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 ipgrp;
  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,
 144                         int search)
 145 {
 146         struct name_record *ret;
 147
 148         for (ret = n; ret; ret = ret->next)
 149         {
 150                 if (name_equal(&ret->name,name))
 151                 {
 152                         /* self search: self names only */
 153                         if ((search&FIND_SELF) == FIND_SELF &&
 154                             ret->source != SELF)
 155                                 continue;
 156
 157                         return ret;
 158                 }
 159         }
 160     return NULL;
 161 }
 162
 163
 164 /****************************************************************************
 165   find a name in the domain database namelist
 166   search can be any of:
 167   FIND_SELF - look exclusively for names the samba server has added for itself
 168   FIND_LOCAL - look for names in the local subnet record.
 169   FIND_WINS - look for names in the WINS record
 170   **************************************************************************/
 171 struct name_record *find_name_search(struct subnet_record **d,
 172                         struct nmb_name *name,
 173                         int search, struct in_addr ip)
 174 {
 175         if (d == NULL) return NULL; /* bad error! */
 176
 177     if (search & FIND_LOCAL) {
 178       if (*d != NULL) {
 179         struct name_record *n = find_name((*d)->namelist, name, search);
 180         DEBUG(4,("find_name on local: %s %s search %x\n",
 181                  namestr(name),inet_ntoa(ip), search));
 182         if (n) return n;
 183       }
 184     }
 185
 186     if (!(search & FIND_WINS)) return NULL;
 187
 188     /* find WINS subnet record. */
 189     *d = find_subnet(ipgrp);
 190
 191     if (*d == NULL) return NULL;
 192
 193     DEBUG(4,("find_name on WINS: %s %s search %x\n",
 194              namestr(name),inet_ntoa(ip), search));
 195     return find_name((*d)->namelist, name, search);
 196 }
 197
 198
 199 /****************************************************************************
 200   dump a copy of the name table
 201   **************************************************************************/
 202 void dump_names(void)
 203 {
 204   struct name_record *n;
 205   struct subnet_record *d;
 206   fstring fname, fnamenew;
 207   time_t t = time(NULL);
 208
 209   FILE *f;
 210
 211   strcpy(fname,lp_lockdir());
 212   trim_string(fname,NULL,"/");
 213   strcat(fname,"/");
 214   strcat(fname,WINS_LIST);
 215   strcpy(fnamenew,fname);
 216   strcat(fnamenew,".");
 217
 218   f = fopen(fnamenew,"w");
 219
 220   if (!f)
 221   {
 222     DEBUG(4,("Can't open %s - %s\n",fnamenew,strerror(errno)));
 223   }
 224
 225   DEBUG(3,("Dump of local name table:\n"));
 226
 227   for (d = subnetlist; d; d = d->next)
 228    for (n = d->namelist; n; n = n->next)
 229     {
 230       int i;
 231
 232           DEBUG(3,("%15s ", inet_ntoa(d->bcast_ip)));
 233           DEBUG(3,("%15s ", inet_ntoa(d->mask_ip)));
 234       DEBUG(3,("%-19s TTL=%ld ",
 235                namestr(&n->name),
 236                n->death_time?n->death_time-t:0));
 237
 238         for (i = 0; i < n->num_ips; i++)
 239         {
 240            DEBUG(3,("%15s NB=%2x source=%d",
 241                     inet_ntoa(n->ip_flgs[i].ip),
 242                     n->ip_flgs[i].nb_flags,n->source));
 243
 244         }
 245                 DEBUG(3,("\n"));
 246
 247       if (f && ip_equal(d->bcast_ip, ipgrp) && n->source == REGISTER)
 248       {
 249       /* XXXX i have little imagination as to how to output nb_flags as
 250          anything other than as a hexadecimal number :-) */
 251
 252         fprintf(f, "%s#%02x %ld ",
 253                n->name.name,n->name.name_type, /* XXXX ignore scope for now */
 254                n->death_time);
 255
 256         for (i = 0; i < n->num_ips; i++)
 257         {
 258            fprintf(f, "%s %2x ",
 259                                                 inet_ntoa(n->ip_flgs[i].ip),
 260                                                 n->ip_flgs[i].nb_flags);
 261         }
