source3/nmbd/nmbd_incomingdgrams.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    NBT netbios routines and daemon - version 2
   4    Copyright (C) Andrew Tridgell 1994-1998
   5    Copyright (C) Luke Kenneth Casson Leighton 1994-1998
   6    Copyright (C) Jeremy Allison 1994-1998
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  20
  21 */
  22
  23 #include "includes.h"
  24 #include "../librpc/gen_ndr/svcctl.h"
  25 #include "nmbd/nmbd.h"
  26
  27 extern bool found_lm_clients;
  28
  29 #if 0
  30
  31 /* XXXX note: This function is currently unsuitable for use, as it
  32    does not properly check that a server is in a fit state to become
  33    a backup browser before asking it to be one.
  34    The code is left here to be worked on at a later date.
  35 */
  36
  37 /****************************************************************************
  38 Tell a server to become a backup browser
  39 **************************************************************************/
  40
  41 void tell_become_backup(void)
  42 {
  43   struct subnet_record *subrec;
  44   for (subrec = FIRST_SUBNET; subrec; subrec = NEXT_SUBNET_EXCLUDING_UNICAST(subrec))
  45   {
  46     struct work_record *work;
  47     for (work = subrec->workgrouplist; work; work = work->next)
  48     {
  49       struct server_record *servrec;
  50       int num_servers = 0;
  51       int num_backups = 0;
  52
  53       for (servrec = work->serverlist; servrec; servrec = servrec->next)
  54       {
  55         num_servers++;
  56
  57         if (is_myname(servrec->serv.name))
  58           continue;
  59
  60         if (servrec->serv.type & SV_TYPE_BACKUP_BROWSER)
  61         {
  62           num_backups++;
  63           continue;
  64         }
  65
  66         if (servrec->serv.type & SV_TYPE_MASTER_BROWSER)
  67           continue;
  68
  69         if (!(servrec->serv.type & SV_TYPE_POTENTIAL_BROWSER))
  70           continue;
  71
  72         DEBUG(3,("num servers: %d num backups: %d\n",
  73               num_servers, num_backups));
  74
  75         /* make first server a backup server. thereafter make every
  76            tenth server a backup server */
  77         if (num_backups != 0 && (num_servers+9) / num_backups > 10)
  78           continue;
  79
  80         DEBUG(2,("sending become backup to %s %s for %s\n",
  81              servrec->serv.name, inet_ntoa(subrec->bcast_ip),
  82              work->work_group));
  83
  84         /* type 11 request from MYNAME(20) to WG(1e) for SERVER */
  85         do_announce_request(servrec->serv.name, work->work_group,
  86               ANN_BecomeBackup, 0x20, 0x1e, subrec->bcast_ip);
  87       }
  88     }
  89   }
  90 }
  91 #endif
  92
  93 /*******************************************************************
  94   Process an incoming host announcement packet.
  95 *******************************************************************/
  96
  97 void process_host_announce(struct subnet_record *subrec, struct packet_struct *p, const char *buf)
  98 {
  99         struct dgram_packet *dgram = &p->packet.dgram;
 100         int ttl = IVAL(buf,1)/1000;
 101         unstring announce_name;
 102         uint32_t servertype = IVAL(buf,23);
 103         fstring comment;
 104         struct work_record *work;
 105         struct server_record *servrec;
 106         unstring work_name;
 107         unstring source_name;
 108         ZERO_STRUCT(source_name);
 109         ZERO_STRUCT(announce_name);
 110
 111         pull_ascii_fstring(comment, buf+31);
 112
 113         pull_ascii_nstring(announce_name, sizeof(announce_name), buf+5);
 114         pull_ascii_nstring(source_name, sizeof(source_name), dgram->source_name.name);
 115
 116         DEBUG(3,("process_host_announce: from %s<%02x> IP %s to \
 117 %s for server %s.\n", source_name, source_name[15], inet_ntoa(p->ip),
 118                         nmb_namestr(&dgram->dest_name),announce_name));
 119
 120         DEBUG(5,("process_host_announce: ttl=%d server type=%08x comment=%s\n",
 121                 ttl, servertype,comment));
 122
 123         /* Filter servertype to remove impossible bits. */
 124         servertype &= ~(SV_TYPE_LOCAL_LIST_ONLY|SV_TYPE_DOMAIN_ENUM);
 125
 126         /* A host announcement must be sent to the name WORKGROUP<1d>. */
 127         if(dgram->dest_name.name_type != 0x1d) {
 128                 DEBUG(2,("process_host_announce: incorrect name type for destination from IP %s \
 129 (was %02x) should be 0x1d. Allowing packet anyway.\n",
 130                         inet_ntoa(p->ip), dgram->dest_name.name_type));
 131                 /* Change it so it was. */
 132                 dgram->dest_name.name_type = 0x1d;
 133         }
 134
 135         /* For a host announce the workgroup name is the destination name. */
 136         pull_ascii_nstring(work_name, sizeof(work_name), dgram->dest_name.name);
 137
 138         /*
 139          * Syntax servers version 5.1 send HostAnnounce packets to
 140          * *THE WRONG NAME*. They send to LOCAL_MASTER_BROWSER_NAME<00>
 141          * instead of WORKGROUP<1d> name. So to fix this we check if
 142          * the workgroup name is our own name, and if so change it
 143          * to be our primary workgroup name.
