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