[PATCH 1/7] tap: Move the tap_hdr file to a separate file

[aerosouund <aerosound161@gmail.com>]

From: Ammar Yasser <aerosound161@gmail.com>

It was defined in tap.h, put it on its own so that future callers won't
need to depend on all definitions in tap.h.
Also turn it into a union of a vnet_len and virtio_net_mrg_rxbuf
because for vhost acceleration the frames will have this virtio net
header prepended to them.

Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
Signed-off-by: Ammar Yasser <aerosound161@gmail.com>
---
 tap.h     |  9 +--------
 tap_hdr.h | 23 +++++++++++++++++++++++
 2 files changed, 24 insertions(+), 8 deletions(-)
 create mode 100644 tap_hdr.h

diff --git a/tap.h b/tap.h
index b335933..1625975 100644
--- a/tap.h
+++ b/tap.h
@@ -10,6 +10,7 @@
 #include <stdint.h>
 
 #include "passt.h"
+#include "tap_hdr.h"
 
 /** L2_MAX_LEN_PASTA - Maximum frame length for pasta mode (with L2 header)
  *
@@ -38,14 +39,6 @@
 
 struct udphdr;
 
-/**
- * struct tap_hdr - tap backend specific headers
- * @vnet_len:	Frame length (for qemu socket transport)
- */
-struct tap_hdr {
-	uint32_t vnet_len;
-} __attribute__((packed));
-
 /**
  * tap_hdr_iov() - struct iovec for a tap header
  * @c:		Execution context
diff --git a/tap_hdr.h b/tap_hdr.h
new file mode 100644
index 0000000..aa270b7
--- /dev/null
+++ b/tap_hdr.h
@@ -0,0 +1,23 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later
+ * Copyright (c) 2021 Red Hat GmbH
+ * Author: Stefano Brivio <sbrivio@redhat.com>
+ */
+
+#ifndef TAP_HDR_H
+#define TAP_HDR_H
+
+#include <stdint.h>
+#include <linux/virtio_net.h>
+
+/**
+ * struct tap_hdr - tap backend specific headers
+ * @vnet_len:	Frame length (for qemu socket transport)
+ */
+struct tap_hdr {
+	union {
+		uint32_t vnet_len;
+		struct virtio_net_hdr_mrg_rxbuf hdr;
+	};
+};
+
+#endif /* TAP_HDR_H */
-- 
2.39.5 (Apple Git-154)