 144          */
 145
 146         if(strequal(work_name, lp_netbios_name()))
 147                 unstrcpy(work_name,lp_workgroup());
 148
 149         /*
 150          * We are being very agressive here in adding a workgroup
 151          * name on the basis of a host announcing itself as being
 152          * in that workgroup. Maybe we should wait for the workgroup
 153          * announce instead ? JRA.
 154          */
 155
 156         work = find_workgroup_on_subnet(subrec, work_name);
 157
 158         if(servertype != 0) {
 159                 if (work ==NULL ) {
 160                         /* We have no record of this workgroup. Add it. */
 161                         if((work = create_workgroup_on_subnet(subrec, work_name, ttl))==NULL)
 162                                 goto done;
 163                 }
 164
 165                 if((servrec = find_server_in_workgroup( work, announce_name))==NULL) {
 166                         /* If this server is not already in the workgroup, add it. */
 167                         create_server_on_workgroup(work, announce_name,
 168                                 servertype|SV_TYPE_LOCAL_LIST_ONLY,
 169                                 ttl, comment);
 170                 } else {
 171                         /* Update the record. */
 172                         servrec->serv.type = servertype|SV_TYPE_LOCAL_LIST_ONLY;
 173                         update_server_ttl( servrec, ttl);
 174                         strlcpy(servrec->serv.comment,comment,sizeof(servrec->serv.comment));
 175                 }
 176         } else {
 177                 /*
 178                  * This server is announcing it is going down. Remove it from the
 179                  * workgroup.
 180                  */
 181                 if(!is_myname(announce_name) && (work != NULL) &&
 182                                 ((servrec = find_server_in_workgroup( work, announce_name))!=NULL)) {
 183                         remove_server_from_workgroup( work, servrec);
 184                 }
 185         }
 186
 187         subrec->work_changed = True;
 188 done:
 189         return;
 190 }
 191
 192 /*******************************************************************
 193   Process an incoming WORKGROUP announcement packet.
 194 *******************************************************************/
 195
 196 void process_workgroup_announce(struct subnet_record *subrec, struct packet_struct *p, const char *buf)
 197 {
 198         struct dgram_packet *dgram = &p->packet.dgram;
 199         int ttl = IVAL(buf,1)/1000;
 200         unstring workgroup_announce_name;
 201         unstring master_name;
 202         uint32_t servertype = IVAL(buf,23);
 203         struct work_record *work;
 204         unstring source_name;
 205         unstring dest_name;
 206
 207         pull_ascii_nstring(workgroup_announce_name,sizeof(workgroup_announce_name),buf+5);
 208         pull_ascii_nstring(master_name,sizeof(master_name),buf+31);
 209         pull_ascii_nstring(source_name,sizeof(source_name),dgram->source_name.name);
 210         pull_ascii_nstring(dest_name,sizeof(dest_name),dgram->dest_name.name);
 211
 212         DEBUG(3,("process_workgroup_announce: from %s<%02x> IP %s to \
 213 %s for workgroup %s.\n", source_name, source_name[15], inet_ntoa(p->ip),
 214                         nmb_namestr(&dgram->dest_name),workgroup_announce_name));
 215
 216         DEBUG(5,("process_workgroup_announce: ttl=%d server type=%08x master browser=%s\n",
 217                 ttl, servertype, master_name));
 218
 219         /* Workgroup announcements must only go to the MSBROWSE name. */
 220         if (!strequal(dest_name, MSBROWSE) || (dgram->dest_name.name_type != 0x1)) {
 221                 DEBUG(0,("process_workgroup_announce: from IP %s should be to __MSBROWSE__<0x01> not %s\n",
 222                         inet_ntoa(p->ip), nmb_namestr(&dgram->dest_name)));
 223                 goto done;
 224         }
 225
 226         if ((work = find_workgroup_on_subnet(subrec, workgroup_announce_name))==NULL) {
 227                 /* We have no record of this workgroup. Add it. */
 228                 if((work = create_workgroup_on_subnet(subrec, workgroup_announce_name, ttl))==NULL)
 229                         goto done;
 230         } else {
 231                 /* Update the workgroup death_time. */
 232                 update_workgroup_ttl(work, ttl);
 233         }
 234
 235         if(*work->local_master_browser_name == '\0') {
 236                 /* Set the master browser name. */
 237                 set_workgroup_local_master_browser_name( work, master_name );
 238         }
 239
 240         subrec->work_changed = True;
 241
 242 done:
 243         return;
