source/nmbd/nmbd_subnetdb.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    Revision History:
  24
  25 */
  26
  27 #include "includes.h"
  28 #include "smb.h"
  29
  30 extern int ClientNMB;
  31 extern int ClientDGRAM;
  32 extern int global_nmb_port;
  33
  34 extern fstring myworkgroup;
  35 extern char **my_netbios_names;
  36 extern struct in_addr ipzero;
  37
  38 /* This is the broadcast subnets database. */
  39 struct subnet_record *subnetlist = NULL;
  40
  41 /* Extra subnets - keep these separate so enumeration code doesn't
  42    run onto it by mistake. */
  43
  44 struct subnet_record *unicast_subnet = NULL;
  45 struct subnet_record *remote_broadcast_subnet = NULL;
  46 struct subnet_record *wins_server_subnet = NULL;
  47
  48 extern uint16 samba_nb_type; /* Samba's NetBIOS name type. */
  49
  50 /****************************************************************************
  51   Add a subnet into the list.
  52   **************************************************************************/
  53
  54 static void add_subnet(struct subnet_record *subrec)
  55 {
  56         DLIST_ADD(subnetlist, subrec);
  57 }
  58
  59 /* ************************************************************************** **
  60  * Comparison routine for ordering the splay-tree based namelists assoicated
  61  * with each subnet record.
  62  *
  63  *  Input:  Item  - Pointer to the comparison key.
  64  *          Node  - Pointer to a node the splay tree.
  65  *
  66  *  Output: The return value will be <0 , ==0, or >0 depending upon the
  67  *          ordinal relationship of the two keys.
  68  *
  69  * ************************************************************************** **
  70  */
  71 static int namelist_entry_compare( ubi_trItemPtr Item, ubi_trNodePtr Node )
  72   {
  73   struct name_record *NR = (struct name_record *)Node;
  74
  75   if( DEBUGLVL( 10 ) )
  76     {
  77     struct nmb_name *Iname = (struct nmb_name *)Item;
  78
  79     Debug1( "nmbd_subnetdb:namelist_entry_compare()\n" );
  80     Debug1( "%d == memcmp( \"%s\", \"%s\", %d )\n",
  81             memcmp( Item, &(NR->name), sizeof(struct nmb_name) ),
  82             nmb_namestr(Iname), nmb_namestr(&NR->name), (int)sizeof(struct nmb_name) );
  83     }
  84
  85   return( memcmp( Item, &(NR->name), sizeof(struct nmb_name) ) );
  86   } /* namelist_entry_compare */
  87
  88
  89 /****************************************************************************
  90 stop listening on a subnet
  91 we don't free the record as we don't have proper reference counting for it
  92 yet and it may be in use by a response record
  93   ****************************************************************************/
  94 void close_subnet(struct subnet_record *subrec)
  95 {
  96         DLIST_REMOVE(subnetlist, subrec);
  97
  98         if (subrec->dgram_sock != -1) {
  99                 close(subrec->dgram_sock);
 100                 subrec->dgram_sock = -1;
 101         }
 102         if (subrec->nmb_sock != -1) {
 103                 close(subrec->nmb_sock);
 104                 subrec->nmb_sock = -1;
 105         }
 106 }
 107
 108
 109
 110 /****************************************************************************
 111   Create a subnet entry.
 112   ****************************************************************************/
 113
 114 static struct subnet_record *make_subnet(char *name, enum subnet_type type,
 115                                          struct in_addr myip, struct in_addr bcast_ip,
 116                                          struct in_addr mask_ip)
 117 {
 118   struct subnet_record *subrec = NULL;
 119   int nmb_sock, dgram_sock;
 120
 121   /* Check if we are creating a non broadcast subnet - if so don't create
 122      sockets.
 123    */
 124
 125   if(type != NORMAL_SUBNET)
 126   {
 127     nmb_sock = -1;
 128     dgram_sock = -1;
 129   }
 130   else
 131   {
 132     /*
 133      * Attempt to open the sockets on port 137/138 for this interface
 134      * and bind them.
 135      * Fail the subnet creation if this fails.
