1 // SPDX-License-Identifier: LGPL-2.1
2 /*
3 *
4 * Copyright (C) International Business Machines Corp., 2002,2011
5 * Author(s): Steve French (sfrench@us.ibm.com)
6 *
7 */
8 #include <linux/fs.h>
9 #include <linux/net.h>
10 #include <linux/string.h>
11 #include <linux/sched/mm.h>
12 #include <linux/sched/signal.h>
13 #include <linux/list.h>
14 #include <linux/wait.h>
15 #include <linux/slab.h>
16 #include <linux/pagemap.h>
17 #include <linux/ctype.h>
18 #include <linux/utsname.h>
19 #include <linux/mempool.h>
20 #include <linux/delay.h>
21 #include <linux/completion.h>
22 #include <linux/kthread.h>
23 #include <linux/pagevec.h>
24 #include <linux/freezer.h>
25 #include <linux/namei.h>
26 #include <linux/uuid.h>
27 #include <linux/uaccess.h>
28 #include <asm/processor.h>
29 #include <linux/inet.h>
30 #include <linux/module.h>
31 #include <keys/user-type.h>
32 #include <net/ipv6.h>
33 #include <linux/parser.h>
34 #include <linux/bvec.h>
35 #include "cifspdu.h"
36 #include "cifsglob.h"
37 #include "cifsproto.h"
38 #include "cifs_unicode.h"
39 #include "cifs_debug.h"
40 #include "cifs_fs_sb.h"
41 #include "ntlmssp.h"
42 #include "nterr.h"
43 #include "rfc1002pdu.h"
44 #include "fscache.h"
45 #include "smb2proto.h"
46 #include "smbdirect.h"
47 #include "dns_resolve.h"
48 #ifdef CONFIG_CIFS_DFS_UPCALL
49 #include "dfs.h"
50 #include "dfs_cache.h"
51 #endif
52 #include "fs_context.h"
53 #include "cifs_swn.h"
54
55 /* FIXME: should these be tunable? */
56 #define TLINK_ERROR_EXPIRE (1 * HZ)
57 #define TLINK_IDLE_EXPIRE (600 * HZ)
58
59 /* Drop the connection to not overload the server */
60 #define MAX_STATUS_IO_TIMEOUT 5
61
62 static int ip_connect(struct TCP_Server_Info *server);
63 static int generic_ip_connect(struct TCP_Server_Info *server);
64 static void tlink_rb_insert(struct rb_root *root, struct tcon_link *new_tlink);
65 static void cifs_prune_tlinks(struct work_struct *work);
66
67 /*
68 * Resolve hostname and set ip addr in tcp ses. Useful for hostnames that may
69 * get their ip addresses changed at some point.
70 *
71 * This should be called with server->srv_mutex held.
72 */
reconn_set_ipaddr_from_hostname(struct TCP_Server_Info * server)73 static int reconn_set_ipaddr_from_hostname(struct TCP_Server_Info *server)
74 {
75 int rc;
76 int len;
77 char *unc;
78 struct sockaddr_storage ss;
79
80 if (!server->hostname)
81 return -EINVAL;
82
83 /* if server hostname isn't populated, there's nothing to do here */
84 if (server->hostname[0] == '\0')
85 return 0;
86
87 len = strlen(server->hostname) + 3;
88
89 unc = kmalloc(len, GFP_KERNEL);
90 if (!unc) {
91 cifs_dbg(FYI, "%s: failed to create UNC path\n", __func__);
92 return -ENOMEM;
93 }
94 scnprintf(unc, len, "\\\\%s", server->hostname);
95
96 spin_lock(&server->srv_lock);
97 ss = server->dstaddr;
98 spin_unlock(&server->srv_lock);
99
100 rc = dns_resolve_server_name_to_ip(unc, (struct sockaddr *)&ss, NULL);
101 kfree(unc);
102
103 if (rc < 0) {
104 cifs_dbg(FYI, "%s: failed to resolve server part of %s to IP: %d\n",
105 __func__, server->hostname, rc);
106 } else {
107 spin_lock(&server->srv_lock);
108 memcpy(&server->dstaddr, &ss, sizeof(server->dstaddr));
109 spin_unlock(&server->srv_lock);
110 rc = 0;
111 }
112
113 return rc;
114 }
115
smb2_query_server_interfaces(struct work_struct * work)116 static void smb2_query_server_interfaces(struct work_struct *work)
117 {
118 int rc;
119 int xid;
120 struct cifs_tcon *tcon = container_of(work,
121 struct cifs_tcon,
122 query_interfaces.work);
123 struct TCP_Server_Info *server = tcon->ses->server;
124
125 /*
126 * query server network interfaces, in case they change
127 */
128 if (!server->ops->query_server_interfaces)
129 return;
130
131 xid = get_xid();
132 rc = server->ops->query_server_interfaces(xid, tcon, false);
133 free_xid(xid);
134
135 if (rc) {
136 if (rc == -EOPNOTSUPP)
137 return;
138
139 cifs_dbg(FYI, "%s: failed to query server interfaces: %d\n",
140 __func__, rc);
141 }
142
143 queue_delayed_work(cifsiod_wq, &tcon->query_interfaces,
144 (SMB_INTERFACE_POLL_INTERVAL * HZ));
145 }
146
147 /*
148 * Update the tcpStatus for the server.
149 * This is used to signal the cifsd thread to call cifs_reconnect
150 * ONLY cifsd thread should call cifs_reconnect. For any other
151 * thread, use this function
152 *
153 * @server: the tcp ses for which reconnect is needed
154 * @all_channels: if this needs to be done for all channels
155 */
156 void
cifs_signal_cifsd_for_reconnect(struct TCP_Server_Info * server,bool all_channels)157 cifs_signal_cifsd_for_reconnect(struct TCP_Server_Info *server,
158 bool all_channels)
159 {
160 struct TCP_Server_Info *pserver;
161 struct cifs_ses *ses;
162 int i;
163
164 /* If server is a channel, select the primary channel */
165 pserver = SERVER_IS_CHAN(server) ? server->primary_server : server;
166
167 /* if we need to signal just this channel */
168 if (!all_channels) {
169 spin_lock(&server->srv_lock);
170 if (server->tcpStatus != CifsExiting)
171 server->tcpStatus = CifsNeedReconnect;
172 spin_unlock(&server->srv_lock);
173 return;
174 }
175
176 spin_lock(&cifs_tcp_ses_lock);
177 list_for_each_entry(ses, &pserver->smb_ses_list, smb_ses_list) {
178 if (cifs_ses_exiting(ses))
179 continue;
180 spin_lock(&ses->chan_lock);
181 for (i = 0; i < ses->chan_count; i++) {
182 if (!ses->chans[i].server)
183 continue;
184
185 spin_lock(&ses->chans[i].server->srv_lock);
186 if (ses->chans[i].server->tcpStatus != CifsExiting)
187 ses->chans[i].server->tcpStatus = CifsNeedReconnect;
188 spin_unlock(&ses->chans[i].server->srv_lock);
189 }
190 spin_unlock(&ses->chan_lock);
191 }
192 spin_unlock(&cifs_tcp_ses_lock);
193 }
194
195 /*
196 * Mark all sessions and tcons for reconnect.
197 * IMPORTANT: make sure that this gets called only from
198 * cifsd thread. For any other thread, use
199 * cifs_signal_cifsd_for_reconnect
200 *
201 * @server: the tcp ses for which reconnect is needed
202 * @server needs to be previously set to CifsNeedReconnect.
203 * @mark_smb_session: whether even sessions need to be marked
204 */
205 void
cifs_mark_tcp_ses_conns_for_reconnect(struct TCP_Server_Info * server,bool mark_smb_session)206 cifs_mark_tcp_ses_conns_for_reconnect(struct TCP_Server_Info *server,
207 bool mark_smb_session)
208 {
209 struct TCP_Server_Info *pserver;
210 struct cifs_ses *ses, *nses;
211 struct cifs_tcon *tcon;
212
213 /*
214 * before reconnecting the tcp session, mark the smb session (uid) and the tid bad so they
215 * are not used until reconnected.
216 */
217 cifs_dbg(FYI, "%s: marking necessary sessions and tcons for reconnect\n", __func__);
218
219 /* If server is a channel, select the primary channel */
220 pserver = SERVER_IS_CHAN(server) ? server->primary_server : server;
221
222 /*
223 * if the server has been marked for termination, there is a
224 * chance that the remaining channels all need reconnect. To be
225 * on the safer side, mark the session and trees for reconnect
226 * for this scenario. This might cause a few redundant session
227 * setup and tree connect requests, but it is better than not doing
228 * a tree connect when needed, and all following requests failing
229 */
230 if (server->terminate) {
231 mark_smb_session = true;
232 server = pserver;
233 }
234
235 spin_lock(&cifs_tcp_ses_lock);
236 list_for_each_entry_safe(ses, nses, &pserver->smb_ses_list, smb_ses_list) {
237 spin_lock(&ses->ses_lock);
238 if (ses->ses_status == SES_EXITING) {
239 spin_unlock(&ses->ses_lock);
240 continue;
241 }
242 spin_unlock(&ses->ses_lock);
243
244 spin_lock(&ses->chan_lock);
245 if (cifs_ses_get_chan_index(ses, server) ==
246 CIFS_INVAL_CHAN_INDEX) {
247 spin_unlock(&ses->chan_lock);
248 continue;
249 }
250
251 if (!cifs_chan_is_iface_active(ses, server)) {
252 spin_unlock(&ses->chan_lock);
253 cifs_chan_update_iface(ses, server);
254 spin_lock(&ses->chan_lock);
255 }
256
257 if (!mark_smb_session && cifs_chan_needs_reconnect(ses, server)) {
258 spin_unlock(&ses->chan_lock);
259 continue;
260 }
261
262 if (mark_smb_session)
263 CIFS_SET_ALL_CHANS_NEED_RECONNECT(ses);
264 else
265 cifs_chan_set_need_reconnect(ses, server);
266
267 cifs_dbg(FYI, "%s: channel connect bitmap: 0x%lx\n",
268 __func__, ses->chans_need_reconnect);
269
270 /* If all channels need reconnect, then tcon needs reconnect */
271 if (!mark_smb_session && !CIFS_ALL_CHANS_NEED_RECONNECT(ses)) {
272 spin_unlock(&ses->chan_lock);
273 continue;
274 }
275 spin_unlock(&ses->chan_lock);
276
277 spin_lock(&ses->ses_lock);
278 ses->ses_status = SES_NEED_RECON;
279 spin_unlock(&ses->ses_lock);
280
281 list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
282 tcon->need_reconnect = true;
283 spin_lock(&tcon->tc_lock);
284 tcon->status = TID_NEED_RECON;
285 spin_unlock(&tcon->tc_lock);
286
287 cancel_delayed_work(&tcon->query_interfaces);
288 }
289 if (ses->tcon_ipc) {
290 ses->tcon_ipc->need_reconnect = true;
291 spin_lock(&ses->tcon_ipc->tc_lock);
292 ses->tcon_ipc->status = TID_NEED_RECON;
293 spin_unlock(&ses->tcon_ipc->tc_lock);
294 }
295 }
296 spin_unlock(&cifs_tcp_ses_lock);
297 }
298
299 static void
cifs_abort_connection(struct TCP_Server_Info * server)300 cifs_abort_connection(struct TCP_Server_Info *server)
301 {
302 struct mid_q_entry *mid, *nmid;
303 struct list_head retry_list;
304
305 server->maxBuf = 0;
306 server->max_read = 0;
307
308 /* do not want to be sending data on a socket we are freeing */
309 cifs_dbg(FYI, "%s: tearing down socket\n", __func__);
310 cifs_server_lock(server);
311 if (server->ssocket) {
312 cifs_dbg(FYI, "State: 0x%x Flags: 0x%lx\n", server->ssocket->state,
313 server->ssocket->flags);
314 kernel_sock_shutdown(server->ssocket, SHUT_WR);
315 cifs_dbg(FYI, "Post shutdown state: 0x%x Flags: 0x%lx\n", server->ssocket->state,
316 server->ssocket->flags);
317 sock_release(server->ssocket);
318 server->ssocket = NULL;
319 }
320 server->sequence_number = 0;
321 server->session_estab = false;
322 kfree_sensitive(server->session_key.response);
323 server->session_key.response = NULL;
324 server->session_key.len = 0;
325 server->lstrp = jiffies;
326
327 /* mark submitted MIDs for retry and issue callback */
328 INIT_LIST_HEAD(&retry_list);
329 cifs_dbg(FYI, "%s: moving mids to private list\n", __func__);
330 spin_lock(&server->mid_lock);
331 list_for_each_entry_safe(mid, nmid, &server->pending_mid_q, qhead) {
332 kref_get(&mid->refcount);
333 if (mid->mid_state == MID_REQUEST_SUBMITTED)
334 mid->mid_state = MID_RETRY_NEEDED;
335 list_move(&mid->qhead, &retry_list);
336 mid->mid_flags |= MID_DELETED;
337 }
338 spin_unlock(&server->mid_lock);
339 cifs_server_unlock(server);
340
341 cifs_dbg(FYI, "%s: issuing mid callbacks\n", __func__);
342 list_for_each_entry_safe(mid, nmid, &retry_list, qhead) {
343 list_del_init(&mid->qhead);
344 mid->callback(mid);
345 release_mid(mid);
346 }
347
348 if (cifs_rdma_enabled(server)) {
349 cifs_server_lock(server);
350 smbd_destroy(server);
351 cifs_server_unlock(server);
352 }
353 }
354
cifs_tcp_ses_needs_reconnect(struct TCP_Server_Info * server,int num_targets)355 static bool cifs_tcp_ses_needs_reconnect(struct TCP_Server_Info *server, int num_targets)
356 {
357 spin_lock(&server->srv_lock);
358 server->nr_targets = num_targets;
359 if (server->tcpStatus == CifsExiting) {
360 /* the demux thread will exit normally next time through the loop */
361 spin_unlock(&server->srv_lock);
362 wake_up(&server->response_q);
363 return false;
364 }
365
366 cifs_dbg(FYI, "Mark tcp session as need reconnect\n");
367 trace_smb3_reconnect(server->CurrentMid, server->conn_id,
368 server->hostname);
369 server->tcpStatus = CifsNeedReconnect;
370
371 spin_unlock(&server->srv_lock);
372 return true;
373 }
374
375 /*
376 * cifs tcp session reconnection
377 *
378 * mark tcp session as reconnecting so temporarily locked
379 * mark all smb sessions as reconnecting for tcp session
380 * reconnect tcp session
381 * wake up waiters on reconnection? - (not needed currently)
382 *
383 * if mark_smb_session is passed as true, unconditionally mark
384 * the smb session (and tcon) for reconnect as well. This value
385 * doesn't really matter for non-multichannel scenario.
386 *
387 */
__cifs_reconnect(struct TCP_Server_Info * server,bool mark_smb_session)388 static int __cifs_reconnect(struct TCP_Server_Info *server,
389 bool mark_smb_session)
390 {
391 int rc = 0;
392
393 if (!cifs_tcp_ses_needs_reconnect(server, 1))
394 return 0;
395
396 cifs_mark_tcp_ses_conns_for_reconnect(server, mark_smb_session);
397
398 cifs_abort_connection(server);
399
400 do {
401 try_to_freeze();
402 cifs_server_lock(server);
403
404 if (!cifs_swn_set_server_dstaddr(server)) {
405 /* resolve the hostname again to make sure that IP address is up-to-date */
406 rc = reconn_set_ipaddr_from_hostname(server);
407 cifs_dbg(FYI, "%s: reconn_set_ipaddr_from_hostname: rc=%d\n", __func__, rc);
408 }
409
410 if (cifs_rdma_enabled(server))
411 rc = smbd_reconnect(server);
412 else
413 rc = generic_ip_connect(server);
414 if (rc) {
415 cifs_server_unlock(server);
416 cifs_dbg(FYI, "%s: reconnect error %d\n", __func__, rc);
417 msleep(3000);
418 } else {
419 atomic_inc(&tcpSesReconnectCount);
420 set_credits(server, 1);
421 spin_lock(&server->srv_lock);
422 if (server->tcpStatus != CifsExiting)
423 server->tcpStatus = CifsNeedNegotiate;
424 spin_unlock(&server->srv_lock);
425 cifs_swn_reset_server_dstaddr(server);
426 cifs_server_unlock(server);
427 mod_delayed_work(cifsiod_wq, &server->reconnect, 0);
428 }
429 } while (server->tcpStatus == CifsNeedReconnect);
430
431 spin_lock(&server->srv_lock);
432 if (server->tcpStatus == CifsNeedNegotiate)
433 mod_delayed_work(cifsiod_wq, &server->echo, 0);
434 spin_unlock(&server->srv_lock);
435
436 wake_up(&server->response_q);
437 return rc;
438 }
439
440 #ifdef CONFIG_CIFS_DFS_UPCALL
__reconnect_target_unlocked(struct TCP_Server_Info * server,const char * target)441 static int __reconnect_target_unlocked(struct TCP_Server_Info *server, const char *target)
442 {
443 int rc;
444 char *hostname;
445
446 if (!cifs_swn_set_server_dstaddr(server)) {
447 if (server->hostname != target) {
448 hostname = extract_hostname(target);
449 if (!IS_ERR(hostname)) {
450 spin_lock(&server->srv_lock);
451 kfree(server->hostname);
452 server->hostname = hostname;
453 spin_unlock(&server->srv_lock);
454 } else {
455 cifs_dbg(FYI, "%s: couldn't extract hostname or address from dfs target: %ld\n",
456 __func__, PTR_ERR(hostname));
457 cifs_dbg(FYI, "%s: default to last target server: %s\n", __func__,
458 server->hostname);
459 }
460 }
461 /* resolve the hostname again to make sure that IP address is up-to-date. */
462 rc = reconn_set_ipaddr_from_hostname(server);
463 cifs_dbg(FYI, "%s: reconn_set_ipaddr_from_hostname: rc=%d\n", __func__, rc);
464 }
465 /* Reconnect the socket */
466 if (cifs_rdma_enabled(server))
467 rc = smbd_reconnect(server);
468 else
469 rc = generic_ip_connect(server);
470
471 return rc;
472 }
473
reconnect_target_unlocked(struct TCP_Server_Info * server,struct dfs_cache_tgt_list * tl,struct dfs_cache_tgt_iterator ** target_hint)474 static int reconnect_target_unlocked(struct TCP_Server_Info *server, struct dfs_cache_tgt_list *tl,
475 struct dfs_cache_tgt_iterator **target_hint)
476 {
477 int rc;
478 struct dfs_cache_tgt_iterator *tit;
479
480 *target_hint = NULL;
481
482 /* If dfs target list is empty, then reconnect to last server */
483 tit = dfs_cache_get_tgt_iterator(tl);
484 if (!tit)
485 return __reconnect_target_unlocked(server, server->hostname);
486
487 /* Otherwise, try every dfs target in @tl */
488 for (; tit; tit = dfs_cache_get_next_tgt(tl, tit)) {
489 rc = __reconnect_target_unlocked(server, dfs_cache_get_tgt_name(tit));
490 if (!rc) {
491 *target_hint = tit;
492 break;
493 }
494 }
495 return rc;
496 }
497
reconnect_dfs_server(struct TCP_Server_Info * server)498 static int reconnect_dfs_server(struct TCP_Server_Info *server)
499 {
500 struct dfs_cache_tgt_iterator *target_hint = NULL;
501
502 DFS_CACHE_TGT_LIST(tl);
503 int num_targets = 0;
504 int rc = 0;
505
506 /*
507 * Determine the number of dfs targets the referral path in @cifs_sb resolves to.
508 *
509 * smb2_reconnect() needs to know how long it should wait based upon the number of dfs
510 * targets (server->nr_targets). It's also possible that the cached referral was cleared
511 * through /proc/fs/cifs/dfscache or the target list is empty due to server settings after
512 * refreshing the referral, so, in this case, default it to 1.
513 */
514 mutex_lock(&server->refpath_lock);
515 if (!dfs_cache_noreq_find(server->leaf_fullpath + 1, NULL, &tl))
516 num_targets = dfs_cache_get_nr_tgts(&tl);
517 mutex_unlock(&server->refpath_lock);
518 if (!num_targets)
519 num_targets = 1;
520
521 if (!cifs_tcp_ses_needs_reconnect(server, num_targets))
522 return 0;
523
524 /*
525 * Unconditionally mark all sessions & tcons for reconnect as we might be connecting to a
526 * different server or share during failover. It could be improved by adding some logic to
527 * only do that in case it connects to a different server or share, though.
528 */
529 cifs_mark_tcp_ses_conns_for_reconnect(server, true);
530
531 cifs_abort_connection(server);
532
533 do {
534 try_to_freeze();
535 cifs_server_lock(server);
536
537 rc = reconnect_target_unlocked(server, &tl, &target_hint);
538 if (rc) {
539 /* Failed to reconnect socket */
540 cifs_server_unlock(server);
541 cifs_dbg(FYI, "%s: reconnect error %d\n", __func__, rc);
542 msleep(3000);
543 continue;
544 }
545 /*
546 * Socket was created. Update tcp session status to CifsNeedNegotiate so that a
547 * process waiting for reconnect will know it needs to re-establish session and tcon
548 * through the reconnected target server.
