->oplock_break_cancelled = false;
487 cifs_queue_oplock_break(netfile);
488
489 spin_unlock(&tcon->open_file_lock);
490 spin_unlock(&cifs_tcp_ses_lock);
491 return true;
492 }
493 spin_unlock(&tcon->open_file_lock);
494 spin_unlock(&cifs_tcp_ses_lock);
495 cifs_dbg(FYI, "No matching file for oplock break\n");
496 return true;
497 }
498 }
499 spin_unlock(&cifs_tcp_ses_lock);
500 cifs_dbg(FYI, "Can not process oplock break for non-existent connection\n");
501 return true;
502}
503
504void
505dump_smb(void *buf, int smb_buf_length)
506{
507 if (traceSMB == 0)
508 return;
509
510 print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_NONE, 8, 2, buf,
511 smb_buf_length, true);
512}
513
514void
515cifs_autodisable_serverino(struct cifs_sb_info *cifs_sb)
516{
517 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) {
518 struct cifs_tcon *tcon = NULL;
519
520 if (cifs_sb->master_tlink)
521 tcon = cifs_sb_master_tcon(cifs_sb);
522
523 cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM;
524 cifs_sb->mnt_cifs_serverino_autodisabled = true;
525 cifs_dbg(VFS, "Autodisabling the use of server inode numbers on %s\n",
526 tcon ? tcon->treeName : "new server");
527 cifs_dbg(VFS, "The server doesn't seem to support them properly or the files might be on different servers (DFS)\n");
528 cifs_dbg(VFS, "Hardlinks will not be recognized on this mount. Consider mounting with the \"noserverino\" option to silence this message.\n");
529
530 }
531}
532
533void cifs_set_oplock_level(struct cifsInodeInfo *cinode, __u32 oplock)
534{
535 oplock &= 0xF;
536
537 if (oplock == OPLOCK_EXCLUSIVE) {
538 cinode->oplock = CIFS_CACHE_WRITE_FLG | CIFS_CACHE_READ_FLG;
539 cifs_dbg(FYI, "Exclusive Oplock granted on inode %p\n",
540 &cinode->vfs_inode);
541 } else if (oplock == OPLOCK_READ) {
542 cinode->oplock = CIFS_CACHE_READ_FLG;
543 cifs_dbg(FYI, "Level II Oplock granted on inode %p\n",
544 &cinode->vfs_inode);
545 } else
546 cinode->oplock = 0;
547}
548
549/*
550 * We wait for oplock breaks to be processed before we attempt to perform
551 * writes.
552 */
553int cifs_get_writer(struct cifsInodeInfo *cinode)
554{
555 int rc;
556
557start:
558 rc = wait_on_bit(&cinode->flags, CIFS_INODE_PENDING_OPLOCK_BREAK,
559 TASK_KILLABLE);
560 if (rc)
561 return rc;
562
563 spin_lock(&cinode->writers_lock);
564 if (!cinode->writers)
565 set_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags);
566 cinode->writers++;
567 /* Check to see if we have started servicing an oplock break */
568 if (test_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, &cinode->flags)) {
569 cinode->writers--;
570 if (cinode->writers == 0) {
571 clear_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags);
572 wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_WRITERS);
573 }
574 spin_unlock(&cinode->writers_lock);
575 goto start;
576 }
577 spin_unlock(&cinode->writers_lock);
578 return 0;
579}
580
581void cifs_put_writer(struct cifsInodeInfo *cinode)
582{
583 spin_lock(&cinode->writers_lock);
584 cinode->writers--;
585 if (cinode->writers == 0) {
586 clear_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags);
587 wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_WRITERS);
588 }
589 spin_unlock(&cinode->writers_lock);
590}
591
592/**
593 * cifs_queue_oplock_break - queue the oplock break handler for cfile
594 *
595 * This function is called from the demultiplex thread when it
596 * receives an oplock break for @cfile.
597 *
598 * Assumes the tcon->open_file_lock is held.
599 * Assumes cfile->file_info_lock is NOT held.
