source/namework.c

   1 /*
   2    Unix SMB/Netbios implementation.
   3    Version 1.9.
   4    NBT netbios routines and daemon - version 2
   5    Copyright (C) Andrew Tridgell 1994-1997
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 2 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program; if not, write to the Free Software
  19    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20
  21    Revision History:
  22
  23    14 jan 96: lkcl@pires.co.uk
  24    added multiple workgroup domain master support
  25
  26 */
  27
  28 #include "includes.h"
  29
  30 extern int ClientNMB;
  31 extern int ClientDGRAM;
  32
  33 #define TEST_CODE /* want to debug unknown browse packets */
  34
  35 extern int DEBUGLEVEL;
  36 extern pstring scope;
  37 extern BOOL CanRecurse;
  38
  39 extern pstring myname;
  40 extern fstring myworkgroup;
  41
  42 extern int ClientNMB;
  43 extern int ClientDGRAM;
  44
  45 extern struct in_addr ipzero;
  46
  47 extern int workgroup_count; /* total number of workgroups we know about */
  48
  49 /* this is our domain/workgroup/server database */
  50 extern struct subnet_record *subnetlist;
  51
  52 extern int  updatecount;
  53
  54 /* backup request types: which servers are to be included */
  55 #define MASTER_TYPE (SV_TYPE_MASTER_BROWSER)
  56 #define DOMCTL_TYPE (SV_TYPE_DOMAIN_CTRL   )
  57
  58 extern time_t StartupTime;
  59
  60 extern BOOL updatedlists;
  61
  62 /****************************************************************************
  63 tell a server to become a backup browser
  64 state - 0x01 become backup instead of master
  65       - 0x02 remove all entries in browse list and become non-master
  66       - 0x04 stop master browser service altogether. NT ignores this
  67 **************************************************************************/
  68 void reset_server(char *name, int state, struct in_addr ip)
  69 {
  70   char outbuf[20];
  71   char *p;
  72
  73   bzero(outbuf,sizeof(outbuf));
  74   p = outbuf;
  75
  76   CVAL(p,0) = ANN_ResetBrowserState;
  77   CVAL(p,2) = state;
  78   p += 2;
  79
  80   DEBUG(2,("sending reset to %s %s of state %d\n",
  81            name,inet_ntoa(ip),state));
  82
  83   send_mailslot_reply(False,BROWSE_MAILSLOT,ClientDGRAM,
  84               outbuf,PTR_DIFF(p,outbuf),
  85                       myname,name,0x20,0x1d,ip,*iface_ip(ip));
  86 }
  87
  88
  89 /****************************************************************************
  90 tell a server to become a backup browser
  91 **************************************************************************/
  92 void tell_become_backup(void)
  93 {
  94   /* XXXX note: this function is currently unsuitable for use, as it
  95      does not properly check that a server is in a fit state to become
  96      a backup browser before asking it to be one.
  97    */
  98
  99   struct subnet_record *d;
 100   for (d = FIRST_SUBNET; d; d = NEXT_SUBNET_EXCLUDING_WINS(d))
 101     {
 102       struct work_record *work;
 103       for (work = d->workgrouplist; work; work = work->next)
 104         {
 105           struct server_record *s;
 106           int num_servers = 0;
 107           int num_backups = 0;
 108
 109           for (s = work->serverlist; s; s = s->next)
 110             {
 111               if (s->serv.type & SV_TYPE_DOMAIN_ENUM) continue;
 112
 113               num_servers++;
 114
 115               if (is_myname(s->serv.name)) continue;
 116
 117               if (s->serv.type & SV_TYPE_BACKUP_BROWSER) {
 118                 num_backups++;
 119                 continue;
 120               }
 121
 122               if (s->serv.type & SV_TYPE_MASTER_BROWSER) continue;
 123
 124               if (!(s->serv.type & SV_TYPE_POTENTIAL_BROWSER)) continue;
 125
 126               DEBUG(3,("num servers: %d num backups: %d\n",
 127                        num_servers, num_backups));
 128
 129               /* make first server a backup server. thereafter make every
 130                  tenth server a backup server */
