Allow some utmpx fields to be optional

POSIX.1 doesn't define ut_host in struct utmpx. Also, Linux has support
for an exit status value in ut_exit. This commit adds conditional code
for both ut_host and ut_exit to maximise portability.

configure.ac

@@ -520,6 +520,10 @@ AC_CHECK_HEADER([X11/extensions/Xrandr.h], [],
 if test "x$enable_utmp" = "xyes"
 then
     AC_CHECK_HEADERS(utmp.h utmpx.h)
+
+    # Test for non-standard extensions in struct utmpx
+    AXRDP_CHECK_UTMPX_MEMBER_EXISTS([ut_host], [HAVE_UTMPX_UT_HOST])
+    AXRDP_CHECK_UTMPX_MEMBER_EXISTS([ut_exit], [HAVE_UTMPX_UT_EXIT])
 fi
 
 CFLAGS="$save_CFLAGS"
@@ -640,6 +644,11 @@ echo "  vsock                   $enable_vsock"
 echo "  auth mechanism          $auth_mech"
 echo "  rdpsndaudin             $enable_rdpsndaudin"
 echo "  utmp support            $enable_utmp"
+if test x$enable_utmp = xyes; then
+    echo "    utmpx.ut_host         $ac_cv_utmpx_has_ut_host"
+    echo "    utmpx.ut_exit         $ac_cv_utmpx_has_ut_exit"
+fi
+
 echo
 echo "  with imlib2             $use_imlib2"
 echo "  with freetype2          $use_freetype2"

m4/axrdp.m4

@@ -0,0 +1,43 @@
+# SYNOPSIS
+#
+#   AXRDP_CHECK_UTMPX_MEMBER_EXISTS(MEMBER, COMPILE-DEFINE)
+#
+# EXAMPLE
+#
+# CHECK_UTMPX_MEMBER_EXISTS([ut_exit], [HAVE_UTMPX_UT_EXIT])
+#
+# DESCRIPTION
+#
+#   If the member MEMBER exists in the utmpx struct, the COMPILE-DEFINE
+#   is set for the C compiler.
+#
+#   The shell variable 'ac_cv_utmpx_has_$MEMBER' is set to 'yes' or 'no'
+#   and cached
+#
+AC_DEFUN([AXRDP_CHECK_UTMPX_MEMBER_EXISTS],
+[
+  AS_VAR_PUSHDEF([x_var], [ac_cv_utmpx_has_$1])
+  AS_VAR_PUSHDEF([x_define], [$2])
+  AC_CACHE_CHECK(
+      [for $1 in struct utmpx],
+      [x_var],
+      [AC_COMPILE_IFELSE(
+         [AC_LANG_SOURCE([[
+#           include <utmpx.h>
+#           include <stddef.h>
+            int main()
+            {
+                return offsetof(struct utmpx,$1);
+            }]])],
+         [AS_VAR_SET([x_var], [yes])],
+         [AS_VAR_SET([x_var], [no])])]
+  )
+  AS_VAR_IF(
+    [x_var],
+    [yes],
+    [AC_DEFINE([x_define], [1], [Define if '$1' is in struct utmpx.])])
+  AS_VAR_POPDEF([x_var])
+  AS_VAR_POPDEF([x_define])
+])
+
+

sesman/sesexec/session.c

@@ -891,7 +891,7 @@ session_process_child_exit(struct session_data *sd,
                 sd->win_mgr, sd->params.display, wm_wait_time);
         }
 
-        utmp_logout(sd->win_mgr, sd->params.display);
+        utmp_logout(sd->win_mgr, sd->params.display, e);
         sd->win_mgr = -1;
 
         if (sd->x_server > 0)

sesman/sesexec/sessionrecord.c

@@ -48,10 +48,6 @@ enum add_xtmp_mode
 
 #ifdef USE_UTMP
 
-#include <pwd.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
 #include <sys/time.h>
 #include <unistd.h>
 
@@ -80,7 +76,7 @@ typedef struct utmp _utmp;
 
 static void
 add_xtmp_entry(int pid, int display, const struct login_info *login_info,
-               enum add_xtmp_mode mode)
+               enum add_xtmp_mode mode, const struct proc_exit_status *e)
 {
 #if USE_UTMP
     char idbuff[16];
@@ -102,9 +98,22 @@ add_xtmp_entry(int pid, int display, const struct login_info *login_info,
     g_strncpy(ut.ut_id, idbuff, sizeof(ut.ut_id));
     if (login_info != NULL)
     {
-        g_strncpy(ut.ut_user, login_info->username , sizeof(ut.ut_user));
+        g_strncpy(ut.ut_user, login_info->username, sizeof(ut.ut_user));
+#ifdef HAVE_UTMPX_UT_HOST
         g_strncpy(ut.ut_host, login_info->ip_addr, sizeof(ut.ut_host));
+#endif
+    }
+
+#ifdef HAVE_UTMPX_UT_EXIT
+    if (e != NULL && e->reason == E_PXR_STATUS_CODE)
+    {
+        ut.ut_exit.e_exit = e->val;
     }
+    else if (e != NULL && e->reason == E_PXR_SIGNAL)
+    {
+        ut.ut_exit.e_termination = e->val;
+    }
+#endif
 
     /* update the utmp file */
     /* open utmp */
@@ -124,15 +133,15 @@ utmp_login(int pid, int display, const struct login_info *login_info)
                 "adding login info for utmp: %d - %d - %s - %s",
                 pid, display, login_info->username, login_info->ip_addr);
 
-    add_xtmp_entry(pid, display, login_info, MODE_LOGIN);
+    add_xtmp_entry(pid, display, login_info, MODE_LOGIN, NULL);
 }
 
 void
-utmp_logout(int pid, int display)
+utmp_logout(int pid, int display, const struct proc_exit_status *exit_status)
 {
 
     log_message(LOG_LEVEL_DEBUG, "adding logout info for utmp: %d - %d",
                 pid, display);
 
-    add_xtmp_entry(pid, display, NULL, MODE_LOGOUT);
+    add_xtmp_entry(pid, display, NULL, MODE_LOGOUT, exit_status);
 }

sesman/sesexec/sessionrecord.h

@@ -27,6 +27,7 @@
 #define SESSIONRECORD_H
 
 struct login_info;
+struct proc_exit_status;
 
 /**
  * @brief Record login in utmp
@@ -35,14 +36,17 @@ struct login_info;
  * @param display Display number
  * @param login_info Information about logged in user
  */
-void utmp_login(int pid, int display, const struct login_info *login_info);
+void
+utmp_login(int pid, int display, const struct login_info *login_info);
 
 /**
  * @brief Record logout in utmp
  *
  * @param pid PID of window manager
  * @param display Display number
+ * @param exit_status Exit status of process
  */
-void utmp_logout(int pid, int display);
+void
+utmp_logout(int pid, int display, const struct proc_exit_status *exit_status);
 
 #endif