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