 244 }
 245
 246 /*******************************************************************
 247   Process an incoming local master browser announcement packet.
 248 *******************************************************************/
 249
 250 void process_local_master_announce(struct subnet_record *subrec, struct packet_struct *p, const char *buf)
 251 {
 252         struct dgram_packet *dgram = &p->packet.dgram;
 253         int ttl = IVAL(buf,1)/1000;
 254         unstring server_name;
 255         uint32_t servertype = IVAL(buf,23);
 256         fstring comment;
 257         unstring work_name;
 258         struct work_record *work = NULL;
 259         struct server_record *servrec;
 260         unstring source_name;
 261
 262         pull_ascii_nstring(server_name,sizeof(server_name),buf+5);
 263         pull_ascii_fstring(comment, buf+31);
 264         pull_ascii_nstring(source_name, sizeof(source_name), dgram->source_name.name);
 265         pull_ascii_nstring(work_name, sizeof(work_name), dgram->dest_name.name);
 266
 267         DEBUG(3,("process_local_master_announce: from %s<%02x> IP %s to \
 268 %s for server %s.\n", source_name, source_name[15], inet_ntoa(p->ip),
 269                 nmb_namestr(&dgram->dest_name),server_name));
 270
 271         DEBUG(5,("process_local_master_announce: ttl=%d server type=%08x comment=%s\n",
 272                 ttl, servertype, comment));
 273
 274         /* A local master announcement must be sent to the name WORKGROUP<1e>. */
 275         if(dgram->dest_name.name_type != 0x1e) {
 276                 DEBUG(0,("process_local_master_announce: incorrect name type for destination from IP %s \
 277 (was %02x) should be 0x1e. Ignoring packet.\n",
 278                         inet_ntoa(p->ip), dgram->dest_name.name_type));
 279                 goto done;
 280         }
 281
 282         /* Filter servertype to remove impossible bits. */
 283         servertype &= ~(SV_TYPE_LOCAL_LIST_ONLY|SV_TYPE_DOMAIN_ENUM);
 284
 285         /* For a local master announce the workgroup name is the destination name. */
 286
 287         if ((work = find_workgroup_on_subnet(subrec, work_name))==NULL) {
 288                 /* Don't bother adding if it's a local master release announce. */
 289                 if(servertype == 0)
 290                         goto done;
 291
 292                 /* We have no record of this workgroup. Add it. */
 293                 if((work = create_workgroup_on_subnet(subrec, work_name, ttl))==NULL)
 294                         goto done;
 295         }
 296
 297         /* If we think we're the local master browser for this workgroup,
 298                 we should never have got this packet. We don't see our own
 299                 packets.
