xref: /linux/fs/smb/client/sess.c (revision dec5a519e60e0ac3d273e441478ab7520d6dc3e5)
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 "cifsglob.h"
12 #include "cifsproto.h"
13 #include "cifs_unicode.h"
14 #include "cifs_debug.h"
15 #include "ntlmssp.h"
16 #include "nterr.h"
17 #include <linux/utsname.h>
18 #include <linux/slab.h>
19 #include <linux/version.h>
20 #include "cifsfs.h"
21 #include "cifs_spnego.h"
22 #include "smb2proto.h"
23 #include "fs_context.h"
24 
25 static int
26 cifs_ses_add_channel(struct cifs_ses *ses,
27 		     struct cifs_server_iface *iface);
28 
29 bool is_ses_using_iface(struct cifs_ses *ses, struct cifs_server_iface *iface)
30 {
31 	int i;
32 
33 	spin_lock(&ses->chan_lock);
34 	for (i = 0; i < ses->chan_count; i++) {
35 		if (ses->chans[i].iface == iface) {
36 			spin_unlock(&ses->chan_lock);
37 			return true;
38 		}
39 	}
40 	spin_unlock(&ses->chan_lock);
41 	return false;
42 }
43 
44 /* channel helper functions. assumed that chan_lock is held by caller. */
45 
46 int
47 cifs_ses_get_chan_index(struct cifs_ses *ses,
48 			struct TCP_Server_Info *server)
49 {
50 	unsigned int i;
51 
52 	/* if the channel is waiting for termination */
53 	if (server && server->terminate)
54 		return CIFS_INVAL_CHAN_INDEX;
55 
56 	for (i = 0; i < ses->chan_count; i++) {
57 		if (ses->chans[i].server == server)
58 			return i;
59 	}
60 
61 	/* If we didn't find the channel, it is likely a bug */
62 	if (server)
63 		cifs_dbg(VFS, "unable to get chan index for server: 0x%llx",
64 			 server->conn_id);
65 	return CIFS_INVAL_CHAN_INDEX;
66 }
67 
68 void
69 cifs_chan_set_in_reconnect(struct cifs_ses *ses,
70 			     struct TCP_Server_Info *server)
71 {
72 	int chan_index = cifs_ses_get_chan_index(ses, server);
73 
74 	if (chan_index == CIFS_INVAL_CHAN_INDEX)
75 		return;
76 
77 	ses->chans[chan_index].in_reconnect = true;
78 }
79 
80 void
81 cifs_chan_clear_in_reconnect(struct cifs_ses *ses,
82 			     struct TCP_Server_Info *server)
83 {
84 	unsigned int chan_index = cifs_ses_get_chan_index(ses, server);
85 
86 	if (chan_index == CIFS_INVAL_CHAN_INDEX)
87 		return;
88 
89 	ses->chans[chan_index].in_reconnect = false;
90 }
91 
92 void
93 cifs_chan_set_need_reconnect(struct cifs_ses *ses,
94 			     struct TCP_Server_Info *server)
95 {
96 	unsigned int chan_index = cifs_ses_get_chan_index(ses, server);
97 
98 	if (chan_index == CIFS_INVAL_CHAN_INDEX)
99 		return;
100 
101 	set_bit(chan_index, &ses->chans_need_reconnect);
102 	cifs_dbg(FYI, "Set reconnect bitmask for chan %u; now 0x%lx\n",
103 		 chan_index, ses->chans_need_reconnect);
104 }
105 
106 void
107 cifs_chan_clear_need_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 	clear_bit(chan_index, &ses->chans_need_reconnect);
116 	cifs_dbg(FYI, "Cleared reconnect bitmask for chan %u; now 0x%lx\n",
117 		 chan_index, ses->chans_need_reconnect);
118 }
119 
120 bool
121 cifs_chan_needs_reconnect(struct cifs_ses *ses,
122 			  struct TCP_Server_Info *server)
123 {
124 	unsigned int chan_index = cifs_ses_get_chan_index(ses, server);
125 
126 	if (chan_index == CIFS_INVAL_CHAN_INDEX)
127 		return true;	/* err on the safer side */
128 
129 	return CIFS_CHAN_NEEDS_RECONNECT(ses, chan_index);
130 }
131 
132 bool
133 cifs_chan_is_iface_active(struct cifs_ses *ses,
134 			  struct TCP_Server_Info *server)
135 {
136 	unsigned int chan_index = cifs_ses_get_chan_index(ses, server);
137 
138 	if (chan_index == CIFS_INVAL_CHAN_INDEX)
139 		return true;	/* err on the safer side */
140 
141 	return ses->chans[chan_index].iface &&
142 		ses->chans[chan_index].iface->is_active;
143 }
144 
145 /* returns number of channels added */
146 int cifs_try_adding_channels(struct cifs_ses *ses)
147 {
148 	struct TCP_Server_Info *server = ses->server;
149 	int old_chan_count, new_chan_count;
150 	int left;
151 	int rc = 0;
152 	int tries = 0;
153 	size_t iface_weight = 0, iface_min_speed = 0;
