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 ipgrp;
  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(ipgrp);
  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             if (ismyip(n->send_ip))
 180             {
 181           struct work_record *work = find_workgroupstruct(d,n->name.name,False);
 182           if (work && d)
 183           {
 184                     become_domain_master(d,work);
 185           }
 186         }
 187           }
 188           break;
 189         }
 190
 191         default:
 192         {
 193           /* nothing to do but delete the dead expected-response structure */
 194           /* this is normal. */
 195           break;
 196         }
 197   }
 198 }
 199
 200
 201 /*******************************************************************
 202   remove old name response entries
 203
 204   XXXX retry code needs to be added, including a retry wait period and a count
 205        see name_query() and name_status() for suggested implementation.
 206
 207   ******************************************************************/
 208 void expire_netbios_response_entries(time_t t)
 209 {
 210   struct subnet_record *d;
 211
 212   for (d = subnetlist; d; d = d->next)
 213   {
 214     struct response_record *n, *nextn;
 215
 216     for (n = d->responselist; n; n = nextn)
 217     {
 218           nextn = n->next;
 219
 220       if (n->repeat_time <= t)
 221           {
 222                   if (n->repeat_count > 0)
 223                   {
 224                         /* resend the entry */
 225                         initiate_netbios_packet(&n->response_id, n->fd, n->quest_type,
 226                                                 n->name.name, n->name.name_type,
 227                                       n->nb_flags, n->bcast, n->recurse, n->send_ip);
 228
 229             n->repeat_time += n->repeat_interval; /* XXXX ms needed */
 230             n->repeat_count--;
 231
 232                   }
 233                   else
 234                   {
 235               DEBUG(4,("timeout response %d for %s %s\n",
 236                                                 n->response_id, namestr(&n->name),
 237                         inet_ntoa(n->send_ip)));
 238
 239                           dead_netbios_entry    (d,n); /* process the non-response */
 240               remove_response_record(d,n); /* remove the non-response */
 241
 242                           continue;
 243                    }
 244           }
 245     }
 246   }
 247 }
 248
 249
 250 /****************************************************************************
 251   wrapper function to override a broadcast message and send it to the WINS
 252   name server instead, if it exists. if wins is false, and there has been no
 253   WINS server specified, the packet will NOT be sent.
 254   ****************************************************************************/
 255 struct response_record *queue_netbios_pkt_wins(struct subnet_record *d,
 256                                 int fd,int quest_type,enum state_type state,
 257                             char *name,int name_type,int nb_flags, time_t ttl,
 258                                 int server_type, char *my_name, char *my_comment,
 259                             BOOL bcast,BOOL recurse,
 260                                 struct in_addr send_ip, struct in_addr reply_to_ip)
 261 {
 262   /* XXXX note: please see rfc1001.txt section 10 for details on this
 263      function: it is currently inappropriate to use this - it will do
 264      for now - once there is a clarification of B, M and P nodes and
 265      which one samba is supposed to be
 266    */
 267
 268   if ((!lp_wins_support()) && (*lp_wins_server()))
 269     {
 270       /* samba is not a WINS server, and we are using a WINS server */
 271       struct in_addr wins_ip;
 272       wins_ip = *interpret_addr2(lp_wins_server());
 273
 274       if (!zero_ip(wins_ip))
 275         {
 276           bcast = False;
 277           send_ip = wins_ip;
 278         }
 279       else
 280         {
 281           /* oops. smb.conf's wins server parameter MUST be a host_name
 282              or an ip_address. */
 283           DEBUG(0,("invalid smb.conf parameter 'wins server'\n"));
 284         }
 285     }
 286
 287   if (zero_ip(send_ip)) return NULL;
 288
 289   return queue_netbios_packet(d,fd, quest_type, state,
 290                        name, name_type, nb_flags, ttl,
 291                server_type,my_name,my_comment,
 292                        bcast, recurse, send_ip, reply_to_ip);
 293 }
 294
 295
 296 /****************************************************************************
 297   initiate a netbios name query to find someone's or someones' IP
 298   this is intended to be used (not exclusively) for broadcasting to
 299   master browsers (WORKGROUP(1d or 1b) or __MSBROWSE__(1)) to get
 300   complete lists across a wide area network
 301   ****************************************************************************/
 302 struct response_record *queue_netbios_packet(struct subnet_record *d,
 303                         int fd,int quest_type,enum state_type state,char *name,
 304                         int name_type,int nb_flags, time_t ttl,
 305                         int server_type, char *my_name, char *my_comment,
 306                     BOOL bcast,BOOL recurse,
 307                         struct in_addr send_ip, struct in_addr reply_to_ip)
 308 {
 309   struct in_addr wins_ip = ipgrp;
 310   struct response_record *n;
 311   uint16 id = 0xffff;
 312
 313   /* ha ha. no. do NOT broadcast to 255.255.255.255: it's a pseudo address */
 314   if (ip_equal(wins_ip, send_ip)) return NULL;
 315
 316   initiate_netbios_packet(&id, fd, quest_type, name, name_type,
 317                                       nb_flags, bcast, recurse, send_ip);
 318
 319   if (id == 0xffff) {
 320     DEBUG(4,("did not initiate netbios packet: %s\n", inet_ntoa(send_ip)));
 321     return NULL;
 322   }
 323
 324   if ((n = make_response_queue_record(state,id,fd,
 325                                                 quest_type,name,name_type,nb_flags,ttl,
 326                                                 server_type,my_name, my_comment,
 327                                                 bcast,recurse,send_ip,reply_to_ip)))
 328     {
 329       add_response_record(d,n);
 330       return n;
 331     }
 332    return NULL;
 333 }