Add process grouping/tracking

On Linux, this adds an optional dependency on cgmanager to use
cgroups to manage and track processes. This is more reliable and
secure than the XDG_SESSION_COOKIE however it will fall back to
that.
https://github.com/ConsoleKit2/ConsoleKit2/issues/7

7 files changed, 404 insertions, 20 deletions

diff --git a/README b/README
index f9fd2f6..0f40cfc 100644
--- a/README
+++ b/README
@@ -2,7 +2,10 @@ What is ConsoleKit2?
 ===================
 
 ConsoleKit2 is a framework for defining and tracking users, login
-sessions, and seats.
+sessions, and seats. It allows multiple users to be logged in at the
+same time and share hardware for their graphical session. ConsoleKit2
+will keep track of those resources and whichever session is active
+will have use of the hardware at that time.
 
 What is a seat?
 ===============
@@ -36,6 +39,7 @@ Minimum Requirements
 * inotify (optional)
 * RBAC (optional)
 * pm-utils (optional, but required for suspend/hibernate on Linux)
+* cgmanager (recommended on Linux, for process tracking)
 
 Additionally, on Linux CONFIG_AUDITSYSCALL=y is required for
 pam_ck_connector.so to work (PAM support).
diff --git a/configure.ac b/configure.ac
index d768f3f..37a3c63 100644
--- a/configure.ac
+++ b/configure.ac
@@ -274,6 +274,25 @@ AM_CONDITIONAL(ENABLE_PAM_MODULE, test "x$enable_pam_module" = "xyes")
 AC_CHECK_LIB(pam_misc, misc_conv, have_linuxpam=yes)
 AM_CONDITIONAL(HAVE_LINUXPAM, test "x$have_linuxpam" = "xyes")
 
+
+# cgroups - Using the kernel to track processes instead of the cookie
+have_cgmanager=no
+AC_ARG_ENABLE([cgroups],
+  AS_HELP_STRING([--enable-cgroups], [Enable cgroup support @<:@default=auto@:>@]),
+  [enable_cgroups=$enableval],
+  [enable_cgroups=auto])
+AS_IF([test "x$enable_cgroups" != "xno"], [
+  PKG_CHECK_MODULES([CGMANAGER], [libcgmanager libnih >= 1.0.2 libnih-dbus >= 1.0.0], [have_cgmanager=yes], [have_cgmanager=no])
+  if test "x$enable_cgroups"  = "xyes" -a "x$have_cgmanager" = "xno"; then
+    AC_MSG_ERROR([cgroup support explicitly requested but dependencies not found])
+  fi
+])
+AS_IF([test "x$have_cgmanager" = "xyes"], [
+  AC_DEFINE([HAVE_CGMANAGER], [], [Define if we have cgmanager])
+])
+AM_CONDITIONAL([HAVE_CGMANAGER], [test "x$have_cgmanager" = "xyes"])
+AC_SUBST(HAVE_CGMANAGER)
+
 dnl ------------------------------------------------------------------------------
 dnl udev-acl - apply ACLs for users with local forground sessions
 dnl ------------------------------------------------------------------------------
@@ -553,6 +572,7 @@ echo "
         PAM module dir:           ${PAM_MODULE_DIR}
         Build PAM module:         ${msg_pam_module}
         Build udev-acl:           ${enable_udev_acl}
+        cgroup support:           ${have_cgmanager}
         Build docs:               ${enable_docbook_docs}
         xinitrc dir:              ${XINITRC_DIR}
 
diff --git a/src/Makefile.am b/src/Makefile.am
index 091ef27..7a7dd24 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -12,6 +12,7 @@ AM_CFLAGS =							\
 	-U_FORTIFY_SOURCE				\
 	$(CONSOLE_KIT_CFLAGS)					\
 	$(POLKIT_CFLAGS)					\
+	$(CGMANAGER_CFLAGS)					\
 	$(DISABLE_DEPRECATED_CFLAGS)				\
 	-DPREFIX=\""$(prefix)"\" 				\
 	-DBINDIR=\""$(bindir)"\"				\
@@ -157,6 +158,8 @@ console_kit_daemon_SOURCES =	\
 	ck-inhibit.h		\
 	ck-inhibit-manager.c	\
 	ck-inhibit-manager.h	\
+	ck-process-group.h	\
+	ck-process-group.c	\
 	$(BUILT_SOURCES)	\
 	$(NULL)
 
