external/bsd/libbind/dist/irs/lcl_ho.c

   1 /*      $NetBSD$        */
   2
   3 /*
   4  * Copyright (c) 1985, 1988, 1993
   5  *    The Regents of the University of California.  All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. All advertising materials mentioning features or use of this software
  16  *    must display the following acknowledgement:
  17  *      This product includes software developed by the University of
  18  *      California, Berkeley and its contributors.
  19  * 4. Neither the name of the University nor the names of its contributors
  20  *    may be used to endorse or promote products derived from this software
  21  *    without specific prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  33  * SUCH DAMAGE.
  34  */
  35
  36 /*
  37  * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
  38  * Portions Copyright (c) 1996-1999 by Internet Software Consortium.
  39  *
  40  * Permission to use, copy, modify, and distribute this software for any
  41  * purpose with or without fee is hereby granted, provided that the above
  42  * copyright notice and this permission notice appear in all copies.
  43  *
  44  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
  45  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  46  * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
  47  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  48  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  49  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
  50  * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  51  */
  52
  53 /* from gethostnamadr.c 8.1 (Berkeley) 6/4/93 */
  54 /* BIND Id: gethnamaddr.c,v 8.15 1996/05/22 04:56:30 vixie Exp $ */
  55
  56 #if defined(LIBC_SCCS) && !defined(lint)
  57 static const char rcsid[] = "Id: lcl_ho.c,v 1.5 2006/03/09 23:57:56 marka Exp";
  58 #endif /* LIBC_SCCS and not lint */
  59
  60 /* Imports. */
  61
  62 #include "port_before.h"
  63
  64 #include <sys/types.h>
  65 #include <sys/param.h>
  66 #include <sys/socket.h>
  67
  68 #include <netinet/in.h>
  69 #include <arpa/inet.h>
  70 #include <arpa/nameser.h>
  71
  72 #include <ctype.h>
  73 #include <errno.h>
  74 #include <fcntl.h>
  75 #include <netdb.h>
  76 #include <resolv.h>
  77 #include <stdio.h>
  78 #include <stdlib.h>
  79 #include <string.h>
  80
  81 #include <irs.h>
  82 #include <isc/memcluster.h>
  83
  84 #include "port_after.h"
  85
  86 #include "irs_p.h"
  87 #include "dns_p.h"
  88 #include "lcl_p.h"
  89
  90 #ifdef SPRINTF_CHAR
  91 # define SPRINTF(x) strlen(sprintf/**/x)
  92 #else
  93 # define SPRINTF(x) sprintf x
  94 #endif
  95
  96 /* Definitions. */
  97
  98 #define MAXALIASES      35
  99 #define MAXADDRS        35
 100 #define Max(a,b)        ((a) > (b) ? (a) : (b))
 101
 102 #if PACKETSZ > 1024
 103 #define MAXPACKET       PACKETSZ
 104 #else
 105 #define MAXPACKET       1024
 106 #endif
 107
 108 struct pvt {
 109         FILE *          fp;
 110         struct hostent  host;
 111         char *          h_addr_ptrs[MAXADDRS + 1];
 112         char *          host_aliases[MAXALIASES];
 113         char            hostbuf[8*1024];
 114         u_char          host_addr[16];  /*%< IPv4 or IPv6 */
 115         struct __res_state  *res;
 116         void            (*free_res)(void *);
 117 };
 118
 119 typedef union {
 120         int32_t al;
 121         char ac;
 122 } align;
 123
 124 static const u_char mapped[] = { 0,0, 0,0, 0,0, 0,0, 0,0, 0xff,0xff };
 125 static const u_char tunnelled[] = { 0,0, 0,0, 0,0, 0,0, 0,0, 0,0 };
 126
 127 /* Forward. */
 128
 129 static void             ho_close(struct irs_ho *this);
 130 static struct hostent * ho_byname(struct irs_ho *this, const char *name);
 131 static struct hostent * ho_byname2(struct irs_ho *this, const char *name,
 132                                    int af);
 133 static struct hostent * ho_byaddr(struct irs_ho *this, const void *addr,
