source: vendor/current/source3/nmbd/nmbd_incomingdgrams.c

/* 
   Unix SMB/CIFS implementation.
   NBT netbios routines and daemon - version 2
   Copyright (C) Andrew Tridgell 1994-1998
   Copyright (C) Luke Kenneth Casson Leighton 1994-1998
   Copyright (C) Jeremy Allison 1994-1998
   
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.
   
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
   
   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
   
*/

#include "includes.h"
#include "../librpc/gen_ndr/svcctl.h"
#include "nmbd/nmbd.h"

extern bool found_lm_clients;

#if 0

/* XXXX note: This function is currently unsuitable for use, as it
   does not properly check that a server is in a fit state to become
   a backup browser before asking it to be one.
   The code is left here to be worked on at a later date.
*/

/****************************************************************************
Tell a server to become a backup browser
**************************************************************************/

void tell_become_backup(void)
{
  struct subnet_record *subrec;
  for (subrec = FIRST_SUBNET; subrec; subrec = NEXT_SUBNET_EXCLUDING_UNICAST(subrec))
  {
    struct work_record *work;
    for (work = subrec->workgrouplist; work; work = work->next)
    {
      struct server_record *servrec;
      int num_servers = 0;
      int num_backups = 0;
          
      for (servrec = work->serverlist; servrec; servrec = servrec->next)
      {
        num_servers++;
              
        if (is_myname(servrec->serv.name))
          continue;
              
        if (servrec->serv.type & SV_TYPE_BACKUP_BROWSER) 
        {
          num_backups++;
          continue;
        }
              
        if (servrec->serv.type & SV_TYPE_MASTER_BROWSER)
          continue;
              
        if (!(servrec->serv.type & SV_TYPE_POTENTIAL_BROWSER))
          continue;
              
        DEBUG(3,("num servers: %d num backups: %d\n", 
              num_servers, num_backups));
              
        /* make first server a backup server. thereafter make every
           tenth server a backup server */
        if (num_backups != 0 && (num_servers+9) / num_backups > 10)
          continue;
              
        DEBUG(2,("sending become backup to %s %s for %s\n",
             servrec->serv.name, inet_ntoa(subrec->bcast_ip),
             work->work_group));
              
        /* type 11 request from MYNAME(20) to WG(1e) for SERVER */
        do_announce_request(servrec->serv.name, work->work_group,
              ANN_BecomeBackup, 0x20, 0x1e, subrec->bcast_ip);
      }
    }
  }
}
#endif

/*******************************************************************
  Process an incoming host announcement packet.
*******************************************************************/

void process_host_announce(struct subnet_record *subrec, struct packet_struct *p, const char *buf)
{
        struct dgram_packet *dgram = &p->packet.dgram;
        int ttl = IVAL(buf,1)/1000;
        unstring announce_name;
        uint32_t servertype = IVAL(buf,23);
        fstring comment;
        struct work_record *work;
        struct server_record *servrec;
        unstring work_name;
        unstring source_name;
        ZERO_STRUCT(source_name);
        ZERO_STRUCT(announce_name);

        pull_ascii_fstring(comment, buf+31);
  
        pull_ascii_nstring(announce_name, sizeof(announce_name), buf+5);
        pull_ascii_nstring(source_name, sizeof(source_name), dgram->source_name.name);

        DEBUG(3,("process_host_announce: from %s<%02x> IP %s to \
%s for server %s.\n", source_name, source_name[15], inet_ntoa(p->ip),
                        nmb_namestr(&dgram->dest_name),announce_name));

        DEBUG(5,("process_host_announce: ttl=%d server type=%08x comment=%s\n",
                ttl, servertype,comment));

        /* Filter servertype to remove impossible bits. */
        servertype &= ~(SV_TYPE_LOCAL_LIST_ONLY|SV_TYPE_DOMAIN_ENUM);

        /* A host announcement must be sent to the name WORKGROUP<1d>. */
        if(dgram->dest_name.name_type != 0x1d) {
                DEBUG(2,("process_host_announce: incorrect name type for destination from IP %s \
(was %02x) should be 0x1d. Allowing packet anyway.\n",
                        inet_ntoa(p->ip), dgram->dest_name.name_type));
                /* Change it so it was. */
                dgram->dest_name.name_type = 0x1d;
        }

