source/nmbd/nmbd_serverlistdb.c

   1 /*
   2    Unix SMB/Netbios implementation.
   3    Version 1.9.
   4    NBT netbios routines and daemon - version 2
   5    Copyright (C) Andrew Tridgell 1994-1998
   6    Copyright (C) Luke Kenneth Casson Leighton 1994-1998
   7    Copyright (C) Jeremy Allison 1994-1998
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 2 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program; if not, write to the Free Software
  21    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  22
  23 */
  24
  25 #include "includes.h"
  26 #include "smb.h"
  27
  28 extern int ClientNMB;
  29
  30 extern fstring global_myworkgroup;
  31 extern char **my_netbios_names;
  32
  33 int updatecount = 0;
  34
  35 /*******************************************************************
  36   Remove all the servers in a work group.
  37   ******************************************************************/
  38
  39 void remove_all_servers(struct work_record *work)
  40 {
  41   struct server_record *servrec;
  42   struct server_record *nexts;
  43
  44   for (servrec = work->serverlist; servrec; servrec = nexts)
  45   {
  46     DEBUG(7,("remove_all_servers: Removing server %s\n",servrec->serv.name));
  47     nexts = servrec->next;
  48
  49     if (servrec->prev)
  50       servrec->prev->next = servrec->next;
  51     if (servrec->next)
  52       servrec->next->prev = servrec->prev;
  53
  54     if (work->serverlist == servrec)
  55       work->serverlist = servrec->next;
  56
  57     ZERO_STRUCTP(servrec);
  58     SAFE_FREE(servrec);
  59
  60   }
  61
  62   work->subnet->work_changed = True;
  63 }
  64
  65 /***************************************************************************
  66   Add a server into the a workgroup serverlist.
  67   **************************************************************************/
  68
  69 static void add_server_to_workgroup(struct work_record *work,
  70                              struct server_record *servrec)
  71 {
  72   struct server_record *servrec2;
  73
  74   if (!work->serverlist)
  75   {
  76     work->serverlist = servrec;
  77     servrec->prev = NULL;
  78     servrec->next = NULL;
  79     return;
  80   }
  81
  82   for (servrec2 = work->serverlist; servrec2->next; servrec2 = servrec2->next)
  83     ;
  84
  85   servrec2->next = servrec;
  86   servrec->next = NULL;
  87   servrec->prev = servrec2;
  88   work->subnet->work_changed = True;
  89 }
  90
  91 /****************************************************************************
  92   Find a server in a server list.
  93   **************************************************************************/
  94
  95 struct server_record *find_server_in_workgroup(struct work_record *work, char *name)
  96 {
  97   struct server_record *ret;
  98
  99   for (ret = work->serverlist; ret; ret = ret->next)
 100   {
 101     if (strequal(ret->serv.name,name))
 102       return ret;
 103   }
 104   return NULL;
 105 }
 106
 107
 108 /****************************************************************************
 109   Remove a server entry from this workgroup.
 110   ****************************************************************************/
 111
 112 void remove_server_from_workgroup(struct work_record *work, struct server_record *servrec)
 113 {
 114   if (servrec->prev)
 115     servrec->prev->next = servrec->next;
 116   if (servrec->next)
 117     servrec->next->prev = servrec->prev;
 118
 119   if (work->serverlist == servrec)
 120     work->serverlist = servrec->next;
 121
 122   ZERO_STRUCTP(servrec);
 123   SAFE_FREE(servrec);
 124   work->subnet->work_changed = True;
 125 }
 126
 127 /****************************************************************************