549 */
550 atomic_inc(&tcpSesReconnectCount);
551 set_credits(server, 1);
552 spin_lock(&server->srv_lock);
553 if (server->tcpStatus != CifsExiting)
554 server->tcpStatus = CifsNeedNegotiate;
555 spin_unlock(&server->srv_lock);
556 cifs_swn_reset_server_dstaddr(server);
557 cifs_server_unlock(server);
558 mod_delayed_work(cifsiod_wq, &server->reconnect, 0);
559 } while (server->tcpStatus == CifsNeedReconnect);
560
561 mutex_lock(&server->refpath_lock);
562 dfs_cache_noreq_update_tgthint(server->leaf_fullpath + 1, target_hint);
563 mutex_unlock(&server->refpath_lock);
564 dfs_cache_free_tgts(&tl);
565
566 /* Need to set up echo worker again once connection has been established */
567 spin_lock(&server->srv_lock);
568 if (server->tcpStatus == CifsNeedNegotiate)
569 mod_delayed_work(cifsiod_wq, &server->echo, 0);
570 spin_unlock(&server->srv_lock);
571
572 wake_up(&server->response_q);
573 return rc;
574 }
575
cifs_reconnect(struct TCP_Server_Info * server,bool mark_smb_session)576 int cifs_reconnect(struct TCP_Server_Info *server, bool mark_smb_session)
577 {
578 mutex_lock(&server->refpath_lock);
579 if (!server->leaf_fullpath) {
580 mutex_unlock(&server->refpath_lock);
581 return __cifs_reconnect(server, mark_smb_session);
582 }
583 mutex_unlock(&server->refpath_lock);
584
585 return reconnect_dfs_server(server);
586 }
587 #else
cifs_reconnect(struct TCP_Server_Info * server,bool mark_smb_session)588 int cifs_reconnect(struct TCP_Server_Info *server, bool mark_smb_session)
589 {
590 return __cifs_reconnect(server, mark_smb_session);
591 }
592 #endif
593
594 static void
cifs_echo_request(struct work_struct * work)595 cifs_echo_request(struct work_struct *work)
596 {
597 int rc;
598 struct TCP_Server_Info *server = container_of(work,
599 struct TCP_Server_Info, echo.work);
600
601 /*
602 * We cannot send an echo if it is disabled.
603 * Also, no need to ping if we got a response recently.
604 */
605
606 if (server->tcpStatus == CifsNeedReconnect ||
607 server->tcpStatus == CifsExiting ||
608 server->tcpStatus == CifsNew ||
609 (server->ops->can_echo && !server->ops->can_echo(server)) ||
610 time_before(jiffies, server->lstrp + server->echo_interval - HZ))
611 goto requeue_echo;
612
613 rc = server->ops->echo ? server->ops->echo(server) : -ENOSYS;
614 cifs_server_dbg(FYI, "send echo request: rc = %d\n", rc);
615
616 /* Check witness registrations */
617 cifs_swn_check();
618
619 requeue_echo:
620 queue_delayed_work(cifsiod_wq, &server->echo, server->echo_interval);
621 }
622
623 static bool
allocate_buffers(struct TCP_Server_Info * server)624 allocate_buffers(struct TCP_Server_Info *server)
625 {
626 if (!server->bigbuf) {
627 server->bigbuf = (char *)cifs_buf_get();
628 if (!server->bigbuf) {
629 cifs_server_dbg(VFS, "No memory for large SMB response\n");
630 msleep(3000);
631 /* retry will check if exiting */
632 return false;
633 }
634 } else if (server->large_buf) {
635 /* we are reusing a dirty large buf, clear its start */
636 memset(server->bigbuf, 0, HEADER_SIZE(server));
637 }
638
639 if (!server->smallbuf) {
640 server->smallbuf = (char *)cifs_small_buf_get();
641 if (!server->smallbuf) {
642 cifs_server_dbg(VFS, "No memory for SMB response\n");
643 msleep(1000);
644 /* retry will check if exiting */
645 return false;
646 }
647 /* beginning of smb buffer is cleared in our buf_get */
648 } else {
649 /* if existing small buf clear beginning */
650 memset(server->smallbuf, 0, HEADER_SIZE(server));
651 }
652
653 return true;
654 }
655
656 static bool
server_unresponsive(struct TCP_Server_Info * server)657 server_unresponsive(struct TCP_Server_Info *server)
658 {
659 /*
660 * If we're in the process of mounting a share or reconnecting a session
661 * and the server abruptly shut down (e.g. socket wasn't closed, packet
662 * had been ACK'ed but no SMB response), don't wait longer than 20s to
663 * negotiate protocol.
664 */
665 spin_lock(&server->srv_lock);
666 if (server->tcpStatus == CifsInNegotiate &&
667 time_after(jiffies, server->lstrp + 20 * HZ)) {
668 spin_unlock(&server->srv_lock);
669 cifs_reconnect(server, false);
670 return true;
671 }
672 /*
673 * We need to wait 3 echo intervals to make sure we handle such
674 * situations right:
675 * 1s client sends a normal SMB request
676 * 2s client gets a response
677 * 30s echo workqueue job pops, and decides we got a response recently
678 * and don't need to send another
679 * ...
680 * 65s kernel_recvmsg times out, and we see that we haven't gotten
681 * a response in >60s.
682 */
683 if ((server->tcpStatus == CifsGood ||
684 server->tcpStatus == CifsNeedNegotiate) &&
685 (!server->ops->can_echo || server->ops->can_echo(server)) &&
686 time_after(jiffies, server->lstrp + 3 * server->echo_interval)) {
687 spin_unlock(&server->srv_lock);
688 cifs_server_dbg(VFS, "has not responded in %lu seconds. Reconnecting...\n",
689 (3 * server->echo_interval) / HZ);
690 cifs_reconnect(server, false);
691 return true;
692 }
693 spin_unlock(&server->srv_lock);
694
695 return false;
696 }
697
698 static inline bool
zero_credits(struct TCP_Server_Info * server)699 zero_credits(struct TCP_Server_Info *server)
700 {
701 int val;
702
703 spin_lock(&server->req_lock);
704 val = server->credits + server->echo_credits + server->oplock_credits;
705 if (server->in_flight == 0 && val == 0) {
706 spin_unlock(&server->req_lock);
707 return true;
708 }
709 spin_unlock(&server->req_lock);
710 return false;
711 }
712
713 static int
cifs_readv_from_socket(struct TCP_Server_Info * server,struct msghdr * smb_msg)714 cifs_readv_from_socket(struct TCP_Server_Info *server, struct msghdr *smb_msg)
715 {
716 int length = 0;
717 int total_read;
718
719 for (total_read = 0; msg_data_left(smb_msg); total_read += length) {
720 try_to_freeze();
721
722 /* reconnect if no credits and no requests in flight */
723 if (zero_credits(server)) {
724 cifs_reconnect(server, false);
725 return -ECONNABORTED;
726 }
727
728 if (server_unresponsive(server))
729 return -ECONNABORTED;
730 if (cifs_rdma_enabled(server) && server->smbd_conn)
731 length = smbd_recv(server->smbd_conn, smb_msg);
732 else
733 length = sock_recvmsg(server->ssocket, smb_msg, 0);
734
735 spin_lock(&server->srv_lock);
736 if (server->tcpStatus == CifsExiting) {
737 spin_unlock(&server->srv_lock);
738 return -ESHUTDOWN;
739 }
740
741 if (server->tcpStatus == CifsNeedReconnect) {
742 spin_unlock(&server->srv_lock);
743 cifs_reconnect(server, false);
744 return -ECONNABORTED;
745 }
746 spin_unlock(&server->srv_lock);
747
748 if (length == -ERESTARTSYS ||
749 length == -EAGAIN ||
750 length == -EINTR) {
751 /*
752 * Minimum sleep to prevent looping, allowing socket
753 * to clear and app threads to set tcpStatus
754 * CifsNeedReconnect if server hung.
755 */
756 usleep_range(1000, 2000);
757 length = 0;
758 continue;
759 }
760
761 if (length <= 0) {
762 cifs_dbg(FYI, "Received no data or error: %d\n", length);
763 cifs_reconnect(server, false);
764 return -ECONNABORTED;
765 }
766 }
767 return total_read;
768 }
769
770 int
cifs_read_from_socket(struct TCP_Server_Info * server,char * buf,unsigned int to_read)771 cifs_read_from_socket(struct TCP_Server_Info *server, char *buf,
772 unsigned int to_read)
773 {
774 struct msghdr smb_msg = {};
775 struct kvec iov = {.iov_base = buf, .iov_len = to_read};
776
777 iov_iter_kvec(&smb_msg.msg_iter, ITER_DEST, &iov, 1, to_read);
778
779 return cifs_readv_from_socket(server, &smb_msg);
780 }
781
782 ssize_t
cifs_discard_from_socket(struct TCP_Server_Info * server,size_t to_read)783 cifs_discard_from_socket(struct TCP_Server_Info *server, size_t to_read)
784 {
785 struct msghdr smb_msg = {};
786
787 /*
788 * iov_iter_discard already sets smb_msg.type and count and iov_offset
789 * and cifs_readv_from_socket sets msg_control and msg_controllen
790 * so little to initialize in struct msghdr
791 */
792 iov_iter_discard(&smb_msg.msg_iter, ITER_DEST, to_read);
793
794 return cifs_readv_from_socket(server, &smb_msg);
795 }
796
797 int
cifs_read_iter_from_socket(struct TCP_Server_Info * server,struct iov_iter * iter,unsigned int to_read)798 cifs_read_iter_from_socket(struct TCP_Server_Info *server, struct iov_iter *iter,
799 unsigned int to_read)
800 {
801 struct msghdr smb_msg = { .msg_iter = *iter };
802
803 iov_iter_truncate(&smb_msg.msg_iter, to_read);
804 return cifs_readv_from_socket(server, &smb_msg);
805 }
806
807 static bool
is_smb_response(struct TCP_Server_Info * server,unsigned char type)808 is_smb_response(struct TCP_Server_Info *server, unsigned char type)
809 {
810 /*
811 * The first byte big endian of the length field,
812 * is actually not part of the length but the type
813 * with the most common, zero, as regular data.
814 */
815 switch (type) {
816 case RFC1002_SESSION_MESSAGE:
817 /* Regular SMB response */
818 return true;
819 case RFC1002_SESSION_KEEP_ALIVE:
820 cifs_dbg(FYI, "RFC 1002 session keep alive\n");
821 break;
822 case RFC1002_POSITIVE_SESSION_RESPONSE:
823 cifs_dbg(FYI, "RFC 1002 positive session response\n");
824 break;
825 case RFC1002_NEGATIVE_SESSION_RESPONSE:
826 /*
827 * We get this from Windows 98 instead of an error on
828 * SMB negprot response.
829 */
830 cifs_dbg(FYI, "RFC 1002 negative session response\n");
831 /* give server a second to clean up */
832 msleep(1000);
833 /*
834 * Always try 445 first on reconnect since we get NACK
835 * on some if we ever connected to port 139 (the NACK
836 * is since we do not begin with RFC1001 session
837 * initialize frame).
838 */
839 cifs_set_port((struct sockaddr *)&server->dstaddr, CIFS_PORT);
840 cifs_reconnect(server, true);
841 break;
842 default:
843 cifs_server_dbg(VFS, "RFC 1002 unknown response type 0x%x\n", type);
844 cifs_reconnect(server, true);
845 }
846
847 return false;
848 }
849
850 void
dequeue_mid(struct mid_q_entry * mid,bool malformed)851 dequeue_mid(struct mid_q_entry *mid, bool malformed)
852 {
853 #ifdef CONFIG_CIFS_STATS2
854 mid->when_received = jiffies;
855 #endif
856 spin_lock(&mid->server->mid_lock);
857 if (!malformed)
858 mid->mid_state = MID_RESPONSE_RECEIVED;
859 else
860 mid->mid_state = MID_RESPONSE_MALFORMED;
861 /*
862 * Trying to handle/dequeue a mid after the send_recv()
863 * function has finished processing it is a bug.
864 */
865 if (mid->mid_flags & MID_DELETED) {
866 spin_unlock(&mid->server->mid_lock);
867 pr_warn_once("trying to dequeue a deleted mid\n");
868 } else {
869 list_del_init(&mid->qhead);
870 mid->mid_flags |= MID_DELETED;
871 spin_unlock(&mid->server->mid_lock);
872 }
873 }
874
875 static unsigned int
smb2_get_credits_from_hdr(char * buffer,struct TCP_Server_Info * server)876 smb2_get_credits_from_hdr(char *buffer, struct TCP_Server_Info *server)
877 {
878 struct smb2_hdr *shdr = (struct smb2_hdr *)buffer;
879
880 /*
881 * SMB1 does not use credits.
882 */
883 if (is_smb1(server))
884 return 0;
885
886 return le16_to_cpu(shdr->CreditRequest);
887 }
888
889 static void
handle_mid(struct mid_q_entry * mid,struct TCP_Server_Info * server,char * buf,int malformed)890 handle_mid(struct mid_q_entry *mid, struct TCP_Server_Info *server,
891 char *buf, int malformed)
892 {
893 if (server->ops->check_trans2 &&
894 server->ops->check_trans2(mid, server, buf, malformed))
895 return;
896 mid->credits_received = smb2_get_credits_from_hdr(buf, server);
897 mid->resp_buf = buf;
898 mid->large_buf = server->large_buf;
899 /* Was previous buf put in mpx struct for multi-rsp? */
900 if (!mid->multiRsp) {
901 /* smb buffer will be freed by user thread */
902 if (server->large_buf)
903 server->bigbuf = NULL;
904 else
905 server->smallbuf = NULL;
906 }
907 dequeue_mid(mid, malformed);
908 }
909
910 int
cifs_enable_signing(struct TCP_Server_Info * server,bool mnt_sign_required)911 cifs_enable_signing(struct TCP_Server_Info *server, bool mnt_sign_required)
912 {
913 bool srv_sign_required = server->sec_mode & server->vals->signing_required;
914 bool srv_sign_enabled = server->sec_mode & server->vals->signing_enabled;
915 bool mnt_sign_enabled;
916
917 /*
918 * Is signing required by mnt options? If not then check
919 * global_secflags to see if it is there.
920 */
921 if (!mnt_sign_required)
922 mnt_sign_required = ((global_secflags & CIFSSEC_MUST_SIGN) ==
923 CIFSSEC_MUST_SIGN);
924
925 /*
926 * If signing is required then it's automatically enabled too,
927 * otherwise, check to see if the secflags allow it.
928 */
929 mnt_sign_enabled = mnt_sign_required ? mnt_sign_required :
930 (global_secflags & CIFSSEC_MAY_SIGN);
931
932 /* If server requires signing, does client allow it? */
933 if (srv_sign_required) {
934 if (!mnt_sign_enabled) {
935 cifs_dbg(VFS, "Server requires signing, but it's disabled in SecurityFlags!\n");
936 return -EOPNOTSUPP;
937 }
938 server->sign = true;
939 }
940
941 /* If client requires signing, does server allow it? */
942 if (mnt_sign_required) {
943 if (!srv_sign_enabled) {
944 cifs_dbg(VFS, "Server does not support signing!\n");
945 return -EOPNOTSUPP;
946 }
947 server->sign = true;
948 }
949
950 if (cifs_rdma_enabled(server) && server->sign)
951 cifs_dbg(VFS, "Signing is enabled, and RDMA read/write will be disabled\n");
952
953 return 0;
954 }
955
956 static noinline_for_stack void
clean_demultiplex_info(struct TCP_Server_Info * server)957 clean_demultiplex_info(struct TCP_Server_Info *server)
958 {
959 int length;
960
961 /* take it off the list, if it's not already */
962 spin_lock(&server->srv_lock);
963 list_del_init(&server->tcp_ses_list);
964 spin_unlock(&server->srv_lock);
965
966 cancel_delayed_work_sync(&server->echo);
967
968 spin_lock(&server->srv_lock);
969 server->tcpStatus = CifsExiting;
970 spin_unlock(&server->srv_lock);
971 wake_up_all(&server->response_q);
972
973 /* check if we have blocked requests that need to free */
974 spin_lock(&server->req_lock);
975 if (server->credits <= 0)
976 server->credits = 1;
977 spin_unlock(&server->req_lock);
978 /*
979 * Although there should not be any requests blocked on this queue it
980 * can not hurt to be paranoid and try to wake up requests that may
981 * haven been blocked when more than 50 at time were on the wire to the
982 * same server - they now will see the session is in exit state and get
983 * out of SendReceive.
984 */
985 wake_up_all(&server->request_q);
986 /* give those requests time to exit */
987 msleep(125);
988 if (cifs_rdma_enabled(server))
989 smbd_destroy(server);
990 if (server->ssocket) {
991 sock_release(server->ssocket);
992 server->ssocket = NULL;
993 }
994
995 if (!list_empty(&server->pending_mid_q)) {
996 struct mid_q_entry *mid_entry;
997 struct list_head *tmp, *tmp2;
998 LIST_HEAD(dispose_list);
999
1000 spin_lock(&server->mid_lock);
1001 list_for_each_safe(tmp, tmp2, &server->pending_mid_q) {
1002 mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
1003 cifs_dbg(FYI, "Clearing mid %llu\n", mid_entry->mid);
1004 kref_get(&mid_entry->refcount);
1005 mid_entry->mid_state = MID_SHUTDOWN;
1006 list_move(&mid_entry->qhead, &dispose_list);
1007 mid_entry->mid_flags |= MID_DELETED;
1008 }
1009 spin_unlock(&server->mid_lock);
1010
1011 /* now walk dispose list and issue callbacks */
1012 list_for_each_safe(tmp, tmp2, &dispose_list) {
1013 mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
1014 cifs_dbg(FYI, "Callback mid %llu\n", mid_entry->mid);
1015 list_del_init(&mid_entry->qhead);
1016 mid_entry->callback(mid_entry);
1017 release_mid(mid_entry);
1018 }
1019 /* 1/8th of sec is more than enough time for them to exit */
1020 msleep(125);
1021 }
1022
1023 if (!list_empty(&server->pending_mid_q)) {
1024 /*
1025 * mpx threads have not exited yet give them at least the smb
1026 * send timeout time for long ops.
1027 *
1028 * Due to delays on oplock break requests, we need to wait at
1029 * least 45 seconds before giving up on a request getting a
1030 * response and going ahead and killing cifsd.
1031 */
1032 cifs_dbg(FYI, "Wait for exit from demultiplex thread\n");
1033 msleep(46000);
1034 /*
1035 * If threads still have not exited they are probably never
1036 * coming home not much else we can do but free the memory.
1037 */
1038 }
1039
1040 put_net(cifs_net_ns(server));
1041 kfree(server->leaf_fullpath);
1042 kfree(server);
1043
1044 length = atomic_dec_return(&tcpSesAllocCount);
1045 if (length > 0)
1046 mempool_resize(cifs_req_poolp, length + cifs_min_rcv);
1047 }
1048
1049 static int
standard_receive3(struct TCP_Server_Info * server,struct mid_q_entry * mid)1050 standard_receive3(struct TCP_Server_Info *server, struct mid_q_entry *mid)
1051 {
1052 int length;
1053 char *buf = server->smallbuf;
1054 unsigned int pdu_length = server->pdu_size;
1055
1056 /* make sure this will fit in a large buffer */
1057 if (pdu_length > CIFSMaxBufSize + MAX_HEADER_SIZE(server) -
1058 HEADER_PREAMBLE_SIZE(server)) {
1059 cifs_server_dbg(VFS, "SMB response too long (%u bytes)\n", pdu_length);
1060 cifs_reconnect(server, true);
1061 return -ECONNABORTED;
1062 }
1063
1064 /* switch to large buffer if too big for a small one */
1065 if (pdu_length > MAX_CIFS_SMALL_BUFFER_SIZE - 4) {
1066 server->large_buf = true;
1067 memcpy(server->bigbuf, buf, server->total_read);
1068 buf = server->bigbuf;
1069 }
1070
1071 /* now read the rest */
1072 length = cifs_read_from_socket(server, buf + HEADER_SIZE(server) - 1,
1073 pdu_length - MID_HEADER_SIZE(server));
1074
1075 if (length < 0)
1076 return length;
1077 server->total_read += length;
1078
1079 dump_smb(buf, server->total_read);
1080
1081 return cifs_handle_standard(server, mid);
1082 }
1083
1084 int
cifs_handle_standard(struct TCP_Server_Info * server,struct mid_q_entry * mid)1085 cifs_handle_standard(struct TCP_Server_Info *server, struct mid_q_entry *mid)
1086 {
1087 char *buf = server->large_buf ? server->bigbuf : server->smallbuf;
1088 int rc;
1089
1090 /*
1091 * We know that we received enough to get to the MID as we
1092 * checked the pdu_length earlier. Now check to see
1093 * if the rest of the header is OK.
1094 *
1095 * 48 bytes is enough to display the header and a little bit
1096 * into the payload for debugging purposes.
1097 */
1098 rc = server->ops->check_message(buf, server->total_read, server);
1099 if (rc)
1100 cifs_dump_mem("Bad SMB: ", buf,
1101 min_t(unsigned int, server->total_read, 48));
1102
1103 if (server->ops->is_session_expired &&
1104 server->ops->is_session_expired(buf)) {
1105 cifs_reconnect(server, true);
1106 return -1;
1107 }
1108
1109 if (server->ops->is_status_pending &&
1110 server->ops->is_status_pending(buf, server))
1111 return -1;
1112
1113 if (!mid)
1114 return rc;
1115
1116 handle_mid(mid, server, buf, rc);
1117 return 0;
1118 }
1119
1120 static void
smb2_add_credits_from_hdr(char * buffer,struct TCP_Server_Info * server)1121 smb2_add_credits_from_hdr(char *buffer, struct TCP_Server_Info *server)
1122 {
1123 struct smb2_hdr *shdr = (struct smb2_hdr *)buffer;
1124 int scredits, in_flight;
1125
1126 /*
1127 * SMB1 does not use credits.