        /* For a host announce the workgroup name is the destination name. */
        pull_ascii_nstring(work_name, sizeof(work_name), dgram->dest_name.name);

        /*
         * Syntax servers version 5.1 send HostAnnounce packets to
         * *THE WRONG NAME*. They send to LOCAL_MASTER_BROWSER_NAME<00>
         * instead of WORKGROUP<1d> name. So to fix this we check if
         * the workgroup name is our own name, and if so change it
         * to be our primary workgroup name.
         */

        if(strequal(work_name, lp_netbios_name()))
                unstrcpy(work_name,lp_workgroup());

        /*
         * We are being very agressive here in adding a workgroup
         * name on the basis of a host announcing itself as being
         * in that workgroup. Maybe we should wait for the workgroup
         * announce instead ? JRA.
         */

        work = find_workgroup_on_subnet(subrec, work_name);

        if(servertype != 0) {
                if (work ==NULL ) {
                        /* We have no record of this workgroup. Add it. */
                        if((work = create_workgroup_on_subnet(subrec, work_name, ttl))==NULL)
                                goto done;
                }
  
                if((servrec = find_server_in_workgroup( work, announce_name))==NULL) {
                        /* If this server is not already in the workgroup, add it. */
                        create_server_on_workgroup(work, announce_name, 
                                servertype|SV_TYPE_LOCAL_LIST_ONLY, 
                                ttl, comment);
                } else {
                        /* Update the record. */
                        servrec->serv.type = servertype|SV_TYPE_LOCAL_LIST_ONLY;
                        update_server_ttl( servrec, ttl);
                        strlcpy(servrec->serv.comment,comment,sizeof(servrec->serv.comment));
                }
        } else {
                /*
                 * This server is announcing it is going down. Remove it from the 
                 * workgroup.
                 */
                if(!is_myname(announce_name) && (work != NULL) &&
                                ((servrec = find_server_in_workgroup( work, announce_name))!=NULL)) {
                        remove_server_from_workgroup( work, servrec);
                }
        }

        subrec->work_changed = True;
done:
        return;
}

/*******************************************************************
  Process an incoming WORKGROUP announcement packet.
*******************************************************************/

void process_workgroup_announce(struct subnet_record *subrec, struct packet_struct *p, const char *buf)
{
        struct dgram_packet *dgram = &p->packet.dgram;
        int ttl = IVAL(buf,1)/1000;
        unstring workgroup_announce_name;
        unstring master_name;
        uint32_t servertype = IVAL(buf,23);
        struct work_record *work;
        unstring source_name;
        unstring dest_name;

        pull_ascii_nstring(workgroup_announce_name,sizeof(workgroup_announce_name),buf+5);
        pull_ascii_nstring(master_name,sizeof(master_name),buf+31);
        pull_ascii_nstring(source_name,sizeof(source_name),dgram->source_name.name);
        pull_ascii_nstring(dest_name,sizeof(dest_name),dgram->dest_name.name);

        DEBUG(3,("process_workgroup_announce: from %s<%02x> IP %s to \
%s for workgroup %s.\n", source_name, source_name[15], inet_ntoa(p->ip),
                        nmb_namestr(&dgram->dest_name),workgroup_announce_name));

        DEBUG(5,("process_workgroup_announce: ttl=%d server type=%08x master browser=%s\n",
                ttl, servertype, master_name));

        /* Workgroup announcements must only go to the MSBROWSE name. */
        if (!strequal(dest_name, MSBROWSE) || (dgram->dest_name.name_type != 0x1)) {
                DEBUG(0,("process_workgroup_announce: from IP %s should be to __MSBROWSE__<0x01> not %s\n",
                        inet_ntoa(p->ip), nmb_namestr(&dgram->dest_name)));
                goto done;
        }

        if ((work = find_workgroup_on_subnet(subrec, workgroup_announce_name))==NULL) {
                /* We have no record of this workgroup. Add it. */
                if((work = create_workgroup_on_subnet(subrec, workgroup_announce_name, ttl))==NULL)
                        goto done;
        } else {
                /* Update the workgroup death_time. */
                update_workgroup_ttl(work, ttl);
        }

        if(*work->local_master_browser_name == '\0') {
                /* Set the master browser name. */
                set_workgroup_local_master_browser_name( work, master_name );
        }

        subrec->work_changed = True;

done:
        return;
}

/*******************************************************************
  Process an incoming local master browser announcement packet.
*******************************************************************/

void process_local_master_announce(struct subnet_record *subrec, struct packet_struct *p, const char *buf)
{
        struct dgram_packet *dgram = &p->packet.dgram;
        int ttl = IVAL(buf,1)/1000;
        unstring server_name;
        uint32_t servertype = IVAL(buf,23);
        fstring comment;
        unstring work_name;
        struct work_record *work = NULL;
        struct server_record *servrec;
        unstring source_name;

        pull_ascii_nstring(server_name,sizeof(server_name),buf+5);
        pull_ascii_fstring(comment, buf+31);
        pull_ascii_nstring(source_name, sizeof(source_name), dgram->source_name.name);
        pull_ascii_nstring(work_name, sizeof(work_name), dgram->dest_name.name);

        DEBUG(3,("process_local_master_announce: from %s<%02x> IP %s to \
%s for server %s.\n", source_name, source_name[15], inet_ntoa(p->ip),
                nmb_namestr(&dgram->dest_name),server_name));

        DEBUG(5,("process_local_master_announce: ttl=%d server type=%08x comment=%s\n",
                ttl, servertype, comment));

        /* A local master announcement must be sent to the name WORKGROUP<1e>. */
        if(dgram->dest_name.name_type != 0x1e) {
                DEBUG(0,("process_local_master_announce: incorrect name type for destination from IP %s \
(was %02x) should be 0x1e. Ignoring packet.\n",
                        inet_ntoa(p->ip), dgram->dest_name.name_type));
                goto done;
        }

        /* Filter servertype to remove impossible bits. */
        servertype &= ~(SV_TYPE_LOCAL_LIST_ONLY|SV_TYPE_DOMAIN_ENUM);

        /* For a local master announce the workgroup name is the destination name. */

        if ((work = find_workgroup_on_subnet(subrec, work_name))==NULL) {
                /* Don't bother adding if it's a local master release announce. */
                if(servertype == 0)
                        goto done;

                /* We have no record of this workgroup. Add it. */
                if((work = create_workgroup_on_subnet(subrec, work_name, ttl))==NULL)
                        goto done;
        }

        /* If we think we're the local master browser for this workgroup,
                we should never have got this packet. We don't see our own
                packets.
        */
        if(AM_LOCAL_MASTER_BROWSER(work)) {
                DEBUG(0,("process_local_master_announce: Server %s at IP %s is announcing itself as \
a local master browser for workgroup %s and we think we are master. Forcing election.\n",
                        server_name, inet_ntoa(p->ip), work_name));

                /* Samba nmbd versions 1.9.17 to 1.9.17p4 have a bug in that when
                 they have become a local master browser once, they will never
                 stop sending local master announcements. To fix this we send
                 them a reset browser packet, with level 0x2 on the __SAMBA__
                 name that only they should be listening to. */
   
                send_browser_reset( 0x2, "__SAMBA__" , 0x20, p->ip);

                /* We should demote ourself and force an election. */

                unbecome_local_master_browser( subrec, work, True);

                /* The actual election requests are handled in nmbd_election.c */
                goto done;
        }  

        /* Find the server record on this workgroup. If it doesn't exist, add it. */

        if(servertype != 0) {
                if((servrec = find_server_in_workgroup( work, server_name))==NULL) {
                        /* If this server is not already in the workgroup, add it. */
                        create_server_on_workgroup(work, server_name, 
                                servertype|SV_TYPE_LOCAL_LIST_ONLY, 
                                ttl, comment);
                } else {
                        /* Update the record. */
                        if (servrec->serv.type !=
                                        (servertype|SV_TYPE_LOCAL_LIST_ONLY)) {
                                servrec->serv.type =
                                        servertype|SV_TYPE_LOCAL_LIST_ONLY;
                                subrec->work_changed = true;
                        }
                        if (!strequal(servrec->serv.comment,comment)) {
                                strlcpy(servrec->serv.comment,
                                        comment,
                                        sizeof(servrec->serv.comment));
                                subrec->work_changed = true;
                        }
                        update_server_ttl(servrec, ttl);
                }

                if (!strequal(work->local_master_browser_name, server_name)) {
                        set_workgroup_local_master_browser_name( work, server_name );
                        subrec->work_changed = true;
                }
        } else {
                /*
                 * This server is announcing it is going down. Remove it from the
                 * workgroup.
                 */
                if(!is_myname(server_name) &&
                                ((servrec = find_server_in_workgroup( work, server_name))!=NULL)) {
                        remove_server_from_workgroup( work, servrec);
                }
        }

