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 libresolv_hidden_data_def (_res_opcodes)
  61
  62 #ifdef BIND_UPDATE
  63 const char *_res_sectioncodes[] attribute_hidden = {
  64         "ZONE",
  65         "PREREQUISITES",
  66         "UPDATE",
  67         "ADDITIONAL",
  68 };
  69 #endif
  70
  71 #ifndef __BIND_NOSTATIC
  72 #ifdef _LIBC
  73 /* The definition has been moved to res_libc.c.  */
  74 #else
  75 #undef _res
  76 struct __res_state _res
  77 # if defined(__BIND_RES_TEXT)
  78         = { RES_TIMEOUT, }      /* Motorola, et al. */
  79 # endif
  80         ;
  81 #endif
  82
  83 /* Proto. */
  84 #ifndef _LIBC
  85 int  res_ourserver_p(const res_state, const struct sockaddr_in *);
  86 void res_pquery(const res_state, const u_char *, int, FILE *);
  87 #endif
  88
  89 #ifndef _LIBC
  90 /* Moved to res_libc.c since res_init() should go into libc.so but the
  91    rest of this file not.  */
  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                 _res.retry = 4;
 119         if (!(_res.options & RES_INIT))
 120                 _res.options = RES_DEFAULT;
 121
 122         /*
 123          * This one used to initialize implicitly to zero, so unless the app
 124          * has set it to something in particular, we can randomize it now.
 125          */
 126         if (!_res.id)
 127                 _res.id = res_randomid();
 128
 129         return (__res_vinit(&_res, 1));
 130 }
 131 #endif
 132
 133 void
 134 p_query(const u_char *msg) {
 135         fp_query(msg, stdout);
 136 }
 137
 138 void
 139 fp_query(const u_char *msg, FILE *file) {
 140         fp_nquery(msg, PACKETSZ, file);
 141 }
 142 libresolv_hidden_def (fp_query)
 143
 144 void
 145 fp_nquery(const u_char *msg, int len, FILE *file) {
 146         if (__res_maybe_init (&_res, 0) == -1)
 147                 return;
 148
 149         res_pquery(&_res, msg, len, file);
 150 }
 151 libresolv_hidden_def (fp_nquery)
 152
 153 int
 154 res_mkquery(int op,                     /* opcode of query */
 155             const char *dname,          /* domain name */
 156             int class, int type,        /* class and type of query */
 157             const u_char *data,         /* resource record data */
 158             int datalen,                /* length of data */
 159             const u_char *newrr_in,     /* new rr for modify or append */
 160             u_char *buf,                /* buffer to put query */
 161             int buflen)                 /* size of buffer */
 162 {
 163         if (__res_maybe_init (&_res, 1) == -1) {
 164                 RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
 165                 return (-1);
 166         }
 167         return (res_nmkquery(&_res, op, dname, class, type,
 168                              data, datalen,
 169                              newrr_in, buf, buflen));
 170 }
 171
 172 #ifdef BIND_UPDATE
 173 int
 174 res_mkupdate(ns_updrec *rrecp_in, u_char *buf, int buflen) {
 175         if (__res_maybe_init (&_res, 1) == -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 #endif
 183
 184 int
 185 res_query(const char *name,     /* domain name */
 186           int class, int type,  /* class and type of query */
 187           u_char *answer,       /* buffer to put answer */
 188           int anslen)           /* size of answer buffer */
 189 {
 190         if (__res_maybe_init (&_res, 1) == -1) {
 191                 RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
 192                 return (-1);
 193         }
 194         return (res_nquery(&_res, name, class, type, answer, anslen));
 195 }
 196
 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
 207 int
 208 res_isourserver(const struct sockaddr_in *inp) {
 209         return (res_ourserver_p(&_res, (const struct sockaddr_in6 *) inp));
 210 }
 211
 212 int
 213 res_send(const u_char *buf, int buflen, u_char *ans, int anssiz) {
 214         if (__res_maybe_init (&_res, 1) == -1) {
 215                 /* errno should have been set by res_init() in this case. */
 216                 return (-1);
 217         }
 218
 219         return (res_nsend(&_res, buf, buflen, ans, anssiz));
 220 }
 221
 222 #ifndef _LIBC
 223 int
 224 res_sendsigned(const u_char *buf, int buflen, ns_tsig_key *key,
 225                u_char *ans, int anssiz)
 226 {
 227         if (__res_maybe_init (&_res, 1) == -1) {
 228                 /* errno should have been set by res_init() in this case. */
 229                 return (-1);
 230         }
 231
 232         return (res_nsendsigned(&_res, buf, buflen, key, ans, anssiz));
 233 }
 234 #endif
 235
 236 void
 237 res_close(void) {
 238 #ifdef _LIBC
 239         /*
 240          * Some stupid programs out there call res_close() before res_init().
