Virtualization - Jul 2023 - [RFC PATCH v5 07/17] vsock: read from socket's error queue

On Sat, Jul 01, 2023 at 09:39:37AM +0300, Arseniy Krasnov
wrote:
>This adds handling of MSG_ERRQUEUE input flag in receive call. This flag
>is used to read socket's error queue instead of data queue. Possible
>scenario of error queue usage is receiving completions for transmission
>with MSG_ZEROCOPY flag. This patch also adds 'SOL_VSOCK' define.
>
>Signed-off-by: Arseniy Krasnov <AVKrasnov at sberdevices.ru>
>---
> Changelog:
> v4 -> v5:
>  * Update commit message by adding sentence that 'SOL_VSOCK' is
also
>    added.
Reviewed-by: Stefano Garzarella <sgarzare at redhat.com>
>
> include/linux/socket.h   | 1 +
> net/vmw_vsock/af_vsock.c | 5 +++++
> 2 files changed, 6 insertions(+)
>
>diff --git a/include/linux/socket.h b/include/linux/socket.h
>index bd1cc3238851..d79efd026880 100644
>--- a/include/linux/socket.h
>+++ b/include/linux/socket.h
>@@ -382,6 +382,7 @@ struct ucred {
> #define SOL_MPTCP	284
> #define SOL_MCTP	285
> #define SOL_SMC		286
>+#define SOL_VSOCK	287
>
> /* IPX options */
> #define IPX_TYPE	1
>diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
>index 45fd20c4ed50..07803d9fbf6d 100644
>--- a/net/vmw_vsock/af_vsock.c
>+++ b/net/vmw_vsock/af_vsock.c
>@@ -110,6 +110,7 @@
> #include <linux/workqueue.h>
> #include <net/sock.h>
> #include <net/af_vsock.h>
>+#include <linux/errqueue.h>
>
> static int __vsock_bind(struct sock *sk, struct sockaddr_vm *addr);
> static void vsock_sk_destruct(struct sock *sk);
>@@ -2135,6 +2136,10 @@ vsock_connectible_recvmsg(struct socket *sock, struct
msghdr *msg, size_t len,
> 	int err;
>
> 	sk = sock->sk;
>+
>+	if (unlikely(flags & MSG_ERRQUEUE))
>+		return sock_recv_errqueue(sk, msg, len, SOL_VSOCK, 0);
>+
> 	vsk = vsock_sk(sk);
> 	err = 0;
>
>-- 
>2.25.1
>