code.delx.au - pulseaudio/blob - src/daemon/polkit.c

   1 /***
   2   This file is part of PulseAudio.
   3
   4   Copyright 2004-2006 Lennart Poettering
   5   Copyright 2006 Pierre Ossman <ossman@cendio.se> for Cendio AB
   6
   7   PulseAudio is free software; you can redistribute it and/or modify
   8   it under the terms of the GNU Lesser General Public License as published
   9   by the Free Software Foundation; either version 2 of the License,
  10   or (at your option) any later version.
  11
  12   PulseAudio is distributed in the hope that it will be useful, but
  13   WITHOUT ANY WARRANTY; without even the implied warranty of
  14   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  15   General Public License for more details.
  16
  17   You should have received a copy of the GNU Lesser General Public License
  18   along with PulseAudio; if not, write to the Free Software
  19   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  20   USA.
  21 ***/
  22
  23 #ifdef HAVE_CONFIG_H
  24 #include <config.h>
  25 #endif
  26
  27 #include <unistd.h>
  28 #include <stdlib.h>
  29 #include <inttypes.h>
  30
  31 #include <dbus/dbus.h>
  32 #include <polkit-dbus/polkit-dbus.h>
  33
  34 #include <pulse/i18n.h>
  35
  36 #include <pulsecore/log.h>
  37 #include <pulsecore/macro.h>
  38
  39 #include "polkit.h"
  40
  41 int pa_polkit_check(const char *action_id) {
  42     int ret = -1;
  43     DBusError dbus_error;
  44     DBusConnection *bus = NULL;
  45     PolKitCaller *caller = NULL;
  46     PolKitAction *action = NULL;
  47     PolKitContext *context = NULL;
  48     PolKitError *polkit_error = NULL;
  49     PolKitSession *session = NULL;
  50     PolKitResult polkit_result;
  51
  52     dbus_error_init(&dbus_error);
  53
  54     if (!(bus = dbus_bus_get(DBUS_BUS_SYSTEM, &dbus_error))) {
  55         pa_log_error(_("Cannot connect to system bus: %s"), dbus_error.message);
  56         goto finish;
  57     }
  58
  59     /* There seems to be a bug in some versions of D-Bus that causes
  60      * dbus_shutdown() to call exit() when a connection without this
  61      * flag disabled was created during runtime.*/
  62     dbus_connection_set_exit_on_disconnect(bus, FALSE);
  63
  64     if (!(caller = polkit_caller_new_from_pid(bus, getpid(), &dbus_error))) {
  65         pa_log_error(_("Cannot get caller from PID: %s"), dbus_error.message);
  66         goto finish;
  67     }
  68
  69     /* This function is called when PulseAudio is called SUID root. We
  70      * want to authenticate the real user that called us and not the
  71      * effective user we gained through being SUID root. Hence we
  72      * overwrite the UID caller data here explicitly, just for
  73      * paranoia. In fact PolicyKit should fill in the UID here anyway
  74      * -- an not the EUID or any other user id. */
  75
  76     if (!(polkit_caller_set_uid(caller, getuid()))) {
  77         pa_log_error(_("Cannot set UID on caller object."));
  78         goto finish;
  79     }
  80
  81     if (!(polkit_caller_get_ck_session(caller, &session))) {
  82         pa_log_error(_("Failed to get CK session."));
  83         goto finish;
  84     }
  85
  86     /* We need to overwrite the UID in both the caller and the session
  87      * object */
  88
  89     if (!(polkit_session_set_uid(session, getuid()))) {
  90         pa_log_error(_("Cannot set UID on session object."));
  91         goto finish;
  92     }
  93
  94     if (!(action = polkit_action_new())) {
  95         pa_log_error(_("Cannot allocate PolKitAction."));
  96         goto finish;
  97     }
  98
  99     if (!polkit_action_set_action_id(action, action_id)) {
 100         pa_log_error(_("Cannot set action_id"));
 101         goto finish;
 102     }
 103
 104     if (!(context = polkit_context_new())) {
 105         pa_log_error(_("Cannot allocate PolKitContext."));
 106         goto finish;
 107     }
 108
 109     if (!polkit_context_init(context, &polkit_error)) {
 110         pa_log_error(_("Cannot initialize PolKitContext: %s"), polkit_error_get_error_message(polkit_error));
 111         goto finish;
 112     }
 113
 114     for (;;) {
 115
 116         polkit_result = polkit_context_is_caller_authorized(context, action, caller, TRUE, &polkit_error);
 117
 118         if (polkit_error_is_set(polkit_error)) {
 119             pa_log_error(_("Could not determine whether caller is authorized: %s"), polkit_error_get_error_message(polkit_error));
 120             goto finish;
 121         }
 122
 123         if (polkit_result == POLKIT_RESULT_ONLY_VIA_ADMIN_AUTH ||
 124             polkit_result == POLKIT_RESULT_ONLY_VIA_ADMIN_AUTH_KEEP_SESSION ||
 125             polkit_result == POLKIT_RESULT_ONLY_VIA_ADMIN_AUTH_KEEP_ALWAYS ||
 126             polkit_result == POLKIT_RESULT_ONLY_VIA_ADMIN_AUTH_ONE_SHOT ||
 127             polkit_result == POLKIT_RESULT_ONLY_VIA_SELF_AUTH ||
 128             polkit_result == POLKIT_RESULT_ONLY_VIA_SELF_AUTH_KEEP_SESSION ||
 129             polkit_result == POLKIT_RESULT_ONLY_VIA_SELF_AUTH_KEEP_ALWAYS ||
 130             polkit_result == POLKIT_RESULT_ONLY_VIA_SELF_AUTH_ONE_SHOT
 131         ) {
 132
 133             if (polkit_auth_obtain(action_id, 0, getpid(), &dbus_error)) {
 134                 polkit_result = POLKIT_RESULT_YES;
 135                 break;
 136             }
 137
 138             if (dbus_error_is_set(&dbus_error)) {
 139                 pa_log_error(_("Cannot obtain auth: %s"), dbus_error.message);
 140                 goto finish;
 141             }
 142         }
 143
 144         break;
 145     }
 146
 147     if (polkit_result != POLKIT_RESULT_YES && polkit_result != POLKIT_RESULT_NO)
 148         pa_log_warn(_("PolicyKit responded with '%s'"), polkit_result_to_string_representation(polkit_result));
 149
 150     ret = polkit_result == POLKIT_RESULT_YES;
 151
 152 finish:
 153
 154     if (caller)
 155         polkit_caller_unref(caller);
 156
 157     if (action)
 158         polkit_action_unref(action);
 159
 160     if (context)
 161         polkit_context_unref(context);
 162
 163     if (bus)
 164         dbus_connection_unref(bus);
 165
 166     dbus_error_free(&dbus_error);
 167
 168     if (polkit_error)
 169         polkit_error_free(polkit_error);
 170
 171     return ret;
 172 }