/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
 * Copyright 2022 Tintri by DDN, Inc. All rights reserved.
 * Copyright 2021 RackTop Systems, Inc.
 */

#include <sys/param.h>
#include <ldap.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <sys/time.h>
#include <netdb.h>
#include <pthread.h>
#include <unistd.h>
#include <arpa/nameser.h>
#include <resolv.h>
#include <sys/synch.h>
#include <string.h>
#include <strings.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <assert.h>
#include <sasl/sasl.h>
#include <note.h>
#include <errno.h>
#include <cryptoutil.h>
#include <ads/dsgetdc.h>

#include <smbsrv/libsmbns.h>
#include <smbns_dyndns.h>
#include <smbns_krb.h>

#define	SMB_ADS_AF_UNKNOWN(x)	(((x)->ipaddr.a_family != AF_INET) && \
	((x)->ipaddr.a_family != AF_INET6))

#define	SMB_ADS_MAXBUFLEN 100
#define	SMB_ADS_DN_MAX	300
#define	SMB_ADS_MAXMSGLEN 512
#define	SMB_ADS_COMPUTERS_CN "Computers"
#define	SMB_ADS_COMPUTER_NUM_ATTR 8
#define	SMB_ADS_SHARE_NUM_ATTR 3
#define	SMB_ADS_SITE_MAX MAXHOSTNAMELEN

#define	SMB_ADS_MSDCS_SRV_DC_RR		"_ldap._tcp.dc._msdcs"
#define	SMB_ADS_MSDCS_SRV_SITE_RR	"_ldap._tcp.%s._sites.dc._msdcs"

/*
 * domainControllerFunctionality
 *
 * This rootDSE attribute indicates the functional level of the DC.
 */
#define	SMB_ADS_ATTR_DCLEVEL	"domainControllerFunctionality"
#define	SMB_ADS_DCLEVEL_W2K	0
#define	SMB_ADS_DCLEVEL_W2K3	2
#define	SMB_ADS_DCLEVEL_W2K8	3
#define	SMB_ADS_DCLEVEL_W2K8_R2 4

/*
 * msDs-supportedEncryptionTypes (Windows Server 2008 only)
 *
 * This attribute defines the encryption types supported by the system.
 * Encryption Types:
 *  - DES cbc mode with CRC-32
 *  - DES cbc mode with RSA-MD5
 *  - ArcFour with HMAC/md5
 *  - AES-128
 *  - AES-256
 */
#define	SMB_ADS_ATTR_ENCTYPES	"msDs-supportedEncryptionTypes"
#define	SMB_ADS_ENC_DES_CRC	1
#define	SMB_ADS_ENC_DES_MD5	2
#define	SMB_ADS_ENC_RC4		4
#define	SMB_ADS_ENC_AES128	8
#define	SMB_ADS_ENC_AES256	16

static krb5_enctype w2k8enctypes[] = {
    ENCTYPE_AES256_CTS_HMAC_SHA1_96,
    ENCTYPE_AES128_CTS_HMAC_SHA1_96,
    ENCTYPE_ARCFOUR_HMAC,
    ENCTYPE_DES_CBC_CRC,
    ENCTYPE_DES_CBC_MD5,
};

static krb5_enctype pre_w2k8enctypes[] = {
    ENCTYPE_ARCFOUR_HMAC,
    ENCTYPE_DES_CBC_CRC,
    ENCTYPE_DES_CBC_MD5,
};

#define	SMB_ADS_ATTR_SAMACCT	"sAMAccountName"
#define	SMB_ADS_ATTR_UPN	"userPrincipalName"
#define	SMB_ADS_ATTR_SPN	"servicePrincipalName"
#define	SMB_ADS_ATTR_CTL	"userAccountControl"
#define	SMB_ADS_ATTR_DNSHOST	"dNSHostName"
#define	SMB_ADS_ATTR_KVNO	"msDS-KeyVersionNumber"
#define	SMB_ADS_ATTR_DN		"distinguishedName"

/*
 * UserAccountControl flags: manipulate user account properties.
 *
 * The hexadecimal value of the following property flags are based on MSDN
 * article # 305144.
 */
#define	SMB_ADS_USER_ACCT_CTL_SCRIPT				0x00000001
#define	SMB_ADS_USER_ACCT_CTL_ACCOUNTDISABLE			0x00000002
#define	SMB_ADS_USER_ACCT_CTL_HOMEDIR_REQUIRED			0x00000008
#define	SMB_ADS_USER_ACCT_CTL_LOCKOUT				0x00000010
#define	SMB_ADS_USER_ACCT_CTL_PASSWD_NOTREQD			0x00000020
#define	SMB_ADS_USER_ACCT_CTL_PASSWD_CANT_CHANGE		0x00000040
#define	SMB_ADS_USER_ACCT_CTL_ENCRYPTED_TEXT_PWD_ALLOWED	0x00000080
#define	SMB_ADS_USER_ACCT_CTL_TMP_DUP_ACCT			0x00000100
#define	SMB_ADS_USER_ACCT_CTL_NORMAL_ACCT			0x00000200
#define	SMB_ADS_USER_ACCT_CTL_INTERDOMAIN_TRUST_ACCT		0x00000800
#define	SMB_ADS_USER_ACCT_CTL_WKSTATION_TRUST_ACCT		0x00001000
#define	SMB_ADS_USER_ACCT_CTL_SRV_TRUST_ACCT			0x00002000
#define	SMB_ADS_USER_ACCT_CTL_DONT_EXPIRE_PASSWD		0x00010000
#define	SMB_ADS_USER_ACCT_CTL_MNS_LOGON_ACCT			0x00020000
#define	SMB_ADS_USER_ACCT_CTL_SMARTCARD_REQUIRED		0x00040000
#define	SMB_ADS_USER_ACCT_CTL_TRUSTED_FOR_DELEGATION		0x00080000
#define	SMB_ADS_USER_ACCT_CTL_NOT_DELEGATED			0x00100000
#define	SMB_ADS_USER_ACCT_CTL_USE_DES_KEY_ONLY			0x00200000
#define	SMB_ADS_USER_ACCT_CTL_DONT_REQ_PREAUTH			0x00400000
#define	SMB_ADS_USER_ACCT_CTL_PASSWD_EXPIRED			0x00800000
#define	SMB_ADS_USER_ACCT_CTL_TRUSTED_TO_AUTH_FOR_DELEGATION	0x01000000

/*
 * Length of "dc=" prefix.
 */
#define	SMB_ADS_DN_PREFIX_LEN	3

static char *smb_ads_computer_objcls[] = {
	"top", "person", "organizationalPerson",
	"user", "computer", NULL
};

static char *smb_ads_share_objcls[] = {
	"top", "leaf", "connectionPoint", "volume", NULL
};

/* Cached ADS server to communicate with */
static smb_ads_host_info_t *smb_ads_cached_host_info = NULL;
static mutex_t smb_ads_cached_host_mtx;

/*
 * SMB ADS config cache is maintained to facilitate the detection of
 * changes in configuration that is relevant to AD selection.
 */
typedef struct smb_ads_config {
	char c_site[SMB_ADS_SITE_MAX];
	mutex_t c_mtx;
} smb_ads_config_t;

static smb_ads_config_t smb_ads_cfg;


/* attribute/value pair */
typedef struct smb_ads_avpair {
	char *avp_attr;
	char *avp_val;
} smb_ads_avpair_t;

/* query status */
typedef enum smb_ads_qstat {
	SMB_ADS_STAT_ERR = -2,
	SMB_ADS_STAT_DUP,
	SMB_ADS_STAT_NOT_FOUND,
	SMB_ADS_STAT_FOUND
} smb_ads_qstat_t;

typedef struct smb_ads_host_list {
	int ah_cnt;
	smb_ads_host_info_t *ah_list;
} smb_ads_host_list_t;

static int smb_ads_open_main(smb_ads_handle_t **, char *, char *, char *);
static int smb_ads_add_computer(smb_ads_handle_t *, int, char *);
static int smb_ads_modify_computer(smb_ads_handle_t *, int, char *);
static int smb_ads_computer_op(smb_ads_handle_t *, int, int, char *);
static smb_ads_qstat_t smb_ads_lookup_computer_n_attr(smb_ads_handle_t *,
    smb_ads_avpair_t *, int, char *);
static int smb_ads_update_computer_cntrl_attr(smb_ads_handle_t *, int, char *);
static krb5_kvno smb_ads_lookup_computer_attr_kvno(smb_ads_handle_t *, char *);
static void smb_ads_free_cached_host(void);
static int smb_ads_alloc_attr(LDAPMod **, int);
static void smb_ads_free_attr(LDAPMod **);
static int smb_ads_get_dc_level(smb_ads_handle_t *);
static smb_ads_qstat_t smb_ads_find_computer(smb_ads_handle_t *, char *);
static smb_ads_qstat_t smb_ads_getattr(LDAP *, LDAPMessage *,
    smb_ads_avpair_t *);
static smb_ads_qstat_t smb_ads_get_qstat(smb_ads_handle_t *, LDAPMessage *,
    smb_ads_avpair_t *);
static boolean_t smb_ads_is_same_domain(char *, char *);
static smb_ads_host_info_t *smb_ads_dup_host_info(smb_ads_host_info_t *);
static char *smb_ads_get_sharedn(const char *, const char *, const char *);
static krb5_enctype *smb_ads_get_enctypes(int, int *);

/*
 * smb_ads_init
 *
 * Initializes the ADS config cache.
 */
void
smb_ads_init(void)
{
	(void) mutex_lock(&smb_ads_cfg.c_mtx);
	(void) smb_config_getstr(SMB_CI_ADS_SITE,
	    smb_ads_cfg.c_site, SMB_ADS_SITE_MAX);
	(void) mutex_unlock(&smb_ads_cfg.c_mtx);

	/* Force -lads to load, for dtrace. */
	DsFreeDcInfo(NULL);
}

void
smb_ads_fini(void)
{
	smb_ads_free_cached_host();
}

/*
 * smb_ads_refresh
 *
 * This function will be called when smb/server SMF service is refreshed.
 * (See smbd_join.c)
 *
 * Clearing the smb_ads_cached_host_info would allow the next DC
 * discovery process to pick up an AD based on the new AD configuration.
 */
void
smb_ads_refresh(boolean_t force_rediscovery)
{
	char new_site[SMB_ADS_SITE_MAX];

	(void) smb_config_getstr(SMB_CI_ADS_SITE, new_site, SMB_ADS_SITE_MAX);
	(void) mutex_lock(&smb_ads_cfg.c_mtx);
	(void) strlcpy(smb_ads_cfg.c_site, new_site, SMB_ADS_SITE_MAX);
	(void) mutex_unlock(&smb_ads_cfg.c_mtx);

	smb_ads_free_cached_host();

	if (force_rediscovery) {
		(void) _DsForceRediscovery(NULL, 0);
	}
}


/*
 * smb_ads_build_unc_name
 *
 * Construct the UNC name of the share object in the format of
 * \\hostname.domain\shareUNC
 *
 * Returns 0 on success, -1 on error.
 */
int
smb_ads_build_unc_name(char *unc_name, int maxlen,
    const char *hostname, const char *shareUNC)
{
	char my_domain[MAXHOSTNAMELEN];

	if (smb_getfqdomainname(my_domain, sizeof (my_domain)) != 0)
		return (-1);

	(void) snprintf(unc_name, maxlen, "\\\\%s.%s\\%s",
	    hostname, my_domain, shareUNC);
	return (0);
}

/*
 * The cached ADS host is no longer valid if one of the following criteria
 * is satisfied:
 *
 * 1) not in the specified domain
 * 2) not the sought host (if specified)
 * 3) not reachable
 *
 * The caller is responsible for acquiring the smb_ads_cached_host_mtx lock
 * prior to calling this function.
 *
 * Return B_TRUE if the cache host is still valid. Otherwise, return B_FALSE.
 */
static boolean_t
smb_ads_validate_cache_host(char *domain)
{
	if (!smb_ads_cached_host_info)
		return (B_FALSE);

	if (!smb_ads_is_same_domain(smb_ads_cached_host_info->name, domain))
		return (B_FALSE);

	return (B_TRUE);
}

/*
 * smb_ads_match_hosts_same_domain
 *
 * Returns true, if the cached ADS host is in the same domain as the
 * current (given) domain.
 */
static boolean_t
smb_ads_is_same_domain(char *cached_host_name, char *current_domain)
{
	char *cached_host_domain;

	if ((cached_host_name == NULL) || (current_domain == NULL))
		return (B_FALSE);

	cached_host_domain = strchr(cached_host_name, '.');
	if (cached_host_domain == NULL)
		return (B_FALSE);

	++cached_host_domain;
	if (smb_strcasecmp(cached_host_domain, current_domain, 0))
		return (B_FALSE);

	return (B_TRUE);
}

/*
 * smb_ads_dup_host_info
 *
 * Duplicates the passed smb_ads_host_info_t structure.
 * Caller must free memory allocated by this method.
 *
 * Returns a reference to the duplicated smb_ads_host_info_t structure.
 * Returns NULL on error.
 */
static smb_ads_host_info_t *
smb_ads_dup_host_info(smb_ads_host_info_t *ads_host)
{
	smb_ads_host_info_t *dup_host;

	if (ads_host == NULL)
		return (NULL);

	dup_host = malloc(sizeof (smb_ads_host_info_t));

	if (dup_host != NULL)
		bcopy(ads_host, dup_host, sizeof (smb_ads_host_info_t));

	return (dup_host);
}

/*
 * smb_ads_find_host
 *
 * Finds an ADS host in a given domain.
 *
 * If the cached host is valid, it will be used. Otherwise, a DC will
 * be selected based on the following criteria:
 *
 * 1) pdc (aka preferred DC) configuration
 * 2) AD site configuration - the scope of the DNS lookup will be
 * restricted to the specified site.
 * 3) DC on the same subnet
 * 4) DC with the lowest priority/highest weight
 *
 * The above items are listed in decreasing preference order. The selected
 * DC must be online.
 *
 * If this function is called during domain join, the specified kpasswd server
 * takes precedence over preferred DC, AD site, and so on.
 *
 * Parameters:
 *   domain: fully-qualified domain name.
 *
 * Returns:
 *   A copy of the cached host info is returned. The caller is responsible
 *   for deallocating the memory returned by this function.
 */
/*ARGSUSED*/
smb_ads_host_info_t *
smb_ads_find_host(char *domain)
{
	smb_ads_host_info_t *host = NULL;
	DOMAIN_CONTROLLER_INFO *dci = NULL;
	struct sockaddr_storage *ss;
	uint32_t flags = DS_DS_FLAG;
	uint32_t status;
	int tries;

	(void) mutex_lock(&smb_ads_cached_host_mtx);
	if (smb_ads_validate_cache_host(domain)) {
		host = smb_ads_dup_host_info(smb_ads_cached_host_info);
		(void) mutex_unlock(&smb_ads_cached_host_mtx);
		return (host);
	}

	(void) mutex_unlock(&smb_ads_cached_host_mtx);
	smb_ads_free_cached_host();

	/*
	 * The _real_ DC Locator is over in idmapd.
	 * Door call over there to get it.
	 */
	tries = 15;
again:
	status = _DsGetDcName(
	    NULL,	/* ComputerName */
	    domain,
	    NULL,	/* DomainGuid */
	    NULL,	/* SiteName */
	    flags,
	    &dci);
	switch (status) {
	case 0:
		break;
	/*
	 * We can see these errors when joining a domain, if we race
	 * asking idmap for the DC before it knows the new domain.
	 */
	case NT_STATUS_NO_SUCH_DOMAIN:	/* Specified domain unknown */
	case NT_STATUS_INVALID_SERVER_STATE:	/*  not in domain mode. */
		if (--tries > 0) {
			(void) sleep(1);
			goto again;
		}
		/* FALLTHROUGH */
	case NT_STATUS_DOMAIN_CONTROLLER_NOT_FOUND:
	case NT_STATUS_CANT_WAIT:	/* timeout over in idmap */
	default:
		return (NULL);
	}

	host = calloc(1, sizeof (*host));
	if (host == NULL)
		goto out;

	(void) strlcpy(host->name, dci->DomainControllerName, MAXHOSTNAMELEN);
	ss = (void *)dci->_sockaddr;
	switch (ss->ss_family) {
	case AF_INET: {
		struct sockaddr_in *sin = (void *)ss;
		host->port = ntohs(sin->sin_port);
		host->ipaddr.a_family = AF_INET;
		(void) memcpy(&host->ipaddr.a_ipv4, &sin->sin_addr,
		    sizeof (in_addr_t));
		break;
	}
	case AF_INET6: {
		struct sockaddr_in6 *sin6 = (void *)ss;
		host->port = ntohs(sin6->sin6_port);
		host->ipaddr.a_family = AF_INET6;
		(void) memcpy(&host->ipaddr.a_ipv6, &sin6->sin6_addr,
		    sizeof (in6_addr_t));
		break;
	}
	default:
		syslog(LOG_ERR, "no addr for DC %s",
		    dci->DomainControllerName);
		free(host);
		host = NULL;
		goto out;
	}

	host->flags = dci->Flags;

	(void) mutex_lock(&smb_ads_cached_host_mtx);
	if (!smb_ads_cached_host_info)
		smb_ads_cached_host_info = smb_ads_dup_host_info(host);
	(void) mutex_unlock(&smb_ads_cached_host_mtx);

out:
	DsFreeDcInfo(dci);
	return (host);
}

/*
 * Return the number of dots in a string.
 */
static int
smb_ads_count_dots(const char *s)
{
	int ndots = 0;

	while (*s) {
		if (*s++ == '.')
			ndots++;
	}

	return (ndots);
}

/*
 * Convert a domain name in dot notation to distinguished name format,
 * for example: sun.com -> dc=sun,dc=com.
 *
 * Returns a pointer to an allocated buffer containing the distinguished
 * name.
 */
static char *
smb_ads_convert_domain(const char *domain_name)
{
	const char *s;
	char *dn_name;
	char buf[2];
	int ndots;
	int len;

	if (domain_name == NULL || *domain_name == 0)
		return (NULL);

	ndots = smb_ads_count_dots(domain_name);
	++ndots;
	len = strlen(domain_name) + (ndots * SMB_ADS_DN_PREFIX_LEN) + 1;

	if ((dn_name = malloc(len)) == NULL)
		return (NULL);

	bzero(dn_name, len);
	(void) strlcpy(dn_name, "dc=", len);

	buf[1] = '\0';
	s = domain_name;

	while (*s) {
		if (*s == '.') {
			(void) strlcat(dn_name, ",dc=", len);
		} else {
			buf[0] = *s;
			(void) strlcat(dn_name, buf, len);
		}
		++s;
	}

	return (dn_name);
}

/*
 * smb_ads_free_cached_host
 *
 * Free the memory use by the global smb_ads_cached_host_info & set it to NULL.
 */
static void
smb_ads_free_cached_host(void)
{
	(void) mutex_lock(&smb_ads_cached_host_mtx);
	if (smb_ads_cached_host_info) {
		free(smb_ads_cached_host_info);
		smb_ads_cached_host_info = NULL;
	}
	(void) mutex_unlock(&smb_ads_cached_host_mtx);
}

