xen-netfront: use skb_partial_csum_set() to simplify the codes
use skb_partial_csum_set() to simplify the codes
Cc: Jason Wang <jasowang@redhat.com>
Signed-off-by: Li RongQing <roy.qing.li@gmail.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c
index 62238a0..76a2236 100644
--- a/drivers/net/xen-netfront.c
+++ b/drivers/net/xen-netfront.c
@@ -858,7 +858,6 @@
static int checksum_setup(struct net_device *dev, struct sk_buff *skb)
{
struct iphdr *iph;
- unsigned char *th;
int err = -EPROTO;
int recalculate_partial_csum = 0;
@@ -883,27 +882,27 @@
goto out;
iph = (void *)skb->data;
- th = skb->data + 4 * iph->ihl;
- if (th >= skb_tail_pointer(skb))
- goto out;
- skb->csum_start = th - skb->head;
switch (iph->protocol) {
case IPPROTO_TCP:
- skb->csum_offset = offsetof(struct tcphdr, check);
+ if (!skb_partial_csum_set(skb, 4 * iph->ihl,
+ offsetof(struct tcphdr, check)))
+ goto out;
if (recalculate_partial_csum) {
- struct tcphdr *tcph = (struct tcphdr *)th;
+ struct tcphdr *tcph = tcp_hdr(skb);
tcph->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr,
skb->len - iph->ihl*4,
IPPROTO_TCP, 0);
}
break;
case IPPROTO_UDP:
- skb->csum_offset = offsetof(struct udphdr, check);
+ if (!skb_partial_csum_set(skb, 4 * iph->ihl,
+ offsetof(struct udphdr, check)))
+ goto out;
if (recalculate_partial_csum) {
- struct udphdr *udph = (struct udphdr *)th;
+ struct udphdr *udph = udp_hdr(skb);
udph->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr,
skb->len - iph->ihl*4,
IPPROTO_UDP, 0);
@@ -917,9 +916,6 @@
goto out;
}
- if ((th + skb->csum_offset + 2) > skb_tail_pointer(skb))
- goto out;
-
err = 0;
out: