xref: /linux/fs/smb/client/connect.c (revision baa172c77ac52b2058ba3abae7512b7b16d0c461)
1 // SPDX-License-Identifier: LGPL-2.1
2 /*
3  *
4  *   Copyright (C) International Business Machines  Corp., 2002,2011
5  *   Author(s): Steve French (sfrench@us.ibm.com)
6  *
7  */
8 #include <linux/fs.h>
9 #include <linux/net.h>
10 #include <linux/string.h>
11 #include <linux/sched/mm.h>
12 #include <linux/sched/signal.h>
13 #include <linux/list.h>
14 #include <linux/wait.h>
15 #include <linux/slab.h>
16 #include <linux/pagemap.h>
17 #include <linux/ctype.h>
18 #include <linux/utsname.h>
19 #include <linux/mempool.h>
20 #include <linux/delay.h>
21 #include <linux/completion.h>
22 #include <linux/kthread.h>
23 #include <linux/pagevec.h>
24 #include <linux/freezer.h>
25 #include <linux/namei.h>
26 #include <linux/uuid.h>
27 #include <linux/uaccess.h>
28 #include <asm/processor.h>
29 #include <linux/inet.h>
30 #include <linux/module.h>
31 #include <keys/user-type.h>
32 #include <net/ipv6.h>
33 #include <linux/parser.h>
34 #include <linux/bvec.h>
35 #include "cifspdu.h"
36 #include "cifsglob.h"
37 #include "cifsproto.h"
38 #include "cifs_unicode.h"
39 #include "cifs_debug.h"
40 #include "cifs_fs_sb.h"
41 #include "ntlmssp.h"
42 #include "nterr.h"
43 #include "rfc1002pdu.h"
44 #include "fscache.h"
45 #include "smb2proto.h"
46 #include "smbdirect.h"
47 #include "dns_resolve.h"
48 #ifdef CONFIG_CIFS_DFS_UPCALL
49 #include "dfs.h"
50 #include "dfs_cache.h"
51 #endif
52 #include "fs_context.h"
53 #include "cifs_swn.h"
54 
55 /* FIXME: should these be tunable? */
56 #define TLINK_ERROR_EXPIRE	(1 * HZ)
57 #define TLINK_IDLE_EXPIRE	(600 * HZ)
58 
59 /* Drop the connection to not overload the server */
60 #define MAX_STATUS_IO_TIMEOUT   5
61 
62 static int ip_connect(struct TCP_Server_Info *server);
63 static int generic_ip_connect(struct TCP_Server_Info *server);
64 static void tlink_rb_insert(struct rb_root *root, struct tcon_link *new_tlink);
65 static void cifs_prune_tlinks(struct work_struct *work);
66 
67 /*
68  * Resolve hostname and set ip addr in tcp ses. Useful for hostnames that may
69  * get their ip addresses changed at some point.
70  *
71  * This should be called with server->srv_mutex held.
72  */
reconn_set_ipaddr_from_hostname(struct TCP_Server_Info * server)73 static int reconn_set_ipaddr_from_hostname(struct TCP_Server_Info *server)
74 {
75 	int rc;
76 	int len;
77 	char *unc;
78 	struct sockaddr_storage ss;
79 
80 	if (!server->hostname)
81 		return -EINVAL;
82 
83 	/* if server hostname isn't populated, there's nothing to do here */
84 	if (server->hostname[0] == '\0')
85 		return 0;
86 
87 	len = strlen(server->hostname) + 3;
88 
89 	unc = kmalloc(len, GFP_KERNEL);
90 	if (!unc) {
91 		cifs_dbg(FYI, "%s: failed to create UNC path\n", __func__);
92 		return -ENOMEM;
93 	}
94 	scnprintf(unc, len, "\\\\%s", server->hostname);
95 
96 	spin_lock(&server->srv_lock);
97 	ss = server->dstaddr;
98 	spin_unlock(&server->srv_lock);
99 
100 	rc = dns_resolve_server_name_to_ip(unc, (struct sockaddr *)&ss, NULL);
101 	kfree(unc);
102 
103 	if (rc < 0) {
104 		cifs_dbg(FYI, "%s: failed to resolve server part of %s to IP: %d\n",
105 			 __func__, server->hostname, rc);
106 	} else {
107 		spin_lock(&server->srv_lock);
108 		memcpy(&server->dstaddr, &ss, sizeof(server->dstaddr));
109 		spin_unlock(&server->srv_lock);
110 		rc = 0;
111 	}
112 
113 	return rc;
114 }
115 
smb2_query_server_interfaces(struct work_struct * work)116 static void smb2_query_server_interfaces(struct work_struct *work)
117 {
118 	int rc;
119 	int xid;
120 	struct cifs_tcon *tcon = container_of(work,
121 					struct cifs_tcon,
122 					query_interfaces.work);
123 	struct TCP_Server_Info *server = tcon->ses->server;
124 
125 	/*
126 	 * query server network interfaces, in case they change
127 	 */
128 	if (!server->ops->query_server_interfaces)
129 		return;
130 
131 	xid = get_xid();
132 	rc = server->ops->query_server_interfaces(xid, tcon, false);
133 	free_xid(xid);
134 
135 	if (rc) {
136 		if (rc == -EOPNOTSUPP)
137 			return;
138 
139 		cifs_dbg(FYI, "%s: failed to query server interfaces: %d\n",
140 				__func__, rc);
141 	}
142 
143 	queue_delayed_work(cifsiod_wq, &tcon->query_interfaces,
144 			   (SMB_INTERFACE_POLL_INTERVAL * HZ));
145 }
146 
147 /*
148  * Update the tcpStatus for the server.
149  * This is used to signal the cifsd thread to call cifs_reconnect
150  * ONLY cifsd thread should call cifs_reconnect. For any other
151  * thread, use this function
152  *
153  * @server: the tcp ses for which reconnect is needed
154  * @all_channels: if this needs to be done for all channels
155  */
156 void
cifs_signal_cifsd_for_reconnect(struct TCP_Server_Info * server,bool all_channels)157 cifs_signal_cifsd_for_reconnect(struct TCP_Server_Info *server,
158 				bool all_channels)
159 {
160 	struct TCP_Server_Info *pserver;
161 	struct cifs_ses *ses;
162 	int i;
163 
164 	/* If server is a channel, select the primary channel */
165 	pserver = SERVER_IS_CHAN(server) ? server->primary_server : server;
166 
167 	/* if we need to signal just this channel */
168 	if (!all_channels) {
169 		spin_lock(&server->srv_lock);
170 		if (server->tcpStatus != CifsExiting)
171 			server->tcpStatus = CifsNeedReconnect;
172 		spin_unlock(&server->srv_lock);
173 		return;
174 	}
175 
176 	spin_lock(&cifs_tcp_ses_lock);
177 	list_for_each_entry(ses, &pserver->smb_ses_list, smb_ses_list) {
178 		if (cifs_ses_exiting(ses))
179 			continue;
180 		spin_lock(&ses->chan_lock);
181 		for (i = 0; i < ses->chan_count; i++) {
182 			if (!ses->chans[i].server)
183 				continue;
184 
185 			spin_lock(&ses->chans[i].server->srv_lock);
186 			if (ses->chans[i].server->tcpStatus != CifsExiting)
187 				ses->chans[i].server->tcpStatus = CifsNeedReconnect;
188 			spin_unlock(&ses->chans[i].server->srv_lock);
189 		}
190 		spin_unlock(&ses->chan_lock);
191 	}
192 	spin_unlock(&cifs_tcp_ses_lock);
193 }
194 
195 /*
196  * Mark all sessions and tcons for reconnect.
197  * IMPORTANT: make sure that this gets called only from
198  * cifsd thread. For any other thread, use
199  * cifs_signal_cifsd_for_reconnect
200  *
201  * @server: the tcp ses for which reconnect is needed
202  * @server needs to be previously set to CifsNeedReconnect.
203  * @mark_smb_session: whether even sessions need to be marked
204  */
205 void
cifs_mark_tcp_ses_conns_for_reconnect(struct TCP_Server_Info * server,bool mark_smb_session)206 cifs_mark_tcp_ses_conns_for_reconnect(struct TCP_Server_Info *server,
207 				      bool mark_smb_session)
208 {
209 	struct TCP_Server_Info *pserver;
210 	struct cifs_ses *ses, *nses;
211 	struct cifs_tcon *tcon;
212 
213 	/*
214 	 * before reconnecting the tcp session, mark the smb session (uid) and the tid bad so they
215 	 * are not used until reconnected.
216 	 */
217 	cifs_dbg(FYI, "%s: marking necessary sessions and tcons for reconnect\n", __func__);
218 
219 	/* If server is a channel, select the primary channel */
220 	pserver = SERVER_IS_CHAN(server) ? server->primary_server : server;
221 
222 	/*
223 	 * if the server has been marked for termination, there is a
224 	 * chance that the remaining channels all need reconnect. To be
225 	 * on the safer side, mark the session and trees for reconnect
226 	 * for this scenario. This might cause a few redundant session
227 	 * setup and tree connect requests, but it is better than not doing
228 	 * a tree connect when needed, and all following requests failing
229 	 */
230 	if (server->terminate) {
231 		mark_smb_session = true;
232 		server = pserver;
233 	}
234 
235 	spin_lock(&cifs_tcp_ses_lock);
236 	list_for_each_entry_safe(ses, nses, &pserver->smb_ses_list, smb_ses_list) {
237 		spin_lock(&ses->ses_lock);
238 		if (ses->ses_status == SES_EXITING) {
239 			spin_unlock(&ses->ses_lock);
240 			continue;
241 		}
242 		spin_unlock(&ses->ses_lock);
243 
244 		spin_lock(&ses->chan_lock);
245 		if (cifs_ses_get_chan_index(ses, server) ==
246 		    CIFS_INVAL_CHAN_INDEX) {
247 			spin_unlock(&ses->chan_lock);
248 			continue;
249 		}
250 
251 		if (!cifs_chan_is_iface_active(ses, server)) {
252 			spin_unlock(&ses->chan_lock);
253 			cifs_chan_update_iface(ses, server);
254 			spin_lock(&ses->chan_lock);
255 		}
256 
257 		if (!mark_smb_session && cifs_chan_needs_reconnect(ses, server)) {
258 			spin_unlock(&ses->chan_lock);
259 			continue;
260 		}
261 
262 		if (mark_smb_session)
263 			CIFS_SET_ALL_CHANS_NEED_RECONNECT(ses);
264 		else
265 			cifs_chan_set_need_reconnect(ses, server);
266 
267 		cifs_dbg(FYI, "%s: channel connect bitmap: 0x%lx\n",
268 			 __func__, ses->chans_need_reconnect);
269 
270 		/* If all channels need reconnect, then tcon needs reconnect */
271 		if (!mark_smb_session && !CIFS_ALL_CHANS_NEED_RECONNECT(ses)) {
272 			spin_unlock(&ses->chan_lock);
273 			continue;
274 		}
275 		spin_unlock(&ses->chan_lock);
276 
277 		spin_lock(&ses->ses_lock);
278 		ses->ses_status = SES_NEED_RECON;
279 		spin_unlock(&ses->ses_lock);
280 
281 		list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
282 			tcon->need_reconnect = true;
283 			spin_lock(&tcon->tc_lock);
284 			tcon->status = TID_NEED_RECON;
285 			spin_unlock(&tcon->tc_lock);
286 
287 			cancel_delayed_work(&tcon->query_interfaces);
288 		}
289 		if (ses->tcon_ipc) {
290 			ses->tcon_ipc->need_reconnect = true;
291 			spin_lock(&ses->tcon_ipc->tc_lock);
292 			ses->tcon_ipc->status = TID_NEED_RECON;
293 			spin_unlock(&ses->tcon_ipc->tc_lock);
294 		}
295 	}
296 	spin_unlock(&cifs_tcp_ses_lock);
297 }
298 
299 static void
cifs_abort_connection(struct TCP_Server_Info * server)300 cifs_abort_connection(struct TCP_Server_Info *server)
301 {
302 	struct mid_q_entry *mid, *nmid;
303 	struct list_head retry_list;
304 
305 	server->maxBuf = 0;
306 	server->max_read = 0;
307 
308 	/* do not want to be sending data on a socket we are freeing */
309 	cifs_dbg(FYI, "%s: tearing down socket\n", __func__);
310 	cifs_server_lock(server);
311 	if (server->ssocket) {
312 		cifs_dbg(FYI, "State: 0x%x Flags: 0x%lx\n", server->ssocket->state,
313 			 server->ssocket->flags);
314 		kernel_sock_shutdown(server->ssocket, SHUT_WR);
315 		cifs_dbg(FYI, "Post shutdown state: 0x%x Flags: 0x%lx\n", server->ssocket->state,
316 			 server->ssocket->flags);
317 		sock_release(server->ssocket);
318 		server->ssocket = NULL;
319 	}
320 	server->sequence_number = 0;
321 	server->session_estab = false;
322 	kfree_sensitive(server->session_key.response);
323 	server->session_key.response = NULL;
324 	server->session_key.len = 0;
325 	server->lstrp = jiffies;
326 
327 	/* mark submitted MIDs for retry and issue callback */
328 	INIT_LIST_HEAD(&retry_list);
329 	cifs_dbg(FYI, "%s: moving mids to private list\n", __func__);
330 	spin_lock(&server->mid_lock);
331 	list_for_each_entry_safe(mid, nmid, &server->pending_mid_q, qhead) {
332 		kref_get(&mid->refcount);
333 		if (mid->mid_state == MID_REQUEST_SUBMITTED)
334 			mid->mid_state = MID_RETRY_NEEDED;
335 		list_move(&mid->qhead, &retry_list);
336 		mid->mid_flags |= MID_DELETED;
337 	}
338 	spin_unlock(&server->mid_lock);
339 	cifs_server_unlock(server);
340 
341 	cifs_dbg(FYI, "%s: issuing mid callbacks\n", __func__);
342 	list_for_each_entry_safe(mid, nmid, &retry_list, qhead) {
343 		list_del_init(&mid->qhead);
344 		mid->callback(mid);
345 		release_mid(mid);
346 	}
347 
348 	if (cifs_rdma_enabled(server)) {
349 		cifs_server_lock(server);
350 		smbd_destroy(server);
351 		cifs_server_unlock(server);
352 	}
353 }
354 
cifs_tcp_ses_needs_reconnect(struct TCP_Server_Info * server,int num_targets)355 static bool cifs_tcp_ses_needs_reconnect(struct TCP_Server_Info *server, int num_targets)
356 {
357 	spin_lock(&server->srv_lock);
358 	server->nr_targets = num_targets;
359 	if (server->tcpStatus == CifsExiting) {
360 		/* the demux thread will exit normally next time through the loop */
361 		spin_unlock(&server->srv_lock);
362 		wake_up(&server->response_q);
363 		return false;
364 	}
365 
366 	cifs_dbg(FYI, "Mark tcp session as need reconnect\n");
367 	trace_smb3_reconnect(server->CurrentMid, server->conn_id,
368 			     server->hostname);
369 	server->tcpStatus = CifsNeedReconnect;
370 
371 	spin_unlock(&server->srv_lock);
372 	return true;
373 }
374 
375 /*
376  * cifs tcp session reconnection
377  *
378  * mark tcp session as reconnecting so temporarily locked
379  * mark all smb sessions as reconnecting for tcp session
380  * reconnect tcp session
381  * wake up waiters on reconnection? - (not needed currently)
382  *
383  * if mark_smb_session is passed as true, unconditionally mark
384  * the smb session (and tcon) for reconnect as well. This value
385  * doesn't really matter for non-multichannel scenario.
386  *
387  */
__cifs_reconnect(struct TCP_Server_Info * server,bool mark_smb_session)388 static int __cifs_reconnect(struct TCP_Server_Info *server,
389 			    bool mark_smb_session)
390 {
391 	int rc = 0;
392 
393 	if (!cifs_tcp_ses_needs_reconnect(server, 1))
394 		return 0;
395 
396 	cifs_mark_tcp_ses_conns_for_reconnect(server, mark_smb_session);
397 
398 	cifs_abort_connection(server);
399 
400 	do {
401 		try_to_freeze();
402 		cifs_server_lock(server);
403 
404 		if (!cifs_swn_set_server_dstaddr(server)) {
405 			/* resolve the hostname again to make sure that IP address is up-to-date */
406 			rc = reconn_set_ipaddr_from_hostname(server);
407 			cifs_dbg(FYI, "%s: reconn_set_ipaddr_from_hostname: rc=%d\n", __func__, rc);
408 		}
409 
410 		if (cifs_rdma_enabled(server))
411 			rc = smbd_reconnect(server);
412 		else
413 			rc = generic_ip_connect(server);
414 		if (rc) {
415 			cifs_server_unlock(server);
416 			cifs_dbg(FYI, "%s: reconnect error %d\n", __func__, rc);
417 			msleep(3000);
418 		} else {
419 			atomic_inc(&tcpSesReconnectCount);
420 			set_credits(server, 1);
421 			spin_lock(&server->srv_lock);
422 			if (server->tcpStatus != CifsExiting)
423 				server->tcpStatus = CifsNeedNegotiate;
424 			spin_unlock(&server->srv_lock);
425 			cifs_swn_reset_server_dstaddr(server);
426 			cifs_server_unlock(server);
427 			mod_delayed_work(cifsiod_wq, &server->reconnect, 0);
428 		}
429 	} while (server->tcpStatus == CifsNeedReconnect);
430 
431 	spin_lock(&server->srv_lock);
432 	if (server->tcpStatus == CifsNeedNegotiate)
433 		mod_delayed_work(cifsiod_wq, &server->echo, 0);
434 	spin_unlock(&server->srv_lock);
435 
436 	wake_up(&server->response_q);
437 	return rc;
438 }
439 
440 #ifdef CONFIG_CIFS_DFS_UPCALL
__reconnect_target_unlocked(struct TCP_Server_Info * server,const char * target)441 static int __reconnect_target_unlocked(struct TCP_Server_Info *server, const char *target)
442 {
443 	int rc;
444 	char *hostname;
445 
446 	if (!cifs_swn_set_server_dstaddr(server)) {
447 		if (server->hostname != target) {
448 			hostname = extract_hostname(target);
449 			if (!IS_ERR(hostname)) {
450 				spin_lock(&server->srv_lock);
451 				kfree(server->hostname);
452 				server->hostname = hostname;
453 				spin_unlock(&server->srv_lock);
454 			} else {
455 				cifs_dbg(FYI, "%s: couldn't extract hostname or address from dfs target: %ld\n",
456 					 __func__, PTR_ERR(hostname));
457 				cifs_dbg(FYI, "%s: default to last target server: %s\n", __func__,
458 					 server->hostname);
459 			}
460 		}
461 		/* resolve the hostname again to make sure that IP address is up-to-date. */
462 		rc = reconn_set_ipaddr_from_hostname(server);
463 		cifs_dbg(FYI, "%s: reconn_set_ipaddr_from_hostname: rc=%d\n", __func__, rc);
464 	}
465 	/* Reconnect the socket */
466 	if (cifs_rdma_enabled(server))
467 		rc = smbd_reconnect(server);
468 	else
469 		rc = generic_ip_connect(server);
470 
471 	return rc;
472 }
473 
reconnect_target_unlocked(struct TCP_Server_Info * server,struct dfs_cache_tgt_list * tl,struct dfs_cache_tgt_iterator ** target_hint)474 static int reconnect_target_unlocked(struct TCP_Server_Info *server, struct dfs_cache_tgt_list *tl,
475 				     struct dfs_cache_tgt_iterator **target_hint)
476 {
477 	int rc;
478 	struct dfs_cache_tgt_iterator *tit;
479 
480 	*target_hint = NULL;
481 
482 	/* If dfs target list is empty, then reconnect to last server */
483 	tit = dfs_cache_get_tgt_iterator(tl);
484 	if (!tit)
485 		return __reconnect_target_unlocked(server, server->hostname);
486 
487 	/* Otherwise, try every dfs target in @tl */
488 	for (; tit; tit = dfs_cache_get_next_tgt(tl, tit)) {
489 		rc = __reconnect_target_unlocked(server, dfs_cache_get_tgt_name(tit));
490 		if (!rc) {
491 			*target_hint = tit;
492 			break;
493 		}
494 	}
495 	return rc;
496 }
497 
reconnect_dfs_server(struct TCP_Server_Info * server)498 static int reconnect_dfs_server(struct TCP_Server_Info *server)
499 {
500 	struct dfs_cache_tgt_iterator *target_hint = NULL;
501 
502 	DFS_CACHE_TGT_LIST(tl);
503 	int num_targets = 0;
504 	int rc = 0;
505 
506 	/*
507 	 * Determine the number of dfs targets the referral path in @cifs_sb resolves to.
508 	 *
509 	 * smb2_reconnect() needs to know how long it should wait based upon the number of dfs
510 	 * targets (server->nr_targets).  It's also possible that the cached referral was cleared
511 	 * through /proc/fs/cifs/dfscache or the target list is empty due to server settings after
512 	 * refreshing the referral, so, in this case, default it to 1.
513 	 */
514 	mutex_lock(&server->refpath_lock);
515 	if (!dfs_cache_noreq_find(server->leaf_fullpath + 1, NULL, &tl))
516 		num_targets = dfs_cache_get_nr_tgts(&tl);
517 	mutex_unlock(&server->refpath_lock);
518 	if (!num_targets)
519 		num_targets = 1;
520 
521 	if (!cifs_tcp_ses_needs_reconnect(server, num_targets))
522 		return 0;
523 
524 	/*
525 	 * Unconditionally mark all sessions & tcons for reconnect as we might be connecting to a
526 	 * different server or share during failover.  It could be improved by adding some logic to
527 	 * only do that in case it connects to a different server or share, though.
528 	 */
529 	cifs_mark_tcp_ses_conns_for_reconnect(server, true);
530 
531 	cifs_abort_connection(server);
532 
533 	do {
534 		try_to_freeze();
535 		cifs_server_lock(server);
536 
537 		rc = reconnect_target_unlocked(server, &tl, &target_hint);
538 		if (rc) {
539 			/* Failed to reconnect socket */
540 			cifs_server_unlock(server);
541 			cifs_dbg(FYI, "%s: reconnect error %d\n", __func__, rc);
542 			msleep(3000);
543 			continue;
544 		}
545 		/*
546 		 * Socket was created.  Update tcp session status to CifsNeedNegotiate so that a
547 		 * process waiting for reconnect will know it needs to re-establish session and tcon
548 		 * through the reconnected target server.
549 		 */
550 		atomic_inc(&tcpSesReconnectCount);
551 		set_credits(server, 1);
552 		spin_lock(&server->srv_lock);
553 		if (server->tcpStatus != CifsExiting)
554 			server->tcpStatus = CifsNeedNegotiate;
555 		spin_unlock(&server->srv_lock);
556 		cifs_swn_reset_server_dstaddr(server);
557 		cifs_server_unlock(server);
558 		mod_delayed_work(cifsiod_wq, &server->reconnect, 0);
559 	} while (server->tcpStatus == CifsNeedReconnect);
560 
561 	mutex_lock(&server->refpath_lock);
562 	dfs_cache_noreq_update_tgthint(server->leaf_fullpath + 1, target_hint);
563 	mutex_unlock(&server->refpath_lock);
564 	dfs_cache_free_tgts(&tl);
565 
566 	/* Need to set up echo worker again once connection has been established */
567 	spin_lock(&server->srv_lock);
568 	if (server->tcpStatus == CifsNeedNegotiate)
569 		mod_delayed_work(cifsiod_wq, &server->echo, 0);
570 	spin_unlock(&server->srv_lock);
571 
572 	wake_up(&server->response_q);
573 	return rc;
574 }
575 
cifs_reconnect(struct TCP_Server_Info * server,bool mark_smb_session)576 int cifs_reconnect(struct TCP_Server_Info *server, bool mark_smb_session)
577 {
578 	mutex_lock(&server->refpath_lock);
579 	if (!server->leaf_fullpath) {
580 		mutex_unlock(&server->refpath_lock);
581 		return __cifs_reconnect(server, mark_smb_session);
582 	}
583 	mutex_unlock(&server->refpath_lock);
584 
585 	return reconnect_dfs_server(server);
586 }
587 #else
cifs_reconnect(struct TCP_Server_Info * server,bool mark_smb_session)588 int cifs_reconnect(struct TCP_Server_Info *server, bool mark_smb_session)
589 {
590 	return __cifs_reconnect(server, mark_smb_session);
591 }
592 #endif
593 
594 static void
cifs_echo_request(struct work_struct * work)595 cifs_echo_request(struct work_struct *work)
596 {
597 	int rc;
598 	struct TCP_Server_Info *server = container_of(work,
599 					struct TCP_Server_Info, echo.work);
600 
601 	/*
602 	 * We cannot send an echo if it is disabled.
