1 /*
2  * This file and its contents are supplied under the terms of the
3  * Common Development and Distribution License ("CDDL"), version 1.0.
4  * You may only use this file in accordance with the terms of version
5  * 1.0 of the CDDL.
6  *
7  * A full copy of the text of the CDDL should have accompanied this
8  * source.  A copy of the CDDL is also available via the Internet at
9  * http://www.illumos.org/license/CDDL.
10  */
11 
12 /*
13  * Copyright 2019 Nexenta Systems, Inc.  All rights reserved.
14  * Copyright 2019 RackTop Systems.
15  */
16 
17 
18 #include <smbsrv/smb2_kproto.h>
19 #include <smbsrv/smb_kstat.h>
20 #include <smbsrv/smb2.h>
21 
22 #define	SMB2_ASYNCID(sr) (sr->smb2_messageid ^ (1ULL << 62))
23 
24 smb_sdrc_t smb2_invalid_cmd(smb_request_t *);
25 static void smb2_tq_work(void *);
26 static void smb2sr_run_postwork(smb_request_t *);
27 static int smb3_decrypt_msg(smb_request_t *);
28 
29 static const smb_disp_entry_t
30 smb2_disp_table[SMB2__NCMDS] = {
31 
32 	/* text-name, pre, func, post, cmd-code, dialect, flags */
33 
34 	{  "smb2_negotiate", NULL,
35 	    smb2_negotiate, NULL, 0, 0,
36 	    SDDF_SUPPRESS_TID | SDDF_SUPPRESS_UID },
37 
38 	{  "smb2_session_setup", NULL,
39 	    smb2_session_setup, NULL, 0, 0,
40 	    SDDF_SUPPRESS_TID | SDDF_SUPPRESS_UID },
41 
42 	{  "smb2_logoff", NULL,
43 	    smb2_logoff, NULL, 0, 0,
44 	    SDDF_SUPPRESS_TID },
45 
46 	{  "smb2_tree_connect", NULL,
47 	    smb2_tree_connect, NULL, 0, 0,
48 	    SDDF_SUPPRESS_TID },
49 
50 	{  "smb2_tree_disconn", NULL,
51 	    smb2_tree_disconn, NULL, 0, 0 },
52 
53 	{  "smb2_create", NULL,
54 	    smb2_create, NULL, 0, 0 },
55 
56 	{  "smb2_close", NULL,
57 	    smb2_close, NULL, 0, 0 },
58 
59 	{  "smb2_flush", NULL,
60 	    smb2_flush, NULL, 0, 0 },
61 
62 	{  "smb2_read", NULL,
63 	    smb2_read, NULL, 0, 0 },
64 
65 	{  "smb2_write", NULL,
66 	    smb2_write, NULL, 0, 0 },
67 
68 	{  "smb2_lock", NULL,
69 	    smb2_lock, NULL, 0, 0 },
70 
71 	{  "smb2_ioctl", NULL,
72 	    smb2_ioctl, NULL, 0, 0 },
73 
74 	{  "smb2_cancel", NULL,
75 	    smb2_cancel, NULL, 0, 0,
76 	    SDDF_SUPPRESS_UID | SDDF_SUPPRESS_TID },
77 
78 	{  "smb2_echo", NULL,
79 	    smb2_echo, NULL, 0, 0,
80 	    SDDF_SUPPRESS_UID | SDDF_SUPPRESS_TID },
81 
82 	{  "smb2_query_dir", NULL,
83 	    smb2_query_dir, NULL, 0, 0 },
84 
85 	{  "smb2_change_notify", NULL,
86 	    smb2_change_notify, NULL, 0, 0 },
87 
88 	{  "smb2_query_info", NULL,
89 	    smb2_query_info, NULL, 0, 0 },
90 
91 	{  "smb2_set_info", NULL,
92 	    smb2_set_info, NULL, 0, 0 },
93 
94 	{  "smb2_oplock_break_ack", NULL,
95 	    smb2_oplock_break_ack, NULL, 0, 0 },
96 
97 	{  "smb2_invalid_cmd", NULL,
98 	    smb2_invalid_cmd, NULL, 0, 0,
99 	    SDDF_SUPPRESS_UID | SDDF_SUPPRESS_TID },
100 };
101 
102 smb_sdrc_t
103 smb2_invalid_cmd(smb_request_t *sr)
104 {
105 #ifdef	DEBUG
106 	cmn_err(CE_NOTE, "clnt %s bad SMB2 cmd code",
107 	    sr->session->ip_addr_str);
108 #endif
109 	sr->smb2_status = NT_STATUS_INVALID_PARAMETER;
110 	return (SDRC_DROP_VC);
111 }
112 
113 /*
114  * This is the SMB2 handler for new smb requests, called from
115  * smb_session_reader after SMB negotiate is done.  For most SMB2
116  * requests, we just enqueue them for the smb_session_worker to
117  * execute via the task queue, so they can block for resources
118  * without stopping the reader thread.  A few protocol messages
119  * are special cases and are handled directly here in the reader
120  * thread so they don't wait for taskq scheduling.
121  *
122  * This function must either enqueue the new request for
123  * execution via the task queue, or execute it directly
124  * and then free it.  If this returns non-zero, the caller
125  * will drop the session.
126  */
127 int
128 smb2sr_newrq(smb_request_t *sr)
129 {
130 	struct mbuf_chain *mbc = &sr->command;
131 	uint32_t magic;
132 	int rc, skip;
133 
134 	if (smb_mbc_peek(mbc, 0, "l", &magic) != 0)
135 		goto drop;
136 
137 	/* 0xFD S M B */
138 	if (magic == SMB3_ENCRYPTED_MAGIC) {
139 		if (smb3_decrypt_msg(sr) != 0)
140 			goto drop;
141 		/*
142 		 * Should now be looking at an un-encrypted
143 		 * SMB2 message header.
144 		 */
145 		if (smb_mbc_peek(mbc, 0, "l", &magic) != 0)
146 			goto drop;
147 	}
148 
149 	if (magic != SMB2_PROTOCOL_MAGIC)
150 		goto drop;
151 
152 	/*
153 	 * Walk the SMB2 commands in this compound message and
154 	 * keep track of the range of message IDs it uses.
155 	 */
156 	for (;;) {
157 		if (smb2_decode_header(sr) != 0)
158 			goto drop;
159 
160 		/*
161 		 * Cancel requests are special:  They refer to
162 		 * an earlier message ID (or an async. ID),
163 		 * never a new ID, and are never compounded.
164 		 * This is intentionally not "goto drop"
165 		 * because rc may be zero (success).
166 		 */
167 		if (sr->smb2_cmd_code == SMB2_CANCEL) {
168 			rc = smb2_newrq_cancel(sr);
169 			smb_request_free(sr);
170 			return (rc);
171 		}
172 
173 		/*
174 		 * Keep track of the total credits in this compound
175 		 * and the first (real) message ID (not: 0, -1)
176 		 * While we're looking, verify that all (real) IDs
177 		 * are (first <= ID < (first + msg_credits))
178 		 */
179 		if (sr->smb2_credit_charge == 0)
180 			sr->smb2_credit_charge = 1;
181 		sr->smb2_total_credits += sr->smb2_credit_charge;
182 
183 		if (sr->smb2_messageid != 0 &&
184 		    sr->smb2_messageid != UINT64_MAX) {
185 
186 			if (sr->smb2_first_msgid == 0)
187 				sr->smb2_first_msgid = sr->smb2_messageid;
188 
189 			if (sr->smb2_messageid < sr->smb2_first_msgid ||
190 			    sr->smb2_messageid >= (sr->smb2_first_msgid +
191 			    sr->smb2_total_credits)) {
192 				long long id = (long long) sr->smb2_messageid;
193 				cmn_err(CE_WARN, "clnt %s msg ID 0x%llx "
194 				    "out of sequence in compound",
195 				    sr->session->ip_addr_str, id);
196 			}
197 		}
198 
199 		/* Normal loop exit on next == zero */
200 		if (sr->smb2_next_command == 0)
201 			break;
202 
203 		/* Abundance of caution... */
204 		if (sr->smb2_next_command < SMB2_HDR_SIZE)
205 			goto drop;
206 
207 		/* Advance to the next header. */
208 		skip = sr->smb2_next_command - SMB2_HDR_SIZE;
209 		if (MBC_ROOM_FOR(mbc, skip) == 0)
210 			goto drop;
211 		mbc->chain_offset += skip;
212 	}
213 	/* Rewind back to the top. */
214 	mbc->chain_offset = 0;
215 
216 	/*
217 	 * Submit the request to the task queue, which calls
218 	 * smb2_tq_work when the workload permits.
