libsmb/common/smb_nic.c

	smb_nic.c revision 9fb67ea305c66b6a297583b9b0db6796b0dfe497
/*
 * 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 2010 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#include <stdio.h>
#include <stdlib.h>
#include <syslog.h>
#include <libintl.h>
#include <strings.h>
#include <string.h>
#include <unistd.h>
#include <synch.h>
#include <stropts.h>
#include <errno.h>
#include <pthread.h>

#include <inet/ip.h>
#include <net/if.h>
#include <netinet/in.h>
#include <netdb.h>
#include <net/route.h>
#include <arpa/inet.h>

#include <sys/socket.h>
#include <sys/sockio.h>
#include <sys/systeminfo.h>

#include <smbsrv/libsmb.h>

#define SMB_NIC_DB_NAME     "/var/smb/smbhosts.db"
#define SMB_NIC_DB_TIMEOUT  3000        /* in millisecond */
#define SMB_NIC_DB_VERMAJOR 1
#define SMB_NIC_DB_VERMINOR 0
#define SMB_NIC_DB_MAGIC    0x484F5354  /* HOST */

#define SMB_NIC_DB_ORD      1       /* open read-only */
#define SMB_NIC_DB_ORW      2       /* open read/write */

#define SMB_NIC_DB_SQL \
    "CREATE TABLE db_info ("                \
    "   ver_major INTEGER,"             \
    "   ver_minor INTEGER,"             \
    "   magic     INTEGER"              \
    ");"                            \
    ""                          \
    "CREATE TABLE hosts ("                  \
    "   hostname  TEXT PRIMARY KEY,"            \
    "   comment   TEXT,"                \
    "   ifnames   TEXT"                 \
    ");"

#define SMB_NIC_HTBL_NCOL   3
#define SMB_NIC_HTBL_HOST   0
#define SMB_NIC_HTBL_CMNT   1
#define SMB_NIC_HTBL_IFS    2

#define NULL_MSGCHK(msg)    ((msg) ? (msg) : "NULL")

#define SMB_NIC_MAXIFS      256
#define SMB_NIC_MAXEXCLLIST_LEN 512

typedef struct smb_hostifs {
    list_node_t if_lnd;
    char if_host[MAXHOSTNAMELEN];
    char if_cmnt[SMB_PI_MAX_COMMENT];
    char *if_names[SMB_NIC_MAXIFS];
    int if_num;
} smb_hostifs_t;

typedef struct smb_hosts {
    list_t h_list;
    int h_num;
    int h_ifnum;
} smb_hosts_t;

typedef struct {
    smb_nic_t   *nl_nics;
    int     nl_cnt;     /* number of smb_nic_t structures */
    int     nl_hcnt;    /* number of host names */
    long        nl_seqnum;  /* a random sequence number */
    rwlock_t    nl_rwl;
} smb_niclist_t;

static int smb_nic_list_create(void);
static void smb_nic_list_destroy(void);

static int smb_nic_hlist_create(smb_hosts_t *);
static void smb_nic_hlist_destroy(smb_hosts_t *);
static int smb_nic_hlist_dbget(smb_hosts_t *);
static int smb_nic_hlist_sysget(smb_hosts_t *);

static void smb_nic_iflist_destroy(smb_hostifs_t *);
static smb_hostifs_t *smb_nic_iflist_decode(const char **, int *);

static int smb_nic_dbcreate(void);
static sqlite *smb_nic_dbopen(int);
static void smb_nic_dbclose(sqlite *);
static boolean_t smb_nic_dbexists(void);
static boolean_t smb_nic_dbvalidate(void);
static int smb_nic_dbaddhost(const char *, const char *, char *);
static int smb_nic_dbdelhost(const char *);
static int smb_nic_dbsetinfo(sqlite *);

static int smb_nic_getinfo(char *, smb_nic_t *, int);
static boolean_t smb_nic_nbt_exclude(const smb_nic_t *, const char **, int);
static int smb_nic_nbt_get_exclude_list(char *, char **, int);

static void smb_close_sockets(int, int);
static boolean_t smb_duplicate_nic(smb_hostifs_t *iflist, struct lifreq *lifrp);

/* This is the list we will monitor */
static smb_niclist_t smb_niclist;

/*
 * smb_nic_init
 *
 * Initializes the interface list.
 */
int
smb_nic_init(void)
{
    int rc;

    (void) rw_wrlock(&smb_niclist.nl_rwl);
    smb_nic_list_destroy();
    rc = smb_nic_list_create();
    (void) rw_unlock(&smb_niclist.nl_rwl);

    return (rc);
}

/*
 * smb_nic_fini
 *
 * Destroys the interface list.
 */
void
smb_nic_fini(void)
{
    (void) rw_wrlock(&smb_niclist.nl_rwl);
    smb_nic_list_destroy();
    (void) rw_unlock(&smb_niclist.nl_rwl);
}

