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1/*
2 * fs/cifs/misc.c
3 *
4 * Copyright (C) International Business Machines Corp., 2002,2008
5 * Author(s): Steve French (sfrench@us.ibm.com)
6 *
7 * This library is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU Lesser General Public License as published
9 * by the Free Software Foundation; either version 2.1 of the License, or
10 * (at your option) any later version.
11 *
12 * This library is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
15 * the GNU Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public License
18 * along with this library; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 */
21
22#include <linux/slab.h>
23#include <linux/ctype.h>
24#include <linux/mempool.h>
25#include <linux/vmalloc.h>
26#include "cifspdu.h"
27#include "cifsglob.h"
28#include "cifsproto.h"
29#include "cifs_debug.h"
30#include "smberr.h"
31#include "nterr.h"
32#include "cifs_unicode.h"
33#include "smb2pdu.h"
34
35extern mempool_t *cifs_sm_req_poolp;
36extern mempool_t *cifs_req_poolp;
37
38/* The xid serves as a useful identifier for each incoming vfs request,
39 in a similar way to the mid which is useful to track each sent smb,
40 and CurrentXid can also provide a running counter (although it
41 will eventually wrap past zero) of the total vfs operations handled
42 since the cifs fs was mounted */
43
44unsigned int
45_get_xid(void)
46{
47 unsigned int xid;
48
49 spin_lock(&GlobalMid_Lock);
50 GlobalTotalActiveXid++;
51
52 /* keep high water mark for number of simultaneous ops in filesystem */
53 if (GlobalTotalActiveXid > GlobalMaxActiveXid)
54 GlobalMaxActiveXid = GlobalTotalActiveXid;
55 if (GlobalTotalActiveXid > 65000)
56 cifs_dbg(FYI, "warning: more than 65000 requests active\n");
57 xid = GlobalCurrentXid++;
58 spin_unlock(&GlobalMid_Lock);
59 return xid;
60}
61
62void
63_free_xid(unsigned int xid)
64{
65 spin_lock(&GlobalMid_Lock);
66 /* if (GlobalTotalActiveXid == 0)
67 BUG(); */
68 GlobalTotalActiveXid--;
69 spin_unlock(&GlobalMid_Lock);
70}
71
72struct cifs_ses *
73sesInfoAlloc(void)
74{
75 struct cifs_ses *ret_buf;
76
77 ret_buf = kzalloc(sizeof(struct cifs_ses), GFP_KERNEL);
78 if (ret_buf) {
79 atomic_inc(&sesInfoAllocCount);
80 ret_buf->status = CifsNew;
81 ++ret_buf->ses_count;
82 INIT_LIST_HEAD(&ret_buf->smb_ses_list);
83 INIT_LIST_HEAD(&ret_buf->tcon_list);
84 mutex_init(&ret_buf->session_mutex);
85 }
86 return ret_buf;
87}
88
89void
90sesInfoFree(struct cifs_ses *buf_to_free)
91{
92 if (buf_to_free == NULL) {
93 cifs_dbg(FYI, "Null buffer passed to sesInfoFree\n");
94 return;
95 }
96
97 atomic_dec(&sesInfoAllocCount);
98 kfree(buf_to_free->serverOS);
99 kfree(buf_to_free->serverDomain);
100 kfree(buf_to_free->serverNOS);
101 kzfree(buf_to_free->password);
102 kfree(buf_to_free->user_name);
103 kfree(buf_to_free->domainName);
104 kzfree(buf_to_free->auth_key.response);
105 kzfree(buf_to_free);
106}
107
108struct cifs_tcon *
109tconInfoAlloc(void)
110{
111 struct cifs_tcon *ret_buf;
112 ret_buf = kzalloc(sizeof(struct cifs_tcon), GFP_KERNEL);
113 if (ret_buf) {
114 atomic_inc(&tconInfoAllocCount);
115 ret_buf->tidStatus = CifsNew;
116 ++ret_buf->tc_count;
117 INIT_LIST_HEAD(&ret_buf->openFileList);
118 INIT_LIST_HEAD(&ret_buf->tcon_list);
119 spin_lock_init(&ret_buf->open_file_lock);
120#ifdef CONFIG_CIFS_STATS
121 spin_lock_init(&ret_buf->stat_lock);
122#endif
123 }
124 return ret_buf;
125}
126
127void
128tconInfoFree(struct cifs_tcon *buf_to_free)
129{
130 if (buf_to_free == NULL) {
131 cifs_dbg(FYI, "Null buffer passed to tconInfoFree\n");
132 return;
133 }
134 atomic_dec(&tconInfoAllocCount);
135 kfree(buf_to_free->nativeFileSystem);
136 kzfree(buf_to_free->password);
137 kfree(buf_to_free);
138}
139
140struct smb_hdr *
141cifs_buf_get(void)
142{
143 struct smb_hdr *ret_buf = NULL;
144 /*
145 * SMB2 header is bigger than CIFS one - no problems to clean some
146 * more bytes for CIFS.
