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 #include "nmbd/nmbd.h"
  26
  27 int updatecount = 0;
  28
  29 /*******************************************************************
  30   Remove all the servers in a work group.
  31   ******************************************************************/
  32
  33 void remove_all_servers(struct work_record *work)
  34 {
  35         struct server_record *servrec;
  36         struct server_record *nexts;
  37
  38         for (servrec = work->serverlist; servrec; servrec = nexts) {
  39                 DEBUG(7,("remove_all_servers: Removing server %s\n",servrec->serv.name));
  40                 nexts = servrec->next;
  41                 DLIST_REMOVE(work->serverlist, servrec);
  42                 ZERO_STRUCTP(servrec);
  43                 SAFE_FREE(servrec);
  44         }
  45
  46         work->subnet->work_changed = True;
  47 }
  48
  49 /***************************************************************************
  50   Add a server into the a workgroup serverlist.
  51   **************************************************************************/
  52
  53 static void add_server_to_workgroup(struct work_record *work,
  54                              struct server_record *servrec)
  55 {
  56         DLIST_ADD_END(work->serverlist, servrec, struct server_record *);
  57         work->subnet->work_changed = True;
  58 }
  59
  60 /****************************************************************************
  61   Find a server in a server list.
  62   **************************************************************************/
  63
  64 struct server_record *find_server_in_workgroup(struct work_record *work, const char *name)
  65 {
  66         struct server_record *ret;
  67
  68         for (ret = work->serverlist; ret; ret = ret->next) {
  69                 if (strequal(ret->serv.name,name))
  70                         return ret;
  71         }
  72         return NULL;
  73 }
  74
  75
  76 /****************************************************************************
  77   Remove a server entry from this workgroup.
  78   ****************************************************************************/
  79
  80 void remove_server_from_workgroup(struct work_record *work, struct server_record *servrec)
  81 {
  82         DLIST_REMOVE(work->serverlist, servrec);
  83         ZERO_STRUCTP(servrec);
  84         SAFE_FREE(servrec);
  85         work->subnet->work_changed = True;
  86 }
  87
  88 /****************************************************************************
  89   Create a server entry on this workgroup.
  90   ****************************************************************************/
  91
  92 struct server_record *create_server_on_workgroup(struct work_record *work,
  93                                                  const char *name,int servertype,
  94                                                  int ttl, const char *comment)
  95 {
  96         struct server_record *servrec;
  97
  98         if (name[0] == '*') {
  99                 DEBUG(7,("create_server_on_workgroup: not adding name starting with '*' (%s)\n",
 100                         name));
 101                 return (NULL);
 102         }
 103
 104         if(find_server_in_workgroup(work, name) != NULL) {
 105                 DEBUG(0,("create_server_on_workgroup: Server %s already exists on \
 106 workgroup %s. This is a bug.\n", name, work->work_group));
 107                 return NULL;
 108         }
 109
 110         if((servrec = SMB_MALLOC_P(struct server_record)) == NULL) {
 111                 DEBUG(0,("create_server_entry_on_workgroup: malloc fail !\n"));
 112                 return NULL;
 113         }
 114
 115         memset((char *)servrec,'\0',sizeof(*servrec));
 116
 117         servrec->subnet = work->subnet;
 118
 119         fstrcpy(servrec->serv.name,name);
 120         fstrcpy(servrec->serv.comment,comment);
 121         strupper_m(servrec->serv.name);
 122         servrec->serv.type  = servertype;
 123
 124         update_server_ttl(servrec, ttl);
 125
 126         add_server_to_workgroup(work, servrec);
 127
 128         DEBUG(3,("create_server_on_workgroup: Created server entry %s of type %x (%s) on \
 129 workgroup %s.\n", name,servertype,comment, work->work_group));
 130
 131         work->subnet->work_changed = True;
 132
 133         return(servrec);
 134 }
 135
 136 /*******************************************************************
 137  Update the ttl field of a server record.
 138 *******************************************************************/
 139
 140 void update_server_ttl(struct server_record *servrec, int ttl)
 141 {
 142         if(ttl > lp_max_ttl())
 143                 ttl = lp_max_ttl();
 144
 145         if(is_myname(servrec->serv.name))
 146                 servrec->death_time = PERMANENT_TTL;
 147         else
 148                 servrec->death_time = (ttl != PERMANENT_TTL) ? time(NULL)+(ttl*3) : PERMANENT_TTL;
 149
 150         servrec->subnet->work_changed = True;
 151 }
 152
 153 /*******************************************************************
 154   Expire old servers in the serverlist. A time of -1 indicates
 155   everybody dies except those with a death_time of PERMANENT_TTL (which is 0).