/*
 * smb_nic_getnum
 *
 * Gets the number of interfaces for the specified host.
 * if host is NULL then total number of interfaces
 * is returned. It's assumed that given name is a NetBIOS
 * encoded name.
 */
int
smb_nic_getnum(char *nb_hostname)
{
    int n = 0, i;

    (void) rw_rdlock(&smb_niclist.nl_rwl);

    if (nb_hostname != NULL) {
        for (i = 0; i < smb_niclist.nl_cnt; i++) {
            /* ignore the suffix */
            if (strncasecmp(smb_niclist.nl_nics[i].nic_nbname,
                nb_hostname, NETBIOS_NAME_SZ - 1) == 0)
                n++;
        }
    } else {
        n = smb_niclist.nl_cnt;
    }

    (void) rw_unlock(&smb_niclist.nl_rwl);

    return (n);
}

/*
 * smb_nic_getfirst
 *
 * Returns the first NIC in the interface list and
 * initializes the given iterator. To get the rest of
 * NICs smb_nic_getnext() must be called.
 *
 * Returns SMB_NIC_SUCCESS upon success or the following:
 *  SMB_NIC_NOT_FOUND - there's no interface available
 *  SMB_NIC_INVALID_ARG - 'ni' is NULL
 */
int
smb_nic_getfirst(smb_niciter_t *ni)
{
    int rc = SMB_NIC_SUCCESS;

    if (ni == NULL)
        return (SMB_NIC_INVALID_ARG);

    (void) rw_rdlock(&smb_niclist.nl_rwl);

    if (smb_niclist.nl_cnt > 0) {
        ni->ni_nic = smb_niclist.nl_nics[0];
        ni->ni_cookie = 1;
        ni->ni_seqnum = smb_niclist.nl_seqnum;
    } else {
        rc = SMB_NIC_NOT_FOUND;
    }

    (void) rw_unlock(&smb_niclist.nl_rwl);

    return (rc);
}

/*
 * smb_nic_getnext
 *
 * Returns the next NIC information based on the passed
 * iterator (ni). The iterator must have previously been
 * initialized by calling smb_nic_getfirst().
 *
 * Returns SMB_NIC_SUCCESS upon successfully finding the specified NIC
 * or the following:
 *  SMB_NIC_INVALID_ARG - the specified iterator is invalid
 *  SMB_NIC_NO_MORE - reaches the end of the NIC list
 *  SMB_NIC_CHANGED - sequence number in the iterator is different from
 *    the sequence number in the NIC list which means
 *    the list has been changed between getfirst/getnext
 *    calls.
 */
int
smb_nic_getnext(smb_niciter_t *ni)
{
    int rc = SMB_NIC_SUCCESS;

    if ((ni == NULL) || (ni->ni_cookie < 1))
        return (SMB_NIC_INVALID_ARG);

    (void) rw_rdlock(&smb_niclist.nl_rwl);

    if ((smb_niclist.nl_cnt > ni->ni_cookie) &&
        (smb_niclist.nl_seqnum == ni->ni_seqnum)) {
        ni->ni_nic = smb_niclist.nl_nics[ni->ni_cookie];
        ni->ni_cookie++;
    } else {
        if (smb_niclist.nl_seqnum != ni->ni_seqnum)
            rc = SMB_NIC_CHANGED;
        else
            rc = SMB_NIC_NO_MORE;
    }

    (void) rw_unlock(&smb_niclist.nl_rwl);

    return (rc);
}

boolean_t
smb_nic_is_local(smb_inaddr_t *ipaddr)
{
    smb_nic_t *cfg;
    int i;

    (void) rw_rdlock(&smb_niclist.nl_rwl);

    for (i = 0; i < smb_niclist.nl_cnt; i++) {
        cfg = &smb_niclist.nl_nics[i];
        if (smb_inet_equal(ipaddr, &cfg->nic_ip)) {
            (void) rw_unlock(&smb_niclist.nl_rwl);
            return (B_TRUE);
        }
    }
    (void) rw_unlock(&smb_niclist.nl_rwl);
    return (B_FALSE);
}

boolean_t
smb_nic_is_same_subnet(smb_inaddr_t *ipaddr)
{
    smb_nic_t *cfg;
    int i;

    (void) rw_rdlock(&smb_niclist.nl_rwl);

    for (i = 0; i < smb_niclist.nl_cnt; i++) {
        cfg = &smb_niclist.nl_nics[i];
        if (smb_inet_same_subnet(ipaddr, &cfg->nic_ip, cfg->nic_mask)) {
            (void) rw_unlock(&smb_niclist.nl_rwl);
            return (B_TRUE);
        }
    }
    (void) rw_unlock(&smb_niclist.nl_rwl);
    return (B_FALSE);
}

