[systemd-commits] src/bus-proxyd

[David Herrmann]

 src/bus-proxyd/bus-proxyd.c |   12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

New commits:
commit b5cfc2b953fca74bf4c42a4e9e38abe72cc26493
Author: David Herrmann <dh.herrmann at gmail.com>
Date:   Sun Jan 11 15:14:14 2015 +0100

    bus-proxy: fix receiver policy on dbus-1 to kdbus signals
    
    If a dbus-1 client sends a broadcasted signal via the bus-proxy to kdbus,
    the bus-proxy has no idea who the receiver is. Classic dbus-daemon has
    bus-access and can perform policy checks for each receiver, but we cant.
    Instead, we know the kernel will perform receiver policy checks for
    broadcasts, so we can skip the policy check and just push it into the
    kernel.
    
    This fixes wpa_supplicant which has DENY rules on receive_type=signal for
    non-root. As we never know the target, we always DENY all broadcasts from
    wpa_supplicant.
    
    Note that will still perform receiver-policy checks for signals that we
    get from the kernel back to us. In those cases, we know the receiver
    (which is us).

diff --git a/src/bus-proxyd/bus-proxyd.c b/src/bus-proxyd/bus-proxyd.c
index 3cbbab7..2b32865 100644
--- a/src/bus-proxyd/bus-proxyd.c
+++ b/src/bus-proxyd/bus-proxyd.c
@@ -1148,7 +1148,17 @@ static int process_policy(sd_bus *from, sd_bus *to, sd_bus_message *m, Policy *p
 
                 /* Then check if the recipient can receive from our name */
                 if (granted) {
-                        if (set_isempty(owned_names)) {
+                        if (sd_bus_message_is_signal(m, NULL, NULL)) {
+                                /* If we forward a signal from dbus-1 to kdbus,
+                                 * we have no idea who the recipient is.
+                                 * Therefore, we cannot apply any dbus-1
+                                 * receiver policies that match on receiver
+                                 * credentials. We know sd-bus always sets
+                                 * KDBUS_MSG_SIGNAL, so the kernel applies
+                                 * receiver policies to the message. Therefore,
+                                 * skip policy checks in this case. */
+                                return 0;
+                        } else if (set_isempty(owned_names)) {
                                 if (policy_check_recv(policy, destination_uid, destination_gid, m->header->type, NULL, m->path, m->interface, m->member))
                                         return 0;
                         } else {