source/namedbname.c

   1 /*
   2    Unix SMB/Netbios implementation.
   3    Version 1.9.
   4    NBT netbios routines and daemon - version 2
   5    Copyright (C) Andrew Tridgell 1994-1996
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 2 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program; if not, write to the Free Software
  19    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20
  21    Module name: namedbname.c
  22
  23    Revision History:
  24
  25    14 jan 96: lkcl@pires.co.uk
  26    added multiple workgroup domain master support
  27
  28    04 jul 96: lkcl@pires.co.uk
  29    created module namedbname containing name database functions
  30 */
  31
  32 #include "includes.h"
  33
  34 extern int DEBUGLEVEL;
  35
  36 extern pstring scope;
  37 extern struct in_addr ipzero;
  38 extern struct in_addr wins_ip;
  39
  40 extern struct subnet_record *subnetlist;
  41
  42 #define WINS_LIST "wins.dat"
  43
  44 uint16 nb_type = 0; /* samba's NetBIOS name type */
  45
  46
  47 /****************************************************************************
  48   samba's NetBIOS name type
  49
  50   XXXX maybe functionality could be set: B, M, P or H name registration
  51   and resolution could be set through nb_type. just a thought.
  52   ****************************************************************************/
  53 void set_samba_nb_type(void)
  54 {
  55         if (lp_wins_support() || (*lp_wins_server()))
  56         {
  57                 nb_type = NB_MFLAG; /* samba is a 'hybrid' node type */
  58         }
  59         else
  60         {
  61                 nb_type = NB_BFLAG; /* samba is broadcast-only node type */
  62         }
  63 }
  64
  65
  66 /****************************************************************************
  67   true if two netbios names are equal
  68 ****************************************************************************/
  69 BOOL name_equal(struct nmb_name *n1,struct nmb_name *n2)
  70 {
  71   return n1->name_type == n2->name_type &&
  72                  strequal(n1->name ,n2->name ) &&
  73          strequal(n1->scope,n2->scope);
  74 }
  75
  76
  77 /****************************************************************************
  78   true if the netbios name is ^1^2__MSBROWSE__^2^1
  79
  80   note: this name is registered if as a master browser or backup browser
  81   you are responsible for a workgroup (when you announce a domain by
  82   broadcasting on your local subnet, you announce it as coming from this
  83   name: see announce_host()).
  84
  85   **************************************************************************/
  86 BOOL ms_browser_name(char *name, int type)
  87 {
  88   return strequal(name,MSBROWSE) && type == 0x01;
  89 }
  90
  91
  92 /****************************************************************************
  93   add a netbios name into the namelist
  94   **************************************************************************/
  95 static void add_name(struct subnet_record *d, struct name_record *n)
  96 {
  97   struct name_record *n2;
  98
  99   if (!d) return;
 100
 101   if (!d->namelist)
 102   {
 103     d->namelist = n;
 104     n->prev = NULL;
 105     n->next = NULL;
 106     return;
 107   }
 108
 109   for (n2 = d->namelist; n2->next; n2 = n2->next) ;
 110
 111   n2->next = n;
 112   n->next = NULL;
 113   n->prev = n2;
 114 }
 115
 116
 117 /****************************************************************************
 118   remove a name from the namelist. The pointer must be an element just
 119   retrieved
 120   **************************************************************************/
 121 void remove_name(struct subnet_record *d, struct name_record *n)
 122 {
 123   struct name_record *nlist;
 124   if (!d) return;
 125
 126   nlist = d->namelist;
 127
 128   while (nlist && nlist != n) nlist = nlist->next;
 129
 130   if (nlist)
 131   {
 132     if (nlist->next) nlist->next->prev = nlist->prev;
 133     if (nlist->prev) nlist->prev->next = nlist->next;
 134     free(nlist);
 135   }
 136 }
 137
 138
 139 /****************************************************************************
 140   find a name in a namelist.
 141   **************************************************************************/
 142 struct name_record *find_name(struct name_record *n,
 143                         struct nmb_name *name, int search)
 144 {
 145         struct name_record *ret;
 146
 147         for (ret = n; ret; ret = ret->next)
 148         {
 149                 if (name_equal(&ret->name,name))
 150                 {
 151                         /* self search: self names only */
 152                         if ((search&FIND_SELF) == FIND_SELF && ret->source != SELF)
 153                         {
 154                                 continue;
 155                         }
 156                         DEBUG(9,("find_name: found name %s\n", name->name));
 157                         return ret;
 158                 }
 159         }
 160     DEBUG(9,("find_name: name %s NOT FOUND\n", name->name));
 161     return NULL;
 162 }
 163
 164
 165 /****************************************************************************
 166   find a name in the domain database namelist
 167   search can be any of:
 168   FIND_SELF - look exclusively for names the samba server has added for itself
 169   FIND_LOCAL - look for names in the local subnet record.
 170   FIND_WINS - look for names in the WINS record
 171   **************************************************************************/
 172 struct name_record *find_name_search(struct subnet_record **d,
 173                         struct nmb_name *name,
 174                         int search, struct in_addr ip)
 175 {
 176   if (d == NULL) return NULL; /* bad error! */
 177
 178   if (search & FIND_LOCAL) {
 179     if (*d != NULL) {
 180       struct name_record *n = find_name((*d)->namelist, name, search);
 181       DEBUG(4,("find_name on local: %s %s search %x\n",
 182                namestr(name),inet_ntoa(ip), search));
 183       if (n) return n;
 184     }
 185   }
 186
 187   if (!(search & FIND_WINS)) return NULL;
 188
 189   /* find WINS subnet record. */
 190   *d = find_subnet(wins_ip);
 191
 192   if (*d == NULL) return NULL;
 193
 194   DEBUG(4,("find_name on WINS: %s %s search %x\n",
 195            namestr(name),inet_ntoa(ip), search));
 196   return find_name((*d)->namelist, name, search);
 197 }
 198
 199
 200 /****************************************************************************
 201   dump a copy of the name table
 202   **************************************************************************/
 203 void dump_names(void)
 204 {
 205   struct name_record *n;
 206   struct subnet_record *d;
 207   fstring fname, fnamenew;
 208   time_t t = time(NULL);
 209
 210   FILE *f;
 211
 212   strcpy(fname,lp_lockdir());
 213   trim_string(fname,NULL,"/");
 214   strcat(fname,"/");
 215   strcat(fname,WINS_LIST);
 216   strcpy(fnamenew,fname);
 217   strcat(fnamenew,".");
 218
 219   f = fopen(fnamenew,"w");
 220
 221   if (!f)
 222   {
 223     DEBUG(3,("Can't open %s - %s\n",fnamenew,strerror(errno)));
 224     return;
 225   }
 226
 227   DEBUG(4,("Dump of local name table:\n"));
 228
 229   for (d = subnetlist; d; d = d->next)
 230    for (n = d->namelist; n; n = n->next)
 231     {
 232       int i;
 233
 234           DEBUG(4,("%15s ", inet_ntoa(d->bcast_ip)));
 235           DEBUG(4,("%15s ", inet_ntoa(d->mask_ip)));
 236       DEBUG(4,("%-19s TTL=%ld ",
 237                namestr(&n->name),
 238                n->death_time?n->death_time-t:0));
 239
 240         for (i = 0; i < n->num_ips; i++)
 241         {
 242            DEBUG(4,("%15s NB=%2x source=%d",
 243                     inet_ntoa(n->ip_flgs[i].ip),
 244                     n->ip_flgs[i].nb_flags,n->source));
 245
 246         }
 247                 DEBUG(4,("\n"));
 248
 249       if (f && ip_equal(d->bcast_ip, wins_ip) && n->source == REGISTER)
 250       {
 251       /* XXXX i have little imagination as to how to output nb_flags as
 252          anything other than as a hexadecimal number :-) */
 253
 254         fprintf(f, "%s#%02x %ld ",
 255                n->name.name,n->name.name_type, /* XXXX ignore scope for now */
 256                n->death_time);
 257
 258         for (i = 0; i < n->num_ips; i++)
 259         {
 260            fprintf(f, "%s %2x ",
 261                                                 inet_ntoa(n->ip_flgs[i].ip),
 262                                                 n->ip_flgs[i].nb_flags);
 263         }
 264                 fprintf(f, "\n");
 265       }
 266
 267     }
 268
 269   fclose(f);
 270   unlink(fname);
 271   chmod(fnamenew,0644);
 272   rename(fnamenew,fname);
 273
 274   DEBUG(3,("Wrote wins database %s\n",fname));
 275 }
 276
 277
 278 /****************************************************************************
 279   load a netbios name database file
 280
 281   XXXX we cannot cope with loading Internet Group names, yet
