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1 // SPDX-License-Identifier: LGPL-2.1
2 /*
3  *
4  *   SMB/CIFS session setup handling routines
5  *
6  *   Copyright (c) International Business Machines  Corp., 2006, 2009
7  *   Author(s): Steve French (sfrench@us.ibm.com)
8  *
9  */
10 
11 #include "cifspdu.h"
12 #include "cifsglob.h"
13 #include "cifsproto.h"
14 #include "cifs_unicode.h"
15 #include "cifs_debug.h"
16 #include "ntlmssp.h"
17 #include "nterr.h"
18 #include <linux/utsname.h>
19 #include <linux/slab.h>
20 #include <linux/version.h>
21 #include "cifsfs.h"
22 #include "cifs_spnego.h"
23 #include "smb2proto.h"
24 #include "fs_context.h"
25 
26 static int
27 cifs_ses_add_channel(struct cifs_ses *ses,
28 		     struct cifs_server_iface *iface);
29 
30 bool
is_server_using_iface(struct TCP_Server_Info * server,struct cifs_server_iface * iface)31 is_server_using_iface(struct TCP_Server_Info *server,
32 		      struct cifs_server_iface *iface)
33 {
34 	struct sockaddr_in *i4 = (struct sockaddr_in *)&iface->sockaddr;
35 	struct sockaddr_in6 *i6 = (struct sockaddr_in6 *)&iface->sockaddr;
36 	struct sockaddr_in *s4 = (struct sockaddr_in *)&server->dstaddr;
37 	struct sockaddr_in6 *s6 = (struct sockaddr_in6 *)&server->dstaddr;
38 
39 	if (server->dstaddr.ss_family != iface->sockaddr.ss_family)
40 		return false;
41 	if (server->dstaddr.ss_family == AF_INET) {
42 		if (s4->sin_addr.s_addr != i4->sin_addr.s_addr)
43 			return false;
44 	} else if (server->dstaddr.ss_family == AF_INET6) {
45 		if (memcmp(&s6->sin6_addr, &i6->sin6_addr,
46 			   sizeof(i6->sin6_addr)) != 0)
47 			return false;
48 	} else {
49 		/* unknown family.. */
50 		return false;
51 	}
52 	return true;
53 }
54 
is_ses_using_iface(struct cifs_ses * ses,struct cifs_server_iface * iface)55 bool is_ses_using_iface(struct cifs_ses *ses, struct cifs_server_iface *iface)
56 {
57 	int i;
58 
59 	spin_lock(&ses->chan_lock);
60 	for (i = 0; i < ses->chan_count; i++) {
61 		if (ses->chans[i].iface == iface) {
62 			spin_unlock(&ses->chan_lock);
63 			return true;
64 		}
65 	}
66 	spin_unlock(&ses->chan_lock);
67 	return false;
68 }
69 
70 /* channel helper functions. assumed that chan_lock is held by caller. */
71 
72 int
cifs_ses_get_chan_index(struct cifs_ses * ses,struct TCP_Server_Info * server)73 cifs_ses_get_chan_index(struct cifs_ses *ses,
74 			struct TCP_Server_Info *server)
75 {
76 	unsigned int i;
77 
78 	/* if the channel is waiting for termination */
79 	if (server && server->terminate)
80 		return CIFS_INVAL_CHAN_INDEX;
81 
82 	for (i = 0; i < ses->chan_count; i++) {
83 		if (ses->chans[i].server == server)
84 			return i;
85 	}
86 
87 	/* If we didn't find the channel, it is likely a bug */
88 	if (server)
89 		cifs_dbg(VFS, "unable to get chan index for server: 0x%llx",
90 			 server->conn_id);
91 	return CIFS_INVAL_CHAN_INDEX;
92 }
93 
94 void
cifs_chan_set_in_reconnect(struct cifs_ses * ses,struct TCP_Server_Info * server)95 cifs_chan_set_in_reconnect(struct cifs_ses *ses,
96 			     struct TCP_Server_Info *server)
97 {
98 	int chan_index = cifs_ses_get_chan_index(ses, server);
99 
100 	if (chan_index == CIFS_INVAL_CHAN_INDEX)
101 		return;
102 
103 	ses->chans[chan_index].in_reconnect = true;
104 }
105 
106 void
cifs_chan_clear_in_reconnect(struct cifs_ses * ses,struct TCP_Server_Info * server)107 cifs_chan_clear_in_reconnect(struct cifs_ses *ses,
108 			     struct TCP_Server_Info *server)
109 {
110 	unsigned int chan_index = cifs_ses_get_chan_index(ses, server);
111 
112 	if (chan_index == CIFS_INVAL_CHAN_INDEX)
113 		return;
114 
115 	ses->chans[chan_index].in_reconnect = false;
116 }
117 
118 bool
cifs_chan_in_reconnect(struct cifs_ses * ses,struct TCP_Server_Info * server)119 cifs_chan_in_reconnect(struct cifs_ses *ses,
120 			  struct TCP_Server_Info *server)
121 {
122 	unsigned int chan_index = cifs_ses_get_chan_index(ses, server);
123 
124 	if (chan_index == CIFS_INVAL_CHAN_INDEX)
125 		return true;	/* err on the safer side */
126 
127 	return CIFS_CHAN_IN_RECONNECT(ses, chan_index);
128 }
129 
130 void
cifs_chan_set_need_reconnect(struct cifs_ses * ses,struct TCP_Server_Info * server)131 cifs_chan_set_need_reconnect(struct cifs_ses *ses,
132 			     struct TCP_Server_Info *server)
133 {
134 	unsigned int chan_index = cifs_ses_get_chan_index(ses, server);
135 
136 	if (chan_index == CIFS_INVAL_CHAN_INDEX)
137 		return;
138 
139 	set_bit(chan_index, &ses->chans_need_reconnect);
140 	cifs_dbg(FYI, "Set reconnect bitmask for chan %u; now 0x%lx\n",
141 		 chan_index, ses->chans_need_reconnect);
142 }
143 
144 void
cifs_chan_clear_need_reconnect(struct cifs_ses * ses,struct TCP_Server_Info * server)145 cifs_chan_clear_need_reconnect(struct cifs_ses *ses,
146 			       struct TCP_Server_Info *server)
147 {
148 	unsigned int chan_index = cifs_ses_get_chan_index(ses, server);
149 
150 	if (chan_index == CIFS_INVAL_CHAN_INDEX)
151 		return;
152 
153 	clear_bit(chan_index, &ses->chans_need_reconnect);
154 	cifs_dbg(FYI, "Cleared reconnect bitmask for chan %u; now 0x%lx\n",
155 		 chan_index, ses->chans_need_reconnect);
156 }
157 
158 bool
cifs_chan_needs_reconnect(struct cifs_ses * ses,struct TCP_Server_Info * server)159 cifs_chan_needs_reconnect(struct cifs_ses *ses,
160 			  struct TCP_Server_Info *server)
161 {
162 	unsigned int chan_index = cifs_ses_get_chan_index(ses, server);
163 
164 	if (chan_index == CIFS_INVAL_CHAN_INDEX)
165 		return true;	/* err on the safer side */
166 
167 	return CIFS_CHAN_NEEDS_RECONNECT(ses, chan_index);
168 }
169 
170 bool
cifs_chan_is_iface_active(struct cifs_ses * ses,struct TCP_Server_Info * server)171 cifs_chan_is_iface_active(struct cifs_ses *ses,
172 			  struct TCP_Server_Info *server)
173 {
174 	unsigned int chan_index = cifs_ses_get_chan_index(ses, server);
175 
176 	if (chan_index == CIFS_INVAL_CHAN_INDEX)
177 		return true;	/* err on the safer side */
178 
179 	return ses->chans[chan_index].iface &&
180 		ses->chans[chan_index].iface->is_active;
181 }
182 
183 /* returns number of channels added */
cifs_try_adding_channels(struct cifs_ses * ses)184 int cifs_try_adding_channels(struct cifs_ses *ses)
185 {
186 	struct TCP_Server_Info *server = ses->server;
187 	int old_chan_count, new_chan_count;
188 	int left;
189 	int rc = 0;
190 	int tries = 0;
191 	size_t iface_weight = 0, iface_min_speed = 0;
192 	struct cifs_server_iface *iface = NULL, *niface = NULL;
193 	struct cifs_server_iface *last_iface = NULL;
194 
195 	spin_lock(&ses->chan_lock);
196 
197 	new_chan_count = old_chan_count = ses->chan_count;
198 	left = ses->chan_max - ses->chan_count;
199 
200 	if (left <= 0) {
201 		spin_unlock(&ses->chan_lock);
202 		cifs_dbg(FYI,
203 			 "ses already at max_channels (%zu), nothing to open\n",
204 			 ses->chan_max);
205 		return 0;
206 	}
207 
208 	if (server->dialect < SMB30_PROT_ID) {
209 		spin_unlock(&ses->chan_lock);
210 		cifs_dbg(VFS, "multichannel is not supported on this protocol version, use 3.0 or above\n");
211 		return 0;
212 	}
213 
214 	if (!(server->capabilities & SMB2_GLOBAL_CAP_MULTI_CHANNEL)) {
215 		spin_unlock(&ses->chan_lock);
216 		cifs_server_dbg(VFS, "no multichannel support\n");
217 		return 0;
218 	}
219 	spin_unlock(&ses->chan_lock);
220 
221 	while (left > 0) {
222 
223 		tries++;
224 		if (tries > 3*ses->chan_max) {
225 			cifs_dbg(VFS, "too many channel open attempts (%d channels left to open)\n",
226 				 left);
227 			break;
228 		}
229 
230 		spin_lock(&ses->iface_lock);
231 		if (!ses->iface_count) {
232 			spin_unlock(&ses->iface_lock);
233 			cifs_dbg(ONCE, "server %s does not advertise interfaces\n",
234 				      ses->server->hostname);
235 			break;
236 		}
237 
238 		if (!iface)
239 			iface = list_first_entry(&ses->iface_list, struct cifs_server_iface,
240 						 iface_head);
241 		last_iface = list_last_entry(&ses->iface_list, struct cifs_server_iface,
242 					     iface_head);
243 		iface_min_speed = last_iface->speed;
244 
245 		list_for_each_entry_safe_from(iface, niface, &ses->iface_list,
246 				    iface_head) {
247 			/* do not mix rdma and non-rdma interfaces */
248 			if (iface->rdma_capable != ses->server->rdma)
249 				continue;
250 
251 			/* skip ifaces that are unusable */
252 			if (!iface->is_active ||
253 			    (is_ses_using_iface(ses, iface) &&
254 			     !iface->rss_capable))
255 				continue;
256 
257 			/* check if we already allocated enough channels */
258 			iface_weight = iface->speed / iface_min_speed;
259 
260 			if (iface->weight_fulfilled >= iface_weight)
261 				continue;
262 
263 			/* take ref before unlock */
264 			kref_get(&iface->refcount);
265 
266 			spin_unlock(&ses->iface_lock);
267 			rc = cifs_ses_add_channel(ses, iface);
268 			spin_lock(&ses->iface_lock);
269 
270 			if (rc) {
271 				cifs_dbg(VFS, "failed to open extra channel on iface:%pIS rc=%d\n",
272 					 &iface->sockaddr,
273 					 rc);
274 				kref_put(&iface->refcount, release_iface);
275 				/* failure to add chan should increase weight */
276 				iface->weight_fulfilled++;
277 				continue;
278 			}
279 
280 			iface->num_channels++;
281 			iface->weight_fulfilled++;
282 			cifs_dbg(VFS, "successfully opened new channel on iface:%pIS\n",
283 				 &iface->sockaddr);
284 			break;
285 		}
286 
287 		/* reached end of list. reset weight_fulfilled and start over */
288 		if (list_entry_is_head(iface, &ses->iface_list, iface_head)) {
289 			list_for_each_entry(iface, &ses->iface_list, iface_head)
290 				iface->weight_fulfilled = 0;
291 			spin_unlock(&ses->iface_lock);
292 			iface = NULL;
293 			continue;
294 		}
295 		spin_unlock(&ses->iface_lock);
296 
297 		left--;
298 		new_chan_count++;
299 	}
300 
301 	return new_chan_count - old_chan_count;
302 }
303 
304 /*
305  * called when multichannel is disabled by the server.
