Commit 9942c192 authored by Arseny Krasnov's avatar Arseny Krasnov Committed by David S. Miller
Browse files

af_vsock: implement SEQPACKET receive loop 



Add receive loop for SEQPACKET. It looks like receive loop for
STREAM, but there are differences:
1) It doesn't call notify callbacks.
2) It doesn't care about 'SO_SNDLOWAT' and 'SO_RCVLOWAT' values, because
   there is no sense for these values in SEQPACKET case.
3) It waits until whole record is received.
4) It processes and sets 'MSG_TRUNC' flag.

So to avoid extra conditions for two types of socket inside one loop, two
independent functions were created.

Signed-off-by: default avatarArseny Krasnov <arseny.krasnov@kaspersky.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 19c1b90e

include/net/af_vsock.h

+4 −0
Original line number Diff line number Diff line
@@ -135,6 +135,10 @@ struct vsock_transport { 
	bool (*stream_is_active)(struct vsock_sock *);

	bool (*stream_allow)(u32 cid, u32 port);



	/* SEQ_PACKET. */

	ssize_t (*seqpacket_dequeue)(struct vsock_sock *vsk, struct msghdr *msg,

				     int flags);



	/* Notification. */

	int (*notify_poll_in)(struct vsock_sock *, size_t, bool *);

	int (*notify_poll_out)(struct vsock_sock *, size_t, bool *);

net/vmw_vsock/af_vsock.c

+54 −1
Original line number Diff line number Diff line
@@ -1974,6 +1974,56 @@ static int __vsock_stream_recvmsg(struct sock *sk, struct msghdr *msg, 
	return err;

}



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

				     size_t len, int flags)

{

	const struct vsock_transport *transport;

	struct vsock_sock *vsk;

	ssize_t record_len;

	long timeout;

	int err = 0;

	DEFINE_WAIT(wait);



	vsk = vsock_sk(sk);

	transport = vsk->transport;



	timeout = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);



	err = vsock_wait_data(sk, &wait, timeout, NULL, 0);

	if (err <= 0)

		goto out;



	record_len = transport->seqpacket_dequeue(vsk, msg, flags);



	if (record_len < 0) {

		err = -ENOMEM;

		goto out;

	}



	if (sk->sk_err) {

		err = -sk->sk_err;

	} else if (sk->sk_shutdown & RCV_SHUTDOWN) {

		err = 0;

	} else {

		/* User sets MSG_TRUNC, so return real length of

		 * packet.

		 */

		if (flags & MSG_TRUNC)

			err = record_len;

		else

			err = len - msg_data_left(msg);



		/* Always set MSG_TRUNC if real length of packet is

		 * bigger than user's buffer.

		 */

		if (record_len > len)

			msg->msg_flags |= MSG_TRUNC;

	}



out:

	return err;

}



static int

vsock_connectible_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,

			  int flags)
@@ -2029,7 +2079,10 @@ vsock_connectible_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, 
		goto out;

	}



	if (sk->sk_type == SOCK_STREAM)

		err = __vsock_stream_recvmsg(sk, msg, len, flags);

	else

		err = __vsock_seqpacket_recvmsg(sk, msg, len, flags);



out:

	release_sock(sk);