lib/libc/net/gethnamaddr.c

   1 /*      $NetBSD: gethnamaddr.c,v 1.74 2009/10/02 06:49:23 cegger Exp $  */
   2
   3 /*
   4  * ++Copyright++ 1985, 1988, 1993
   5  * -
   6  * Copyright (c) 1985, 1988, 1993
   7  *    The Regents of the University of California.  All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  * 3. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  * -
  33  * Portions Copyright (c) 1993 by Digital Equipment Corporation.
  34  *
  35  * Permission to use, copy, modify, and distribute this software for any
  36  * purpose with or without fee is hereby granted, provided that the above
  37  * copyright notice and this permission notice appear in all copies, and that
  38  * the name of Digital Equipment Corporation not be used in advertising or
  39  * publicity pertaining to distribution of the document or software without
  40  * specific, written prior permission.
  41  *
  42  * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
  43  * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
  44  * OF MERCHANTABILITY AND FITNESS.   IN NO EVENT SHALL DIGITAL EQUIPMENT
  45  * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
  46  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
  47  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
  48  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
  49  * SOFTWARE.
  50  * -
  51  * --Copyright--
  52  */
  53
  54 #include <sys/cdefs.h>
  55 #if defined(LIBC_SCCS) && !defined(lint)
  56 #if 0
  57 static char sccsid[] = "@(#)gethostnamadr.c     8.1 (Berkeley) 6/4/93";
  58 static char rcsid[] = "Id: gethnamaddr.c,v 8.21 1997/06/01 20:34:37 vixie Exp ";
  59 #else
  60 __RCSID("$NetBSD: gethnamaddr.c,v 1.74 2009/10/02 06:49:23 cegger Exp $");
  61 #endif
  62 #endif /* LIBC_SCCS and not lint */
  63
  64 #if defined(_LIBC)
  65 #include "namespace.h"
  66 #endif
  67 #include <sys/param.h>
  68 #include <sys/socket.h>
  69 #include <netinet/in.h>
  70 #include <arpa/inet.h>
  71 #include <arpa/nameser.h>
  72
  73 #include <assert.h>
  74 #include <ctype.h>
  75 #include <errno.h>
  76 #include <netdb.h>
  77 #include <resolv.h>
  78 #include <stdarg.h>
  79 #include <stdio.h>
  80 #include <syslog.h>
  81
  82 #ifndef LOG_AUTH
  83 # define LOG_AUTH 0
  84 #endif
  85
  86 #define MULTI_PTRS_ARE_ALIASES 1        /* XXX - experimental */
  87
  88 #include <nsswitch.h>
  89 #include <stdlib.h>
  90 #include <string.h>
  91
  92 #ifdef YP
  93 #include <rpc/rpc.h>
  94 #include <rpcsvc/yp_prot.h>
  95 #include <rpcsvc/ypclnt.h>
  96 #endif
  97
  98 #if defined(_LIBC) && defined(__weak_alias)
  99 __weak_alias(gethostbyaddr,_gethostbyaddr)
 100 __weak_alias(gethostbyname,_gethostbyname)
 101 __weak_alias(gethostent,_gethostent)
 102 #endif
 103
 104 #define MAXALIASES      35
 105 #define MAXADDRS        35
 106
 107 static const char AskedForGot[] =
 108                           "gethostby*.getanswer: asked for \"%s\", got \"%s\"";
 109
 110 static char *h_addr_ptrs[MAXADDRS + 1];
 111
 112 #ifdef YP
 113 static char *__ypdomain;
 114 #endif
 115
 116 static struct hostent host;
 117 static char *host_aliases[MAXALIASES];
 118 static char hostbuf[8*1024];
 119 static u_int32_t host_addr[16 / sizeof(u_int32_t)];     /* IPv4 or IPv6 */
 120 static FILE *hostf = NULL;
 121 static int stayopen = 0;
 122
 123 #define MAXPACKET       (64*1024)
 124
 125 typedef union {
 126     HEADER hdr;
 127     u_char buf[MAXPACKET];
 128 } querybuf;
 129
 130 typedef union {
 131     int32_t al;
 132     char ac;
 133 } align;
 134
 135 #ifdef DEBUG
 136 static void dprintf(const char *, res_state, ...)
 137         __attribute__((__format__(__printf__, 1, 3)));
 138 #endif
 139 static struct hostent *getanswer(const querybuf *, int, const char *, int,
 140     res_state);
 141 static void map_v4v6_address(const char *, char *);
 142 static void map_v4v6_hostent(struct hostent *, char **, char *);
 143 static void addrsort(char **, int, res_state);
 144
 145 void _sethtent(int);
 146 void _endhtent(void);
 147 struct hostent *_gethtent(void);
 148 void ht_sethostent(int);
 149 void ht_endhostent(void);
 150 struct hostent *ht_gethostbyname(char *);
 151 struct hostent *ht_gethostbyaddr(const char *, int, int);
 152 void dns_service(void);
 153 #undef dn_skipname
 154 int dn_skipname(const u_char *, const u_char *);
 155 int _gethtbyaddr(void *, void *, va_list);
 156 int _gethtbyname(void *, void *, va_list);
 157 struct hostent *_gethtbyname2(const char *, int);
 158 int _dns_gethtbyaddr(void *, void *, va_list);
 159 int _dns_gethtbyname(void *, void *, va_list);
 160 #ifdef YP
 161 struct hostent *_yphostent(char *, int);
 162 int _yp_gethtbyaddr(void *, void *, va_list);
 163 int _yp_gethtbyname(void *, void *, va_list);
 164 #endif
 165
 166 static struct hostent *gethostbyname_internal(const char *, int, res_state);
 167
 168 static const ns_src default_dns_files[] = {
 169         { NSSRC_FILES,  NS_SUCCESS },
 170         { NSSRC_DNS,    NS_SUCCESS },
 171         { 0, 0 }
 172 };
 173
 174
 175 #ifdef DEBUG
 176 static void
 177 dprintf(const char *msg, res_state res, ...)
 178 {
 179         _DIAGASSERT(msg != NULL);
 180
 181         if (res->options & RES_DEBUG) {
 182                 int save = errno;
 183                 va_list ap;
 184
 185                 va_start (ap, res);
 186                 vprintf(msg, ap);
 187                 va_end (ap);
 188
 189                 errno = save;
 190         }
 191 }
 192 #else
 193 # define dprintf(msg, res, num) /*nada*/
 194 #endif
 195
 196 #define BOUNDED_INCR(x) \
 197         do { \
 198                 cp += (x); \
 199                 if (cp > eom) { \
 200                         h_errno = NO_RECOVERY; \
 201                         return NULL; \
 202                 } \
 203         } while (/*CONSTCOND*/0)
 204
 205 #define BOUNDS_CHECK(ptr, count) \
 206         do { \
 207                 if ((ptr) + (count) > eom) { \
 208                         h_errno = NO_RECOVERY; \
 209                         return NULL; \
 210                 } \
 211         } while (/*CONSTCOND*/0)
 212
 213 static struct hostent *
 214 getanswer(const querybuf *answer, int anslen, const char *qname, int qtype,
 215     res_state res)
 216 {
 217         const HEADER *hp;
 218         const u_char *cp;
 219         int n;
 220         const u_char *eom, *erdata;
 221         char *bp, **ap, **hap, *ep;
 222         int type, class, ancount, qdcount;
 223         int haveanswer, had_error;
 224         int toobig = 0;
 225         char tbuf[MAXDNAME];
 226         const char *tname;
 227         int (*name_ok)(const char *);
 228
 229         _DIAGASSERT(answer != NULL);
 230         _DIAGASSERT(qname != NULL);
 231
 232         tname = qname;
 233         host.h_name = NULL;
 234         eom = answer->buf + anslen;
 235         switch (qtype) {
 236         case T_A:
 237         case T_AAAA:
 238                 name_ok = res_hnok;
 239                 break;
 240         case T_PTR:
 241                 name_ok = res_dnok;
 242                 break;
 243         default:
 244                 return NULL;    /* XXX should be abort(); */
 245         }
 246         /*
 247          * find first satisfactory answer
 248          */
 249         hp = &answer->hdr;
 250         ancount = ntohs(hp->ancount);
 251         qdcount = ntohs(hp->qdcount);
 252         bp = hostbuf;
 253         ep = hostbuf + sizeof hostbuf;
 254         cp = answer->buf;
 255         BOUNDED_INCR(HFIXEDSZ);
 256         if (qdcount != 1) {
 257                 h_errno = NO_RECOVERY;
 258                 return NULL;
 259         }
 260         n = dn_expand(answer->buf, eom, cp, bp, ep - bp);
 261         if ((n < 0) || !(*name_ok)(bp)) {
 262                 h_errno = NO_RECOVERY;
 263                 return NULL;
 264         }
 265         BOUNDED_INCR(n + QFIXEDSZ);
 266         if (qtype == T_A || qtype == T_AAAA) {
 267                 /* res_send() has already verified that the query name is the
 268                  * same as the one we sent; this just gets the expanded name
 269                  * (i.e., with the succeeding search-domain tacked on).
 270                  */
 271                 n = strlen(bp) + 1;             /* for the \0 */
 272                 if (n >= MAXHOSTNAMELEN) {
 273                         h_errno = NO_RECOVERY;
 274                         return NULL;
 275                 }
 276                 host.h_name = bp;
 277                 bp += n;
 278                 /* The qname can be abbreviated, but h_name is now absolute. */
 279                 qname = host.h_name;
 280         }
 281         ap = host_aliases;
 282         *ap = NULL;
 283         host.h_aliases = host_aliases;
 284         hap = h_addr_ptrs;
 285         *hap = NULL;
 286         host.h_addr_list = h_addr_ptrs;
 287         haveanswer = 0;
 288         had_error = 0;
 289         while (ancount-- > 0 && cp < eom && !had_error) {
 290                 n = dn_expand(answer->buf, eom, cp, bp, ep - bp);
 291                 if ((n < 0) || !(*name_ok)(bp)) {
 292                         had_error++;
 293                         continue;
 294                 }
 295                 cp += n;                        /* name */
 296                 BOUNDS_CHECK(cp, 3 * INT16SZ + INT32SZ);
 297                 type = _getshort(cp);
 298                 cp += INT16SZ;                  /* type */
 299                 class = _getshort(cp);
 300                 cp += INT16SZ + INT32SZ;        /* class, TTL */
 301                 n = _getshort(cp);
 302                 cp += INT16SZ;                  /* len */
 303                 BOUNDS_CHECK(cp, n);
 304                 erdata = cp + n;
 305                 if (class != C_IN) {
 306                         /* XXX - debug? syslog? */
 307                         cp += n;
 308                         continue;               /* XXX - had_error++ ? */
 309                 }
 310                 if ((qtype == T_A || qtype == T_AAAA) && type == T_CNAME) {
 311                         if (ap >= &host_aliases[MAXALIASES-1])
 312                                 continue;
 313                         n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf);
 314                         if ((n < 0) || !(*name_ok)(tbuf)) {
 315                                 had_error++;
 316                                 continue;
 317                         }
 318                         cp += n;
 319                         if (cp != erdata) {
 320                                 h_errno = NO_RECOVERY;
 321                                 return NULL;
 322                         }
 323                         /* Store alias. */
 324                         *ap++ = bp;
 325                         n = strlen(bp) + 1;     /* for the \0 */
 326                         if (n >= MAXHOSTNAMELEN) {
 327                                 had_error++;
 328                                 continue;
 329                         }
 330                         bp += n;
 331                         /* Get canonical name. */
 332                         n = strlen(tbuf) + 1;   /* for the \0 */
 333                         if (n > ep - bp || n >= MAXHOSTNAMELEN) {
 334                                 had_error++;
 335                                 continue;
 336                         }
 337                         strlcpy(bp, tbuf, (size_t)(ep - bp));
 338                         host.h_name = bp;
 339                         bp += n;
 340                         continue;
 341                 }
 342                 if (qtype == T_PTR && type == T_CNAME) {
 343                         n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf);
 344                         if (n < 0 || !res_dnok(tbuf)) {
 345                                 had_error++;
 346                                 continue;
 347                         }
 348                         cp += n;
 349                         if (cp != erdata) {
 350                                 h_errno = NO_RECOVERY;
 351                                 return NULL;
 352                         }
 353                         /* Get canonical name. */
 354                         n = strlen(tbuf) + 1;   /* for the \0 */
 355                         if (n > ep - bp || n >= MAXHOSTNAMELEN) {
 356                                 had_error++;
 357                                 continue;
 358                         }
 359                         strlcpy(bp, tbuf, (size_t)(ep - bp));
 360                         tname = bp;
 361                         bp += n;
 362                         continue;
 363                 }
 364                 if (type != qtype) {
 365                         if (type != T_KEY && type != T_SIG)
 366                                 syslog(LOG_NOTICE|LOG_AUTH,
 367                "gethostby*.getanswer: asked for \"%s %s %s\", got type \"%s\"",
 368                                        qname, p_class(C_IN), p_type(qtype),
 369                                        p_type(type));
 370                         cp += n;
 371                         continue;               /* XXX - had_error++ ? */
 372                 }
 373                 switch (type) {
 374                 case T_PTR:
 375                         if (strcasecmp(tname, bp) != 0) {
 376                                 syslog(LOG_NOTICE|LOG_AUTH,
