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 } else if (total_read < sizeof(*smb) + 2 * smb->WordCount) {
353 cifs_dbg(VFS, "%s: can't read BCC due to invalid WordCount(%u)\n",
354 __func__, smb->WordCount);
355 return -EIO;
356 }
357
358 /* otherwise, there is enough to get to the BCC */
359 if (check_smb_hdr(smb))
360 return -EIO;
361 clc_len = smbCalcSize(smb, server);
362
363 if (4 + rfclen != total_read) {
364 cifs_dbg(VFS, "Length read does not match RFC1001 length %d\n",
365 rfclen);
366 return -EIO;
367 }
368
369 if (4 + rfclen != clc_len) {
370 __u16 mid = get_mid(smb);
371 /* check if bcc wrapped around for large read responses */
372 if ((rfclen > 64 * 1024) && (rfclen > clc_len)) {
373 /* check if lengths match mod 64K */
374 if (((4 + rfclen) & 0xFFFF) == (clc_len & 0xFFFF))
375 return 0; /* bcc wrapped */
376 }
377 cifs_dbg(FYI, "Calculated size %u vs length %u mismatch for mid=%u\n",
378 clc_len, 4 + rfclen, mid);
379
380 if (4 + rfclen < clc_len) {
381 cifs_dbg(VFS, "RFC1001 size %u smaller than SMB for mid=%u\n",
382 rfclen, mid);
383 return -EIO;
384 } else if (rfclen > clc_len + 512) {
385 /*
386 * Some servers (Windows XP in particular) send more
387 * data than the lengths in the SMB packet would
388 * indicate on certain calls (byte range locks and
389 * trans2 find first calls in particular). While the
390 * client can handle such a frame by ignoring the
391 * trailing data, we choose limit the amount of extra
392 * data to 512 bytes.
393 */
394 cifs_dbg(VFS, "RFC1001 size %u more than 512 bytes larger than SMB for mid=%u\n",
395 rfclen, mid);
396 return -EIO;
397 }
398 }
399 return 0;
400 }
401
402 bool
is_valid_oplock_break(char * buffer,struct TCP_Server_Info * srv)403 is_valid_oplock_break(char *buffer, struct TCP_Server_Info *srv)
404 {
405 struct smb_hdr *buf = (struct smb_hdr *)buffer;
406 struct smb_com_lock_req *pSMB = (struct smb_com_lock_req *)buf;
407 struct list_head *tmp, *tmp1, *tmp2;
408 struct cifs_ses *ses;
409 struct cifs_tcon *tcon;
410 struct cifsInodeInfo *pCifsInode;
411 struct cifsFileInfo *netfile;
412
413 cifs_dbg(FYI, "Checking for oplock break or dnotify response\n");
414 if ((pSMB->hdr.Command == SMB_COM_NT_TRANSACT) &&
415 (pSMB->hdr.Flags & SMBFLG_RESPONSE)) {
416 struct smb_com_transaction_change_notify_rsp *pSMBr =
417 (struct smb_com_transaction_change_notify_rsp *)buf;
418 struct file_notify_information *pnotify;
419 __u32 data_offset = 0;
420 size_t len = srv->total_read - sizeof(pSMBr->hdr.smb_buf_length);
421
422 if (get_bcc(buf) > sizeof(struct file_notify_information)) {
423 data_offset = le32_to_cpu(pSMBr->DataOffset);
424
425 if (data_offset >
426 len - sizeof(struct file_notify_information)) {
427 cifs_dbg(FYI, "invalid data_offset %u\n",
428 data_offset);
429 return true;
430 }
431 pnotify = (struct file_notify_information *)
432 ((char *)&pSMBr->hdr.Protocol + data_offset);
433 cifs_dbg(FYI, "dnotify on %s Action: 0x%x\n",
434 pnotify->FileName, pnotify->Action);
435 /* cifs_dump_mem("Rcvd notify Data: ",buf,
436 sizeof(struct smb_hdr)+60); */