154 	struct cifs_server_iface *iface = NULL, *niface = NULL;
155 	struct cifs_server_iface *last_iface = NULL;
156 
157 	spin_lock(&ses->chan_lock);
158 
159 	new_chan_count = old_chan_count = ses->chan_count;
160 	left = ses->chan_max - ses->chan_count;
161 
162 	if (left <= 0) {
163 		spin_unlock(&ses->chan_lock);
164 		cifs_dbg(FYI,
165 			 "ses already at max_channels (%zu), nothing to open\n",
166 			 ses->chan_max);
167 		return 0;
168 	}
169 
170 	if (server->dialect < SMB30_PROT_ID) {
171 		spin_unlock(&ses->chan_lock);
172 		cifs_dbg(VFS, "multichannel is not supported on this protocol version, use 3.0 or above\n");
173 		return 0;
174 	}
175 
176 	if (!(server->capabilities & SMB2_GLOBAL_CAP_MULTI_CHANNEL)) {
177 		spin_unlock(&ses->chan_lock);
178 		cifs_server_dbg(VFS, "no multichannel support\n");
179 		return 0;
180 	}
181 	spin_unlock(&ses->chan_lock);
182 
183 	while (left > 0) {
184 
185 		tries++;
186 		if (tries > 3*ses->chan_max) {
187 			cifs_dbg(VFS, "too many channel open attempts (%d channels left to open)\n",
188 				 left);
189 			break;
190 		}
191 
192 		spin_lock(&ses->iface_lock);
193 		if (!ses->iface_count) {
194 			spin_unlock(&ses->iface_lock);
195 			cifs_dbg(ONCE, "server %s does not advertise interfaces\n",
196 				      ses->server->hostname);
197 			break;
198 		}
199 
200 		if (!iface)
201 			iface = list_first_entry(&ses->iface_list, struct cifs_server_iface,
202 						 iface_head);
203 		last_iface = list_last_entry(&ses->iface_list, struct cifs_server_iface,
204 					     iface_head);
205 		iface_min_speed = last_iface->speed;
206 
207 		list_for_each_entry_safe_from(iface, niface, &ses->iface_list,
208 				    iface_head) {
209 			/* do not mix rdma and non-rdma interfaces */
210 			if (iface->rdma_capable != ses->server->rdma)
211 				continue;
212 
213 			/* skip ifaces that are unusable */
214 			if (!iface->is_active ||
215 			    (is_ses_using_iface(ses, iface) &&
216 			     !iface->rss_capable))
217 				continue;
218 
219 			/* check if we already allocated enough channels */
220 			iface_weight = iface->speed / iface_min_speed;
221 
222 			if (iface->weight_fulfilled >= iface_weight)
223 				continue;
224 
225 			/* take ref before unlock */
226 			kref_get(&iface->refcount);
227 
228 			spin_unlock(&ses->iface_lock);
229 			rc = cifs_ses_add_channel(ses, iface);
230 			spin_lock(&ses->iface_lock);
231 
232 			if (rc) {
233 				cifs_dbg(VFS, "failed to open extra channel on iface:%pIS rc=%d\n",
234 					 &iface->sockaddr,
235 					 rc);
236 				kref_put(&iface->refcount, release_iface);
237 				/* failure to add chan should increase weight */
238 				iface->weight_fulfilled++;
239 				continue;
240 			}
241 
242 			iface->num_channels++;
243 			iface->weight_fulfilled++;
244 			cifs_info("successfully opened new channel on iface:%pIS\n",
245 				 &iface->sockaddr);
246 			break;
247 		}
248 
249 		/* reached end of list. reset weight_fulfilled and start over */
250 		if (list_entry_is_head(iface, &ses->iface_list, iface_head)) {
251 			list_for_each_entry(iface, &ses->iface_list, iface_head)
252 				iface->weight_fulfilled = 0;
253 			spin_unlock(&ses->iface_lock);
254 			iface = NULL;
255 			continue;
256 		}
257 		spin_unlock(&ses->iface_lock);
258 
259 		left--;
260 		new_chan_count++;
261 	}
262 
263 	return new_chan_count - old_chan_count;
264 }
265 
266 /*
267  * cifs_decrease_secondary_channels - Reduce the number of active secondary channels
268  * @ses: pointer to the CIFS session structure
269  * @disable_mchan: if true, reduce to a single channel; if false, reduce to chan_max
270  *
271  * This function disables and cleans up extra secondary channels for a CIFS session.
272  * If called during reconfiguration, it reduces the channel count to the new maximum (chan_max).
273  * Otherwise, it disables all but the primary channel.
