Commit 49fa1919 authored by Geliang Tang's avatar Geliang Tang Committed by David S. Miller
Browse files

mptcp: reset subflow when MP_FAIL doesn't respond 



This patch adds a new msk->flags bit MPTCP_FAIL_NO_RESPONSE, then reuses
sk_timer to trigger a check if we have not received a response from the
peer after sending MP_FAIL. If the peer doesn't respond properly, reset
the subflow.

Signed-off-by: default avatarGeliang Tang <geliang.tang@suse.com>
Signed-off-by: default avatarMat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 9c81be0d

net/mptcp/pm.c

+8 −0
Original line number Diff line number Diff line
@@ -287,6 +287,7 @@ void mptcp_pm_mp_fail_received(struct sock *sk, u64 fail_seq) 
{

	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);

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

	struct sock *s = (struct sock *)msk;



	pr_debug("fail_seq=%llu", fail_seq);
@@ -299,6 +300,13 @@ void mptcp_pm_mp_fail_received(struct sock *sk, u64 fail_seq) 
		subflow->send_mp_fail = 1;

		MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_MPFAILTX);

		subflow->send_infinite_map = 1;

	} else if (s && inet_sk_state_load(s) != TCP_CLOSE) {

		pr_debug("MP_FAIL response received");



		mptcp_data_lock(s);

		if (inet_sk_state_load(s) != TCP_CLOSE)

			sk_stop_timer(s, &s->sk_timer);

		mptcp_data_unlock(s);

	}

}

net/mptcp/protocol.c

+48 −0
Original line number Diff line number Diff line
@@ -2169,10 +2169,38 @@ static void mptcp_retransmit_timer(struct timer_list *t) 
	sock_put(sk);

}



static struct mptcp_subflow_context *

mp_fail_response_expect_subflow(struct mptcp_sock *msk)

{

	struct mptcp_subflow_context *subflow, *ret = NULL;



	mptcp_for_each_subflow(msk, subflow) {

		if (READ_ONCE(subflow->mp_fail_response_expect)) {

			ret = subflow;

			break;

		}

	}



	return ret;

}



static void mptcp_check_mp_fail_response(struct mptcp_sock *msk)

{

	struct mptcp_subflow_context *subflow;

	struct sock *sk = (struct sock *)msk;



	bh_lock_sock(sk);

	subflow = mp_fail_response_expect_subflow(msk);

	if (subflow)

		__set_bit(MPTCP_FAIL_NO_RESPONSE, &msk->flags);

	bh_unlock_sock(sk);

}



static void mptcp_timeout_timer(struct timer_list *t)

{

	struct sock *sk = from_timer(sk, t, sk_timer);



	mptcp_check_mp_fail_response(mptcp_sk(sk));

	mptcp_schedule_work(sk);

	sock_put(sk);

}
@@ -2499,6 +2527,23 @@ static void __mptcp_retrans(struct sock *sk) 
	mptcp_data_unlock(sk);

}



static void mptcp_mp_fail_no_response(struct mptcp_sock *msk)

{

	struct mptcp_subflow_context *subflow;

	struct sock *ssk;

	bool slow;



	subflow = mp_fail_response_expect_subflow(msk);

	if (subflow) {

		pr_debug("MP_FAIL doesn't respond, reset the subflow");



		ssk = mptcp_subflow_tcp_sock(subflow);

		slow = lock_sock_fast(ssk);

		mptcp_subflow_reset(ssk);

		unlock_sock_fast(ssk, slow);

	}

}



static void mptcp_worker(struct work_struct *work)

{

	struct mptcp_sock *msk = container_of(work, struct mptcp_sock, work);
@@ -2539,6 +2584,9 @@ static void mptcp_worker(struct work_struct *work) 
	if (test_and_clear_bit(MPTCP_WORK_RTX, &msk->flags))

		__mptcp_retrans(sk);



	if (test_and_clear_bit(MPTCP_FAIL_NO_RESPONSE, &msk->flags))

		mptcp_mp_fail_no_response(msk);



unlock:

	release_sock(sk);

	sock_put(sk);

net/mptcp/protocol.h

+1 −0
Original line number Diff line number Diff line
@@ -116,6 +116,7 @@ 
#define MPTCP_WORK_EOF		3

#define MPTCP_FALLBACK_DONE	4

#define MPTCP_WORK_CLOSE_SUBFLOW 5

#define MPTCP_FAIL_NO_RESPONSE	6



/* MPTCP socket release cb flags */

#define MPTCP_PUSH_PENDING	1

net/mptcp/subflow.c

+11 −0
Original line number Diff line number Diff line
@@ -968,6 +968,7 @@ static enum mapping_status get_mapping_status(struct sock *ssk, 
{

	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);

	bool csum_reqd = READ_ONCE(msk->csum_enabled);

	struct sock *sk = (struct sock *)msk;

	struct mptcp_ext *mpext;

	struct sk_buff *skb;

	u16 data_len;
@@ -1009,6 +1010,12 @@ static enum mapping_status get_mapping_status(struct sock *ssk, 
		pr_debug("infinite mapping received");

		MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_INFINITEMAPRX);

		subflow->map_data_len = 0;

		if (sk && inet_sk_state_load(sk) != TCP_CLOSE) {

			mptcp_data_lock(sk);

			if (inet_sk_state_load(sk) != TCP_CLOSE)

				sk_stop_timer(sk, &sk->sk_timer);

			mptcp_data_unlock(sk);

		}

		return MAPPING_INVALID;

	}
@@ -1219,6 +1226,10 @@ static bool subflow_check_data_avail(struct sock *ssk) 
					sk_eat_skb(ssk, skb);

			} else {

				WRITE_ONCE(subflow->mp_fail_response_expect, true);

				/* The data lock is acquired in __mptcp_move_skbs() */

				sk_reset_timer((struct sock *)msk,

					       &((struct sock *)msk)->sk_timer,

					       jiffies + TCP_RTO_MAX);

			}

			WRITE_ONCE(subflow->data_avail, MPTCP_SUBFLOW_NODATA);

			return true;