xref: /linux/fs/smb/client/sess.c (revision db68e4c80d995b67a92460711038b9223166bda7)
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 
is_ses_using_iface(struct cifs_ses * ses,struct cifs_server_iface * iface)30 bool is_ses_using_iface(struct cifs_ses *ses, struct cifs_server_iface *iface)
31 {
32 	int i;
33 
34 	spin_lock(&ses->chan_lock);
35 	for (i = 0; i < ses->chan_count; i++) {
36 		if (ses->chans[i].iface == iface) {
37 			spin_unlock(&ses->chan_lock);
38 			return true;
39 		}
40 	}
41 	spin_unlock(&ses->chan_lock);
42 	return false;
43 }
44 
45 /* channel helper functions. assumed that chan_lock is held by caller. */
46 
47 int
cifs_ses_get_chan_index(struct cifs_ses * ses,struct TCP_Server_Info * server)48 cifs_ses_get_chan_index(struct cifs_ses *ses,
49 			struct TCP_Server_Info *server)
50 {
51 	unsigned int i;
52 
53 	/* if the channel is waiting for termination */
54 	if (server && server->terminate)
55 		return CIFS_INVAL_CHAN_INDEX;
56 
57 	for (i = 0; i < ses->chan_count; i++) {
58 		if (ses->chans[i].server == server)
59 			return i;
60 	}
61 
62 	/* If we didn't find the channel, it is likely a bug */
63 	if (server)
64 		cifs_dbg(VFS, "unable to get chan index for server: 0x%llx",
65 			 server->conn_id);
66 	return CIFS_INVAL_CHAN_INDEX;
67 }
68 
69 void
cifs_chan_set_in_reconnect(struct cifs_ses * ses,struct TCP_Server_Info * server)70 cifs_chan_set_in_reconnect(struct cifs_ses *ses,
71 			     struct TCP_Server_Info *server)
72 {
73 	int chan_index = cifs_ses_get_chan_index(ses, server);
74 
75 	if (chan_index == CIFS_INVAL_CHAN_INDEX)
76 		return;
77 
78 	ses->chans[chan_index].in_reconnect = true;
79 }
80 
81 void
cifs_chan_clear_in_reconnect(struct cifs_ses * ses,struct TCP_Server_Info * server)82 cifs_chan_clear_in_reconnect(struct cifs_ses *ses,
83 			     struct TCP_Server_Info *server)
84 {
85 	unsigned int chan_index = cifs_ses_get_chan_index(ses, server);
86 
87 	if (chan_index == CIFS_INVAL_CHAN_INDEX)
88 		return;
89 
90 	ses->chans[chan_index].in_reconnect = false;
91 }
92 
93 void
cifs_chan_set_need_reconnect(struct cifs_ses * ses,struct TCP_Server_Info * server)94 cifs_chan_set_need_reconnect(struct cifs_ses *ses,
95 			     struct TCP_Server_Info *server)
96 {
97 	unsigned int chan_index = cifs_ses_get_chan_index(ses, server);
98 
99 	if (chan_index == CIFS_INVAL_CHAN_INDEX)
100 		return;
101 
102 	set_bit(chan_index, &ses->chans_need_reconnect);
103 	cifs_dbg(FYI, "Set reconnect bitmask for chan %u; now 0x%lx\n",
104 		 chan_index, ses->chans_need_reconnect);
105 }
106 
107 void
cifs_chan_clear_need_reconnect(struct cifs_ses * ses,struct TCP_Server_Info * server)108 cifs_chan_clear_need_reconnect(struct cifs_ses *ses,
109 			       struct TCP_Server_Info *server)
110 {
111 	unsigned int chan_index = cifs_ses_get_chan_index(ses, server);
112 
113 	if (chan_index == CIFS_INVAL_CHAN_INDEX)
114 		return;
115 
116 	clear_bit(chan_index, &ses->chans_need_reconnect);
117 	cifs_dbg(FYI, "Cleared reconnect bitmask for chan %u; now 0x%lx\n",
118 		 chan_index, ses->chans_need_reconnect);
119 }
120 
121 bool
cifs_chan_needs_reconnect(struct cifs_ses * ses,struct TCP_Server_Info * server)122 cifs_chan_needs_reconnect(struct cifs_ses *ses,
123 			  struct TCP_Server_Info *server)
124 {
125 	unsigned int chan_index = cifs_ses_get_chan_index(ses, server);
126 
127 	if (chan_index == CIFS_INVAL_CHAN_INDEX)
128 		return true;	/* err on the safer side */
129 
130 	return CIFS_CHAN_NEEDS_RECONNECT(ses, chan_index);
131 }
132 
133 bool
cifs_chan_is_iface_active(struct cifs_ses * ses,struct TCP_Server_Info * server)134 cifs_chan_is_iface_active(struct cifs_ses *ses,
135 			  struct TCP_Server_Info *server)
136 {
137 	unsigned int chan_index = cifs_ses_get_chan_index(ses, server);
138 
139 	if (chan_index == CIFS_INVAL_CHAN_INDEX)
140 		return true;	/* err on the safer side */
141 
142 	return ses->chans[chan_index].iface &&
143 		ses->chans[chan_index].iface->is_active;
144 }
145 
146 /* returns number of channels added */
cifs_try_adding_channels(struct cifs_ses * ses)147 int cifs_try_adding_channels(struct cifs_ses *ses)
148 {
149 	struct TCP_Server_Info *server = ses->server;
150 	int old_chan_count, new_chan_count;
151 	int left;
152 	int rc = 0;
153 	int tries = 0;
154 	size_t iface_weight = 0, iface_min_speed = 0;
155 	struct cifs_server_iface *iface = NULL, *niface = NULL;
156 	struct cifs_server_iface *last_iface = NULL;
157 
158 	spin_lock(&ses->chan_lock);
159 
160 	new_chan_count = old_chan_count = ses->chan_count;
161 	left = ses->chan_max - ses->chan_count;
162 
163 	if (left <= 0) {
164 		spin_unlock(&ses->chan_lock);
165 		cifs_dbg(FYI,
166 			 "ses already at max_channels (%zu), nothing to open\n",
167 			 ses->chan_max);
168 		return 0;
169 	}
170 
171 	if (server->dialect < SMB30_PROT_ID) {
172 		spin_unlock(&ses->chan_lock);
173 		cifs_dbg(VFS, "multichannel is not supported on this protocol version, use 3.0 or above\n");
174 		return 0;
175 	}
176 
177 	if (!(server->capabilities & SMB2_GLOBAL_CAP_MULTI_CHANNEL)) {
178 		spin_unlock(&ses->chan_lock);
179 		cifs_server_dbg(VFS, "no multichannel support\n");
180 		return 0;
181 	}
182 	spin_unlock(&ses->chan_lock);
183 
184 	while (left > 0) {
185 
186 		tries++;
187 		if (tries > 3*ses->chan_max) {
188 			cifs_dbg(VFS, "too many channel open attempts (%d channels left to open)\n",
189 				 left);
190 			break;
191 		}
192 
193 		spin_lock(&ses->iface_lock);
194 		if (!ses->iface_count) {
195 			spin_unlock(&ses->iface_lock);
196 			cifs_dbg(ONCE, "server %s does not advertise interfaces\n",
197 				      ses->server->hostname);
198 			break;
199 		}
200 
201 		if (!iface)
202 			iface = list_first_entry(&ses->iface_list, struct cifs_server_iface,
203 						 iface_head);
204 		last_iface = list_last_entry(&ses->iface_list, struct cifs_server_iface,
205 					     iface_head);
206 		iface_min_speed = last_iface->speed;
207 
208 		list_for_each_entry_safe_from(iface, niface, &ses->iface_list,
209 				    iface_head) {
210 			/* do not mix rdma and non-rdma interfaces */
211 			if (iface->rdma_capable != ses->server->rdma)
212 				continue;
213 
214 			/* skip ifaces that are unusable */
215 			if (!iface->is_active ||
216 			    (is_ses_using_iface(ses, iface) &&
217 			     !iface->rss_capable))
218 				continue;
219 
220 			/* check if we already allocated enough channels */
221 			iface_weight = iface->speed / iface_min_speed;
222 
223 			if (iface->weight_fulfilled >= iface_weight)
224 				continue;
225 
226 			/* take ref before unlock */
227 			kref_get(&iface->refcount);
228 
229 			spin_unlock(&ses->iface_lock);
230 			rc = cifs_ses_add_channel(ses, iface);
231 			spin_lock(&ses->iface_lock);
232 
233 			if (rc) {
234 				cifs_dbg(VFS, "failed to open extra channel on iface:%pIS rc=%d\n",
235 					 &iface->sockaddr,
236 					 rc);
237 				kref_put(&iface->refcount, release_iface);
238 				/* failure to add chan should increase weight */
239 				iface->weight_fulfilled++;
240 				continue;
241 			}
242 
243 			iface->num_channels++;
244 			iface->weight_fulfilled++;
245 			cifs_info("successfully opened new channel on iface:%pIS\n",
246 				 &iface->sockaddr);
247 			break;
248 		}
249 
250 		/* reached end of list. reset weight_fulfilled and start over */
251 		if (list_entry_is_head(iface, &ses->iface_list, iface_head)) {
252 			list_for_each_entry(iface, &ses->iface_list, iface_head)
253 				iface->weight_fulfilled = 0;
254 			spin_unlock(&ses->iface_lock);
255 			iface = NULL;
256 			continue;
257 		}
258 		spin_unlock(&ses->iface_lock);
259 
260 		left--;
261 		new_chan_count++;
262 	}
263 
264 	return new_chan_count - old_chan_count;
265 }
266 
267 /*
268  * called when multichannel is disabled by the server.
269  * this always gets called from smb2_reconnect
270  * and cannot get called in parallel threads.