600 */
601void cifs_queue_oplock_break(struct cifsFileInfo *cfile)
602{
603 /*
604 * Bump the handle refcount now while we hold the
605 * open_file_lock to enforce the validity of it for the oplock
606 * break handler. The matching put is done at the end of the
607 * handler.
608 */
609 cifsFileInfo_get(cfile);
610
611 queue_work(cifsoplockd_wq, &cfile->oplock_break);
612}
613
614void cifs_done_oplock_break(struct cifsInodeInfo *cinode)
615{
616 clear_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, &cinode->flags);
617 wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_OPLOCK_BREAK);
618}
619
620bool
621backup_cred(struct cifs_sb_info *cifs_sb)
622{
623 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPUID) {
624 if (uid_eq(cifs_sb->ctx->backupuid, current_fsuid()))
625 return true;
626 }
627 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPGID) {
628 if (in_group_p(cifs_sb->ctx->backupgid))
629 return true;
630 }
631
632 return false;
633}
634
635void
636cifs_del_pending_open(struct cifs_pending_open *open)
637{
638 spin_lock(&tlink_tcon(open->tlink)->open_file_lock);
639 list_del(&open->olist);
640 spin_unlock(&tlink_tcon(open->tlink)->open_file_lock);
641}
642
643void
644cifs_add_pending_open_locked(struct cifs_fid *fid, struct tcon_link *tlink,
645 struct cifs_pending_open *open)
646{
647 memcpy(open->lease_key, fid->lease_key, SMB2_LEASE_KEY_SIZE);
648 open->oplock = CIFS_OPLOCK_NO_CHANGE;
649 open->tlink = tlink;
650 fid->pending_open = open;
651 list_add_tail(&open->olist, &tlink_tcon(tlink)->pending_opens);
652}
653
654void
655cifs_add_pending_open(struct cifs_fid *fid, struct tcon_link *tlink,
656 struct cifs_pending_open *open)
657{
658 spin_lock(&tlink_tcon(tlink)->open_file_lock);
659 cifs_add_pending_open_locked(fid, tlink, open);
660 spin_unlock(&tlink_tcon(open->tlink)->open_file_lock);
661}
662
663/*
664 * Critical section which runs after acquiring deferred_lock.
665 * As there is no reference count on cifs_deferred_close, pdclose
666 * should not be used outside deferred_lock.
667 */
668bool
669cifs_is_deferred_close(struct cifsFileInfo *cfile, struct cifs_deferred_close **pdclose)
670{
671 struct cifs_deferred_close *dclose;
672
673 list_for_each_entry(dclose, &CIFS_I(d_inode(cfile->dentry))->deferred_closes, dlist) {
674 if ((dclose->netfid == cfile->fid.netfid) &&
675 (dclose->persistent_fid == cfile->fid.persistent_fid) &&
676 (dclose->volatile_fid == cfile->fid.volatile_fid)) {
677 *pdclose = dclose;
678 return true;
679 }
680 }
681 return false;
682}
683
684/*
685 * Critical section which runs after acquiring deferred_lock.
686 */
687void
688cifs_add_deferred_close(struct cifsFileInfo *cfile, struct cifs_deferred_close *dclose)
689{
690 bool is_deferred = false;
691 struct cifs_deferred_close *pdclose;
692
693 is_deferred = cifs_is_deferred_close(cfile, &pdclose);
694 if (is_deferred) {
695 kfree(dclose);
696 return;
697 }
698
699 dclose->tlink = cfile->tlink;
700 dclose->netfid = cfile->fid.netfid;
701 dclose->persistent_fid = cfile->fid.persistent_fid;
702 dclose->volatile_fid = cfile->fid.volatile_fid;
703 list_add_tail(&dclose->dlist, &CIFS_I(d_inode(cfile->dentry))->deferred_closes);
704}
705
706/*
707 * Critical section which runs after acquiring deferred_lock.
