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 const char *_res_opcodes[] = {
  43         "QUERY",
  44         "IQUERY",
  45         "CQUERYM",
  46         "CQUERYU",      /* experimental */
  47         "NOTIFY",       /* experimental */
  48         "UPDATE",
  49         "6",
  50         "7",
  51         "8",
  52         "9",
  53         "10",
  54         "11",
  55         "12",
  56         "13",
  57         "ZONEINIT",
  58         "ZONEREF",
  59 };
  60
  61 #ifdef BIND_UPDATE
  62 const char *_res_sectioncodes[] = {
  63         "ZONE",
  64         "PREREQUISITES",
  65         "UPDATE",
  66         "ADDITIONAL",
  67 };
  68 #endif
  69
  70 #ifndef __BIND_NOSTATIC
  71 #ifdef _LIBC
  72 /* The definition has been moved to res_libc.c.  */
  73 #else
  74 #undef _res
  75 struct __res_state _res
  76 # if defined(__BIND_RES_TEXT)
  77         = { RES_TIMEOUT, }      /* Motorola, et al. */
  78 # endif
  79         ;
  80 #endif
  81
  82 /* Proto. */
  83 #ifndef _LIBC
  84 int  res_ourserver_p(const res_state, const struct sockaddr_in *);
  85 void res_pquery(const res_state, const u_char *, int, FILE *);
  86 #endif
  87
  88 #ifndef _LIBC
  89 /* Moved to res_libc.c since res_init() should go into libc.so but the
  90    rest of this file not.  */
  91 int
  92 res_init(void) {
  93         extern int __res_vinit(res_state, int);
  94
  95         /*
  96          * These three fields used to be statically initialized.  This made
  97          * it hard to use this code in a shared library.  It is necessary,
  98          * now that we're doing dynamic initialization here, that we preserve
  99          * the old semantics: if an application modifies one of these three
 100          * fields of _res before res_init() is called, res_init() will not
 101          * alter them.  Of course, if an application is setting them to
 102          * _zero_ before calling res_init(), hoping to override what used
 103          * to be the static default, we can't detect it and unexpected results
 104          * will follow.  Zero for any of these fields would make no sense,
 105          * so one can safely assume that the applications were already getting
 106          * unexpected results.
 107          *
 108          * _res.options is tricky since some apps were known to diddle the bits
 109          * before res_init() was first called. We can't replicate that semantic
 110          * with dynamic initialization (they may have turned bits off that are
 111          * set in RES_DEFAULT).  Our solution is to declare such applications
 112          * "broken".  They could fool us by setting RES_INIT but none do (yet).
 113          */
 114         if (!_res.retrans)
 115                 _res.retrans = RES_TIMEOUT;
 116         if (!_res.retry)
 117                 _res.retry = 4;
 118         if (!(_res.options & RES_INIT))
 119                 _res.options = RES_DEFAULT;
 120
 121         /*
 122          * This one used to initialize implicitly to zero, so unless the app
 123          * has set it to something in particular, we can randomize it now.
 124          */
 125         if (!_res.id)
 126                 _res.id = res_randomid();
 127
 128         return (__res_vinit(&_res, 1));
 129 }
 130 #endif
 131
 132 void
 133 p_query(const u_char *msg) {
 134         fp_query(msg, stdout);
 135 }
 136
 137 void
 138 fp_query(const u_char *msg, FILE *file) {
 139         fp_nquery(msg, PACKETSZ, file);
 140 }
 141
 142 void
 143 fp_nquery(const u_char *msg, int len, FILE *file) {
 144         if ((_res.options & RES_INIT) == 0 && __res_ninit(&_res) == -1)
 145                 return;
 146
 147         res_pquery(&_res, msg, len, file);
 148 }
 149
 150 int
 151 res_mkquery(int op,                     /* opcode of query */
 152             const char *dname,          /* domain name */
 153             int class, int type,        /* class and type of query */
 154             const u_char *data,         /* resource record data */
 155             int datalen,                /* length of data */
 156             const u_char *newrr_in,     /* new rr for modify or append */
 157             u_char *buf,                /* buffer to put query */
 158             int buflen)                 /* size of buffer */
 159 {
 160         if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
 161                 RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
 162                 return (-1);
 163         }
 164         return (res_nmkquery(&_res, op, dname, class, type,
 165                              data, datalen,
 166                              newrr_in, buf, buflen));
 167 }
 168
 169 #ifdef BIND_UPDATE
 170 int
 171 res_mkupdate(ns_updrec *rrecp_in, u_char *buf, int buflen) {
 172         if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
 173                 RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
 174                 return (-1);
 175         }
 176
 177         return (res_nmkupdate(&_res, rrecp_in, buf, buflen));
 178 }
 179 #endif
 180
 181 int
