[NET]: Wrap netdevice hardware header creation.

Add inline for common usage of hardware header creation, and
fix bug in IPV6 mcast where the assumption about negative return is
an errno. Negative return from hard_header means not enough space
was available,(ie -N bytes).

Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/hamradio/bpqether.c b/drivers/net/hamradio/bpqether.c
index c05bc37..4bff23e 100644
--- a/drivers/net/hamradio/bpqether.c
+++ b/drivers/net/hamradio/bpqether.c
@@ -286,7 +286,7 @@
 
 	skb->protocol = ax25_type_trans(skb, dev);
 	skb_reset_network_header(skb);
-	dev->hard_header(skb, dev, ETH_P_BPQ, bpq->dest_addr, NULL, 0);
+	dev_hard_header(skb, dev, ETH_P_BPQ, bpq->dest_addr, NULL, 0);
 	bpq->stats.tx_packets++;
 	bpq->stats.tx_bytes+=skb->len;
   
diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c
index 2f6cdaa..a22087c 100644
--- a/drivers/net/macvlan.c
+++ b/drivers/net/macvlan.c
@@ -170,8 +170,8 @@
 	const struct macvlan_dev *vlan = netdev_priv(dev);
 	struct net_device *lowerdev = vlan->lowerdev;
 
-	return lowerdev->hard_header(skb, lowerdev, type, daddr,
-				     saddr ? : dev->dev_addr, len);
+	return dev_hard_header(skb, lowerdev, type, daddr,
+			       saddr ? : dev->dev_addr, len);
 }
 
 static int macvlan_open(struct net_device *dev)
diff --git a/drivers/net/pppoe.c b/drivers/net/pppoe.c
index d48b7b7..8936ed3 100644
--- a/drivers/net/pppoe.c
+++ b/drivers/net/pppoe.c
@@ -834,8 +834,8 @@
 	}
 
 	error = total_len;
-	dev->hard_header(skb, dev, ETH_P_PPP_SES,
-			 po->pppoe_pa.remote, NULL, total_len);
+	dev_hard_header(skb, dev, ETH_P_PPP_SES,
+			po->pppoe_pa.remote, NULL, total_len);
 
 	memcpy(ph, &hdr, sizeof(struct pppoe_hdr));
 
@@ -886,8 +886,8 @@
 	skb->protocol = __constant_htons(ETH_P_PPP_SES);
 	skb->dev = dev;
 
-	dev->hard_header(skb, dev, ETH_P_PPP_SES,
-			 po->pppoe_pa.remote, NULL, data_len);
+	dev_hard_header(skb, dev, ETH_P_PPP_SES,
+			po->pppoe_pa.remote, NULL, data_len);
 
 	dev_queue_xmit(skb);
 
diff --git a/drivers/net/wan/lapbether.c b/drivers/net/wan/lapbether.c
index 36e683c..fb37b80 100644
--- a/drivers/net/wan/lapbether.c
+++ b/drivers/net/wan/lapbether.c
@@ -216,7 +216,7 @@
 
 	skb->dev = dev = lapbeth->ethdev;
 
-	dev->hard_header(skb, dev, ETH_P_DEC, bcast_addr, NULL, 0);
+	dev_hard_header(skb, dev, ETH_P_DEC, bcast_addr, NULL, 0);
 
 	dev_queue_xmit(skb);
 }
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 71cf409..b33d084 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -800,6 +800,15 @@
 extern int		netpoll_trap(void);
 #endif
 
+static inline int dev_hard_header(struct sk_buff *skb, struct net_device *dev,
+				  unsigned short type,
+				  void *daddr, void *saddr, unsigned len)
+{
+	if (!dev->hard_header)
+		return 0;
+	return dev->hard_header(skb, dev, type, daddr, saddr, len);
+}
+
 typedef int gifconf_func_t(struct net_device * dev, char __user * bufptr, int len);
 extern int		register_gifconf(unsigned int family, gifconf_func_t * gifconf);
 static inline int unregister_gifconf(unsigned int family)
diff --git a/include/net/dn_route.h b/include/net/dn_route.h
index c10e8e7..60c9f22 100644
--- a/include/net/dn_route.h
+++ b/include/net/dn_route.h
@@ -100,8 +100,7 @@
 	if ((dev->type != ARPHRD_ETHER) && (dev->type != ARPHRD_LOOPBACK))
 		dst = NULL;
 