@@ -177,6 +180,7 @@ console_kit_daemon_LDADD =	\
 	$(CONSOLE_KIT_LIBS)	\
 	$(POLKIT_LIBS)		\
 	$(RBAC_LIBS)		\
+	$(CGMANAGER_LIBS)	\
 	libck.la		\
 	libck-event-log.la	\
 	$(NULL)
diff --git a/src/ck-manager.c b/src/ck-manager.c
index f7e0b05..a23e414 100644
--- a/src/ck-manager.c
+++ b/src/ck-manager.c
@@ -54,6 +54,7 @@
 #include "ck-inhibit-manager.h"
 #include "ck-inhibit.h"
 #include "ck-sysdeps.h"
+#include "ck-process-group.h"
 
 #define CK_MANAGER_GET_PRIVATE(o) (G_TYPE_INSTANCE_GET_PRIVATE ((o), CK_TYPE_MANAGER, CkManagerPrivate))
 
@@ -789,11 +790,28 @@ static char *
 get_cookie_for_pid (CkManager *manager,
                     guint      pid)
 {
-        char *cookie;
+        char            *cookie = NULL;
+        gchar           *ssid = NULL;
+        CkProcessGroup  *pgroup;
+        CkSession       *session;
+
+        pgroup = ck_process_group_get ();
+
+        ssid = ck_process_group_get_ssid (pgroup, pid);
+
+        if (ssid != NULL) {
+                g_debug ("looking for session for ssid %s", ssid);
+                session = g_hash_table_lookup (manager->priv->sessions, ssid);
+                if (session != NULL) {
+                        g_object_get (session, "cookie", &cookie, NULL);
+                }
 
-        /* FIXME: need a better way to get the cookie */
+                g_free (ssid);
+        }
 
-        cookie = ck_unix_pid_get_env (pid, "XDG_SESSION_COOKIE");
+        if (cookie == NULL) {
+                cookie = ck_unix_pid_get_env (pid, "XDG_SESSION_COOKIE");
+        }
 
         return cookie;
 }
@@ -2559,10 +2577,11 @@ open_session_for_leader (CkManager             *manager,
                          gboolean               is_local,
                          GDBusMethodInvocation *context)
 {
-        CkSession   *session;
-        CkSeat      *seat;
-        const char  *ssid;
-        const char  *cookie;
+        CkProcessGroup *pgroup;
+        CkSession      *session;
+        CkSeat         *seat;
+        const char     *ssid;
+        const char     *cookie;
 
         ssid = ck_session_leader_peek_session_id (leader);
         cookie = ck_session_leader_peek_cookie (leader);
@@ -2577,6 +2596,13 @@ open_session_for_leader (CkManager             *manager,
                 return;
         }
 
+        /* If supported, add the session leader to a process group so we
+         * can track it with something better than an environment variable */
+        pgroup = ck_process_group_get ();
+        ck_process_group_create (pgroup,
+                                 ck_session_leader_get_pid (leader),
+                                 ssid);
+
         g_hash_table_insert (manager->priv->sessions,
                              g_strdup (ssid),
                              g_object_ref (session));
diff --git a/src/ck-process-group.c b/src/ck-process-group.c
new file mode 100644
index 0000000..b1e079f
--- /dev/null
+++ b/src/ck-process-group.c
@@ -0,0 +1,275 @@
+/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 8 -*-
+ *
+ * Copyright (c) 2015, Eric Koegel <eric.koegel@gmail.com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+
+#include <glib.h>
+#include <glib-object.h>
+#include <glib/gstdio.h>
+
+#ifdef HAVE_CGMANAGER
+#include <cgmanager/cgmanager.h>
+#include <cgmanager/cgmanager-client.h>
+#include <nih/alloc.h>
+#include <nih/error.h>
+#include <nih/string.h>
+#endif
+
+/* For TRACE */
+#include "ck-sysdeps.h"
+
+#include "ck-process-group.h"
+
+#define CK_PROCESS_GROUP_GET_PRIVATE(o) (G_TYPE_INSTANCE_GET_PRIVATE ((o), CK_TYPE_PROCESS_GROUP, CkProcessGroupPrivate))
+
+struct CkProcessGroupPrivate
+{
+        gint          unused;
+#ifdef HAVE_CGMANAGER
+        NihDBusProxy *cgmanager_proxy;
+#endif
+};
+
+static void     ck_process_group_class_init  (CkProcessGroupClass *klass);
+static void     ck_process_group_init        (CkProcessGroup      *pgroup);
+static void     ck_process_group_finalize    (GObject             *object);
+
+G_DEFINE_TYPE (CkProcessGroup, ck_process_group, G_TYPE_OBJECT)
+
+static gboolean
+ck_process_group_backend_init (CkProcessGroup *pgroup)
+{
+#ifdef HAVE_CGMANAGER
+        DBusError       dbus_error;
+        DBusConnection *connection = NULL;
+
+        TRACE ();
+
+        dbus_error_init (&dbus_error);
+
+        /* cgmanager uses a dbus based socket rather than running on the
+         * system bus, nify. Let's connect to it.
+         */
+        connection = dbus_connection_open_private (CGMANAGER_DBUS_PATH, &dbus_error);
+        if (!connection) {
+                g_warning (_("Failed to open connection to cgmanager. Is the cgmanager service running?"));
+                dbus_error_free (&dbus_error);
+                return FALSE;
+        }
+
+        dbus_connection_set_exit_on_disconnect (connection, FALSE);
+        dbus_error_free (&dbus_error);
+
+        pgroup->priv->cgmanager_proxy = nih_dbus_proxy_new (NULL, connection, NULL, "/org/linuxcontainers/cgmanager", NULL, NULL);
+        dbus_connection_unref (connection);
+        if (!pgroup->priv->cgmanager_proxy) {
+                NihError *nerr;
+                nerr = nih_error_get ();
+                g_warning ("cgmanager initialization error: %s", nerr->message);
+                nih_free (nerr);
+                return FALSE;
+        }
+#endif
+        return TRUE;
+}
+
+/**
+ * ck_process_group_get:
+ *
+ * Increases the reference count of the @CkProcessGroup object.
+ *
+ * Return value:  Returns the CkProcessGroup object or
+ *                NULL on failure. Do not unref when finished. [transfer: none]
+ **/
+CkProcessGroup*
+ck_process_group_get (void)
+{
+        static GObject *manager = NULL;
+
+        if (manager == NULL) {
+                manager = g_object_new (CK_TYPE_PROCESS_GROUP, NULL);
+
+                g_object_add_weak_pointer (manager,
+                                           (gpointer *) &manager);
+
+                ck_process_group_backend_init (CK_PROCESS_GROUP (manager));
+        }
+
+        return CK_PROCESS_GROUP (manager);
+}
+
+static void
+ck_process_group_class_init (CkProcessGroupClass *klass)
+{
+        GObjectClass   *object_class = G_OBJECT_CLASS (klass);
+
+        object_class->finalize = ck_process_group_finalize;
+
+        g_type_class_add_private (klass, sizeof (CkProcessGroupPrivate));
+}
+
+static void
+ck_process_group_init (CkProcessGroup *pgroup)
+{
+        pgroup->priv = CK_PROCESS_GROUP_GET_PRIVATE (pgroup);
+}
+
+static void
+ck_process_group_finalize (GObject *object)
+{
+#ifdef HAVE_CGMANAGER
