[PATCH 1/2] virtio: Introduce VNET_HLEN macro for virtio net header length

[Laurent Vivier <lvivier@redhat.com>]

Replace all open-coded sizeof(struct virtio_net_hdr_mrg_rxbuf) with a
VNET_HLEN macro.

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
---
 tcp_vu.c    | 21 +++++++--------------
 udp_vu.c    | 12 ++++--------
 virtio.h    |  2 ++
 vu_common.c | 13 +++++--------
 vu_common.h |  2 +-
 5 files changed, 19 insertions(+), 31 deletions(-)

diff --git a/tcp_vu.c b/tcp_vu.c
index b9e9b55ed3d3..f7bda4943e43 100644
--- a/tcp_vu.c
+++ b/tcp_vu.c
@@ -49,8 +49,7 @@ static size_t tcp_vu_hdrlen(bool v6)
 {
 	size_t hdrlen;
 
-	hdrlen = sizeof(struct virtio_net_hdr_mrg_rxbuf) +
-		 sizeof(struct ethhdr) + sizeof(struct tcphdr);
+	hdrlen = VNET_HLEN + sizeof(struct ethhdr) + sizeof(struct tcphdr);
 
 	if (v6)
 		hdrlen += sizeof(struct ipv6hdr);
@@ -140,10 +139,8 @@ int tcp_vu_send_flag(const struct ctx *c, struct tcp_tap_conn *conn, int flags)
 
 	vu_pad(&flags_elem[0].in_sg[0], hdrlen + optlen);
 
-	if (*c->pcap) {
-		pcap_iov(&flags_elem[0].in_sg[0], 1,
-			 sizeof(struct virtio_net_hdr_mrg_rxbuf));
-	}
+	if (*c->pcap)
+		pcap_iov(&flags_elem[0].in_sg[0], 1, VNET_HLEN);
 	nb_ack = 1;
 
 	if (flags & DUP_ACK) {
@@ -159,10 +156,8 @@ int tcp_vu_send_flag(const struct ctx *c, struct tcp_tap_conn *conn, int flags)
 			       flags_elem[0].in_sg[0].iov_len);
 			nb_ack++;
 
-			if (*c->pcap) {
-				pcap_iov(&flags_elem[1].in_sg[0], 1,
-					 sizeof(struct virtio_net_hdr_mrg_rxbuf));
-			}
+			if (*c->pcap)
+				pcap_iov(&flags_elem[1].in_sg[0], 1, VNET_HLEN);
 		}
 	}
 
@@ -464,10 +459,8 @@ int tcp_vu_data_from_sock(const struct ctx *c, struct tcp_tap_conn *conn)
 		/* Pad first/single buffer only, it's at least ETH_ZLEN long */
 		vu_pad(iov, dlen + hdrlen);
 
-		if (*c->pcap) {
-			pcap_iov(iov, buf_cnt,
-				 sizeof(struct virtio_net_hdr_mrg_rxbuf));
-		}
+		if (*c->pcap)
+			pcap_iov(iov, buf_cnt, VNET_HLEN);
 
 		conn->seq_to_tap += dlen;
 	}
diff --git a/udp_vu.c b/udp_vu.c
index 3774d538a2d0..4f1eac48d162 100644
--- a/udp_vu.c
+++ b/udp_vu.c
@@ -46,8 +46,7 @@ static size_t udp_vu_hdrlen(bool v6)
 {
 	size_t hdrlen;
 
-	hdrlen = sizeof(struct virtio_net_hdr_mrg_rxbuf) +
-		 sizeof(struct ethhdr) + sizeof(struct udphdr);
+	hdrlen = VNET_HLEN + sizeof(struct ethhdr) + sizeof(struct udphdr);
 
 	if (v6)
 		hdrlen += sizeof(struct ipv6hdr);
@@ -93,9 +92,7 @@ static int udp_vu_sock_recv(const struct ctx *c, struct vu_virtq *vq, int s,
 	vu_init_elem(elem, iov_vu, VIRTQUEUE_MAX_SIZE);
 
 	iov_cnt = vu_collect(vdev, vq, elem, VIRTQUEUE_MAX_SIZE,
-			     IP_MAX_MTU + ETH_HLEN +
-			     sizeof(struct virtio_net_hdr_mrg_rxbuf),
-			     NULL);
+			     IP_MAX_MTU + ETH_HLEN + VNET_HLEN, NULL);
 	if (iov_cnt == 0)
 		return -1;
 