306  * this always gets called from smb2_reconnect
307  * and cannot get called in parallel threads.
308  */
309 void
cifs_disable_secondary_channels(struct cifs_ses * ses)310 cifs_disable_secondary_channels(struct cifs_ses *ses)
311 {
312 	int i, chan_count;
313 	struct TCP_Server_Info *server;
314 	struct cifs_server_iface *iface;
315 
316 	spin_lock(&ses->chan_lock);
317 	chan_count = ses->chan_count;
318 	if (chan_count == 1)
319 		goto done;
320 
321 	ses->chan_count = 1;
322 
323 	/* for all secondary channels reset the need reconnect bit */
324 	ses->chans_need_reconnect &= 1;
325 
326 	for (i = 1; i < chan_count; i++) {
327 		iface = ses->chans[i].iface;
328 		server = ses->chans[i].server;
329 
330 		/*
331 		 * remove these references first, since we need to unlock
332 		 * the chan_lock here, since iface_lock is a higher lock
333 		 */
334 		ses->chans[i].iface = NULL;
335 		ses->chans[i].server = NULL;
336 		spin_unlock(&ses->chan_lock);
337 
338 		if (iface) {
339 			spin_lock(&ses->iface_lock);
340 			iface->num_channels--;
341 			if (iface->weight_fulfilled)
342 				iface->weight_fulfilled--;
343 			kref_put(&iface->refcount, release_iface);
344 			spin_unlock(&ses->iface_lock);
345 		}
346 
347 		if (server) {
348 			if (!server->terminate) {
349 				server->terminate = true;
350 				cifs_signal_cifsd_for_reconnect(server, false);
351 			}
352 			cifs_put_tcp_session(server, false);
353 		}
354 
355 		spin_lock(&ses->chan_lock);
356 	}
357 
358 done:
359 	spin_unlock(&ses->chan_lock);
360 }
361 
362 /*
363  * update the iface for the channel if necessary.
364  * Must be called with chan_lock held.
365  */
366 void
cifs_chan_update_iface(struct cifs_ses * ses,struct TCP_Server_Info * server)367 cifs_chan_update_iface(struct cifs_ses *ses, struct TCP_Server_Info *server)
368 {
369 	unsigned int chan_index;
370 	size_t iface_weight = 0, iface_min_speed = 0;
371 	struct cifs_server_iface *iface = NULL;
372 	struct cifs_server_iface *old_iface = NULL;
373 	struct cifs_server_iface *last_iface = NULL;
374 	struct sockaddr_storage ss;
375 
376 	spin_lock(&ses->chan_lock);
377 	chan_index = cifs_ses_get_chan_index(ses, server);
378 	if (chan_index == CIFS_INVAL_CHAN_INDEX) {
379 		spin_unlock(&ses->chan_lock);
380 		return;
381 	}
382 
383 	if (ses->chans[chan_index].iface) {
384 		old_iface = ses->chans[chan_index].iface;
385 		if (old_iface->is_active) {
386 			spin_unlock(&ses->chan_lock);
387 			return;
388 		}
389 	}
390 	spin_unlock(&ses->chan_lock);
391 
392 	spin_lock(&server->srv_lock);
393 	ss = server->dstaddr;
394 	spin_unlock(&server->srv_lock);
395 
396 	spin_lock(&ses->iface_lock);
397 	if (!ses->iface_count) {
398 		spin_unlock(&ses->iface_lock);
399 		cifs_dbg(ONCE, "server %s does not advertise interfaces\n", ses->server->hostname);
400 		return;
401 	}
402 
403 	last_iface = list_last_entry(&ses->iface_list, struct cifs_server_iface,
404 				     iface_head);
405 	iface_min_speed = last_iface->speed;
406 
407 	/* then look for a new one */
408 	list_for_each_entry(iface, &ses->iface_list, iface_head) {
409 		if (!chan_index) {
410 			/* if we're trying to get the updated iface for primary channel */
411 			if (!cifs_match_ipaddr((struct sockaddr *) &ss,
412 					       (struct sockaddr *) &iface->sockaddr))
413 				continue;
414 
415 			kref_get(&iface->refcount);
416 			break;
417 		}
418 
419 		/* do not mix rdma and non-rdma interfaces */
420 		if (iface->rdma_capable != server->rdma)
421 			continue;
422 
423 		if (!iface->is_active ||
424 		    (is_ses_using_iface(ses, iface) &&
425 		     !iface->rss_capable)) {
426 			continue;
427 		}
428 
429 		/* check if we already allocated enough channels */
430 		iface_weight = iface->speed / iface_min_speed;
431 
432 		if (iface->weight_fulfilled >= iface_weight)
433 			continue;
434 
435 		kref_get(&iface->refcount);
436 		break;
437 	}
438 
439 	if (list_entry_is_head(iface, &ses->iface_list, iface_head)) {
440 		iface = NULL;
441 		cifs_dbg(FYI, "unable to find a suitable iface\n");
442 	}
443 
444 	if (!iface) {
445 		if (!chan_index)
446 			cifs_dbg(FYI, "unable to get the interface matching: %pIS\n",
447 				 &ss);
448 		else {
449 			cifs_dbg(FYI, "unable to find another interface to replace: %pIS\n",
450 				 &old_iface->sockaddr);
451 		}
452 
453 		spin_unlock(&ses->iface_lock);
454 		return;
455 	}
456 
457 	/* now drop the ref to the current iface */
458 	if (old_iface) {
459 		cifs_dbg(FYI, "replacing iface: %pIS with %pIS\n",
460 			 &old_iface->sockaddr,
461 			 &iface->sockaddr);
462 
463 		old_iface->num_channels--;
464 		if (old_iface->weight_fulfilled)
465 			old_iface->weight_fulfilled--;
466 		iface->num_channels++;
467 		iface->weight_fulfilled++;
468 
469 		kref_put(&old_iface->refcount, release_iface);
470 	} else if (!chan_index) {
471 		/* special case: update interface for primary channel */
472 		cifs_dbg(FYI, "referencing primary channel iface: %pIS\n",
473 			 &iface->sockaddr);
474 		iface->num_channels++;
475 		iface->weight_fulfilled++;
476 	}
477 	spin_unlock(&ses->iface_lock);
478 
479 	spin_lock(&ses->chan_lock);
480 	chan_index = cifs_ses_get_chan_index(ses, server);
481 	if (chan_index == CIFS_INVAL_CHAN_INDEX) {
482 		spin_unlock(&ses->chan_lock);
483 		return;
484 	}
485 
486 	ses->chans[chan_index].iface = iface;
487 	spin_unlock(&ses->chan_lock);
488 }
489 
490 /*
491  * If server is a channel of ses, return the corresponding enclosing
492  * cifs_chan otherwise return NULL.
493  */
494 struct cifs_chan *
cifs_ses_find_chan(struct cifs_ses * ses,struct TCP_Server_Info * server)495 cifs_ses_find_chan(struct cifs_ses *ses, struct TCP_Server_Info *server)
496 {
497 	int i;
498 
499 	spin_lock(&ses->chan_lock);
500 	for (i = 0; i < ses->chan_count; i++) {
501 		if (ses->chans[i].server == server) {
502 			spin_unlock(&ses->chan_lock);
503 			return &ses->chans[i];
504 		}
505 	}
506 	spin_unlock(&ses->chan_lock);
507 	return NULL;
508 }
509 
510 static int
cifs_ses_add_channel(struct cifs_ses * ses,struct cifs_server_iface * iface)511 cifs_ses_add_channel(struct cifs_ses *ses,
512 		     struct cifs_server_iface *iface)
513 {
514 	struct TCP_Server_Info *chan_server;
515 	struct cifs_chan *chan;
516 	struct smb3_fs_context *ctx;
517 	static const char unc_fmt[] = "\\%s\\foo";
518 	struct sockaddr_in *ipv4 = (struct sockaddr_in *)&iface->sockaddr;
519 	struct sockaddr_in6 *ipv6 = (struct sockaddr_in6 *)&iface->sockaddr;
520 	size_t len;
521 	int rc;
522 	unsigned int xid = get_xid();
523 
524 	if (iface->sockaddr.ss_family == AF_INET)
525 		cifs_dbg(FYI, "adding channel to ses %p (speed:%zu bps rdma:%s ip:%pI4)\n",
526 			 ses, iface->speed, iface->rdma_capable ? "yes" : "no",
527 			 &ipv4->sin_addr);
528 	else
529 		cifs_dbg(FYI, "adding channel to ses %p (speed:%zu bps rdma:%s ip:%pI6)\n",
530 			 ses, iface->speed, iface->rdma_capable ? "yes" : "no",
531 			 &ipv6->sin6_addr);
532 
533 	/*
534 	 * Setup a ctx with mostly the same info as the existing
535 	 * session and overwrite it with the requested iface data.
536 	 *
537 	 * We need to setup at least the fields used for negprot and
538 	 * sesssetup.
539 	 *
540 	 * We only need the ctx here, so we can reuse memory from
541 	 * the session and server without caring about memory
542 	 * management.
543 	 */
544 	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
545 	if (!ctx) {
546 		rc = -ENOMEM;
547 		goto out_free_xid;
548 	}
549 
550 	/* Always make new connection for now (TODO?) */
551 	ctx->nosharesock = true;
552 
553 	/* Auth */
554 	ctx->domainauto = ses->domainAuto;
555 	ctx->domainname = ses->domainName;
556 
557 	/* no hostname for extra channels */
558 	ctx->server_hostname = "";
559 
560 	ctx->username = ses->user_name;
561 	ctx->password = ses->password;
562 	ctx->sectype = ses->sectype;
563 	ctx->sign = ses->sign;
564 
565 	/* UNC and paths */
566 	/* XXX: Use ses->server->hostname? */
567 	len = sizeof(unc_fmt) + SERVER_NAME_LEN_WITH_NULL;
568 	ctx->UNC = kzalloc(len, GFP_KERNEL);
569 	if (!ctx->UNC) {
570 		rc = -ENOMEM;
571 		goto out_free_ctx;
572 	}
573 	scnprintf(ctx->UNC, len, unc_fmt, ses->ip_addr);
574 	ctx->prepath = "";
575 
576 	/* Reuse same version as master connection */
577 	ctx->vals = ses->server->vals;
578 	ctx->ops = ses->server->ops;
579 
580 	ctx->noblocksnd = ses->server->noblocksnd;
581 	ctx->noautotune = ses->server->noautotune;
582 	ctx->sockopt_tcp_nodelay = ses->server->tcp_nodelay;
583 	ctx->echo_interval = ses->server->echo_interval / HZ;
584 	ctx->max_credits = ses->server->max_credits;
585 
586 	/*
587 	 * This will be used for encoding/decoding user/domain/pw
588 	 * during sess setup auth.
