lib/libc/resolv/res_data.c

   1 /*      $NetBSD: res_data.c,v 1.12 2009/04/12 17:07:17 christos Exp $   */
   2
   3 /*
   4  * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
   5  * Copyright (c) 1995-1999 by Internet Software Consortium.
   6  *
   7  * Permission to use, copy, modify, and distribute this software for any
   8  * purpose with or without fee is hereby granted, provided that the above
   9  * copyright notice and this permission notice appear in all copies.
  10  *
  11  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
  12  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  13  * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
  14  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  15  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  16  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
  17  * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  18  */
  19
  20 #include <sys/cdefs.h>
  21 #if defined(LIBC_SCCS) && !defined(lint)
  22 #ifdef notdef
  23 static const char rcsid[] = "Id: res_data.c,v 1.7 2008/12/11 09:59:00 marka Exp";
  24 #else
  25 __RCSID("$NetBSD: res_data.c,v 1.12 2009/04/12 17:07:17 christos Exp $");
  26 #endif
  27 #endif /* LIBC_SCCS and not lint */
  28
  29 #include "port_before.h"
  30
  31 #include "namespace.h"
  32 #include <sys/types.h>
  33 #include <sys/param.h>
  34 #include <sys/socket.h>
  35 #include <sys/time.h>
  36
  37 #include <netinet/in.h>
  38 #include <arpa/inet.h>
  39 #include <arpa/nameser.h>
  40
  41 #include <ctype.h>
  42 #include <netdb.h>
  43 #include <resolv.h>
  44 #include <res_update.h>
  45 #include <stdio.h>
  46 #include <stdlib.h>
  47 #include <string.h>
  48 #include <unistd.h>
  49
  50 #include "port_after.h"
  51
  52 #ifdef __weak_alias
  53 __weak_alias(res_init,_res_init)
  54 __weak_alias(res_mkquery,_res_mkquery)
  55 __weak_alias(res_query,_res_query)
  56 __weak_alias(res_search,_res_search)
  57 __weak_alias(res_send,__res_send)
  58 __weak_alias(res_close,__res_close)
  59 /* XXX: these leaked in the old bind8 libc */
  60 __weak_alias(res_querydomain,__res_querydomain)
  61 __weak_alias(res_send_setqhook,__res_send_setqhook)
  62 __weak_alias(res_send_setrhook,__res_send_setrhook)
  63 #if 0
  64 __weak_alias(p_query,__p_query)
  65 __weak_alias(fp_query,__fp_query)
  66 __weak_alias(fp_nquery,__fp_nquery)
  67 __weak_alias(res_isourserver,__res_isourserver)
  68 __weak_alias(res_opt,_res_opt)
  69 __weak_alias(hostalias,__hostalias)
  70 #endif
  71 #endif
  72
  73 const char *_res_opcodes[] = {
  74         "QUERY",
  75         "IQUERY",
  76         "CQUERYM",
  77         "CQUERYU",      /*%< experimental */
  78         "NOTIFY",       /*%< experimental */
  79         "UPDATE",
  80         "6",
  81         "7",
  82         "8",
  83         "9",
  84         "10",
  85         "11",
  86         "12",
  87         "13",
  88         "ZONEINIT",
  89         "ZONEREF",
  90 };
  91
  92 #ifdef BIND_UPDATE
  93 const char *_res_sectioncodes[] = {
  94         "ZONE",
  95         "PREREQUISITES",
  96         "UPDATE",
  97         "ADDITIONAL",
  98 };
  99 #endif
 100
 101 #ifndef __BIND_NOSTATIC
 102 extern struct __res_state _nres;
 103
 104 /* Proto. */
 105
 106 int  res_ourserver_p(const res_state, const struct sockaddr *);
 107
 108 int
 109 res_init(void) {
 110         int rv;
 111         extern int __res_vinit(res_state, int);
 112 #ifdef COMPAT__RES
 113         /*
 114          * Compatibility with program that were accessing _res directly
 115          * to set options. We keep another struct res that is the same
 116          * size as the original res structure, and then copy fields to
 117          * it so that we achieve the same initialization
 118          */
 119         extern void *__res_get_old_state(void);
 120         extern void __res_put_old_state(void *);
 121         res_state ores = __res_get_old_state();
 122
 123         if (ores->options != 0)
 124                 _nres.options = ores->options;
 125         if (ores->retrans != 0)
 126                 _nres.retrans = ores->retrans;
 127         if (ores->retry != 0)
 128                 _nres.retry = ores->retry;
 129 #endif
 130
 131         /*
 132          * These three fields used to be statically initialized.  This made
 133          * it hard to use this code in a shared library.  It is necessary,
 134          * now that we're doing dynamic initialization here, that we preserve
 135          * the old semantics: if an application modifies one of these three
 136          * fields of _res before res_init() is called, res_init() will not
 137          * alter them.  Of course, if an application is setting them to
 138          * _zero_ before calling res_init(), hoping to override what used
 139          * to be the static default, we can't detect it and unexpected results
 140          * will follow.  Zero for any of these fields would make no sense,
 141          * so one can safely assume that the applications were already getting
 142          * unexpected results.
