lib/libc/resolv/res_data.c

   1 /*      $NetBSD: res_data.c,v 1.13 2009/04/12 19:43:37 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 1.13 2009/04/12 19:43:37 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 #include "res_private.h"
  53
  54 #ifdef __weak_alias
  55 __weak_alias(res_init,_res_init)
  56 __weak_alias(res_mkquery,_res_mkquery)
  57 __weak_alias(res_query,_res_query)
  58 __weak_alias(res_search,_res_search)
  59 __weak_alias(res_send,__res_send)
  60 __weak_alias(res_close,__res_close)
  61 /* XXX: these leaked in the old bind8 libc */
  62 __weak_alias(res_querydomain,__res_querydomain)
  63 __weak_alias(res_send_setqhook,__res_send_setqhook)
  64 __weak_alias(res_send_setrhook,__res_send_setrhook)
  65 #if 0
  66 __weak_alias(p_query,__p_query)
  67 __weak_alias(fp_query,__fp_query)
  68 __weak_alias(fp_nquery,__fp_nquery)
  69 __weak_alias(res_isourserver,__res_isourserver)
  70 __weak_alias(res_opt,_res_opt)
  71 __weak_alias(hostalias,__hostalias)
  72 #endif
  73 #endif
  74
  75 const char *_res_opcodes[] = {
  76         "QUERY",
  77         "IQUERY",
  78         "CQUERYM",
  79         "CQUERYU",      /*%< experimental */
  80         "NOTIFY",       /*%< experimental */
  81         "UPDATE",
  82         "6",
  83         "7",
  84         "8",
  85         "9",
  86         "10",
  87         "11",
  88         "12",
  89         "13",
  90         "ZONEINIT",
  91         "ZONEREF",
  92 };
  93
  94 #ifdef BIND_UPDATE
  95 const char *_res_sectioncodes[] = {
  96         "ZONE",
  97         "PREREQUISITES",
  98         "UPDATE",
  99         "ADDITIONAL",
 100 };
 101 #endif
 102
 103 #ifndef __BIND_NOSTATIC
 104 extern struct __res_state _nres;
 105
 106 /* Proto. */
 107
 108 int  res_ourserver_p(const res_state, const struct sockaddr *);
 109
 110 int
 111 res_init(void) {
 112         int rv;
 113 #ifdef COMPAT__RES
 114         /*
 115          * Compatibility with program that were accessing _res directly
 116          * to set options. We keep another struct res that is the same
 117          * size as the original res structure, and then copy fields to
 118          * it so that we achieve the same initialization
 119          */
 120         extern void *__res_get_old_state(void);
 121         extern void __res_put_old_state(void *);
 122         res_state ores = __res_get_old_state();
 123
 124         if (ores->options != 0)
 125                 _nres.options = ores->options;
 126         if (ores->retrans != 0)
 127                 _nres.retrans = ores->retrans;
 128         if (ores->retry != 0)
 129                 _nres.retry = ores->retry;
 130 #endif
 131
 132         /*
 133          * These three fields used to be statically initialized.  This made
 134          * it hard to use this code in a shared library.  It is necessary,
 135          * now that we're doing dynamic initialization here, that we preserve
 136          * the old semantics: if an application modifies one of these three
 137          * fields of _res before res_init() is called, res_init() will not
 138          * alter them.  Of course, if an application is setting them to
 139          * _zero_ before calling res_init(), hoping to override what used
 140          * to be the static default, we can't detect it and unexpected results
 141          * will follow.  Zero for any of these fields would make no sense,
 142          * so one can safely assume that the applications were already getting
 143          * unexpected results.
 144          *
 145          * _nres.options is tricky since some apps were known to diddle the bits
 146          * before res_init() was first called. We can't replicate that semantic
 147          * with dynamic initialization (they may have turned bits off that are
 148          * set in RES_DEFAULT).  Our solution is to declare such applications
 149          * "broken".  They could fool us by setting RES_INIT but none do (yet).