-	if (!dev->hard_header || (dev->hard_header(skb, dev, ETH_P_DNA_RT,
-			dst, src, skb->len) >= 0))
+	if (dev_hard_header(skb, dev, ETH_P_DNA_RT, dst, src, skb->len) >= 0)
 		dn_rt_send(skb);
 	else
 		kfree_skb(skb);
diff --git a/net/802/p8023.c b/net/802/p8023.c
index 53cf057..6ab1835 100644
--- a/net/802/p8023.c
+++ b/net/802/p8023.c
@@ -31,7 +31,7 @@
 {
 	struct net_device *dev = skb->dev;
 
-	dev->hard_header(skb, dev, ETH_P_802_3, dest_node, NULL, skb->len);
+	dev_hard_header(skb, dev, ETH_P_802_3, dest_node, NULL, skb->len);
 	return dev_queue_xmit(skb);
 }
 
diff --git a/net/8021q/vlan_dev.c b/net/8021q/vlan_dev.c
index 6644e8f..ca8090f 100644
--- a/net/8021q/vlan_dev.c
+++ b/net/8021q/vlan_dev.c
@@ -434,21 +434,19 @@
 
 	if (build_vlan_header) {
 		/* Now make the underlying real hard header */
-		rc = dev->hard_header(skb, dev, ETH_P_8021Q, daddr, saddr, len + VLAN_HLEN);
-
-		if (rc > 0) {
+		rc = dev_hard_header(skb, dev, ETH_P_8021Q, daddr, saddr,
+				     len + VLAN_HLEN);
+		if (rc > 0)
 			rc += VLAN_HLEN;
-		} else if (rc < 0) {
+		else if (rc < 0)
 			rc -= VLAN_HLEN;
-		}
-	} else {
+	} else
 		/* If here, then we'll just make a normal looking ethernet frame,
 		 * but, the hard_start_xmit method will insert the tag (it has to
 		 * be able to do this for bridged and other skbs that don't come
 		 * down the protocol stack in an orderly manner.
 		 */
-		rc = dev->hard_header(skb, dev, type, daddr, saddr, len);
-	}
+		rc = dev_hard_header(skb, dev, type, daddr, saddr, len);
 
 	return rc;
 }
diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index 2c6577c..10bcb9f 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -1125,9 +1125,8 @@
 
 	__skb_pull(skb, skb_network_offset(skb));
 
-	if (dev->hard_header &&
-	    dev->hard_header(skb, dev, ntohs(skb->protocol), NULL, NULL,
-			     skb->len) < 0 &&
+	if (dev_hard_header(skb, dev, ntohs(skb->protocol), NULL, NULL,
+			    skb->len) < 0 &&
 	    dev->rebuild_header(skb))
 		return 0;
 
@@ -1154,13 +1153,13 @@
 			write_lock_bh(&neigh->lock);
 			if (!dst->hh)
 				neigh_hh_init(neigh, dst, dst->ops->protocol);
-			err = dev->hard_header(skb, dev, ntohs(skb->protocol),
-					       neigh->ha, NULL, skb->len);
+			err = dev_hard_header(skb, dev, ntohs(skb->protocol),
+					      neigh->ha, NULL, skb->len);
 			write_unlock_bh(&neigh->lock);
 		} else {
 			read_lock_bh(&neigh->lock);
-			err = dev->hard_header(skb, dev, ntohs(skb->protocol),
-					       neigh->ha, NULL, skb->len);
+			err = dev_hard_header(skb, dev, ntohs(skb->protocol),
+					      neigh->ha, NULL, skb->len);
 			read_unlock_bh(&neigh->lock);
 		}
 		if (err >= 0)
@@ -1191,8 +1190,8 @@
 	__skb_pull(skb, skb_network_offset(skb));
 
 	read_lock_bh(&neigh->lock);
-	err = dev->hard_header(skb, dev, ntohs(skb->protocol),
-			       neigh->ha, NULL, skb->len);
+	err = dev_hard_header(skb, dev, ntohs(skb->protocol),
+			      neigh->ha, NULL, skb->len);
 	read_unlock_bh(&neigh->lock);
 	if (err >= 0)
 		err = neigh->ops->queue_xmit(skb);
diff --git a/net/core/netpoll.c b/net/core/netpoll.c
index e13602d..95daba6 100644
--- a/net/core/netpoll.c
+++ b/net/core/netpoll.c
@@ -415,11 +415,9 @@
 	send_skb->protocol = htons(ETH_P_ARP);
 
