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