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 1994-1996
   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
  41 extern int ClientNMB;
  42 extern int ClientDGRAM;
  43
  44 extern struct in_addr ipzero;
  45
  46 extern int workgroup_count; /* total number of workgroups we know about */
  47
  48 /* this is our domain/workgroup/server database */
  49 extern struct subnet_record *subnetlist;
  50
  51 extern int  updatecount;
  52
  53 /* backup request types: which servers are to be included */
  54 #define MASTER_TYPE (SV_TYPE_MASTER_BROWSER)
  55 #define DOMCTL_TYPE (SV_TYPE_DOMAIN_CTRL   )
  56
  57 extern time_t StartupTime;
  58
  59 extern BOOL updatedlists;
  60
  61 /****************************************************************************
  62 tell a server to become a backup browser
  63 state - 0x01 become backup instead of master
  64       - 0x02 remove all entries in browse list and become non-master
  65       - 0x04 stop master browser service altogether. NT ignores this
  66 **************************************************************************/
  67 void reset_server(char *name, int state, struct in_addr ip)
  68 {
  69   char outbuf[20];
  70   char *p;
  71
  72   bzero(outbuf,sizeof(outbuf));
  73   p = outbuf;
  74
  75   CVAL(p,0) = ANN_ResetBrowserState;
  76   CVAL(p,2) = state;
  77   p += 2;
  78
  79   DEBUG(2,("sending reset to %s %s of state %d\n",
  80            name,inet_ntoa(ip),state));
  81
  82   send_mailslot_reply(BROWSE_MAILSLOT,ClientDGRAM,outbuf,PTR_DIFF(p,outbuf),
  83                       myname,name,0x20,0x1d,ip,*iface_ip(ip));
  84 }
  85
  86
  87 /****************************************************************************
  88 tell a server to become a backup browser
  89 **************************************************************************/
  90 void tell_become_backup(void)
  91 {
  92   /* XXXX note: this function is currently unsuitable for use, as it
  93      does not properly check that a server is in a fit state to become
  94      a backup browser before asking it to be one.
  95    */
  96
  97   struct subnet_record *d;
  98   for (d = subnetlist; d; d = d->next)
  99     {
 100       struct work_record *work;
 101       for (work = d->workgrouplist; work; work = work->next)
 102         {
 103           struct server_record *s;
 104           int num_servers = 0;
 105           int num_backups = 0;
 106
 107           for (s = work->serverlist; s; s = s->next)
 108             {
 109               if (s->serv.type & SV_TYPE_DOMAIN_ENUM) continue;
 110
 111               num_servers++;
 112
 113               if (strequal(myname, s->serv.name)) continue;
 114
 115               if (s->serv.type & SV_TYPE_BACKUP_BROWSER) {
 116                 num_backups++;
 117                 continue;
 118               }
 119
 120               if (s->serv.type & SV_TYPE_MASTER_BROWSER) continue;
 121
 122               if (!(s->serv.type & SV_TYPE_POTENTIAL_BROWSER)) continue;
 123
 124               DEBUG(3,("num servers: %d num backups: %d\n",
 125                        num_servers, num_backups));
 126
 127               /* make first server a backup server. thereafter make every
 128                  tenth server a backup server */
 129               if (num_backups != 0 && (num_servers+9) / num_backups > 10)
 130                 {
 131                   continue;
 132                 }
 133
 134               DEBUG(2,("sending become backup to %s %s for %s\n",
 135                        s->serv.name, inet_ntoa(d->bcast_ip),
 136                        work->work_group));
 137
 138               /* type 11 request from MYNAME(20) to WG(1e) for SERVER */
 139               do_announce_request(s->serv.name, work->work_group,
 140                                   ANN_BecomeBackup, 0x20, 0x1e, d->bcast_ip);
 141             }
 142         }
 143     }
 144 }
 145
 146
 147 /*******************************************************************
 148   same context: scope. should check name_type as well, and makes sure
 149   we don't process messages from ourselves
 150   ******************************************************************/
 151 BOOL same_context(struct dgram_packet *dgram)
 152 {
 153   if (!strequal(dgram->dest_name  .scope,scope )) return(True);
 154   if ( strequal(dgram->source_name.name ,myname)) return(True);
 155
 156   return(False);
 157 }
 158
 159
 160 /*******************************************************************
 161   process a domain announcement frame
 162
 163   Announce frames come in 3 types. Servers send host announcements
 164   (command=1) to let the master browswer know they are
 165   available. Master browsers send local master announcements
 166   (command=15) to let other masters and backups that they are the
 167   master. They also send domain announcements (command=12) to register
 168   the domain
 169
 170   The comment field of domain announcements contains the master
 171   browser name. The servertype is used by NetServerEnum to select
 172   resources. We just have to pass it to smbd (via browser.dat) and let
 173   the client choose using bit masks.