219 	 */
220 	sr->sr_time_submitted = gethrtime();
221 	sr->sr_state = SMB_REQ_STATE_SUBMITTED;
222 	smb_srqueue_waitq_enter(sr->session->s_srqueue);
223 	(void) taskq_dispatch(sr->sr_server->sv_worker_pool,
224 	    smb2_tq_work, sr, TQ_SLEEP);
225 	return (0);
226 
227 drop:
228 	smb_request_free(sr);
229 	return (-1);
230 }
231 
232 static void
233 smb2_tq_work(void *arg)
234 {
235 	smb_request_t	*sr;
236 	smb_srqueue_t	*srq;
237 
238 	sr = (smb_request_t *)arg;
239 	SMB_REQ_VALID(sr);
240 
241 	srq = sr->session->s_srqueue;
242 	smb_srqueue_waitq_to_runq(srq);
243 	sr->sr_worker = curthread;
244 	sr->sr_time_active = gethrtime();
245 
246 	/*
247 	 * Always dispatch to the work function, because cancelled
248 	 * requests need an error reply (NT_STATUS_CANCELLED).
249 	 */
250 	mutex_enter(&sr->sr_mutex);
251 	if (sr->sr_state == SMB_REQ_STATE_SUBMITTED)
252 		sr->sr_state = SMB_REQ_STATE_ACTIVE;
253 	mutex_exit(&sr->sr_mutex);
254 
255 	smb2sr_work(sr);
256 
257 	smb_srqueue_runq_exit(srq);
258 }
259 
260 static int
261 smb3_decrypt_msg(smb_request_t *sr)
262 {
263 	int save_offset;
264 
265 	if (sr->session->dialect < SMB_VERS_3_0) {
266 		cmn_err(CE_WARN, "encrypted message in SMB 2.x");
267 		return (-1);
268 	}
269 
270 	sr->encrypted = B_TRUE;
271 	save_offset = sr->command.chain_offset;
272 	if (smb3_decode_tform_header(sr) != 0) {
273 		cmn_err(CE_WARN, "bad transform header");
274 		return (-1);
275 	}
276 	sr->command.chain_offset = save_offset;
277 
278 	sr->tform_ssn = smb_session_lookup_ssnid(sr->session,
279 	    sr->smb3_tform_ssnid);
280 	if (sr->tform_ssn == NULL) {
281 		cmn_err(CE_WARN, "transform header: session not found");
282 		return (-1);
283 	}
284 
285 	if (smb3_decrypt_sr(sr) != 0) {
286 		cmn_err(CE_WARN, "smb3 decryption failed");
287 		return (-1);
288 	}
289 
290 	return (0);
291 }
292 
293 /*
294  * SMB2 credits determine how many simultaneous commands the
295  * client may issue, and bounds the range of message IDs those
296  * commands may use.  With multi-credit support, commands may
297  * use ranges of message IDs, where the credits used by each
298  * command are proportional to their data transfer size.
299  *
300  * Every command may request an increase or decrease of
301  * the currently granted credits, based on the difference
302  * between the credit request and the credit charge.
303  * [MS-SMB2] 3.3.1.2 Algorithm for the Granting of Credits
304  *
305  * Most commands have credit_request=1, credit_charge=1,
306  * which keeps the credit grant unchanged.
307  *
308  * All we're really doing here (for now) is reducing the
309  * credit_response if the client requests a credit increase
310  * that would take their credit over the maximum, and
311  * limiting the decrease so they don't run out of credits.
312  *
313  * Later, this could do something dynamic based on load.
314  *
315  * One other non-obvious bit about credits: We keep the
316  * session s_max_credits low until the 1st authentication,
317  * at which point we'll set the normal maximum_credits.
318  * Some clients ask for more credits with session setup,
319  * and we need to handle that requested increase _after_
320  * the command-specific handler returns so it won't be
321  * restricted to the lower (pre-auth) limit.
322  */
323 static inline void
324 smb2_credit_decrease(smb_request_t *sr)
325 {
326 	smb_session_t *session = sr->session;
327 	uint16_t cur, d;
328 
329 	mutex_enter(&session->s_credits_mutex);
330 	cur = session->s_cur_credits;
331 
332 	/* Handle credit decrease. */
333 	d = sr->smb2_credit_charge - sr->smb2_credit_request;
334 	cur -= d;
335 	if (cur & 0x8000) {
336 		/*
337 		 * underflow (bad credit charge or request)
338 		 * leave credits unchanged (response=charge)
339 		 */
340 		cur = session->s_cur_credits;
341 		sr->smb2_credit_response = sr->smb2_credit_charge;
342 		DTRACE_PROBE1(smb2__credit__neg, smb_request_t *, sr);
343 	}
344 
345 	/*
346 	 * The server MUST ensure that the number of credits
347 	 * held by the client is never reduced to zero.
348 	 * [MS-SMB2] 3.3.1.2
349 	 */
350 	if (cur == 0) {
351 		cur = 1;
352 		sr->smb2_credit_response += 1;
353 		DTRACE_PROBE1(smb2__credit__min, smb_request_t *, sr);
354 	}
355 
356 	DTRACE_PROBE3(smb2__credit__decrease,
357 	    smb_request_t *, sr, int, (int)cur,
358 	    int, (int)session->s_cur_credits);
359 
360 	session->s_cur_credits = cur;
361 	mutex_exit(&session->s_credits_mutex);
362 }
363 
364 /*
365  * Second half of SMB2 credit handling (increases)
366  */
367 static inline void
368 smb2_credit_increase(smb_request_t *sr)
369 {
370 	smb_session_t *session = sr->session;
371 	uint16_t cur, d;
372 
373 	mutex_enter(&session->s_credits_mutex);
374 	cur = session->s_cur_credits;
375 
376 	/* Handle credit increase. */
377 	d = sr->smb2_credit_request - sr->smb2_credit_charge;
378 	cur += d;
379 
380 	/*
381 	 * If new credits would be above max,
382 	 * reduce the credit grant.
383 	 */
384 	if (cur > session->s_max_credits) {
385 		d = cur - session->s_max_credits;
386 		cur = session->s_max_credits;
387 		sr->smb2_credit_response -= d;
388 		DTRACE_PROBE1(smb2__credit__max, smb_request_t, sr);
389 	}
390 
391 	DTRACE_PROBE3(smb2__credit__increase,
392 	    smb_request_t *, sr, int, (int)cur,
393 	    int, (int)session->s_cur_credits);
394 
395 	session->s_cur_credits = cur;
396 	mutex_exit(&session->s_credits_mutex);
397 }
398 
399 /*
400  * Record some statistics:  latency, rx bytes, tx bytes
401  * per:  server, session & kshare.
402  */
403 static inline void
404 smb2_record_stats(smb_request_t *sr, smb_disp_stats_t *sds, boolean_t tx_only)
405 {
406 	hrtime_t	dt;
407 	int64_t		rxb;
408 	int64_t		txb;
409 
410 	dt = gethrtime() - sr->sr_time_start;
411 	rxb = (int64_t)(sr->command.chain_offset - sr->smb2_cmd_hdr);
412 	txb = (int64_t)(sr->reply.chain_offset - sr->smb2_reply_hdr);
413 
414 	if (!tx_only) {
415 		smb_server_inc_req(sr->sr_server);
416 		smb_latency_add_sample(&sds->sdt_lat, dt);
417 		atomic_add_64(&sds->sdt_rxb, rxb);
418 	}
419 	atomic_add_64(&sds->sdt_txb, txb);
420 }
421 
422 /*
423  * smb2sr_work
424  *
425  * This function processes each SMB command in the current request
426  * (which may be a compound request) building a reply containing
427  * SMB reply messages, one-to-one with the SMB commands.  Some SMB
428  * commands (change notify, blocking locks) may require both an
429  * "interim response" and a later "async response" at completion.
430  * In such cases, we'll encode the interim response in the reply
431  * compound we're building, and put the (now async) command on a
432  * list of commands that need further processing.  After we've
433  * finished processing the commands in this compound and building
434  * the compound reply, we'll send the compound reply, and finally
435  * process the list of async commands.
436  *
437  * As we work our way through the compound request and reply,
438  * we need to keep track of the bounds of the current request
439  * and reply.  For the request, this uses an MBC_SHADOW_CHAIN
440  * that begins at smb2_cmd_hdr.  The reply is appended to the
441  * sr->reply chain starting at smb2_reply_hdr.
442  *
443  * This function must always free the smb request, or arrange
444  * for it to be completed and free'd later (if SDRC_SR_KEPT).
445  */
446 void
447 smb2sr_work(struct smb_request *sr)
448 {
449 	const smb_disp_entry_t	*sdd;
450 	smb_disp_stats_t	*sds;
451 	smb_session_t		*session;
452 	uint32_t		msg_len;
453 	uint16_t		cmd_idx;
454 	int			rc = 0;
455 	boolean_t		disconnect = B_FALSE;
456 	boolean_t		related;
457 
458 	session = sr->session;
459 
460 	ASSERT(sr->smb2_async == B_FALSE);
461 	ASSERT(sr->tid_tree == 0);
462 	ASSERT(sr->uid_user == 0);
463 	ASSERT(sr->fid_ofile == 0);
464 	sr->smb_fid = (uint16_t)-1;
465 	sr->smb2_status = 0;
466 
467 	/* temporary until we identify a user */
468 	sr->user_cr = zone_kcred();
469 
470 cmd_start:
471 	/*
472 	 * Note that we don't check sr_state here and abort the
473 	 * compound if cancelled (etc.) because some SMB2 command
474 	 * handlers need to do work even when cancelled.