437 return true;
438 }
439 if (pSMBr->hdr.Status.CifsError) {
440 cifs_dbg(FYI, "notify err 0x%x\n",
441 pSMBr->hdr.Status.CifsError);
442 return true;
443 }
444 return false;
445 }
446 if (pSMB->hdr.Command != SMB_COM_LOCKING_ANDX)
447 return false;
448 if (pSMB->hdr.Flags & SMBFLG_RESPONSE) {
449 /* no sense logging error on invalid handle on oplock
450 break - harmless race between close request and oplock
451 break response is expected from time to time writing out
452 large dirty files cached on the client */
453 if ((NT_STATUS_INVALID_HANDLE) ==
454 le32_to_cpu(pSMB->hdr.Status.CifsError)) {
455 cifs_dbg(FYI, "invalid handle on oplock break\n");
456 return true;
457 } else if (ERRbadfid ==
458 le16_to_cpu(pSMB->hdr.Status.DosError.Error)) {
459 return true;
460 } else {
461 return false; /* on valid oplock brk we get "request" */
462 }
463 }
464 if (pSMB->hdr.WordCount != 8)
465 return false;
466
467 cifs_dbg(FYI, "oplock type 0x%x level 0x%x\n",
468 pSMB->LockType, pSMB->OplockLevel);
469 if (!(pSMB->LockType & LOCKING_ANDX_OPLOCK_RELEASE))
470 return false;
471
472 /* look up tcon based on tid & uid */
473 spin_lock(&cifs_tcp_ses_lock);
474 list_for_each(tmp, &srv->smb_ses_list) {
475 ses = list_entry(tmp, struct cifs_ses, smb_ses_list);
476 list_for_each(tmp1, &ses->tcon_list) {
477 tcon = list_entry(tmp1, struct cifs_tcon, tcon_list);
478 if (tcon->tid != buf->Tid)
479 continue;
480
481 cifs_stats_inc(&tcon->stats.cifs_stats.num_oplock_brks);
482 spin_lock(&tcon->open_file_lock);
483 list_for_each(tmp2, &tcon->openFileList) {
484 netfile = list_entry(tmp2, struct cifsFileInfo,
485 tlist);
486 if (pSMB->Fid != netfile->fid.netfid)
487 continue;
488
489 cifs_dbg(FYI, "file id match, oplock break\n");
490 pCifsInode = CIFS_I(d_inode(netfile->dentry));
491
492 set_bit(CIFS_INODE_PENDING_OPLOCK_BREAK,
493 &pCifsInode->flags);
494
495 netfile->oplock_epoch = 0;
496 netfile->oplock_level = pSMB->OplockLevel;
497 netfile->oplock_break_cancelled = false;
498 cifs_queue_oplock_break(netfile);
499
500 spin_unlock(&tcon->open_file_lock);
501 spin_unlock(&cifs_tcp_ses_lock);
502 return true;
503 }
504 spin_unlock(&tcon->open_file_lock);
505 spin_unlock(&cifs_tcp_ses_lock);
506 cifs_dbg(FYI, "No matching file for oplock break\n");
507 return true;
508 }
509 }
510 spin_unlock(&cifs_tcp_ses_lock);
511 cifs_dbg(FYI, "Can not process oplock break for non-existent connection\n");
512 return true;
513 }
514
515 void
dump_smb(void * buf,int smb_buf_length)516 dump_smb(void *buf, int smb_buf_length)
517 {
518 if (traceSMB == 0)
519 return;
520
521 print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_NONE, 8, 2, buf,
522 smb_buf_length, true);
523 }
524
525 void
cifs_autodisable_serverino(struct cifs_sb_info * cifs_sb)526 cifs_autodisable_serverino(struct cifs_sb_info *cifs_sb)
527 {
528 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) {
529 struct cifs_tcon *tcon = NULL;
530
531 if (cifs_sb->master_tlink)
532 tcon = cifs_sb_master_tcon(cifs_sb);
533
534 cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM;