 377                                        AskedForGot, qname, bp);
 378                                 cp += n;
 379                                 continue;       /* XXX - had_error++ ? */
 380                         }
 381                         n = dn_expand(answer->buf, eom, cp, bp, ep - bp);
 382                         if ((n < 0) || !res_hnok(bp)) {
 383                                 had_error++;
 384                                 break;
 385                         }
 386 #if MULTI_PTRS_ARE_ALIASES
 387                         cp += n;
 388                         if (cp != erdata) {
 389                                 h_errno = NO_RECOVERY;
 390                                 return NULL;
 391                         }
 392                         if (!haveanswer)
 393                                 host.h_name = bp;
 394                         else if (ap < &host_aliases[MAXALIASES-1])
 395                                 *ap++ = bp;
 396                         else
 397                                 n = -1;
 398                         if (n != -1) {
 399                                 n = strlen(bp) + 1;     /* for the \0 */
 400                                 if (n >= MAXHOSTNAMELEN) {
 401                                         had_error++;
 402                                         break;
 403                                 }
 404                                 bp += n;
 405                         }
 406                         break;
 407 #else
 408                         host.h_name = bp;
 409                         if (res->options & RES_USE_INET6) {
 410                                 n = strlen(bp) + 1;     /* for the \0 */
 411                                 if (n >= MAXHOSTNAMELEN) {
 412                                         had_error++;
 413                                         break;
 414                                 }
 415                                 bp += n;
 416                                 map_v4v6_hostent(&host, &bp, ep);
 417                         }
 418                         h_errno = NETDB_SUCCESS;
 419                         return &host;
 420 #endif
 421                 case T_A:
 422                 case T_AAAA:
 423                         if (strcasecmp(host.h_name, bp) != 0) {
 424                                 syslog(LOG_NOTICE|LOG_AUTH,
 425                                        AskedForGot, host.h_name, bp);
 426                                 cp += n;
 427                                 continue;       /* XXX - had_error++ ? */
 428                         }
 429                         if (n != host.h_length) {
 430                                 cp += n;
 431                                 continue;
 432                         }
 433                         if (type == T_AAAA) {
 434                                 struct in6_addr in6;
 435                                 memcpy(&in6, cp, IN6ADDRSZ);
 436                                 if (IN6_IS_ADDR_V4MAPPED(&in6)) {
 437                                         cp += n;
 438                                         continue;
 439                                 }
 440                         }
 441                         if (!haveanswer) {
 442                                 int nn;
 443
 444                                 host.h_name = bp;
 445                                 nn = strlen(bp) + 1;    /* for the \0 */
 446                                 bp += nn;
 447                         }
 448
 449                         bp += sizeof(align) -
 450                             (size_t)((u_long)bp % sizeof(align));
 451
 452                         if (bp + n >= &hostbuf[sizeof hostbuf]) {
 453                                 dprintf("size (%d) too big\n", res, n);
 454                                 had_error++;
 455                                 continue;
 456                         }
 457                         if (hap >= &h_addr_ptrs[MAXADDRS-1]) {
 458                                 if (!toobig++) {
 459                                         dprintf("Too many addresses (%d)\n",
 460                                                 res, MAXADDRS);
 461                                 }
 462                                 cp += n;
 463                                 continue;
 464                         }
 465                         (void)memcpy(*hap++ = bp, cp, (size_t)n);
 466                         bp += n;
 467                         cp += n;
 468                         if (cp != erdata) {
 469                                 h_errno = NO_RECOVERY;
 470                                 return NULL;
 471                         }
 472                         break;
 473                 default:
 474                         abort();
 475                 }
 476                 if (!had_error)
 477                         haveanswer++;
 478         }
 479         if (haveanswer) {
 480                 *ap = NULL;
 481                 *hap = NULL;
 482                 /*
 483                  * Note: we sort even if host can take only one address
 484                  * in its return structures - should give it the "best"
 485                  * address in that case, not some random one
 486                  */
 487                 if (res->nsort && haveanswer > 1 && qtype == T_A)
 488                         addrsort(h_addr_ptrs, haveanswer, res);
 489                 if (!host.h_name) {
 490                         n = strlen(qname) + 1;  /* for the \0 */
 491                         if (n > ep - bp || n >= MAXHOSTNAMELEN)
 492                                 goto no_recovery;
 493                         strlcpy(bp, qname, (size_t)(ep - bp));
 494                         host.h_name = bp;
 495                         bp += n;
 496                 }
 497                 if (res->options & RES_USE_INET6)
 498                         map_v4v6_hostent(&host, &bp, ep);
 499                 h_errno = NETDB_SUCCESS;
 500                 return &host;
 501         }
 502  no_recovery:
 503         h_errno = NO_RECOVERY;
 504         return NULL;
 505 }
 506
 507 struct hostent *
 508 gethostbyname(const char *name)
 509 {
 510         struct hostent *hp;
 511         res_state res = __res_get_state();
 512
 513         if (res == NULL)
 514                 return NULL;
 515
 516         _DIAGASSERT(name != NULL);
 517
 518         if (res->options & RES_USE_INET6) {
 519                 hp = gethostbyname_internal(name, AF_INET6, res);
 520                 if (hp) {
 521                         __res_put_state(res);
 522                         return hp;
 523                 }
 524         }
 525         hp = gethostbyname_internal(name, AF_INET, res);
 526         __res_put_state(res);
 527         return hp;
 528 }
 529
 530 struct hostent *
 531 gethostbyname2(const char *name, int af)
 532 {
 533         struct hostent *hp;
 534         res_state res = __res_get_state();
 535
 536         if (res == NULL)
 537                 return NULL;
 538         hp = gethostbyname_internal(name, af, res);
 539         __res_put_state(res);
 540         return hp;
 541 }
 542
 543 static struct hostent *
 544 gethostbyname_internal(const char *name, int af, res_state res)
 545 {
 546         const char *cp;
 547         char *bp, *ep;
 548         int size;
 549         struct hostent *hp;
 550         static const ns_dtab dtab[] = {
 551                 NS_FILES_CB(_gethtbyname, NULL)
 552                 { NSSRC_DNS, _dns_gethtbyname, NULL },  /* force -DHESIOD */
 553                 NS_NIS_CB(_yp_gethtbyname, NULL)
 554                 NS_NULL_CB
 555         };
 556
 557         _DIAGASSERT(name != NULL);
 558
 559         switch (af) {
 560         case AF_INET:
 561                 size = INADDRSZ;
 562                 break;
 563         case AF_INET6:
 564                 size = IN6ADDRSZ;
 565                 break;
 566         default:
 567                 h_errno = NETDB_INTERNAL;
 568                 errno = EAFNOSUPPORT;
 569                 return NULL;
 570         }
 571
 572         host.h_addrtype = af;
 573         host.h_length = size;
 574
 575         /*
 576          * if there aren't any dots, it could be a user-level alias.
