summaryrefslogtreecommitdiff
path: root/source3/nameelect.c
blob: 4aacee55d419a5bdd1a6d0a4e19e216e8454d260 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
/* 
   Unix SMB/Netbios implementation.
   Version 1.9.
   NBT netbios routines and daemon - version 2
   Copyright (C) Andrew Tridgell 1994-1996
   
   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.
   
   Module name: nameelect.c

   Revision History:

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

   04 jul 96: lkcl@pires.co.uk
   added system to become a master browser by stages.


*/

#include "includes.h"

extern int ClientNMB;
extern int ClientDGRAM;

extern int DEBUGLEVEL;
extern pstring scope;

extern pstring myname;
extern struct in_addr ipzero;
extern struct in_addr wins_ip;

/* here are my election parameters */

extern time_t StartupTime;

extern struct subnet_record *subnetlist;

extern uint16 nb_type; /* samba's NetBIOS name type */


/*******************************************************************
  occasionally check to see if the master browser is around
  ******************************************************************/
void check_master_browser(time_t t)
{
	static time_t lastrun=0;
	struct subnet_record *d;

	if (!lastrun) lastrun = t;
	if (t < lastrun + CHECK_TIME_MST_BROWSE * 60) return;

	lastrun = t;

	dump_workgroups();

	for (d = subnetlist; d; d = d->next)
	{
		struct work_record *work;

                /* don't do election stuff on the WINS subnet */
               if (ip_equal(d->bcast_ip,wins_ip)) 
                  continue;

		for (work = d->workgrouplist; work; work = work->next)
		{
			if (strequal(work->work_group, lp_workgroup()) && !AM_MASTER(work))
			{
				if (lp_preferred_master())
				{
					/* preferred master - not a master browser.  force
					   becoming a master browser, hence the log message.
					 */

					DEBUG(0,("%s preferred master for %s %s - force election\n",
					          timestring(), work->work_group,
					          inet_ntoa(d->bcast_ip)));

					browser_gone(work->work_group, d->bcast_ip);
				}
				else
				{
					/* if we are not the browse master of a workgroup,
					   and we can't find a browser on the subnet, do
					   something about it.
					 */

					queue_netbios_packet(d,ClientNMB,NMB_QUERY,NAME_QUERY_MST_CHK,
				                     work->work_group,0x1d,0,0,0,NULL,NULL,
				                     True,False,d->bcast_ip,d->bcast_ip);
				}
			}
		}
	}
}


/*******************************************************************
  what to do if a master browser DOESN't exist
  ******************************************************************/
void browser_gone(char *work_name, struct in_addr ip)
{
  struct subnet_record *d = find_subnet(ip);
  struct work_record *work = find_workgroupstruct(d, work_name, False);

  /* i don't know about this workgroup, therefore i don't care */
  if (!work || !d) return;

  /* don't do election stuff on the WINS subnet */
  if (ip_equal(d->bcast_ip,wins_ip)) 
    return;

  if (strequal(work->work_group, lp_workgroup()))
  {

      DEBUG(2,("Forcing election on %s %s\n",
	       work->work_group,inet_ntoa(d->bcast_ip)));

      /* we can attempt to become master browser */
      work->needelection = True;
  }
  else
  {
     /* local interfaces: force an election */
    send_election(d, work->work_group, 0, 0, myname);

     /* only removes workgroup completely on a local interface 
        persistent lmhosts entries on a local interface _will_ be removed).
      */
     remove_workgroup(d, work,True);
  }
}


/****************************************************************************
  send an election packet
  **************************************************************************/
void send_election(struct subnet_record *d, char *group,uint32 criterion,
		   int timeup,char *name)
{
  pstring outbuf;
  char *p;

  if (!d) return;
  
  DEBUG(2,("Sending election to %s for workgroup %s\n",
	   inet_ntoa(d->bcast_ip),group));	   

  bzero(outbuf,sizeof(outbuf));
  p = outbuf;
  CVAL(p,0) = ANN_Election; /* election */
  p++;

