libsmbns/common/smbns_netbios_name.c

	smbns_netbios_name.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.
 */

/*
 * NetBIOS name resolution node types.
 *
 * A B-node (broadcast node) uses broadcasts for name registration
 * and resolution.  Routers typically do not forward broadcasts and
 * only computers on the local subnet will respond.
 *
 * A P-node (peer-to-peer node) uses a NetBIOS name server (WINS)
 * to resolve NetBIOS names, which allows it to work across routers.
 * In order to function in a P-node environment, all computers must
 * be configured to use the NetBIOS name server because P-nodes do
 * not broadcast on the network.
 *
 * A mixed node (M-node) behaves as a B-node by default.  If it cannot
 * resolve the name via broadcast then it tries a NetBIOS name server
 * lookup (P-node).
 *
 * A hybrid node (H-node) behaves as a P-node by default.  If it cannot
 * resolve the name using a NetBIOS name server then it resorts to
 * broadcasts (B-node).
 *
 * NetBIOS Name Service Protocols
 *
 * A REQUEST packet is always sent to the well known UDP port 137.
 * The destination address is normally either the IP broadcast address or
 * the address of the NAME - the address of the NAME server it set up at
 * initialization time.  In rare cases, a request packet will be sent to
 * an end node, e.g.  a NAME QUERY REQUEST sent to "challenge" a node.
 *
 * A RESPONSE packet is always sent to the source UDP port and source IP
 * address of the request packet.
 *
 * A DEMAND packet must always be sent to the well known UDP port 137.
 * There is no restriction on the target IP address.
 *
 * A transaction ID is a value composed from the requestor's IP address and
 * a unique 16 bit value generated by the originator of the transaction.
 */

#include <unistd.h>
#include <syslog.h>
#include <stdlib.h>
#include <synch.h>
#include <errno.h>
#include <netdb.h>
#include <sys/socket.h>
#include <sys/sockio.h>
#include <arpa/inet.h>
#include <net/if_arp.h>

#include <smbsrv/libsmbns.h>
#include <smbns_netbios.h>

/*
 * RFC 1002 4.2.1.1.  HEADER
 */
#define QUESTION_TYPE_NETBIOS_GENERAL   0x20
#define QUESTION_TYPE_NETBIOS_STATUS    0x21

#define QUESTION_CLASS_INTERNET     0x0001

/*
 * RFC 1002 4.2.1.3.  RESOURCE RECORD
 */
#define RR_TYPE_IP_ADDRESS_RESOURCE 0x0001
#define RR_TYPE_NAME_SERVER_RESOURCE    0x0002
#define RR_TYPE_NULL_RESOURCE       0x000A
#define RR_TYPE_NETBIOS_RESOURCE    0x0020
#define RR_TYPE_NETBIOS_STATUS      0x0021

/*
 *
 * RESOURCE RECORD RR_CLASS field definitions
 */
#define RR_CLASS_INTERNET_CLASS     0x0001

/*
 * NB_FLAGS field of the RESOURCE RECORD RDATA field for RR_TYPE of NB.
 */
#define RR_FLAGS_NB_ONT_MASK        0x6000
#define RR_FLAGS_NB_ONT_B_NODE      0x0000
#define RR_FLAGS_NB_ONT_P_NODE      0x2000
#define RR_FLAGS_NB_ONT_M_NODE      0x4000
#define RR_FLAGS_NB_ONT_RESERVED    0x6000
#define RR_FLAGS_NB_GROUP_NAME      0x8000

#define NAME_FLAGS_PERMANENT_NAME   0x0200
#define NAME_FLAGS_ACTIVE_NAME      0x0400
#define NAME_FLAGS_CONFLICT     0x0800
#define NAME_FLAGS_DEREGISTER       0x1000
#define NAME_FLAGS_ONT_MASK     0x6000
#define NAME_FLAGS_ONT_B_NODE       0x0000
#define NAME_FLAGS_ONT_P_NODE       0x2000
#define NAME_FLAGS_ONT_M_NODE       0x4000
#define NAME_FLAGS_ONT_RESERVED     0x6000
#define NAME_FLAGS_GROUP_NAME       0x8000

#define MAX_NETBIOS_REPLY_DATA_SIZE 500

#define NAME_HEADER_SIZE        12

typedef struct nbt_name_reply {
    struct nbt_name_reply   *forw;
    struct nbt_name_reply   *back;
    struct name_packet  *packet;
    addr_entry_t        *addr;
    uint16_t        name_trn_id;
    boolean_t       reply_ready;
} nbt_name_reply_t;

static nbt_name_reply_t reply_queue;
static mutex_t rq_mtx;
static cond_t rq_cv;

static mutex_t nbt_name_config_mtx;

static name_queue_t delete_queue;
static name_queue_t refresh_queue;

static int name_sock = 0;

static int bcast_num = 0;
static int nbns_num = 0;
static addr_entry_t smb_bcast_list[SMB_PI_MAX_NETWORKS];
static addr_entry_t smb_nbns[SMB_PI_MAX_WINS];

static int smb_netbios_process_response(uint16_t, addr_entry_t *,
    struct name_packet *, uint32_t);

static int smb_send_name_service_packet(addr_entry_t *addr,
    struct name_packet *packet);

/*
 * Allocate a transaction id.
 */
static uint16_t
smb_netbios_name_trn_id(void)
{
    static uint16_t trn_id;
    static mutex_t trn_id_mtx;

    (void) mutex_lock(&trn_id_mtx);

    do {
        ++trn_id;
    } while (trn_id == 0 || trn_id == (uint16_t)-1);

    (void) mutex_unlock(&trn_id_mtx);
    return (trn_id);
}

static int
smb_end_node_challenge(nbt_name_reply_t *reply_info)
{
    int         rc;
    uint32_t        retry;
    uint16_t        tid;
    struct resource_record  *answer;
    struct name_question    question;
    addr_entry_t        *addr;
    struct name_entry   *destination;
    struct name_packet  packet;
    struct timespec     st;

    /*
     * The response packet has in it the address of the presumed owner
     * of the name.  Challenge that owner.  If owner either does not
     * respond or indicates that he no longer owns the name, claim the
     * name.  Otherwise, the name cannot be claimed.
     */

    if ((answer = reply_info->packet->answer) == 0)
        return (-1);

    destination = answer->name;
    question.name = answer->name;

    packet.info = NAME_QUERY_REQUEST | NM_FLAGS_UNICAST;
    packet.qdcount = 1; /* question entries */
    packet.question = &question;
    packet.ancount = 0; /* answer recs */
    packet.answer = NULL;
    packet.nscount = 0; /* authority recs */
    packet.authority = NULL;
    packet.arcount = 0; /* additional recs */
    packet.additional = NULL;

    addr = &destination->addr_list;
    for (retry = 0; retry < UCAST_REQ_RETRY_COUNT; retry++) {
        tid = smb_netbios_name_trn_id();
        packet.name_trn_id = tid;
        if (smb_send_name_service_packet(addr, &packet) >= 0) {
            if ((rc = smb_netbios_process_response(tid, addr,
                &packet, UCAST_REQ_RETRY_TIMEOUT)) != 0)
                return (rc);
        }
        st.tv_sec = 0;
        st.tv_nsec = (UCAST_REQ_RETRY_TIMEOUT * 1000000);
        (void) nanosleep(&st, 0);
    }
    /* No reply */
    return (0);
}

static nbt_name_reply_t *
smb_name_get_reply(uint16_t tid, uint32_t timeout)
{
    uint16_t        info;
    struct resource_record  *answer;
    nbt_name_reply_t    *reply;
    uint32_t        wait_time, to_save; /* in millisecond */
    struct timeval      wt;
    timestruc_t         to;

    to_save = timeout;
    reply = malloc(sizeof (nbt_name_reply_t));
    if (reply != NULL) {
        reply->reply_ready = B_FALSE;
        reply->name_trn_id = tid;
        (void) mutex_lock(&rq_mtx);
        QUEUE_INSERT_TAIL(&reply_queue, reply);
        (void) mutex_unlock(&rq_mtx);

        for (;;) {
            (void) gettimeofday(&wt, 0);
            wait_time = wt.tv_usec / 1000;

            to.tv_sec = 0;
            to.tv_nsec = timeout * 1000000;
            (void) mutex_lock(&rq_mtx);
            (void) cond_reltimedwait(&rq_cv, &rq_mtx, &to);
            (void) mutex_unlock(&rq_mtx);

            if (reply->reply_ready) {
                info = reply->packet->info;
                if (PACKET_TYPE(info) == WACK_RESPONSE) {
                    answer = reply->packet->answer;
                    wait_time = (answer) ?
                        TO_MILLISECONDS(answer->ttl) :
                        DEFAULT_TTL;
                    free(reply->addr);
                    free(reply->packet);
                    timeout = to_save + wait_time;
                    reply->reply_ready = B_FALSE;
                    reply->name_trn_id = tid;
                    (void) mutex_lock(&rq_mtx);
                    QUEUE_INSERT_TAIL(&reply_queue, reply);
                    (void) mutex_unlock(&rq_mtx);
                    continue;
                }
                return (reply);
            }
            (void) gettimeofday(&wt, 0);
            wait_time = (wt.tv_usec / 1000) - wait_time;
            if (wait_time >= timeout) {
                (void) mutex_lock(&rq_mtx);
                QUEUE_CLIP(reply);
                (void) mutex_unlock(&rq_mtx);
                free(reply);
                break;
            }
            timeout -= wait_time;
        }
    }

    return (0);
}

static void
smb_reply_ready(struct name_packet *packet, addr_entry_t *addr)
{
    nbt_name_reply_t *reply;
    struct resource_record *answer;