/*
 * smb_nic_addhost
 *
 * Adds an association between the given host and the specified interface
 * list (if_names). This function can be called as many times as needed,
 * the associations will be stored in /var/smb/smbhosts.db, which is sqlite
 * database. If this file exists and it's not empty NIC list is generated
 * based on the information stored in this file.
 *
 * host: actual system's name (not Netbios name)
 * cmnt: an optional description for the CIFS server running on
 *       the specified host. Can be NULL.
 * if_num: number of interface names in if_names arg
 * if_names: array of interface names in string format
 *
 * Returns SMB_NIC_SUCCESS upon success, a nonzero value otherwise.
 */
int
smb_nic_addhost(const char *host, const char *cmnt,
    int if_num, const char **if_names)
{
    char *if_list;
    char *ifname;
    int buflen = 0;
    int rc, i;

    if ((host == NULL) || (if_num <= 0) || (if_names == NULL))
        return (SMB_NIC_INVALID_ARG);

    if (!smb_nic_dbexists() || !smb_nic_dbvalidate()) {
        if ((rc = smb_nic_dbcreate()) != SMB_NIC_SUCCESS)
            return (rc);
    }

    for (i = 0; i < if_num; i++) {
        ifname = (char *)if_names[i];
        if ((ifname == NULL) || (*ifname == '\0'))
            return (SMB_NIC_INVALID_ARG);
        buflen += strlen(ifname) + 1;
    }

    if ((if_list = malloc(buflen)) == NULL)
        return (SMB_NIC_NO_MEMORY);

    ifname = if_list;
    for (i = 0; i < if_num - 1; i++)
        ifname += snprintf(ifname, buflen, "%s,", if_names[i]);

    (void) snprintf(ifname, buflen, "%s", if_names[i]);

    rc = smb_nic_dbaddhost(host, cmnt, if_list);
    free(if_list);

    return (rc);
}

/*
 * smb_nic_delhost
 *
 * Removes the stored interface association for the specified host
 */
int
smb_nic_delhost(const char *host)
{
    if ((host == NULL) || (*host == '\0'))
        return (SMB_NIC_INVALID_ARG);

    if (!smb_nic_dbexists())
        return (SMB_NIC_SUCCESS);

    if (!smb_nic_dbvalidate()) {
        (void) unlink(SMB_NIC_DB_NAME);
        return (SMB_NIC_SUCCESS);
    }

    return (smb_nic_dbdelhost(host));
}

/*
 * smb_nic_list_create
 *
 * Creates a NIC list either based on /var/smb/smbhosts.db or
 * by getting the information from OS.
 *
 * Note that the caller of this function should grab the
 * list lock.
 */
static int
smb_nic_list_create(void)
{
    smb_hosts_t hlist;
    smb_hostifs_t *iflist;
    smb_nic_t *nc;
    char *ifname;
    char excludestr[SMB_NIC_MAXEXCLLIST_LEN];
    char *exclude[SMB_PI_MAX_NETWORKS];
    int nexclude = 0;
    int i, rc;

    if ((rc = smb_nic_hlist_create(&hlist)) !=  SMB_NIC_SUCCESS)
        return (rc);

    smb_niclist.nl_cnt = 0;
    smb_niclist.nl_seqnum = random();
    smb_niclist.nl_hcnt = hlist.h_num;

    smb_niclist.nl_nics = calloc(hlist.h_ifnum, sizeof (smb_nic_t));
    if (smb_niclist.nl_nics == NULL) {
        smb_nic_hlist_destroy(&hlist);
        return (SMB_NIC_NO_MEMORY);
    }

    *excludestr = '\0';
    (void) smb_config_getstr(SMB_CI_WINS_EXCL,
        excludestr, sizeof (excludestr));

    nexclude = smb_nic_nbt_get_exclude_list(excludestr,
        exclude, SMB_PI_MAX_NETWORKS);

    nc = smb_niclist.nl_nics;
    iflist = list_head(&hlist.h_list);

    do {
        for (i = 0; i < iflist->if_num; i++) {
            ifname = iflist->if_names[i];
            if (smb_nic_getinfo(ifname, nc, AF_INET) !=
                SMB_NIC_SUCCESS) {
                if (smb_nic_getinfo(ifname, nc,
                    AF_INET6) != SMB_NIC_SUCCESS) {
                    continue;
                }
            }

            (void) strlcpy(nc->nic_host, iflist->if_host,
                sizeof (nc->nic_host));
            (void) strlcpy(nc->nic_cmnt, iflist->if_cmnt,
                sizeof (nc->nic_cmnt));

            smb_tonetbiosname(nc->nic_host, nc->nic_nbname, 0x00);

            if (strchr(ifname, ':'))
                nc->nic_smbflags |= SMB_NICF_ALIAS;

            if (smb_nic_nbt_exclude(nc,
                (const char **)exclude, nexclude))
                nc->nic_smbflags |= SMB_NICF_NBEXCL;

            smb_niclist.nl_cnt++;
            nc++;
        }
    } while ((iflist = list_next(&hlist.h_list, iflist)) != NULL);

    smb_nic_hlist_destroy(&hlist);

    return (SMB_NIC_SUCCESS);
}

static void
smb_nic_list_destroy(void)
{
    free(smb_niclist.nl_nics);
    smb_niclist.nl_nics = NULL;
    smb_niclist.nl_cnt = 0;
}

static int
smb_nic_getinfo(char *interface, smb_nic_t *nc, int family)
{
    struct lifreq lifrr;
    int s;
    boolean_t isv6;
    struct sockaddr_in6 *sin6;
    struct sockaddr_in *sin;

    if ((s = socket(family, SOCK_DGRAM, IPPROTO_IP)) < 0) {
        return (SMB_NIC_SOCK);
    }

