source/nmbd/nmbd.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    NBT netbios routines and daemon - version 2
   4    Copyright (C) Andrew Tridgell 1994-1998
   5    Copyright (C) Jeremy Allison 1997-2002
   6    Copyright (C) Jelmer Vernooij 2002,2003 (Conversion to popt)
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 2 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program; if not, write to the Free Software
  20    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  21
  22 */
  23
  24 #include "includes.h"
  25
  26 int ClientNMB       = -1;
  27 int ClientDGRAM     = -1;
  28 int global_nmb_port = -1;
  29
  30 extern BOOL global_in_nmbd;
  31
  32 /* are we running as a daemon ? */
  33 static BOOL is_daemon;
  34
  35 /* fork or run in foreground ? */
  36 static BOOL Fork = True;
  37
  38 /* log to standard output ? */
  39 static BOOL log_stdout;
  40
  41 /* have we found LanMan clients yet? */
  42 BOOL found_lm_clients = False;
  43
  44 /* what server type are we currently */
  45
  46 time_t StartupTime = 0;
  47
  48 /**************************************************************************** **
  49  Handle a SIGTERM in band.
  50  **************************************************************************** */
  51
  52 static void terminate(void)
  53 {
  54         DEBUG(0,("Got SIGTERM: going down...\n"));
  55
  56         /* Write out wins.dat file if samba is a WINS server */
  57         wins_write_database(False);
  58
  59         /* Remove all SELF registered names from WINS */
  60         release_wins_names();
  61
  62         /* Announce all server entries as 0 time-to-live, 0 type. */
  63         announce_my_servers_removed();
  64
  65         /* If there was an async dns child - kill it. */
  66         kill_async_dns_child();
  67
  68         exit(0);
  69 }
  70
  71 /**************************************************************************** **
  72  Handle a SHUTDOWN message from smbcontrol.
  73  **************************************************************************** */
  74
  75 static void nmbd_terminate(int msg_type, pid_t src, void *buf, size_t len)
  76 {
  77         terminate();
  78 }
  79
  80 /**************************************************************************** **
  81  Catch a SIGTERM signal.
  82  **************************************************************************** */
  83
  84 static SIG_ATOMIC_T got_sig_term;
  85
  86 static void sig_term(int sig)
  87 {
  88         got_sig_term = 1;
  89         sys_select_signal();
  90 }
  91
  92 /**************************************************************************** **
  93  Catch a SIGHUP signal.
  94  **************************************************************************** */
  95
  96 static SIG_ATOMIC_T reload_after_sighup;
  97
  98 static void sig_hup(int sig)
  99 {
 100         reload_after_sighup = 1;
 101         sys_select_signal();
 102 }
 103
 104 #if DUMP_CORE
 105 /**************************************************************************** **
 106  Prepare to dump a core file - carefully!
 107  **************************************************************************** */
 108
 109 static BOOL dump_core(void)
 110 {
 111         char *p;
 112         pstring dname;
 113         pstrcpy( dname, lp_logfile() );
 114         if ((p=strrchr_m(dname,'/')))
 115                 *p=0;
 116         pstrcat( dname, "/corefiles" );
 117         mkdir( dname, 0700 );
 118         sys_chown( dname, getuid(), getgid() );
 119         chmod( dname, 0700 );
 120         if ( chdir(dname) )
 121                 return( False );
 122         umask( ~(0700) );
 123
 124 #ifdef HAVE_GETRLIMIT
 125 #ifdef RLIMIT_CORE
 126         {
 127                 struct rlimit rlp;
 128                 getrlimit( RLIMIT_CORE, &rlp );
 129                 rlp.rlim_cur = MAX( 4*1024*1024, rlp.rlim_cur );
 130                 setrlimit( RLIMIT_CORE, &rlp );
 131                 getrlimit( RLIMIT_CORE, &rlp );
 132                 DEBUG( 3, ( "Core limits now %d %d\n", (int)rlp.rlim_cur, (int)rlp.rlim_max ) );
 133         }
 134 #endif
 135 #endif
 136
 137
 138         DEBUG(0,("Dumping core in %s\n",dname));
 139         abort();
 140         return( True );
 141 }
 142 #endif
 143
 144 /**************************************************************************** **
