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 #include "lib/util/string_wrappers.h"
  28
  29 int updatecount = 0;
  30
  31 /*******************************************************************
  32   Remove all the servers in a work group.
  33   ******************************************************************/
  34
  35 void remove_all_servers(struct work_record *work)
  36 {
  37         struct server_record *servrec;
  38         struct server_record *nexts;
  39
  40         for (servrec = work->serverlist; servrec; servrec = nexts) {
  41                 DEBUG(7,("remove_all_servers: Removing server %s\n",servrec->serv.name));
  42                 nexts = servrec->next;
  43                 DLIST_REMOVE(work->serverlist, servrec);
  44                 ZERO_STRUCTP(servrec);
  45                 SAFE_FREE(servrec);
  46         }
  47
  48         work->subnet->work_changed = True;
  49 }
  50
  51 /***************************************************************************
  52   Add a server into a workgroup serverlist.
  53   **************************************************************************/
  54
  55 static void add_server_to_workgroup(struct work_record *work,
  56                              struct server_record *servrec)
  57 {
  58         DLIST_ADD_END(work->serverlist, servrec);
  59         work->subnet->work_changed = True;
  60 }
  61
  62 /****************************************************************************
  63   Find a server in a server list.
  64   **************************************************************************/
  65
  66 struct server_record *find_server_in_workgroup(struct work_record *work, const char *name)
  67 {
  68         struct server_record *ret;
  69
  70         for (ret = work->serverlist; ret; ret = ret->next) {
  71                 if (strequal(ret->serv.name,name))
  72                         return ret;
  73         }
  74         return NULL;
  75 }
  76
  77
  78 /****************************************************************************
  79   Remove a server entry from this workgroup.
  80   ****************************************************************************/
  81
  82 void remove_server_from_workgroup(struct work_record *work, struct server_record *servrec)
  83 {
  84         DLIST_REMOVE(work->serverlist, servrec);
  85         ZERO_STRUCTP(servrec);
  86         SAFE_FREE(servrec);
  87         work->subnet->work_changed = True;
  88 }
  89
  90 /****************************************************************************
  91   Create a server entry on this workgroup.
  92   ****************************************************************************/
  93
  94 struct server_record *create_server_on_workgroup(struct work_record *work,
  95                                                  const char *name,int servertype,
  96                                                  int ttl, const char *comment)
  97 {
  98         struct server_record *servrec;
  99
 100         if (name[0] == '*') {
 101                 DEBUG(7,("create_server_on_workgroup: not adding name starting with '*' (%s)\n",
 102                         name));
 103                 return (NULL);
 104         }
 105
 106         if(find_server_in_workgroup(work, name) != NULL) {
 107                 DEBUG(0,("create_server_on_workgroup: Server %s already exists on \
 108 workgroup %s. This is a bug.\n", name, work->work_group));
 109                 return NULL;
 110         }
 111
 112         if((servrec = SMB_MALLOC_P(struct server_record)) == NULL) {
 113                 DEBUG(0,("create_server_entry_on_workgroup: malloc fail !\n"));
 114                 return NULL;
 115         }
 116
 117         memset((char *)servrec,'\0',sizeof(*servrec));
 118
 119         servrec->subnet = work->subnet;
 120
 121         fstrcpy(servrec->serv.name,name);
 122         fstrcpy(servrec->serv.comment,comment);
 123         if (!strupper_m(servrec->serv.name)) {
 124                 DEBUG(2,("strupper_m %s failed\n", servrec->serv.name));
 125                 SAFE_FREE(servrec);
 126                 return NULL;
 127         }
 128         servrec->serv.type  = servertype;
 129
 130         update_server_ttl(servrec, ttl);
 131
 132         add_server_to_workgroup(work, servrec);
 133
 134         DEBUG(3,("create_server_on_workgroup: Created server entry %s of type %x (%s) on \
 135 workgroup %s.\n", name,servertype,comment, work->work_group));
 136
 137         return(servrec);
 138 }
 139
 140 /*******************************************************************
 141  Update the ttl field of a server record.
 142 *******************************************************************/
 143
 144 void update_server_ttl(struct server_record *servrec, int ttl)
 145 {
 146         if(ttl > lp_max_ttl())
 147                 ttl = lp_max_ttl();
 148
 149         if(is_myname(servrec->serv.name))
 150                 servrec->death_time = PERMANENT_TTL;
 151         else
 152                 servrec->death_time = (ttl != PERMANENT_TTL) ? time(NULL)+(ttl*3) : PERMANENT_TTL;
 153 }
 154
 155 /*******************************************************************
 156   Expire old servers in the serverlist. A time of -1 indicates
 157   everybody dies except those with a death_time of PERMANENT_TTL (which is 0).
