From b80120c4cba7d134b5437a58437a23fdf7ab2084 Mon Sep 17 00:00:00 2001 From: David Herrmann Date: Tue, 7 Jul 2015 19:38:41 +0200 Subject: logind: fail on CreateSession if already in session Right now, if you're already in a session and call CreateSession, we return information about the current session of yours. This is highy confusing and a nasty hack. Avoid that, and instead return a commonly known error, so the caller can detect that. This has the side-effect, that we no longer override XDG_VTNR and XDG_SEAT in pam_systemd, if you're already in a session. But this sounds like the right thing to do, anyway. --- src/login/logind-dbus.c | 69 ++++++++++++------------------------------------- 1 file changed, 17 insertions(+), 52 deletions(-) (limited to 'src/login/logind-dbus.c') diff --git a/src/login/logind-dbus.c b/src/login/logind-dbus.c index c92761f435..82654ee8c7 100644 --- a/src/login/logind-dbus.c +++ b/src/login/logind-dbus.c @@ -689,58 +689,23 @@ static int method_create_session(sd_bus_message *message, void *userdata, sd_bus return r; } - manager_get_session_by_pid(m, leader, &session); - if (!session && vtnr > 0 && vtnr < m->seat0->position_count) { - session = m->seat0->positions[vtnr]; - /* - * Old gdm and lightdm start the user-session on the same VT as - * the greeter session. But they destroy the greeter session - * after the user-session and want the user-session to take - * over the VT. We need to support this for - * backwards-compatibility, so make sure we allow new sessions - * on a VT that a greeter is running on. - */ - if (session && session->class == SESSION_GREETER) - session = NULL; - } - if (session) { - _cleanup_free_ char *path = NULL; - _cleanup_close_ int fifo_fd = -1; - - /* Session already exists, client is probably - * something like "su" which changes uid but is still - * the same session */ - - fifo_fd = session_create_fifo(session); - if (fifo_fd < 0) - return fifo_fd; - - path = session_bus_path(session); - if (!path) - return -ENOMEM; - - log_debug("Sending reply about an existing session: " - "id=%s object_path=%s uid=%u runtime_path=%s " - "session_fd=%d seat=%s vtnr=%u", - session->id, - path, - (uint32_t) session->user->uid, - session->user->runtime_path, - fifo_fd, - session->seat ? session->seat->id : "", - (uint32_t) session->vtnr); - - return sd_bus_reply_method_return( - message, "soshusub", - session->id, - path, - session->user->runtime_path, - fifo_fd, - (uint32_t) session->user->uid, - session->seat ? session->seat->id : "", - (uint32_t) session->vtnr, - true); - } + r = manager_get_session_by_pid(m, leader, NULL); + if (r > 0) + return sd_bus_error_setf(error, BUS_ERROR_SESSION_BUSY, "Already running in a session"); + + /* + * Old gdm and lightdm start the user-session on the same VT as + * the greeter session. But they destroy the greeter session + * after the user-session and want the user-session to take + * over the VT. We need to support this for + * backwards-compatibility, so make sure we allow new sessions + * on a VT that a greeter is running on. + */ + if (vtnr > 0 && + vtnr < m->seat0->position_count && + m->seat0->positions[vtnr] && + m->seat0->positions[vtnr]->class != SESSION_GREETER) + return sd_bus_error_setf(error, BUS_ERROR_SESSION_BUSY, "Already occupied by a session"); audit_session_from_pid(leader, &audit_id); if (audit_id > 0) { -- cgit v1.2.3-54-g00ecf