/*
 * smb_ads_open
 * Open a LDAP connection to an ADS server if the system is in domain mode.
 * Acquire both Kerberos TGT and LDAP service tickets for the host principal.
 *
 * This function should only be called after the system is successfully joined
 * to a domain.
 */
smb_ads_handle_t *
smb_ads_open(void)
{
	char domain[MAXHOSTNAMELEN];
	smb_ads_handle_t *h;
	smb_ads_status_t err;

	if (smb_config_get_secmode() != SMB_SECMODE_DOMAIN)
		return (NULL);

	if (smb_getfqdomainname(domain, MAXHOSTNAMELEN) != 0)
		return (NULL);

	err = smb_ads_open_main(&h, domain, NULL, NULL);
	if (err != 0) {
		smb_ads_log_errmsg(err);
		return (NULL);
	}

	return (h);
}

static int
smb_ads_saslcallback(LDAP *ld, unsigned flags, void *defaults, void *prompts)
{
	NOTE(ARGUNUSED(ld, defaults));
	sasl_interact_t *interact;

	if (prompts == NULL || flags != LDAP_SASL_INTERACTIVE)
		return (LDAP_PARAM_ERROR);

	/* There should be no extra arguemnts for SASL/GSSAPI authentication */
	for (interact = prompts; interact->id != SASL_CB_LIST_END;
	    interact++) {
		interact->result = NULL;
		interact->len = 0;
	}
	return (LDAP_SUCCESS);
}

/*
 * smb_ads_open_main
 * Open a LDAP connection to an ADS server.
 * If ADS is enabled and the administrative username, password, and
 * ADS domain are defined then query DNS to find an ADS server if this is the
 * very first call to this routine.  After an ADS server is found then this
 * server will be used everytime this routine is called until the system is
 * rebooted or the ADS server becomes unavailable then an ADS server will
 * be queried again.  After the connection is made then an ADS handle
 * is created to be returned.
 *
 * After the LDAP connection, the LDAP version will be set to 3 using
 * ldap_set_option().
 *
 * The LDAP connection is bound before the ADS handle is returned.
 * Parameters:
 *   domain - fully-qualified domain name
 *   user   - the user account for whom the Kerberos TGT ticket and ADS
 *            service tickets are acquired.
 *   password - password of the specified user
 *
 * Returns:
 *   NULL              : can't connect to ADS server or other errors
 *   smb_ads_handle_t* : handle to ADS server
 */
static int
smb_ads_open_main(smb_ads_handle_t **hp, char *domain, char *user,
    char *password)
{
	smb_ads_handle_t *ah;
	LDAP *ld;
	int version = 3;
	smb_ads_host_info_t *ads_host = NULL;
	int err, rc;

	*hp = NULL;

	if (user != NULL) {
		err = smb_kinit(domain, user, password);
		if (err != 0) {
			syslog(LOG_ERR, "smbns: kinit failed");
			return (err);
		}
		user = NULL;
		password = NULL;
	}

	ads_host = smb_ads_find_host(domain);
	if (ads_host == NULL)
		return (SMB_ADS_CANT_LOCATE_DC);

	ah = (smb_ads_handle_t *)malloc(sizeof (smb_ads_handle_t));
	if (ah == NULL) {
		free(ads_host);
		return (ENOMEM);
	}

	(void) memset(ah, 0, sizeof (smb_ads_handle_t));

	if ((ld = ldap_init(ads_host->name, ads_host->port)) == NULL) {
		syslog(LOG_ERR, "smbns: ldap_init failed");
		smb_ads_free_cached_host();
		free(ah);
		free(ads_host);
		return (SMB_ADS_LDAP_INIT);
	}

	if (ldap_set_option(ld, LDAP_OPT_PROTOCOL_VERSION, &version)
	    != LDAP_SUCCESS) {
		smb_ads_free_cached_host();
		free(ah);
		free(ads_host);
		(void) ldap_unbind(ld);
		return (SMB_ADS_LDAP_SETOPT);
	}

	(void) ldap_set_option(ld, LDAP_OPT_REFERRALS, LDAP_OPT_OFF);
	ah->ld = ld;
	ah->domain = strdup(domain);

	if (ah->domain == NULL) {
		smb_ads_close(ah);
		free(ads_host);
		return (SMB_ADS_LDAP_SETOPT);
	}

	/*
	 * ah->domain is often used for generating service principal name.
	 * Convert it to lower case for RFC 4120 section 6.2.1 conformance.
	 */
	(void) smb_strlwr(ah->domain);
	ah->domain_dn = smb_ads_convert_domain(domain);
	if (ah->domain_dn == NULL) {
		smb_ads_close(ah);
		free(ads_host);
		return (SMB_ADS_LDAP_SET_DOM);
	}

	ah->hostname = strdup(ads_host->name);
	if (ah->hostname == NULL) {
		smb_ads_close(ah);
		free(ads_host);
		return (ENOMEM);
	}
	(void) mutex_lock(&smb_ads_cfg.c_mtx);
	if (*smb_ads_cfg.c_site != '\0') {
		if ((ah->site = strdup(smb_ads_cfg.c_site)) == NULL) {
			smb_ads_close(ah);
			(void) mutex_unlock(&smb_ads_cfg.c_mtx);
			free(ads_host);
			return (ENOMEM);
		}
	} else {
		ah->site = NULL;
	}
	(void) mutex_unlock(&smb_ads_cfg.c_mtx);

	syslog(LOG_DEBUG, "smbns: smb_ads_open_main");
	syslog(LOG_DEBUG, "smbns: domain: %s", ah->domain);
	syslog(LOG_DEBUG, "smbns: domain_dn: %s", ah->domain_dn);
	syslog(LOG_DEBUG, "smbns: ip_addr: %s", ah->ip_addr);
	syslog(LOG_DEBUG, "smbns: hostname: %s", ah->hostname);
	syslog(LOG_DEBUG, "smbns: site: %s",
	    (ah->site != NULL) ? ah->site : "");

	rc = ldap_sasl_interactive_bind_s(ah->ld, "", "GSSAPI", NULL, NULL,
	    LDAP_SASL_INTERACTIVE, &smb_ads_saslcallback, NULL);
	if (rc != LDAP_SUCCESS) {
		syslog(LOG_ERR, "smbns: ldap_sasl_..._bind_s failed (%s)",
		    ldap_err2string(rc));
		smb_ads_close(ah);
		free(ads_host);
		return (SMB_ADS_LDAP_SASL_BIND);
	}
	syslog(LOG_DEBUG, "smbns: ldap_sasl_..._bind_s success");

	free(ads_host);
	*hp = ah;

	return (SMB_ADS_SUCCESS);
}

/*
 * smb_ads_close
 * Close connection to ADS server and free memory allocated for ADS handle.
 * LDAP unbind is called here.
 * Parameters:
 *   ah: handle to ADS server
 * Returns:
 *   void
 */
void
smb_ads_close(smb_ads_handle_t *ah)
{
	if (ah == NULL)
		return;
	/* close and free connection resources */
	if (ah->ld)
		(void) ldap_unbind(ah->ld);

	free(ah->domain);
	free(ah->domain_dn);
	free(ah->hostname);
	free(ah->site);
	free(ah);
}

/*
 * smb_ads_alloc_attr
 *
 * Since the attrs is a null-terminated array, all elements
 * in the array (except the last one) will point to allocated
 * memory.
 */
static int
smb_ads_alloc_attr(LDAPMod *attrs[], int num)
{
	int i;

	bzero(attrs, num * sizeof (LDAPMod *));
	for (i = 0; i < (num - 1); i++) {
		attrs[i] = (LDAPMod *)malloc(sizeof (LDAPMod));
		if (attrs[i] == NULL) {
			smb_ads_free_attr(attrs);
			return (-1);
		}
	}

	return (0);
}

/*
 * smb_ads_free_attr
 * Free memory allocated when publishing a share.
 * Parameters:
 *   attrs: an array of LDAPMod pointers
 * Returns:
 *   None
 */
static void
smb_ads_free_attr(LDAPMod *attrs[])
{
	int i;
	for (i = 0; attrs[i]; i++) {
		free(attrs[i]);
	}
}