 143          *
 144          * _nres.options is tricky since some apps were known to diddle the bits
 145          * before res_init() was first called. We can't replicate that semantic
 146          * with dynamic initialization (they may have turned bits off that are
 147          * set in RES_DEFAULT).  Our solution is to declare such applications
 148          * "broken".  They could fool us by setting RES_INIT but none do (yet).
 149          */
 150         if (!_nres.retrans)
 151                 _nres.retrans = RES_TIMEOUT;
 152         if (!_nres.retry)
 153                 _nres.retry = 4;
 154         if (!(_nres.options & RES_INIT))
 155                 _nres.options = RES_DEFAULT;
 156
 157         /*
 158          * This one used to initialize implicitly to zero, so unless the app
 159          * has set it to something in particular, we can randomize it now.
 160          */
 161         if (!_nres.id)
 162                 _nres.id = res_nrandomid(&_nres);
 163
 164         rv = __res_vinit(&_nres, 1);
 165 #ifdef COMPAT__RES
 166         __res_put_old_state(&_nres);
 167 #endif
 168         return rv;
 169 }
 170
 171 void
 172 p_query(const u_char *msg) {
 173         fp_query(msg, stdout);
 174 }
 175
 176 void
 177 fp_query(const u_char *msg, FILE *file) {
 178         fp_nquery(msg, PACKETSZ, file);
 179 }
 180
 181 void
 182 fp_nquery(const u_char *msg, int len, FILE *file) {
 183         if ((_nres.options & RES_INIT) == 0U && res_init() == -1)
 184                 return;
 185
 186         res_pquery(&_nres, msg, len, file);
 187 }
 188
 189 int
 190 res_mkquery(int op,                     /*!< opcode of query  */
 191             const char *dname,          /*!< domain name  */
 192             int class, int type,        /*!< class and type of query  */
 193             const u_char *data,         /*!< resource record data  */
 194             int datalen,                /*!< length of data  */
 195             const u_char *newrr_in,     /*!< new rr for modify or append  */
 196             u_char *buf,                /*!< buffer to put query  */
 197             int buflen)                 /*!< size of buffer  */
 198 {
 199         if ((_nres.options & RES_INIT) == 0U && res_init() == -1) {
 200                 RES_SET_H_ERRNO(&_nres, NETDB_INTERNAL);
 201                 return (-1);
 202         }
 203         return (res_nmkquery(&_nres, op, dname, class, type,
 204                              data, datalen,
 205                              newrr_in, buf, buflen));
 206 }
 207
 208 #ifdef _LIBRESOLV
 209 int
 210 res_mkupdate(ns_updrec *rrecp_in, u_char *buf, int buflen) {
 211         if ((_nres.options & RES_INIT) == 0U && res_init() == -1) {
 212                 RES_SET_H_ERRNO(&_nres, NETDB_INTERNAL);
 213                 return (-1);
 214         }
 215
 216         return (res_nmkupdate(&_nres, rrecp_in, buf, buflen));
 217 }
 218 #endif
 219
 220 int
 221 res_query(const char *name,     /*!< domain name  */
 222           int class, int type,  /*!< class and type of query  */
 223           u_char *answer,       /*!< buffer to put answer  */
 224           int anslen)           /*!< size of answer buffer  */
 225 {
 226         if ((_nres.options & RES_INIT) == 0U && res_init() == -1) {
 227                 RES_SET_H_ERRNO(&_nres, NETDB_INTERNAL);
 228                 return (-1);
 229         }
 230         return (res_nquery(&_nres, name, class, type, answer, anslen));
 231 }
 232
 233 void
 234 res_send_setqhook(res_send_qhook hook) {
 235         _nres.qhook = hook;
 236 }
 237
 238 void
 239 res_send_setrhook(res_send_rhook hook) {
 240         _nres.rhook = hook;
 241 }
 242
 243 int
 244 res_isourserver(const struct sockaddr_in *inp) {
