source3/nmbd/nmbd_serverlistdb.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 3 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, see <http://www.gnu.org/licenses/>.
  20
  21 */
  22
  23 #include "includes.h"
  24 #include "../librpc/gen_ndr/svcctl.h"
  25
  26 int updatecount = 0;
  27
  28 /*******************************************************************
  29   Remove all the servers in a work group.
  30   ******************************************************************/
  31
  32 void remove_all_servers(struct work_record *work)
  33 {
  34         struct server_record *servrec;
  35         struct server_record *nexts;
  36
  37         for (servrec = work->serverlist; servrec; servrec = nexts) {
  38                 DEBUG(7,("remove_all_servers: Removing server %s\n",servrec->serv.name));
  39                 nexts = servrec->next;
  40                 DLIST_REMOVE(work->serverlist, servrec);
  41                 ZERO_STRUCTP(servrec);
  42                 SAFE_FREE(servrec);
  43         }
  44
  45         work->subnet->work_changed = True;
  46 }
  47
  48 /***************************************************************************
  49   Add a server into the a workgroup serverlist.
  50   **************************************************************************/
  51
  52 static void add_server_to_workgroup(struct work_record *work,
  53                              struct server_record *servrec)
  54 {
  55         DLIST_ADD_END(work->serverlist, servrec, struct server_record *);
  56         work->subnet->work_changed = True;
  57 }
  58
  59 /****************************************************************************
  60   Find a server in a server list.
  61   **************************************************************************/
  62
  63 struct server_record *find_server_in_workgroup(struct work_record *work, const char *name)
  64 {
  65         struct server_record *ret;
  66
  67         for (ret = work->serverlist; ret; ret = ret->next) {
  68                 if (strequal(ret->serv.name,name))
  69                         return ret;
  70         }
  71         return NULL;
  72 }
  73
  74
  75 /****************************************************************************
  76   Remove a server entry from this workgroup.
  77   ****************************************************************************/
  78
  79 void remove_server_from_workgroup(struct work_record *work, struct server_record *servrec)
  80 {
  81         DLIST_REMOVE(work->serverlist, servrec);
  82         ZERO_STRUCTP(servrec);
  83         SAFE_FREE(servrec);
  84         work->subnet->work_changed = True;
  85 }
  86
  87 /****************************************************************************
  88   Create a server entry on this workgroup.
  89   ****************************************************************************/
  90
  91 struct server_record *create_server_on_workgroup(struct work_record *work,
  92                                                  const char *name,int servertype,
  93                                                  int ttl, const char *comment)
  94 {
  95         struct server_record *servrec;
  96
  97         if (name[0] == '*') {
  98                 DEBUG(7,("create_server_on_workgroup: not adding name starting with '*' (%s)\n",
  99                         name));
 100                 return (NULL);
 101         }
 102
 103         if(find_server_in_workgroup(work, name) != NULL) {
 104                 DEBUG(0,("create_server_on_workgroup: Server %s already exists on \
 105 workgroup %s. This is a bug.\n", name, work->work_group));
 106                 return NULL;
 107         }
 108
 109         if((servrec = SMB_MALLOC_P(struct server_record)) == NULL) {
 110                 DEBUG(0,("create_server_entry_on_workgroup: malloc fail !\n"));
 111                 return NULL;
 112         }
 113
 114         memset((char *)servrec,'\0',sizeof(*servrec));
 115
 116         servrec->subnet = work->subnet;
 117
 118         fstrcpy(servrec->serv.name,name);
 119         fstrcpy(servrec->serv.comment,comment);
 120         strupper_m(servrec->serv.name);
 121         servrec->serv.type  = servertype;
 122
 123         update_server_ttl(servrec, ttl);
 124
 125         add_server_to_workgroup(work, servrec);
 126
 127         DEBUG(3,("create_server_on_workgroup: Created server entry %s of type %x (%s) on \
 128 workgroup %s.\n", name,servertype,comment, work->work_group));
 129
 130         work->subnet->work_changed = True;
 131
 132         return(servrec);
 133 }
 134
 135 /*******************************************************************
 136  Update the ttl field of a server record.
 137 *******************************************************************/
 138
 139 void update_server_ttl(struct server_record *servrec, int ttl)
 140 {
 141         if(ttl > lp_max_ttl())
 142                 ttl = lp_max_ttl();
 143
 144         if(is_myname(servrec->serv.name))
 145                 servrec->death_time = PERMANENT_TTL;
 146         else
 147                 servrec->death_time = (ttl != PERMANENT_TTL) ? time(NULL)+(ttl*3) : PERMANENT_TTL;
 148
 149         servrec->subnet->work_changed = True;
 150 }
 151
 152 /*******************************************************************
 153   Expire old servers in the serverlist. A time of -1 indicates
 154   everybody dies except those with a death_time of PERMANENT_TTL (which is 0).
