release/src/router/samba3/source/nmbd/nmbd_become_dmb.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 1994-2003
   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 2 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, write to the Free Software
  20    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  21
  22 */
  23
  24 #include "includes.h"
  25
  26 extern struct in_addr allones_ip;
  27
  28 extern uint16 samba_nb_type; /* Samba's NetBIOS type. */
  29
  30 static void become_domain_master_browser_bcast(const char *);
  31
  32 /****************************************************************************
  33   Fail to become a Domain Master Browser on a subnet.
  34   ****************************************************************************/
  35
  36 static void become_domain_master_fail(struct subnet_record *subrec,
  37                                       struct response_record *rrec,
  38                                       struct nmb_name *fail_name)
  39 {
  40         unstring failname;
  41         struct work_record *work;
  42         struct server_record *servrec;
  43
  44         pull_ascii_nstring(failname, sizeof(failname), fail_name->name);
  45         work = find_workgroup_on_subnet(subrec, failname);
  46         if(!work) {
  47                 DEBUG(0,("become_domain_master_fail: Error - cannot find \
  48 workgroup %s on subnet %s\n", failname, subrec->subnet_name));
  49                 return;
  50         }
  51
  52         /* Set the state back to DOMAIN_NONE. */
  53         work->dom_state = DOMAIN_NONE;
  54
  55         if((servrec = find_server_in_workgroup( work, global_myname())) == NULL) {
  56                 DEBUG(0,("become_domain_master_fail: Error - cannot find server %s \
  57 in workgroup %s on subnet %s\n",
  58                         global_myname(), work->work_group, subrec->subnet_name));
  59                 return;
  60         }
  61
  62         /* Update our server status. */
  63         servrec->serv.type &= ~SV_TYPE_DOMAIN_MASTER;
  64
  65         /* Tell the namelist writer to write out a change. */
  66         subrec->work_changed = True;
  67
  68         DEBUG(0,("become_domain_master_fail: Failed to become a domain master browser for \
  69 workgroup %s on subnet %s. Couldn't register name %s.\n",
  70                 work->work_group, subrec->subnet_name, nmb_namestr(fail_name)));
  71 }
  72
  73 /****************************************************************************
  74   Become a Domain Master Browser on a subnet.
  75   ****************************************************************************/
  76
  77 static void become_domain_master_stage2(struct subnet_record *subrec,
  78                                         struct userdata_struct *userdata,
  79                                         struct nmb_name *registered_name,
  80                                         uint16 nb_flags,
  81                                         int ttl, struct in_addr registered_ip)
  82 {
  83         unstring regname;
  84         struct work_record *work;
  85         struct server_record *servrec;
  86
  87         pull_ascii_nstring(regname, sizeof(regname), registered_name->name);
  88         work = find_workgroup_on_subnet( subrec, regname);
  89
  90         if(!work) {
  91                 DEBUG(0,("become_domain_master_stage2: Error - cannot find \
  92 workgroup %s on subnet %s\n", regname, subrec->subnet_name));
  93                 return;
  94         }
  95
  96         if((servrec = find_server_in_workgroup( work, global_myname())) == NULL) {
  97                 DEBUG(0,("become_domain_master_stage2: Error - cannot find server %s \
  98 in workgroup %s on subnet %s\n",
  99                 global_myname(), regname, subrec->subnet_name));
 100                 work->dom_state = DOMAIN_NONE;
 101                 return;
 102         }
 103
 104         /* Set the state in the workgroup structure. */
 105         work->dom_state = DOMAIN_MST; /* Become domain master. */
 106
 107         /* Update our server status. */
 108         servrec->serv.type |= (SV_TYPE_NT|SV_TYPE_DOMAIN_MASTER);
 109
 110         /* Tell the namelist writer to write out a change. */
 111         subrec->work_changed = True;
 112
 113         if( DEBUGLVL( 0 ) ) {