274  */
275 void
276 cifs_decrease_secondary_channels(struct cifs_ses *ses, bool disable_mchan)
277 {
278 	int i, chan_count;
279 	struct TCP_Server_Info *server;
280 	struct cifs_server_iface *iface;
281 
282 	spin_lock(&ses->chan_lock);
283 	chan_count = ses->chan_count;
284 	if (chan_count == 1)
285 		goto done;
286 
287 	/* Update the chan_count to the new maximum */
288 	if (disable_mchan) {
289 		cifs_dbg(FYI, "server does not support multichannel anymore.\n");
290 		ses->chan_count = 1;
291 	} else {
292 		ses->chan_count = ses->chan_max;
293 	}
294 
295 	/* Disable all secondary channels beyond the new chan_count */
296 	for (i = ses->chan_count ; i < chan_count; i++) {
297 		iface = ses->chans[i].iface;
298 		server = ses->chans[i].server;
299 
300 		/*
301 		 * remove these references first, since we need to unlock
302 		 * the chan_lock here, since iface_lock is a higher lock
303 		 */
304 		ses->chans[i].iface = NULL;
305 		ses->chans[i].server = NULL;
306 		spin_unlock(&ses->chan_lock);
307 
308 		if (iface) {
309 			spin_lock(&ses->iface_lock);
310 			iface->num_channels--;
311 			if (iface->weight_fulfilled)
312 				iface->weight_fulfilled--;
313 			kref_put(&iface->refcount, release_iface);
314 			spin_unlock(&ses->iface_lock);
315 		}
316 
317 		if (server) {
318 			if (!server->terminate) {
319 				server->terminate = true;
320 				cifs_signal_cifsd_for_reconnect(server, false);
321 			}
322 			cifs_put_tcp_session(server, false);
323 		}
324 
325 		spin_lock(&ses->chan_lock);
326 	}
327 
328 	/* For extra secondary channels, reset the need reconnect bit */
329 	if (ses->chan_count == 1) {
330 		cifs_dbg(VFS, "Disable all secondary channels\n");
331 		ses->chans_need_reconnect &= 1;
332 	} else {
333 		cifs_dbg(VFS, "Disable extra secondary channels\n");
334 		ses->chans_need_reconnect &= ((1UL << ses->chan_max) - 1);
335 	}
336 
337 done:
338 	spin_unlock(&ses->chan_lock);
339 }
340 
341 /* update the iface for the channel if necessary. */
342 void
343 cifs_chan_update_iface(struct cifs_ses *ses, struct TCP_Server_Info *server)
344 {
345 	unsigned int chan_index;
346 	size_t iface_weight = 0, iface_min_speed = 0;
347 	struct cifs_server_iface *iface = NULL;
348 	struct cifs_server_iface *old_iface = NULL;
349 	struct cifs_server_iface *last_iface = NULL;
350 	struct sockaddr_storage ss;
351 	int retry = 0;
352 
353 	spin_lock(&ses->chan_lock);
354 	chan_index = cifs_ses_get_chan_index(ses, server);
355 	if (chan_index == CIFS_INVAL_CHAN_INDEX) {
356 		spin_unlock(&ses->chan_lock);
357 		return;
358 	}
359 
360 	if (ses->chans[chan_index].iface) {
361 		old_iface = ses->chans[chan_index].iface;
362 		if (old_iface->is_active) {
363 			spin_unlock(&ses->chan_lock);
364 			return;
365 		}
366 	}
367 	spin_unlock(&ses->chan_lock);
368 
369 	spin_lock(&server->srv_lock);
370 	ss = server->dstaddr;
371 	spin_unlock(&server->srv_lock);
372 
373 	spin_lock(&ses->iface_lock);
374 	if (!ses->iface_count) {
375 		spin_unlock(&ses->iface_lock);
376 		cifs_dbg(ONCE, "server %s does not advertise interfaces\n", ses->server->hostname);
377 		return;
378 	}
379 
380 try_again:
381 	last_iface = list_last_entry(&ses->iface_list, struct cifs_server_iface,
382 				     iface_head);
383 	iface_min_speed = last_iface->speed;
384 
385 	/* then look for a new one */
386 	list_for_each_entry(iface, &ses->iface_list, iface_head) {
387 		if (!chan_index) {
388 			/* if we're trying to get the updated iface for primary channel */
389 			if (!cifs_match_ipaddr((struct sockaddr *) &ss,
390 					       (struct sockaddr *) &iface->sockaddr))
391 				continue;
392 
393 			kref_get(&iface->refcount);
394 			break;
395 		}
396 
397 		/* do not mix rdma and non-rdma interfaces */
398 		if (iface->rdma_capable != server->rdma)
399 			continue;
400 
401 		if (!iface->is_active ||
402 		    (is_ses_using_iface(ses, iface) &&
403 		     !iface->rss_capable)) {
404 			continue;
405 		}
406 
407 		/* check if we already allocated enough channels */
408 		iface_weight = iface->speed / iface_min_speed;
409 
410 		if (iface->weight_fulfilled >= iface_weight)
411 			continue;
412 
413 		kref_get(&iface->refcount);
414 		break;
415 	}
416 
417 	if (list_entry_is_head(iface, &ses->iface_list, iface_head)) {
418 		list_for_each_entry(iface, &ses->iface_list, iface_head)
419 			iface->weight_fulfilled = 0;
420 
421 		/* see if it can be satisfied in second attempt */
422 		if (!retry++)
423 			goto try_again;
424 
425 		iface = NULL;
