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
35 extern mempool_t *cifs_sm_req_poolp;
36 extern 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
44 unsigned int
_get_xid(void)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
62 void
_free_xid(unsigned int xid)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
72 struct cifs_ses *
sesInfoAlloc(void)73 sesInfoAlloc(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 spin_lock_init(&ret_buf->iface_lock);
86 }
87 return ret_buf;
88 }
89
90 void
sesInfoFree(struct cifs_ses * buf_to_free)91 sesInfoFree(struct cifs_ses *buf_to_free)
92 {
93 if (buf_to_free == NULL) {
94 cifs_dbg(FYI, "Null buffer passed to sesInfoFree\n");
95 return;
96 }
97
98 atomic_dec(&sesInfoAllocCount);
99 kfree(buf_to_free->serverOS);
100 kfree(buf_to_free->serverDomain);
101 kfree(buf_to_free->serverNOS);
102 kzfree(buf_to_free->password);
103 kfree(buf_to_free->user_name);
104 kfree(buf_to_free->domainName);
105 kzfree(buf_to_free->auth_key.response);
106 kfree(buf_to_free->iface_list);
107 kzfree(buf_to_free);
108 }
109
110 struct cifs_tcon *
tconInfoAlloc(void)111 tconInfoAlloc(void)
112 {
113 struct cifs_tcon *ret_buf;
114 ret_buf = kzalloc(sizeof(struct cifs_tcon), GFP_KERNEL);
115 if (ret_buf) {
116 atomic_inc(&tconInfoAllocCount);
117 ret_buf->tidStatus = CifsNew;
118 ++ret_buf->tc_count;
119 INIT_LIST_HEAD(&ret_buf->openFileList);
120 INIT_LIST_HEAD(&ret_buf->tcon_list);
121 spin_lock_init(&ret_buf->open_file_lock);
122 mutex_init(&ret_buf->crfid.fid_mutex);
123 ret_buf->crfid.fid = kzalloc(sizeof(struct cifs_fid),
124 GFP_KERNEL);
125 spin_lock_init(&ret_buf->stat_lock);
126 }
127 return ret_buf;
128 }
129
130 void
tconInfoFree(struct cifs_tcon * buf_to_free)131 tconInfoFree(struct cifs_tcon *buf_to_free)
132 {
133 if (buf_to_free == NULL) {
134 cifs_dbg(FYI, "Null buffer passed to tconInfoFree\n");
135 return;
136 }
137 atomic_dec(&tconInfoAllocCount);
138 kfree(buf_to_free->nativeFileSystem);
139 kzfree(buf_to_free->password);
140 kfree(buf_to_free->crfid.fid);
141 kfree(buf_to_free);
142 }
143
144 struct smb_hdr *
cifs_buf_get(void)145 cifs_buf_get(void)
146 {
147 struct smb_hdr *ret_buf = NULL;
148 /*
149 * SMB2 header is bigger than CIFS one - no problems to clean some
150 * more bytes for CIFS.
151 */
152 size_t buf_size = sizeof(struct smb2_sync_hdr);
153
154 /*
155 * We could use negotiated size instead of max_msgsize -
156 * but it may be more efficient to always alloc same size
157 * albeit slightly larger than necessary and maxbuffersize
158 * defaults to this and can not be bigger.
