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res_data.c

/*
 * Copyright (c) 1995-1999 by Internet Software Consortium.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
 * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
 * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
 * SOFTWARE.
 */

#if defined(LIBC_SCCS) && !defined(lint)
static const char rcsid[] = "$BINDId: res_data.c,v 8.17 1999/10/13 17:11:31 vixie Exp $";
#endif /* LIBC_SCCS and not lint */

#include <sys/types.h>
#include <sys/param.h>
#include <sys/socket.h>
#include <sys/time.h>

#include <netinet/in.h>
#include <arpa/inet.h>
#include <arpa/nameser.h>

#include <ctype.h>
#include <netdb.h>
#include <resolv.h>
#ifdef BIND_UPDATE
#include <res_update.h>
#endif
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

const char *_res_opcodes[] = {
      "QUERY",
      "IQUERY",
      "CQUERYM",
      "CQUERYU",  /* experimental */
      "NOTIFY",   /* experimental */
      "UPDATE",
      "6",
      "7",
      "8",
      "9",
      "10",
      "11",
      "12",
      "13",
      "ZONEINIT",
      "ZONEREF",
};

#ifdef BIND_UPDATE
const char *_res_sectioncodes[] = {
      "ZONE",
      "PREREQUISITES",
      "UPDATE",
      "ADDITIONAL",
};
#endif

#ifndef __BIND_NOSTATIC
#ifdef _LIBC
/* The definition has been moved to res_libc.c.  */
#else
#undef _res
struct __res_state _res
# if defined(__BIND_RES_TEXT)
      = { RES_TIMEOUT, }      /* Motorola, et al. */
# endif
        ;
#endif

/* Proto. */
#ifndef _LIBC
int  res_ourserver_p(const res_state, const struct sockaddr_in *);
void res_pquery(const res_state, const u_char *, int, FILE *);
#endif

#ifndef _LIBC
/* Moved to res_libc.c since res_init() should go into libc.so but the
   rest of this file not.  */
int
res_init(void) {
      extern int __res_vinit(res_state, int);

      /*
       * These three fields used to be statically initialized.  This made
       * it hard to use this code in a shared library.  It is necessary,
       * now that we're doing dynamic initialization here, that we preserve
       * the old semantics: if an application modifies one of these three
       * fields of _res before res_init() is called, res_init() will not
       * alter them.  Of course, if an application is setting them to
       * _zero_ before calling res_init(), hoping to override what used
       * to be the static default, we can't detect it and unexpected results
       * will follow.  Zero for any of these fields would make no sense,
       * so one can safely assume that the applications were already getting
       * unexpected results.
       *
       * _res.options is tricky since some apps were known to diddle the bits
       * before res_init() was first called. We can't replicate that semantic
       * with dynamic initialization (they may have turned bits off that are
       * set in RES_DEFAULT).  Our solution is to declare such applications
       * "broken".  They could fool us by setting RES_INIT but none do (yet).
       */
      if (!_res.retrans)
            _res.retrans = RES_TIMEOUT;
      if (!_res.retry)
            _res.retry = 4;
      if (!(_res.options & RES_INIT))
            _res.options = RES_DEFAULT;

      /*
       * This one used to initialize implicitly to zero, so unless the app
       * has set it to something in particular, we can randomize it now.
       */
      if (!_res.id)
            _res.id = res_randomid();

      return (__res_vinit(&_res, 1));
}
#endif

void
p_query(const u_char *msg) {
      fp_query(msg, stdout);
}

void
fp_query(const u_char *msg, FILE *file) {
      fp_nquery(msg, PACKETSZ, file);
}

void
fp_nquery(const u_char *msg, int len, FILE *file) {
      if ((_res.options & RES_INIT) == 0 && __res_ninit(&_res) == -1)
            return;

      res_pquery(&_res, msg, len, file);
}

int
res_mkquery(int op,                 /* opcode of query */
          const char *dname,        /* domain name */
          int class, int type,      /* class and type of query */
          const u_char *data,       /* resource record data */
          int datalen,        /* length of data */
          const u_char *newrr_in,   /* new rr for modify or append */
          u_char *buf,        /* buffer to put query */
          int buflen)               /* size of buffer */
{
      if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
            RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
            return (-1);
      }
      return (res_nmkquery(&_res, op, dname, class, type,
                       data, datalen,
                       newrr_in, buf, buflen));
}

