Commit 30b172ee authored by Jakub Kicinski's avatar Jakub Kicinski
Browse files

Merge branch 'mptcp-mptcp-support-for-tcp_fastopen_connect' 

Mat Martineau says:

====================
mptcp: MPTCP support for TCP_FASTOPEN_CONNECT

RFC 8684 appendix B describes how to use TCP Fast Open with MPTCP. This
series allows TFO use with MPTCP using the TCP_FASTOPEN_CONNECT socket
option. The scope here is limited to the initiator of the connection -
support for MSG_FASTOPEN and the listener side of the connection will be
in a separate series. The preexisting TCP fastopen code does most of the
work, so these changes mostly involve plumbing MPTCP through to those
TCP functions.

Patch 1 changes the MPTCP socket option code to pass the
TCP_FASTOPEN_CONNECT option through to the initial unconnected subflow.

Patch 2 exports the existing tcp_sendmsg_fastopen() function from tcp.c

Patch 3 adds the call to tcp_sendmsg_fastopen() from the MPTCP send
function.

Patch 4 modifies mptcp_poll() to handle the deferred TFO connection.
====================

Link: https://lore.kernel.org/r/20220926232739.76317-1-mathew.j.martineau@linux.intel.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parents 63a8bf85 a42cf9d1

include/net/tcp.h

+2 −0
Original line number Diff line number Diff line
@@ -327,6 +327,8 @@ void tcp_remove_empty_skb(struct sock *sk); 
int tcp_v4_tw_remember_stamp(struct inet_timewait_sock *tw);

int tcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t size);

int tcp_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t size);

int tcp_sendmsg_fastopen(struct sock *sk, struct msghdr *msg, int *copied,

			 size_t size, struct ubuf_info *uarg);

int tcp_sendpage(struct sock *sk, struct page *page, int offset, size_t size,

		 int flags);

int tcp_sendpage_locked(struct sock *sk, struct page *page, int offset,

net/ipv4/tcp.c

+2 −3
Original line number Diff line number Diff line
@@ -1162,9 +1162,8 @@ void tcp_free_fastopen_req(struct tcp_sock *tp) 
	}

}



static int tcp_sendmsg_fastopen(struct sock *sk, struct msghdr *msg,

				int *copied, size_t size,

				struct ubuf_info *uarg)

int tcp_sendmsg_fastopen(struct sock *sk, struct msghdr *msg, int *copied,

			 size_t size, struct ubuf_info *uarg)

{

	struct tcp_sock *tp = tcp_sk(sk);

	struct inet_sock *inet = inet_sk(sk);

net/mptcp/protocol.c

+26 −0
Original line number Diff line number Diff line
@@ -1677,6 +1677,7 @@ static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) 
{

	struct mptcp_sock *msk = mptcp_sk(sk);

	struct page_frag *pfrag;

	struct socket *ssock;

	size_t copied = 0;

	int ret = 0;

	long timeo;
@@ -1690,6 +1691,27 @@ static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) 


	lock_sock(sk);



	ssock = __mptcp_nmpc_socket(msk);

	if (unlikely(ssock && inet_sk(ssock->sk)->defer_connect)) {

		struct sock *ssk = ssock->sk;

		int copied_syn = 0;



		lock_sock(ssk);



		ret = tcp_sendmsg_fastopen(ssk, msg, &copied_syn, len, NULL);

		copied += copied_syn;

		if (ret == -EINPROGRESS && copied_syn > 0) {

			/* reflect the new state on the MPTCP socket */

			inet_sk_state_store(sk, inet_sk_state_load(ssk));

			release_sock(ssk);

			goto out;

		} else if (ret) {

			release_sock(ssk);

			goto out;

		}

		release_sock(ssk);