475 	 *
476 	 * We treat some status codes as if "sticky", meaning
477 	 * once they're set after some command handler returns,
478 	 * all remaining commands get this status without even
479 	 * calling the command-specific handler.
480 	 */
481 	if (sr->smb2_status != NT_STATUS_CANCELLED &&
482 	    sr->smb2_status != NT_STATUS_INSUFFICIENT_RESOURCES)
483 		sr->smb2_status = 0;
484 
485 	/*
486 	 * Decode the request header
487 	 *
488 	 * Most problems with decoding will result in the error
489 	 * STATUS_INVALID_PARAMETER.  If the decoding problem
490 	 * prevents continuing, we'll close the connection.
491 	 * [MS-SMB2] 3.3.5.2.6 Handling Incorrectly Formatted...
492 	 */
493 	sr->smb2_cmd_hdr = sr->command.chain_offset;
494 	if ((rc = smb2_decode_header(sr)) != 0) {
495 		cmn_err(CE_WARN, "clnt %s bad SMB2 header",
496 		    session->ip_addr_str);
497 		disconnect = B_TRUE;
498 		goto cleanup;
499 	}
500 
501 	/*
502 	 * The SMB2_FLAGS_SERVER_TO_REDIR should only appear
503 	 * in messages from the server back to the client.
504 	 */
505 	if ((sr->smb2_hdr_flags & SMB2_FLAGS_SERVER_TO_REDIR) != 0) {
506 		cmn_err(CE_WARN, "clnt %s bad SMB2 flags",
507 		    session->ip_addr_str);
508 		disconnect = B_TRUE;
509 		goto cleanup;
510 	}
511 	related = (sr->smb2_hdr_flags & SMB2_FLAGS_RELATED_OPERATIONS);
512 	sr->smb2_hdr_flags |= SMB2_FLAGS_SERVER_TO_REDIR;
513 	if (sr->smb2_hdr_flags & SMB2_FLAGS_ASYNC_COMMAND) {
514 		/* Probably an async cancel. */
515 		DTRACE_PROBE1(smb2__dispatch__async, smb_request_t *, sr);
516 	} else if (sr->smb2_async) {
517 		/* Previous command in compound went async. */
518 		sr->smb2_hdr_flags |= SMB2_FLAGS_ASYNC_COMMAND;
519 		sr->smb2_async_id = SMB2_ASYNCID(sr);
520 	}
521 
522 	/*
523 	 * In case we bail out with an error before we get to the
524 	 * section that computes the credit grant, initialize the
525 	 * response header fields so that credits won't change.
526 	 * Note: SMB 2.02 clients may send credit charge zero.
527 	 */
528 	if (sr->smb2_credit_charge == 0)
529 		sr->smb2_credit_charge = 1;
530 	sr->smb2_credit_response = sr->smb2_credit_charge;
531 
532 	/*
533 	 * Write a tentative reply header.
534 	 *
535 	 * We could just leave this blank, but if we're using the
536 	 * mdb module feature that extracts packets, it's useful
537 	 * to have the header mostly correct here.
538 	 *
539 	 * If we have already exhausted the output space, then the
540 	 * client is trying something funny.  Log it and kill 'em.
541 	 */
542 	sr->smb2_next_reply = 0;
543 	ASSERT((sr->reply.chain_offset & 7) == 0);
544 	sr->smb2_reply_hdr = sr->reply.chain_offset;
545 	if ((rc = smb2_encode_header(sr, B_FALSE)) != 0) {
546 		cmn_err(CE_WARN, "clnt %s excessive reply",
547 		    session->ip_addr_str);
548 		disconnect = B_TRUE;
549 		goto cleanup;
550 	}
551 
552 	/*
553 	 * Figure out the length of data following the SMB2 header.
554 	 * It ends at either the next SMB2 header if there is one
555 	 * (smb2_next_command != 0) or at the end of the message.
556 	 */
557 	if (sr->smb2_next_command != 0) {
558 		/* [MS-SMB2] says this is 8-byte aligned */
559 		msg_len = sr->smb2_next_command;
560 		if ((msg_len & 7) != 0 || (msg_len < SMB2_HDR_SIZE) ||
561 		    ((sr->smb2_cmd_hdr + msg_len) > sr->command.max_bytes)) {
562 			cmn_err(CE_WARN, "clnt %s bad SMB2 next cmd",
563 			    session->ip_addr_str);
564 			disconnect = B_TRUE;
565 			goto cleanup;
566 		}
567 	} else {
568 		msg_len = sr->command.max_bytes - sr->smb2_cmd_hdr;
569 	}
570 
571 	/*
572 	 * Setup a shadow chain for this SMB2 command, starting
573 	 * with the header and ending at either the next command
574 	 * or the end of the message.  The signing check below
575 	 * needs the entire SMB2 command.  After that's done, we
576 	 * advance chain_offset to the end of the header where
577 	 * the command specific handlers continue decoding.
578 	 */
579 	(void) MBC_SHADOW_CHAIN(&sr->smb_data, &sr->command,
580 	    sr->smb2_cmd_hdr, msg_len);
581 
582 	/*
583 	 * We will consume the data for this request from smb_data.
584 	 * That effectively consumes msg_len bytes from sr->command
585 	 * but doesn't update its chain_offset, so we need to update
586 	 * that here to make later received bytes accounting work.
587 	 */
588 	sr->command.chain_offset = sr->smb2_cmd_hdr + msg_len;
589 	ASSERT(sr->command.chain_offset <= sr->command.max_bytes);
590 
591 	/*
592 	 * Validate the commmand code, get dispatch table entries.
593 	 * [MS-SMB2] 3.3.5.2.6 Handling Incorrectly Formatted...
594 	 *
595 	 * The last slot in the dispatch table is used to handle
596 	 * invalid commands.  Same for statistics.
597 	 */
598 	if (sr->smb2_cmd_code < SMB2_INVALID_CMD)
599 		cmd_idx = sr->smb2_cmd_code;
600 	else
601 		cmd_idx = SMB2_INVALID_CMD;
602 	sdd = &smb2_disp_table[cmd_idx];
603 	sds = &session->s_server->sv_disp_stats2[cmd_idx];
604 
605 	/*
606 	 * If this command is NOT "related" to the previous,
607 	 * clear out the UID, TID, FID state that might be
608 	 * left over from the previous command.
609 	 *
610 	 * If the command IS related, any new IDs are ignored,
611 	 * and we simply continue with the previous user, tree,
612 	 * and open file.
613 	 */
614 	if (!related) {
615 		/*
616 		 * Drop user, tree, file; carefully ordered to
617 		 * avoid dangling references: file, tree, user
618 		 */
619 		if (sr->fid_ofile != NULL) {
620 			smb_ofile_release(sr->fid_ofile);
621 			sr->fid_ofile = NULL;
622 		}
623 		if (sr->tid_tree != NULL) {
624 			smb_tree_release(sr->tid_tree);
625 			sr->tid_tree = NULL;
626 		}
627 		if (sr->uid_user != NULL) {
628 			smb_user_release(sr->uid_user);
629 			sr->uid_user = NULL;
630 			sr->user_cr = zone_kcred();
631 		}
632 	}
633 
634 	/*
635 	 * Make sure we have a user and tree as needed
636 	 * according to the flags for the this command.
637 	 * Note that we may have inherited these.
638 	 */
639 	if ((sdd->sdt_flags & SDDF_SUPPRESS_UID) == 0) {
640 		/*
641 		 * This command requires a user session.
642 		 */
643 		if (related) {
644 			/*
645 			 * Previous command should have given us a user.
646 			 * [MS-SMB2] 3.3.5.2 Handling Related Requests
647 			 */
648 			if (sr->uid_user == NULL) {
649 				smb2sr_put_error(sr,
650 				    NT_STATUS_INVALID_PARAMETER);
651 				goto cmd_done;
652 			}
653 			sr->smb2_ssnid = sr->uid_user->u_ssnid;
654 		} else {
655 			/*
656 			 * Lookup the UID
657 			 * [MS-SMB2] 3.3.5.2 Verifying the Session
658 			 */
659 			ASSERT(sr->uid_user == NULL);
660 			/*
661 			 * [MS-SMB2] 3.3.5.2.7 Handling Compounded Requests
662 			 *
663 			 * If this is an encrypted compound request,
664 			 * ensure that the ssnid in the request
665 			 * is the same as the tform ssnid if this
666 			 * message is not related.
667 			 *
668 			 * The reasons this is done seem to apply equally
669 			 * to uncompounded requests, so we apply it to all.