603 	 * Also, no need to ping if we got a response recently.
604 	 */
605 
606 	if (server->tcpStatus == CifsNeedReconnect ||
607 	    server->tcpStatus == CifsExiting ||
608 	    server->tcpStatus == CifsNew ||
609 	    (server->ops->can_echo && !server->ops->can_echo(server)) ||
610 	    time_before(jiffies, server->lstrp + server->echo_interval - HZ))
611 		goto requeue_echo;
612 
613 	rc = server->ops->echo ? server->ops->echo(server) : -ENOSYS;
614 	cifs_server_dbg(FYI, "send echo request: rc = %d\n", rc);
615 
616 	/* Check witness registrations */
617 	cifs_swn_check();
618 
619 requeue_echo:
620 	queue_delayed_work(cifsiod_wq, &server->echo, server->echo_interval);
621 }
622 
623 static bool
allocate_buffers(struct TCP_Server_Info * server)624 allocate_buffers(struct TCP_Server_Info *server)
625 {
626 	if (!server->bigbuf) {
627 		server->bigbuf = (char *)cifs_buf_get();
628 		if (!server->bigbuf) {
629 			cifs_server_dbg(VFS, "No memory for large SMB response\n");
630 			msleep(3000);
631 			/* retry will check if exiting */
632 			return false;
633 		}
634 	} else if (server->large_buf) {
635 		/* we are reusing a dirty large buf, clear its start */
636 		memset(server->bigbuf, 0, HEADER_SIZE(server));
637 	}
638 
639 	if (!server->smallbuf) {
640 		server->smallbuf = (char *)cifs_small_buf_get();
641 		if (!server->smallbuf) {
642 			cifs_server_dbg(VFS, "No memory for SMB response\n");
643 			msleep(1000);
644 			/* retry will check if exiting */
645 			return false;
646 		}
647 		/* beginning of smb buffer is cleared in our buf_get */
648 	} else {
649 		/* if existing small buf clear beginning */
650 		memset(server->smallbuf, 0, HEADER_SIZE(server));
651 	}
652 
653 	return true;
654 }
655 
656 static bool
server_unresponsive(struct TCP_Server_Info * server)657 server_unresponsive(struct TCP_Server_Info *server)
658 {
659 	/*
660 	 * If we're in the process of mounting a share or reconnecting a session
661 	 * and the server abruptly shut down (e.g. socket wasn't closed, packet
662 	 * had been ACK'ed but no SMB response), don't wait longer than 20s to
663 	 * negotiate protocol.
664 	 */
665 	spin_lock(&server->srv_lock);
666 	if (server->tcpStatus == CifsInNegotiate &&
667 	    time_after(jiffies, server->lstrp + 20 * HZ)) {
668 		spin_unlock(&server->srv_lock);
669 		cifs_reconnect(server, false);
670 		return true;
671 	}
672 	/*
673 	 * We need to wait 3 echo intervals to make sure we handle such
674 	 * situations right:
675 	 * 1s  client sends a normal SMB request
676 	 * 2s  client gets a response
677 	 * 30s echo workqueue job pops, and decides we got a response recently
678 	 *     and don't need to send another
679 	 * ...
680 	 * 65s kernel_recvmsg times out, and we see that we haven't gotten
681 	 *     a response in >60s.
682 	 */
683 	if ((server->tcpStatus == CifsGood ||
684 	    server->tcpStatus == CifsNeedNegotiate) &&
685 	    (!server->ops->can_echo || server->ops->can_echo(server)) &&
686 	    time_after(jiffies, server->lstrp + 3 * server->echo_interval)) {
687 		spin_unlock(&server->srv_lock);
688 		cifs_server_dbg(VFS, "has not responded in %lu seconds. Reconnecting...\n",
689 			 (3 * server->echo_interval) / HZ);
690 		cifs_reconnect(server, false);
691 		return true;
692 	}
693 	spin_unlock(&server->srv_lock);
694 
695 	return false;
696 }
697 
698 static inline bool
zero_credits(struct TCP_Server_Info * server)699 zero_credits(struct TCP_Server_Info *server)
700 {
701 	int val;
702 
703 	spin_lock(&server->req_lock);
704 	val = server->credits + server->echo_credits + server->oplock_credits;
705 	if (server->in_flight == 0 && val == 0) {
706 		spin_unlock(&server->req_lock);
707 		return true;
708 	}
709 	spin_unlock(&server->req_lock);
710 	return false;
711 }
712 
713 static int
cifs_readv_from_socket(struct TCP_Server_Info * server,struct msghdr * smb_msg)714 cifs_readv_from_socket(struct TCP_Server_Info *server, struct msghdr *smb_msg)
715 {
716 	int length = 0;
717 	int total_read;
718 
719 	for (total_read = 0; msg_data_left(smb_msg); total_read += length) {
720 		try_to_freeze();
721 
722 		/* reconnect if no credits and no requests in flight */
723 		if (zero_credits(server)) {
724 			cifs_reconnect(server, false);
725 			return -ECONNABORTED;
726 		}
727 
728 		if (server_unresponsive(server))
729 			return -ECONNABORTED;
730 		if (cifs_rdma_enabled(server) && server->smbd_conn)
731 			length = smbd_recv(server->smbd_conn, smb_msg);
732 		else
733 			length = sock_recvmsg(server->ssocket, smb_msg, 0);
734 
735 		spin_lock(&server->srv_lock);
736 		if (server->tcpStatus == CifsExiting) {
737 			spin_unlock(&server->srv_lock);
738 			return -ESHUTDOWN;
739 		}
740 
741 		if (server->tcpStatus == CifsNeedReconnect) {
742 			spin_unlock(&server->srv_lock);
743 			cifs_reconnect(server, false);
744 			return -ECONNABORTED;
745 		}
746 		spin_unlock(&server->srv_lock);
747 
748 		if (length == -ERESTARTSYS ||
749 		    length == -EAGAIN ||
750 		    length == -EINTR) {
751 			/*
752 			 * Minimum sleep to prevent looping, allowing socket
753 			 * to clear and app threads to set tcpStatus
754 			 * CifsNeedReconnect if server hung.
755 			 */
756 			usleep_range(1000, 2000);
757 			length = 0;
758 			continue;
759 		}
760 
761 		if (length <= 0) {
762 			cifs_dbg(FYI, "Received no data or error: %d\n", length);
763 			cifs_reconnect(server, false);
764 			return -ECONNABORTED;
765 		}
766 	}
767 	return total_read;
768 }
769 
770 int
cifs_read_from_socket(struct TCP_Server_Info * server,char * buf,unsigned int to_read)771 cifs_read_from_socket(struct TCP_Server_Info *server, char *buf,
772 		      unsigned int to_read)
773 {
774 	struct msghdr smb_msg = {};
775 	struct kvec iov = {.iov_base = buf, .iov_len = to_read};
776 
777 	iov_iter_kvec(&smb_msg.msg_iter, ITER_DEST, &iov, 1, to_read);
778 
779 	return cifs_readv_from_socket(server, &smb_msg);
780 }
781 
782 ssize_t
cifs_discard_from_socket(struct TCP_Server_Info * server,size_t to_read)783 cifs_discard_from_socket(struct TCP_Server_Info *server, size_t to_read)
784 {
785 	struct msghdr smb_msg = {};
786 
787 	/*
788 	 *  iov_iter_discard already sets smb_msg.type and count and iov_offset
789 	 *  and cifs_readv_from_socket sets msg_control and msg_controllen
790 	 *  so little to initialize in struct msghdr
791 	 */
792 	iov_iter_discard(&smb_msg.msg_iter, ITER_DEST, to_read);
793 
794 	return cifs_readv_from_socket(server, &smb_msg);
795 }
796 
797 int
cifs_read_iter_from_socket(struct TCP_Server_Info * server,struct iov_iter * iter,unsigned int to_read)798 cifs_read_iter_from_socket(struct TCP_Server_Info *server, struct iov_iter *iter,
799 			   unsigned int to_read)
800 {
801 	struct msghdr smb_msg = { .msg_iter = *iter };
802 
803 	iov_iter_truncate(&smb_msg.msg_iter, to_read);
804 	return cifs_readv_from_socket(server, &smb_msg);
805 }
806 
807 static bool
is_smb_response(struct TCP_Server_Info * server,unsigned char type)808 is_smb_response(struct TCP_Server_Info *server, unsigned char type)
809 {
810 	/*
811 	 * The first byte big endian of the length field,
812 	 * is actually not part of the length but the type
813 	 * with the most common, zero, as regular data.
814 	 */
815 	switch (type) {
816 	case RFC1002_SESSION_MESSAGE:
817 		/* Regular SMB response */
818 		return true;
819 	case RFC1002_SESSION_KEEP_ALIVE:
820 		cifs_dbg(FYI, "RFC 1002 session keep alive\n");
821 		break;
822 	case RFC1002_POSITIVE_SESSION_RESPONSE:
823 		cifs_dbg(FYI, "RFC 1002 positive session response\n");
824 		break;
825 	case RFC1002_NEGATIVE_SESSION_RESPONSE:
826 		/*
827 		 * We get this from Windows 98 instead of an error on
828 		 * SMB negprot response.
829 		 */
830 		cifs_dbg(FYI, "RFC 1002 negative session response\n");
831 		/* give server a second to clean up */
832 		msleep(1000);
833 		/*
834 		 * Always try 445 first on reconnect since we get NACK
835 		 * on some if we ever connected to port 139 (the NACK
836 		 * is since we do not begin with RFC1001 session
837 		 * initialize frame).
838 		 */
839 		cifs_set_port((struct sockaddr *)&server->dstaddr, CIFS_PORT);
840 		cifs_reconnect(server, true);
841 		break;
842 	default:
843 		cifs_server_dbg(VFS, "RFC 1002 unknown response type 0x%x\n", type);
844 		cifs_reconnect(server, true);
845 	}
846 
847 	return false;
848 }
849 
850 void
dequeue_mid(struct mid_q_entry * mid,bool malformed)851 dequeue_mid(struct mid_q_entry *mid, bool malformed)
852 {
853 #ifdef CONFIG_CIFS_STATS2
854 	mid->when_received = jiffies;
855 #endif
856 	spin_lock(&mid->server->mid_lock);
857 	if (!malformed)
858 		mid->mid_state = MID_RESPONSE_RECEIVED;
859 	else
860 		mid->mid_state = MID_RESPONSE_MALFORMED;
861 	/*
862 	 * Trying to handle/dequeue a mid after the send_recv()
863 	 * function has finished processing it is a bug.
864 	 */
865 	if (mid->mid_flags & MID_DELETED) {
866 		spin_unlock(&mid->server->mid_lock);
867 		pr_warn_once("trying to dequeue a deleted mid\n");
868 	} else {
869 		list_del_init(&mid->qhead);
870 		mid->mid_flags |= MID_DELETED;
871 		spin_unlock(&mid->server->mid_lock);
872 	}
873 }
874 
875 static unsigned int
smb2_get_credits_from_hdr(char * buffer,struct TCP_Server_Info * server)876 smb2_get_credits_from_hdr(char *buffer, struct TCP_Server_Info *server)
877 {
878 	struct smb2_hdr *shdr = (struct smb2_hdr *)buffer;
879 
880 	/*
881 	 * SMB1 does not use credits.
882 	 */
883 	if (is_smb1(server))
884 		return 0;
885 
886 	return le16_to_cpu(shdr->CreditRequest);
887 }
888 
889 static void
handle_mid(struct mid_q_entry * mid,struct TCP_Server_Info * server,char * buf,int malformed)890 handle_mid(struct mid_q_entry *mid, struct TCP_Server_Info *server,
891 	   char *buf, int malformed)
892 {
893 	if (server->ops->check_trans2 &&
894 	    server->ops->check_trans2(mid, server, buf, malformed))
895 		return;
896 	mid->credits_received = smb2_get_credits_from_hdr(buf, server);
897 	mid->resp_buf = buf;
898 	mid->large_buf = server->large_buf;
899 	/* Was previous buf put in mpx struct for multi-rsp? */
900 	if (!mid->multiRsp) {
901 		/* smb buffer will be freed by user thread */
902 		if (server->large_buf)
903 			server->bigbuf = NULL;
904 		else
905 			server->smallbuf = NULL;
906 	}
907 	dequeue_mid(mid, malformed);
908 }
909 
910 int
cifs_enable_signing(struct TCP_Server_Info * server,bool mnt_sign_required)911 cifs_enable_signing(struct TCP_Server_Info *server, bool mnt_sign_required)
912 {
913 	bool srv_sign_required = server->sec_mode & server->vals->signing_required;
914 	bool srv_sign_enabled = server->sec_mode & server->vals->signing_enabled;
915 	bool mnt_sign_enabled;
916 
917 	/*
918 	 * Is signing required by mnt options? If not then check
919 	 * global_secflags to see if it is there.
920 	 */
921 	if (!mnt_sign_required)
922 		mnt_sign_required = ((global_secflags & CIFSSEC_MUST_SIGN) ==
923 						CIFSSEC_MUST_SIGN);
924 
925 	/*
926 	 * If signing is required then it's automatically enabled too,
927 	 * otherwise, check to see if the secflags allow it.
928 	 */
929 	mnt_sign_enabled = mnt_sign_required ? mnt_sign_required :
930 				(global_secflags & CIFSSEC_MAY_SIGN);
931 
932 	/* If server requires signing, does client allow it? */
933 	if (srv_sign_required) {
934 		if (!mnt_sign_enabled) {
935 			cifs_dbg(VFS, "Server requires signing, but it's disabled in SecurityFlags!\n");
936 			return -EOPNOTSUPP;
937 		}
938 		server->sign = true;
939 	}
940 
941 	/* If client requires signing, does server allow it? */
942 	if (mnt_sign_required) {
943 		if (!srv_sign_enabled) {
944 			cifs_dbg(VFS, "Server does not support signing!\n");
945 			return -EOPNOTSUPP;
946 		}
947 		server->sign = true;
948 	}
949 
950 	if (cifs_rdma_enabled(server) && server->sign)
951 		cifs_dbg(VFS, "Signing is enabled, and RDMA read/write will be disabled\n");
952 
953 	return 0;
954 }
955 
956 static noinline_for_stack void
clean_demultiplex_info(struct TCP_Server_Info * server)957 clean_demultiplex_info(struct TCP_Server_Info *server)
958 {
959 	int length;
960 
961 	/* take it off the list, if it's not already */
962 	spin_lock(&server->srv_lock);
963 	list_del_init(&server->tcp_ses_list);
964 	spin_unlock(&server->srv_lock);
965 
966 	cancel_delayed_work_sync(&server->echo);
967 
968 	spin_lock(&server->srv_lock);
969 	server->tcpStatus = CifsExiting;
970 	spin_unlock(&server->srv_lock);
971 	wake_up_all(&server->response_q);
972 
973 	/* check if we have blocked requests that need to free */
974 	spin_lock(&server->req_lock);
975 	if (server->credits <= 0)
976 		server->credits = 1;
977 	spin_unlock(&server->req_lock);
978 	/*
979 	 * Although there should not be any requests blocked on this queue it
980 	 * can not hurt to be paranoid and try to wake up requests that may
981 	 * haven been blocked when more than 50 at time were on the wire to the
982 	 * same server - they now will see the session is in exit state and get
983 	 * out of SendReceive.
984 	 */
985 	wake_up_all(&server->request_q);
986 	/* give those requests time to exit */
987 	msleep(125);
988 	if (cifs_rdma_enabled(server))
989 		smbd_destroy(server);
990 
991 	if (server->ssocket) {
992 		sock_release(server->ssocket);
993 		server->ssocket = NULL;
994 
995 		/* Release netns reference for the socket. */
996 		put_net(cifs_net_ns(server));
997 	}
998 
999 	if (!list_empty(&server->pending_mid_q)) {
1000 		struct mid_q_entry *mid_entry;
1001 		struct list_head *tmp, *tmp2;
1002 		LIST_HEAD(dispose_list);
1003 
1004 		spin_lock(&server->mid_lock);
1005 		list_for_each_safe(tmp, tmp2, &server->pending_mid_q) {
1006 			mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
1007 			cifs_dbg(FYI, "Clearing mid %llu\n", mid_entry->mid);
1008 			kref_get(&mid_entry->refcount);
1009 			mid_entry->mid_state = MID_SHUTDOWN;
1010 			list_move(&mid_entry->qhead, &dispose_list);
1011 			mid_entry->mid_flags |= MID_DELETED;
1012 		}
1013 		spin_unlock(&server->mid_lock);
1014 
1015 		/* now walk dispose list and issue callbacks */
1016 		list_for_each_safe(tmp, tmp2, &dispose_list) {
1017 			mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
1018 			cifs_dbg(FYI, "Callback mid %llu\n", mid_entry->mid);
1019 			list_del_init(&mid_entry->qhead);
1020 			mid_entry->callback(mid_entry);
1021 			release_mid(mid_entry);
1022 		}
1023 		/* 1/8th of sec is more than enough time for them to exit */
1024 		msleep(125);
1025 	}
1026 
1027 	if (!list_empty(&server->pending_mid_q)) {
1028 		/*
1029 		 * mpx threads have not exited yet give them at least the smb
1030 		 * send timeout time for long ops.
1031 		 *
1032 		 * Due to delays on oplock break requests, we need to wait at
1033 		 * least 45 seconds before giving up on a request getting a
1034 		 * response and going ahead and killing cifsd.
1035 		 */
1036 		cifs_dbg(FYI, "Wait for exit from demultiplex thread\n");
1037 		msleep(46000);
1038 		/*
1039 		 * If threads still have not exited they are probably never
1040 		 * coming home not much else we can do but free the memory.
1041 		 */
1042 	}
1043 
1044 	/* Release netns reference for this server. */
1045 	put_net(cifs_net_ns(server));
1046 	kfree(server->leaf_fullpath);
1047 	kfree(server);
1048 
1049 	length = atomic_dec_return(&tcpSesAllocCount);
1050 	if (length > 0)
1051 		mempool_resize(cifs_req_poolp, length + cifs_min_rcv);
1052 }
1053 
1054 static int
standard_receive3(struct TCP_Server_Info * server,struct mid_q_entry * mid)1055 standard_receive3(struct TCP_Server_Info *server, struct mid_q_entry *mid)
1056 {
1057 	int length;
1058 	char *buf = server->smallbuf;
1059 	unsigned int pdu_length = server->pdu_size;
1060 
1061 	/* make sure this will fit in a large buffer */
1062 	if (pdu_length > CIFSMaxBufSize + MAX_HEADER_SIZE(server) -
1063 	    HEADER_PREAMBLE_SIZE(server)) {
1064 		cifs_server_dbg(VFS, "SMB response too long (%u bytes)\n", pdu_length);
1065 		cifs_reconnect(server, true);
1066 		return -ECONNABORTED;
1067 	}
1068 
1069 	/* switch to large buffer if too big for a small one */
1070 	if (pdu_length > MAX_CIFS_SMALL_BUFFER_SIZE - 4) {
1071 		server->large_buf = true;
1072 		memcpy(server->bigbuf, buf, server->total_read);
1073 		buf = server->bigbuf;
1074 	}
1075 
1076 	/* now read the rest */
1077 	length = cifs_read_from_socket(server, buf + HEADER_SIZE(server) - 1,
1078 				       pdu_length - MID_HEADER_SIZE(server));
1079 
1080 	if (length < 0)
1081 		return length;
1082 	server->total_read += length;
1083 
1084 	dump_smb(buf, server->total_read);
1085 
1086 	return cifs_handle_standard(server, mid);
1087 }
1088 
1089 int
cifs_handle_standard(struct TCP_Server_Info * server,struct mid_q_entry * mid)1090 cifs_handle_standard(struct TCP_Server_Info *server, struct mid_q_entry *mid)
1091 {
1092 	char *buf = server->large_buf ? server->bigbuf : server->smallbuf;
1093 	int rc;
1094 
1095 	/*
1096 	 * We know that we received enough to get to the MID as we
1097 	 * checked the pdu_length earlier. Now check to see
1098 	 * if the rest of the header is OK.
1099 	 *
1100 	 * 48 bytes is enough to display the header and a little bit
1101 	 * into the payload for debugging purposes.
1102 	 */
1103 	rc = server->ops->check_message(buf, server->total_read, server);
1104 	if (rc)
1105 		cifs_dump_mem("Bad SMB: ", buf,
1106 			min_t(unsigned int, server->total_read, 48));
1107 
1108 	if (server->ops->is_session_expired &&
1109 	    server->ops->is_session_expired(buf)) {
1110 		cifs_reconnect(server, true);
1111 		return -1;
1112 	}
1113 
1114 	if (server->ops->is_status_pending &&
1115 	    server->ops->is_status_pending(buf, server))
1116 		return -1;
1117 
1118 	if (!mid)
1119 		return rc;
1120 
1121 	handle_mid(mid, server, buf, rc);
1122 	return 0;
1123 }
1124 
1125 static void
smb2_add_credits_from_hdr(char * buffer,struct TCP_Server_Info * server)1126 smb2_add_credits_from_hdr(char *buffer, struct TCP_Server_Info *server)
1127 {
1128 	struct smb2_hdr *shdr = (struct smb2_hdr *)buffer;
1129 	int scredits, in_flight;
1130 
1131 	/*
1132 	 * SMB1 does not use credits.
1133 	 */
1134 	if (is_smb1(server))
1135 		return;
1136 
1137 	if (shdr->CreditRequest) {
1138 		spin_lock(&server->req_lock);
1139 		server->credits += le16_to_cpu(shdr->CreditRequest);
1140 		scredits = server->credits;
1141 		in_flight = server->in_flight;
1142 		spin_unlock(&server->req_lock);
1143 		wake_up(&server->request_q);
1144 
1145 		trace_smb3_hdr_credits(server->CurrentMid,
1146 				server->conn_id, server->hostname, scredits,
1147 				le16_to_cpu(shdr->CreditRequest), in_flight);
1148 		cifs_server_dbg(FYI, "%s: added %u credits total=%d\n",
1149 				__func__, le16_to_cpu(shdr->CreditRequest),
1150 				scredits);
1151 	}
1152 }
1153 
1154 
1155 static int
cifs_demultiplex_thread(void * p)1156 cifs_demultiplex_thread(void *p)
1157 {
1158 	int i, num_mids, length;
1159 	struct TCP_Server_Info *server = p;
1160 	unsigned int pdu_length;
1161 	unsigned int next_offset;
1162 	char *buf = NULL;
1163 	struct task_struct *task_to_wake = NULL;
1164 	struct mid_q_entry *mids[MAX_COMPOUND];
1165 	char *bufs[MAX_COMPOUND];
1166 	unsigned int noreclaim_flag, num_io_timeout = 0;
1167 	bool pending_reconnect = false;
1168 
1169 	noreclaim_flag = memalloc_noreclaim_save();
1170 	cifs_dbg(FYI, "Demultiplex PID: %d\n", task_pid_nr(current));
1171 
1172 	length = atomic_inc_return(&tcpSesAllocCount);
1173 	if (length > 1)
1174 		mempool_resize(cifs_req_poolp, length + cifs_min_rcv);
1175 
1176 	set_freezable();
1177 	allow_kernel_signal(SIGKILL);
1178 	while (server->tcpStatus != CifsExiting) {
1179 		if (try_to_freeze())
1180 			continue;
1181 
1182 		if (!allocate_buffers(server))
1183 			continue;
1184 
1185 		server->large_buf = false;
1186 		buf = server->smallbuf;
1187 		pdu_length = 4; /* enough to get RFC1001 header */
1188 
1189 		length = cifs_read_from_socket(server, buf, pdu_length);
1190 		if (length < 0)
1191 			continue;
1192 
1193 		if (is_smb1(server))
1194 			server->total_read = length;
1195 		else
1196 			server->total_read = 0;
1197 
1198 		/*
1199 		 * The right amount was read from socket - 4 bytes,
1200 		 * so we can now interpret the length field.