535 cifs_sb->mnt_cifs_serverino_autodisabled = true;
536 cifs_dbg(VFS, "Autodisabling the use of server inode numbers on %s.\n",
537 tcon ? tcon->treeName : "new server");
538 cifs_dbg(VFS, "The server doesn't seem to support them properly or the files might be on different servers (DFS).\n");
539 cifs_dbg(VFS, "Hardlinks will not be recognized on this mount. Consider mounting with the \"noserverino\" option to silence this message.\n");
540
541 }
542 }
543
cifs_set_oplock_level(struct cifsInodeInfo * cinode,__u32 oplock)544 void cifs_set_oplock_level(struct cifsInodeInfo *cinode, __u32 oplock)
545 {
546 oplock &= 0xF;
547
548 if (oplock == OPLOCK_EXCLUSIVE) {
549 cinode->oplock = CIFS_CACHE_WRITE_FLG | CIFS_CACHE_READ_FLG;
550 cifs_dbg(FYI, "Exclusive Oplock granted on inode %p\n",
551 &cinode->vfs_inode);
552 } else if (oplock == OPLOCK_READ) {
553 cinode->oplock = CIFS_CACHE_READ_FLG;
554 cifs_dbg(FYI, "Level II Oplock granted on inode %p\n",
555 &cinode->vfs_inode);
556 } else
557 cinode->oplock = 0;
558 }
559
560 /*
561 * We wait for oplock breaks to be processed before we attempt to perform
562 * writes.
563 */
cifs_get_writer(struct cifsInodeInfo * cinode)564 int cifs_get_writer(struct cifsInodeInfo *cinode)
565 {
566 int rc;
567
568 start:
569 rc = wait_on_bit(&cinode->flags, CIFS_INODE_PENDING_OPLOCK_BREAK,
570 TASK_KILLABLE);
571 if (rc)
572 return rc;
573
574 spin_lock(&cinode->writers_lock);
575 if (!cinode->writers)
576 set_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags);
577 cinode->writers++;
578 /* Check to see if we have started servicing an oplock break */
579 if (test_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, &cinode->flags)) {
580 cinode->writers--;
581 if (cinode->writers == 0) {
582 clear_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags);
583 wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_WRITERS);
584 }
585 spin_unlock(&cinode->writers_lock);
586 goto start;
587 }
588 spin_unlock(&cinode->writers_lock);
589 return 0;
590 }
591
cifs_put_writer(struct cifsInodeInfo * cinode)592 void cifs_put_writer(struct cifsInodeInfo *cinode)
593 {
594 spin_lock(&cinode->writers_lock);
595 cinode->writers--;
596 if (cinode->writers == 0) {
597 clear_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags);
598 wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_WRITERS);
599 }
600 spin_unlock(&cinode->writers_lock);
601 }
602
603 /**
604 * cifs_queue_oplock_break - queue the oplock break handler for cfile
605 *
606 * This function is called from the demultiplex thread when it
607 * receives an oplock break for @cfile.
608 *
609 * Assumes the tcon->open_file_lock is held.
610 * Assumes cfile->file_info_lock is NOT held.
611 */
cifs_queue_oplock_break(struct cifsFileInfo * cfile)612 void cifs_queue_oplock_break(struct cifsFileInfo *cfile)
613 {
614 /*
615 * Bump the handle refcount now while we hold the
616 * open_file_lock to enforce the validity of it for the oplock
617 * break handler. The matching put is done at the end of the
618 * handler.