1128 */
1129 if (is_smb1(server))
1130 return;
1131
1132 if (shdr->CreditRequest) {
1133 spin_lock(&server->req_lock);
1134 server->credits += le16_to_cpu(shdr->CreditRequest);
1135 scredits = server->credits;
1136 in_flight = server->in_flight;
1137 spin_unlock(&server->req_lock);
1138 wake_up(&server->request_q);
1139
1140 trace_smb3_hdr_credits(server->CurrentMid,
1141 server->conn_id, server->hostname, scredits,
1142 le16_to_cpu(shdr->CreditRequest), in_flight);
1143 cifs_server_dbg(FYI, "%s: added %u credits total=%d\n",
1144 __func__, le16_to_cpu(shdr->CreditRequest),
1145 scredits);
1146 }
1147 }
1148
1149
1150 static int
cifs_demultiplex_thread(void * p)1151 cifs_demultiplex_thread(void *p)
1152 {
1153 int i, num_mids, length;
1154 struct TCP_Server_Info *server = p;
1155 unsigned int pdu_length;
1156 unsigned int next_offset;
1157 char *buf = NULL;
1158 struct task_struct *task_to_wake = NULL;
1159 struct mid_q_entry *mids[MAX_COMPOUND];
1160 char *bufs[MAX_COMPOUND];
1161 unsigned int noreclaim_flag, num_io_timeout = 0;
1162 bool pending_reconnect = false;
1163
1164 noreclaim_flag = memalloc_noreclaim_save();
1165 cifs_dbg(FYI, "Demultiplex PID: %d\n", task_pid_nr(current));
1166
1167 length = atomic_inc_return(&tcpSesAllocCount);
1168 if (length > 1)
1169 mempool_resize(cifs_req_poolp, length + cifs_min_rcv);
1170
1171 set_freezable();
1172 allow_kernel_signal(SIGKILL);
1173 while (server->tcpStatus != CifsExiting) {
1174 if (try_to_freeze())
1175 continue;
1176
1177 if (!allocate_buffers(server))
1178 continue;
1179
1180 server->large_buf = false;
1181 buf = server->smallbuf;
1182 pdu_length = 4; /* enough to get RFC1001 header */
1183
1184 length = cifs_read_from_socket(server, buf, pdu_length);
1185 if (length < 0)
1186 continue;
1187
1188 if (is_smb1(server))
1189 server->total_read = length;
1190 else
1191 server->total_read = 0;
1192
1193 /*
1194 * The right amount was read from socket - 4 bytes,
1195 * so we can now interpret the length field.
1196 */
1197 pdu_length = get_rfc1002_length(buf);
1198
1199 cifs_dbg(FYI, "RFC1002 header 0x%x\n", pdu_length);
1200 if (!is_smb_response(server, buf[0]))
1201 continue;
1202
1203 pending_reconnect = false;
1204 next_pdu:
1205 server->pdu_size = pdu_length;
1206
1207 /* make sure we have enough to get to the MID */
1208 if (server->pdu_size < MID_HEADER_SIZE(server)) {
1209 cifs_server_dbg(VFS, "SMB response too short (%u bytes)\n",
1210 server->pdu_size);
1211 cifs_reconnect(server, true);
1212 continue;
1213 }
1214
1215 /* read down to the MID */
1216 length = cifs_read_from_socket(server,
1217 buf + HEADER_PREAMBLE_SIZE(server),
1218 MID_HEADER_SIZE(server));
1219 if (length < 0)
1220 continue;
1221 server->total_read += length;
1222
1223 if (server->ops->next_header) {
1224 if (server->ops->next_header(server, buf, &next_offset)) {
1225 cifs_dbg(VFS, "%s: malformed response (next_offset=%u)\n",
1226 __func__, next_offset);
1227 cifs_reconnect(server, true);
1228 continue;
1229 }
1230 if (next_offset)
1231 server->pdu_size = next_offset;
1232 }
1233
1234 memset(mids, 0, sizeof(mids));
1235 memset(bufs, 0, sizeof(bufs));
1236 num_mids = 0;
1237
1238 if (server->ops->is_transform_hdr &&
1239 server->ops->receive_transform &&
1240 server->ops->is_transform_hdr(buf)) {
1241 length = server->ops->receive_transform(server,
1242 mids,
1243 bufs,
1244 &num_mids);
1245 } else {
1246 mids[0] = server->ops->find_mid(server, buf);
1247 bufs[0] = buf;
1248 num_mids = 1;
1249
1250 if (!mids[0] || !mids[0]->receive)
1251 length = standard_receive3(server, mids[0]);
1252 else
1253 length = mids[0]->receive(server, mids[0]);
1254 }
1255
1256 if (length < 0) {
1257 for (i = 0; i < num_mids; i++)
1258 if (mids[i])
1259 release_mid(mids[i]);
1260 continue;
1261 }
1262
1263 if (server->ops->is_status_io_timeout &&
1264 server->ops->is_status_io_timeout(buf)) {
1265 num_io_timeout++;
1266 if (num_io_timeout > MAX_STATUS_IO_TIMEOUT) {
1267 cifs_server_dbg(VFS,
1268 "Number of request timeouts exceeded %d. Reconnecting",
1269 MAX_STATUS_IO_TIMEOUT);
1270
1271 pending_reconnect = true;
1272 num_io_timeout = 0;
1273 }
1274 }
1275
1276 server->lstrp = jiffies;
1277
1278 for (i = 0; i < num_mids; i++) {
1279 if (mids[i] != NULL) {
1280 mids[i]->resp_buf_size = server->pdu_size;
1281
1282 if (bufs[i] != NULL) {
1283 if (server->ops->is_network_name_deleted &&
1284 server->ops->is_network_name_deleted(bufs[i],
1285 server)) {
1286 cifs_server_dbg(FYI,
1287 "Share deleted. Reconnect needed");
1288 }
1289 }
1290
1291 if (!mids[i]->multiRsp || mids[i]->multiEnd)
1292 mids[i]->callback(mids[i]);
1293
1294 release_mid(mids[i]);
1295 } else if (server->ops->is_oplock_break &&
1296 server->ops->is_oplock_break(bufs[i],
1297 server)) {
1298 smb2_add_credits_from_hdr(bufs[i], server);
1299 cifs_dbg(FYI, "Received oplock break\n");
1300 } else {
1301 cifs_server_dbg(VFS, "No task to wake, unknown frame received! NumMids %d\n",
1302 atomic_read(&mid_count));
1303 cifs_dump_mem("Received Data is: ", bufs[i],
1304 HEADER_SIZE(server));
1305 smb2_add_credits_from_hdr(bufs[i], server);
1306 #ifdef CONFIG_CIFS_DEBUG2
1307 if (server->ops->dump_detail)
1308 server->ops->dump_detail(bufs[i],
1309 server);
1310 cifs_dump_mids(server);
1311 #endif /* CIFS_DEBUG2 */
1312 }
1313 }
1314
1315 if (pdu_length > server->pdu_size) {
1316 if (!allocate_buffers(server))
1317 continue;
1318 pdu_length -= server->pdu_size;
1319 server->total_read = 0;
1320 server->large_buf = false;
1321 buf = server->smallbuf;
1322 goto next_pdu;
1323 }
1324
1325 /* do this reconnect at the very end after processing all MIDs */
1326 if (pending_reconnect)
1327 cifs_reconnect(server, true);
1328
1329 } /* end while !EXITING */
1330
1331 /* buffer usually freed in free_mid - need to free it here on exit */
1332 cifs_buf_release(server->bigbuf);
1333 if (server->smallbuf) /* no sense logging a debug message if NULL */
1334 cifs_small_buf_release(server->smallbuf);
1335
1336 task_to_wake = xchg(&server->tsk, NULL);
1337 clean_demultiplex_info(server);
1338
1339 /* if server->tsk was NULL then wait for a signal before exiting */
1340 if (!task_to_wake) {
1341 set_current_state(TASK_INTERRUPTIBLE);
1342 while (!signal_pending(current)) {
1343 schedule();
1344 set_current_state(TASK_INTERRUPTIBLE);
1345 }
1346 set_current_state(TASK_RUNNING);
1347 }
1348
1349 memalloc_noreclaim_restore(noreclaim_flag);
1350 module_put_and_kthread_exit(0);
1351 }
1352
1353 int
cifs_ipaddr_cmp(struct sockaddr * srcaddr,struct sockaddr * rhs)1354 cifs_ipaddr_cmp(struct sockaddr *srcaddr, struct sockaddr *rhs)
1355 {
1356 struct sockaddr_in *saddr4 = (struct sockaddr_in *)srcaddr;
1357 struct sockaddr_in *vaddr4 = (struct sockaddr_in *)rhs;
1358 struct sockaddr_in6 *saddr6 = (struct sockaddr_in6 *)srcaddr;
1359 struct sockaddr_in6 *vaddr6 = (struct sockaddr_in6 *)rhs;
1360
1361 switch (srcaddr->sa_family) {
1362 case AF_UNSPEC:
1363 switch (rhs->sa_family) {
1364 case AF_UNSPEC:
1365 return 0;
1366 case AF_INET:
1367 case AF_INET6:
1368 return 1;
1369 default:
1370 return -1;
1371 }
1372 case AF_INET: {
1373 switch (rhs->sa_family) {
1374 case AF_UNSPEC:
1375 return -1;
1376 case AF_INET:
1377 return memcmp(saddr4, vaddr4,
1378 sizeof(struct sockaddr_in));
1379 case AF_INET6:
1380 return 1;
1381 default:
1382 return -1;
1383 }
1384 }
1385 case AF_INET6: {
1386 switch (rhs->sa_family) {
1387 case AF_UNSPEC:
1388 case AF_INET:
1389 return -1;
1390 case AF_INET6:
1391 return memcmp(saddr6,
1392 vaddr6,
1393 sizeof(struct sockaddr_in6));
1394 default:
1395 return -1;
1396 }
1397 }
1398 default:
1399 return -1; /* don't expect to be here */
1400 }
1401 }
1402
1403 /*
1404 * Returns true if srcaddr isn't specified and rhs isn't specified, or
1405 * if srcaddr is specified and matches the IP address of the rhs argument
1406 */
1407 bool
cifs_match_ipaddr(struct sockaddr * srcaddr,struct sockaddr * rhs)1408 cifs_match_ipaddr(struct sockaddr *srcaddr, struct sockaddr *rhs)
1409 {
1410 switch (srcaddr->sa_family) {
1411 case AF_UNSPEC:
1412 return (rhs->sa_family == AF_UNSPEC);
1413 case AF_INET: {
1414 struct sockaddr_in *saddr4 = (struct sockaddr_in *)srcaddr;
1415 struct sockaddr_in *vaddr4 = (struct sockaddr_in *)rhs;
1416
1417 return (saddr4->sin_addr.s_addr == vaddr4->sin_addr.s_addr);
1418 }
1419 case AF_INET6: {
1420 struct sockaddr_in6 *saddr6 = (struct sockaddr_in6 *)srcaddr;
1421 struct sockaddr_in6 *vaddr6 = (struct sockaddr_in6 *)rhs;
1422
1423 return (ipv6_addr_equal(&saddr6->sin6_addr, &vaddr6->sin6_addr)
1424 && saddr6->sin6_scope_id == vaddr6->sin6_scope_id);
1425 }
1426 default:
1427 WARN_ON(1);
1428 return false; /* don't expect to be here */
1429 }
1430 }
1431
1432 /*
1433 * If no port is specified in addr structure, we try to match with 445 port
1434 * and if it fails - with 139 ports. It should be called only if address
1435 * families of server and addr are equal.
1436 */
1437 static bool
match_port(struct TCP_Server_Info * server,struct sockaddr * addr)1438 match_port(struct TCP_Server_Info *server, struct sockaddr *addr)
1439 {
1440 __be16 port, *sport;
1441
1442 /* SMBDirect manages its own ports, don't match it here */
1443 if (server->rdma)
1444 return true;
1445
1446 switch (addr->sa_family) {
1447 case AF_INET:
1448 sport = &((struct sockaddr_in *) &server->dstaddr)->sin_port;
1449 port = ((struct sockaddr_in *) addr)->sin_port;
1450 break;
1451 case AF_INET6:
1452 sport = &((struct sockaddr_in6 *) &server->dstaddr)->sin6_port;
1453 port = ((struct sockaddr_in6 *) addr)->sin6_port;
1454 break;
1455 default:
1456 WARN_ON(1);
1457 return false;
1458 }
1459
1460 if (!port) {
1461 port = htons(CIFS_PORT);
1462 if (port == *sport)
1463 return true;
1464
1465 port = htons(RFC1001_PORT);
1466 }
1467
1468 return port == *sport;
1469 }
1470
match_server_address(struct TCP_Server_Info * server,struct sockaddr * addr)1471 static bool match_server_address(struct TCP_Server_Info *server, struct sockaddr *addr)
1472 {
1473 if (!cifs_match_ipaddr(addr, (struct sockaddr *)&server->dstaddr))
1474 return false;
1475
1476 return true;
1477 }
1478
1479 static bool
match_security(struct TCP_Server_Info * server,struct smb3_fs_context * ctx)1480 match_security(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
1481 {
1482 /*
1483 * The select_sectype function should either return the ctx->sectype
1484 * that was specified, or "Unspecified" if that sectype was not
1485 * compatible with the given NEGOTIATE request.
1486 */
1487 if (server->ops->select_sectype(server, ctx->sectype)
1488 == Unspecified)
1489 return false;
1490
1491 /*
1492 * Now check if signing mode is acceptable. No need to check
1493 * global_secflags at this point since if MUST_SIGN is set then
1494 * the server->sign had better be too.
1495 */
1496 if (ctx->sign && !server->sign)
1497 return false;
1498
1499 return true;
1500 }
1501
1502 /* this function must be called with srv_lock held */
match_server(struct TCP_Server_Info * server,struct smb3_fs_context * ctx,bool match_super)1503 static int match_server(struct TCP_Server_Info *server,
1504 struct smb3_fs_context *ctx,
1505 bool match_super)
1506 {
1507 struct sockaddr *addr = (struct sockaddr *)&ctx->dstaddr;
1508
1509 lockdep_assert_held(&server->srv_lock);
1510
1511 if (ctx->nosharesock)
1512 return 0;
1513
1514 /* this server does not share socket */
1515 if (server->nosharesock)
1516 return 0;
1517
1518 if (!match_super && (ctx->dfs_conn || server->dfs_conn))
1519 return 0;
1520
1521 /* If multidialect negotiation see if existing sessions match one */
1522 if (strcmp(ctx->vals->version_string, SMB3ANY_VERSION_STRING) == 0) {
1523 if (server->vals->protocol_id < SMB30_PROT_ID)
1524 return 0;
1525 } else if (strcmp(ctx->vals->version_string,
1526 SMBDEFAULT_VERSION_STRING) == 0) {
1527 if (server->vals->protocol_id < SMB21_PROT_ID)
1528 return 0;
1529 } else if ((server->vals != ctx->vals) || (server->ops != ctx->ops))
1530 return 0;
1531
1532 if (!net_eq(cifs_net_ns(server), current->nsproxy->net_ns))
1533 return 0;
1534
1535 if (!cifs_match_ipaddr((struct sockaddr *)&ctx->srcaddr,
1536 (struct sockaddr *)&server->srcaddr))
1537 return 0;
1538 /*
1539 * When matching cifs.ko superblocks (@match_super == true), we can't
1540 * really match either @server->leaf_fullpath or @server->dstaddr
1541 * directly since this @server might belong to a completely different
1542 * server -- in case of domain-based DFS referrals or DFS links -- as
1543 * provided earlier by mount(2) through 'source' and 'ip' options.
1544 *
1545 * Otherwise, match the DFS referral in @server->leaf_fullpath or the
1546 * destination address in @server->dstaddr.
1547 *
1548 * When using 'nodfs' mount option, we avoid sharing it with DFS
1549 * connections as they might failover.
1550 */
1551 if (!match_super) {
1552 if (!ctx->nodfs) {
1553 if (server->leaf_fullpath) {
1554 if (!ctx->leaf_fullpath ||
1555 strcasecmp(server->leaf_fullpath,
1556 ctx->leaf_fullpath))
1557 return 0;
1558 } else if (ctx->leaf_fullpath) {
1559 return 0;
1560 }
1561 } else if (server->leaf_fullpath) {
1562 return 0;
1563 }
1564 }
1565
1566 /*
1567 * Match for a regular connection (address/hostname/port) which has no
1568 * DFS referrals set.
1569 */
1570 if (!server->leaf_fullpath &&
1571 (strcasecmp(server->hostname, ctx->server_hostname) ||
1572 !match_server_address(server, addr) ||
1573 !match_port(server, addr)))
1574 return 0;
1575
1576 if (!match_security(server, ctx))
1577 return 0;
1578
1579 if (server->echo_interval != ctx->echo_interval * HZ)
1580 return 0;
1581
1582 if (server->rdma != ctx->rdma)
1583 return 0;
1584
1585 if (server->ignore_signature != ctx->ignore_signature)
1586 return 0;
1587
1588 if (server->min_offload != ctx->min_offload)
1589 return 0;
1590
1591 if (server->retrans != ctx->retrans)
1592 return 0;
1593
1594 return 1;
1595 }
1596
1597 struct TCP_Server_Info *
cifs_find_tcp_session(struct smb3_fs_context * ctx)1598 cifs_find_tcp_session(struct smb3_fs_context *ctx)
1599 {
1600 struct TCP_Server_Info *server;
1601
1602 spin_lock(&cifs_tcp_ses_lock);
1603 list_for_each_entry(server, &cifs_tcp_ses_list, tcp_ses_list) {
1604 spin_lock(&server->srv_lock);
1605 /*
1606 * Skip ses channels since they're only handled in lower layers
1607 * (e.g. cifs_send_recv).
1608 */
1609 if (SERVER_IS_CHAN(server) ||
1610 !match_server(server, ctx, false)) {
1611 spin_unlock(&server->srv_lock);
1612 continue;
1613 }
1614 spin_unlock(&server->srv_lock);
1615
1616 ++server->srv_count;
1617 spin_unlock(&cifs_tcp_ses_lock);
1618 cifs_dbg(FYI, "Existing tcp session with server found\n");
1619 return server;
1620 }
1621 spin_unlock(&cifs_tcp_ses_lock);
1622 return NULL;
1623 }
1624
1625 void
cifs_put_tcp_session(struct TCP_Server_Info * server,int from_reconnect)1626 cifs_put_tcp_session(struct TCP_Server_Info *server, int from_reconnect)
1627 {
1628 struct task_struct *task;
1629
1630 spin_lock(&cifs_tcp_ses_lock);
1631 if (--server->srv_count > 0) {
1632 spin_unlock(&cifs_tcp_ses_lock);
1633 return;
1634 }
1635
1636 /* srv_count can never go negative */
1637 WARN_ON(server->srv_count < 0);
1638
1639 list_del_init(&server->tcp_ses_list);
1640 spin_unlock(&cifs_tcp_ses_lock);
1641
1642 cancel_delayed_work_sync(&server->echo);
1643
1644 if (from_reconnect)
1645 /*
1646 * Avoid deadlock here: reconnect work calls
1647 * cifs_put_tcp_session() at its end. Need to be sure
1648 * that reconnect work does nothing with server pointer after
1649 * that step.
1650 */
1651 cancel_delayed_work(&server->reconnect);
1652 else
1653 cancel_delayed_work_sync(&server->reconnect);
1654
1655 /* For secondary channels, we pick up ref-count on the primary server */
1656 if (SERVER_IS_CHAN(server))
1657 cifs_put_tcp_session(server->primary_server, from_reconnect);
1658
1659 spin_lock(&server->srv_lock);
1660 server->tcpStatus = CifsExiting;
1661 spin_unlock(&server->srv_lock);
1662
1663 cifs_crypto_secmech_release(server);
1664
1665 kfree_sensitive(server->session_key.response);
1666 server->session_key.response = NULL;
1667 server->session_key.len = 0;
1668 kfree(server->hostname);
1669 server->hostname = NULL;
1670
1671 task = xchg(&server->tsk, NULL);
1672 if (task)
1673 send_sig(SIGKILL, task, 1);
1674 }
1675
1676 struct TCP_Server_Info *
cifs_get_tcp_session(struct smb3_fs_context * ctx,struct TCP_Server_Info * primary_server)1677 cifs_get_tcp_session(struct smb3_fs_context *ctx,
1678 struct TCP_Server_Info *primary_server)
1679 {
1680 struct TCP_Server_Info *tcp_ses = NULL;
1681 int rc;
1682
1683 cifs_dbg(FYI, "UNC: %s\n", ctx->UNC);
1684
1685 /* see if we already have a matching tcp_ses */
1686 tcp_ses = cifs_find_tcp_session(ctx);
1687 if (tcp_ses)
1688 return tcp_ses;
1689
1690 tcp_ses = kzalloc(sizeof(struct TCP_Server_Info), GFP_KERNEL);
1691 if (!tcp_ses) {
1692 rc = -ENOMEM;
1693 goto out_err;
1694 }
1695
1696 tcp_ses->hostname = kstrdup(ctx->server_hostname, GFP_KERNEL);
1697 if (!tcp_ses->hostname) {
1698 rc = -ENOMEM;
1699 goto out_err;
1700 }
1701
1702 if (ctx->leaf_fullpath) {
1703 tcp_ses->leaf_fullpath = kstrdup(ctx->leaf_fullpath, GFP_KERNEL);
1704 if (!tcp_ses->leaf_fullpath) {
1705 rc = -ENOMEM;
1706 goto out_err;
1707 }
1708 }
1709
1710 if (ctx->nosharesock)
1711 tcp_ses->nosharesock = true;
1712 tcp_ses->dfs_conn = ctx->dfs_conn;
1713
1714 tcp_ses->ops = ctx->ops;
1715 tcp_ses->vals = ctx->vals;
1716 cifs_set_net_ns(tcp_ses, get_net(current->nsproxy->net_ns));
1717
1718 tcp_ses->conn_id = atomic_inc_return(&tcpSesNextId);
1719 tcp_ses->noblockcnt = ctx->rootfs;
1720 tcp_ses->noblocksnd = ctx->noblocksnd || ctx->rootfs;
1721 tcp_ses->noautotune = ctx->noautotune;
1722 tcp_ses->tcp_nodelay = ctx->sockopt_tcp_nodelay;
1723 tcp_ses->rdma = ctx->rdma;
1724 tcp_ses->in_flight = 0;
1725 tcp_ses->max_in_flight = 0;
1726 tcp_ses->credits = 1;
1727 if (primary_server) {
1728 spin_lock(&cifs_tcp_ses_lock);
1729 ++primary_server->srv_count;
1730 spin_unlock(&cifs_tcp_ses_lock);
1731 tcp_ses->primary_server = primary_server;
1732 }
1733 init_waitqueue_head(&tcp_ses->response_q);
1734 init_waitqueue_head(&tcp_ses->request_q);
1735 INIT_LIST_HEAD(&tcp_ses->pending_mid_q);
1736 mutex_init(&tcp_ses->_srv_mutex);
1737 memcpy(tcp_ses->workstation_RFC1001_name,
1738 ctx->source_rfc1001_name, RFC1001_NAME_LEN_WITH_NULL);
1739 memcpy(tcp_ses->server_RFC1001_name,
1740 ctx->target_rfc1001_name, RFC1001_NAME_LEN_WITH_NULL);
1741 tcp_ses->session_estab = false;
1742 tcp_ses->sequence_number = 0;
1743 tcp_ses->channel_sequence_num = 0; /* only tracked for primary channel */
1744 tcp_ses->reconnect_instance = 1;
1745 tcp_ses->lstrp = jiffies;
1746 tcp_ses->compression.requested = ctx->compress;
1747 spin_lock_init(&tcp_ses->req_lock);
1748 spin_lock_init(&tcp_ses->srv_lock);
1749 spin_lock_init(&tcp_ses->mid_lock);
1750 INIT_LIST_HEAD(&tcp_ses->tcp_ses_list);
1751 INIT_LIST_HEAD(&tcp_ses->smb_ses_list);
1752 INIT_DELAYED_WORK(&tcp_ses->echo, cifs_echo_request);
1753 INIT_DELAYED_WORK(&tcp_ses->reconnect, smb2_reconnect_server);
1754 mutex_init(&tcp_ses->reconnect_mutex);
1755 #ifdef CONFIG_CIFS_DFS_UPCALL
1756 mutex_init(&tcp_ses->refpath_lock);
1757 #endif
1758 memcpy(&tcp_ses->srcaddr, &ctx->srcaddr,
1759 sizeof(tcp_ses->srcaddr));
1760 memcpy(&tcp_ses->dstaddr, &ctx->dstaddr,
1761 sizeof(tcp_ses->dstaddr));
1762 if (ctx->use_client_guid)
1763 memcpy(tcp_ses->client_guid, ctx->client_guid,
1764 SMB2_CLIENT_GUID_SIZE);
1765 else
1766 generate_random_uuid(tcp_ses->client_guid);
1767 /*
1768 * at this point we are the only ones with the pointer
1769 * to the struct since the kernel thread not created yet
1770 * no need to spinlock this init of tcpStatus or srv_count
1771 */
1772 tcp_ses->tcpStatus = CifsNew;
1773 ++tcp_ses->srv_count;
1774
1775 if (ctx->echo_interval >= SMB_ECHO_INTERVAL_MIN &&
1776 ctx->echo_interval <= SMB_ECHO_INTERVAL_MAX)
1777 tcp_ses->echo_interval = ctx->echo_interval * HZ;
1778 else
1779 tcp_ses->echo_interval = SMB_ECHO_INTERVAL_DEFAULT * HZ;
1780 if (tcp_ses->rdma) {
1781 #ifndef CONFIG_CIFS_SMB_DIRECT
1782 cifs_dbg(VFS, "CONFIG_CIFS_SMB_DIRECT is not enabled\n");
1783 rc = -ENOENT;
1784 goto out_err_crypto_release;
1785 #endif
1786 tcp_ses->smbd_conn = smbd_get_connection(
1787 tcp_ses, (struct sockaddr *)&ctx->dstaddr);
1788 if (tcp_ses->smbd_conn) {
1789 cifs_dbg(VFS, "RDMA transport established\n");
1790 rc = 0;
1791 goto smbd_connected;
1792 } else {
1793 rc = -ENOENT;
1794 goto out_err_crypto_release;
1795 }
1796 }
1797 rc = ip_connect(tcp_ses);
1798 if (rc < 0) {
1799 cifs_dbg(VFS, "Error connecting to socket. Aborting operation.\n");
1800 goto out_err_crypto_release;
1801 }
1802 smbd_connected:
1803 /*
1804 * since we're in a cifs function already, we know that
1805 * this will succeed. No need for try_module_get().