670 			 */
671 
672 			if (sr->encrypted &&
673 			    sr->smb2_ssnid != sr->smb3_tform_ssnid) {
674 				disconnect = B_TRUE;
675 				goto cleanup; /* just do this for now */
676 			}
677 
678 			sr->uid_user = smb_session_lookup_ssnid(session,
679 			    sr->smb2_ssnid);
680 			if (sr->uid_user == NULL) {
681 				smb2sr_put_error(sr,
682 				    NT_STATUS_USER_SESSION_DELETED);
683 				goto cmd_done;
684 			}
685 
686 			/*
687 			 * [MS-SMB2] 3.3.5.2.9 Verifying the Session
688 			 *
689 			 * If we're talking 3.x,
690 			 * RejectUnencryptedAccess is TRUE,
691 			 * Session.EncryptData is TRUE,
692 			 * and the message wasn't encrypted,
693 			 * return ACCESS_DENIED.
694 			 *
695 			 * Note that Session.EncryptData can only be TRUE when
696 			 * we're talking 3.x.
697 			 */
698 
699 			if (sr->uid_user->u_encrypt ==
700 			    SMB_CONFIG_REQUIRED &&
701 			    !sr->encrypted) {
702 				smb2sr_put_error(sr,
703 				    NT_STATUS_ACCESS_DENIED);
704 				goto cmd_done;
705 			}
706 
707 			sr->user_cr = smb_user_getcred(sr->uid_user);
708 		}
709 		ASSERT(sr->uid_user != NULL);
710 
711 		/*
712 		 * Encrypt if:
713 		 * - The cmd is not SESSION_SETUP or NEGOTIATE; AND
714 		 * - Session.EncryptData is TRUE
715 		 *
716 		 * Those commands suppress UID, so they can't be the cmd here.
717 		 */
718 		if (sr->uid_user->u_encrypt != SMB_CONFIG_DISABLED &&
719 		    sr->tform_ssn == NULL) {
720 			smb_user_hold_internal(sr->uid_user);
721 			sr->tform_ssn = sr->uid_user;
722 			sr->smb3_tform_ssnid = sr->smb2_ssnid;
723 		}
724 	}
725 
726 	if ((sdd->sdt_flags & SDDF_SUPPRESS_TID) == 0) {
727 		/*
728 		 * This command requires a tree connection.
729 		 */
730 		if (related) {
731 			/*
732 			 * Previous command should have given us a tree.
733 			 * [MS-SMB2] 3.3.5.2 Handling Related Requests
734 			 */
735 			if (sr->tid_tree == NULL) {
736 				smb2sr_put_error(sr,
737 				    NT_STATUS_INVALID_PARAMETER);
738 				goto cmd_done;
739 			}
740 			sr->smb_tid = sr->tid_tree->t_tid;
741 		} else {
742 			/*
743 			 * Lookup the TID
744 			 * [MS-SMB2] 3.3.5.2 Verifying the Tree Connect
745 			 */
746 			ASSERT(sr->tid_tree == NULL);
747 			sr->tid_tree = smb_session_lookup_tree(session,
748 			    sr->smb_tid);
749 			if (sr->tid_tree == NULL) {
750 				smb2sr_put_error(sr,
751 				    NT_STATUS_NETWORK_NAME_DELETED);
752 				goto cmd_done;
753 			}
754 
755 			/*
756 			 * [MS-SMB2] 3.3.5.2.11 Verifying the Tree Connect
757 			 *
758 			 * If we support 3.x, RejectUnencryptedAccess is TRUE,
759 			 * if Tcon.EncryptData is TRUE or
760 			 * global EncryptData is TRUE and
761 			 * the message wasn't encrypted, or
762 			 * if Tcon.EncryptData is TRUE or
763 			 * global EncryptData is TRUE or
764 			 * the request was encrypted and
765 			 * the connection doesn't support encryption,
766 			 * return ACCESS_DENIED.
767 			 *
768 			 * If RejectUnencryptedAccess is TRUE, we force
769 			 * max_protocol to at least 3.0. Additionally,
770 			 * if the tree requires encryption, we don't care
771 			 * what we support, we still enforce encryption.
772 			 */
773 			if (sr->tid_tree->t_encrypt == SMB_CONFIG_REQUIRED &&
774 			    (!sr->encrypted ||
775 			    (session->srv_cap & SMB2_CAP_ENCRYPTION) == 0)) {
776 				smb2sr_put_error(sr,
777 				    NT_STATUS_ACCESS_DENIED);
778 				goto cmd_done;
779 			}
780 		}
781 		ASSERT(sr->tid_tree != NULL);
782 
783 		/*
784 		 * Encrypt if:
785 		 * - The cmd is not TREE_CONNECT; AND
786 		 * - Tree.EncryptData is TRUE
787 		 *
788 		 * TREE_CONNECT suppresses TID, so that can't be the cmd here.
789 		 * NOTE: assumes we can't have a tree without a user
790 		 */
791 		if (sr->tid_tree->t_encrypt != SMB_CONFIG_DISABLED &&
792 		    sr->tform_ssn == NULL) {
793 			smb_user_hold_internal(sr->uid_user);
794 			sr->tform_ssn = sr->uid_user;
795 			sr->smb3_tform_ssnid = sr->smb2_ssnid;
796 		}
797 	}
798 
799 	/*
800 	 * SMB2 signature verification, two parts:
801 	 * (a) Require SMB2_FLAGS_SIGNED (for most request types)
802 	 * (b) If SMB2_FLAGS_SIGNED is set, check the signature.
803 	 * [MS-SMB2] 3.3.5.2.4 Verifying the Signature
804 	 */
805 
806 	/*
807 	 * No user session means no signature check.  That's OK,
808 	 * i.e. for commands marked SDDF_SUPPRESS_UID above.
809 	 * Note, this also means we won't sign the reply.
810 	 */
811 	if (sr->uid_user == NULL)
812 		sr->smb2_hdr_flags &= ~SMB2_FLAGS_SIGNED;
813 
814 	/*
815 	 * The SDDF_SUPPRESS_UID dispatch is set for requests that
816 	 * don't need a UID (user).  These also don't require a
817 	 * signature check here.
818 	 *
819 	 * [MS-SMB2] 3.3.5.2.4 Verifying the Signature
820 	 *
821 	 * If the packet was successfully decrypted, the message
822 	 * signature has already been verified, so we can skip this.
823 	 */
824 	if ((sdd->sdt_flags & SDDF_SUPPRESS_UID) == 0 &&
825 	    !sr->encrypted && sr->uid_user != NULL &&
826 	    (sr->uid_user->u_sign_flags & SMB_SIGNING_ENABLED) != 0) {
827 		/*
828 		 * If the request is signed, check the signature.
829 		 * Otherwise, if signing is required, deny access.
830 		 */
831 		if ((sr->smb2_hdr_flags & SMB2_FLAGS_SIGNED) != 0) {
832 			rc = smb2_sign_check_request(sr);
833 			if (rc != 0) {
834 				DTRACE_PROBE1(smb2__sign__check,
835 				    smb_request_t *, sr);
836 				smb2sr_put_error(sr, NT_STATUS_ACCESS_DENIED);
837 				goto cmd_done;
838 			}
839 		} else if (
840 		    (sr->uid_user->u_sign_flags & SMB_SIGNING_CHECK) != 0) {
841 			smb2sr_put_error(sr, NT_STATUS_ACCESS_DENIED);
842 			goto cmd_done;
843 		}
844 	}
845 
846 	/*
847 	 * Now that the signing check is done with smb_data,
848 	 * advance past the SMB2 header we decoded earlier.
849 	 * This leaves sr->smb_data correctly positioned
850 	 * for command-specific decoding in the dispatch
851 	 * function called next.
852 	 */
853 	sr->smb_data.chain_offset = sr->smb2_cmd_hdr + SMB2_HDR_SIZE;
854 
855 	/*
856 	 * Credit adjustments (decrease)
857 	 *
858 	 * If we've gone async, credit adjustments were done
859 	 * when we sent the interim reply.
860 	 */
861 	if (!sr->smb2_async) {
862 		sr->smb2_credit_response = sr->smb2_credit_request;
863 		if (sr->smb2_credit_request < sr->smb2_credit_charge) {
864 			smb2_credit_decrease(sr);
865 		}
866 	}
867 
868 	/*
869 	 * The real work: call the SMB2 command handler
870 	 * (except for "sticky" smb2_status - see above)
871 	 */
872 	sr->sr_time_start = gethrtime();
873 	rc = SDRC_SUCCESS;
874 	if (sr->smb2_status == 0) {
875 		/* NB: not using pre_op */
876 		rc = (*sdd->sdt_function)(sr);
877 		/* NB: not using post_op */
878 	} else {
879 		smb2sr_put_error(sr, sr->smb2_status);
880 	}
881 
882 	/*
883 	 * When the sdt_function returns SDRC_SR_KEPT, it means
884 	 * this SR may have been passed to another thread so we
885 	 * MUST NOT touch it anymore.
886 	 */
887 	if (rc == SDRC_SR_KEPT)
888 		return;
889 
890 	MBC_FLUSH(&sr->raw_data);
891 
892 	/*
893 	 * Credit adjustments (increase)
894 	 */
895 	if (!sr->smb2_async) {
896 		if (sr->smb2_credit_request > sr->smb2_credit_charge) {
897 			smb2_credit_increase(sr);
898 		}
899 	}
900 
901 cmd_done:
902 	switch (rc) {
903 	case SDRC_SUCCESS:
904 		break;
905 	default:
906 		/*
907 		 * SMB2 does not use the other dispatch return codes.