619 */
620 cifsFileInfo_get(cfile);
621
622 queue_work(cifsoplockd_wq, &cfile->oplock_break);
623 }
624
cifs_done_oplock_break(struct cifsInodeInfo * cinode)625 void cifs_done_oplock_break(struct cifsInodeInfo *cinode)
626 {
627 clear_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, &cinode->flags);
628 wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_OPLOCK_BREAK);
629 }
630
631 bool
backup_cred(struct cifs_sb_info * cifs_sb)632 backup_cred(struct cifs_sb_info *cifs_sb)
633 {
634 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPUID) {
635 if (uid_eq(cifs_sb->mnt_backupuid, current_fsuid()))
636 return true;
637 }
638 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPGID) {
639 if (in_group_p(cifs_sb->mnt_backupgid))
640 return true;
641 }
642
643 return false;
644 }
645
646 void
cifs_del_pending_open(struct cifs_pending_open * open)647 cifs_del_pending_open(struct cifs_pending_open *open)
648 {
649 spin_lock(&tlink_tcon(open->tlink)->open_file_lock);
650 list_del(&open->olist);
651 spin_unlock(&tlink_tcon(open->tlink)->open_file_lock);
652 }
653
654 void
cifs_add_pending_open_locked(struct cifs_fid * fid,struct tcon_link * tlink,struct cifs_pending_open * open)655 cifs_add_pending_open_locked(struct cifs_fid *fid, struct tcon_link *tlink,
656 struct cifs_pending_open *open)
657 {
658 memcpy(open->lease_key, fid->lease_key, SMB2_LEASE_KEY_SIZE);
659 open->oplock = CIFS_OPLOCK_NO_CHANGE;
660 open->tlink = tlink;
661 fid->pending_open = open;
662 list_add_tail(&open->olist, &tlink_tcon(tlink)->pending_opens);
663 }
664
665 void
cifs_add_pending_open(struct cifs_fid * fid,struct tcon_link * tlink,struct cifs_pending_open * open)666 cifs_add_pending_open(struct cifs_fid *fid, struct tcon_link *tlink,
667 struct cifs_pending_open *open)
668 {
669 spin_lock(&tlink_tcon(tlink)->open_file_lock);
670 cifs_add_pending_open_locked(fid, tlink, open);
671 spin_unlock(&tlink_tcon(open->tlink)->open_file_lock);
672 }
673
674 /* parses DFS refferal V3 structure
675 * caller is responsible for freeing target_nodes
676 * returns:
677 * - on success - 0
678 * - on failure - errno
679 */
680 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)681 parse_dfs_referrals(struct get_dfs_referral_rsp *rsp, u32 rsp_size,
682 unsigned int *num_of_nodes,
683 struct dfs_info3_param **target_nodes,
684 const struct nls_table *nls_codepage, int remap,
685 const char *searchName, bool is_unicode)
686 {
687 int i, rc = 0;
688 char *data_end;
689 struct dfs_referral_level_3 *ref;
690
691 *num_of_nodes = le16_to_cpu(rsp->NumberOfReferrals);
692
693 if (*num_of_nodes < 1) {
694 cifs_dbg(VFS, "num_referrals: must be at least > 0, but we get num_referrals = %d\n",
695 *num_of_nodes);
696 rc = -EINVAL;
697 goto parse_DFS_referrals_exit;
698 }
699
700 ref = (struct dfs_referral_level_3 *) &(rsp->referrals);
701 if (ref->VersionNumber != cpu_to_le16(3)) {
702 cifs_dbg(VFS, "Referrals of V%d version are not supported, should be V3\n",
703 le16_to_cpu(ref->VersionNumber));
704 rc = -EINVAL;
705 goto parse_DFS_referrals_exit;
