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       /* XXXX function needs work */
 356           continue;
 357
 358     if ((d = find_subnet(back_ip)))
 359         {
 360           struct subnet_record *d1;
 361           for (d1 = subnetlist; d1; d1 = d1->next)
 362           {
 363               struct work_record *work;
 364               for (work = d1->workgrouplist; work; work = work->next)
 365                 {
 366                   if (work->token == 0 /* token */)
 367                   {
 368                       queue_netbios_packet(d1,ClientNMB,NMB_QUERY,NAME_QUERY_SRV_CHK,
 369                                            work->work_group,0x1d,
 370                        0,0,0,NULL,NULL,
 371                                            False,False,back_ip,back_ip);
 372                       return;
 373                   }
 374                 }
 375           }
 376         }
 377   }
 378 }
 379
 380
 381 /****************************************************************************
 382   send a backup list response.
 383   **************************************************************************/
 384 static void send_backup_list(char *work_name, struct nmb_name *src_name,
 385                              int token, uint32 info,
 386                              int name_type, struct in_addr ip)
 387 {
 388   char outbuf[1024];
 389   char *p, *countptr, *nameptr;
 390   int count = 0;
 391   char *theirname = src_name->name;
 392
 393   DEBUG(3,("sending backup list of %s to %s: %s(%x) %s(%x)\n",
 394            work_name, inet_ntoa(ip),
 395            myname,0x0,theirname,0x0));
 396
 397   if (name_type == 0x1d)
 398     {
 399       DEBUG(4,("master browsers: "));
 400     }
 401   else if (name_type == 0x1b)
 402     {
 403       DEBUG(4,("domain controllers: "));
 404     }
 405   else
 406     {
 407       DEBUG(0,("backup request for unknown type %0x\n", name_type));
 408       return;
 409     }
 410
 411   bzero(outbuf,sizeof(outbuf));
 412   p = outbuf;
 413
 414   CVAL(p,0) = ANN_GetBackupListResp;    /* backup list response */
 415
 416   p++;
 417   countptr = p;
 418
 419   SIVAL(p,1,info); /* the sender's unique info */
 420
 421   p += 5;
 422
 423   nameptr = p;
 424
 425 #if 0
 426
 427   for (d = subnetlist; d; d = d->next)
 428   {
 429       struct work_record *work;
 430
 431       for (work = d->workgrouplist; work; work = work->next)
 432         {
 433           struct server_record *s;
 434
 435           if (!strequal(work->work_group, work_name)) continue;
 436
 437           for (s = work->serverlist; s; s = s->next)
 438             {
 439               BOOL found = False;
 440               char *n;
 441
 442               if (s->serv.type & SV_TYPE_DOMAIN_ENUM) continue;
 443
 444               for (n = nameptr; n < p; n = skip_string(n, 1))
 445                 {
 446                   if (strequal(n, s->serv.name)) found = True;
 447                 }
 448
 449               if (found) continue; /* exclude names already added */
 450
 451               /* workgroup request: include all backup browsers in the list */
 452               /* domain request: include all domain members in the list */
 453
 454               if ((name_type == 0x1d && (s->serv.type & MASTER_TYPE)) ||
 455                       (name_type == 0x1b && (s->serv.type & DOMCTL_TYPE)))
 456                 {
 457                   DEBUG(4, ("%s ", s->serv.name));
 458
 459                   count++;
 460                   strcpy(p,s->serv.name);
 461                   strupper(p);
 462                   p = skip_string(p,1);
 463                 }
 464          }
 465         }
 466   }
 467
 468 #endif
 469
 470         count++;
 471         strcpy(p,myname);
 472         strupper(p);
 473         p = skip_string(p,1);
 474
 475   if (count == 0)
 476     {
 477       DEBUG(4, ("none\n"));
 478     }
 479   else
 480     {
 481       DEBUG(4, (" - count %d\n", count));
 482     }
 483
 484   CVAL(countptr, 0) = count;
 485
 486   {
 487     int len = PTR_DIFF(p, outbuf);
 488     debug_browse_data(outbuf, len);
 489   }
 490   send_mailslot_reply(BROWSE_MAILSLOT,ClientDGRAM,outbuf,PTR_DIFF(p,outbuf),
 491                       myname,theirname,0x0,0x0,ip,*iface_ip(ip));
 492 }
 493
 494
 495 /*******************************************************************
 496   process a send backup list request
 497
 498   A client sends a backup list request to ask for a list of servers on
 499   the net that maintain server lists for a domain. A server is then
 500   chosen from this list to send NetServerEnum commands to to list
 501   available servers.
 502
 503   Currently samba only sends back one name in the backup list, its
 504   own. For larger nets we'll have to add backups and send "become
 505   backup" requests occasionally.
 506   ******************************************************************/
 507 static void process_send_backup_list(struct packet_struct *p,char *buf)
 508 {
 509   struct dgram_packet *dgram = &p->packet.dgram;
 510   struct in_addr ip = dgram->header.source_ip;
 511   struct subnet_record *d;
 512   struct work_record *work;
 513
 514   int    token = CVAL(buf,0); /* sender's key index for the workgroup */
 515   uint32 info  = IVAL(buf,1); /* XXXX don't know: some sort of info */
 516   int name_type = dgram->dest_name.name_type;
 517
 518   if (same_context(dgram)) return;
 519
 520   if (name_type != 0x1b && name_type != 0x1d) {
 521     DEBUG(0,("backup request to wrong type %d from %s\n",
 522               name_type,inet_ntoa(ip)));
 523     return;
 524   }
 525
 526   for (d = subnetlist; d; d = d->next)
 527     {
 528       for (work = d->workgrouplist; work; work = work->next)
 529         {
 530           if (strequal(work->work_group, dgram->dest_name.name))
 531             {
 532               DEBUG(2,("sending backup list to %s %s id=%x\n",
 533                        namestr(&dgram->dest_name),inet_ntoa(ip),info));
 534
 535               send_backup_list(work->work_group,&dgram->source_name,
 536                                token,info,name_type,ip);
 537               return;
 538             }
 539         }
 540     }
 541 }
 542
 543
 544 /*******************************************************************
 545   process a reset browser state
 546
 547   diagnostic packet:
 548   0x1 - stop being a master browser and become a backup browser.