708 */
709void
710cifs_del_deferred_close(struct cifsFileInfo *cfile)
711{
712 bool is_deferred = false;
713 struct cifs_deferred_close *dclose;
714
715 is_deferred = cifs_is_deferred_close(cfile, &dclose);
716 if (!is_deferred)
717 return;
718 list_del(&dclose->dlist);
719 kfree(dclose);
720}
721
722void
723cifs_close_deferred_file(struct cifsInodeInfo *cifs_inode)
724{
725 struct cifsFileInfo *cfile = NULL;
726 struct file_list *tmp_list, *tmp_next_list;
727 struct list_head file_head;
728
729 if (cifs_inode == NULL)
730 return;
731
732 INIT_LIST_HEAD(&file_head);
733 spin_lock(&cifs_inode->open_file_lock);
734 list_for_each_entry(cfile, &cifs_inode->openFileList, flist) {
735 if (delayed_work_pending(&cfile->deferred)) {
736 if (cancel_delayed_work(&cfile->deferred)) {
737 tmp_list = kmalloc(sizeof(struct file_list), GFP_ATOMIC);
738 if (tmp_list == NULL)
739 break;
740 tmp_list->cfile = cfile;
741 list_add_tail(&tmp_list->list, &file_head);
742 }
743 }
744 }
745 spin_unlock(&cifs_inode->open_file_lock);
746
747 list_for_each_entry_safe(tmp_list, tmp_next_list, &file_head, list) {
748 _cifsFileInfo_put(tmp_list->cfile, true, false);
749 list_del(&tmp_list->list);
750 kfree(tmp_list);
751 }
752}
753
754void
755cifs_close_all_deferred_files(struct cifs_tcon *tcon)
756{
757 struct cifsFileInfo *cfile;
758 struct list_head *tmp;
759 struct file_list *tmp_list, *tmp_next_list;
760 struct list_head file_head;
761
762 INIT_LIST_HEAD(&file_head);
763 spin_lock(&tcon->open_file_lock);
764 list_for_each(tmp, &tcon->openFileList) {
765 cfile = list_entry(tmp, struct cifsFileInfo, tlist);
766 if (delayed_work_pending(&cfile->deferred)) {
767 if (cancel_delayed_work(&cfile->deferred)) {
768 tmp_list = kmalloc(sizeof(struct file_list), GFP_ATOMIC);
769 if (tmp_list == NULL)
770 break;
771 tmp_list->cfile = cfile;
772 list_add_tail(&tmp_list->list, &file_head);
773 }
774 }
775 }
776 spin_unlock(&tcon->open_file_lock);
777
778 list_for_each_entry_safe(tmp_list, tmp_next_list, &file_head, list) {
779 _cifsFileInfo_put(tmp_list->cfile, true, false);
780 list_del(&tmp_list->list);
781 kfree(tmp_list);
782 }
783}
784
785/* parses DFS refferal V3 structure
786 * caller is responsible for freeing target_nodes
787 * returns:
788 * - on success - 0
789 * - on failure - errno
790 */
791int
792parse_dfs_referrals(struct get_dfs_referral_rsp *rsp, u32 rsp_size,
793 unsigned int *num_of_nodes,
794 struct dfs_info3_param **target_nodes,
795 const struct nls_table *nls_codepage, int remap,
796 const char *searchName, bool is_unicode)
797{
798 int i, rc = 0;
799 char *data_end;
800 struct dfs_referral_level_3 *ref;
801
802 *num_of_nodes = le16_to_cpu(rsp->NumberOfReferrals);
803
804 if (*num_of_nodes < 1) {
805 cifs_dbg(VFS, "num_referrals: must be at least > 0, but we get num_referrals = %d\n",
806 *num_of_nodes);
807 rc = -EINVAL;
808 goto parse_DFS_referrals_exit;
809 }
810
811 ref = (struct dfs_referral_level_3 *) &(rsp->referrals);
812 if (ref->VersionNumber != cpu_to_le16(3)) {
813 cifs_dbg(VFS, "Referrals of V%d version are not supported, should be V3\n",