706 }
707
708 /* get the upper boundary of the resp buffer */
709 data_end = (char *)rsp + rsp_size;
710
711 cifs_dbg(FYI, "num_referrals: %d dfs flags: 0x%x ...\n",
712 *num_of_nodes, le32_to_cpu(rsp->DFSFlags));
713
714 *target_nodes = kcalloc(*num_of_nodes, sizeof(struct dfs_info3_param),
715 GFP_KERNEL);
716 if (*target_nodes == NULL) {
717 rc = -ENOMEM;
718 goto parse_DFS_referrals_exit;
719 }
720
721 /* collect necessary data from referrals */
722 for (i = 0; i < *num_of_nodes; i++) {
723 char *temp;
724 int max_len;
725 struct dfs_info3_param *node = (*target_nodes)+i;
726
727 node->flags = le32_to_cpu(rsp->DFSFlags);
728 if (is_unicode) {
729 __le16 *tmp = kmalloc(strlen(searchName)*2 + 2,
730 GFP_KERNEL);
731 if (tmp == NULL) {
732 rc = -ENOMEM;
733 goto parse_DFS_referrals_exit;
734 }
735 cifsConvertToUTF16((__le16 *) tmp, searchName,
736 PATH_MAX, nls_codepage, remap);
737 node->path_consumed = cifs_utf16_bytes(tmp,
738 le16_to_cpu(rsp->PathConsumed),
739 nls_codepage);
740 kfree(tmp);
741 } else
742 node->path_consumed = le16_to_cpu(rsp->PathConsumed);
743
744 node->server_type = le16_to_cpu(ref->ServerType);
745 node->ref_flag = le16_to_cpu(ref->ReferralEntryFlags);
746
747 /* copy DfsPath */
748 temp = (char *)ref + le16_to_cpu(ref->DfsPathOffset);
749 max_len = data_end - temp;
750 node->path_name = cifs_strndup_from_utf16(temp, max_len,
751 is_unicode, nls_codepage);
752 if (!node->path_name) {
753 rc = -ENOMEM;
754 goto parse_DFS_referrals_exit;
755 }
756
757 /* copy link target UNC */
758 temp = (char *)ref + le16_to_cpu(ref->NetworkAddressOffset);
759 max_len = data_end - temp;
760 node->node_name = cifs_strndup_from_utf16(temp, max_len,
761 is_unicode, nls_codepage);
762 if (!node->node_name) {
763 rc = -ENOMEM;
764 goto parse_DFS_referrals_exit;
765 }
766
767 node->ttl = le32_to_cpu(ref->TimeToLive);
768
769 ref++;
770 }
771
772 parse_DFS_referrals_exit:
773 if (rc) {
774 free_dfs_info_array(*target_nodes, *num_of_nodes);
775 *target_nodes = NULL;
776 *num_of_nodes = 0;
777 }
778 return rc;
779 }
780
781 struct cifs_aio_ctx *
cifs_aio_ctx_alloc(void)782 cifs_aio_ctx_alloc(void)
783 {
784 struct cifs_aio_ctx *ctx;
785
786 /*
787 * Must use kzalloc to initialize ctx->bv to NULL and ctx->direct_io
788 * to false so that we know when we have to unreference pages within
789 * cifs_aio_ctx_release()
790 */
791 ctx = kzalloc(sizeof(struct cifs_aio_ctx), GFP_KERNEL);
792 if (!ctx)
793 return NULL;
794
795 INIT_LIST_HEAD(&ctx->list);
796 mutex_init(&ctx->aio_mutex);
797 init_completion(&ctx->done);
798 kref_init(&ctx->refcount);
799 return ctx;
800 }
801
802 void
cifs_aio_ctx_release(struct kref * refcount)803 cifs_aio_ctx_release(struct kref *refcount)
804 {
805 struct cifs_aio_ctx *ctx = container_of(refcount,
806 struct cifs_aio_ctx, refcount);
807
808 cifsFileInfo_put(ctx->cfile);
809
810 /*
811 * ctx->bv is only set if setup_aio_ctx_iter() was call successfuly
812 * which means that iov_iter_get_pages() was a success and thus that
813 * we have taken reference on pages.