 155   This should only be called from expire_workgroups_and_servers().
 156   ******************************************************************/
 157
 158 void expire_servers(struct work_record *work, time_t t)
 159 {
 160         struct server_record *servrec;
 161         struct server_record *nexts;
 162
 163         for (servrec = work->serverlist; servrec; servrec = nexts) {
 164                 nexts = servrec->next;
 165
 166                 if ((servrec->death_time != PERMANENT_TTL) && ((t == -1) || (servrec->death_time < t))) {
 167                         DEBUG(3,("expire_old_servers: Removing timed out server %s\n",servrec->serv.name));
 168                         remove_server_from_workgroup(work, servrec);
 169                         work->subnet->work_changed = True;
 170                 }
 171         }
 172 }
 173
 174 /*******************************************************************
 175  Decide if we should write out a server record for this server.
 176  We return zero if we should not. Check if we've already written
 177  out this server record from an earlier subnet.
 178 ******************************************************************/
 179
 180 static uint32 write_this_server_name( struct subnet_record *subrec,
 181                                       struct work_record *work,
 182                                       struct server_record *servrec)
 183 {
 184         struct subnet_record *ssub;
 185         struct work_record *iwork;
 186
 187         /* Go through all the subnets we have already seen. */
 188         for (ssub = FIRST_SUBNET; ssub && (ssub != subrec); ssub = NEXT_SUBNET_INCLUDING_UNICAST(ssub)) {
 189                 for(iwork = ssub->workgrouplist; iwork; iwork = iwork->next) {
 190                         if(find_server_in_workgroup( iwork, servrec->serv.name) != NULL) {
 191                                 /*
 192                                  * We have already written out this server record, don't
 193                                  * do it again. This gives precedence to servers we have seen
 194                                  * on the broadcast subnets over servers that may have been
 195                                  * added via a sync on the unicast_subet.
 196                                  *
 197                                  * The correct way to do this is to have a serverlist file
 198                                  * per subnet - this means changes to smbd as well. I may
 199                                  * add this at a later date (JRA).
 200                                  */
 201
 202                                 return 0;
 203                         }
 204                 }
 205         }
 206
 207         return servrec->serv.type;
 208 }
 209
 210 /*******************************************************************
 211  Decide if we should write out a workgroup record for this workgroup.
 212  We return zero if we should not. Don't write out lp_workgroup() (we've
 213  already done it) and also don't write out a second workgroup record
 214  on the unicast subnet that we've already written out on one of the
 215  broadcast subnets.
 216 ******************************************************************/
 217
 218 static uint32 write_this_workgroup_name( struct subnet_record *subrec,
 219                                          struct work_record *work)
 220 {
 221         struct subnet_record *ssub;
 222
 223         if(strequal(lp_workgroup(), work->work_group))
 224                 return 0;
 225
 226         /* This is a workgroup we have seen on a broadcast subnet. All
 227                 these have the same type. */
 228
 229         if(subrec != unicast_subnet)
 230                 return (SV_TYPE_DOMAIN_ENUM|SV_TYPE_NT|SV_TYPE_LOCAL_LIST_ONLY);
 231
 232         for(ssub = FIRST_SUBNET; ssub;  ssub = NEXT_SUBNET_EXCLUDING_UNICAST(ssub)) {
 233                 /* This is the unicast subnet so check if we've already written out
 234                         this subnet when we passed over the broadcast subnets. */
 235
 236                 if(find_workgroup_on_subnet( ssub, work->work_group) != NULL)
 237                         return 0;
 238         }
 239
 240         /* All workgroups on the unicast subnet (except our own, which we
 241                 have already written out) cannot be local. */
 242
 243         return (SV_TYPE_DOMAIN_ENUM|SV_TYPE_NT);