	}



	timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);



	if ((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) {
@@ -3526,6 +3548,7 @@ static int mptcp_stream_connect(struct socket *sock, struct sockaddr *uaddr, 


do_connect:

	err = ssock->ops->connect(ssock, uaddr, addr_len, flags);

	inet_sk(sock->sk)->defer_connect = inet_sk(ssock->sk)->defer_connect;

	sock->state = ssock->state;



	/* on successful connect, the msk state will be moved to established by
@@ -3676,6 +3699,9 @@ static __poll_t mptcp_poll(struct file *file, struct socket *sock, 
	if (state != TCP_SYN_SENT && state != TCP_SYN_RECV) {

		mask |= mptcp_check_readable(msk);

		mask |= mptcp_check_writeable(msk);

	} else if (state == TCP_SYN_SENT && inet_sk(sk)->defer_connect) {

		/* cf tcp_poll() note about TFO */

		mask |= EPOLLOUT | EPOLLWRNORM;

	}

	if (sk->sk_shutdown == SHUTDOWN_MASK || state == TCP_CLOSE)

		mask |= EPOLLHUP;

net/mptcp/sockopt.c

+18 −1
Original line number Diff line number Diff line
@@ -559,6 +559,7 @@ static bool mptcp_supported_sockopt(int level, int optname) 
		case TCP_NOTSENT_LOWAT:

		case TCP_TX_DELAY:

		case TCP_INQ:

		case TCP_FASTOPEN_CONNECT:

			return true;

		}
@@ -567,7 +568,7 @@ static bool mptcp_supported_sockopt(int level, int optname) 
		/* TCP_REPAIR, TCP_REPAIR_QUEUE, TCP_QUEUE_SEQ, TCP_REPAIR_OPTIONS,

		 * TCP_REPAIR_WINDOW are not supported, better avoid this mess

		 */

		/* TCP_FASTOPEN_KEY, TCP_FASTOPEN TCP_FASTOPEN_CONNECT, TCP_FASTOPEN_NO_COOKIE,

		/* TCP_FASTOPEN_KEY, TCP_FASTOPEN, TCP_FASTOPEN_NO_COOKIE,

		 * are not supported fastopen is currently unsupported

		 */

	}
@@ -768,6 +769,19 @@ static int mptcp_setsockopt_sol_tcp_defer(struct mptcp_sock *msk, sockptr_t optv 
	return tcp_setsockopt(listener->sk, SOL_TCP, TCP_DEFER_ACCEPT, optval, optlen);

}



static int mptcp_setsockopt_sol_tcp_fastopen_connect(struct mptcp_sock *msk, sockptr_t optval,

						     unsigned int optlen)

{

	struct socket *sock;



	/* Limit to first subflow */

	sock = __mptcp_nmpc_socket(msk);

	if (!sock)

		return -EINVAL;



	return tcp_setsockopt(sock->sk, SOL_TCP, TCP_FASTOPEN_CONNECT, optval, optlen);

}



static int mptcp_setsockopt_sol_tcp(struct mptcp_sock *msk, int optname,

				    sockptr_t optval, unsigned int optlen)

{
@@ -796,6 +810,8 @@ static int mptcp_setsockopt_sol_tcp(struct mptcp_sock *msk, int optname, 
		return mptcp_setsockopt_sol_tcp_nodelay(msk, optval, optlen);

	case TCP_DEFER_ACCEPT:

		return mptcp_setsockopt_sol_tcp_defer(msk, optval, optlen);

	case TCP_FASTOPEN_CONNECT:

		return mptcp_setsockopt_sol_tcp_fastopen_connect(msk, optval, optlen);

	}



	return -EOPNOTSUPP;
@@ -1157,6 +1173,7 @@ static int mptcp_getsockopt_sol_tcp(struct mptcp_sock *msk, int optname, 
	case TCP_INFO:

	case TCP_CC_INFO:

	case TCP_DEFER_ACCEPT:

	case TCP_FASTOPEN_CONNECT:

		return mptcp_getsockopt_first_sf_only(msk, SOL_TCP, optname,

						      optval, optlen);

	case TCP_INQ: