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 struct sockaddr_storage ss;
76 int rc;
77
78 if (!server->hostname)
79 return -EINVAL;
80
81 /* if server hostname isn't populated, there's nothing to do here */
82 if (server->hostname[0] == '\0')
83 return 0;
84
85 spin_lock(&server->srv_lock);
86 ss = server->dstaddr;
87 spin_unlock(&server->srv_lock);
88
89 rc = dns_resolve_name(server->dns_dom, server->hostname,
90 strlen(server->hostname),
91 (struct sockaddr *)&ss);
92 if (!rc) {
93 spin_lock(&server->srv_lock);
94 memcpy(&server->dstaddr, &ss, sizeof(server->dstaddr));
95 spin_unlock(&server->srv_lock);
96 }
97 return rc;
98 }
99
smb2_query_server_interfaces(struct work_struct * work)100 static void smb2_query_server_interfaces(struct work_struct *work)
101 {
102 int rc;
103 int xid;
104 struct cifs_tcon *tcon = container_of(work,
105 struct cifs_tcon,
106 query_interfaces.work);
107 struct TCP_Server_Info *server = tcon->ses->server;
108
109 /*
110 * query server network interfaces, in case they change
111 */
112 if (!server->ops->query_server_interfaces)
113 return;
114
115 xid = get_xid();
116 rc = server->ops->query_server_interfaces(xid, tcon, false);
117 free_xid(xid);
118
119 if (rc) {
120 if (rc == -EOPNOTSUPP)
121 return;
122
123 cifs_dbg(FYI, "%s: failed to query server interfaces: %d\n",
124 __func__, rc);
125 }
126
127 queue_delayed_work(cifsiod_wq, &tcon->query_interfaces,
128 (SMB_INTERFACE_POLL_INTERVAL * HZ));
129 }
130
131 /*
132 * Update the tcpStatus for the server.
133 * This is used to signal the cifsd thread to call cifs_reconnect
134 * ONLY cifsd thread should call cifs_reconnect. For any other
135 * thread, use this function
136 *
137 * @server: the tcp ses for which reconnect is needed
138 * @all_channels: if this needs to be done for all channels
139 */
140 void
cifs_signal_cifsd_for_reconnect(struct TCP_Server_Info * server,bool all_channels)141 cifs_signal_cifsd_for_reconnect(struct TCP_Server_Info *server,
142 bool all_channels)
143 {
144 struct TCP_Server_Info *pserver;
145 struct cifs_ses *ses;
146 int i;
147
148 /* If server is a channel, select the primary channel */
149 pserver = SERVER_IS_CHAN(server) ? server->primary_server : server;
150
151 /* if we need to signal just this channel */
152 if (!all_channels) {
153 spin_lock(&server->srv_lock);
154 if (server->tcpStatus != CifsExiting)
155 server->tcpStatus = CifsNeedReconnect;
156 spin_unlock(&server->srv_lock);
157 return;
158 }
159
160 spin_lock(&cifs_tcp_ses_lock);
161 list_for_each_entry(ses, &pserver->smb_ses_list, smb_ses_list) {
162 if (cifs_ses_exiting(ses))
163 continue;
164 spin_lock(&ses->chan_lock);
165 for (i = 0; i < ses->chan_count; i++) {
166 if (!ses->chans[i].server)
167 continue;
168
169 spin_lock(&ses->chans[i].server->srv_lock);
170 if (ses->chans[i].server->tcpStatus != CifsExiting)
171 ses->chans[i].server->tcpStatus = CifsNeedReconnect;
172 spin_unlock(&ses->chans[i].server->srv_lock);
173 }
174 spin_unlock(&ses->chan_lock);
175 }
176 spin_unlock(&cifs_tcp_ses_lock);
177 }
178
179 /*
180 * Mark all sessions and tcons for reconnect.
181 * IMPORTANT: make sure that this gets called only from
182 * cifsd thread. For any other thread, use
183 * cifs_signal_cifsd_for_reconnect
184 *
185 * @server: the tcp ses for which reconnect is needed
186 * @server needs to be previously set to CifsNeedReconnect.
187 * @mark_smb_session: whether even sessions need to be marked
188 */
189 void
cifs_mark_tcp_ses_conns_for_reconnect(struct TCP_Server_Info * server,bool mark_smb_session)190 cifs_mark_tcp_ses_conns_for_reconnect(struct TCP_Server_Info *server,
191 bool mark_smb_session)
192 {
193 struct TCP_Server_Info *pserver;
194 struct cifs_ses *ses, *nses;
195 struct cifs_tcon *tcon;
196
197 /*
198 * before reconnecting the tcp session, mark the smb session (uid) and the tid bad so they
199 * are not used until reconnected.
200 */
201 cifs_dbg(FYI, "%s: marking necessary sessions and tcons for reconnect\n", __func__);
202
203 /* If server is a channel, select the primary channel */
204 pserver = SERVER_IS_CHAN(server) ? server->primary_server : server;
205
206 /*
207 * if the server has been marked for termination, there is a
208 * chance that the remaining channels all need reconnect. To be
209 * on the safer side, mark the session and trees for reconnect
210 * for this scenario. This might cause a few redundant session
211 * setup and tree connect requests, but it is better than not doing
212 * a tree connect when needed, and all following requests failing
213 */
214 if (server->terminate) {
215 mark_smb_session = true;
216 server = pserver;
217 }
218
219 spin_lock(&cifs_tcp_ses_lock);
220 list_for_each_entry_safe(ses, nses, &pserver->smb_ses_list, smb_ses_list) {
221 spin_lock(&ses->ses_lock);
222 if (ses->ses_status == SES_EXITING) {
223 spin_unlock(&ses->ses_lock);
224 continue;
225 }
226 spin_unlock(&ses->ses_lock);
227
228 spin_lock(&ses->chan_lock);
229 if (cifs_ses_get_chan_index(ses, server) ==
230 CIFS_INVAL_CHAN_INDEX) {
231 spin_unlock(&ses->chan_lock);
232 continue;
233 }
234
235 if (!cifs_chan_is_iface_active(ses, server)) {
236 spin_unlock(&ses->chan_lock);
237 cifs_chan_update_iface(ses, server);
238 spin_lock(&ses->chan_lock);
239 }
240
241 if (!mark_smb_session && cifs_chan_needs_reconnect(ses, server)) {
242 spin_unlock(&ses->chan_lock);
243 continue;
244 }
245
246 if (mark_smb_session)
247 CIFS_SET_ALL_CHANS_NEED_RECONNECT(ses);
248 else
249 cifs_chan_set_need_reconnect(ses, server);
250
251 cifs_dbg(FYI, "%s: channel connect bitmap: 0x%lx\n",
252 __func__, ses->chans_need_reconnect);
253
254 /* If all channels need reconnect, then tcon needs reconnect */
255 if (!mark_smb_session && !CIFS_ALL_CHANS_NEED_RECONNECT(ses)) {
256 spin_unlock(&ses->chan_lock);
257 continue;
258 }
259 spin_unlock(&ses->chan_lock);
260
261 spin_lock(&ses->ses_lock);
262 ses->ses_status = SES_NEED_RECON;
263 spin_unlock(&ses->ses_lock);
264
265 list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
266 tcon->need_reconnect = true;
267 spin_lock(&tcon->tc_lock);
268 tcon->status = TID_NEED_RECON;
269 spin_unlock(&tcon->tc_lock);
270
271 cancel_delayed_work(&tcon->query_interfaces);
272 }
273 if (ses->tcon_ipc) {
274 ses->tcon_ipc->need_reconnect = true;
275 spin_lock(&ses->tcon_ipc->tc_lock);
276 ses->tcon_ipc->status = TID_NEED_RECON;
277 spin_unlock(&ses->tcon_ipc->tc_lock);
278 }
279 }
280 spin_unlock(&cifs_tcp_ses_lock);
281 }
282
283 static void
cifs_abort_connection(struct TCP_Server_Info * server)284 cifs_abort_connection(struct TCP_Server_Info *server)
285 {
286 struct mid_q_entry *mid, *nmid;
287 struct list_head retry_list;
288
289 server->maxBuf = 0;
290 server->max_read = 0;
291
292 /* do not want to be sending data on a socket we are freeing */
293 cifs_dbg(FYI, "%s: tearing down socket\n", __func__);
294 cifs_server_lock(server);
295 if (server->ssocket) {
296 cifs_dbg(FYI, "State: 0x%x Flags: 0x%lx\n", server->ssocket->state,
297 server->ssocket->flags);
298 kernel_sock_shutdown(server->ssocket, SHUT_WR);
299 cifs_dbg(FYI, "Post shutdown state: 0x%x Flags: 0x%lx\n", server->ssocket->state,
300 server->ssocket->flags);
301 sock_release(server->ssocket);
302 server->ssocket = NULL;
303 }
304 server->sequence_number = 0;
305 server->session_estab = false;
306 kfree_sensitive(server->session_key.response);
307 server->session_key.response = NULL;
308 server->session_key.len = 0;
309 server->lstrp = jiffies;
310
311 /* mark submitted MIDs for retry and issue callback */
312 INIT_LIST_HEAD(&retry_list);
313 cifs_dbg(FYI, "%s: moving mids to private list\n", __func__);
314 spin_lock(&server->mid_lock);
315 list_for_each_entry_safe(mid, nmid, &server->pending_mid_q, qhead) {
316 kref_get(&mid->refcount);
317 if (mid->mid_state == MID_REQUEST_SUBMITTED)
318 mid->mid_state = MID_RETRY_NEEDED;
319 list_move(&mid->qhead, &retry_list);
320 mid->mid_flags |= MID_DELETED;
321 }
322 spin_unlock(&server->mid_lock);
323 cifs_server_unlock(server);
324
325 cifs_dbg(FYI, "%s: issuing mid callbacks\n", __func__);
326 list_for_each_entry_safe(mid, nmid, &retry_list, qhead) {
327 list_del_init(&mid->qhead);
328 mid->callback(mid);
329 release_mid(mid);
330 }
331
332 if (cifs_rdma_enabled(server)) {
333 cifs_server_lock(server);
334 smbd_destroy(server);
335 cifs_server_unlock(server);
336 }
337 }
338
cifs_tcp_ses_needs_reconnect(struct TCP_Server_Info * server,int num_targets)339 static bool cifs_tcp_ses_needs_reconnect(struct TCP_Server_Info *server, int num_targets)
340 {
341 spin_lock(&server->srv_lock);
342 server->nr_targets = num_targets;
343 if (server->tcpStatus == CifsExiting) {
344 /* the demux thread will exit normally next time through the loop */
345 spin_unlock(&server->srv_lock);
346 wake_up(&server->response_q);
347 return false;
348 }
349
350 cifs_dbg(FYI, "Mark tcp session as need reconnect\n");
351 trace_smb3_reconnect(server->CurrentMid, server->conn_id,
352 server->hostname);
353 server->tcpStatus = CifsNeedReconnect;
354
355 spin_unlock(&server->srv_lock);
356 return true;
357 }
358
359 /*
360 * cifs tcp session reconnection
361 *
362 * mark tcp session as reconnecting so temporarily locked
363 * mark all smb sessions as reconnecting for tcp session
364 * reconnect tcp session
365 * wake up waiters on reconnection? - (not needed currently)
366 *
367 * if mark_smb_session is passed as true, unconditionally mark
368 * the smb session (and tcon) for reconnect as well. This value
369 * doesn't really matter for non-multichannel scenario.
370 *
371 */
__cifs_reconnect(struct TCP_Server_Info * server,bool mark_smb_session)372 static int __cifs_reconnect(struct TCP_Server_Info *server,
373 bool mark_smb_session)
374 {
375 int rc = 0;
376
377 if (!cifs_tcp_ses_needs_reconnect(server, 1))
378 return 0;
379
380 cifs_mark_tcp_ses_conns_for_reconnect(server, mark_smb_session);
381
382 cifs_abort_connection(server);
383
384 do {
385 try_to_freeze();
386 cifs_server_lock(server);
387
388 if (!cifs_swn_set_server_dstaddr(server)) {
389 /* resolve the hostname again to make sure that IP address is up-to-date */
390 rc = reconn_set_ipaddr_from_hostname(server);
391 cifs_dbg(FYI, "%s: reconn_set_ipaddr_from_hostname: rc=%d\n", __func__, rc);
392 }
393
394 if (cifs_rdma_enabled(server))
395 rc = smbd_reconnect(server);
396 else
397 rc = generic_ip_connect(server);
398 if (rc) {
399 cifs_server_unlock(server);
400 cifs_dbg(FYI, "%s: reconnect error %d\n", __func__, rc);
401 msleep(3000);
402 } else {
403 atomic_inc(&tcpSesReconnectCount);
404 set_credits(server, 1);
405 spin_lock(&server->srv_lock);
406 if (server->tcpStatus != CifsExiting)
407 server->tcpStatus = CifsNeedNegotiate;
408 spin_unlock(&server->srv_lock);
409 cifs_swn_reset_server_dstaddr(server);
410 cifs_server_unlock(server);
411 mod_delayed_work(cifsiod_wq, &server->reconnect, 0);
412 }
413 } while (server->tcpStatus == CifsNeedReconnect);
414
415 spin_lock(&server->srv_lock);
416 if (server->tcpStatus == CifsNeedNegotiate)
417 mod_delayed_work(cifsiod_wq, &server->echo, 0);
418 spin_unlock(&server->srv_lock);
419
420 wake_up(&server->response_q);
421 return rc;
422 }
423
424 #ifdef CONFIG_CIFS_DFS_UPCALL
__reconnect_target_locked(struct TCP_Server_Info * server,const char * target)425 static int __reconnect_target_locked(struct TCP_Server_Info *server,
426 const char *target)
427 {
428 int rc;
429 char *hostname;
430
431 if (!cifs_swn_set_server_dstaddr(server)) {
432 if (server->hostname != target) {
433 hostname = extract_hostname(target);
434 if (!IS_ERR(hostname)) {
435 spin_lock(&server->srv_lock);
436 kfree(server->hostname);
437 server->hostname = hostname;
438 spin_unlock(&server->srv_lock);
439 } else {
440 cifs_dbg(FYI, "%s: couldn't extract hostname or address from dfs target: %ld\n",
441 __func__, PTR_ERR(hostname));
442 cifs_dbg(FYI, "%s: default to last target server: %s\n", __func__,
443 server->hostname);
444 }
445 }
446 /* resolve the hostname again to make sure that IP address is up-to-date. */
447 rc = reconn_set_ipaddr_from_hostname(server);
448 cifs_dbg(FYI, "%s: reconn_set_ipaddr_from_hostname: rc=%d\n", __func__, rc);
449 }
450 /* Reconnect the socket */
451 if (cifs_rdma_enabled(server))
452 rc = smbd_reconnect(server);
453 else
454 rc = generic_ip_connect(server);
455
456 return rc;
457 }
458
reconnect_target_locked(struct TCP_Server_Info * server,struct dfs_cache_tgt_list * tl,struct dfs_cache_tgt_iterator ** target_hint)459 static int reconnect_target_locked(struct TCP_Server_Info *server,
460 struct dfs_cache_tgt_list *tl,
461 struct dfs_cache_tgt_iterator **target_hint)
462 {
463 struct dfs_cache_tgt_iterator *tit;
464 int rc;
465
466 *target_hint = NULL;
467
468 /* If dfs target list is empty, then reconnect to last server */
469 tit = dfs_cache_get_tgt_iterator(tl);
470 if (!tit)
471 return __reconnect_target_locked(server, server->hostname);
472
473 /* Otherwise, try every dfs target in @tl */
474 do {
475 const char *target = dfs_cache_get_tgt_name(tit);
476
477 spin_lock(&server->srv_lock);
478 if (server->tcpStatus != CifsNeedReconnect) {
479 spin_unlock(&server->srv_lock);
480 return -ECONNRESET;
481 }
482 spin_unlock(&server->srv_lock);
483 rc = __reconnect_target_locked(server, target);
484 if (!rc) {
485 *target_hint = tit;
486 break;
487 }
488 } while ((tit = dfs_cache_get_next_tgt(tl, tit)));
489 return rc;
490 }
491
reconnect_dfs_server(struct TCP_Server_Info * server)492 static int reconnect_dfs_server(struct TCP_Server_Info *server)
493 {
494 struct dfs_cache_tgt_iterator *target_hint = NULL;
495 const char *ref_path = server->leaf_fullpath + 1;
496 DFS_CACHE_TGT_LIST(tl);
497 int num_targets = 0;
498 int rc = 0;
499
500 /*
501 * Determine the number of dfs targets the referral path in @cifs_sb resolves to.
502 *
503 * smb2_reconnect() needs to know how long it should wait based upon the number of dfs
504 * targets (server->nr_targets). It's also possible that the cached referral was cleared
505 * through /proc/fs/cifs/dfscache or the target list is empty due to server settings after
506 * refreshing the referral, so, in this case, default it to 1.
507 */
508 if (!dfs_cache_noreq_find(ref_path, NULL, &tl))
509 num_targets = dfs_cache_get_nr_tgts(&tl);
510 if (!num_targets)
511 num_targets = 1;
512
513 if (!cifs_tcp_ses_needs_reconnect(server, num_targets))
514 return 0;
515
516 /*
517 * Unconditionally mark all sessions & tcons for reconnect as we might be connecting to a
518 * different server or share during failover. It could be improved by adding some logic to
519 * only do that in case it connects to a different server or share, though.
520 */
521 cifs_mark_tcp_ses_conns_for_reconnect(server, true);
522
523 cifs_abort_connection(server);
524
525 do {
526 try_to_freeze();
527 cifs_server_lock(server);
528
529 rc = reconnect_target_locked(server, &tl, &target_hint);
530 if (rc) {
531 /* Failed to reconnect socket */
532 cifs_server_unlock(server);
533 cifs_dbg(FYI, "%s: reconnect error %d\n", __func__, rc);
534 msleep(3000);
535 continue;
536 }
537 /*
538 * Socket was created. Update tcp session status to CifsNeedNegotiate so that a
539 * process waiting for reconnect will know it needs to re-establish session and tcon
540 * through the reconnected target server.
541 */
542 atomic_inc(&tcpSesReconnectCount);
543 set_credits(server, 1);
544 spin_lock(&server->srv_lock);
545 if (server->tcpStatus != CifsExiting)
546 server->tcpStatus = CifsNeedNegotiate;
547 spin_unlock(&server->srv_lock);
548 cifs_swn_reset_server_dstaddr(server);
549 cifs_server_unlock(server);
550 mod_delayed_work(cifsiod_wq, &server->reconnect, 0);
551 } while (server->tcpStatus == CifsNeedReconnect);
552
553 dfs_cache_noreq_update_tgthint(ref_path, target_hint);
554 dfs_cache_free_tgts(&tl);
555
556 /* Need to set up echo worker again once connection has been established */
557 spin_lock(&server->srv_lock);
558 if (server->tcpStatus == CifsNeedNegotiate)
559 mod_delayed_work(cifsiod_wq, &server->echo, 0);
560 spin_unlock(&server->srv_lock);
561
562 wake_up(&server->response_q);
563 return rc;
564 }
565
cifs_reconnect(struct TCP_Server_Info * server,bool mark_smb_session)566 int cifs_reconnect(struct TCP_Server_Info *server, bool mark_smb_session)
567 {
568 if (!server->leaf_fullpath)
569 return __cifs_reconnect(server, mark_smb_session);
570 return reconnect_dfs_server(server);
571 }
572 #else
cifs_reconnect(struct TCP_Server_Info * server,bool mark_smb_session)573 int cifs_reconnect(struct TCP_Server_Info *server, bool mark_smb_session)
574 {
575 return __cifs_reconnect(server, mark_smb_session);
576 }
577 #endif
578
579 static void
cifs_echo_request(struct work_struct * work)580 cifs_echo_request(struct work_struct *work)
581 {
582 int rc;
583 struct TCP_Server_Info *server = container_of(work,
584 struct TCP_Server_Info, echo.work);
585
586 /*
587 * We cannot send an echo if it is disabled.
588 * Also, no need to ping if we got a response recently.
589 */
590
591 if (server->tcpStatus == CifsNeedReconnect ||
592 server->tcpStatus == CifsExiting ||
593 server->tcpStatus == CifsNew ||
594 (server->ops->can_echo && !server->ops->can_echo(server)) ||
595 time_before(jiffies, server->lstrp + server->echo_interval - HZ))
596 goto requeue_echo;
597
598 rc = server->ops->echo ? server->ops->echo(server) : -ENOSYS;
599 cifs_server_dbg(FYI, "send echo request: rc = %d\n", rc);
600
601 /* Check witness registrations */
602 cifs_swn_check();
603
604 requeue_echo:
605 queue_delayed_work(cifsiod_wq, &server->echo, server->echo_interval);
606 }
607
608 static bool
allocate_buffers(struct TCP_Server_Info * server)609 allocate_buffers(struct TCP_Server_Info *server)
610 {
611 if (!server->bigbuf) {
612 server->bigbuf = (char *)cifs_buf_get();
613 if (!server->bigbuf) {
614 cifs_server_dbg(VFS, "No memory for large SMB response\n");
615 msleep(3000);
616 /* retry will check if exiting */
617 return false;
618 }
619 } else if (server->large_buf) {
620 /* we are reusing a dirty large buf, clear its start */
621 memset(server->bigbuf, 0, HEADER_SIZE(server));
622 }
623
624 if (!server->smallbuf) {
625 server->smallbuf = (char *)cifs_small_buf_get();
626 if (!server->smallbuf) {
627 cifs_server_dbg(VFS, "No memory for SMB response\n");
628 msleep(1000);
629 /* retry will check if exiting */
630 return false;
631 }
632 /* beginning of smb buffer is cleared in our buf_get */
633 } else {
634 /* if existing small buf clear beginning */
635 memset(server->smallbuf, 0, HEADER_SIZE(server));
636 }
637
638 return true;
639 }
640
641 static bool
server_unresponsive(struct TCP_Server_Info * server)642 server_unresponsive(struct TCP_Server_Info *server)
643 {
644 /*
645 * If we're in the process of mounting a share or reconnecting a session
646 * and the server abruptly shut down (e.g. socket wasn't closed, packet
647 * had been ACK'ed but no SMB response), don't wait longer than 20s to
648 * negotiate protocol.
