usr/src/lib/libresolv2/common/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 /* Imports. */
  55
  56 #include "port_before.h"
  57
  58 #include <sys/types.h>
  59 #include <sys/param.h>
  60 #include <sys/socket.h>
  61
  62 #include <netinet/in.h>
  63 #include <arpa/inet.h>
  64 #include <arpa/nameser.h>
  65
  66 #include <ctype.h>
  67 #include <errno.h>
  68 #include <fcntl.h>
  69 #include <netdb.h>
  70 #include <resolv.h>
  71 #include <stdio.h>
  72 #include <stdlib.h>
  73 #include <string.h>
  74
  75 #include <irs.h>
  76 #include <isc/memcluster.h>
  77
  78 #include "port_after.h"
  79
  80 #include "irs_p.h"
  81 #include "dns_p.h"
  82 #include "lcl_p.h"
  83
  84 #ifdef SPRINTF_CHAR
  85 # define SPRINTF(x) strlen(sprintf/**/x)
  86 #else
  87 # define SPRINTF(x) sprintf x
  88 #endif
  89
  90 /* Definitions. */
  91
  92 #define MAXALIASES      35
  93 #define MAXADDRS        35
  94 #define Max(a,b)        ((a) > (b) ? (a) : (b))
  95
  96 #if PACKETSZ > 1024
  97 #define MAXPACKET       PACKETSZ
  98 #else
  99 #define MAXPACKET       1024
 100 #endif
 101
 102 struct pvt {
 103         FILE *          fp;
 104         struct hostent  host;
 105         char *          h_addr_ptrs[MAXADDRS + 1];
 106         char *          host_aliases[MAXALIASES];
 107         char            hostbuf[8*1024];
 108         u_char          host_addr[16];  /*%< IPv4 or IPv6 */
 109         struct __res_state  *res;
 110         void            (*free_res)(void *);
 111 };
 112
 113 typedef union {
 114         int32_t al;
 115         char ac;
 116 } align;
 117
 118 static const u_char mapped[] = { 0,0, 0,0, 0,0, 0,0, 0,0, 0xff,0xff };
 119 static const u_char tunnelled[] = { 0,0, 0,0, 0,0, 0,0, 0,0, 0,0 };
 120
 121 /* Forward. */
 122
 123 static void             ho_close(struct irs_ho *this);
 124 static struct hostent * ho_byname(struct irs_ho *this, const char *name);
 125 static struct hostent * ho_byname2(struct irs_ho *this, const char *name,
 126                                    int af);
 127 static struct hostent * ho_byaddr(struct irs_ho *this, const void *addr,
 128                                   int len, int af);
 129 static struct hostent * ho_next(struct irs_ho *this);
 130 static void             ho_rewind(struct irs_ho *this);
 131 static void             ho_minimize(struct irs_ho *this);
 132 static struct __res_state * ho_res_get(struct irs_ho *this);
 133 static void             ho_res_set(struct irs_ho *this,
 134                                    struct __res_state *res,
 135                                    void (*free_res)(void *));
 136 static struct addrinfo * ho_addrinfo(struct irs_ho *this, const char *name,
 137                                      const struct addrinfo *pai);
 138
 139 static size_t           ns_namelen(const char *);
 140 static int              init(struct irs_ho *this);
 141
 142 /* Portability. */
 143
 144 #ifndef SEEK_SET
 145 # define SEEK_SET 0
 146 #endif
 147
 148 /* Public. */
 149
 150 struct irs_ho *
 151 irs_lcl_ho(struct irs_acc *this) {
 152         struct irs_ho *ho;
 153         struct pvt *pvt;
 154
 155         UNUSED(this);
 156
 157         if (!(pvt = memget(sizeof *pvt))) {
 158                 errno = ENOMEM;
 159                 return (NULL);
 160         }
 161         memset(pvt, 0, sizeof *pvt);
 162         if (!(ho = memget(sizeof *ho))) {
 163                 memput(pvt, sizeof *pvt);
 164                 errno = ENOMEM;
 165                 return (NULL);
 166         }
 167         memset(ho, 0x5e, sizeof *ho);
 168         ho->private = pvt;
 169         ho->close = ho_close;
 170         ho->byname = ho_byname;
 171         ho->byname2 = ho_byname2;
 172         ho->byaddr = ho_byaddr;
 173         ho->next = ho_next;
 174         ho->rewind = ho_rewind;
 175         ho->minimize = ho_minimize;
 176         ho->res_get = ho_res_get;
 177         ho->res_set = ho_res_set;
 178         ho->addrinfo = ho_addrinfo;
 179         return (ho);
 180 }
 181
 182 /* Methods. */
 183
 184 static void
 185 ho_close(struct irs_ho *this) {
 186         struct pvt *pvt = (struct pvt *)this->private;
 187
 188         ho_minimize(this);
 189         if (pvt->fp)
 190                 (void) fclose(pvt->fp);
 191         if (pvt->res && pvt->free_res)
 192                 (*pvt->free_res)(pvt->res);
 193         memput(pvt, sizeof *pvt);
 194         memput(this, sizeof *this);
 195 }
 196
 197 static struct hostent *
 198 ho_byname(struct irs_ho *this, const char *name) {
 199         struct pvt *pvt = (struct pvt *)this->private;
 200         struct hostent *hp;
 201
 202         if (init(this) == -1)
 203                 return (NULL);
 204
 205         if (pvt->res->options & RES_USE_INET6) {
 206                 hp = ho_byname2(this, name, AF_INET6);
 207                 if (hp)
 208                         return (hp);
 209         }
 210         return (ho_byname2(this, name, AF_INET));
 211 }
 212
 213 static struct hostent *
 214 ho_byname2(struct irs_ho *this, const char *name, int af) {
 215         struct pvt *pvt = (struct pvt *)this->private;
 216         struct hostent *hp;
 217         char **hap;
 218         size_t n;
 219
 220         if (init(this) == -1)
 221                 return (NULL);
 222
 223         ho_rewind(this);
 224         n = ns_namelen(name);
 225         while ((hp = ho_next(this)) != NULL) {
 226                 size_t nn;
 227
 228                 if (hp->h_addrtype != af)
 229                         continue;
 230                 nn = ns_namelen(hp->h_name);
 231                 if (strncasecmp(hp->h_name, name, Max(n, nn)) == 0)
 232                         goto found;
 233                 for (hap = hp->h_aliases; *hap; hap++) {
 234                         nn = ns_namelen(*hap);
 235                         if (strncasecmp(*hap, name, Max(n, nn)) == 0)
 236                                 goto found;
 237                 }
 238         }
 239  found:
 240         if (!hp) {
 241                 RES_SET_H_ERRNO(pvt->res, HOST_NOT_FOUND);
 242                 return (NULL);
 243         }
 244         RES_SET_H_ERRNO(pvt->res, NETDB_SUCCESS);
 245         return (hp);
 246 }
 247
 248 static struct hostent *
 249 ho_byaddr(struct irs_ho *this, const void *addr, int len, int af) {
 250         struct pvt *pvt = (struct pvt *)this->private;
 251         const u_char *uaddr = addr;
 252         struct hostent *hp;
 253         int size;
 254
 255         if (init(this) == -1)
 256                 return (NULL);
 257
 258         if (af == AF_INET6 && len == IN6ADDRSZ &&
 259             (!memcmp(uaddr, mapped, sizeof mapped) ||
 260              !memcmp(uaddr, tunnelled, sizeof tunnelled))) {
 261                 /* Unmap. */
 262                 addr = (const u_char *)addr + sizeof mapped;
 263                 uaddr += sizeof mapped;
 264                 af = AF_INET;
 265                 len = INADDRSZ;
 266         }
 267         switch (af) {
 268         case AF_INET:
 269                 size = INADDRSZ;
 270                 break;
 271         case AF_INET6:
 272                 size = IN6ADDRSZ;
 273                 break;
 274         default:
 275                 errno = EAFNOSUPPORT;
 276                 RES_SET_H_ERRNO(pvt->res, NETDB_INTERNAL);
 277                 return (NULL);
 278         }
 279         if (size > len) {
 280                 errno = EINVAL;
 281                 RES_SET_H_ERRNO(pvt->res, NETDB_INTERNAL);
 282                 return (NULL);
 283         }
 284
 285         /*
 286          * Do the search.
