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/*
* 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.
*/
#include <sys/types.h>
#include <netinet/in.h>
#include <arpa/nameser.h>
#include <resolv.h>
#undef _res
#include <tls.h>
#if USE_TLS && HAVE___THREAD
/* With __thread support, this per-thread variable is used in all cases. */
__thread struct __res_state _res;
extern __thread struct __res_state __libc_res __attribute__ ((alias ("_res")))
attribute_hidden;
# define _res __libc_res
#else
/* The resolver state for use by single-threaded programs.
This differs from a plain uninitialized definition in that it doesn't
create a common definition, but a plain symbol that resides in .bss,
which can have an alias. */
struct __res_state _res __attribute__ ((section (".bss")));
/* This alias is needed by libpthread. */
strong_alias (_res, __libc_res)
/* We declare this with compat_symbol so that it's not
visible at link time. Programs must use the accessor functions. */
# if defined HAVE_ELF && defined SHARED && defined DO_VERSIONING
# include <shlib-compat.h>
compat_symbol (libc, _res, _res, GLIBC_2_0);
# endif
#endif
/* This function is used to access the resolver state in
single-threaded programs. */
struct __res_state *
weak_const_function
__res_state (void)
{
return &_res;
}
/* The following bit is copied from res_data.c (where it is #ifdef'ed
out) since res_init() should go into libc.so but the rest of that
file should 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));
}
#include <shlib-compat.h>
#if SHLIB_COMPAT(libc, GLIBC_2_0, GLIBC_2_2)
# undef res_init
strong_alias (__res_init, __res_init_weak);
weak_extern (__res_init_weak);
compat_symbol (libc, __res_init_weak, res_init, GLIBC_2_0);
#endif
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