271  */
272 void
cifs_disable_secondary_channels(struct cifs_ses * ses)273 cifs_disable_secondary_channels(struct cifs_ses *ses)
274 {
275 	int i, chan_count;
276 	struct TCP_Server_Info *server;
277 	struct cifs_server_iface *iface;
278 
279 	spin_lock(&ses->chan_lock);
280 	chan_count = ses->chan_count;
281 	if (chan_count == 1)
282 		goto done;
283 
284 	ses->chan_count = 1;
285 
286 	/* for all secondary channels reset the need reconnect bit */
287 	ses->chans_need_reconnect &= 1;
288 
289 	for (i = 1; i < chan_count; i++) {
290 		iface = ses->chans[i].iface;
291 		server = ses->chans[i].server;
292 
293 		/*
294 		 * remove these references first, since we need to unlock
295 		 * the chan_lock here, since iface_lock is a higher lock
296 		 */
297 		ses->chans[i].iface = NULL;
298 		ses->chans[i].server = NULL;
299 		spin_unlock(&ses->chan_lock);
300 
301 		if (iface) {
302 			spin_lock(&ses->iface_lock);
303 			iface->num_channels--;
304 			if (iface->weight_fulfilled)
305 				iface->weight_fulfilled--;
306 			kref_put(&iface->refcount, release_iface);
307 			spin_unlock(&ses->iface_lock);
308 		}
309 
310 		if (server) {
311 			if (!server->terminate) {
312 				server->terminate = true;
313 				cifs_signal_cifsd_for_reconnect(server, false);
314 			}
315 			cifs_put_tcp_session(server, false);
316 		}
317 
318 		spin_lock(&ses->chan_lock);
319 	}
320 
321 done:
322 	spin_unlock(&ses->chan_lock);
323 }
324 
325 /* update the iface for the channel if necessary. */
326 void
cifs_chan_update_iface(struct cifs_ses * ses,struct TCP_Server_Info * server)327 cifs_chan_update_iface(struct cifs_ses *ses, struct TCP_Server_Info *server)
328 {
329 	unsigned int chan_index;
330 	size_t iface_weight = 0, iface_min_speed = 0;
331 	struct cifs_server_iface *iface = NULL;
332 	struct cifs_server_iface *old_iface = NULL;
333 	struct cifs_server_iface *last_iface = NULL;
334 	struct sockaddr_storage ss;
335 	int retry = 0;
336 
337 	spin_lock(&ses->chan_lock);
338 	chan_index = cifs_ses_get_chan_index(ses, server);
339 	if (chan_index == CIFS_INVAL_CHAN_INDEX) {
340 		spin_unlock(&ses->chan_lock);
341 		return;
342 	}
343 
344 	if (ses->chans[chan_index].iface) {
345 		old_iface = ses->chans[chan_index].iface;
346 		if (old_iface->is_active) {
347 			spin_unlock(&ses->chan_lock);
348 			return;
349 		}
350 	}
351 	spin_unlock(&ses->chan_lock);
352 
353 	spin_lock(&server->srv_lock);
354 	ss = server->dstaddr;
355 	spin_unlock(&server->srv_lock);
356 
357 	spin_lock(&ses->iface_lock);
358 	if (!ses->iface_count) {
359 		spin_unlock(&ses->iface_lock);
360 		cifs_dbg(ONCE, "server %s does not advertise interfaces\n", ses->server->hostname);
361 		return;
362 	}
363 
364 try_again:
365 	last_iface = list_last_entry(&ses->iface_list, struct cifs_server_iface,
366 				     iface_head);
367 	iface_min_speed = last_iface->speed;
368 
369 	/* then look for a new one */
370 	list_for_each_entry(iface, &ses->iface_list, iface_head) {
371 		if (!chan_index) {
372 			/* if we're trying to get the updated iface for primary channel */
373 			if (!cifs_match_ipaddr((struct sockaddr *) &ss,
374 					       (struct sockaddr *) &iface->sockaddr))
375 				continue;
376 
377 			kref_get(&iface->refcount);
378 			break;
379 		}
380 
381 		/* do not mix rdma and non-rdma interfaces */
382 		if (iface->rdma_capable != server->rdma)
383 			continue;
384 
385 		if (!iface->is_active ||
386 		    (is_ses_using_iface(ses, iface) &&
387 		     !iface->rss_capable)) {
388 			continue;
389 		}
390 
391 		/* check if we already allocated enough channels */
392 		iface_weight = iface->speed / iface_min_speed;
393 
394 		if (iface->weight_fulfilled >= iface_weight)
395 			continue;
396 
397 		kref_get(&iface->refcount);
398 		break;
399 	}
400 
401 	if (list_entry_is_head(iface, &ses->iface_list, iface_head)) {
402 		list_for_each_entry(iface, &ses->iface_list, iface_head)
403 			iface->weight_fulfilled = 0;
404 
405 		/* see if it can be satisfied in second attempt */
406 		if (!retry++)
407 			goto try_again;
408 
409 		iface = NULL;
410 		cifs_dbg(FYI, "unable to find a suitable iface\n");
411 	}
412 
413 	if (!iface) {
414 		if (!chan_index)
415 			cifs_dbg(FYI, "unable to get the interface matching: %pIS\n",
416 				 &ss);
417 		else {
418 			cifs_dbg(FYI, "unable to find another interface to replace: %pIS\n",
419 				 &old_iface->sockaddr);
420 		}
421 
422 		spin_unlock(&ses->iface_lock);
423 		return;
424 	}
425 
426 	/* now drop the ref to the current iface */
427 	if (old_iface) {
428 		cifs_dbg(FYI, "replacing iface: %pIS with %pIS\n",
429 			 &old_iface->sockaddr,
430 			 &iface->sockaddr);
431 
432 		old_iface->num_channels--;
433 		if (old_iface->weight_fulfilled)
434 			old_iface->weight_fulfilled--;
435 		iface->num_channels++;
436 		iface->weight_fulfilled++;
437 
438 		kref_put(&old_iface->refcount, release_iface);
439 	} else if (!chan_index) {
440 		/* special case: update interface for primary channel */
441 		cifs_dbg(FYI, "referencing primary channel iface: %pIS\n",
442 			 &iface->sockaddr);
443 		iface->num_channels++;
444 		iface->weight_fulfilled++;
445 	}
446 	spin_unlock(&ses->iface_lock);
447 
448 	spin_lock(&ses->chan_lock);
449 	chan_index = cifs_ses_get_chan_index(ses, server);
450 	if (chan_index == CIFS_INVAL_CHAN_INDEX) {
451 		spin_unlock(&ses->chan_lock);
452 		return;
453 	}
454 
455 	ses->chans[chan_index].iface = iface;
456 	spin_unlock(&ses->chan_lock);
457 
458 	spin_lock(&server->srv_lock);
459 	memcpy(&server->dstaddr, &iface->sockaddr, sizeof(server->dstaddr));
460 	spin_unlock(&server->srv_lock);
461 }
462 
463 static int
cifs_ses_add_channel(struct cifs_ses * ses,struct cifs_server_iface * iface)464 cifs_ses_add_channel(struct cifs_ses *ses,
465 		     struct cifs_server_iface *iface)
466 {
467 	struct TCP_Server_Info *chan_server;
468 	struct cifs_chan *chan;
469 	struct smb3_fs_context *ctx;
470 	static const char unc_fmt[] = "\\%s\\foo";
471 	struct sockaddr_in *ipv4 = (struct sockaddr_in *)&iface->sockaddr;
472 	struct sockaddr_in6 *ipv6 = (struct sockaddr_in6 *)&iface->sockaddr;
473 	size_t len;
474 	int rc;
475 	unsigned int xid = get_xid();
476 
477 	if (iface->sockaddr.ss_family == AF_INET)
478 		cifs_dbg(FYI, "adding channel to ses %p (speed:%zu bps rdma:%s ip:%pI4)\n",
479 			 ses, iface->speed, str_yes_no(iface->rdma_capable),
480 			 &ipv4->sin_addr);
481 	else
482 		cifs_dbg(FYI, "adding channel to ses %p (speed:%zu bps rdma:%s ip:%pI6)\n",
483 			 ses, iface->speed, str_yes_no(iface->rdma_capable),
484 			 &ipv6->sin6_addr);
485 
486 	/*
487 	 * Setup a ctx with mostly the same info as the existing
488 	 * session and overwrite it with the requested iface data.
489 	 *
490 	 * We need to setup at least the fields used for negprot and
491 	 * sesssetup.
492 	 *
493 	 * We only need the ctx here, so we can reuse memory from
494 	 * the session and server without caring about memory
495 	 * management.
496 	 */
497 	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
498 	if (!ctx) {
499 		rc = -ENOMEM;
500 		goto out_free_xid;
501 	}
502 
503 	/* Always make new connection for now (TODO?) */
504 	ctx->nosharesock = true;
505 
506 	/* Auth */
507 	ctx->domainauto = ses->domainAuto;
508 	ctx->domainname = ses->domainName;
509 
510 	ctx->server_hostname = ses->server->hostname;
511 
512 	ctx->username = ses->user_name;
513 	ctx->password = ses->password;
514 	ctx->sectype = ses->sectype;
515 	ctx->sign = ses->sign;
516 	ctx->unicode = ses->unicode;
517 
518 	/* UNC and paths */
519 	/* XXX: Use ses->server->hostname? */
520 	len = sizeof(unc_fmt) + SERVER_NAME_LEN_WITH_NULL;
521 	ctx->UNC = kzalloc(len, GFP_KERNEL);
522 	if (!ctx->UNC) {
523 		rc = -ENOMEM;
524 		goto out_free_ctx;
525 	}
526 	scnprintf(ctx->UNC, len, unc_fmt, ses->ip_addr);
527 	ctx->prepath = "";
528 
529 	/* Reuse same version as master connection */
530 	ctx->vals = ses->server->vals;
531 	ctx->ops = ses->server->ops;
532 
533 	ctx->noblocksnd = ses->server->noblocksnd;
534 	ctx->noautotune = ses->server->noautotune;
535 	ctx->sockopt_tcp_nodelay = ses->server->tcp_nodelay;
536 	ctx->echo_interval = ses->server->echo_interval / HZ;
537 	ctx->max_credits = ses->server->max_credits;
538 	ctx->min_offload = ses->server->min_offload;
539 	ctx->compress = ses->server->compression.requested;
540 	ctx->dfs_conn = ses->server->dfs_conn;
541 	ctx->ignore_signature = ses->server->ignore_signature;
542 	ctx->leaf_fullpath = ses->server->leaf_fullpath;
543 	ctx->rootfs = ses->server->noblockcnt;
544 	ctx->retrans = ses->server->retrans;
545 
546 	/*
547 	 * This will be used for encoding/decoding user/domain/pw
548 	 * during sess setup auth.
549 	 */
550 	ctx->local_nls = ses->local_nls;
551 
552 	/* Use RDMA if possible */
553 	ctx->rdma = iface->rdma_capable;
554 	memcpy(&ctx->dstaddr, &iface->sockaddr, sizeof(ctx->dstaddr));
555 
556 	/* reuse master con client guid */
557 	memcpy(&ctx->client_guid, ses->server->client_guid,
558 	       sizeof(ctx->client_guid));
559 	ctx->use_client_guid = true;
560 
561 	chan_server = cifs_get_tcp_session(ctx, ses->server);
562 
563 	spin_lock(&ses->chan_lock);
564 	chan = &ses->chans[ses->chan_count];
565 	chan->server = chan_server;
566 	if (IS_ERR(chan->server)) {
567 		rc = PTR_ERR(chan->server);
568 		chan->server = NULL;
569 		spin_unlock(&ses->chan_lock);
570 		goto out;
571 	}
572 	chan->iface = iface;
573 	ses->chan_count++;
574 	atomic_set(&ses->chan_seq, 0);
575 
576 	/* Mark this channel as needing connect/setup */
577 	cifs_chan_set_need_reconnect(ses, chan->server);
578 
579 	spin_unlock(&ses->chan_lock);
580 
581 	mutex_lock(&ses->session_mutex);
582 	/*
583 	 * We need to allocate the server crypto now as we will need
584 	 * to sign packets before we generate the channel signing key
585 	 * (we sign with the session key)
586 	 */
587 	rc = smb311_crypto_shash_allocate(chan->server);
588 	if (rc) {
589 		cifs_dbg(VFS, "%s: crypto alloc failed\n", __func__);
590 		mutex_unlock(&ses->session_mutex);
591 		goto out;
592 	}
593 
594 	rc = cifs_negotiate_protocol(xid, ses, chan->server);
595 	if (!rc)
596 		rc = cifs_setup_session(xid, ses, chan->server, ses->local_nls);
597 
598 	mutex_unlock(&ses->session_mutex);
599 
600 out:
601 	if (rc && chan->server) {
602 		cifs_put_tcp_session(chan->server, 0);
603 
604 		spin_lock(&ses->chan_lock);
605 
606 		/* we rely on all bits beyond chan_count to be clear */
607 		cifs_chan_clear_need_reconnect(ses, chan->server);
608 		ses->chan_count--;
609 		/*
610 		 * chan_count should never reach 0 as at least the primary
611 		 * channel is always allocated
612 		 */
613 		WARN_ON(ses->chan_count < 1);
614 		spin_unlock(&ses->chan_lock);
615 	}
616 
617 	kfree(ctx->UNC);
618 out_free_ctx:
619 	kfree(ctx);
620 out_free_xid:
621 	free_xid(xid);
622 	return rc;
623 }
624 
625 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
cifs_ssetup_hdr(struct cifs_ses * ses,struct TCP_Server_Info * server,SESSION_SETUP_ANDX * pSMB)626 static __u32 cifs_ssetup_hdr(struct cifs_ses *ses,
627 			     struct TCP_Server_Info *server,
628 			     SESSION_SETUP_ANDX *pSMB)
629 {
630 	__u32 capabilities = 0;
631 
632 	/* init fields common to all four types of SessSetup */
633 	/* Note that offsets for first seven fields in req struct are same  */
634 	/*	in CIFS Specs so does not matter which of 3 forms of struct */
635 	/*	that we use in next few lines                               */
636 	/* Note that header is initialized to zero in header_assemble */
637 	pSMB->req.AndXCommand = 0xFF;
638 	pSMB->req.MaxBufferSize = cpu_to_le16(min_t(u32,
639 					CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4,
640 					USHRT_MAX));
641 	pSMB->req.MaxMpxCount = cpu_to_le16(server->maxReq);
642 	pSMB->req.VcNumber = cpu_to_le16(1);
643 	pSMB->req.SessionKey = server->session_key_id;
644 
645 	/* Now no need to set SMBFLG_CASELESS or obsolete CANONICAL PATH */
646 
647 	/* BB verify whether signing required on neg or just auth frame (and NTLM case) */
648 
649 	capabilities = CAP_LARGE_FILES | CAP_NT_SMBS | CAP_LEVEL_II_OPLOCKS |
650 			CAP_LARGE_WRITE_X | CAP_LARGE_READ_X;
651 
652 	if (server->sign)
653 		pSMB->req.hdr.Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
654 
655 	if (ses->capabilities & CAP_UNICODE) {
656 		pSMB->req.hdr.Flags2 |= SMBFLG2_UNICODE;
657 		capabilities |= CAP_UNICODE;
658 	}
659 	if (ses->capabilities & CAP_STATUS32) {
660 		pSMB->req.hdr.Flags2 |= SMBFLG2_ERR_STATUS;
661 		capabilities |= CAP_STATUS32;
662 	}
663 	if (ses->capabilities & CAP_DFS) {
664 		pSMB->req.hdr.Flags2 |= SMBFLG2_DFS;
665 		capabilities |= CAP_DFS;
666 	}
667 	if (ses->capabilities & CAP_UNIX)
668 		capabilities |= CAP_UNIX;
669 
670 	return capabilities;
671 }
672 
673 static void
unicode_oslm_strings(char ** pbcc_area,const struct nls_table * nls_cp)674 unicode_oslm_strings(char **pbcc_area, const struct nls_table *nls_cp)
675 {
676 	char *bcc_ptr = *pbcc_area;
677 	int bytes_ret = 0;
678 
679 	/* Copy OS version */
680 	bytes_ret = cifs_strtoUTF16((__le16 *)bcc_ptr, "Linux version ", 32,
681 				    nls_cp);
682 	bcc_ptr += 2 * bytes_ret;
683 	bytes_ret = cifs_strtoUTF16((__le16 *) bcc_ptr, init_utsname()->release,
684 				    32, nls_cp);
685 	bcc_ptr += 2 * bytes_ret;
686 	bcc_ptr += 2; /* trailing null */
687 
688 	bytes_ret = cifs_strtoUTF16((__le16 *) bcc_ptr, CIFS_NETWORK_OPSYS,
689 				    32, nls_cp);
690 	bcc_ptr += 2 * bytes_ret;
691 	bcc_ptr += 2; /* trailing null */
692 
693 	*pbcc_area = bcc_ptr;
694 }
695 
696 static void
ascii_oslm_strings(char ** pbcc_area,const struct nls_table * nls_cp)697 ascii_oslm_strings(char **pbcc_area, const struct nls_table *nls_cp)
698 {
699 	char *bcc_ptr = *pbcc_area;
700 
701 	strcpy(bcc_ptr, "Linux version ");
702 	bcc_ptr += strlen("Linux version ");
703 	strcpy(bcc_ptr, init_utsname()->release);
704 	bcc_ptr += strlen(init_utsname()->release) + 1;
705 
706 	strcpy(bcc_ptr, CIFS_NETWORK_OPSYS);
707 	bcc_ptr += strlen(CIFS_NETWORK_OPSYS) + 1;
708 
709 	*pbcc_area = bcc_ptr;
710 }
711 
unicode_domain_string(char ** pbcc_area,struct cifs_ses * ses,const struct nls_table * nls_cp)712 static void unicode_domain_string(char **pbcc_area, struct cifs_ses *ses,
713 				   const struct nls_table *nls_cp)
714 {
715 	char *bcc_ptr = *pbcc_area;
716 	int bytes_ret = 0;
717 
718 	/* copy domain */
719 	if (ses->domainName == NULL) {
720 		/*
721 		 * Sending null domain better than using a bogus domain name (as
722 		 * we did briefly in 2.6.18) since server will use its default
723 		 */
724 		*bcc_ptr = 0;
725 		*(bcc_ptr+1) = 0;
726 		bytes_ret = 0;
727 	} else
728 		bytes_ret = cifs_strtoUTF16((__le16 *) bcc_ptr, ses->domainName,
729 					    CIFS_MAX_DOMAINNAME_LEN, nls_cp);
730 	bcc_ptr += 2 * bytes_ret;
731 	bcc_ptr += 2;  /* account for null terminator */
732 
733 	*pbcc_area = bcc_ptr;
734 }
735 
ascii_domain_string(char ** pbcc_area,struct cifs_ses * ses,const struct nls_table * nls_cp)736 static void ascii_domain_string(char **pbcc_area, struct cifs_ses *ses,
737 				const struct nls_table *nls_cp)
738 {
739 	char *bcc_ptr = *pbcc_area;
740 	int len;
741 
742 	/* copy domain */
743 	if (ses->domainName != NULL) {
744 		len = strscpy(bcc_ptr, ses->domainName, CIFS_MAX_DOMAINNAME_LEN);
745 		if (WARN_ON_ONCE(len < 0))
746 			len = CIFS_MAX_DOMAINNAME_LEN - 1;
747 		bcc_ptr += len;
748 	} /* else we send a null domain name so server will default to its own domain */
749 	*bcc_ptr = 0;
750 	bcc_ptr++;
751 
752 	*pbcc_area = bcc_ptr;
753 }
754 
unicode_ssetup_strings(char ** pbcc_area,struct cifs_ses * ses,const struct nls_table * nls_cp)755 static void unicode_ssetup_strings(char **pbcc_area, struct cifs_ses *ses,
756 				   const struct nls_table *nls_cp)
757 {
758 	char *bcc_ptr = *pbcc_area;
759 	int bytes_ret = 0;
760 
761 	/* BB FIXME add check that strings less than 335 or will need to send as arrays */
762 
763 	/* copy user */
764 	if (ses->user_name == NULL) {
765 		/* null user mount */
766 		*bcc_ptr = 0;
767 		*(bcc_ptr+1) = 0;
768 	} else {
769 		bytes_ret = cifs_strtoUTF16((__le16 *) bcc_ptr, ses->user_name,
770 					    CIFS_MAX_USERNAME_LEN, nls_cp);
771 	}
772 	bcc_ptr += 2 * bytes_ret;
773 	bcc_ptr += 2; /* account for null termination */
774 
775 	unicode_domain_string(&bcc_ptr, ses, nls_cp);
776 	unicode_oslm_strings(&bcc_ptr, nls_cp);
777 
778 	*pbcc_area = bcc_ptr;
779 }
780 
ascii_ssetup_strings(char ** pbcc_area,struct cifs_ses * ses,const struct nls_table * nls_cp)781 static void ascii_ssetup_strings(char **pbcc_area, struct cifs_ses *ses,
782 				 const struct nls_table *nls_cp)
783 {
784 	char *bcc_ptr = *pbcc_area;
785 	int len;
786 
787 	/* copy user */
788 	/* BB what about null user mounts - check that we do this BB */
789 	/* copy user */
790 	if (ses->user_name != NULL) {
791 		len = strscpy(bcc_ptr, ses->user_name, CIFS_MAX_USERNAME_LEN);
792 		if (WARN_ON_ONCE(len < 0))
793 			len = CIFS_MAX_USERNAME_LEN - 1;
794 		bcc_ptr += len;
795 	}
796 	/* else null user mount */
797 	*bcc_ptr = 0;
798 	bcc_ptr++; /* account for null termination */
799 
800 	/* BB check for overflow here */
801 
802 	ascii_domain_string(&bcc_ptr, ses, nls_cp);
803 	ascii_oslm_strings(&bcc_ptr, nls_cp);
804 
805 	*pbcc_area = bcc_ptr;
806 }
807 
808 static void
decode_unicode_ssetup(char ** pbcc_area,int bleft,struct cifs_ses * ses,const struct nls_table * nls_cp)809 decode_unicode_ssetup(char **pbcc_area, int bleft, struct cifs_ses *ses,
810 		      const struct nls_table *nls_cp)
811 {
812 	int len;
813 	char *data = *pbcc_area;
814 
815 	cifs_dbg(FYI, "bleft %d\n", bleft);
816 
817 	kfree(ses->serverOS);
818 	ses->serverOS = cifs_strndup_from_utf16(data, bleft, true, nls_cp);
819 	cifs_dbg(FYI, "serverOS=%s\n", ses->serverOS);
820 	len = (UniStrnlen((wchar_t *) data, bleft / 2) * 2) + 2;
821 	data += len;
822 	bleft -= len;
823 	if (bleft <= 0)
824 		return;
825 
826 	kfree(ses->serverNOS);
