/*
   Unix SMB/Netbios implementation.
   Version 1.9.
   NBT netbios routines and daemon - version 2
   Copyright (C) Andrew Tridgell 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 2 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, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
   
   Revision History:

   14 jan 96: lkcl@pires.co.uk
   added multiple workgroup domain master support

*/

#include "includes.h"

extern int DEBUGLEVEL;

extern pstring debugf;
pstring servicesf = CONFIGFILE;

extern pstring scope;

int ClientNMB       = -1;
int ClientDGRAM     = -1;
int global_nmb_port = -1;

extern pstring myhostname;
static pstring host_file;
extern pstring myname;
extern fstring myworkgroup;
extern char **my_netbios_names;

/* are we running as a daemon ? */
static BOOL is_daemon = False;

/* have we found LanMan clients yet? */
BOOL found_lm_clients = False;

/* what server type are we currently */

time_t StartupTime = 0;

extern struct in_addr ipzero;

/**************************************************************************** **
  catch a sigterm
 **************************************************************************** */
static int sig_term()
{
  BlockSignals(True,SIGTERM);
  
  DEBUG(0,("Got SIGTERM: going down...\n"));
  
  /* Write out wins.dat file if samba is a WINS server */
  wins_write_database();
  
  /* Remove all SELF registered names. */
  release_my_names();
  
  /* Announce all server entries as 0 time-to-live, 0 type. */
  announce_my_servers_removed();

  exit(0);

  /* Keep compiler happy.. */
  return 0;
} /* sig_term */

/**************************************************************************** **
 catch a sighup
 **************************************************************************** */
static int sig_hup(void)
{
  BlockSignals( True, SIGHUP );

  DEBUG( 0, ( "Got SIGHUP dumping debug info.\n" ) );

  write_browse_list( 0, True );

  dump_all_namelists();
  reload_services( True );

  set_samba_nb_type();

  BlockSignals(False,SIGHUP);
#ifndef DONT_REINSTALL_SIG
  signal(SIGHUP,SIGNAL_CAST sig_hup);
#endif
  return(0);
} /* sig_hup */

/**************************************************************************** **
 catch a sigpipe
 **************************************************************************** */
static int sig_pipe(void)
{
  BlockSignals( True, SIGPIPE );

  DEBUG( 0, ("Got SIGPIPE\n") );
  if ( !is_daemon )
    exit(1);
  BlockSignals( False, SIGPIPE );
  return(0);
} /* sig_pipe */

#if DUMP_CORE
/**************************************************************************** **
 prepare to dump a core file - carefully!
 **************************************************************************** */
static BOOL dump_core(void)
{
  char *p;
  pstring dname;
  pstrcpy( dname, debugf );
  if ((p=strrchr(dname,'/')))
    *p=0;
  strcat( dname, "/corefiles" );
  mkdir( dname, 0700 );
  sys_chown( dname, getuid(), getgid() );
  chmod( dname, 0700 );
  if ( chdir(dname) )
    return( False );
  umask( ~(0700) );

#ifndef NO_GETRLIMIT
#ifdef RLIMIT_CORE
  {
    struct rlimit rlp;
    getrlimit( RLIMIT_CORE, &rlp );
    rlp.rlim_cur = MAX( 4*1024*1024, rlp.rlim_cur );
    setrlimit( RLIMIT_CORE, &rlp );
    getrlimit( RLIMIT_CORE, &rlp );
    DEBUG( 3, ( "Core limits now %d %d\n", rlp.rlim_cur, rlp.rlim_max ) );
  }
#endif
#endif


  DEBUG( 0, ( "Dumping core in %s\n",dname ) );
  return( True );
} /* dump_core */
#endif


/**************************************************************************** **
 possibly continue after a fault
 **************************************************************************** */
static void fault_continue(void)
{
#if DUMP_CORE
  dump_core();
#endif
} /* fault_continue */

/**************************************************************************** **
 expire old names from the namelist and server list
 **************************************************************************** */
static void expire_names_and_servers(time_t t)
{
  static time_t lastrun = 0;
  
  if ( !lastrun )
    lastrun = t;
  if ( t < (lastrun + 5) )
    return;
  lastrun = t;