    (void) strlcpy(lifrr.lifr_name, interface, sizeof (lifrr.lifr_name));
    if (ioctl(s, SIOCGLIFADDR, &lifrr) < 0) {
        (void) close(s);
        return (SMB_NIC_IOCTL);
    }
    isv6 = (lifrr.lifr_addr.ss_family == AF_INET6);
    if (isv6) {
        sin6 = (struct sockaddr_in6 *)(&lifrr.lifr_addr);
        nc->nic_ip.a_ipv6 = sin6->sin6_addr;
        nc->nic_ip.a_family = AF_INET6;
    } else {
        sin = (struct sockaddr_in *)(&lifrr.lifr_addr);
        nc->nic_ip.a_ipv4 = (in_addr_t)(sin->sin_addr.s_addr);
        nc->nic_ip.a_family = AF_INET;
    }
    if (smb_inet_iszero(&nc->nic_ip)) {
        (void) close(s);
        return (SMB_NIC_BAD_DATA);
    }
    /* there is no broadcast or netmask for v6 */
    if (!isv6) {
        if (ioctl(s, SIOCGLIFBRDADDR, &lifrr) < 0) {
            (void) close(s);
            return (SMB_NIC_IOCTL);
        }
        sin = (struct sockaddr_in *)&lifrr.lifr_broadaddr;
        nc->nic_bcast = (uint32_t)sin->sin_addr.s_addr;

        if (ioctl(s, SIOCGLIFNETMASK, &lifrr) < 0) {
            (void) close(s);
            return (SMB_NIC_IOCTL);
        }
        sin = (struct sockaddr_in *)&lifrr.lifr_addr;
        nc->nic_mask = (uint32_t)sin->sin_addr.s_addr;
    }
    if (ioctl(s, SIOCGLIFFLAGS, &lifrr) < 0) {
        (void) close(s);
        return (SMB_NIC_IOCTL);
    }
    nc->nic_sysflags = lifrr.lifr_flags;

    (void) strlcpy(nc->nic_ifname, interface, sizeof (nc->nic_ifname));

    (void) close(s);
    return (SMB_NIC_SUCCESS);
}

/*
 * smb_nic_hlist_create
 *
 * Creates a list of hosts and their associated interfaces.
 * If host database exists the information is retrieved from
 * the database, otherwise it's retrieved from OS.
 *
 * The allocated memories for the returned list should be freed
 * by calling smb_nic_hlist_destroy()
 */
static int
smb_nic_hlist_create(smb_hosts_t *hlist)
{
    int rc;

    list_create(&hlist->h_list, sizeof (smb_hostifs_t),
        offsetof(smb_hostifs_t, if_lnd));
    hlist->h_num = 0;
    hlist->h_ifnum = 0;

    if (smb_nic_dbexists() && smb_nic_dbvalidate()) {
        rc = smb_nic_hlist_dbget(hlist);
        errno = EBADF;
    } else {
        rc = smb_nic_hlist_sysget(hlist);
    }

    if (rc != SMB_NIC_SUCCESS)
        smb_nic_hlist_destroy(hlist);

    return (rc);
}

static void
smb_nic_hlist_destroy(smb_hosts_t *hlist)
{
    smb_hostifs_t *iflist;

    if (hlist == NULL)
        return;

    while ((iflist = list_head(&hlist->h_list)) != NULL) {
        list_remove(&hlist->h_list, iflist);
        smb_nic_iflist_destroy(iflist);
    }

    list_destroy(&hlist->h_list);
}

static void
smb_close_sockets(int s4, int s6)
{
    if (s4)
        (void) close(s4);
    if (s6)
        (void) close(s6);
}

/*
 * smb_nic_hlist_sysget
 *
 * Get the list of currently plumbed and up interface names. The loopback (lo0)
 * port is ignored
 */
static int
smb_nic_hlist_sysget(smb_hosts_t *hlist)
{
    smb_hostifs_t *iflist;
    struct lifconf lifc;
    struct lifreq lifrl;
    struct lifreq *lifrp;
    char *ifname;
    int ifnum;
    int i;
    int s4, s6;
    struct lifnum lifn;

    iflist = malloc(sizeof (smb_hostifs_t));
    if (iflist == NULL)
        return (SMB_NIC_NO_MEMORY);

    bzero(iflist, sizeof (smb_hostifs_t));

    if (smb_gethostname(iflist->if_host, sizeof (iflist->if_host),
        SMB_CASE_PRESERVE) < 0) {
        free(iflist);
        return (SMB_NIC_NO_HOST);
    }

