From: Lennart Poettering Date: Tue, 5 Mar 2013 02:29:54 +0000 (+0100) Subject: logind: when registering a new session always use previous session info from cgroup... X-Git-Tag: v198~82 X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=commitdiff_plain;h=954449b82df7fc2d37a8d854977a1a73a65edfbd logind: when registering a new session always use previous session info from cgroup path rather than audit Previously for cases like "su" or "sudo" where a session is attempted to be created from within an existing one we used the audit session ID to detect this and in such a case we simple returned the session data of the original session a second time. With this change we will now use the cgroup path of the calling path to determine the old session, i.e. we only rely on our own session identification scheme, instead of audits. We will continue to keep the audit session ID and ours in sync however, to avoid unnecessary confusion. --- diff --git a/src/login/logind-dbus.c b/src/login/logind-dbus.c index 818f2fa80..1dcdf04b2 100644 --- a/src/login/logind-dbus.c +++ b/src/login/logind-dbus.c @@ -308,21 +308,21 @@ static int bus_manager_append_preparing(DBusMessageIter *i, const char *property } static int bus_manager_create_session(Manager *m, DBusMessage *message, DBusMessage **_reply) { - Session *session = NULL; - User *user = NULL; - const char *type, *class, *seat, *tty, *display, *remote_user, *remote_host, *service; + const char *type, *class, *cseat, *tty, *display, *remote_user, *remote_host, *service; uint32_t uid, leader, audit_id = 0; dbus_bool_t remote, kill_processes, exists; - char **controllers = NULL, **reset_controllers = NULL; + _cleanup_strv_free_ char **controllers = NULL, **reset_controllers = NULL; + _cleanup_free_ char *cgroup = NULL, *id = NULL, *p = NULL; SessionType t; SessionClass c; - Seat *s; DBusMessageIter iter; int r; - char *id = NULL, *p; uint32_t vtnr = 0; - int fifo_fd = -1; + _cleanup_close_ int fifo_fd = -1; DBusMessage *reply = NULL; + Session *session = NULL; + User *user = NULL; + Seat *seat = NULL; bool b; assert(m); @@ -371,13 +371,13 @@ static int bus_manager_create_session(Manager *m, DBusMessage *message, DBusMess dbus_message_iter_get_arg_type(&iter) != DBUS_TYPE_STRING) return -EINVAL; - dbus_message_iter_get_basic(&iter, &seat); + dbus_message_iter_get_basic(&iter, &cseat); - if (isempty(seat)) - s = NULL; + if (isempty(cseat)) + seat = NULL; else { - s = hashmap_get(m->seats, seat); - if (!s) + seat = hashmap_get(m->seats, cseat); + if (!seat) return -ENOENT; } @@ -396,9 +396,9 @@ static int bus_manager_create_session(Manager *m, DBusMessage *message, DBusMess if (tty_is_vc(tty)) { int v; - if (!s) - s = m->vtconsole; - else if (s != m->vtconsole) + if (!seat) + seat = m->vtconsole; + else if (seat != m->vtconsole) return -EINVAL; v = vtnr_from_tty(tty); @@ -412,18 +412,17 @@ static int bus_manager_create_session(Manager *m, DBusMessage *message, DBusMess return -EINVAL; } else if (tty_is_console(tty)) { - if (!s) - s = m->vtconsole; - else if (s != m->vtconsole) + if (!seat) + seat = m->vtconsole; + else if (seat != m->vtconsole) return -EINVAL; if (vtnr != 0) return -EINVAL; - } - if (s) { - if (seat_can_multi_session(s)) { + if (seat) { + if (seat_can_multi_session(seat)) { if (vtnr > 63) return -EINVAL; } else { @@ -486,78 +485,83 @@ static int bus_manager_create_session(Manager *m, DBusMessage *message, DBusMess dbus_message_iter_get_basic(&iter, &kill_processes); - r = manager_add_user_by_uid(m, uid, &user); + r = cg_pid_get_cgroup(leader, NULL, &cgroup); if (r < 0) goto fail; - audit_session_from_pid(leader, &audit_id); - - if (audit_id > 0) { - asprintf(&id, "%lu", (unsigned long) audit_id); + r = manager_get_session_by_cgroup(m, cgroup, &session); + if (r < 0) + goto fail; - if (!id) { - r = -ENOMEM; + if (session) { + fifo_fd = session_create_fifo(session); + if (fifo_fd < 0) { + r = fifo_fd; goto fail; } - session = hashmap_get(m->sessions, id); + /* Session already exists, client is probably + * something like "su" which changes uid but + * is still the same audit session */ - if (session) { - free(id); + reply = dbus_message_new_method_return(message); + if (!reply) { + r = -ENOMEM; + goto fail; + } - fifo_fd = session_create_fifo(session); - if (fifo_fd < 0) { - r = fifo_fd; - goto fail; - } + p = session_bus_path(session); + if (!p) { + r = -ENOMEM; + goto fail; + } - /* Session already exists, client is probably - * something like "su" which changes uid but - * is still the same audit session */ + cseat = session->seat ? session->seat->id : ""; + vtnr = session->vtnr; + exists = true; - reply = dbus_message_new_method_return(message); - if (!reply) { - r = -ENOMEM; - goto fail; - } + b = dbus_message_append_args( + reply, + DBUS_TYPE_STRING, &session->id, + DBUS_TYPE_OBJECT_PATH, &p, + DBUS_TYPE_STRING, &session->user->runtime_path, + DBUS_TYPE_UNIX_FD, &fifo_fd, + DBUS_TYPE_STRING, &cseat, + DBUS_TYPE_UINT32, &vtnr, + DBUS_TYPE_BOOLEAN, &exists, + DBUS_TYPE_INVALID); + if (!b) { + r = -ENOMEM; + goto fail; + } - p = session_bus_path(session); - if (!p) { - r = -ENOMEM; - goto fail; - } + *_reply = reply; - seat = session->seat ? session->seat->id : ""; - vtnr = session->vtnr; - exists = true; - - b = dbus_message_append_args( - reply, - DBUS_TYPE_STRING, &session->id, - DBUS_TYPE_OBJECT_PATH, &p, - DBUS_TYPE_STRING, &session->user->runtime_path, - DBUS_TYPE_UNIX_FD, &fifo_fd, - DBUS_TYPE_STRING, &seat, - DBUS_TYPE_UINT32, &vtnr, - DBUS_TYPE_BOOLEAN, &exists, - DBUS_TYPE_INVALID); - free(p); + return 0; + } - if (!b) { - r = -ENOMEM; - goto fail; - } + audit_session_from_pid(leader, &audit_id); + if (audit_id > 0) { + /* Keep our session IDs and the audit session IDs in sync */ - close_nointr_nofail(fifo_fd); - *_reply = reply; + if (asprintf(&id, "%lu", (unsigned long) audit_id) < 0) { + r = -ENOMEM; + goto fail; + } - strv_free(controllers); - strv_free(reset_controllers); + /* Wut? There's already a session by this name and we + * didn't find it above? Weird, then let's not trust + * the audit data and let's better register a new + * ID */ + if (hashmap_get(m->sessions, id)) { + audit_id = 0; - return 0; + free(id); + id = NULL; } + } - } else { + if (!id) { do { free(id); id = NULL; @@ -570,8 +574,11 @@ static int bus_manager_create_session(Manager *m, DBusMessage *message, DBusMess } while (hashmap_get(m->sessions, id)); } + r = manager_add_user_by_uid(m, uid, &user); + if (r < 0) + goto fail; + r = manager_add_session(m, user, id, &session); - free(id); if (r < 0) goto fail; @@ -633,8 +640,8 @@ static int bus_manager_create_session(Manager *m, DBusMessage *message, DBusMess goto fail; } - if (s) { - r = seat_attach_session(s, session); + if (seat) { + r = seat_attach_session(seat, session); if (r < 0) goto fail; } @@ -655,7 +662,7 @@ static int bus_manager_create_session(Manager *m, DBusMessage *message, DBusMess goto fail; } - seat = s ? s->id : ""; + cseat = seat ? seat->id : ""; exists = false; b = dbus_message_append_args( reply, @@ -663,35 +670,27 @@ static int bus_manager_create_session(Manager *m, DBusMessage *message, DBusMess DBUS_TYPE_OBJECT_PATH, &p, DBUS_TYPE_STRING, &session->user->runtime_path, DBUS_TYPE_UNIX_FD, &fifo_fd, - DBUS_TYPE_STRING, &seat, + DBUS_TYPE_STRING, &cseat, DBUS_TYPE_UINT32, &vtnr, DBUS_TYPE_BOOLEAN, &exists, DBUS_TYPE_INVALID); - free(p); if (!b) { r = -ENOMEM; goto fail; } - close_nointr_nofail(fifo_fd); *_reply = reply; return 0; fail: - strv_free(controllers); - strv_free(reset_controllers); - if (session) session_add_to_gc_queue(session); if (user) user_add_to_gc_queue(user); - if (fifo_fd >= 0) - close_nointr_nofail(fifo_fd); - if (reply) dbus_message_unref(reply);