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