 131               if (num_backups != 0 && (num_servers+9) / num_backups > 10)
 132                 {
 133                   continue;
 134                 }
 135
 136               DEBUG(2,("sending become backup to %s %s for %s\n",
 137                        s->serv.name, inet_ntoa(d->bcast_ip),
 138                        work->work_group));
 139
 140               /* type 11 request from MYNAME(20) to WG(1e) for SERVER */
 141               do_announce_request(s->serv.name, work->work_group,
 142                                   ANN_BecomeBackup, 0x20, 0x1e, d->bcast_ip);
 143             }
 144         }
 145     }
 146 }
 147
 148
 149 /*******************************************************************
 150   same context: scope. should check name_type as well, and makes sure
 151   we don't process messages from ourselves
 152   ******************************************************************/
 153 BOOL same_context(struct dgram_packet *dgram)
 154 {
 155   if (!strequal(dgram->dest_name  .scope,scope )) return(True);
 156   if ( is_myname(dgram->source_name.name)) return(True);
 157
 158   return(False);
 159 }
 160
 161
 162 /*******************************************************************
 163   process a domain announcement frame
 164
 165   Announce frames come in 3 types. Servers send host announcements
 166   (command=1) to let the master browswer know they are
 167   available. Master browsers send local master announcements
 168   (command=15) to let other masters and backups that they are the
 169   master. They also send domain announcements (command=12) to register
 170   the domain
 171
 172   The comment field of domain announcements contains the master
 173   browser name. The servertype is used by NetServerEnum to select
 174   resources. We just have to pass it to smbd (via browser.dat) and let
 175   the client choose using bit masks.
 176   ******************************************************************/
 177 static void process_localnet_announce(struct packet_struct *p,uint16 command,char *buf)
 178 {
 179   struct dgram_packet *dgram = &p->packet.dgram;
 180   struct subnet_record *d = find_subnet(p->ip);  /* Explicitly exclude WINS - local nets only */
 181   int update_count = CVAL(buf,0);
 182
 183   int ttl = IVAL(buf,1)/1000;
 184   char *name = buf+5;
 185   int osmajor=CVAL(buf,21);
 186   int osminor=CVAL(buf,22);
 187   uint32 servertype = IVAL(buf,23);
 188   uint32 browse_type= CVAL(buf,27);
 189   uint32 browse_sig = CVAL(buf,29);
 190   char *comment = buf+31;
 191
 192   struct work_record *work;
 193   char *work_name;
 194   char *serv_name = dgram->source_name.name;
 195   BOOL add = False;
 196
 197   comment[43] = 0;
 198
 199   DEBUG(4,("Announce(%d) %s(%x)",command,name,name[15]));
 200   DEBUG(4,("%s count=%d ttl=%d OS=(%d,%d) type=%08x sig=%4x %4x comment=%s\n",
 201            namestr(&dgram->dest_name),update_count,ttl,osmajor,osminor,
 202            servertype,browse_type,browse_sig,comment));
 203
 204   name[15] = 0;
 205
 206   if (dgram->dest_name.name_type == 0 && command == ANN_HostAnnouncement)
 207     {
 208       DEBUG(2,("Announce to nametype(0) not supported yet\n"));
 209       return;
 210     }
 211
 212   if (command == ANN_DomainAnnouncement &&
 213       ((!strequal(dgram->dest_name.name, MSBROWSE)) ||
 214        dgram->dest_name.name_type != 0x1))
 215     {
 216       DEBUG(0,("Announce(%d) from %s should be __MSBROWSE__(1) not %s\n",
 217                 command, inet_ntoa(p->ip), namestr(&dgram->dest_name)));
 218       return;
 219     }
 220
 221   if (!strequal(dgram->dest_name.scope,scope )) return;
 222
 223   if (command == ANN_DomainAnnouncement) {
 224     /* XXXX if we are a master browser for the workgroup work_name,
 225        then there is a local subnet configuration problem. only
 226        we should be sending out such domain announcements, because
 227        as the master browser, that is our job.
 228
 229        stop being a master browser, and force an election. this will
 230        sort out the network problem. hopefully.