@@ -127,7 +124,7 @@ static int udp_vu_sock_recv(const struct ctx *c, struct vu_virtq *vq, int s,
 	iov_used = idx + !!off;
 
 	/* pad frame to 60 bytes: first buffer is at least ETH_ZLEN long */
-	l2len = *dlen + hdrlen - sizeof(struct virtio_net_hdr_mrg_rxbuf);
+	l2len = *dlen + hdrlen - VNET_HLEN;
 	vu_pad(&iov_vu[0], l2len);
 
 	vu_set_vnethdr(vdev, iov_vu[0].iov_base, iov_used);
@@ -233,8 +230,7 @@ void udp_vu_sock_to_tap(const struct ctx *c, int s, int n, flow_sidx_t tosidx)
 			udp_vu_prepare(c, toside, dlen);
 			if (*c->pcap) {
 				udp_vu_csum(toside, iov_used);
-				pcap_iov(iov_vu, iov_used,
-					sizeof(struct virtio_net_hdr_mrg_rxbuf));
+				pcap_iov(iov_vu, iov_used, VNET_HLEN);
 			}
 			vu_flush(vdev, vq, elem, iov_used);
 		}
diff --git a/virtio.h b/virtio.h
index 12caaa0b6def..d04bbe84e5c4 100644
--- a/virtio.h
+++ b/virtio.h
@@ -15,6 +15,8 @@
 /* Maximum size of a virtqueue */
 #define VIRTQUEUE_MAX_SIZE 1024
 
+#define VNET_HLEN	(sizeof(struct virtio_net_hdr_mrg_rxbuf))
+
 /**
  * struct vu_ring - Virtqueue rings
  * @num:		Size of the queue
diff --git a/vu_common.c b/vu_common.c
index c682498fb555..aa14598ea028 100644
--- a/vu_common.c
+++ b/vu_common.c
@@ -261,7 +261,7 @@ int vu_send_single(const struct ctx *c, const void *buf, size_t size)
 
 	vu_init_elem(elem, in_sg, VIRTQUEUE_MAX_SIZE);
 
-	size += sizeof(struct virtio_net_hdr_mrg_rxbuf);
+	size += VNET_HLEN;
 	elem_cnt = vu_collect(vdev, vq, elem, VIRTQUEUE_MAX_SIZE, size, &total);
 	if (total < size) {
 		debug("vu_send_single: no space to send the data "
@@ -271,16 +271,13 @@ int vu_send_single(const struct ctx *c, const void *buf, size_t size)
 
 	vu_set_vnethdr(vdev, in_sg[0].iov_base, elem_cnt);
 
-	total -= sizeof(struct virtio_net_hdr_mrg_rxbuf);
+	total -= VNET_HLEN;
 
 	/* copy data from the buffer to the iovec */
-	iov_from_buf(in_sg, elem_cnt, sizeof(struct virtio_net_hdr_mrg_rxbuf),
-		     buf, total);
+	iov_from_buf(in_sg, elem_cnt, VNET_HLEN, buf, total);
 
-	if (*c->pcap) {
-		pcap_iov(in_sg, elem_cnt,
-			 sizeof(struct virtio_net_hdr_mrg_rxbuf));
-	}
+	if (*c->pcap)
+		pcap_iov(in_sg, elem_cnt, VNET_HLEN);
 
 	vu_flush(vdev, vq, elem, elem_cnt);
 
diff --git a/vu_common.h b/vu_common.h
index b5112c1e059d..052aff710502 100644
--- a/vu_common.h
+++ b/vu_common.h
@@ -11,7 +11,7 @@
 
 static inline void *vu_eth(void *base)
 {
-	return ((char *)base + sizeof(struct virtio_net_hdr_mrg_rxbuf));
+	return ((char *)base + VNET_HLEN);
 }
 
 static inline void *vu_ip(void *base)
-- 
2.52.0