 241          * Since _res._vcsock isn't explicitly initialized, these means that
 242          * we could do a close(0), which might lead to some security problems.
 243          * Therefore we check if res_init() was called before by looking at
 244          * the RES_INIT bit in _res.options.  If it hasn't been set we bail out
 245          * early.  */
 246         if ((_res.options & RES_INIT) == 0)
 247           return;
 248 #endif
 249         /* We don't free the name server addresses because we never
 250            did it and it would be done implicitly on shutdown.  */
 251         __res_iclose(&_res, false);
 252 }
 253
 254 #ifdef BIND_UPDATE
 255 int
 256 res_update(ns_updrec *rrecp_in) {
 257         if (__res_maybe_init (&_res, 1) == -1) {
 258                 RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
 259                 return (-1);
 260         }
 261
 262         return (res_nupdate(&_res, rrecp_in, NULL));
 263 }
 264 #endif
 265
 266 int
 267 res_search(const char *name,    /* domain name */
 268            int class, int type, /* class and type of query */
 269            u_char *answer,      /* buffer to put answer */
 270            int anslen)          /* size of answer */
 271 {
 272         if (__res_maybe_init (&_res, 1) == -1) {
 273                 RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
 274                 return (-1);
 275         }
 276
 277         return (res_nsearch(&_res, name, class, type, answer, anslen));
 278 }
 279
 280 int
 281 res_querydomain(const char *name,
 282                 const char *domain,
 283                 int class, int type,    /* class and type of query */
 284                 u_char *answer,         /* buffer to put answer */
 285                 int anslen)             /* size of answer */
 286 {
 287         if (__res_maybe_init (&_res, 1) == -1) {
 288                 RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
 289                 return (-1);
 290         }
 291
 292         return (res_nquerydomain(&_res, name, domain,
 293                                  class, type,
 294                                  answer, anslen));
 295 }
 296
 297 const char *
 298 hostalias(const char *name) {
 299         static char abuf[MAXDNAME];
 300
 301         return (res_hostalias(&_res, name, abuf, sizeof abuf));
 302 }
 303 libresolv_hidden_def (hostalias)
 304
 305 #ifdef ultrix
 306 int
 307 local_hostname_length(const char *hostname) {
 308         int len_host, len_domain;
 309
 310         if (!*_res.defdname)
 311                 res_init();
 312         len_host = strlen(hostname);
 313         len_domain = strlen(_res.defdname);
 314         if (len_host > len_domain &&
 315             !strcasecmp(hostname + len_host - len_domain, _res.defdname) &&
 316             hostname[len_host - len_domain - 1] == '.')
 317                 return (len_host - len_domain - 1);
 318         return (0);
 319 }
 320 #endif /*ultrix*/
 321
 322 #endif
 323 \f
 324
 325 #include <shlib-compat.h>
 326
 327 #if SHLIB_COMPAT(libresolv, GLIBC_2_0, GLIBC_2_2)
 328 # undef res_mkquery
 329 # undef res_query
 330 # undef res_querydomain
 331 # undef res_search
 332 weak_alias (__res_mkquery, res_mkquery);
 333 weak_alias (__res_query, res_query);
 334 weak_alias (__res_querydomain, res_querydomain);
 335 weak_alias (__res_search, res_search);
 336 #endif