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
  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
  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
 143 void
 144 fp_nquery(const u_char *msg, int len, FILE *file) {
 145         if ((_res.options & RES_INIT) == 0 && res_init() == -1)
 146                 return;
 147
 148         res_pquery(&_res, msg, len, file);
 149 }
 150
 151 int
 152 res_mkquery(int op,                     /* opcode of query */
 153             const char *dname,          /* domain name */
 154             int class, int type,        /* class and type of query */
 155             const u_char *data,         /* resource record data */
 156             int datalen,                /* length of data */
 157             const u_char *newrr_in,     /* new rr for modify or append */
 158             u_char *buf,                /* buffer to put query */
 159             int buflen)                 /* size of buffer */
 160 {
 161         if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
 162                 RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
 163                 return (-1);
 164         }
 165         return (res_nmkquery(&_res, op, dname, class, type,
 166                              data, datalen,
 167                              newrr_in, buf, buflen));
 168 }
 169
 170 #ifdef BIND_UPDATE
 171 int
 172 res_mkupdate(ns_updrec *rrecp_in, u_char *buf, int buflen) {
 173         if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
 174                 RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
 175                 return (-1);
 176         }
 177
 178         return (res_nmkupdate(&_res, rrecp_in, buf, buflen));
 179 }
 180 #endif
 181
 182 int
 183 res_query(const char *name,     /* domain name */
 184           int class, int type,  /* class and type of query */
 185           u_char *answer,       /* buffer to put answer */
 186           int anslen)           /* size of answer buffer */
 187 {
 188         if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
 189                 RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
 190                 return (-1);
 191         }
 192         return (res_nquery(&_res, name, class, type, answer, anslen));
 193 }
 194
 195 void
 196 res_send_setqhook(res_send_qhook hook) {
 197         _res.qhook = hook;
 198 }
 199
 200 void
 201 res_send_setrhook(res_send_rhook hook) {
 202         _res.rhook = hook;
 203 }
 204
 205 int
 206 res_isourserver(const struct sockaddr_in *inp) {
 207         return (res_ourserver_p(&_res, inp));
 208 }
 209
 210 int
 211 res_send(const u_char *buf, int buflen, u_char *ans, int anssiz) {
 212         if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
 213                 /* errno should have been set by res_init() in this case. */
 214                 return (-1);
 215         }
 216
 217         return (res_nsend(&_res, buf, buflen, ans, anssiz));
 218 }
 219
 220 #ifndef _LIBC
 221 int
 222 res_sendsigned(const u_char *buf, int buflen, ns_tsig_key *key,
 223                u_char *ans, int anssiz)
 224 {
 225         if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
 226                 /* errno should have been set by res_init() in this case. */
 227                 return (-1);
 228         }
 229
 230         return (res_nsendsigned(&_res, buf, buflen, key, ans, anssiz));
 231 }
 232 #endif
 233
 234 void
 235 res_close(void) {
 236 #ifdef _LIBC
 237         /*
 238          * Some stupid programs out there call res_close() before res_init().
 239          * Since _res._vcsock isn't explicitly initialized, these means that
 240          * we could do a close(0), which might lead to some security problems.
 241          * Therefore we check if res_init() was called before by looking at
 242          * the RES_INIT bit in _res.options.  If it hasn't been set we bail out
 243          * early.  */
 244         if ((_res.options & RES_INIT) == 0)
 245           return;
 246 #endif
 247         res_nclose(&_res);
 248 }
 249
 250 #ifdef BIND_UPDATE
 251 int
 252 res_update(ns_updrec *rrecp_in) {
 253         if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
 254                 RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
 255                 return (-1);
 256         }
 257
 258         return (res_nupdate(&_res, rrecp_in, NULL));
 259 }
 260 #endif
 261
 262 int
 263 res_search(const char *name,    /* domain name */
 264            int class, int type, /* class and type of query */
 265            u_char *answer,      /* buffer to put answer */
 266            int anslen)          /* size of answer */
 267 {
 268         if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
 269                 RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
 270                 return (-1);
 271         }
 272
 273         return (res_nsearch(&_res, name, class, type, answer, anslen));
 274 }
 275
 276 int
 277 res_querydomain(const char *name,
 278                 const char *domain,
 279                 int class, int type,    /* class and type of query */
 280                 u_char *answer,         /* buffer to put answer */
 281                 int anslen)             /* size of answer */
 282 {
 283         if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
 284                 RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
 285                 return (-1);
 286         }
 287
 288         return (res_nquerydomain(&_res, name, domain,
 289                                  class, type,
 290                                  answer, anslen));
 291 }
 292
 293 const char *
 294 hostalias(const char *name) {
 295         static char abuf[MAXDNAME];
 296
 297         return (res_hostalias(&_res, name, abuf, sizeof abuf));
 298 }
 299
 300 #ifdef ultrix
 301 int
 302 local_hostname_length(const char *hostname) {
 303         int len_host, len_domain;
 304
 305         if (!*_res.defdname)
 306                 res_init();
 307         len_host = strlen(hostname);
 308         len_domain = strlen(_res.defdname);
 309         if (len_host > len_domain &&
 310             !strcasecmp(hostname + len_host - len_domain, _res.defdname) &&
 311             hostname[len_host - len_domain - 1] == '.')
 312                 return (len_host - len_domain - 1);
 313         return (0);
 314 }
 315 #endif /*ultrix*/
 316
 317 #endif
 318 \f
 319
 320 #include <shlib-compat.h>
 321
 322 #if SHLIB_COMPAT(libresolv, GLIBC_2_0, GLIBC_2_2)
 323 # undef res_mkquery
 324 # undef res_query
 325 # undef res_querydomain
 326 # undef res_search
 327 weak_alias (__res_mkquery, res_mkquery);
 328 weak_alias (__res_query, res_query);
 329 weak_alias (__res_querydomain, res_querydomain);
 330 weak_alias (__res_search, res_search);
 331 #endif