 128   Create a server entry on this workgroup.
 129   ****************************************************************************/
 130
 131 struct server_record *create_server_on_workgroup(struct work_record *work,
 132                                                  char *name,int servertype,
 133                                                  int ttl,char *comment)
 134 {
 135   struct server_record *servrec;
 136
 137   if (name[0] == '*')
 138   {
 139       DEBUG(7,("create_server_on_workgroup: not adding name starting with '*' (%s)\n",
 140              name));
 141       return (NULL);
 142   }
 143
 144   if((servrec = find_server_in_workgroup(work, name)) != NULL)
 145   {
 146     DEBUG(0,("create_server_on_workgroup: Server %s already exists on \
 147 workgroup %s. This is a bug.\n", name, work->work_group));
 148     return NULL;
 149   }
 150
 151   if((servrec = (struct server_record *)malloc(sizeof(*servrec))) == NULL)
 152   {
 153     DEBUG(0,("create_server_entry_on_workgroup: malloc fail !\n"));
 154     return NULL;
 155   }
 156
 157   memset((char *)servrec,'\0',sizeof(*servrec));
 158
 159   servrec->subnet = work->subnet;
 160
 161   StrnCpy(servrec->serv.name,name,sizeof(servrec->serv.name)-1);
 162   StrnCpy(servrec->serv.comment,comment,sizeof(servrec->serv.comment)-1);
 163   strupper(servrec->serv.name);
 164   servrec->serv.type  = servertype;
 165
 166   update_server_ttl(servrec, ttl);
 167
 168   add_server_to_workgroup(work, servrec);
 169
 170   DEBUG(3,("create_server_on_workgroup: Created server entry %s of type %x (%s) on \
 171 workgroup %s.\n", name,servertype,comment, work->work_group));
 172
 173   work->subnet->work_changed = True;
 174
 175   return(servrec);
 176 }
 177
 178 /*******************************************************************
 179  Update the ttl field of a server record.
 180 *******************************************************************/
 181
 182 void update_server_ttl(struct server_record *servrec, int ttl)
 183 {
 184   if(ttl > lp_max_ttl())
 185     ttl = lp_max_ttl();
 186
 187   if(is_myname(servrec->serv.name))
 188     servrec->death_time = PERMANENT_TTL;
 189   else
 190     servrec->death_time = (ttl != PERMANENT_TTL) ? time(NULL)+(ttl*3) : PERMANENT_TTL;
 191
 192   servrec->subnet->work_changed = True;
 193 }
 194
 195 /*******************************************************************
 196   Expire old servers in the serverlist. A time of -1 indicates
 197   everybody dies except those with a death_time of PERMANENT_TTL (which is 0).
 198   This should only be called from expire_workgroups_and_servers().
 199   ******************************************************************/
 200
 201 void expire_servers(struct work_record *work, time_t t)
 202 {
 203   struct server_record *servrec;
 204   struct server_record *nexts;
 205
 206   for (servrec = work->serverlist; servrec; servrec = nexts)
 207   {
 208     nexts = servrec->next;
 209
 210     if ((servrec->death_time != PERMANENT_TTL) && ((t == -1) || (servrec->death_time < t)))
 211     {
 212       DEBUG(3,("expire_old_servers: Removing timed out server %s\n",servrec->serv.name));
 213       remove_server_from_workgroup(work, servrec);
 214       work->subnet->work_changed = True;
 215     }
 216   }
 217 }
 218
 219 /*******************************************************************
 220  Decide if we should write out a server record for this server.
 221  We return zero if we should not. Check if we've already written
 222  out this server record from an earlier subnet.
 223 ******************************************************************/
 224
 225 static uint32 write_this_server_name( struct subnet_record *subrec,
 226                                       struct work_record *work,
 227                                       struct server_record *servrec)
 228 {
 229   struct subnet_record *ssub;
 230   struct work_record *iwork;
 231
 232   /* Go through all the subnets we have already seen. */
 233   for (ssub = FIRST_SUBNET; ssub != subrec; ssub = NEXT_SUBNET_INCLUDING_UNICAST(ssub))
 234   {
 235     for(iwork = ssub->workgrouplist; iwork; iwork = iwork->next)
 236     {
 237       if(find_server_in_workgroup( iwork, servrec->serv.name) != NULL)
 238       {
 239         /*
 240          * We have already written out this server record, don't
 241          * do it again. This gives precedence to servers we have seen
 242          * on the broadcast subnets over servers that may have been
 243          * added via a sync on the unicast_subet.