 114                 dbgtext( "Samba server %s is now a domain master browser for "
 115                          "workgroup %s on subnet %s\n",
 116                          global_myname(), work->work_group, subrec->subnet_name );
 117         }
 118
 119         if( subrec == unicast_subnet ) {
 120                 struct nmb_name nmbname;
 121                 struct in_addr my_first_ip;
 122                 struct in_addr *nip;
 123
 124                 /* Put our name and first IP address into the
 125                    workgroup struct as domain master browser. This
 126                    will stop us syncing with ourself if we are also
 127                    a local master browser. */
 128
 129                 make_nmb_name(&nmbname, global_myname(), 0x20);
 130
 131                 work->dmb_name = nmbname;
 132                 /* Pick the first interface ip address as the domain master browser ip. */
 133                 nip = iface_n_ip(0);
 134
 135                 if (!nip) {
 136                         DEBUG(0,("become_domain_master_stage2: Error. iface_n_ip returned NULL\n"));
 137                         return;
 138                 }
 139
 140                 my_first_ip = *nip;
 141
 142                 putip((char *)&work->dmb_addr, &my_first_ip);
 143
 144                 /* We successfully registered by unicast with the
 145                    WINS server.  We now expect to become the domain
 146                    master on the local subnets. If this fails, it's
 147                    probably a 1.9.16p2 to 1.9.16p11 server's fault.
 148
 149                    This is a configuration issue that should be addressed
 150                    by the network administrator - you shouldn't have
 151                    several machines configured as a domain master browser
 152                    for the same WINS scope (except if they are 1.9.17 or
 153                    greater, and you know what you're doing.
 154
 155                    see docs/DOMAIN.txt.
 156
 157                 */
 158                 become_domain_master_browser_bcast(work->work_group);
 159         } else {
 160                 /*
 161                  * Now we are a domain master on a broadcast subnet, we need to add
 162                  * the WORKGROUP<1b> name to the unicast subnet so that we can answer
 163                  * unicast requests sent to this name. This bug wasn't found for a while
 164                  * as it is strange to have a DMB without using WINS. JRA.
 165                  */
 166                 insert_permanent_name_into_unicast(subrec, registered_name, nb_flags);
 167         }
 168 }
 169
 170 /****************************************************************************
 171   Start the name registration process when becoming a Domain Master Browser
 172   on a subnet.
 173 ****************************************************************************/
 174
 175 static void become_domain_master_stage1(struct subnet_record *subrec, const char *wg_name)
 176 {
 177         struct work_record *work;
 178
 179         DEBUG(2,("become_domain_master_stage1: Becoming domain master browser for \
 180 workgroup %s on subnet %s\n", wg_name, subrec->subnet_name));
 181
 182         /* First, find the workgroup on the subnet. */
 183         if((work = find_workgroup_on_subnet( subrec, wg_name )) == NULL) {
 184                 DEBUG(0,("become_domain_master_stage1: Error - unable to find workgroup %s on subnet %s.\n",
 185                         wg_name, subrec->subnet_name));
 186                 return;
 187         }
 188
 189         DEBUG(3,("become_domain_master_stage1: go to first stage: register <1b> name\n"));
 190         work->dom_state = DOMAIN_WAIT;
 191
 192         /* WORKGROUP<1b> is the domain master browser name. */
 193         register_name(subrec, work->work_group,0x1b,samba_nb_type,
 194                         become_domain_master_stage2,
 195                         become_domain_master_fail, NULL);
 196 }
 197
 198 /****************************************************************************
 199   Function called when a query for a WORKGROUP<1b> name succeeds.
 200   This is normally a fail condition as it means there is already
 201   a domain master browser for a workgroup and we were trying to
 202   become one.
