Commit 90f942c5 authored by Vincent Mailhol's avatar Vincent Mailhol Committed by Marc Kleine-Budde
Browse files

can: dev: add generic function can_eth_ioctl_hwts() 

Tools based on libpcap (such as tcpdump) expect the SIOCSHWTSTAMP
ioctl call to be supported. This is also specified in the kernel doc
[1]. The purpose of this ioctl is to toggle the hardware timestamps.

Currently, CAN devices which support hardware timestamping have those
always activated. can_eth_ioctl_hwts() is a dumb function that will
always succeed when requested to set tx_type to HWTSTAMP_TX_ON or
rx_filter to HWTSTAMP_FILTER_ALL.

[1] Kernel doc: Timestamping, section 3.1 "Hardware Timestamping
Implementation: Device Drivers"
Link: https://docs.kernel.org/networking/timestamping.html#hardware-timestamping-implementation-device-drivers



Signed-off-by: default avatarVincent Mailhol <mailhol.vincent@wanadoo.fr>
Link: https://lore.kernel.org/all/20220727101641.198847-9-mailhol.vincent@wanadoo.fr


Signed-off-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
parent 7fb48d25

drivers/net/can/dev/dev.c

+29 −0
Original line number Diff line number Diff line
@@ -322,6 +322,35 @@ int can_change_mtu(struct net_device *dev, int new_mtu) 
}

EXPORT_SYMBOL_GPL(can_change_mtu);



/* generic implementation of netdev_ops::ndo_eth_ioctl for CAN devices

 * supporting hardware timestamps

 */

int can_eth_ioctl_hwts(struct net_device *netdev, struct ifreq *ifr, int cmd)

{

	struct hwtstamp_config hwts_cfg = { 0 };



	switch (cmd) {

	case SIOCSHWTSTAMP: /* set */

		if (copy_from_user(&hwts_cfg, ifr->ifr_data, sizeof(hwts_cfg)))

			return -EFAULT;

		if (hwts_cfg.tx_type == HWTSTAMP_TX_ON &&

		    hwts_cfg.rx_filter == HWTSTAMP_FILTER_ALL)

			return 0;

		return -ERANGE;



	case SIOCGHWTSTAMP: /* get */

		hwts_cfg.tx_type = HWTSTAMP_TX_ON;

		hwts_cfg.rx_filter = HWTSTAMP_FILTER_ALL;

		if (copy_to_user(ifr->ifr_data, &hwts_cfg, sizeof(hwts_cfg)))

			return -EFAULT;

		return 0;



	default:

		return -EOPNOTSUPP;

	}

}

EXPORT_SYMBOL(can_eth_ioctl_hwts);



/* generic implementation of ethtool_ops::get_ts_info for CAN devices

 * supporting hardware timestamps

 */

include/linux/can/dev.h

+1 −0
Original line number Diff line number Diff line
@@ -163,6 +163,7 @@ struct can_priv *safe_candev_priv(struct net_device *dev); 
int open_candev(struct net_device *dev);

void close_candev(struct net_device *dev);

int can_change_mtu(struct net_device *dev, int new_mtu);

int can_eth_ioctl_hwts(struct net_device *netdev, struct ifreq *ifr, int cmd);

int can_ethtool_op_get_ts_info_hwts(struct net_device *dev,

				    struct ethtool_ts_info *info);