xref: /titanic_41/usr/src/lib/smbsrv/libsmbns/common/smbns_ads.c (revision 450396635f70344c58b6b1e4db38cf17ff34445c)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 #include <sys/param.h>
27 #include <ldap.h>
28 #include <stdlib.h>
29 #include <sys/types.h>
30 #include <sys/socket.h>
31 #include <netinet/in.h>
32 #include <arpa/inet.h>
33 #include <sys/time.h>
34 #include <netdb.h>
35 #include <pthread.h>
36 #include <unistd.h>
37 #include <arpa/nameser.h>
38 #include <resolv.h>
39 #include <sys/synch.h>
40 #include <string.h>
41 #include <strings.h>
42 #include <fcntl.h>
43 #include <sys/types.h>
44 #include <sys/stat.h>
45 #include <assert.h>
46 #include <sasl/sasl.h>
47 #include <note.h>
48 
49 #include <smbsrv/libsmbns.h>
50 #include <smbns_dyndns.h>
51 #include <smbns_krb.h>
52 
53 #define	SMB_ADS_MAXBUFLEN 100
54 #define	SMB_ADS_DN_MAX	300
55 #define	SMB_ADS_MAXMSGLEN 512
56 #define	SMB_ADS_COMPUTERS_CN "Computers"
57 #define	SMB_ADS_COMPUTER_NUM_ATTR 8
58 #define	SMB_ADS_SHARE_NUM_ATTR 3
59 #define	SMB_ADS_SITE_MAX MAXHOSTNAMELEN
60 
61 #define	SMB_ADS_MSDCS_SRV_DC_RR		"_ldap._tcp.dc._msdcs"
62 #define	SMB_ADS_MSDCS_SRV_SITE_RR	"_ldap._tcp.%s._sites.dc._msdcs"
63 
64 /*
65  * domainControllerFunctionality
66  *
67  * This rootDSE attribute indicates the functional level of the DC.
68  */
69 #define	SMB_ADS_ATTR_DCLEVEL	"domainControllerFunctionality"
70 #define	SMB_ADS_DCLEVEL_W2K	0
71 #define	SMB_ADS_DCLEVEL_W2K3	2
72 #define	SMB_ADS_DCLEVEL_W2K8	3
73 #define	SMB_ADS_DCLEVEL_W2K8_R2 4
74 
75 /*
76  * msDs-supportedEncryptionTypes (Windows Server 2008 only)
77  *
78  * This attribute defines the encryption types supported by the system.
79  * Encryption Types:
80  *  - DES cbc mode with CRC-32
81  *  - DES cbc mode with RSA-MD5
82  *  - ArcFour with HMAC/md5
83  *  - AES-128
84  *  - AES-256
85  */
86 #define	SMB_ADS_ATTR_ENCTYPES	"msDs-supportedEncryptionTypes"
87 #define	SMB_ADS_ENC_DES_CRC	1
88 #define	SMB_ADS_ENC_DES_MD5	2
89 #define	SMB_ADS_ENC_RC4		4
90 #define	SMB_ADS_ENC_AES128	8
91 #define	SMB_ADS_ENC_AES256	16
92 
93 #define	SMB_ADS_ATTR_SAMACCT	"sAMAccountName"
94 #define	SMB_ADS_ATTR_UPN	"userPrincipalName"
95 #define	SMB_ADS_ATTR_SPN	"servicePrincipalName"
96 #define	SMB_ADS_ATTR_CTL	"userAccountControl"
97 #define	SMB_ADS_ATTR_DNSHOST	"dNSHostName"
98 #define	SMB_ADS_ATTR_KVNO	"msDS-KeyVersionNumber"
99 #define	SMB_ADS_ATTR_DN		"distinguishedName"
100 
101 /*
102  * UserAccountControl flags: manipulate user account properties.
103  *
104  * The hexadecimal value of the following property flags are based on MSDN
105  * article # 305144.
106  */
107 #define	SMB_ADS_USER_ACCT_CTL_SCRIPT				0x00000001
108 #define	SMB_ADS_USER_ACCT_CTL_ACCOUNTDISABLE			0x00000002
109 #define	SMB_ADS_USER_ACCT_CTL_HOMEDIR_REQUIRED			0x00000008
110 #define	SMB_ADS_USER_ACCT_CTL_LOCKOUT				0x00000010
111 #define	SMB_ADS_USER_ACCT_CTL_PASSWD_NOTREQD			0x00000020
112 #define	SMB_ADS_USER_ACCT_CTL_PASSWD_CANT_CHANGE		0x00000040
113 #define	SMB_ADS_USER_ACCT_CTL_ENCRYPTED_TEXT_PWD_ALLOWED	0x00000080
114 #define	SMB_ADS_USER_ACCT_CTL_TMP_DUP_ACCT			0x00000100
115 #define	SMB_ADS_USER_ACCT_CTL_NORMAL_ACCT			0x00000200
116 #define	SMB_ADS_USER_ACCT_CTL_INTERDOMAIN_TRUST_ACCT		0x00000800
117 #define	SMB_ADS_USER_ACCT_CTL_WKSTATION_TRUST_ACCT		0x00001000
118 #define	SMB_ADS_USER_ACCT_CTL_SRV_TRUST_ACCT			0x00002000
119 #define	SMB_ADS_USER_ACCT_CTL_DONT_EXPIRE_PASSWD		0x00010000
120 #define	SMB_ADS_USER_ACCT_CTL_MNS_LOGON_ACCT			0x00020000
121 #define	SMB_ADS_USER_ACCT_CTL_SMARTCARD_REQUIRED		0x00040000
122 #define	SMB_ADS_USER_ACCT_CTL_TRUSTED_FOR_DELEGATION		0x00080000
123 #define	SMB_ADS_USER_ACCT_CTL_NOT_DELEGATED			0x00100000
124 #define	SMB_ADS_USER_ACCT_CTL_USE_DES_KEY_ONLY			0x00200000
125 #define	SMB_ADS_USER_ACCT_CTL_DONT_REQ_PREAUTH			0x00400000
126 #define	SMB_ADS_USER_ACCT_CTL_PASSWD_EXPIRED			0x00800000
127 #define	SMB_ADS_USER_ACCT_CTL_TRUSTED_TO_AUTH_FOR_DELEGATION	0x01000000
128 
129 /*
130  * Length of "dc=" prefix.
131  */
132 #define	SMB_ADS_DN_PREFIX_LEN	3
133 
134 static char *smb_ads_computer_objcls[] = {
135 	"top", "person", "organizationalPerson",
136 	"user", "computer", NULL
137 };
138 
139 static char *smb_ads_share_objcls[] = {
140 	"top", "leaf", "connectionPoint", "volume", NULL
141 };
142 
143 /* Cached ADS server to communicate with */
144 static smb_ads_host_info_t *smb_ads_cached_host_info = NULL;
145 static mutex_t smb_ads_cached_host_mtx;
146 
147 /*
148  * SMB ADS config cache is maintained to facilitate the detection of
149  * changes in configuration that is relevant to AD selection.
150  */
151 typedef struct smb_ads_config {
152 	char c_site[SMB_ADS_SITE_MAX];
153 	smb_inaddr_t c_pdc;
154 	mutex_t c_mtx;
155 } smb_ads_config_t;
156 
157 static smb_ads_config_t smb_ads_cfg;
158 
159 
160 /* attribute/value pair */
161 typedef struct smb_ads_avpair {
162 	char *avp_attr;
163 	char *avp_val;
164 } smb_ads_avpair_t;
165 
166 /* query status */
167 typedef enum smb_ads_qstat {
168 	SMB_ADS_STAT_ERR = -2,
169 	SMB_ADS_STAT_DUP,
170 	SMB_ADS_STAT_NOT_FOUND,
171 	SMB_ADS_STAT_FOUND
172 } smb_ads_qstat_t;
173 
174 typedef struct smb_ads_host_list {
175 	int ah_cnt;
176 	smb_ads_host_info_t *ah_list;
177 } smb_ads_host_list_t;
178 
179 static smb_ads_handle_t *smb_ads_open_main(char *, char *, char *);
180 static int smb_ads_add_computer(smb_ads_handle_t *, int, char *);
181 static int smb_ads_modify_computer(smb_ads_handle_t *, int, char *);
182 static int smb_ads_computer_op(smb_ads_handle_t *, int, int, char *);
183 static smb_ads_qstat_t smb_ads_lookup_computer_n_attr(smb_ads_handle_t *,
184     smb_ads_avpair_t *, int, char *);
185 static int smb_ads_update_computer_cntrl_attr(smb_ads_handle_t *, int, char *);
186 static krb5_kvno smb_ads_lookup_computer_attr_kvno(smb_ads_handle_t *, char *);
187 static void smb_ads_gen_machine_passwd(char *, int);
188 static void smb_ads_free_cached_host(void);
189 static int smb_ads_get_spnset(char *, char **);
190 static void smb_ads_free_spnset(char **);
191 static int smb_ads_alloc_attr(LDAPMod **, int);
192 static void smb_ads_free_attr(LDAPMod **);
193 static int smb_ads_get_dc_level(smb_ads_handle_t *);
194 static smb_ads_host_info_t *smb_ads_select_dc(smb_ads_host_list_t *);
195 static smb_ads_qstat_t smb_ads_find_computer(smb_ads_handle_t *, char *);
196 static smb_ads_qstat_t smb_ads_getattr(LDAP *, LDAPMessage *,
197     smb_ads_avpair_t *);
198 static smb_ads_qstat_t smb_ads_get_qstat(smb_ads_handle_t *, LDAPMessage *,
199     smb_ads_avpair_t *);
200 static boolean_t smb_ads_match_pdc(smb_ads_host_info_t *);
201 static boolean_t smb_ads_is_sought_host(smb_ads_host_info_t *, char *);
202 static boolean_t smb_ads_is_same_domain(char *, char *);
203 static boolean_t smb_ads_is_pdc_configured(void);
204 static smb_ads_host_info_t *smb_ads_dup_host_info(smb_ads_host_info_t *);
205 
206 /*
207  * smb_ads_init
208  *
209  * Initializes the ADS config cache.
210  */
211 void
212 smb_ads_init(void)
213 {
214 	(void) mutex_lock(&smb_ads_cfg.c_mtx);
215 	(void) smb_config_getstr(SMB_CI_ADS_SITE,
216 	    smb_ads_cfg.c_site, SMB_ADS_SITE_MAX);
217 	(void) smb_config_getip(SMB_CI_DOMAIN_SRV, &smb_ads_cfg.c_pdc);
218 	(void) mutex_unlock(&smb_ads_cfg.c_mtx);
219 }
220 
221 void
222 smb_ads_fini(void)
223 {
224 	smb_ads_free_cached_host();
225 }
226 
227 /*
228  * smb_ads_refresh
229  *
230  * This function will be called when smb/server SMF service is refreshed.
231  * Clearing the smb_ads_cached_host_info would allow the next DC
232  * discovery process to pick up an AD based on the new AD configuration.
233  */
234 void
235 smb_ads_refresh(void)
236 {
237 	char new_site[SMB_ADS_SITE_MAX];
238 	smb_inaddr_t new_pdc;
239 	boolean_t purge = B_FALSE;
240 
241 	(void) smb_config_getstr(SMB_CI_ADS_SITE, new_site, SMB_ADS_SITE_MAX);
242 	(void) smb_config_getip(SMB_CI_DOMAIN_SRV, &new_pdc);
243 	(void) mutex_lock(&smb_ads_cfg.c_mtx);
244 	if (utf8_strcasecmp(smb_ads_cfg.c_site, new_site)) {
245 		(void) strlcpy(smb_ads_cfg.c_site, new_site, SMB_ADS_SITE_MAX);
246 		purge = B_TRUE;
247 	}
248 
249 	smb_ads_cfg.c_pdc = new_pdc;
250 	(void) mutex_unlock(&smb_ads_cfg.c_mtx);
251 
252 	(void) mutex_lock(&smb_ads_cached_host_mtx);
253 	if (smb_ads_cached_host_info &&
254 	    smb_ads_is_pdc_configured() &&
255 	    !smb_ads_match_pdc(smb_ads_cached_host_info))
256 		purge = B_TRUE;
257 	(void) mutex_unlock(&smb_ads_cached_host_mtx);
258 
259 	if (purge)
260 		smb_ads_free_cached_host();
261 }
262 
263 
264 
265 static boolean_t
266 smb_ads_is_pdc_configured(void)
267 {
268 	boolean_t configured;
269 
270 	(void) mutex_lock(&smb_ads_cfg.c_mtx);
271 	configured = !smb_inet_iszero(&smb_ads_cfg.c_pdc);
272 	(void) mutex_unlock(&smb_ads_cfg.c_mtx);
273 
274 	return (configured);
275 }
276 
277 /*
278  * smb_ads_build_unc_name
279  *
280  * Construct the UNC name of the share object in the format of
281  * \\hostname.domain\shareUNC
282  *
283  * Returns 0 on success, -1 on error.
284  */
285 int
286 smb_ads_build_unc_name(char *unc_name, int maxlen,
287     const char *hostname, const char *shareUNC)
288 {
289 	char my_domain[MAXHOSTNAMELEN];
290 
291 	if (smb_getfqdomainname(my_domain, sizeof (my_domain)) != 0)
292 		return (-1);
293 
294 	(void) snprintf(unc_name, maxlen, "\\\\%s.%s\\%s",
295 	    hostname, my_domain, shareUNC);
296 	return (0);
297 }
298 
299 /*
300  * smb_ads_ldap_ping
301  *
302  * This is used to bind to an ADS server to see
303  * if it is still alive.
304  *
305  * Returns:
306  *   -1: error
307  *    0: successful
308  */
309 /*ARGSUSED*/
310 static int
311 smb_ads_ldap_ping(smb_ads_host_info_t *ads_host)
312 {
313 	int ldversion = LDAP_VERSION3, status, timeoutms = 5 * 1000;
314 	LDAP *ld = NULL;
315 
316 	ld = ldap_init(ads_host->name, ads_host->port);
317 	if (ld == NULL)
318 		return (-1);
319 
320 	ldversion = LDAP_VERSION3;
321 	(void) ldap_set_option(ld, LDAP_OPT_PROTOCOL_VERSION, &ldversion);
322 	/* setup TCP/IP connect timeout */
323 	(void) ldap_set_option(ld, LDAP_X_OPT_CONNECT_TIMEOUT, &timeoutms);
324 
325 	status = ldap_bind_s(ld, "", NULL, LDAP_AUTH_SIMPLE);
326 
327 	if (status != LDAP_SUCCESS) {
328 		(void) ldap_unbind(ld);
329 		return (-1);
330 	}
331 
332 	(void) ldap_unbind(ld);
333 
334 	return (0);
335 }
336 
337 /*
338  * The cached ADS host is no longer valid if one of the following criteria
339  * is satisfied:
340  *
341  * 1) not in the specified domain
342  * 2) not the sought host (if specified)
343  * 3) not reachable
344  *
345  * The caller is responsible for acquiring the smb_ads_cached_host_mtx lock
346  * prior to calling this function.
347  *
348  * Return B_TRUE if the cache host is still valid. Otherwise, return B_FALSE.
349  */
350 static boolean_t
351 smb_ads_validate_cache_host(char *domain, char *srv)
352 {
353 	if (!smb_ads_cached_host_info)
354 		return (B_FALSE);
355 
356 	if (!smb_ads_is_same_domain(smb_ads_cached_host_info->name, domain))
357 		return (B_FALSE);
358 
359 	if (smb_ads_ldap_ping(smb_ads_cached_host_info) == 0) {
360 		if (!srv)
361 			return (B_TRUE);
362 
363 		if (smb_ads_is_sought_host(smb_ads_cached_host_info, srv))
364 			return (B_TRUE);
365 	}
366 
367 	return (B_FALSE);
368 }
369 
370 /*
371  * smb_ads_is_sought_host
372  *
373  * Returns true, if the sought host name matches the input host (host) name.
374  * The sought host is expected to be in Fully Qualified Domain Name (FQDN)
375  * format.
376  */
377 static boolean_t
378 smb_ads_is_sought_host(smb_ads_host_info_t *host, char *sought_host_name)
379 {
380 	if ((host == NULL) || (sought_host_name == NULL))
381 		return (B_FALSE);
382 
383 	if (utf8_strcasecmp(host->name, sought_host_name))
384 		return (B_FALSE);
385 
386 	return (B_TRUE);
387 }
388 
389 /*
390  * smb_ads_match_hosts_same_domain
391  *
392  * Returns true, if the cached ADS host is in the same domain as the
393  * current (given) domain.
394  */
395 static boolean_t
396 smb_ads_is_same_domain(char *cached_host_name, char *current_domain)
397 {
398 	char *cached_host_domain;
399 
400 	if ((cached_host_name == NULL) || (current_domain == NULL))
401 		return (B_FALSE);
402 
403 	cached_host_domain = strchr(cached_host_name, '.');
404 	if (cached_host_domain == NULL)
405 		return (B_FALSE);
406 
407 	++cached_host_domain;
408 	if (utf8_strcasecmp(cached_host_domain, current_domain))
409 		return (B_FALSE);
410 
411 	return (B_TRUE);
412 }
413 
414 /*
415  * smb_ads_skip_ques_sec
416  * Skips the question section.
417  */
418 static int
419 smb_ads_skip_ques_sec(int qcnt, uchar_t **ptr, uchar_t *eom)
420 {
421 	int i, len;
422 
423 	for (i = 0; i < qcnt; i++) {
424 		if ((len = dn_skipname(*ptr, eom)) < 0)
425 			return (-1);
426 
427 		*ptr += len + QFIXEDSZ;
428 	}
429 
430 	return (0);
431 }
432 
433 /*
434  * smb_ads_decode_host_ans_sec
435  * Decodes ADS hosts, priority, weight and port number from the answer
436  * section based on the current buffer pointer.
437  */
438 static int
439 smb_ads_decode_host_ans_sec(int ans_cnt, uchar_t **ptr, uchar_t *eom,
440     uchar_t *buf, smb_ads_host_info_t *ads_host_list)
441 {
442 	int i, len;
443 	smb_ads_host_info_t *ads_host;
444 
445 	for (i = 0; i < ans_cnt; i++) {
446 		ads_host = &ads_host_list[i];
447 
448 		if ((len = dn_skipname(*ptr, eom)) < 0)
449 			return (-1);
450 
451 
452 		*ptr += len;
453 
454 		/* skip type, class, ttl */
455 		*ptr += 8;
456 		/* data size */
457 		*ptr += 2;
458 
459 		/* Get priority, weight */
460 		/* LINTED: E_CONSTANT_CONDITION */
461 		NS_GET16(ads_host->priority, *ptr);
462 		/* LINTED: E_CONSTANT_CONDITION */
463 		NS_GET16(ads_host->weight, *ptr);
464 
465 		/* port */
466 		/* LINTED: E_CONSTANT_CONDITION */
467 		NS_GET16(ads_host->port, *ptr);
468 		/* domain name */
469 		len = dn_expand(buf, eom, *ptr, ads_host->name, MAXHOSTNAMELEN);
470 		if (len < 0)
471 			return (-1);
472 
473 		*ptr += len;
474 	}
475 
476 	return (0);
477 }
478 
479 /*
480  * smb_ads_skip_auth_sec
481  * Skips the authority section.
482  */
483 static int
484 smb_ads_skip_auth_sec(int ns_cnt, uchar_t **ptr, uchar_t *eom)
485 {
486 	int i, len;
487 	uint16_t size;
488 
489 	for (i = 0; i < ns_cnt; i++) {
490 		if ((len = dn_skipname(*ptr, eom)) < 0)
491 			return (-1);
492 
493 		*ptr += len;
494 		/* skip type, class, ttl */
495 		*ptr += 8;
496 		/* get len of data */
497 		/* LINTED: E_CONSTANT_CONDITION */
498 		NS_GET16(size, *ptr);
499 		if ((*ptr + size) > eom)
500 			return (-1);
501 
502 		*ptr += size;
503 	}
504 
505 	return (0);
506 }
507 
508 /*
509  * smb_ads_decode_host_ip
510  *
511  * Decodes ADS hosts and IP Addresses from the additional section based
512  * on the current buffer pointer.
513  */
514 static int
515 smb_ads_decode_host_ip(int addit_cnt, int ans_cnt, uchar_t **ptr,
516     uchar_t *eom, uchar_t *buf, smb_ads_host_info_t *ads_host_list)
517 {
518 	int i, j, len;
519 	smb_inaddr_t ipaddr;
520 	char hostname[MAXHOSTNAMELEN];
521 	char *name;
522 	uint16_t size = 0;
523 
524 	for (i = 0; i < addit_cnt; i++) {
525 
526 		/* domain name */
527 		len = dn_expand(buf, eom, *ptr, hostname, MAXHOSTNAMELEN);
528 		if (len < 0)
529 			return (-1);
530 
531 		*ptr += len;
532 
533 		/* skip type, class, TTL, data len */
534 		*ptr += 8;
535 		/* LINTED: E_CONSTANT_CONDITION */
536 		NS_GET16(size, *ptr);
537 
538 		if (size == INADDRSZ) {
539 			/* LINTED: E_CONSTANT_CONDITION */
540 			NS_GET32(ipaddr.a_ipv4, *ptr);
541 			ipaddr.a_ipv4 = htonl(ipaddr.a_ipv4);
542 			ipaddr.a_family = AF_INET;
543 		} else if (size == IN6ADDRSZ) {
544 #ifdef BIG_ENDIAN
545 			bcopy(*ptr, &ipaddr.a_ipv6, IN6ADDRSZ);
546 #else
547 			for (i = 0; i < IN6ADDRSZ; i++)
548 				(uint8_t *)(ipaddr.a_ipv6)
549 				    [IN6ADDRSZ-1-i] = *(*ptr+i);
550 #endif
551 			ipaddr.a_family = AF_INET6;
552 		}
553 
554 		/*
555 		 * find the host in the list of DC records from
556 		 * the answer section, that matches the host in the
557 		 * additional section, and set its IP address.
558 		 */
559 		for (j = 0; j < ans_cnt; j++) {
560 			if ((name = ads_host_list[j].name) == NULL)
561 				continue;
562 			if (utf8_strcasecmp(name, hostname) == 0) {
563 				ads_host_list[j].ipaddr = ipaddr;
564 			}
565 		}
566 	}
567 	return (0);
568 }
569 
570 /*
571  * smb_ads_dup_host_info
572  *
573  * Duplicates the passed smb_ads_host_info_t structure.
574  * Caller must free memory allocated by this method.
575  *
576  * Returns a reference to the duplicated smb_ads_host_info_t structure.
577  * Returns NULL on error.
578  */
579 static smb_ads_host_info_t *
580 smb_ads_dup_host_info(smb_ads_host_info_t *ads_host)
581 {
582 	smb_ads_host_info_t *dup_host;
583 
584 	if (ads_host == NULL)
585 		return (NULL);
586 
587 	dup_host = malloc(sizeof (smb_ads_host_info_t));
588 
589 	if (dup_host != NULL)
590 		bcopy(ads_host, dup_host, sizeof (smb_ads_host_info_t));
591 
592 	return (dup_host);
593 }
594 
595 /*
596  * smb_ads_hlist_alloc
597  */
598 static smb_ads_host_list_t *
599 smb_ads_hlist_alloc(int count)
600 {
601 	int size;
602 	smb_ads_host_list_t *hlist;
603 
604 	if (count == 0)
605 		return (NULL);
606 
607 	size = sizeof (smb_ads_host_info_t) * count;
608 	hlist = (smb_ads_host_list_t *)malloc(sizeof (smb_ads_host_list_t));
609 	if (hlist == NULL)
610 		return (NULL);
611 
612 	hlist->ah_cnt = count;
613 	hlist->ah_list = (smb_ads_host_info_t *)malloc(size);
614 	if (hlist->ah_list == NULL) {
615 		free(hlist);
616 		return (NULL);
617 	}
618 
619 	bzero(hlist->ah_list, size);
620 	return (hlist);
621 }
622 
623 /*
624  * smb_ads_hlist_free
625  */
626 static void
627 smb_ads_hlist_free(smb_ads_host_list_t *host_list)
628 {
629 	if (host_list == NULL)
630 		return;
631 
632 	free(host_list->ah_list);
633 	free(host_list);
634 }
635 
636 /*
637  * smb_ads_query_dns_server
638  *
639  * This routine sends a DNS service location (SRV) query message to the
640  * DNS server via TCP to query it for a list of ADS server(s). Once a reply
641  * is received, the reply message is parsed to get the hostname. If there are IP
642  * addresses populated in the additional section then the additional section
643  * is parsed to obtain the IP addresses.
644  *
645  * The service location of _ldap._tcp.dc.msdcs.<ADS domain> is used to
646  * guarantee that Microsoft domain controllers are returned.  Microsoft domain
647  * controllers are also ADS servers.
648  *
649  * The ADS hostnames are stored in the answer section of the DNS reply message.
650  * The IP addresses are stored in the additional section.
651  *
652  * The DNS reply message may be in compress formed.  The compression is done
653  * on repeating domain name label in the message.  i.e hostname.
654  *
655  * Upon successful completion, host list of ADS server(s) is returned.