 150          */
 151         if (!_nres.retrans)
 152                 _nres.retrans = RES_TIMEOUT;
 153         if (!_nres.retry)
 154                 _nres.retry = 4;
 155         if (!(_nres.options & RES_INIT))
 156                 _nres.options = RES_DEFAULT;
 157
 158         /*
 159          * This one used to initialize implicitly to zero, so unless the app
 160          * has set it to something in particular, we can randomize it now.
 161          */
 162         if (!_nres.id)
 163                 _nres.id = res_nrandomid(&_nres);
 164
 165         rv = __res_vinit(&_nres, 1);
 166 #ifdef COMPAT__RES
 167         __res_put_old_state(&_nres);
 168 #endif
 169         return rv;
 170 }
 171
 172 void
 173 p_query(const u_char *msg) {
 174         fp_query(msg, stdout);
 175 }
 176
 177 void
 178 fp_query(const u_char *msg, FILE *file) {
 179         fp_nquery(msg, PACKETSZ, file);
 180 }
 181
 182 void
 183 fp_nquery(const u_char *msg, int len, FILE *file) {
 184         if ((_nres.options & RES_INIT) == 0U && res_init() == -1)
 185                 return;
 186
 187         res_pquery(&_nres, msg, len, file);
 188 }
 189
 190 int
 191 res_mkquery(int op,                     /*!< opcode of query  */
 192             const char *dname,          /*!< domain name  */
 193             int class, int type,        /*!< class and type of query  */
 194             const u_char *data,         /*!< resource record data  */
 195             int datalen,                /*!< length of data  */
 196             const u_char *newrr_in,     /*!< new rr for modify or append  */
 197             u_char *buf,                /*!< buffer to put query  */
 198             int buflen)                 /*!< size of buffer  */
 199 {
 200         if ((_nres.options & RES_INIT) == 0U && res_init() == -1) {
 201                 RES_SET_H_ERRNO(&_nres, NETDB_INTERNAL);
 202                 return (-1);
 203         }
 204         return (res_nmkquery(&_nres, op, dname, class, type,
 205                              data, datalen,
 206                              newrr_in, buf, buflen));
 207 }
 208
 209 #ifdef _LIBRESOLV
 210 int
 211 res_mkupdate(ns_updrec *rrecp_in, u_char *buf, int buflen) {
 212         if ((_nres.options & RES_INIT) == 0U && res_init() == -1) {
 213                 RES_SET_H_ERRNO(&_nres, NETDB_INTERNAL);
 214                 return (-1);
 215         }
 216
 217         return (res_nmkupdate(&_nres, rrecp_in, buf, buflen));
 218 }
 219 #endif
 220
 221 int
 222 res_query(const char *name,     /*!< domain name  */
 223           int class, int type,  /*!< class and type of query  */
 224           u_char *answer,       /*!< buffer to put answer  */
 225           int anslen)           /*!< size of answer buffer  */
 226 {
 227         if ((_nres.options & RES_INIT) == 0U && res_init() == -1) {
 228                 RES_SET_H_ERRNO(&_nres, NETDB_INTERNAL);
 229                 return (-1);
 230         }
 231         return (res_nquery(&_nres, name, class, type, answer, anslen));
 232 }
 233
 234 void
 235 res_send_setqhook(res_send_qhook hook) {
 236         _nres.qhook = hook;
 237 }
 238
 239 void
 240 res_send_setrhook(res_send_rhook hook) {
 241         _nres.rhook = hook;
 242 }
 243
 244 int
 245 res_isourserver(const struct sockaddr_in *inp) {
 246         return (res_ourserver_p(&_nres, (const struct sockaddr *)(const void *)inp));
 247 }
 248
 249 int
 250 res_send(const u_char *buf, int buflen, u_char *ans, int anssiz) {
 251         if ((_nres.options & RES_INIT) == 0U && res_init() == -1) {
