On 11.07.2022 20:34:23, Oliver Hartkopp wrote:
> Enable the PF_CAN infrastructure to handle CAN XL frames. A new ethernet
> protocol type ETH_P_CANXL is defined to tag skbuffs containing the CAN XL
> frame data structure.
>
> As the length information is now a uint16 value for CAN XL a new helper
> function can_get_data_len() is introduced to retrieve the data length
> from all types of CAN frames.
>
> Signed-off-by: Oliver Hartkopp <socketcan@xxxxxxxxxxxx>
> ---
> include/linux/can/skb.h | 14 ++++++++++
> include/uapi/linux/if_ether.h | 1 +
> net/can/af_can.c | 49 +++++++++++++++++++++++++++++------
> 3 files changed, 56 insertions(+), 8 deletions(-)
>
> diff --git a/include/linux/can/skb.h b/include/linux/can/skb.h
> index 182749e858b3..d043bc4afd6d 100644
> --- a/include/linux/can/skb.h
> +++ b/include/linux/can/skb.h
> @@ -101,6 +101,20 @@ static inline bool can_is_canfd_skb(const struct sk_buff *skb)
> {
> /* the CAN specific type of skb is identified by its data length */
> return skb->len == CANFD_MTU;
> }
>
> +/* get data length inside of CAN frame for all frame types */
> +static inline unsigned int can_get_data_len(struct sk_buff *skb)
> +{
> + if(skb->len == CANXL_MTU) {
> + const struct canxl_frame *cfx = (struct canxl_frame *)skb->data;
> +
> + return cfx->len;
> + } else {
> + const struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
> +
> + return cfd->len;
> + }
> +}
> +
> #endif /* !_CAN_SKB_H */
> diff --git a/include/uapi/linux/if_ether.h b/include/uapi/linux/if_ether.h
> index d370165bc621..69e0457eb200 100644
> --- a/include/uapi/linux/if_ether.h
> +++ b/include/uapi/linux/if_ether.h
> @@ -136,10 +136,11 @@
> #define ETH_P_WAN_PPP 0x0007 /* Dummy type for WAN PPP frames*/
> #define ETH_P_PPP_MP 0x0008 /* Dummy type for PPP MP frames */
> #define ETH_P_LOCALTALK 0x0009 /* Localtalk pseudo type */
> #define ETH_P_CAN 0x000C /* CAN: Controller Area Network */
> #define ETH_P_CANFD 0x000D /* CANFD: CAN flexible data rate*/
> +#define ETH_P_CANXL 0x000E /* CANXL: eXtended frame Length */
> #define ETH_P_PPPTALK 0x0010 /* Dummy type for Atalk over PPP*/
> #define ETH_P_TR_802_2 0x0011 /* 802.2 frames */
> #define ETH_P_MOBITEX 0x0015 /* Mobitex (kaz@xxxxxxxx) */
> #define ETH_P_CONTROL 0x0016 /* Card specific control frames */
> #define ETH_P_IRDA 0x0017 /* Linux-IrDA */
This file doesn't change that often I suppose. Or does it make sense to
send this change mainline as soon as possible?
> diff --git a/net/can/af_can.c b/net/can/af_can.c
> index 1fb49d51b25d..2c9f48aa5f1f 100644
> --- a/net/can/af_can.c
> +++ b/net/can/af_can.c
> @@ -197,31 +197,32 @@ static int can_create(struct net *net, struct socket *sock, int protocol,
> * -EINVAL when the skb->data does not contain a valid CAN frame
> */
> int can_send(struct sk_buff *skb, int loop)
> {
> struct sk_buff *newskb = NULL;
> - struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
> + unsigned int len = can_get_data_len(skb);
> struct can_pkg_stats *pkg_stats = dev_net(skb->dev)->can.pkg_stats;
> int err = -EINVAL;
>
> if (skb->len == CAN_MTU) {
> skb->protocol = htons(ETH_P_CAN);
> - if (unlikely(cfd->len > CAN_MAX_DLEN))
> + if (unlikely(len > CAN_MAX_DLEN))
> goto inval_skb;
> } else if (skb->len == CANFD_MTU) {
> skb->protocol = htons(ETH_P_CANFD);
> - if (unlikely(cfd->len > CANFD_MAX_DLEN))
> + if (unlikely(len > CANFD_MAX_DLEN))
> + goto inval_skb;
> + } else if (skb->len == CANXL_MTU) {
> + skb->protocol = htons(ETH_P_CANXL);
> + if (unlikely(len > CANXL_MAX_DLEN || len == 0))
Do we need a helper for the > CANXL_MAX_DLEN || == 0 check?
> goto inval_skb;
> } else {
> goto inval_skb;
> }
>
> - /* Make sure the CAN frame can pass the selected CAN netdevice.
> - * As structs can_frame and canfd_frame are similar, we can provide
> - * CAN FD frames to legacy CAN drivers as long as the length is <= 8
> - */
> - if (unlikely(skb->len > skb->dev->mtu && cfd->len > CAN_MAX_DLEN)) {
> + /* Make sure the CAN frame can pass the selected CAN netdevice */
> + if (unlikely(skb->len > skb->dev->mtu)) {
> err = -EMSGSIZE;
> goto inval_skb;
> }
>
> if (unlikely(skb->dev->type != ARPHRD_CAN)) {
> @@ -725,10 +726,36 @@ static int canfd_rcv(struct sk_buff *skb, struct net_device *dev,
> free_skb:
> kfree_skb(skb);
> return NET_RX_DROP;
> }
>
> +static int canxl_rcv(struct sk_buff *skb, struct net_device *dev,
> + struct packet_type *pt, struct net_device *orig_dev)
> +{
> + struct canxl_frame *cfx = (struct canxl_frame *)skb->data;
> +
> + if (unlikely(dev->type != ARPHRD_CAN || skb->len != CANXL_MTU)) {
> + pr_warn_once("PF_CAN: dropped non conform CAN XL skbuff: dev type %d, len %d\n",
> + dev->type, skb->len);
> + goto free_skb;
> + }
> +
> + /* This check is made separately since cfx->len would be uninitialized if skb->len = 0. */
> + if (unlikely(cfx->len > CANXL_MAX_DLEN || cfx->len == 0)) {
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
regards,
Marc
--
Pengutronix e.K. | Marc Kleine-Budde |
Embedded Linux | https://www.pengutronix.de |
Vertretung West/Dortmund | Phone: +49-231-2826-924 |
Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
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