 	/* Fill the device header for the ARP frame */
-
-	if (np->dev->hard_header &&
-	    np->dev->hard_header(send_skb, skb->dev, ptype,
-				 sha, np->local_mac,
-				 send_skb->len) < 0) {
+	if (dev_hard_header(send_skb, skb->dev, ptype,
+			    sha, np->local_mac,
+			    send_skb->len) < 0) {
 		kfree_skb(send_skb);
 		return;
 	}
diff --git a/net/decnet/dn_neigh.c b/net/decnet/dn_neigh.c
index a424a8d..b66e3be 100644
--- a/net/decnet/dn_neigh.c
+++ b/net/decnet/dn_neigh.c
@@ -211,7 +211,8 @@
 	char mac_addr[ETH_ALEN];
 
 	dn_dn2eth(mac_addr, rt->rt_local_src);
-	if (!dev->hard_header || dev->hard_header(skb, dev, ntohs(skb->protocol), neigh->ha, mac_addr, skb->len) >= 0)
+	if (dev_hard_header(skb, dev, ntohs(skb->protocol), neigh->ha,
+			    mac_addr, skb->len) >= 0)
 		return neigh->ops->queue_xmit(skb);
 
 	if (net_ratelimit())
diff --git a/net/econet/af_econet.c b/net/econet/af_econet.c
index 9938e76..9cae16b 100644
--- a/net/econet/af_econet.c
+++ b/net/econet/af_econet.c
@@ -336,6 +336,7 @@
 		/* Real hardware Econet.  We're not worthy etc. */
 #ifdef CONFIG_ECONET_NATIVE
 		unsigned short proto = 0;
+		int res;
 
 		dev_hold(dev);
 
@@ -354,12 +355,12 @@
 		eb->sec = *saddr;
 		eb->sent = ec_tx_done;
 
-		if (dev->hard_header) {
-			int res;
+		err = -EINVAL;
+		res = dev_hard_header(skb, dev, ntohs(proto), &addr, NULL, len);
+		if (res < 0)
+			goto out_free;
+		if (res > 0) {
 			struct ec_framehdr *fh;
-			err = -EINVAL;
-			res = dev->hard_header(skb, dev, ntohs(proto),
-					       &addr, NULL, len);
 			/* Poke in our control byte and
 			   port number.  Hack, hack.  */
 			fh = (struct ec_framehdr *)(skb->data);
@@ -368,8 +369,7 @@
 			if (sock->type != SOCK_DGRAM) {
 				skb_reset_tail_pointer(skb);
 				skb->len = 0;
-			} else if (res < 0)
-				goto out_free;
+			}
 		}
 
 		/* Copy the data. Returns -EFAULT on error */
diff --git a/net/ethernet/pe2.c b/net/ethernet/pe2.c
index 9d57b4f..d60e15d 100644
--- a/net/ethernet/pe2.c
+++ b/net/ethernet/pe2.c
@@ -12,9 +12,7 @@
 	struct net_device *dev = skb->dev;
 
 	skb->protocol = htons(ETH_P_IPX);
-	if (dev->hard_header)
-		dev->hard_header(skb, dev, ETH_P_IPX,
-				 dest_node, NULL, skb->len);
+	dev_hard_header(skb, dev, ETH_P_IPX, dest_node, NULL, skb->len);
 	return dev_queue_xmit(skb);
 }
 
diff --git a/net/ipv4/arp.c b/net/ipv4/arp.c
index 3a68300..5b24c65 100644
--- a/net/ipv4/arp.c
+++ b/net/ipv4/arp.c
@@ -591,8 +591,7 @@
 	/*
 	 *	Fill the device header for the ARP frame
 	 */
-	if (dev->hard_header &&
-	    dev->hard_header(skb,dev,ptype,dest_hw,src_hw,skb->len) < 0)
+	if (dev_hard_header(skb, dev, ptype, dest_hw, src_hw, skb->len) < 0)
 		goto out;
 