 158   This should only be called from expire_workgroups_and_servers().
 159   ******************************************************************/
 160
 161 void expire_servers(struct work_record *work, time_t t)
 162 {
 163         struct server_record *servrec;
 164         struct server_record *nexts;
 165
 166         for (servrec = work->serverlist; servrec; servrec = nexts) {
 167                 nexts = servrec->next;
 168
 169                 if ((servrec->death_time != PERMANENT_TTL) && ((t == -1) || (servrec->death_time < t))) {
 170                         DEBUG(3,("expire_old_servers: Removing timed out server %s\n",servrec->serv.name));
 171                         remove_server_from_workgroup(work, servrec);
 172                 }
 173         }
 174 }
 175
 176 /*******************************************************************
 177  Decide if we should write out a server record for this server.
 178  We return zero if we should not. Check if we've already written
 179  out this server record from an earlier subnet.
 180 ******************************************************************/
 181
 182 static uint32_t write_this_server_name( struct subnet_record *subrec,
 183                                       struct work_record *work,
 184                                       struct server_record *servrec)
 185 {
 186         struct subnet_record *ssub;
 187         struct work_record *iwork;
 188
 189         /* Go through all the subnets we have already seen. */
 190         for (ssub = FIRST_SUBNET; ssub && (ssub != subrec); ssub = NEXT_SUBNET_INCLUDING_UNICAST(ssub)) {
 191                 for(iwork = ssub->workgrouplist; iwork; iwork = iwork->next) {
 192                         if(find_server_in_workgroup( iwork, servrec->serv.name) != NULL) {
 193                                 /*
 194                                  * We have already written out this server record, don't
 195                                  * do it again. This gives precedence to servers we have seen
 196                                  * on the broadcast subnets over servers that may have been
 197                                  * added via a sync on the unicast_subet.
 198                                  *
 199                                  * The correct way to do this is to have a serverlist file
 200                                  * per subnet - this means changes to smbd as well. I may
 201                                  * add this at a later date (JRA).
 202                                  */
 203
 204                                 return 0;
 205                         }
 206                 }
 207         }
 208
 209         return servrec->serv.type;
 210 }
 211
 212 /*******************************************************************
 213  Decide if we should write out a workgroup record for this workgroup.
 214  We return zero if we should not. Don't write out lp_workgroup() (we've
 215  already done it) and also don't write out a second workgroup record
 216  on the unicast subnet that we've already written out on one of the
 217  broadcast subnets.
 218 ******************************************************************/
 219
 220 static uint32_t write_this_workgroup_name( struct subnet_record *subrec,
 221                                          struct work_record *work)
 222 {
 223         struct subnet_record *ssub;
 224
 225         if(strequal(lp_workgroup(), work->work_group))
 226                 return 0;
 227
 228         /* This is a workgroup we have seen on a broadcast subnet. All
 229                 these have the same type. */
 230
 231         if(subrec != unicast_subnet)
 232                 return (SV_TYPE_DOMAIN_ENUM|SV_TYPE_NT|SV_TYPE_LOCAL_LIST_ONLY);
 233
 234         for(ssub = FIRST_SUBNET; ssub;  ssub = NEXT_SUBNET_EXCLUDING_UNICAST(ssub)) {
 235                 /* This is the unicast subnet so check if we've already written out
 236                         this subnet when we passed over the broadcast subnets. */
 237
 238                 if(find_workgroup_on_subnet( ssub, work->work_group) != NULL)
 239                         return 0;
 240         }
 241
 242         /* All workgroups on the unicast subnet (except our own, which we
 243                 have already written out) cannot be local. */
 244
 245         return (SV_TYPE_DOMAIN_ENUM|SV_TYPE_NT);
 246 }
 247
 248 /*******************************************************************
 249   Write out the browse.dat file.
 250   ******************************************************************/
 251
 252 void write_browse_list_entry(FILE *fp, const char *name, uint32_t rec_type,
 253                 const char *local_master_browser_name, const char *description)
 254 {
 255         fstring tmp;
 256
 257         slprintf(tmp,sizeof(tmp)-1, "\"%s\"", name);
 258         fprintf(fp, "%-25s ", tmp);
 259         fprintf(fp, "%08x ", rec_type);
 260         slprintf(tmp, sizeof(tmp)-1, "\"%s\" ", local_master_browser_name);
 261         fprintf(fp, "%-30s", tmp);
 262         fprintf(fp, "\"%s\"\n", description);
 263 }
 264
 265 void write_browse_list(time_t t, bool force_write)
 266 {
 267         struct subnet_record *subrec;
 268         struct work_record *work;
 269         struct server_record *servrec;
 270         char *fname;
 271         char *fnamenew;
 272         uint32_t stype;
 273         int i;
 274         int fd;
 275         FILE *fp;
 276         bool list_changed = force_write;
 277         static time_t lasttime = 0;
 278         TALLOC_CTX *ctx = talloc_tos();
 279         const struct loadparm_substitution *lp_sub =
 280                 loadparm_s3_global_substitution();
 281
 282         /* Always dump if we're being told to by a signal. */
