From a9aa00ff0fea79452a60a2448dd1f2714918884a Mon Sep 17 00:00:00 2001
From: William Jon McCann <mccann@jhu.edu>
Date: Wed, 18 Jul 2007 17:24:00 -0400
Subject: Add new helper for getting tty from DISPLAY

---
 tools/linux/Makefile.am                 |  11 +++
 tools/linux/ck-get-x11-display-device.c | 138 ++++++++++++++++++++++++++++++++
 2 files changed, 149 insertions(+)
 create mode 100644 tools/linux/ck-get-x11-display-device.c

diff --git a/tools/linux/Makefile.am b/tools/linux/Makefile.am
index 3283b5e..4b570a7 100644
--- a/tools/linux/Makefile.am
+++ b/tools/linux/Makefile.am
@@ -26,6 +26,7 @@ INCLUDES =							\
 libexec_PROGRAMS = 			\
 	ck-collect-session-info		\
 	ck-get-x11-server-pid		\
+	ck-get-x11-display-device	\
 	$(NULL)
 
 ck_collect_session_info_SOURCES =	\
@@ -46,6 +47,16 @@ ck_get_x11_server_pid_LDADD =		\
 	$(TOOLS_LIBS)			\
 	$(NULL)
 
+ck_get_x11_display_device_SOURCES =		\
+	$(top_srcdir)/src/proc.h	\
+	$(top_srcdir)/src/proc-linux.c	\
+	ck-get-x11-display-device.c		\
+	$(NULL)
+
+ck_get_x11_display_device_LDADD =		\
+	$(TOOLS_LIBS)			\
+	$(NULL)
+
 EXTRA_DIST =				\
 	$(NULL)
 
diff --git a/tools/linux/ck-get-x11-display-device.c b/tools/linux/ck-get-x11-display-device.c
new file mode 100644
index 0000000..c0d3772
--- /dev/null
+++ b/tools/linux/ck-get-x11-display-device.c
@@ -0,0 +1,138 @@
+/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 8 -*-
+ *
+ * Copyright (C) 2007 William Jon McCann <mccann@jhu.edu>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This program 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
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+ * 02111-1307, USA.
+ *
+ * Authors: William Jon McCann <mccann@jhu.edu>
+ *
+ */
+
+#include "config.h"
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+
+#include <X11/Xlib.h>
+#include <glib.h>
+
+#include "proc.h"
+
+static char *
+get_tty_for_pid (int pid)
+{
+        GError *error;
+        char   *device;
+        gboolean res;
+        proc_stat_t *xorg_stat;
+
+        error = NULL;
+        res = proc_stat_new_for_pid (pid, &xorg_stat, &error);
+        if (! res) {
+                if (error != NULL) {
+                        g_warning ("stat on pid %d failed: %s", pid, error->message);
+                        g_error_free (error);
+                }
+                /* keep the tty value */
+                return NULL;
+        }
+
+        device = proc_stat_get_tty (xorg_stat);
+        proc_stat_free (xorg_stat);
+        return device;
+}
+
+static int
+get_peer_pid (int fd)
+{
+        int pid = -1;
+#ifdef SO_PEERCRED
+        struct ucred cr;
+        socklen_t cr_len;
+
+        cr_len = sizeof (cr);
+
+        if (getsockopt (fd, SOL_SOCKET, SO_PEERCRED, &cr, &cr_len) == 0 && cr_len == sizeof (cr)) {
+                /* paranoia check for peer running as root */
+                if (cr.uid == 0) {
+                        pid = cr.pid;
+                }
+        } else {
+                g_warning ("Failed to getsockopt() credentials, returned len %d/%d: %s\n",
+                           cr_len,
+                           (int) sizeof (cr),
+                           g_strerror (errno));
+        }
+#endif
+        return pid;
+}
+
+static Display *
+display_init (int *argc, char ***argv)
+{
+        const char *display_name;
+        Display    *xdisplay;
+
+        display_name = g_getenv ("DISPLAY");
+
+        if (display_name == NULL) {
+                g_warning ("DISPLAY is not set");
+                exit (1);
+        }
+
+        xdisplay = XOpenDisplay (display_name);
+        if (xdisplay == NULL) {
+                g_warning ("cannot open display: %s", display_name ? display_name : "");
+                exit (1);
+        }
+
+        return xdisplay;
+}
+
+int
+main (int    argc,
+      char **argv)
+{
+        int      fd;
+        int      ret;
+        Display *xdisplay;
+
+        ret = 1;
+
+        xdisplay = display_init (&argc, &argv);
+
+        fd = ConnectionNumber (xdisplay);
+
+        if (fd > 0) {
+                int pid;
+                char *device;
+
+                ret = 0;
+                pid = get_peer_pid (fd);
+                if (pid != -1) {
+                        device = get_tty_for_pid (pid);
+                        if (device != NULL) {
+                                printf ("%s\n", device);
+                                g_free (device);
+                        }
+                }
+        }
+
+	return ret;
+}
-- 
cgit