 156   This should only be called from expire_workgroups_and_servers().
 157   ******************************************************************/
 158
 159 void expire_servers(struct work_record *work, time_t t)
 160 {
 161         struct server_record *servrec;
 162         struct server_record *nexts;
 163
 164         for (servrec = work->serverlist; servrec; servrec = nexts) {
 165                 nexts = servrec->next;
 166
 167                 if ((servrec->death_time != PERMANENT_TTL) && ((t == -1) || (servrec->death_time < t))) {
 168                         DEBUG(3,("expire_old_servers: Removing timed out server %s\n",servrec->serv.name));
 169                         remove_server_from_workgroup(work, servrec);
 170                         work->subnet->work_changed = True;
 171                 }
 172         }
 173 }
 174
 175 /*******************************************************************
 176  Decide if we should write out a server record for this server.
 177  We return zero if we should not. Check if we've already written
 178  out this server record from an earlier subnet.
 179 ******************************************************************/
 180
 181 static uint32 write_this_server_name( struct subnet_record *subrec,
 182                                       struct work_record *work,
 183                                       struct server_record *servrec)
 184 {
 185         struct subnet_record *ssub;
 186         struct work_record *iwork;
 187
 188         /* Go through all the subnets we have already seen. */
 189         for (ssub = FIRST_SUBNET; ssub && (ssub != subrec); ssub = NEXT_SUBNET_INCLUDING_UNICAST(ssub)) {
 190                 for(iwork = ssub->workgrouplist; iwork; iwork = iwork->next) {
 191                         if(find_server_in_workgroup( iwork, servrec->serv.name) != NULL) {
 192                                 /*
 193                                  * We have already written out this server record, don't
 194                                  * do it again. This gives precedence to servers we have seen
 195                                  * on the broadcast subnets over servers that may have been
 196                                  * added via a sync on the unicast_subet.
 197                                  *
 198                                  * The correct way to do this is to have a serverlist file
 199                                  * per subnet - this means changes to smbd as well. I may
 200                                  * add this at a later date (JRA).
 201                                  */
 202
 203                                 return 0;
 204                         }
 205                 }
 206         }
 207
 208         return servrec->serv.type;
 209 }
 210
 211 /*******************************************************************
 212  Decide if we should write out a workgroup record for this workgroup.
 213  We return zero if we should not. Don't write out lp_workgroup() (we've
 214  already done it) and also don't write out a second workgroup record
 215  on the unicast subnet that we've already written out on one of the
 216  broadcast subnets.
 217 ******************************************************************/
 218
 219 static uint32 write_this_workgroup_name( struct subnet_record *subrec,
 220                                          struct work_record *work)
 221 {
 222         struct subnet_record *ssub;
 223
 224         if(strequal(lp_workgroup(), work->work_group))
 225                 return 0;
 226
 227         /* This is a workgroup we have seen on a broadcast subnet. All
 228                 these have the same type. */
 229
 230         if(subrec != unicast_subnet)
 231                 return (SV_TYPE_DOMAIN_ENUM|SV_TYPE_NT|SV_TYPE_LOCAL_LIST_ONLY);
 232
 233         for(ssub = FIRST_SUBNET; ssub;  ssub = NEXT_SUBNET_EXCLUDING_UNICAST(ssub)) {
 234                 /* This is the unicast subnet so check if we've already written out
 235                         this subnet when we passed over the broadcast subnets. */
 236
 237                 if(find_workgroup_on_subnet( ssub, work->work_group) != NULL)
 238                         return 0;
 239         }
 240
 241         /* All workgroups on the unicast subnet (except our own, which we
 242                 have already written out) cannot be local. */
 243
 244         return (SV_TYPE_DOMAIN_ENUM|SV_TYPE_NT);