908 		 * If we see something else, log an event so we'll
909 		 * know something is returning bogus status codes.
910 		 * If you see these in the log, use dtrace to find
911 		 * the code returning something else.
912 		 */
913 #ifdef	DEBUG
914 		cmn_err(CE_NOTE, "handler for %u returned 0x%x",
915 		    sr->smb2_cmd_code, rc);
916 #endif
917 		smb2sr_put_error(sr, NT_STATUS_INTERNAL_ERROR);
918 		break;
919 	case SDRC_ERROR:
920 		/*
921 		 * Many command handlers return SDRC_ERROR for any
922 		 * problems decoding the request, and don't bother
923 		 * setting smb2_status.  For those cases, the best
924 		 * status return would be "invalid parameter".
925 		 */
926 		if (sr->smb2_status == 0)
927 			sr->smb2_status = NT_STATUS_INVALID_PARAMETER;
928 		smb2sr_put_error(sr, sr->smb2_status);
929 		break;
930 	case SDRC_DROP_VC:
931 		disconnect = B_TRUE;
932 		goto cleanup;
933 
934 	case SDRC_NO_REPLY:
935 		/* will free sr */
936 		goto cleanup;
937 	}
938 
939 	/*
940 	 * Pad the reply to align(8) if there will be another.
941 	 * (We don't compound async replies.)
942 	 */
943 	if (!sr->smb2_async && sr->smb2_next_command != 0)
944 		(void) smb_mbc_put_align(&sr->reply, 8);
945 
946 	/*
947 	 * Record some statistics.  Uses:
948 	 *   rxb = command.chain_offset - smb2_cmd_hdr;
949 	 *   txb = reply.chain_offset - smb2_reply_hdr;
950 	 * which at this point represent the current cmd/reply.
951 	 *
952 	 * Note: If async, this does txb only, and
953 	 * skips the smb_latency_add_sample() calls.
954 	 */
955 	smb2_record_stats(sr, sds, sr->smb2_async);
956 
957 	/*
958 	 * If there's a next command, figure out where it starts,
959 	 * and fill in the next header offset for the reply.
960 	 * Note: We sanity checked smb2_next_command above.
961 	 */
962 	if (sr->smb2_next_command != 0) {
963 		sr->command.chain_offset =
964 		    sr->smb2_cmd_hdr + sr->smb2_next_command;
965 		sr->smb2_next_reply =
966 		    sr->reply.chain_offset - sr->smb2_reply_hdr;
967 	} else {
968 		ASSERT(sr->smb2_next_reply == 0);
969 	}
970 
971 	/*
972 	 * Overwrite the (now final) SMB2 header for this response.
973 	 */
974 	(void) smb2_encode_header(sr, B_TRUE);
975 
976 	/* Don't sign if we're going to encrypt */
977 	if (sr->tform_ssn == NULL &&
978 	    (sr->smb2_hdr_flags & SMB2_FLAGS_SIGNED) != 0)
979 		smb2_sign_reply(sr);
980 
981 	/*
982 	 * Non-async runs the whole compound before send.
983 	 * When we've gone async, send each individually.
984 	 */
985 	if (!sr->smb2_async && sr->smb2_next_command != 0)
986 		goto cmd_start;
987 
988 	/*
989 	 * If we have a durable handle, and this operation updated
990 	 * the nvlist, write it out (before smb2_send_reply).
991 	 */
992 	if (sr->dh_nvl_dirty) {
993 		sr->dh_nvl_dirty = B_FALSE;
994 		smb2_dh_update_nvfile(sr);
995 	}
996 
997 	smb2_send_reply(sr);
998 	if (sr->smb2_async && sr->smb2_next_command != 0) {
999 		MBC_FLUSH(&sr->reply);	/* New reply buffer. */
1000 		ASSERT(sr->reply.max_bytes == sr->session->reply_max_bytes);
1001 		goto cmd_start;
1002 	}
1003 
1004 cleanup:
1005 	if (disconnect)
1006 		smb_session_disconnect(session);
1007 
1008 	/*
1009 	 * Do "postwork" for oplock (and maybe other things)
1010 	 */
1011 	if (sr->sr_postwork != NULL)
1012 		smb2sr_run_postwork(sr);
1013 
1014 	mutex_enter(&sr->sr_mutex);
1015 	sr->sr_state = SMB_REQ_STATE_COMPLETED;
1016 	mutex_exit(&sr->sr_mutex);
1017 
1018 	smb_request_free(sr);
1019 }
1020 
1021 /*
1022  * Build interim responses for the current and all following
1023  * requests in this compound, then send the compound response,
1024  * leaving the SR state so that smb2sr_work() can continue its
1025  * processing of this compound in "async mode".
1026  *
1027  * If we agree to "go async", this should return STATUS_SUCCESS.
1028  * Otherwise return STATUS_INSUFFICIENT_RESOURCES for this and
1029  * all requests following this request.  (See the comments re.
1030  * "sticky" smb2_status values in smb2sr_work).
1031  *
1032  * Note: the Async ID we assign here is arbitrary, and need only
1033  * be unique among pending async responses on this connection, so
1034  * this just uses a modified messageID, which is already unique.
1035  *
1036  * Credits:  All credit changes should happen via the interim
1037  * responses, so we have to manage credits here.  After this
1038  * returns to smb2sr_work, the final replies for all these
1039  * commands will have smb2_credit_response = smb2_credit_charge
1040  * (meaning no further changes to the clients' credits).
1041  */
1042 uint32_t
1043 smb2sr_go_async(smb_request_t *sr)
1044 {
1045 	smb_session_t *session;
1046 	smb_disp_stats_t *sds;
1047 	uint16_t cmd_idx;
1048 	int32_t saved_com_offset;
1049 	uint32_t saved_cmd_hdr;
1050 	uint16_t saved_cred_resp;
1051 	uint32_t saved_hdr_flags;
1052 	uint32_t saved_reply_hdr;
1053 	uint32_t msg_len;
1054 	boolean_t disconnect = B_FALSE;
1055 
1056 	if (sr->smb2_async) {
1057 		/* already went async in some previous cmd. */
1058 		return (NT_STATUS_SUCCESS);
1059 	}
1060 	sr->smb2_async = B_TRUE;
1061 
1062 	/* The "server" session always runs async. */
1063 	session = sr->session;
1064 	if (session->sock == NULL)
1065 		return (NT_STATUS_SUCCESS);
1066 
1067 	sds = NULL;
1068 	saved_com_offset = sr->command.chain_offset;
1069 	saved_cmd_hdr = sr->smb2_cmd_hdr;
1070 	saved_cred_resp = sr->smb2_credit_response;
1071 	saved_hdr_flags = sr->smb2_hdr_flags;
1072 	saved_reply_hdr = sr->smb2_reply_hdr;
1073 
1074 	/*
1075 	 * The command-specific handler should not yet have put any
1076 	 * data in the reply except for the (place holder) header.
1077 	 */
1078 	if (sr->reply.chain_offset != sr->smb2_reply_hdr + SMB2_HDR_SIZE) {
1079 		ASSERT3U(sr->reply.chain_offset, ==,
1080 		    sr->smb2_reply_hdr + SMB2_HDR_SIZE);
1081 		return (NT_STATUS_INTERNAL_ERROR);
1082 	}
1083 
1084 	/*
1085 	 * Rewind to the start of the current header in both the
1086 	 * command and reply bufers, so the loop below can just
1087 	 * decode/encode just in every pass.  This means the
1088 	 * current command header is decoded again, but that
1089 	 * avoids having to special-case the first loop pass.
1090 	 */
1091 	sr->command.chain_offset = sr->smb2_cmd_hdr;
1092 	sr->reply.chain_offset = sr->smb2_reply_hdr;
1093 
1094 	/*
1095 	 * This command processing loop is a simplified version of
1096 	 * smb2sr_work() that just puts an "interim response" for
1097 	 * every command in the compound (NT_STATUS_PENDING).
1098 	 */
1099 cmd_start:
1100 	sr->smb2_status = NT_STATUS_PENDING;
1101 
1102 	/*
1103 	 * Decode the request header
1104 	 */
1105 	sr->smb2_cmd_hdr = sr->command.chain_offset;
1106 	if ((smb2_decode_header(sr)) != 0) {
1107 		cmn_err(CE_WARN, "clnt %s bad SMB2 header",
1108 		    session->ip_addr_str);
1109 		disconnect = B_TRUE;
1110 		goto cleanup;
1111 	}
1112 	sr->smb2_hdr_flags |=  (SMB2_FLAGS_SERVER_TO_REDIR |
1113 				SMB2_FLAGS_ASYNC_COMMAND);
1114 	sr->smb2_async_id = SMB2_ASYNCID(sr);
1115 
1116 	/*
1117 	 * In case we bail out...