    (void) mutex_lock(&rq_mtx);
    for (reply = reply_queue.forw; reply != &reply_queue;
        reply = reply->forw) {
        if (reply->name_trn_id == packet->name_trn_id) {
            QUEUE_CLIP(reply);

            reply->addr = addr;
            reply->packet = packet;
            reply->reply_ready = B_TRUE;
            (void) cond_signal(&rq_cv);
            (void) mutex_unlock(&rq_mtx);
            return;
        }
    }
    (void) mutex_unlock(&rq_mtx);

    /* Presumably nobody is waiting any more... */
    free(addr);

    answer = packet->answer;
    if (answer)
        smb_netbios_name_freeaddrs(answer->name);
    free(packet);
}

static int
smb_netbios_process_response(uint16_t tid, addr_entry_t *addr,
    struct name_packet *packet, uint32_t timeout)
{
    int         rc = 0;
    uint16_t        info;
    nbt_name_reply_t    *reply;
    struct resource_record  *answer;
    struct name_entry   *name;
    struct name_entry   *entry;
    struct name_question    *question;
    uint32_t        ttl;

    if ((reply = smb_name_get_reply(tid, timeout)) == 0) {
        return (0); /* No reply: retry */
    }
    info = reply->packet->info;
    answer = reply->packet->answer;

    /* response */
    switch (PACKET_TYPE(info)) {
    case NAME_QUERY_RESPONSE:
        if (POSITIVE_RESPONSE(info)) {
            addr = &answer->name->addr_list;
            do {
                /*
                 * Make sure that remote name is not
                 * flagged local
                 */
                addr->attributes &= ~NAME_ATTR_LOCAL;

                if (answer->ttl)
                    addr->ttl = answer->ttl;
                else
                    addr->ttl = DEFAULT_TTL;
                addr->refresh_ttl = TO_SECONDS(addr->ttl);
                addr->ttl = addr->refresh_ttl;

                addr = addr->forw;
            } while (addr != &answer->name->addr_list);
            smb_netbios_name_logf(answer->name);
            (void) smb_netbios_cache_insert_list(answer->name);
            rc = 1;
        } else {
            rc = -1;
        }
        break;

    case NAME_REGISTRATION_RESPONSE:
        if (NEGATIVE_RESPONSE(info)) {
            if (RCODE(info) == RCODE_CFT_ERR) {
                if (answer == 0) {
                    rc = -RCODE(info);
                    break;
                }

                name = answer->name;
                entry = smb_netbios_cache_lookup(name);
                if (entry) {
                    /*
                     * a name in the state "conflict
                     * detected" does not "logically" exist
                     * on that node. No further session
                     * will be accepted on that name.
                     * No datagrams can be sent against
                     * that name.
                     * Such an entry will not be used for
                     * purposes of processing incoming
                     * request packets.
                     * The only valid user NetBIOS operation
                     * against such a name is DELETE NAME.
                     */
                    entry->attributes |= NAME_ATTR_CONFLICT;
                    syslog(LOG_DEBUG,
                        "nbns: name conflict: %15.15s",
                        entry->name);
                    smb_netbios_cache_unlock_entry(entry);
                }
            }
            rc = -RCODE(info);
            break;
        }

        /*
         * name can be added:
         *   adjust refresh timeout value,
         *   TTL, for this name
         */
        question = packet->question;
        ttl = (answer && answer->ttl) ? answer->ttl : DEFAULT_TTL;
        ttl = TO_SECONDS(ttl);
        if ((entry = smb_netbios_cache_lookup(question->name)) != 0) {
            addr = &entry->addr_list;
            do {
                if ((addr->refresh_ttl == 0) ||
                    (ttl < addr->refresh_ttl))
                    addr->refresh_ttl = addr->ttl = ttl;
                addr = addr->forw;
            } while (addr != &entry->addr_list);
            smb_netbios_cache_unlock_entry(entry);
        }

        rc = 1;
        break;

    case NAME_RELEASE_RESPONSE:
        rc = 1;
        break;

    case END_NODE_CHALLENGE_REGISTRATION_REQUEST:
        /*
         * The response packet has in it the
         * address of the presumed owner of the
         * name.  Challenge that owner.  If
         * owner either does not respond or
         * indicates that he no longer owns the
         * name, claim the name.  Otherwise,
         * the name cannot be claimed.
         */
        rc = smb_end_node_challenge(reply);
        break;

    default:
        rc = 0;
        break;
    }

    if (answer)
        smb_netbios_name_freeaddrs(answer->name);
    free(reply->addr);
    free(reply->packet);
    free(reply);
    return (rc);  /* retry */
}

/*
 * smb_name_buf_from_packet
 *
 * Description:
 *  Convert a NetBIOS Name Server Packet Block (npb)
 *  into the bits and bytes destined for the wire.
 *  The "buf" is used as a heap.
 *
 * Inputs:
 *  char *      buf -> Buffer, from the wire
 *  unsigned    n_buf   -> Length of 'buf'
 *  name_packet *npb    -> Packet block, decode into
 *  unsigned    n_npb   -> Max bytes in 'npb'
 *
 * Returns:
 *  >0  -> Encode successful, value is length of packet in "buf"
 *  -1  -> Hard error, can not possibly encode
 *  -2  -> Need more memory in buf -- it's too small
 */
static int
smb_name_buf_from_packet(unsigned char *buf, int n_buf,
    struct name_packet *npb)
{
    addr_entry_t        *raddr;
    unsigned char       *heap = buf;
    unsigned char       *end_heap = heap + n_buf;
    unsigned char       *dnptrs[32];
    unsigned char       comp_name_buf[MAX_NAME_LENGTH];
    unsigned int        tmp;
    int         i, step;

    if (n_buf < NAME_HEADER_SIZE)
        return (-1);        /* no header, impossible */

    dnptrs[0] = heap;
    dnptrs[1] = 0;

    BE_OUT16(heap, npb->name_trn_id);
    heap += 2;

    BE_OUT16(heap, npb->info);
    heap += 2;

    BE_OUT16(heap, npb->qdcount);
    heap += 2;

    BE_OUT16(heap, npb->ancount);
    heap += 2;

    BE_OUT16(heap, npb->nscount);
    heap += 2;

    BE_OUT16(heap, npb->arcount);
    heap += 2;

    for (i = 0; i < npb->qdcount; i++) {
        if ((heap + 34 + 4) > end_heap)
            return (-2);

        (void) smb_first_level_name_encode(npb->question[i].name,
            comp_name_buf, sizeof (comp_name_buf));
        (void) strcpy((char *)heap, (char *)comp_name_buf);
        heap += strlen((char *)comp_name_buf) + 1;

        BE_OUT16(heap, npb->question[i].question_type);
        heap += 2;

        BE_OUT16(heap, npb->question[i].question_class);
        heap += 2;
    }

    for (step = 1; step <= 3; step++) {
        struct resource_record *nrr;
        int n;

        /* truly ugly, but saves code copying */
        if (step == 1) {
            n = npb->ancount;
            nrr = npb->answer;
        } else if (step == 2) {
            n = npb->nscount;
            nrr = npb->authority;
        } else { /* step == 3 */
            n = npb->arcount;
            nrr = npb->additional;
        }

        for (i = 0; i < n; i++) {
            if ((heap + 34 + 10) > end_heap)
                return (-2);

            (void) smb_first_level_name_encode(nrr->name,
                comp_name_buf, sizeof (comp_name_buf));
            (void) strcpy((char *)heap, (char *)comp_name_buf);
            heap += strlen((char *)comp_name_buf) + 1;

            BE_OUT16(heap, nrr[i].rr_type);
            heap += 2;

            BE_OUT16(heap, nrr[i].rr_class);
            heap += 2;

            BE_OUT32(heap, nrr[i].ttl);
            heap += 4;

            BE_OUT16(heap, nrr[i].rdlength);
            heap += 2;

            if ((tmp = nrr[i].rdlength) > 0) {
                if ((heap + tmp) > end_heap)
                    return (-2);

                if (nrr[i].rr_type == NAME_RR_TYPE_NB &&
                    nrr[i].rr_class == NAME_RR_CLASS_IN &&
                    tmp >= 6 && nrr[i].rdata == 0) {
                    tmp = nrr[i].name->attributes &
                        (NAME_ATTR_GROUP |
                        NAME_ATTR_OWNER_NODE_TYPE);
                    BE_OUT16(heap, tmp);
                    heap += 2;

                    raddr = &nrr[i].name->addr_list;
                    (void) memcpy(heap,
                        &raddr->sin.sin_addr.s_addr,
                        sizeof (uint32_t));
                    heap += 4;
                } else {
                    bcopy(nrr[i].rdata, heap, tmp);
                    heap += tmp;
                }
            }
        }
    }
    return (heap - buf);
}

/*
 * strnchr
 *
 * Lookup for character 'c' in first 'n' chars of string 's'.
 * Returns pointer to the found char, otherwise returns 0.
 */
static char *
strnchr(const char *s, char c, int n)
{
    char *ps = (char *)s;
    char *es = (char *)s + n;

    while (ps < es && *ps) {
        if (*ps == c)
            return (ps);

        ++ps;
    }

    if (*ps == '\0' && c == '\0')
        return (ps);

    return (0);
}

static boolean_t
is_multihome(char *name)
{
    return (smb_nic_getnum(name) > 1);
}

/*
 * smb_netbios_getname
 *
 * Get the Netbios name part of the given record.
 * Does some boundary checks.
 *
 * Returns the name length on success, otherwise
 * returns 0.
 */
static int
smb_netbios_getname(char *name, char *buf, char *buf_end)
{
    char *name_end;
    int name_len;

    if (buf >= buf_end) {
        /* no room for a NB name */
        return (0);
    }

    name_end = strnchr(buf, '\0', buf_end - buf + 1);
    if (name_end == 0) {
        /* not a valid NB name */
        return (0);
    }

    name_len = name_end - buf + 1;

    (void) strlcpy(name, buf, name_len);
    return (name_len);
}

/*
 * smb_name_buf_to_packet
 *
 * Convert the bits and bytes that came from the wire into a NetBIOS
 * Name Server Packet Block (npb).  The "block" is used as a heap.
 *
 * Returns a pointer to a name packet on success.  Otherwise, returns
 * a NULL pointer.
 */
static struct name_packet *
smb_name_buf_to_packet(char *buf, int n_buf)
{
    struct name_packet *npb;
    unsigned char *heap;
    unsigned char *scan = (unsigned char *)buf;
    unsigned char *scan_end = scan + n_buf;
    char name_buf[MAX_NAME_LENGTH];
    struct resource_record *nrr = 0;
    int rc, i, n, nn, ns;
    uint16_t name_trn_id, info;
    uint16_t qdcount, ancount, nscount, arcount;
    addr_entry_t *next;
    int name_len;

    if (n_buf < NAME_HEADER_SIZE) {
        /* truncated header */
        syslog(LOG_DEBUG, "nbns: short packet (%d bytes)", n_buf);
        return (NULL);
    }

    name_trn_id = BE_IN16(scan); scan += 2;
    info = BE_IN16(scan); scan += 2;
    qdcount = BE_IN16(scan); scan += 2;
    ancount = BE_IN16(scan); scan += 2;
    nscount = BE_IN16(scan); scan += 2;
    arcount = BE_IN16(scan); scan += 2;

    ns = sizeof (struct name_entry);
    n = n_buf + sizeof (struct name_packet) +
        ((unsigned)qdcount * (sizeof (struct name_question) + ns)) +
        ((unsigned)ancount * (sizeof (struct resource_record) + ns)) +
        ((unsigned)nscount * (sizeof (struct resource_record) + ns)) +
        ((unsigned)arcount * (sizeof (struct resource_record) + ns));

    if ((npb = malloc(n)) == NULL)
        return (NULL);

    bzero(npb, n);
    heap = npb->block_data;
    npb->name_trn_id = name_trn_id;
    npb->info = info;
    npb->qdcount = qdcount;
    npb->ancount = ancount;
    npb->nscount = nscount;
    npb->arcount = arcount;

    /* scan is in position for question entries */

    /*
     * Measure the space needed for the tables
     */
    if (qdcount > 0) {
        /* LINTED - E_BAD_PTR_CAST_ALIGN */
        npb->question = (struct name_question *)heap;
        heap += qdcount * sizeof (struct name_question);
        for (i = 0; i < qdcount; i++) {
            /* LINTED - E_BAD_PTR_CAST_ALIGN */
            npb->question[i].name = (struct name_entry *)heap;
            heap += sizeof (struct name_entry);
        }
    }

    /* LINTED - E_BAD_PTR_CAST_ALIGN */
    nrr = (struct resource_record *)heap;

    if (ancount > 0) {
        /* LINTED - E_BAD_PTR_CAST_ALIGN */
        npb->answer = (struct resource_record *)heap;
        heap += ancount * sizeof (struct resource_record);
    }

    if (nscount > 0) {
        /* LINTED - E_BAD_PTR_CAST_ALIGN */
        npb->authority = (struct resource_record *)heap;
        heap += nscount * sizeof (struct resource_record);
    }

    if (arcount > 0) {
        /* LINTED - E_BAD_PTR_CAST_ALIGN */
        npb->additional = (struct resource_record *)heap;
        heap += arcount * sizeof (struct resource_record);
    }

    /*
     * Populate each resource_record's .name field.
     * Done as a second pass so that all resource records
     * (answer, authority, additional) are consecutive via nrr[i].
     */
    for (i = 0; i < (ancount + nscount + arcount); i++) {
        /* LINTED - E_BAD_PTR_CAST_ALIGN */
        nrr[i].name = (struct name_entry *)heap;
        heap += sizeof (struct name_entry);
    }


    for (i = 0; i < npb->qdcount; i++) {
        name_len = smb_netbios_getname(name_buf, (char *)scan,
            (char *)scan_end);
        if (name_len <= 0) {
            free(npb);
            return (NULL);
        }

        smb_init_name_struct(NETBIOS_EMPTY_NAME, 0, 0, 0, 0, 0, 0,
            npb->question[i].name);
        rc = smb_first_level_name_decode((unsigned char *)name_buf,
            npb->question[i].name);
        if (rc < 0) {
            /* Couldn't decode the question name */
            free(npb);
            return (NULL);
        }

        scan += name_len;
        if (scan + 4 > scan_end) {
            /* no room for Question Type(2) and Class(2) fields */
            free(npb);
            return (NULL);
        }

        npb->question[i].question_type = BE_IN16(scan); scan += 2;
        npb->question[i].question_class = BE_IN16(scan); scan += 2;
    }

    /*
     * Cheat. Remaining sections are of the same resource_record
     * format. Table space is consecutive.
     */

    for (i = 0; i < (ancount + nscount + arcount); i++) {
        if (scan[0] == 0xc0) {
            /* Namebuf is reused... */
            rc = 2;
        } else {
            name_len = smb_netbios_getname(name_buf, (char *)scan,
                (char *)scan_end);
            if (name_len <= 0) {
                free(npb);
                return (NULL);
            }
            rc = name_len;
        }
        scan += rc;

        if (scan + 10 > scan_end) {
            /*
             * no room for RR_TYPE (2), RR_CLASS (2), TTL (4) and
             * RDLENGTH (2) fields.
             */
            free(npb);
            return (NULL);
        }

        smb_init_name_struct(NETBIOS_EMPTY_NAME, 0, 0, 0, 0, 0, 0,
            nrr[i].name);
        if ((rc = smb_first_level_name_decode((unsigned char *)name_buf,
            nrr[i].name)) < 0) {
            free(npb);
            return (NULL);
        }

        nrr[i].rr_type = BE_IN16(scan); scan += 2;
        nrr[i].rr_class = BE_IN16(scan); scan += 2;
        nrr[i].ttl = BE_IN32(scan); scan += 4;
        nrr[i].rdlength = BE_IN16(scan); scan += 2;

        if ((n = nrr[i].rdlength) > 0) {
            if ((scan + n) > scan_end) {
                /* no room for RDATA */
                free(npb);
                return (NULL);
            }
            bcopy(scan, heap, n);

            nn = n;
            if (nrr[i].rr_type == 0x0020 &&
                nrr[i].rr_class == 0x01 && n >= 6) {
                while (nn) {
                    if (nn == 6)
                        next = &nrr[i].name->addr_list;
                    else {
                        next = malloc(
                            sizeof (addr_entry_t));
                        if (next == 0) {
                            /* not enough memory */
                            free(npb);
                            return (NULL);
                        }
                        QUEUE_INSERT_TAIL(
                            &nrr[i].name->addr_list,
                            next);
                    }
                    nrr[i].name->attributes =
                        BE_IN16(scan);
                    next->sin.sin_family = AF_INET;
                    next->sinlen = sizeof (next->sin);
                    (void) memcpy(
                        &next->sin.sin_addr.s_addr,
                        scan + 2, sizeof (uint32_t));
                    next->sin.sin_port =
                        htons(IPPORT_NETBIOS_DGM);
                    nn -= 6;
                    scan += 6;
                }
            } else {
                nrr[i].rdata = heap;
                scan += n;
            }
            heap += n;
        }
    }
    return (npb);
}

/*
 * smb_send_name_service_packet
 *
 * Description:
 *
 *  Send out a name service packet to proper destination.
 *
 * Inputs:
 *  struct netbios_name *dest   -> NETBIOS name of destination
 *  struct name_packet *packet  -> Packet to send
 *
 * Returns:
 *  success ->  >0
 *  failure -> <=0
 */
static int
smb_send_name_service_packet(addr_entry_t *addr, struct name_packet *packet)
{
    unsigned char buf[MAX_DATAGRAM_LENGTH];
    int len;

    if ((len = smb_name_buf_from_packet(buf, sizeof (buf), packet)) < 0) {
        errno = EINVAL;
        return (-1);
    }

    return (sendto(name_sock, buf, len, MSG_EOR,
        (struct sockaddr *)&addr->sin, addr->sinlen));
}