147 */
148 size_t buf_size = sizeof(struct smb2_hdr);
149
150 /*
151 * We could use negotiated size instead of max_msgsize -
152 * but it may be more efficient to always alloc same size
153 * albeit slightly larger than necessary and maxbuffersize
154 * defaults to this and can not be bigger.
155 */
156 ret_buf = mempool_alloc(cifs_req_poolp, GFP_NOFS);
157
158 /* clear the first few header bytes */
159 /* for most paths, more is cleared in header_assemble */
160 memset(ret_buf, 0, buf_size + 3);
161 atomic_inc(&bufAllocCount);
162#ifdef CONFIG_CIFS_STATS2
163 atomic_inc(&totBufAllocCount);
164#endif /* CONFIG_CIFS_STATS2 */
165
166 return ret_buf;
167}
168
169void
170cifs_buf_release(void *buf_to_free)
171{
172 if (buf_to_free == NULL) {
173 /* cifs_dbg(FYI, "Null buffer passed to cifs_buf_release\n");*/
174 return;
175 }
176 mempool_free(buf_to_free, cifs_req_poolp);
177
178 atomic_dec(&bufAllocCount);
179 return;
180}
181
182struct smb_hdr *
183cifs_small_buf_get(void)
184{
185 struct smb_hdr *ret_buf = NULL;
186
187/* We could use negotiated size instead of max_msgsize -
188 but it may be more efficient to always alloc same size
189 albeit slightly larger than necessary and maxbuffersize
190 defaults to this and can not be bigger */
191 ret_buf = mempool_alloc(cifs_sm_req_poolp, GFP_NOFS);
192 /* No need to clear memory here, cleared in header assemble */
193 /* memset(ret_buf, 0, sizeof(struct smb_hdr) + 27);*/
194 atomic_inc(&smBufAllocCount);
195#ifdef CONFIG_CIFS_STATS2
196 atomic_inc(&totSmBufAllocCount);
197#endif /* CONFIG_CIFS_STATS2 */
198
199 return ret_buf;
200}
201
202void
203cifs_small_buf_release(void *buf_to_free)
204{
205
206 if (buf_to_free == NULL) {
207 cifs_dbg(FYI, "Null buffer passed to cifs_small_buf_release\n");
208 return;
209 }
210 mempool_free(buf_to_free, cifs_sm_req_poolp);
211
212 atomic_dec(&smBufAllocCount);
213 return;
214}
215
216void
217free_rsp_buf(int resp_buftype, void *rsp)
218{
219 if (resp_buftype == CIFS_SMALL_BUFFER)
220 cifs_small_buf_release(rsp);
221 else if (resp_buftype == CIFS_LARGE_BUFFER)
222 cifs_buf_release(rsp);
223}
224
225/* NB: MID can not be set if treeCon not passed in, in that
226 case it is responsbility of caller to set the mid */
227void
228header_assemble(struct smb_hdr *buffer, char smb_command /* command */ ,
229 const struct cifs_tcon *treeCon, int word_count
230 /* length of fixed section (word count) in two byte units */)
231{
232 char *temp = (char *) buffer;
233
234 memset(temp, 0, 256); /* bigger than MAX_CIFS_HDR_SIZE */
235
236 buffer->smb_buf_length = cpu_to_be32(
237 (2 * word_count) + sizeof(struct smb_hdr) -
238 4 /* RFC 1001 length field does not count */ +
239 2 /* for bcc field itself */) ;
240
241 buffer->Protocol[0] = 0xFF;
242 buffer->Protocol[1] = 'S';
243 buffer->Protocol[2] = 'M';
244 buffer->Protocol[3] = 'B';
245 buffer->Command = smb_command;
246 buffer->Flags = 0x00; /* case sensitive */
247 buffer->Flags2 = SMBFLG2_KNOWS_LONG_NAMES;
248 buffer->Pid = cpu_to_le16((__u16)current->tgid);
249 buffer->PidHigh = cpu_to_le16((__u16)(current->tgid >> 16));
250 if (treeCon) {
