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 int DEBUGLEVEL;
  35
  36 extern fstring myworkgroup;
  37 extern char **my_netbios_names;
  38 extern struct in_addr ipzero;
  39
  40 /* This is the broadcast subnets database. */
  41 struct subnet_record *subnetlist = NULL;
  42
  43 /* Extra subnets - keep these separate so enumeration code doesn't
  44    run onto it by mistake. */
  45
  46 struct subnet_record *unicast_subnet = NULL;
  47 struct subnet_record *remote_broadcast_subnet = NULL;
  48 struct subnet_record *wins_server_subnet = NULL;
  49
  50 extern uint16 samba_nb_type; /* Samba's NetBIOS name type. */
  51
  52 /****************************************************************************
  53   Add a subnet into the list.
  54   **************************************************************************/
  55
  56 static void add_subnet(struct subnet_record *subrec)
  57 {
  58         DLIST_ADD(subnetlist, subrec);
  59 }
  60
  61 /* ************************************************************************** **
  62  * Comparison routine for ordering the splay-tree based namelists assoicated
  63  * with each subnet record.
  64  *
  65  *  Input:  Item  - Pointer to the comparison key.
  66  *          Node  - Pointer to a node the splay tree.
  67  *
  68  *  Output: The return value will be <0 , ==0, or >0 depending upon the
  69  *          ordinal relationship of the two keys.
  70  *
  71  * ************************************************************************** **
  72  */
  73 static int namelist_entry_compare( ubi_trItemPtr Item, ubi_trNodePtr Node )
  74   {
  75   struct name_record *NR = (struct name_record *)Node;
  76
  77   if( DEBUGLVL( 10 ) )
  78     {
  79     struct nmb_name *Iname = (struct nmb_name *)Item;
  80
  81     Debug1( "nmbd_subnetdb:namelist_entry_compare()\n" );
  82     Debug1( "%d == memcmp( \"%s\", \"%s\", %d )\n",
  83             memcmp( Item, &(NR->name), sizeof(struct nmb_name) ),
  84             nmb_namestr(Iname), nmb_namestr(&NR->name), (int)sizeof(struct nmb_name) );
  85     }
  86
  87   return( memcmp( Item, &(NR->name), sizeof(struct nmb_name) ) );
  88   } /* namelist_entry_compare */
  89
  90
  91 /****************************************************************************
  92 stop listening on a subnet
  93 we don't free the record as we don't have proper reference counting for it
  94 yet and it may be in use by a response record
  95   ****************************************************************************/
  96 void close_subnet(struct subnet_record *subrec)
  97 {
  98         DLIST_REMOVE(subnetlist, subrec);
  99
 100         if (subrec->dgram_sock != -1) {
 101                 close(subrec->dgram_sock);
 102                 subrec->dgram_sock = -1;
 103         }
 104         if (subrec->nmb_sock != -1) {
 105                 close(subrec->nmb_sock);
 106                 subrec->nmb_sock = -1;
 107         }
 108 }
 109
 110
 111
 112 /****************************************************************************
 113   Create a subnet entry.
 114   ****************************************************************************/
 115
 116 static struct subnet_record *make_subnet(char *name, enum subnet_type type,
 117                                          struct in_addr myip, struct in_addr bcast_ip,
 118                                          struct in_addr mask_ip)
 119 {
 120   struct subnet_record *subrec = NULL;
 121   int nmb_sock, dgram_sock;
 122
 123   /* Check if we are creating a non broadcast subnet - if so don't create
 124      sockets.
 125    */
 126
 127   if(type != NORMAL_SUBNET)
 128   {
 129     nmb_sock = -1;
 130     dgram_sock = -1;
 131   }
 132   else
 133   {
 134     /*
 135      * Attempt to open the sockets on port 137/138 for this interface
 136      * and bind them.
 137      * Fail the subnet creation if this fails.