/*
 * smb_netbios_send_rcv
 *
 * This function sends the given NetBIOS packet to the given
 * address and get back the response. If send operation is not
 * successful, it's repeated 'retries' times.
 *
 * Returns:
 *      0       Unsuccessful send operation; no reply
 *      1       Got reply
 */
static int
smb_netbios_send_rcv(int bcast, addr_entry_t *destination,
    struct name_packet *packet, uint32_t retries, uint32_t timeout)
{
    uint32_t retry;
    uint16_t    tid;
    struct timespec st;
    int rc;

    for (retry = 0; retry < retries; retry++) {
        if ((destination->flags & ADDR_FLAG_VALID) == 0)
            return (0);

        tid = smb_netbios_name_trn_id();
        packet->name_trn_id = tid;
        if (smb_send_name_service_packet(destination, packet) >= 0) {
            rc = smb_netbios_process_response(tid, destination,
                packet, timeout);

            if ((rc > 0) || (bcast == BROADCAST))
                return (1);

            if (rc != 0)
                return (0);
        }

        st.tv_sec = 0;
        st.tv_nsec = (timeout * 1000000);
        (void) nanosleep(&st, 0);
    }

    return (0);
}

/*
 * RFC 1002 4.2.2.  NAME REGISTRATION REQUEST
 */
static int
smb_send_name_registration_request(int bcast, struct name_question *question,
    struct resource_record *additional)
{
    int gotreply = 0;
    uint32_t retries;
    uint32_t timeout;
    addr_entry_t *destination;
    struct name_packet packet;
    unsigned char type;
    int i, addr_num, rc;

    type = question->name->name[15];
    if ((type != NBT_WKSTA) && (type != NBT_SERVER)) {
        syslog(LOG_DEBUG, "nbns: name registration bad type (0x%02x)",
            type);
        smb_netbios_name_logf(question->name);
        question->name->attributes &= ~NAME_ATTR_LOCAL;
        return (-1);
    }

    if (bcast == BROADCAST) {
        if (bcast_num == 0)
            return (0);
        destination = smb_bcast_list;
        addr_num = bcast_num;
        retries = BCAST_REQ_RETRY_COUNT;
        timeout = BCAST_REQ_RETRY_TIMEOUT;
        packet.info = NAME_REGISTRATION_REQUEST | NM_FLAGS_BROADCAST;
    } else {
        if (nbns_num == 0)
            return (0);
        destination = smb_nbns;
        addr_num = nbns_num;
        retries = UCAST_REQ_RETRY_COUNT;
        timeout = UCAST_REQ_RETRY_TIMEOUT;
        packet.info = NAME_REGISTRATION_REQUEST | NM_FLAGS_UNICAST;
    }

    packet.qdcount = 1; /* question entries */
    packet.question = question;
    packet.ancount = 0; /* answer recs */
    packet.answer = NULL;
    packet.nscount = 0; /* authority recs */
    packet.authority = NULL;
    packet.arcount = 1; /* additional recs */
    packet.additional = additional;

    if (IS_UNIQUE(question->name->attributes) &&
        (is_multihome((char *)(question->name->name))))
        packet.info |= NAME_MULTIHOME_REGISTRATION_REQUEST;

    for (i = 0; i < addr_num; i++) {
        /*
         * Only register with the Primary WINS server,
         * unless we got no reply.
         */
        if ((bcast == UNICAST) && gotreply)
            break;

        rc = smb_netbios_send_rcv(bcast, &destination[i], &packet,
            retries, timeout);
        if (rc == 1)
            gotreply = 1;
    }

    return (gotreply);
}

/*
 * RFC 1002 4.2.4.  NAME REFRESH REQUEST
 */
/*ARGSUSED*/
static int
smb_send_name_refresh_request(int bcast, struct name_question *question,
    struct resource_record *additional, int force)
{
    int rc = 0;
    int gotreply = 0;
    uint32_t retries;
    uint32_t timeout;
    addr_entry_t *addr;
    addr_entry_t *destination;
    struct name_packet packet;
    unsigned char type;
    int i, addr_num, q_addrs = 0;

    type = question->name->name[15];
    if ((type != NBT_WKSTA) && (type != NBT_SERVER)) {
        syslog(LOG_DEBUG, "nbns: name refresh bad type (0x%02x)", type);
        smb_netbios_name_logf(question->name);
        question->name->attributes &= ~NAME_ATTR_LOCAL;
        return (-1);
    }
    switch (bcast) {
    case BROADCAST :
        if (bcast_num == 0)
            return (-1);
        destination = smb_bcast_list;
        addr_num = bcast_num;
        retries = BCAST_REQ_RETRY_COUNT;
        timeout = BCAST_REQ_RETRY_TIMEOUT;
        packet.info = NAME_REFRESH_REQUEST | NM_FLAGS_BROADCAST;
        break;

    case UNICAST :
        if (nbns_num == 0)
            return (-1);
        destination = smb_nbns;
        addr_num = nbns_num;
        retries = UCAST_REQ_RETRY_COUNT;
        timeout = UCAST_REQ_RETRY_TIMEOUT;
        packet.info = NAME_REFRESH_REQUEST | NM_FLAGS_UNICAST;
        break;

    default:
        destination = &question->name->addr_list;
        /*
         * the value of addr_num is irrelvant here, because
         * the code is going to do special_process so it doesn't
         * need the addr_num. We set a value here just to avoid
         * compiler warning.
         */
        addr_num = 0;
        retries = UCAST_REQ_RETRY_COUNT;
        timeout = UCAST_REQ_RETRY_TIMEOUT;
        packet.info = NAME_REFRESH_REQUEST | NM_FLAGS_UNICAST;
        q_addrs = 1;
        break;
    }

    if (IS_UNIQUE(question->name->attributes) &&
        (is_multihome((char *)(question->name->name))))
        packet.info |= NAME_MULTIHOME_REGISTRATION_REQUEST;

    packet.qdcount = 1; /* question entries */
    packet.question = question;
    packet.ancount = 0; /* answer recs */
    packet.answer = NULL;
    packet.nscount = 0; /* authority recs */
    packet.authority = NULL;
    packet.arcount = 1; /* additional recs */
    packet.additional = additional;

    if (q_addrs)
        goto special_process;

    for (i = 0; i < addr_num; i++) {
        rc = smb_netbios_send_rcv(bcast, &destination[i], &packet,
            retries, timeout);
        if (rc == 1)
            gotreply = 1;
    }

    return (gotreply);

special_process:
    addr = destination;
    do {
        rc = smb_netbios_send_rcv(bcast, addr, &packet,
            retries, timeout);
        if (rc == 1)
            gotreply = 1;
        addr = addr->forw;
    } while (addr != destination);

    return (gotreply);
}

/*
 * RFC 1002 4.2.5.  POSITIVE NAME REGISTRATION RESPONSE
 * RFC 1002 4.2.6.  NEGATIVE NAME REGISTRATION RESPONSE
 */
static int
smb_send_name_registration_response(addr_entry_t *addr,
    struct name_packet *original_packet, uint16_t rcode)
{
    struct name_packet  packet;
    struct resource_record  answer;

    bzero(&packet, sizeof (struct name_packet));
    bzero(&answer, sizeof (struct resource_record));

    packet.name_trn_id = original_packet->name_trn_id;
    packet.info = NAME_REGISTRATION_RESPONSE | NAME_NM_FLAGS_RA |
        (rcode & NAME_RCODE_MASK);
    packet.qdcount = 0; /* question entries */
    packet.question = NULL;
    packet.ancount = 1; /* answer recs */
    packet.answer = &answer;
    packet.nscount = 0; /* authority recs */
    packet.authority = NULL;
    packet.arcount = 0; /* additional recs */
    packet.additional = NULL;

    answer.name = original_packet->question->name;
    answer.rr_type = NAME_QUESTION_TYPE_NB;
    answer.rr_class = NAME_QUESTION_CLASS_IN;
    answer.ttl = original_packet->additional->ttl;
    answer.rdlength = original_packet->additional->rdlength;
    answer.rdata = original_packet->additional->rdata;

    return (smb_send_name_service_packet(addr, &packet));
}

/*
 * RFC 1002 4.2.9.  NAME RELEASE REQUEST & DEMAND
 */
static int
smb_send_name_release_request_and_demand(int bcast,
    struct name_question *question, struct resource_record *additional)
{
    int gotreply = 0;
    int i, rc;
    int addr_num;
    uint32_t retries;
    uint32_t timeout;
    addr_entry_t *destination;
    struct name_packet packet;

    if (bcast == BROADCAST) {
        if (bcast_num == 0)
            return (-1);
        destination = smb_bcast_list;
        addr_num = bcast_num;
        retries = 1; /* BCAST_REQ_RETRY_COUNT */
        timeout = 100; /* BCAST_REQ_RETRY_TIMEOUT */
        packet.info = NAME_RELEASE_REQUEST | NM_FLAGS_BROADCAST;
    } else {
        if (nbns_num == 0)
            return (-1);
        destination = smb_nbns;
        addr_num = nbns_num;
        retries = 1; /* UCAST_REQ_RETRY_COUNT */
        timeout = 100; /* UCAST_REQ_RETRY_TIMEOUT */
        packet.info = NAME_RELEASE_REQUEST | NM_FLAGS_UNICAST;
    }

    packet.qdcount = 1; /* question entries */
    packet.question = question;
    packet.ancount = 0; /* answer recs */
    packet.answer = NULL;
    packet.nscount = 0; /* authority recs */
    packet.authority = NULL;
    packet.arcount = 1; /* additional recs */
    packet.additional = additional;

    for (i = 0; i < addr_num; i++) {
        rc = smb_netbios_send_rcv(bcast, &destination[i], &packet,
            retries, timeout);
        if (rc == 1)
            gotreply = 1;
    }

    return (gotreply);
}

/*
 * RFC 1002 4.2.10.  POSITIVE NAME RELEASE RESPONSE
 * RFC 1002 4.2.11.  NEGATIVE NAME RELEASE RESPONSE
 */
static int
/* LINTED - E_STATIC_UNUSED */
smb_send_name_release_response(addr_entry_t *addr,
    struct name_packet *original_packet, uint16_t rcode)
{
    struct name_packet  packet;
    struct resource_record  answer;

    bzero(&packet, sizeof (struct name_packet));
    bzero(&answer, sizeof (struct resource_record));

    packet.name_trn_id = original_packet->name_trn_id;
    packet.info = NAME_RELEASE_RESPONSE | (rcode & NAME_RCODE_MASK);
    packet.qdcount = 0; /* question entries */
    packet.question = NULL;
    packet.ancount = 1; /* answer recs */
    packet.answer = &answer;
    packet.nscount = 0; /* authority recs */
    packet.authority = NULL;
    packet.arcount = 0; /* additional recs */
    packet.additional = NULL;

    answer.name = original_packet->question->name;
    answer.rr_type = NAME_QUESTION_TYPE_NB;
    answer.rr_class = NAME_QUESTION_CLASS_IN;
    answer.ttl = original_packet->additional->ttl;
    answer.rdlength = original_packet->additional->rdlength;
    answer.rdata = original_packet->additional->rdata;

    return (smb_send_name_service_packet(addr, &packet));
}

/*
 * RFC 1002 4.2.12.  NAME QUERY REQUEST
 */
static int
smb_send_name_query_request(int bcast, struct name_question *question)
{
    int         rc = 0;
    uint32_t        retry, retries;
    uint32_t        timeout;
    uint16_t        tid;
    addr_entry_t        *destination;
    struct name_packet  packet;
    int             i, addr_num;
    struct timespec     st;

    if (bcast == BROADCAST) {
        if (bcast_num == 0)
            return (-1);
        destination = smb_bcast_list;
        addr_num = bcast_num;
        retries = BCAST_REQ_RETRY_COUNT;
        timeout = BCAST_REQ_RETRY_TIMEOUT;
        packet.info = NAME_QUERY_REQUEST | NM_FLAGS_BROADCAST;
    } else {
        if (nbns_num == 0)
            return (-1);
        destination = smb_nbns;
        addr_num = nbns_num;
        retries = UCAST_REQ_RETRY_COUNT;
        timeout = UCAST_REQ_RETRY_TIMEOUT;
        packet.info = NAME_QUERY_REQUEST | NM_FLAGS_UNICAST;
    }
    packet.qdcount = 1; /* question entries */
    packet.question = question;
    packet.ancount = 0; /* answer recs */
    packet.answer = NULL;
    packet.nscount = 0; /* authority recs */
    packet.authority = NULL;
    packet.arcount = 0; /* additional recs */
    packet.additional = NULL;

    for (i = 0; i < addr_num; i++) {
        for (retry = 0; retry < retries; retry++) {
            if ((destination[i].flags & ADDR_FLAG_VALID) == 0)
                break;
            tid = smb_netbios_name_trn_id();
            packet.name_trn_id = tid;

            if (smb_send_name_service_packet(&destination[i],
                &packet) >= 0) {
                if ((rc = smb_netbios_process_response(tid,
                    &destination[i],
                    &packet, timeout)) != 0)
                    break;
            }
            st.tv_sec = 0;
            st.tv_nsec = (timeout * 1000000);
            (void) nanosleep(&st, 0);
        }
    }

    return (rc);
}

/*
 * RFC 1002 4.2.13.  POSITIVE NAME QUERY RESPONSE
 * RFC 1002 4.2.14.  NEGATIVE NAME QUERY RESPONSE
 */
static int
smb_send_name_query_response(addr_entry_t *addr,
    struct name_packet *original_packet, struct name_entry *entry,
    uint16_t rcode)
{
    addr_entry_t        *raddr;
    struct name_packet  packet;
    struct resource_record  answer;
    uint16_t        attr;
    unsigned char       data[MAX_DATAGRAM_LENGTH];
    unsigned char       *scan = data;
    uint32_t        ret_addr;

    packet.name_trn_id = original_packet->name_trn_id;
    packet.info = NAME_QUERY_RESPONSE | (rcode & NAME_RCODE_MASK);
    packet.qdcount = 0; /* question entries */
    packet.question = NULL;
    packet.ancount = 1; /* answer recs */
    packet.answer = &answer;
    packet.nscount = 0; /* authority recs */
    packet.authority = NULL;
    packet.arcount = 0; /* additional recs */
    packet.additional = NULL;

    answer.name = entry;
    answer.rr_class = NAME_QUESTION_CLASS_IN;
    answer.ttl = entry->addr_list.ttl;
    answer.rdata = data;
    if (rcode) {
        answer.rr_type = NAME_RR_TYPE_NULL;
        answer.rdlength = 0;
        bzero(data, 6);
    } else {
        answer.rdlength = 0;
        answer.rr_type = NAME_QUESTION_TYPE_NB;
        raddr = &entry->addr_list;
        scan = data;
        do {
            attr = entry->attributes & (NAME_ATTR_GROUP |
                NAME_ATTR_OWNER_NODE_TYPE);

            BE_OUT16(scan, attr); scan += 2;
            ret_addr = LE_32(raddr->sin.sin_addr.s_addr);
            *scan++ = ret_addr;
            *scan++ = ret_addr >> 8;
            *scan++ = ret_addr >> 16;
            *scan++ = ret_addr >> 24;

            answer.rdlength += 6;
            raddr = raddr->forw;
        } while (raddr != &entry->addr_list);
    }

    return (smb_send_name_service_packet(addr, &packet));
}

/*
 * RFC 1002 4.2.18.  NODE STATUS RESPONSE
 */
static int
smb_send_node_status_response(addr_entry_t *addr,
    struct name_packet *original_packet)
{
    uint32_t        net_ipaddr;
    int64_t         max_connections;
    struct arpreq       arpreq;
    struct name_packet  packet;
    struct resource_record  answer;
    unsigned char       *scan;
    unsigned char       *scan_end;
    unsigned char       data[MAX_NETBIOS_REPLY_DATA_SIZE];
    boolean_t scan_done = B_FALSE;
    smb_inaddr_t ipaddr;

    bzero(&packet, sizeof (struct name_packet));
    bzero(&answer, sizeof (struct resource_record));

    packet.name_trn_id = original_packet->name_trn_id;
    packet.info = NODE_STATUS_RESPONSE;
    packet.qdcount = 0; /* question entries */
    packet.question = NULL;
    packet.ancount = 1; /* answer recs */
    packet.answer = &answer;
    packet.nscount = 0; /* authority recs */
    packet.authority = NULL;
    packet.arcount = 0; /* additional recs */
    packet.additional = NULL;

    answer.name = original_packet->question->name;
    answer.rr_type = NAME_RR_TYPE_NBSTAT;
    answer.rr_class = NAME_QUESTION_CLASS_IN;
    answer.ttl = 0;
    answer.rdata = data;

    scan = smb_netbios_cache_status(data, MAX_NETBIOS_REPLY_DATA_SIZE,
        original_packet->question->name->scope);

    scan_end = data + MAX_NETBIOS_REPLY_DATA_SIZE;

    ipaddr.a_ipv4 = addr->sin.sin_addr.s_addr;
    ipaddr.a_family = AF_INET;
    if (smb_nic_is_same_subnet(&ipaddr))
        net_ipaddr = addr->sin.sin_addr.s_addr;
    else
        net_ipaddr = 0;

    (void) smb_config_getnum(SMB_CI_MAX_CONNECTIONS, &max_connections);

    while (!scan_done) {
        if ((scan + 6) >= scan_end) {
            packet.info |= NAME_NM_FLAGS_TC;
            break;
        }

        if (net_ipaddr != 0) {
            struct sockaddr_in *s_in;
            int s;

            s = socket(AF_INET, SOCK_DGRAM, 0);
            /* LINTED - E_BAD_PTR_CAST_ALIGN */
            s_in = (struct sockaddr_in *)&arpreq.arp_pa;
            s_in->sin_family = AF_INET;
            s_in->sin_addr.s_addr = net_ipaddr;
            if (ioctl(s, SIOCGARP, (caddr_t)&arpreq) < 0) {
                bzero(scan, 6);
            } else {
                bcopy(&arpreq.arp_ha.sa_data, scan, 6);
            }
            (void) close(s);
        } else {
            bzero(scan, 6);
        }
        scan += 6;

        if ((scan + 26) >= scan_end) {
            packet.info |= NAME_NM_FLAGS_TC;
            break;
        }
        bzero(scan, 26);
        scan += 26;

        if ((scan + 2) >= scan_end) {
            packet.info |= NAME_NM_FLAGS_TC;
            break;
        }
        BE_OUT16(scan, 0); scan += 2;

        if ((scan + 2) >= scan_end) {
            packet.info |= NAME_NM_FLAGS_TC;
            break;
        }
        BE_OUT16(scan, 0); scan += 2;

        if ((scan + 2) >= scan_end) {
            packet.info |= NAME_NM_FLAGS_TC;
            break;
        }
        BE_OUT16(scan, 0); scan += 2;

        if ((scan + 2) >= scan_end) {
            packet.info |= NAME_NM_FLAGS_TC;
            break;
        }
        BE_OUT16(scan, 0); scan += 2;

        if ((scan + 2) >= scan_end) {
            packet.info |= NAME_NM_FLAGS_TC;
            break;
        }
        BE_OUT16(scan, 0); scan += 2;

        if ((scan + 2) >= scan_end) {
            packet.info |= NAME_NM_FLAGS_TC;
            break;
        }
        BE_OUT16(scan, 0); scan += 2;

        if ((scan + 2) >= scan_end) {
            packet.info |= NAME_NM_FLAGS_TC;
            break;
        }
        BE_OUT16(scan, 0); scan += 2;

        if ((scan + 2) >= scan_end) {
            packet.info |= NAME_NM_FLAGS_TC;
            break;
        }
        BE_OUT16(scan, max_connections); scan += 2;

        if ((scan + 2) >= scan_end) {
            packet.info |= NAME_NM_FLAGS_TC;
            break;
        }

