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 extern mempool_t *cifs_req_poolp;
56 extern bool disable_legacy_dialects;
57 
58 /* FIXME: should these be tunable? */
59 #define TLINK_ERROR_EXPIRE	(1 * HZ)
60 #define TLINK_IDLE_EXPIRE	(600 * HZ)
61 
62 /* Drop the connection to not overload the server */
63 #define MAX_STATUS_IO_TIMEOUT   5
64 
65 static int ip_connect(struct TCP_Server_Info *server);
66 static int generic_ip_connect(struct TCP_Server_Info *server);
67 static void tlink_rb_insert(struct rb_root *root, struct tcon_link *new_tlink);
68 static void cifs_prune_tlinks(struct work_struct *work);
69 
70 /*
71  * Resolve hostname and set ip addr in tcp ses. Useful for hostnames that may
72  * get their ip addresses changed at some point.
73  *
74  * This should be called with server->srv_mutex held.
75  */
reconn_set_ipaddr_from_hostname(struct TCP_Server_Info * server)76 static int reconn_set_ipaddr_from_hostname(struct TCP_Server_Info *server)
77 {
78 	int rc;
79 	int len;
80 	char *unc;
81 	struct sockaddr_storage ss;
82 
83 	if (!server->hostname)
84 		return -EINVAL;
85 
86 	/* if server hostname isn't populated, there's nothing to do here */
87 	if (server->hostname[0] == '\0')
88 		return 0;
89 
90 	len = strlen(server->hostname) + 3;
91 
92 	unc = kmalloc(len, GFP_KERNEL);
93 	if (!unc) {
94 		cifs_dbg(FYI, "%s: failed to create UNC path\n", __func__);
95 		return -ENOMEM;
96 	}
97 	scnprintf(unc, len, "\\\\%s", server->hostname);
98 
99 	spin_lock(&server->srv_lock);
100 	ss = server->dstaddr;
101 	spin_unlock(&server->srv_lock);
102 
103 	rc = dns_resolve_server_name_to_ip(unc, (struct sockaddr *)&ss, NULL);
104 	kfree(unc);
105 
106 	if (rc < 0) {
107 		cifs_dbg(FYI, "%s: failed to resolve server part of %s to IP: %d\n",
108 			 __func__, server->hostname, rc);
109 	} else {
110 		spin_lock(&server->srv_lock);
111 		memcpy(&server->dstaddr, &ss, sizeof(server->dstaddr));
112 		spin_unlock(&server->srv_lock);
113 		rc = 0;
114 	}
115 
116 	return rc;
117 }
118 
smb2_query_server_interfaces(struct work_struct * work)119 static void smb2_query_server_interfaces(struct work_struct *work)
120 {
121 	int rc;
122 	struct cifs_tcon *tcon = container_of(work,
123 					struct cifs_tcon,
124 					query_interfaces.work);
125 
126 	/*
127 	 * query server network interfaces, in case they change
128 	 */
129 	rc = SMB3_request_interfaces(0, tcon, false);
130 	if (rc) {
131 		if (rc == -EOPNOTSUPP)
132 			return;
133 
134 		cifs_dbg(FYI, "%s: failed to query server interfaces: %d\n",
135 				__func__, rc);
136 	}
137 
138 	queue_delayed_work(cifsiod_wq, &tcon->query_interfaces,
139 			   (SMB_INTERFACE_POLL_INTERVAL * HZ));
140 }
141 
142 /*
143  * Update the tcpStatus for the server.
144  * This is used to signal the cifsd thread to call cifs_reconnect
145  * ONLY cifsd thread should call cifs_reconnect. For any other
146  * thread, use this function
147  *
148  * @server: the tcp ses for which reconnect is needed
149  * @all_channels: if this needs to be done for all channels
150  */
151 void
cifs_signal_cifsd_for_reconnect(struct TCP_Server_Info * server,bool all_channels)152 cifs_signal_cifsd_for_reconnect(struct TCP_Server_Info *server,
153 				bool all_channels)
154 {
155 	struct TCP_Server_Info *pserver;
156 	struct cifs_ses *ses;
157 	int i;
158 
159 	/* If server is a channel, select the primary channel */
160 	pserver = SERVER_IS_CHAN(server) ? server->primary_server : server;
161 
162 	/* if we need to signal just this channel */
163 	if (!all_channels) {
164 		spin_lock(&server->srv_lock);
165 		if (server->tcpStatus != CifsExiting)
166 			server->tcpStatus = CifsNeedReconnect;
167 		spin_unlock(&server->srv_lock);
168 		return;
169 	}
170 
171 	spin_lock(&cifs_tcp_ses_lock);
172 	list_for_each_entry(ses, &pserver->smb_ses_list, smb_ses_list) {
173 		spin_lock(&ses->chan_lock);
174 		for (i = 0; i < ses->chan_count; i++) {
175 			if (!ses->chans[i].server)
176 				continue;
177 
178 			spin_lock(&ses->chans[i].server->srv_lock);
179 			if (ses->chans[i].server->tcpStatus != CifsExiting)
180 				ses->chans[i].server->tcpStatus = CifsNeedReconnect;
181 			spin_unlock(&ses->chans[i].server->srv_lock);
182 		}
183 		spin_unlock(&ses->chan_lock);
184 	}
185 	spin_unlock(&cifs_tcp_ses_lock);
186 }
187 
188 /*
189  * Mark all sessions and tcons for reconnect.
190  * IMPORTANT: make sure that this gets called only from
191  * cifsd thread. For any other thread, use
192  * cifs_signal_cifsd_for_reconnect
193  *
194  * @server: the tcp ses for which reconnect is needed
195  * @server needs to be previously set to CifsNeedReconnect.
196  * @mark_smb_session: whether even sessions need to be marked
197  */
198 void
cifs_mark_tcp_ses_conns_for_reconnect(struct TCP_Server_Info * server,bool mark_smb_session)199 cifs_mark_tcp_ses_conns_for_reconnect(struct TCP_Server_Info *server,
200 				      bool mark_smb_session)
201 {
202 	struct TCP_Server_Info *pserver;
203 	struct cifs_ses *ses, *nses;
204 	struct cifs_tcon *tcon;
205 
206 	/*
207 	 * before reconnecting the tcp session, mark the smb session (uid) and the tid bad so they
208 	 * are not used until reconnected.
209 	 */
210 	cifs_dbg(FYI, "%s: marking necessary sessions and tcons for reconnect\n", __func__);
211 
212 	/* If server is a channel, select the primary channel */
213 	pserver = SERVER_IS_CHAN(server) ? server->primary_server : server;
214 
215 	/*
216 	 * if the server has been marked for termination, there is a
217 	 * chance that the remaining channels all need reconnect. To be
218 	 * on the safer side, mark the session and trees for reconnect
219 	 * for this scenario. This might cause a few redundant session
220 	 * setup and tree connect requests, but it is better than not doing
221 	 * a tree connect when needed, and all following requests failing
222 	 */
223 	if (server->terminate) {
224 		mark_smb_session = true;
225 		server = pserver;
226 	}
227 
228 	spin_lock(&cifs_tcp_ses_lock);
229 	list_for_each_entry_safe(ses, nses, &pserver->smb_ses_list, smb_ses_list) {
230 		/* check if iface is still active */
231 		spin_lock(&ses->chan_lock);
232 		if (cifs_ses_get_chan_index(ses, server) ==
233 		    CIFS_INVAL_CHAN_INDEX) {
234 			spin_unlock(&ses->chan_lock);
235 			continue;
236 		}
237 
238 		if (!cifs_chan_is_iface_active(ses, server)) {
239 			spin_unlock(&ses->chan_lock);
240 			cifs_chan_update_iface(ses, server);
241 			spin_lock(&ses->chan_lock);
242 		}
243 
244 		if (!mark_smb_session && cifs_chan_needs_reconnect(ses, server)) {
245 			spin_unlock(&ses->chan_lock);
246 			continue;
247 		}
248 
249 		if (mark_smb_session)
250 			CIFS_SET_ALL_CHANS_NEED_RECONNECT(ses);
251 		else
252 			cifs_chan_set_need_reconnect(ses, server);
253 
254 		cifs_dbg(FYI, "%s: channel connect bitmap: 0x%lx\n",
255 			 __func__, ses->chans_need_reconnect);
256 
257 		/* If all channels need reconnect, then tcon needs reconnect */
258 		if (!mark_smb_session && !CIFS_ALL_CHANS_NEED_RECONNECT(ses)) {
259 			spin_unlock(&ses->chan_lock);
260 			continue;
261 		}
262 		spin_unlock(&ses->chan_lock);
263 
264 		spin_lock(&ses->ses_lock);
265 		ses->ses_status = SES_NEED_RECON;
266 		spin_unlock(&ses->ses_lock);
267 
268 		list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
269 			tcon->need_reconnect = true;
270 			spin_lock(&tcon->tc_lock);
271 			tcon->status = TID_NEED_RECON;
272 			spin_unlock(&tcon->tc_lock);
273 
274 			cancel_delayed_work(&tcon->query_interfaces);
275 		}
276 		if (ses->tcon_ipc) {
277 			ses->tcon_ipc->need_reconnect = true;
278 			spin_lock(&ses->tcon_ipc->tc_lock);
279 			ses->tcon_ipc->status = TID_NEED_RECON;
280 			spin_unlock(&ses->tcon_ipc->tc_lock);
281 		}
282 	}
283 	spin_unlock(&cifs_tcp_ses_lock);
284 }
285 
286 static void
cifs_abort_connection(struct TCP_Server_Info * server)287 cifs_abort_connection(struct TCP_Server_Info *server)
288 {
289 	struct mid_q_entry *mid, *nmid;
290 	struct list_head retry_list;
291 
292 	server->maxBuf = 0;
293 	server->max_read = 0;
294 
295 	/* do not want to be sending data on a socket we are freeing */
296 	cifs_dbg(FYI, "%s: tearing down socket\n", __func__);
297 	cifs_server_lock(server);
298 	if (server->ssocket) {
299 		cifs_dbg(FYI, "State: 0x%x Flags: 0x%lx\n", server->ssocket->state,
300 			 server->ssocket->flags);
301 		kernel_sock_shutdown(server->ssocket, SHUT_WR);
302 		cifs_dbg(FYI, "Post shutdown state: 0x%x Flags: 0x%lx\n", server->ssocket->state,
303 			 server->ssocket->flags);
304 		sock_release(server->ssocket);
305 		server->ssocket = NULL;
306 	}
307 	server->sequence_number = 0;
308 	server->session_estab = false;
309 	kfree_sensitive(server->session_key.response);
310 	server->session_key.response = NULL;
311 	server->session_key.len = 0;
312 	server->lstrp = jiffies;
313 
314 	/* mark submitted MIDs for retry and issue callback */
315 	INIT_LIST_HEAD(&retry_list);
316 	cifs_dbg(FYI, "%s: moving mids to private list\n", __func__);
317 	spin_lock(&server->mid_lock);
318 	list_for_each_entry_safe(mid, nmid, &server->pending_mid_q, qhead) {
319 		kref_get(&mid->refcount);
320 		if (mid->mid_state == MID_REQUEST_SUBMITTED)
321 			mid->mid_state = MID_RETRY_NEEDED;
322 		list_move(&mid->qhead, &retry_list);
323 		mid->mid_flags |= MID_DELETED;
324 	}
325 	spin_unlock(&server->mid_lock);
326 	cifs_server_unlock(server);
327 
328 	cifs_dbg(FYI, "%s: issuing mid callbacks\n", __func__);
329 	list_for_each_entry_safe(mid, nmid, &retry_list, qhead) {
330 		list_del_init(&mid->qhead);
331 		mid->callback(mid);
332 		release_mid(mid);
333 	}
334 
335 	if (cifs_rdma_enabled(server)) {
336 		cifs_server_lock(server);
337 		smbd_destroy(server);
338 		cifs_server_unlock(server);
339 	}
340 }
341 
cifs_tcp_ses_needs_reconnect(struct TCP_Server_Info * server,int num_targets)342 static bool cifs_tcp_ses_needs_reconnect(struct TCP_Server_Info *server, int num_targets)
343 {
344 	spin_lock(&server->srv_lock);
345 	server->nr_targets = num_targets;
346 	if (server->tcpStatus == CifsExiting) {
347 		/* the demux thread will exit normally next time through the loop */
348 		spin_unlock(&server->srv_lock);
349 		wake_up(&server->response_q);
350 		return false;
351 	}
352 
353 	cifs_dbg(FYI, "Mark tcp session as need reconnect\n");
354 	trace_smb3_reconnect(server->CurrentMid, server->conn_id,
355 			     server->hostname);
356 	server->tcpStatus = CifsNeedReconnect;
357 
358 	spin_unlock(&server->srv_lock);
359 	return true;
360 }
361 
362 /*
363  * cifs tcp session reconnection
364  *
365  * mark tcp session as reconnecting so temporarily locked
366  * mark all smb sessions as reconnecting for tcp session
367  * reconnect tcp session
368  * wake up waiters on reconnection? - (not needed currently)
369  *
370  * if mark_smb_session is passed as true, unconditionally mark
371  * the smb session (and tcon) for reconnect as well. This value
372  * doesn't really matter for non-multichannel scenario.
373  *
374  */
__cifs_reconnect(struct TCP_Server_Info * server,bool mark_smb_session)375 static int __cifs_reconnect(struct TCP_Server_Info *server,
376 			    bool mark_smb_session)
377 {
378 	int rc = 0;
379 
380 	if (!cifs_tcp_ses_needs_reconnect(server, 1))
381 		return 0;
382 
383 	cifs_mark_tcp_ses_conns_for_reconnect(server, mark_smb_session);
384 
385 	cifs_abort_connection(server);
386 
387 	do {
388 		try_to_freeze();
389 		cifs_server_lock(server);
390 
391 		if (!cifs_swn_set_server_dstaddr(server)) {
392 			/* resolve the hostname again to make sure that IP address is up-to-date */
393 			rc = reconn_set_ipaddr_from_hostname(server);
394 			cifs_dbg(FYI, "%s: reconn_set_ipaddr_from_hostname: rc=%d\n", __func__, rc);
395 		}
396 
397 		if (cifs_rdma_enabled(server))
398 			rc = smbd_reconnect(server);
399 		else
400 			rc = generic_ip_connect(server);
401 		if (rc) {
402 			cifs_server_unlock(server);
403 			cifs_dbg(FYI, "%s: reconnect error %d\n", __func__, rc);
404 			msleep(3000);
405 		} else {
406 			atomic_inc(&tcpSesReconnectCount);
407 			set_credits(server, 1);
408 			spin_lock(&server->srv_lock);
409 			if (server->tcpStatus != CifsExiting)
410 				server->tcpStatus = CifsNeedNegotiate;
411 			spin_unlock(&server->srv_lock);
412 			cifs_swn_reset_server_dstaddr(server);
413 			cifs_server_unlock(server);
414 			mod_delayed_work(cifsiod_wq, &server->reconnect, 0);
415 		}
416 	} while (server->tcpStatus == CifsNeedReconnect);
417 
418 	spin_lock(&server->srv_lock);
419 	if (server->tcpStatus == CifsNeedNegotiate)
420 		mod_delayed_work(cifsiod_wq, &server->echo, 0);
421 	spin_unlock(&server->srv_lock);
422 
423 	wake_up(&server->response_q);
424 	return rc;
425 }
426 
427 #ifdef CONFIG_CIFS_DFS_UPCALL
__reconnect_target_unlocked(struct TCP_Server_Info * server,const char * target)428 static int __reconnect_target_unlocked(struct TCP_Server_Info *server, const char *target)
429 {
430 	int rc;
431 	char *hostname;
432 
433 	if (!cifs_swn_set_server_dstaddr(server)) {
434 		if (server->hostname != target) {
435 			hostname = extract_hostname(target);
436 			if (!IS_ERR(hostname)) {
437 				spin_lock(&server->srv_lock);
438 				kfree(server->hostname);
439 				server->hostname = hostname;
440 				spin_unlock(&server->srv_lock);
441 			} else {
442 				cifs_dbg(FYI, "%s: couldn't extract hostname or address from dfs target: %ld\n",
443 					 __func__, PTR_ERR(hostname));
444 				cifs_dbg(FYI, "%s: default to last target server: %s\n", __func__,
445 					 server->hostname);
446 			}
447 		}
448 		/* resolve the hostname again to make sure that IP address is up-to-date. */
449 		rc = reconn_set_ipaddr_from_hostname(server);
450 		cifs_dbg(FYI, "%s: reconn_set_ipaddr_from_hostname: rc=%d\n", __func__, rc);
451 	}
452 	/* Reconnect the socket */
453 	if (cifs_rdma_enabled(server))
454 		rc = smbd_reconnect(server);
455 	else
456 		rc = generic_ip_connect(server);
457 
458 	return rc;
459 }
460 
reconnect_target_unlocked(struct TCP_Server_Info * server,struct dfs_cache_tgt_list * tl,struct dfs_cache_tgt_iterator ** target_hint)461 static int reconnect_target_unlocked(struct TCP_Server_Info *server, struct dfs_cache_tgt_list *tl,
462 				     struct dfs_cache_tgt_iterator **target_hint)
463 {
464 	int rc;
465 	struct dfs_cache_tgt_iterator *tit;
466 
467 	*target_hint = NULL;
468 
469 	/* If dfs target list is empty, then reconnect to last server */
470 	tit = dfs_cache_get_tgt_iterator(tl);
471 	if (!tit)
472 		return __reconnect_target_unlocked(server, server->hostname);
473 
474 	/* Otherwise, try every dfs target in @tl */
475 	for (; tit; tit = dfs_cache_get_next_tgt(tl, tit)) {
476 		rc = __reconnect_target_unlocked(server, dfs_cache_get_tgt_name(tit));
477 		if (!rc) {
478 			*target_hint = tit;
479 			break;
480 		}
481 	}
482 	return rc;
483 }
484 
reconnect_dfs_server(struct TCP_Server_Info * server)485 static int reconnect_dfs_server(struct TCP_Server_Info *server)
486 {
487 	struct dfs_cache_tgt_iterator *target_hint = NULL;
488 	DFS_CACHE_TGT_LIST(tl);
489 	int num_targets = 0;
490 	int rc = 0;
491 
492 	/*
493 	 * Determine the number of dfs targets the referral path in @cifs_sb resolves to.
494 	 *
495 	 * smb2_reconnect() needs to know how long it should wait based upon the number of dfs
496 	 * targets (server->nr_targets).  It's also possible that the cached referral was cleared
497 	 * through /proc/fs/cifs/dfscache or the target list is empty due to server settings after
498 	 * refreshing the referral, so, in this case, default it to 1.
499 	 */
500 	mutex_lock(&server->refpath_lock);
501 	if (!dfs_cache_noreq_find(server->leaf_fullpath + 1, NULL, &tl))
502 		num_targets = dfs_cache_get_nr_tgts(&tl);
503 	mutex_unlock(&server->refpath_lock);
504 	if (!num_targets)
505 		num_targets = 1;
506 
507 	if (!cifs_tcp_ses_needs_reconnect(server, num_targets))
508 		return 0;
509 
510 	/*
511 	 * Unconditionally mark all sessions & tcons for reconnect as we might be connecting to a
512 	 * different server or share during failover.  It could be improved by adding some logic to
513 	 * only do that in case it connects to a different server or share, though.
514 	 */
515 	cifs_mark_tcp_ses_conns_for_reconnect(server, true);
516 
517 	cifs_abort_connection(server);
518 
519 	do {
520 		try_to_freeze();
521 		cifs_server_lock(server);
522 
523 		rc = reconnect_target_unlocked(server, &tl, &target_hint);
524 		if (rc) {
525 			/* Failed to reconnect socket */
526 			cifs_server_unlock(server);
527 			cifs_dbg(FYI, "%s: reconnect error %d\n", __func__, rc);
528 			msleep(3000);
529 			continue;
530 		}
531 		/*
532 		 * Socket was created.  Update tcp session status to CifsNeedNegotiate so that a
533 		 * process waiting for reconnect will know it needs to re-establish session and tcon
534 		 * through the reconnected target server.
535 		 */
536 		atomic_inc(&tcpSesReconnectCount);
537 		set_credits(server, 1);
538 		spin_lock(&server->srv_lock);
539 		if (server->tcpStatus != CifsExiting)
540 			server->tcpStatus = CifsNeedNegotiate;
541 		spin_unlock(&server->srv_lock);
542 		cifs_swn_reset_server_dstaddr(server);
543 		cifs_server_unlock(server);
544 		mod_delayed_work(cifsiod_wq, &server->reconnect, 0);
545 	} while (server->tcpStatus == CifsNeedReconnect);
546 
547 	mutex_lock(&server->refpath_lock);
548 	dfs_cache_noreq_update_tgthint(server->leaf_fullpath + 1, target_hint);
549 	mutex_unlock(&server->refpath_lock);
550 	dfs_cache_free_tgts(&tl);
551 
552 	/* Need to set up echo worker again once connection has been established */
553 	spin_lock(&server->srv_lock);
554 	if (server->tcpStatus == CifsNeedNegotiate)
555 		mod_delayed_work(cifsiod_wq, &server->echo, 0);
556 	spin_unlock(&server->srv_lock);
557 
558 	wake_up(&server->response_q);
559 	return rc;
560 }
561 
cifs_reconnect(struct TCP_Server_Info * server,bool mark_smb_session)562 int cifs_reconnect(struct TCP_Server_Info *server, bool mark_smb_session)
563 {
564 	mutex_lock(&server->refpath_lock);
565 	if (!server->leaf_fullpath) {
566 		mutex_unlock(&server->refpath_lock);
567 		return __cifs_reconnect(server, mark_smb_session);
568 	}
569 	mutex_unlock(&server->refpath_lock);
570 
571 	return reconnect_dfs_server(server);
572 }
573 #else
cifs_reconnect(struct TCP_Server_Info * server,bool mark_smb_session)574 int cifs_reconnect(struct TCP_Server_Info *server, bool mark_smb_session)
575 {
576 	return __cifs_reconnect(server, mark_smb_session);
577 }
578 #endif
579 
580 static void
cifs_echo_request(struct work_struct * work)581 cifs_echo_request(struct work_struct *work)
582 {
583 	int rc;
584 	struct TCP_Server_Info *server = container_of(work,
585 					struct TCP_Server_Info, echo.work);
586 
587 	/*
588 	 * We cannot send an echo if it is disabled.
589 	 * Also, no need to ping if we got a response recently.
