source/nameresp.c

   1 /*
   2    Unix SMB/Netbios implementation.
   3    Version 1.9.
   4    NBT netbios library routines
   5    Copyright (C) Andrew Tridgell 1994-1996
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 2 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program; if not, write to the Free Software
  19    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20
  21    Module name: nameresp.c
  22
  23 */
  24
  25 #include "includes.h"
  26
  27 extern int ClientNMB;
  28 extern int ClientDGRAM;
  29
  30 extern struct subnet_record *subnetlist;
  31
  32 extern int DEBUGLEVEL;
  33
  34 extern pstring scope;
  35 extern struct in_addr ipzero;
  36 extern struct in_addr wins_ip;
  37
  38
  39 /***************************************************************************
  40   deals with an entry before it dies
  41   **************************************************************************/
  42 static void dead_netbios_entry(struct subnet_record *d,
  43                                 struct response_record *n)
  44 {
  45   DEBUG(3,("Removing dead netbios entry for %s %s (num_msgs=%d)\n",
  46            inet_ntoa(n->send_ip), namestr(&n->name), n->num_msgs));
  47
  48   debug_state_type(n->state);
  49
  50   switch (n->state)
  51   {
  52     case NAME_QUERY_CONFIRM:
  53     {
  54       if (!lp_wins_support()) return; /* only if we're a WINS server */
  55
  56       if (n->num_msgs == 0)
  57         {
  58           /* oops. name query had no response. check that the name is
  59              unique and then remove it from our WINS database */
  60
  61           /* IMPORTANT: see query_refresh_names() */
  62
  63           if ((!NAME_GROUP(n->nb_flags)))
  64             {
  65               struct subnet_record *d1 = find_subnet(wins_ip);
  66               if (d1)
  67                 {
  68                   /* remove the name that had been registered with us,
  69                      and we're now getting no response when challenging.
  70                      see rfc1001.txt 15.5.2
  71                      */
  72                   remove_netbios_name(d1, n->name.name, n->name.name_type,
  73                                       REGISTER, n->send_ip);
  74                 }
  75             }
  76         }
  77       break;
  78     }
  79
  80   case NAME_QUERY_MST_CHK:
  81     {
  82       /* if no response received, the master browser must have gone
  83          down on that subnet, without telling anyone. */
  84
  85       /* IMPORTANT: see response_netbios_packet() */
  86
  87       if (n->num_msgs == 0)
  88         browser_gone(n->name.name, n->send_ip);
  89       break;
  90     }
  91
  92   case NAME_RELEASE:
  93     {
  94       /* if no response received, it must be OK for us to release the
  95          name. nobody objected (including a potentially dead or deaf
  96          WINS server) */
  97
  98       /* IMPORTANT: see response_name_release() */
  99
 100       if (ismyip(n->send_ip))
 101         {
 102           name_unregister_work(d,n->name.name,n->name.name_type);
 103         }
 104       if (!n->bcast && n->num_msgs == 0)
 105         {
 106           DEBUG(0,("WINS server did not respond to name release!\n"));
 107           /* XXXX whoops. we have problems. must deal with this */
 108         }
 109       break;
 110     }
 111
 112   case NAME_REGISTER_CHALLENGE:
 113     {
 114       /* name challenge: no reply. we can reply to the person that
 115          wanted the unique name and tell them that they can have it
 116          */
 117
 118       add_name_respond(d,n->fd,d->myip, n->response_id ,&n->name,
 119                        n->nb_flags, GET_TTL(0),
 120                        n->reply_to_ip, False, n->reply_to_ip);
 121
 122       if (!n->bcast && n->num_msgs == 0)
 123         {
 124           DEBUG(1,("WINS server did not respond to name registration!\n"));
 125           /* XXXX whoops. we have problems. must deal with this */
 126         }
 127       break;
 128     }
 129
 130   case NAME_REGISTER:
 131     {
 132       /* if no response received, and we are using a broadcast registration
 133          method, it must be OK for us to register the name: nobody objected
 134          on that subnet. if we are using a WINS server, then the WINS
 135          server must be dead or deaf.
 136          */
 137       if (n->num_msgs == 0)
 138         {
 139           if (n->bcast)
 140             {
 141               /* broadcast method: implicit acceptance of the name registration
 142                  by not receiving any objections. */
 143
 144               /* IMPORTANT: see response_name_reg() */
 145
 146               name_register_work(d,n->name.name,n->name.name_type,
 147                                  n->nb_flags, n->ttl, n->reply_to_ip, n->bcast);
 148             }
 149           else
 150             {
 151               /* received no response. rfc1001.txt states that after retrying,
 152                  we should assume the WINS server is dead, and fall back to
 153                  broadcasting (see bits about M nodes: can't find any right
 154                  now) */
 155
 156               DEBUG(1,("WINS server did not respond to name registration!\n"));
 157               /* XXXX whoops. we have problems. must deal with this */
 158             }
 159         }
 160       break;
 161     }
 162
 163   case NAME_QUERY_DOMAIN:
 164     {
 165       /* if no response received, there is no domain controller on
 166          this local subnet.  it's ok for us to register
 167          */
 168
 169       if (!n->bcast)
 170         {
 171           DEBUG(0,("NAME_QUERY_DOMAIN incorrectly used - contact samba-bugs!\n"));
 172           /* XXXX whoops. someone's using this to unicast a packet.  this state
 173              should only be used for broadcast checks
 174              */
 175           break;
 176         }
 177       if (n->num_msgs == 0)
 178         {
 179           struct work_record *work = find_workgroupstruct(d,n->name.name,False);
 180           if (work && d)
 181             {
 182               become_domain_master(d,work);
 183             }
 184         }
 185       break;
 186     }
 187
 188   default:
 189     {
 190       /* nothing to do but delete the dead expected-response structure */
 191       /* this is normal. */
 192       break;
 193     }
 194   }
 195 }
 196
 197
 198 /*******************************************************************
 199   remove old name response entries
 200
 201   XXXX retry code needs to be added, including a retry wait period and a count
 202        see name_query() and name_status() for suggested implementation.