        BE_OUT16(scan, 0); scan += 2;

        scan_done = B_TRUE;
    }
    answer.rdlength = scan - data;
    return (smb_send_name_service_packet(addr, &packet));
}

static int
smb_name_Bnode_add_name(struct name_entry *name)
{
    struct name_question        question;
    struct resource_record      additional;
    unsigned char           data[8];
    uint16_t            attr;
    addr_entry_t            *addr;
    int rc = 0;

    addr = &name->addr_list;

    do {
        /* build name service packet */
        question.name = name;
        /*
         * question.name->attributes |= NAME_NB_FLAGS_ONT_B;
         * This is commented because NAME_NB_FLAGS_ONT_B is 0
         */
        question.question_type = NAME_QUESTION_TYPE_NB;
        question.question_class = NAME_QUESTION_CLASS_IN;

        additional.name = name;
        additional.rr_class = NAME_QUESTION_CLASS_IN;
        additional.ttl = 0;
        additional.rdata = data;
        additional.rdlength = 6;
        additional.rr_type = NAME_QUESTION_TYPE_NB;
        attr = name->attributes & (NAME_ATTR_GROUP |
            NAME_ATTR_OWNER_NODE_TYPE);

        BE_OUT16(&data[0], attr);
        (void) memcpy(&data[2], &addr->sin.sin_addr.s_addr,
            sizeof (uint32_t));

        rc |= smb_send_name_registration_request(BROADCAST, &question,
            &additional);
        addr = addr->forw;

    } while (addr != &name->addr_list);

    return (rc);
}

static int
smb_name_Bnode_find_name(struct name_entry *name)
{
    struct name_question    question;

    question.name = name;
    question.question_type = NAME_QUESTION_TYPE_NB;
    question.question_class = NAME_QUESTION_CLASS_IN;

    return (smb_send_name_query_request(BROADCAST, &question));
}

static int
smb_name_Bnode_delete_name(struct name_entry *name)
{
    struct name_question    question;
    struct resource_record  additional;
    addr_entry_t        *raddr;
    unsigned char       data[MAX_DATAGRAM_LENGTH];
    unsigned char       *scan = data;
    uint32_t        attr;
    uint32_t        ret_addr;

    /* build packet */
    question.name = name;
    question.question_type = NAME_QUESTION_TYPE_NB;
    question.question_class = NAME_QUESTION_CLASS_IN;

    additional.name = name;
    additional.rr_class = NAME_QUESTION_CLASS_IN;
    additional.ttl = 0;
    additional.rdata = data;
    additional.rdlength = 0;
    additional.rr_type = NAME_QUESTION_TYPE_NB;
    raddr = &name->addr_list;
    scan = data;
    do {
        attr = name->attributes & (NAME_ATTR_GROUP |
            NAME_ATTR_OWNER_NODE_TYPE);

        BE_OUT16(scan, attr); scan += 2;
        ret_addr = LE_32(raddr->sin.sin_addr.s_addr);
        *scan++ = ret_addr;
        *scan++ = ret_addr >> 8;
        *scan++ = ret_addr >> 16;
        *scan++ = ret_addr >> 24;

        additional.rdlength += 6;
    } while (raddr != &name->addr_list);

    return (smb_send_name_release_request_and_demand(BROADCAST,
        &question, &additional));
}

static int
smb_name_Pnode_add_name(struct name_entry *name)
{
    struct name_question        question;
    struct resource_record      additional;
    unsigned char           data[8];
    uint16_t            attr;
    addr_entry_t            *addr;
    int rc = 0;

    /* build packet */
    addr = &name->addr_list;
    do {
        question.name = name;
        question.question_type = NAME_QUESTION_TYPE_NB;
        question.question_class = NAME_QUESTION_CLASS_IN;

        additional.name = name;
        additional.rr_class = NAME_QUESTION_CLASS_IN;
        additional.ttl = 0;
        additional.rdata = data;
        additional.rdlength = 6;
        additional.rr_type = NAME_QUESTION_TYPE_NB;
        attr = name->attributes &
            (NAME_ATTR_GROUP | NAME_ATTR_OWNER_NODE_TYPE);

        BE_OUT16(&data[0], attr);
        (void) memcpy(&data[2], &addr->sin.sin_addr.s_addr,
            sizeof (uint32_t));

        rc |= smb_send_name_registration_request(UNICAST, &question,
            &additional);

        addr = addr->forw;

    } while (addr != &name->addr_list);

    return (rc);
}

static int
smb_name_Pnode_refresh_name(struct name_entry *name)
{
    struct name_question        question;
    struct resource_record      additional;
    unsigned char           data[8];
    uint16_t            attr;
    addr_entry_t            *addr;
    int rc = 0;

    /* build packet */
    addr = &name->addr_list;
    do {
        question.name = name;
        question.question_type = NAME_QUESTION_TYPE_NB;
        question.question_class = NAME_QUESTION_CLASS_IN;

        additional.name = name;
        additional.rr_class = NAME_QUESTION_CLASS_IN;
        additional.ttl = 0;
        additional.rdata = data;
        additional.rdlength = 6;
        additional.rr_type = NAME_QUESTION_TYPE_NB;
        attr = name->attributes &
            (NAME_ATTR_GROUP | NAME_ATTR_OWNER_NODE_TYPE);

        BE_OUT16(&data[0], attr);
        (void) memcpy(&data[2], &addr->sin.sin_addr.s_addr,
            sizeof (uint32_t));

        rc |= smb_send_name_refresh_request(UNICAST, &question,
            &additional, 1);

        addr = addr->forw;
    } while (addr != &name->addr_list);

    return (rc);
}

static int
smb_name_Pnode_find_name(struct name_entry *name)
{
    struct name_question    question;

    /*
     * Host initiated processing for a P node
     */
    question.name = name;
    question.name->attributes |= NAME_NB_FLAGS_ONT_P;
    question.question_type = NAME_QUESTION_TYPE_NB;
    question.question_class = NAME_QUESTION_CLASS_IN;

    return (smb_send_name_query_request(UNICAST, &question));
}

static int
smb_name_Pnode_delete_name(struct name_entry *name)
{
    struct name_question    question;
    struct resource_record  additional;
    addr_entry_t        *raddr;
    unsigned char       data[MAX_DATAGRAM_LENGTH];
    unsigned char       *scan = data;
    uint32_t        attr;
    uint32_t        ret_addr;

    /* build packet */
    question.name = name;
    question.name->attributes |= NAME_NB_FLAGS_ONT_P;
    question.question_type = NAME_QUESTION_TYPE_NB;
    question.question_class = NAME_QUESTION_CLASS_IN;

    additional.name = name;
    additional.rr_class = NAME_QUESTION_CLASS_IN;
    additional.ttl = 0;
    additional.rdata = data;
    additional.rdlength = 0;
    additional.rr_type = NAME_QUESTION_TYPE_NB;
    raddr = &name->addr_list;
    do {
        scan = data;
        attr = name->attributes & (NAME_ATTR_GROUP |
            NAME_ATTR_OWNER_NODE_TYPE);

        BE_OUT16(scan, attr); scan += 2;
        ret_addr = LE_32(raddr->sin.sin_addr.s_addr);
        *scan++ = ret_addr;
        *scan++ = ret_addr >> 8;
        *scan++ = ret_addr >> 16;
        *scan++ = ret_addr >> 24;

        additional.rdlength = 6;
        raddr = raddr->forw;
        (void) smb_send_name_release_request_and_demand(UNICAST,
            &question, &additional);
    } while (raddr != &name->addr_list);

    return (1);
}

static int
smb_name_Mnode_add_name(struct name_entry *name)
{
    if (smb_name_Bnode_add_name(name) > 0) {
        if (nbns_num == 0)
            return (1); /* No name server configured */

        return (smb_name_Pnode_add_name(name));
    }
    return (-1);
}

static int
smb_name_Hnode_add_name(struct name_entry *name)
{
    if (nbns_num > 0) {
        if (smb_name_Pnode_add_name(name) == 1)
            return (1);
    }

    return (smb_name_Bnode_add_name(name));
}

static int
smb_name_Mnode_find_name(struct name_entry *name)
{
    if (smb_name_Bnode_find_name(name) == 1)
        return (1);

    if (nbns_num == 0)
        return (1); /* No name server configured */

    return (smb_name_Pnode_find_name(name));
}

static int
smb_name_Hnode_find_name(struct name_entry *name)
{
    if (nbns_num > 0)
        if (smb_name_Pnode_find_name(name) == 1)
            return (1);

    return (smb_name_Bnode_find_name(name));
}

static int
smb_name_Mnode_delete_name(struct name_entry *name)
{
    (void) smb_name_Bnode_delete_name(name);

    if (nbns_num == 0)
        return (-1); /* No name server configured */

    if (smb_name_Pnode_delete_name(name) > 0)
        return (1);

    return (-1);
}

static int
smb_name_Hnode_delete_name(struct name_entry *name)
{
    if (nbns_num > 0)
        if (smb_name_Pnode_delete_name(name) > 0)
            return (1);

    return (smb_name_Bnode_delete_name(name));
}

static void
smb_name_process_Bnode_packet(struct name_packet *packet, addr_entry_t *addr)
{
    struct name_entry   *name;
    struct name_entry   *entry;
    struct name_question    *question;
    struct resource_record  *additional;

    question = packet->question;
    additional = packet->additional;

    switch (packet->info & NAME_OPCODE_OPCODE_MASK) {
    case NAME_OPCODE_REFRESH:
        /* Guard against malformed packets */
        if ((question == 0) || (additional == 0))
            break;
        if (additional->name->addr_list.sin.sin_addr.s_addr == 0)
            break;

        name = question->name;
        name->addr_list.ttl = additional->ttl;
        name->attributes = additional->name->attributes;
        name->addr_list.sin = additional->name->addr_list.sin;
        name->addr_list.forw = name->addr_list.back = &name->addr_list;

        if ((entry = smb_netbios_cache_lookup_addr(name)) != 0) {
            smb_netbios_cache_update_entry(entry, question->name);
            smb_netbios_cache_unlock_entry(entry);
        }
        else
            (void) smb_netbios_cache_insert(question->name);
        break;

    case NAME_OPCODE_QUERY:
        /*
         * This opcode covers both NAME_QUERY_REQUEST and
         * NODE_STATUS_REQUEST. They can be distinguished
         * based on the type of question entry.
         */