590 	 */
591 
592 	if (server->tcpStatus == CifsNeedReconnect ||
593 	    server->tcpStatus == CifsExiting ||
594 	    server->tcpStatus == CifsNew ||
595 	    (server->ops->can_echo && !server->ops->can_echo(server)) ||
596 	    time_before(jiffies, server->lstrp + server->echo_interval - HZ))
597 		goto requeue_echo;
598 
599 	rc = server->ops->echo ? server->ops->echo(server) : -ENOSYS;
600 	cifs_server_dbg(FYI, "send echo request: rc = %d\n", rc);
601 
602 	/* Check witness registrations */
603 	cifs_swn_check();
604 
605 requeue_echo:
606 	queue_delayed_work(cifsiod_wq, &server->echo, server->echo_interval);
607 }
608 
609 static bool
allocate_buffers(struct TCP_Server_Info * server)610 allocate_buffers(struct TCP_Server_Info *server)
611 {
612 	if (!server->bigbuf) {
613 		server->bigbuf = (char *)cifs_buf_get();
614 		if (!server->bigbuf) {
615 			cifs_server_dbg(VFS, "No memory for large SMB response\n");
616 			msleep(3000);
617 			/* retry will check if exiting */
618 			return false;
619 		}
620 	} else if (server->large_buf) {
621 		/* we are reusing a dirty large buf, clear its start */
622 		memset(server->bigbuf, 0, HEADER_SIZE(server));
623 	}
624 
625 	if (!server->smallbuf) {
626 		server->smallbuf = (char *)cifs_small_buf_get();
627 		if (!server->smallbuf) {
628 			cifs_server_dbg(VFS, "No memory for SMB response\n");
629 			msleep(1000);
630 			/* retry will check if exiting */
631 			return false;
632 		}
633 		/* beginning of smb buffer is cleared in our buf_get */
634 	} else {
635 		/* if existing small buf clear beginning */
636 		memset(server->smallbuf, 0, HEADER_SIZE(server));
637 	}
638 
639 	return true;
640 }
641 
642 static bool
server_unresponsive(struct TCP_Server_Info * server)643 server_unresponsive(struct TCP_Server_Info *server)
644 {
645 	/*
646 	 * We need to wait 3 echo intervals to make sure we handle such
647 	 * situations right:
648 	 * 1s  client sends a normal SMB request
649 	 * 2s  client gets a response
650 	 * 30s echo workqueue job pops, and decides we got a response recently
651 	 *     and don't need to send another
652 	 * ...
653 	 * 65s kernel_recvmsg times out, and we see that we haven't gotten
654 	 *     a response in >60s.
655 	 */
656 	spin_lock(&server->srv_lock);
657 	if ((server->tcpStatus == CifsGood ||
658 	    server->tcpStatus == CifsNeedNegotiate) &&
659 	    (!server->ops->can_echo || server->ops->can_echo(server)) &&
660 	    time_after(jiffies, server->lstrp + 3 * server->echo_interval)) {
661 		spin_unlock(&server->srv_lock);
662 		cifs_server_dbg(VFS, "has not responded in %lu seconds. Reconnecting...\n",
663 			 (3 * server->echo_interval) / HZ);
664 		cifs_reconnect(server, false);
665 		return true;
666 	}
667 	spin_unlock(&server->srv_lock);
668 
669 	return false;
670 }
671 
672 static inline bool
zero_credits(struct TCP_Server_Info * server)673 zero_credits(struct TCP_Server_Info *server)
674 {
675 	int val;
676 
677 	spin_lock(&server->req_lock);
678 	val = server->credits + server->echo_credits + server->oplock_credits;
679 	if (server->in_flight == 0 && val == 0) {
680 		spin_unlock(&server->req_lock);
681 		return true;
682 	}
683 	spin_unlock(&server->req_lock);
684 	return false;
685 }
686 
687 static int
cifs_readv_from_socket(struct TCP_Server_Info * server,struct msghdr * smb_msg)688 cifs_readv_from_socket(struct TCP_Server_Info *server, struct msghdr *smb_msg)
689 {
690 	int length = 0;
691 	int total_read;
692 
693 	for (total_read = 0; msg_data_left(smb_msg); total_read += length) {
694 		try_to_freeze();
695 
696 		/* reconnect if no credits and no requests in flight */
697 		if (zero_credits(server)) {
698 			cifs_reconnect(server, false);
699 			return -ECONNABORTED;
700 		}
701 
702 		if (server_unresponsive(server))
703 			return -ECONNABORTED;
704 		if (cifs_rdma_enabled(server) && server->smbd_conn)
705 			length = smbd_recv(server->smbd_conn, smb_msg);
706 		else
707 			length = sock_recvmsg(server->ssocket, smb_msg, 0);
708 
709 		spin_lock(&server->srv_lock);
710 		if (server->tcpStatus == CifsExiting) {
711 			spin_unlock(&server->srv_lock);
712 			return -ESHUTDOWN;
713 		}
714 
715 		if (server->tcpStatus == CifsNeedReconnect) {
716 			spin_unlock(&server->srv_lock);
717 			cifs_reconnect(server, false);
718 			return -ECONNABORTED;
719 		}
720 		spin_unlock(&server->srv_lock);
721 
722 		if (length == -ERESTARTSYS ||
723 		    length == -EAGAIN ||
724 		    length == -EINTR) {
725 			/*
726 			 * Minimum sleep to prevent looping, allowing socket
727 			 * to clear and app threads to set tcpStatus
728 			 * CifsNeedReconnect if server hung.
729 			 */
730 			usleep_range(1000, 2000);
731 			length = 0;
732 			continue;
733 		}
734 
735 		if (length <= 0) {
736 			cifs_dbg(FYI, "Received no data or error: %d\n", length);
737 			cifs_reconnect(server, false);
738 			return -ECONNABORTED;
739 		}
740 	}
741 	return total_read;
742 }
743 
744 int
cifs_read_from_socket(struct TCP_Server_Info * server,char * buf,unsigned int to_read)745 cifs_read_from_socket(struct TCP_Server_Info *server, char *buf,
746 		      unsigned int to_read)
747 {
748 	struct msghdr smb_msg = {};
749 	struct kvec iov = {.iov_base = buf, .iov_len = to_read};
750 	iov_iter_kvec(&smb_msg.msg_iter, ITER_DEST, &iov, 1, to_read);
751 
752 	return cifs_readv_from_socket(server, &smb_msg);
753 }
754 
755 ssize_t
cifs_discard_from_socket(struct TCP_Server_Info * server,size_t to_read)756 cifs_discard_from_socket(struct TCP_Server_Info *server, size_t to_read)
757 {
758 	struct msghdr smb_msg = {};
759 
760 	/*
761 	 *  iov_iter_discard already sets smb_msg.type and count and iov_offset
762 	 *  and cifs_readv_from_socket sets msg_control and msg_controllen
763 	 *  so little to initialize in struct msghdr
764 	 */
765 	iov_iter_discard(&smb_msg.msg_iter, ITER_DEST, to_read);
766 
767 	return cifs_readv_from_socket(server, &smb_msg);
768 }
769 
770 int
cifs_read_page_from_socket(struct TCP_Server_Info * server,struct page * page,unsigned int page_offset,unsigned int to_read)771 cifs_read_page_from_socket(struct TCP_Server_Info *server, struct page *page,
772 	unsigned int page_offset, unsigned int to_read)
773 {
774 	struct msghdr smb_msg = {};
775 	struct bio_vec bv;
776 
777 	bvec_set_page(&bv, page, to_read, page_offset);
778 	iov_iter_bvec(&smb_msg.msg_iter, ITER_DEST, &bv, 1, to_read);
779 	return cifs_readv_from_socket(server, &smb_msg);
780 }
781 
782 int
cifs_read_iter_from_socket(struct TCP_Server_Info * server,struct iov_iter * iter,unsigned int to_read)783 cifs_read_iter_from_socket(struct TCP_Server_Info *server, struct iov_iter *iter,
784 			   unsigned int to_read)
785 {
786 	struct msghdr smb_msg = { .msg_iter = *iter };
787 	int ret;
788 
789 	iov_iter_truncate(&smb_msg.msg_iter, to_read);
790 	ret = cifs_readv_from_socket(server, &smb_msg);
791 	if (ret > 0)
792 		iov_iter_advance(iter, ret);
793 	return ret;
794 }
795 
796 static bool
is_smb_response(struct TCP_Server_Info * server,unsigned char type)797 is_smb_response(struct TCP_Server_Info *server, unsigned char type)
798 {
799 	/*
800 	 * The first byte big endian of the length field,
801 	 * is actually not part of the length but the type
802 	 * with the most common, zero, as regular data.
803 	 */
804 	switch (type) {
805 	case RFC1002_SESSION_MESSAGE:
806 		/* Regular SMB response */
807 		return true;
808 	case RFC1002_SESSION_KEEP_ALIVE:
809 		cifs_dbg(FYI, "RFC 1002 session keep alive\n");
810 		break;
811 	case RFC1002_POSITIVE_SESSION_RESPONSE:
812 		cifs_dbg(FYI, "RFC 1002 positive session response\n");
813 		break;
814 	case RFC1002_NEGATIVE_SESSION_RESPONSE:
815 		/*
816 		 * We get this from Windows 98 instead of an error on
817 		 * SMB negprot response.
818 		 */
819 		cifs_dbg(FYI, "RFC 1002 negative session response\n");
820 		/* give server a second to clean up */
821 		msleep(1000);
822 		/*
823 		 * Always try 445 first on reconnect since we get NACK
824 		 * on some if we ever connected to port 139 (the NACK
825 		 * is since we do not begin with RFC1001 session
826 		 * initialize frame).
827 		 */
828 		cifs_set_port((struct sockaddr *)&server->dstaddr, CIFS_PORT);
829 		cifs_reconnect(server, true);
830 		break;
831 	default:
832 		cifs_server_dbg(VFS, "RFC 1002 unknown response type 0x%x\n", type);
833 		cifs_reconnect(server, true);
834 	}
835 
836 	return false;
837 }
838 
839 void
dequeue_mid(struct mid_q_entry * mid,bool malformed)840 dequeue_mid(struct mid_q_entry *mid, bool malformed)
841 {
842 #ifdef CONFIG_CIFS_STATS2
843 	mid->when_received = jiffies;
844 #endif
845 	spin_lock(&mid->server->mid_lock);
846 	if (!malformed)
847 		mid->mid_state = MID_RESPONSE_RECEIVED;
848 	else
849 		mid->mid_state = MID_RESPONSE_MALFORMED;
850 	/*
851 	 * Trying to handle/dequeue a mid after the send_recv()
852 	 * function has finished processing it is a bug.
853 	 */
854 	if (mid->mid_flags & MID_DELETED) {
855 		spin_unlock(&mid->server->mid_lock);
856 		pr_warn_once("trying to dequeue a deleted mid\n");
857 	} else {
858 		list_del_init(&mid->qhead);
859 		mid->mid_flags |= MID_DELETED;
860 		spin_unlock(&mid->server->mid_lock);
861 	}
862 }
863 
864 static unsigned int
smb2_get_credits_from_hdr(char * buffer,struct TCP_Server_Info * server)865 smb2_get_credits_from_hdr(char *buffer, struct TCP_Server_Info *server)
866 {
867 	struct smb2_hdr *shdr = (struct smb2_hdr *)buffer;
868 
869 	/*
870 	 * SMB1 does not use credits.
871 	 */
872 	if (is_smb1(server))
873 		return 0;
874 
875 	return le16_to_cpu(shdr->CreditRequest);
876 }
877 
878 static void
handle_mid(struct mid_q_entry * mid,struct TCP_Server_Info * server,char * buf,int malformed)879 handle_mid(struct mid_q_entry *mid, struct TCP_Server_Info *server,
880 	   char *buf, int malformed)
881 {
882 	if (server->ops->check_trans2 &&
883 	    server->ops->check_trans2(mid, server, buf, malformed))
884 		return;
885 	mid->credits_received = smb2_get_credits_from_hdr(buf, server);
886 	mid->resp_buf = buf;
887 	mid->large_buf = server->large_buf;
888 	/* Was previous buf put in mpx struct for multi-rsp? */
889 	if (!mid->multiRsp) {
890 		/* smb buffer will be freed by user thread */
891 		if (server->large_buf)
892 			server->bigbuf = NULL;
893 		else
894 			server->smallbuf = NULL;
895 	}
896 	dequeue_mid(mid, malformed);
897 }
898 
899 int
cifs_enable_signing(struct TCP_Server_Info * server,bool mnt_sign_required)900 cifs_enable_signing(struct TCP_Server_Info *server, bool mnt_sign_required)
901 {
902 	bool srv_sign_required = server->sec_mode & server->vals->signing_required;
903 	bool srv_sign_enabled = server->sec_mode & server->vals->signing_enabled;
904 	bool mnt_sign_enabled;
905 
906 	/*
907 	 * Is signing required by mnt options? If not then check
908 	 * global_secflags to see if it is there.
909 	 */
910 	if (!mnt_sign_required)
911 		mnt_sign_required = ((global_secflags & CIFSSEC_MUST_SIGN) ==
912 						CIFSSEC_MUST_SIGN);
913 
914 	/*
915 	 * If signing is required then it's automatically enabled too,
916 	 * otherwise, check to see if the secflags allow it.
917 	 */
918 	mnt_sign_enabled = mnt_sign_required ? mnt_sign_required :
919 				(global_secflags & CIFSSEC_MAY_SIGN);
920 
921 	/* If server requires signing, does client allow it? */
922 	if (srv_sign_required) {
923 		if (!mnt_sign_enabled) {
924 			cifs_dbg(VFS, "Server requires signing, but it's disabled in SecurityFlags!\n");
925 			return -EOPNOTSUPP;
926 		}
927 		server->sign = true;
928 	}
929 
930 	/* If client requires signing, does server allow it? */
931 	if (mnt_sign_required) {
932 		if (!srv_sign_enabled) {
933 			cifs_dbg(VFS, "Server does not support signing!\n");
934 			return -EOPNOTSUPP;
935 		}
936 		server->sign = true;
937 	}
938 
939 	if (cifs_rdma_enabled(server) && server->sign)
940 		cifs_dbg(VFS, "Signing is enabled, and RDMA read/write will be disabled\n");
941 
942 	return 0;
943 }
944 
945 static noinline_for_stack void
clean_demultiplex_info(struct TCP_Server_Info * server)946 clean_demultiplex_info(struct TCP_Server_Info *server)
947 {
948 	int length;
949 
950 	/* take it off the list, if it's not already */
951 	spin_lock(&server->srv_lock);
952 	list_del_init(&server->tcp_ses_list);
953 	spin_unlock(&server->srv_lock);
954 
955 	cancel_delayed_work_sync(&server->echo);
956 
957 	spin_lock(&server->srv_lock);
958 	server->tcpStatus = CifsExiting;
959 	spin_unlock(&server->srv_lock);
960 	wake_up_all(&server->response_q);
961 
962 	/* check if we have blocked requests that need to free */
963 	spin_lock(&server->req_lock);
964 	if (server->credits <= 0)
965 		server->credits = 1;
966 	spin_unlock(&server->req_lock);
967 	/*
968 	 * Although there should not be any requests blocked on this queue it
969 	 * can not hurt to be paranoid and try to wake up requests that may
970 	 * haven been blocked when more than 50 at time were on the wire to the
971 	 * same server - they now will see the session is in exit state and get
972 	 * out of SendReceive.
973 	 */
974 	wake_up_all(&server->request_q);
975 	/* give those requests time to exit */
976 	msleep(125);
977 	if (cifs_rdma_enabled(server))
978 		smbd_destroy(server);
979 	if (server->ssocket) {
980 		sock_release(server->ssocket);
981 		server->ssocket = NULL;
982 	}
983 
984 	if (!list_empty(&server->pending_mid_q)) {
985 		struct list_head dispose_list;
986 		struct mid_q_entry *mid_entry;
987 		struct list_head *tmp, *tmp2;
988 
989 		INIT_LIST_HEAD(&dispose_list);
990 		spin_lock(&server->mid_lock);
991 		list_for_each_safe(tmp, tmp2, &server->pending_mid_q) {
992 			mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
993 			cifs_dbg(FYI, "Clearing mid %llu\n", mid_entry->mid);
994 			kref_get(&mid_entry->refcount);
995 			mid_entry->mid_state = MID_SHUTDOWN;
996 			list_move(&mid_entry->qhead, &dispose_list);
997 			mid_entry->mid_flags |= MID_DELETED;
998 		}
999 		spin_unlock(&server->mid_lock);
1000 
1001 		/* now walk dispose list and issue callbacks */
1002 		list_for_each_safe(tmp, tmp2, &dispose_list) {
1003 			mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
1004 			cifs_dbg(FYI, "Callback mid %llu\n", mid_entry->mid);
1005 			list_del_init(&mid_entry->qhead);
1006 			mid_entry->callback(mid_entry);
1007 			release_mid(mid_entry);
1008 		}
1009 		/* 1/8th of sec is more than enough time for them to exit */
1010 		msleep(125);
1011 	}
1012 
1013 	if (!list_empty(&server->pending_mid_q)) {
1014 		/*
1015 		 * mpx threads have not exited yet give them at least the smb
1016 		 * send timeout time for long ops.
1017 		 *
1018 		 * Due to delays on oplock break requests, we need to wait at
1019 		 * least 45 seconds before giving up on a request getting a
1020 		 * response and going ahead and killing cifsd.
1021 		 */
1022 		cifs_dbg(FYI, "Wait for exit from demultiplex thread\n");
1023 		msleep(46000);
1024 		/*
1025 		 * If threads still have not exited they are probably never
1026 		 * coming home not much else we can do but free the memory.
1027 		 */
1028 	}
1029 
1030 	kfree(server->leaf_fullpath);
1031 	kfree(server);
1032 
1033 	length = atomic_dec_return(&tcpSesAllocCount);
1034 	if (length > 0)
1035 		mempool_resize(cifs_req_poolp, length + cifs_min_rcv);
1036 }
1037 
1038 static int
standard_receive3(struct TCP_Server_Info * server,struct mid_q_entry * mid)1039 standard_receive3(struct TCP_Server_Info *server, struct mid_q_entry *mid)
1040 {
1041 	int length;
1042 	char *buf = server->smallbuf;
1043 	unsigned int pdu_length = server->pdu_size;
1044 
1045 	/* make sure this will fit in a large buffer */
1046 	if (pdu_length > CIFSMaxBufSize + MAX_HEADER_SIZE(server) -
1047 	    HEADER_PREAMBLE_SIZE(server)) {
1048 		cifs_server_dbg(VFS, "SMB response too long (%u bytes)\n", pdu_length);
1049 		cifs_reconnect(server, true);
1050 		return -ECONNABORTED;
1051 	}
1052 
1053 	/* switch to large buffer if too big for a small one */
1054 	if (pdu_length > MAX_CIFS_SMALL_BUFFER_SIZE - 4) {
1055 		server->large_buf = true;
1056 		memcpy(server->bigbuf, buf, server->total_read);
1057 		buf = server->bigbuf;
1058 	}
1059 
1060 	/* now read the rest */
1061 	length = cifs_read_from_socket(server, buf + HEADER_SIZE(server) - 1,
1062 				       pdu_length - MID_HEADER_SIZE(server));
1063 
1064 	if (length < 0)
1065 		return length;
1066 	server->total_read += length;
1067 
1068 	dump_smb(buf, server->total_read);
1069 
1070 	return cifs_handle_standard(server, mid);
1071 }
1072 
1073 int
cifs_handle_standard(struct TCP_Server_Info * server,struct mid_q_entry * mid)1074 cifs_handle_standard(struct TCP_Server_Info *server, struct mid_q_entry *mid)
1075 {
1076 	char *buf = server->large_buf ? server->bigbuf : server->smallbuf;
1077 	int rc;
1078 
1079 	/*
1080 	 * We know that we received enough to get to the MID as we
1081 	 * checked the pdu_length earlier. Now check to see
1082 	 * if the rest of the header is OK.
1083 	 *
1084 	 * 48 bytes is enough to display the header and a little bit
1085 	 * into the payload for debugging purposes.
1086 	 */
1087 	rc = server->ops->check_message(buf, server->total_read, server);
1088 	if (rc)
1089 		cifs_dump_mem("Bad SMB: ", buf,
1090 			min_t(unsigned int, server->total_read, 48));
1091 
1092 	if (server->ops->is_session_expired &&
1093 	    server->ops->is_session_expired(buf)) {
1094 		cifs_reconnect(server, true);
1095 		return -1;
1096 	}
1097 
1098 	if (server->ops->is_status_pending &&
1099 	    server->ops->is_status_pending(buf, server))
1100 		return -1;
1101 
1102 	if (!mid)
1103 		return rc;
1104 
1105 	handle_mid(mid, server, buf, rc);
1106 	return 0;
1107 }
1108 
1109 static void
smb2_add_credits_from_hdr(char * buffer,struct TCP_Server_Info * server)1110 smb2_add_credits_from_hdr(char *buffer, struct TCP_Server_Info *server)
1111 {
1112 	struct smb2_hdr *shdr = (struct smb2_hdr *)buffer;
1113 	int scredits, in_flight;
1114 
1115 	/*
1116 	 * SMB1 does not use credits.
1117 	 */
1118 	if (is_smb1(server))
1119 		return;
1120 
1121 	if (shdr->CreditRequest) {
1122 		spin_lock(&server->req_lock);
1123 		server->credits += le16_to_cpu(shdr->CreditRequest);
1124 		scredits = server->credits;
1125 		in_flight = server->in_flight;
1126 		spin_unlock(&server->req_lock);
1127 		wake_up(&server->request_q);
1128 
1129 		trace_smb3_hdr_credits(server->CurrentMid,
1130 				server->conn_id, server->hostname, scredits,
1131 				le16_to_cpu(shdr->CreditRequest), in_flight);
1132 		cifs_server_dbg(FYI, "%s: added %u credits total=%d\n",
1133 				__func__, le16_to_cpu(shdr->CreditRequest),
1134 				scredits);
1135 	}
1136 }
1137 
1138 
1139 static int
cifs_demultiplex_thread(void * p)1140 cifs_demultiplex_thread(void *p)
1141 {
1142 	int i, num_mids, length;
1143 	struct TCP_Server_Info *server = p;
1144 	unsigned int pdu_length;
1145 	unsigned int next_offset;
1146 	char *buf = NULL;
1147 	struct task_struct *task_to_wake = NULL;
1148 	struct mid_q_entry *mids[MAX_COMPOUND];
1149 	char *bufs[MAX_COMPOUND];
1150 	unsigned int noreclaim_flag, num_io_timeout = 0;
1151 	bool pending_reconnect = false;
1152 
1153 	noreclaim_flag = memalloc_noreclaim_save();
1154 	cifs_dbg(FYI, "Demultiplex PID: %d\n", task_pid_nr(current));
1155 
1156 	length = atomic_inc_return(&tcpSesAllocCount);
1157 	if (length > 1)
1158 		mempool_resize(cifs_req_poolp, length + cifs_min_rcv);
1159 
1160 	set_freezable();
1161 	allow_kernel_signal(SIGKILL);
1162 	while (server->tcpStatus != CifsExiting) {
1163 		if (try_to_freeze())
1164 			continue;
1165 
1166 		if (!allocate_buffers(server))
1167 			continue;
1168 
1169 		server->large_buf = false;
1170 		buf = server->smallbuf;
1171 		pdu_length = 4; /* enough to get RFC1001 header */
1172 
1173 		length = cifs_read_from_socket(server, buf, pdu_length);
1174 		if (length < 0)
1175 			continue;
1176 
1177 		if (is_smb1(server))
1178 			server->total_read = length;
1179 		else
1180 			server->total_read = 0;
1181 
1182 		/*
1183 		 * The right amount was read from socket - 4 bytes,
1184 		 * so we can now interpret the length field.
1185 		 */
1186 		pdu_length = get_rfc1002_length(buf);
1187 
1188 		cifs_dbg(FYI, "RFC1002 header 0x%x\n", pdu_length);
1189 		if (!is_smb_response(server, buf[0]))
1190 			continue;
1191 
1192 		pending_reconnect = false;
1193 next_pdu:
1194 		server->pdu_size = pdu_length;
1195 
1196 		/* make sure we have enough to get to the MID */
1197 		if (server->pdu_size < MID_HEADER_SIZE(server)) {
1198 			cifs_server_dbg(VFS, "SMB response too short (%u bytes)\n",
1199 				 server->pdu_size);
1200 			cifs_reconnect(server, true);
1201 			continue;
1202 		}
1203 
1204 		/* read down to the MID */
1205 		length = cifs_read_from_socket(server,
1206 			     buf + HEADER_PREAMBLE_SIZE(server),
1207 			     MID_HEADER_SIZE(server));
1208 		if (length < 0)
1209 			continue;
1210 		server->total_read += length;
1211 
1212 		if (server->ops->next_header) {
1213 			if (server->ops->next_header(server, buf, &next_offset)) {
1214 				cifs_dbg(VFS, "%s: malformed response (next_offset=%u)\n",
1215 					 __func__, next_offset);
1216 				cifs_reconnect(server, true);
1217 				continue;
1218 			}
1219 			if (next_offset)
1220 				server->pdu_size = next_offset;
1221 		}
1222 
1223 		memset(mids, 0, sizeof(mids));
1224 		memset(bufs, 0, sizeof(bufs));
1225 		num_mids = 0;
1226 
1227 		if (server->ops->is_transform_hdr &&
1228 		    server->ops->receive_transform &&
1229 		    server->ops->is_transform_hdr(buf)) {
1230 			length = server->ops->receive_transform(server,
1231 								mids,
1232 								bufs,
1233 								&num_mids);
1234 		} else {
1235 			mids[0] = server->ops->find_mid(server, buf);
1236 			bufs[0] = buf;
1237 			num_mids = 1;
1238 
1239 			if (!mids[0] || !mids[0]->receive)
1240 				length = standard_receive3(server, mids[0]);
1241 			else
1242 				length = mids[0]->receive(server, mids[0]);
1243 		}
1244 
1245 		if (length < 0) {
1246 			for (i = 0; i < num_mids; i++)
1247 				if (mids[i])
1248 					release_mid(mids[i]);
1249 			continue;
1250 		}
1251 
1252 		if (server->ops->is_status_io_timeout &&
1253 		    server->ops->is_status_io_timeout(buf)) {
1254 			num_io_timeout++;
1255 			if (num_io_timeout > MAX_STATUS_IO_TIMEOUT) {
1256 				cifs_server_dbg(VFS,
1257 						"Number of request timeouts exceeded %d. Reconnecting",
1258 						MAX_STATUS_IO_TIMEOUT);
1259 
1260 				pending_reconnect = true;
1261 				num_io_timeout = 0;
1262 			}
1263 		}
1264 
1265 		server->lstrp = jiffies;
1266 
1267 		for (i = 0; i < num_mids; i++) {
1268 			if (mids[i] != NULL) {
1269 				mids[i]->resp_buf_size = server->pdu_size;
1270 
1271 				if (bufs[i] != NULL) {
1272 					if (server->ops->is_network_name_deleted &&
1273 					    server->ops->is_network_name_deleted(bufs[i],
1274 										 server)) {
1275 						cifs_server_dbg(FYI,
1276 								"Share deleted. Reconnect needed");
1277 					}
1278 				}
1279 
1280 				if (!mids[i]->multiRsp || mids[i]->multiEnd)
1281 					mids[i]->callback(mids[i]);
1282 
1283 				release_mid(mids[i]);
1284 			} else if (server->ops->is_oplock_break &&
1285 				   server->ops->is_oplock_break(bufs[i],
1286 								server)) {
1287 				smb2_add_credits_from_hdr(bufs[i], server);
1288 				cifs_dbg(FYI, "Received oplock break\n");
1289 			} else {
1290 				cifs_server_dbg(VFS, "No task to wake, unknown frame received! NumMids %d\n",
1291 						atomic_read(&mid_count));
1292 				cifs_dump_mem("Received Data is: ", bufs[i],
1293 					      HEADER_SIZE(server));
1294 				smb2_add_credits_from_hdr(bufs[i], server);
1295 #ifdef CONFIG_CIFS_DEBUG2
1296 				if (server->ops->dump_detail)
1297 					server->ops->dump_detail(bufs[i],
1298 								 server);
1299 				cifs_dump_mids(server);
1300 #endif /* CIFS_DEBUG2 */
1301 			}
1302 		}
1303 
1304 		if (pdu_length > server->pdu_size) {
1305 			if (!allocate_buffers(server))
1306 				continue;
1307 			pdu_length -= server->pdu_size;
1308 			server->total_read = 0;
1309 			server->large_buf = false;
1310 			buf = server->smallbuf;
1311 			goto next_pdu;
1312 		}
1313 
1314 		/* do this reconnect at the very end after processing all MIDs */
1315 		if (pending_reconnect)
1316 			cifs_reconnect(server, true);
1317 
1318 	} /* end while !EXITING */
1319 
1320 	/* buffer usually freed in free_mid - need to free it here on exit */
1321 	cifs_buf_release(server->bigbuf);
1322 	if (server->smallbuf) /* no sense logging a debug message if NULL */
1323 		cifs_small_buf_release(server->smallbuf);
1324 
1325 	task_to_wake = xchg(&server->tsk, NULL);
1326 	clean_demultiplex_info(server);
1327 
1328 	/* if server->tsk was NULL then wait for a signal before exiting */
1329 	if (!task_to_wake) {
1330 		set_current_state(TASK_INTERRUPTIBLE);
1331 		while (!signal_pending(current)) {
1332 			schedule();
1333 			set_current_state(TASK_INTERRUPTIBLE);
1334 		}
1335 		set_current_state(TASK_RUNNING);
1336 	}
1337 
1338 	memalloc_noreclaim_restore(noreclaim_flag);
1339 	module_put_and_kthread_exit(0);
1340 }
1341 
1342 int
cifs_ipaddr_cmp(struct sockaddr * srcaddr,struct sockaddr * rhs)1343 cifs_ipaddr_cmp(struct sockaddr *srcaddr, struct sockaddr *rhs)
1344 {
1345 	struct sockaddr_in *saddr4 = (struct sockaddr_in *)srcaddr;
1346 	struct sockaddr_in *vaddr4 = (struct sockaddr_in *)rhs;
1347 	struct sockaddr_in6 *saddr6 = (struct sockaddr_in6 *)srcaddr;
1348 	struct sockaddr_in6 *vaddr6 = (struct sockaddr_in6 *)rhs;
1349 
1350 	switch (srcaddr->sa_family) {
1351 	case AF_UNSPEC:
1352 		switch (rhs->sa_family) {
1353 		case AF_UNSPEC:
1354 			return 0;
1355 		case AF_INET:
1356 		case AF_INET6:
1357 			return 1;
1358 		default:
1359 			return -1;
1360 		}
1361 	case AF_INET: {
1362 		switch (rhs->sa_family) {
1363 		case AF_UNSPEC:
1364 			return -1;
1365 		case AF_INET:
1366 			return memcmp(saddr4, vaddr4,
1367 				      sizeof(struct sockaddr_in));
1368 		case AF_INET6:
1369 			return 1;
1370 		default:
1371 			return -1;
1372 		}
1373 	}
1374 	case AF_INET6: {
1375 		switch (rhs->sa_family) {
1376 		case AF_UNSPEC:
1377 		case AF_INET:
1378 			return -1;
1379 		case AF_INET6:
1380 			return memcmp(saddr6,
1381 				      vaddr6,
1382 				      sizeof(struct sockaddr_in6));
1383 		default:
1384 			return -1;
1385 		}
1386 	}
1387 	default:
1388 		return -1; /* don't expect to be here */
1389 	}
1390 }
1391 
1392 /*
1393  * Returns true if srcaddr isn't specified and rhs isn't specified, or
1394  * if srcaddr is specified and matches the IP address of the rhs argument
1395  */
1396 bool
cifs_match_ipaddr(struct sockaddr * srcaddr,struct sockaddr * rhs)1397 cifs_match_ipaddr(struct sockaddr *srcaddr, struct sockaddr *rhs)
1398 {
1399 	switch (srcaddr->sa_family) {
1400 	case AF_UNSPEC:
1401 		return (rhs->sa_family == AF_UNSPEC);
1402 	case AF_INET: {
1403 		struct sockaddr_in *saddr4 = (struct sockaddr_in *)srcaddr;
1404 		struct sockaddr_in *vaddr4 = (struct sockaddr_in *)rhs;
1405 		return (saddr4->sin_addr.s_addr == vaddr4->sin_addr.s_addr);
1406 	}
1407 	case AF_INET6: {
1408 		struct sockaddr_in6 *saddr6 = (struct sockaddr_in6 *)srcaddr;
1409 		struct sockaddr_in6 *vaddr6 = (struct sockaddr_in6 *)rhs;
1410 		return (ipv6_addr_equal(&saddr6->sin6_addr, &vaddr6->sin6_addr)
1411 			&& saddr6->sin6_scope_id == vaddr6->sin6_scope_id);
1412 	}
1413 	default:
1414 		WARN_ON(1);
1415 		return false; /* don't expect to be here */
1416 	}
1417 }
1418 
1419 /*
1420  * If no port is specified in addr structure, we try to match with 445 port
1421  * and if it fails - with 139 ports. It should be called only if address
1422  * families of server and addr are equal.
1423  */
1424 static bool
match_port(struct TCP_Server_Info * server,struct sockaddr * addr)1425 match_port(struct TCP_Server_Info *server, struct sockaddr *addr)
1426 {
1427 	__be16 port, *sport;
1428 
1429 	/* SMBDirect manages its own ports, don't match it here */
1430 	if (server->rdma)
1431 		return true;
1432 
1433 	switch (addr->sa_family) {
1434 	case AF_INET:
1435 		sport = &((struct sockaddr_in *) &server->dstaddr)->sin_port;
1436 		port = ((struct sockaddr_in *) addr)->sin_port;
1437 		break;
1438 	case AF_INET6:
1439 		sport = &((struct sockaddr_in6 *) &server->dstaddr)->sin6_port;
1440 		port = ((struct sockaddr_in6 *) addr)->sin6_port;
1441 		break;
1442 	default:
1443 		WARN_ON(1);
1444 		return false;
1445 	}
1446 
1447 	if (!port) {
1448 		port = htons(CIFS_PORT);
1449 		if (port == *sport)
1450 			return true;
1451 
1452 		port = htons(RFC1001_PORT);
1453 	}
1454 
1455 	return port == *sport;
1456 }
1457 
match_server_address(struct TCP_Server_Info * server,struct sockaddr * addr)1458 static bool match_server_address(struct TCP_Server_Info *server, struct sockaddr *addr)
1459 {
1460 	if (!cifs_match_ipaddr(addr, (struct sockaddr *)&server->dstaddr))
1461 		return false;
1462 
1463 	return true;
1464 }
1465 
1466 static bool
match_security(struct TCP_Server_Info * server,struct smb3_fs_context * ctx)1467 match_security(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
1468 {
1469 	/*
1470 	 * The select_sectype function should either return the ctx->sectype
1471 	 * that was specified, or "Unspecified" if that sectype was not
1472 	 * compatible with the given NEGOTIATE request.
1473 	 */
1474 	if (server->ops->select_sectype(server, ctx->sectype)
1475 	     == Unspecified)
1476 		return false;
1477 
1478 	/*
1479 	 * Now check if signing mode is acceptable. No need to check
1480 	 * global_secflags at this point since if MUST_SIGN is set then
1481 	 * the server->sign had better be too.
1482 	 */
1483 	if (ctx->sign && !server->sign)
1484 		return false;
1485 
1486 	return true;
1487 }
1488 
1489 /* this function must be called with srv_lock held */
match_server(struct TCP_Server_Info * server,struct smb3_fs_context * ctx,bool match_super)1490 static int match_server(struct TCP_Server_Info *server,
1491 			struct smb3_fs_context *ctx,
1492 			bool match_super)
1493 {
1494 	struct sockaddr *addr = (struct sockaddr *)&ctx->dstaddr;
1495 
1496 	lockdep_assert_held(&server->srv_lock);
1497 
1498 	if (ctx->nosharesock)
1499 		return 0;
1500 
1501 	/* this server does not share socket */
1502 	if (server->nosharesock)
1503 		return 0;
1504 
1505 	/* If multidialect negotiation see if existing sessions match one */
1506 	if (strcmp(ctx->vals->version_string, SMB3ANY_VERSION_STRING) == 0) {
1507 		if (server->vals->protocol_id < SMB30_PROT_ID)
1508 			return 0;
1509 	} else if (strcmp(ctx->vals->version_string,
1510 		   SMBDEFAULT_VERSION_STRING) == 0) {
1511 		if (server->vals->protocol_id < SMB21_PROT_ID)
1512 			return 0;
1513 	} else if ((server->vals != ctx->vals) || (server->ops != ctx->ops))
1514 		return 0;
1515 
1516 	if (!net_eq(cifs_net_ns(server), current->nsproxy->net_ns))
1517 		return 0;
1518 
1519 	if (!cifs_match_ipaddr((struct sockaddr *)&ctx->srcaddr,
1520 			       (struct sockaddr *)&server->srcaddr))
1521 		return 0;
1522 	/*
1523 	 * When matching cifs.ko superblocks (@match_super == true), we can't
1524 	 * really match either @server->leaf_fullpath or @server->dstaddr
1525 	 * directly since this @server might belong to a completely different
1526 	 * server -- in case of domain-based DFS referrals or DFS links -- as
1527 	 * provided earlier by mount(2) through 'source' and 'ip' options.
1528 	 *
1529 	 * Otherwise, match the DFS referral in @server->leaf_fullpath or the
1530 	 * destination address in @server->dstaddr.
1531 	 *
1532 	 * When using 'nodfs' mount option, we avoid sharing it with DFS
1533 	 * connections as they might failover.
1534 	 */
1535 	if (!match_super) {
1536 		if (!ctx->nodfs) {
1537 			if (server->leaf_fullpath) {
1538 				if (!ctx->leaf_fullpath ||
1539 				    strcasecmp(server->leaf_fullpath,
1540 					       ctx->leaf_fullpath))
1541 					return 0;
1542 			} else if (ctx->leaf_fullpath) {
1543 				return 0;
1544 			}
1545 		} else if (server->leaf_fullpath) {
1546 			return 0;
1547 		}
1548 	}
1549 
1550 	/*
1551 	 * Match for a regular connection (address/hostname/port) which has no
1552 	 * DFS referrals set.
1553 	 */
1554 	if (!server->leaf_fullpath &&
1555 	    (strcasecmp(server->hostname, ctx->server_hostname) ||
1556 	     !match_server_address(server, addr) ||
1557 	     !match_port(server, addr)))
1558 		return 0;
1559 
1560 	if (!match_security(server, ctx))
1561 		return 0;
1562 
1563 	if (server->echo_interval != ctx->echo_interval * HZ)
1564 		return 0;
1565 
1566 	if (server->rdma != ctx->rdma)
1567 		return 0;
1568 
1569 	if (server->ignore_signature != ctx->ignore_signature)
1570 		return 0;
1571 
1572 	if (server->min_offload != ctx->min_offload)
1573 		return 0;
1574 
1575 	return 1;
1576 }
1577 
1578 struct TCP_Server_Info *
cifs_find_tcp_session(struct smb3_fs_context * ctx)1579 cifs_find_tcp_session(struct smb3_fs_context *ctx)
1580 {
1581 	struct TCP_Server_Info *server;
1582 
1583 	spin_lock(&cifs_tcp_ses_lock);
1584 	list_for_each_entry(server, &cifs_tcp_ses_list, tcp_ses_list) {
1585 		spin_lock(&server->srv_lock);
1586 		/*
1587 		 * Skip ses channels since they're only handled in lower layers
1588 		 * (e.g. cifs_send_recv).
1589 		 */
1590 		if (SERVER_IS_CHAN(server) ||
1591 		    !match_server(server, ctx, false)) {
1592 			spin_unlock(&server->srv_lock);
1593 			continue;
1594 		}
1595 		spin_unlock(&server->srv_lock);
1596 
1597 		++server->srv_count;
1598 		spin_unlock(&cifs_tcp_ses_lock);
1599 		cifs_dbg(FYI, "Existing tcp session with server found\n");
1600 		return server;
1601 	}
1602 	spin_unlock(&cifs_tcp_ses_lock);
1603 	return NULL;
1604 }
1605 
1606 void
cifs_put_tcp_session(struct TCP_Server_Info * server,int from_reconnect)1607 cifs_put_tcp_session(struct TCP_Server_Info *server, int from_reconnect)
1608 {
1609 	struct task_struct *task;
1610 
1611 	spin_lock(&cifs_tcp_ses_lock);
1612 	if (--server->srv_count > 0) {
1613 		spin_unlock(&cifs_tcp_ses_lock);
1614 		return;
1615 	}
1616 
1617 	/* srv_count can never go negative */
1618 	WARN_ON(server->srv_count < 0);
1619 
1620 	put_net(cifs_net_ns(server));
1621 
1622 	list_del_init(&server->tcp_ses_list);
1623 	spin_unlock(&cifs_tcp_ses_lock);
1624 
1625 	cancel_delayed_work_sync(&server->echo);
1626 
1627 	if (from_reconnect)
1628 		/*
1629 		 * Avoid deadlock here: reconnect work calls
1630 		 * cifs_put_tcp_session() at its end. Need to be sure
1631 		 * that reconnect work does nothing with server pointer after
1632 		 * that step.
1633 		 */
1634 		cancel_delayed_work(&server->reconnect);
1635 	else
1636 		cancel_delayed_work_sync(&server->reconnect);
1637 
1638 	/* For secondary channels, we pick up ref-count on the primary server */
1639 	if (SERVER_IS_CHAN(server))
1640 		cifs_put_tcp_session(server->primary_server, from_reconnect);
1641 
1642 	spin_lock(&server->srv_lock);
1643 	server->tcpStatus = CifsExiting;
1644 	spin_unlock(&server->srv_lock);
1645 
1646 	cifs_crypto_secmech_release(server);
1647 
1648 	kfree_sensitive(server->session_key.response);
1649 	server->session_key.response = NULL;
1650 	server->session_key.len = 0;
1651 	kfree(server->hostname);
1652 	server->hostname = NULL;
1653 
1654 	task = xchg(&server->tsk, NULL);
1655 	if (task)
1656 		send_sig(SIGKILL, task, 1);
1657 }
1658 
1659 struct TCP_Server_Info *
cifs_get_tcp_session(struct smb3_fs_context * ctx,struct TCP_Server_Info * primary_server)1660 cifs_get_tcp_session(struct smb3_fs_context *ctx,
1661 		     struct TCP_Server_Info *primary_server)
1662 {
1663 	struct TCP_Server_Info *tcp_ses = NULL;
1664 	int rc;
1665 
1666 	cifs_dbg(FYI, "UNC: %s\n", ctx->UNC);
1667 
1668 	/* see if we already have a matching tcp_ses */
1669 	tcp_ses = cifs_find_tcp_session(ctx);
1670 	if (tcp_ses)
1671 		return tcp_ses;
1672 
1673 	tcp_ses = kzalloc(sizeof(struct TCP_Server_Info), GFP_KERNEL);
1674 	if (!tcp_ses) {
1675 		rc = -ENOMEM;
1676 		goto out_err;
1677 	}
1678 
1679 	tcp_ses->hostname = kstrdup(ctx->server_hostname, GFP_KERNEL);
1680 	if (!tcp_ses->hostname) {
1681 		rc = -ENOMEM;
1682 		goto out_err;
1683 	}
1684 
1685 	if (ctx->leaf_fullpath) {
1686 		tcp_ses->leaf_fullpath = kstrdup(ctx->leaf_fullpath, GFP_KERNEL);
1687 		if (!tcp_ses->leaf_fullpath) {
1688 			rc = -ENOMEM;
1689 			goto out_err;
1690 		}
1691 	}
1692 
1693 	if (ctx->nosharesock)
1694 		tcp_ses->nosharesock = true;
1695 
1696 	tcp_ses->ops = ctx->ops;
1697 	tcp_ses->vals = ctx->vals;
1698 	cifs_set_net_ns(tcp_ses, get_net(current->nsproxy->net_ns));
1699 
1700 	tcp_ses->conn_id = atomic_inc_return(&tcpSesNextId);
1701 	tcp_ses->noblockcnt = ctx->rootfs;
1702 	tcp_ses->noblocksnd = ctx->noblocksnd || ctx->rootfs;
1703 	tcp_ses->noautotune = ctx->noautotune;
1704 	tcp_ses->tcp_nodelay = ctx->sockopt_tcp_nodelay;
1705 	tcp_ses->rdma = ctx->rdma;
1706 	tcp_ses->in_flight = 0;
1707 	tcp_ses->max_in_flight = 0;
1708 	tcp_ses->credits = 1;
1709 	if (primary_server) {
1710 		spin_lock(&cifs_tcp_ses_lock);
1711 		++primary_server->srv_count;
1712 		spin_unlock(&cifs_tcp_ses_lock);
1713 		tcp_ses->primary_server = primary_server;
1714 	}
1715 	init_waitqueue_head(&tcp_ses->response_q);
1716 	init_waitqueue_head(&tcp_ses->request_q);
1717 	INIT_LIST_HEAD(&tcp_ses->pending_mid_q);
1718 	mutex_init(&tcp_ses->_srv_mutex);
1719 	memcpy(tcp_ses->workstation_RFC1001_name,
1720 		ctx->source_rfc1001_name, RFC1001_NAME_LEN_WITH_NULL);
1721 	memcpy(tcp_ses->server_RFC1001_name,
1722 		ctx->target_rfc1001_name, RFC1001_NAME_LEN_WITH_NULL);
1723 	tcp_ses->session_estab = false;
1724 	tcp_ses->sequence_number = 0;
1725 	tcp_ses->channel_sequence_num = 0; /* only tracked for primary channel */
1726 	tcp_ses->reconnect_instance = 1;
1727 	tcp_ses->lstrp = jiffies;
1728 	tcp_ses->compress_algorithm = cpu_to_le16(ctx->compression);
1729 	spin_lock_init(&tcp_ses->req_lock);
1730 	spin_lock_init(&tcp_ses->srv_lock);
1731 	spin_lock_init(&tcp_ses->mid_lock);
1732 	INIT_LIST_HEAD(&tcp_ses->tcp_ses_list);
1733 	INIT_LIST_HEAD(&tcp_ses->smb_ses_list);
1734 	INIT_DELAYED_WORK(&tcp_ses->echo, cifs_echo_request);
1735 	INIT_DELAYED_WORK(&tcp_ses->reconnect, smb2_reconnect_server);
1736 	mutex_init(&tcp_ses->reconnect_mutex);
1737 #ifdef CONFIG_CIFS_DFS_UPCALL
1738 	mutex_init(&tcp_ses->refpath_lock);
1739 #endif
1740 	memcpy(&tcp_ses->srcaddr, &ctx->srcaddr,
1741 	       sizeof(tcp_ses->srcaddr));
1742 	memcpy(&tcp_ses->dstaddr, &ctx->dstaddr,
1743 		sizeof(tcp_ses->dstaddr));
1744 	if (ctx->use_client_guid)
1745 		memcpy(tcp_ses->client_guid, ctx->client_guid,
1746 		       SMB2_CLIENT_GUID_SIZE);
1747 	else
1748 		generate_random_uuid(tcp_ses->client_guid);
1749 	/*
1750 	 * at this point we are the only ones with the pointer
1751 	 * to the struct since the kernel thread not created yet
1752 	 * no need to spinlock this init of tcpStatus or srv_count
1753 	 */
1754 	tcp_ses->tcpStatus = CifsNew;
1755 	++tcp_ses->srv_count;
1756 
1757 	if (ctx->echo_interval >= SMB_ECHO_INTERVAL_MIN &&
1758 		ctx->echo_interval <= SMB_ECHO_INTERVAL_MAX)
1759 		tcp_ses->echo_interval = ctx->echo_interval * HZ;
1760 	else
1761 		tcp_ses->echo_interval = SMB_ECHO_INTERVAL_DEFAULT * HZ;
1762 	if (tcp_ses->rdma) {
1763 #ifndef CONFIG_CIFS_SMB_DIRECT
1764 		cifs_dbg(VFS, "CONFIG_CIFS_SMB_DIRECT is not enabled\n");
1765 		rc = -ENOENT;
1766 		goto out_err_crypto_release;
1767 #endif
1768 		tcp_ses->smbd_conn = smbd_get_connection(
1769 			tcp_ses, (struct sockaddr *)&ctx->dstaddr);
1770 		if (tcp_ses->smbd_conn) {
1771 			cifs_dbg(VFS, "RDMA transport established\n");
1772 			rc = 0;
1773 			goto smbd_connected;
1774 		} else {
1775 			rc = -ENOENT;
1776 			goto out_err_crypto_release;
1777 		}
1778 	}
1779 	rc = ip_connect(tcp_ses);
1780 	if (rc < 0) {
1781 		cifs_dbg(VFS, "Error connecting to socket. Aborting operation.\n");
1782 		goto out_err_crypto_release;
1783 	}
1784 smbd_connected:
1785 	/*
1786 	 * since we're in a cifs function already, we know that
1787 	 * this will succeed. No need for try_module_get().
1788 	 */
1789 	__module_get(THIS_MODULE);
1790 	tcp_ses->tsk = kthread_run(cifs_demultiplex_thread,
1791 				  tcp_ses, "cifsd");
1792 	if (IS_ERR(tcp_ses->tsk)) {
1793 		rc = PTR_ERR(tcp_ses->tsk);
1794 		cifs_dbg(VFS, "error %d create cifsd thread\n", rc);
1795 		module_put(THIS_MODULE);
1796 		goto out_err_crypto_release;
1797 	}
1798 	tcp_ses->min_offload = ctx->min_offload;
1799 	/*
1800 	 * at this point we are the only ones with the pointer
1801 	 * to the struct since the kernel thread not created yet
1802 	 * no need to spinlock this update of tcpStatus
1803 	 */
1804 	spin_lock(&tcp_ses->srv_lock);
1805 	tcp_ses->tcpStatus = CifsNeedNegotiate;
1806 	spin_unlock(&tcp_ses->srv_lock);
1807 
1808 	if ((ctx->max_credits < 20) || (ctx->max_credits > 60000))
1809 		tcp_ses->max_credits = SMB2_MAX_CREDITS_AVAILABLE;
1810 	else
1811 		tcp_ses->max_credits = ctx->max_credits;
1812 
1813 	tcp_ses->nr_targets = 1;
1814 	tcp_ses->ignore_signature = ctx->ignore_signature;
1815 	/* thread spawned, put it on the list */
1816 	spin_lock(&cifs_tcp_ses_lock);
1817 	list_add(&tcp_ses->tcp_ses_list, &cifs_tcp_ses_list);
1818 	spin_unlock(&cifs_tcp_ses_lock);
1819 
1820 	/* queue echo request delayed work */
1821 	queue_delayed_work(cifsiod_wq, &tcp_ses->echo, tcp_ses->echo_interval);
1822 
1823 	return tcp_ses;
1824 
1825 out_err_crypto_release:
1826 	cifs_crypto_secmech_release(tcp_ses);
1827 
1828 	put_net(cifs_net_ns(tcp_ses));
1829 
1830 out_err:
1831 	if (tcp_ses) {
1832 		if (SERVER_IS_CHAN(tcp_ses))
1833 			cifs_put_tcp_session(tcp_ses->primary_server, false);
1834 		kfree(tcp_ses->hostname);
1835 		kfree(tcp_ses->leaf_fullpath);
1836 		if (tcp_ses->ssocket)
1837 			sock_release(tcp_ses->ssocket);
1838 		kfree(tcp_ses);
1839 	}
1840 	return ERR_PTR(rc);
1841 }
1842 
1843 /* this function must be called with ses_lock and chan_lock held */
match_session(struct cifs_ses * ses,struct smb3_fs_context * ctx)1844 static int match_session(struct cifs_ses *ses, struct smb3_fs_context *ctx)
1845 {
1846 	if (ctx->sectype != Unspecified &&
1847 	    ctx->sectype != ses->sectype)
1848 		return 0;
1849 
1850 	/*
1851 	 * If an existing session is limited to less channels than
1852 	 * requested, it should not be reused
1853 	 */
1854 	if (ses->chan_max < ctx->max_channels)
1855 		return 0;
1856 
1857 	switch (ses->sectype) {
1858 	case Kerberos:
1859 		if (!uid_eq(ctx->cred_uid, ses->cred_uid))
1860 			return 0;
1861 		break;
1862 	default:
1863 		/* NULL username means anonymous session */
1864 		if (ses->user_name == NULL) {
1865 			if (!ctx->nullauth)
1866 				return 0;
1867 			break;
1868 		}
1869 
1870 		/* anything else takes username/password */
1871 		if (strncmp(ses->user_name,
1872 			    ctx->username ? ctx->username : "",
1873 			    CIFS_MAX_USERNAME_LEN))
1874 			return 0;
1875 		if ((ctx->username && strlen(ctx->username) != 0) &&
1876 		    ses->password != NULL &&
1877 		    strncmp(ses->password,
1878 			    ctx->password ? ctx->password : "",
1879 			    CIFS_MAX_PASSWORD_LEN))
1880 			return 0;
1881 	}
1882 
1883 	if (strcmp(ctx->local_nls->charset, ses->local_nls->charset))
1884 		return 0;
1885 
1886 	return 1;
1887 }
1888 
1889 /**
1890  * cifs_setup_ipc - helper to setup the IPC tcon for the session
1891  * @ses: smb session to issue the request on
1892  * @ctx: the superblock configuration context to use for building the
1893  *       new tree connection for the IPC (interprocess communication RPC)
1894  *
1895  * A new IPC connection is made and stored in the session
1896  * tcon_ipc. The IPC tcon has the same lifetime as the session.
1897  */
1898 static int
cifs_setup_ipc(struct cifs_ses * ses,struct smb3_fs_context * ctx)1899 cifs_setup_ipc(struct cifs_ses *ses, struct smb3_fs_context *ctx)
1900 {
1901 	int rc = 0, xid;
1902 	struct cifs_tcon *tcon;
1903 	char unc[SERVER_NAME_LENGTH + sizeof("//x/IPC$")] = {0};
1904 	bool seal = false;
1905 	struct TCP_Server_Info *server = ses->server;
1906 
1907 	/*
1908 	 * If the mount request that resulted in the creation of the
1909 	 * session requires encryption, force IPC to be encrypted too.
1910 	 */
1911 	if (ctx->seal) {
1912 		if (server->capabilities & SMB2_GLOBAL_CAP_ENCRYPTION)
1913 			seal = true;
1914 		else {
1915 			cifs_server_dbg(VFS,
1916 				 "IPC: server doesn't support encryption\n");
1917 			return -EOPNOTSUPP;
1918 		}
1919 	}
1920 
1921 	/* no need to setup directory caching on IPC share, so pass in false */
1922 	tcon = tcon_info_alloc(false);
1923 	if (tcon == NULL)
1924 		return -ENOMEM;
1925 
1926 	spin_lock(&server->srv_lock);
1927 	scnprintf(unc, sizeof(unc), "\\\\%s\\IPC$", server->hostname);
1928 	spin_unlock(&server->srv_lock);
1929 
1930 	xid = get_xid();
1931 	tcon->ses = ses;
1932 	tcon->ipc = true;
1933 	tcon->seal = seal;
1934 	rc = server->ops->tree_connect(xid, ses, unc, tcon, ctx->local_nls);
1935 	free_xid(xid);
1936 
1937 	if (rc) {
1938 		cifs_server_dbg(VFS, "failed to connect to IPC (rc=%d)\n", rc);
1939 		tconInfoFree(tcon);
1940 		goto out;
1941 	}
1942 
1943 	cifs_dbg(FYI, "IPC tcon rc=%d ipc tid=0x%x\n", rc, tcon->tid);
1944 
1945 	spin_lock(&tcon->tc_lock);
1946 	tcon->status = TID_GOOD;
1947 	spin_unlock(&tcon->tc_lock);
1948 	ses->tcon_ipc = tcon;
1949 out:
1950 	return rc;
1951 }
1952 
1953 /**
1954  * cifs_free_ipc - helper to release the session IPC tcon
1955  * @ses: smb session to unmount the IPC from
1956  *
1957  * Needs to be called everytime a session is destroyed.
1958  *
1959  * On session close, the IPC is closed and the server must release all tcons of the session.
1960  * No need to send a tree disconnect here.
1961  *
1962  * Besides, it will make the server to not close durable and resilient files on session close, as
1963  * specified in MS-SMB2 3.3.5.6 Receiving an SMB2 LOGOFF Request.
1964  */
1965 static int
cifs_free_ipc(struct cifs_ses * ses)1966 cifs_free_ipc(struct cifs_ses *ses)
1967 {
1968 	struct cifs_tcon *tcon = ses->tcon_ipc;
1969 
1970 	if (tcon == NULL)
1971 		return 0;
1972 
1973 	tconInfoFree(tcon);
1974 	ses->tcon_ipc = NULL;
1975 	return 0;
1976 }
1977 
1978 static struct cifs_ses *
cifs_find_smb_ses(struct TCP_Server_Info * server,struct smb3_fs_context * ctx)1979 cifs_find_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
1980 {
1981 	struct cifs_ses *ses, *ret = NULL;
1982 
1983 	spin_lock(&cifs_tcp_ses_lock);
1984 	list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) {
1985 		spin_lock(&ses->ses_lock);
1986 		if (ses->ses_status == SES_EXITING) {
1987 			spin_unlock(&ses->ses_lock);
1988 			continue;
1989 		}
1990 		spin_lock(&ses->chan_lock);
1991 		if (match_session(ses, ctx)) {
1992 			spin_unlock(&ses->chan_lock);
1993 			spin_unlock(&ses->ses_lock);
1994 			ret = ses;
1995 			break;
1996 		}
1997 		spin_unlock(&ses->chan_lock);
1998 		spin_unlock(&ses->ses_lock);
1999 	}
2000 	if (ret)
2001 		cifs_smb_ses_inc_refcount(ret);
2002 	spin_unlock(&cifs_tcp_ses_lock);
2003 	return ret;
2004 }
2005 
__cifs_put_smb_ses(struct cifs_ses * ses)2006 void __cifs_put_smb_ses(struct cifs_ses *ses)
2007 {
2008 	unsigned int rc, xid;
2009 	unsigned int chan_count;
2010 	struct TCP_Server_Info *server = ses->server;
2011 
2012 	spin_lock(&ses->ses_lock);
2013 	if (ses->ses_status == SES_EXITING) {
2014 		spin_unlock(&ses->ses_lock);
2015 		return;
2016 	}
2017 	spin_unlock(&ses->ses_lock);
2018 
2019 	cifs_dbg(FYI, "%s: ses_count=%d\n", __func__, ses->ses_count);
2020 	cifs_dbg(FYI,
2021 		 "%s: ses ipc: %s\n", __func__, ses->tcon_ipc ? ses->tcon_ipc->tree_name : "NONE");
2022 
2023 	spin_lock(&cifs_tcp_ses_lock);
2024 	if (--ses->ses_count > 0) {
2025 		spin_unlock(&cifs_tcp_ses_lock);
2026 		return;
2027 	}
2028 	spin_lock(&ses->ses_lock);
2029 	if (ses->ses_status == SES_GOOD)
2030 		ses->ses_status = SES_EXITING;
2031 	spin_unlock(&ses->ses_lock);
2032 	spin_unlock(&cifs_tcp_ses_lock);
2033 
2034 	/* ses_count can never go negative */
2035 	WARN_ON(ses->ses_count < 0);
2036 
2037 	spin_lock(&ses->ses_lock);
2038 	if (ses->ses_status == SES_EXITING && server->ops->logoff) {
2039 		spin_unlock(&ses->ses_lock);
2040 		cifs_free_ipc(ses);
2041 		xid = get_xid();
2042 		rc = server->ops->logoff(xid, ses);
2043 		if (rc)
2044 			cifs_server_dbg(VFS, "%s: Session Logoff failure rc=%d\n",
2045 				__func__, rc);
2046 		_free_xid(xid);
2047 	} else {
2048 		spin_unlock(&ses->ses_lock);
2049 		cifs_free_ipc(ses);
2050 	}
2051 
2052 	spin_lock(&cifs_tcp_ses_lock);
2053 	list_del_init(&ses->smb_ses_list);
2054 	spin_unlock(&cifs_tcp_ses_lock);
2055 
2056 	chan_count = ses->chan_count;
2057 
2058 	/* close any extra channels */
2059 	if (chan_count > 1) {
2060 		int i;
2061 
2062 		for (i = 1; i < chan_count; i++) {
2063 			if (ses->chans[i].iface) {
2064 				kref_put(&ses->chans[i].iface->refcount, release_iface);
2065 				ses->chans[i].iface = NULL;
2066 			}
2067 			cifs_put_tcp_session(ses->chans[i].server, 0);
2068 			ses->chans[i].server = NULL;
2069 		}
2070 	}
2071 
2072 	/* we now account for primary channel in iface->refcount */
2073 	if (ses->chans[0].iface) {
2074 		kref_put(&ses->chans[0].iface->refcount, release_iface);
2075 		ses->chans[0].server = NULL;
2076 	}
2077 
2078 	sesInfoFree(ses);
2079 	cifs_put_tcp_session(server, 0);
2080 }
2081 
2082 #ifdef CONFIG_KEYS
2083 
2084 /* strlen("cifs:a:") + CIFS_MAX_DOMAINNAME_LEN + 1 */
2085 #define CIFSCREDS_DESC_SIZE (7 + CIFS_MAX_DOMAINNAME_LEN + 1)
2086 
2087 /* Populate username and pw fields from keyring if possible */
2088 static int
cifs_set_cifscreds(struct smb3_fs_context * ctx,struct cifs_ses * ses)2089 cifs_set_cifscreds(struct smb3_fs_context *ctx, struct cifs_ses *ses)
2090 {
2091 	int rc = 0;
2092 	int is_domain = 0;
2093 	const char *delim, *payload;
2094 	char *desc;
2095 	ssize_t len;
2096 	struct key *key;
2097 	struct TCP_Server_Info *server = ses->server;
2098 	struct sockaddr_in *sa;
2099 	struct sockaddr_in6 *sa6;
2100 	const struct user_key_payload *upayload;
2101 
2102 	desc = kmalloc(CIFSCREDS_DESC_SIZE, GFP_KERNEL);
2103 	if (!desc)
2104 		return -ENOMEM;
2105 
2106 	/* try to find an address key first */
2107 	switch (server->dstaddr.ss_family) {
2108 	case AF_INET:
2109 		sa = (struct sockaddr_in *)&server->dstaddr;
2110 		sprintf(desc, "cifs:a:%pI4", &sa->sin_addr.s_addr);
2111 		break;
2112 	case AF_INET6:
2113 		sa6 = (struct sockaddr_in6 *)&server->dstaddr;
2114 		sprintf(desc, "cifs:a:%pI6c", &sa6->sin6_addr.s6_addr);
2115 		break;
2116 	default:
2117 		cifs_dbg(FYI, "Bad ss_family (%hu)\n",
2118 			 server->dstaddr.ss_family);
2119 		rc = -EINVAL;
2120 		goto out_err;
2121 	}
2122 
2123 	cifs_dbg(FYI, "%s: desc=%s\n", __func__, desc);
2124 	key = request_key(&key_type_logon, desc, "");
2125 	if (IS_ERR(key)) {
2126 		if (!ses->domainName) {
2127 			cifs_dbg(FYI, "domainName is NULL\n");
2128 			rc = PTR_ERR(key);
2129 			goto out_err;
2130 		}
2131 
2132 		/* didn't work, try to find a domain key */
2133 		sprintf(desc, "cifs:d:%s", ses->domainName);
2134 		cifs_dbg(FYI, "%s: desc=%s\n", __func__, desc);
2135 		key = request_key(&key_type_logon, desc, "");
2136 		if (IS_ERR(key)) {
2137 			rc = PTR_ERR(key);
2138 			goto out_err;
2139 		}
2140 		is_domain = 1;
2141 	}
2142 
2143 	down_read(&key->sem);
2144 	upayload = user_key_payload_locked(key);
2145 	if (IS_ERR_OR_NULL(upayload)) {
2146 		rc = upayload ? PTR_ERR(upayload) : -EINVAL;
2147 		goto out_key_put;
2148 	}
2149 
2150 	/* find first : in payload */
2151 	payload = upayload->data;
2152 	delim = strnchr(payload, upayload->datalen, ':');
2153 	cifs_dbg(FYI, "payload=%s\n", payload);
2154 	if (!delim) {
2155 		cifs_dbg(FYI, "Unable to find ':' in payload (datalen=%d)\n",
2156 			 upayload->datalen);
2157 		rc = -EINVAL;
2158 		goto out_key_put;
2159 	}
2160 
2161 	len = delim - payload;
2162 	if (len > CIFS_MAX_USERNAME_LEN || len <= 0) {
2163 		cifs_dbg(FYI, "Bad value from username search (len=%zd)\n",
2164 			 len);
2165 		rc = -EINVAL;
2166 		goto out_key_put;
2167 	}
2168 
2169 	ctx->username = kstrndup(payload, len, GFP_KERNEL);
2170 	if (!ctx->username) {
2171 		cifs_dbg(FYI, "Unable to allocate %zd bytes for username\n",
2172 			 len);
2173 		rc = -ENOMEM;
2174 		goto out_key_put;
2175 	}
2176 	cifs_dbg(FYI, "%s: username=%s\n", __func__, ctx->username);
2177 
2178 	len = key->datalen - (len + 1);
2179 	if (len > CIFS_MAX_PASSWORD_LEN || len <= 0) {
2180 		cifs_dbg(FYI, "Bad len for password search (len=%zd)\n", len);
2181 		rc = -EINVAL;
2182 		kfree(ctx->username);
2183 		ctx->username = NULL;
2184 		goto out_key_put;
2185 	}
2186 
2187 	++delim;
2188 	ctx->password = kstrndup(delim, len, GFP_KERNEL);
2189 	if (!ctx->password) {
2190 		cifs_dbg(FYI, "Unable to allocate %zd bytes for password\n",
2191 			 len);
2192 		rc = -ENOMEM;
2193 		kfree(ctx->username);
2194 		ctx->username = NULL;
2195 		goto out_key_put;
2196 	}
2197 
2198 	/*
2199 	 * If we have a domain key then we must set the domainName in the
2200 	 * for the request.
2201 	 */
2202 	if (is_domain && ses->domainName) {
2203 		ctx->domainname = kstrdup(ses->domainName, GFP_KERNEL);
2204 		if (!ctx->domainname) {
2205 			cifs_dbg(FYI, "Unable to allocate %zd bytes for domain\n",
2206 				 len);
2207 			rc = -ENOMEM;
2208 			kfree(ctx->username);
2209 			ctx->username = NULL;
2210 			kfree_sensitive(ctx->password);
2211 			ctx->password = NULL;
2212 			goto out_key_put;
2213 		}
2214 	}
2215 
2216 	strscpy(ctx->workstation_name, ses->workstation_name, sizeof(ctx->workstation_name));
2217 
2218 out_key_put:
2219 	up_read(&key->sem);
2220 	key_put(key);
2221 out_err:
2222 	kfree(desc);
2223 	cifs_dbg(FYI, "%s: returning %d\n", __func__, rc);
2224 	return rc;
2225 }
2226 #else /* ! CONFIG_KEYS */
2227 static inline int
cifs_set_cifscreds(struct smb3_fs_context * ctx,struct cifs_ses * ses)2228 cifs_set_cifscreds(struct smb3_fs_context *ctx __attribute__((unused)),
2229 		   struct cifs_ses *ses __attribute__((unused)))
2230 {
2231 	return -ENOSYS;
2232 }
2233 #endif /* CONFIG_KEYS */
2234 
2235 /**
2236  * cifs_get_smb_ses - get a session matching @ctx data from @server
2237  * @server: server to setup the session to
2238  * @ctx: superblock configuration context to use to setup the session
2239  *
2240  * This function assumes it is being called from cifs_mount() where we
2241  * already got a server reference (server refcount +1). See
2242  * cifs_get_tcon() for refcount explanations.
