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 "system/filesys.h"
  25 #include "../librpc/gen_ndr/svcctl.h"
  26 #include "nmbd/nmbd.h"
  27
  28 int updatecount = 0;
  29
  30 /*******************************************************************
  31   Remove all the servers in a work group.
  32   ******************************************************************/
  33
  34 void remove_all_servers(struct work_record *work)
  35 {
  36         struct server_record *servrec;
  37         struct server_record *nexts;
  38
  39         for (servrec = work->serverlist; servrec; servrec = nexts) {
  40                 DEBUG(7,("remove_all_servers: Removing server %s\n",servrec->serv.name));
  41                 nexts = servrec->next;
  42                 DLIST_REMOVE(work->serverlist, servrec);
  43                 ZERO_STRUCTP(servrec);
  44                 SAFE_FREE(servrec);
  45         }
  46
  47         work->subnet->work_changed = True;
  48 }
  49
  50 /***************************************************************************
  51   Add a server into the a workgroup serverlist.
  52   **************************************************************************/
  53
  54 static void add_server_to_workgroup(struct work_record *work,
  55                              struct server_record *servrec)
  56 {
  57         DLIST_ADD_END(work->serverlist, servrec);
  58         work->subnet->work_changed = True;
  59 }
  60
  61 /****************************************************************************
  62   Find a server in a server list.
  63   **************************************************************************/
  64
  65 struct server_record *find_server_in_workgroup(struct work_record *work, const char *name)
  66 {
  67         struct server_record *ret;
  68
  69         for (ret = work->serverlist; ret; ret = ret->next) {
  70                 if (strequal(ret->serv.name,name))
  71                         return ret;
  72         }
  73         return NULL;
  74 }
  75
  76
  77 /****************************************************************************
  78   Remove a server entry from this workgroup.
  79   ****************************************************************************/
  80
  81 void remove_server_from_workgroup(struct work_record *work, struct server_record *servrec)
  82 {
  83         DLIST_REMOVE(work->serverlist, servrec);
  84         ZERO_STRUCTP(servrec);
  85         SAFE_FREE(servrec);
  86         work->subnet->work_changed = True;
  87 }
  88
  89 /****************************************************************************
  90   Create a server entry on this workgroup.
  91   ****************************************************************************/
  92
  93 struct server_record *create_server_on_workgroup(struct work_record *work,
  94                                                  const char *name,int servertype,
  95                                                  int ttl, const char *comment)
  96 {
  97         struct server_record *servrec;
  98
  99         if (name[0] == '*') {
 100                 DEBUG(7,("create_server_on_workgroup: not adding name starting with '*' (%s)\n",
 101                         name));
 102                 return (NULL);
 103         }
 104
 105         if(find_server_in_workgroup(work, name) != NULL) {
 106                 DEBUG(0,("create_server_on_workgroup: Server %s already exists on \
 107 workgroup %s. This is a bug.\n", name, work->work_group));
 108                 return NULL;
 109         }
 110
 111         if((servrec = SMB_MALLOC_P(struct server_record)) == NULL) {
 112                 DEBUG(0,("create_server_entry_on_workgroup: malloc fail !\n"));
 113                 return NULL;
 114         }
 115
 116         memset((char *)servrec,'\0',sizeof(*servrec));
 117
 118         servrec->subnet = work->subnet;
 119
 120         fstrcpy(servrec->serv.name,name);
 121         fstrcpy(servrec->serv.comment,comment);
 122         if (!strupper_m(servrec->serv.name)) {
 123                 DEBUG(2,("strupper_m %s failed\n", servrec->serv.name));
 124                 SAFE_FREE(servrec);
 125                 return NULL;
 126         }
 127         servrec->serv.type  = servertype;
 128
 129         update_server_ttl(servrec, ttl);
 130
 131         add_server_to_workgroup(work, servrec);
 132
 133         DEBUG(3,("create_server_on_workgroup: Created server entry %s of type %x (%s) on \
 134 workgroup %s.\n", name,servertype,comment, work->work_group));
 135
 136         return(servrec);
 137 }
 138
 139 /*******************************************************************
 140  Update the ttl field of a server record.
 141 *******************************************************************/
 142
 143 void update_server_ttl(struct server_record *servrec, int ttl)
 144 {
 145         if(ttl > lp_max_ttl())
 146                 ttl = lp_max_ttl();
 147
 148         if(is_myname(servrec->serv.name))
 149                 servrec->death_time = PERMANENT_TTL;
 150         else
 151                 servrec->death_time = (ttl != PERMANENT_TTL) ? time(NULL)+(ttl*3) : PERMANENT_TTL;
 152 }
 153
 154 /*******************************************************************
 155   Expire old servers in the serverlist. A time of -1 indicates
 156   everybody dies except those with a death_time of PERMANENT_TTL (which is 0).
