[SK_BUFF]: Introduce skb_set_mac_header()

For the cases where we want to set skb->mac.raw to an offset from skb->data.

Simple cases first, the memmove ones and specially pktgen will be left for later.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

6 files changed, 11 insertions, 6 deletions

diff --git a/drivers/net/loopback.c b/drivers/net/loopback.c
index 4380e5e89dc9..a71d8e0a9b57 100644
--- a/drivers/net/loopback.c
+++ b/drivers/net/loopback.c
@@ -90,7 +90,7 @@ static void emulate_large_send_offload(struct sk_buff *skb)
                 if (!nskb)
                         break;
                 skb_reserve(nskb, 32);
-                nskb->mac.raw = nskb->data - 14;
+                skb_set_mac_header(nskb, -ETH_HLEN);
                 nskb->nh.raw = nskb->data;
                 iph = nskb->nh.iph;
                 memcpy(nskb->data, skb->nh.raw, doffset);
diff --git a/drivers/net/myri_sbus.c b/drivers/net/myri_sbus.c
index de092658db6c..e1f16fb05846 100644
--- a/drivers/net/myri_sbus.c
+++ b/drivers/net/myri_sbus.c
@@ -368,7 +368,7 @@ static __be16 myri_type_trans(struct sk_buff *skb, struct net_device *dev)
         struct ethhdr *eth;
         unsigned char *rawp;
 
-        skb->mac.raw = skb->data + MYRI_PAD_LEN;
+        skb_set_mac_header(skb, MYRI_PAD_LEN);
         skb_pull(skb, dev->hard_header_len);
         eth = eth_hdr(skb);
 
diff --git a/drivers/s390/net/qeth_eddp.c b/drivers/s390/net/qeth_eddp.c
index 910a8ab66b05..893125403c68 100644
--- a/drivers/s390/net/qeth_eddp.c
+++ b/drivers/s390/net/qeth_eddp.c
@@ -486,7 +486,7 @@ qeth_eddp_fill_context_tcp(struct qeth_eddp_context *ctx,
                 return -ENOMEM;
         }
         if (qhdr->hdr.l2.id == QETH_HEADER_TYPE_LAYER2) {
-                skb->mac.raw = skb->data + sizeof(struct qeth_hdr);
+                skb_set_mac_header(skb, sizeof(struct qeth_hdr));
                 memcpy(&eddp->mac, eth_hdr(skb), ETH_HLEN);
 #ifdef CONFIG_QETH_VLAN
                 if (eddp->mac.h_proto == __constant_htons(ETH_P_8021Q)) {
diff --git a/drivers/s390/net/qeth_main.c b/drivers/s390/net/qeth_main.c
index 28822025b791..c0ee6d94ea38 100644
--- a/drivers/s390/net/qeth_main.c
+++ b/drivers/s390/net/qeth_main.c
@@ -2306,7 +2306,7 @@ qeth_rebuild_skb_fake_ll_tr(struct qeth_card *card, struct sk_buff *skb,
         struct iphdr *ip_hdr;
 
         QETH_DBF_TEXT(trace,5,"skbfktr");
-        skb->mac.raw = skb->data - QETH_FAKE_LL_LEN_TR;
+        skb_set_mac_header(skb, -QETH_FAKE_LL_LEN_TR);
         /* this is a fake ethernet header */
         fake_hdr = tr_hdr(skb);
 
@@ -2359,7 +2359,7 @@ qeth_rebuild_skb_fake_ll_eth(struct qeth_card *card, struct sk_buff *skb,
         struct iphdr *ip_hdr;
 
         QETH_DBF_TEXT(trace,5,"skbfketh");
-        skb->mac.raw = skb->data - QETH_FAKE_LL_LEN_ETH;
+        skb_set_mac_header(skb, -QETH_FAKE_LL_LEN_ETH);
         /* this is a fake ethernet header */
         fake_hdr = eth_hdr(skb);
 
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 748f254b50cc..43ab6cbf8446 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -965,6 +965,11 @@ static inline void skb_reset_mac_header(struct sk_buff *skb)
         skb->mac.raw = skb->data;
 }
 
+static inline void skb_set_mac_header(struct sk_buff *skb, const int offset)
+{
+        skb->mac.raw = skb->data + offset;
+}
+
 /*
  * CPUs often take a performance hit when accessing unaligned memory
  * locations. The actual performance hit varies, it can be small if the
diff --git a/net/atm/br2684.c b/net/atm/br2684.c
index 900d42ca8a50..a1686dfcbb9a 100644
--- a/net/atm/br2684.c
+++ b/net/atm/br2684.c
@@ -458,7 +458,7 @@ static void br2684_push(struct atm_vcc *atmvcc, struct sk_buff *skb)
         /* FIXME: tcpdump shows that pointer to mac header is 2 bytes earlier,
            than should be. What else should I set? */
         skb_pull(skb, plen);
-        skb->mac.raw = skb->data - ETH_HLEN;
+        skb_set_mac_header(skb, -ETH_HLEN);
         skb->pkt_type = PACKET_HOST;
 #ifdef CONFIG_BR2684_FAST_TRANS
         skb->protocol = ((u16 *) skb->data)[-1];