 244          *
 245          * The correct way to do this is to have a serverlist file
 246          * per subnet - this means changes to smbd as well. I may
 247          * add this at a later date (JRA).
 248          */
 249
 250         return 0;
 251       }
 252     }
 253   }
 254
 255   return servrec->serv.type;
 256 }
 257
 258 /*******************************************************************
 259  Decide if we should write out a workgroup record for this workgroup.
 260  We return zero if we should not. Don't write out global_myworkgroup (we've
 261  already done it) and also don't write out a second workgroup record
 262  on the unicast subnet that we've already written out on one of the
 263  broadcast subnets.
 264 ******************************************************************/
 265
 266 static uint32 write_this_workgroup_name( struct subnet_record *subrec,
 267                                          struct work_record *work)
 268 {
 269   struct subnet_record *ssub;
 270
 271   if(strequal(global_myworkgroup, work->work_group))
 272     return 0;
 273
 274   /* This is a workgroup we have seen on a broadcast subnet. All
 275      these have the same type. */
 276
 277   if(subrec != unicast_subnet)
 278     return (SV_TYPE_DOMAIN_ENUM|SV_TYPE_NT|SV_TYPE_LOCAL_LIST_ONLY);
 279
 280   for(ssub = FIRST_SUBNET; ssub;  ssub = NEXT_SUBNET_EXCLUDING_UNICAST(ssub))
 281   {
 282     /* This is the unicast subnet so check if we've already written out
 283        this subnet when we passed over the broadcast subnets. */
 284
 285     if(find_workgroup_on_subnet( ssub, work->work_group) != NULL)
 286       return 0;
 287   }
 288
 289   /* All workgroups on the unicast subnet (except our own, which we
 290      have already written out) cannot be local. */
 291
 292   return (SV_TYPE_DOMAIN_ENUM|SV_TYPE_NT);
 293 }
 294
 295 /*******************************************************************
 296   Write out the browse.dat file.
 297   ******************************************************************/
 298
 299 void write_browse_list_entry(FILE *fp, fstring name, uint32 rec_type,
 300                 fstring local_master_browser_name, fstring description)
 301 {
 302         fstring tmp;
 303
 304         slprintf(tmp,sizeof(tmp)-1, "\"%s\"", name);
 305         fprintf(fp, "%-25s ", tmp);
 306         fprintf(fp, "%08x ", rec_type);
 307         slprintf(tmp, sizeof(tmp)-1, "\"%s\" ", local_master_browser_name);
 308         fprintf(fp, "%-30s", tmp);
 309         fprintf(fp, "\"%s\"\n", description);
 310 }
 311
 312 void write_browse_list(time_t t, BOOL force_write)
 313 {
 314   struct subnet_record *subrec;
 315   struct work_record *work;
 316   struct server_record *servrec;
 317   pstring fname,fnamenew;
 318   uint32 stype;
 319   int i;
 320   FILE *fp;
 321   BOOL list_changed = force_write;
 322   static time_t lasttime = 0;
 323
 324   /* Always dump if we're being told to by a signal. */
 325   if(force_write == False)
 326   {
 327     if (!lasttime)
 328       lasttime = t;
 329     if (t - lasttime < 5)
 330       return;
 331   }
 332
 333   lasttime = t;
 334
 335   dump_workgroups(force_write);
 336
 337   for (subrec = FIRST_SUBNET; subrec ; subrec = NEXT_SUBNET_INCLUDING_UNICAST(subrec))
 338   {
 339     if(subrec->work_changed)
 340     {
 341       list_changed = True;
 342       break;
 343     }
 344   }
 345
 346   if(!list_changed)
 347     return;
 348
 349   updatecount++;
 350
 351   pstrcpy(fname,lp_lockdir());
 352   trim_string(fname,NULL,"/");
 353   pstrcat(fname,"/");
 354   pstrcat(fname,SERVER_LIST);
 355   pstrcpy(fnamenew,fname);
 356   pstrcat(fnamenew,".");
 357
 358   fp = sys_fopen(fnamenew,"w");
 359
 360   if (!fp)
 361   {
 362     DEBUG(0,("write_browse_list: Can't open file %s. Error was %s\n",
 363               fnamenew,strerror(errno)));
 364     return;
 365   }
 366
 367   /*
 368    * Write out a record for our workgroup. Use the record from the first
 369    * subnet.