 262                 fprintf(f, "\n");
 263       }
 264
 265     }
 266
 267   fclose(f);
 268   unlink(fname);
 269   chmod(fnamenew,0644);
 270   rename(fnamenew,fname);
 271
 272   DEBUG(3,("Wrote wins database %s\n",fname));
 273 }
 274
 275
 276 /****************************************************************************
 277   load a netbios name database file
 278
 279   XXXX we cannot cope with loading Internet Group names, yet
 280   ****************************************************************************/
 281 void load_netbios_names(void)
 282 {
 283   struct subnet_record *d = find_subnet(ipgrp);
 284   fstring fname;
 285
 286   FILE *f;
 287   pstring line;
 288
 289   if (!d) return;
 290
 291   strcpy(fname,lp_lockdir());
 292   trim_string(fname,NULL,"/");
 293   strcat(fname,"/");
 294   strcat(fname,WINS_LIST);
 295
 296   f = fopen(fname,"r");
 297
 298   if (!f) {
 299     DEBUG(2,("Can't open wins database file %s\n",fname));
 300     return;
 301   }
 302
 303   while (!feof(f))
 304     {
 305       pstring name_str, ip_str, ttd_str, nb_flags_str;
 306
 307       pstring name;
 308       int type = 0;
 309       unsigned int nb_flags;
 310       time_t ttd;
 311           struct in_addr ipaddr;
 312
 313           enum name_source source;
 314
 315       char *ptr;
 316           int count = 0;
 317
 318       char *p;
 319
 320       if (!fgets_slash(line,sizeof(pstring),f)) continue;
 321
 322       if (*line == '#') continue;
 323
 324         ptr = line;
 325
 326         if (next_token(&ptr,name_str    ,NULL)) ++count;
 327         if (next_token(&ptr,ttd_str     ,NULL)) ++count;
 328         if (next_token(&ptr,ip_str      ,NULL)) ++count;
 329         if (next_token(&ptr,nb_flags_str,NULL)) ++count;
 330
 331         if (count <= 0) continue;
 332
 333         if (count != 4) {
 334           DEBUG(0,("Ill formed wins line"));
 335           DEBUG(0,("[%s]: name#type abs_time ip nb_flags\n",line));
 336           continue;
 337         }
 338
 339       /* netbios name. # divides the name from the type (hex): netbios#xx */
 340       strcpy(name,name_str);
 341
 342       p = strchr(name,'#');
 343
 344       if (p) {
 345             *p = 0;
 346             sscanf(p+1,"%x",&type);
 347       }
 348
 349       /* decode the netbios flags (hex) and the time-to-die (seconds) */
 350           sscanf(nb_flags_str,"%x",&nb_flags);
 351           sscanf(ttd_str,"%ld",&ttd);
 352
 353           ipaddr = *interpret_addr2(ip_str);
 354
 355       if (ip_equal(ipaddr,ipzero)) {
 356          source = SELF;
 357       }
 358       else
 359       {
 360          source = REGISTER;
 361       }
 362
 363       DEBUG(4, ("add WINS line: %s#%02x %ld %s %2x\n",
 364                name,type, ttd, inet_ntoa(ipaddr), nb_flags));
 365
 366       /* add all entries that have 60 seconds or more to live */
 367       if (ttd - 60 > time(NULL) || ttd == 0)
 368       {
 369         time_t t = (ttd?ttd-time(NULL):0) / 3;
 370
 371         /* add netbios entry read from the wins.dat file. IF it's ok */
 372         add_netbios_entry(d,name,type,nb_flags,t,source,ipaddr,True,True);
 373       }
 374     }
 375
 376   fclose(f);
 377 }
 378
 379
 380 /****************************************************************************
 381   remove an entry from the name list
 382   ****************************************************************************/
 383 void remove_netbios_name(struct subnet_record *d,
 384                         char *name,int type, enum name_source source,
 385                          struct in_addr ip)
 386 {
 387   struct nmb_name nn;
 388   struct name_record *n;
 389
 390   make_nmb_name(&nn, name, type, scope);
 391   n = find_name_search(&d, &nn, FIND_LOCAL, ip);
 392
 393   if (n && n->source == source) remove_name(d,n);
 394 }
 395
 396
 397 /****************************************************************************
 398   add an entry to the name list.
 399
 400   this is a multi-purpose function.
 401
 402   it adds samba's own names in to its records on each interface, keeping a
 403   record of whether it is a master browser, domain master, or WINS server.
 404
 405   it also keeps a record of WINS entries.
