uClibc: Fix threaded use of res_ functions.

This patch moves res_init() back above #undef _res. It fixes dns resolving issue in OpenWrt
(uClibc related - OpenWrt ticket #11929). It is a backport from uClibc master.

Further details are there:
http://git.uclibc.org/uClibc/commit/libc/inet/resolv.c?id=20b69920b299585265eb100d0b67e1097ccb1092

Signed-off-by: Jiri Slachta <slachta@cesnet.cz>

SVN-Revision: 39177
This commit is contained in:
Felix Fietkau 2013-12-28 15:05:56 +00:00
parent 5607a13aa1
commit 8cabffaa3b

View File

@ -0,0 +1,126 @@
--- a/libc/inet/resolv.c
+++ b/libc/inet/resolv.c
@@ -3536,6 +3536,61 @@
return 0;
}
+static unsigned int
+res_randomid(void)
+{
+ return 0xffff & getpid();
+}
+
+/* Our res_init never fails (always returns 0) */
+int
+res_init(void)
+{
+ /*
+ * 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).
+ */
+
+ __UCLIBC_MUTEX_LOCK(__resolv_lock);
+
+ 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();
+
+ __UCLIBC_MUTEX_UNLOCK(__resolv_lock);
+
+ __res_vinit(&_res, 1);
+ __res_sync = res_sync_func;
+
+ return 0;
+}
+libc_hidden_def(res_init)
+
static void
__res_iclose(void)
{
@@ -3608,61 +3663,6 @@
# endif
#endif /* !__UCLIBC_HAS_THREADS__ */
-static unsigned int
-res_randomid(void)
-{
- return 0xffff & getpid();
-}
-
-/* Our res_init never fails (always returns 0) */
-int
-res_init(void)
-{
- /*
- * 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).
- */
-
- __UCLIBC_MUTEX_LOCK(__resolv_lock);
-
- 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();
-
- __UCLIBC_MUTEX_UNLOCK(__resolv_lock);
-
- __res_vinit(&_res, 1);
- __res_sync = res_sync_func;
-
- return 0;
-}
-libc_hidden_def(res_init)
-
/*
* Set up default settings. If the configuration file exist, the values
* there will have precedence. Otherwise, the server address is set to