 287          */
 288         ho_rewind(this);
 289         while ((hp = ho_next(this)) != NULL) {
 290                 char **hap;
 291
 292                 for (hap = hp->h_addr_list; *hap; hap++) {
 293                         const u_char *taddr = (const u_char *)*hap;
 294                         int taf = hp->h_addrtype;
 295                         int tlen = hp->h_length;
 296
 297                         if (taf == AF_INET6 && tlen == IN6ADDRSZ &&
 298                             (!memcmp(taddr, mapped, sizeof mapped) ||
 299                              !memcmp(taddr, tunnelled, sizeof tunnelled))) {
 300                                 /* Unmap. */
 301                                 taddr += sizeof mapped;
 302                                 taf = AF_INET;
 303                                 tlen = INADDRSZ;
 304                         }
 305                         if (taf == af && tlen == len &&
 306                             !memcmp(taddr, uaddr, tlen))
 307                                 goto found;
 308                 }
 309         }
 310  found:
 311         if (!hp) {
 312                 RES_SET_H_ERRNO(pvt->res, HOST_NOT_FOUND);
 313                 return (NULL);
 314         }
 315         RES_SET_H_ERRNO(pvt->res, NETDB_SUCCESS);
 316         return (hp);
 317 }
 318
 319 static struct hostent *
 320 ho_next(struct irs_ho *this) {
 321         struct pvt *pvt = (struct pvt *)this->private;
 322         char *cp, **q, *p;
 323         char *bufp, *ndbuf, *dbuf = NULL;
 324         int c, af, len, bufsiz, offset;
 325
 326         if (init(this) == -1)
 327                 return (NULL);
 328
 329         if (!pvt->fp)
 330                 ho_rewind(this);
 331         if (!pvt->fp) {
 332                 RES_SET_H_ERRNO(pvt->res, NETDB_INTERNAL);
 333                 return (NULL);
 334         }
 335         bufp = pvt->hostbuf;
 336         bufsiz = sizeof pvt->hostbuf;
 337         offset = 0;
 338  again:
 339         if (!(p = fgets(bufp + offset, bufsiz - offset, pvt->fp))) {
 340                 RES_SET_H_ERRNO(pvt->res, HOST_NOT_FOUND);
 341                 free(dbuf);
 342                 return (NULL);
 343         }
 344         if (!strchr(p, '\n') && !feof(pvt->fp)) {
 345 #define GROWBUF 1024
 346                 /* allocate space for longer line */
 347                 if (dbuf == NULL) {
 348                         if ((ndbuf = malloc(bufsiz + GROWBUF)) != NULL)
 349                                 strcpy(ndbuf, bufp);
 350                 } else
 351                         ndbuf = realloc(dbuf, bufsiz + GROWBUF);
 352                 if (ndbuf) {
 353                         dbuf = ndbuf;
 354                         bufp = dbuf;
 355                         bufsiz += GROWBUF;
 356                         offset = strlen(dbuf);
 357                 } else {
 358                         /* allocation failed; skip this long line */
 359                         while ((c = getc(pvt->fp)) != EOF)
 360                                 if (c == '\n')
 361                                         break;
 362                         if (c != EOF)
 363                                 ungetc(c, pvt->fp);
 364                 }
 365                 goto again;
 366         }
 367
 368         p -= offset;
 369         offset = 0;
 370
 371         if (*p == '#')
 372                 goto again;
 373         if ((cp = strpbrk(p, "#\n")) != NULL)
 374                 *cp = '\0';
 375         if (!(cp = strpbrk(p, " \t")))
 376                 goto again;
 377         *cp++ = '\0';
 378         if (inet_pton(AF_INET6, p, pvt->host_addr) > 0) {
 379                 af = AF_INET6;
 380                 len = IN6ADDRSZ;
 381         } else if (inet_aton(p, (struct in_addr *)pvt->host_addr) > 0) {
 382                 if (pvt->res->options & RES_USE_INET6) {
 383                         map_v4v6_address((char*)pvt->host_addr,
 384                                          (char*)pvt->host_addr);
 385                         af = AF_INET6;
 386                         len = IN6ADDRSZ;
 387                 } else {
 388                         af = AF_INET;
 389                         len = INADDRSZ;
 390                 }
 391         } else {
 392                 goto again;
 393         }
 394         pvt->h_addr_ptrs[0] = (char *)pvt->host_addr;
 395         pvt->h_addr_ptrs[1] = NULL;
 396         pvt->host.h_addr_list = pvt->h_addr_ptrs;
 397         pvt->host.h_length = len;
 398         pvt->host.h_addrtype = af;
 399         while (*cp == ' ' || *cp == '\t')
 400                 cp++;
 401         pvt->host.h_name = cp;
 402         q = pvt->host.h_aliases = pvt->host_aliases;
 403         if ((cp = strpbrk(cp, " \t")) != NULL)
 404                 *cp++ = '\0';
 405         while (cp && *cp) {
 406                 if (*cp == ' ' || *cp == '\t') {
 407                         cp++;
 408                         continue;
 409                 }
 410                 if (q < &pvt->host_aliases[MAXALIASES - 1])
 411                         *q++ = cp;
 412                 if ((cp = strpbrk(cp, " \t")) != NULL)