 174   ******************************************************************/
 175 static void process_announce(struct packet_struct *p,uint16 command,char *buf)
 176 {
 177   struct dgram_packet *dgram = &p->packet.dgram;
 178   struct in_addr ip = dgram->header.source_ip;
 179   struct subnet_record *d = find_subnet(ip);
 180   int update_count = CVAL(buf,0);
 181
 182   int ttl = IVAL(buf,1)/1000;
 183   char *name = buf+5;
 184   int osmajor=CVAL(buf,21);
 185   int osminor=CVAL(buf,22);
 186   uint32 servertype = IVAL(buf,23);
 187   uint32 browse_type= CVAL(buf,27);
 188   uint32 browse_sig = CVAL(buf,29);
 189   char *comment = buf+31;
 190
 191   struct work_record *work;
 192   char *work_name;
 193   char *serv_name = dgram->source_name.name;
 194   BOOL add = False;
 195
 196   comment[43] = 0;
 197
 198   DEBUG(4,("Announce(%d) %s(%x)",command,name,name[15]));
 199   DEBUG(4,("%s count=%d ttl=%d OS=(%d,%d) type=%08x sig=%4x %4x comment=%s\n",
 200            namestr(&dgram->dest_name),update_count,ttl,osmajor,osminor,
 201            servertype,browse_type,browse_sig,comment));
 202
 203   name[15] = 0;
 204
 205   if (dgram->dest_name.name_type == 0 && command == ANN_HostAnnouncement)
 206     {
 207       DEBUG(2,("Announce to nametype(0) not supported yet\n"));
 208       return;
 209     }
 210
 211   if (command == ANN_DomainAnnouncement &&
 212       ((!strequal(dgram->dest_name.name, MSBROWSE)) ||
 213        dgram->dest_name.name_type != 0x1))
 214     {
 215       DEBUG(0,("Announce(%d) from %s should be __MSBROWSE__(1) not %s\n",
 216                 command, inet_ntoa(ip), namestr(&dgram->dest_name)));
 217       return;
 218     }
 219
 220   if (!strequal(dgram->dest_name.scope,scope )) return;
 221
 222   if (command == ANN_DomainAnnouncement) {
 223     /* XXXX if we are a master browser for the workgroup work_name,
 224        then there is a local subnet configuration problem. only
 225        we should be sending out such domain announcements, because
 226        as the master browser, that is our job.
 227
 228        stop being a master browser, and force an election. this will
 229        sort out the network problem. hopefully.