/*
 * Returns share DN in an allocated buffer.  The format of the DN is
 * cn=<sharename>,<container RDNs>,<domain DN>
 *
 * If the domain DN is not included in the container parameter,
 * then it will be appended to create the share DN.
 *
 * The caller must free the allocated buffer.
 */
static char *
smb_ads_get_sharedn(const char *sharename, const char *container,
    const char *domain_dn)
{
	char *share_dn;
	int rc, offset, container_len, domain_len;
	boolean_t append_domain = B_TRUE;

	container_len = strlen(container);
	domain_len = strlen(domain_dn);

	if (container_len >= domain_len) {

		/* offset to last domain_len characters */
		offset = container_len - domain_len;

		if (smb_strcasecmp(container + offset,
		    domain_dn, domain_len) == 0)
			append_domain = B_FALSE;
	}

	if (append_domain)
		rc = asprintf(&share_dn, "cn=%s,%s,%s", sharename,
		    container, domain_dn);
	else
		rc = asprintf(&share_dn, "cn=%s,%s", sharename,
		    container);

	return ((rc == -1) ? NULL : share_dn);
}

/*
 * smb_ads_add_share
 * Call by smb_ads_publish_share to create share object in ADS.
 * This routine specifies the attributes of an ADS LDAP share object. The first
 * attribute and values define the type of ADS object, the share object.  The
 * second attribute and value define the UNC of the share data for the share
 * object. The LDAP synchronous add command is used to add the object into ADS.
 * The container location to add the object needs to specified.
 * Parameters:
 *   ah          : handle to ADS server
 *   adsShareName: name of share object to be created in ADS
 *   shareUNC    : share name on NetForce
 *   adsContainer: location in ADS to create share object
 *
 * Returns:
 *   -1          : error
 *    0          : success
 */
int
smb_ads_add_share(smb_ads_handle_t *ah, const char *adsShareName,
    const char *unc_name, const char *adsContainer)
{
	LDAPMod *attrs[SMB_ADS_SHARE_NUM_ATTR];
	int j = 0;
	char *share_dn;
	int ret;
	char *unc_names[] = {(char *)unc_name, NULL};

	if ((share_dn = smb_ads_get_sharedn(adsShareName, adsContainer,
	    ah->domain_dn)) == NULL)
		return (-1);

	if (smb_ads_alloc_attr(attrs, SMB_ADS_SHARE_NUM_ATTR) != 0) {
		free(share_dn);
		return (-1);
	}

	attrs[j]->mod_op = LDAP_MOD_ADD;
	attrs[j]->mod_type = "objectClass";
	attrs[j]->mod_values = smb_ads_share_objcls;

	attrs[++j]->mod_op = LDAP_MOD_ADD;
	attrs[j]->mod_type = "uNCName";
	attrs[j]->mod_values = unc_names;

	if ((ret = ldap_add_s(ah->ld, share_dn, attrs)) != LDAP_SUCCESS) {
		if (ret == LDAP_NO_SUCH_OBJECT) {
			syslog(LOG_ERR, "Failed to publish share %s in" \
			    " AD.  Container does not exist: %s.\n",
			    adsShareName, share_dn);

		} else {
			syslog(LOG_ERR, "Failed to publish share %s in" \
			    " AD: %s (%s).\n", adsShareName, share_dn,
			    ldap_err2string(ret));
		}
		smb_ads_free_attr(attrs);
		free(share_dn);
		return (ret);
	}
	free(share_dn);
	smb_ads_free_attr(attrs);

	return (0);
}

/*
 * smb_ads_del_share
 * Call by smb_ads_remove_share to remove share object from ADS.  The container
 * location to remove the object needs to specified.  The LDAP synchronous
 * delete command is used.
 * Parameters:
 *   ah          : handle to ADS server
 *   adsShareName: name of share object in ADS to be removed
 *   adsContainer: location of share object in ADS
 * Returns:
 *   -1          : error
 *    0          : success
 */
static int
smb_ads_del_share(smb_ads_handle_t *ah, const char *adsShareName,
    const char *adsContainer)
{
	char *share_dn;
	int ret;

	if ((share_dn = smb_ads_get_sharedn(adsShareName, adsContainer,
	    ah->domain_dn)) == NULL)
		return (-1);

	if ((ret = ldap_delete_s(ah->ld, share_dn)) != LDAP_SUCCESS) {
		smb_tracef("ldap_delete: %s", ldap_err2string(ret));
		free(share_dn);
		return (-1);
	}
	free(share_dn);

	return (0);
}


/*
 * smb_ads_escape_search_filter_chars
 *
 * This routine will escape the special characters found in a string
 * that will later be passed to the ldap search filter.
 *
 * RFC 1960 - A String Representation of LDAP Search Filters
 * 3.  String Search Filter Definition
 * If a value must contain one of the characters '*' OR '(' OR ')',
 * these characters
 * should be escaped by preceding them with the backslash '\' character.
 *
 * RFC 2252 - LDAP Attribute Syntax Definitions
 * a backslash quoting mechanism is used to escape
 * the following separator symbol character (such as "'", "$" or "#") if
 * it should occur in that string.
 */
static int
smb_ads_escape_search_filter_chars(const char *src, char *dst)
{
	int avail = SMB_ADS_MAXBUFLEN - 1; /* reserve a space for NULL char */

	if (src == NULL || dst == NULL)
		return (-1);

	while (*src) {
		if (!avail) {
			*dst = 0;
			return (-1);
		}

		switch (*src) {
		case '\\':
		case '\'':
		case '$':
		case '#':
		case '*':
		case '(':
		case ')':
			*dst++ = '\\';
			avail--;
			/* fall through */

		default:
			*dst++ = *src++;
			avail--;
		}
	}

	*dst = 0;

	return (0);
}

/*
 * smb_ads_lookup_share
 * The search filter is set to search for a specific share name in the
 * specified ADS container.  The LDSAP synchronous search command is used.
 * Parameters:
 *   ah          : handle to ADS server
 *   adsShareName: name of share object in ADS to be searched
 *   adsContainer: location of share object in ADS
 * Returns:
 *   -1          : error
 *    0          : not found
 *    1          : found
 */
int
smb_ads_lookup_share(smb_ads_handle_t *ah, const char *adsShareName,
    const char *adsContainer, char *unc_name)
{
	char *attrs[4], filter[SMB_ADS_MAXBUFLEN];
	char *share_dn;
	int ret;
	LDAPMessage *res;
	char tmpbuf[SMB_ADS_MAXBUFLEN];

	if (adsShareName == NULL || adsContainer == NULL)
		return (-1);

	if ((share_dn = smb_ads_get_sharedn(adsShareName, adsContainer,
	    ah->domain_dn)) == NULL)
		return (-1);

	res = NULL;
	attrs[0] = "cn";
	attrs[1] = "objectClass";
	attrs[2] = "uNCName";
	attrs[3] = NULL;

	if (smb_ads_escape_search_filter_chars(unc_name, tmpbuf) != 0) {
		free(share_dn);
		return (-1);
	}

	(void) snprintf(filter, sizeof (filter),
	    "(&(objectClass=volume)(uNCName=%s))", tmpbuf);

	if ((ret = ldap_search_s(ah->ld, share_dn,
	    LDAP_SCOPE_BASE, filter, attrs, 0, &res)) != LDAP_SUCCESS) {
		if (ret != LDAP_NO_SUCH_OBJECT)
			smb_tracef("%s: ldap_search: %s", share_dn,
			    ldap_err2string(ret));

		(void) ldap_msgfree(res);
		free(share_dn);
		return (0);
	}

	(void) free(share_dn);

	/* no match is found */
	if (ldap_count_entries(ah->ld, res) == 0) {
		(void) ldap_msgfree(res);
		return (0);
	}

	/* free the search results */
	(void) ldap_msgfree(res);

	return (1);
}

/*
 * smb_ads_publish_share
 * Publish share into ADS.  If a share name already exist in ADS in the same
 * container then the existing share object is removed before adding the new
 * share object.
 * Parameters:
 *   ah          : handle return from smb_ads_open
 *   adsShareName: name of share to be added to ADS directory
 *   shareUNC    : name of share on client, can be NULL to use the same name
 *                 as adsShareName
 *   adsContainer: location for share to be added in ADS directory, ie
 *                   ou=share_folder
 *   uncType     : use UNC_HOSTNAME to use hostname for UNC, use UNC_HOSTADDR
 *                   to use host ip addr for UNC.
 * Returns:
 *   -1          : error
 *    0          : success
 */
int
smb_ads_publish_share(smb_ads_handle_t *ah, const char *adsShareName,
    const char *shareUNC, const char *adsContainer, const char *hostname)
{
	int ret;
	char unc_name[SMB_ADS_MAXBUFLEN];

	if (adsShareName == NULL || adsContainer == NULL)
		return (-1);

	if (shareUNC == 0 || *shareUNC == 0)
		shareUNC = adsShareName;

	if (smb_ads_build_unc_name(unc_name, sizeof (unc_name),
	    hostname, shareUNC) < 0)
		return (-1);

	ret = smb_ads_lookup_share(ah, adsShareName, adsContainer, unc_name);

	switch (ret) {
	case 1:
		(void) smb_ads_del_share(ah, adsShareName, adsContainer);
		ret = smb_ads_add_share(ah, adsShareName, unc_name,
		    adsContainer);
		break;