589 	 */
590 	ctx->local_nls = ses->local_nls;
591 
592 	/* Use RDMA if possible */
593 	ctx->rdma = iface->rdma_capable;
594 	memcpy(&ctx->dstaddr, &iface->sockaddr, sizeof(ctx->dstaddr));
595 
596 	/* reuse master con client guid */
597 	memcpy(&ctx->client_guid, ses->server->client_guid,
598 	       sizeof(ctx->client_guid));
599 	ctx->use_client_guid = true;
600 
601 	chan_server = cifs_get_tcp_session(ctx, ses->server);
602 
603 	spin_lock(&ses->chan_lock);
604 	chan = &ses->chans[ses->chan_count];
605 	chan->server = chan_server;
606 	if (IS_ERR(chan->server)) {
607 		rc = PTR_ERR(chan->server);
608 		chan->server = NULL;
609 		spin_unlock(&ses->chan_lock);
610 		goto out;
611 	}
612 	chan->iface = iface;
613 	ses->chan_count++;
614 	atomic_set(&ses->chan_seq, 0);
615 
616 	/* Mark this channel as needing connect/setup */
617 	cifs_chan_set_need_reconnect(ses, chan->server);
618 
619 	spin_unlock(&ses->chan_lock);
620 
621 	mutex_lock(&ses->session_mutex);
622 	/*
623 	 * We need to allocate the server crypto now as we will need
624 	 * to sign packets before we generate the channel signing key
625 	 * (we sign with the session key)
626 	 */
627 	rc = smb311_crypto_shash_allocate(chan->server);
628 	if (rc) {
629 		cifs_dbg(VFS, "%s: crypto alloc failed\n", __func__);
630 		mutex_unlock(&ses->session_mutex);
631 		goto out;
632 	}
633 
634 	rc = cifs_negotiate_protocol(xid, ses, chan->server);
635 	if (!rc)
636 		rc = cifs_setup_session(xid, ses, chan->server, ses->local_nls);
637 
638 	mutex_unlock(&ses->session_mutex);
639 
640 out:
641 	if (rc && chan->server) {
642 		cifs_put_tcp_session(chan->server, 0);
643 
644 		spin_lock(&ses->chan_lock);
645 
646 		/* we rely on all bits beyond chan_count to be clear */
647 		cifs_chan_clear_need_reconnect(ses, chan->server);
648 		ses->chan_count--;
649 		/*
650 		 * chan_count should never reach 0 as at least the primary
651 		 * channel is always allocated
652 		 */
653 		WARN_ON(ses->chan_count < 1);
654 		spin_unlock(&ses->chan_lock);
655 	}
656 
657 	kfree(ctx->UNC);
658 out_free_ctx:
659 	kfree(ctx);
660 out_free_xid:
661 	free_xid(xid);
662 	return rc;
663 }
664 
665 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
cifs_ssetup_hdr(struct cifs_ses * ses,struct TCP_Server_Info * server,SESSION_SETUP_ANDX * pSMB)666 static __u32 cifs_ssetup_hdr(struct cifs_ses *ses,
667 			     struct TCP_Server_Info *server,
668 			     SESSION_SETUP_ANDX *pSMB)
669 {
670 	__u32 capabilities = 0;
671 
672 	/* init fields common to all four types of SessSetup */
673 	/* Note that offsets for first seven fields in req struct are same  */
674 	/*	in CIFS Specs so does not matter which of 3 forms of struct */
675 	/*	that we use in next few lines                               */
676 	/* Note that header is initialized to zero in header_assemble */
677 	pSMB->req.AndXCommand = 0xFF;
678 	pSMB->req.MaxBufferSize = cpu_to_le16(min_t(u32,
679 					CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4,
680 					USHRT_MAX));
681 	pSMB->req.MaxMpxCount = cpu_to_le16(server->maxReq);
682 	pSMB->req.VcNumber = cpu_to_le16(1);
683 
684 	/* Now no need to set SMBFLG_CASELESS or obsolete CANONICAL PATH */
685 
686 	/* BB verify whether signing required on neg or just auth frame (and NTLM case) */
687 
688 	capabilities = CAP_LARGE_FILES | CAP_NT_SMBS | CAP_LEVEL_II_OPLOCKS |
689 			CAP_LARGE_WRITE_X | CAP_LARGE_READ_X;
690 
691 	if (server->sign)
692 		pSMB->req.hdr.Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
693 
694 	if (ses->capabilities & CAP_UNICODE) {
695 		pSMB->req.hdr.Flags2 |= SMBFLG2_UNICODE;
696 		capabilities |= CAP_UNICODE;
697 	}
698 	if (ses->capabilities & CAP_STATUS32) {
699 		pSMB->req.hdr.Flags2 |= SMBFLG2_ERR_STATUS;
700 		capabilities |= CAP_STATUS32;
701 	}
702 	if (ses->capabilities & CAP_DFS) {
703 		pSMB->req.hdr.Flags2 |= SMBFLG2_DFS;
704 		capabilities |= CAP_DFS;
705 	}
706 	if (ses->capabilities & CAP_UNIX)
707 		capabilities |= CAP_UNIX;
708 
709 	return capabilities;
710 }
711 
712 static void
unicode_oslm_strings(char ** pbcc_area,const struct nls_table * nls_cp)713 unicode_oslm_strings(char **pbcc_area, const struct nls_table *nls_cp)
714 {
715 	char *bcc_ptr = *pbcc_area;
716 	int bytes_ret = 0;
717 
718 	/* Copy OS version */
719 	bytes_ret = cifs_strtoUTF16((__le16 *)bcc_ptr, "Linux version ", 32,
720 				    nls_cp);
721 	bcc_ptr += 2 * bytes_ret;
722 	bytes_ret = cifs_strtoUTF16((__le16 *) bcc_ptr, init_utsname()->release,
723 				    32, nls_cp);
724 	bcc_ptr += 2 * bytes_ret;
725 	bcc_ptr += 2; /* trailing null */
726 
727 	bytes_ret = cifs_strtoUTF16((__le16 *) bcc_ptr, CIFS_NETWORK_OPSYS,
728 				    32, nls_cp);
729 	bcc_ptr += 2 * bytes_ret;
730 	bcc_ptr += 2; /* trailing null */
731 
732 	*pbcc_area = bcc_ptr;
733 }
734 
unicode_domain_string(char ** pbcc_area,struct cifs_ses * ses,const struct nls_table * nls_cp)735 static void unicode_domain_string(char **pbcc_area, struct cifs_ses *ses,
736 				   const struct nls_table *nls_cp)
737 {
738 	char *bcc_ptr = *pbcc_area;
739 	int bytes_ret = 0;
740 
741 	/* copy domain */
742 	if (ses->domainName == NULL) {
743 		/*
744 		 * Sending null domain better than using a bogus domain name (as
745 		 * we did briefly in 2.6.18) since server will use its default
746 		 */
747 		*bcc_ptr = 0;
748 		*(bcc_ptr+1) = 0;
749 		bytes_ret = 0;
750 	} else
751 		bytes_ret = cifs_strtoUTF16((__le16 *) bcc_ptr, ses->domainName,
752 					    CIFS_MAX_DOMAINNAME_LEN, nls_cp);
753 	bcc_ptr += 2 * bytes_ret;
754 	bcc_ptr += 2;  /* account for null terminator */
755 
756 	*pbcc_area = bcc_ptr;
757 }
758 
unicode_ssetup_strings(char ** pbcc_area,struct cifs_ses * ses,const struct nls_table * nls_cp)759 static void unicode_ssetup_strings(char **pbcc_area, struct cifs_ses *ses,
760 				   const struct nls_table *nls_cp)
761 {
762 	char *bcc_ptr = *pbcc_area;
763 	int bytes_ret = 0;
764 
765 	/* BB FIXME add check that strings less than 335 or will need to send as arrays */
766 
767 	/* copy user */
768 	if (ses->user_name == NULL) {
769 		/* null user mount */
770 		*bcc_ptr = 0;
771 		*(bcc_ptr+1) = 0;
772 	} else {
773 		bytes_ret = cifs_strtoUTF16((__le16 *) bcc_ptr, ses->user_name,
774 					    CIFS_MAX_USERNAME_LEN, nls_cp);
775 	}
776 	bcc_ptr += 2 * bytes_ret;
777 	bcc_ptr += 2; /* account for null termination */
778 
779 	unicode_domain_string(&bcc_ptr, ses, nls_cp);
780 	unicode_oslm_strings(&bcc_ptr, nls_cp);
781 
782 	*pbcc_area = bcc_ptr;
783 }
784 
ascii_ssetup_strings(char ** pbcc_area,struct cifs_ses * ses,const struct nls_table * nls_cp)785 static void ascii_ssetup_strings(char **pbcc_area, struct cifs_ses *ses,
786 				 const struct nls_table *nls_cp)
787 {
788 	char *bcc_ptr = *pbcc_area;
789 	int len;
790 
791 	/* copy user */
792 	/* BB what about null user mounts - check that we do this BB */
793 	/* copy user */
794 	if (ses->user_name != NULL) {
795 		len = strscpy(bcc_ptr, ses->user_name, CIFS_MAX_USERNAME_LEN);
796 		if (WARN_ON_ONCE(len < 0))
797 			len = CIFS_MAX_USERNAME_LEN - 1;
798 		bcc_ptr += len;
799 	}
800 	/* else null user mount */
801 	*bcc_ptr = 0;
802 	bcc_ptr++; /* account for null termination */
803 
804 	/* copy domain */
805 	if (ses->domainName != NULL) {
806 		len = strscpy(bcc_ptr, ses->domainName, CIFS_MAX_DOMAINNAME_LEN);
807 		if (WARN_ON_ONCE(len < 0))
808 			len = CIFS_MAX_DOMAINNAME_LEN - 1;
809 		bcc_ptr += len;
810 	} /* else we send a null domain name so server will default to its own domain */
811 	*bcc_ptr = 0;
812 	bcc_ptr++;
813 
814 	/* BB check for overflow here */
815 
816 	strcpy(bcc_ptr, "Linux version ");
817 	bcc_ptr += strlen("Linux version ");
818 	strcpy(bcc_ptr, init_utsname()->release);
819 	bcc_ptr += strlen(init_utsname()->release) + 1;
820 
821 	strcpy(bcc_ptr, CIFS_NETWORK_OPSYS);
822 	bcc_ptr += strlen(CIFS_NETWORK_OPSYS) + 1;
823 
824 	*pbcc_area = bcc_ptr;
825 }
826 
827 static void
decode_unicode_ssetup(char ** pbcc_area,int bleft,struct cifs_ses * ses,const struct nls_table * nls_cp)828 decode_unicode_ssetup(char **pbcc_area, int bleft, struct cifs_ses *ses,
829 		      const struct nls_table *nls_cp)
830 {
831 	int len;
832 	char *data = *pbcc_area;
833 
834 	cifs_dbg(FYI, "bleft %d\n", bleft);
835 
836 	kfree(ses->serverOS);
837 	ses->serverOS = cifs_strndup_from_utf16(data, bleft, true, nls_cp);
838 	cifs_dbg(FYI, "serverOS=%s\n", ses->serverOS);
839 	len = (UniStrnlen((wchar_t *) data, bleft / 2) * 2) + 2;
840 	data += len;
841 	bleft -= len;
842 	if (bleft <= 0)
843 		return;
844 
845 	kfree(ses->serverNOS);
846 	ses->serverNOS = cifs_strndup_from_utf16(data, bleft, true, nls_cp);
847 	cifs_dbg(FYI, "serverNOS=%s\n", ses->serverNOS);
848 	len = (UniStrnlen((wchar_t *) data, bleft / 2) * 2) + 2;
849 	data += len;
850 	bleft -= len;
851 	if (bleft <= 0)
852 		return;
853 
854 	kfree(ses->serverDomain);
855 	ses->serverDomain = cifs_strndup_from_utf16(data, bleft, true, nls_cp);
856 	cifs_dbg(FYI, "serverDomain=%s\n", ses->serverDomain);