 300         */
 301         if(AM_LOCAL_MASTER_BROWSER(work)) {
 302                 DEBUG(0,("process_local_master_announce: Server %s at IP %s is announcing itself as \
 303 a local master browser for workgroup %s and we think we are master. Forcing election.\n",
 304                         server_name, inet_ntoa(p->ip), work_name));
 305
 306                 /* Samba nmbd versions 1.9.17 to 1.9.17p4 have a bug in that when
 307                  they have become a local master browser once, they will never
 308                  stop sending local master announcements. To fix this we send
 309                  them a reset browser packet, with level 0x2 on the __SAMBA__
 310                  name that only they should be listening to. */
 311
 312                 send_browser_reset( 0x2, "__SAMBA__" , 0x20, p->ip);
 313
 314                 /* We should demote ourself and force an election. */
 315
 316                 unbecome_local_master_browser( subrec, work, True);
 317
 318                 /* The actual election requests are handled in nmbd_election.c */
 319                 goto done;
 320         }
 321
 322         /* Find the server record on this workgroup. If it doesn't exist, add it. */
 323
 324         if(servertype != 0) {
 325                 if((servrec = find_server_in_workgroup( work, server_name))==NULL) {
 326                         /* If this server is not already in the workgroup, add it. */
 327                         create_server_on_workgroup(work, server_name,
 328                                 servertype|SV_TYPE_LOCAL_LIST_ONLY,
 329                                 ttl, comment);
 330                 } else {
 331                         /* Update the record. */
 332                         if (servrec->serv.type !=
 333                                         (servertype|SV_TYPE_LOCAL_LIST_ONLY)) {
 334                                 servrec->serv.type =
 335                                         servertype|SV_TYPE_LOCAL_LIST_ONLY;
 336                                 subrec->work_changed = true;
 337                         }
 338                         if (!strequal(servrec->serv.comment,comment)) {
 339                                 strlcpy(servrec->serv.comment,
 340                                         comment,
 341                                         sizeof(servrec->serv.comment));
 342                                 subrec->work_changed = true;
 343                         }
 344                         update_server_ttl(servrec, ttl);
 345                 }
 346
 347                 if (!strequal(work->local_master_browser_name, server_name)) {
 348                         set_workgroup_local_master_browser_name( work, server_name );
 349                         subrec->work_changed = true;
 350                 }
 351         } else {
 352                 /*
 353                  * This server is announcing it is going down. Remove it from the
 354                  * workgroup.
 355                  */
 356                 if(!is_myname(server_name) &&
 357                                 ((servrec = find_server_in_workgroup( work, server_name))!=NULL)) {
 358                         remove_server_from_workgroup( work, servrec);
 359                 }
 360         }
 361
 362 done:
 363         return;
 364 }
 365
 366 /*******************************************************************
 367   Process a domain master announcement frame.
 368   Domain master browsers receive these from local masters. The Domain
 369   master should then issue a sync with the local master, asking for
 370   that machines local server list.
 371 ******************************************************************/
 372
 373 void process_master_browser_announce(struct subnet_record *subrec,
 374                                      struct packet_struct *p,const char *buf)
 375 {
 376         unstring local_master_name;
 377         struct work_record *work;
 378         struct browse_cache_record *browrec;
 379
 380         pull_ascii_nstring(local_master_name,sizeof(local_master_name),buf);
 381
 382         DEBUG(3,("process_master_browser_announce: Local master announce from %s IP %s.\n",
 383                 local_master_name, inet_ntoa(p->ip)));
 384
 385         if (!lp_domain_master()) {
 386                 DEBUG(0,("process_master_browser_announce: Not configured as domain \
 387 master - ignoring master announce.\n"));
 388                 goto done;
 389         }
 390
 391         if((work = find_workgroup_on_subnet(subrec, lp_workgroup())) == NULL) {
 392                 DEBUG(0,("process_master_browser_announce: Cannot find workgroup %s on subnet %s\n",
 393                         lp_workgroup(), subrec->subnet_name));
 394                 goto done;
 395         }
 396
 397         if(!AM_DOMAIN_MASTER_BROWSER(work)) {
 398                 DEBUG(0,("process_master_browser_announce: Local master announce made to us from \
 399 %s IP %s and we are not a domain master browser.\n", local_master_name, inet_ntoa(p->ip)));
 400                 goto done;
 401         }
 402
 403         /* Add this host as a local master browser entry on the browse lists.
 404                 This causes a sync request to be made to it at a later date.
 405         */
 406
 407         if((browrec = find_browser_in_lmb_cache( local_master_name )) == NULL) {
 408                 /* Add it. */
 409                 create_browser_in_lmb_cache( work->work_group, local_master_name, p->ip);
 410         } else {
 411                 update_browser_death_time(browrec);
 412         }
 413
 414 done:
 415         return;