827 	ses->serverNOS = cifs_strndup_from_utf16(data, bleft, true, nls_cp);
828 	cifs_dbg(FYI, "serverNOS=%s\n", ses->serverNOS);
829 	len = (UniStrnlen((wchar_t *) data, bleft / 2) * 2) + 2;
830 	data += len;
831 	bleft -= len;
832 	if (bleft <= 0)
833 		return;
834 
835 	kfree(ses->serverDomain);
836 	ses->serverDomain = cifs_strndup_from_utf16(data, bleft, true, nls_cp);
837 	cifs_dbg(FYI, "serverDomain=%s\n", ses->serverDomain);
838 
839 	return;
840 }
841 
decode_ascii_ssetup(char ** pbcc_area,__u16 bleft,struct cifs_ses * ses,const struct nls_table * nls_cp)842 static void decode_ascii_ssetup(char **pbcc_area, __u16 bleft,
843 				struct cifs_ses *ses,
844 				const struct nls_table *nls_cp)
845 {
846 	int len;
847 	char *bcc_ptr = *pbcc_area;
848 
849 	cifs_dbg(FYI, "decode sessetup ascii. bleft %d\n", bleft);
850 
851 	len = strnlen(bcc_ptr, bleft);
852 	if (len >= bleft)
853 		return;
854 
855 	kfree(ses->serverOS);
856 
857 	ses->serverOS = kmalloc(len + 1, GFP_KERNEL);
858 	if (ses->serverOS) {
859 		memcpy(ses->serverOS, bcc_ptr, len);
860 		ses->serverOS[len] = 0;
861 		if (strncmp(ses->serverOS, "OS/2", 4) == 0)
862 			cifs_dbg(FYI, "OS/2 server\n");
863 	}
864 
865 	bcc_ptr += len + 1;
866 	bleft -= len + 1;
867 
868 	len = strnlen(bcc_ptr, bleft);
869 	if (len >= bleft)
870 		return;
871 
872 	kfree(ses->serverNOS);
873 
874 	ses->serverNOS = kmalloc(len + 1, GFP_KERNEL);
875 	if (ses->serverNOS) {
876 		memcpy(ses->serverNOS, bcc_ptr, len);
877 		ses->serverNOS[len] = 0;
878 	}
879 
880 	bcc_ptr += len + 1;
881 	bleft -= len + 1;
882 
883 	len = strnlen(bcc_ptr, bleft);
884 	if (len > bleft)
885 		return;
886 
887 	/*
888 	 * No domain field in LANMAN case. Domain is
889 	 * returned by old servers in the SMB negprot response
890 	 *
891 	 * BB For newer servers which do not support Unicode,
892 	 * but thus do return domain here, we could add parsing
893 	 * for it later, but it is not very important
894 	 */
895 	cifs_dbg(FYI, "ascii: bytes left %d\n", bleft);
896 }
897 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
898 
decode_ntlmssp_challenge(char * bcc_ptr,int blob_len,struct cifs_ses * ses)899 int decode_ntlmssp_challenge(char *bcc_ptr, int blob_len,
900 				    struct cifs_ses *ses)
901 {
902 	unsigned int tioffset; /* challenge message target info area */
903 	unsigned int tilen; /* challenge message target info area length  */
904 	CHALLENGE_MESSAGE *pblob = (CHALLENGE_MESSAGE *)bcc_ptr;
905 	__u32 server_flags;
906 
907 	if (blob_len < sizeof(CHALLENGE_MESSAGE)) {
908 		cifs_dbg(VFS, "challenge blob len %d too small\n", blob_len);
909 		return -EINVAL;
910 	}
911 
912 	if (memcmp(pblob->Signature, "NTLMSSP", 8)) {
913 		cifs_dbg(VFS, "blob signature incorrect %s\n",
914 			 pblob->Signature);
915 		return -EINVAL;
916 	}
917 	if (pblob->MessageType != NtLmChallenge) {
918 		cifs_dbg(VFS, "Incorrect message type %d\n",
919 			 pblob->MessageType);
920 		return -EINVAL;
921 	}
922 
923 	server_flags = le32_to_cpu(pblob->NegotiateFlags);
924 	cifs_dbg(FYI, "%s: negotiate=0x%08x challenge=0x%08x\n", __func__,
925 		 ses->ntlmssp->client_flags, server_flags);
926 
927 	if ((ses->ntlmssp->client_flags & (NTLMSSP_NEGOTIATE_SEAL | NTLMSSP_NEGOTIATE_SIGN)) &&
928 	    (!(server_flags & NTLMSSP_NEGOTIATE_56) && !(server_flags & NTLMSSP_NEGOTIATE_128))) {
929 		cifs_dbg(VFS, "%s: requested signing/encryption but server did not return either 56-bit or 128-bit session key size\n",
930 			 __func__);
931 		return -EINVAL;
932 	}
933 	if (!(server_flags & NTLMSSP_NEGOTIATE_NTLM) && !(server_flags & NTLMSSP_NEGOTIATE_EXTENDED_SEC)) {
934 		cifs_dbg(VFS, "%s: server does not seem to support either NTLMv1 or NTLMv2\n", __func__);
935 		return -EINVAL;
936 	}
937 	if (ses->server->sign && !(server_flags & NTLMSSP_NEGOTIATE_SIGN)) {
938 		cifs_dbg(VFS, "%s: forced packet signing but server does not seem to support it\n",
939 			 __func__);
940 		return -EOPNOTSUPP;
941 	}
942 	if ((ses->ntlmssp->client_flags & NTLMSSP_NEGOTIATE_KEY_XCH) &&
943 	    !(server_flags & NTLMSSP_NEGOTIATE_KEY_XCH))
944 		pr_warn_once("%s: authentication has been weakened as server does not support key exchange\n",
945 			     __func__);
946 
947 	ses->ntlmssp->server_flags = server_flags;
948 
949 	memcpy(ses->ntlmssp->cryptkey, pblob->Challenge, CIFS_CRYPTO_KEY_SIZE);
950 	/*
951 	 * In particular we can examine sign flags
952 	 *
953 	 * BB spec says that if AvId field of MsvAvTimestamp is populated then
954 	 * we must set the MIC field of the AUTHENTICATE_MESSAGE
955 	 */
956 
957 	tioffset = le32_to_cpu(pblob->TargetInfoArray.BufferOffset);
958 	tilen = le16_to_cpu(pblob->TargetInfoArray.Length);
959 	if (tioffset > blob_len || tioffset + tilen > blob_len) {
960 		cifs_dbg(VFS, "tioffset + tilen too high %u + %u\n",
961 			 tioffset, tilen);
962 		return -EINVAL;
963 	}
964 	if (tilen) {
965 		kfree_sensitive(ses->auth_key.response);
966 		ses->auth_key.response = kmemdup(bcc_ptr + tioffset, tilen,
967 						 GFP_KERNEL);
968 		if (!ses->auth_key.response) {
969 			cifs_dbg(VFS, "Challenge target info alloc failure\n");
970 			return -ENOMEM;
971 		}
972 		ses->auth_key.len = tilen;
973 	}
974 
975 	return 0;
976 }
977 
size_of_ntlmssp_blob(struct cifs_ses * ses,int base_size)978 static int size_of_ntlmssp_blob(struct cifs_ses *ses, int base_size)
979 {
980 	int sz = base_size + ses->auth_key.len
981 		- CIFS_SESS_KEY_SIZE + CIFS_CPHTXT_SIZE + 2;
982 
983 	if (ses->domainName)
984 		sz += sizeof(__le16) * strnlen(ses->domainName, CIFS_MAX_DOMAINNAME_LEN);
985 	else
986 		sz += sizeof(__le16);
987 
988 	if (ses->user_name)
989 		sz += sizeof(__le16) * strnlen(ses->user_name, CIFS_MAX_USERNAME_LEN);
990 	else
991 		sz += sizeof(__le16);
992 
993 	if (ses->workstation_name[0])
994 		sz += sizeof(__le16) * strnlen(ses->workstation_name,
995 					       ntlmssp_workstation_name_size(ses));
996 	else
997 		sz += sizeof(__le16);
998 
999 	return sz;
1000 }
1001 
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)1002 static inline void cifs_security_buffer_from_str(SECURITY_BUFFER *pbuf,
1003 						 char *str_value,
1004 						 int str_length,
1005 						 unsigned char *pstart,
1006 						 unsigned char **pcur,
1007 						 const struct nls_table *nls_cp)
1008 {
1009 	unsigned char *tmp = pstart;
1010 	int len;
1011 
1012 	if (!pbuf)
1013 		return;
1014 
1015 	if (!pcur)
1016 		pcur = &tmp;
1017 
1018 	if (!str_value) {
1019 		pbuf->BufferOffset = cpu_to_le32(*pcur - pstart);
1020 		pbuf->Length = 0;
1021 		pbuf->MaximumLength = 0;
1022 		*pcur += sizeof(__le16);
1023 	} else {
1024 		len = cifs_strtoUTF16((__le16 *)*pcur,
1025 				      str_value,
1026 				      str_length,
1027 				      nls_cp);
1028 		len *= sizeof(__le16);
1029 		pbuf->BufferOffset = cpu_to_le32(*pcur - pstart);
1030 		pbuf->Length = cpu_to_le16(len);
1031 		pbuf->MaximumLength = cpu_to_le16(len);
1032 		*pcur += len;
1033 	}
1034 }
1035 
1036 /* BB Move to ntlmssp.c eventually */
1037 
build_ntlmssp_negotiate_blob(unsigned char ** pbuffer,u16 * buflen,struct cifs_ses * ses,struct TCP_Server_Info * server,const struct nls_table * nls_cp)1038 int build_ntlmssp_negotiate_blob(unsigned char **pbuffer,
1039 				 u16 *buflen,
1040 				 struct cifs_ses *ses,
1041 				 struct TCP_Server_Info *server,
1042 				 const struct nls_table *nls_cp)
1043 {
1044 	int rc = 0;
1045 	NEGOTIATE_MESSAGE *sec_blob;
1046 	__u32 flags;
1047 	unsigned char *tmp;
1048 	int len;
1049 
1050 	len = size_of_ntlmssp_blob(ses, sizeof(NEGOTIATE_MESSAGE));
1051 	*pbuffer = kmalloc(len, GFP_KERNEL);
1052 	if (!*pbuffer) {
1053 		rc = -ENOMEM;
1054 		cifs_dbg(VFS, "Error %d during NTLMSSP allocation\n", rc);
1055 		*buflen = 0;
1056 		goto setup_ntlm_neg_ret;
1057 	}
1058 	sec_blob = (NEGOTIATE_MESSAGE *)*pbuffer;
1059 
1060 	memset(*pbuffer, 0, sizeof(NEGOTIATE_MESSAGE));
1061 	memcpy(sec_blob->Signature, NTLMSSP_SIGNATURE, 8);
1062 	sec_blob->MessageType = NtLmNegotiate;
1063 
1064 	/* BB is NTLMV2 session security format easier to use here? */
1065 	flags = NTLMSSP_NEGOTIATE_56 |	NTLMSSP_REQUEST_TARGET |
1066 		NTLMSSP_NEGOTIATE_128 | NTLMSSP_NEGOTIATE_UNICODE |
1067 		NTLMSSP_NEGOTIATE_NTLM | NTLMSSP_NEGOTIATE_EXTENDED_SEC |
1068 		NTLMSSP_NEGOTIATE_ALWAYS_SIGN | NTLMSSP_NEGOTIATE_SEAL |
1069 		NTLMSSP_NEGOTIATE_SIGN;
1070 	if (!server->session_estab || ses->ntlmssp->sesskey_per_smbsess)
1071 		flags |= NTLMSSP_NEGOTIATE_KEY_XCH;
1072 
1073 	tmp = *pbuffer + sizeof(NEGOTIATE_MESSAGE);
1074 	ses->ntlmssp->client_flags = flags;
1075 	sec_blob->NegotiateFlags = cpu_to_le32(flags);
1076 
1077 	/* these fields should be null in negotiate phase MS-NLMP 3.1.5.1.1 */
1078 	cifs_security_buffer_from_str(&sec_blob->DomainName,
1079 				      NULL,
1080 				      CIFS_MAX_DOMAINNAME_LEN,
1081 				      *pbuffer, &tmp,
1082 				      nls_cp);
1083 
1084 	cifs_security_buffer_from_str(&sec_blob->WorkstationName,
1085 				      NULL,
1086 				      CIFS_MAX_WORKSTATION_LEN,
1087 				      *pbuffer, &tmp,
1088 				      nls_cp);
1089 
1090 	*buflen = tmp - *pbuffer;
1091 setup_ntlm_neg_ret:
1092 	return rc;
1093 }
1094 
1095 /*
1096  * Build ntlmssp blob with additional fields, such as version,
1097  * supported by modern servers. For safety limit to SMB3 or later
1098  * See notes in MS-NLMP Section 2.2.2.1 e.g.