251 buffer->Tid = treeCon->tid;
252 if (treeCon->ses) {
253 if (treeCon->ses->capabilities & CAP_UNICODE)
254 buffer->Flags2 |= SMBFLG2_UNICODE;
255 if (treeCon->ses->capabilities & CAP_STATUS32)
256 buffer->Flags2 |= SMBFLG2_ERR_STATUS;
257
258 /* Uid is not converted */
259 buffer->Uid = treeCon->ses->Suid;
260 buffer->Mid = get_next_mid(treeCon->ses->server);
261 }
262 if (treeCon->Flags & SMB_SHARE_IS_IN_DFS)
263 buffer->Flags2 |= SMBFLG2_DFS;
264 if (treeCon->nocase)
265 buffer->Flags |= SMBFLG_CASELESS;
266 if ((treeCon->ses) && (treeCon->ses->server))
267 if (treeCon->ses->server->sign)
268 buffer->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
269 }
270
271/* endian conversion of flags is now done just before sending */
272 buffer->WordCount = (char) word_count;
273 return;
274}
275
276static int
277check_smb_hdr(struct smb_hdr *smb)
278{
279 /* does it have the right SMB "signature" ? */
280 if (*(__le32 *) smb->Protocol != cpu_to_le32(0x424d53ff)) {
281 cifs_dbg(VFS, "Bad protocol string signature header 0x%x\n",
282 *(unsigned int *)smb->Protocol);
283 return 1;
284 }
285
286 /* if it's a response then accept */
287 if (smb->Flags & SMBFLG_RESPONSE)
288 return 0;
289
290 /* only one valid case where server sends us request */
291 if (smb->Command == SMB_COM_LOCKING_ANDX)
292 return 0;
293
294 cifs_dbg(VFS, "Server sent request, not response. mid=%u\n",
295 get_mid(smb));
296 return 1;
297}
298
299int
300checkSMB(char *buf, unsigned int total_read, struct TCP_Server_Info *server)
301{
302 struct smb_hdr *smb = (struct smb_hdr *)buf;
303 __u32 rfclen = be32_to_cpu(smb->smb_buf_length);
304 __u32 clc_len; /* calculated length */
305 cifs_dbg(FYI, "checkSMB Length: 0x%x, smb_buf_length: 0x%x\n",
306 total_read, rfclen);
307
308 /* is this frame too small to even get to a BCC? */
309 if (total_read < 2 + sizeof(struct smb_hdr)) {
310 if ((total_read >= sizeof(struct smb_hdr) - 1)
311 && (smb->Status.CifsError != 0)) {
312 /* it's an error return */
313 smb->WordCount = 0;
314 /* some error cases do not return wct and bcc */
315 return 0;
316 } else if ((total_read == sizeof(struct smb_hdr) + 1) &&
317 (smb->WordCount == 0)) {
318 char *tmp = (char *)smb;
319 /* Need to work around a bug in two servers here */
320 /* First, check if the part of bcc they sent was zero */
321 if (tmp[sizeof(struct smb_hdr)] == 0) {
322 /* some servers return only half of bcc
323 * on simple responses (wct, bcc both zero)
324 * in particular have seen this on
325 * ulogoffX and FindClose. This leaves
326 * one byte of bcc potentially unitialized
327 */
328 /* zero rest of bcc */
329 tmp[sizeof(struct smb_hdr)+1] = 0;
330 return 0;
331 }
332 cifs_dbg(VFS, "rcvd invalid byte count (bcc)\n");
333 } else {
334 cifs_dbg(VFS, "Length less than smb header size\n");
335 }
336 return -EIO;
337 }
338
339 /* otherwise, there is enough to get to the BCC */
340 if (check_smb_hdr(smb))
341 return -EIO;
342 clc_len = smbCalcSize(smb);
343
344 if (4 + rfclen != total_read) {
345 cifs_dbg(VFS, "Length read does not match RFC1001 length %d\n",
346 rfclen);
347 return -EIO;
348 }