 134                                   int len, int af);
 135 static struct hostent * ho_next(struct irs_ho *this);
 136 static void             ho_rewind(struct irs_ho *this);
 137 static void             ho_minimize(struct irs_ho *this);
 138 static struct __res_state * ho_res_get(struct irs_ho *this);
 139 static void             ho_res_set(struct irs_ho *this,
 140                                    struct __res_state *res,
 141                                    void (*free_res)(void *));
 142 static struct addrinfo * ho_addrinfo(struct irs_ho *this, const char *name,
 143                                      const struct addrinfo *pai);
 144
 145 static size_t           ns_namelen(const char *);
 146 static int              init(struct irs_ho *this);
 147
 148 /* Portability. */
 149
 150 #ifndef SEEK_SET
 151 # define SEEK_SET 0
 152 #endif
 153
 154 /* Public. */
 155
 156 struct irs_ho *
 157 irs_lcl_ho(struct irs_acc *this) {
 158         struct irs_ho *ho;
 159         struct pvt *pvt;
 160
 161         UNUSED(this);
 162
 163         if (!(pvt = memget(sizeof *pvt))) {
 164                 errno = ENOMEM;
 165                 return (NULL);
 166         }
 167         memset(pvt, 0, sizeof *pvt);
 168         if (!(ho = memget(sizeof *ho))) {
 169                 memput(pvt, sizeof *pvt);
 170                 errno = ENOMEM;
 171                 return (NULL);
 172         }
 173         memset(ho, 0x5e, sizeof *ho);
 174         ho->private = pvt;
 175         ho->close = ho_close;
 176         ho->byname = ho_byname;
 177         ho->byname2 = ho_byname2;
 178         ho->byaddr = ho_byaddr;
 179         ho->next = ho_next;
 180         ho->rewind = ho_rewind;
 181         ho->minimize = ho_minimize;
 182         ho->res_get = ho_res_get;
 183         ho->res_set = ho_res_set;
 184         ho->addrinfo = ho_addrinfo;
 185         return (ho);
 186 }
 187
 188 /* Methods. */
 189
 190 static void
 191 ho_close(struct irs_ho *this) {
 192         struct pvt *pvt = (struct pvt *)this->private;
 193
 194         ho_minimize(this);
 195         if (pvt->fp)
 196                 (void) fclose(pvt->fp);
 197         if (pvt->res && pvt->free_res)
 198                 (*pvt->free_res)(pvt->res);
 199         memput(pvt, sizeof *pvt);
 200         memput(this, sizeof *this);
 201 }
 202
 203 static struct hostent *
 204 ho_byname(struct irs_ho *this, const char *name) {
 205         struct pvt *pvt = (struct pvt *)this->private;
 206         struct hostent *hp;
 207
 208         if (init(this) == -1)
 209                 return (NULL);
 210
 211         if (pvt->res->options & RES_USE_INET6) {
 212                 hp = ho_byname2(this, name, AF_INET6);
 213                 if (hp)
 214                         return (hp);
 215         }
 216         return (ho_byname2(this, name, AF_INET));
 217 }
 218
 219 static struct hostent *
 220 ho_byname2(struct irs_ho *this, const char *name, int af) {
 221         struct pvt *pvt = (struct pvt *)this->private;
 222         struct hostent *hp;
 223         char **hap;
 224         size_t n;
 225
 226         if (init(this) == -1)
 227                 return (NULL);
 228
 229         ho_rewind(this);
 230         n = ns_namelen(name);
 231         while ((hp = ho_next(this)) != NULL) {
 232                 size_t nn;
 233
 234                 if (hp->h_addrtype != af)
 235                         continue;
 236                 nn = ns_namelen(hp->h_name);
 237                 if (strncasecmp(hp->h_name, name, Max(n, nn)) == 0)
 238                         goto found;
 239                 for (hap = hp->h_aliases; *hap; hap++) {
 240                         nn = ns_namelen(*hap);
 241                         if (strncasecmp(*hap, name, Max(n, nn)) == 0)
 242                                 goto found;
 243                 }
 244         }
 245  found:
 246         if (!hp) {
 247                 RES_SET_H_ERRNO(pvt->res, HOST_NOT_FOUND);