 230      */
 231
 232     work_name = name;
 233     add = True;
 234   } else {
 235     work_name = dgram->dest_name.name;
 236   }
 237
 238   /* we need some way of finding out about new workgroups
 239      that appear to be sending packets to us. The name_type checks make
 240      sure we don't add host names as workgroups */
 241   if (command == ANN_HostAnnouncement &&
 242       (dgram->dest_name.name_type == 0x1d ||
 243        dgram->dest_name.name_type == 0x1e))
 244     add = True;
 245
 246   if (!(work = find_workgroupstruct(d, work_name,add)))
 247     return;
 248
 249   DEBUG(4, ("workgroup %s on %s\n", work->work_group, serv_name));
 250
 251   ttl = GET_TTL(ttl);
 252
 253   /* add them to our browse list, and update the browse.dat file */
 254   add_server_entry(d,work,name,servertype,ttl,comment,True);
 255   updatedlists = True;
 256
 257 #if 0
 258   /* the tell become backup code is broken, no great harm is done by
 259      disabling it */
 260   tell_become_backup();
 261 #endif
 262
 263   /* get the local_only browse list from the local master and add it
 264      to ours. */
 265   if (command == ANN_LocalMasterAnnouncement)
 266   {
 267     add_browser_entry(serv_name,dgram->dest_name.name_type,
 268                       work->work_group,30,ip,True);
 269   }
 270 }
 271
 272 /*******************************************************************
 273   process a master announcement frame
 274   ******************************************************************/
 275 static void process_master_announce(struct packet_struct *p,char *buf)
 276 {
 277   struct dgram_packet *dgram = &p->packet.dgram;
 278   struct in_addr ip = dgram->header.source_ip;
 279   struct subnet_record *d = find_subnet(ip);
 280   struct subnet_record *mydomain = find_subnet(*iface_bcast(ip));
 281   char *name = buf;
 282   struct work_record *work;
 283   name[15] = 0;
 284
 285   DEBUG(3,("Master Announce from %s (%s)\n",name,inet_ntoa(ip)));
 286
 287   if (same_context(dgram)) return;
 288
 289   if (!d || !mydomain) return;
 290
 291   if (!lp_domain_master()) return;
 292
 293   for (work = mydomain->workgrouplist; work; work = work->next)
 294   {
 295     if (AM_MASTER(work))
 296     {
 297           /* merge browse lists with them */
 298           add_browser_entry(name,0x1b, work->work_group,30,ip,True);
 299     }
 300   }
 301 }
 302
 303 /*******************************************************************
 304   process a receive backup list request
 305
 306   we receive a list of servers, and we attempt to locate them all on
 307   our local subnet, and sync browse lists with them on the workgroup
 308   they are said to be in.
 309
 310   XXXX NOTE: this function is in overdrive. it should not really do
 311   half of what it actually does (it should pick _one_ name from the
 312   list received and sync with it at regular intervals, rather than
 313   sync with them all only once!)
 314
 315   ******************************************************************/
 316 static void process_rcv_backup_list(struct packet_struct *p,char *buf)
 317 {
 318   struct dgram_packet *dgram = &p->packet.dgram;
 319   struct in_addr ip = dgram->header.source_ip;
 320   int count = CVAL(buf,0);
 321   uint32 info = IVAL(buf,1); /* XXXX caller's incremental info */
 322   char *buf1;
 323
 324   DEBUG(3,("Receive Backup ack for %s from %s total=%d info=%d\n",
 325            namestr(&dgram->dest_name), inet_ntoa(ip),
 326            count, info));
 327
 328   if (same_context(dgram)) return;
 329
 330   if (count <= 0) return;
 331
 332   /* go through the list of servers attempting to sync browse lists */
 333   for (buf1 = buf+5; *buf1 && count; buf1 = skip_string(buf1, 1), --count)
 334   {
 335     struct in_addr back_ip;
 336     /* struct subnet_record *d; */
 337
 338     DEBUG(4,("Searching for backup browser %s at %s...\n",
 339                buf1, inet_ntoa(ip)));
 340
 341     /* XXXX assume name is a DNS name NOT a netbios name. a more complete
 342            approach is to use reply_name_query functionality to find the name */
 343
 344     back_ip = *interpret_addr2(buf1);
 345
 346     if (zero_ip(back_ip))
 347         {
 348           DEBUG(4,("Failed to find backup browser server using DNS\n"));
 349           continue;
 350         }
 351
 352       DEBUG(4,("Found browser server at %s\n", inet_ntoa(back_ip)));
 353       DEBUG(4,("END THIS LOOP: CODE NEEDS UPDATING\n"));
 354
 355 #if 0
 356       /* XXXX function needs work */
 357       continue;
 358
 359     if ((d = find_subnet(back_ip)))
 360         {
 361           struct subnet_record *d1;
 362           for (d1 = subnetlist; d1; d1 = d1->next)
 363           {
 364               struct work_record *work;
 365               for (work = d1->workgrouplist; work; work = work->next)
 366                 {
 367                   if (work->token == 0 /* token */)
 368                   {
 369                       queue_netbios_packet(d1,ClientNMB,NMB_QUERY,NAME_QUERY_SRV_CHK,
 370                                            work->work_group,0x1d,
 371                        0,0,0,NULL,NULL,
 372                                            False,False,back_ip,back_ip);
 373                       return;
 374                   }
 375                 }
 376           }
 377         }
 378 #endif
 379   }
 380 }
 381
 382
 383 /****************************************************************************
 384   send a backup list response.