 416 }
 417
 418 /*******************************************************************
 419   Process an incoming LanMan host announcement packet.
 420 *******************************************************************/
 421
 422 void process_lm_host_announce(struct subnet_record *subrec, struct packet_struct *p, const char *buf, int len)
 423 {
 424         struct dgram_packet *dgram = &p->packet.dgram;
 425         uint32_t servertype = IVAL(buf,1);
 426         int osmajor=CVAL(buf,5);           /* major version of node software */
 427         int osminor=CVAL(buf,6);           /* minor version of node software */
 428         int ttl = SVAL(buf,7);
 429         unstring announce_name;
 430         struct work_record *work;
 431         struct server_record *servrec;
 432         unstring work_name;
 433         unstring source_name;
 434         fstring comment;
 435         char *s = get_safe_str_ptr(buf,len,discard_const_p(char, buf),9);
 436
 437         if (!s) {
 438                 goto done;
 439         }
 440         s = skip_string(buf,len,s);
 441         if (!s) {
 442                 goto done;
 443         }
 444         pull_ascii(comment, s, sizeof(fstring), 43, STR_TERMINATE);
 445
 446         pull_ascii_nstring(announce_name,sizeof(announce_name),buf+9);
 447         pull_ascii_nstring(source_name,sizeof(source_name),dgram->source_name.name);
 448         /* For a LanMan host announce the workgroup name is the destination name. */
 449         pull_ascii_nstring(work_name,sizeof(work_name),dgram->dest_name.name);
 450
 451         DEBUG(3,("process_lm_host_announce: LM Announcement from %s IP %s to \
 452 %s for server %s.\n", nmb_namestr(&dgram->source_name), inet_ntoa(p->ip),
 453                 nmb_namestr(&dgram->dest_name),announce_name));
 454
 455         DEBUG(5,("process_lm_host_announce: os=(%d,%d) ttl=%d server type=%08x comment=%s\n",
 456                 osmajor, osminor, ttl, servertype,comment));
 457
 458         if ((osmajor < 36) || (osmajor > 38) || (osminor !=0)) {
 459                 DEBUG(5,("process_lm_host_announce: LM Announcement packet does not \
 460 originate from OS/2 Warp client. Ignoring packet.\n"));
 461                 /* Could have been from a Windows machine (with its LM Announce enabled),
 462                         or a Samba server. Then don't disrupt the current browse list. */
 463                 goto done;
 464         }
 465
 466         /* Filter servertype to remove impossible bits. */
 467         servertype &= ~(SV_TYPE_LOCAL_LIST_ONLY|SV_TYPE_DOMAIN_ENUM);
 468
 469         /* A LanMan host announcement must be sent to the name WORKGROUP<00>. */
 470         if(dgram->dest_name.name_type != 0x00) {
 471                 DEBUG(2,("process_lm_host_announce: incorrect name type for destination from IP %s \
 472 (was %02x) should be 0x00. Allowing packet anyway.\n",
 473                         inet_ntoa(p->ip), dgram->dest_name.name_type));
 474                 /* Change it so it was. */
 475                 dgram->dest_name.name_type = 0x00;
 476         }
 477
 478         /*
 479          * Syntax servers version 5.1 send HostAnnounce packets to
 480          * *THE WRONG NAME*. They send to LOCAL_MASTER_BROWSER_NAME<00>
 481          * instead of WORKGROUP<1d> name. So to fix this we check if
 482          * the workgroup name is our own name, and if so change it
 483          * to be our primary workgroup name. This code is probably
 484          * not needed in the LanMan announce code, but it won't hurt.
 485          */
 486
 487         if(strequal(work_name, lp_netbios_name()))
 488                 unstrcpy(work_name,lp_workgroup());
 489
 490         /*
 491          * We are being very agressive here in adding a workgroup
 492          * name on the basis of a host announcing itself as being
 493          * in that workgroup. Maybe we should wait for the workgroup
 494          * announce instead ? JRA.
 495          */
 496
 497         work = find_workgroup_on_subnet(subrec, work_name);
 498
 499         if(servertype != 0) {
 500                 if (work == NULL) {
 501                         /* We have no record of this workgroup. Add it. */
 502                         if((work = create_workgroup_on_subnet(subrec, work_name, ttl))==NULL)
 503                                 goto done;
 504                 }
 505
 506                 if((servrec = find_server_in_workgroup( work, announce_name))==NULL) {
 507                         /* If this server is not already in the workgroup, add it. */
 508                         create_server_on_workgroup(work, announce_name,
 509                                         servertype|SV_TYPE_LOCAL_LIST_ONLY,
 510                                         ttl, comment);
 511                 } else {
 512                         /* Update the record. */
 513                         servrec->serv.type = servertype|SV_TYPE_LOCAL_LIST_ONLY;
 514                         update_server_ttl( servrec, ttl);
 515                         strlcpy(servrec->serv.comment,comment,sizeof(servrec->serv.comment));
 516                 }
 517         } else {
 518                 /*
 519                  * This server is announcing it is going down. Remove it from the
 520                  * workgroup.
