kdbus.txt: fixes

Fix issues spotted by Greg.

Signed-off-by: Daniel Mack <daniel@zonque.org>
kdbus.txt: fix things spotted by Alban Crequy

Signed-off-by: Daniel Mack <daniel@zonque.org>
test-fd: ensure that broadcasting fds and memfds will fail with -ENOTUNIQ

Signed-off-by: Djalal Harouni <tixxdz@opendz.org>
test: test monitor connections for broadcast messages

Signed-off-by: Djalal Harouni <tixxdz@opendz.org>
test-sync: ensure sync is interruptible and it ignors SA_RESTART flag

Signed-off-by: Djalal Harouni <tixxdz@opendz.org>
doc: KDBUS_MSG_FLAGS_SYNC_REPLY can be interrupted by a signal delivery

Signed-off-by: Djalal Harouni <tixxdz@opendz.org>
tests: strncpy() corrections

Use the correct maximum size with strncpy(), even though we're using
small static strings as sources.

Signed-off-by: Daniel Mack <daniel@zonque.org>
kdbus.h: add KDBUS_HELLO_ACCEPT_MEMFD (ABI break)

Add another flags to the connection's flags to denote whether it
want to receive memfds. Reject messages with -ECOMM if it contains
a memfd if the receiver can't cope with it.

Signed-off-by: Daniel Mack <daniel@zonque.org>
test-util: move RUN_UNPRIVILEGED definitions to kdbus-util.h

Will be used by other tests

Signed-off-by: Djalal Harouni <tixxdz@opendz.org>
test-util: add test_is_capable() to check for capabilities and use it

Signed-off-by: Djalal Harouni <tixxdz@opendz.org>
test-activator: add more tests for the activation logic

Signed-off-by: Djalal Harouni <tixxdz@opendz.org>
connection: use KDBUS_HELLO_ACCEPT_MEMFD to check for passed memfds

Signed-off-by: Djalal Harouni <tixxdz@opendz.org>
doc: document the new KDBUS_HELLO_ACCEPT_MEMFD flag

Signed-off-by: Djalal Harouni <tixxdz@opendz.org>