649 */
650 spin_lock(&server->srv_lock);
651 if (server->tcpStatus == CifsInNegotiate &&
652 time_after(jiffies, server->lstrp + 20 * HZ)) {
653 spin_unlock(&server->srv_lock);
654 cifs_reconnect(server, false);
655 return true;
656 }
657 /*
658 * We need to wait 3 echo intervals to make sure we handle such
659 * situations right:
660 * 1s client sends a normal SMB request
661 * 2s client gets a response
662 * 30s echo workqueue job pops, and decides we got a response recently
663 * and don't need to send another
664 * ...
665 * 65s kernel_recvmsg times out, and we see that we haven't gotten
666 * a response in >60s.
667 */
668 if ((server->tcpStatus == CifsGood ||
669 server->tcpStatus == CifsNeedNegotiate) &&
670 (!server->ops->can_echo || server->ops->can_echo(server)) &&
671 time_after(jiffies, server->lstrp + 3 * server->echo_interval)) {
672 spin_unlock(&server->srv_lock);
673 cifs_server_dbg(VFS, "has not responded in %lu seconds. Reconnecting...\n",
674 (3 * server->echo_interval) / HZ);
675 cifs_reconnect(server, false);
676 return true;
677 }
678 spin_unlock(&server->srv_lock);
679
680 return false;
681 }
682
683 static inline bool
zero_credits(struct TCP_Server_Info * server)684 zero_credits(struct TCP_Server_Info *server)
685 {
686 int val;
687
688 spin_lock(&server->req_lock);
689 val = server->credits + server->echo_credits + server->oplock_credits;
690 if (server->in_flight == 0 && val == 0) {
691 spin_unlock(&server->req_lock);
692 return true;
693 }
694 spin_unlock(&server->req_lock);
695 return false;
696 }
697
698 static int
cifs_readv_from_socket(struct TCP_Server_Info * server,struct msghdr * smb_msg)699 cifs_readv_from_socket(struct TCP_Server_Info *server, struct msghdr *smb_msg)
700 {
701 int length = 0;
702 int total_read;
703
704 for (total_read = 0; msg_data_left(smb_msg); total_read += length) {
705 try_to_freeze();
706
707 /* reconnect if no credits and no requests in flight */
708 if (zero_credits(server)) {
709 cifs_reconnect(server, false);
710 return -ECONNABORTED;
711 }
712
713 if (server_unresponsive(server))
714 return -ECONNABORTED;
715 if (cifs_rdma_enabled(server) && server->smbd_conn)
716 length = smbd_recv(server->smbd_conn, smb_msg);
717 else
718 length = sock_recvmsg(server->ssocket, smb_msg, 0);
719
720 spin_lock(&server->srv_lock);
721 if (server->tcpStatus == CifsExiting) {
722 spin_unlock(&server->srv_lock);
723 return -ESHUTDOWN;
724 }
725
726 if (server->tcpStatus == CifsNeedReconnect) {
727 spin_unlock(&server->srv_lock);
728 cifs_reconnect(server, false);
729 return -ECONNABORTED;
730 }
731 spin_unlock(&server->srv_lock);
732
733 if (length == -ERESTARTSYS ||
734 length == -EAGAIN ||
735 length == -EINTR) {
736 /*
737 * Minimum sleep to prevent looping, allowing socket
738 * to clear and app threads to set tcpStatus
739 * CifsNeedReconnect if server hung.
740 */
741 usleep_range(1000, 2000);
742 length = 0;
743 continue;
744 }
745
746 if (length <= 0) {
747 cifs_dbg(FYI, "Received no data or error: %d\n", length);
748 cifs_reconnect(server, false);
749 return -ECONNABORTED;
750 }
751 }
752 return total_read;
753 }
754
755 int
cifs_read_from_socket(struct TCP_Server_Info * server,char * buf,unsigned int to_read)756 cifs_read_from_socket(struct TCP_Server_Info *server, char *buf,
757 unsigned int to_read)
758 {
759 struct msghdr smb_msg = {};
760 struct kvec iov = {.iov_base = buf, .iov_len = to_read};
761
762 iov_iter_kvec(&smb_msg.msg_iter, ITER_DEST, &iov, 1, to_read);
763
764 return cifs_readv_from_socket(server, &smb_msg);
765 }
766
767 ssize_t
cifs_discard_from_socket(struct TCP_Server_Info * server,size_t to_read)768 cifs_discard_from_socket(struct TCP_Server_Info *server, size_t to_read)
769 {
770 struct msghdr smb_msg = {};
771
772 /*
773 * iov_iter_discard already sets smb_msg.type and count and iov_offset
774 * and cifs_readv_from_socket sets msg_control and msg_controllen
775 * so little to initialize in struct msghdr
776 */
777 iov_iter_discard(&smb_msg.msg_iter, ITER_DEST, to_read);
778
779 return cifs_readv_from_socket(server, &smb_msg);
780 }
781
782 int
cifs_read_iter_from_socket(struct TCP_Server_Info * server,struct iov_iter * iter,unsigned int to_read)783 cifs_read_iter_from_socket(struct TCP_Server_Info *server, struct iov_iter *iter,
784 unsigned int to_read)
785 {
786 struct msghdr smb_msg = { .msg_iter = *iter };
787
788 iov_iter_truncate(&smb_msg.msg_iter, to_read);
789 return cifs_readv_from_socket(server, &smb_msg);
790 }
791
792 static bool
is_smb_response(struct TCP_Server_Info * server,unsigned char type)793 is_smb_response(struct TCP_Server_Info *server, unsigned char type)
794 {
795 /*
796 * The first byte big endian of the length field,
797 * is actually not part of the length but the type
798 * with the most common, zero, as regular data.
799 */
800 switch (type) {
801 case RFC1002_SESSION_MESSAGE:
802 /* Regular SMB response */
803 return true;
804 case RFC1002_SESSION_KEEP_ALIVE:
805 cifs_dbg(FYI, "RFC 1002 session keep alive\n");
806 break;
807 case RFC1002_POSITIVE_SESSION_RESPONSE:
808 cifs_dbg(FYI, "RFC 1002 positive session response\n");
809 break;
810 case RFC1002_NEGATIVE_SESSION_RESPONSE:
811 /*
812 * We get this from Windows 98 instead of an error on
813 * SMB negprot response.
814 */
815 cifs_dbg(FYI, "RFC 1002 negative session response\n");
816 /* give server a second to clean up */
817 msleep(1000);
818 /*
819 * Always try 445 first on reconnect since we get NACK
820 * on some if we ever connected to port 139 (the NACK
821 * is since we do not begin with RFC1001 session
822 * initialize frame).
823 */
824 cifs_set_port((struct sockaddr *)&server->dstaddr, CIFS_PORT);
825 cifs_reconnect(server, true);
826 break;
827 default:
828 cifs_server_dbg(VFS, "RFC 1002 unknown response type 0x%x\n", type);
829 cifs_reconnect(server, true);
830 }
831
832 return false;
833 }
834
835 void
dequeue_mid(struct mid_q_entry * mid,bool malformed)836 dequeue_mid(struct mid_q_entry *mid, bool malformed)
837 {
838 #ifdef CONFIG_CIFS_STATS2
839 mid->when_received = jiffies;
840 #endif
841 spin_lock(&mid->server->mid_lock);
842 if (!malformed)
843 mid->mid_state = MID_RESPONSE_RECEIVED;
844 else
845 mid->mid_state = MID_RESPONSE_MALFORMED;
846 /*
847 * Trying to handle/dequeue a mid after the send_recv()
848 * function has finished processing it is a bug.
849 */
850 if (mid->mid_flags & MID_DELETED) {
851 spin_unlock(&mid->server->mid_lock);
852 pr_warn_once("trying to dequeue a deleted mid\n");
853 } else {
854 list_del_init(&mid->qhead);
855 mid->mid_flags |= MID_DELETED;
856 spin_unlock(&mid->server->mid_lock);
857 }
858 }
859
860 static unsigned int
smb2_get_credits_from_hdr(char * buffer,struct TCP_Server_Info * server)861 smb2_get_credits_from_hdr(char *buffer, struct TCP_Server_Info *server)
862 {
863 struct smb2_hdr *shdr = (struct smb2_hdr *)buffer;
864
865 /*
866 * SMB1 does not use credits.
867 */
868 if (is_smb1(server))
869 return 0;
870
871 return le16_to_cpu(shdr->CreditRequest);
872 }
873
874 static void
handle_mid(struct mid_q_entry * mid,struct TCP_Server_Info * server,char * buf,int malformed)875 handle_mid(struct mid_q_entry *mid, struct TCP_Server_Info *server,
876 char *buf, int malformed)
877 {
878 if (server->ops->check_trans2 &&
879 server->ops->check_trans2(mid, server, buf, malformed))
880 return;
881 mid->credits_received = smb2_get_credits_from_hdr(buf, server);
882 mid->resp_buf = buf;
883 mid->large_buf = server->large_buf;
884 /* Was previous buf put in mpx struct for multi-rsp? */
885 if (!mid->multiRsp) {
886 /* smb buffer will be freed by user thread */
887 if (server->large_buf)
888 server->bigbuf = NULL;
889 else
890 server->smallbuf = NULL;
891 }
892 dequeue_mid(mid, malformed);
893 }
894
895 int
cifs_enable_signing(struct TCP_Server_Info * server,bool mnt_sign_required)896 cifs_enable_signing(struct TCP_Server_Info *server, bool mnt_sign_required)
897 {
898 bool srv_sign_required = server->sec_mode & server->vals->signing_required;
899 bool srv_sign_enabled = server->sec_mode & server->vals->signing_enabled;
900 bool mnt_sign_enabled;
901
902 /*
903 * Is signing required by mnt options? If not then check
904 * global_secflags to see if it is there.
905 */
906 if (!mnt_sign_required)
907 mnt_sign_required = ((global_secflags & CIFSSEC_MUST_SIGN) ==
908 CIFSSEC_MUST_SIGN);
909
910 /*
911 * If signing is required then it's automatically enabled too,
912 * otherwise, check to see if the secflags allow it.
913 */
914 mnt_sign_enabled = mnt_sign_required ? mnt_sign_required :
915 (global_secflags & CIFSSEC_MAY_SIGN);
916
917 /* If server requires signing, does client allow it? */
918 if (srv_sign_required) {
919 if (!mnt_sign_enabled) {
920 cifs_dbg(VFS, "Server requires signing, but it's disabled in SecurityFlags!\n");
921 return -EOPNOTSUPP;
922 }
923 server->sign = true;
924 }
925
926 /* If client requires signing, does server allow it? */
927 if (mnt_sign_required) {
928 if (!srv_sign_enabled) {
929 cifs_dbg(VFS, "Server does not support signing!\n");
930 return -EOPNOTSUPP;
931 }
932 server->sign = true;
933 }
934
935 if (cifs_rdma_enabled(server) && server->sign)
936 cifs_dbg(VFS, "Signing is enabled, and RDMA read/write will be disabled\n");
937
938 return 0;
939 }
940
941 static noinline_for_stack void
clean_demultiplex_info(struct TCP_Server_Info * server)942 clean_demultiplex_info(struct TCP_Server_Info *server)
943 {
944 int length;
945
946 /* take it off the list, if it's not already */
947 spin_lock(&server->srv_lock);
948 list_del_init(&server->tcp_ses_list);
949 spin_unlock(&server->srv_lock);
950
951 cancel_delayed_work_sync(&server->echo);
952
953 spin_lock(&server->srv_lock);
954 server->tcpStatus = CifsExiting;
955 spin_unlock(&server->srv_lock);
956 wake_up_all(&server->response_q);
957
958 /* check if we have blocked requests that need to free */
959 spin_lock(&server->req_lock);
960 if (server->credits <= 0)
961 server->credits = 1;
962 spin_unlock(&server->req_lock);
963 /*
964 * Although there should not be any requests blocked on this queue it
965 * can not hurt to be paranoid and try to wake up requests that may
966 * haven been blocked when more than 50 at time were on the wire to the
967 * same server - they now will see the session is in exit state and get
968 * out of SendReceive.
969 */
970 wake_up_all(&server->request_q);
971 /* give those requests time to exit */
972 msleep(125);
973 if (cifs_rdma_enabled(server))
974 smbd_destroy(server);
975
976 if (server->ssocket) {
977 sock_release(server->ssocket);
978 server->ssocket = NULL;
979
980 /* Release netns reference for the socket. */
981 put_net(cifs_net_ns(server));
982 }
983
984 if (!list_empty(&server->pending_mid_q)) {
985 struct mid_q_entry *mid_entry;
986 struct list_head *tmp, *tmp2;
987 LIST_HEAD(dispose_list);
988
989 spin_lock(&server->mid_lock);
990 list_for_each_safe(tmp, tmp2, &server->pending_mid_q) {
991 mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
992 cifs_dbg(FYI, "Clearing mid %llu\n", mid_entry->mid);
993 kref_get(&mid_entry->refcount);
994 mid_entry->mid_state = MID_SHUTDOWN;
995 list_move(&mid_entry->qhead, &dispose_list);
996 mid_entry->mid_flags |= MID_DELETED;
997 }
998 spin_unlock(&server->mid_lock);
999
1000 /* now walk dispose list and issue callbacks */
1001 list_for_each_safe(tmp, tmp2, &dispose_list) {
1002 mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
1003 cifs_dbg(FYI, "Callback mid %llu\n", mid_entry->mid);
1004 list_del_init(&mid_entry->qhead);
1005 mid_entry->callback(mid_entry);
1006 release_mid(mid_entry);
1007 }
1008 /* 1/8th of sec is more than enough time for them to exit */
1009 msleep(125);
1010 }
1011
1012 if (!list_empty(&server->pending_mid_q)) {
1013 /*
1014 * mpx threads have not exited yet give them at least the smb
1015 * send timeout time for long ops.
1016 *
1017 * Due to delays on oplock break requests, we need to wait at
1018 * least 45 seconds before giving up on a request getting a
1019 * response and going ahead and killing cifsd.
1020 */
1021 cifs_dbg(FYI, "Wait for exit from demultiplex thread\n");
1022 msleep(46000);
1023 /*
1024 * If threads still have not exited they are probably never
1025 * coming home not much else we can do but free the memory.
1026 */
1027 }
1028
1029 /* Release netns reference for this server. */
1030 put_net(cifs_net_ns(server));
1031 kfree(server->leaf_fullpath);
1032 kfree(server->hostname);
1033 kfree(server);
1034
1035 length = atomic_dec_return(&tcpSesAllocCount);
1036 if (length > 0)
1037 mempool_resize(cifs_req_poolp, length + cifs_min_rcv);
1038 }
1039
1040 static int
standard_receive3(struct TCP_Server_Info * server,struct mid_q_entry * mid)1041 standard_receive3(struct TCP_Server_Info *server, struct mid_q_entry *mid)
1042 {
1043 int length;
1044 char *buf = server->smallbuf;
1045 unsigned int pdu_length = server->pdu_size;
1046
1047 /* make sure this will fit in a large buffer */
1048 if (pdu_length > CIFSMaxBufSize + MAX_HEADER_SIZE(server) -
1049 HEADER_PREAMBLE_SIZE(server)) {
1050 cifs_server_dbg(VFS, "SMB response too long (%u bytes)\n", pdu_length);
1051 cifs_reconnect(server, true);
1052 return -ECONNABORTED;
1053 }
1054
1055 /* switch to large buffer if too big for a small one */
1056 if (pdu_length > MAX_CIFS_SMALL_BUFFER_SIZE - 4) {
1057 server->large_buf = true;
1058 memcpy(server->bigbuf, buf, server->total_read);
1059 buf = server->bigbuf;
1060 }
1061
1062 /* now read the rest */
1063 length = cifs_read_from_socket(server, buf + HEADER_SIZE(server) - 1,
1064 pdu_length - MID_HEADER_SIZE(server));
1065
1066 if (length < 0)
1067 return length;
1068 server->total_read += length;
1069
1070 dump_smb(buf, server->total_read);
1071
1072 return cifs_handle_standard(server, mid);
1073 }
1074
1075 int
cifs_handle_standard(struct TCP_Server_Info * server,struct mid_q_entry * mid)1076 cifs_handle_standard(struct TCP_Server_Info *server, struct mid_q_entry *mid)
1077 {
1078 char *buf = server->large_buf ? server->bigbuf : server->smallbuf;
1079 int rc;
1080
1081 /*
1082 * We know that we received enough to get to the MID as we
1083 * checked the pdu_length earlier. Now check to see
1084 * if the rest of the header is OK.
1085 *
1086 * 48 bytes is enough to display the header and a little bit
1087 * into the payload for debugging purposes.
1088 */
1089 rc = server->ops->check_message(buf, server->total_read, server);
1090 if (rc)
1091 cifs_dump_mem("Bad SMB: ", buf,
1092 min_t(unsigned int, server->total_read, 48));
1093
1094 if (server->ops->is_session_expired &&
1095 server->ops->is_session_expired(buf)) {
1096 cifs_reconnect(server, true);
1097 return -1;
1098 }
1099
1100 if (server->ops->is_status_pending &&
1101 server->ops->is_status_pending(buf, server))
1102 return -1;
1103
1104 if (!mid)
1105 return rc;
1106
1107 handle_mid(mid, server, buf, rc);
1108 return 0;
1109 }
1110
1111 static void
smb2_add_credits_from_hdr(char * buffer,struct TCP_Server_Info * server)1112 smb2_add_credits_from_hdr(char *buffer, struct TCP_Server_Info *server)
1113 {
1114 struct smb2_hdr *shdr = (struct smb2_hdr *)buffer;
1115 int scredits, in_flight;
1116
1117 /*
1118 * SMB1 does not use credits.
1119 */
1120 if (is_smb1(server))
1121 return;
1122
1123 if (shdr->CreditRequest) {
1124 spin_lock(&server->req_lock);
1125 server->credits += le16_to_cpu(shdr->CreditRequest);
1126 scredits = server->credits;
1127 in_flight = server->in_flight;
1128 spin_unlock(&server->req_lock);
1129 wake_up(&server->request_q);
1130
1131 trace_smb3_hdr_credits(server->CurrentMid,
1132 server->conn_id, server->hostname, scredits,
1133 le16_to_cpu(shdr->CreditRequest), in_flight);
1134 cifs_server_dbg(FYI, "%s: added %u credits total=%d\n",
1135 __func__, le16_to_cpu(shdr->CreditRequest),
1136 scredits);
1137 }
1138 }
1139
1140
1141 static int
cifs_demultiplex_thread(void * p)1142 cifs_demultiplex_thread(void *p)
1143 {
1144 int i, num_mids, length;
1145 struct TCP_Server_Info *server = p;
1146 unsigned int pdu_length;
1147 unsigned int next_offset;
1148 char *buf = NULL;
1149 struct task_struct *task_to_wake = NULL;
1150 struct mid_q_entry *mids[MAX_COMPOUND];
1151 char *bufs[MAX_COMPOUND];
1152 unsigned int noreclaim_flag, num_io_timeout = 0;
1153 bool pending_reconnect = false;
1154
1155 noreclaim_flag = memalloc_noreclaim_save();
1156 cifs_dbg(FYI, "Demultiplex PID: %d\n", task_pid_nr(current));
1157
1158 length = atomic_inc_return(&tcpSesAllocCount);
1159 if (length > 1)
1160 mempool_resize(cifs_req_poolp, length + cifs_min_rcv);
1161
1162 set_freezable();
1163 allow_kernel_signal(SIGKILL);
1164 while (server->tcpStatus != CifsExiting) {
1165 if (try_to_freeze())
1166 continue;
1167
1168 if (!allocate_buffers(server))
1169 continue;
1170
1171 server->large_buf = false;
1172 buf = server->smallbuf;
1173 pdu_length = 4; /* enough to get RFC1001 header */
1174
1175 length = cifs_read_from_socket(server, buf, pdu_length);
1176 if (length < 0)
1177 continue;
1178
1179 if (is_smb1(server))
1180 server->total_read = length;
1181 else
1182 server->total_read = 0;
1183
1184 /*
1185 * The right amount was read from socket - 4 bytes,
1186 * so we can now interpret the length field.