656  */
657 static smb_ads_host_list_t *
658 smb_ads_query_dns_server(char *domain, char *msdcs_svc_name)
659 {
660 	smb_ads_host_list_t *hlist = NULL;
661 	int len, qcnt, ans_cnt, ns_cnt, addit_cnt;
662 	uchar_t *ptr, *eom;
663 	struct __res_state res_state;
664 	union {
665 		HEADER hdr;
666 		uchar_t buf[NS_MAXMSG];
667 	} msg;
668 
669 	bzero(&res_state, sizeof (struct __res_state));
670 	if (res_ninit(&res_state) < 0)
671 		return (NULL);
672 
673 	/* use TCP */
674 	res_state.options |= RES_USEVC;
675 
676 	len = res_nquerydomain(&res_state, msdcs_svc_name, domain,
677 	    C_IN, T_SRV, msg.buf, sizeof (msg.buf));
678 
679 	if (len < 0) {
680 		syslog(LOG_NOTICE, "DNS query for %s failed: %s",
681 		    msdcs_svc_name, hstrerror(res_state.res_h_errno));
682 		res_ndestroy(&res_state);
683 		return (NULL);
684 	}
685 
686 	if (len > sizeof (msg.buf)) {
687 		syslog(LOG_NOTICE,
688 		    "DNS query for %s failed: too big", msdcs_svc_name);
689 		res_ndestroy(&res_state);
690 		return (NULL);
691 	}
692 
693 	/* parse the reply, skip header and question sections */
694 	ptr = msg.buf + sizeof (msg.hdr);
695 	eom = msg.buf + len;
696 
697 	/* check truncated message bit */
698 	if (msg.hdr.tc)
699 		syslog(LOG_NOTICE,
700 		    "DNS query for %s failed: truncated", msdcs_svc_name);
701 
702 	qcnt = ntohs(msg.hdr.qdcount);
703 	ans_cnt = ntohs(msg.hdr.ancount);
704 	ns_cnt = ntohs(msg.hdr.nscount);
705 	addit_cnt = ntohs(msg.hdr.arcount);
706 
707 	if (smb_ads_skip_ques_sec(qcnt, &ptr, eom) != 0) {
708 		res_ndestroy(&res_state);
709 		return (NULL);
710 	}
711 
712 	hlist = smb_ads_hlist_alloc(ans_cnt);
713 	if (hlist == NULL) {
714 		res_ndestroy(&res_state);
715 		return (NULL);
716 	}
717 
718 	/* walk through the answer section */
719 	if (smb_ads_decode_host_ans_sec(ans_cnt, &ptr, eom, msg.buf,
720 	    hlist->ah_list) != 0) {
721 		smb_ads_hlist_free(hlist);
722 		res_ndestroy(&res_state);
723 		return (NULL);
724 	}
725 
726 	/* check authority section */
727 	if (ns_cnt > 0) {
728 		if (smb_ads_skip_auth_sec(ns_cnt, &ptr, eom) != 0) {
729 			smb_ads_hlist_free(hlist);
730 			res_ndestroy(&res_state);
731 			return (NULL);
732 		}
733 	}
734 
735 	/*
736 	 * Check additional section to get IP address of ADS host.
737 	 */
738 	if (addit_cnt > 0) {
739 		if (smb_ads_decode_host_ip(addit_cnt, ans_cnt,
740 		    &ptr, eom, msg.buf, hlist->ah_list) != 0) {
741 			smb_ads_hlist_free(hlist);
742 			res_ndestroy(&res_state);
743 			return (NULL);
744 		}
745 	}
746 
747 	res_ndestroy(&res_state);
748 	return (hlist);
749 }
750 
751 /*
752  * smb_ads_get_site_service
753  *
754  * Gets the msdcs SRV RR for the specified site.
755  */
756 static void
757 smb_ads_get_site_service(char *site_service, size_t len)
758 {
759 	(void) mutex_lock(&smb_ads_cfg.c_mtx);
760 	if (*smb_ads_cfg.c_site == '\0')
761 		*site_service = '\0';
762 	else
763 		(void) snprintf(site_service, len,
764 		    SMB_ADS_MSDCS_SRV_SITE_RR, smb_ads_cfg.c_site);
765 
766 	(void) mutex_unlock(&smb_ads_cfg.c_mtx);
767 }
768 
769 /*
770  * smb_ads_getipnodebyname
771  *
772  * This method gets the IP address by doing a host name lookup.
773  */
774 static int
775 smb_ads_getipnodebyname(smb_ads_host_info_t *hentry)
776 {
777 	struct hostent *h;
778 	int error;
779 
780 	switch (hentry->ipaddr.a_family) {
781 	case AF_INET6:
782 		h = getipnodebyname(hentry->name, hentry->ipaddr.a_family,
783 		    AI_DEFAULT, &error);
784 		if (h == NULL || h->h_length != IPV6_ADDR_LEN)
785 			return (-1);
786 		break;
787 
788 	case AF_INET:
789 		h = getipnodebyname(hentry->name, hentry->ipaddr.a_family,
790 		    0, &error);
791 		if (h == NULL || h->h_length != INADDRSZ)
792 			return (-1);
793 		break;
794 
795 	default:
796 		return (-1);
797 	}
798 	bcopy(*(h->h_addr_list), &hentry->ipaddr.a_ip, h->h_length);
799 	freehostent(h);
800 	return (0);
801 }
802 
803 /*
804  * smb_ads_find_host
805  *
806  * Finds an ADS host in a given domain.
807  *
808  * If the cached host is valid, it will be used. Otherwise, a DC will
809  * be selected based on the following criteria:
810  *
811  * 1) pdc (aka preferred DC) configuration
812  * 2) AD site configuration - the scope of the DNS lookup will be
813  * restricted to the specified site.
814  * 3) DC on the same subnet
815  * 4) DC with the lowest priority/highest weight
816  *
817  * The above items are listed in decreasing preference order. The selected
818  * DC must be online.
819  *
820  * If this function is called during domain join, the specified kpasswd server
821  * takes precedence over preferred DC, AD site, and so on.
822  *
823  * Parameters:
824  *   domain: fully-qualified domain name.
825  *   kpasswd_srv: fully-quailifed hostname of the kpasswd server.
826  *
827  * Returns:
828  *   A copy of the cached host info is returned. The caller is responsible
829  *   for deallocating the memory returned by this function.
830  */
831 /*ARGSUSED*/
832 smb_ads_host_info_t *
833 smb_ads_find_host(char *domain, char *kpasswd_srv)
834 {
835 	int i;
836 	char site_service[MAXHOSTNAMELEN];
837 	smb_ads_host_list_t *hlist, *hlist2;
838 	smb_ads_host_info_t *hlistp = NULL, *host = NULL;
839 	smb_ads_host_info_t *found_kpasswd_srv = NULL;
840 	smb_ads_host_info_t *found_pdc = NULL;
841 
842 	if ((kpasswd_srv) && (*kpasswd_srv == '\0'))
843 		kpasswd_srv = NULL;
844 
845 	(void) mutex_lock(&smb_ads_cached_host_mtx);
846 	if (smb_ads_validate_cache_host(domain, kpasswd_srv)) {
847 		host = smb_ads_dup_host_info(smb_ads_cached_host_info);
848 		(void) mutex_unlock(&smb_ads_cached_host_mtx);
849 		return (host);
850 	}
851 
852 	(void) mutex_unlock(&smb_ads_cached_host_mtx);
853 	smb_ads_free_cached_host();
854 
855 	/*
856 	 * First look for ADS hosts in ADS site if configured.  Then try
857 	 * without ADS site info.
858 	 */
859 	hlist = NULL;
860 	smb_ads_get_site_service(site_service, MAXHOSTNAMELEN);
861 
862 	/*
863 	 * If we're given an AD, the DNS SRV RR lookup should not be restricted
864 	 * to the specified site since there is no guarantee that the specified
865 	 * AD is in the specified site.
866 	 */
867 	if (*site_service != '\0' && !kpasswd_srv &&
868 	    !smb_ads_is_pdc_configured())
869 		hlist = smb_ads_query_dns_server(domain, site_service);
870 
871 	if (!hlist)
872 		hlist = smb_ads_query_dns_server(domain,
873 		    SMB_ADS_MSDCS_SRV_DC_RR);
874 
875 	if ((hlist == NULL) || (hlist->ah_list == NULL) || (hlist->ah_cnt == 0))
876 		return (NULL);
877 
878 	for (i = 0, hlistp = hlist->ah_list; i < hlist->ah_cnt; i++) {
879 		/* Do a host lookup by hostname to get the IP address */
880 		if (smb_inet_iszero(&hlistp[i].ipaddr)) {
881 			if (smb_ads_getipnodebyname(&hlistp[i]) < 0)
882 				continue;
883 		}
884 
885 		if (smb_ads_is_sought_host(&hlistp[i], kpasswd_srv))
886 			found_kpasswd_srv = &hlistp[i];
887 
888 		if (smb_ads_match_pdc(&hlistp[i]))
889 			found_pdc = &hlistp[i];
890 	}
891 
892 	if (found_kpasswd_srv && smb_ads_ldap_ping(found_kpasswd_srv) == 0) {
893 		host = found_kpasswd_srv;
894 		goto update_cache;
895 	}
896 
897 	if (found_pdc && smb_ads_ldap_ping(found_pdc) == 0) {
898 		host = found_pdc;
899 		goto update_cache;
900 	}
901 
902 	/*
903 	 * If the specified DC (kpasswd_srv or pdc) is not found, fallback
904 	 * to find a DC in the specified AD site.
905 	 */
906 	if (*site_service != '\0' &&
907 	    (kpasswd_srv || smb_ads_is_pdc_configured())) {
908 		hlist2 = smb_ads_query_dns_server(domain, site_service);
909 		if (hlist2 && hlist2->ah_list && hlist2->ah_cnt != 0) {
910 			smb_ads_hlist_free(hlist);
911 			hlist = hlist2;
912 			hlistp = hlist->ah_list;
913 
914 			for (i = 0; i < hlist->ah_cnt; i++) {
915 				if (smb_inet_iszero(&hlistp[i].ipaddr) &&
916 				    smb_ads_getipnodebyname(&hlistp[i]) < 0)
917 						continue;
918 			}
919 		}
920 	}
921 
922 	/* Select DC from DC list */
923 	host = smb_ads_select_dc(hlist);
924 
925 update_cache:
926 	if (host) {
927 		(void) mutex_lock(&smb_ads_cached_host_mtx);
928 		if (!smb_ads_cached_host_info)
929 			smb_ads_cached_host_info = smb_ads_dup_host_info(host);
930 		host = smb_ads_dup_host_info(smb_ads_cached_host_info);
931 		(void) mutex_unlock(&smb_ads_cached_host_mtx);
932 	}
933 
934 	smb_ads_hlist_free(hlist);
935 	return (host);
936 }
937 
938 /*
939  * Return the number of dots in a string.
940  */
941 static int
942 smb_ads_count_dots(const char *s)
943 {
944 	int ndots = 0;
945 
946 	while (*s) {
947 		if (*s++ == '.')
948 			ndots++;
949 	}
950 
951 	return (ndots);
952 }
953 
954 /*
955  * Convert a domain name in dot notation to distinguished name format,
956  * for example: sun.com -> dc=sun,dc=com.
957  *
958  * Returns a pointer to an allocated buffer containing the distinguished
959  * name.
960  */
961 static char *
962 smb_ads_convert_domain(const char *domain_name)
963 {
964 	const char *s;
965 	char *dn_name;
966 	char buf[2];
967 	int ndots;
968 	int len;
969 
970 	if (domain_name == NULL || *domain_name == 0)
971 		return (NULL);
972 
973 	ndots = smb_ads_count_dots(domain_name);
974 	++ndots;
975 	len = strlen(domain_name) + (ndots * SMB_ADS_DN_PREFIX_LEN) + 1;
976 
977 	if ((dn_name = malloc(len)) == NULL)
978 		return (NULL);
979 
980 	bzero(dn_name, len);
981 	(void) strlcpy(dn_name, "dc=", len);
982 
983 	buf[1] = '\0';
984 	s = domain_name;
985 
986 	while (*s) {
987 		if (*s == '.') {
988 			(void) strlcat(dn_name, ",dc=", len);
989 		} else {
990 			buf[0] = *s;
991 			(void) strlcat(dn_name, buf, len);
992 		}
993 		++s;
994 	}
995 
996 	return (dn_name);
997 }
998 
999 /*
1000  * smb_ads_free_cached_host
1001  *
1002  * Free the memory use by the global smb_ads_cached_host_info & set it to NULL.
1003  */
1004 static void
1005 smb_ads_free_cached_host(void)
1006 {
1007 	(void) mutex_lock(&smb_ads_cached_host_mtx);
1008 	if (smb_ads_cached_host_info) {
1009 		free(smb_ads_cached_host_info);
1010 		smb_ads_cached_host_info = NULL;
1011 	}
1012 	(void) mutex_unlock(&smb_ads_cached_host_mtx);
1013 }
1014 
1015 /*
1016  * smb_ads_open
1017  * Open a LDAP connection to an ADS server if the system is in domain mode.
1018  * Acquire both Kerberos TGT and LDAP service tickets for the host principal.
1019  *
1020  * This function should only be called after the system is successfully joined
1021  * to a domain.
