Hi Justin,
Please see comments below
-Vijay
> > > diff --git a/net/ncsi/ncsi-cmd.c b/net/ncsi/ncsi-cmd.c
> > > index 7567ca63aae2..2f98533eba46 100644
> > > --- a/net/ncsi/ncsi-cmd.c
> > > +++ b/net/ncsi/ncsi-cmd.c
> > > @@ -211,6 +211,26 @@ static int ncsi_cmd_handler_snfc(struct sk_buff
*skb,
> > > return 0;
> > > }
> > >
> > > +static int ncsi_cmd_handler_oem(struct sk_buff *skb,
> > > + struct ncsi_cmd_arg *nca)
> > > +{
> > > + struct ncsi_cmd_oem_pkt *cmd;
>
> >OEM command doesn't not have the fixed data size. Should we use pointer
instead?
> >struct ncsi_cmd_oem_pkt {
> > struct ncsi_cmd_pkt_hdr cmd; /* Command header */
> > __be32 mfr_id; /* Manufacture ID */
> > unsigned char *data; /* OEM Payload Data */
> >};
> Yes, I agree that OEM command doesn't have fixed data but to map to
skbuff structure,
> I have defined above structure as per NCSI spec, We can certainly have a
MAX_DATA_LEN define.
The spec only defines manufacture ID field and the start offset of vendor
data.
If we just want to point to the vendor data, we don't need to specify the
max length and
we can use flexible array as the last member (correct the typo above).
struct ncsi_cmd_oem_pkt {
struct ncsi_cmd_pkt_hdr cmd; /* Command header */
__be32 mfr_id; /* Manufacture ID */
unsigned char data[]; /* OEM Payload Data */
};
I agree and will add this change.
> > > + unsigned int len;
> > > +
> > > + len = sizeof(struct ncsi_cmd_pkt_hdr) + 4;
> > > + if (nca->payload < 26)
> > > + len += 26;
>
> >Why does it add 26? I knew the other place in ncsi_alloc_command() is
also add 26.
> >If it is less than 26, then it should be a fixed size of structure
ncsi_cmd_pkt (46), right?
> It adds 26 because It has already assigned len to hdr+4 which is 16+4 =
20 bytes. By
> adding 26 it makes it to 46. I am just being consistent with other
portion of code.
>
> > > + else
> > > + len += nca->payload;
> > > +
> > > + cmd = skb_put_zero(skb, len);
> > > + cmd->mfr_id = nca->dwords[0];
> > > + memcpy(cmd->data, &nca->dwords[1], nca->payload - 4);
>
> >Netlink request is using the new nca->data pointer to pass the data as
the request payload
> >is not the same size and some command payload is bigger than 16 bytes.
> >Will you consider to use the same data pointer? So, we don't need to
have a checking here.
> >If the command is used less than 16 bytes, we can simply assigned
&nca->bytes[0] to it.
> To keep original structure, we can change 16 bytes to MAX_DATA_LEN. Or I
don't see any issue in
> Copying data from data pointer from nca but user needs to be aware if it
is less than 16 bytes then
> use bytes or use data pointer. To keep it simple, we should simply define
MAX_LEN.
I use the pointer to avoid copying the data again. OEM handler can always
process the flexible payload
through the data pointer. It can depend on the caller to use
stack/allocated buffer/nca buffer and
it will be straight forward if all OEM stuff is using the data pointer to
process the flexible
payload.
Do we use data pointer for payload less than 16 bytes as well in OEM. We copy
data only once while adding to skbuff.
I have no issue, I will make this change but wait for other comments.
>
> > > diff --git a/net/ncsi/ncsi-pkt.h b/net/ncsi/ncsi-pkt.h
> > > index 91b4b66438df..1f338386810d 100644
> > > --- a/net/ncsi/ncsi-pkt.h
> > > +++ b/net/ncsi/ncsi-pkt.h
> > > @@ -151,6 +151,22 @@ struct ncsi_cmd_snfc_pkt {
> > > unsigned char pad[22];
> > > };
> > >
> > > +/* OEM Request Command as per NCSI Specification */
> > > +struct ncsi_cmd_oem_pkt {
> > > + struct ncsi_cmd_pkt_hdr cmd; /* Command header */
> > > + __be32 mfr_id; /* Manufacture ID */
> > > + unsigned char data[64]; /* OEM Payload Data */
> > > + __be32 checksum; /* Checksum */
> > > +};
> > > +
> > > +/* OEM Response Packet as per NCSI Specification */
> > > +struct ncsi_rsp_oem_pkt {
> > > + struct ncsi_rsp_pkt_hdr rsp; /* Command header */
> > > + __be32 mfr_id; /* Manufacture ID */
> > > + unsigned char data[64]; /* Payload data */
> > > + __be32 checksum; /* Checksum */
> > > +};
> > > +
>
> >OEM command doesn't not have the fixed response data size too.
> >Should we use pointer instead?
>
> Here also we can define MAX_DATA_LEN because data pointer won't map to
skb directly.
Suggest to change as below due to the flexible response.
struct ncsi_rsp_oem_pkt {
struct ncsi_rsp_pkt_hdr rsp; /* Command header */
__be32 mfr_id; /* Manufacture ID */
unsigned char data[]; /* Payload data */
};
Sure done.