1187 */
1188 pdu_length = get_rfc1002_length(buf);
1189
1190 cifs_dbg(FYI, "RFC1002 header 0x%x\n", pdu_length);
1191 if (!is_smb_response(server, buf[0]))
1192 continue;
1193
1194 pending_reconnect = false;
1195 next_pdu:
1196 server->pdu_size = pdu_length;
1197
1198 /* make sure we have enough to get to the MID */
1199 if (server->pdu_size < MID_HEADER_SIZE(server)) {
1200 cifs_server_dbg(VFS, "SMB response too short (%u bytes)\n",
1201 server->pdu_size);
1202 cifs_reconnect(server, true);
1203 continue;
1204 }
1205
1206 /* read down to the MID */
1207 length = cifs_read_from_socket(server,
1208 buf + HEADER_PREAMBLE_SIZE(server),
1209 MID_HEADER_SIZE(server));
1210 if (length < 0)
1211 continue;
1212 server->total_read += length;
1213
1214 if (server->ops->next_header) {
1215 if (server->ops->next_header(server, buf, &next_offset)) {
1216 cifs_dbg(VFS, "%s: malformed response (next_offset=%u)\n",
1217 __func__, next_offset);
1218 cifs_reconnect(server, true);
1219 continue;
1220 }
1221 if (next_offset)
1222 server->pdu_size = next_offset;
1223 }
1224
1225 memset(mids, 0, sizeof(mids));
1226 memset(bufs, 0, sizeof(bufs));
1227 num_mids = 0;
1228
1229 if (server->ops->is_transform_hdr &&
1230 server->ops->receive_transform &&
1231 server->ops->is_transform_hdr(buf)) {
1232 length = server->ops->receive_transform(server,
1233 mids,
1234 bufs,
1235 &num_mids);
1236 } else {
1237 mids[0] = server->ops->find_mid(server, buf);
1238 bufs[0] = buf;
1239 num_mids = 1;
1240
1241 if (!mids[0] || !mids[0]->receive)
1242 length = standard_receive3(server, mids[0]);
1243 else
1244 length = mids[0]->receive(server, mids[0]);
1245 }
1246
1247 if (length < 0) {
1248 for (i = 0; i < num_mids; i++)
1249 if (mids[i])
1250 release_mid(mids[i]);
1251 continue;
1252 }
1253
1254 if (server->ops->is_status_io_timeout &&
1255 server->ops->is_status_io_timeout(buf)) {
1256 num_io_timeout++;
1257 if (num_io_timeout > MAX_STATUS_IO_TIMEOUT) {
1258 cifs_server_dbg(VFS,
1259 "Number of request timeouts exceeded %d. Reconnecting",
1260 MAX_STATUS_IO_TIMEOUT);
1261
1262 pending_reconnect = true;
1263 num_io_timeout = 0;
1264 }
1265 }
1266
1267 server->lstrp = jiffies;
1268
1269 for (i = 0; i < num_mids; i++) {
1270 if (mids[i] != NULL) {
1271 mids[i]->resp_buf_size = server->pdu_size;
1272
1273 if (bufs[i] != NULL) {
1274 if (server->ops->is_network_name_deleted &&
1275 server->ops->is_network_name_deleted(bufs[i],
1276 server)) {
1277 cifs_server_dbg(FYI,
1278 "Share deleted. Reconnect needed");
1279 }
1280 }
1281
1282 if (!mids[i]->multiRsp || mids[i]->multiEnd)
1283 mids[i]->callback(mids[i]);
1284
1285 release_mid(mids[i]);
1286 } else if (server->ops->is_oplock_break &&
1287 server->ops->is_oplock_break(bufs[i],
1288 server)) {
1289 smb2_add_credits_from_hdr(bufs[i], server);
1290 cifs_dbg(FYI, "Received oplock break\n");
1291 } else {
1292 cifs_server_dbg(VFS, "No task to wake, unknown frame received! NumMids %d\n",
1293 atomic_read(&mid_count));
1294 cifs_dump_mem("Received Data is: ", bufs[i],
1295 HEADER_SIZE(server));
1296 smb2_add_credits_from_hdr(bufs[i], server);
1297 #ifdef CONFIG_CIFS_DEBUG2
1298 if (server->ops->dump_detail)
1299 server->ops->dump_detail(bufs[i],
1300 server);
1301 cifs_dump_mids(server);
1302 #endif /* CIFS_DEBUG2 */
1303 }
1304 }
1305
1306 if (pdu_length > server->pdu_size) {
1307 if (!allocate_buffers(server))
1308 continue;
1309 pdu_length -= server->pdu_size;
1310 server->total_read = 0;
1311 server->large_buf = false;
1312 buf = server->smallbuf;
1313 goto next_pdu;
1314 }
1315
1316 /* do this reconnect at the very end after processing all MIDs */
1317 if (pending_reconnect)
1318 cifs_reconnect(server, true);
1319
1320 } /* end while !EXITING */
1321
1322 /* buffer usually freed in free_mid - need to free it here on exit */
1323 cifs_buf_release(server->bigbuf);
1324 if (server->smallbuf) /* no sense logging a debug message if NULL */
1325 cifs_small_buf_release(server->smallbuf);
1326
1327 task_to_wake = xchg(&server->tsk, NULL);
1328 clean_demultiplex_info(server);
1329
1330 /* if server->tsk was NULL then wait for a signal before exiting */
1331 if (!task_to_wake) {
1332 set_current_state(TASK_INTERRUPTIBLE);
1333 while (!signal_pending(current)) {
1334 schedule();
1335 set_current_state(TASK_INTERRUPTIBLE);
1336 }
1337 set_current_state(TASK_RUNNING);
1338 }
1339
1340 memalloc_noreclaim_restore(noreclaim_flag);
1341 module_put_and_kthread_exit(0);
1342 }
1343
1344 int
cifs_ipaddr_cmp(struct sockaddr * srcaddr,struct sockaddr * rhs)1345 cifs_ipaddr_cmp(struct sockaddr *srcaddr, struct sockaddr *rhs)
1346 {
1347 struct sockaddr_in *saddr4 = (struct sockaddr_in *)srcaddr;
1348 struct sockaddr_in *vaddr4 = (struct sockaddr_in *)rhs;
1349 struct sockaddr_in6 *saddr6 = (struct sockaddr_in6 *)srcaddr;
1350 struct sockaddr_in6 *vaddr6 = (struct sockaddr_in6 *)rhs;
1351
1352 switch (srcaddr->sa_family) {
1353 case AF_UNSPEC:
1354 switch (rhs->sa_family) {
1355 case AF_UNSPEC:
1356 return 0;
1357 case AF_INET:
1358 case AF_INET6:
1359 return 1;
1360 default:
1361 return -1;
1362 }
1363 case AF_INET: {
1364 switch (rhs->sa_family) {
1365 case AF_UNSPEC:
1366 return -1;
1367 case AF_INET:
1368 return memcmp(saddr4, vaddr4,
1369 sizeof(struct sockaddr_in));
1370 case AF_INET6:
1371 return 1;
1372 default:
1373 return -1;
1374 }
1375 }
1376 case AF_INET6: {
1377 switch (rhs->sa_family) {
1378 case AF_UNSPEC:
1379 case AF_INET:
1380 return -1;
1381 case AF_INET6:
1382 return memcmp(saddr6,
1383 vaddr6,
1384 sizeof(struct sockaddr_in6));
1385 default:
1386 return -1;
1387 }
1388 }
1389 default:
1390 return -1; /* don't expect to be here */
1391 }
1392 }
1393
1394 /*
1395 * Returns true if srcaddr isn't specified and rhs isn't specified, or
1396 * if srcaddr is specified and matches the IP address of the rhs argument
1397 */
1398 bool
cifs_match_ipaddr(struct sockaddr * srcaddr,struct sockaddr * rhs)1399 cifs_match_ipaddr(struct sockaddr *srcaddr, struct sockaddr *rhs)
1400 {
1401 switch (srcaddr->sa_family) {
1402 case AF_UNSPEC:
1403 return (rhs->sa_family == AF_UNSPEC);
1404 case AF_INET: {
1405 struct sockaddr_in *saddr4 = (struct sockaddr_in *)srcaddr;
1406 struct sockaddr_in *vaddr4 = (struct sockaddr_in *)rhs;
1407
1408 return (saddr4->sin_addr.s_addr == vaddr4->sin_addr.s_addr);
1409 }
1410 case AF_INET6: {
1411 struct sockaddr_in6 *saddr6 = (struct sockaddr_in6 *)srcaddr;
1412 struct sockaddr_in6 *vaddr6 = (struct sockaddr_in6 *)rhs;
1413
1414 return (ipv6_addr_equal(&saddr6->sin6_addr, &vaddr6->sin6_addr)
1415 && saddr6->sin6_scope_id == vaddr6->sin6_scope_id);
1416 }
1417 default:
1418 WARN_ON(1);
1419 return false; /* don't expect to be here */
1420 }
1421 }
1422
1423 /*
1424 * If no port is specified in addr structure, we try to match with 445 port
1425 * and if it fails - with 139 ports. It should be called only if address
1426 * families of server and addr are equal.
1427 */
1428 static bool
match_port(struct TCP_Server_Info * server,struct sockaddr * addr)1429 match_port(struct TCP_Server_Info *server, struct sockaddr *addr)
1430 {
1431 __be16 port, *sport;
1432
1433 /* SMBDirect manages its own ports, don't match it here */
1434 if (server->rdma)
1435 return true;
1436
1437 switch (addr->sa_family) {
1438 case AF_INET:
1439 sport = &((struct sockaddr_in *) &server->dstaddr)->sin_port;
1440 port = ((struct sockaddr_in *) addr)->sin_port;
1441 break;
1442 case AF_INET6:
1443 sport = &((struct sockaddr_in6 *) &server->dstaddr)->sin6_port;
1444 port = ((struct sockaddr_in6 *) addr)->sin6_port;
1445 break;
1446 default:
1447 WARN_ON(1);
1448 return false;
1449 }
1450
1451 if (!port) {
1452 port = htons(CIFS_PORT);
1453 if (port == *sport)
1454 return true;
1455
1456 port = htons(RFC1001_PORT);
1457 }
1458
1459 return port == *sport;
1460 }
1461
match_server_address(struct TCP_Server_Info * server,struct sockaddr * addr)1462 static bool match_server_address(struct TCP_Server_Info *server, struct sockaddr *addr)
1463 {
1464 if (!cifs_match_ipaddr(addr, (struct sockaddr *)&server->dstaddr))
1465 return false;
1466
1467 return true;
1468 }
1469
1470 static bool
match_security(struct TCP_Server_Info * server,struct smb3_fs_context * ctx)1471 match_security(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
1472 {
1473 /*
1474 * The select_sectype function should either return the ctx->sectype
1475 * that was specified, or "Unspecified" if that sectype was not
1476 * compatible with the given NEGOTIATE request.
1477 */
1478 if (server->ops->select_sectype(server, ctx->sectype)
1479 == Unspecified)
1480 return false;
1481
1482 /*
1483 * Now check if signing mode is acceptable. No need to check
1484 * global_secflags at this point since if MUST_SIGN is set then
1485 * the server->sign had better be too.
1486 */
1487 if (ctx->sign && !server->sign)
1488 return false;
1489
1490 return true;
1491 }
1492
1493 /* this function must be called with srv_lock held */
match_server(struct TCP_Server_Info * server,struct smb3_fs_context * ctx,bool match_super)1494 static int match_server(struct TCP_Server_Info *server,
1495 struct smb3_fs_context *ctx,
1496 bool match_super)
1497 {
1498 struct sockaddr *addr = (struct sockaddr *)&ctx->dstaddr;
1499
1500 lockdep_assert_held(&server->srv_lock);
1501
1502 if (ctx->nosharesock)
1503 return 0;
1504
1505 /* this server does not share socket */
1506 if (server->nosharesock)
1507 return 0;
1508
1509 if (!match_super && (ctx->dfs_conn || server->dfs_conn))
1510 return 0;
1511
1512 /* If multidialect negotiation see if existing sessions match one */
1513 if (strcmp(ctx->vals->version_string, SMB3ANY_VERSION_STRING) == 0) {
1514 if (server->vals->protocol_id < SMB30_PROT_ID)
1515 return 0;
1516 } else if (strcmp(ctx->vals->version_string,
1517 SMBDEFAULT_VERSION_STRING) == 0) {
1518 if (server->vals->protocol_id < SMB21_PROT_ID)
1519 return 0;
1520 } else if ((server->vals != ctx->vals) || (server->ops != ctx->ops))
1521 return 0;
1522
1523 if (!net_eq(cifs_net_ns(server), current->nsproxy->net_ns))
1524 return 0;
1525
1526 if (!cifs_match_ipaddr((struct sockaddr *)&ctx->srcaddr,
1527 (struct sockaddr *)&server->srcaddr))
1528 return 0;
1529
1530 if (strcasecmp(server->hostname, ctx->server_hostname) ||
1531 !match_server_address(server, addr) ||
1532 !match_port(server, addr))
1533 return 0;
1534
1535 if (!match_security(server, ctx))
1536 return 0;
1537
1538 if (server->echo_interval != ctx->echo_interval * HZ)
1539 return 0;
1540
1541 if (server->rdma != ctx->rdma)
1542 return 0;
1543
1544 if (server->ignore_signature != ctx->ignore_signature)
1545 return 0;
1546
1547 if (server->min_offload != ctx->min_offload)
1548 return 0;
1549
1550 if (server->retrans != ctx->retrans)
1551 return 0;
1552
1553 return 1;
1554 }
1555
1556 struct TCP_Server_Info *
cifs_find_tcp_session(struct smb3_fs_context * ctx)1557 cifs_find_tcp_session(struct smb3_fs_context *ctx)
1558 {
1559 struct TCP_Server_Info *server;
1560
1561 spin_lock(&cifs_tcp_ses_lock);
1562 list_for_each_entry(server, &cifs_tcp_ses_list, tcp_ses_list) {
1563 spin_lock(&server->srv_lock);
1564 /*
1565 * Skip ses channels since they're only handled in lower layers
1566 * (e.g. cifs_send_recv).
1567 */
1568 if (SERVER_IS_CHAN(server) ||
1569 !match_server(server, ctx, false)) {
1570 spin_unlock(&server->srv_lock);
1571 continue;
1572 }
1573 spin_unlock(&server->srv_lock);
1574
1575 ++server->srv_count;
1576 spin_unlock(&cifs_tcp_ses_lock);
1577 cifs_dbg(FYI, "Existing tcp session with server found\n");
1578 return server;
1579 }
1580 spin_unlock(&cifs_tcp_ses_lock);
1581 return NULL;
1582 }
1583
1584 void
cifs_put_tcp_session(struct TCP_Server_Info * server,int from_reconnect)1585 cifs_put_tcp_session(struct TCP_Server_Info *server, int from_reconnect)
1586 {
1587 struct task_struct *task;
1588
1589 spin_lock(&cifs_tcp_ses_lock);
1590 if (--server->srv_count > 0) {
1591 spin_unlock(&cifs_tcp_ses_lock);
1592 return;
1593 }
1594
1595 /* srv_count can never go negative */
1596 WARN_ON(server->srv_count < 0);
1597
1598 list_del_init(&server->tcp_ses_list);
1599 spin_unlock(&cifs_tcp_ses_lock);
1600
1601 cancel_delayed_work_sync(&server->echo);
1602
1603 if (from_reconnect)
1604 /*
1605 * Avoid deadlock here: reconnect work calls
1606 * cifs_put_tcp_session() at its end. Need to be sure
1607 * that reconnect work does nothing with server pointer after
1608 * that step.
1609 */
1610 cancel_delayed_work(&server->reconnect);
1611 else
1612 cancel_delayed_work_sync(&server->reconnect);
1613
1614 /* For secondary channels, we pick up ref-count on the primary server */
1615 if (SERVER_IS_CHAN(server))
1616 cifs_put_tcp_session(server->primary_server, from_reconnect);
1617
1618 spin_lock(&server->srv_lock);
1619 server->tcpStatus = CifsExiting;
1620 spin_unlock(&server->srv_lock);
1621
1622 cifs_crypto_secmech_release(server);
1623
1624 kfree_sensitive(server->session_key.response);
1625 server->session_key.response = NULL;
1626 server->session_key.len = 0;
1627
1628 task = xchg(&server->tsk, NULL);
1629 if (task)
1630 send_sig(SIGKILL, task, 1);
1631 }
1632
1633 struct TCP_Server_Info *
cifs_get_tcp_session(struct smb3_fs_context * ctx,struct TCP_Server_Info * primary_server)1634 cifs_get_tcp_session(struct smb3_fs_context *ctx,
1635 struct TCP_Server_Info *primary_server)
1636 {
1637 struct TCP_Server_Info *tcp_ses = NULL;
1638 int rc;
1639
1640 cifs_dbg(FYI, "UNC: %s\n", ctx->UNC);
1641
1642 /* see if we already have a matching tcp_ses */
1643 tcp_ses = cifs_find_tcp_session(ctx);
1644 if (tcp_ses)
1645 return tcp_ses;
1646
1647 tcp_ses = kzalloc(sizeof(struct TCP_Server_Info), GFP_KERNEL);
1648 if (!tcp_ses) {
1649 rc = -ENOMEM;
1650 goto out_err;
1651 }
1652
1653 tcp_ses->hostname = kstrdup(ctx->server_hostname, GFP_KERNEL);
1654 if (!tcp_ses->hostname) {
1655 rc = -ENOMEM;
1656 goto out_err;
1657 }
1658
1659 if (ctx->leaf_fullpath) {
1660 tcp_ses->leaf_fullpath = kstrdup(ctx->leaf_fullpath, GFP_KERNEL);
1661 if (!tcp_ses->leaf_fullpath) {
1662 rc = -ENOMEM;
1663 goto out_err;
1664 }
1665 }
1666 if (ctx->dns_dom)
1667 strscpy(tcp_ses->dns_dom, ctx->dns_dom);
1668
1669 if (ctx->nosharesock)
1670 tcp_ses->nosharesock = true;
1671 tcp_ses->dfs_conn = ctx->dfs_conn;
1672
1673 tcp_ses->ops = ctx->ops;
1674 tcp_ses->vals = ctx->vals;
1675
1676 /* Grab netns reference for this server. */
1677 cifs_set_net_ns(tcp_ses, get_net(current->nsproxy->net_ns));
1678
1679 tcp_ses->conn_id = atomic_inc_return(&tcpSesNextId);
1680 tcp_ses->noblockcnt = ctx->rootfs;
1681 tcp_ses->noblocksnd = ctx->noblocksnd || ctx->rootfs;
1682 tcp_ses->noautotune = ctx->noautotune;
1683 tcp_ses->tcp_nodelay = ctx->sockopt_tcp_nodelay;
1684 tcp_ses->rdma = ctx->rdma;
1685 tcp_ses->in_flight = 0;
1686 tcp_ses->max_in_flight = 0;
1687 tcp_ses->credits = 1;
1688 if (primary_server) {
1689 spin_lock(&cifs_tcp_ses_lock);
1690 ++primary_server->srv_count;
1691 spin_unlock(&cifs_tcp_ses_lock);
1692 tcp_ses->primary_server = primary_server;
1693 }
1694 init_waitqueue_head(&tcp_ses->response_q);
1695 init_waitqueue_head(&tcp_ses->request_q);
1696 INIT_LIST_HEAD(&tcp_ses->pending_mid_q);
1697 mutex_init(&tcp_ses->_srv_mutex);
1698 memcpy(tcp_ses->workstation_RFC1001_name,
1699 ctx->source_rfc1001_name, RFC1001_NAME_LEN_WITH_NULL);
1700 memcpy(tcp_ses->server_RFC1001_name,
1701 ctx->target_rfc1001_name, RFC1001_NAME_LEN_WITH_NULL);
1702 tcp_ses->session_estab = false;
1703 tcp_ses->sequence_number = 0;
1704 tcp_ses->channel_sequence_num = 0; /* only tracked for primary channel */
1705 tcp_ses->reconnect_instance = 1;
1706 tcp_ses->lstrp = jiffies;
1707 tcp_ses->compression.requested = ctx->compress;
1708 spin_lock_init(&tcp_ses->req_lock);
1709 spin_lock_init(&tcp_ses->srv_lock);
1710 spin_lock_init(&tcp_ses->mid_lock);
1711 INIT_LIST_HEAD(&tcp_ses->tcp_ses_list);
1712 INIT_LIST_HEAD(&tcp_ses->smb_ses_list);
1713 INIT_DELAYED_WORK(&tcp_ses->echo, cifs_echo_request);
1714 INIT_DELAYED_WORK(&tcp_ses->reconnect, smb2_reconnect_server);
1715 mutex_init(&tcp_ses->reconnect_mutex);
1716 memcpy(&tcp_ses->srcaddr, &ctx->srcaddr,
1717 sizeof(tcp_ses->srcaddr));
1718 memcpy(&tcp_ses->dstaddr, &ctx->dstaddr,
1719 sizeof(tcp_ses->dstaddr));
1720 if (ctx->use_client_guid)
1721 memcpy(tcp_ses->client_guid, ctx->client_guid,
1722 SMB2_CLIENT_GUID_SIZE);
1723 else
1724 generate_random_uuid(tcp_ses->client_guid);
1725 /*
1726 * at this point we are the only ones with the pointer
1727 * to the struct since the kernel thread not created yet
1728 * no need to spinlock this init of tcpStatus or srv_count
1729 */
1730 tcp_ses->tcpStatus = CifsNew;
1731 ++tcp_ses->srv_count;
1732
1733 if (ctx->echo_interval >= SMB_ECHO_INTERVAL_MIN &&
1734 ctx->echo_interval <= SMB_ECHO_INTERVAL_MAX)
1735 tcp_ses->echo_interval = ctx->echo_interval * HZ;
1736 else
1737 tcp_ses->echo_interval = SMB_ECHO_INTERVAL_DEFAULT * HZ;
1738 if (tcp_ses->rdma) {
1739 #ifndef CONFIG_CIFS_SMB_DIRECT
1740 cifs_dbg(VFS, "CONFIG_CIFS_SMB_DIRECT is not enabled\n");
1741 rc = -ENOENT;
1742 goto out_err_crypto_release;
1743 #endif
1744 tcp_ses->smbd_conn = smbd_get_connection(
1745 tcp_ses, (struct sockaddr *)&ctx->dstaddr);
1746 if (tcp_ses->smbd_conn) {
1747 cifs_dbg(VFS, "RDMA transport established\n");
1748 rc = 0;
1749 goto smbd_connected;
1750 } else {
1751 rc = -ENOENT;
1752 goto out_err_crypto_release;
1753 }
1754 }
1755 rc = ip_connect(tcp_ses);
1756 if (rc < 0) {
1757 cifs_dbg(VFS, "Error connecting to socket. Aborting operation.\n");
1758 goto out_err_crypto_release;
1759 }
1760 smbd_connected:
1761 /*
1762 * since we're in a cifs function already, we know that
1763 * this will succeed. No need for try_module_get().
1764 */
1765 __module_get(THIS_MODULE);
1766 tcp_ses->tsk = kthread_run(cifs_demultiplex_thread,
1767 tcp_ses, "cifsd");
1768 if (IS_ERR(tcp_ses->tsk)) {
1769 rc = PTR_ERR(tcp_ses->tsk);
1770 cifs_dbg(VFS, "error %d create cifsd thread\n", rc);
1771 module_put(THIS_MODULE);
1772 goto out_err_crypto_release;
1773 }
1774 tcp_ses->min_offload = ctx->min_offload;
1775 tcp_ses->retrans = ctx->retrans;
1776 /*
1777 * at this point we are the only ones with the pointer
1778 * to the struct since the kernel thread not created yet
1779 * no need to spinlock this update of tcpStatus
1780 */
1781 spin_lock(&tcp_ses->srv_lock);
1782 tcp_ses->tcpStatus = CifsNeedNegotiate;
1783 spin_unlock(&tcp_ses->srv_lock);
1784
1785 if ((ctx->max_credits < 20) || (ctx->max_credits > 60000))
1786 tcp_ses->max_credits = SMB2_MAX_CREDITS_AVAILABLE;
1787 else
1788 tcp_ses->max_credits = ctx->max_credits;
1789
1790 tcp_ses->nr_targets = 1;
1791 tcp_ses->ignore_signature = ctx->ignore_signature;
1792 /* thread spawned, put it on the list */
1793 spin_lock(&cifs_tcp_ses_lock);
1794 list_add(&tcp_ses->tcp_ses_list, &cifs_tcp_ses_list);
1795 spin_unlock(&cifs_tcp_ses_lock);
1796
1797 /* queue echo request delayed work */
1798 queue_delayed_work(cifsiod_wq, &tcp_ses->echo, tcp_ses->echo_interval);
1799
1800 return tcp_ses;
1801
1802 out_err_crypto_release:
1803 cifs_crypto_secmech_release(tcp_ses);
1804
1805 /* Release netns reference for this server. */
1806 put_net(cifs_net_ns(tcp_ses));
1807
1808 out_err:
1809 if (tcp_ses) {
1810 if (SERVER_IS_CHAN(tcp_ses))
1811 cifs_put_tcp_session(tcp_ses->primary_server, false);
1812 kfree(tcp_ses->hostname);
1813 kfree(tcp_ses->leaf_fullpath);
1814 if (tcp_ses->ssocket) {
1815 sock_release(tcp_ses->ssocket);
1816 put_net(cifs_net_ns(tcp_ses));
1817 }
1818 kfree(tcp_ses);
1819 }
1820 return ERR_PTR(rc);
1821 }
1822
1823 /* this function must be called with ses_lock and chan_lock held */
match_session(struct cifs_ses * ses,struct smb3_fs_context * ctx,bool match_super)1824 static int match_session(struct cifs_ses *ses,
1825 struct smb3_fs_context *ctx,
1826 bool match_super)
1827 {
1828 if (ctx->sectype != Unspecified &&
1829 ctx->sectype != ses->sectype)
1830 return 0;
1831
1832 if (!match_super && ctx->dfs_root_ses != ses->dfs_root_ses)
1833 return 0;
1834
1835 /*
1836 * If an existing session is limited to less channels than
1837 * requested, it should not be reused
1838 */
1839 if (ses->chan_max < ctx->max_channels)
1840 return 0;
1841
1842 switch (ses->sectype) {
1843 case Kerberos:
1844 if (!uid_eq(ctx->cred_uid, ses->cred_uid))
1845 return 0;
1846 break;
1847 default:
1848 /* NULL username means anonymous session */
1849 if (ses->user_name == NULL) {
1850 if (!ctx->nullauth)
1851 return 0;
1852 break;
1853 }
1854
1855 /* anything else takes username/password */
1856 if (strncmp(ses->user_name,
1857 ctx->username ? ctx->username : "",
1858 CIFS_MAX_USERNAME_LEN))
1859 return 0;
1860 if ((ctx->username && strlen(ctx->username) != 0) &&
1861 ses->password != NULL) {
1862
1863 /* New mount can only share sessions with an existing mount if:
1864 * 1. Both password and password2 match, or
1865 * 2. password2 of the old mount matches password of the new mount
1866 * and password of the old mount matches password2 of the new
1867 * mount
1868 */
1869 if (ses->password2 != NULL && ctx->password2 != NULL) {
1870 if (!((strncmp(ses->password, ctx->password ?
1871 ctx->password : "", CIFS_MAX_PASSWORD_LEN) == 0 &&
1872 strncmp(ses->password2, ctx->password2,
1873 CIFS_MAX_PASSWORD_LEN) == 0) ||
1874 (strncmp(ses->password, ctx->password2,
1875 CIFS_MAX_PASSWORD_LEN) == 0 &&
1876 strncmp(ses->password2, ctx->password ?
1877 ctx->password : "", CIFS_MAX_PASSWORD_LEN) == 0)))
1878 return 0;
1879
1880 } else if ((ses->password2 == NULL && ctx->password2 != NULL) ||
1881 (ses->password2 != NULL && ctx->password2 == NULL)) {
1882 return 0;
1883
1884 } else {
1885 if (strncmp(ses->password, ctx->password ?
1886 ctx->password : "", CIFS_MAX_PASSWORD_LEN))
1887 return 0;
1888 }
1889 }
1890 }
1891
1892 if (strcmp(ctx->local_nls->charset, ses->local_nls->charset))
1893 return 0;
1894
1895 return 1;
1896 }
1897
1898 /**
1899 * cifs_setup_ipc - helper to setup the IPC tcon for the session
1900 * @ses: smb session to issue the request on
1901 * @ctx: the superblock configuration context to use for building the
1902 * new tree connection for the IPC (interprocess communication RPC)
1903 *
1904 * A new IPC connection is made and stored in the session
1905 * tcon_ipc. The IPC tcon has the same lifetime as the session.
1906 */
1907 static int
cifs_setup_ipc(struct cifs_ses * ses,struct smb3_fs_context * ctx)1908 cifs_setup_ipc(struct cifs_ses *ses, struct smb3_fs_context *ctx)
1909 {
1910 int rc = 0, xid;
1911 struct cifs_tcon *tcon;
1912 char unc[SERVER_NAME_LENGTH + sizeof("//x/IPC$")] = {0};
1913 bool seal = false;
1914 struct TCP_Server_Info *server = ses->server;
1915
1916 /*
1917 * If the mount request that resulted in the creation of the
1918 * session requires encryption, force IPC to be encrypted too.
1919 */
1920 if (ctx->seal) {
1921 if (server->capabilities & SMB2_GLOBAL_CAP_ENCRYPTION)
1922 seal = true;
1923 else {
1924 cifs_server_dbg(VFS,
1925 "IPC: server doesn't support encryption\n");
1926 return -EOPNOTSUPP;
1927 }
1928 }
1929
1930 /* no need to setup directory caching on IPC share, so pass in false */
1931 tcon = tcon_info_alloc(false, netfs_trace_tcon_ref_new_ipc);
1932 if (tcon == NULL)
1933 return -ENOMEM;
1934
1935 spin_lock(&server->srv_lock);
1936 scnprintf(unc, sizeof(unc), "\\\\%s\\IPC$", server->hostname);
1937 spin_unlock(&server->srv_lock);
1938
1939 xid = get_xid();
1940 tcon->ses = ses;
1941 tcon->ipc = true;
1942 tcon->seal = seal;
1943 rc = server->ops->tree_connect(xid, ses, unc, tcon, ctx->local_nls);
1944 free_xid(xid);
1945
1946 if (rc) {
1947 cifs_server_dbg(VFS, "failed to connect to IPC (rc=%d)\n", rc);
1948 tconInfoFree(tcon, netfs_trace_tcon_ref_free_ipc_fail);
1949 goto out;
1950 }
1951
1952 cifs_dbg(FYI, "IPC tcon rc=%d ipc tid=0x%x\n", rc, tcon->tid);
1953
1954 spin_lock(&tcon->tc_lock);
1955 tcon->status = TID_GOOD;
1956 spin_unlock(&tcon->tc_lock);
1957 ses->tcon_ipc = tcon;
1958 out:
1959 return rc;
1960 }
1961
1962 static struct cifs_ses *
cifs_find_smb_ses(struct TCP_Server_Info * server,struct smb3_fs_context * ctx)1963 cifs_find_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
1964 {
1965 struct cifs_ses *ses, *ret = NULL;
1966
1967 spin_lock(&cifs_tcp_ses_lock);
1968 list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) {
1969 spin_lock(&ses->ses_lock);
1970 if (ses->ses_status == SES_EXITING) {
1971 spin_unlock(&ses->ses_lock);
1972 continue;
1973 }
1974 spin_lock(&ses->chan_lock);
1975 if (match_session(ses, ctx, false)) {
1976 spin_unlock(&ses->chan_lock);
1977 spin_unlock(&ses->ses_lock);
1978 ret = ses;
1979 break;
1980 }
1981 spin_unlock(&ses->chan_lock);
1982 spin_unlock(&ses->ses_lock);
1983 }
1984 if (ret)
1985 cifs_smb_ses_inc_refcount(ret);
1986 spin_unlock(&cifs_tcp_ses_lock);
1987 return ret;
1988 }
1989
__cifs_put_smb_ses(struct cifs_ses * ses)1990 void __cifs_put_smb_ses(struct cifs_ses *ses)
1991 {
1992 struct TCP_Server_Info *server = ses->server;
1993 struct cifs_tcon *tcon;
1994 unsigned int xid;
1995 size_t i;
1996 bool do_logoff;
1997 int rc;
1998
1999 spin_lock(&cifs_tcp_ses_lock);
2000 spin_lock(&ses->ses_lock);
2001 cifs_dbg(FYI, "%s: id=0x%llx ses_count=%d ses_status=%u ipc=%s\n",
2002 __func__, ses->Suid, ses->ses_count, ses->ses_status,
2003 ses->tcon_ipc ? ses->tcon_ipc->tree_name : "none");
2004 if (ses->ses_status == SES_EXITING || --ses->ses_count > 0) {
2005 spin_unlock(&ses->ses_lock);
2006 spin_unlock(&cifs_tcp_ses_lock);
2007 return;
2008 }
2009 /* ses_count can never go negative */
2010 WARN_ON(ses->ses_count < 0);
2011
2012 spin_lock(&ses->chan_lock);
2013 cifs_chan_clear_need_reconnect(ses, server);
2014 spin_unlock(&ses->chan_lock);
2015
2016 do_logoff = ses->ses_status == SES_GOOD && server->ops->logoff;
2017 ses->ses_status = SES_EXITING;
2018 tcon = ses->tcon_ipc;
2019 ses->tcon_ipc = NULL;
2020 spin_unlock(&ses->ses_lock);
2021 spin_unlock(&cifs_tcp_ses_lock);
2022
2023 /*
2024 * On session close, the IPC is closed and the server must release all
2025 * tcons of the session. No need to send a tree disconnect here.
2026 *
2027 * Besides, it will make the server to not close durable and resilient
2028 * files on session close, as specified in MS-SMB2 3.3.5.6 Receiving an
2029 * SMB2 LOGOFF Request.
2030 */
2031 tconInfoFree(tcon, netfs_trace_tcon_ref_free_ipc);
2032 if (do_logoff) {
2033 xid = get_xid();
2034 rc = server->ops->logoff(xid, ses);
2035 cifs_server_dbg(FYI, "%s: Session Logoff: rc=%d\n",
2036 __func__, rc);
2037 _free_xid(xid);
2038 }
2039
2040 spin_lock(&cifs_tcp_ses_lock);
2041 list_del_init(&ses->smb_ses_list);
2042 spin_unlock(&cifs_tcp_ses_lock);
2043
2044 /* close any extra channels */
2045 for (i = 1; i < ses->chan_count; i++) {
2046 if (ses->chans[i].iface) {
2047 kref_put(&ses->chans[i].iface->refcount, release_iface);
2048 ses->chans[i].iface = NULL;
2049 }
2050 cifs_put_tcp_session(ses->chans[i].server, 0);
2051 ses->chans[i].server = NULL;
2052 }
2053
2054 /* we now account for primary channel in iface->refcount */
2055 if (ses->chans[0].iface) {
2056 kref_put(&ses->chans[0].iface->refcount, release_iface);
2057 ses->chans[0].server = NULL;
2058 }
2059
2060 sesInfoFree(ses);
2061 cifs_put_tcp_session(server, 0);
2062 }
2063
2064 #ifdef CONFIG_KEYS
2065
2066 /* strlen("cifs:a:") + CIFS_MAX_DOMAINNAME_LEN + 1 */
2067 #define CIFSCREDS_DESC_SIZE (7 + CIFS_MAX_DOMAINNAME_LEN + 1)
2068
2069 /* Populate username and pw fields from keyring if possible */
2070 static int
cifs_set_cifscreds(struct smb3_fs_context * ctx,struct cifs_ses * ses)2071 cifs_set_cifscreds(struct smb3_fs_context *ctx, struct cifs_ses *ses)
2072 {
2073 int rc = 0;
2074 int is_domain = 0;
2075 const char *delim, *payload;
2076 char *desc;
2077 ssize_t len;
2078 struct key *key;
2079 struct TCP_Server_Info *server = ses->server;
2080 struct sockaddr_in *sa;
2081 struct sockaddr_in6 *sa6;
2082 const struct user_key_payload *upayload;
2083
2084 desc = kmalloc(CIFSCREDS_DESC_SIZE, GFP_KERNEL);
2085 if (!desc)
2086 return -ENOMEM;
2087
2088 /* try to find an address key first */
2089 switch (server->dstaddr.ss_family) {
2090 case AF_INET:
2091 sa = (struct sockaddr_in *)&server->dstaddr;
2092 sprintf(desc, "cifs:a:%pI4", &sa->sin_addr.s_addr);
2093 break;
2094 case AF_INET6:
2095 sa6 = (struct sockaddr_in6 *)&server->dstaddr;
2096 sprintf(desc, "cifs:a:%pI6c", &sa6->sin6_addr.s6_addr);
2097 break;
2098 default:
2099 cifs_dbg(FYI, "Bad ss_family (%hu)\n",
2100 server->dstaddr.ss_family);
2101 rc = -EINVAL;
2102 goto out_err;
2103 }
2104
2105 cifs_dbg(FYI, "%s: desc=%s\n", __func__, desc);
2106 key = request_key(&key_type_logon, desc, "");
2107 if (IS_ERR(key)) {
2108 if (!ses->domainName) {
2109 cifs_dbg(FYI, "domainName is NULL\n");
2110 rc = PTR_ERR(key);
2111 goto out_err;
2112 }
2113
2114 /* didn't work, try to find a domain key */
2115 sprintf(desc, "cifs:d:%s", ses->domainName);
2116 cifs_dbg(FYI, "%s: desc=%s\n", __func__, desc);
2117 key = request_key(&key_type_logon, desc, "");
2118 if (IS_ERR(key)) {
2119 rc = PTR_ERR(key);
2120 goto out_err;
2121 }
2122 is_domain = 1;
2123 }
2124
2125 down_read(&key->sem);
2126 upayload = user_key_payload_locked(key);
2127 if (IS_ERR_OR_NULL(upayload)) {
2128 rc = upayload ? PTR_ERR(upayload) : -EINVAL;
2129 goto out_key_put;
2130 }
2131
2132 /* find first : in payload */
2133 payload = upayload->data;
2134 delim = strnchr(payload, upayload->datalen, ':');
2135 cifs_dbg(FYI, "payload=%s\n", payload);
2136 if (!delim) {
2137 cifs_dbg(FYI, "Unable to find ':' in payload (datalen=%d)\n",
2138 upayload->datalen);
2139 rc = -EINVAL;
2140 goto out_key_put;
2141 }
2142
2143 len = delim - payload;
2144 if (len > CIFS_MAX_USERNAME_LEN || len <= 0) {
2145 cifs_dbg(FYI, "Bad value from username search (len=%zd)\n",
2146 len);
2147 rc = -EINVAL;
2148 goto out_key_put;
2149 }
2150
2151 ctx->username = kstrndup(payload, len, GFP_KERNEL);
2152 if (!ctx->username) {
2153 cifs_dbg(FYI, "Unable to allocate %zd bytes for username\n",
2154 len);
2155 rc = -ENOMEM;
2156 goto out_key_put;
2157 }
2158 cifs_dbg(FYI, "%s: username=%s\n", __func__, ctx->username);
2159
2160 len = key->datalen - (len + 1);
2161 if (len > CIFS_MAX_PASSWORD_LEN || len <= 0) {
2162 cifs_dbg(FYI, "Bad len for password search (len=%zd)\n", len);
2163 rc = -EINVAL;
2164 kfree(ctx->username);
2165 ctx->username = NULL;
2166 goto out_key_put;
2167 }
2168
2169 ++delim;
2170 /* BB consider adding support for password2 (Key Rotation) for multiuser in future */
2171 ctx->password = kstrndup(delim, len, GFP_KERNEL);
2172 if (!ctx->password) {
2173 cifs_dbg(FYI, "Unable to allocate %zd bytes for password\n",
2174 len);
2175 rc = -ENOMEM;
2176 kfree(ctx->username);
2177 ctx->username = NULL;
2178 goto out_key_put;
2179 }
2180
2181 /*
2182 * If we have a domain key then we must set the domainName in the
2183 * for the request.
2184 */
2185 if (is_domain && ses->domainName) {
2186 ctx->domainname = kstrdup(ses->domainName, GFP_KERNEL);
2187 if (!ctx->domainname) {
2188 cifs_dbg(FYI, "Unable to allocate %zd bytes for domain\n",
2189 len);
2190 rc = -ENOMEM;
2191 kfree(ctx->username);
2192 ctx->username = NULL;
2193 kfree_sensitive(ctx->password);
2194 /* no need to free ctx->password2 since not allocated in this path */
2195 ctx->password = NULL;
2196 goto out_key_put;
2197 }
2198 }
2199
2200 strscpy(ctx->workstation_name, ses->workstation_name, sizeof(ctx->workstation_name));
2201
2202 out_key_put:
2203 up_read(&key->sem);
2204 key_put(key);
2205 out_err:
2206 kfree(desc);
2207 cifs_dbg(FYI, "%s: returning %d\n", __func__, rc);
2208 return rc;
2209 }
2210 #else /* ! CONFIG_KEYS */
2211 static inline int
cifs_set_cifscreds(struct smb3_fs_context * ctx,struct cifs_ses * ses)2212 cifs_set_cifscreds(struct smb3_fs_context *ctx __attribute__((unused)),
2213 struct cifs_ses *ses __attribute__((unused)))
2214 {
2215 return -ENOSYS;
2216 }
2217 #endif /* CONFIG_KEYS */
2218
2219 /**
2220 * cifs_get_smb_ses - get a session matching @ctx data from @server
2221 * @server: server to setup the session to
2222 * @ctx: superblock configuration context to use to setup the session
2223 *
2224 * This function assumes it is being called from cifs_mount() where we
2225 * already got a server reference (server refcount +1). See
2226 * cifs_get_tcon() for refcount explanations.
