virtio_net: formalize skb_vnet_hdr
We put the virtio_net_hdr into the skb's cb region; turn this into a
union to clean up the code slightly and allow future expansion.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Mark McLoughlin <markmc@redhat.com>
Cc: Dinesh Subhraveti <dineshs@us.ibm.com>
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 3041e4e..420388a 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -68,9 +68,16 @@
struct page *pages;
};
-static inline void *skb_vnet_hdr(struct sk_buff *skb)
+struct skb_vnet_hdr {
+ union {
+ struct virtio_net_hdr hdr;
+ struct virtio_net_hdr_mrg_rxbuf mhdr;
+ };
+};
+
+static inline struct skb_vnet_hdr *skb_vnet_hdr(struct sk_buff *skb)
{
- return (struct virtio_net_hdr *)skb->cb;
+ return (struct skb_vnet_hdr *)skb->cb;
}
static void give_a_page(struct virtnet_info *vi, struct page *page)
@@ -115,7 +122,7 @@
unsigned len)
{
struct virtnet_info *vi = netdev_priv(dev);
- struct virtio_net_hdr *hdr = skb_vnet_hdr(skb);
+ struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb);
int err;
int i;
@@ -126,7 +133,6 @@
}
if (vi->mergeable_rx_bufs) {
- struct virtio_net_hdr_mrg_rxbuf *mhdr = skb_vnet_hdr(skb);
unsigned int copy;
char *p = page_address(skb_shinfo(skb)->frags[0].page);
@@ -134,8 +140,8 @@
len = PAGE_SIZE;
len -= sizeof(struct virtio_net_hdr_mrg_rxbuf);
- memcpy(hdr, p, sizeof(*mhdr));
- p += sizeof(*mhdr);
+ memcpy(&hdr->mhdr, p, sizeof(hdr->mhdr));
+ p += sizeof(hdr->mhdr);
copy = len;
if (copy > skb_tailroom(skb))
@@ -150,13 +156,13 @@
skb_shinfo(skb)->nr_frags--;
} else {
skb_shinfo(skb)->frags[0].page_offset +=
- sizeof(*mhdr) + copy;
+ sizeof(hdr->mhdr) + copy;
skb_shinfo(skb)->frags[0].size = len;
skb->data_len += len;
skb->len += len;
}
- while (--mhdr->num_buffers) {
+ while (--hdr->mhdr.num_buffers) {
struct sk_buff *nskb;
i = skb_shinfo(skb)->nr_frags;
@@ -170,7 +176,7 @@
nskb = vi->rvq->vq_ops->get_buf(vi->rvq, &len);
if (!nskb) {
pr_debug("%s: rx error: %d buffers missing\n",
- dev->name, mhdr->num_buffers);
+ dev->name, hdr->mhdr.num_buffers);
dev->stats.rx_length_errors++;
goto drop;
}
@@ -191,7 +197,7 @@
skb->len += len;
}
} else {
- len -= sizeof(struct virtio_net_hdr);
+ len -= sizeof(hdr->hdr);
if (len <= MAX_PACKET_LEN)
trim_pages(vi, skb);
@@ -209,9 +215,11 @@
dev->stats.rx_bytes += skb->len;
dev->stats.rx_packets++;
- if (hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
+ if (hdr->hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
pr_debug("Needs csum!\n");
- if (!skb_partial_csum_set(skb,hdr->csum_start,hdr->csum_offset))
+ if (!skb_partial_csum_set(skb,
+ hdr->hdr.csum_start,
+ hdr->hdr.csum_offset))
goto frame_err;
}
@@ -219,9 +227,9 @@
pr_debug("Receiving skb proto 0x%04x len %i type %i\n",
ntohs(skb->protocol), skb->len, skb->pkt_type);
- if (hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) {
+ if (hdr->hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
pr_debug("GSO!\n");
- switch (hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
+ switch (hdr->hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
case VIRTIO_NET_HDR_GSO_TCPV4:
skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
break;
@@ -234,14 +242,14 @@
default:
if (net_ratelimit())
