can: fix WARN_ON dump in net/core/rtnetlink.c:rtmsg_ifinfo()
On older kernels, e.g. 2.6.27, a WARN_ON dump in rtmsg_ifinfo()
is thrown when the CAN device is registered due to insufficient
skb space, as reported by various users. This patch adds the
rtnl_link_ops "get_size" to fix the problem. I think this patch
is required for more recent kernels as well, even if no WARN_ON
dumps are triggered. Maybe we also need "get_xstats_size" for
the CAN xstats.
Signed-off-by: Wolfgang Grandegger <wg@grandegger.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/can/dev.c b/drivers/net/can/dev.c
index f0b9a1e..564e31c 100644
--- a/drivers/net/can/dev.c
+++ b/drivers/net/can/dev.c
@@ -589,6 +589,22 @@
return 0;
}
+static size_t can_get_size(const struct net_device *dev)
+{
+ struct can_priv *priv = netdev_priv(dev);
+ size_t size;
+
+ size = nla_total_size(sizeof(u32)); /* IFLA_CAN_STATE */
+ size += sizeof(struct can_ctrlmode); /* IFLA_CAN_CTRLMODE */
+ size += nla_total_size(sizeof(u32)); /* IFLA_CAN_RESTART_MS */
+ size += sizeof(struct can_bittiming); /* IFLA_CAN_BITTIMING */
+ size += sizeof(struct can_clock); /* IFLA_CAN_CLOCK */
+ if (priv->bittiming_const) /* IFLA_CAN_BITTIMING_CONST */
+ size += sizeof(struct can_bittiming_const);
+
+ return size;
+}
+
static int can_fill_info(struct sk_buff *skb, const struct net_device *dev)
{
struct can_priv *priv = netdev_priv(dev);
@@ -639,6 +655,7 @@
.setup = can_setup,
.newlink = can_newlink,
.changelink = can_changelink,
+ .get_size = can_get_size,
.fill_info = can_fill_info,
.fill_xstats = can_fill_xstats,
};