  /*
   * Expire any timed out names on all the broadcast
   * subnets and those registered with the WINS server.
   * (nmbd_namelistdb.c)
   */
  expire_names(t);

  /*
   * Go through all the broadcast subnets and for each
   * workgroup known on that subnet remove any expired
   * server names. If a workgroup has an empty serverlist
   * and has itself timed out then remove the workgroup.
   * (nmbd_workgroupdb.c)
   */
  expire_workgroups_and_servers(t);
} /* expire_names_and_servers */

/**************************************************************************** **
  reload the services file
 **************************************************************************** */
BOOL reload_services(BOOL test)
{
  BOOL ret;
  extern fstring remote_machine;

  strcpy( remote_machine, "nmbd" );

  if ( lp_loaded() )
  {
    pstring fname;
    pstrcpy( fname,lp_configfile());
    if (file_exist(fname,NULL) && !strcsequal(fname,servicesf))
    {
      pstrcpy(servicesf,fname);
      test = False;
    }
  }

  if ( test && !lp_file_list_changed() )
    return(True);

  ret = lp_load( servicesf, True );

  /* perhaps the config filename is now set */
  if ( !test )
  {
    DEBUG( 3, ( "services not loaded\n" ) );
    reload_services( True );
  }

  /* Do a sanity check for a misconfigured nmbd */
  if( lp_wins_support() && *lp_wins_server() )
  {
    DEBUG(0,("ERROR: both 'wins support = true' and 'wins server = <server>' \
cannot be set in the smb.conf file. nmbd aborting.\n"));
    exit(10);
  }

  return(ret);
} /* reload_services */

/**************************************************************************** **
 The main select loop.
 **************************************************************************** */
static void process(void)
{
  BOOL run_election;

  while( True )
  {
    time_t t = time(NULL);

    /*
     * Check all broadcast subnets to see if
     * we need to run an election on any of them.
     * (nmbd_elections.c)
     */
    run_election = check_elections();

    /*
     * Read incoming UDP packets.
     * (nmbd_packets.c)
     */
    if(listen_for_packets(run_election))
      return;

    /*
     * Process all incoming packets
     * read above. This calls the success and
     * failure functions registered when response
     * packets arrrive, and also deals with request
     * packets from other sources.
     * (nmbd_packets.c)
     */
    run_packet_queue();

    /*
     * Run any elections - initiate becoming
     * a local master browser if we have won.
     * (nmbd_elections.c)
     */
    run_elections(t);

    /*
     * Send out any broadcast announcements
     * of our server names. This also announces
     * the workgroup name if we are a local
     * master browser.
     * (nmbd_sendannounce.c)
     */
    announce_my_server_names(t);

    /*
     * Send out any LanMan broadcast announcements
     * of our server names.
     * (nmbd_sendannounce.c)
     */
    announce_my_lm_server_names(t);

    /*
     * If we are a local master browser, periodically
     * announce ourselves to the domain master browser.
     * This also deals with syncronising the domain master
     * browser server lists with ourselves as a local
     * master browser.
     * (nmbd_sendannounce.c)
     */
    announce_myself_to_domain_master_browser(t);

    /*
     * Fullfill any remote announce requests.
     * (nmbd_sendannounce.c)
     */
    announce_remote(t);

    /*
     * Fullfill any remote browse sync announce requests.
     * (nmbd_sendannounce.c)
     */
    browse_sync_remote(t);

    /*
     * Scan the broadcast subnets, and WINS client
     * namelists and refresh any that need refreshing.
     * (nmbd_mynames.c)
     */
    refresh_my_names(t);

    /*
     * Scan the subnet namelists and server lists and
     * expire thos that have timed out.
     * (nmbd.c)
     */
    expire_names_and_servers(t);

    /*
     * Write out a snapshot of our current browse list into
     * the browse.dat file. This is used by smbd to service
     * incoming NetServerEnum calls - used to synchronise
     * browse lists over subnets.
     * (nmbd_serverlistdb.c)
     */
    write_browse_list(t, False);