2227 */
2228 struct cifs_ses *
cifs_get_smb_ses(struct TCP_Server_Info * server,struct smb3_fs_context * ctx)2229 cifs_get_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
2230 {
2231 struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&server->dstaddr;
2232 struct sockaddr_in *addr = (struct sockaddr_in *)&server->dstaddr;
2233 struct cifs_ses *ses;
2234 unsigned int xid;
2235 int retries = 0;
2236 size_t len;
2237 int rc = 0;
2238
2239 xid = get_xid();
2240
2241 ses = cifs_find_smb_ses(server, ctx);
2242 if (ses) {
2243 cifs_dbg(FYI, "Existing smb sess found (status=%d)\n",
2244 ses->ses_status);
2245
2246 spin_lock(&ses->chan_lock);
2247 if (cifs_chan_needs_reconnect(ses, server)) {
2248 spin_unlock(&ses->chan_lock);
2249 cifs_dbg(FYI, "Session needs reconnect\n");
2250
2251 mutex_lock(&ses->session_mutex);
2252
2253 retry_old_session:
2254 rc = cifs_negotiate_protocol(xid, ses, server);
2255 if (rc) {
2256 mutex_unlock(&ses->session_mutex);
2257 /* problem -- put our ses reference */
2258 cifs_put_smb_ses(ses);
2259 free_xid(xid);
2260 return ERR_PTR(rc);
2261 }
2262
2263 rc = cifs_setup_session(xid, ses, server,
2264 ctx->local_nls);
2265 if (rc) {
2266 if (((rc == -EACCES) || (rc == -EKEYEXPIRED) ||
2267 (rc == -EKEYREVOKED)) && !retries && ses->password2) {
2268 retries++;
2269 cifs_dbg(FYI, "Session reconnect failed, retrying with alternate password\n");
2270 swap(ses->password, ses->password2);
2271 goto retry_old_session;
2272 }
2273 mutex_unlock(&ses->session_mutex);
2274 /* problem -- put our reference */
2275 cifs_put_smb_ses(ses);
2276 free_xid(xid);
2277 return ERR_PTR(rc);
2278 }
2279 mutex_unlock(&ses->session_mutex);
2280
2281 spin_lock(&ses->chan_lock);
2282 }
2283 spin_unlock(&ses->chan_lock);
2284
2285 /* existing SMB ses has a server reference already */
2286 cifs_put_tcp_session(server, 0);
2287 free_xid(xid);
2288 return ses;
2289 }
2290
2291 rc = -ENOMEM;
2292
2293 cifs_dbg(FYI, "Existing smb sess not found\n");
2294 ses = sesInfoAlloc();
2295 if (ses == NULL)
2296 goto get_ses_fail;
2297
2298 /* new SMB session uses our server ref */
2299 ses->server = server;
2300 if (server->dstaddr.ss_family == AF_INET6)
2301 sprintf(ses->ip_addr, "%pI6", &addr6->sin6_addr);
2302 else
2303 sprintf(ses->ip_addr, "%pI4", &addr->sin_addr);
2304
2305 if (ctx->username) {
2306 ses->user_name = kstrdup(ctx->username, GFP_KERNEL);
2307 if (!ses->user_name)
2308 goto get_ses_fail;
2309 }
2310
2311 /* ctx->password freed at unmount */
2312 if (ctx->password) {
2313 ses->password = kstrdup(ctx->password, GFP_KERNEL);
2314 if (!ses->password)
2315 goto get_ses_fail;
2316 }
2317 /* ctx->password freed at unmount */
2318 if (ctx->password2) {
2319 ses->password2 = kstrdup(ctx->password2, GFP_KERNEL);
2320 if (!ses->password2)
2321 goto get_ses_fail;
2322 }
2323 if (ctx->domainname) {
2324 ses->domainName = kstrdup(ctx->domainname, GFP_KERNEL);
2325 if (!ses->domainName)
2326 goto get_ses_fail;
2327
2328 len = strnlen(ctx->domainname, CIFS_MAX_DOMAINNAME_LEN);
2329 if (!cifs_netbios_name(ctx->domainname, len)) {
2330 ses->dns_dom = kstrndup(ctx->domainname,
2331 len, GFP_KERNEL);
2332 if (!ses->dns_dom)
2333 goto get_ses_fail;
2334 }
2335 }
2336
2337 strscpy(ses->workstation_name, ctx->workstation_name, sizeof(ses->workstation_name));
2338
2339 if (ctx->domainauto)
2340 ses->domainAuto = ctx->domainauto;
2341 ses->cred_uid = ctx->cred_uid;
2342 ses->linux_uid = ctx->linux_uid;
2343
2344 ses->sectype = ctx->sectype;
2345 ses->sign = ctx->sign;
2346
2347 /*
2348 *Explicitly marking upcall_target mount option for easier handling
2349 * by cifs_spnego.c and eventually cifs.upcall.c
2350 */
2351
2352 switch (ctx->upcall_target) {
2353 case UPTARGET_UNSPECIFIED: /* default to app */
2354 case UPTARGET_APP:
2355 ses->upcall_target = UPTARGET_APP;
2356 break;
2357 case UPTARGET_MOUNT:
2358 ses->upcall_target = UPTARGET_MOUNT;
2359 break;
2360 default:
2361 // should never happen
2362 ses->upcall_target = UPTARGET_APP;
2363 break;
2364 }
2365
2366 ses->local_nls = load_nls(ctx->local_nls->charset);
2367
2368 /* add server as first channel */
2369 spin_lock(&ses->chan_lock);
2370 ses->chans[0].server = server;
2371 ses->chan_count = 1;
2372 ses->chan_max = ctx->multichannel ? ctx->max_channels:1;
2373 ses->chans_need_reconnect = 1;
2374 spin_unlock(&ses->chan_lock);
2375
2376 retry_new_session:
2377 mutex_lock(&ses->session_mutex);
2378 rc = cifs_negotiate_protocol(xid, ses, server);
2379 if (!rc)
2380 rc = cifs_setup_session(xid, ses, server, ctx->local_nls);
2381 mutex_unlock(&ses->session_mutex);
2382
2383 /* each channel uses a different signing key */
2384 spin_lock(&ses->chan_lock);
2385 memcpy(ses->chans[0].signkey, ses->smb3signingkey,
2386 sizeof(ses->smb3signingkey));
2387 spin_unlock(&ses->chan_lock);
2388
2389 if (rc) {
2390 if (((rc == -EACCES) || (rc == -EKEYEXPIRED) ||
2391 (rc == -EKEYREVOKED)) && !retries && ses->password2) {
2392 retries++;
2393 cifs_dbg(FYI, "Session setup failed, retrying with alternate password\n");
2394 swap(ses->password, ses->password2);
2395 goto retry_new_session;
2396 } else
2397 goto get_ses_fail;
2398 }
2399
2400 /*
2401 * success, put it on the list and add it as first channel
2402 * note: the session becomes active soon after this. So you'll
2403 * need to lock before changing something in the session.
2404 */
2405 spin_lock(&cifs_tcp_ses_lock);
2406 ses->dfs_root_ses = ctx->dfs_root_ses;
2407 list_add(&ses->smb_ses_list, &server->smb_ses_list);
2408 spin_unlock(&cifs_tcp_ses_lock);
2409
2410 cifs_setup_ipc(ses, ctx);
2411
2412 free_xid(xid);
2413
2414 return ses;
2415
2416 get_ses_fail:
2417 sesInfoFree(ses);
2418 free_xid(xid);
2419 return ERR_PTR(rc);
2420 }
2421
2422 /* this function must be called with tc_lock held */
match_tcon(struct cifs_tcon * tcon,struct smb3_fs_context * ctx)2423 static int match_tcon(struct cifs_tcon *tcon, struct smb3_fs_context *ctx)
2424 {
2425 struct TCP_Server_Info *server = tcon->ses->server;
2426
2427 if (tcon->status == TID_EXITING)
2428 return 0;
2429
2430 if (tcon->origin_fullpath) {
2431 if (!ctx->source ||
2432 !dfs_src_pathname_equal(ctx->source,
2433 tcon->origin_fullpath))
2434 return 0;
2435 } else if (!server->leaf_fullpath &&
2436 strncmp(tcon->tree_name, ctx->UNC, MAX_TREE_SIZE)) {
2437 return 0;
2438 }
2439 if (tcon->seal != ctx->seal)
2440 return 0;
2441 if (tcon->snapshot_time != ctx->snapshot_time)
2442 return 0;
2443 if (tcon->handle_timeout != ctx->handle_timeout)
2444 return 0;
2445 if (tcon->no_lease != ctx->no_lease)
2446 return 0;
2447 if (tcon->nodelete != ctx->nodelete)
2448 return 0;
2449 return 1;
2450 }
2451
2452 static struct cifs_tcon *
cifs_find_tcon(struct cifs_ses * ses,struct smb3_fs_context * ctx)2453 cifs_find_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx)
2454 {
2455 struct cifs_tcon *tcon;
2456
2457 spin_lock(&cifs_tcp_ses_lock);
2458 list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
2459 spin_lock(&tcon->tc_lock);
2460 if (!match_tcon(tcon, ctx)) {
2461 spin_unlock(&tcon->tc_lock);
2462 continue;
2463 }
2464 ++tcon->tc_count;
2465 trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count,
2466 netfs_trace_tcon_ref_get_find);
2467 spin_unlock(&tcon->tc_lock);
2468 spin_unlock(&cifs_tcp_ses_lock);
2469 return tcon;
2470 }
2471 spin_unlock(&cifs_tcp_ses_lock);
2472 return NULL;
2473 }
2474
2475 void
cifs_put_tcon(struct cifs_tcon * tcon,enum smb3_tcon_ref_trace trace)2476 cifs_put_tcon(struct cifs_tcon *tcon, enum smb3_tcon_ref_trace trace)
2477 {
2478 unsigned int xid;
2479 struct cifs_ses *ses;
2480 LIST_HEAD(ses_list);
2481
2482 /*
2483 * IPC tcon share the lifetime of their session and are
2484 * destroyed in the session put function
2485 */
2486 if (tcon == NULL || tcon->ipc)
2487 return;
2488
2489 ses = tcon->ses;
2490 cifs_dbg(FYI, "%s: tc_count=%d\n", __func__, tcon->tc_count);
2491 spin_lock(&cifs_tcp_ses_lock);
2492 spin_lock(&tcon->tc_lock);
2493 trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count - 1, trace);
2494 if (--tcon->tc_count > 0) {
2495 spin_unlock(&tcon->tc_lock);
2496 spin_unlock(&cifs_tcp_ses_lock);
2497 return;
2498 }
2499
2500 /* tc_count can never go negative */
2501 WARN_ON(tcon->tc_count < 0);
2502
2503 list_del_init(&tcon->tcon_list);
2504 tcon->status = TID_EXITING;
2505 spin_unlock(&tcon->tc_lock);
2506 spin_unlock(&cifs_tcp_ses_lock);
2507
2508 /* cancel polling of interfaces */
2509 cancel_delayed_work_sync(&tcon->query_interfaces);
2510 #ifdef CONFIG_CIFS_DFS_UPCALL
2511 cancel_delayed_work_sync(&tcon->dfs_cache_work);
2512 list_replace_init(&tcon->dfs_ses_list, &ses_list);
2513 #endif
2514
2515 if (tcon->use_witness) {
2516 int rc;
2517
2518 rc = cifs_swn_unregister(tcon);
2519 if (rc < 0) {
2520 cifs_dbg(VFS, "%s: Failed to unregister for witness notifications: %d\n",
2521 __func__, rc);
2522 }
2523 }
2524
2525 xid = get_xid();
2526 if (ses->server->ops->tree_disconnect)
2527 ses->server->ops->tree_disconnect(xid, tcon);
2528 _free_xid(xid);
2529
2530 cifs_fscache_release_super_cookie(tcon);
2531 tconInfoFree(tcon, netfs_trace_tcon_ref_free);
2532 cifs_put_smb_ses(ses);
2533 #ifdef CONFIG_CIFS_DFS_UPCALL
2534 dfs_put_root_smb_sessions(&ses_list);
2535 #endif
2536 }
2537
2538 /**
2539 * cifs_get_tcon - get a tcon matching @ctx data from @ses
2540 * @ses: smb session to issue the request on
2541 * @ctx: the superblock configuration context to use for building the
2542 *
2543 * - tcon refcount is the number of mount points using the tcon.
2544 * - ses refcount is the number of tcon using the session.
2545 *
2546 * 1. This function assumes it is being called from cifs_mount() where
2547 * we already got a session reference (ses refcount +1).
2548 *
2549 * 2. Since we're in the context of adding a mount point, the end
2550 * result should be either:
2551 *
2552 * a) a new tcon already allocated with refcount=1 (1 mount point) and
2553 * its session refcount incremented (1 new tcon). This +1 was
2554 * already done in (1).
2555 *
2556 * b) an existing tcon with refcount+1 (add a mount point to it) and
2557 * identical ses refcount (no new tcon). Because of (1) we need to
2558 * decrement the ses refcount.
2559 */
2560 static struct cifs_tcon *
cifs_get_tcon(struct cifs_ses * ses,struct smb3_fs_context * ctx)2561 cifs_get_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx)
2562 {
2563 struct cifs_tcon *tcon;
2564 bool nohandlecache;
2565 int rc, xid;
2566
2567 tcon = cifs_find_tcon(ses, ctx);
2568 if (tcon) {
2569 /*
2570 * tcon has refcount already incremented but we need to
2571 * decrement extra ses reference gotten by caller (case b)
2572 */
2573 cifs_dbg(FYI, "Found match on UNC path\n");
2574 cifs_put_smb_ses(ses);
2575 return tcon;
2576 }
2577
2578 if (!ses->server->ops->tree_connect) {
2579 rc = -ENOSYS;
2580 goto out_fail;
2581 }
2582
2583 if (ses->server->dialect >= SMB20_PROT_ID &&
2584 (ses->server->capabilities & SMB2_GLOBAL_CAP_DIRECTORY_LEASING))
2585 nohandlecache = ctx->nohandlecache || !dir_cache_timeout;
2586 else
2587 nohandlecache = true;
2588 tcon = tcon_info_alloc(!nohandlecache, netfs_trace_tcon_ref_new);
2589 if (tcon == NULL) {
2590 rc = -ENOMEM;
2591 goto out_fail;
2592 }
2593 tcon->nohandlecache = nohandlecache;
2594
2595 if (ctx->snapshot_time) {
2596 if (ses->server->vals->protocol_id == 0) {
2597 cifs_dbg(VFS,
2598 "Use SMB2 or later for snapshot mount option\n");
2599 rc = -EOPNOTSUPP;
2600 goto out_fail;
2601 } else
2602 tcon->snapshot_time = ctx->snapshot_time;
2603 }
2604
2605 if (ctx->handle_timeout) {
2606 if (ses->server->vals->protocol_id == 0) {
2607 cifs_dbg(VFS,
2608 "Use SMB2.1 or later for handle timeout option\n");
2609 rc = -EOPNOTSUPP;
2610 goto out_fail;
2611 } else
2612 tcon->handle_timeout = ctx->handle_timeout;
2613 }
2614
2615 tcon->ses = ses;
2616 if (ctx->password) {
2617 tcon->password = kstrdup(ctx->password, GFP_KERNEL);
2618 if (!tcon->password) {
2619 rc = -ENOMEM;
2620 goto out_fail;
2621 }
2622 }
2623
2624 if (ctx->seal) {
2625 if (ses->server->vals->protocol_id == 0) {
2626 cifs_dbg(VFS,
2627 "SMB3 or later required for encryption\n");
2628 rc = -EOPNOTSUPP;
2629 goto out_fail;
2630 } else if (tcon->ses->server->capabilities &
2631 SMB2_GLOBAL_CAP_ENCRYPTION)
2632 tcon->seal = true;
2633 else {
2634 cifs_dbg(VFS, "Encryption is not supported on share\n");
2635 rc = -EOPNOTSUPP;
2636 goto out_fail;
2637 }
2638 }
2639
2640 if (ctx->linux_ext) {
2641 if (ses->server->posix_ext_supported) {
2642 tcon->posix_extensions = true;
2643 pr_warn_once("SMB3.11 POSIX Extensions are experimental\n");
2644 } else if ((ses->server->vals->protocol_id == SMB311_PROT_ID) ||
2645 (strcmp(ses->server->vals->version_string,
2646 SMB3ANY_VERSION_STRING) == 0) ||
2647 (strcmp(ses->server->vals->version_string,
2648 SMBDEFAULT_VERSION_STRING) == 0)) {
2649 cifs_dbg(VFS, "Server does not support mounting with posix SMB3.11 extensions\n");
2650 rc = -EOPNOTSUPP;
2651 goto out_fail;
2652 } else if (ses->server->vals->protocol_id == SMB10_PROT_ID)
2653 if (cap_unix(ses))
2654 cifs_dbg(FYI, "Unix Extensions requested on SMB1 mount\n");
2655 else {
2656 cifs_dbg(VFS, "SMB1 Unix Extensions not supported by server\n");
2657 rc = -EOPNOTSUPP;
2658 goto out_fail;
2659 } else {
2660 cifs_dbg(VFS,
2661 "Check vers= mount option. SMB3.11 disabled but required for POSIX extensions\n");
2662 rc = -EOPNOTSUPP;
2663 goto out_fail;
2664 }
2665 }
2666
2667 xid = get_xid();
2668 rc = ses->server->ops->tree_connect(xid, ses, ctx->UNC, tcon,
2669 ctx->local_nls);
2670 free_xid(xid);
2671 cifs_dbg(FYI, "Tcon rc = %d\n", rc);
2672 if (rc)
2673 goto out_fail;
2674
2675 tcon->use_persistent = false;
2676 /* check if SMB2 or later, CIFS does not support persistent handles */
2677 if (ctx->persistent) {
2678 if (ses->server->vals->protocol_id == 0) {
2679 cifs_dbg(VFS,
2680 "SMB3 or later required for persistent handles\n");
2681 rc = -EOPNOTSUPP;
2682 goto out_fail;
2683 } else if (ses->server->capabilities &
2684 SMB2_GLOBAL_CAP_PERSISTENT_HANDLES)
2685 tcon->use_persistent = true;
2686 else /* persistent handles requested but not supported */ {
2687 cifs_dbg(VFS,
2688 "Persistent handles not supported on share\n");
2689 rc = -EOPNOTSUPP;
2690 goto out_fail;
2691 }
2692 } else if ((tcon->capabilities & SMB2_SHARE_CAP_CONTINUOUS_AVAILABILITY)
2693 && (ses->server->capabilities & SMB2_GLOBAL_CAP_PERSISTENT_HANDLES)
2694 && (ctx->nopersistent == false)) {
2695 cifs_dbg(FYI, "enabling persistent handles\n");
2696 tcon->use_persistent = true;
2697 } else if (ctx->resilient) {
2698 if (ses->server->vals->protocol_id == 0) {
2699 cifs_dbg(VFS,
2700 "SMB2.1 or later required for resilient handles\n");
2701 rc = -EOPNOTSUPP;
2702 goto out_fail;
2703 }
2704 tcon->use_resilient = true;
2705 }
2706
2707 tcon->use_witness = false;
2708 if (IS_ENABLED(CONFIG_CIFS_SWN_UPCALL) && ctx->witness) {
2709 if (ses->server->vals->protocol_id >= SMB30_PROT_ID) {
2710 if (tcon->capabilities & SMB2_SHARE_CAP_CLUSTER) {
2711 /*
2712 * Set witness in use flag in first place
2713 * to retry registration in the echo task
2714 */
2715 tcon->use_witness = true;
2716 /* And try to register immediately */
2717 rc = cifs_swn_register(tcon);
2718 if (rc < 0) {
2719 cifs_dbg(VFS, "Failed to register for witness notifications: %d\n", rc);
2720 goto out_fail;
2721 }
2722 } else {
2723 /* TODO: try to extend for non-cluster uses (eg multichannel) */
2724 cifs_dbg(VFS, "witness requested on mount but no CLUSTER capability on share\n");
2725 rc = -EOPNOTSUPP;
2726 goto out_fail;
2727 }
2728 } else {
2729 cifs_dbg(VFS, "SMB3 or later required for witness option\n");
2730 rc = -EOPNOTSUPP;
2731 goto out_fail;
2732 }
2733 }
2734
2735 /* If the user really knows what they are doing they can override */
2736 if (tcon->share_flags & SMB2_SHAREFLAG_NO_CACHING) {
2737 if (ctx->cache_ro)
2738 cifs_dbg(VFS, "cache=ro requested on mount but NO_CACHING flag set on share\n");
2739 else if (ctx->cache_rw)
2740 cifs_dbg(VFS, "cache=singleclient requested on mount but NO_CACHING flag set on share\n");
2741 }
2742
2743 if (ctx->no_lease) {
2744 if (ses->server->vals->protocol_id == 0) {
2745 cifs_dbg(VFS,
2746 "SMB2 or later required for nolease option\n");
2747 rc = -EOPNOTSUPP;
2748 goto out_fail;
2749 } else
2750 tcon->no_lease = ctx->no_lease;
2751 }
2752
2753 /*
2754 * We can have only one retry value for a connection to a share so for
2755 * resources mounted more than once to the same server share the last
2756 * value passed in for the retry flag is used.
2757 */
2758 tcon->retry = ctx->retry;
2759 tcon->nocase = ctx->nocase;
2760 tcon->broken_sparse_sup = ctx->no_sparse;
2761 tcon->max_cached_dirs = ctx->max_cached_dirs;
2762 tcon->nodelete = ctx->nodelete;
2763 tcon->local_lease = ctx->local_lease;
2764 INIT_LIST_HEAD(&tcon->pending_opens);
2765 tcon->status = TID_GOOD;
2766
2767 INIT_DELAYED_WORK(&tcon->query_interfaces,
2768 smb2_query_server_interfaces);
2769 if (ses->server->dialect >= SMB30_PROT_ID &&
2770 (ses->server->capabilities & SMB2_GLOBAL_CAP_MULTI_CHANNEL)) {
2771 /* schedule query interfaces poll */
2772 queue_delayed_work(cifsiod_wq, &tcon->query_interfaces,
2773 (SMB_INTERFACE_POLL_INTERVAL * HZ));
2774 }
2775 #ifdef CONFIG_CIFS_DFS_UPCALL
2776 INIT_DELAYED_WORK(&tcon->dfs_cache_work, dfs_cache_refresh);
2777 #endif
2778 spin_lock(&cifs_tcp_ses_lock);
2779 list_add(&tcon->tcon_list, &ses->tcon_list);
2780 spin_unlock(&cifs_tcp_ses_lock);
2781
2782 return tcon;
2783
2784 out_fail:
2785 tconInfoFree(tcon, netfs_trace_tcon_ref_free_fail);
2786 return ERR_PTR(rc);
2787 }
2788
2789 void
cifs_put_tlink(struct tcon_link * tlink)2790 cifs_put_tlink(struct tcon_link *tlink)
2791 {
2792 if (!tlink || IS_ERR(tlink))
2793 return;
2794
2795 if (!atomic_dec_and_test(&tlink->tl_count) ||
2796 test_bit(TCON_LINK_IN_TREE, &tlink->tl_flags)) {
2797 tlink->tl_time = jiffies;
2798 return;
2799 }
2800
2801 if (!IS_ERR(tlink_tcon(tlink)))
2802 cifs_put_tcon(tlink_tcon(tlink), netfs_trace_tcon_ref_put_tlink);
2803 kfree(tlink);
2804 }
2805
2806 static int
compare_mount_options(struct super_block * sb,struct cifs_mnt_data * mnt_data)2807 compare_mount_options(struct super_block *sb, struct cifs_mnt_data *mnt_data)
2808 {
2809 struct cifs_sb_info *old = CIFS_SB(sb);
2810 struct cifs_sb_info *new = mnt_data->cifs_sb;
2811 unsigned int oldflags = old->mnt_cifs_flags & CIFS_MOUNT_MASK;
2812 unsigned int newflags = new->mnt_cifs_flags & CIFS_MOUNT_MASK;
2813
2814 if ((sb->s_flags & CIFS_MS_MASK) != (mnt_data->flags & CIFS_MS_MASK))
2815 return 0;
2816
2817 if (old->mnt_cifs_serverino_autodisabled)
2818 newflags &= ~CIFS_MOUNT_SERVER_INUM;
2819
2820 if (oldflags != newflags)
2821 return 0;
2822
2823 /*
2824 * We want to share sb only if we don't specify an r/wsize or
2825 * specified r/wsize is greater than or equal to existing one.