857 
858 	return;
859 }
860 
decode_ascii_ssetup(char ** pbcc_area,__u16 bleft,struct cifs_ses * ses,const struct nls_table * nls_cp)861 static void decode_ascii_ssetup(char **pbcc_area, __u16 bleft,
862 				struct cifs_ses *ses,
863 				const struct nls_table *nls_cp)
864 {
865 	int len;
866 	char *bcc_ptr = *pbcc_area;
867 
868 	cifs_dbg(FYI, "decode sessetup ascii. bleft %d\n", bleft);
869 
870 	len = strnlen(bcc_ptr, bleft);
871 	if (len >= bleft)
872 		return;
873 
874 	kfree(ses->serverOS);
875 
876 	ses->serverOS = kmalloc(len + 1, GFP_KERNEL);
877 	if (ses->serverOS) {
878 		memcpy(ses->serverOS, bcc_ptr, len);
879 		ses->serverOS[len] = 0;
880 		if (strncmp(ses->serverOS, "OS/2", 4) == 0)
881 			cifs_dbg(FYI, "OS/2 server\n");
882 	}
883 
884 	bcc_ptr += len + 1;
885 	bleft -= len + 1;
886 
887 	len = strnlen(bcc_ptr, bleft);
888 	if (len >= bleft)
889 		return;
890 
891 	kfree(ses->serverNOS);
892 
893 	ses->serverNOS = kmalloc(len + 1, GFP_KERNEL);
894 	if (ses->serverNOS) {
895 		memcpy(ses->serverNOS, bcc_ptr, len);
896 		ses->serverNOS[len] = 0;
897 	}
898 
899 	bcc_ptr += len + 1;
900 	bleft -= len + 1;
901 
902 	len = strnlen(bcc_ptr, bleft);
903 	if (len > bleft)
904 		return;
905 
906 	/*
907 	 * No domain field in LANMAN case. Domain is
908 	 * returned by old servers in the SMB negprot response
909 	 *
910 	 * BB For newer servers which do not support Unicode,
911 	 * but thus do return domain here, we could add parsing
912 	 * for it later, but it is not very important
913 	 */
914 	cifs_dbg(FYI, "ascii: bytes left %d\n", bleft);
915 }
916 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
917 
decode_ntlmssp_challenge(char * bcc_ptr,int blob_len,struct cifs_ses * ses)918 int decode_ntlmssp_challenge(char *bcc_ptr, int blob_len,
919 				    struct cifs_ses *ses)
920 {
921 	unsigned int tioffset; /* challenge message target info area */
922 	unsigned int tilen; /* challenge message target info area length  */
923 	CHALLENGE_MESSAGE *pblob = (CHALLENGE_MESSAGE *)bcc_ptr;
924 	__u32 server_flags;
925 
926 	if (blob_len < sizeof(CHALLENGE_MESSAGE)) {
927 		cifs_dbg(VFS, "challenge blob len %d too small\n", blob_len);
928 		return -EINVAL;
929 	}
930 
931 	if (memcmp(pblob->Signature, "NTLMSSP", 8)) {
932 		cifs_dbg(VFS, "blob signature incorrect %s\n",
933 			 pblob->Signature);
934 		return -EINVAL;
935 	}
936 	if (pblob->MessageType != NtLmChallenge) {
937 		cifs_dbg(VFS, "Incorrect message type %d\n",
938 			 pblob->MessageType);
939 		return -EINVAL;
940 	}
941 
942 	server_flags = le32_to_cpu(pblob->NegotiateFlags);
943 	cifs_dbg(FYI, "%s: negotiate=0x%08x challenge=0x%08x\n", __func__,
944 		 ses->ntlmssp->client_flags, server_flags);
945 
946 	if ((ses->ntlmssp->client_flags & (NTLMSSP_NEGOTIATE_SEAL | NTLMSSP_NEGOTIATE_SIGN)) &&
947 	    (!(server_flags & NTLMSSP_NEGOTIATE_56) && !(server_flags & NTLMSSP_NEGOTIATE_128))) {
948 		cifs_dbg(VFS, "%s: requested signing/encryption but server did not return either 56-bit or 128-bit session key size\n",
949 			 __func__);
950 		return -EINVAL;
951 	}
952 	if (!(server_flags & NTLMSSP_NEGOTIATE_NTLM) && !(server_flags & NTLMSSP_NEGOTIATE_EXTENDED_SEC)) {
953 		cifs_dbg(VFS, "%s: server does not seem to support either NTLMv1 or NTLMv2\n", __func__);
954 		return -EINVAL;
955 	}
956 	if (ses->server->sign && !(server_flags & NTLMSSP_NEGOTIATE_SIGN)) {
957 		cifs_dbg(VFS, "%s: forced packet signing but server does not seem to support it\n",
958 			 __func__);
959 		return -EOPNOTSUPP;
960 	}
961 	if ((ses->ntlmssp->client_flags & NTLMSSP_NEGOTIATE_KEY_XCH) &&
962 	    !(server_flags & NTLMSSP_NEGOTIATE_KEY_XCH))
963 		pr_warn_once("%s: authentication has been weakened as server does not support key exchange\n",
964 			     __func__);
965 
966 	ses->ntlmssp->server_flags = server_flags;
967 
968 	memcpy(ses->ntlmssp->cryptkey, pblob->Challenge, CIFS_CRYPTO_KEY_SIZE);
969 	/*
970 	 * In particular we can examine sign flags
971 	 *
972 	 * BB spec says that if AvId field of MsvAvTimestamp is populated then
973 	 * we must set the MIC field of the AUTHENTICATE_MESSAGE
974 	 */
975 
976 	tioffset = le32_to_cpu(pblob->TargetInfoArray.BufferOffset);
977 	tilen = le16_to_cpu(pblob->TargetInfoArray.Length);
978 	if (tioffset > blob_len || tioffset + tilen > blob_len) {
979 		cifs_dbg(VFS, "tioffset + tilen too high %u + %u\n",
980 			 tioffset, tilen);
981 		return -EINVAL;
982 	}
983 	if (tilen) {
984 		kfree_sensitive(ses->auth_key.response);
985 		ses->auth_key.response = kmemdup(bcc_ptr + tioffset, tilen,
986 						 GFP_KERNEL);
987 		if (!ses->auth_key.response) {
988 			cifs_dbg(VFS, "Challenge target info alloc failure\n");
989 			return -ENOMEM;
990 		}
991 		ses->auth_key.len = tilen;
992 	}
993 
994 	return 0;
995 }
996 
size_of_ntlmssp_blob(struct cifs_ses * ses,int base_size)997 static int size_of_ntlmssp_blob(struct cifs_ses *ses, int base_size)
998 {
999 	int sz = base_size + ses->auth_key.len
1000 		- CIFS_SESS_KEY_SIZE + CIFS_CPHTXT_SIZE + 2;
1001 
1002 	if (ses->domainName)
1003 		sz += sizeof(__le16) * strnlen(ses->domainName, CIFS_MAX_DOMAINNAME_LEN);
1004 	else
1005 		sz += sizeof(__le16);
1006 
1007 	if (ses->user_name)
1008 		sz += sizeof(__le16) * strnlen(ses->user_name, CIFS_MAX_USERNAME_LEN);
1009 	else
1010 		sz += sizeof(__le16);
1011 
1012 	if (ses->workstation_name[0])
1013 		sz += sizeof(__le16) * strnlen(ses->workstation_name,
1014 					       ntlmssp_workstation_name_size(ses));
1015 	else
1016 		sz += sizeof(__le16);
1017 
1018 	return sz;
1019 }
1020 
cifs_security_buffer_from_str(SECURITY_BUFFER * pbuf,char * str_value,int str_length,unsigned char * pstart,unsigned char ** pcur,const struct nls_table * nls_cp)1021 static inline void cifs_security_buffer_from_str(SECURITY_BUFFER *pbuf,
1022 						 char *str_value,
1023 						 int str_length,
1024 						 unsigned char *pstart,
1025 						 unsigned char **pcur,
1026 						 const struct nls_table *nls_cp)
1027 {
1028 	unsigned char *tmp = pstart;
1029 	int len;
1030 
1031 	if (!pbuf)
1032 		return;
1033 
1034 	if (!pcur)
1035 		pcur = &tmp;
1036 
1037 	if (!str_value) {
1038 		pbuf->BufferOffset = cpu_to_le32(*pcur - pstart);
1039 		pbuf->Length = 0;
1040 		pbuf->MaximumLength = 0;
1041 		*pcur += sizeof(__le16);
1042 	} else {
1043 		len = cifs_strtoUTF16((__le16 *)*pcur,
1044 				      str_value,
1045 				      str_length,
1046 				      nls_cp);
1047 		len *= sizeof(__le16);
1048 		pbuf->BufferOffset = cpu_to_le32(*pcur - pstart);
1049 		pbuf->Length = cpu_to_le16(len);
1050 		pbuf->MaximumLength = cpu_to_le16(len);
1051 		*pcur += len;
1052 	}
1053 }
1054 
1055 /* BB Move to ntlmssp.c eventually */
1056 
build_ntlmssp_negotiate_blob(unsigned char ** pbuffer,u16 * buflen,struct cifs_ses * ses,struct TCP_Server_Info * server,const struct nls_table * nls_cp)1057 int build_ntlmssp_negotiate_blob(unsigned char **pbuffer,
1058 				 u16 *buflen,
1059 				 struct cifs_ses *ses,
1060 				 struct TCP_Server_Info *server,
1061 				 const struct nls_table *nls_cp)
1062 {
1063 	int rc = 0;
1064 	NEGOTIATE_MESSAGE *sec_blob;
1065 	__u32 flags;
1066 	unsigned char *tmp;
1067 	int len;
1068 
1069 	len = size_of_ntlmssp_blob(ses, sizeof(NEGOTIATE_MESSAGE));
1070 	*pbuffer = kmalloc(len, GFP_KERNEL);
1071 	if (!*pbuffer) {
1072 		rc = -ENOMEM;
1073 		cifs_dbg(VFS, "Error %d during NTLMSSP allocation\n", rc);
1074 		*buflen = 0;
1075 		goto setup_ntlm_neg_ret;
1076 	}
1077 	sec_blob = (NEGOTIATE_MESSAGE *)*pbuffer;
1078 
1079 	memset(*pbuffer, 0, sizeof(NEGOTIATE_MESSAGE));
1080 	memcpy(sec_blob->Signature, NTLMSSP_SIGNATURE, 8);
1081 	sec_blob->MessageType = NtLmNegotiate;
1082 
1083 	/* BB is NTLMV2 session security format easier to use here? */
1084 	flags = NTLMSSP_NEGOTIATE_56 |	NTLMSSP_REQUEST_TARGET |
1085 		NTLMSSP_NEGOTIATE_128 | NTLMSSP_NEGOTIATE_UNICODE |
1086 		NTLMSSP_NEGOTIATE_NTLM | NTLMSSP_NEGOTIATE_EXTENDED_SEC |
1087 		NTLMSSP_NEGOTIATE_ALWAYS_SIGN | NTLMSSP_NEGOTIATE_SEAL |
1088 		NTLMSSP_NEGOTIATE_SIGN;
1089 	if (!server->session_estab || ses->ntlmssp->sesskey_per_smbsess)
1090 		flags |= NTLMSSP_NEGOTIATE_KEY_XCH;
1091 
1092 	tmp = *pbuffer + sizeof(NEGOTIATE_MESSAGE);
1093 	ses->ntlmssp->client_flags = flags;
1094 	sec_blob->NegotiateFlags = cpu_to_le32(flags);
1095 
1096 	/* these fields should be null in negotiate phase MS-NLMP 3.1.5.1.1 */
1097 	cifs_security_buffer_from_str(&sec_blob->DomainName,
1098 				      NULL,
1099 				      CIFS_MAX_DOMAINNAME_LEN,
1100 				      *pbuffer, &tmp,
1101 				      nls_cp);
1102 
1103 	cifs_security_buffer_from_str(&sec_blob->WorkstationName,
1104 				      NULL,
1105 				      CIFS_MAX_WORKSTATION_LEN,
1106 				      *pbuffer, &tmp,
1107 				      nls_cp);
1108 
1109 	*buflen = tmp - *pbuffer;
1110 setup_ntlm_neg_ret:
1111 	return rc;
1112 }
1113 
1114 /*
1115  * Build ntlmssp blob with additional fields, such as version,
1116  * supported by modern servers. For safety limit to SMB3 or later
1117  * See notes in MS-NLMP Section 2.2.2.1 e.g.