1022  */
1023 smb_ads_handle_t *
1024 smb_ads_open(void)
1025 {
1026 	char domain[MAXHOSTNAMELEN];
1027 
1028 	if (smb_config_get_secmode() != SMB_SECMODE_DOMAIN)
1029 		return (NULL);
1030 
1031 	if (smb_getfqdomainname(domain, MAXHOSTNAMELEN) != 0)
1032 		return (NULL);
1033 
1034 	return (smb_ads_open_main(domain, NULL, NULL));
1035 }
1036 
1037 static int
1038 smb_ads_saslcallback(LDAP *ld, unsigned flags, void *defaults, void *prompts)
1039 {
1040 	NOTE(ARGUNUSED(ld, defaults));
1041 	sasl_interact_t *interact;
1042 
1043 	if (prompts == NULL || flags != LDAP_SASL_INTERACTIVE)
1044 		return (LDAP_PARAM_ERROR);
1045 
1046 	/* There should be no extra arguemnts for SASL/GSSAPI authentication */
1047 	for (interact = prompts; interact->id != SASL_CB_LIST_END;
1048 	    interact++) {
1049 		interact->result = NULL;
1050 		interact->len = 0;
1051 	}
1052 	return (LDAP_SUCCESS);
1053 }
1054 
1055 /*
1056  * smb_ads_open_main
1057  * Open a LDAP connection to an ADS server.
1058  * If ADS is enabled and the administrative username, password, and
1059  * ADS domain are defined then query DNS to find an ADS server if this is the
1060  * very first call to this routine.  After an ADS server is found then this
1061  * server will be used everytime this routine is called until the system is
1062  * rebooted or the ADS server becomes unavailable then an ADS server will
1063  * be queried again.  After the connection is made then an ADS handle
1064  * is created to be returned.
1065  *
1066  * After the LDAP connection, the LDAP version will be set to 3 using
1067  * ldap_set_option().
1068  *
1069  * The LDAP connection is bound before the ADS handle is returned.
1070  * Parameters:
1071  *   domain - fully-qualified domain name
1072  *   user   - the user account for whom the Kerberos TGT ticket and ADS
1073  *            service tickets are acquired.
1074  *   password - password of the specified user
1075  *
1076  * Returns:
1077  *   NULL              : can't connect to ADS server or other errors
1078  *   smb_ads_handle_t* : handle to ADS server
1079  */
1080 static smb_ads_handle_t *
1081 smb_ads_open_main(char *domain, char *user, char *password)
1082 {
1083 	smb_ads_handle_t *ah;
1084 	LDAP *ld;
1085 	int version = 3;
1086 	smb_ads_host_info_t *ads_host = NULL;
1087 	int rc;
1088 
1089 	if (user != NULL) {
1090 		if (smb_kinit(user, password) == 0)
1091 			return (NULL);
1092 		user = NULL;
1093 		password = NULL;
1094 	}
1095 
1096 	ads_host = smb_ads_find_host(domain, NULL);
1097 	if (ads_host == NULL)
1098 		return (NULL);
1099 
1100 	ah = (smb_ads_handle_t *)malloc(sizeof (smb_ads_handle_t));
1101 	if (ah == NULL) {
1102 		free(ads_host);
1103 		return (NULL);
1104 	}
1105 
1106 	(void) memset(ah, 0, sizeof (smb_ads_handle_t));
1107 
1108 	if ((ld = ldap_init(ads_host->name, ads_host->port)) == NULL) {
1109 		smb_ads_free_cached_host();
1110 		free(ah);
1111 		free(ads_host);
1112 		return (NULL);
1113 	}
1114 
1115 	if (ldap_set_option(ld, LDAP_OPT_PROTOCOL_VERSION, &version)
1116 	    != LDAP_SUCCESS) {
1117 		smb_ads_free_cached_host();
1118 		free(ah);
1119 		free(ads_host);
1120 		(void) ldap_unbind(ld);
1121 		return (NULL);
1122 	}
1123 
1124 	(void) ldap_set_option(ld, LDAP_OPT_REFERRALS, LDAP_OPT_OFF);
1125 	ah->ld = ld;
1126 	ah->domain = strdup(domain);
1127 
1128 	if (ah->domain == NULL) {
1129 		smb_ads_close(ah);
1130 		free(ads_host);
1131 		return (NULL);
1132 	}
1133 
1134 	ah->domain_dn = smb_ads_convert_domain(domain);
1135 	if (ah->domain_dn == NULL) {
1136 		smb_ads_close(ah);
1137 		free(ads_host);
1138 		return (NULL);
1139 	}
1140 
1141 	ah->hostname = strdup(ads_host->name);
1142 	if (ah->hostname == NULL) {
1143 		smb_ads_close(ah);
1144 		free(ads_host);
1145 		return (NULL);
1146 	}
1147 	(void) mutex_lock(&smb_ads_cfg.c_mtx);
1148 	if (*smb_ads_cfg.c_site != '\0') {
1149 		if ((ah->site = strdup(smb_ads_cfg.c_site)) == NULL) {
1150 			smb_ads_close(ah);
1151 			(void) mutex_unlock(&smb_ads_cfg.c_mtx);
1152 			free(ads_host);
1153 			return (NULL);
1154 		}
1155 	} else {
1156 		ah->site = NULL;
1157 	}
1158 	(void) mutex_unlock(&smb_ads_cfg.c_mtx);
1159 
1160 	rc = ldap_sasl_interactive_bind_s(ah->ld, "", "GSSAPI", NULL, NULL,
1161 	    LDAP_SASL_INTERACTIVE, &smb_ads_saslcallback, NULL);
1162 	if (rc != LDAP_SUCCESS) {
1163 		syslog(LOG_ERR, "ldal_sasl_interactive_bind_s failed (%s)",
1164 		    ldap_err2string(rc));
1165 		smb_ads_close(ah);
1166 		free(ads_host);
1167 		return (NULL);
1168 	}
1169 
1170 	free(ads_host);
1171 	return (ah);
1172 }
1173 
1174 /*
1175  * smb_ads_close
1176  * Close connection to ADS server and free memory allocated for ADS handle.
1177  * LDAP unbind is called here.
1178  * Parameters:
1179  *   ah: handle to ADS server
1180  * Returns:
1181  *   void
1182  */
1183 void
1184 smb_ads_close(smb_ads_handle_t *ah)
1185 {
1186 	if (ah == NULL)
1187 		return;
1188 	/* close and free connection resources */
1189 	if (ah->ld)
1190 		(void) ldap_unbind(ah->ld);
1191 
1192 	free(ah->domain);
1193 	free(ah->domain_dn);
1194 	free(ah->hostname);
1195 	free(ah->site);
1196 	free(ah);
1197 }
1198 
1199 /*
1200  * smb_ads_alloc_attr
1201  *
1202  * Since the attrs is a null-terminated array, all elements
1203  * in the array (except the last one) will point to allocated
1204  * memory.
1205  */
1206 static int
1207 smb_ads_alloc_attr(LDAPMod *attrs[], int num)
1208 {
1209 	int i;
1210 
1211 	bzero(attrs, num * sizeof (LDAPMod *));
1212 	for (i = 0; i < (num - 1); i++) {
1213 		attrs[i] = (LDAPMod *)malloc(sizeof (LDAPMod));
1214 		if (attrs[i] == NULL) {
1215 			smb_ads_free_attr(attrs);
1216 			return (-1);
1217 		}
1218 	}
1219 
1220 	return (0);
1221 }
1222 
1223 /*
1224  * smb_ads_free_attr
1225  * Free memory allocated when publishing a share.
1226  * Parameters:
1227  *   attrs: an array of LDAPMod pointers
1228  * Returns:
1229  *   None
1230  */
1231 static void
1232 smb_ads_free_attr(LDAPMod *attrs[])
1233 {
1234 	int i;
1235 	for (i = 0; attrs[i]; i++) {
1236 		free(attrs[i]);
1237 	}
1238 }
1239 
1240 /*
1241  * smb_ads_get_spnset
1242  *
1243  * Derives the core set of SPNs based on the FQHN.
1244  * The spn_set is a null-terminated array of char pointers.
1245  *
1246  * Returns 0 upon success. Otherwise, returns -1.
1247  */
1248 static int
1249 smb_ads_get_spnset(char *fqhost, char **spn_set)
1250 {
1251 	int i;
1252 
1253 	bzero(spn_set, (SMBKRB5_SPN_IDX_MAX + 1) * sizeof (char *));
1254 	for (i = 0; i < SMBKRB5_SPN_IDX_MAX; i++) {
1255 		if ((spn_set[i] = smb_krb5_get_spn(i, fqhost)) == NULL) {
1256 			smb_ads_free_spnset(spn_set);
1257 			return (-1);
1258 		}
1259 	}
1260 
1261 	return (0);
1262 }
1263 
1264 /*
1265  * smb_ads_free_spnset
1266  *
1267  * Free the memory allocated for the set of SPNs.
1268  */
1269 static void
1270 smb_ads_free_spnset(char **spn_set)
1271 {
1272 	int i;
1273 	for (i = 0; spn_set[i]; i++)
1274 		free(spn_set[i]);
1275 }
1276 
1277 /*
1278  * smb_ads_add_share
1279  * Call by smb_ads_publish_share to create share object in ADS.
1280  * This routine specifies the attributes of an ADS LDAP share object. The first
1281  * attribute and values define the type of ADS object, the share object.  The
1282  * second attribute and value define the UNC of the share data for the share
1283  * object. The LDAP synchronous add command is used to add the object into ADS.
1284  * The container location to add the object needs to specified.
1285  * Parameters:
1286  *   ah          : handle to ADS server
1287  *   adsShareName: name of share object to be created in ADS
1288  *   shareUNC    : share name on NetForce
1289  *   adsContainer: location in ADS to create share object
1290  *
1291  * Returns:
1292  *   -1          : error
1293  *    0          : success
1294  */
1295 int
1296 smb_ads_add_share(smb_ads_handle_t *ah, const char *adsShareName,
1297     const char *unc_name, const char *adsContainer)
1298 {
1299 	LDAPMod *attrs[SMB_ADS_SHARE_NUM_ATTR];
1300 	int j = 0;
1301 	char *share_dn;
1302 	int len, ret;
1303 	char *unc_names[] = {(char *)unc_name, NULL};
1304 
1305 	len = 5 + strlen(adsShareName) + strlen(adsContainer) +
1306 	    strlen(ah->domain_dn) + 1;
1307 
1308 	share_dn = (char *)malloc(len);
1309 	if (share_dn == NULL)
1310 		return (-1);
1311 
1312 	(void) snprintf(share_dn, len, "cn=%s,%s,%s", adsShareName,
1313 	    adsContainer, ah->domain_dn);
1314 
1315 	if (smb_ads_alloc_attr(attrs, SMB_ADS_SHARE_NUM_ATTR) != 0) {
1316 		free(share_dn);
1317 		return (-1);
1318 	}
1319 
1320 	attrs[j]->mod_op = LDAP_MOD_ADD;
1321 	attrs[j]->mod_type = "objectClass";
1322 	attrs[j]->mod_values = smb_ads_share_objcls;
1323 
1324 	attrs[++j]->mod_op = LDAP_MOD_ADD;
1325 	attrs[j]->mod_type = "uNCName";
1326 	attrs[j]->mod_values = unc_names;
1327 
1328 	if ((ret = ldap_add_s(ah->ld, share_dn, attrs)) != LDAP_SUCCESS) {
1329 		smb_tracef("%s: ldap_add: %s", share_dn, ldap_err2string(ret));
1330 		smb_ads_free_attr(attrs);
1331 		free(share_dn);
1332 		return (ret);
1333 	}
1334 	free(share_dn);
1335 	smb_ads_free_attr(attrs);
1336 
1337 	return (0);
1338 }
1339 
1340 /*
1341  * smb_ads_del_share
1342  * Call by smb_ads_remove_share to remove share object from ADS.  The container
1343  * location to remove the object needs to specified.  The LDAP synchronous
1344  * delete command is used.
1345  * Parameters:
1346  *   ah          : handle to ADS server
1347  *   adsShareName: name of share object in ADS to be removed
1348  *   adsContainer: location of share object in ADS
1349  * Returns:
1350  *   -1          : error
1351  *    0          : success
1352  */
1353 static int
1354 smb_ads_del_share(smb_ads_handle_t *ah, const char *adsShareName,
1355     const char *adsContainer)
1356 {
1357 	char *share_dn;
1358 	int len, ret;
1359 
1360 	len = 5 + strlen(adsShareName) + strlen(adsContainer) +
1361 	    strlen(ah->domain_dn) + 1;
1362 
1363 	share_dn = (char *)malloc(len);
1364 	if (share_dn == NULL)
1365 		return (-1);
1366 
1367 	(void) snprintf(share_dn, len, "cn=%s,%s,%s", adsShareName,
1368 	    adsContainer, ah->domain_dn);
1369 	if ((ret = ldap_delete_s(ah->ld, share_dn)) != LDAP_SUCCESS) {
1370 		smb_tracef("ldap_delete: %s", ldap_err2string(ret));
1371 		free(share_dn);
1372 		return (-1);
1373 	}
1374 	free(share_dn);
1375 
1376 	return (0);
1377 }
1378 
1379 
1380 /*
1381  * smb_ads_escape_search_filter_chars
1382  *
1383  * This routine will escape the special characters found in a string
1384  * that will later be passed to the ldap search filter.