349
350 if (4 + rfclen != clc_len) {
351 __u16 mid = get_mid(smb);
352 /* check if bcc wrapped around for large read responses */
353 if ((rfclen > 64 * 1024) && (rfclen > clc_len)) {
354 /* check if lengths match mod 64K */
355 if (((4 + rfclen) & 0xFFFF) == (clc_len & 0xFFFF))
356 return 0; /* bcc wrapped */
357 }
358 cifs_dbg(FYI, "Calculated size %u vs length %u mismatch for mid=%u\n",
359 clc_len, 4 + rfclen, mid);
360
361 if (4 + rfclen < clc_len) {
362 cifs_dbg(VFS, "RFC1001 size %u smaller than SMB for mid=%u\n",
363 rfclen, mid);
364 return -EIO;
365 } else if (rfclen > clc_len + 512) {
366 /*
367 * Some servers (Windows XP in particular) send more
368 * data than the lengths in the SMB packet would
369 * indicate on certain calls (byte range locks and
370 * trans2 find first calls in particular). While the
371 * client can handle such a frame by ignoring the
372 * trailing data, we choose limit the amount of extra
373 * data to 512 bytes.
374 */
375 cifs_dbg(VFS, "RFC1001 size %u more than 512 bytes larger than SMB for mid=%u\n",
376 rfclen, mid);
377 return -EIO;
378 }
379 }
380 return 0;
381}
382
383bool
384is_valid_oplock_break(char *buffer, struct TCP_Server_Info *srv)
385{
386 struct smb_hdr *buf = (struct smb_hdr *)buffer;
387 struct smb_com_lock_req *pSMB = (struct smb_com_lock_req *)buf;
388 struct list_head *tmp, *tmp1, *tmp2;
389 struct cifs_ses *ses;
390 struct cifs_tcon *tcon;
391 struct cifsInodeInfo *pCifsInode;
392 struct cifsFileInfo *netfile;
393
394 cifs_dbg(FYI, "Checking for oplock break or dnotify response\n");
395 if ((pSMB->hdr.Command == SMB_COM_NT_TRANSACT) &&
396 (pSMB->hdr.Flags & SMBFLG_RESPONSE)) {
397 struct smb_com_transaction_change_notify_rsp *pSMBr =
398 (struct smb_com_transaction_change_notify_rsp *)buf;
399 struct file_notify_information *pnotify;
400 __u32 data_offset = 0;
401 if (get_bcc(buf) > sizeof(struct file_notify_information)) {
402 data_offset = le32_to_cpu(pSMBr->DataOffset);
403
404 pnotify = (struct file_notify_information *)
405 ((char *)&pSMBr->hdr.Protocol + data_offset);
406 cifs_dbg(FYI, "dnotify on %s Action: 0x%x\n",
407 pnotify->FileName, pnotify->Action);
408 /* cifs_dump_mem("Rcvd notify Data: ",buf,
409 sizeof(struct smb_hdr)+60); */
410 return true;
411 }
412 if (pSMBr->hdr.Status.CifsError) {
413 cifs_dbg(FYI, "notify err 0x%x\n",
414 pSMBr->hdr.Status.CifsError);
415 return true;
416 }
417 return false;
418 }
419 if (pSMB->hdr.Command != SMB_COM_LOCKING_ANDX)
420 return false;
421 if (pSMB->hdr.Flags & SMBFLG_RESPONSE) {
422 /* no sense logging error on invalid handle on oplock
423 break - harmless race between close request and oplock
424 break response is expected from time to time writing out
425 large dirty files cached on the client */
426 if ((NT_STATUS_INVALID_HANDLE) ==
427 le32_to_cpu(pSMB->hdr.Status.CifsError)) {
428 cifs_dbg(FYI, "invalid handle on oplock break\n");
429 return true;
430 } else if (ERRbadfid ==
431 le16_to_cpu(pSMB->hdr.Status.DosError.Error)) {
432 return true;
433 } else {
434 return false; /* on valid oplock brk we get "request" */
435 }
436 }