426 		cifs_dbg(FYI, "unable to find a suitable iface\n");
427 	}
428 
429 	if (!iface) {
430 		if (!chan_index)
431 			cifs_dbg(FYI, "unable to get the interface matching: %pIS\n",
432 				 &ss);
433 		else {
434 			cifs_dbg(FYI, "unable to find another interface to replace: %pIS\n",
435 				 &old_iface->sockaddr);
436 		}
437 
438 		spin_unlock(&ses->iface_lock);
439 		return;
440 	}
441 
442 	/* now drop the ref to the current iface */
443 	if (old_iface) {
444 		cifs_dbg(FYI, "replacing iface: %pIS with %pIS\n",
445 			 &old_iface->sockaddr,
446 			 &iface->sockaddr);
447 
448 		old_iface->num_channels--;
449 		if (old_iface->weight_fulfilled)
450 			old_iface->weight_fulfilled--;
451 		iface->num_channels++;
452 		iface->weight_fulfilled++;
453 
454 		kref_put(&old_iface->refcount, release_iface);
455 	} else if (!chan_index) {
456 		/* special case: update interface for primary channel */
457 		cifs_dbg(FYI, "referencing primary channel iface: %pIS\n",
458 			 &iface->sockaddr);
459 		iface->num_channels++;
460 		iface->weight_fulfilled++;
461 	}
462 	spin_unlock(&ses->iface_lock);
463 
464 	spin_lock(&ses->chan_lock);
465 	chan_index = cifs_ses_get_chan_index(ses, server);
466 	if (chan_index == CIFS_INVAL_CHAN_INDEX) {
467 		spin_unlock(&ses->chan_lock);
468 		return;
469 	}
470 
471 	ses->chans[chan_index].iface = iface;
472 	spin_unlock(&ses->chan_lock);
473 
474 	spin_lock(&server->srv_lock);
475 	memcpy(&server->dstaddr, &iface->sockaddr, sizeof(server->dstaddr));
476 	spin_unlock(&server->srv_lock);
477 }
478 
479 static int
480 cifs_ses_add_channel(struct cifs_ses *ses,
481 		     struct cifs_server_iface *iface)
482 {
483 	struct TCP_Server_Info *chan_server;
484 	struct cifs_chan *chan;
485 	struct smb3_fs_context *ctx;
486 	static const char unc_fmt[] = "\\%s\\foo";
487 	struct sockaddr_in *ipv4 = (struct sockaddr_in *)&iface->sockaddr;
488 	struct sockaddr_in6 *ipv6 = (struct sockaddr_in6 *)&iface->sockaddr;
489 	size_t len;
490 	int rc;
491 	unsigned int xid = get_xid();
492 
493 	if (iface->sockaddr.ss_family == AF_INET)
494 		cifs_dbg(FYI, "adding channel to ses %p (speed:%zu bps rdma:%s ip:%pI4)\n",
495 			 ses, iface->speed, str_yes_no(iface->rdma_capable),
496 			 &ipv4->sin_addr);
497 	else
498 		cifs_dbg(FYI, "adding channel to ses %p (speed:%zu bps rdma:%s ip:%pI6)\n",
499 			 ses, iface->speed, str_yes_no(iface->rdma_capable),
500 			 &ipv6->sin6_addr);
501 
502 	/*
503 	 * Setup a ctx with mostly the same info as the existing
504 	 * session and overwrite it with the requested iface data.
505 	 *
506 	 * We need to setup at least the fields used for negprot and
507 	 * sesssetup.
508 	 *
509 	 * We only need the ctx here, so we can reuse memory from
510 	 * the session and server without caring about memory
511 	 * management.
512 	 */
513 	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
514 	if (!ctx) {
515 		rc = -ENOMEM;
516 		goto out_free_xid;
517 	}
518 
519 	/* Always make new connection for now (TODO?) */
520 	ctx->nosharesock = true;
521 
522 	/* Auth */
523 	ctx->domainauto = ses->domainAuto;
524 	ctx->domainname = ses->domainName;
525 
526 	ctx->server_hostname = ses->server->hostname;
527 
528 	ctx->username = ses->user_name;
529 	ctx->password = ses->password;
530 	ctx->sectype = ses->sectype;
531 	ctx->sign = ses->sign;
532 	ctx->unicode = ses->unicode;
533 
534 	/* UNC and paths */
535 	/* XXX: Use ses->server->hostname? */
536 	len = sizeof(unc_fmt) + SERVER_NAME_LEN_WITH_NULL;
537 	ctx->UNC = kzalloc(len, GFP_KERNEL);
538 	if (!ctx->UNC) {
539 		rc = -ENOMEM;
540 		goto out_free_ctx;
541 	}
542 	scnprintf(ctx->UNC, len, unc_fmt, ses->ip_addr);
543 	ctx->prepath = "";
544 
545 	/* Reuse same version as master connection */
546 	ctx->vals = ses->server->vals;
547 	ctx->ops = ses->server->ops;
548 
549 	ctx->noblocksnd = ses->server->noblocksnd;
550 	ctx->noautotune = ses->server->noautotune;
551 	ctx->sockopt_tcp_nodelay = ses->server->tcp_nodelay;
552 	ctx->echo_interval = ses->server->echo_interval / HZ;
553 	ctx->max_credits = ses->server->max_credits;
554 	ctx->min_offload = ses->server->min_offload;
555 	ctx->compress = ses->server->compression.requested;
556 	ctx->dfs_conn = ses->server->dfs_conn;
557 	ctx->ignore_signature = ses->server->ignore_signature;
558 	ctx->leaf_fullpath = ses->server->leaf_fullpath;
559 	ctx->rootfs = ses->server->noblockcnt;
560 	ctx->retrans = ses->server->retrans;
561 
562 	/*
563 	 * This will be used for encoding/decoding user/domain/pw
564 	 * during sess setup auth.