1806 */
1807 __module_get(THIS_MODULE);
1808 tcp_ses->tsk = kthread_run(cifs_demultiplex_thread,
1809 tcp_ses, "cifsd");
1810 if (IS_ERR(tcp_ses->tsk)) {
1811 rc = PTR_ERR(tcp_ses->tsk);
1812 cifs_dbg(VFS, "error %d create cifsd thread\n", rc);
1813 module_put(THIS_MODULE);
1814 goto out_err_crypto_release;
1815 }
1816 tcp_ses->min_offload = ctx->min_offload;
1817 tcp_ses->retrans = ctx->retrans;
1818 /*
1819 * at this point we are the only ones with the pointer
1820 * to the struct since the kernel thread not created yet
1821 * no need to spinlock this update of tcpStatus
1822 */
1823 spin_lock(&tcp_ses->srv_lock);
1824 tcp_ses->tcpStatus = CifsNeedNegotiate;
1825 spin_unlock(&tcp_ses->srv_lock);
1826
1827 if ((ctx->max_credits < 20) || (ctx->max_credits > 60000))
1828 tcp_ses->max_credits = SMB2_MAX_CREDITS_AVAILABLE;
1829 else
1830 tcp_ses->max_credits = ctx->max_credits;
1831
1832 tcp_ses->nr_targets = 1;
1833 tcp_ses->ignore_signature = ctx->ignore_signature;
1834 /* thread spawned, put it on the list */
1835 spin_lock(&cifs_tcp_ses_lock);
1836 list_add(&tcp_ses->tcp_ses_list, &cifs_tcp_ses_list);
1837 spin_unlock(&cifs_tcp_ses_lock);
1838
1839 /* queue echo request delayed work */
1840 queue_delayed_work(cifsiod_wq, &tcp_ses->echo, tcp_ses->echo_interval);
1841
1842 return tcp_ses;
1843
1844 out_err_crypto_release:
1845 cifs_crypto_secmech_release(tcp_ses);
1846
1847 put_net(cifs_net_ns(tcp_ses));
1848
1849 out_err:
1850 if (tcp_ses) {
1851 if (SERVER_IS_CHAN(tcp_ses))
1852 cifs_put_tcp_session(tcp_ses->primary_server, false);
1853 kfree(tcp_ses->hostname);
1854 kfree(tcp_ses->leaf_fullpath);
1855 if (tcp_ses->ssocket)
1856 sock_release(tcp_ses->ssocket);
1857 kfree(tcp_ses);
1858 }
1859 return ERR_PTR(rc);
1860 }
1861
1862 /* this function must be called with ses_lock and chan_lock held */
match_session(struct cifs_ses * ses,struct smb3_fs_context * ctx,bool match_super)1863 static int match_session(struct cifs_ses *ses,
1864 struct smb3_fs_context *ctx,
1865 bool match_super)
1866 {
1867 if (ctx->sectype != Unspecified &&
1868 ctx->sectype != ses->sectype)
1869 return 0;
1870
1871 if (!match_super && ctx->dfs_root_ses != ses->dfs_root_ses)
1872 return 0;
1873
1874 /*
1875 * If an existing session is limited to less channels than
1876 * requested, it should not be reused
1877 */
1878 if (ses->chan_max < ctx->max_channels)
1879 return 0;
1880
1881 switch (ses->sectype) {
1882 case Kerberos:
1883 if (!uid_eq(ctx->cred_uid, ses->cred_uid))
1884 return 0;
1885 break;
1886 default:
1887 /* NULL username means anonymous session */
1888 if (ses->user_name == NULL) {
1889 if (!ctx->nullauth)
1890 return 0;
1891 break;
1892 }
1893
1894 /* anything else takes username/password */
1895 if (strncmp(ses->user_name,
1896 ctx->username ? ctx->username : "",
1897 CIFS_MAX_USERNAME_LEN))
1898 return 0;
1899 if ((ctx->username && strlen(ctx->username) != 0) &&
1900 ses->password != NULL &&
1901 strncmp(ses->password,
1902 ctx->password ? ctx->password : "",
1903 CIFS_MAX_PASSWORD_LEN))
1904 return 0;
1905 }
1906
1907 if (strcmp(ctx->local_nls->charset, ses->local_nls->charset))
1908 return 0;
1909
1910 return 1;
1911 }
1912
1913 /**
1914 * cifs_setup_ipc - helper to setup the IPC tcon for the session
1915 * @ses: smb session to issue the request on
1916 * @ctx: the superblock configuration context to use for building the
1917 * new tree connection for the IPC (interprocess communication RPC)
1918 *
1919 * A new IPC connection is made and stored in the session
1920 * tcon_ipc. The IPC tcon has the same lifetime as the session.
1921 */
1922 static int
cifs_setup_ipc(struct cifs_ses * ses,struct smb3_fs_context * ctx)1923 cifs_setup_ipc(struct cifs_ses *ses, struct smb3_fs_context *ctx)
1924 {
1925 int rc = 0, xid;
1926 struct cifs_tcon *tcon;
1927 char unc[SERVER_NAME_LENGTH + sizeof("//x/IPC$")] = {0};
1928 bool seal = false;
1929 struct TCP_Server_Info *server = ses->server;
1930
1931 /*
1932 * If the mount request that resulted in the creation of the
1933 * session requires encryption, force IPC to be encrypted too.
1934 */
1935 if (ctx->seal) {
1936 if (server->capabilities & SMB2_GLOBAL_CAP_ENCRYPTION)
1937 seal = true;
1938 else {
1939 cifs_server_dbg(VFS,
1940 "IPC: server doesn't support encryption\n");
1941 return -EOPNOTSUPP;
1942 }
1943 }
1944
1945 /* no need to setup directory caching on IPC share, so pass in false */
1946 tcon = tcon_info_alloc(false, netfs_trace_tcon_ref_new_ipc);
1947 if (tcon == NULL)
1948 return -ENOMEM;
1949
1950 spin_lock(&server->srv_lock);
1951 scnprintf(unc, sizeof(unc), "\\\\%s\\IPC$", server->hostname);
1952 spin_unlock(&server->srv_lock);
1953
1954 xid = get_xid();
1955 tcon->ses = ses;
1956 tcon->ipc = true;
1957 tcon->seal = seal;
1958 rc = server->ops->tree_connect(xid, ses, unc, tcon, ctx->local_nls);
1959 free_xid(xid);
1960
1961 if (rc) {
1962 cifs_server_dbg(VFS, "failed to connect to IPC (rc=%d)\n", rc);
1963 tconInfoFree(tcon, netfs_trace_tcon_ref_free_ipc_fail);
1964 goto out;
1965 }
1966
1967 cifs_dbg(FYI, "IPC tcon rc=%d ipc tid=0x%x\n", rc, tcon->tid);
1968
1969 spin_lock(&tcon->tc_lock);
1970 tcon->status = TID_GOOD;
1971 spin_unlock(&tcon->tc_lock);
1972 ses->tcon_ipc = tcon;
1973 out:
1974 return rc;
1975 }
1976
1977 static struct cifs_ses *
cifs_find_smb_ses(struct TCP_Server_Info * server,struct smb3_fs_context * ctx)1978 cifs_find_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
1979 {
1980 struct cifs_ses *ses, *ret = NULL;
1981
1982 spin_lock(&cifs_tcp_ses_lock);
1983 list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) {
1984 spin_lock(&ses->ses_lock);
1985 if (ses->ses_status == SES_EXITING) {
1986 spin_unlock(&ses->ses_lock);
1987 continue;
1988 }
1989 spin_lock(&ses->chan_lock);
1990 if (match_session(ses, ctx, false)) {
1991 spin_unlock(&ses->chan_lock);
1992 spin_unlock(&ses->ses_lock);
1993 ret = ses;
1994 break;
1995 }
1996 spin_unlock(&ses->chan_lock);
1997 spin_unlock(&ses->ses_lock);
1998 }
1999 if (ret)
2000 cifs_smb_ses_inc_refcount(ret);
2001 spin_unlock(&cifs_tcp_ses_lock);
2002 return ret;
2003 }
2004
__cifs_put_smb_ses(struct cifs_ses * ses)2005 void __cifs_put_smb_ses(struct cifs_ses *ses)
2006 {
2007 struct TCP_Server_Info *server = ses->server;
2008 struct cifs_tcon *tcon;
2009 unsigned int xid;
2010 size_t i;
2011 bool do_logoff;
2012 int rc;
2013
2014 spin_lock(&cifs_tcp_ses_lock);
2015 spin_lock(&ses->ses_lock);
2016 cifs_dbg(FYI, "%s: id=0x%llx ses_count=%d ses_status=%u ipc=%s\n",
2017 __func__, ses->Suid, ses->ses_count, ses->ses_status,
2018 ses->tcon_ipc ? ses->tcon_ipc->tree_name : "none");
2019 if (ses->ses_status == SES_EXITING || --ses->ses_count > 0) {
2020 spin_unlock(&ses->ses_lock);
2021 spin_unlock(&cifs_tcp_ses_lock);
2022 return;
2023 }
2024 /* ses_count can never go negative */
2025 WARN_ON(ses->ses_count < 0);
2026
2027 spin_lock(&ses->chan_lock);
2028 cifs_chan_clear_need_reconnect(ses, server);
2029 spin_unlock(&ses->chan_lock);
2030
2031 do_logoff = ses->ses_status == SES_GOOD && server->ops->logoff;
2032 ses->ses_status = SES_EXITING;
2033 tcon = ses->tcon_ipc;
2034 ses->tcon_ipc = NULL;
2035 spin_unlock(&ses->ses_lock);
2036 spin_unlock(&cifs_tcp_ses_lock);
2037
2038 /*
2039 * On session close, the IPC is closed and the server must release all
2040 * tcons of the session. No need to send a tree disconnect here.
2041 *
2042 * Besides, it will make the server to not close durable and resilient
2043 * files on session close, as specified in MS-SMB2 3.3.5.6 Receiving an
2044 * SMB2 LOGOFF Request.
2045 */
2046 tconInfoFree(tcon, netfs_trace_tcon_ref_free_ipc);
2047 if (do_logoff) {
2048 xid = get_xid();
2049 rc = server->ops->logoff(xid, ses);
2050 cifs_server_dbg(FYI, "%s: Session Logoff: rc=%d\n",
2051 __func__, rc);
2052 _free_xid(xid);
2053 }
2054
2055 spin_lock(&cifs_tcp_ses_lock);
2056 list_del_init(&ses->smb_ses_list);
2057 spin_unlock(&cifs_tcp_ses_lock);
2058
2059 /* close any extra channels */
2060 for (i = 1; i < ses->chan_count; i++) {
2061 if (ses->chans[i].iface) {
2062 kref_put(&ses->chans[i].iface->refcount, release_iface);
2063 ses->chans[i].iface = NULL;
2064 }
2065 cifs_put_tcp_session(ses->chans[i].server, 0);
2066 ses->chans[i].server = NULL;
2067 }
2068
2069 /* we now account for primary channel in iface->refcount */
2070 if (ses->chans[0].iface) {
2071 kref_put(&ses->chans[0].iface->refcount, release_iface);
2072 ses->chans[0].server = NULL;
2073 }
2074
2075 sesInfoFree(ses);
2076 cifs_put_tcp_session(server, 0);
2077 }
2078
2079 #ifdef CONFIG_KEYS
2080
2081 /* strlen("cifs:a:") + CIFS_MAX_DOMAINNAME_LEN + 1 */
2082 #define CIFSCREDS_DESC_SIZE (7 + CIFS_MAX_DOMAINNAME_LEN + 1)
2083
2084 /* Populate username and pw fields from keyring if possible */
2085 static int
cifs_set_cifscreds(struct smb3_fs_context * ctx,struct cifs_ses * ses)2086 cifs_set_cifscreds(struct smb3_fs_context *ctx, struct cifs_ses *ses)
2087 {
2088 int rc = 0;
2089 int is_domain = 0;
2090 const char *delim, *payload;
2091 char *desc;
2092 ssize_t len;
2093 struct key *key;
2094 struct TCP_Server_Info *server = ses->server;
2095 struct sockaddr_in *sa;
2096 struct sockaddr_in6 *sa6;
2097 const struct user_key_payload *upayload;
2098
2099 desc = kmalloc(CIFSCREDS_DESC_SIZE, GFP_KERNEL);
2100 if (!desc)
2101 return -ENOMEM;
2102
2103 /* try to find an address key first */
2104 switch (server->dstaddr.ss_family) {
2105 case AF_INET:
2106 sa = (struct sockaddr_in *)&server->dstaddr;
2107 sprintf(desc, "cifs:a:%pI4", &sa->sin_addr.s_addr);
2108 break;
2109 case AF_INET6:
2110 sa6 = (struct sockaddr_in6 *)&server->dstaddr;
2111 sprintf(desc, "cifs:a:%pI6c", &sa6->sin6_addr.s6_addr);
2112 break;
2113 default:
2114 cifs_dbg(FYI, "Bad ss_family (%hu)\n",
2115 server->dstaddr.ss_family);
2116 rc = -EINVAL;
2117 goto out_err;
2118 }
2119
2120 cifs_dbg(FYI, "%s: desc=%s\n", __func__, desc);
2121 key = request_key(&key_type_logon, desc, "");
2122 if (IS_ERR(key)) {
2123 if (!ses->domainName) {
2124 cifs_dbg(FYI, "domainName is NULL\n");
2125 rc = PTR_ERR(key);
2126 goto out_err;
2127 }
2128
2129 /* didn't work, try to find a domain key */
2130 sprintf(desc, "cifs:d:%s", ses->domainName);
2131 cifs_dbg(FYI, "%s: desc=%s\n", __func__, desc);
2132 key = request_key(&key_type_logon, desc, "");
2133 if (IS_ERR(key)) {
2134 rc = PTR_ERR(key);
2135 goto out_err;
2136 }
2137 is_domain = 1;
2138 }
2139
2140 down_read(&key->sem);
2141 upayload = user_key_payload_locked(key);
2142 if (IS_ERR_OR_NULL(upayload)) {
2143 rc = upayload ? PTR_ERR(upayload) : -EINVAL;
2144 goto out_key_put;
2145 }
2146
2147 /* find first : in payload */
2148 payload = upayload->data;
2149 delim = strnchr(payload, upayload->datalen, ':');
2150 cifs_dbg(FYI, "payload=%s\n", payload);
2151 if (!delim) {
2152 cifs_dbg(FYI, "Unable to find ':' in payload (datalen=%d)\n",
2153 upayload->datalen);
2154 rc = -EINVAL;
2155 goto out_key_put;
2156 }
2157
2158 len = delim - payload;
2159 if (len > CIFS_MAX_USERNAME_LEN || len <= 0) {
2160 cifs_dbg(FYI, "Bad value from username search (len=%zd)\n",
2161 len);
2162 rc = -EINVAL;
2163 goto out_key_put;
2164 }
2165
2166 ctx->username = kstrndup(payload, len, GFP_KERNEL);
2167 if (!ctx->username) {
2168 cifs_dbg(FYI, "Unable to allocate %zd bytes for username\n",
2169 len);
2170 rc = -ENOMEM;
2171 goto out_key_put;
2172 }
2173 cifs_dbg(FYI, "%s: username=%s\n", __func__, ctx->username);
2174
2175 len = key->datalen - (len + 1);
2176 if (len > CIFS_MAX_PASSWORD_LEN || len <= 0) {
2177 cifs_dbg(FYI, "Bad len for password search (len=%zd)\n", len);
2178 rc = -EINVAL;
2179 kfree(ctx->username);
2180 ctx->username = NULL;
2181 goto out_key_put;
2182 }
2183
2184 ++delim;
2185 /* BB consider adding support for password2 (Key Rotation) for multiuser in future */
2186 ctx->password = kstrndup(delim, len, GFP_KERNEL);
2187 if (!ctx->password) {
2188 cifs_dbg(FYI, "Unable to allocate %zd bytes for password\n",
2189 len);
2190 rc = -ENOMEM;
2191 kfree(ctx->username);
2192 ctx->username = NULL;
2193 goto out_key_put;
2194 }
2195
2196 /*
2197 * If we have a domain key then we must set the domainName in the
2198 * for the request.
2199 */
2200 if (is_domain && ses->domainName) {
2201 ctx->domainname = kstrdup(ses->domainName, GFP_KERNEL);
2202 if (!ctx->domainname) {
2203 cifs_dbg(FYI, "Unable to allocate %zd bytes for domain\n",
2204 len);
2205 rc = -ENOMEM;
2206 kfree(ctx->username);
2207 ctx->username = NULL;
2208 kfree_sensitive(ctx->password);
2209 /* no need to free ctx->password2 since not allocated in this path */
2210 ctx->password = NULL;
2211 goto out_key_put;
2212 }
2213 }
2214
2215 strscpy(ctx->workstation_name, ses->workstation_name, sizeof(ctx->workstation_name));
2216
2217 out_key_put:
2218 up_read(&key->sem);
2219 key_put(key);
2220 out_err:
2221 kfree(desc);
2222 cifs_dbg(FYI, "%s: returning %d\n", __func__, rc);
2223 return rc;
2224 }
2225 #else /* ! CONFIG_KEYS */
2226 static inline int
cifs_set_cifscreds(struct smb3_fs_context * ctx,struct cifs_ses * ses)2227 cifs_set_cifscreds(struct smb3_fs_context *ctx __attribute__((unused)),
2228 struct cifs_ses *ses __attribute__((unused)))
2229 {
2230 return -ENOSYS;
2231 }
2232 #endif /* CONFIG_KEYS */
2233
2234 /**
2235 * cifs_get_smb_ses - get a session matching @ctx data from @server
2236 * @server: server to setup the session to
2237 * @ctx: superblock configuration context to use to setup the session
2238 *
2239 * This function assumes it is being called from cifs_mount() where we
2240 * already got a server reference (server refcount +1). See
2241 * cifs_get_tcon() for refcount explanations.
