include/resolv.h

   1 /*
   2  * Copyright (c) 1983, 1987, 1989
   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  * 4. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  */
  29
  30 /*
  31  * Portions Copyright (c) 1996-1999 by Internet Software Consortium.
  32  *
  33  * Permission to use, copy, modify, and distribute this software for any
  34  * purpose with or without fee is hereby granted, provided that the above
  35  * copyright notice and this permission notice appear in all copies.
  36  *
  37  * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
  38  * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
  39  * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
  40  * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
  41  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
  42  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
  43  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
  44  * SOFTWARE.
  45  */
  46
  47 /*
  48  *      @(#)resolv.h    8.1 (Berkeley) 6/2/93
  49  *      $BINDId: resolv.h,v 8.31 2000/03/30 20:16:50 vixie Exp $
  50  */
  51
  52 #ifndef _RESOLV_H_
  53
  54 /* These headers are needed for types used in the `struct res_state'
  55    declaration.  */
  56 #include <sys/types.h>
  57 #include <netinet/in.h>
  58
  59 #ifndef __need_res_state
  60 # define _RESOLV_H_
  61
  62 # include <sys/param.h>
  63 # include <sys/cdefs.h>
  64 # include <stdio.h>
  65 # include <arpa/nameser.h>
  66 #endif
  67
  68 #ifndef __res_state_defined
  69 # define __res_state_defined
  70
  71 typedef enum { res_goahead, res_nextns, res_modified, res_done, res_error }
  72         res_sendhookact;
  73
  74 typedef res_sendhookact (*res_send_qhook) (struct sockaddr_in * const *ns,
  75                                            const u_char **query,
  76                                            int *querylen,
  77                                            u_char *ans,
  78                                            int anssiz,
  79                                            int *resplen);
  80
  81 typedef res_sendhookact (*res_send_rhook) (const struct sockaddr_in *ns,
  82                                            const u_char *query,
  83                                            int querylen,
  84                                            u_char *ans,
  85                                            int anssiz,
  86                                            int *resplen);
  87
  88 /*
  89  * Global defines and variables for resolver stub.
  90  */
  91 # define MAXNS                  3       /* max # name servers we'll track */
  92 # define MAXDFLSRCH             3       /* # default domain levels to try */
  93 # define MAXDNSRCH              6       /* max # domains in search path */
  94 # define LOCALDOMAINPARTS       2       /* min levels in name that is "local" */
  95
  96 # define RES_TIMEOUT            5       /* min. seconds between retries */
  97 # define MAXRESOLVSORT          10      /* number of net to sort on */
  98 # define RES_MAXNDOTS           15      /* should reflect bit field size */
  99 # define RES_MAXRETRANS         30      /* only for resolv.conf/RES_OPTIONS */
 100 # define RES_MAXRETRY           5       /* only for resolv.conf/RES_OPTIONS */
 101 # define RES_DFLRETRY           3       /* Default #/tries. */
 102 /* (glibc uses RES_DFLRETRY of 2 but also does _res.retry = 4 sometimes (!) */
 103 # define RES_MAXTIME            65535   /* Infinity, in milliseconds. */
 104
 105 /* _res (an instance of this structure) uses 0.5kb in bss
 106  * in "ordinary" libc's (glibc, xBSD). We want to be less wasteful.
 107  * We (1) shuffle and shrink some integer fields,
 108  * and (2) can switch off stuff we don't support.
 109  * Everything inside __UCLIBC_HAS_COMPAT_RES_STATE__
 110  * is not actually used by uclibc and can be configured off.
 111  * However, this will prevent some programs from building.
 112  * Really obscure stuff with no observed users in the wild is under
 113  * __UCLIBC_HAS_EXTRA_COMPAT_RES_STATE__.
 114  * I guess it's safe to set that to N.