    /*
     * If we are a domain master browser, we have a list of
     * local master browsers we should synchronise browse
     * lists with (these are added by an incoming local
     * master browser announcement packet). Expire any of
     * these that are no longer current, and pull the server
     * lists from each of these known local master browsers.
     * (nmbd_browsesync.c)
     */
    dmb_expire_and_sync_browser_lists(t);

    /*
     * Check that there is a local master browser for our
     * workgroup for all our broadcast subnets. If one
     * is not found, start an election (which we ourselves
     * may or may not participate in, depending on the
     * setting of the 'local master' parameter.
     * (nmbd_elections.c)
     */
    check_master_browser_exists(t);

    /*
     * If we are configured as a logon server, attempt to
     * register the special NetBIOS names to become such
     * (WORKGROUP<1c> name) on all broadcast subnets and
     * with the WINS server (if used). If we are configured
     * to become a domain master browser, attempt to register
     * the special NetBIOS name (WORKGROUP<1b> name) to
     * become such.
     * (nmbd_become_dmb.c)
     */
    add_domain_names(t);

    /*
     * If we are a WINS server, do any timer dependent
     * processing required.
     * (nmbd_winsserver.c)
     */
    initiate_wins_processing(t);

    /*
     * If we are a domain master browser, attempt to contact the
     * WINS server to get a list of all known WORKGROUPS/DOMAINS.
     * This will only work to a Samba WINS server.
     * (nmbd_browsesync.c)
     */
    collect_all_workgroup_names_from_wins_server(t);

    /*
     * Go through the response record queue and time out or re-transmit
     * and expired entries.
     * (nmbd_packets.c)
     */
    retransmit_or_expire_response_records(t);
  }
} /* process */


/**************************************************************************** **
 open the socket communication
 **************************************************************************** */
static BOOL open_sockets(BOOL isdaemon, int port)
{
  /* The sockets opened here will be used to receive broadcast
     packets *only*. Interface specific sockets are opened in
     make_subnet() in namedbsubnet.c. Thus we bind to the
     address "0.0.0.0". The parameter 'socket address' is
     now deprecated.
   */

  if ( isdaemon )
    ClientNMB = open_socket_in(SOCK_DGRAM, port,0,0);
  else
    ClientNMB = 0;
  
  ClientDGRAM = open_socket_in(SOCK_DGRAM,DGRAM_PORT,3,0);

  if ( ClientNMB == -1 )
    return( False );

  signal( SIGPIPE, SIGNAL_CAST sig_pipe );

  set_socket_options( ClientNMB,   "SO_BROADCAST" );
  set_socket_options( ClientDGRAM, "SO_BROADCAST" );

  DEBUG( 3, ( "open_sockets: Broadcast sockets opened.\n" ) );
  return( True );
} /* open_sockets */


/**************************************************************************** **
 initialise connect, service and file structs
 **************************************************************************** */
static BOOL init_structs()
{
  extern fstring local_machine;
  char *p, *ptr;
  int namecount;
  int n;
  int nodup;
  pstring nbname;

  if (! *myname)
  {
    fstrcpy( myname, myhostname );
    p = strchr( myname, '.' );
    if (p)
      *p = 0;
  }
  strupper( myname );

  /* Add any NETBIOS name aliases. Ensure that the first entry
     is equal to myname.
   */
  /* Work out the max number of netbios aliases that we have */
  ptr = lp_netbios_aliases();
  for( namecount=0; next_token(&ptr,nbname,NULL); namecount++ )
    ;
  if ( *myname )
    namecount++;

  /* Allocate space for the netbios aliases */
  my_netbios_names = (char **)malloc( sizeof(char *) * (namecount+1) );
  if( NULL == my_netbios_names )
  {
     DEBUG( 0, ( "init_structs: malloc fail.\n" ) );
     return( False );
  }
 
  /* Use the myname string first */
  namecount=0;
  if ( *myname )
    my_netbios_names[namecount++] = myname;
  
  ptr = lp_netbios_aliases();
  while ( next_token( &ptr, nbname, NULL ) )
  {
    strupper( nbname );
    /* Look for duplicates */
    nodup=1;
    for( n=0; n<namecount; n++ )
    {
      if( 0 == strcmp( nbname, my_netbios_names[n] ) )
        nodup=0;
    }
    if (nodup)
      my_netbios_names[namecount++] = strdup( nbname );
  }
  
