nsswitch: protect access to wb_global_ctx by a mutex

This change will make libwbclient thread safe for all API calls not using a
context. Especially there are no more conflicts with threads using nsswitch
and libwbclient in parallel.

Signed-off-by: Ralph Wuerthner <ralph.wuerthner@de.ibm.com>
Reviewed-by: Volker Lendecke <vl@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>

diff --git a/nsswitch/wb_common.c b/nsswitch/wb_common.c
index 9ba74c35a6d47ec39068141ef1badf72f6d32b8b..59370aa5bbc211b30ffd900b26ad7fdc2ecaa719 100644 (file)
--- a/nsswitch/wb_common.c
+++ b/nsswitch/wb_common.c
@@ -27,6 +27,10 @@
 #include "system/select.h"
 #include "winbind_client.h"
 
+#if HAVE_PTHREAD_H
+#include <pthread.h>
+#endif
+
 /* Global context */
 
 struct winbindd_context {
@@ -35,6 +39,10 @@ struct winbindd_context {
        pid_t our_pid;          /* calling process pid */
 };
 
+#if HAVE_PTHREAD
+static pthread_mutex_t wb_global_ctx_mutex = PTHREAD_MUTEX_INITIALIZER;
+#endif
+
 static struct winbindd_context *get_wb_global_ctx(void)
 {
        static struct winbindd_context wb_global_ctx = {
@@ -43,12 +51,17 @@ static struct winbindd_context *get_wb_global_ctx(void)
                .our_pid = 0
        };
 
+#if HAVE_PTHREAD
+       pthread_mutex_lock(&wb_global_ctx_mutex);
+#endif
        return &wb_global_ctx;
 }
 
 static void put_wb_global_ctx(void)
 {
-       /* noop for now */
+#if HAVE_PTHREAD
+       pthread_mutex_unlock(&wb_global_ctx_mutex);
+#endif
        return;
 }