 248                 return (NULL);
 249         }
 250         RES_SET_H_ERRNO(pvt->res, NETDB_SUCCESS);
 251         return (hp);
 252 }
 253
 254 static struct hostent *
 255 ho_byaddr(struct irs_ho *this, const void *addr, int len, int af) {
 256         struct pvt *pvt = (struct pvt *)this->private;
 257         const u_char *uaddr = addr;
 258         struct hostent *hp;
 259         int size;
 260
 261         if (init(this) == -1)
 262                 return (NULL);
 263
 264         if (af == AF_INET6 && len == IN6ADDRSZ &&
 265             (!memcmp(uaddr, mapped, sizeof mapped) ||
 266              !memcmp(uaddr, tunnelled, sizeof tunnelled))) {
 267                 /* Unmap. */
 268                 addr = (const u_char *)addr + sizeof mapped;
 269                 uaddr += sizeof mapped;
 270                 af = AF_INET;
 271                 len = INADDRSZ;
 272         }
 273         switch (af) {
 274         case AF_INET:
 275                 size = INADDRSZ;
 276                 break;
 277         case AF_INET6:
 278                 size = IN6ADDRSZ;
 279                 break;
 280         default:
 281                 errno = EAFNOSUPPORT;
 282                 RES_SET_H_ERRNO(pvt->res, NETDB_INTERNAL);
 283                 return (NULL);
 284         }
 285         if (size > len) {
 286                 errno = EINVAL;
 287                 RES_SET_H_ERRNO(pvt->res, NETDB_INTERNAL);
 288                 return (NULL);
 289         }
 290
 291         /*
 292          * Do the search.
 293          */
 294         ho_rewind(this);
 295         while ((hp = ho_next(this)) != NULL) {
 296                 char **hap;
 297
 298                 for (hap = hp->h_addr_list; *hap; hap++) {
 299                         const u_char *taddr = (const u_char *)*hap;
 300                         int taf = hp->h_addrtype;
 301                         int tlen = hp->h_length;
 302
 303                         if (taf == AF_INET6 && tlen == IN6ADDRSZ &&
 304                             (!memcmp(taddr, mapped, sizeof mapped) ||
 305                              !memcmp(taddr, tunnelled, sizeof tunnelled))) {
 306                                 /* Unmap. */
 307                                 taddr += sizeof mapped;
 308                                 taf = AF_INET;
 309                                 tlen = INADDRSZ;
 310                         }
 311                         if (taf == af && tlen == len &&
 312                             !memcmp(taddr, uaddr, tlen))
 313                                 goto found;
 314                 }
 315         }
 316  found:
 317         if (!hp) {
 318                 RES_SET_H_ERRNO(pvt->res, HOST_NOT_FOUND);
 319                 return (NULL);
 320         }
 321         RES_SET_H_ERRNO(pvt->res, NETDB_SUCCESS);
 322         return (hp);
 323 }
 324
 325 static struct hostent *
 326 ho_next(struct irs_ho *this) {
 327         struct pvt *pvt = (struct pvt *)this->private;
 328         char *cp, **q, *p;
 329         char *bufp, *ndbuf, *dbuf = NULL;
 330         int c, af, len, bufsiz, offset;
 331
 332         if (init(this) == -1)
 333                 return (NULL);
 334
 335         if (!pvt->fp)
 336                 ho_rewind(this);
 337         if (!pvt->fp) {
 338                 RES_SET_H_ERRNO(pvt->res, NETDB_INTERNAL);
 339                 return (NULL);
 340         }
 341         bufp = pvt->hostbuf;
 342         bufsiz = sizeof pvt->hostbuf;
 343         offset = 0;
 344  again:
 345         if (!(p = fgets(bufp + offset, bufsiz - offset, pvt->fp))) {
 346                 RES_SET_H_ERRNO(pvt->res, HOST_NOT_FOUND);
 347                 if (dbuf)
 348                         free(dbuf);
 349                 return (NULL);
 350         }
 351         if (!strchr(p, '\n') && !feof(pvt->fp)) {
 352 #define GROWBUF 1024
 353                 /* allocate space for longer line */
 354                 if (dbuf == NULL) {