	case 0:
		ret = smb_ads_add_share(ah, adsShareName, unc_name,
		    adsContainer);
		if (ret == LDAP_ALREADY_EXISTS)
			ret = -1;

		break;

	case -1:
	default:
		/* return with error code */
		ret = -1;
	}

	return (ret);
}

/*
 * smb_ads_remove_share
 * Remove share from ADS.  A search is done first before explicitly removing
 * the share.
 * Parameters:
 *   ah          : handle return from smb_ads_open
 *   adsShareName: name of share to be removed from ADS directory
 *   adsContainer: location for share to be removed from ADS directory, ie
 *                   ou=share_folder
 * Returns:
 *   -1          : error
 *    0          : success
 */
int
smb_ads_remove_share(smb_ads_handle_t *ah, const char *adsShareName,
    const char *shareUNC, const char *adsContainer, const char *hostname)
{
	int ret;
	char unc_name[SMB_ADS_MAXBUFLEN];

	if (adsShareName == NULL || adsContainer == NULL)
		return (-1);
	if (shareUNC == 0 || *shareUNC == 0)
		shareUNC = adsShareName;

	if (smb_ads_build_unc_name(unc_name, sizeof (unc_name),
	    hostname, shareUNC) < 0)
		return (-1);

	ret = smb_ads_lookup_share(ah, adsShareName, adsContainer, unc_name);
	if (ret == 0)
		return (0);
	if (ret == -1)
		return (-1);

	return (smb_ads_del_share(ah, adsShareName, adsContainer));
}

/*
 * smb_ads_get_new_comp_dn
 *
 * Build the distinguished name for a new machine account
 * prepend: cn=SamAccountName, cn=Computers, ...domain_dn...
 */
static void
smb_ads_get_new_comp_dn(smb_ads_handle_t *ah, char *buf, size_t buflen,
    char *container)
{
	char nbname[NETBIOS_NAME_SZ];
	if (container == NULL)
		container = "cn=" SMB_ADS_COMPUTERS_CN;

	(void) smb_getnetbiosname(nbname, sizeof (nbname));
	(void) snprintf(buf, buflen, "cn=%s,%s,%s",
	    nbname, container, ah->domain_dn);
}

/*
 * smb_ads_add_computer
 *
 * Returns 0 upon success. Otherwise, returns -1.
 */
static int
smb_ads_add_computer(smb_ads_handle_t *ah, int dclevel, char *dn)
{
	return (smb_ads_computer_op(ah, LDAP_MOD_ADD, dclevel, dn));
}

/*
 * smb_ads_modify_computer
 *
 * Returns 0 upon success. Otherwise, returns -1.
 */
static int
smb_ads_modify_computer(smb_ads_handle_t *ah, int dclevel, char *dn)
{
	return (smb_ads_computer_op(ah, LDAP_MOD_REPLACE, dclevel, dn));
}

/*
 * smb_ads_get_dc_level
 *
 * Returns the functional level of the DC upon success.
 * Otherwise, -1 is returned.
 */
static int
smb_ads_get_dc_level(smb_ads_handle_t *ah)
{
	LDAPMessage *res, *entry;
	char *attr[2];
	char **vals;
	int rc;

	res = NULL;
	attr[0] = SMB_ADS_ATTR_DCLEVEL;
	attr[1] = NULL;
	rc = ldap_search_s(ah->ld, "", LDAP_SCOPE_BASE, NULL, attr, 0, &res);
	if (rc != LDAP_SUCCESS) {
		syslog(LOG_ERR, "smb_ads_get_dc_level: "
		    "LDAP search,  error %s", ldap_err2string(rc));
		(void) ldap_msgfree(res);
		return (-1);
	}

	/* no match for the specified attribute is found */
	if (ldap_count_entries(ah->ld, res) == 0) {
		(void) ldap_msgfree(res);
		return (-1);
	}

	rc = -1;
	entry = ldap_first_entry(ah->ld, res);
	if (entry) {
		if ((vals = ldap_get_values(ah->ld, entry,
		    SMB_ADS_ATTR_DCLEVEL)) == NULL) {
			/*
			 * Observed the values aren't populated
			 * by the Windows 2000 server.
			 */
			syslog(LOG_DEBUG, "smb_ads_get_dc_level: "
			    "LDAP values missing, assume W2K");
			(void) ldap_msgfree(res);
			return (SMB_ADS_DCLEVEL_W2K);
		}

		if (vals[0] != NULL) {
			rc = atoi(vals[0]);
			syslog(LOG_DEBUG, "smb_ads_get_dc_level: "
			    "LDAP value %d", rc);
		}
		ldap_value_free(vals);
	}

	(void) ldap_msgfree(res);
	return (rc);
}

/*
 * The fully-qualified hostname returned by this function is often used for
 * constructing service principal name.  Return the fully-qualified hostname
 * in lower case for RFC 4120 section 6.2.1 conformance.
 */
static int
smb_ads_getfqhostname(smb_ads_handle_t *ah, char *fqhost, int len)
{
	if (smb_gethostname(fqhost, len, SMB_CASE_LOWER) != 0)
		return (-1);

	(void) strlcat(fqhost, ".", len);
	(void) strlcat(fqhost, ah->domain, len);

	return (0);
}

static int
smb_ads_computer_op(smb_ads_handle_t *ah, int op, int dclevel, char *dn)
{
	LDAPMod *attrs[SMB_ADS_COMPUTER_NUM_ATTR];
	char *sam_val[2];
	char *ctl_val[2], *fqh_val[2];
	char *encrypt_val[2];
	int j = -1;
	int ret, usrctl_flags = 0;
	char sam_acct[SMB_SAMACCT_MAXLEN];
	char fqhost[MAXHOSTNAMELEN];
	char usrctl_buf[16];
	char encrypt_buf[16];
	int max;
	smb_krb5_pn_set_t spn, upn;

	syslog(LOG_DEBUG, "smb_ads_computer_op, op=%s dn=%s",
	    (op == LDAP_MOD_ADD) ? "add" : "replace", dn);

	if (smb_getsamaccount(sam_acct, sizeof (sam_acct)) != 0)
		return (-1);

	if (smb_ads_getfqhostname(ah, fqhost, MAXHOSTNAMELEN))
		return (-1);

	/* The SPN attribute is multi-valued and must be 1 or greater */
	if (smb_krb5_get_pn_set(&spn, SMB_PN_SPN_ATTR, ah->domain) == 0)
		return (-1);

	/* The UPN attribute is single-valued and cannot be zero */
	if (smb_krb5_get_pn_set(&upn, SMB_PN_UPN_ATTR, ah->domain) != 1) {
		smb_krb5_free_pn_set(&spn);
		smb_krb5_free_pn_set(&upn);
		return (-1);
	}

	max = (SMB_ADS_COMPUTER_NUM_ATTR - ((op != LDAP_MOD_ADD) ? 1 : 0))
	    - (dclevel >= SMB_ADS_DCLEVEL_W2K8 ?  0 : 1);

	if (smb_ads_alloc_attr(attrs, max) != 0) {
		smb_krb5_free_pn_set(&spn);
		smb_krb5_free_pn_set(&upn);
		return (-1);
	}

	/* objectClass attribute is not modifiable. */
	if (op == LDAP_MOD_ADD) {
		attrs[++j]->mod_op = op;
		attrs[j]->mod_type = "objectClass";
		attrs[j]->mod_values = smb_ads_computer_objcls;
	}

	attrs[++j]->mod_op = op;
	attrs[j]->mod_type = SMB_ADS_ATTR_SAMACCT;
	sam_val[0] = sam_acct;
	sam_val[1] = 0;
	attrs[j]->mod_values = sam_val;

	attrs[++j]->mod_op = op;
	attrs[j]->mod_type = SMB_ADS_ATTR_UPN;
	attrs[j]->mod_values = upn.s_pns;

	attrs[++j]->mod_op = op;
	attrs[j]->mod_type = SMB_ADS_ATTR_SPN;
	attrs[j]->mod_values =  spn.s_pns;

	attrs[++j]->mod_op = op;
	attrs[j]->mod_type = SMB_ADS_ATTR_CTL;
	usrctl_flags |= (SMB_ADS_USER_ACCT_CTL_WKSTATION_TRUST_ACCT |
	    SMB_ADS_USER_ACCT_CTL_PASSWD_NOTREQD |
	    SMB_ADS_USER_ACCT_CTL_ACCOUNTDISABLE);
	(void) snprintf(usrctl_buf, sizeof (usrctl_buf), "%d", usrctl_flags);
	ctl_val[0] = usrctl_buf;
	ctl_val[1] = 0;
	attrs[j]->mod_values = ctl_val;

	attrs[++j]->mod_op = op;
	attrs[j]->mod_type = SMB_ADS_ATTR_DNSHOST;
	fqh_val[0] = fqhost;
	fqh_val[1] = 0;
	attrs[j]->mod_values = fqh_val;

