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
115 ret_buf = kzalloc(sizeof(*ret_buf), GFP_KERNEL);
116 if (!ret_buf)
117 return NULL;
118 ret_buf->crfid.fid = kzalloc(sizeof(*ret_buf->crfid.fid), GFP_KERNEL);
119 if (!ret_buf->crfid.fid) {
120 kfree(ret_buf);
121 return NULL;
122 }
123
124 atomic_inc(&tconInfoAllocCount);
125 ret_buf->tidStatus = CifsNew;
126 ++ret_buf->tc_count;
127 INIT_LIST_HEAD(&ret_buf->openFileList);
128 INIT_LIST_HEAD(&ret_buf->tcon_list);
129 spin_lock_init(&ret_buf->open_file_lock);
130 mutex_init(&ret_buf->crfid.fid_mutex);
131 spin_lock_init(&ret_buf->stat_lock);
132 atomic_set(&ret_buf->num_local_opens, 0);
133 atomic_set(&ret_buf->num_remote_opens, 0);
134
135 return ret_buf;
136 }
137
138 void
tconInfoFree(struct cifs_tcon * buf_to_free)139 tconInfoFree(struct cifs_tcon *buf_to_free)
140 {
141 if (buf_to_free == NULL) {
142 cifs_dbg(FYI, "Null buffer passed to tconInfoFree\n");
143 return;
144 }
145 atomic_dec(&tconInfoAllocCount);
146 kfree(buf_to_free->nativeFileSystem);
147 kzfree(buf_to_free->password);
148 kfree(buf_to_free->crfid.fid);
149 #ifdef CONFIG_CIFS_DFS_UPCALL
150 kfree(buf_to_free->dfs_path);
151 #endif
152 kfree(buf_to_free);
153 }
154
155 struct smb_hdr *
cifs_buf_get(void)156 cifs_buf_get(void)
157 {
158 struct smb_hdr *ret_buf = NULL;
159 /*
160 * SMB2 header is bigger than CIFS one - no problems to clean some
161 * more bytes for CIFS.
162 */
163 size_t buf_size = sizeof(struct smb2_sync_hdr);
164
165 /*
166 * We could use negotiated size instead of max_msgsize -
167 * but it may be more efficient to always alloc same size
168 * albeit slightly larger than necessary and maxbuffersize
169 * defaults to this and can not be bigger.
170 */
171 ret_buf = mempool_alloc(cifs_req_poolp, GFP_NOFS);
172
173 /* clear the first few header bytes */
174 /* for most paths, more is cleared in header_assemble */
175 memset(ret_buf, 0, buf_size + 3);
176 atomic_inc(&bufAllocCount);
177 #ifdef CONFIG_CIFS_STATS2
178 atomic_inc(&totBufAllocCount);
179 #endif /* CONFIG_CIFS_STATS2 */
180
181 return ret_buf;
182 }
183
184 void
cifs_buf_release(void * buf_to_free)185 cifs_buf_release(void *buf_to_free)
186 {
187 if (buf_to_free == NULL) {
188 /* cifs_dbg(FYI, "Null buffer passed to cifs_buf_release\n");*/
189 return;
190 }
191 mempool_free(buf_to_free, cifs_req_poolp);
192
193 atomic_dec(&bufAllocCount);
194 return;
195 }
196
197 struct smb_hdr *
cifs_small_buf_get(void)198 cifs_small_buf_get(void)
199 {
200 struct smb_hdr *ret_buf = NULL;
201
202 /* We could use negotiated size instead of max_msgsize -
203 but it may be more efficient to always alloc same size
204 albeit slightly larger than necessary and maxbuffersize
205 defaults to this and can not be bigger */
206 ret_buf = mempool_alloc(cifs_sm_req_poolp, GFP_NOFS);
207 /* No need to clear memory here, cleared in header assemble */
208 /* memset(ret_buf, 0, sizeof(struct smb_hdr) + 27);*/
209 atomic_inc(&smBufAllocCount);
210 #ifdef CONFIG_CIFS_STATS2
211 atomic_inc(&totSmBufAllocCount);
212 #endif /* CONFIG_CIFS_STATS2 */
213
214 return ret_buf;
215 }
216
217 void
cifs_small_buf_release(void * buf_to_free)218 cifs_small_buf_release(void *buf_to_free)
219 {
220
221 if (buf_to_free == NULL) {
222 cifs_dbg(FYI, "Null buffer passed to cifs_small_buf_release\n");
223 return;
224 }
225 mempool_free(buf_to_free, cifs_sm_req_poolp);
226
227 atomic_dec(&smBufAllocCount);
228 return;
229 }
230
231 void
free_rsp_buf(int resp_buftype,void * rsp)232 free_rsp_buf(int resp_buftype, void *rsp)
233 {
234 if (resp_buftype == CIFS_SMALL_BUFFER)
235 cifs_small_buf_release(rsp);
236 else if (resp_buftype == CIFS_LARGE_BUFFER)
237 cifs_buf_release(rsp);
238 }
239
240 /* NB: MID can not be set if treeCon not passed in, in that