 282   ****************************************************************************/
 283 void load_netbios_names(void)
 284 {
 285   struct subnet_record *d = find_subnet(wins_ip);
 286   fstring fname;
 287
 288   FILE *f;
 289   pstring line;
 290
 291   if (!d) return;
 292
 293   strcpy(fname,lp_lockdir());
 294   trim_string(fname,NULL,"/");
 295   strcat(fname,"/");
 296   strcat(fname,WINS_LIST);
 297
 298   f = fopen(fname,"r");
 299
 300   if (!f) {
 301     DEBUG(2,("Can't open wins database file %s\n",fname));
 302     return;
 303   }
 304
 305   while (!feof(f))
 306     {
 307       pstring name_str, ip_str, ttd_str, nb_flags_str;
 308
 309       pstring name;
 310       int type = 0;
 311       unsigned int nb_flags;
 312       time_t ttd;
 313           struct in_addr ipaddr;
 314
 315           enum name_source source;
 316
 317       char *ptr;
 318           int count = 0;
 319
 320       char *p;
 321
 322       if (!fgets_slash(line,sizeof(pstring),f)) continue;
 323
 324       if (*line == '#') continue;
 325
 326         ptr = line;
 327
 328         if (next_token(&ptr,name_str    ,NULL)) ++count;
 329         if (next_token(&ptr,ttd_str     ,NULL)) ++count;
 330         if (next_token(&ptr,ip_str      ,NULL)) ++count;
 331         if (next_token(&ptr,nb_flags_str,NULL)) ++count;
 332
 333         if (count <= 0) continue;
 334
 335         if (count != 4) {
 336           DEBUG(0,("Ill formed wins line"));
 337           DEBUG(0,("[%s]: name#type abs_time ip nb_flags\n",line));
 338           continue;
 339         }
 340
 341       /* netbios name. # divides the name from the type (hex): netbios#xx */
 342       strcpy(name,name_str);
 343
 344       p = strchr(name,'#');
 345
 346       if (p) {
 347             *p = 0;
 348             sscanf(p+1,"%x",&type);
 349       }
 350
 351       /* decode the netbios flags (hex) and the time-to-die (seconds) */
 352           sscanf(nb_flags_str,"%x",&nb_flags);
 353           sscanf(ttd_str,"%ld",&ttd);
 354
 355           ipaddr = *interpret_addr2(ip_str);
 356
 357       if (ip_equal(ipaddr,ipzero)) {
 358          source = SELF;
 359       }
 360       else
 361       {
 362          source = REGISTER;
 363       }
 364
 365       DEBUG(4, ("add WINS line: %s#%02x %ld %s %2x\n",
 366                name,type, ttd, inet_ntoa(ipaddr), nb_flags));
 367
 368       /* add all entries that have 60 seconds or more to live */
 369       if (ttd - 60 > time(NULL) || ttd == 0)
 370       {
 371         time_t t = (ttd?ttd-time(NULL):0) / 3;
 372
 373         /* add netbios entry read from the wins.dat file. IF it's ok */
 374         add_netbios_entry(d,name,type,nb_flags,t,source,ipaddr,True,True);
 375       }
 376     }
 377
 378   fclose(f);
 379 }
 380
 381
 382 /****************************************************************************
 383   remove an entry from the name list
 384   ****************************************************************************/
 385 void remove_netbios_name(struct subnet_record *d,
 386                         char *name,int type, enum name_source source,
 387                          struct in_addr ip)
 388 {
 389   struct nmb_name nn;
 390   struct name_record *n;
 391
 392   make_nmb_name(&nn, name, type, scope);
 393   n = find_name_search(&d, &nn, FIND_LOCAL, ip);
 394
 395   if (n && n->source == source) remove_name(d,n);
 396 }
 397
 398
 399 /****************************************************************************
 400   add an entry to the name list.
 401
 402   this is a multi-purpose function.
 403
 404   it adds samba's own names in to its records on each interface, keeping a
 405   record of whether it is a master browser, domain master, or WINS server.
 406
 407   it also keeps a record of WINS entries.