    (void) smb_config_getstr(SMB_CI_SYS_CMNT, iflist->if_cmnt,
        sizeof (iflist->if_cmnt));

    if ((s4 = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
        free(iflist);
        return (SMB_NIC_SOCK);
    }
    s6 = socket(AF_INET6, SOCK_DGRAM, 0);

    lifn.lifn_family = AF_UNSPEC;
    lifn.lifn_flags = 0;
    if (ioctl(s4, SIOCGLIFNUM, (char *)&lifn) < 0) {
        smb_close_sockets(s4, s6);
        free(iflist);
        syslog(LOG_ERR, "hlist_sysget: SIOCGLIFNUM errno=%d", errno);
        return (SMB_NIC_IOCTL);
    }

    lifc.lifc_len = lifn.lifn_count * sizeof (struct lifreq);
    lifc.lifc_buf = malloc(lifc.lifc_len);
    if (lifc.lifc_buf == NULL) {
        smb_close_sockets(s4, s6);
        free(iflist);
        return (SMB_NIC_NO_MEMORY);
    }
    bzero(lifc.lifc_buf, lifc.lifc_len);
    lifc.lifc_family = AF_UNSPEC;
    lifc.lifc_flags = 0;

    if (ioctl(s4, SIOCGLIFCONF, (char *)&lifc) < 0) {
        smb_close_sockets(s4, s6);
        free(iflist);
        free(lifc.lifc_buf);
        return (SMB_NIC_IOCTL);
    }

    lifrp = lifc.lifc_req;
    ifnum = lifc.lifc_len / sizeof (struct lifreq);
    hlist->h_num = 0;
    for (i = 0; i < ifnum; i++, lifrp++) {

        if ((iflist->if_num > 0) && smb_duplicate_nic(iflist, lifrp))
            continue;
        /*
         * Get the flags so that we can skip the loopback interface
         */
        (void) memset(&lifrl, 0, sizeof (lifrl));
        (void) strlcpy(lifrl.lifr_name, lifrp->lifr_name,
            sizeof (lifrl.lifr_name));

        if (ioctl(s4, SIOCGLIFFLAGS, (caddr_t)&lifrl) < 0) {
            if ((s6 < 0) ||
                (ioctl(s6, SIOCGLIFFLAGS, (caddr_t)&lifrl) < 0)) {
                smb_close_sockets(s4, s6);
                free(lifc.lifc_buf);
                smb_nic_iflist_destroy(iflist);
                return (SMB_NIC_IOCTL);
            }
        }
        if (lifrl.lifr_flags & IFF_LOOPBACK) {
            continue;
        }

        if ((lifrl.lifr_flags & IFF_UP) == 0) {
            continue;
        }
        ifname = strdup(lifrp->lifr_name);
        if (ifname == NULL) {
            smb_close_sockets(s4, s6);
            free(lifc.lifc_buf);
            smb_nic_iflist_destroy(iflist);
            return (SMB_NIC_NO_MEMORY);
        }
        iflist->if_names[iflist->if_num++] = ifname;
    }
    hlist->h_ifnum = iflist->if_num;
    hlist->h_num = 1;
    smb_close_sockets(s4, s6);
    free(lifc.lifc_buf);
    list_insert_tail(&hlist->h_list, iflist);

    return (SMB_NIC_SUCCESS);
}

static boolean_t
smb_duplicate_nic(smb_hostifs_t *iflist, struct lifreq *lifrp)
{
    int j;
    /*
     * throw out duplicate names
     */
    for (j = 0; j < iflist->if_num; j++) {
        if (strcmp(iflist->if_names[j],
            lifrp->lifr_name) == 0)
            return (B_TRUE);
    }
    return (B_FALSE);
}

static int
smb_nic_hlist_dbget(smb_hosts_t *hlist)
{
    smb_hostifs_t *iflist;
    sqlite *db;
    sqlite_vm *vm;
    int err = SMB_NIC_SUCCESS;
    const char **values;
    char *sql;
    char *errmsg = NULL;
    int ncol, rc;

    sql = sqlite_mprintf("SELECT * FROM hosts");
    if (sql == NULL)
        return (SMB_NIC_NO_MEMORY);

    db = smb_nic_dbopen(SMB_NIC_DB_ORD);
    if (db == NULL) {
        sqlite_freemem(sql);
        return (SMB_NIC_DBOPEN_FAILED);
    }

    rc = sqlite_compile(db, sql, NULL, &vm, &errmsg);
    sqlite_freemem(sql);

    if (rc != SQLITE_OK) {
        smb_nic_dbclose(db);
        syslog(LOG_ERR, "Failed to query hosts info from host " \
            "database.  Unable to create virtual machine (%s).",
            NULL_MSGCHK(errmsg));
        return (SMB_NIC_DB_ERROR);
    }

    do {
        rc = sqlite_step(vm, &ncol, &values, NULL);
        if (rc == SQLITE_ROW) {
            if (ncol != SMB_NIC_HTBL_NCOL) {
                err = SMB_NIC_DB_ERROR;
                break;
            }

            if ((iflist = smb_nic_iflist_decode(values, &err)) ==
                NULL) {
                break;
            }

            list_insert_tail(&hlist->h_list, iflist);
            hlist->h_num++;
            hlist->h_ifnum += iflist->if_num;
        }
    } while (rc == SQLITE_ROW);

    if (rc != SQLITE_DONE && err == SMB_NIC_SUCCESS) {
        /* set this error if no previous error */
        err = SMB_LGRP_DBEXEC_FAILED;
    }

    rc = sqlite_finalize(vm, &errmsg);
    if (rc != SQLITE_OK) {
        syslog(LOG_ERR, "Failed to query hosts info from host " \
            "database.  Unable to destroy virtual machine (%s).",
            NULL_MSGCHK(errmsg));
        if (err == SMB_NIC_SUCCESS) {
            /* set this error if no previous error */
            err = SMB_NIC_DB_ERROR;
        }
    }

    smb_nic_dbclose(db);

    return (err);
}

static smb_hostifs_t *
smb_nic_iflist_decode(const char **values, int *err)
{
    smb_hostifs_t *iflist;
    char *host;
    char *cmnt;
    char *ifnames;
    char *lasts;
    char *ifname;
    int if_num = 0;

    host = (char *)values[SMB_NIC_HTBL_HOST];
    cmnt = (char *)values[SMB_NIC_HTBL_CMNT];
    ifnames = (char *)values[SMB_NIC_HTBL_IFS];

    if ((host == NULL) || (ifnames == NULL)) {
        *err = SMB_NIC_INVALID_ARG;
        return (NULL);
    }

    iflist = malloc(sizeof (smb_hostifs_t));
    if (iflist == NULL) {
        *err = SMB_NIC_NO_MEMORY;
        return (NULL);
    }

    bzero(iflist, sizeof (smb_hostifs_t));

    (void) strlcpy(iflist->if_host, host, sizeof (iflist->if_host));
    (void) strlcpy(iflist->if_cmnt, (cmnt) ? cmnt : "",
        sizeof (iflist->if_cmnt));

    if ((ifname = strtok_r(ifnames, ",", &lasts)) == NULL) {
        *err = SMB_NIC_BAD_DATA;
        return (NULL);
    }

    iflist->if_names[if_num++] = strdup(ifname);

    while ((ifname = strtok_r(NULL, ",", &lasts)) != NULL)
        iflist->if_names[if_num++] = strdup(ifname);

    iflist->if_num = if_num;

    for (if_num = 0; if_num < iflist->if_num; if_num++) {
        if (iflist->if_names[if_num] == NULL) {
            smb_nic_iflist_destroy(iflist);
            *err = SMB_NIC_NO_MEMORY;
            return (NULL);
        }
    }

    *err = SMB_NIC_SUCCESS;
    return (iflist);
}

/*
 * smb_nic_iflist_destroy
 *
 * Frees allocated memory for the given IF names lists.
 */
static void
smb_nic_iflist_destroy(smb_hostifs_t *iflist)
{
    int i;

    if (iflist == NULL)
        return;

    for (i = 0; i < iflist->if_num; i++)
        free(iflist->if_names[i]);

    free(iflist);
}

/*
 * Functions to manage host/interface database
 *
 * Each entry in the hosts table associates a hostname with a
 * list of interface names. The host/interface association could
 * be added by calling smb_nic_addhost() and could be removed by
 * calling smb_nic_delhost(). If the database exists and it contains
 * valid information then the inteface list wouldn't be obtained
 * from system using ioctl.
 */

/*
 * smb_nic_dbcreate
 *
 * Creates the host database based on the defined SQL statement.
 * It also initializes db_info table.
 */
static int
smb_nic_dbcreate(void)
{
    sqlite *db = NULL;
    char *errmsg = NULL;
    int rc, err = SMB_NIC_SUCCESS;

    (void) unlink(SMB_NIC_DB_NAME);

    db = sqlite_open(SMB_NIC_DB_NAME, 0600, &errmsg);
    if (db == NULL) {
        syslog(LOG_ERR, "Failed to create host database (%s).",
            NULL_MSGCHK(errmsg));
        sqlite_freemem(errmsg);
        return (SMB_NIC_DBOPEN_FAILED);
    }

    sqlite_busy_timeout(db, SMB_NIC_DB_TIMEOUT);
    rc = sqlite_exec(db, "BEGIN TRANSACTION", NULL, NULL, &errmsg);
    if (rc != SQLITE_OK) {
        syslog(LOG_ERR, "Failed to create host database.  Unable to " \
            "begin database transaction (%s).", NULL_MSGCHK(errmsg));
        sqlite_freemem(errmsg);
        sqlite_close(db);
        return (SMB_NIC_DBEXEC_FAILED);
    }