241 case it is responsbility of caller to set the mid */
242 void
header_assemble(struct smb_hdr * buffer,char smb_command,const struct cifs_tcon * treeCon,int word_count)243 header_assemble(struct smb_hdr *buffer, char smb_command /* command */ ,
244 const struct cifs_tcon *treeCon, int word_count
245 /* length of fixed section (word count) in two byte units */)
246 {
247 char *temp = (char *) buffer;
248
249 memset(temp, 0, 256); /* bigger than MAX_CIFS_HDR_SIZE */
250
251 buffer->smb_buf_length = cpu_to_be32(
252 (2 * word_count) + sizeof(struct smb_hdr) -
253 4 /* RFC 1001 length field does not count */ +
254 2 /* for bcc field itself */) ;
255
256 buffer->Protocol[0] = 0xFF;
257 buffer->Protocol[1] = 'S';
258 buffer->Protocol[2] = 'M';
259 buffer->Protocol[3] = 'B';
260 buffer->Command = smb_command;
261 buffer->Flags = 0x00; /* case sensitive */
262 buffer->Flags2 = SMBFLG2_KNOWS_LONG_NAMES;
263 buffer->Pid = cpu_to_le16((__u16)current->tgid);
264 buffer->PidHigh = cpu_to_le16((__u16)(current->tgid >> 16));
265 if (treeCon) {
266 buffer->Tid = treeCon->tid;
267 if (treeCon->ses) {
268 if (treeCon->ses->capabilities & CAP_UNICODE)
269 buffer->Flags2 |= SMBFLG2_UNICODE;
270 if (treeCon->ses->capabilities & CAP_STATUS32)
271 buffer->Flags2 |= SMBFLG2_ERR_STATUS;
272
273 /* Uid is not converted */
274 buffer->Uid = treeCon->ses->Suid;
275 buffer->Mid = get_next_mid(treeCon->ses->server);
276 }
277 if (treeCon->Flags & SMB_SHARE_IS_IN_DFS)
278 buffer->Flags2 |= SMBFLG2_DFS;
279 if (treeCon->nocase)
280 buffer->Flags |= SMBFLG_CASELESS;
281 if ((treeCon->ses) && (treeCon->ses->server))
282 if (treeCon->ses->server->sign)
283 buffer->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
284 }
285
286 /* endian conversion of flags is now done just before sending */
287 buffer->WordCount = (char) word_count;
288 return;
289 }
290
291 static int
check_smb_hdr(struct smb_hdr * smb)292 check_smb_hdr(struct smb_hdr *smb)
293 {
294 /* does it have the right SMB "signature" ? */
295 if (*(__le32 *) smb->Protocol != cpu_to_le32(0x424d53ff)) {
296 cifs_dbg(VFS, "Bad protocol string signature header 0x%x\n",
297 *(unsigned int *)smb->Protocol);
298 return 1;
299 }
300
301 /* if it's a response then accept */
302 if (smb->Flags & SMBFLG_RESPONSE)
303 return 0;
304
305 /* only one valid case where server sends us request */
306 if (smb->Command == SMB_COM_LOCKING_ANDX)
307 return 0;
308
309 cifs_dbg(VFS, "Server sent request, not response. mid=%u\n",
310 get_mid(smb));
311 return 1;
312 }
313
314 int
checkSMB(char * buf,unsigned int total_read,struct TCP_Server_Info * server)315 checkSMB(char *buf, unsigned int total_read, struct TCP_Server_Info *server)
316 {
317 struct smb_hdr *smb = (struct smb_hdr *)buf;
318 __u32 rfclen = be32_to_cpu(smb->smb_buf_length);
319 __u32 clc_len; /* calculated length */
320 cifs_dbg(FYI, "checkSMB Length: 0x%x, smb_buf_length: 0x%x\n",
321 total_read, rfclen);
322
323 /* is this frame too small to even get to a BCC? */
324 if (total_read < 2 + sizeof(struct smb_hdr)) {
325 if ((total_read >= sizeof(struct smb_hdr) - 1)
326 && (smb->Status.CifsError != 0)) {
327 /* it's an error return */
328 smb->WordCount = 0;
329 /* some error cases do not return wct and bcc */
330 return 0;
331 } else if ((total_read == sizeof(struct smb_hdr) + 1) &&
332 (smb->WordCount == 0)) {
333 char *tmp = (char *)smb;
334 /* Need to work around a bug in two servers here */
335 /* First, check if the part of bcc they sent was zero */
336 if (tmp[sizeof(struct smb_hdr)] == 0) {
337 /* some servers return only half of bcc
338 * on simple responses (wct, bcc both zero)
339 * in particular have seen this on
340 * ulogoffX and FindClose. This leaves
341 * one byte of bcc potentially unitialized
