src/kits/network/netresolv/resolv/res_data.c

   1 /*      $NetBSD: res_data.c,v 1.14 2009/10/24 05:35:37 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 1.14 2009/10/24 05:35:37 christos Exp $");
  26 #endif
  27 #endif /* LIBC_SCCS and not lint */
  28
  29 #include "port_before.h"
  30
  31 #include <sys/types.h>
  32 #include <sys/param.h>
  33 #include <sys/socket.h>
  34 #include <sys/time.h>
  35
  36 #include <netinet/in.h>
  37 #include <arpa/inet.h>
  38 #include <arpa/nameser.h>
  39
  40 #include <ctype.h>
  41 #include <netdb.h>
  42 #include <resolv.h>
  43 #include <res_update.h>
  44 #include <stdio.h>
  45 #include <stdlib.h>
  46 #include <string.h>
  47 #include <unistd.h>
  48
  49 #include "port_after.h"
  50
  51 #include "res_private.h"
  52
  53 #ifdef __weak_alias
  54 __weak_alias(res_init,_res_init)
  55 __weak_alias(res_mkquery,_res_mkquery)
  56 __weak_alias(res_query,_res_query)
  57 __weak_alias(res_search,_res_search)
  58 __weak_alias(res_send,__res_send)
  59 __weak_alias(res_close,__res_close)
  60 /* XXX: these leaked in the old bind8 libc */
  61 __weak_alias(res_querydomain,__res_querydomain)
  62 __weak_alias(res_send_setqhook,__res_send_setqhook)
  63 __weak_alias(res_send_setrhook,__res_send_setrhook)
  64 #if 0
  65 __weak_alias(p_query,__p_query)
  66 __weak_alias(fp_query,__fp_query)
  67 __weak_alias(fp_nquery,__fp_nquery)
  68 __weak_alias(res_isourserver,__res_isourserver)
  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 #ifdef COMPAT__RES
 112         /*
 113          * Compatibility with program that were accessing _res directly
 114          * to set options. We keep another struct res that is the same
 115          * size as the original res structure, and then copy fields to
 116          * it so that we achieve the same initialization
 117          */
 118         extern void *__res_get_old_state(void);
 119         extern void __res_put_old_state(void *);
 120         res_state ores = __res_get_old_state();
 121
 122         if (ores->options != 0)
 123                 _nres.options = ores->options;
 124         if (ores->retrans != 0)
 125                 _nres.retrans = ores->retrans;
 126         if (ores->retry != 0)
 127                 _nres.retry = ores->retry;
 128 #endif
 129
 130         /*
 131          * These three fields used to be statically initialized.  This made
 132          * it hard to use this code in a shared library.  It is necessary,
 133          * now that we're doing dynamic initialization here, that we preserve
 134          * the old semantics: if an application modifies one of these three
 135          * fields of _res before res_init() is called, res_init() will not
 136          * alter them.  Of course, if an application is setting them to
 137          * _zero_ before calling res_init(), hoping to override what used
 138          * to be the static default, we can't detect it and unexpected results
 139          * will follow.  Zero for any of these fields would make no sense,
 140          * so one can safely assume that the applications were already getting
 141          * unexpected results.
 142          *
 143          * _nres.options is tricky since some apps were known to diddle the bits
 144          * before res_init() was first called. We can't replicate that semantic
 145          * with dynamic initialization (they may have turned bits off that are
 146          * set in RES_DEFAULT).  Our solution is to declare such applications
 147          * "broken".  They could fool us by setting RES_INIT but none do (yet).
 148          */
 149         if (!_nres.retrans)
 150                 _nres.retrans = RES_TIMEOUT;
 151         if (!_nres.retry)
 152                 _nres.retry = 4;
 153         if (!(_nres.options & RES_INIT))
 154                 _nres.options = RES_DEFAULT;
 155
 156         /*
 157          * This one used to initialize implicitly to zero, so unless the app
 158          * has set it to something in particular, we can randomize it now.