 138      */
 139
 140     if((nmb_sock = open_socket_in(SOCK_DGRAM, global_nmb_port,0, myip.s_addr,True)) == -1)
 141     {
 142       if( DEBUGLVL( 0 ) )
 143       {
 144         Debug1( "nmbd_subnetdb:make_subnet()\n" );
 145         Debug1( "  Failed to open nmb socket on interface %s ", inet_ntoa(myip) );
 146         Debug1( "for port %d.  ", global_nmb_port );
 147         Debug1( "Error was %s\n", strerror(errno) );
 148       }
 149       return NULL;
 150     }
 151
 152     if((dgram_sock = open_socket_in(SOCK_DGRAM,DGRAM_PORT,3, myip.s_addr,True)) == -1)
 153     {
 154       if( DEBUGLVL( 0 ) )
 155       {
 156         Debug1( "nmbd_subnetdb:make_subnet()\n" );
 157         Debug1( "  Failed to open dgram socket on interface %s ", inet_ntoa(myip) );
 158         Debug1( "for port %d.  ", DGRAM_PORT );
 159         Debug1( "Error was %s\n", strerror(errno) );
 160       }
 161       return NULL;
 162     }
 163
 164     /* Make sure we can broadcast from these sockets. */
 165     set_socket_options(nmb_sock,"SO_BROADCAST");
 166     set_socket_options(dgram_sock,"SO_BROADCAST");
 167
 168   }
 169
 170   subrec = (struct subnet_record *)malloc(sizeof(*subrec));
 171
 172   if (!subrec)
 173   {
 174     DEBUG(0,("make_subnet: malloc fail !\n"));
 175     close(nmb_sock);
 176     close(dgram_sock);
 177     return(NULL);
 178   }
 179
 180   memset( (char *)subrec, '\0', sizeof(*subrec) );
 181   (void)ubi_trInitTree( subrec->namelist,
 182                         namelist_entry_compare,
 183                         ubi_trOVERWRITE );
 184
 185   if((subrec->subnet_name = strdup(name)) == NULL)
 186   {
 187     DEBUG(0,("make_subnet: malloc fail for subnet name !\n"));
 188     close(nmb_sock);
 189     close(dgram_sock);
 190     ZERO_STRUCTP(subrec);
 191     free((char *)subrec);
 192     return(NULL);
 193   }
 194
 195   DEBUG(2, ("making subnet name:%s ", name ));
 196   DEBUG(2, ("Broadcast address:%s ", inet_ntoa(bcast_ip)));
 197   DEBUG(2, ("Subnet mask:%s\n", inet_ntoa(mask_ip)));
 198
 199   subrec->namelist_changed = False;
 200   subrec->work_changed = False;
 201
 202   subrec->bcast_ip = bcast_ip;
 203   subrec->mask_ip  = mask_ip;
 204   subrec->myip = myip;
 205   subrec->type = type;
 206   subrec->nmb_sock = nmb_sock;
 207   subrec->dgram_sock = dgram_sock;
 208
 209   return subrec;
 210 }
 211
 212
 213 /****************************************************************************
 214   Create a normal subnet
 215 **************************************************************************/
 216 struct subnet_record *make_normal_subnet(struct interface *iface)
 217 {
 218         struct subnet_record *subrec;
 219
 220         subrec = make_subnet(inet_ntoa(iface->ip), NORMAL_SUBNET,
 221                              iface->ip, iface->bcast, iface->nmask);
 222         if (subrec) {
 223                 add_subnet(subrec);
 224         }
 225         return subrec;
 226 }
 227
 228
 229 /****************************************************************************
 230   Create subnet entries.
 231 **************************************************************************/
 232
 233 BOOL create_subnets(void)
 234 {
 235   int num_interfaces = iface_count();
 236   int i;
 237   struct in_addr unicast_ip;
 238   extern struct in_addr loopback_ip;
 239
 240   if(num_interfaces == 0)
 241   {
 242     DEBUG(0,("create_subnets: No local interfaces !\n"));
 243     return False;
 244   }
 245
 246   /*
 247    * Create subnets from all the local interfaces and thread them onto
 248    * the linked list.
 249    */
 250
 251   for (i = 0 ; i < num_interfaces; i++)
 252   {
 253     struct interface *iface = get_interface(i);
 254
 255     /*
 256      * We don't want to add a loopback interface, in case
 257      * someone has added 127.0.0.1 for smbd, nmbd needs to
 258      * ignore it here. JRA.
 259      */
 260
 261     if (ip_equal(iface->ip, loopback_ip)) {
 262       DEBUG(2,("create_subnets: Ignoring loopback interface.\n" ));
 263       continue;
 264     }
 265
 266     if (!make_normal_subnet(iface)) return False;
 267   }
 268
 269   /*
 270    * If we have been configured to use a WINS server, then try and
 271    * get the ip address of it here. If we are the WINS server then
 272    * set the unicast subnet address to be the first of our own real
 273    * addresses.