342 */
343 /* zero rest of bcc */
344 tmp[sizeof(struct smb_hdr)+1] = 0;
345 return 0;
346 }
347 cifs_dbg(VFS, "rcvd invalid byte count (bcc)\n");
348 } else {
349 cifs_dbg(VFS, "Length less than smb header size\n");
350 }
351 return -EIO;
352 }
353
354 /* otherwise, there is enough to get to the BCC */
355 if (check_smb_hdr(smb))
356 return -EIO;
357 clc_len = smbCalcSize(smb, server);
358
359 if (4 + rfclen != total_read) {
360 cifs_dbg(VFS, "Length read does not match RFC1001 length %d\n",
361 rfclen);
362 return -EIO;
363 }
364
365 if (4 + rfclen != clc_len) {
366 __u16 mid = get_mid(smb);
367 /* check if bcc wrapped around for large read responses */
368 if ((rfclen > 64 * 1024) && (rfclen > clc_len)) {
369 /* check if lengths match mod 64K */
370 if (((4 + rfclen) & 0xFFFF) == (clc_len & 0xFFFF))
371 return 0; /* bcc wrapped */
372 }
373 cifs_dbg(FYI, "Calculated size %u vs length %u mismatch for mid=%u\n",
374 clc_len, 4 + rfclen, mid);
375
376 if (4 + rfclen < clc_len) {
377 cifs_dbg(VFS, "RFC1001 size %u smaller than SMB for mid=%u\n",
378 rfclen, mid);
379 return -EIO;
380 } else if (rfclen > clc_len + 512) {
381 /*
382 * Some servers (Windows XP in particular) send more
383 * data than the lengths in the SMB packet would
384 * indicate on certain calls (byte range locks and
385 * trans2 find first calls in particular). While the
386 * client can handle such a frame by ignoring the
387 * trailing data, we choose limit the amount of extra
388 * data to 512 bytes.
389 */
390 cifs_dbg(VFS, "RFC1001 size %u more than 512 bytes larger than SMB for mid=%u\n",
391 rfclen, mid);
392 return -EIO;
393 }
394 }
395 return 0;
396 }
397
398 bool
is_valid_oplock_break(char * buffer,struct TCP_Server_Info * srv)399 is_valid_oplock_break(char *buffer, struct TCP_Server_Info *srv)
400 {
401 struct smb_hdr *buf = (struct smb_hdr *)buffer;
402 struct smb_com_lock_req *pSMB = (struct smb_com_lock_req *)buf;
403 struct list_head *tmp, *tmp1, *tmp2;
404 struct cifs_ses *ses;
405 struct cifs_tcon *tcon;
406 struct cifsInodeInfo *pCifsInode;
407 struct cifsFileInfo *netfile;
408
409 cifs_dbg(FYI, "Checking for oplock break or dnotify response\n");
410 if ((pSMB->hdr.Command == SMB_COM_NT_TRANSACT) &&
411 (pSMB->hdr.Flags & SMBFLG_RESPONSE)) {
412 struct smb_com_transaction_change_notify_rsp *pSMBr =
413 (struct smb_com_transaction_change_notify_rsp *)buf;
414 struct file_notify_information *pnotify;
415 __u32 data_offset = 0;
416 size_t len = srv->total_read - sizeof(pSMBr->hdr.smb_buf_length);
417
418 if (get_bcc(buf) > sizeof(struct file_notify_information)) {
419 data_offset = le32_to_cpu(pSMBr->DataOffset);
420
421 if (data_offset >
422 len - sizeof(struct file_notify_information)) {
423 cifs_dbg(FYI, "invalid data_offset %u\n",
424 data_offset);
425 return true;
426 }
427 pnotify = (struct file_notify_information *)
428 ((char *)&pSMBr->hdr.Protocol + data_offset);
429 cifs_dbg(FYI, "dnotify on %s Action: 0x%x\n",
430 pnotify->FileName, pnotify->Action);
431 /* cifs_dump_mem("Rcvd notify Data: ",buf,
432 sizeof(struct smb_hdr)+60); */
433 return true;
434 }
435 if (pSMBr->hdr.Status.CifsError) {
436 cifs_dbg(FYI, "notify err 0x%x\n",
437 pSMBr->hdr.Status.CifsError);
438 return true;
439 }
440 return false;
441 }
442 if (pSMB->hdr.Command != SMB_COM_LOCKING_ANDX)
443 return false;
444 if (pSMB->hdr.Flags & SMBFLG_RESPONSE) {
445 /* no sense logging error on invalid handle on oplock
446 break - harmless race between close request and oplock
447 break response is expected from time to time writing out
448 large dirty files cached on the client */
449 if ((NT_STATUS_INVALID_HANDLE) ==
450 le32_to_cpu(pSMB->hdr.Status.CifsError)) {
451 cifs_dbg(FYI, "invalid handle on oplock break\n");