 385   **************************************************************************/
 386 static void send_backup_list(char *work_name, struct nmb_name *src_name,
 387                              int token, uint32 info,
 388                              int name_type, struct in_addr ip)
 389 {
 390   char outbuf[1024];
 391   char *p, *countptr, *nameptr;
 392   int count = 0;
 393   char *theirname = src_name->name;
 394
 395   DEBUG(3,("sending backup list of %s to %s: %s(%x) %s(%x)\n",
 396            work_name, inet_ntoa(ip),
 397            myname,0x0,theirname,0x0));
 398
 399   if (name_type == 0x1d)
 400     {
 401       DEBUG(4,("master browsers: "));
 402     }
 403   else if (name_type == 0x1b)
 404     {
 405       DEBUG(4,("domain controllers: "));
 406     }
 407   else
 408     {
 409       DEBUG(0,("backup request for unknown type %0x\n", name_type));
 410       return;
 411     }
 412
 413   bzero(outbuf,sizeof(outbuf));
 414   p = outbuf;
 415
 416   CVAL(p,0) = ANN_GetBackupListResp;    /* backup list response */
 417
 418   p++;
 419   countptr = p;
 420
 421   SIVAL(p,1,info); /* the sender's unique info */
 422
 423   p += 5;
 424
 425   nameptr = p;
 426
 427 #if 0
 428
 429   for (d = subnetlist; d; d = d->next)
 430   {
 431       struct work_record *work;
 432
 433       for (work = d->workgrouplist; work; work = work->next)
 434         {
 435           struct server_record *s;
 436
 437           if (!strequal(work->work_group, work_name)) continue;
 438
 439           for (s = work->serverlist; s; s = s->next)
 440             {
 441               BOOL found = False;
 442               char *n;
 443
 444               if (s->serv.type & SV_TYPE_DOMAIN_ENUM) continue;
 445
 446               for (n = nameptr; n < p; n = skip_string(n, 1))
 447                 {
 448                   if (strequal(n, s->serv.name)) found = True;
 449                 }
 450
 451               if (found) continue; /* exclude names already added */
 452
 453               /* workgroup request: include all backup browsers in the list */
 454               /* domain request: include all domain members in the list */
 455
 456               if ((name_type == 0x1d && (s->serv.type & MASTER_TYPE)) ||
 457                       (name_type == 0x1b && (s->serv.type & DOMCTL_TYPE)))
 458                 {
 459                   DEBUG(4, ("%s ", s->serv.name));
 460
 461                   count++;
 462                   strcpy(p,s->serv.name);
 463                   strupper(p);
 464                   p = skip_string(p,1);
 465                 }
 466          }
 467         }
 468   }
 469
 470 #endif
 471
 472         count++;
 473         strcpy(p,myname);
 474         strupper(p);
 475         p = skip_string(p,1);
 476
 477   if (count == 0)
 478     {
 479       DEBUG(4, ("none\n"));
 480     }
 481   else
 482     {
 483       DEBUG(4, (" - count %d\n", count));
 484     }
 485
 486   CVAL(countptr, 0) = count;
 487
 488   {
 489     int len = PTR_DIFF(p, outbuf);
 490     debug_browse_data(outbuf, len);
 491   }
 492   send_mailslot_reply(BROWSE_MAILSLOT,ClientDGRAM,outbuf,PTR_DIFF(p,outbuf),
 493                       myname,theirname,0x0,0x0,ip,*iface_ip(ip));
 494 }
 495
 496
 497 /*******************************************************************
 498   process a send backup list request
 499
 500   A client sends a backup list request to ask for a list of servers on
 501   the net that maintain server lists for a domain. A server is then
 502   chosen from this list to send NetServerEnum commands to to list
 503   available servers.
