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 = iface_count();
 184         int i;
 185         struct in_addr unicast_ip, ipzero;
 186
 187         if(num_interfaces == 0) {
 188                 DEBUG(0,("create_subnets: No local interfaces !\n"));
 189                 DEBUG(0,("create_subnets: Waiting for an interface to appear ...\n"));
 190                 while (iface_count() == 0) {
 191                         sleep(5);
 192                         load_interfaces();
 193                 }
 194         }
 195
 196         num_interfaces = iface_count();
 197
 198         /*
 199          * Create subnets from all the local interfaces and thread them onto
 200          * the linked list.
 201          */
 202
 203         for (i = 0 ; i < num_interfaces; i++) {
 204                 struct interface *iface = get_interface(i);
 205
 206                 if (!iface) {
 207                         DEBUG(2,("create_subnets: can't get interface %d.\n", i ));
 208                         continue;
 209                 }
 210
 211                 /*
 212                  * We don't want to add a loopback interface, in case
 213                  * someone has added 127.0.0.1 for smbd, nmbd needs to
 214                  * ignore it here. JRA.
 215                  */
 216
 217                 if (ip_equal(iface->ip, loopback_ip)) {
 218                         DEBUG(2,("create_subnets: Ignoring loopback interface.\n" ));
 219                         continue;
 220                 }
 221
 222                 if (!make_normal_subnet(iface))
 223                         return False;
 224         }
 225
 226         if (lp_we_are_a_wins_server()) {
 227                 /* Pick the first interface ip address as the WINS server ip. */
 228                 struct in_addr *nip = iface_n_ip(0);
 229
 230                 if (!nip) {
 231                         return False;
 232                 }
 233
 234                 unicast_ip = *nip;
 235         } else {
 236                 /* note that we do not set the wins server IP here. We just
 237                         set it at zero and let the wins registration code cope
 238                         with getting the IPs right for each packet */
 239                 zero_ip(&unicast_ip);
 240         }
 241
 242         /*
 243          * Create the unicast and remote broadcast subnets.
 244          * Don't put these onto the linked list.
 245          * The ip address of the unicast subnet is set to be
 246          * the WINS server address, if it exists, or ipzero if not.
 247          */
 248
 249         unicast_subnet = make_subnet( "UNICAST_SUBNET", UNICAST_SUBNET,
 250                                 unicast_ip, unicast_ip, unicast_ip);
 251
 252         zero_ip(&ipzero);
 253
 254         remote_broadcast_subnet = make_subnet( "REMOTE_BROADCAST_SUBNET",
 255                                 REMOTE_BROADCAST_SUBNET,
 256                                 ipzero, ipzero, ipzero);
 257
 258         if((unicast_subnet == NULL) || (remote_broadcast_subnet == NULL))
 259                 return False;
 260
 261         /*
 262          * If we are WINS server, create the WINS_SERVER_SUBNET - don't put on
 263          * the linked list.
 264          */
 265
 266         if (lp_we_are_a_wins_server()) {
 267                 if( (wins_server_subnet = make_subnet( "WINS_SERVER_SUBNET",
 268                                                 WINS_SERVER_SUBNET,
 269                                                 ipzero, ipzero, ipzero )) == NULL )
 270                         return False;
 271         }
 272
 273         return True;
 274 }
 275
 276 /*******************************************************************
 277 Function to tell us if we can use the unicast subnet.
 278 ******************************************************************/
 279
 280 BOOL we_are_a_wins_client(void)
 281 {
 282         if (wins_srv_count() > 0) {
 283                 return True;
 284         }
 285
 286         return False;
 287 }
 288
 289 /*******************************************************************
 290 Access function used by NEXT_SUBNET_INCLUDING_UNICAST
 291 ******************************************************************/
 292
 293 struct subnet_record *get_next_subnet_maybe_unicast(struct subnet_record *subrec)
 294 {
 295         if(subrec == unicast_subnet)
 296                 return NULL;
 297         else if((subrec->next == NULL) && we_are_a_wins_client())
 298                 return unicast_subnet;
 299         else
 300                 return subrec->next;
 301 }
 302
 303 /*******************************************************************
 304  Access function used by retransmit_or_expire_response_records() in
 305  nmbd_packets.c. Patch from Andrey Alekseyev <fetch@muffin.arcadia.spb.ru>
 306  Needed when we need to enumerate all the broadcast, unicast and
 307  WINS subnets.
 308 ******************************************************************/
 309
 310 struct subnet_record *get_next_subnet_maybe_unicast_or_wins_server(struct subnet_record *subrec)
 311 {
 312         if(subrec == unicast_subnet) {
 313                 if(wins_server_subnet)
 314                         return wins_server_subnet;
 315                 else
 316                         return NULL;
 317         }
 318
 319         if(wins_server_subnet && subrec == wins_server_subnet)
 320                 return NULL;
 321
 322         if((subrec->next == NULL) && we_are_a_wins_client())
 323                 return unicast_subnet;
 324         else
 325                 return subrec->next;
 326 }