On Fri, 15 May 2020, Paolo Abeni wrote:
MP_JOIN subflows must not land into the accept queue. Currently tcp_check_req() calls an mptcp specific helper to detect such scenario. Such helper leverages the subflow context to check for MP_JOIN subflows. We need to deal also with MP JOIN failures, even when the subflow context is not available due allocation failure. A possible solution would be changing the syn_recv_sock() signature to allow returning a more descriptive action/ error code and deal with that in tcp_check_req(). Since the above need is MPTCP specific, this patch instead uses a TCP request socket hole to add a MPTCP specific flag. Such flag is used by the MPTCP syn_recv_sock() to tell tcp_check_req() how to deal with the request socket. This change is a no-op for !MPTCP build, and makes the MPTCP code simpler. It allows also the next patch to deal correctly with MP JOIN failure. v1 -> v2: - be more conservative on drop_req initialization (Mat) RFC -> v1: - move the drop_req bit inside tcp_request_sock (Eric) Signed-off-by: Paolo Abeni <pab...@redhat.com> --- include/linux/tcp.h | 3 +++ include/net/mptcp.h | 17 ++++++++++------- net/ipv4/tcp_minisocks.c | 2 +- net/mptcp/protocol.c | 7 ------- net/mptcp/subflow.c | 3 +++ 5 files changed, 17 insertions(+), 15 deletions(-)
Thanks for the initialization fix, patch looks good. Reviewed-by: Mat Martineau <mathew.j.martin...@linux.intel.com> -- Mat Martineau Intel