 504
 505   Currently samba only sends back one name in the backup list, its
 506   own. For larger nets we'll have to add backups and send "become
 507   backup" requests occasionally.
 508   ******************************************************************/
 509 static void process_send_backup_list(struct packet_struct *p,char *buf)
 510 {
 511   struct dgram_packet *dgram = &p->packet.dgram;
 512   struct in_addr ip = dgram->header.source_ip;
 513   struct subnet_record *d;
 514   struct work_record *work;
 515
 516   int    token = CVAL(buf,0); /* sender's key index for the workgroup */
 517   uint32 info  = IVAL(buf,1); /* XXXX don't know: some sort of info */
 518   int name_type = dgram->dest_name.name_type;
 519
 520   if (same_context(dgram)) return;
 521
 522   if (name_type != 0x1b && name_type != 0x1d) {
 523     DEBUG(0,("backup request to wrong type %d from %s\n",
 524               name_type,inet_ntoa(ip)));
 525     return;
 526   }
 527
 528   for (d = subnetlist; d; d = d->next)
 529     {
 530       for (work = d->workgrouplist; work; work = work->next)
 531         {
 532           if (strequal(work->work_group, dgram->dest_name.name))
 533             {
 534               DEBUG(2,("sending backup list to %s %s id=%x\n",
 535                        namestr(&dgram->dest_name),inet_ntoa(ip),info));
 536
 537               send_backup_list(work->work_group,&dgram->source_name,
 538                                token,info,name_type,ip);
 539               return;
 540             }
 541         }
 542     }
 543 }
 544
 545
 546 /*******************************************************************
 547   process a reset browser state
 548
 549   diagnostic packet:
 550   0x1 - stop being a master browser and become a backup browser.
 551   0x2 - discard browse lists, stop being a master browser, try again.
 552   0x4 - stop being a master browser forever. no way. ain't gonna.
 553
 554   ******************************************************************/
 555 static void process_reset_browser(struct packet_struct *p,char *buf)
 556 {
 557   struct dgram_packet *dgram = &p->packet.dgram;
 558   int state = CVAL(buf,0);
 559
 560   DEBUG(1,("received diagnostic browser reset request to %s state=0x%X\n",
 561            namestr(&dgram->dest_name), state));
 562
 563   /* stop being a master but still deal with being a backup browser */
 564   if (state & 0x1)
 565     {
 566       struct subnet_record *d;
 567       for (d = subnetlist; d; d = d->next)
 568         {
 569           struct work_record *work;
 570           for (work = d->workgrouplist; work; work = work->next)
 571             {
 572               if (AM_MASTER(work))
 573                 {
 574                   become_nonmaster(d,work,SV_TYPE_DOMAIN_MASTER|SV_TYPE_MASTER_BROWSER);
 575                 }
 576             }
 577         }
 578     }
 579
 580   /* XXXX documentation inconsistency: the above description does not
 581      exactly tally with what is implemented for state & 0x2
 582    */
 583
 584   /* totally delete all servers and start afresh */
 585   if (state & 0x2)
 586     {
 587       struct subnet_record *d;
 588       for (d = subnetlist; d; d = d->next)
 589         {
 590           struct work_record *work;
 591           for (work=d->workgrouplist;work;work=remove_workgroup(d,work,True));
 592         }
 593       add_my_subnets(lp_workgroup());
 594     }
 595
 596   /* stop browsing altogether. i don't think this is a good idea! */
 597   if (state & 0x4)
 598     {
 599       DEBUG(1,("ignoring request to stop being a browser. sorry!\n"));
 600     }
 601 }
 602
 603 /*******************************************************************
 604   process a announcement request
 605
 606   clients send these when they want everyone to send an announcement
 607   immediately. This can cause quite a storm of packets!