  CVAL(p,0) = (criterion == 0 && timeup == 0) ? 0 : ELECTION_VERSION;
  SIVAL(p,1,criterion);
  SIVAL(p,5,timeup*1000); /* ms - despite the spec */
  p += 13;
  strcpy(p,name);
  strupper(p);
  p = skip_string(p,1);
  
  send_mailslot_reply(False,BROWSE_MAILSLOT,ClientDGRAM,
              outbuf,PTR_DIFF(p,outbuf),
		      name,group,0,0x1e,d->bcast_ip,*iface_ip(d->bcast_ip));
}


/****************************************************************************
  un-register a SELF name that got rejected.

  if this name happens to be rejected when samba is in the process
  of becoming a master browser (registering __MSBROWSE__, WORKGROUP(1d)
  or WORKGROUP(1b)) then we must stop being a master browser. sad.

  **************************************************************************/
void name_unregister_work(struct subnet_record *d, char *name, int name_type)
{
    struct work_record *work;
    int remove_type_local  = 0;
    int remove_type_domain = 0;
    int remove_type_logon  = 0;

    remove_netbios_name(d,name,name_type,SELF,ipzero);

    if (!(work = find_workgroupstruct(d, name, False))) return;

    /* work out what to unbecome, from the name type being removed */

    if (ms_browser_name(name, name_type))
    {
      remove_type_local |= SV_TYPE_MASTER_BROWSER;
    }
    if (AM_MASTER(work) && strequal(name, lp_workgroup()) && name_type == 0x1d)
    {
      remove_type_local |= SV_TYPE_MASTER_BROWSER;
    }
    if (AM_DOMMST(work) && strequal(name, lp_workgroup()) && name_type == 0x1b)
    {
      remove_type_domain |= SV_TYPE_DOMAIN_MASTER;
    }
    if (AM_DOMMEM(work) && strequal(name, lp_workgroup()) && name_type == 0x1c)
    {
      remove_type_logon|= SV_TYPE_DOMAIN_MEMBER;
    }

    if (remove_type_local ) unbecome_local_master (d, work, remove_type_local );
    if (remove_type_domain) unbecome_domain_master(d, work, remove_type_domain);
    if (remove_type_logon ) unbecome_logon_server (d, work, remove_type_logon );
}


/****************************************************************************
  registers a name.

  if the name being added is a SELF name, we must additionally check
  whether to proceed to the next stage in samba becoming a master browser.

  **************************************************************************/
void name_register_work(struct subnet_record *d, char *name, int name_type,
				int nb_flags, time_t ttl, struct in_addr ip, BOOL bcast)
{
	enum name_source source = (ismyip(ip) || ip_equal(ip, ipzero)) ?
	                          SELF : REGISTER;

	if (source == SELF)
	{
		struct work_record *work = find_workgroupstruct(d, lp_workgroup(), False);

		add_netbios_entry(d,name,name_type,nb_flags,ttl,source,ip,True,!bcast);

		if (work)
		{
			int add_type_local  = False;
			int add_type_domain = False;
			int add_type_logon  = False;

			DEBUG(4,("checking next stage: name_register_work %s\n", name));

			/* work out what to become, from the name type being added */

			if (ms_browser_name(name, name_type))
			{
				add_type_local = True;
			}
			if (strequal(name, lp_workgroup()) && name_type == 0x1d)
			{
				add_type_local = True;
			}
			if (strequal(name, lp_workgroup()) && name_type == 0x1b)
			{
				add_type_domain = True;
			}
			if (strequal(name, lp_workgroup()) && name_type == 0x1c)
			{
				add_type_logon = True;
			}

			if (add_type_local ) become_local_master (d, work);
			if (add_type_domain) become_domain_master(d, work);
			if (add_type_logon ) become_logon_server (d, work);
		}
	}
}