 577          * this is also done in res_nquery() since we are not the only
 578          * function that looks up host names.
 579          */
 580         if (!strchr(name, '.') && (cp = __hostalias(name)))
 581                 name = cp;
 582
 583         /*
 584          * disallow names consisting only of digits/dots, unless
 585          * they end in a dot.
 586          */
 587         if (isdigit((u_char) name[0]))
 588                 for (cp = name;; ++cp) {
 589                         if (!*cp) {
 590                                 if (*--cp == '.')
 591                                         break;
 592                                 /*
 593                                  * All-numeric, no dot at the end.
 594                                  * Fake up a hostent as if we'd actually
 595                                  * done a lookup.
 596                                  */
 597                                 if (inet_pton(af, name,
 598                                     (char *)(void *)host_addr) <= 0) {
 599                                         h_errno = HOST_NOT_FOUND;
 600                                         return NULL;
 601                                 }
 602                                 strncpy(hostbuf, name, MAXDNAME);
 603                                 hostbuf[MAXDNAME] = '\0';
 604                                 bp = hostbuf + MAXDNAME;
 605                                 ep = hostbuf + sizeof hostbuf;
 606                                 host.h_name = hostbuf;
 607                                 host.h_aliases = host_aliases;
 608                                 host_aliases[0] = NULL;
 609                                 h_addr_ptrs[0] = (char *)(void *)host_addr;
 610                                 h_addr_ptrs[1] = NULL;
 611                                 host.h_addr_list = h_addr_ptrs;
 612                                 if (res->options & RES_USE_INET6)
 613                                         map_v4v6_hostent(&host, &bp, ep);
 614                                 h_errno = NETDB_SUCCESS;
 615                                 return &host;
 616                         }
 617                         if (!isdigit((u_char) *cp) && *cp != '.')
 618                                 break;
 619                 }
 620         if ((isxdigit((u_char) name[0]) && strchr(name, ':') != NULL) ||
 621             name[0] == ':')
 622                 for (cp = name;; ++cp) {
 623                         if (!*cp) {
 624                                 if (*--cp == '.')
 625                                         break;
 626                                 /*
 627                                  * All-IPv6-legal, no dot at the end.
 628                                  * Fake up a hostent as if we'd actually
 629                                  * done a lookup.
 630                                  */
 631                                 if (inet_pton(af, name,
 632                                     (char *)(void *)host_addr) <= 0) {
 633                                         h_errno = HOST_NOT_FOUND;
 634                                         return NULL;
 635                                 }
 636                                 strncpy(hostbuf, name, MAXDNAME);
 637                                 hostbuf[MAXDNAME] = '\0';
 638                                 bp = hostbuf + MAXDNAME;
 639                                 ep = hostbuf + sizeof hostbuf;
 640                                 host.h_name = hostbuf;
 641                                 host.h_aliases = host_aliases;
 642                                 host_aliases[0] = NULL;
 643                                 h_addr_ptrs[0] = (char *)(void *)host_addr;
 644                                 h_addr_ptrs[1] = NULL;
 645                                 host.h_addr_list = h_addr_ptrs;
 646                                 h_errno = NETDB_SUCCESS;
 647                                 return &host;
 648                         }
 649                         if (!isxdigit((u_char) *cp) && *cp != ':' && *cp != '.')
 650                                 break;
 651                 }
 652
 653         hp = NULL;
 654         h_errno = NETDB_INTERNAL;
 655         if (nsdispatch(&hp, dtab, NSDB_HOSTS, "gethostbyname",
 656             default_dns_files, name, strlen(name), af) != NS_SUCCESS)
 657                 return NULL;
 658         h_errno = NETDB_SUCCESS;
 659         return hp;
 660 }
 661
 662 struct hostent *
 663 gethostbyaddr(const char *addr, /* XXX should have been def'd as u_char! */
 664     socklen_t len, int af)
 665 {
 666         const u_char *uaddr = (const u_char *)addr;
 667         socklen_t size;
 668         struct hostent *hp;
 669         static const ns_dtab dtab[] = {
 670                 NS_FILES_CB(_gethtbyaddr, NULL)
 671                 { NSSRC_DNS, _dns_gethtbyaddr, NULL },  /* force -DHESIOD */
 672                 NS_NIS_CB(_yp_gethtbyaddr, NULL)
 673                 NS_NULL_CB
 674         };
 675
 676         _DIAGASSERT(addr != NULL);
 677
 678         if (af == AF_INET6 && len == IN6ADDRSZ &&
 679             (IN6_IS_ADDR_LINKLOCAL((const struct in6_addr *)(const void *)uaddr) ||
 680              IN6_IS_ADDR_SITELOCAL((const struct in6_addr *)(const void *)uaddr))) {
 681                 h_errno = HOST_NOT_FOUND;
 682                 return NULL;
 683         }
 684         if (af == AF_INET6 && len == IN6ADDRSZ &&
 685             (IN6_IS_ADDR_V4MAPPED((const struct in6_addr *)(const void *)uaddr) ||
 686              IN6_IS_ADDR_V4COMPAT((const struct in6_addr *)(const void *)uaddr))) {
 687                 /* Unmap. */
 688                 addr += IN6ADDRSZ - INADDRSZ;
 689                 uaddr += IN6ADDRSZ - INADDRSZ;
 690                 af = AF_INET;
 691                 len = INADDRSZ;
 692         }
 693         switch (af) {
 694         case AF_INET:
 695                 size = INADDRSZ;
 696                 break;
 697         case AF_INET6:
 698                 size = IN6ADDRSZ;
 699                 break;
 700         default:
 701                 errno = EAFNOSUPPORT;