452 return true;
453 } else if (ERRbadfid ==
454 le16_to_cpu(pSMB->hdr.Status.DosError.Error)) {
455 return true;
456 } else {
457 return false; /* on valid oplock brk we get "request" */
458 }
459 }
460 if (pSMB->hdr.WordCount != 8)
461 return false;
462
463 cifs_dbg(FYI, "oplock type 0x%x level 0x%x\n",
464 pSMB->LockType, pSMB->OplockLevel);
465 if (!(pSMB->LockType & LOCKING_ANDX_OPLOCK_RELEASE))
466 return false;
467
468 /* look up tcon based on tid & uid */
469 spin_lock(&cifs_tcp_ses_lock);
470 list_for_each(tmp, &srv->smb_ses_list) {
471 ses = list_entry(tmp, struct cifs_ses, smb_ses_list);
472 list_for_each(tmp1, &ses->tcon_list) {
473 tcon = list_entry(tmp1, struct cifs_tcon, tcon_list);
474 if (tcon->tid != buf->Tid)
475 continue;
476
477 cifs_stats_inc(&tcon->stats.cifs_stats.num_oplock_brks);
478 spin_lock(&tcon->open_file_lock);
479 list_for_each(tmp2, &tcon->openFileList) {
480 netfile = list_entry(tmp2, struct cifsFileInfo,
481 tlist);
482 if (pSMB->Fid != netfile->fid.netfid)
483 continue;
484
485 cifs_dbg(FYI, "file id match, oplock break\n");
486 pCifsInode = CIFS_I(d_inode(netfile->dentry));
487
488 set_bit(CIFS_INODE_PENDING_OPLOCK_BREAK,
489 &pCifsInode->flags);
490
491 /*
492 * Set flag if the server downgrades the oplock
493 * to L2 else clear.
494 */
495 if (pSMB->OplockLevel)
496 set_bit(
497 CIFS_INODE_DOWNGRADE_OPLOCK_TO_L2,
498 &pCifsInode->flags);
499 else
500 clear_bit(
501 CIFS_INODE_DOWNGRADE_OPLOCK_TO_L2,
502 &pCifsInode->flags);
503
504 cifs_queue_oplock_break(netfile);
505 netfile->oplock_break_cancelled = false;
506
507 spin_unlock(&tcon->open_file_lock);
508 spin_unlock(&cifs_tcp_ses_lock);
509 return true;
510 }
511 spin_unlock(&tcon->open_file_lock);
512 spin_unlock(&cifs_tcp_ses_lock);
513 cifs_dbg(FYI, "No matching file for oplock break\n");
514 return true;
515 }
516 }
517 spin_unlock(&cifs_tcp_ses_lock);
518 cifs_dbg(FYI, "Can not process oplock break for non-existent connection\n");
519 return true;
520 }
521
522 void
dump_smb(void * buf,int smb_buf_length)523 dump_smb(void *buf, int smb_buf_length)
524 {
525 if (traceSMB == 0)
526 return;
527
528 print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_NONE, 8, 2, buf,
529 smb_buf_length, true);
530 }
531
532 void
cifs_autodisable_serverino(struct cifs_sb_info * cifs_sb)533 cifs_autodisable_serverino(struct cifs_sb_info *cifs_sb)
534 {
535 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) {
536 struct cifs_tcon *tcon = NULL;
537
538 if (cifs_sb->master_tlink)
539 tcon = cifs_sb_master_tcon(cifs_sb);
540
541 cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM;
542 cifs_sb->mnt_cifs_serverino_autodisabled = true;
543 cifs_dbg(VFS, "Autodisabling the use of server inode numbers on %s.\n",
544 tcon ? tcon->treeName : "new server");
545 cifs_dbg(VFS, "The server doesn't seem to support them properly or the files might be on different servers (DFS).\n");
546 cifs_dbg(VFS, "Hardlinks will not be recognized on this mount. Consider mounting with the \"noserverino\" option to silence this message.\n");
547
548 }
549 }
550
cifs_set_oplock_level(struct cifsInodeInfo * cinode,__u32 oplock)551 void cifs_set_oplock_level(struct cifsInodeInfo *cinode, __u32 oplock)
552 {
553 oplock &= 0xF;
554
555 if (oplock == OPLOCK_EXCLUSIVE) {
556 cinode->oplock = CIFS_CACHE_WRITE_FLG | CIFS_CACHE_READ_FLG;
557 cifs_dbg(FYI, "Exclusive Oplock granted on inode %p\n",
558 &cinode->vfs_inode);
559 } else if (oplock == OPLOCK_READ) {
560 cinode->oplock = CIFS_CACHE_READ_FLG;
561 cifs_dbg(FYI, "Level II Oplock granted on inode %p\n",
562 &cinode->vfs_inode);
563 } else
564 cinode->oplock = 0;
565 }
566
567 /*
568 * We wait for oplock breaks to be processed before we attempt to perform
569 * writes.