1118  */
build_ntlmssp_smb3_negotiate_blob(unsigned char ** pbuffer,u16 * buflen,struct cifs_ses * ses,struct TCP_Server_Info * server,const struct nls_table * nls_cp)1119 int build_ntlmssp_smb3_negotiate_blob(unsigned char **pbuffer,
1120 				 u16 *buflen,
1121 				 struct cifs_ses *ses,
1122 				 struct TCP_Server_Info *server,
1123 				 const struct nls_table *nls_cp)
1124 {
1125 	int rc = 0;
1126 	struct negotiate_message *sec_blob;
1127 	__u32 flags;
1128 	unsigned char *tmp;
1129 	int len;
1130 
1131 	len = size_of_ntlmssp_blob(ses, sizeof(struct negotiate_message));
1132 	*pbuffer = kmalloc(len, GFP_KERNEL);
1133 	if (!*pbuffer) {
1134 		rc = -ENOMEM;
1135 		cifs_dbg(VFS, "Error %d during NTLMSSP allocation\n", rc);
1136 		*buflen = 0;
1137 		goto setup_ntlm_smb3_neg_ret;
1138 	}
1139 	sec_blob = (struct negotiate_message *)*pbuffer;
1140 
1141 	memset(*pbuffer, 0, sizeof(struct negotiate_message));
1142 	memcpy(sec_blob->Signature, NTLMSSP_SIGNATURE, 8);
1143 	sec_blob->MessageType = NtLmNegotiate;
1144 
1145 	/* BB is NTLMV2 session security format easier to use here? */
1146 	flags = NTLMSSP_NEGOTIATE_56 |	NTLMSSP_REQUEST_TARGET |
1147 		NTLMSSP_NEGOTIATE_128 | NTLMSSP_NEGOTIATE_UNICODE |
1148 		NTLMSSP_NEGOTIATE_NTLM | NTLMSSP_NEGOTIATE_EXTENDED_SEC |
1149 		NTLMSSP_NEGOTIATE_ALWAYS_SIGN | NTLMSSP_NEGOTIATE_SEAL |
1150 		NTLMSSP_NEGOTIATE_SIGN | NTLMSSP_NEGOTIATE_VERSION;
1151 	if (!server->session_estab || ses->ntlmssp->sesskey_per_smbsess)
1152 		flags |= NTLMSSP_NEGOTIATE_KEY_XCH;
1153 
1154 	sec_blob->Version.ProductMajorVersion = LINUX_VERSION_MAJOR;
1155 	sec_blob->Version.ProductMinorVersion = LINUX_VERSION_PATCHLEVEL;
1156 	sec_blob->Version.ProductBuild = cpu_to_le16(SMB3_PRODUCT_BUILD);
1157 	sec_blob->Version.NTLMRevisionCurrent = NTLMSSP_REVISION_W2K3;
1158 
1159 	tmp = *pbuffer + sizeof(struct negotiate_message);
1160 	ses->ntlmssp->client_flags = flags;
1161 	sec_blob->NegotiateFlags = cpu_to_le32(flags);
1162 
1163 	/* these fields should be null in negotiate phase MS-NLMP 3.1.5.1.1 */
1164 	cifs_security_buffer_from_str(&sec_blob->DomainName,
1165 				      NULL,
1166 				      CIFS_MAX_DOMAINNAME_LEN,
1167 				      *pbuffer, &tmp,
1168 				      nls_cp);
1169 
1170 	cifs_security_buffer_from_str(&sec_blob->WorkstationName,
1171 				      NULL,
1172 				      CIFS_MAX_WORKSTATION_LEN,
1173 				      *pbuffer, &tmp,
1174 				      nls_cp);
1175 
1176 	*buflen = tmp - *pbuffer;
1177 setup_ntlm_smb3_neg_ret:
1178 	return rc;
1179 }
1180 
1181 
1182 /* See MS-NLMP 2.2.1.3 */
build_ntlmssp_auth_blob(unsigned char ** pbuffer,u16 * buflen,struct cifs_ses * ses,struct TCP_Server_Info * server,const struct nls_table * nls_cp)1183 int build_ntlmssp_auth_blob(unsigned char **pbuffer,
1184 					u16 *buflen,
1185 				   struct cifs_ses *ses,
1186 				   struct TCP_Server_Info *server,
1187 				   const struct nls_table *nls_cp)
1188 {
1189 	int rc;
1190 	AUTHENTICATE_MESSAGE *sec_blob;
1191 	__u32 flags;
1192 	unsigned char *tmp;
1193 	int len;
1194 
1195 	rc = setup_ntlmv2_rsp(ses, nls_cp);
1196 	if (rc) {
1197 		cifs_dbg(VFS, "Error %d during NTLMSSP authentication\n", rc);
1198 		*buflen = 0;
1199 		goto setup_ntlmv2_ret;
1200 	}
1201 
1202 	len = size_of_ntlmssp_blob(ses, sizeof(AUTHENTICATE_MESSAGE));
1203 	*pbuffer = kmalloc(len, GFP_KERNEL);
1204 	if (!*pbuffer) {
1205 		rc = -ENOMEM;
1206 		cifs_dbg(VFS, "Error %d during NTLMSSP allocation\n", rc);
1207 		*buflen = 0;
1208 		goto setup_ntlmv2_ret;
1209 	}
1210 	sec_blob = (AUTHENTICATE_MESSAGE *)*pbuffer;
1211 
1212 	memcpy(sec_blob->Signature, NTLMSSP_SIGNATURE, 8);
1213 	sec_blob->MessageType = NtLmAuthenticate;
1214 
1215 	/* send version information in ntlmssp authenticate also */
1216 	flags = ses->ntlmssp->server_flags | NTLMSSP_REQUEST_TARGET |
1217 		NTLMSSP_NEGOTIATE_TARGET_INFO | NTLMSSP_NEGOTIATE_VERSION |
1218 		NTLMSSP_NEGOTIATE_WORKSTATION_SUPPLIED;
1219 
1220 	sec_blob->Version.ProductMajorVersion = LINUX_VERSION_MAJOR;
1221 	sec_blob->Version.ProductMinorVersion = LINUX_VERSION_PATCHLEVEL;
1222 	sec_blob->Version.ProductBuild = cpu_to_le16(SMB3_PRODUCT_BUILD);
1223 	sec_blob->Version.NTLMRevisionCurrent = NTLMSSP_REVISION_W2K3;
1224 
1225 	tmp = *pbuffer + sizeof(AUTHENTICATE_MESSAGE);
1226 	sec_blob->NegotiateFlags = cpu_to_le32(flags);
1227 
1228 	sec_blob->LmChallengeResponse.BufferOffset =
1229 				cpu_to_le32(sizeof(AUTHENTICATE_MESSAGE));
1230 	sec_blob->LmChallengeResponse.Length = 0;
1231 	sec_blob->LmChallengeResponse.MaximumLength = 0;
1232 
1233 	sec_blob->NtChallengeResponse.BufferOffset =
1234 				cpu_to_le32(tmp - *pbuffer);
1235 	if (ses->user_name != NULL) {
1236 		memcpy(tmp, ses->auth_key.response + CIFS_SESS_KEY_SIZE,
1237 				ses->auth_key.len - CIFS_SESS_KEY_SIZE);
1238 		tmp += ses->auth_key.len - CIFS_SESS_KEY_SIZE;
1239 
1240 		sec_blob->NtChallengeResponse.Length =
1241 				cpu_to_le16(ses->auth_key.len - CIFS_SESS_KEY_SIZE);
1242 		sec_blob->NtChallengeResponse.MaximumLength =
1243 				cpu_to_le16(ses->auth_key.len - CIFS_SESS_KEY_SIZE);
1244 	} else {
1245 		/*
1246 		 * don't send an NT Response for anonymous access
1247 		 */
1248 		sec_blob->NtChallengeResponse.Length = 0;
1249 		sec_blob->NtChallengeResponse.MaximumLength = 0;
1250 	}
1251 
1252 	cifs_security_buffer_from_str(&sec_blob->DomainName,
1253 				      ses->domainName,
1254 				      CIFS_MAX_DOMAINNAME_LEN,
1255 				      *pbuffer, &tmp,
1256 				      nls_cp);
1257 
1258 	cifs_security_buffer_from_str(&sec_blob->UserName,
1259 				      ses->user_name,
1260 				      CIFS_MAX_USERNAME_LEN,
1261 				      *pbuffer, &tmp,
1262 				      nls_cp);
1263 
1264 	cifs_security_buffer_from_str(&sec_blob->WorkstationName,
1265 				      ses->workstation_name,
1266 				      ntlmssp_workstation_name_size(ses),
1267 				      *pbuffer, &tmp,
1268 				      nls_cp);
1269 
1270 	if ((ses->ntlmssp->server_flags & NTLMSSP_NEGOTIATE_KEY_XCH) &&
1271 	    (!ses->server->session_estab || ses->ntlmssp->sesskey_per_smbsess) &&
1272 	    !calc_seckey(ses)) {
1273 		memcpy(tmp, ses->ntlmssp->ciphertext, CIFS_CPHTXT_SIZE);
1274 		sec_blob->SessionKey.BufferOffset = cpu_to_le32(tmp - *pbuffer);
1275 		sec_blob->SessionKey.Length = cpu_to_le16(CIFS_CPHTXT_SIZE);
1276 		sec_blob->SessionKey.MaximumLength =
1277 				cpu_to_le16(CIFS_CPHTXT_SIZE);
1278 		tmp += CIFS_CPHTXT_SIZE;
1279 	} else {
1280 		sec_blob->SessionKey.BufferOffset = cpu_to_le32(tmp - *pbuffer);
1281 		sec_blob->SessionKey.Length = 0;
1282 		sec_blob->SessionKey.MaximumLength = 0;
1283 	}
1284 
1285 	*buflen = tmp - *pbuffer;
1286 setup_ntlmv2_ret:
1287 	return rc;