814 le16_to_cpu(ref->VersionNumber));
815 rc = -EINVAL;
816 goto parse_DFS_referrals_exit;
817 }
818
819 /* get the upper boundary of the resp buffer */
820 data_end = (char *)rsp + rsp_size;
821
822 cifs_dbg(FYI, "num_referrals: %d dfs flags: 0x%x ...\n",
823 *num_of_nodes, le32_to_cpu(rsp->DFSFlags));
824
825 *target_nodes = kcalloc(*num_of_nodes, sizeof(struct dfs_info3_param),
826 GFP_KERNEL);
827 if (*target_nodes == NULL) {
828 rc = -ENOMEM;
829 goto parse_DFS_referrals_exit;
830 }
831
832 /* collect necessary data from referrals */
833 for (i = 0; i < *num_of_nodes; i++) {
834 char *temp;
835 int max_len;
836 struct dfs_info3_param *node = (*target_nodes)+i;
837
838 node->flags = le32_to_cpu(rsp->DFSFlags);
839 if (is_unicode) {
840 __le16 *tmp = kmalloc(strlen(searchName)*2 + 2,
841 GFP_KERNEL);
842 if (tmp == NULL) {
843 rc = -ENOMEM;
844 goto parse_DFS_referrals_exit;
845 }
846 cifsConvertToUTF16((__le16 *) tmp, searchName,
847 PATH_MAX, nls_codepage, remap);
848 node->path_consumed = cifs_utf16_bytes(tmp,
849 le16_to_cpu(rsp->PathConsumed),
850 nls_codepage);
851 kfree(tmp);
852 } else
853 node->path_consumed = le16_to_cpu(rsp->PathConsumed);
854
855 node->server_type = le16_to_cpu(ref->ServerType);
856 node->ref_flag = le16_to_cpu(ref->ReferralEntryFlags);
857
858 /* copy DfsPath */
859 temp = (char *)ref + le16_to_cpu(ref->DfsPathOffset);
860 max_len = data_end - temp;
861 node->path_name = cifs_strndup_from_utf16(temp, max_len,
862 is_unicode, nls_codepage);
863 if (!node->path_name) {
864 rc = -ENOMEM;
865 goto parse_DFS_referrals_exit;
866 }
867
868 /* copy link target UNC */
869 temp = (char *)ref + le16_to_cpu(ref->NetworkAddressOffset);
870 max_len = data_end - temp;
871 node->node_name = cifs_strndup_from_utf16(temp, max_len,
872 is_unicode, nls_codepage);
873 if (!node->node_name) {
874 rc = -ENOMEM;
875 goto parse_DFS_referrals_exit;
876 }
877
878 node->ttl = le32_to_cpu(ref->TimeToLive);
879
880 ref++;
881 }
882
883parse_DFS_referrals_exit:
884 if (rc) {
885 free_dfs_info_array(*target_nodes, *num_of_nodes);
886 *target_nodes = NULL;
887 *num_of_nodes = 0;
888 }
889 return rc;
890}
891
892struct cifs_aio_ctx *
893cifs_aio_ctx_alloc(void)
894{
895 struct cifs_aio_ctx *ctx;
896
897 /*
898 * Must use kzalloc to initialize ctx->bv to NULL and ctx->direct_io
899 * to false so that we know when we have to unreference pages within
900 * cifs_aio_ctx_release()
901 */
902 ctx = kzalloc(sizeof(struct cifs_aio_ctx), GFP_KERNEL);
903 if (!ctx)
904 return NULL;
905
906 INIT_LIST_HEAD(&ctx->list);
907 mutex_init(&ctx->aio_mutex);
908 init_completion(&ctx->done);
909 kref_init(&ctx->refcount);
910 return ctx;
911}
912
913void
914cifs_aio_ctx_release(struct kref *refcount)
915{
916 struct cifs_aio_ctx *ctx = container_of(refcount,
917 struct cifs_aio_ctx, refcount);
918
919 cifsFileInfo_put(ctx->cfile);
920
921 /*
922 * ctx->bv is only set if setup_aio_ctx_iter() was call successfuly
923 * which means that iov_iter_get_pages() was a success and thus that
924 * we have taken reference on pages.