1201 		 */
1202 		pdu_length = get_rfc1002_length(buf);
1203 
1204 		cifs_dbg(FYI, "RFC1002 header 0x%x\n", pdu_length);
1205 		if (!is_smb_response(server, buf[0]))
1206 			continue;
1207 
1208 		pending_reconnect = false;
1209 next_pdu:
1210 		server->pdu_size = pdu_length;
1211 
1212 		/* make sure we have enough to get to the MID */
1213 		if (server->pdu_size < MID_HEADER_SIZE(server)) {
1214 			cifs_server_dbg(VFS, "SMB response too short (%u bytes)\n",
1215 				 server->pdu_size);
1216 			cifs_reconnect(server, true);
1217 			continue;
1218 		}
1219 
1220 		/* read down to the MID */
1221 		length = cifs_read_from_socket(server,
1222 			     buf + HEADER_PREAMBLE_SIZE(server),
1223 			     MID_HEADER_SIZE(server));
1224 		if (length < 0)
1225 			continue;
1226 		server->total_read += length;
1227 
1228 		if (server->ops->next_header) {
1229 			if (server->ops->next_header(server, buf, &next_offset)) {
1230 				cifs_dbg(VFS, "%s: malformed response (next_offset=%u)\n",
1231 					 __func__, next_offset);
1232 				cifs_reconnect(server, true);
1233 				continue;
1234 			}
1235 			if (next_offset)
1236 				server->pdu_size = next_offset;
1237 		}
1238 
1239 		memset(mids, 0, sizeof(mids));
1240 		memset(bufs, 0, sizeof(bufs));
1241 		num_mids = 0;
1242 
1243 		if (server->ops->is_transform_hdr &&
1244 		    server->ops->receive_transform &&
1245 		    server->ops->is_transform_hdr(buf)) {
1246 			length = server->ops->receive_transform(server,
1247 								mids,
1248 								bufs,
1249 								&num_mids);
1250 		} else {
1251 			mids[0] = server->ops->find_mid(server, buf);
1252 			bufs[0] = buf;
1253 			num_mids = 1;
1254 
1255 			if (!mids[0] || !mids[0]->receive)
1256 				length = standard_receive3(server, mids[0]);
1257 			else
1258 				length = mids[0]->receive(server, mids[0]);
1259 		}
1260 
1261 		if (length < 0) {
1262 			for (i = 0; i < num_mids; i++)
1263 				if (mids[i])
1264 					release_mid(mids[i]);
1265 			continue;
1266 		}
1267 
1268 		if (server->ops->is_status_io_timeout &&
1269 		    server->ops->is_status_io_timeout(buf)) {
1270 			num_io_timeout++;
1271 			if (num_io_timeout > MAX_STATUS_IO_TIMEOUT) {
1272 				cifs_server_dbg(VFS,
1273 						"Number of request timeouts exceeded %d. Reconnecting",
1274 						MAX_STATUS_IO_TIMEOUT);
1275 
1276 				pending_reconnect = true;
1277 				num_io_timeout = 0;
1278 			}
1279 		}
1280 
1281 		server->lstrp = jiffies;
1282 
1283 		for (i = 0; i < num_mids; i++) {
1284 			if (mids[i] != NULL) {
1285 				mids[i]->resp_buf_size = server->pdu_size;
1286 
1287 				if (bufs[i] != NULL) {
1288 					if (server->ops->is_network_name_deleted &&
1289 					    server->ops->is_network_name_deleted(bufs[i],
1290 										 server)) {
1291 						cifs_server_dbg(FYI,
1292 								"Share deleted. Reconnect needed");
1293 					}
1294 				}
1295 
1296 				if (!mids[i]->multiRsp || mids[i]->multiEnd)
1297 					mids[i]->callback(mids[i]);
1298 
1299 				release_mid(mids[i]);
1300 			} else if (server->ops->is_oplock_break &&
1301 				   server->ops->is_oplock_break(bufs[i],
1302 								server)) {
1303 				smb2_add_credits_from_hdr(bufs[i], server);
1304 				cifs_dbg(FYI, "Received oplock break\n");
1305 			} else {
1306 				cifs_server_dbg(VFS, "No task to wake, unknown frame received! NumMids %d\n",
1307 						atomic_read(&mid_count));
1308 				cifs_dump_mem("Received Data is: ", bufs[i],
1309 					      HEADER_SIZE(server));
1310 				smb2_add_credits_from_hdr(bufs[i], server);
1311 #ifdef CONFIG_CIFS_DEBUG2
1312 				if (server->ops->dump_detail)
1313 					server->ops->dump_detail(bufs[i],
1314 								 server);
1315 				cifs_dump_mids(server);
1316 #endif /* CIFS_DEBUG2 */
1317 			}
1318 		}
1319 
1320 		if (pdu_length > server->pdu_size) {
1321 			if (!allocate_buffers(server))
1322 				continue;
1323 			pdu_length -= server->pdu_size;
1324 			server->total_read = 0;
1325 			server->large_buf = false;
1326 			buf = server->smallbuf;
1327 			goto next_pdu;
1328 		}
1329 
1330 		/* do this reconnect at the very end after processing all MIDs */
1331 		if (pending_reconnect)
1332 			cifs_reconnect(server, true);
1333 
1334 	} /* end while !EXITING */
1335 
1336 	/* buffer usually freed in free_mid - need to free it here on exit */
1337 	cifs_buf_release(server->bigbuf);
1338 	if (server->smallbuf) /* no sense logging a debug message if NULL */
1339 		cifs_small_buf_release(server->smallbuf);
1340 
1341 	task_to_wake = xchg(&server->tsk, NULL);
1342 	clean_demultiplex_info(server);
1343 
1344 	/* if server->tsk was NULL then wait for a signal before exiting */
1345 	if (!task_to_wake) {
1346 		set_current_state(TASK_INTERRUPTIBLE);
1347 		while (!signal_pending(current)) {
1348 			schedule();
1349 			set_current_state(TASK_INTERRUPTIBLE);
1350 		}
1351 		set_current_state(TASK_RUNNING);
1352 	}
1353 
1354 	memalloc_noreclaim_restore(noreclaim_flag);
1355 	module_put_and_kthread_exit(0);
1356 }
1357 
1358 int
cifs_ipaddr_cmp(struct sockaddr * srcaddr,struct sockaddr * rhs)1359 cifs_ipaddr_cmp(struct sockaddr *srcaddr, struct sockaddr *rhs)
1360 {
1361 	struct sockaddr_in *saddr4 = (struct sockaddr_in *)srcaddr;
1362 	struct sockaddr_in *vaddr4 = (struct sockaddr_in *)rhs;
1363 	struct sockaddr_in6 *saddr6 = (struct sockaddr_in6 *)srcaddr;
1364 	struct sockaddr_in6 *vaddr6 = (struct sockaddr_in6 *)rhs;
1365 
1366 	switch (srcaddr->sa_family) {
1367 	case AF_UNSPEC:
1368 		switch (rhs->sa_family) {
1369 		case AF_UNSPEC:
1370 			return 0;
1371 		case AF_INET:
1372 		case AF_INET6:
1373 			return 1;
1374 		default:
1375 			return -1;
1376 		}
1377 	case AF_INET: {
1378 		switch (rhs->sa_family) {
1379 		case AF_UNSPEC:
1380 			return -1;
1381 		case AF_INET:
1382 			return memcmp(saddr4, vaddr4,
1383 				      sizeof(struct sockaddr_in));
1384 		case AF_INET6:
1385 			return 1;
1386 		default:
1387 			return -1;
1388 		}
1389 	}
1390 	case AF_INET6: {
1391 		switch (rhs->sa_family) {
1392 		case AF_UNSPEC:
1393 		case AF_INET:
1394 			return -1;
1395 		case AF_INET6:
1396 			return memcmp(saddr6,
1397 				      vaddr6,
1398 				      sizeof(struct sockaddr_in6));
1399 		default:
1400 			return -1;
1401 		}
1402 	}
1403 	default:
1404 		return -1; /* don't expect to be here */
1405 	}
1406 }
1407 
1408 /*
1409  * Returns true if srcaddr isn't specified and rhs isn't specified, or
1410  * if srcaddr is specified and matches the IP address of the rhs argument
1411  */
1412 bool
cifs_match_ipaddr(struct sockaddr * srcaddr,struct sockaddr * rhs)1413 cifs_match_ipaddr(struct sockaddr *srcaddr, struct sockaddr *rhs)
1414 {
1415 	switch (srcaddr->sa_family) {
1416 	case AF_UNSPEC:
1417 		return (rhs->sa_family == AF_UNSPEC);
1418 	case AF_INET: {
1419 		struct sockaddr_in *saddr4 = (struct sockaddr_in *)srcaddr;
1420 		struct sockaddr_in *vaddr4 = (struct sockaddr_in *)rhs;
1421 
1422 		return (saddr4->sin_addr.s_addr == vaddr4->sin_addr.s_addr);
1423 	}
1424 	case AF_INET6: {
1425 		struct sockaddr_in6 *saddr6 = (struct sockaddr_in6 *)srcaddr;
1426 		struct sockaddr_in6 *vaddr6 = (struct sockaddr_in6 *)rhs;
1427 
1428 		return (ipv6_addr_equal(&saddr6->sin6_addr, &vaddr6->sin6_addr)
1429 			&& saddr6->sin6_scope_id == vaddr6->sin6_scope_id);
1430 	}
1431 	default:
1432 		WARN_ON(1);
1433 		return false; /* don't expect to be here */
1434 	}
1435 }
1436 
1437 /*
1438  * If no port is specified in addr structure, we try to match with 445 port
1439  * and if it fails - with 139 ports. It should be called only if address
1440  * families of server and addr are equal.
1441  */
1442 static bool
match_port(struct TCP_Server_Info * server,struct sockaddr * addr)1443 match_port(struct TCP_Server_Info *server, struct sockaddr *addr)
1444 {
1445 	__be16 port, *sport;
1446 
1447 	/* SMBDirect manages its own ports, don't match it here */
1448 	if (server->rdma)
1449 		return true;
1450 
1451 	switch (addr->sa_family) {
1452 	case AF_INET:
1453 		sport = &((struct sockaddr_in *) &server->dstaddr)->sin_port;
1454 		port = ((struct sockaddr_in *) addr)->sin_port;
1455 		break;
1456 	case AF_INET6:
1457 		sport = &((struct sockaddr_in6 *) &server->dstaddr)->sin6_port;
1458 		port = ((struct sockaddr_in6 *) addr)->sin6_port;
1459 		break;
1460 	default:
1461 		WARN_ON(1);
1462 		return false;
1463 	}
1464 
1465 	if (!port) {
1466 		port = htons(CIFS_PORT);
1467 		if (port == *sport)
1468 			return true;
1469 
1470 		port = htons(RFC1001_PORT);
1471 	}
1472 
1473 	return port == *sport;
1474 }
1475 
match_server_address(struct TCP_Server_Info * server,struct sockaddr * addr)1476 static bool match_server_address(struct TCP_Server_Info *server, struct sockaddr *addr)
1477 {
1478 	if (!cifs_match_ipaddr(addr, (struct sockaddr *)&server->dstaddr))
1479 		return false;
1480 
1481 	return true;
1482 }
1483 
1484 static bool
match_security(struct TCP_Server_Info * server,struct smb3_fs_context * ctx)1485 match_security(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
1486 {
1487 	/*
1488 	 * The select_sectype function should either return the ctx->sectype
1489 	 * that was specified, or "Unspecified" if that sectype was not
1490 	 * compatible with the given NEGOTIATE request.
1491 	 */
1492 	if (server->ops->select_sectype(server, ctx->sectype)
1493 	     == Unspecified)
1494 		return false;
1495 
1496 	/*
1497 	 * Now check if signing mode is acceptable. No need to check
1498 	 * global_secflags at this point since if MUST_SIGN is set then
1499 	 * the server->sign had better be too.
1500 	 */
1501 	if (ctx->sign && !server->sign)
1502 		return false;
1503 
1504 	return true;
1505 }
1506 
1507 /* this function must be called with srv_lock held */
match_server(struct TCP_Server_Info * server,struct smb3_fs_context * ctx,bool match_super)1508 static int match_server(struct TCP_Server_Info *server,
1509 			struct smb3_fs_context *ctx,
1510 			bool match_super)
1511 {
1512 	struct sockaddr *addr = (struct sockaddr *)&ctx->dstaddr;
1513 
1514 	lockdep_assert_held(&server->srv_lock);
1515 
1516 	if (ctx->nosharesock)
1517 		return 0;
1518 
1519 	/* this server does not share socket */
1520 	if (server->nosharesock)
1521 		return 0;
1522 
1523 	if (!match_super && (ctx->dfs_conn || server->dfs_conn))
1524 		return 0;
1525 
1526 	/* If multidialect negotiation see if existing sessions match one */
1527 	if (strcmp(ctx->vals->version_string, SMB3ANY_VERSION_STRING) == 0) {
1528 		if (server->vals->protocol_id < SMB30_PROT_ID)
1529 			return 0;
1530 	} else if (strcmp(ctx->vals->version_string,
1531 		   SMBDEFAULT_VERSION_STRING) == 0) {
1532 		if (server->vals->protocol_id < SMB21_PROT_ID)
1533 			return 0;
1534 	} else if ((server->vals != ctx->vals) || (server->ops != ctx->ops))
1535 		return 0;
1536 
1537 	if (!net_eq(cifs_net_ns(server), current->nsproxy->net_ns))
1538 		return 0;
1539 
1540 	if (!cifs_match_ipaddr((struct sockaddr *)&ctx->srcaddr,
1541 			       (struct sockaddr *)&server->srcaddr))
1542 		return 0;
1543 	/*
1544 	 * When matching cifs.ko superblocks (@match_super == true), we can't
1545 	 * really match either @server->leaf_fullpath or @server->dstaddr
1546 	 * directly since this @server might belong to a completely different
1547 	 * server -- in case of domain-based DFS referrals or DFS links -- as
1548 	 * provided earlier by mount(2) through 'source' and 'ip' options.
1549 	 *
1550 	 * Otherwise, match the DFS referral in @server->leaf_fullpath or the
1551 	 * destination address in @server->dstaddr.
1552 	 *
1553 	 * When using 'nodfs' mount option, we avoid sharing it with DFS
1554 	 * connections as they might failover.
1555 	 */
1556 	if (!match_super) {
1557 		if (!ctx->nodfs) {
1558 			if (server->leaf_fullpath) {
1559 				if (!ctx->leaf_fullpath ||
1560 				    strcasecmp(server->leaf_fullpath,
1561 					       ctx->leaf_fullpath))
1562 					return 0;
1563 			} else if (ctx->leaf_fullpath) {
1564 				return 0;
1565 			}
1566 		} else if (server->leaf_fullpath) {
1567 			return 0;
1568 		}
1569 	}
1570 
1571 	/*
1572 	 * Match for a regular connection (address/hostname/port) which has no
1573 	 * DFS referrals set.
1574 	 */
1575 	if (!server->leaf_fullpath &&
1576 	    (strcasecmp(server->hostname, ctx->server_hostname) ||
1577 	     !match_server_address(server, addr) ||
1578 	     !match_port(server, addr)))
1579 		return 0;
1580 
1581 	if (!match_security(server, ctx))
1582 		return 0;
1583 
1584 	if (server->echo_interval != ctx->echo_interval * HZ)
1585 		return 0;
1586 
1587 	if (server->rdma != ctx->rdma)
1588 		return 0;
1589 
1590 	if (server->ignore_signature != ctx->ignore_signature)
1591 		return 0;
1592 
1593 	if (server->min_offload != ctx->min_offload)
1594 		return 0;
1595 
1596 	if (server->retrans != ctx->retrans)
1597 		return 0;
1598 
1599 	return 1;
1600 }
1601 
1602 struct TCP_Server_Info *
cifs_find_tcp_session(struct smb3_fs_context * ctx)1603 cifs_find_tcp_session(struct smb3_fs_context *ctx)
1604 {
1605 	struct TCP_Server_Info *server;
1606 
1607 	spin_lock(&cifs_tcp_ses_lock);
1608 	list_for_each_entry(server, &cifs_tcp_ses_list, tcp_ses_list) {
1609 		spin_lock(&server->srv_lock);
1610 		/*
1611 		 * Skip ses channels since they're only handled in lower layers
1612 		 * (e.g. cifs_send_recv).
1613 		 */
1614 		if (SERVER_IS_CHAN(server) ||
1615 		    !match_server(server, ctx, false)) {
1616 			spin_unlock(&server->srv_lock);
1617 			continue;
1618 		}
1619 		spin_unlock(&server->srv_lock);
1620 
1621 		++server->srv_count;
1622 		spin_unlock(&cifs_tcp_ses_lock);
1623 		cifs_dbg(FYI, "Existing tcp session with server found\n");
1624 		return server;
1625 	}
1626 	spin_unlock(&cifs_tcp_ses_lock);
1627 	return NULL;
1628 }
1629 
1630 void
cifs_put_tcp_session(struct TCP_Server_Info * server,int from_reconnect)1631 cifs_put_tcp_session(struct TCP_Server_Info *server, int from_reconnect)
1632 {
1633 	struct task_struct *task;
1634 
1635 	spin_lock(&cifs_tcp_ses_lock);
1636 	if (--server->srv_count > 0) {
1637 		spin_unlock(&cifs_tcp_ses_lock);
1638 		return;
1639 	}
1640 
1641 	/* srv_count can never go negative */
1642 	WARN_ON(server->srv_count < 0);
1643 
1644 	list_del_init(&server->tcp_ses_list);
1645 	spin_unlock(&cifs_tcp_ses_lock);
1646 
1647 	cancel_delayed_work_sync(&server->echo);
1648 
1649 	if (from_reconnect)
1650 		/*
1651 		 * Avoid deadlock here: reconnect work calls
1652 		 * cifs_put_tcp_session() at its end. Need to be sure
1653 		 * that reconnect work does nothing with server pointer after
1654 		 * that step.
1655 		 */
1656 		cancel_delayed_work(&server->reconnect);
1657 	else
1658 		cancel_delayed_work_sync(&server->reconnect);
1659 
1660 	/* For secondary channels, we pick up ref-count on the primary server */
1661 	if (SERVER_IS_CHAN(server))
1662 		cifs_put_tcp_session(server->primary_server, from_reconnect);
1663 
1664 	spin_lock(&server->srv_lock);
1665 	server->tcpStatus = CifsExiting;
1666 	spin_unlock(&server->srv_lock);
1667 
1668 	cifs_crypto_secmech_release(server);
1669 
1670 	kfree_sensitive(server->session_key.response);
1671 	server->session_key.response = NULL;
1672 	server->session_key.len = 0;
1673 	kfree(server->hostname);
1674 	server->hostname = NULL;
1675 
1676 	task = xchg(&server->tsk, NULL);
1677 	if (task)
1678 		send_sig(SIGKILL, task, 1);
1679 }
1680 
1681 struct TCP_Server_Info *
cifs_get_tcp_session(struct smb3_fs_context * ctx,struct TCP_Server_Info * primary_server)1682 cifs_get_tcp_session(struct smb3_fs_context *ctx,
1683 		     struct TCP_Server_Info *primary_server)
1684 {
1685 	struct TCP_Server_Info *tcp_ses = NULL;
1686 	int rc;
1687 
1688 	cifs_dbg(FYI, "UNC: %s\n", ctx->UNC);
1689 
1690 	/* see if we already have a matching tcp_ses */
1691 	tcp_ses = cifs_find_tcp_session(ctx);
1692 	if (tcp_ses)
1693 		return tcp_ses;
1694 
1695 	tcp_ses = kzalloc(sizeof(struct TCP_Server_Info), GFP_KERNEL);
1696 	if (!tcp_ses) {
1697 		rc = -ENOMEM;
1698 		goto out_err;
1699 	}
1700 
1701 	tcp_ses->hostname = kstrdup(ctx->server_hostname, GFP_KERNEL);
1702 	if (!tcp_ses->hostname) {
1703 		rc = -ENOMEM;
1704 		goto out_err;
1705 	}
1706 
1707 	if (ctx->leaf_fullpath) {
1708 		tcp_ses->leaf_fullpath = kstrdup(ctx->leaf_fullpath, GFP_KERNEL);
1709 		if (!tcp_ses->leaf_fullpath) {
1710 			rc = -ENOMEM;
1711 			goto out_err;
1712 		}
1713 	}
1714 
1715 	if (ctx->nosharesock)
1716 		tcp_ses->nosharesock = true;
1717 	tcp_ses->dfs_conn = ctx->dfs_conn;
1718 
1719 	tcp_ses->ops = ctx->ops;
1720 	tcp_ses->vals = ctx->vals;
1721 
1722 	/* Grab netns reference for this server. */
1723 	cifs_set_net_ns(tcp_ses, get_net(current->nsproxy->net_ns));
1724 
1725 	tcp_ses->conn_id = atomic_inc_return(&tcpSesNextId);
1726 	tcp_ses->noblockcnt = ctx->rootfs;
1727 	tcp_ses->noblocksnd = ctx->noblocksnd || ctx->rootfs;
1728 	tcp_ses->noautotune = ctx->noautotune;
1729 	tcp_ses->tcp_nodelay = ctx->sockopt_tcp_nodelay;
1730 	tcp_ses->rdma = ctx->rdma;
1731 	tcp_ses->in_flight = 0;
1732 	tcp_ses->max_in_flight = 0;
1733 	tcp_ses->credits = 1;
1734 	if (primary_server) {
1735 		spin_lock(&cifs_tcp_ses_lock);
1736 		++primary_server->srv_count;
1737 		spin_unlock(&cifs_tcp_ses_lock);
1738 		tcp_ses->primary_server = primary_server;
1739 	}
1740 	init_waitqueue_head(&tcp_ses->response_q);
1741 	init_waitqueue_head(&tcp_ses->request_q);
1742 	INIT_LIST_HEAD(&tcp_ses->pending_mid_q);
1743 	mutex_init(&tcp_ses->_srv_mutex);
1744 	memcpy(tcp_ses->workstation_RFC1001_name,
1745 		ctx->source_rfc1001_name, RFC1001_NAME_LEN_WITH_NULL);
1746 	memcpy(tcp_ses->server_RFC1001_name,
1747 		ctx->target_rfc1001_name, RFC1001_NAME_LEN_WITH_NULL);
1748 	tcp_ses->session_estab = false;
1749 	tcp_ses->sequence_number = 0;
1750 	tcp_ses->channel_sequence_num = 0; /* only tracked for primary channel */
1751 	tcp_ses->reconnect_instance = 1;
1752 	tcp_ses->lstrp = jiffies;
1753 	tcp_ses->compression.requested = ctx->compress;
1754 	spin_lock_init(&tcp_ses->req_lock);
1755 	spin_lock_init(&tcp_ses->srv_lock);
1756 	spin_lock_init(&tcp_ses->mid_lock);
1757 	INIT_LIST_HEAD(&tcp_ses->tcp_ses_list);
1758 	INIT_LIST_HEAD(&tcp_ses->smb_ses_list);
1759 	INIT_DELAYED_WORK(&tcp_ses->echo, cifs_echo_request);
1760 	INIT_DELAYED_WORK(&tcp_ses->reconnect, smb2_reconnect_server);
1761 	mutex_init(&tcp_ses->reconnect_mutex);
1762 #ifdef CONFIG_CIFS_DFS_UPCALL
1763 	mutex_init(&tcp_ses->refpath_lock);
1764 #endif
1765 	memcpy(&tcp_ses->srcaddr, &ctx->srcaddr,
1766 	       sizeof(tcp_ses->srcaddr));
1767 	memcpy(&tcp_ses->dstaddr, &ctx->dstaddr,
1768 		sizeof(tcp_ses->dstaddr));
1769 	if (ctx->use_client_guid)
1770 		memcpy(tcp_ses->client_guid, ctx->client_guid,
1771 		       SMB2_CLIENT_GUID_SIZE);
1772 	else
1773 		generate_random_uuid(tcp_ses->client_guid);
1774 	/*
1775 	 * at this point we are the only ones with the pointer
1776 	 * to the struct since the kernel thread not created yet
1777 	 * no need to spinlock this init of tcpStatus or srv_count
1778 	 */
1779 	tcp_ses->tcpStatus = CifsNew;
1780 	++tcp_ses->srv_count;
1781 
1782 	if (ctx->echo_interval >= SMB_ECHO_INTERVAL_MIN &&
1783 		ctx->echo_interval <= SMB_ECHO_INTERVAL_MAX)
1784 		tcp_ses->echo_interval = ctx->echo_interval * HZ;
1785 	else
1786 		tcp_ses->echo_interval = SMB_ECHO_INTERVAL_DEFAULT * HZ;
1787 	if (tcp_ses->rdma) {
1788 #ifndef CONFIG_CIFS_SMB_DIRECT
1789 		cifs_dbg(VFS, "CONFIG_CIFS_SMB_DIRECT is not enabled\n");
1790 		rc = -ENOENT;
1791 		goto out_err_crypto_release;
1792 #endif
1793 		tcp_ses->smbd_conn = smbd_get_connection(
1794 			tcp_ses, (struct sockaddr *)&ctx->dstaddr);
1795 		if (tcp_ses->smbd_conn) {
1796 			cifs_dbg(VFS, "RDMA transport established\n");
1797 			rc = 0;
1798 			goto smbd_connected;
1799 		} else {
1800 			rc = -ENOENT;
1801 			goto out_err_crypto_release;
1802 		}
1803 	}
1804 	rc = ip_connect(tcp_ses);
1805 	if (rc < 0) {
1806 		cifs_dbg(VFS, "Error connecting to socket. Aborting operation.\n");
1807 		goto out_err_crypto_release;
1808 	}
1809 smbd_connected:
1810 	/*
1811 	 * since we're in a cifs function already, we know that
1812 	 * this will succeed. No need for try_module_get().
