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v6.2
   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
  55extern mempool_t *cifs_req_poolp;
  56extern 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 NUM_STATUS_IO_TIMEOUT   5
  64
  65static int ip_connect(struct TCP_Server_Info *server);
  66static int generic_ip_connect(struct TCP_Server_Info *server);
  67static void tlink_rb_insert(struct rb_root *root, struct tcon_link *new_tlink);
  68static 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 */
  76static 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	time64_t expiry, now;
  83	unsigned long ttl = SMB_DNS_RESOLVE_INTERVAL_DEFAULT;
  84
  85	if (!server->hostname)
  86		return -EINVAL;
  87
  88	/* if server hostname isn't populated, there's nothing to do here */
  89	if (server->hostname[0] == '\0')
  90		return 0;
  91
  92	len = strlen(server->hostname) + 3;
  93
  94	unc = kmalloc(len, GFP_KERNEL);
  95	if (!unc) {
  96		cifs_dbg(FYI, "%s: failed to create UNC path\n", __func__);
  97		return -ENOMEM;
  98	}
  99	scnprintf(unc, len, "\\\\%s", server->hostname);
 100
 101	spin_lock(&server->srv_lock);
 102	ss = server->dstaddr;
 103	spin_unlock(&server->srv_lock);
 104
 105	rc = dns_resolve_server_name_to_ip(unc, (struct sockaddr *)&ss, &expiry);
 106	kfree(unc);
 107
 108	if (rc < 0) {
 109		cifs_dbg(FYI, "%s: failed to resolve server part of %s to IP: %d\n",
 110			 __func__, server->hostname, rc);
 111		goto requeue_resolve;
 112	}
 113
 114	spin_lock(&server->srv_lock);
 115	memcpy(&server->dstaddr, &ss, sizeof(server->dstaddr));
 116	spin_unlock(&server->srv_lock);
 117
 118	now = ktime_get_real_seconds();
 119	if (expiry && expiry > now)
 120		/* To make sure we don't use the cached entry, retry 1s */
 121		ttl = max_t(unsigned long, expiry - now, SMB_DNS_RESOLVE_INTERVAL_MIN) + 1;
 122
 123requeue_resolve:
 124	cifs_dbg(FYI, "%s: next dns resolution scheduled for %lu seconds in the future\n",
 125		 __func__, ttl);
 126	mod_delayed_work(cifsiod_wq, &server->resolve, (ttl * HZ));
 127
 128	return rc;
 129}
 130
 131static void smb2_query_server_interfaces(struct work_struct *work)
 132{
 133	int rc;
 134	struct cifs_tcon *tcon = container_of(work,
 135					struct cifs_tcon,
 136					query_interfaces.work);
 137
 138	/*
 139	 * query server network interfaces, in case they change
 140	 */
 141	rc = SMB3_request_interfaces(0, tcon, false);
 142	if (rc) {
 143		cifs_dbg(FYI, "%s: failed to query server interfaces: %d\n",
 144				__func__, rc);
 145	}
 146
 147	queue_delayed_work(cifsiod_wq, &tcon->query_interfaces,
 148			   (SMB_INTERFACE_POLL_INTERVAL * HZ));
 149}
 150
 151static void cifs_resolve_server(struct work_struct *work)
 152{
 153	int rc;
 154	struct TCP_Server_Info *server = container_of(work,
 155					struct TCP_Server_Info, resolve.work);
 156
 157	cifs_server_lock(server);
 158
 159	/*
 160	 * Resolve the hostname again to make sure that IP address is up-to-date.
 161	 */
 162	rc = reconn_set_ipaddr_from_hostname(server);
 163	if (rc) {
 164		cifs_dbg(FYI, "%s: failed to resolve hostname: %d\n",
 165				__func__, rc);
 166	}
 167
 168	cifs_server_unlock(server);
 169}
 170
 171/*
 172 * Update the tcpStatus for the server.
 173 * This is used to signal the cifsd thread to call cifs_reconnect
 174 * ONLY cifsd thread should call cifs_reconnect. For any other
 175 * thread, use this function
 176 *
 177 * @server: the tcp ses for which reconnect is needed
 178 * @all_channels: if this needs to be done for all channels
 179 */
 180void
 181cifs_signal_cifsd_for_reconnect(struct TCP_Server_Info *server,
 182				bool all_channels)
 183{
 184	struct TCP_Server_Info *pserver;
 185	struct cifs_ses *ses;
 186	int i;
 187
 188	/* If server is a channel, select the primary channel */
 189	pserver = CIFS_SERVER_IS_CHAN(server) ? server->primary_server : server;
 190
 191	spin_lock(&pserver->srv_lock);
 192	if (!all_channels) {
 193		pserver->tcpStatus = CifsNeedReconnect;
 194		spin_unlock(&pserver->srv_lock);
 195		return;
 196	}
 197	spin_unlock(&pserver->srv_lock);
 198
 199	spin_lock(&cifs_tcp_ses_lock);
 200	list_for_each_entry(ses, &pserver->smb_ses_list, smb_ses_list) {
 201		spin_lock(&ses->chan_lock);
 202		for (i = 0; i < ses->chan_count; i++) {
 203			spin_lock(&ses->chans[i].server->srv_lock);
 204			ses->chans[i].server->tcpStatus = CifsNeedReconnect;
 205			spin_unlock(&ses->chans[i].server->srv_lock);
 206		}
 207		spin_unlock(&ses->chan_lock);
 208	}
 209	spin_unlock(&cifs_tcp_ses_lock);
 210}
 211
 212/*
 213 * Mark all sessions and tcons for reconnect.
 214 * IMPORTANT: make sure that this gets called only from
 215 * cifsd thread. For any other thread, use
 216 * cifs_signal_cifsd_for_reconnect
 217 *
 218 * @server: the tcp ses for which reconnect is needed
 219 * @server needs to be previously set to CifsNeedReconnect.
 220 * @mark_smb_session: whether even sessions need to be marked
 221 */
 222void
 223cifs_mark_tcp_ses_conns_for_reconnect(struct TCP_Server_Info *server,
 224				      bool mark_smb_session)
 225{
 226	struct TCP_Server_Info *pserver;
 227	struct cifs_ses *ses, *nses;
 228	struct cifs_tcon *tcon;
 229
 230	/*
 231	 * before reconnecting the tcp session, mark the smb session (uid) and the tid bad so they
 232	 * are not used until reconnected.
 233	 */
 234	cifs_dbg(FYI, "%s: marking necessary sessions and tcons for reconnect\n", __func__);
 235
 236	/* If server is a channel, select the primary channel */
 237	pserver = CIFS_SERVER_IS_CHAN(server) ? server->primary_server : server;
 238
 239
 240	spin_lock(&cifs_tcp_ses_lock);
 241	list_for_each_entry_safe(ses, nses, &pserver->smb_ses_list, smb_ses_list) {
 242		/* check if iface is still active */
 243		if (!cifs_chan_is_iface_active(ses, server))
 244			cifs_chan_update_iface(ses, server);
 245
 246		spin_lock(&ses->chan_lock);
 247		if (!mark_smb_session && cifs_chan_needs_reconnect(ses, server))
 248			goto next_session;
 249
 250		if (mark_smb_session)
 251			CIFS_SET_ALL_CHANS_NEED_RECONNECT(ses);
 252		else
 253			cifs_chan_set_need_reconnect(ses, server);
 254
 255		/* If all channels need reconnect, then tcon needs reconnect */
 256		if (!mark_smb_session && !CIFS_ALL_CHANS_NEED_RECONNECT(ses))
 257			goto next_session;
 258
 259		ses->ses_status = SES_NEED_RECON;
 260
 261		list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
 262			tcon->need_reconnect = true;
 263			tcon->status = TID_NEED_RECON;
 264		}
 265		if (ses->tcon_ipc) {
 266			ses->tcon_ipc->need_reconnect = true;
 267			ses->tcon_ipc->status = TID_NEED_RECON;
 268		}
 269
 270next_session:
 271		spin_unlock(&ses->chan_lock);
 272	}
 273	spin_unlock(&cifs_tcp_ses_lock);
 274}
 275
 276static void
 277cifs_abort_connection(struct TCP_Server_Info *server)
 278{
 279	struct mid_q_entry *mid, *nmid;
 280	struct list_head retry_list;
 281
 282	server->maxBuf = 0;
 283	server->max_read = 0;
 284
 285	/* do not want to be sending data on a socket we are freeing */
 286	cifs_dbg(FYI, "%s: tearing down socket\n", __func__);
 287	cifs_server_lock(server);
 288	if (server->ssocket) {
 289		cifs_dbg(FYI, "State: 0x%x Flags: 0x%lx\n", server->ssocket->state,
 290			 server->ssocket->flags);
 291		kernel_sock_shutdown(server->ssocket, SHUT_WR);
 292		cifs_dbg(FYI, "Post shutdown state: 0x%x Flags: 0x%lx\n", server->ssocket->state,
 293			 server->ssocket->flags);
 294		sock_release(server->ssocket);
 295		server->ssocket = NULL;
 296	}
 297	server->sequence_number = 0;
 298	server->session_estab = false;
 299	kfree_sensitive(server->session_key.response);
 300	server->session_key.response = NULL;
 301	server->session_key.len = 0;
 302	server->lstrp = jiffies;
 303
 304	/* mark submitted MIDs for retry and issue callback */
 305	INIT_LIST_HEAD(&retry_list);
 306	cifs_dbg(FYI, "%s: moving mids to private list\n", __func__);
 307	spin_lock(&server->mid_lock);
 308	list_for_each_entry_safe(mid, nmid, &server->pending_mid_q, qhead) {
 309		kref_get(&mid->refcount);
 310		if (mid->mid_state == MID_REQUEST_SUBMITTED)
 311			mid->mid_state = MID_RETRY_NEEDED;
 312		list_move(&mid->qhead, &retry_list);
 313		mid->mid_flags |= MID_DELETED;
 314	}
 315	spin_unlock(&server->mid_lock);
 316	cifs_server_unlock(server);
 317
 318	cifs_dbg(FYI, "%s: issuing mid callbacks\n", __func__);
 319	list_for_each_entry_safe(mid, nmid, &retry_list, qhead) {
 320		list_del_init(&mid->qhead);
 321		mid->callback(mid);
 322		release_mid(mid);
 323	}
 324
 325	if (cifs_rdma_enabled(server)) {
 326		cifs_server_lock(server);
 327		smbd_destroy(server);
 328		cifs_server_unlock(server);
 329	}
 330}
 331
 332static bool cifs_tcp_ses_needs_reconnect(struct TCP_Server_Info *server, int num_targets)
 333{
 334	spin_lock(&server->srv_lock);
 335	server->nr_targets = num_targets;
 336	if (server->tcpStatus == CifsExiting) {
 337		/* the demux thread will exit normally next time through the loop */
 338		spin_unlock(&server->srv_lock);
 339		wake_up(&server->response_q);
 340		return false;
 341	}
 342
 343	cifs_dbg(FYI, "Mark tcp session as need reconnect\n");
 344	trace_smb3_reconnect(server->CurrentMid, server->conn_id,
 345			     server->hostname);
 346	server->tcpStatus = CifsNeedReconnect;
 347
 348	spin_unlock(&server->srv_lock);
 349	return true;
 350}
 351
 352/*
 353 * cifs tcp session reconnection
 354 *
 355 * mark tcp session as reconnecting so temporarily locked
 356 * mark all smb sessions as reconnecting for tcp session
 357 * reconnect tcp session
 358 * wake up waiters on reconnection? - (not needed currently)
 359 *
 360 * if mark_smb_session is passed as true, unconditionally mark
 361 * the smb session (and tcon) for reconnect as well. This value
 362 * doesn't really matter for non-multichannel scenario.
 363 *
 364 */
 365static int __cifs_reconnect(struct TCP_Server_Info *server,
 366			    bool mark_smb_session)
 367{
 368	int rc = 0;
 369
 370	if (!cifs_tcp_ses_needs_reconnect(server, 1))
 371		return 0;
 372
 373	cifs_mark_tcp_ses_conns_for_reconnect(server, mark_smb_session);
 374
 375	cifs_abort_connection(server);
 376
 377	do {
 378		try_to_freeze();
 379		cifs_server_lock(server);
 380
 381		if (!cifs_swn_set_server_dstaddr(server)) {
 382			/* resolve the hostname again to make sure that IP address is up-to-date */
 383			rc = reconn_set_ipaddr_from_hostname(server);
 384			cifs_dbg(FYI, "%s: reconn_set_ipaddr_from_hostname: rc=%d\n", __func__, rc);
 385		}
 386
 387		if (cifs_rdma_enabled(server))
 388			rc = smbd_reconnect(server);
 389		else
 390			rc = generic_ip_connect(server);
 391		if (rc) {
 392			cifs_server_unlock(server);
 393			cifs_dbg(FYI, "%s: reconnect error %d\n", __func__, rc);
 394			msleep(3000);
 395		} else {
 396			atomic_inc(&tcpSesReconnectCount);
 397			set_credits(server, 1);
 398			spin_lock(&server->srv_lock);
 399			if (server->tcpStatus != CifsExiting)
 400				server->tcpStatus = CifsNeedNegotiate;
 401			spin_unlock(&server->srv_lock);
 402			cifs_swn_reset_server_dstaddr(server);
 403			cifs_server_unlock(server);
 404			mod_delayed_work(cifsiod_wq, &server->reconnect, 0);
 405		}
 406	} while (server->tcpStatus == CifsNeedReconnect);
 407
 408	spin_lock(&server->srv_lock);
 409	if (server->tcpStatus == CifsNeedNegotiate)
 410		mod_delayed_work(cifsiod_wq, &server->echo, 0);
 411	spin_unlock(&server->srv_lock);
 412
 413	wake_up(&server->response_q);
 414	return rc;
 415}
 416
 417#ifdef CONFIG_CIFS_DFS_UPCALL
 418static int __reconnect_target_unlocked(struct TCP_Server_Info *server, const char *target)
 419{
 420	int rc;
 421	char *hostname;
 422
 423	if (!cifs_swn_set_server_dstaddr(server)) {
 424		if (server->hostname != target) {
 425			hostname = extract_hostname(target);
 426			if (!IS_ERR(hostname)) {
 427				kfree(server->hostname);
 428				server->hostname = hostname;
 429			} else {
 430				cifs_dbg(FYI, "%s: couldn't extract hostname or address from dfs target: %ld\n",
 431					 __func__, PTR_ERR(hostname));
 432				cifs_dbg(FYI, "%s: default to last target server: %s\n", __func__,
 433					 server->hostname);
 434			}
 435		}
 436		/* resolve the hostname again to make sure that IP address is up-to-date. */
 437		rc = reconn_set_ipaddr_from_hostname(server);
 438		cifs_dbg(FYI, "%s: reconn_set_ipaddr_from_hostname: rc=%d\n", __func__, rc);
 439	}
 440	/* Reconnect the socket */
 441	if (cifs_rdma_enabled(server))
 442		rc = smbd_reconnect(server);
 443	else
 444		rc = generic_ip_connect(server);
 445
 446	return rc;
 447}
 448
 449static int reconnect_target_unlocked(struct TCP_Server_Info *server, struct dfs_cache_tgt_list *tl,
 450				     struct dfs_cache_tgt_iterator **target_hint)
 451{
 452	int rc;
 453	struct dfs_cache_tgt_iterator *tit;
 454
 455	*target_hint = NULL;
 456
 457	/* If dfs target list is empty, then reconnect to last server */
 458	tit = dfs_cache_get_tgt_iterator(tl);
 459	if (!tit)
 460		return __reconnect_target_unlocked(server, server->hostname);
 461
 462	/* Otherwise, try every dfs target in @tl */
 463	for (; tit; tit = dfs_cache_get_next_tgt(tl, tit)) {
 464		rc = __reconnect_target_unlocked(server, dfs_cache_get_tgt_name(tit));
 465		if (!rc) {
 466			*target_hint = tit;
 467			break;
 468		}
 469	}
 470	return rc;
 471}
 472
 473static int reconnect_dfs_server(struct TCP_Server_Info *server)
 474{
 475	int rc = 0;
 476	const char *refpath = server->current_fullpath + 1;
 477	struct dfs_cache_tgt_list tl = DFS_CACHE_TGT_LIST_INIT(tl);
 478	struct dfs_cache_tgt_iterator *target_hint = NULL;
 479	int num_targets = 0;
 480
 481	/*
 482	 * Determine the number of dfs targets the referral path in @cifs_sb resolves to.
 483	 *
 484	 * smb2_reconnect() needs to know how long it should wait based upon the number of dfs
 485	 * targets (server->nr_targets).  It's also possible that the cached referral was cleared
 486	 * through /proc/fs/cifs/dfscache or the target list is empty due to server settings after
 487	 * refreshing the referral, so, in this case, default it to 1.
 488	 */
 489	if (!dfs_cache_noreq_find(refpath, NULL, &tl))
 490		num_targets = dfs_cache_get_nr_tgts(&tl);
 491	if (!num_targets)
 492		num_targets = 1;
 493
 494	if (!cifs_tcp_ses_needs_reconnect(server, num_targets))
 495		return 0;
 496
 497	/*
 498	 * Unconditionally mark all sessions & tcons for reconnect as we might be connecting to a
 499	 * different server or share during failover.  It could be improved by adding some logic to
 500	 * only do that in case it connects to a different server or share, though.
 501	 */
 502	cifs_mark_tcp_ses_conns_for_reconnect(server, true);
 503
 504	cifs_abort_connection(server);
 505
 506	do {
 507		try_to_freeze();
 508		cifs_server_lock(server);
 509
 510		rc = reconnect_target_unlocked(server, &tl, &target_hint);
 511		if (rc) {
 512			/* Failed to reconnect socket */
 513			cifs_server_unlock(server);
 514			cifs_dbg(FYI, "%s: reconnect error %d\n", __func__, rc);
 515			msleep(3000);
 516			continue;
 517		}
 518		/*
 519		 * Socket was created.  Update tcp session status to CifsNeedNegotiate so that a
 520		 * process waiting for reconnect will know it needs to re-establish session and tcon
 521		 * through the reconnected target server.
 522		 */
 523		atomic_inc(&tcpSesReconnectCount);
 524		set_credits(server, 1);
 525		spin_lock(&server->srv_lock);
 526		if (server->tcpStatus != CifsExiting)
 527			server->tcpStatus = CifsNeedNegotiate;
 528		spin_unlock(&server->srv_lock);
 529		cifs_swn_reset_server_dstaddr(server);
 530		cifs_server_unlock(server);
 531		mod_delayed_work(cifsiod_wq, &server->reconnect, 0);
 532	} while (server->tcpStatus == CifsNeedReconnect);
 533
 534	dfs_cache_noreq_update_tgthint(refpath, target_hint);
 535	dfs_cache_free_tgts(&tl);
 536
 537	/* Need to set up echo worker again once connection has been established */
 538	spin_lock(&server->srv_lock);
 539	if (server->tcpStatus == CifsNeedNegotiate)
 540		mod_delayed_work(cifsiod_wq, &server->echo, 0);
 541	spin_unlock(&server->srv_lock);
 542
 543	wake_up(&server->response_q);
 544	return rc;
 545}
 546
 547int cifs_reconnect(struct TCP_Server_Info *server, bool mark_smb_session)
 548{
 549	mutex_lock(&server->refpath_lock);
 550	if (!server->leaf_fullpath) {
 551		mutex_unlock(&server->refpath_lock);
 552		return __cifs_reconnect(server, mark_smb_session);
 553	}
 554	mutex_unlock(&server->refpath_lock);
 555
 556	return reconnect_dfs_server(server);
 557}
 558#else
 559int cifs_reconnect(struct TCP_Server_Info *server, bool mark_smb_session)
 560{
 561	return __cifs_reconnect(server, mark_smb_session);
 562}
 563#endif
 564
 565static void
 566cifs_echo_request(struct work_struct *work)
 567{
 568	int rc;
 569	struct TCP_Server_Info *server = container_of(work,
 570					struct TCP_Server_Info, echo.work);
 571
 572	/*
 573	 * We cannot send an echo if it is disabled.
 574	 * Also, no need to ping if we got a response recently.
 575	 */
 576
 577	if (server->tcpStatus == CifsNeedReconnect ||
 578	    server->tcpStatus == CifsExiting ||
 579	    server->tcpStatus == CifsNew ||
 580	    (server->ops->can_echo && !server->ops->can_echo(server)) ||
 581	    time_before(jiffies, server->lstrp + server->echo_interval - HZ))
 582		goto requeue_echo;
 583
 584	rc = server->ops->echo ? server->ops->echo(server) : -ENOSYS;
 585	if (rc)
 586		cifs_dbg(FYI, "Unable to send echo request to server: %s\n",
 587			 server->hostname);
 588
 589	/* Check witness registrations */
 590	cifs_swn_check();
 591
 592requeue_echo:
 593	queue_delayed_work(cifsiod_wq, &server->echo, server->echo_interval);
 594}
 595
 596static bool
 597allocate_buffers(struct TCP_Server_Info *server)
 598{
 599	if (!server->bigbuf) {
 600		server->bigbuf = (char *)cifs_buf_get();
 601		if (!server->bigbuf) {
 602			cifs_server_dbg(VFS, "No memory for large SMB response\n");
 603			msleep(3000);
 604			/* retry will check if exiting */
 605			return false;
 606		}
 607	} else if (server->large_buf) {
 608		/* we are reusing a dirty large buf, clear its start */
 609		memset(server->bigbuf, 0, HEADER_SIZE(server));
 610	}
 611
 612	if (!server->smallbuf) {
 613		server->smallbuf = (char *)cifs_small_buf_get();
 614		if (!server->smallbuf) {
 615			cifs_server_dbg(VFS, "No memory for SMB response\n");
 616			msleep(1000);
 617			/* retry will check if exiting */
 618			return false;
 619		}
 620		/* beginning of smb buffer is cleared in our buf_get */
 621	} else {
 622		/* if existing small buf clear beginning */
 623		memset(server->smallbuf, 0, HEADER_SIZE(server));
 624	}
 625
 626	return true;
 627}
 628
 629static bool
 630server_unresponsive(struct TCP_Server_Info *server)
 631{
 632	/*
 633	 * We need to wait 3 echo intervals to make sure we handle such
 634	 * situations right:
 635	 * 1s  client sends a normal SMB request
 636	 * 2s  client gets a response
 637	 * 30s echo workqueue job pops, and decides we got a response recently
 638	 *     and don't need to send another
 639	 * ...
 640	 * 65s kernel_recvmsg times out, and we see that we haven't gotten
 641	 *     a response in >60s.
 642	 */
 643	spin_lock(&server->srv_lock);
 644	if ((server->tcpStatus == CifsGood ||
 645	    server->tcpStatus == CifsNeedNegotiate) &&
 646	    (!server->ops->can_echo || server->ops->can_echo(server)) &&
 647	    time_after(jiffies, server->lstrp + 3 * server->echo_interval)) {
 648		spin_unlock(&server->srv_lock);
 649		cifs_server_dbg(VFS, "has not responded in %lu seconds. Reconnecting...\n",
 650			 (3 * server->echo_interval) / HZ);
 651		cifs_reconnect(server, false);
 652		return true;
 653	}
 654	spin_unlock(&server->srv_lock);
 655
 656	return false;
 657}
 658
 659static inline bool
 660zero_credits(struct TCP_Server_Info *server)
 661{
 662	int val;
 663
 664	spin_lock(&server->req_lock);
 665	val = server->credits + server->echo_credits + server->oplock_credits;
 666	if (server->in_flight == 0 && val == 0) {
 667		spin_unlock(&server->req_lock);
 668		return true;
 669	}
 670	spin_unlock(&server->req_lock);
 671	return false;
 672}
 673
 674static int
 675cifs_readv_from_socket(struct TCP_Server_Info *server, struct msghdr *smb_msg)
 676{
 677	int length = 0;
 678	int total_read;
 679
 680	for (total_read = 0; msg_data_left(smb_msg); total_read += length) {
 681		try_to_freeze();
 682
 683		/* reconnect if no credits and no requests in flight */
 684		if (zero_credits(server)) {
 685			cifs_reconnect(server, false);
 686			return -ECONNABORTED;
 687		}
 688
 689		if (server_unresponsive(server))
 690			return -ECONNABORTED;
 691		if (cifs_rdma_enabled(server) && server->smbd_conn)
 692			length = smbd_recv(server->smbd_conn, smb_msg);
 693		else
 694			length = sock_recvmsg(server->ssocket, smb_msg, 0);
 695
 696		spin_lock(&server->srv_lock);
 697		if (server->tcpStatus == CifsExiting) {
 698			spin_unlock(&server->srv_lock);
 699			return -ESHUTDOWN;
 700		}
 701
 702		if (server->tcpStatus == CifsNeedReconnect) {
 703			spin_unlock(&server->srv_lock);
 704			cifs_reconnect(server, false);
 705			return -ECONNABORTED;
 706		}
 707		spin_unlock(&server->srv_lock);
 708
 709		if (length == -ERESTARTSYS ||
 710		    length == -EAGAIN ||
 711		    length == -EINTR) {
 712			/*
 713			 * Minimum sleep to prevent looping, allowing socket
 714			 * to clear and app threads to set tcpStatus
 715			 * CifsNeedReconnect if server hung.
 716			 */
 717			usleep_range(1000, 2000);
 718			length = 0;
 719			continue;
 720		}
 721
 722		if (length <= 0) {
 723			cifs_dbg(FYI, "Received no data or error: %d\n", length);
 724			cifs_reconnect(server, false);
 725			return -ECONNABORTED;
 726		}
 727	}
 728	return total_read;
 729}
 730
 731int
 732cifs_read_from_socket(struct TCP_Server_Info *server, char *buf,
 733		      unsigned int to_read)
 734{
 735	struct msghdr smb_msg = {};
 736	struct kvec iov = {.iov_base = buf, .iov_len = to_read};
 737	iov_iter_kvec(&smb_msg.msg_iter, ITER_DEST, &iov, 1, to_read);
 738
 739	return cifs_readv_from_socket(server, &smb_msg);
 740}
 741
 742ssize_t
 743cifs_discard_from_socket(struct TCP_Server_Info *server, size_t to_read)
 744{
 745	struct msghdr smb_msg = {};
 746
 747	/*
 748	 *  iov_iter_discard already sets smb_msg.type and count and iov_offset
 749	 *  and cifs_readv_from_socket sets msg_control and msg_controllen
 750	 *  so little to initialize in struct msghdr
 751	 */
 752	iov_iter_discard(&smb_msg.msg_iter, ITER_DEST, to_read);
 753
 754	return cifs_readv_from_socket(server, &smb_msg);
 755}
 756
 757int
 758cifs_read_page_from_socket(struct TCP_Server_Info *server, struct page *page,
 759	unsigned int page_offset, unsigned int to_read)
 760{
 761	struct msghdr smb_msg = {};
 762	struct bio_vec bv = {
 763		.bv_page = page, .bv_len = to_read, .bv_offset = page_offset};
 764	iov_iter_bvec(&smb_msg.msg_iter, ITER_DEST, &bv, 1, to_read);
 765	return cifs_readv_from_socket(server, &smb_msg);
 766}
 767
 768static bool
 769is_smb_response(struct TCP_Server_Info *server, unsigned char type)
 770{
 771	/*
 772	 * The first byte big endian of the length field,
 773	 * is actually not part of the length but the type
 774	 * with the most common, zero, as regular data.
 775	 */
 776	switch (type) {
 777	case RFC1002_SESSION_MESSAGE:
 778		/* Regular SMB response */
 779		return true;
 780	case RFC1002_SESSION_KEEP_ALIVE:
 781		cifs_dbg(FYI, "RFC 1002 session keep alive\n");
 782		break;
 783	case RFC1002_POSITIVE_SESSION_RESPONSE:
 784		cifs_dbg(FYI, "RFC 1002 positive session response\n");
 785		break;
 786	case RFC1002_NEGATIVE_SESSION_RESPONSE:
 787		/*
 788		 * We get this from Windows 98 instead of an error on
 789		 * SMB negprot response.
 790		 */
 791		cifs_dbg(FYI, "RFC 1002 negative session response\n");
 792		/* give server a second to clean up */
 793		msleep(1000);
 794		/*
 795		 * Always try 445 first on reconnect since we get NACK
 796		 * on some if we ever connected to port 139 (the NACK
 797		 * is since we do not begin with RFC1001 session
 798		 * initialize frame).
 799		 */
 800		cifs_set_port((struct sockaddr *)&server->dstaddr, CIFS_PORT);
 801		cifs_reconnect(server, true);
 802		break;
 803	default:
 804		cifs_server_dbg(VFS, "RFC 1002 unknown response type 0x%x\n", type);
 805		cifs_reconnect(server, true);
 806	}
 807
 808	return false;
 809}
 810
 811void
 812dequeue_mid(struct mid_q_entry *mid, bool malformed)
 813{
 814#ifdef CONFIG_CIFS_STATS2
 815	mid->when_received = jiffies;
 816#endif
 817	spin_lock(&mid->server->mid_lock);
 818	if (!malformed)
 819		mid->mid_state = MID_RESPONSE_RECEIVED;
 820	else
 821		mid->mid_state = MID_RESPONSE_MALFORMED;
 822	/*
 823	 * Trying to handle/dequeue a mid after the send_recv()
 824	 * function has finished processing it is a bug.
 825	 */
 826	if (mid->mid_flags & MID_DELETED) {
 827		spin_unlock(&mid->server->mid_lock);
 828		pr_warn_once("trying to dequeue a deleted mid\n");
 829	} else {
 830		list_del_init(&mid->qhead);
 831		mid->mid_flags |= MID_DELETED;
 832		spin_unlock(&mid->server->mid_lock);
 833	}
 834}
 835
 836static unsigned int
 837smb2_get_credits_from_hdr(char *buffer, struct TCP_Server_Info *server)
 838{
 839	struct smb2_hdr *shdr = (struct smb2_hdr *)buffer;
 840
 841	/*
 842	 * SMB1 does not use credits.
 843	 */
 844	if (is_smb1(server))
 845		return 0;
 846
 847	return le16_to_cpu(shdr->CreditRequest);
 848}
 849
 850static void
 851handle_mid(struct mid_q_entry *mid, struct TCP_Server_Info *server,
 852	   char *buf, int malformed)
 853{
 854	if (server->ops->check_trans2 &&
 855	    server->ops->check_trans2(mid, server, buf, malformed))
 856		return;
 857	mid->credits_received = smb2_get_credits_from_hdr(buf, server);
 858	mid->resp_buf = buf;
 859	mid->large_buf = server->large_buf;
 860	/* Was previous buf put in mpx struct for multi-rsp? */
 861	if (!mid->multiRsp) {
 862		/* smb buffer will be freed by user thread */
 863		if (server->large_buf)
 864			server->bigbuf = NULL;
 865		else
 866			server->smallbuf = NULL;
 867	}
 868	dequeue_mid(mid, malformed);
 869}
 870
 871int
 872cifs_enable_signing(struct TCP_Server_Info *server, bool mnt_sign_required)
 873{
 874	bool srv_sign_required = server->sec_mode & server->vals->signing_required;
 875	bool srv_sign_enabled = server->sec_mode & server->vals->signing_enabled;
 876	bool mnt_sign_enabled;
 877
 878	/*
 879	 * Is signing required by mnt options? If not then check
 880	 * global_secflags to see if it is there.
 881	 */
 882	if (!mnt_sign_required)
 883		mnt_sign_required = ((global_secflags & CIFSSEC_MUST_SIGN) ==
 884						CIFSSEC_MUST_SIGN);
 885
 886	/*
 887	 * If signing is required then it's automatically enabled too,
 888	 * otherwise, check to see if the secflags allow it.
 889	 */
 890	mnt_sign_enabled = mnt_sign_required ? mnt_sign_required :
 891				(global_secflags & CIFSSEC_MAY_SIGN);
 892
 893	/* If server requires signing, does client allow it? */
 894	if (srv_sign_required) {
 895		if (!mnt_sign_enabled) {
 896			cifs_dbg(VFS, "Server requires signing, but it's disabled in SecurityFlags!\n");
 897			return -EOPNOTSUPP;
 898		}
 899		server->sign = true;
 900	}
 901
 902	/* If client requires signing, does server allow it? */
 903	if (mnt_sign_required) {
 904		if (!srv_sign_enabled) {
 905			cifs_dbg(VFS, "Server does not support signing!\n");
 906			return -EOPNOTSUPP;
 907		}
 908		server->sign = true;
 909	}
 910
 911	if (cifs_rdma_enabled(server) && server->sign)
 912		cifs_dbg(VFS, "Signing is enabled, and RDMA read/write will be disabled\n");
 913
 914	return 0;
 915}
 916
 917
 918static void clean_demultiplex_info(struct TCP_Server_Info *server)
 919{
 920	int length;
 921
 922	/* take it off the list, if it's not already */
 923	spin_lock(&server->srv_lock);
 924	list_del_init(&server->tcp_ses_list);
 925	spin_unlock(&server->srv_lock);
 926
 927	cancel_delayed_work_sync(&server->echo);
 928	cancel_delayed_work_sync(&server->resolve);
 929
 930	spin_lock(&server->srv_lock);
 931	server->tcpStatus = CifsExiting;
 932	spin_unlock(&server->srv_lock);
 933	wake_up_all(&server->response_q);
 934
 935	/* check if we have blocked requests that need to free */
 936	spin_lock(&server->req_lock);
 937	if (server->credits <= 0)
 938		server->credits = 1;
 939	spin_unlock(&server->req_lock);
 940	/*
 941	 * Although there should not be any requests blocked on this queue it
 942	 * can not hurt to be paranoid and try to wake up requests that may
 943	 * haven been blocked when more than 50 at time were on the wire to the
 944	 * same server - they now will see the session is in exit state and get
 945	 * out of SendReceive.
 946	 */
 947	wake_up_all(&server->request_q);
 948	/* give those requests time to exit */
 949	msleep(125);
 950	if (cifs_rdma_enabled(server))
 951		smbd_destroy(server);
 952	if (server->ssocket) {
 953		sock_release(server->ssocket);
 954		server->ssocket = NULL;
 955	}
 956
 957	if (!list_empty(&server->pending_mid_q)) {
 958		struct list_head dispose_list;
 959		struct mid_q_entry *mid_entry;
 960		struct list_head *tmp, *tmp2;
 961
 962		INIT_LIST_HEAD(&dispose_list);
 963		spin_lock(&server->mid_lock);
 964		list_for_each_safe(tmp, tmp2, &server->pending_mid_q) {
 965			mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
 966			cifs_dbg(FYI, "Clearing mid %llu\n", mid_entry->mid);
 967			kref_get(&mid_entry->refcount);
 968			mid_entry->mid_state = MID_SHUTDOWN;
 969			list_move(&mid_entry->qhead, &dispose_list);
 970			mid_entry->mid_flags |= MID_DELETED;
 971		}
 972		spin_unlock(&server->mid_lock);
 973
 974		/* now walk dispose list and issue callbacks */
 975		list_for_each_safe(tmp, tmp2, &dispose_list) {
 976			mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
 977			cifs_dbg(FYI, "Callback mid %llu\n", mid_entry->mid);
 978			list_del_init(&mid_entry->qhead);
 979			mid_entry->callback(mid_entry);
 980			release_mid(mid_entry);
 981		}
 982		/* 1/8th of sec is more than enough time for them to exit */
 983		msleep(125);
 984	}
 985
 986	if (!list_empty(&server->pending_mid_q)) {
 987		/*
 988		 * mpx threads have not exited yet give them at least the smb
 989		 * send timeout time for long ops.
 990		 *
 991		 * Due to delays on oplock break requests, we need to wait at
 992		 * least 45 seconds before giving up on a request getting a
 993		 * response and going ahead and killing cifsd.
 994		 */
 995		cifs_dbg(FYI, "Wait for exit from demultiplex thread\n");
 996		msleep(46000);
 997		/*
 998		 * If threads still have not exited they are probably never
 999		 * coming home not much else we can do but free the memory.
1000		 */
1001	}
1002
1003#ifdef CONFIG_CIFS_DFS_UPCALL
1004	kfree(server->origin_fullpath);
1005	kfree(server->leaf_fullpath);
1006#endif
1007	kfree(server);
1008
1009	length = atomic_dec_return(&tcpSesAllocCount);
1010	if (length > 0)
1011		mempool_resize(cifs_req_poolp, length + cifs_min_rcv);
1012}
1013
1014static int
1015standard_receive3(struct TCP_Server_Info *server, struct mid_q_entry *mid)
1016{
1017	int length;
1018	char *buf = server->smallbuf;
1019	unsigned int pdu_length = server->pdu_size;
1020
1021	/* make sure this will fit in a large buffer */
1022	if (pdu_length > CIFSMaxBufSize + MAX_HEADER_SIZE(server) -
1023	    HEADER_PREAMBLE_SIZE(server)) {
1024		cifs_server_dbg(VFS, "SMB response too long (%u bytes)\n", pdu_length);
1025		cifs_reconnect(server, true);
1026		return -ECONNABORTED;
1027	}
1028
1029	/* switch to large buffer if too big for a small one */
1030	if (pdu_length > MAX_CIFS_SMALL_BUFFER_SIZE - 4) {
1031		server->large_buf = true;
1032		memcpy(server->bigbuf, buf, server->total_read);
1033		buf = server->bigbuf;
1034	}
1035
1036	/* now read the rest */
1037	length = cifs_read_from_socket(server, buf + HEADER_SIZE(server) - 1,
1038				       pdu_length - MID_HEADER_SIZE(server));
1039
1040	if (length < 0)
1041		return length;
1042	server->total_read += length;
1043
1044	dump_smb(buf, server->total_read);
1045
1046	return cifs_handle_standard(server, mid);
1047}
1048
1049int
1050cifs_handle_standard(struct TCP_Server_Info *server, struct mid_q_entry *mid)
1051{
1052	char *buf = server->large_buf ? server->bigbuf : server->smallbuf;
1053	int rc;
1054
1055	/*
1056	 * We know that we received enough to get to the MID as we
1057	 * checked the pdu_length earlier. Now check to see
1058	 * if the rest of the header is OK.
1059	 *
1060	 * 48 bytes is enough to display the header and a little bit
1061	 * into the payload for debugging purposes.
1062	 */
1063	rc = server->ops->check_message(buf, server->total_read, server);
1064	if (rc)
1065		cifs_dump_mem("Bad SMB: ", buf,
1066			min_t(unsigned int, server->total_read, 48));
1067
1068	if (server->ops->is_session_expired &&
1069	    server->ops->is_session_expired(buf)) {
1070		cifs_reconnect(server, true);
1071		return -1;
1072	}
1073
1074	if (server->ops->is_status_pending &&
1075	    server->ops->is_status_pending(buf, server))
1076		return -1;
1077
1078	if (!mid)
1079		return rc;
1080
1081	handle_mid(mid, server, buf, rc);
1082	return 0;
1083}
1084
1085static void
1086smb2_add_credits_from_hdr(char *buffer, struct TCP_Server_Info *server)
1087{
1088	struct smb2_hdr *shdr = (struct smb2_hdr *)buffer;
1089	int scredits, in_flight;
1090
1091	/*
1092	 * SMB1 does not use credits.