925 */
926 if (ctx->bv) {
927 unsigned i;
928
929 for (i = 0; i < ctx->npages; i++) {
930 if (ctx->should_dirty)
931 set_page_dirty(ctx->bv[i].bv_page);
932 put_page(ctx->bv[i].bv_page);
933 }
934 kvfree(ctx->bv);
935 }
936
937 kfree(ctx);
938}
939
940#define CIFS_AIO_KMALLOC_LIMIT (1024 * 1024)
941
942int
943setup_aio_ctx_iter(struct cifs_aio_ctx *ctx, struct iov_iter *iter, int rw)
944{
945 ssize_t rc;
946 unsigned int cur_npages;
947 unsigned int npages = 0;
948 unsigned int i;
949 size_t len;
950 size_t count = iov_iter_count(iter);
951 unsigned int saved_len;
952 size_t start;
953 unsigned int max_pages = iov_iter_npages(iter, INT_MAX);
954 struct page **pages = NULL;
955 struct bio_vec *bv = NULL;
956
957 if (iov_iter_is_kvec(iter)) {
958 memcpy(&ctx->iter, iter, sizeof(*iter));
959 ctx->len = count;
960 iov_iter_advance(iter, count);
961 return 0;
962 }
963
964 if (array_size(max_pages, sizeof(*bv)) <= CIFS_AIO_KMALLOC_LIMIT)
965 bv = kmalloc_array(max_pages, sizeof(*bv), GFP_KERNEL);
966
967 if (!bv) {
968 bv = vmalloc(array_size(max_pages, sizeof(*bv)));
969 if (!bv)
970 return -ENOMEM;
971 }
972
973 if (array_size(max_pages, sizeof(*pages)) <= CIFS_AIO_KMALLOC_LIMIT)
974 pages = kmalloc_array(max_pages, sizeof(*pages), GFP_KERNEL);
975
976 if (!pages) {
977 pages = vmalloc(array_size(max_pages, sizeof(*pages)));
978 if (!pages) {
979 kvfree(bv);
980 return -ENOMEM;
981 }
982 }
983
984 saved_len = count;
985
986 while (count && npages < max_pages) {
987 rc = iov_iter_get_pages(iter, pages, count, max_pages, &start);
988 if (rc < 0) {
989 cifs_dbg(VFS, "Couldn't get user pages (rc=%zd)\n", rc);
990 break;
991 }
992
993 if (rc > count) {
994 cifs_dbg(VFS, "get pages rc=%zd more than %zu\n", rc,
995 count);
996 break;
997 }
998
999 iov_iter_advance(iter, rc);
1000 count -= rc;
1001 rc += start;
1002 cur_npages = DIV_ROUND_UP(rc, PAGE_SIZE);
1003
1004 if (npages + cur_npages > max_pages) {
1005 cifs_dbg(VFS, "out of vec array capacity (%u vs %u)\n",
1006 npages + cur_npages, max_pages);
1007 break;
1008 }
1009
1010 for (i = 0; i < cur_npages; i++) {
1011 len = rc > PAGE_SIZE ? PAGE_SIZE : rc;
1012 bv[npages + i].bv_page = pages[i];
1013 bv[npages + i].bv_offset = start;
1014 bv[npages + i].bv_len = len - start;
1015 rc -= len;
1016 start = 0;
1017 }
1018
1019 npages += cur_npages;
1020 }
1021
1022 kvfree(pages);
1023 ctx->bv = bv;
1024 ctx->len = saved_len - count;
1025 ctx->npages = npages;
1026 iov_iter_bvec(&ctx->iter, rw, ctx->bv, npages, ctx->len);
1027 return 0;
1028}
1029
1030/**
1031 * cifs_alloc_hash - allocate hash and hash context together
1032 *
1033 * The caller has to make sure @sdesc is initialized to either NULL or
1034 * a valid context. Both can be freed via cifs_free_hash().
1035 */
1036int
1037cifs_alloc_hash(const char *name,
1038 struct crypto_shash **shash, struct sdesc **sdesc)
1039{
1040 int rc = 0;
1041 size_t size;
1042
1043 if (*sdesc != NULL)
1044 return 0;
1045
1046 *shash = crypto_alloc_shash(name, 0, 0);
1047 if (IS_ERR(*shash)) {
1048 cifs_dbg(VFS, "Could not allocate crypto %s\n", name);
1049 rc = PTR_ERR(*shash);
1050 *shash = NULL;
1051 *sdesc = NULL;
1052 return rc;
1053 }
1054
1055 size = sizeof(struct shash_desc) + crypto_shash_descsize(*shash);
1056 *sdesc = kmalloc(size, GFP_KERNEL);
1057 if (*sdesc == NULL) {
1058 cifs_dbg(VFS, "no memory left to allocate crypto %s\n", name);
1059 crypto_free_shash(*shash);
1060 *shash = NULL;
1061 return -ENOMEM;
1062 }
1063
1064 (*sdesc)->shash.tfm = *shash;
1065 return 0;
1066}
1067
1068/**
1069 * cifs_free_hash - free hash and hash context together
1070 *
1071 * Freeing a NULL hash or context is safe.