printk(KERN_WARNING "%s: bad gso type %u.\n",
- dev->name, hdr->gso_type);
+ dev->name, hdr->hdr.gso_type);
goto frame_err;
}
- if (hdr->gso_type & VIRTIO_NET_HDR_GSO_ECN)
+ if (hdr->hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN)
skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
- skb_shinfo(skb)->gso_size = hdr->gso_size;
+ skb_shinfo(skb)->gso_size = hdr->hdr.gso_size;
if (skb_shinfo(skb)->gso_size == 0) {
if (net_ratelimit())
printk(KERN_WARNING "%s: zero gso size.\n",
@@ -272,7 +280,7 @@
sg_init_table(sg, 2+MAX_SKB_FRAGS);
for (;;) {
- struct virtio_net_hdr *hdr;
+ struct skb_vnet_hdr *hdr;
skb = netdev_alloc_skb(vi->dev, MAX_PACKET_LEN + NET_IP_ALIGN);
if (unlikely(!skb)) {
@@ -284,7 +292,7 @@
skb_put(skb, MAX_PACKET_LEN);
hdr = skb_vnet_hdr(skb);
- sg_set_buf(sg, hdr, sizeof(*hdr));
+ sg_set_buf(sg, &hdr->hdr, sizeof(hdr->hdr));
if (vi->big_packets) {
for (i = 0; i < MAX_SKB_FRAGS; i++) {
@@ -452,8 +460,7 @@
{
int num;
struct scatterlist sg[2+MAX_SKB_FRAGS];
- struct virtio_net_hdr_mrg_rxbuf *mhdr = skb_vnet_hdr(skb);
- struct virtio_net_hdr *hdr = skb_vnet_hdr(skb);
+ struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb);
const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
sg_init_table(sg, 2+MAX_SKB_FRAGS);
@@ -461,39 +468,39 @@
pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest);
if (skb->ip_summed == CHECKSUM_PARTIAL) {
- hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
- hdr->csum_start = skb->csum_start - skb_headroom(skb);
- hdr->csum_offset = skb->csum_offset;
+ hdr->hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
+ hdr->hdr.csum_start = skb->csum_start - skb_headroom(skb);
+ hdr->hdr.csum_offset = skb->csum_offset;
} else {
- hdr->flags = 0;
- hdr->csum_offset = hdr->csum_start = 0;
+ hdr->hdr.flags = 0;
+ hdr->hdr.csum_offset = hdr->hdr.csum_start = 0;
}
if (skb_is_gso(skb)) {
- hdr->hdr_len = skb_headlen(skb);
- hdr->gso_size = skb_shinfo(skb)->gso_size;
+ hdr->hdr.hdr_len = skb_headlen(skb);
+ hdr->hdr.gso_size = skb_shinfo(skb)->gso_size;
if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
- hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
+ hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
- hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
+ hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
else if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
- hdr->gso_type = VIRTIO_NET_HDR_GSO_UDP;
+ hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP;
else
BUG();
if (skb_shinfo(skb)->gso_type & SKB_GSO_TCP_ECN)
- hdr->gso_type |= VIRTIO_NET_HDR_GSO_ECN;
+ hdr->hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
} else {
- hdr->gso_type = VIRTIO_NET_HDR_GSO_NONE;
- hdr->gso_size = hdr->hdr_len = 0;
+ hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE;
+ hdr->hdr.gso_size = hdr->hdr.hdr_len = 0;
}
- mhdr->num_buffers = 0;
+ hdr->mhdr.num_buffers = 0;
/* Encode metadata header at front. */
if (vi->mergeable_rx_bufs)
- sg_set_buf(sg, mhdr, sizeof(*mhdr));
+ sg_set_buf(sg, &hdr->mhdr, sizeof(hdr->mhdr));
else
- sg_set_buf(sg, hdr, sizeof(*hdr));
+ sg_set_buf(sg, &hdr->hdr, sizeof(hdr->hdr));
num = skb_to_sgvec(skb, sg+1, 0, skb->len) + 1;
return vi->svq->vq_ops->add_buf(vi->svq, sg, num, 0, skb);