From fa0879e37b59e8e3f130a30a9e6fa515717c5bdd Mon Sep 17 00:00:00 2001
From: Stefan Hajnoczi <stefanha@gmail.com>
Date: Mon, 21 Jan 2013 01:17:22 +0000
Subject: [PATCH] net: split eth_mac_addr for better error handling
When we set mac address, software mac address in system and hardware mac
address all need to be updated. Current eth_mac_addr() doesn't allow
callers to implement error handling nicely.
This patch split eth_mac_addr() to prepare part and real commit part,
then we can prepare first, and try to change hardware address, then do
the real commit if hardware address is set successfully.
Signed-off-by: Stefan Hajnoczi <stefanha@gmail.com>
Signed-off-by: Amos Kong <akong@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
include/linux/etherdevice.h | 2 ++
net/ethernet/eth.c | 41 +++++++++++++++++++++++++++++++------
2 files changed, 37 insertions(+), 6 deletions(-)
diff --git a/include/linux/etherdevice.h b/include/linux/etherdevice.h
index 1a43e1b4f7ad..c623861964e4 100644
--- a/include/linux/etherdevice.h
+++ b/include/linux/etherdevice.h
@@ -40,6 +40,8 @@ extern int eth_header_cache(const struct neighbour *neigh, struct hh_cache *hh,
extern void eth_header_cache_update(struct hh_cache *hh,
const struct net_device *dev,
const unsigned char *haddr);
+extern int eth_prepare_mac_addr_change(struct net_device *dev, void *p);
+extern void eth_commit_mac_addr_change(struct net_device *dev, void *p);
extern int eth_mac_addr(struct net_device *dev, void *p);
extern int eth_change_mtu(struct net_device *dev, int new_mtu);
extern int eth_validate_addr(struct net_device *dev);
diff --git a/net/ethernet/eth.c b/net/ethernet/eth.c
index bc39c8c8f589..a36c85eab5b4 100644
--- a/net/ethernet/eth.c
+++ b/net/ethernet/eth.c
@@ -271,6 +271,36 @@ void eth_header_cache_update(struct hh_cache *hh,
}
EXPORT_SYMBOL(eth_header_cache_update);
+/**
+ * eth_prepare_mac_addr_change - prepare for mac change
+ * @dev: network device
+ * @p: socket address
+ */
+int eth_prepare_mac_addr_change(struct net_device *dev, void *p)
+{
+ struct sockaddr *addr = p;
+
+ if (!(dev->priv_flags & IFF_LIVE_ADDR_CHANGE) && netif_running(dev))
+ return -EBUSY;
+ if (!is_valid_ether_addr(addr->sa_data))
+ return -EADDRNOTAVAIL;
+ return 0;
+}
+EXPORT_SYMBOL(eth_prepare_mac_addr_change);
+
+/**
+ * eth_commit_mac_addr_change - commit mac change
+ * @dev: network device
+ * @p: socket address
+ */
+void eth_commit_mac_addr_change(struct net_device *dev, void *p)
+{
+ struct sockaddr *addr = p;
+
+ memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN);
+}
+EXPORT_SYMBOL(eth_commit_mac_addr_change);
+
/**
* eth_mac_addr - set new Ethernet hardware address
* @dev: network device
@@ -283,13 +313,12 @@ EXPORT_SYMBOL(eth_header_cache_update);
*/
int eth_mac_addr(struct net_device *dev, void *p)
{
- struct sockaddr *addr = p;
+ int ret;
- if (!(dev->priv_flags & IFF_LIVE_ADDR_CHANGE) && netif_running(dev))
- return -EBUSY;
- if (!is_valid_ether_addr(addr->sa_data))
- return -EADDRNOTAVAIL;
- memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN);
+ ret = eth_prepare_mac_addr_change(dev, p);
+ if (ret < 0)
+ return ret;
+ eth_commit_mac_addr_change(dev, p);
return 0;
}
EXPORT_SYMBOL(eth_mac_addr);