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 1994-1997
   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 = wins_subnet;
 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   fstring fname, fnamenew;
 207   time_t t = time(NULL);
 208
 209   FILE *f;
 210
 211   if(lp_wins_support() == False || wins_subnet == 0)
 212     return;
 213
 214   strcpy(fname,lp_lockdir());
 215   trim_string(fname,NULL,"/");
 216   strcat(fname,"/");
 217   strcat(fname,WINS_LIST);
 218   strcpy(fnamenew,fname);
 219   strcat(fnamenew,".");
 220
 221   f = fopen(fnamenew,"w");
 222
 223   if (!f)
 224   {
 225     DEBUG(3,("Can't open %s - %s\n",fnamenew,strerror(errno)));
 226     return;
 227   }
 228
 229   DEBUG(4,("Dump of WINS name table:\n"));
 230
 231   for (n = wins_subnet->namelist; n; n = n->next)
 232    {
 233      int i;
 234
 235      DEBUG(4,("%15s ", inet_ntoa(wins_subnet->bcast_ip)));
 236      DEBUG(4,("%15s ", inet_ntoa(wins_subnet->mask_ip)));
 237      DEBUG(4,("%-19s TTL=%ld ",
 238                namestr(&n->name),
 239                n->death_time?n->death_time-t:0));
 240
 241      for (i = 0; i < n->num_ips; i++)
 242       {
 243         DEBUG(4,("%15s NB=%2x source=%d",
 244                  inet_ntoa(n->ip_flgs[i].ip),
 245                     n->ip_flgs[i].nb_flags,n->source));
 246
 247       }
 248      DEBUG(4,("\n"));
 249
 250      if (f && n->source == REGISTER)
 251       {
 252       /* XXXX i have little imagination as to how to output nb_flags as
 253          anything other than as a hexadecimal number :-) */
 254
 255         fprintf(f, "%s#%02x %ld ",
 256                n->name.name,n->name.name_type, /* XXXX ignore scope for now */
 257                n->death_time);
 258
 259         for (i = 0; i < n->num_ips; i++)
 260         {
 261            fprintf(f, "%s %2x ",
 262                                                 inet_ntoa(n->ip_flgs[i].ip),
 263                                                 n->ip_flgs[i].nb_flags);
 264         }
 265                 fprintf(f, "\n");
 266       }
 267
 268   }
 269
 270   fclose(f);
 271   unlink(fname);
 272   chmod(fnamenew,0644);
 273   rename(fnamenew,fname);
 274
 275   DEBUG(3,("Wrote wins database %s\n",fname));
 276 }
 277
 278
 279 /****************************************************************************
 280   load a netbios name database file
 281
 282   XXXX we cannot cope with loading Internet Group names, yet
 283   ****************************************************************************/
 284 void load_netbios_names(void)
 285 {
 286   struct subnet_record *d = wins_subnet;
 287   fstring fname;
 288
 289   FILE *f;
 290   pstring line;
 291
 292   if (!d) return;
 293
 294   strcpy(fname,lp_lockdir());
 295   trim_string(fname,NULL,"/");
 296   strcat(fname,"/");
 297   strcat(fname,WINS_LIST);
 298
 299   f = fopen(fname,"r");
 300
 301   if (!f) {
 302     DEBUG(2,("Can't open wins database file %s\n",fname));
 303     return;
 304   }
 305
 306   while (!feof(f))
 307     {
 308       pstring name_str, ip_str, ttd_str, nb_flags_str;
 309
 310       pstring name;
 311       int type = 0;
 312       unsigned int nb_flags;
 313       time_t ttd;
 314           struct in_addr ipaddr;
 315
 316           enum name_source source;
 317
 318       char *ptr;
 319           int count = 0;
 320
 321       char *p;
 322
 323       if (!fgets_slash(line,sizeof(pstring),f)) continue;
 324
 325       if (*line == '#') continue;
 326
 327         ptr = line;
 328
 329         if (next_token(&ptr,name_str    ,NULL)) ++count;
 330         if (next_token(&ptr,ttd_str     ,NULL)) ++count;
 331         if (next_token(&ptr,ip_str      ,NULL)) ++count;
 332         if (next_token(&ptr,nb_flags_str,NULL)) ++count;
 333
 334         if (count <= 0) continue;
 335
 336         if (count != 4) {
 337           DEBUG(0,("Ill formed wins line"));