 136      */
 137
 138     if((nmb_sock = open_socket_in(SOCK_DGRAM, global_nmb_port,0, myip.s_addr,True)) == -1)
 139     {
 140       if( DEBUGLVL( 0 ) )
 141       {
 142         Debug1( "nmbd_subnetdb:make_subnet()\n" );
 143         Debug1( "  Failed to open nmb socket on interface %s ", inet_ntoa(myip) );
 144         Debug1( "for port %d.  ", global_nmb_port );
 145         Debug1( "Error was %s\n", strerror(errno) );
 146       }
 147       return NULL;
 148     }
 149
 150     if((dgram_sock = open_socket_in(SOCK_DGRAM,DGRAM_PORT,3, myip.s_addr,True)) == -1)
 151     {
 152       if( DEBUGLVL( 0 ) )
 153       {
 154         Debug1( "nmbd_subnetdb:make_subnet()\n" );
 155         Debug1( "  Failed to open dgram socket on interface %s ", inet_ntoa(myip) );
 156         Debug1( "for port %d.  ", DGRAM_PORT );
 157         Debug1( "Error was %s\n", strerror(errno) );
 158       }
 159       return NULL;
 160     }
 161
 162     /* Make sure we can broadcast from these sockets. */
 163     set_socket_options(nmb_sock,"SO_BROADCAST");
 164     set_socket_options(dgram_sock,"SO_BROADCAST");
 165
 166   }
 167
 168   subrec = (struct subnet_record *)malloc(sizeof(*subrec));
 169
 170   if (!subrec)
 171   {
 172     DEBUG(0,("make_subnet: malloc fail !\n"));
 173     close(nmb_sock);
 174     close(dgram_sock);
 175     return(NULL);
 176   }
 177
 178   memset( (char *)subrec, '\0', sizeof(*subrec) );
 179   (void)ubi_trInitTree( subrec->namelist,
 180                         namelist_entry_compare,
 181                         ubi_trOVERWRITE );
 182
 183   if((subrec->subnet_name = strdup(name)) == NULL)
 184   {
 185     DEBUG(0,("make_subnet: malloc fail for subnet name !\n"));
 186     close(nmb_sock);
 187     close(dgram_sock);
 188     ZERO_STRUCTP(subrec);
 189     free((char *)subrec);
 190     return(NULL);
 191   }
 192
 193   DEBUG(2, ("making subnet name:%s ", name ));
 194   DEBUG(2, ("Broadcast address:%s ", inet_ntoa(bcast_ip)));
 195   DEBUG(2, ("Subnet mask:%s\n", inet_ntoa(mask_ip)));
 196
 197   subrec->namelist_changed = False;
 198   subrec->work_changed = False;
 199
 200   subrec->bcast_ip = bcast_ip;
 201   subrec->mask_ip  = mask_ip;
 202   subrec->myip = myip;
 203   subrec->type = type;
 204   subrec->nmb_sock = nmb_sock;
 205   subrec->dgram_sock = dgram_sock;
 206
 207   return subrec;
 208 }
 209
 210
 211 /****************************************************************************
 212   Create a normal subnet
 213 **************************************************************************/
 214 struct subnet_record *make_normal_subnet(struct interface *iface)
 215 {
 216         struct subnet_record *subrec;
 217
 218         subrec = make_subnet(inet_ntoa(iface->ip), NORMAL_SUBNET,
 219                              iface->ip, iface->bcast, iface->nmask);
 220         if (subrec) {
 221                 add_subnet(subrec);
 222         }
 223         return subrec;
 224 }
 225
 226
 227 /****************************************************************************
 228   Create subnet entries.
 229 **************************************************************************/
 230
 231 BOOL create_subnets(void)
 232 {
 233   int num_interfaces = iface_count();
 234   int i;
 235   struct in_addr unicast_ip;
 236   extern struct in_addr loopback_ip;
 237
 238   if(num_interfaces == 0)
 239   {
 240     DEBUG(0,("create_subnets: No local interfaces !\n"));
 241     return False;
 242   }
 243
 244   /*
 245    * Create subnets from all the local interfaces and thread them onto
 246    * the linked list.
 247    */
 248
 249   for (i = 0 ; i < num_interfaces; i++)
 250   {
 251     struct interface *iface = get_interface(i);
 252
 253     /*
 254      * We don't want to add a loopback interface, in case
 255      * someone has added 127.0.0.1 for smbd, nmbd needs to
 256      * ignore it here. JRA.
 257      */
 258
 259     if (ip_equal(iface->ip, loopback_ip)) {
 260       DEBUG(2,("create_subnets: Ignoring loopback interface.\n" ));
 261       continue;
 262     }
 263
 264     if (!make_normal_subnet(iface)) return False;
 265   }
 266
 267   /*
 268    * If we have been configured to use a WINS server, then try and
 269    * get the ip address of it here. If we are the WINS server then
 270    * set the unicast subnet address to be the first of our own real
 271    * addresses.