 702                 h_errno = NETDB_INTERNAL;
 703                 return NULL;
 704         }
 705         if (size != len) {
 706                 errno = EINVAL;
 707                 h_errno = NETDB_INTERNAL;
 708                 return NULL;
 709         }
 710         hp = NULL;
 711         h_errno = NETDB_INTERNAL;
 712         if (nsdispatch(&hp, dtab, NSDB_HOSTS, "gethostbyaddr",
 713             default_dns_files, uaddr, len, af) != NS_SUCCESS)
 714                 return NULL;
 715         h_errno = NETDB_SUCCESS;
 716         return hp;
 717 }
 718
 719 void
 720 _sethtent(int f)
 721 {
 722         if (!hostf)
 723                 hostf = fopen(_PATH_HOSTS, "r" );
 724         else
 725                 rewind(hostf);
 726         stayopen = f;
 727 }
 728
 729 void
 730 _endhtent(void)
 731 {
 732         if (hostf && !stayopen) {
 733                 (void) fclose(hostf);
 734                 hostf = NULL;
 735         }
 736 }
 737
 738 struct hostent *
 739 _gethtent(void)
 740 {
 741         char *p;
 742         char *cp, **q;
 743         int af, len;
 744
 745         if (!hostf && !(hostf = fopen(_PATH_HOSTS, "r" ))) {
 746                 h_errno = NETDB_INTERNAL;
 747                 return NULL;
 748         }
 749  again:
 750         if (!(p = fgets(hostbuf, sizeof hostbuf, hostf))) {
 751                 h_errno = HOST_NOT_FOUND;
 752                 return NULL;
 753         }
 754         if (*p == '#')
 755                 goto again;
 756         if (!(cp = strpbrk(p, "#\n")))
 757                 goto again;
 758         *cp = '\0';
 759         if (!(cp = strpbrk(p, " \t")))
 760                 goto again;
 761         *cp++ = '\0';
 762         if (inet_pton(AF_INET6, p, (char *)(void *)host_addr) > 0) {
 763                 af = AF_INET6;
 764                 len = IN6ADDRSZ;
 765         } else if (inet_pton(AF_INET, p, (char *)(void *)host_addr) > 0) {
 766                 res_state res = __res_get_state();
 767                 if (res == NULL)
 768                         return NULL;
 769                 if (res->options & RES_USE_INET6) {
 770                         map_v4v6_address((char *)(void *)host_addr,
 771                             (char *)(void *)host_addr);
 772                         af = AF_INET6;
 773                         len = IN6ADDRSZ;
 774                 } else {
 775                         af = AF_INET;
 776                         len = INADDRSZ;
 777                 }
 778                 __res_put_state(res);
 779         } else {
 780                 goto again;
 781         }
 782         /* if this is not something we're looking for, skip it. */
 783         if (host.h_addrtype != 0 && host.h_addrtype != af)
 784                 goto again;
 785         if (host.h_length != 0 && host.h_length != len)
 786                 goto again;
 787         h_addr_ptrs[0] = (char *)(void *)host_addr;
 788         h_addr_ptrs[1] = NULL;
 789         host.h_addr_list = h_addr_ptrs;
 790         host.h_length = len;
 791         host.h_addrtype = af;
 792         while (*cp == ' ' || *cp == '\t')
 793                 cp++;
 794         host.h_name = cp;
 795         q = host.h_aliases = host_aliases;
 796         if ((cp = strpbrk(cp, " \t")) != NULL)
 797                 *cp++ = '\0';
 798         while (cp && *cp) {
 799                 if (*cp == ' ' || *cp == '\t') {
 800                         cp++;
 801                         continue;
 802                 }
 803                 if (q < &host_aliases[MAXALIASES - 1])
 804                         *q++ = cp;
 805                 if ((cp = strpbrk(cp, " \t")) != NULL)
 806                         *cp++ = '\0';
 807         }
 808         *q = NULL;
 809         h_errno = NETDB_SUCCESS;
 810         return &host;
 811 }
 812
 813 /*ARGSUSED*/
 814 int
 815 _gethtbyname(void *rv, void *cb_data, va_list ap)
 816 {
 817         struct hostent *hp;
 818         const char *name;
 819         int af;
 820
 821         _DIAGASSERT(rv != NULL);
 822
 823         name = va_arg(ap, char *);
 824         /* NOSTRICT skip len */(void)va_arg(ap, int);
 825         af = va_arg(ap, int);
 826
 827         hp = NULL;
 828 #if 0
 829         {
 830                 res_state res = __res_get_state();
 831                 if (res == NULL)
 832                         return NS_NOTFOUND;
 833                 if (res->options & RES_USE_INET6)
 834                         hp = _gethtbyname2(name, AF_INET6);
 835                 if (hp==NULL)
 836                         hp = _gethtbyname2(name, AF_INET);
 837                 __res_put_state(res);
 838         }
 839 #else
 840         hp = _gethtbyname2(name, af);
 841 #endif
 842         *((struct hostent **)rv) = hp;
 843         if (hp == NULL) {
 844                 h_errno = HOST_NOT_FOUND;
 845                 return NS_NOTFOUND;
 846         }
 847         return NS_SUCCESS;
 848 }
 849
 850 struct hostent *
 851 _gethtbyname2(const char *name, int af)
 852 {
 853         struct hostent *p;
 854         char *tmpbuf, *ptr, **cp;
 855         int num;
 856         size_t len;
 857
 858         _DIAGASSERT(name != NULL);
 859
 860         _sethtent(stayopen);
 861         ptr = tmpbuf = NULL;
 862         num = 0;
 863         while ((p = _gethtent()) != NULL && num < MAXADDRS) {
 864                 if (p->h_addrtype != af)
 865                         continue;
 866                 if (strcasecmp(p->h_name, name) != 0) {
 867                         for (cp = p->h_aliases; *cp != NULL; cp++)
 868                                 if (strcasecmp(*cp, name) == 0)
 869                                         break;
 870                         if (*cp == NULL) continue;
 871                 }
 872
 873                 if (num == 0) {
 874                         size_t bufsize;
 875                         char *src;
 876
 877                         bufsize = strlen(p->h_name) + 2 +
 878                                   MAXADDRS * p->h_length +
 879                                   ALIGNBYTES;
 880                         for (cp = p->h_aliases; *cp != NULL; cp++)
 881                                 bufsize += strlen(*cp) + 1;
