[RFC PATCH v9 05/19] af_vsock: implement send logic for SEQPACKET

From: Arseny Krasnov
Date: Sat May 08 2021 - 12:33:55 EST


This adds some logic to current stream enqueue function for SEQPACKET
support:
1) Use transport's seqpacket enqueue callback.
2) Return value from enqueue function is whole record length or error
for SOCK_SEQPACKET.

Signed-off-by: Arseny Krasnov <arseny.krasnov@xxxxxxxxxxxxx>
Reviewed-by: Stefano Garzarella <sgarzare@xxxxxxxxxx>
---
include/net/af_vsock.h | 2 ++
net/vmw_vsock/af_vsock.c | 20 +++++++++++++++-----
2 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/include/net/af_vsock.h b/include/net/af_vsock.h
index 5175f5a52ce1..5860027d5173 100644
--- a/include/net/af_vsock.h
+++ b/include/net/af_vsock.h
@@ -138,6 +138,8 @@ struct vsock_transport {
/* SEQ_PACKET. */
ssize_t (*seqpacket_dequeue)(struct vsock_sock *vsk, struct msghdr *msg,
int flags, bool *msg_ready);
+ int (*seqpacket_enqueue)(struct vsock_sock *vsk, struct msghdr *msg,
+ size_t len);

/* Notification. */
int (*notify_poll_in)(struct vsock_sock *, size_t, bool *);
diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
index 78b9af545ca8..3f9cfcce1e42 100644
--- a/net/vmw_vsock/af_vsock.c
+++ b/net/vmw_vsock/af_vsock.c
@@ -1808,9 +1808,13 @@ static int vsock_connectible_sendmsg(struct socket *sock, struct msghdr *msg,
* responsibility to check how many bytes we were able to send.
*/

- written = transport->stream_enqueue(
- vsk, msg,
- len - total_written);
+ if (sk->sk_type == SOCK_SEQPACKET) {
+ written = transport->seqpacket_enqueue(vsk,
+ msg, len - total_written);
+ } else {
+ written = transport->stream_enqueue(vsk,
+ msg, len - total_written);
+ }
if (written < 0) {
err = -ENOMEM;
goto out_err;
@@ -1826,8 +1830,14 @@ static int vsock_connectible_sendmsg(struct socket *sock, struct msghdr *msg,
}

out_err:
- if (total_written > 0)
- err = total_written;
+ if (total_written > 0) {
+ /* Return number of written bytes only if:
+ * 1) SOCK_STREAM socket.
+ * 2) SOCK_SEQPACKET socket when whole buffer is sent.
+ */
+ if (sk->sk_type == SOCK_STREAM || total_written == len)
+ err = total_written;
+ }
out:
release_sock(sk);
return err;
--
2.25.1