	/* enctypes support starting in Windows Server 2008 */
	if (dclevel > SMB_ADS_DCLEVEL_W2K3) {
		attrs[++j]->mod_op = op;
		attrs[j]->mod_type = SMB_ADS_ATTR_ENCTYPES;
		(void) snprintf(encrypt_buf, sizeof (encrypt_buf), "%d",
		    SMB_ADS_ENC_AES256 + SMB_ADS_ENC_AES128 + SMB_ADS_ENC_RC4 +
		    SMB_ADS_ENC_DES_MD5 + SMB_ADS_ENC_DES_CRC);
		encrypt_val[0] = encrypt_buf;
		encrypt_val[1] = 0;
		attrs[j]->mod_values = encrypt_val;
	}

	switch (op) {
	case LDAP_MOD_ADD:
		if ((ret = ldap_add_s(ah->ld, dn, attrs)) != LDAP_SUCCESS) {
			syslog(LOG_NOTICE, "ldap_add: %s",
			    ldap_err2string(ret));
			ret = -1;
		}
		break;

	case LDAP_MOD_REPLACE:
		if ((ret = ldap_modify_s(ah->ld, dn, attrs)) != LDAP_SUCCESS) {
			syslog(LOG_NOTICE, "ldap_modify: %s",
			    ldap_err2string(ret));
			ret = -1;
		}
		break;

	default:
		ret = -1;

	}

	smb_ads_free_attr(attrs);
	smb_krb5_free_pn_set(&spn);
	smb_krb5_free_pn_set(&upn);

	return (ret);
}

/*
 * Delete an ADS computer account.
 */
static void
smb_ads_del_computer(smb_ads_handle_t *ah, char *dn)
{
	int rc;

	if ((rc = ldap_delete_s(ah->ld, dn)) != LDAP_SUCCESS)
		smb_tracef("ldap_delete: %s", ldap_err2string(rc));
}

/*
 * Gets the value of the given attribute.
 */
static smb_ads_qstat_t
smb_ads_getattr(LDAP *ld, LDAPMessage *entry, smb_ads_avpair_t *avpair)
{
	char **vals;
	smb_ads_qstat_t rc = SMB_ADS_STAT_FOUND;

	assert(avpair);
	avpair->avp_val = NULL;

	syslog(LOG_DEBUG, "smbns: ads_getattr (%s)", avpair->avp_attr);
	vals = ldap_get_values(ld, entry, avpair->avp_attr);
	if (!vals) {
		syslog(LOG_DEBUG, "smbns: ads_getattr err: no vals");
		return (SMB_ADS_STAT_NOT_FOUND);
	}
	if (!vals[0]) {
		syslog(LOG_DEBUG, "smbns: ads_getattr err: no vals[0]");
		ldap_value_free(vals);
		return (SMB_ADS_STAT_NOT_FOUND);
	}

	avpair->avp_val = strdup(vals[0]);
	if (!avpair->avp_val) {
		syslog(LOG_DEBUG, "smbns: ads_getattr err: no mem");
		rc = SMB_ADS_STAT_ERR;
	} else {
		syslog(LOG_DEBUG, "smbns: ads_getattr (%s) OK, val=%s",
		    avpair->avp_attr, avpair->avp_val);
	}

	ldap_value_free(vals);
	return (rc);
}

/*
 * Process query's result, making sure we have what we need.
 *
 * There's some non-obvious logic here for checking the returned
 * DNS name for the machine account, trying to avoid modifying
 * someone else's machine account.  When we search for a machine
 * account we always ask for the DNS name.  For a pre-created
 * machine account, the DNS name will be not set, and that's OK.
 * If we see a DNS name and it doesn't match our DNS name, we'll
 * assume the account belongs to someone else and return "DUP".
 *
 * Only do the DNS name check for our initial search for the
 * machine account, which has avpair->avp_attr = SMB_ADS_ATTR_DN
 */
static smb_ads_qstat_t
smb_ads_get_qstat(smb_ads_handle_t *ah, LDAPMessage *res,
    smb_ads_avpair_t *avpair)
{
	smb_ads_qstat_t rc = SMB_ADS_STAT_FOUND;
	LDAPMessage *entry;

	if (ldap_count_entries(ah->ld, res) == 0) {
		syslog(LOG_DEBUG, "smbns: find_computer, "
		    "ldap_count_entries zero");
		return (SMB_ADS_STAT_NOT_FOUND);
	}

	if ((entry = ldap_first_entry(ah->ld, res)) == NULL) {
		syslog(LOG_DEBUG, "smbns: find_computer, "
		    "ldap_first_entry error");
		return (SMB_ADS_STAT_ERR);
	}

	/* Have an LDAP entry (found something) */
	syslog(LOG_DEBUG, "smbns: find_computer, have LDAP resp.");

	if (avpair != NULL &&
	    strcmp(avpair->avp_attr, SMB_ADS_ATTR_DN) == 0) {
		char fqhost[MAXHOSTNAMELEN];
		smb_ads_avpair_t dnshost_avp;

		syslog(LOG_DEBUG, "smbns: find_computer, check DNS name");

		if (smb_ads_getfqhostname(ah, fqhost, MAXHOSTNAMELEN))
			return (SMB_ADS_STAT_ERR);

		dnshost_avp.avp_attr = SMB_ADS_ATTR_DNSHOST;
		dnshost_avp.avp_val = NULL;
		rc = smb_ads_getattr(ah->ld, entry, &dnshost_avp);

		/*
		 * Status from finding the DNS name value
		 */
		switch (rc) {
		case SMB_ADS_STAT_FOUND:
			/*
			 * Found a DNS name.  If it doesn't match ours,
			 * returns SMB_ADS_STAT_DUP to avoid overwriting
			 * the computer account of another system whose
			 * NetBIOS name collides with that of the current
			 * system.
			 */
			if (strcasecmp(dnshost_avp.avp_val, fqhost)) {
				syslog(LOG_DEBUG, "smbns: find_computer, "
				    "duplicate name (%s)",
				    dnshost_avp.avp_val);
				rc = SMB_ADS_STAT_DUP;
			}
			free(dnshost_avp.avp_val);
			break;

		case SMB_ADS_STAT_NOT_FOUND:
			/*
			 * No dNSHostname attribute, so probably a
			 * pre-created computer account.  Use it.
			 *
			 * Returns SMB_ADS_STAT_FOUND for the status
			 * of finding the machine account.
			 */
			rc = SMB_ADS_STAT_FOUND;
			break;

		default:
			break;
		}

		if (rc != SMB_ADS_STAT_FOUND)
			return (rc);
	}

	if (avpair) {
		syslog(LOG_DEBUG, "smbns: find_computer, check %s",
		    avpair->avp_attr);
		rc = smb_ads_getattr(ah->ld, entry, avpair);
	}

	return (rc);
}

/*
 * smb_ads_lookup_computer_n_attr
 *
 * If avpair is NULL, checks the status of the specified computer account.
 * Otherwise, looks up the value of the specified computer account's attribute.
 * If found, the value field of the avpair will be allocated and set. The
 * caller should free the allocated buffer.  Caller avpair requests are:
 *   smb_ads_find_computer() asks for SMB_ADS_ATTR_DN
 *   smb_ads_lookup_computer_attr_kvno() SMB_ADS_ATTR_KVNO
 *
 * Return:
 *  SMB_ADS_STAT_FOUND  - if both the computer and the specified attribute is
 *                        found.
 *  SMB_ADS_STAT_NOT_FOUND - if either the computer or the specified attribute
 *                           is not found.
 *  SMB_ADS_STAT_DUP - if the computer account is already used by other systems
 *                     in the AD. This could happen if the hostname of multiple
 *                     systems resolved to the same NetBIOS name.
 *  SMB_ADS_STAT_ERR - any failure.
 */
static smb_ads_qstat_t
smb_ads_lookup_computer_n_attr(smb_ads_handle_t *ah, smb_ads_avpair_t *avpair,
    int scope, char *dn)
{
	char *attrs[3], filter[SMB_ADS_MAXBUFLEN];
	LDAPMessage *res;
	char sam_acct[SMB_SAMACCT_MAXLEN];
	char tmpbuf[SMB_ADS_MAXBUFLEN];
	smb_ads_qstat_t rc;
	int err;

	if (smb_getsamaccount(sam_acct, sizeof (sam_acct)) != 0)
		return (SMB_ADS_STAT_ERR);

	res = NULL;
	attrs[0] = SMB_ADS_ATTR_DNSHOST;
	attrs[1] = NULL;
	attrs[2] = NULL;

	if (avpair) {
		if (!avpair->avp_attr)
			return (SMB_ADS_STAT_ERR);

		attrs[1] = avpair->avp_attr;
	}

	if (smb_ads_escape_search_filter_chars(sam_acct, tmpbuf) != 0)
		return (SMB_ADS_STAT_ERR);