 115  */
 116 struct __res_state {
 117         /*int retrans, retry; - moved, was here */
 118         u_int32_t options;              /* (was: ulong) option flags - see below. */
 119         struct sockaddr_in nsaddr_list[MAXNS]; /* address of name server */
 120 #define nsaddr nsaddr_list[0]           /* for backward compatibility */
 121         char    *dnsrch[MAXDNSRCH + 1]; /* components of domain to search */
 122         /*char defdname[256]; - moved, was here */
 123         u_int8_t nscount;               /* (was: int) number of name servers */
 124         u_int8_t ndots;                 /* (was: unsigned:4) threshold for initial abs. query */
 125         u_int8_t retrans;               /* (was: int) retransmission time interval */
 126         u_int8_t retry;                 /* (was: int) number of times to retransmit */
 127 #ifdef __UCLIBC_HAS_COMPAT_RES_STATE__
 128         /* googling for "_res.defdname" says it's still sometimes used.
 129          * Pity. It's huge, I want to move it to EXTRA_COMPAT... */
 130         char    defdname[256];          /* default domain (deprecated) */
 131         u_int8_t nsort;                 /* (was: unsigned:4) number of elements in sort_list[] */
 132         u_int16_t pfcode;               /* (was: ulong) RES_PRF_ flags. Used by dig. */
 133         unsigned short id;              /* current message id */
 134         int     res_h_errno;            /* last one set for this context */
 135         struct {
 136                 struct in_addr  addr;
 137                 u_int32_t       mask;
 138         } sort_list[MAXRESOLVSORT];
 139 #endif
 140
 141         /* I assume that the intention is to store all
 142          * DNS servers' addresses here, and duplicate in nsaddr_list[]
 143          * those which have IPv4 address. In the case of IPv4 address
 144          * _u._ext.nsaddrs[x] will point to some nsaddr_list[y],
 145          * otherwise it will point into malloc'ed sockaddr_in6.
 146          * nscount is the number of IPv4 addresses and _u._ext.nscount
 147          * is the number of addresses of all kinds.
 148          *
 149          * If this differs from established usage and you need
 150          * to change this, please describe how it is supposed to work.
 151          */
 152         union {
 153                 struct {
 154 #ifdef __UCLIBC_HAS_IPV6__
 155                         struct sockaddr_in6     *nsaddrs[MAXNS];
 156 #endif
 157                         u_int8_t                nscount; /* (was: u_int16_t) */
 158 #ifdef __UCLIBC_HAS_COMPAT_RES_STATE__
 159                         /* rather obscure, and differs in BSD and glibc */
 160                         u_int16_t               nstimes[MAXNS];
 161                         int                     nssocks[MAXNS];
 162                         u_int16_t               nscount6;
 163                         u_int16_t               nsinit;
 164                         /* glibc also has: */
 165                         /*u_int16_t             nsmap[MAXNS];*/
 166                         /*unsigned long long    initstamp;*/
 167 #endif
 168                 } _ext;
 169         } _u;
 170
 171 #ifdef __UCLIBC_HAS_EXTRA_COMPAT_RES_STATE__
 172         /* Truly obscure stuff.
 173          * Googling for "_res.XXX" for these members
 174          * turned up basically empty */
 175         res_send_qhook qhook;           /* query hook */
 176         res_send_rhook rhook;           /* response hook */
 177         int     _vcsock;                /* PRIVATE: for res_send VC i/o */
 178         unsigned _flags;                /* PRIVATE: see below */
 179 #endif
 180 };
 181
 182 typedef struct __res_state *res_state;
 183 # undef __need_res_state
 184 #endif
 185
 186 #ifdef _RESOLV_H_
 187 /*
 188  * Revision information.  This is the release date in YYYYMMDD format.
 189  * It can change every day so the right thing to do with it is use it
 190  * in preprocessor commands such as "#if (__RES > 19931104)".  Do not
 191  * compare for equality; rather, use it to determine whether your resolver
 192  * is new enough to contain a certain feature.
 193  */
 194
 195 #if 0
 196 #define __RES   19991006
 197 #else
 198 #define __RES   19960801
 199 #endif
 200
 201 /*
 202  * Resolver configuration file.
 203  * Normally not present, but may contain the address of the
 204  * inital name server(s) to query and the domain search list.
 205  */
 206
 207 #ifndef _PATH_RESCONF
 208 #define _PATH_RESCONF        "/etc/resolv.conf"
 209 #endif
 210
 211 struct res_sym {
 212         int     number;         /* Identifying number, like T_MX */
 213         char *  name;           /* Its symbolic name, like "MX" */
 214         char *  humanname;      /* Its fun name, like "mail exchanger" */
 215 };
 216
 217 /*
 218  * Resolver flags (used to be discrete per-module statics ints).