    if (sqlite_exec(db, SMB_NIC_DB_SQL, NULL, NULL, &errmsg) == SQLITE_OK) {
        rc = sqlite_exec(db, "COMMIT TRANSACTION", NULL, NULL,
            &errmsg);
        if (rc == SQLITE_OK)
            err = smb_nic_dbsetinfo(db);
        if (err != SMB_NIC_SUCCESS)
            rc = sqlite_exec(db, "ROLLBACK TRANSACTION", NULL, NULL,
                &errmsg);
    } else {
        syslog(LOG_ERR, "Failed to create host database.  Unable to " \
            "initialize host database (%s).", NULL_MSGCHK(errmsg));
        sqlite_freemem(errmsg);
        rc = sqlite_exec(db, "ROLLBACK TRANSACTION", NULL, NULL,
            &errmsg);
    }

    if (rc != SQLITE_OK) {
        /* this is bad - database may be left in a locked state */
        syslog(LOG_ERR, "Failed to create host database.  Unable to " \
            "close a transaction (%s).", NULL_MSGCHK(errmsg));
        sqlite_freemem(errmsg);
        err = SMB_NIC_DBINIT_FAILED;
    }

    (void) sqlite_close(db);
    return (err);
}

/*
 * smb_nic_dbopen
 *
 * Opens host database with the given mode.
 */
static sqlite *
smb_nic_dbopen(int mode)
{
    sqlite *db;
    char *errmsg = NULL;

    db = sqlite_open(SMB_NIC_DB_NAME, mode, &errmsg);
    if (db == NULL) {
        syslog(LOG_ERR, "Failed to open host database: %s (%s).",
            SMB_NIC_DB_NAME, NULL_MSGCHK(errmsg));
        sqlite_freemem(errmsg);
    }

    return (db);
}

/*
 * smb_nic_dbclose
 *
 * Closes the given database handle
 */
static void
smb_nic_dbclose(sqlite *db)
{
    if (db) {
        sqlite_close(db);
    }
}

static boolean_t
smb_nic_dbexists(void)
{
    return (access(SMB_NIC_DB_NAME, F_OK) == 0);
}

static boolean_t
smb_nic_dbvalidate(void)
{
    sqlite *db;
    char *errmsg = NULL;
    char *sql;
    char **result;
    int nrow, ncol;
    boolean_t check = B_TRUE;
    int rc;

    sql = sqlite_mprintf("SELECT * FROM db_info");
    if (sql == NULL)
        return (B_FALSE);

    db = smb_nic_dbopen(SMB_NIC_DB_ORW);
    if (db == NULL) {
        sqlite_freemem(sql);
        return (B_FALSE);
    }

    rc = sqlite_get_table(db, sql, &result, &nrow, &ncol, &errmsg);
    sqlite_freemem(sql);

    if (rc != SQLITE_OK) {
        syslog(LOG_ERR, "Failed to validate host database.  Unable " \
            "to get database information (%s).", NULL_MSGCHK(errmsg));
        sqlite_freemem(errmsg);
        smb_nic_dbclose(db);
        return (B_FALSE);
    }

    if (nrow != 1 || ncol != 3) {
        syslog(LOG_ERR, "Failed to validate host database:  bad " \
            "db_info table.");
        sqlite_free_table(result);
        smb_nic_dbclose(db);
        return (B_FALSE);
    }

    if ((atoi(result[3]) != SMB_NIC_DB_VERMAJOR) ||
        (atoi(result[4]) != SMB_NIC_DB_VERMINOR) ||
        (atoi(result[5]) != SMB_NIC_DB_MAGIC)) {
        syslog(LOG_ERR, "Failed to validate host database: bad " \
            "db_info content.");
        sqlite_free_table(result);
        smb_nic_dbclose(db);
        return (B_FALSE);
    }
    sqlite_free_table(result);

    sql = sqlite_mprintf("SELECT hostname FROM hosts");
    if (sql == NULL) {
        smb_nic_dbclose(db);
        return (B_FALSE);
    }

    rc = sqlite_get_table(db, sql, &result, &nrow, &ncol, &errmsg);
    sqlite_freemem(sql);

    if (rc != SQLITE_OK) {
        syslog(LOG_ERR, "Failed to validate host database.  Unable " \
        "to query for host (%s).", NULL_MSGCHK(errmsg));
        sqlite_freemem(errmsg);
        smb_nic_dbclose(db);
        return (B_FALSE);
    }

    sqlite_free_table(result);

    if (nrow == 0)
        /* No hosts in the database */
        check = B_FALSE;

    smb_nic_dbclose(db);
    return (check);
}

static int
smb_nic_dbaddhost(const char *host, const char *cmnt, char *if_list)
{
    sqlite *db;
    char *sql;
    char *errmsg;
    int rc, err = SMB_NIC_SUCCESS;