1093	 */
1094	if (is_smb1(server))
1095		return;
1096
1097	if (shdr->CreditRequest) {
1098		spin_lock(&server->req_lock);
1099		server->credits += le16_to_cpu(shdr->CreditRequest);
1100		scredits = server->credits;
1101		in_flight = server->in_flight;
1102		spin_unlock(&server->req_lock);
1103		wake_up(&server->request_q);
1104
1105		trace_smb3_hdr_credits(server->CurrentMid,
1106				server->conn_id, server->hostname, scredits,
1107				le16_to_cpu(shdr->CreditRequest), in_flight);
1108		cifs_server_dbg(FYI, "%s: added %u credits total=%d\n",
1109				__func__, le16_to_cpu(shdr->CreditRequest),
1110				scredits);
1111	}
1112}
1113
1114
1115static int
1116cifs_demultiplex_thread(void *p)
1117{
1118	int i, num_mids, length;
1119	struct TCP_Server_Info *server = p;
1120	unsigned int pdu_length;
1121	unsigned int next_offset;
1122	char *buf = NULL;
1123	struct task_struct *task_to_wake = NULL;
1124	struct mid_q_entry *mids[MAX_COMPOUND];
1125	char *bufs[MAX_COMPOUND];
1126	unsigned int noreclaim_flag, num_io_timeout = 0;
1127
1128	noreclaim_flag = memalloc_noreclaim_save();
1129	cifs_dbg(FYI, "Demultiplex PID: %d\n", task_pid_nr(current));
1130
1131	length = atomic_inc_return(&tcpSesAllocCount);
1132	if (length > 1)
1133		mempool_resize(cifs_req_poolp, length + cifs_min_rcv);
1134
1135	set_freezable();
1136	allow_kernel_signal(SIGKILL);
1137	while (server->tcpStatus != CifsExiting) {
1138		if (try_to_freeze())
1139			continue;
1140
1141		if (!allocate_buffers(server))
1142			continue;
1143
1144		server->large_buf = false;
1145		buf = server->smallbuf;
1146		pdu_length = 4; /* enough to get RFC1001 header */
1147
1148		length = cifs_read_from_socket(server, buf, pdu_length);
1149		if (length < 0)
1150			continue;
1151
1152		if (is_smb1(server))
1153			server->total_read = length;
1154		else
1155			server->total_read = 0;
1156
1157		/*
1158		 * The right amount was read from socket - 4 bytes,
1159		 * so we can now interpret the length field.
1160		 */
1161		pdu_length = get_rfc1002_length(buf);
1162
1163		cifs_dbg(FYI, "RFC1002 header 0x%x\n", pdu_length);
1164		if (!is_smb_response(server, buf[0]))
1165			continue;
1166next_pdu:
1167		server->pdu_size = pdu_length;
1168
1169		/* make sure we have enough to get to the MID */
1170		if (server->pdu_size < MID_HEADER_SIZE(server)) {
1171			cifs_server_dbg(VFS, "SMB response too short (%u bytes)\n",
1172				 server->pdu_size);
1173			cifs_reconnect(server, true);
1174			continue;
1175		}
1176
1177		/* read down to the MID */
1178		length = cifs_read_from_socket(server,
1179			     buf + HEADER_PREAMBLE_SIZE(server),
1180			     MID_HEADER_SIZE(server));
1181		if (length < 0)
1182			continue;
1183		server->total_read += length;
1184
1185		if (server->ops->next_header) {
1186			next_offset = server->ops->next_header(buf);
1187			if (next_offset)
1188				server->pdu_size = next_offset;
1189		}
1190
1191		memset(mids, 0, sizeof(mids));
1192		memset(bufs, 0, sizeof(bufs));
1193		num_mids = 0;
1194
1195		if (server->ops->is_transform_hdr &&
1196		    server->ops->receive_transform &&
1197		    server->ops->is_transform_hdr(buf)) {
1198			length = server->ops->receive_transform(server,
1199								mids,
1200								bufs,
1201								&num_mids);
1202		} else {
1203			mids[0] = server->ops->find_mid(server, buf);
1204			bufs[0] = buf;
1205			num_mids = 1;
1206
1207			if (!mids[0] || !mids[0]->receive)
1208				length = standard_receive3(server, mids[0]);
1209			else
1210				length = mids[0]->receive(server, mids[0]);
1211		}
1212
1213		if (length < 0) {
1214			for (i = 0; i < num_mids; i++)
1215				if (mids[i])
1216					release_mid(mids[i]);
1217			continue;
1218		}
1219
1220		if (server->ops->is_status_io_timeout &&
1221		    server->ops->is_status_io_timeout(buf)) {
1222			num_io_timeout++;
1223			if (num_io_timeout > NUM_STATUS_IO_TIMEOUT) {
1224				cifs_reconnect(server, false);
1225				num_io_timeout = 0;
1226				continue;
1227			}
1228		}
1229
1230		server->lstrp = jiffies;
1231
1232		for (i = 0; i < num_mids; i++) {
1233			if (mids[i] != NULL) {
1234				mids[i]->resp_buf_size = server->pdu_size;
1235
1236				if (bufs[i] && server->ops->is_network_name_deleted)
1237					server->ops->is_network_name_deleted(bufs[i],
1238									server);
1239
1240				if (!mids[i]->multiRsp || mids[i]->multiEnd)
1241					mids[i]->callback(mids[i]);
1242
1243				release_mid(mids[i]);
1244			} else if (server->ops->is_oplock_break &&
1245				   server->ops->is_oplock_break(bufs[i],
1246								server)) {
1247				smb2_add_credits_from_hdr(bufs[i], server);
1248				cifs_dbg(FYI, "Received oplock break\n");
1249			} else {
1250				cifs_server_dbg(VFS, "No task to wake, unknown frame received! NumMids %d\n",
1251						atomic_read(&mid_count));
1252				cifs_dump_mem("Received Data is: ", bufs[i],
1253					      HEADER_SIZE(server));
1254				smb2_add_credits_from_hdr(bufs[i], server);
1255#ifdef CONFIG_CIFS_DEBUG2
1256				if (server->ops->dump_detail)
1257					server->ops->dump_detail(bufs[i],
1258								 server);
1259				cifs_dump_mids(server);
1260#endif /* CIFS_DEBUG2 */
1261			}
1262		}
1263
1264		if (pdu_length > server->pdu_size) {
1265			if (!allocate_buffers(server))
1266				continue;
1267			pdu_length -= server->pdu_size;
1268			server->total_read = 0;
1269			server->large_buf = false;
1270			buf = server->smallbuf;
1271			goto next_pdu;
1272		}
1273	} /* end while !EXITING */
1274
1275	/* buffer usually freed in free_mid - need to free it here on exit */
1276	cifs_buf_release(server->bigbuf);
1277	if (server->smallbuf) /* no sense logging a debug message if NULL */
1278		cifs_small_buf_release(server->smallbuf);
1279
1280	task_to_wake = xchg(&server->tsk, NULL);
1281	clean_demultiplex_info(server);
1282
1283	/* if server->tsk was NULL then wait for a signal before exiting */
1284	if (!task_to_wake) {
1285		set_current_state(TASK_INTERRUPTIBLE);
1286		while (!signal_pending(current)) {
1287			schedule();
1288			set_current_state(TASK_INTERRUPTIBLE);
1289		}
1290		set_current_state(TASK_RUNNING);
1291	}
1292
1293	memalloc_noreclaim_restore(noreclaim_flag);
1294	module_put_and_kthread_exit(0);
1295}
1296
1297/*
1298 * Returns true if srcaddr isn't specified and rhs isn't specified, or
1299 * if srcaddr is specified and matches the IP address of the rhs argument
1300 */
1301bool
1302cifs_match_ipaddr(struct sockaddr *srcaddr, struct sockaddr *rhs)
1303{
1304	switch (srcaddr->sa_family) {
1305	case AF_UNSPEC:
1306		return (rhs->sa_family == AF_UNSPEC);
1307	case AF_INET: {
1308		struct sockaddr_in *saddr4 = (struct sockaddr_in *)srcaddr;
1309		struct sockaddr_in *vaddr4 = (struct sockaddr_in *)rhs;
1310		return (saddr4->sin_addr.s_addr == vaddr4->sin_addr.s_addr);
1311	}
1312	case AF_INET6: {
1313		struct sockaddr_in6 *saddr6 = (struct sockaddr_in6 *)srcaddr;
1314		struct sockaddr_in6 *vaddr6 = (struct sockaddr_in6 *)rhs;
1315		return ipv6_addr_equal(&saddr6->sin6_addr, &vaddr6->sin6_addr);
1316	}
1317	default:
1318		WARN_ON(1);
1319		return false; /* don't expect to be here */
1320	}
1321}
1322
1323/*
1324 * If no port is specified in addr structure, we try to match with 445 port
1325 * and if it fails - with 139 ports. It should be called only if address
1326 * families of server and addr are equal.
1327 */
1328static bool
1329match_port(struct TCP_Server_Info *server, struct sockaddr *addr)
1330{
1331	__be16 port, *sport;
1332
1333	/* SMBDirect manages its own ports, don't match it here */
1334	if (server->rdma)
1335		return true;
1336
1337	switch (addr->sa_family) {
1338	case AF_INET:
1339		sport = &((struct sockaddr_in *) &server->dstaddr)->sin_port;
1340		port = ((struct sockaddr_in *) addr)->sin_port;
1341		break;
1342	case AF_INET6:
1343		sport = &((struct sockaddr_in6 *) &server->dstaddr)->sin6_port;
1344		port = ((struct sockaddr_in6 *) addr)->sin6_port;
1345		break;
1346	default:
1347		WARN_ON(1);
1348		return false;
1349	}
1350
1351	if (!port) {
1352		port = htons(CIFS_PORT);
1353		if (port == *sport)
1354			return true;
1355
1356		port = htons(RFC1001_PORT);
1357	}
1358
1359	return port == *sport;
1360}
1361
1362static bool match_server_address(struct TCP_Server_Info *server, struct sockaddr *addr)
1363{
1364	switch (addr->sa_family) {
1365	case AF_INET: {
1366		struct sockaddr_in *addr4 = (struct sockaddr_in *)addr;
1367		struct sockaddr_in *srv_addr4 =
1368					(struct sockaddr_in *)&server->dstaddr;
1369
1370		if (addr4->sin_addr.s_addr != srv_addr4->sin_addr.s_addr)
1371			return false;
1372		break;
1373	}
1374	case AF_INET6: {
1375		struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)addr;
1376		struct sockaddr_in6 *srv_addr6 =
1377					(struct sockaddr_in6 *)&server->dstaddr;
1378
1379		if (!ipv6_addr_equal(&addr6->sin6_addr,
1380				     &srv_addr6->sin6_addr))
1381			return false;
1382		if (addr6->sin6_scope_id != srv_addr6->sin6_scope_id)
1383			return false;
1384		break;
1385	}
1386	default:
1387		WARN_ON(1);
1388		return false; /* don't expect to be here */
1389	}
1390
1391	return true;
1392}
1393
1394static bool
1395match_security(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
1396{
1397	/*
1398	 * The select_sectype function should either return the ctx->sectype
1399	 * that was specified, or "Unspecified" if that sectype was not
1400	 * compatible with the given NEGOTIATE request.
1401	 */
1402	if (server->ops->select_sectype(server, ctx->sectype)
1403	     == Unspecified)
1404		return false;
1405
1406	/*
1407	 * Now check if signing mode is acceptable. No need to check
1408	 * global_secflags at this point since if MUST_SIGN is set then
1409	 * the server->sign had better be too.
1410	 */
1411	if (ctx->sign && !server->sign)
1412		return false;
1413
1414	return true;
1415}
1416
1417static bool dfs_src_pathname_equal(const char *s1, const char *s2)
1418{
1419	if (strlen(s1) != strlen(s2))
1420		return false;
1421	for (; *s1; s1++, s2++) {
1422		if (*s1 == '/' || *s1 == '\\') {
1423			if (*s2 != '/' && *s2 != '\\')
1424				return false;
1425		} else if (tolower(*s1) != tolower(*s2))
1426			return false;
1427	}
1428	return true;
1429}
1430
1431/* this function must be called with srv_lock held */
1432static int match_server(struct TCP_Server_Info *server, struct smb3_fs_context *ctx,
1433			bool dfs_super_cmp)
1434{
1435	struct sockaddr *addr = (struct sockaddr *)&ctx->dstaddr;
1436
1437	if (ctx->nosharesock)
1438		return 0;
1439
1440	/* this server does not share socket */
1441	if (server->nosharesock)
1442		return 0;
1443
1444	/* If multidialect negotiation see if existing sessions match one */
1445	if (strcmp(ctx->vals->version_string, SMB3ANY_VERSION_STRING) == 0) {
1446		if (server->vals->protocol_id < SMB30_PROT_ID)
1447			return 0;
1448	} else if (strcmp(ctx->vals->version_string,
1449		   SMBDEFAULT_VERSION_STRING) == 0) {
1450		if (server->vals->protocol_id < SMB21_PROT_ID)
1451			return 0;
1452	} else if ((server->vals != ctx->vals) || (server->ops != ctx->ops))
1453		return 0;
1454
1455	if (!net_eq(cifs_net_ns(server), current->nsproxy->net_ns))
1456		return 0;
1457
1458	if (!cifs_match_ipaddr((struct sockaddr *)&ctx->srcaddr,
1459			       (struct sockaddr *)&server->srcaddr))
1460		return 0;
1461	/*
1462	 * When matching DFS superblocks, we only check for original source pathname as the
1463	 * currently connected target might be different than the one parsed earlier in i.e.
1464	 * mount.cifs(8).
1465	 */
1466	if (dfs_super_cmp) {
1467		if (!ctx->source || !server->origin_fullpath ||
1468		    !dfs_src_pathname_equal(server->origin_fullpath, ctx->source))
1469			return 0;
1470	} else {
1471		/* Skip addr, hostname and port matching for DFS connections */
1472		if (server->leaf_fullpath) {
1473			if (!ctx->leaf_fullpath ||
1474			    strcasecmp(server->leaf_fullpath, ctx->leaf_fullpath))
1475				return 0;
1476		} else if (strcasecmp(server->hostname, ctx->server_hostname) ||
1477			   !match_server_address(server, addr) ||
1478			   !match_port(server, addr)) {
1479			return 0;
1480		}
1481	}
1482
1483	if (!match_security(server, ctx))
1484		return 0;
1485
1486	if (server->echo_interval != ctx->echo_interval * HZ)
1487		return 0;
1488
1489	if (server->rdma != ctx->rdma)
1490		return 0;
1491
1492	if (server->ignore_signature != ctx->ignore_signature)
1493		return 0;
1494
1495	if (server->min_offload != ctx->min_offload)
1496		return 0;
1497
1498	return 1;
1499}
1500
1501struct TCP_Server_Info *
1502cifs_find_tcp_session(struct smb3_fs_context *ctx)
1503{
1504	struct TCP_Server_Info *server;
1505
1506	spin_lock(&cifs_tcp_ses_lock);
1507	list_for_each_entry(server, &cifs_tcp_ses_list, tcp_ses_list) {
1508		spin_lock(&server->srv_lock);
1509		/*
1510		 * Skip ses channels since they're only handled in lower layers
1511		 * (e.g. cifs_send_recv).
1512		 */
1513		if (CIFS_SERVER_IS_CHAN(server) || !match_server(server, ctx, false)) {
1514			spin_unlock(&server->srv_lock);
1515			continue;
1516		}
1517		spin_unlock(&server->srv_lock);
1518
1519		++server->srv_count;
1520		spin_unlock(&cifs_tcp_ses_lock);
1521		cifs_dbg(FYI, "Existing tcp session with server found\n");
1522		return server;
1523	}
1524	spin_unlock(&cifs_tcp_ses_lock);
1525	return NULL;
1526}
1527
1528void
1529cifs_put_tcp_session(struct TCP_Server_Info *server, int from_reconnect)
1530{
1531	struct task_struct *task;
1532
1533	spin_lock(&cifs_tcp_ses_lock);
1534	if (--server->srv_count > 0) {
1535		spin_unlock(&cifs_tcp_ses_lock);
1536		return;
1537	}
1538
1539	/* srv_count can never go negative */
1540	WARN_ON(server->srv_count < 0);
1541
1542	put_net(cifs_net_ns(server));
1543
1544	list_del_init(&server->tcp_ses_list);
1545	spin_unlock(&cifs_tcp_ses_lock);
1546
1547	/* For secondary channels, we pick up ref-count on the primary server */
1548	if (CIFS_SERVER_IS_CHAN(server))
1549		cifs_put_tcp_session(server->primary_server, from_reconnect);
1550
1551	cancel_delayed_work_sync(&server->echo);
1552	cancel_delayed_work_sync(&server->resolve);
1553
1554	if (from_reconnect)
1555		/*
1556		 * Avoid deadlock here: reconnect work calls
1557		 * cifs_put_tcp_session() at its end. Need to be sure
1558		 * that reconnect work does nothing with server pointer after
1559		 * that step.
1560		 */
1561		cancel_delayed_work(&server->reconnect);
1562	else
1563		cancel_delayed_work_sync(&server->reconnect);
1564
1565	spin_lock(&server->srv_lock);
1566	server->tcpStatus = CifsExiting;
1567	spin_unlock(&server->srv_lock);
1568
1569	cifs_crypto_secmech_release(server);
1570
1571	kfree_sensitive(server->session_key.response);
1572	server->session_key.response = NULL;
1573	server->session_key.len = 0;
1574	kfree(server->hostname);
1575	server->hostname = NULL;
1576
1577	task = xchg(&server->tsk, NULL);
1578	if (task)
1579		send_sig(SIGKILL, task, 1);
1580}
1581
1582struct TCP_Server_Info *
1583cifs_get_tcp_session(struct smb3_fs_context *ctx,
1584		     struct TCP_Server_Info *primary_server)
1585{
1586	struct TCP_Server_Info *tcp_ses = NULL;
1587	int rc;
1588
1589	cifs_dbg(FYI, "UNC: %s\n", ctx->UNC);
1590
1591	/* see if we already have a matching tcp_ses */
1592	tcp_ses = cifs_find_tcp_session(ctx);
1593	if (tcp_ses)
1594		return tcp_ses;
1595
1596	tcp_ses = kzalloc(sizeof(struct TCP_Server_Info), GFP_KERNEL);
1597	if (!tcp_ses) {
1598		rc = -ENOMEM;
1599		goto out_err;
1600	}
1601
1602	tcp_ses->hostname = kstrdup(ctx->server_hostname, GFP_KERNEL);
1603	if (!tcp_ses->hostname) {
1604		rc = -ENOMEM;
1605		goto out_err;
1606	}
1607
1608	if (ctx->leaf_fullpath) {
1609		tcp_ses->leaf_fullpath = kstrdup(ctx->leaf_fullpath, GFP_KERNEL);
1610		if (!tcp_ses->leaf_fullpath) {
1611			rc = -ENOMEM;
1612			goto out_err;
1613		}
1614		tcp_ses->current_fullpath = tcp_ses->leaf_fullpath;
1615	}
1616
1617	if (ctx->nosharesock)
1618		tcp_ses->nosharesock = true;
1619
1620	tcp_ses->ops = ctx->ops;
1621	tcp_ses->vals = ctx->vals;
1622	cifs_set_net_ns(tcp_ses, get_net(current->nsproxy->net_ns));
1623
1624	tcp_ses->conn_id = atomic_inc_return(&tcpSesNextId);
1625	tcp_ses->noblockcnt = ctx->rootfs;
1626	tcp_ses->noblocksnd = ctx->noblocksnd || ctx->rootfs;
1627	tcp_ses->noautotune = ctx->noautotune;
1628	tcp_ses->tcp_nodelay = ctx->sockopt_tcp_nodelay;
1629	tcp_ses->rdma = ctx->rdma;
1630	tcp_ses->in_flight = 0;
1631	tcp_ses->max_in_flight = 0;
1632	tcp_ses->credits = 1;
1633	if (primary_server) {
1634		spin_lock(&cifs_tcp_ses_lock);
1635		++primary_server->srv_count;
1636		spin_unlock(&cifs_tcp_ses_lock);
1637		tcp_ses->primary_server = primary_server;
1638	}
1639	init_waitqueue_head(&tcp_ses->response_q);
1640	init_waitqueue_head(&tcp_ses->request_q);
1641	INIT_LIST_HEAD(&tcp_ses->pending_mid_q);
1642	mutex_init(&tcp_ses->_srv_mutex);
1643	memcpy(tcp_ses->workstation_RFC1001_name,
1644		ctx->source_rfc1001_name, RFC1001_NAME_LEN_WITH_NULL);
1645	memcpy(tcp_ses->server_RFC1001_name,
1646		ctx->target_rfc1001_name, RFC1001_NAME_LEN_WITH_NULL);
1647	tcp_ses->session_estab = false;
1648	tcp_ses->sequence_number = 0;
1649	tcp_ses->reconnect_instance = 1;
1650	tcp_ses->lstrp = jiffies;
1651	tcp_ses->compress_algorithm = cpu_to_le16(ctx->compression);
1652	spin_lock_init(&tcp_ses->req_lock);
1653	spin_lock_init(&tcp_ses->srv_lock);
1654	spin_lock_init(&tcp_ses->mid_lock);
1655	INIT_LIST_HEAD(&tcp_ses->tcp_ses_list);
1656	INIT_LIST_HEAD(&tcp_ses->smb_ses_list);
1657	INIT_DELAYED_WORK(&tcp_ses->echo, cifs_echo_request);
1658	INIT_DELAYED_WORK(&tcp_ses->resolve, cifs_resolve_server);
1659	INIT_DELAYED_WORK(&tcp_ses->reconnect, smb2_reconnect_server);
1660	mutex_init(&tcp_ses->reconnect_mutex);
1661#ifdef CONFIG_CIFS_DFS_UPCALL
1662	mutex_init(&tcp_ses->refpath_lock);
1663#endif
1664	memcpy(&tcp_ses->srcaddr, &ctx->srcaddr,
1665	       sizeof(tcp_ses->srcaddr));
1666	memcpy(&tcp_ses->dstaddr, &ctx->dstaddr,
1667		sizeof(tcp_ses->dstaddr));
1668	if (ctx->use_client_guid)
1669		memcpy(tcp_ses->client_guid, ctx->client_guid,
1670		       SMB2_CLIENT_GUID_SIZE);
1671	else
1672		generate_random_uuid(tcp_ses->client_guid);
1673	/*
1674	 * at this point we are the only ones with the pointer
1675	 * to the struct since the kernel thread not created yet
1676	 * no need to spinlock this init of tcpStatus or srv_count
1677	 */
1678	tcp_ses->tcpStatus = CifsNew;
1679	++tcp_ses->srv_count;
1680
1681	if (ctx->echo_interval >= SMB_ECHO_INTERVAL_MIN &&
1682		ctx->echo_interval <= SMB_ECHO_INTERVAL_MAX)
1683		tcp_ses->echo_interval = ctx->echo_interval * HZ;
1684	else
1685		tcp_ses->echo_interval = SMB_ECHO_INTERVAL_DEFAULT * HZ;
1686	if (tcp_ses->rdma) {
1687#ifndef CONFIG_CIFS_SMB_DIRECT
1688		cifs_dbg(VFS, "CONFIG_CIFS_SMB_DIRECT is not enabled\n");
1689		rc = -ENOENT;
1690		goto out_err_crypto_release;
1691#endif
1692		tcp_ses->smbd_conn = smbd_get_connection(
1693			tcp_ses, (struct sockaddr *)&ctx->dstaddr);
1694		if (tcp_ses->smbd_conn) {
1695			cifs_dbg(VFS, "RDMA transport established\n");
1696			rc = 0;
1697			goto smbd_connected;
1698		} else {
1699			rc = -ENOENT;
1700			goto out_err_crypto_release;
1701		}
1702	}
1703	rc = ip_connect(tcp_ses);
1704	if (rc < 0) {
1705		cifs_dbg(VFS, "Error connecting to socket. Aborting operation.\n");
1706		goto out_err_crypto_release;
1707	}
1708smbd_connected:
1709	/*
1710	 * since we're in a cifs function already, we know that
1711	 * this will succeed. No need for try_module_get().
1712	 */
1713	__module_get(THIS_MODULE);
1714	tcp_ses->tsk = kthread_run(cifs_demultiplex_thread,
1715				  tcp_ses, "cifsd");
1716	if (IS_ERR(tcp_ses->tsk)) {
1717		rc = PTR_ERR(tcp_ses->tsk);
1718		cifs_dbg(VFS, "error %d create cifsd thread\n", rc);
1719		module_put(THIS_MODULE);
1720		goto out_err_crypto_release;
1721	}
1722	tcp_ses->min_offload = ctx->min_offload;
1723	/*
1724	 * at this point we are the only ones with the pointer
1725	 * to the struct since the kernel thread not created yet
1726	 * no need to spinlock this update of tcpStatus
1727	 */
1728	spin_lock(&tcp_ses->srv_lock);
1729	tcp_ses->tcpStatus = CifsNeedNegotiate;
1730	spin_unlock(&tcp_ses->srv_lock);
1731
1732	if ((ctx->max_credits < 20) || (ctx->max_credits > 60000))
1733		tcp_ses->max_credits = SMB2_MAX_CREDITS_AVAILABLE;
1734	else
1735		tcp_ses->max_credits = ctx->max_credits;
1736
1737	tcp_ses->nr_targets = 1;
1738	tcp_ses->ignore_signature = ctx->ignore_signature;
1739	/* thread spawned, put it on the list */
1740	spin_lock(&cifs_tcp_ses_lock);
1741	list_add(&tcp_ses->tcp_ses_list, &cifs_tcp_ses_list);
1742	spin_unlock(&cifs_tcp_ses_lock);
1743
1744	/* queue echo request delayed work */
1745	queue_delayed_work(cifsiod_wq, &tcp_ses->echo, tcp_ses->echo_interval);
1746
1747	/* queue dns resolution delayed work */
1748	cifs_dbg(FYI, "%s: next dns resolution scheduled for %d seconds in the future\n",
1749		 __func__, SMB_DNS_RESOLVE_INTERVAL_DEFAULT);
1750
1751	queue_delayed_work(cifsiod_wq, &tcp_ses->resolve, (SMB_DNS_RESOLVE_INTERVAL_DEFAULT * HZ));
1752
1753	return tcp_ses;
1754
1755out_err_crypto_release:
1756	cifs_crypto_secmech_release(tcp_ses);
1757
1758	put_net(cifs_net_ns(tcp_ses));
1759
1760out_err:
1761	if (tcp_ses) {
1762		if (CIFS_SERVER_IS_CHAN(tcp_ses))
1763			cifs_put_tcp_session(tcp_ses->primary_server, false);
1764		kfree(tcp_ses->hostname);
1765		kfree(tcp_ses->leaf_fullpath);
1766		if (tcp_ses->ssocket)
1767			sock_release(tcp_ses->ssocket);
1768		kfree(tcp_ses);
1769	}
1770	return ERR_PTR(rc);
1771}
1772
1773/* this function must be called with ses_lock held */
1774static int match_session(struct cifs_ses *ses, struct smb3_fs_context *ctx)
1775{
1776	if (ctx->sectype != Unspecified &&
1777	    ctx->sectype != ses->sectype)
1778		return 0;
1779
1780	/*
1781	 * If an existing session is limited to less channels than
1782	 * requested, it should not be reused
1783	 */
1784	spin_lock(&ses->chan_lock);
1785	if (ses->chan_max < ctx->max_channels) {
1786		spin_unlock(&ses->chan_lock);
1787		return 0;
1788	}
1789	spin_unlock(&ses->chan_lock);
1790
1791	switch (ses->sectype) {
1792	case Kerberos:
1793		if (!uid_eq(ctx->cred_uid, ses->cred_uid))
1794			return 0;
1795		break;
1796	default:
1797		/* NULL username means anonymous session */
1798		if (ses->user_name == NULL) {
1799			if (!ctx->nullauth)
1800				return 0;
1801			break;
1802		}
1803
1804		/* anything else takes username/password */
1805		if (strncmp(ses->user_name,
1806			    ctx->username ? ctx->username : "",
1807			    CIFS_MAX_USERNAME_LEN))
1808			return 0;
1809		if ((ctx->username && strlen(ctx->username) != 0) &&
1810		    ses->password != NULL &&
1811		    strncmp(ses->password,
1812			    ctx->password ? ctx->password : "",
1813			    CIFS_MAX_PASSWORD_LEN))
1814			return 0;
1815	}
1816	return 1;
1817}
1818
1819/**
1820 * cifs_setup_ipc - helper to setup the IPC tcon for the session
1821 * @ses: smb session to issue the request on
1822 * @ctx: the superblock configuration context to use for building the
1823 *       new tree connection for the IPC (interprocess communication RPC)
1824 *
1825 * A new IPC connection is made and stored in the session
1826 * tcon_ipc. The IPC tcon has the same lifetime as the session.
1827 */
1828static int
1829cifs_setup_ipc(struct cifs_ses *ses, struct smb3_fs_context *ctx)
1830{
1831	int rc = 0, xid;
1832	struct cifs_tcon *tcon;
1833	char unc[SERVER_NAME_LENGTH + sizeof("//x/IPC$")] = {0};
1834	bool seal = false;
1835	struct TCP_Server_Info *server = ses->server;
1836
1837	/*
1838	 * If the mount request that resulted in the creation of the
1839	 * session requires encryption, force IPC to be encrypted too.
1840	 */
1841	if (ctx->seal) {
1842		if (server->capabilities & SMB2_GLOBAL_CAP_ENCRYPTION)
1843			seal = true;
1844		else {
1845			cifs_server_dbg(VFS,
1846				 "IPC: server doesn't support encryption\n");
1847			return -EOPNOTSUPP;
1848		}
1849	}
1850
1851	tcon = tconInfoAlloc();
1852	if (tcon == NULL)
1853		return -ENOMEM;
1854
1855	scnprintf(unc, sizeof(unc), "\\\\%s\\IPC$", server->hostname);
1856
1857	xid = get_xid();
1858	tcon->ses = ses;
1859	tcon->ipc = true;
1860	tcon->seal = seal;
1861	rc = server->ops->tree_connect(xid, ses, unc, tcon, ctx->local_nls);
1862	free_xid(xid);
1863
1864	if (rc) {
1865		cifs_server_dbg(VFS, "failed to connect to IPC (rc=%d)\n", rc);
1866		tconInfoFree(tcon);
1867		goto out;
1868	}
1869
1870	cifs_dbg(FYI, "IPC tcon rc=%d ipc tid=0x%x\n", rc, tcon->tid);
1871
1872	spin_lock(&tcon->tc_lock);
1873	tcon->status = TID_GOOD;
1874	spin_unlock(&tcon->tc_lock);
1875	ses->tcon_ipc = tcon;
1876out:
1877	return rc;
1878}
1879
1880/**
1881 * cifs_free_ipc - helper to release the session IPC tcon
1882 * @ses: smb session to unmount the IPC from
1883 *
1884 * Needs to be called everytime a session is destroyed.
1885 *
1886 * On session close, the IPC is closed and the server must release all tcons of the session.
1887 * No need to send a tree disconnect here.
1888 *
1889 * Besides, it will make the server to not close durable and resilient files on session close, as
1890 * specified in MS-SMB2 3.3.5.6 Receiving an SMB2 LOGOFF Request.
1891 */
1892static int
1893cifs_free_ipc(struct cifs_ses *ses)
1894{
1895	struct cifs_tcon *tcon = ses->tcon_ipc;
1896
1897	if (tcon == NULL)
1898		return 0;
1899
1900	tconInfoFree(tcon);
1901	ses->tcon_ipc = NULL;
1902	return 0;
1903}
1904
1905static struct cifs_ses *
1906cifs_find_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
1907{
1908	struct cifs_ses *ses;
1909
1910	spin_lock(&cifs_tcp_ses_lock);
1911	list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) {
1912		spin_lock(&ses->ses_lock);
1913		if (ses->ses_status == SES_EXITING) {
1914			spin_unlock(&ses->ses_lock);
1915			continue;
1916		}
1917		if (!match_session(ses, ctx)) {
1918			spin_unlock(&ses->ses_lock);
1919			continue;
1920		}
1921		spin_unlock(&ses->ses_lock);
1922
1923		++ses->ses_count;
1924		spin_unlock(&cifs_tcp_ses_lock);
1925		return ses;
1926	}
1927	spin_unlock(&cifs_tcp_ses_lock);
1928	return NULL;
1929}
1930
1931void cifs_put_smb_ses(struct cifs_ses *ses)
1932{
1933	unsigned int rc, xid;
1934	unsigned int chan_count;
1935	struct TCP_Server_Info *server = ses->server;
1936
1937	spin_lock(&ses->ses_lock);
1938	if (ses->ses_status == SES_EXITING) {
1939		spin_unlock(&ses->ses_lock);
1940		return;
1941	}
1942	spin_unlock(&ses->ses_lock);
1943
1944	cifs_dbg(FYI, "%s: ses_count=%d\n", __func__, ses->ses_count);
1945	cifs_dbg(FYI,
1946		 "%s: ses ipc: %s\n", __func__, ses->tcon_ipc ? ses->tcon_ipc->tree_name : "NONE");
1947
1948	spin_lock(&cifs_tcp_ses_lock);
1949	if (--ses->ses_count > 0) {
1950		spin_unlock(&cifs_tcp_ses_lock);
1951		return;
1952	}
1953	spin_unlock(&cifs_tcp_ses_lock);
1954
1955	/* ses_count can never go negative */
1956	WARN_ON(ses->ses_count < 0);
1957
1958	if (ses->ses_status == SES_GOOD)
1959		ses->ses_status = SES_EXITING;
1960
1961	cifs_free_ipc(ses);
1962
1963	if (ses->ses_status == SES_EXITING && server->ops->logoff) {
1964		xid = get_xid();
1965		rc = server->ops->logoff(xid, ses);
1966		if (rc)
1967			cifs_server_dbg(VFS, "%s: Session Logoff failure rc=%d\n",
1968				__func__, rc);
1969		_free_xid(xid);
1970	}
1971
1972	spin_lock(&cifs_tcp_ses_lock);
1973	list_del_init(&ses->smb_ses_list);
1974	spin_unlock(&cifs_tcp_ses_lock);
1975
1976	chan_count = ses->chan_count;
1977
1978	/* close any extra channels */
1979	if (chan_count > 1) {
1980		int i;
1981
1982		for (i = 1; i < chan_count; i++) {
1983			if (ses->chans[i].iface) {
1984				kref_put(&ses->chans[i].iface->refcount, release_iface);
1985				ses->chans[i].iface = NULL;
1986			}
1987			cifs_put_tcp_session(ses->chans[i].server, 0);
1988			ses->chans[i].server = NULL;
1989		}
1990	}
1991
1992	sesInfoFree(ses);
1993	cifs_put_tcp_session(server, 0);
1994}
1995
1996#ifdef CONFIG_KEYS
1997
1998/* strlen("cifs:a:") + CIFS_MAX_DOMAINNAME_LEN + 1 */
1999#define CIFSCREDS_DESC_SIZE (7 + CIFS_MAX_DOMAINNAME_LEN + 1)
2000
2001/* Populate username and pw fields from keyring if possible */
2002static int
2003cifs_set_cifscreds(struct smb3_fs_context *ctx, struct cifs_ses *ses)
2004{
2005	int rc = 0;
2006	int is_domain = 0;
2007	const char *delim, *payload;
2008	char *desc;
2009	ssize_t len;
2010	struct key *key;
2011	struct TCP_Server_Info *server = ses->server;
2012	struct sockaddr_in *sa;
2013	struct sockaddr_in6 *sa6;
2014	const struct user_key_payload *upayload;
2015
2016	desc = kmalloc(CIFSCREDS_DESC_SIZE, GFP_KERNEL);
2017	if (!desc)
2018		return -ENOMEM;
2019
2020	/* try to find an address key first */
2021	switch (server->dstaddr.ss_family) {
2022	case AF_INET:
2023		sa = (struct sockaddr_in *)&server->dstaddr;
2024		sprintf(desc, "cifs:a:%pI4", &sa->sin_addr.s_addr);
2025		break;
2026	case AF_INET6:
2027		sa6 = (struct sockaddr_in6 *)&server->dstaddr;
2028		sprintf(desc, "cifs:a:%pI6c", &sa6->sin6_addr.s6_addr);
2029		break;
2030	default:
2031		cifs_dbg(FYI, "Bad ss_family (%hu)\n",
2032			 server->dstaddr.ss_family);
2033		rc = -EINVAL;
2034		goto out_err;
2035	}
2036
2037	cifs_dbg(FYI, "%s: desc=%s\n", __func__, desc);
2038	key = request_key(&key_type_logon, desc, "");
2039	if (IS_ERR(key)) {
2040		if (!ses->domainName) {
2041			cifs_dbg(FYI, "domainName is NULL\n");
2042			rc = PTR_ERR(key);
2043			goto out_err;
2044		}
2045
2046		/* didn't work, try to find a domain key */
2047		sprintf(desc, "cifs:d:%s", ses->domainName);
2048		cifs_dbg(FYI, "%s: desc=%s\n", __func__, desc);
2049		key = request_key(&key_type_logon, desc, "");
2050		if (IS_ERR(key)) {
2051			rc = PTR_ERR(key);
2052			goto out_err;
2053		}
2054		is_domain = 1;
2055	}
2056
2057	down_read(&key->sem);
2058	upayload = user_key_payload_locked(key);
2059	if (IS_ERR_OR_NULL(upayload)) {
2060		rc = upayload ? PTR_ERR(upayload) : -EINVAL;
2061		goto out_key_put;
2062	}
2063
2064	/* find first : in payload */
2065	payload = upayload->data;
2066	delim = strnchr(payload, upayload->datalen, ':');
2067	cifs_dbg(FYI, "payload=%s\n", payload);
2068	if (!delim) {
2069		cifs_dbg(FYI, "Unable to find ':' in payload (datalen=%d)\n",
2070			 upayload->datalen);
2071		rc = -EINVAL;
2072		goto out_key_put;
2073	}
2074
2075	len = delim - payload;
2076	if (len > CIFS_MAX_USERNAME_LEN || len <= 0) {
2077		cifs_dbg(FYI, "Bad value from username search (len=%zd)\n",
2078			 len);
2079		rc = -EINVAL;
2080		goto out_key_put;
2081	}
2082
2083	ctx->username = kstrndup(payload, len, GFP_KERNEL);
2084	if (!ctx->username) {
2085		cifs_dbg(FYI, "Unable to allocate %zd bytes for username\n",
2086			 len);
2087		rc = -ENOMEM;
2088		goto out_key_put;
2089	}
2090	cifs_dbg(FYI, "%s: username=%s\n", __func__, ctx->username);
2091
2092	len = key->datalen - (len + 1);
2093	if (len > CIFS_MAX_PASSWORD_LEN || len <= 0) {
2094		cifs_dbg(FYI, "Bad len for password search (len=%zd)\n", len);
2095		rc = -EINVAL;
2096		kfree(ctx->username);
2097		ctx->username = NULL;
2098		goto out_key_put;
2099	}
2100
2101	++delim;
2102	ctx->password = kstrndup(delim, len, GFP_KERNEL);
2103	if (!ctx->password) {
2104		cifs_dbg(FYI, "Unable to allocate %zd bytes for password\n",
2105			 len);
2106		rc = -ENOMEM;
2107		kfree(ctx->username);
2108		ctx->username = NULL;
2109		goto out_key_put;
2110	}
2111
2112	/*
2113	 * If we have a domain key then we must set the domainName in the
2114	 * for the request.
2115	 */
2116	if (is_domain && ses->domainName) {
2117		ctx->domainname = kstrdup(ses->domainName, GFP_KERNEL);
2118		if (!ctx->domainname) {
2119			cifs_dbg(FYI, "Unable to allocate %zd bytes for domain\n",
2120				 len);
2121			rc = -ENOMEM;
2122			kfree(ctx->username);
2123			ctx->username = NULL;
2124			kfree_sensitive(ctx->password);
2125			ctx->password = NULL;
2126			goto out_key_put;
2127		}
2128	}
2129
2130	strscpy(ctx->workstation_name, ses->workstation_name, sizeof(ctx->workstation_name));
2131
2132out_key_put:
2133	up_read(&key->sem);
2134	key_put(key);
2135out_err:
2136	kfree(desc);
2137	cifs_dbg(FYI, "%s: returning %d\n", __func__, rc);
2138	return rc;
2139}
2140#else /* ! CONFIG_KEYS */
2141static inline int
2142cifs_set_cifscreds(struct smb3_fs_context *ctx __attribute__((unused)),
2143		   struct cifs_ses *ses __attribute__((unused)))
2144{
2145	return -ENOSYS;
2146}
2147#endif /* CONFIG_KEYS */
2148
2149/**
2150 * cifs_get_smb_ses - get a session matching @ctx data from @server
2151 * @server: server to setup the session to
2152 * @ctx: superblock configuration context to use to setup the session
2153 *
2154 * This function assumes it is being called from cifs_mount() where we
2155 * already got a server reference (server refcount +1). See
2156 * cifs_get_tcon() for refcount explanations.