 219  */
 220 #define RES_F_VC        0x00000001      /* socket is TCP */
 221 #define RES_F_CONN      0x00000002      /* socket is connected */
 222
 223 /* res_findzonecut() options */
 224 #define RES_EXHAUSTIVE  0x00000001      /* always do all queries */
 225
 226 /*
 227  * Resolver options (keep these in synch with res_debug.c, please)
 228  * (which of these do we really implement??)
 229  */
 230 #define RES_INIT        0x00000001      /* address initialized */
 231 #define RES_DEBUG       0x00000002      /* print debug messages */
 232 #define RES_AAONLY      0x00000004      /* authoritative answers only (!IMPL)*/
 233 #define RES_USEVC       0x00000008      /* use virtual circuit */
 234 #define RES_PRIMARY     0x00000010      /* query primary server only (!IMPL) */
 235 #define RES_IGNTC       0x00000020      /* ignore trucation errors */
 236 #define RES_RECURSE     0x00000040      /* recursion desired */
 237 #define RES_DEFNAMES    0x00000080      /* use default domain name */
 238 #define RES_STAYOPEN    0x00000100      /* Keep TCP socket open */
 239 #define RES_DNSRCH      0x00000200      /* search up local domain tree */
 240 #define RES_INSECURE1   0x00000400      /* type 1 security disabled */
 241 #define RES_INSECURE2   0x00000800      /* type 2 security disabled */
 242 #define RES_NOALIASES   0x00001000      /* shuts off HOSTALIASES feature */
 243 #define RES_USE_INET6   0x00002000      /* use/map IPv6 in gethostbyname() */
 244 #define RES_ROTATE      0x00004000      /* rotate ns list after each query */
 245 #define RES_NOCHECKNAME 0x00008000      /* do not check names for sanity. */
 246 #define RES_KEEPTSIG    0x00010000      /* do not strip TSIG records */
 247 #define RES_BLAST       0x00020000      /* blast all recursive servers */
 248 #if 0
 249 #define RES_USEBSTRING  0x00040000      /* IPv6 reverse lookup with byte
 250                                            strings */
 251 #define RES_NOIP6DOTINT 0x00080000      /* Do not use .ip6.int in IPv6
 252                                            reverse lookup */
 253
 254 #define RES_DEFAULT     (RES_RECURSE|RES_DEFNAMES|RES_DNSRCH|RES_NOIP6DOTINT)
 255 #else
 256 #define RES_DEFAULT     (RES_RECURSE|RES_DEFNAMES|RES_DNSRCH)
 257 #endif
 258
 259 /*
 260  * Resolver "pfcode" values.  Used by dig.
 261  */
 262 #define RES_PRF_STATS   0x00000001
 263 #define RES_PRF_UPDATE  0x00000002
 264 #define RES_PRF_CLASS   0x00000004
 265 #define RES_PRF_CMD     0x00000008
 266 #define RES_PRF_QUES    0x00000010
 267 #define RES_PRF_ANS     0x00000020
 268 #define RES_PRF_AUTH    0x00000040
 269 #define RES_PRF_ADD     0x00000080
 270 #define RES_PRF_HEAD1   0x00000100
 271 #define RES_PRF_HEAD2   0x00000200
 272 #define RES_PRF_TTLID   0x00000400
 273 #define RES_PRF_HEADX   0x00000800
 274 #define RES_PRF_QUERY   0x00001000
 275 #define RES_PRF_REPLY   0x00002000
 276 #define RES_PRF_INIT    0x00004000
 277 /*                      0x00008000      */
 278
 279 /* Things involving an internal (static) resolver context. */
 280 __BEGIN_DECLS
 281 extern struct __res_state *__res_state(void) __attribute__ ((__const__));
 282 __END_DECLS
 283 #define _res (*__res_state())
 284
 285 #if 0
 286 #define fp_nquery               __fp_nquery
 287 #define fp_query                __fp_query
 288 #define hostalias               __hostalias
 289 #define p_query                 __p_query
 290 #endif
 291 #define res_close               __res_close
 292 #define res_init                __res_init
 293 #if 0
 294 #define res_isourserver         __res_isourserver
 295 #endif
 296 #define res_mkquery             __res_mkquery
 297 #define res_query               __res_query
 298 #define res_querydomain         __res_querydomain
 299 #define res_search              __res_search
 300 #if 0
 301 #define res_send                __res_send
