[NET]: Add support for getting the permanent hardware address.

This patch adds a new field to net device to hold the permanent
hardware address, and adds a new generic ethtool_op function to
get that address.
Signed-off-by: Jon Wetzel <jon_wetzel@dell.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/ethtool.h

@@ -250,6 +250,12 @@ struct ethtool_stats {
 	u64	data[0];
 };
 
+struct ethtool_perm_addr {
+	u32	cmd;		/* ETHTOOL_GPERMADDR */
+	u32	size;
+	u8	data[0];
+};
+
 struct net_device;
 
 /* Some generic methods drivers may use in their ethtool_ops */
@@ -261,6 +267,8 @@ u32 ethtool_op_get_sg(struct net_device *dev);
 int ethtool_op_set_sg(struct net_device *dev, u32 data);
 u32 ethtool_op_get_tso(struct net_device *dev);
 int ethtool_op_set_tso(struct net_device *dev, u32 data);
+int ethtool_op_get_perm_addr(struct net_device *dev, 
+			     struct ethtool_perm_addr *addr, u8 *data);
 
 /**
  * &ethtool_ops - Alter and report network device settings
@@ -294,6 +302,7 @@ int ethtool_op_set_tso(struct net_device *dev, u32 data);
  * get_strings: Return a set of strings that describe the requested objects 
  * phys_id: Identify the device
  * get_stats: Return statistics about the device
+ * get_perm_addr: Gets the permanent hardware address
  * 
  * Description:
  *
@@ -352,6 +361,7 @@ struct ethtool_ops {
 	int	(*phys_id)(struct net_device *, u32);
 	int	(*get_stats_count)(struct net_device *);
 	void	(*get_ethtool_stats)(struct net_device *, struct ethtool_stats *, u64 *);
+	int	(*get_perm_addr)(struct net_device *, struct ethtool_perm_addr *, u8 *);
 	int	(*begin)(struct net_device *);
 	void	(*complete)(struct net_device *);
 };
@@ -389,6 +399,7 @@ struct ethtool_ops {
 #define ETHTOOL_GSTATS		0x0000001d /* get NIC-specific statistics */
 #define ETHTOOL_GTSO		0x0000001e /* Get TSO enable (ethtool_value) */
 #define ETHTOOL_STSO		0x0000001f /* Set TSO enable (ethtool_value) */
+#define ETHTOOL_GPERMADDR	0x00000020 /* Get permanent hardware address */
 
 /* compatibility with older code */
 #define SPARC_ETH_GSET		ETHTOOL_GSET

include/linux/netdevice.h

@@ -337,6 +337,7 @@ struct net_device
 	/* Interface address info. */
 	unsigned char		broadcast[MAX_ADDR_LEN];	/* hw bcast add	*/
 	unsigned char		dev_addr[MAX_ADDR_LEN];	/* hw address	*/
+	unsigned char		perm_addr[MAX_ADDR_LEN]; /* permanent hw address */
 	unsigned char		addr_len;	/* hardware address length	*/
 	unsigned short          dev_id;		/* for shared network cards */
 

net/core/ethtool.c

@@ -81,6 +81,18 @@ int ethtool_op_set_tso(struct net_device *dev, u32 data)
 	return 0;
 }
 
+int ethtool_op_get_perm_addr(struct net_device *dev, struct ethtool_perm_addr *addr, u8 *data)
+{
+	unsigned char len = dev->addr_len;
+	if ( addr->size < len )
+		return -ETOOSMALL;
+	
+	addr->size = len;
+	memcpy(data, dev->perm_addr, len);
+	return 0;
+}
+ 
+
 /* Handlers for each ethtool command */
 
 static int ethtool_get_settings(struct net_device *dev, void __user *useraddr)
@@ -683,6 +695,39 @@ static int ethtool_get_stats(struct net_device *dev, void __user *useraddr)
 	return ret;
 }
 
+static int ethtool_get_perm_addr(struct net_device *dev, void *useraddr)
+{
+	struct ethtool_perm_addr epaddr;
+	u8 *data;
+	int ret;
+
+	if (!dev->ethtool_ops->get_perm_addr)
+		return -EOPNOTSUPP;
+
+	if (copy_from_user(&epaddr,useraddr,sizeof(epaddr)))
+		return -EFAULT;
+
+	data = kmalloc(epaddr.size, GFP_USER);
+	if (!data)
+		return -ENOMEM;
+
+	ret = dev->ethtool_ops->get_perm_addr(dev,&epaddr,data);
+	if (ret)
+		return ret;
+
+	ret = -EFAULT;
+	if (copy_to_user(useraddr, &epaddr, sizeof(epaddr)))
+		goto out;
+	useraddr += sizeof(epaddr);
+	if (copy_to_user(useraddr, data, epaddr.size))
+		goto out;
+	ret = 0;
+
+ out:
+	kfree(data);
+	return ret;
+}
+
 /* The main entry point in this file.  Called from net/core/dev.c */
 
 int dev_ethtool(struct ifreq *ifr)
@@ -806,6 +851,9 @@ int dev_ethtool(struct ifreq *ifr)
 	case ETHTOOL_GSTATS:
 		rc = ethtool_get_stats(dev, useraddr);
 		break;
+	case ETHTOOL_GPERMADDR:
+		rc = ethtool_get_perm_addr(dev, useraddr);
+		break;
 	default:
 		rc =  -EOPNOTSUPP;
 	}
@@ -826,6 +874,7 @@ int dev_ethtool(struct ifreq *ifr)
 
 EXPORT_SYMBOL(dev_ethtool);
 EXPORT_SYMBOL(ethtool_op_get_link);
+EXPORT_SYMBOL_GPL(ethtool_op_get_perm_addr);
 EXPORT_SYMBOL(ethtool_op_get_sg);
 EXPORT_SYMBOL(ethtool_op_get_tso);
 EXPORT_SYMBOL(ethtool_op_get_tx_csum);