 231      */
 232
 233     work_name = name;
 234     add = True;
 235   } else {
 236     work_name = dgram->dest_name.name;
 237   }
 238
 239   /* we need some way of finding out about new workgroups
 240      that appear to be sending packets to us. The name_type checks make
 241      sure we don't add host names as workgroups */
 242   if (command == ANN_HostAnnouncement &&
 243       (dgram->dest_name.name_type == 0x1d ||
 244        dgram->dest_name.name_type == 0x1e))
 245     add = True;
 246
 247   DEBUG(4,("search for workgroup: %s (add? %s)\n",
 248             work_name, BOOLSTR(add)));
 249
 250   if (!(work = find_workgroupstruct(d, work_name,add)))
 251     return;
 252
 253   DEBUG(4, ("workgroup %s on %s\n", work->work_group, serv_name));
 254
 255   ttl = GET_TTL(ttl);
 256
 257   /* add them to our browse list, and update the browse.dat file */
 258   add_server_entry(d,work,name,servertype|SV_TYPE_LOCAL_LIST_ONLY,ttl,comment,True);
 259   updatedlists = True;
 260
 261 #if 0
 262   /* the tell become backup code is broken, no great harm is done by
 263      disabling it */
 264   tell_become_backup();
 265 #endif
 266 }
 267
 268 /*******************************************************************
 269   process a master announcement frame
 270   Domain master browsers recieve these from local masters. The Domain
 271   master should then issue a sync with the local master, asking for
 272   that machines local server list.
 273   ******************************************************************/
 274 static void process_master_announce(struct packet_struct *p,char *buf)
 275 {
 276   struct dgram_packet *dgram = &p->packet.dgram;
 277   char *name = buf;
 278   struct work_record *work;
 279   name[15] = 0;
 280
 281   DEBUG(3,("process_master_announce: Master Announce from %s (%s)\n",name,inet_ntoa(p->ip)));
 282
 283   if (same_context(dgram)) return;
 284
 285   if (!wins_subnet)
 286     {
 287       DEBUG(3,("process_master_announce: No wins subnet !\n"));
 288       return;
 289     }
 290
 291   if (!lp_domain_master())
 292     {
 293       DEBUG(3,("process_master_announce: Not configured as domain master - ignoring master announce.\n"));
 294       return;
 295     }
 296
 297   for (work = wins_subnet->workgrouplist; work; work = work->next)
 298   {
 299     if (AM_MASTER(work) || AM_DOMMST(work))
 300     {
 301           /* merge browse lists with them */
 302           add_browser_entry(name,0x1d, work->work_group,30,wins_subnet,p->ip,True);
 303     }
 304   }
 305 }
 306
 307 /*******************************************************************
 308   process a receive backup list request
 309
 310   we receive a list of servers, and we attempt to locate them all on
 311   our local subnet, and sync browse lists with them on the workgroup
 312   they are said to be in.
 313
 314   XXXX NOTE: this function is in overdrive. it should not really do
 315   half of what it actually does (it should pick _one_ name from the
 316   list received and sync with it at regular intervals, rather than
 317   sync with them all only once!)
