add interface to PolicyKit

git-svn-id: file:///home/lennart/svn/public/pulseaudio/trunk@2060 fefdeb5f-60dc-0310-8127-8f9354f1896f

src/daemon/PulseAudio.policy

@@ -0,0 +1,49 @@
+<?xml version="1.0" encoding="UTF-8"?><!--*-nxml-*-->
+<!DOCTYPE policyconfig PUBLIC
+ "-//freedesktop//DTD PolicyKit Policy Configuration 1.0//EN"
+ "http://www.freedesktop.org/standards/PolicyKit/1.0/policyconfig.dtd">
+
+<!-- $Id$ -->
+
+<!--
+This file is part of PulseAudio.
+
+PulseAudio is free software; you can redistribute it and/or modify it
+under the terms of the GNU Lesser General Public License as
+published by the Free Software Foundation; either version 2.1 of the
+License, or (at your option) any later version.
+
+PulseAudio 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 Lesser General
+Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public
+License along with PulseAudio; if not, write to the Free Software
+Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
+USA.
+-->
+
+<policyconfig>
+
+  <action id="org.pulseaudio.acquire-real-time">
+    <description>Real-time scheduling for the PulseAudio daemon</description>
+    <message>System policy prevents PulseAudio from acquiring real-time scheduling.</message>
+    <defaults>
+      <allow_any>no</allow_any>
+      <allow_inactive>no</allow_inactive>
+      <allow_active>auth_admin_keep_always</allow_active>
+    </defaults>
+  </action>
+
+  <action id="org.pulseaudio.acquire-high-priority">
+    <description>High-priority scheduling (negative Unix nice level) for the PulseAudio daemon</description>
+    <message>System policy prevents PulseAudio from acquiring high-priority scheduling.</message>
+    <defaults>
+      <allow_any>no</allow_any>
+      <allow_inactive>no</allow_inactive>
+      <allow_active>auth_admin_keep_always</allow_active>
+    </defaults>
+  </action>
+
+</policyconfig>

