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authorFlorian Weimer <fweimer@redhat.com>2017-06-30 21:10:23 +0200
committerFlorian Weimer <fweimer@redhat.com>2017-07-03 20:52:59 +0200
commit352f4ff9a268b81ef5d4b2413f582565806e4790 (patch)
treefb27056dfdeafe43c021f6127c9544c016e78019 /nss/getXXbyYY_r.c
parent4e45d83c92dbb5b8dc20654f32395108d18cf739 (diff)
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resolv: Introduce struct resolv_context [BZ #21668]
struct resolv_context objects provide a temporary resolver context which does not change during a name lookup operation. Only when the outmost context is created, the stub resolver configuration is verified to be current (at present, only against previous res_init calls). Subsequent attempts to obtain the context will reuse the result of the initial verification operation. struct resolv_context can also be extended in the future to store data which needs to be deallocated during thread cancellation.
Diffstat (limited to 'nss/getXXbyYY_r.c')
-rw-r--r--nss/getXXbyYY_r.c34
1 files changed, 20 insertions, 14 deletions
diff --git a/nss/getXXbyYY_r.c b/nss/getXXbyYY_r.c
index 7cab825cf0..6c547ea1ca 100644
--- a/nss/getXXbyYY_r.c
+++ b/nss/getXXbyYY_r.c
@@ -26,7 +26,7 @@
# include <nscd/nscd_proto.h>
#endif
#ifdef NEED__RES
-# include <resolv.h>
+# include <resolv/resolv_context.h>
#endif
/*******************************************************************\
|* Here we assume several symbols to be defined: *|
@@ -53,8 +53,7 @@
|* NEED_H_ERRNO - an extra parameter will be passed to point to *|
|* the global `h_errno' variable. *|
|* *|
-|* NEED__RES - the global _res variable might be used so we *|
-|* will have to initialize it if necessary *|
+|* NEED__RES - obtain a struct resolv_context resolver context *|
|* *|
|* PREPROCESS - code run before anything else *|
|* *|
@@ -213,6 +212,18 @@ INTERNAL (REENTRANT_NAME) (ADD_PARAMS, LOOKUP_TYPE *resbuf, char *buffer,
bool any_service = false;
#endif
+#ifdef NEED__RES
+ /* The HANDLE_DIGITS_DOTS case below already needs the resolver
+ configuration, so this has to happen early. */
+ struct resolv_context *res_ctx = __resolv_context_get ();
+ if (res_ctx == NULL)
+ {
+ *h_errnop = NETDB_INTERNAL;
+ *result = NULL;
+ return errno;
+ }
+#endif /* NEED__RES */
+
#ifdef PREPROCESS
PREPROCESS;
#endif
@@ -260,17 +271,6 @@ INTERNAL (REENTRANT_NAME) (ADD_PARAMS, LOOKUP_TYPE *resbuf, char *buffer,
}
else
{
-#ifdef NEED__RES
- /* The resolver code will really be used so we have to
- initialize it. */
- if (__res_maybe_init (&_res, 0) == -1)
- {
- *h_errnop = NETDB_INTERNAL;
- *result = NULL;
- return errno;
- }
-#endif /* need _res */
-
void *tmp_ptr = fct.l;
#ifdef PTR_MANGLE
PTR_MANGLE (tmp_ptr);
@@ -399,6 +399,12 @@ done:
POSTPROCESS;
#endif
+#ifdef NEED__RES
+ /* This has to happen late because the POSTPROCESS stage above might
+ need the resolver context. */
+ __resolv_context_put (res_ctx);
+#endif /* NEED__RES */
+
int res;
if (status == NSS_STATUS_SUCCESS || status == NSS_STATUS_NOTFOUND)
res = 0;