 145  Possibly continue after a fault.
 146  **************************************************************************** */
 147
 148 static void fault_continue(void)
 149 {
 150 #if DUMP_CORE
 151         dump_core();
 152 #endif
 153 }
 154
 155 /**************************************************************************** **
 156  Expire old names from the namelist and server list.
 157  **************************************************************************** */
 158
 159 static void expire_names_and_servers(time_t t)
 160 {
 161         static time_t lastrun = 0;
 162
 163         if ( !lastrun )
 164                 lastrun = t;
 165         if ( t < (lastrun + 5) )
 166                 return;
 167         lastrun = t;
 168
 169         /*
 170          * Expire any timed out names on all the broadcast
 171          * subnets and those registered with the WINS server.
 172          * (nmbd_namelistdb.c)
 173          */
 174
 175         expire_names(t);
 176
 177         /*
 178          * Go through all the broadcast subnets and for each
 179          * workgroup known on that subnet remove any expired
 180          * server names. If a workgroup has an empty serverlist
 181          * and has itself timed out then remove the workgroup.
 182          * (nmbd_workgroupdb.c)
 183          */
 184
 185         expire_workgroups_and_servers(t);
 186 }
 187
 188 /************************************************************************** **
 189  Reload the list of network interfaces.
 190  ************************************************************************** */
 191
 192 static BOOL reload_interfaces(time_t t)
 193 {
 194         static time_t lastt;
 195         int n;
 196         struct subnet_record *subrec;
 197         extern BOOL rescan_listen_set;
 198         extern struct in_addr loopback_ip;
 199
 200         if (t && ((t - lastt) < NMBD_INTERFACES_RELOAD)) return False;
 201         lastt = t;
 202
 203         if (!interfaces_changed()) return False;
 204
 205         /* the list of probed interfaces has changed, we may need to add/remove
 206            some subnets */
 207         load_interfaces();
 208
 209         /* find any interfaces that need adding */
 210         for (n=iface_count() - 1; n >= 0; n--) {
 211                 struct interface *iface = get_interface(n);
 212
 213                 /*
 214                  * We don't want to add a loopback interface, in case
 215                  * someone has added 127.0.0.1 for smbd, nmbd needs to
 216                  * ignore it here. JRA.
 217                  */
 218
 219                 if (ip_equal(iface->ip, loopback_ip)) {
 220                         DEBUG(2,("reload_interfaces: Ignoring loopback interface %s\n", inet_ntoa(iface->ip)));
 221                         continue;
 222                 }
 223
 224                 for (subrec=subnetlist; subrec; subrec=subrec->next) {
 225                         if (ip_equal(iface->ip, subrec->myip) &&
 226                             ip_equal(iface->nmask, subrec->mask_ip)) break;
 227                 }
 228
 229                 if (!subrec) {
 230                         /* it wasn't found! add it */
 231                         DEBUG(2,("Found new interface %s\n",
 232                                  inet_ntoa(iface->ip)));
 233                         subrec = make_normal_subnet(iface);
 234                         if (subrec) register_my_workgroup_one_subnet(subrec);
 235                 }
 236         }
 237
 238         /* find any interfaces that need deleting */
 239         for (subrec=subnetlist; subrec; subrec=subrec->next) {
 240                 for (n=iface_count() - 1; n >= 0; n--) {
 241                         struct interface *iface = get_interface(n);
 242                         if (ip_equal(iface->ip, subrec->myip) &&
 243                             ip_equal(iface->nmask, subrec->mask_ip)) break;
 244                 }
 245                 if (n == -1) {
 246                         /* oops, an interface has disapeared. This is
 247                          tricky, we don't dare actually free the
 248                          interface as it could be being used, so
 249                          instead we just wear the memory leak and
 250                          remove it from the list of interfaces without
 251                          freeing it */
 252                         DEBUG(2,("Deleting dead interface %s\n",
 253                                  inet_ntoa(subrec->myip)));
 254                         close_subnet(subrec);
 255                 }
 256         }
 257
 258         rescan_listen_set = True;
 259
 260         /* We need to shutdown if there are no subnets... */
 261         if (FIRST_SUBNET == NULL) {
 262                 DEBUG(0,("reload_interfaces: No subnets to listen to. Shutting down...\n"));
 263                 return True;
 264         }
 265         return False;
 266 }
 267
 268 /**************************************************************************** **