1099  */
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)1100 int build_ntlmssp_smb3_negotiate_blob(unsigned char **pbuffer,
1101 				 u16 *buflen,
1102 				 struct cifs_ses *ses,
1103 				 struct TCP_Server_Info *server,
1104 				 const struct nls_table *nls_cp)
1105 {
1106 	int rc = 0;
1107 	struct negotiate_message *sec_blob;
1108 	__u32 flags;
1109 	unsigned char *tmp;
1110 	int len;
1111 
1112 	len = size_of_ntlmssp_blob(ses, sizeof(struct negotiate_message));
1113 	*pbuffer = kmalloc(len, GFP_KERNEL);
1114 	if (!*pbuffer) {
1115 		rc = -ENOMEM;
1116 		cifs_dbg(VFS, "Error %d during NTLMSSP allocation\n", rc);
1117 		*buflen = 0;
1118 		goto setup_ntlm_smb3_neg_ret;
1119 	}
1120 	sec_blob = (struct negotiate_message *)*pbuffer;
1121 
1122 	memset(*pbuffer, 0, sizeof(struct negotiate_message));
1123 	memcpy(sec_blob->Signature, NTLMSSP_SIGNATURE, 8);
1124 	sec_blob->MessageType = NtLmNegotiate;
1125 
1126 	/* BB is NTLMV2 session security format easier to use here? */
1127 	flags = NTLMSSP_NEGOTIATE_56 |	NTLMSSP_REQUEST_TARGET |
1128 		NTLMSSP_NEGOTIATE_128 | NTLMSSP_NEGOTIATE_UNICODE |
1129 		NTLMSSP_NEGOTIATE_NTLM | NTLMSSP_NEGOTIATE_EXTENDED_SEC |
1130 		NTLMSSP_NEGOTIATE_ALWAYS_SIGN | NTLMSSP_NEGOTIATE_SEAL |
1131 		NTLMSSP_NEGOTIATE_SIGN | NTLMSSP_NEGOTIATE_VERSION;
1132 	if (!server->session_estab || ses->ntlmssp->sesskey_per_smbsess)
1133 		flags |= NTLMSSP_NEGOTIATE_KEY_XCH;
1134 
1135 	sec_blob->Version.ProductMajorVersion = LINUX_VERSION_MAJOR;
1136 	sec_blob->Version.ProductMinorVersion = LINUX_VERSION_PATCHLEVEL;
1137 	sec_blob->Version.ProductBuild = cpu_to_le16(SMB3_PRODUCT_BUILD);
1138 	sec_blob->Version.NTLMRevisionCurrent = NTLMSSP_REVISION_W2K3;
1139 
1140 	tmp = *pbuffer + sizeof(struct negotiate_message);
1141 	ses->ntlmssp->client_flags = flags;
1142 	sec_blob->NegotiateFlags = cpu_to_le32(flags);
1143 
1144 	/* these fields should be null in negotiate phase MS-NLMP 3.1.5.1.1 */
1145 	cifs_security_buffer_from_str(&sec_blob->DomainName,
1146 				      NULL,
1147 				      CIFS_MAX_DOMAINNAME_LEN,
1148 				      *pbuffer, &tmp,
1149 				      nls_cp);
1150 
1151 	cifs_security_buffer_from_str(&sec_blob->WorkstationName,
1152 				      NULL,
1153 				      CIFS_MAX_WORKSTATION_LEN,
1154 				      *pbuffer, &tmp,
1155 				      nls_cp);
1156 
1157 	*buflen = tmp - *pbuffer;
1158 setup_ntlm_smb3_neg_ret:
1159 	return rc;
1160 }
1161 
1162 
1163 /* 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)1164 int build_ntlmssp_auth_blob(unsigned char **pbuffer,
1165 					u16 *buflen,
1166 				   struct cifs_ses *ses,
1167 				   struct TCP_Server_Info *server,
1168 				   const struct nls_table *nls_cp)
1169 {
1170 	int rc;
1171 	AUTHENTICATE_MESSAGE *sec_blob;
1172 	__u32 flags;
1173 	unsigned char *tmp;
1174 	int len;
1175 
1176 	rc = setup_ntlmv2_rsp(ses, nls_cp);
1177 	if (rc) {
1178 		cifs_dbg(VFS, "Error %d during NTLMSSP authentication\n", rc);
1179 		*buflen = 0;
1180 		goto setup_ntlmv2_ret;
1181 	}
1182 
1183 	len = size_of_ntlmssp_blob(ses, sizeof(AUTHENTICATE_MESSAGE));
1184 	*pbuffer = kmalloc(len, GFP_KERNEL);
1185 	if (!*pbuffer) {
1186 		rc = -ENOMEM;
1187 		cifs_dbg(VFS, "Error %d during NTLMSSP allocation\n", rc);
1188 		*buflen = 0;
1189 		goto setup_ntlmv2_ret;
1190 	}
1191 	sec_blob = (AUTHENTICATE_MESSAGE *)*pbuffer;
1192 
1193 	memcpy(sec_blob->Signature, NTLMSSP_SIGNATURE, 8);
1194 	sec_blob->MessageType = NtLmAuthenticate;
1195 
1196 	/* send version information in ntlmssp authenticate also */
1197 	flags = ses->ntlmssp->server_flags | NTLMSSP_REQUEST_TARGET |
1198 		NTLMSSP_NEGOTIATE_TARGET_INFO | NTLMSSP_NEGOTIATE_VERSION |
1199 		NTLMSSP_NEGOTIATE_WORKSTATION_SUPPLIED;
1200 
1201 	sec_blob->Version.ProductMajorVersion = LINUX_VERSION_MAJOR;
1202 	sec_blob->Version.ProductMinorVersion = LINUX_VERSION_PATCHLEVEL;
1203 	sec_blob->Version.ProductBuild = cpu_to_le16(SMB3_PRODUCT_BUILD);
1204 	sec_blob->Version.NTLMRevisionCurrent = NTLMSSP_REVISION_W2K3;
1205 
1206 	tmp = *pbuffer + sizeof(AUTHENTICATE_MESSAGE);
1207 	sec_blob->NegotiateFlags = cpu_to_le32(flags);
1208 
1209 	sec_blob->LmChallengeResponse.BufferOffset =
1210 				cpu_to_le32(sizeof(AUTHENTICATE_MESSAGE));
1211 	sec_blob->LmChallengeResponse.Length = 0;
1212 	sec_blob->LmChallengeResponse.MaximumLength = 0;
1213 
1214 	sec_blob->NtChallengeResponse.BufferOffset =
1215 				cpu_to_le32(tmp - *pbuffer);
1216 	if (ses->user_name != NULL) {
1217 		memcpy(tmp, ses->auth_key.response + CIFS_SESS_KEY_SIZE,
1218 				ses->auth_key.len - CIFS_SESS_KEY_SIZE);
1219 		tmp += ses->auth_key.len - CIFS_SESS_KEY_SIZE;
1220 
1221 		sec_blob->NtChallengeResponse.Length =
1222 				cpu_to_le16(ses->auth_key.len - CIFS_SESS_KEY_SIZE);
1223 		sec_blob->NtChallengeResponse.MaximumLength =
1224 				cpu_to_le16(ses->auth_key.len - CIFS_SESS_KEY_SIZE);
1225 	} else {
1226 		/*
1227 		 * don't send an NT Response for anonymous access
1228 		 */
1229 		sec_blob->NtChallengeResponse.Length = 0;
1230 		sec_blob->NtChallengeResponse.MaximumLength = 0;
1231 	}
1232 
1233 	cifs_security_buffer_from_str(&sec_blob->DomainName,
1234 				      ses->domainName,
1235 				      CIFS_MAX_DOMAINNAME_LEN,
1236 				      *pbuffer, &tmp,
1237 				      nls_cp);
1238 
1239 	cifs_security_buffer_from_str(&sec_blob->UserName,
1240 				      ses->user_name,
1241 				      CIFS_MAX_USERNAME_LEN,
1242 				      *pbuffer, &tmp,
1243 				      nls_cp);
1244 
1245 	cifs_security_buffer_from_str(&sec_blob->WorkstationName,
1246 				      ses->workstation_name,
1247 				      ntlmssp_workstation_name_size(ses),
1248 				      *pbuffer, &tmp,
1249 				      nls_cp);
1250 
1251 	if ((ses->ntlmssp->server_flags & NTLMSSP_NEGOTIATE_KEY_XCH) &&
1252 	    (!ses->server->session_estab || ses->ntlmssp->sesskey_per_smbsess) &&
1253 	    !calc_seckey(ses)) {
1254 		memcpy(tmp, ses->ntlmssp->ciphertext, CIFS_CPHTXT_SIZE);
1255 		sec_blob->SessionKey.BufferOffset = cpu_to_le32(tmp - *pbuffer);
1256 		sec_blob->SessionKey.Length = cpu_to_le16(CIFS_CPHTXT_SIZE);
1257 		sec_blob->SessionKey.MaximumLength =
1258 				cpu_to_le16(CIFS_CPHTXT_SIZE);
1259 		tmp += CIFS_CPHTXT_SIZE;
1260 	} else {
1261 		sec_blob->SessionKey.BufferOffset = cpu_to_le32(tmp - *pbuffer);
1262 		sec_blob->SessionKey.Length = 0;
1263 		sec_blob->SessionKey.MaximumLength = 0;
1264 	}
1265 
1266 	*buflen = tmp - *pbuffer;
1267 setup_ntlmv2_ret:
1268 	return rc;
1269 }
1270 
1271 enum securityEnum
cifs_select_sectype(struct TCP_Server_Info * server,enum securityEnum requested)1272 cifs_select_sectype(struct TCP_Server_Info *server, enum securityEnum requested)
1273 {
1274 	switch (server->negflavor) {
1275 	case CIFS_NEGFLAVOR_EXTENDED:
1276 		switch (requested) {
1277 		case Kerberos:
1278 		case RawNTLMSSP:
1279 		case IAKerb:
1280 			return requested;
1281 		case Unspecified:
1282 			if (server->sec_ntlmssp &&
1283 			    (global_secflags & CIFSSEC_MAY_NTLMSSP))
1284 				return RawNTLMSSP;
1285 			if ((server->sec_kerberos || server->sec_mskerberos || server->sec_iakerb) &&
1286 			    (global_secflags & CIFSSEC_MAY_KRB5))
1287 				return Kerberos;
1288 			fallthrough;
1289 		default:
1290 			return Unspecified;
1291 		}
1292 	case CIFS_NEGFLAVOR_UNENCAP:
1293 		switch (requested) {
1294 		case NTLMv2:
1295 			return requested;
1296 		case Unspecified:
1297 			if (global_secflags & CIFSSEC_MAY_NTLMV2)
1298 				return NTLMv2;
1299 			break;
1300 		default:
1301 			break;
1302 		}
1303 		fallthrough;
1304 	default:
1305 		return Unspecified;
1306 	}
1307 }
1308 
1309 struct sess_data {
1310 	unsigned int xid;
1311 	struct cifs_ses *ses;
1312 	struct TCP_Server_Info *server;
1313 	struct nls_table *nls_cp;
1314 	void (*func)(struct sess_data *);
1315 	int result;
1316 
1317 	/* we will send the SMB in three pieces:
1318 	 * a fixed length beginning part, an optional
1319 	 * SPNEGO blob (which can be zero length), and a
1320 	 * last part which will include the strings
1321 	 * and rest of bcc area. This allows us to avoid
1322 	 * a large buffer 17K allocation
1323 	 */
1324 	int buf0_type;
1325 	struct kvec iov[3];
1326 };
1327 
1328 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
1329 static int
sess_alloc_buffer(struct sess_data * sess_data,int wct)1330 sess_alloc_buffer(struct sess_data *sess_data, int wct)
1331 {
1332 	int rc;
1333 	struct cifs_ses *ses = sess_data->ses;
1334 	struct smb_hdr *smb_buf;
1335 
1336 	rc = small_smb_init_no_tc(SMB_COM_SESSION_SETUP_ANDX, wct, ses,
1337 				  (void **)&smb_buf);
1338 
1339 	if (rc)
1340 		return rc;
1341 
1342 	sess_data->iov[0].iov_base = (char *)smb_buf;
1343 	sess_data->iov[0].iov_len = be32_to_cpu(smb_buf->smb_buf_length) + 4;
1344 	/*
1345 	 * This variable will be used to clear the buffer
1346 	 * allocated above in case of any error in the calling function.
