net: Use skb_checksum_start_offset()

Replace skb->csum_start - skb_headroom(skb) with skb_checksum_start_offset().

Note for usb/smsc95xx: skb->data - skb->head == skb_headroom(skb).

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/atlx/atl1.c b/drivers/net/atlx/atl1.c
index 5336310..def8df8 100644 (file)
--- a/drivers/net/atlx/atl1.c
+++ b/drivers/net/atlx/atl1.c
@@ -2174,7 +2174,7 @@ static int atl1_tx_csum(struct atl1_adapter *adapter, struct sk_buff *skb,
        u8 css, cso;
 
        if (likely(skb->ip_summed == CHECKSUM_PARTIAL)) {
-               css = (u8) (skb->csum_start - skb_headroom(skb));
+               css = skb_checksum_start_offset(skb);
                cso = css + (u8) skb->csum_offset;
                if (unlikely(css & 0x1)) {
                        /* L1 hardware requires an even number here */

diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c
index 4256727..21845af 100644 (file)
--- a/drivers/net/macvtap.c
+++ b/drivers/net/macvtap.c
@@ -504,8 +504,7 @@ static int macvtap_skb_to_vnet_hdr(const struct sk_buff *skb,
 
        if (skb->ip_summed == CHECKSUM_PARTIAL) {
                vnet_hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
-               vnet_hdr->csum_start = skb->csum_start -
-                                       skb_headroom(skb);
+               vnet_hdr->csum_start = skb_checksum_start_offset(skb);
                vnet_hdr->csum_offset = skb->csum_offset;
        } /* else everything is zero */
 

diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 55f3a3e..7599c45 100644 (file)
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -757,7 +757,7 @@ static __inline__ ssize_t tun_put_user(struct tun_struct *tun,
 
                if (skb->ip_summed == CHECKSUM_PARTIAL) {
                        gso.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
-                       gso.csum_start = skb->csum_start - skb_headroom(skb);
+                       gso.csum_start = skb_checksum_start_offset(skb);
                        gso.csum_offset = skb->csum_offset;
                } /* else everything is zero */
 

diff --git a/drivers/net/usb/smsc95xx.c b/drivers/net/usb/smsc95xx.c
index 65cb1ab..bc86f4b 100644 (file)
--- a/drivers/net/usb/smsc95xx.c
+++ b/drivers/net/usb/smsc95xx.c
@@ -1163,9 +1163,8 @@ static int smsc95xx_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
 
 static u32 smsc95xx_calc_csum_preamble(struct sk_buff *skb)
 {
-       int len = skb->data - skb->head;
-       u16 high_16 = (u16)(skb->csum_offset + skb->csum_start - len);
-       u16 low_16 = (u16)(skb->csum_start - len);
+       u16 low_16 = (u16)skb_checksum_start_offset(skb);
+       u16 high_16 = low_16 + skb->csum_offset;
        return (high_16 << 16) | low_16;
 }
 
@@ -1193,7 +1192,7 @@ static struct sk_buff *smsc95xx_tx_fixup(struct usbnet *dev,
                if (skb->len <= 45) {
                        /* workaround - hardware tx checksum does not work
                         * properly with extremely small packets */
-                       long csstart = skb->csum_start - skb_headroom(skb);
+                       long csstart = skb_checksum_start_offset(skb);
                        __wsum calc = csum_partial(skb->data + csstart,
                                skb->len - csstart, 0);
                        *((__sum16 *)(skb->data + csstart

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index b6d4028..90a23e4 100644 (file)
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -519,7 +519,7 @@ static int xmit_skb(struct virtnet_info *vi, struct sk_buff *skb)
 
        if (skb->ip_summed == CHECKSUM_PARTIAL) {
                hdr->hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
-               hdr->hdr.csum_start = skb->csum_start - skb_headroom(skb);
+               hdr->hdr.csum_start = skb_checksum_start_offset(skb);
                hdr->hdr.csum_offset = skb->csum_offset;
        } else {
                hdr->hdr.flags = 0;

diff --git a/net/core/dev.c b/net/core/dev.c
index 794b20d..92d414a 100644 (file)
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1793,7 +1793,7 @@ int skb_checksum_help(struct sk_buff *skb)
                goto out_set_summed;
        }
 
-       offset = skb->csum_start - skb_headroom(skb);
+       offset = skb_checksum_start_offset(skb);
        BUG_ON(offset >= skb_headlen(skb));
        csum = skb_checksum(skb, offset, skb->len - offset, 0);
 
@@ -2090,8 +2090,8 @@ int dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev,
                         * checksumming here.
                         */
                        if (skb->ip_summed == CHECKSUM_PARTIAL) {
-                               skb_set_transport_header(skb, skb->csum_start -
-                                             skb_headroom(skb));
+                               skb_set_transport_header(skb,
+                                       skb_checksum_start_offset(skb));
                                if (!dev_can_checksum(dev, skb) &&
                                     skb_checksum_help(skb))
                                        goto out_kfree_skb;

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 8814a9a..19d6c21 100644 (file)
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -1824,7 +1824,7 @@ void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to)
        long csstart;
 
        if (skb->ip_summed == CHECKSUM_PARTIAL)
-               csstart = skb->csum_start - skb_headroom(skb);
+               csstart = skb_checksum_start_offset(skb);
        else
                csstart = skb_headlen(skb);
 

diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index b37181d..1198adf 100644 (file)
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -2226,7 +2226,7 @@ struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb, int features)
        /* Do software UFO. Complete and fill in the UDP checksum as HW cannot
         * do checksum of UDP packets sent as multiple IP fragments.
         */
-       offset = skb->csum_start - skb_headroom(skb);
+       offset = skb_checksum_start_offset(skb);
        csum = skb_checksum(skb, offset, skb->len - offset, 0);
        offset += skb->csum_offset;
        *(__sum16 *)(skb->data + offset) = csum_fold(csum);

diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index e79efaf..91cb1d7 100644 (file)
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -1650,8 +1650,7 @@ static int packet_recvmsg(struct kiocb *iocb, struct socket *sock,
 
                if (skb->ip_summed == CHECKSUM_PARTIAL) {
                        vnet_hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
-                       vnet_hdr.csum_start = skb->csum_start -
-                                                       skb_headroom(skb);
+                       vnet_hdr.csum_start = skb_checksum_start_offset(skb);
                        vnet_hdr.csum_offset = skb->csum_offset;
                } /* else everything is zero */