Re: [PATCH mptcp-next] mptcp: sockopt: use new helper for TCP_DEFER_ACCEPT

[Mat Martineau <mathew.j.martineau@linux.intel.com>]

On Wed, 28 Sep 2022, Matthieu Baerts wrote:

> mptcp_setsockopt_sol_tcp_defer() was doing the same thing as
> mptcp_setsockopt_first_sf_only() except for the returned code in case of
> error.
>
> Ignoring the error is needed to mimic how TCP_DEFER_ACCEPT is handled
> when used with "plain" TCP sockets.
>
> The specific function for TCP_DEFER_ACCEPT can be replaced by the new
> mptcp_setsockopt_first_sf_only() helper and errors can be ignored to
> stay compatible with TCP. A bit of cleanup.
>
> Suggested-by: Paolo Abeni <pabeni@redhat.com>
> Suggested-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>

Looks good to me, thanks!

Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>

> ---
> net/mptcp/sockopt.c | 16 +++-------------
> 1 file changed, 3 insertions(+), 13 deletions(-)
>
> diff --git a/net/mptcp/sockopt.c b/net/mptcp/sockopt.c
> index 1857281a0dd5..f85e9bbfe86f 100644
> --- a/net/mptcp/sockopt.c
> +++ b/net/mptcp/sockopt.c
> @@ -758,18 +758,6 @@ static int mptcp_setsockopt_v4(struct mptcp_sock *msk, int optname,
> 	return -EOPNOTSUPP;
> }
>
> -static int mptcp_setsockopt_sol_tcp_defer(struct mptcp_sock *msk, sockptr_t optval,
> -					  unsigned int optlen)
> -{
> -	struct socket *listener;
> -
> -	listener = __mptcp_nmpc_socket(msk);
> -	if (!listener)
> -		return 0; /* TCP_DEFER_ACCEPT does not fail */
> -
> -	return tcp_setsockopt(listener->sk, SOL_TCP, TCP_DEFER_ACCEPT, optval, optlen);
> -}
> -
> static int mptcp_setsockopt_first_sf_only(struct mptcp_sock *msk, int level, int optname,
> 					  sockptr_t optval, unsigned int optlen)
> {
> @@ -810,7 +798,9 @@ static int mptcp_setsockopt_sol_tcp(struct mptcp_sock *msk, int optname,
> 	case TCP_NODELAY:
> 		return mptcp_setsockopt_sol_tcp_nodelay(msk, optval, optlen);
> 	case TCP_DEFER_ACCEPT:
> -		return mptcp_setsockopt_sol_tcp_defer(msk, optval, optlen);
> +		/* See tcp.c: TCP_DEFER_ACCEPT does not fail */
> +		mptcp_setsockopt_first_sf_only(msk, SOL_TCP, optname, optval, optlen);
> +		return 0;
> 	case TCP_FASTOPEN_CONNECT:
> 	case TCP_FASTOPEN_NO_COOKIE:
> 		return mptcp_setsockopt_first_sf_only(msk, SOL_TCP, optname,
>
> base-commit: 6711fbb5e6c8541f84685542127455c18145d559
> -- 
> 2.37.2
>
>

--
Mat Martineau
Intel