1385  *
1386  * RFC 1960 - A String Representation of LDAP Search Filters
1387  * 3.  String Search Filter Definition
1388  * If a value must contain one of the characters '*' OR '(' OR ')',
1389  * these characters
1390  * should be escaped by preceding them with the backslash '\' character.
1391  *
1392  * RFC 2252 - LDAP Attribute Syntax Definitions
1393  * a backslash quoting mechanism is used to escape
1394  * the following separator symbol character (such as "'", "$" or "#") if
1395  * it should occur in that string.
1396  */
1397 static int
1398 smb_ads_escape_search_filter_chars(const char *src, char *dst)
1399 {
1400 	int avail = SMB_ADS_MAXBUFLEN - 1; /* reserve a space for NULL char */
1401 
1402 	if (src == NULL || dst == NULL)
1403 		return (-1);
1404 
1405 	while (*src) {
1406 		if (!avail) {
1407 			*dst = 0;
1408 			return (-1);
1409 		}
1410 
1411 		switch (*src) {
1412 		case '\\':
1413 		case '\'':
1414 		case '$':
1415 		case '#':
1416 		case '*':
1417 		case '(':
1418 		case ')':
1419 			*dst++ = '\\';
1420 			avail--;
1421 			/* fall through */
1422 
1423 		default:
1424 			*dst++ = *src++;
1425 			avail--;
1426 		}
1427 	}
1428 
1429 	*dst = 0;
1430 
1431 	return (0);
1432 }
1433 
1434 /*
1435  * smb_ads_lookup_share
1436  * The search filter is set to search for a specific share name in the
1437  * specified ADS container.  The LDSAP synchronous search command is used.
1438  * Parameters:
1439  *   ah          : handle to ADS server
1440  *   adsShareName: name of share object in ADS to be searched
1441  *   adsContainer: location of share object in ADS
1442  * Returns:
1443  *   -1          : error
1444  *    0          : not found
1445  *    1          : found
1446  */
1447 int
1448 smb_ads_lookup_share(smb_ads_handle_t *ah, const char *adsShareName,
1449     const char *adsContainer, char *unc_name)
1450 {
1451 	char *attrs[4], filter[SMB_ADS_MAXBUFLEN];
1452 	char *share_dn;
1453 	int len, ret;
1454 	LDAPMessage *res;
1455 	char tmpbuf[SMB_ADS_MAXBUFLEN];
1456 
1457 	if (adsShareName == NULL || adsContainer == NULL)
1458 		return (-1);
1459 
1460 	len = 5 + strlen(adsShareName) + strlen(adsContainer) +
1461 	    strlen(ah->domain_dn) + 1;
1462 
1463 	share_dn = (char *)malloc(len);
1464 	if (share_dn == NULL)
1465 		return (-1);
1466 
1467 	(void) snprintf(share_dn, len, "cn=%s,%s,%s", adsShareName,
1468 	    adsContainer, ah->domain_dn);
1469 
1470 	res = NULL;
1471 	attrs[0] = "cn";
1472 	attrs[1] = "objectClass";
1473 	attrs[2] = "uNCName";
1474 	attrs[3] = NULL;
1475 
1476 	if (smb_ads_escape_search_filter_chars(unc_name, tmpbuf) != 0) {
1477 		free(share_dn);
1478 		return (-1);
1479 	}
1480 
1481 	(void) snprintf(filter, sizeof (filter),
1482 	    "(&(objectClass=volume)(uNCName=%s))", tmpbuf);
1483 
1484 	if ((ret = ldap_search_s(ah->ld, share_dn,
1485 	    LDAP_SCOPE_BASE, filter, attrs, 0, &res)) != LDAP_SUCCESS) {
1486 		if (ret != LDAP_NO_SUCH_OBJECT)
1487 			smb_tracef("%s: ldap_search: %s", share_dn,
1488 			    ldap_err2string(ret));
1489 
1490 		(void) ldap_msgfree(res);
1491 		free(share_dn);
1492 		return (0);
1493 	}
1494 
1495 	(void) free(share_dn);
1496 
1497 	/* no match is found */
1498 	if (ldap_count_entries(ah->ld, res) == 0) {
1499 		(void) ldap_msgfree(res);
1500 		return (0);
1501 	}
1502 
1503 	/* free the search results */
1504 	(void) ldap_msgfree(res);
1505 
1506 	return (1);
1507 }
1508 
1509 /*
1510  * smb_ads_publish_share
1511  * Publish share into ADS.  If a share name already exist in ADS in the same
1512  * container then the existing share object is removed before adding the new
1513  * share object.
1514  * Parameters:
1515  *   ah          : handle return from smb_ads_open
1516  *   adsShareName: name of share to be added to ADS directory
1517  *   shareUNC    : name of share on client, can be NULL to use the same name
1518  *                 as adsShareName
1519  *   adsContainer: location for share to be added in ADS directory, ie
1520  *                   ou=share_folder
1521  *   uncType     : use UNC_HOSTNAME to use hostname for UNC, use UNC_HOSTADDR
1522  *                   to use host ip addr for UNC.
1523  * Returns:
1524  *   -1          : error
1525  *    0          : success
1526  */
1527 int
1528 smb_ads_publish_share(smb_ads_handle_t *ah, const char *adsShareName,
1529     const char *shareUNC, const char *adsContainer, const char *hostname)
1530 {
1531 	int ret;
1532 	char unc_name[SMB_ADS_MAXBUFLEN];
1533 
1534 	if (adsShareName == NULL || adsContainer == NULL)
1535 		return (-1);
1536 
1537 	if (shareUNC == 0 || *shareUNC == 0)
1538 		shareUNC = adsShareName;
1539 
1540 	if (smb_ads_build_unc_name(unc_name, sizeof (unc_name),
1541 	    hostname, shareUNC) < 0)
1542 		return (-1);
1543 
1544 	ret = smb_ads_lookup_share(ah, adsShareName, adsContainer, unc_name);
1545 
1546 	switch (ret) {
1547 	case 1:
1548 		(void) smb_ads_del_share(ah, adsShareName, adsContainer);
1549 		ret = smb_ads_add_share(ah, adsShareName, unc_name,
1550 		    adsContainer);
1551 		break;
1552 
1553 	case 0:
1554 		ret = smb_ads_add_share(ah, adsShareName, unc_name,
1555 		    adsContainer);
1556 		if (ret == LDAP_ALREADY_EXISTS)
1557 			ret = -1;
1558 
1559 		break;
1560 
1561 	case -1:
1562 	default:
1563 		/* return with error code */
1564 		ret = -1;
1565 	}
1566 
1567 	return (ret);
1568 }
1569 
1570 /*
1571  * smb_ads_remove_share
1572  * Remove share from ADS.  A search is done first before explicitly removing
1573  * the share.
1574  * Parameters:
1575  *   ah          : handle return from smb_ads_open
1576  *   adsShareName: name of share to be removed from ADS directory
1577  *   adsContainer: location for share to be removed from ADS directory, ie
1578  *                   ou=share_folder
1579  * Returns:
1580  *   -1          : error
1581  *    0          : success
1582  */
1583 int
1584 smb_ads_remove_share(smb_ads_handle_t *ah, const char *adsShareName,
1585     const char *shareUNC, const char *adsContainer, const char *hostname)
1586 {
1587 	int ret;
1588 	char unc_name[SMB_ADS_MAXBUFLEN];
1589 
1590 	if (adsShareName == NULL || adsContainer == NULL)
1591 		return (-1);
1592 	if (shareUNC == 0 || *shareUNC == 0)
1593 		shareUNC = adsShareName;
1594 
1595 	if (smb_ads_build_unc_name(unc_name, sizeof (unc_name),
1596 	    hostname, shareUNC) < 0)
1597 		return (-1);
1598 
1599 	ret = smb_ads_lookup_share(ah, adsShareName, adsContainer, unc_name);
1600 	if (ret == 0)
1601 		return (0);
1602 	if (ret == -1)
1603 		return (-1);
1604 
1605 	return (smb_ads_del_share(ah, adsShareName, adsContainer));
1606 }
1607 
1608 /*
1609  * smb_ads_get_default_comp_container_dn
1610  *
1611  * Build the distinguished name for the default computer conatiner (i.e. the
1612  * pre-defined Computers container).
1613  */
1614 static void
1615 smb_ads_get_default_comp_container_dn(smb_ads_handle_t *ah, char *buf,
1616     size_t buflen)
1617 {
1618 	(void) snprintf(buf, buflen, "cn=%s,%s", SMB_ADS_COMPUTERS_CN,
1619 	    ah->domain_dn);
1620 }
1621 
1622 /*
1623  * smb_ads_get_default_comp_dn
1624  *
1625  * Build the distinguished name for this system.
1626  */
1627 static void
1628 smb_ads_get_default_comp_dn(smb_ads_handle_t *ah, char *buf, size_t buflen)
1629 {
1630 	char nbname[NETBIOS_NAME_SZ];
1631 	char container_dn[SMB_ADS_DN_MAX];
1632 
1633 	(void) smb_getnetbiosname(nbname, sizeof (nbname));
1634 	smb_ads_get_default_comp_container_dn(ah, container_dn, SMB_ADS_DN_MAX);
1635 	(void) snprintf(buf, buflen, "cn=%s,%s", nbname, container_dn);
1636 }
1637 
1638 /*
1639  * smb_ads_add_computer
1640  *
1641  * Returns 0 upon success. Otherwise, returns -1.
1642  */
1643 static int
1644 smb_ads_add_computer(smb_ads_handle_t *ah, int dclevel, char *dn)
1645 {
1646 	return (smb_ads_computer_op(ah, LDAP_MOD_ADD, dclevel, dn));
1647 }
1648 
1649 /*
1650  * smb_ads_modify_computer
1651  *
1652  * Returns 0 upon success. Otherwise, returns -1.
1653  */
1654 static int
1655 smb_ads_modify_computer(smb_ads_handle_t *ah, int dclevel, char *dn)
1656 {
1657 	return (smb_ads_computer_op(ah, LDAP_MOD_REPLACE, dclevel, dn));
1658 }
1659 
1660 /*
1661  * smb_ads_get_dc_level
1662  *
1663  * Returns the functional level of the DC upon success.
1664  * Otherwise, -1 is returned.
1665  */
1666 static int
1667 smb_ads_get_dc_level(smb_ads_handle_t *ah)
1668 {
1669 	LDAPMessage *res, *entry;
1670 	char *attr[2];
1671 	char **vals;
1672 	int rc = -1;
1673 
1674 	res = NULL;
1675 	attr[0] = SMB_ADS_ATTR_DCLEVEL;
1676 	attr[1] = NULL;
1677 	if (ldap_search_s(ah->ld, "", LDAP_SCOPE_BASE, NULL, attr,
1678 	    0, &res) != LDAP_SUCCESS) {
1679 		(void) ldap_msgfree(res);
1680 		return (-1);
1681 	}
1682 
1683 	/* no match for the specified attribute is found */
1684 	if (ldap_count_entries(ah->ld, res) == 0) {
1685 		(void) ldap_msgfree(res);
1686 		return (-1);
1687 	}
1688 
1689 	entry = ldap_first_entry(ah->ld, res);
1690 	if (entry) {
1691 		if ((vals = ldap_get_values(ah->ld, entry,
1692 		    SMB_ADS_ATTR_DCLEVEL)) == NULL) {
1693 			/*
1694 			 * Observed the values aren't populated
1695 			 * by the Windows 2000 server.