2243  */
2244 struct cifs_ses *
cifs_get_smb_ses(struct TCP_Server_Info * server,struct smb3_fs_context * ctx)2245 cifs_get_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
2246 {
2247 	int rc = 0;
2248 	unsigned int xid;
2249 	struct cifs_ses *ses;
2250 	struct sockaddr_in *addr = (struct sockaddr_in *)&server->dstaddr;
2251 	struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&server->dstaddr;
2252 
2253 	xid = get_xid();
2254 
2255 	ses = cifs_find_smb_ses(server, ctx);
2256 	if (ses) {
2257 		cifs_dbg(FYI, "Existing smb sess found (status=%d)\n",
2258 			 ses->ses_status);
2259 
2260 		spin_lock(&ses->chan_lock);
2261 		if (cifs_chan_needs_reconnect(ses, server)) {
2262 			spin_unlock(&ses->chan_lock);
2263 			cifs_dbg(FYI, "Session needs reconnect\n");
2264 
2265 			mutex_lock(&ses->session_mutex);
2266 			rc = cifs_negotiate_protocol(xid, ses, server);
2267 			if (rc) {
2268 				mutex_unlock(&ses->session_mutex);
2269 				/* problem -- put our ses reference */
2270 				cifs_put_smb_ses(ses);
2271 				free_xid(xid);
2272 				return ERR_PTR(rc);
2273 			}
2274 
2275 			rc = cifs_setup_session(xid, ses, server,
2276 						ctx->local_nls);
2277 			if (rc) {
2278 				mutex_unlock(&ses->session_mutex);
2279 				/* problem -- put our reference */
2280 				cifs_put_smb_ses(ses);
2281 				free_xid(xid);
2282 				return ERR_PTR(rc);
2283 			}
2284 			mutex_unlock(&ses->session_mutex);
2285 
2286 			spin_lock(&ses->chan_lock);
2287 		}
2288 		spin_unlock(&ses->chan_lock);
2289 
2290 		/* existing SMB ses has a server reference already */
2291 		cifs_put_tcp_session(server, 0);
2292 		free_xid(xid);
2293 		return ses;
2294 	}
2295 
2296 	rc = -ENOMEM;
2297 
2298 	cifs_dbg(FYI, "Existing smb sess not found\n");
2299 	ses = sesInfoAlloc();
2300 	if (ses == NULL)
2301 		goto get_ses_fail;
2302 
2303 	/* new SMB session uses our server ref */
2304 	ses->server = server;
2305 	if (server->dstaddr.ss_family == AF_INET6)
2306 		sprintf(ses->ip_addr, "%pI6", &addr6->sin6_addr);
2307 	else
2308 		sprintf(ses->ip_addr, "%pI4", &addr->sin_addr);
2309 
2310 	if (ctx->username) {
2311 		ses->user_name = kstrdup(ctx->username, GFP_KERNEL);
2312 		if (!ses->user_name)
2313 			goto get_ses_fail;
2314 	}
2315 
2316 	/* ctx->password freed at unmount */
2317 	if (ctx->password) {
2318 		ses->password = kstrdup(ctx->password, GFP_KERNEL);
2319 		if (!ses->password)
2320 			goto get_ses_fail;
2321 	}
2322 	if (ctx->domainname) {
2323 		ses->domainName = kstrdup(ctx->domainname, GFP_KERNEL);
2324 		if (!ses->domainName)
2325 			goto get_ses_fail;
2326 	}
2327 
2328 	strscpy(ses->workstation_name, ctx->workstation_name, sizeof(ses->workstation_name));
2329 
2330 	if (ctx->domainauto)
2331 		ses->domainAuto = ctx->domainauto;
2332 	ses->cred_uid = ctx->cred_uid;
2333 	ses->linux_uid = ctx->linux_uid;
2334 
2335 	ses->sectype = ctx->sectype;
2336 	ses->sign = ctx->sign;
2337 	ses->local_nls = load_nls(ctx->local_nls->charset);
2338 
2339 	/* add server as first channel */
2340 	spin_lock(&ses->chan_lock);
2341 	ses->chans[0].server = server;
2342 	ses->chan_count = 1;
2343 	ses->chan_max = ctx->multichannel ? ctx->max_channels:1;
2344 	ses->chans_need_reconnect = 1;
2345 	spin_unlock(&ses->chan_lock);
2346 
2347 	mutex_lock(&ses->session_mutex);
2348 	rc = cifs_negotiate_protocol(xid, ses, server);
2349 	if (!rc)
2350 		rc = cifs_setup_session(xid, ses, server, ctx->local_nls);
2351 	mutex_unlock(&ses->session_mutex);
2352 
2353 	/* each channel uses a different signing key */
2354 	spin_lock(&ses->chan_lock);
2355 	memcpy(ses->chans[0].signkey, ses->smb3signingkey,
2356 	       sizeof(ses->smb3signingkey));
2357 	spin_unlock(&ses->chan_lock);
2358 
2359 	if (rc)
2360 		goto get_ses_fail;
2361 
2362 	/*
2363 	 * success, put it on the list and add it as first channel
2364 	 * note: the session becomes active soon after this. So you'll
2365 	 * need to lock before changing something in the session.
2366 	 */
2367 	spin_lock(&cifs_tcp_ses_lock);
2368 	ses->dfs_root_ses = ctx->dfs_root_ses;
2369 	if (ses->dfs_root_ses)
2370 		ses->dfs_root_ses->ses_count++;
2371 	list_add(&ses->smb_ses_list, &server->smb_ses_list);
2372 	spin_unlock(&cifs_tcp_ses_lock);
2373 
2374 	cifs_setup_ipc(ses, ctx);
2375 
2376 	free_xid(xid);
2377 
2378 	return ses;
2379 
2380 get_ses_fail:
2381 	sesInfoFree(ses);
2382 	free_xid(xid);
2383 	return ERR_PTR(rc);
2384 }
2385 
2386 /* this function must be called with tc_lock held */
match_tcon(struct cifs_tcon * tcon,struct smb3_fs_context * ctx)2387 static int match_tcon(struct cifs_tcon *tcon, struct smb3_fs_context *ctx)
2388 {
2389 	struct TCP_Server_Info *server = tcon->ses->server;
2390 
2391 	if (tcon->status == TID_EXITING)
2392 		return 0;
2393 
2394 	if (tcon->origin_fullpath) {
2395 		if (!ctx->source ||
2396 		    !dfs_src_pathname_equal(ctx->source,
2397 					    tcon->origin_fullpath))
2398 			return 0;
2399 	} else if (!server->leaf_fullpath &&
2400 		   strncmp(tcon->tree_name, ctx->UNC, MAX_TREE_SIZE)) {
2401 		return 0;
2402 	}
2403 	if (tcon->seal != ctx->seal)
2404 		return 0;
2405 	if (tcon->snapshot_time != ctx->snapshot_time)
2406 		return 0;
2407 	if (tcon->handle_timeout != ctx->handle_timeout)
2408 		return 0;
2409 	if (tcon->no_lease != ctx->no_lease)
2410 		return 0;
2411 	if (tcon->nodelete != ctx->nodelete)
2412 		return 0;
2413 	return 1;
2414 }
2415 
2416 static struct cifs_tcon *
cifs_find_tcon(struct cifs_ses * ses,struct smb3_fs_context * ctx)2417 cifs_find_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx)
2418 {
2419 	struct cifs_tcon *tcon;
2420 
2421 	spin_lock(&cifs_tcp_ses_lock);
2422 	list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
2423 		spin_lock(&tcon->tc_lock);
2424 		if (!match_tcon(tcon, ctx)) {
2425 			spin_unlock(&tcon->tc_lock);
2426 			continue;
2427 		}
2428 		++tcon->tc_count;
2429 		spin_unlock(&tcon->tc_lock);
2430 		spin_unlock(&cifs_tcp_ses_lock);
2431 		return tcon;
2432 	}
2433 	spin_unlock(&cifs_tcp_ses_lock);
2434 	return NULL;
2435 }
2436 
2437 void
cifs_put_tcon(struct cifs_tcon * tcon)2438 cifs_put_tcon(struct cifs_tcon *tcon)
2439 {
2440 	unsigned int xid;
2441 	struct cifs_ses *ses;
2442 
2443 	/*
2444 	 * IPC tcon share the lifetime of their session and are
2445 	 * destroyed in the session put function
2446 	 */
2447 	if (tcon == NULL || tcon->ipc)
2448 		return;
2449 
2450 	ses = tcon->ses;
2451 	cifs_dbg(FYI, "%s: tc_count=%d\n", __func__, tcon->tc_count);
2452 	spin_lock(&cifs_tcp_ses_lock);
2453 	spin_lock(&tcon->tc_lock);
2454 	if (--tcon->tc_count > 0) {
2455 		spin_unlock(&tcon->tc_lock);
2456 		spin_unlock(&cifs_tcp_ses_lock);
2457 		return;
2458 	}
2459 
2460 	/* tc_count can never go negative */
2461 	WARN_ON(tcon->tc_count < 0);
2462 
2463 	list_del_init(&tcon->tcon_list);
2464 	tcon->status = TID_EXITING;
2465 	spin_unlock(&tcon->tc_lock);
2466 	spin_unlock(&cifs_tcp_ses_lock);
2467 
2468 	/* cancel polling of interfaces */
2469 	cancel_delayed_work_sync(&tcon->query_interfaces);
2470 #ifdef CONFIG_CIFS_DFS_UPCALL
2471 	cancel_delayed_work_sync(&tcon->dfs_cache_work);
2472 #endif
2473 
2474 	if (tcon->use_witness) {
2475 		int rc;
2476 
2477 		rc = cifs_swn_unregister(tcon);
2478 		if (rc < 0) {
2479 			cifs_dbg(VFS, "%s: Failed to unregister for witness notifications: %d\n",
2480 					__func__, rc);
2481 		}
2482 	}
2483 
2484 	xid = get_xid();
2485 	if (ses->server->ops->tree_disconnect)
2486 		ses->server->ops->tree_disconnect(xid, tcon);
2487 	_free_xid(xid);
2488 
2489 	cifs_fscache_release_super_cookie(tcon);
2490 	tconInfoFree(tcon);
2491 	cifs_put_smb_ses(ses);
2492 }
2493 
2494 /**
2495  * cifs_get_tcon - get a tcon matching @ctx data from @ses
2496  * @ses: smb session to issue the request on
2497  * @ctx: the superblock configuration context to use for building the
2498  *
2499  * - tcon refcount is the number of mount points using the tcon.
2500  * - ses refcount is the number of tcon using the session.
2501  *
2502  * 1. This function assumes it is being called from cifs_mount() where
2503  *    we already got a session reference (ses refcount +1).
2504  *
2505  * 2. Since we're in the context of adding a mount point, the end
2506  *    result should be either:
2507  *
2508  * a) a new tcon already allocated with refcount=1 (1 mount point) and
2509  *    its session refcount incremented (1 new tcon). This +1 was
2510  *    already done in (1).
2511  *
2512  * b) an existing tcon with refcount+1 (add a mount point to it) and
2513  *    identical ses refcount (no new tcon). Because of (1) we need to
2514  *    decrement the ses refcount.
2515  */
2516 static struct cifs_tcon *
cifs_get_tcon(struct cifs_ses * ses,struct smb3_fs_context * ctx)2517 cifs_get_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx)
2518 {
2519 	struct cifs_tcon *tcon;
2520 	bool nohandlecache;
2521 	int rc, xid;
2522 
2523 	tcon = cifs_find_tcon(ses, ctx);
2524 	if (tcon) {
2525 		/*
2526 		 * tcon has refcount already incremented but we need to
2527 		 * decrement extra ses reference gotten by caller (case b)
2528 		 */
2529 		cifs_dbg(FYI, "Found match on UNC path\n");
2530 		cifs_put_smb_ses(ses);
2531 		return tcon;
2532 	}
2533 
2534 	if (!ses->server->ops->tree_connect) {
2535 		rc = -ENOSYS;
2536 		goto out_fail;
2537 	}
2538 
2539 	if (ses->server->dialect >= SMB20_PROT_ID &&
2540 	    (ses->server->capabilities & SMB2_GLOBAL_CAP_DIRECTORY_LEASING))
2541 		nohandlecache = ctx->nohandlecache;
2542 	else
2543 		nohandlecache = true;
2544 	tcon = tcon_info_alloc(!nohandlecache);
2545 	if (tcon == NULL) {
2546 		rc = -ENOMEM;
2547 		goto out_fail;
2548 	}
2549 	tcon->nohandlecache = nohandlecache;
2550 
2551 	if (ctx->snapshot_time) {
2552 		if (ses->server->vals->protocol_id == 0) {
2553 			cifs_dbg(VFS,
2554 			     "Use SMB2 or later for snapshot mount option\n");
2555 			rc = -EOPNOTSUPP;
2556 			goto out_fail;
2557 		} else
2558 			tcon->snapshot_time = ctx->snapshot_time;
2559 	}
2560 
2561 	if (ctx->handle_timeout) {
2562 		if (ses->server->vals->protocol_id == 0) {
2563 			cifs_dbg(VFS,
2564 			     "Use SMB2.1 or later for handle timeout option\n");
2565 			rc = -EOPNOTSUPP;
2566 			goto out_fail;
2567 		} else
2568 			tcon->handle_timeout = ctx->handle_timeout;
2569 	}
2570 
2571 	tcon->ses = ses;
2572 	if (ctx->password) {
2573 		tcon->password = kstrdup(ctx->password, GFP_KERNEL);
2574 		if (!tcon->password) {
2575 			rc = -ENOMEM;
2576 			goto out_fail;
2577 		}
2578 	}
2579 
2580 	if (ctx->seal) {
2581 		if (ses->server->vals->protocol_id == 0) {
2582 			cifs_dbg(VFS,
2583 				 "SMB3 or later required for encryption\n");
2584 			rc = -EOPNOTSUPP;
2585 			goto out_fail;
2586 		} else if (tcon->ses->server->capabilities &
2587 					SMB2_GLOBAL_CAP_ENCRYPTION)
2588 			tcon->seal = true;
2589 		else {
2590 			cifs_dbg(VFS, "Encryption is not supported on share\n");
2591 			rc = -EOPNOTSUPP;
2592 			goto out_fail;
2593 		}
2594 	}
2595 
2596 	if (ctx->linux_ext) {
2597 		if (ses->server->posix_ext_supported) {
2598 			tcon->posix_extensions = true;
2599 			pr_warn_once("SMB3.11 POSIX Extensions are experimental\n");
2600 		} else if ((ses->server->vals->protocol_id == SMB311_PROT_ID) ||
2601 		    (strcmp(ses->server->vals->version_string,
2602 		     SMB3ANY_VERSION_STRING) == 0) ||
2603 		    (strcmp(ses->server->vals->version_string,
2604 		     SMBDEFAULT_VERSION_STRING) == 0)) {
2605 			cifs_dbg(VFS, "Server does not support mounting with posix SMB3.11 extensions\n");
2606 			rc = -EOPNOTSUPP;
2607 			goto out_fail;
2608 		} else {
2609 			cifs_dbg(VFS, "Check vers= mount option. SMB3.11 "
2610 				"disabled but required for POSIX extensions\n");
2611 			rc = -EOPNOTSUPP;
2612 			goto out_fail;
2613 		}
2614 	}
2615 
2616 	xid = get_xid();
2617 	rc = ses->server->ops->tree_connect(xid, ses, ctx->UNC, tcon,
2618 					    ctx->local_nls);
2619 	free_xid(xid);
2620 	cifs_dbg(FYI, "Tcon rc = %d\n", rc);
2621 	if (rc)
2622 		goto out_fail;
2623 
2624 	tcon->use_persistent = false;
2625 	/* check if SMB2 or later, CIFS does not support persistent handles */
2626 	if (ctx->persistent) {
2627 		if (ses->server->vals->protocol_id == 0) {
2628 			cifs_dbg(VFS,
2629 			     "SMB3 or later required for persistent handles\n");
2630 			rc = -EOPNOTSUPP;
2631 			goto out_fail;
2632 		} else if (ses->server->capabilities &
2633 			   SMB2_GLOBAL_CAP_PERSISTENT_HANDLES)
2634 			tcon->use_persistent = true;
2635 		else /* persistent handles requested but not supported */ {
2636 			cifs_dbg(VFS,
2637 				"Persistent handles not supported on share\n");
2638 			rc = -EOPNOTSUPP;
2639 			goto out_fail;
2640 		}
2641 	} else if ((tcon->capabilities & SMB2_SHARE_CAP_CONTINUOUS_AVAILABILITY)
2642 	     && (ses->server->capabilities & SMB2_GLOBAL_CAP_PERSISTENT_HANDLES)
2643 	     && (ctx->nopersistent == false)) {
2644 		cifs_dbg(FYI, "enabling persistent handles\n");
2645 		tcon->use_persistent = true;
2646 	} else if (ctx->resilient) {
2647 		if (ses->server->vals->protocol_id == 0) {
2648 			cifs_dbg(VFS,
2649 			     "SMB2.1 or later required for resilient handles\n");
2650 			rc = -EOPNOTSUPP;
2651 			goto out_fail;
2652 		}
2653 		tcon->use_resilient = true;
2654 	}
2655 
2656 	tcon->use_witness = false;
2657 	if (IS_ENABLED(CONFIG_CIFS_SWN_UPCALL) && ctx->witness) {
2658 		if (ses->server->vals->protocol_id >= SMB30_PROT_ID) {
2659 			if (tcon->capabilities & SMB2_SHARE_CAP_CLUSTER) {
2660 				/*
2661 				 * Set witness in use flag in first place
2662 				 * to retry registration in the echo task
2663 				 */
2664 				tcon->use_witness = true;
2665 				/* And try to register immediately */
2666 				rc = cifs_swn_register(tcon);
2667 				if (rc < 0) {
2668 					cifs_dbg(VFS, "Failed to register for witness notifications: %d\n", rc);
2669 					goto out_fail;
2670 				}
2671 			} else {
2672 				/* TODO: try to extend for non-cluster uses (eg multichannel) */
2673 				cifs_dbg(VFS, "witness requested on mount but no CLUSTER capability on share\n");
2674 				rc = -EOPNOTSUPP;
2675 				goto out_fail;
2676 			}
2677 		} else {
2678 			cifs_dbg(VFS, "SMB3 or later required for witness option\n");
2679 			rc = -EOPNOTSUPP;
2680 			goto out_fail;
2681 		}
2682 	}
2683 
2684 	/* If the user really knows what they are doing they can override */
2685 	if (tcon->share_flags & SMB2_SHAREFLAG_NO_CACHING) {
2686 		if (ctx->cache_ro)
2687 			cifs_dbg(VFS, "cache=ro requested on mount but NO_CACHING flag set on share\n");
2688 		else if (ctx->cache_rw)
2689 			cifs_dbg(VFS, "cache=singleclient requested on mount but NO_CACHING flag set on share\n");
2690 	}
2691 
2692 	if (ctx->no_lease) {
2693 		if (ses->server->vals->protocol_id == 0) {
2694 			cifs_dbg(VFS,
2695 				"SMB2 or later required for nolease option\n");
2696 			rc = -EOPNOTSUPP;
2697 			goto out_fail;
2698 		} else
2699 			tcon->no_lease = ctx->no_lease;
2700 	}
2701 
2702 	/*
2703 	 * We can have only one retry value for a connection to a share so for
2704 	 * resources mounted more than once to the same server share the last
2705 	 * value passed in for the retry flag is used.
2706 	 */
2707 	tcon->retry = ctx->retry;
2708 	tcon->nocase = ctx->nocase;
2709 	tcon->broken_sparse_sup = ctx->no_sparse;
2710 	tcon->max_cached_dirs = ctx->max_cached_dirs;
2711 	tcon->nodelete = ctx->nodelete;
2712 	tcon->local_lease = ctx->local_lease;
2713 	INIT_LIST_HEAD(&tcon->pending_opens);
2714 	tcon->status = TID_GOOD;
2715 
2716 	INIT_DELAYED_WORK(&tcon->query_interfaces,
2717 			  smb2_query_server_interfaces);
2718 	if (ses->server->dialect >= SMB30_PROT_ID &&
2719 	    (ses->server->capabilities & SMB2_GLOBAL_CAP_MULTI_CHANNEL)) {
2720 		/* schedule query interfaces poll */
2721 		queue_delayed_work(cifsiod_wq, &tcon->query_interfaces,
2722 				   (SMB_INTERFACE_POLL_INTERVAL * HZ));
2723 	}
2724 #ifdef CONFIG_CIFS_DFS_UPCALL
2725 	INIT_DELAYED_WORK(&tcon->dfs_cache_work, dfs_cache_refresh);
2726 #endif
2727 	spin_lock(&cifs_tcp_ses_lock);
2728 	list_add(&tcon->tcon_list, &ses->tcon_list);
2729 	spin_unlock(&cifs_tcp_ses_lock);
2730 
2731 	return tcon;
2732 
2733 out_fail:
2734 	tconInfoFree(tcon);
2735 	return ERR_PTR(rc);
2736 }
2737 
2738 void
cifs_put_tlink(struct tcon_link * tlink)2739 cifs_put_tlink(struct tcon_link *tlink)
2740 {
2741 	if (!tlink || IS_ERR(tlink))
2742 		return;
2743 
2744 	if (!atomic_dec_and_test(&tlink->tl_count) ||
2745 	    test_bit(TCON_LINK_IN_TREE, &tlink->tl_flags)) {
2746 		tlink->tl_time = jiffies;
2747 		return;
2748 	}
2749 
2750 	if (!IS_ERR(tlink_tcon(tlink)))
2751 		cifs_put_tcon(tlink_tcon(tlink));
2752 	kfree(tlink);
2753 	return;
2754 }
2755 
2756 static int
compare_mount_options(struct super_block * sb,struct cifs_mnt_data * mnt_data)2757 compare_mount_options(struct super_block *sb, struct cifs_mnt_data *mnt_data)
2758 {
2759 	struct cifs_sb_info *old = CIFS_SB(sb);
2760 	struct cifs_sb_info *new = mnt_data->cifs_sb;
2761 	unsigned int oldflags = old->mnt_cifs_flags & CIFS_MOUNT_MASK;
2762 	unsigned int newflags = new->mnt_cifs_flags & CIFS_MOUNT_MASK;
2763 
2764 	if ((sb->s_flags & CIFS_MS_MASK) != (mnt_data->flags & CIFS_MS_MASK))
2765 		return 0;
2766 
2767 	if (old->mnt_cifs_serverino_autodisabled)
2768 		newflags &= ~CIFS_MOUNT_SERVER_INUM;
2769 
2770 	if (oldflags != newflags)
2771 		return 0;
2772 
2773 	/*
2774 	 * We want to share sb only if we don't specify an r/wsize or
2775 	 * specified r/wsize is greater than or equal to existing one.