159 */
160 ret_buf = mempool_alloc(cifs_req_poolp, GFP_NOFS);
161
162 /* clear the first few header bytes */
163 /* for most paths, more is cleared in header_assemble */
164 memset(ret_buf, 0, buf_size + 3);
165 atomic_inc(&bufAllocCount);
166 #ifdef CONFIG_CIFS_STATS2
167 atomic_inc(&totBufAllocCount);
168 #endif /* CONFIG_CIFS_STATS2 */
169
170 return ret_buf;
171 }
172
173 void
cifs_buf_release(void * buf_to_free)174 cifs_buf_release(void *buf_to_free)
175 {
176 if (buf_to_free == NULL) {
177 /* cifs_dbg(FYI, "Null buffer passed to cifs_buf_release\n");*/
178 return;
179 }
180 mempool_free(buf_to_free, cifs_req_poolp);
181
182 atomic_dec(&bufAllocCount);
183 return;
184 }
185
186 struct smb_hdr *
cifs_small_buf_get(void)187 cifs_small_buf_get(void)
188 {
189 struct smb_hdr *ret_buf = NULL;
190
191 /* We could use negotiated size instead of max_msgsize -
192 but it may be more efficient to always alloc same size
193 albeit slightly larger than necessary and maxbuffersize
194 defaults to this and can not be bigger */
195 ret_buf = mempool_alloc(cifs_sm_req_poolp, GFP_NOFS);
196 /* No need to clear memory here, cleared in header assemble */
197 /* memset(ret_buf, 0, sizeof(struct smb_hdr) + 27);*/
198 atomic_inc(&smBufAllocCount);
199 #ifdef CONFIG_CIFS_STATS2
200 atomic_inc(&totSmBufAllocCount);
201 #endif /* CONFIG_CIFS_STATS2 */
202
203 return ret_buf;
204 }
205
206 void
cifs_small_buf_release(void * buf_to_free)207 cifs_small_buf_release(void *buf_to_free)
208 {
209
210 if (buf_to_free == NULL) {
211 cifs_dbg(FYI, "Null buffer passed to cifs_small_buf_release\n");
212 return;
213 }
214 mempool_free(buf_to_free, cifs_sm_req_poolp);
215
216 atomic_dec(&smBufAllocCount);
217 return;
218 }
219
220 void
free_rsp_buf(int resp_buftype,void * rsp)221 free_rsp_buf(int resp_buftype, void *rsp)
222 {
223 if (resp_buftype == CIFS_SMALL_BUFFER)
224 cifs_small_buf_release(rsp);
225 else if (resp_buftype == CIFS_LARGE_BUFFER)
226 cifs_buf_release(rsp);
227 }
228
229 /* NB: MID can not be set if treeCon not passed in, in that
230 case it is responsbility of caller to set the mid */
231 void
header_assemble(struct smb_hdr * buffer,char smb_command,const struct cifs_tcon * treeCon,int word_count)232 header_assemble(struct smb_hdr *buffer, char smb_command /* command */ ,
233 const struct cifs_tcon *treeCon, int word_count
234 /* length of fixed section (word count) in two byte units */)
235 {
236 char *temp = (char *) buffer;
237
238 memset(temp, 0, 256); /* bigger than MAX_CIFS_HDR_SIZE */
239
240 buffer->smb_buf_length = cpu_to_be32(
241 (2 * word_count) + sizeof(struct smb_hdr) -
242 4 /* RFC 1001 length field does not count */ +
243 2 /* for bcc field itself */) ;
244
245 buffer->Protocol[0] = 0xFF;
246 buffer->Protocol[1] = 'S';
247 buffer->Protocol[2] = 'M';
248 buffer->Protocol[3] = 'B';
249 buffer->Command = smb_command;
250 buffer->Flags = 0x00; /* case sensitive */
251 buffer->Flags2 = SMBFLG2_KNOWS_LONG_NAMES;
252 buffer->Pid = cpu_to_le16((__u16)current->tgid);
253 buffer->PidHigh = cpu_to_le16((__u16)(current->tgid >> 16));
254 if (treeCon) {
255 buffer->Tid = treeCon->tid;
256 if (treeCon->ses) {
257 if (treeCon->ses->capabilities & CAP_UNICODE)
258 buffer->Flags2 |= SMBFLG2_UNICODE;
259 if (treeCon->ses->capabilities & CAP_STATUS32)
260 buffer->Flags2 |= SMBFLG2_ERR_STATUS;
261
262 /* Uid is not converted */
263 buffer->Uid = treeCon->ses->Suid;
264 buffer->Mid = get_next_mid(treeCon->ses->server);
265 }
266 if (treeCon->Flags & SMB_SHARE_IS_IN_DFS)
267 buffer->Flags2 |= SMBFLG2_DFS;
268 if (treeCon->nocase)
269 buffer->Flags |= SMBFLG_CASELESS;
270 if ((treeCon->ses) && (treeCon->ses->server))