2242 */
2243 struct cifs_ses *
cifs_get_smb_ses(struct TCP_Server_Info * server,struct smb3_fs_context * ctx)2244 cifs_get_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
2245 {
2246 int rc = 0;
2247 unsigned int xid;
2248 struct cifs_ses *ses;
2249 struct sockaddr_in *addr = (struct sockaddr_in *)&server->dstaddr;
2250 struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&server->dstaddr;
2251
2252 xid = get_xid();
2253
2254 ses = cifs_find_smb_ses(server, ctx);
2255 if (ses) {
2256 cifs_dbg(FYI, "Existing smb sess found (status=%d)\n",
2257 ses->ses_status);
2258
2259 spin_lock(&ses->chan_lock);
2260 if (cifs_chan_needs_reconnect(ses, server)) {
2261 spin_unlock(&ses->chan_lock);
2262 cifs_dbg(FYI, "Session needs reconnect\n");
2263
2264 mutex_lock(&ses->session_mutex);
2265 rc = cifs_negotiate_protocol(xid, ses, server);
2266 if (rc) {
2267 mutex_unlock(&ses->session_mutex);
2268 /* problem -- put our ses reference */
2269 cifs_put_smb_ses(ses);
2270 free_xid(xid);
2271 return ERR_PTR(rc);
2272 }
2273
2274 rc = cifs_setup_session(xid, ses, server,
2275 ctx->local_nls);
2276 if (rc) {
2277 mutex_unlock(&ses->session_mutex);
2278 /* problem -- put our reference */
2279 cifs_put_smb_ses(ses);
2280 free_xid(xid);
2281 return ERR_PTR(rc);
2282 }
2283 mutex_unlock(&ses->session_mutex);
2284
2285 spin_lock(&ses->chan_lock);
2286 }
2287 spin_unlock(&ses->chan_lock);
2288
2289 /* existing SMB ses has a server reference already */
2290 cifs_put_tcp_session(server, 0);
2291 free_xid(xid);
2292 return ses;
2293 }
2294
2295 rc = -ENOMEM;
2296
2297 cifs_dbg(FYI, "Existing smb sess not found\n");
2298 ses = sesInfoAlloc();
2299 if (ses == NULL)
2300 goto get_ses_fail;
2301
2302 /* new SMB session uses our server ref */
2303 ses->server = server;
2304 if (server->dstaddr.ss_family == AF_INET6)
2305 sprintf(ses->ip_addr, "%pI6", &addr6->sin6_addr);
2306 else
2307 sprintf(ses->ip_addr, "%pI4", &addr->sin_addr);
2308
2309 if (ctx->username) {
2310 ses->user_name = kstrdup(ctx->username, GFP_KERNEL);
2311 if (!ses->user_name)
2312 goto get_ses_fail;
2313 }
2314
2315 /* ctx->password freed at unmount */
2316 if (ctx->password) {
2317 ses->password = kstrdup(ctx->password, GFP_KERNEL);
2318 if (!ses->password)
2319 goto get_ses_fail;
2320 }
2321 /* ctx->password freed at unmount */
2322 if (ctx->password2) {
2323 ses->password2 = kstrdup(ctx->password2, GFP_KERNEL);
2324 if (!ses->password2)
2325 goto get_ses_fail;
2326 }
2327 if (ctx->domainname) {
2328 ses->domainName = kstrdup(ctx->domainname, GFP_KERNEL);
2329 if (!ses->domainName)
2330 goto get_ses_fail;
2331 }
2332
2333 strscpy(ses->workstation_name, ctx->workstation_name, sizeof(ses->workstation_name));
2334
2335 if (ctx->domainauto)
2336 ses->domainAuto = ctx->domainauto;
2337 ses->cred_uid = ctx->cred_uid;
2338 ses->linux_uid = ctx->linux_uid;
2339
2340 ses->sectype = ctx->sectype;
2341 ses->sign = ctx->sign;
2342 ses->local_nls = load_nls(ctx->local_nls->charset);
2343
2344 /* add server as first channel */
2345 spin_lock(&ses->chan_lock);
2346 ses->chans[0].server = server;
2347 ses->chan_count = 1;
2348 ses->chan_max = ctx->multichannel ? ctx->max_channels:1;
2349 ses->chans_need_reconnect = 1;
2350 spin_unlock(&ses->chan_lock);
2351
2352 mutex_lock(&ses->session_mutex);
2353 rc = cifs_negotiate_protocol(xid, ses, server);
2354 if (!rc)
2355 rc = cifs_setup_session(xid, ses, server, ctx->local_nls);
2356 mutex_unlock(&ses->session_mutex);
2357
2358 /* each channel uses a different signing key */
2359 spin_lock(&ses->chan_lock);
2360 memcpy(ses->chans[0].signkey, ses->smb3signingkey,
2361 sizeof(ses->smb3signingkey));
2362 spin_unlock(&ses->chan_lock);
2363
2364 if (rc)
2365 goto get_ses_fail;
2366
2367 /*
2368 * success, put it on the list and add it as first channel
2369 * note: the session becomes active soon after this. So you'll
2370 * need to lock before changing something in the session.
2371 */
2372 spin_lock(&cifs_tcp_ses_lock);
2373 ses->dfs_root_ses = ctx->dfs_root_ses;
2374 list_add(&ses->smb_ses_list, &server->smb_ses_list);
2375 spin_unlock(&cifs_tcp_ses_lock);
2376
2377 cifs_setup_ipc(ses, ctx);
2378
2379 free_xid(xid);
2380
2381 return ses;
2382
2383 get_ses_fail:
2384 sesInfoFree(ses);
2385 free_xid(xid);
2386 return ERR_PTR(rc);
2387 }
2388
2389 /* this function must be called with tc_lock held */
match_tcon(struct cifs_tcon * tcon,struct smb3_fs_context * ctx)2390 static int match_tcon(struct cifs_tcon *tcon, struct smb3_fs_context *ctx)
2391 {
2392 struct TCP_Server_Info *server = tcon->ses->server;
2393
2394 if (tcon->status == TID_EXITING)
2395 return 0;
2396
2397 if (tcon->origin_fullpath) {
2398 if (!ctx->source ||
2399 !dfs_src_pathname_equal(ctx->source,
2400 tcon->origin_fullpath))
2401 return 0;
2402 } else if (!server->leaf_fullpath &&
2403 strncmp(tcon->tree_name, ctx->UNC, MAX_TREE_SIZE)) {
2404 return 0;
2405 }
2406 if (tcon->seal != ctx->seal)
2407 return 0;
2408 if (tcon->snapshot_time != ctx->snapshot_time)
2409 return 0;
2410 if (tcon->handle_timeout != ctx->handle_timeout)
2411 return 0;
2412 if (tcon->no_lease != ctx->no_lease)
2413 return 0;
2414 if (tcon->nodelete != ctx->nodelete)
2415 return 0;
2416 return 1;
2417 }
2418
2419 static struct cifs_tcon *
cifs_find_tcon(struct cifs_ses * ses,struct smb3_fs_context * ctx)2420 cifs_find_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx)
2421 {
2422 struct cifs_tcon *tcon;
2423
2424 spin_lock(&cifs_tcp_ses_lock);
2425 list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
2426 spin_lock(&tcon->tc_lock);
2427 if (!match_tcon(tcon, ctx)) {
2428 spin_unlock(&tcon->tc_lock);
2429 continue;
2430 }
2431 ++tcon->tc_count;
2432 trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count,
2433 netfs_trace_tcon_ref_get_find);
2434 spin_unlock(&tcon->tc_lock);
2435 spin_unlock(&cifs_tcp_ses_lock);
2436 return tcon;
2437 }
2438 spin_unlock(&cifs_tcp_ses_lock);
2439 return NULL;
2440 }
2441
2442 void
cifs_put_tcon(struct cifs_tcon * tcon,enum smb3_tcon_ref_trace trace)2443 cifs_put_tcon(struct cifs_tcon *tcon, enum smb3_tcon_ref_trace trace)
2444 {
2445 unsigned int xid;
2446 struct cifs_ses *ses;
2447 LIST_HEAD(ses_list);
2448
2449 /*
2450 * IPC tcon share the lifetime of their session and are
2451 * destroyed in the session put function
2452 */
2453 if (tcon == NULL || tcon->ipc)
2454 return;
2455
2456 ses = tcon->ses;
2457 cifs_dbg(FYI, "%s: tc_count=%d\n", __func__, tcon->tc_count);
2458 spin_lock(&cifs_tcp_ses_lock);
2459 spin_lock(&tcon->tc_lock);
2460 trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count - 1, trace);
2461 if (--tcon->tc_count > 0) {
2462 spin_unlock(&tcon->tc_lock);
2463 spin_unlock(&cifs_tcp_ses_lock);
2464 return;
2465 }
2466
2467 /* tc_count can never go negative */
2468 WARN_ON(tcon->tc_count < 0);
2469
2470 list_del_init(&tcon->tcon_list);
2471 tcon->status = TID_EXITING;
2472 #ifdef CONFIG_CIFS_DFS_UPCALL
2473 list_replace_init(&tcon->dfs_ses_list, &ses_list);
2474 #endif
2475 spin_unlock(&tcon->tc_lock);
2476 spin_unlock(&cifs_tcp_ses_lock);
2477
2478 /* cancel polling of interfaces */
2479 cancel_delayed_work_sync(&tcon->query_interfaces);
2480 #ifdef CONFIG_CIFS_DFS_UPCALL
2481 cancel_delayed_work_sync(&tcon->dfs_cache_work);
2482 #endif
2483
2484 if (tcon->use_witness) {
2485 int rc;
2486
2487 rc = cifs_swn_unregister(tcon);
2488 if (rc < 0) {
2489 cifs_dbg(VFS, "%s: Failed to unregister for witness notifications: %d\n",
2490 __func__, rc);
2491 }
2492 }
2493
2494 xid = get_xid();
2495 if (ses->server->ops->tree_disconnect)
2496 ses->server->ops->tree_disconnect(xid, tcon);
2497 _free_xid(xid);
2498
2499 cifs_fscache_release_super_cookie(tcon);
2500 tconInfoFree(tcon, netfs_trace_tcon_ref_free);
2501 cifs_put_smb_ses(ses);
2502 #ifdef CONFIG_CIFS_DFS_UPCALL
2503 dfs_put_root_smb_sessions(&ses_list);
2504 #endif
2505 }
2506
2507 /**
2508 * cifs_get_tcon - get a tcon matching @ctx data from @ses
2509 * @ses: smb session to issue the request on
2510 * @ctx: the superblock configuration context to use for building the
2511 *
2512 * - tcon refcount is the number of mount points using the tcon.
2513 * - ses refcount is the number of tcon using the session.
2514 *
2515 * 1. This function assumes it is being called from cifs_mount() where
2516 * we already got a session reference (ses refcount +1).
2517 *
2518 * 2. Since we're in the context of adding a mount point, the end
2519 * result should be either:
2520 *
2521 * a) a new tcon already allocated with refcount=1 (1 mount point) and
2522 * its session refcount incremented (1 new tcon). This +1 was
2523 * already done in (1).
2524 *
2525 * b) an existing tcon with refcount+1 (add a mount point to it) and
2526 * identical ses refcount (no new tcon). Because of (1) we need to
2527 * decrement the ses refcount.
2528 */
2529 static struct cifs_tcon *
cifs_get_tcon(struct cifs_ses * ses,struct smb3_fs_context * ctx)2530 cifs_get_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx)
2531 {
2532 struct cifs_tcon *tcon;
2533 bool nohandlecache;
2534 int rc, xid;
2535
2536 tcon = cifs_find_tcon(ses, ctx);
2537 if (tcon) {
2538 /*
2539 * tcon has refcount already incremented but we need to
2540 * decrement extra ses reference gotten by caller (case b)
2541 */
2542 cifs_dbg(FYI, "Found match on UNC path\n");
2543 cifs_put_smb_ses(ses);
2544 return tcon;
2545 }
2546
2547 if (!ses->server->ops->tree_connect) {
2548 rc = -ENOSYS;
2549 goto out_fail;
2550 }
2551
2552 if (ses->server->dialect >= SMB20_PROT_ID &&
2553 (ses->server->capabilities & SMB2_GLOBAL_CAP_DIRECTORY_LEASING))
2554 nohandlecache = ctx->nohandlecache;
2555 else
2556 nohandlecache = true;
2557 tcon = tcon_info_alloc(!nohandlecache, netfs_trace_tcon_ref_new);
2558 if (tcon == NULL) {
2559 rc = -ENOMEM;
2560 goto out_fail;
2561 }
2562 tcon->nohandlecache = nohandlecache;
2563
2564 if (ctx->snapshot_time) {
2565 if (ses->server->vals->protocol_id == 0) {
2566 cifs_dbg(VFS,
2567 "Use SMB2 or later for snapshot mount option\n");
2568 rc = -EOPNOTSUPP;
2569 goto out_fail;
2570 } else
2571 tcon->snapshot_time = ctx->snapshot_time;
2572 }
2573
2574 if (ctx->handle_timeout) {
2575 if (ses->server->vals->protocol_id == 0) {
2576 cifs_dbg(VFS,
2577 "Use SMB2.1 or later for handle timeout option\n");
2578 rc = -EOPNOTSUPP;
2579 goto out_fail;
2580 } else
2581 tcon->handle_timeout = ctx->handle_timeout;
2582 }
2583
2584 tcon->ses = ses;
2585 if (ctx->password) {
2586 tcon->password = kstrdup(ctx->password, GFP_KERNEL);
2587 if (!tcon->password) {
2588 rc = -ENOMEM;
2589 goto out_fail;
2590 }
2591 }
2592
2593 if (ctx->seal) {
2594 if (ses->server->vals->protocol_id == 0) {
2595 cifs_dbg(VFS,
2596 "SMB3 or later required for encryption\n");
2597 rc = -EOPNOTSUPP;
2598 goto out_fail;
2599 } else if (tcon->ses->server->capabilities &
2600 SMB2_GLOBAL_CAP_ENCRYPTION)
2601 tcon->seal = true;
2602 else {
2603 cifs_dbg(VFS, "Encryption is not supported on share\n");
2604 rc = -EOPNOTSUPP;
2605 goto out_fail;
2606 }
2607 }
2608
2609 if (ctx->linux_ext) {
2610 if (ses->server->posix_ext_supported) {
2611 tcon->posix_extensions = true;
2612 pr_warn_once("SMB3.11 POSIX Extensions are experimental\n");
2613 } else if ((ses->server->vals->protocol_id == SMB311_PROT_ID) ||
2614 (strcmp(ses->server->vals->version_string,
2615 SMB3ANY_VERSION_STRING) == 0) ||
2616 (strcmp(ses->server->vals->version_string,
2617 SMBDEFAULT_VERSION_STRING) == 0)) {
2618 cifs_dbg(VFS, "Server does not support mounting with posix SMB3.11 extensions\n");
2619 rc = -EOPNOTSUPP;
2620 goto out_fail;
2621 } else if (ses->server->vals->protocol_id == SMB10_PROT_ID)
2622 if (cap_unix(ses))
2623 cifs_dbg(FYI, "Unix Extensions requested on SMB1 mount\n");
2624 else {
2625 cifs_dbg(VFS, "SMB1 Unix Extensions not supported by server\n");
2626 rc = -EOPNOTSUPP;
2627 goto out_fail;
2628 } else {
2629 cifs_dbg(VFS,
2630 "Check vers= mount option. SMB3.11 disabled but required for POSIX extensions\n");
2631 rc = -EOPNOTSUPP;
2632 goto out_fail;
2633 }
2634 }
2635
2636 xid = get_xid();
2637 rc = ses->server->ops->tree_connect(xid, ses, ctx->UNC, tcon,
2638 ctx->local_nls);
2639 free_xid(xid);
2640 cifs_dbg(FYI, "Tcon rc = %d\n", rc);
2641 if (rc)
2642 goto out_fail;
2643
2644 tcon->use_persistent = false;
2645 /* check if SMB2 or later, CIFS does not support persistent handles */
2646 if (ctx->persistent) {
2647 if (ses->server->vals->protocol_id == 0) {
2648 cifs_dbg(VFS,
2649 "SMB3 or later required for persistent handles\n");
2650 rc = -EOPNOTSUPP;
2651 goto out_fail;
2652 } else if (ses->server->capabilities &
2653 SMB2_GLOBAL_CAP_PERSISTENT_HANDLES)
2654 tcon->use_persistent = true;
2655 else /* persistent handles requested but not supported */ {
2656 cifs_dbg(VFS,
2657 "Persistent handles not supported on share\n");
2658 rc = -EOPNOTSUPP;
2659 goto out_fail;
2660 }
2661 } else if ((tcon->capabilities & SMB2_SHARE_CAP_CONTINUOUS_AVAILABILITY)
2662 && (ses->server->capabilities & SMB2_GLOBAL_CAP_PERSISTENT_HANDLES)
2663 && (ctx->nopersistent == false)) {
2664 cifs_dbg(FYI, "enabling persistent handles\n");
2665 tcon->use_persistent = true;
2666 } else if (ctx->resilient) {
2667 if (ses->server->vals->protocol_id == 0) {
2668 cifs_dbg(VFS,
2669 "SMB2.1 or later required for resilient handles\n");
2670 rc = -EOPNOTSUPP;
2671 goto out_fail;
2672 }
2673 tcon->use_resilient = true;
2674 }
2675
2676 tcon->use_witness = false;
2677 if (IS_ENABLED(CONFIG_CIFS_SWN_UPCALL) && ctx->witness) {
2678 if (ses->server->vals->protocol_id >= SMB30_PROT_ID) {
2679 if (tcon->capabilities & SMB2_SHARE_CAP_CLUSTER) {
2680 /*
2681 * Set witness in use flag in first place
2682 * to retry registration in the echo task
2683 */
2684 tcon->use_witness = true;
2685 /* And try to register immediately */
2686 rc = cifs_swn_register(tcon);
2687 if (rc < 0) {
2688 cifs_dbg(VFS, "Failed to register for witness notifications: %d\n", rc);
2689 goto out_fail;
2690 }
2691 } else {
2692 /* TODO: try to extend for non-cluster uses (eg multichannel) */
2693 cifs_dbg(VFS, "witness requested on mount but no CLUSTER capability on share\n");
2694 rc = -EOPNOTSUPP;
2695 goto out_fail;
2696 }
2697 } else {
2698 cifs_dbg(VFS, "SMB3 or later required for witness option\n");
2699 rc = -EOPNOTSUPP;
2700 goto out_fail;
2701 }
2702 }
2703
2704 /* If the user really knows what they are doing they can override */
2705 if (tcon->share_flags & SMB2_SHAREFLAG_NO_CACHING) {
2706 if (ctx->cache_ro)
2707 cifs_dbg(VFS, "cache=ro requested on mount but NO_CACHING flag set on share\n");
2708 else if (ctx->cache_rw)
2709 cifs_dbg(VFS, "cache=singleclient requested on mount but NO_CACHING flag set on share\n");
2710 }
2711
2712 if (ctx->no_lease) {
2713 if (ses->server->vals->protocol_id == 0) {
2714 cifs_dbg(VFS,
2715 "SMB2 or later required for nolease option\n");
2716 rc = -EOPNOTSUPP;
2717 goto out_fail;
2718 } else
2719 tcon->no_lease = ctx->no_lease;
2720 }
2721
2722 /*
2723 * We can have only one retry value for a connection to a share so for
2724 * resources mounted more than once to the same server share the last
2725 * value passed in for the retry flag is used.
2726 */
2727 tcon->retry = ctx->retry;
2728 tcon->nocase = ctx->nocase;
2729 tcon->broken_sparse_sup = ctx->no_sparse;
2730 tcon->max_cached_dirs = ctx->max_cached_dirs;
2731 tcon->nodelete = ctx->nodelete;
2732 tcon->local_lease = ctx->local_lease;
2733 INIT_LIST_HEAD(&tcon->pending_opens);
2734 tcon->status = TID_GOOD;
2735
2736 INIT_DELAYED_WORK(&tcon->query_interfaces,
2737 smb2_query_server_interfaces);
2738 if (ses->server->dialect >= SMB30_PROT_ID &&
2739 (ses->server->capabilities & SMB2_GLOBAL_CAP_MULTI_CHANNEL)) {
2740 /* schedule query interfaces poll */
2741 queue_delayed_work(cifsiod_wq, &tcon->query_interfaces,
2742 (SMB_INTERFACE_POLL_INTERVAL * HZ));
2743 }
2744 #ifdef CONFIG_CIFS_DFS_UPCALL
2745 INIT_DELAYED_WORK(&tcon->dfs_cache_work, dfs_cache_refresh);
2746 #endif
2747 spin_lock(&cifs_tcp_ses_lock);
2748 list_add(&tcon->tcon_list, &ses->tcon_list);
2749 spin_unlock(&cifs_tcp_ses_lock);
2750
2751 return tcon;
2752
2753 out_fail:
2754 tconInfoFree(tcon, netfs_trace_tcon_ref_free_fail);
2755 return ERR_PTR(rc);
2756 }
2757
2758 void
cifs_put_tlink(struct tcon_link * tlink)2759 cifs_put_tlink(struct tcon_link *tlink)
2760 {
2761 if (!tlink || IS_ERR(tlink))
2762 return;
2763
2764 if (!atomic_dec_and_test(&tlink->tl_count) ||
2765 test_bit(TCON_LINK_IN_TREE, &tlink->tl_flags)) {
2766 tlink->tl_time = jiffies;
2767 return;
2768 }
2769
2770 if (!IS_ERR(tlink_tcon(tlink)))
2771 cifs_put_tcon(tlink_tcon(tlink), netfs_trace_tcon_ref_put_tlink);
2772 kfree(tlink);
2773 }
2774
2775 static int
compare_mount_options(struct super_block * sb,struct cifs_mnt_data * mnt_data)2776 compare_mount_options(struct super_block *sb, struct cifs_mnt_data *mnt_data)
2777 {
2778 struct cifs_sb_info *old = CIFS_SB(sb);
2779 struct cifs_sb_info *new = mnt_data->cifs_sb;
2780 unsigned int oldflags = old->mnt_cifs_flags & CIFS_MOUNT_MASK;
2781 unsigned int newflags = new->mnt_cifs_flags & CIFS_MOUNT_MASK;
2782
2783 if ((sb->s_flags & CIFS_MS_MASK) != (mnt_data->flags & CIFS_MS_MASK))
2784 return 0;
2785
2786 if (old->mnt_cifs_serverino_autodisabled)
2787 newflags &= ~CIFS_MOUNT_SERVER_INUM;
2788
2789 if (oldflags != newflags)
2790 return 0;
2791
2792 /*
2793 * We want to share sb only if we don't specify an r/wsize or
2794 * specified r/wsize is greater than or equal to existing one.
