resolv/res_data.c

   1 /*
   2  * Copyright (c) 1995-1999 by Internet Software Consortium.
   3  *
   4  * Permission to use, copy, modify, and distribute this software for any
   5  * purpose with or without fee is hereby granted, provided that the above
   6  * copyright notice and this permission notice appear in all copies.
   7  *
   8  * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
   9  * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
  10  * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
  11  * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
  12  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
  13  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
  14  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
  15  * SOFTWARE.
  16  */
  17
  18 #if defined(LIBC_SCCS) && !defined(lint)
  19 static const char rcsid[] = "$BINDId: res_data.c,v 8.17 1999/10/13 17:11:31 vixie Exp $";
  20 #endif /* LIBC_SCCS and not lint */
  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 #ifdef BIND_UPDATE
  35 #include <res_update.h>
  36 #endif
  37 #include <stdio.h>
  38 #include <stdlib.h>
  39 #include <string.h>
  40 #include <unistd.h>
  41
  42 #undef _res
  43
  44 const char *_res_opcodes[] = {
  45         "QUERY",
  46         "IQUERY",
  47         "CQUERYM",
  48         "CQUERYU",      /* experimental */
  49         "NOTIFY",       /* experimental */
  50         "UPDATE",
  51         "6",
  52         "7",
  53         "8",
  54         "9",
  55         "10",
  56         "11",
  57         "12",
  58         "13",
  59         "ZONEINIT",
  60         "ZONEREF",
  61 };
  62
  63 #ifdef BIND_UPDATE
  64 const char *_res_sectioncodes[] = {
  65         "ZONE",
  66         "PREREQUISITES",
  67         "UPDATE",
  68         "ADDITIONAL",
  69 };
  70 #endif
  71
  72 #ifndef __BIND_NOSTATIC
  73 #ifdef _LIBC
  74 extern struct __res_state _res;
  75 #else
  76 /* The definition has been moved to res_libc.c.  */
  77 struct __res_state _res
  78 # if defined(__BIND_RES_TEXT)
  79         = { RES_TIMEOUT, }      /* Motorola, et al. */
  80 # endif
  81         ;
  82 #endif
  83
  84 /* Proto. */
  85 #ifndef _LIBC
  86 int  res_ourserver_p(const res_state, const struct sockaddr_in *);
  87 void res_pquery(const res_state, const u_char *, int, FILE *);
  88 #endif
  89
  90 #ifndef _LIBC
  91 /* Moved to res_libc.c since res_init() should go into libc.so but the
  92    rest of this file not.  */
  93 int
  94 res_init(void) {
  95         extern int __res_vinit(res_state, int);
  96
  97         /*
  98          * These three fields used to be statically initialized.  This made
  99          * it hard to use this code in a shared library.  It is necessary,
 100          * now that we're doing dynamic initialization here, that we preserve
 101          * the old semantics: if an application modifies one of these three
 102          * fields of _res before res_init() is called, res_init() will not
 103          * alter them.  Of course, if an application is setting them to
 104          * _zero_ before calling res_init(), hoping to override what used
 105          * to be the static default, we can't detect it and unexpected results
 106          * will follow.  Zero for any of these fields would make no sense,
 107          * so one can safely assume that the applications were already getting
 108          * unexpected results.
 109          *
 110          * _res.options is tricky since some apps were known to diddle the bits
 111          * before res_init() was first called. We can't replicate that semantic
 112          * with dynamic initialization (they may have turned bits off that are
 113          * set in RES_DEFAULT).  Our solution is to declare such applications
 114          * "broken".  They could fool us by setting RES_INIT but none do (yet).
 115          */
 116         if (!_res.retrans)
 117                 _res.retrans = RES_TIMEOUT;
 118         if (!_res.retry)
 119                 _res.retry = 4;
 120         if (!(_res.options & RES_INIT))
 121                 _res.options = RES_DEFAULT;
 122
 123         /*
 124          * This one used to initialize implicitly to zero, so unless the app
 125          * has set it to something in particular, we can randomize it now.