 355                         if ((ndbuf = malloc(bufsiz + GROWBUF)) != NULL)
 356                                 strcpy(ndbuf, bufp);
 357                 } else
 358                         ndbuf = realloc(dbuf, bufsiz + GROWBUF);
 359                 if (ndbuf) {
 360                         dbuf = ndbuf;
 361                         bufp = dbuf;
 362                         bufsiz += GROWBUF;
 363                         offset = strlen(dbuf);
 364                 } else {
 365                         /* allocation failed; skip this long line */
 366                         while ((c = getc(pvt->fp)) != EOF)
 367                                 if (c == '\n')
 368                                         break;
 369                         if (c != EOF)
 370                                 ungetc(c, pvt->fp);
 371                 }
 372                 goto again;
 373         }
 374
 375         p -= offset;
 376         offset = 0;
 377
 378         if (*p == '#')
 379                 goto again;
 380         if ((cp = strpbrk(p, "#\n")) != NULL)
 381                 *cp = '\0';
 382         if (!(cp = strpbrk(p, " \t")))
 383                 goto again;
 384         *cp++ = '\0';
 385         if (inet_pton(AF_INET6, p, pvt->host_addr) > 0) {
 386                 af = AF_INET6;
 387                 len = IN6ADDRSZ;
 388         } else if (inet_aton(p, (struct in_addr *)pvt->host_addr) > 0) {
 389                 if (pvt->res->options & RES_USE_INET6) {
 390                         map_v4v6_address((char*)pvt->host_addr,
 391                                          (char*)pvt->host_addr);
 392                         af = AF_INET6;
 393                         len = IN6ADDRSZ;
 394                 } else {
 395                         af = AF_INET;
 396                         len = INADDRSZ;
 397                 }
 398         } else {
 399                 goto again;
 400         }
 401         pvt->h_addr_ptrs[0] = (char *)pvt->host_addr;
 402         pvt->h_addr_ptrs[1] = NULL;
 403         pvt->host.h_addr_list = pvt->h_addr_ptrs;
 404         pvt->host.h_length = len;
 405         pvt->host.h_addrtype = af;
 406         while (*cp == ' ' || *cp == '\t')
 407                 cp++;
 408         pvt->host.h_name = cp;
 409         q = pvt->host.h_aliases = pvt->host_aliases;
 410         if ((cp = strpbrk(cp, " \t")) != NULL)
 411                 *cp++ = '\0';
 412         while (cp && *cp) {
 413                 if (*cp == ' ' || *cp == '\t') {
 414                         cp++;
 415                         continue;
 416                 }
 417                 if (q < &pvt->host_aliases[MAXALIASES - 1])
 418                         *q++ = cp;
 419                 if ((cp = strpbrk(cp, " \t")) != NULL)
 420                         *cp++ = '\0';
 421         }
 422         *q = NULL;
 423         if (dbuf)
 424                 free(dbuf);
 425         RES_SET_H_ERRNO(pvt->res, NETDB_SUCCESS);
 426         return (&pvt->host);
 427 }
 428
 429 static void
 430 ho_rewind(struct irs_ho *this) {
 431         struct pvt *pvt = (struct pvt *)this->private;
 432
 433         if (pvt->fp) {
 434                 if (fseek(pvt->fp, 0L, SEEK_SET) == 0)
 435                         return;
 436                 (void)fclose(pvt->fp);
 437         }
 438         if (!(pvt->fp = fopen(_PATH_HOSTS, "r")))
 439                 return;
 440         if (fcntl(fileno(pvt->fp), F_SETFD, 1) < 0) {
 441                 (void)fclose(pvt->fp);
 442                 pvt->fp = NULL;
 443         }
 444 }
 445
 446 static void
 447 ho_minimize(struct irs_ho *this) {
 448         struct pvt *pvt = (struct pvt *)this->private;
 449
 450         if (pvt->fp != NULL) {
 451                 (void)fclose(pvt->fp);
 452                 pvt->fp = NULL;
 453         }
 454         if (pvt->res)
 455                 res_nclose(pvt->res);
 456 }
 457
 458 static struct __res_state *
 459 ho_res_get(struct irs_ho *this) {