271 if (treeCon->ses->server->sign)
272 buffer->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
273 }
274
275 /* endian conversion of flags is now done just before sending */
276 buffer->WordCount = (char) word_count;
277 return;
278 }
279
280 static int
check_smb_hdr(struct smb_hdr * smb)281 check_smb_hdr(struct smb_hdr *smb)
282 {
283 /* does it have the right SMB "signature" ? */
284 if (*(__le32 *) smb->Protocol != cpu_to_le32(0x424d53ff)) {
285 cifs_dbg(VFS, "Bad protocol string signature header 0x%x\n",
286 *(unsigned int *)smb->Protocol);
287 return 1;
288 }
289
290 /* if it's a response then accept */
291 if (smb->Flags & SMBFLG_RESPONSE)
292 return 0;
293
294 /* only one valid case where server sends us request */
295 if (smb->Command == SMB_COM_LOCKING_ANDX)
296 return 0;
297
298 cifs_dbg(VFS, "Server sent request, not response. mid=%u\n",
299 get_mid(smb));
300 return 1;
301 }
302
303 int
checkSMB(char * buf,unsigned int total_read,struct TCP_Server_Info * server)304 checkSMB(char *buf, unsigned int total_read, struct TCP_Server_Info *server)
305 {
306 struct smb_hdr *smb = (struct smb_hdr *)buf;
307 __u32 rfclen = be32_to_cpu(smb->smb_buf_length);
308 __u32 clc_len; /* calculated length */
309 cifs_dbg(FYI, "checkSMB Length: 0x%x, smb_buf_length: 0x%x\n",
310 total_read, rfclen);
311
312 /* is this frame too small to even get to a BCC? */
313 if (total_read < 2 + sizeof(struct smb_hdr)) {
314 if ((total_read >= sizeof(struct smb_hdr) - 1)
315 && (smb->Status.CifsError != 0)) {
316 /* it's an error return */
317 smb->WordCount = 0;
318 /* some error cases do not return wct and bcc */
319 return 0;
320 } else if ((total_read == sizeof(struct smb_hdr) + 1) &&
321 (smb->WordCount == 0)) {
322 char *tmp = (char *)smb;
323 /* Need to work around a bug in two servers here */
324 /* First, check if the part of bcc they sent was zero */
325 if (tmp[sizeof(struct smb_hdr)] == 0) {
326 /* some servers return only half of bcc
327 * on simple responses (wct, bcc both zero)
328 * in particular have seen this on
329 * ulogoffX and FindClose. This leaves
330 * one byte of bcc potentially unitialized
331 */
332 /* zero rest of bcc */
333 tmp[sizeof(struct smb_hdr)+1] = 0;
334 return 0;
335 }
336 cifs_dbg(VFS, "rcvd invalid byte count (bcc)\n");
337 } else {
338 cifs_dbg(VFS, "Length less than smb header size\n");
339 }
340 return -EIO;
341 }
342
343 /* otherwise, there is enough to get to the BCC */
344 if (check_smb_hdr(smb))
345 return -EIO;
346 clc_len = smbCalcSize(smb, server);
347
348 if (4 + rfclen != total_read) {
349 cifs_dbg(VFS, "Length read does not match RFC1001 length %d\n",
350 rfclen);
351 return -EIO;
352 }
353
354 if (4 + rfclen != clc_len) {
355 __u16 mid = get_mid(smb);
356 /* check if bcc wrapped around for large read responses */
357 if ((rfclen > 64 * 1024) && (rfclen > clc_len)) {
358 /* check if lengths match mod 64K */
359 if (((4 + rfclen) & 0xFFFF) == (clc_len & 0xFFFF))
360 return 0; /* bcc wrapped */
361 }
362 cifs_dbg(FYI, "Calculated size %u vs length %u mismatch for mid=%u\n",
363 clc_len, 4 + rfclen, mid);
364
365 if (4 + rfclen < clc_len) {
366 cifs_dbg(VFS, "RFC1001 size %u smaller than SMB for mid=%u\n",
367 rfclen, mid);
368 return -EIO;
369 } else if (rfclen > clc_len + 512) {
370 /*
371 * Some servers (Windows XP in particular) send more
372 * data than the lengths in the SMB packet would
373 * indicate on certain calls (byte range locks and
374 * trans2 find first calls in particular). While the
375 * client can handle such a frame by ignoring the
376 * trailing data, we choose limit the amount of extra
377 * data to 512 bytes.