1696 			 */
1697 			(void) ldap_msgfree(res);
1698 			return (SMB_ADS_DCLEVEL_W2K);
1699 		}
1700 
1701 		if (vals[0] != NULL)
1702 			rc = atoi(vals[0]);
1703 
1704 		ldap_value_free(vals);
1705 	}
1706 
1707 	(void) ldap_msgfree(res);
1708 	return (rc);
1709 }
1710 
1711 static int
1712 smb_ads_getfqhostname(smb_ads_handle_t *ah, char *fqhost, int len)
1713 {
1714 	if (smb_gethostname(fqhost, len, 0) != 0)
1715 		return (-1);
1716 
1717 	(void) snprintf(fqhost, len, "%s.%s", fqhost,
1718 	    ah->domain);
1719 
1720 	return (0);
1721 }
1722 
1723 static int
1724 smb_ads_computer_op(smb_ads_handle_t *ah, int op, int dclevel, char *dn)
1725 {
1726 	LDAPMod *attrs[SMB_ADS_COMPUTER_NUM_ATTR];
1727 	char *sam_val[2], *usr_val[2];
1728 	char *spn_set[SMBKRB5_SPN_IDX_MAX + 1], *ctl_val[2], *fqh_val[2];
1729 	char *encrypt_val[2];
1730 	int j = -1;
1731 	int ret, usrctl_flags = 0;
1732 	char sam_acct[SMB_SAMACCT_MAXLEN];
1733 	char fqhost[MAXHOSTNAMELEN];
1734 	char *user_principal;
1735 	char usrctl_buf[16];
1736 	char encrypt_buf[16];
1737 	int max;
1738 
1739 	if (smb_getsamaccount(sam_acct, sizeof (sam_acct)) != 0)
1740 		return (-1);
1741 
1742 	if (smb_ads_getfqhostname(ah, fqhost, MAXHOSTNAMELEN))
1743 		return (-1);
1744 
1745 	if (smb_ads_get_spnset(fqhost, spn_set) != 0)
1746 		return (-1);
1747 
1748 	user_principal = smb_krb5_get_upn(spn_set[SMBKRB5_SPN_IDX_HOST],
1749 	    ah->domain);
1750 
1751 	if (user_principal == NULL) {
1752 		smb_ads_free_spnset(spn_set);
1753 		return (-1);
1754 	}
1755 
1756 	max = (SMB_ADS_COMPUTER_NUM_ATTR - ((op != LDAP_MOD_ADD) ? 1 : 0))
1757 	    - (dclevel >= SMB_ADS_DCLEVEL_W2K8 ?  0 : 1);
1758 
1759 	if (smb_ads_alloc_attr(attrs, max) != 0) {
1760 		free(user_principal);
1761 		smb_ads_free_spnset(spn_set);
1762 		return (-1);
1763 	}
1764 
1765 	/* objectClass attribute is not modifiable. */
1766 	if (op == LDAP_MOD_ADD) {
1767 		attrs[++j]->mod_op = op;
1768 		attrs[j]->mod_type = "objectClass";
1769 		attrs[j]->mod_values = smb_ads_computer_objcls;
1770 	}
1771 
1772 	attrs[++j]->mod_op = op;
1773 	attrs[j]->mod_type = SMB_ADS_ATTR_SAMACCT;
1774 	sam_val[0] = sam_acct;
1775 	sam_val[1] = 0;
1776 	attrs[j]->mod_values = sam_val;
1777 
1778 	attrs[++j]->mod_op = op;
1779 	attrs[j]->mod_type = SMB_ADS_ATTR_UPN;
1780 	usr_val[0] = user_principal;
1781 	usr_val[1] = 0;
1782 	attrs[j]->mod_values = usr_val;
1783 
1784 	attrs[++j]->mod_op = op;
1785 	attrs[j]->mod_type = SMB_ADS_ATTR_SPN;
1786 	attrs[j]->mod_values = spn_set;
1787 
1788 	attrs[++j]->mod_op = op;
1789 	attrs[j]->mod_type = SMB_ADS_ATTR_CTL;
1790 	usrctl_flags |= (SMB_ADS_USER_ACCT_CTL_WKSTATION_TRUST_ACCT |
1791 	    SMB_ADS_USER_ACCT_CTL_PASSWD_NOTREQD |
1792 	    SMB_ADS_USER_ACCT_CTL_ACCOUNTDISABLE);
1793 	(void) snprintf(usrctl_buf, sizeof (usrctl_buf), "%d", usrctl_flags);
1794 	ctl_val[0] = usrctl_buf;
1795 	ctl_val[1] = 0;
1796 	attrs[j]->mod_values = ctl_val;
1797 
1798 	attrs[++j]->mod_op = op;
1799 	attrs[j]->mod_type = SMB_ADS_ATTR_DNSHOST;
1800 	fqh_val[0] = fqhost;
1801 	fqh_val[1] = 0;
1802 	attrs[j]->mod_values = fqh_val;
1803 
1804 	/* enctypes support starting in Windows Server 2008 */
1805 	if (dclevel > SMB_ADS_DCLEVEL_W2K3) {
1806 		attrs[++j]->mod_op = op;
1807 		attrs[j]->mod_type = SMB_ADS_ATTR_ENCTYPES;
1808 		(void) snprintf(encrypt_buf, sizeof (encrypt_buf), "%d",
1809 		    SMB_ADS_ENC_AES256 + SMB_ADS_ENC_AES128 + SMB_ADS_ENC_RC4 +
1810 		    SMB_ADS_ENC_DES_MD5 + SMB_ADS_ENC_DES_CRC);
1811 		encrypt_val[0] = encrypt_buf;
1812 		encrypt_val[1] = 0;
1813 		attrs[j]->mod_values = encrypt_val;
1814 	}
1815 
1816 	switch (op) {
1817 	case LDAP_MOD_ADD:
1818 		if ((ret = ldap_add_s(ah->ld, dn, attrs)) != LDAP_SUCCESS) {
1819 			syslog(LOG_NOTICE, "ldap_add: %s",
1820 			    ldap_err2string(ret));
1821 			ret = -1;
1822 		}
1823 		break;
1824 
1825 	case LDAP_MOD_REPLACE:
1826 		if ((ret = ldap_modify_s(ah->ld, dn, attrs)) != LDAP_SUCCESS) {
1827 			syslog(LOG_NOTICE, "ldap_modify: %s",
1828 			    ldap_err2string(ret));
1829 			ret = -1;
1830 		}
1831 		break;
1832 
1833 	default:
1834 		ret = -1;
1835 
1836 	}
1837 
1838 	smb_ads_free_attr(attrs);
1839 	free(user_principal);
1840 	smb_ads_free_spnset(spn_set);
1841 
1842 	return (ret);
1843 }
1844 
1845 /*
1846  * Delete an ADS computer account.
1847  */
1848 static void
1849 smb_ads_del_computer(smb_ads_handle_t *ah, char *dn)
1850 {
1851 	int rc;
1852 
1853 	if ((rc = ldap_delete_s(ah->ld, dn)) != LDAP_SUCCESS)
1854 		smb_tracef("ldap_delete: %s", ldap_err2string(rc));
1855 }
1856 
1857 /*
1858  * Gets the value of the given attribute.
1859  */
1860 static smb_ads_qstat_t
1861 smb_ads_getattr(LDAP *ld, LDAPMessage *entry, smb_ads_avpair_t *avpair)
1862 {
1863 	char **vals;
1864 	smb_ads_qstat_t rc = SMB_ADS_STAT_FOUND;
1865 
1866 	assert(avpair);
1867 	avpair->avp_val = NULL;
1868 	vals = ldap_get_values(ld, entry, avpair->avp_attr);
1869 	if (!vals)
1870 		return (SMB_ADS_STAT_NOT_FOUND);
1871 
1872 	if (!vals[0]) {
1873 		ldap_value_free(vals);
1874 		return (SMB_ADS_STAT_NOT_FOUND);
1875 	}
1876 
1877 	avpair->avp_val = strdup(vals[0]);
1878 	if (!avpair->avp_val)
1879 		rc = SMB_ADS_STAT_ERR;
1880 
1881 	ldap_value_free(vals);
1882 	return (rc);
1883 }
1884 
1885 /*
1886  * Process query's result.
1887  */
1888 static smb_ads_qstat_t
1889 smb_ads_get_qstat(smb_ads_handle_t *ah, LDAPMessage *res,
1890     smb_ads_avpair_t *avpair)
1891 {
1892 	char fqhost[MAXHOSTNAMELEN];
1893 	smb_ads_avpair_t dnshost_avp;
1894 	smb_ads_qstat_t rc = SMB_ADS_STAT_FOUND;
1895 	LDAPMessage *entry;
1896 
1897 	if (smb_ads_getfqhostname(ah, fqhost, MAXHOSTNAMELEN))
1898 		return (SMB_ADS_STAT_ERR);
1899 
1900 	if (ldap_count_entries(ah->ld, res) == 0)
1901 		return (SMB_ADS_STAT_NOT_FOUND);
1902 
1903 	if ((entry = ldap_first_entry(ah->ld, res)) == NULL)
1904 		return (SMB_ADS_STAT_ERR);
1905 
1906 	dnshost_avp.avp_attr = SMB_ADS_ATTR_DNSHOST;
1907 	rc = smb_ads_getattr(ah->ld, entry, &dnshost_avp);
1908 
1909 	switch (rc) {
1910 	case SMB_ADS_STAT_FOUND:
1911 		/*
1912 		 * Returns SMB_ADS_STAT_DUP to avoid overwriting
1913 		 * the computer account of another system whose
1914 		 * NetBIOS name collides with that of the current
1915 		 * system.
1916 		 */
1917 		if (strcasecmp(dnshost_avp.avp_val, fqhost))
1918 			rc = SMB_ADS_STAT_DUP;
1919 
1920 		free(dnshost_avp.avp_val);
1921 		break;
1922 
1923 	case SMB_ADS_STAT_NOT_FOUND:
1924 		/*
1925 		 * Pre-created computer account doesn't have
1926 		 * the dNSHostname attribute. It's been observed
1927 		 * that the dNSHostname attribute is only set after
1928 		 * a successful domain join.
1929 		 * Returns SMB_ADS_STAT_FOUND as the account is
1930 		 * pre-created for the current system.
1931 		 */
1932 		rc = SMB_ADS_STAT_FOUND;
1933 		break;
1934 
1935 	default:
1936 		break;
1937 	}
1938 
1939 	if (rc != SMB_ADS_STAT_FOUND)
1940 		return (rc);
1941 
1942 	if (avpair)
1943 		rc = smb_ads_getattr(ah->ld, entry, avpair);
1944 
1945 	return (rc);
1946 
1947 }
1948 
1949 /*
1950  * smb_ads_lookup_computer_n_attr
1951  *
1952  * If avpair is NULL, checks the status of the specified computer account.
1953  * Otherwise, looks up the value of the specified computer account's attribute.
1954  * If found, the value field of the avpair will be allocated and set. The
1955  * caller should free the allocated buffer.
1956  *
1957  * Return:
1958  *  SMB_ADS_STAT_FOUND  - if both the computer and the specified attribute is
1959  *                        found.
1960  *  SMB_ADS_STAT_NOT_FOUND - if either the computer or the specified attribute
1961  *                           is not found.
1962  *  SMB_ADS_STAT_DUP - if the computer account is already used by other systems
1963  *                     in the AD. This could happen if the hostname of multiple
1964  *                     systems resolved to the same NetBIOS name.
1965  *  SMB_ADS_STAT_ERR - any failure.
1966  */
1967 static smb_ads_qstat_t
1968 smb_ads_lookup_computer_n_attr(smb_ads_handle_t *ah, smb_ads_avpair_t *avpair,
1969     int scope, char *dn)
1970 {
1971 	char *attrs[3], filter[SMB_ADS_MAXBUFLEN];
1972 	LDAPMessage *res;
1973 	char sam_acct[SMB_SAMACCT_MAXLEN], sam_acct2[SMB_SAMACCT_MAXLEN];
1974 	smb_ads_qstat_t rc;
1975 
1976 	if (smb_getsamaccount(sam_acct, sizeof (sam_acct)) != 0)
1977 		return (SMB_ADS_STAT_ERR);
1978 
1979 	res = NULL;
1980 	attrs[0] = SMB_ADS_ATTR_DNSHOST;
1981 	attrs[1] = NULL;
1982 	attrs[2] = NULL;
1983 
1984 	if (avpair) {
1985 		if (!avpair->avp_attr)
1986 			return (SMB_ADS_STAT_ERR);
1987 
1988 		attrs[1] = avpair->avp_attr;
1989 	}
1990 
1991 	if (smb_ads_escape_search_filter_chars(sam_acct, sam_acct2) != 0)
1992 		return (SMB_ADS_STAT_ERR);
1993 
1994 	(void) snprintf(filter, sizeof (filter),
1995 	    "(&(objectClass=computer)(%s=%s))", SMB_ADS_ATTR_SAMACCT,
1996 	    sam_acct2);
1997 
1998 	if (ldap_search_s(ah->ld, dn, scope, filter, attrs, 0,
1999 	    &res) != LDAP_SUCCESS) {
2000 		(void) ldap_msgfree(res);
2001 		return (SMB_ADS_STAT_NOT_FOUND);
2002 	}
2003 
2004 	rc = smb_ads_get_qstat(ah, res, avpair);
2005 	/* free the search results */
2006 	(void) ldap_msgfree(res);
2007 	return (rc);
2008 }
2009 
2010 /*
2011  * smb_ads_find_computer
2012  *
2013  * Starts by searching for the system's AD computer object in the default
2014  * container (i.e. cn=Computers).  If not found, searches the entire directory.
2015  * If found, 'dn' will be set to the distinguished name of the system's AD
2016  * computer object.
2017  */
2018 static smb_ads_qstat_t
2019 smb_ads_find_computer(smb_ads_handle_t *ah, char *dn)
2020 {
2021 	smb_ads_qstat_t stat;
2022 	smb_ads_avpair_t avpair;
2023 
2024 	avpair.avp_attr = SMB_ADS_ATTR_DN;
2025 	smb_ads_get_default_comp_container_dn(ah, dn, SMB_ADS_DN_MAX);
2026 	stat = smb_ads_lookup_computer_n_attr(ah, &avpair, LDAP_SCOPE_ONELEVEL,
2027 	    dn);
2028 
2029 	if (stat == SMB_ADS_STAT_NOT_FOUND) {
2030 		(void) strlcpy(dn, ah->domain_dn, SMB_ADS_DN_MAX);
2031 		stat = smb_ads_lookup_computer_n_attr(ah, &avpair,
2032 		    LDAP_SCOPE_SUBTREE, dn);
2033 	}
2034 
2035 	if (stat == SMB_ADS_STAT_FOUND) {
2036 		(void) strlcpy(dn, avpair.avp_val, SMB_ADS_DN_MAX);
2037 		free(avpair.avp_val);
2038 	}
2039 
2040 	return (stat);
2041 }
2042 
2043 /*
2044  * smb_ads_update_computer_cntrl_attr
2045  *
2046  * Modify the user account control attribute of an existing computer
2047  * object on AD.
2048  *
2049  * Returns LDAP error code.
2050  */
2051 static int
2052 smb_ads_update_computer_cntrl_attr(smb_ads_handle_t *ah, int flags, char *dn)
2053 {
2054 	LDAPMod *attrs[2];
2055 	char *ctl_val[2];
2056 	int ret = 0;
2057 	char usrctl_buf[16];
2058 
2059 	if (smb_ads_alloc_attr(attrs, sizeof (attrs) / sizeof (LDAPMod *)) != 0)
2060 		return (LDAP_NO_MEMORY);
2061 
2062 	attrs[0]->mod_op = LDAP_MOD_REPLACE;
2063 	attrs[0]->mod_type = SMB_ADS_ATTR_CTL;
2064 
2065 	(void) snprintf(usrctl_buf, sizeof (usrctl_buf), "%d", flags);
2066 	ctl_val[0] = usrctl_buf;
2067 	ctl_val[1] = 0;
2068 	attrs[0]->mod_values = ctl_val;
2069 	if ((ret = ldap_modify_s(ah->ld, dn, attrs)) != LDAP_SUCCESS) {
2070 		syslog(LOG_NOTICE, "ldap_modify: %s", ldap_err2string(ret));
2071 	}
2072 
2073 	smb_ads_free_attr(attrs);
2074 	return (ret);
2075 }
2076 
2077 /*
2078  * smb_ads_lookup_computer_attr_kvno
2079  *
2080  * Lookup the value of the Kerberos version number attribute of the computer
2081  * account.
2082  */
2083 static krb5_kvno
2084 smb_ads_lookup_computer_attr_kvno(smb_ads_handle_t *ah, char *dn)
2085 {
2086 	smb_ads_avpair_t avpair;
2087 	int kvno = 1;
2088 
2089 	avpair.avp_attr = SMB_ADS_ATTR_KVNO;
2090 	if (smb_ads_lookup_computer_n_attr(ah, &avpair,
2091 	    LDAP_SCOPE_BASE, dn) == SMB_ADS_STAT_FOUND) {
2092 		kvno = atoi(avpair.avp_val);
2093 		free(avpair.avp_val);
2094 	}
2095 
2096 	return (kvno);
2097 }
2098 
2099 /*
2100  * smb_ads_gen_machine_passwd
2101  *
2102  * Returned a null-terminated machine password generated randomly
2103  * from [0-9a-zA-Z] character set. In order to pass the password
2104  * quality check (three character classes), an uppercase letter is
2105  * used as the first character of the machine password.
2106  */
2107 static void
2108 smb_ads_gen_machine_passwd(char *machine_passwd, int bufsz)
2109 {
2110 	char *data = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJK"
2111 	    "LMNOPQRSTUVWXYZ";
2112 	int datalen = strlen(data);
2113 	int i, data_idx;
2114 
2115 	assert(machine_passwd);
2116 	assert(bufsz > 0);
2117 
2118 	/*
2119 	 * The decimal value of upper case 'A' is 65. Randomly pick
2120 	 * an upper-case letter from the ascii table.
2121 	 */
2122 	machine_passwd[0] = (random() % 26) + 65;
2123 	for (i = 1; i < bufsz - 1; i++) {
2124 		data_idx = random() % datalen;
2125 		machine_passwd[i] = data[data_idx];
2126 	}
2127 
2128 	machine_passwd[bufsz - 1] = 0;
2129 }
2130 
2131 /*
2132  * smb_ads_join
2133  *
2134  * Besides the NT-4 style domain join (using MS-RPC), CIFS server also
2135  * provides the domain join using Kerberos Authentication, Keberos
2136  * Change & Set password, and LDAP protocols. Basically, AD join
2137  * operation would require the following tickets to be acquired for the
2138  * the user account that is provided for the domain join.
2139  *
2140  * 1) a Keberos TGT ticket,
2141  * 2) a ldap service ticket, and
2142  * 3) kadmin/changpw service ticket
2143  *
2144  * The ADS client first sends a ldap search request to find out whether
2145  * or not the workstation trust account already exists in the Active Directory.
2146  * The existing computer object for this workstation will be removed and
2147  * a new one will be added. The machine account password is randomly
2148  * generated and set for the newly created computer object using KPASSWD
2149  * protocol (See RFC 3244). Once the password is set, our ADS client
2150  * finalizes the machine account by modifying the user acount control
2151  * attribute of the computer object. Kerberos keys derived from the machine
2152  * account password will be stored locally in /etc/krb5/krb5.keytab file.
2153  * That would be needed while acquiring Kerberos TGT ticket for the host
2154  * principal after the domain join operation.
2155  */
2156 smb_adjoin_status_t
2157 smb_ads_join(char *domain, char *user, char *usr_passwd, char *machine_passwd,
2158     int len)
2159 {
2160 	smb_ads_handle_t *ah = NULL;
2161 	krb5_context ctx = NULL;
2162 	krb5_principal krb5princs[SMBKRB5_SPN_IDX_MAX];
2163 	krb5_kvno kvno;
2164 	boolean_t des_only, delete = B_TRUE;
2165 	smb_adjoin_status_t rc = SMB_ADJOIN_SUCCESS;
2166 	boolean_t new_acct;
2167 	int dclevel, num, usrctl_flags = 0;
2168 	smb_ads_qstat_t qstat;
2169 	char dn[SMB_ADS_DN_MAX];
2170 	char *tmpfile;
2171 
2172 	/*
2173 	 * Call library functions that can be used to get
2174 	 * the list of encryption algorithms available on the system.
2175 	 * (similar to what 'encrypt -l' CLI does). For now,
2176 	 * unless someone has modified the configuration of the
2177 	 * cryptographic framework (very unlikely), the following is the
2178 	 * list of algorithms available on any system running Nevada
2179 	 * by default.
2180 	 */
2181 	krb5_enctype w2k8enctypes[] = {ENCTYPE_AES256_CTS_HMAC_SHA1_96,
2182 	    ENCTYPE_AES128_CTS_HMAC_SHA1_96, ENCTYPE_ARCFOUR_HMAC,
2183 	    ENCTYPE_DES_CBC_CRC, ENCTYPE_DES_CBC_MD5,
2184 	};
2185 
2186 	krb5_enctype pre_w2k8enctypes[] = {ENCTYPE_ARCFOUR_HMAC,
2187 	    ENCTYPE_DES_CBC_CRC, ENCTYPE_DES_CBC_MD5,
2188 	};
2189 
2190 	krb5_enctype *encptr;
2191 
2192 	if ((ah = smb_ads_open_main(domain, user, usr_passwd)) == NULL) {
2193 		smb_ccache_remove(SMB_CCACHE_PATH);
2194 		return (SMB_ADJOIN_ERR_GET_HANDLE);
2195 	}
2196 
2197 	smb_ads_gen_machine_passwd(machine_passwd, len);
2198 
2199 	if ((dclevel = smb_ads_get_dc_level(ah)) == -1) {
2200 		smb_ads_close(ah);
2201 		smb_ccache_remove(SMB_CCACHE_PATH);
2202 		return (SMB_ADJOIN_ERR_GET_DCLEVEL);
2203 	}
2204 
2205 	qstat = smb_ads_find_computer(ah, dn);
2206 	switch (qstat) {
2207 	case SMB_ADS_STAT_FOUND:
2208 		new_acct = B_FALSE;
2209 		if (smb_ads_modify_computer(ah, dclevel, dn) != 0) {
2210 			smb_ads_close(ah);
2211 			smb_ccache_remove(SMB_CCACHE_PATH);
2212 			return (SMB_ADJOIN_ERR_MOD_TRUST_ACCT);
2213 		}
2214 		break;
2215 
2216 	case SMB_ADS_STAT_NOT_FOUND:
2217 		new_acct = B_TRUE;
2218 		smb_ads_get_default_comp_dn(ah, dn, SMB_ADS_DN_MAX);
2219 		if (smb_ads_add_computer(ah, dclevel, dn) != 0) {
2220 			smb_ads_close(ah);
2221 			smb_ccache_remove(SMB_CCACHE_PATH);
2222 			return (SMB_ADJOIN_ERR_ADD_TRUST_ACCT);
2223 		}
2224 		break;
2225 
2226 	default:
2227 		if (qstat == SMB_ADS_STAT_DUP)
2228 			rc = SMB_ADJOIN_ERR_DUP_TRUST_ACCT;
2229 		else
2230 			rc = SMB_ADJOIN_ERR_TRUST_ACCT;
2231 		smb_ads_close(ah);
2232 		smb_ccache_remove(SMB_CCACHE_PATH);
2233 		return (rc);
2234 	}
2235 
2236 	des_only = B_FALSE;
2237 
2238 	if (smb_krb5_ctx_init(&ctx) != 0) {
2239 		rc = SMB_ADJOIN_ERR_INIT_KRB_CTX;
2240 		goto adjoin_cleanup;
2241 	}
2242 
2243 	if (smb_krb5_get_principals(ah->domain, ctx, krb5princs) != 0) {
2244 		rc = SMB_ADJOIN_ERR_GET_SPNS;
2245 		goto adjoin_cleanup;
2246 	}
2247 
2248 	if (smb_krb5_setpwd(ctx, krb5princs[SMBKRB5_SPN_IDX_HOST],
2249 	    machine_passwd) != 0) {
2250 		rc = SMB_ADJOIN_ERR_KSETPWD;
2251 		goto adjoin_cleanup;
2252 	}
2253 
2254 	kvno = smb_ads_lookup_computer_attr_kvno(ah, dn);
2255 
2256 	/*
2257 	 * Only members of Domain Admins and Enterprise Admins can set
2258 	 * the TRUSTED_FOR_DELEGATION userAccountControl flag.