+        CkProcessGroupPrivate *priv = CK_PROCESS_GROUP_GET_PRIVATE (object);
+
+        if (priv->cgmanager_proxy) {
+                dbus_connection_flush(priv->cgmanager_proxy->connection);
+                dbus_connection_close(priv->cgmanager_proxy->connection);
+                nih_free(priv->cgmanager_proxy);
+        }
+        priv->cgmanager_proxy = NULL;
+#endif
+
+        G_OBJECT_CLASS (ck_process_group_parent_class)->finalize (object);
+}
+
+/**
+ * ck_process_group_create:
+ * @CkProcessGroup: the pgroup object.
+ * @process: the process to add to the new group
+ * @ssid: the session id.
+ *
+ * Creates a new process group named @ssid and places @process inside it.
+ *
+ * Return value:  TRUE on success, FALSE if process groups are unsupported
+ *                on this platform.
+ **/
+gboolean
+ck_process_group_create (CkProcessGroup *pgroup,
+                         pid_t process,
+                         const gchar *ssid)
+{
+#ifdef HAVE_CGMANAGER
+        CkProcessGroupPrivate *priv = CK_PROCESS_GROUP_GET_PRIVATE (pgroup);
+        gint                   ret;
+        gint32                 existed;
+
+        TRACE ();
+
+        if (priv->cgmanager_proxy == NULL) {
+                g_debug ("cgmanager_proxy == NULL");
+                return FALSE;
+        }
+
+        /* Create the cgroup, move the pid into it, and then tell cgmanager
+         * to clean up the cgroup after all the processes are gone which
+         * will happen when the user logs out.
+         */
+        ret = cgmanager_create_sync (NULL, priv->cgmanager_proxy, "cpuacct", ssid, &existed);
+        if (ret != 0) {
+                NihError *nerr;
+                nerr = nih_error_get();
+                g_debug ("failed to create cgroup: %s", nerr->message);
+                nih_free(nerr);
+                return FALSE;
+        }
+
+        ret = cgmanager_move_pid_abs_sync (NULL, priv->cgmanager_proxy, "cpuacct", ssid, process);
+        if (ret != 0) {
+                NihError *nerr;
+                nerr = nih_error_get();
+                g_debug ("failed to move pid to cgroup: %s", nerr->message);
+                nih_free(nerr);
+                return FALSE;
+        }
+
+        ret = cgmanager_remove_on_empty_sync (NULL, priv->cgmanager_proxy, "cpuacct", ssid);
+        if (ret != 0) {
+                NihError *nerr;
+                nerr = nih_error_get();
+                g_debug ("cgmanager_remove_on_empty_sync error: %s", nerr->message);
+                nih_free(nerr);
+                return FALSE;
+        }
+
+        return TRUE;
+#endif
+        return FALSE;
+}
+
+/**
+ * ck_process_group_get_ssid:
+ * @CkProcessGroup: the pgroup object.
+ * @process: the process to add to the new group
+ *
+ * Return value: the ssid of the pid, otherwise NULL
+ **/
+gchar*
+ck_process_group_get_ssid (CkProcessGroup *pgroup,
+                           pid_t process)
+{
+#ifdef HAVE_CGMANAGER
+        CkProcessGroupPrivate *priv = CK_PROCESS_GROUP_GET_PRIVATE (pgroup);
+        gint                   ret;
+        char                  *nih_ssid = NULL;
+        gchar                 *g_ssid = NULL;
+
+        TRACE ();
+
+        if (priv->cgmanager_proxy == NULL) {
+                g_debug ("cgmanager_proxy == NULL");
+                return NULL;
+        }
+
+        ret = cgmanager_get_pid_cgroup_abs_sync (NULL, priv->cgmanager_proxy, "cpuacct", process, &nih_ssid);
+        if (ret != 0) {
+                NihError *nerr;
+                nerr = nih_error_get();
+                g_debug ("cgmanager_get_pid_cgroup_abs_sync error: %s", nerr->message);
+                nih_free(nerr);
+                return NULL;
+        }
+
+        /* This is probably why you don't mix toolkits. So memory allocated
+         * with nih causes corruption issues with glib, so copy + free it */
+        if (nih_ssid != NULL) {
+                g_ssid = g_strdup (nih_ssid);
+
+                nih_free (nih_ssid);
+        }
+
+        /* ignore the unknown/root cgroup */
+        if (g_strcmp0 (g_ssid, "/") == 0) {
+                g_free (g_ssid);
+                g_ssid = NULL;
+        }
+
+        return g_ssid;
+#endif
+        return NULL;
+}
+
