lib/libc/resolv/res_data.c

   1 /*
   2  * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
   3  * Copyright (c) 1995-1999 by Internet Software Consortium.
   4  *
   5  * Permission to use, copy, modify, and distribute this software for any
   6  * purpose with or without fee is hereby granted, provided that the above
   7  * copyright notice and this permission notice appear in all copies.
   8  *
   9  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
  10  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  11  * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
  12  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  13  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  14  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
  15  * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  16  *
  17  * $Id: res_data.c,v 1.5 2007/09/14 05:32:25 marka Exp $
  18  */
  19
  20 #include "port_before.h"
  21
  22 #include <sys/types.h>
  23 #include <sys/param.h>
  24 #include <sys/socket.h>
  25 #include <sys/time.h>
  26
  27 #include <netinet/in.h>
  28 #include <arpa/inet.h>
  29 #include <arpa/nameser.h>
  30
  31 #include <ctype.h>
  32 #include <netdb.h>
  33 #include <resolv.h>
  34 #include <res_update.h>
  35 #include <stdio.h>
  36 #include <stdlib.h>
  37 #include <string.h>
  38 #include <unistd.h>
  39
  40 #include "port_after.h"
  41 #ifndef _LIBC
  42 #undef _res
  43 #endif
  44
  45
  46 const char *_res_opcodes[] = {
  47         "QUERY",
  48         "IQUERY",
  49         "CQUERYM",
  50         "CQUERYU",      /*%< experimental */
  51         "NOTIFY",       /*%< experimental */
  52         "UPDATE",
  53         "6",
  54         "7",
  55         "8",
  56         "9",
  57         "10",
  58         "11",
  59         "12",
  60         "13",
  61         "ZONEINIT",
  62         "ZONEREF",
  63 };
  64
  65 #ifdef BIND_UPDATE
  66 const char *_res_sectioncodes[] = {
  67         "ZONE",
  68         "PREREQUISITES",
  69         "UPDATE",
  70         "ADDITIONAL",
  71 };
  72 #endif
  73
  74 #undef _res
  75 #ifndef __BIND_NOSTATIC
  76 #ifndef _LIBC
  77 struct __res_state _res
  78 # if defined(__BIND_RES_TEXT)
  79         = { RES_TIMEOUT, }      /*%< Motorola, et al. */
  80 # endif
  81         ;
  82 #endif /* !_LIBC */
  83
  84 #if defined(DO_PTHREADS) || defined(__linux)
  85 #define _res (*__res_state())
  86 #endif
  87
  88 /* Proto. */
  89
  90 int  res_ourserver_p(const res_state, const struct sockaddr_in *);
  91
  92 int
  93 res_init(void) {
  94         extern int __res_vinit(res_state, int);
  95
  96         /*
  97          * These three fields used to be statically initialized.  This made
  98          * it hard to use this code in a shared library.  It is necessary,
  99          * now that we're doing dynamic initialization here, that we preserve
 100          * the old semantics: if an application modifies one of these three
 101          * fields of _res before res_init() is called, res_init() will not
 102          * alter them.  Of course, if an application is setting them to
 103          * _zero_ before calling res_init(), hoping to override what used
 104          * to be the static default, we can't detect it and unexpected results
 105          * will follow.  Zero for any of these fields would make no sense,
 106          * so one can safely assume that the applications were already getting
 107          * unexpected results.
 108          *
 109          * _res.options is tricky since some apps were known to diddle the bits
 110          * before res_init() was first called. We can't replicate that semantic
 111          * with dynamic initialization (they may have turned bits off that are
 112          * set in RES_DEFAULT).  Our solution is to declare such applications
 113          * "broken".  They could fool us by setting RES_INIT but none do (yet).
 114          */
 115         if (!_res.retrans)
 116                 _res.retrans = RES_TIMEOUT;
 117         if (!_res.retry)
 118 #ifndef _LIBC
 119                 _res.retry = 4;
 120 #else
 121                 _res.retry = RES_DFLRETRY;
 122 #endif
 123         if (!(_res.options & RES_INIT))
 124                 _res.options = RES_DEFAULT;
 125
 126         /*
 127          * This one used to initialize implicitly to zero, so unless the app
 128          * has set it to something in particular, we can randomize it now.
