Commit 0784c25d authored by Jakub Kicinski's avatar Jakub Kicinski
Browse files

Merge branch 'mptcp-miscellaneous-fixes-and-a-new-test-case' 

Mat Martineau says:

====================
mptcp: Miscellaneous fixes and a new test case

Patches 1 and 3 remove helpers that were iterating over the subflow
connection list without proper locking. Iteration was not needed in
either case.

Patch 2 fixes handling of MP_FAIL timeout, checking for orphaned
subflows instead of using the MPTCP socket data lock and connection
state.

Patch 4 adds a test for MP_FAIL timeout using tc pedit to induce checksum
failures.
====================

Link: https://lore.kernel.org/r/20220518220446.209750-1-mathew.j.martineau@linux.intel.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parents 9ad084d6 2ba18161

net/mptcp/pm.c

+3 −6
Original line number Diff line number Diff line
@@ -303,7 +303,7 @@ void mptcp_pm_mp_fail_received(struct sock *sk, u64 fail_seq) 


	pr_debug("fail_seq=%llu", fail_seq);



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

	if (!READ_ONCE(msk->allow_infinite_fallback))

		return;



	if (!READ_ONCE(subflow->mp_fail_response_expect)) {
@@ -312,13 +312,10 @@ 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) {

	} else if (!sock_flag(sk, SOCK_DEAD)) {

		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

+1 −15
Original line number Diff line number Diff line
@@ -2190,23 +2190,10 @@ mp_fail_response_expect_subflow(struct mptcp_sock *msk) 
	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);

}
@@ -2588,7 +2575,6 @@ 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:

net/mptcp/protocol.h

+0 −14
Original line number Diff line number Diff line
@@ -117,7 +117,6 @@ 
#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
@@ -650,19 +649,6 @@ static inline void mptcp_subflow_tcp_fallback(struct sock *sk, 
	inet_csk(sk)->icsk_af_ops = ctx->icsk_af_ops;

}



static inline bool mptcp_has_another_subflow(struct sock *ssk)

{

	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk), *tmp;

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



	mptcp_for_each_subflow(msk, tmp) {

		if (tmp != subflow)

			return true;

	}



	return false;

}



void __init mptcp_proto_init(void);

#if IS_ENABLED(CONFIG_MPTCP_IPV6)

int __init mptcp_proto_v6_init(void);

net/mptcp/subflow.c

+5 −10
Original line number Diff line number Diff line
@@ -1016,12 +1016,9 @@ 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)

		if (!sock_flag(ssk, SOCK_DEAD))

			sk_stop_timer(sk, &sk->sk_timer);

			mptcp_data_unlock(sk);

		}



		return MAPPING_INVALID;

	}
@@ -1233,8 +1230,7 @@ static bool subflow_check_data_avail(struct sock *ssk) 
	if (!__mptcp_check_fallback(msk)) {

		/* RFC 8684 section 3.7. */

		if (subflow->send_mp_fail) {

			if (mptcp_has_another_subflow(ssk) ||

			    !READ_ONCE(msk->allow_infinite_fallback)) {

			if (!READ_ONCE(msk->allow_infinite_fallback)) {

				ssk->sk_err = EBADMSG;

				tcp_set_state(ssk, TCP_CLOSE);

				subflow->reset_transient = 0;
@@ -1242,9 +1238,8 @@ 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 {

			} else if (!sock_flag(ssk, SOCK_DEAD)) {

				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);

tools/testing/selftests/net/mptcp/mptcp_join.sh

+10 −0
Original line number Diff line number Diff line
@@ -2732,6 +2732,16 @@ fail_tests() 
		chk_join_nr 0 0 0 +1 +0 1 0 1 "$(pedit_action_pkts)"

		chk_fail_nr 1 -1 invert

	fi



	# multiple subflows

	if reset_with_fail "MP_FAIL MP_RST" 2; then

		tc -n $ns2 qdisc add dev ns2eth1 root netem rate 1mbit delay 5

		pm_nl_set_limits $ns1 0 1

		pm_nl_set_limits $ns2 0 1

		pm_nl_add_endpoint $ns2 10.0.2.2 dev ns2eth2 flags subflow

		run_tests $ns1 $ns2 10.0.1.1 1024

		chk_join_nr 1 1 1 1 0 1 1 0 "$(pedit_action_pkts)"

	fi

}



userspace_tests()