570 */
cifs_get_writer(struct cifsInodeInfo * cinode)571 int cifs_get_writer(struct cifsInodeInfo *cinode)
572 {
573 int rc;
574
575 start:
576 rc = wait_on_bit(&cinode->flags, CIFS_INODE_PENDING_OPLOCK_BREAK,
577 TASK_KILLABLE);
578 if (rc)
579 return rc;
580
581 spin_lock(&cinode->writers_lock);
582 if (!cinode->writers)
583 set_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags);
584 cinode->writers++;
585 /* Check to see if we have started servicing an oplock break */
586 if (test_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, &cinode->flags)) {
587 cinode->writers--;
588 if (cinode->writers == 0) {
589 clear_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags);
590 wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_WRITERS);
591 }
592 spin_unlock(&cinode->writers_lock);
593 goto start;
594 }
595 spin_unlock(&cinode->writers_lock);
596 return 0;
597 }
598
cifs_put_writer(struct cifsInodeInfo * cinode)599 void cifs_put_writer(struct cifsInodeInfo *cinode)
600 {
601 spin_lock(&cinode->writers_lock);
602 cinode->writers--;
603 if (cinode->writers == 0) {
604 clear_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags);
605 wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_WRITERS);
606 }
607 spin_unlock(&cinode->writers_lock);
608 }
609
610 /**
611 * cifs_queue_oplock_break - queue the oplock break handler for cfile
612 *
613 * This function is called from the demultiplex thread when it
614 * receives an oplock break for @cfile.
615 *
616 * Assumes the tcon->open_file_lock is held.
617 * Assumes cfile->file_info_lock is NOT held.
618 */
cifs_queue_oplock_break(struct cifsFileInfo * cfile)619 void cifs_queue_oplock_break(struct cifsFileInfo *cfile)
620 {
621 /*
622 * Bump the handle refcount now while we hold the
623 * open_file_lock to enforce the validity of it for the oplock
624 * break handler. The matching put is done at the end of the
625 * handler.
626 */
627 cifsFileInfo_get(cfile);
628
629 queue_work(cifsoplockd_wq, &cfile->oplock_break);
630 }
631
cifs_done_oplock_break(struct cifsInodeInfo * cinode)632 void cifs_done_oplock_break(struct cifsInodeInfo *cinode)
633 {
634 clear_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, &cinode->flags);
635 wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_OPLOCK_BREAK);
636 }
637
638 bool
backup_cred(struct cifs_sb_info * cifs_sb)639 backup_cred(struct cifs_sb_info *cifs_sb)
640 {
641 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPUID) {
642 if (uid_eq(cifs_sb->mnt_backupuid, current_fsuid()))
643 return true;
644 }
645 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPGID) {
646 if (in_group_p(cifs_sb->mnt_backupgid))
647 return true;
648 }
649
650 return false;
651 }
652
653 void
cifs_del_pending_open(struct cifs_pending_open * open)654 cifs_del_pending_open(struct cifs_pending_open *open)
655 {
656 spin_lock(&tlink_tcon(open->tlink)->open_file_lock);
657 list_del(&open->olist);
658 spin_unlock(&tlink_tcon(open->tlink)->open_file_lock);
659 }
660
661 void
cifs_add_pending_open_locked(struct cifs_fid * fid,struct tcon_link * tlink,struct cifs_pending_open * open)662 cifs_add_pending_open_locked(struct cifs_fid *fid, struct tcon_link *tlink,
663 struct cifs_pending_open *open)
664 {
665 memcpy(open->lease_key, fid->lease_key, SMB2_LEASE_KEY_SIZE);
666 open->oplock = CIFS_OPLOCK_NO_CHANGE;
667 open->tlink = tlink;
668 fid->pending_open = open;
669 list_add_tail(&open->olist, &tlink_tcon(tlink)->pending_opens);
670 }
671
672 void
cifs_add_pending_open(struct cifs_fid * fid,struct tcon_link * tlink,struct cifs_pending_open * open)673 cifs_add_pending_open(struct cifs_fid *fid, struct tcon_link *tlink,
