summaryrefslogtreecommitdiff
path: root/source3/nameserv.c
blob: b6bc8a4f06085c5e448b28a23695b1d4dc0ce0a5 (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
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
/* 
   Unix SMB/Netbios implementation.
   Version 1.9.
   NBT netbios routines and daemon - version 2
   Copyright (C) Andrew Tridgell 1994-1995
   
   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"
#include "loadparm.h"
#include "localnet.h"


enum name_search { FIND_SELF, FIND_GLOBAL };

extern int DEBUGLEVEL;

extern pstring scope;
extern BOOL CanRecurse;
extern pstring myname;
extern struct in_addr ipzero;

/* netbios names database */
struct name_record *namelist;

#define GET_TTL(ttl) ((ttl)?MIN(ttl,lp_max_ttl()):lp_max_ttl())


/****************************************************************************
  true if two netbios names are equal
****************************************************************************/
static BOOL name_equal(struct nmb_name *n1,struct nmb_name *n2)
{
  if (n1->name_type != n2->name_type) return(False);

  return(strequal(n1->name,n2->name) && strequal(n1->scope,n2->scope));
}

/****************************************************************************
  add a netbios name into the namelist
  **************************************************************************/
static void add_name(struct name_record *n)
{
  struct name_record *n2;

  if (!namelist)
  {
    namelist = n;
    n->prev = NULL;
    n->next = NULL;
    return;
  }

  for (n2 = namelist; n2->next; n2 = n2->next) ;

  n2->next = n;
  n->next = NULL;
  n->prev = n2;
}

/****************************************************************************
  remove a name from the namelist. The pointer must be an element just 
  retrieved
  **************************************************************************/
void remove_name(struct name_record *n)
{
  struct name_record *nlist = namelist;

  while (nlist && nlist != n) nlist = nlist->next;

  if (nlist)
  {
    if (nlist->next) nlist->next->prev = nlist->prev;
    if (nlist->prev) nlist->prev->next = nlist->next;
    free(nlist);
  }
}

/****************************************************************************
  find a name in the domain database namelist 
  search can be:
  FIND_SELF   - look for names the samba server has added for itself
  FIND_GLOBAL - the name can be anyone. first look on the client's
                subnet, then the server's subnet, then all subnets.
  **************************************************************************/
static struct name_record *find_name_search(struct nmb_name *name, enum name_search search,
					    struct in_addr ip)
{
	struct name_record *ret;

	/* any number of winpopup names can be added. must search by ip as well */
	if (name->name_type != 0x3) ip = ipzero;

	for (ret = namelist; ret; ret = ret->next)
	{
		if (name_equal(&ret->name,name))
		{
			/* self search: self names only */
			if (search == FIND_SELF && ret->source != SELF) continue;

			if (zero_ip(ip) || ip_equal(ip, ret->ip))
			{
				return ret;
			}
		}
	}

	return NULL;
}


/****************************************************************************
  dump a copy of the name table
  **************************************************************************/
void dump_names(void)
{
	struct name_record *n;
	time_t t = time(NULL);

	DEBUG(3,("Dump of local name table:\n"));

	for (n = namelist; n; n = n->next)
	{
		DEBUG(3,("%s %s TTL=%d NBFLAGS=%2x\n",
		        namestr(&n->name),
		        inet_ntoa(n->ip),
		        n->death_time?n->death_time-t:0,
				n->nb_flags));
	}
}


/****************************************************************************
  remove an entry from the name list
  ****************************************************************************/
void remove_netbios_name(char *name,int type, enum name_source source,
			 struct in_addr ip)
{
	struct nmb_name nn;
	struct name_record *n;

	make_nmb_name(&nn, name, type, scope);
	n = find_name_search(&nn, FIND_GLOBAL, ip);

	if (n && n->source == source) remove_name(n);
}


/****************************************************************************
  add an entry to the name list
  ****************************************************************************/
struct name_record *add_netbios_entry(char *name, int type, int nb_flags, int ttl,
				      enum name_source source, struct in_addr ip)
{
  struct name_record *n;
  struct name_record *n2=NULL;

  n = (struct name_record *)malloc(sizeof(*n));
  if (!n) return(NULL);

  bzero((char *)n,sizeof(*n));

  make_nmb_name(&n->name,name,type,scope);

  if ((n2 = find_name_search(&n->name, FIND_GLOBAL, ip)))
  {
    free(n);
    n = n2;
  }

  if (ttl) n->death_time = time(NULL)+ttl*3;
  n->ip = ip;
  n->nb_flags = nb_flags;
  n->source = source;
  
  if (!n2) add_name(n);

