contrib/bind-9.5.2/lib/bind/irs/lcl_ho.c

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