 338           DEBUG(0,("[%s]: name#type abs_time ip nb_flags\n",line));
 339           continue;
 340         }
 341
 342       /* netbios name. # divides the name from the type (hex): netbios#xx */
 343       strcpy(name,name_str);
 344
 345       p = strchr(name,'#');
 346
 347       if (p) {
 348             *p = 0;
 349             sscanf(p+1,"%x",&type);
 350       }
 351
 352       /* decode the netbios flags (hex) and the time-to-die (seconds) */
 353           sscanf(nb_flags_str,"%x",&nb_flags);
 354           sscanf(ttd_str,"%ld",&ttd);
 355
 356           ipaddr = *interpret_addr2(ip_str);
 357
 358       if (ip_equal(ipaddr,ipzero)) {
 359          source = SELF;
 360       }
 361       else
 362       {
 363          source = REGISTER;
 364       }
 365
 366       DEBUG(4, ("add WINS line: %s#%02x %ld %s %2x\n",
 367                name,type, ttd, inet_ntoa(ipaddr), nb_flags));
 368
 369       /* add all entries that have 60 seconds or more to live */
 370       if (ttd - 60 > time(NULL) || ttd == 0)
 371       {
 372         time_t t = (ttd?ttd-time(NULL):0) / 3;
 373
 374         /* add netbios entry read from the wins.dat file. IF it's ok */
 375         add_netbios_entry(d,name,type,nb_flags,t,source,ipaddr,True,True);
 376       }
 377     }
 378
 379   fclose(f);
 380 }
 381
 382
 383 /****************************************************************************
 384   remove an entry from the name list
 385   ****************************************************************************/
 386 void remove_netbios_name(struct subnet_record *d,
 387                         char *name,int type, enum name_source source,
 388                          struct in_addr ip)
 389 {
 390   struct nmb_name nn;
 391   struct name_record *n;
 392
 393   make_nmb_name(&nn, name, type, scope);
 394   n = find_name_search(&d, &nn, FIND_LOCAL, ip);
 395
 396   if (n && n->source == source) remove_name(d,n);
 397 }
 398
 399
 400 /****************************************************************************
 401   add an entry to the name list.
 402
 403   this is a multi-purpose function.
 404
 405   it adds samba's own names in to its records on each interface, keeping a
 406   record of whether it is a master browser, domain master, or WINS server.
 407
 408   it also keeps a record of WINS entries.
 409
 410   ****************************************************************************/
 411 struct name_record *add_netbios_entry(struct subnet_record *d,
 412                 char *name, int type, int nb_flags,
 413                 int ttl, enum name_source source, struct in_addr ip,
 414                 BOOL new_only,BOOL wins)
 415 {
 416   struct name_record *n;
 417   struct name_record *n2=NULL;
 418   struct subnet_record *found_subnet = 0;
 419   int search = 0;
 420   BOOL self = source == SELF;
 421
 422   /* add the name to the WINS list if the name comes from a directed query */
 423   search |= wins ? FIND_WINS : FIND_LOCAL;
 424   /* search for SELF names only */
 425   search |= self ? FIND_SELF : 0;
 426
 427   if (!self)
 428   {
 429     if (!wins && type != 0x1b)
 430     {
 431        /* the only broadcast (non-WINS) names we are adding are ours
 432           (SELF) and Domain Master type names */
 433        return NULL;
 434     }
 435   }
 436
 437   n = (struct name_record *)malloc(sizeof(*n));
 438   if (!n) return(NULL);
 439
 440   bzero((char *)n,sizeof(*n));
 441
 442   n->num_ips = 1; /* XXXX ONLY USE THIS FUNCTION FOR ONE ENTRY */
 443   n->ip_flgs = (struct nmb_ip*)malloc(sizeof(*n->ip_flgs) * n->num_ips);
 444   if (!n->ip_flgs)
 445   {
 446      free(n);
 447      return NULL;
 448   }
 449
 450   make_nmb_name(&n->name,name,type,scope);
 451
 452   if ((n2 = find_name_search(&found_subnet, &n->name, search, new_only?ipzero:ip)))
 453   {
 454     free(n->ip_flgs);
 455     free(n);