1347 	 */
1348 	sess_data->buf0_type = CIFS_SMALL_BUFFER;
1349 
1350 	/* 2000 big enough to fit max user, domain, NOS name etc. */
1351 	sess_data->iov[2].iov_base = kmalloc(2000, GFP_KERNEL);
1352 	if (!sess_data->iov[2].iov_base) {
1353 		rc = -ENOMEM;
1354 		goto out_free_smb_buf;
1355 	}
1356 
1357 	return 0;
1358 
1359 out_free_smb_buf:
1360 	cifs_small_buf_release(smb_buf);
1361 	sess_data->iov[0].iov_base = NULL;
1362 	sess_data->iov[0].iov_len = 0;
1363 	sess_data->buf0_type = CIFS_NO_BUFFER;
1364 	return rc;
1365 }
1366 
1367 static void
sess_free_buffer(struct sess_data * sess_data)1368 sess_free_buffer(struct sess_data *sess_data)
1369 {
1370 	struct kvec *iov = sess_data->iov;
1371 
1372 	/*
1373 	 * Zero the session data before freeing, as it might contain sensitive info (keys, etc).
1374 	 * Note that iov[1] is already freed by caller.
1375 	 */
1376 	if (sess_data->buf0_type != CIFS_NO_BUFFER && iov[0].iov_base)
1377 		memzero_explicit(iov[0].iov_base, iov[0].iov_len);
1378 
1379 	free_rsp_buf(sess_data->buf0_type, iov[0].iov_base);
1380 	sess_data->buf0_type = CIFS_NO_BUFFER;
1381 	kfree_sensitive(iov[2].iov_base);
1382 }
1383 
1384 static int
sess_establish_session(struct sess_data * sess_data)1385 sess_establish_session(struct sess_data *sess_data)
1386 {
1387 	struct cifs_ses *ses = sess_data->ses;
1388 	struct TCP_Server_Info *server = sess_data->server;
1389 
1390 	cifs_server_lock(server);
1391 	if (!server->session_estab) {
1392 		if (server->sign) {
1393 			server->session_key.response =
1394 				kmemdup(ses->auth_key.response,
1395 				ses->auth_key.len, GFP_KERNEL);
1396 			if (!server->session_key.response) {
1397 				cifs_server_unlock(server);
1398 				return -ENOMEM;
1399 			}
1400 			server->session_key.len =
1401 						ses->auth_key.len;
1402 		}
1403 		server->sequence_number = 0x2;
1404 		server->session_estab = true;
1405 	}
1406 	cifs_server_unlock(server);
1407 
1408 	cifs_dbg(FYI, "CIFS session established successfully\n");
1409 	return 0;
1410 }
1411 
1412 static int
sess_sendreceive(struct sess_data * sess_data)1413 sess_sendreceive(struct sess_data *sess_data)
1414 {
1415 	int rc;
1416 	struct smb_hdr *smb_buf = (struct smb_hdr *) sess_data->iov[0].iov_base;
1417 	__u16 count;
1418 	struct kvec rsp_iov = { NULL, 0 };
1419 
1420 	count = sess_data->iov[1].iov_len + sess_data->iov[2].iov_len;
1421 	be32_add_cpu(&smb_buf->smb_buf_length, count);
1422 	put_bcc(count, smb_buf);
1423 
1424 	rc = SendReceive2(sess_data->xid, sess_data->ses,
1425 			  sess_data->iov, 3 /* num_iovecs */,
1426 			  &sess_data->buf0_type,
1427 			  CIFS_LOG_ERROR, &rsp_iov);
1428 	cifs_small_buf_release(sess_data->iov[0].iov_base);
1429 	memcpy(&sess_data->iov[0], &rsp_iov, sizeof(struct kvec));
1430 
1431 	return rc;
1432 }
1433 
1434 static void
sess_auth_ntlmv2(struct sess_data * sess_data)1435 sess_auth_ntlmv2(struct sess_data *sess_data)
1436 {
1437 	int rc = 0;
1438 	struct smb_hdr *smb_buf;
1439 	SESSION_SETUP_ANDX *pSMB;
1440 	char *bcc_ptr;
1441 	struct cifs_ses *ses = sess_data->ses;
1442 	struct TCP_Server_Info *server = sess_data->server;
1443 	__u32 capabilities;
1444 	__u16 bytes_remaining;
1445 
1446 	/* old style NTLM sessionsetup */
1447 	/* wct = 13 */
1448 	rc = sess_alloc_buffer(sess_data, 13);
1449 	if (rc)
1450 		goto out;
1451 
1452 	pSMB = (SESSION_SETUP_ANDX *)sess_data->iov[0].iov_base;
1453 	bcc_ptr = sess_data->iov[2].iov_base;
1454 	capabilities = cifs_ssetup_hdr(ses, server, pSMB);
1455 
1456 	pSMB->req_no_secext.Capabilities = cpu_to_le32(capabilities);
1457 
1458 	/* LM2 password would be here if we supported it */
1459 	pSMB->req_no_secext.CaseInsensitivePasswordLength = 0;
1460 
1461 	if (ses->user_name != NULL) {
1462 		/* calculate nlmv2 response and session key */
1463 		rc = setup_ntlmv2_rsp(ses, sess_data->nls_cp);
1464 		if (rc) {
1465 			cifs_dbg(VFS, "Error %d during NTLMv2 authentication\n", rc);
1466 			goto out;
1467 		}
1468 
1469 		memcpy(bcc_ptr, ses->auth_key.response + CIFS_SESS_KEY_SIZE,
1470 				ses->auth_key.len - CIFS_SESS_KEY_SIZE);
1471 		bcc_ptr += ses->auth_key.len - CIFS_SESS_KEY_SIZE;
1472 
1473 		/* set case sensitive password length after tilen may get
1474 		 * assigned, tilen is 0 otherwise.
