The NETDEV_CHANGEADDR notification is emitted after a device address
changes. Extending this message to allow vetoing is certainly possible,
but several other notification types have instead adopted a simple
two-stage approach: first a "pre" notification is sent to make sure all
interested parties are OK with a change that's about to be done. Then
the change is done, and afterwards a "post" notification is sent.
This dual approach is easier to use: when the change is vetoed, nothing
has changed yet, and it's therefore unnecessary to roll anything back.
Therefore adopt it for NETDEV_CHANGEADDR as well.
To that end, add NETDEV_PRE_CHANGEADDR and an info structure to go along
with it.
Signed-off-by: Petr Machata <pe...@mellanox.com>
Acked-by: Jiri Pirko <j...@mellanox.com>
Reviewed-by: Ido Schimmel <ido...@mellanox.com>
---
include/linux/netdevice.h | 8 +++++++-
net/core/dev.c | 1 +
2 files changed, 8 insertions(+), 1 deletion(-)
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index d89875ec21ac..1d5ad053ccf7 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -2450,7 +2450,8 @@ enum netdev_cmd {
NETDEV_REGISTER,
NETDEV_UNREGISTER,
NETDEV_CHANGEMTU, /* notify after mtu change happened */
- NETDEV_CHANGEADDR,
+ NETDEV_CHANGEADDR, /* notify after the address change */
+ NETDEV_PRE_CHANGEADDR, /* notify before the address change */
NETDEV_GOING_DOWN,
NETDEV_CHANGENAME,
NETDEV_FEAT_CHANGE,
@@ -2512,6 +2513,11 @@ struct netdev_notifier_changelowerstate_info {
void *lower_state_info; /* is lower dev state */
};
+struct netdev_notifier_pre_changeaddr_info {
+ struct netdev_notifier_info info; /* must be first */
+ const unsigned char *dev_addr;
+};
+
static inline void netdev_notifier_info_init(struct netdev_notifier_info *info,
struct net_device *dev)
{
diff --git a/net/core/dev.c b/net/core/dev.c
index 7250a3a73fa4..01497b7d1bdf 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1589,6 +1589,7 @@ const char *netdev_cmd_to_name(enum netdev_cmd cmd)
N(UDP_TUNNEL_DROP_INFO) N(CHANGE_TX_QUEUE_LEN)
N(CVLAN_FILTER_PUSH_INFO) N(CVLAN_FILTER_DROP_INFO)
N(SVLAN_FILTER_PUSH_INFO) N(SVLAN_FILTER_DROP_INFO)
+ N(PRE_CHANGEADDR)
}
#undef N
return "UNKNOWN_NETDEV_EVENT";
--
2.4.11