1813 	 */
1814 	__module_get(THIS_MODULE);
1815 	tcp_ses->tsk = kthread_run(cifs_demultiplex_thread,
1816 				  tcp_ses, "cifsd");
1817 	if (IS_ERR(tcp_ses->tsk)) {
1818 		rc = PTR_ERR(tcp_ses->tsk);
1819 		cifs_dbg(VFS, "error %d create cifsd thread\n", rc);
1820 		module_put(THIS_MODULE);
1821 		goto out_err_crypto_release;
1822 	}
1823 	tcp_ses->min_offload = ctx->min_offload;
1824 	tcp_ses->retrans = ctx->retrans;
1825 	/*
1826 	 * at this point we are the only ones with the pointer
1827 	 * to the struct since the kernel thread not created yet
1828 	 * no need to spinlock this update of tcpStatus
1829 	 */
1830 	spin_lock(&tcp_ses->srv_lock);
1831 	tcp_ses->tcpStatus = CifsNeedNegotiate;
1832 	spin_unlock(&tcp_ses->srv_lock);
1833 
1834 	if ((ctx->max_credits < 20) || (ctx->max_credits > 60000))
1835 		tcp_ses->max_credits = SMB2_MAX_CREDITS_AVAILABLE;
1836 	else
1837 		tcp_ses->max_credits = ctx->max_credits;
1838 
1839 	tcp_ses->nr_targets = 1;
1840 	tcp_ses->ignore_signature = ctx->ignore_signature;
1841 	/* thread spawned, put it on the list */
1842 	spin_lock(&cifs_tcp_ses_lock);
1843 	list_add(&tcp_ses->tcp_ses_list, &cifs_tcp_ses_list);
1844 	spin_unlock(&cifs_tcp_ses_lock);
1845 
1846 	/* queue echo request delayed work */
1847 	queue_delayed_work(cifsiod_wq, &tcp_ses->echo, tcp_ses->echo_interval);
1848 
1849 	return tcp_ses;
1850 
1851 out_err_crypto_release:
1852 	cifs_crypto_secmech_release(tcp_ses);
1853 
1854 	/* Release netns reference for this server. */
1855 	put_net(cifs_net_ns(tcp_ses));
1856 
1857 out_err:
1858 	if (tcp_ses) {
1859 		if (SERVER_IS_CHAN(tcp_ses))
1860 			cifs_put_tcp_session(tcp_ses->primary_server, false);
1861 		kfree(tcp_ses->hostname);
1862 		kfree(tcp_ses->leaf_fullpath);
1863 		if (tcp_ses->ssocket) {
1864 			sock_release(tcp_ses->ssocket);
1865 			put_net(cifs_net_ns(tcp_ses));
1866 		}
1867 		kfree(tcp_ses);
1868 	}
1869 	return ERR_PTR(rc);
1870 }
1871 
1872 /* 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)1873 static int match_session(struct cifs_ses *ses,
1874 			 struct smb3_fs_context *ctx,
1875 			 bool match_super)
1876 {
1877 	if (ctx->sectype != Unspecified &&
1878 	    ctx->sectype != ses->sectype)
1879 		return 0;
1880 
1881 	if (!match_super && ctx->dfs_root_ses != ses->dfs_root_ses)
1882 		return 0;
1883 
1884 	/*
1885 	 * If an existing session is limited to less channels than
1886 	 * requested, it should not be reused
1887 	 */
1888 	if (ses->chan_max < ctx->max_channels)
1889 		return 0;
1890 
1891 	switch (ses->sectype) {
1892 	case Kerberos:
1893 		if (!uid_eq(ctx->cred_uid, ses->cred_uid))
1894 			return 0;
1895 		break;
1896 	default:
1897 		/* NULL username means anonymous session */
1898 		if (ses->user_name == NULL) {
1899 			if (!ctx->nullauth)
1900 				return 0;
1901 			break;
1902 		}
1903 
1904 		/* anything else takes username/password */
1905 		if (strncmp(ses->user_name,
1906 			    ctx->username ? ctx->username : "",
1907 			    CIFS_MAX_USERNAME_LEN))
1908 			return 0;
1909 		if ((ctx->username && strlen(ctx->username) != 0) &&
1910 		    ses->password != NULL) {
1911 
1912 			/* New mount can only share sessions with an existing mount if:
1913 			 * 1. Both password and password2 match, or
1914 			 * 2. password2 of the old mount matches password of the new mount
1915 			 *    and password of the old mount matches password2 of the new
1916 			 *	  mount
1917 			 */
1918 			if (ses->password2 != NULL && ctx->password2 != NULL) {
1919 				if (!((strncmp(ses->password, ctx->password ?
1920 					ctx->password : "", CIFS_MAX_PASSWORD_LEN) == 0 &&
1921 					strncmp(ses->password2, ctx->password2,
1922 					CIFS_MAX_PASSWORD_LEN) == 0) ||
1923 					(strncmp(ses->password, ctx->password2,
1924 					CIFS_MAX_PASSWORD_LEN) == 0 &&
1925 					strncmp(ses->password2, ctx->password ?
1926 					ctx->password : "", CIFS_MAX_PASSWORD_LEN) == 0)))
1927 					return 0;
1928 
1929 			} else if ((ses->password2 == NULL && ctx->password2 != NULL) ||
1930 				(ses->password2 != NULL && ctx->password2 == NULL)) {
1931 				return 0;
1932 
1933 			} else {
1934 				if (strncmp(ses->password, ctx->password ?
1935 					ctx->password : "", CIFS_MAX_PASSWORD_LEN))
1936 					return 0;
1937 			}
1938 		}
1939 	}
1940 
1941 	if (strcmp(ctx->local_nls->charset, ses->local_nls->charset))
1942 		return 0;
1943 
1944 	return 1;
1945 }
1946 
1947 /**
1948  * cifs_setup_ipc - helper to setup the IPC tcon for the session
1949  * @ses: smb session to issue the request on
1950  * @ctx: the superblock configuration context to use for building the
1951  *       new tree connection for the IPC (interprocess communication RPC)
1952  *
1953  * A new IPC connection is made and stored in the session
1954  * tcon_ipc. The IPC tcon has the same lifetime as the session.
1955  */
1956 static int
cifs_setup_ipc(struct cifs_ses * ses,struct smb3_fs_context * ctx)1957 cifs_setup_ipc(struct cifs_ses *ses, struct smb3_fs_context *ctx)
1958 {
1959 	int rc = 0, xid;
1960 	struct cifs_tcon *tcon;
1961 	char unc[SERVER_NAME_LENGTH + sizeof("//x/IPC$")] = {0};
1962 	bool seal = false;
1963 	struct TCP_Server_Info *server = ses->server;
1964 
1965 	/*
1966 	 * If the mount request that resulted in the creation of the
1967 	 * session requires encryption, force IPC to be encrypted too.
1968 	 */
1969 	if (ctx->seal) {
1970 		if (server->capabilities & SMB2_GLOBAL_CAP_ENCRYPTION)
1971 			seal = true;
1972 		else {
1973 			cifs_server_dbg(VFS,
1974 				 "IPC: server doesn't support encryption\n");
1975 			return -EOPNOTSUPP;
1976 		}
1977 	}
1978 
1979 	/* no need to setup directory caching on IPC share, so pass in false */
1980 	tcon = tcon_info_alloc(false, netfs_trace_tcon_ref_new_ipc);
1981 	if (tcon == NULL)
1982 		return -ENOMEM;
1983 
1984 	spin_lock(&server->srv_lock);
1985 	scnprintf(unc, sizeof(unc), "\\\\%s\\IPC$", server->hostname);
1986 	spin_unlock(&server->srv_lock);
1987 
1988 	xid = get_xid();
1989 	tcon->ses = ses;
1990 	tcon->ipc = true;
1991 	tcon->seal = seal;
1992 	rc = server->ops->tree_connect(xid, ses, unc, tcon, ctx->local_nls);
1993 	free_xid(xid);
1994 
1995 	if (rc) {
1996 		cifs_server_dbg(VFS, "failed to connect to IPC (rc=%d)\n", rc);
1997 		tconInfoFree(tcon, netfs_trace_tcon_ref_free_ipc_fail);
1998 		goto out;
1999 	}
2000 
2001 	cifs_dbg(FYI, "IPC tcon rc=%d ipc tid=0x%x\n", rc, tcon->tid);
2002 
2003 	spin_lock(&tcon->tc_lock);
2004 	tcon->status = TID_GOOD;
2005 	spin_unlock(&tcon->tc_lock);
2006 	ses->tcon_ipc = tcon;
2007 out:
2008 	return rc;
2009 }
2010 
2011 static struct cifs_ses *
cifs_find_smb_ses(struct TCP_Server_Info * server,struct smb3_fs_context * ctx)2012 cifs_find_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
2013 {
2014 	struct cifs_ses *ses, *ret = NULL;
2015 
2016 	spin_lock(&cifs_tcp_ses_lock);
2017 	list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) {
2018 		spin_lock(&ses->ses_lock);
2019 		if (ses->ses_status == SES_EXITING) {
2020 			spin_unlock(&ses->ses_lock);
2021 			continue;
2022 		}
2023 		spin_lock(&ses->chan_lock);
2024 		if (match_session(ses, ctx, false)) {
2025 			spin_unlock(&ses->chan_lock);
2026 			spin_unlock(&ses->ses_lock);
2027 			ret = ses;
2028 			break;
2029 		}
2030 		spin_unlock(&ses->chan_lock);
2031 		spin_unlock(&ses->ses_lock);
2032 	}
2033 	if (ret)
2034 		cifs_smb_ses_inc_refcount(ret);
2035 	spin_unlock(&cifs_tcp_ses_lock);
2036 	return ret;
2037 }
2038 
__cifs_put_smb_ses(struct cifs_ses * ses)2039 void __cifs_put_smb_ses(struct cifs_ses *ses)
2040 {
2041 	struct TCP_Server_Info *server = ses->server;
2042 	struct cifs_tcon *tcon;
2043 	unsigned int xid;
2044 	size_t i;
2045 	bool do_logoff;
2046 	int rc;
2047 
2048 	spin_lock(&cifs_tcp_ses_lock);
2049 	spin_lock(&ses->ses_lock);
2050 	cifs_dbg(FYI, "%s: id=0x%llx ses_count=%d ses_status=%u ipc=%s\n",
2051 		 __func__, ses->Suid, ses->ses_count, ses->ses_status,
2052 		 ses->tcon_ipc ? ses->tcon_ipc->tree_name : "none");
2053 	if (ses->ses_status == SES_EXITING || --ses->ses_count > 0) {
2054 		spin_unlock(&ses->ses_lock);
2055 		spin_unlock(&cifs_tcp_ses_lock);
2056 		return;
2057 	}
2058 	/* ses_count can never go negative */
2059 	WARN_ON(ses->ses_count < 0);
2060 
2061 	spin_lock(&ses->chan_lock);
2062 	cifs_chan_clear_need_reconnect(ses, server);
2063 	spin_unlock(&ses->chan_lock);
2064 
2065 	do_logoff = ses->ses_status == SES_GOOD && server->ops->logoff;
2066 	ses->ses_status = SES_EXITING;
2067 	tcon = ses->tcon_ipc;
2068 	ses->tcon_ipc = NULL;
2069 	spin_unlock(&ses->ses_lock);
2070 	spin_unlock(&cifs_tcp_ses_lock);
2071 
2072 	/*
2073 	 * On session close, the IPC is closed and the server must release all
2074 	 * tcons of the session.  No need to send a tree disconnect here.
2075 	 *
2076 	 * Besides, it will make the server to not close durable and resilient
2077 	 * files on session close, as specified in MS-SMB2 3.3.5.6 Receiving an
2078 	 * SMB2 LOGOFF Request.
2079 	 */
2080 	tconInfoFree(tcon, netfs_trace_tcon_ref_free_ipc);
2081 	if (do_logoff) {
2082 		xid = get_xid();
2083 		rc = server->ops->logoff(xid, ses);
2084 		cifs_server_dbg(FYI, "%s: Session Logoff: rc=%d\n",
2085 				__func__, rc);
2086 		_free_xid(xid);
2087 	}
2088 
2089 	spin_lock(&cifs_tcp_ses_lock);
2090 	list_del_init(&ses->smb_ses_list);
2091 	spin_unlock(&cifs_tcp_ses_lock);
2092 
2093 	/* close any extra channels */
2094 	for (i = 1; i < ses->chan_count; i++) {
2095 		if (ses->chans[i].iface) {
2096 			kref_put(&ses->chans[i].iface->refcount, release_iface);
2097 			ses->chans[i].iface = NULL;
2098 		}
2099 		cifs_put_tcp_session(ses->chans[i].server, 0);
2100 		ses->chans[i].server = NULL;
2101 	}
2102 
2103 	/* we now account for primary channel in iface->refcount */
2104 	if (ses->chans[0].iface) {
2105 		kref_put(&ses->chans[0].iface->refcount, release_iface);
2106 		ses->chans[0].server = NULL;
2107 	}
2108 
2109 	sesInfoFree(ses);
2110 	cifs_put_tcp_session(server, 0);
2111 }
2112 
2113 #ifdef CONFIG_KEYS
2114 
2115 /* strlen("cifs:a:") + CIFS_MAX_DOMAINNAME_LEN + 1 */
2116 #define CIFSCREDS_DESC_SIZE (7 + CIFS_MAX_DOMAINNAME_LEN + 1)
2117 
2118 /* Populate username and pw fields from keyring if possible */
2119 static int
cifs_set_cifscreds(struct smb3_fs_context * ctx,struct cifs_ses * ses)2120 cifs_set_cifscreds(struct smb3_fs_context *ctx, struct cifs_ses *ses)
2121 {
2122 	int rc = 0;
2123 	int is_domain = 0;
2124 	const char *delim, *payload;
2125 	char *desc;
2126 	ssize_t len;
2127 	struct key *key;
2128 	struct TCP_Server_Info *server = ses->server;
2129 	struct sockaddr_in *sa;
2130 	struct sockaddr_in6 *sa6;
2131 	const struct user_key_payload *upayload;
2132 
2133 	desc = kmalloc(CIFSCREDS_DESC_SIZE, GFP_KERNEL);
2134 	if (!desc)
2135 		return -ENOMEM;
2136 
2137 	/* try to find an address key first */
2138 	switch (server->dstaddr.ss_family) {
2139 	case AF_INET:
2140 		sa = (struct sockaddr_in *)&server->dstaddr;
2141 		sprintf(desc, "cifs:a:%pI4", &sa->sin_addr.s_addr);
2142 		break;
2143 	case AF_INET6:
2144 		sa6 = (struct sockaddr_in6 *)&server->dstaddr;
2145 		sprintf(desc, "cifs:a:%pI6c", &sa6->sin6_addr.s6_addr);
2146 		break;
2147 	default:
2148 		cifs_dbg(FYI, "Bad ss_family (%hu)\n",
2149 			 server->dstaddr.ss_family);
2150 		rc = -EINVAL;
2151 		goto out_err;
2152 	}
2153 
2154 	cifs_dbg(FYI, "%s: desc=%s\n", __func__, desc);
2155 	key = request_key(&key_type_logon, desc, "");
2156 	if (IS_ERR(key)) {
2157 		if (!ses->domainName) {
2158 			cifs_dbg(FYI, "domainName is NULL\n");
2159 			rc = PTR_ERR(key);
2160 			goto out_err;
2161 		}
2162 
2163 		/* didn't work, try to find a domain key */
2164 		sprintf(desc, "cifs:d:%s", ses->domainName);
2165 		cifs_dbg(FYI, "%s: desc=%s\n", __func__, desc);
2166 		key = request_key(&key_type_logon, desc, "");
2167 		if (IS_ERR(key)) {
2168 			rc = PTR_ERR(key);
2169 			goto out_err;
2170 		}
2171 		is_domain = 1;
2172 	}
2173 
2174 	down_read(&key->sem);
2175 	upayload = user_key_payload_locked(key);
2176 	if (IS_ERR_OR_NULL(upayload)) {
2177 		rc = upayload ? PTR_ERR(upayload) : -EINVAL;
2178 		goto out_key_put;
2179 	}
2180 
2181 	/* find first : in payload */
2182 	payload = upayload->data;
2183 	delim = strnchr(payload, upayload->datalen, ':');
2184 	cifs_dbg(FYI, "payload=%s\n", payload);
2185 	if (!delim) {
2186 		cifs_dbg(FYI, "Unable to find ':' in payload (datalen=%d)\n",
2187 			 upayload->datalen);
2188 		rc = -EINVAL;
2189 		goto out_key_put;
2190 	}
2191 
2192 	len = delim - payload;
2193 	if (len > CIFS_MAX_USERNAME_LEN || len <= 0) {
2194 		cifs_dbg(FYI, "Bad value from username search (len=%zd)\n",
2195 			 len);
2196 		rc = -EINVAL;
2197 		goto out_key_put;
2198 	}
2199 
2200 	ctx->username = kstrndup(payload, len, GFP_KERNEL);
2201 	if (!ctx->username) {
2202 		cifs_dbg(FYI, "Unable to allocate %zd bytes for username\n",
2203 			 len);
2204 		rc = -ENOMEM;
2205 		goto out_key_put;
2206 	}
2207 	cifs_dbg(FYI, "%s: username=%s\n", __func__, ctx->username);
2208 
2209 	len = key->datalen - (len + 1);
2210 	if (len > CIFS_MAX_PASSWORD_LEN || len <= 0) {
2211 		cifs_dbg(FYI, "Bad len for password search (len=%zd)\n", len);
2212 		rc = -EINVAL;
2213 		kfree(ctx->username);
2214 		ctx->username = NULL;
2215 		goto out_key_put;
2216 	}
2217 
2218 	++delim;
2219 	/* BB consider adding support for password2 (Key Rotation) for multiuser in future */
2220 	ctx->password = kstrndup(delim, len, GFP_KERNEL);
2221 	if (!ctx->password) {
2222 		cifs_dbg(FYI, "Unable to allocate %zd bytes for password\n",
2223 			 len);
2224 		rc = -ENOMEM;
2225 		kfree(ctx->username);
2226 		ctx->username = NULL;
2227 		goto out_key_put;
2228 	}
2229 
2230 	/*
2231 	 * If we have a domain key then we must set the domainName in the
2232 	 * for the request.
2233 	 */
2234 	if (is_domain && ses->domainName) {
2235 		ctx->domainname = kstrdup(ses->domainName, GFP_KERNEL);
2236 		if (!ctx->domainname) {
2237 			cifs_dbg(FYI, "Unable to allocate %zd bytes for domain\n",
2238 				 len);
2239 			rc = -ENOMEM;
2240 			kfree(ctx->username);
2241 			ctx->username = NULL;
2242 			kfree_sensitive(ctx->password);
2243 			/* no need to free ctx->password2 since not allocated in this path */
2244 			ctx->password = NULL;
2245 			goto out_key_put;
2246 		}
2247 	}
2248 
2249 	strscpy(ctx->workstation_name, ses->workstation_name, sizeof(ctx->workstation_name));
2250 
2251 out_key_put:
2252 	up_read(&key->sem);
2253 	key_put(key);
2254 out_err:
2255 	kfree(desc);
2256 	cifs_dbg(FYI, "%s: returning %d\n", __func__, rc);
2257 	return rc;
2258 }
2259 #else /* ! CONFIG_KEYS */
2260 static inline int
cifs_set_cifscreds(struct smb3_fs_context * ctx,struct cifs_ses * ses)2261 cifs_set_cifscreds(struct smb3_fs_context *ctx __attribute__((unused)),
2262 		   struct cifs_ses *ses __attribute__((unused)))
2263 {
2264 	return -ENOSYS;
2265 }
2266 #endif /* CONFIG_KEYS */
2267 
2268 /**
2269  * cifs_get_smb_ses - get a session matching @ctx data from @server
2270  * @server: server to setup the session to
2271  * @ctx: superblock configuration context to use to setup the session
2272  *
2273  * This function assumes it is being called from cifs_mount() where we
2274  * already got a server reference (server refcount +1). See
2275  * cifs_get_tcon() for refcount explanations.