 129          */
 130         if (!_res.id)
 131                 _res.id = res_randomid();
 132
 133         return (__res_vinit(&_res, 1));
 134 }
 135
 136 void
 137 p_query(const u_char *msg) {
 138         fp_query(msg, stdout);
 139 }
 140
 141 void
 142 fp_query(const u_char *msg, FILE *file) {
 143         fp_nquery(msg, PACKETSZ, file);
 144 }
 145
 146 void
 147 fp_nquery(const u_char *msg, int len, FILE *file) {
 148         if ((_res.options & RES_INIT) == 0U && res_init() == -1)
 149                 return;
 150
 151         res_pquery(&_res, msg, len, file);
 152 }
 153
 154 int
 155 res_mkquery(int op,                     /*!< opcode of query  */
 156             const char *dname,          /*!< domain name  */
 157             int class, int type,        /*!< class and type of query  */
 158             const u_char *data,         /*!< resource record data  */
 159             int datalen,                /*!< length of data  */
 160             const u_char *newrr_in,     /*!< new rr for modify or append  */
 161             u_char *buf,                /*!< buffer to put query  */
 162             int buflen)                 /*!< size of buffer  */
 163 {
 164         if ((_res.options & RES_INIT) == 0U && res_init() == -1) {
 165                 RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
 166                 return (-1);
 167         }
 168         return (res_nmkquery(&_res, op, dname, class, type,
 169                              data, datalen,
 170                              newrr_in, buf, buflen));
 171 }
 172
 173 int
 174 res_mkupdate(ns_updrec *rrecp_in, u_char *buf, int buflen) {
 175         if ((_res.options & RES_INIT) == 0U && res_init() == -1) {
 176                 RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
 177                 return (-1);
 178         }
 179
 180         return (res_nmkupdate(&_res, rrecp_in, buf, buflen));
 181 }
 182
 183 int
 184 res_query(const char *name,     /*!< domain name  */
 185           int class, int type,  /*!< class and type of query  */
 186           u_char *answer,       /*!< buffer to put answer  */
 187           int anslen)           /*!< size of answer buffer  */
 188 {
 189         if ((_res.options & RES_INIT) == 0U && res_init() == -1) {
 190                 RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
 191                 return (-1);
 192         }
 193         return (res_nquery(&_res, name, class, type, answer, anslen));
 194 }
 195
 196 #ifndef _LIBC
 197 void
 198 res_send_setqhook(res_send_qhook hook) {
 199         _res.qhook = hook;
 200 }
 201
 202 void
 203 res_send_setrhook(res_send_rhook hook) {
 204         _res.rhook = hook;
 205 }
 206 #endif
 207
 208 int
 209 res_isourserver(const struct sockaddr_in *inp) {
 210         return (res_ourserver_p(&_res, inp));
 211 }
 212
 213 int
 214 res_send(const u_char *buf, int buflen, u_char *ans, int anssiz) {
 215         if ((_res.options & RES_INIT) == 0U && res_init() == -1) {
 216                 /* errno should have been set by res_init() in this case. */
 217                 return (-1);
 218         }
 219
 220         return (res_nsend(&_res, buf, buflen, ans, anssiz));
 221 }
 222
 223 #ifndef _LIBC
 224 int
 225 res_sendsigned(const u_char *buf, int buflen, ns_tsig_key *key,
 226                u_char *ans, int anssiz)
 227 {
 228         if ((_res.options & RES_INIT) == 0U && res_init() == -1) {
 229                 /* errno should have been set by res_init() in this case. */
 230                 return (-1);
 231         }
 232
 233         return (res_nsendsigned(&_res, buf, buflen, key, ans, anssiz));
 234 }
 235 #endif
 236
 237 void
 238 res_close(void) {
 239         res_nclose(&_res);
 240 }
 241
 242 int
 243 res_update(ns_updrec *rrecp_in) {
 244         if ((_res.options & RES_INIT) == 0U && res_init() == -1) {
 245                 RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
 246                 return (-1);
 247         }
 248
 249         return (res_nupdate(&_res, rrecp_in, NULL));
 250 }
 251
 252 int
 253 res_search(const char *name,    /*!< domain name  */
 254            int class, int type, /*!< class and type of query  */
 255            u_char *answer,      /*!< buffer to put answer  */
 256            int anslen)          /*!< size of answer  */
 257 {
 258         if ((_res.options & RES_INIT) == 0U && res_init() == -1) {
 259                 RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
 260                 return (-1);
 261         }
 262
 263         return (res_nsearch(&_res, name, class, type, answer, anslen));
 264 }
 265
 266 int
 267 res_querydomain(const char *name,
 268                 const char *domain,
 269                 int class, int type,    /*!< class and type of query  */
 270                 u_char *answer,         /*!< buffer to put answer  */
 271                 int anslen)             /*!< size of answer  */
 272 {
 273         if ((_res.options & RES_INIT) == 0U && res_init() == -1) {
 274                 RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
 275                 return (-1);
 276         }
 277
 278         return (res_nquerydomain(&_res, name, domain,
 279                                  class, type,
 280                                  answer, anslen));
 281 }
 282
 283 #ifdef _LIBC
 284 int
 285 res_opt(int n0, u_char *buf, int buflen, int anslen)
 286 {
 287        return (res_nopt(&_res, n0, buf, buflen, anslen));
 288 }
 289 #endif
 290
 291 const char *
 292 hostalias(const char *name) {
 293         static char abuf[MAXDNAME];
 294
 295         return (res_hostalias(&_res, name, abuf, sizeof abuf));
 296 }
 297
 298 #ifdef ultrix
 299 int
 300 local_hostname_length(const char *hostname) {
 301         int len_host, len_domain;
 302
 303         if (!*_res.defdname)
 304                 res_init();
 305         len_host = strlen(hostname);
 306         len_domain = strlen(_res.defdname);
 307         if (len_host > len_domain &&
 308             !strcasecmp(hostname + len_host - len_domain, _res.defdname) &&
 309             hostname[len_host - len_domain - 1] == '.')
 310                 return (len_host - len_domain - 1);
 311         return (0);
 312 }
 313 #endif /*ultrix*/
 314
 315 #ifdef _LIBC
 316 /*
 317  * Weak aliases for applications that use certain private entry points,
 318  * and fail to include <resolv.h>.
 319  */
 320 #undef res_init
 321 __weak_reference(__res_init, res_init);
 322 #undef p_query
 323 __weak_reference(__p_query, p_query);
 324 #undef res_mkquery
 325 __weak_reference(__res_mkquery, res_mkquery);
 326 #undef res_query
 327 __weak_reference(__res_query, res_query);
 328 #undef res_send
 329 __weak_reference(__res_send, res_send);
 330 #undef res_close
 331 __weak_reference(__res_close, _res_close);
 332 #undef res_search
 333 __weak_reference(__res_search, res_search);
 334 #undef res_querydomain
 335 __weak_reference(__res_querydomain, res_querydomain);
 336 #endif
 337
 338 #endif
 339 /*! \file */