/*******************************************************************
  become the local master browser.

  this is done in stages. note that this could take a while, 
  particularly on a broadcast subnet, as we have to wait for
  the implicit registration of each name to be accepted.

  as each name is successfully registered, become_local_master() is
  called again, in order to initiate the next stage. see
  dead_netbios_entry() - deals with implicit name registration
  and response_name_reg() - deals with explicit registration
  with a WINS server.

  stage 1: was MST_POTENTIAL - go to MST_POTENTIAL and register ^1^2__MSBROWSE__^2^1.
  stage 2: was MST_BACK  - go to MST_MSB  and register WORKGROUP(0x1d)
  stage 3: was MST_MSB  - go to MST_BROWSER and stay there 

  XXXX note: this code still does not cope with the distinction
  between different types of nodes, particularly between M and P
  nodes. that comes later.

  ******************************************************************/
void become_local_master(struct subnet_record *d, struct work_record *work)
{
  /* domain type must be limited to domain enum + server type. it must
     not have SV_TYPE_SERVER or anything else with SERVER in it, else
     clients get confused and start thinking this entry is a server
     not a workgroup
   */
  uint32 domain_type = SV_TYPE_DOMAIN_ENUM|SV_TYPE_NT;

  if (!work || !d) return;
  
  DEBUG(2,("Becoming master for %s %s (currently at stage %d)\n",
					work->work_group,inet_ntoa(d->bcast_ip),work->mst_state));
  
  switch (work->mst_state)
  {
    case MST_POTENTIAL: /* while we were nothing but a server... */
    {
      DEBUG(3,("go to first stage: register ^1^2__MSBROWSE__^2^1\n"));
      work->mst_state = MST_BACK; /* ... an election win was successful */

      work->ElectionCriterion |= 0x5;

      /* update our server status */
      work->ServerType &= ~SV_TYPE_POTENTIAL_BROWSER;
      add_server_entry(d,work,myname,work->ServerType,0,lp_serverstring(),True);

      /* add special browser name */
      add_my_name_entry(d,MSBROWSE        ,0x01,nb_type|NB_ACTIVE|NB_GROUP);

      /* DON'T do anything else after calling add_my_name_entry() */
      break;
    }

    case MST_BACK: /* while nothing had happened except we won an election... */
    {
      DEBUG(3,("go to second stage: register as master browser\n"));
      work->mst_state = MST_MSB; /* ... registering MSBROWSE was successful */

      /* add server entry on successful registration of MSBROWSE */
      add_server_entry(d,work,work->work_group,domain_type,0,myname,True);

      /* add master name */
      add_my_name_entry(d,work->work_group,0x1d,nb_type|NB_ACTIVE);
  
      /* DON'T do anything else after calling add_my_name_entry() */
      break;
    }

    case MST_MSB: /* while we were still only registered MSBROWSE state... */
    {
      DEBUG(3,("2nd stage complete: registered as master browser\n"));
      work->mst_state = MST_BROWSER; /* ... registering WORKGROUP(1d) succeeded */

      /* update our server status */
      work->ServerType |= SV_TYPE_MASTER_BROWSER;

      DEBUG(3,("become_local_master: updating our server %s to type %x\n", myname, work->ServerType));

      add_server_entry(d,work,myname,work->ServerType,0,lp_serverstring(),True);

      if (work->serverlist == NULL) /* no servers! */
      {
        /* ask all servers on our local net to announce to us */
        /* XXXX OOPS! add_server_entry will always add one entry - our own. */
        announce_request(work, d->bcast_ip);
      }
      break;
    }

    case MST_BROWSER:
    {
      /* don't have to do anything: just report success */
      DEBUG(3,("3rd stage: become master browser!\n"));

      break;
    }
  }
}


/*******************************************************************
  become the domain master browser.

  this is done in stages. note that this could take a while, 
  particularly on a broadcast subnet, as we have to wait for
  the implicit registration of each name to be accepted.

  as each name is successfully registered, become_domain_master() is
  called again, in order to initiate the next stage. see
  dead_netbios_entry() - deals with implicit name registration
  and response_name_reg() - deals with explicit registration
  with a WINS server.

  stage 1: was DOMAIN_NONE - go to DOMAIN_MST 

  XXXX note: this code still does not cope with the distinction
  between different types of nodes, particularly between M and P
  nodes. that comes later.