814 */
815 if (ctx->bv) {
816 unsigned i;
817
818 for (i = 0; i < ctx->npages; i++) {
819 if (ctx->should_dirty)
820 set_page_dirty(ctx->bv[i].bv_page);
821 put_page(ctx->bv[i].bv_page);
822 }
823 kvfree(ctx->bv);
824 }
825
826 kfree(ctx);
827 }
828
829 #define CIFS_AIO_KMALLOC_LIMIT (1024 * 1024)
830
831 int
setup_aio_ctx_iter(struct cifs_aio_ctx * ctx,struct iov_iter * iter,int rw)832 setup_aio_ctx_iter(struct cifs_aio_ctx *ctx, struct iov_iter *iter, int rw)
833 {
834 ssize_t rc;
835 unsigned int cur_npages;
836 unsigned int npages = 0;
837 unsigned int i;
838 size_t len;
839 size_t count = iov_iter_count(iter);
840 unsigned int saved_len;
841 size_t start;
842 unsigned int max_pages = iov_iter_npages(iter, INT_MAX);
843 struct page **pages = NULL;
844 struct bio_vec *bv = NULL;
845
846 if (iov_iter_is_kvec(iter)) {
847 memcpy(&ctx->iter, iter, sizeof(struct iov_iter));
848 ctx->len = count;
849 iov_iter_advance(iter, count);
850 return 0;
851 }
852
853 if (max_pages * sizeof(struct bio_vec) <= CIFS_AIO_KMALLOC_LIMIT)
854 bv = kmalloc_array(max_pages, sizeof(struct bio_vec),
855 GFP_KERNEL);
856
857 if (!bv) {
858 bv = vmalloc(array_size(max_pages, sizeof(struct bio_vec)));
859 if (!bv)
860 return -ENOMEM;
861 }
862
863 if (max_pages * sizeof(struct page *) <= CIFS_AIO_KMALLOC_LIMIT)
864 pages = kmalloc_array(max_pages, sizeof(struct page *),
865 GFP_KERNEL);
866
867 if (!pages) {
868 pages = vmalloc(array_size(max_pages, sizeof(struct page *)));
869 if (!pages) {
870 kvfree(bv);
871 return -ENOMEM;
872 }
873 }
874
875 saved_len = count;
876
877 while (count && npages < max_pages) {
878 rc = iov_iter_get_pages(iter, pages, count, max_pages, &start);
879 if (rc < 0) {
880 cifs_dbg(VFS, "couldn't get user pages (rc=%zd)\n", rc);
881 break;
882 }
883
884 if (rc > count) {
885 cifs_dbg(VFS, "get pages rc=%zd more than %zu\n", rc,
886 count);
887 break;
888 }
889
890 iov_iter_advance(iter, rc);
891 count -= rc;
892 rc += start;
893 cur_npages = DIV_ROUND_UP(rc, PAGE_SIZE);
894
895 if (npages + cur_npages > max_pages) {
896 cifs_dbg(VFS, "out of vec array capacity (%u vs %u)\n",
897 npages + cur_npages, max_pages);
898 break;
899 }
900
901 for (i = 0; i < cur_npages; i++) {
902 len = rc > PAGE_SIZE ? PAGE_SIZE : rc;
903 bv[npages + i].bv_page = pages[i];
904 bv[npages + i].bv_offset = start;
905 bv[npages + i].bv_len = len - start;
906 rc -= len;
907 start = 0;
908 }
909
910 npages += cur_npages;
911 }
912
913 kvfree(pages);
914 ctx->bv = bv;
915 ctx->len = saved_len - count;
916 ctx->npages = npages;
917 iov_iter_bvec(&ctx->iter, rw, ctx->bv, npages, ctx->len);
918 return 0;
919 }
920
921 /**
922 * cifs_alloc_hash - allocate hash and hash context together
923 *
924 * The caller has to make sure @sdesc is initialized to either NULL or
925 * a valid context. Both can be freed via cifs_free_hash().
