mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-05 21:00:05 +00:00
e361e438a1
* resolv/res_libc.c [USE___THREAD] (_res): Don't need the initializer anymore now that res_thread_freeres is more careful.
103 lines
3.7 KiB
C
103 lines
3.7 KiB
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.
|
||
*/
|
||
|
||
#include <sys/types.h>
|
||
#include <netinet/in.h>
|
||
#include <arpa/nameser.h>
|
||
#include <resolv.h>
|
||
|
||
|
||
/* 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));
|
||
}
|
||
|
||
/* This needs to be after the use of _res in res_init, above. */
|
||
#undef _res
|
||
|
||
#include <tls.h>
|
||
|
||
#if USE___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 plain `struct __res_state _res;' 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")));
|
||
|
||
/* 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
|
||
|
||
#include <shlib-compat.h>
|
||
|
||
#if SHLIB_COMPAT(libc, GLIBC_2_0, GLIBC_2_2)
|
||
# undef res_init
|
||
extern int __res_init_weak (void);
|
||
weak_extern (__res_init_weak);
|
||
strong_alias (__res_init, __res_init_weak);
|
||
compat_symbol (libc, __res_init_weak, res_init, GLIBC_2_0);
|
||
#endif
|