1475 		 */
1476 		pSMB->req_no_secext.CaseSensitivePasswordLength =
1477 			cpu_to_le16(ses->auth_key.len - CIFS_SESS_KEY_SIZE);
1478 	} else {
1479 		pSMB->req_no_secext.CaseSensitivePasswordLength = 0;
1480 	}
1481 
1482 	if (ses->capabilities & CAP_UNICODE) {
1483 		if (!IS_ALIGNED(sess_data->iov[0].iov_len, 2)) {
1484 			*bcc_ptr = 0;
1485 			bcc_ptr++;
1486 		}
1487 		unicode_ssetup_strings(&bcc_ptr, ses, sess_data->nls_cp);
1488 	} else {
1489 		ascii_ssetup_strings(&bcc_ptr, ses, sess_data->nls_cp);
1490 	}
1491 
1492 
1493 	sess_data->iov[2].iov_len = (long) bcc_ptr -
1494 			(long) sess_data->iov[2].iov_base;
1495 
1496 	rc = sess_sendreceive(sess_data);
1497 	if (rc)
1498 		goto out;
1499 
1500 	pSMB = (SESSION_SETUP_ANDX *)sess_data->iov[0].iov_base;
1501 	smb_buf = (struct smb_hdr *)sess_data->iov[0].iov_base;
1502 
1503 	if (smb_buf->WordCount != 3) {
1504 		rc = -EIO;
1505 		cifs_dbg(VFS, "bad word count %d\n", smb_buf->WordCount);
1506 		goto out;
1507 	}
1508 
1509 	if (le16_to_cpu(pSMB->resp.Action) & GUEST_LOGIN)
1510 		cifs_dbg(FYI, "Guest login\n"); /* BB mark SesInfo struct? */
1511 
1512 	ses->Suid = smb_buf->Uid;   /* UID left in wire format (le) */
1513 	cifs_dbg(FYI, "UID = %llu\n", ses->Suid);
1514 
1515 	bytes_remaining = get_bcc(smb_buf);
1516 	bcc_ptr = pByteArea(smb_buf);
1517 
1518 	/* BB check if Unicode and decode strings */
1519 	if (bytes_remaining == 0) {
1520 		/* no string area to decode, do nothing */
1521 	} else if (smb_buf->Flags2 & SMBFLG2_UNICODE) {
1522 		/* unicode string area must be word-aligned */
1523 		if (!IS_ALIGNED((unsigned long)bcc_ptr - (unsigned long)smb_buf, 2)) {
1524 			++bcc_ptr;
1525 			--bytes_remaining;
1526 		}
1527 		decode_unicode_ssetup(&bcc_ptr, bytes_remaining, ses,
1528 				      sess_data->nls_cp);
1529 	} else {
1530 		decode_ascii_ssetup(&bcc_ptr, bytes_remaining, ses,
1531 				    sess_data->nls_cp);
1532 	}
1533 
1534 	rc = sess_establish_session(sess_data);
1535 out:
1536 	sess_data->result = rc;
1537 	sess_data->func = NULL;
1538 	sess_free_buffer(sess_data);
1539 	kfree_sensitive(ses->auth_key.response);
1540 	ses->auth_key.response = NULL;
1541 }
1542 
1543 #ifdef CONFIG_CIFS_UPCALL
1544 static void
sess_auth_kerberos(struct sess_data * sess_data)1545 sess_auth_kerberos(struct sess_data *sess_data)
1546 {
1547 	int rc = 0;
1548 	struct smb_hdr *smb_buf;
1549 	SESSION_SETUP_ANDX *pSMB;
1550 	char *bcc_ptr;
1551 	struct cifs_ses *ses = sess_data->ses;
1552 	struct TCP_Server_Info *server = sess_data->server;
1553 	__u32 capabilities;
1554 	__u16 bytes_remaining;
1555 	struct key *spnego_key = NULL;
1556 	struct cifs_spnego_msg *msg;
1557 	u16 blob_len;
1558 
1559 	/* extended security */
1560 	/* wct = 12 */
1561 	rc = sess_alloc_buffer(sess_data, 12);
1562 	if (rc)
1563 		goto out;
1564 
1565 	pSMB = (SESSION_SETUP_ANDX *)sess_data->iov[0].iov_base;
1566 	bcc_ptr = sess_data->iov[2].iov_base;
1567 	capabilities = cifs_ssetup_hdr(ses, server, pSMB);
1568 
1569 	spnego_key = cifs_get_spnego_key(ses, server);
1570 	if (IS_ERR(spnego_key)) {
1571 		rc = PTR_ERR(spnego_key);
1572 		spnego_key = NULL;
1573 		goto out;
1574 	}
1575 
1576 	msg = spnego_key->payload.data[0];
1577 	/*
1578 	 * check version field to make sure that cifs.upcall is
1579 	 * sending us a response in an expected form
1580 	 */
1581 	if (msg->version != CIFS_SPNEGO_UPCALL_VERSION) {
1582 		cifs_dbg(VFS, "incorrect version of cifs.upcall (expected %d but got %d)\n",
1583 			 CIFS_SPNEGO_UPCALL_VERSION, msg->version);
1584 		rc = -EKEYREJECTED;
1585 		goto out_put_spnego_key;
1586 	}
1587 
1588 	kfree_sensitive(ses->auth_key.response);
1589 	ses->auth_key.response = kmemdup(msg->data, msg->sesskey_len,
1590 					 GFP_KERNEL);
1591 	if (!ses->auth_key.response) {
1592 		cifs_dbg(VFS, "Kerberos can't allocate (%u bytes) memory\n",
1593 			 msg->sesskey_len);
1594 		rc = -ENOMEM;
1595 		goto out_put_spnego_key;
1596 	}
1597 	ses->auth_key.len = msg->sesskey_len;
1598 
1599 	pSMB->req.hdr.Flags2 |= SMBFLG2_EXT_SEC;
1600 	capabilities |= CAP_EXTENDED_SECURITY;
1601 	pSMB->req.Capabilities = cpu_to_le32(capabilities);
1602 	sess_data->iov[1].iov_base = msg->data + msg->sesskey_len;
1603 	sess_data->iov[1].iov_len = msg->secblob_len;
1604 	pSMB->req.SecurityBlobLength = cpu_to_le16(sess_data->iov[1].iov_len);
1605 
1606 	if (pSMB->req.hdr.Flags2 & SMBFLG2_UNICODE) {
1607 		/* unicode strings must be word aligned */
1608 		if (!IS_ALIGNED(sess_data->iov[0].iov_len + sess_data->iov[1].iov_len, 2)) {
1609 			*bcc_ptr = 0;
1610 			bcc_ptr++;
1611 		}
1612 		unicode_oslm_strings(&bcc_ptr, sess_data->nls_cp);
1613 		unicode_domain_string(&bcc_ptr, ses, sess_data->nls_cp);
1614 	} else {
1615 		ascii_oslm_strings(&bcc_ptr, sess_data->nls_cp);
1616 		ascii_domain_string(&bcc_ptr, ses, sess_data->nls_cp);
1617 	}
1618 
1619 	sess_data->iov[2].iov_len = (long) bcc_ptr -
1620 			(long) sess_data->iov[2].iov_base;
1621 
1622 	rc = sess_sendreceive(sess_data);
1623 	if (rc)
1624 		goto out_put_spnego_key;
1625 
1626 	pSMB = (SESSION_SETUP_ANDX *)sess_data->iov[0].iov_base;
1627 	smb_buf = (struct smb_hdr *)sess_data->iov[0].iov_base;
1628 
1629 	if (smb_buf->WordCount != 4) {
1630 		rc = -EIO;
1631 		cifs_dbg(VFS, "bad word count %d\n", smb_buf->WordCount);
1632 		goto out_put_spnego_key;
1633 	}
1634 
1635 	if (le16_to_cpu(pSMB->resp.Action) & GUEST_LOGIN)
1636 		cifs_dbg(FYI, "Guest login\n"); /* BB mark SesInfo struct? */
1637 
1638 	ses->Suid = smb_buf->Uid;   /* UID left in wire format (le) */
1639 	cifs_dbg(FYI, "UID = %llu\n", ses->Suid);
1640 
1641 	bytes_remaining = get_bcc(smb_buf);
1642 	bcc_ptr = pByteArea(smb_buf);
1643 
1644 	blob_len = le16_to_cpu(pSMB->resp.SecurityBlobLength);
1645 	if (blob_len > bytes_remaining) {
1646 		cifs_dbg(VFS, "bad security blob length %d\n",
1647 				blob_len);
1648 		rc = -EINVAL;
1649 		goto out_put_spnego_key;
1650 	}
1651 	bcc_ptr += blob_len;
1652 	bytes_remaining -= blob_len;
1653 
1654 	/* BB check if Unicode and decode strings */
1655 	if (bytes_remaining == 0) {
1656 		/* no string area to decode, do nothing */
1657 	} else if (smb_buf->Flags2 & SMBFLG2_UNICODE) {
1658 		/* unicode string area must be word-aligned */
1659 		if (!IS_ALIGNED((unsigned long)bcc_ptr - (unsigned long)smb_buf, 2)) {
1660 			++bcc_ptr;
1661 			--bytes_remaining;
1662 		}
1663 		decode_unicode_ssetup(&bcc_ptr, bytes_remaining, ses,
1664 				      sess_data->nls_cp);
1665 	} else {
1666 		decode_ascii_ssetup(&bcc_ptr, bytes_remaining, ses,
1667 				    sess_data->nls_cp);
1668 	}
1669 
1670 	rc = sess_establish_session(sess_data);
1671 out_put_spnego_key:
1672 	key_invalidate(spnego_key);
1673 	key_put(spnego_key);
1674 out:
1675 	sess_data->result = rc;
1676 	sess_data->func = NULL;
1677 	sess_free_buffer(sess_data);
1678 	kfree_sensitive(ses->auth_key.response);
1679 	ses->auth_key.response = NULL;
1680 }
1681 
1682 #endif /* ! CONFIG_CIFS_UPCALL */
1683 
1684 /*
1685  * The required kvec buffers have to be allocated before calling this
1686  * function.
1687  */
1688 static int
_sess_auth_rawntlmssp_assemble_req(struct sess_data * sess_data)1689 _sess_auth_rawntlmssp_assemble_req(struct sess_data *sess_data)
1690 {
1691 	SESSION_SETUP_ANDX *pSMB;
1692 	struct cifs_ses *ses = sess_data->ses;
1693 	struct TCP_Server_Info *server = sess_data->server;
1694 	__u32 capabilities;
1695 	char *bcc_ptr;
1696 
1697 	pSMB = (SESSION_SETUP_ANDX *)sess_data->iov[0].iov_base;
1698 
1699 	capabilities = cifs_ssetup_hdr(ses, server, pSMB);
1700 	pSMB->req.hdr.Flags2 |= SMBFLG2_EXT_SEC;
1701 	capabilities |= CAP_EXTENDED_SECURITY;
1702 	pSMB->req.Capabilities |= cpu_to_le32(capabilities);
1703 
1704 	bcc_ptr = sess_data->iov[2].iov_base;
1705 
1706 	if (pSMB->req.hdr.Flags2 & SMBFLG2_UNICODE) {
1707 		/* unicode strings must be word aligned */
1708 		if (!IS_ALIGNED(sess_data->iov[0].iov_len + sess_data->iov[1].iov_len, 2)) {
1709 			*bcc_ptr = 0;
1710 			bcc_ptr++;
1711 		}
1712 		unicode_oslm_strings(&bcc_ptr, sess_data->nls_cp);
1713 	} else {
1714 		ascii_oslm_strings(&bcc_ptr, sess_data->nls_cp);
1715 	}
1716 
1717 	sess_data->iov[2].iov_len = (long) bcc_ptr -
1718 					(long) sess_data->iov[2].iov_base;
1719 
1720 	return 0;
1721 }
1722 
1723 static void
1724 sess_auth_rawntlmssp_authenticate(struct sess_data *sess_data);
1725 
1726 static void
sess_auth_rawntlmssp_negotiate(struct sess_data * sess_data)1727 sess_auth_rawntlmssp_negotiate(struct sess_data *sess_data)
1728 {
1729 	int rc;
1730 	struct smb_hdr *smb_buf;
1731 	SESSION_SETUP_ANDX *pSMB;
1732 	struct cifs_ses *ses = sess_data->ses;
1733 	struct TCP_Server_Info *server = sess_data->server;
1734 	__u16 bytes_remaining;
1735 	char *bcc_ptr;
1736 	unsigned char *ntlmsspblob = NULL;
1737 	u16 blob_len;
1738 
1739 	cifs_dbg(FYI, "rawntlmssp session setup negotiate phase\n");
1740 
1741 	/*
1742 	 * if memory allocation is successful, caller of this function
1743 	 * frees it.