926 */
927 int
cifs_alloc_hash(const char * name,struct crypto_shash ** shash,struct sdesc ** sdesc)928 cifs_alloc_hash(const char *name,
929 struct crypto_shash **shash, struct sdesc **sdesc)
930 {
931 int rc = 0;
932 size_t size;
933
934 if (*sdesc != NULL)
935 return 0;
936
937 *shash = crypto_alloc_shash(name, 0, 0);
938 if (IS_ERR(*shash)) {
939 cifs_dbg(VFS, "could not allocate crypto %s\n", name);
940 rc = PTR_ERR(*shash);
941 *shash = NULL;
942 *sdesc = NULL;
943 return rc;
944 }
945
946 size = sizeof(struct shash_desc) + crypto_shash_descsize(*shash);
947 *sdesc = kmalloc(size, GFP_KERNEL);
948 if (*sdesc == NULL) {
949 cifs_dbg(VFS, "no memory left to allocate crypto %s\n", name);
950 crypto_free_shash(*shash);
951 *shash = NULL;
952 return -ENOMEM;
953 }
954
955 (*sdesc)->shash.tfm = *shash;
956 return 0;
957 }
958
959 /**
960 * cifs_free_hash - free hash and hash context together
961 *
962 * Freeing a NULL hash or context is safe.
963 */
964 void
cifs_free_hash(struct crypto_shash ** shash,struct sdesc ** sdesc)965 cifs_free_hash(struct crypto_shash **shash, struct sdesc **sdesc)
966 {
967 kfree(*sdesc);
968 *sdesc = NULL;
969 if (*shash)
970 crypto_free_shash(*shash);
971 *shash = NULL;
972 }
973
974 /**
975 * rqst_page_get_length - obtain the length and offset for a page in smb_rqst
976 * Input: rqst - a smb_rqst, page - a page index for rqst
977 * Output: *len - the length for this page, *offset - the offset for this page
978 */
rqst_page_get_length(const struct smb_rqst * rqst,unsigned int page,unsigned int * len,unsigned int * offset)979 void rqst_page_get_length(const struct smb_rqst *rqst, unsigned int page,
980 unsigned int *len, unsigned int *offset)
981 {
982 *len = rqst->rq_pagesz;
983 *offset = (page == 0) ? rqst->rq_offset : 0;
984
985 if (rqst->rq_npages == 1 || page == rqst->rq_npages-1)
986 *len = rqst->rq_tailsz;
987 else if (page == 0)
988 *len = rqst->rq_pagesz - rqst->rq_offset;
989 }
990
extract_unc_hostname(const char * unc,const char ** h,size_t * len)991 void extract_unc_hostname(const char *unc, const char **h, size_t *len)
992 {
993 const char *end;
994
995 /* skip initial slashes */
996 while (*unc && (*unc == '\\' || *unc == '/'))
997 unc++;
998
999 end = unc;
1000
1001 while (*end && !(*end == '\\' || *end == '/'))
1002 end++;
1003
1004 *h = unc;
1005 *len = end - unc;
1006 }
1007
1008 /**
1009 * copy_path_name - copy src path to dst, possibly truncating
1010 *
1011 * returns number of bytes written (including trailing nul)
1012 */
copy_path_name(char * dst,const char * src)1013 int copy_path_name(char *dst, const char *src)
1014 {
1015 int name_len;
1016
1017 /*
1018 * PATH_MAX includes nul, so if strlen(src) >= PATH_MAX it
1019 * will truncate and strlen(dst) will be PATH_MAX-1
1020 */
1021 name_len = strscpy(dst, src, PATH_MAX);
1022 if (WARN_ON_ONCE(name_len < 0))
1023 name_len = PATH_MAX-1;
1024
1025 /* we count the trailing nul */
1026 name_len++;
1027 return name_len;
1028 }
1029