 269  Reload the services file.
 270  **************************************************************************** */
 271
 272 static BOOL reload_nmbd_services(BOOL test)
 273 {
 274         BOOL ret;
 275
 276         set_remote_machine_name("nmbd", False);
 277
 278         if ( lp_loaded() ) {
 279                 pstring fname;
 280                 pstrcpy( fname,lp_configfile());
 281                 if (file_exist(fname,NULL) && !strcsequal(fname,dyn_CONFIGFILE)) {
 282                         pstrcpy(dyn_CONFIGFILE,fname);
 283                         test = False;
 284                 }
 285         }
 286
 287         if ( test && !lp_file_list_changed() )
 288                 return(True);
 289
 290         ret = lp_load( dyn_CONFIGFILE, True , False, False);
 291
 292         /* perhaps the config filename is now set */
 293         if ( !test ) {
 294                 DEBUG( 3, ( "services not loaded\n" ) );
 295                 reload_nmbd_services( True );
 296         }
 297
 298         return(ret);
 299 }
 300
 301 /**************************************************************************** **
 302  The main select loop.
 303  **************************************************************************** */
 304
 305 static void process(void)
 306 {
 307         BOOL run_election;
 308
 309         while( True ) {
 310                 time_t t = time(NULL);
 311
 312                 /* Check for internal messages */
 313
 314                 message_dispatch();
 315
 316                 /*
 317                  * Check all broadcast subnets to see if
 318                  * we need to run an election on any of them.
 319                  * (nmbd_elections.c)
 320                  */
 321
 322                 run_election = check_elections();
 323
 324                 /*
 325                  * Read incoming UDP packets.
 326                  * (nmbd_packets.c)
 327                  */
 328
 329                 if(listen_for_packets(run_election))
 330                         return;
 331
 332                 /*
 333                  * Handle termination inband.
 334                  */
 335
 336                 if (got_sig_term) {
 337                         got_sig_term = 0;
 338                         terminate();
 339                 }
 340
 341                 /*
 342                  * Process all incoming packets
 343                  * read above. This calls the success and
 344                  * failure functions registered when response
 345                  * packets arrrive, and also deals with request
 346                  * packets from other sources.
 347                  * (nmbd_packets.c)
 348                  */
 349
 350                 run_packet_queue();
 351
 352                 /*
 353                  * Run any elections - initiate becoming
 354                  * a local master browser if we have won.
 355                  * (nmbd_elections.c)
 356                  */
 357
 358                 run_elections(t);
 359
 360                 /*
 361                  * Send out any broadcast announcements
 362                  * of our server names. This also announces
 363                  * the workgroup name if we are a local
 364                  * master browser.
 365                  * (nmbd_sendannounce.c)
 366                  */
 367
 368                 announce_my_server_names(t);
 369
 370                 /*
 371                  * Send out any LanMan broadcast announcements
 372                  * of our server names.
 373                  * (nmbd_sendannounce.c)
 374                  */
 375
 376                 announce_my_lm_server_names(t);
 377
 378                 /*
 379                  * If we are a local master browser, periodically
 380                  * announce ourselves to the domain master browser.
 381                  * This also deals with syncronising the domain master
 382                  * browser server lists with ourselves as a local
 383                  * master browser.
 384                  * (nmbd_sendannounce.c)
 385                  */
 386
 387                 announce_myself_to_domain_master_browser(t);
 388
 389                 /*
 390                  * Fullfill any remote announce requests.
 391                  * (nmbd_sendannounce.c)
 392                  */
 393
 394                 announce_remote(t);
 395
 396                 /*
 397                  * Fullfill any remote browse sync announce requests.
 398                  * (nmbd_sendannounce.c)
 399                  */
 400
 401                 browse_sync_remote(t);
 402
 403                 /*
 404                  * Scan the broadcast subnets, and WINS client
 405                  * namelists and refresh any that need refreshing.