 274    *
 275    * NOTE: I'm not sure of the implications of WINS server failover
 276    *       on this bit of code.  Because of failover, the WINS
 277    *       server address can change.  crh
 278    */
 279
 280   if(*lp_wins_server())
 281   {
 282     struct in_addr real_wins_ip;
 283     real_wins_ip = wins_srv_ip();
 284
 285     if (!zero_ip(real_wins_ip))
 286     {
 287       unicast_ip = real_wins_ip;
 288     }
 289     else
 290     {
 291       /* wins_srv_ip() can return a zero IP if all servers are
 292        * either down or incorrectly entered in smb.conf.  crh
 293        */
 294       DEBUG(0,("No 'live' WINS servers found.  Check 'wins server' parameter.\n"));
 295       return False;
 296     }
 297   }
 298   else if(lp_we_are_a_wins_server())
 299   {
 300     /* Pick the first interface ip address as the WINS server ip. */
 301     unicast_ip = *iface_n_ip(0);
 302   }
 303   else
 304   {
 305     /* We should not be using a WINS server at all. Set the
 306       ip address of the subnet to be zero. */
 307     unicast_ip = ipzero;
 308   }
 309
 310   /*
 311    * Create the unicast and remote broadcast subnets.
 312    * Don't put these onto the linked list.
 313    * The ip address of the unicast subnet is set to be
 314    * the WINS server address, if it exists, or ipzero if not.
 315    */
 316
 317   unicast_subnet = make_subnet( "UNICAST_SUBNET", UNICAST_SUBNET,
 318                                  unicast_ip, unicast_ip, unicast_ip);
 319
 320   remote_broadcast_subnet = make_subnet( "REMOTE_BROADCAST_SUBNET",
 321                                          REMOTE_BROADCAST_SUBNET,
 322                                          ipzero, ipzero, ipzero);
 323
 324   if((unicast_subnet == NULL) || (remote_broadcast_subnet == NULL))
 325     return False;
 326
 327   /*
 328    * If we are WINS server, create the WINS_SERVER_SUBNET - don't put on
 329    * the linked list.
 330    */
 331
 332   if (lp_we_are_a_wins_server())
 333   {
 334     if( (wins_server_subnet = make_subnet( "WINS_SERVER_SUBNET",
 335                                            WINS_SERVER_SUBNET,
 336                                            ipzero, ipzero, ipzero )) == NULL )
 337       return False;
 338   }
 339
 340   return True;
 341 }
 342
 343 /*******************************************************************
 344 Function to tell us if we can use the unicast subnet.
 345 ******************************************************************/
 346
 347 BOOL we_are_a_wins_client(void)
 348 {
 349   static int cache_we_are_a_wins_client = -1;
 350
 351   if(cache_we_are_a_wins_client == -1)
 352     cache_we_are_a_wins_client = (ip_equal(ipzero, unicast_subnet->myip) ?
 353                                   False : True);
 354
 355   return cache_we_are_a_wins_client;
 356 }
 357
 358 /*******************************************************************
 359 Access function used by NEXT_SUBNET_INCLUDING_UNICAST
 360 ******************************************************************/
 361
 362 struct subnet_record *get_next_subnet_maybe_unicast(struct subnet_record *subrec)
 363 {
 364   if(subrec == unicast_subnet)
 365     return NULL;
 366   else if((subrec->next == NULL) && we_are_a_wins_client())
 367     return unicast_subnet;
 368   else
 369     return subrec->next;
 370 }
 371
 372 /*******************************************************************
 373  Access function used by retransmit_or_expire_response_records() in
 374  nmbd_packets.c. Patch from Andrey Alekseyev <fetch@muffin.arcadia.spb.ru>
 375  Needed when we need to enumerate all the broadcast, unicast and
 376  WINS subnets.
 377 ******************************************************************/
 378
 379 struct subnet_record *get_next_subnet_maybe_unicast_or_wins_server(struct subnet_record *subrec)
 380 {
 381   if(subrec == unicast_subnet)
 382   {
 383     if(wins_server_subnet)
 384       return wins_server_subnet;
 385     else
 386       return NULL;
 387   }
 388
 389   if(wins_server_subnet && subrec == wins_server_subnet)
 390     return NULL;
 391
 392   if((subrec->next == NULL) && we_are_a_wins_client())
 393     return unicast_subnet;
 394   else
 395     return subrec->next;
 396 }