 521                  */
 522                 if(!is_myname(announce_name) && (work != NULL) &&
 523                                 ((servrec = find_server_in_workgroup( work, announce_name))!=NULL)) {
 524                         remove_server_from_workgroup( work, servrec);
 525                 }
 526         }
 527
 528         subrec->work_changed = True;
 529         found_lm_clients = True;
 530
 531 done:
 532         return;
 533 }
 534
 535 /****************************************************************************
 536   Send a backup list response.
 537 *****************************************************************************/
 538
 539 static void send_backup_list_response(struct subnet_record *subrec,
 540                                       struct work_record *work,
 541                                       struct nmb_name *send_to_name,
 542                                       unsigned char max_number_requested,
 543                                       uint32_t token, struct in_addr sendto_ip,
 544                                       int port)
 545 {
 546         char outbuf[1024];
 547         char *p, *countptr;
 548         unsigned int count = 0;
 549         unstring send_to_namestr;
 550 #if 0
 551   struct server_record *servrec;
 552 #endif
 553         unstring myname;
 554
 555         memset(outbuf,'\0',sizeof(outbuf));
 556
 557         DEBUG(3,("send_backup_list_response: sending backup list for workgroup %s to %s IP %s\n",
 558                 work->work_group, nmb_namestr(send_to_name), inet_ntoa(sendto_ip)));
 559
 560         p = outbuf;
 561
 562         SCVAL(p,0,ANN_GetBackupListResp); /* Backup list response opcode. */
 563         p++;
 564
 565         countptr = p;
 566         p++;
 567
 568         SIVAL(p,0,token); /* The sender's unique info. */
 569         p += 4;
 570
 571         /* We always return at least one name - our own. */
 572         count = 1;
 573         unstrcpy(myname, lp_netbios_name());
 574         if (!strupper_m(myname)) {
 575                 DEBUG(4,("strupper_m %s failed\n", myname));
 576                 return;
 577         }
 578         myname[15]='\0';
 579         push_ascii(p, myname, sizeof(outbuf)-PTR_DIFF(p,outbuf)-1, STR_TERMINATE);
 580
 581         p = skip_string(outbuf,sizeof(outbuf),p);
 582
 583         /* Look for backup browsers in this workgroup. */
 584
 585 #if 0
 586   /* we don't currently send become_backup requests so we should never
 587      send any other servers names out as backups for our
 588      workgroup. That's why this is commented out (tridge) */
 589
 590   /*
 591    * NB. Note that the struct work_record here is not neccessarily
 592    * attached to the subnet *subrec.
 593    */
 594
 595   for (servrec = work->serverlist; servrec; servrec = servrec->next)
 596   {
 597     int len = PTR_DIFF(p, outbuf);
 598     if((sizeof(outbuf) - len) < 16)
 599       break;
 600
 601     if(count >= (unsigned int)max_number_requested)
 602       break;
 603
 604     if(strnequal(servrec->serv.name, lp_netbios_name(),15))
 605       continue;
 606
 607     if(!(servrec->serv.type & SV_TYPE_BACKUP_BROWSER))
 608       continue;
 609
 610     strlcpy(p, servrec->serv.name, 16);
 611     strupper_m(p);
 612     count++;
 613
 614     DEBUG(5,("send_backup_list_response: Adding server %s number %d\n",
 615               p, count));
 616
 617     p = skip_string(outbuf,sizeof(outbuf),p);
 618   }
 619 #endif
 620
 621         SCVAL(countptr, 0, count);
 622
 623         pull_ascii_nstring(send_to_namestr, sizeof(send_to_namestr), send_to_name->name);
 624
 625         DEBUG(4,("send_backup_list_response: sending response to %s<00> IP %s with %d servers.\n",
 626                 send_to_namestr, inet_ntoa(sendto_ip), count));
 627
 628         send_mailslot(True, BROWSE_MAILSLOT,
 629                 outbuf,PTR_DIFF(p,outbuf),
 630                 lp_netbios_name(), 0,
 631                 send_to_namestr,0,
 632                 sendto_ip, subrec->myip, port);
 633 }
 634
 635 /*******************************************************************
 636   Process a send backup list request packet.
 637
 638   A client sends a backup list request to ask for a list of servers on
 639   the net that maintain server lists for a domain. A server is then
 640   chosen from this list to send NetServerEnum commands to to list
 641   available servers.
