From def9a7aa0182e5ecca3ac61b26f75136a5c4f103 Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Fri, 15 Aug 2014 20:08:51 +0200 Subject: sd-bus: add API to check if a client has privileges This is a generalization of the vtable privilege check we already have, but exported, and hence useful when preparing for a polkit change. This will deal with the complexity that on dbus1 one cannot trust the capability field we retrieve via the bus, since it is read via /proc/$$/stat (and thus might be out-of-date) rather than directly from the message (like on kdbus) or bus connection (as for uid creds on dbus1). Also, port over all code to this new API. --- src/libsystemd/sd-bus/bus-objects.c | 25 ++++--------------------- 1 file changed, 4 insertions(+), 21 deletions(-) (limited to 'src/libsystemd/sd-bus/bus-objects.c') diff --git a/src/libsystemd/sd-bus/bus-objects.c b/src/libsystemd/sd-bus/bus-objects.c index dbb04e5ec6..78dab8048d 100644 --- a/src/libsystemd/sd-bus/bus-objects.c +++ b/src/libsystemd/sd-bus/bus-objects.c @@ -289,7 +289,6 @@ static int node_callbacks_run( static int check_access(sd_bus *bus, sd_bus_message *m, struct vtable_member *c, sd_bus_error *error) { _cleanup_bus_creds_unref_ sd_bus_creds *creds = NULL; uint64_t cap; - uid_t uid; int r; assert(bus); @@ -304,17 +303,6 @@ static int check_access(sd_bus *bus, sd_bus_message *m, struct vtable_member *c, if (c->vtable->flags & SD_BUS_VTABLE_UNPRIVILEGED) return 0; - /* If we are not connected to kdbus we cannot retrieve the - * effective capability set without race. Since we need this - * for a security decision we cannot use racy data, hence - * don't request it. */ - if (bus->is_kernel) - r = sd_bus_query_sender_creds(m, SD_BUS_CREDS_UID|SD_BUS_CREDS_EFFECTIVE_CAPS, &creds); - else - r = sd_bus_query_sender_creds(m, SD_BUS_CREDS_UID, &creds); - if (r < 0) - return r; - /* Check have the caller has the requested capability * set. Note that the flags value contains the capability * number plus one, which we need to subtract here. We do this @@ -328,16 +316,11 @@ static int check_access(sd_bus *bus, sd_bus_message *m, struct vtable_member *c, else cap --; - r = sd_bus_creds_has_effective_cap(creds, cap); + r = sd_bus_query_sender_privilege(m, cap); + if (r < 0) + return r; if (r > 0) - return 1; - - /* Caller has same UID as us, then let's grant access */ - r = sd_bus_creds_get_uid(creds, &uid); - if (r >= 0) { - if (uid == getuid()) - return 1; - } + return 0; return sd_bus_error_setf(error, SD_BUS_ERROR_ACCESS_DENIED, "Access to %s.%s() not permitted.", c->interface, c->member); } -- cgit v1.2.3-54-g00ecf