  ******************************************************************/
void become_domain_master(struct subnet_record *d, struct work_record *work)
{
  /* domain type must be limited to domain enum + server type. it must
     not have SV_TYPE_SERVER or anything else with SERVER in it, else
     clients get confused and start thinking this entry is a server
     not a workgroup
   */

  if (!work || !d) return;
  
  DEBUG(2,("Becoming domain master for %s %s (currently at stage %d)\n",
					work->work_group,inet_ntoa(d->bcast_ip),work->dom_state));
  
  switch (work->dom_state)
  {
    case DOMAIN_NONE: /* while we were nothing but a server... */
    {
      if (lp_domain_master())
      {
		  DEBUG(3,("go to first stage: register <1b> name\n"));
		  work->dom_state = DOMAIN_WAIT;

		  /* XXXX the 0x1b is domain master browser name */
		  add_my_name_entry(d, lp_workgroup(),0x1b,nb_type|NB_ACTIVE|NB_GROUP);

		  /* DON'T do anything else after calling add_my_name_entry() */
		  break;
      }
      else
      {
        DEBUG(4,("samba not configured as a domain master.\n"));
      }
  
      break;
    }

   case DOMAIN_WAIT:
   {
      if (lp_domain_master())
      {
        work->dom_state = DOMAIN_MST; /* ... become domain master */
        DEBUG(3,("domain first stage: register as domain member\n"));
 
        /* update our server status */
        work->ServerType |= SV_TYPE_NT|SV_TYPE_DOMAIN_MASTER;
        add_server_entry(d,work,myname,work->ServerType,0,
                         lp_serverstring(),True);

        DEBUG(4,("samba is now a domain master\n"));

        break;
      }
      else
      {
        DEBUG(4,("samba not configured as a domain master.\n"));
      }
  
      break;
   }

    case DOMAIN_MST:
    {
      /* don't have to do anything: just report success */
      DEBUG(3,("domain second stage: there isn't one!\n"));
      break;
    }
  }
}


/*******************************************************************
  become a logon server.
  ******************************************************************/
void become_logon_server(struct subnet_record *d, struct work_record *work)
{
  if (!work || !d) return;
  
  DEBUG(2,("Becoming logon server for %s %s (currently at stage %d)\n",
					work->work_group,inet_ntoa(d->bcast_ip),work->log_state));
  
  switch (work->log_state)
  {
    case LOGON_NONE: /* while we were nothing but a server... */
    {
      if (lp_domain_logons())
      {
		  DEBUG(3,("go to first stage: register <1c> name\n"));
		  work->log_state = LOGON_WAIT;

          /* XXXX the 0x1c is apparently something to do with domain logons */
          add_my_name_entry(d, lp_workgroup(),0x1c,nb_type|NB_ACTIVE|NB_GROUP);

		  /* DON'T do anything else after calling add_my_name_entry() */
		  break;
      }
      {
        DEBUG(4,("samba not configured as a logon master.\n"));
      }
  
      break;
    }

   case LOGON_WAIT:
   {
      if (lp_domain_logons())
      {
        work->log_state = LOGON_SRV; /* ... become logon server */
        DEBUG(3,("logon second stage: register \n"));
 
        /* update our server status */
        work->ServerType |= SV_TYPE_NT|SV_TYPE_DOMAIN_MEMBER;
        add_server_entry(d,work,myname,work->ServerType,0,
                         lp_serverstring(),True);

        /* DON'T do anything else after calling add_my_name_entry() */
        break;
      }
      else
      {
        DEBUG(4,("samba not configured as a logon server.\n"));
      }
  
      break;
   }

   case LOGON_SRV:
   {
      DEBUG(3,("logon third stage: there isn't one!\n"));
      break;
   }

  }
}


/*******************************************************************
  unbecome the local master browser. initates removal of necessary netbios 
  names, and tells the world that we are no longer a master browser.