 406                  * (nmbd_mynames.c)
 407                  */
 408
 409                 refresh_my_names(t);
 410
 411                 /*
 412                  * Scan the subnet namelists and server lists and
 413                  * expire thos that have timed out.
 414                  * (nmbd.c)
 415                  */
 416
 417                 expire_names_and_servers(t);
 418
 419                 /*
 420                  * Write out a snapshot of our current browse list into
 421                  * the browse.dat file. This is used by smbd to service
 422                  * incoming NetServerEnum calls - used to synchronise
 423                  * browse lists over subnets.
 424                  * (nmbd_serverlistdb.c)
 425                  */
 426
 427                 write_browse_list(t, False);
 428
 429                 /*
 430                  * If we are a domain master browser, we have a list of
 431                  * local master browsers we should synchronise browse
 432                  * lists with (these are added by an incoming local
 433                  * master browser announcement packet). Expire any of
 434                  * these that are no longer current, and pull the server
 435                  * lists from each of these known local master browsers.
 436                  * (nmbd_browsesync.c)
 437                  */
 438
 439                 dmb_expire_and_sync_browser_lists(t);
 440
 441                 /*
 442                  * Check that there is a local master browser for our
 443                  * workgroup for all our broadcast subnets. If one
 444                  * is not found, start an election (which we ourselves
 445                  * may or may not participate in, depending on the
 446                  * setting of the 'local master' parameter.
 447                  * (nmbd_elections.c)
 448                  */
 449
 450                 check_master_browser_exists(t);
 451
 452                 /*
 453                  * If we are configured as a logon server, attempt to
 454                  * register the special NetBIOS names to become such
 455                  * (WORKGROUP<1c> name) on all broadcast subnets and
 456                  * with the WINS server (if used). If we are configured
 457                  * to become a domain master browser, attempt to register
 458                  * the special NetBIOS name (WORKGROUP<1b> name) to
 459                  * become such.
 460                  * (nmbd_become_dmb.c)
 461                  */
 462
 463                 add_domain_names(t);
 464
 465                 /*
 466                  * If we are a WINS server, do any timer dependent
 467                  * processing required.
 468                  * (nmbd_winsserver.c)
 469                  */
 470
 471                 initiate_wins_processing(t);
 472
 473                 /*
 474                  * If we are a domain master browser, attempt to contact the
 475                  * WINS server to get a list of all known WORKGROUPS/DOMAINS.
 476                  * This will only work to a Samba WINS server.
 477                  * (nmbd_browsesync.c)
 478                  */
 479
 480                 if (lp_enhanced_browsing())
 481                         collect_all_workgroup_names_from_wins_server(t);
 482
 483                 /*
 484                  * Go through the response record queue and time out or re-transmit
 485                  * and expired entries.
 486                  * (nmbd_packets.c)
 487                  */
 488
 489                 retransmit_or_expire_response_records(t);
 490
 491                 /*
 492                  * check to see if any remote browse sync child processes have completed
 493                  */
 494
 495                 sync_check_completion();
 496
 497                 /*
 498                  * regularly sync with any other DMBs we know about
 499                  */
 500
 501                 if (lp_enhanced_browsing())
 502                         sync_all_dmbs(t);
 503
 504                 /*
 505                  * clear the unexpected packet queue
 506                  */
 507
 508                 clear_unexpected(t);
 509
 510                 /*
 511                  * Reload the services file if we got a sighup.
 512                  */
 513
 514                 if(reload_after_sighup) {
 515                         DEBUG( 0, ( "Got SIGHUP dumping debug info.\n" ) );
 516                         write_browse_list( 0, True );
 517                         dump_all_namelists();
 518                         reload_nmbd_services( True );
 519                         reopen_logs();
 520                         if(reload_interfaces(0))
 521                                 return;
 522                         reload_after_sighup = 0;
 523                 }
 524
 525                 /* check for new network interfaces */
 526
 527                 if(reload_interfaces(t))
 528                         return;
 529
 530                 /* free up temp memory */
 531                         lp_talloc_free();
 532         }
 533 }
 534
 535 /**************************************************************************** **
 536  Open the socket communication.
 537  **************************************************************************** */
 538
 539 static BOOL open_sockets(BOOL isdaemon, int port)
 540 {
 541         /*
 542          * The sockets opened here will be used to receive broadcast
 543          * packets *only*. Interface specific sockets are opened in
 544          * make_subnet() in namedbsubnet.c. Thus we bind to the
 545          * address "0.0.0.0". The parameter 'socket address' is
 546          * now deprecated.
