Re: [RFC mptcp-next v5 4/8] mptcp: enable TLS setsockopt

[Matthieu Baerts <matttbe@kernel.org>]

Hi Geliang,

On 22/12/2025 04:15, Geliang Tang wrote:
> From: Geliang Tang <tanggeliang@kylinos.cn>
> 
> This patch adds MPTCP TLS setsockopt support. It allows setting the TCP_ULP
> option to 'tls' exclusively, and enables configuration of the TLS_TX and
> TLS_RX options at the SOL_TLS level.
> 
> This option cannot be set when the socket is in CLOSE or LISTEN state.

(...)

> @@ -819,11 +828,18 @@ static int mptcp_setsockopt_sol_tcp(struct mptcp_sock *msk, int optname,
>  				    sockptr_t optval, unsigned int optlen)
>  {
>  	struct sock *sk = (void *)msk;
> +	char ulp[4] = "";
>  	int ret, val;
>  
>  	switch (optname) {
>  	case TCP_ULP:
> -		return -EOPNOTSUPP;
> +		if (copy_from_user(ulp, optval.user, 4))
> +			return -EFAULT;
> +		if (strcmp(ulp, "tls\0"))
> +			return -EOPNOTSUPP;
> +		if ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))
> +			return -ENOTCONN;

This is specific to TLS, maybe better to move that to a new setsockopt
ULP helper?

> +		return tcp_setsockopt(sk, SOL_TCP, optname, optval, optlen);

Same as in the previous patch, better not to call ...

  tcp_[gs]etsockopt(msk, SOL_TCP, ...)

... directly.

>  	case TCP_CONGESTION:
>  		return mptcp_setsockopt_sol_tcp_congestion(msk, optval, optlen);
>  	case TCP_DEFER_ACCEPT:

Cheers,
Matt
-- 
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