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Commit e024715f authored by Paolo 'Blaisorblade' Giarrusso's avatar Paolo 'Blaisorblade' Giarrusso Committed by Linus Torvalds
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uml: improve checking and diagnostics of ethernet MACs 



Improve checking and diagnostics for broadcast and multicast Ethernet MAC
addresses, and distinguish between those cases in output; also make sure the
device is assigned a MAC address valid only locally to avoid collisions.

Signed-off-by: default avatarPaolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: default avatarJeff Dike <jdike@linux.intel.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 85ee2ce8

arch/um/drivers/net_kern.c

+29 −9
Original line number Diff line number Diff line
@@ -283,7 +283,7 @@ void uml_net_user_timer_expire(unsigned long _conn) 
#endif

}



static void setup_etheraddr(char *str, unsigned char *addr)

static void setup_etheraddr(char *str, unsigned char *addr, char *name)

{

	char *end;

	int i;
@@ -302,15 +302,32 @@ static void setup_etheraddr(char *str, unsigned char *addr) 
		}

		str = end + 1;

	}

	if(addr[0] & 1){

	if (is_multicast_ether_addr(addr)) {

		printk(KERN_ERR

		       "Attempt to assign a broadcast ethernet address to a "

		       "Attempt to assign a multicast ethernet address to a "

		       "device disallowed\n");

		goto random;

	}

	if (!is_valid_ether_addr(addr)) {

		printk(KERN_ERR

		       "Attempt to assign an invalid ethernet address to a "

		       "device disallowed\n");

		goto random;

	}

	if (!is_local_ether_addr(addr)) {

		printk(KERN_WARNING

		       "Warning: attempt to assign a globally valid ethernet address to a "

		       "device\n");

		printk(KERN_WARNING "You should better enable the 2nd rightmost bit "

		      "in the first byte of the MAC, i.e. "

		      "%02x:%02x:%02x:%02x:%02x:%02x\n",

		      addr[0] | 0x02, addr[1], addr[2], addr[3], addr[4], addr[5]);

	}

	return;



random:

	printk(KERN_INFO

	       "Choosing a random ethernet address for device %s\n", name);

	random_ether_addr(addr);

}
@@ -331,6 +348,7 @@ static void eth_configure(int n, void *init, char *mac, 
	struct net_device *dev;

	struct uml_net_private *lp;

	int save, err, size;

	char name[sizeof(dev->name)];



	size = transport->private_size + sizeof(struct uml_net_private) +

		sizeof(((struct uml_net_private *) 0)->user);
@@ -344,7 +362,13 @@ static void eth_configure(int n, void *init, char *mac, 
	INIT_LIST_HEAD(&device->list);

	device->index = n;



	setup_etheraddr(mac, device->mac);

	/* If this name ends up conflicting with an existing registered

	 * netdevice, that is OK, register_netdev{,ice}() will notice this

	 * and fail.

	 */

	snprintf(name, sizeof(name), "eth%d", n);



	setup_etheraddr(mac, device->mac, name);



	printk(KERN_INFO "Netdevice %d ", n);

	printk("(%02x:%02x:%02x:%02x:%02x:%02x) ",
@@ -375,11 +399,7 @@ static void eth_configure(int n, void *init, char *mac, 
		goto out_free_netdev;

	SET_NETDEV_DEV(dev,&device->pdev.dev);



	/* If this name ends up conflicting with an existing registered

	 * netdevice, that is OK, register_netdev{,ice}() will notice this

	 * and fail.

	 */

	snprintf(dev->name, sizeof(dev->name), "eth%d", n);

	strcpy(dev->name, name);

	device->dev = dev;



	/*

include/linux/etherdevice.h

+12 −0
Original line number Diff line number Diff line
@@ -70,6 +70,18 @@ static inline int is_multicast_ether_addr(const u8 *addr) 
	return (0x01 & addr[0]);

}



/**

 * is_local_ether_addr - Determine if the Ethernet address is locally-assigned

 * one (IEEE 802).

 * @addr: Pointer to a six-byte array containing the Ethernet address

 *

 * Return true if the address is a local address.

 */

static inline int is_local_ether_addr(const u8 *addr)

{

	return (0x02 & addr[0]);

}



/**

 * is_broadcast_ether_addr - Determine if the Ethernet address is broadcast

 * @addr: Pointer to a six-byte array containing the Ethernet address