378 */
379 cifs_dbg(VFS, "RFC1001 size %u more than 512 bytes larger than SMB for mid=%u\n",
380 rfclen, mid);
381 return -EIO;
382 }
383 }
384 return 0;
385 }
386
387 bool
is_valid_oplock_break(char * buffer,struct TCP_Server_Info * srv)388 is_valid_oplock_break(char *buffer, struct TCP_Server_Info *srv)
389 {
390 struct smb_hdr *buf = (struct smb_hdr *)buffer;
391 struct smb_com_lock_req *pSMB = (struct smb_com_lock_req *)buf;
392 struct list_head *tmp, *tmp1, *tmp2;
393 struct cifs_ses *ses;
394 struct cifs_tcon *tcon;
395 struct cifsInodeInfo *pCifsInode;
396 struct cifsFileInfo *netfile;
397
398 cifs_dbg(FYI, "Checking for oplock break or dnotify response\n");
399 if ((pSMB->hdr.Command == SMB_COM_NT_TRANSACT) &&
400 (pSMB->hdr.Flags & SMBFLG_RESPONSE)) {
401 struct smb_com_transaction_change_notify_rsp *pSMBr =
402 (struct smb_com_transaction_change_notify_rsp *)buf;
403 struct file_notify_information *pnotify;
404 __u32 data_offset = 0;
405 size_t len = srv->total_read - sizeof(pSMBr->hdr.smb_buf_length);
406
407 if (get_bcc(buf) > sizeof(struct file_notify_information)) {
408 data_offset = le32_to_cpu(pSMBr->DataOffset);
409
410 if (data_offset >
411 len - sizeof(struct file_notify_information)) {
412 cifs_dbg(FYI, "invalid data_offset %u\n",
413 data_offset);
414 return true;
415 }
416 pnotify = (struct file_notify_information *)
417 ((char *)&pSMBr->hdr.Protocol + data_offset);
418 cifs_dbg(FYI, "dnotify on %s Action: 0x%x\n",
419 pnotify->FileName, pnotify->Action);
420 /* cifs_dump_mem("Rcvd notify Data: ",buf,
421 sizeof(struct smb_hdr)+60); */
422 return true;
423 }
424 if (pSMBr->hdr.Status.CifsError) {
425 cifs_dbg(FYI, "notify err 0x%x\n",
426 pSMBr->hdr.Status.CifsError);
427 return true;
428 }
429 return false;
430 }
431 if (pSMB->hdr.Command != SMB_COM_LOCKING_ANDX)
432 return false;
433 if (pSMB->hdr.Flags & SMBFLG_RESPONSE) {
434 /* no sense logging error on invalid handle on oplock
435 break - harmless race between close request and oplock
436 break response is expected from time to time writing out
437 large dirty files cached on the client */
438 if ((NT_STATUS_INVALID_HANDLE) ==
439 le32_to_cpu(pSMB->hdr.Status.CifsError)) {
440 cifs_dbg(FYI, "invalid handle on oplock break\n");
441 return true;
442 } else if (ERRbadfid ==
443 le16_to_cpu(pSMB->hdr.Status.DosError.Error)) {
444 return true;
445 } else {
446 return false; /* on valid oplock brk we get "request" */
447 }
448 }
449 if (pSMB->hdr.WordCount != 8)
450 return false;
451
452 cifs_dbg(FYI, "oplock type 0x%x level 0x%x\n",
453 pSMB->LockType, pSMB->OplockLevel);
454 if (!(pSMB->LockType & LOCKING_ANDX_OPLOCK_RELEASE))
455 return false;
456
457 /* look up tcon based on tid & uid */
458 spin_lock(&cifs_tcp_ses_lock);
459 list_for_each(tmp, &srv->smb_ses_list) {
460 ses = list_entry(tmp, struct cifs_ses, smb_ses_list);
461 list_for_each(tmp1, &ses->tcon_list) {
462 tcon = list_entry(tmp1, struct cifs_tcon, tcon_list);
463 if (tcon->tid != buf->Tid)
464 continue;
465
466 cifs_stats_inc(&tcon->stats.cifs_stats.num_oplock_brks);
467 spin_lock(&tcon->open_file_lock);
468 list_for_each(tmp2, &tcon->openFileList) {
469 netfile = list_entry(tmp2, struct cifsFileInfo,
470 tlist);
471 if (pSMB->Fid != netfile->fid.netfid)
472 continue;
473
474 cifs_dbg(FYI, "file id match, oplock break\n");