  DEBUG(3,("Added netbios name %s at %s ttl=%d nb_flags=%2x\n",
	        namestr(&n->name),inet_ntoa(ip),ttl,nb_flags));

  return(n);
}


/****************************************************************************
  remove an entry from the name list
  ****************************************************************************/
void remove_name_entry(char *name,int type)
{
  if (lp_wins_support())
    {
      /* we are a WINS server. */
      remove_netbios_name(name,type,SELF,myip);
    }
  else
    {
      struct in_addr ip;
      ip = ipzero;
      
      queue_netbios_pkt_wins(ClientNMB,NMB_REL,NAME_RELEASE,
			     name, type, 0,
			     False, True, ip);
    }
}


/****************************************************************************
  add an entry to the name list
  ****************************************************************************/
void add_name_entry(char *name,int type,int nb_flags)
{
  /* always add our own entries */
  add_netbios_entry(name,type,nb_flags,0,SELF,myip);

  if (!lp_wins_support())
    {
      struct in_addr ip;
      ip = ipzero;
      
      queue_netbios_pkt_wins(ClientNMB,NMB_REG,NAME_REGISTER,
			     name, type, nb_flags,
			     False, True, ip);
    }
}


/****************************************************************************
  add the magic samba names, useful for finding samba servers
  **************************************************************************/
void add_my_names(void)
{
  struct in_addr ip;

  ip = ipzero;
  
  add_name_entry(myname,0x20,NB_ACTIVE);
  add_name_entry(myname,0x03,NB_ACTIVE);
  add_name_entry(myname,0x00,NB_ACTIVE);
  add_name_entry(myname,0x1f,NB_ACTIVE);
  
  add_netbios_entry("*",0x0,NB_ACTIVE,0,SELF,ip);
  add_netbios_entry("__SAMBA__",0x20,NB_ACTIVE,0,SELF,ip);
  add_netbios_entry("__SAMBA__",0x00,NB_ACTIVE,0,SELF,ip);
  
  if (lp_wins_support()) {
    add_netbios_entry(inet_ntoa(myip),0x01,NB_ACTIVE,0,SELF,ip); /* nt as? */
  }
}

/*******************************************************************
  refresh my own names
  ******************************************************************/
void refresh_my_names(time_t t)
{
  static time_t lasttime = 0;

  if (t - lasttime < REFRESH_TIME) 
    return;
  lasttime = t;

  add_my_names();
}

/*******************************************************************
  expires old names in the namelist
  ******************************************************************/
void expire_names(time_t t)
{
  struct name_record *n;
  struct name_record *next;
  
  /* expire old names */
  for (n = namelist; n; n = next)
    {
      if (n->death_time && n->death_time < t)
	{
	  DEBUG(3,("Removing dead name %s\n", namestr(&n->name)));
	  
	  next = n->next;
	  
	  if (n->prev) n->prev->next = n->next;
	  if (n->next) n->next->prev = n->prev;
	  
	  if (namelist == n) namelist = n->next; 
	  
	  free(n);
	}
      else
	{
	  next = n->next;
	}
    }
}


/****************************************************************************
response for a reg release received
**************************************************************************/
void response_name_release(struct packet_struct *p)
{
  struct nmb_packet *nmb = &p->packet.nmb;
  char *name = nmb->question.question_name.name;
  int   type = nmb->question.question_name.name_type;
  
  DEBUG(4,("response name release received\n"));
  
  if (nmb->header.rcode == 0 && nmb->answers->rdata)
    {
      struct in_addr found_ip;
      putip((char*)&found_ip,&nmb->answers->rdata[2]);
      
      if (ip_equal(found_ip, myip))
	{
	  remove_netbios_name(name,type,SELF,found_ip);
	}
    }
  else
    {
      DEBUG(1,("name registration for %s rejected!\n",
	       namestr(&nmb->question.question_name)));
    }
}