 203 ****************************************************************************/
 204
 205 static void become_domain_master_query_success(struct subnet_record *subrec,
 206                         struct userdata_struct *userdata,
 207                         struct nmb_name *nmbname, struct in_addr ip,
 208                         struct res_rec *rrec)
 209 {
 210         unstring name;
 211         pull_ascii_nstring(name, sizeof(name), nmbname->name);
 212
 213         /* If the given ip is not ours, then we can't become a domain
 214                 controler as the name is already registered.
 215         */
 216
 217         /* BUG note. Samba 1.9.16p11 servers seem to return the broadcast
 218                 address or zero ip for this query. Pretend this is ok. */
 219
 220         if(ismyip(ip) || ip_equal(allones_ip, ip) || is_zero_ip(ip)) {
 221                 if( DEBUGLVL( 3 ) ) {
 222                         dbgtext( "become_domain_master_query_success():\n" );
 223                         dbgtext( "Our address (%s) ", inet_ntoa(ip) );
 224                         dbgtext( "returned in query for name %s ", nmb_namestr(nmbname) );
 225                         dbgtext( "(domain master browser name) " );
 226                         dbgtext( "on subnet %s.\n", subrec->subnet_name );
 227                         dbgtext( "Continuing with domain master code.\n" );
 228                 }
 229
 230                 become_domain_master_stage1(subrec, name);
 231         } else {
 232                 if( DEBUGLVL( 0 ) ) {
 233                         dbgtext( "There is already a domain master browser at "
 234                                  "IP %s for workgroup %s registered on subnet %s.\n",
 235                                  inet_ntoa(ip), name, subrec->subnet_name );
 236                 }
 237         }
 238 }
 239
 240 /****************************************************************************
 241   Function called when a query for a WORKGROUP<1b> name fails.
 242   This is normally a success condition as it then allows us to register
 243   our own Domain Master Browser name.
 244   ****************************************************************************/
 245
 246 static void become_domain_master_query_fail(struct subnet_record *subrec,
 247                                     struct response_record *rrec,
 248                                     struct nmb_name *question_name, int fail_code)
 249 {
 250         unstring name;
 251
 252         /* If the query was unicast, and the error is not NAM_ERR (name didn't exist),
 253                 then this is a failure. Otherwise, not finding the name is what we want. */
 254
 255         if((subrec == unicast_subnet) && (fail_code != NAM_ERR)) {
 256                 DEBUG(0,("become_domain_master_query_fail: Error %d returned when \
 257 querying WINS server for name %s.\n",
 258                         fail_code, nmb_namestr(question_name)));
 259                 return;
 260         }
 261
 262         /* Otherwise - not having the name allows us to register it. */
 263         pull_ascii_nstring(name, sizeof(name), question_name->name);
 264         become_domain_master_stage1(subrec, name);
 265 }
 266
 267 /****************************************************************************
 268   Attempt to become a domain master browser on all broadcast subnets.
 269   ****************************************************************************/
 270
 271 static void become_domain_master_browser_bcast(const char *workgroup_name)
 272 {
 273         struct subnet_record *subrec;
 274
 275         for (subrec = FIRST_SUBNET; subrec; subrec = NEXT_SUBNET_EXCLUDING_UNICAST(subrec)) {
 276                 struct work_record *work = find_workgroup_on_subnet(subrec, workgroup_name);
 277
 278                 if (work && (work->dom_state == DOMAIN_NONE)) {
 279                         struct nmb_name nmbname;
 280                         make_nmb_name(&nmbname,workgroup_name,0x1b);
 281
 282                         /*
 283                          * Check for our name on the given broadcast subnet first, only initiate
 284                          * further processing if we cannot find it.
 285                          */
 286
 287                         if (find_name_on_subnet(subrec, &nmbname, FIND_SELF_NAME) == NULL) {
 288                                 if( DEBUGLVL( 1 ) ) {
 289                                         dbgtext( "become_domain_master_browser_bcast:\n" );
 290                                         dbgtext( "Attempting to become domain master browser on " );
 291                                         dbgtext( "workgroup %s on subnet %s\n",
 292                                                 workgroup_name, subrec->subnet_name );
 293                                 }
 294
 295                                 /* Send out a query to establish whether there's a
 296                                    domain controller on the local subnet. If not,
 297                                    we can become a domain controller.