475 pCifsInode = CIFS_I(d_inode(netfile->dentry));
476
477 set_bit(CIFS_INODE_PENDING_OPLOCK_BREAK,
478 &pCifsInode->flags);
479
480 netfile->oplock_epoch = 0;
481 netfile->oplock_level = pSMB->OplockLevel;
482 netfile->oplock_break_cancelled = false;
483 cifs_queue_oplock_break(netfile);
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
500 void
dump_smb(void * buf,int smb_buf_length)501 dump_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
510 void
cifs_autodisable_serverino(struct cifs_sb_info * cifs_sb)511 cifs_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_sb->mnt_cifs_serverino_autodisabled = true;
516 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",
517 cifs_sb_master_tcon(cifs_sb)->treeName);
518 }
519 }
520
cifs_set_oplock_level(struct cifsInodeInfo * cinode,__u32 oplock)521 void cifs_set_oplock_level(struct cifsInodeInfo *cinode, __u32 oplock)
522 {
523 oplock &= 0xF;
524
525 if (oplock == OPLOCK_EXCLUSIVE) {
526 cinode->oplock = CIFS_CACHE_WRITE_FLG | CIFS_CACHE_READ_FLG;
527 cifs_dbg(FYI, "Exclusive Oplock granted on inode %p\n",
528 &cinode->vfs_inode);
529 } else if (oplock == OPLOCK_READ) {
530 cinode->oplock = CIFS_CACHE_READ_FLG;
531 cifs_dbg(FYI, "Level II Oplock granted on inode %p\n",
532 &cinode->vfs_inode);
533 } else
534 cinode->oplock = 0;
535 }
536
537 /*
538 * We wait for oplock breaks to be processed before we attempt to perform
539 * writes.
540 */
cifs_get_writer(struct cifsInodeInfo * cinode)541 int cifs_get_writer(struct cifsInodeInfo *cinode)
542 {
543 int rc;
544
545 start:
546 rc = wait_on_bit(&cinode->flags, CIFS_INODE_PENDING_OPLOCK_BREAK,
547 TASK_KILLABLE);
548 if (rc)
549 return rc;
550
551 spin_lock(&cinode->writers_lock);
552 if (!cinode->writers)
553 set_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags);
554 cinode->writers++;
555 /* Check to see if we have started servicing an oplock break */
556 if (test_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, &cinode->flags)) {
557 cinode->writers--;
558 if (cinode->writers == 0) {
559 clear_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags);
560 wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_WRITERS);
561 }
562 spin_unlock(&cinode->writers_lock);
563 goto start;
564 }
565 spin_unlock(&cinode->writers_lock);
566 return 0;
567 }
568
cifs_put_writer(struct cifsInodeInfo * cinode)569 void cifs_put_writer(struct cifsInodeInfo *cinode)
570 {
571 spin_lock(&cinode->writers_lock);
572 cinode->writers--;
573 if (cinode->writers == 0) {
574 clear_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags);
575 wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_WRITERS);
576 }
577 spin_unlock(&cinode->writers_lock);
578 }
579
580 /**
581 * cifs_queue_oplock_break - queue the oplock break handler for cfile
582 *
583 * This function is called from the demultiplex thread when it
584 * receives an oplock break for @cfile.
585 *
586 * Assumes the tcon->open_file_lock is held.
587 * Assumes cfile->file_info_lock is NOT held.
588 */
cifs_queue_oplock_break(struct cifsFileInfo * cfile)589 void cifs_queue_oplock_break(struct cifsFileInfo *cfile)
590 {
591 /*
592 * Bump the handle refcount now while we hold the
593 * open_file_lock to enforce the validity of it for the oplock
594 * break handler. The matching put is done at the end of the
595 * handler.
