[v4] Add payload to be 32-bit aligned to fix dropped packets

Update NC-SI command handler (both standard and OEM) to take into
account of payload paddings in allocating skb (in case of payload
size is not 32-bit aligned).

The checksum field follows payload field, without taking payload
padding into account can cause checksum being truncated, leading to
dropped packets.

Signed-off-by: Kumar Thangavel <thangavel.k@hcl.com>
Acked-by: Samuel Mendoza-Jonas <sam@mendozajonas.com>
Reviewed-by: Paul Menzel <pmenzel@molgen.mpg.de>

---
  v4:
   - Updated existing macro for max function

  v3:
   - Added Macro for MAX
   - Fixed the missed semicolon

  v2:
   - Added NC-SI spec version and section
   - Removed blank line
   - corrected spellings

  v1:
   - Initial draft

---
 net/ncsi/ncsi-cmd.c | 21 +++++++++++++--------
 1 file changed, 13 insertions(+), 8 deletions(-)

Hi All,

    Could you please review the patch and provide your feedback?

Thanks,
Kumar.

On Thu, Oct 28, 2021 at 3:20 PM Kumar Thangavel <
kumarthangavel.hcl@gmail.com> wrote:

> Update NC-SI command handler (both standard and OEM) to take into
> account of payload paddings in allocating skb (in case of payload
> size is not 32-bit aligned).
>
> The checksum field follows payload field, without taking payload
> padding into account can cause checksum being truncated, leading to
> dropped packets.
>
> Signed-off-by: Kumar Thangavel <thangavel.k@hcl.com>
> Acked-by: Samuel Mendoza-Jonas <sam@mendozajonas.com>
> Reviewed-by: Paul Menzel <pmenzel@molgen.mpg.de>
>
> ---
>   v4:
>    - Updated existing macro for max function
>
>   v3:
>    - Added Macro for MAX
>    - Fixed the missed semicolon
>
>   v2:
>    - Added NC-SI spec version and section
>    - Removed blank line
>    - corrected spellings
>
>   v1:
>    - Initial draft
>
> ---
>  net/ncsi/ncsi-cmd.c | 21 +++++++++++++--------
>  1 file changed, 13 insertions(+), 8 deletions(-)
>
> diff --git a/net/ncsi/ncsi-cmd.c b/net/ncsi/ncsi-cmd.c
> index ba9ae482141b..e44fe138c20f 100644
> --- a/net/ncsi/ncsi-cmd.c
> +++ b/net/ncsi/ncsi-cmd.c
> @@ -213,12 +213,16 @@ static int ncsi_cmd_handler_oem(struct sk_buff *skb,
>  {
>         struct ncsi_cmd_oem_pkt *cmd;
>         unsigned int len;
> +       /* NC-SI spec DSP_0222_1.2.0, section 8.2.2.2
> +        * requires payload to be padded with 0 to
> +        * 32-bit boundary before the checksum field.
> +        * Ensure the padding bytes are accounted for in
> +        * skb allocation
> +        */
>
> +       unsigned short payload = ALIGN(nca->payload, 4);
>         len = sizeof(struct ncsi_cmd_pkt_hdr) + 4;
> -       if (nca->payload < 26)
> -               len += 26;
> -       else
> -               len += nca->payload;
> +       len += max(payload, 26);
>
>         cmd = skb_put_zero(skb, len);
>         memcpy(&cmd->mfr_id, nca->data, nca->payload);
> @@ -272,6 +276,7 @@ static struct ncsi_request *ncsi_alloc_command(struct
> ncsi_cmd_arg *nca)
>         struct net_device *dev = nd->dev;
>         int hlen = LL_RESERVED_SPACE(dev);
>         int tlen = dev->needed_tailroom;
> +       int payload;
>         int len = hlen + tlen;
>         struct sk_buff *skb;
>         struct ncsi_request *nr;
> @@ -281,14 +286,14 @@ static struct ncsi_request
> *ncsi_alloc_command(struct ncsi_cmd_arg *nca)
>                 return NULL;
>
>         /* NCSI command packet has 16-bytes header, payload, 4 bytes
> checksum.
> +        * Payload needs padding so that the checksum field following
> payload is
> +        * aligned to 32-bit boundary.
>          * The packet needs padding if its payload is less than 26 bytes to
>          * meet 64 bytes minimal ethernet frame length.
>          */
>         len += sizeof(struct ncsi_cmd_pkt_hdr) + 4;
> -       if (nca->payload < 26)
> -               len += 26;
> -       else
> -               len += nca->payload;
> +       payload = ALIGN(nca->payload, 4);
> +       len += max(payload, 26);
>
>         /* Allocate skb */
>         skb = alloc_skb(len, GFP_ATOMIC);
> --
> 2.17.1
>
>

On Wed, 3 Nov 2021 20:41:56 +0530 Kumar Thangavel wrote:
>     Could you please review the patch and provide your feedback?

You missed CCing netdev@ again. You need to CC the mailing list 
to get the patch considered for merging.

Hi Jakub,

Thanks for your response.

Somehow, My mails are not delivered to netdev@vger.kernel.org.

So, I removed it in my last 2 patchsets.

I will try again to CCing netdev@vger.kernel.org.

Thanks,
Kumar.



On Wed, Nov 3, 2021 at 9:19 PM Jakub Kicinski <kuba@kernel.org> wrote:

> On Wed, 3 Nov 2021 20:41:56 +0530 Kumar Thangavel wrote:
> >     Could you please review the patch and provide your feedback?
>
> You missed CCing netdev@ again. You need to CC the mailing list
> to get the patch considered for merging.
>

On Wed, 3 Nov 2021 21:43:03 +0530 Kumar Thangavel wrote:
> Hi Jakub,
> 
> Thanks for your response.
> 
> Somehow, My mails are not delivered to netdev@vger.kernel.org.
> 
> So, I removed it in my last 2 patchsets.
> 
> I will try again to CCing netdev@vger.kernel.org.

For normal replies you need to use plain text, not HTML. The mailing
list rejects HTML emails. But the patch should go thru, we'll see.

Ok Sure Jakub.

Thanks,
Kumar.

On Wed, Nov 3, 2021 at 9:46 PM Jakub Kicinski <kuba@kernel.org> wrote:

> On Wed, 3 Nov 2021 21:43:03 +0530 Kumar Thangavel wrote:
> > Hi Jakub,
> >
> > Thanks for your response.
> >
> > Somehow, My mails are not delivered to netdev@vger.kernel.org.
> >
> > So, I removed it in my last 2 patchsets.
> >
> > I will try again to CCing netdev@vger.kernel.org.
>
> For normal replies you need to use plain text, not HTML. The mailing
> list rejects HTML emails. But the patch should go thru, we'll see.
>