 159          */
 160         if (!_nres.id)
 161                 _nres.id = res_nrandomid(&_nres);
 162
 163         rv = __res_vinit(&_nres, 1);
 164 #ifdef COMPAT__RES
 165         __res_put_old_state(&_nres);
 166 #endif
 167         return rv;
 168 }
 169
 170 void
 171 p_query(const u_char *msg) {
 172         fp_query(msg, stdout);
 173 }
 174
 175 void
 176 fp_query(const u_char *msg, FILE *file) {
 177         fp_nquery(msg, PACKETSZ, file);
 178 }
 179
 180 void
 181 fp_nquery(const u_char *msg, int len, FILE *file) {
 182         if ((_nres.options & RES_INIT) == 0U && res_init() == -1)
 183                 return;
 184
 185         res_pquery(&_nres, msg, len, file);
 186 }
 187
 188 int
 189 res_mkquery(int op,                     /*!< opcode of query  */
 190             const char *dname,          /*!< domain name  */
 191             int class, int type,        /*!< class and type of query  */
 192             const u_char *data,         /*!< resource record data  */
 193             int datalen,                /*!< length of data  */
 194             const u_char *newrr_in,     /*!< new rr for modify or append  */
 195             u_char *buf,                /*!< buffer to put query  */
 196             int buflen)                 /*!< size of buffer  */
 197 {
 198         if ((_nres.options & RES_INIT) == 0U && res_init() == -1) {
 199                 RES_SET_H_ERRNO(&_nres, NETDB_INTERNAL);
 200                 return (-1);
 201         }
 202         return (res_nmkquery(&_nres, op, dname, class, type,
 203                              data, datalen,
 204                              newrr_in, buf, buflen));
 205 }
 206
 207 #ifdef _LIBRESOLV
 208 int
 209 res_mkupdate(ns_updrec *rrecp_in, u_char *buf, int buflen) {
 210         if ((_nres.options & RES_INIT) == 0U && res_init() == -1) {
 211                 RES_SET_H_ERRNO(&_nres, NETDB_INTERNAL);
 212                 return (-1);
 213         }
 214
 215         return (res_nmkupdate(&_nres, rrecp_in, buf, buflen));
 216 }
 217 #endif
 218
 219 int
 220 res_query(const char *name,     /*!< domain name  */
 221           int class, int type,  /*!< class and type of query  */
 222           u_char *answer,       /*!< buffer to put answer  */
 223           int anslen)           /*!< size of answer buffer  */
 224 {
 225         if ((_nres.options & RES_INIT) == 0U && res_init() == -1) {
 226                 RES_SET_H_ERRNO(&_nres, NETDB_INTERNAL);
 227                 return (-1);
 228         }
 229         return (res_nquery(&_nres, name, class, type, answer, anslen));
 230 }
 231
 232 void
 233 res_send_setqhook(res_send_qhook hook) {
 234         _nres.qhook = hook;
 235 }
 236
 237 void
 238 res_send_setrhook(res_send_rhook hook) {
 239         _nres.rhook = hook;
 240 }
 241
 242 int
 243 res_isourserver(const struct sockaddr_in *inp) {
 244         return (res_ourserver_p(&_nres, (const struct sockaddr *)(const void *)inp));
 245 }
 246
 247 int
 248 res_send(const u_char *buf, int buflen, u_char *ans, int anssiz) {
 249         if ((_nres.options & RES_INIT) == 0U && res_init() == -1) {
 250                 /* errno should have been set by res_init() in this case. */
 251                 return (-1);
 252         }
 253
 254         return (res_nsend(&_nres, buf, buflen, ans, anssiz));
 255 }
 256
 257 #ifdef _LIBRESOLV
 258 int
 259 res_sendsigned(const u_char *buf, int buflen, ns_tsig_key *key,
 260                u_char *ans, int anssiz)
 261 {
 262         if ((_nres.options & RES_INIT) == 0U && res_init() == -1) {
 263                 /* errno should have been set by res_init() in this case. */
 264                 return (-1);
 265         }
 266
 267         return (res_nsendsigned(&_nres, buf, buflen, key, ans, anssiz));
 268 }
 269 #endif
 270
 271 void
 272 res_close(void) {
 273         res_nclose(&_nres);
 274 }
 275
 276 #ifdef _LIBRESOLV
 277 int
 278 res_update(ns_updrec *rrecp_in) {
 279         if ((_nres.options & RES_INIT) == 0U && res_init() == -1) {
 280                 RES_SET_H_ERRNO(&_nres, NETDB_INTERNAL);
 281                 return (-1);
 282         }
 283
 284         return (res_nupdate(&_nres, rrecp_in, NULL));
 285 }
 286 #endif
 287
 288 int
 289 res_search(const char *name,    /*!< domain name  */
 290            int class, int type, /*!< class and type of query  */
 291            u_char *answer,      /*!< buffer to put answer  */
 292            int anslen)          /*!< size of answer  */
 293 {
 294         if ((_nres.options & RES_INIT) == 0U && res_init() == -1) {
 295                 RES_SET_H_ERRNO(&_nres, NETDB_INTERNAL);
 296                 return (-1);
 297         }
 298
 299         return (res_nsearch(&_nres, name, class, type, answer, anslen));
 300 }
 301
 302 int
 303 res_querydomain(const char *name,
 304                 const char *domain,
 305                 int class, int type,    /*!< class and type of query  */
 306                 u_char *answer,         /*!< buffer to put answer  */
 307                 int anslen)             /*!< size of answer  */
 308 {
 309         if ((_nres.options & RES_INIT) == 0U && res_init() == -1) {
 310                 RES_SET_H_ERRNO(&_nres, NETDB_INTERNAL);
 311                 return (-1);
 312         }
 313
 314         return (res_nquerydomain(&_nres, name, domain,
 315                                  class, type,
 316                                  answer, anslen));
 317 }
 318
 319 u_int
 320 res_randomid(void) {
 321         if ((_nres.options & RES_INIT) == 0U && res_init() == -1) {
 322                 RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
 323                 return (u_int)-1;
 324         }
 325
 326         return (res_nrandomid(&_nres));
 327 }
 328
 329 const char *
 330 hostalias(const char *name) {
 331         static char abuf[MAXDNAME];
 332
 333         return (res_hostalias(&_nres, name, abuf, sizeof abuf));
 334 }
 335
 336 #ifdef ultrix
 337 int
 338 local_hostname_length(const char *hostname) {
 339         int len_host, len_domain;
 340
 341         if (!*_nres.defdname)
 342                 res_init();
 343         len_host = strlen(hostname);
 344         len_domain = strlen(_nres.defdname);
 345         if (len_host > len_domain &&
 346             !strcasecmp(hostname + len_host - len_domain, _nres.defdname) &&
 347             hostname[len_host - len_domain - 1] == '.')
 348                 return (len_host - len_domain - 1);
 349         return (0);
 350 }
 351 #endif /*ultrix*/
 352
 353 #endif
 354
 355 /*! \file */