 318
 319   ******************************************************************/
 320 static void process_rcv_backup_list(struct packet_struct *p,char *buf)
 321 {
 322   struct dgram_packet *dgram = &p->packet.dgram;
 323   int count = CVAL(buf,0);
 324   uint32 info = IVAL(buf,1); /* XXXX caller's incremental info */
 325   char *buf1;
 326
 327   DEBUG(3,("Receive Backup ack for %s from %s total=%d info=%d\n",
 328            namestr(&dgram->dest_name), inet_ntoa(p->ip),
 329            count, info));
 330
 331   if (same_context(dgram)) return;
 332
 333   if (count <= 0) return;
 334
 335   /* go through the list of servers attempting to sync browse lists */
 336   for (buf1 = buf+5; *buf1 && count; buf1 = skip_string(buf1, 1), --count)
 337   {
 338     struct in_addr back_ip;
 339     /* struct subnet_record *d; */
 340
 341     DEBUG(4,("Searching for backup browser %s at %s...\n",
 342                buf1, inet_ntoa(p->ip)));
 343
 344     /* XXXX assume name is a DNS name NOT a netbios name. a more complete
 345            approach is to use reply_name_query functionality to find the name */
 346
 347     back_ip = *interpret_addr2(buf1);
 348
 349     if (zero_ip(back_ip))
 350         {
 351           DEBUG(4,("Failed to find backup browser server using DNS\n"));
 352           continue;
 353         }
 354
 355       DEBUG(4,("Found browser server at %s\n", inet_ntoa(back_ip)));
 356       DEBUG(4,("END THIS LOOP: CODE NEEDS UPDATING\n"));
 357
 358 #if 0
 359       /* XXXX function needs work */
 360       continue;
 361
 362     if ((d = find_subnet(back_ip)))
 363         {
 364           struct subnet_record *d1;
 365           for (d1 = subnetlist; d1; d1 = d1->next)
 366           {
 367               struct work_record *work;
 368               for (work = d1->workgrouplist; work; work = work->next)
 369                 {
 370                   if (work->token == 0 /* token */)
 371                   {
 372                       queue_netbios_packet(d1,ClientNMB,NMB_QUERY,NAME_QUERY_SRV_CHK,
 373                                            work->work_group,0x1d,
 374                        0,0,0,NULL,NULL,
 375                                            False,False,back_ip,back_ip);
 376                       return;
 377                   }
 378                 }
 379           }
 380         }
 381 #endif
 382   }
 383 }
 384
 385
 386 /****************************************************************************
 387   send a backup list response.
 388   **************************************************************************/
 389 static void send_backup_list(char *work_name, struct nmb_name *src_name,
 390                              int token, uint32 info,
 391                              int name_type, struct in_addr ip)
 392 {
 393   char outbuf[1024];
 394   char *p, *countptr, *nameptr;
 395   int count = 0;
 396   char *theirname = src_name->name;
 397
 398   DEBUG(3,("sending backup list of %s to %s: %s(%x) %s(%x)\n",
 399            work_name, inet_ntoa(ip),
 400            myname,0x0,theirname,0x0));
 401
 402   if (name_type == 0x1d)
 403     {
 404       DEBUG(4,("master browsers: "));
 405     }
 406   else if (name_type == 0x1b)
 407     {
 408       DEBUG(4,("domain controllers: "));
 409     }
 410   else
 411     {
 412       DEBUG(0,("backup request for unknown type %0x\n", name_type));
 413       return;
 414     }
 415
 416   bzero(outbuf,sizeof(outbuf));
 417   p = outbuf;
 418
 419   CVAL(p,0) = ANN_GetBackupListResp;    /* backup list response */
 420
 421   p++;
 422   countptr = p;
 423
 424   SIVAL(p,1,info); /* the sender's unique info */
 425
 426   p += 5;
 427
 428   nameptr = p;
 429
 430 #if 0
 431
 432   for (d = FIRST_SUBNET; d; d = NEXT_SUBNET_INCLUDING_WINS(d))
 433   {
 434       struct work_record *work;
 435
 436       for (work = d->workgrouplist; work; work = work->next)
 437         {
 438           struct server_record *s;
 439
 440           if (!strequal(work->work_group, work_name)) continue;
 441
 442           for (s = work->serverlist; s; s = s->next)
 443             {
 444               BOOL found = False;
 445               char *n;
 446
 447               if (s->serv.type & SV_TYPE_DOMAIN_ENUM) continue;
 448
 449               for (n = nameptr; n < p; n = skip_string(n, 1))
 450                 {
 451                   if (strequal(n, s->serv.name)) found = True;
 452                 }
 453
 454               if (found) continue; /* exclude names already added */
 455
 456               /* workgroup request: include all backup browsers in the list */
 457               /* domain request: include all domain members in the list */
 458
 459               if ((name_type == 0x1d && (s->serv.type & MASTER_TYPE)) ||
 460                       (name_type == 0x1b && (s->serv.type & DOMCTL_TYPE)))
 461                 {
 462                   DEBUG(4, ("%s ", s->serv.name));
 463
 464                   count++;
 465                   strcpy(p,s->serv.name);
 466                   strupper(p);
 467                   p = skip_string(p,1);
 468                 }
 469          }
 470         }
 471   }
 472
 473 #endif
 474
 475         count++;
 476         strcpy(p,myname);
 477         strupper(p);
 478         p = skip_string(p,1);
 479
 480   if (count == 0)
 481     {
 482       DEBUG(4, ("none\n"));
 483     }
 484   else
 485     {
 486       DEBUG(4, (" - count %d\n", count));
 487     }
 488
 489   CVAL(countptr, 0) = count;
 490
 491   {
 492     int len = PTR_DIFF(p, outbuf);
 493     debug_browse_data(outbuf, len);
 494   }
 495   send_mailslot_reply(False,BROWSE_MAILSLOT,ClientDGRAM,
 496               outbuf,PTR_DIFF(p,outbuf),
 497                       myname,theirname,0x0,0x0,ip,*iface_ip(ip));
 498 }
 499
 500
 501 /*******************************************************************
 502   process a send backup list request
 503
 504   A client sends a backup list request to ask for a list of servers on
 505   the net that maintain server lists for a domain. A server is then
 506   chosen from this list to send NetServerEnum commands to to list
 507   available servers.