    sql = sqlite_mprintf("REPLACE INTO hosts (hostname, comment, ifnames)"
        "VALUES ('%s', '%q', '%s')", host, (cmnt) ? cmnt : "", if_list);
    if (sql == NULL)
        return (SMB_NIC_NO_MEMORY);

    db = smb_nic_dbopen(SMB_NIC_DB_ORW);
    if (db == NULL) {
        sqlite_freemem(sql);
        return (SMB_NIC_DBOPEN_FAILED);
    }

    rc = sqlite_exec(db, sql, NULL, NULL, &errmsg);
    sqlite_freemem(sql);
    smb_nic_dbclose(db);

    if (rc != SQLITE_OK) {
        syslog(LOG_ERR, "Failed to add host %s to host database (%s).",
            host, NULL_MSGCHK(errmsg));
        sqlite_freemem(errmsg);
        err = SMB_NIC_INSERT_FAILED;
    }

    return (err);
}

static int
smb_nic_dbdelhost(const char *host)
{
    sqlite *db;
    char *sql;
    char *errmsg;
    int rc, err = SMB_NIC_SUCCESS;

    sql = sqlite_mprintf("DELETE FROM hosts WHERE hostname = '%s'", host);
    if (sql == NULL)
        return (SMB_NIC_NO_MEMORY);

    db = smb_nic_dbopen(SMB_NIC_DB_ORW);
    if (db == NULL) {
        sqlite_freemem(sql);
        return (SMB_NIC_DBOPEN_FAILED);
    }

    rc = sqlite_exec(db, sql, NULL, NULL, &errmsg);
    sqlite_freemem(sql);
    smb_nic_dbclose(db);

    if (rc != SQLITE_OK) {
        syslog(LOG_ERR, "Failed to delete host %s from host " \
            "database (%s).", host, NULL_MSGCHK(errmsg));
        sqlite_freemem(errmsg);
        err = SMB_NIC_DELETE_FAILED;
    }

    return (err);
}

/*
 * smb_nic_dbsetinfo
 *
 * Initializes the db_info table upon database creation.
 */
static int
smb_nic_dbsetinfo(sqlite *db)
{
    char *errmsg = NULL;
    char *sql;
    int rc, err = SMB_NIC_SUCCESS;

    sql = sqlite_mprintf("INSERT INTO db_info (ver_major, ver_minor,"
        " magic) VALUES (%d, %d, %d)", SMB_NIC_DB_VERMAJOR,
        SMB_NIC_DB_VERMINOR, SMB_NIC_DB_MAGIC);

    if (sql == NULL)
        return (SMB_NIC_NO_MEMORY);

    rc = sqlite_exec(db, sql, NULL, NULL, &errmsg);
    sqlite_freemem(sql);
    if (rc != SQLITE_OK) {
        syslog(LOG_ERR, "Failed to add database information to " \
            "host database (%s).", NULL_MSGCHK(errmsg));
        sqlite_freemem(errmsg);
        err = SMB_NIC_DBINIT_ERROR;
    }

    return (err);
}

/*
 * smb_nic_nbt_get_exclude_list
 *
 * Construct an array containing list of i/f names on which NetBIOS traffic is
 * to be disabled, from a string containing a list of comma separated i/f names.
 *
 * Returns the number of i/f on which NetBIOS traffic is to be disabled.
 */
static int
smb_nic_nbt_get_exclude_list(char *excludestr, char **iflist, int max_nifs)
{
    int n = 0;
    char *entry;

    bzero(iflist, SMB_PI_MAX_NETWORKS * sizeof (char *));

    (void) trim_whitespace(excludestr);
    (void) strcanon(excludestr, ",");

    if (*excludestr == '\0')
        return (0);

    while (((iflist[n] = strsep(&excludestr, ",")) != NULL) &&
        (n < max_nifs)) {
        entry = iflist[n];
        if (*entry == '\0')
            continue;
        n++;
    }

    return (n);
}

/*
 * smb_nic_nbt_exclude
 *
 * Check to see if the given interface name should send NetBIOS traffic or not.
 *
 * Returns TRUE if NetBIOS traffic is disabled on an interface name.
 * Returns FALSE otherwise.
 */
static boolean_t
smb_nic_nbt_exclude(const smb_nic_t *nc, const char **exclude_list,
    int nexclude)
{
    char buf[INET6_ADDRSTRLEN];
    const char *ifname = nc->nic_ifname;
    int i;

    if (inet_ntop(AF_INET, &nc->nic_ip, buf, INET6_ADDRSTRLEN) == NULL)
        buf[0] = '\0';

    for (i = 0; i < nexclude; i++) {
        if (strcmp(ifname, exclude_list[i]) == 0)
            return (B_TRUE);

        if ((buf[0] != '\0') && (strcmp(buf, exclude_list[i]) == 0))
            return (B_TRUE);
    }

    return (B_FALSE);
}