[RFC PATCH v7 06/22] af_vsock: implement send logic for SEQPACKET

Arseny Krasnov
2021-03-23T13:11:45Z

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@kaspersky.com>
---
v6 -> v7:
'seqpacket_enqueue' callback interface changed, 'flags' argument was
removed, because it was 'msg_flags' field of 'msg' argument which is
already exists.

include/net/af_vsock.h | 2 ++
net/vmw_vsock/af_vsock.c | 21 +++++++++++++++------
2 files changed, 17 insertions(+), 6 deletions(-)

diff --git a/include/net/af_vsock.h b/include/net/af_vsock.h
index 7232f6c42a36..b7063820d0bc 100644
--- a/include/net/af_vsock.h
+++ b/include/net/af_vsock.h
@@ -138,6 +138,8 @@ struct vsock_transport {
/* SEQ_PACKET. */
int (*seqpacket_dequeue)(struct vsock_sock *vsk, struct msghdr *msg,
int flags, bool *msg_ready, size_t *record_len);
+ 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 617ffe42693d..a98e5daa06b7 100644
--- a/net/vmw_vsock/af_vsock.c
+++ b/net/vmw_vsock/af_vsock.c
@@ -1830,9 +1830,13 @@ 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;
@@ -1844,12 +1848,17 @@ static int vsock_connectible_sendmsg(struct socket *sock, struct msghdr *msg,
vsk, written, &send_data);
if (err < 0)
goto out_err;
-
}

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