/****************************************************************************
reply to a name release
****************************************************************************/
void reply_name_release(struct packet_struct *p)
{
  struct nmb_packet *nmb = &p->packet.nmb;
  struct in_addr ip;
  int rcode=0;
  int opcode = nmb->header.opcode;  
  int nb_flags = nmb->additional->rdata[0];
  BOOL bcast = nmb->header.nm_flags.bcast;
  struct name_record *n;
  char rdata[6];
  
  putip((char *)&ip,&nmb->additional->rdata[2]);  
  
  DEBUG(3,("Name release on name %s rcode=%d\n",
	   namestr(&nmb->question.question_name),rcode));
  
  n = find_name_search(&nmb->question.question_name, FIND_GLOBAL, ip);
  
  /* XXXX under what conditions should we reject the removal?? */
  if (n && n->nb_flags == nb_flags && ip_equal(n->ip,ip))
    {
      /* success = True;
	 rcode = 6; */
      
      remove_name(n);
      n = NULL;
    }
  
  if (bcast) return;
  
  /*if (success)*/
  {
    rdata[0] = nb_flags;
    rdata[1] = 0;
    putip(&rdata[2],(char *)&ip);
  }
  
  /* Send a NAME RELEASE RESPONSE */
  reply_netbios_packet(p,nmb->header.name_trn_id,rcode,opcode,
		       &nmb->question.question_name,
		       nmb->question.question_type,
		       nmb->question.question_class,
		       0,
		       rdata, 6 /*success ? 6 : 0*/);
  /* XXXX reject packet never tested: cannot tell what to do */
}


/****************************************************************************
response for a reg request received
**************************************************************************/
void response_name_reg(struct packet_struct *p)
{
  struct nmb_packet *nmb = &p->packet.nmb;
  char *name = nmb->question.question_name.name;
  int   type = nmb->question.question_name.name_type;
  
  DEBUG(4,("response name registration received!\n"));
  
  if (nmb->header.rcode == 0 && nmb->answers->rdata)
    {
      int nb_flags = nmb->answers->rdata[0];
      struct in_addr found_ip;
      int ttl = nmb->answers->ttl;
      enum name_source source = REGISTER;
      
      putip((char*)&found_ip,&nmb->answers->rdata[2]);
      
      if (ip_equal(found_ip, myip)) source = SELF;
      
      add_netbios_entry(name,type,nb_flags,ttl,source,found_ip);
    }
  else
    {
      DEBUG(1,("name registration for %s rejected!\n",
	       namestr(&nmb->question.question_name)));
    }
}


/****************************************************************************
reply to a reg request
**************************************************************************/
void reply_name_reg(struct packet_struct *p)
{
  struct nmb_packet *nmb = &p->packet.nmb;
  struct nmb_name *question = &nmb->question.question_name;
  char *qname = nmb->question.question_name.name;
  int name_type = nmb->question.question_name.name_type;
  
  BOOL bcast = nmb->header.nm_flags.bcast;
  
  int ttl = GET_TTL(nmb->additional->ttl);
  int nb_flags = nmb->additional->rdata[0];
  BOOL group = (nb_flags&0x80);
  int rcode = 0;  
  int opcode = nmb->header.opcode;  
  struct name_record *n = NULL;
  int success = True;
  char rdata[6];
  struct in_addr ip, from_ip;
  
  putip((char *)&from_ip,&nmb->additional->rdata[2]);
  ip = from_ip;
  
  DEBUG(3,("Name registration for name %s at %s rcode=%d\n",
	   namestr(question),inet_ntoa(ip),rcode));
  
  if (group)
    {
      /* apparently we should return 255.255.255.255 for group queries
	 (email from MS) */
      ip = *interpret_addr2("255.255.255.255");
    }
  
