Re: [PATCH v1 2/6] hw/net/can: sja1000 ignore CAN FD frames

[Vikram Garhwal]

On Tue, Jul 14, 2020 at 02:20:15PM +0200, pisa@cmp.felk.cvut.cz wrote:
> From: Jan Charvat <charvj10@fel.cvut.cz>
>
> Signed-off-by: Jan Charvat <charvj10@fel.cvut.cz>
> Signed-off-by: Pavel Pisa <pisa@cmp.felk.cvut.cz>

Reviewed-by: Vikram Garhwal <fnu.vikram@xilinx.com>

> ---
>  hw/net/can/can_sja1000.c | 29 +++++++++++++++++++++++------
>  1 file changed, 23 insertions(+), 6 deletions(-)
>
> diff --git a/hw/net/can/can_sja1000.c b/hw/net/can/can_sja1000.c
> index d83c550edc..382911560c 100644
> --- a/hw/net/can/can_sja1000.c
> +++ b/hw/net/can/can_sja1000.c
> @@ -323,11 +323,16 @@ static void buff2frame_bas(const uint8_t *buff, 
> qemu_can_frame *frame)
>  static int frame2buff_pel(const qemu_can_frame *frame, uint8_t *buff)
>  {
>      int i;
> +    int dlen = frame->can_dlc;
>
>      if (frame->can_id & QEMU_CAN_ERR_FLAG) { /* error frame, NOT support 
> now. */
>          return -1;
>      }
>
> +    if (dlen > 8) {
> +        return -1;
> +    }
> +
>      buff[0] = 0x0f & frame->can_dlc; /* DLC */
>      if (frame->can_id & QEMU_CAN_RTR_FLAG) { /* RTR */
>          buff[0] |= (1 << 6);
> @@ -338,18 +343,18 @@ static int frame2buff_pel(const qemu_can_frame *frame, 
> uint8_t *buff)
>          buff[2] = extract32(frame->can_id, 13, 8); /* ID.20~ID.13 */
>          buff[3] = extract32(frame->can_id, 5, 8);  /* ID.12~ID.05 */
>          buff[4] = extract32(frame->can_id, 0, 5) << 3; /* ID.04~ID.00,xxx */
> -        for (i = 0; i < frame->can_dlc; i++) {
> +        for (i = 0; i < dlen; i++) {
>              buff[5 + i] = frame->data[i];
>          }
> -        return frame->can_dlc + 5;
> +        return dlen + 5;
>      } else { /* SFF */
>          buff[1] = extract32(frame->can_id, 3, 8); /* ID.10~ID.03 */
>          buff[2] = extract32(frame->can_id, 0, 3) << 5; /* ID.02~ID.00,xxxxx 
> */
> -        for (i = 0; i < frame->can_dlc; i++) {
> +        for (i = 0; i < dlen; i++) {
>              buff[3 + i] = frame->data[i];
>          }
>
> -        return frame->can_dlc + 3;
> +        return dlen + 3;
>      }
>
>      return -1;
> @@ -358,6 +363,7 @@ static int frame2buff_pel(const qemu_can_frame *frame, 
> uint8_t *buff)
>  static int frame2buff_bas(const qemu_can_frame *frame, uint8_t *buff)
>  {
>      int i;
> +    int dlen = frame->can_dlc;
>
>       /*
>        * EFF, no support for BasicMode
> @@ -369,17 +375,21 @@ static int frame2buff_bas(const qemu_can_frame *frame, 
> uint8_t *buff)
>          return -1;
>      }
>
> +    if (dlen > 8) {
> +        return -1;
> +    }
> +
>      buff[0] = extract32(frame->can_id, 3, 8); /* ID.10~ID.03 */
>      buff[1] = extract32(frame->can_id, 0, 3) << 5; /* ID.02~ID.00,xxxxx */
>      if (frame->can_id & QEMU_CAN_RTR_FLAG) { /* RTR */
>          buff[1] |= (1 << 4);
>      }
>      buff[1] |= frame->can_dlc & 0x0f;
> -    for (i = 0; i < frame->can_dlc; i++) {
> +    for (i = 0; i < dlen; i++) {
>          buff[2 + i] = frame->data[i];
>      }
>
> -    return frame->can_dlc + 2;
> +    return dlen + 2;
>  }
>
>  static void can_sja_update_pel_irq(CanSJA1000State *s)
> @@ -764,6 +774,13 @@ ssize_t can_sja_receive(CanBusClientState *client, const 
> qemu_can_frame *frames,
>      if (frames_cnt <= 0) {
>          return 0;
>      }
> +    if (frame->flags && QEMU_CAN_FRMF_TYPE_FD) {
> +        if (DEBUG_FILTER) {
> +            can_display_msg("[cansja]: ignor fd frame ", frame);
> +        }
> +        return 1;
> +    }
> +
>      if (DEBUG_FILTER) {
>          can_display_msg("[cansja]: receive ", frame);
>      }