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authorPaolo Abeni <pabeni@redhat.com>2020-05-29 17:43:29 +0200
committerDavid S. Miller <davem@davemloft.net>2020-05-30 21:39:13 -0700
commit41be81a8d3d09acb9033799938306349328861f9 (patch)
tree20cb78f94610de7a0a694a4f87436d9db51a5f9b
parent05aa69e5cba61d8900970a364825f854401694ec (diff)
mptcp: fix unblocking connect()
Currently unblocking connect() on MPTCP sockets fails frequently. If mptcp_stream_connect() is invoked to complete a previously attempted unblocking connection, it will still try to create the first subflow via __mptcp_socket_create(). If the 3whs is completed and the 'can_ack' flag is already set, the latter will fail with -EINVAL. This change addresses the issue checking for pending connect and delegating the completion to the first subflow. Additionally do msk addresses and sk_state changes only when needed. Fixes: 2303f994b3e1 ("mptcp: Associate MPTCP context with TCP socket") Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--net/mptcp/protocol.c20
1 files changed, 18 insertions, 2 deletions
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index c8675d2eb5b9..8959a74f707d 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -1712,6 +1712,14 @@ static int mptcp_stream_connect(struct socket *sock, struct sockaddr *uaddr,
int err;
lock_sock(sock->sk);
+ if (sock->state != SS_UNCONNECTED && msk->subflow) {
+ /* pending connection or invalid state, let existing subflow
+ * cope with that
+ */
+ ssock = msk->subflow;
+ goto do_connect;
+ }
+
ssock = __mptcp_socket_create(msk, TCP_SYN_SENT);
if (IS_ERR(ssock)) {
err = PTR_ERR(ssock);
@@ -1726,9 +1734,17 @@ static int mptcp_stream_connect(struct socket *sock, struct sockaddr *uaddr,
mptcp_subflow_ctx(ssock->sk)->request_mptcp = 0;
#endif
+do_connect:
err = ssock->ops->connect(ssock, uaddr, addr_len, flags);
- inet_sk_state_store(sock->sk, inet_sk_state_load(ssock->sk));
- mptcp_copy_inaddrs(sock->sk, ssock->sk);
+ sock->state = ssock->state;
+
+ /* on successful connect, the msk state will be moved to established by
+ * subflow_finish_connect()
+ */
+ if (!err || err == EINPROGRESS)
+ mptcp_copy_inaddrs(sock->sk, ssock->sk);
+ else
+ inet_sk_state_store(sock->sk, inet_sk_state_load(ssock->sk));
unlock:
release_sock(sock->sk);