        /* All query requests have to have question entry */
        if (question == 0)
            break;

        if (question->question_type == NAME_QUESTION_TYPE_NB) {
            name = question->name;
            if ((entry = smb_netbios_cache_lookup(name)) != 0) {
                (void) smb_send_name_query_response(addr,
                    packet, entry, 0);
                smb_netbios_cache_unlock_entry(entry);
            }
        }
        else
        if (question->question_type == NAME_QUESTION_TYPE_NBSTAT) {
            /*
             * Name of "*" may be used to force node to
             * divulge status for administrative purposes
             */
            name = question->name;
            entry = 0;
            if (NETBIOS_NAME_IS_STAR(name->name) ||
                ((entry = smb_netbios_cache_lookup(name)) != 0)) {
                if (entry)
                    smb_netbios_cache_unlock_entry(entry);
                /*
                 * send only those names that are
                 * in the same scope as the scope
                 * field in the request packet
                 */
                (void) smb_send_node_status_response(addr,
                    packet);
            }
        }
        break;

    default:
        break;
    }
}

static void
smb_name_process_Pnode_packet(struct name_packet *packet, addr_entry_t *addr)
{
    struct name_entry   *name;
    struct name_entry   *entry;
    struct name_question    *question;
    struct resource_record  *additional;

    question = packet->question;
    additional = packet->additional;

    if (packet->info & NAME_NM_FLAGS_B) {
        /*
         * always ignore UDP broadcast packets
         */
        return;
    }

    switch (packet->info & NAME_OPCODE_OPCODE_MASK) {
    case NAME_OPCODE_REFRESH:
        /* Guard against malformed packets */
        if ((question == 0) || (additional == 0))
            break;
        if (additional->name->addr_list.sin.sin_addr.s_addr == 0)
            break;

        name = question->name;
        name->addr_list.ttl = additional->ttl;
        name->attributes = additional->name->attributes;
        name->addr_list.sin = additional->name->addr_list.sin;
        name->addr_list.forw = name->addr_list.back = &name->addr_list;

        if ((entry = smb_netbios_cache_lookup(name)) != 0) {
            smb_netbios_cache_update_entry(entry, name);
            smb_netbios_cache_unlock_entry(entry);
        }
        else
            (void) smb_netbios_cache_insert(name);

        (void) smb_send_name_registration_response(addr, packet, 0);
        break;

    case NAME_OPCODE_QUERY:
        /*
         * This opcode covers both NAME_QUERY_REQUEST and
         * NODE_STATUS_REQUEST. They can be distinguished
         * based on the type of question entry.
         */

        /* All query requests have to have question entry */
        if (question == 0)
            break;

        if (question->question_type == NAME_QUESTION_TYPE_NB) {
            name = question->name;
            if ((entry = smb_netbios_cache_lookup(name)) != 0) {
                /*
                 * send response to the IP address and port
                 * number from which the request was received.
                 */
                (void) smb_send_name_query_response(addr,
                    packet, entry, 0);
                smb_netbios_cache_unlock_entry(entry);
            } else {
                /*
                 * send response to the requestor
                 */
                (void) smb_send_name_query_response(addr,
                    packet, name, RCODE_NAM_ERR);
            }
        }
        else
        if (question->question_type == NAME_QUESTION_TYPE_NBSTAT) {
            /*
             * Name of "*" may be used to force node to
             * divulge status for administrative purposes
             */
            name = question->name;
            entry = 0;
            if (NETBIOS_NAME_IS_STAR(name->name) ||
                ((entry = smb_netbios_cache_lookup(name)) != 0)) {
                /*
                 * send only those names that are
                 * in the same scope as the scope
                 * field in the request packet
                 */
                if (entry)
                    smb_netbios_cache_unlock_entry(entry);
                (void) smb_send_node_status_response(addr,
                    packet);
            }
        }
        break;

    default:
        break;
    }
}

static void
smb_name_process_Mnode_packet(struct name_packet *packet, addr_entry_t *addr)
{
    if (packet->info & NAME_NM_FLAGS_B)
        smb_name_process_Bnode_packet(packet, addr);
    else
        smb_name_process_Pnode_packet(packet, addr);
}

static void
smb_name_process_Hnode_packet(struct name_packet *packet, addr_entry_t *addr)
{
    if (packet->info & NAME_NM_FLAGS_B)
        smb_name_process_Bnode_packet(packet, addr);
    else
        smb_name_process_Pnode_packet(packet, addr);
}


/*
 * smb_netbios_name_tick
 *
 * Called once a second to handle name server timeouts.
 */
void
smb_netbios_name_tick(void)
{
    struct name_entry *name;
    struct name_entry *entry;

    (void) mutex_lock(&refresh_queue.mtx);
    smb_netbios_cache_refresh(&refresh_queue);

    while ((name = refresh_queue.head.forw) != &refresh_queue.head) {
        QUEUE_CLIP(name);
        if (IS_LOCAL(name->attributes)) {
            if (IS_UNIQUE(name->attributes)) {
                (void) smb_name_Pnode_refresh_name(name);
            }
        } else {
            entry = smb_name_find_name(name);
            smb_name_unlock_name(entry);
        }
        free(name);
    }
    (void) mutex_unlock(&refresh_queue.mtx);

    smb_netbios_cache_reset_ttl();
}

/*
 * smb_name_find_name
 *
 * Lookup name cache for the given name.
 * If it's not in the cache it'll send a
 * name query request and then lookup the
 * cache again. Note that if a name is
 * returned it's locked and called MUST
 * unlock it by calling smb_name_unlock_name()
 */
struct name_entry *
smb_name_find_name(struct name_entry *name)
{
    struct name_entry *result;

    if ((result = smb_netbios_cache_lookup(name)) == 0) {
        switch (smb_node_type) {
        case 'B':
            (void) smb_name_Bnode_find_name(name);
            break;
        case 'P':
            (void) smb_name_Pnode_find_name(name);
            break;
        case 'M':
            (void) smb_name_Mnode_find_name(name);
            break;
        case 'H':
        default:
            (void) smb_name_Hnode_find_name(name);
            break;
        }
        return (smb_netbios_cache_lookup(name));
    }

    return (result);
}

void
smb_name_unlock_name(struct name_entry *name)
{
    smb_netbios_cache_unlock_entry(name);
}

int
smb_name_add_name(struct name_entry *name)
{
    int         rc = 1;

    smb_netbios_name_logf(name);

    switch (smb_node_type) {
    case 'B':
        rc = smb_name_Bnode_add_name(name);
        break;
    case 'P':
        rc = smb_name_Pnode_add_name(name);
        break;
    case 'M':
        rc = smb_name_Mnode_add_name(name);
        break;
    case 'H':
    default:
        rc = smb_name_Hnode_add_name(name);
        break;
    }

    if (rc >= 0)
        (void) smb_netbios_cache_insert(name);

    return (rc);
}

int
smb_name_delete_name(struct name_entry *name)
{
    int         rc;
    unsigned char type;

    type = name->name[15];
    if ((type != NBT_WKSTA) && (type != NBT_SERVER)) {
        syslog(LOG_DEBUG, "nbns: name delete bad type (0x%02x)", type);
        smb_netbios_name_logf(name);
        name->attributes &= ~NAME_ATTR_LOCAL;
        return (-1);
    }

    smb_netbios_cache_delete(name);

    switch (smb_node_type) {
    case 'B':
        rc = smb_name_Bnode_delete_name(name);
        break;
    case 'P':
        rc = smb_name_Pnode_delete_name(name);
        break;
    case 'M':
        rc = smb_name_Mnode_delete_name(name);
        break;
    case 'H':
    default:
        rc = smb_name_Hnode_delete_name(name);
        break;
    }

    if (rc > 0)
        return (0);

    return (-1);
}

typedef struct {
    addr_entry_t *addr;
    char *buf;
    int length;
} worker_param_t;

/*
 * smb_netbios_worker
 *
 * Process incoming request/response packets for Netbios
 * name service (on port 138).
 */
void *
smb_netbios_worker(void *arg)
{
    worker_param_t *p = (worker_param_t *)arg;
    addr_entry_t *addr = p->addr;
    struct name_packet *packet;

    if ((packet = smb_name_buf_to_packet(p->buf, p->length)) != NULL) {
        if (packet->info & NAME_OPCODE_R) {
            /* Reply packet */
            smb_reply_ready(packet, addr);
            free(p->buf);
            free(p);
            return (NULL);
        }