1072 */
1073void
1074cifs_free_hash(struct crypto_shash **shash, struct sdesc **sdesc)
1075{
1076 kfree(*sdesc);
1077 *sdesc = NULL;
1078 if (*shash)
1079 crypto_free_shash(*shash);
1080 *shash = NULL;
1081}
1082
1083/**
1084 * rqst_page_get_length - obtain the length and offset for a page in smb_rqst
1085 * Input: rqst - a smb_rqst, page - a page index for rqst
1086 * Output: *len - the length for this page, *offset - the offset for this page
1087 */
1088void rqst_page_get_length(struct smb_rqst *rqst, unsigned int page,
1089 unsigned int *len, unsigned int *offset)
1090{
1091 *len = rqst->rq_pagesz;
1092 *offset = (page == 0) ? rqst->rq_offset : 0;
1093
1094 if (rqst->rq_npages == 1 || page == rqst->rq_npages-1)
1095 *len = rqst->rq_tailsz;
1096 else if (page == 0)
1097 *len = rqst->rq_pagesz - rqst->rq_offset;
1098}
1099
1100void extract_unc_hostname(const char *unc, const char **h, size_t *len)
1101{
1102 const char *end;
1103
1104 /* skip initial slashes */
1105 while (*unc && (*unc == '\\' || *unc == '/'))
1106 unc++;
1107
1108 end = unc;
1109
1110 while (*end && !(*end == '\\' || *end == '/'))
1111 end++;
1112
1113 *h = unc;
1114 *len = end - unc;
1115}
1116
1117/**
1118 * copy_path_name - copy src path to dst, possibly truncating
1119 *
1120 * returns number of bytes written (including trailing nul)
1121 */
1122int copy_path_name(char *dst, const char *src)
1123{
1124 int name_len;
1125
1126 /*
1127 * PATH_MAX includes nul, so if strlen(src) >= PATH_MAX it
1128 * will truncate and strlen(dst) will be PATH_MAX-1
1129 */
1130 name_len = strscpy(dst, src, PATH_MAX);
1131 if (WARN_ON_ONCE(name_len < 0))
1132 name_len = PATH_MAX-1;
1133
1134 /* we count the trailing nul */
1135 name_len++;
1136 return name_len;
1137}
1138
1139struct super_cb_data {
1140 void *data;
1141 struct super_block *sb;
1142};
1143
1144static void tcp_super_cb(struct super_block *sb, void *arg)
1145{
1146 struct super_cb_data *sd = arg;
1147 struct TCP_Server_Info *server = sd->data;
1148 struct cifs_sb_info *cifs_sb;
1149 struct cifs_tcon *tcon;
1150
1151 if (sd->sb)
1152 return;
1153
1154 cifs_sb = CIFS_SB(sb);
1155 tcon = cifs_sb_master_tcon(cifs_sb);
1156 if (tcon->ses->server == server)
1157 sd->sb = sb;
1158}
1159
1160static struct super_block *__cifs_get_super(void (*f)(struct super_block *, void *),
1161 void *data)
1162{
1163 struct super_cb_data sd = {
1164 .data = data,
1165 .sb = NULL,
1166 };
1167
1168 iterate_supers_type(&cifs_fs_type, f, &sd);
1169
1170 if (!sd.sb)
1171 return ERR_PTR(-EINVAL);
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
1181static void __cifs_put_super(struct super_block *sb)
1182{
1183 if (!IS_ERR_OR_NULL(sb))
1184 cifs_sb_deactive(sb);
1185}
1186
1187struct super_block *cifs_get_tcp_super(struct TCP_Server_Info *server)
1188{
1189 return __cifs_get_super(tcp_super_cb, server);
