Introduce vsock_unconnected_reset() and adapt vsock_connect(). Change transport assignment life cycle. On connect(), socket gets a transport assigned. If connection fails (init went wrong, peer misbehaviour, time out, signal), transport is de-assigned and socket state is re-initialized. Once the connection is established, transport remains assigned until close().
Signed-off-by: Michal Luczaj <[email protected]> --- net/vmw_vsock/af_vsock.c | 74 ++++++++++++++++++++++++++++++------------------ 1 file changed, 47 insertions(+), 27 deletions(-) diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c index 5c8e7e7d35b4..20181ddde114 100644 --- a/net/vmw_vsock/af_vsock.c +++ b/net/vmw_vsock/af_vsock.c @@ -1679,6 +1679,42 @@ static int vsock_transport_cancel_pkt(struct vsock_sock *vsk) return transport->cancel_pkt(vsk); } +static void vsock_unconnected_reset(struct sock *sk) +{ + struct vsock_sock *vsk = vsock_sk(sk); + + sock_owned_by_me(sk); + + /* + * Only connected socks may have peer_shutdown or SOCK_DONE set. + * + * Once established (TCP_ESTABLISHED, TCP_CLOSING), a socket can be + * de-assigned only on close(). But we can narrow the check down to + * states we actually expect (TCP_SYN_SENT, TCP_CLOSE). + */ + if (WARN_ON_ONCE(vsk->peer_shutdown) || + WARN_ON_ONCE(sock_flag(sk, SOCK_DONE)) || + WARN_ON_ONCE(sk->sk_state != TCP_SYN_SENT && + sk->sk_state != TCP_CLOSE)) + return; + + /* + * Try to cancel a VIRTIO_VSOCK_OP_REQUEST skb that may have been sent + * out by transport->connect(). + */ + vsock_transport_cancel_pkt(vsk); + + /* + * No need to invoke transport->release() for unconnected connectible + * sockets. Go straight for transport deassign. + */ + vsock_deassign_transport(vsk); + + /* Revert socket to initial state. Keep sk_err. */ + WRITE_ONCE(sk->sk_state, TCP_CLOSE); + sk->sk_socket->state = SS_UNCONNECTED; +} + static void vsock_connect_timeout(struct work_struct *work) { struct sock *sk; @@ -1690,11 +1726,9 @@ static void vsock_connect_timeout(struct work_struct *work) lock_sock(sk); if (sk->sk_state == TCP_SYN_SENT && (sk->sk_shutdown != SHUTDOWN_MASK)) { - sk->sk_state = TCP_CLOSE; - sk->sk_socket->state = SS_UNCONNECTED; sk->sk_err = ETIMEDOUT; sk_error_report(sk); - vsock_transport_cancel_pkt(vsk); + vsock_unconnected_reset(sk); } release_sock(sk); @@ -1760,7 +1794,7 @@ static int vsock_connect(struct socket *sock, struct sockaddr_unsized *addr, if (!transport->stream_allow(vsk, remote_addr->svm_cid, remote_addr->svm_port)) { err = -ENETUNREACH; - goto out; + goto out_reset; } if (vsock_msgzerocopy_allow(transport)) { @@ -1771,18 +1805,18 @@ static int vsock_connect(struct socket *sock, struct sockaddr_unsized *addr, * feature is supported here. */ err = -EOPNOTSUPP; - goto out; + goto out_reset; } err = vsock_auto_bind(vsk); if (err) - goto out; + goto out_reset; sk->sk_state = TCP_SYN_SENT; err = transport->connect(vsk); if (err < 0) - goto out; + goto out_reset; /* sk_err might have been set as a result of an earlier * (failed) connect attempt. @@ -1825,8 +1859,9 @@ static int vsock_connect(struct socket *sock, struct sockaddr_unsized *addr, timeout)) sock_put(sk); + finish_wait(sk_sleep(sk), &wait); /* Skip ahead to preserve error code set above. */ - goto out_wait; + goto out; } release_sock(sk); @@ -1844,12 +1879,7 @@ static int vsock_connect(struct socket *sock, struct sockaddr_unsized *addr, break; /* If connection was _not_ established and a signal/timeout came - * to be, we want the socket's state reset. User space may want - * to retry. - * - * sk_state != TCP_ESTABLISHED implies that socket is not on - * vsock_connected_table. We keep the binding and the transport - * assigned. + * to be, we want the socket's state reset. We keep the binding. */ if (signal_pending(current) || timeout == 0) { err = timeout == 0 ? -ETIMEDOUT : sock_intr_errno(timeout); @@ -1859,14 +1889,6 @@ static int vsock_connect(struct socket *sock, struct sockaddr_unsized *addr, * sk_state == TCP_SYN_SENT, which hereby we break. * In such case VIRTIO_VSOCK_OP_RST will follow. */ - sk->sk_state = TCP_CLOSE; - sock->state = SS_UNCONNECTED; - - /* Try to cancel VIRTIO_VSOCK_OP_REQUEST skb sent out by - * transport->connect(). - */ - vsock_transport_cancel_pkt(vsk); - goto out_wait; } @@ -1874,13 +1896,11 @@ static int vsock_connect(struct socket *sock, struct sockaddr_unsized *addr, } err = sock_error(sk); - if (err) { - sk->sk_state = TCP_CLOSE; - sock->state = SS_UNCONNECTED; - } - out_wait: finish_wait(sk_sleep(sk), &wait); +out_reset: + if (err) + vsock_unconnected_reset(sk); out: release_sock(sk); return err; -- 2.55.0