 508
 509   Currently samba only sends back one name in the backup list, its
 510   own. For larger nets we'll have to add backups and send "become
 511   backup" requests occasionally.
 512   ******************************************************************/
 513 static void process_send_backup_list(struct packet_struct *p,char *buf)
 514 {
 515   struct dgram_packet *dgram = &p->packet.dgram;
 516   struct in_addr ip = dgram->header.source_ip;
 517   struct subnet_record *d;
 518   struct work_record *work;
 519
 520   int    token = CVAL(buf,0); /* sender's key index for the workgroup */
 521   uint32 info  = IVAL(buf,1); /* XXXX don't know: some sort of info */
 522   int name_type = dgram->dest_name.name_type;
 523
 524   if (same_context(dgram)) return;
 525
 526   if (name_type != 0x1b && name_type != 0x1d) {
 527     DEBUG(0,("backup request to wrong type %d from %s\n",
 528               name_type,inet_ntoa(ip)));
 529     return;
 530   }
 531
 532   for (d = subnetlist; d; d = d->next)
 533     {
 534       for (work = d->workgrouplist; work; work = work->next)
 535         {
 536           if (strequal(work->work_group, dgram->dest_name.name))
 537             {
 538               DEBUG(2,("sending backup list to %s %s id=%x\n",
 539                        namestr(&dgram->dest_name),inet_ntoa(ip),info));
 540
 541               send_backup_list(work->work_group,&dgram->source_name,
 542                                token,info,name_type,ip);
 543               return;
 544             }
 545         }
 546     }
 547 }
 548
 549
 550 /*******************************************************************
 551   process a reset browser state
 552
 553   diagnostic packet:
 554   0x1 - stop being a master browser and become a backup browser.
 555   0x2 - discard browse lists, stop being a master browser, try again.
 556   0x4 - stop being a master browser forever. no way. ain't gonna.
 557
 558   ******************************************************************/
 559 static void process_reset_browser(struct packet_struct *p,char *buf)
 560 {
 561   struct dgram_packet *dgram = &p->packet.dgram;
 562   int state = CVAL(buf,0);
 563
 564   DEBUG(1,("received diagnostic browser reset request to %s state=0x%X\n",
 565            namestr(&dgram->dest_name), state));
 566
 567   /* stop being a master but still deal with being a backup browser */
 568   if (state & 0x1)
 569     {
 570       struct subnet_record *d;
 571       for (d = FIRST_SUBNET; d; d = NEXT_SUBNET_EXCLUDING_WINS(d))
 572         {
 573           struct work_record *work;
 574           for (work = d->workgrouplist; work; work = work->next)
 575             {
 576               if (AM_MASTER(work))
 577                 {
 578                   unbecome_local_master(d,work,SV_TYPE_MASTER_BROWSER);
 579                 }
 580             }
 581         }
 582     }
 583
 584   /* XXXX documentation inconsistency: the above description does not
 585      exactly tally with what is implemented for state & 0x2
 586    */
 587
 588   /* totally delete all servers and start afresh */
 589   if (state & 0x2)
 590     {
 591       struct subnet_record *d;
 592       for (d = FIRST_SUBNET; d; d = NEXT_SUBNET_INCLUDING_WINS(d))
 593         {
 594           struct work_record *work;
 595           for (work=d->workgrouplist;work;work=remove_workgroup(d,work,True));
 596         }
 597       add_my_subnets(myworkgroup);
 598     }
 599
 600   /* stop browsing altogether. i don't think this is a good idea! */
 601   if (state & 0x4)
 602     {
 603       DEBUG(1,("ignoring request to stop being a browser. sorry!\n"));
 604     }
 605 }
 606
 607 /*******************************************************************
 608   process a announcement request
 609
 610   clients send these when they want everyone to send an announcement
 611   immediately. This can cause quite a storm of packets!
