llc: use dev_hard_header

Using dev_hard_header allows us to use LLC with VLANs and potentially
other Ethernet/TokernRing specific encapsulations. It also removes code
duplication between LLC and Ethernet/TokenRing core code.

Signed-off-by: Octavian Purdila <opurdila@ixiacom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/llc/llc_output.c b/net/llc/llc_output.c
index 754f4fe..b38a107 100644
--- a/net/llc/llc_output.c
+++ b/net/llc/llc_output.c
@@ -33,48 +33,19 @@
 int llc_mac_hdr_init(struct sk_buff *skb,
 		     const unsigned char *sa, const unsigned char *da)
 {
-	int rc = 0;
+	int rc = -EINVAL;
 
 	switch (skb->dev->type) {
-#ifdef CONFIG_TR
-	case ARPHRD_IEEE802_TR: {
-		struct net_device *dev = skb->dev;
-		struct trh_hdr *trh;
-
-		skb_push(skb, sizeof(*trh));
-		skb_reset_mac_header(skb);
-		trh = tr_hdr(skb);
-		trh->ac = AC;
-		trh->fc = LLC_FRAME;
-		if (sa)
-			memcpy(trh->saddr, sa, dev->addr_len);
-		else
-			memset(trh->saddr, 0, dev->addr_len);
-		if (da) {
-			memcpy(trh->daddr, da, dev->addr_len);
-			tr_source_route(skb, trh, dev);
-			skb_reset_mac_header(skb);
-		}
-		break;
-	}
-#endif
+	case ARPHRD_IEEE802_TR:
 	case ARPHRD_ETHER:
-	case ARPHRD_LOOPBACK: {
-		unsigned short len = skb->len;
-		struct ethhdr *eth;
-
-		skb_push(skb, sizeof(*eth));
-		skb_reset_mac_header(skb);
-		eth = eth_hdr(skb);
-		eth->h_proto = htons(len);
-		memcpy(eth->h_dest, da, ETH_ALEN);
-		memcpy(eth->h_source, sa, ETH_ALEN);
+	case ARPHRD_LOOPBACK:
+		rc = dev_hard_header(skb, skb->dev, ETH_P_802_2, da, sa,
+				     skb->len);
+		if (rc > 0)
+			rc = 0;
 		break;
-	}
 	default:
-		printk(KERN_WARNING "device type not supported: %d\n",
-		       skb->dev->type);
-		rc = -EINVAL;
+		WARN(1, "device type not supported: %d\n", skb->dev->type);
 	}
 	return rc;
 }