source/nmbd/nmbd_become_dmb.c

   1 /*
   2    Unix SMB/Netbios implementation.
   3    Version 1.9.
   4    NBT netbios routines and daemon - version 2
   5    Copyright (C) Andrew Tridgell 1994-1998
   6    Copyright (C) Luke Kenneth Casson Leighton 1994-1998
   7    Copyright (C) Jeremy Allison 1994-1998
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 2 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program; if not, write to the Free Software
  21    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  22
  23 */
  24
  25 #include "includes.h"
  26
  27 extern pstring global_myname;
  28 extern fstring global_myworkgroup;
  29 extern char **my_netbios_names;
  30 extern struct in_addr allones_ip;
  31
  32 extern uint16 samba_nb_type; /* Samba's NetBIOS type. */
  33
  34 static void become_domain_master_browser_bcast(char *);
  35
  36 /****************************************************************************
  37   Fail to become a Domain Master Browser on a subnet.
  38   ****************************************************************************/
  39
  40 static void become_domain_master_fail(struct subnet_record *subrec,
  41                                       struct response_record *rrec,
  42                                       struct nmb_name *fail_name)
  43 {
  44   struct work_record *work = find_workgroup_on_subnet(subrec, fail_name->name);
  45   struct server_record *servrec;
  46
  47   if(!work)
  48   {
  49     DEBUG(0,("become_domain_master_fail: Error - cannot find \
  50 workgroup %s on subnet %s\n", fail_name->name, subrec->subnet_name));
  51     return;
  52   }
  53
  54   /* Set the state back to DOMAIN_NONE. */
  55   work->dom_state = DOMAIN_NONE;
  56
  57   if((servrec = find_server_in_workgroup( work, global_myname)) == NULL)
  58   {
  59     DEBUG(0,("become_domain_master_fail: Error - cannot find server %s \
  60 in workgroup %s on subnet %s\n",
  61        global_myname, work->work_group, subrec->subnet_name));
  62     return;
  63   }
  64
  65   /* Update our server status. */
  66   servrec->serv.type &= ~SV_TYPE_DOMAIN_MASTER;
  67
  68   /* Tell the namelist writer to write out a change. */
  69   subrec->work_changed = True;
  70
  71   DEBUG(0,("become_domain_master_fail: Failed to become a domain master browser for \
  72 workgroup %s on subnet %s. Couldn't register name %s.\n",
  73        work->work_group, subrec->subnet_name, nmb_namestr(fail_name)));
  74 }
  75
  76 /****************************************************************************
  77   Become a Domain Master Browser on a subnet.
  78   ****************************************************************************/
  79
  80 static void become_domain_master_stage2(struct subnet_record *subrec,
  81                                         struct userdata_struct *userdata,
  82                                         struct nmb_name *registered_name,
  83                                         uint16 nb_flags,
  84                                         int ttl, struct in_addr registered_ip)
  85 {
  86   struct work_record *work = find_workgroup_on_subnet( subrec, registered_name->name);
  87   struct server_record *servrec;
  88
  89   if(!work)
  90   {
  91     DEBUG(0,("become_domain_master_stage2: Error - cannot find \
  92 workgroup %s on subnet %s\n", registered_name->name, subrec->subnet_name));
  93     return;
  94   }
  95
  96   if((servrec = find_server_in_workgroup( work, global_myname)) == NULL)
  97   {
  98     DEBUG(0,("become_domain_master_stage2: Error - cannot find server %s \
  99 in workgroup %s on subnet %s\n",
 100        global_myname, registered_name->name, subrec->subnet_name));
 101     work->dom_state = DOMAIN_NONE;
 102     return;
 103   }
 104
 105   /* Set the state in the workgroup structure. */
 106   work->dom_state = DOMAIN_MST; /* Become domain master. */
 107
 108   /* Update our server status. */
 109   servrec->serv.type |= (SV_TYPE_NT|SV_TYPE_DOMAIN_MASTER);
 110
 111   /* Tell the namelist writer to write out a change. */
 112   subrec->work_changed = True;
 113
 114   if( DEBUGLVL( 0 ) )
 115     {
 116     dbgtext( "*****\n\nSamba server %s ", global_myname );
 117     dbgtext( "is now a domain master browser for " );
 118     dbgtext( "workgroup %s ", work->work_group );
 119     dbgtext( "on subnet %s\n\n*****\n", subrec->subnet_name );
 120     }
 121
 122   if( subrec == unicast_subnet )
 123   {
 124     struct nmb_name nmbname;
 125     struct in_addr my_first_ip;
 126
 127     /* Put our name and first IP address into the
 128        workgroup struct as domain master browser. This
 129        will stop us syncing with ourself if we are also
 130        a local master browser. */
 131
 132     make_nmb_name(&nmbname, global_myname, 0x20);
 133
 134     work->dmb_name = nmbname;
 135     /* Pick the first interface ip address as the domain master browser ip. */
 136     my_first_ip = *iface_n_ip(0);
 137
 138     putip((char *)&work->dmb_addr, &my_first_ip);
 139
 140     /* We successfully registered by unicast with the
 141        WINS server.  We now expect to become the domain
 142        master on the local subnets. If this fails, it's
 143        probably a 1.9.16p2 to 1.9.16p11 server's fault.
 144
 145        This is a configuration issue that should be addressed
 146        by the network administrator - you shouldn't have
 147        several machines configured as a domain master browser
 148        for the same WINS scope (except if they are 1.9.17 or
 149        greater, and you know what you're doing.
 150
 151        see docs/DOMAIN.txt.
 152
 153      */
 154     become_domain_master_browser_bcast(work->work_group);
 155   }
 156   else
 157   {
 158     /*
 159      * Now we are a domain master on a broadcast subnet, we need to add
 160      * the WORKGROUP<1b> name to the unicast subnet so that we can answer
 161      * unicast requests sent to this name. This bug wasn't found for a while
 162      * as it is strange to have a DMB without using WINS. JRA.
 163      */
 164     insert_permanent_name_into_unicast(subrec, registered_name, nb_flags);
 165   }
 166 }
 167
 168 /****************************************************************************
 169   Start the name registration process when becoming a Domain Master Browser
 170   on a subnet.
 171   ****************************************************************************/
 172
 173 static void become_domain_master_stage1(struct subnet_record *subrec, char *wg_name)
 174 {
 175   struct work_record *work;
 176
 177   DEBUG(2,("become_domain_master_stage1: Becoming domain master browser for \
 178 workgroup %s on subnet %s\n", wg_name, subrec->subnet_name));
 179
 180   /* First, find the workgroup on the subnet. */
 181   if((work = find_workgroup_on_subnet( subrec, wg_name )) == NULL)
 182   {
 183     DEBUG(0,("become_domain_master_stage1: Error - unable to find workgroup %s on subnet %s.\n",
 184           wg_name, subrec->subnet_name));
 185     return;
 186   }
 187
 188   DEBUG(3,("become_domain_master_stage1: go to first stage: register <1b> name\n"));
 189   work->dom_state = DOMAIN_WAIT;
 190
 191   /* WORKGROUP<1b> is the domain master browser name. */
 192   register_name(subrec, work->work_group,0x1b,samba_nb_type,
 193                 become_domain_master_stage2,
 194                 become_domain_master_fail, NULL);
 195 }
 196
 197 /****************************************************************************
 198   Function called when a query for a WORKGROUP<1b> name succeeds.
 199   This is normally a fail condition as it means there is already
 200   a domain master browser for a workgroup and we were trying to
 201   become one.
 202 ****************************************************************************/
 203
 204 static void become_domain_master_query_success(struct subnet_record *subrec,
 205                         struct userdata_struct *userdata,
 206                         struct nmb_name *nmbname, struct in_addr ip,
 207                         struct res_rec *rrec)
 208 {
 209   /* If the given ip is not ours, then we can't become a domain
 210      controler as the name is already registered.
 211    */
 212
 213  /* BUG note. Samba 1.9.16p11 servers seem to return the broadcast
 214     address or zero ip for this query. Pretend this is ok. */
 215
 216   if(ismyip(ip) || ip_equal(allones_ip, ip) || is_zero_ip(ip))
 217   {
 218     if( DEBUGLVL( 3 ) )
 219     {
 220       dbgtext( "become_domain_master_query_success():\n" );
 221       dbgtext( "Our address (%s) ", inet_ntoa(ip) );
 222       dbgtext( "returned in query for name %s ", nmb_namestr(nmbname) );
 223       dbgtext( "(domain master browser name) " );
 224       dbgtext( "on subnet %s.\n", subrec->subnet_name );
 225       dbgtext( "Continuing with domain master code.\n" );
 226     }
 227
 228     become_domain_master_stage1(subrec, nmbname->name);
 229   }
 230   else
 231   {
 232     if( DEBUGLVL( 0 ) )
 233     {
 234       dbgtext( "become_domain_master_query_success:\n" );
 235       dbgtext( "There is already a domain master browser at " );
 236       dbgtext( "IP %s for workgroup %s ", inet_ntoa(ip), nmbname->name );
 237       dbgtext( "registered on subnet %s.\n", subrec->subnet_name );
 238     }
 239     become_domain_master_stage1(subrec, nmbname->name);
 240   }
 241 }
 242
 243 /****************************************************************************
 244   Function called when a query for a WORKGROUP<1b> name fails.
 245   This is normally a success condition as it then allows us to register
 246   our own Domain Master Browser name.