2276  */
2277 struct cifs_ses *
cifs_get_smb_ses(struct TCP_Server_Info * server,struct smb3_fs_context * ctx)2278 cifs_get_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
2279 {
2280 	int rc = 0;
2281 	int retries = 0;
2282 	unsigned int xid;
2283 	struct cifs_ses *ses;
2284 	struct sockaddr_in *addr = (struct sockaddr_in *)&server->dstaddr;
2285 	struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&server->dstaddr;
2286 
2287 	xid = get_xid();
2288 
2289 	ses = cifs_find_smb_ses(server, ctx);
2290 	if (ses) {
2291 		cifs_dbg(FYI, "Existing smb sess found (status=%d)\n",
2292 			 ses->ses_status);
2293 
2294 		spin_lock(&ses->chan_lock);
2295 		if (cifs_chan_needs_reconnect(ses, server)) {
2296 			spin_unlock(&ses->chan_lock);
2297 			cifs_dbg(FYI, "Session needs reconnect\n");
2298 
2299 			mutex_lock(&ses->session_mutex);
2300 
2301 retry_old_session:
2302 			rc = cifs_negotiate_protocol(xid, ses, server);
2303 			if (rc) {
2304 				mutex_unlock(&ses->session_mutex);
2305 				/* problem -- put our ses reference */
2306 				cifs_put_smb_ses(ses);
2307 				free_xid(xid);
2308 				return ERR_PTR(rc);
2309 			}
2310 
2311 			rc = cifs_setup_session(xid, ses, server,
2312 						ctx->local_nls);
2313 			if (rc) {
2314 				if (((rc == -EACCES) || (rc == -EKEYEXPIRED) ||
2315 					(rc == -EKEYREVOKED)) && !retries && ses->password2) {
2316 					retries++;
2317 					cifs_dbg(FYI, "Session reconnect failed, retrying with alternate password\n");
2318 					swap(ses->password, ses->password2);
2319 					goto retry_old_session;
2320 				}
2321 				mutex_unlock(&ses->session_mutex);
2322 				/* problem -- put our reference */
2323 				cifs_put_smb_ses(ses);
2324 				free_xid(xid);
2325 				return ERR_PTR(rc);
2326 			}
2327 			mutex_unlock(&ses->session_mutex);
2328 
2329 			spin_lock(&ses->chan_lock);
2330 		}
2331 		spin_unlock(&ses->chan_lock);
2332 
2333 		/* existing SMB ses has a server reference already */
2334 		cifs_put_tcp_session(server, 0);
2335 		free_xid(xid);
2336 		return ses;
2337 	}
2338 
2339 	rc = -ENOMEM;
2340 
2341 	cifs_dbg(FYI, "Existing smb sess not found\n");
2342 	ses = sesInfoAlloc();
2343 	if (ses == NULL)
2344 		goto get_ses_fail;
2345 
2346 	/* new SMB session uses our server ref */
2347 	ses->server = server;
2348 	if (server->dstaddr.ss_family == AF_INET6)
2349 		sprintf(ses->ip_addr, "%pI6", &addr6->sin6_addr);
2350 	else
2351 		sprintf(ses->ip_addr, "%pI4", &addr->sin_addr);
2352 
2353 	if (ctx->username) {
2354 		ses->user_name = kstrdup(ctx->username, GFP_KERNEL);
2355 		if (!ses->user_name)
2356 			goto get_ses_fail;
2357 	}
2358 
2359 	/* ctx->password freed at unmount */
2360 	if (ctx->password) {
2361 		ses->password = kstrdup(ctx->password, GFP_KERNEL);
2362 		if (!ses->password)
2363 			goto get_ses_fail;
2364 	}
2365 	/* ctx->password freed at unmount */
2366 	if (ctx->password2) {
2367 		ses->password2 = kstrdup(ctx->password2, GFP_KERNEL);
2368 		if (!ses->password2)
2369 			goto get_ses_fail;
2370 	}
2371 	if (ctx->domainname) {
2372 		ses->domainName = kstrdup(ctx->domainname, GFP_KERNEL);
2373 		if (!ses->domainName)
2374 			goto get_ses_fail;
2375 	}
2376 
2377 	strscpy(ses->workstation_name, ctx->workstation_name, sizeof(ses->workstation_name));
2378 
2379 	if (ctx->domainauto)
2380 		ses->domainAuto = ctx->domainauto;
2381 	ses->cred_uid = ctx->cred_uid;
2382 	ses->linux_uid = ctx->linux_uid;
2383 
2384 	ses->sectype = ctx->sectype;
2385 	ses->sign = ctx->sign;
2386 
2387 	/*
2388 	 *Explicitly marking upcall_target mount option for easier handling
2389 	 * by cifs_spnego.c and eventually cifs.upcall.c
2390 	 */
2391 
2392 	switch (ctx->upcall_target) {
2393 	case UPTARGET_UNSPECIFIED: /* default to app */
2394 	case UPTARGET_APP:
2395 		ses->upcall_target = UPTARGET_APP;
2396 		break;
2397 	case UPTARGET_MOUNT:
2398 		ses->upcall_target = UPTARGET_MOUNT;
2399 		break;
2400 	default:
2401 		// should never happen
2402 		ses->upcall_target = UPTARGET_APP;
2403 		break;
2404 	}
2405 
2406 	ses->local_nls = load_nls(ctx->local_nls->charset);
2407 
2408 	/* add server as first channel */
2409 	spin_lock(&ses->chan_lock);
2410 	ses->chans[0].server = server;
2411 	ses->chan_count = 1;
2412 	ses->chan_max = ctx->multichannel ? ctx->max_channels:1;
2413 	ses->chans_need_reconnect = 1;
2414 	spin_unlock(&ses->chan_lock);
2415 
2416 retry_new_session:
2417 	mutex_lock(&ses->session_mutex);
2418 	rc = cifs_negotiate_protocol(xid, ses, server);
2419 	if (!rc)
2420 		rc = cifs_setup_session(xid, ses, server, ctx->local_nls);
2421 	mutex_unlock(&ses->session_mutex);
2422 
2423 	/* each channel uses a different signing key */
2424 	spin_lock(&ses->chan_lock);
2425 	memcpy(ses->chans[0].signkey, ses->smb3signingkey,
2426 	       sizeof(ses->smb3signingkey));
2427 	spin_unlock(&ses->chan_lock);
2428 
2429 	if (rc) {
2430 		if (((rc == -EACCES) || (rc == -EKEYEXPIRED) ||
2431 			(rc == -EKEYREVOKED)) && !retries && ses->password2) {
2432 			retries++;
2433 			cifs_dbg(FYI, "Session setup failed, retrying with alternate password\n");
2434 			swap(ses->password, ses->password2);
2435 			goto retry_new_session;
2436 		} else
2437 			goto get_ses_fail;
2438 	}
2439 
2440 	/*
2441 	 * success, put it on the list and add it as first channel
2442 	 * note: the session becomes active soon after this. So you'll
2443 	 * need to lock before changing something in the session.
2444 	 */
2445 	spin_lock(&cifs_tcp_ses_lock);
2446 	ses->dfs_root_ses = ctx->dfs_root_ses;
2447 	list_add(&ses->smb_ses_list, &server->smb_ses_list);
2448 	spin_unlock(&cifs_tcp_ses_lock);
2449 
2450 	cifs_setup_ipc(ses, ctx);
2451 
2452 	free_xid(xid);
2453 
2454 	return ses;
2455 
2456 get_ses_fail:
2457 	sesInfoFree(ses);
2458 	free_xid(xid);
2459 	return ERR_PTR(rc);
2460 }
2461 
2462 /* this function must be called with tc_lock held */
match_tcon(struct cifs_tcon * tcon,struct smb3_fs_context * ctx)2463 static int match_tcon(struct cifs_tcon *tcon, struct smb3_fs_context *ctx)
2464 {
2465 	struct TCP_Server_Info *server = tcon->ses->server;
2466 
2467 	if (tcon->status == TID_EXITING)
2468 		return 0;
2469 
2470 	if (tcon->origin_fullpath) {
2471 		if (!ctx->source ||
2472 		    !dfs_src_pathname_equal(ctx->source,
2473 					    tcon->origin_fullpath))
2474 			return 0;
2475 	} else if (!server->leaf_fullpath &&
2476 		   strncmp(tcon->tree_name, ctx->UNC, MAX_TREE_SIZE)) {
2477 		return 0;
2478 	}
2479 	if (tcon->seal != ctx->seal)
2480 		return 0;
2481 	if (tcon->snapshot_time != ctx->snapshot_time)
2482 		return 0;
2483 	if (tcon->handle_timeout != ctx->handle_timeout)
2484 		return 0;
2485 	if (tcon->no_lease != ctx->no_lease)
2486 		return 0;
2487 	if (tcon->nodelete != ctx->nodelete)
2488 		return 0;
2489 	return 1;
2490 }
2491 
2492 static struct cifs_tcon *
cifs_find_tcon(struct cifs_ses * ses,struct smb3_fs_context * ctx)2493 cifs_find_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx)
2494 {
2495 	struct cifs_tcon *tcon;
2496 
2497 	spin_lock(&cifs_tcp_ses_lock);
2498 	list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
2499 		spin_lock(&tcon->tc_lock);
2500 		if (!match_tcon(tcon, ctx)) {
2501 			spin_unlock(&tcon->tc_lock);
2502 			continue;
2503 		}
2504 		++tcon->tc_count;
2505 		trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count,
2506 				    netfs_trace_tcon_ref_get_find);
2507 		spin_unlock(&tcon->tc_lock);
2508 		spin_unlock(&cifs_tcp_ses_lock);
2509 		return tcon;
2510 	}
2511 	spin_unlock(&cifs_tcp_ses_lock);
2512 	return NULL;
2513 }
2514 
2515 void
cifs_put_tcon(struct cifs_tcon * tcon,enum smb3_tcon_ref_trace trace)2516 cifs_put_tcon(struct cifs_tcon *tcon, enum smb3_tcon_ref_trace trace)
2517 {
2518 	unsigned int xid;
2519 	struct cifs_ses *ses;
2520 	LIST_HEAD(ses_list);
2521 
2522 	/*
2523 	 * IPC tcon share the lifetime of their session and are
2524 	 * destroyed in the session put function
2525 	 */
2526 	if (tcon == NULL || tcon->ipc)
2527 		return;
2528 
2529 	ses = tcon->ses;
2530 	cifs_dbg(FYI, "%s: tc_count=%d\n", __func__, tcon->tc_count);
2531 	spin_lock(&cifs_tcp_ses_lock);
2532 	spin_lock(&tcon->tc_lock);
2533 	trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count - 1, trace);
2534 	if (--tcon->tc_count > 0) {
2535 		spin_unlock(&tcon->tc_lock);
2536 		spin_unlock(&cifs_tcp_ses_lock);
2537 		return;
2538 	}
2539 
2540 	/* tc_count can never go negative */
2541 	WARN_ON(tcon->tc_count < 0);
2542 
2543 	list_del_init(&tcon->tcon_list);
2544 	tcon->status = TID_EXITING;
2545 	spin_unlock(&tcon->tc_lock);
2546 	spin_unlock(&cifs_tcp_ses_lock);
2547 
2548 	/* cancel polling of interfaces */
2549 	cancel_delayed_work_sync(&tcon->query_interfaces);
2550 #ifdef CONFIG_CIFS_DFS_UPCALL
2551 	cancel_delayed_work_sync(&tcon->dfs_cache_work);
2552 	list_replace_init(&tcon->dfs_ses_list, &ses_list);
2553 #endif
2554 
2555 	if (tcon->use_witness) {
2556 		int rc;
2557 
2558 		rc = cifs_swn_unregister(tcon);
2559 		if (rc < 0) {
2560 			cifs_dbg(VFS, "%s: Failed to unregister for witness notifications: %d\n",
2561 					__func__, rc);
2562 		}
2563 	}
2564 
2565 	xid = get_xid();
2566 	if (ses->server->ops->tree_disconnect)
2567 		ses->server->ops->tree_disconnect(xid, tcon);
2568 	_free_xid(xid);
2569 
2570 	cifs_fscache_release_super_cookie(tcon);
2571 	tconInfoFree(tcon, netfs_trace_tcon_ref_free);
2572 	cifs_put_smb_ses(ses);
2573 #ifdef CONFIG_CIFS_DFS_UPCALL
2574 	dfs_put_root_smb_sessions(&ses_list);
2575 #endif
2576 }
2577 
2578 /**
2579  * cifs_get_tcon - get a tcon matching @ctx data from @ses
2580  * @ses: smb session to issue the request on
2581  * @ctx: the superblock configuration context to use for building the
2582  *
2583  * - tcon refcount is the number of mount points using the tcon.
2584  * - ses refcount is the number of tcon using the session.
2585  *
2586  * 1. This function assumes it is being called from cifs_mount() where
2587  *    we already got a session reference (ses refcount +1).
2588  *
2589  * 2. Since we're in the context of adding a mount point, the end
2590  *    result should be either:
2591  *
2592  * a) a new tcon already allocated with refcount=1 (1 mount point) and
2593  *    its session refcount incremented (1 new tcon). This +1 was
2594  *    already done in (1).
2595  *
2596  * b) an existing tcon with refcount+1 (add a mount point to it) and
2597  *    identical ses refcount (no new tcon). Because of (1) we need to
2598  *    decrement the ses refcount.
2599  */
2600 static struct cifs_tcon *
cifs_get_tcon(struct cifs_ses * ses,struct smb3_fs_context * ctx)2601 cifs_get_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx)
2602 {
2603 	struct cifs_tcon *tcon;
2604 	bool nohandlecache;
2605 	int rc, xid;
2606 
2607 	tcon = cifs_find_tcon(ses, ctx);
2608 	if (tcon) {
2609 		/*
2610 		 * tcon has refcount already incremented but we need to
2611 		 * decrement extra ses reference gotten by caller (case b)
2612 		 */
2613 		cifs_dbg(FYI, "Found match on UNC path\n");
2614 		cifs_put_smb_ses(ses);
2615 		return tcon;
2616 	}
2617 
2618 	if (!ses->server->ops->tree_connect) {
2619 		rc = -ENOSYS;
2620 		goto out_fail;
2621 	}
2622 
2623 	if (ses->server->dialect >= SMB20_PROT_ID &&
2624 	    (ses->server->capabilities & SMB2_GLOBAL_CAP_DIRECTORY_LEASING))
2625 		nohandlecache = ctx->nohandlecache || !dir_cache_timeout;
2626 	else
2627 		nohandlecache = true;
2628 	tcon = tcon_info_alloc(!nohandlecache, netfs_trace_tcon_ref_new);
2629 	if (tcon == NULL) {
2630 		rc = -ENOMEM;
2631 		goto out_fail;
2632 	}
2633 	tcon->nohandlecache = nohandlecache;
2634 
2635 	if (ctx->snapshot_time) {
2636 		if (ses->server->vals->protocol_id == 0) {
2637 			cifs_dbg(VFS,
2638 			     "Use SMB2 or later for snapshot mount option\n");
2639 			rc = -EOPNOTSUPP;
2640 			goto out_fail;
2641 		} else
2642 			tcon->snapshot_time = ctx->snapshot_time;
2643 	}
2644 
2645 	if (ctx->handle_timeout) {
2646 		if (ses->server->vals->protocol_id == 0) {
2647 			cifs_dbg(VFS,
2648 			     "Use SMB2.1 or later for handle timeout option\n");
2649 			rc = -EOPNOTSUPP;
2650 			goto out_fail;
2651 		} else
2652 			tcon->handle_timeout = ctx->handle_timeout;
2653 	}
2654 
2655 	tcon->ses = ses;
2656 	if (ctx->password) {
2657 		tcon->password = kstrdup(ctx->password, GFP_KERNEL);
2658 		if (!tcon->password) {
2659 			rc = -ENOMEM;
2660 			goto out_fail;
2661 		}
2662 	}
2663 
2664 	if (ctx->seal) {
2665 		if (ses->server->vals->protocol_id == 0) {
2666 			cifs_dbg(VFS,
2667 				 "SMB3 or later required for encryption\n");
2668 			rc = -EOPNOTSUPP;
2669 			goto out_fail;
2670 		} else if (tcon->ses->server->capabilities &
2671 					SMB2_GLOBAL_CAP_ENCRYPTION)
2672 			tcon->seal = true;
2673 		else {
2674 			cifs_dbg(VFS, "Encryption is not supported on share\n");
2675 			rc = -EOPNOTSUPP;
2676 			goto out_fail;
2677 		}
2678 	}
2679 
2680 	if (ctx->linux_ext) {
2681 		if (ses->server->posix_ext_supported) {
2682 			tcon->posix_extensions = true;
2683 			pr_warn_once("SMB3.11 POSIX Extensions are experimental\n");
2684 		} else if ((ses->server->vals->protocol_id == SMB311_PROT_ID) ||
2685 		    (strcmp(ses->server->vals->version_string,
2686 		     SMB3ANY_VERSION_STRING) == 0) ||
2687 		    (strcmp(ses->server->vals->version_string,
2688 		     SMBDEFAULT_VERSION_STRING) == 0)) {
2689 			cifs_dbg(VFS, "Server does not support mounting with posix SMB3.11 extensions\n");
2690 			rc = -EOPNOTSUPP;
2691 			goto out_fail;
2692 		} else if (ses->server->vals->protocol_id == SMB10_PROT_ID)
2693 			if (cap_unix(ses))
2694 				cifs_dbg(FYI, "Unix Extensions requested on SMB1 mount\n");
2695 			else {
2696 				cifs_dbg(VFS, "SMB1 Unix Extensions not supported by server\n");
2697 				rc = -EOPNOTSUPP;
2698 				goto out_fail;
2699 		} else {
2700 			cifs_dbg(VFS,
2701 				"Check vers= mount option. SMB3.11 disabled but required for POSIX extensions\n");
2702 			rc = -EOPNOTSUPP;
2703 			goto out_fail;
2704 		}
2705 	}
2706 
2707 	xid = get_xid();
2708 	rc = ses->server->ops->tree_connect(xid, ses, ctx->UNC, tcon,
2709 					    ctx->local_nls);
2710 	free_xid(xid);
2711 	cifs_dbg(FYI, "Tcon rc = %d\n", rc);
2712 	if (rc)
2713 		goto out_fail;
2714 
2715 	tcon->use_persistent = false;
2716 	/* check if SMB2 or later, CIFS does not support persistent handles */
2717 	if (ctx->persistent) {
2718 		if (ses->server->vals->protocol_id == 0) {
2719 			cifs_dbg(VFS,
2720 			     "SMB3 or later required for persistent handles\n");
2721 			rc = -EOPNOTSUPP;
2722 			goto out_fail;
2723 		} else if (ses->server->capabilities &
2724 			   SMB2_GLOBAL_CAP_PERSISTENT_HANDLES)
2725 			tcon->use_persistent = true;
2726 		else /* persistent handles requested but not supported */ {
2727 			cifs_dbg(VFS,
2728 				"Persistent handles not supported on share\n");
2729 			rc = -EOPNOTSUPP;
2730 			goto out_fail;
2731 		}
2732 	} else if ((tcon->capabilities & SMB2_SHARE_CAP_CONTINUOUS_AVAILABILITY)
2733 	     && (ses->server->capabilities & SMB2_GLOBAL_CAP_PERSISTENT_HANDLES)
2734 	     && (ctx->nopersistent == false)) {
2735 		cifs_dbg(FYI, "enabling persistent handles\n");
2736 		tcon->use_persistent = true;
2737 	} else if (ctx->resilient) {
2738 		if (ses->server->vals->protocol_id == 0) {
2739 			cifs_dbg(VFS,
2740 			     "SMB2.1 or later required for resilient handles\n");
2741 			rc = -EOPNOTSUPP;
2742 			goto out_fail;
2743 		}
2744 		tcon->use_resilient = true;
2745 	}
2746 
2747 	tcon->use_witness = false;
2748 	if (IS_ENABLED(CONFIG_CIFS_SWN_UPCALL) && ctx->witness) {
2749 		if (ses->server->vals->protocol_id >= SMB30_PROT_ID) {
2750 			if (tcon->capabilities & SMB2_SHARE_CAP_CLUSTER) {
2751 				/*
2752 				 * Set witness in use flag in first place
2753 				 * to retry registration in the echo task
2754 				 */
2755 				tcon->use_witness = true;
2756 				/* And try to register immediately */
2757 				rc = cifs_swn_register(tcon);
2758 				if (rc < 0) {
2759 					cifs_dbg(VFS, "Failed to register for witness notifications: %d\n", rc);
2760 					goto out_fail;
2761 				}
2762 			} else {
2763 				/* TODO: try to extend for non-cluster uses (eg multichannel) */
2764 				cifs_dbg(VFS, "witness requested on mount but no CLUSTER capability on share\n");
2765 				rc = -EOPNOTSUPP;
2766 				goto out_fail;
2767 			}
2768 		} else {
2769 			cifs_dbg(VFS, "SMB3 or later required for witness option\n");
2770 			rc = -EOPNOTSUPP;
2771 			goto out_fail;
2772 		}
2773 	}
2774 
2775 	/* If the user really knows what they are doing they can override */
2776 	if (tcon->share_flags & SMB2_SHAREFLAG_NO_CACHING) {
2777 		if (ctx->cache_ro)
2778 			cifs_dbg(VFS, "cache=ro requested on mount but NO_CACHING flag set on share\n");
2779 		else if (ctx->cache_rw)
2780 			cifs_dbg(VFS, "cache=singleclient requested on mount but NO_CACHING flag set on share\n");
2781 	}
2782 
2783 	if (ctx->no_lease) {
2784 		if (ses->server->vals->protocol_id == 0) {
2785 			cifs_dbg(VFS,
2786 				"SMB2 or later required for nolease option\n");
2787 			rc = -EOPNOTSUPP;
2788 			goto out_fail;
2789 		} else
2790 			tcon->no_lease = ctx->no_lease;
2791 	}
2792 
2793 	/*
2794 	 * We can have only one retry value for a connection to a share so for
2795 	 * resources mounted more than once to the same server share the last
2796 	 * value passed in for the retry flag is used.
2797 	 */
2798 	tcon->retry = ctx->retry;
2799 	tcon->nocase = ctx->nocase;
2800 	tcon->broken_sparse_sup = ctx->no_sparse;
2801 	tcon->max_cached_dirs = ctx->max_cached_dirs;
2802 	tcon->nodelete = ctx->nodelete;
2803 	tcon->local_lease = ctx->local_lease;
2804 	INIT_LIST_HEAD(&tcon->pending_opens);
2805 	tcon->status = TID_GOOD;
2806 
2807 	INIT_DELAYED_WORK(&tcon->query_interfaces,
2808 			  smb2_query_server_interfaces);
2809 	if (ses->server->dialect >= SMB30_PROT_ID &&
2810 	    (ses->server->capabilities & SMB2_GLOBAL_CAP_MULTI_CHANNEL)) {
2811 		/* schedule query interfaces poll */
2812 		queue_delayed_work(cifsiod_wq, &tcon->query_interfaces,
2813 				   (SMB_INTERFACE_POLL_INTERVAL * HZ));
2814 	}
2815 #ifdef CONFIG_CIFS_DFS_UPCALL
2816 	INIT_DELAYED_WORK(&tcon->dfs_cache_work, dfs_cache_refresh);
2817 #endif
2818 	spin_lock(&cifs_tcp_ses_lock);
2819 	list_add(&tcon->tcon_list, &ses->tcon_list);
2820 	spin_unlock(&cifs_tcp_ses_lock);
2821 
2822 	return tcon;
2823 
2824 out_fail:
2825 	tconInfoFree(tcon, netfs_trace_tcon_ref_free_fail);
2826 	return ERR_PTR(rc);
2827 }
2828 
2829 void
cifs_put_tlink(struct tcon_link * tlink)2830 cifs_put_tlink(struct tcon_link *tlink)
2831 {
2832 	if (!tlink || IS_ERR(tlink))
2833 		return;
2834 
2835 	if (!atomic_dec_and_test(&tlink->tl_count) ||
2836 	    test_bit(TCON_LINK_IN_TREE, &tlink->tl_flags)) {
2837 		tlink->tl_time = jiffies;
2838 		return;
2839 	}
2840 
2841 	if (!IS_ERR(tlink_tcon(tlink)))
2842 		cifs_put_tcon(tlink_tcon(tlink), netfs_trace_tcon_ref_put_tlink);
2843 	kfree(tlink);
2844 }
2845 
2846 static int
compare_mount_options(struct super_block * sb,struct cifs_mnt_data * mnt_data)2847 compare_mount_options(struct super_block *sb, struct cifs_mnt_data *mnt_data)
2848 {
2849 	struct cifs_sb_info *old = CIFS_SB(sb);
2850 	struct cifs_sb_info *new = mnt_data->cifs_sb;
2851 	unsigned int oldflags = old->mnt_cifs_flags & CIFS_MOUNT_MASK;
2852 	unsigned int newflags = new->mnt_cifs_flags & CIFS_MOUNT_MASK;
2853 
2854 	if ((sb->s_flags & CIFS_MS_MASK) != (mnt_data->flags & CIFS_MS_MASK))
2855 		return 0;
2856 
2857 	if (old->mnt_cifs_serverino_autodisabled)
2858 		newflags &= ~CIFS_MOUNT_SERVER_INUM;
2859 
2860 	if (oldflags != newflags)
2861 		return 0;
2862 
2863 	/*
2864 	 * We want to share sb only if we don't specify an r/wsize or
2865 	 * specified r/wsize is greater than or equal to existing one.