 642
 643 ********************************************************************/
 644
 645 void process_get_backup_list_request(struct subnet_record *subrec,
 646                                      struct packet_struct *p,const char *buf)
 647 {
 648         struct dgram_packet *dgram = &p->packet.dgram;
 649         struct work_record *work;
 650         unsigned char max_number_requested = CVAL(buf,0);
 651         uint32_t token = IVAL(buf,1); /* Sender's key index for the workgroup. */
 652         int name_type = dgram->dest_name.name_type;
 653         unstring workgroup_name;
 654         struct subnet_record *search_subrec = subrec;
 655
 656         pull_ascii_nstring(workgroup_name, sizeof(workgroup_name), dgram->dest_name.name);
 657
 658         DEBUG(3,("process_get_backup_list_request: request from %s IP %s to %s.\n",
 659                 nmb_namestr(&dgram->source_name), inet_ntoa(p->ip),
 660                 nmb_namestr(&dgram->dest_name)));
 661
 662         /* We have to be a master browser, or a domain master browser
 663                 for the requested workgroup. That means it must be our
 664                 workgroup. */
 665
 666         if(strequal(workgroup_name, lp_workgroup()) == False) {
 667                 DEBUG(7,("process_get_backup_list_request: Ignoring announce request for workgroup %s.\n",
 668                         workgroup_name));
 669                 goto done;
 670         }
 671
 672         if((work = find_workgroup_on_subnet(search_subrec, workgroup_name)) == NULL) {
 673                 DEBUG(0,("process_get_backup_list_request: Cannot find workgroup %s on \
 674 subnet %s.\n", workgroup_name, search_subrec->subnet_name));
 675                 goto done;
 676         }
 677
 678         /*
 679          * If the packet was sent to WORKGROUP<1b> instead
 680          * of WORKGROUP<1d> then it was unicast to us a domain master
 681          * browser. Change search subrec to unicast.
 682          */
 683
 684         if(name_type == 0x1b) {
 685                 /* We must be a domain master browser in order to
 686                         process this packet. */
 687
 688                 if(!AM_DOMAIN_MASTER_BROWSER(work)) {
 689                         DEBUG(0,("process_get_backup_list_request: domain list requested for workgroup %s \
 690 and I am not a domain master browser.\n", workgroup_name));
 691                         goto done;
 692                 }
 693
 694                 search_subrec = unicast_subnet;
 695         } else if (name_type == 0x1d) {
 696                 /* We must be a local master browser in order to process this packet. */
 697
 698                 if(!AM_LOCAL_MASTER_BROWSER(work)) {
 699                         DEBUG(0,("process_get_backup_list_request: domain list requested for workgroup %s \
 700 and I am not a local master browser.\n", workgroup_name));
 701                         goto done;
 702                 }
 703         } else {
 704                 DEBUG(0,("process_get_backup_list_request: Invalid name type %x - should be 0x1b or 0x1d.\n",
 705                         name_type));
 706                 goto done;
 707         }
 708
 709         send_backup_list_response(subrec, work, &dgram->source_name,
 710                         max_number_requested, token, p->ip, p->port);
 711
 712 done:
 713         return;
 714 }
 715
 716 /*******************************************************************
 717   Process a reset browser state packet.
 718
 719   Diagnostic packet:
 720   0x1 - Stop being a master browser and become a backup browser.
 721   0x2 - Discard browse lists, stop being a master browser, try again.
 722   0x4 - Stop being a master browser forever.