 370    */
 371
 372   if((work = find_workgroup_on_subnet(FIRST_SUBNET, global_myworkgroup)) == NULL)
 373   {
 374     DEBUG(0,("write_browse_list: Fatal error - cannot find my workgroup %s\n",
 375              global_myworkgroup));
 376     fclose(fp);
 377     return;
 378   }
 379
 380   write_browse_list_entry(fp, work->work_group, SV_TYPE_DOMAIN_ENUM|SV_TYPE_NT|SV_TYPE_LOCAL_LIST_ONLY,
 381      work->local_master_browser_name, work->work_group);
 382
 383   /*
 384    * We need to do something special for our own names.
 385    * This is due to the fact that we may be a local master browser on
 386    * one of our broadcast subnets, and a domain master on the unicast
 387    * subnet. We iterate over the subnets and only write out the name
 388    * once.
 389    */
 390
 391   for (i=0; my_netbios_names[i]; i++)
 392   {
 393     stype = 0;
 394     for (subrec = FIRST_SUBNET; subrec ; subrec = NEXT_SUBNET_INCLUDING_UNICAST(subrec))
 395     {
 396       if((work = find_workgroup_on_subnet( subrec, global_myworkgroup )) == NULL)
 397         continue;
 398       if((servrec = find_server_in_workgroup( work, my_netbios_names[i])) == NULL)
 399         continue;
 400
 401       stype |= servrec->serv.type;
 402     }
 403
 404     /* Output server details, plus what workgroup they're in. */
 405     write_browse_list_entry(fp, my_netbios_names[i], stype,
 406        string_truncate(lp_serverstring(), MAX_SERVER_STRING_LENGTH),
 407        global_myworkgroup);
 408
 409   }
 410
 411   for (subrec = FIRST_SUBNET; subrec ; subrec = NEXT_SUBNET_INCLUDING_UNICAST(subrec))
 412   {
 413     subrec->work_changed = False;
 414
 415     for (work = subrec->workgrouplist; work ; work = work->next)
 416     {
 417       /* Write out a workgroup record for a workgroup. */
 418       uint32 wg_type = write_this_workgroup_name( subrec, work);
 419
 420       if(wg_type)
 421         write_browse_list_entry(fp, work->work_group, wg_type,
 422                                 work->local_master_browser_name,
 423                                 work->work_group);
 424
 425       /* Now write out any server records a workgroup may have. */
 426
 427       for (servrec = work->serverlist; servrec ; servrec = servrec->next)
 428       {
 429         uint32 serv_type;
 430
 431         /* We have already written our names here. */
 432         if(is_myname(servrec->serv.name))
 433           continue;
 434
 435         serv_type = write_this_server_name(subrec, work, servrec);
 436
 437         /* Output server details, plus what workgroup they're in. */
 438         if(serv_type)
 439           write_browse_list_entry(fp, servrec->serv.name, serv_type,
 440                                   servrec->serv.comment, work->work_group);
 441       }
 442     }
 443   }
 444
 445   fclose(fp);
 446   unlink(fname);
 447   chmod(fnamenew,0644);
 448   rename(fnamenew,fname);
 449   DEBUG(3,("write_browse_list: Wrote browse list into file %s\n",fname));
 450 }