Commit 3b04cba7 authored by Jakub Kicinski's avatar Jakub Kicinski
Browse files

Merge branch 'mptcp-properly-clean-up-unaccepted-subflows' 

Mat Martineau says:

====================
mptcp: Properly clean up unaccepted subflows

Patch 1 factors out part of the mptcp_close() function for use by a caller
that already owns the socket lock. This is a prerequisite for patch 2.

Patch 2 is the fix that fully cleans up the unaccepted subflow sockets.
====================

Link: https://lore.kernel.org/r/20220927193158.195729-1-mathew.j.martineau@linux.intel.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parents 3e1308a7 30e51b92

net/mptcp/protocol.c

+13 −3
Original line number Diff line number Diff line
@@ -2662,7 +2662,7 @@ static void __mptcp_clear_xmit(struct sock *sk) 
		dfrag_clear(sk, dfrag);

}



static void mptcp_cancel_work(struct sock *sk)

void mptcp_cancel_work(struct sock *sk)

{

	struct mptcp_sock *msk = mptcp_sk(sk);
@@ -2802,13 +2802,12 @@ static void __mptcp_destroy_sock(struct sock *sk) 
	sock_put(sk);

}



static void mptcp_close(struct sock *sk, long timeout)

bool __mptcp_close(struct sock *sk, long timeout)

{

	struct mptcp_subflow_context *subflow;

	struct mptcp_sock *msk = mptcp_sk(sk);

	bool do_cancel_work = false;



	lock_sock(sk);

	sk->sk_shutdown = SHUTDOWN_MASK;



	if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE)) {
@@ -2850,6 +2849,17 @@ static void mptcp_close(struct sock *sk, long timeout) 
	} else {

		mptcp_reset_timeout(msk, 0);

	}



	return do_cancel_work;

}



static void mptcp_close(struct sock *sk, long timeout)

{

	bool do_cancel_work;



	lock_sock(sk);



	do_cancel_work = __mptcp_close(sk, timeout);

	release_sock(sk);

	if (do_cancel_work)

		mptcp_cancel_work(sk);

net/mptcp/protocol.h

+2 −0
Original line number Diff line number Diff line
@@ -612,6 +612,8 @@ void mptcp_subflow_reset(struct sock *ssk); 
void mptcp_subflow_queue_clean(struct sock *ssk);

void mptcp_sock_graft(struct sock *sk, struct socket *parent);

struct socket *__mptcp_nmpc_socket(const struct mptcp_sock *msk);

bool __mptcp_close(struct sock *sk, long timeout);

void mptcp_cancel_work(struct sock *sk);



bool mptcp_addresses_equal(const struct mptcp_addr_info *a,

			   const struct mptcp_addr_info *b, bool use_port);

net/mptcp/subflow.c

+7 −26
Original line number Diff line number Diff line
@@ -602,30 +602,6 @@ static bool subflow_hmac_valid(const struct request_sock *req, 
	return !crypto_memneq(hmac, mp_opt->hmac, MPTCPOPT_HMAC_LEN);

}



static void mptcp_sock_destruct(struct sock *sk)

{

	/* if new mptcp socket isn't accepted, it is free'd

	 * from the tcp listener sockets request queue, linked

	 * from req->sk.  The tcp socket is released.

	 * This calls the ULP release function which will

	 * also remove the mptcp socket, via

	 * sock_put(ctx->conn).

	 *

	 * Problem is that the mptcp socket will be in

	 * ESTABLISHED state and will not have the SOCK_DEAD flag.

	 * Both result in warnings from inet_sock_destruct.

	 */

	if ((1 << sk->sk_state) & (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) {

		sk->sk_state = TCP_CLOSE;

		WARN_ON_ONCE(sk->sk_socket);

		sock_orphan(sk);

	}



	/* We don't need to clear msk->subflow, as it's still NULL at this point */

	mptcp_destroy_common(mptcp_sk(sk), 0);

	inet_sock_destruct(sk);

}



static void mptcp_force_close(struct sock *sk)

{

	/* the msk is not yet exposed to user-space */
@@ -768,7 +744,6 @@ static struct sock *subflow_syn_recv_sock(const struct sock *sk, 
			/* new mpc subflow takes ownership of the newly

			 * created mptcp socket

			 */

			new_msk->sk_destruct = mptcp_sock_destruct;

			mptcp_sk(new_msk)->setsockopt_seq = ctx->setsockopt_seq;

			mptcp_pm_new_connection(mptcp_sk(new_msk), child, 1);

			mptcp_token_accept(subflow_req, mptcp_sk(new_msk));
@@ -1763,13 +1738,19 @@ void mptcp_subflow_queue_clean(struct sock *listener_ssk) 


	for (msk = head; msk; msk = next) {

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

		bool slow;

		bool slow, do_cancel_work;



		sock_hold(sk);

		slow = lock_sock_fast_nested(sk);

		next = msk->dl_next;

		msk->first = NULL;

		msk->dl_next = NULL;



		do_cancel_work = __mptcp_close(sk, 0);

		unlock_sock_fast(sk, slow);

		if (do_cancel_work)

			mptcp_cancel_work(sk);

		sock_put(sk);

	}



	/* we are still under the listener msk socket lock */