596 */
597 cifsFileInfo_get(cfile);
598
599 queue_work(cifsoplockd_wq, &cfile->oplock_break);
600 }
601
cifs_done_oplock_break(struct cifsInodeInfo * cinode)602 void cifs_done_oplock_break(struct cifsInodeInfo *cinode)
603 {
604 clear_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, &cinode->flags);
605 wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_OPLOCK_BREAK);
606 }
607
608 bool
backup_cred(struct cifs_sb_info * cifs_sb)609 backup_cred(struct cifs_sb_info *cifs_sb)
610 {
611 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPUID) {
612 if (uid_eq(cifs_sb->mnt_backupuid, current_fsuid()))
613 return true;
614 }
615 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPGID) {
616 if (in_group_p(cifs_sb->mnt_backupgid))
617 return true;
618 }
619
620 return false;
621 }
622
623 void
cifs_del_pending_open(struct cifs_pending_open * open)624 cifs_del_pending_open(struct cifs_pending_open *open)
625 {
626 spin_lock(&tlink_tcon(open->tlink)->open_file_lock);
627 list_del(&open->olist);
628 spin_unlock(&tlink_tcon(open->tlink)->open_file_lock);
629 }
630
631 void
cifs_add_pending_open_locked(struct cifs_fid * fid,struct tcon_link * tlink,struct cifs_pending_open * open)632 cifs_add_pending_open_locked(struct cifs_fid *fid, struct tcon_link *tlink,
633 struct cifs_pending_open *open)
634 {
635 memcpy(open->lease_key, fid->lease_key, SMB2_LEASE_KEY_SIZE);
636 open->oplock = CIFS_OPLOCK_NO_CHANGE;
637 open->tlink = tlink;
638 fid->pending_open = open;
639 list_add_tail(&open->olist, &tlink_tcon(tlink)->pending_opens);
640 }
641
642 void
cifs_add_pending_open(struct cifs_fid * fid,struct tcon_link * tlink,struct cifs_pending_open * open)643 cifs_add_pending_open(struct cifs_fid *fid, struct tcon_link *tlink,
644 struct cifs_pending_open *open)
645 {
646 spin_lock(&tlink_tcon(tlink)->open_file_lock);
647 cifs_add_pending_open_locked(fid, tlink, open);
648 spin_unlock(&tlink_tcon(open->tlink)->open_file_lock);
649 }
650
651 /* parses DFS refferal V3 structure
652 * caller is responsible for freeing target_nodes
653 * returns:
654 * - on success - 0
655 * - on failure - errno
656 */
657 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)658 parse_dfs_referrals(struct get_dfs_referral_rsp *rsp, u32 rsp_size,
659 unsigned int *num_of_nodes,
660 struct dfs_info3_param **target_nodes,
661 const struct nls_table *nls_codepage, int remap,
662 const char *searchName, bool is_unicode)
663 {
664 int i, rc = 0;
665 char *data_end;
666 struct dfs_referral_level_3 *ref;
667
668 *num_of_nodes = le16_to_cpu(rsp->NumberOfReferrals);
669
670 if (*num_of_nodes < 1) {
671 cifs_dbg(VFS, "num_referrals: must be at least > 0, but we get num_referrals = %d\n",
672 *num_of_nodes);
673 rc = -EINVAL;
674 goto parse_DFS_referrals_exit;
675 }
676
677 ref = (struct dfs_referral_level_3 *) &(rsp->referrals);
678 if (ref->VersionNumber != cpu_to_le16(3)) {
679 cifs_dbg(VFS, "Referrals of V%d version are not supported, should be V3\n",
680 le16_to_cpu(ref->VersionNumber));
681 rc = -EINVAL;
682 goto parse_DFS_referrals_exit;
683 }
684
685 /* get the upper boundary of the resp buffer */
686 data_end = (char *)rsp + rsp_size;
687
688 cifs_dbg(FYI, "num_referrals: %d dfs flags: 0x%x ...\n",
689 *num_of_nodes, le32_to_cpu(rsp->DFSFlags));
690
691 *target_nodes = kcalloc(*num_of_nodes, sizeof(struct dfs_info3_param),
692 GFP_KERNEL);
693 if (*target_nodes == NULL) {
694 rc = -ENOMEM;