done:
        return;
}

/*******************************************************************
  Process a domain master announcement frame.
  Domain master browsers receive these from local masters. The Domain
  master should then issue a sync with the local master, asking for
  that machines local server list.
******************************************************************/

void process_master_browser_announce(struct subnet_record *subrec, 
                                     struct packet_struct *p,const char *buf)
{
        unstring local_master_name;
        struct work_record *work;
        struct browse_cache_record *browrec;

        pull_ascii_nstring(local_master_name,sizeof(local_master_name),buf);
  
        DEBUG(3,("process_master_browser_announce: Local master announce from %s IP %s.\n",
                local_master_name, inet_ntoa(p->ip)));
  
        if (!lp_domain_master()) {
                DEBUG(0,("process_master_browser_announce: Not configured as domain \
master - ignoring master announce.\n"));
                goto done;
        }
  
        if((work = find_workgroup_on_subnet(subrec, lp_workgroup())) == NULL) {
                DEBUG(0,("process_master_browser_announce: Cannot find workgroup %s on subnet %s\n",
                        lp_workgroup(), subrec->subnet_name));
                goto done;
        }

        if(!AM_DOMAIN_MASTER_BROWSER(work)) {
                DEBUG(0,("process_master_browser_announce: Local master announce made to us from \
%s IP %s and we are not a domain master browser.\n", local_master_name, inet_ntoa(p->ip)));
                goto done;
        }

        /* Add this host as a local master browser entry on the browse lists.
                This causes a sync request to be made to it at a later date.
        */

        if((browrec = find_browser_in_lmb_cache( local_master_name )) == NULL) {
                /* Add it. */
                create_browser_in_lmb_cache( work->work_group, local_master_name, p->ip);
        } else {
                update_browser_death_time(browrec);
        }

done:
        return;
}

/*******************************************************************
  Process an incoming LanMan host announcement packet.
*******************************************************************/

void process_lm_host_announce(struct subnet_record *subrec, struct packet_struct *p, const char *buf, int len)
{
        struct dgram_packet *dgram = &p->packet.dgram;
        uint32_t servertype = IVAL(buf,1);
        int osmajor=CVAL(buf,5);           /* major version of node software */
        int osminor=CVAL(buf,6);           /* minor version of node software */
        int ttl = SVAL(buf,7);
        unstring announce_name;
        struct work_record *work;
        struct server_record *servrec;
        unstring work_name;
        unstring source_name;
        fstring comment;
        char *s = get_safe_str_ptr(buf,len,discard_const_p(char, buf),9);

        if (!s) {
                goto done;
        }
        s = skip_string(buf,len,s);
        if (!s) {
                goto done;
        }
        pull_ascii(comment, s, sizeof(fstring), 43, STR_TERMINATE);

        pull_ascii_nstring(announce_name,sizeof(announce_name),buf+9);
        pull_ascii_nstring(source_name,sizeof(source_name),dgram->source_name.name);
        /* For a LanMan host announce the workgroup name is the destination name. */
        pull_ascii_nstring(work_name,sizeof(work_name),dgram->dest_name.name);

        DEBUG(3,("process_lm_host_announce: LM Announcement from %s IP %s to \
%s for server %s.\n", nmb_namestr(&dgram->source_name), inet_ntoa(p->ip),
                nmb_namestr(&dgram->dest_name),announce_name));

        DEBUG(5,("process_lm_host_announce: os=(%d,%d) ttl=%d server type=%08x comment=%s\n",
                osmajor, osminor, ttl, servertype,comment));

        if ((osmajor < 36) || (osmajor > 38) || (osminor !=0)) {
                DEBUG(5,("process_lm_host_announce: LM Announcement packet does not \
originate from OS/2 Warp client. Ignoring packet.\n"));
                /* Could have been from a Windows machine (with its LM Announce enabled),
                        or a Samba server. Then don't disrupt the current browse list. */
                goto done;
        }

        /* Filter servertype to remove impossible bits. */
        servertype &= ~(SV_TYPE_LOCAL_LIST_ONLY|SV_TYPE_DOMAIN_ENUM);

        /* A LanMan host announcement must be sent to the name WORKGROUP<00>. */
        if(dgram->dest_name.name_type != 0x00) {
                DEBUG(2,("process_lm_host_announce: incorrect name type for destination from IP %s \
(was %02x) should be 0x00. Allowing packet anyway.\n",
                        inet_ntoa(p->ip), dgram->dest_name.name_type));
                /* Change it so it was. */
                dgram->dest_name.name_type = 0x00;
        }

        /*
         * Syntax servers version 5.1 send HostAnnounce packets to
         * *THE WRONG NAME*. They send to LOCAL_MASTER_BROWSER_NAME<00>
         * instead of WORKGROUP<1d> name. So to fix this we check if
         * the workgroup name is our own name, and if so change it
         * to be our primary workgroup name. This code is probably
         * not needed in the LanMan announce code, but it won't hurt.
         */

        if(strequal(work_name, lp_netbios_name()))
                unstrcpy(work_name,lp_workgroup());

        /*
         * We are being very agressive here in adding a workgroup
         * name on the basis of a host announcing itself as being
         * in that workgroup. Maybe we should wait for the workgroup
         * announce instead ? JRA.
         */

        work = find_workgroup_on_subnet(subrec, work_name);

        if(servertype != 0) {
                if (work == NULL) {
                        /* We have no record of this workgroup. Add it. */
                        if((work = create_workgroup_on_subnet(subrec, work_name, ttl))==NULL)
                                goto done;
                }

                if((servrec = find_server_in_workgroup( work, announce_name))==NULL) {
                        /* If this server is not already in the workgroup, add it. */
                        create_server_on_workgroup(work, announce_name,
                                        servertype|SV_TYPE_LOCAL_LIST_ONLY,
                                        ttl, comment);
                } else {
                        /* Update the record. */
                        servrec->serv.type = servertype|SV_TYPE_LOCAL_LIST_ONLY;
                        update_server_ttl( servrec, ttl);
                        strlcpy(servrec->serv.comment,comment,sizeof(servrec->serv.comment));
                }
        } else {
                /*
                 * This server is announcing it is going down. Remove it from the
                 * workgroup.
                 */
                if(!is_myname(announce_name) && (work != NULL) &&
                                ((servrec = find_server_in_workgroup( work, announce_name))!=NULL)) {
                        remove_server_from_workgroup( work, servrec);
                }
        }

        subrec->work_changed = True;
        found_lm_clients = True;

done:
        return;
}

/****************************************************************************
  Send a backup list response.
*****************************************************************************/

static void send_backup_list_response(struct subnet_record *subrec,
                                      struct work_record *work,
                                      struct nmb_name *send_to_name,
                                      unsigned char max_number_requested,
                                      uint32_t token, struct in_addr sendto_ip,
                                      int port)
{
        char outbuf[1024];
        char *p, *countptr;
        unsigned int count = 0;
        unstring send_to_namestr;
#if 0
  struct server_record *servrec;
#endif
        unstring myname;

        memset(outbuf,'\0',sizeof(outbuf));

        DEBUG(3,("send_backup_list_response: sending backup list for workgroup %s to %s IP %s\n",
                work->work_group, nmb_namestr(send_to_name), inet_ntoa(sendto_ip)));

        p = outbuf;

        SCVAL(p,0,ANN_GetBackupListResp); /* Backup list response opcode. */
        p++;

        countptr = p;
        p++;

        SIVAL(p,0,token); /* The sender's unique info. */
        p += 4;

        /* We always return at least one name - our own. */
        count = 1;
        unstrcpy(myname, lp_netbios_name());
        if (!strupper_m(myname)) {
                DEBUG(4,("strupper_m %s failed\n", myname));
                return;
        }
        myname[15]='\0';
        push_ascii(p, myname, sizeof(outbuf)-PTR_DIFF(p,outbuf)-1, STR_TERMINATE);

        p = skip_string(outbuf,sizeof(outbuf),p);

        /* Look for backup browsers in this workgroup. */

#if 0
  /* we don't currently send become_backup requests so we should never
     send any other servers names out as backups for our
     workgroup. That's why this is commented out (tridge) */