 408
 409   ****************************************************************************/
 410 struct name_record *add_netbios_entry(struct subnet_record *d,
 411                 char *name, int type, int nb_flags,
 412                 int ttl, enum name_source source, struct in_addr ip,
 413                 BOOL new_only,BOOL wins)
 414 {
 415   struct name_record *n;
 416   struct name_record *n2=NULL;
 417   int search = 0;
 418   BOOL self = source == SELF;
 419
 420   /* add the name to the WINS list if the name comes from a directed query */
 421   search |= wins ? FIND_WINS : FIND_LOCAL;
 422   /* search for SELF names only */
 423   search |= self ? FIND_SELF : 0;
 424
 425   if (!self)
 426   {
 427     if (!wins && type != 0x1b)
 428     {
 429        /* the only broadcast (non-WINS) names we are adding are ours
 430           (SELF) and Domain Master type names */
 431        return NULL;
 432     }
 433   }
 434
 435   n = (struct name_record *)malloc(sizeof(*n));
 436   if (!n) return(NULL);
 437
 438   bzero((char *)n,sizeof(*n));
 439
 440   n->num_ips = 1; /* XXXX ONLY USE THIS FUNCTION FOR ONE ENTRY */
 441   n->ip_flgs = (struct nmb_ip*)malloc(sizeof(*n->ip_flgs) * n->num_ips);
 442   if (!n->ip_flgs)
 443   {
 444      free(n);
 445      return NULL;
 446   }
 447
 448   make_nmb_name(&n->name,name,type,scope);
 449
 450   if ((n2 = find_name_search(&d, &n->name, search, new_only?ipzero:ip)))
 451   {
 452     free(n->ip_flgs);
 453     free(n);
 454     if (new_only || (n2->source==SELF && source!=SELF)) return n2;
 455     n = n2;
 456   }
 457
 458   if (ttl)
 459      n->death_time = time(NULL)+ttl*3;
 460   n->refresh_time = time(NULL)+GET_TTL(ttl);
 461
 462   /* XXXX only one entry expected with this function */
 463   n->ip_flgs[0].ip = ip;
 464   n->ip_flgs[0].nb_flags = nb_flags;
 465
 466   n->source = source;
 467
 468   if (!n2) add_name(d,n);
 469
 470   DEBUG(3,("Added netbios name %s at %s ttl=%d nb_flags=%2x to interface %s\n",
 471            namestr(&n->name),inet_ntoa(ip),ttl,nb_flags,
 472            ip_equal(d->bcast_ip, wins_ip) ? "WINS" : inet_ntoa(d->bcast_ip)));
 473
 474   return(n);
 475 }
 476
 477
 478 /*******************************************************************
 479   expires old names in the namelist
 480   ******************************************************************/
 481 void expire_names(time_t t)
 482 {
 483         struct name_record *n;
 484         struct name_record *next;
 485         struct subnet_record *d;
 486
 487         /* expire old names */
 488         for (d = subnetlist; d; d = d->next)
 489         {
 490           for (n = d->namelist; n; n = next)
 491             {
 492               next = n->next;
 493               if (n->death_time && n->death_time < t)
 494                 {
 495                   if (n->source == SELF) {
 496                     DEBUG(3,("not expiring SELF name %s\n", namestr(&n->name)));
 497                     n->death_time += 300;
 498                     continue;
 499                   }
 500                   DEBUG(3,("Removing dead name %s\n", namestr(&n->name)));
 501
 502                   if (n->prev) n->prev->next = n->next;
 503                   if (n->next) n->next->prev = n->prev;
 504
 505                   if (d->namelist == n) d->namelist = n->next;
 506
 507                   free(n->ip_flgs);
 508                   free(n);
 509                 }
 510             }
 511         }
 512 }
 513
 514
 515 /***************************************************************************
 516   assume a WINS name is a dns name, and do a gethostbyname() on it.
 517   ****************************************************************************/
 518 struct name_record *dns_name_search(struct nmb_name *question, int Time)
 519 {
 520         int name_type = question->name_type;
 521         char *qname = question->name;
 522         char *r;
 523         BOOL dns_type = (name_type == 0x20 || name_type == 0);
 524         struct in_addr dns_ip;
 525         struct subnet_record *d = find_subnet(wins_ip);
 526
 527         if (d == NULL) return NULL;
 528
 529         DEBUG(3,("Search for %s - ", namestr(question)));
 530
 531         /* only do DNS lookups if the query is for type 0x20 or type 0x0 */
 532         if (!dns_type)
 533         {
 534                 DEBUG(3,("types 0x20 0x0 only: name not found\n"));
 535                 return NULL;
 536         }
 537
 538         /* look it up with DNS */
 539         dns_ip.s_addr = interpret_addr(qname);
 540
 541         if (!dns_ip.s_addr)
 542         {
 543                 /* no luck with DNS. We could possibly recurse here XXXX */
 544                 DEBUG(3,("not found. no recursion.\n"));
 545                 /* add the fail to WINS cache of names. give it 1 hour in the cache */
 546                 add_netbios_entry(d,qname,name_type,NB_ACTIVE,60*60,DNSFAIL,dns_ip,
 547                                   True, True);
 548                 return NULL;
 549         }
 550
 551         DEBUG(3,("found with DNS: %s\n", inet_ntoa(dns_ip)));
 552
 553         /* add it to our WINS cache of names. give it 2 hours in the cache */
 554         return add_netbios_entry(d,qname,name_type,NB_ACTIVE,2*60*60,DNS,dns_ip,
 555                                  True,True);
 556 }