695 goto parse_DFS_referrals_exit;
696 }
697
698 /* collect necessary data from referrals */
699 for (i = 0; i < *num_of_nodes; i++) {
700 char *temp;
701 int max_len;
702 struct dfs_info3_param *node = (*target_nodes)+i;
703
704 node->flags = le32_to_cpu(rsp->DFSFlags);
705 if (is_unicode) {
706 __le16 *tmp = kmalloc(strlen(searchName)*2 + 2,
707 GFP_KERNEL);
708 if (tmp == NULL) {
709 rc = -ENOMEM;
710 goto parse_DFS_referrals_exit;
711 }
712 cifsConvertToUTF16((__le16 *) tmp, searchName,
713 PATH_MAX, nls_codepage, remap);
714 node->path_consumed = cifs_utf16_bytes(tmp,
715 le16_to_cpu(rsp->PathConsumed),
716 nls_codepage);
717 kfree(tmp);
718 } else
719 node->path_consumed = le16_to_cpu(rsp->PathConsumed);
720
721 node->server_type = le16_to_cpu(ref->ServerType);
722 node->ref_flag = le16_to_cpu(ref->ReferralEntryFlags);
723
724 /* copy DfsPath */
725 temp = (char *)ref + le16_to_cpu(ref->DfsPathOffset);
726 max_len = data_end - temp;
727 node->path_name = cifs_strndup_from_utf16(temp, max_len,
728 is_unicode, nls_codepage);
729 if (!node->path_name) {
730 rc = -ENOMEM;
731 goto parse_DFS_referrals_exit;
732 }
733
734 /* copy link target UNC */
735 temp = (char *)ref + le16_to_cpu(ref->NetworkAddressOffset);
736 max_len = data_end - temp;
737 node->node_name = cifs_strndup_from_utf16(temp, max_len,
738 is_unicode, nls_codepage);
739 if (!node->node_name) {
740 rc = -ENOMEM;
741 goto parse_DFS_referrals_exit;
742 }
743
744 ref++;
745 }
746
747 parse_DFS_referrals_exit:
748 if (rc) {
749 free_dfs_info_array(*target_nodes, *num_of_nodes);
750 *target_nodes = NULL;
751 *num_of_nodes = 0;
752 }
753 return rc;
754 }
755
756 struct cifs_aio_ctx *
cifs_aio_ctx_alloc(void)757 cifs_aio_ctx_alloc(void)
758 {
759 struct cifs_aio_ctx *ctx;
760
761 ctx = kzalloc(sizeof(struct cifs_aio_ctx), GFP_KERNEL);
762 if (!ctx)
763 return NULL;
764
765 INIT_LIST_HEAD(&ctx->list);
766 mutex_init(&ctx->aio_mutex);
767 init_completion(&ctx->done);
768 kref_init(&ctx->refcount);
769 return ctx;
770 }
771
772 void
cifs_aio_ctx_release(struct kref * refcount)773 cifs_aio_ctx_release(struct kref *refcount)
774 {
775 struct cifs_aio_ctx *ctx = container_of(refcount,
776 struct cifs_aio_ctx, refcount);
777
778 cifsFileInfo_put(ctx->cfile);
779 kvfree(ctx->bv);
780 kfree(ctx);
781 }
782
783 #define CIFS_AIO_KMALLOC_LIMIT (1024 * 1024)
784
785 int
setup_aio_ctx_iter(struct cifs_aio_ctx * ctx,struct iov_iter * iter,int rw)786 setup_aio_ctx_iter(struct cifs_aio_ctx *ctx, struct iov_iter *iter, int rw)
787 {
788 ssize_t rc;
789 unsigned int cur_npages;
790 unsigned int npages = 0;
791 unsigned int i;
792 size_t len;
793 size_t count = iov_iter_count(iter);
794 unsigned int saved_len;
795 size_t start;
796 unsigned int max_pages = iov_iter_npages(iter, INT_MAX);
797 struct page **pages = NULL;
798 struct bio_vec *bv = NULL;
799
800 if (iter->type & ITER_KVEC) {
801 memcpy(&ctx->iter, iter, sizeof(struct iov_iter));
802 ctx->len = count;
803 iov_iter_advance(iter, count);
804 return 0;
805 }
806
807 if (max_pages * sizeof(struct bio_vec) <= CIFS_AIO_KMALLOC_LIMIT)
808 bv = kmalloc_array(max_pages, sizeof(struct bio_vec),
809 GFP_KERNEL);
810
811 if (!bv) {
812 bv = vmalloc(array_size(max_pages, sizeof(struct bio_vec)));
813 if (!bv)
814 return -ENOMEM;
815 }
816
817 if (max_pages * sizeof(struct page *) <= CIFS_AIO_KMALLOC_LIMIT)
818 pages = kmalloc_array(max_pages, sizeof(struct page *),
819 GFP_KERNEL);
820
821 if (!pages) {