1288 }
1289 
1290 enum securityEnum
cifs_select_sectype(struct TCP_Server_Info * server,enum securityEnum requested)1291 cifs_select_sectype(struct TCP_Server_Info *server, enum securityEnum requested)
1292 {
1293 	switch (server->negflavor) {
1294 	case CIFS_NEGFLAVOR_EXTENDED:
1295 		switch (requested) {
1296 		case Kerberos:
1297 		case RawNTLMSSP:
1298 			return requested;
1299 		case Unspecified:
1300 			if (server->sec_ntlmssp &&
1301 			    (global_secflags & CIFSSEC_MAY_NTLMSSP))
1302 				return RawNTLMSSP;
1303 			if ((server->sec_kerberos || server->sec_mskerberos) &&
1304 			    (global_secflags & CIFSSEC_MAY_KRB5))
1305 				return Kerberos;
1306 			fallthrough;
1307 		default:
1308 			return Unspecified;
1309 		}
1310 	case CIFS_NEGFLAVOR_UNENCAP:
1311 		switch (requested) {
1312 		case NTLMv2:
1313 			return requested;
1314 		case Unspecified:
1315 			if (global_secflags & CIFSSEC_MAY_NTLMV2)
1316 				return NTLMv2;
1317 			break;
1318 		default:
1319 			break;
1320 		}
1321 		fallthrough;
1322 	default:
1323 		return Unspecified;
1324 	}
1325 }
1326 
1327 struct sess_data {
1328 	unsigned int xid;
1329 	struct cifs_ses *ses;
1330 	struct TCP_Server_Info *server;
1331 	struct nls_table *nls_cp;
1332 	void (*func)(struct sess_data *);
1333 	int result;
1334 
1335 	/* we will send the SMB in three pieces:
1336 	 * a fixed length beginning part, an optional
1337 	 * SPNEGO blob (which can be zero length), and a
1338 	 * last part which will include the strings
1339 	 * and rest of bcc area. This allows us to avoid
1340 	 * a large buffer 17K allocation
1341 	 */
1342 	int buf0_type;
1343 	struct kvec iov[3];
1344 };
1345 
1346 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
1347 static int
sess_alloc_buffer(struct sess_data * sess_data,int wct)1348 sess_alloc_buffer(struct sess_data *sess_data, int wct)
1349 {
1350 	int rc;
1351 	struct cifs_ses *ses = sess_data->ses;
1352 	struct smb_hdr *smb_buf;
1353 
1354 	rc = small_smb_init_no_tc(SMB_COM_SESSION_SETUP_ANDX, wct, ses,
1355 				  (void **)&smb_buf);
1356 
1357 	if (rc)
1358 		return rc;
1359 
1360 	sess_data->iov[0].iov_base = (char *)smb_buf;
1361 	sess_data->iov[0].iov_len = be32_to_cpu(smb_buf->smb_buf_length) + 4;
1362 	/*
1363 	 * This variable will be used to clear the buffer
1364 	 * allocated above in case of any error in the calling function.
1365 	 */
1366 	sess_data->buf0_type = CIFS_SMALL_BUFFER;
1367 
1368 	/* 2000 big enough to fit max user, domain, NOS name etc. */
1369 	sess_data->iov[2].iov_base = kmalloc(2000, GFP_KERNEL);
1370 	if (!sess_data->iov[2].iov_base) {
1371 		rc = -ENOMEM;
1372 		goto out_free_smb_buf;
1373 	}
1374 
1375 	return 0;
1376 
1377 out_free_smb_buf:
1378 	cifs_small_buf_release(smb_buf);
1379 	sess_data->iov[0].iov_base = NULL;
1380 	sess_data->iov[0].iov_len = 0;
1381 	sess_data->buf0_type = CIFS_NO_BUFFER;
1382 	return rc;
1383 }
1384 
1385 static void
sess_free_buffer(struct sess_data * sess_data)1386 sess_free_buffer(struct sess_data *sess_data)
1387 {
1388 	struct kvec *iov = sess_data->iov;
1389 
1390 	/*
1391 	 * Zero the session data before freeing, as it might contain sensitive info (keys, etc).
1392 	 * Note that iov[1] is already freed by caller.
1393 	 */
1394 	if (sess_data->buf0_type != CIFS_NO_BUFFER && iov[0].iov_base)
1395 		memzero_explicit(iov[0].iov_base, iov[0].iov_len);
1396 
1397 	free_rsp_buf(sess_data->buf0_type, iov[0].iov_base);
1398 	sess_data->buf0_type = CIFS_NO_BUFFER;
1399 	kfree_sensitive(iov[2].iov_base);
1400 }
1401 
1402 static int
sess_establish_session(struct sess_data * sess_data)1403 sess_establish_session(struct sess_data *sess_data)
1404 {
1405 	struct cifs_ses *ses = sess_data->ses;
1406 	struct TCP_Server_Info *server = sess_data->server;
1407 
1408 	cifs_server_lock(server);
1409 	if (!server->session_estab) {
1410 		if (server->sign) {
1411 			server->session_key.response =
1412 				kmemdup(ses->auth_key.response,
1413 				ses->auth_key.len, GFP_KERNEL);
1414 			if (!server->session_key.response) {
1415 				cifs_server_unlock(server);
1416 				return -ENOMEM;
1417 			}
1418 			server->session_key.len =
1419 						ses->auth_key.len;
1420 		}
1421 		server->sequence_number = 0x2;
1422 		server->session_estab = true;
1423 	}
1424 	cifs_server_unlock(server);
1425 
1426 	cifs_dbg(FYI, "CIFS session established successfully\n");
1427 	return 0;
1428 }
1429 
1430 static int
sess_sendreceive(struct sess_data * sess_data)1431 sess_sendreceive(struct sess_data *sess_data)
1432 {
1433 	int rc;
1434 	struct smb_hdr *smb_buf = (struct smb_hdr *) sess_data->iov[0].iov_base;
1435 	__u16 count;
1436 	struct kvec rsp_iov = { NULL, 0 };
1437 
1438 	count = sess_data->iov[1].iov_len + sess_data->iov[2].iov_len;
1439 	be32_add_cpu(&smb_buf->smb_buf_length, count);
1440 	put_bcc(count, smb_buf);
1441 
1442 	rc = SendReceive2(sess_data->xid, sess_data->ses,
1443 			  sess_data->iov, 3 /* num_iovecs */,
1444 			  &sess_data->buf0_type,
1445 			  CIFS_LOG_ERROR, &rsp_iov);
1446 	cifs_small_buf_release(sess_data->iov[0].iov_base);
1447 	memcpy(&sess_data->iov[0], &rsp_iov, sizeof(struct kvec));
1448 
1449 	return rc;
1450 }
1451 
1452 static void
sess_auth_ntlmv2(struct sess_data * sess_data)1453 sess_auth_ntlmv2(struct sess_data *sess_data)
1454 {
1455 	int rc = 0;
1456 	struct smb_hdr *smb_buf;
1457 	SESSION_SETUP_ANDX *pSMB;
1458 	char *bcc_ptr;
1459 	struct cifs_ses *ses = sess_data->ses;
1460 	struct TCP_Server_Info *server = sess_data->server;
1461 	__u32 capabilities;
1462 	__u16 bytes_remaining;
1463 
1464 	/* old style NTLM sessionsetup */
1465 	/* wct = 13 */
1466 	rc = sess_alloc_buffer(sess_data, 13);
1467 	if (rc)
1468 		goto out;
1469 
1470 	pSMB = (SESSION_SETUP_ANDX *)sess_data->iov[0].iov_base;
1471 	bcc_ptr = sess_data->iov[2].iov_base;
1472 	capabilities = cifs_ssetup_hdr(ses, server, pSMB);
1473 
1474 	pSMB->req_no_secext.Capabilities = cpu_to_le32(capabilities);
1475 
1476 	/* LM2 password would be here if we supported it */
1477 	pSMB->req_no_secext.CaseInsensitivePasswordLength = 0;
1478 
1479 	if (ses->user_name != NULL) {
1480 		/* calculate nlmv2 response and session key */
1481 		rc = setup_ntlmv2_rsp(ses, sess_data->nls_cp);
1482 		if (rc) {
1483 			cifs_dbg(VFS, "Error %d during NTLMv2 authentication\n", rc);
1484 			goto out;
1485 		}
1486 
1487 		memcpy(bcc_ptr, ses->auth_key.response + CIFS_SESS_KEY_SIZE,
1488 				ses->auth_key.len - CIFS_SESS_KEY_SIZE);
1489 		bcc_ptr += ses->auth_key.len - CIFS_SESS_KEY_SIZE;
1490 
1491 		/* set case sensitive password length after tilen may get
1492 		 * assigned, tilen is 0 otherwise.
