Commit 124de271 authored by David S. Miller's avatar David S. Miller
Browse files

Merge branch 'mptcp-MP_FAIL-timeout' 



Mat Martineau says:

====================
mptcp: Timeout for MP_FAIL response

When one peer sends an infinite mapping to coordinate fallback from
MPTCP to regular TCP, the other peer is expected to send a packet with
the MPTCP MP_FAIL option to acknowledge the infinite mapping. Rather
than leave the connection in some half-fallback state, this series adds
a timeout after which the infinite mapping sender will reset the
connection.

Patch 1 adds a fallback self test.

Patches 2-5 make use of the MPTCP socket's retransmit timer to reset the
MPTCP connection if no MP_FAIL was received.

Patches 6 and 7 extends the self test to check MP_FAIL-related MIBs.
====================

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents b1190d51 53f368bf

net/mptcp/pm.c

+17 −1
Original line number Diff line number Diff line
@@ -287,11 +287,27 @@ 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);



	if (!mptcp_has_another_subflow(sk) && READ_ONCE(msk->allow_infinite_fallback))

	if (mptcp_has_another_subflow(sk) || !READ_ONCE(msk->allow_infinite_fallback))

		return;



	if (!READ_ONCE(subflow->mp_fail_response_expect)) {

		pr_debug("send MP_FAIL response and infinite map");



		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);

	}

}



/* path manager helpers */

net/mptcp/protocol.c

+62 −2
Original line number Diff line number Diff line
@@ -1605,8 +1605,10 @@ void __mptcp_push_pending(struct sock *sk, unsigned int flags) 


out:

	/* ensure the rtx timer is running */

	mptcp_data_lock(sk);

	if (!mptcp_timer_pending(sk))

		mptcp_reset_timer(sk);

	mptcp_data_unlock(sk);

	if (copied)

		__mptcp_check_send_data_fin(sk);

}
@@ -2167,10 +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);

}
@@ -2491,8 +2521,27 @@ static void __mptcp_retrans(struct sock *sk) 
reset_timer:

	mptcp_check_and_set_pending(sk);



	mptcp_data_lock(sk);

	if (!mptcp_timer_pending(sk))

		mptcp_reset_timer(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)
@@ -2535,6 +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);
@@ -2651,8 +2703,10 @@ void mptcp_subflow_shutdown(struct sock *sk, struct sock *ssk, int how) 
		} else {

			pr_debug("Sending DATA_FIN on subflow %p", ssk);

			tcp_send_ack(ssk);

			mptcp_data_lock(sk);

			if (!mptcp_timer_pending(sk))

				mptcp_reset_timer(sk);

			mptcp_data_unlock(sk);

		}

		break;

	}
@@ -2753,8 +2807,10 @@ static void __mptcp_destroy_sock(struct sock *sk) 
	/* join list will be eventually flushed (with rst) at sock lock release time*/

	list_splice_init(&msk->conn_list, &conn_list);



	sk_stop_timer(sk, &msk->sk.icsk_retransmit_timer);

	mptcp_data_lock(sk);

	mptcp_stop_timer(sk);

	sk_stop_timer(sk, &sk->sk_timer);

	mptcp_data_unlock(sk);

	msk->pm.status = 0;



	/* clears msk->subflow, allowing the following loop to close
@@ -2816,7 +2872,9 @@ static void mptcp_close(struct sock *sk, long timeout) 
		__mptcp_destroy_sock(sk);

		do_cancel_work = true;

	} else {

		mptcp_data_lock(sk);

		sk_reset_timer(sk, &sk->sk_timer, jiffies + TCP_TIMEWAIT_LEN);

		mptcp_data_unlock(sk);

	}

	release_sock(sk);

	if (do_cancel_work)
@@ -2861,8 +2919,10 @@ static int mptcp_disconnect(struct sock *sk, int flags) 
		__mptcp_close_ssk(sk, ssk, subflow, MPTCP_CF_FASTCLOSE);

	}



	sk_stop_timer(sk, &msk->sk.icsk_retransmit_timer);

	mptcp_data_lock(sk);

	mptcp_stop_timer(sk);

	sk_stop_timer(sk, &sk->sk_timer);

	mptcp_data_unlock(sk);



	if (mptcp_sk(sk)->token)

		mptcp_event(MPTCP_EVENT_CLOSED, mptcp_sk(sk), NULL, GFP_KERNEL);

net/mptcp/protocol.h

+2 −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
@@ -448,6 +449,7 @@ struct mptcp_subflow_context { 
		stale : 1,	    /* unable to snd/rcv data, do not use for xmit */

		local_id_valid : 1; /* local_id is correctly initialized */

	enum mptcp_data_avail data_avail;

	bool	mp_fail_response_expect;

	u32	remote_nonce;

	u64	thmac;

	u32	local_nonce;

net/mptcp/subflow.c

+13 −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;

	}
@@ -1217,6 +1224,12 @@ static bool subflow_check_data_avail(struct sock *ssk) 
				tcp_send_active_reset(ssk, GFP_ATOMIC);

				while ((skb = skb_peek(&ssk->sk_receive_queue)))

					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;

tools/testing/selftests/net/mptcp/config

+8 −0
Original line number Diff line number Diff line
@@ -12,6 +12,9 @@ CONFIG_NF_TABLES=m 
CONFIG_NFT_COMPAT=m

CONFIG_NETFILTER_XTABLES=m

CONFIG_NETFILTER_XT_MATCH_BPF=m

CONFIG_NETFILTER_XT_MATCH_LENGTH=m

CONFIG_NETFILTER_XT_MATCH_STATISTIC=m

CONFIG_NETFILTER_XT_TARGET_MARK=m

CONFIG_NF_TABLES_INET=y

CONFIG_NFT_TPROXY=m

CONFIG_NFT_SOCKET=m
@@ -19,3 +22,8 @@ CONFIG_IP_ADVANCED_ROUTER=y 
CONFIG_IP_MULTIPLE_TABLES=y

CONFIG_IP_NF_TARGET_REJECT=m

CONFIG_IPV6_MULTIPLE_TABLES=y

CONFIG_NET_ACT_CSUM=m

CONFIG_NET_ACT_PEDIT=m

CONFIG_NET_CLS_ACT=y

CONFIG_NET_CLS_FW=m

CONFIG_NET_SCH_INGRESS=m