2259 	 */
2260 	if (smb_ads_update_computer_cntrl_attr(ah,
2261 	    SMB_ADS_USER_ACCT_CTL_WKSTATION_TRUST_ACCT |
2262 	    SMB_ADS_USER_ACCT_CTL_TRUSTED_FOR_DELEGATION, dn)
2263 	    == LDAP_INSUFFICIENT_ACCESS) {
2264 		usrctl_flags |= (SMB_ADS_USER_ACCT_CTL_WKSTATION_TRUST_ACCT |
2265 		    SMB_ADS_USER_ACCT_CTL_DONT_EXPIRE_PASSWD);
2266 
2267 		syslog(LOG_NOTICE, "Unable to set the "
2268 		    "TRUSTED_FOR_DELEGATION userAccountControl flag on "
2269 		    "the machine account in Active Directory.  Please refer "
2270 		    "to the Troubleshooting guide for more information.");
2271 
2272 	} else {
2273 		usrctl_flags |= (SMB_ADS_USER_ACCT_CTL_WKSTATION_TRUST_ACCT |
2274 		    SMB_ADS_USER_ACCT_CTL_TRUSTED_FOR_DELEGATION |
2275 		    SMB_ADS_USER_ACCT_CTL_DONT_EXPIRE_PASSWD);
2276 	}
2277 
2278 	if (des_only)
2279 		usrctl_flags |= SMB_ADS_USER_ACCT_CTL_USE_DES_KEY_ONLY;
2280 
2281 	if (smb_ads_update_computer_cntrl_attr(ah, usrctl_flags, dn)
2282 	    != 0) {
2283 		rc = SMB_ADJOIN_ERR_UPDATE_CNTRL_ATTR;
2284 		goto adjoin_cleanup;
2285 	}
2286 
2287 	if (dclevel >= SMB_ADS_DCLEVEL_W2K8) {
2288 		num = sizeof (w2k8enctypes) / sizeof (krb5_enctype);
2289 		encptr = w2k8enctypes;
2290 	} else {
2291 		num = sizeof (pre_w2k8enctypes) / sizeof (krb5_enctype);
2292 		encptr = pre_w2k8enctypes;
2293 	}
2294 
2295 	tmpfile = mktemp(SMBNS_KRB5_KEYTAB_TMP);
2296 	if (tmpfile == NULL)
2297 		tmpfile = SMBNS_KRB5_KEYTAB_TMP;
2298 
2299 	if (smb_krb5_add_keytab_entries(ctx, krb5princs, tmpfile,
2300 	    kvno, machine_passwd, encptr, num) != 0) {
2301 		rc = SMB_ADJOIN_ERR_WRITE_KEYTAB;
2302 		goto adjoin_cleanup;
2303 	}
2304 
2305 	delete = B_FALSE;
2306 adjoin_cleanup:
2307 	if (new_acct && delete)
2308 		smb_ads_del_computer(ah, dn);
2309 
2310 	if (rc != SMB_ADJOIN_ERR_INIT_KRB_CTX) {
2311 		if (rc != SMB_ADJOIN_ERR_GET_SPNS)
2312 			smb_krb5_free_principals(ctx, krb5princs,
2313 			    SMBKRB5_SPN_IDX_MAX);
2314 		smb_krb5_ctx_fini(ctx);
2315 	}
2316 
2317 	/* commit keytab file */
2318 	if (rc == SMB_ADJOIN_SUCCESS) {
2319 		if (rename(tmpfile, SMBNS_KRB5_KEYTAB) != 0) {
2320 			(void) unlink(tmpfile);
2321 			rc = SMB_ADJOIN_ERR_COMMIT_KEYTAB;
2322 		} else {
2323 			/* Set IDMAP config */
2324 			if (smb_config_set_idmap_domain(ah->domain) != 0) {
2325 				rc = SMB_ADJOIN_ERR_IDMAP_SET_DOMAIN;
2326 			} else {
2327 
2328 				/* Refresh IDMAP service */
2329 				if (smb_config_refresh_idmap() != 0)
2330 					rc = SMB_ADJOIN_ERR_IDMAP_REFRESH;
2331 			}
2332 		}
2333 	} else {
2334 		(void) unlink(tmpfile);
2335 	}
2336 
2337 	smb_ads_close(ah);
2338 	smb_ccache_remove(SMB_CCACHE_PATH);
2339 	return (rc);
2340 }
2341 
2342 /*
2343  * smb_ads_join_errmsg
2344  *
2345  * Display error message for the specific adjoin error code.
2346  */
2347 void
2348 smb_ads_join_errmsg(smb_adjoin_status_t status)
2349 {
2350 	int i;
2351 	struct xlate_table {
2352 		smb_adjoin_status_t status;
2353 		char *msg;
2354 	} adjoin_table[] = {
2355 		{ SMB_ADJOIN_ERR_GET_HANDLE, "Failed to connect to an "
2356 		    "Active Directory server." },
2357 		{ SMB_ADJOIN_ERR_GET_DCLEVEL, "Unknown functional level of "
2358 		    "the domain controller. The rootDSE attribute named "
2359 		    "\"domainControllerFunctionality\" is missing from the "
2360 		    "Active Directory." },
2361 		{ SMB_ADJOIN_ERR_ADD_TRUST_ACCT, "Failed to create the "
2362 		    "workstation trust account." },
2363 		{ SMB_ADJOIN_ERR_MOD_TRUST_ACCT, "Failed to modify the "
2364 		    "workstation trust account." },
2365 		{ SMB_ADJOIN_ERR_DUP_TRUST_ACCT, "Failed to create the "
2366 		    "workstation trust account because its name is already "
2367 		    "in use." },
2368 		{ SMB_ADJOIN_ERR_TRUST_ACCT, "Error in querying the "
2369 		    "workstation trust account" },
2370 		{ SMB_ADJOIN_ERR_INIT_KRB_CTX, "Failed to initialize Kerberos "
2371 		    "context." },
2372 		{ SMB_ADJOIN_ERR_GET_SPNS, "Failed to get Kerberos "
2373 		    "principals." },
2374 		{ SMB_ADJOIN_ERR_KSETPWD, "Failed to set machine password." },
2375 		{ SMB_ADJOIN_ERR_UPDATE_CNTRL_ATTR,  "Failed to modify "
2376 		    "userAccountControl attribute of the workstation trust "
2377 		    "account." },
2378 		{ SMB_ADJOIN_ERR_WRITE_KEYTAB, "Error in writing to local "
2379 		    "keytab file (i.e /etc/krb5/krb5.keytab)." },
2380 		{ SMB_ADJOIN_ERR_IDMAP_SET_DOMAIN, "Failed to update idmap "
2381 		    "configuration." },
2382 		{ SMB_ADJOIN_ERR_IDMAP_REFRESH, "Failed to refresh idmap "
2383 		    "service." },
2384 		{ SMB_ADJOIN_ERR_COMMIT_KEYTAB, "Failed to commit changes to "
2385 		    "local keytab file (i.e. /etc/krb5/krb5.keytab)." }
2386 	};
2387 
2388 	for (i = 0; i < sizeof (adjoin_table) / sizeof (adjoin_table[0]); i++) {
2389 		if (adjoin_table[i].status == status)
2390 			syslog(LOG_NOTICE, "%s", adjoin_table[i].msg);
2391 	}
2392 }
2393 
2394 /*
2395  * smb_ads_match_pdc
2396  *
2397  * Returns B_TRUE if the given host's IP address matches the preferred DC's
2398  * IP address. Otherwise, returns B_FALSE.
2399  */
2400 static boolean_t
2401 smb_ads_match_pdc(smb_ads_host_info_t *host)
2402 {
2403 	boolean_t match = B_FALSE;
2404 
2405 	if (!host)
2406 		return (match);
2407 
2408 	(void) mutex_lock(&smb_ads_cfg.c_mtx);
2409 	if (smb_inet_equal(&host->ipaddr, &smb_ads_cfg.c_pdc))
2410 		match = B_TRUE;
2411 	(void) mutex_unlock(&smb_ads_cfg.c_mtx);
2412 
2413 	return (match);
2414 }
2415 
2416 /*
2417  * smb_ads_select_dcfromsubnet
2418  *
2419  * This method walks the list of DCs and returns the first DC record that
2420  * responds to ldap ping and is in the same subnet as the host.
2421  *
2422  * Returns a pointer to the found DC record.
2423  * Returns NULL, on error or if no DC record is found.
2424  */
2425 static smb_ads_host_info_t *
2426 smb_ads_select_dcfromsubnet(smb_ads_host_list_t *hlist)
2427 {
2428 	smb_ads_host_info_t *hentry;
2429 	smb_nic_t *lnic;
2430 	smb_niciter_t ni;
2431 	size_t cnt;
2432 	int i;
2433 
2434 	if (smb_nic_getfirst(&ni) != 0)
2435 		return (NULL);
2436 	do {
2437 		lnic = &ni.ni_nic;
2438 		cnt = hlist->ah_cnt;
2439 
2440 		for (i = 0; i < cnt; i++) {
2441 			hentry = &hlist->ah_list[i];
2442 			if ((hentry->ipaddr.a_family == AF_INET) &&
2443 			    (lnic->nic_ip.a_family == AF_INET)) {
2444 				if ((hentry->ipaddr.a_ipv4 &
2445 				    lnic->nic_mask) ==
2446 				    (lnic->nic_ip.a_ipv4 &
2447 				    lnic->nic_mask))
2448 					if (smb_ads_ldap_ping(hentry) == 0)
2449 						return (hentry);
2450 			}
2451 		}
2452 	} while (smb_nic_getnext(&ni) == 0);
2453 
2454 	return (NULL);
2455 }
2456 
2457 /*
2458  * smb_ads_select_dcfromlist
2459  *
2460  * This method walks the list of DCs and returns the first DC that
2461  * responds to ldap ping.
2462  *
2463  * Returns a pointer to the found DC record.
2464  * Returns NULL if no DC record is found.
2465  */
2466 static smb_ads_host_info_t *
2467 smb_ads_select_dcfromlist(smb_ads_host_list_t *hlist)
2468 {
2469 	smb_ads_host_info_t *hentry;
2470 	size_t cnt;
2471 	int i;
2472 
2473 	cnt = hlist->ah_cnt;
2474 	for (i = 0; i < cnt; i++) {
2475 		hentry = &hlist->ah_list[i];
2476 		if (smb_ads_ldap_ping(hentry) == 0)
2477 			return (hentry);
2478 	}
2479 
2480 	return (NULL);
2481 }
2482 
2483 /*
2484  * smb_ads_dc_compare
2485  *
2486  * Comparision function for sorting host entries (SRV records of DC) via qsort.
2487  * RFC 2052/2782 are taken as reference, while implementing this algorithm.
2488  *
2489  * Domain Controllers(DCs) with lowest priority in their SRV DNS records
2490  * are selected first. If they have equal priorities, then DC with highest
2491  * weight in its SRV DNS record is selected. If the priority and weight are
2492  * both equal, then the DC at the top of the list is selected.
2493  */
2494 static int
2495 smb_ads_dc_compare(const void *p, const void *q)
2496 {
2497 	smb_ads_host_info_t *h1 = (smb_ads_host_info_t *)p;
2498 	smb_ads_host_info_t *h2 = (smb_ads_host_info_t *)q;
2499 
2500 	if (h1->priority < h2->priority)
2501 		return (-1);
2502 	if (h1->priority > h2->priority)
2503 		return (1);
2504 
2505 	/* Priorities are equal */
2506 	if (h1->weight < h2->weight)
2507 		return (1);
2508 	if (h1->weight > h2->weight)
2509 		return (-1);
2510 
2511 	return (0);
2512 }
2513 
2514 /*
2515  * smb_ads_select_dc
2516  *
2517  * The list of ADS hosts returned by ADS lookup, is sorted by lowest priority
2518  * and highest weight. On this sorted list, following additional rules are
2519  * applied, to select a DC.
2520  *
2521  *  - If there is a DC in the same subnet, then return the DC,
2522  *    if it responds to ldap ping.
2523  *  - Else, return first DC that responds to ldap ping.
2524  *
2525  * A reference to the host entry from input host list is returned.
2526  *
2527  * Returns NULL on error.
2528  */
2529 static smb_ads_host_info_t *
2530 smb_ads_select_dc(smb_ads_host_list_t *hlist)
2531 {
2532 	smb_ads_host_info_t *hentry = NULL;
2533 
2534 	if (hlist->ah_cnt == 0)
2535 		return (NULL);
2536 
2537 	if (hlist->ah_cnt == 1) {
2538 		hentry = hlist->ah_list;
2539 		if (smb_ads_ldap_ping(hentry) == 0)
2540 			return (hentry);
2541 	}
2542 
2543 	/* Sort the list by priority and weight */
2544 	qsort(hlist->ah_list, hlist->ah_cnt,
2545 	    sizeof (smb_ads_host_info_t), smb_ads_dc_compare);
2546 
2547 	if ((hentry = smb_ads_select_dcfromsubnet(hlist)) != NULL)
2548 		return (hentry);
2549 
2550 	if ((hentry = smb_ads_select_dcfromlist(hlist)) != NULL)
2551 		return (hentry);
2552 
2553 	return (NULL);
2554 }
2555 
2556 /*
2557  * smb_ads_lookup_msdcs
2558  *
2559  * If server argument is set, try to locate the specified DC.
2560  * If it is set to empty string, locate any DCs in the specified domain.
2561  * Returns the discovered DC via buf.
2562  *
2563  * fqdn	  - fully-qualified domain name
2564  * server - fully-qualifed hostname of a DC
2565  * buf    - the hostname of the discovered DC
2566  */
2567 boolean_t
2568 smb_ads_lookup_msdcs(char *fqdn, char *server, char *buf, uint32_t buflen)
2569 {
2570 	smb_ads_host_info_t *hinfo = NULL;
2571 	char *p;
2572 	char *sought_host;
2573 	char ipstr[INET6_ADDRSTRLEN];
2574 
2575 	if (!fqdn || !buf)
2576 		return (B_FALSE);
2577 
2578 	ipstr[0] = '\0';
2579 	*buf = '\0';
2580 	sought_host = (*server == 0 ? NULL : server);
2581 	if ((hinfo = smb_ads_find_host(fqdn, sought_host)) == NULL)
2582 		return (B_FALSE);
2583 
2584 	(void) smb_inet_ntop(&hinfo->ipaddr, ipstr,
2585 	    SMB_IPSTRLEN(hinfo->ipaddr.a_family));
2586 	smb_tracef("msdcsLookupADS: %s [%s]", hinfo->name, ipstr);
2587 
2588 	(void) strlcpy(buf, hinfo->name, buflen);
2589 	/*
2590 	 * Remove the domain extension
2591 	 */
2592 	if ((p = strchr(buf, '.')) != 0)
2593 		*p = '\0';
2594 
2595 	free(hinfo);
2596 	return (B_TRUE);
2597 }
2598