565 	 */
566 	ctx->local_nls = ses->local_nls;
567 
568 	/* Use RDMA if possible */
569 	ctx->rdma = iface->rdma_capable;
570 	memcpy(&ctx->dstaddr, &iface->sockaddr, sizeof(ctx->dstaddr));
571 
572 	/* reuse master con client guid */
573 	memcpy(&ctx->client_guid, ses->server->client_guid,
574 	       sizeof(ctx->client_guid));
575 	ctx->use_client_guid = true;
576 
577 	chan_server = cifs_get_tcp_session(ctx, ses->server);
578 
579 	spin_lock(&ses->chan_lock);
580 	chan = &ses->chans[ses->chan_count];
581 	chan->server = chan_server;
582 	if (IS_ERR(chan->server)) {
583 		rc = PTR_ERR(chan->server);
584 		chan->server = NULL;
585 		spin_unlock(&ses->chan_lock);
586 		goto out;
587 	}
588 	chan->iface = iface;
589 	ses->chan_count++;
590 	atomic_set(&ses->chan_seq, 0);
591 
592 	/* Mark this channel as needing connect/setup */
593 	cifs_chan_set_need_reconnect(ses, chan->server);
594 
595 	spin_unlock(&ses->chan_lock);
596 
597 	mutex_lock(&ses->session_mutex);
598 	/*
599 	 * We need to allocate the server crypto now as we will need
600 	 * to sign packets before we generate the channel signing key
601 	 * (we sign with the session key)
602 	 */
603 	rc = smb3_crypto_shash_allocate(chan->server);
604 	if (rc) {
605 		cifs_dbg(VFS, "%s: crypto alloc failed\n", __func__);
606 		mutex_unlock(&ses->session_mutex);
607 		goto out;
608 	}
609 
610 	rc = cifs_negotiate_protocol(xid, ses, chan->server);
611 	if (!rc)
612 		rc = cifs_setup_session(xid, ses, chan->server, ses->local_nls);
613 
614 	mutex_unlock(&ses->session_mutex);
615 
616 out:
617 	if (rc && chan->server) {
618 		cifs_put_tcp_session(chan->server, 0);
619 
620 		spin_lock(&ses->chan_lock);
621 
622 		/* we rely on all bits beyond chan_count to be clear */
623 		cifs_chan_clear_need_reconnect(ses, chan->server);
624 		ses->chan_count--;
625 		/*
626 		 * chan_count should never reach 0 as at least the primary
627 		 * channel is always allocated
628 		 */
629 		WARN_ON(ses->chan_count < 1);
630 		spin_unlock(&ses->chan_lock);
631 	}
632 
633 	kfree(ctx->UNC);
634 out_free_ctx:
635 	kfree(ctx);
636 out_free_xid:
637 	free_xid(xid);
638 	return rc;
639 }
640 
641 
642 int decode_ntlmssp_challenge(char *bcc_ptr, int blob_len,
643 				    struct cifs_ses *ses)
644 {
645 	unsigned int tioffset; /* challenge message target info area */
646 	unsigned int tilen; /* challenge message target info area length  */
647 	CHALLENGE_MESSAGE *pblob = (CHALLENGE_MESSAGE *)bcc_ptr;
648 	__u32 server_flags;
649 
650 	if (blob_len < sizeof(CHALLENGE_MESSAGE)) {
651 		cifs_dbg(VFS, "challenge blob len %d too small\n", blob_len);
652 		return -EINVAL;
653 	}
654 
655 	if (memcmp(pblob->Signature, "NTLMSSP", 8)) {
656 		cifs_dbg(VFS, "blob signature incorrect %s\n",
657 			 pblob->Signature);
658 		return -EINVAL;
659 	}
660 	if (pblob->MessageType != NtLmChallenge) {
661 		cifs_dbg(VFS, "Incorrect message type %d\n",
662 			 pblob->MessageType);
663 		return -EINVAL;
664 	}
665 
666 	server_flags = le32_to_cpu(pblob->NegotiateFlags);
667 	cifs_dbg(FYI, "%s: negotiate=0x%08x challenge=0x%08x\n", __func__,
668 		 ses->ntlmssp->client_flags, server_flags);
669 
670 	if ((ses->ntlmssp->client_flags & (NTLMSSP_NEGOTIATE_SEAL | NTLMSSP_NEGOTIATE_SIGN)) &&
671 	    (!(server_flags & NTLMSSP_NEGOTIATE_56) && !(server_flags & NTLMSSP_NEGOTIATE_128))) {
672 		cifs_dbg(VFS, "%s: requested signing/encryption but server did not return either 56-bit or 128-bit session key size\n",
673 			 __func__);
674 		return -EINVAL;
675 	}
676 	if (!(server_flags & NTLMSSP_NEGOTIATE_NTLM) && !(server_flags & NTLMSSP_NEGOTIATE_EXTENDED_SEC)) {
677 		cifs_dbg(VFS, "%s: server does not seem to support either NTLMv1 or NTLMv2\n", __func__);
678 		return -EINVAL;
679 	}
680 	if (ses->server->sign && !(server_flags & NTLMSSP_NEGOTIATE_SIGN)) {
681 		cifs_dbg(VFS, "%s: forced packet signing but server does not seem to support it\n",
682 			 __func__);
683 		return -EOPNOTSUPP;
684 	}
685 	if ((ses->ntlmssp->client_flags & NTLMSSP_NEGOTIATE_KEY_XCH) &&
686 	    !(server_flags & NTLMSSP_NEGOTIATE_KEY_XCH))
687 		pr_warn_once("%s: authentication has been weakened as server does not support key exchange\n",
688 			     __func__);
689 
690 	ses->ntlmssp->server_flags = server_flags;
691 
692 	memcpy(ses->ntlmssp->cryptkey, pblob->Challenge, CIFS_CRYPTO_KEY_SIZE);
693 	/*
694 	 * In particular we can examine sign flags
695 	 *
696 	 * BB spec says that if AvId field of MsvAvTimestamp is populated then