 302 #endif
 303
 304 __BEGIN_DECLS
 305 #if 0
 306 void            fp_nquery (const u_char *, int, FILE *) __THROW;
 307 void            fp_query (const u_char *, FILE *) __THROW;
 308 const char *    hostalias (const char *) __THROW;
 309 void            p_query (const u_char *) __THROW;
 310 #endif
 311 #ifdef __UCLIBC_HAS_BSD_RES_CLOSE__
 312 void            res_close (void) __THROW;
 313 #endif
 314 int             res_init (void) __THROW;
 315 libc_hidden_proto(res_init)
 316 #if 0
 317 int             res_isourserver (const struct sockaddr_in *) __THROW;
 318 #endif
 319 int             res_mkquery (int, const char *, int, int, const u_char *,
 320                              int, const u_char *, u_char *, int) __THROW;
 321 int             res_query (const char *, int, int, u_char *, int) __THROW;
 322 libc_hidden_proto(res_query)
 323 int             res_querydomain (const char *, const char *, int, int,
 324                                  u_char *, int) __THROW;
 325 libc_hidden_proto(res_querydomain)
 326 int             res_search (const char *, int, int, u_char *, int) __THROW;
 327 #if 0
 328 int             res_send (const u_char *, int, u_char *, int) __THROW;
 329 #endif
 330 __END_DECLS
 331
 332 #if 0
 333 #define b64_ntop                __b64_ntop
 334 #define b64_pton                __b64_pton
 335 #define dn_count_labels         __dn_count_labels
 336 #endif
 337 #define dn_comp                 __dn_comp
 338 #define dn_expand               __dn_expand
 339 #define dn_skipname             __dn_skipname
 340 #define res_ninit               __res_ninit
 341 #define res_nclose              __res_nclose
 342 #if 0
 343 #define fp_resstat              __fp_resstat
 344 #define loc_aton                __loc_aton
 345 #define loc_ntoa                __loc_ntoa
 346 #define p_cdname                __p_cdname
 347 #define p_cdnname               __p_cdnname
 348 #define p_class                 __p_class
 349 #define p_fqname                __p_fqname
 350 #define p_fqnname               __p_fqnname
 351 #define p_option                __p_option
 352 #define p_secstodate            __p_secstodate
 353 #define p_section               __p_section
 354 #define p_time                  __p_time
 355 #define p_type                  __p_type
 356 #define p_rcode                 __p_rcode
 357 #define putlong                 __putlong
 358 #define putshort                __putshort
 359 #define res_dnok                __res_dnok
 360 #define res_hnok                __res_hnok
 361 #define res_hostalias           __res_hostalias
 362 #define res_mailok              __res_mailok
 363 #define res_nameinquery         __res_nameinquery
 364 #define res_nmkquery            __res_nmkquery
 365 #define res_npquery             __res_npquery
 366 #define res_nquery              __res_nquery
 367 #define res_nquerydomain        __res_nquerydomain
 368 #define res_nsearch             __res_nsearch
 369 #define res_nsend               __res_nsend
 370 #define res_nisourserver        __res_nisourserver
 371 #define res_ownok               __res_ownok
 372 #define res_queriesmatch        __res_queriesmatch
 373 #define res_randomid            __res_randomid
 374 #define sym_ntop                __sym_ntop
 375 #define sym_ntos                __sym_ntos
 376 #define sym_ston                __sym_ston
 377 #endif
 378 __BEGIN_DECLS
 379 #if 0
 380 int             res_hnok (const char *) __THROW;
 381 int             res_ownok (const char *) __THROW;
 382 int             res_mailok (const char *) __THROW;
 383 int             res_dnok (const char *) __THROW;
 384 int             sym_ston (const struct res_sym *, const char *, int *) __THROW;
 385 const char *    sym_ntos (const struct res_sym *, int, int *) __THROW;
 386 const char *    sym_ntop (const struct res_sym *, int, int *) __THROW;