2795 */
2796 if (new->ctx->wsize && new->ctx->wsize < old->ctx->wsize)
2797 return 0;
2798
2799 if (new->ctx->rsize && new->ctx->rsize < old->ctx->rsize)
2800 return 0;
2801
2802 if (!uid_eq(old->ctx->linux_uid, new->ctx->linux_uid) ||
2803 !gid_eq(old->ctx->linux_gid, new->ctx->linux_gid))
2804 return 0;
2805
2806 if (old->ctx->file_mode != new->ctx->file_mode ||
2807 old->ctx->dir_mode != new->ctx->dir_mode)
2808 return 0;
2809
2810 if (strcmp(old->local_nls->charset, new->local_nls->charset))
2811 return 0;
2812
2813 if (old->ctx->acregmax != new->ctx->acregmax)
2814 return 0;
2815 if (old->ctx->acdirmax != new->ctx->acdirmax)
2816 return 0;
2817 if (old->ctx->closetimeo != new->ctx->closetimeo)
2818 return 0;
2819 if (old->ctx->reparse_type != new->ctx->reparse_type)
2820 return 0;
2821
2822 return 1;
2823 }
2824
match_prepath(struct super_block * sb,struct cifs_tcon * tcon,struct cifs_mnt_data * mnt_data)2825 static int match_prepath(struct super_block *sb,
2826 struct cifs_tcon *tcon,
2827 struct cifs_mnt_data *mnt_data)
2828 {
2829 struct smb3_fs_context *ctx = mnt_data->ctx;
2830 struct cifs_sb_info *old = CIFS_SB(sb);
2831 struct cifs_sb_info *new = mnt_data->cifs_sb;
2832 bool old_set = (old->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH) &&
2833 old->prepath;
2834 bool new_set = (new->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH) &&
2835 new->prepath;
2836
2837 if (tcon->origin_fullpath &&
2838 dfs_src_pathname_equal(tcon->origin_fullpath, ctx->source))
2839 return 1;
2840
2841 if (old_set && new_set && !strcmp(new->prepath, old->prepath))
2842 return 1;
2843 else if (!old_set && !new_set)
2844 return 1;
2845
2846 return 0;
2847 }
2848
2849 int
cifs_match_super(struct super_block * sb,void * data)2850 cifs_match_super(struct super_block *sb, void *data)
2851 {
2852 struct cifs_mnt_data *mnt_data = data;
2853 struct smb3_fs_context *ctx;
2854 struct cifs_sb_info *cifs_sb;
2855 struct TCP_Server_Info *tcp_srv;
2856 struct cifs_ses *ses;
2857 struct cifs_tcon *tcon;
2858 struct tcon_link *tlink;
2859 int rc = 0;
2860
2861 spin_lock(&cifs_tcp_ses_lock);
2862 cifs_sb = CIFS_SB(sb);
2863
2864 /* We do not want to use a superblock that has been shutdown */
2865 if (CIFS_MOUNT_SHUTDOWN & cifs_sb->mnt_cifs_flags) {
2866 spin_unlock(&cifs_tcp_ses_lock);
2867 return 0;
2868 }
2869
2870 tlink = cifs_get_tlink(cifs_sb_master_tlink(cifs_sb));
2871 if (IS_ERR_OR_NULL(tlink)) {
2872 pr_warn_once("%s: skip super matching due to bad tlink(%p)\n",
2873 __func__, tlink);
2874 spin_unlock(&cifs_tcp_ses_lock);
2875 return 0;
2876 }
2877 tcon = tlink_tcon(tlink);
2878 ses = tcon->ses;
2879 tcp_srv = ses->server;
2880
2881 ctx = mnt_data->ctx;
2882
2883 spin_lock(&tcp_srv->srv_lock);
2884 spin_lock(&ses->ses_lock);
2885 spin_lock(&ses->chan_lock);
2886 spin_lock(&tcon->tc_lock);
2887 if (!match_server(tcp_srv, ctx, true) ||
2888 !match_session(ses, ctx, true) ||
2889 !match_tcon(tcon, ctx) ||
2890 !match_prepath(sb, tcon, mnt_data)) {
2891 rc = 0;
2892 goto out;
2893 }
2894
2895 rc = compare_mount_options(sb, mnt_data);
2896 out:
2897 spin_unlock(&tcon->tc_lock);
2898 spin_unlock(&ses->chan_lock);
2899 spin_unlock(&ses->ses_lock);
2900 spin_unlock(&tcp_srv->srv_lock);
2901
2902 spin_unlock(&cifs_tcp_ses_lock);
2903 cifs_put_tlink(tlink);
2904 return rc;
2905 }
2906
2907 #ifdef CONFIG_DEBUG_LOCK_ALLOC
2908 static struct lock_class_key cifs_key[2];
2909 static struct lock_class_key cifs_slock_key[2];
2910
2911 static inline void
cifs_reclassify_socket4(struct socket * sock)2912 cifs_reclassify_socket4(struct socket *sock)
2913 {
2914 struct sock *sk = sock->sk;
2915
2916 BUG_ON(!sock_allow_reclassification(sk));
2917 sock_lock_init_class_and_name(sk, "slock-AF_INET-CIFS",
2918 &cifs_slock_key[0], "sk_lock-AF_INET-CIFS", &cifs_key[0]);
2919 }
2920
2921 static inline void
cifs_reclassify_socket6(struct socket * sock)2922 cifs_reclassify_socket6(struct socket *sock)
2923 {
2924 struct sock *sk = sock->sk;
2925
2926 BUG_ON(!sock_allow_reclassification(sk));
2927 sock_lock_init_class_and_name(sk, "slock-AF_INET6-CIFS",
2928 &cifs_slock_key[1], "sk_lock-AF_INET6-CIFS", &cifs_key[1]);
2929 }
2930 #else
2931 static inline void
cifs_reclassify_socket4(struct socket * sock)2932 cifs_reclassify_socket4(struct socket *sock)
2933 {
2934 }
2935
2936 static inline void
cifs_reclassify_socket6(struct socket * sock)2937 cifs_reclassify_socket6(struct socket *sock)
2938 {
2939 }
2940 #endif
2941
2942 /* See RFC1001 section 14 on representation of Netbios names */
rfc1002mangle(char * target,char * source,unsigned int length)2943 static void rfc1002mangle(char *target, char *source, unsigned int length)
2944 {
2945 unsigned int i, j;
2946
2947 for (i = 0, j = 0; i < (length); i++) {
2948 /* mask a nibble at a time and encode */
2949 target[j] = 'A' + (0x0F & (source[i] >> 4));
2950 target[j+1] = 'A' + (0x0F & source[i]);
2951 j += 2;
2952 }
2953
2954 }
2955
2956 static int
bind_socket(struct TCP_Server_Info * server)2957 bind_socket(struct TCP_Server_Info *server)
2958 {
2959 int rc = 0;
2960
2961 if (server->srcaddr.ss_family != AF_UNSPEC) {
2962 /* Bind to the specified local IP address */
2963 struct socket *socket = server->ssocket;
2964
2965 rc = kernel_bind(socket,
2966 (struct sockaddr *) &server->srcaddr,
2967 sizeof(server->srcaddr));
2968 if (rc < 0) {
2969 struct sockaddr_in *saddr4;
2970 struct sockaddr_in6 *saddr6;
2971
2972 saddr4 = (struct sockaddr_in *)&server->srcaddr;
2973 saddr6 = (struct sockaddr_in6 *)&server->srcaddr;
2974 if (saddr6->sin6_family == AF_INET6)
2975 cifs_server_dbg(VFS, "Failed to bind to: %pI6c, error: %d\n",
2976 &saddr6->sin6_addr, rc);
2977 else
2978 cifs_server_dbg(VFS, "Failed to bind to: %pI4, error: %d\n",
2979 &saddr4->sin_addr.s_addr, rc);
2980 }
2981 }
2982 return rc;
2983 }
2984
2985 static int
ip_rfc1001_connect(struct TCP_Server_Info * server)2986 ip_rfc1001_connect(struct TCP_Server_Info *server)
2987 {
2988 int rc = 0;
2989 /*
2990 * some servers require RFC1001 sessinit before sending
2991 * negprot - BB check reconnection in case where second
2992 * sessinit is sent but no second negprot
2993 */
2994 struct rfc1002_session_packet req = {};
2995 struct smb_hdr *smb_buf = (struct smb_hdr *)&req;
2996 unsigned int len;
2997
2998 req.trailer.session_req.called_len = sizeof(req.trailer.session_req.called_name);
2999
3000 if (server->server_RFC1001_name[0] != 0)
3001 rfc1002mangle(req.trailer.session_req.called_name,
3002 server->server_RFC1001_name,
3003 RFC1001_NAME_LEN_WITH_NULL);
3004 else
3005 rfc1002mangle(req.trailer.session_req.called_name,
3006 DEFAULT_CIFS_CALLED_NAME,
3007 RFC1001_NAME_LEN_WITH_NULL);
3008
3009 req.trailer.session_req.calling_len = sizeof(req.trailer.session_req.calling_name);
3010
3011 /* calling name ends in null (byte 16) from old smb convention */
3012 if (server->workstation_RFC1001_name[0] != 0)
3013 rfc1002mangle(req.trailer.session_req.calling_name,
3014 server->workstation_RFC1001_name,
3015 RFC1001_NAME_LEN_WITH_NULL);
3016 else
3017 rfc1002mangle(req.trailer.session_req.calling_name,
3018 "LINUX_CIFS_CLNT",
3019 RFC1001_NAME_LEN_WITH_NULL);
3020
3021 /*
3022 * As per rfc1002, @len must be the number of bytes that follows the
3023 * length field of a rfc1002 session request payload.
3024 */
3025 len = sizeof(req) - offsetof(struct rfc1002_session_packet, trailer.session_req);
3026
3027 smb_buf->smb_buf_length = cpu_to_be32((RFC1002_SESSION_REQUEST << 24) | len);
3028 rc = smb_send(server, smb_buf, len);
3029 /*
3030 * RFC1001 layer in at least one server requires very short break before
3031 * negprot presumably because not expecting negprot to follow so fast.
3032 * This is a simple solution that works without complicating the code
3033 * and causes no significant slowing down on mount for everyone else
3034 */
3035 usleep_range(1000, 2000);
3036
3037 return rc;
3038 }
3039
3040 static int
generic_ip_connect(struct TCP_Server_Info * server)3041 generic_ip_connect(struct TCP_Server_Info *server)
3042 {
3043 struct sockaddr *saddr;
3044 struct socket *socket;
3045 int slen, sfamily;
3046 __be16 sport;
3047 int rc = 0;
3048
3049 saddr = (struct sockaddr *) &server->dstaddr;
3050
3051 if (server->dstaddr.ss_family == AF_INET6) {
3052 struct sockaddr_in6 *ipv6 = (struct sockaddr_in6 *)&server->dstaddr;
3053
3054 sport = ipv6->sin6_port;
3055 slen = sizeof(struct sockaddr_in6);
3056 sfamily = AF_INET6;
3057 cifs_dbg(FYI, "%s: connecting to [%pI6]:%d\n", __func__, &ipv6->sin6_addr,
3058 ntohs(sport));
3059 } else {
3060 struct sockaddr_in *ipv4 = (struct sockaddr_in *)&server->dstaddr;
3061
3062 sport = ipv4->sin_port;
3063 slen = sizeof(struct sockaddr_in);
3064 sfamily = AF_INET;
3065 cifs_dbg(FYI, "%s: connecting to %pI4:%d\n", __func__, &ipv4->sin_addr,
3066 ntohs(sport));
3067 }
3068
3069 if (server->ssocket) {
3070 socket = server->ssocket;
3071 } else {
3072 struct net *net = cifs_net_ns(server);
3073 struct sock *sk;
3074
3075 rc = __sock_create(net, sfamily, SOCK_STREAM,
3076 IPPROTO_TCP, &server->ssocket, 1);
3077 if (rc < 0) {
3078 cifs_server_dbg(VFS, "Error %d creating socket\n", rc);
3079 return rc;
3080 }
3081
3082 sk = server->ssocket->sk;
3083 __netns_tracker_free(net, &sk->ns_tracker, false);
3084 sk->sk_net_refcnt = 1;
3085 get_net_track(net, &sk->ns_tracker, GFP_KERNEL);
3086 sock_inuse_add(net, 1);
3087
3088 /* BB other socket options to set KEEPALIVE, NODELAY? */
3089 cifs_dbg(FYI, "Socket created\n");
3090 socket = server->ssocket;
3091 socket->sk->sk_allocation = GFP_NOFS;
3092 socket->sk->sk_use_task_frag = false;
3093 if (sfamily == AF_INET6)
3094 cifs_reclassify_socket6(socket);
3095 else
3096 cifs_reclassify_socket4(socket);
3097 }
3098
3099 rc = bind_socket(server);
3100 if (rc < 0)
3101 return rc;
3102
3103 /*
3104 * Eventually check for other socket options to change from
3105 * the default. sock_setsockopt not used because it expects
3106 * user space buffer
3107 */
3108 socket->sk->sk_rcvtimeo = 7 * HZ;
3109 socket->sk->sk_sndtimeo = 5 * HZ;
3110
3111 /* make the bufsizes depend on wsize/rsize and max requests */
3112 if (server->noautotune) {
3113 if (socket->sk->sk_sndbuf < (200 * 1024))
3114 socket->sk->sk_sndbuf = 200 * 1024;
3115 if (socket->sk->sk_rcvbuf < (140 * 1024))
3116 socket->sk->sk_rcvbuf = 140 * 1024;
3117 }
3118
3119 if (server->tcp_nodelay)
3120 tcp_sock_set_nodelay(socket->sk);
3121
3122 cifs_dbg(FYI, "sndbuf %d rcvbuf %d rcvtimeo 0x%lx\n",
3123 socket->sk->sk_sndbuf,
3124 socket->sk->sk_rcvbuf, socket->sk->sk_rcvtimeo);
3125
3126 rc = kernel_connect(socket, saddr, slen,
3127 server->noblockcnt ? O_NONBLOCK : 0);
3128 /*
3129 * When mounting SMB root file systems, we do not want to block in
3130 * connect. Otherwise bail out and then let cifs_reconnect() perform
3131 * reconnect failover - if possible.
3132 */
3133 if (server->noblockcnt && rc == -EINPROGRESS)
3134 rc = 0;
3135 if (rc < 0) {
3136 cifs_dbg(FYI, "Error %d connecting to server\n", rc);
3137 trace_smb3_connect_err(server->hostname, server->conn_id, &server->dstaddr, rc);
3138 sock_release(socket);
3139 server->ssocket = NULL;
3140 return rc;
3141 }
3142 trace_smb3_connect_done(server->hostname, server->conn_id, &server->dstaddr);
3143 if (sport == htons(RFC1001_PORT))
3144 rc = ip_rfc1001_connect(server);
3145
3146 return rc;
3147 }
3148
3149 static int
ip_connect(struct TCP_Server_Info * server)3150 ip_connect(struct TCP_Server_Info *server)
3151 {
3152 __be16 *sport;
3153 struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&server->dstaddr;
3154 struct sockaddr_in *addr = (struct sockaddr_in *)&server->dstaddr;
3155
3156 if (server->dstaddr.ss_family == AF_INET6)
3157 sport = &addr6->sin6_port;
3158 else
3159 sport = &addr->sin_port;
3160
3161 if (*sport == 0) {
3162 int rc;
3163
3164 /* try with 445 port at first */
3165 *sport = htons(CIFS_PORT);
3166
3167 rc = generic_ip_connect(server);
3168 if (rc >= 0)
3169 return rc;
3170
3171 /* if it failed, try with 139 port */
3172 *sport = htons(RFC1001_PORT);
3173 }
3174
3175 return generic_ip_connect(server);
3176 }
3177
3178 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
reset_cifs_unix_caps(unsigned int xid,struct cifs_tcon * tcon,struct cifs_sb_info * cifs_sb,struct smb3_fs_context * ctx)3179 void reset_cifs_unix_caps(unsigned int xid, struct cifs_tcon *tcon,
3180 struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
3181 {
3182 /*
3183 * If we are reconnecting then should we check to see if
3184 * any requested capabilities changed locally e.g. via
3185 * remount but we can not do much about it here
3186 * if they have (even if we could detect it by the following)
3187 * Perhaps we could add a backpointer to array of sb from tcon
3188 * or if we change to make all sb to same share the same
3189 * sb as NFS - then we only have one backpointer to sb.
3190 * What if we wanted to mount the server share twice once with
3191 * and once without posixacls or posix paths?
3192 */
3193 __u64 saved_cap = le64_to_cpu(tcon->fsUnixInfo.Capability);
3194
3195 if (ctx && ctx->no_linux_ext) {
3196 tcon->fsUnixInfo.Capability = 0;
3197 tcon->unix_ext = 0; /* Unix Extensions disabled */
3198 cifs_dbg(FYI, "Linux protocol extensions disabled\n");
3199 return;
3200 } else if (ctx)
3201 tcon->unix_ext = 1; /* Unix Extensions supported */
3202
3203 if (!tcon->unix_ext) {
3204 cifs_dbg(FYI, "Unix extensions disabled so not set on reconnect\n");
3205 return;
3206 }
3207
3208 if (!CIFSSMBQFSUnixInfo(xid, tcon)) {
3209 __u64 cap = le64_to_cpu(tcon->fsUnixInfo.Capability);
3210
3211 cifs_dbg(FYI, "unix caps which server supports %lld\n", cap);
3212 /*
3213 * check for reconnect case in which we do not
3214 * want to change the mount behavior if we can avoid it
3215 */
3216 if (ctx == NULL) {
3217 /*
3218 * turn off POSIX ACL and PATHNAMES if not set
3219 * originally at mount time
3220 */
3221 if ((saved_cap & CIFS_UNIX_POSIX_ACL_CAP) == 0)
3222 cap &= ~CIFS_UNIX_POSIX_ACL_CAP;
3223 if ((saved_cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) == 0) {
3224 if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP)
3225 cifs_dbg(VFS, "POSIXPATH support change\n");
3226 cap &= ~CIFS_UNIX_POSIX_PATHNAMES_CAP;
3227 } else if ((cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) == 0) {
3228 cifs_dbg(VFS, "possible reconnect error\n");
3229 cifs_dbg(VFS, "server disabled POSIX path support\n");
3230 }
3231 }
3232
3233 if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)
3234 cifs_dbg(VFS, "per-share encryption not supported yet\n");
3235
3236 cap &= CIFS_UNIX_CAP_MASK;
3237 if (ctx && ctx->no_psx_acl)
3238 cap &= ~CIFS_UNIX_POSIX_ACL_CAP;
3239 else if (CIFS_UNIX_POSIX_ACL_CAP & cap) {
3240 cifs_dbg(FYI, "negotiated posix acl support\n");
3241 if (cifs_sb)
3242 cifs_sb->mnt_cifs_flags |=
3243 CIFS_MOUNT_POSIXACL;
3244 }
3245
3246 if (ctx && ctx->posix_paths == 0)
3247 cap &= ~CIFS_UNIX_POSIX_PATHNAMES_CAP;
3248 else if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) {
3249 cifs_dbg(FYI, "negotiate posix pathnames\n");
3250 if (cifs_sb)
3251 cifs_sb->mnt_cifs_flags |=
3252 CIFS_MOUNT_POSIX_PATHS;
3253 }
3254
3255 cifs_dbg(FYI, "Negotiate caps 0x%x\n", (int)cap);
3256 #ifdef CONFIG_CIFS_DEBUG2
3257 if (cap & CIFS_UNIX_FCNTL_CAP)
3258 cifs_dbg(FYI, "FCNTL cap\n");
3259 if (cap & CIFS_UNIX_EXTATTR_CAP)
3260 cifs_dbg(FYI, "EXTATTR cap\n");
3261 if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP)
3262 cifs_dbg(FYI, "POSIX path cap\n");
3263 if (cap & CIFS_UNIX_XATTR_CAP)
3264 cifs_dbg(FYI, "XATTR cap\n");
3265 if (cap & CIFS_UNIX_POSIX_ACL_CAP)
3266 cifs_dbg(FYI, "POSIX ACL cap\n");
3267 if (cap & CIFS_UNIX_LARGE_READ_CAP)
3268 cifs_dbg(FYI, "very large read cap\n");
3269 if (cap & CIFS_UNIX_LARGE_WRITE_CAP)
3270 cifs_dbg(FYI, "very large write cap\n");
3271 if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_CAP)
3272 cifs_dbg(FYI, "transport encryption cap\n");
3273 if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)
3274 cifs_dbg(FYI, "mandatory transport encryption cap\n");
3275 #endif /* CIFS_DEBUG2 */
3276 if (CIFSSMBSetFSUnixInfo(xid, tcon, cap)) {
3277 if (ctx == NULL)
3278 cifs_dbg(FYI, "resetting capabilities failed\n");
3279 else
3280 cifs_dbg(VFS, "Negotiating Unix capabilities with the server failed. Consider mounting with the Unix Extensions disabled if problems are found by specifying the nounix mount option.\n");
3281
3282 }
3283 }
3284 }
3285 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
3286
cifs_setup_cifs_sb(struct cifs_sb_info * cifs_sb)3287 int cifs_setup_cifs_sb(struct cifs_sb_info *cifs_sb)
3288 {
3289 struct smb3_fs_context *ctx = cifs_sb->ctx;
3290
3291 INIT_DELAYED_WORK(&cifs_sb->prune_tlinks, cifs_prune_tlinks);
3292
3293 spin_lock_init(&cifs_sb->tlink_tree_lock);
3294 cifs_sb->tlink_tree = RB_ROOT;
3295
3296 cifs_dbg(FYI, "file mode: %04ho dir mode: %04ho\n",
3297 ctx->file_mode, ctx->dir_mode);
3298
3299 /* this is needed for ASCII cp to Unicode converts */
3300 if (ctx->iocharset == NULL) {
3301 /* load_nls_default cannot return null */
3302 cifs_sb->local_nls = load_nls_default();
3303 } else {
3304 cifs_sb->local_nls = load_nls(ctx->iocharset);
3305 if (cifs_sb->local_nls == NULL) {
3306 cifs_dbg(VFS, "CIFS mount error: iocharset %s not found\n",
3307 ctx->iocharset);
3308 return -ELIBACC;
3309 }
3310 }
3311 ctx->local_nls = cifs_sb->local_nls;
3312
3313 smb3_update_mnt_flags(cifs_sb);
3314
3315 if (ctx->direct_io)
3316 cifs_dbg(FYI, "mounting share using direct i/o\n");
3317 if (ctx->cache_ro) {
3318 cifs_dbg(VFS, "mounting share with read only caching. Ensure that the share will not be modified while in use.\n");
3319 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_RO_CACHE;
3320 } else if (ctx->cache_rw) {
3321 cifs_dbg(VFS, "mounting share in single client RW caching mode. Ensure that no other systems will be accessing the share.\n");
3322 cifs_sb->mnt_cifs_flags |= (CIFS_MOUNT_RO_CACHE |
3323 CIFS_MOUNT_RW_CACHE);
3324 }
3325
3326 if ((ctx->cifs_acl) && (ctx->dynperm))
3327 cifs_dbg(VFS, "mount option dynperm ignored if cifsacl mount option supported\n");
3328
3329 if (ctx->prepath) {
3330 cifs_sb->prepath = kstrdup(ctx->prepath, GFP_KERNEL);
3331 if (cifs_sb->prepath == NULL)
3332 return -ENOMEM;
3333 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
3334 }
3335
3336 return 0;
3337 }
3338
3339 /* Release all succeed connections */
cifs_mount_put_conns(struct cifs_mount_ctx * mnt_ctx)3340 void cifs_mount_put_conns(struct cifs_mount_ctx *mnt_ctx)
3341 {
3342 int rc = 0;
3343
3344 if (mnt_ctx->tcon)
3345 cifs_put_tcon(mnt_ctx->tcon, netfs_trace_tcon_ref_put_mnt_ctx);
3346 else if (mnt_ctx->ses)
3347 cifs_put_smb_ses(mnt_ctx->ses);
3348 else if (mnt_ctx->server)
3349 cifs_put_tcp_session(mnt_ctx->server, 0);
3350 mnt_ctx->ses = NULL;
3351 mnt_ctx->tcon = NULL;
3352 mnt_ctx->server = NULL;
3353 mnt_ctx->cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_POSIX_PATHS;
3354 free_xid(mnt_ctx->xid);
3355 }
3356
cifs_mount_get_session(struct cifs_mount_ctx * mnt_ctx)3357 int cifs_mount_get_session(struct cifs_mount_ctx *mnt_ctx)
3358 {
3359 struct TCP_Server_Info *server = NULL;
3360 struct smb3_fs_context *ctx;
3361 struct cifs_ses *ses = NULL;
3362 unsigned int xid;
3363 int rc = 0;
3364
3365 xid = get_xid();
3366
3367 if (WARN_ON_ONCE(!mnt_ctx || !mnt_ctx->fs_ctx)) {
3368 rc = -EINVAL;
3369 goto out;
3370 }
3371 ctx = mnt_ctx->fs_ctx;
3372
3373 /* get a reference to a tcp session */
3374 server = cifs_get_tcp_session(ctx, NULL);
3375 if (IS_ERR(server)) {
3376 rc = PTR_ERR(server);
3377 server = NULL;
3378 goto out;
3379 }
3380
3381 /* get a reference to a SMB session */
3382 ses = cifs_get_smb_ses(server, ctx);
3383 if (IS_ERR(ses)) {
3384 rc = PTR_ERR(ses);
3385 ses = NULL;
3386 goto out;
3387 }
3388
3389 if ((ctx->persistent == true) && (!(ses->server->capabilities &
3390 SMB2_GLOBAL_CAP_PERSISTENT_HANDLES))) {
3391 cifs_server_dbg(VFS, "persistent handles not supported by server\n");
3392 rc = -EOPNOTSUPP;
3393 }
3394
3395 out:
3396 mnt_ctx->xid = xid;
3397 mnt_ctx->server = server;
3398 mnt_ctx->ses = ses;
3399 mnt_ctx->tcon = NULL;
3400
3401 return rc;
3402 }
3403
cifs_mount_get_tcon(struct cifs_mount_ctx * mnt_ctx)3404 int cifs_mount_get_tcon(struct cifs_mount_ctx *mnt_ctx)
3405 {
3406 struct TCP_Server_Info *server;
3407 struct cifs_sb_info *cifs_sb;
3408 struct smb3_fs_context *ctx;
3409 struct cifs_tcon *tcon = NULL;
3410 int rc = 0;
3411
3412 if (WARN_ON_ONCE(!mnt_ctx || !mnt_ctx->server || !mnt_ctx->ses || !mnt_ctx->fs_ctx ||
3413 !mnt_ctx->cifs_sb)) {
3414 rc = -EINVAL;
3415 goto out;
3416 }
3417 server = mnt_ctx->server;
3418 ctx = mnt_ctx->fs_ctx;
3419 cifs_sb = mnt_ctx->cifs_sb;
3420
3421 /* search for existing tcon to this server share */
3422 tcon = cifs_get_tcon(mnt_ctx->ses, ctx);
3423 if (IS_ERR(tcon)) {
3424 rc = PTR_ERR(tcon);
3425 tcon = NULL;
3426 goto out;
3427 }
3428
3429 /* if new SMB3.11 POSIX extensions are supported do not remap / and \ */
3430 if (tcon->posix_extensions)
3431 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_POSIX_PATHS;
3432
3433 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
3434 /* tell server which Unix caps we support */
3435 if (cap_unix(tcon->ses)) {
3436 /*
3437 * reset of caps checks mount to see if unix extensions disabled
3438 * for just this mount.