  /*
   * NB. Note that the struct work_record here is not neccessarily
   * attached to the subnet *subrec.
   */

  for (servrec = work->serverlist; servrec; servrec = servrec->next)
  { 
    int len = PTR_DIFF(p, outbuf);
    if((sizeof(outbuf) - len) < 16)
      break;

    if(count >= (unsigned int)max_number_requested)
      break;

    if(strnequal(servrec->serv.name, lp_netbios_name(),15))
      continue;

    if(!(servrec->serv.type & SV_TYPE_BACKUP_BROWSER))
      continue;

    StrnCpy(p, servrec->serv.name, 15);
    strupper_m(p);
    count++;

    DEBUG(5,("send_backup_list_response: Adding server %s number %d\n",
              p, count));

    p = skip_string(outbuf,sizeof(outbuf),p);
  }
#endif

        SCVAL(countptr, 0, count);

        pull_ascii_nstring(send_to_namestr, sizeof(send_to_namestr), send_to_name->name);

        DEBUG(4,("send_backup_list_response: sending response to %s<00> IP %s with %d servers.\n",
                send_to_namestr, inet_ntoa(sendto_ip), count));

        send_mailslot(True, BROWSE_MAILSLOT,
                outbuf,PTR_DIFF(p,outbuf),
                lp_netbios_name(), 0,
                send_to_namestr,0,
                sendto_ip, subrec->myip, port);
}

/*******************************************************************
  Process a send backup list request packet.

  A client sends a backup list request to ask for a list of servers on
  the net that maintain server lists for a domain. A server is then
  chosen from this list to send NetServerEnum commands to to list
  available servers.

********************************************************************/

void process_get_backup_list_request(struct subnet_record *subrec,
                                     struct packet_struct *p,const char *buf)
{
        struct dgram_packet *dgram = &p->packet.dgram;
        struct work_record *work;
        unsigned char max_number_requested = CVAL(buf,0);
        uint32_t token = IVAL(buf,1); /* Sender's key index for the workgroup. */
        int name_type = dgram->dest_name.name_type;
        unstring workgroup_name;
        struct subnet_record *search_subrec = subrec;

        pull_ascii_nstring(workgroup_name, sizeof(workgroup_name), dgram->dest_name.name);

        DEBUG(3,("process_get_backup_list_request: request from %s IP %s to %s.\n",
                nmb_namestr(&dgram->source_name), inet_ntoa(p->ip),
                nmb_namestr(&dgram->dest_name)));
  
        /* We have to be a master browser, or a domain master browser
                for the requested workgroup. That means it must be our
                workgroup. */

        if(strequal(workgroup_name, lp_workgroup()) == False) {
                DEBUG(7,("process_get_backup_list_request: Ignoring announce request for workgroup %s.\n",
                        workgroup_name));
                goto done;
        }

        if((work = find_workgroup_on_subnet(search_subrec, workgroup_name)) == NULL) {
                DEBUG(0,("process_get_backup_list_request: Cannot find workgroup %s on \
subnet %s.\n", workgroup_name, search_subrec->subnet_name));
                goto done;
        }

        /* 
         * If the packet was sent to WORKGROUP<1b> instead
         * of WORKGROUP<1d> then it was unicast to us a domain master
         * browser. Change search subrec to unicast.
         */

        if(name_type == 0x1b) {
                /* We must be a domain master browser in order to
                        process this packet. */

                if(!AM_DOMAIN_MASTER_BROWSER(work)) {
                        DEBUG(0,("process_get_backup_list_request: domain list requested for workgroup %s \
and I am not a domain master browser.\n", workgroup_name));
                        goto done;
                }

                search_subrec = unicast_subnet;
        } else if (name_type == 0x1d) {
                /* We must be a local master browser in order to process this packet. */

                if(!AM_LOCAL_MASTER_BROWSER(work)) {
                        DEBUG(0,("process_get_backup_list_request: domain list requested for workgroup %s \
and I am not a local master browser.\n", workgroup_name));
                        goto done;
                }
        } else {
                DEBUG(0,("process_get_backup_list_request: Invalid name type %x - should be 0x1b or 0x1d.\n",
                        name_type));
                goto done;
        }

        send_backup_list_response(subrec, work, &dgram->source_name,
                        max_number_requested, token, p->ip, p->port);

done:
        return;
}

/*******************************************************************
  Process a reset browser state packet.

  Diagnostic packet:
  0x1 - Stop being a master browser and become a backup browser.
  0x2 - Discard browse lists, stop being a master browser, try again.
  0x4 - Stop being a master browser forever.
         