 608   ******************************************************************/
 609 static void process_announce_request(struct packet_struct *p,char *buf)
 610 {
 611   struct dgram_packet *dgram = &p->packet.dgram;
 612   struct work_record *work;
 613   struct in_addr ip = dgram->header.source_ip;
 614   struct subnet_record *d = find_subnet(ip);
 615   int token = CVAL(buf,0);
 616   char *name = buf+1;
 617
 618   name[15] = 0;
 619
 620   DEBUG(3,("Announce request from %s to %s token=0x%X\n",
 621            name,namestr(&dgram->dest_name), token));
 622
 623   if (strequal(dgram->source_name.name,myname)) return;
 624
 625   /* XXXX BUG or FEATURE?: need to ensure that we are a member of
 626      this workgroup before announcing, particularly as we only
 627      respond on local interfaces anyway.
 628
 629      if (strequal(dgram->dest_name, lp_workgroup()) return; ???
 630    */
 631
 632   if (!d) return;
 633
 634   for (work = d->workgrouplist; work; work = work->next)
 635     {
 636      /* XXXX BUG: the destination name type should also be checked,
 637         not just the name. e.g if the name is WORKGROUP(0x1d) then
 638         we should only respond if we own that name */
 639
 640       if (strequal(dgram->dest_name.name,work->work_group))
 641         {
 642           work->needannounce = True;
 643         }
 644     }
 645 }
 646
 647
 648
 649 /****************************************************************************
 650 process a browse frame
 651 ****************************************************************************/
 652 void process_browse_packet(struct packet_struct *p,char *buf,int len)
 653 {
 654   int command = CVAL(buf,0);
 655   switch (command)
 656     {
 657     case ANN_HostAnnouncement:
 658     case ANN_DomainAnnouncement:
 659     case ANN_LocalMasterAnnouncement:
 660       {
 661         debug_browse_data(buf, len);
 662         process_announce(p,command,buf+1);
 663         break;
 664       }
 665
 666     case ANN_AnnouncementRequest:
 667       {
 668         process_announce_request(p,buf+1);
 669         break;
 670       }
 671
 672     case ANN_Election:
 673       {
 674         process_election(p,buf+1);
 675         break;
 676       }
 677
 678     case ANN_GetBackupListReq:
 679       {
 680         debug_browse_data(buf, len);
 681         process_send_backup_list(p,buf+1);
 682         break;
 683       }
 684
 685     case ANN_GetBackupListResp:
 686     {
 687         debug_browse_data(buf, len);
 688         process_rcv_backup_list(p, buf+1);
 689         break;
 690     }
 691
 692     case ANN_ResetBrowserState:
 693       {
 694         process_reset_browser(p, buf+1);
 695         break;
 696       }
 697
 698     case ANN_MasterAnnouncement:
 699       {
 700         process_master_announce(p,buf+1);
 701         break;
 702       }
 703
 704     default:
 705       {
 706         struct dgram_packet *dgram = &p->packet.dgram;
 707         DEBUG(4,("ignoring browse packet %d from %s %s to %s\n",
 708                  command, namestr(&dgram->source_name),
 709                  inet_ntoa(p->ip), namestr(&dgram->dest_name)));
 710       }
 711     }
 712 }
 713
 714