        /* Request packet */
        switch (smb_node_type) {
        case 'B':
            smb_name_process_Bnode_packet(packet, addr);
            break;
        case 'P':
            smb_name_process_Pnode_packet(packet, addr);
            break;
        case 'M':
            smb_name_process_Mnode_packet(packet, addr);
            break;
        case 'H':
        default:
            smb_name_process_Hnode_packet(packet, addr);
            break;
        }

        if (packet->answer)
            smb_netbios_name_freeaddrs(packet->answer->name);
        free(packet);
    } else {
        syslog(LOG_ERR, "nbns: packet decode failed");
    }

    free(addr);
    free(p->buf);
    free(p);
    return (NULL);
}

/*
 * Configure the node type.  If a WINS server has been specified,
 * act like an H-node.  Otherwise, behave like a B-node.
 */
static void
smb_netbios_node_config(void)
{
    static smb_cfg_id_t wins[SMB_PI_MAX_WINS] = {
        SMB_CI_WINS_SRV1,
        SMB_CI_WINS_SRV2
    };
    char        ipstr[16];
    uint32_t    ipaddr;
    int     i;

    smb_node_type = SMB_NODETYPE_B;
    nbns_num = 0;
    bzero(smb_nbns, sizeof (addr_entry_t) * SMB_PI_MAX_WINS);

    for (i = 0; i < SMB_PI_MAX_WINS; ++i) {
        ipstr[0] = '\0';
        (void) smb_config_getstr(wins[i], ipstr, sizeof (ipstr));

        if ((ipaddr = inet_addr(ipstr)) == INADDR_NONE)
            continue;

        smb_node_type = SMB_NODETYPE_H;
        smb_nbns[nbns_num].flags = ADDR_FLAG_VALID;
        smb_nbns[nbns_num].sinlen = sizeof (struct sockaddr_in);
        smb_nbns[nbns_num].sin.sin_family = AF_INET;
        smb_nbns[nbns_num].sin.sin_addr.s_addr = ipaddr;
        smb_nbns[nbns_num].sin.sin_port = htons(IPPORT_NETBIOS_NS);
        nbns_num++;
    }
}

static void
smb_netbios_name_registration(void)
{
    nbcache_iter_t nbc_iter;
    struct name_entry *name;
    int rc;

    rc = smb_netbios_cache_getfirst(&nbc_iter);
    while (rc == 0) {
        name = nbc_iter.nbc_entry;
        (void) smb_netbios_name_logf(name);
        if (IS_UNIQUE(name->attributes) && IS_LOCAL(name->attributes)) {
            switch (smb_node_type) {
            case SMB_NODETYPE_B:
                (void) smb_name_Bnode_add_name(name);
                break;
            case SMB_NODETYPE_P:
                (void) smb_name_Pnode_add_name(name);
                break;
            case SMB_NODETYPE_M:
                (void) smb_name_Mnode_add_name(name);
                break;
            case SMB_NODETYPE_H:
            default:
                (void) smb_name_Hnode_add_name(name);
                break;
            }
        }
        free(name);
        rc = smb_netbios_cache_getnext(&nbc_iter);
    }
}

/*
 * Note that the node configuration must be setup before calling
 * smb_init_name_struct().
 */
void
smb_netbios_name_config(void)
{
    addr_entry_t        *bcast_entry;
    struct name_entry   name;
    smb_niciter_t       ni;
    int         rc;

    (void) mutex_lock(&nbt_name_config_mtx);
    smb_netbios_node_config();

    bcast_num = 0;
    bzero(smb_bcast_list, sizeof (addr_entry_t) * SMB_PI_MAX_NETWORKS);

    rc = smb_nic_getfirst(&ni);
    while (rc == SMB_NIC_SUCCESS) {
        if ((ni.ni_nic.nic_smbflags & SMB_NICF_NBEXCL) ||
            (ni.ni_nic.nic_smbflags & SMB_NICF_ALIAS)) {
            rc = smb_nic_getnext(&ni);
            continue;
        }

        bcast_entry = &smb_bcast_list[bcast_num];
        bcast_entry->flags = ADDR_FLAG_VALID;
        bcast_entry->attributes = NAME_ATTR_LOCAL;
        bcast_entry->sinlen = sizeof (struct sockaddr_in);
        bcast_entry->sin.sin_family = AF_INET;
        bcast_entry->sin.sin_port = htons(IPPORT_NETBIOS_NS);
        bcast_entry->sin.sin_addr.s_addr = ni.ni_nic.nic_bcast;
        bcast_num++;

        smb_init_name_struct((unsigned char *)ni.ni_nic.nic_host,
            NBT_WKSTA, 0, ni.ni_nic.nic_ip.a_ipv4,
            htons(IPPORT_NETBIOS_DGM),
            NAME_ATTR_UNIQUE, NAME_ATTR_LOCAL, &name);
        (void) smb_netbios_cache_insert(&name);

        smb_init_name_struct((unsigned char *)ni.ni_nic.nic_host,
            NBT_SERVER, 0, ni.ni_nic.nic_ip.a_ipv4,
            htons(IPPORT_NETBIOS_DGM),
            NAME_ATTR_UNIQUE, NAME_ATTR_LOCAL, &name);
        (void) smb_netbios_cache_insert(&name);

        rc = smb_nic_getnext(&ni);
    }

    smb_netbios_name_registration();
    (void) mutex_unlock(&nbt_name_config_mtx);
}

void
smb_netbios_name_unconfig(void)
{
    struct name_entry *name;

    (void) mutex_lock(&nbt_name_config_mtx);
    (void) mutex_lock(&delete_queue.mtx);
    smb_netbios_cache_delete_locals(&delete_queue);

    while ((name = delete_queue.head.forw) != &delete_queue.head) {
        QUEUE_CLIP(name);
        (void) smb_name_delete_name(name);
        free(name);
    }
    (void) mutex_unlock(&delete_queue.mtx);
    (void) mutex_unlock(&nbt_name_config_mtx);
}

void
smb_netbios_name_reconfig(void)
{
    smb_netbios_name_unconfig();
    smb_netbios_name_config();
}

/*
 * NetBIOS Name Service (port 137)
 */
/*ARGSUSED*/
void *
smb_netbios_name_service(void *arg)
{
    struct sockaddr_in  sin;
    addr_entry_t        *addr;
    int         len;
    int         flag = 1;
    char            *buf;
    worker_param_t      *worker_param;
    smb_inaddr_t        ipaddr;

    /*
     * Initialize reply_queue
     */
    bzero(&reply_queue, sizeof (reply_queue));
    reply_queue.forw = reply_queue.back = &reply_queue;

    if ((name_sock = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
        syslog(LOG_ERR, "nbns: socket failed: %m");
        smb_netbios_event(NETBIOS_EVENT_ERROR);
        return (NULL);
    }

    flag = 1;
    (void) setsockopt(name_sock, SOL_SOCKET, SO_REUSEADDR, &flag,
        sizeof (flag));
    flag = 1;
    (void) setsockopt(name_sock, SOL_SOCKET, SO_BROADCAST, &flag,
        sizeof (flag));

    bzero(&sin, sizeof (struct sockaddr_in));
    sin.sin_family = AF_INET;
    sin.sin_port = htons(IPPORT_NETBIOS_NS);
    if (bind(name_sock, (struct sockaddr *)&sin, sizeof (sin)) != 0) {
        syslog(LOG_ERR, "nbns: bind(%d) failed: %m",
            IPPORT_NETBIOS_NS);
        (void) close(name_sock);
        smb_netbios_event(NETBIOS_EVENT_ERROR);
        return (NULL);
    }

    smb_netbios_event(NETBIOS_EVENT_NS_START);

    while (smb_netbios_running()) {
        buf = malloc(MAX_DATAGRAM_LENGTH);
        addr = malloc(sizeof (addr_entry_t));
        if ((buf == NULL) || (addr == NULL)) {
            /* Sleep for 10 seconds and try again */
            free(addr);
            free(buf);
            smb_netbios_sleep(10);
            continue;
        }
ignore:     bzero(addr, sizeof (addr_entry_t));
        addr->sinlen = sizeof (addr->sin);
        addr->forw = addr->back = addr;

        if ((len = recvfrom(name_sock, buf, MAX_DATAGRAM_LENGTH,
            0, (struct sockaddr *)&addr->sin, &addr->sinlen)) < 0) {
            if (errno == ENOMEM || errno == ENFILE ||
                errno == EMFILE) {
                /* Sleep for 10 seconds and try again */
                free(buf);
                free(addr);
                smb_netbios_sleep(10);
                continue;
            }
            syslog(LOG_ERR, "nbns: recvfrom failed: %m");
            free(buf);
            free(addr);
            smb_netbios_event(NETBIOS_EVENT_ERROR);
            goto shutdown;
        }

        /* Ignore any incoming packets from myself... */

        ipaddr.a_ipv4 = addr->sin.sin_addr.s_addr;
        ipaddr.a_family = AF_INET;
        if (smb_nic_is_local(&ipaddr))
            goto ignore;

        /*
         * Launch a netbios worker to process the received packet.
         */
        worker_param = malloc(sizeof (worker_param_t));
        if (worker_param) {
            pthread_t worker;
            pthread_attr_t tattr;

            worker_param->addr = addr;
            worker_param->buf = buf;
            worker_param->length = len;

            (void) pthread_attr_init(&tattr);
            (void) pthread_attr_setdetachstate(&tattr,
                PTHREAD_CREATE_DETACHED);
            (void) pthread_create(&worker, &tattr,
                smb_netbios_worker, worker_param);
            (void) pthread_attr_destroy(&tattr);
        }
    }

shutdown:
    smb_netbios_event(NETBIOS_EVENT_NS_STOP);
    smb_netbios_wait(NETBIOS_EVENT_BROWSER_STOP);

    if (!smb_netbios_error())
        smb_netbios_name_unconfig();

    (void) close(name_sock);
    return (NULL);
}