@@ -21,6 +21,7 @@ static const struct nla_policy can_policy[IFLA_CAN_MAX + 1] = {
[IFLA_CAN_DATA_BITTIMING_CONST] = { .len = sizeof(struct can_bittiming_const) },
[IFLA_CAN_TERMINATION] = { .type = NLA_U16 },
[IFLA_CAN_TDC] = { .type = NLA_NESTED },
+ [IFLA_CAN_CTRLMODE_EXT] = { .type = NLA_NESTED },
};
static const struct nla_policy can_tdc_policy[IFLA_CAN_TDC_MAX + 1] = {
@@ -383,6 +384,12 @@ static size_t can_tdc_get_size(const struct net_device *dev)
return size;
}
+static size_t can_ctrlmode_ext_get_size(void)
+{
+ return nla_total_size(0) + /* nest IFLA_CAN_CTRLMODE_EXT */
+ nla_total_size(sizeof(u32)); /* IFLA_CAN_CTRLMODE_SUPPORTED */
+}
+
static size_t can_get_size(const struct net_device *dev)
{
struct can_priv *priv = netdev_priv(dev);
@@ -415,6 +422,7 @@ static size_t can_get_size(const struct net_device *dev)
priv->data_bitrate_const_cnt);
size += sizeof(priv->bitrate_max); /* IFLA_CAN_BITRATE_MAX */
size += can_tdc_get_size(dev); /* IFLA_CAN_TDC */
+ size += can_ctrlmode_ext_get_size(); /* IFLA_CAN_CTRLMODE_EXT */
return size;
}
@@ -472,6 +480,25 @@ static int can_tdc_fill_info(struct sk_buff *skb, const struct net_device *dev)
return -EMSGSIZE;
}
+static int can_ctrlmode_ext_fill_info(struct sk_buff *skb,
+ const struct can_priv *priv)
+{
+ struct nlattr *nest;
+
+ nest = nla_nest_start(skb, IFLA_CAN_CTRLMODE_EXT);
+ if (!nest)
+ return -EMSGSIZE;
+
+ if (nla_put_u32(skb, IFLA_CAN_CTRLMODE_SUPPORTED,
+ priv->ctrlmode_supported)) {
+ nla_nest_cancel(skb, nest);
+ return -EMSGSIZE;
+ }
+
+ nla_nest_end(skb, nest);
+ return 0;
+}
+
static int can_fill_info(struct sk_buff *skb, const struct net_device *dev)
{
struct can_priv *priv = netdev_priv(dev);
@@ -531,7 +558,9 @@ static int can_fill_info(struct sk_buff *skb, const struct net_device *dev)
sizeof(priv->bitrate_max),
&priv->bitrate_max)) ||
- (can_tdc_fill_info(skb, dev))
+ can_tdc_fill_info(skb, dev) ||
+
+ can_ctrlmode_ext_fill_info(skb, priv)
)
return -EMSGSIZE;
@@ -137,6 +137,7 @@ enum {
IFLA_CAN_DATA_BITRATE_CONST,
IFLA_CAN_BITRATE_MAX,
IFLA_CAN_TDC,
+ IFLA_CAN_CTRLMODE_EXT,
/* add new constants above here */
__IFLA_CAN_MAX,
@@ -166,6 +167,18 @@ enum {
IFLA_CAN_TDC_MAX = __IFLA_CAN_TDC - 1
};
+/*
+ * IFLA_CAN_CTRLMODE_EXT nest: controller mode extended parameters
+ */
+enum {
+ IFLA_CAN_CTRLMODE_UNSPEC,
+ IFLA_CAN_CTRLMODE_SUPPORTED, /* u32 */
+
+ /* add new constants above here */
+ __IFLA_CAN_CTRLMODE,
+ IFLA_CAN_CTRLMODE_MAX = __IFLA_CAN_CTRLMODE - 1
+};
+
/* u16 termination range: 1..65535 Ohms */
#define CAN_TERMINATION_DISABLED 0
Currently, the CAN netlink interface provides no easy ways to check the capabilities of a given controller. The only method from the command line is to try each CAN_CTRLMODE_* individually to check whether the netlink interface returns an -EOPNOTSUPP error or not (alternatively, one may find it easier to directly check the source code of the driver instead...) This patch introduces a method for the user to check both the supported and the static capabilities. The proposed method introduces a new IFLA nest: IFLA_CAN_CTRLMODE_EXT which extends the current IFLA_CAN_CTRLMODE. This is done to guaranty a full forward and backward compatibility between the kernel and the user land applications. The IFLA_CAN_CTRLMODE_EXT nest contains one single entry: IFLA_CAN_CTRLMODE_SUPPORTED. Because this entry is only used in one direction: kernel to userland, no new struct nla_policy are introduced. Below table explains how IFLA_CAN_CTRLMODE_SUPPORTED (hereafter: "supported") and can_ctrlmode::flags (hereafter: "flags") allow us to identify both the supported and the static capabilities, when masked with any of the CAN_CTRLMODE_* bit flags: supported & flags & Controller capabilities CAN_CTRLMODE_* CAN_CTRLMODE_* ----------------------------------------------------------------------- false false Feature not supported (always disabled) false true Static feature (always enabled) true false Feature supported but disabled true true Feature supported and enabled Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> --- drivers/net/can/dev/netlink.c | 31 ++++++++++++++++++++++++++++++- include/uapi/linux/can/netlink.h | 13 +++++++++++++ 2 files changed, 43 insertions(+), 1 deletion(-)