1190}
1191
1192void cifs_put_tcp_super(struct super_block *sb)
1193{
1194 __cifs_put_super(sb);
1195}
1196
1197#ifdef CONFIG_CIFS_DFS_UPCALL
1198int match_target_ip(struct TCP_Server_Info *server,
1199 const char *share, size_t share_len,
1200 bool *result)
1201{
1202 int rc;
1203 char *target, *tip = NULL;
1204 struct sockaddr tipaddr;
1205
1206 *result = false;
1207
1208 target = kzalloc(share_len + 3, GFP_KERNEL);
1209 if (!target) {
1210 rc = -ENOMEM;
1211 goto out;
1212 }
1213
1214 scnprintf(target, share_len + 3, "\\\\%.*s", (int)share_len, share);
1215
1216 cifs_dbg(FYI, "%s: target name: %s\n", __func__, target + 2);
1217
1218 rc = dns_resolve_server_name_to_ip(target, &tip, NULL);
1219 if (rc < 0)
1220 goto out;
1221
1222 cifs_dbg(FYI, "%s: target ip: %s\n", __func__, tip);
1223
1224 if (!cifs_convert_address(&tipaddr, tip, strlen(tip))) {
1225 cifs_dbg(VFS, "%s: failed to convert target ip address\n",
1226 __func__);
1227 rc = -EINVAL;
1228 goto out;
1229 }
1230
1231 *result = cifs_match_ipaddr((struct sockaddr *)&server->dstaddr,
1232 &tipaddr);
1233 cifs_dbg(FYI, "%s: ip addresses match: %u\n", __func__, *result);
1234 rc = 0;
1235
1236out:
1237 kfree(target);
1238 kfree(tip);
1239
1240 return rc;
1241}
1242
1243static void tcon_super_cb(struct super_block *sb, void *arg)
1244{
1245 struct super_cb_data *sd = arg;
1246 struct cifs_tcon *tcon = sd->data;
1247 struct cifs_sb_info *cifs_sb;
1248
1249 if (sd->sb)
1250 return;
1251
1252 cifs_sb = CIFS_SB(sb);
1253 if (tcon->dfs_path && cifs_sb->origin_fullpath &&
1254 !strcasecmp(tcon->dfs_path, cifs_sb->origin_fullpath))
1255 sd->sb = sb;
1256}
1257
1258static inline struct super_block *cifs_get_tcon_super(struct cifs_tcon *tcon)
1259{
1260 return __cifs_get_super(tcon_super_cb, tcon);
1261}
1262
1263static inline void cifs_put_tcon_super(struct super_block *sb)
1264{
1265 __cifs_put_super(sb);
1266}
1267#else
1268static inline struct super_block *cifs_get_tcon_super(struct cifs_tcon *tcon)
1269{
1270 return ERR_PTR(-EOPNOTSUPP);
1271}
1272
1273static inline void cifs_put_tcon_super(struct super_block *sb)
1274{
1275}
1276#endif
1277
1278int update_super_prepath(struct cifs_tcon *tcon, char *prefix)
1279{
1280 struct super_block *sb;
1281 struct cifs_sb_info *cifs_sb;
1282 int rc = 0;
1283
1284 sb = cifs_get_tcon_super(tcon);
1285 if (IS_ERR(sb))
1286 return PTR_ERR(sb);
1287
1288 cifs_sb = CIFS_SB(sb);
1289
1290 kfree(cifs_sb->prepath);
1291
1292 if (prefix && *prefix) {
1293 cifs_sb->prepath = kstrdup(prefix, GFP_ATOMIC);
1294 if (!cifs_sb->prepath) {
1295 rc = -ENOMEM;
1296 goto out;
1297 }
1298
1299 convert_delimiter(cifs_sb->prepath, CIFS_DIR_SEP(cifs_sb));
1300 } else
1301 cifs_sb->prepath = NULL;
1302
1303 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
1304
1305out:
1306 cifs_put_tcon_super(sb);
1307 return rc;
1308}