2776 	 */
2777 	if (new->ctx->wsize && new->ctx->wsize < old->ctx->wsize)
2778 		return 0;
2779 
2780 	if (new->ctx->rsize && new->ctx->rsize < old->ctx->rsize)
2781 		return 0;
2782 
2783 	if (!uid_eq(old->ctx->linux_uid, new->ctx->linux_uid) ||
2784 	    !gid_eq(old->ctx->linux_gid, new->ctx->linux_gid))
2785 		return 0;
2786 
2787 	if (old->ctx->file_mode != new->ctx->file_mode ||
2788 	    old->ctx->dir_mode != new->ctx->dir_mode)
2789 		return 0;
2790 
2791 	if (strcmp(old->local_nls->charset, new->local_nls->charset))
2792 		return 0;
2793 
2794 	if (old->ctx->acregmax != new->ctx->acregmax)
2795 		return 0;
2796 	if (old->ctx->acdirmax != new->ctx->acdirmax)
2797 		return 0;
2798 	if (old->ctx->closetimeo != new->ctx->closetimeo)
2799 		return 0;
2800 
2801 	return 1;
2802 }
2803 
match_prepath(struct super_block * sb,struct cifs_tcon * tcon,struct cifs_mnt_data * mnt_data)2804 static int match_prepath(struct super_block *sb,
2805 			 struct cifs_tcon *tcon,
2806 			 struct cifs_mnt_data *mnt_data)
2807 {
2808 	struct smb3_fs_context *ctx = mnt_data->ctx;
2809 	struct cifs_sb_info *old = CIFS_SB(sb);
2810 	struct cifs_sb_info *new = mnt_data->cifs_sb;
2811 	bool old_set = (old->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH) &&
2812 		old->prepath;
2813 	bool new_set = (new->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH) &&
2814 		new->prepath;
2815 
2816 	if (tcon->origin_fullpath &&
2817 	    dfs_src_pathname_equal(tcon->origin_fullpath, ctx->source))
2818 		return 1;
2819 
2820 	if (old_set && new_set && !strcmp(new->prepath, old->prepath))
2821 		return 1;
2822 	else if (!old_set && !new_set)
2823 		return 1;
2824 
2825 	return 0;
2826 }
2827 
2828 int
cifs_match_super(struct super_block * sb,void * data)2829 cifs_match_super(struct super_block *sb, void *data)
2830 {
2831 	struct cifs_mnt_data *mnt_data = data;
2832 	struct smb3_fs_context *ctx;
2833 	struct cifs_sb_info *cifs_sb;
2834 	struct TCP_Server_Info *tcp_srv;
2835 	struct cifs_ses *ses;
2836 	struct cifs_tcon *tcon;
2837 	struct tcon_link *tlink;
2838 	int rc = 0;
2839 
2840 	spin_lock(&cifs_tcp_ses_lock);
2841 	cifs_sb = CIFS_SB(sb);
2842 
2843 	/* We do not want to use a superblock that has been shutdown */
2844 	if (CIFS_MOUNT_SHUTDOWN & cifs_sb->mnt_cifs_flags) {
2845 		spin_unlock(&cifs_tcp_ses_lock);
2846 		return 0;
2847 	}
2848 
2849 	tlink = cifs_get_tlink(cifs_sb_master_tlink(cifs_sb));
2850 	if (IS_ERR_OR_NULL(tlink)) {
2851 		pr_warn_once("%s: skip super matching due to bad tlink(%p)\n",
2852 			     __func__, tlink);
2853 		spin_unlock(&cifs_tcp_ses_lock);
2854 		return 0;
2855 	}
2856 	tcon = tlink_tcon(tlink);
2857 	ses = tcon->ses;
2858 	tcp_srv = ses->server;
2859 
2860 	ctx = mnt_data->ctx;
2861 
2862 	spin_lock(&tcp_srv->srv_lock);
2863 	spin_lock(&ses->ses_lock);
2864 	spin_lock(&ses->chan_lock);
2865 	spin_lock(&tcon->tc_lock);
2866 	if (!match_server(tcp_srv, ctx, true) ||
2867 	    !match_session(ses, ctx) ||
2868 	    !match_tcon(tcon, ctx) ||
2869 	    !match_prepath(sb, tcon, mnt_data)) {
2870 		rc = 0;
2871 		goto out;
2872 	}
2873 
2874 	rc = compare_mount_options(sb, mnt_data);
2875 out:
2876 	spin_unlock(&tcon->tc_lock);
2877 	spin_unlock(&ses->chan_lock);
2878 	spin_unlock(&ses->ses_lock);
2879 	spin_unlock(&tcp_srv->srv_lock);
2880 
2881 	spin_unlock(&cifs_tcp_ses_lock);
2882 	cifs_put_tlink(tlink);
2883 	return rc;
2884 }
2885 
2886 #ifdef CONFIG_DEBUG_LOCK_ALLOC
2887 static struct lock_class_key cifs_key[2];
2888 static struct lock_class_key cifs_slock_key[2];
2889 
2890 static inline void
cifs_reclassify_socket4(struct socket * sock)2891 cifs_reclassify_socket4(struct socket *sock)
2892 {
2893 	struct sock *sk = sock->sk;
2894 	BUG_ON(!sock_allow_reclassification(sk));
2895 	sock_lock_init_class_and_name(sk, "slock-AF_INET-CIFS",
2896 		&cifs_slock_key[0], "sk_lock-AF_INET-CIFS", &cifs_key[0]);
2897 }
2898 
2899 static inline void
cifs_reclassify_socket6(struct socket * sock)2900 cifs_reclassify_socket6(struct socket *sock)
2901 {
2902 	struct sock *sk = sock->sk;
2903 	BUG_ON(!sock_allow_reclassification(sk));
2904 	sock_lock_init_class_and_name(sk, "slock-AF_INET6-CIFS",
2905 		&cifs_slock_key[1], "sk_lock-AF_INET6-CIFS", &cifs_key[1]);
2906 }
2907 #else
2908 static inline void
cifs_reclassify_socket4(struct socket * sock)2909 cifs_reclassify_socket4(struct socket *sock)
2910 {
2911 }
2912 
2913 static inline void
cifs_reclassify_socket6(struct socket * sock)2914 cifs_reclassify_socket6(struct socket *sock)
2915 {
2916 }
2917 #endif
2918 
2919 /* See RFC1001 section 14 on representation of Netbios names */
rfc1002mangle(char * target,char * source,unsigned int length)2920 static void rfc1002mangle(char *target, char *source, unsigned int length)
2921 {
2922 	unsigned int i, j;
2923 
2924 	for (i = 0, j = 0; i < (length); i++) {
2925 		/* mask a nibble at a time and encode */
2926 		target[j] = 'A' + (0x0F & (source[i] >> 4));
2927 		target[j+1] = 'A' + (0x0F & source[i]);
2928 		j += 2;
2929 	}
2930 
2931 }
2932 
2933 static int
bind_socket(struct TCP_Server_Info * server)2934 bind_socket(struct TCP_Server_Info *server)
2935 {
2936 	int rc = 0;
2937 	if (server->srcaddr.ss_family != AF_UNSPEC) {
2938 		/* Bind to the specified local IP address */
2939 		struct socket *socket = server->ssocket;
2940 		rc = kernel_bind(socket,
2941 				 (struct sockaddr *) &server->srcaddr,
2942 				 sizeof(server->srcaddr));
2943 		if (rc < 0) {
2944 			struct sockaddr_in *saddr4;
2945 			struct sockaddr_in6 *saddr6;
2946 			saddr4 = (struct sockaddr_in *)&server->srcaddr;
2947 			saddr6 = (struct sockaddr_in6 *)&server->srcaddr;
2948 			if (saddr6->sin6_family == AF_INET6)
2949 				cifs_server_dbg(VFS, "Failed to bind to: %pI6c, error: %d\n",
2950 					 &saddr6->sin6_addr, rc);
2951 			else
2952 				cifs_server_dbg(VFS, "Failed to bind to: %pI4, error: %d\n",
2953 					 &saddr4->sin_addr.s_addr, rc);
2954 		}
2955 	}
2956 	return rc;
2957 }
2958 
2959 static int
ip_rfc1001_connect(struct TCP_Server_Info * server)2960 ip_rfc1001_connect(struct TCP_Server_Info *server)
2961 {
2962 	int rc = 0;
2963 	/*
2964 	 * some servers require RFC1001 sessinit before sending
2965 	 * negprot - BB check reconnection in case where second
2966 	 * sessinit is sent but no second negprot
2967 	 */
2968 	struct rfc1002_session_packet req = {};
2969 	struct smb_hdr *smb_buf = (struct smb_hdr *)&req;
2970 	unsigned int len;
2971 
2972 	req.trailer.session_req.called_len = sizeof(req.trailer.session_req.called_name);
2973 
2974 	if (server->server_RFC1001_name[0] != 0)
2975 		rfc1002mangle(req.trailer.session_req.called_name,
2976 			      server->server_RFC1001_name,
2977 			      RFC1001_NAME_LEN_WITH_NULL);
2978 	else
2979 		rfc1002mangle(req.trailer.session_req.called_name,
2980 			      DEFAULT_CIFS_CALLED_NAME,
2981 			      RFC1001_NAME_LEN_WITH_NULL);
2982 
2983 	req.trailer.session_req.calling_len = sizeof(req.trailer.session_req.calling_name);
2984 
2985 	/* calling name ends in null (byte 16) from old smb convention */
2986 	if (server->workstation_RFC1001_name[0] != 0)
2987 		rfc1002mangle(req.trailer.session_req.calling_name,
2988 			      server->workstation_RFC1001_name,
2989 			      RFC1001_NAME_LEN_WITH_NULL);
2990 	else
2991 		rfc1002mangle(req.trailer.session_req.calling_name,
2992 			      "LINUX_CIFS_CLNT",
2993 			      RFC1001_NAME_LEN_WITH_NULL);
2994 
2995 	/*
2996 	 * As per rfc1002, @len must be the number of bytes that follows the
2997 	 * length field of a rfc1002 session request payload.
2998 	 */
2999 	len = sizeof(req) - offsetof(struct rfc1002_session_packet, trailer.session_req);
3000 
3001 	smb_buf->smb_buf_length = cpu_to_be32((RFC1002_SESSION_REQUEST << 24) | len);
3002 	rc = smb_send(server, smb_buf, len);
3003 	/*
3004 	 * RFC1001 layer in at least one server requires very short break before
3005 	 * negprot presumably because not expecting negprot to follow so fast.
3006 	 * This is a simple solution that works without complicating the code
3007 	 * and causes no significant slowing down on mount for everyone else
3008 	 */
3009 	usleep_range(1000, 2000);
3010 
3011 	return rc;
3012 }
3013 
3014 static int
generic_ip_connect(struct TCP_Server_Info * server)3015 generic_ip_connect(struct TCP_Server_Info *server)
3016 {
3017 	struct sockaddr *saddr;
3018 	struct socket *socket;
3019 	int slen, sfamily;
3020 	__be16 sport;
3021 	int rc = 0;
3022 
3023 	saddr = (struct sockaddr *) &server->dstaddr;
3024 
3025 	if (server->dstaddr.ss_family == AF_INET6) {
3026 		struct sockaddr_in6 *ipv6 = (struct sockaddr_in6 *)&server->dstaddr;
3027 
3028 		sport = ipv6->sin6_port;
3029 		slen = sizeof(struct sockaddr_in6);
3030 		sfamily = AF_INET6;
3031 		cifs_dbg(FYI, "%s: connecting to [%pI6]:%d\n", __func__, &ipv6->sin6_addr,
3032 				ntohs(sport));
3033 	} else {
3034 		struct sockaddr_in *ipv4 = (struct sockaddr_in *)&server->dstaddr;
3035 
3036 		sport = ipv4->sin_port;
3037 		slen = sizeof(struct sockaddr_in);
3038 		sfamily = AF_INET;
3039 		cifs_dbg(FYI, "%s: connecting to %pI4:%d\n", __func__, &ipv4->sin_addr,
3040 				ntohs(sport));
3041 	}
3042 
3043 	if (server->ssocket) {
3044 		socket = server->ssocket;
3045 	} else {
3046 		rc = __sock_create(cifs_net_ns(server), sfamily, SOCK_STREAM,
3047 				   IPPROTO_TCP, &server->ssocket, 1);
3048 		if (rc < 0) {
3049 			cifs_server_dbg(VFS, "Error %d creating socket\n", rc);
3050 			return rc;
3051 		}
3052 
3053 		/* BB other socket options to set KEEPALIVE, NODELAY? */
3054 		cifs_dbg(FYI, "Socket created\n");
3055 		socket = server->ssocket;
3056 		socket->sk->sk_allocation = GFP_NOFS;
3057 		socket->sk->sk_use_task_frag = false;
3058 		if (sfamily == AF_INET6)
3059 			cifs_reclassify_socket6(socket);
3060 		else
3061 			cifs_reclassify_socket4(socket);
3062 	}
3063 
3064 	rc = bind_socket(server);
3065 	if (rc < 0)
3066 		return rc;
3067 
3068 	/*
3069 	 * Eventually check for other socket options to change from
3070 	 * the default. sock_setsockopt not used because it expects
3071 	 * user space buffer
3072 	 */
3073 	socket->sk->sk_rcvtimeo = 7 * HZ;
3074 	socket->sk->sk_sndtimeo = 5 * HZ;
3075 
3076 	/* make the bufsizes depend on wsize/rsize and max requests */
3077 	if (server->noautotune) {
3078 		if (socket->sk->sk_sndbuf < (200 * 1024))
3079 			socket->sk->sk_sndbuf = 200 * 1024;
3080 		if (socket->sk->sk_rcvbuf < (140 * 1024))
3081 			socket->sk->sk_rcvbuf = 140 * 1024;
3082 	}
3083 
3084 	if (server->tcp_nodelay)
3085 		tcp_sock_set_nodelay(socket->sk);
3086 
3087 	cifs_dbg(FYI, "sndbuf %d rcvbuf %d rcvtimeo 0x%lx\n",
3088 		 socket->sk->sk_sndbuf,
3089 		 socket->sk->sk_rcvbuf, socket->sk->sk_rcvtimeo);
3090 
3091 	rc = kernel_connect(socket, saddr, slen,
3092 			    server->noblockcnt ? O_NONBLOCK : 0);
3093 	/*
3094 	 * When mounting SMB root file systems, we do not want to block in
3095 	 * connect. Otherwise bail out and then let cifs_reconnect() perform
3096 	 * reconnect failover - if possible.
3097 	 */
3098 	if (server->noblockcnt && rc == -EINPROGRESS)
3099 		rc = 0;
3100 	if (rc < 0) {
3101 		cifs_dbg(FYI, "Error %d connecting to server\n", rc);
3102 		trace_smb3_connect_err(server->hostname, server->conn_id, &server->dstaddr, rc);
3103 		sock_release(socket);
3104 		server->ssocket = NULL;
3105 		return rc;
3106 	}
3107 	trace_smb3_connect_done(server->hostname, server->conn_id, &server->dstaddr);
3108 	if (sport == htons(RFC1001_PORT))
3109 		rc = ip_rfc1001_connect(server);
3110 
3111 	return rc;
3112 }
3113 
3114 static int
ip_connect(struct TCP_Server_Info * server)3115 ip_connect(struct TCP_Server_Info *server)
3116 {
3117 	__be16 *sport;
3118 	struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&server->dstaddr;
3119 	struct sockaddr_in *addr = (struct sockaddr_in *)&server->dstaddr;
3120 
3121 	if (server->dstaddr.ss_family == AF_INET6)
3122 		sport = &addr6->sin6_port;
3123 	else
3124 		sport = &addr->sin_port;
3125 
3126 	if (*sport == 0) {
3127 		int rc;
3128 
3129 		/* try with 445 port at first */
3130 		*sport = htons(CIFS_PORT);
3131 
3132 		rc = generic_ip_connect(server);
3133 		if (rc >= 0)
3134 			return rc;
3135 
3136 		/* if it failed, try with 139 port */
3137 		*sport = htons(RFC1001_PORT);
3138 	}
3139 
3140 	return generic_ip_connect(server);
3141 }
3142 
3143 #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)3144 void reset_cifs_unix_caps(unsigned int xid, struct cifs_tcon *tcon,
3145 			  struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
3146 {
3147 	/*
3148 	 * If we are reconnecting then should we check to see if
3149 	 * any requested capabilities changed locally e.g. via
3150 	 * remount but we can not do much about it here
3151 	 * if they have (even if we could detect it by the following)
3152 	 * Perhaps we could add a backpointer to array of sb from tcon
3153 	 * or if we change to make all sb to same share the same
3154 	 * sb as NFS - then we only have one backpointer to sb.
3155 	 * What if we wanted to mount the server share twice once with
3156 	 * and once without posixacls or posix paths?
