release/src/router/samba3/source/nmbd/nmbd_subnetdb.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 1994-1998
   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    Revision History:
  23
  24 */
  25
  26 #include "includes.h"
  27
  28 extern struct in_addr loopback_ip;
  29 extern int global_nmb_port;
  30
  31 /* This is the broadcast subnets database. */
  32 struct subnet_record *subnetlist = NULL;
  33
  34 /* Extra subnets - keep these separate so enumeration code doesn't
  35    run onto it by mistake. */
  36
  37 struct subnet_record *unicast_subnet = NULL;
  38 struct subnet_record *remote_broadcast_subnet = NULL;
  39 struct subnet_record *wins_server_subnet = NULL;
  40
  41 extern uint16 samba_nb_type; /* Samba's NetBIOS name type. */
  42
  43 /****************************************************************************
  44   Add a subnet into the list.
  45   **************************************************************************/
  46
  47 static void add_subnet(struct subnet_record *subrec)
  48 {
  49         DLIST_ADD(subnetlist, subrec);
  50 }
  51
  52 /****************************************************************************
  53 stop listening on a subnet
  54 we don't free the record as we don't have proper reference counting for it
  55 yet and it may be in use by a response record
  56   ****************************************************************************/
  57
  58 void close_subnet(struct subnet_record *subrec)
  59 {
  60         if (subrec->dgram_sock != -1) {
  61                 close(subrec->dgram_sock);
  62                 subrec->dgram_sock = -1;
  63         }
  64         if (subrec->nmb_sock != -1) {
  65                 close(subrec->nmb_sock);
  66                 subrec->nmb_sock = -1;
  67         }
  68
  69         DLIST_REMOVE(subnetlist, subrec);
  70 }
  71
  72 /****************************************************************************
  73   Create a subnet entry.
  74   ****************************************************************************/
  75
  76 static struct subnet_record *make_subnet(const char *name, enum subnet_type type,
  77                                          struct in_addr myip, struct in_addr bcast_ip,
  78                                          struct in_addr mask_ip)
  79 {
  80         struct subnet_record *subrec = NULL;
  81         int nmb_sock, dgram_sock;
  82
  83         /* Check if we are creating a non broadcast subnet - if so don't create
  84                 sockets.  */
  85
  86         if(type != NORMAL_SUBNET) {
  87                 nmb_sock = -1;
  88                 dgram_sock = -1;
  89         } else {
  90                 /*
  91                  * Attempt to open the sockets on port 137/138 for this interface
  92                  * and bind them.
  93                  * Fail the subnet creation if this fails.
  94                  */
  95
  96                 if((nmb_sock = open_socket_in(SOCK_DGRAM, global_nmb_port,0, myip.s_addr,True)) == -1) {
  97                         if( DEBUGLVL( 0 ) ) {
  98                                 Debug1( "nmbd_subnetdb:make_subnet()\n" );
  99                                 Debug1( "  Failed to open nmb socket on interface %s ", inet_ntoa(myip) );
 100                                 Debug1( "for port %d.  ", global_nmb_port );
 101                                 Debug1( "Error was %s\n", strerror(errno) );
 102                         }
 103                         return NULL;
 104                 }
 105
 106                 if((dgram_sock = open_socket_in(SOCK_DGRAM,DGRAM_PORT,3, myip.s_addr,True)) == -1) {
 107                         if( DEBUGLVL( 0 ) ) {
 108                                 Debug1( "nmbd_subnetdb:make_subnet()\n" );
 109                                 Debug1( "  Failed to open dgram socket on interface %s ", inet_ntoa(myip) );
 110                                 Debug1( "for port %d.  ", DGRAM_PORT );
 111                                 Debug1( "Error was %s\n", strerror(errno) );
 112                         }
 113                         return NULL;
 114                 }
 115
 116                 /* Make sure we can broadcast from these sockets. */