 283         if(force_write == False) {
 284                 if (!lasttime)
 285                         lasttime = t;
 286                 if (t - lasttime < 5)
 287                         return;
 288         }
 289
 290         lasttime = t;
 291
 292         dump_workgroups(force_write);
 293
 294         for (subrec = FIRST_SUBNET; subrec ; subrec = NEXT_SUBNET_INCLUDING_UNICAST(subrec)) {
 295                 if(subrec->work_changed) {
 296                         list_changed = True;
 297                         break;
 298                 }
 299         }
 300
 301         if(!list_changed)
 302                 return;
 303
 304         updatecount++;
 305
 306         fname = cache_path(talloc_tos(), SERVER_LIST);
 307         if (!fname) {
 308                 return;
 309         }
 310         fnamenew = talloc_asprintf(ctx, "%s.",
 311                                 fname);
 312         if (!fnamenew) {
 313                 talloc_free(fname);
 314                 return;
 315         }
 316
 317         fd = open(fnamenew, O_WRONLY|O_CREAT|O_TRUNC, 0644);
 318         if (fd == -1) {
 319                 DBG_ERR("Can't open file %s: %s\n", fnamenew,
 320                         strerror(errno));
 321                 talloc_free(fnamenew);
 322                 talloc_free(fname);
 323                 return;
 324         }
 325
 326         fp = fdopen(fd, "w");
 327         if (!fp) {
 328                 DBG_ERR("fdopen failed: %s\n", strerror(errno));
 329                 close(fd);
 330                 talloc_free(fnamenew);
 331                 talloc_free(fname);
 332                 return;
 333         }
 334         fd = -1;
 335
 336         /*
 337          * Write out a record for our workgroup. Use the record from the first
 338          * subnet.
 339          */
 340
 341         if((work = find_workgroup_on_subnet(FIRST_SUBNET, lp_workgroup())) == NULL) {
 342                 DEBUG(0,("write_browse_list: Fatal error - cannot find my workgroup %s\n",
 343                         lp_workgroup()));
 344                 fclose(fp);
 345                 talloc_free(fnamenew);
 346                 talloc_free(fname);
 347                 return;
 348         }
 349
 350         write_browse_list_entry(fp, work->work_group,
 351                 SV_TYPE_DOMAIN_ENUM|SV_TYPE_NT|SV_TYPE_LOCAL_LIST_ONLY,
 352                 work->local_master_browser_name, work->work_group);
 353
 354         /*
 355          * We need to do something special for our own names.
 356          * This is due to the fact that we may be a local master browser on
 357          * one of our broadcast subnets, and a domain master on the unicast
 358          * subnet. We iterate over the subnets and only write out the name
 359          * once.
 360          */
 361
 362         for (i=0; my_netbios_names(i); i++) {
 363                 stype = 0;
 364                 for (subrec = FIRST_SUBNET; subrec ; subrec = NEXT_SUBNET_INCLUDING_UNICAST(subrec)) {
 365                         if((work = find_workgroup_on_subnet( subrec, lp_workgroup() )) == NULL)
 366                                 continue;
 367                         if((servrec = find_server_in_workgroup( work, my_netbios_names(i))) == NULL)
 368                                 continue;
 369
 370                         stype |= servrec->serv.type;
 371                 }
 372
 373                 /* Output server details, plus what workgroup they're in. */
 374                 write_browse_list_entry(fp, my_netbios_names(i), stype,
 375                         string_truncate(lp_server_string(talloc_tos(), lp_sub), MAX_SERVER_STRING_LENGTH), lp_workgroup());
 376         }
 377
 378         for (subrec = FIRST_SUBNET; subrec ; subrec = NEXT_SUBNET_INCLUDING_UNICAST(subrec)) {
 379                 subrec->work_changed = False;
 380
 381                 for (work = subrec->workgrouplist; work ; work = work->next) {
 382                         /* Write out a workgroup record for a workgroup. */
 383                         uint32_t wg_type = write_this_workgroup_name( subrec, work);
 384
 385                         if(wg_type) {
 386                                 write_browse_list_entry(fp, work->work_group, wg_type,
 387                                                 work->local_master_browser_name,
 388                                                 work->work_group);
 389                         }
 390
 391                         /* Now write out any server records a workgroup may have. */
 392
 393                         for (servrec = work->serverlist; servrec ; servrec = servrec->next) {
 394                                 uint32_t serv_type;
 395
 396                                 /* We have already written our names here. */
 397                                 if(is_myname(servrec->serv.name))
 398                                         continue;
 399
 400                                 serv_type = write_this_server_name(subrec, work, servrec);
 401                                 if(serv_type) {
 402                                         /* Output server details, plus what workgroup they're in. */
 403                                         write_browse_list_entry(fp, servrec->serv.name, serv_type,
 404                                                 servrec->serv.comment, work->work_group);
 405                                 }
 406                         }
 407                 }
 408         }
 409
 410         fclose(fp);
 411         unlink(fname);
 412         chmod(fnamenew,0644);
 413         rename(fnamenew,fname);
 414         DEBUG(3,("write_browse_list: Wrote browse list into file %s\n",fname));
 415         talloc_free(fnamenew);
 416         talloc_free(fname);
 417 }