add pkexec support

closes #85

try pkexec before trying gksu for killing other users' processes
or renicing a process. actual kill and renice commands are launched
via helper tool (see discussion at https://bugzilla.gnome.org/491462).

code is ported from gnome-system-monitor with some changes (e.g. helper
tool code is in tools/ dir instead of scripts/ - it's not a script).

for reference - relevant upstream commits:
https://git.gnome.org/browse/gnome-system-monitor/commit/?id=ccbff2a4293e43d6ea24fbf13477b10f58cd5212
https://git.gnome.org/browse/gnome-system-monitor/commit/?id=2b4308d9fc2b2e367030629e79b531c4f9ae3d0a
https://git.gnome.org/browse/gnome-system-monitor/commit/?id=971b3c704dea49b22c1038f200933c5b3b35ece1
https://git.gnome.org/browse/gnome-system-monitor/commit/?id=c234b2a75dac454b818f1f40d302cf12f1a33aa2
https://git.gnome.org/browse/gnome-system-monitor/commit/?id=4cda3529e418098b35f7444d79ba421eb5403afc
https://git.gnome.org/browse/gnome-system-monitor/commit/?id=ab7bd8aef7300eeb3835fdef9a2a1eefe7281631
https://git.gnome.org/browse/gnome-system-monitor/commit/?id=79eccf0cecbca237f4f911681438c33932da63e2
https://git.gnome.org/browse/gnome-system-monitor/commit/?id=a3bf3a7f56cf02c6a127aa168c570230e9fad356

Makefile.am

@@ -2,7 +2,7 @@
 
 ACLOCAL_AMFLAGS = -I m4 ${ACLOCAL_FLAGS}
 
-SUBDIRS = pixmaps po src help
+SUBDIRS = pixmaps po src tools help
 
 man_MANS = mate-system-monitor.1
 
@@ -11,17 +11,26 @@ appdatadir = $(datadir)/appdata
 appdata_in_files = mate-system-monitor.appdata.xml.in
 appdata_DATA = $(appdata_in_files:.xml.in=.xml)
 
+org.mate.mate-system-monitor.policy.in: org.mate.mate-system-monitor.policy.in.in Makefile
+	$(AM_V_GEN) sed -e "s|\@pkglibexecdir\@|$(pkglibexecdir)|" $< > $@
+
 EXTRA_DIST = \
 	autogen.sh \
 	$(man_MANS) \
 	$(appdata_in_files) \
+	org.mate.mate-system-monitor.policy.in.in \
 	mate-system-monitor.desktop.in \
 	intltool-extract.in \
 	intltool-merge.in \
 	intltool-update.in \
 	omf.make \
 	xmldocs.make
 
+@INTLTOOL_POLICY_RULE@
+polkit_policydir = $(datadir)/polkit-1/actions
+polkit_policy_in_files = org.mate.mate-system-monitor.policy.in
+polkit_policy_DATA = $(polkit_policy_in_files:.policy.in=.policy)
+
 Applicationsdir = $(datadir)/applications
 Applications_in_files = mate-system-monitor.desktop.in
 Applications_DATA = $(Applications_in_files:.desktop.in=.desktop)
@@ -35,7 +44,9 @@ DISTCLEANFILES = \
   intltool-extract \
   intltool-merge \
   intltool-update \
-  mate-system-monitor.desktop
+  mate-system-monitor.desktop \
+  org.mate.mate-system-monitor.policy \
+  org.mate.mate-system-monitor.policy.in
 
 # Build ChangeLog from GIT  history
 ChangeLog:

configure.ac

@@ -46,6 +46,8 @@ AC_DEFINE([GLIB_VERSION_MIN_REQUIRED], [GLIB_VERSION_2_36],
 PKG_CHECK_MODULES(GMODULE,gmodule-2.0,[GMODULE_ADD="gmodule-2.0"],[GMODULE_ADD=""])
 PKG_CHECK_MODULES(PROCMAN,$GMODULE_ADD glib-2.0 >= $GLIB_REQUIRED libgtop-2.0 >= $LIBGTOP_REQUIRED libwnck-3.0 >= $LIBWNCK_REQUIRED gtk+-3.0 >= $GTK_REQUIRED gtkmm-3.0 >= $GTKMM_REQUIRED libxml-2.0 >= $LIBXML_REQUIRED librsvg-2.0 >= $RSVG_REQUIRED glibmm-2.4 >= $GLIBMM_REQUIRED giomm-2.4 >= $GIOMM_REQUIRED)
 
+PKG_CHECK_MODULES(TOOLS, glib-2.0 >= $GLIB_REQUIRED)
+
 have_systemd=no
 AC_ARG_ENABLE(systemd, AS_HELP_STRING([--disable-systemd], [disable systemd support]),,enable_systemd=no)
 if test "x$enable_systemd" != "xno"; then
@@ -107,6 +109,7 @@ src/org.mate.system-monitor.gschema.xml
 pixmaps/Makefile
 po/Makefile.in
 help/Makefile
+tools/Makefile
 mate-system-monitor.desktop.in
 ])
 