 245 }
 246
 247 /*******************************************************************
 248   Write out the browse.dat file.
 249   ******************************************************************/
 250
 251 void write_browse_list_entry(XFILE *fp, const char *name, uint32 rec_type,
 252                 const char *local_master_browser_name, const char *description)
 253 {
 254         fstring tmp;
 255
 256         slprintf(tmp,sizeof(tmp)-1, "\"%s\"", name);
 257         x_fprintf(fp, "%-25s ", tmp);
 258         x_fprintf(fp, "%08x ", rec_type);
 259         slprintf(tmp, sizeof(tmp)-1, "\"%s\" ", local_master_browser_name);
 260         x_fprintf(fp, "%-30s", tmp);
 261         x_fprintf(fp, "\"%s\"\n", description);
 262 }
 263
 264 void write_browse_list(time_t t, bool force_write)
 265 {
 266         struct subnet_record *subrec;
 267         struct work_record *work;
 268         struct server_record *servrec;
 269         char *fname;
 270         char *fnamenew;
 271         uint32 stype;
 272         int i;
 273         XFILE *fp;
 274         bool list_changed = force_write;
 275         static time_t lasttime = 0;
 276         TALLOC_CTX *ctx = talloc_tos();
 277
 278         /* Always dump if we're being told to by a signal. */
 279         if(force_write == False) {
 280                 if (!lasttime)
 281                         lasttime = t;
 282                 if (t - lasttime < 5)
 283                         return;
 284         }
 285
 286         lasttime = t;
 287
 288         dump_workgroups(force_write);
 289
 290         for (subrec = FIRST_SUBNET; subrec ; subrec = NEXT_SUBNET_INCLUDING_UNICAST(subrec)) {
 291                 if(subrec->work_changed) {
 292                         list_changed = True;
 293                         break;
 294                 }
 295         }
 296
 297         if(!list_changed)
 298                 return;
 299
 300         updatecount++;
 301
 302         fname = cache_path(SERVER_LIST);
 303         if (!fname) {
 304                 return;
 305         }
 306         fnamenew = talloc_asprintf(ctx, "%s.",
 307                                 fname);
 308         if (!fnamenew) {
 309                 return;
 310         }
 311
 312         fp = x_fopen(fnamenew,O_WRONLY|O_CREAT|O_TRUNC, 0644);
 313
 314         if (!fp) {
 315                 DEBUG(0,("write_browse_list: Can't open file %s. Error was %s\n",
 316                         fnamenew,strerror(errno)));
 317                 return;
 318         }
 319
 320         /*
 321          * Write out a record for our workgroup. Use the record from the first
 322          * subnet.
 323          */
 324
 325         if((work = find_workgroup_on_subnet(FIRST_SUBNET, lp_workgroup())) == NULL) {
 326                 DEBUG(0,("write_browse_list: Fatal error - cannot find my workgroup %s\n",
 327                         lp_workgroup()));
 328                 x_fclose(fp);
 329                 return;
 330         }
 331
 332         write_browse_list_entry(fp, work->work_group,
 333                 SV_TYPE_DOMAIN_ENUM|SV_TYPE_NT|SV_TYPE_LOCAL_LIST_ONLY,
 334                 work->local_master_browser_name, work->work_group);
 335
 336         /*
 337          * We need to do something special for our own names.
 338          * This is due to the fact that we may be a local master browser on
 339          * one of our broadcast subnets, and a domain master on the unicast
 340          * subnet. We iterate over the subnets and only write out the name
 341          * once.
 342          */
 343
 344         for (i=0; my_netbios_names(i); i++) {
 345                 stype = 0;
 346                 for (subrec = FIRST_SUBNET; subrec ; subrec = NEXT_SUBNET_INCLUDING_UNICAST(subrec)) {
 347                         if((work = find_workgroup_on_subnet( subrec, lp_workgroup() )) == NULL)
 348                                 continue;
 349                         if((servrec = find_server_in_workgroup( work, my_netbios_names(i))) == NULL)
 350                                 continue;
 351
 352                         stype |= servrec->serv.type;
 353                 }
 354
 355                 /* Output server details, plus what workgroup they're in. */
 356                 write_browse_list_entry(fp, my_netbios_names(i), stype,
 357                         string_truncate(lp_serverstring(), MAX_SERVER_STRING_LENGTH), lp_workgroup());
 358         }
 359
 360         for (subrec = FIRST_SUBNET; subrec ; subrec = NEXT_SUBNET_INCLUDING_UNICAST(subrec)) {
 361                 subrec->work_changed = False;
 362
 363                 for (work = subrec->workgrouplist; work ; work = work->next) {
 364                         /* Write out a workgroup record for a workgroup. */
 365                         uint32 wg_type = write_this_workgroup_name( subrec, work);
 366
 367                         if(wg_type) {
 368                                 write_browse_list_entry(fp, work->work_group, wg_type,
 369                                                 work->local_master_browser_name,
 370                                                 work->work_group);
 371                         }
 372
 373                         /* Now write out any server records a workgroup may have. */
 374
 375                         for (servrec = work->serverlist; servrec ; servrec = servrec->next) {
 376                                 uint32 serv_type;
 377
 378                                 /* We have already written our names here. */
 379                                 if(is_myname(servrec->serv.name))
 380                                         continue;
 381
 382                                 serv_type = write_this_server_name(subrec, work, servrec);
 383                                 if(serv_type) {
 384                                         /* Output server details, plus what workgroup they're in. */
 385                                         write_browse_list_entry(fp, servrec->serv.name, serv_type,
 386                                                 servrec->serv.comment, work->work_group);
 387                                 }
 388                         }
 389                 }
 390         }
 391
 392         x_fclose(fp);
 393         unlink(fname);
 394         chmod(fnamenew,0644);
 395         rename(fnamenew,fname);
 396         DEBUG(3,("write_browse_list: Wrote browse list into file %s\n",fname));
 397 }