Commit f284c0c7 authored by Paolo Abeni's avatar Paolo Abeni Committed by David S. Miller
Browse files

mptcp: implement fastclose xmit path 



Allow the MPTCP xmit path to add MP_FASTCLOSE suboption
on RST egress packets.

Additionally reorder related options writing to reduce
the number of conditionals required in the fast path.

Co-developed-by: default avatarGeliang Tang <geliang.tang@suse.com>
Signed-off-by: default avatarGeliang Tang <geliang.tang@suse.com>
Co-developed-by: default avatarMatthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: default avatarMatthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
Signed-off-by: default avatarMat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 58cd405b

net/mptcp/options.c

+45 −12
Original line number Diff line number Diff line
@@ -768,6 +768,28 @@ static noinline bool mptcp_established_options_rst(struct sock *sk, struct sk_bu 
	return true;

}



static bool mptcp_established_options_fastclose(struct sock *sk,

						unsigned int *size,

						unsigned int remaining,

						struct mptcp_out_options *opts)

{

	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);

	struct mptcp_sock *msk = mptcp_sk(subflow->conn);



	if (likely(!subflow->send_fastclose))

		return false;



	if (remaining < TCPOLEN_MPTCP_FASTCLOSE)

		return false;



	*size = TCPOLEN_MPTCP_FASTCLOSE;

	opts->suboptions |= OPTION_MPTCP_FASTCLOSE;

	opts->rcvr_key = msk->remote_key;



	pr_debug("FASTCLOSE key=%llu", opts->rcvr_key);

	return true;

}



static bool mptcp_established_options_mp_fail(struct sock *sk,

					      unsigned int *size,

					      unsigned int remaining,
@@ -806,10 +828,12 @@ bool mptcp_established_options(struct sock *sk, struct sk_buff *skb, 
		return false;



	if (unlikely(skb && TCP_SKB_CB(skb)->tcp_flags & TCPHDR_RST)) {

		if (mptcp_established_options_mp_fail(sk, &opt_size, remaining, opts)) {

		if (mptcp_established_options_fastclose(sk, &opt_size, remaining, opts) ||

		    mptcp_established_options_mp_fail(sk, &opt_size, remaining, opts)) {

			*size += opt_size;

			remaining -= opt_size;

		}

		/* MP_RST can be used with MP_FASTCLOSE and MP_FAIL if there is room */

		if (mptcp_established_options_rst(sk, skb, &opt_size, remaining, opts)) {

			*size += opt_size;

			remaining -= opt_size;
@@ -1251,17 +1275,8 @@ void mptcp_write_options(__be32 *ptr, const struct tcp_sock *tp, 
		ptr += 2;

	}



	/* RST is mutually exclusive with everything else */

	if (unlikely(OPTION_MPTCP_RST & opts->suboptions)) {

		*ptr++ = mptcp_option(MPTCPOPT_RST,

				      TCPOLEN_MPTCP_RST,

				      opts->reset_transient,

				      opts->reset_reason);

		return;

	}



	/* DSS, MPC, MPJ and ADD_ADDR are mutually exclusive, see

	 * mptcp_established_options*()

	/* DSS, MPC, MPJ, ADD_ADDR, FASTCLOSE and RST are mutually exclusive,

	 * see mptcp_established_options*()

	 */

	if (likely(OPTION_MPTCP_DSS & opts->suboptions)) {

		struct mptcp_ext *mpext = &opts->ext_copy;
@@ -1447,6 +1462,24 @@ void mptcp_write_options(__be32 *ptr, const struct tcp_sock *tp, 
				ptr += 1;

			}

		}

	} else if (unlikely(OPTION_MPTCP_FASTCLOSE & opts->suboptions)) {

		/* FASTCLOSE is mutually exclusive with others except RST */

		*ptr++ = mptcp_option(MPTCPOPT_MP_FASTCLOSE,

				      TCPOLEN_MPTCP_FASTCLOSE,

				      0, 0);

		put_unaligned_be64(opts->rcvr_key, ptr);

		ptr += 2;



		if (OPTION_MPTCP_RST & opts->suboptions)

			goto mp_rst;

		return;

	} else if (unlikely(OPTION_MPTCP_RST & opts->suboptions)) {

mp_rst:

		*ptr++ = mptcp_option(MPTCPOPT_RST,

				      TCPOLEN_MPTCP_RST,

				      opts->reset_transient,

				      opts->reset_reason);

		return;

	}



	if (OPTION_MPTCP_PRIO & opts->suboptions) {

net/mptcp/protocol.h

+1 −0
Original line number Diff line number Diff line
@@ -423,6 +423,7 @@ struct mptcp_subflow_context { 
		backup : 1,

		send_mp_prio : 1,

		send_mp_fail : 1,

		send_fastclose : 1,

		rx_eof : 1,

		can_ack : 1,        /* only after processing the remote a key */

		disposable : 1,	    /* ctx can be free at ulp release time */