697 	 * we must set the MIC field of the AUTHENTICATE_MESSAGE
698 	 */
699 
700 	tioffset = le32_to_cpu(pblob->TargetInfoArray.BufferOffset);
701 	tilen = le16_to_cpu(pblob->TargetInfoArray.Length);
702 	if (tioffset > blob_len || tioffset + tilen > blob_len) {
703 		cifs_dbg(VFS, "tioffset + tilen too high %u + %u\n",
704 			 tioffset, tilen);
705 		return -EINVAL;
706 	}
707 	if (tilen) {
708 		kfree_sensitive(ses->auth_key.response);
709 		ses->auth_key.response = kmemdup(bcc_ptr + tioffset, tilen,
710 						 GFP_KERNEL);
711 		if (!ses->auth_key.response) {
712 			cifs_dbg(VFS, "Challenge target info alloc failure\n");
713 			return -ENOMEM;
714 		}
715 		ses->auth_key.len = tilen;
716 	}
717 
718 	return 0;
719 }
720 
721 static int size_of_ntlmssp_blob(struct cifs_ses *ses, int base_size)
722 {
723 	int sz = base_size + ses->auth_key.len
724 		- CIFS_SESS_KEY_SIZE + CIFS_CPHTXT_SIZE + 2;
725 
726 	if (ses->domainName)
727 		sz += sizeof(__le16) * strnlen(ses->domainName, CIFS_MAX_DOMAINNAME_LEN);
728 	else
729 		sz += sizeof(__le16);
730 
731 	if (ses->user_name)
732 		sz += sizeof(__le16) * strnlen(ses->user_name, CIFS_MAX_USERNAME_LEN);
733 	else
734 		sz += sizeof(__le16);
735 
736 	if (ses->workstation_name[0])
737 		sz += sizeof(__le16) * strnlen(ses->workstation_name,
738 					       ntlmssp_workstation_name_size(ses));
739 	else
740 		sz += sizeof(__le16);
741 
742 	return sz;
743 }
744 
745 static inline void cifs_security_buffer_from_str(SECURITY_BUFFER *pbuf,
746 						 char *str_value,
747 						 int str_length,
748 						 unsigned char *pstart,
749 						 unsigned char **pcur,
750 						 const struct nls_table *nls_cp)
751 {
752 	unsigned char *tmp = pstart;
753 	int len;
754 
755 	if (!pbuf)
756 		return;
757 
758 	if (!pcur)
759 		pcur = &tmp;
760 
761 	if (!str_value) {
762 		pbuf->BufferOffset = cpu_to_le32(*pcur - pstart);
763 		pbuf->Length = 0;
764 		pbuf->MaximumLength = 0;
765 		*pcur += sizeof(__le16);
766 	} else {
767 		len = cifs_strtoUTF16((__le16 *)*pcur,
768 				      str_value,
769 				      str_length,
770 				      nls_cp);
771 		len *= sizeof(__le16);
772 		pbuf->BufferOffset = cpu_to_le32(*pcur - pstart);
773 		pbuf->Length = cpu_to_le16(len);
774 		pbuf->MaximumLength = cpu_to_le16(len);
775 		*pcur += len;
776 	}
777 }
778 
779 /* BB Move to ntlmssp.c eventually */
780 
781 int build_ntlmssp_negotiate_blob(unsigned char **pbuffer,
782 				 u16 *buflen,
783 				 struct cifs_ses *ses,
784 				 struct TCP_Server_Info *server,
785 				 const struct nls_table *nls_cp)
786 {
787 	int rc = 0;
788 	NEGOTIATE_MESSAGE *sec_blob;
789 	__u32 flags;
790 	unsigned char *tmp;
791 	int len;
792 
793 	len = size_of_ntlmssp_blob(ses, sizeof(NEGOTIATE_MESSAGE));
794 	*pbuffer = kmalloc(len, GFP_KERNEL);
795 	if (!*pbuffer) {
796 		rc = -ENOMEM;
797 		cifs_dbg(VFS, "Error %d during NTLMSSP allocation\n", rc);
798 		*buflen = 0;
799 		goto setup_ntlm_neg_ret;
800 	}
801 	sec_blob = (NEGOTIATE_MESSAGE *)*pbuffer;
802 
803 	memset(*pbuffer, 0, sizeof(NEGOTIATE_MESSAGE));
804 	memcpy(sec_blob->Signature, NTLMSSP_SIGNATURE, 8);
805 	sec_blob->MessageType = NtLmNegotiate;
806 
807 	/* BB is NTLMV2 session security format easier to use here? */
808 	flags = NTLMSSP_NEGOTIATE_56 |	NTLMSSP_REQUEST_TARGET |
809 		NTLMSSP_NEGOTIATE_128 | NTLMSSP_NEGOTIATE_UNICODE |
810 		NTLMSSP_NEGOTIATE_NTLM | NTLMSSP_NEGOTIATE_EXTENDED_SEC |
811 		NTLMSSP_NEGOTIATE_ALWAYS_SIGN | NTLMSSP_NEGOTIATE_SEAL |
812 		NTLMSSP_NEGOTIATE_SIGN;
813 	if (!server->session_estab || ses->ntlmssp->sesskey_per_smbsess)
814 		flags |= NTLMSSP_NEGOTIATE_KEY_XCH;
815 
816 	tmp = *pbuffer + sizeof(NEGOTIATE_MESSAGE);
817 	ses->ntlmssp->client_flags = flags;
818 	sec_blob->NegotiateFlags = cpu_to_le32(flags);
819 
820 	/* these fields should be null in negotiate phase MS-NLMP 3.1.5.1.1 */
821 	cifs_security_buffer_from_str(&sec_blob->DomainName,
822 				      NULL,
823 				      CIFS_MAX_DOMAINNAME_LEN,
824 				      *pbuffer, &tmp,
825 				      nls_cp);
826 
827 	cifs_security_buffer_from_str(&sec_blob->WorkstationName,
828 				      NULL,
829 				      CIFS_MAX_WORKSTATION_LEN,
830 				      *pbuffer, &tmp,
831 				      nls_cp);
832 
833 	*buflen = tmp - *pbuffer;
834 setup_ntlm_neg_ret:
835 	return rc;
836 }
837 
838 /*
839  * Build ntlmssp blob with additional fields, such as version,
840  * supported by modern servers. For safety limit to SMB3 or later
841  * See notes in MS-NLMP Section 2.2.2.1 e.g.