1118 	 */
1119 	if (sr->smb2_credit_charge == 0)
1120 		sr->smb2_credit_charge = 1;
1121 	sr->smb2_credit_response = sr->smb2_credit_charge;
1122 
1123 	/*
1124 	 * Write a tentative reply header.
1125 	 */
1126 	sr->smb2_next_reply = 0;
1127 	ASSERT((sr->reply.chain_offset & 7) == 0);
1128 	sr->smb2_reply_hdr = sr->reply.chain_offset;
1129 	if ((smb2_encode_header(sr, B_FALSE)) != 0) {
1130 		cmn_err(CE_WARN, "clnt %s excessive reply",
1131 		    session->ip_addr_str);
1132 		disconnect = B_TRUE;
1133 		goto cleanup;
1134 	}
1135 
1136 	/*
1137 	 * Figure out the length of data...
1138 	 */
1139 	if (sr->smb2_next_command != 0) {
1140 		/* [MS-SMB2] says this is 8-byte aligned */
1141 		msg_len = sr->smb2_next_command;
1142 		if ((msg_len & 7) != 0 || (msg_len < SMB2_HDR_SIZE) ||
1143 		    ((sr->smb2_cmd_hdr + msg_len) > sr->command.max_bytes)) {
1144 			cmn_err(CE_WARN, "clnt %s bad SMB2 next cmd",
1145 			    session->ip_addr_str);
1146 			disconnect = B_TRUE;
1147 			goto cleanup;
1148 		}
1149 	} else {
1150 		msg_len = sr->command.max_bytes - sr->smb2_cmd_hdr;
1151 	}
1152 
1153 	/*
1154 	 * We just skip any data, so no shadow chain etc.
1155 	 */
1156 	sr->command.chain_offset = sr->smb2_cmd_hdr + msg_len;
1157 	ASSERT(sr->command.chain_offset <= sr->command.max_bytes);
1158 
1159 	/*
1160 	 * Validate the commmand code...
1161 	 */
1162 	if (sr->smb2_cmd_code < SMB2_INVALID_CMD)
1163 		cmd_idx = sr->smb2_cmd_code;
1164 	else
1165 		cmd_idx = SMB2_INVALID_CMD;
1166 	sds = &session->s_server->sv_disp_stats2[cmd_idx];
1167 
1168 	/*
1169 	 * Don't change (user, tree, file) because we want them
1170 	 * exactly as they were when we entered.  That also means
1171 	 * we may not have the right user in sr->uid_user for
1172 	 * signature checks, so leave that until smb2sr_work
1173 	 * runs these commands "for real".  Therefore, here
1174 	 * we behave as if: (sr->uid_user == NULL)
1175 	 */
1176 	sr->smb2_hdr_flags &= ~SMB2_FLAGS_SIGNED;
1177 
1178 	/*
1179 	 * Credit adjustments (decrease)
1180 	 *
1181 	 * NOTE: interim responses are not signed.
1182 	 * Any attacker can modify the credit grant
1183 	 * in the response. Because of this property,
1184 	 * it is no worse to assume the credit charge and grant
1185 	 * are sane without verifying the signature,
1186 	 * and that saves us a whole lot of work.
1187 	 * If the credits WERE modified, we'll find out
1188 	 * when we verify the signature later,
1189 	 * which nullifies any changes caused here.
1190 	 *
1191 	 * Skip this on the first command, because the
1192 	 * credit decrease was done by the caller.
1193 	 */
1194 	if (sr->smb2_cmd_hdr != saved_cmd_hdr) {
1195 		sr->smb2_credit_response = sr->smb2_credit_request;
1196 		if (sr->smb2_credit_request < sr->smb2_credit_charge) {
1197 			smb2_credit_decrease(sr);
1198 		}
1199 	}
1200 
1201 	/*
1202 	 * The real work: ... (would be here)
1203 	 */
1204 	smb2sr_put_error(sr, sr->smb2_status);
1205 
1206 	/*
1207 	 * Credit adjustments (increase)
1208 	 */
1209 	if (sr->smb2_credit_request > sr->smb2_credit_charge) {
1210 		smb2_credit_increase(sr);
1211 	}
1212 
1213 	/* cmd_done: label */
1214 
1215 	/*
1216 	 * Pad the reply to align(8) if there will be another.
1217 	 * This (interim) reply uses compounding.
1218 	 */
1219 	if (sr->smb2_next_command != 0)
1220 		(void) smb_mbc_put_align(&sr->reply, 8);
1221 
1222 	/*
1223 	 * Record some statistics.  Uses:
1224 	 *   rxb = command.chain_offset - smb2_cmd_hdr;
1225 	 *   txb = reply.chain_offset - smb2_reply_hdr;
1226 	 * which at this point represent the current cmd/reply.
1227 	 *
1228 	 * Note: We're doing smb_latency_add_sample() for all
1229 	 * remaining commands NOW, which means we won't include
1230 	 * the async part of their work in latency statistics.
1231 	 * That's intentional, as the async part of a command
1232 	 * would otherwise skew our latency statistics.
1233 	 */
1234 	smb2_record_stats(sr, sds, B_FALSE);
1235 
1236 	/*
1237 	 * If there's a next command, figure out where it starts,
1238 	 * and fill in the next header offset for the reply.
1239 	 * Note: We sanity checked smb2_next_command above.
1240 	 */
1241 	if (sr->smb2_next_command != 0) {
1242 		sr->command.chain_offset =
1243 		    sr->smb2_cmd_hdr + sr->smb2_next_command;
1244 		sr->smb2_next_reply =
1245 		    sr->reply.chain_offset - sr->smb2_reply_hdr;
1246 	} else {
1247 		ASSERT(sr->smb2_next_reply == 0);
1248 	}
1249 
1250 	/*
1251 	 * Overwrite the (now final) SMB2 header for this response.
1252 	 */
1253 	(void) smb2_encode_header(sr, B_TRUE);
1254 
1255 	/*
1256 	 * Process whole compound before sending.
1257 	 */
1258 	if (sr->smb2_next_command != 0)
1259 		goto cmd_start;
1260 	smb2_send_reply(sr);
1261 
1262 	ASSERT(!disconnect);
1263 
1264 cleanup:
1265 	/*
1266 	 * Restore caller's command processing state.
1267 	 */
1268 	sr->smb2_cmd_hdr = saved_cmd_hdr;
1269 	sr->command.chain_offset = saved_cmd_hdr;
1270 	(void) smb2_decode_header(sr);
1271 	sr->command.chain_offset = saved_com_offset;
1272 
1273 	sr->smb2_credit_response = saved_cred_resp;
1274 	sr->smb2_hdr_flags = saved_hdr_flags;
1275 	sr->smb2_status = NT_STATUS_SUCCESS;
1276 
1277 	/*
1278 	 * In here, the "disconnect" flag just means we had an
1279 	 * error decoding or encoding something.  Rather than
1280 	 * actually disconnect here, let's assume whatever
1281 	 * problem we encountered will be seen by the caller
1282 	 * as they continue processing the compound, and just
1283 	 * restore everything and return an error.
1284 	 */
1285 	if (disconnect) {
1286 		sr->smb2_async = B_FALSE;
1287 		sr->smb2_reply_hdr = saved_reply_hdr;
1288 		sr->reply.chain_offset = sr->smb2_reply_hdr;
1289 		(void) smb2_encode_header(sr, B_FALSE);
1290 		return (NT_STATUS_INVALID_PARAMETER);
1291 	}
1292 
1293 	/*
1294 	 * The compound reply buffer we sent is now gone.
1295 	 * Setup a new reply buffer for the caller.
1296 	 */
1297 	sr->smb2_hdr_flags |= SMB2_FLAGS_ASYNC_COMMAND;
1298 	sr->smb2_async_id = SMB2_ASYNCID(sr);
1299 	sr->smb2_next_reply = 0;
1300 	MBC_FLUSH(&sr->reply);
1301 	ASSERT(sr->reply.max_bytes == sr->session->reply_max_bytes);
1302 	ASSERT(sr->reply.chain_offset == 0);
1303 	sr->smb2_reply_hdr = 0;
1304 	(void) smb2_encode_header(sr, B_FALSE);
1305 
1306 	return (NT_STATUS_SUCCESS);
1307 }
1308 
1309 int
1310 smb3_decode_tform_header(smb_request_t *sr)
1311 {
1312 	uint16_t flags;
1313 	int rc;
1314 	uint32_t protocolid;
1315 
1316 	rc = smb_mbc_decodef(
1317 	    &sr->command, "l16c16cl..wq",
1318 	    &protocolid,	/*  l  */
1319 	    sr->smb2_sig,	/* 16c */
1320 	    sr->nonce,	/* 16c */
1321 	    &sr->msgsize,	/* l */
1322 	    /* reserved	  .. */
1323 	    &flags,		/* w */
1324 	    &sr->smb3_tform_ssnid); /* q */
1325 	if (rc)
1326 		return (rc);
1327 
1328 	ASSERT3U(protocolid, ==, SMB3_ENCRYPTED_MAGIC);
1329 
1330 	if (flags != 1) {
1331 #ifdef DEBUG
1332 		cmn_err(CE_NOTE, "flags field not 1: %x", flags);
1333 #endif
1334 		return (-1);
1335 	}
1336 
1337 	/*
1338 	 * MsgSize is the amount of data the client tell us to decrypt.
