[NET]: Size hh_cache->hh_data more appropriately.

drivers/net/myri_sbus.c

@@ -766,10 +766,14 @@ static int myri_rebuild_header(struct sk_buff *skb)
 int myri_header_cache(struct neighbour *neigh, struct hh_cache *hh)
 {
 	unsigned short type = hh->hh_type;
-	unsigned char *pad = (unsigned char *) hh->hh_data;
-	struct ethhdr *eth = (struct ethhdr *) (pad + MYRI_PAD_LEN);
+	unsigned char *pad;
+	struct ethhdr *eth;
 	struct net_device *dev = neigh->dev;
 
+	pad = ((unsigned char *) hh->hh_data) +
+		HH_DATA_OFF(sizeof(*eth) + MYRI_PAD_LEN);
+	eth = (struct ethhdr *) (pad + MYRI_PAD_LEN);
+
 	if (type == __constant_htons(ETH_P_802_3))
 		return -1;
 
@@ -788,7 +792,8 @@ int myri_header_cache(struct neighbour *neigh, struct hh_cache *hh)
 /* Called by Address Resolution module to notify changes in address. */
 void myri_header_cache_update(struct hh_cache *hh, struct net_device *dev, unsigned char * haddr)
 {
-	memcpy(((u8*)hh->hh_data) + 2, haddr, dev->addr_len);
+	memcpy(((u8*)hh->hh_data) + HH_DATA_OFF(sizeof(struct ethhdr)),
+	       haddr, dev->addr_len);
 }
 
 static int myri_change_mtu(struct net_device *dev, int new_mtu)

drivers/net/plip.c

@@ -1078,7 +1078,10 @@ int plip_hard_header_cache(struct neighbour *neigh,
 	
 	if ((ret = nl->orig_hard_header_cache(neigh, hh)) == 0)
 	{
-		struct ethhdr *eth = (struct ethhdr*)(((u8*)hh->hh_data) + 2);
+		struct ethhdr *eth;
+
+		eth = (struct ethhdr*)(((u8*)hh->hh_data) +
+				       HH_DATA_OFF(sizeof(*eth)));
 		plip_rewrite_address (neigh->dev, eth);
 	}
 	

include/linux/netdevice.h

@@ -195,8 +195,14 @@ struct hh_cache
 	int		hh_len;		/* length of header */
 	int		(*hh_output)(struct sk_buff *skb);
 	rwlock_t	hh_lock;
+
 	/* cached hardware header; allow for machine alignment needs.        */
-	unsigned long	hh_data[16/sizeof(unsigned long)];
+#define HH_DATA_MOD	16
+#define HH_DATA_OFF(__len) \
+	(HH_DATA_MOD - ((__len) & (HH_DATA_MOD - 1)))
+#define HH_DATA_ALIGN(__len) \
+	(((__len)+(HH_DATA_MOD-1))&~(HH_DATA_MOD - 1))
+	unsigned long	hh_data[HH_DATA_ALIGN(LL_MAX_HEADER)];
 };
 
 /* These flag bits are private to the generic network queueing

net/ethernet/eth.c

@@ -216,9 +216,12 @@ int eth_header_parse(struct sk_buff *skb, unsigned char *haddr)
 int eth_header_cache(struct neighbour *neigh, struct hh_cache *hh)
 {
 	unsigned short type = hh->hh_type;
-	struct ethhdr *eth = (struct ethhdr*)(((u8*)hh->hh_data) + 2);
+	struct ethhdr *eth;
 	struct net_device *dev = neigh->dev;
 
+	eth = (struct ethhdr*)
+		(((u8*)hh->hh_data) + (HH_DATA_OFF(sizeof(*eth))));
+
 	if (type == __constant_htons(ETH_P_802_3))
 		return -1;
 
@@ -235,5 +238,6 @@ int eth_header_cache(struct neighbour *neigh, struct hh_cache *hh)
 
 void eth_header_cache_update(struct hh_cache *hh, struct net_device *dev, unsigned char * haddr)
 {
-	memcpy(((u8*)hh->hh_data) + 2, haddr, dev->addr_len);
+	memcpy(((u8*)hh->hh_data) + HH_DATA_OFF(sizeof(struct ethhdr)),
+	       haddr, dev->addr_len);
 }

net/ipv4/ip_output.c

@@ -193,8 +193,11 @@ static inline int ip_finish_output2(struct sk_buff *skb)
 #endif /*CONFIG_NETFILTER_DEBUG*/
 
 	if (hh) {
+		int hh_alen;
+
 		read_lock_bh(&hh->hh_lock);
-  		memcpy(skb->data - 16, hh->hh_data, 16);
+		hh_alen = HH_DATA_ALIGN(hh->hh_len);
+  		memcpy(skb->data - hh_alen, hh->hh_data, hh_alen);
 		read_unlock_bh(&hh->hh_lock);
 	        skb_push(skb, hh->hh_len);
 		return hh->hh_output(skb);

net/ipv4/netfilter/ipt_MIRROR.c

@@ -90,8 +90,11 @@ static void ip_direct_send(struct sk_buff *skb)
 	struct hh_cache *hh = dst->hh;
 
 	if (hh) {
+		int hh_alen;
+
 		read_lock_bh(&hh->hh_lock);
-  		memcpy(skb->data - 16, hh->hh_data, 16);
+		hh_alen = HH_DATA_ALIGN(hh->hh_len);
+  		memcpy(skb->data - hh_alen, hh->hh_data, hh_alen);
 		read_unlock_bh(&hh->hh_lock);
 	        skb_push(skb, hh->hh_len);
 		hh->hh_output(skb);

net/ipv6/ip6_output.c

@@ -76,8 +76,11 @@ static inline int ip6_output_finish(struct sk_buff *skb)
 	struct hh_cache *hh = dst->hh;
 
 	if (hh) {
+		int hh_alen;
+
 		read_lock_bh(&hh->hh_lock);
-		memcpy(skb->data - 16, hh->hh_data, 16);
+		hh_alen = HH_DATA_ALIGN(hh->hh_len);
+		memcpy(skb->data - hh_alen, hh->hh_data, hh_alen);
 		read_unlock_bh(&hh->hh_lock);
 	        skb_push(skb, hh->hh_len);
 		return hh->hh_output(skb);