 460         struct pvt *pvt = (struct pvt *)this->private;
 461
 462         if (!pvt->res) {
 463                 struct __res_state *res;
 464                 res = (struct __res_state *)malloc(sizeof *res);
 465                 if (!res) {
 466                         errno = ENOMEM;
 467                         return (NULL);
 468                 }
 469                 memset(res, 0, sizeof *res);
 470                 ho_res_set(this, res, free);
 471         }
 472
 473         return (pvt->res);
 474 }
 475
 476 static void
 477 ho_res_set(struct irs_ho *this, struct __res_state *res,
 478                 void (*free_res)(void *)) {
 479         struct pvt *pvt = (struct pvt *)this->private;
 480
 481         if (pvt->res && pvt->free_res) {
 482                 res_nclose(pvt->res);
 483                 (*pvt->free_res)(pvt->res);
 484         }
 485
 486         pvt->res = res;
 487         pvt->free_res = free_res;
 488 }
 489
 490 struct lcl_res_target {
 491         struct lcl_res_target *next;
 492         int family;
 493 };
 494
 495 /* XXX */
 496 extern struct addrinfo *hostent2addrinfo __P((struct hostent *,
 497                                               const struct addrinfo *pai));
 498
 499 static struct addrinfo *
 500 ho_addrinfo(struct irs_ho *this, const char *name, const struct addrinfo *pai)
 501 {
 502         struct pvt *pvt = (struct pvt *)this->private;
 503         struct hostent *hp;
 504         struct lcl_res_target q, q2, *p;
 505         struct addrinfo sentinel, *cur;
 506
 507         memset(&q, 0, sizeof(q2));
 508         memset(&q2, 0, sizeof(q2));
 509         memset(&sentinel, 0, sizeof(sentinel));
 510         cur = &sentinel;
 511
 512         switch(pai->ai_family) {
 513         case AF_UNSPEC:         /*%< INET6 then INET4 */
 514                 q.family = AF_INET6;
 515                 q.next = &q2;
 516                 q2.family = AF_INET;
 517                 break;
 518         case AF_INET6:
 519                 q.family = AF_INET6;
 520                 break;
 521         case AF_INET:
 522                 q.family = AF_INET;
 523                 break;
 524         default:
 525                 RES_SET_H_ERRNO(pvt->res, NO_RECOVERY); /*%< ??? */
 526                 return(NULL);
 527         }
 528
 529         for (p = &q; p; p = p->next) {
 530                 struct addrinfo *ai;
 531
 532                 hp = (*this->byname2)(this, name, p->family);
 533                 if (hp == NULL) {
 534                         /* byname2 should've set an appropriate error */
 535                         continue;
 536                 }
 537                 if ((hp->h_name == NULL) || (hp->h_name[0] == 0) ||
 538                     (hp->h_addr_list[0] == NULL)) {
 539                         RES_SET_H_ERRNO(pvt->res, NO_RECOVERY);
 540                         continue;
 541                 }
 542
 543                 ai = hostent2addrinfo(hp, pai);
 544                 if (ai) {
 545                         cur->ai_next = ai;
 546                         while (cur->ai_next)
 547                                 cur = cur->ai_next;
 548                 }
 549         }
 550
 551         if (sentinel.ai_next == NULL)
 552                 RES_SET_H_ERRNO(pvt->res, HOST_NOT_FOUND);
 553
 554         return(sentinel.ai_next);
 555 }
 556
 557 /* Private. */
 558
 559 static size_t
 560 ns_namelen(const char *s) {
 561         int i;
 562
 563         for (i = strlen(s); i > 0 && s[i-1] == '.'; i--)
 564                 (void)NULL;
 565         return ((size_t) i);
 566 }
 567
 568 static int
 569 init(struct irs_ho *this) {
 570         struct pvt *pvt = (struct pvt *)this->private;
 571
 572         if (!pvt->res && !ho_res_get(this))
 573                 return (-1);
 574         if (((pvt->res->options & RES_INIT) == 0U) &&
 575             res_ninit(pvt->res) == -1)
 576                 return (-1);
 577         return (0);
 578 }
 579
 580 /*! \file */