437 if (pSMB->hdr.WordCount != 8)
438 return false;
439
440 cifs_dbg(FYI, "oplock type 0x%x level 0x%x\n",
441 pSMB->LockType, pSMB->OplockLevel);
442 if (!(pSMB->LockType & LOCKING_ANDX_OPLOCK_RELEASE))
443 return false;
444
445 /* look up tcon based on tid & uid */
446 spin_lock(&cifs_tcp_ses_lock);
447 list_for_each(tmp, &srv->smb_ses_list) {
448 ses = list_entry(tmp, struct cifs_ses, smb_ses_list);
449 list_for_each(tmp1, &ses->tcon_list) {
450 tcon = list_entry(tmp1, struct cifs_tcon, tcon_list);
451 if (tcon->tid != buf->Tid)
452 continue;
453
454 cifs_stats_inc(&tcon->stats.cifs_stats.num_oplock_brks);
455 spin_lock(&tcon->open_file_lock);
456 list_for_each(tmp2, &tcon->openFileList) {
457 netfile = list_entry(tmp2, struct cifsFileInfo,
458 tlist);
459 if (pSMB->Fid != netfile->fid.netfid)
460 continue;
461
462 cifs_dbg(FYI, "file id match, oplock break\n");
463 pCifsInode = CIFS_I(d_inode(netfile->dentry));
464
465 set_bit(CIFS_INODE_PENDING_OPLOCK_BREAK,
466 &pCifsInode->flags);
467
468 /*
469 * Set flag if the server downgrades the oplock
470 * to L2 else clear.
471 */
472 if (pSMB->OplockLevel)
473 set_bit(
474 CIFS_INODE_DOWNGRADE_OPLOCK_TO_L2,
475 &pCifsInode->flags);
476 else
477 clear_bit(
478 CIFS_INODE_DOWNGRADE_OPLOCK_TO_L2,
479 &pCifsInode->flags);
480
481 queue_work(cifsoplockd_wq,
482 &netfile->oplock_break);
483 netfile->oplock_break_cancelled = false;
484
485 spin_unlock(&tcon->open_file_lock);
486 spin_unlock(&cifs_tcp_ses_lock);
487 return true;
488 }
489 spin_unlock(&tcon->open_file_lock);
490 spin_unlock(&cifs_tcp_ses_lock);
491 cifs_dbg(FYI, "No matching file for oplock break\n");
492 return true;
493 }
494 }
495 spin_unlock(&cifs_tcp_ses_lock);
496 cifs_dbg(FYI, "Can not process oplock break for non-existent connection\n");
497 return true;
498}
499
500void
501dump_smb(void *buf, int smb_buf_length)
502{
503 if (traceSMB == 0)
504 return;
505
506 print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_NONE, 8, 2, buf,
507 smb_buf_length, true);
508}
509
510void
511cifs_autodisable_serverino(struct cifs_sb_info *cifs_sb)
512{
513 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) {
514 cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM;
515 cifs_dbg(VFS, "Autodisabling the use of server inode numbers on %s. This server doesn't seem to support them properly. Hardlinks will not be recognized on this mount. Consider mounting with the \"noserverino\" option to silence this message.\n",
516 cifs_sb_master_tcon(cifs_sb)->treeName);
517 }
518}
519
520void cifs_set_oplock_level(struct cifsInodeInfo *cinode, __u32 oplock)
521{
522 oplock &= 0xF;
523
524 if (oplock == OPLOCK_EXCLUSIVE) {
525 cinode->oplock = CIFS_CACHE_WRITE_FLG | CIFS_CACHE_READ_FLG;
526 cifs_dbg(FYI, "Exclusive Oplock granted on inode %p\n",
527 &cinode->vfs_inode);
528 } else if (oplock == OPLOCK_READ) {
529 cinode->oplock = CIFS_CACHE_READ_FLG;
530 cifs_dbg(FYI, "Level II Oplock granted on inode %p\n",
531 &cinode->vfs_inode);
532 } else
533 cinode->oplock = 0;
534}
535
536/*
537 * We wait for oplock breaks to be processed before we attempt to perform
538 * writes.