  XXXX this _should_ be used to demote to a backup master browser, without
  going straight to non-master browser.  another time.

  ******************************************************************/
void unbecome_local_master(struct subnet_record *d, struct work_record *work,
				int remove_type)
{
  int new_server_type = work->ServerType;

  /* can only remove master types with this function */
  remove_type &= SV_TYPE_MASTER_BROWSER;

  new_server_type &= ~remove_type;

  if (remove_type)
  {
    DEBUG(2,("Becoming local non-master for %s\n",work->work_group));
  
    /* no longer a master browser of any sort */

    work->ServerType |= SV_TYPE_POTENTIAL_BROWSER;
    work->ElectionCriterion &= ~0x4;
    work->mst_state = MST_POTENTIAL;

	/* announce ourselves as no longer active as a master browser. */
    announce_server(d, work, work->work_group, myname, 0, 0);
    remove_name_entry(d,MSBROWSE        ,0x01);
    remove_name_entry(d,work->work_group,0x1d);
  }
}


/*******************************************************************
  unbecome the domain master browser. initates removal of necessary netbios 
  names, and tells the world that we are no longer a domain browser.
  ******************************************************************/
void unbecome_domain_master(struct subnet_record *d, struct work_record *work,
				int remove_type)
{
  int new_server_type = work->ServerType;

  DEBUG(2,("Becoming domain non-master for %s\n",work->work_group));
  
  /* can only remove master or domain types with this function */
  remove_type &= SV_TYPE_DOMAIN_MASTER;

  new_server_type &= ~remove_type;

  if (remove_type)
  {
    /* no longer a domain master browser of any sort */

    work->dom_state = DOMAIN_NONE;

	/* announce ourselves as no longer active as a master browser. */
    announce_server(d, work, work->work_group, myname, 0, 0);
    remove_name_entry(d,work->work_group,0x1b);    
  }
}


/*******************************************************************
  unbecome the logon server. initates removal of necessary netbios 
  names, and tells the world that we are no longer a logon server.
  ******************************************************************/
void unbecome_logon_server(struct subnet_record *d, struct work_record *work,
				int remove_type)
{
  int new_server_type = work->ServerType;

  DEBUG(2,("Becoming logon non-server for %s\n",work->work_group));
  
  /* can only remove master or domain types with this function */
  remove_type &= SV_TYPE_DOMAIN_MEMBER;

  new_server_type &= ~remove_type;

  if (remove_type)
  {
    /* no longer a master browser of any sort */

    work->log_state = LOGON_NONE;

	/* announce ourselves as no longer active as a master browser. */
    announce_server(d, work, work->work_group, myname, 0, 0);
    remove_name_entry(d,work->work_group,0x1c);    
  }
}


/*******************************************************************
  run the election
  ******************************************************************/
void run_elections(time_t t)
{
  static time_t lastime = 0;
  
  struct subnet_record *d;
  
  /* send election packets once a second */
  if (lastime && t-lastime <= 0) return;
  
  lastime = t;
  
  for (d = subnetlist; d; d = d->next)
  {
    struct work_record *work;

    if(ip_equal(d->bcast_ip, wins_ip)) 
      {
        /* WINS ip */
        DEBUG(10,("run_elections: ignoring WINS subnet\n"));
        continue;
      }

    for (work = d->workgrouplist; work; work = work->next)
	{
	  if (work->RunningElection)
	  {
	    send_election(d,work->work_group, work->ElectionCriterion,
			    t-StartupTime,myname);
	      