	(void) snprintf(filter, sizeof (filter),
	    "(&(objectClass=computer)(%s=%s))",
	    SMB_ADS_ATTR_SAMACCT, tmpbuf);

	syslog(LOG_DEBUG, "smbns: lookup_computer, "
	    "dn=%s, scope=%d", dn, scope);
	syslog(LOG_DEBUG, "smbns: lookup_computer, "
	    "filter=%s", filter);
	syslog(LOG_DEBUG, "smbns: lookup_computer, "
	    "attrs[0]=%s", attrs[0]);
	syslog(LOG_DEBUG, "smbns: lookup_computer, "
	    "attrs[1]=%s", attrs[1] ? attrs[1] : "");

	err = ldap_search_s(ah->ld, dn, scope, filter, attrs, 0, &res);
	if (err != LDAP_SUCCESS) {
		syslog(LOG_DEBUG, "smbns: lookup_computer, "
		    "LDAP search failed, dn=(%s), scope=%d, err=%s",
		    dn, scope, ldap_err2string(err));
		(void) ldap_msgfree(res);
		return (SMB_ADS_STAT_NOT_FOUND);
	}
	syslog(LOG_DEBUG, "smbns: find_computer, ldap_search OK");

	rc = smb_ads_get_qstat(ah, res, avpair);
	if (rc == SMB_ADS_STAT_FOUND) {
		syslog(LOG_DEBUG, "smbns: find_computer, attr %s = %s",
		    avpair->avp_attr, avpair->avp_val);
	} else {
		syslog(LOG_DEBUG, "smbns: find_computer, "
		    "get query status, error %d", rc);
	}

	/* free the search results */
	(void) ldap_msgfree(res);

	return (rc);
}

/*
 * smb_ads_find_computer
 *
 * Searches the directory for the machine account (SamAccountName)
 * If found, 'dn' will be set to the distinguished name of the system's
 * AD computer object.
 */
static smb_ads_qstat_t
smb_ads_find_computer(smb_ads_handle_t *ah, char *dn)
{
	smb_ads_qstat_t stat;
	smb_ads_avpair_t avpair;

	avpair.avp_attr = SMB_ADS_ATTR_DN;
	avpair.avp_val = NULL;

	(void) strlcpy(dn, ah->domain_dn, SMB_ADS_DN_MAX);
	stat = smb_ads_lookup_computer_n_attr(ah, &avpair,
	    LDAP_SCOPE_SUBTREE, dn);

	if (stat == SMB_ADS_STAT_FOUND) {
		(void) strlcpy(dn, avpair.avp_val, SMB_ADS_DN_MAX);
		free(avpair.avp_val);
	}

	return (stat);
}

/*
 * smb_ads_update_computer_cntrl_attr
 *
 * Modify the user account control attribute of an existing computer
 * object on AD.
 *
 * Returns LDAP error code.
 */
static int
smb_ads_update_computer_cntrl_attr(smb_ads_handle_t *ah, int flags, char *dn)
{
	LDAPMod *attrs[2];
	char *ctl_val[2];
	int ret = 0;
	char usrctl_buf[16];

	if (smb_ads_alloc_attr(attrs, sizeof (attrs) / sizeof (LDAPMod *)) != 0)
		return (LDAP_NO_MEMORY);

	attrs[0]->mod_op = LDAP_MOD_REPLACE;
	attrs[0]->mod_type = SMB_ADS_ATTR_CTL;

	(void) snprintf(usrctl_buf, sizeof (usrctl_buf), "%d", flags);
	ctl_val[0] = usrctl_buf;
	ctl_val[1] = 0;
	attrs[0]->mod_values = ctl_val;
	if ((ret = ldap_modify_s(ah->ld, dn, attrs)) != LDAP_SUCCESS) {
		syslog(LOG_NOTICE, "ldap_modify: %s", ldap_err2string(ret));
	}

	smb_ads_free_attr(attrs);
	return (ret);
}

/*
 * smb_ads_lookup_computer_attr_kvno
 *
 * Lookup the value of the Kerberos version number attribute of the computer
 * account.
 */
static krb5_kvno
smb_ads_lookup_computer_attr_kvno(smb_ads_handle_t *ah, char *dn)
{
	smb_ads_avpair_t avpair;
	int kvno = 1;

	avpair.avp_attr = SMB_ADS_ATTR_KVNO;
	avpair.avp_val = NULL;
	if (smb_ads_lookup_computer_n_attr(ah, &avpair,
	    LDAP_SCOPE_BASE, dn) == SMB_ADS_STAT_FOUND) {
		kvno = atoi(avpair.avp_val);
		free(avpair.avp_val);
	}

	return (kvno);
}

/*
 * smb_ads_join
 *
 * Besides the NT-4 style domain join (using MS-RPC), CIFS server also
 * provides the domain join using Kerberos Authentication, Keberos
 * Change & Set password, and LDAP protocols. Basically, AD join
 * operation would require the following tickets to be acquired for the
 * the user account that is provided for the domain join.
 *
 * 1) a Keberos TGT ticket,
 * 2) a ldap service ticket, and
 * 3) kadmin/changpw service ticket
 *
 * The ADS client first sends a ldap search request to find out whether
 * or not the workstation trust account already exists in the Active Directory.
 * The existing computer object for this workstation will be removed and
 * a new one will be added. The machine account password is randomly
 * generated and set for the newly created computer object using KPASSWD
 * protocol (See RFC 3244). Once the password is set, our ADS client
 * finalizes the machine account by modifying the user acount control
 * attribute of the computer object. Kerberos keys derived from the machine
 * account password will be stored locally in /etc/krb5/krb5.keytab file.
 * That would be needed while acquiring Kerberos TGT ticket for the host
 * principal after the domain join operation.
 */
smb_ads_status_t
smb_ads_join(char *domain, char *container,
    char *user, char *usr_passwd, char *machine_passwd)
{
	smb_ads_handle_t *ah = NULL;
	krb5_context ctx = NULL;
	krb5_principal *krb5princs = NULL;
	krb5_kvno kvno;
	boolean_t delete = B_TRUE;
	smb_ads_status_t rc;
	boolean_t new_acct;
	int dclevel, num, usrctl_flags = 0;
	smb_ads_qstat_t qstat;
	char dn[SMB_ADS_DN_MAX];
	char tmpfile[] = SMBNS_KRB5_KEYTAB_TMP;
	int cnt, x;
	smb_krb5_pn_set_t spns;
	krb5_enctype *encptr;

	rc = smb_ads_open_main(&ah, domain, user, usr_passwd);
	if (rc != 0) {
		const char *s = smb_ads_strerror(rc);
		syslog(LOG_ERR, "smb_ads_join: open_main, error %s", s);
		smb_ccache_remove(SMB_CCACHE_PATH);
		return (rc);
	}

	if ((dclevel = smb_ads_get_dc_level(ah)) == -1) {
		smb_ads_close(ah);
		smb_ccache_remove(SMB_CCACHE_PATH);
		return (SMB_ADJOIN_ERR_GET_DCLEVEL);
	}

	qstat = smb_ads_find_computer(ah, dn);
	switch (qstat) {
	case SMB_ADS_STAT_FOUND:
		new_acct = B_FALSE;
		syslog(LOG_INFO, "smb_ads_join: machine account found."
		    " Updating: %s", dn);
		if (smb_ads_modify_computer(ah, dclevel, dn) != 0) {
			smb_ads_close(ah);
			smb_ccache_remove(SMB_CCACHE_PATH);
			return (SMB_ADJOIN_ERR_MOD_TRUST_ACCT);
		}
		break;

	case SMB_ADS_STAT_NOT_FOUND:
		new_acct = B_TRUE;
		smb_ads_get_new_comp_dn(ah, dn, SMB_ADS_DN_MAX, container);
		syslog(LOG_INFO, "smb_ads_join: machine account not found."
		    " Creating: %s", dn);
		if (smb_ads_add_computer(ah, dclevel, dn) != 0) {
			smb_ads_close(ah);
			smb_ccache_remove(SMB_CCACHE_PATH);
			return (SMB_ADJOIN_ERR_ADD_TRUST_ACCT);
		}
		break;

	default:
		syslog(LOG_INFO, "smb_ads_find_computer, rc=%d", qstat);
		if (qstat == SMB_ADS_STAT_DUP)
			rc = SMB_ADJOIN_ERR_DUP_TRUST_ACCT;
		else
			rc = SMB_ADJOIN_ERR_TRUST_ACCT;
		smb_ads_close(ah);
		smb_ccache_remove(SMB_CCACHE_PATH);
		return (rc);
	}

	if (smb_krb5_ctx_init(&ctx) != 0) {
		rc = SMB_ADJOIN_ERR_INIT_KRB_CTX;
		goto adjoin_cleanup;
	}

	if (smb_krb5_get_pn_set(&spns, SMB_PN_KEYTAB_ENTRY, ah->domain) == 0) {
		rc = SMB_ADJOIN_ERR_GET_SPNS;
		goto adjoin_cleanup;
	}

	if (smb_krb5_get_kprincs(ctx, spns.s_pns, spns.s_cnt, &krb5princs)
	    != 0) {
		smb_krb5_free_pn_set(&spns);
		rc = SMB_ADJOIN_ERR_GET_SPNS;
		goto adjoin_cleanup;
	}

	cnt = spns.s_cnt;
	smb_krb5_free_pn_set(&spns);

	/* New machine_passwd was filled in by our caller. */
	if (smb_krb5_setpwd(ctx, ah->domain, machine_passwd) != 0) {
		rc = SMB_ADJOIN_ERR_KSETPWD;
		goto adjoin_cleanup;
	}

	kvno = smb_ads_lookup_computer_attr_kvno(ah, dn);