842  */
843 int build_ntlmssp_smb3_negotiate_blob(unsigned char **pbuffer,
844 				 u16 *buflen,
845 				 struct cifs_ses *ses,
846 				 struct TCP_Server_Info *server,
847 				 const struct nls_table *nls_cp)
848 {
849 	int rc = 0;
850 	struct negotiate_message *sec_blob;
851 	__u32 flags;
852 	unsigned char *tmp;
853 	int len;
854 
855 	len = size_of_ntlmssp_blob(ses, sizeof(struct negotiate_message));
856 	*pbuffer = kmalloc(len, GFP_KERNEL);
857 	if (!*pbuffer) {
858 		rc = -ENOMEM;
859 		cifs_dbg(VFS, "Error %d during NTLMSSP allocation\n", rc);
860 		*buflen = 0;
861 		goto setup_ntlm_smb3_neg_ret;
862 	}
863 	sec_blob = (struct negotiate_message *)*pbuffer;
864 
865 	memset(*pbuffer, 0, sizeof(struct negotiate_message));
866 	memcpy(sec_blob->Signature, NTLMSSP_SIGNATURE, 8);
867 	sec_blob->MessageType = NtLmNegotiate;
868 
869 	/* BB is NTLMV2 session security format easier to use here? */
870 	flags = NTLMSSP_NEGOTIATE_56 |	NTLMSSP_REQUEST_TARGET |
871 		NTLMSSP_NEGOTIATE_128 | NTLMSSP_NEGOTIATE_UNICODE |
872 		NTLMSSP_NEGOTIATE_NTLM | NTLMSSP_NEGOTIATE_EXTENDED_SEC |
873 		NTLMSSP_NEGOTIATE_ALWAYS_SIGN | NTLMSSP_NEGOTIATE_SEAL |
874 		NTLMSSP_NEGOTIATE_SIGN | NTLMSSP_NEGOTIATE_VERSION;
875 	if (!server->session_estab || ses->ntlmssp->sesskey_per_smbsess)
876 		flags |= NTLMSSP_NEGOTIATE_KEY_XCH;
877 
878 	sec_blob->Version.ProductMajorVersion = LINUX_VERSION_MAJOR;
879 	sec_blob->Version.ProductMinorVersion = LINUX_VERSION_PATCHLEVEL;
880 	sec_blob->Version.ProductBuild = cpu_to_le16(SMB3_PRODUCT_BUILD);
881 	sec_blob->Version.NTLMRevisionCurrent = NTLMSSP_REVISION_W2K3;
882 
883 	tmp = *pbuffer + sizeof(struct negotiate_message);
884 	ses->ntlmssp->client_flags = flags;
885 	sec_blob->NegotiateFlags = cpu_to_le32(flags);
886 
887 	/* these fields should be null in negotiate phase MS-NLMP 3.1.5.1.1 */
888 	cifs_security_buffer_from_str(&sec_blob->DomainName,
889 				      NULL,
890 				      CIFS_MAX_DOMAINNAME_LEN,
891 				      *pbuffer, &tmp,
892 				      nls_cp);
893 
894 	cifs_security_buffer_from_str(&sec_blob->WorkstationName,
895 				      NULL,
896 				      CIFS_MAX_WORKSTATION_LEN,
897 				      *pbuffer, &tmp,
898 				      nls_cp);
899 
900 	*buflen = tmp - *pbuffer;
901 setup_ntlm_smb3_neg_ret:
902 	return rc;
903 }
904 
905 
906 /* See MS-NLMP 2.2.1.3 */
907 int build_ntlmssp_auth_blob(unsigned char **pbuffer,
908 					u16 *buflen,
909 				   struct cifs_ses *ses,
910 				   struct TCP_Server_Info *server,
911 				   const struct nls_table *nls_cp)
912 {
913 	int rc;
914 	AUTHENTICATE_MESSAGE *sec_blob;
915 	__u32 flags;
916 	unsigned char *tmp;
917 	int len;
918 
919 	rc = setup_ntlmv2_rsp(ses, nls_cp);
920 	if (rc) {
921 		cifs_dbg(VFS, "Error %d during NTLMSSP authentication\n", rc);
922 		*buflen = 0;
923 		goto setup_ntlmv2_ret;
924 	}
925 
926 	len = size_of_ntlmssp_blob(ses, sizeof(AUTHENTICATE_MESSAGE));
927 	*pbuffer = kmalloc(len, GFP_KERNEL);
928 	if (!*pbuffer) {
929 		rc = -ENOMEM;
930 		cifs_dbg(VFS, "Error %d during NTLMSSP allocation\n", rc);
931 		*buflen = 0;
932 		goto setup_ntlmv2_ret;
933 	}
934 	sec_blob = (AUTHENTICATE_MESSAGE *)*pbuffer;
935 
936 	memcpy(sec_blob->Signature, NTLMSSP_SIGNATURE, 8);
937 	sec_blob->MessageType = NtLmAuthenticate;
938 
939 	/* send version information in ntlmssp authenticate also */
940 	flags = ses->ntlmssp->server_flags | NTLMSSP_REQUEST_TARGET |
941 		NTLMSSP_NEGOTIATE_TARGET_INFO | NTLMSSP_NEGOTIATE_VERSION |
942 		NTLMSSP_NEGOTIATE_WORKSTATION_SUPPLIED;
943 
944 	sec_blob->Version.ProductMajorVersion = LINUX_VERSION_MAJOR;
