Commit c25aeb4e authored by Geliang Tang's avatar Geliang Tang Committed by David S. Miller
Browse files

mptcp: MP_FAIL suboption sending 



This patch added the MP_FAIL suboption sending support.

Add a new flag named send_mp_fail in struct mptcp_subflow_context. If
this flag is set, send out MP_FAIL suboption.

Add a new member fail_seq in struct mptcp_out_options to save the data
sequence number to put into the MP_FAIL suboption.

An MP_FAIL option could be included in a RST or on the subflow-level
ACK.

Suggested-by: default avatarPaolo Abeni <pabeni@redhat.com>
Signed-off-by: default avatarGeliang Tang <geliangtang@xiaomi.com>
Signed-off-by: default avatarMat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent d7b26908

include/net/mptcp.h

+4 −1
Original line number Diff line number Diff line
@@ -74,7 +74,10 @@ struct mptcp_out_options { 
			struct mptcp_addr_info addr;

			u64 ahmac;

		};

		struct {

			struct mptcp_ext ext_copy;

			u64 fail_seq;

		};

		struct {

			u32 nonce;

			u32 token;

net/mptcp/options.c

+55 −4
Original line number Diff line number Diff line
@@ -767,7 +767,7 @@ static bool mptcp_established_options_mp_prio(struct sock *sk, 
	return true;

}



static noinline void mptcp_established_options_rst(struct sock *sk, struct sk_buff *skb,

static noinline bool mptcp_established_options_rst(struct sock *sk, struct sk_buff *skb,

						   unsigned int *size,

						   unsigned int remaining,

						   struct mptcp_out_options *opts)
@@ -775,12 +775,36 @@ static noinline void mptcp_established_options_rst(struct sock *sk, struct sk_bu 
	const struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);



	if (remaining < TCPOLEN_MPTCP_RST)

		return;

		return false;



	*size = TCPOLEN_MPTCP_RST;

	opts->suboptions |= OPTION_MPTCP_RST;

	opts->reset_transient = subflow->reset_transient;

	opts->reset_reason = subflow->reset_reason;



	return true;

}



static bool mptcp_established_options_mp_fail(struct sock *sk,

					      unsigned int *size,

					      unsigned int remaining,

					      struct mptcp_out_options *opts)

{

	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);



	if (likely(!subflow->send_mp_fail))

		return false;



	if (remaining < TCPOLEN_MPTCP_FAIL)

		return false;



	*size = TCPOLEN_MPTCP_FAIL;

	opts->suboptions |= OPTION_MPTCP_FAIL;

	opts->fail_seq = subflow->map_seq;



	pr_debug("MP_FAIL fail_seq=%llu", opts->fail_seq);



	return true;

}



bool mptcp_established_options(struct sock *sk, struct sk_buff *skb,
@@ -799,15 +823,28 @@ bool mptcp_established_options(struct sock *sk, struct sk_buff *skb, 
		return false;



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

		mptcp_established_options_rst(sk, skb, size, remaining, opts);

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

			*size += opt_size;

			remaining -= opt_size;

		}

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

			*size += opt_size;

			remaining -= opt_size;

		}

		return true;

	}



	snd_data_fin = mptcp_data_fin_enabled(msk);

	if (mptcp_established_options_mp(sk, skb, snd_data_fin, &opt_size, remaining, opts))

		ret = true;

	else if (mptcp_established_options_dss(sk, skb, snd_data_fin, &opt_size, remaining, opts))

	else if (mptcp_established_options_dss(sk, skb, snd_data_fin, &opt_size, remaining, opts)) {

		ret = true;

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

			*size += opt_size;

			remaining -= opt_size;

			return true;

		}

	}



	/* we reserved enough space for the above options, and exceeding the

	 * TCP option space would be fatal
@@ -1210,6 +1247,20 @@ static u16 mptcp_make_csum(const struct mptcp_ext *mpext) 
void mptcp_write_options(__be32 *ptr, const struct tcp_sock *tp,

			 struct mptcp_out_options *opts)

{

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

		const struct sock *ssk = (const struct sock *)tp;

		struct mptcp_subflow_context *subflow;



		subflow = mptcp_subflow_ctx(ssk);

		subflow->send_mp_fail = 0;



		*ptr++ = mptcp_option(MPTCPOPT_MP_FAIL,

				      TCPOLEN_MPTCP_FAIL,

				      0, 0);

		put_unaligned_be64(opts->fail_seq, ptr);

		ptr += 2;

	}



	/* RST is mutually exclusive with everything else */

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

		*ptr++ = mptcp_option(MPTCPOPT_RST,

net/mptcp/protocol.h

+3 −0
Original line number Diff line number Diff line
@@ -27,6 +27,7 @@ 
#define OPTION_MPTCP_PRIO	BIT(9)

#define OPTION_MPTCP_RST	BIT(10)

#define OPTION_MPTCP_DSS	BIT(11)

#define OPTION_MPTCP_FAIL	BIT(12)



/* MPTCP option subtypes */

#define MPTCPOPT_MP_CAPABLE	0
@@ -68,6 +69,7 @@ 
#define TCPOLEN_MPTCP_PRIO_ALIGN	4

#define TCPOLEN_MPTCP_FASTCLOSE		12

#define TCPOLEN_MPTCP_RST		4

#define TCPOLEN_MPTCP_FAIL		12



#define TCPOLEN_MPTCP_MPC_ACK_DATA_CSUM	(TCPOLEN_MPTCP_DSS_CHECKSUM + TCPOLEN_MPTCP_MPC_ACK_DATA)
@@ -429,6 +431,7 @@ struct mptcp_subflow_context { 
		mpc_map : 1,

		backup : 1,

		send_mp_prio : 1,

		send_mp_fail : 1,

		rx_eof : 1,

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

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