2157 */
2158struct cifs_ses *
2159cifs_get_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
2160{
2161	int rc = 0;
2162	unsigned int xid;
2163	struct cifs_ses *ses;
2164	struct sockaddr_in *addr = (struct sockaddr_in *)&server->dstaddr;
2165	struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&server->dstaddr;
2166
2167	xid = get_xid();
2168
2169	ses = cifs_find_smb_ses(server, ctx);
2170	if (ses) {
2171		cifs_dbg(FYI, "Existing smb sess found (status=%d)\n",
2172			 ses->ses_status);
2173
2174		spin_lock(&ses->chan_lock);
2175		if (cifs_chan_needs_reconnect(ses, server)) {
2176			spin_unlock(&ses->chan_lock);
2177			cifs_dbg(FYI, "Session needs reconnect\n");
2178
2179			mutex_lock(&ses->session_mutex);
2180			rc = cifs_negotiate_protocol(xid, ses, server);
2181			if (rc) {
2182				mutex_unlock(&ses->session_mutex);
2183				/* problem -- put our ses reference */
2184				cifs_put_smb_ses(ses);
2185				free_xid(xid);
2186				return ERR_PTR(rc);
2187			}
2188
2189			rc = cifs_setup_session(xid, ses, server,
2190						ctx->local_nls);
2191			if (rc) {
2192				mutex_unlock(&ses->session_mutex);
2193				/* problem -- put our reference */
2194				cifs_put_smb_ses(ses);
2195				free_xid(xid);
2196				return ERR_PTR(rc);
2197			}
2198			mutex_unlock(&ses->session_mutex);
2199
2200			spin_lock(&ses->chan_lock);
2201		}
2202		spin_unlock(&ses->chan_lock);
2203
2204		/* existing SMB ses has a server reference already */
2205		cifs_put_tcp_session(server, 0);
2206		free_xid(xid);
2207		return ses;
2208	}
2209
2210	rc = -ENOMEM;
2211
2212	cifs_dbg(FYI, "Existing smb sess not found\n");
2213	ses = sesInfoAlloc();
2214	if (ses == NULL)
2215		goto get_ses_fail;
2216
2217	/* new SMB session uses our server ref */
2218	ses->server = server;
2219	if (server->dstaddr.ss_family == AF_INET6)
2220		sprintf(ses->ip_addr, "%pI6", &addr6->sin6_addr);
2221	else
2222		sprintf(ses->ip_addr, "%pI4", &addr->sin_addr);
2223
2224	if (ctx->username) {
2225		ses->user_name = kstrdup(ctx->username, GFP_KERNEL);
2226		if (!ses->user_name)
2227			goto get_ses_fail;
2228	}
2229
2230	/* ctx->password freed at unmount */
2231	if (ctx->password) {
2232		ses->password = kstrdup(ctx->password, GFP_KERNEL);
2233		if (!ses->password)
2234			goto get_ses_fail;
2235	}
2236	if (ctx->domainname) {
2237		ses->domainName = kstrdup(ctx->domainname, GFP_KERNEL);
2238		if (!ses->domainName)
2239			goto get_ses_fail;
2240	}
2241
2242	strscpy(ses->workstation_name, ctx->workstation_name, sizeof(ses->workstation_name));
2243
2244	if (ctx->domainauto)
2245		ses->domainAuto = ctx->domainauto;
2246	ses->cred_uid = ctx->cred_uid;
2247	ses->linux_uid = ctx->linux_uid;
2248
2249	ses->sectype = ctx->sectype;
2250	ses->sign = ctx->sign;
2251
2252	/* add server as first channel */
2253	spin_lock(&ses->chan_lock);
2254	ses->chans[0].server = server;
2255	ses->chan_count = 1;
2256	ses->chan_max = ctx->multichannel ? ctx->max_channels:1;
2257	ses->chans_need_reconnect = 1;
2258	spin_unlock(&ses->chan_lock);
2259
2260	mutex_lock(&ses->session_mutex);
2261	rc = cifs_negotiate_protocol(xid, ses, server);
2262	if (!rc)
2263		rc = cifs_setup_session(xid, ses, server, ctx->local_nls);
2264	mutex_unlock(&ses->session_mutex);
2265
2266	/* each channel uses a different signing key */
2267	spin_lock(&ses->chan_lock);
2268	memcpy(ses->chans[0].signkey, ses->smb3signingkey,
2269	       sizeof(ses->smb3signingkey));
2270	spin_unlock(&ses->chan_lock);
2271
2272	if (rc)
2273		goto get_ses_fail;
2274
2275	/*
2276	 * success, put it on the list and add it as first channel
2277	 * note: the session becomes active soon after this. So you'll
2278	 * need to lock before changing something in the session.
2279	 */
2280	spin_lock(&cifs_tcp_ses_lock);
2281	list_add(&ses->smb_ses_list, &server->smb_ses_list);
2282	spin_unlock(&cifs_tcp_ses_lock);
2283
2284	cifs_setup_ipc(ses, ctx);
2285
2286	free_xid(xid);
2287
2288	return ses;
2289
2290get_ses_fail:
2291	sesInfoFree(ses);
2292	free_xid(xid);
2293	return ERR_PTR(rc);
2294}
2295
2296/* this function must be called with tc_lock held */
2297static int match_tcon(struct cifs_tcon *tcon, struct smb3_fs_context *ctx, bool dfs_super_cmp)
2298{
2299	if (tcon->status == TID_EXITING)
2300		return 0;
2301	/* Skip UNC validation when matching DFS superblocks */
2302	if (!dfs_super_cmp && strncmp(tcon->tree_name, ctx->UNC, MAX_TREE_SIZE))
2303		return 0;
2304	if (tcon->seal != ctx->seal)
2305		return 0;
2306	if (tcon->snapshot_time != ctx->snapshot_time)
2307		return 0;
2308	if (tcon->handle_timeout != ctx->handle_timeout)
2309		return 0;
2310	if (tcon->no_lease != ctx->no_lease)
2311		return 0;
2312	if (tcon->nodelete != ctx->nodelete)
2313		return 0;
2314	return 1;
2315}
2316
2317static struct cifs_tcon *
2318cifs_find_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx)
2319{
2320	struct cifs_tcon *tcon;
2321
2322	spin_lock(&cifs_tcp_ses_lock);
2323	list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
2324		spin_lock(&tcon->tc_lock);
2325		if (!match_tcon(tcon, ctx, false)) {
2326			spin_unlock(&tcon->tc_lock);
2327			continue;
2328		}
2329		++tcon->tc_count;
2330		spin_unlock(&tcon->tc_lock);
2331		spin_unlock(&cifs_tcp_ses_lock);
2332		return tcon;
2333	}
2334	spin_unlock(&cifs_tcp_ses_lock);
2335	return NULL;
2336}
2337
2338void
2339cifs_put_tcon(struct cifs_tcon *tcon)
2340{
2341	unsigned int xid;
2342	struct cifs_ses *ses;
2343
2344	/*
2345	 * IPC tcon share the lifetime of their session and are
2346	 * destroyed in the session put function
2347	 */
2348	if (tcon == NULL || tcon->ipc)
2349		return;
2350
2351	ses = tcon->ses;
2352	cifs_dbg(FYI, "%s: tc_count=%d\n", __func__, tcon->tc_count);
2353	spin_lock(&cifs_tcp_ses_lock);
2354	spin_lock(&tcon->tc_lock);
2355	if (--tcon->tc_count > 0) {
2356		spin_unlock(&tcon->tc_lock);
2357		spin_unlock(&cifs_tcp_ses_lock);
2358		return;
2359	}
2360
2361	/* tc_count can never go negative */
2362	WARN_ON(tcon->tc_count < 0);
2363
2364	list_del_init(&tcon->tcon_list);
2365	spin_unlock(&tcon->tc_lock);
2366	spin_unlock(&cifs_tcp_ses_lock);
2367
2368	/* cancel polling of interfaces */
2369	cancel_delayed_work_sync(&tcon->query_interfaces);
2370
2371	if (tcon->use_witness) {
2372		int rc;
2373
2374		rc = cifs_swn_unregister(tcon);
2375		if (rc < 0) {
2376			cifs_dbg(VFS, "%s: Failed to unregister for witness notifications: %d\n",
2377					__func__, rc);
2378		}
2379	}
2380
2381	xid = get_xid();
2382	if (ses->server->ops->tree_disconnect)
2383		ses->server->ops->tree_disconnect(xid, tcon);
2384	_free_xid(xid);
2385
2386	cifs_fscache_release_super_cookie(tcon);
2387	tconInfoFree(tcon);
2388	cifs_put_smb_ses(ses);
2389}
2390
2391/**
2392 * cifs_get_tcon - get a tcon matching @ctx data from @ses
2393 * @ses: smb session to issue the request on
2394 * @ctx: the superblock configuration context to use for building the
2395 *
2396 * - tcon refcount is the number of mount points using the tcon.
2397 * - ses refcount is the number of tcon using the session.
2398 *
2399 * 1. This function assumes it is being called from cifs_mount() where
2400 *    we already got a session reference (ses refcount +1).
2401 *
2402 * 2. Since we're in the context of adding a mount point, the end
2403 *    result should be either:
2404 *
2405 * a) a new tcon already allocated with refcount=1 (1 mount point) and
2406 *    its session refcount incremented (1 new tcon). This +1 was
2407 *    already done in (1).
2408 *
2409 * b) an existing tcon with refcount+1 (add a mount point to it) and
2410 *    identical ses refcount (no new tcon). Because of (1) we need to
2411 *    decrement the ses refcount.
2412 */
2413static struct cifs_tcon *
2414cifs_get_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx)
2415{
2416	int rc, xid;
2417	struct cifs_tcon *tcon;
2418
2419	tcon = cifs_find_tcon(ses, ctx);
2420	if (tcon) {
2421		/*
2422		 * tcon has refcount already incremented but we need to
2423		 * decrement extra ses reference gotten by caller (case b)
2424		 */
2425		cifs_dbg(FYI, "Found match on UNC path\n");
2426		cifs_put_smb_ses(ses);
2427		return tcon;
2428	}
2429
2430	if (!ses->server->ops->tree_connect) {
2431		rc = -ENOSYS;
2432		goto out_fail;
2433	}
2434
2435	tcon = tconInfoAlloc();
2436	if (tcon == NULL) {
2437		rc = -ENOMEM;
2438		goto out_fail;
2439	}
2440
2441	if (ctx->snapshot_time) {
2442		if (ses->server->vals->protocol_id == 0) {
2443			cifs_dbg(VFS,
2444			     "Use SMB2 or later for snapshot mount option\n");
2445			rc = -EOPNOTSUPP;
2446			goto out_fail;
2447		} else
2448			tcon->snapshot_time = ctx->snapshot_time;
2449	}
2450
2451	if (ctx->handle_timeout) {
2452		if (ses->server->vals->protocol_id == 0) {
2453			cifs_dbg(VFS,
2454			     "Use SMB2.1 or later for handle timeout option\n");
2455			rc = -EOPNOTSUPP;
2456			goto out_fail;
2457		} else
2458			tcon->handle_timeout = ctx->handle_timeout;
2459	}
2460
2461	tcon->ses = ses;
2462	if (ctx->password) {
2463		tcon->password = kstrdup(ctx->password, GFP_KERNEL);
2464		if (!tcon->password) {
2465			rc = -ENOMEM;
2466			goto out_fail;
2467		}
2468	}
2469
2470	if (ctx->seal) {
2471		if (ses->server->vals->protocol_id == 0) {
2472			cifs_dbg(VFS,
2473				 "SMB3 or later required for encryption\n");
2474			rc = -EOPNOTSUPP;
2475			goto out_fail;
2476		} else if (tcon->ses->server->capabilities &
2477					SMB2_GLOBAL_CAP_ENCRYPTION)
2478			tcon->seal = true;
2479		else {
2480			cifs_dbg(VFS, "Encryption is not supported on share\n");
2481			rc = -EOPNOTSUPP;
2482			goto out_fail;
2483		}
2484	}
2485
2486	if (ctx->linux_ext) {
2487		if (ses->server->posix_ext_supported) {
2488			tcon->posix_extensions = true;
2489			pr_warn_once("SMB3.11 POSIX Extensions are experimental\n");
2490		} else if ((ses->server->vals->protocol_id == SMB311_PROT_ID) ||
2491		    (strcmp(ses->server->vals->version_string,
2492		     SMB3ANY_VERSION_STRING) == 0) ||
2493		    (strcmp(ses->server->vals->version_string,
2494		     SMBDEFAULT_VERSION_STRING) == 0)) {
2495			cifs_dbg(VFS, "Server does not support mounting with posix SMB3.11 extensions\n");
2496			rc = -EOPNOTSUPP;
2497			goto out_fail;
2498		} else {
2499			cifs_dbg(VFS, "Check vers= mount option. SMB3.11 "
2500				"disabled but required for POSIX extensions\n");
2501			rc = -EOPNOTSUPP;
2502			goto out_fail;
2503		}
2504	}
2505
2506	xid = get_xid();
2507	rc = ses->server->ops->tree_connect(xid, ses, ctx->UNC, tcon,
2508					    ctx->local_nls);
2509	free_xid(xid);
2510	cifs_dbg(FYI, "Tcon rc = %d\n", rc);
2511	if (rc)
2512		goto out_fail;
2513
2514	tcon->use_persistent = false;
2515	/* check if SMB2 or later, CIFS does not support persistent handles */
2516	if (ctx->persistent) {
2517		if (ses->server->vals->protocol_id == 0) {
2518			cifs_dbg(VFS,
2519			     "SMB3 or later required for persistent handles\n");
2520			rc = -EOPNOTSUPP;
2521			goto out_fail;
2522		} else if (ses->server->capabilities &
2523			   SMB2_GLOBAL_CAP_PERSISTENT_HANDLES)
2524			tcon->use_persistent = true;
2525		else /* persistent handles requested but not supported */ {
2526			cifs_dbg(VFS,
2527				"Persistent handles not supported on share\n");
2528			rc = -EOPNOTSUPP;
2529			goto out_fail;
2530		}
2531	} else if ((tcon->capabilities & SMB2_SHARE_CAP_CONTINUOUS_AVAILABILITY)
2532	     && (ses->server->capabilities & SMB2_GLOBAL_CAP_PERSISTENT_HANDLES)
2533	     && (ctx->nopersistent == false)) {
2534		cifs_dbg(FYI, "enabling persistent handles\n");
2535		tcon->use_persistent = true;
2536	} else if (ctx->resilient) {
2537		if (ses->server->vals->protocol_id == 0) {
2538			cifs_dbg(VFS,
2539			     "SMB2.1 or later required for resilient handles\n");
2540			rc = -EOPNOTSUPP;
2541			goto out_fail;
2542		}
2543		tcon->use_resilient = true;
2544	}
2545
2546	tcon->use_witness = false;
2547	if (IS_ENABLED(CONFIG_CIFS_SWN_UPCALL) && ctx->witness) {
2548		if (ses->server->vals->protocol_id >= SMB30_PROT_ID) {
2549			if (tcon->capabilities & SMB2_SHARE_CAP_CLUSTER) {
2550				/*
2551				 * Set witness in use flag in first place
2552				 * to retry registration in the echo task
2553				 */
2554				tcon->use_witness = true;
2555				/* And try to register immediately */
2556				rc = cifs_swn_register(tcon);
2557				if (rc < 0) {
2558					cifs_dbg(VFS, "Failed to register for witness notifications: %d\n", rc);
2559					goto out_fail;
2560				}
2561			} else {
2562				/* TODO: try to extend for non-cluster uses (eg multichannel) */
2563				cifs_dbg(VFS, "witness requested on mount but no CLUSTER capability on share\n");
2564				rc = -EOPNOTSUPP;
2565				goto out_fail;
2566			}
2567		} else {
2568			cifs_dbg(VFS, "SMB3 or later required for witness option\n");
2569			rc = -EOPNOTSUPP;
2570			goto out_fail;
2571		}
2572	}
2573
2574	/* If the user really knows what they are doing they can override */
2575	if (tcon->share_flags & SMB2_SHAREFLAG_NO_CACHING) {
2576		if (ctx->cache_ro)
2577			cifs_dbg(VFS, "cache=ro requested on mount but NO_CACHING flag set on share\n");
2578		else if (ctx->cache_rw)
2579			cifs_dbg(VFS, "cache=singleclient requested on mount but NO_CACHING flag set on share\n");
2580	}
2581
2582	if (ctx->no_lease) {
2583		if (ses->server->vals->protocol_id == 0) {
2584			cifs_dbg(VFS,
2585				"SMB2 or later required for nolease option\n");
2586			rc = -EOPNOTSUPP;
2587			goto out_fail;
2588		} else
2589			tcon->no_lease = ctx->no_lease;
2590	}
2591
2592	/*
2593	 * We can have only one retry value for a connection to a share so for
2594	 * resources mounted more than once to the same server share the last
2595	 * value passed in for the retry flag is used.
2596	 */
2597	tcon->retry = ctx->retry;
2598	tcon->nocase = ctx->nocase;
2599	tcon->broken_sparse_sup = ctx->no_sparse;
2600	if (ses->server->capabilities & SMB2_GLOBAL_CAP_DIRECTORY_LEASING)
2601		tcon->nohandlecache = ctx->nohandlecache;
2602	else
2603		tcon->nohandlecache = true;
2604	tcon->nodelete = ctx->nodelete;
2605	tcon->local_lease = ctx->local_lease;
2606	INIT_LIST_HEAD(&tcon->pending_opens);
2607	tcon->status = TID_GOOD;
2608
2609	INIT_DELAYED_WORK(&tcon->query_interfaces,
2610			  smb2_query_server_interfaces);
2611	if (ses->server->dialect >= SMB30_PROT_ID &&
2612	    (ses->server->capabilities & SMB2_GLOBAL_CAP_MULTI_CHANNEL)) {
2613		/* schedule query interfaces poll */
2614		queue_delayed_work(cifsiod_wq, &tcon->query_interfaces,
2615				   (SMB_INTERFACE_POLL_INTERVAL * HZ));
2616	}
2617
2618	spin_lock(&cifs_tcp_ses_lock);
2619	list_add(&tcon->tcon_list, &ses->tcon_list);
2620	spin_unlock(&cifs_tcp_ses_lock);
2621
2622	return tcon;
2623
2624out_fail:
2625	tconInfoFree(tcon);
2626	return ERR_PTR(rc);
2627}
2628
2629void
2630cifs_put_tlink(struct tcon_link *tlink)
2631{
2632	if (!tlink || IS_ERR(tlink))
2633		return;
2634
2635	if (!atomic_dec_and_test(&tlink->tl_count) ||
2636	    test_bit(TCON_LINK_IN_TREE, &tlink->tl_flags)) {
2637		tlink->tl_time = jiffies;
2638		return;
2639	}
2640
2641	if (!IS_ERR(tlink_tcon(tlink)))
2642		cifs_put_tcon(tlink_tcon(tlink));
2643	kfree(tlink);
2644	return;
2645}
2646
2647static int
2648compare_mount_options(struct super_block *sb, struct cifs_mnt_data *mnt_data)
2649{
2650	struct cifs_sb_info *old = CIFS_SB(sb);
2651	struct cifs_sb_info *new = mnt_data->cifs_sb;
2652	unsigned int oldflags = old->mnt_cifs_flags & CIFS_MOUNT_MASK;
2653	unsigned int newflags = new->mnt_cifs_flags & CIFS_MOUNT_MASK;
2654
2655	if ((sb->s_flags & CIFS_MS_MASK) != (mnt_data->flags & CIFS_MS_MASK))
2656		return 0;
2657
2658	if (old->mnt_cifs_serverino_autodisabled)
2659		newflags &= ~CIFS_MOUNT_SERVER_INUM;
2660
2661	if (oldflags != newflags)
2662		return 0;
2663
2664	/*
2665	 * We want to share sb only if we don't specify an r/wsize or
2666	 * specified r/wsize is greater than or equal to existing one.
2667	 */
2668	if (new->ctx->wsize && new->ctx->wsize < old->ctx->wsize)
2669		return 0;
2670
2671	if (new->ctx->rsize && new->ctx->rsize < old->ctx->rsize)
2672		return 0;
2673
2674	if (!uid_eq(old->ctx->linux_uid, new->ctx->linux_uid) ||
2675	    !gid_eq(old->ctx->linux_gid, new->ctx->linux_gid))
2676		return 0;
2677
2678	if (old->ctx->file_mode != new->ctx->file_mode ||
2679	    old->ctx->dir_mode != new->ctx->dir_mode)
2680		return 0;
2681
2682	if (strcmp(old->local_nls->charset, new->local_nls->charset))
2683		return 0;
2684
2685	if (old->ctx->acregmax != new->ctx->acregmax)
2686		return 0;
2687	if (old->ctx->acdirmax != new->ctx->acdirmax)
2688		return 0;
2689	if (old->ctx->closetimeo != new->ctx->closetimeo)
2690		return 0;
2691
2692	return 1;
2693}
2694
2695static int
2696match_prepath(struct super_block *sb, struct cifs_mnt_data *mnt_data)
2697{
2698	struct cifs_sb_info *old = CIFS_SB(sb);
2699	struct cifs_sb_info *new = mnt_data->cifs_sb;
2700	bool old_set = (old->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH) &&
2701		old->prepath;
2702	bool new_set = (new->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH) &&
2703		new->prepath;
2704
2705	if (old_set && new_set && !strcmp(new->prepath, old->prepath))
2706		return 1;
2707	else if (!old_set && !new_set)
2708		return 1;
2709
2710	return 0;
2711}
2712
2713int
2714cifs_match_super(struct super_block *sb, void *data)
2715{
2716	struct cifs_mnt_data *mnt_data = data;
2717	struct smb3_fs_context *ctx;
2718	struct cifs_sb_info *cifs_sb;
2719	struct TCP_Server_Info *tcp_srv;
2720	struct cifs_ses *ses;
2721	struct cifs_tcon *tcon;
2722	struct tcon_link *tlink;
2723	bool dfs_super_cmp;
2724	int rc = 0;
2725
2726	spin_lock(&cifs_tcp_ses_lock);
2727	cifs_sb = CIFS_SB(sb);
2728	tlink = cifs_get_tlink(cifs_sb_master_tlink(cifs_sb));
2729	if (tlink == NULL) {
2730		/* can not match superblock if tlink were ever null */
2731		spin_unlock(&cifs_tcp_ses_lock);
2732		return 0;
2733	}
2734	tcon = tlink_tcon(tlink);
2735	ses = tcon->ses;
2736	tcp_srv = ses->server;
2737
2738	dfs_super_cmp = IS_ENABLED(CONFIG_CIFS_DFS_UPCALL) && tcp_srv->origin_fullpath;
2739
2740	ctx = mnt_data->ctx;
2741
2742	spin_lock(&tcp_srv->srv_lock);
2743	spin_lock(&ses->ses_lock);
2744	spin_lock(&tcon->tc_lock);
2745	if (!match_server(tcp_srv, ctx, dfs_super_cmp) ||
2746	    !match_session(ses, ctx) ||
2747	    !match_tcon(tcon, ctx, dfs_super_cmp) ||
2748	    !match_prepath(sb, mnt_data)) {
2749		rc = 0;
2750		goto out;
2751	}
2752
2753	rc = compare_mount_options(sb, mnt_data);
2754out:
2755	spin_unlock(&tcon->tc_lock);
2756	spin_unlock(&ses->ses_lock);
2757	spin_unlock(&tcp_srv->srv_lock);
2758
2759	spin_unlock(&cifs_tcp_ses_lock);
2760	cifs_put_tlink(tlink);
2761	return rc;
2762}
2763
2764#ifdef CONFIG_DEBUG_LOCK_ALLOC
2765static struct lock_class_key cifs_key[2];
2766static struct lock_class_key cifs_slock_key[2];
2767
2768static inline void
2769cifs_reclassify_socket4(struct socket *sock)
2770{
2771	struct sock *sk = sock->sk;
2772	BUG_ON(!sock_allow_reclassification(sk));
2773	sock_lock_init_class_and_name(sk, "slock-AF_INET-CIFS",
2774		&cifs_slock_key[0], "sk_lock-AF_INET-CIFS", &cifs_key[0]);
2775}
2776
2777static inline void
2778cifs_reclassify_socket6(struct socket *sock)
2779{
2780	struct sock *sk = sock->sk;
2781	BUG_ON(!sock_allow_reclassification(sk));
2782	sock_lock_init_class_and_name(sk, "slock-AF_INET6-CIFS",
2783		&cifs_slock_key[1], "sk_lock-AF_INET6-CIFS", &cifs_key[1]);
2784}
2785#else
2786static inline void
2787cifs_reclassify_socket4(struct socket *sock)
2788{
2789}
2790
2791static inline void
2792cifs_reclassify_socket6(struct socket *sock)
2793{
2794}
2795#endif
2796
2797/* See RFC1001 section 14 on representation of Netbios names */
2798static void rfc1002mangle(char *target, char *source, unsigned int length)
2799{
2800	unsigned int i, j;
2801
2802	for (i = 0, j = 0; i < (length); i++) {
2803		/* mask a nibble at a time and encode */
2804		target[j] = 'A' + (0x0F & (source[i] >> 4));
2805		target[j+1] = 'A' + (0x0F & source[i]);
2806		j += 2;
2807	}
2808
2809}
2810
2811static int
2812bind_socket(struct TCP_Server_Info *server)
2813{
2814	int rc = 0;
2815	if (server->srcaddr.ss_family != AF_UNSPEC) {
2816		/* Bind to the specified local IP address */
2817		struct socket *socket = server->ssocket;
2818		rc = socket->ops->bind(socket,
2819				       (struct sockaddr *) &server->srcaddr,
2820				       sizeof(server->srcaddr));
2821		if (rc < 0) {
2822			struct sockaddr_in *saddr4;
2823			struct sockaddr_in6 *saddr6;
2824			saddr4 = (struct sockaddr_in *)&server->srcaddr;
2825			saddr6 = (struct sockaddr_in6 *)&server->srcaddr;
2826			if (saddr6->sin6_family == AF_INET6)
2827				cifs_server_dbg(VFS, "Failed to bind to: %pI6c, error: %d\n",
2828					 &saddr6->sin6_addr, rc);
2829			else
2830				cifs_server_dbg(VFS, "Failed to bind to: %pI4, error: %d\n",
2831					 &saddr4->sin_addr.s_addr, rc);
2832		}
2833	}
2834	return rc;
2835}
2836
2837static int
2838ip_rfc1001_connect(struct TCP_Server_Info *server)
2839{
2840	int rc = 0;
2841	/*
2842	 * some servers require RFC1001 sessinit before sending
2843	 * negprot - BB check reconnection in case where second
2844	 * sessinit is sent but no second negprot
2845	 */
2846	struct rfc1002_session_packet *ses_init_buf;
2847	unsigned int req_noscope_len;
2848	struct smb_hdr *smb_buf;
2849
2850	ses_init_buf = kzalloc(sizeof(struct rfc1002_session_packet),
2851			       GFP_KERNEL);
2852
2853	if (ses_init_buf) {
2854		ses_init_buf->trailer.session_req.called_len = 32;
2855
2856		if (server->server_RFC1001_name[0] != 0)
2857			rfc1002mangle(ses_init_buf->trailer.
2858				      session_req.called_name,
2859				      server->server_RFC1001_name,
2860				      RFC1001_NAME_LEN_WITH_NULL);
2861		else
2862			rfc1002mangle(ses_init_buf->trailer.
2863				      session_req.called_name,
2864				      DEFAULT_CIFS_CALLED_NAME,
2865				      RFC1001_NAME_LEN_WITH_NULL);
2866
2867		ses_init_buf->trailer.session_req.calling_len = 32;
2868
2869		/*
2870		 * calling name ends in null (byte 16) from old smb
2871		 * convention.
2872		 */
2873		if (server->workstation_RFC1001_name[0] != 0)
2874			rfc1002mangle(ses_init_buf->trailer.
2875				      session_req.calling_name,
2876				      server->workstation_RFC1001_name,
2877				      RFC1001_NAME_LEN_WITH_NULL);
2878		else
2879			rfc1002mangle(ses_init_buf->trailer.
2880				      session_req.calling_name,
2881				      "LINUX_CIFS_CLNT",
2882				      RFC1001_NAME_LEN_WITH_NULL);
2883
2884		ses_init_buf->trailer.session_req.scope1 = 0;
2885		ses_init_buf->trailer.session_req.scope2 = 0;
2886		smb_buf = (struct smb_hdr *)ses_init_buf;
2887
2888		/* sizeof RFC1002_SESSION_REQUEST with no scopes */
2889		req_noscope_len = sizeof(struct rfc1002_session_packet) - 2;
2890
2891		/* == cpu_to_be32(0x81000044) */
2892		smb_buf->smb_buf_length =
2893			cpu_to_be32((RFC1002_SESSION_REQUEST << 24) | req_noscope_len);
2894		rc = smb_send(server, smb_buf, 0x44);
2895		kfree(ses_init_buf);
2896		/*
2897		 * RFC1001 layer in at least one server
2898		 * requires very short break before negprot
2899		 * presumably because not expecting negprot
2900		 * to follow so fast.  This is a simple
2901		 * solution that works without
2902		 * complicating the code and causes no
2903		 * significant slowing down on mount
2904		 * for everyone else
2905		 */
2906		usleep_range(1000, 2000);
2907	}
2908	/*
2909	 * else the negprot may still work without this
2910	 * even though malloc failed
2911	 */
2912
2913	return rc;
2914}
2915
2916static int
2917generic_ip_connect(struct TCP_Server_Info *server)
2918{
2919	int rc = 0;
2920	__be16 sport;
2921	int slen, sfamily;
2922	struct socket *socket = server->ssocket;
2923	struct sockaddr *saddr;
2924
2925	saddr = (struct sockaddr *) &server->dstaddr;
2926
2927	if (server->dstaddr.ss_family == AF_INET6) {
2928		struct sockaddr_in6 *ipv6 = (struct sockaddr_in6 *)&server->dstaddr;
2929
2930		sport = ipv6->sin6_port;
2931		slen = sizeof(struct sockaddr_in6);
2932		sfamily = AF_INET6;
2933		cifs_dbg(FYI, "%s: connecting to [%pI6]:%d\n", __func__, &ipv6->sin6_addr,
2934				ntohs(sport));
2935	} else {
2936		struct sockaddr_in *ipv4 = (struct sockaddr_in *)&server->dstaddr;
2937
2938		sport = ipv4->sin_port;
2939		slen = sizeof(struct sockaddr_in);
2940		sfamily = AF_INET;
2941		cifs_dbg(FYI, "%s: connecting to %pI4:%d\n", __func__, &ipv4->sin_addr,
2942				ntohs(sport));
2943	}
2944
2945	if (socket == NULL) {
2946		rc = __sock_create(cifs_net_ns(server), sfamily, SOCK_STREAM,
2947				   IPPROTO_TCP, &socket, 1);
2948		if (rc < 0) {
2949			cifs_server_dbg(VFS, "Error %d creating socket\n", rc);
2950			server->ssocket = NULL;
2951			return rc;
2952		}
2953
2954		/* BB other socket options to set KEEPALIVE, NODELAY? */
2955		cifs_dbg(FYI, "Socket created\n");
2956		server->ssocket = socket;
2957		socket->sk->sk_allocation = GFP_NOFS;
2958		socket->sk->sk_use_task_frag = false;
2959		if (sfamily == AF_INET6)
2960			cifs_reclassify_socket6(socket);
2961		else
2962			cifs_reclassify_socket4(socket);
2963	}
2964
2965	rc = bind_socket(server);
2966	if (rc < 0)
2967		return rc;
2968
2969	/*
2970	 * Eventually check for other socket options to change from
2971	 * the default. sock_setsockopt not used because it expects
2972	 * user space buffer
2973	 */
2974	socket->sk->sk_rcvtimeo = 7 * HZ;
2975	socket->sk->sk_sndtimeo = 5 * HZ;
2976
2977	/* make the bufsizes depend on wsize/rsize and max requests */
2978	if (server->noautotune) {
2979		if (socket->sk->sk_sndbuf < (200 * 1024))
2980			socket->sk->sk_sndbuf = 200 * 1024;
2981		if (socket->sk->sk_rcvbuf < (140 * 1024))
2982			socket->sk->sk_rcvbuf = 140 * 1024;
2983	}
2984
2985	if (server->tcp_nodelay)
2986		tcp_sock_set_nodelay(socket->sk);
2987
2988	cifs_dbg(FYI, "sndbuf %d rcvbuf %d rcvtimeo 0x%lx\n",
2989		 socket->sk->sk_sndbuf,
2990		 socket->sk->sk_rcvbuf, socket->sk->sk_rcvtimeo);
2991
2992	rc = socket->ops->connect(socket, saddr, slen,
2993				  server->noblockcnt ? O_NONBLOCK : 0);
2994	/*
2995	 * When mounting SMB root file systems, we do not want to block in
2996	 * connect. Otherwise bail out and then let cifs_reconnect() perform
2997	 * reconnect failover - if possible.
2998	 */
2999	if (server->noblockcnt && rc == -EINPROGRESS)
3000		rc = 0;
3001	if (rc < 0) {
3002		cifs_dbg(FYI, "Error %d connecting to server\n", rc);
3003		trace_smb3_connect_err(server->hostname, server->conn_id, &server->dstaddr, rc);
3004		sock_release(socket);
3005		server->ssocket = NULL;
3006		return rc;
3007	}
3008	trace_smb3_connect_done(server->hostname, server->conn_id, &server->dstaddr);
3009	if (sport == htons(RFC1001_PORT))
3010		rc = ip_rfc1001_connect(server);
3011
3012	return rc;
3013}
3014
3015static int
3016ip_connect(struct TCP_Server_Info *server)
3017{
3018	__be16 *sport;
3019	struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&server->dstaddr;
3020	struct sockaddr_in *addr = (struct sockaddr_in *)&server->dstaddr;
3021
3022	if (server->dstaddr.ss_family == AF_INET6)
3023		sport = &addr6->sin6_port;
3024	else
3025		sport = &addr->sin_port;
3026
3027	if (*sport == 0) {
3028		int rc;
3029
3030		/* try with 445 port at first */
3031		*sport = htons(CIFS_PORT);
3032
3033		rc = generic_ip_connect(server);
3034		if (rc >= 0)
3035			return rc;
3036
3037		/* if it failed, try with 139 port */
3038		*sport = htons(RFC1001_PORT);
3039	}
3040
3041	return generic_ip_connect(server);
3042}
3043
3044#ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
3045void reset_cifs_unix_caps(unsigned int xid, struct cifs_tcon *tcon,
3046			  struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
3047{
3048	/*
3049	 * If we are reconnecting then should we check to see if
3050	 * any requested capabilities changed locally e.g. via
3051	 * remount but we can not do much about it here
3052	 * if they have (even if we could detect it by the following)
3053	 * Perhaps we could add a backpointer to array of sb from tcon
3054	 * or if we change to make all sb to same share the same
3055	 * sb as NFS - then we only have one backpointer to sb.
3056	 * What if we wanted to mount the server share twice once with
3057	 * and once without posixacls or posix paths?
3058	 */
3059	__u64 saved_cap = le64_to_cpu(tcon->fsUnixInfo.Capability);
3060
3061	if (ctx && ctx->no_linux_ext) {
3062		tcon->fsUnixInfo.Capability = 0;
3063		tcon->unix_ext = 0; /* Unix Extensions disabled */
3064		cifs_dbg(FYI, "Linux protocol extensions disabled\n");
3065		return;
3066	} else if (ctx)
3067		tcon->unix_ext = 1; /* Unix Extensions supported */
3068
3069	if (!tcon->unix_ext) {
3070		cifs_dbg(FYI, "Unix extensions disabled so not set on reconnect\n");
3071		return;
3072	}
3073
3074	if (!CIFSSMBQFSUnixInfo(xid, tcon)) {
3075		__u64 cap = le64_to_cpu(tcon->fsUnixInfo.Capability);
3076		cifs_dbg(FYI, "unix caps which server supports %lld\n", cap);
3077		/*
3078		 * check for reconnect case in which we do not
3079		 * want to change the mount behavior if we can avoid it
3080		 */
3081		if (ctx == NULL) {
3082			/*
3083			 * turn off POSIX ACL and PATHNAMES if not set
3084			 * originally at mount time
3085			 */
3086			if ((saved_cap & CIFS_UNIX_POSIX_ACL_CAP) == 0)
3087				cap &= ~CIFS_UNIX_POSIX_ACL_CAP;
3088			if ((saved_cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) == 0) {
3089				if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP)
3090					cifs_dbg(VFS, "POSIXPATH support change\n");
3091				cap &= ~CIFS_UNIX_POSIX_PATHNAMES_CAP;
3092			} else if ((cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) == 0) {
3093				cifs_dbg(VFS, "possible reconnect error\n");
3094				cifs_dbg(VFS, "server disabled POSIX path support\n");
3095			}
3096		}
3097
3098		if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)
3099			cifs_dbg(VFS, "per-share encryption not supported yet\n");
3100
3101		cap &= CIFS_UNIX_CAP_MASK;
3102		if (ctx && ctx->no_psx_acl)
3103			cap &= ~CIFS_UNIX_POSIX_ACL_CAP;
3104		else if (CIFS_UNIX_POSIX_ACL_CAP & cap) {
3105			cifs_dbg(FYI, "negotiated posix acl support\n");
3106			if (cifs_sb)
3107				cifs_sb->mnt_cifs_flags |=
3108					CIFS_MOUNT_POSIXACL;
3109		}
3110
3111		if (ctx && ctx->posix_paths == 0)
3112			cap &= ~CIFS_UNIX_POSIX_PATHNAMES_CAP;
3113		else if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) {
3114			cifs_dbg(FYI, "negotiate posix pathnames\n");
3115			if (cifs_sb)
3116				cifs_sb->mnt_cifs_flags |=
3117					CIFS_MOUNT_POSIX_PATHS;
3118		}
3119
3120		cifs_dbg(FYI, "Negotiate caps 0x%x\n", (int)cap);
3121#ifdef CONFIG_CIFS_DEBUG2
3122		if (cap & CIFS_UNIX_FCNTL_CAP)
3123			cifs_dbg(FYI, "FCNTL cap\n");
3124		if (cap & CIFS_UNIX_EXTATTR_CAP)
3125			cifs_dbg(FYI, "EXTATTR cap\n");
3126		if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP)
3127			cifs_dbg(FYI, "POSIX path cap\n");
3128		if (cap & CIFS_UNIX_XATTR_CAP)
3129			cifs_dbg(FYI, "XATTR cap\n");
3130		if (cap & CIFS_UNIX_POSIX_ACL_CAP)
3131			cifs_dbg(FYI, "POSIX ACL cap\n");
3132		if (cap & CIFS_UNIX_LARGE_READ_CAP)
3133			cifs_dbg(FYI, "very large read cap\n");
3134		if (cap & CIFS_UNIX_LARGE_WRITE_CAP)
3135			cifs_dbg(FYI, "very large write cap\n");
3136		if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_CAP)
3137			cifs_dbg(FYI, "transport encryption cap\n");
3138		if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)
3139			cifs_dbg(FYI, "mandatory transport encryption cap\n");
3140#endif /* CIFS_DEBUG2 */
3141		if (CIFSSMBSetFSUnixInfo(xid, tcon, cap)) {
3142			if (ctx == NULL)
3143				cifs_dbg(FYI, "resetting capabilities failed\n");
3144			else
3145				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");
3146
3147		}
3148	}
3149}
3150#endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
3151
3152int cifs_setup_cifs_sb(struct cifs_sb_info *cifs_sb)
3153{
3154	struct smb3_fs_context *ctx = cifs_sb->ctx;
3155
3156	INIT_DELAYED_WORK(&cifs_sb->prune_tlinks, cifs_prune_tlinks);
3157
3158	spin_lock_init(&cifs_sb->tlink_tree_lock);
3159	cifs_sb->tlink_tree = RB_ROOT;
3160
3161	cifs_dbg(FYI, "file mode: %04ho  dir mode: %04ho\n",
3162		 ctx->file_mode, ctx->dir_mode);
3163
3164	/* this is needed for ASCII cp to Unicode converts */
3165	if (ctx->iocharset == NULL) {
3166		/* load_nls_default cannot return null */
3167		cifs_sb->local_nls = load_nls_default();
3168	} else {
3169		cifs_sb->local_nls = load_nls(ctx->iocharset);
3170		if (cifs_sb->local_nls == NULL) {
3171			cifs_dbg(VFS, "CIFS mount error: iocharset %s not found\n",
3172				 ctx->iocharset);
3173			return -ELIBACC;
3174		}
3175	}
3176	ctx->local_nls = cifs_sb->local_nls;
3177
3178	smb3_update_mnt_flags(cifs_sb);
3179
3180	if (ctx->direct_io)
3181		cifs_dbg(FYI, "mounting share using direct i/o\n");
3182	if (ctx->cache_ro) {
3183		cifs_dbg(VFS, "mounting share with read only caching. Ensure that the share will not be modified while in use.\n");
3184		cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_RO_CACHE;
3185	} else if (ctx->cache_rw) {
3186		cifs_dbg(VFS, "mounting share in single client RW caching mode. Ensure that no other systems will be accessing the share.\n");
3187		cifs_sb->mnt_cifs_flags |= (CIFS_MOUNT_RO_CACHE |
3188					    CIFS_MOUNT_RW_CACHE);
3189	}
3190
3191	if ((ctx->cifs_acl) && (ctx->dynperm))
3192		cifs_dbg(VFS, "mount option dynperm ignored if cifsacl mount option supported\n");
3193
3194	if (ctx->prepath) {
3195		cifs_sb->prepath = kstrdup(ctx->prepath, GFP_KERNEL);
3196		if (cifs_sb->prepath == NULL)
3197			return -ENOMEM;
3198		cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
3199	}
3200
3201	return 0;
3202}
3203
3204/* Release all succeed connections */
3205void cifs_mount_put_conns(struct cifs_mount_ctx *mnt_ctx)
3206{
3207	int rc = 0;
3208
3209	if (mnt_ctx->tcon)
3210		cifs_put_tcon(mnt_ctx->tcon);
3211	else if (mnt_ctx->ses)
3212		cifs_put_smb_ses(mnt_ctx->ses);
3213	else if (mnt_ctx->server)
3214		cifs_put_tcp_session(mnt_ctx->server, 0);
3215	mnt_ctx->cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_POSIX_PATHS;
3216	free_xid(mnt_ctx->xid);
3217}
3218
3219int cifs_mount_get_session(struct cifs_mount_ctx *mnt_ctx)
3220{
3221	struct TCP_Server_Info *server = NULL;
3222	struct smb3_fs_context *ctx;
3223	struct cifs_ses *ses = NULL;
3224	unsigned int xid;
3225	int rc = 0;
3226
3227	xid = get_xid();
3228
3229	if (WARN_ON_ONCE(!mnt_ctx || !mnt_ctx->fs_ctx)) {
3230		rc = -EINVAL;
3231		goto out;
3232	}
3233	ctx = mnt_ctx->fs_ctx;
3234
3235	/* get a reference to a tcp session */
3236	server = cifs_get_tcp_session(ctx, NULL);
3237	if (IS_ERR(server)) {
3238		rc = PTR_ERR(server);
3239		server = NULL;
3240		goto out;
3241	}
3242
3243	/* get a reference to a SMB session */
3244	ses = cifs_get_smb_ses(server, ctx);
3245	if (IS_ERR(ses)) {
3246		rc = PTR_ERR(ses);
3247		ses = NULL;
3248		goto out;
3249	}
3250
3251	if ((ctx->persistent == true) && (!(ses->server->capabilities &
3252					    SMB2_GLOBAL_CAP_PERSISTENT_HANDLES))) {
3253		cifs_server_dbg(VFS, "persistent handles not supported by server\n");
3254		rc = -EOPNOTSUPP;
3255	}
3256
3257out:
3258	mnt_ctx->xid = xid;
3259	mnt_ctx->server = server;
3260	mnt_ctx->ses = ses;
3261	mnt_ctx->tcon = NULL;
3262
3263	return rc;
3264}
3265
3266int cifs_mount_get_tcon(struct cifs_mount_ctx *mnt_ctx)
3267{
3268	struct TCP_Server_Info *server;
3269	struct cifs_sb_info *cifs_sb;
3270	struct smb3_fs_context *ctx;
3271	struct cifs_tcon *tcon = NULL;
3272	int rc = 0;
3273
3274	if (WARN_ON_ONCE(!mnt_ctx || !mnt_ctx->server || !mnt_ctx->ses || !mnt_ctx->fs_ctx ||
3275			 !mnt_ctx->cifs_sb)) {
3276		rc = -EINVAL;
3277		goto out;
3278	}
3279	server = mnt_ctx->server;
3280	ctx = mnt_ctx->fs_ctx;
3281	cifs_sb = mnt_ctx->cifs_sb;
3282
3283	/* search for existing tcon to this server share */
3284	tcon = cifs_get_tcon(mnt_ctx->ses, ctx);
3285	if (IS_ERR(tcon)) {
3286		rc = PTR_ERR(tcon);
3287		tcon = NULL;
3288		goto out;
3289	}
3290
3291	/* if new SMB3.11 POSIX extensions are supported do not remap / and \ */
3292	if (tcon->posix_extensions)
3293		cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_POSIX_PATHS;
3294
3295#ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
3296	/* tell server which Unix caps we support */
3297	if (cap_unix(tcon->ses)) {
3298		/*
3299		 * reset of caps checks mount to see if unix extensions disabled
3300		 * for just this mount.
3301		 */
3302		reset_cifs_unix_caps(mnt_ctx->xid, tcon, cifs_sb, ctx);
3303		spin_lock(&tcon->ses->server->srv_lock);
3304		if ((tcon->ses->server->tcpStatus == CifsNeedReconnect) &&
3305		    (le64_to_cpu(tcon->fsUnixInfo.Capability) &
3306		     CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)) {
3307			spin_unlock(&tcon->ses->server->srv_lock);
3308			rc = -EACCES;
3309			goto out;
3310		}
3311		spin_unlock(&tcon->ses->server->srv_lock);
3312	} else
3313#endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
3314		tcon->unix_ext = 0; /* server does not support them */
3315
3316	/* do not care if a following call succeed - informational */
3317	if (!tcon->pipe && server->ops->qfs_tcon) {
3318		server->ops->qfs_tcon(mnt_ctx->xid, tcon, cifs_sb);
3319		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RO_CACHE) {
3320			if (tcon->fsDevInfo.DeviceCharacteristics &
3321			    cpu_to_le32(FILE_READ_ONLY_DEVICE))
3322				cifs_dbg(VFS, "mounted to read only share\n");
3323			else if ((cifs_sb->mnt_cifs_flags &
3324				  CIFS_MOUNT_RW_CACHE) == 0)
3325				cifs_dbg(VFS, "read only mount of RW share\n");
3326			/* no need to log a RW mount of a typical RW share */
3327		}
3328	}
3329
3330	/*
3331	 * Clamp the rsize/wsize mount arguments if they are too big for the server
3332	 * and set the rsize/wsize to the negotiated values if not passed in by
3333	 * the user on mount
3334	 */
3335	if ((cifs_sb->ctx->wsize == 0) ||
3336	    (cifs_sb->ctx->wsize > server->ops->negotiate_wsize(tcon, ctx)))
3337		cifs_sb->ctx->wsize = server->ops->negotiate_wsize(tcon, ctx);
3338	if ((cifs_sb->ctx->rsize == 0) ||
3339	    (cifs_sb->ctx->rsize > server->ops->negotiate_rsize(tcon, ctx)))
3340		cifs_sb->ctx->rsize = server->ops->negotiate_rsize(tcon, ctx);
3341
3342	/*
3343	 * The cookie is initialized from volume info returned above.
3344	 * Inside cifs_fscache_get_super_cookie it checks
3345	 * that we do not get super cookie twice.
3346	 */
3347	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_FSCACHE)
3348		cifs_fscache_get_super_cookie(tcon);
3349
3350out:
3351	mnt_ctx->tcon = tcon;
3352	return rc;
3353}
3354
3355static int mount_setup_tlink(struct cifs_sb_info *cifs_sb, struct cifs_ses *ses,
3356			     struct cifs_tcon *tcon)
3357{
3358	struct tcon_link *tlink;
3359
3360	/* hang the tcon off of the superblock */
3361	tlink = kzalloc(sizeof(*tlink), GFP_KERNEL);
3362	if (tlink == NULL)
3363		return -ENOMEM;
3364
3365	tlink->tl_uid = ses->linux_uid;
3366	tlink->tl_tcon = tcon;
3367	tlink->tl_time = jiffies;
3368	set_bit(TCON_LINK_MASTER, &tlink->tl_flags);
3369	set_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
3370
3371	cifs_sb->master_tlink = tlink;
3372	spin_lock(&cifs_sb->tlink_tree_lock);
3373	tlink_rb_insert(&cifs_sb->tlink_tree, tlink);
3374	spin_unlock(&cifs_sb->tlink_tree_lock);
3375
3376	queue_delayed_work(cifsiod_wq, &cifs_sb->prune_tlinks,
3377				TLINK_IDLE_EXPIRE);
3378	return 0;
3379}
3380
3381static int
3382cifs_are_all_path_components_accessible(struct TCP_Server_Info *server,
3383					unsigned int xid,
3384					struct cifs_tcon *tcon,
3385					struct cifs_sb_info *cifs_sb,
3386					char *full_path,
3387					int added_treename)
3388{
3389	int rc;
3390	char *s;
3391	char sep, tmp;
3392	int skip = added_treename ? 1 : 0;
3393
3394	sep = CIFS_DIR_SEP(cifs_sb);
3395	s = full_path;
3396
3397	rc = server->ops->is_path_accessible(xid, tcon, cifs_sb, "");
3398	while (rc == 0) {
3399		/* skip separators */
3400		while (*s == sep)
3401			s++;
3402		if (!*s)
3403			break;
3404		/* next separator */
3405		while (*s && *s != sep)
3406			s++;
3407		/*
3408		 * if the treename is added, we then have to skip the first
3409		 * part within the separators
3410		 */
3411		if (skip) {
3412			skip = 0;
3413			continue;
3414		}
3415		/*
3416		 * temporarily null-terminate the path at the end of
3417		 * the current component
3418		 */
3419		tmp = *s;
3420		*s = 0;
3421		rc = server->ops->is_path_accessible(xid, tcon, cifs_sb,
3422						     full_path);
3423		*s = tmp;
3424	}
3425	return rc;
3426}
3427
3428/*
3429 * Check if path is remote (i.e. a DFS share).
3430 *
3431 * Return -EREMOTE if it is, otherwise 0 or -errno.
3432 */
3433int cifs_is_path_remote(struct cifs_mount_ctx *mnt_ctx)
3434{
3435	int rc;
3436	struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3437	struct TCP_Server_Info *server = mnt_ctx->server;
3438	unsigned int xid = mnt_ctx->xid;
3439	struct cifs_tcon *tcon = mnt_ctx->tcon;
3440	struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
3441	char *full_path;
3442
3443	if (!server->ops->is_path_accessible)
3444		return -EOPNOTSUPP;
3445
3446	/*
3447	 * cifs_build_path_to_root works only when we have a valid tcon
3448	 */
3449	full_path = cifs_build_path_to_root(ctx, cifs_sb, tcon,
3450					    tcon->Flags & SMB_SHARE_IS_IN_DFS);
3451	if (full_path == NULL)
3452		return -ENOMEM;
3453
3454	cifs_dbg(FYI, "%s: full_path: %s\n", __func__, full_path);
3455
3456	rc = server->ops->is_path_accessible(xid, tcon, cifs_sb,
3457					     full_path);
3458	if (rc != 0 && rc != -EREMOTE)
3459		goto out;
3460
3461	if (rc != -EREMOTE) {
3462		rc = cifs_are_all_path_components_accessible(server, xid, tcon,
3463			cifs_sb, full_path, tcon->Flags & SMB_SHARE_IS_IN_DFS);
3464		if (rc != 0) {
3465			cifs_server_dbg(VFS, "cannot query dirs between root and final path, enabling CIFS_MOUNT_USE_PREFIX_PATH\n");
3466			cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
3467			rc = 0;
3468		}
3469	}
3470
3471out:
3472	kfree(full_path);
3473	return rc;
3474}
3475
3476#ifdef CONFIG_CIFS_DFS_UPCALL
3477int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
3478{
3479	struct cifs_mount_ctx mnt_ctx = { .cifs_sb = cifs_sb, .fs_ctx = ctx, };
3480	bool isdfs;
3481	int rc;
3482
3483	uuid_gen(&mnt_ctx.mount_id);
3484	rc = dfs_mount_share(&mnt_ctx, &isdfs);
3485	if (rc)
3486		goto error;
3487	if (!isdfs)
3488		goto out;
3489
3490	/*
3491	 * After reconnecting to a different server, unique ids won't match anymore, so we disable
3492	 * serverino. This prevents dentry revalidation to think the dentry are stale (ESTALE).
3493	 */
3494	cifs_autodisable_serverino(cifs_sb);
3495	/*
3496	 * Force the use of prefix path to support failover on DFS paths that resolve to targets
3497	 * that have different prefix paths.
3498	 */
3499	cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
3500	kfree(cifs_sb->prepath);
3501	cifs_sb->prepath = ctx->prepath;
3502	ctx->prepath = NULL;
3503	uuid_copy(&cifs_sb->dfs_mount_id, &mnt_ctx.mount_id);
3504
3505out:
3506	cifs_try_adding_channels(cifs_sb, mnt_ctx.ses);
3507	rc = mount_setup_tlink(cifs_sb, mnt_ctx.ses, mnt_ctx.tcon);
3508	if (rc)
3509		goto error;
3510
3511	free_xid(mnt_ctx.xid);
3512	return rc;
3513
3514error:
3515	dfs_cache_put_refsrv_sessions(&mnt_ctx.mount_id);
3516	kfree(mnt_ctx.origin_fullpath);
3517	kfree(mnt_ctx.leaf_fullpath);
3518	cifs_mount_put_conns(&mnt_ctx);
3519	return rc;
3520}
3521#else
3522int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
3523{
3524	int rc = 0;
3525	struct cifs_mount_ctx mnt_ctx = { .cifs_sb = cifs_sb, .fs_ctx = ctx, };
3526
3527	rc = cifs_mount_get_session(&mnt_ctx);
3528	if (rc)
3529		goto error;
3530
3531	rc = cifs_mount_get_tcon(&mnt_ctx);
3532	if (rc)
3533		goto error;
3534
3535	rc = cifs_is_path_remote(&mnt_ctx);
3536	if (rc == -EREMOTE)
3537		rc = -EOPNOTSUPP;
3538	if (rc)
3539		goto error;
3540
3541	rc = mount_setup_tlink(cifs_sb, mnt_ctx.ses, mnt_ctx.tcon);
3542	if (rc)
3543		goto error;
3544
3545	free_xid(mnt_ctx.xid);
3546	return rc;
3547
3548error:
3549	cifs_mount_put_conns(&mnt_ctx);
3550	return rc;
3551}
3552#endif
3553
3554/*
3555 * Issue a TREE_CONNECT request.
3556 */
3557int
3558CIFSTCon(const unsigned int xid, struct cifs_ses *ses,
3559	 const char *tree, struct cifs_tcon *tcon,
3560	 const struct nls_table *nls_codepage)
3561{
3562	struct smb_hdr *smb_buffer;
3563	struct smb_hdr *smb_buffer_response;
3564	TCONX_REQ *pSMB;
3565	TCONX_RSP *pSMBr;
3566	unsigned char *bcc_ptr;
3567	int rc = 0;
3568	int length;
3569	__u16 bytes_left, count;
3570
3571	if (ses == NULL)
3572		return -EIO;
3573
3574	smb_buffer = cifs_buf_get();
3575	if (smb_buffer == NULL)
3576		return -ENOMEM;
3577
3578	smb_buffer_response = smb_buffer;
3579
3580	header_assemble(smb_buffer, SMB_COM_TREE_CONNECT_ANDX,
3581			NULL /*no tid */ , 4 /*wct */ );
3582
3583	smb_buffer->Mid = get_next_mid(ses->server);
3584	smb_buffer->Uid = ses->Suid;
3585	pSMB = (TCONX_REQ *) smb_buffer;
3586	pSMBr = (TCONX_RSP *) smb_buffer_response;
3587
3588	pSMB->AndXCommand = 0xFF;
3589	pSMB->Flags = cpu_to_le16(TCON_EXTENDED_SECINFO);
3590	bcc_ptr = &pSMB->Password[0];
3591
3592	pSMB->PasswordLength = cpu_to_le16(1);	/* minimum */
3593	*bcc_ptr = 0; /* password is null byte */
3594	bcc_ptr++;              /* skip password */
3595	/* already aligned so no need to do it below */
3596
3597	if (ses->server->sign)
3598		smb_buffer->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
3599
3600	if (ses->capabilities & CAP_STATUS32) {
3601		smb_buffer->Flags2 |= SMBFLG2_ERR_STATUS;
3602	}
3603	if (ses->capabilities & CAP_DFS) {
3604		smb_buffer->Flags2 |= SMBFLG2_DFS;
3605	}
3606	if (ses->capabilities & CAP_UNICODE) {
3607		smb_buffer->Flags2 |= SMBFLG2_UNICODE;
3608		length =
3609		    cifs_strtoUTF16((__le16 *) bcc_ptr, tree,
3610			6 /* max utf8 char length in bytes */ *
3611			(/* server len*/ + 256 /* share len */), nls_codepage);
3612		bcc_ptr += 2 * length;	/* convert num 16 bit words to bytes */
3613		bcc_ptr += 2;	/* skip trailing null */
3614	} else {		/* ASCII */
3615		strcpy(bcc_ptr, tree);
3616		bcc_ptr += strlen(tree) + 1;
3617	}
3618	strcpy(bcc_ptr, "?????");
3619	bcc_ptr += strlen("?????");
3620	bcc_ptr += 1;
3621	count = bcc_ptr - &pSMB->Password[0];
3622	be32_add_cpu(&pSMB->hdr.smb_buf_length, count);
3623	pSMB->ByteCount = cpu_to_le16(count);
3624
3625	rc = SendReceive(xid, ses, smb_buffer, smb_buffer_response, &length,
3626			 0);
3627
3628	/* above now done in SendReceive */
3629	if (rc == 0) {
3630		bool is_unicode;
3631
3632		tcon->tid = smb_buffer_response->Tid;
3633		bcc_ptr = pByteArea(smb_buffer_response);
3634		bytes_left = get_bcc(smb_buffer_response);
3635		length = strnlen(bcc_ptr, bytes_left - 2);
3636		if (smb_buffer->Flags2 & SMBFLG2_UNICODE)
3637			is_unicode = true;
3638		else
3639			is_unicode = false;
3640
3641
3642		/* skip service field (NB: this field is always ASCII) */
3643		if (length == 3) {
3644			if ((bcc_ptr[0] == 'I') && (bcc_ptr[1] == 'P') &&
3645			    (bcc_ptr[2] == 'C')) {
3646				cifs_dbg(FYI, "IPC connection\n");
3647				tcon->ipc = true;
3648				tcon->pipe = true;
3649			}
3650		} else if (length == 2) {
3651			if ((bcc_ptr[0] == 'A') && (bcc_ptr[1] == ':')) {
3652				/* the most common case */
3653				cifs_dbg(FYI, "disk share connection\n");
3654			}
3655		}
3656		bcc_ptr += length + 1;
3657		bytes_left -= (length + 1);
3658		strscpy(tcon->tree_name, tree, sizeof(tcon->tree_name));
3659
3660		/* mostly informational -- no need to fail on error here */
3661		kfree(tcon->nativeFileSystem);
3662		tcon->nativeFileSystem = cifs_strndup_from_utf16(bcc_ptr,
3663						      bytes_left, is_unicode,
3664						      nls_codepage);
3665
3666		cifs_dbg(FYI, "nativeFileSystem=%s\n", tcon->nativeFileSystem);
3667
3668		if ((smb_buffer_response->WordCount == 3) ||
3669			 (smb_buffer_response->WordCount == 7))
3670			/* field is in same location */
3671			tcon->Flags = le16_to_cpu(pSMBr->OptionalSupport);
3672		else
3673			tcon->Flags = 0;
3674		cifs_dbg(FYI, "Tcon flags: 0x%x\n", tcon->Flags);
3675	}
3676
3677	cifs_buf_release(smb_buffer);
3678	return rc;
3679}
3680
3681static void delayed_free(struct rcu_head *p)
3682{
3683	struct cifs_sb_info *cifs_sb = container_of(p, struct cifs_sb_info, rcu);
3684
3685	unload_nls(cifs_sb->local_nls);
3686	smb3_cleanup_fs_context(cifs_sb->ctx);
3687	kfree(cifs_sb);
3688}
3689
3690void
3691cifs_umount(struct cifs_sb_info *cifs_sb)
3692{
3693	struct rb_root *root = &cifs_sb->tlink_tree;
3694	struct rb_node *node;
3695	struct tcon_link *tlink;
3696
3697	cancel_delayed_work_sync(&cifs_sb->prune_tlinks);
3698
3699	spin_lock(&cifs_sb->tlink_tree_lock);
3700	while ((node = rb_first(root))) {
3701		tlink = rb_entry(node, struct tcon_link, tl_rbnode);
3702		cifs_get_tlink(tlink);
3703		clear_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
3704		rb_erase(node, root);
3705
3706		spin_unlock(&cifs_sb->tlink_tree_lock);
3707		cifs_put_tlink(tlink);
3708		spin_lock(&cifs_sb->tlink_tree_lock);
3709	}
3710	spin_unlock(&cifs_sb->tlink_tree_lock);
3711
3712	kfree(cifs_sb->prepath);
3713#ifdef CONFIG_CIFS_DFS_UPCALL
3714	dfs_cache_put_refsrv_sessions(&cifs_sb->dfs_mount_id);
3715#endif
3716	call_rcu(&cifs_sb->rcu, delayed_free);
3717}
3718
3719int
3720cifs_negotiate_protocol(const unsigned int xid, struct cifs_ses *ses,
3721			struct TCP_Server_Info *server)
3722{
3723	int rc = 0;
3724
3725	if (!server->ops->need_neg || !server->ops->negotiate)
3726		return -ENOSYS;
3727
3728	/* only send once per connect */
3729	spin_lock(&server->srv_lock);
3730	if (!server->ops->need_neg(server) ||
3731	    server->tcpStatus != CifsNeedNegotiate) {
3732		spin_unlock(&server->srv_lock);
3733		return 0;
3734	}
3735	server->tcpStatus = CifsInNegotiate;
3736	spin_unlock(&server->srv_lock);
3737
3738	rc = server->ops->negotiate(xid, ses, server);
3739	if (rc == 0) {
3740		spin_lock(&server->srv_lock);
3741		if (server->tcpStatus == CifsInNegotiate)
3742			server->tcpStatus = CifsGood;
3743		else
3744			rc = -EHOSTDOWN;
3745		spin_unlock(&server->srv_lock);
3746	} else {
3747		spin_lock(&server->srv_lock);
3748		if (server->tcpStatus == CifsInNegotiate)
3749			server->tcpStatus = CifsNeedNegotiate;
3750		spin_unlock(&server->srv_lock);
3751	}
3752
3753	return rc;
3754}
3755
3756int
3757cifs_setup_session(const unsigned int xid, struct cifs_ses *ses,
3758		   struct TCP_Server_Info *server,
3759		   struct nls_table *nls_info)
3760{
3761	int rc = -ENOSYS;
3762	struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&server->dstaddr;
3763	struct sockaddr_in *addr = (struct sockaddr_in *)&server->dstaddr;
3764	bool is_binding = false;
3765
3766	spin_lock(&ses->ses_lock);
3767	if (server->dstaddr.ss_family == AF_INET6)
3768		scnprintf(ses->ip_addr, sizeof(ses->ip_addr), "%pI6", &addr6->sin6_addr);
3769	else
3770		scnprintf(ses->ip_addr, sizeof(ses->ip_addr), "%pI4", &addr->sin_addr);
3771
3772	if (ses->ses_status != SES_GOOD &&
3773	    ses->ses_status != SES_NEW &&
3774	    ses->ses_status != SES_NEED_RECON) {
3775		spin_unlock(&ses->ses_lock);
3776		return 0;
3777	}
3778
3779	/* only send once per connect */
3780	spin_lock(&ses->chan_lock);
3781	if (CIFS_ALL_CHANS_GOOD(ses) ||
3782	    cifs_chan_in_reconnect(ses, server)) {
3783		spin_unlock(&ses->chan_lock);
3784		spin_unlock(&ses->ses_lock);
3785		return 0;
3786	}
3787	is_binding = !CIFS_ALL_CHANS_NEED_RECONNECT(ses);
3788	cifs_chan_set_in_reconnect(ses, server);
3789	spin_unlock(&ses->chan_lock);
3790
3791	if (!is_binding)
3792		ses->ses_status = SES_IN_SETUP;
3793	spin_unlock(&ses->ses_lock);
3794
3795	if (!is_binding) {
3796		ses->capabilities = server->capabilities;
3797		if (!linuxExtEnabled)
3798			ses->capabilities &= (~server->vals->cap_unix);
3799
3800		if (ses->auth_key.response) {
3801			cifs_dbg(FYI, "Free previous auth_key.response = %p\n",
3802				 ses->auth_key.response);
3803			kfree_sensitive(ses->auth_key.response);
3804			ses->auth_key.response = NULL;
3805			ses->auth_key.len = 0;
3806		}
3807	}
3808
3809	cifs_dbg(FYI, "Security Mode: 0x%x Capabilities: 0x%x TimeAdjust: %d\n",
3810		 server->sec_mode, server->capabilities, server->timeAdj);
3811
3812	if (server->ops->sess_setup)
3813		rc = server->ops->sess_setup(xid, ses, server, nls_info);
3814
3815	if (rc) {
3816		cifs_server_dbg(VFS, "Send error in SessSetup = %d\n", rc);
3817		spin_lock(&ses->ses_lock);
3818		if (ses->ses_status == SES_IN_SETUP)
3819			ses->ses_status = SES_NEED_RECON;
3820		spin_lock(&ses->chan_lock);
3821		cifs_chan_clear_in_reconnect(ses, server);
3822		spin_unlock(&ses->chan_lock);
3823		spin_unlock(&ses->ses_lock);
3824	} else {
3825		spin_lock(&ses->ses_lock);
3826		if (ses->ses_status == SES_IN_SETUP)
3827			ses->ses_status = SES_GOOD;
3828		spin_lock(&ses->chan_lock);
3829		cifs_chan_clear_in_reconnect(ses, server);
3830		cifs_chan_clear_need_reconnect(ses, server);
3831		spin_unlock(&ses->chan_lock);
3832		spin_unlock(&ses->ses_lock);
3833	}
3834
3835	return rc;
3836}
3837
3838static int
3839cifs_set_vol_auth(struct smb3_fs_context *ctx, struct cifs_ses *ses)
3840{
3841	ctx->sectype = ses->sectype;
3842
3843	/* krb5 is special, since we don't need username or pw */
3844	if (ctx->sectype == Kerberos)
3845		return 0;
3846
3847	return cifs_set_cifscreds(ctx, ses);
3848}
3849
3850static struct cifs_tcon *
3851cifs_construct_tcon(struct cifs_sb_info *cifs_sb, kuid_t fsuid)
3852{
3853	int rc;
3854	struct cifs_tcon *master_tcon = cifs_sb_master_tcon(cifs_sb);
3855	struct cifs_ses *ses;
3856	struct cifs_tcon *tcon = NULL;
3857	struct smb3_fs_context *ctx;
3858
3859	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
3860	if (ctx == NULL)
3861		return ERR_PTR(-ENOMEM);
3862
3863	ctx->local_nls = cifs_sb->local_nls;
3864	ctx->linux_uid = fsuid;
3865	ctx->cred_uid = fsuid;
3866	ctx->UNC = master_tcon->tree_name;
3867	ctx->retry = master_tcon->retry;
3868	ctx->nocase = master_tcon->nocase;
3869	ctx->nohandlecache = master_tcon->nohandlecache;
3870	ctx->local_lease = master_tcon->local_lease;
3871	ctx->no_lease = master_tcon->no_lease;
3872	ctx->resilient = master_tcon->use_resilient;
3873	ctx->persistent = master_tcon->use_persistent;
3874	ctx->handle_timeout = master_tcon->handle_timeout;
3875	ctx->no_linux_ext = !master_tcon->unix_ext;
3876	ctx->linux_ext = master_tcon->posix_extensions;
3877	ctx->sectype = master_tcon->ses->sectype;
3878	ctx->sign = master_tcon->ses->sign;
3879	ctx->seal = master_tcon->seal;
3880	ctx->witness = master_tcon->use_witness;
3881
3882	rc = cifs_set_vol_auth(ctx, master_tcon->ses);
3883	if (rc) {
3884		tcon = ERR_PTR(rc);
3885		goto out;
3886	}
3887
3888	/* get a reference for the same TCP session */
3889	spin_lock(&cifs_tcp_ses_lock);
3890	++master_tcon->ses->server->srv_count;
3891	spin_unlock(&cifs_tcp_ses_lock);
3892
3893	ses = cifs_get_smb_ses(master_tcon->ses->server, ctx);
3894	if (IS_ERR(ses)) {
3895		tcon = (struct cifs_tcon *)ses;
3896		cifs_put_tcp_session(master_tcon->ses->server, 0);
3897		goto out;
3898	}
3899
3900	tcon = cifs_get_tcon(ses, ctx);
3901	if (IS_ERR(tcon)) {
3902		cifs_put_smb_ses(ses);
3903		goto out;
3904	}
3905
3906#ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
3907	if (cap_unix(ses))
3908		reset_cifs_unix_caps(0, tcon, NULL, ctx);
3909#endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
3910
3911out:
3912	kfree(ctx->username);
3913	kfree_sensitive(ctx->password);
3914	kfree(ctx);
3915
3916	return tcon;
3917}
3918
3919struct cifs_tcon *
3920cifs_sb_master_tcon(struct cifs_sb_info *cifs_sb)
3921{
3922	return tlink_tcon(cifs_sb_master_tlink(cifs_sb));
3923}
3924
3925/* find and return a tlink with given uid */
3926static struct tcon_link *
3927tlink_rb_search(struct rb_root *root, kuid_t uid)
3928{
3929	struct rb_node *node = root->rb_node;
3930	struct tcon_link *tlink;
3931
3932	while (node) {
3933		tlink = rb_entry(node, struct tcon_link, tl_rbnode);
3934
3935		if (uid_gt(tlink->tl_uid, uid))
3936			node = node->rb_left;
3937		else if (uid_lt(tlink->tl_uid, uid))
3938			node = node->rb_right;
3939		else
3940			return tlink;
3941	}
3942	return NULL;
3943}
3944
3945/* insert a tcon_link into the tree */
3946static void
3947tlink_rb_insert(struct rb_root *root, struct tcon_link *new_tlink)
3948{
3949	struct rb_node **new = &(root->rb_node), *parent = NULL;
3950	struct tcon_link *tlink;
3951
3952	while (*new) {
3953		tlink = rb_entry(*new, struct tcon_link, tl_rbnode);
3954		parent = *new;
3955
3956		if (uid_gt(tlink->tl_uid, new_tlink->tl_uid))
3957			new = &((*new)->rb_left);
3958		else
3959			new = &((*new)->rb_right);
3960	}
3961
3962	rb_link_node(&new_tlink->tl_rbnode, parent, new);
3963	rb_insert_color(&new_tlink->tl_rbnode, root);
3964}
3965
3966/*
3967 * Find or construct an appropriate tcon given a cifs_sb and the fsuid of the
3968 * current task.
3969 *
3970 * If the superblock doesn't refer to a multiuser mount, then just return
3971 * the master tcon for the mount.
3972 *
3973 * First, search the rbtree for an existing tcon for this fsuid. If one
3974 * exists, then check to see if it's pending construction. If it is then wait
3975 * for construction to complete. Once it's no longer pending, check to see if
3976 * it failed and either return an error or retry construction, depending on
3977 * the timeout.
3978 *
3979 * If one doesn't exist then insert a new tcon_link struct into the tree and
3980 * try to construct a new one.
3981 */
3982struct tcon_link *
3983cifs_sb_tlink(struct cifs_sb_info *cifs_sb)
3984{
3985	int ret;
3986	kuid_t fsuid = current_fsuid();
3987	struct tcon_link *tlink, *newtlink;
3988
3989	if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER))
3990		return cifs_get_tlink(cifs_sb_master_tlink(cifs_sb));
3991
3992	spin_lock(&cifs_sb->tlink_tree_lock);
3993	tlink = tlink_rb_search(&cifs_sb->tlink_tree, fsuid);
3994	if (tlink)
3995		cifs_get_tlink(tlink);
3996	spin_unlock(&cifs_sb->tlink_tree_lock);
3997
3998	if (tlink == NULL) {
3999		newtlink = kzalloc(sizeof(*tlink), GFP_KERNEL);
4000		if (newtlink == NULL)
4001			return ERR_PTR(-ENOMEM);
4002		newtlink->tl_uid = fsuid;
4003		newtlink->tl_tcon = ERR_PTR(-EACCES);
4004		set_bit(TCON_LINK_PENDING, &newtlink->tl_flags);
4005		set_bit(TCON_LINK_IN_TREE, &newtlink->tl_flags);
4006		cifs_get_tlink(newtlink);
4007
4008		spin_lock(&cifs_sb->tlink_tree_lock);
4009		/* was one inserted after previous search? */
4010		tlink = tlink_rb_search(&cifs_sb->tlink_tree, fsuid);
4011		if (tlink) {
4012			cifs_get_tlink(tlink);
4013			spin_unlock(&cifs_sb->tlink_tree_lock);
4014			kfree(newtlink);
4015			goto wait_for_construction;
4016		}
4017		tlink = newtlink;
4018		tlink_rb_insert(&cifs_sb->tlink_tree, tlink);
4019		spin_unlock(&cifs_sb->tlink_tree_lock);
4020	} else {
4021wait_for_construction:
4022		ret = wait_on_bit(&tlink->tl_flags, TCON_LINK_PENDING,
4023				  TASK_INTERRUPTIBLE);
4024		if (ret) {
4025			cifs_put_tlink(tlink);
4026			return ERR_PTR(-ERESTARTSYS);
4027		}
4028
4029		/* if it's good, return it */
4030		if (!IS_ERR(tlink->tl_tcon))
4031			return tlink;
4032
4033		/* return error if we tried this already recently */
4034		if (time_before(jiffies, tlink->tl_time + TLINK_ERROR_EXPIRE)) {
4035			cifs_put_tlink(tlink);
4036			return ERR_PTR(-EACCES);
4037		}
4038
4039		if (test_and_set_bit(TCON_LINK_PENDING, &tlink->tl_flags))
4040			goto wait_for_construction;
4041	}
4042
4043	tlink->tl_tcon = cifs_construct_tcon(cifs_sb, fsuid);
4044	clear_bit(TCON_LINK_PENDING, &tlink->tl_flags);
4045	wake_up_bit(&tlink->tl_flags, TCON_LINK_PENDING);
4046
4047	if (IS_ERR(tlink->tl_tcon)) {
4048		cifs_put_tlink(tlink);
4049		return ERR_PTR(-EACCES);
4050	}
4051
4052	return tlink;
4053}
4054
4055/*
4056 * periodic workqueue job that scans tcon_tree for a superblock and closes
4057 * out tcons.
4058 */
4059static void
4060cifs_prune_tlinks(struct work_struct *work)
4061{
4062	struct cifs_sb_info *cifs_sb = container_of(work, struct cifs_sb_info,
4063						    prune_tlinks.work);
4064	struct rb_root *root = &cifs_sb->tlink_tree;
4065	struct rb_node *node;
4066	struct rb_node *tmp;
4067	struct tcon_link *tlink;
4068
4069	/*
4070	 * Because we drop the spinlock in the loop in order to put the tlink
4071	 * it's not guarded against removal of links from the tree. The only
4072	 * places that remove entries from the tree are this function and
4073	 * umounts. Because this function is non-reentrant and is canceled
4074	 * before umount can proceed, this is safe.
4075	 */
4076	spin_lock(&cifs_sb->tlink_tree_lock);
4077	node = rb_first(root);
4078	while (node != NULL) {
4079		tmp = node;
4080		node = rb_next(tmp);
4081		tlink = rb_entry(tmp, struct tcon_link, tl_rbnode);
4082
4083		if (test_bit(TCON_LINK_MASTER, &tlink->tl_flags) ||
4084		    atomic_read(&tlink->tl_count) != 0 ||
4085		    time_after(tlink->tl_time + TLINK_IDLE_EXPIRE, jiffies))
4086			continue;
4087
4088		cifs_get_tlink(tlink);
4089		clear_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
4090		rb_erase(tmp, root);
4091
4092		spin_unlock(&cifs_sb->tlink_tree_lock);
4093		cifs_put_tlink(tlink);
4094		spin_lock(&cifs_sb->tlink_tree_lock);
4095	}
4096	spin_unlock(&cifs_sb->tlink_tree_lock);
4097
4098	queue_delayed_work(cifsiod_wq, &cifs_sb->prune_tlinks,
4099				TLINK_IDLE_EXPIRE);
4100}
4101
4102#ifndef CONFIG_CIFS_DFS_UPCALL
4103int cifs_tree_connect(const unsigned int xid, struct cifs_tcon *tcon, const struct nls_table *nlsc)
4104{
4105	int rc;
4106	const struct smb_version_operations *ops = tcon->ses->server->ops;
4107
4108	/* only send once per connect */
4109	spin_lock(&tcon->tc_lock);
4110	if (tcon->ses->ses_status != SES_GOOD ||
4111	    (tcon->status != TID_NEW &&
4112	    tcon->status != TID_NEED_TCON)) {
4113		spin_unlock(&tcon->tc_lock);
4114		return 0;
4115	}
4116	tcon->status = TID_IN_TCON;
4117	spin_unlock(&tcon->tc_lock);
4118
4119	rc = ops->tree_connect(xid, tcon->ses, tcon->tree_name, tcon, nlsc);
4120	if (rc) {
4121		spin_lock(&tcon->tc_lock);
4122		if (tcon->status == TID_IN_TCON)
4123			tcon->status = TID_NEED_TCON;
4124		spin_unlock(&tcon->tc_lock);
4125	} else {
4126		spin_lock(&tcon->tc_lock);
4127		if (tcon->status == TID_IN_TCON)
4128			tcon->status = TID_GOOD;
4129		tcon->need_reconnect = false;
4130		spin_unlock(&tcon->tc_lock);
4131	}
4132
4133	return rc;
4134}
4135#endif
v6.2
   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
  55extern mempool_t *cifs_req_poolp;
  56extern 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 NUM_STATUS_IO_TIMEOUT   5
  64
  65static int ip_connect(struct TCP_Server_Info *server);
  66static int generic_ip_connect(struct TCP_Server_Info *server);
  67static void tlink_rb_insert(struct rb_root *root, struct tcon_link *new_tlink);
  68static 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 */
  76static 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	time64_t expiry, now;
  83	unsigned long ttl = SMB_DNS_RESOLVE_INTERVAL_DEFAULT;
  84
  85	if (!server->hostname)
  86		return -EINVAL;
  87
  88	/* if server hostname isn't populated, there's nothing to do here */
  89	if (server->hostname[0] == '\0')
  90		return 0;
  91
  92	len = strlen(server->hostname) + 3;
  93
  94	unc = kmalloc(len, GFP_KERNEL);
  95	if (!unc) {
  96		cifs_dbg(FYI, "%s: failed to create UNC path\n", __func__);
  97		return -ENOMEM;
  98	}
  99	scnprintf(unc, len, "\\\\%s", server->hostname);
 100
 101	spin_lock(&server->srv_lock);
 102	ss = server->dstaddr;
 103	spin_unlock(&server->srv_lock);
 104
 105	rc = dns_resolve_server_name_to_ip(unc, (struct sockaddr *)&ss, &expiry);
 106	kfree(unc);
 107
 108	if (rc < 0) {
 109		cifs_dbg(FYI, "%s: failed to resolve server part of %s to IP: %d\n",
 110			 __func__, server->hostname, rc);
 111		goto requeue_resolve;
 112	}
 113
 114	spin_lock(&server->srv_lock);
 115	memcpy(&server->dstaddr, &ss, sizeof(server->dstaddr));
 116	spin_unlock(&server->srv_lock);
 117
 118	now = ktime_get_real_seconds();
 119	if (expiry && expiry > now)
 120		/* To make sure we don't use the cached entry, retry 1s */
 121		ttl = max_t(unsigned long, expiry - now, SMB_DNS_RESOLVE_INTERVAL_MIN) + 1;
 122
 123requeue_resolve:
 124	cifs_dbg(FYI, "%s: next dns resolution scheduled for %lu seconds in the future\n",
 125		 __func__, ttl);
 126	mod_delayed_work(cifsiod_wq, &server->resolve, (ttl * HZ));
 127
 128	return rc;
 129}
 130
 131static void smb2_query_server_interfaces(struct work_struct *work)
 132{
 133	int rc;
 134	struct cifs_tcon *tcon = container_of(work,
 135					struct cifs_tcon,
 136					query_interfaces.work);
 137
 138	/*
 139	 * query server network interfaces, in case they change
 140	 */
 141	rc = SMB3_request_interfaces(0, tcon, false);
 142	if (rc) {
 143		cifs_dbg(FYI, "%s: failed to query server interfaces: %d\n",
 144				__func__, rc);
 145	}
 146
 147	queue_delayed_work(cifsiod_wq, &tcon->query_interfaces,
 148			   (SMB_INTERFACE_POLL_INTERVAL * HZ));
 149}
 150
 151static void cifs_resolve_server(struct work_struct *work)
 152{
 153	int rc;
 154	struct TCP_Server_Info *server = container_of(work,
 155					struct TCP_Server_Info, resolve.work);
 156
 157	cifs_server_lock(server);
 158
 159	/*
 160	 * Resolve the hostname again to make sure that IP address is up-to-date.
 161	 */
 162	rc = reconn_set_ipaddr_from_hostname(server);
 163	if (rc) {
 164		cifs_dbg(FYI, "%s: failed to resolve hostname: %d\n",
 165				__func__, rc);
 166	}
 167
 168	cifs_server_unlock(server);
 169}
 170
 171/*
 172 * Update the tcpStatus for the server.
 173 * This is used to signal the cifsd thread to call cifs_reconnect
 174 * ONLY cifsd thread should call cifs_reconnect. For any other
 175 * thread, use this function
 176 *
 177 * @server: the tcp ses for which reconnect is needed
 178 * @all_channels: if this needs to be done for all channels
 179 */
 180void
 181cifs_signal_cifsd_for_reconnect(struct TCP_Server_Info *server,
 182				bool all_channels)
 183{
 184	struct TCP_Server_Info *pserver;
 185	struct cifs_ses *ses;
 186	int i;
 187
 188	/* If server is a channel, select the primary channel */
 189	pserver = CIFS_SERVER_IS_CHAN(server) ? server->primary_server : server;
 190
 191	spin_lock(&pserver->srv_lock);
 192	if (!all_channels) {
 193		pserver->tcpStatus = CifsNeedReconnect;
 194		spin_unlock(&pserver->srv_lock);
 195		return;
 196	}
 197	spin_unlock(&pserver->srv_lock);
 198
 199	spin_lock(&cifs_tcp_ses_lock);
 200	list_for_each_entry(ses, &pserver->smb_ses_list, smb_ses_list) {
 201		spin_lock(&ses->chan_lock);
 202		for (i = 0; i < ses->chan_count; i++) {
 203			spin_lock(&ses->chans[i].server->srv_lock);
 204			ses->chans[i].server->tcpStatus = CifsNeedReconnect;
 205			spin_unlock(&ses->chans[i].server->srv_lock);
 206		}
 207		spin_unlock(&ses->chan_lock);
 208	}
 209	spin_unlock(&cifs_tcp_ses_lock);
 210}
 211
 212/*
 213 * Mark all sessions and tcons for reconnect.
 214 * IMPORTANT: make sure that this gets called only from
 215 * cifsd thread. For any other thread, use
 216 * cifs_signal_cifsd_for_reconnect
 217 *
 218 * @server: the tcp ses for which reconnect is needed
 219 * @server needs to be previously set to CifsNeedReconnect.
 220 * @mark_smb_session: whether even sessions need to be marked
 221 */
 222void
 223cifs_mark_tcp_ses_conns_for_reconnect(struct TCP_Server_Info *server,
 224				      bool mark_smb_session)
 225{
 226	struct TCP_Server_Info *pserver;
 227	struct cifs_ses *ses, *nses;
 228	struct cifs_tcon *tcon;
 229
 230	/*
 231	 * before reconnecting the tcp session, mark the smb session (uid) and the tid bad so they
 232	 * are not used until reconnected.
 233	 */
 234	cifs_dbg(FYI, "%s: marking necessary sessions and tcons for reconnect\n", __func__);
 235
 236	/* If server is a channel, select the primary channel */
 237	pserver = CIFS_SERVER_IS_CHAN(server) ? server->primary_server : server;
 238
 239
 240	spin_lock(&cifs_tcp_ses_lock);
 241	list_for_each_entry_safe(ses, nses, &pserver->smb_ses_list, smb_ses_list) {
 242		/* check if iface is still active */
 243		if (!cifs_chan_is_iface_active(ses, server))
 244			cifs_chan_update_iface(ses, server);
 245
 246		spin_lock(&ses->chan_lock);
 247		if (!mark_smb_session && cifs_chan_needs_reconnect(ses, server))
 248			goto next_session;
 249
 250		if (mark_smb_session)
 251			CIFS_SET_ALL_CHANS_NEED_RECONNECT(ses);
 252		else
 253			cifs_chan_set_need_reconnect(ses, server);
 254
 255		/* If all channels need reconnect, then tcon needs reconnect */
 256		if (!mark_smb_session && !CIFS_ALL_CHANS_NEED_RECONNECT(ses))
 257			goto next_session;
 258
 259		ses->ses_status = SES_NEED_RECON;
 260
 261		list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
 262			tcon->need_reconnect = true;
 263			tcon->status = TID_NEED_RECON;
 264		}
 265		if (ses->tcon_ipc) {
 266			ses->tcon_ipc->need_reconnect = true;
 267			ses->tcon_ipc->status = TID_NEED_RECON;
 268		}
 269
 270next_session:
 271		spin_unlock(&ses->chan_lock);
 272	}
 273	spin_unlock(&cifs_tcp_ses_lock);
 274}
 275
 276static void
 277cifs_abort_connection(struct TCP_Server_Info *server)
 278{
 279	struct mid_q_entry *mid, *nmid;
 280	struct list_head retry_list;
 281
 282	server->maxBuf = 0;
 283	server->max_read = 0;
 284
 285	/* do not want to be sending data on a socket we are freeing */
 286	cifs_dbg(FYI, "%s: tearing down socket\n", __func__);
 287	cifs_server_lock(server);
 288	if (server->ssocket) {
 289		cifs_dbg(FYI, "State: 0x%x Flags: 0x%lx\n", server->ssocket->state,
 290			 server->ssocket->flags);
 291		kernel_sock_shutdown(server->ssocket, SHUT_WR);
 292		cifs_dbg(FYI, "Post shutdown state: 0x%x Flags: 0x%lx\n", server->ssocket->state,
 293			 server->ssocket->flags);
 294		sock_release(server->ssocket);
 295		server->ssocket = NULL;
 296	}
 297	server->sequence_number = 0;
 298	server->session_estab = false;
 299	kfree_sensitive(server->session_key.response);
 300	server->session_key.response = NULL;
 301	server->session_key.len = 0;
 302	server->lstrp = jiffies;
 303
 304	/* mark submitted MIDs for retry and issue callback */
 305	INIT_LIST_HEAD(&retry_list);
 306	cifs_dbg(FYI, "%s: moving mids to private list\n", __func__);
 307	spin_lock(&server->mid_lock);
 308	list_for_each_entry_safe(mid, nmid, &server->pending_mid_q, qhead) {
 309		kref_get(&mid->refcount);
 310		if (mid->mid_state == MID_REQUEST_SUBMITTED)
 311			mid->mid_state = MID_RETRY_NEEDED;
 312		list_move(&mid->qhead, &retry_list);
 313		mid->mid_flags |= MID_DELETED;
 314	}
 315	spin_unlock(&server->mid_lock);
 316	cifs_server_unlock(server);
 317
 318	cifs_dbg(FYI, "%s: issuing mid callbacks\n", __func__);
 319	list_for_each_entry_safe(mid, nmid, &retry_list, qhead) {
 320		list_del_init(&mid->qhead);
 321		mid->callback(mid);
 322		release_mid(mid);
 323	}
 324
 325	if (cifs_rdma_enabled(server)) {
 326		cifs_server_lock(server);
 327		smbd_destroy(server);
 328		cifs_server_unlock(server);
 329	}
 330}
 331
 332static bool cifs_tcp_ses_needs_reconnect(struct TCP_Server_Info *server, int num_targets)
 333{
 334	spin_lock(&server->srv_lock);
 335	server->nr_targets = num_targets;
 336	if (server->tcpStatus == CifsExiting) {
 337		/* the demux thread will exit normally next time through the loop */
 338		spin_unlock(&server->srv_lock);
 339		wake_up(&server->response_q);
 340		return false;
 341	}
 342
 343	cifs_dbg(FYI, "Mark tcp session as need reconnect\n");
 344	trace_smb3_reconnect(server->CurrentMid, server->conn_id,
 345			     server->hostname);
 346	server->tcpStatus = CifsNeedReconnect;
 347
 348	spin_unlock(&server->srv_lock);
 349	return true;
 350}
 351
 352/*
 353 * cifs tcp session reconnection
 354 *
 355 * mark tcp session as reconnecting so temporarily locked
 356 * mark all smb sessions as reconnecting for tcp session
 357 * reconnect tcp session
 358 * wake up waiters on reconnection? - (not needed currently)
 359 *
 360 * if mark_smb_session is passed as true, unconditionally mark
 361 * the smb session (and tcon) for reconnect as well. This value
 362 * doesn't really matter for non-multichannel scenario.
 363 *
 364 */
 365static int __cifs_reconnect(struct TCP_Server_Info *server,
 366			    bool mark_smb_session)
 367{
 368	int rc = 0;
 369
 370	if (!cifs_tcp_ses_needs_reconnect(server, 1))
 371		return 0;
 372
 373	cifs_mark_tcp_ses_conns_for_reconnect(server, mark_smb_session);
 374
 375	cifs_abort_connection(server);
 376
 377	do {
 378		try_to_freeze();
 379		cifs_server_lock(server);
 380
 381		if (!cifs_swn_set_server_dstaddr(server)) {
 382			/* resolve the hostname again to make sure that IP address is up-to-date */
 383			rc = reconn_set_ipaddr_from_hostname(server);
 384			cifs_dbg(FYI, "%s: reconn_set_ipaddr_from_hostname: rc=%d\n", __func__, rc);
 385		}
 386
 387		if (cifs_rdma_enabled(server))
 388			rc = smbd_reconnect(server);
 389		else
 390			rc = generic_ip_connect(server);
 391		if (rc) {
 392			cifs_server_unlock(server);
 393			cifs_dbg(FYI, "%s: reconnect error %d\n", __func__, rc);
 394			msleep(3000);
 395		} else {
 396			atomic_inc(&tcpSesReconnectCount);
 397			set_credits(server, 1);
 398			spin_lock(&server->srv_lock);
 399			if (server->tcpStatus != CifsExiting)
 400				server->tcpStatus = CifsNeedNegotiate;
 401			spin_unlock(&server->srv_lock);
 402			cifs_swn_reset_server_dstaddr(server);
 403			cifs_server_unlock(server);
 404			mod_delayed_work(cifsiod_wq, &server->reconnect, 0);
 405		}
 406	} while (server->tcpStatus == CifsNeedReconnect);
 407
 408	spin_lock(&server->srv_lock);
 409	if (server->tcpStatus == CifsNeedNegotiate)
 410		mod_delayed_work(cifsiod_wq, &server->echo, 0);
 411	spin_unlock(&server->srv_lock);
 412
 413	wake_up(&server->response_q);
 414	return rc;
 415}
 416
 417#ifdef CONFIG_CIFS_DFS_UPCALL
 418static int __reconnect_target_unlocked(struct TCP_Server_Info *server, const char *target)
 419{
 420	int rc;
 421	char *hostname;
 422
 423	if (!cifs_swn_set_server_dstaddr(server)) {
 424		if (server->hostname != target) {
 425			hostname = extract_hostname(target);
 426			if (!IS_ERR(hostname)) {
 427				kfree(server->hostname);
 428				server->hostname = hostname;
 429			} else {
 430				cifs_dbg(FYI, "%s: couldn't extract hostname or address from dfs target: %ld\n",
 431					 __func__, PTR_ERR(hostname));
 432				cifs_dbg(FYI, "%s: default to last target server: %s\n", __func__,
 433					 server->hostname);
 434			}
 435		}
 436		/* resolve the hostname again to make sure that IP address is up-to-date. */
 437		rc = reconn_set_ipaddr_from_hostname(server);
 438		cifs_dbg(FYI, "%s: reconn_set_ipaddr_from_hostname: rc=%d\n", __func__, rc);
 439	}
 440	/* Reconnect the socket */
 441	if (cifs_rdma_enabled(server))
 442		rc = smbd_reconnect(server);
 443	else
 444		rc = generic_ip_connect(server);
 445
 446	return rc;
 447}
 448
 449static int reconnect_target_unlocked(struct TCP_Server_Info *server, struct dfs_cache_tgt_list *tl,
 450				     struct dfs_cache_tgt_iterator **target_hint)
 451{
 452	int rc;
 453	struct dfs_cache_tgt_iterator *tit;
 454
 455	*target_hint = NULL;
 456
 457	/* If dfs target list is empty, then reconnect to last server */
 458	tit = dfs_cache_get_tgt_iterator(tl);
 459	if (!tit)
 460		return __reconnect_target_unlocked(server, server->hostname);
 461
 462	/* Otherwise, try every dfs target in @tl */
 463	for (; tit; tit = dfs_cache_get_next_tgt(tl, tit)) {
 464		rc = __reconnect_target_unlocked(server, dfs_cache_get_tgt_name(tit));
 465		if (!rc) {
 466			*target_hint = tit;
 467			break;
 468		}
 469	}
 470	return rc;
 471}
 472
 473static int reconnect_dfs_server(struct TCP_Server_Info *server)
 474{
 475	int rc = 0;
 476	const char *refpath = server->current_fullpath + 1;
 477	struct dfs_cache_tgt_list tl = DFS_CACHE_TGT_LIST_INIT(tl);
 478	struct dfs_cache_tgt_iterator *target_hint = NULL;
 479	int num_targets = 0;
 480
 481	/*
 482	 * Determine the number of dfs targets the referral path in @cifs_sb resolves to.
 483	 *
 484	 * smb2_reconnect() needs to know how long it should wait based upon the number of dfs
 485	 * targets (server->nr_targets).  It's also possible that the cached referral was cleared
 486	 * through /proc/fs/cifs/dfscache or the target list is empty due to server settings after
 487	 * refreshing the referral, so, in this case, default it to 1.
 488	 */
 489	if (!dfs_cache_noreq_find(refpath, NULL, &tl))
 490		num_targets = dfs_cache_get_nr_tgts(&tl);
 491	if (!num_targets)
 492		num_targets = 1;
 493
 494	if (!cifs_tcp_ses_needs_reconnect(server, num_targets))
 495		return 0;
 496
 497	/*
 498	 * Unconditionally mark all sessions & tcons for reconnect as we might be connecting to a
 499	 * different server or share during failover.  It could be improved by adding some logic to
 500	 * only do that in case it connects to a different server or share, though.
 501	 */
 502	cifs_mark_tcp_ses_conns_for_reconnect(server, true);
 503
 504	cifs_abort_connection(server);
 505
 506	do {
 507		try_to_freeze();
 508		cifs_server_lock(server);
 509
 510		rc = reconnect_target_unlocked(server, &tl, &target_hint);
 511		if (rc) {
 512			/* Failed to reconnect socket */
 513			cifs_server_unlock(server);
 514			cifs_dbg(FYI, "%s: reconnect error %d\n", __func__, rc);
 515			msleep(3000);
 516			continue;
 517		}
 518		/*
 519		 * Socket was created.  Update tcp session status to CifsNeedNegotiate so that a
 520		 * process waiting for reconnect will know it needs to re-establish session and tcon
 521		 * through the reconnected target server.
 522		 */
 523		atomic_inc(&tcpSesReconnectCount);
 524		set_credits(server, 1);
 525		spin_lock(&server->srv_lock);
 526		if (server->tcpStatus != CifsExiting)
 527			server->tcpStatus = CifsNeedNegotiate;
 528		spin_unlock(&server->srv_lock);
 529		cifs_swn_reset_server_dstaddr(server);
 530		cifs_server_unlock(server);
 531		mod_delayed_work(cifsiod_wq, &server->reconnect, 0);
 532	} while (server->tcpStatus == CifsNeedReconnect);
 533
 534	dfs_cache_noreq_update_tgthint(refpath, target_hint);
 535	dfs_cache_free_tgts(&tl);
 536
 537	/* Need to set up echo worker again once connection has been established */
 538	spin_lock(&server->srv_lock);
 539	if (server->tcpStatus == CifsNeedNegotiate)
 540		mod_delayed_work(cifsiod_wq, &server->echo, 0);
 541	spin_unlock(&server->srv_lock);
 542
 543	wake_up(&server->response_q);
 544	return rc;
 545}
 546
 547int cifs_reconnect(struct TCP_Server_Info *server, bool mark_smb_session)
 548{
 549	mutex_lock(&server->refpath_lock);
 550	if (!server->leaf_fullpath) {
 551		mutex_unlock(&server->refpath_lock);
 552		return __cifs_reconnect(server, mark_smb_session);
 553	}
 554	mutex_unlock(&server->refpath_lock);
 555
 556	return reconnect_dfs_server(server);
 557}
 558#else
 559int cifs_reconnect(struct TCP_Server_Info *server, bool mark_smb_session)
 560{
 561	return __cifs_reconnect(server, mark_smb_session);
 562}
 563#endif
 564
 565static void
 566cifs_echo_request(struct work_struct *work)
 567{
 568	int rc;
 569	struct TCP_Server_Info *server = container_of(work,
 570					struct TCP_Server_Info, echo.work);
 571
 572	/*
 573	 * We cannot send an echo if it is disabled.
 574	 * Also, no need to ping if we got a response recently.
 575	 */
 576
 577	if (server->tcpStatus == CifsNeedReconnect ||
 578	    server->tcpStatus == CifsExiting ||
 579	    server->tcpStatus == CifsNew ||
 580	    (server->ops->can_echo && !server->ops->can_echo(server)) ||
 581	    time_before(jiffies, server->lstrp + server->echo_interval - HZ))
 582		goto requeue_echo;
 583
 584	rc = server->ops->echo ? server->ops->echo(server) : -ENOSYS;
 585	if (rc)
 586		cifs_dbg(FYI, "Unable to send echo request to server: %s\n",
 587			 server->hostname);
 588
 589	/* Check witness registrations */
 590	cifs_swn_check();
 591
 592requeue_echo:
 593	queue_delayed_work(cifsiod_wq, &server->echo, server->echo_interval);
 594}
 595
 596static bool
 597allocate_buffers(struct TCP_Server_Info *server)
 598{
 599	if (!server->bigbuf) {
 600		server->bigbuf = (char *)cifs_buf_get();
 601		if (!server->bigbuf) {
 602			cifs_server_dbg(VFS, "No memory for large SMB response\n");
 603			msleep(3000);
 604			/* retry will check if exiting */
 605			return false;
 606		}
 607	} else if (server->large_buf) {
 608		/* we are reusing a dirty large buf, clear its start */
 609		memset(server->bigbuf, 0, HEADER_SIZE(server));
 610	}
 611
 612	if (!server->smallbuf) {
 613		server->smallbuf = (char *)cifs_small_buf_get();
 614		if (!server->smallbuf) {
 615			cifs_server_dbg(VFS, "No memory for SMB response\n");
 616			msleep(1000);
 617			/* retry will check if exiting */
 618			return false;
 619		}
 620		/* beginning of smb buffer is cleared in our buf_get */
 621	} else {
 622		/* if existing small buf clear beginning */
 623		memset(server->smallbuf, 0, HEADER_SIZE(server));
 624	}
 625
 626	return true;
 627}
 628
 629static bool
 630server_unresponsive(struct TCP_Server_Info *server)
 631{
 632	/*
 633	 * We need to wait 3 echo intervals to make sure we handle such
 634	 * situations right:
 635	 * 1s  client sends a normal SMB request
 636	 * 2s  client gets a response
 637	 * 30s echo workqueue job pops, and decides we got a response recently
 638	 *     and don't need to send another
 639	 * ...
 640	 * 65s kernel_recvmsg times out, and we see that we haven't gotten
 641	 *     a response in >60s.
 642	 */
 643	spin_lock(&server->srv_lock);
 644	if ((server->tcpStatus == CifsGood ||
 645	    server->tcpStatus == CifsNeedNegotiate) &&
 646	    (!server->ops->can_echo || server->ops->can_echo(server)) &&
 647	    time_after(jiffies, server->lstrp + 3 * server->echo_interval)) {
 648		spin_unlock(&server->srv_lock);
 649		cifs_server_dbg(VFS, "has not responded in %lu seconds. Reconnecting...\n",
 650			 (3 * server->echo_interval) / HZ);
 651		cifs_reconnect(server, false);
 652		return true;
 653	}
 654	spin_unlock(&server->srv_lock);
 655
 656	return false;
 657}
 658
 659static inline bool
 660zero_credits(struct TCP_Server_Info *server)
 661{
 662	int val;
 663
 664	spin_lock(&server->req_lock);
 665	val = server->credits + server->echo_credits + server->oplock_credits;
 666	if (server->in_flight == 0 && val == 0) {
 667		spin_unlock(&server->req_lock);
 668		return true;
 669	}
 670	spin_unlock(&server->req_lock);
 671	return false;
 672}
 673
 674static int
 675cifs_readv_from_socket(struct TCP_Server_Info *server, struct msghdr *smb_msg)
 676{
 677	int length = 0;
 678	int total_read;
 679
 680	for (total_read = 0; msg_data_left(smb_msg); total_read += length) {
 681		try_to_freeze();
 682
 683		/* reconnect if no credits and no requests in flight */
 684		if (zero_credits(server)) {
 685			cifs_reconnect(server, false);
 686			return -ECONNABORTED;
 687		}
 688
 689		if (server_unresponsive(server))
 690			return -ECONNABORTED;
 691		if (cifs_rdma_enabled(server) && server->smbd_conn)
 692			length = smbd_recv(server->smbd_conn, smb_msg);
 693		else
 694			length = sock_recvmsg(server->ssocket, smb_msg, 0);
 695
 696		spin_lock(&server->srv_lock);
 697		if (server->tcpStatus == CifsExiting) {
 698			spin_unlock(&server->srv_lock);
 699			return -ESHUTDOWN;
 700		}
 701
 702		if (server->tcpStatus == CifsNeedReconnect) {
 703			spin_unlock(&server->srv_lock);
 704			cifs_reconnect(server, false);
 705			return -ECONNABORTED;
 706		}
 707		spin_unlock(&server->srv_lock);
 708
 709		if (length == -ERESTARTSYS ||
 710		    length == -EAGAIN ||
 711		    length == -EINTR) {
 712			/*
 713			 * Minimum sleep to prevent looping, allowing socket
 714			 * to clear and app threads to set tcpStatus
 715			 * CifsNeedReconnect if server hung.
 716			 */
 717			usleep_range(1000, 2000);
 718			length = 0;
 719			continue;
 720		}
 721
 722		if (length <= 0) {
 723			cifs_dbg(FYI, "Received no data or error: %d\n", length);
 724			cifs_reconnect(server, false);
 725			return -ECONNABORTED;
 726		}
 727	}
 728	return total_read;
 729}
 730
 731int
 732cifs_read_from_socket(struct TCP_Server_Info *server, char *buf,
 733		      unsigned int to_read)
 734{
 735	struct msghdr smb_msg = {};
 736	struct kvec iov = {.iov_base = buf, .iov_len = to_read};
 737	iov_iter_kvec(&smb_msg.msg_iter, ITER_DEST, &iov, 1, to_read);
 738
 739	return cifs_readv_from_socket(server, &smb_msg);
 740}
 741
 742ssize_t
 743cifs_discard_from_socket(struct TCP_Server_Info *server, size_t to_read)
 744{
 745	struct msghdr smb_msg = {};
 746
 747	/*
 748	 *  iov_iter_discard already sets smb_msg.type and count and iov_offset
 749	 *  and cifs_readv_from_socket sets msg_control and msg_controllen
 750	 *  so little to initialize in struct msghdr
 751	 */
 752	iov_iter_discard(&smb_msg.msg_iter, ITER_DEST, to_read);
 753
 754	return cifs_readv_from_socket(server, &smb_msg);
 755}
 756
 757int
 758cifs_read_page_from_socket(struct TCP_Server_Info *server, struct page *page,
 759	unsigned int page_offset, unsigned int to_read)
 760{
 761	struct msghdr smb_msg = {};
 762	struct bio_vec bv = {
 763		.bv_page = page, .bv_len = to_read, .bv_offset = page_offset};
 764	iov_iter_bvec(&smb_msg.msg_iter, ITER_DEST, &bv, 1, to_read);
 765	return cifs_readv_from_socket(server, &smb_msg);
 766}
 767
 768static bool
 769is_smb_response(struct TCP_Server_Info *server, unsigned char type)
 770{
 771	/*
 772	 * The first byte big endian of the length field,
 773	 * is actually not part of the length but the type
 774	 * with the most common, zero, as regular data.
 775	 */
 776	switch (type) {
 777	case RFC1002_SESSION_MESSAGE:
 778		/* Regular SMB response */
 779		return true;
 780	case RFC1002_SESSION_KEEP_ALIVE:
 781		cifs_dbg(FYI, "RFC 1002 session keep alive\n");
 782		break;
 783	case RFC1002_POSITIVE_SESSION_RESPONSE:
 784		cifs_dbg(FYI, "RFC 1002 positive session response\n");
 785		break;
 786	case RFC1002_NEGATIVE_SESSION_RESPONSE:
 787		/*
 788		 * We get this from Windows 98 instead of an error on
 789		 * SMB negprot response.
 790		 */
 791		cifs_dbg(FYI, "RFC 1002 negative session response\n");
 792		/* give server a second to clean up */
 793		msleep(1000);
 794		/*
 795		 * Always try 445 first on reconnect since we get NACK
 796		 * on some if we ever connected to port 139 (the NACK
 797		 * is since we do not begin with RFC1001 session
 798		 * initialize frame).
 799		 */
 800		cifs_set_port((struct sockaddr *)&server->dstaddr, CIFS_PORT);
 801		cifs_reconnect(server, true);
 802		break;
 803	default:
 804		cifs_server_dbg(VFS, "RFC 1002 unknown response type 0x%x\n", type);
 805		cifs_reconnect(server, true);
 806	}
 807
 808	return false;
 809}
 810
 811void
 812dequeue_mid(struct mid_q_entry *mid, bool malformed)
 813{
 814#ifdef CONFIG_CIFS_STATS2
 815	mid->when_received = jiffies;
 816#endif
 817	spin_lock(&mid->server->mid_lock);
 818	if (!malformed)
 819		mid->mid_state = MID_RESPONSE_RECEIVED;
 820	else
 821		mid->mid_state = MID_RESPONSE_MALFORMED;
 822	/*
 823	 * Trying to handle/dequeue a mid after the send_recv()
 824	 * function has finished processing it is a bug.
 825	 */
 826	if (mid->mid_flags & MID_DELETED) {
 827		spin_unlock(&mid->server->mid_lock);
 828		pr_warn_once("trying to dequeue a deleted mid\n");
 829	} else {
 830		list_del_init(&mid->qhead);
 831		mid->mid_flags |= MID_DELETED;
 832		spin_unlock(&mid->server->mid_lock);
 833	}
 834}
 835
 836static unsigned int
 837smb2_get_credits_from_hdr(char *buffer, struct TCP_Server_Info *server)
 838{
 839	struct smb2_hdr *shdr = (struct smb2_hdr *)buffer;
 840
 841	/*
 842	 * SMB1 does not use credits.
 843	 */
 844	if (is_smb1(server))
 845		return 0;
 846
 847	return le16_to_cpu(shdr->CreditRequest);
 848}
 849
 850static void
 851handle_mid(struct mid_q_entry *mid, struct TCP_Server_Info *server,
 852	   char *buf, int malformed)
 853{
 854	if (server->ops->check_trans2 &&
 855	    server->ops->check_trans2(mid, server, buf, malformed))
 856		return;
 857	mid->credits_received = smb2_get_credits_from_hdr(buf, server);
 858	mid->resp_buf = buf;
 859	mid->large_buf = server->large_buf;
 860	/* Was previous buf put in mpx struct for multi-rsp? */
 861	if (!mid->multiRsp) {
 862		/* smb buffer will be freed by user thread */
 863		if (server->large_buf)
 864			server->bigbuf = NULL;
 865		else
 866			server->smallbuf = NULL;
 867	}
 868	dequeue_mid(mid, malformed);
 869}
 870
 871int
 872cifs_enable_signing(struct TCP_Server_Info *server, bool mnt_sign_required)
 873{
 874	bool srv_sign_required = server->sec_mode & server->vals->signing_required;
 875	bool srv_sign_enabled = server->sec_mode & server->vals->signing_enabled;
 876	bool mnt_sign_enabled;
 877
 878	/*
 879	 * Is signing required by mnt options? If not then check
 880	 * global_secflags to see if it is there.
 881	 */
 882	if (!mnt_sign_required)
 883		mnt_sign_required = ((global_secflags & CIFSSEC_MUST_SIGN) ==
 884						CIFSSEC_MUST_SIGN);
 885
 886	/*
 887	 * If signing is required then it's automatically enabled too,
 888	 * otherwise, check to see if the secflags allow it.
 889	 */
 890	mnt_sign_enabled = mnt_sign_required ? mnt_sign_required :
 891				(global_secflags & CIFSSEC_MAY_SIGN);
 892
 893	/* If server requires signing, does client allow it? */
 894	if (srv_sign_required) {
 895		if (!mnt_sign_enabled) {
 896			cifs_dbg(VFS, "Server requires signing, but it's disabled in SecurityFlags!\n");
 897			return -EOPNOTSUPP;
 898		}
 899		server->sign = true;
 900	}
 901
 902	/* If client requires signing, does server allow it? */
 903	if (mnt_sign_required) {
 904		if (!srv_sign_enabled) {
 905			cifs_dbg(VFS, "Server does not support signing!\n");
 906			return -EOPNOTSUPP;
 907		}
 908		server->sign = true;
 909	}
 910
 911	if (cifs_rdma_enabled(server) && server->sign)
 912		cifs_dbg(VFS, "Signing is enabled, and RDMA read/write will be disabled\n");
 913
 914	return 0;
 915}
 916
 917
 918static void clean_demultiplex_info(struct TCP_Server_Info *server)
 919{
 920	int length;
 921
 922	/* take it off the list, if it's not already */
 923	spin_lock(&server->srv_lock);
 924	list_del_init(&server->tcp_ses_list);
 925	spin_unlock(&server->srv_lock);
 926
 927	cancel_delayed_work_sync(&server->echo);
 928	cancel_delayed_work_sync(&server->resolve);
 929
 930	spin_lock(&server->srv_lock);
 931	server->tcpStatus = CifsExiting;
 932	spin_unlock(&server->srv_lock);
 933	wake_up_all(&server->response_q);
 934
 935	/* check if we have blocked requests that need to free */
 936	spin_lock(&server->req_lock);
 937	if (server->credits <= 0)
 938		server->credits = 1;
 939	spin_unlock(&server->req_lock);
 940	/*
 941	 * Although there should not be any requests blocked on this queue it
 942	 * can not hurt to be paranoid and try to wake up requests that may
 943	 * haven been blocked when more than 50 at time were on the wire to the
 944	 * same server - they now will see the session is in exit state and get
 945	 * out of SendReceive.
 946	 */
 947	wake_up_all(&server->request_q);
 948	/* give those requests time to exit */
 949	msleep(125);
 950	if (cifs_rdma_enabled(server))
 951		smbd_destroy(server);
 952	if (server->ssocket) {
 953		sock_release(server->ssocket);
 954		server->ssocket = NULL;
 955	}
 956
 957	if (!list_empty(&server->pending_mid_q)) {
 958		struct list_head dispose_list;
 959		struct mid_q_entry *mid_entry;
 960		struct list_head *tmp, *tmp2;
 961
 962		INIT_LIST_HEAD(&dispose_list);
 963		spin_lock(&server->mid_lock);
 964		list_for_each_safe(tmp, tmp2, &server->pending_mid_q) {
 965			mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
 966			cifs_dbg(FYI, "Clearing mid %llu\n", mid_entry->mid);
 967			kref_get(&mid_entry->refcount);
 968			mid_entry->mid_state = MID_SHUTDOWN;
 969			list_move(&mid_entry->qhead, &dispose_list);
 970			mid_entry->mid_flags |= MID_DELETED;
 971		}
 972		spin_unlock(&server->mid_lock);
 973
 974		/* now walk dispose list and issue callbacks */
 975		list_for_each_safe(tmp, tmp2, &dispose_list) {
 976			mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
 977			cifs_dbg(FYI, "Callback mid %llu\n", mid_entry->mid);
 978			list_del_init(&mid_entry->qhead);
 979			mid_entry->callback(mid_entry);
 980			release_mid(mid_entry);
 981		}
 982		/* 1/8th of sec is more than enough time for them to exit */
 983		msleep(125);
 984	}
 985
 986	if (!list_empty(&server->pending_mid_q)) {
 987		/*
 988		 * mpx threads have not exited yet give them at least the smb
 989		 * send timeout time for long ops.
 990		 *
 991		 * Due to delays on oplock break requests, we need to wait at
 992		 * least 45 seconds before giving up on a request getting a
 993		 * response and going ahead and killing cifsd.
 994		 */
 995		cifs_dbg(FYI, "Wait for exit from demultiplex thread\n");
 996		msleep(46000);
 997		/*
 998		 * If threads still have not exited they are probably never
 999		 * coming home not much else we can do but free the memory.
1000		 */
1001	}
1002
1003#ifdef CONFIG_CIFS_DFS_UPCALL
1004	kfree(server->origin_fullpath);
1005	kfree(server->leaf_fullpath);
1006#endif
1007	kfree(server);
1008
1009	length = atomic_dec_return(&tcpSesAllocCount);
1010	if (length > 0)
1011		mempool_resize(cifs_req_poolp, length + cifs_min_rcv);
1012}
1013
1014static int
1015standard_receive3(struct TCP_Server_Info *server, struct mid_q_entry *mid)
1016{
1017	int length;
1018	char *buf = server->smallbuf;
1019	unsigned int pdu_length = server->pdu_size;
1020
1021	/* make sure this will fit in a large buffer */
1022	if (pdu_length > CIFSMaxBufSize + MAX_HEADER_SIZE(server) -
1023	    HEADER_PREAMBLE_SIZE(server)) {
1024		cifs_server_dbg(VFS, "SMB response too long (%u bytes)\n", pdu_length);
1025		cifs_reconnect(server, true);
1026		return -ECONNABORTED;
1027	}
1028
1029	/* switch to large buffer if too big for a small one */
1030	if (pdu_length > MAX_CIFS_SMALL_BUFFER_SIZE - 4) {
1031		server->large_buf = true;
1032		memcpy(server->bigbuf, buf, server->total_read);
1033		buf = server->bigbuf;
1034	}
1035
1036	/* now read the rest */
1037	length = cifs_read_from_socket(server, buf + HEADER_SIZE(server) - 1,
1038				       pdu_length - MID_HEADER_SIZE(server));
1039
1040	if (length < 0)
1041		return length;
1042	server->total_read += length;
1043
1044	dump_smb(buf, server->total_read);
1045
1046	return cifs_handle_standard(server, mid);
1047}
1048
1049int
1050cifs_handle_standard(struct TCP_Server_Info *server, struct mid_q_entry *mid)
1051{
1052	char *buf = server->large_buf ? server->bigbuf : server->smallbuf;
1053	int rc;
1054
1055	/*
1056	 * We know that we received enough to get to the MID as we
1057	 * checked the pdu_length earlier. Now check to see
1058	 * if the rest of the header is OK.
1059	 *
1060	 * 48 bytes is enough to display the header and a little bit
1061	 * into the payload for debugging purposes.
1062	 */
1063	rc = server->ops->check_message(buf, server->total_read, server);
1064	if (rc)
1065		cifs_dump_mem("Bad SMB: ", buf,
1066			min_t(unsigned int, server->total_read, 48));
1067
1068	if (server->ops->is_session_expired &&
1069	    server->ops->is_session_expired(buf)) {
1070		cifs_reconnect(server, true);
1071		return -1;
1072	}
1073
1074	if (server->ops->is_status_pending &&
1075	    server->ops->is_status_pending(buf, server))
1076		return -1;
1077
1078	if (!mid)
1079		return rc;
1080
1081	handle_mid(mid, server, buf, rc);
1082	return 0;
1083}
1084
1085static void
1086smb2_add_credits_from_hdr(char *buffer, struct TCP_Server_Info *server)
1087{
1088	struct smb2_hdr *shdr = (struct smb2_hdr *)buffer;
1089	int scredits, in_flight;
1090
1091	/*
1092	 * SMB1 does not use credits.
1093	 */
1094	if (is_smb1(server))
1095		return;
1096
1097	if (shdr->CreditRequest) {
1098		spin_lock(&server->req_lock);
1099		server->credits += le16_to_cpu(shdr->CreditRequest);
1100		scredits = server->credits;
1101		in_flight = server->in_flight;
1102		spin_unlock(&server->req_lock);
1103		wake_up(&server->request_q);
1104
1105		trace_smb3_hdr_credits(server->CurrentMid,
1106				server->conn_id, server->hostname, scredits,
1107				le16_to_cpu(shdr->CreditRequest), in_flight);
1108		cifs_server_dbg(FYI, "%s: added %u credits total=%d\n",
1109				__func__, le16_to_cpu(shdr->CreditRequest),
1110				scredits);
1111	}
1112}
1113
1114
1115static int
1116cifs_demultiplex_thread(void *p)
1117{
1118	int i, num_mids, length;
1119	struct TCP_Server_Info *server = p;
1120	unsigned int pdu_length;
1121	unsigned int next_offset;
1122	char *buf = NULL;
1123	struct task_struct *task_to_wake = NULL;
1124	struct mid_q_entry *mids[MAX_COMPOUND];
1125	char *bufs[MAX_COMPOUND];
1126	unsigned int noreclaim_flag, num_io_timeout = 0;
1127
1128	noreclaim_flag = memalloc_noreclaim_save();
1129	cifs_dbg(FYI, "Demultiplex PID: %d\n", task_pid_nr(current));
1130
1131	length = atomic_inc_return(&tcpSesAllocCount);
1132	if (length > 1)
1133		mempool_resize(cifs_req_poolp, length + cifs_min_rcv);
1134
1135	set_freezable();
1136	allow_kernel_signal(SIGKILL);
1137	while (server->tcpStatus != CifsExiting) {
1138		if (try_to_freeze())
1139			continue;
1140
1141		if (!allocate_buffers(server))
1142			continue;
1143
1144		server->large_buf = false;
1145		buf = server->smallbuf;
1146		pdu_length = 4; /* enough to get RFC1001 header */
1147
1148		length = cifs_read_from_socket(server, buf, pdu_length);
1149		if (length < 0)
1150			continue;
1151
1152		if (is_smb1(server))
1153			server->total_read = length;
1154		else
1155			server->total_read = 0;
1156
1157		/*
1158		 * The right amount was read from socket - 4 bytes,
1159		 * so we can now interpret the length field.
1160		 */
1161		pdu_length = get_rfc1002_length(buf);
1162
1163		cifs_dbg(FYI, "RFC1002 header 0x%x\n", pdu_length);
1164		if (!is_smb_response(server, buf[0]))
1165			continue;
1166next_pdu:
1167		server->pdu_size = pdu_length;
1168
1169		/* make sure we have enough to get to the MID */
1170		if (server->pdu_size < MID_HEADER_SIZE(server)) {
1171			cifs_server_dbg(VFS, "SMB response too short (%u bytes)\n",
1172				 server->pdu_size);
1173			cifs_reconnect(server, true);
1174			continue;
1175		}
1176
1177		/* read down to the MID */
1178		length = cifs_read_from_socket(server,
1179			     buf + HEADER_PREAMBLE_SIZE(server),
1180			     MID_HEADER_SIZE(server));
1181		if (length < 0)
1182			continue;
1183		server->total_read += length;
1184
1185		if (server->ops->next_header) {
1186			next_offset = server->ops->next_header(buf);
1187			if (next_offset)
1188				server->pdu_size = next_offset;
1189		}
1190
1191		memset(mids, 0, sizeof(mids));
1192		memset(bufs, 0, sizeof(bufs));
1193		num_mids = 0;
1194
1195		if (server->ops->is_transform_hdr &&
1196		    server->ops->receive_transform &&
1197		    server->ops->is_transform_hdr(buf)) {
1198			length = server->ops->receive_transform(server,
1199								mids,
1200								bufs,
1201								&num_mids);
1202		} else {
1203			mids[0] = server->ops->find_mid(server, buf);
1204			bufs[0] = buf;
1205			num_mids = 1;
1206
1207			if (!mids[0] || !mids[0]->receive)
1208				length = standard_receive3(server, mids[0]);
1209			else
1210				length = mids[0]->receive(server, mids[0]);
1211		}
1212
1213		if (length < 0) {
1214			for (i = 0; i < num_mids; i++)
1215				if (mids[i])
1216					release_mid(mids[i]);
1217			continue;
1218		}
1219
1220		if (server->ops->is_status_io_timeout &&
1221		    server->ops->is_status_io_timeout(buf)) {
1222			num_io_timeout++;
1223			if (num_io_timeout > NUM_STATUS_IO_TIMEOUT) {
1224				cifs_reconnect(server, false);
1225				num_io_timeout = 0;
1226				continue;
1227			}
1228		}
1229
1230		server->lstrp = jiffies;
1231
1232		for (i = 0; i < num_mids; i++) {
1233			if (mids[i] != NULL) {
1234				mids[i]->resp_buf_size = server->pdu_size;
1235
1236				if (bufs[i] && server->ops->is_network_name_deleted)
1237					server->ops->is_network_name_deleted(bufs[i],
1238									server);
1239
1240				if (!mids[i]->multiRsp || mids[i]->multiEnd)
1241					mids[i]->callback(mids[i]);
1242
1243				release_mid(mids[i]);
1244			} else if (server->ops->is_oplock_break &&
1245				   server->ops->is_oplock_break(bufs[i],
1246								server)) {
1247				smb2_add_credits_from_hdr(bufs[i], server);
1248				cifs_dbg(FYI, "Received oplock break\n");
1249			} else {
1250				cifs_server_dbg(VFS, "No task to wake, unknown frame received! NumMids %d\n",
1251						atomic_read(&mid_count));
1252				cifs_dump_mem("Received Data is: ", bufs[i],
1253					      HEADER_SIZE(server));
1254				smb2_add_credits_from_hdr(bufs[i], server);
1255#ifdef CONFIG_CIFS_DEBUG2
1256				if (server->ops->dump_detail)
1257					server->ops->dump_detail(bufs[i],
1258								 server);
1259				cifs_dump_mids(server);
1260#endif /* CIFS_DEBUG2 */
1261			}
1262		}
1263
1264		if (pdu_length > server->pdu_size) {
1265			if (!allocate_buffers(server))
1266				continue;
1267			pdu_length -= server->pdu_size;
1268			server->total_read = 0;
1269			server->large_buf = false;
1270			buf = server->smallbuf;
1271			goto next_pdu;
1272		}
1273	} /* end while !EXITING */
1274
1275	/* buffer usually freed in free_mid - need to free it here on exit */
1276	cifs_buf_release(server->bigbuf);
1277	if (server->smallbuf) /* no sense logging a debug message if NULL */
1278		cifs_small_buf_release(server->smallbuf);
1279
1280	task_to_wake = xchg(&server->tsk, NULL);
1281	clean_demultiplex_info(server);
1282
1283	/* if server->tsk was NULL then wait for a signal before exiting */
1284	if (!task_to_wake) {
1285		set_current_state(TASK_INTERRUPTIBLE);
1286		while (!signal_pending(current)) {
1287			schedule();
1288			set_current_state(TASK_INTERRUPTIBLE);
1289		}
1290		set_current_state(TASK_RUNNING);
1291	}
1292
1293	memalloc_noreclaim_restore(noreclaim_flag);
1294	module_put_and_kthread_exit(0);
1295}
1296
1297/*
1298 * Returns true if srcaddr isn't specified and rhs isn't specified, or
1299 * if srcaddr is specified and matches the IP address of the rhs argument
1300 */
1301bool
1302cifs_match_ipaddr(struct sockaddr *srcaddr, struct sockaddr *rhs)
1303{
1304	switch (srcaddr->sa_family) {
1305	case AF_UNSPEC:
1306		return (rhs->sa_family == AF_UNSPEC);
1307	case AF_INET: {
1308		struct sockaddr_in *saddr4 = (struct sockaddr_in *)srcaddr;
1309		struct sockaddr_in *vaddr4 = (struct sockaddr_in *)rhs;
1310		return (saddr4->sin_addr.s_addr == vaddr4->sin_addr.s_addr);
1311	}
1312	case AF_INET6: {
1313		struct sockaddr_in6 *saddr6 = (struct sockaddr_in6 *)srcaddr;
1314		struct sockaddr_in6 *vaddr6 = (struct sockaddr_in6 *)rhs;
1315		return ipv6_addr_equal(&saddr6->sin6_addr, &vaddr6->sin6_addr);
1316	}
1317	default:
1318		WARN_ON(1);
1319		return false; /* don't expect to be here */
1320	}
1321}
1322
1323/*
1324 * If no port is specified in addr structure, we try to match with 445 port
1325 * and if it fails - with 139 ports. It should be called only if address
1326 * families of server and addr are equal.
1327 */
1328static bool
1329match_port(struct TCP_Server_Info *server, struct sockaddr *addr)
1330{
1331	__be16 port, *sport;
1332
1333	/* SMBDirect manages its own ports, don't match it here */
1334	if (server->rdma)
1335		return true;
1336
1337	switch (addr->sa_family) {
1338	case AF_INET:
1339		sport = &((struct sockaddr_in *) &server->dstaddr)->sin_port;
1340		port = ((struct sockaddr_in *) addr)->sin_port;
1341		break;
1342	case AF_INET6:
1343		sport = &((struct sockaddr_in6 *) &server->dstaddr)->sin6_port;
1344		port = ((struct sockaddr_in6 *) addr)->sin6_port;
1345		break;
1346	default:
1347		WARN_ON(1);
1348		return false;
1349	}
1350
1351	if (!port) {
1352		port = htons(CIFS_PORT);
1353		if (port == *sport)
1354			return true;
1355
1356		port = htons(RFC1001_PORT);
1357	}
1358
1359	return port == *sport;
1360}
1361
1362static bool match_server_address(struct TCP_Server_Info *server, struct sockaddr *addr)
1363{
1364	switch (addr->sa_family) {
1365	case AF_INET: {
1366		struct sockaddr_in *addr4 = (struct sockaddr_in *)addr;
1367		struct sockaddr_in *srv_addr4 =
1368					(struct sockaddr_in *)&server->dstaddr;
1369
1370		if (addr4->sin_addr.s_addr != srv_addr4->sin_addr.s_addr)
1371			return false;
1372		break;
1373	}
1374	case AF_INET6: {
1375		struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)addr;
1376		struct sockaddr_in6 *srv_addr6 =
1377					(struct sockaddr_in6 *)&server->dstaddr;
1378
1379		if (!ipv6_addr_equal(&addr6->sin6_addr,
1380				     &srv_addr6->sin6_addr))
1381			return false;
1382		if (addr6->sin6_scope_id != srv_addr6->sin6_scope_id)
1383			return false;
1384		break;
1385	}
1386	default:
1387		WARN_ON(1);
1388		return false; /* don't expect to be here */
1389	}
1390
1391	return true;
1392}
1393
1394static bool
1395match_security(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
1396{
1397	/*
1398	 * The select_sectype function should either return the ctx->sectype
1399	 * that was specified, or "Unspecified" if that sectype was not
1400	 * compatible with the given NEGOTIATE request.
1401	 */
1402	if (server->ops->select_sectype(server, ctx->sectype)
1403	     == Unspecified)
1404		return false;
1405
1406	/*
1407	 * Now check if signing mode is acceptable. No need to check
1408	 * global_secflags at this point since if MUST_SIGN is set then
1409	 * the server->sign had better be too.
1410	 */
1411	if (ctx->sign && !server->sign)
1412		return false;
1413
1414	return true;
1415}
1416
1417static bool dfs_src_pathname_equal(const char *s1, const char *s2)
1418{
1419	if (strlen(s1) != strlen(s2))
1420		return false;
1421	for (; *s1; s1++, s2++) {
1422		if (*s1 == '/' || *s1 == '\\') {
1423			if (*s2 != '/' && *s2 != '\\')
1424				return false;
1425		} else if (tolower(*s1) != tolower(*s2))
1426			return false;
1427	}
1428	return true;
1429}
1430
1431/* this function must be called with srv_lock held */
1432static int match_server(struct TCP_Server_Info *server, struct smb3_fs_context *ctx,
1433			bool dfs_super_cmp)
1434{
1435	struct sockaddr *addr = (struct sockaddr *)&ctx->dstaddr;
1436
1437	if (ctx->nosharesock)
1438		return 0;
1439
1440	/* this server does not share socket */
1441	if (server->nosharesock)
1442		return 0;
1443
1444	/* If multidialect negotiation see if existing sessions match one */
1445	if (strcmp(ctx->vals->version_string, SMB3ANY_VERSION_STRING) == 0) {
1446		if (server->vals->protocol_id < SMB30_PROT_ID)
1447			return 0;
1448	} else if (strcmp(ctx->vals->version_string,
1449		   SMBDEFAULT_VERSION_STRING) == 0) {
1450		if (server->vals->protocol_id < SMB21_PROT_ID)
1451			return 0;
1452	} else if ((server->vals != ctx->vals) || (server->ops != ctx->ops))
1453		return 0;
1454
1455	if (!net_eq(cifs_net_ns(server), current->nsproxy->net_ns))
1456		return 0;
1457
1458	if (!cifs_match_ipaddr((struct sockaddr *)&ctx->srcaddr,
1459			       (struct sockaddr *)&server->srcaddr))
1460		return 0;
1461	/*
1462	 * When matching DFS superblocks, we only check for original source pathname as the
1463	 * currently connected target might be different than the one parsed earlier in i.e.
1464	 * mount.cifs(8).
1465	 */
1466	if (dfs_super_cmp) {
1467		if (!ctx->source || !server->origin_fullpath ||
1468		    !dfs_src_pathname_equal(server->origin_fullpath, ctx->source))
1469			return 0;
1470	} else {
1471		/* Skip addr, hostname and port matching for DFS connections */
1472		if (server->leaf_fullpath) {
1473			if (!ctx->leaf_fullpath ||
1474			    strcasecmp(server->leaf_fullpath, ctx->leaf_fullpath))
1475				return 0;
1476		} else if (strcasecmp(server->hostname, ctx->server_hostname) ||
1477			   !match_server_address(server, addr) ||
1478			   !match_port(server, addr)) {
1479			return 0;
1480		}
1481	}
1482
1483	if (!match_security(server, ctx))
1484		return 0;
1485
1486	if (server->echo_interval != ctx->echo_interval * HZ)
1487		return 0;
1488
1489	if (server->rdma != ctx->rdma)
1490		return 0;
1491
1492	if (server->ignore_signature != ctx->ignore_signature)
1493		return 0;
1494
1495	if (server->min_offload != ctx->min_offload)
1496		return 0;
1497
1498	return 1;
1499}
1500
1501struct TCP_Server_Info *
1502cifs_find_tcp_session(struct smb3_fs_context *ctx)
1503{
1504	struct TCP_Server_Info *server;
1505
1506	spin_lock(&cifs_tcp_ses_lock);
1507	list_for_each_entry(server, &cifs_tcp_ses_list, tcp_ses_list) {
1508		spin_lock(&server->srv_lock);
1509		/*
1510		 * Skip ses channels since they're only handled in lower layers
1511		 * (e.g. cifs_send_recv).
1512		 */
1513		if (CIFS_SERVER_IS_CHAN(server) || !match_server(server, ctx, false)) {
1514			spin_unlock(&server->srv_lock);
1515			continue;
1516		}
1517		spin_unlock(&server->srv_lock);
1518
1519		++server->srv_count;
1520		spin_unlock(&cifs_tcp_ses_lock);
1521		cifs_dbg(FYI, "Existing tcp session with server found\n");
1522		return server;
1523	}
1524	spin_unlock(&cifs_tcp_ses_lock);
1525	return NULL;
1526}
1527
1528void
1529cifs_put_tcp_session(struct TCP_Server_Info *server, int from_reconnect)
1530{
1531	struct task_struct *task;
1532
1533	spin_lock(&cifs_tcp_ses_lock);
1534	if (--server->srv_count > 0) {
1535		spin_unlock(&cifs_tcp_ses_lock);
1536		return;
1537	}
1538
1539	/* srv_count can never go negative */
1540	WARN_ON(server->srv_count < 0);
1541
1542	put_net(cifs_net_ns(server));
1543
1544	list_del_init(&server->tcp_ses_list);
1545	spin_unlock(&cifs_tcp_ses_lock);
1546
1547	/* For secondary channels, we pick up ref-count on the primary server */
1548	if (CIFS_SERVER_IS_CHAN(server))
1549		cifs_put_tcp_session(server->primary_server, from_reconnect);
1550
1551	cancel_delayed_work_sync(&server->echo);
1552	cancel_delayed_work_sync(&server->resolve);
1553
1554	if (from_reconnect)
1555		/*
1556		 * Avoid deadlock here: reconnect work calls
1557		 * cifs_put_tcp_session() at its end. Need to be sure
1558		 * that reconnect work does nothing with server pointer after
1559		 * that step.
1560		 */
1561		cancel_delayed_work(&server->reconnect);
1562	else
1563		cancel_delayed_work_sync(&server->reconnect);
1564
1565	spin_lock(&server->srv_lock);
1566	server->tcpStatus = CifsExiting;
1567	spin_unlock(&server->srv_lock);
1568
1569	cifs_crypto_secmech_release(server);
1570
1571	kfree_sensitive(server->session_key.response);
1572	server->session_key.response = NULL;
1573	server->session_key.len = 0;
1574	kfree(server->hostname);
1575	server->hostname = NULL;
1576
1577	task = xchg(&server->tsk, NULL);
1578	if (task)
1579		send_sig(SIGKILL, task, 1);
1580}
1581
1582struct TCP_Server_Info *
1583cifs_get_tcp_session(struct smb3_fs_context *ctx,
1584		     struct TCP_Server_Info *primary_server)
1585{
1586	struct TCP_Server_Info *tcp_ses = NULL;
1587	int rc;
1588
1589	cifs_dbg(FYI, "UNC: %s\n", ctx->UNC);
1590
1591	/* see if we already have a matching tcp_ses */
1592	tcp_ses = cifs_find_tcp_session(ctx);
1593	if (tcp_ses)
1594		return tcp_ses;
1595
1596	tcp_ses = kzalloc(sizeof(struct TCP_Server_Info), GFP_KERNEL);
1597	if (!tcp_ses) {
1598		rc = -ENOMEM;
1599		goto out_err;
1600	}
1601
1602	tcp_ses->hostname = kstrdup(ctx->server_hostname, GFP_KERNEL);
1603	if (!tcp_ses->hostname) {
1604		rc = -ENOMEM;
1605		goto out_err;
1606	}
1607
1608	if (ctx->leaf_fullpath) {
1609		tcp_ses->leaf_fullpath = kstrdup(ctx->leaf_fullpath, GFP_KERNEL);
1610		if (!tcp_ses->leaf_fullpath) {
1611			rc = -ENOMEM;
1612			goto out_err;
1613		}
1614		tcp_ses->current_fullpath = tcp_ses->leaf_fullpath;
1615	}
1616
1617	if (ctx->nosharesock)
1618		tcp_ses->nosharesock = true;
1619
1620	tcp_ses->ops = ctx->ops;
1621	tcp_ses->vals = ctx->vals;
1622	cifs_set_net_ns(tcp_ses, get_net(current->nsproxy->net_ns));
1623
1624	tcp_ses->conn_id = atomic_inc_return(&tcpSesNextId);
1625	tcp_ses->noblockcnt = ctx->rootfs;
1626	tcp_ses->noblocksnd = ctx->noblocksnd || ctx->rootfs;
1627	tcp_ses->noautotune = ctx->noautotune;
1628	tcp_ses->tcp_nodelay = ctx->sockopt_tcp_nodelay;
1629	tcp_ses->rdma = ctx->rdma;
1630	tcp_ses->in_flight = 0;
1631	tcp_ses->max_in_flight = 0;
1632	tcp_ses->credits = 1;
1633	if (primary_server) {
1634		spin_lock(&cifs_tcp_ses_lock);
1635		++primary_server->srv_count;
1636		spin_unlock(&cifs_tcp_ses_lock);
1637		tcp_ses->primary_server = primary_server;
1638	}
1639	init_waitqueue_head(&tcp_ses->response_q);
1640	init_waitqueue_head(&tcp_ses->request_q);
1641	INIT_LIST_HEAD(&tcp_ses->pending_mid_q);
1642	mutex_init(&tcp_ses->_srv_mutex);
1643	memcpy(tcp_ses->workstation_RFC1001_name,
1644		ctx->source_rfc1001_name, RFC1001_NAME_LEN_WITH_NULL);
1645	memcpy(tcp_ses->server_RFC1001_name,
1646		ctx->target_rfc1001_name, RFC1001_NAME_LEN_WITH_NULL);
1647	tcp_ses->session_estab = false;
1648	tcp_ses->sequence_number = 0;
1649	tcp_ses->reconnect_instance = 1;
1650	tcp_ses->lstrp = jiffies;
1651	tcp_ses->compress_algorithm = cpu_to_le16(ctx->compression);
1652	spin_lock_init(&tcp_ses->req_lock);
1653	spin_lock_init(&tcp_ses->srv_lock);
1654	spin_lock_init(&tcp_ses->mid_lock);
1655	INIT_LIST_HEAD(&tcp_ses->tcp_ses_list);
1656	INIT_LIST_HEAD(&tcp_ses->smb_ses_list);
1657	INIT_DELAYED_WORK(&tcp_ses->echo, cifs_echo_request);
1658	INIT_DELAYED_WORK(&tcp_ses->resolve, cifs_resolve_server);
1659	INIT_DELAYED_WORK(&tcp_ses->reconnect, smb2_reconnect_server);
1660	mutex_init(&tcp_ses->reconnect_mutex);
1661#ifdef CONFIG_CIFS_DFS_UPCALL
1662	mutex_init(&tcp_ses->refpath_lock);
1663#endif
1664	memcpy(&tcp_ses->srcaddr, &ctx->srcaddr,
1665	       sizeof(tcp_ses->srcaddr));
1666	memcpy(&tcp_ses->dstaddr, &ctx->dstaddr,
1667		sizeof(tcp_ses->dstaddr));
1668	if (ctx->use_client_guid)
1669		memcpy(tcp_ses->client_guid, ctx->client_guid,
1670		       SMB2_CLIENT_GUID_SIZE);
1671	else
1672		generate_random_uuid(tcp_ses->client_guid);
1673	/*
1674	 * at this point we are the only ones with the pointer
1675	 * to the struct since the kernel thread not created yet
1676	 * no need to spinlock this init of tcpStatus or srv_count
1677	 */
1678	tcp_ses->tcpStatus = CifsNew;
1679	++tcp_ses->srv_count;
1680
1681	if (ctx->echo_interval >= SMB_ECHO_INTERVAL_MIN &&
1682		ctx->echo_interval <= SMB_ECHO_INTERVAL_MAX)
1683		tcp_ses->echo_interval = ctx->echo_interval * HZ;
1684	else
1685		tcp_ses->echo_interval = SMB_ECHO_INTERVAL_DEFAULT * HZ;
1686	if (tcp_ses->rdma) {
1687#ifndef CONFIG_CIFS_SMB_DIRECT
1688		cifs_dbg(VFS, "CONFIG_CIFS_SMB_DIRECT is not enabled\n");
1689		rc = -ENOENT;
1690		goto out_err_crypto_release;
1691#endif
1692		tcp_ses->smbd_conn = smbd_get_connection(
1693			tcp_ses, (struct sockaddr *)&ctx->dstaddr);
1694		if (tcp_ses->smbd_conn) {
1695			cifs_dbg(VFS, "RDMA transport established\n");
1696			rc = 0;
1697			goto smbd_connected;
1698		} else {
1699			rc = -ENOENT;
1700			goto out_err_crypto_release;
1701		}
1702	}
1703	rc = ip_connect(tcp_ses);
1704	if (rc < 0) {
1705		cifs_dbg(VFS, "Error connecting to socket. Aborting operation.\n");
1706		goto out_err_crypto_release;
1707	}
1708smbd_connected:
1709	/*
1710	 * since we're in a cifs function already, we know that
1711	 * this will succeed. No need for try_module_get().
1712	 */
1713	__module_get(THIS_MODULE);
1714	tcp_ses->tsk = kthread_run(cifs_demultiplex_thread,
1715				  tcp_ses, "cifsd");
1716	if (IS_ERR(tcp_ses->tsk)) {
1717		rc = PTR_ERR(tcp_ses->tsk);
1718		cifs_dbg(VFS, "error %d create cifsd thread\n", rc);
1719		module_put(THIS_MODULE);
1720		goto out_err_crypto_release;
1721	}
1722	tcp_ses->min_offload = ctx->min_offload;
1723	/*
1724	 * at this point we are the only ones with the pointer
1725	 * to the struct since the kernel thread not created yet
1726	 * no need to spinlock this update of tcpStatus
1727	 */
1728	spin_lock(&tcp_ses->srv_lock);
1729	tcp_ses->tcpStatus = CifsNeedNegotiate;
1730	spin_unlock(&tcp_ses->srv_lock);
1731
1732	if ((ctx->max_credits < 20) || (ctx->max_credits > 60000))
1733		tcp_ses->max_credits = SMB2_MAX_CREDITS_AVAILABLE;
1734	else
1735		tcp_ses->max_credits = ctx->max_credits;
1736
1737	tcp_ses->nr_targets = 1;
1738	tcp_ses->ignore_signature = ctx->ignore_signature;
1739	/* thread spawned, put it on the list */
1740	spin_lock(&cifs_tcp_ses_lock);
1741	list_add(&tcp_ses->tcp_ses_list, &cifs_tcp_ses_list);
1742	spin_unlock(&cifs_tcp_ses_lock);
1743
1744	/* queue echo request delayed work */
1745	queue_delayed_work(cifsiod_wq, &tcp_ses->echo, tcp_ses->echo_interval);
1746
1747	/* queue dns resolution delayed work */
1748	cifs_dbg(FYI, "%s: next dns resolution scheduled for %d seconds in the future\n",
1749		 __func__, SMB_DNS_RESOLVE_INTERVAL_DEFAULT);
1750
1751	queue_delayed_work(cifsiod_wq, &tcp_ses->resolve, (SMB_DNS_RESOLVE_INTERVAL_DEFAULT * HZ));
1752
1753	return tcp_ses;
1754
1755out_err_crypto_release:
1756	cifs_crypto_secmech_release(tcp_ses);
1757
1758	put_net(cifs_net_ns(tcp_ses));
1759
1760out_err:
1761	if (tcp_ses) {
1762		if (CIFS_SERVER_IS_CHAN(tcp_ses))
1763			cifs_put_tcp_session(tcp_ses->primary_server, false);
1764		kfree(tcp_ses->hostname);
1765		kfree(tcp_ses->leaf_fullpath);
1766		if (tcp_ses->ssocket)
1767			sock_release(tcp_ses->ssocket);
1768		kfree(tcp_ses);
1769	}
1770	return ERR_PTR(rc);
1771}
1772
1773/* this function must be called with ses_lock held */
1774static int match_session(struct cifs_ses *ses, struct smb3_fs_context *ctx)
1775{
1776	if (ctx->sectype != Unspecified &&
1777	    ctx->sectype != ses->sectype)
1778		return 0;
1779
1780	/*
1781	 * If an existing session is limited to less channels than
1782	 * requested, it should not be reused
1783	 */
1784	spin_lock(&ses->chan_lock);
1785	if (ses->chan_max < ctx->max_channels) {
1786		spin_unlock(&ses->chan_lock);
1787		return 0;
1788	}
1789	spin_unlock(&ses->chan_lock);
1790
1791	switch (ses->sectype) {
1792	case Kerberos:
1793		if (!uid_eq(ctx->cred_uid, ses->cred_uid))
1794			return 0;
1795		break;
1796	default:
1797		/* NULL username means anonymous session */
1798		if (ses->user_name == NULL) {
1799			if (!ctx->nullauth)
1800				return 0;
1801			break;
1802		}
1803
1804		/* anything else takes username/password */
1805		if (strncmp(ses->user_name,
1806			    ctx->username ? ctx->username : "",
1807			    CIFS_MAX_USERNAME_LEN))
1808			return 0;
1809		if ((ctx->username && strlen(ctx->username) != 0) &&
1810		    ses->password != NULL &&
1811		    strncmp(ses->password,
1812			    ctx->password ? ctx->password : "",
1813			    CIFS_MAX_PASSWORD_LEN))
1814			return 0;
1815	}
1816	return 1;
1817}
1818
1819/**
1820 * cifs_setup_ipc - helper to setup the IPC tcon for the session
1821 * @ses: smb session to issue the request on
1822 * @ctx: the superblock configuration context to use for building the
1823 *       new tree connection for the IPC (interprocess communication RPC)
1824 *
1825 * A new IPC connection is made and stored in the session
1826 * tcon_ipc. The IPC tcon has the same lifetime as the session.
1827 */
1828static int
1829cifs_setup_ipc(struct cifs_ses *ses, struct smb3_fs_context *ctx)
1830{
1831	int rc = 0, xid;
1832	struct cifs_tcon *tcon;
1833	char unc[SERVER_NAME_LENGTH + sizeof("//x/IPC$")] = {0};
1834	bool seal = false;
1835	struct TCP_Server_Info *server = ses->server;
1836
1837	/*
1838	 * If the mount request that resulted in the creation of the
1839	 * session requires encryption, force IPC to be encrypted too.
1840	 */
1841	if (ctx->seal) {
1842		if (server->capabilities & SMB2_GLOBAL_CAP_ENCRYPTION)
1843			seal = true;
1844		else {
1845			cifs_server_dbg(VFS,
1846				 "IPC: server doesn't support encryption\n");
1847			return -EOPNOTSUPP;
1848		}
1849	}
1850
1851	tcon = tconInfoAlloc();
1852	if (tcon == NULL)
1853		return -ENOMEM;
1854
1855	scnprintf(unc, sizeof(unc), "\\\\%s\\IPC$", server->hostname);
1856
1857	xid = get_xid();
1858	tcon->ses = ses;
1859	tcon->ipc = true;
1860	tcon->seal = seal;
1861	rc = server->ops->tree_connect(xid, ses, unc, tcon, ctx->local_nls);
1862	free_xid(xid);
1863
1864	if (rc) {
1865		cifs_server_dbg(VFS, "failed to connect to IPC (rc=%d)\n", rc);
1866		tconInfoFree(tcon);
1867		goto out;
1868	}
1869
1870	cifs_dbg(FYI, "IPC tcon rc=%d ipc tid=0x%x\n", rc, tcon->tid);
1871
1872	spin_lock(&tcon->tc_lock);
1873	tcon->status = TID_GOOD;
1874	spin_unlock(&tcon->tc_lock);
1875	ses->tcon_ipc = tcon;
1876out:
1877	return rc;
1878}
1879
1880/**
1881 * cifs_free_ipc - helper to release the session IPC tcon
1882 * @ses: smb session to unmount the IPC from
1883 *
1884 * Needs to be called everytime a session is destroyed.
1885 *
1886 * On session close, the IPC is closed and the server must release all tcons of the session.
1887 * No need to send a tree disconnect here.
1888 *
1889 * Besides, it will make the server to not close durable and resilient files on session close, as
1890 * specified in MS-SMB2 3.3.5.6 Receiving an SMB2 LOGOFF Request.
1891 */
1892static int
1893cifs_free_ipc(struct cifs_ses *ses)
1894{
1895	struct cifs_tcon *tcon = ses->tcon_ipc;
1896
1897	if (tcon == NULL)
1898		return 0;
1899
1900	tconInfoFree(tcon);
1901	ses->tcon_ipc = NULL;
1902	return 0;
1903}
1904
1905static struct cifs_ses *
1906cifs_find_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
1907{
1908	struct cifs_ses *ses;
1909
1910	spin_lock(&cifs_tcp_ses_lock);
1911	list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) {
1912		spin_lock(&ses->ses_lock);
1913		if (ses->ses_status == SES_EXITING) {
1914			spin_unlock(&ses->ses_lock);
1915			continue;
1916		}
1917		if (!match_session(ses, ctx)) {
1918			spin_unlock(&ses->ses_lock);
1919			continue;
1920		}
1921		spin_unlock(&ses->ses_lock);
1922
1923		++ses->ses_count;
1924		spin_unlock(&cifs_tcp_ses_lock);
1925		return ses;
1926	}
1927	spin_unlock(&cifs_tcp_ses_lock);
1928	return NULL;
1929}
1930
1931void cifs_put_smb_ses(struct cifs_ses *ses)
1932{
1933	unsigned int rc, xid;
1934	unsigned int chan_count;
1935	struct TCP_Server_Info *server = ses->server;
1936
1937	spin_lock(&ses->ses_lock);
1938	if (ses->ses_status == SES_EXITING) {
1939		spin_unlock(&ses->ses_lock);
1940		return;
1941	}
1942	spin_unlock(&ses->ses_lock);
1943
1944	cifs_dbg(FYI, "%s: ses_count=%d\n", __func__, ses->ses_count);
1945	cifs_dbg(FYI,
1946		 "%s: ses ipc: %s\n", __func__, ses->tcon_ipc ? ses->tcon_ipc->tree_name : "NONE");
1947
1948	spin_lock(&cifs_tcp_ses_lock);
1949	if (--ses->ses_count > 0) {
1950		spin_unlock(&cifs_tcp_ses_lock);
1951		return;
1952	}
1953	spin_unlock(&cifs_tcp_ses_lock);
1954
1955	/* ses_count can never go negative */
1956	WARN_ON(ses->ses_count < 0);
1957
1958	if (ses->ses_status == SES_GOOD)
1959		ses->ses_status = SES_EXITING;
1960
1961	cifs_free_ipc(ses);
1962
1963	if (ses->ses_status == SES_EXITING && server->ops->logoff) {
1964		xid = get_xid();
1965		rc = server->ops->logoff(xid, ses);
1966		if (rc)
1967			cifs_server_dbg(VFS, "%s: Session Logoff failure rc=%d\n",
1968				__func__, rc);
1969		_free_xid(xid);
1970	}
1971
1972	spin_lock(&cifs_tcp_ses_lock);
1973	list_del_init(&ses->smb_ses_list);
1974	spin_unlock(&cifs_tcp_ses_lock);
1975
1976	chan_count = ses->chan_count;
1977
1978	/* close any extra channels */
1979	if (chan_count > 1) {
1980		int i;
1981
1982		for (i = 1; i < chan_count; i++) {
1983			if (ses->chans[i].iface) {
1984				kref_put(&ses->chans[i].iface->refcount, release_iface);
1985				ses->chans[i].iface = NULL;
1986			}
1987			cifs_put_tcp_session(ses->chans[i].server, 0);
1988			ses->chans[i].server = NULL;
1989		}
1990	}
1991
1992	sesInfoFree(ses);
1993	cifs_put_tcp_session(server, 0);
1994}
1995
1996#ifdef CONFIG_KEYS
1997
1998/* strlen("cifs:a:") + CIFS_MAX_DOMAINNAME_LEN + 1 */
1999#define CIFSCREDS_DESC_SIZE (7 + CIFS_MAX_DOMAINNAME_LEN + 1)
2000
2001/* Populate username and pw fields from keyring if possible */
2002static int
2003cifs_set_cifscreds(struct smb3_fs_context *ctx, struct cifs_ses *ses)
2004{
2005	int rc = 0;
2006	int is_domain = 0;
2007	const char *delim, *payload;
2008	char *desc;
2009	ssize_t len;
2010	struct key *key;
2011	struct TCP_Server_Info *server = ses->server;
2012	struct sockaddr_in *sa;
2013	struct sockaddr_in6 *sa6;
2014	const struct user_key_payload *upayload;
2015
2016	desc = kmalloc(CIFSCREDS_DESC_SIZE, GFP_KERNEL);
2017	if (!desc)
2018		return -ENOMEM;
2019
2020	/* try to find an address key first */
2021	switch (server->dstaddr.ss_family) {
2022	case AF_INET:
2023		sa = (struct sockaddr_in *)&server->dstaddr;
2024		sprintf(desc, "cifs:a:%pI4", &sa->sin_addr.s_addr);
2025		break;
2026	case AF_INET6:
2027		sa6 = (struct sockaddr_in6 *)&server->dstaddr;
2028		sprintf(desc, "cifs:a:%pI6c", &sa6->sin6_addr.s6_addr);
2029		break;
2030	default:
2031		cifs_dbg(FYI, "Bad ss_family (%hu)\n",
2032			 server->dstaddr.ss_family);
2033		rc = -EINVAL;
2034		goto out_err;
2035	}
2036
2037	cifs_dbg(FYI, "%s: desc=%s\n", __func__, desc);
2038	key = request_key(&key_type_logon, desc, "");
2039	if (IS_ERR(key)) {
2040		if (!ses->domainName) {
2041			cifs_dbg(FYI, "domainName is NULL\n");
2042			rc = PTR_ERR(key);
2043			goto out_err;
2044		}
2045
2046		/* didn't work, try to find a domain key */
2047		sprintf(desc, "cifs:d:%s", ses->domainName);
2048		cifs_dbg(FYI, "%s: desc=%s\n", __func__, desc);
2049		key = request_key(&key_type_logon, desc, "");
2050		if (IS_ERR(key)) {
2051			rc = PTR_ERR(key);
2052			goto out_err;
2053		}
2054		is_domain = 1;
2055	}
2056
2057	down_read(&key->sem);
2058	upayload = user_key_payload_locked(key);
2059	if (IS_ERR_OR_NULL(upayload)) {
2060		rc = upayload ? PTR_ERR(upayload) : -EINVAL;
2061		goto out_key_put;
2062	}
2063
2064	/* find first : in payload */
2065	payload = upayload->data;
2066	delim = strnchr(payload, upayload->datalen, ':');
2067	cifs_dbg(FYI, "payload=%s\n", payload);
2068	if (!delim) {
2069		cifs_dbg(FYI, "Unable to find ':' in payload (datalen=%d)\n",
2070			 upayload->datalen);
2071		rc = -EINVAL;
2072		goto out_key_put;
2073	}
2074
2075	len = delim - payload;
2076	if (len > CIFS_MAX_USERNAME_LEN || len <= 0) {
2077		cifs_dbg(FYI, "Bad value from username search (len=%zd)\n",
2078			 len);
2079		rc = -EINVAL;
2080		goto out_key_put;
2081	}
2082
2083	ctx->username = kstrndup(payload, len, GFP_KERNEL);
2084	if (!ctx->username) {
2085		cifs_dbg(FYI, "Unable to allocate %zd bytes for username\n",
2086			 len);
2087		rc = -ENOMEM;
2088		goto out_key_put;
2089	}
2090	cifs_dbg(FYI, "%s: username=%s\n", __func__, ctx->username);
2091
2092	len = key->datalen - (len + 1);
2093	if (len > CIFS_MAX_PASSWORD_LEN || len <= 0) {
2094		cifs_dbg(FYI, "Bad len for password search (len=%zd)\n", len);
2095		rc = -EINVAL;
2096		kfree(ctx->username);
2097		ctx->username = NULL;
2098		goto out_key_put;
2099	}
2100
2101	++delim;
2102	ctx->password = kstrndup(delim, len, GFP_KERNEL);
2103	if (!ctx->password) {
2104		cifs_dbg(FYI, "Unable to allocate %zd bytes for password\n",
2105			 len);
2106		rc = -ENOMEM;
2107		kfree(ctx->username);
2108		ctx->username = NULL;
2109		goto out_key_put;
2110	}
2111
2112	/*
2113	 * If we have a domain key then we must set the domainName in the
2114	 * for the request.
2115	 */
2116	if (is_domain && ses->domainName) {
2117		ctx->domainname = kstrdup(ses->domainName, GFP_KERNEL);
2118		if (!ctx->domainname) {
2119			cifs_dbg(FYI, "Unable to allocate %zd bytes for domain\n",
2120				 len);
2121			rc = -ENOMEM;
2122			kfree(ctx->username);
2123			ctx->username = NULL;
2124			kfree_sensitive(ctx->password);
2125			ctx->password = NULL;
2126			goto out_key_put;
2127		}
2128	}
2129
2130	strscpy(ctx->workstation_name, ses->workstation_name, sizeof(ctx->workstation_name));
2131
2132out_key_put:
2133	up_read(&key->sem);
2134	key_put(key);
2135out_err:
2136	kfree(desc);
2137	cifs_dbg(FYI, "%s: returning %d\n", __func__, rc);
2138	return rc;
2139}
2140#else /* ! CONFIG_KEYS */
2141static inline int
2142cifs_set_cifscreds(struct smb3_fs_context *ctx __attribute__((unused)),
2143		   struct cifs_ses *ses __attribute__((unused)))
2144{
2145	return -ENOSYS;
2146}
2147#endif /* CONFIG_KEYS */
2148
2149/**
2150 * cifs_get_smb_ses - get a session matching @ctx data from @server
2151 * @server: server to setup the session to
2152 * @ctx: superblock configuration context to use to setup the session
2153 *
2154 * This function assumes it is being called from cifs_mount() where we
2155 * already got a server reference (server refcount +1). See
2156 * cifs_get_tcon() for refcount explanations.