 244 }
 245
 246 /*******************************************************************
 247   Write out the browse.dat file.
 248   ******************************************************************/
 249
 250 void write_browse_list_entry(XFILE *fp, const char *name, uint32 rec_type,
 251                 const char *local_master_browser_name, const char *description)
 252 {
 253         fstring tmp;
 254
 255         slprintf(tmp,sizeof(tmp)-1, "\"%s\"", name);
 256         x_fprintf(fp, "%-25s ", tmp);
 257         x_fprintf(fp, "%08x ", rec_type);
 258         slprintf(tmp, sizeof(tmp)-1, "\"%s\" ", local_master_browser_name);
 259         x_fprintf(fp, "%-30s", tmp);
 260         x_fprintf(fp, "\"%s\"\n", description);
 261 }
 262
 263 void write_browse_list(time_t t, bool force_write)
 264 {
 265         struct subnet_record *subrec;
 266         struct work_record *work;
 267         struct server_record *servrec;
 268         char *fname;
 269         char *fnamenew;
 270         uint32 stype;
 271         int i;
 272         XFILE *fp;
 273         bool list_changed = force_write;
 274         static time_t lasttime = 0;
 275         TALLOC_CTX *ctx = talloc_tos();
 276
 277         /* Always dump if we're being told to by a signal. */
 278         if(force_write == False) {
 279                 if (!lasttime)
 280                         lasttime = t;
 281                 if (t - lasttime < 5)
 282                         return;
 283         }
 284
 285         lasttime = t;
 286
 287         dump_workgroups(force_write);
 288
 289         for (subrec = FIRST_SUBNET; subrec ; subrec = NEXT_SUBNET_INCLUDING_UNICAST(subrec)) {
 290                 if(subrec->work_changed) {
 291                         list_changed = True;
 292                         break;
 293                 }
 294         }
 295
 296         if(!list_changed)
 297                 return;
 298
 299         updatecount++;
 300
 301         fname = cache_path(SERVER_LIST);
 302         if (!fname) {
 303                 return;
 304         }
 305         fnamenew = talloc_asprintf(ctx, "%s.",
 306                                 fname);
 307         if (!fnamenew) {
 308                 return;
 309         }
 310
 311         fp = x_fopen(fnamenew,O_WRONLY|O_CREAT|O_TRUNC, 0644);
 312
 313         if (!fp) {
 314                 DEBUG(0,("write_browse_list: Can't open file %s. Error was %s\n",
 315                         fnamenew,strerror(errno)));
 316                 return;
 317         }
 318
 319         /*
 320          * Write out a record for our workgroup. Use the record from the first
 321          * subnet.
 322          */
 323
 324         if((work = find_workgroup_on_subnet(FIRST_SUBNET, lp_workgroup())) == NULL) {
 325                 DEBUG(0,("write_browse_list: Fatal error - cannot find my workgroup %s\n",
 326                         lp_workgroup()));
 327                 x_fclose(fp);
 328                 return;
 329         }
 330
 331         write_browse_list_entry(fp, work->work_group,
 332                 SV_TYPE_DOMAIN_ENUM|SV_TYPE_NT|SV_TYPE_LOCAL_LIST_ONLY,
 333                 work->local_master_browser_name, work->work_group);
 334
 335         /*
 336          * We need to do something special for our own names.
 337          * This is due to the fact that we may be a local master browser on
 338          * one of our broadcast subnets, and a domain master on the unicast
 339          * subnet. We iterate over the subnets and only write out the name
 340          * once.
 341          */
 342
 343         for (i=0; my_netbios_names(i); i++) {
 344                 stype = 0;
 345                 for (subrec = FIRST_SUBNET; subrec ; subrec = NEXT_SUBNET_INCLUDING_UNICAST(subrec)) {
 346                         if((work = find_workgroup_on_subnet( subrec, lp_workgroup() )) == NULL)
 347                                 continue;
 348                         if((servrec = find_server_in_workgroup( work, my_netbios_names(i))) == NULL)
 349                                 continue;
 350
 351                         stype |= servrec->serv.type;
 352                 }
 353
 354                 /* Output server details, plus what workgroup they're in. */
 355                 write_browse_list_entry(fp, my_netbios_names(i), stype,
 356                         string_truncate(lp_serverstring(), MAX_SERVER_STRING_LENGTH), lp_workgroup());
 357         }
 358
 359         for (subrec = FIRST_SUBNET; subrec ; subrec = NEXT_SUBNET_INCLUDING_UNICAST(subrec)) {
 360                 subrec->work_changed = False;
 361
 362                 for (work = subrec->workgrouplist; work ; work = work->next) {
 363                         /* Write out a workgroup record for a workgroup. */
 364                         uint32 wg_type = write_this_workgroup_name( subrec, work);
 365
 366                         if(wg_type) {
 367                                 write_browse_list_entry(fp, work->work_group, wg_type,
 368                                                 work->local_master_browser_name,
 369                                                 work->work_group);
 370                         }
 371
 372                         /* Now write out any server records a workgroup may have. */
 373
 374                         for (servrec = work->serverlist; servrec ; servrec = servrec->next) {
 375                                 uint32 serv_type;
 376
 377                                 /* We have already written our names here. */
 378                                 if(is_myname(servrec->serv.name))
 379                                         continue;
 380
 381                                 serv_type = write_this_server_name(subrec, work, servrec);
 382                                 if(serv_type) {
 383                                         /* Output server details, plus what workgroup they're in. */
 384                                         write_browse_list_entry(fp, servrec->serv.name, serv_type,
 385                                                 servrec->serv.comment, work->work_group);
 386                                 }
 387                         }
 388                 }
 389         }
 390
 391         x_fclose(fp);
 392         unlink(fname);
 393         chmod(fnamenew,0644);
 394         rename(fnamenew,fname);
 395         DEBUG(3,("write_browse_list: Wrote browse list into file %s\n",fname));
 396 }