 547          */
 548
 549         if ( isdaemon )
 550                 ClientNMB = open_socket_in(SOCK_DGRAM, port,
 551                                            interpret_addr(lp_socket_address()),
 552                                            0,True);
 553         else
 554                 ClientNMB = 0;
 555
 556         ClientDGRAM = open_socket_in(SOCK_DGRAM,DGRAM_PORT,3,0,True);
 557
 558         if ( ClientNMB == -1 )
 559                 return( False );
 560
 561         /* we are never interested in SIGPIPE */
 562         BlockSignals(True,SIGPIPE);
 563
 564         set_socket_options( ClientNMB,   "SO_BROADCAST" );
 565         set_socket_options( ClientDGRAM, "SO_BROADCAST" );
 566
 567         DEBUG( 3, ( "open_sockets: Broadcast sockets opened.\n" ) );
 568         return( True );
 569 }
 570
 571 /**************************************************************************** **
 572  main program
 573  **************************************************************************** */
 574  int main(int argc, const char *argv[])
 575 {
 576         pstring logfile;
 577         static BOOL opt_interactive;
 578         poptContext pc;
 579         int opt;
 580         struct poptOption long_options[] = {
 581         POPT_AUTOHELP
 582         {"daemon", 'D', POPT_ARG_VAL, &is_daemon, True, "Become a daemon(default)" },
 583         {"interactive", 'i', POPT_ARG_VAL, &opt_interactive, True, "Run interactive (not a daemon)" },
 584         {"foreground", 'F', POPT_ARG_VAL, &Fork, False, "Run daemon in foreground (for daemontools & etc)" },
 585         {"log-stdout", 'S', POPT_ARG_VAL, &log_stdout, True, "Log to stdout" },
 586         {"hosts", 'H', POPT_ARG_STRING, dyn_LMHOSTSFILE, 'H', "Load a netbios hosts file"},
 587         {"port", 'p', POPT_ARG_INT, &global_nmb_port, NMB_PORT, "Listen on the specified port" },
 588         POPT_COMMON_SAMBA
 589         { NULL }
 590         };
 591
 592         global_nmb_port = NMB_PORT;
 593
 594         pc = poptGetContext("nmbd", argc, argv, long_options, 0);
 595         while ((opt = poptGetNextOpt(pc)) != -1) ;
 596         poptFreeContext(pc);
 597
 598         global_in_nmbd = True;
 599
 600         StartupTime = time(NULL);
 601
 602         sys_srandom(time(NULL) ^ sys_getpid());
 603
 604         slprintf(logfile, sizeof(logfile)-1, "%s/log.nmbd", dyn_LOGFILEBASE);
 605         lp_set_logfile(logfile);
 606
 607         fault_setup((void (*)(void *))fault_continue );
 608
 609         /* POSIX demands that signals are inherited. If the invoking process has
 610          * these signals masked, we will have problems, as we won't receive them. */
 611         BlockSignals(False, SIGHUP);
 612         BlockSignals(False, SIGUSR1);
 613         BlockSignals(False, SIGTERM);
 614
 615         CatchSignal( SIGHUP,  SIGNAL_CAST sig_hup );
 616         CatchSignal( SIGTERM, SIGNAL_CAST sig_term );
 617
 618 #if defined(SIGFPE)
 619         /* we are never interested in SIGFPE */
 620         BlockSignals(True,SIGFPE);
 621 #endif
 622
 623         /* We no longer use USR2... */
 624 #if defined(SIGUSR2)
 625         BlockSignals(True, SIGUSR2);
 626 #endif
 627
 628         if ( opt_interactive ) {
 629                 Fork = False;
 630                 log_stdout = True;
 631         }
 632
 633   if ( log_stdout && Fork ) {
 634     DEBUG(0,("ERROR: Can't log to stdout (-S) unless daemon is in foreground (-F) or interactive (-i)\n"));
 635     exit(1);