3439 */
3440 reset_cifs_unix_caps(mnt_ctx->xid, tcon, cifs_sb, ctx);
3441 spin_lock(&tcon->ses->server->srv_lock);
3442 if ((tcon->ses->server->tcpStatus == CifsNeedReconnect) &&
3443 (le64_to_cpu(tcon->fsUnixInfo.Capability) &
3444 CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)) {
3445 spin_unlock(&tcon->ses->server->srv_lock);
3446 rc = -EACCES;
3447 goto out;
3448 }
3449 spin_unlock(&tcon->ses->server->srv_lock);
3450 } else
3451 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
3452 tcon->unix_ext = 0; /* server does not support them */
3453
3454 /* do not care if a following call succeed - informational */
3455 if (!tcon->pipe && server->ops->qfs_tcon) {
3456 server->ops->qfs_tcon(mnt_ctx->xid, tcon, cifs_sb);
3457 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RO_CACHE) {
3458 if (tcon->fsDevInfo.DeviceCharacteristics &
3459 cpu_to_le32(FILE_READ_ONLY_DEVICE))
3460 cifs_dbg(VFS, "mounted to read only share\n");
3461 else if ((cifs_sb->mnt_cifs_flags &
3462 CIFS_MOUNT_RW_CACHE) == 0)
3463 cifs_dbg(VFS, "read only mount of RW share\n");
3464 /* no need to log a RW mount of a typical RW share */
3465 }
3466 }
3467
3468 /*
3469 * Clamp the rsize/wsize mount arguments if they are too big for the server
3470 * and set the rsize/wsize to the negotiated values if not passed in by
3471 * the user on mount
3472 */
3473 if ((cifs_sb->ctx->wsize == 0) ||
3474 (cifs_sb->ctx->wsize > server->ops->negotiate_wsize(tcon, ctx))) {
3475 cifs_sb->ctx->wsize =
3476 round_down(server->ops->negotiate_wsize(tcon, ctx), PAGE_SIZE);
3477 /*
3478 * in the very unlikely event that the server sent a max write size under PAGE_SIZE,
3479 * (which would get rounded down to 0) then reset wsize to absolute minimum eg 4096
3480 */
3481 if (cifs_sb->ctx->wsize == 0) {
3482 cifs_sb->ctx->wsize = PAGE_SIZE;
3483 cifs_dbg(VFS, "wsize too small, reset to minimum ie PAGE_SIZE, usually 4096\n");
3484 }
3485 }
3486 if ((cifs_sb->ctx->rsize == 0) ||
3487 (cifs_sb->ctx->rsize > server->ops->negotiate_rsize(tcon, ctx)))
3488 cifs_sb->ctx->rsize = server->ops->negotiate_rsize(tcon, ctx);
3489
3490 /*
3491 * The cookie is initialized from volume info returned above.
3492 * Inside cifs_fscache_get_super_cookie it checks
3493 * that we do not get super cookie twice.
3494 */
3495 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_FSCACHE)
3496 cifs_fscache_get_super_cookie(tcon);
3497
3498 out:
3499 mnt_ctx->tcon = tcon;
3500 return rc;
3501 }
3502
mount_setup_tlink(struct cifs_sb_info * cifs_sb,struct cifs_ses * ses,struct cifs_tcon * tcon)3503 static int mount_setup_tlink(struct cifs_sb_info *cifs_sb, struct cifs_ses *ses,
3504 struct cifs_tcon *tcon)
3505 {
3506 struct tcon_link *tlink;
3507
3508 /* hang the tcon off of the superblock */
3509 tlink = kzalloc(sizeof(*tlink), GFP_KERNEL);
3510 if (tlink == NULL)
3511 return -ENOMEM;
3512
3513 tlink->tl_uid = ses->linux_uid;
3514 tlink->tl_tcon = tcon;
3515 tlink->tl_time = jiffies;
3516 set_bit(TCON_LINK_MASTER, &tlink->tl_flags);
3517 set_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
3518
3519 cifs_sb->master_tlink = tlink;
3520 spin_lock(&cifs_sb->tlink_tree_lock);
3521 tlink_rb_insert(&cifs_sb->tlink_tree, tlink);
3522 spin_unlock(&cifs_sb->tlink_tree_lock);
3523
3524 queue_delayed_work(cifsiod_wq, &cifs_sb->prune_tlinks,
3525 TLINK_IDLE_EXPIRE);
3526 return 0;
3527 }
3528
3529 static int
cifs_are_all_path_components_accessible(struct TCP_Server_Info * server,unsigned int xid,struct cifs_tcon * tcon,struct cifs_sb_info * cifs_sb,char * full_path,int added_treename)3530 cifs_are_all_path_components_accessible(struct TCP_Server_Info *server,
3531 unsigned int xid,
3532 struct cifs_tcon *tcon,
3533 struct cifs_sb_info *cifs_sb,
3534 char *full_path,
3535 int added_treename)
3536 {
3537 int rc;
3538 char *s;
3539 char sep, tmp;
3540 int skip = added_treename ? 1 : 0;
3541
3542 sep = CIFS_DIR_SEP(cifs_sb);
3543 s = full_path;
3544
3545 rc = server->ops->is_path_accessible(xid, tcon, cifs_sb, "");
3546 while (rc == 0) {
3547 /* skip separators */
3548 while (*s == sep)
3549 s++;
3550 if (!*s)
3551 break;
3552 /* next separator */
3553 while (*s && *s != sep)
3554 s++;
3555 /*
3556 * if the treename is added, we then have to skip the first
3557 * part within the separators
3558 */
3559 if (skip) {
3560 skip = 0;
3561 continue;
3562 }
3563 /*
3564 * temporarily null-terminate the path at the end of
3565 * the current component
3566 */
3567 tmp = *s;
3568 *s = 0;
3569 rc = server->ops->is_path_accessible(xid, tcon, cifs_sb,
3570 full_path);
3571 *s = tmp;
3572 }
3573 return rc;
3574 }
3575
3576 /*
3577 * Check if path is remote (i.e. a DFS share).
3578 *
3579 * Return -EREMOTE if it is, otherwise 0 or -errno.
3580 */
cifs_is_path_remote(struct cifs_mount_ctx * mnt_ctx)3581 int cifs_is_path_remote(struct cifs_mount_ctx *mnt_ctx)
3582 {
3583 int rc;
3584 struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3585 struct TCP_Server_Info *server = mnt_ctx->server;
3586 unsigned int xid = mnt_ctx->xid;
3587 struct cifs_tcon *tcon = mnt_ctx->tcon;
3588 struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
3589 char *full_path;
3590
3591 if (!server->ops->is_path_accessible)
3592 return -EOPNOTSUPP;
3593
3594 /*
3595 * cifs_build_path_to_root works only when we have a valid tcon
3596 */
3597 full_path = cifs_build_path_to_root(ctx, cifs_sb, tcon,
3598 tcon->Flags & SMB_SHARE_IS_IN_DFS);
3599 if (full_path == NULL)
3600 return -ENOMEM;
3601
3602 cifs_dbg(FYI, "%s: full_path: %s\n", __func__, full_path);
3603
3604 rc = server->ops->is_path_accessible(xid, tcon, cifs_sb,
3605 full_path);
3606 if (rc != 0 && rc != -EREMOTE)
3607 goto out;
3608
3609 if (rc != -EREMOTE) {
3610 rc = cifs_are_all_path_components_accessible(server, xid, tcon,
3611 cifs_sb, full_path, tcon->Flags & SMB_SHARE_IS_IN_DFS);
3612 if (rc != 0) {
3613 cifs_server_dbg(VFS, "cannot query dirs between root and final path, enabling CIFS_MOUNT_USE_PREFIX_PATH\n");
3614 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
3615 rc = 0;
3616 }
3617 }
3618
3619 out:
3620 kfree(full_path);
3621 return rc;
3622 }
3623
3624 #ifdef CONFIG_CIFS_DFS_UPCALL
cifs_mount(struct cifs_sb_info * cifs_sb,struct smb3_fs_context * ctx)3625 int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
3626 {
3627 struct cifs_mount_ctx mnt_ctx = { .cifs_sb = cifs_sb, .fs_ctx = ctx, };
3628 int rc;
3629
3630 rc = dfs_mount_share(&mnt_ctx);
3631 if (rc)
3632 goto error;
3633 if (!ctx->dfs_conn)
3634 goto out;
3635
3636 /*
3637 * After reconnecting to a different server, unique ids won't match anymore, so we disable
3638 * serverino. This prevents dentry revalidation to think the dentry are stale (ESTALE).
3639 */
3640 cifs_autodisable_serverino(cifs_sb);
3641 /*
3642 * Force the use of prefix path to support failover on DFS paths that resolve to targets
3643 * that have different prefix paths.
3644 */
3645 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
3646 kfree(cifs_sb->prepath);
3647 cifs_sb->prepath = ctx->prepath;
3648 ctx->prepath = NULL;
3649
3650 out:
3651 cifs_try_adding_channels(mnt_ctx.ses);
3652 rc = mount_setup_tlink(cifs_sb, mnt_ctx.ses, mnt_ctx.tcon);
3653 if (rc)
3654 goto error;
3655
3656 free_xid(mnt_ctx.xid);
3657 return rc;
3658
3659 error:
3660 cifs_mount_put_conns(&mnt_ctx);
3661 return rc;
3662 }
3663 #else
cifs_mount(struct cifs_sb_info * cifs_sb,struct smb3_fs_context * ctx)3664 int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
3665 {
3666 int rc = 0;
3667 struct cifs_mount_ctx mnt_ctx = { .cifs_sb = cifs_sb, .fs_ctx = ctx, };
3668
3669 rc = cifs_mount_get_session(&mnt_ctx);
3670 if (rc)
3671 goto error;
3672
3673 rc = cifs_mount_get_tcon(&mnt_ctx);
3674 if (!rc) {
3675 /*
3676 * Prevent superblock from being created with any missing
3677 * connections.
3678 */
3679 if (WARN_ON(!mnt_ctx.server))
3680 rc = -EHOSTDOWN;
3681 else if (WARN_ON(!mnt_ctx.ses))
3682 rc = -EACCES;
3683 else if (WARN_ON(!mnt_ctx.tcon))
3684 rc = -ENOENT;
3685 }
3686 if (rc)
3687 goto error;
3688
3689 rc = cifs_is_path_remote(&mnt_ctx);
3690 if (rc == -EREMOTE)
3691 rc = -EOPNOTSUPP;
3692 if (rc)
3693 goto error;
3694
3695 rc = mount_setup_tlink(cifs_sb, mnt_ctx.ses, mnt_ctx.tcon);
3696 if (rc)
3697 goto error;
3698
3699 free_xid(mnt_ctx.xid);
3700 return rc;
3701
3702 error:
3703 cifs_mount_put_conns(&mnt_ctx);
3704 return rc;
3705 }
3706 #endif
3707
3708 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
3709 /*
3710 * Issue a TREE_CONNECT request.