 882
 883                         if ((tmpbuf = malloc(bufsize)) == NULL) {
 884                                 h_errno = NETDB_INTERNAL;
 885                                 return NULL;
 886                         }
 887
 888                         ptr = tmpbuf;
 889                         src = p->h_name;
 890                         while ((*ptr++ = *src++) != '\0');
 891                         for (cp = p->h_aliases; *cp != NULL; cp++) {
 892                                 src = *cp;
 893                                 while ((*ptr++ = *src++) != '\0');
 894                         }
 895                         *ptr++ = '\0';
 896
 897                         ptr = (char *)(void *)ALIGN(ptr);
 898                 }
 899
 900                 (void)memcpy(ptr, p->h_addr_list[0], (size_t)p->h_length);
 901                 ptr += p->h_length;
 902                 num++;
 903         }
 904         _endhtent();
 905         if (num == 0) return NULL;
 906
 907         len = ptr - tmpbuf;
 908         if (len > (sizeof(hostbuf) - ALIGNBYTES)) {
 909                 free(tmpbuf);
 910                 errno = ENOSPC;
 911                 h_errno = NETDB_INTERNAL;
 912                 return NULL;
 913         }
 914         ptr = memcpy((void *)ALIGN(hostbuf), tmpbuf, len);
 915         free(tmpbuf);
 916
 917         host.h_name = ptr;
 918         while (*ptr++);
 919
 920         cp = host_aliases;
 921         while (*ptr) {
 922                 *cp++ = ptr;
 923                 while (*ptr++);
 924         }
 925         ptr++;
 926         *cp = NULL;
 927
 928         ptr = (char *)(void *)ALIGN(ptr);
 929         cp = h_addr_ptrs;
 930         while (num--) {
 931                 *cp++ = ptr;
 932                 ptr += host.h_length;
 933         }
 934         *cp = NULL;
 935
 936         return &host;
 937 }
 938
 939 /*ARGSUSED*/
 940 int
 941 _gethtbyaddr(void *rv, void *cb_data, va_list ap)
 942 {
 943         struct hostent *p;
 944         const unsigned char *addr;
 945         int len, af;
 946
 947         _DIAGASSERT(rv != NULL);
 948
 949         addr = va_arg(ap, unsigned char *);
 950         len = va_arg(ap, int);
 951         af = va_arg(ap, int);
 952
 953         host.h_length = len;
 954         host.h_addrtype = af;
 955
 956         _sethtent(stayopen);
 957         while ((p = _gethtent()) != NULL)
 958                 if (p->h_addrtype == af && !memcmp(p->h_addr, addr,
 959                     (size_t)len))
 960                         break;
 961         _endhtent();
 962         *((struct hostent **)rv) = p;
 963         if (p==NULL) {
 964                 h_errno = HOST_NOT_FOUND;
 965                 return NS_NOTFOUND;
 966         }
 967         return NS_SUCCESS;
 968 }
 969
 970 static void
 971 map_v4v6_address(const char *src, char *dst)
 972 {
 973         u_char *p = (u_char *)dst;
 974         char tmp[INADDRSZ];
 975         int i;
 976
 977         _DIAGASSERT(src != NULL);
 978         _DIAGASSERT(dst != NULL);
 979
 980         /* Stash a temporary copy so our caller can update in place. */
 981         (void)memcpy(tmp, src, INADDRSZ);
 982         /* Mark this ipv6 addr as a mapped ipv4. */
 983         for (i = 0; i < 10; i++)
 984                 *p++ = 0x00;
 985         *p++ = 0xff;
 986         *p++ = 0xff;
 987         /* Retrieve the saved copy and we're done. */
 988         (void)memcpy((void *)p, tmp, INADDRSZ);
 989 }
 990
 991 static void
 992 map_v4v6_hostent(struct hostent *hp, char **bpp, char *ep)
 993 {
 994         char **ap;
 995
 996         _DIAGASSERT(hp != NULL);
 997         _DIAGASSERT(bpp != NULL);
 998         _DIAGASSERT(ep != NULL);
 999
1000         if (hp->h_addrtype != AF_INET || hp->h_length != INADDRSZ)
1001                 return;
1002         hp->h_addrtype = AF_INET6;
1003         hp->h_length = IN6ADDRSZ;
1004         for (ap = hp->h_addr_list; *ap; ap++) {
1005                 int i = sizeof(align) - (size_t)((u_long)*bpp % sizeof(align));
1006
1007                 if (ep - *bpp < (i + IN6ADDRSZ)) {
1008                         /* Out of memory.  Truncate address list here.  XXX */
1009                         *ap = NULL;
1010                         return;
1011                 }
1012                 *bpp += i;
1013                 map_v4v6_address(*ap, *bpp);
1014                 *ap = *bpp;
1015                 *bpp += IN6ADDRSZ;
1016         }
1017 }
1018
1019 static void
1020 addrsort(char **ap, int num, res_state res)
1021 {
1022         int i, j;
1023         char **p;
1024         short aval[MAXADDRS];
1025         int needsort = 0;
1026
1027         _DIAGASSERT(ap != NULL);
1028
1029         p = ap;
1030         for (i = 0; i < num; i++, p++) {
1031             for (j = 0 ; (unsigned)j < res->nsort; j++)
1032                 if (res->sort_list[j].addr.s_addr ==
1033                     (((struct in_addr *)(void *)(*p))->s_addr &
1034                     res->sort_list[j].mask))
1035                         break;
1036             aval[i] = j;
1037             if (needsort == 0 && i > 0 && j < aval[i-1])
1038                 needsort = i;
1039         }
1040         if (!needsort)
1041             return;
1042
1043         while (needsort < num) {
1044             for (j = needsort - 1; j >= 0; j--) {
1045                 if (aval[j] > aval[j+1]) {
1046                     char *hp;
1047
1048                     i = aval[j];
1049                     aval[j] = aval[j+1];
1050                     aval[j+1] = i;
1051
1052                     hp = ap[j];
1053                     ap[j] = ap[j+1];
1054                     ap[j+1] = hp;
1055                 } else
1056                     break;
1057             }
1058             needsort++;
1059         }
1060 }
1061
1062 struct hostent *
1063 gethostent(void)
1064 {
1065         host.h_addrtype = 0;
1066         host.h_length = 0;
1067         return _gethtent();
1068 }
1069
1070 /*ARGSUSED*/
1071 int
1072 _dns_gethtbyname(void *rv, void *cb_data, va_list ap)
1073 {
1074         querybuf *buf;
1075         int n, type;
1076         struct hostent *hp;