  /* see if the name already exists */
  n = find_name_search(question, FIND_GLOBAL, from_ip);
  
  if (n)
    {
      if (!group && !ip_equal(ip,n->ip) && question->name_type != 0x3)
	{
	  if (n->source == SELF)
	    {
	      rcode = 6;
	      success = False;
	    }
	  else
	    {
	      n->ip = ip;
	      n->death_time = ttl?p->timestamp+ttl*3:0;
	      DEBUG(3,("%s changed owner to %s\n",
		       namestr(&n->name),inet_ntoa(n->ip)));
	    }
	}
      else
	{
	  /* refresh the name */
	  if (n->source != SELF)
	    {
	      n->death_time = ttl?p->timestamp + ttl*3:0;
	    }
	}
    }
  else
    {
      /* add the name to our subnet/name database */
      n = add_netbios_entry(qname,name_type,nb_flags,ttl,REGISTER,ip);
    }
  
  if (bcast) return;
  
  update_from_reg(nmb->question.question_name.name,
		  nmb->question.question_name.name_type, from_ip);
  
  /* XXXX don't know how to reject a name register: stick info in anyway
     and guess that it doesn't matter if info is there! */
  /*if (success)*/
  {
    rdata[0] = nb_flags;
    rdata[1] = 0;
    putip(&rdata[2],(char *)&ip);
  }
  
  /* Send a NAME REGISTRATION RESPONSE */
  reply_netbios_packet(p,nmb->header.name_trn_id,rcode,opcode,
		       &nmb->question.question_name,
		       nmb->question.question_type,
		       nmb->question.question_class,
		       ttl,
		       rdata, 6 /*success ? 6 : 0*/);
}


/****************************************************************************
reply to a name status query
****************************************************************************/
void reply_name_status(struct packet_struct *p)
{
  struct nmb_packet *nmb = &p->packet.nmb;
  char *qname   = nmb->question.question_name.name;
  int ques_type = nmb->question.question_name.name_type;
  BOOL wildcard = (qname[0] == '*'); 
  char rdata[MAX_DGRAM_SIZE];
  char *countptr, *buf;
  int count, names_added;
  struct name_record *n;
  
  DEBUG(3,("Name status for name %s %s\n",
	   namestr(&nmb->question.question_name), inet_ntoa(p->ip)));
  
  /* find a name: if it's a wildcard, search the entire database.
     if not, search for source SELF names only */
  n = find_name_search(&nmb->question.question_name,
		       wildcard ? FIND_GLOBAL : FIND_SELF, p->ip);
  
  if (!wildcard && (!n || n->source != SELF)) return;
  
  for (count=0, n = namelist ; n; n = n->next)
    {
      int name_type = n->name.name_type;
      
      if (n->source != SELF) continue;
      
      if (name_type >= 0x1b && name_type <= 0x20 && 
	  ques_type >= 0x1b && ques_type <= 0x20)
	{
	  if (!strequal(qname, n->name.name)) continue;
	}
      
      count++;
    }
  
  /* XXXX hack, we should calculate exactly how many will fit */
  count = MIN(count,(sizeof(rdata) - 64) / 18);
  
  countptr = buf = rdata;
  buf += 1;
  
  names_added = 0;
  
  for (n = namelist ; n && count >= 0; n = n->next) 
    {
      int name_type = n->name.name_type;
      
      if (n->source != SELF) continue;
      
      /* start with first bit of putting info in buffer: the name */
      
      bzero(buf,18);
      StrnCpy(buf,n->name.name,15);
      strupper(buf);
      
      /* now check if we want to exclude other workgroup names
	 from the response. if we don't exclude them, windows clients
	 get confused and will respond with an error for NET VIEW */
      
      if (name_type >= 0x1b && name_type <= 0x20 && 
	  ques_type >= 0x1b && ques_type <= 0x20)
	{
	  if (!strequal(qname, n->name.name)) continue;
	}
      
      /* carry on putting name info in buffer */
      
      buf[15] = name_type;
      buf[16]  = n->nb_flags;
      
      buf += 18;
      
      count--;
      names_added++;
    }
  
  if (count < 0)
    {
      DEBUG(3, (("too many names: missing a few!\n")));
    }
  
  SCVAL(countptr,0,names_added);
  
  /* XXXXXXX we should fill in more fields of the statistics structure */
  bzero(buf,64);
  {
    extern int num_good_sends,num_good_receives;
    SIVAL(buf,20,num_good_sends);
    SIVAL(buf,24,num_good_receives);
  }
  
  SIVAL(buf,46,0xFFB8E5); /* undocumented - used by NT */
  
  buf += 64;
  