822 pages = vmalloc(array_size(max_pages, sizeof(struct page *)));
823 if (!pages) {
824 kvfree(bv);
825 return -ENOMEM;
826 }
827 }
828
829 saved_len = count;
830
831 while (count && npages < max_pages) {
832 rc = iov_iter_get_pages(iter, pages, count, max_pages, &start);
833 if (rc < 0) {
834 cifs_dbg(VFS, "couldn't get user pages (rc=%zd)\n", rc);
835 break;
836 }
837
838 if (rc > count) {
839 cifs_dbg(VFS, "get pages rc=%zd more than %zu\n", rc,
840 count);
841 break;
842 }
843
844 iov_iter_advance(iter, rc);
845 count -= rc;
846 rc += start;
847 cur_npages = DIV_ROUND_UP(rc, PAGE_SIZE);
848
849 if (npages + cur_npages > max_pages) {
850 cifs_dbg(VFS, "out of vec array capacity (%u vs %u)\n",
851 npages + cur_npages, max_pages);
852 break;
853 }
854
855 for (i = 0; i < cur_npages; i++) {
856 len = rc > PAGE_SIZE ? PAGE_SIZE : rc;
857 bv[npages + i].bv_page = pages[i];
858 bv[npages + i].bv_offset = start;
859 bv[npages + i].bv_len = len - start;
860 rc -= len;
861 start = 0;
862 }
863
864 npages += cur_npages;
865 }
866
867 kvfree(pages);
868 ctx->bv = bv;
869 ctx->len = saved_len - count;
870 ctx->npages = npages;
871 iov_iter_bvec(&ctx->iter, ITER_BVEC | rw, ctx->bv, npages, ctx->len);
872 return 0;
873 }
874
875 /**
876 * cifs_alloc_hash - allocate hash and hash context together
877 *
878 * The caller has to make sure @sdesc is initialized to either NULL or
879 * a valid context. Both can be freed via cifs_free_hash().
880 */
881 int
cifs_alloc_hash(const char * name,struct crypto_shash ** shash,struct sdesc ** sdesc)882 cifs_alloc_hash(const char *name,
883 struct crypto_shash **shash, struct sdesc **sdesc)
884 {
885 int rc = 0;
886 size_t size;
887
888 if (*sdesc != NULL)
889 return 0;
890
891 *shash = crypto_alloc_shash(name, 0, 0);
892 if (IS_ERR(*shash)) {
893 cifs_dbg(VFS, "could not allocate crypto %s\n", name);
894 rc = PTR_ERR(*shash);
895 *shash = NULL;
896 *sdesc = NULL;
897 return rc;
898 }
899
900 size = sizeof(struct shash_desc) + crypto_shash_descsize(*shash);
901 *sdesc = kmalloc(size, GFP_KERNEL);
902 if (*sdesc == NULL) {
903 cifs_dbg(VFS, "no memory left to allocate crypto %s\n", name);
904 crypto_free_shash(*shash);
905 *shash = NULL;
906 return -ENOMEM;
907 }
908
909 (*sdesc)->shash.tfm = *shash;
910 (*sdesc)->shash.flags = 0x0;
911 return 0;
912 }
913
914 /**
915 * cifs_free_hash - free hash and hash context together
916 *
917 * Freeing a NULL hash or context is safe.
918 */
919 void
cifs_free_hash(struct crypto_shash ** shash,struct sdesc ** sdesc)920 cifs_free_hash(struct crypto_shash **shash, struct sdesc **sdesc)
921 {
922 kfree(*sdesc);
923 *sdesc = NULL;
924 if (*shash)
925 crypto_free_shash(*shash);
926 *shash = NULL;
927 }
928
929 /**
930 * rqst_page_get_length - obtain the length and offset for a page in smb_rqst
931 * Input: rqst - a smb_rqst, page - a page index for rqst
932 * Output: *len - the length for this page, *offset - the offset for this page
933 */
rqst_page_get_length(struct smb_rqst * rqst,unsigned int page,unsigned int * len,unsigned int * offset)934 void rqst_page_get_length(struct smb_rqst *rqst, unsigned int page,
935 unsigned int *len, unsigned int *offset)
936 {
937 *len = rqst->rq_pagesz;
938 *offset = (page == 0) ? rqst->rq_offset : 0;
939
940 if (rqst->rq_npages == 1 || page == rqst->rq_npages-1)
941 *len = rqst->rq_tailsz;
942 else if (page == 0)
943 *len = rqst->rq_pagesz - rqst->rq_offset;
944 }
945