 413                         *cp++ = '\0';
 414         }
 415         *q = NULL;
 416         free(dbuf);
 417         RES_SET_H_ERRNO(pvt->res, NETDB_SUCCESS);
 418         return (&pvt->host);
 419 }
 420
 421 static void
 422 ho_rewind(struct irs_ho *this) {
 423         struct pvt *pvt = (struct pvt *)this->private;
 424
 425         if (pvt->fp) {
 426                 if (fseek(pvt->fp, 0L, SEEK_SET) == 0)
 427                         return;
 428                 (void)fclose(pvt->fp);
 429         }
 430         if (!(pvt->fp = fopen(_PATH_HOSTS, "r")))
 431                 return;
 432         if (fcntl(fileno(pvt->fp), F_SETFD, 1) < 0) {
 433                 (void)fclose(pvt->fp);
 434                 pvt->fp = NULL;
 435         }
 436 }
 437
 438 static void
 439 ho_minimize(struct irs_ho *this) {
 440         struct pvt *pvt = (struct pvt *)this->private;
 441
 442         if (pvt->fp != NULL) {
 443                 (void)fclose(pvt->fp);
 444                 pvt->fp = NULL;
 445         }
 446         if (pvt->res)
 447                 res_nclose(pvt->res);
 448 }
 449
 450 static struct __res_state *
 451 ho_res_get(struct irs_ho *this) {
 452         struct pvt *pvt = (struct pvt *)this->private;
 453
 454         if (!pvt->res) {
 455                 struct __res_state *res;
 456                 res = (struct __res_state *)malloc(sizeof *res);
 457                 if (!res) {
 458                         errno = ENOMEM;
 459                         return (NULL);
 460                 }
 461                 memset(res, 0, sizeof *res);
 462                 ho_res_set(this, res, free);
 463         }
 464
 465         return (pvt->res);
 466 }
 467
 468 static void
 469 ho_res_set(struct irs_ho *this, struct __res_state *res,
 470                 void (*free_res)(void *)) {
 471         struct pvt *pvt = (struct pvt *)this->private;
 472
 473         if (pvt->res && pvt->free_res) {
 474                 res_nclose(pvt->res);
 475                 (*pvt->free_res)(pvt->res);
 476         }
 477
 478         pvt->res = res;
 479         pvt->free_res = free_res;
 480 }
 481
 482 struct lcl_res_target {
 483         struct lcl_res_target *next;
 484         int family;
 485 };
 486
 487 /* XXX */
 488 extern struct addrinfo *hostent2addrinfo __P((struct hostent *,
 489                                               const struct addrinfo *pai));
 490
 491 static struct addrinfo *
 492 ho_addrinfo(struct irs_ho *this, const char *name, const struct addrinfo *pai)
 493 {
 494         struct pvt *pvt = (struct pvt *)this->private;
 495         struct hostent *hp;
 496         struct lcl_res_target q, q2, *p;
 497         struct addrinfo sentinel, *cur;
 498
 499         memset(&q, 0, sizeof(q2));
 500         memset(&q2, 0, sizeof(q2));
 501         memset(&sentinel, 0, sizeof(sentinel));
 502         cur = &sentinel;
 503
 504         switch(pai->ai_family) {
 505         case AF_UNSPEC:         /*%< INET6 then INET4 */
 506                 q.family = AF_INET6;
 507                 q.next = &q2;
 508                 q2.family = AF_INET;
 509                 break;
 510         case AF_INET6:
 511                 q.family = AF_INET6;
 512                 break;
 513         case AF_INET:
 514                 q.family = AF_INET;
 515                 break;
 516         default:
 517                 RES_SET_H_ERRNO(pvt->res, NO_RECOVERY); /*%< ??? */
 518                 return(NULL);
 519         }
 520
 521         for (p = &q; p; p = p->next) {
 522                 struct addrinfo *ai;
 523
 524                 hp = (*this->byname2)(this, name, p->family);
 525                 if (hp == NULL) {
 526                         /* byname2 should've set an appropriate error */
 527                         continue;
 528                 }
 529                 if ((hp->h_name == NULL) || (hp->h_name[0] == 0) ||
 530                     (hp->h_addr_list[0] == NULL)) {
 531                         RES_SET_H_ERRNO(pvt->res, NO_RECOVERY);
 532                         continue;
 533                 }
 534
 535                 ai = hostent2addrinfo(hp, pai);
 536                 if (ai) {
 537                         cur->ai_next = ai;
 538                         while (cur->ai_next)
 539                                 cur = cur->ai_next;
 540                 }
 541         }
 542
 543         if (sentinel.ai_next == NULL)
 544                 RES_SET_H_ERRNO(pvt->res, HOST_NOT_FOUND);
 545
 546         return(sentinel.ai_next);
 547 }
 548
 549 /* Private. */
 550
 551 static size_t
 552 ns_namelen(const char *s) {
 553         int i;
 554
 555         for (i = strlen(s); i > 0 && s[i-1] == '.'; i--)
 556                 (void)NULL;
 557         return ((size_t) i);
 558 }
 559
 560 static int
 561 init(struct irs_ho *this) {
 562         struct pvt *pvt = (struct pvt *)this->private;
 563
 564         if (!pvt->res && !ho_res_get(this))
 565                 return (-1);
 566         if (((pvt->res->options & RES_INIT) == 0U) &&
 567             res_ninit(pvt->res) == -1)
 568                 return (-1);
 569         return (0);
 570 }
 571
 572 /*! \file */