  /* Check the strdups succeeded. */
  for( n = 0; n < namecount; n++ )
    if( NULL == my_netbios_names[n] )
    {
      DEBUG(0,("init_structs: malloc fail when allocating names.\n"));
      return False;
    }
  
  /* Terminate name list */
  my_netbios_names[namecount++] = NULL;
  
  fstrcpy( local_machine, myname );
  trim_string( local_machine, " ", " " );
  p = strchr( local_machine, ' ' );
  if (p)
    *p = 0;
  strlower( local_machine );

  DEBUG( 5, ("Netbios name list:-\n") );
  for( n=0; my_netbios_names[n]; n++ )
    DEBUG( 5, ( "my_netbios_names[%d]=\"%s\"\n", n, my_netbios_names[n] ) );

  return( True );
} /* init_structs */

/**************************************************************************** **
 usage on the program
 **************************************************************************** */
static void usage(char *pname)
{
  DEBUG(0,("Incorrect program usage - is the command line correct?\n"));

  printf( "Usage: %s [-n name] [-D] [-p port] [-d debuglevel] ", pname );
  printf( "[-l log basename]\n" );
  printf( "Version %s\n", VERSION );
  printf( "\t-D                    become a daemon\n" );
  printf( "\t-p port               listen on the specified port\n" );
  printf( "\t-d debuglevel         set the debuglevel\n" );
  printf( "\t-l log basename.      Basename for log/debug files\n" );
  printf( "\t-n netbiosname.       " );
  printf( "the netbios name to advertise for this host\n");
  printf( "\t-H hosts file         load a netbios hosts file\n" );
  printf( "\n");
} /* usage */


/**************************************************************************** **
 main program
 **************************************************************************** */
int main(int argc,char *argv[])
{
  int opt;
  extern FILE *dbf;
  extern char *optarg;
  char pidFile[100] = { 0 };

  global_nmb_port = NMB_PORT;
  *host_file = 0;

  StartupTime = time(NULL);

  TimeInit();

  strcpy( debugf, NMBLOGFILE );

  setup_logging( argv[0], False );

  charset_initialise();

#ifdef LMHOSTSFILE
  strcpy( host_file, LMHOSTSFILE );
#endif

  /* this is for people who can't start the program correctly */
  while (argc > 1 && (*argv[1] != '-'))
  {
    argv++;
    argc--;
  }

  fault_setup( fault_continue );

  signal( SIGHUP,  SIGNAL_CAST sig_hup );
  signal( SIGTERM, SIGNAL_CAST sig_term );

  /* Setup the signals that allow the debug log level
     to by dynamically changed. */

#if defined(SIGUSR1)
  signal( SIGUSR1, SIGNAL_CAST sig_usr1 );
#endif /* SIGUSR1 */

#if defined(SIGUSR2)
  signal( SIGUSR2, SIGNAL_CAST sig_usr2 );
#endif /* SIGUSR2 */

  while((opt = getopt(argc, argv, "as:T:I:C:bAi:B:N:Rn:l:d:Dp:hSH:G:f:")) != EOF)
    {
      switch (opt)
        {
        case 'f':
          strncpy(pidFile, optarg, sizeof(pidFile));
          break;
        case 's':
          pstrcpy(servicesf,optarg);
          break;          
        case 'N':
        case 'B':
        case 'I':
        case 'C':
        case 'G':
          DEBUG(0,("Obsolete option '%c' used\n",opt));
          break;
        case 'H':
          pstrcpy(host_file,optarg);
          break;
        case 'n':
          pstrcpy(myname,optarg);
          strupper(myname);
          break;
        case 'l':
          sprintf(debugf,"%s.nmb",optarg);
          break;
        case 'i':
          pstrcpy(scope,optarg);
          strupper(scope);
          break;
        case 'a':
          {
          extern BOOL append_log;
          append_log = !append_log;
          }
          break;
        case 'D':
          is_daemon = True;
          break;
        case 'd':
          DEBUGLEVEL = atoi(optarg);
          break;
        case 'p':
          global_nmb_port = atoi(optarg);
          break;
        case 'h':
          usage(argv[0]);
          exit(0);
          break;
        default:
          if (!is_a_socket(0))
          {
            usage(argv[0]);
          }
          break;
        }
    }