1744 	 */
1745 	ses->ntlmssp = kmalloc(sizeof(struct ntlmssp_auth), GFP_KERNEL);
1746 	if (!ses->ntlmssp) {
1747 		rc = -ENOMEM;
1748 		goto out;
1749 	}
1750 	ses->ntlmssp->sesskey_per_smbsess = false;
1751 
1752 	/* wct = 12 */
1753 	rc = sess_alloc_buffer(sess_data, 12);
1754 	if (rc)
1755 		goto out;
1756 
1757 	pSMB = (SESSION_SETUP_ANDX *)sess_data->iov[0].iov_base;
1758 
1759 	/* Build security blob before we assemble the request */
1760 	rc = build_ntlmssp_negotiate_blob(&ntlmsspblob,
1761 				     &blob_len, ses, server,
1762 				     sess_data->nls_cp);
1763 	if (rc)
1764 		goto out_free_ntlmsspblob;
1765 
1766 	sess_data->iov[1].iov_len = blob_len;
1767 	sess_data->iov[1].iov_base = ntlmsspblob;
1768 	pSMB->req.SecurityBlobLength = cpu_to_le16(blob_len);
1769 
1770 	rc = _sess_auth_rawntlmssp_assemble_req(sess_data);
1771 	if (rc)
1772 		goto out_free_ntlmsspblob;
1773 
1774 	rc = sess_sendreceive(sess_data);
1775 
1776 	pSMB = (SESSION_SETUP_ANDX *)sess_data->iov[0].iov_base;
1777 	smb_buf = (struct smb_hdr *)sess_data->iov[0].iov_base;
1778 
1779 	/* If true, rc here is expected and not an error */
1780 	if (sess_data->buf0_type != CIFS_NO_BUFFER &&
1781 	    smb_buf->Status.CifsError ==
1782 			cpu_to_le32(NT_STATUS_MORE_PROCESSING_REQUIRED))
1783 		rc = 0;
1784 
1785 	if (rc)
1786 		goto out_free_ntlmsspblob;
1787 
1788 	cifs_dbg(FYI, "rawntlmssp session setup challenge phase\n");
1789 
1790 	if (smb_buf->WordCount != 4) {
1791 		rc = -EIO;
1792 		cifs_dbg(VFS, "bad word count %d\n", smb_buf->WordCount);
1793 		goto out_free_ntlmsspblob;
1794 	}
1795 
1796 	ses->Suid = smb_buf->Uid;   /* UID left in wire format (le) */
1797 	cifs_dbg(FYI, "UID = %llu\n", ses->Suid);
1798 
1799 	bytes_remaining = get_bcc(smb_buf);
1800 	bcc_ptr = pByteArea(smb_buf);
1801 
1802 	blob_len = le16_to_cpu(pSMB->resp.SecurityBlobLength);
1803 	if (blob_len > bytes_remaining) {
1804 		cifs_dbg(VFS, "bad security blob length %d\n",
1805 				blob_len);
1806 		rc = -EINVAL;
1807 		goto out_free_ntlmsspblob;
1808 	}
1809 
1810 	rc = decode_ntlmssp_challenge(bcc_ptr, blob_len, ses);
1811 
1812 out_free_ntlmsspblob:
1813 	kfree_sensitive(ntlmsspblob);
1814 out:
1815 	sess_free_buffer(sess_data);
1816 
1817 	if (!rc) {
1818 		sess_data->func = sess_auth_rawntlmssp_authenticate;
1819 		return;
1820 	}
1821 
1822 	/* Else error. Cleanup */
1823 	kfree_sensitive(ses->auth_key.response);
1824 	ses->auth_key.response = NULL;
1825 	kfree_sensitive(ses->ntlmssp);
1826 	ses->ntlmssp = NULL;
1827 
1828 	sess_data->func = NULL;
1829 	sess_data->result = rc;
1830 }
1831 
1832 static void
sess_auth_rawntlmssp_authenticate(struct sess_data * sess_data)1833 sess_auth_rawntlmssp_authenticate(struct sess_data *sess_data)
1834 {
1835 	int rc;
1836 	struct smb_hdr *smb_buf;
1837 	SESSION_SETUP_ANDX *pSMB;
1838 	struct cifs_ses *ses = sess_data->ses;
1839 	struct TCP_Server_Info *server = sess_data->server;
1840 	__u16 bytes_remaining;
1841 	char *bcc_ptr;
1842 	unsigned char *ntlmsspblob = NULL;
1843 	u16 blob_len;
1844 
1845 	cifs_dbg(FYI, "rawntlmssp session setup authenticate phase\n");
1846 
1847 	/* wct = 12 */
1848 	rc = sess_alloc_buffer(sess_data, 12);
1849 	if (rc)
1850 		goto out;
1851 
1852 	/* Build security blob before we assemble the request */
1853 	pSMB = (SESSION_SETUP_ANDX *)sess_data->iov[0].iov_base;
1854 	smb_buf = (struct smb_hdr *)pSMB;
1855 	rc = build_ntlmssp_auth_blob(&ntlmsspblob,
1856 					&blob_len, ses, server,
1857 					sess_data->nls_cp);
1858 	if (rc)
1859 		goto out_free_ntlmsspblob;
1860 	sess_data->iov[1].iov_len = blob_len;
1861 	sess_data->iov[1].iov_base = ntlmsspblob;
1862 	pSMB->req.SecurityBlobLength = cpu_to_le16(blob_len);
1863 	/*
1864 	 * Make sure that we tell the server that we are using
1865 	 * the uid that it just gave us back on the response
1866 	 * (challenge)
1867 	 */
1868 	smb_buf->Uid = ses->Suid;
1869 
1870 	rc = _sess_auth_rawntlmssp_assemble_req(sess_data);
1871 	if (rc)
1872 		goto out_free_ntlmsspblob;
1873 
1874 	rc = sess_sendreceive(sess_data);
1875 	if (rc)
1876 		goto out_free_ntlmsspblob;
1877 
1878 	pSMB = (SESSION_SETUP_ANDX *)sess_data->iov[0].iov_base;
1879 	smb_buf = (struct smb_hdr *)sess_data->iov[0].iov_base;
1880 	if (smb_buf->WordCount != 4) {
1881 		rc = -EIO;
1882 		cifs_dbg(VFS, "bad word count %d\n", smb_buf->WordCount);
1883 		goto out_free_ntlmsspblob;
1884 	}
1885 
1886 	if (le16_to_cpu(pSMB->resp.Action) & GUEST_LOGIN)
1887 		cifs_dbg(FYI, "Guest login\n"); /* BB mark SesInfo struct? */
1888 
1889 	if (ses->Suid != smb_buf->Uid) {
1890 		ses->Suid = smb_buf->Uid;
1891 		cifs_dbg(FYI, "UID changed! new UID = %llu\n", ses->Suid);
1892 	}
1893 
1894 	bytes_remaining = get_bcc(smb_buf);
1895 	bcc_ptr = pByteArea(smb_buf);
1896 	blob_len = le16_to_cpu(pSMB->resp.SecurityBlobLength);
1897 	if (blob_len > bytes_remaining) {
1898 		cifs_dbg(VFS, "bad security blob length %d\n",
1899 				blob_len);
1900 		rc = -EINVAL;
1901 		goto out_free_ntlmsspblob;
1902 	}
1903 	bcc_ptr += blob_len;
1904 	bytes_remaining -= blob_len;
1905 
1906 
1907 	/* BB check if Unicode and decode strings */
1908 	if (bytes_remaining == 0) {
1909 		/* no string area to decode, do nothing */
1910 	} else if (smb_buf->Flags2 & SMBFLG2_UNICODE) {
1911 		/* unicode string area must be word-aligned */
1912 		if (!IS_ALIGNED((unsigned long)bcc_ptr - (unsigned long)smb_buf, 2)) {
1913 			++bcc_ptr;
1914 			--bytes_remaining;
1915 		}
1916 		decode_unicode_ssetup(&bcc_ptr, bytes_remaining, ses,
1917 				      sess_data->nls_cp);
1918 	} else {
1919 		decode_ascii_ssetup(&bcc_ptr, bytes_remaining, ses,
1920 				    sess_data->nls_cp);
1921 	}
1922 
1923 out_free_ntlmsspblob:
1924 	kfree_sensitive(ntlmsspblob);
1925 out:
1926 	sess_free_buffer(sess_data);
1927 
1928 	if (!rc)
1929 		rc = sess_establish_session(sess_data);
1930 
1931 	/* Cleanup */
1932 	kfree_sensitive(ses->auth_key.response);
1933 	ses->auth_key.response = NULL;
1934 	kfree_sensitive(ses->ntlmssp);
1935 	ses->ntlmssp = NULL;
1936 
1937 	sess_data->func = NULL;
1938 	sess_data->result = rc;
1939 }
1940 
select_sec(struct sess_data * sess_data)1941 static int select_sec(struct sess_data *sess_data)
1942 {
1943 	int type;
1944 	struct cifs_ses *ses = sess_data->ses;
1945 	struct TCP_Server_Info *server = sess_data->server;
1946 
1947 	type = cifs_select_sectype(server, ses->sectype);
1948 	cifs_dbg(FYI, "sess setup type %d\n", type);
1949 	if (type == Unspecified) {
1950 		cifs_dbg(VFS, "Unable to select appropriate authentication method!\n");
1951 		return -EINVAL;
1952 	}
1953 
1954 	switch (type) {
1955 	case NTLMv2:
1956 		sess_data->func = sess_auth_ntlmv2;
1957 		break;
1958 	case Kerberos:
1959 #ifdef CONFIG_CIFS_UPCALL
1960 		sess_data->func = sess_auth_kerberos;
1961 		break;
1962 #else
1963 		cifs_dbg(VFS, "Kerberos negotiated but upcall support disabled!\n");
1964 		return -ENOSYS;
1965 #endif /* CONFIG_CIFS_UPCALL */
1966 	case RawNTLMSSP:
1967 		sess_data->func = sess_auth_rawntlmssp_negotiate;
1968 		break;
1969 	default:
1970 		cifs_dbg(VFS, "secType %d not supported!\n", type);
1971 		return -ENOSYS;
1972 	}
1973 
1974 	return 0;
1975 }
1976 
CIFS_SessSetup(const unsigned int xid,struct cifs_ses * ses,struct TCP_Server_Info * server,const struct nls_table * nls_cp)1977 int CIFS_SessSetup(const unsigned int xid, struct cifs_ses *ses,
1978 		   struct TCP_Server_Info *server,
1979 		   const struct nls_table *nls_cp)
1980 {
1981 	int rc = 0;
1982 	struct sess_data *sess_data;
1983 
1984 	if (ses == NULL) {
1985 		WARN(1, "%s: ses == NULL!", __func__);
1986 		return -EINVAL;
1987 	}
1988 
1989 	sess_data = kzalloc(sizeof(struct sess_data), GFP_KERNEL);
1990 	if (!sess_data)
1991 		return -ENOMEM;
1992 
1993 	sess_data->xid = xid;
1994 	sess_data->ses = ses;
1995 	sess_data->server = server;
1996 	sess_data->buf0_type = CIFS_NO_BUFFER;
1997 	sess_data->nls_cp = (struct nls_table *) nls_cp;
1998 
1999 	rc = select_sec(sess_data);
2000 	if (rc)
2001 		goto out;
2002 
2003 	while (sess_data->func)
2004 		sess_data->func(sess_data);
2005 
2006 	/* Store result before we free sess_data */
2007 	rc = sess_data->result;
2008 
2009 out:
2010 	kfree_sensitive(sess_data);
2011 	return rc;
2012 }
2013 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
2014