945 	sec_blob->Version.ProductMinorVersion = LINUX_VERSION_PATCHLEVEL;
946 	sec_blob->Version.ProductBuild = cpu_to_le16(SMB3_PRODUCT_BUILD);
947 	sec_blob->Version.NTLMRevisionCurrent = NTLMSSP_REVISION_W2K3;
948 
949 	tmp = *pbuffer + sizeof(AUTHENTICATE_MESSAGE);
950 	sec_blob->NegotiateFlags = cpu_to_le32(flags);
951 
952 	sec_blob->LmChallengeResponse.BufferOffset =
953 				cpu_to_le32(sizeof(AUTHENTICATE_MESSAGE));
954 	sec_blob->LmChallengeResponse.Length = 0;
955 	sec_blob->LmChallengeResponse.MaximumLength = 0;
956 
957 	sec_blob->NtChallengeResponse.BufferOffset =
958 				cpu_to_le32(tmp - *pbuffer);
959 	if (ses->user_name != NULL) {
960 		memcpy(tmp, ses->auth_key.response + CIFS_SESS_KEY_SIZE,
961 				ses->auth_key.len - CIFS_SESS_KEY_SIZE);
962 		tmp += ses->auth_key.len - CIFS_SESS_KEY_SIZE;
963 
964 		sec_blob->NtChallengeResponse.Length =
965 				cpu_to_le16(ses->auth_key.len - CIFS_SESS_KEY_SIZE);
966 		sec_blob->NtChallengeResponse.MaximumLength =
967 				cpu_to_le16(ses->auth_key.len - CIFS_SESS_KEY_SIZE);
968 	} else {
969 		/*
970 		 * don't send an NT Response for anonymous access
971 		 */
972 		sec_blob->NtChallengeResponse.Length = 0;
973 		sec_blob->NtChallengeResponse.MaximumLength = 0;
974 	}
975 
976 	cifs_security_buffer_from_str(&sec_blob->DomainName,
977 				      ses->domainName,
978 				      CIFS_MAX_DOMAINNAME_LEN,
979 				      *pbuffer, &tmp,
980 				      nls_cp);
981 
982 	cifs_security_buffer_from_str(&sec_blob->UserName,
983 				      ses->user_name,
984 				      CIFS_MAX_USERNAME_LEN,
985 				      *pbuffer, &tmp,
986 				      nls_cp);
987 
988 	cifs_security_buffer_from_str(&sec_blob->WorkstationName,
989 				      ses->workstation_name,
990 				      ntlmssp_workstation_name_size(ses),
991 				      *pbuffer, &tmp,
992 				      nls_cp);
993 
994 	if ((ses->ntlmssp->server_flags & NTLMSSP_NEGOTIATE_KEY_XCH) &&
995 	    (!ses->server->session_estab || ses->ntlmssp->sesskey_per_smbsess) &&
996 	    !calc_seckey(ses)) {
997 		memcpy(tmp, ses->ntlmssp->ciphertext, CIFS_CPHTXT_SIZE);
998 		sec_blob->SessionKey.BufferOffset = cpu_to_le32(tmp - *pbuffer);
999 		sec_blob->SessionKey.Length = cpu_to_le16(CIFS_CPHTXT_SIZE);
1000 		sec_blob->SessionKey.MaximumLength =
1001 				cpu_to_le16(CIFS_CPHTXT_SIZE);
1002 		tmp += CIFS_CPHTXT_SIZE;
1003 	} else {
1004 		sec_blob->SessionKey.BufferOffset = cpu_to_le32(tmp - *pbuffer);
1005 		sec_blob->SessionKey.Length = 0;
1006 		sec_blob->SessionKey.MaximumLength = 0;
1007 	}
1008 
1009 	*buflen = tmp - *pbuffer;
1010 setup_ntlmv2_ret:
1011 	return rc;
1012 }
1013 
1014 enum securityEnum
1015 cifs_select_sectype(struct TCP_Server_Info *server, enum securityEnum requested)
1016 {
1017 	switch (server->negflavor) {
1018 	case CIFS_NEGFLAVOR_EXTENDED:
1019 		switch (requested) {
1020 		case Kerberos:
1021 		case RawNTLMSSP:
1022 		case IAKerb:
1023 			return requested;
1024 		case Unspecified:
1025 			if (server->sec_ntlmssp &&
1026 			    (global_secflags & CIFSSEC_MAY_NTLMSSP))
1027 				return RawNTLMSSP;
1028 			if ((server->sec_kerberos || server->sec_mskerberos || server->sec_iakerb) &&
1029 			    (global_secflags & CIFSSEC_MAY_KRB5))
1030 				return Kerberos;
1031 			fallthrough;
1032 		default:
1033 			return Unspecified;
1034 		}
1035 	case CIFS_NEGFLAVOR_UNENCAP:
1036 		switch (requested) {
1037 		case NTLMv2:
1038 			return requested;
1039 		case Unspecified:
1040 			if (global_secflags & CIFSSEC_MAY_NTLMV2)
1041 				return NTLMv2;
1042 			break;
1043 		default:
1044 			break;
1045 		}
1046 		fallthrough;
1047 	default:
1048 		return Unspecified;
1049 	}
1050 }
1051