int
virtio_transport_notify_poll_out(struct vsock_sock *vsk,
size_t target,
bool *space_avail_now)
{
s64 free_space;
free_space = vsock_stream_has_space(vsk);
if (free_space > 0)
*space_avail_now = true;
else if (free_space == 0)
*space_avail_now = false;
return 0;
}
static int
vmci_transport_notify_pkt_poll_out(struct sock *sk,
size_t target, bool *space_avail_now)
{
s64 produce_q_free_space;
struct vsock_sock *vsk = vsock_sk(sk);
produce_q_free_space = vsock_stream_has_space(vsk);
if (produce_q_free_space > 0) {
*space_avail_now = true;
return 0;
} else if (produce_q_free_space == 0) {
/* This is a connected socket but we can't currently send data.
* Nothing else to do.
*/
*space_avail_now = false;
}
return 0;
}
static int vsock_stream_sendmsg(struct socket *sock, struct msghdr *msg,
size_t len)
{
struct sock *sk;
struct vsock_sock *vsk;
ssize_t total_written;
long timeout;
int err;
struct vsock_transport_send_notify_data send_data;
DEFINE_WAIT_FUNC(wait, woken_wake_function);
sk = sock->sk;
vsk = vsock_sk(sk);
total_written = 0;
err = 0;
if (msg->msg_flags & MSG_OOB)
return -EOPNOTSUPP;
lock_sock(sk);
/* Callers should not provide a destination with stream sockets. */
if (msg->msg_namelen) {
err = sk->sk_state == TCP_ESTABLISHED ? -EISCONN : -EOPNOTSUPP;
goto out;
}
/* Send data only if both sides are not shutdown in the direction. */
if (sk->sk_shutdown & SEND_SHUTDOWN ||
vsk->peer_shutdown & RCV_SHUTDOWN) {
err = -EPIPE;
goto out;
}
if (sk->sk_state != TCP_ESTABLISHED ||
!vsock_addr_bound(&vsk->local_addr)) {
err = -ENOTCONN;
goto out;
}
if (!vsock_addr_bound(&vsk->remote_addr)) {
err = -EDESTADDRREQ;
goto out;
}
/* Wait for room in the produce queue to enqueue our user's data. */
timeout = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
err = transport->notify_send_init(vsk, &send_data);
if (err < 0)
goto out;
while (total_written < len) {
ssize_t written;
add_wait_queue(sk_sleep(sk), &wait);
while (vsock_stream_has_space(vsk) == 0 &&
sk->sk_err == 0 &&
!(sk->sk_shutdown & SEND_SHUTDOWN) &&
!(vsk->peer_shutdown & RCV_SHUTDOWN)) {
/* Don't wait for non-blocking sockets. */
if (timeout == 0) {
err = -EAGAIN;
remove_wait_queue(sk_sleep(sk), &wait);
goto out_err;
}
err = transport->notify_send_pre_block(vsk, &send_data);
if (err < 0) {
remove_wait_queue(sk_sleep(sk), &wait);
goto out_err;
}
release_sock(sk);
timeout = wait_woken(&wait, TASK_INTERRUPTIBLE, timeout);
lock_sock(sk);
if (signal_pending(current)) {
err = sock_intr_errno(timeout);
remove_wait_queue(sk_sleep(sk), &wait);
goto out_err;
} else if (timeout == 0) {
err = -EAGAIN;
remove_wait_queue(sk_sleep(sk), &wait);
goto out_err;
}
}
remove_wait_queue(sk_sleep(sk), &wait);
/* These checks occur both as part of and after the loop
* conditional since we need to check before and after
* sleeping.
*/
if (sk->sk_err) {
err = -sk->sk_err;
goto out_err;
} else if ((sk->sk_shutdown & SEND_SHUTDOWN) ||
(vsk->peer_shutdown & RCV_SHUTDOWN)) {
err = -EPIPE;
goto out_err;
}
err = transport->notify_send_pre_enqueue(vsk, &send_data);
if (err < 0)
goto out_err;
/* Note that enqueue will only write as many bytes as are free
* in the produce queue, so we don't need to ensure len is
* smaller than the queue size. It is the caller's
* responsibility to check how many bytes we were able to send.
*/
written = transport->stream_enqueue(
vsk, msg,
len - total_written);
if (written < 0) {
err = -ENOMEM;
goto out_err;
}
total_written += written;
err = transport->notify_send_post_enqueue(
vsk, written, &send_data);
if (err < 0)
goto out_err;
}
out_err:
if (total_written > 0)
err = total_written;
out:
release_sock(sk);
return err;
}