 247   ****************************************************************************/
 248
 249 static void become_domain_master_query_fail(struct subnet_record *subrec,
 250                                     struct response_record *rrec,
 251                                     struct nmb_name *question_name, int fail_code)
 252 {
 253   /* If the query was unicast, and the error is not NAM_ERR (name didn't exist),
 254      then this is a failure. Otherwise, not finding the name is what we want. */
 255   if((subrec == unicast_subnet) && (fail_code != NAM_ERR))
 256   {
 257     DEBUG(0,("become_domain_master_query_fail: Error %d returned when \
 258 querying WINS server for name %s.\n",
 259                   fail_code, nmb_namestr(question_name)));
 260     return;
 261   }
 262
 263   /* Otherwise - not having the name allows us to register it. */
 264   become_domain_master_stage1(subrec, question_name->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(char *workgroup_name)
 272 {
 273   struct subnet_record *subrec;
 274
 275   for (subrec = FIRST_SUBNET; subrec; subrec = NEXT_SUBNET_EXCLUDING_UNICAST(subrec))
 276   {
 277     struct work_record *work = find_workgroup_on_subnet(subrec, workgroup_name);
 278
 279     if (work && (work->dom_state == DOMAIN_NONE))
 280     {
 281       struct nmb_name nmbname;
 282       make_nmb_name(&nmbname,workgroup_name,0x1b);
 283
 284       /*
 285        * Check for our name on the given broadcast subnet first, only initiate
 286        * further processing if we cannot find it.
 287        */
 288
 289       if (find_name_on_subnet(subrec, &nmbname, FIND_SELF_NAME) == NULL)
 290       {
 291         if( DEBUGLVL( 0 ) )
 292           {
 293           dbgtext( "become_domain_master_browser_bcast:\n" );
 294           dbgtext( "Attempting to become domain master browser on " );
 295           dbgtext( "workgroup %s on subnet %s\n",
 296                     workgroup_name, subrec->subnet_name );
 297           }
 298
 299         /* Send out a query to establish whether there's a
 300            domain controller on the local subnet. If not,
 301            we can become a domain controller.
 302          */
 303
 304         DEBUG(0,("become_domain_master_browser_bcast: querying subnet %s \
 305 for domain master browser on workgroup %s\n", subrec->subnet_name, workgroup_name));
 306
 307         query_name(subrec, nmbname.name, nmbname.name_type,
 308                    become_domain_master_query_success,
 309                    become_domain_master_query_fail,
 310                    NULL);
 311       }
 312     }
 313   }
 314 }
 315
 316 /****************************************************************************
 317   Attempt to become a domain master browser by registering with WINS.
 318   ****************************************************************************/
 319
 320 static void become_domain_master_browser_wins(char *workgroup_name)
 321 {
 322   struct work_record *work;
 323
 324   work = find_workgroup_on_subnet(unicast_subnet, workgroup_name);
 325
 326   if (work && (work->dom_state == DOMAIN_NONE))
 327   {
 328     struct nmb_name nmbname;
 329
 330     make_nmb_name(&nmbname,workgroup_name,0x1b);
 331
 332     /*
 333      * Check for our name on the unicast subnet first, only initiate
 334      * further processing if we cannot find it.
 335      */
 336
 337     if (find_name_on_subnet(unicast_subnet, &nmbname, FIND_SELF_NAME) == NULL)
 338     {
 339       if( DEBUGLVL( 0 ) )
 340         {
 341         dbgtext( "become_domain_master_browser_wins:\n" );
 342         dbgtext( "Attempting to become domain master browser " );
 343         dbgtext( "on workgroup %s, subnet %s.\n",
 344                   workgroup_name, unicast_subnet->subnet_name );
 345         }
 346
 347       /* Send out a query to establish whether there's a
 348          domain master broswer registered with WINS. If not,
 349          we can become a domain master browser.
 350        */
 351
 352       DEBUG(0,("become_domain_master_browser_wins: querying WINS server at IP %s \
 353 for domain master browser name %s on workgroup %s\n",
 354          inet_ntoa(unicast_subnet->myip), nmb_namestr(&nmbname), workgroup_name));
 355
 356       query_name(unicast_subnet, nmbname.name, nmbname.name_type,
 357                    become_domain_master_query_success,
 358                    become_domain_master_query_fail,
 359                    NULL);
 360     }
 361   }
 362 }
 363
 364 /****************************************************************************
 365   Add the domain logon server and domain master browser names
 366   if we are set up to do so.
 367   **************************************************************************/
 368
 369 void add_domain_names(time_t t)
 370 {
 371   static time_t lastrun = 0;
 372
 373   if ((lastrun != 0) && (t < lastrun + (CHECK_TIME_ADD_DOM_NAMES * 60)))
 374     return;
 375
 376   lastrun = t;
 377
 378   /* Do the "internet group" - <1c> names. */
 379   if (lp_domain_logons())
 380     add_logon_names();
 381
 382   /* Do the domain master names. */
 383   if(lp_domain_master())
 384   {
 385     if(we_are_a_wins_client())
 386     {
 387       /* We register the WORKGROUP<1b> name with the WINS
 388          server first, and call add_domain_master_bcast()
 389          only if this is successful.
 390
 391          This results in domain logon services being gracefully provided,
 392          as opposed to the aggressive nature of 1.9.16p2 to 1.9.16p11.
 393          1.9.16p2 to 1.9.16p11 - due to a bug in namelogon.c,
 394          cannot provide domain master / domain logon services.
 395        */
 396       become_domain_master_browser_wins(global_myworkgroup);
 397     }
 398     else
 399       become_domain_master_browser_bcast(global_myworkgroup);
 400   }
 401 }