#ifdef BIND_UPDATE
int
res_mkupdate(ns_updrec *rrecp_in, u_char *buf, int buflen) {
      if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
            RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
            return (-1);
      }

      return (res_nmkupdate(&_res, rrecp_in, buf, buflen));
}
#endif

int
res_query(const char *name,   /* domain name */
        int class, int type,  /* class and type of query */
        u_char *answer, /* buffer to put answer */
        int anslen)           /* size of answer buffer */
{
      if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
            RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
            return (-1);
      }
      return (res_nquery(&_res, name, class, type, answer, anslen));
}

void
res_send_setqhook(res_send_qhook hook) {
      _res.qhook = hook;
}

void
res_send_setrhook(res_send_rhook hook) {
      _res.rhook = hook;
}

int
res_isourserver(const struct sockaddr_in *inp) {
      return (res_ourserver_p(&_res, (const struct sockaddr_in6 *) inp));
}

int
res_send(const u_char *buf, int buflen, u_char *ans, int anssiz) {
      if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
            /* errno should have been set by res_init() in this case. */
            return (-1);
      }

      return (res_nsend(&_res, buf, buflen, ans, anssiz));
}

#ifndef _LIBC
int
res_sendsigned(const u_char *buf, int buflen, ns_tsig_key *key,
             u_char *ans, int anssiz)
{
      if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
            /* errno should have been set by res_init() in this case. */
            return (-1);
      }

      return (res_nsendsigned(&_res, buf, buflen, key, ans, anssiz));
}
#endif

void
res_close(void) {
#ifdef _LIBC
      /*
       * Some stupid programs out there call res_close() before res_init().
       * Since _res._vcsock isn't explicitly initialized, these means that
       * we could do a close(0), which might lead to some security problems.
       * Therefore we check if res_init() was called before by looking at
       * the RES_INIT bit in _res.options.  If it hasn't been set we bail out
       * early.  */
      if ((_res.options & RES_INIT) == 0)
        return;
#endif
      res_nclose(&_res);
}

#ifdef BIND_UPDATE
int
res_update(ns_updrec *rrecp_in) {
      if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
            RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
            return (-1);
      }

      return (res_nupdate(&_res, rrecp_in, NULL));
}
#endif

int
res_search(const char *name,  /* domain name */
         int class, int type, /* class and type of query */
         u_char *answer,      /* buffer to put answer */
         int anslen)          /* size of answer */
{
      if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
            RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
            return (-1);
      }

      return (res_nsearch(&_res, name, class, type, answer, anslen));
}

int
res_querydomain(const char *name,
            const char *domain,
            int class, int type,    /* class and type of query */
            u_char *answer,         /* buffer to put answer */
            int anslen)       /* size of answer */
{
      if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
            RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
            return (-1);
      }

      return (res_nquerydomain(&_res, name, domain,
                         class, type,
                         answer, anslen));
}

const char *
hostalias(const char *name) {
      static char abuf[MAXDNAME];

      return (res_hostalias(&_res, name, abuf, sizeof abuf));
}

#ifdef ultrix
int
local_hostname_length(const char *hostname) {
      int len_host, len_domain;

      if (!*_res.defdname)
            res_init();
      len_host = strlen(hostname);
      len_domain = strlen(_res.defdname);
      if (len_host > len_domain &&
          !strcasecmp(hostname + len_host - len_domain, _res.defdname) &&
          hostname[len_host - len_domain - 1] == '.')
            return (len_host - len_domain - 1);
      return (0);
}
#endif /*ultrix*/

#endif


#include <shlib-compat.h>

#if SHLIB_COMPAT(libresolv, GLIBC_2_0, GLIBC_2_2)
# undef res_mkquery
# undef res_query
# undef res_querydomain
# undef res_search
weak_alias (__res_mkquery, res_mkquery);
weak_alias (__res_query, res_query);
weak_alias (__res_querydomain, res_querydomain);
weak_alias (__res_search, res_search);
#endif

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