2157 */
2158struct cifs_ses *
2159cifs_get_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
2160{
2161	int rc = 0;
2162	unsigned int xid;
2163	struct cifs_ses *ses;
2164	struct sockaddr_in *addr = (struct sockaddr_in *)&server->dstaddr;
2165	struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&server->dstaddr;
2166
2167	xid = get_xid();
2168
2169	ses = cifs_find_smb_ses(server, ctx);
2170	if (ses) {
2171		cifs_dbg(FYI, "Existing smb sess found (status=%d)\n",
2172			 ses->ses_status);
2173
2174		spin_lock(&ses->chan_lock);
2175		if (cifs_chan_needs_reconnect(ses, server)) {
2176			spin_unlock(&ses->chan_lock);
2177			cifs_dbg(FYI, "Session needs reconnect\n");
2178
2179			mutex_lock(&ses->session_mutex);
2180			rc = cifs_negotiate_protocol(xid, ses, server);
2181			if (rc) {
2182				mutex_unlock(&ses->session_mutex);
2183				/* problem -- put our ses reference */
2184				cifs_put_smb_ses(ses);
2185				free_xid(xid);
2186				return ERR_PTR(rc);
2187			}
2188
2189			rc = cifs_setup_session(xid, ses, server,
2190						ctx->local_nls);
2191			if (rc) {
2192				mutex_unlock(&ses->session_mutex);
2193				/* problem -- put our reference */
2194				cifs_put_smb_ses(ses);
2195				free_xid(xid);
2196				return ERR_PTR(rc);
2197			}
2198			mutex_unlock(&ses->session_mutex);
2199
2200			spin_lock(&ses->chan_lock);
2201		}
2202		spin_unlock(&ses->chan_lock);
2203
2204		/* existing SMB ses has a server reference already */
2205		cifs_put_tcp_session(server, 0);
2206		free_xid(xid);
2207		return ses;
2208	}
2209
2210	rc = -ENOMEM;
2211
2212	cifs_dbg(FYI, "Existing smb sess not found\n");
2213	ses = sesInfoAlloc();
2214	if (ses == NULL)
2215		goto get_ses_fail;
2216
2217	/* new SMB session uses our server ref */
2218	ses->server = server;
2219	if (server->dstaddr.ss_family == AF_INET6)
2220		sprintf(ses->ip_addr, "%pI6", &addr6->sin6_addr);
2221	else
2222		sprintf(ses->ip_addr, "%pI4", &addr->sin_addr);
2223
2224	if (ctx->username) {
2225		ses->user_name = kstrdup(ctx->username, GFP_KERNEL);
2226		if (!ses->user_name)
2227			goto get_ses_fail;
2228	}
2229
2230	/* ctx->password freed at unmount */
2231	if (ctx->password) {
2232		ses->password = kstrdup(ctx->password, GFP_KERNEL);
2233		if (!ses->password)
2234			goto get_ses_fail;
2235	}
2236	if (ctx->domainname) {
2237		ses->domainName = kstrdup(ctx->domainname, GFP_KERNEL);
2238		if (!ses->domainName)
2239			goto get_ses_fail;
2240	}
2241
2242	strscpy(ses->workstation_name, ctx->workstation_name, sizeof(ses->workstation_name));
2243
2244	if (ctx->domainauto)
2245		ses->domainAuto = ctx->domainauto;
2246	ses->cred_uid = ctx->cred_uid;
2247	ses->linux_uid = ctx->linux_uid;
2248
2249	ses->sectype = ctx->sectype;
2250	ses->sign = ctx->sign;
2251
2252	/* add server as first channel */
2253	spin_lock(&ses->chan_lock);
2254	ses->chans[0].server = server;
2255	ses->chan_count = 1;
2256	ses->chan_max = ctx->multichannel ? ctx->max_channels:1;
2257	ses->chans_need_reconnect = 1;
2258	spin_unlock(&ses->chan_lock);
2259
2260	mutex_lock(&ses->session_mutex);
2261	rc = cifs_negotiate_protocol(xid, ses, server);
2262	if (!rc)
2263		rc = cifs_setup_session(xid, ses, server, ctx->local_nls);
2264	mutex_unlock(&ses->session_mutex);
2265
2266	/* each channel uses a different signing key */
2267	spin_lock(&ses->chan_lock);
2268	memcpy(ses->chans[0].signkey, ses->smb3signingkey,
2269	       sizeof(ses->smb3signingkey));
2270	spin_unlock(&ses->chan_lock);
2271
2272	if (rc)
2273		goto get_ses_fail;
2274
2275	/*
2276	 * success, put it on the list and add it as first channel
2277	 * note: the session becomes active soon after this. So you'll
2278	 * need to lock before changing something in the session.
2279	 */
2280	spin_lock(&cifs_tcp_ses_lock);
2281	list_add(&ses->smb_ses_list, &server->smb_ses_list);
2282	spin_unlock(&cifs_tcp_ses_lock);
2283
2284	cifs_setup_ipc(ses, ctx);
2285
2286	free_xid(xid);
2287
2288	return ses;
2289
2290get_ses_fail:
2291	sesInfoFree(ses);
2292	free_xid(xid);
2293	return ERR_PTR(rc);
2294}
2295
2296/* this function must be called with tc_lock held */
2297static int match_tcon(struct cifs_tcon *tcon, struct smb3_fs_context *ctx, bool dfs_super_cmp)
2298{
2299	if (tcon->status == TID_EXITING)
2300		return 0;
2301	/* Skip UNC validation when matching DFS superblocks */
2302	if (!dfs_super_cmp && strncmp(tcon->tree_name, ctx->UNC, MAX_TREE_SIZE))
2303		return 0;
2304	if (tcon->seal != ctx->seal)
2305		return 0;
2306	if (tcon->snapshot_time != ctx->snapshot_time)
2307		return 0;
2308	if (tcon->handle_timeout != ctx->handle_timeout)
2309		return 0;
2310	if (tcon->no_lease != ctx->no_lease)
2311		return 0;
2312	if (tcon->nodelete != ctx->nodelete)
2313		return 0;
2314	return 1;
2315}
2316
2317static struct cifs_tcon *
2318cifs_find_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx)
2319{
2320	struct cifs_tcon *tcon;
2321
2322	spin_lock(&cifs_tcp_ses_lock);
2323	list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
2324		spin_lock(&tcon->tc_lock);
2325		if (!match_tcon(tcon, ctx, false)) {
2326			spin_unlock(&tcon->tc_lock);
2327			continue;
2328		}
2329		++tcon->tc_count;
2330		spin_unlock(&tcon->tc_lock);
2331		spin_unlock(&cifs_tcp_ses_lock);
2332		return tcon;
2333	}
2334	spin_unlock(&cifs_tcp_ses_lock);
2335	return NULL;
2336}
2337
2338void
2339cifs_put_tcon(struct cifs_tcon *tcon)
2340{
2341	unsigned int xid;
2342	struct cifs_ses *ses;
2343
2344	/*
2345	 * IPC tcon share the lifetime of their session and are
2346	 * destroyed in the session put function
2347	 */
2348	if (tcon == NULL || tcon->ipc)
2349		return;
2350
2351	ses = tcon->ses;
2352	cifs_dbg(FYI, "%s: tc_count=%d\n", __func__, tcon->tc_count);
2353	spin_lock(&cifs_tcp_ses_lock);
2354	spin_lock(&tcon->tc_lock);
2355	if (--tcon->tc_count > 0) {
2356		spin_unlock(&tcon->tc_lock);
2357		spin_unlock(&cifs_tcp_ses_lock);
2358		return;
2359	}
2360
2361	/* tc_count can never go negative */
2362	WARN_ON(tcon->tc_count < 0);
2363
2364	list_del_init(&tcon->tcon_list);
2365	spin_unlock(&tcon->tc_lock);
2366	spin_unlock(&cifs_tcp_ses_lock);
2367
2368	/* cancel polling of interfaces */
2369	cancel_delayed_work_sync(&tcon->query_interfaces);
2370
2371	if (tcon->use_witness) {
2372		int rc;
2373
2374		rc = cifs_swn_unregister(tcon);
2375		if (rc < 0) {
2376			cifs_dbg(VFS, "%s: Failed to unregister for witness notifications: %d\n",
2377					__func__, rc);
2378		}
2379	}
2380
2381	xid = get_xid();
2382	if (ses->server->ops->tree_disconnect)
2383		ses->server->ops->tree_disconnect(xid, tcon);
2384	_free_xid(xid);
2385
2386	cifs_fscache_release_super_cookie(tcon);
2387	tconInfoFree(tcon);
2388	cifs_put_smb_ses(ses);
2389}
2390
2391/**
2392 * cifs_get_tcon - get a tcon matching @ctx data from @ses
2393 * @ses: smb session to issue the request on
2394 * @ctx: the superblock configuration context to use for building the
2395 *
2396 * - tcon refcount is the number of mount points using the tcon.
2397 * - ses refcount is the number of tcon using the session.
2398 *
2399 * 1. This function assumes it is being called from cifs_mount() where
2400 *    we already got a session reference (ses refcount +1).
2401 *
2402 * 2. Since we're in the context of adding a mount point, the end
2403 *    result should be either:
2404 *
2405 * a) a new tcon already allocated with refcount=1 (1 mount point) and
2406 *    its session refcount incremented (1 new tcon). This +1 was
2407 *    already done in (1).
2408 *
2409 * b) an existing tcon with refcount+1 (add a mount point to it) and
2410 *    identical ses refcount (no new tcon). Because of (1) we need to
2411 *    decrement the ses refcount.
2412 */
2413static struct cifs_tcon *
2414cifs_get_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx)
2415{
2416	int rc, xid;
2417	struct cifs_tcon *tcon;
2418
2419	tcon = cifs_find_tcon(ses, ctx);
2420	if (tcon) {
2421		/*
2422		 * tcon has refcount already incremented but we need to
2423		 * decrement extra ses reference gotten by caller (case b)
2424		 */
2425		cifs_dbg(FYI, "Found match on UNC path\n");
2426		cifs_put_smb_ses(ses);
2427		return tcon;
2428	}
2429
2430	if (!ses->server->ops->tree_connect) {
2431		rc = -ENOSYS;
2432		goto out_fail;
2433	}
2434
2435	tcon = tconInfoAlloc();
2436	if (tcon == NULL) {
2437		rc = -ENOMEM;
2438		goto out_fail;
2439	}
2440
2441	if (ctx->snapshot_time) {
2442		if (ses->server->vals->protocol_id == 0) {
2443			cifs_dbg(VFS,
2444			     "Use SMB2 or later for snapshot mount option\n");
2445			rc = -EOPNOTSUPP;
2446			goto out_fail;
2447		} else
2448			tcon->snapshot_time = ctx->snapshot_time;
2449	}
2450
2451	if (ctx->handle_timeout) {
2452		if (ses->server->vals->protocol_id == 0) {
2453			cifs_dbg(VFS,
2454			     "Use SMB2.1 or later for handle timeout option\n");
2455			rc = -EOPNOTSUPP;
2456			goto out_fail;
2457		} else
2458			tcon->handle_timeout = ctx->handle_timeout;
2459	}
2460
2461	tcon->ses = ses;
2462	if (ctx->password) {
2463		tcon->password = kstrdup(ctx->password, GFP_KERNEL);
2464		if (!tcon->password) {
2465			rc = -ENOMEM;
2466			goto out_fail;
2467		}
2468	}
2469
2470	if (ctx->seal) {
2471		if (ses->server->vals->protocol_id == 0) {
2472			cifs_dbg(VFS,
2473				 "SMB3 or later required for encryption\n");
2474			rc = -EOPNOTSUPP;
2475			goto out_fail;
2476		} else if (tcon->ses->server->capabilities &
2477					SMB2_GLOBAL_CAP_ENCRYPTION)
2478			tcon->seal = true;
2479		else {
2480			cifs_dbg(VFS, "Encryption is not supported on share\n");
2481			rc = -EOPNOTSUPP;
2482			goto out_fail;
2483		}
2484	}
2485
2486	if (ctx->linux_ext) {
2487		if (ses->server->posix_ext_supported) {
2488			tcon->posix_extensions = true;
2489			pr_warn_once("SMB3.11 POSIX Extensions are experimental\n");
2490		} else if ((ses->server->vals->protocol_id == SMB311_PROT_ID) ||
2491		    (strcmp(ses->server->vals->version_string,
2492		     SMB3ANY_VERSION_STRING) == 0) ||
2493		    (strcmp(ses->server->vals->version_string,
2494		     SMBDEFAULT_VERSION_STRING) == 0)) {
2495			cifs_dbg(VFS, "Server does not support mounting with posix SMB3.11 extensions\n");
2496			rc = -EOPNOTSUPP;
2497			goto out_fail;
2498		} else {
2499			cifs_dbg(VFS, "Check vers= mount option. SMB3.11 "
2500				"disabled but required for POSIX extensions\n");
2501			rc = -EOPNOTSUPP;
2502			goto out_fail;
2503		}
2504	}
2505
2506	xid = get_xid();
2507	rc = ses->server->ops->tree_connect(xid, ses, ctx->UNC, tcon,
2508					    ctx->local_nls);
2509	free_xid(xid);
2510	cifs_dbg(FYI, "Tcon rc = %d\n", rc);
2511	if (rc)
2512		goto out_fail;
2513
2514	tcon->use_persistent = false;
2515	/* check if SMB2 or later, CIFS does not support persistent handles */
2516	if (ctx->persistent) {
2517		if (ses->server->vals->protocol_id == 0) {
2518			cifs_dbg(VFS,
2519			     "SMB3 or later required for persistent handles\n");
2520			rc = -EOPNOTSUPP;
2521			goto out_fail;
2522		} else if (ses->server->capabilities &
2523			   SMB2_GLOBAL_CAP_PERSISTENT_HANDLES)
2524			tcon->use_persistent = true;
2525		else /* persistent handles requested but not supported */ {
2526			cifs_dbg(VFS,
2527				"Persistent handles not supported on share\n");
2528			rc = -EOPNOTSUPP;
2529			goto out_fail;
2530		}
2531	} else if ((tcon->capabilities & SMB2_SHARE_CAP_CONTINUOUS_AVAILABILITY)
2532	     && (ses->server->capabilities & SMB2_GLOBAL_CAP_PERSISTENT_HANDLES)
2533	     && (ctx->nopersistent == false)) {
2534		cifs_dbg(FYI, "enabling persistent handles\n");
2535		tcon->use_persistent = true;
2536	} else if (ctx->resilient) {
2537		if (ses->server->vals->protocol_id == 0) {
2538			cifs_dbg(VFS,
2539			     "SMB2.1 or later required for resilient handles\n");
2540			rc = -EOPNOTSUPP;
2541			goto out_fail;
2542		}
2543		tcon->use_resilient = true;
2544	}
2545
2546	tcon->use_witness = false;
2547	if (IS_ENABLED(CONFIG_CIFS_SWN_UPCALL) && ctx->witness) {
2548		if (ses->server->vals->protocol_id >= SMB30_PROT_ID) {
2549			if (tcon->capabilities & SMB2_SHARE_CAP_CLUSTER) {
2550				/*
2551				 * Set witness in use flag in first place
2552				 * to retry registration in the echo task
2553				 */
2554				tcon->use_witness = true;
2555				/* And try to register immediately */
2556				rc = cifs_swn_register(tcon);
2557				if (rc < 0) {
2558					cifs_dbg(VFS, "Failed to register for witness notifications: %d\n", rc);
2559					goto out_fail;
2560				}
2561			} else {
2562				/* TODO: try to extend for non-cluster uses (eg multichannel) */
2563				cifs_dbg(VFS, "witness requested on mount but no CLUSTER capability on share\n");
2564				rc = -EOPNOTSUPP;
2565				goto out_fail;
2566			}
2567		} else {
2568			cifs_dbg(VFS, "SMB3 or later required for witness option\n");
2569			rc = -EOPNOTSUPP;
2570			goto out_fail;
2571		}
2572	}
2573
2574	/* If the user really knows what they are doing they can override */
2575	if (tcon->share_flags & SMB2_SHAREFLAG_NO_CACHING) {
2576		if (ctx->cache_ro)
2577			cifs_dbg(VFS, "cache=ro requested on mount but NO_CACHING flag set on share\n");
2578		else if (ctx->cache_rw)
2579			cifs_dbg(VFS, "cache=singleclient requested on mount but NO_CACHING flag set on share\n");
2580	}
2581
2582	if (ctx->no_lease) {
2583		if (ses->server->vals->protocol_id == 0) {
2584			cifs_dbg(VFS,
2585				"SMB2 or later required for nolease option\n");
2586			rc = -EOPNOTSUPP;
2587			goto out_fail;
2588		} else
2589			tcon->no_lease = ctx->no_lease;
2590	}
2591
2592	/*
2593	 * We can have only one retry value for a connection to a share so for
2594	 * resources mounted more than once to the same server share the last
2595	 * value passed in for the retry flag is used.
2596	 */
2597	tcon->retry = ctx->retry;
2598	tcon->nocase = ctx->nocase;
2599	tcon->broken_sparse_sup = ctx->no_sparse;
2600	if (ses->server->capabilities & SMB2_GLOBAL_CAP_DIRECTORY_LEASING)
2601		tcon->nohandlecache = ctx->nohandlecache;
2602	else
2603		tcon->nohandlecache = true;
2604	tcon->nodelete = ctx->nodelete;
2605	tcon->local_lease = ctx->local_lease;
2606	INIT_LIST_HEAD(&tcon->pending_opens);
2607	tcon->status = TID_GOOD;
2608
2609	INIT_DELAYED_WORK(&tcon->query_interfaces,
2610			  smb2_query_server_interfaces);
2611	if (ses->server->dialect >= SMB30_PROT_ID &&
2612	    (ses->server->capabilities & SMB2_GLOBAL_CAP_MULTI_CHANNEL)) {
2613		/* schedule query interfaces poll */
2614		queue_delayed_work(cifsiod_wq, &tcon->query_interfaces,
2615				   (SMB_INTERFACE_POLL_INTERVAL * HZ));
2616	}
2617
2618	spin_lock(&cifs_tcp_ses_lock);
2619	list_add(&tcon->tcon_list, &ses->tcon_list);
2620	spin_unlock(&cifs_tcp_ses_lock);
2621
2622	return tcon;
2623
2624out_fail:
2625	tconInfoFree(tcon);
2626	return ERR_PTR(rc);
2627}
2628
2629void
2630cifs_put_tlink(struct tcon_link *tlink)
2631{
2632	if (!tlink || IS_ERR(tlink))
2633		return;
2634
2635	if (!atomic_dec_and_test(&tlink->tl_count) ||
2636	    test_bit(TCON_LINK_IN_TREE, &tlink->tl_flags)) {
2637		tlink->tl_time = jiffies;
2638		return;
2639	}
2640
2641	if (!IS_ERR(tlink_tcon(tlink)))
2642		cifs_put_tcon(tlink_tcon(tlink));
2643	kfree(tlink);
2644	return;
2645}
2646
2647static int
2648compare_mount_options(struct super_block *sb, struct cifs_mnt_data *mnt_data)
2649{
2650	struct cifs_sb_info *old = CIFS_SB(sb);
2651	struct cifs_sb_info *new = mnt_data->cifs_sb;
2652	unsigned int oldflags = old->mnt_cifs_flags & CIFS_MOUNT_MASK;
2653	unsigned int newflags = new->mnt_cifs_flags & CIFS_MOUNT_MASK;
2654
2655	if ((sb->s_flags & CIFS_MS_MASK) != (mnt_data->flags & CIFS_MS_MASK))
2656		return 0;
2657
2658	if (old->mnt_cifs_serverino_autodisabled)
2659		newflags &= ~CIFS_MOUNT_SERVER_INUM;
2660
2661	if (oldflags != newflags)
2662		return 0;
2663
2664	/*
2665	 * We want to share sb only if we don't specify an r/wsize or
2666	 * specified r/wsize is greater than or equal to existing one.
2667	 */
2668	if (new->ctx->wsize && new->ctx->wsize < old->ctx->wsize)
2669		return 0;
2670
2671	if (new->ctx->rsize && new->ctx->rsize < old->ctx->rsize)
2672		return 0;
2673
2674	if (!uid_eq(old->ctx->linux_uid, new->ctx->linux_uid) ||
2675	    !gid_eq(old->ctx->linux_gid, new->ctx->linux_gid))
2676		return 0;
2677
2678	if (old->ctx->file_mode != new->ctx->file_mode ||
2679	    old->ctx->dir_mode != new->ctx->dir_mode)
2680		return 0;
2681
2682	if (strcmp(old->local_nls->charset, new->local_nls->charset))
2683		return 0;
2684
2685	if (old->ctx->acregmax != new->ctx->acregmax)
2686		return 0;
2687	if (old->ctx->acdirmax != new->ctx->acdirmax)
2688		return 0;
2689	if (old->ctx->closetimeo != new->ctx->closetimeo)
2690		return 0;
2691
2692	return 1;
2693}
2694
2695static int
2696match_prepath(struct super_block *sb, struct cifs_mnt_data *mnt_data)
2697{
2698	struct cifs_sb_info *old = CIFS_SB(sb);
2699	struct cifs_sb_info *new = mnt_data->cifs_sb;
2700	bool old_set = (old->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH) &&
2701		old->prepath;
2702	bool new_set = (new->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH) &&
2703		new->prepath;
2704
2705	if (old_set && new_set && !strcmp(new->prepath, old->prepath))
2706		return 1;
2707	else if (!old_set && !new_set)
2708		return 1;
2709
2710	return 0;
2711}
2712
2713int
2714cifs_match_super(struct super_block *sb, void *data)
2715{
2716	struct cifs_mnt_data *mnt_data = data;
2717	struct smb3_fs_context *ctx;
2718	struct cifs_sb_info *cifs_sb;
2719	struct TCP_Server_Info *tcp_srv;
2720	struct cifs_ses *ses;
2721	struct cifs_tcon *tcon;
2722	struct tcon_link *tlink;
2723	bool dfs_super_cmp;
2724	int rc = 0;
2725
2726	spin_lock(&cifs_tcp_ses_lock);
2727	cifs_sb = CIFS_SB(sb);
2728	tlink = cifs_get_tlink(cifs_sb_master_tlink(cifs_sb));
2729	if (tlink == NULL) {
2730		/* can not match superblock if tlink were ever null */
2731		spin_unlock(&cifs_tcp_ses_lock);
2732		return 0;
2733	}
2734	tcon = tlink_tcon(tlink);
2735	ses = tcon->ses;
2736	tcp_srv = ses->server;
2737
2738	dfs_super_cmp = IS_ENABLED(CONFIG_CIFS_DFS_UPCALL) && tcp_srv->origin_fullpath;
2739
2740	ctx = mnt_data->ctx;
2741
2742	spin_lock(&tcp_srv->srv_lock);
2743	spin_lock(&ses->ses_lock);
2744	spin_lock(&tcon->tc_lock);
2745	if (!match_server(tcp_srv, ctx, dfs_super_cmp) ||
2746	    !match_session(ses, ctx) ||
2747	    !match_tcon(tcon, ctx, dfs_super_cmp) ||
2748	    !match_prepath(sb, mnt_data)) {
2749		rc = 0;
2750		goto out;
2751	}
2752
2753	rc = compare_mount_options(sb, mnt_data);
2754out:
2755	spin_unlock(&tcon->tc_lock);
2756	spin_unlock(&ses->ses_lock);
2757	spin_unlock(&tcp_srv->srv_lock);
2758
2759	spin_unlock(&cifs_tcp_ses_lock);
2760	cifs_put_tlink(tlink);
2761	return rc;
2762}
2763
2764#ifdef CONFIG_DEBUG_LOCK_ALLOC
2765static struct lock_class_key cifs_key[2];
2766static struct lock_class_key cifs_slock_key[2];
2767
2768static inline void
2769cifs_reclassify_socket4(struct socket *sock)
2770{
2771	struct sock *sk = sock->sk;
2772	BUG_ON(!sock_allow_reclassification(sk));
2773	sock_lock_init_class_and_name(sk, "slock-AF_INET-CIFS",
2774		&cifs_slock_key[0], "sk_lock-AF_INET-CIFS", &cifs_key[0]);
2775}
2776
2777static inline void
2778cifs_reclassify_socket6(struct socket *sock)
2779{
2780	struct sock *sk = sock->sk;
2781	BUG_ON(!sock_allow_reclassification(sk));
2782	sock_lock_init_class_and_name(sk, "slock-AF_INET6-CIFS",
2783		&cifs_slock_key[1], "sk_lock-AF_INET6-CIFS", &cifs_key[1]);
2784}
2785#else
2786static inline void
2787cifs_reclassify_socket4(struct socket *sock)
2788{
2789}
2790
2791static inline void
2792cifs_reclassify_socket6(struct socket *sock)
2793{
2794}
2795#endif
2796
2797/* See RFC1001 section 14 on representation of Netbios names */
2798static void rfc1002mangle(char *target, char *source, unsigned int length)
2799{
2800	unsigned int i, j;
2801
2802	for (i = 0, j = 0; i < (length); i++) {
2803		/* mask a nibble at a time and encode */
2804		target[j] = 'A' + (0x0F & (source[i] >> 4));
2805		target[j+1] = 'A' + (0x0F & source[i]);
2806		j += 2;
2807	}
2808
2809}
2810
2811static int
2812bind_socket(struct TCP_Server_Info *server)
2813{
2814	int rc = 0;
2815	if (server->srcaddr.ss_family != AF_UNSPEC) {
2816		/* Bind to the specified local IP address */
2817		struct socket *socket = server->ssocket;
2818		rc = socket->ops->bind(socket,
2819				       (struct sockaddr *) &server->srcaddr,
2820				       sizeof(server->srcaddr));
2821		if (rc < 0) {
2822			struct sockaddr_in *saddr4;
2823			struct sockaddr_in6 *saddr6;
2824			saddr4 = (struct sockaddr_in *)&server->srcaddr;
2825			saddr6 = (struct sockaddr_in6 *)&server->srcaddr;
2826			if (saddr6->sin6_family == AF_INET6)
2827				cifs_server_dbg(VFS, "Failed to bind to: %pI6c, error: %d\n",
2828					 &saddr6->sin6_addr, rc);
2829			else
2830				cifs_server_dbg(VFS, "Failed to bind to: %pI4, error: %d\n",
2831					 &saddr4->sin_addr.s_addr, rc);
2832		}
2833	}
2834	return rc;
2835}
2836
2837static int
2838ip_rfc1001_connect(struct TCP_Server_Info *server)
2839{
2840	int rc = 0;
2841	/*
2842	 * some servers require RFC1001 sessinit before sending
2843	 * negprot - BB check reconnection in case where second
2844	 * sessinit is sent but no second negprot
2845	 */
2846	struct rfc1002_session_packet *ses_init_buf;
2847	unsigned int req_noscope_len;
2848	struct smb_hdr *smb_buf;
2849
2850	ses_init_buf = kzalloc(sizeof(struct rfc1002_session_packet),
2851			       GFP_KERNEL);
2852
2853	if (ses_init_buf) {
2854		ses_init_buf->trailer.session_req.called_len = 32;
2855
2856		if (server->server_RFC1001_name[0] != 0)
2857			rfc1002mangle(ses_init_buf->trailer.
2858				      session_req.called_name,
2859				      server->server_RFC1001_name,
2860				      RFC1001_NAME_LEN_WITH_NULL);
2861		else
2862			rfc1002mangle(ses_init_buf->trailer.
2863				      session_req.called_name,
2864				      DEFAULT_CIFS_CALLED_NAME,
2865				      RFC1001_NAME_LEN_WITH_NULL);
2866
2867		ses_init_buf->trailer.session_req.calling_len = 32;
2868
2869		/*
2870		 * calling name ends in null (byte 16) from old smb
2871		 * convention.
2872		 */
2873		if (server->workstation_RFC1001_name[0] != 0)
2874			rfc1002mangle(ses_init_buf->trailer.
2875				      session_req.calling_name,
2876				      server->workstation_RFC1001_name,
2877				      RFC1001_NAME_LEN_WITH_NULL);
2878		else
2879			rfc1002mangle(ses_init_buf->trailer.
2880				      session_req.calling_name,
2881				      "LINUX_CIFS_CLNT",
2882				      RFC1001_NAME_LEN_WITH_NULL);
2883
2884		ses_init_buf->trailer.session_req.scope1 = 0;
2885		ses_init_buf->trailer.session_req.scope2 = 0;
2886		smb_buf = (struct smb_hdr *)ses_init_buf;
2887
2888		/* sizeof RFC1002_SESSION_REQUEST with no scopes */
2889		req_noscope_len = sizeof(struct rfc1002_session_packet) - 2;
2890
2891		/* == cpu_to_be32(0x81000044) */
2892		smb_buf->smb_buf_length =
2893			cpu_to_be32((RFC1002_SESSION_REQUEST << 24) | req_noscope_len);
2894		rc = smb_send(server, smb_buf, 0x44);
2895		kfree(ses_init_buf);
2896		/*
2897		 * RFC1001 layer in at least one server
2898		 * requires very short break before negprot
2899		 * presumably because not expecting negprot
2900		 * to follow so fast.  This is a simple
2901		 * solution that works without
2902		 * complicating the code and causes no
2903		 * significant slowing down on mount
2904		 * for everyone else
2905		 */
2906		usleep_range(1000, 2000);
2907	}
2908	/*
2909	 * else the negprot may still work without this
2910	 * even though malloc failed
2911	 */
2912
2913	return rc;
2914}
2915
2916static int
2917generic_ip_connect(struct TCP_Server_Info *server)
2918{
2919	int rc = 0;
2920	__be16 sport;
2921	int slen, sfamily;
2922	struct socket *socket = server->ssocket;
2923	struct sockaddr *saddr;
2924
2925	saddr = (struct sockaddr *) &server->dstaddr;
2926
2927	if (server->dstaddr.ss_family == AF_INET6) {
2928		struct sockaddr_in6 *ipv6 = (struct sockaddr_in6 *)&server->dstaddr;
2929
2930		sport = ipv6->sin6_port;
2931		slen = sizeof(struct sockaddr_in6);
2932		sfamily = AF_INET6;
2933		cifs_dbg(FYI, "%s: connecting to [%pI6]:%d\n", __func__, &ipv6->sin6_addr,
2934				ntohs(sport));
2935	} else {
2936		struct sockaddr_in *ipv4 = (struct sockaddr_in *)&server->dstaddr;
2937
2938		sport = ipv4->sin_port;
2939		slen = sizeof(struct sockaddr_in);
2940		sfamily = AF_INET;
2941		cifs_dbg(FYI, "%s: connecting to %pI4:%d\n", __func__, &ipv4->sin_addr,
2942				ntohs(sport));
2943	}
2944
2945	if (socket == NULL) {
2946		rc = __sock_create(cifs_net_ns(server), sfamily, SOCK_STREAM,
2947				   IPPROTO_TCP, &socket, 1);
2948		if (rc < 0) {
2949			cifs_server_dbg(VFS, "Error %d creating socket\n", rc);
2950			server->ssocket = NULL;
2951			return rc;
2952		}
2953
2954		/* BB other socket options to set KEEPALIVE, NODELAY? */
2955		cifs_dbg(FYI, "Socket created\n");
2956		server->ssocket = socket;
2957		socket->sk->sk_allocation = GFP_NOFS;
2958		socket->sk->sk_use_task_frag = false;
2959		if (sfamily == AF_INET6)
2960			cifs_reclassify_socket6(socket);
2961		else
2962			cifs_reclassify_socket4(socket);
2963	}
2964
2965	rc = bind_socket(server);
2966	if (rc < 0)
2967		return rc;
2968
2969	/*
2970	 * Eventually check for other socket options to change from
2971	 * the default. sock_setsockopt not used because it expects
2972	 * user space buffer
2973	 */
2974	socket->sk->sk_rcvtimeo = 7 * HZ;
2975	socket->sk->sk_sndtimeo = 5 * HZ;
2976
2977	/* make the bufsizes depend on wsize/rsize and max requests */
2978	if (server->noautotune) {
2979		if (socket->sk->sk_sndbuf < (200 * 1024))
2980			socket->sk->sk_sndbuf = 200 * 1024;
2981		if (socket->sk->sk_rcvbuf < (140 * 1024))
2982			socket->sk->sk_rcvbuf = 140 * 1024;
2983	}
2984
2985	if (server->tcp_nodelay)
2986		tcp_sock_set_nodelay(socket->sk);
2987
2988	cifs_dbg(FYI, "sndbuf %d rcvbuf %d rcvtimeo 0x%lx\n",
2989		 socket->sk->sk_sndbuf,
2990		 socket->sk->sk_rcvbuf, socket->sk->sk_rcvtimeo);
2991
2992	rc = socket->ops->connect(socket, saddr, slen,
2993				  server->noblockcnt ? O_NONBLOCK : 0);
2994	/*
2995	 * When mounting SMB root file systems, we do not want to block in
2996	 * connect. Otherwise bail out and then let cifs_reconnect() perform
2997	 * reconnect failover - if possible.
2998	 */
2999	if (server->noblockcnt && rc == -EINPROGRESS)
3000		rc = 0;
3001	if (rc < 0) {
3002		cifs_dbg(FYI, "Error %d connecting to server\n", rc);
3003		trace_smb3_connect_err(server->hostname, server->conn_id, &server->dstaddr, rc);
3004		sock_release(socket);
3005		server->ssocket = NULL;
3006		return rc;
3007	}
3008	trace_smb3_connect_done(server->hostname, server->conn_id, &server->dstaddr);
3009	if (sport == htons(RFC1001_PORT))
3010		rc = ip_rfc1001_connect(server);
3011
3012	return rc;
3013}
3014
3015static int
3016ip_connect(struct TCP_Server_Info *server)
3017{
3018	__be16 *sport;
3019	struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&server->dstaddr;
3020	struct sockaddr_in *addr = (struct sockaddr_in *)&server->dstaddr;
3021
3022	if (server->dstaddr.ss_family == AF_INET6)
3023		sport = &addr6->sin6_port;
3024	else
3025		sport = &addr->sin_port;
3026
3027	if (*sport == 0) {
3028		int rc;
3029
3030		/* try with 445 port at first */
3031		*sport = htons(CIFS_PORT);
3032
3033		rc = generic_ip_connect(server);
3034		if (rc >= 0)
3035			return rc;
3036
3037		/* if it failed, try with 139 port */
3038		*sport = htons(RFC1001_PORT);
3039	}
3040
3041	return generic_ip_connect(server);
3042}
3043
3044#ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
3045void reset_cifs_unix_caps(unsigned int xid, struct cifs_tcon *tcon,
3046			  struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
3047{
3048	/*
3049	 * If we are reconnecting then should we check to see if
3050	 * any requested capabilities changed locally e.g. via
3051	 * remount but we can not do much about it here
3052	 * if they have (even if we could detect it by the following)
3053	 * Perhaps we could add a backpointer to array of sb from tcon
3054	 * or if we change to make all sb to same share the same
3055	 * sb as NFS - then we only have one backpointer to sb.
3056	 * What if we wanted to mount the server share twice once with
3057	 * and once without posixacls or posix paths?