 126          */
 127         if (!_res.id)
 128                 _res.id = res_randomid();
 129
 130         return (__res_vinit(&_res, 1));
 131 }
 132 #endif
 133
 134 void
 135 p_query(const u_char *msg) {
 136         fp_query(msg, stdout);
 137 }
 138
 139 void
 140 fp_query(const u_char *msg, FILE *file) {
 141         fp_nquery(msg, PACKETSZ, file);
 142 }
 143
 144 void
 145 fp_nquery(const u_char *msg, int len, FILE *file) {
 146         if ((_res.options & RES_INIT) == 0 && __res_ninit(&_res) == -1)
 147                 return;
 148
 149         res_pquery(&_res, msg, len, file);
 150 }
 151
 152 int
 153 res_mkquery(int op,                     /* opcode of query */
 154             const char *dname,          /* domain name */
 155             int class, int type,        /* class and type of query */
 156             const u_char *data,         /* resource record data */
 157             int datalen,                /* length of data */
 158             const u_char *newrr_in,     /* new rr for modify or append */
 159             u_char *buf,                /* buffer to put query */
 160             int buflen)                 /* size of buffer */
 161 {
 162         if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
 163                 RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
 164                 return (-1);
 165         }
 166         return (res_nmkquery(&_res, op, dname, class, type,
 167                              data, datalen,
 168                              newrr_in, buf, buflen));
 169 }
 170
 171 #ifdef BIND_UPDATE
 172 int
 173 res_mkupdate(ns_updrec *rrecp_in, u_char *buf, int buflen) {
 174         if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
 175                 RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
 176                 return (-1);
 177         }
 178
 179         return (res_nmkupdate(&_res, rrecp_in, buf, buflen));
 180 }
 181 #endif
 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) == 0 && 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 void
 197 res_send_setqhook(res_send_qhook hook) {
 198         _res.qhook = hook;
 199 }
 200
 201 void
 202 res_send_setrhook(res_send_rhook hook) {
 203         _res.rhook = hook;
 204 }
 205
 206 int
 207 res_isourserver(const struct sockaddr_in *inp) {
 208         return (res_ourserver_p(&_res, (const struct sockaddr_in6 *) inp));
 209 }
 210
 211 int
 212 res_send(const u_char *buf, int buflen, u_char *ans, int anssiz) {
 213         if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
 214                 /* errno should have been set by res_init() in this case. */
 215                 return (-1);
 216         }
 217
 218         return (res_nsend(&_res, buf, buflen, ans, anssiz));
 219 }
 220
 221 #ifndef _LIBC
 222 int
 223 res_sendsigned(const u_char *buf, int buflen, ns_tsig_key *key,
 224                u_char *ans, int anssiz)
 225 {
 226         if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
 227                 /* errno should have been set by res_init() in this case. */
 228                 return (-1);
 229         }
 230
 231         return (res_nsendsigned(&_res, buf, buflen, key, ans, anssiz));
 232 }
 233 #endif
 234
 235 void
 236 res_close(void) {
 237 #ifdef _LIBC
 238         /*
 239          * Some stupid programs out there call res_close() before res_init().
 240          * Since _res._vcsock isn't explicitly initialized, these means that
 241          * we could do a close(0), which might lead to some security problems.
 242          * Therefore we check if res_init() was called before by looking at
 243          * the RES_INIT bit in _res.options.  If it hasn't been set we bail out
 244          * early.  */
 245         if ((_res.options & RES_INIT) == 0)
 246           return;
 247 #endif
 248         res_nclose(&_res);
 249 }
 250
 251 #ifdef BIND_UPDATE
 252 int
 253 res_update(ns_updrec *rrecp_in) {
 254         if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
 255                 RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
 256                 return (-1);
 257         }
 258
 259         return (res_nupdate(&_res, rrecp_in, NULL));
 260 }
 261 #endif
 262
 263 int
 264 res_search(const char *name,    /* domain name */
 265            int class, int type, /* class and type of query */
 266            u_char *answer,      /* buffer to put answer */
 267            int anslen)          /* size of answer */
 268 {
 269         if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
 270                 RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
 271                 return (-1);
 272         }
 273
 274         return (res_nsearch(&_res, name, class, type, answer, anslen));
 275 }
 276
 277 int
 278 res_querydomain(const char *name,
 279                 const char *domain,
 280                 int class, int type,    /* class and type of query */
 281                 u_char *answer,         /* buffer to put answer */
 282                 int anslen)             /* size of answer */
 283 {
 284         if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
 285                 RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
 286                 return (-1);
 287         }
 288
 289         return (res_nquerydomain(&_res, name, domain,
 290                                  class, type,
 291                                  answer, anslen));
 292 }
 293
 294 const char *
 295 hostalias(const char *name) {
 296         static char abuf[MAXDNAME];
 297
 298         return (res_hostalias(&_res, name, abuf, sizeof abuf));
 299 }
 300
 301 #ifdef ultrix
 302 int
 303 local_hostname_length(const char *hostname) {
 304         int len_host, len_domain;
 305
 306         if (!*_res.defdname)
 307                 res_init();
 308         len_host = strlen(hostname);
 309         len_domain = strlen(_res.defdname);
 310         if (len_host > len_domain &&
 311             !strcasecmp(hostname + len_host - len_domain, _res.defdname) &&
 312             hostname[len_host - len_domain - 1] == '.')
 313                 return (len_host - len_domain - 1);
 314         return (0);
 315 }
 316 #endif /*ultrix*/
 317
 318 #endif
 319 \f
 320
 321 #include <shlib-compat.h>
 322
 323 #if SHLIB_COMPAT(libresolv, GLIBC_2_0, GLIBC_2_2)
 324 # undef res_mkquery
 325 # undef res_query
 326 # undef res_querydomain
 327 # undef res_search
 328 weak_alias (__res_mkquery, res_mkquery);
 329 weak_alias (__res_query, res_query);
 330 weak_alias (__res_querydomain, res_querydomain);
 331 weak_alias (__res_search, res_search);
 332 #endif