qemu-ga: check if utmpx.h is available on the system

Commit 161a56a9065 added command guest-get-users and requires the
utmpx.h (defined by POSIX) to work. It is however not always available
(e.g. on OpenBSD) therefor a check for its existence is necessary.

Signed-off-by: Tomáš Golembiovský <tgolembi@redhat.com>
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>

2 files changed, 35 insertions, 1 deletions

diff --git a/configure b/configure
index a3f0522e8f..e8798cec79 100755
--- a/configure
+++ b/configure
@@ -4915,6 +4915,21 @@ if compile_prog "" "" ; then
 fi
 
 ##########################################
+# check for utmpx.h, it is missing e.g. on OpenBSD
+
+have_utmpx=no
+cat > $TMPC << EOF
+#include <utmpx.h>
+struct utmpx user_info;
+int main(void) {
+    return 0;
+}
+EOF
+if compile_prog "" "" ; then
+    have_utmpx=yes
+fi
+
+##########################################
 # End of CC checks
 # After here, no more $cc or $ld runs
 
@@ -5959,6 +5974,10 @@ if test "$have_static_assert" = "yes" ; then
   echo "CONFIG_STATIC_ASSERT=y" >> $config_host_mak
 fi
 
+if test "$have_utmpx" = "yes" ; then
+  echo "HAVE_UTMPX=y" >> $config_host_mak
+fi
+
 # Hold two types of flag:
 #   CONFIG_THREAD_SETNAME_BYTHREAD  - we've got a way of setting the name on
 #                                     a thread we have a handle to
diff --git a/qga/commands-posix.c b/qga/commands-posix.c
index d8e412275e..e7a047e4c2 100644
--- a/qga/commands-posix.c
+++ b/qga/commands-posix.c
@@ -15,7 +15,6 @@
 #include <sys/ioctl.h>
 #include <sys/wait.h>
 #include <dirent.h>
-#include <utmpx.h>
 #include "qga/guest-agent-core.h"
 #include "qga-qmp-commands.h"
 #include "qapi/qmp/qerror.h"
@@ -25,6 +24,10 @@
 #include "qemu/base64.h"
 #include "qemu/cutils.h"
 
+#ifdef HAVE_UTMPX
+#include <utmpx.h>
+#endif
+
 #ifndef CONFIG_HAS_ENVIRON
 #ifdef __APPLE__
 #include <crt_externs.h>
@@ -2519,6 +2522,8 @@ void ga_command_state_init(GAState *s, GACommandState *cs)
 #endif
 }
 
+#ifdef HAVE_UTMPX
+
 #define QGA_MICRO_SECOND_TO_SECOND 1000000
 
 static double ga_get_login_time(struct utmpx *user_info)
@@ -2577,3 +2582,13 @@ GuestUserList *qmp_guest_get_users(Error **err)
     g_hash_table_destroy(cache);
     return head;
 }
+
+#else
+
+GuestUserList *qmp_guest_get_users(Error **errp)
+{
+    error_setg(errp, QERR_UNSUPPORTED);
+    return NULL;
+}
+
+#endif