From afea26ad7d406d8b6c95d2642cb5a1d807b87546 Mon Sep 17 00:00:00 2001
From: Lennart Poettering <lennart@poettering.net>
Date: Wed, 11 Aug 2010 23:31:07 +0200
Subject: [PATCH] main: disable nscd properly, if possible

---
 configure.ac  |  1 +
 fixme         |  2 --
 src/main.c    |  6 +-----
 src/missing.h |  8 --------
 src/util.c    | 19 +++++++++++++++++++
 src/util.h    |  2 ++
 6 files changed, 23 insertions(+), 15 deletions(-)

diff --git a/configure.ac b/configure.ac
index 72218e4df..f8a4247e6 100644
--- a/configure.ac
+++ b/configure.ac
@@ -91,6 +91,7 @@ LT_PREREQ(2.2)
 LT_INIT
 
 AC_SEARCH_LIBS([clock_gettime], [rt], [], [AC_MSG_ERROR([*** POSIX RT library not found])])
+AC_SEARCH_LIBS([dlsym], [dl], [], [AC_MSG_ERROR([*** Dynamic linking loader library not found])])
 AC_SEARCH_LIBS([cap_init], [cap], [], [AC_MSG_ERROR([*** POSIX caps library not found])])
 AC_CHECK_HEADERS([sys/capability.h], [], [AC_MSG_ERROR([*** POSIX caps headers not found])])
 
diff --git a/fixme b/fixme
index 32bd40fa4..6d0f5b2ed 100644
--- a/fixme
+++ b/fixme
@@ -79,8 +79,6 @@
 
 * plymouth different shut down msgs
 
-* fix nscd disable
-
 External:
 
 * sysv functions should color when stdout is tty, not stdin
diff --git a/src/main.c b/src/main.c
index 72015bc54..2e17f9b6f 100644
--- a/src/main.c
+++ b/src/main.c
@@ -994,11 +994,7 @@ int main(int argc, char *argv[]) {
 
                 /* Disable nscd, to avoid deadlocks when systemd uses
                  * NSS and the nscd socket is maintained by us. */
-                /* if (nss_disable_nscd) { */
-                /*         log_debug("Disabling nscd"); */
-                /*         nss_disable_nscd(); */
-                /* } else */
-                /*         log_debug("Hmm, can't disable nscd."); */
+                nss_disable_nscd();
 
                 if (!serialization) {
                         if (arg_show_status)
diff --git a/src/missing.h b/src/missing.h
index d6114cc2b..f40d36ebc 100644
--- a/src/missing.h
+++ b/src/missing.h
@@ -55,14 +55,6 @@ static inline int pivot_root(const char *new_root, const char *put_old) {
         return syscall(SYS_pivot_root, new_root, put_old);
 }
 
-/* This is an internal glibc function call. We are not supposed to
- * call this, because we are not nscd. However sometimes we feel
- * really dangerous and do it nonetheless. Muahahah! But at least we
- * protect this with a weak ref just in case glibc takes this away
- * from us. */
-
-/* static void nss_disable_nscd(void) _weakref_(__nss_disable_nscd); */
-
 #ifndef AUDIT_SERVICE_START
 #define AUDIT_SERVICE_START     1130    /* Service (daemon) start */
 #endif
diff --git a/src/util.c b/src/util.c
index c4ff5aa57..c2ef34dd4 100644
--- a/src/util.c
+++ b/src/util.c
@@ -48,6 +48,7 @@
 #include <pwd.h>
 #include <netinet/ip.h>
 #include <linux/kd.h>
+#include <dlfcn.h>
 
 #include "macro.h"
 #include "util.h"
@@ -2979,6 +2980,24 @@ char *ellipsize(const char *s, unsigned length, unsigned percent) {
         return r;
 }
 
+void nss_disable_nscd(void) {
+
+        void (*func)(void);
+
+        /* This is an internal glibc function call. We are not
+         * supposed to call this, because we are not nscd. However
+         * sometimes we feel really dangerous and do it
+         * nonetheless. Muahahah! But at least we protect this with a
+         * dlsym() just in case glibc takes this away from us. */
+
+        if ((func = dlsym(RTLD_DEFAULT, "__nss_disable_nscd"))) {
+                log_debug("Disabling nscd.");
+                func();
+        } else
+                log_debug("Cannot disable nscd.");
+}
+
+
 static const char *const ioprio_class_table[] = {
         [IOPRIO_CLASS_NONE] = "none",
         [IOPRIO_CLASS_RT] = "realtime",
diff --git a/src/util.h b/src/util.h
index 21f47dc16..66ebb46db 100644
--- a/src/util.h
+++ b/src/util.h
@@ -336,6 +336,8 @@ int running_in_chroot(void);
 
 char *ellipsize(const char *s, unsigned length, unsigned percent);
 
+void nss_disable_nscd(void);
+
 const char *ioprio_class_to_string(int i);
 int ioprio_class_from_string(const char *s);
 
-- 
2.30.2