  /* Send a POSITIVE NAME STATUS RESPONSE */
  reply_netbios_packet(p,nmb->header.name_trn_id,0,0,
		       &nmb->question.question_name,
		       nmb->question.question_type,
		       nmb->question.question_class,
		       0,
		       rdata,PTR_DIFF(buf,rdata));
}


/***************************************************************************
reply to a name query
****************************************************************************/
struct name_record *search_for_name(struct nmb_name *question,
				    struct in_addr ip, int Time, int search)
{
  int name_type = question->name_type;
  char *qname = question->name;
  BOOL dns_type = name_type == 0x20 || name_type == 0;
  
  struct name_record *n;
  
  DEBUG(3,("Search for %s from %s - ", namestr(question), inet_ntoa(ip)));
  
  /* first look up name in cache */
  n = find_name_search(question,search,ip);
  
  /* now try DNS lookup. */
  if (!n)
    {
      struct in_addr dns_ip;
      unsigned long a;
      
      /* only do DNS lookups if the query is for type 0x20 or type 0x0 */
      if (!dns_type)
	{
	  DEBUG(3,("types 0x20 0x1b 0x0 only: name not found\n"));
	  return NULL;
	}
      
      /* look it up with DNS */      
      a = interpret_addr(qname);
      
      putip((char *)&dns_ip,(char *)&a);
      
      if (!a)
	{
	  /* no luck with DNS. We could possibly recurse here XXXX */
	  /* if this isn't a bcast then we should send a negative reply XXXX */
	  DEBUG(3,("no recursion\n"));
	  add_netbios_entry(qname,name_type,NB_ACTIVE,60*60,DNSFAIL,dns_ip);
	  return NULL;
	}
      
      /* add it to our cache of names. give it 2 hours in the cache */
      n = add_netbios_entry(qname,name_type,NB_ACTIVE,2*60*60,DNS,dns_ip);
      
      /* failed to add it? yikes! */
      if (!n) return NULL;
    }
  
  /* is our entry already dead? */
  if (n->death_time)
    {
      if (n->death_time < Time) return False;
    }
  
  /* it may have been an earlier failure */
  if (n->source == DNSFAIL)
    {
      DEBUG(3,("DNSFAIL\n"));
      return NULL;
    }
  
  DEBUG(3,("OK %s\n",inet_ntoa(n->ip)));      
  
  return n;
}


/***************************************************************************
reply to a name query.

with broadcast name queries:

	- only reply if the query is for one of YOUR names. all other machines on
	  the network will be doing the same thing (that is, only replying to a
	  broadcast query if they own it)
	  NOTE: broadcast name queries should only be sent out by a machine
	  if they HAVEN'T been configured to use WINS. this is generally bad news
	  in a wide area tcp/ip network and should be rectified by the systems
	  administrator. USE WINS! :-)
	- the exception to this is if the query is for a Primary Domain Controller
	  type name (0x1b), in which case, a reply is sent.

	- NEVER send a negative response to a broadcast query. no-one else will!

with directed name queries:

	- if you are the WINS server, you are expected to 
****************************************************************************/
extern void reply_name_query(struct packet_struct *p)
{
  struct nmb_packet *nmb = &p->packet.nmb;
  struct nmb_name *question = &nmb->question.question_name;
  int name_type = question->name_type;
  BOOL dns_type = name_type == 0x20 || name_type == 0;
  BOOL bcast = nmb->header.nm_flags.bcast;
  int ttl=0;
  int rcode = 0;
  int nb_flags = 0;
  struct in_addr retip;
  char rdata[6];
  
  struct in_addr gp_ip = *interpret_addr2("255.255.255.255");
  BOOL success = True;
  
  struct name_record *n;
  enum name_search search = dns_type || name_type == 0x1b ?
    FIND_GLOBAL : FIND_SELF;
  
  DEBUG(3,("Name query "));
  
  if ((n = search_for_name(question,p->ip,p->timestamp, search)))
    {
      /* don't respond to broadcast queries unless the query is for
	 a name we own or it is for a Primary Domain Controller name */
      if (bcast && n->source != SELF && name_type != 0x1b)
	{
	  if (!lp_wins_proxy() || same_net(p->ip,n->ip,Netmask)) {
	    /* never reply with a negative response to broadcast queries */
	    return;
	  }
	}
      