 636   }
 637
 638   setup_logging( argv[0], log_stdout );
 639
 640   reopen_logs();
 641
 642   DEBUG( 0, ( "Netbios nameserver version %s started.\n", VERSION ) );
 643   DEBUGADD( 0, ( "Copyright Andrew Tridgell and the Samba Team 1994-2003\n" ) );
 644
 645   if ( !reload_nmbd_services(False) )
 646     return(-1);
 647
 648   if(!init_names())
 649     return -1;
 650
 651   reload_nmbd_services( True );
 652
 653   if (strequal(lp_workgroup(),"*"))
 654   {
 655     DEBUG(0,("ERROR: a workgroup name of * is no longer supported\n"));
 656     exit(1);
 657   }
 658
 659   set_samba_nb_type();
 660
 661   if (!is_daemon && !is_a_socket(0))
 662   {
 663     DEBUG(0,("standard input is not a socket, assuming -D option\n"));
 664     is_daemon = True;
 665   }
 666
 667   if (is_daemon && !opt_interactive)
 668   {
 669     DEBUG( 2, ( "Becoming a daemon.\n" ) );
 670     become_daemon(Fork);
 671   }
 672
 673 #if HAVE_SETPGID
 674   /*
 675    * If we're interactive we want to set our own process group for
 676    * signal management.
 677    */
 678   if (opt_interactive)
 679     setpgid( (pid_t)0, (pid_t)0 );
 680 #endif
 681
 682 #ifndef SYNC_DNS
 683   /* Setup the async dns. We do it here so it doesn't have all the other
 684      stuff initialised and thus chewing memory and sockets */
 685   if(lp_we_are_a_wins_server() && lp_dns_proxy()) {
 686           start_async_dns();
 687   }
 688 #endif
 689
 690   if (!directory_exist(lp_lockdir(), NULL)) {
 691           mkdir(lp_lockdir(), 0755);
 692   }
 693
 694   pidfile_create("nmbd");
 695   message_init();
 696   message_register(MSG_FORCE_ELECTION, nmbd_message_election);
 697   message_register(MSG_WINS_NEW_ENTRY, nmbd_wins_new_entry);
 698   message_register(MSG_SHUTDOWN, nmbd_terminate);
 699
 700   DEBUG( 3, ( "Opening sockets %d\n", global_nmb_port ) );
 701
 702   if ( !open_sockets( is_daemon, global_nmb_port ) ) {
 703     kill_async_dns_child();
 704     return 1;
 705   }
 706
 707   /* Determine all the IP addresses we have. */
 708   load_interfaces();
 709
 710   /* Create an nmbd subnet record for each of the above. */
 711   if( False == create_subnets() )
 712   {
 713     DEBUG(0,("ERROR: Failed when creating subnet lists. Exiting.\n"));
 714     kill_async_dns_child();
 715     exit(1);
 716   }
 717
 718   /* Load in any static local names. */
 719   load_lmhosts_file(dyn_LMHOSTSFILE);
 720   DEBUG(3,("Loaded hosts file %s\n", dyn_LMHOSTSFILE));
 721
 722   /* If we are acting as a WINS server, initialise data structures. */
 723   if( !initialise_wins() )
 724   {
 725     DEBUG( 0, ( "nmbd: Failed when initialising WINS server.\n" ) );
 726     kill_async_dns_child();
 727     exit(1);
 728   }
 729
 730   /*
 731    * Register nmbd primary workgroup and nmbd names on all
 732    * the broadcast subnets, and on the WINS server (if specified).
 733    * Also initiate the startup of our primary workgroup (start
 734    * elections if we are setup as being able to be a local
 735    * master browser.
 736    */
 737
 738   if( False == register_my_workgroup_and_names() )
 739   {
 740     DEBUG(0,("ERROR: Failed when creating my my workgroup. Exiting.\n"));
 741     kill_async_dns_child();
 742     exit(1);
 743   }
 744
 745   /* We can only take signals in the select. */
 746   BlockSignals( True, SIGTERM );
 747
 748   process();
 749
 750   if (dbf)
 751     x_fclose(dbf);
 752   kill_async_dns_child();
 753   return(0);
 754 }