1339 	 * Make sure this value is not too big and not too small.
1340 	 */
1341 	if (sr->msgsize < SMB2_HDR_SIZE ||
1342 	    sr->msgsize > sr->session->cmd_max_bytes ||
1343 	    sr->msgsize > sr->command.max_bytes - SMB3_TFORM_HDR_SIZE)
1344 		return (-1);
1345 
1346 	return (rc);
1347 }
1348 
1349 int
1350 smb3_encode_tform_header(smb_request_t *sr, struct mbuf_chain *mbc)
1351 {
1352 	int rc;
1353 
1354 	/* Signature and Nonce are added in smb3_encrypt_sr */
1355 	rc = smb_mbc_encodef(
1356 	    mbc, "l32.lwwq",
1357 	    SMB3_ENCRYPTED_MAGIC, /* l */
1358 	    /* signature(16), nonce(16) 32. */
1359 	    sr->msgsize,	/* l */
1360 	    0, /* reserved	   w */
1361 	    1, /* flags		   w */
1362 	    sr->smb3_tform_ssnid); /* q */
1363 
1364 	return (rc);
1365 }
1366 
1367 int
1368 smb2_decode_header(smb_request_t *sr)
1369 {
1370 	uint32_t pid, tid;
1371 	uint16_t hdr_len;
1372 	int rc;
1373 
1374 	rc = smb_mbc_decodef(
1375 	    &sr->command, "Nwww..wwllqllq16c",
1376 	    &hdr_len,			/* w */
1377 	    &sr->smb2_credit_charge,	/* w */
1378 	    &sr->smb2_chan_seq,		/* w */
1379 	    /* reserved			  .. */
1380 	    &sr->smb2_cmd_code,		/* w */
1381 	    &sr->smb2_credit_request,	/* w */
1382 	    &sr->smb2_hdr_flags,	/* l */
1383 	    &sr->smb2_next_command,	/* l */
1384 	    &sr->smb2_messageid,	/* q */
1385 	    &pid,			/* l */
1386 	    &tid,			/* l */
1387 	    &sr->smb2_ssnid,		/* q */
1388 	    sr->smb2_sig);		/* 16c */
1389 	if (rc)
1390 		return (rc);
1391 
1392 	if (hdr_len != SMB2_HDR_SIZE)
1393 		return (-1);
1394 
1395 	if (sr->smb2_hdr_flags & SMB2_FLAGS_ASYNC_COMMAND) {
1396 		sr->smb2_async_id = pid |
1397 		    ((uint64_t)tid) << 32;
1398 		sr->smb_pid = 0;
1399 		sr->smb_tid = 0;
1400 	} else {
1401 		sr->smb2_async_id = 0;
1402 		sr->smb_pid = pid;
1403 		sr->smb_tid = (uint16_t)tid; /* XXX wide TIDs */
1404 	}
1405 
1406 	return (rc);
1407 }
1408 
1409 int
1410 smb2_encode_header(smb_request_t *sr, boolean_t overwrite)
1411 {
1412 	uint64_t pid_tid_aid; /* pid+tid, or async id */
1413 	int rc;
1414 
1415 	if (sr->smb2_hdr_flags & SMB2_FLAGS_ASYNC_COMMAND) {
1416 		pid_tid_aid = sr->smb2_async_id;
1417 	} else {
1418 		pid_tid_aid = sr->smb_pid |
1419 		    ((uint64_t)sr->smb_tid) << 32;
1420 	}
1421 
1422 	if (overwrite) {
1423 		rc = smb_mbc_poke(&sr->reply,
1424 		    sr->smb2_reply_hdr,
1425 		    "Nwwlwwllqqq16c",
1426 		    SMB2_HDR_SIZE,		/* w */
1427 		    sr->smb2_credit_charge,	/* w */
1428 		    sr->smb2_status,		/* l */
1429 		    sr->smb2_cmd_code,		/* w */
1430 		    sr->smb2_credit_response,	/* w */
1431 		    sr->smb2_hdr_flags,		/* l */
1432 		    sr->smb2_next_reply,	/* l */
1433 		    sr->smb2_messageid,		/* q */
1434 		    pid_tid_aid,		/* q */
1435 		    sr->smb2_ssnid,		/* q */
1436 		    sr->smb2_sig);		/* 16c */
1437 	} else {
1438 		rc = smb_mbc_encodef(&sr->reply,
1439 		    "Nwwlwwllqqq16c",
1440 		    SMB2_HDR_SIZE,		/* w */
1441 		    sr->smb2_credit_charge,	/* w */
1442 		    sr->smb2_status,		/* l */
1443 		    sr->smb2_cmd_code,		/* w */
1444 		    sr->smb2_credit_response,	/* w */
1445 		    sr->smb2_hdr_flags,		/* l */
1446 		    sr->smb2_next_reply,	/* l */
1447 		    sr->smb2_messageid,		/* q */
1448 		    pid_tid_aid,		/* q */
1449 		    sr->smb2_ssnid,		/* q */
1450 		    sr->smb2_sig);		/* 16c */
1451 	}
1452 
1453 	return (rc);
1454 }
1455 
1456 void
1457 smb2_send_reply(smb_request_t *sr)
1458 {
1459 	struct mbuf_chain enc_reply;
1460 	smb_session_t *session = sr->session;
1461 	void *tmpbuf;
1462 	size_t buflen;
1463 	struct mbuf_chain tmp;
1464 
1465 	/*
1466 	 * [MS-SMB2] 3.3.4.1.4 Encrypting the Message
1467 	 *
1468 	 * When the connection supports encryption and the dialect
1469 	 * is 3.x, encrypt if:
1470 	 * - The request was encrypted OR
1471 	 * - The cmd is not SESSION_SETUP or NEGOTIATE AND
1472 	 * -- Session.EncryptData is TRUE OR
1473 	 * -- The cmd is not TREE_CONNECT AND
1474 	 * --- Tree.EncryptData is TRUE
1475 	 *
1476 	 * This boils down to sr->tform_ssn != NULL, and the rest
1477 	 * is enforced when tform_ssn is set.
1478 	 */
1479 
1480 	if ((session->capabilities & SMB2_CAP_ENCRYPTION) == 0 ||
1481 	    sr->tform_ssn == NULL) {
1482 		if (smb_session_send(sr->session, 0, &sr->reply) == 0)
1483 			sr->reply.chain = 0;
1484 		return;
1485 	}
1486 
1487 	sr->msgsize = sr->reply.chain_offset;
1488 	(void) MBC_SHADOW_CHAIN(&tmp, &sr->reply,
1489 	    0, sr->msgsize);
1490 
1491 	buflen = SMB3_TFORM_HDR_SIZE + sr->msgsize;
1492 
1493 	/* taken from smb_request_init_command_mbuf */
1494 	tmpbuf = kmem_alloc(buflen, KM_SLEEP);
1495 	MBC_ATTACH_BUF(&enc_reply, tmpbuf, buflen);
1496 	enc_reply.flags = 0;
1497 	enc_reply.shadow_of = NULL;
1498 
1499 	if (smb3_encode_tform_header(sr, &enc_reply) != 0) {
1500 		cmn_err(CE_WARN, "couldn't encode transform header");
1501 		goto errout;
1502 	}
1503 	if (smb3_encrypt_sr(sr, &tmp, &enc_reply) != 0) {
1504 		cmn_err(CE_WARN, "smb3 encryption failed");
1505 		goto errout;
1506 	}
1507 
1508 	if (smb_session_send(sr->session, 0, &enc_reply) == 0)
1509 		enc_reply.chain = 0;
1510 	return;
1511 
1512 errout:
1513 	kmem_free(tmpbuf, buflen);
1514 	smb_session_disconnect(sr->session);
1515 }
1516 
1517 /*
1518  * This wrapper function exists to help catch calls to smbsr_status()
1519  * (which is SMB1-specific) in common code.  See smbsr_status().
1520  * If the log message below is seen, put a dtrace probe on this
1521  * function with a stack() action to see who is calling the SMB1
1522  * "put error" from common code, and fix it.