 723
 724 ******************************************************************/
 725
 726 void process_reset_browser(struct subnet_record *subrec,
 727                                   struct packet_struct *p,const char *buf)
 728 {
 729         struct dgram_packet *dgram = &p->packet.dgram;
 730         int state = CVAL(buf,0);
 731         struct subnet_record *sr;
 732
 733         DEBUG(1,("process_reset_browser: received diagnostic browser reset \
 734 request from %s IP %s state=0x%X\n",
 735                 nmb_namestr(&dgram->source_name), inet_ntoa(p->ip), state));
 736
 737         /* Stop being a local master browser on all our broadcast subnets. */
 738         if (state & 0x1) {
 739                 for (sr = FIRST_SUBNET; sr; sr = NEXT_SUBNET_EXCLUDING_UNICAST(sr)) {
 740                         struct work_record *work;
 741                         for (work = sr->workgrouplist; work; work = work->next) {
 742                                 if (AM_LOCAL_MASTER_BROWSER(work))
 743                                         unbecome_local_master_browser(sr, work, True);
 744                         }
 745                 }
 746         }
 747
 748         /* Discard our browse lists. */
 749         if (state & 0x2) {
 750                 /*
 751                  * Calling expire_workgroups_and_servers with a -1
 752                  * time causes all servers not marked with a PERMANENT_TTL
 753                  * on the workgroup lists to be discarded, and all
 754                  * workgroups with empty server lists to be discarded.
 755                  * This means we keep our own server names and workgroup
 756                  * as these have a PERMANENT_TTL.
 757                  */
 758
 759                 expire_workgroups_and_servers(-1);
 760         }
 761
 762         /* Request to stop browsing altogether. */
 763         if (state & 0x4)
 764                 DEBUG(1,("process_reset_browser: ignoring request to stop being a browser.\n"));
 765 }
 766
 767 /*******************************************************************
 768   Process an announcement request packet.
 769   We don't respond immediately, we just check it's a request for
 770   our workgroup and then set the flag telling the announce code
 771   in nmbd_sendannounce.c:announce_my_server_names that an
 772   announcement is needed soon.
 773 ******************************************************************/
 774
 775 void process_announce_request(struct subnet_record *subrec, struct packet_struct *p, const char *buf)
 776 {
 777         struct dgram_packet *dgram = &p->packet.dgram;
 778         struct work_record *work;
 779         unstring workgroup_name;
 780
 781         pull_ascii_nstring(workgroup_name, sizeof(workgroup_name), dgram->dest_name.name);
 782         DEBUG(3,("process_announce_request: Announce request from %s IP %s to %s.\n",
 783                 nmb_namestr(&dgram->source_name), inet_ntoa(p->ip),
 784                 nmb_namestr(&dgram->dest_name)));
 785
 786         /* We only send announcement requests on our workgroup. */
 787         if(strequal(workgroup_name, lp_workgroup()) == False) {
 788                 DEBUG(7,("process_announce_request: Ignoring announce request for workgroup %s.\n",
 789                         workgroup_name));
 790                 goto done;
 791         }
 792
 793         if((work = find_workgroup_on_subnet(subrec, workgroup_name)) == NULL) {
 794                 DEBUG(0,("process_announce_request: Unable to find workgroup %s on subnet !\n",
 795                         workgroup_name));
 796                 goto done;
 797         }
 798
 799         work->needannounce = True;
 800 done:
 801         return;
 802 }
 803
 804 /*******************************************************************
 805   Process a LanMan announcement request packet.
 806   We don't respond immediately, we just check it's a request for
 807   our workgroup and then set the flag telling that we have found
 808   a LanMan client (DOS or OS/2) and that we will have to start
 809   sending LanMan announcements (unless specifically disabled
 810   through the "lm announce" parameter in smb.conf)
 811 ******************************************************************/
 812
 813 void process_lm_announce_request(struct subnet_record *subrec, struct packet_struct *p, const char *buf, int len)
 814 {
 815         struct dgram_packet *dgram = &p->packet.dgram;
 816         unstring workgroup_name;
 817
 818         pull_ascii_nstring(workgroup_name, sizeof(workgroup_name), dgram->dest_name.name);
 819         DEBUG(3,("process_lm_announce_request: Announce request from %s IP %s to %s.\n",
 820                 nmb_namestr(&dgram->source_name), inet_ntoa(p->ip),
 821                 nmb_namestr(&dgram->dest_name)));
 822
 823         /* We only send announcement requests on our workgroup. */
 824         if(strequal(workgroup_name, lp_workgroup()) == False) {
 825                 DEBUG(7,("process_lm_announce_request: Ignoring announce request for workgroup %s.\n",
 826                         workgroup_name));
 827                 goto done;
 828         }
 829
 830         if(find_workgroup_on_subnet(subrec, workgroup_name) == NULL) {
 831                 DEBUG(0,("process_announce_request: Unable to find workgroup %s on subnet !\n",
 832                         workgroup_name));
 833                 goto done;
 834         }
 835
 836         found_lm_clients = True;
 837
 838 done:
 839         return;
 840 }