 549   0x2 - discard browse lists, stop being a master browser, try again.
 550   0x4 - stop being a master browser forever. no way. ain't gonna.
 551
 552   ******************************************************************/
 553 static void process_reset_browser(struct packet_struct *p,char *buf)
 554 {
 555   struct dgram_packet *dgram = &p->packet.dgram;
 556   int state = CVAL(buf,0);
 557
 558   DEBUG(1,("received diagnostic browser reset request to %s state=0x%X\n",
 559            namestr(&dgram->dest_name), state));
 560
 561   /* stop being a master but still deal with being a backup browser */
 562   if (state & 0x1)
 563     {
 564       struct subnet_record *d;
 565       for (d = subnetlist; d; d = d->next)
 566         {
 567           struct work_record *work;
 568           for (work = d->workgrouplist; work; work = work->next)
 569             {
 570               if (AM_MASTER(work))
 571                 {
 572                   become_nonmaster(d,work,SV_TYPE_DOMAIN_MASTER|SV_TYPE_MASTER_BROWSER);
 573                 }
 574             }
 575         }
 576     }
 577
 578   /* XXXX documentation inconsistency: the above description does not
 579      exactly tally with what is implemented for state & 0x2
 580    */
 581
 582   /* totally delete all servers and start afresh */
 583   if (state & 0x2)
 584     {
 585       struct subnet_record *d;
 586       for (d = subnetlist; d; d = d->next)
 587         {
 588           struct work_record *work;
 589           for (work=d->workgrouplist;work;work=remove_workgroup(d,work,True));
 590         }
 591       add_my_subnets(lp_workgroup());
 592     }
 593
 594   /* stop browsing altogether. i don't think this is a good idea! */
 595   if (state & 0x4)
 596     {
 597       DEBUG(1,("ignoring request to stop being a browser. sorry!\n"));
 598     }
 599 }
 600
 601 /*******************************************************************
 602   process a announcement request
 603
 604   clients send these when they want everyone to send an announcement
 605   immediately. This can cause quite a storm of packets!
 606   ******************************************************************/
 607 static void process_announce_request(struct packet_struct *p,char *buf)
 608 {
 609   struct dgram_packet *dgram = &p->packet.dgram;
 610   struct work_record *work;
 611   struct in_addr ip = dgram->header.source_ip;
 612   struct subnet_record *d = find_subnet(ip);
 613   int token = CVAL(buf,0);
 614   char *name = buf+1;
 615
 616   name[15] = 0;
 617
 618   DEBUG(3,("Announce request from %s to %s token=0x%X\n",
 619            name,namestr(&dgram->dest_name), token));
 620
 621   if (strequal(dgram->source_name.name,myname)) return;
 622
 623   /* XXXX BUG or FEATURE?: need to ensure that we are a member of
 624      this workgroup before announcing, particularly as we only
 625      respond on local interfaces anyway.
 626
 627      if (strequal(dgram->dest_name, lp_workgroup()) return; ???
 628    */
 629
 630   if (!d) return;
 631
 632   for (work = d->workgrouplist; work; work = work->next)
 633     {
 634      /* XXXX BUG: the destination name type should also be checked,
 635         not just the name. e.g if the name is WORKGROUP(0x1d) then
 636         we should only respond if we own that name */
 637
 638       if (strequal(dgram->dest_name.name,work->work_group))
 639         {
 640           work->needannounce = True;
 641         }
 642     }
 643 }
 644
 645
 646
 647 /****************************************************************************
 648 process a browse frame
 649 ****************************************************************************/
 650 void process_browse_packet(struct packet_struct *p,char *buf,int len)
 651 {
 652   int command = CVAL(buf,0);
 653   switch (command)
 654     {
 655     case ANN_HostAnnouncement:
 656     case ANN_DomainAnnouncement:
 657     case ANN_LocalMasterAnnouncement:
 658       {
 659         debug_browse_data(buf, len);
 660         process_announce(p,command,buf+1);
 661         break;
 662       }
 663
 664     case ANN_AnnouncementRequest:
 665       {
 666         process_announce_request(p,buf+1);
 667         break;
 668       }
 669
 670     case ANN_Election:
 671       {
 672         process_election(p,buf+1);
 673         break;
 674       }
 675
 676     case ANN_GetBackupListReq:
 677       {
 678         debug_browse_data(buf, len);
 679         process_send_backup_list(p,buf+1);
 680         break;
 681       }
 682
 683     case ANN_GetBackupListResp:
 684     {
 685         debug_browse_data(buf, len);
 686         process_rcv_backup_list(p, buf+1);
 687         break;
 688     }
 689
 690     case ANN_ResetBrowserState:
 691       {
 692         process_reset_browser(p, buf+1);
 693         break;
 694       }
 695
 696     case ANN_MasterAnnouncement:
 697       {
 698         process_master_announce(p,buf+1);
 699         break;
 700       }
 701
 702     default:
 703       {
 704         struct dgram_packet *dgram = &p->packet.dgram;
 705         DEBUG(4,("ignoring browse packet %d from %s %s to %s\n",
 706                  command, namestr(&dgram->source_name),
 707                  inet_ntoa(p->ip), namestr(&dgram->dest_name)));
 708       }
 709     }
 710 }
 711
 712