 	/*
diff --git a/net/ipv4/ipconfig.c b/net/ipv4/ipconfig.c
index af5d5b3..c5c107a 100644
--- a/net/ipv4/ipconfig.c
+++ b/net/ipv4/ipconfig.c
@@ -757,8 +757,8 @@
 	/* Chain packet down the line... */
 	skb->dev = dev;
 	skb->protocol = htons(ETH_P_IP);
-	if ((dev->hard_header &&
-	     dev->hard_header(skb, dev, ntohs(skb->protocol), dev->broadcast, dev->dev_addr, skb->len) < 0) ||
+	if (dev_hard_header(skb, dev, ntohs(skb->protocol),
+			    dev->broadcast, dev->dev_addr, skb->len) < 0 ||
 	    dev_queue_xmit(skb) < 0)
 		printk("E");
 }
diff --git a/net/ipv6/mcast.c b/net/ipv6/mcast.c
index 86d908b..8668ab3 100644
--- a/net/ipv6/mcast.c
+++ b/net/ipv6/mcast.c
@@ -1438,17 +1438,12 @@
 static inline int mld_dev_queue_xmit2(struct sk_buff *skb)
 {
 	struct net_device *dev = skb->dev;
+	unsigned char ha[MAX_ADDR_LEN];
 
-	if (dev->hard_header) {
-		unsigned char ha[MAX_ADDR_LEN];
-		int err;
-
-		ndisc_mc_map(&ipv6_hdr(skb)->daddr, ha, dev, 1);
-		err = dev->hard_header(skb, dev, ETH_P_IPV6, ha, NULL, skb->len);
-		if (err < 0) {
-			kfree_skb(skb);
-			return err;
-		}
+	ndisc_mc_map(&ipv6_hdr(skb)->daddr, ha, dev, 1);
+	if (dev_hard_header(skb, dev, ETH_P_IPV6, ha, NULL, skb->len) < 0) {
+		kfree_skb(skb);
+		return -EINVAL;
 	}
 	return dev_queue_xmit(skb);
 }
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 745e2cb..c5244b3 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -765,16 +765,10 @@
 	skb_reserve(skb, LL_RESERVED_SPACE(dev));
 	skb_reset_network_header(skb);
 
-	if (dev->hard_header) {
-		int res;
-		err = -EINVAL;
-		res = dev->hard_header(skb, dev, ntohs(proto), addr, NULL, len);
-		if (sock->type != SOCK_DGRAM) {
-			skb_reset_tail_pointer(skb);
-			skb->len = 0;
-		} else if (res < 0)
-			goto out_free;
-	}
+	err = -EINVAL;
+	if (sock->type == SOCK_DGRAM &&
+	    dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len) < 0)
+		goto out_free;
 
 	/* Returns -EFAULT on error */
 	err = memcpy_fromiovec(skb_put(skb,len), msg->msg_iov, len);
diff --git a/net/sched/sch_teql.c b/net/sched/sch_teql.c
index 146f453..d13970f 100644
--- a/net/sched/sch_teql.c
+++ b/net/sched/sch_teql.c
@@ -232,9 +232,12 @@
 	}
 	if (neigh_event_send(n, skb_res) == 0) {
 		int err;
+
 		read_lock(&n->lock);
-		err = dev->hard_header(skb, dev, ntohs(skb->protocol), n->ha, NULL, skb->len);
+		err = dev_hard_header(skb, dev, ntohs(skb->protocol),
+				      n->ha, NULL, skb->len);
 		read_unlock(&n->lock);
+
 		if (err < 0) {
 			neigh_release(n);
 			return -EINVAL;
diff --git a/net/tipc/eth_media.c b/net/tipc/eth_media.c
index 1a99e29..3bbef2a 100644
--- a/net/tipc/eth_media.c
+++ b/net/tipc/eth_media.c
@@ -77,7 +77,7 @@
 		skb_reset_network_header(clone);
 		dev = ((struct eth_bearer *)(tb_ptr->usr_handle))->dev;
 		clone->dev = dev;
-		dev->hard_header(clone, dev, ETH_P_TIPC,
+		dev_hard_header(clone, dev, ETH_P_TIPC,
 				 &dest->dev_addr.eth_addr,
 				 dev->dev_addr, clone->len);
 		dev_queue_xmit(clone);