2826 */
2827 if (new->ctx->wsize && new->ctx->wsize < old->ctx->wsize)
2828 return 0;
2829
2830 if (new->ctx->rsize && new->ctx->rsize < old->ctx->rsize)
2831 return 0;
2832
2833 if (!uid_eq(old->ctx->linux_uid, new->ctx->linux_uid) ||
2834 !gid_eq(old->ctx->linux_gid, new->ctx->linux_gid))
2835 return 0;
2836
2837 if (old->ctx->file_mode != new->ctx->file_mode ||
2838 old->ctx->dir_mode != new->ctx->dir_mode)
2839 return 0;
2840
2841 if (strcmp(old->local_nls->charset, new->local_nls->charset))
2842 return 0;
2843
2844 if (old->ctx->acregmax != new->ctx->acregmax)
2845 return 0;
2846 if (old->ctx->acdirmax != new->ctx->acdirmax)
2847 return 0;
2848 if (old->ctx->closetimeo != new->ctx->closetimeo)
2849 return 0;
2850 if (old->ctx->reparse_type != new->ctx->reparse_type)
2851 return 0;
2852 if (old->ctx->nonativesocket != new->ctx->nonativesocket)
2853 return 0;
2854 if (old->ctx->symlink_type != new->ctx->symlink_type)
2855 return 0;
2856
2857 return 1;
2858 }
2859
match_prepath(struct super_block * sb,struct cifs_tcon * tcon,struct cifs_mnt_data * mnt_data)2860 static int match_prepath(struct super_block *sb,
2861 struct cifs_tcon *tcon,
2862 struct cifs_mnt_data *mnt_data)
2863 {
2864 struct smb3_fs_context *ctx = mnt_data->ctx;
2865 struct cifs_sb_info *old = CIFS_SB(sb);
2866 struct cifs_sb_info *new = mnt_data->cifs_sb;
2867 bool old_set = (old->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH) &&
2868 old->prepath;
2869 bool new_set = (new->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH) &&
2870 new->prepath;
2871
2872 if (tcon->origin_fullpath &&
2873 dfs_src_pathname_equal(tcon->origin_fullpath, ctx->source))
2874 return 1;
2875
2876 if (old_set && new_set && !strcmp(new->prepath, old->prepath))
2877 return 1;
2878 else if (!old_set && !new_set)
2879 return 1;
2880
2881 return 0;
2882 }
2883
2884 int
cifs_match_super(struct super_block * sb,void * data)2885 cifs_match_super(struct super_block *sb, void *data)
2886 {
2887 struct cifs_mnt_data *mnt_data = data;
2888 struct smb3_fs_context *ctx;
2889 struct cifs_sb_info *cifs_sb;
2890 struct TCP_Server_Info *tcp_srv;
2891 struct cifs_ses *ses;
2892 struct cifs_tcon *tcon;
2893 struct tcon_link *tlink;
2894 int rc = 0;
2895
2896 spin_lock(&cifs_tcp_ses_lock);
2897 cifs_sb = CIFS_SB(sb);
2898
2899 /* We do not want to use a superblock that has been shutdown */
2900 if (CIFS_MOUNT_SHUTDOWN & cifs_sb->mnt_cifs_flags) {
2901 spin_unlock(&cifs_tcp_ses_lock);
2902 return 0;
2903 }
2904
2905 tlink = cifs_get_tlink(cifs_sb_master_tlink(cifs_sb));
2906 if (IS_ERR_OR_NULL(tlink)) {
2907 pr_warn_once("%s: skip super matching due to bad tlink(%p)\n",
2908 __func__, tlink);
2909 spin_unlock(&cifs_tcp_ses_lock);
2910 return 0;
2911 }
2912 tcon = tlink_tcon(tlink);
2913 ses = tcon->ses;
2914 tcp_srv = ses->server;
2915
2916 ctx = mnt_data->ctx;
2917
2918 spin_lock(&tcp_srv->srv_lock);
2919 spin_lock(&ses->ses_lock);
2920 spin_lock(&ses->chan_lock);
2921 spin_lock(&tcon->tc_lock);
2922 if (!match_server(tcp_srv, ctx, true) ||
2923 !match_session(ses, ctx, true) ||
2924 !match_tcon(tcon, ctx) ||
2925 !match_prepath(sb, tcon, mnt_data)) {
2926 rc = 0;
2927 goto out;
2928 }
2929
2930 rc = compare_mount_options(sb, mnt_data);
2931 out:
2932 spin_unlock(&tcon->tc_lock);
2933 spin_unlock(&ses->chan_lock);
2934 spin_unlock(&ses->ses_lock);
2935 spin_unlock(&tcp_srv->srv_lock);
2936
2937 spin_unlock(&cifs_tcp_ses_lock);
2938 cifs_put_tlink(tlink);
2939 return rc;
2940 }
2941
2942 #ifdef CONFIG_DEBUG_LOCK_ALLOC
2943 static struct lock_class_key cifs_key[2];
2944 static struct lock_class_key cifs_slock_key[2];
2945
2946 static inline void
cifs_reclassify_socket4(struct socket * sock)2947 cifs_reclassify_socket4(struct socket *sock)
2948 {
2949 struct sock *sk = sock->sk;
2950
2951 BUG_ON(!sock_allow_reclassification(sk));
2952 sock_lock_init_class_and_name(sk, "slock-AF_INET-CIFS",
2953 &cifs_slock_key[0], "sk_lock-AF_INET-CIFS", &cifs_key[0]);
2954 }
2955
2956 static inline void
cifs_reclassify_socket6(struct socket * sock)2957 cifs_reclassify_socket6(struct socket *sock)
2958 {
2959 struct sock *sk = sock->sk;
2960
2961 BUG_ON(!sock_allow_reclassification(sk));
2962 sock_lock_init_class_and_name(sk, "slock-AF_INET6-CIFS",
2963 &cifs_slock_key[1], "sk_lock-AF_INET6-CIFS", &cifs_key[1]);
2964 }
2965 #else
2966 static inline void
cifs_reclassify_socket4(struct socket * sock)2967 cifs_reclassify_socket4(struct socket *sock)
2968 {
2969 }
2970
2971 static inline void
cifs_reclassify_socket6(struct socket * sock)2972 cifs_reclassify_socket6(struct socket *sock)
2973 {
2974 }
2975 #endif
2976
2977 /* See RFC1001 section 14 on representation of Netbios names */
rfc1002mangle(char * target,char * source,unsigned int length)2978 static void rfc1002mangle(char *target, char *source, unsigned int length)
2979 {
2980 unsigned int i, j;
2981
2982 for (i = 0, j = 0; i < (length); i++) {
2983 /* mask a nibble at a time and encode */
2984 target[j] = 'A' + (0x0F & (source[i] >> 4));
2985 target[j+1] = 'A' + (0x0F & source[i]);
2986 j += 2;
2987 }
2988
2989 }
2990
2991 static int
bind_socket(struct TCP_Server_Info * server)2992 bind_socket(struct TCP_Server_Info *server)
2993 {
2994 int rc = 0;
2995
2996 if (server->srcaddr.ss_family != AF_UNSPEC) {
2997 /* Bind to the specified local IP address */
2998 struct socket *socket = server->ssocket;
2999
3000 rc = kernel_bind(socket,
3001 (struct sockaddr *) &server->srcaddr,
3002 sizeof(server->srcaddr));
3003 if (rc < 0) {
3004 struct sockaddr_in *saddr4;
3005 struct sockaddr_in6 *saddr6;
3006
3007 saddr4 = (struct sockaddr_in *)&server->srcaddr;
3008 saddr6 = (struct sockaddr_in6 *)&server->srcaddr;
3009 if (saddr6->sin6_family == AF_INET6)
3010 cifs_server_dbg(VFS, "Failed to bind to: %pI6c, error: %d\n",
3011 &saddr6->sin6_addr, rc);
3012 else
3013 cifs_server_dbg(VFS, "Failed to bind to: %pI4, error: %d\n",
3014 &saddr4->sin_addr.s_addr, rc);
3015 }
3016 }
3017 return rc;
3018 }
3019
3020 static int
ip_rfc1001_connect(struct TCP_Server_Info * server)3021 ip_rfc1001_connect(struct TCP_Server_Info *server)
3022 {
3023 int rc = 0;
3024 /*
3025 * some servers require RFC1001 sessinit before sending
3026 * negprot - BB check reconnection in case where second
3027 * sessinit is sent but no second negprot
3028 */
3029 struct rfc1002_session_packet req = {};
3030 struct smb_hdr *smb_buf = (struct smb_hdr *)&req;
3031 unsigned int len;
3032
3033 req.trailer.session_req.called_len = sizeof(req.trailer.session_req.called_name);
3034
3035 if (server->server_RFC1001_name[0] != 0)
3036 rfc1002mangle(req.trailer.session_req.called_name,
3037 server->server_RFC1001_name,
3038 RFC1001_NAME_LEN_WITH_NULL);
3039 else
3040 rfc1002mangle(req.trailer.session_req.called_name,
3041 DEFAULT_CIFS_CALLED_NAME,
3042 RFC1001_NAME_LEN_WITH_NULL);
3043
3044 req.trailer.session_req.calling_len = sizeof(req.trailer.session_req.calling_name);
3045
3046 /* calling name ends in null (byte 16) from old smb convention */
3047 if (server->workstation_RFC1001_name[0] != 0)
3048 rfc1002mangle(req.trailer.session_req.calling_name,
3049 server->workstation_RFC1001_name,
3050 RFC1001_NAME_LEN_WITH_NULL);
3051 else
3052 rfc1002mangle(req.trailer.session_req.calling_name,
3053 "LINUX_CIFS_CLNT",
3054 RFC1001_NAME_LEN_WITH_NULL);
3055
3056 /*
3057 * As per rfc1002, @len must be the number of bytes that follows the
3058 * length field of a rfc1002 session request payload.
3059 */
3060 len = sizeof(req) - offsetof(struct rfc1002_session_packet, trailer.session_req);
3061
3062 smb_buf->smb_buf_length = cpu_to_be32((RFC1002_SESSION_REQUEST << 24) | len);
3063 rc = smb_send(server, smb_buf, len);
3064 /*
3065 * RFC1001 layer in at least one server requires very short break before
3066 * negprot presumably because not expecting negprot to follow so fast.
3067 * This is a simple solution that works without complicating the code
3068 * and causes no significant slowing down on mount for everyone else
3069 */
3070 usleep_range(1000, 2000);
3071
3072 return rc;
3073 }
3074
3075 static int
generic_ip_connect(struct TCP_Server_Info * server)3076 generic_ip_connect(struct TCP_Server_Info *server)
3077 {
3078 struct sockaddr *saddr;
3079 struct socket *socket;
3080 int slen, sfamily;
3081 __be16 sport;
3082 int rc = 0;
3083
3084 saddr = (struct sockaddr *) &server->dstaddr;
3085
3086 if (server->dstaddr.ss_family == AF_INET6) {
3087 struct sockaddr_in6 *ipv6 = (struct sockaddr_in6 *)&server->dstaddr;
3088
3089 sport = ipv6->sin6_port;
3090 slen = sizeof(struct sockaddr_in6);
3091 sfamily = AF_INET6;
3092 cifs_dbg(FYI, "%s: connecting to [%pI6]:%d\n", __func__, &ipv6->sin6_addr,
3093 ntohs(sport));
3094 } else {
3095 struct sockaddr_in *ipv4 = (struct sockaddr_in *)&server->dstaddr;
3096
3097 sport = ipv4->sin_port;
3098 slen = sizeof(struct sockaddr_in);
3099 sfamily = AF_INET;
3100 cifs_dbg(FYI, "%s: connecting to %pI4:%d\n", __func__, &ipv4->sin_addr,
3101 ntohs(sport));
3102 }
3103
3104 if (server->ssocket) {
3105 socket = server->ssocket;
3106 } else {
3107 struct net *net = cifs_net_ns(server);
3108
3109 rc = sock_create_kern(net, sfamily, SOCK_STREAM, IPPROTO_TCP, &server->ssocket);
3110 if (rc < 0) {
3111 cifs_server_dbg(VFS, "Error %d creating socket\n", rc);
3112 return rc;
3113 }
3114
3115 /*
3116 * Grab netns reference for the socket.
3117 *
3118 * It'll be released here, on error, or in clean_demultiplex_info() upon server
3119 * teardown.
3120 */
3121 get_net(net);
3122
3123 /* BB other socket options to set KEEPALIVE, NODELAY? */
3124 cifs_dbg(FYI, "Socket created\n");
3125 socket = server->ssocket;
3126 socket->sk->sk_allocation = GFP_NOFS;
3127 socket->sk->sk_use_task_frag = false;
3128 if (sfamily == AF_INET6)
3129 cifs_reclassify_socket6(socket);
3130 else
3131 cifs_reclassify_socket4(socket);
3132 }
3133
3134 rc = bind_socket(server);
3135 if (rc < 0) {
3136 put_net(cifs_net_ns(server));
3137 return rc;
3138 }
3139
3140 /*
3141 * Eventually check for other socket options to change from
3142 * the default. sock_setsockopt not used because it expects
3143 * user space buffer
3144 */
3145 socket->sk->sk_rcvtimeo = 7 * HZ;
3146 socket->sk->sk_sndtimeo = 5 * HZ;
3147
3148 /* make the bufsizes depend on wsize/rsize and max requests */
3149 if (server->noautotune) {
3150 if (socket->sk->sk_sndbuf < (200 * 1024))
3151 socket->sk->sk_sndbuf = 200 * 1024;
3152 if (socket->sk->sk_rcvbuf < (140 * 1024))
3153 socket->sk->sk_rcvbuf = 140 * 1024;
3154 }
3155
3156 if (server->tcp_nodelay)
3157 tcp_sock_set_nodelay(socket->sk);
3158
3159 cifs_dbg(FYI, "sndbuf %d rcvbuf %d rcvtimeo 0x%lx\n",
3160 socket->sk->sk_sndbuf,
3161 socket->sk->sk_rcvbuf, socket->sk->sk_rcvtimeo);
3162
3163 rc = kernel_connect(socket, saddr, slen,
3164 server->noblockcnt ? O_NONBLOCK : 0);
3165 /*
3166 * When mounting SMB root file systems, we do not want to block in
3167 * connect. Otherwise bail out and then let cifs_reconnect() perform
3168 * reconnect failover - if possible.
3169 */
3170 if (server->noblockcnt && rc == -EINPROGRESS)
3171 rc = 0;
3172 if (rc < 0) {
3173 cifs_dbg(FYI, "Error %d connecting to server\n", rc);
3174 trace_smb3_connect_err(server->hostname, server->conn_id, &server->dstaddr, rc);
3175 put_net(cifs_net_ns(server));
3176 sock_release(socket);
3177 server->ssocket = NULL;
3178 return rc;
3179 }
3180 trace_smb3_connect_done(server->hostname, server->conn_id, &server->dstaddr);
3181 if (sport == htons(RFC1001_PORT))
3182 rc = ip_rfc1001_connect(server);
3183
3184 if (rc < 0)
3185 put_net(cifs_net_ns(server));
3186
3187 return rc;
3188 }
3189
3190 static int
ip_connect(struct TCP_Server_Info * server)3191 ip_connect(struct TCP_Server_Info *server)
3192 {
3193 __be16 *sport;
3194 struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&server->dstaddr;
3195 struct sockaddr_in *addr = (struct sockaddr_in *)&server->dstaddr;
3196
3197 if (server->dstaddr.ss_family == AF_INET6)
3198 sport = &addr6->sin6_port;
3199 else
3200 sport = &addr->sin_port;
3201
3202 if (*sport == 0) {
3203 int rc;
3204
3205 /* try with 445 port at first */
3206 *sport = htons(CIFS_PORT);
3207
3208 rc = generic_ip_connect(server);
3209 if (rc >= 0)
3210 return rc;
3211
3212 /* if it failed, try with 139 port */
3213 *sport = htons(RFC1001_PORT);
3214 }
3215
3216 return generic_ip_connect(server);
3217 }
3218
3219 #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)3220 void reset_cifs_unix_caps(unsigned int xid, struct cifs_tcon *tcon,
3221 struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
3222 {
3223 /*
3224 * If we are reconnecting then should we check to see if
3225 * any requested capabilities changed locally e.g. via
3226 * remount but we can not do much about it here
3227 * if they have (even if we could detect it by the following)
3228 * Perhaps we could add a backpointer to array of sb from tcon
3229 * or if we change to make all sb to same share the same
3230 * sb as NFS - then we only have one backpointer to sb.
3231 * What if we wanted to mount the server share twice once with
3232 * and once without posixacls or posix paths?
3233 */
3234 __u64 saved_cap = le64_to_cpu(tcon->fsUnixInfo.Capability);
3235
3236 if (ctx && ctx->no_linux_ext) {
3237 tcon->fsUnixInfo.Capability = 0;
3238 tcon->unix_ext = 0; /* Unix Extensions disabled */
3239 cifs_dbg(FYI, "Linux protocol extensions disabled\n");
3240 return;
3241 } else if (ctx)
3242 tcon->unix_ext = 1; /* Unix Extensions supported */
3243
3244 if (!tcon->unix_ext) {
3245 cifs_dbg(FYI, "Unix extensions disabled so not set on reconnect\n");
3246 return;
3247 }
3248
3249 if (!CIFSSMBQFSUnixInfo(xid, tcon)) {
3250 __u64 cap = le64_to_cpu(tcon->fsUnixInfo.Capability);
3251
3252 cifs_dbg(FYI, "unix caps which server supports %lld\n", cap);
3253 /*
3254 * check for reconnect case in which we do not
3255 * want to change the mount behavior if we can avoid it
3256 */
3257 if (ctx == NULL) {
3258 /*
3259 * turn off POSIX ACL and PATHNAMES if not set
3260 * originally at mount time
3261 */
3262 if ((saved_cap & CIFS_UNIX_POSIX_ACL_CAP) == 0)
3263 cap &= ~CIFS_UNIX_POSIX_ACL_CAP;
3264 if ((saved_cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) == 0) {
3265 if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP)
3266 cifs_dbg(VFS, "POSIXPATH support change\n");
3267 cap &= ~CIFS_UNIX_POSIX_PATHNAMES_CAP;
3268 } else if ((cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) == 0) {
3269 cifs_dbg(VFS, "possible reconnect error\n");
3270 cifs_dbg(VFS, "server disabled POSIX path support\n");
3271 }
3272 }
3273
3274 if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)
3275 cifs_dbg(VFS, "per-share encryption not supported yet\n");
3276
3277 cap &= CIFS_UNIX_CAP_MASK;
3278 if (ctx && ctx->no_psx_acl)
3279 cap &= ~CIFS_UNIX_POSIX_ACL_CAP;
3280 else if (CIFS_UNIX_POSIX_ACL_CAP & cap) {
3281 cifs_dbg(FYI, "negotiated posix acl support\n");
3282 if (cifs_sb)
3283 cifs_sb->mnt_cifs_flags |=
3284 CIFS_MOUNT_POSIXACL;
3285 }
3286
3287 if (ctx && ctx->posix_paths == 0)
3288 cap &= ~CIFS_UNIX_POSIX_PATHNAMES_CAP;
3289 else if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) {
3290 cifs_dbg(FYI, "negotiate posix pathnames\n");
3291 if (cifs_sb)
3292 cifs_sb->mnt_cifs_flags |=
3293 CIFS_MOUNT_POSIX_PATHS;
3294 }
3295
3296 cifs_dbg(FYI, "Negotiate caps 0x%x\n", (int)cap);
3297 #ifdef CONFIG_CIFS_DEBUG2
3298 if (cap & CIFS_UNIX_FCNTL_CAP)
3299 cifs_dbg(FYI, "FCNTL cap\n");
3300 if (cap & CIFS_UNIX_EXTATTR_CAP)
3301 cifs_dbg(FYI, "EXTATTR cap\n");
3302 if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP)
3303 cifs_dbg(FYI, "POSIX path cap\n");
3304 if (cap & CIFS_UNIX_XATTR_CAP)
3305 cifs_dbg(FYI, "XATTR cap\n");
3306 if (cap & CIFS_UNIX_POSIX_ACL_CAP)
3307 cifs_dbg(FYI, "POSIX ACL cap\n");
3308 if (cap & CIFS_UNIX_LARGE_READ_CAP)
3309 cifs_dbg(FYI, "very large read cap\n");
3310 if (cap & CIFS_UNIX_LARGE_WRITE_CAP)
3311 cifs_dbg(FYI, "very large write cap\n");
3312 if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_CAP)
3313 cifs_dbg(FYI, "transport encryption cap\n");
3314 if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)
3315 cifs_dbg(FYI, "mandatory transport encryption cap\n");
3316 #endif /* CIFS_DEBUG2 */
3317 if (CIFSSMBSetFSUnixInfo(xid, tcon, cap)) {
3318 if (ctx == NULL)
3319 cifs_dbg(FYI, "resetting capabilities failed\n");
3320 else
3321 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");
3322
3323 }
3324 }
3325 }
3326 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
3327
cifs_setup_cifs_sb(struct cifs_sb_info * cifs_sb)3328 int cifs_setup_cifs_sb(struct cifs_sb_info *cifs_sb)
3329 {
3330 struct smb3_fs_context *ctx = cifs_sb->ctx;
3331
3332 INIT_DELAYED_WORK(&cifs_sb->prune_tlinks, cifs_prune_tlinks);
3333
3334 spin_lock_init(&cifs_sb->tlink_tree_lock);
3335 cifs_sb->tlink_tree = RB_ROOT;
3336
3337 cifs_dbg(FYI, "file mode: %04ho dir mode: %04ho\n",
3338 ctx->file_mode, ctx->dir_mode);
3339
3340 /* this is needed for ASCII cp to Unicode converts */
3341 if (ctx->iocharset == NULL) {
3342 /* load_nls_default cannot return null */
3343 cifs_sb->local_nls = load_nls_default();
3344 } else {
3345 cifs_sb->local_nls = load_nls(ctx->iocharset);
3346 if (cifs_sb->local_nls == NULL) {
3347 cifs_dbg(VFS, "CIFS mount error: iocharset %s not found\n",
3348 ctx->iocharset);
3349 return -ELIBACC;
3350 }
3351 }
3352 ctx->local_nls = cifs_sb->local_nls;
3353
3354 smb3_update_mnt_flags(cifs_sb);
3355
3356 if (ctx->direct_io)
3357 cifs_dbg(FYI, "mounting share using direct i/o\n");
3358 if (ctx->cache_ro) {
3359 cifs_dbg(VFS, "mounting share with read only caching. Ensure that the share will not be modified while in use.\n");
3360 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_RO_CACHE;
3361 } else if (ctx->cache_rw) {
3362 cifs_dbg(VFS, "mounting share in single client RW caching mode. Ensure that no other systems will be accessing the share.\n");
3363 cifs_sb->mnt_cifs_flags |= (CIFS_MOUNT_RO_CACHE |
3364 CIFS_MOUNT_RW_CACHE);
3365 }
3366
3367 if ((ctx->cifs_acl) && (ctx->dynperm))
3368 cifs_dbg(VFS, "mount option dynperm ignored if cifsacl mount option supported\n");
3369
3370 if (ctx->prepath) {
3371 cifs_sb->prepath = kstrdup(ctx->prepath, GFP_KERNEL);
3372 if (cifs_sb->prepath == NULL)
3373 return -ENOMEM;
3374 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
3375 }
3376
3377 return 0;
3378 }
3379
3380 /* Release all succeed connections */
cifs_mount_put_conns(struct cifs_mount_ctx * mnt_ctx)3381 void cifs_mount_put_conns(struct cifs_mount_ctx *mnt_ctx)
3382 {
3383 int rc = 0;
3384
3385 if (mnt_ctx->tcon)
3386 cifs_put_tcon(mnt_ctx->tcon, netfs_trace_tcon_ref_put_mnt_ctx);
3387 else if (mnt_ctx->ses)
3388 cifs_put_smb_ses(mnt_ctx->ses);
3389 else if (mnt_ctx->server)
3390 cifs_put_tcp_session(mnt_ctx->server, 0);
3391 mnt_ctx->ses = NULL;
3392 mnt_ctx->tcon = NULL;
3393 mnt_ctx->server = NULL;
3394 mnt_ctx->cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_POSIX_PATHS;
3395 free_xid(mnt_ctx->xid);
3396 }
3397
cifs_mount_get_session(struct cifs_mount_ctx * mnt_ctx)3398 int cifs_mount_get_session(struct cifs_mount_ctx *mnt_ctx)
3399 {
3400 struct TCP_Server_Info *server = NULL;
3401 struct smb3_fs_context *ctx;
3402 struct cifs_ses *ses = NULL;
3403 unsigned int xid;
3404 int rc = 0;
3405
3406 xid = get_xid();
3407
3408 if (WARN_ON_ONCE(!mnt_ctx || !mnt_ctx->fs_ctx)) {
3409 rc = -EINVAL;
3410 goto out;
3411 }
3412 ctx = mnt_ctx->fs_ctx;
3413
3414 /* get a reference to a tcp session */
3415 server = cifs_get_tcp_session(ctx, NULL);
3416 if (IS_ERR(server)) {
3417 rc = PTR_ERR(server);
3418 server = NULL;
3419 goto out;
3420 }
3421
3422 /* get a reference to a SMB session */
3423 ses = cifs_get_smb_ses(server, ctx);
3424 if (IS_ERR(ses)) {
3425 rc = PTR_ERR(ses);
3426 ses = NULL;
3427 goto out;
3428 }
3429
3430 if ((ctx->persistent == true) && (!(ses->server->capabilities &
3431 SMB2_GLOBAL_CAP_PERSISTENT_HANDLES))) {
3432 cifs_server_dbg(VFS, "persistent handles not supported by server\n");
3433 rc = -EOPNOTSUPP;
3434 }
3435
3436 out:
3437 mnt_ctx->xid = xid;
3438 mnt_ctx->server = server;
3439 mnt_ctx->ses = ses;
3440 mnt_ctx->tcon = NULL;
3441
3442 return rc;
3443 }
3444
cifs_mount_get_tcon(struct cifs_mount_ctx * mnt_ctx)3445 int cifs_mount_get_tcon(struct cifs_mount_ctx *mnt_ctx)
3446 {
3447 struct TCP_Server_Info *server;
3448 struct cifs_sb_info *cifs_sb;
3449 struct smb3_fs_context *ctx;
3450 struct cifs_tcon *tcon = NULL;
3451 int rc = 0;
3452
3453 if (WARN_ON_ONCE(!mnt_ctx || !mnt_ctx->server || !mnt_ctx->ses || !mnt_ctx->fs_ctx ||
3454 !mnt_ctx->cifs_sb)) {
3455 rc = -EINVAL;
3456 goto out;
3457 }
3458 server = mnt_ctx->server;
3459 ctx = mnt_ctx->fs_ctx;
3460 cifs_sb = mnt_ctx->cifs_sb;
3461
3462 /* search for existing tcon to this server share */
3463 tcon = cifs_get_tcon(mnt_ctx->ses, ctx);
3464 if (IS_ERR(tcon)) {
3465 rc = PTR_ERR(tcon);
3466 tcon = NULL;
3467 goto out;
3468 }
3469
3470 /* if new SMB3.11 POSIX extensions are supported do not remap / and \ */
3471 if (tcon->posix_extensions)
3472 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_POSIX_PATHS;
3473
3474 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
3475 /* tell server which Unix caps we support */
3476 if (cap_unix(tcon->ses)) {
3477 /*
3478 * reset of caps checks mount to see if unix extensions disabled
3479 * for just this mount.