******************************************************************/

void process_reset_browser(struct subnet_record *subrec,
                                  struct packet_struct *p,const char *buf)
{
        struct dgram_packet *dgram = &p->packet.dgram;
        int state = CVAL(buf,0);
        struct subnet_record *sr;

        DEBUG(1,("process_reset_browser: received diagnostic browser reset \
request from %s IP %s state=0x%X\n",
                nmb_namestr(&dgram->source_name), inet_ntoa(p->ip), state));

        /* Stop being a local master browser on all our broadcast subnets. */
        if (state & 0x1) {
                for (sr = FIRST_SUBNET; sr; sr = NEXT_SUBNET_EXCLUDING_UNICAST(sr)) {
                        struct work_record *work;
                        for (work = sr->workgrouplist; work; work = work->next) {
                                if (AM_LOCAL_MASTER_BROWSER(work))
                                        unbecome_local_master_browser(sr, work, True);
                        }
                }
        }
  
        /* Discard our browse lists. */
        if (state & 0x2) {
                /*
                 * Calling expire_workgroups_and_servers with a -1
                 * time causes all servers not marked with a PERMANENT_TTL
                 * on the workgroup lists to be discarded, and all 
                 * workgroups with empty server lists to be discarded.
                 * This means we keep our own server names and workgroup
                 * as these have a PERMANENT_TTL.
                 */

                expire_workgroups_and_servers(-1);
        }
  
        /* Request to stop browsing altogether. */
        if (state & 0x4)
                DEBUG(1,("process_reset_browser: ignoring request to stop being a browser.\n"));
}

/*******************************************************************
  Process an announcement request packet.
  We don't respond immediately, we just check it's a request for
  our workgroup and then set the flag telling the announce code
  in nmbd_sendannounce.c:announce_my_server_names that an 
  announcement is needed soon.
******************************************************************/

void process_announce_request(struct subnet_record *subrec, struct packet_struct *p, const char *buf)
{
        struct dgram_packet *dgram = &p->packet.dgram;
        struct work_record *work;
        unstring workgroup_name;
 
        pull_ascii_nstring(workgroup_name, sizeof(workgroup_name), dgram->dest_name.name);
        DEBUG(3,("process_announce_request: Announce request from %s IP %s to %s.\n",
                nmb_namestr(&dgram->source_name), inet_ntoa(p->ip),
                nmb_namestr(&dgram->dest_name)));
  
        /* We only send announcement requests on our workgroup. */
        if(strequal(workgroup_name, lp_workgroup()) == False) {
                DEBUG(7,("process_announce_request: Ignoring announce request for workgroup %s.\n",
                        workgroup_name));
                goto done;
        }

        if((work = find_workgroup_on_subnet(subrec, workgroup_name)) == NULL) {
                DEBUG(0,("process_announce_request: Unable to find workgroup %s on subnet !\n",
                        workgroup_name));
                goto done;
        }

        work->needannounce = True;
done:
        return;
}

/*******************************************************************
  Process a LanMan announcement request packet.
  We don't respond immediately, we just check it's a request for
  our workgroup and then set the flag telling that we have found
  a LanMan client (DOS or OS/2) and that we will have to start
  sending LanMan announcements (unless specifically disabled
  through the "lm announce" parameter in smb.conf)
******************************************************************/

void process_lm_announce_request(struct subnet_record *subrec, struct packet_struct *p, const char *buf, int len)
{
        struct dgram_packet *dgram = &p->packet.dgram;
        unstring workgroup_name;

        pull_ascii_nstring(workgroup_name, sizeof(workgroup_name), dgram->dest_name.name);
        DEBUG(3,("process_lm_announce_request: Announce request from %s IP %s to %s.\n",
                nmb_namestr(&dgram->source_name), inet_ntoa(p->ip),
                nmb_namestr(&dgram->dest_name)));

        /* We only send announcement requests on our workgroup. */
        if(strequal(workgroup_name, lp_workgroup()) == False) {
                DEBUG(7,("process_lm_announce_request: Ignoring announce request for workgroup %s.\n",
                        workgroup_name));
                goto done;
        }

        if(find_workgroup_on_subnet(subrec, workgroup_name) == NULL) {
                DEBUG(0,("process_announce_request: Unable to find workgroup %s on subnet !\n",
                        workgroup_name));
                goto done;
        }

        found_lm_clients = True;

done:
        return;
}