  DEBUG(1,("%s netbios nameserver version %s started\n",timestring(),VERSION));
  DEBUG(1,("Copyright Andrew Tridgell 1994-1997\n"));

  if( !get_myname( myhostname, NULL) )
  {
    DEBUG(0,("Unable to get my hostname - exiting.\n"));
    return -1;
  }

  if ( !reload_services(False) )
    return(-1);

  codepage_initialise(lp_client_code_page());

  if(!init_structs())
    return -1;

  reload_services( True );

  fstrcpy( myworkgroup, lp_workgroup() );

  if (strequal(myworkgroup,"*"))
  {
    DEBUG(0,("ERROR: a workgroup name of * is no longer supported\n"));
    exit(1);
  }

  set_samba_nb_type();

  if (!is_daemon && !is_a_socket(0))
  {
    DEBUG(0,("standard input is not a socket, assuming -D option\n"));
    is_daemon = True;
  }
  
  if (is_daemon)
  {
    DEBUG(2,("%s becoming a daemon\n",timestring()));
    become_daemon();
  }

  if (!directory_exist(lp_lockdir(), NULL))
  {
    mkdir(lp_lockdir(), 0755);
  }

  if (*pidFile)
  {
    int     fd;
    char    buf[20];

#ifdef O_NONBLOCK
    fd = open( pidFile, O_NONBLOCK | O_CREAT | O_WRONLY | O_TRUNC, 0644 );
#else
    fd = open( pidFile, O_CREAT | O_WRONLY | O_TRUNC, 0644 );
#endif
    if ( fd < 0 )
    {
      DEBUG(0,("ERROR: can't open %s: %s\n", pidFile, strerror(errno)));
      exit(1);
    }
    if (fcntl_lock(fd,F_SETLK,0,1,F_WRLCK)==False)
    {
      DEBUG(0,("ERROR: nmbd is already running\n"));
      exit(1);
    }
    sprintf(buf, "%u\n", (unsigned int) getpid());
    if (write(fd, buf, strlen(buf)) < 0)
    {
      DEBUG(0,("ERROR: can't write to %s: %s\n", pidFile, strerror(errno)));
      exit(1);
    }
      /* Leave pid file open & locked for the duration... */
  }


  DEBUG( 3, ( "Opening sockets %d\n", global_nmb_port ) );

  if ( !open_sockets( is_daemon, global_nmb_port ) )
    return 1;

  /* Determine all the IP addresses we have. */
  load_interfaces();

  /* Create an nmbd subnet record for each of the above. */
  if( False == create_subnets() )
  {
    DEBUG(0,("ERROR: Failed when creating subnet lists. Exiting.\n"));
    exit(1);
  }

  /* Load in any static local names. */ 
  if ( *host_file )
  {
    load_lmhosts_file(host_file);
    DEBUG(3,("Loaded hosts file\n"));
  }

  /* If we are acting as a WINS server, initialise data structures. */
  if( !initialise_wins() )
  {
    DEBUG( 0, ( "nmbd: Failed when initialising WINS server.\n" ) );
    exit(1);
  }

  /* 
   * Register nmbd primary workgroup and nmbd names on all
   * the broadcast subnets, and on the WINS server (if specified).
   * Also initiate the startup of our primary workgroup (start
   * elections if we are setup as being able to be a local
   * master browser.
   */

  if( False == register_my_workgroup_and_names() )
  {
    DEBUG(0,("ERROR: Failed when creating my my workgroup. Exiting.\n"));
    exit(1);
  }

  /* We can only take signals in the select. */
  BlockSignals( True, SIGTERM );
#if defined(SIGUSR1)
  BlockSignals( True, SIGUSR1);
#endif /* SIGUSR1 */
#if defined(SIGUSR2)
  BlockSignals( True, SIGUSR2);
#endif /* SIGUSR2 */

  process();
  close_sockets();

  if (dbf)
    fclose(dbf);
  return(0);
} /* main */

/* ========================================================================== */