3157 	 */
3158 	__u64 saved_cap = le64_to_cpu(tcon->fsUnixInfo.Capability);
3159 
3160 	if (ctx && ctx->no_linux_ext) {
3161 		tcon->fsUnixInfo.Capability = 0;
3162 		tcon->unix_ext = 0; /* Unix Extensions disabled */
3163 		cifs_dbg(FYI, "Linux protocol extensions disabled\n");
3164 		return;
3165 	} else if (ctx)
3166 		tcon->unix_ext = 1; /* Unix Extensions supported */
3167 
3168 	if (!tcon->unix_ext) {
3169 		cifs_dbg(FYI, "Unix extensions disabled so not set on reconnect\n");
3170 		return;
3171 	}
3172 
3173 	if (!CIFSSMBQFSUnixInfo(xid, tcon)) {
3174 		__u64 cap = le64_to_cpu(tcon->fsUnixInfo.Capability);
3175 		cifs_dbg(FYI, "unix caps which server supports %lld\n", cap);
3176 		/*
3177 		 * check for reconnect case in which we do not
3178 		 * want to change the mount behavior if we can avoid it
3179 		 */
3180 		if (ctx == NULL) {
3181 			/*
3182 			 * turn off POSIX ACL and PATHNAMES if not set
3183 			 * originally at mount time
3184 			 */
3185 			if ((saved_cap & CIFS_UNIX_POSIX_ACL_CAP) == 0)
3186 				cap &= ~CIFS_UNIX_POSIX_ACL_CAP;
3187 			if ((saved_cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) == 0) {
3188 				if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP)
3189 					cifs_dbg(VFS, "POSIXPATH support change\n");
3190 				cap &= ~CIFS_UNIX_POSIX_PATHNAMES_CAP;
3191 			} else if ((cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) == 0) {
3192 				cifs_dbg(VFS, "possible reconnect error\n");
3193 				cifs_dbg(VFS, "server disabled POSIX path support\n");
3194 			}
3195 		}
3196 
3197 		if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)
3198 			cifs_dbg(VFS, "per-share encryption not supported yet\n");
3199 
3200 		cap &= CIFS_UNIX_CAP_MASK;
3201 		if (ctx && ctx->no_psx_acl)
3202 			cap &= ~CIFS_UNIX_POSIX_ACL_CAP;
3203 		else if (CIFS_UNIX_POSIX_ACL_CAP & cap) {
3204 			cifs_dbg(FYI, "negotiated posix acl support\n");
3205 			if (cifs_sb)
3206 				cifs_sb->mnt_cifs_flags |=
3207 					CIFS_MOUNT_POSIXACL;
3208 		}
3209 
3210 		if (ctx && ctx->posix_paths == 0)
3211 			cap &= ~CIFS_UNIX_POSIX_PATHNAMES_CAP;
3212 		else if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) {
3213 			cifs_dbg(FYI, "negotiate posix pathnames\n");
3214 			if (cifs_sb)
3215 				cifs_sb->mnt_cifs_flags |=
3216 					CIFS_MOUNT_POSIX_PATHS;
3217 		}
3218 
3219 		cifs_dbg(FYI, "Negotiate caps 0x%x\n", (int)cap);
3220 #ifdef CONFIG_CIFS_DEBUG2
3221 		if (cap & CIFS_UNIX_FCNTL_CAP)
3222 			cifs_dbg(FYI, "FCNTL cap\n");
3223 		if (cap & CIFS_UNIX_EXTATTR_CAP)
3224 			cifs_dbg(FYI, "EXTATTR cap\n");
3225 		if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP)
3226 			cifs_dbg(FYI, "POSIX path cap\n");
3227 		if (cap & CIFS_UNIX_XATTR_CAP)
3228 			cifs_dbg(FYI, "XATTR cap\n");
3229 		if (cap & CIFS_UNIX_POSIX_ACL_CAP)
3230 			cifs_dbg(FYI, "POSIX ACL cap\n");
3231 		if (cap & CIFS_UNIX_LARGE_READ_CAP)
3232 			cifs_dbg(FYI, "very large read cap\n");
3233 		if (cap & CIFS_UNIX_LARGE_WRITE_CAP)
3234 			cifs_dbg(FYI, "very large write cap\n");
3235 		if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_CAP)
3236 			cifs_dbg(FYI, "transport encryption cap\n");
3237 		if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)
3238 			cifs_dbg(FYI, "mandatory transport encryption cap\n");
3239 #endif /* CIFS_DEBUG2 */
3240 		if (CIFSSMBSetFSUnixInfo(xid, tcon, cap)) {
3241 			if (ctx == NULL)
3242 				cifs_dbg(FYI, "resetting capabilities failed\n");
3243 			else
3244 				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");
3245 
3246 		}
3247 	}
3248 }
3249 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
3250 
cifs_setup_cifs_sb(struct cifs_sb_info * cifs_sb)3251 int cifs_setup_cifs_sb(struct cifs_sb_info *cifs_sb)
3252 {
3253 	struct smb3_fs_context *ctx = cifs_sb->ctx;
3254 
3255 	INIT_DELAYED_WORK(&cifs_sb->prune_tlinks, cifs_prune_tlinks);
3256 
3257 	spin_lock_init(&cifs_sb->tlink_tree_lock);
3258 	cifs_sb->tlink_tree = RB_ROOT;
3259 
3260 	cifs_dbg(FYI, "file mode: %04ho  dir mode: %04ho\n",
3261 		 ctx->file_mode, ctx->dir_mode);
3262 
3263 	/* this is needed for ASCII cp to Unicode converts */
3264 	if (ctx->iocharset == NULL) {
3265 		/* load_nls_default cannot return null */
3266 		cifs_sb->local_nls = load_nls_default();
3267 	} else {
3268 		cifs_sb->local_nls = load_nls(ctx->iocharset);
3269 		if (cifs_sb->local_nls == NULL) {
3270 			cifs_dbg(VFS, "CIFS mount error: iocharset %s not found\n",
3271 				 ctx->iocharset);
3272 			return -ELIBACC;
3273 		}
3274 	}
3275 	ctx->local_nls = cifs_sb->local_nls;
3276 
3277 	smb3_update_mnt_flags(cifs_sb);
3278 
3279 	if (ctx->direct_io)
3280 		cifs_dbg(FYI, "mounting share using direct i/o\n");
3281 	if (ctx->cache_ro) {
3282 		cifs_dbg(VFS, "mounting share with read only caching. Ensure that the share will not be modified while in use.\n");
3283 		cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_RO_CACHE;
3284 	} else if (ctx->cache_rw) {
3285 		cifs_dbg(VFS, "mounting share in single client RW caching mode. Ensure that no other systems will be accessing the share.\n");
3286 		cifs_sb->mnt_cifs_flags |= (CIFS_MOUNT_RO_CACHE |
3287 					    CIFS_MOUNT_RW_CACHE);
3288 	}
3289 
3290 	if ((ctx->cifs_acl) && (ctx->dynperm))
3291 		cifs_dbg(VFS, "mount option dynperm ignored if cifsacl mount option supported\n");
3292 
3293 	if (ctx->prepath) {
3294 		cifs_sb->prepath = kstrdup(ctx->prepath, GFP_KERNEL);
3295 		if (cifs_sb->prepath == NULL)
3296 			return -ENOMEM;
3297 		cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
3298 	}
3299 
3300 	return 0;
3301 }
3302 
3303 /* Release all succeed connections */
cifs_mount_put_conns(struct cifs_mount_ctx * mnt_ctx)3304 void cifs_mount_put_conns(struct cifs_mount_ctx *mnt_ctx)
3305 {
3306 	int rc = 0;
3307 
3308 	if (mnt_ctx->tcon)
3309 		cifs_put_tcon(mnt_ctx->tcon);
3310 	else if (mnt_ctx->ses)
3311 		cifs_put_smb_ses(mnt_ctx->ses);
3312 	else if (mnt_ctx->server)
3313 		cifs_put_tcp_session(mnt_ctx->server, 0);
3314 	mnt_ctx->cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_POSIX_PATHS;
3315 	free_xid(mnt_ctx->xid);
3316 }
3317 
cifs_mount_get_session(struct cifs_mount_ctx * mnt_ctx)3318 int cifs_mount_get_session(struct cifs_mount_ctx *mnt_ctx)
3319 {
3320 	struct TCP_Server_Info *server = NULL;
3321 	struct smb3_fs_context *ctx;
3322 	struct cifs_ses *ses = NULL;
3323 	unsigned int xid;
3324 	int rc = 0;
3325 
3326 	xid = get_xid();
3327 
3328 	if (WARN_ON_ONCE(!mnt_ctx || !mnt_ctx->fs_ctx)) {
3329 		rc = -EINVAL;
3330 		goto out;
3331 	}
3332 	ctx = mnt_ctx->fs_ctx;
3333 
3334 	/* get a reference to a tcp session */
3335 	server = cifs_get_tcp_session(ctx, NULL);
3336 	if (IS_ERR(server)) {
3337 		rc = PTR_ERR(server);
3338 		server = NULL;
3339 		goto out;
3340 	}
3341 
3342 	/* get a reference to a SMB session */
3343 	ses = cifs_get_smb_ses(server, ctx);
3344 	if (IS_ERR(ses)) {
3345 		rc = PTR_ERR(ses);
3346 		ses = NULL;
3347 		goto out;
3348 	}
3349 
3350 	if ((ctx->persistent == true) && (!(ses->server->capabilities &
3351 					    SMB2_GLOBAL_CAP_PERSISTENT_HANDLES))) {
3352 		cifs_server_dbg(VFS, "persistent handles not supported by server\n");
3353 		rc = -EOPNOTSUPP;
3354 	}
3355 
3356 out:
3357 	mnt_ctx->xid = xid;
3358 	mnt_ctx->server = server;
3359 	mnt_ctx->ses = ses;
3360 	mnt_ctx->tcon = NULL;
3361 
3362 	return rc;
3363 }
3364 
cifs_mount_get_tcon(struct cifs_mount_ctx * mnt_ctx)3365 int cifs_mount_get_tcon(struct cifs_mount_ctx *mnt_ctx)
3366 {
3367 	struct TCP_Server_Info *server;
3368 	struct cifs_sb_info *cifs_sb;
3369 	struct smb3_fs_context *ctx;
3370 	struct cifs_tcon *tcon = NULL;
3371 	int rc = 0;
3372 
3373 	if (WARN_ON_ONCE(!mnt_ctx || !mnt_ctx->server || !mnt_ctx->ses || !mnt_ctx->fs_ctx ||
3374 			 !mnt_ctx->cifs_sb)) {
3375 		rc = -EINVAL;
3376 		goto out;
3377 	}
3378 	server = mnt_ctx->server;
3379 	ctx = mnt_ctx->fs_ctx;
3380 	cifs_sb = mnt_ctx->cifs_sb;
3381 
3382 	/* search for existing tcon to this server share */
3383 	tcon = cifs_get_tcon(mnt_ctx->ses, ctx);
3384 	if (IS_ERR(tcon)) {
3385 		rc = PTR_ERR(tcon);
3386 		tcon = NULL;
3387 		goto out;
3388 	}
3389 
3390 	/* if new SMB3.11 POSIX extensions are supported do not remap / and \ */
3391 	if (tcon->posix_extensions)
3392 		cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_POSIX_PATHS;
3393 
3394 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
3395 	/* tell server which Unix caps we support */
3396 	if (cap_unix(tcon->ses)) {
3397 		/*
3398 		 * reset of caps checks mount to see if unix extensions disabled
3399 		 * for just this mount.
3400 		 */
3401 		reset_cifs_unix_caps(mnt_ctx->xid, tcon, cifs_sb, ctx);
3402 		spin_lock(&tcon->ses->server->srv_lock);
3403 		if ((tcon->ses->server->tcpStatus == CifsNeedReconnect) &&
3404 		    (le64_to_cpu(tcon->fsUnixInfo.Capability) &
3405 		     CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)) {
3406 			spin_unlock(&tcon->ses->server->srv_lock);
3407 			rc = -EACCES;
3408 			goto out;
3409 		}
3410 		spin_unlock(&tcon->ses->server->srv_lock);
3411 	} else
3412 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
3413 		tcon->unix_ext = 0; /* server does not support them */
3414 
3415 	/* do not care if a following call succeed - informational */
3416 	if (!tcon->pipe && server->ops->qfs_tcon) {
3417 		server->ops->qfs_tcon(mnt_ctx->xid, tcon, cifs_sb);
3418 		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RO_CACHE) {
3419 			if (tcon->fsDevInfo.DeviceCharacteristics &
3420 			    cpu_to_le32(FILE_READ_ONLY_DEVICE))
3421 				cifs_dbg(VFS, "mounted to read only share\n");
3422 			else if ((cifs_sb->mnt_cifs_flags &
3423 				  CIFS_MOUNT_RW_CACHE) == 0)
3424 				cifs_dbg(VFS, "read only mount of RW share\n");
3425 			/* no need to log a RW mount of a typical RW share */
3426 		}
3427 	}
3428 
3429 	/*
3430 	 * Clamp the rsize/wsize mount arguments if they are too big for the server
3431 	 * and set the rsize/wsize to the negotiated values if not passed in by
3432 	 * the user on mount
3433 	 */
3434 	if ((cifs_sb->ctx->wsize == 0) ||
3435 	    (cifs_sb->ctx->wsize > server->ops->negotiate_wsize(tcon, ctx))) {
3436 		cifs_sb->ctx->wsize =
3437 			round_down(server->ops->negotiate_wsize(tcon, ctx), PAGE_SIZE);
3438 		/*
3439 		 * in the very unlikely event that the server sent a max write size under PAGE_SIZE,
3440 		 * (which would get rounded down to 0) then reset wsize to absolute minimum eg 4096
3441 		 */
3442 		if (cifs_sb->ctx->wsize == 0) {
3443 			cifs_sb->ctx->wsize = PAGE_SIZE;
3444 			cifs_dbg(VFS, "wsize too small, reset to minimum ie PAGE_SIZE, usually 4096\n");
3445 		}
3446 	}
3447 	if ((cifs_sb->ctx->rsize == 0) ||
3448 	    (cifs_sb->ctx->rsize > server->ops->negotiate_rsize(tcon, ctx)))
3449 		cifs_sb->ctx->rsize = server->ops->negotiate_rsize(tcon, ctx);
3450 
3451 	/*
3452 	 * The cookie is initialized from volume info returned above.
3453 	 * Inside cifs_fscache_get_super_cookie it checks
3454 	 * that we do not get super cookie twice.
3455 	 */
3456 	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_FSCACHE)
3457 		cifs_fscache_get_super_cookie(tcon);
3458 
3459 out:
3460 	mnt_ctx->tcon = tcon;
3461 	return rc;
3462 }
3463 
mount_setup_tlink(struct cifs_sb_info * cifs_sb,struct cifs_ses * ses,struct cifs_tcon * tcon)3464 static int mount_setup_tlink(struct cifs_sb_info *cifs_sb, struct cifs_ses *ses,
3465 			     struct cifs_tcon *tcon)
3466 {
3467 	struct tcon_link *tlink;
3468 
3469 	/* hang the tcon off of the superblock */
3470 	tlink = kzalloc(sizeof(*tlink), GFP_KERNEL);
3471 	if (tlink == NULL)
3472 		return -ENOMEM;
3473 
3474 	tlink->tl_uid = ses->linux_uid;
3475 	tlink->tl_tcon = tcon;
3476 	tlink->tl_time = jiffies;
3477 	set_bit(TCON_LINK_MASTER, &tlink->tl_flags);
3478 	set_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
3479 
3480 	cifs_sb->master_tlink = tlink;
3481 	spin_lock(&cifs_sb->tlink_tree_lock);
3482 	tlink_rb_insert(&cifs_sb->tlink_tree, tlink);
3483 	spin_unlock(&cifs_sb->tlink_tree_lock);
3484 
3485 	queue_delayed_work(cifsiod_wq, &cifs_sb->prune_tlinks,
3486 				TLINK_IDLE_EXPIRE);
3487 	return 0;
3488 }
3489 
3490 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)3491 cifs_are_all_path_components_accessible(struct TCP_Server_Info *server,
3492 					unsigned int xid,
3493 					struct cifs_tcon *tcon,
3494 					struct cifs_sb_info *cifs_sb,
3495 					char *full_path,
3496 					int added_treename)
3497 {
3498 	int rc;
3499 	char *s;
3500 	char sep, tmp;
3501 	int skip = added_treename ? 1 : 0;
3502 
3503 	sep = CIFS_DIR_SEP(cifs_sb);
3504 	s = full_path;
3505 
3506 	rc = server->ops->is_path_accessible(xid, tcon, cifs_sb, "");
3507 	while (rc == 0) {
3508 		/* skip separators */
3509 		while (*s == sep)
3510 			s++;
3511 		if (!*s)
3512 			break;
3513 		/* next separator */
3514 		while (*s && *s != sep)
3515 			s++;
3516 		/*
3517 		 * if the treename is added, we then have to skip the first
3518 		 * part within the separators
3519 		 */
3520 		if (skip) {
3521 			skip = 0;
3522 			continue;
3523 		}
3524 		/*
3525 		 * temporarily null-terminate the path at the end of
3526 		 * the current component
3527 		 */
3528 		tmp = *s;
3529 		*s = 0;
3530 		rc = server->ops->is_path_accessible(xid, tcon, cifs_sb,
3531 						     full_path);
3532 		*s = tmp;
3533 	}
3534 	return rc;
3535 }
3536 
3537 /*
3538  * Check if path is remote (i.e. a DFS share).
3539  *
3540  * Return -EREMOTE if it is, otherwise 0 or -errno.
3541  */
cifs_is_path_remote(struct cifs_mount_ctx * mnt_ctx)3542 int cifs_is_path_remote(struct cifs_mount_ctx *mnt_ctx)
3543 {
3544 	int rc;
3545 	struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3546 	struct TCP_Server_Info *server = mnt_ctx->server;
3547 	unsigned int xid = mnt_ctx->xid;
3548 	struct cifs_tcon *tcon = mnt_ctx->tcon;
3549 	struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
3550 	char *full_path;
3551 
3552 	if (!server->ops->is_path_accessible)
3553 		return -EOPNOTSUPP;
3554 
3555 	/*
3556 	 * cifs_build_path_to_root works only when we have a valid tcon
3557 	 */
3558 	full_path = cifs_build_path_to_root(ctx, cifs_sb, tcon,
3559 					    tcon->Flags & SMB_SHARE_IS_IN_DFS);
3560 	if (full_path == NULL)
3561 		return -ENOMEM;
3562 
3563 	cifs_dbg(FYI, "%s: full_path: %s\n", __func__, full_path);
3564 
3565 	rc = server->ops->is_path_accessible(xid, tcon, cifs_sb,
3566 					     full_path);
3567 	if (rc != 0 && rc != -EREMOTE)
3568 		goto out;
3569 
3570 	if (rc != -EREMOTE) {
3571 		rc = cifs_are_all_path_components_accessible(server, xid, tcon,
3572 			cifs_sb, full_path, tcon->Flags & SMB_SHARE_IS_IN_DFS);
3573 		if (rc != 0) {
3574 			cifs_server_dbg(VFS, "cannot query dirs between root and final path, enabling CIFS_MOUNT_USE_PREFIX_PATH\n");
3575 			cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
3576 			rc = 0;
3577 		}
3578 	}
3579 
3580 out:
3581 	kfree(full_path);
3582 	return rc;
3583 }
3584 
3585 #ifdef CONFIG_CIFS_DFS_UPCALL
cifs_mount(struct cifs_sb_info * cifs_sb,struct smb3_fs_context * ctx)3586 int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
3587 {
3588 	struct cifs_mount_ctx mnt_ctx = { .cifs_sb = cifs_sb, .fs_ctx = ctx, };
3589 	bool isdfs;
3590 	int rc;
3591 
3592 	INIT_LIST_HEAD(&mnt_ctx.dfs_ses_list);
3593 
3594 	rc = dfs_mount_share(&mnt_ctx, &isdfs);
3595 	if (rc)
3596 		goto error;
3597 	if (!isdfs)
3598 		goto out;
3599 
3600 	/*
3601 	 * After reconnecting to a different server, unique ids won't match anymore, so we disable
3602 	 * serverino. This prevents dentry revalidation to think the dentry are stale (ESTALE).
3603 	 */
3604 	cifs_autodisable_serverino(cifs_sb);
3605 	/*
3606 	 * Force the use of prefix path to support failover on DFS paths that resolve to targets
3607 	 * that have different prefix paths.
3608 	 */
3609 	cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
3610 	kfree(cifs_sb->prepath);
3611 	cifs_sb->prepath = ctx->prepath;
3612 	ctx->prepath = NULL;
3613 
3614 out:
3615 	cifs_try_adding_channels(mnt_ctx.ses);
3616 	rc = mount_setup_tlink(cifs_sb, mnt_ctx.ses, mnt_ctx.tcon);
3617 	if (rc)
3618 		goto error;
3619 
3620 	free_xid(mnt_ctx.xid);
3621 	return rc;
3622 
3623 error:
3624 	dfs_put_root_smb_sessions(&mnt_ctx.dfs_ses_list);
3625 	cifs_mount_put_conns(&mnt_ctx);
3626 	return rc;
3627 }
3628 #else
cifs_mount(struct cifs_sb_info * cifs_sb,struct smb3_fs_context * ctx)3629 int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
3630 {
3631 	int rc = 0;
3632 	struct cifs_mount_ctx mnt_ctx = { .cifs_sb = cifs_sb, .fs_ctx = ctx, };
3633 
3634 	rc = cifs_mount_get_session(&mnt_ctx);
3635 	if (rc)
3636 		goto error;
3637 
3638 	rc = cifs_mount_get_tcon(&mnt_ctx);
3639 	if (rc)
3640 		goto error;
3641 
3642 	rc = cifs_is_path_remote(&mnt_ctx);
3643 	if (rc == -EREMOTE)
3644 		rc = -EOPNOTSUPP;
3645 	if (rc)
3646 		goto error;
3647 
3648 	rc = mount_setup_tlink(cifs_sb, mnt_ctx.ses, mnt_ctx.tcon);
3649 	if (rc)
3650 		goto error;
3651 
3652 	free_xid(mnt_ctx.xid);
3653 	return rc;
3654 
3655 error:
3656 	cifs_mount_put_conns(&mnt_ctx);
3657 	return rc;
3658 }
3659 #endif
3660 
3661 /*
3662  * Issue a TREE_CONNECT request.