 298                                 */
 299
 300                                 DEBUG(1,("become_domain_master_browser_bcast: querying subnet %s \
 301 for domain master browser on workgroup %s\n", subrec->subnet_name, workgroup_name));
 302
 303                                 query_name(subrec, workgroup_name, nmbname.name_type,
 304                                         become_domain_master_query_success,
 305                                         become_domain_master_query_fail,
 306                                         NULL);
 307                         }
 308                 }
 309         }
 310 }
 311
 312 /****************************************************************************
 313   Attempt to become a domain master browser by registering with WINS.
 314   ****************************************************************************/
 315
 316 static void become_domain_master_browser_wins(const char *workgroup_name)
 317 {
 318         struct work_record *work;
 319
 320         work = find_workgroup_on_subnet(unicast_subnet, workgroup_name);
 321
 322         if (work && (work->dom_state == DOMAIN_NONE)) {
 323                 struct nmb_name nmbname;
 324
 325                 make_nmb_name(&nmbname,workgroup_name,0x1b);
 326
 327                 /*
 328                  * Check for our name on the unicast subnet first, only initiate
 329                  * further processing if we cannot find it.
 330                  */
 331
 332                 if (find_name_on_subnet(unicast_subnet, &nmbname, FIND_SELF_NAME) == NULL) {
 333                         if( DEBUGLVL( 1 ) ) {
 334                                 dbgtext( "become_domain_master_browser_wins:\n" );
 335                                 dbgtext( "Attempting to become domain master browser " );
 336                                 dbgtext( "on workgroup %s, subnet %s.\n",
 337                                         workgroup_name, unicast_subnet->subnet_name );
 338                         }
 339
 340                         /* Send out a query to establish whether there's a
 341                            domain master broswer registered with WINS. If not,
 342                            we can become a domain master browser.
 343                         */
 344
 345                         DEBUG(1,("become_domain_master_browser_wins: querying WINS server from IP %s \
 346 for domain master browser name %s on workgroup %s\n",
 347                                 inet_ntoa(unicast_subnet->myip), nmb_namestr(&nmbname), workgroup_name));
 348
 349                         query_name(unicast_subnet, workgroup_name, nmbname.name_type,
 350                                 become_domain_master_query_success,
 351                                 become_domain_master_query_fail,
 352                                 NULL);
 353                 }
 354         }
 355 }
 356
 357 /****************************************************************************
 358   Add the domain logon server and domain master browser names
 359   if we are set up to do so.
 360   **************************************************************************/
 361
 362 void add_domain_names(time_t t)
 363 {
 364         static time_t lastrun = 0;
 365
 366         if ((lastrun != 0) && (t < lastrun + (CHECK_TIME_ADD_DOM_NAMES * 60)))
 367                 return;
 368
 369         lastrun = t;
 370
 371         /* Do the "internet group" - <1c> names. */
 372         if (lp_domain_logons())
 373                 add_logon_names();
 374
 375         /* Do the domain master names. */
 376         if(lp_domain_master()) {
 377                 if(we_are_a_wins_client()) {
 378                         /* We register the WORKGROUP<1b> name with the WINS
 379                                 server first, and call add_domain_master_bcast()
 380                                 only if this is successful.
 381
 382                                 This results in domain logon services being gracefully provided,
 383                                 as opposed to the aggressive nature of 1.9.16p2 to 1.9.16p11.
 384                                 1.9.16p2 to 1.9.16p11 - due to a bug in namelogon.c,
 385                                 cannot provide domain master / domain logon services.
 386                         */
 387                         become_domain_master_browser_wins(lp_workgroup());
 388                 } else {
 389                         become_domain_master_browser_bcast(lp_workgroup());
 390                 }
 391         }
 392 }