 203
 204   ******************************************************************/
 205 void expire_netbios_response_entries(time_t t)
 206 {
 207   struct subnet_record *d;
 208
 209   for (d = subnetlist; d; d = d->next)
 210   {
 211     struct response_record *n, *nextn;
 212
 213     for (n = d->responselist; n; n = nextn)
 214     {
 215           nextn = n->next;
 216
 217       if (n->repeat_time <= t)
 218           {
 219                   if (n->repeat_count > 0)
 220                   {
 221                         /* resend the entry */
 222                         initiate_netbios_packet(&n->response_id, n->fd, n->quest_type,
 223                                                 n->name.name, n->name.name_type,
 224                                       n->nb_flags, n->bcast, n->recurse, n->send_ip);
 225
 226             n->repeat_time += n->repeat_interval; /* XXXX ms needed */
 227             n->repeat_count--;
 228
 229                   }
 230                   else
 231                   {
 232               DEBUG(4,("timeout response %d for %s %s\n",
 233                                                 n->response_id, namestr(&n->name),
 234                         inet_ntoa(n->send_ip)));
 235
 236                           dead_netbios_entry    (d,n); /* process the non-response */
 237               remove_response_record(d,n); /* remove the non-response */
 238
 239                           continue;
 240                    }
 241           }
 242     }
 243   }
 244 }
 245
 246
 247 /****************************************************************************
 248   wrapper function to override a broadcast message and send it to the WINS
 249   name server instead, if it exists. if wins is false, and there has been no
 250   WINS server specified, the packet will NOT be sent.
 251   ****************************************************************************/
 252 struct response_record *queue_netbios_pkt_wins(struct subnet_record *d,
 253                                 int fd,int quest_type,enum state_type state,
 254                             char *name,int name_type,int nb_flags, time_t ttl,
 255                                 int server_type, char *my_name, char *my_comment,
 256                             BOOL bcast,BOOL recurse,
 257                                 struct in_addr send_ip, struct in_addr reply_to_ip)
 258 {
 259   /* XXXX note: please see rfc1001.txt section 10 for details on this
 260      function: it is currently inappropriate to use this - it will do
 261      for now - once there is a clarification of B, M and P nodes and
 262      which one samba is supposed to be
 263    */
 264
 265   if ((!lp_wins_support()) && (*lp_wins_server()))
 266     {
 267       /* samba is not a WINS server, and we are using a WINS server */
 268       struct in_addr wins_ip;
 269       wins_ip = *interpret_addr2(lp_wins_server());
 270
 271       if (!zero_ip(wins_ip))
 272         {
 273           bcast = False;
 274           send_ip = wins_ip;
 275         }
 276       else
 277         {
 278           /* oops. smb.conf's wins server parameter MUST be a host_name
 279              or an ip_address. */
 280           DEBUG(0,("invalid smb.conf parameter 'wins server'\n"));
 281         }
 282     }
 283
 284   if (zero_ip(send_ip)) return NULL;
 285
 286   return queue_netbios_packet(d,fd, quest_type, state,
 287                        name, name_type, nb_flags, ttl,
 288                server_type,my_name,my_comment,
 289                        bcast, recurse, send_ip, reply_to_ip);
 290 }
 291
 292
 293 /****************************************************************************
 294   initiate a netbios name query to find someone's or someones' IP
 295   this is intended to be used (not exclusively) for broadcasting to
 296   master browsers (WORKGROUP(1d or 1b) or __MSBROWSE__(1)) to get
 297   complete lists across a wide area network
 298   ****************************************************************************/
 299 struct response_record *queue_netbios_packet(struct subnet_record *d,
 300                         int fd,int quest_type,enum state_type state,char *name,
 301                         int name_type,int nb_flags, time_t ttl,
 302                         int server_type, char *my_name, char *my_comment,
 303                         BOOL bcast,BOOL recurse,
 304                         struct in_addr send_ip, struct in_addr reply_to_ip)
 305 {
 306   struct response_record *n;
 307   uint16 id = 0xffff;
 308
 309   /* ha ha. no. do NOT broadcast to 255.255.255.255: it's a pseudo address */
 310   if (ip_equal(wins_ip, send_ip)) return NULL;
 311
 312   initiate_netbios_packet(&id, fd, quest_type, name, name_type,
 313                           nb_flags, bcast, recurse, send_ip);
 314
 315   if (id == 0xffff) {
 316     DEBUG(4,("did not initiate netbios packet: %s\n", inet_ntoa(send_ip)));
 317     return NULL;
 318   }
 319
 320   if ((n = make_response_queue_record(state,id,fd,
 321                                       quest_type,name,name_type,nb_flags,ttl,
 322                                       server_type,my_name, my_comment,
 323                                       bcast,recurse,send_ip,reply_to_ip)))
 324     {
 325       add_response_record(d,n);
 326       return n;
 327     }
 328    return NULL;
 329 }