539 */
540int cifs_get_writer(struct cifsInodeInfo *cinode)
541{
542 int rc;
543
544start:
545 rc = wait_on_bit(&cinode->flags, CIFS_INODE_PENDING_OPLOCK_BREAK,
546 TASK_KILLABLE);
547 if (rc)
548 return rc;
549
550 spin_lock(&cinode->writers_lock);
551 if (!cinode->writers)
552 set_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags);
553 cinode->writers++;
554 /* Check to see if we have started servicing an oplock break */
555 if (test_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, &cinode->flags)) {
556 cinode->writers--;
557 if (cinode->writers == 0) {
558 clear_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags);
559 wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_WRITERS);
560 }
561 spin_unlock(&cinode->writers_lock);
562 goto start;
563 }
564 spin_unlock(&cinode->writers_lock);
565 return 0;
566}
567
568void cifs_put_writer(struct cifsInodeInfo *cinode)
569{
570 spin_lock(&cinode->writers_lock);
571 cinode->writers--;
572 if (cinode->writers == 0) {
573 clear_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags);
574 wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_WRITERS);
575 }
576 spin_unlock(&cinode->writers_lock);
577}
578
579void cifs_done_oplock_break(struct cifsInodeInfo *cinode)
580{
581 clear_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, &cinode->flags);
582 wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_OPLOCK_BREAK);
583}
584
585bool
586backup_cred(struct cifs_sb_info *cifs_sb)
587{
588 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPUID) {
589 if (uid_eq(cifs_sb->mnt_backupuid, current_fsuid()))
590 return true;
591 }
592 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPGID) {
593 if (in_group_p(cifs_sb->mnt_backupgid))
594 return true;
595 }
596
597 return false;
598}
599
600void
601cifs_del_pending_open(struct cifs_pending_open *open)
602{
603 spin_lock(&tlink_tcon(open->tlink)->open_file_lock);
604 list_del(&open->olist);
605 spin_unlock(&tlink_tcon(open->tlink)->open_file_lock);
606}
607
608void
609cifs_add_pending_open_locked(struct cifs_fid *fid, struct tcon_link *tlink,
610 struct cifs_pending_open *open)
611{
612 memcpy(open->lease_key, fid->lease_key, SMB2_LEASE_KEY_SIZE);
613 open->oplock = CIFS_OPLOCK_NO_CHANGE;
614 open->tlink = tlink;
615 fid->pending_open = open;
616 list_add_tail(&open->olist, &tlink_tcon(tlink)->pending_opens);
617}
618
619void
620cifs_add_pending_open(struct cifs_fid *fid, struct tcon_link *tlink,
621 struct cifs_pending_open *open)
622{
623 spin_lock(&tlink_tcon(tlink)->open_file_lock);
624 cifs_add_pending_open_locked(fid, tlink, open);
625 spin_unlock(&tlink_tcon(open->tlink)->open_file_lock);
626}
627
628/* parses DFS refferal V3 structure
629 * caller is responsible for freeing target_nodes
630 * returns:
631 * - on success - 0
632 * - on failure - errno
633 */
634int
635parse_dfs_referrals(struct get_dfs_referral_rsp *rsp, u32 rsp_size,
636 unsigned int *num_of_nodes,
637 struct dfs_info3_param **target_nodes,
638 const struct nls_table *nls_codepage, int remap,
639 const char *searchName, bool is_unicode)
640{
641 int i, rc = 0;
642 char *data_end;
643 struct dfs_referral_level_3 *ref;
644
645 *num_of_nodes = le16_to_cpu(rsp->NumberOfReferrals);
646
647 if (*num_of_nodes < 1) {