674 struct cifs_pending_open *open)
675 {
676 spin_lock(&tlink_tcon(tlink)->open_file_lock);
677 cifs_add_pending_open_locked(fid, tlink, open);
678 spin_unlock(&tlink_tcon(open->tlink)->open_file_lock);
679 }
680
681 /* parses DFS refferal V3 structure
682 * caller is responsible for freeing target_nodes
683 * returns:
684 * - on success - 0
685 * - on failure - errno
686 */
687 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)688 parse_dfs_referrals(struct get_dfs_referral_rsp *rsp, u32 rsp_size,
689 unsigned int *num_of_nodes,
690 struct dfs_info3_param **target_nodes,
691 const struct nls_table *nls_codepage, int remap,
692 const char *searchName, bool is_unicode)
693 {
694 int i, rc = 0;
695 char *data_end;
696 struct dfs_referral_level_3 *ref;
697
698 *num_of_nodes = le16_to_cpu(rsp->NumberOfReferrals);
699
700 if (*num_of_nodes < 1) {
701 cifs_dbg(VFS, "num_referrals: must be at least > 0, but we get num_referrals = %d\n",
702 *num_of_nodes);
703 rc = -EINVAL;
704 goto parse_DFS_referrals_exit;
705 }
706
707 ref = (struct dfs_referral_level_3 *) &(rsp->referrals);
708 if (ref->VersionNumber != cpu_to_le16(3)) {
709 cifs_dbg(VFS, "Referrals of V%d version are not supported, should be V3\n",
710 le16_to_cpu(ref->VersionNumber));
711 rc = -EINVAL;
712 goto parse_DFS_referrals_exit;
713 }
714
715 /* get the upper boundary of the resp buffer */
716 data_end = (char *)rsp + rsp_size;
717
718 cifs_dbg(FYI, "num_referrals: %d dfs flags: 0x%x ...\n",
719 *num_of_nodes, le32_to_cpu(rsp->DFSFlags));
720
721 *target_nodes = kcalloc(*num_of_nodes, sizeof(struct dfs_info3_param),
722 GFP_KERNEL);
723 if (*target_nodes == NULL) {
724 rc = -ENOMEM;
725 goto parse_DFS_referrals_exit;
726 }
727
728 /* collect necessary data from referrals */
729 for (i = 0; i < *num_of_nodes; i++) {
730 char *temp;
731 int max_len;
732 struct dfs_info3_param *node = (*target_nodes)+i;
733
734 node->flags = le32_to_cpu(rsp->DFSFlags);
735 if (is_unicode) {
736 __le16 *tmp = kmalloc(strlen(searchName)*2 + 2,
737 GFP_KERNEL);
738 if (tmp == NULL) {
739 rc = -ENOMEM;
740 goto parse_DFS_referrals_exit;
741 }
742 cifsConvertToUTF16((__le16 *) tmp, searchName,
743 PATH_MAX, nls_codepage, remap);
744 node->path_consumed = cifs_utf16_bytes(tmp,
745 le16_to_cpu(rsp->PathConsumed),
746 nls_codepage);
747 kfree(tmp);
748 } else
749 node->path_consumed = le16_to_cpu(rsp->PathConsumed);
750
751 node->server_type = le16_to_cpu(ref->ServerType);
752 node->ref_flag = le16_to_cpu(ref->ReferralEntryFlags);
753
754 /* copy DfsPath */
755 temp = (char *)ref + le16_to_cpu(ref->DfsPathOffset);
756 max_len = data_end - temp;
757 node->path_name = cifs_strndup_from_utf16(temp, max_len,
758 is_unicode, nls_codepage);
759 if (!node->path_name) {
760 rc = -ENOMEM;
761 goto parse_DFS_referrals_exit;
762 }
763
764 /* copy link target UNC */
765 temp = (char *)ref + le16_to_cpu(ref->NetworkAddressOffset);
766 max_len = data_end - temp;
767 node->node_name = cifs_strndup_from_utf16(temp, max_len,
768 is_unicode, nls_codepage);
769 if (!node->node_name) {
770 rc = -ENOMEM;
771 goto parse_DFS_referrals_exit;
772 }
773
774 node->ttl = le32_to_cpu(ref->TimeToLive);
775
776 ref++;
777 }
778
779 parse_DFS_referrals_exit:
780 if (rc) {
781 free_dfs_info_array(*target_nodes, *num_of_nodes);
782 *target_nodes = NULL;
783 *num_of_nodes = 0;
784 }
785 return rc;
786 }
787
788 struct cifs_aio_ctx *
cifs_aio_ctx_alloc(void)789 cifs_aio_ctx_alloc(void)
790 {
791 struct cifs_aio_ctx *ctx;
792
793 /*
794 * Must use kzalloc to initialize ctx->bv to NULL and ctx->direct_io