 252                 /* errno should have been set by res_init() in this case. */
 253                 return (-1);
 254         }
 255
 256         return (res_nsend(&_nres, buf, buflen, ans, anssiz));
 257 }
 258
 259 #ifdef _LIBRESOLV
 260 int
 261 res_sendsigned(const u_char *buf, int buflen, ns_tsig_key *key,
 262                u_char *ans, int anssiz)
 263 {
 264         if ((_nres.options & RES_INIT) == 0U && res_init() == -1) {
 265                 /* errno should have been set by res_init() in this case. */
 266                 return (-1);
 267         }
 268
 269         return (res_nsendsigned(&_nres, buf, buflen, key, ans, anssiz));
 270 }
 271 #endif
 272
 273 void
 274 res_close(void) {
 275         res_nclose(&_nres);
 276 }
 277
 278 #ifdef _LIBRESOLV
 279 int
 280 res_update(ns_updrec *rrecp_in) {
 281         if ((_nres.options & RES_INIT) == 0U && res_init() == -1) {
 282                 RES_SET_H_ERRNO(&_nres, NETDB_INTERNAL);
 283                 return (-1);
 284         }
 285
 286         return (res_nupdate(&_nres, rrecp_in, NULL));
 287 }
 288 #endif
 289
 290 int
 291 res_search(const char *name,    /*!< domain name  */
 292            int class, int type, /*!< class and type of query  */
 293            u_char *answer,      /*!< buffer to put answer  */
 294            int anslen)          /*!< size of answer  */
 295 {
 296         if ((_nres.options & RES_INIT) == 0U && res_init() == -1) {
 297                 RES_SET_H_ERRNO(&_nres, NETDB_INTERNAL);
 298                 return (-1);
 299         }
 300
 301         return (res_nsearch(&_nres, name, class, type, answer, anslen));
 302 }
 303
 304 int
 305 res_querydomain(const char *name,
 306                 const char *domain,
 307                 int class, int type,    /*!< class and type of query  */
 308                 u_char *answer,         /*!< buffer to put answer  */
 309                 int anslen)             /*!< size of answer  */
 310 {
 311         if ((_nres.options & RES_INIT) == 0U && res_init() == -1) {
 312                 RES_SET_H_ERRNO(&_nres, NETDB_INTERNAL);
 313                 return (-1);
 314         }
 315
 316         return (res_nquerydomain(&_nres, name, domain,
 317                                  class, type,
 318                                  answer, anslen));
 319 }
 320
 321 int
 322 res_opt(int a, u_char *b, int c, int d)
 323 {
 324         return res_nopt(&_nres, a, b, c, d);
 325 }
 326
 327 u_int
 328 res_randomid(void) {
 329         if ((_nres.options & RES_INIT) == 0U && res_init() == -1) {
 330                 RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
 331                 return (u_int)-1;
 332         }
 333
 334         return (res_nrandomid(&_nres));
 335 }
 336
 337 const char *
 338 hostalias(const char *name) {
 339         static char abuf[MAXDNAME];
 340
 341         return (res_hostalias(&_nres, name, abuf, sizeof abuf));
 342 }
 343
 344 #ifdef ultrix
 345 int
 346 local_hostname_length(const char *hostname) {
 347         int len_host, len_domain;
 348
 349         if (!*_nres.defdname)
 350                 res_init();
 351         len_host = strlen(hostname);
 352         len_domain = strlen(_nres.defdname);
 353         if (len_host > len_domain &&
 354             !strcasecmp(hostname + len_host - len_domain, _nres.defdname) &&
 355             hostname[len_host - len_domain - 1] == '.')
 356                 return (len_host - len_domain - 1);
 357         return (0);
 358 }
 359 #endif /*ultrix*/
 360
 361 #endif
 362
 363 /*! \file */