On Sun, Mar 07, 2021 at 08:59:45PM +0300, Arseny Krasnov wrote:
This adds receive loop for SEQPACKET. It looks like receive loop for
STREAM, but there is a little bit difference:
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 or error is found during
receiving.
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: Arseny Krasnov <arseny.krasnov@xxxxxxxxxxxxx>
---
include/net/af_vsock.h | 5 +++
net/vmw_vsock/af_vsock.c | 95 +++++++++++++++++++++++++++++++++++++++-
2 files changed, 99 insertions(+), 1 deletion(-)
diff --git a/include/net/af_vsock.h b/include/net/af_vsock.h
index b1c717286993..5ad7ee7f78fd 100644
--- a/include/net/af_vsock.h
+++ b/include/net/af_vsock.h
@@ -135,6 +135,11 @@ struct vsock_transport {
bool (*stream_is_active)(struct vsock_sock *);
bool (*stream_allow)(u32 cid, u32 port);
+ /* SEQ_PACKET. */
+ size_t (*seqpacket_seq_get_len)(struct vsock_sock *vsk);
+ int (*seqpacket_dequeue)(struct vsock_sock *vsk, struct msghdr *msg,
+ int flags, bool *msg_ready);
+
/* Notification. */
int (*notify_poll_in)(struct vsock_sock *, size_t, bool *);
int (*notify_poll_out)(struct vsock_sock *, size_t, bool *);
diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
index 0bc661e54262..ac2f69362f2e 100644
--- a/net/vmw_vsock/af_vsock.c
+++ b/net/vmw_vsock/af_vsock.c
@@ -1973,6 +1973,96 @@ 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;
+ const struct iovec *orig_iov;
+ unsigned long orig_nr_segs;
+ bool msg_ready;
+ struct vsock_sock *vsk;
+ size_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);
+ orig_nr_segs = msg->msg_iter.nr_segs;
+ orig_iov = msg->msg_iter.iov;
+ msg_ready = false;
+ record_len = 0;
+
+ while (1) {
+ err = vsock_wait_data(sk, &wait, timeout, NULL, 0);
+
+ if (err <= 0) {
+ /* In case of any loop break(timeout, signal
+ * interrupt or shutdown), we report user that
+ * nothing was copied.
+ */
+ err = 0;
+ break;
+ }
+
+ if (record_len == 0) {
+ record_len =
+ transport->seqpacket_seq_get_len(vsk);
+
+ if (record_len == 0)
+ continue;
+ }
+
+ err = transport->seqpacket_dequeue(vsk, msg, flags, &msg_ready);
In order to simplify the transport interface, can we do the work of
seqpacket_seq_get_len() at the beginning of seqpacket_dequeue()?
So in this way seqpacket_dequeue() can return the 'record_len' or an
error.
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