3058	 */
3059	__u64 saved_cap = le64_to_cpu(tcon->fsUnixInfo.Capability);
3060
3061	if (ctx && ctx->no_linux_ext) {
3062		tcon->fsUnixInfo.Capability = 0;
3063		tcon->unix_ext = 0; /* Unix Extensions disabled */
3064		cifs_dbg(FYI, "Linux protocol extensions disabled\n");
3065		return;
3066	} else if (ctx)
3067		tcon->unix_ext = 1; /* Unix Extensions supported */
3068
3069	if (!tcon->unix_ext) {
3070		cifs_dbg(FYI, "Unix extensions disabled so not set on reconnect\n");
3071		return;
3072	}
3073
3074	if (!CIFSSMBQFSUnixInfo(xid, tcon)) {
3075		__u64 cap = le64_to_cpu(tcon->fsUnixInfo.Capability);
3076		cifs_dbg(FYI, "unix caps which server supports %lld\n", cap);
3077		/*
3078		 * check for reconnect case in which we do not
3079		 * want to change the mount behavior if we can avoid it
3080		 */
3081		if (ctx == NULL) {
3082			/*
3083			 * turn off POSIX ACL and PATHNAMES if not set
3084			 * originally at mount time
3085			 */
3086			if ((saved_cap & CIFS_UNIX_POSIX_ACL_CAP) == 0)
3087				cap &= ~CIFS_UNIX_POSIX_ACL_CAP;
3088			if ((saved_cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) == 0) {
3089				if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP)
3090					cifs_dbg(VFS, "POSIXPATH support change\n");
3091				cap &= ~CIFS_UNIX_POSIX_PATHNAMES_CAP;
3092			} else if ((cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) == 0) {
3093				cifs_dbg(VFS, "possible reconnect error\n");
3094				cifs_dbg(VFS, "server disabled POSIX path support\n");
3095			}
3096		}
3097
3098		if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)
3099			cifs_dbg(VFS, "per-share encryption not supported yet\n");
3100
3101		cap &= CIFS_UNIX_CAP_MASK;
3102		if (ctx && ctx->no_psx_acl)
3103			cap &= ~CIFS_UNIX_POSIX_ACL_CAP;
3104		else if (CIFS_UNIX_POSIX_ACL_CAP & cap) {
3105			cifs_dbg(FYI, "negotiated posix acl support\n");
3106			if (cifs_sb)
3107				cifs_sb->mnt_cifs_flags |=
3108					CIFS_MOUNT_POSIXACL;
3109		}
3110
3111		if (ctx && ctx->posix_paths == 0)
3112			cap &= ~CIFS_UNIX_POSIX_PATHNAMES_CAP;
3113		else if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) {
3114			cifs_dbg(FYI, "negotiate posix pathnames\n");
3115			if (cifs_sb)
3116				cifs_sb->mnt_cifs_flags |=
3117					CIFS_MOUNT_POSIX_PATHS;
3118		}
3119
3120		cifs_dbg(FYI, "Negotiate caps 0x%x\n", (int)cap);
3121#ifdef CONFIG_CIFS_DEBUG2
3122		if (cap & CIFS_UNIX_FCNTL_CAP)
3123			cifs_dbg(FYI, "FCNTL cap\n");
3124		if (cap & CIFS_UNIX_EXTATTR_CAP)
3125			cifs_dbg(FYI, "EXTATTR cap\n");
3126		if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP)
3127			cifs_dbg(FYI, "POSIX path cap\n");
3128		if (cap & CIFS_UNIX_XATTR_CAP)
3129			cifs_dbg(FYI, "XATTR cap\n");
3130		if (cap & CIFS_UNIX_POSIX_ACL_CAP)
3131			cifs_dbg(FYI, "POSIX ACL cap\n");
3132		if (cap & CIFS_UNIX_LARGE_READ_CAP)
3133			cifs_dbg(FYI, "very large read cap\n");
3134		if (cap & CIFS_UNIX_LARGE_WRITE_CAP)
3135			cifs_dbg(FYI, "very large write cap\n");
3136		if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_CAP)
3137			cifs_dbg(FYI, "transport encryption cap\n");
3138		if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)
3139			cifs_dbg(FYI, "mandatory transport encryption cap\n");
3140#endif /* CIFS_DEBUG2 */
3141		if (CIFSSMBSetFSUnixInfo(xid, tcon, cap)) {
3142			if (ctx == NULL)
3143				cifs_dbg(FYI, "resetting capabilities failed\n");
3144			else
3145				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");
3146
3147		}
3148	}
3149}
3150#endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
3151
3152int cifs_setup_cifs_sb(struct cifs_sb_info *cifs_sb)
3153{
3154	struct smb3_fs_context *ctx = cifs_sb->ctx;
3155
3156	INIT_DELAYED_WORK(&cifs_sb->prune_tlinks, cifs_prune_tlinks);
3157
3158	spin_lock_init(&cifs_sb->tlink_tree_lock);
3159	cifs_sb->tlink_tree = RB_ROOT;
3160
3161	cifs_dbg(FYI, "file mode: %04ho  dir mode: %04ho\n",
3162		 ctx->file_mode, ctx->dir_mode);
3163
3164	/* this is needed for ASCII cp to Unicode converts */
3165	if (ctx->iocharset == NULL) {
3166		/* load_nls_default cannot return null */
3167		cifs_sb->local_nls = load_nls_default();
3168	} else {
3169		cifs_sb->local_nls = load_nls(ctx->iocharset);
3170		if (cifs_sb->local_nls == NULL) {
3171			cifs_dbg(VFS, "CIFS mount error: iocharset %s not found\n",
3172				 ctx->iocharset);
3173			return -ELIBACC;
3174		}
3175	}
3176	ctx->local_nls = cifs_sb->local_nls;
3177
3178	smb3_update_mnt_flags(cifs_sb);
3179
3180	if (ctx->direct_io)
3181		cifs_dbg(FYI, "mounting share using direct i/o\n");
3182	if (ctx->cache_ro) {
3183		cifs_dbg(VFS, "mounting share with read only caching. Ensure that the share will not be modified while in use.\n");
3184		cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_RO_CACHE;
3185	} else if (ctx->cache_rw) {
3186		cifs_dbg(VFS, "mounting share in single client RW caching mode. Ensure that no other systems will be accessing the share.\n");
3187		cifs_sb->mnt_cifs_flags |= (CIFS_MOUNT_RO_CACHE |
3188					    CIFS_MOUNT_RW_CACHE);
3189	}
3190
3191	if ((ctx->cifs_acl) && (ctx->dynperm))
3192		cifs_dbg(VFS, "mount option dynperm ignored if cifsacl mount option supported\n");
3193
3194	if (ctx->prepath) {
3195		cifs_sb->prepath = kstrdup(ctx->prepath, GFP_KERNEL);
3196		if (cifs_sb->prepath == NULL)
3197			return -ENOMEM;
3198		cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
3199	}
3200
3201	return 0;
3202}
3203
3204/* Release all succeed connections */
3205void cifs_mount_put_conns(struct cifs_mount_ctx *mnt_ctx)
3206{
3207	int rc = 0;
3208
3209	if (mnt_ctx->tcon)
3210		cifs_put_tcon(mnt_ctx->tcon);
3211	else if (mnt_ctx->ses)
3212		cifs_put_smb_ses(mnt_ctx->ses);
3213	else if (mnt_ctx->server)
3214		cifs_put_tcp_session(mnt_ctx->server, 0);
3215	mnt_ctx->cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_POSIX_PATHS;
3216	free_xid(mnt_ctx->xid);
3217}
3218
3219int cifs_mount_get_session(struct cifs_mount_ctx *mnt_ctx)
3220{
3221	struct TCP_Server_Info *server = NULL;
3222	struct smb3_fs_context *ctx;
3223	struct cifs_ses *ses = NULL;
3224	unsigned int xid;
3225	int rc = 0;
3226
3227	xid = get_xid();
3228
3229	if (WARN_ON_ONCE(!mnt_ctx || !mnt_ctx->fs_ctx)) {
3230		rc = -EINVAL;
3231		goto out;
3232	}
3233	ctx = mnt_ctx->fs_ctx;
3234
3235	/* get a reference to a tcp session */
3236	server = cifs_get_tcp_session(ctx, NULL);
3237	if (IS_ERR(server)) {
3238		rc = PTR_ERR(server);
3239		server = NULL;
3240		goto out;
3241	}
3242
3243	/* get a reference to a SMB session */
3244	ses = cifs_get_smb_ses(server, ctx);
3245	if (IS_ERR(ses)) {
3246		rc = PTR_ERR(ses);
3247		ses = NULL;
3248		goto out;
3249	}
3250
3251	if ((ctx->persistent == true) && (!(ses->server->capabilities &
3252					    SMB2_GLOBAL_CAP_PERSISTENT_HANDLES))) {
3253		cifs_server_dbg(VFS, "persistent handles not supported by server\n");
3254		rc = -EOPNOTSUPP;
3255	}
3256
3257out:
3258	mnt_ctx->xid = xid;
3259	mnt_ctx->server = server;
3260	mnt_ctx->ses = ses;
3261	mnt_ctx->tcon = NULL;
3262
3263	return rc;
3264}
3265
3266int cifs_mount_get_tcon(struct cifs_mount_ctx *mnt_ctx)
3267{
3268	struct TCP_Server_Info *server;
3269	struct cifs_sb_info *cifs_sb;
3270	struct smb3_fs_context *ctx;
3271	struct cifs_tcon *tcon = NULL;
3272	int rc = 0;
3273
3274	if (WARN_ON_ONCE(!mnt_ctx || !mnt_ctx->server || !mnt_ctx->ses || !mnt_ctx->fs_ctx ||
3275			 !mnt_ctx->cifs_sb)) {
3276		rc = -EINVAL;
3277		goto out;
3278	}
3279	server = mnt_ctx->server;
3280	ctx = mnt_ctx->fs_ctx;
3281	cifs_sb = mnt_ctx->cifs_sb;
3282
3283	/* search for existing tcon to this server share */
3284	tcon = cifs_get_tcon(mnt_ctx->ses, ctx);
3285	if (IS_ERR(tcon)) {
3286		rc = PTR_ERR(tcon);
3287		tcon = NULL;
3288		goto out;
3289	}
3290
3291	/* if new SMB3.11 POSIX extensions are supported do not remap / and \ */
3292	if (tcon->posix_extensions)
3293		cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_POSIX_PATHS;
3294
3295#ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
3296	/* tell server which Unix caps we support */
3297	if (cap_unix(tcon->ses)) {
3298		/*
3299		 * reset of caps checks mount to see if unix extensions disabled
3300		 * for just this mount.
3301		 */
3302		reset_cifs_unix_caps(mnt_ctx->xid, tcon, cifs_sb, ctx);
3303		spin_lock(&tcon->ses->server->srv_lock);
3304		if ((tcon->ses->server->tcpStatus == CifsNeedReconnect) &&
3305		    (le64_to_cpu(tcon->fsUnixInfo.Capability) &
3306		     CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)) {
3307			spin_unlock(&tcon->ses->server->srv_lock);
3308			rc = -EACCES;
3309			goto out;
3310		}
3311		spin_unlock(&tcon->ses->server->srv_lock);
3312	} else
3313#endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
3314		tcon->unix_ext = 0; /* server does not support them */
3315
3316	/* do not care if a following call succeed - informational */
3317	if (!tcon->pipe && server->ops->qfs_tcon) {
3318		server->ops->qfs_tcon(mnt_ctx->xid, tcon, cifs_sb);
3319		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RO_CACHE) {
3320			if (tcon->fsDevInfo.DeviceCharacteristics &
3321			    cpu_to_le32(FILE_READ_ONLY_DEVICE))
3322				cifs_dbg(VFS, "mounted to read only share\n");
3323			else if ((cifs_sb->mnt_cifs_flags &
3324				  CIFS_MOUNT_RW_CACHE) == 0)
3325				cifs_dbg(VFS, "read only mount of RW share\n");
3326			/* no need to log a RW mount of a typical RW share */
3327		}
3328	}
3329
3330	/*
3331	 * Clamp the rsize/wsize mount arguments if they are too big for the server
3332	 * and set the rsize/wsize to the negotiated values if not passed in by
3333	 * the user on mount
3334	 */
3335	if ((cifs_sb->ctx->wsize == 0) ||
3336	    (cifs_sb->ctx->wsize > server->ops->negotiate_wsize(tcon, ctx)))
3337		cifs_sb->ctx->wsize = server->ops->negotiate_wsize(tcon, ctx);
3338	if ((cifs_sb->ctx->rsize == 0) ||
3339	    (cifs_sb->ctx->rsize > server->ops->negotiate_rsize(tcon, ctx)))
3340		cifs_sb->ctx->rsize = server->ops->negotiate_rsize(tcon, ctx);
3341
3342	/*
3343	 * The cookie is initialized from volume info returned above.
3344	 * Inside cifs_fscache_get_super_cookie it checks
3345	 * that we do not get super cookie twice.
3346	 */
3347	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_FSCACHE)
3348		cifs_fscache_get_super_cookie(tcon);
3349
3350out:
3351	mnt_ctx->tcon = tcon;
3352	return rc;
3353}
3354
3355static int mount_setup_tlink(struct cifs_sb_info *cifs_sb, struct cifs_ses *ses,
3356			     struct cifs_tcon *tcon)
3357{
3358	struct tcon_link *tlink;
3359
3360	/* hang the tcon off of the superblock */
3361	tlink = kzalloc(sizeof(*tlink), GFP_KERNEL);
3362	if (tlink == NULL)
3363		return -ENOMEM;
3364
3365	tlink->tl_uid = ses->linux_uid;
3366	tlink->tl_tcon = tcon;
3367	tlink->tl_time = jiffies;
3368	set_bit(TCON_LINK_MASTER, &tlink->tl_flags);
3369	set_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
3370
3371	cifs_sb->master_tlink = tlink;
3372	spin_lock(&cifs_sb->tlink_tree_lock);
3373	tlink_rb_insert(&cifs_sb->tlink_tree, tlink);
3374	spin_unlock(&cifs_sb->tlink_tree_lock);
3375
3376	queue_delayed_work(cifsiod_wq, &cifs_sb->prune_tlinks,
3377				TLINK_IDLE_EXPIRE);
3378	return 0;
3379}
3380
3381static int
3382cifs_are_all_path_components_accessible(struct TCP_Server_Info *server,
3383					unsigned int xid,
3384					struct cifs_tcon *tcon,
3385					struct cifs_sb_info *cifs_sb,
3386					char *full_path,
3387					int added_treename)
3388{
3389	int rc;
3390	char *s;
3391	char sep, tmp;
3392	int skip = added_treename ? 1 : 0;
3393
3394	sep = CIFS_DIR_SEP(cifs_sb);
3395	s = full_path;
3396
3397	rc = server->ops->is_path_accessible(xid, tcon, cifs_sb, "");
3398	while (rc == 0) {
3399		/* skip separators */
3400		while (*s == sep)
3401			s++;
3402		if (!*s)
3403			break;
3404		/* next separator */
3405		while (*s && *s != sep)
3406			s++;
3407		/*
3408		 * if the treename is added, we then have to skip the first
3409		 * part within the separators
3410		 */
3411		if (skip) {
3412			skip = 0;
3413			continue;
3414		}
3415		/*
3416		 * temporarily null-terminate the path at the end of
3417		 * the current component
3418		 */
3419		tmp = *s;
3420		*s = 0;
3421		rc = server->ops->is_path_accessible(xid, tcon, cifs_sb,
3422						     full_path);
3423		*s = tmp;
3424	}
3425	return rc;
3426}
3427
3428/*
3429 * Check if path is remote (i.e. a DFS share).
3430 *
3431 * Return -EREMOTE if it is, otherwise 0 or -errno.
3432 */
3433int cifs_is_path_remote(struct cifs_mount_ctx *mnt_ctx)
3434{
3435	int rc;
3436	struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3437	struct TCP_Server_Info *server = mnt_ctx->server;
3438	unsigned int xid = mnt_ctx->xid;
3439	struct cifs_tcon *tcon = mnt_ctx->tcon;
3440	struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
3441	char *full_path;
3442
3443	if (!server->ops->is_path_accessible)
3444		return -EOPNOTSUPP;
3445
3446	/*
3447	 * cifs_build_path_to_root works only when we have a valid tcon
3448	 */
3449	full_path = cifs_build_path_to_root(ctx, cifs_sb, tcon,
3450					    tcon->Flags & SMB_SHARE_IS_IN_DFS);
3451	if (full_path == NULL)
3452		return -ENOMEM;
3453
3454	cifs_dbg(FYI, "%s: full_path: %s\n", __func__, full_path);
3455
3456	rc = server->ops->is_path_accessible(xid, tcon, cifs_sb,
3457					     full_path);
3458	if (rc != 0 && rc != -EREMOTE)
3459		goto out;
3460
3461	if (rc != -EREMOTE) {
3462		rc = cifs_are_all_path_components_accessible(server, xid, tcon,
3463			cifs_sb, full_path, tcon->Flags & SMB_SHARE_IS_IN_DFS);
3464		if (rc != 0) {
3465			cifs_server_dbg(VFS, "cannot query dirs between root and final path, enabling CIFS_MOUNT_USE_PREFIX_PATH\n");
3466			cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
3467			rc = 0;
3468		}
3469	}
3470
3471out:
3472	kfree(full_path);
3473	return rc;
3474}
3475
3476#ifdef CONFIG_CIFS_DFS_UPCALL
3477int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
3478{
3479	struct cifs_mount_ctx mnt_ctx = { .cifs_sb = cifs_sb, .fs_ctx = ctx, };
3480	bool isdfs;
3481	int rc;
3482
3483	uuid_gen(&mnt_ctx.mount_id);
3484	rc = dfs_mount_share(&mnt_ctx, &isdfs);
3485	if (rc)
3486		goto error;
3487	if (!isdfs)
3488		goto out;
3489
3490	/*
3491	 * After reconnecting to a different server, unique ids won't match anymore, so we disable
3492	 * serverino. This prevents dentry revalidation to think the dentry are stale (ESTALE).
3493	 */
3494	cifs_autodisable_serverino(cifs_sb);
3495	/*
3496	 * Force the use of prefix path to support failover on DFS paths that resolve to targets
3497	 * that have different prefix paths.
3498	 */
3499	cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
3500	kfree(cifs_sb->prepath);
3501	cifs_sb->prepath = ctx->prepath;
3502	ctx->prepath = NULL;
3503	uuid_copy(&cifs_sb->dfs_mount_id, &mnt_ctx.mount_id);
3504
3505out:
3506	cifs_try_adding_channels(cifs_sb, mnt_ctx.ses);
3507	rc = mount_setup_tlink(cifs_sb, mnt_ctx.ses, mnt_ctx.tcon);
3508	if (rc)
3509		goto error;
3510
3511	free_xid(mnt_ctx.xid);
3512	return rc;
3513
3514error:
3515	dfs_cache_put_refsrv_sessions(&mnt_ctx.mount_id);
3516	kfree(mnt_ctx.origin_fullpath);
3517	kfree(mnt_ctx.leaf_fullpath);
3518	cifs_mount_put_conns(&mnt_ctx);
3519	return rc;
3520}
3521#else
3522int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
3523{
3524	int rc = 0;
3525	struct cifs_mount_ctx mnt_ctx = { .cifs_sb = cifs_sb, .fs_ctx = ctx, };
3526
3527	rc = cifs_mount_get_session(&mnt_ctx);
3528	if (rc)
3529		goto error;
3530
3531	rc = cifs_mount_get_tcon(&mnt_ctx);
3532	if (rc)
3533		goto error;
3534
3535	rc = cifs_is_path_remote(&mnt_ctx);
3536	if (rc == -EREMOTE)
3537		rc = -EOPNOTSUPP;
3538	if (rc)
3539		goto error;
3540
3541	rc = mount_setup_tlink(cifs_sb, mnt_ctx.ses, mnt_ctx.tcon);
3542	if (rc)
3543		goto error;
3544
3545	free_xid(mnt_ctx.xid);
3546	return rc;
3547
3548error:
3549	cifs_mount_put_conns(&mnt_ctx);
3550	return rc;
3551}
3552#endif
3553
3554/*
3555 * Issue a TREE_CONNECT request.
3556 */
3557int
3558CIFSTCon(const unsigned int xid, struct cifs_ses *ses,
3559	 const char *tree, struct cifs_tcon *tcon,
3560	 const struct nls_table *nls_codepage)
3561{
3562	struct smb_hdr *smb_buffer;
3563	struct smb_hdr *smb_buffer_response;
3564	TCONX_REQ *pSMB;
3565	TCONX_RSP *pSMBr;
3566	unsigned char *bcc_ptr;
3567	int rc = 0;
3568	int length;
3569	__u16 bytes_left, count;
3570
3571	if (ses == NULL)
3572		return -EIO;
3573
3574	smb_buffer = cifs_buf_get();
3575	if (smb_buffer == NULL)
3576		return -ENOMEM;
3577
3578	smb_buffer_response = smb_buffer;
3579
3580	header_assemble(smb_buffer, SMB_COM_TREE_CONNECT_ANDX,
3581			NULL /*no tid */ , 4 /*wct */ );
3582
3583	smb_buffer->Mid = get_next_mid(ses->server);
3584	smb_buffer->Uid = ses->Suid;
3585	pSMB = (TCONX_REQ *) smb_buffer;
3586	pSMBr = (TCONX_RSP *) smb_buffer_response;
3587
3588	pSMB->AndXCommand = 0xFF;
3589	pSMB->Flags = cpu_to_le16(TCON_EXTENDED_SECINFO);
3590	bcc_ptr = &pSMB->Password[0];
3591
3592	pSMB->PasswordLength = cpu_to_le16(1);	/* minimum */
3593	*bcc_ptr = 0; /* password is null byte */
3594	bcc_ptr++;              /* skip password */
3595	/* already aligned so no need to do it below */
3596
3597	if (ses->server->sign)
3598		smb_buffer->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
3599
3600	if (ses->capabilities & CAP_STATUS32) {
3601		smb_buffer->Flags2 |= SMBFLG2_ERR_STATUS;
3602	}
3603	if (ses->capabilities & CAP_DFS) {
3604		smb_buffer->Flags2 |= SMBFLG2_DFS;
3605	}
3606	if (ses->capabilities & CAP_UNICODE) {
3607		smb_buffer->Flags2 |= SMBFLG2_UNICODE;
3608		length =
3609		    cifs_strtoUTF16((__le16 *) bcc_ptr, tree,
3610			6 /* max utf8 char length in bytes */ *
3611			(/* server len*/ + 256 /* share len */), nls_codepage);
3612		bcc_ptr += 2 * length;	/* convert num 16 bit words to bytes */
3613		bcc_ptr += 2;	/* skip trailing null */
3614	} else {		/* ASCII */
3615		strcpy(bcc_ptr, tree);
3616		bcc_ptr += strlen(tree) + 1;
3617	}
3618	strcpy(bcc_ptr, "?????");
3619	bcc_ptr += strlen("?????");
3620	bcc_ptr += 1;
3621	count = bcc_ptr - &pSMB->Password[0];
3622	be32_add_cpu(&pSMB->hdr.smb_buf_length, count);
3623	pSMB->ByteCount = cpu_to_le16(count);
3624
3625	rc = SendReceive(xid, ses, smb_buffer, smb_buffer_response, &length,
3626			 0);
3627
3628	/* above now done in SendReceive */
3629	if (rc == 0) {
3630		bool is_unicode;
3631
3632		tcon->tid = smb_buffer_response->Tid;
3633		bcc_ptr = pByteArea(smb_buffer_response);
3634		bytes_left = get_bcc(smb_buffer_response);
3635		length = strnlen(bcc_ptr, bytes_left - 2);
3636		if (smb_buffer->Flags2 & SMBFLG2_UNICODE)
3637			is_unicode = true;
3638		else
3639			is_unicode = false;
3640
3641
3642		/* skip service field (NB: this field is always ASCII) */
3643		if (length == 3) {
3644			if ((bcc_ptr[0] == 'I') && (bcc_ptr[1] == 'P') &&
3645			    (bcc_ptr[2] == 'C')) {
3646				cifs_dbg(FYI, "IPC connection\n");
3647				tcon->ipc = true;
3648				tcon->pipe = true;
3649			}
3650		} else if (length == 2) {
3651			if ((bcc_ptr[0] == 'A') && (bcc_ptr[1] == ':')) {
3652				/* the most common case */
3653				cifs_dbg(FYI, "disk share connection\n");
3654			}
3655		}
3656		bcc_ptr += length + 1;
3657		bytes_left -= (length + 1);
3658		strscpy(tcon->tree_name, tree, sizeof(tcon->tree_name));
3659
3660		/* mostly informational -- no need to fail on error here */
3661		kfree(tcon->nativeFileSystem);
3662		tcon->nativeFileSystem = cifs_strndup_from_utf16(bcc_ptr,
3663						      bytes_left, is_unicode,
3664						      nls_codepage);
3665
3666		cifs_dbg(FYI, "nativeFileSystem=%s\n", tcon->nativeFileSystem);
3667
3668		if ((smb_buffer_response->WordCount == 3) ||
3669			 (smb_buffer_response->WordCount == 7))
3670			/* field is in same location */
3671			tcon->Flags = le16_to_cpu(pSMBr->OptionalSupport);
3672		else
3673			tcon->Flags = 0;
3674		cifs_dbg(FYI, "Tcon flags: 0x%x\n", tcon->Flags);
3675	}
3676
3677	cifs_buf_release(smb_buffer);
3678	return rc;
3679}
3680
3681static void delayed_free(struct rcu_head *p)
3682{
3683	struct cifs_sb_info *cifs_sb = container_of(p, struct cifs_sb_info, rcu);
3684
3685	unload_nls(cifs_sb->local_nls);
3686	smb3_cleanup_fs_context(cifs_sb->ctx);
3687	kfree(cifs_sb);
3688}
3689
3690void
3691cifs_umount(struct cifs_sb_info *cifs_sb)
3692{
3693	struct rb_root *root = &cifs_sb->tlink_tree;
3694	struct rb_node *node;
3695	struct tcon_link *tlink;
3696
3697	cancel_delayed_work_sync(&cifs_sb->prune_tlinks);
3698
3699	spin_lock(&cifs_sb->tlink_tree_lock);
3700	while ((node = rb_first(root))) {
3701		tlink = rb_entry(node, struct tcon_link, tl_rbnode);
3702		cifs_get_tlink(tlink);
3703		clear_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
3704		rb_erase(node, root);
3705
3706		spin_unlock(&cifs_sb->tlink_tree_lock);
3707		cifs_put_tlink(tlink);
3708		spin_lock(&cifs_sb->tlink_tree_lock);
3709	}
3710	spin_unlock(&cifs_sb->tlink_tree_lock);
3711
3712	kfree(cifs_sb->prepath);
3713#ifdef CONFIG_CIFS_DFS_UPCALL
3714	dfs_cache_put_refsrv_sessions(&cifs_sb->dfs_mount_id);
3715#endif
3716	call_rcu(&cifs_sb->rcu, delayed_free);
3717}
3718
3719int
3720cifs_negotiate_protocol(const unsigned int xid, struct cifs_ses *ses,
3721			struct TCP_Server_Info *server)
3722{
3723	int rc = 0;
3724
3725	if (!server->ops->need_neg || !server->ops->negotiate)
3726		return -ENOSYS;
3727
3728	/* only send once per connect */
3729	spin_lock(&server->srv_lock);
3730	if (!server->ops->need_neg(server) ||
3731	    server->tcpStatus != CifsNeedNegotiate) {
3732		spin_unlock(&server->srv_lock);
3733		return 0;
3734	}
3735	server->tcpStatus = CifsInNegotiate;
3736	spin_unlock(&server->srv_lock);
3737
3738	rc = server->ops->negotiate(xid, ses, server);
3739	if (rc == 0) {
3740		spin_lock(&server->srv_lock);
3741		if (server->tcpStatus == CifsInNegotiate)
3742			server->tcpStatus = CifsGood;
3743		else
3744			rc = -EHOSTDOWN;
3745		spin_unlock(&server->srv_lock);
3746	} else {
3747		spin_lock(&server->srv_lock);
3748		if (server->tcpStatus == CifsInNegotiate)
3749			server->tcpStatus = CifsNeedNegotiate;
3750		spin_unlock(&server->srv_lock);
3751	}
3752
3753	return rc;
3754}
3755
3756int
3757cifs_setup_session(const unsigned int xid, struct cifs_ses *ses,
3758		   struct TCP_Server_Info *server,
3759		   struct nls_table *nls_info)
3760{
3761	int rc = -ENOSYS;
3762	struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&server->dstaddr;
3763	struct sockaddr_in *addr = (struct sockaddr_in *)&server->dstaddr;
3764	bool is_binding = false;
3765
3766	spin_lock(&ses->ses_lock);
3767	if (server->dstaddr.ss_family == AF_INET6)
3768		scnprintf(ses->ip_addr, sizeof(ses->ip_addr), "%pI6", &addr6->sin6_addr);
3769	else
3770		scnprintf(ses->ip_addr, sizeof(ses->ip_addr), "%pI4", &addr->sin_addr);
3771
3772	if (ses->ses_status != SES_GOOD &&
3773	    ses->ses_status != SES_NEW &&
3774	    ses->ses_status != SES_NEED_RECON) {
3775		spin_unlock(&ses->ses_lock);
3776		return 0;
3777	}
3778
3779	/* only send once per connect */
3780	spin_lock(&ses->chan_lock);
3781	if (CIFS_ALL_CHANS_GOOD(ses) ||
3782	    cifs_chan_in_reconnect(ses, server)) {
3783		spin_unlock(&ses->chan_lock);
3784		spin_unlock(&ses->ses_lock);
3785		return 0;
3786	}
3787	is_binding = !CIFS_ALL_CHANS_NEED_RECONNECT(ses);
3788	cifs_chan_set_in_reconnect(ses, server);
3789	spin_unlock(&ses->chan_lock);
3790
3791	if (!is_binding)
3792		ses->ses_status = SES_IN_SETUP;
3793	spin_unlock(&ses->ses_lock);
3794
3795	if (!is_binding) {
3796		ses->capabilities = server->capabilities;
3797		if (!linuxExtEnabled)
3798			ses->capabilities &= (~server->vals->cap_unix);
3799
3800		if (ses->auth_key.response) {
3801			cifs_dbg(FYI, "Free previous auth_key.response = %p\n",
3802				 ses->auth_key.response);
3803			kfree_sensitive(ses->auth_key.response);
3804			ses->auth_key.response = NULL;
3805			ses->auth_key.len = 0;
3806		}
3807	}
3808
3809	cifs_dbg(FYI, "Security Mode: 0x%x Capabilities: 0x%x TimeAdjust: %d\n",
3810		 server->sec_mode, server->capabilities, server->timeAdj);
3811
3812	if (server->ops->sess_setup)
3813		rc = server->ops->sess_setup(xid, ses, server, nls_info);
3814
3815	if (rc) {
3816		cifs_server_dbg(VFS, "Send error in SessSetup = %d\n", rc);
3817		spin_lock(&ses->ses_lock);
3818		if (ses->ses_status == SES_IN_SETUP)
3819			ses->ses_status = SES_NEED_RECON;
3820		spin_lock(&ses->chan_lock);
3821		cifs_chan_clear_in_reconnect(ses, server);
3822		spin_unlock(&ses->chan_lock);
3823		spin_unlock(&ses->ses_lock);
3824	} else {
3825		spin_lock(&ses->ses_lock);
3826		if (ses->ses_status == SES_IN_SETUP)
3827			ses->ses_status = SES_GOOD;
3828		spin_lock(&ses->chan_lock);
3829		cifs_chan_clear_in_reconnect(ses, server);
3830		cifs_chan_clear_need_reconnect(ses, server);
3831		spin_unlock(&ses->chan_lock);
3832		spin_unlock(&ses->ses_lock);
3833	}
3834
3835	return rc;
3836}
3837
3838static int
3839cifs_set_vol_auth(struct smb3_fs_context *ctx, struct cifs_ses *ses)
3840{
3841	ctx->sectype = ses->sectype;
3842
3843	/* krb5 is special, since we don't need username or pw */
3844	if (ctx->sectype == Kerberos)
3845		return 0;
3846
3847	return cifs_set_cifscreds(ctx, ses);
3848}
3849
3850static struct cifs_tcon *
3851cifs_construct_tcon(struct cifs_sb_info *cifs_sb, kuid_t fsuid)
3852{
3853	int rc;
3854	struct cifs_tcon *master_tcon = cifs_sb_master_tcon(cifs_sb);
3855	struct cifs_ses *ses;
3856	struct cifs_tcon *tcon = NULL;
3857	struct smb3_fs_context *ctx;
3858
3859	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
3860	if (ctx == NULL)
3861		return ERR_PTR(-ENOMEM);
3862
3863	ctx->local_nls = cifs_sb->local_nls;
3864	ctx->linux_uid = fsuid;
3865	ctx->cred_uid = fsuid;
3866	ctx->UNC = master_tcon->tree_name;
3867	ctx->retry = master_tcon->retry;
3868	ctx->nocase = master_tcon->nocase;
3869	ctx->nohandlecache = master_tcon->nohandlecache;
3870	ctx->local_lease = master_tcon->local_lease;
3871	ctx->no_lease = master_tcon->no_lease;
3872	ctx->resilient = master_tcon->use_resilient;
3873	ctx->persistent = master_tcon->use_persistent;
3874	ctx->handle_timeout = master_tcon->handle_timeout;
3875	ctx->no_linux_ext = !master_tcon->unix_ext;
3876	ctx->linux_ext = master_tcon->posix_extensions;
3877	ctx->sectype = master_tcon->ses->sectype;
3878	ctx->sign = master_tcon->ses->sign;
3879	ctx->seal = master_tcon->seal;
3880	ctx->witness = master_tcon->use_witness;
3881
3882	rc = cifs_set_vol_auth(ctx, master_tcon->ses);
3883	if (rc) {
3884		tcon = ERR_PTR(rc);
3885		goto out;
3886	}
3887
3888	/* get a reference for the same TCP session */
3889	spin_lock(&cifs_tcp_ses_lock);
3890	++master_tcon->ses->server->srv_count;
3891	spin_unlock(&cifs_tcp_ses_lock);
3892
3893	ses = cifs_get_smb_ses(master_tcon->ses->server, ctx);
3894	if (IS_ERR(ses)) {
3895		tcon = (struct cifs_tcon *)ses;
3896		cifs_put_tcp_session(master_tcon->ses->server, 0);
3897		goto out;
3898	}
3899
3900	tcon = cifs_get_tcon(ses, ctx);
3901	if (IS_ERR(tcon)) {
3902		cifs_put_smb_ses(ses);
3903		goto out;
3904	}
3905
3906#ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
3907	if (cap_unix(ses))
3908		reset_cifs_unix_caps(0, tcon, NULL, ctx);
3909#endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
3910
3911out:
3912	kfree(ctx->username);
3913	kfree_sensitive(ctx->password);
3914	kfree(ctx);
3915
3916	return tcon;
3917}
3918
3919struct cifs_tcon *
3920cifs_sb_master_tcon(struct cifs_sb_info *cifs_sb)
3921{
3922	return tlink_tcon(cifs_sb_master_tlink(cifs_sb));
3923}
3924
3925/* find and return a tlink with given uid */
3926static struct tcon_link *
3927tlink_rb_search(struct rb_root *root, kuid_t uid)
3928{
3929	struct rb_node *node = root->rb_node;
3930	struct tcon_link *tlink;
3931
3932	while (node) {
3933		tlink = rb_entry(node, struct tcon_link, tl_rbnode);
3934
3935		if (uid_gt(tlink->tl_uid, uid))
3936			node = node->rb_left;
3937		else if (uid_lt(tlink->tl_uid, uid))
3938			node = node->rb_right;
3939		else
3940			return tlink;
3941	}
3942	return NULL;
3943}
3944
3945/* insert a tcon_link into the tree */
3946static void
3947tlink_rb_insert(struct rb_root *root, struct tcon_link *new_tlink)
3948{
3949	struct rb_node **new = &(root->rb_node), *parent = NULL;
3950	struct tcon_link *tlink;
3951
3952	while (*new) {
3953		tlink = rb_entry(*new, struct tcon_link, tl_rbnode);
3954		parent = *new;
3955
3956		if (uid_gt(tlink->tl_uid, new_tlink->tl_uid))
3957			new = &((*new)->rb_left);
3958		else
3959			new = &((*new)->rb_right);
3960	}
3961
3962	rb_link_node(&new_tlink->tl_rbnode, parent, new);
3963	rb_insert_color(&new_tlink->tl_rbnode, root);
3964}
3965
3966/*
3967 * Find or construct an appropriate tcon given a cifs_sb and the fsuid of the
3968 * current task.
3969 *
3970 * If the superblock doesn't refer to a multiuser mount, then just return
3971 * the master tcon for the mount.
3972 *
3973 * First, search the rbtree for an existing tcon for this fsuid. If one
3974 * exists, then check to see if it's pending construction. If it is then wait
3975 * for construction to complete. Once it's no longer pending, check to see if
3976 * it failed and either return an error or retry construction, depending on
3977 * the timeout.
3978 *
3979 * If one doesn't exist then insert a new tcon_link struct into the tree and
3980 * try to construct a new one.
3981 */
3982struct tcon_link *
3983cifs_sb_tlink(struct cifs_sb_info *cifs_sb)
3984{
3985	int ret;
3986	kuid_t fsuid = current_fsuid();
3987	struct tcon_link *tlink, *newtlink;
3988
3989	if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER))
3990		return cifs_get_tlink(cifs_sb_master_tlink(cifs_sb));
3991
3992	spin_lock(&cifs_sb->tlink_tree_lock);
3993	tlink = tlink_rb_search(&cifs_sb->tlink_tree, fsuid);
3994	if (tlink)
3995		cifs_get_tlink(tlink);
3996	spin_unlock(&cifs_sb->tlink_tree_lock);
3997
3998	if (tlink == NULL) {
3999		newtlink = kzalloc(sizeof(*tlink), GFP_KERNEL);
4000		if (newtlink == NULL)
4001			return ERR_PTR(-ENOMEM);
4002		newtlink->tl_uid = fsuid;
4003		newtlink->tl_tcon = ERR_PTR(-EACCES);
4004		set_bit(TCON_LINK_PENDING, &newtlink->tl_flags);
4005		set_bit(TCON_LINK_IN_TREE, &newtlink->tl_flags);
4006		cifs_get_tlink(newtlink);
4007
4008		spin_lock(&cifs_sb->tlink_tree_lock);
4009		/* was one inserted after previous search? */
4010		tlink = tlink_rb_search(&cifs_sb->tlink_tree, fsuid);
4011		if (tlink) {
4012			cifs_get_tlink(tlink);
4013			spin_unlock(&cifs_sb->tlink_tree_lock);
4014			kfree(newtlink);
4015			goto wait_for_construction;
4016		}
4017		tlink = newtlink;
4018		tlink_rb_insert(&cifs_sb->tlink_tree, tlink);
4019		spin_unlock(&cifs_sb->tlink_tree_lock);
4020	} else {
4021wait_for_construction:
4022		ret = wait_on_bit(&tlink->tl_flags, TCON_LINK_PENDING,
4023				  TASK_INTERRUPTIBLE);
4024		if (ret) {
4025			cifs_put_tlink(tlink);
4026			return ERR_PTR(-ERESTARTSYS);
4027		}
4028
4029		/* if it's good, return it */
4030		if (!IS_ERR(tlink->tl_tcon))
4031			return tlink;
4032
4033		/* return error if we tried this already recently */
4034		if (time_before(jiffies, tlink->tl_time + TLINK_ERROR_EXPIRE)) {
4035			cifs_put_tlink(tlink);
4036			return ERR_PTR(-EACCES);
4037		}
4038
4039		if (test_and_set_bit(TCON_LINK_PENDING, &tlink->tl_flags))
4040			goto wait_for_construction;
4041	}
4042
4043	tlink->tl_tcon = cifs_construct_tcon(cifs_sb, fsuid);
4044	clear_bit(TCON_LINK_PENDING, &tlink->tl_flags);
4045	wake_up_bit(&tlink->tl_flags, TCON_LINK_PENDING);
4046
4047	if (IS_ERR(tlink->tl_tcon)) {
4048		cifs_put_tlink(tlink);
4049		return ERR_PTR(-EACCES);
4050	}
4051
4052	return tlink;
4053}
4054
4055/*
4056 * periodic workqueue job that scans tcon_tree for a superblock and closes
4057 * out tcons.
4058 */
4059static void
4060cifs_prune_tlinks(struct work_struct *work)
4061{
4062	struct cifs_sb_info *cifs_sb = container_of(work, struct cifs_sb_info,
4063						    prune_tlinks.work);
4064	struct rb_root *root = &cifs_sb->tlink_tree;
4065	struct rb_node *node;
4066	struct rb_node *tmp;
4067	struct tcon_link *tlink;
4068
4069	/*
4070	 * Because we drop the spinlock in the loop in order to put the tlink
4071	 * it's not guarded against removal of links from the tree. The only
4072	 * places that remove entries from the tree are this function and
4073	 * umounts. Because this function is non-reentrant and is canceled
4074	 * before umount can proceed, this is safe.
4075	 */
4076	spin_lock(&cifs_sb->tlink_tree_lock);
4077	node = rb_first(root);
4078	while (node != NULL) {
4079		tmp = node;
4080		node = rb_next(tmp);
4081		tlink = rb_entry(tmp, struct tcon_link, tl_rbnode);
4082
4083		if (test_bit(TCON_LINK_MASTER, &tlink->tl_flags) ||
4084		    atomic_read(&tlink->tl_count) != 0 ||
4085		    time_after(tlink->tl_time + TLINK_IDLE_EXPIRE, jiffies))
4086			continue;
4087
4088		cifs_get_tlink(tlink);
4089		clear_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
4090		rb_erase(tmp, root);
4091
4092		spin_unlock(&cifs_sb->tlink_tree_lock);
4093		cifs_put_tlink(tlink);
4094		spin_lock(&cifs_sb->tlink_tree_lock);
4095	}
4096	spin_unlock(&cifs_sb->tlink_tree_lock);
4097
4098	queue_delayed_work(cifsiod_wq, &cifs_sb->prune_tlinks,
4099				TLINK_IDLE_EXPIRE);
4100}
4101
4102#ifndef CONFIG_CIFS_DFS_UPCALL
4103int cifs_tree_connect(const unsigned int xid, struct cifs_tcon *tcon, const struct nls_table *nlsc)
4104{
4105	int rc;
4106	const struct smb_version_operations *ops = tcon->ses->server->ops;
4107
4108	/* only send once per connect */
4109	spin_lock(&tcon->tc_lock);
4110	if (tcon->ses->ses_status != SES_GOOD ||
4111	    (tcon->status != TID_NEW &&
4112	    tcon->status != TID_NEED_TCON)) {
4113		spin_unlock(&tcon->tc_lock);
4114		return 0;
4115	}
4116	tcon->status = TID_IN_TCON;
4117	spin_unlock(&tcon->tc_lock);
4118
4119	rc = ops->tree_connect(xid, tcon->ses, tcon->tree_name, tcon, nlsc);
4120	if (rc) {
4121		spin_lock(&tcon->tc_lock);
4122		if (tcon->status == TID_IN_TCON)
4123			tcon->status = TID_NEED_TCON;
4124		spin_unlock(&tcon->tc_lock);
4125	} else {
4126		spin_lock(&tcon->tc_lock);
4127		if (tcon->status == TID_IN_TCON)
4128			tcon->status = TID_GOOD;
4129		tcon->need_reconnect = false;
4130		spin_unlock(&tcon->tc_lock);
4131	}
4132
4133	return rc;
4134}
4135#endif