 387 int             b64_ntop (u_char const *, size_t, char *, size_t) __THROW;
 388 int             b64_pton (char const *, u_char *, size_t) __THROW;
 389 int             loc_aton (const char *ascii, u_char *binary) __THROW;
 390 const char *    loc_ntoa (const u_char *binary, char *ascii) __THROW;
 391 void            putlong (u_int32_t, u_char *) __THROW;
 392 void            putshort (u_int16_t, u_char *) __THROW;
 393 const char *    p_class (int) __THROW;
 394 const char *    p_time (u_int32_t) __THROW;
 395 const char *    p_type (int) __THROW;
 396 const char *    p_rcode (int) __THROW;
 397 const u_char *  p_cdnname (const u_char *, const u_char *, int, FILE *)
 398      __THROW;
 399 const u_char *  p_cdname (const u_char *, const u_char *, FILE *) __THROW;
 400 const u_char *  p_fqnname (const u_char *cp, const u_char *msg,
 401                            int, char *, int) __THROW;
 402 const u_char *  p_fqname (const u_char *, const u_char *, FILE *) __THROW;
 403 const char *    p_option (u_long option) __THROW;
 404 char *          p_secstodate (u_long) __THROW;
 405 int             dn_count_labels (const char *) __THROW;
 406 #endif
 407 int             dn_skipname (const u_char *, const u_char *) __THROW;
 408 libc_hidden_proto(dn_skipname)
 409 int             dn_comp (const char *, u_char *, int, u_char **, u_char **)
 410      __THROW;
 411 libc_hidden_proto(dn_comp)
 412 int             dn_expand (const u_char *, const u_char *, const u_char *,
 413                            char *, int) __THROW;
 414 libc_hidden_proto(dn_expand)
 415 int             res_ninit (res_state) __THROW;
 416 void            res_nclose (res_state) __THROW;
 417 #if 0
 418 u_int           res_randomid (void) __THROW;
 419 int             res_nameinquery (const char *, int, int,
 420                                  const u_char *, const u_char *) __THROW;
 421 int             res_queriesmatch (const u_char *, const u_char *,
 422                                   const u_char *, const u_char *) __THROW;
 423 const char *    p_section (int section, int opcode) __THROW;
 424 /* Things involving a resolver context. */
 425 int             res_nisourserver (const res_state,
 426                                   const struct sockaddr_in *) __THROW;
 427 void            fp_resstat (const res_state, FILE *) __THROW;
 428 void            res_npquery (const res_state, const u_char *, int, FILE *)
 429      __THROW;
 430 const char *    res_hostalias (const res_state, const char *, char *, size_t)
 431      __THROW;
 432 int             res_nquery (res_state, const char *, int, int, u_char *, int)
 433      __THROW;
 434 int             res_nsearch (res_state, const char *, int, int, u_char *, int)
 435      __THROW;
 436 int             res_nquerydomain (res_state, const char *, const char *, int,
 437                                   int, u_char *, int) __THROW;
 438 int             res_nmkquery (res_state, int, const char *, int, int,
 439                               const u_char *, int, const u_char *, u_char *,
 440                               int) __THROW;
 441 int             res_nsend (res_state, const u_char *, int, u_char *, int)
 442      __THROW;
 443 #endif
 444 __END_DECLS
 445
 446 # if _LIBC
 447 #  ifdef __UCLIBC_HAS_THREADS__
 448 #   if defined __UCLIBC_HAS_TLS__ \
 449                && (!defined NOT_IN_libc || defined IS_IN_libpthread)
 450 #    undef _res
 451 #    ifndef NOT_IN_libc
 452 #     define __resp __libc_resp
 453 #    endif
 454 #    define _res (*__resp)
 455 extern __thread struct __res_state *__resp attribute_tls_model_ie;
 456 #   endif
 457 #  else
 458 #   undef _res
 459 #   define _res (*__resp)
 460 extern struct __res_state *__resp;
 461 #  endif /* __UCLIBC_HAS_THREADS__ */
 462 # endif /* _LIBC */
 463
 464 #endif /* _RESOLV_H_ */
 465
 466 #endif /* !_RESOLV_H_ */