From: Vincent Mailhol Whenever can_validate_bittiming() is called, it is always preceded by some boilerplate code which was copy pasted all over the place. Move that repeated code directly inside can_validate_bittiming(). Finally, the mempcy() is not needed: the nla attributes are four bytes aligned which is just enough for struct can_bittiming. Add a static_assert() to document that the alignment is correct and just use the pointer returned by nla_data() as-is. Signed-off-by: Vincent Mailhol Link: https://patch.msgid.link/20250923-canxl-netlink-prep-v4-4-e720d28f66fe@kernel.org Signed-off-by: Marc Kleine-Budde --- drivers/net/can/dev/netlink.c | 36 +++++++++++++++++------------------ 1 file changed, 17 insertions(+), 19 deletions(-) diff --git a/drivers/net/can/dev/netlink.c b/drivers/net/can/dev/netlink.c index 248f607e3864..13555253e789 100644 --- a/drivers/net/can/dev/netlink.c +++ b/drivers/net/can/dev/netlink.c @@ -36,13 +36,21 @@ static const struct nla_policy can_tdc_policy[IFLA_CAN_TDC_MAX + 1] = { [IFLA_CAN_TDC_TDCF] = { .type = NLA_U32 }, }; -static int can_validate_bittiming(const struct can_bittiming *bt, - struct netlink_ext_ack *extack) +static int can_validate_bittiming(struct nlattr *data[], + struct netlink_ext_ack *extack, + int ifla_can_bittiming) { + struct can_bittiming *bt; + + if (!data[ifla_can_bittiming]) + return 0; + + static_assert(__alignof__(*bt) <= NLA_ALIGNTO); + bt = nla_data(data[ifla_can_bittiming]); + /* sample point is in one-tenth of a percent */ if (bt->sample_point >= 1000) { NL_SET_ERR_MSG(extack, "sample point must be between 0 and 100%"); - return -EINVAL; } @@ -105,14 +113,9 @@ static int can_validate(struct nlattr *tb[], struct nlattr *data[], } } - if (data[IFLA_CAN_BITTIMING]) { - struct can_bittiming bt; - - memcpy(&bt, nla_data(data[IFLA_CAN_BITTIMING]), sizeof(bt)); - err = can_validate_bittiming(&bt, extack); - if (err) - return err; - } + err = can_validate_bittiming(data, extack, IFLA_CAN_BITTIMING); + if (err) + return err; if (is_can_fd) { if (!data[IFLA_CAN_BITTIMING] || !data[IFLA_CAN_DATA_BITTIMING]) @@ -124,14 +127,9 @@ static int can_validate(struct nlattr *tb[], struct nlattr *data[], return -EOPNOTSUPP; } - if (data[IFLA_CAN_DATA_BITTIMING]) { - struct can_bittiming bt; - - memcpy(&bt, nla_data(data[IFLA_CAN_DATA_BITTIMING]), sizeof(bt)); - err = can_validate_bittiming(&bt, extack); - if (err) - return err; - } + err = can_validate_bittiming(data, extack, IFLA_CAN_DATA_BITTIMING); + if (err) + return err; return 0; } -- 2.51.0