1493 		 */
1494 		pSMB->req_no_secext.CaseSensitivePasswordLength =
1495 			cpu_to_le16(ses->auth_key.len - CIFS_SESS_KEY_SIZE);
1496 	} else {
1497 		pSMB->req_no_secext.CaseSensitivePasswordLength = 0;
1498 	}
1499 
1500 	if (ses->capabilities & CAP_UNICODE) {
1501 		if (!IS_ALIGNED(sess_data->iov[0].iov_len, 2)) {
1502 			*bcc_ptr = 0;
1503 			bcc_ptr++;
1504 		}
1505 		unicode_ssetup_strings(&bcc_ptr, ses, sess_data->nls_cp);
1506 	} else {
1507 		ascii_ssetup_strings(&bcc_ptr, ses, sess_data->nls_cp);
1508 	}
1509 
1510 
1511 	sess_data->iov[2].iov_len = (long) bcc_ptr -
1512 			(long) sess_data->iov[2].iov_base;
1513 
1514 	rc = sess_sendreceive(sess_data);
1515 	if (rc)
1516 		goto out;
1517 
1518 	pSMB = (SESSION_SETUP_ANDX *)sess_data->iov[0].iov_base;
1519 	smb_buf = (struct smb_hdr *)sess_data->iov[0].iov_base;
1520 
1521 	if (smb_buf->WordCount != 3) {
1522 		rc = -EIO;
1523 		cifs_dbg(VFS, "bad word count %d\n", smb_buf->WordCount);
1524 		goto out;
1525 	}
1526 
1527 	if (le16_to_cpu(pSMB->resp.Action) & GUEST_LOGIN)
1528 		cifs_dbg(FYI, "Guest login\n"); /* BB mark SesInfo struct? */
1529 
1530 	ses->Suid = smb_buf->Uid;   /* UID left in wire format (le) */
1531 	cifs_dbg(FYI, "UID = %llu\n", ses->Suid);
1532 
1533 	bytes_remaining = get_bcc(smb_buf);
1534 	bcc_ptr = pByteArea(smb_buf);
1535 
1536 	/* BB check if Unicode and decode strings */
1537 	if (bytes_remaining == 0) {
1538 		/* no string area to decode, do nothing */
1539 	} else if (smb_buf->Flags2 & SMBFLG2_UNICODE) {
1540 		/* unicode string area must be word-aligned */
1541 		if (!IS_ALIGNED((unsigned long)bcc_ptr - (unsigned long)smb_buf, 2)) {
1542 			++bcc_ptr;
1543 			--bytes_remaining;
1544 		}
1545 		decode_unicode_ssetup(&bcc_ptr, bytes_remaining, ses,
1546 				      sess_data->nls_cp);
1547 	} else {
1548 		decode_ascii_ssetup(&bcc_ptr, bytes_remaining, ses,
1549 				    sess_data->nls_cp);
1550 	}
1551 
1552 	rc = sess_establish_session(sess_data);
1553 out:
1554 	sess_data->result = rc;
1555 	sess_data->func = NULL;
1556 	sess_free_buffer(sess_data);
1557 	kfree_sensitive(ses->auth_key.response);
1558 	ses->auth_key.response = NULL;
1559 }
1560 
1561 #ifdef CONFIG_CIFS_UPCALL
1562 static void
sess_auth_kerberos(struct sess_data * sess_data)1563 sess_auth_kerberos(struct sess_data *sess_data)
1564 {
1565 	int rc = 0;
1566 	struct smb_hdr *smb_buf;
1567 	SESSION_SETUP_ANDX *pSMB;
1568 	char *bcc_ptr;
1569 	struct cifs_ses *ses = sess_data->ses;
1570 	struct TCP_Server_Info *server = sess_data->server;
1571 	__u32 capabilities;
1572 	__u16 bytes_remaining;
1573 	struct key *spnego_key = NULL;
1574 	struct cifs_spnego_msg *msg;
1575 	u16 blob_len;
1576 
1577 	/* extended security */
1578 	/* wct = 12 */
1579 	rc = sess_alloc_buffer(sess_data, 12);
1580 	if (rc)
1581 		goto out;
1582 
1583 	pSMB = (SESSION_SETUP_ANDX *)sess_data->iov[0].iov_base;
1584 	bcc_ptr = sess_data->iov[2].iov_base;
1585 	capabilities = cifs_ssetup_hdr(ses, server, pSMB);
1586 
1587 	spnego_key = cifs_get_spnego_key(ses, server);
1588 	if (IS_ERR(spnego_key)) {
1589 		rc = PTR_ERR(spnego_key);
1590 		spnego_key = NULL;
1591 		goto out;
1592 	}
1593 
1594 	msg = spnego_key->payload.data[0];
1595 	/*
1596 	 * check version field to make sure that cifs.upcall is
1597 	 * sending us a response in an expected form
1598 	 */
1599 	if (msg->version != CIFS_SPNEGO_UPCALL_VERSION) {
1600 		cifs_dbg(VFS, "incorrect version of cifs.upcall (expected %d but got %d)\n",
1601 			 CIFS_SPNEGO_UPCALL_VERSION, msg->version);
1602 		rc = -EKEYREJECTED;
1603 		goto out_put_spnego_key;
1604 	}
1605 
1606 	kfree_sensitive(ses->auth_key.response);
1607 	ses->auth_key.response = kmemdup(msg->data, msg->sesskey_len,
1608 					 GFP_KERNEL);
1609 	if (!ses->auth_key.response) {
1610 		cifs_dbg(VFS, "Kerberos can't allocate (%u bytes) memory\n",
1611 			 msg->sesskey_len);
1612 		rc = -ENOMEM;
1613 		goto out_put_spnego_key;
1614 	}
1615 	ses->auth_key.len = msg->sesskey_len;
1616 
1617 	pSMB->req.hdr.Flags2 |= SMBFLG2_EXT_SEC;
1618 	capabilities |= CAP_EXTENDED_SECURITY;
1619 	pSMB->req.Capabilities = cpu_to_le32(capabilities);
1620 	sess_data->iov[1].iov_base = msg->data + msg->sesskey_len;
1621 	sess_data->iov[1].iov_len = msg->secblob_len;
1622 	pSMB->req.SecurityBlobLength = cpu_to_le16(sess_data->iov[1].iov_len);
1623 
1624 	if (ses->capabilities & CAP_UNICODE) {
1625 		/* unicode strings must be word aligned */
1626 		if (!IS_ALIGNED(sess_data->iov[0].iov_len + sess_data->iov[1].iov_len, 2)) {
1627 			*bcc_ptr = 0;
1628 			bcc_ptr++;
1629 		}
1630 		unicode_oslm_strings(&bcc_ptr, sess_data->nls_cp);
1631 		unicode_domain_string(&bcc_ptr, ses, sess_data->nls_cp);
1632 	} else {
1633 		/* BB: is this right? */
1634 		ascii_ssetup_strings(&bcc_ptr, ses, sess_data->nls_cp);
1635 	}
1636 
1637 	sess_data->iov[2].iov_len = (long) bcc_ptr -
1638 			(long) sess_data->iov[2].iov_base;
1639 
1640 	rc = sess_sendreceive(sess_data);
1641 	if (rc)
1642 		goto out_put_spnego_key;
1643 
1644 	pSMB = (SESSION_SETUP_ANDX *)sess_data->iov[0].iov_base;
1645 	smb_buf = (struct smb_hdr *)sess_data->iov[0].iov_base;
1646 
1647 	if (smb_buf->WordCount != 4) {
1648 		rc = -EIO;
1649 		cifs_dbg(VFS, "bad word count %d\n", smb_buf->WordCount);
1650 		goto out_put_spnego_key;
1651 	}
1652 
1653 	if (le16_to_cpu(pSMB->resp.Action) & GUEST_LOGIN)
1654 		cifs_dbg(FYI, "Guest login\n"); /* BB mark SesInfo struct? */
1655 
1656 	ses->Suid = smb_buf->Uid;   /* UID left in wire format (le) */
1657 	cifs_dbg(FYI, "UID = %llu\n", ses->Suid);
1658 
1659 	bytes_remaining = get_bcc(smb_buf);
1660 	bcc_ptr = pByteArea(smb_buf);
1661 
1662 	blob_len = le16_to_cpu(pSMB->resp.SecurityBlobLength);
1663 	if (blob_len > bytes_remaining) {
1664 		cifs_dbg(VFS, "bad security blob length %d\n",
1665 				blob_len);
1666 		rc = -EINVAL;
1667 		goto out_put_spnego_key;
1668 	}
1669 	bcc_ptr += blob_len;
1670 	bytes_remaining -= blob_len;
1671 
1672 	/* BB check if Unicode and decode strings */
1673 	if (bytes_remaining == 0) {
1674 		/* no string area to decode, do nothing */
1675 	} else if (smb_buf->Flags2 & SMBFLG2_UNICODE) {
1676 		/* unicode string area must be word-aligned */
1677 		if (!IS_ALIGNED((unsigned long)bcc_ptr - (unsigned long)smb_buf, 2)) {
1678 			++bcc_ptr;
1679 			--bytes_remaining;
1680 		}
1681 		decode_unicode_ssetup(&bcc_ptr, bytes_remaining, ses,
1682 				      sess_data->nls_cp);
1683 	} else {
1684 		decode_ascii_ssetup(&bcc_ptr, bytes_remaining, ses,
1685 				    sess_data->nls_cp);
1686 	}
1687 
1688 	rc = sess_establish_session(sess_data);
1689 out_put_spnego_key:
1690 	key_invalidate(spnego_key);
1691 	key_put(spnego_key);
1692 out:
1693 	sess_data->result = rc;
1694 	sess_data->func = NULL;
1695 	sess_free_buffer(sess_data);
1696 	kfree_sensitive(ses->auth_key.response);
1697 	ses->auth_key.response = NULL;
1698 }
1699 
1700 #endif /* ! CONFIG_CIFS_UPCALL */
1701 
1702 /*
1703  * The required kvec buffers have to be allocated before calling this
1704  * function.
1705  */
1706 static int
_sess_auth_rawntlmssp_assemble_req(struct sess_data * sess_data)1707 _sess_auth_rawntlmssp_assemble_req(struct sess_data *sess_data)
1708 {
1709 	SESSION_SETUP_ANDX *pSMB;
1710 	struct cifs_ses *ses = sess_data->ses;
1711 	struct TCP_Server_Info *server = sess_data->server;
1712 	__u32 capabilities;
1713 	char *bcc_ptr;
1714 
1715 	pSMB = (SESSION_SETUP_ANDX *)sess_data->iov[0].iov_base;
1716 
1717 	capabilities = cifs_ssetup_hdr(ses, server, pSMB);
1718 	if ((pSMB->req.hdr.Flags2 & SMBFLG2_UNICODE) == 0) {
1719 		cifs_dbg(VFS, "NTLMSSP requires Unicode support\n");
1720 		return -ENOSYS;
1721 	}
1722 
1723 	pSMB->req.hdr.Flags2 |= SMBFLG2_EXT_SEC;
1724 	capabilities |= CAP_EXTENDED_SECURITY;
1725 	pSMB->req.Capabilities |= cpu_to_le32(capabilities);
1726 
1727 	bcc_ptr = sess_data->iov[2].iov_base;
1728 	/* unicode strings must be word aligned */
1729 	if (!IS_ALIGNED(sess_data->iov[0].iov_len + sess_data->iov[1].iov_len, 2)) {
1730 		*bcc_ptr = 0;
1731 		bcc_ptr++;
1732 	}
1733 	unicode_oslm_strings(&bcc_ptr, sess_data->nls_cp);
1734 
1735 	sess_data->iov[2].iov_len = (long) bcc_ptr -
1736 					(long) sess_data->iov[2].iov_base;
1737 
1738 	return 0;
1739 }
1740 
1741 static void
1742 sess_auth_rawntlmssp_authenticate(struct sess_data *sess_data);
1743 
1744 static void
sess_auth_rawntlmssp_negotiate(struct sess_data * sess_data)1745 sess_auth_rawntlmssp_negotiate(struct sess_data *sess_data)
1746 {
1747 	int rc;
1748 	struct smb_hdr *smb_buf;
1749 	SESSION_SETUP_ANDX *pSMB;
1750 	struct cifs_ses *ses = sess_data->ses;
1751 	struct TCP_Server_Info *server = sess_data->server;
1752 	__u16 bytes_remaining;
1753 	char *bcc_ptr;
1754 	unsigned char *ntlmsspblob = NULL;
1755 	u16 blob_len;
1756 
1757 	cifs_dbg(FYI, "rawntlmssp session setup negotiate phase\n");
1758 
1759 	/*
1760 	 * if memory allocation is successful, caller of this function
1761 	 * frees it.