 117                 set_socket_options(nmb_sock,"SO_BROADCAST");
 118                 set_socket_options(dgram_sock,"SO_BROADCAST");
 119
 120                 /* Set them non-blocking. */
 121                 set_blocking(nmb_sock, False);
 122                 set_blocking(dgram_sock, False);
 123         }
 124
 125         subrec = SMB_MALLOC_P(struct subnet_record);
 126         if (!subrec) {
 127                 DEBUG(0,("make_subnet: malloc fail !\n"));
 128                 close(nmb_sock);
 129                 close(dgram_sock);
 130                 return(NULL);
 131         }
 132
 133         ZERO_STRUCTP(subrec);
 134
 135         if((subrec->subnet_name = SMB_STRDUP(name)) == NULL) {
 136                 DEBUG(0,("make_subnet: malloc fail for subnet name !\n"));
 137                 close(nmb_sock);
 138                 close(dgram_sock);
 139                 ZERO_STRUCTP(subrec);
 140                 SAFE_FREE(subrec);
 141                 return(NULL);
 142         }
 143
 144         DEBUG(2, ("making subnet name:%s ", name ));
 145         DEBUG(2, ("Broadcast address:%s ", inet_ntoa(bcast_ip)));
 146         DEBUG(2, ("Subnet mask:%s\n", inet_ntoa(mask_ip)));
 147
 148         subrec->namelist_changed = False;
 149         subrec->work_changed = False;
 150
 151         subrec->bcast_ip = bcast_ip;
 152         subrec->mask_ip  = mask_ip;
 153         subrec->myip = myip;
 154         subrec->type = type;
 155         subrec->nmb_sock = nmb_sock;
 156         subrec->dgram_sock = dgram_sock;
 157
 158         return subrec;
 159 }
 160
 161 /****************************************************************************
 162   Create a normal subnet
 163 **************************************************************************/
 164
 165 struct subnet_record *make_normal_subnet(struct interface *iface)
 166 {
 167         struct subnet_record *subrec;
 168
 169         subrec = make_subnet(inet_ntoa(iface->ip), NORMAL_SUBNET,
 170                              iface->ip, iface->bcast, iface->nmask);
 171         if (subrec) {
 172                 add_subnet(subrec);
 173         }
 174         return subrec;
 175 }
 176
 177 /****************************************************************************
 178   Create subnet entries.
 179 **************************************************************************/
 180
 181 BOOL create_subnets(void)
 182 {
 183         int num_interfaces;
 184         int i;
 185         struct in_addr unicast_ip, ipzero;
 186
 187   try_interfaces_again:
 188
 189         if (iface_count_nl() == 0) {
 190                 DEBUG(0,("create_subnets: No non-loopback local interfaces !\n"));
 191                 DEBUG(0,("create_subnets: Waiting for an interface to appear ...\n"));
 192         }
 193
 194         while (iface_count_nl() == 0) {
 195                 void (*saved_handler)(int);
 196
 197                 /*
 198                  * Whilst we're waiting for an interface, allow SIGTERM to
 199                  * cause us to exit.
 200                  */
 201
 202                 saved_handler = CatchSignal( SIGTERM, SIGNAL_CAST SIG_DFL );
 203
 204                 sleep(5);
 205                 load_interfaces();
 206
 207                 /*
 208                  * We got an interface, restore our normal term handler.
 209                  */
 210
 211                 CatchSignal( SIGTERM, SIGNAL_CAST saved_handler );
 212         }
 213
 214         num_interfaces = iface_count();
 215
 216         /*
 217          * Create subnets from all the local interfaces and thread them onto
 218          * the linked list.
 219          */
 220
 221         for (i = 0 ; i < num_interfaces; i++) {
 222                 struct interface *iface = get_interface(i);
 223
 224                 if (!iface) {
 225                         DEBUG(2,("create_subnets: can't get interface %d.\n", i ));
 226                         continue;
 227                 }
 228
 229                 /*
 230                  * We don't want to add a loopback interface, in case
 231                  * someone has added 127.0.0.1 for smbd, nmbd needs to
 232                  * ignore it here. JRA.