3480 */
3481 reset_cifs_unix_caps(mnt_ctx->xid, tcon, cifs_sb, ctx);
3482 spin_lock(&tcon->ses->server->srv_lock);
3483 if ((tcon->ses->server->tcpStatus == CifsNeedReconnect) &&
3484 (le64_to_cpu(tcon->fsUnixInfo.Capability) &
3485 CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)) {
3486 spin_unlock(&tcon->ses->server->srv_lock);
3487 rc = -EACCES;
3488 goto out;
3489 }
3490 spin_unlock(&tcon->ses->server->srv_lock);
3491 } else
3492 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
3493 tcon->unix_ext = 0; /* server does not support them */
3494
3495 /* do not care if a following call succeed - informational */
3496 if (!tcon->pipe && server->ops->qfs_tcon) {
3497 server->ops->qfs_tcon(mnt_ctx->xid, tcon, cifs_sb);
3498 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RO_CACHE) {
3499 if (tcon->fsDevInfo.DeviceCharacteristics &
3500 cpu_to_le32(FILE_READ_ONLY_DEVICE))
3501 cifs_dbg(VFS, "mounted to read only share\n");
3502 else if ((cifs_sb->mnt_cifs_flags &
3503 CIFS_MOUNT_RW_CACHE) == 0)
3504 cifs_dbg(VFS, "read only mount of RW share\n");
3505 /* no need to log a RW mount of a typical RW share */
3506 }
3507 }
3508
3509 /*
3510 * Clamp the rsize/wsize mount arguments if they are too big for the server
3511 * and set the rsize/wsize to the negotiated values if not passed in by
3512 * the user on mount
3513 */
3514 if ((cifs_sb->ctx->wsize == 0) ||
3515 (cifs_sb->ctx->wsize > server->ops->negotiate_wsize(tcon, ctx))) {
3516 cifs_sb->ctx->wsize =
3517 round_down(server->ops->negotiate_wsize(tcon, ctx), PAGE_SIZE);
3518 /*
3519 * in the very unlikely event that the server sent a max write size under PAGE_SIZE,
3520 * (which would get rounded down to 0) then reset wsize to absolute minimum eg 4096
3521 */
3522 if (cifs_sb->ctx->wsize == 0) {
3523 cifs_sb->ctx->wsize = PAGE_SIZE;
3524 cifs_dbg(VFS, "wsize too small, reset to minimum ie PAGE_SIZE, usually 4096\n");
3525 }
3526 }
3527 if ((cifs_sb->ctx->rsize == 0) ||
3528 (cifs_sb->ctx->rsize > server->ops->negotiate_rsize(tcon, ctx)))
3529 cifs_sb->ctx->rsize = server->ops->negotiate_rsize(tcon, ctx);
3530
3531 /*
3532 * The cookie is initialized from volume info returned above.
3533 * Inside cifs_fscache_get_super_cookie it checks
3534 * that we do not get super cookie twice.
3535 */
3536 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_FSCACHE)
3537 cifs_fscache_get_super_cookie(tcon);
3538
3539 out:
3540 mnt_ctx->tcon = tcon;
3541 return rc;
3542 }
3543
mount_setup_tlink(struct cifs_sb_info * cifs_sb,struct cifs_ses * ses,struct cifs_tcon * tcon)3544 static int mount_setup_tlink(struct cifs_sb_info *cifs_sb, struct cifs_ses *ses,
3545 struct cifs_tcon *tcon)
3546 {
3547 struct tcon_link *tlink;
3548
3549 /* hang the tcon off of the superblock */
3550 tlink = kzalloc(sizeof(*tlink), GFP_KERNEL);
3551 if (tlink == NULL)
3552 return -ENOMEM;
3553
3554 tlink->tl_uid = ses->linux_uid;
3555 tlink->tl_tcon = tcon;
3556 tlink->tl_time = jiffies;
3557 set_bit(TCON_LINK_MASTER, &tlink->tl_flags);
3558 set_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
3559
3560 cifs_sb->master_tlink = tlink;
3561 spin_lock(&cifs_sb->tlink_tree_lock);
3562 tlink_rb_insert(&cifs_sb->tlink_tree, tlink);
3563 spin_unlock(&cifs_sb->tlink_tree_lock);
3564
3565 queue_delayed_work(cifsiod_wq, &cifs_sb->prune_tlinks,
3566 TLINK_IDLE_EXPIRE);
3567 return 0;
3568 }
3569
3570 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)3571 cifs_are_all_path_components_accessible(struct TCP_Server_Info *server,
3572 unsigned int xid,
3573 struct cifs_tcon *tcon,
3574 struct cifs_sb_info *cifs_sb,
3575 char *full_path,
3576 int added_treename)
3577 {
3578 int rc;
3579 char *s;
3580 char sep, tmp;
3581 int skip = added_treename ? 1 : 0;
3582
3583 sep = CIFS_DIR_SEP(cifs_sb);
3584 s = full_path;
3585
3586 rc = server->ops->is_path_accessible(xid, tcon, cifs_sb, "");
3587 while (rc == 0) {
3588 /* skip separators */
3589 while (*s == sep)
3590 s++;
3591 if (!*s)
3592 break;
3593 /* next separator */
3594 while (*s && *s != sep)
3595 s++;
3596 /*
3597 * if the treename is added, we then have to skip the first
3598 * part within the separators
3599 */
3600 if (skip) {
3601 skip = 0;
3602 continue;
3603 }
3604 /*
3605 * temporarily null-terminate the path at the end of
3606 * the current component
3607 */
3608 tmp = *s;
3609 *s = 0;
3610 rc = server->ops->is_path_accessible(xid, tcon, cifs_sb,
3611 full_path);
3612 *s = tmp;
3613 }
3614 return rc;
3615 }
3616
3617 /*
3618 * Check if path is remote (i.e. a DFS share).
3619 *
3620 * Return -EREMOTE if it is, otherwise 0 or -errno.
3621 */
cifs_is_path_remote(struct cifs_mount_ctx * mnt_ctx)3622 int cifs_is_path_remote(struct cifs_mount_ctx *mnt_ctx)
3623 {
3624 int rc;
3625 struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3626 struct TCP_Server_Info *server = mnt_ctx->server;
3627 unsigned int xid = mnt_ctx->xid;
3628 struct cifs_tcon *tcon = mnt_ctx->tcon;
3629 struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
3630 char *full_path;
3631
3632 if (!server->ops->is_path_accessible)
3633 return -EOPNOTSUPP;
3634
3635 /*
3636 * cifs_build_path_to_root works only when we have a valid tcon
3637 */
3638 full_path = cifs_build_path_to_root(ctx, cifs_sb, tcon,
3639 tcon->Flags & SMB_SHARE_IS_IN_DFS);
3640 if (full_path == NULL)
3641 return -ENOMEM;
3642
3643 cifs_dbg(FYI, "%s: full_path: %s\n", __func__, full_path);
3644
3645 rc = server->ops->is_path_accessible(xid, tcon, cifs_sb,
3646 full_path);
3647 if (rc != 0 && rc != -EREMOTE)
3648 goto out;
3649
3650 if (rc != -EREMOTE) {
3651 rc = cifs_are_all_path_components_accessible(server, xid, tcon,
3652 cifs_sb, full_path, tcon->Flags & SMB_SHARE_IS_IN_DFS);
3653 if (rc != 0) {
3654 cifs_server_dbg(VFS, "cannot query dirs between root and final path, enabling CIFS_MOUNT_USE_PREFIX_PATH\n");
3655 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
3656 rc = 0;
3657 }
3658 }
3659
3660 out:
3661 kfree(full_path);
3662 return rc;
3663 }
3664
3665 #ifdef CONFIG_CIFS_DFS_UPCALL
cifs_mount(struct cifs_sb_info * cifs_sb,struct smb3_fs_context * ctx)3666 int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
3667 {
3668 struct cifs_mount_ctx mnt_ctx = { .cifs_sb = cifs_sb, .fs_ctx = ctx, };
3669 int rc;
3670
3671 rc = dfs_mount_share(&mnt_ctx);
3672 if (rc)
3673 goto error;
3674 if (!ctx->dfs_conn)
3675 goto out;
3676
3677 /*
3678 * After reconnecting to a different server, unique ids won't match anymore, so we disable
3679 * serverino. This prevents dentry revalidation to think the dentry are stale (ESTALE).
3680 */
3681 cifs_autodisable_serverino(cifs_sb);
3682 /*
3683 * Force the use of prefix path to support failover on DFS paths that resolve to targets
3684 * that have different prefix paths.
3685 */
3686 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
3687 kfree(cifs_sb->prepath);
3688 cifs_sb->prepath = ctx->prepath;
3689 ctx->prepath = NULL;
3690
3691 out:
3692 cifs_try_adding_channels(mnt_ctx.ses);
3693 rc = mount_setup_tlink(cifs_sb, mnt_ctx.ses, mnt_ctx.tcon);
3694 if (rc)
3695 goto error;
3696
3697 free_xid(mnt_ctx.xid);
3698 return rc;
3699
3700 error:
3701 cifs_mount_put_conns(&mnt_ctx);
3702 return rc;
3703 }
3704 #else
cifs_mount(struct cifs_sb_info * cifs_sb,struct smb3_fs_context * ctx)3705 int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
3706 {
3707 int rc = 0;
3708 struct cifs_mount_ctx mnt_ctx = { .cifs_sb = cifs_sb, .fs_ctx = ctx, };
3709
3710 rc = cifs_mount_get_session(&mnt_ctx);
3711 if (rc)
3712 goto error;
3713
3714 rc = cifs_mount_get_tcon(&mnt_ctx);
3715 if (!rc) {
3716 /*
3717 * Prevent superblock from being created with any missing
3718 * connections.
3719 */
3720 if (WARN_ON(!mnt_ctx.server))
3721 rc = -EHOSTDOWN;
3722 else if (WARN_ON(!mnt_ctx.ses))
3723 rc = -EACCES;
3724 else if (WARN_ON(!mnt_ctx.tcon))
3725 rc = -ENOENT;
3726 }
3727 if (rc)
3728 goto error;
3729
3730 rc = cifs_is_path_remote(&mnt_ctx);
3731 if (rc == -EREMOTE)
3732 rc = -EOPNOTSUPP;
3733 if (rc)
3734 goto error;
3735
3736 rc = mount_setup_tlink(cifs_sb, mnt_ctx.ses, mnt_ctx.tcon);
3737 if (rc)
3738 goto error;
3739
3740 free_xid(mnt_ctx.xid);
3741 return rc;
3742
3743 error:
3744 cifs_mount_put_conns(&mnt_ctx);
3745 return rc;
3746 }
3747 #endif
3748
3749 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
3750 /*
3751 * Issue a TREE_CONNECT request.
