Re: [PATCH v2] RDMA/rxe: Implement packet length validation on responder

["lizhijian@fujitsu.com" <lizhijian@fujitsu.com>]

On 07/11/2022 13:53, Daisuke Matsuda wrote:
> The function check_length() is supposed to check the length of inbound
> packets on responder, but it actually has been a stub since the driver was
> born. Let it check the payload length and the DMA length.
> 
> Signed-off-by: Daisuke Matsuda <matsuda-daisuke@fujitsu.com>

Looks good to me

Reviewed-by: Li Zhijian <lizhijian@fujitsu.com>




> ---
> FOR REVIEWERS
>    I referred to IB Specification Vol 1-Revision-1.5 to create this patch.
>    Please see 9.7.4.1.6 (page.330).
> 
> v2: Fixed the conditional for 'last' packets. Thanks, Zhijian.
> 
>   drivers/infiniband/sw/rxe/rxe_resp.c | 34 ++++++++++++++++++++++------
>   1 file changed, 27 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/infiniband/sw/rxe/rxe_resp.c b/drivers/infiniband/sw/rxe/rxe_resp.c
> index c32bc12cc82f..382d2053db43 100644
> --- a/drivers/infiniband/sw/rxe/rxe_resp.c
> +++ b/drivers/infiniband/sw/rxe/rxe_resp.c
> @@ -393,16 +393,36 @@ static enum resp_states check_resource(struct rxe_qp *qp,
>   static enum resp_states check_length(struct rxe_qp *qp,
>   				     struct rxe_pkt_info *pkt)
>   {
> -	switch (qp_type(qp)) {
> -	case IB_QPT_RC:
> -		return RESPST_CHK_RKEY;
> +	int mtu = qp->mtu;
> +	u32 payload = payload_size(pkt);
> +	u32 dmalen = reth_len(pkt);
>   
> -	case IB_QPT_UC:
> -		return RESPST_CHK_RKEY;
> +	/* RoCEv2 packets do not have LRH.
> +	 * Let's skip checking it.
> +	 */
>   
> -	default:
> -		return RESPST_CHK_RKEY;
> +	if ((pkt->opcode & RXE_START_MASK) &&
> +	    (pkt->opcode & RXE_END_MASK)) {
> +		/* "only" packets */
> +		if (payload > mtu)
> +			return RESPST_ERR_LENGTH;
> +	} else if ((pkt->opcode & RXE_START_MASK) ||
> +		   (pkt->opcode & RXE_MIDDLE_MASK)) {
> +		/* "first" or "middle" packets */
> +		if (payload != mtu)
> +			return RESPST_ERR_LENGTH;
> +	} else if (pkt->opcode & RXE_END_MASK) {
> +		/* "last" packets */
> +		if ((payload == 0) || (payload > mtu))
> +			return RESPST_ERR_LENGTH;
> +	}
> +
> +	if (pkt->opcode & (RXE_WRITE_MASK | RXE_READ_MASK)) {
> +		if (dmalen > (1 << 31))
> +			return RESPST_ERR_LENGTH;
>   	}
> +
> +	return RESPST_CHK_RKEY;
>   }
>   
>   static enum resp_states check_rkey(struct rxe_qp *qp,