sock: ignore SCM_RIGHTS and SCM_CREDENTIALS in __sock_cmsg_send
Sergei Trofimovich reported that pulse audio sends SCM_CREDENTIALS
as a control message to TCP. Since __sock_cmsg_send does not
support SCM_RIGHTS and SCM_CREDENTIALS, it returns an error and
hence breaks pulse audio over TCP.
SCM_RIGHTS and SCM_CREDENTIALS are sent on the SOL_SOCKET layer
but they semantically belong to SOL_UNIX. Since all
cmsg-processing functions including sock_cmsg_send ignore control
messages of other layers, it is best to ignore SCM_RIGHTS
and SCM_CREDENTIALS for consistency (and also for fixing pulse
audio over TCP).
Fixes: c14ac9451c34 ("sock: enable timestamping using control messages") Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com> Reported-by: Sergei Trofimovich <slyfox@gentoo.org> Tested-by: Sergei Trofimovich <slyfox@gentoo.org> Cc: Eric Dumazet <edumazet@google.com> Cc: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>