1523  */
1524 void
1525 smbsr_status_smb2(smb_request_t *sr, DWORD status)
1526 {
1527 	const char *name;
1528 
1529 	if (sr->smb2_cmd_code < SMB2__NCMDS)
1530 		name = smb2_disp_table[sr->smb2_cmd_code].sdt_name;
1531 	else
1532 		name = "<unknown>";
1533 #ifdef	DEBUG
1534 	cmn_err(CE_NOTE, "smbsr_status called for %s", name);
1535 #endif
1536 
1537 	smb2sr_put_error_data(sr, status, NULL);
1538 }
1539 
1540 void
1541 smb2sr_put_errno(struct smb_request *sr, int errnum)
1542 {
1543 	uint32_t status = smb_errno2status(errnum);
1544 	smb2sr_put_error_data(sr, status, NULL);
1545 }
1546 
1547 void
1548 smb2sr_put_error(smb_request_t *sr, uint32_t status)
1549 {
1550 	smb2sr_put_error_data(sr, status, NULL);
1551 }
1552 
1553 /*
1554  * Build an SMB2 error response.  [MS-SMB2] 2.2.2
1555  */
1556 void
1557 smb2sr_put_error_data(smb_request_t *sr, uint32_t status, mbuf_chain_t *mbc)
1558 {
1559 	DWORD len;
1560 
1561 	/*
1562 	 * The common dispatch code writes this when it
1563 	 * updates the SMB2 header before sending.
1564 	 */
1565 	sr->smb2_status = status;
1566 
1567 	/* Rewind to the end of the SMB header. */
1568 	sr->reply.chain_offset = sr->smb2_reply_hdr + SMB2_HDR_SIZE;
1569 
1570 	/*
1571 	 * NB: Must provide at least one byte of error data,
1572 	 * per [MS-SMB2] 2.2.2
1573 	 */
1574 	if (mbc != NULL && (len = MBC_LENGTH(mbc)) != 0) {
1575 		(void) smb_mbc_encodef(
1576 		    &sr->reply,
1577 		    "wwlC",
1578 		    9,	/* StructSize */	/* w */
1579 		    0,	/* reserved */		/* w */
1580 		    len,			/* l */
1581 		    mbc);			/* C */
1582 	} else {
1583 		(void) smb_mbc_encodef(
1584 		    &sr->reply,
1585 		    "wwl.",
1586 		    9,	/* StructSize */	/* w */
1587 		    0,	/* reserved */		/* w */
1588 		    0);				/* l. */
1589 	}
1590 }
1591 
1592 /*
1593  * smb2sr_lookup_fid
1594  *
1595  * Setup sr->fid_ofile, either inherited from a related command,
1596  * or obtained via FID lookup.  Similar inheritance logic as in
1597  * smb2sr_work.
1598  */
1599 uint32_t
1600 smb2sr_lookup_fid(smb_request_t *sr, smb2fid_t *fid)
1601 {
1602 	boolean_t related = sr->smb2_hdr_flags &
1603 	    SMB2_FLAGS_RELATED_OPERATIONS;
1604 
1605 	if (related) {
1606 		if (sr->fid_ofile == NULL)
1607 			return (NT_STATUS_INVALID_PARAMETER);
1608 		sr->smb_fid = sr->fid_ofile->f_fid;
1609 		return (0);
1610 	}
1611 
1612 	/*
1613 	 * If we could be sure this is called only once per cmd,
1614 	 * we could simply ASSERT(sr->fid_ofile == NULL) here.
1615 	 * However, there are cases where it can be called again
1616 	 * handling the same command, so let's tolerate that.
1617 	 */
1618 	if (sr->fid_ofile == NULL) {
1619 		sr->smb_fid = (uint16_t)fid->temporal;
1620 		sr->fid_ofile = smb_ofile_lookup_by_fid(sr, sr->smb_fid);
1621 	}
1622 	if (sr->fid_ofile == NULL ||
1623 	    sr->fid_ofile->f_persistid != fid->persistent)
1624 		return (NT_STATUS_FILE_CLOSED);
1625 
1626 	return (0);
1627 }
1628 
1629 /*
1630  * smb2_dispatch_stats_init
1631  *
1632  * Initializes dispatch statistics for SMB2.
1633  * See also smb_dispatch_stats_init(), which fills in
1634  * the lower part of the statistics array, from zero
1635  * through SMB_COM_NUM;
1636  */
1637 void
1638 smb2_dispatch_stats_init(smb_server_t *sv)
1639 {
1640 	smb_disp_stats_t *sds = sv->sv_disp_stats2;
1641 	smb_kstat_req_t *ksr;
1642 	int		i;
1643 
1644 	ksr = ((smbsrv_kstats_t *)sv->sv_ksp->ks_data)->ks_reqs2;
1645 
1646 	for (i = 0; i < SMB2__NCMDS; i++, ksr++) {
1647 		smb_latency_init(&sds[i].sdt_lat);
1648 		(void) strlcpy(ksr->kr_name, smb2_disp_table[i].sdt_name,
1649 		    sizeof (ksr->kr_name));
1650 	}
1651 }
1652 
1653 /*
1654  * smb2_dispatch_stats_fini
1655  *
1656  * Frees and destroyes the resources used for statistics.
1657  */
1658 void
1659 smb2_dispatch_stats_fini(smb_server_t *sv)
1660 {
1661 	smb_disp_stats_t *sds = sv->sv_disp_stats2;
1662 	int	i;
1663 
1664 	for (i = 0; i < SMB2__NCMDS; i++)
1665 		smb_latency_destroy(&sds[i].sdt_lat);
1666 }
1667 
1668 void
1669 smb2_dispatch_stats_update(smb_server_t *sv,
1670     smb_kstat_req_t *ksr, int first, int nreq)
1671 {
1672 	smb_disp_stats_t *sds = sv->sv_disp_stats2;
1673 	int	i;
1674 	int	last;
1675 
1676 	last = first + nreq - 1;
1677 
1678 	if ((first < SMB2__NCMDS) && (last < SMB2__NCMDS))  {
1679 		for (i = first; i <= last; i++, ksr++) {
1680 			ksr->kr_rxb = sds[i].sdt_rxb;
1681 			ksr->kr_txb = sds[i].sdt_txb;
1682 			mutex_enter(&sds[i].sdt_lat.ly_mutex);
1683 			ksr->kr_nreq = sds[i].sdt_lat.ly_a_nreq;
1684 			ksr->kr_sum = sds[i].sdt_lat.ly_a_sum;
1685 			ksr->kr_a_mean = sds[i].sdt_lat.ly_a_mean;
1686 			ksr->kr_a_stddev =
1687 			    sds[i].sdt_lat.ly_a_stddev;
1688 			ksr->kr_d_mean = sds[i].sdt_lat.ly_d_mean;
1689 			ksr->kr_d_stddev =
1690 			    sds[i].sdt_lat.ly_d_stddev;
1691 			sds[i].sdt_lat.ly_d_mean = 0;
1692 			sds[i].sdt_lat.ly_d_nreq = 0;
1693 			sds[i].sdt_lat.ly_d_stddev = 0;
1694 			sds[i].sdt_lat.ly_d_sum = 0;
1695 			mutex_exit(&sds[i].sdt_lat.ly_mutex);
1696 		}
1697 	}
1698 }
1699 
1700 /*
1701  * Append new_sr to the postwork queue.  sr->smb2_cmd_code encodes
1702  * the action that should be run by this sr.
1703  *
1704  * This queue is rarely used (and normally empty) so we're OK
1705  * using a simple "walk to tail and insert" here.
1706  */
1707 void
1708 smb2sr_append_postwork(smb_request_t *top_sr, smb_request_t *new_sr)
1709 {
1710 	smb_request_t *last_sr;
1711 
1712 	ASSERT(top_sr->session->dialect >= SMB_VERS_2_BASE);
1713 
1714 	last_sr = top_sr;
1715 	while (last_sr->sr_postwork != NULL)
1716 		last_sr = last_sr->sr_postwork;
1717 
1718 	last_sr->sr_postwork = new_sr;
1719 }
1720 
1721 /*
1722  * Run any "post work" that was appended to the main SR while it
1723  * was running.  This is called after the request has been sent
1724  * for the main SR, and used in cases i.e. the oplock code, where
1725  * we need to send something to the client only _after_ the main
1726  * sr request has gone out.
1727  */
1728 static void
1729 smb2sr_run_postwork(smb_request_t *top_sr)
1730 {
1731 	smb_request_t *post_sr;	/* the one we're running */
1732 	smb_request_t *next_sr;
1733 
1734 	while ((post_sr = top_sr->sr_postwork) != NULL) {
1735 		next_sr = post_sr->sr_postwork;
1736 		top_sr->sr_postwork = next_sr;
1737 		post_sr->sr_postwork = NULL;
1738 
1739 		post_sr->sr_worker = top_sr->sr_worker;
1740 		post_sr->sr_state = SMB_REQ_STATE_ACTIVE;
1741 
1742 		switch (post_sr->smb2_cmd_code) {
1743 		case SMB2_OPLOCK_BREAK:
1744 			smb_oplock_send_brk(post_sr);
1745 			break;
1746 		default:
1747 			ASSERT(0);
1748 		}
1749 
1750 		/*
1751 		 * If we have a durable handle, and this operation
1752 		 * updated the nvlist, write it out.
1753 		 */
1754 		if (post_sr->dh_nvl_dirty) {
1755 			post_sr->dh_nvl_dirty = B_FALSE;
1756 			smb2_dh_update_nvfile(post_sr);
1757 		}
1758 
1759 		post_sr->sr_state = SMB_REQ_STATE_COMPLETED;
1760 		smb_request_free(post_sr);
1761 	}
1762 }
1763