	    if (work->ElectionCount++ >= 4)
		{
		  /* I won! now what :-) */
		  DEBUG(2,(">>> Won election on %s %s <<<\n",
			   work->work_group,inet_ntoa(d->bcast_ip)));
		  
		  work->RunningElection = False;
		  work->mst_state = MST_POTENTIAL;

		  become_local_master(d, work);
		}
	  }
	}
  }
}


/*******************************************************************
  work out if I win an election
  ******************************************************************/
static BOOL win_election(struct work_record *work,int version,uint32 criterion,
			 int timeup,char *name)
{  
  int mytimeup = time(NULL) - StartupTime;
  uint32 mycriterion = work->ElectionCriterion;

  DEBUG(4,("election comparison: %x:%x %x:%x %d:%d %s:%s\n",
	   version,ELECTION_VERSION,
	   criterion,mycriterion,
	   timeup,mytimeup,
	   name,myname));

  if (version > ELECTION_VERSION) return(False);
  if (version < ELECTION_VERSION) return(True);
  
  if (criterion > mycriterion) return(False);
  if (criterion < mycriterion) return(True);

  if (timeup > mytimeup) return(False);
  if (timeup < mytimeup) return(True);

  if (strcasecmp(myname,name) > 0) return(False);
  
  return(True);
}


/*******************************************************************
  process a election packet

  An election dynamically decides who will be the master. 
  ******************************************************************/
void process_election(struct packet_struct *p,char *buf)
{
  struct dgram_packet *dgram = &p->packet.dgram;
  struct in_addr ip = dgram->header.source_ip;
  struct subnet_record *d = find_subnet(ip);
  int version = CVAL(buf,0);
  uint32 criterion = IVAL(buf,1);
  int timeup = IVAL(buf,5)/1000;
  char *name = buf+13;
  struct work_record *work;

  if (!d) return;

  if (ip_equal(d->bcast_ip,wins_ip)) {
    DEBUG(3,("Unexpected election request from %s %s on WINS net\n",
	     name, inet_ntoa(p->ip)));
    return;
  }
  
  name[15] = 0;  

  DEBUG(3,("Election request from %s %s vers=%d criterion=%08x timeup=%d\n",
	   name,inet_ntoa(p->ip),version,criterion,timeup));
  
  if (same_context(dgram)) return;
  
  for (work = d->workgrouplist; work; work = work->next)
    {
      if (!strequal(work->work_group, lp_workgroup()))
	continue;

      if (win_election(work, version,criterion,timeup,name)) {
	if (!work->RunningElection) {
	  work->needelection = True;
	  work->ElectionCount=0;
	  work->mst_state = MST_POTENTIAL;
	}
      } else {
	work->needelection = False;
	  
	if (work->RunningElection || AM_MASTER(work)) {
	  work->RunningElection = False;
	  DEBUG(3,(">>> Lost election on %s %s <<<\n",
		   work->work_group,inet_ntoa(d->bcast_ip)));
	  if (AM_MASTER(work))
	    unbecome_local_master(d, work, SV_TYPE_MASTER_BROWSER);
	}
      }
    }
}


/****************************************************************************
  checks whether a browser election is to be run on any workgroup

  this function really ought to return the time between election
  packets (which depends on whether samba intends to be a domain
  master or a master browser) in milliseconds.

  ***************************************************************************/
BOOL check_elections(void)
{
  struct subnet_record *d;
  BOOL run_any_election = False;

  for (d = subnetlist; d; d = d->next)
    {
      struct work_record *work;
      for (work = d->workgrouplist; work; work = work->next)
	{
	  run_any_election |= work->RunningElection;
	  
	  if (work->needelection && !work->RunningElection)
	    {
	      DEBUG(3,(">>> Starting election on %s %s <<<\n",
		       work->work_group,inet_ntoa(d->bcast_ip)));
	      work->ElectionCount = 0;
	      work->RunningElection = True;
	      work->needelection = False;
	    }
	}
    }
  return run_any_election;
}