      /* we will reply */
      ttl = n->death_time - p->timestamp;
      retip = n->ip;
      nb_flags = n->nb_flags;
    }
  else
    {
      if (bcast) return; /* never reply negative response to bcasts */
      success = False;
    }
  
  /* if asking for a group name (type 0x1e) return 255.255.255.255 */
  if (ip_equal(retip, gp_ip) && name_type == 0x1e) retip = gp_ip;

  /* if the IP is 0 then substitute my IP - we should see which one is on the 
     right interface for the caller to do this right XXX */
  if (zero_ip(retip)) retip = myip;

  if (success)
    {
      rcode = 0;
      DEBUG(3,("OK %s\n",inet_ntoa(retip)));      
    }
  else
    {
      rcode = 3;
      DEBUG(3,("UNKNOWN\n"));      
    }
  
  if (success)
    {
      rdata[0] = nb_flags;
      rdata[1] = 0;
      putip(&rdata[2],(char *)&retip);
    }
  
  reply_netbios_packet(p,nmb->header.name_trn_id,rcode,0,
		       &nmb->question.question_name,
		       nmb->question.question_type,
		       nmb->question.question_class,
		       ttl,
		       rdata, success ? 6 : 0);
}


/****************************************************************************
response from a name query
****************************************************************************/
static void response_netbios_packet(struct packet_struct *p)
{
  struct nmb_packet *nmb = &p->packet.nmb;
  struct nmb_name *question = &nmb->question.question_name;
  char *qname = question->name;
  BOOL bcast = nmb->header.nm_flags.bcast;
  struct name_response_record *n;

  if (nmb->answers == NULL)
    {
      DEBUG(3,("NMB packet response from %s (bcast=%s) - UNKNOWN\n",
	       inet_ntoa(p->ip),
	       BOOLSTR(bcast)));
      return;
    }
  
  if (nmb->answers->rr_type == NMB_STATUS) {
    DEBUG(3,("Name status "));
  }

  if (nmb->answers->rr_type == NMB_QUERY)	{
    DEBUG(3,("Name query "));
  }

  if (nmb->answers->rr_type == NMB_REG) {
    DEBUG(3,("Name registration "));
  }

  if (nmb->answers->rr_type == NMB_REL) {
    DEBUG(3,("Name release "));
  }

  DEBUG(3,("response for %s from %s (bcast=%s)\n",
	   namestr(&nmb->answers->rr_name),
	   inet_ntoa(p->ip),
	   BOOLSTR(bcast)));
  
  if (!(n = find_name_query(nmb->header.name_trn_id))) {
    DEBUG(3,("unknown response (received too late or from nmblookup?)\n"));
    return;
  }

  n->num_msgs++; /* count number of responses received */

  switch (n->cmd_type)
    {
    case MASTER_SERVER_CHECK     : DEBUG(4,("MASTER_SVR_CHECK\n")); break;
    case SERVER_CHECK            : DEBUG(4,("SERVER_CHECK\n")); break;
    case FIND_MASTER             : DEBUG(4,("FIND_MASTER\n")); break;
    case NAME_STATUS_MASTER_CHECK: DEBUG(4,("NAME_STAT_MST_CHK\n")); break;
    case NAME_STATUS_CHECK       : DEBUG(4,("NAME_STATUS_CHECK\n")); break;
    case CHECK_MASTER            : DEBUG(4,("CHECK_MASTER\n")); break;
    case NAME_CONFIRM_QUERY      : DEBUG(4,("NAME_CONFIRM_QUERY\n")); break;
    default: break;
    }
  switch (n->cmd_type)
    {
    case MASTER_SERVER_CHECK:
    case SERVER_CHECK:
    case FIND_MASTER:
      {
	if (nmb->answers->rr_type == NMB_QUERY)
	  {
	    enum cmd_type cmd = (n->cmd_type == MASTER_SERVER_CHECK) ?
	      NAME_STATUS_MASTER_CHECK :
	      NAME_STATUS_CHECK;
	    if (n->num_msgs > 1 && !strequal(qname,n->name.name))
	      {
		/* one subnet, one master browser per workgroup */
		/* XXXX force an election? */
		DEBUG(1,("more than one master browser replied!\n"));
	      }
	    