3711 */
3712 int
CIFSTCon(const unsigned int xid,struct cifs_ses * ses,const char * tree,struct cifs_tcon * tcon,const struct nls_table * nls_codepage)3713 CIFSTCon(const unsigned int xid, struct cifs_ses *ses,
3714 const char *tree, struct cifs_tcon *tcon,
3715 const struct nls_table *nls_codepage)
3716 {
3717 struct smb_hdr *smb_buffer;
3718 struct smb_hdr *smb_buffer_response;
3719 TCONX_REQ *pSMB;
3720 TCONX_RSP *pSMBr;
3721 unsigned char *bcc_ptr;
3722 int rc = 0;
3723 int length;
3724 __u16 bytes_left, count;
3725
3726 if (ses == NULL)
3727 return -EIO;
3728
3729 smb_buffer = cifs_buf_get();
3730 if (smb_buffer == NULL)
3731 return -ENOMEM;
3732
3733 smb_buffer_response = smb_buffer;
3734
3735 header_assemble(smb_buffer, SMB_COM_TREE_CONNECT_ANDX,
3736 NULL /*no tid */, 4 /*wct */);
3737
3738 smb_buffer->Mid = get_next_mid(ses->server);
3739 smb_buffer->Uid = ses->Suid;
3740 pSMB = (TCONX_REQ *) smb_buffer;
3741 pSMBr = (TCONX_RSP *) smb_buffer_response;
3742
3743 pSMB->AndXCommand = 0xFF;
3744 pSMB->Flags = cpu_to_le16(TCON_EXTENDED_SECINFO);
3745 bcc_ptr = &pSMB->Password[0];
3746
3747 pSMB->PasswordLength = cpu_to_le16(1); /* minimum */
3748 *bcc_ptr = 0; /* password is null byte */
3749 bcc_ptr++; /* skip password */
3750 /* already aligned so no need to do it below */
3751
3752 if (ses->server->sign)
3753 smb_buffer->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
3754
3755 if (ses->capabilities & CAP_STATUS32)
3756 smb_buffer->Flags2 |= SMBFLG2_ERR_STATUS;
3757
3758 if (ses->capabilities & CAP_DFS)
3759 smb_buffer->Flags2 |= SMBFLG2_DFS;
3760
3761 if (ses->capabilities & CAP_UNICODE) {
3762 smb_buffer->Flags2 |= SMBFLG2_UNICODE;
3763 length =
3764 cifs_strtoUTF16((__le16 *) bcc_ptr, tree,
3765 6 /* max utf8 char length in bytes */ *
3766 (/* server len*/ + 256 /* share len */), nls_codepage);
3767 bcc_ptr += 2 * length; /* convert num 16 bit words to bytes */
3768 bcc_ptr += 2; /* skip trailing null */
3769 } else { /* ASCII */
3770 strcpy(bcc_ptr, tree);
3771 bcc_ptr += strlen(tree) + 1;
3772 }
3773 strcpy(bcc_ptr, "?????");
3774 bcc_ptr += strlen("?????");
3775 bcc_ptr += 1;
3776 count = bcc_ptr - &pSMB->Password[0];
3777 be32_add_cpu(&pSMB->hdr.smb_buf_length, count);
3778 pSMB->ByteCount = cpu_to_le16(count);
3779
3780 rc = SendReceive(xid, ses, smb_buffer, smb_buffer_response, &length,
3781 0);
3782
3783 /* above now done in SendReceive */
3784 if (rc == 0) {
3785 bool is_unicode;
3786
3787 tcon->tid = smb_buffer_response->Tid;
3788 bcc_ptr = pByteArea(smb_buffer_response);
3789 bytes_left = get_bcc(smb_buffer_response);
3790 length = strnlen(bcc_ptr, bytes_left - 2);
3791 if (smb_buffer->Flags2 & SMBFLG2_UNICODE)
3792 is_unicode = true;
3793 else
3794 is_unicode = false;
3795
3796
3797 /* skip service field (NB: this field is always ASCII) */
3798 if (length == 3) {
3799 if ((bcc_ptr[0] == 'I') && (bcc_ptr[1] == 'P') &&
3800 (bcc_ptr[2] == 'C')) {
3801 cifs_dbg(FYI, "IPC connection\n");
3802 tcon->ipc = true;
3803 tcon->pipe = true;
3804 }
3805 } else if (length == 2) {
3806 if ((bcc_ptr[0] == 'A') && (bcc_ptr[1] == ':')) {
3807 /* the most common case */
3808 cifs_dbg(FYI, "disk share connection\n");
3809 }
3810 }
3811 bcc_ptr += length + 1;
3812 bytes_left -= (length + 1);
3813 strscpy(tcon->tree_name, tree, sizeof(tcon->tree_name));
3814
3815 /* mostly informational -- no need to fail on error here */
3816 kfree(tcon->nativeFileSystem);
3817 tcon->nativeFileSystem = cifs_strndup_from_utf16(bcc_ptr,
3818 bytes_left, is_unicode,
3819 nls_codepage);
3820
3821 cifs_dbg(FYI, "nativeFileSystem=%s\n", tcon->nativeFileSystem);
3822
3823 if ((smb_buffer_response->WordCount == 3) ||
3824 (smb_buffer_response->WordCount == 7))
3825 /* field is in same location */
3826 tcon->Flags = le16_to_cpu(pSMBr->OptionalSupport);
3827 else
3828 tcon->Flags = 0;
3829 cifs_dbg(FYI, "Tcon flags: 0x%x\n", tcon->Flags);
3830
3831 /*
3832 * reset_cifs_unix_caps calls QFSInfo which requires
3833 * need_reconnect to be false, but we would not need to call
3834 * reset_caps if this were not a reconnect case so must check
3835 * need_reconnect flag here. The caller will also clear
3836 * need_reconnect when tcon was successful but needed to be
3837 * cleared earlier in the case of unix extensions reconnect
3838 */
3839 if (tcon->need_reconnect && tcon->unix_ext) {
3840 cifs_dbg(FYI, "resetting caps for %s\n", tcon->tree_name);
3841 tcon->need_reconnect = false;
3842 reset_cifs_unix_caps(xid, tcon, NULL, NULL);
3843 }
3844 }
3845 cifs_buf_release(smb_buffer);
3846 return rc;
3847 }
3848 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
3849
delayed_free(struct rcu_head * p)3850 static void delayed_free(struct rcu_head *p)
3851 {
3852 struct cifs_sb_info *cifs_sb = container_of(p, struct cifs_sb_info, rcu);
3853
3854 unload_nls(cifs_sb->local_nls);
3855 smb3_cleanup_fs_context(cifs_sb->ctx);
3856 kfree(cifs_sb);
3857 }
3858
3859 void
cifs_umount(struct cifs_sb_info * cifs_sb)3860 cifs_umount(struct cifs_sb_info *cifs_sb)
3861 {
3862 struct rb_root *root = &cifs_sb->tlink_tree;
3863 struct rb_node *node;
3864 struct tcon_link *tlink;
3865
3866 cancel_delayed_work_sync(&cifs_sb->prune_tlinks);
3867
3868 spin_lock(&cifs_sb->tlink_tree_lock);
3869 while ((node = rb_first(root))) {
3870 tlink = rb_entry(node, struct tcon_link, tl_rbnode);
3871 cifs_get_tlink(tlink);
3872 clear_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
3873 rb_erase(node, root);
3874
3875 spin_unlock(&cifs_sb->tlink_tree_lock);
3876 cifs_put_tlink(tlink);
3877 spin_lock(&cifs_sb->tlink_tree_lock);
3878 }
3879 spin_unlock(&cifs_sb->tlink_tree_lock);
3880
3881 kfree(cifs_sb->prepath);
3882 call_rcu(&cifs_sb->rcu, delayed_free);
3883 }
3884
3885 int
cifs_negotiate_protocol(const unsigned int xid,struct cifs_ses * ses,struct TCP_Server_Info * server)3886 cifs_negotiate_protocol(const unsigned int xid, struct cifs_ses *ses,
3887 struct TCP_Server_Info *server)
3888 {
3889 int rc = 0;
3890
3891 if (!server->ops->need_neg || !server->ops->negotiate)
3892 return -ENOSYS;
3893
3894 /* only send once per connect */
3895 spin_lock(&server->srv_lock);
3896 if (server->tcpStatus != CifsGood &&
3897 server->tcpStatus != CifsNew &&
3898 server->tcpStatus != CifsNeedNegotiate) {
3899 spin_unlock(&server->srv_lock);
3900 return -EHOSTDOWN;
3901 }
3902
3903 if (!server->ops->need_neg(server) &&
3904 server->tcpStatus == CifsGood) {
3905 spin_unlock(&server->srv_lock);
3906 return 0;
3907 }
3908
3909 server->tcpStatus = CifsInNegotiate;
3910 spin_unlock(&server->srv_lock);
3911
3912 rc = server->ops->negotiate(xid, ses, server);
3913 if (rc == 0) {
3914 spin_lock(&server->srv_lock);
3915 if (server->tcpStatus == CifsInNegotiate)
3916 server->tcpStatus = CifsGood;
3917 else
3918 rc = -EHOSTDOWN;
3919 spin_unlock(&server->srv_lock);
3920 } else {
3921 spin_lock(&server->srv_lock);
3922 if (server->tcpStatus == CifsInNegotiate)
3923 server->tcpStatus = CifsNeedNegotiate;
3924 spin_unlock(&server->srv_lock);
3925 }
3926
3927 return rc;
3928 }
3929
3930 int
cifs_setup_session(const unsigned int xid,struct cifs_ses * ses,struct TCP_Server_Info * server,struct nls_table * nls_info)3931 cifs_setup_session(const unsigned int xid, struct cifs_ses *ses,
3932 struct TCP_Server_Info *server,
3933 struct nls_table *nls_info)
3934 {
3935 int rc = -ENOSYS;
3936 struct TCP_Server_Info *pserver = SERVER_IS_CHAN(server) ? server->primary_server : server;
3937 struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&pserver->dstaddr;
3938 struct sockaddr_in *addr = (struct sockaddr_in *)&pserver->dstaddr;
3939 bool is_binding = false;
3940
3941 spin_lock(&ses->ses_lock);
3942 cifs_dbg(FYI, "%s: channel connect bitmap: 0x%lx\n",
3943 __func__, ses->chans_need_reconnect);
3944
3945 if (ses->ses_status != SES_GOOD &&
3946 ses->ses_status != SES_NEW &&
3947 ses->ses_status != SES_NEED_RECON) {
3948 spin_unlock(&ses->ses_lock);
3949 return -EHOSTDOWN;
3950 }
3951
3952 /* only send once per connect */
3953 spin_lock(&ses->chan_lock);
3954 if (CIFS_ALL_CHANS_GOOD(ses)) {
3955 if (ses->ses_status == SES_NEED_RECON)
3956 ses->ses_status = SES_GOOD;
3957 spin_unlock(&ses->chan_lock);
3958 spin_unlock(&ses->ses_lock);
3959 return 0;
3960 }
3961
3962 cifs_chan_set_in_reconnect(ses, server);
3963 is_binding = !CIFS_ALL_CHANS_NEED_RECONNECT(ses);
3964 spin_unlock(&ses->chan_lock);
3965
3966 if (!is_binding) {
3967 ses->ses_status = SES_IN_SETUP;
3968
3969 /* force iface_list refresh */
3970 ses->iface_last_update = 0;
3971 }
3972 spin_unlock(&ses->ses_lock);
3973
3974 /* update ses ip_addr only for primary chan */
3975 if (server == pserver) {
3976 if (server->dstaddr.ss_family == AF_INET6)
3977 scnprintf(ses->ip_addr, sizeof(ses->ip_addr), "%pI6", &addr6->sin6_addr);
3978 else
3979 scnprintf(ses->ip_addr, sizeof(ses->ip_addr), "%pI4", &addr->sin_addr);
3980 }
3981
3982 if (!is_binding) {
3983 ses->capabilities = server->capabilities;
3984 if (!linuxExtEnabled)
3985 ses->capabilities &= (~server->vals->cap_unix);
3986
3987 if (ses->auth_key.response) {
3988 cifs_dbg(FYI, "Free previous auth_key.response = %p\n",
3989 ses->auth_key.response);
3990 kfree_sensitive(ses->auth_key.response);
3991 ses->auth_key.response = NULL;
3992 ses->auth_key.len = 0;
3993 }
3994 }
3995
3996 cifs_dbg(FYI, "Security Mode: 0x%x Capabilities: 0x%x TimeAdjust: %d\n",
3997 server->sec_mode, server->capabilities, server->timeAdj);
3998
3999 if (server->ops->sess_setup)
4000 rc = server->ops->sess_setup(xid, ses, server, nls_info);
4001
4002 if (rc) {
4003 cifs_server_dbg(VFS, "Send error in SessSetup = %d\n", rc);
4004 spin_lock(&ses->ses_lock);
4005 if (ses->ses_status == SES_IN_SETUP)
4006 ses->ses_status = SES_NEED_RECON;
4007 spin_lock(&ses->chan_lock);
4008 cifs_chan_clear_in_reconnect(ses, server);
4009 spin_unlock(&ses->chan_lock);
4010 spin_unlock(&ses->ses_lock);
4011 } else {
4012 spin_lock(&ses->ses_lock);
4013 if (ses->ses_status == SES_IN_SETUP)
4014 ses->ses_status = SES_GOOD;
4015 spin_lock(&ses->chan_lock);
4016 cifs_chan_clear_in_reconnect(ses, server);
4017 cifs_chan_clear_need_reconnect(ses, server);
4018 spin_unlock(&ses->chan_lock);
4019 spin_unlock(&ses->ses_lock);
4020 }
4021
4022 return rc;
4023 }
4024
4025 static int
cifs_set_vol_auth(struct smb3_fs_context * ctx,struct cifs_ses * ses)4026 cifs_set_vol_auth(struct smb3_fs_context *ctx, struct cifs_ses *ses)
4027 {
4028 ctx->sectype = ses->sectype;
4029
4030 /* krb5 is special, since we don't need username or pw */
4031 if (ctx->sectype == Kerberos)
4032 return 0;
4033
4034 return cifs_set_cifscreds(ctx, ses);
4035 }
4036
4037 static struct cifs_tcon *
cifs_construct_tcon(struct cifs_sb_info * cifs_sb,kuid_t fsuid)4038 cifs_construct_tcon(struct cifs_sb_info *cifs_sb, kuid_t fsuid)
4039 {
4040 int rc;
4041 struct cifs_tcon *master_tcon = cifs_sb_master_tcon(cifs_sb);
4042 struct cifs_ses *ses;
4043 struct cifs_tcon *tcon = NULL;
4044 struct smb3_fs_context *ctx;
4045 char *origin_fullpath = NULL;
4046
4047 ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
4048 if (ctx == NULL)
4049 return ERR_PTR(-ENOMEM);
4050
4051 ctx->local_nls = cifs_sb->local_nls;
4052 ctx->linux_uid = fsuid;
4053 ctx->cred_uid = fsuid;
4054 ctx->UNC = master_tcon->tree_name;
4055 ctx->retry = master_tcon->retry;
4056 ctx->nocase = master_tcon->nocase;
4057 ctx->nohandlecache = master_tcon->nohandlecache;
4058 ctx->local_lease = master_tcon->local_lease;
4059 ctx->no_lease = master_tcon->no_lease;
4060 ctx->resilient = master_tcon->use_resilient;
4061 ctx->persistent = master_tcon->use_persistent;
4062 ctx->handle_timeout = master_tcon->handle_timeout;
4063 ctx->no_linux_ext = !master_tcon->unix_ext;
4064 ctx->linux_ext = master_tcon->posix_extensions;
4065 ctx->sectype = master_tcon->ses->sectype;
4066 ctx->sign = master_tcon->ses->sign;
4067 ctx->seal = master_tcon->seal;
4068 ctx->witness = master_tcon->use_witness;
4069 ctx->dfs_root_ses = master_tcon->ses->dfs_root_ses;
4070
4071 rc = cifs_set_vol_auth(ctx, master_tcon->ses);
4072 if (rc) {
4073 tcon = ERR_PTR(rc);
4074 goto out;
4075 }
4076
4077 /* get a reference for the same TCP session */
4078 spin_lock(&cifs_tcp_ses_lock);
4079 ++master_tcon->ses->server->srv_count;
4080 spin_unlock(&cifs_tcp_ses_lock);
4081
4082 ses = cifs_get_smb_ses(master_tcon->ses->server, ctx);
4083 if (IS_ERR(ses)) {
4084 tcon = ERR_CAST(ses);
4085 cifs_put_tcp_session(master_tcon->ses->server, 0);
4086 goto out;
4087 }
4088
4089 #ifdef CONFIG_CIFS_DFS_UPCALL
4090 spin_lock(&master_tcon->tc_lock);
4091 if (master_tcon->origin_fullpath) {
4092 spin_unlock(&master_tcon->tc_lock);
4093 origin_fullpath = dfs_get_path(cifs_sb, cifs_sb->ctx->source);
4094 if (IS_ERR(origin_fullpath)) {
4095 tcon = ERR_CAST(origin_fullpath);
4096 origin_fullpath = NULL;
4097 cifs_put_smb_ses(ses);
4098 goto out;
4099 }
4100 } else {
4101 spin_unlock(&master_tcon->tc_lock);
4102 }
4103 #endif
4104
4105 tcon = cifs_get_tcon(ses, ctx);
4106 if (IS_ERR(tcon)) {
4107 cifs_put_smb_ses(ses);
4108 goto out;
4109 }
4110
4111 #ifdef CONFIG_CIFS_DFS_UPCALL
4112 if (origin_fullpath) {
4113 spin_lock(&tcon->tc_lock);
4114 tcon->origin_fullpath = origin_fullpath;
4115 spin_unlock(&tcon->tc_lock);
4116 origin_fullpath = NULL;
4117 queue_delayed_work(dfscache_wq, &tcon->dfs_cache_work,
4118 dfs_cache_get_ttl() * HZ);
4119 }
4120 #endif
4121
4122 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
4123 if (cap_unix(ses))
4124 reset_cifs_unix_caps(0, tcon, NULL, ctx);
4125 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
4126
4127 out:
4128 kfree(ctx->username);
4129 kfree_sensitive(ctx->password);
4130 kfree(origin_fullpath);
4131 kfree(ctx);
4132
4133 return tcon;
4134 }
4135
4136 struct cifs_tcon *
cifs_sb_master_tcon(struct cifs_sb_info * cifs_sb)4137 cifs_sb_master_tcon(struct cifs_sb_info *cifs_sb)
4138 {
4139 return tlink_tcon(cifs_sb_master_tlink(cifs_sb));
4140 }
4141
4142 /* find and return a tlink with given uid */
4143 static struct tcon_link *
tlink_rb_search(struct rb_root * root,kuid_t uid)4144 tlink_rb_search(struct rb_root *root, kuid_t uid)
4145 {
4146 struct rb_node *node = root->rb_node;
4147 struct tcon_link *tlink;
4148
4149 while (node) {
4150 tlink = rb_entry(node, struct tcon_link, tl_rbnode);
4151
4152 if (uid_gt(tlink->tl_uid, uid))
4153 node = node->rb_left;
4154 else if (uid_lt(tlink->tl_uid, uid))
4155 node = node->rb_right;
4156 else
4157 return tlink;
4158 }
4159 return NULL;
4160 }
4161
4162 /* insert a tcon_link into the tree */
4163 static void
tlink_rb_insert(struct rb_root * root,struct tcon_link * new_tlink)4164 tlink_rb_insert(struct rb_root *root, struct tcon_link *new_tlink)
4165 {
4166 struct rb_node **new = &(root->rb_node), *parent = NULL;
4167 struct tcon_link *tlink;
4168
4169 while (*new) {
4170 tlink = rb_entry(*new, struct tcon_link, tl_rbnode);
4171 parent = *new;
4172
4173 if (uid_gt(tlink->tl_uid, new_tlink->tl_uid))
4174 new = &((*new)->rb_left);
4175 else
4176 new = &((*new)->rb_right);
4177 }
4178
4179 rb_link_node(&new_tlink->tl_rbnode, parent, new);
4180 rb_insert_color(&new_tlink->tl_rbnode, root);
4181 }
4182
4183 /*
4184 * Find or construct an appropriate tcon given a cifs_sb and the fsuid of the
4185 * current task.
4186 *
4187 * If the superblock doesn't refer to a multiuser mount, then just return
4188 * the master tcon for the mount.
4189 *
4190 * First, search the rbtree for an existing tcon for this fsuid. If one
4191 * exists, then check to see if it's pending construction. If it is then wait
4192 * for construction to complete. Once it's no longer pending, check to see if
4193 * it failed and either return an error or retry construction, depending on
4194 * the timeout.
4195 *
4196 * If one doesn't exist then insert a new tcon_link struct into the tree and
4197 * try to construct a new one.
4198 *
4199 * REMEMBER to call cifs_put_tlink() after successful calls to cifs_sb_tlink,
4200 * to avoid refcount issues
4201 */
4202 struct tcon_link *
cifs_sb_tlink(struct cifs_sb_info * cifs_sb)4203 cifs_sb_tlink(struct cifs_sb_info *cifs_sb)
4204 {
4205 struct tcon_link *tlink, *newtlink;
4206 kuid_t fsuid = current_fsuid();
4207 int err;
4208
4209 if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER))
4210 return cifs_get_tlink(cifs_sb_master_tlink(cifs_sb));
4211
4212 spin_lock(&cifs_sb->tlink_tree_lock);
4213 tlink = tlink_rb_search(&cifs_sb->tlink_tree, fsuid);
4214 if (tlink)
4215 cifs_get_tlink(tlink);
4216 spin_unlock(&cifs_sb->tlink_tree_lock);
4217
4218 if (tlink == NULL) {
4219 newtlink = kzalloc(sizeof(*tlink), GFP_KERNEL);
4220 if (newtlink == NULL)
4221 return ERR_PTR(-ENOMEM);
4222 newtlink->tl_uid = fsuid;
4223 newtlink->tl_tcon = ERR_PTR(-EACCES);
4224 set_bit(TCON_LINK_PENDING, &newtlink->tl_flags);
4225 set_bit(TCON_LINK_IN_TREE, &newtlink->tl_flags);
4226 cifs_get_tlink(newtlink);
4227
4228 spin_lock(&cifs_sb->tlink_tree_lock);
4229 /* was one inserted after previous search? */
4230 tlink = tlink_rb_search(&cifs_sb->tlink_tree, fsuid);
4231 if (tlink) {
4232 cifs_get_tlink(tlink);
4233 spin_unlock(&cifs_sb->tlink_tree_lock);
4234 kfree(newtlink);
4235 goto wait_for_construction;
4236 }
4237 tlink = newtlink;
4238 tlink_rb_insert(&cifs_sb->tlink_tree, tlink);
4239 spin_unlock(&cifs_sb->tlink_tree_lock);
4240 } else {
4241 wait_for_construction:
4242 err = wait_on_bit(&tlink->tl_flags, TCON_LINK_PENDING,
4243 TASK_INTERRUPTIBLE);
4244 if (err) {
4245 cifs_put_tlink(tlink);
4246 return ERR_PTR(-ERESTARTSYS);
4247 }
4248
4249 /* if it's good, return it */
4250 if (!IS_ERR(tlink->tl_tcon))
4251 return tlink;
4252
4253 /* return error if we tried this already recently */
4254 if (time_before(jiffies, tlink->tl_time + TLINK_ERROR_EXPIRE)) {
4255 err = PTR_ERR(tlink->tl_tcon);
4256 cifs_put_tlink(tlink);
4257 return ERR_PTR(err);
4258 }
4259
4260 if (test_and_set_bit(TCON_LINK_PENDING, &tlink->tl_flags))
4261 goto wait_for_construction;
4262 }
4263
4264 tlink->tl_tcon = cifs_construct_tcon(cifs_sb, fsuid);
4265 clear_bit(TCON_LINK_PENDING, &tlink->tl_flags);
4266 wake_up_bit(&tlink->tl_flags, TCON_LINK_PENDING);
4267
4268 if (IS_ERR(tlink->tl_tcon)) {
4269 err = PTR_ERR(tlink->tl_tcon);
4270 if (err == -ENOKEY)
4271 err = -EACCES;
4272 cifs_put_tlink(tlink);
4273 return ERR_PTR(err);
4274 }
4275
4276 return tlink;
4277 }
4278
4279 /*
4280 * periodic workqueue job that scans tcon_tree for a superblock and closes
4281 * out tcons.
4282 */
4283 static void
cifs_prune_tlinks(struct work_struct * work)4284 cifs_prune_tlinks(struct work_struct *work)
4285 {
4286 struct cifs_sb_info *cifs_sb = container_of(work, struct cifs_sb_info,
4287 prune_tlinks.work);
4288 struct rb_root *root = &cifs_sb->tlink_tree;
4289 struct rb_node *node;
4290 struct rb_node *tmp;
4291 struct tcon_link *tlink;
4292
4293 /*
4294 * Because we drop the spinlock in the loop in order to put the tlink
4295 * it's not guarded against removal of links from the tree. The only
4296 * places that remove entries from the tree are this function and
4297 * umounts. Because this function is non-reentrant and is canceled
4298 * before umount can proceed, this is safe.
4299 */
4300 spin_lock(&cifs_sb->tlink_tree_lock);
4301 node = rb_first(root);
4302 while (node != NULL) {
4303 tmp = node;
4304 node = rb_next(tmp);
4305 tlink = rb_entry(tmp, struct tcon_link, tl_rbnode);
4306
4307 if (test_bit(TCON_LINK_MASTER, &tlink->tl_flags) ||
4308 atomic_read(&tlink->tl_count) != 0 ||
4309 time_after(tlink->tl_time + TLINK_IDLE_EXPIRE, jiffies))
4310 continue;
4311
4312 cifs_get_tlink(tlink);
4313 clear_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
4314 rb_erase(tmp, root);
4315
4316 spin_unlock(&cifs_sb->tlink_tree_lock);
4317 cifs_put_tlink(tlink);
4318 spin_lock(&cifs_sb->tlink_tree_lock);
4319 }
4320 spin_unlock(&cifs_sb->tlink_tree_lock);
4321
4322 queue_delayed_work(cifsiod_wq, &cifs_sb->prune_tlinks,
4323 TLINK_IDLE_EXPIRE);
4324 }
4325
4326 #ifndef CONFIG_CIFS_DFS_UPCALL
cifs_tree_connect(const unsigned int xid,struct cifs_tcon * tcon,const struct nls_table * nlsc)4327 int cifs_tree_connect(const unsigned int xid, struct cifs_tcon *tcon, const struct nls_table *nlsc)
4328 {
4329 int rc;
4330 const struct smb_version_operations *ops = tcon->ses->server->ops;
4331
4332 /* only send once per connect */
4333 spin_lock(&tcon->tc_lock);
4334
4335 /* if tcon is marked for needing reconnect, update state */
4336 if (tcon->need_reconnect)
4337 tcon->status = TID_NEED_TCON;
4338
4339 if (tcon->status == TID_GOOD) {
4340 spin_unlock(&tcon->tc_lock);
4341 return 0;
4342 }
4343
4344 if (tcon->status != TID_NEW &&
4345 tcon->status != TID_NEED_TCON) {
4346 spin_unlock(&tcon->tc_lock);
4347 return -EHOSTDOWN;
4348 }
4349
4350 tcon->status = TID_IN_TCON;
4351 spin_unlock(&tcon->tc_lock);
4352
4353 rc = ops->tree_connect(xid, tcon->ses, tcon->tree_name, tcon, nlsc);
4354 if (rc) {
4355 spin_lock(&tcon->tc_lock);
4356 if (tcon->status == TID_IN_TCON)
4357 tcon->status = TID_NEED_TCON;
4358 spin_unlock(&tcon->tc_lock);
4359 } else {
4360 spin_lock(&tcon->tc_lock);
4361 if (tcon->status == TID_IN_TCON)
4362 tcon->status = TID_GOOD;
4363 tcon->need_reconnect = false;
4364 spin_unlock(&tcon->tc_lock);
4365 }
4366
4367 return rc;
4368 }
4369 #endif
4370