 406
 407   ****************************************************************************/
 408 struct name_record *add_netbios_entry(struct subnet_record *d,
 409                 char *name, int type, int nb_flags,
 410                 int ttl, enum name_source source, struct in_addr ip,
 411                 BOOL new_only,BOOL wins)
 412 {
 413   struct name_record *n;
 414   struct name_record *n2=NULL;
 415   int search = 0;
 416   BOOL self = source == SELF;
 417
 418   /* add the name to the WINS list if the name comes from a directed query */
 419   search |= wins ? FIND_WINS : FIND_LOCAL;
 420   /* search for SELF names only */
 421   search |= self ? FIND_SELF : 0;
 422
 423   if (!self)
 424   {
 425     if (!wins && type != 0x1b)
 426     {
 427        /* the only broadcast (non-WINS) names we are adding are ours
 428           (SELF) and Domain Master type names */
 429        return NULL;
 430     }
 431   }
 432
 433   n = (struct name_record *)malloc(sizeof(*n));
 434   if (!n) return(NULL);
 435
 436   bzero((char *)n,sizeof(*n));
 437
 438   n->num_ips = 1; /* XXXX ONLY USE THIS FUNCTION FOR ONE ENTRY */
 439   n->ip_flgs = (struct nmb_ip*)malloc(sizeof(*n->ip_flgs) * n->num_ips);
 440   if (!n->ip_flgs)
 441   {
 442      free(n);
 443      return NULL;
 444   }
 445
 446   make_nmb_name(&n->name,name,type,scope);
 447
 448   if ((n2 = find_name_search(&d, &n->name, search, new_only?ipzero:ip)))
 449   {
 450     free(n->ip_flgs);
 451     free(n);
 452     if (new_only || (n2->source==SELF && source!=SELF)) return n2;
 453     n = n2;
 454   }
 455
 456   if (ttl)
 457      n->death_time = time(NULL)+ttl*3;
 458   n->refresh_time = time(NULL)+GET_TTL(ttl);
 459
 460   /* XXXX only one entry expected with this function */
 461   n->ip_flgs[0].ip = ip;
 462   n->ip_flgs[0].nb_flags = nb_flags;
 463
 464   n->source = source;
 465
 466   if (!n2) add_name(d,n);
 467
 468   DEBUG(3,("Added netbios name %s at %s ttl=%d nb_flags=%2x\n",
 469                 namestr(&n->name),inet_ntoa(ip),ttl,nb_flags));
 470
 471   return(n);
 472 }
 473
 474
 475 /*******************************************************************
 476   expires old names in the namelist
 477   ******************************************************************/
 478 void expire_names(time_t t)
 479 {
 480         struct name_record *n;
 481         struct name_record *next;
 482         struct subnet_record *d;
 483
 484         /* expire old names */
 485         for (d = subnetlist; d; d = d->next)
 486         {
 487           for (n = d->namelist; n; n = next)
 488             {
 489               next = n->next;
 490               if (n->death_time && n->death_time < t)
 491                 {
 492                   if (n->source == SELF) {
 493                     DEBUG(3,("not expiring SELF name %s\n", namestr(&n->name)));
 494                     n->death_time += 300;
 495                     continue;
 496                   }
 497                   DEBUG(3,("Removing dead name %s\n", namestr(&n->name)));
 498
 499                   if (n->prev) n->prev->next = n->next;
 500                   if (n->next) n->next->prev = n->prev;
 501
 502                   if (d->namelist == n) d->namelist = n->next;
 503
 504                   free(n->ip_flgs);
 505                   free(n);
 506                 }
 507             }
 508         }
 509 }
 510
 511
 512 /***************************************************************************
 513   reply to a name query
 514   ****************************************************************************/
 515 struct name_record *search_for_name(struct subnet_record **d,
 516                                     struct nmb_name *question,
 517                                     struct in_addr ip, int Time, int search)
 518 {
 519   int name_type = question->name_type;
 520   char *qname = question->name;
 521   BOOL dns_type = (name_type == 0x20 || name_type == 0);
 522
 523   struct name_record *n;
 524
 525   DEBUG(3,("Search for %s from %s - ", namestr(question), inet_ntoa(ip)));
 526
 527   /* first look up name in cache */
 528   n = find_name_search(d,question,search,ip);
 529
 530   if (*d == NULL) return NULL;
 531
 532   /* now try DNS lookup. */
 533   if (!n)
 534     {
 535       struct in_addr dns_ip;
 536       uint32 a;
 537
 538       /* only do DNS lookups if the query is for type 0x20 or type 0x0 */
 539       if (!dns_type && name_type != 0x1b)
 540         {
 541           DEBUG(3,("types 0x20 0x1b 0x0 only: name not found\n"));
 542           return NULL;
 543         }
 544
 545       /* look it up with DNS */
 546       a = interpret_addr(qname);
 547
 548       putip((char *)&dns_ip,(char *)&a);
 549
 550       if (!a)
 551         {
 552           /* no luck with DNS. We could possibly recurse here XXXX */
 553           DEBUG(3,("no recursion.\n"));
 554       /* add the fail to our WINS cache of names. give it 1 hour in the cache */
 555           add_netbios_entry(*d,qname,name_type,NB_ACTIVE,60*60,DNSFAIL,dns_ip,
 556                                                 True, True);
 557           return NULL;
 558         }
 559
 560       /* add it to our WINS cache of names. give it 2 hours in the cache */
 561       n = add_netbios_entry(*d,qname,name_type,NB_ACTIVE,2*60*60,DNS,dns_ip,
 562                                                 True,True);
 563
 564       /* failed to add it? yikes! */
 565       if (!n) return NULL;
 566     }
 567
 568   /* is our entry already dead? */
 569   if (n->death_time)
 570     {
 571       if (n->death_time < Time) return False;
 572     }
 573
 574   /* it may have been an earlier failure */
 575   if (n->source == DNSFAIL)
 576     {
 577       DEBUG(3,("DNSFAIL\n"));
 578       return NULL;
 579     }
 580
 581   DEBUG(3,("OK %s\n",inet_ntoa(n->ip_flgs[0].ip)));
 582
 583   return n;
 584 }
 585
 586