 456     if (new_only || (n2->source==SELF && source!=SELF)) return n2;
 457     n = n2;
 458     d = found_subnet;
 459   }
 460
 461   if (ttl)
 462      n->death_time = time(NULL)+ttl*3;
 463   n->refresh_time = time(NULL)+GET_TTL(ttl);
 464
 465   /* XXXX only one entry expected with this function */
 466   n->ip_flgs[0].ip = ip;
 467   n->ip_flgs[0].nb_flags = nb_flags;
 468
 469   n->source = source;
 470
 471   if (!n2) add_name(d,n);
 472
 473   DEBUG(3,("Added netbios name %s at %s ttl=%d nb_flags=%2x to interface %s\n",
 474            namestr(&n->name),inet_ntoa(ip),ttl,nb_flags,
 475            ip_equal(d->bcast_ip, wins_ip) ? "WINS" : (char *)inet_ntoa(d->bcast_ip)));
 476
 477   return(n);
 478 }
 479
 480
 481 /*******************************************************************
 482   expires old names in the namelist
 483   ******************************************************************/
 484 void expire_names(time_t t)
 485 {
 486         struct name_record *n;
 487         struct name_record *next;
 488         struct subnet_record *d;
 489
 490         /* expire old names */
 491         for (d = FIRST_SUBNET; d; d = NEXT_SUBNET_INCLUDING_WINS(d))
 492         {
 493           for (n = d->namelist; n; n = next)
 494             {
 495               next = n->next;
 496               if (n->death_time && n->death_time < t)
 497                 {
 498                   if (n->source == SELF) {
 499                     DEBUG(3,("not expiring SELF name %s\n", namestr(&n->name)));
 500                     n->death_time += 300;
 501                     continue;
 502                   }
 503                   DEBUG(3,("Removing dead name %s\n", namestr(&n->name)));
 504
 505                   if (n->prev) n->prev->next = n->next;
 506                   if (n->next) n->next->prev = n->prev;
 507
 508                   if (d->namelist == n) d->namelist = n->next;
 509
 510                   free(n->ip_flgs);
 511                   free(n);
 512                 }
 513             }
 514         }
 515 }
 516
 517
 518 /***************************************************************************
 519   assume a WINS name is a dns name, and do a gethostbyname() on it.
 520   ****************************************************************************/
 521 struct name_record *dns_name_search(struct nmb_name *question, int Time)
 522 {
 523         int name_type = question->name_type;
 524         char *qname = question->name;
 525         char *r;
 526         BOOL dns_type = (name_type == 0x20 || name_type == 0);
 527         struct in_addr dns_ip;
 528
 529         if (wins_subnet == NULL)
 530           return NULL;
 531
 532         DEBUG(3,("Search for %s - ", namestr(question)));
 533
 534         /* only do DNS lookups if the query is for type 0x20 or type 0x0 */
 535         if (!dns_type)
 536         {
 537                 DEBUG(3,("types 0x20 0x0 only: name not found\n"));
 538                 return NULL;
 539         }
 540
 541         /* look it up with DNS */
 542         dns_ip.s_addr = interpret_addr(qname);
 543
 544         if (!dns_ip.s_addr)
 545         {
 546                 /* no luck with DNS. We could possibly recurse here XXXX */
 547                 DEBUG(3,("not found. no recursion.\n"));
 548                 /* add the fail to WINS cache of names. give it 1 hour in the cache */
 549                 add_netbios_entry(wins_subnet,qname,name_type,NB_ACTIVE,60*60,DNSFAIL,dns_ip,
 550                                   True, True);
 551                 return NULL;
 552         }
 553
 554         DEBUG(3,("found with DNS: %s\n", inet_ntoa(dns_ip)));
 555
 556         /* add it to our WINS cache of names. give it 2 hours in the cache */
 557         return add_netbios_entry(wins_subnet,qname,name_type,NB_ACTIVE,2*60*60,DNS,dns_ip,
 558                                  True,True);
 559 }