1762 	 */
1763 	ses->ntlmssp = kmalloc(sizeof(struct ntlmssp_auth), GFP_KERNEL);
1764 	if (!ses->ntlmssp) {
1765 		rc = -ENOMEM;
1766 		goto out;
1767 	}
1768 	ses->ntlmssp->sesskey_per_smbsess = false;
1769 
1770 	/* wct = 12 */
1771 	rc = sess_alloc_buffer(sess_data, 12);
1772 	if (rc)
1773 		goto out;
1774 
1775 	pSMB = (SESSION_SETUP_ANDX *)sess_data->iov[0].iov_base;
1776 
1777 	/* Build security blob before we assemble the request */
1778 	rc = build_ntlmssp_negotiate_blob(&ntlmsspblob,
1779 				     &blob_len, ses, server,
1780 				     sess_data->nls_cp);
1781 	if (rc)
1782 		goto out_free_ntlmsspblob;
1783 
1784 	sess_data->iov[1].iov_len = blob_len;
1785 	sess_data->iov[1].iov_base = ntlmsspblob;
1786 	pSMB->req.SecurityBlobLength = cpu_to_le16(blob_len);
1787 
1788 	rc = _sess_auth_rawntlmssp_assemble_req(sess_data);
1789 	if (rc)
1790 		goto out_free_ntlmsspblob;
1791 
1792 	rc = sess_sendreceive(sess_data);
1793 
1794 	pSMB = (SESSION_SETUP_ANDX *)sess_data->iov[0].iov_base;
1795 	smb_buf = (struct smb_hdr *)sess_data->iov[0].iov_base;
1796 
1797 	/* If true, rc here is expected and not an error */
1798 	if (sess_data->buf0_type != CIFS_NO_BUFFER &&
1799 	    smb_buf->Status.CifsError ==
1800 			cpu_to_le32(NT_STATUS_MORE_PROCESSING_REQUIRED))
1801 		rc = 0;
1802 
1803 	if (rc)
1804 		goto out_free_ntlmsspblob;
1805 
1806 	cifs_dbg(FYI, "rawntlmssp session setup challenge phase\n");
1807 
1808 	if (smb_buf->WordCount != 4) {
1809 		rc = -EIO;
1810 		cifs_dbg(VFS, "bad word count %d\n", smb_buf->WordCount);
1811 		goto out_free_ntlmsspblob;
1812 	}
1813 
1814 	ses->Suid = smb_buf->Uid;   /* UID left in wire format (le) */
1815 	cifs_dbg(FYI, "UID = %llu\n", ses->Suid);
1816 
1817 	bytes_remaining = get_bcc(smb_buf);
1818 	bcc_ptr = pByteArea(smb_buf);
1819 
1820 	blob_len = le16_to_cpu(pSMB->resp.SecurityBlobLength);
1821 	if (blob_len > bytes_remaining) {
1822 		cifs_dbg(VFS, "bad security blob length %d\n",
1823 				blob_len);
1824 		rc = -EINVAL;
1825 		goto out_free_ntlmsspblob;
1826 	}
1827 
1828 	rc = decode_ntlmssp_challenge(bcc_ptr, blob_len, ses);
1829 
1830 out_free_ntlmsspblob:
1831 	kfree_sensitive(ntlmsspblob);
1832 out:
1833 	sess_free_buffer(sess_data);
1834 
1835 	if (!rc) {
1836 		sess_data->func = sess_auth_rawntlmssp_authenticate;
1837 		return;
1838 	}
1839 
1840 	/* Else error. Cleanup */
1841 	kfree_sensitive(ses->auth_key.response);
1842 	ses->auth_key.response = NULL;
1843 	kfree_sensitive(ses->ntlmssp);
1844 	ses->ntlmssp = NULL;
1845 
1846 	sess_data->func = NULL;
1847 	sess_data->result = rc;
1848 }
1849 
1850 static void
sess_auth_rawntlmssp_authenticate(struct sess_data * sess_data)1851 sess_auth_rawntlmssp_authenticate(struct sess_data *sess_data)
1852 {
1853 	int rc;
1854 	struct smb_hdr *smb_buf;
1855 	SESSION_SETUP_ANDX *pSMB;
1856 	struct cifs_ses *ses = sess_data->ses;
1857 	struct TCP_Server_Info *server = sess_data->server;
1858 	__u16 bytes_remaining;
1859 	char *bcc_ptr;
1860 	unsigned char *ntlmsspblob = NULL;
1861 	u16 blob_len;
1862 
1863 	cifs_dbg(FYI, "rawntlmssp session setup authenticate phase\n");
1864 
1865 	/* wct = 12 */
1866 	rc = sess_alloc_buffer(sess_data, 12);
1867 	if (rc)
1868 		goto out;
1869 
1870 	/* Build security blob before we assemble the request */
1871 	pSMB = (SESSION_SETUP_ANDX *)sess_data->iov[0].iov_base;
1872 	smb_buf = (struct smb_hdr *)pSMB;
1873 	rc = build_ntlmssp_auth_blob(&ntlmsspblob,
1874 					&blob_len, ses, server,
1875 					sess_data->nls_cp);
1876 	if (rc)
1877 		goto out_free_ntlmsspblob;
1878 	sess_data->iov[1].iov_len = blob_len;
1879 	sess_data->iov[1].iov_base = ntlmsspblob;
1880 	pSMB->req.SecurityBlobLength = cpu_to_le16(blob_len);
1881 	/*
1882 	 * Make sure that we tell the server that we are using
1883 	 * the uid that it just gave us back on the response
1884 	 * (challenge)
1885 	 */
1886 	smb_buf->Uid = ses->Suid;
1887 
1888 	rc = _sess_auth_rawntlmssp_assemble_req(sess_data);
1889 	if (rc)
1890 		goto out_free_ntlmsspblob;
1891 
1892 	rc = sess_sendreceive(sess_data);
1893 	if (rc)
1894 		goto out_free_ntlmsspblob;
1895 
1896 	pSMB = (SESSION_SETUP_ANDX *)sess_data->iov[0].iov_base;
1897 	smb_buf = (struct smb_hdr *)sess_data->iov[0].iov_base;
1898 	if (smb_buf->WordCount != 4) {
1899 		rc = -EIO;
1900 		cifs_dbg(VFS, "bad word count %d\n", smb_buf->WordCount);
1901 		goto out_free_ntlmsspblob;
1902 	}
1903 
1904 	if (le16_to_cpu(pSMB->resp.Action) & GUEST_LOGIN)
1905 		cifs_dbg(FYI, "Guest login\n"); /* BB mark SesInfo struct? */
1906 
1907 	if (ses->Suid != smb_buf->Uid) {
1908 		ses->Suid = smb_buf->Uid;
1909 		cifs_dbg(FYI, "UID changed! new UID = %llu\n", ses->Suid);
1910 	}
1911 
1912 	bytes_remaining = get_bcc(smb_buf);
1913 	bcc_ptr = pByteArea(smb_buf);
1914 	blob_len = le16_to_cpu(pSMB->resp.SecurityBlobLength);
1915 	if (blob_len > bytes_remaining) {
1916 		cifs_dbg(VFS, "bad security blob length %d\n",
1917 				blob_len);
1918 		rc = -EINVAL;
1919 		goto out_free_ntlmsspblob;
1920 	}
1921 	bcc_ptr += blob_len;
1922 	bytes_remaining -= blob_len;
1923 
1924 
1925 	/* BB check if Unicode and decode strings */
1926 	if (bytes_remaining == 0) {
1927 		/* no string area to decode, do nothing */
1928 	} else if (smb_buf->Flags2 & SMBFLG2_UNICODE) {
1929 		/* unicode string area must be word-aligned */
1930 		if (!IS_ALIGNED((unsigned long)bcc_ptr - (unsigned long)smb_buf, 2)) {
1931 			++bcc_ptr;
1932 			--bytes_remaining;
1933 		}
1934 		decode_unicode_ssetup(&bcc_ptr, bytes_remaining, ses,
1935 				      sess_data->nls_cp);
1936 	} else {
1937 		decode_ascii_ssetup(&bcc_ptr, bytes_remaining, ses,
1938 				    sess_data->nls_cp);
1939 	}
1940 
1941 out_free_ntlmsspblob:
1942 	kfree_sensitive(ntlmsspblob);
1943 out:
1944 	sess_free_buffer(sess_data);
1945 
1946 	if (!rc)
1947 		rc = sess_establish_session(sess_data);
1948 
1949 	/* Cleanup */
1950 	kfree_sensitive(ses->auth_key.response);
1951 	ses->auth_key.response = NULL;
1952 	kfree_sensitive(ses->ntlmssp);
1953 	ses->ntlmssp = NULL;
1954 
1955 	sess_data->func = NULL;
1956 	sess_data->result = rc;
1957 }
1958 
select_sec(struct sess_data * sess_data)1959 static int select_sec(struct sess_data *sess_data)
1960 {
1961 	int type;
1962 	struct cifs_ses *ses = sess_data->ses;
1963 	struct TCP_Server_Info *server = sess_data->server;
1964 
1965 	type = cifs_select_sectype(server, ses->sectype);
1966 	cifs_dbg(FYI, "sess setup type %d\n", type);
1967 	if (type == Unspecified) {
1968 		cifs_dbg(VFS, "Unable to select appropriate authentication method!\n");
1969 		return -EINVAL;
1970 	}
1971 
1972 	switch (type) {
1973 	case NTLMv2:
1974 		sess_data->func = sess_auth_ntlmv2;
1975 		break;
1976 	case Kerberos:
1977 #ifdef CONFIG_CIFS_UPCALL
1978 		sess_data->func = sess_auth_kerberos;
1979 		break;
1980 #else
1981 		cifs_dbg(VFS, "Kerberos negotiated but upcall support disabled!\n");
1982 		return -ENOSYS;
1983 #endif /* CONFIG_CIFS_UPCALL */
1984 	case RawNTLMSSP:
1985 		sess_data->func = sess_auth_rawntlmssp_negotiate;
1986 		break;
1987 	default:
1988 		cifs_dbg(VFS, "secType %d not supported!\n", type);
1989 		return -ENOSYS;
1990 	}
1991 
1992 	return 0;
1993 }
1994 
CIFS_SessSetup(const unsigned int xid,struct cifs_ses * ses,struct TCP_Server_Info * server,const struct nls_table * nls_cp)1995 int CIFS_SessSetup(const unsigned int xid, struct cifs_ses *ses,
1996 		   struct TCP_Server_Info *server,
1997 		   const struct nls_table *nls_cp)
1998 {
1999 	int rc = 0;
2000 	struct sess_data *sess_data;
2001 
2002 	if (ses == NULL) {
2003 		WARN(1, "%s: ses == NULL!", __func__);
2004 		return -EINVAL;
2005 	}
2006 
2007 	sess_data = kzalloc(sizeof(struct sess_data), GFP_KERNEL);
2008 	if (!sess_data)
2009 		return -ENOMEM;
2010 
2011 	sess_data->xid = xid;
2012 	sess_data->ses = ses;
2013 	sess_data->server = server;
2014 	sess_data->buf0_type = CIFS_NO_BUFFER;
2015 	sess_data->nls_cp = (struct nls_table *) nls_cp;
2016 
2017 	rc = select_sec(sess_data);
2018 	if (rc)
2019 		goto out;
2020 
2021 	while (sess_data->func)
2022 		sess_data->func(sess_data);
2023 
2024 	/* Store result before we free sess_data */
2025 	rc = sess_data->result;
2026 
2027 out:
2028 	kfree_sensitive(sess_data);
2029 	return rc;
2030 }
2031 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
2032