From 061834624c87282c6d9d8c5395aaff4380e5e1fc Mon Sep 17 00:00:00 2001 From: Oliver Hartkopp Date: Mon, 12 Sep 2022 19:07:21 +0200 Subject: [PATCH] can: set CANFD_FDF flag in all CAN FD frame structures To simplify the testing in user space all struct canfd_frame's provided by the CAN subsystem of the Linux kernel now have the CANFD_FDF flag set in canfd_frame::flags. NB: Handcrafted ETH_P_CANFD frames introduced via PF_PACKET socket might not set this bit correctly. During the check for sufficient headroom in PF_PACKET sk_buffs the uninitialized CAN sk_buff data structures are filled. In the case of a CAN FD frame the CANFD_FDF flag is set accordingly. As the CAN frame content is already zero initialized in alloc_canfd_skb() the obsolete initialization of cf->flags in the CTU CAN FD driver has been removed as it would overwrite the already set CANFD_FDF flag. Acked-by: Vincent Mailhol Signed-off-by: Oliver Hartkopp Link: https://lore.kernel.org/all/20220912170725.120748-4-socketcan@hartkopp.net Signed-off-by: Marc Kleine-Budde --- drivers/net/can/ctucanfd/ctucanfd_base.c | 1 - drivers/net/can/dev/skb.c | 11 +++++++++++ include/uapi/linux/can.h | 4 ++-- net/can/af_can.c | 5 +++++ 4 files changed, 18 insertions(+), 3 deletions(-) diff --git a/drivers/net/can/ctucanfd/ctucanfd_base.c b/drivers/net/can/ctucanfd/ctucanfd_base.c index 3c18d02..c402671 100644 --- a/drivers/net/can/ctucanfd/ctucanfd_base.c +++ b/drivers/net/can/ctucanfd/ctucanfd_base.c @@ -657,7 +657,6 @@ static void ctucan_read_rx_frame(struct ctucan_priv *priv, struct canfd_frame *c cf->can_id = (idw >> 18) & CAN_SFF_MASK; /* BRS, ESI, RTR Flags */ - cf->flags = 0; if (FIELD_GET(REG_FRAME_FORMAT_W_FDF, ffw)) { if (FIELD_GET(REG_FRAME_FORMAT_W_BRS, ffw)) cf->flags |= CANFD_BRS; diff --git a/drivers/net/can/dev/skb.c b/drivers/net/can/dev/skb.c index b896e1c..adb413b 100644 --- a/drivers/net/can/dev/skb.c +++ b/drivers/net/can/dev/skb.c @@ -244,6 +244,9 @@ struct sk_buff *alloc_canfd_skb(struct net_device *dev, *cfd = skb_put_zero(skb, sizeof(struct canfd_frame)); + /* set CAN FD flag by default */ + (*cfd)->flags = CANFD_FDF; + return skb; } EXPORT_SYMBOL_GPL(alloc_canfd_skb); @@ -287,6 +290,14 @@ static bool can_skb_headroom_valid(struct net_device *dev, struct sk_buff *skb) skb_reset_mac_header(skb); skb_reset_network_header(skb); skb_reset_transport_header(skb); + + /* set CANFD_FDF flag for CAN FD frames */ + if (can_is_canfd_skb(skb)) { + struct canfd_frame *cfd; + + cfd = (struct canfd_frame *)skb->data; + cfd->flags |= CANFD_FDF; + } } return true; diff --git a/include/uapi/linux/can.h b/include/uapi/linux/can.h index 90801ad..7b23eee 100644 --- a/include/uapi/linux/can.h +++ b/include/uapi/linux/can.h @@ -141,8 +141,8 @@ struct can_frame { * When this is done the former differentiation via CAN_MTU / CANFD_MTU gets * lost. CANFD_FDF allows programmers to mark CAN FD frames in the case of * using struct canfd_frame for mixed CAN / CAN FD content (dual use). - * N.B. the Kernel APIs do NOT provide mixed CAN / CAN FD content inside of - * struct canfd_frame therefore the CANFD_FDF flag is disregarded by Linux. + * Since the introduction of CAN XL the CANFD_FDF flag is set in all CAN FD + * frame structures provided by the CAN subsystem of the Linux kernel. */ #define CANFD_BRS 0x01 /* bit rate switch (second bitrate for payload data) */ #define CANFD_ESI 0x02 /* error state indicator of the transmitting node */ diff --git a/net/can/af_can.c b/net/can/af_can.c index afa6c21..072a6a5 100644 --- a/net/can/af_can.c +++ b/net/can/af_can.c @@ -205,7 +205,12 @@ int can_send(struct sk_buff *skb, int loop) if (can_is_can_skb(skb)) { skb->protocol = htons(ETH_P_CAN); } else if (can_is_canfd_skb(skb)) { + struct canfd_frame *cfd = (struct canfd_frame *)skb->data; + skb->protocol = htons(ETH_P_CANFD); + + /* set CAN FD flag for CAN FD frames by default */ + cfd->flags |= CANFD_FDF; } else { goto inval_skb; } -- 2.7.4