4 files changed, 104 insertions, 1 deletions
diff --git a/avahi-client/Makefile.am b/avahi-client/Makefile.am
index 3a03392..f45f58d 100644
--- a/avahi-client/Makefile.am
+++ b/avahi-client/Makefile.am
@@ -35,7 +35,8 @@ noinst_PROGRAMS = \
 	client-test \
 	srv-test \
 	xdg-config-test \
-	rr-test
+	rr-test \
+	check-nss-test
 
 endif
 
@@ -48,6 +49,7 @@ libavahi_client_la_SOURCES = \
 	resolver.c \
 	publish.h lookup.h \
 	xdg-config.c xdg-config.h \
+	check-nss.c \
 	../avahi-common/dbus.c ../avahi-common/dbus.h \
 	../avahi-common/dbus-watch-glue.c ../avahi-common/dbus-watch-glue.h
 
@@ -71,4 +73,13 @@ xdg_config_test_SOURCES = xdg-config-test.c xdg-config.c xdg-config.h
 xdg_config_test_CFLAGS = $(AM_CFLAGS) 
 xdg_config_test_LDADD = $(AM_LDADD)
 
+check_nss_test_SOURCES = check-nss.c check-nss-test.c client.h
+check_nss_test_CFLAGS = $(AM_CFLAGS) 
+check_nss_test_LDADD = $(AM_LDADD)
+
+if HAVE_DLOPEN
+check_nss_test_LDADD += -ldl
+libavahi_client_la_LIBADD += -ldl
+endif
+
 endif
diff --git a/avahi-client/check-nss-test.c b/avahi-client/check-nss-test.c
new file mode 100644
index 0000000..172b4fa
--- /dev/null
+++ b/avahi-client/check-nss-test.c
@@ -0,0 +1,32 @@
+/* $Id$ */
+
+/***
+  This file is part of avahi.
+ 
+  avahi is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as
+  published by the Free Software Foundation; either version 2.1 of the
+  License, or (at your option) any later version.
+ 
+  avahi is distributed in the hope that it will be useful, but WITHOUT
+  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+  or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General
+  Public License for more details.
+ 
+  You should have received a copy of the GNU Lesser General Public
+  License along with avahi; if not, write to the Free Software
+  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
+  USA.
+***/
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <stdio.h>
+
+#include <avahi-client/client.h>
+
+int main(AVAHI_GCC_UNUSED int argc, AVAHI_GCC_UNUSED char *argv[]) {
+    printf("NSS Support available: %s\n", avahi_nss_support() ? "yes" : "no");
+}
diff --git a/avahi-client/check-nss.c b/avahi-client/check-nss.c
new file mode 100644
index 0000000..0a933fa
--- /dev/null
+++ b/avahi-client/check-nss.c
@@ -0,0 +1,57 @@
+/* $Id$ */
+
+/***
+  This file is part of avahi.
+ 
+  avahi is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as
+  published by the Free Software Foundation; either version 2.1 of the
+  License, or (at your option) any later version.
+ 
+  avahi is distributed in the hope that it will be useful, but WITHOUT
+  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+  or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General
+  Public License for more details.
+ 
+  You should have received a copy of the GNU Lesser General Public
+  License along with avahi; if not, write to the Free Software
+  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
+  USA.
+***/
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#ifdef HAVE_DLOPEN
+#include <dlfcn.h>
+#endif
+#include <stdlib.h>
+
+#include "client.h"
+
+int avahi_nss_support(void) {
+    int b = 0;
+    
+#ifdef HAVE_DLOPEN
+    static const char * const libs[] = {
+        "libnss_mdns.so.2",
+        "libnss_mdns4.so.2",
+        "libnss_mdns6.so.2",
+        NULL };
+    
+    const char * const *l;
+    
+    for (l = libs; *l; l++) {
+        void *dl;
+        
+        if ((dl = dlopen(*l, RTLD_LAZY))) {
+            b = 1;
+            dlclose(dl);
+            break;
+        }
+    }
+#endif
+
+    return b;
+}
diff --git a/avahi-client/client.h b/avahi-client/client.h
index 9d73778..098d568 100644
--- a/avahi-client/client.h
+++ b/avahi-client/client.h
@@ -85,6 +85,9 @@ int avahi_client_errno (AvahiClient*);
 /** Return the local service cookie. returns AVAHI_SERVICE_COOKIE_INVALID on failure. */
 uint32_t avahi_client_get_local_service_cookie(AvahiClient *client);
 
+/** Return 1 if gethostbyname() supports mDNS lookups, 0 otherwise */
+int avahi_nss_support(void);
+
 AVAHI_C_DECL_END
 
 #endif