3752 */
3753 int
CIFSTCon(const unsigned int xid,struct cifs_ses * ses,const char * tree,struct cifs_tcon * tcon,const struct nls_table * nls_codepage)3754 CIFSTCon(const unsigned int xid, struct cifs_ses *ses,
3755 const char *tree, struct cifs_tcon *tcon,
3756 const struct nls_table *nls_codepage)
3757 {
3758 struct smb_hdr *smb_buffer;
3759 struct smb_hdr *smb_buffer_response;
3760 TCONX_REQ *pSMB;
3761 TCONX_RSP *pSMBr;
3762 unsigned char *bcc_ptr;
3763 int rc = 0;
3764 int length;
3765 __u16 bytes_left, count;
3766
3767 if (ses == NULL)
3768 return -EIO;
3769
3770 smb_buffer = cifs_buf_get();
3771 if (smb_buffer == NULL)
3772 return -ENOMEM;
3773
3774 smb_buffer_response = smb_buffer;
3775
3776 header_assemble(smb_buffer, SMB_COM_TREE_CONNECT_ANDX,
3777 NULL /*no tid */, 4 /*wct */);
3778
3779 smb_buffer->Mid = get_next_mid(ses->server);
3780 smb_buffer->Uid = ses->Suid;
3781 pSMB = (TCONX_REQ *) smb_buffer;
3782 pSMBr = (TCONX_RSP *) smb_buffer_response;
3783
3784 pSMB->AndXCommand = 0xFF;
3785 pSMB->Flags = cpu_to_le16(TCON_EXTENDED_SECINFO);
3786 bcc_ptr = &pSMB->Password[0];
3787
3788 pSMB->PasswordLength = cpu_to_le16(1); /* minimum */
3789 *bcc_ptr = 0; /* password is null byte */
3790 bcc_ptr++; /* skip password */
3791 /* already aligned so no need to do it below */
3792
3793 if (ses->server->sign)
3794 smb_buffer->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
3795
3796 if (ses->capabilities & CAP_STATUS32)
3797 smb_buffer->Flags2 |= SMBFLG2_ERR_STATUS;
3798
3799 if (ses->capabilities & CAP_DFS)
3800 smb_buffer->Flags2 |= SMBFLG2_DFS;
3801
3802 if (ses->capabilities & CAP_UNICODE) {
3803 smb_buffer->Flags2 |= SMBFLG2_UNICODE;
3804 length =
3805 cifs_strtoUTF16((__le16 *) bcc_ptr, tree,
3806 6 /* max utf8 char length in bytes */ *
3807 (/* server len*/ + 256 /* share len */), nls_codepage);
3808 bcc_ptr += 2 * length; /* convert num 16 bit words to bytes */
3809 bcc_ptr += 2; /* skip trailing null */
3810 } else { /* ASCII */
3811 strcpy(bcc_ptr, tree);
3812 bcc_ptr += strlen(tree) + 1;
3813 }
3814 strcpy(bcc_ptr, "?????");
3815 bcc_ptr += strlen("?????");
3816 bcc_ptr += 1;
3817 count = bcc_ptr - &pSMB->Password[0];
3818 be32_add_cpu(&pSMB->hdr.smb_buf_length, count);
3819 pSMB->ByteCount = cpu_to_le16(count);
3820
3821 rc = SendReceive(xid, ses, smb_buffer, smb_buffer_response, &length,
3822 0);
3823
3824 /* above now done in SendReceive */
3825 if (rc == 0) {
3826 bool is_unicode;
3827
3828 tcon->tid = smb_buffer_response->Tid;
3829 bcc_ptr = pByteArea(smb_buffer_response);
3830 bytes_left = get_bcc(smb_buffer_response);
3831 length = strnlen(bcc_ptr, bytes_left - 2);
3832 if (smb_buffer->Flags2 & SMBFLG2_UNICODE)
3833 is_unicode = true;
3834 else
3835 is_unicode = false;
3836
3837
3838 /* skip service field (NB: this field is always ASCII) */
3839 if (length == 3) {
3840 if ((bcc_ptr[0] == 'I') && (bcc_ptr[1] == 'P') &&
3841 (bcc_ptr[2] == 'C')) {
3842 cifs_dbg(FYI, "IPC connection\n");
3843 tcon->ipc = true;
3844 tcon->pipe = true;
3845 }
3846 } else if (length == 2) {
3847 if ((bcc_ptr[0] == 'A') && (bcc_ptr[1] == ':')) {
3848 /* the most common case */
3849 cifs_dbg(FYI, "disk share connection\n");
3850 }
3851 }
3852 bcc_ptr += length + 1;
3853 bytes_left -= (length + 1);
3854 strscpy(tcon->tree_name, tree, sizeof(tcon->tree_name));
3855
3856 /* mostly informational -- no need to fail on error here */
3857 kfree(tcon->nativeFileSystem);
3858 tcon->nativeFileSystem = cifs_strndup_from_utf16(bcc_ptr,
3859 bytes_left, is_unicode,
3860 nls_codepage);
3861
3862 cifs_dbg(FYI, "nativeFileSystem=%s\n", tcon->nativeFileSystem);
3863
3864 if ((smb_buffer_response->WordCount == 3) ||
3865 (smb_buffer_response->WordCount == 7))
3866 /* field is in same location */
3867 tcon->Flags = le16_to_cpu(pSMBr->OptionalSupport);
3868 else
3869 tcon->Flags = 0;
3870 cifs_dbg(FYI, "Tcon flags: 0x%x\n", tcon->Flags);
3871
3872 /*
3873 * reset_cifs_unix_caps calls QFSInfo which requires
3874 * need_reconnect to be false, but we would not need to call
3875 * reset_caps if this were not a reconnect case so must check
3876 * need_reconnect flag here. The caller will also clear
3877 * need_reconnect when tcon was successful but needed to be
3878 * cleared earlier in the case of unix extensions reconnect
3879 */
3880 if (tcon->need_reconnect && tcon->unix_ext) {
3881 cifs_dbg(FYI, "resetting caps for %s\n", tcon->tree_name);
3882 tcon->need_reconnect = false;
3883 reset_cifs_unix_caps(xid, tcon, NULL, NULL);
3884 }
3885 }
3886 cifs_buf_release(smb_buffer);
3887 return rc;
3888 }
3889 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
3890
delayed_free(struct rcu_head * p)3891 static void delayed_free(struct rcu_head *p)
3892 {
3893 struct cifs_sb_info *cifs_sb = container_of(p, struct cifs_sb_info, rcu);
3894
3895 unload_nls(cifs_sb->local_nls);
3896 smb3_cleanup_fs_context(cifs_sb->ctx);
3897 kfree(cifs_sb);
3898 }
3899
3900 void
cifs_umount(struct cifs_sb_info * cifs_sb)3901 cifs_umount(struct cifs_sb_info *cifs_sb)
3902 {
3903 struct rb_root *root = &cifs_sb->tlink_tree;
3904 struct rb_node *node;
3905 struct tcon_link *tlink;
3906
3907 cancel_delayed_work_sync(&cifs_sb->prune_tlinks);
3908
3909 spin_lock(&cifs_sb->tlink_tree_lock);
3910 while ((node = rb_first(root))) {
3911 tlink = rb_entry(node, struct tcon_link, tl_rbnode);
3912 cifs_get_tlink(tlink);
3913 clear_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
3914 rb_erase(node, root);
3915
3916 spin_unlock(&cifs_sb->tlink_tree_lock);
3917 cifs_put_tlink(tlink);
3918 spin_lock(&cifs_sb->tlink_tree_lock);
3919 }
3920 spin_unlock(&cifs_sb->tlink_tree_lock);
3921
3922 kfree(cifs_sb->prepath);
3923 call_rcu(&cifs_sb->rcu, delayed_free);
3924 }
3925
3926 int
cifs_negotiate_protocol(const unsigned int xid,struct cifs_ses * ses,struct TCP_Server_Info * server)3927 cifs_negotiate_protocol(const unsigned int xid, struct cifs_ses *ses,
3928 struct TCP_Server_Info *server)
3929 {
3930 int rc = 0;
3931
3932 if (!server->ops->need_neg || !server->ops->negotiate)
3933 return -ENOSYS;
3934
3935 /* only send once per connect */
3936 spin_lock(&server->srv_lock);
3937 if (server->tcpStatus != CifsGood &&
3938 server->tcpStatus != CifsNew &&
3939 server->tcpStatus != CifsNeedNegotiate) {
3940 spin_unlock(&server->srv_lock);
3941 return -EHOSTDOWN;
3942 }
3943
3944 if (!server->ops->need_neg(server) &&
3945 server->tcpStatus == CifsGood) {
3946 spin_unlock(&server->srv_lock);
3947 return 0;
3948 }
3949
3950 server->tcpStatus = CifsInNegotiate;
3951 spin_unlock(&server->srv_lock);
3952
3953 rc = server->ops->negotiate(xid, ses, server);
3954 if (rc == 0) {
3955 spin_lock(&server->srv_lock);
3956 if (server->tcpStatus == CifsInNegotiate)
3957 server->tcpStatus = CifsGood;
3958 else
3959 rc = -EHOSTDOWN;
3960 spin_unlock(&server->srv_lock);
3961 } else {
3962 spin_lock(&server->srv_lock);
3963 if (server->tcpStatus == CifsInNegotiate)
3964 server->tcpStatus = CifsNeedNegotiate;
3965 spin_unlock(&server->srv_lock);
3966 }
3967
3968 return rc;
3969 }
3970
3971 int
cifs_setup_session(const unsigned int xid,struct cifs_ses * ses,struct TCP_Server_Info * server,struct nls_table * nls_info)3972 cifs_setup_session(const unsigned int xid, struct cifs_ses *ses,
3973 struct TCP_Server_Info *server,
3974 struct nls_table *nls_info)
3975 {
3976 int rc = -ENOSYS;
3977 struct TCP_Server_Info *pserver = SERVER_IS_CHAN(server) ? server->primary_server : server;
3978 struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&pserver->dstaddr;
3979 struct sockaddr_in *addr = (struct sockaddr_in *)&pserver->dstaddr;
3980 bool is_binding = false;
3981
3982 spin_lock(&ses->ses_lock);
3983 cifs_dbg(FYI, "%s: channel connect bitmap: 0x%lx\n",
3984 __func__, ses->chans_need_reconnect);
3985
3986 if (ses->ses_status != SES_GOOD &&
3987 ses->ses_status != SES_NEW &&
3988 ses->ses_status != SES_NEED_RECON) {
3989 spin_unlock(&ses->ses_lock);
3990 return -EHOSTDOWN;
3991 }
3992
3993 /* only send once per connect */
3994 spin_lock(&ses->chan_lock);
3995 if (CIFS_ALL_CHANS_GOOD(ses)) {
3996 if (ses->ses_status == SES_NEED_RECON)
3997 ses->ses_status = SES_GOOD;
3998 spin_unlock(&ses->chan_lock);
3999 spin_unlock(&ses->ses_lock);
4000 return 0;
4001 }
4002
4003 cifs_chan_set_in_reconnect(ses, server);
4004 is_binding = !CIFS_ALL_CHANS_NEED_RECONNECT(ses);
4005 spin_unlock(&ses->chan_lock);
4006
4007 if (!is_binding) {
4008 ses->ses_status = SES_IN_SETUP;
4009
4010 /* force iface_list refresh */
4011 ses->iface_last_update = 0;
4012 }
4013 spin_unlock(&ses->ses_lock);
4014
4015 /* update ses ip_addr only for primary chan */
4016 if (server == pserver) {
4017 if (server->dstaddr.ss_family == AF_INET6)
4018 scnprintf(ses->ip_addr, sizeof(ses->ip_addr), "%pI6", &addr6->sin6_addr);
4019 else
4020 scnprintf(ses->ip_addr, sizeof(ses->ip_addr), "%pI4", &addr->sin_addr);
4021 }
4022
4023 if (!is_binding) {
4024 ses->capabilities = server->capabilities;
4025 if (!linuxExtEnabled)
4026 ses->capabilities &= (~server->vals->cap_unix);
4027
4028 if (ses->auth_key.response) {
4029 cifs_dbg(FYI, "Free previous auth_key.response = %p\n",
4030 ses->auth_key.response);
4031 kfree_sensitive(ses->auth_key.response);
4032 ses->auth_key.response = NULL;
4033 ses->auth_key.len = 0;
4034 }
4035 }
4036
4037 cifs_dbg(FYI, "Security Mode: 0x%x Capabilities: 0x%x TimeAdjust: %d\n",
4038 server->sec_mode, server->capabilities, server->timeAdj);
4039
4040 if (server->ops->sess_setup)
4041 rc = server->ops->sess_setup(xid, ses, server, nls_info);
4042
4043 if (rc) {
4044 cifs_server_dbg(VFS, "Send error in SessSetup = %d\n", rc);
4045 spin_lock(&ses->ses_lock);
4046 if (ses->ses_status == SES_IN_SETUP)
4047 ses->ses_status = SES_NEED_RECON;
4048 spin_lock(&ses->chan_lock);
4049 cifs_chan_clear_in_reconnect(ses, server);
4050 spin_unlock(&ses->chan_lock);
4051 spin_unlock(&ses->ses_lock);
4052 } else {
4053 spin_lock(&ses->ses_lock);
4054 if (ses->ses_status == SES_IN_SETUP)
4055 ses->ses_status = SES_GOOD;
4056 spin_lock(&ses->chan_lock);
4057 cifs_chan_clear_in_reconnect(ses, server);
4058 cifs_chan_clear_need_reconnect(ses, server);
4059 spin_unlock(&ses->chan_lock);
4060 spin_unlock(&ses->ses_lock);
4061 }
4062
4063 return rc;
4064 }
4065
4066 static int
cifs_set_vol_auth(struct smb3_fs_context * ctx,struct cifs_ses * ses)4067 cifs_set_vol_auth(struct smb3_fs_context *ctx, struct cifs_ses *ses)
4068 {
4069 ctx->sectype = ses->sectype;
4070
4071 /* krb5 is special, since we don't need username or pw */
4072 if (ctx->sectype == Kerberos)
4073 return 0;
4074
4075 return cifs_set_cifscreds(ctx, ses);
4076 }
4077
4078 static struct cifs_tcon *
cifs_construct_tcon(struct cifs_sb_info * cifs_sb,kuid_t fsuid)4079 cifs_construct_tcon(struct cifs_sb_info *cifs_sb, kuid_t fsuid)
4080 {
4081 int rc;
4082 struct cifs_tcon *master_tcon = cifs_sb_master_tcon(cifs_sb);
4083 struct cifs_ses *ses;
4084 struct cifs_tcon *tcon = NULL;
4085 struct smb3_fs_context *ctx;
4086 char *origin_fullpath = NULL;
4087
4088 ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
4089 if (ctx == NULL)
4090 return ERR_PTR(-ENOMEM);
4091
4092 ctx->local_nls = cifs_sb->local_nls;
4093 ctx->linux_uid = fsuid;
4094 ctx->cred_uid = fsuid;
4095 ctx->UNC = master_tcon->tree_name;
4096 ctx->retry = master_tcon->retry;
4097 ctx->nocase = master_tcon->nocase;
4098 ctx->nohandlecache = master_tcon->nohandlecache;
4099 ctx->local_lease = master_tcon->local_lease;
4100 ctx->no_lease = master_tcon->no_lease;
4101 ctx->resilient = master_tcon->use_resilient;
4102 ctx->persistent = master_tcon->use_persistent;
4103 ctx->handle_timeout = master_tcon->handle_timeout;
4104 ctx->no_linux_ext = !master_tcon->unix_ext;
4105 ctx->linux_ext = master_tcon->posix_extensions;
4106 ctx->sectype = master_tcon->ses->sectype;
4107 ctx->sign = master_tcon->ses->sign;
4108 ctx->seal = master_tcon->seal;
4109 ctx->witness = master_tcon->use_witness;
4110 ctx->dfs_root_ses = master_tcon->ses->dfs_root_ses;
4111
4112 rc = cifs_set_vol_auth(ctx, master_tcon->ses);
4113 if (rc) {
4114 tcon = ERR_PTR(rc);
4115 goto out;
4116 }
4117
4118 /* get a reference for the same TCP session */
4119 spin_lock(&cifs_tcp_ses_lock);
4120 ++master_tcon->ses->server->srv_count;
4121 spin_unlock(&cifs_tcp_ses_lock);
4122
4123 ses = cifs_get_smb_ses(master_tcon->ses->server, ctx);
4124 if (IS_ERR(ses)) {
4125 tcon = ERR_CAST(ses);
4126 cifs_put_tcp_session(master_tcon->ses->server, 0);
4127 goto out;
4128 }
4129
4130 #ifdef CONFIG_CIFS_DFS_UPCALL
4131 spin_lock(&master_tcon->tc_lock);
4132 if (master_tcon->origin_fullpath) {
4133 spin_unlock(&master_tcon->tc_lock);
4134 origin_fullpath = dfs_get_path(cifs_sb, cifs_sb->ctx->source);
4135 if (IS_ERR(origin_fullpath)) {
4136 tcon = ERR_CAST(origin_fullpath);
4137 origin_fullpath = NULL;
4138 cifs_put_smb_ses(ses);
4139 goto out;
4140 }
4141 } else {
4142 spin_unlock(&master_tcon->tc_lock);
4143 }
4144 #endif
4145
4146 tcon = cifs_get_tcon(ses, ctx);
4147 if (IS_ERR(tcon)) {
4148 cifs_put_smb_ses(ses);
4149 goto out;
4150 }
4151
4152 #ifdef CONFIG_CIFS_DFS_UPCALL
4153 if (origin_fullpath) {
4154 spin_lock(&tcon->tc_lock);
4155 tcon->origin_fullpath = origin_fullpath;
4156 spin_unlock(&tcon->tc_lock);
4157 origin_fullpath = NULL;
4158 queue_delayed_work(dfscache_wq, &tcon->dfs_cache_work,
4159 dfs_cache_get_ttl() * HZ);
4160 }
4161 #endif
4162
4163 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
4164 if (cap_unix(ses))
4165 reset_cifs_unix_caps(0, tcon, NULL, ctx);
4166 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
4167
4168 out:
4169 kfree(ctx->username);
4170 kfree_sensitive(ctx->password);
4171 kfree(origin_fullpath);
4172 kfree(ctx);
4173
4174 return tcon;
4175 }
4176
4177 struct cifs_tcon *
cifs_sb_master_tcon(struct cifs_sb_info * cifs_sb)4178 cifs_sb_master_tcon(struct cifs_sb_info *cifs_sb)
4179 {
4180 return tlink_tcon(cifs_sb_master_tlink(cifs_sb));
4181 }
4182
4183 /* find and return a tlink with given uid */
4184 static struct tcon_link *
tlink_rb_search(struct rb_root * root,kuid_t uid)4185 tlink_rb_search(struct rb_root *root, kuid_t uid)
4186 {
4187 struct rb_node *node = root->rb_node;
4188 struct tcon_link *tlink;
4189
4190 while (node) {
4191 tlink = rb_entry(node, struct tcon_link, tl_rbnode);
4192
4193 if (uid_gt(tlink->tl_uid, uid))
4194 node = node->rb_left;
4195 else if (uid_lt(tlink->tl_uid, uid))
4196 node = node->rb_right;
4197 else
4198 return tlink;
4199 }
4200 return NULL;
4201 }
4202
4203 /* insert a tcon_link into the tree */
4204 static void
tlink_rb_insert(struct rb_root * root,struct tcon_link * new_tlink)4205 tlink_rb_insert(struct rb_root *root, struct tcon_link *new_tlink)
4206 {
4207 struct rb_node **new = &(root->rb_node), *parent = NULL;
4208 struct tcon_link *tlink;
4209
4210 while (*new) {
4211 tlink = rb_entry(*new, struct tcon_link, tl_rbnode);
4212 parent = *new;
4213
4214 if (uid_gt(tlink->tl_uid, new_tlink->tl_uid))
4215 new = &((*new)->rb_left);
4216 else
4217 new = &((*new)->rb_right);
4218 }
4219
4220 rb_link_node(&new_tlink->tl_rbnode, parent, new);
4221 rb_insert_color(&new_tlink->tl_rbnode, root);
4222 }
4223
4224 /*
4225 * Find or construct an appropriate tcon given a cifs_sb and the fsuid of the
4226 * current task.
4227 *
4228 * If the superblock doesn't refer to a multiuser mount, then just return
4229 * the master tcon for the mount.
4230 *
4231 * First, search the rbtree for an existing tcon for this fsuid. If one
4232 * exists, then check to see if it's pending construction. If it is then wait
4233 * for construction to complete. Once it's no longer pending, check to see if
4234 * it failed and either return an error or retry construction, depending on
4235 * the timeout.
4236 *
4237 * If one doesn't exist then insert a new tcon_link struct into the tree and
4238 * try to construct a new one.
4239 *
4240 * REMEMBER to call cifs_put_tlink() after successful calls to cifs_sb_tlink,
4241 * to avoid refcount issues
4242 */
4243 struct tcon_link *
cifs_sb_tlink(struct cifs_sb_info * cifs_sb)4244 cifs_sb_tlink(struct cifs_sb_info *cifs_sb)
4245 {
4246 struct tcon_link *tlink, *newtlink;
4247 kuid_t fsuid = current_fsuid();
4248 int err;
4249
4250 if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER))
4251 return cifs_get_tlink(cifs_sb_master_tlink(cifs_sb));
4252
4253 spin_lock(&cifs_sb->tlink_tree_lock);
4254 tlink = tlink_rb_search(&cifs_sb->tlink_tree, fsuid);
4255 if (tlink)
4256 cifs_get_tlink(tlink);
4257 spin_unlock(&cifs_sb->tlink_tree_lock);
4258
4259 if (tlink == NULL) {
4260 newtlink = kzalloc(sizeof(*tlink), GFP_KERNEL);
4261 if (newtlink == NULL)
4262 return ERR_PTR(-ENOMEM);
4263 newtlink->tl_uid = fsuid;
4264 newtlink->tl_tcon = ERR_PTR(-EACCES);
4265 set_bit(TCON_LINK_PENDING, &newtlink->tl_flags);
4266 set_bit(TCON_LINK_IN_TREE, &newtlink->tl_flags);
4267 cifs_get_tlink(newtlink);
4268
4269 spin_lock(&cifs_sb->tlink_tree_lock);
4270 /* was one inserted after previous search? */
4271 tlink = tlink_rb_search(&cifs_sb->tlink_tree, fsuid);
4272 if (tlink) {
4273 cifs_get_tlink(tlink);
4274 spin_unlock(&cifs_sb->tlink_tree_lock);
4275 kfree(newtlink);
4276 goto wait_for_construction;
4277 }
4278 tlink = newtlink;
4279 tlink_rb_insert(&cifs_sb->tlink_tree, tlink);
4280 spin_unlock(&cifs_sb->tlink_tree_lock);
4281 } else {
4282 wait_for_construction:
4283 err = wait_on_bit(&tlink->tl_flags, TCON_LINK_PENDING,
4284 TASK_INTERRUPTIBLE);
4285 if (err) {
4286 cifs_put_tlink(tlink);
4287 return ERR_PTR(-ERESTARTSYS);
4288 }
4289
4290 /* if it's good, return it */
4291 if (!IS_ERR(tlink->tl_tcon))
4292 return tlink;
4293
4294 /* return error if we tried this already recently */
4295 if (time_before(jiffies, tlink->tl_time + TLINK_ERROR_EXPIRE)) {
4296 err = PTR_ERR(tlink->tl_tcon);
4297 cifs_put_tlink(tlink);
4298 return ERR_PTR(err);
4299 }
4300
4301 if (test_and_set_bit(TCON_LINK_PENDING, &tlink->tl_flags))
4302 goto wait_for_construction;
4303 }
4304
4305 tlink->tl_tcon = cifs_construct_tcon(cifs_sb, fsuid);
4306 clear_bit(TCON_LINK_PENDING, &tlink->tl_flags);
4307 wake_up_bit(&tlink->tl_flags, TCON_LINK_PENDING);
4308
4309 if (IS_ERR(tlink->tl_tcon)) {
4310 err = PTR_ERR(tlink->tl_tcon);
4311 if (err == -ENOKEY)
4312 err = -EACCES;
4313 cifs_put_tlink(tlink);
4314 return ERR_PTR(err);
4315 }
4316
4317 return tlink;
4318 }
4319
4320 /*
4321 * periodic workqueue job that scans tcon_tree for a superblock and closes
4322 * out tcons.
4323 */
4324 static void
cifs_prune_tlinks(struct work_struct * work)4325 cifs_prune_tlinks(struct work_struct *work)
4326 {
4327 struct cifs_sb_info *cifs_sb = container_of(work, struct cifs_sb_info,
4328 prune_tlinks.work);
4329 struct rb_root *root = &cifs_sb->tlink_tree;
4330 struct rb_node *node;
4331 struct rb_node *tmp;
4332 struct tcon_link *tlink;
4333
4334 /*
4335 * Because we drop the spinlock in the loop in order to put the tlink
4336 * it's not guarded against removal of links from the tree. The only
4337 * places that remove entries from the tree are this function and
4338 * umounts. Because this function is non-reentrant and is canceled
4339 * before umount can proceed, this is safe.
4340 */
4341 spin_lock(&cifs_sb->tlink_tree_lock);
4342 node = rb_first(root);
4343 while (node != NULL) {
4344 tmp = node;
4345 node = rb_next(tmp);
4346 tlink = rb_entry(tmp, struct tcon_link, tl_rbnode);
4347
4348 if (test_bit(TCON_LINK_MASTER, &tlink->tl_flags) ||
4349 atomic_read(&tlink->tl_count) != 0 ||
4350 time_after(tlink->tl_time + TLINK_IDLE_EXPIRE, jiffies))
4351 continue;
4352
4353 cifs_get_tlink(tlink);
4354 clear_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
4355 rb_erase(tmp, root);
4356
4357 spin_unlock(&cifs_sb->tlink_tree_lock);
4358 cifs_put_tlink(tlink);
4359 spin_lock(&cifs_sb->tlink_tree_lock);
4360 }
4361 spin_unlock(&cifs_sb->tlink_tree_lock);
4362
4363 queue_delayed_work(cifsiod_wq, &cifs_sb->prune_tlinks,
4364 TLINK_IDLE_EXPIRE);
4365 }
4366
4367 #ifndef CONFIG_CIFS_DFS_UPCALL
cifs_tree_connect(const unsigned int xid,struct cifs_tcon * tcon)4368 int cifs_tree_connect(const unsigned int xid, struct cifs_tcon *tcon)
4369 {
4370 const struct smb_version_operations *ops = tcon->ses->server->ops;
4371 int rc;
4372
4373 /* only send once per connect */
4374 spin_lock(&tcon->tc_lock);
4375
4376 /* if tcon is marked for needing reconnect, update state */
4377 if (tcon->need_reconnect)
4378 tcon->status = TID_NEED_TCON;
4379
4380 if (tcon->status == TID_GOOD) {
4381 spin_unlock(&tcon->tc_lock);
4382 return 0;
4383 }
4384
4385 if (tcon->status != TID_NEW &&
4386 tcon->status != TID_NEED_TCON) {
4387 spin_unlock(&tcon->tc_lock);
4388 return -EHOSTDOWN;
4389 }
4390
4391 tcon->status = TID_IN_TCON;
4392 spin_unlock(&tcon->tc_lock);
4393
4394 rc = ops->tree_connect(xid, tcon->ses, tcon->tree_name,
4395 tcon, tcon->ses->local_nls);
4396 if (rc) {
4397 spin_lock(&tcon->tc_lock);
4398 if (tcon->status == TID_IN_TCON)
4399 tcon->status = TID_NEED_TCON;
4400 spin_unlock(&tcon->tc_lock);
4401 } else {
4402 spin_lock(&tcon->tc_lock);
4403 if (tcon->status == TID_IN_TCON)
4404 tcon->status = TID_GOOD;
4405 tcon->need_reconnect = false;
4406 spin_unlock(&tcon->tc_lock);
4407 }
4408
4409 return rc;
4410 }
4411 #endif
4412