	    /* initiate a name status check on the server that replied */
	    queue_netbios_packet(ClientNMB,NMB_STATUS, cmd,
				 nmb->answers->rr_name.name,
				 nmb->answers->rr_name.name_type,0,
				 False,False,n->to_ip);
	  }
	else
	  {
	    DEBUG(1,("Name query reply has wrong answer rr_type\n"));
	  }
	break;
      }
      
    case NAME_STATUS_MASTER_CHECK:
    case NAME_STATUS_CHECK:
      {
	if (nmb->answers->rr_type == NMB_STATUS)
	  {
	    /* NMB_STATUS arrives: contains the workgroup name 
	       and server name we require */
	    struct nmb_name name;
	    fstring serv_name;
	    
	    if (interpret_node_status(nmb->answers->rdata,
				      &name,0x1d,serv_name,n->to_ip))
	      {
		if (*serv_name)
		  {
		    sync_server(n->cmd_type,serv_name,
				name.name,name.name_type,
				n->to_ip);
		  }
	      }
	    else
	      {
		DEBUG(1,("No 0x1d name type in interpret_node_status()\n"));
	      }
	  }
	else
	  {
	    DEBUG(1,("Name status reply has wrong answer rr_type\n"));
	  }
	break;
      }
      
    case CHECK_MASTER:
      {
	/* no action required here. it's when NO responses are received
	   that we need to do something (see expire_name_query_entries) */
	
	DEBUG(4, ("Master browser exists for %s at %s\n",
		  namestr(&n->name),
		  inet_ntoa(n->to_ip)));
	if (n->num_msgs > 1)
	  {
	    DEBUG(1,("more than one master browser!\n"));
	  }
	if (nmb->answers->rr_type != NMB_QUERY)
	  {
	    DEBUG(1,("Name query reply has wrong answer rr_type\n"));
	  }
	break;
      }
    case NAME_CONFIRM_QUERY:
      {
	DEBUG(4, ("Name query at WINS server: %s at %s - ",
		  namestr(&n->name),
		  inet_ntoa(n->to_ip)));
	if (nmb->header.rcode == 0 && nmb->answers->rdata)
	  {
	    int nb_flags = nmb->answers->rdata[0];
	    struct in_addr found_ip;
	    putip((char*)&found_ip,&nmb->answers->rdata[2]);
	    
	    DEBUG(4, (" OK: %s\n", inet_ntoa(found_ip)));
	    add_netbios_entry(nmb->answers->rr_name.name,
			      nmb->answers->rr_name.name_type,
			      nb_flags,GET_TTL(0),STATUS_QUERY,found_ip);
	  }
	else
	  {
	    DEBUG(4, (" NEGATIVE RESPONSE\n"));
	  }
	
	break;
      }
    default:
      {
	DEBUG(0,("unknown command received in response_netbios_packet\n"));
	break;
      }
    }
}


/****************************************************************************
  process a nmb packet
  ****************************************************************************/
void process_nmb(struct packet_struct *p)
{
	struct nmb_packet *nmb = &p->packet.nmb;

	debug_nmb_packet(p);

	switch (nmb->header.opcode) 
	{
		case 5:
		case 8:
		case 9:
		{
			if (nmb->header.qdcount==0 || nmb->header.arcount==0) break;
			if (nmb->header.response)
				response_name_reg(p);
			else
				reply_name_reg(p);
			break;
		}

		case 0:
		{
			if (nmb->header.response)
			{
				switch (nmb->question.question_type)
				{
					case 0x0:
					{
						response_netbios_packet(p);
						break;
					}
				}
				return;
			}
			else if (nmb->header.qdcount>0) 
			{
				switch (nmb->question.question_type)
				{
					case NMB_QUERY:
					{
						reply_name_query(p);
						break;
					}
					case NMB_STATUS:
					{
						reply_name_status(p);
						break;
					}
				}
				return;
			}
			break;
		}

		case 6:
		{
			if (nmb->header.qdcount==0 || nmb->header.arcount==0)
			{
				DEBUG(2,("netbios release packet rejected\n"));
				break;
			}

			if (nmb->header.response)
				response_name_release(p);
			else
				reply_name_release(p);
			break;
		}
	}

}