 245         return (res_ourserver_p(&_nres, (const struct sockaddr *)(const void *)inp));
 246 }
 247
 248 int
 249 res_send(const u_char *buf, int buflen, u_char *ans, int anssiz) {
 250         if ((_nres.options & RES_INIT) == 0U && res_init() == -1) {
 251                 /* errno should have been set by res_init() in this case. */
 252                 return (-1);
 253         }
 254
 255         return (res_nsend(&_nres, buf, buflen, ans, anssiz));
 256 }
 257
 258 #ifdef _LIBRESOLV
 259 int
 260 res_sendsigned(const u_char *buf, int buflen, ns_tsig_key *key,
 261                u_char *ans, int anssiz)
 262 {
 263         if ((_nres.options & RES_INIT) == 0U && res_init() == -1) {
 264                 /* errno should have been set by res_init() in this case. */
 265                 return (-1);
 266         }
 267
 268         return (res_nsendsigned(&_nres, buf, buflen, key, ans, anssiz));
 269 }
 270 #endif
 271
 272 void
 273 res_close(void) {
 274         res_nclose(&_nres);
 275 }
 276
 277 #ifdef _LIBRESOLV
 278 int
 279 res_update(ns_updrec *rrecp_in) {
 280         if ((_nres.options & RES_INIT) == 0U && res_init() == -1) {
 281                 RES_SET_H_ERRNO(&_nres, NETDB_INTERNAL);
 282                 return (-1);
 283         }
 284
 285         return (res_nupdate(&_nres, rrecp_in, NULL));
 286 }
 287 #endif
 288
 289 int
 290 res_search(const char *name,    /*!< domain name  */
 291            int class, int type, /*!< class and type of query  */
 292            u_char *answer,      /*!< buffer to put answer  */
 293            int anslen)          /*!< size of answer  */
 294 {
 295         if ((_nres.options & RES_INIT) == 0U && res_init() == -1) {
 296                 RES_SET_H_ERRNO(&_nres, NETDB_INTERNAL);
 297                 return (-1);
 298         }
 299
 300         return (res_nsearch(&_nres, name, class, type, answer, anslen));
 301 }
 302
 303 int
 304 res_querydomain(const char *name,
 305                 const char *domain,
 306                 int class, int type,    /*!< class and type of query  */
 307                 u_char *answer,         /*!< buffer to put answer  */
 308                 int anslen)             /*!< size of answer  */
 309 {
 310         if ((_nres.options & RES_INIT) == 0U && res_init() == -1) {
 311                 RES_SET_H_ERRNO(&_nres, NETDB_INTERNAL);
 312                 return (-1);
 313         }
 314
 315         return (res_nquerydomain(&_nres, name, domain,
 316                                  class, type,
 317                                  answer, anslen));
 318 }
 319
 320 int
 321 res_opt(int a, u_char *b, int c, int d)
 322 {
 323         return res_nopt(&_nres, a, b, c, d);
 324 }
 325
 326 u_int
 327 res_randomid(void) {
 328         if ((_nres.options & RES_INIT) == 0U && res_init() == -1) {
 329                 RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
 330                 return (u_int)-1;
 331         }
 332
 333         return (res_nrandomid(&_nres));
 334 }
 335
 336 const char *
 337 hostalias(const char *name) {
 338         static char abuf[MAXDNAME];
 339
 340         return (res_hostalias(&_nres, name, abuf, sizeof abuf));
 341 }
 342
 343 #ifdef ultrix
 344 int
 345 local_hostname_length(const char *hostname) {
 346         int len_host, len_domain;
 347
 348         if (!*_nres.defdname)
 349                 res_init();
 350         len_host = strlen(hostname);
 351         len_domain = strlen(_nres.defdname);
 352         if (len_host > len_domain &&
 353             !strcasecmp(hostname + len_host - len_domain, _nres.defdname) &&
 354             hostname[len_host - len_domain - 1] == '.')
 355                 return (len_host - len_domain - 1);
 356         return (0);
 357 }
 358 #endif /*ultrix*/
 359
 360 #endif
 361
 362 /*! \file */