Subject: Re: [RFC net-next] bonding: notify when bonding device address changes

From: Jay Vosburgh <[email-masked]>
Date: Fri, 15 Apr 2011 12:28:24 -0700

Stephen Hemminger <[email-masked]> wrote:

>When a device changes its hardware address, it needs to call the network
>device notifiers to inform protocols.
>
>Compile tested only.

	We'll need to test this, I think.  If I'm not mistaken, I
believe that inetdev_event will issue gratuitous ARPs when it gets the
NETDEV_CHANGEADDR, and we need to make sure those are correct for all
cases.

>Signed-off-by: Stephen Hemminger <[email-masked]>
>
>--- a/drivers/net/bonding/bond_main.c	2011-04-15 11:21:02.142866195 -0700
>+++ b/drivers/net/bonding/bond_main.c	2011-04-15 11:28:06.491408825 -0700
>@@ -967,9 +967,11 @@ static void bond_do_fail_over_mac(struct
>
> 	switch (bond->params.fail_over_mac) {
> 	case BOND_FOM_ACTIVE:
>-		if (new_active)
>+		if (new_active) {
> 			memcpy(bond->dev->dev_addr,  new_active->dev->dev_addr,
> 			       new_active->dev->addr_len);
>+			call_netdevice_notifiers(NETDEV_CHANGEADDR, bond->dev);
>+		}
> 		break;
> 	case BOND_FOM_FOLLOW:
> 		/*
>@@ -1386,6 +1388,7 @@ static int bond_sethwaddr(struct net_dev
> 	pr_debug("slave_dev=%p\n", slave_dev);
> 	pr_debug("slave_dev->addr_len=%d\n", slave_dev->addr_len);
> 	memcpy(bond_dev->dev_addr, slave_dev->dev_addr, slave_dev->addr_len);
>+	call_netdevice_notifiers(NETDEV_CHANGEADDR, bond_dev);
> 	return 0;
> }
>
>@@ -1644,10 +1647,11 @@ int bond_enslave(struct net_device *bond
>
> 	/* If this is the first slave, then we need to set the master's hardware
> 	 * address to be the same as the slave's. */
>-	if (is_zero_ether_addr(bond->dev->dev_addr))
>+	if (is_zero_ether_addr(bond->dev->dev_addr)) {
> 		memcpy(bond->dev->dev_addr, slave_dev->dev_addr,
> 		       slave_dev->addr_len);
>-
>+		call_netdevice_notifiers(NETDEV_CHANGEADDR, bond->dev);
>+	}
>
> 	new_slave = kzalloc(sizeof(struct slave), GFP_KERNEL);
> 	if (!new_slave) {
>@@ -2067,6 +2071,7 @@ int bond_release(struct net_device *bond
> 		 * to the mac address of the first slave
> 		 */
> 		memset(bond_dev->dev_addr, 0, bond_dev->addr_len);
>+		call_netdevice_notifiers(NETDEV_CHANGEADDR, bond_dev);

	This one in particular I'm not sure about; should the system
send a gratuitous ARP for a MAC address of all zeroes?

> 		if (!bond->vlgrp) {
> 			bond_dev->features |= NETIF_F_VLAN_CHALLENGED;
>@@ -2252,6 +2257,7 @@ static int bond_release_all(struct net_d
> 	 * first slave
> 	 */
> 	memset(bond_dev->dev_addr, 0, bond_dev->addr_len);
>+	call_netdevice_notifiers(NETDEV_CHANGEADDR, bond_dev);

	Same comment for this one.

> 	if (!bond->vlgrp) {
> 		bond_dev->features |= NETIF_F_VLAN_CHALLENGED;

	-J

---
	-Jay Vosburgh, IBM Linux Technology Center, [email-masked]