648 cifs_dbg(VFS, "num_referrals: must be at least > 0, but we get num_referrals = %d\n",
649 *num_of_nodes);
650 rc = -EINVAL;
651 goto parse_DFS_referrals_exit;
652 }
653
654 ref = (struct dfs_referral_level_3 *) &(rsp->referrals);
655 if (ref->VersionNumber != cpu_to_le16(3)) {
656 cifs_dbg(VFS, "Referrals of V%d version are not supported, should be V3\n",
657 le16_to_cpu(ref->VersionNumber));
658 rc = -EINVAL;
659 goto parse_DFS_referrals_exit;
660 }
661
662 /* get the upper boundary of the resp buffer */
663 data_end = (char *)rsp + rsp_size;
664
665 cifs_dbg(FYI, "num_referrals: %d dfs flags: 0x%x ...\n",
666 *num_of_nodes, le32_to_cpu(rsp->DFSFlags));
667
668 *target_nodes = kcalloc(*num_of_nodes, sizeof(struct dfs_info3_param),
669 GFP_KERNEL);
670 if (*target_nodes == NULL) {
671 rc = -ENOMEM;
672 goto parse_DFS_referrals_exit;
673 }
674
675 /* collect necessary data from referrals */
676 for (i = 0; i < *num_of_nodes; i++) {
677 char *temp;
678 int max_len;
679 struct dfs_info3_param *node = (*target_nodes)+i;
680
681 node->flags = le32_to_cpu(rsp->DFSFlags);
682 if (is_unicode) {
683 __le16 *tmp = kmalloc(strlen(searchName)*2 + 2,
684 GFP_KERNEL);
685 if (tmp == NULL) {
686 rc = -ENOMEM;
687 goto parse_DFS_referrals_exit;
688 }
689 cifsConvertToUTF16((__le16 *) tmp, searchName,
690 PATH_MAX, nls_codepage, remap);
691 node->path_consumed = cifs_utf16_bytes(tmp,
692 le16_to_cpu(rsp->PathConsumed),
693 nls_codepage);
694 kfree(tmp);
695 } else
696 node->path_consumed = le16_to_cpu(rsp->PathConsumed);
697
698 node->server_type = le16_to_cpu(ref->ServerType);
699 node->ref_flag = le16_to_cpu(ref->ReferralEntryFlags);
700
701 /* copy DfsPath */
702 temp = (char *)ref + le16_to_cpu(ref->DfsPathOffset);
703 max_len = data_end - temp;
704 node->path_name = cifs_strndup_from_utf16(temp, max_len,
705 is_unicode, nls_codepage);
706 if (!node->path_name) {
707 rc = -ENOMEM;
708 goto parse_DFS_referrals_exit;
709 }
710
711 /* copy link target UNC */
712 temp = (char *)ref + le16_to_cpu(ref->NetworkAddressOffset);
713 max_len = data_end - temp;
714 node->node_name = cifs_strndup_from_utf16(temp, max_len,
715 is_unicode, nls_codepage);
716 if (!node->node_name) {
717 rc = -ENOMEM;
718 goto parse_DFS_referrals_exit;
719 }
720
721 ref++;
722 }
723
724parse_DFS_referrals_exit:
725 if (rc) {
726 free_dfs_info_array(*target_nodes, *num_of_nodes);
727 *target_nodes = NULL;
728 *num_of_nodes = 0;
729 }
730 return rc;
731}
732
733struct cifs_aio_ctx *
734cifs_aio_ctx_alloc(void)
735{
736 struct cifs_aio_ctx *ctx;
737
738 ctx = kzalloc(sizeof(struct cifs_aio_ctx), GFP_KERNEL);
739 if (!ctx)
740 return NULL;
741
742 INIT_LIST_HEAD(&ctx->list);
743 mutex_init(&ctx->aio_mutex);
744 init_completion(&ctx->done);
745 kref_init(&ctx->refcount);
746 return ctx;
747}
748
749void
750cifs_aio_ctx_release(struct kref *refcount)
751{
752 struct cifs_aio_ctx *ctx = container_of(refcount,
753 struct cifs_aio_ctx, refcount);
754
755 cifsFileInfo_put(ctx->cfile);
756 kvfree(ctx->bv);
757 kfree(ctx);
758}
759
760#define CIFS_AIO_KMALLOC_LIMIT (1024 * 1024)
761
762int
763setup_aio_ctx_iter(struct cifs_aio_ctx *ctx, struct iov_iter *iter, int rw)
764{
765 ssize_t rc;
766 unsigned int cur_npages;
767 unsigned int npages = 0;
768 unsigned int i;
769 size_t len;
770 size_t count = iov_iter_count(iter);