2866 	 */
2867 	if (new->ctx->wsize && new->ctx->wsize < old->ctx->wsize)
2868 		return 0;
2869 
2870 	if (new->ctx->rsize && new->ctx->rsize < old->ctx->rsize)
2871 		return 0;
2872 
2873 	if (!uid_eq(old->ctx->linux_uid, new->ctx->linux_uid) ||
2874 	    !gid_eq(old->ctx->linux_gid, new->ctx->linux_gid))
2875 		return 0;
2876 
2877 	if (old->ctx->file_mode != new->ctx->file_mode ||
2878 	    old->ctx->dir_mode != new->ctx->dir_mode)
2879 		return 0;
2880 
2881 	if (strcmp(old->local_nls->charset, new->local_nls->charset))
2882 		return 0;
2883 
2884 	if (old->ctx->acregmax != new->ctx->acregmax)
2885 		return 0;
2886 	if (old->ctx->acdirmax != new->ctx->acdirmax)
2887 		return 0;
2888 	if (old->ctx->closetimeo != new->ctx->closetimeo)
2889 		return 0;
2890 	if (old->ctx->reparse_type != new->ctx->reparse_type)
2891 		return 0;
2892 
2893 	return 1;
2894 }
2895 
match_prepath(struct super_block * sb,struct cifs_tcon * tcon,struct cifs_mnt_data * mnt_data)2896 static int match_prepath(struct super_block *sb,
2897 			 struct cifs_tcon *tcon,
2898 			 struct cifs_mnt_data *mnt_data)
2899 {
2900 	struct smb3_fs_context *ctx = mnt_data->ctx;
2901 	struct cifs_sb_info *old = CIFS_SB(sb);
2902 	struct cifs_sb_info *new = mnt_data->cifs_sb;
2903 	bool old_set = (old->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH) &&
2904 		old->prepath;
2905 	bool new_set = (new->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH) &&
2906 		new->prepath;
2907 
2908 	if (tcon->origin_fullpath &&
2909 	    dfs_src_pathname_equal(tcon->origin_fullpath, ctx->source))
2910 		return 1;
2911 
2912 	if (old_set && new_set && !strcmp(new->prepath, old->prepath))
2913 		return 1;
2914 	else if (!old_set && !new_set)
2915 		return 1;
2916 
2917 	return 0;
2918 }
2919 
2920 int
cifs_match_super(struct super_block * sb,void * data)2921 cifs_match_super(struct super_block *sb, void *data)
2922 {
2923 	struct cifs_mnt_data *mnt_data = data;
2924 	struct smb3_fs_context *ctx;
2925 	struct cifs_sb_info *cifs_sb;
2926 	struct TCP_Server_Info *tcp_srv;
2927 	struct cifs_ses *ses;
2928 	struct cifs_tcon *tcon;
2929 	struct tcon_link *tlink;
2930 	int rc = 0;
2931 
2932 	spin_lock(&cifs_tcp_ses_lock);
2933 	cifs_sb = CIFS_SB(sb);
2934 
2935 	/* We do not want to use a superblock that has been shutdown */
2936 	if (CIFS_MOUNT_SHUTDOWN & cifs_sb->mnt_cifs_flags) {
2937 		spin_unlock(&cifs_tcp_ses_lock);
2938 		return 0;
2939 	}
2940 
2941 	tlink = cifs_get_tlink(cifs_sb_master_tlink(cifs_sb));
2942 	if (IS_ERR_OR_NULL(tlink)) {
2943 		pr_warn_once("%s: skip super matching due to bad tlink(%p)\n",
2944 			     __func__, tlink);
2945 		spin_unlock(&cifs_tcp_ses_lock);
2946 		return 0;
2947 	}
2948 	tcon = tlink_tcon(tlink);
2949 	ses = tcon->ses;
2950 	tcp_srv = ses->server;
2951 
2952 	ctx = mnt_data->ctx;
2953 
2954 	spin_lock(&tcp_srv->srv_lock);
2955 	spin_lock(&ses->ses_lock);
2956 	spin_lock(&ses->chan_lock);
2957 	spin_lock(&tcon->tc_lock);
2958 	if (!match_server(tcp_srv, ctx, true) ||
2959 	    !match_session(ses, ctx, true) ||
2960 	    !match_tcon(tcon, ctx) ||
2961 	    !match_prepath(sb, tcon, mnt_data)) {
2962 		rc = 0;
2963 		goto out;
2964 	}
2965 
2966 	rc = compare_mount_options(sb, mnt_data);
2967 out:
2968 	spin_unlock(&tcon->tc_lock);
2969 	spin_unlock(&ses->chan_lock);
2970 	spin_unlock(&ses->ses_lock);
2971 	spin_unlock(&tcp_srv->srv_lock);
2972 
2973 	spin_unlock(&cifs_tcp_ses_lock);
2974 	cifs_put_tlink(tlink);
2975 	return rc;
2976 }
2977 
2978 #ifdef CONFIG_DEBUG_LOCK_ALLOC
2979 static struct lock_class_key cifs_key[2];
2980 static struct lock_class_key cifs_slock_key[2];
2981 
2982 static inline void
cifs_reclassify_socket4(struct socket * sock)2983 cifs_reclassify_socket4(struct socket *sock)
2984 {
2985 	struct sock *sk = sock->sk;
2986 
2987 	BUG_ON(!sock_allow_reclassification(sk));
2988 	sock_lock_init_class_and_name(sk, "slock-AF_INET-CIFS",
2989 		&cifs_slock_key[0], "sk_lock-AF_INET-CIFS", &cifs_key[0]);
2990 }
2991 
2992 static inline void
cifs_reclassify_socket6(struct socket * sock)2993 cifs_reclassify_socket6(struct socket *sock)
2994 {
2995 	struct sock *sk = sock->sk;
2996 
2997 	BUG_ON(!sock_allow_reclassification(sk));
2998 	sock_lock_init_class_and_name(sk, "slock-AF_INET6-CIFS",
2999 		&cifs_slock_key[1], "sk_lock-AF_INET6-CIFS", &cifs_key[1]);
3000 }
3001 #else
3002 static inline void
cifs_reclassify_socket4(struct socket * sock)3003 cifs_reclassify_socket4(struct socket *sock)
3004 {
3005 }
3006 
3007 static inline void
cifs_reclassify_socket6(struct socket * sock)3008 cifs_reclassify_socket6(struct socket *sock)
3009 {
3010 }
3011 #endif
3012 
3013 /* See RFC1001 section 14 on representation of Netbios names */
rfc1002mangle(char * target,char * source,unsigned int length)3014 static void rfc1002mangle(char *target, char *source, unsigned int length)
3015 {
3016 	unsigned int i, j;
3017 
3018 	for (i = 0, j = 0; i < (length); i++) {
3019 		/* mask a nibble at a time and encode */
3020 		target[j] = 'A' + (0x0F & (source[i] >> 4));
3021 		target[j+1] = 'A' + (0x0F & source[i]);
3022 		j += 2;
3023 	}
3024 
3025 }
3026 
3027 static int
bind_socket(struct TCP_Server_Info * server)3028 bind_socket(struct TCP_Server_Info *server)
3029 {
3030 	int rc = 0;
3031 
3032 	if (server->srcaddr.ss_family != AF_UNSPEC) {
3033 		/* Bind to the specified local IP address */
3034 		struct socket *socket = server->ssocket;
3035 
3036 		rc = kernel_bind(socket,
3037 				 (struct sockaddr *) &server->srcaddr,
3038 				 sizeof(server->srcaddr));
3039 		if (rc < 0) {
3040 			struct sockaddr_in *saddr4;
3041 			struct sockaddr_in6 *saddr6;
3042 
3043 			saddr4 = (struct sockaddr_in *)&server->srcaddr;
3044 			saddr6 = (struct sockaddr_in6 *)&server->srcaddr;
3045 			if (saddr6->sin6_family == AF_INET6)
3046 				cifs_server_dbg(VFS, "Failed to bind to: %pI6c, error: %d\n",
3047 					 &saddr6->sin6_addr, rc);
3048 			else
3049 				cifs_server_dbg(VFS, "Failed to bind to: %pI4, error: %d\n",
3050 					 &saddr4->sin_addr.s_addr, rc);
3051 		}
3052 	}
3053 	return rc;
3054 }
3055 
3056 static int
ip_rfc1001_connect(struct TCP_Server_Info * server)3057 ip_rfc1001_connect(struct TCP_Server_Info *server)
3058 {
3059 	int rc = 0;
3060 	/*
3061 	 * some servers require RFC1001 sessinit before sending
3062 	 * negprot - BB check reconnection in case where second
3063 	 * sessinit is sent but no second negprot
3064 	 */
3065 	struct rfc1002_session_packet req = {};
3066 	struct smb_hdr *smb_buf = (struct smb_hdr *)&req;
3067 	unsigned int len;
3068 
3069 	req.trailer.session_req.called_len = sizeof(req.trailer.session_req.called_name);
3070 
3071 	if (server->server_RFC1001_name[0] != 0)
3072 		rfc1002mangle(req.trailer.session_req.called_name,
3073 			      server->server_RFC1001_name,
3074 			      RFC1001_NAME_LEN_WITH_NULL);
3075 	else
3076 		rfc1002mangle(req.trailer.session_req.called_name,
3077 			      DEFAULT_CIFS_CALLED_NAME,
3078 			      RFC1001_NAME_LEN_WITH_NULL);
3079 
3080 	req.trailer.session_req.calling_len = sizeof(req.trailer.session_req.calling_name);
3081 
3082 	/* calling name ends in null (byte 16) from old smb convention */
3083 	if (server->workstation_RFC1001_name[0] != 0)
3084 		rfc1002mangle(req.trailer.session_req.calling_name,
3085 			      server->workstation_RFC1001_name,
3086 			      RFC1001_NAME_LEN_WITH_NULL);
3087 	else
3088 		rfc1002mangle(req.trailer.session_req.calling_name,
3089 			      "LINUX_CIFS_CLNT",
3090 			      RFC1001_NAME_LEN_WITH_NULL);
3091 
3092 	/*
3093 	 * As per rfc1002, @len must be the number of bytes that follows the
3094 	 * length field of a rfc1002 session request payload.
3095 	 */
3096 	len = sizeof(req) - offsetof(struct rfc1002_session_packet, trailer.session_req);
3097 
3098 	smb_buf->smb_buf_length = cpu_to_be32((RFC1002_SESSION_REQUEST << 24) | len);
3099 	rc = smb_send(server, smb_buf, len);
3100 	/*
3101 	 * RFC1001 layer in at least one server requires very short break before
3102 	 * negprot presumably because not expecting negprot to follow so fast.
3103 	 * This is a simple solution that works without complicating the code
3104 	 * and causes no significant slowing down on mount for everyone else
3105 	 */
3106 	usleep_range(1000, 2000);
3107 
3108 	return rc;
3109 }
3110 
3111 static int
generic_ip_connect(struct TCP_Server_Info * server)3112 generic_ip_connect(struct TCP_Server_Info *server)
3113 {
3114 	struct sockaddr *saddr;
3115 	struct socket *socket;
3116 	int slen, sfamily;
3117 	__be16 sport;
3118 	int rc = 0;
3119 
3120 	saddr = (struct sockaddr *) &server->dstaddr;
3121 
3122 	if (server->dstaddr.ss_family == AF_INET6) {
3123 		struct sockaddr_in6 *ipv6 = (struct sockaddr_in6 *)&server->dstaddr;
3124 
3125 		sport = ipv6->sin6_port;
3126 		slen = sizeof(struct sockaddr_in6);
3127 		sfamily = AF_INET6;
3128 		cifs_dbg(FYI, "%s: connecting to [%pI6]:%d\n", __func__, &ipv6->sin6_addr,
3129 				ntohs(sport));
3130 	} else {
3131 		struct sockaddr_in *ipv4 = (struct sockaddr_in *)&server->dstaddr;
3132 
3133 		sport = ipv4->sin_port;
3134 		slen = sizeof(struct sockaddr_in);
3135 		sfamily = AF_INET;
3136 		cifs_dbg(FYI, "%s: connecting to %pI4:%d\n", __func__, &ipv4->sin_addr,
3137 				ntohs(sport));
3138 	}
3139 
3140 	if (server->ssocket) {
3141 		socket = server->ssocket;
3142 	} else {
3143 		struct net *net = cifs_net_ns(server);
3144 
3145 		rc = sock_create_kern(net, sfamily, SOCK_STREAM, IPPROTO_TCP, &server->ssocket);
3146 		if (rc < 0) {
3147 			cifs_server_dbg(VFS, "Error %d creating socket\n", rc);
3148 			return rc;
3149 		}
3150 
3151 		/*
3152 		 * Grab netns reference for the socket.
3153 		 *
3154 		 * It'll be released here, on error, or in clean_demultiplex_info() upon server
3155 		 * teardown.
3156 		 */
3157 		get_net(net);
3158 
3159 		/* BB other socket options to set KEEPALIVE, NODELAY? */
3160 		cifs_dbg(FYI, "Socket created\n");
3161 		socket = server->ssocket;
3162 		socket->sk->sk_allocation = GFP_NOFS;
3163 		socket->sk->sk_use_task_frag = false;
3164 		if (sfamily == AF_INET6)
3165 			cifs_reclassify_socket6(socket);
3166 		else
3167 			cifs_reclassify_socket4(socket);
3168 	}
3169 
3170 	rc = bind_socket(server);
3171 	if (rc < 0) {
3172 		put_net(cifs_net_ns(server));
3173 		return rc;
3174 	}
3175 
3176 	/*
3177 	 * Eventually check for other socket options to change from
3178 	 * the default. sock_setsockopt not used because it expects
3179 	 * user space buffer
3180 	 */
3181 	socket->sk->sk_rcvtimeo = 7 * HZ;
3182 	socket->sk->sk_sndtimeo = 5 * HZ;
3183 
3184 	/* make the bufsizes depend on wsize/rsize and max requests */
3185 	if (server->noautotune) {
3186 		if (socket->sk->sk_sndbuf < (200 * 1024))
3187 			socket->sk->sk_sndbuf = 200 * 1024;
3188 		if (socket->sk->sk_rcvbuf < (140 * 1024))
3189 			socket->sk->sk_rcvbuf = 140 * 1024;
3190 	}
3191 
3192 	if (server->tcp_nodelay)
3193 		tcp_sock_set_nodelay(socket->sk);
3194 
3195 	cifs_dbg(FYI, "sndbuf %d rcvbuf %d rcvtimeo 0x%lx\n",
3196 		 socket->sk->sk_sndbuf,
3197 		 socket->sk->sk_rcvbuf, socket->sk->sk_rcvtimeo);
3198 
3199 	rc = kernel_connect(socket, saddr, slen,
3200 			    server->noblockcnt ? O_NONBLOCK : 0);
3201 	/*
3202 	 * When mounting SMB root file systems, we do not want to block in
3203 	 * connect. Otherwise bail out and then let cifs_reconnect() perform
3204 	 * reconnect failover - if possible.
3205 	 */
3206 	if (server->noblockcnt && rc == -EINPROGRESS)
3207 		rc = 0;
3208 	if (rc < 0) {
3209 		cifs_dbg(FYI, "Error %d connecting to server\n", rc);
3210 		trace_smb3_connect_err(server->hostname, server->conn_id, &server->dstaddr, rc);
3211 		put_net(cifs_net_ns(server));
3212 		sock_release(socket);
3213 		server->ssocket = NULL;
3214 		return rc;
3215 	}
3216 	trace_smb3_connect_done(server->hostname, server->conn_id, &server->dstaddr);
3217 	if (sport == htons(RFC1001_PORT))
3218 		rc = ip_rfc1001_connect(server);
3219 
3220 	if (rc < 0)
3221 		put_net(cifs_net_ns(server));
3222 
3223 	return rc;
3224 }
3225 
3226 static int
ip_connect(struct TCP_Server_Info * server)3227 ip_connect(struct TCP_Server_Info *server)
3228 {
3229 	__be16 *sport;
3230 	struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&server->dstaddr;
3231 	struct sockaddr_in *addr = (struct sockaddr_in *)&server->dstaddr;
3232 
3233 	if (server->dstaddr.ss_family == AF_INET6)
3234 		sport = &addr6->sin6_port;
3235 	else
3236 		sport = &addr->sin_port;
3237 
3238 	if (*sport == 0) {
3239 		int rc;
3240 
3241 		/* try with 445 port at first */
3242 		*sport = htons(CIFS_PORT);
3243 
3244 		rc = generic_ip_connect(server);
3245 		if (rc >= 0)
3246 			return rc;
3247 
3248 		/* if it failed, try with 139 port */
3249 		*sport = htons(RFC1001_PORT);
3250 	}
3251 
3252 	return generic_ip_connect(server);
3253 }
3254 
3255 #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)3256 void reset_cifs_unix_caps(unsigned int xid, struct cifs_tcon *tcon,
3257 			  struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
3258 {
3259 	/*
3260 	 * If we are reconnecting then should we check to see if
3261 	 * any requested capabilities changed locally e.g. via
3262 	 * remount but we can not do much about it here
3263 	 * if they have (even if we could detect it by the following)
3264 	 * Perhaps we could add a backpointer to array of sb from tcon
3265 	 * or if we change to make all sb to same share the same
3266 	 * sb as NFS - then we only have one backpointer to sb.
3267 	 * What if we wanted to mount the server share twice once with
3268 	 * and once without posixacls or posix paths?