3663  */
3664 int
CIFSTCon(const unsigned int xid,struct cifs_ses * ses,const char * tree,struct cifs_tcon * tcon,const struct nls_table * nls_codepage)3665 CIFSTCon(const unsigned int xid, struct cifs_ses *ses,
3666 	 const char *tree, struct cifs_tcon *tcon,
3667 	 const struct nls_table *nls_codepage)
3668 {
3669 	struct smb_hdr *smb_buffer;
3670 	struct smb_hdr *smb_buffer_response;
3671 	TCONX_REQ *pSMB;
3672 	TCONX_RSP *pSMBr;
3673 	unsigned char *bcc_ptr;
3674 	int rc = 0;
3675 	int length;
3676 	__u16 bytes_left, count;
3677 
3678 	if (ses == NULL)
3679 		return -EIO;
3680 
3681 	smb_buffer = cifs_buf_get();
3682 	if (smb_buffer == NULL)
3683 		return -ENOMEM;
3684 
3685 	smb_buffer_response = smb_buffer;
3686 
3687 	header_assemble(smb_buffer, SMB_COM_TREE_CONNECT_ANDX,
3688 			NULL /*no tid */ , 4 /*wct */ );
3689 
3690 	smb_buffer->Mid = get_next_mid(ses->server);
3691 	smb_buffer->Uid = ses->Suid;
3692 	pSMB = (TCONX_REQ *) smb_buffer;
3693 	pSMBr = (TCONX_RSP *) smb_buffer_response;
3694 
3695 	pSMB->AndXCommand = 0xFF;
3696 	pSMB->Flags = cpu_to_le16(TCON_EXTENDED_SECINFO);
3697 	bcc_ptr = &pSMB->Password[0];
3698 
3699 	pSMB->PasswordLength = cpu_to_le16(1);	/* minimum */
3700 	*bcc_ptr = 0; /* password is null byte */
3701 	bcc_ptr++;              /* skip password */
3702 	/* already aligned so no need to do it below */
3703 
3704 	if (ses->server->sign)
3705 		smb_buffer->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
3706 
3707 	if (ses->capabilities & CAP_STATUS32) {
3708 		smb_buffer->Flags2 |= SMBFLG2_ERR_STATUS;
3709 	}
3710 	if (ses->capabilities & CAP_DFS) {
3711 		smb_buffer->Flags2 |= SMBFLG2_DFS;
3712 	}
3713 	if (ses->capabilities & CAP_UNICODE) {
3714 		smb_buffer->Flags2 |= SMBFLG2_UNICODE;
3715 		length =
3716 		    cifs_strtoUTF16((__le16 *) bcc_ptr, tree,
3717 			6 /* max utf8 char length in bytes */ *
3718 			(/* server len*/ + 256 /* share len */), nls_codepage);
3719 		bcc_ptr += 2 * length;	/* convert num 16 bit words to bytes */
3720 		bcc_ptr += 2;	/* skip trailing null */
3721 	} else {		/* ASCII */
3722 		strcpy(bcc_ptr, tree);
3723 		bcc_ptr += strlen(tree) + 1;
3724 	}
3725 	strcpy(bcc_ptr, "?????");
3726 	bcc_ptr += strlen("?????");
3727 	bcc_ptr += 1;
3728 	count = bcc_ptr - &pSMB->Password[0];
3729 	be32_add_cpu(&pSMB->hdr.smb_buf_length, count);
3730 	pSMB->ByteCount = cpu_to_le16(count);
3731 
3732 	rc = SendReceive(xid, ses, smb_buffer, smb_buffer_response, &length,
3733 			 0);
3734 
3735 	/* above now done in SendReceive */
3736 	if (rc == 0) {
3737 		bool is_unicode;
3738 
3739 		tcon->tid = smb_buffer_response->Tid;
3740 		bcc_ptr = pByteArea(smb_buffer_response);
3741 		bytes_left = get_bcc(smb_buffer_response);
3742 		length = strnlen(bcc_ptr, bytes_left - 2);
3743 		if (smb_buffer->Flags2 & SMBFLG2_UNICODE)
3744 			is_unicode = true;
3745 		else
3746 			is_unicode = false;
3747 
3748 
3749 		/* skip service field (NB: this field is always ASCII) */
3750 		if (length == 3) {
3751 			if ((bcc_ptr[0] == 'I') && (bcc_ptr[1] == 'P') &&
3752 			    (bcc_ptr[2] == 'C')) {
3753 				cifs_dbg(FYI, "IPC connection\n");
3754 				tcon->ipc = true;
3755 				tcon->pipe = true;
3756 			}
3757 		} else if (length == 2) {
3758 			if ((bcc_ptr[0] == 'A') && (bcc_ptr[1] == ':')) {
3759 				/* the most common case */
3760 				cifs_dbg(FYI, "disk share connection\n");
3761 			}
3762 		}
3763 		bcc_ptr += length + 1;
3764 		bytes_left -= (length + 1);
3765 		strscpy(tcon->tree_name, tree, sizeof(tcon->tree_name));
3766 
3767 		/* mostly informational -- no need to fail on error here */
3768 		kfree(tcon->nativeFileSystem);
3769 		tcon->nativeFileSystem = cifs_strndup_from_utf16(bcc_ptr,
3770 						      bytes_left, is_unicode,
3771 						      nls_codepage);
3772 
3773 		cifs_dbg(FYI, "nativeFileSystem=%s\n", tcon->nativeFileSystem);
3774 
3775 		if ((smb_buffer_response->WordCount == 3) ||
3776 			 (smb_buffer_response->WordCount == 7))
3777 			/* field is in same location */
3778 			tcon->Flags = le16_to_cpu(pSMBr->OptionalSupport);
3779 		else
3780 			tcon->Flags = 0;
3781 		cifs_dbg(FYI, "Tcon flags: 0x%x\n", tcon->Flags);
3782 	}
3783 
3784 	cifs_buf_release(smb_buffer);
3785 	return rc;
3786 }
3787 
delayed_free(struct rcu_head * p)3788 static void delayed_free(struct rcu_head *p)
3789 {
3790 	struct cifs_sb_info *cifs_sb = container_of(p, struct cifs_sb_info, rcu);
3791 
3792 	unload_nls(cifs_sb->local_nls);
3793 	smb3_cleanup_fs_context(cifs_sb->ctx);
3794 	kfree(cifs_sb);
3795 }
3796 
3797 void
cifs_umount(struct cifs_sb_info * cifs_sb)3798 cifs_umount(struct cifs_sb_info *cifs_sb)
3799 {
3800 	struct rb_root *root = &cifs_sb->tlink_tree;
3801 	struct rb_node *node;
3802 	struct tcon_link *tlink;
3803 
3804 	cancel_delayed_work_sync(&cifs_sb->prune_tlinks);
3805 
3806 	spin_lock(&cifs_sb->tlink_tree_lock);
3807 	while ((node = rb_first(root))) {
3808 		tlink = rb_entry(node, struct tcon_link, tl_rbnode);
3809 		cifs_get_tlink(tlink);
3810 		clear_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
3811 		rb_erase(node, root);
3812 
3813 		spin_unlock(&cifs_sb->tlink_tree_lock);
3814 		cifs_put_tlink(tlink);
3815 		spin_lock(&cifs_sb->tlink_tree_lock);
3816 	}
3817 	spin_unlock(&cifs_sb->tlink_tree_lock);
3818 
3819 	kfree(cifs_sb->prepath);
3820 	call_rcu(&cifs_sb->rcu, delayed_free);
3821 }
3822 
3823 int
cifs_negotiate_protocol(const unsigned int xid,struct cifs_ses * ses,struct TCP_Server_Info * server)3824 cifs_negotiate_protocol(const unsigned int xid, struct cifs_ses *ses,
3825 			struct TCP_Server_Info *server)
3826 {
3827 	int rc = 0;
3828 
3829 	if (!server->ops->need_neg || !server->ops->negotiate)
3830 		return -ENOSYS;
3831 
3832 	/* only send once per connect */
3833 	spin_lock(&server->srv_lock);
3834 	if (server->tcpStatus != CifsGood &&
3835 	    server->tcpStatus != CifsNew &&
3836 	    server->tcpStatus != CifsNeedNegotiate) {
3837 		spin_unlock(&server->srv_lock);
3838 		return -EHOSTDOWN;
3839 	}
3840 
3841 	if (!server->ops->need_neg(server) &&
3842 	    server->tcpStatus == CifsGood) {
3843 		spin_unlock(&server->srv_lock);
3844 		return 0;
3845 	}
3846 
3847 	server->tcpStatus = CifsInNegotiate;
3848 	spin_unlock(&server->srv_lock);
3849 
3850 	rc = server->ops->negotiate(xid, ses, server);
3851 	if (rc == 0) {
3852 		spin_lock(&server->srv_lock);
3853 		if (server->tcpStatus == CifsInNegotiate)
3854 			server->tcpStatus = CifsGood;
3855 		else
3856 			rc = -EHOSTDOWN;
3857 		spin_unlock(&server->srv_lock);
3858 	} else {
3859 		spin_lock(&server->srv_lock);
3860 		if (server->tcpStatus == CifsInNegotiate)
3861 			server->tcpStatus = CifsNeedNegotiate;
3862 		spin_unlock(&server->srv_lock);
3863 	}
3864 
3865 	return rc;
3866 }
3867 
3868 int
cifs_setup_session(const unsigned int xid,struct cifs_ses * ses,struct TCP_Server_Info * server,struct nls_table * nls_info)3869 cifs_setup_session(const unsigned int xid, struct cifs_ses *ses,
3870 		   struct TCP_Server_Info *server,
3871 		   struct nls_table *nls_info)
3872 {
3873 	int rc = -ENOSYS;
3874 	struct TCP_Server_Info *pserver = SERVER_IS_CHAN(server) ? server->primary_server : server;
3875 	struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&pserver->dstaddr;
3876 	struct sockaddr_in *addr = (struct sockaddr_in *)&pserver->dstaddr;
3877 	bool is_binding = false;
3878 
3879 	spin_lock(&ses->ses_lock);
3880 	cifs_dbg(FYI, "%s: channel connect bitmap: 0x%lx\n",
3881 		 __func__, ses->chans_need_reconnect);
3882 
3883 	if (ses->ses_status != SES_GOOD &&
3884 	    ses->ses_status != SES_NEW &&
3885 	    ses->ses_status != SES_NEED_RECON) {
3886 		spin_unlock(&ses->ses_lock);
3887 		return -EHOSTDOWN;
3888 	}
3889 
3890 	/* only send once per connect */
3891 	spin_lock(&ses->chan_lock);
3892 	if (CIFS_ALL_CHANS_GOOD(ses)) {
3893 		if (ses->ses_status == SES_NEED_RECON)
3894 			ses->ses_status = SES_GOOD;
3895 		spin_unlock(&ses->chan_lock);
3896 		spin_unlock(&ses->ses_lock);
3897 		return 0;
3898 	}
3899 
3900 	cifs_chan_set_in_reconnect(ses, server);
3901 	is_binding = !CIFS_ALL_CHANS_NEED_RECONNECT(ses);
3902 	spin_unlock(&ses->chan_lock);
3903 
3904 	if (!is_binding) {
3905 		ses->ses_status = SES_IN_SETUP;
3906 
3907 		/* force iface_list refresh */
3908 		ses->iface_last_update = 0;
3909 	}
3910 	spin_unlock(&ses->ses_lock);
3911 
3912 	/* update ses ip_addr only for primary chan */
3913 	if (server == pserver) {
3914 		if (server->dstaddr.ss_family == AF_INET6)
3915 			scnprintf(ses->ip_addr, sizeof(ses->ip_addr), "%pI6", &addr6->sin6_addr);
3916 		else
3917 			scnprintf(ses->ip_addr, sizeof(ses->ip_addr), "%pI4", &addr->sin_addr);
3918 	}
3919 
3920 	if (!is_binding) {
3921 		ses->capabilities = server->capabilities;
3922 		if (!linuxExtEnabled)
3923 			ses->capabilities &= (~server->vals->cap_unix);
3924 
3925 		if (ses->auth_key.response) {
3926 			cifs_dbg(FYI, "Free previous auth_key.response = %p\n",
3927 				 ses->auth_key.response);
3928 			kfree_sensitive(ses->auth_key.response);
3929 			ses->auth_key.response = NULL;
3930 			ses->auth_key.len = 0;
3931 		}
3932 	}
3933 
3934 	cifs_dbg(FYI, "Security Mode: 0x%x Capabilities: 0x%x TimeAdjust: %d\n",
3935 		 server->sec_mode, server->capabilities, server->timeAdj);
3936 
3937 	if (server->ops->sess_setup)
3938 		rc = server->ops->sess_setup(xid, ses, server, nls_info);
3939 
3940 	if (rc) {
3941 		cifs_server_dbg(VFS, "Send error in SessSetup = %d\n", rc);
3942 		spin_lock(&ses->ses_lock);
3943 		if (ses->ses_status == SES_IN_SETUP)
3944 			ses->ses_status = SES_NEED_RECON;
3945 		spin_lock(&ses->chan_lock);
3946 		cifs_chan_clear_in_reconnect(ses, server);
3947 		spin_unlock(&ses->chan_lock);
3948 		spin_unlock(&ses->ses_lock);
3949 	} else {
3950 		spin_lock(&ses->ses_lock);
3951 		if (ses->ses_status == SES_IN_SETUP)
3952 			ses->ses_status = SES_GOOD;
3953 		spin_lock(&ses->chan_lock);
3954 		cifs_chan_clear_in_reconnect(ses, server);
3955 		cifs_chan_clear_need_reconnect(ses, server);
3956 		spin_unlock(&ses->chan_lock);
3957 		spin_unlock(&ses->ses_lock);
3958 	}
3959 
3960 	return rc;
3961 }
3962 
3963 static int
cifs_set_vol_auth(struct smb3_fs_context * ctx,struct cifs_ses * ses)3964 cifs_set_vol_auth(struct smb3_fs_context *ctx, struct cifs_ses *ses)
3965 {
3966 	ctx->sectype = ses->sectype;
3967 
3968 	/* krb5 is special, since we don't need username or pw */
3969 	if (ctx->sectype == Kerberos)
3970 		return 0;
3971 
3972 	return cifs_set_cifscreds(ctx, ses);
3973 }
3974 
3975 static struct cifs_tcon *
cifs_construct_tcon(struct cifs_sb_info * cifs_sb,kuid_t fsuid)3976 cifs_construct_tcon(struct cifs_sb_info *cifs_sb, kuid_t fsuid)
3977 {
3978 	int rc;
3979 	struct cifs_tcon *master_tcon = cifs_sb_master_tcon(cifs_sb);
3980 	struct cifs_ses *ses;
3981 	struct cifs_tcon *tcon = NULL;
3982 	struct smb3_fs_context *ctx;
3983 
3984 	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
3985 	if (ctx == NULL)
3986 		return ERR_PTR(-ENOMEM);
3987 
3988 	ctx->local_nls = cifs_sb->local_nls;
3989 	ctx->linux_uid = fsuid;
3990 	ctx->cred_uid = fsuid;
3991 	ctx->UNC = master_tcon->tree_name;
3992 	ctx->retry = master_tcon->retry;
3993 	ctx->nocase = master_tcon->nocase;
3994 	ctx->nohandlecache = master_tcon->nohandlecache;
3995 	ctx->local_lease = master_tcon->local_lease;
3996 	ctx->no_lease = master_tcon->no_lease;
3997 	ctx->resilient = master_tcon->use_resilient;
3998 	ctx->persistent = master_tcon->use_persistent;
3999 	ctx->handle_timeout = master_tcon->handle_timeout;
4000 	ctx->no_linux_ext = !master_tcon->unix_ext;
4001 	ctx->linux_ext = master_tcon->posix_extensions;
4002 	ctx->sectype = master_tcon->ses->sectype;
4003 	ctx->sign = master_tcon->ses->sign;
4004 	ctx->seal = master_tcon->seal;
4005 	ctx->witness = master_tcon->use_witness;
4006 
4007 	rc = cifs_set_vol_auth(ctx, master_tcon->ses);
4008 	if (rc) {
4009 		tcon = ERR_PTR(rc);
4010 		goto out;
4011 	}
4012 
4013 	/* get a reference for the same TCP session */
4014 	spin_lock(&cifs_tcp_ses_lock);
4015 	++master_tcon->ses->server->srv_count;
4016 	spin_unlock(&cifs_tcp_ses_lock);
4017 
4018 	ses = cifs_get_smb_ses(master_tcon->ses->server, ctx);
4019 	if (IS_ERR(ses)) {
4020 		tcon = (struct cifs_tcon *)ses;
4021 		cifs_put_tcp_session(master_tcon->ses->server, 0);
4022 		goto out;
4023 	}
4024 
4025 	tcon = cifs_get_tcon(ses, ctx);
4026 	if (IS_ERR(tcon)) {
4027 		cifs_put_smb_ses(ses);
4028 		goto out;
4029 	}
4030 
4031 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
4032 	if (cap_unix(ses))
4033 		reset_cifs_unix_caps(0, tcon, NULL, ctx);
4034 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
4035 
4036 out:
4037 	kfree(ctx->username);
4038 	kfree_sensitive(ctx->password);
4039 	kfree(ctx);
4040 
4041 	return tcon;
4042 }
4043 
4044 struct cifs_tcon *
cifs_sb_master_tcon(struct cifs_sb_info * cifs_sb)4045 cifs_sb_master_tcon(struct cifs_sb_info *cifs_sb)
4046 {
4047 	return tlink_tcon(cifs_sb_master_tlink(cifs_sb));
4048 }
4049 
4050 /* find and return a tlink with given uid */
4051 static struct tcon_link *
tlink_rb_search(struct rb_root * root,kuid_t uid)4052 tlink_rb_search(struct rb_root *root, kuid_t uid)
4053 {
4054 	struct rb_node *node = root->rb_node;
4055 	struct tcon_link *tlink;
4056 
4057 	while (node) {
4058 		tlink = rb_entry(node, struct tcon_link, tl_rbnode);
4059 
4060 		if (uid_gt(tlink->tl_uid, uid))
4061 			node = node->rb_left;
4062 		else if (uid_lt(tlink->tl_uid, uid))
4063 			node = node->rb_right;
4064 		else
4065 			return tlink;
4066 	}
4067 	return NULL;
4068 }
4069 
4070 /* insert a tcon_link into the tree */
4071 static void
tlink_rb_insert(struct rb_root * root,struct tcon_link * new_tlink)4072 tlink_rb_insert(struct rb_root *root, struct tcon_link *new_tlink)
4073 {
4074 	struct rb_node **new = &(root->rb_node), *parent = NULL;
4075 	struct tcon_link *tlink;
4076 
4077 	while (*new) {
4078 		tlink = rb_entry(*new, struct tcon_link, tl_rbnode);
4079 		parent = *new;
4080 
4081 		if (uid_gt(tlink->tl_uid, new_tlink->tl_uid))
4082 			new = &((*new)->rb_left);
4083 		else
4084 			new = &((*new)->rb_right);
4085 	}
4086 
4087 	rb_link_node(&new_tlink->tl_rbnode, parent, new);
4088 	rb_insert_color(&new_tlink->tl_rbnode, root);
4089 }
4090 
4091 /*
4092  * Find or construct an appropriate tcon given a cifs_sb and the fsuid of the
4093  * current task.
4094  *
4095  * If the superblock doesn't refer to a multiuser mount, then just return
4096  * the master tcon for the mount.
4097  *
4098  * First, search the rbtree for an existing tcon for this fsuid. If one
4099  * exists, then check to see if it's pending construction. If it is then wait
4100  * for construction to complete. Once it's no longer pending, check to see if
4101  * it failed and either return an error or retry construction, depending on
4102  * the timeout.
4103  *
4104  * If one doesn't exist then insert a new tcon_link struct into the tree and
4105  * try to construct a new one.
4106  */
4107 struct tcon_link *
cifs_sb_tlink(struct cifs_sb_info * cifs_sb)4108 cifs_sb_tlink(struct cifs_sb_info *cifs_sb)
4109 {
4110 	int ret;
4111 	kuid_t fsuid = current_fsuid();
4112 	struct tcon_link *tlink, *newtlink;
4113 
4114 	if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER))
4115 		return cifs_get_tlink(cifs_sb_master_tlink(cifs_sb));
4116 
4117 	spin_lock(&cifs_sb->tlink_tree_lock);
4118 	tlink = tlink_rb_search(&cifs_sb->tlink_tree, fsuid);
4119 	if (tlink)
4120 		cifs_get_tlink(tlink);
4121 	spin_unlock(&cifs_sb->tlink_tree_lock);
4122 
4123 	if (tlink == NULL) {
4124 		newtlink = kzalloc(sizeof(*tlink), GFP_KERNEL);
4125 		if (newtlink == NULL)
4126 			return ERR_PTR(-ENOMEM);
4127 		newtlink->tl_uid = fsuid;
4128 		newtlink->tl_tcon = ERR_PTR(-EACCES);
4129 		set_bit(TCON_LINK_PENDING, &newtlink->tl_flags);
4130 		set_bit(TCON_LINK_IN_TREE, &newtlink->tl_flags);
4131 		cifs_get_tlink(newtlink);
4132 
4133 		spin_lock(&cifs_sb->tlink_tree_lock);
4134 		/* was one inserted after previous search? */
4135 		tlink = tlink_rb_search(&cifs_sb->tlink_tree, fsuid);
4136 		if (tlink) {
4137 			cifs_get_tlink(tlink);
4138 			spin_unlock(&cifs_sb->tlink_tree_lock);
4139 			kfree(newtlink);
4140 			goto wait_for_construction;
4141 		}
4142 		tlink = newtlink;
4143 		tlink_rb_insert(&cifs_sb->tlink_tree, tlink);
4144 		spin_unlock(&cifs_sb->tlink_tree_lock);
4145 	} else {
4146 wait_for_construction:
4147 		ret = wait_on_bit(&tlink->tl_flags, TCON_LINK_PENDING,
4148 				  TASK_INTERRUPTIBLE);
4149 		if (ret) {
4150 			cifs_put_tlink(tlink);
4151 			return ERR_PTR(-ERESTARTSYS);
4152 		}
4153 
4154 		/* if it's good, return it */
4155 		if (!IS_ERR(tlink->tl_tcon))
4156 			return tlink;
4157 
4158 		/* return error if we tried this already recently */
4159 		if (time_before(jiffies, tlink->tl_time + TLINK_ERROR_EXPIRE)) {
4160 			cifs_put_tlink(tlink);
4161 			return ERR_PTR(-EACCES);
4162 		}
4163 
4164 		if (test_and_set_bit(TCON_LINK_PENDING, &tlink->tl_flags))
4165 			goto wait_for_construction;
4166 	}
4167 
4168 	tlink->tl_tcon = cifs_construct_tcon(cifs_sb, fsuid);
4169 	clear_bit(TCON_LINK_PENDING, &tlink->tl_flags);
4170 	wake_up_bit(&tlink->tl_flags, TCON_LINK_PENDING);
4171 
4172 	if (IS_ERR(tlink->tl_tcon)) {
4173 		cifs_put_tlink(tlink);
4174 		return ERR_PTR(-EACCES);
4175 	}
4176 
4177 	return tlink;
4178 }
4179 
4180 /*
4181  * periodic workqueue job that scans tcon_tree for a superblock and closes
4182  * out tcons.
4183  */
4184 static void
cifs_prune_tlinks(struct work_struct * work)4185 cifs_prune_tlinks(struct work_struct *work)
4186 {
4187 	struct cifs_sb_info *cifs_sb = container_of(work, struct cifs_sb_info,
4188 						    prune_tlinks.work);
4189 	struct rb_root *root = &cifs_sb->tlink_tree;
4190 	struct rb_node *node;
4191 	struct rb_node *tmp;
4192 	struct tcon_link *tlink;
4193 
4194 	/*
4195 	 * Because we drop the spinlock in the loop in order to put the tlink
4196 	 * it's not guarded against removal of links from the tree. The only
4197 	 * places that remove entries from the tree are this function and
4198 	 * umounts. Because this function is non-reentrant and is canceled
4199 	 * before umount can proceed, this is safe.
4200 	 */
4201 	spin_lock(&cifs_sb->tlink_tree_lock);
4202 	node = rb_first(root);
4203 	while (node != NULL) {
4204 		tmp = node;
4205 		node = rb_next(tmp);
4206 		tlink = rb_entry(tmp, struct tcon_link, tl_rbnode);
4207 
4208 		if (test_bit(TCON_LINK_MASTER, &tlink->tl_flags) ||
4209 		    atomic_read(&tlink->tl_count) != 0 ||
4210 		    time_after(tlink->tl_time + TLINK_IDLE_EXPIRE, jiffies))
4211 			continue;
4212 
4213 		cifs_get_tlink(tlink);
4214 		clear_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
4215 		rb_erase(tmp, root);
4216 
4217 		spin_unlock(&cifs_sb->tlink_tree_lock);
4218 		cifs_put_tlink(tlink);
4219 		spin_lock(&cifs_sb->tlink_tree_lock);
4220 	}
4221 	spin_unlock(&cifs_sb->tlink_tree_lock);
4222 
4223 	queue_delayed_work(cifsiod_wq, &cifs_sb->prune_tlinks,
4224 				TLINK_IDLE_EXPIRE);
4225 }
4226 
4227 #ifndef CONFIG_CIFS_DFS_UPCALL
cifs_tree_connect(const unsigned int xid,struct cifs_tcon * tcon,const struct nls_table * nlsc)4228 int cifs_tree_connect(const unsigned int xid, struct cifs_tcon *tcon, const struct nls_table *nlsc)
4229 {
4230 	int rc;
4231 	const struct smb_version_operations *ops = tcon->ses->server->ops;
4232 
4233 	/* only send once per connect */
4234 	spin_lock(&tcon->tc_lock);
4235 
4236 	/* if tcon is marked for needing reconnect, update state */
4237 	if (tcon->need_reconnect)
4238 		tcon->status = TID_NEED_TCON;
4239 
4240 	if (tcon->status == TID_GOOD) {
4241 		spin_unlock(&tcon->tc_lock);
4242 		return 0;
4243 	}
4244 
4245 	if (tcon->status != TID_NEW &&
4246 	    tcon->status != TID_NEED_TCON) {
4247 		spin_unlock(&tcon->tc_lock);
4248 		return -EHOSTDOWN;
4249 	}
4250 
4251 	tcon->status = TID_IN_TCON;
4252 	spin_unlock(&tcon->tc_lock);
4253 
4254 	rc = ops->tree_connect(xid, tcon->ses, tcon->tree_name, tcon, nlsc);
4255 	if (rc) {
4256 		spin_lock(&tcon->tc_lock);
4257 		if (tcon->status == TID_IN_TCON)
4258 			tcon->status = TID_NEED_TCON;
4259 		spin_unlock(&tcon->tc_lock);
4260 	} else {
4261 		spin_lock(&tcon->tc_lock);
4262 		if (tcon->status == TID_IN_TCON)
4263 			tcon->status = TID_GOOD;
4264 		tcon->need_reconnect = false;
4265 		spin_unlock(&tcon->tc_lock);
4266 	}
4267 
4268 	return rc;
4269 }
4270 #endif
4271