diff options
Diffstat (limited to 'REORG.TODO/resolv/res_libc.c')
| -rw-r--r-- | REORG.TODO/resolv/res_libc.c | 144 |
1 files changed, 144 insertions, 0 deletions
diff --git a/REORG.TODO/resolv/res_libc.c b/REORG.TODO/resolv/res_libc.c new file mode 100644 index 0000000000..c8f158d94c --- /dev/null +++ b/REORG.TODO/resolv/res_libc.c @@ -0,0 +1,144 @@ +/* + * 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. + */ + +/* This file contains the definitions related to res_init which are + linked into libc instead of libresolv. */ + +#include <atomic.h> +#include <limits.h> +#include <sys/types.h> +#include <netinet/in.h> +#include <arpa/nameser.h> +#include <resolv.h> +#include <libc-lock.h> + +extern unsigned long long int __res_initstamp attribute_hidden; +/* We have atomic increment operations on 64-bit platforms. */ +#if __WORDSIZE == 64 +# define atomicinclock(lock) (void) 0 +# define atomicincunlock(lock) (void) 0 +# define atomicinc(var) catomic_increment (&(var)) +#else +__libc_lock_define_initialized (static, lock); +# define atomicinclock(lock) __libc_lock_lock (lock) +# define atomicincunlock(lock) __libc_lock_unlock (lock) +# define atomicinc(var) ++var +#endif + +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 = RES_DFLRETRY; + if (!(_res.options & RES_INIT)) + _res.options = RES_DEFAULT; + else if (_res.nscount > 0) + __res_iclose (&_res, true); /* Close any VC sockets. */ + + /* + * 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(); + + atomicinclock (lock); + /* Request all threads to re-initialize their resolver states, + resolv.conf might have changed. */ + atomicinc (__res_initstamp); + atomicincunlock (lock); + + return (__res_vinit(&_res, 1)); +} + +/* Initialize resp if RES_INIT is not yet set or if res_init in some other + thread requested re-initializing. */ +int +__res_maybe_init (res_state resp, int preinit) +{ + if (resp->options & RES_INIT) { + if (__res_initstamp != resp->_u._ext.initstamp) { + if (resp->nscount > 0) + __res_iclose (resp, true); + return __res_vinit (resp, 1); + } + return 0; + } else if (preinit) { + if (!resp->retrans) + resp->retrans = RES_TIMEOUT; + if (!resp->retry) + resp->retry = RES_DFLRETRY; + resp->options = RES_DEFAULT; + if (!resp->id) + resp->id = res_randomid (); + return __res_vinit (resp, 1); + } else + return __res_ninit (resp); +} +libc_hidden_def (__res_maybe_init) + +/* This needs to be after the use of _res in res_init, above. */ +#undef _res + +/* 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__ ((nocommon)); + +#undef __resp +__thread struct __res_state *__resp = &_res; +extern __thread struct __res_state *__libc_resp + __attribute__ ((alias ("__resp"))) attribute_hidden; + +#include <shlib-compat.h> + +/* We declare this with compat_symbol so that it's not + visible at link time. Programs must use the accessor functions. */ +#ifdef SHARED +compat_symbol (libc, _res, _res, GLIBC_2_0); +#endif + +#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 |