org.mate.mate-system-monitor.policy.in.in

@@ -0,0 +1,32 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE policyconfig PUBLIC
+ "-//freedesktop//DTD PolicyKit Policy Configuration 1.0//EN"
+ "http://www.freedesktop.org/standards/PolicyKit/1.0/policyconfig.dtd">
+<policyconfig>
+  <vendor>MATE Desktop</vendor>
+  <vendor_url>http://www.mate-desktop.org/</vendor_url>
+  <icon_name>utilities-system-monitor</icon_name>
+
+  <action id="org.mate.mate-system-monitor.kill">
+    <_description>Kill process</_description>
+    <_message>Privileges are required to control other users' processes</_message>
+    <defaults>
+      <allow_any>no</allow_any>
+      <allow_inactive>no</allow_inactive>
+      <allow_active>auth_admin_keep</allow_active>
+    </defaults>
+    <annotate key="org.freedesktop.policykit.exec.path">@pkglibexecdir@/msm-kill</annotate>
+  </action>
+
+  <action id="org.mate.mate-system-monitor.renice">
+    <_description>Renice process</_description>
+    <_message>Privileges are required to change the priority of processes</_message>
+    <defaults>
+      <allow_any>no</allow_any>
+      <allow_inactive>no</allow_inactive>
+      <allow_active>auth_admin_keep</allow_active>
+    </defaults>
+    <annotate key="org.freedesktop.policykit.exec.path">@pkglibexecdir@/msm-renice</annotate>
+  </action>
+
+</policyconfig>

po/POTFILES.in

@@ -3,6 +3,7 @@
 # Please keep this file sorted alphabetically.
 mate-system-monitor.appdata.xml.in
 mate-system-monitor.desktop.in.in
+org.mate.mate-system-monitor.policy.in.in
 src/argv.cpp
 src/argv.h
 src/callbacks.cpp

po/POTFILES.skip

@@ -1 +1,2 @@
 mate-system-monitor.desktop.in
+org.mate.mate-system-monitor.policy.in

src/Makefile.am

@@ -4,6 +4,7 @@ AM_CPPFLAGS = \
 	-DPROCMAN_DATADIR=\""$(datadir)/procman/"\" \
 	-DMATELOCALEDIR=\""$(datadir)/locale"\" \
 	-DDATADIR=\""$(datadir)"\" \
+	-DLIBEXEC_DIR=\""$(pkglibexecdir)"\" \
 	@PROCMAN_CFLAGS@ \
 	@SYSTEMD_CFLAGS@
 
@@ -28,6 +29,7 @@ mate_system_monitor_cpp_files = \
 	selinux.cpp \
 	cgroups.cpp \
 	procman_gksu.cpp \
+	procman_pkexec.cpp \
 	sysinfo.cpp \
 	lsof.cpp \
 	selection.cpp \

src/procdialogs.cpp

@@ -34,6 +34,7 @@
 #include "load-graph.h"
 #include "settings-keys.h"
 #include "procman_gksu.h"
+#include "procman_pkexec.h"
 #include "cgroups.h"
 
 
@@ -894,7 +895,9 @@ procdialog_create_root_password_dialog(ProcmanActionType type,
 
     procman_debug("Trying to run '%s' as root", command);
 
-    if (procman_has_gksu())
+    if (procman_has_pkexec())
+        ret = procman_pkexec_create_root_password_dialog(command);
+    else if (procman_has_gksu())
         ret = procman_gksu_create_root_password_dialog(command);
 
     g_free(command);

src/procman_pkexec.cpp

@@ -0,0 +1,33 @@
+#include <config.h>
+
+#include "procman_pkexec.h"
+
+gboolean
+procman_pkexec_create_root_password_dialog (const char *command)
+{
+    gchar *command_line;
+    gboolean success;
+    GError *error = NULL;
+
+    command_line = g_strdup_printf ("pkexec --disable-internal-agent %s/msm-%s",
+                                    LIBEXEC_DIR, command);
+    success = g_spawn_command_line_sync (command_line, NULL, NULL, NULL, &error);
+    g_free (command_line);
+
+    if (!success) {
+        g_critical ("Could not run pkexec (\"%s\") : %s\n",
+                    command, error->message);
+        g_error_free (error);
+        return FALSE;
+    }
+
+    g_debug ("pkexec did fine\n");
+    return TRUE;
+}
+
+gboolean
+procman_has_pkexec (void)
+{
+    return g_file_test("/usr/bin/pkexec", G_FILE_TEST_EXISTS);
+}
+

src/procman_pkexec.h

@@ -0,0 +1,12 @@
+#ifndef _PROCMAN_PKEXEC_H_
+#define _PROCMAN_PKEXEC_H_
+
+#include <glib.h>
+
+gboolean
+procman_pkexec_create_root_password_dialog(const char *command);
+
+gboolean
+procman_has_pkexec(void) G_GNUC_CONST;
+
+#endif /* _PROCMAN_PKEXEC_H_ */

tools/Makefile.am

@@ -0,0 +1,12 @@
+pkglibexec_PROGRAMS = msm-renice msm-kill
+
+AM_CPPFLAGS = $(TOOLS_CFLAGS)
+
+msm_renice_SOURCES = msm_execute_helper.c
+msm_renice_LDADD = $(TOOLS_LIBS)
+msm_renice_CFLAGS = -DCOMMAND=\"renice\"
+
+msm_kill_SOURCES = msm_execute_helper.c
+msm_kill_LDADD = $(TOOLS_LIBS)
+msm_kill_CFLAGS = -DCOMMAND=\"kill\"
+

tools/msm_execute_helper.c

@@ -0,0 +1,17 @@
+#include <unistd.h>
+#include <errno.h>
+#include <string.h>
+#include <glib.h>
+
+int main(int argc, char* argv[])
+{
+    gchar **argv_modified = g_new0 (gchar *, argc + 1);
+    memcpy (argv_modified, argv, argc * sizeof (char*));
+    argv_modified[0] = COMMAND;
+
+    if (execvp (COMMAND, argv_modified) == -1) {
+        return errno;
+    }
+
+    return 0;
+}