 612   ******************************************************************/
 613 static void process_announce_request(struct packet_struct *p,char *buf)
 614 {
 615   struct dgram_packet *dgram = &p->packet.dgram;
 616   struct work_record *work;
 617   struct in_addr ip = dgram->header.source_ip;
 618   struct subnet_record *d = find_subnet(ip); /* Explicitly NO WINS */
 619   int token = CVAL(buf,0);
 620   char *name = buf+1;
 621
 622   name[15] = 0;
 623
 624   DEBUG(3,("process_announce_request: Announce request from %s to %s token=0x%X\n",
 625            name,namestr(&dgram->dest_name), token));
 626
 627   if (is_myname(dgram->source_name.name)) return;
 628
 629   /* XXXX BUG or FEATURE?: need to ensure that we are a member of
 630      this workgroup before announcing, particularly as we only
 631      respond on local interfaces anyway.
 632
 633      if (strequal(dgram->dest_name, myworkgroup) return; ???
 634    */
 635
 636   if (!d)
 637     {
 638       DEBUG(3,("process_announce_request: No local interface to announce to %s\n",
 639                 name));
 640       return;
 641     }
 642
 643   for (work = d->workgrouplist; work; work = work->next)
 644     {
 645      /* XXXX BUG: the destination name type should also be checked,
 646         not just the name. e.g if the name is WORKGROUP(0x1d) then
 647         we should only respond if we own that name */
 648
 649       if (strequal(dgram->dest_name.name,work->work_group))
 650         {
 651           work->needannounce = True;
 652         }
 653     }
 654 }
 655
 656
 657
 658 /****************************************************************************
 659 process a browse frame
 660 ****************************************************************************/
 661 void process_browse_packet(struct packet_struct *p,char *buf,int len)
 662 {
 663   int command = CVAL(buf,0);
 664   switch (command)
 665     {
 666     case ANN_HostAnnouncement:
 667     case ANN_DomainAnnouncement:
 668     case ANN_LocalMasterAnnouncement:
 669       {
 670         debug_browse_data(buf, len);
 671         process_localnet_announce(p,command,buf+1);
 672         break;
 673       }
 674
 675     case ANN_AnnouncementRequest:
 676       {
 677         process_announce_request(p,buf+1);
 678         break;
 679       }
 680
 681     case ANN_Election:
 682       {
 683         process_election(p,buf+1);
 684         break;
 685       }
 686
 687     case ANN_GetBackupListReq:
 688       {
 689         debug_browse_data(buf, len);
 690         process_send_backup_list(p,buf+1);
 691         break;
 692       }
 693
 694     case ANN_GetBackupListResp:
 695     {
 696         debug_browse_data(buf, len);
 697         process_rcv_backup_list(p, buf+1);
 698         break;
 699     }
 700
 701     case ANN_ResetBrowserState:
 702       {
 703         process_reset_browser(p, buf+1);
 704         break;
 705       }
 706
 707     case ANN_MasterAnnouncement:
 708       {
 709         process_master_announce(p,buf+1);
 710         break;
 711       }
 712
 713     default:
 714       {
 715         struct dgram_packet *dgram = &p->packet.dgram;
 716         DEBUG(4,("ignoring browse packet %d from %s %s to %s\n",
 717                  command, namestr(&dgram->source_name),
 718                  inet_ntoa(p->ip), namestr(&dgram->dest_name)));
 719       }
 720     }
 721 }
 722
 723