vsock: Add support for SIOCINQ ioctl

Add support for SIOCINQ ioctl, indicating the length of bytes unread in the
socket. The value is obtained from `vsock_stream_has_data()`.

Signed-off-by: Xuewei Niu <niuxuewei.nxw@antgroup.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Luigi Leonardi <leonardi@redhat.com>
Link: https://patch.msgid.link/20250708-siocinq-v6-2-3775f9a9e359@antgroup.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
index 2e7a3034e965db30b6ee295370d866e6d8b1c341..bae6b89bb5fb7dd7a3a378f92097561a98a0c814 100644 (file)
--- a/net/vmw_vsock/af_vsock.c
+++ b/net/vmw_vsock/af_vsock.c
@@ -1389,6 +1389,28 @@ static int vsock_do_ioctl(struct socket *sock, unsigned int cmd,
        vsk = vsock_sk(sk);
 
        switch (cmd) {
+       case SIOCINQ: {
+               ssize_t n_bytes;
+
+               if (!vsk->transport) {
+                       ret = -EOPNOTSUPP;
+                       break;
+               }
+
+               if (sock_type_connectible(sk->sk_type) &&
+                   sk->sk_state == TCP_LISTEN) {
+                       ret = -EINVAL;
+                       break;
+               }
+
+               n_bytes = vsock_stream_has_data(vsk);
+               if (n_bytes < 0) {
+                       ret = n_bytes;
+                       break;
+               }
+               ret = put_user(n_bytes, arg);
+               break;
+       }
        case SIOCOUTQ: {
                ssize_t n_bytes;