src/daemon/polkit.c

@@ -0,0 +1,223 @@
+/* $Id$ */
+
+/***
+  This file is part of PulseAudio.
+
+  Copyright 2004-2006 Lennart Poettering
+  Copyright 2006 Pierre Ossman <ossman@cendio.se> for Cendio AB
+
+  PulseAudio is free software; you can redistribute it and/or modify
+  it under the terms of the GNU Lesser General Public License as published
+  by the Free Software Foundation; either version 2 of the License,
+  or (at your option) any later version.
+
+  PulseAudio 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 Lesser General Public License
+  along with PulseAudio; if not, write to the Free Software
+  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
+  USA.
+***/
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <unistd.h>
+#include <stdlib.h>
+#include <inttypes.h>
+
+#include <dbus/dbus.h>
+#include <polkit-dbus/polkit-dbus.h>
+
+#include <pulsecore/log.h>
+#include <pulsecore/macro.h>
+
+#include "polkit.h"
+
+static pa_bool_t show_grant_dialog(const char *action_id) {
+    DBusError dbus_error;
+    DBusConnection *bus = NULL;
+    DBusMessage *m = NULL, *reply = NULL;
+    pa_bool_t r = FALSE;
+    uint32_t xid = 0;
+    int verdict;
+
+    dbus_error_init(&dbus_error);
+
+    if (!(bus = dbus_bus_get(DBUS_BUS_SESSION, &dbus_error))) {
+        pa_log_error("Cannot connect to session bus: %s", dbus_error.message);
+        goto finish;
+    }
+
+    if (!(m = dbus_message_new_method_call("org.gnome.PolicyKit", "/org/gnome/PolicyKit/Manager", "org.gnome.PolicyKit.Manager", "ShowDialog"))) {
+        pa_log_error("Failed to allocate D-Bus message.");
+        goto finish;
+    }
+
+    if (!(dbus_message_append_args(m, DBUS_TYPE_STRING, &action_id, DBUS_TYPE_UINT32, &xid, DBUS_TYPE_INVALID))) {
+        pa_log_error("Failed to append arguments to D-Bus message.");
+        goto finish;
+    }
+
+    if (!(reply = dbus_connection_send_with_reply_and_block(bus, m, -1, &dbus_error))) {
+        pa_log_warn("Failed to show grant dialog: %s", dbus_error.message);
+        goto finish;
+    }
+
+    if (!(dbus_message_get_args(reply, &dbus_error, DBUS_TYPE_BOOLEAN, &verdict, DBUS_TYPE_INVALID))) {
+        pa_log_warn("Malformed response from grant manager: %s", dbus_error.message);
+        goto finish;
+    }
+
+    r = !!verdict;
+
+finish:
+
+    if (bus)
+        dbus_connection_unref(bus);
+
+    dbus_error_free(&dbus_error);
+
+    if (m)
+        dbus_message_unref(m);
+
+    if (reply)
+        dbus_message_unref(reply);
+
+    return r;
+}
+
+int pa_polkit_check(const char *action_id) {
+    int ret = -1;
+    DBusError dbus_error;
+    DBusConnection *bus = NULL;
+    PolKitCaller *caller = NULL;
+    PolKitAction *action = NULL;
+    PolKitContext *context = NULL;
+    PolKitError *polkit_error = NULL;
+    PolKitSession *session = NULL;
+    PolKitResult polkit_result;
+
+    dbus_error_init(&dbus_error);
+
+    if (!(bus = dbus_bus_get(DBUS_BUS_SYSTEM, &dbus_error))) {
+        pa_log_error("Cannot connect to system bus: %s", dbus_error.message);
+        goto finish;
+    }
+
+    if (!(caller = polkit_caller_new_from_pid(bus, getpid(), &dbus_error))) {
+        pa_log_error("Cannot get caller from PID: %s", dbus_error.message);
+        goto finish;
+    }
+
+    /* This function is called when PulseAudio is called SUID root. We
+     * want to authenticate the real user that called us and not the
+     * effective user we gained through being SUID root. Hence we
+     * overwrite the UID caller data here explicitly, just for
+     * paranoia. In fact PolicyKit should fill in the UID here anyway
+     * -- an not the EUID or any other user id. */
+
+    if (!(polkit_caller_set_uid(caller, getuid()))) {
+        pa_log_error("Cannot set UID on caller object.");
+        goto finish;
+    }
+
+    if (!(polkit_caller_get_ck_session(caller, &session))) {
+        pa_log_error("Failed to get CK session.");
+        goto finish;
+    }
+
+    /* We need to overwrite the UID in both the caller and the session
+     * object */
+
+    if (!(polkit_session_set_uid(session, getuid()))) {
+        pa_log_error("Cannot set UID on session object.");
+        goto finish;
+    }
+
+    if (!(action = polkit_action_new())) {
+        pa_log_error("Cannot allocate PolKitAction.");
+        goto finish;
+    }
+
+    if (!polkit_action_set_action_id(action, action_id)) {
+        pa_log_error("Cannot set action_id");
+        goto finish;
+    }
+
+    if (!(context = polkit_context_new())) {
+        pa_log_error("Cannot allocate PolKitContext.");
+        goto finish;
+    }
+
+    if (!polkit_context_init(context, &polkit_error)) {
+        pa_log_error("Cannot initialize PolKitContext: %s", polkit_error_get_error_message(polkit_error));
+        goto finish;
+    }
+
+    for (;;) {
+
+#ifdef HAVE_POLKIT_CONTEXT_IS_CALLER_AUTHORIZED
+        polkit_result = polkit_context_is_caller_authorized(context, action, caller, TRUE, &polkit_error);
+
+        if (polkit_error_is_set(polkit_error)) {
+            pa_log_error("Could not determine whether caller is authorized: %s", polkit_error_get_error_message(polkit_error));
+            goto finish;
+        }
+#else
+
+        polkit_result = polkit_context_can_caller_do_action(context, action, caller);
+
+#endif
+
+        if (polkit_result == POLKIT_RESULT_ONLY_VIA_ADMIN_AUTH ||
+            polkit_result == POLKIT_RESULT_ONLY_VIA_ADMIN_AUTH_KEEP_SESSION ||
+            polkit_result == POLKIT_RESULT_ONLY_VIA_ADMIN_AUTH_KEEP_ALWAYS ||
+#ifdef POLKIT_RESULT_ONLY_VIA_ADMIN_AUTH_ONE_SHOT
+            polkit_result == POLKIT_RESULT_ONLY_VIA_ADMIN_AUTH_ONE_SHOT ||
+#endif
+            polkit_result == POLKIT_RESULT_ONLY_VIA_SELF_AUTH ||
+            polkit_result == POLKIT_RESULT_ONLY_VIA_SELF_AUTH_KEEP_SESSION ||
+            polkit_result == POLKIT_RESULT_ONLY_VIA_SELF_AUTH_KEEP_ALWAYS
+#ifdef POLKIT_RESULT_ONLY_VIA_SELF_AUTH_ONE_SHOT
+            || polkit_result == POLKIT_RESULT_ONLY_VIA_SELF_AUTH_ONE_SHOT
+#endif
+        ) {
+
+            if (show_grant_dialog(action_id))
+                continue;
+        }
+
+        break;
+    }
+
+    if (polkit_result != POLKIT_RESULT_YES && polkit_result != POLKIT_RESULT_NO)
+        pa_log_warn("PolicyKit responded with '%s'", polkit_result_to_string_representation(polkit_result));
+
+    ret = polkit_result == POLKIT_RESULT_YES;
+
+finish:
+
+    if (caller)
+        polkit_caller_unref(caller);
+
+    if (action)
+        polkit_action_unref(action);
+
+    if (context)
+        polkit_context_unref(context);
+
+    if (bus)
+        dbus_connection_unref(bus);
+
+    dbus_error_free(&dbus_error);
+
+    if (polkit_error)
+        polkit_error_free(polkit_error);
+
+    return ret;
+}

src/daemon/polkit.h

@@ -0,0 +1,29 @@
+#ifndef foopolkithfoo
+#define foopolkithfoo
+
+/* $Id$ */
+
+/***
+  This file is part of PulseAudio.
+
+  Copyright 2007 Lennart Poettering
+
+  PulseAudio is free software; you can redistribute it and/or modify
+  it under the terms of the GNU Lesser General Public License as published
+  by the Free Software Foundation; either version 2 of the License,
+  or (at your option) any later version.
+
+  PulseAudio 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 Lesser General Public License
+  along with PulseAudio; if not, write to the Free Software
+  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
+  USA.
+***/
+
+int pa_polkit_check(const char *action);
+
+#endif