 157   This should only be called from expire_workgroups_and_servers().
 158   ******************************************************************/
 159
 160 void expire_servers(struct work_record *work, time_t t)
 161 {
 162         struct server_record *servrec;
 163         struct server_record *nexts;
 164
 165         for (servrec = work->serverlist; servrec; servrec = nexts) {
 166                 nexts = servrec->next;
 167
 168                 if ((servrec->death_time != PERMANENT_TTL) && ((t == -1) || (servrec->death_time < t))) {
 169                         DEBUG(3,("expire_old_servers: Removing timed out server %s\n",servrec->serv.name));
 170                         remove_server_from_workgroup(work, servrec);
 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_t 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_t 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(FILE *fp, const char *name, uint32_t 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         fprintf(fp, "%-25s ", tmp);
 258         fprintf(fp, "%08x ", rec_type);
 259         slprintf(tmp, sizeof(tmp)-1, "\"%s\" ", local_master_browser_name);
 260         fprintf(fp, "%-30s", tmp);
 261         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_t stype;
 272         int i;
 273         int fd;
 274         FILE *fp;
 275         bool list_changed = force_write;
 276         static time_t lasttime = 0;
 277         TALLOC_CTX *ctx = talloc_tos();
 278         const struct loadparm_substitution *lp_sub =
 279                 loadparm_s3_global_substitution();
 280
 281         /* Always dump if we're being told to by a signal. */
 282         if(force_write == False) {
 283                 if (!lasttime)
 284                         lasttime = t;
 285                 if (t - lasttime < 5)
 286                         return;
 287         }
 288
 289         lasttime = t;
 290
 291         dump_workgroups(force_write);
 292
 293         for (subrec = FIRST_SUBNET; subrec ; subrec = NEXT_SUBNET_INCLUDING_UNICAST(subrec)) {
 294                 if(subrec->work_changed) {
 295                         list_changed = True;
 296                         break;
 297                 }
 298         }
 299
 300         if(!list_changed)
 301                 return;
 302
 303         updatecount++;
 304
 305         fname = cache_path(talloc_tos(), SERVER_LIST);
 306         if (!fname) {
 307                 return;
 308         }
 309         fnamenew = talloc_asprintf(ctx, "%s.",
 310                                 fname);
 311         if (!fnamenew) {
 312                 talloc_free(fname);
 313                 return;
 314         }
 315
 316         fd = open(fnamenew, O_WRONLY|O_CREAT|O_TRUNC, 0644);
 317         if (fd == -1) {
 318                 DBG_ERR("Can't open file %s: %s\n", fnamenew,
 319                         strerror(errno));
 320                 talloc_free(fnamenew);
 321                 talloc_free(fname);
 322                 return;
 323         }
 324
 325         fp = fdopen(fd, "w");
 326         if (!fp) {
 327                 DBG_ERR("fdopen failed: %s\n", strerror(errno));
 328                 close(fd);
 329                 talloc_free(fnamenew);
 330                 talloc_free(fname);
 331                 return;
 332         }
 333         fd = -1;
 334
 335         /*
 336          * Write out a record for our workgroup. Use the record from the first
 337          * subnet.
 338          */
 339
 340         if((work = find_workgroup_on_subnet(FIRST_SUBNET, lp_workgroup())) == NULL) {
 341                 DEBUG(0,("write_browse_list: Fatal error - cannot find my workgroup %s\n",
 342                         lp_workgroup()));
 343                 fclose(fp);
 344                 talloc_free(fnamenew);
 345                 talloc_free(fname);
 346                 return;
 347         }
 348
 349         write_browse_list_entry(fp, work->work_group,
 350                 SV_TYPE_DOMAIN_ENUM|SV_TYPE_NT|SV_TYPE_LOCAL_LIST_ONLY,
 351                 work->local_master_browser_name, work->work_group);
 352
 353         /*
 354          * We need to do something special for our own names.
 355          * This is due to the fact that we may be a local master browser on
 356          * one of our broadcast subnets, and a domain master on the unicast
 357          * subnet. We iterate over the subnets and only write out the name
 358          * once.
 359          */
 360
 361         for (i=0; my_netbios_names(i); i++) {
 362                 stype = 0;
 363                 for (subrec = FIRST_SUBNET; subrec ; subrec = NEXT_SUBNET_INCLUDING_UNICAST(subrec)) {
 364                         if((work = find_workgroup_on_subnet( subrec, lp_workgroup() )) == NULL)
 365                                 continue;
 366                         if((servrec = find_server_in_workgroup( work, my_netbios_names(i))) == NULL)
 367                                 continue;
 368
 369                         stype |= servrec->serv.type;
 370                 }
 371
 372                 /* Output server details, plus what workgroup they're in. */
 373                 write_browse_list_entry(fp, my_netbios_names(i), stype,
 374                         string_truncate(lp_server_string(talloc_tos(), lp_sub), MAX_SERVER_STRING_LENGTH), lp_workgroup());
 375         }
 376
 377         for (subrec = FIRST_SUBNET; subrec ; subrec = NEXT_SUBNET_INCLUDING_UNICAST(subrec)) {
 378                 subrec->work_changed = False;
 379
 380                 for (work = subrec->workgrouplist; work ; work = work->next) {
 381                         /* Write out a workgroup record for a workgroup. */
 382                         uint32_t wg_type = write_this_workgroup_name( subrec, work);
 383
 384                         if(wg_type) {
 385                                 write_browse_list_entry(fp, work->work_group, wg_type,
 386                                                 work->local_master_browser_name,
 387                                                 work->work_group);
 388                         }
 389
 390                         /* Now write out any server records a workgroup may have. */
 391
 392                         for (servrec = work->serverlist; servrec ; servrec = servrec->next) {
 393                                 uint32_t serv_type;
 394
 395                                 /* We have already written our names here. */
 396                                 if(is_myname(servrec->serv.name))
 397                                         continue;
 398
 399                                 serv_type = write_this_server_name(subrec, work, servrec);
 400                                 if(serv_type) {
 401                                         /* Output server details, plus what workgroup they're in. */
 402                                         write_browse_list_entry(fp, servrec->serv.name, serv_type,
 403                                                 servrec->serv.comment, work->work_group);
 404                                 }
 405                         }
 406                 }
 407         }
 408
 409         fclose(fp);
 410         unlink(fname);
 411         chmod(fnamenew,0644);
 412         rename(fnamenew,fname);
 413         DEBUG(3,("write_browse_list: Wrote browse list into file %s\n",fname));
 414         talloc_free(fnamenew);
 415         talloc_free(fname);
 416 }