diff --git a/src/ck-process-group.h b/src/ck-process-group.h
new file mode 100644
index 0000000..36ed189
--- /dev/null
+++ b/src/ck-process-group.h
@@ -0,0 +1,67 @@
+/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 8 -*-
+ *
+ * Copyright (c) 2015, Eric Koegel <eric.koegel@gmail.com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef __CK_PROCESS_GROUP_H_
+#define __CK_PROCESS_GROUP_H_
+
+#include <glib-object.h>
+
+#define CK_TYPE_PROCESS_GROUP           (ck_process_group_get_type ())
+#define CK_PROCESS_GROUP(o)             (G_TYPE_CHECK_INSTANCE_CAST ((o), CK_TYPE_PROCESS_GROUP, CkProcessGroup))
+#define CK_PROCESS_GROUP_CLASS(k)       (G_TYPE_CHECK_CLASS_CAST((k), CK_TYPE_PROCESS_GROUP, CkProcessGroupClass))
+#define CK_IS_PROCESS_GROUP(o)          (G_TYPE_CHECK_INSTANCE_TYPE ((o), CK_TYPE_PROCESS_GROUP))
+#define CK_IS_PROCESS_GROUP_CLASS(k)    (G_TYPE_CHECK_CLASS_TYPE ((k), CK_TYPE_PROCESS_GROUP))
+#define CK_PROCESS_GROUP_GET_CLASS(o)   (G_TYPE_INSTANCE_GET_CLASS ((o), CK_TYPE_PROCESS_GROUP, CkProcessGroupClass))
+
+typedef struct CkProcessGroupPrivate CkProcessGroupPrivate;
+
+typedef struct
+{
+        GObject           parent;
+        CkProcessGroupPrivate *priv;
+} CkProcessGroup;
+
+typedef struct
+{
+        GObjectClass parent_class;
+} CkProcessGroupClass;
+
+
+GType             ck_process_group_get_type         (void);
+
+CkProcessGroup   *ck_process_group_get              (void);
+
+gboolean          ck_process_group_create           (CkProcessGroup *pgroup,
+                                                     pid_t process,
+                                                     const gchar *ssid);
+
+gchar            *ck_process_group_get_ssid         (CkProcessGroup *pgroup,
+                                                     pid_t process);
+
+#endif /* __CK_PROCESS_GROUP_H_ */
diff --git a/src/ck-session.h b/src/ck-session.h
index d34f88c..d9b35cd 100644
--- a/src/ck-session.h
+++ b/src/ck-session.h
@@ -87,15 +87,6 @@ gboolean            ck_session_set_active             (CkSession             *se
 gboolean            ck_session_set_is_local           (CkSession             *session,
                                                        gboolean               is_local,
                                                        GError               **error);
-gboolean            ck_session_set_id                 (CkSession             *session,
-                                                       const char            *ssid,
-                                                       GError               **error);
-gboolean            ck_session_set_cookie             (CkSession             *session,
-                                                       const char            *cookie,
-                                                       GError               **error);
-gboolean            ck_session_set_seat_id            (CkSession             *session,
-                                                       const char            *sid,
-                                                       GError               **error);
 gboolean            ck_session_set_unix_user          (CkSession             *session,
                                                        guint                  uid,
                                                        GError               **error);
@@ -108,9 +99,6 @@ gboolean            ck_session_set_x11_display_device (CkSession             *se
 gboolean            ck_session_set_display_device     (CkSession             *session,
                                                        const char            *device,
                                                        GError               **error);
-gboolean            ck_session_set_login_session_id   (CkSession             *session,
-                                                       const char            *login_session_id,
-                                                       GError               **error);
 gboolean            ck_session_set_remote_host_name   (CkSession             *session,
                                                        const char            *remote_host_name,
                                                        GError               **error);