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)
 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)
 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->bcast)
 138           {
 139                 /* broadcast method: implicit acceptance of the name registration
 140                    by not receiving any objections. */
 141
 142                 /* IMPORTANT: see response_name_reg() */
 143
 144                 name_register_work(d,n->name.name,n->name.name_type,
 145                                 n->nb_flags, n->ttl, n->reply_to_ip, n->bcast);
 146           }
 147           else
 148           {
 149                 /* received no response. rfc1001.txt states that after retrying,
 150                    we should assume the WINS server is dead, and fall back to
 151                    broadcasting (see bits about M nodes: can't find any right
 152            now) */
 153
 154                 DEBUG(1,("WINS server did not respond to name registration!\n"));
 155         /* XXXX whoops. we have problems. must deal with this */
 156           }
 157           break;
 158         }
 159
 160         default:
 161         {
 162           /* nothing to do but delete the dead expected-response structure */
 163           /* this is normal. */
 164           break;
 165         }
 166   }
 167 }
 168
 169
 170 /*******************************************************************
 171   remove old name response entries
 172
 173   XXXX retry code needs to be added, including a retry wait period and a count
 174        see name_query() and name_status() for suggested implementation.
 175
 176   ******************************************************************/
 177 void expire_netbios_response_entries()
 178 {
 179   struct subnet_record *d;
 180
 181   for (d = subnetlist; d; d = d->next)
 182   {
 183     struct response_record *n, *nextn;
 184
 185     for (n = d->responselist; n; n = nextn)
 186     {
 187           nextn = n->next;
 188
 189       if (n->repeat_time <= time(NULL))
 190           {
 191                   if (n->repeat_count > 0)
 192                   {
 193                         /* resend the entry */
 194                         initiate_netbios_packet(&n->response_id, n->fd, n->quest_type,
 195                                                 n->name.name, n->name.name_type,
 196                                       n->nb_flags, n->bcast, n->recurse, n->send_ip);
 197
 198             n->repeat_time += n->repeat_interval; /* XXXX ms needed */
 199             n->repeat_count--;
 200
 201                   }
 202                   else
 203                   {
 204               DEBUG(4,("timeout response %d for %s %s\n",
 205                                                 n->response_id, namestr(&n->name),
 206                         inet_ntoa(n->send_ip)));
 207
 208                           dead_netbios_entry    (d,n); /* process the non-response */
 209               remove_response_record(d,n); /* remove the non-response */
 210
 211                           continue;
 212                    }
 213           }
 214     }
 215   }
 216 }
 217
 218
 219 /****************************************************************************
 220   wrapper function to override a broadcast message and send it to the WINS
 221   name server instead, if it exists. if wins is false, and there has been no
 222   WINS server specified, the packet will NOT be sent.
 223   ****************************************************************************/
 224 struct response_record *queue_netbios_pkt_wins(struct subnet_record *d,
 225                                 int fd,int quest_type,enum state_type state,
 226                             char *name,int name_type,int nb_flags, time_t ttl,
 227                                 int server_type, char *my_name, char *my_comment,
 228                             BOOL bcast,BOOL recurse,
 229                                 struct in_addr send_ip, struct in_addr reply_to_ip)
 230 {
 231   /* XXXX note: please see rfc1001.txt section 10 for details on this
 232      function: it is currently inappropriate to use this - it will do
 233      for now - once there is a clarification of B, M and P nodes and
 234      which one samba is supposed to be
 235    */
 236
 237   if ((!lp_wins_support()) && (*lp_wins_server()))
 238     {
 239       /* samba is not a WINS server, and we are using a WINS server */
 240       struct in_addr wins_ip;
 241       wins_ip = *interpret_addr2(lp_wins_server());
 242
 243       if (!zero_ip(wins_ip))
 244         {
 245           bcast = False;
 246           send_ip = wins_ip;
 247         }
 248       else
 249         {
 250           /* oops. smb.conf's wins server parameter MUST be a host_name
 251              or an ip_address. */
 252           DEBUG(0,("invalid smb.conf parameter 'wins server'\n"));
 253         }
 254     }
 255
 256   if (zero_ip(send_ip)) return NULL;
 257
 258   return queue_netbios_packet(d,fd, quest_type, state,
 259                        name, name_type, nb_flags, ttl,
 260                server_type,my_name,my_comment,
 261                        bcast, recurse, send_ip, reply_to_ip);
 262 }
 263
 264
 265 /****************************************************************************
 266   initiate a netbios name query to find someone's or someones' IP
 267   this is intended to be used (not exclusively) for broadcasting to
 268   master browsers (WORKGROUP(1d or 1b) or __MSBROWSE__(1)) to get
 269   complete lists across a wide area network
 270   ****************************************************************************/
 271 struct response_record *queue_netbios_packet(struct subnet_record *d,
 272                         int fd,int quest_type,enum state_type state,char *name,
 273                         int name_type,int nb_flags, time_t ttl,
 274                         int server_type, char *my_name, char *my_comment,
 275                     BOOL bcast,BOOL recurse,
 276                         struct in_addr send_ip, struct in_addr reply_to_ip)
 277 {
 278   struct in_addr wins_ip = ipgrp;
 279   struct response_record *n;
 280   uint16 id = 0xffff;
 281
 282   /* ha ha. no. do NOT broadcast to 255.255.255.255: it's a pseudo address */
 283   if (ip_equal(wins_ip, send_ip)) return NULL;
 284
 285   initiate_netbios_packet(&id, fd, quest_type, name, name_type,
 286                                       nb_flags, bcast, recurse, send_ip);
 287
 288   if (id == 0xffff) {
 289     DEBUG(4,("did not initiate netbios packet: %s\n", inet_ntoa(send_ip)));
 290     return NULL;
 291   }
 292
 293   if ((n = make_response_queue_record(state,id,fd,
 294                                                 quest_type,name,name_type,nb_flags,ttl,
 295                                                 server_type,my_name, my_comment,
 296                                                 bcast,recurse,send_ip,reply_to_ip)))
 297     {
 298       add_response_record(d,n);
 299       return n;
 300     }
 301    return NULL;
 302 }