3269 	 */
3270 	__u64 saved_cap = le64_to_cpu(tcon->fsUnixInfo.Capability);
3271 
3272 	if (ctx && ctx->no_linux_ext) {
3273 		tcon->fsUnixInfo.Capability = 0;
3274 		tcon->unix_ext = 0; /* Unix Extensions disabled */
3275 		cifs_dbg(FYI, "Linux protocol extensions disabled\n");
3276 		return;
3277 	} else if (ctx)
3278 		tcon->unix_ext = 1; /* Unix Extensions supported */
3279 
3280 	if (!tcon->unix_ext) {
3281 		cifs_dbg(FYI, "Unix extensions disabled so not set on reconnect\n");
3282 		return;
3283 	}
3284 
3285 	if (!CIFSSMBQFSUnixInfo(xid, tcon)) {
3286 		__u64 cap = le64_to_cpu(tcon->fsUnixInfo.Capability);
3287 
3288 		cifs_dbg(FYI, "unix caps which server supports %lld\n", cap);
3289 		/*
3290 		 * check for reconnect case in which we do not
3291 		 * want to change the mount behavior if we can avoid it
3292 		 */
3293 		if (ctx == NULL) {
3294 			/*
3295 			 * turn off POSIX ACL and PATHNAMES if not set
3296 			 * originally at mount time
3297 			 */
3298 			if ((saved_cap & CIFS_UNIX_POSIX_ACL_CAP) == 0)
3299 				cap &= ~CIFS_UNIX_POSIX_ACL_CAP;
3300 			if ((saved_cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) == 0) {
3301 				if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP)
3302 					cifs_dbg(VFS, "POSIXPATH support change\n");
3303 				cap &= ~CIFS_UNIX_POSIX_PATHNAMES_CAP;
3304 			} else if ((cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) == 0) {
3305 				cifs_dbg(VFS, "possible reconnect error\n");
3306 				cifs_dbg(VFS, "server disabled POSIX path support\n");
3307 			}
3308 		}
3309 
3310 		if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)
3311 			cifs_dbg(VFS, "per-share encryption not supported yet\n");
3312 
3313 		cap &= CIFS_UNIX_CAP_MASK;
3314 		if (ctx && ctx->no_psx_acl)
3315 			cap &= ~CIFS_UNIX_POSIX_ACL_CAP;
3316 		else if (CIFS_UNIX_POSIX_ACL_CAP & cap) {
3317 			cifs_dbg(FYI, "negotiated posix acl support\n");
3318 			if (cifs_sb)
3319 				cifs_sb->mnt_cifs_flags |=
3320 					CIFS_MOUNT_POSIXACL;
3321 		}
3322 
3323 		if (ctx && ctx->posix_paths == 0)
3324 			cap &= ~CIFS_UNIX_POSIX_PATHNAMES_CAP;
3325 		else if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) {
3326 			cifs_dbg(FYI, "negotiate posix pathnames\n");
3327 			if (cifs_sb)
3328 				cifs_sb->mnt_cifs_flags |=
3329 					CIFS_MOUNT_POSIX_PATHS;
3330 		}
3331 
3332 		cifs_dbg(FYI, "Negotiate caps 0x%x\n", (int)cap);
3333 #ifdef CONFIG_CIFS_DEBUG2
3334 		if (cap & CIFS_UNIX_FCNTL_CAP)
3335 			cifs_dbg(FYI, "FCNTL cap\n");
3336 		if (cap & CIFS_UNIX_EXTATTR_CAP)
3337 			cifs_dbg(FYI, "EXTATTR cap\n");
3338 		if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP)
3339 			cifs_dbg(FYI, "POSIX path cap\n");
3340 		if (cap & CIFS_UNIX_XATTR_CAP)
3341 			cifs_dbg(FYI, "XATTR cap\n");
3342 		if (cap & CIFS_UNIX_POSIX_ACL_CAP)
3343 			cifs_dbg(FYI, "POSIX ACL cap\n");
3344 		if (cap & CIFS_UNIX_LARGE_READ_CAP)
3345 			cifs_dbg(FYI, "very large read cap\n");
3346 		if (cap & CIFS_UNIX_LARGE_WRITE_CAP)
3347 			cifs_dbg(FYI, "very large write cap\n");
3348 		if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_CAP)
3349 			cifs_dbg(FYI, "transport encryption cap\n");
3350 		if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)
3351 			cifs_dbg(FYI, "mandatory transport encryption cap\n");
3352 #endif /* CIFS_DEBUG2 */
3353 		if (CIFSSMBSetFSUnixInfo(xid, tcon, cap)) {
3354 			if (ctx == NULL)
3355 				cifs_dbg(FYI, "resetting capabilities failed\n");
3356 			else
3357 				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");
3358 
3359 		}
3360 	}
3361 }
3362 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
3363 
cifs_setup_cifs_sb(struct cifs_sb_info * cifs_sb)3364 int cifs_setup_cifs_sb(struct cifs_sb_info *cifs_sb)
3365 {
3366 	struct smb3_fs_context *ctx = cifs_sb->ctx;
3367 
3368 	INIT_DELAYED_WORK(&cifs_sb->prune_tlinks, cifs_prune_tlinks);
3369 
3370 	spin_lock_init(&cifs_sb->tlink_tree_lock);
3371 	cifs_sb->tlink_tree = RB_ROOT;
3372 
3373 	cifs_dbg(FYI, "file mode: %04ho  dir mode: %04ho\n",
3374 		 ctx->file_mode, ctx->dir_mode);
3375 
3376 	/* this is needed for ASCII cp to Unicode converts */
3377 	if (ctx->iocharset == NULL) {
3378 		/* load_nls_default cannot return null */
3379 		cifs_sb->local_nls = load_nls_default();
3380 	} else {
3381 		cifs_sb->local_nls = load_nls(ctx->iocharset);
3382 		if (cifs_sb->local_nls == NULL) {
3383 			cifs_dbg(VFS, "CIFS mount error: iocharset %s not found\n",
3384 				 ctx->iocharset);
3385 			return -ELIBACC;
3386 		}
3387 	}
3388 	ctx->local_nls = cifs_sb->local_nls;
3389 
3390 	smb3_update_mnt_flags(cifs_sb);
3391 
3392 	if (ctx->direct_io)
3393 		cifs_dbg(FYI, "mounting share using direct i/o\n");
3394 	if (ctx->cache_ro) {
3395 		cifs_dbg(VFS, "mounting share with read only caching. Ensure that the share will not be modified while in use.\n");
3396 		cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_RO_CACHE;
3397 	} else if (ctx->cache_rw) {
3398 		cifs_dbg(VFS, "mounting share in single client RW caching mode. Ensure that no other systems will be accessing the share.\n");
3399 		cifs_sb->mnt_cifs_flags |= (CIFS_MOUNT_RO_CACHE |
3400 					    CIFS_MOUNT_RW_CACHE);
3401 	}
3402 
3403 	if ((ctx->cifs_acl) && (ctx->dynperm))
3404 		cifs_dbg(VFS, "mount option dynperm ignored if cifsacl mount option supported\n");
3405 
3406 	if (ctx->prepath) {
3407 		cifs_sb->prepath = kstrdup(ctx->prepath, GFP_KERNEL);
3408 		if (cifs_sb->prepath == NULL)
3409 			return -ENOMEM;
3410 		cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
3411 	}
3412 
3413 	return 0;
3414 }
3415 
3416 /* Release all succeed connections */
cifs_mount_put_conns(struct cifs_mount_ctx * mnt_ctx)3417 void cifs_mount_put_conns(struct cifs_mount_ctx *mnt_ctx)
3418 {
3419 	int rc = 0;
3420 
3421 	if (mnt_ctx->tcon)
3422 		cifs_put_tcon(mnt_ctx->tcon, netfs_trace_tcon_ref_put_mnt_ctx);
3423 	else if (mnt_ctx->ses)
3424 		cifs_put_smb_ses(mnt_ctx->ses);
3425 	else if (mnt_ctx->server)
3426 		cifs_put_tcp_session(mnt_ctx->server, 0);
3427 	mnt_ctx->ses = NULL;
3428 	mnt_ctx->tcon = NULL;
3429 	mnt_ctx->server = NULL;
3430 	mnt_ctx->cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_POSIX_PATHS;
3431 	free_xid(mnt_ctx->xid);
3432 }
3433 
cifs_mount_get_session(struct cifs_mount_ctx * mnt_ctx)3434 int cifs_mount_get_session(struct cifs_mount_ctx *mnt_ctx)
3435 {
3436 	struct TCP_Server_Info *server = NULL;
3437 	struct smb3_fs_context *ctx;
3438 	struct cifs_ses *ses = NULL;
3439 	unsigned int xid;
3440 	int rc = 0;
3441 
3442 	xid = get_xid();
3443 
3444 	if (WARN_ON_ONCE(!mnt_ctx || !mnt_ctx->fs_ctx)) {
3445 		rc = -EINVAL;
3446 		goto out;
3447 	}
3448 	ctx = mnt_ctx->fs_ctx;
3449 
3450 	/* get a reference to a tcp session */
3451 	server = cifs_get_tcp_session(ctx, NULL);
3452 	if (IS_ERR(server)) {
3453 		rc = PTR_ERR(server);
3454 		server = NULL;
3455 		goto out;
3456 	}
3457 
3458 	/* get a reference to a SMB session */
3459 	ses = cifs_get_smb_ses(server, ctx);
3460 	if (IS_ERR(ses)) {
3461 		rc = PTR_ERR(ses);
3462 		ses = NULL;
3463 		goto out;
3464 	}
3465 
3466 	if ((ctx->persistent == true) && (!(ses->server->capabilities &
3467 					    SMB2_GLOBAL_CAP_PERSISTENT_HANDLES))) {
3468 		cifs_server_dbg(VFS, "persistent handles not supported by server\n");
3469 		rc = -EOPNOTSUPP;
3470 	}
3471 
3472 out:
3473 	mnt_ctx->xid = xid;
3474 	mnt_ctx->server = server;
3475 	mnt_ctx->ses = ses;
3476 	mnt_ctx->tcon = NULL;
3477 
3478 	return rc;
3479 }
3480 
cifs_mount_get_tcon(struct cifs_mount_ctx * mnt_ctx)3481 int cifs_mount_get_tcon(struct cifs_mount_ctx *mnt_ctx)
3482 {
3483 	struct TCP_Server_Info *server;
3484 	struct cifs_sb_info *cifs_sb;
3485 	struct smb3_fs_context *ctx;
3486 	struct cifs_tcon *tcon = NULL;
3487 	int rc = 0;
3488 
3489 	if (WARN_ON_ONCE(!mnt_ctx || !mnt_ctx->server || !mnt_ctx->ses || !mnt_ctx->fs_ctx ||
3490 			 !mnt_ctx->cifs_sb)) {
3491 		rc = -EINVAL;
3492 		goto out;
3493 	}
3494 	server = mnt_ctx->server;
3495 	ctx = mnt_ctx->fs_ctx;
3496 	cifs_sb = mnt_ctx->cifs_sb;
3497 
3498 	/* search for existing tcon to this server share */
3499 	tcon = cifs_get_tcon(mnt_ctx->ses, ctx);
3500 	if (IS_ERR(tcon)) {
3501 		rc = PTR_ERR(tcon);
3502 		tcon = NULL;
3503 		goto out;
3504 	}
3505 
3506 	/* if new SMB3.11 POSIX extensions are supported do not remap / and \ */
3507 	if (tcon->posix_extensions)
3508 		cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_POSIX_PATHS;
3509 
3510 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
3511 	/* tell server which Unix caps we support */
3512 	if (cap_unix(tcon->ses)) {
3513 		/*
3514 		 * reset of caps checks mount to see if unix extensions disabled
3515 		 * for just this mount.
3516 		 */
3517 		reset_cifs_unix_caps(mnt_ctx->xid, tcon, cifs_sb, ctx);
3518 		spin_lock(&tcon->ses->server->srv_lock);
3519 		if ((tcon->ses->server->tcpStatus == CifsNeedReconnect) &&
3520 		    (le64_to_cpu(tcon->fsUnixInfo.Capability) &
3521 		     CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)) {
3522 			spin_unlock(&tcon->ses->server->srv_lock);
3523 			rc = -EACCES;
3524 			goto out;
3525 		}
3526 		spin_unlock(&tcon->ses->server->srv_lock);
3527 	} else
3528 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
3529 		tcon->unix_ext = 0; /* server does not support them */
3530 
3531 	/* do not care if a following call succeed - informational */
3532 	if (!tcon->pipe && server->ops->qfs_tcon) {
3533 		server->ops->qfs_tcon(mnt_ctx->xid, tcon, cifs_sb);
3534 		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RO_CACHE) {
3535 			if (tcon->fsDevInfo.DeviceCharacteristics &
3536 			    cpu_to_le32(FILE_READ_ONLY_DEVICE))
3537 				cifs_dbg(VFS, "mounted to read only share\n");
3538 			else if ((cifs_sb->mnt_cifs_flags &
3539 				  CIFS_MOUNT_RW_CACHE) == 0)
3540 				cifs_dbg(VFS, "read only mount of RW share\n");
3541 			/* no need to log a RW mount of a typical RW share */
3542 		}
3543 	}
3544 
3545 	/*
3546 	 * Clamp the rsize/wsize mount arguments if they are too big for the server
3547 	 * and set the rsize/wsize to the negotiated values if not passed in by
3548 	 * the user on mount
3549 	 */
3550 	if ((cifs_sb->ctx->wsize == 0) ||
3551 	    (cifs_sb->ctx->wsize > server->ops->negotiate_wsize(tcon, ctx))) {
3552 		cifs_sb->ctx->wsize =
3553 			round_down(server->ops->negotiate_wsize(tcon, ctx), PAGE_SIZE);
3554 		/*
3555 		 * in the very unlikely event that the server sent a max write size under PAGE_SIZE,
3556 		 * (which would get rounded down to 0) then reset wsize to absolute minimum eg 4096
3557 		 */
3558 		if (cifs_sb->ctx->wsize == 0) {
3559 			cifs_sb->ctx->wsize = PAGE_SIZE;
3560 			cifs_dbg(VFS, "wsize too small, reset to minimum ie PAGE_SIZE, usually 4096\n");
3561 		}
3562 	}
3563 	if ((cifs_sb->ctx->rsize == 0) ||
3564 	    (cifs_sb->ctx->rsize > server->ops->negotiate_rsize(tcon, ctx)))
3565 		cifs_sb->ctx->rsize = server->ops->negotiate_rsize(tcon, ctx);
3566 
3567 	/*
3568 	 * The cookie is initialized from volume info returned above.
3569 	 * Inside cifs_fscache_get_super_cookie it checks
3570 	 * that we do not get super cookie twice.
3571 	 */
3572 	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_FSCACHE)
3573 		cifs_fscache_get_super_cookie(tcon);
3574 
3575 out:
3576 	mnt_ctx->tcon = tcon;
3577 	return rc;
3578 }
3579 
mount_setup_tlink(struct cifs_sb_info * cifs_sb,struct cifs_ses * ses,struct cifs_tcon * tcon)3580 static int mount_setup_tlink(struct cifs_sb_info *cifs_sb, struct cifs_ses *ses,
3581 			     struct cifs_tcon *tcon)
3582 {
3583 	struct tcon_link *tlink;
3584 
3585 	/* hang the tcon off of the superblock */
3586 	tlink = kzalloc(sizeof(*tlink), GFP_KERNEL);
3587 	if (tlink == NULL)
3588 		return -ENOMEM;
3589 
3590 	tlink->tl_uid = ses->linux_uid;
3591 	tlink->tl_tcon = tcon;
3592 	tlink->tl_time = jiffies;
3593 	set_bit(TCON_LINK_MASTER, &tlink->tl_flags);
3594 	set_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
3595 
3596 	cifs_sb->master_tlink = tlink;
3597 	spin_lock(&cifs_sb->tlink_tree_lock);
3598 	tlink_rb_insert(&cifs_sb->tlink_tree, tlink);
3599 	spin_unlock(&cifs_sb->tlink_tree_lock);
3600 
3601 	queue_delayed_work(cifsiod_wq, &cifs_sb->prune_tlinks,
3602 				TLINK_IDLE_EXPIRE);
3603 	return 0;
3604 }
3605 
3606 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)3607 cifs_are_all_path_components_accessible(struct TCP_Server_Info *server,
3608 					unsigned int xid,
3609 					struct cifs_tcon *tcon,
3610 					struct cifs_sb_info *cifs_sb,
3611 					char *full_path,
3612 					int added_treename)
3613 {
3614 	int rc;
3615 	char *s;
3616 	char sep, tmp;
3617 	int skip = added_treename ? 1 : 0;
3618 
3619 	sep = CIFS_DIR_SEP(cifs_sb);
3620 	s = full_path;
3621 
3622 	rc = server->ops->is_path_accessible(xid, tcon, cifs_sb, "");
3623 	while (rc == 0) {
3624 		/* skip separators */
3625 		while (*s == sep)
3626 			s++;
3627 		if (!*s)
3628 			break;
3629 		/* next separator */
3630 		while (*s && *s != sep)
3631 			s++;
3632 		/*
3633 		 * if the treename is added, we then have to skip the first
3634 		 * part within the separators
3635 		 */
3636 		if (skip) {
3637 			skip = 0;
3638 			continue;
3639 		}
3640 		/*
3641 		 * temporarily null-terminate the path at the end of
3642 		 * the current component
3643 		 */
3644 		tmp = *s;
3645 		*s = 0;
3646 		rc = server->ops->is_path_accessible(xid, tcon, cifs_sb,
3647 						     full_path);
3648 		*s = tmp;
3649 	}
3650 	return rc;
3651 }
3652 
3653 /*
3654  * Check if path is remote (i.e. a DFS share).
3655  *
3656  * Return -EREMOTE if it is, otherwise 0 or -errno.
3657  */
cifs_is_path_remote(struct cifs_mount_ctx * mnt_ctx)3658 int cifs_is_path_remote(struct cifs_mount_ctx *mnt_ctx)
3659 {
3660 	int rc;
3661 	struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3662 	struct TCP_Server_Info *server = mnt_ctx->server;
3663 	unsigned int xid = mnt_ctx->xid;
3664 	struct cifs_tcon *tcon = mnt_ctx->tcon;
3665 	struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
3666 	char *full_path;
3667 
3668 	if (!server->ops->is_path_accessible)
3669 		return -EOPNOTSUPP;
3670 
3671 	/*
3672 	 * cifs_build_path_to_root works only when we have a valid tcon
3673 	 */
3674 	full_path = cifs_build_path_to_root(ctx, cifs_sb, tcon,
3675 					    tcon->Flags & SMB_SHARE_IS_IN_DFS);
3676 	if (full_path == NULL)
3677 		return -ENOMEM;
3678 
3679 	cifs_dbg(FYI, "%s: full_path: %s\n", __func__, full_path);
3680 
3681 	rc = server->ops->is_path_accessible(xid, tcon, cifs_sb,
3682 					     full_path);
3683 	if (rc != 0 && rc != -EREMOTE)
3684 		goto out;
3685 
3686 	if (rc != -EREMOTE) {
3687 		rc = cifs_are_all_path_components_accessible(server, xid, tcon,
3688 			cifs_sb, full_path, tcon->Flags & SMB_SHARE_IS_IN_DFS);
3689 		if (rc != 0) {
3690 			cifs_server_dbg(VFS, "cannot query dirs between root and final path, enabling CIFS_MOUNT_USE_PREFIX_PATH\n");
3691 			cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
3692 			rc = 0;
3693 		}
3694 	}
3695 
3696 out:
3697 	kfree(full_path);
3698 	return rc;
3699 }
3700 
3701 #ifdef CONFIG_CIFS_DFS_UPCALL
cifs_mount(struct cifs_sb_info * cifs_sb,struct smb3_fs_context * ctx)3702 int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
3703 {
3704 	struct cifs_mount_ctx mnt_ctx = { .cifs_sb = cifs_sb, .fs_ctx = ctx, };
3705 	int rc;
3706 
3707 	rc = dfs_mount_share(&mnt_ctx);
3708 	if (rc)
3709 		goto error;
3710 	if (!ctx->dfs_conn)
3711 		goto out;
3712 
3713 	/*
3714 	 * After reconnecting to a different server, unique ids won't match anymore, so we disable
3715 	 * serverino. This prevents dentry revalidation to think the dentry are stale (ESTALE).
3716 	 */
3717 	cifs_autodisable_serverino(cifs_sb);
3718 	/*
3719 	 * Force the use of prefix path to support failover on DFS paths that resolve to targets
3720 	 * that have different prefix paths.
3721 	 */
3722 	cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
3723 	kfree(cifs_sb->prepath);
3724 	cifs_sb->prepath = ctx->prepath;
3725 	ctx->prepath = NULL;
3726 
3727 out:
3728 	cifs_try_adding_channels(mnt_ctx.ses);
3729 	rc = mount_setup_tlink(cifs_sb, mnt_ctx.ses, mnt_ctx.tcon);
3730 	if (rc)
3731 		goto error;
3732 
3733 	free_xid(mnt_ctx.xid);
3734 	return rc;
3735 
3736 error:
3737 	cifs_mount_put_conns(&mnt_ctx);
3738 	return rc;
3739 }
3740 #else
cifs_mount(struct cifs_sb_info * cifs_sb,struct smb3_fs_context * ctx)3741 int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
3742 {
3743 	int rc = 0;
3744 	struct cifs_mount_ctx mnt_ctx = { .cifs_sb = cifs_sb, .fs_ctx = ctx, };
3745 
3746 	rc = cifs_mount_get_session(&mnt_ctx);
3747 	if (rc)
3748 		goto error;
3749 
3750 	rc = cifs_mount_get_tcon(&mnt_ctx);
3751 	if (!rc) {
3752 		/*
3753 		 * Prevent superblock from being created with any missing
3754 		 * connections.
3755 		 */
3756 		if (WARN_ON(!mnt_ctx.server))
3757 			rc = -EHOSTDOWN;
3758 		else if (WARN_ON(!mnt_ctx.ses))
3759 			rc = -EACCES;
3760 		else if (WARN_ON(!mnt_ctx.tcon))
3761 			rc = -ENOENT;
3762 	}
3763 	if (rc)
3764 		goto error;
3765 
3766 	rc = cifs_is_path_remote(&mnt_ctx);
3767 	if (rc == -EREMOTE)
3768 		rc = -EOPNOTSUPP;
3769 	if (rc)
3770 		goto error;
3771 
3772 	rc = mount_setup_tlink(cifs_sb, mnt_ctx.ses, mnt_ctx.tcon);
3773 	if (rc)
3774 		goto error;
3775 
3776 	free_xid(mnt_ctx.xid);
3777 	return rc;
3778 
3779 error:
3780 	cifs_mount_put_conns(&mnt_ctx);
3781 	return rc;
3782 }
3783 #endif
3784 
3785 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
3786 /*
3787  * Issue a TREE_CONNECT request.