 272    *
 273    * NOTE: I'm not sure of the implications of WINS server failover
 274    *       on this bit of code.  Because of failover, the WINS
 275    *       server address can change.  crh
 276    */
 277
 278   if(*lp_wins_server())
 279   {
 280     struct in_addr real_wins_ip;
 281     real_wins_ip = wins_srv_ip();
 282
 283     if (!zero_ip(real_wins_ip))
 284     {
 285       unicast_ip = real_wins_ip;
 286     }
 287     else
 288     {
 289       /* wins_srv_ip() can return a zero IP if all servers are
 290        * either down or incorrectly entered in smb.conf.  crh
 291        */
 292       DEBUG(0,("No 'live' WINS servers found.  Check 'wins server' parameter.\n"));
 293       return False;
 294     }
 295   }
 296   else if(lp_we_are_a_wins_server())
 297   {
 298     /* Pick the first interface ip address as the WINS server ip. */
 299     unicast_ip = *iface_n_ip(0);
 300   }
 301   else
 302   {
 303     /* We should not be using a WINS server at all. Set the
 304       ip address of the subnet to be zero. */
 305     unicast_ip = ipzero;
 306   }
 307
 308   /*
 309    * Create the unicast and remote broadcast subnets.
 310    * Don't put these onto the linked list.
 311    * The ip address of the unicast subnet is set to be
 312    * the WINS server address, if it exists, or ipzero if not.
 313    */
 314
 315   unicast_subnet = make_subnet( "UNICAST_SUBNET", UNICAST_SUBNET,
 316                                  unicast_ip, unicast_ip, unicast_ip);
 317
 318   remote_broadcast_subnet = make_subnet( "REMOTE_BROADCAST_SUBNET",
 319                                          REMOTE_BROADCAST_SUBNET,
 320                                          ipzero, ipzero, ipzero);
 321
 322   if((unicast_subnet == NULL) || (remote_broadcast_subnet == NULL))
 323     return False;
 324
 325   /*
 326    * If we are WINS server, create the WINS_SERVER_SUBNET - don't put on
 327    * the linked list.
 328    */
 329
 330   if (lp_we_are_a_wins_server())
 331   {
 332     if( (wins_server_subnet = make_subnet( "WINS_SERVER_SUBNET",
 333                                            WINS_SERVER_SUBNET,
 334                                            ipzero, ipzero, ipzero )) == NULL )
 335       return False;
 336   }
 337
 338   return True;
 339 }
 340
 341 /*******************************************************************
 342 Function to tell us if we can use the unicast subnet.
 343 ******************************************************************/
 344
 345 BOOL we_are_a_wins_client(void)
 346 {
 347   static int cache_we_are_a_wins_client = -1;
 348
 349   if(cache_we_are_a_wins_client == -1)
 350     cache_we_are_a_wins_client = (ip_equal(ipzero, unicast_subnet->myip) ?
 351                                   False : True);
 352
 353   return cache_we_are_a_wins_client;
 354 }
 355
 356 /*******************************************************************
 357 Access function used by NEXT_SUBNET_INCLUDING_UNICAST
 358 ******************************************************************/
 359
 360 struct subnet_record *get_next_subnet_maybe_unicast(struct subnet_record *subrec)
 361 {
 362   if(subrec == unicast_subnet)
 363     return NULL;
 364   else if((subrec->next == NULL) && we_are_a_wins_client())
 365     return unicast_subnet;
 366   else
 367     return subrec->next;
 368 }
 369
 370 /*******************************************************************
 371  Access function used by retransmit_or_expire_response_records() in
 372  nmbd_packets.c. Patch from Andrey Alekseyev <fetch@muffin.arcadia.spb.ru>
 373  Needed when we need to enumerate all the broadcast, unicast and
 374  WINS subnets.
 375 ******************************************************************/
 376
 377 struct subnet_record *get_next_subnet_maybe_unicast_or_wins_server(struct subnet_record *subrec)
 378 {
 379   if(subrec == unicast_subnet)
 380   {
 381     if(wins_server_subnet)
 382       return wins_server_subnet;
 383     else
 384       return NULL;
 385   }
 386
 387   if(wins_server_subnet && subrec == wins_server_subnet)
 388     return NULL;
 389
 390   if((subrec->next == NULL) && we_are_a_wins_client())
 391     return unicast_subnet;
 392   else
 393     return subrec->next;
 394 }