1077         const char *name;
1078         int af;
1079         res_state res;
1080
1081         _DIAGASSERT(rv != NULL);
1082
1083         name = va_arg(ap, char *);
1084         /* NOSTRICT skip len */(void)va_arg(ap, int);
1085         af = va_arg(ap, int);
1086
1087         switch (af) {
1088         case AF_INET:
1089                 type = T_A;
1090                 break;
1091         case AF_INET6:
1092                 type = T_AAAA;
1093                 break;
1094         default:
1095                 return NS_UNAVAIL;
1096         }
1097         buf = malloc(sizeof(*buf));
1098         if (buf == NULL) {
1099                 h_errno = NETDB_INTERNAL;
1100                 return NS_NOTFOUND;
1101         }
1102         res = __res_get_state();
1103         if (res == NULL) {
1104                 free(buf);
1105                 return NS_NOTFOUND;
1106         }
1107         n = res_nsearch(res, name, C_IN, type, buf->buf, sizeof(buf->buf));
1108         if (n < 0) {
1109                 free(buf);
1110                 dprintf("res_nsearch failed (%d)\n", res, n);
1111                 __res_put_state(res);
1112                 return NS_NOTFOUND;
1113         }
1114         hp = getanswer(buf, n, name, type, res);
1115         free(buf);
1116         __res_put_state(res);
1117         if (hp == NULL)
1118                 switch (h_errno) {
1119                 case HOST_NOT_FOUND:
1120                         return NS_NOTFOUND;
1121                 case TRY_AGAIN:
1122                         return NS_TRYAGAIN;
1123                 default:
1124                         return NS_UNAVAIL;
1125                 }
1126         *((struct hostent **)rv) = hp;
1127         return NS_SUCCESS;
1128 }
1129
1130 /*ARGSUSED*/
1131 int
1132 _dns_gethtbyaddr(void *rv, void *cb_data, va_list ap)
1133 {
1134         char qbuf[MAXDNAME + 1], *qp, *ep;
1135         int n;
1136         querybuf *buf;
1137         struct hostent *hp;
1138         const unsigned char *uaddr;
1139         int len, af, advance;
1140         res_state res;
1141
1142         _DIAGASSERT(rv != NULL);
1143
1144         uaddr = va_arg(ap, unsigned char *);
1145         len = va_arg(ap, int);
1146         af = va_arg(ap, int);
1147
1148         switch (af) {
1149         case AF_INET:
1150                 (void)snprintf(qbuf, sizeof(qbuf), "%u.%u.%u.%u.in-addr.arpa",
1151                     (uaddr[3] & 0xff), (uaddr[2] & 0xff),
1152                     (uaddr[1] & 0xff), (uaddr[0] & 0xff));
1153                 break;
1154
1155         case AF_INET6:
1156                 qp = qbuf;
1157                 ep = qbuf + sizeof(qbuf) - 1;
1158                 for (n = IN6ADDRSZ - 1; n >= 0; n--) {
1159                         advance = snprintf(qp, (size_t)(ep - qp), "%x.%x.",
1160                             uaddr[n] & 0xf,
1161                             ((unsigned int)uaddr[n] >> 4) & 0xf);
1162                         if (advance > 0 && qp + advance < ep)
1163                                 qp += advance;
1164                         else {
1165                                 h_errno = NETDB_INTERNAL;
1166                                 return NS_NOTFOUND;
1167                         }
1168                 }
1169                 if (strlcat(qbuf, "ip6.arpa", sizeof(qbuf)) >= sizeof(qbuf)) {
1170                         h_errno = NETDB_INTERNAL;
1171                         return NS_NOTFOUND;
1172                 }
1173                 break;
1174         default:
1175                 abort();
1176         }
1177
1178         buf = malloc(sizeof(*buf));
1179         if (buf == NULL) {
1180                 h_errno = NETDB_INTERNAL;
1181                 return NS_NOTFOUND;
1182         }
1183         res = __res_get_state();
1184         if (res == NULL) {
1185                 free(buf);
1186                 return NS_NOTFOUND;
1187         }
1188         n = res_nquery(res, qbuf, C_IN, T_PTR, buf->buf, sizeof(buf->buf));
1189         if (n < 0) {
1190                 free(buf);
1191                 dprintf("res_nquery failed (%d)\n", res, n);
1192                 __res_put_state(res);
1193                 return NS_NOTFOUND;
1194         }
1195         hp = getanswer(buf, n, qbuf, T_PTR, res);
1196         free(buf);
1197         if (hp == NULL) {
1198                 __res_put_state(res);
1199                 switch (h_errno) {
1200                 case HOST_NOT_FOUND:
1201                         return NS_NOTFOUND;
1202                 case TRY_AGAIN:
1203                         return NS_TRYAGAIN;
1204                 default:
1205                         return NS_UNAVAIL;
1206                 }
1207         }
1208         hp->h_addrtype = af;
1209         hp->h_length = len;
1210         (void)memcpy(host_addr, uaddr, (size_t)len);
1211         h_addr_ptrs[0] = (char *)(void *)host_addr;
1212         h_addr_ptrs[1] = NULL;
1213         if (af == AF_INET && (res->options & RES_USE_INET6)) {
1214                 map_v4v6_address((char *)(void *)host_addr,
1215                     (char *)(void *)host_addr);
1216                 hp->h_addrtype = AF_INET6;
1217                 hp->h_length = IN6ADDRSZ;
1218         }
1219
1220         __res_put_state(res);
1221         *((struct hostent **)rv) = hp;
1222         h_errno = NETDB_SUCCESS;
1223         return NS_SUCCESS;
1224 }
1225
1226 #ifdef YP
1227 /*ARGSUSED*/
1228 struct hostent *
1229 _yphostent(char *line, int af)
1230 {
1231         static struct in_addr host_addrs[MAXADDRS];
1232         static struct in6_addr host6_addrs[MAXADDRS];
1233         char *p = line;
1234         char *cp, **q;
1235         char **hap;
1236         int addrok;
1237         int more;
1238         size_t naddrs;
1239
1240         _DIAGASSERT(line != NULL);
1241
1242         host.h_name = NULL;
1243         host.h_addr_list = h_addr_ptrs;
1244         host.h_addrtype = af;
1245         switch (af) {
1246         case AF_INET:
1247                 host.h_length = INADDRSZ;
1248                 break;
1249         case AF_INET6:
1250                 host.h_length = IN6ADDRSZ;
1251                 break;
1252         default:
1253                 return NULL;
1254         }
1255         hap = h_addr_ptrs;
1256         q = host.h_aliases = host_aliases;
1257         naddrs = 0;
1258
1259 nextline:
1260         /* check for host_addrs overflow */
1261         if (naddrs >= sizeof(host_addrs) / sizeof(host_addrs[0]))
1262                 goto done;
1263         if (naddrs >= sizeof(host6_addrs) / sizeof(host6_addrs[0]))
1264                 goto done;
1265
1266         more = 0;
1267         cp = strpbrk(p, " \t");
1268         if (cp == NULL)
1269                 goto done;
1270         *cp++ = '\0';
1271
1272         /* p has should have an address */
1273         addrok = 0;
1274         switch (af) {
1275         case AF_INET:
1276                 addrok = inet_aton(p, &host_addrs[naddrs]);
1277                 break;
1278         case AF_INET6:
1279                 addrok = inet_pton(af, p, &host6_addrs[naddrs]);
1280                 break;
1281         }
1282         if (addrok != 1) {
1283                 /* skip to the next line */
1284                 while (cp && *cp) {
1285                         if (*cp == '\n') {
1286                                 cp++;
1287                                 goto nextline;
1288                         }
1289                         cp++;
1290                 }
1291
1292                 goto done;
1293         }
1294
1295         switch (af) {
1296         case AF_INET:
1297                 *hap++ = (char *)(void *)&host_addrs[naddrs++];
1298                 break;
1299         case AF_INET6:
1300                 *hap++ = (char *)(void *)&host6_addrs[naddrs++];
1301                 break;
1302         }
1303
1304         while (*cp == ' ' || *cp == '\t')
1305                 cp++;
1306         p = cp;
1307         cp = strpbrk(p, " \t\n");
1308         if (cp != NULL) {
1309                 if (*cp == '\n')
1310                         more = 1;
1311                 *cp++ = '\0';
1312         }
1313         if (!host.h_name)
1314                 host.h_name = p;
1315         else if (strcmp(host.h_name, p)==0)
1316                 ;
1317         else if (q < &host_aliases[MAXALIASES - 1])
1318                 *q++ = p;
1319         p = cp;
1320         if (more)
1321                 goto nextline;
1322
1323         while (cp && *cp) {
1324                 if (*cp == ' ' || *cp == '\t') {
1325                         cp++;
1326                         continue;
1327                 }
1328                 if (*cp == '\n') {
1329                         cp++;
1330                         goto nextline;
1331                 }
1332                 if (q < &host_aliases[MAXALIASES - 1])
1333                         *q++ = cp;
1334                 cp = strpbrk(cp, " \t");
1335                 if (cp != NULL)
1336                         *cp++ = '\0';
1337         }
1338
1339 done:
1340         if (host.h_name == NULL)
1341                 return NULL;
1342         *q = NULL;
1343         *hap = NULL;
1344         return &host;
1345 }
1346
1347 /*ARGSUSED*/
1348 int
1349 _yp_gethtbyaddr(void *rv, void *cb_data, va_list ap)
1350 {
1351         struct hostent *hp = NULL;
1352         static char *__ypcurrent;
1353         int __ypcurrentlen, r;
1354         char name[INET6_ADDRSTRLEN];    /* XXX enough? */
1355         const unsigned char *uaddr;
1356         int af;
1357         const char *map;
1358
1359         _DIAGASSERT(rv != NULL);
1360
1361         uaddr = va_arg(ap, unsigned char *);
1362         /* NOSTRICT skip len */(void)va_arg(ap, int);
1363         af = va_arg(ap, int);
1364
1365         if (!__ypdomain) {
1366                 if (_yp_check(&__ypdomain) == 0)
1367                         return NS_UNAVAIL;
1368         }
1369         /*
1370          * XXX unfortunately, we cannot support IPv6 extended scoped address
1371          * notation here.  gethostbyaddr() is not scope-aware.  too bad.
1372          */
1373         if (inet_ntop(af, uaddr, name, sizeof(name)) == NULL)
1374                 return NS_UNAVAIL;
1375         if (__ypcurrent)
1376                 free(__ypcurrent);
1377         __ypcurrent = NULL;
1378         switch (af) {
1379         case AF_INET:
1380                 map = "hosts.byaddr";
1381                 break;
1382         default:
1383                 map = "ipnodes.byaddr";
1384                 break;
1385         }
1386         r = yp_match(__ypdomain, map, name,
1387                 (int)strlen(name), &__ypcurrent, &__ypcurrentlen);
1388         if (r == 0)
1389                 hp = _yphostent(__ypcurrent, af);
1390         if (hp == NULL) {
1391                 h_errno = HOST_NOT_FOUND;
1392                 return NS_NOTFOUND;
1393         }
1394         *((struct hostent **)rv) = hp;
1395         return NS_SUCCESS;
1396 }
1397
1398 /*ARGSUSED*/
1399 int
1400 _yp_gethtbyname(void *rv, void *cb_data, va_list ap)
1401 {
1402         struct hostent *hp = NULL;
1403         static char *__ypcurrent;
1404         int __ypcurrentlen, r;
1405         const char *name;
1406         int af;
1407         const char *map;
1408
1409         _DIAGASSERT(rv != NULL);
1410
1411         name = va_arg(ap, char *);
1412         /* NOSTRICT skip len */(void)va_arg(ap, int);
1413         af = va_arg(ap, int);
1414
1415         if (!__ypdomain) {
1416                 if (_yp_check(&__ypdomain) == 0)
1417                         return NS_UNAVAIL;
1418         }
1419         if (__ypcurrent)
1420                 free(__ypcurrent);
1421         __ypcurrent = NULL;
1422         switch (af) {
1423         case AF_INET:
1424                 map = "hosts.byname";
1425                 break;
1426         default:
1427                 map = "ipnodes.byname";
1428                 break;
1429         }
1430         r = yp_match(__ypdomain, map, name,
1431                 (int)strlen(name), &__ypcurrent, &__ypcurrentlen);
1432         if (r == 0)
1433                 hp = _yphostent(__ypcurrent, af);
1434         if (hp == NULL) {
1435                 h_errno = HOST_NOT_FOUND;
1436                 return NS_NOTFOUND;
1437         }
1438         *((struct hostent **)rv) = hp;
1439         return NS_SUCCESS;
1440 }
1441 #endif