 182 res_query(const char *name,     /* domain name */
 183           int class, int type,  /* class and type of query */
 184           u_char *answer,       /* buffer to put answer */
 185           int anslen)           /* size of answer buffer */
 186 {
 187         if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
 188                 RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
 189                 return (-1);
 190         }
 191         return (res_nquery(&_res, name, class, type, answer, anslen));
 192 }
 193
 194 void
 195 res_send_setqhook(res_send_qhook hook) {
 196         _res.qhook = hook;
 197 }
 198
 199 void
 200 res_send_setrhook(res_send_rhook hook) {
 201         _res.rhook = hook;
 202 }
 203
 204 int
 205 res_isourserver(const struct sockaddr_in *inp) {
 206         return (res_ourserver_p(&_res, (const struct sockaddr_in6 *) inp));
 207 }
 208
 209 int
 210 res_send(const u_char *buf, int buflen, u_char *ans, int anssiz) {
 211         if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
 212                 /* errno should have been set by res_init() in this case. */
 213                 return (-1);
 214         }
 215
 216         return (res_nsend(&_res, buf, buflen, ans, anssiz));
 217 }
 218
 219 #ifndef _LIBC
 220 int
 221 res_sendsigned(const u_char *buf, int buflen, ns_tsig_key *key,
 222                u_char *ans, int anssiz)
 223 {
 224         if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
 225                 /* errno should have been set by res_init() in this case. */
 226                 return (-1);
 227         }
 228
 229         return (res_nsendsigned(&_res, buf, buflen, key, ans, anssiz));
 230 }
 231 #endif
 232
 233 void
 234 res_close(void) {
 235 #ifdef _LIBC
 236         /*
 237          * Some stupid programs out there call res_close() before res_init().
 238          * Since _res._vcsock isn't explicitly initialized, these means that
 239          * we could do a close(0), which might lead to some security problems.
 240          * Therefore we check if res_init() was called before by looking at
 241          * the RES_INIT bit in _res.options.  If it hasn't been set we bail out
 242          * early.  */
 243         if ((_res.options & RES_INIT) == 0)
 244           return;
 245 #endif
 246         res_nclose(&_res);
 247 }
 248
 249 #ifdef BIND_UPDATE
 250 int
 251 res_update(ns_updrec *rrecp_in) {
 252         if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
 253                 RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
 254                 return (-1);
 255         }
 256
 257         return (res_nupdate(&_res, rrecp_in, NULL));
 258 }
 259 #endif
 260
 261 int
 262 res_search(const char *name,    /* domain name */
 263            int class, int type, /* class and type of query */
 264            u_char *answer,      /* buffer to put answer */
 265            int anslen)          /* size of answer */
 266 {
 267         if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
 268                 RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
 269                 return (-1);
 270         }
 271
 272         return (res_nsearch(&_res, name, class, type, answer, anslen));
 273 }
 274
 275 int
 276 res_querydomain(const char *name,
 277                 const char *domain,
 278                 int class, int type,    /* class and type of query */
 279                 u_char *answer,         /* buffer to put answer */
 280                 int anslen)             /* size of answer */
 281 {
 282         if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
 283                 RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
 284                 return (-1);
 285         }
 286
 287         return (res_nquerydomain(&_res, name, domain,
 288                                  class, type,
 289                                  answer, anslen));
 290 }
 291
 292 const char *
 293 hostalias(const char *name) {
 294         static char abuf[MAXDNAME];
 295
 296         return (res_hostalias(&_res, name, abuf, sizeof abuf));
 297 }
 298
 299 #ifdef ultrix
 300 int
 301 local_hostname_length(const char *hostname) {
 302         int len_host, len_domain;
 303
 304         if (!*_res.defdname)
 305                 res_init();
 306         len_host = strlen(hostname);
 307         len_domain = strlen(_res.defdname);
 308         if (len_host > len_domain &&
 309             !strcasecmp(hostname + len_host - len_domain, _res.defdname) &&
 310             hostname[len_host - len_domain - 1] == '.')
 311                 return (len_host - len_domain - 1);
 312         return (0);
 313 }
 314 #endif /*ultrix*/
 315
 316 #endif
 317 \f
 318
 319 #include <shlib-compat.h>
 320
 321 #if SHLIB_COMPAT(libresolv, GLIBC_2_0, GLIBC_2_2)
 322 # undef res_mkquery
 323 # undef res_query
 324 # undef res_querydomain
 325 # undef res_search
 326 weak_alias (__res_mkquery, res_mkquery);
 327 weak_alias (__res_query, res_query);
 328 weak_alias (__res_querydomain, res_querydomain);
 329 weak_alias (__res_search, res_search);
 330 #endif