795 * to false so that we know when we have to unreference pages within
796 * cifs_aio_ctx_release()
797 */
798 ctx = kzalloc(sizeof(struct cifs_aio_ctx), GFP_KERNEL);
799 if (!ctx)
800 return NULL;
801
802 INIT_LIST_HEAD(&ctx->list);
803 mutex_init(&ctx->aio_mutex);
804 init_completion(&ctx->done);
805 kref_init(&ctx->refcount);
806 return ctx;
807 }
808
809 void
cifs_aio_ctx_release(struct kref * refcount)810 cifs_aio_ctx_release(struct kref *refcount)
811 {
812 struct cifs_aio_ctx *ctx = container_of(refcount,
813 struct cifs_aio_ctx, refcount);
814
815 cifsFileInfo_put(ctx->cfile);
816
817 /*
818 * ctx->bv is only set if setup_aio_ctx_iter() was call successfuly
819 * which means that iov_iter_get_pages() was a success and thus that
820 * we have taken reference on pages.
821 */
822 if (ctx->bv) {
823 unsigned i;
824
825 for (i = 0; i < ctx->npages; i++) {
826 if (ctx->should_dirty)
827 set_page_dirty(ctx->bv[i].bv_page);
828 put_page(ctx->bv[i].bv_page);
829 }
830 kvfree(ctx->bv);
831 }
832
833 kfree(ctx);
834 }
835
836 #define CIFS_AIO_KMALLOC_LIMIT (1024 * 1024)
837
838 int
setup_aio_ctx_iter(struct cifs_aio_ctx * ctx,struct iov_iter * iter,int rw)839 setup_aio_ctx_iter(struct cifs_aio_ctx *ctx, struct iov_iter *iter, int rw)
840 {
841 ssize_t rc;
842 unsigned int cur_npages;
843 unsigned int npages = 0;
844 unsigned int i;
845 size_t len;
846 size_t count = iov_iter_count(iter);
847 unsigned int saved_len;
848 size_t start;
849 unsigned int max_pages = iov_iter_npages(iter, INT_MAX);
850 struct page **pages = NULL;
851 struct bio_vec *bv = NULL;
852
853 if (iov_iter_is_kvec(iter)) {
854 memcpy(&ctx->iter, iter, sizeof(struct iov_iter));
855 ctx->len = count;
856 iov_iter_advance(iter, count);
857 return 0;
858 }
859
860 if (max_pages * sizeof(struct bio_vec) <= CIFS_AIO_KMALLOC_LIMIT)
861 bv = kmalloc_array(max_pages, sizeof(struct bio_vec),
862 GFP_KERNEL);
863
864 if (!bv) {
865 bv = vmalloc(array_size(max_pages, sizeof(struct bio_vec)));
866 if (!bv)
867 return -ENOMEM;
868 }
869
870 if (max_pages * sizeof(struct page *) <= CIFS_AIO_KMALLOC_LIMIT)
871 pages = kmalloc_array(max_pages, sizeof(struct page *),
872 GFP_KERNEL);
873
874 if (!pages) {
875 pages = vmalloc(array_size(max_pages, sizeof(struct page *)));
876 if (!pages) {
877 kvfree(bv);
878 return -ENOMEM;
879 }
880 }
881
882 saved_len = count;
883
884 while (count && npages < max_pages) {
885 rc = iov_iter_get_pages(iter, pages, count, max_pages, &start);
886 if (rc < 0) {
887 cifs_dbg(VFS, "couldn't get user pages (rc=%zd)\n", rc);
888 break;
889 }
890
891 if (rc > count) {
892 cifs_dbg(VFS, "get pages rc=%zd more than %zu\n", rc,
893 count);
894 break;
895 }
896
897 iov_iter_advance(iter, rc);
898 count -= rc;
899 rc += start;
900 cur_npages = DIV_ROUND_UP(rc, PAGE_SIZE);
901
902 if (npages + cur_npages > max_pages) {
903 cifs_dbg(VFS, "out of vec array capacity (%u vs %u)\n",
904 npages + cur_npages, max_pages);
905 break;
906 }
907
908 for (i = 0; i < cur_npages; i++) {
909 len = rc > PAGE_SIZE ? PAGE_SIZE : rc;
910 bv[npages + i].bv_page = pages[i];
911 bv[npages + i].bv_offset = start;
912 bv[npages + i].bv_len = len - start;
913 rc -= len;
914 start = 0;
915 }
916
917 npages += cur_npages;
918 }
919
920 kvfree(pages);
921 ctx->bv = bv;
922 ctx->len = saved_len - count;
923 ctx->npages = npages;
924 iov_iter_bvec(&ctx->iter, rw, ctx->bv, npages, ctx->len);
925 return 0;
926 }
927
928 /**
929 * cifs_alloc_hash - allocate hash and hash context together
930 *
931 * The caller has to make sure @sdesc is initialized to either NULL or
932 * a valid context. Both can be freed via cifs_free_hash().