	/*
	 * Only members of Domain Admins and Enterprise Admins can set
	 * the TRUSTED_FOR_DELEGATION userAccountControl flag.
	 * Try to set this, but don't fail the join if we can't.
	 * Look into just removing this...
	 */
	usrctl_flags = (
	    SMB_ADS_USER_ACCT_CTL_WKSTATION_TRUST_ACCT |
	    SMB_ADS_USER_ACCT_CTL_TRUSTED_FOR_DELEGATION |
	    SMB_ADS_USER_ACCT_CTL_DONT_EXPIRE_PASSWD);
set_ctl_again:
	x = smb_ads_update_computer_cntrl_attr(ah, usrctl_flags, dn);
	if (x != LDAP_SUCCESS && (usrctl_flags &
	    SMB_ADS_USER_ACCT_CTL_TRUSTED_FOR_DELEGATION) != 0) {
		syslog(LOG_NOTICE, "Unable to set the "
"TRUSTED_FOR_DELEGATION userAccountControl flag on the "
"machine account in Active Directory.  It may be necessary "
"to set that via Active Directory administration.");
		usrctl_flags &=
		    ~SMB_ADS_USER_ACCT_CTL_TRUSTED_FOR_DELEGATION;
		goto set_ctl_again;
	}
	if (x != LDAP_SUCCESS) {
		rc = SMB_ADJOIN_ERR_UPDATE_CNTRL_ATTR;
		goto adjoin_cleanup;
	}

	if (mktemp(tmpfile) == NULL) {
		rc = SMB_ADJOIN_ERR_WRITE_KEYTAB;
		goto adjoin_cleanup;
	}

	encptr = smb_ads_get_enctypes(dclevel, &num);
	if (smb_krb5_kt_populate(ctx, ah->domain, krb5princs, cnt,
	    tmpfile, kvno, machine_passwd, encptr, num) != 0) {
		rc = SMB_ADJOIN_ERR_WRITE_KEYTAB;
		goto adjoin_cleanup;
	}

	delete = B_FALSE;
	rc = SMB_ADS_SUCCESS;

adjoin_cleanup:
	if (new_acct && delete)
		smb_ads_del_computer(ah, dn);

	if (rc != SMB_ADJOIN_ERR_INIT_KRB_CTX) {
		if (rc != SMB_ADJOIN_ERR_GET_SPNS)
			smb_krb5_free_kprincs(ctx, krb5princs, cnt);
		smb_krb5_ctx_fini(ctx);
	}

	/* commit keytab file */
	if (rc == SMB_ADS_SUCCESS) {
		if (rename(tmpfile, SMBNS_KRB5_KEYTAB) != 0) {
			(void) unlink(tmpfile);
			rc = SMB_ADJOIN_ERR_COMMIT_KEYTAB;
		}
	} else {
		(void) unlink(tmpfile);
	}

	smb_ads_close(ah);
	smb_ccache_remove(SMB_CCACHE_PATH);
	return (rc);
}

struct xlate_table {
	int err;
	const char * const msg;
};

static const struct xlate_table
adjoin_table[] = {
	{ SMB_ADS_SUCCESS, "Success" },
	{ SMB_ADS_KRB5_INIT_CTX,
	    "Failed creating a Kerberos context." },
	{ SMB_ADS_KRB5_CC_DEFAULT,
	    "Failed to resolve default credential cache." },
	{ SMB_ADS_KRB5_PARSE_PRINCIPAL,
	    "Failed parsing the user principal name." },
	{ SMB_ADS_KRB5_GET_INIT_CREDS_OTHER,
	    "Failed getting initial credentials.  (See svc. log)" },
	{ SMB_ADS_KRB5_GET_INIT_CREDS_PW,
	    "Failed getting initial credentials.  (Wrong password?)" },
	{ SMB_ADS_KRB5_GET_INIT_CREDS_SKEW,
	    "Failed getting initial credentials.  (Clock skew too great)" },
	{ SMB_ADS_KRB5_CC_INITIALIZE,
	    "Failed initializing the credential cache." },
	{ SMB_ADS_KRB5_CC_STORE_CRED,
	    "Failed to update the credential cache." },
	{ SMB_ADS_CANT_LOCATE_DC,
	    "Failed to locate a domain controller." },
	{ SMB_ADS_LDAP_INIT,
	    "Failed to create an LDAP handle." },
	{ SMB_ADS_LDAP_SETOPT,
	    "Failed to set an LDAP option." },
	{ SMB_ADS_LDAP_SET_DOM,
	    "Failed to set the LDAP handle DN." },
	{ SMB_ADS_LDAP_SASL_BIND,
	    "Failed to bind the LDAP handle. "
	    "Usually indicates an authentication problem." },

	{ SMB_ADJOIN_ERR_GEN_PWD,
	    "Failed to generate machine password." },
	{ SMB_ADJOIN_ERR_GET_DCLEVEL, "Unknown functional level of "
	    "the domain controller. The rootDSE attribute named "
	    "\"domainControllerFunctionality\" is missing from the "
	    "Active Directory." },
	{ SMB_ADJOIN_ERR_ADD_TRUST_ACCT, "Failed to create the "
	    "workstation trust account." },
	{ SMB_ADJOIN_ERR_MOD_TRUST_ACCT, "Failed to modify the "
	    "workstation trust account." },
	{ SMB_ADJOIN_ERR_DUP_TRUST_ACCT, "Failed to create the "
	    "workstation trust account because its name is already "
	    "in use." },
	{ SMB_ADJOIN_ERR_TRUST_ACCT, "Error in querying the "
	    "workstation trust account" },
	{ SMB_ADJOIN_ERR_INIT_KRB_CTX, "Failed to initialize Kerberos "
	    "context." },
	{ SMB_ADJOIN_ERR_GET_SPNS, "Failed to get Kerberos "
	    "principals." },
	{ SMB_ADJOIN_ERR_KSETPWD, "Failed to set machine password." },
	{ SMB_ADJOIN_ERR_UPDATE_CNTRL_ATTR,  "Failed to modify "
	    "userAccountControl attribute of the workstation trust "
	    "account." },
	{ SMB_ADJOIN_ERR_WRITE_KEYTAB, "Error in writing to local "
	    "keytab file (i.e /etc/krb5/krb5.keytab)." },
	{ SMB_ADJOIN_ERR_IDMAP_SET_DOMAIN, "Failed to update idmap "
	    "configuration." },
	{ SMB_ADJOIN_ERR_IDMAP_REFRESH, "Failed to refresh idmap "
	    "service." },
	{ SMB_ADJOIN_ERR_COMMIT_KEYTAB, "Failed to commit changes to "
	    "local keytab file (i.e. /etc/krb5/krb5.keytab)." },
	{ SMB_ADJOIN_ERR_AUTH_NETLOGON,
	    "Failed to authenticate using the new computer account." },
	{ SMB_ADJOIN_ERR_STORE_PROPS,
	    "Failed to store computer account information locally." },
	{ 0, NULL }
};

/*
 * smb_ads_strerror
 *
 * Lookup an error message for the specific adjoin error code.
 */
const char *
smb_ads_strerror(int err)
{
	const struct xlate_table *xt;

	if (err > 0 && err < SMB_ADS_ERRNO_GAP)
		return (strerror(err));

	for (xt = adjoin_table; xt->msg; xt++)
		if (xt->err == err)
			return (xt->msg);

	return ("Unknown error code.");
}

void
smb_ads_log_errmsg(smb_ads_status_t err)
{
	const char *s = smb_ads_strerror(err);
	syslog(LOG_NOTICE, "%s", s);
}


/*
 * smb_ads_lookup_msdcs
 *
 * If server argument is set, try to locate the specified DC.
 * If it is set to empty string, locate any DCs in the specified domain.
 * Returns the discovered DC via buf.
 *
 * fqdn	  - fully-qualified domain name
 * dci    - the name and address of the found DC
 */
uint32_t
smb_ads_lookup_msdcs(char *fqdn, smb_dcinfo_t *dci)
{
	smb_ads_host_info_t *hinfo = NULL;
	char ipstr[INET6_ADDRSTRLEN];

	if (!fqdn || !dci)
		return (NT_STATUS_INTERNAL_ERROR);

	ipstr[0] = '\0';
	if ((hinfo = smb_ads_find_host(fqdn)) == NULL)
		return (NT_STATUS_DOMAIN_CONTROLLER_NOT_FOUND);

	(void) smb_inet_ntop(&hinfo->ipaddr, ipstr,
	    SMB_IPSTRLEN(hinfo->ipaddr.a_family));
	smb_tracef("msdcsLookupADS: %s [%s]", hinfo->name, ipstr);

	(void) strlcpy(dci->dc_name, hinfo->name, sizeof (dci->dc_name));
	dci->dc_addr = hinfo->ipaddr;
	dci->dc_flags = hinfo->flags;

	free(hinfo);
	return (NT_STATUS_SUCCESS);
}

static krb5_enctype *
smb_ads_get_enctypes(int dclevel, int *num)
{
	krb5_enctype *encptr;

	if (dclevel >= SMB_ADS_DCLEVEL_W2K8) {
		*num = sizeof (w2k8enctypes) / sizeof (krb5_enctype);
		encptr = w2k8enctypes;
	} else {
		*num = sizeof (pre_w2k8enctypes) / sizeof (krb5_enctype);
		encptr = pre_w2k8enctypes;
	}

	return (encptr);
}