771 unsigned int saved_len;
772 size_t start;
773 unsigned int max_pages = iov_iter_npages(iter, INT_MAX);
774 struct page **pages = NULL;
775 struct bio_vec *bv = NULL;
776
777 if (iter->type & ITER_KVEC) {
778 memcpy(&ctx->iter, iter, sizeof(struct iov_iter));
779 ctx->len = count;
780 iov_iter_advance(iter, count);
781 return 0;
782 }
783
784 if (max_pages * sizeof(struct bio_vec) <= CIFS_AIO_KMALLOC_LIMIT)
785 bv = kmalloc_array(max_pages, sizeof(struct bio_vec),
786 GFP_KERNEL);
787
788 if (!bv) {
789 bv = vmalloc(max_pages * sizeof(struct bio_vec));
790 if (!bv)
791 return -ENOMEM;
792 }
793
794 if (max_pages * sizeof(struct page *) <= CIFS_AIO_KMALLOC_LIMIT)
795 pages = kmalloc_array(max_pages, sizeof(struct page *),
796 GFP_KERNEL);
797
798 if (!pages) {
799 pages = vmalloc(max_pages * sizeof(struct page *));
800 if (!pages) {
801 kvfree(bv);
802 return -ENOMEM;
803 }
804 }
805
806 saved_len = count;
807
808 while (count && npages < max_pages) {
809 rc = iov_iter_get_pages(iter, pages, count, max_pages, &start);
810 if (rc < 0) {
811 cifs_dbg(VFS, "couldn't get user pages (rc=%zd)\n", rc);
812 break;
813 }
814
815 if (rc > count) {
816 cifs_dbg(VFS, "get pages rc=%zd more than %zu\n", rc,
817 count);
818 break;
819 }
820
821 iov_iter_advance(iter, rc);
822 count -= rc;
823 rc += start;
824 cur_npages = DIV_ROUND_UP(rc, PAGE_SIZE);
825
826 if (npages + cur_npages > max_pages) {
827 cifs_dbg(VFS, "out of vec array capacity (%u vs %u)\n",
828 npages + cur_npages, max_pages);
829 break;
830 }
831
832 for (i = 0; i < cur_npages; i++) {
833 len = rc > PAGE_SIZE ? PAGE_SIZE : rc;
834 bv[npages + i].bv_page = pages[i];
835 bv[npages + i].bv_offset = start;
836 bv[npages + i].bv_len = len - start;
837 rc -= len;
838 start = 0;
839 }
840
841 npages += cur_npages;
842 }
843
844 kvfree(pages);
845 ctx->bv = bv;
846 ctx->len = saved_len - count;
847 ctx->npages = npages;
848 iov_iter_bvec(&ctx->iter, ITER_BVEC | rw, ctx->bv, npages, ctx->len);
849 return 0;
850}
851
852/**
853 * cifs_alloc_hash - allocate hash and hash context together
854 *
855 * The caller has to make sure @sdesc is initialized to either NULL or
856 * a valid context. Both can be freed via cifs_free_hash().
857 */
858int
859cifs_alloc_hash(const char *name,
860 struct crypto_shash **shash, struct sdesc **sdesc)
861{
862 int rc = 0;
863 size_t size;
864
865 if (*sdesc != NULL)
866 return 0;
867
868 *shash = crypto_alloc_shash(name, 0, 0);
869 if (IS_ERR(*shash)) {
870 cifs_dbg(VFS, "could not allocate crypto %s\n", name);
871 rc = PTR_ERR(*shash);
872 *shash = NULL;
873 *sdesc = NULL;
874 return rc;
875 }
876
877 size = sizeof(struct shash_desc) + crypto_shash_descsize(*shash);
878 *sdesc = kmalloc(size, GFP_KERNEL);
879 if (*sdesc == NULL) {
880 cifs_dbg(VFS, "no memory left to allocate crypto %s\n", name);
881 crypto_free_shash(*shash);
882 *shash = NULL;
883 return -ENOMEM;
884 }
885
886 (*sdesc)->shash.tfm = *shash;
887 (*sdesc)->shash.flags = 0x0;
888 return 0;
889}
890
891/**
892 * cifs_free_hash - free hash and hash context together
893 *
894 * Freeing a NULL hash or context is safe.
895 */
896void
897cifs_free_hash(struct crypto_shash **shash, struct sdesc **sdesc)
898{
899 kfree(*sdesc);
900 *sdesc = NULL;
901 if (*shash)
902 crypto_free_shash(*shash);
903 *shash = NULL;
904}