/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ /*** This file is part of systemd. Copyright 2010 Lennart Poettering systemd 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. systemd 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 systemd; If not, see <http://www.gnu.org/licenses/>. ***/ #include <assert.h> #include <sys/socket.h> #include <errno.h> #include <unistd.h> #include <dbus/dbus.h> #include "log.h" #include "dbus-common.h" int bus_check_peercred(DBusConnection *c) { int fd; struct ucred ucred; socklen_t l; assert(c); assert_se(dbus_connection_get_unix_fd(c, &fd)); l = sizeof(struct ucred); if (getsockopt(fd, SOL_SOCKET, SO_PEERCRED, &ucred, &l) < 0) { log_error("SO_PEERCRED failed: %m"); return -errno; } if (l != sizeof(struct ucred)) { log_error("SO_PEERCRED returned wrong size."); return -E2BIG; } if (ucred.uid != 0) return -EPERM; return 1; } int bus_connect(DBusBusType t, DBusConnection **_bus, bool *private, DBusError *error) { DBusConnection *bus; assert(_bus); /* If we are root, then let's not go via the bus */ if (geteuid() == 0 && t == DBUS_BUS_SYSTEM) { if (!(bus = dbus_connection_open_private("unix:abstract=/org/freedesktop/systemd1/private", error))) return -EIO; if (bus_check_peercred(bus) < 0) { dbus_connection_unref(bus); dbus_set_error_const(error, DBUS_ERROR_ACCESS_DENIED, "Failed to verify owner of bus."); return -EACCES; } if (private) *private = true; } else { if (!(bus = dbus_bus_get_private(t, error))) return -EIO; if (private) *private = false; } dbus_connection_set_exit_on_disconnect(bus, FALSE); *_bus = bus; return 0; } const char *bus_error_message(const DBusError *error) { assert(error); /* Sometimes the D-Bus server is a little bit too verbose with * its error messages, so let's override them here */ if (dbus_error_has_name(error, DBUS_ERROR_ACCESS_DENIED)) return "Access denied"; return error->message; }