3788  */
3789 int
CIFSTCon(const unsigned int xid,struct cifs_ses * ses,const char * tree,struct cifs_tcon * tcon,const struct nls_table * nls_codepage)3790 CIFSTCon(const unsigned int xid, struct cifs_ses *ses,
3791 	 const char *tree, struct cifs_tcon *tcon,
3792 	 const struct nls_table *nls_codepage)
3793 {
3794 	struct smb_hdr *smb_buffer;
3795 	struct smb_hdr *smb_buffer_response;
3796 	TCONX_REQ *pSMB;
3797 	TCONX_RSP *pSMBr;
3798 	unsigned char *bcc_ptr;
3799 	int rc = 0;
3800 	int length;
3801 	__u16 bytes_left, count;
3802 
3803 	if (ses == NULL)
3804 		return -EIO;
3805 
3806 	smb_buffer = cifs_buf_get();
3807 	if (smb_buffer == NULL)
3808 		return -ENOMEM;
3809 
3810 	smb_buffer_response = smb_buffer;
3811 
3812 	header_assemble(smb_buffer, SMB_COM_TREE_CONNECT_ANDX,
3813 			NULL /*no tid */, 4 /*wct */);
3814 
3815 	smb_buffer->Mid = get_next_mid(ses->server);
3816 	smb_buffer->Uid = ses->Suid;
3817 	pSMB = (TCONX_REQ *) smb_buffer;
3818 	pSMBr = (TCONX_RSP *) smb_buffer_response;
3819 
3820 	pSMB->AndXCommand = 0xFF;
3821 	pSMB->Flags = cpu_to_le16(TCON_EXTENDED_SECINFO);
3822 	bcc_ptr = &pSMB->Password[0];
3823 
3824 	pSMB->PasswordLength = cpu_to_le16(1);	/* minimum */
3825 	*bcc_ptr = 0; /* password is null byte */
3826 	bcc_ptr++;              /* skip password */
3827 	/* already aligned so no need to do it below */
3828 
3829 	if (ses->server->sign)
3830 		smb_buffer->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
3831 
3832 	if (ses->capabilities & CAP_STATUS32)
3833 		smb_buffer->Flags2 |= SMBFLG2_ERR_STATUS;
3834 
3835 	if (ses->capabilities & CAP_DFS)
3836 		smb_buffer->Flags2 |= SMBFLG2_DFS;
3837 
3838 	if (ses->capabilities & CAP_UNICODE) {
3839 		smb_buffer->Flags2 |= SMBFLG2_UNICODE;
3840 		length =
3841 		    cifs_strtoUTF16((__le16 *) bcc_ptr, tree,
3842 			6 /* max utf8 char length in bytes */ *
3843 			(/* server len*/ + 256 /* share len */), nls_codepage);
3844 		bcc_ptr += 2 * length;	/* convert num 16 bit words to bytes */
3845 		bcc_ptr += 2;	/* skip trailing null */
3846 	} else {		/* ASCII */
3847 		strcpy(bcc_ptr, tree);
3848 		bcc_ptr += strlen(tree) + 1;
3849 	}
3850 	strcpy(bcc_ptr, "?????");
3851 	bcc_ptr += strlen("?????");
3852 	bcc_ptr += 1;
3853 	count = bcc_ptr - &pSMB->Password[0];
3854 	be32_add_cpu(&pSMB->hdr.smb_buf_length, count);
3855 	pSMB->ByteCount = cpu_to_le16(count);
3856 
3857 	rc = SendReceive(xid, ses, smb_buffer, smb_buffer_response, &length,
3858 			 0);
3859 
3860 	/* above now done in SendReceive */
3861 	if (rc == 0) {
3862 		bool is_unicode;
3863 
3864 		tcon->tid = smb_buffer_response->Tid;
3865 		bcc_ptr = pByteArea(smb_buffer_response);
3866 		bytes_left = get_bcc(smb_buffer_response);
3867 		length = strnlen(bcc_ptr, bytes_left - 2);
3868 		if (smb_buffer->Flags2 & SMBFLG2_UNICODE)
3869 			is_unicode = true;
3870 		else
3871 			is_unicode = false;
3872 
3873 
3874 		/* skip service field (NB: this field is always ASCII) */
3875 		if (length == 3) {
3876 			if ((bcc_ptr[0] == 'I') && (bcc_ptr[1] == 'P') &&
3877 			    (bcc_ptr[2] == 'C')) {
3878 				cifs_dbg(FYI, "IPC connection\n");
3879 				tcon->ipc = true;
3880 				tcon->pipe = true;
3881 			}
3882 		} else if (length == 2) {
3883 			if ((bcc_ptr[0] == 'A') && (bcc_ptr[1] == ':')) {
3884 				/* the most common case */
3885 				cifs_dbg(FYI, "disk share connection\n");
3886 			}
3887 		}
3888 		bcc_ptr += length + 1;
3889 		bytes_left -= (length + 1);
3890 		strscpy(tcon->tree_name, tree, sizeof(tcon->tree_name));
3891 
3892 		/* mostly informational -- no need to fail on error here */
3893 		kfree(tcon->nativeFileSystem);
3894 		tcon->nativeFileSystem = cifs_strndup_from_utf16(bcc_ptr,
3895 						      bytes_left, is_unicode,
3896 						      nls_codepage);
3897 
3898 		cifs_dbg(FYI, "nativeFileSystem=%s\n", tcon->nativeFileSystem);
3899 
3900 		if ((smb_buffer_response->WordCount == 3) ||
3901 			 (smb_buffer_response->WordCount == 7))
3902 			/* field is in same location */
3903 			tcon->Flags = le16_to_cpu(pSMBr->OptionalSupport);
3904 		else
3905 			tcon->Flags = 0;
3906 		cifs_dbg(FYI, "Tcon flags: 0x%x\n", tcon->Flags);
3907 
3908 		/*
3909 		 * reset_cifs_unix_caps calls QFSInfo which requires
3910 		 * need_reconnect to be false, but we would not need to call
3911 		 * reset_caps if this were not a reconnect case so must check
3912 		 * need_reconnect flag here.  The caller will also clear
3913 		 * need_reconnect when tcon was successful but needed to be
3914 		 * cleared earlier in the case of unix extensions reconnect
3915 		 */
3916 		if (tcon->need_reconnect && tcon->unix_ext) {
3917 			cifs_dbg(FYI, "resetting caps for %s\n", tcon->tree_name);
3918 			tcon->need_reconnect = false;
3919 			reset_cifs_unix_caps(xid, tcon, NULL, NULL);
3920 		}
3921 	}
3922 	cifs_buf_release(smb_buffer);
3923 	return rc;
3924 }
3925 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
3926 
delayed_free(struct rcu_head * p)3927 static void delayed_free(struct rcu_head *p)
3928 {
3929 	struct cifs_sb_info *cifs_sb = container_of(p, struct cifs_sb_info, rcu);
3930 
3931 	unload_nls(cifs_sb->local_nls);
3932 	smb3_cleanup_fs_context(cifs_sb->ctx);
3933 	kfree(cifs_sb);
3934 }
3935 
3936 void
cifs_umount(struct cifs_sb_info * cifs_sb)3937 cifs_umount(struct cifs_sb_info *cifs_sb)
3938 {
3939 	struct rb_root *root = &cifs_sb->tlink_tree;
3940 	struct rb_node *node;
3941 	struct tcon_link *tlink;
3942 
3943 	cancel_delayed_work_sync(&cifs_sb->prune_tlinks);
3944 
3945 	spin_lock(&cifs_sb->tlink_tree_lock);
3946 	while ((node = rb_first(root))) {
3947 		tlink = rb_entry(node, struct tcon_link, tl_rbnode);
3948 		cifs_get_tlink(tlink);
3949 		clear_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
3950 		rb_erase(node, root);
3951 
3952 		spin_unlock(&cifs_sb->tlink_tree_lock);
3953 		cifs_put_tlink(tlink);
3954 		spin_lock(&cifs_sb->tlink_tree_lock);
3955 	}
3956 	spin_unlock(&cifs_sb->tlink_tree_lock);
3957 
3958 	kfree(cifs_sb->prepath);
3959 	call_rcu(&cifs_sb->rcu, delayed_free);
3960 }
3961 
3962 int
cifs_negotiate_protocol(const unsigned int xid,struct cifs_ses * ses,struct TCP_Server_Info * server)3963 cifs_negotiate_protocol(const unsigned int xid, struct cifs_ses *ses,
3964 			struct TCP_Server_Info *server)
3965 {
3966 	int rc = 0;
3967 
3968 	if (!server->ops->need_neg || !server->ops->negotiate)
3969 		return -ENOSYS;
3970 
3971 	/* only send once per connect */
3972 	spin_lock(&server->srv_lock);
3973 	if (server->tcpStatus != CifsGood &&
3974 	    server->tcpStatus != CifsNew &&
3975 	    server->tcpStatus != CifsNeedNegotiate) {
3976 		spin_unlock(&server->srv_lock);
3977 		return -EHOSTDOWN;
3978 	}
3979 
3980 	if (!server->ops->need_neg(server) &&
3981 	    server->tcpStatus == CifsGood) {
3982 		spin_unlock(&server->srv_lock);
3983 		return 0;
3984 	}
3985 
3986 	server->tcpStatus = CifsInNegotiate;
3987 	spin_unlock(&server->srv_lock);
3988 
3989 	rc = server->ops->negotiate(xid, ses, server);
3990 	if (rc == 0) {
3991 		spin_lock(&server->srv_lock);
3992 		if (server->tcpStatus == CifsInNegotiate)
3993 			server->tcpStatus = CifsGood;
3994 		else
3995 			rc = -EHOSTDOWN;
3996 		spin_unlock(&server->srv_lock);
3997 	} else {
3998 		spin_lock(&server->srv_lock);
3999 		if (server->tcpStatus == CifsInNegotiate)
4000 			server->tcpStatus = CifsNeedNegotiate;
4001 		spin_unlock(&server->srv_lock);
4002 	}
4003 
4004 	return rc;
4005 }
4006 
4007 int
cifs_setup_session(const unsigned int xid,struct cifs_ses * ses,struct TCP_Server_Info * server,struct nls_table * nls_info)4008 cifs_setup_session(const unsigned int xid, struct cifs_ses *ses,
4009 		   struct TCP_Server_Info *server,
4010 		   struct nls_table *nls_info)
4011 {
4012 	int rc = -ENOSYS;
4013 	struct TCP_Server_Info *pserver = SERVER_IS_CHAN(server) ? server->primary_server : server;
4014 	struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&pserver->dstaddr;
4015 	struct sockaddr_in *addr = (struct sockaddr_in *)&pserver->dstaddr;
4016 	bool is_binding = false;
4017 
4018 	spin_lock(&ses->ses_lock);
4019 	cifs_dbg(FYI, "%s: channel connect bitmap: 0x%lx\n",
4020 		 __func__, ses->chans_need_reconnect);
4021 
4022 	if (ses->ses_status != SES_GOOD &&
4023 	    ses->ses_status != SES_NEW &&
4024 	    ses->ses_status != SES_NEED_RECON) {
4025 		spin_unlock(&ses->ses_lock);
4026 		return -EHOSTDOWN;
4027 	}
4028 
4029 	/* only send once per connect */
4030 	spin_lock(&ses->chan_lock);
4031 	if (CIFS_ALL_CHANS_GOOD(ses)) {
4032 		if (ses->ses_status == SES_NEED_RECON)
4033 			ses->ses_status = SES_GOOD;
4034 		spin_unlock(&ses->chan_lock);
4035 		spin_unlock(&ses->ses_lock);
4036 		return 0;
4037 	}
4038 
4039 	cifs_chan_set_in_reconnect(ses, server);
4040 	is_binding = !CIFS_ALL_CHANS_NEED_RECONNECT(ses);
4041 	spin_unlock(&ses->chan_lock);
4042 
4043 	if (!is_binding) {
4044 		ses->ses_status = SES_IN_SETUP;
4045 
4046 		/* force iface_list refresh */
4047 		ses->iface_last_update = 0;
4048 	}
4049 	spin_unlock(&ses->ses_lock);
4050 
4051 	/* update ses ip_addr only for primary chan */
4052 	if (server == pserver) {
4053 		if (server->dstaddr.ss_family == AF_INET6)
4054 			scnprintf(ses->ip_addr, sizeof(ses->ip_addr), "%pI6", &addr6->sin6_addr);
4055 		else
4056 			scnprintf(ses->ip_addr, sizeof(ses->ip_addr), "%pI4", &addr->sin_addr);
4057 	}
4058 
4059 	if (!is_binding) {
4060 		ses->capabilities = server->capabilities;
4061 		if (!linuxExtEnabled)
4062 			ses->capabilities &= (~server->vals->cap_unix);
4063 
4064 		if (ses->auth_key.response) {
4065 			cifs_dbg(FYI, "Free previous auth_key.response = %p\n",
4066 				 ses->auth_key.response);
4067 			kfree_sensitive(ses->auth_key.response);
4068 			ses->auth_key.response = NULL;
4069 			ses->auth_key.len = 0;
4070 		}
4071 	}
4072 
4073 	cifs_dbg(FYI, "Security Mode: 0x%x Capabilities: 0x%x TimeAdjust: %d\n",
4074 		 server->sec_mode, server->capabilities, server->timeAdj);
4075 
4076 	if (server->ops->sess_setup)
4077 		rc = server->ops->sess_setup(xid, ses, server, nls_info);
4078 
4079 	if (rc) {
4080 		cifs_server_dbg(VFS, "Send error in SessSetup = %d\n", rc);
4081 		spin_lock(&ses->ses_lock);
4082 		if (ses->ses_status == SES_IN_SETUP)
4083 			ses->ses_status = SES_NEED_RECON;
4084 		spin_lock(&ses->chan_lock);
4085 		cifs_chan_clear_in_reconnect(ses, server);
4086 		spin_unlock(&ses->chan_lock);
4087 		spin_unlock(&ses->ses_lock);
4088 	} else {
4089 		spin_lock(&ses->ses_lock);
4090 		if (ses->ses_status == SES_IN_SETUP)
4091 			ses->ses_status = SES_GOOD;
4092 		spin_lock(&ses->chan_lock);
4093 		cifs_chan_clear_in_reconnect(ses, server);
4094 		cifs_chan_clear_need_reconnect(ses, server);
4095 		spin_unlock(&ses->chan_lock);
4096 		spin_unlock(&ses->ses_lock);
4097 	}
4098 
4099 	return rc;
4100 }
4101 
4102 static int
cifs_set_vol_auth(struct smb3_fs_context * ctx,struct cifs_ses * ses)4103 cifs_set_vol_auth(struct smb3_fs_context *ctx, struct cifs_ses *ses)
4104 {
4105 	ctx->sectype = ses->sectype;
4106 
4107 	/* krb5 is special, since we don't need username or pw */
4108 	if (ctx->sectype == Kerberos)
4109 		return 0;
4110 
4111 	return cifs_set_cifscreds(ctx, ses);
4112 }
4113 
4114 static struct cifs_tcon *
cifs_construct_tcon(struct cifs_sb_info * cifs_sb,kuid_t fsuid)4115 cifs_construct_tcon(struct cifs_sb_info *cifs_sb, kuid_t fsuid)
4116 {
4117 	int rc;
4118 	struct cifs_tcon *master_tcon = cifs_sb_master_tcon(cifs_sb);
4119 	struct cifs_ses *ses;
4120 	struct cifs_tcon *tcon = NULL;
4121 	struct smb3_fs_context *ctx;
4122 	char *origin_fullpath = NULL;
4123 
4124 	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
4125 	if (ctx == NULL)
4126 		return ERR_PTR(-ENOMEM);
4127 
4128 	ctx->local_nls = cifs_sb->local_nls;
4129 	ctx->linux_uid = fsuid;
4130 	ctx->cred_uid = fsuid;
4131 	ctx->UNC = master_tcon->tree_name;
4132 	ctx->retry = master_tcon->retry;
4133 	ctx->nocase = master_tcon->nocase;
4134 	ctx->nohandlecache = master_tcon->nohandlecache;
4135 	ctx->local_lease = master_tcon->local_lease;
4136 	ctx->no_lease = master_tcon->no_lease;
4137 	ctx->resilient = master_tcon->use_resilient;
4138 	ctx->persistent = master_tcon->use_persistent;
4139 	ctx->handle_timeout = master_tcon->handle_timeout;
4140 	ctx->no_linux_ext = !master_tcon->unix_ext;
4141 	ctx->linux_ext = master_tcon->posix_extensions;
4142 	ctx->sectype = master_tcon->ses->sectype;
4143 	ctx->sign = master_tcon->ses->sign;
4144 	ctx->seal = master_tcon->seal;
4145 	ctx->witness = master_tcon->use_witness;
4146 	ctx->dfs_root_ses = master_tcon->ses->dfs_root_ses;
4147 
4148 	rc = cifs_set_vol_auth(ctx, master_tcon->ses);
4149 	if (rc) {
4150 		tcon = ERR_PTR(rc);
4151 		goto out;
4152 	}
4153 
4154 	/* get a reference for the same TCP session */
4155 	spin_lock(&cifs_tcp_ses_lock);
4156 	++master_tcon->ses->server->srv_count;
4157 	spin_unlock(&cifs_tcp_ses_lock);
4158 
4159 	ses = cifs_get_smb_ses(master_tcon->ses->server, ctx);
4160 	if (IS_ERR(ses)) {
4161 		tcon = ERR_CAST(ses);
4162 		cifs_put_tcp_session(master_tcon->ses->server, 0);
4163 		goto out;
4164 	}
4165 
4166 #ifdef CONFIG_CIFS_DFS_UPCALL
4167 	spin_lock(&master_tcon->tc_lock);
4168 	if (master_tcon->origin_fullpath) {
4169 		spin_unlock(&master_tcon->tc_lock);
4170 		origin_fullpath = dfs_get_path(cifs_sb, cifs_sb->ctx->source);
4171 		if (IS_ERR(origin_fullpath)) {
4172 			tcon = ERR_CAST(origin_fullpath);
4173 			origin_fullpath = NULL;
4174 			cifs_put_smb_ses(ses);
4175 			goto out;
4176 		}
4177 	} else {
4178 		spin_unlock(&master_tcon->tc_lock);
4179 	}
4180 #endif
4181 
4182 	tcon = cifs_get_tcon(ses, ctx);
4183 	if (IS_ERR(tcon)) {
4184 		cifs_put_smb_ses(ses);
4185 		goto out;
4186 	}
4187 
4188 #ifdef CONFIG_CIFS_DFS_UPCALL
4189 	if (origin_fullpath) {
4190 		spin_lock(&tcon->tc_lock);
4191 		tcon->origin_fullpath = origin_fullpath;
4192 		spin_unlock(&tcon->tc_lock);
4193 		origin_fullpath = NULL;
4194 		queue_delayed_work(dfscache_wq, &tcon->dfs_cache_work,
4195 				   dfs_cache_get_ttl() * HZ);
4196 	}
4197 #endif
4198 
4199 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
4200 	if (cap_unix(ses))
4201 		reset_cifs_unix_caps(0, tcon, NULL, ctx);
4202 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
4203 
4204 out:
4205 	kfree(ctx->username);
4206 	kfree_sensitive(ctx->password);
4207 	kfree(origin_fullpath);
4208 	kfree(ctx);
4209 
4210 	return tcon;
4211 }
4212 
4213 struct cifs_tcon *
cifs_sb_master_tcon(struct cifs_sb_info * cifs_sb)4214 cifs_sb_master_tcon(struct cifs_sb_info *cifs_sb)
4215 {
4216 	return tlink_tcon(cifs_sb_master_tlink(cifs_sb));
4217 }
4218 
4219 /* find and return a tlink with given uid */
4220 static struct tcon_link *
tlink_rb_search(struct rb_root * root,kuid_t uid)4221 tlink_rb_search(struct rb_root *root, kuid_t uid)
4222 {
4223 	struct rb_node *node = root->rb_node;
4224 	struct tcon_link *tlink;
4225 
4226 	while (node) {
4227 		tlink = rb_entry(node, struct tcon_link, tl_rbnode);
4228 
4229 		if (uid_gt(tlink->tl_uid, uid))
4230 			node = node->rb_left;
4231 		else if (uid_lt(tlink->tl_uid, uid))
4232 			node = node->rb_right;
4233 		else
4234 			return tlink;
4235 	}
4236 	return NULL;
4237 }
4238 
4239 /* insert a tcon_link into the tree */
4240 static void
tlink_rb_insert(struct rb_root * root,struct tcon_link * new_tlink)4241 tlink_rb_insert(struct rb_root *root, struct tcon_link *new_tlink)
4242 {
4243 	struct rb_node **new = &(root->rb_node), *parent = NULL;
4244 	struct tcon_link *tlink;
4245 
4246 	while (*new) {
4247 		tlink = rb_entry(*new, struct tcon_link, tl_rbnode);
4248 		parent = *new;
4249 
4250 		if (uid_gt(tlink->tl_uid, new_tlink->tl_uid))
4251 			new = &((*new)->rb_left);
4252 		else
4253 			new = &((*new)->rb_right);
4254 	}
4255 
4256 	rb_link_node(&new_tlink->tl_rbnode, parent, new);
4257 	rb_insert_color(&new_tlink->tl_rbnode, root);
4258 }
4259 
4260 /*
4261  * Find or construct an appropriate tcon given a cifs_sb and the fsuid of the
4262  * current task.
4263  *
4264  * If the superblock doesn't refer to a multiuser mount, then just return
4265  * the master tcon for the mount.
4266  *
4267  * First, search the rbtree for an existing tcon for this fsuid. If one
4268  * exists, then check to see if it's pending construction. If it is then wait
4269  * for construction to complete. Once it's no longer pending, check to see if
4270  * it failed and either return an error or retry construction, depending on
4271  * the timeout.
4272  *
4273  * If one doesn't exist then insert a new tcon_link struct into the tree and
4274  * try to construct a new one.
4275  *
4276  * REMEMBER to call cifs_put_tlink() after successful calls to cifs_sb_tlink,
4277  * to avoid refcount issues
4278  */
4279 struct tcon_link *
cifs_sb_tlink(struct cifs_sb_info * cifs_sb)4280 cifs_sb_tlink(struct cifs_sb_info *cifs_sb)
4281 {
4282 	struct tcon_link *tlink, *newtlink;
4283 	kuid_t fsuid = current_fsuid();
4284 	int err;
4285 
4286 	if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER))
4287 		return cifs_get_tlink(cifs_sb_master_tlink(cifs_sb));
4288 
4289 	spin_lock(&cifs_sb->tlink_tree_lock);
4290 	tlink = tlink_rb_search(&cifs_sb->tlink_tree, fsuid);
4291 	if (tlink)
4292 		cifs_get_tlink(tlink);
4293 	spin_unlock(&cifs_sb->tlink_tree_lock);
4294 
4295 	if (tlink == NULL) {
4296 		newtlink = kzalloc(sizeof(*tlink), GFP_KERNEL);
4297 		if (newtlink == NULL)
4298 			return ERR_PTR(-ENOMEM);
4299 		newtlink->tl_uid = fsuid;
4300 		newtlink->tl_tcon = ERR_PTR(-EACCES);
4301 		set_bit(TCON_LINK_PENDING, &newtlink->tl_flags);
4302 		set_bit(TCON_LINK_IN_TREE, &newtlink->tl_flags);
4303 		cifs_get_tlink(newtlink);
4304 
4305 		spin_lock(&cifs_sb->tlink_tree_lock);
4306 		/* was one inserted after previous search? */
4307 		tlink = tlink_rb_search(&cifs_sb->tlink_tree, fsuid);
4308 		if (tlink) {
4309 			cifs_get_tlink(tlink);
4310 			spin_unlock(&cifs_sb->tlink_tree_lock);
4311 			kfree(newtlink);
4312 			goto wait_for_construction;
4313 		}
4314 		tlink = newtlink;
4315 		tlink_rb_insert(&cifs_sb->tlink_tree, tlink);
4316 		spin_unlock(&cifs_sb->tlink_tree_lock);
4317 	} else {
4318 wait_for_construction:
4319 		err = wait_on_bit(&tlink->tl_flags, TCON_LINK_PENDING,
4320 				  TASK_INTERRUPTIBLE);
4321 		if (err) {
4322 			cifs_put_tlink(tlink);
4323 			return ERR_PTR(-ERESTARTSYS);
4324 		}
4325 
4326 		/* if it's good, return it */
4327 		if (!IS_ERR(tlink->tl_tcon))
4328 			return tlink;
4329 
4330 		/* return error if we tried this already recently */
4331 		if (time_before(jiffies, tlink->tl_time + TLINK_ERROR_EXPIRE)) {
4332 			err = PTR_ERR(tlink->tl_tcon);
4333 			cifs_put_tlink(tlink);
4334 			return ERR_PTR(err);
4335 		}
4336 
4337 		if (test_and_set_bit(TCON_LINK_PENDING, &tlink->tl_flags))
4338 			goto wait_for_construction;
4339 	}
4340 
4341 	tlink->tl_tcon = cifs_construct_tcon(cifs_sb, fsuid);
4342 	clear_bit(TCON_LINK_PENDING, &tlink->tl_flags);
4343 	wake_up_bit(&tlink->tl_flags, TCON_LINK_PENDING);
4344 
4345 	if (IS_ERR(tlink->tl_tcon)) {
4346 		err = PTR_ERR(tlink->tl_tcon);
4347 		if (err == -ENOKEY)
4348 			err = -EACCES;
4349 		cifs_put_tlink(tlink);
4350 		return ERR_PTR(err);
4351 	}
4352 
4353 	return tlink;
4354 }
4355 
4356 /*
4357  * periodic workqueue job that scans tcon_tree for a superblock and closes
4358  * out tcons.
4359  */
4360 static void
cifs_prune_tlinks(struct work_struct * work)4361 cifs_prune_tlinks(struct work_struct *work)
4362 {
4363 	struct cifs_sb_info *cifs_sb = container_of(work, struct cifs_sb_info,
4364 						    prune_tlinks.work);
4365 	struct rb_root *root = &cifs_sb->tlink_tree;
4366 	struct rb_node *node;
4367 	struct rb_node *tmp;
4368 	struct tcon_link *tlink;
4369 
4370 	/*
4371 	 * Because we drop the spinlock in the loop in order to put the tlink
4372 	 * it's not guarded against removal of links from the tree. The only
4373 	 * places that remove entries from the tree are this function and
4374 	 * umounts. Because this function is non-reentrant and is canceled
4375 	 * before umount can proceed, this is safe.
4376 	 */
4377 	spin_lock(&cifs_sb->tlink_tree_lock);
4378 	node = rb_first(root);
4379 	while (node != NULL) {
4380 		tmp = node;
4381 		node = rb_next(tmp);
4382 		tlink = rb_entry(tmp, struct tcon_link, tl_rbnode);
4383 
4384 		if (test_bit(TCON_LINK_MASTER, &tlink->tl_flags) ||
4385 		    atomic_read(&tlink->tl_count) != 0 ||
4386 		    time_after(tlink->tl_time + TLINK_IDLE_EXPIRE, jiffies))
4387 			continue;
4388 
4389 		cifs_get_tlink(tlink);
4390 		clear_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
4391 		rb_erase(tmp, root);
4392 
4393 		spin_unlock(&cifs_sb->tlink_tree_lock);
4394 		cifs_put_tlink(tlink);
4395 		spin_lock(&cifs_sb->tlink_tree_lock);
4396 	}
4397 	spin_unlock(&cifs_sb->tlink_tree_lock);
4398 
4399 	queue_delayed_work(cifsiod_wq, &cifs_sb->prune_tlinks,
4400 				TLINK_IDLE_EXPIRE);
4401 }
4402 
4403 #ifndef CONFIG_CIFS_DFS_UPCALL
cifs_tree_connect(const unsigned int xid,struct cifs_tcon * tcon)4404 int cifs_tree_connect(const unsigned int xid, struct cifs_tcon *tcon)
4405 {
4406 	const struct smb_version_operations *ops = tcon->ses->server->ops;
4407 	int rc;
4408 
4409 	/* only send once per connect */
4410 	spin_lock(&tcon->tc_lock);
4411 
4412 	/* if tcon is marked for needing reconnect, update state */
4413 	if (tcon->need_reconnect)
4414 		tcon->status = TID_NEED_TCON;
4415 
4416 	if (tcon->status == TID_GOOD) {
4417 		spin_unlock(&tcon->tc_lock);
4418 		return 0;
4419 	}
4420 
4421 	if (tcon->status != TID_NEW &&
4422 	    tcon->status != TID_NEED_TCON) {
4423 		spin_unlock(&tcon->tc_lock);
4424 		return -EHOSTDOWN;
4425 	}
4426 
4427 	tcon->status = TID_IN_TCON;
4428 	spin_unlock(&tcon->tc_lock);
4429 
4430 	rc = ops->tree_connect(xid, tcon->ses, tcon->tree_name,
4431 			       tcon, tcon->ses->local_nls);
4432 	if (rc) {
4433 		spin_lock(&tcon->tc_lock);
4434 		if (tcon->status == TID_IN_TCON)
4435 			tcon->status = TID_NEED_TCON;
4436 		spin_unlock(&tcon->tc_lock);
4437 	} else {
4438 		spin_lock(&tcon->tc_lock);
4439 		if (tcon->status == TID_IN_TCON)
4440 			tcon->status = TID_GOOD;
4441 		tcon->need_reconnect = false;
4442 		spin_unlock(&tcon->tc_lock);
4443 	}
4444 
4445 	return rc;
4446 }
4447 #endif
4448