933 */
934 int
cifs_alloc_hash(const char * name,struct crypto_shash ** shash,struct sdesc ** sdesc)935 cifs_alloc_hash(const char *name,
936 struct crypto_shash **shash, struct sdesc **sdesc)
937 {
938 int rc = 0;
939 size_t size;
940
941 if (*sdesc != NULL)
942 return 0;
943
944 *shash = crypto_alloc_shash(name, 0, 0);
945 if (IS_ERR(*shash)) {
946 cifs_dbg(VFS, "could not allocate crypto %s\n", name);
947 rc = PTR_ERR(*shash);
948 *shash = NULL;
949 *sdesc = NULL;
950 return rc;
951 }
952
953 size = sizeof(struct shash_desc) + crypto_shash_descsize(*shash);
954 *sdesc = kmalloc(size, GFP_KERNEL);
955 if (*sdesc == NULL) {
956 cifs_dbg(VFS, "no memory left to allocate crypto %s\n", name);
957 crypto_free_shash(*shash);
958 *shash = NULL;
959 return -ENOMEM;
960 }
961
962 (*sdesc)->shash.tfm = *shash;
963 return 0;
964 }
965
966 /**
967 * cifs_free_hash - free hash and hash context together
968 *
969 * Freeing a NULL hash or context is safe.
970 */
971 void
cifs_free_hash(struct crypto_shash ** shash,struct sdesc ** sdesc)972 cifs_free_hash(struct crypto_shash **shash, struct sdesc **sdesc)
973 {
974 kfree(*sdesc);
975 *sdesc = NULL;
976 if (*shash)
977 crypto_free_shash(*shash);
978 *shash = NULL;
979 }
980
981 /**
982 * rqst_page_get_length - obtain the length and offset for a page in smb_rqst
983 * Input: rqst - a smb_rqst, page - a page index for rqst
984 * Output: *len - the length for this page, *offset - the offset for this page
985 */
rqst_page_get_length(struct smb_rqst * rqst,unsigned int page,unsigned int * len,unsigned int * offset)986 void rqst_page_get_length(struct smb_rqst *rqst, unsigned int page,
987 unsigned int *len, unsigned int *offset)
988 {
989 *len = rqst->rq_pagesz;
990 *offset = (page == 0) ? rqst->rq_offset : 0;
991
992 if (rqst->rq_npages == 1 || page == rqst->rq_npages-1)
993 *len = rqst->rq_tailsz;
994 else if (page == 0)
995 *len = rqst->rq_pagesz - rqst->rq_offset;
996 }
997
extract_unc_hostname(const char * unc,const char ** h,size_t * len)998 void extract_unc_hostname(const char *unc, const char **h, size_t *len)
999 {
1000 const char *end;
1001
1002 /* skip initial slashes */
1003 while (*unc && (*unc == '\\' || *unc == '/'))
1004 unc++;
1005
1006 end = unc;
1007
1008 while (*end && !(*end == '\\' || *end == '/'))
1009 end++;
1010
1011 *h = unc;
1012 *len = end - unc;
1013 }
1014
1015 /**
1016 * copy_path_name - copy src path to dst, possibly truncating
1017 *
1018 * returns number of bytes written (including trailing nul)
1019 */
copy_path_name(char * dst,const char * src)1020 int copy_path_name(char *dst, const char *src)
1021 {
1022 int name_len;
1023
1024 /*
1025 * PATH_MAX includes nul, so if strlen(src) >= PATH_MAX it
1026 * will truncate and strlen(dst) will be PATH_MAX-1
1027 */
1028 name_len = strscpy(dst, src, PATH_MAX);
1029 if (WARN_ON_ONCE(name_len < 0))
1030 name_len = PATH_MAX-1;
1031
1032 /* we count the trailing nul */
1033 name_len++;
1034 return name_len;
1035 }
1036