Commit 76e2a55d authored by Paolo Abeni's avatar Paolo Abeni Committed by Jakub Kicinski
Browse files

mptcp: better msk-level shutdown. 



Instead of re-implementing most of inet_shutdown, re-use
such helper, and implement the MPTCP-specific bits at the
'proto' level.

The msk-level disconnect() can now be invoked, lets provide a
suitable implementation.

As a side effect, this fixes bad state management for listener
sockets. The latter could lead to division by 0 oops since
commit ea4ca586 ("mptcp: refine MPTCP-level ack scheduling").

Fixes: 43b54c6e ("mptcp: Use full MPTCP-level disconnect state machine")
Fixes: ea4ca586 ("mptcp: refine MPTCP-level ack scheduling")
Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
Reviewed-by: default avatarMat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 20bc80b6

net/mptcp/protocol.c

+17 −45
Original line number Diff line number Diff line
@@ -2642,11 +2642,12 @@ static void mptcp_copy_inaddrs(struct sock *msk, const struct sock *ssk) 


static int mptcp_disconnect(struct sock *sk, int flags)

{

	/* Should never be called.

	 * inet_stream_connect() calls ->disconnect, but that

	 * refers to the subflow socket, not the mptcp one.

	 */

	WARN_ON_ONCE(1);

	struct mptcp_subflow_context *subflow;

	struct mptcp_sock *msk = mptcp_sk(sk);



	__mptcp_flush_join_list(msk);

	mptcp_for_each_subflow(msk, subflow)

		tcp_disconnect(mptcp_subflow_tcp_sock(subflow), flags);

	return 0;

}
@@ -3089,6 +3090,14 @@ bool mptcp_finish_join(struct sock *ssk) 
	return true;

}



static void mptcp_shutdown(struct sock *sk, int how)

{

	pr_debug("sk=%p, how=%d", sk, how);



	if ((how & SEND_SHUTDOWN) && mptcp_close_state(sk))

		__mptcp_wr_shutdown(sk);

}



static struct proto mptcp_prot = {

	.name		= "MPTCP",

	.owner		= THIS_MODULE,
@@ -3098,7 +3107,7 @@ static struct proto mptcp_prot = { 
	.accept		= mptcp_accept,

	.setsockopt	= mptcp_setsockopt,

	.getsockopt	= mptcp_getsockopt,

	.shutdown	= tcp_shutdown,

	.shutdown	= mptcp_shutdown,

	.destroy	= mptcp_destroy,

	.sendmsg	= mptcp_sendmsg,

	.recvmsg	= mptcp_recvmsg,
@@ -3344,43 +3353,6 @@ static __poll_t mptcp_poll(struct file *file, struct socket *sock, 
	return mask;

}



static int mptcp_shutdown(struct socket *sock, int how)

{

	struct mptcp_sock *msk = mptcp_sk(sock->sk);

	struct sock *sk = sock->sk;

	int ret = 0;



	pr_debug("sk=%p, how=%d", msk, how);



	lock_sock(sk);



	how++;

	if ((how & ~SHUTDOWN_MASK) || !how) {

		ret = -EINVAL;

		goto out_unlock;

	}



	if (sock->state == SS_CONNECTING) {

		if ((1 << sk->sk_state) &

		    (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_CLOSE))

			sock->state = SS_DISCONNECTING;

		else

			sock->state = SS_CONNECTED;

	}



	sk->sk_shutdown |= how;

	if ((how & SEND_SHUTDOWN) && mptcp_close_state(sk))

		__mptcp_wr_shutdown(sk);



	/* Wake up anyone sleeping in poll. */

	sk->sk_state_change(sk);



out_unlock:

	release_sock(sk);



	return ret;

}



static const struct proto_ops mptcp_stream_ops = {

	.family		   = PF_INET,

	.owner		   = THIS_MODULE,
@@ -3394,7 +3366,7 @@ static const struct proto_ops mptcp_stream_ops = { 
	.ioctl		   = inet_ioctl,

	.gettstamp	   = sock_gettstamp,

	.listen		   = mptcp_listen,

	.shutdown	   = mptcp_shutdown,

	.shutdown	   = inet_shutdown,

	.setsockopt	   = sock_common_setsockopt,

	.getsockopt	   = sock_common_getsockopt,

	.sendmsg	   = inet_sendmsg,
@@ -3444,7 +3416,7 @@ static const struct proto_ops mptcp_v6_stream_ops = { 
	.ioctl		   = inet6_ioctl,

	.gettstamp	   = sock_gettstamp,

	.listen		   = mptcp_listen,

	.shutdown	   = mptcp_shutdown,

	.shutdown	   = inet_shutdown,

	.setsockopt	   = sock_common_setsockopt,

	.getsockopt	   = sock_common_getsockopt,

	.sendmsg	   = inet6_sendmsg,