 233                  */
 234
 235                 if (ip_equal(iface->ip, loopback_ip)) {
 236                         DEBUG(2,("create_subnets: Ignoring loopback interface.\n" ));
 237                         continue;
 238                 }
 239
 240                 if (!make_normal_subnet(iface))
 241                         return False;
 242         }
 243
 244         /* We must have at least one subnet. */
 245         if (subnetlist == NULL) {
 246                 void (*saved_handler)(int);
 247
 248                 DEBUG(0,("create_subnets: Unable to create any subnet from "
 249                                 "given interfaces. Is your interface line in "
 250                                 "smb.conf correct ?\n"));
 251
 252                 saved_handler = CatchSignal( SIGTERM, SIGNAL_CAST SIG_DFL );
 253
 254                 sleep(5);
 255                 load_interfaces();
 256
 257                 CatchSignal( SIGTERM, SIGNAL_CAST saved_handler );
 258                 goto try_interfaces_again;
 259         }
 260
 261         if (lp_we_are_a_wins_server()) {
 262                 /* Pick the first interface ip address as the WINS server ip. */
 263                 struct in_addr *nip = iface_n_ip(0);
 264
 265                 if (!nip) {
 266                         return False;
 267                 }
 268
 269                 unicast_ip = *nip;
 270         } else {
 271                 /* note that we do not set the wins server IP here. We just
 272                         set it at zero and let the wins registration code cope
 273                         with getting the IPs right for each packet */
 274                 zero_ip(&unicast_ip);
 275         }
 276
 277         /*
 278          * Create the unicast and remote broadcast subnets.
 279          * Don't put these onto the linked list.
 280          * The ip address of the unicast subnet is set to be
 281          * the WINS server address, if it exists, or ipzero if not.
 282          */
 283
 284         unicast_subnet = make_subnet( "UNICAST_SUBNET", UNICAST_SUBNET,
 285                                 unicast_ip, unicast_ip, unicast_ip);
 286
 287         zero_ip(&ipzero);
 288
 289         remote_broadcast_subnet = make_subnet( "REMOTE_BROADCAST_SUBNET",
 290                                 REMOTE_BROADCAST_SUBNET,
 291                                 ipzero, ipzero, ipzero);
 292
 293         if((unicast_subnet == NULL) || (remote_broadcast_subnet == NULL))
 294                 return False;
 295
 296         /*
 297          * If we are WINS server, create the WINS_SERVER_SUBNET - don't put on
 298          * the linked list.
 299          */
 300
 301         if (lp_we_are_a_wins_server()) {
 302                 if( (wins_server_subnet = make_subnet( "WINS_SERVER_SUBNET",
 303                                                 WINS_SERVER_SUBNET,
 304                                                 ipzero, ipzero, ipzero )) == NULL )
 305                         return False;
 306         }
 307
 308         return True;
 309 }
 310
 311 /*******************************************************************
 312 Function to tell us if we can use the unicast subnet.
 313 ******************************************************************/
 314
 315 BOOL we_are_a_wins_client(void)
 316 {
 317         if (wins_srv_count() > 0) {
 318                 return True;
 319         }
 320
 321         return False;
 322 }
 323
 324 /*******************************************************************
 325 Access function used by NEXT_SUBNET_INCLUDING_UNICAST
 326 ******************************************************************/
 327
 328 struct subnet_record *get_next_subnet_maybe_unicast(struct subnet_record *subrec)
 329 {
 330         if(subrec == unicast_subnet)
 331                 return NULL;
 332         else if((subrec->next == NULL) && we_are_a_wins_client())
 333                 return unicast_subnet;
 334         else
 335                 return subrec->next;
 336 }
 337
 338 /*******************************************************************
 339  Access function used by retransmit_or_expire_response_records() in
 340  nmbd_packets.c. Patch from Andrey Alekseyev <fetch@muffin.arcadia.spb.ru>
 341  Needed when we need to enumerate all the broadcast, unicast and
 342  WINS subnets.
 343 ******************************************************************/
 344
 345 struct subnet_record *get_next_subnet_maybe_unicast_or_wins_server(struct subnet_record *subrec)
 346 {
 347         if(subrec == unicast_subnet) {
 348                 if(wins_server_subnet)
 349                         return wins_server_subnet;
 350                 else
 351                         return NULL;
 352         }
 353
 354         if(wins_server_subnet && subrec == wins_server_subnet)
 355                 return NULL;
 356
 357         if((subrec->next == NULL) && we_are_a_wins_client())
 358                 return unicast_subnet;
 359         else
 360                 return subrec->next;
 361 }