static int ncsi_validate_rsp_pkt(struct ncsi_request *nr,
unsigned short payload)
{
struct ncsi_rsp_pkt_hdr *h;
u32 checksum;
__be32 *pchecksum;
/* Check NCSI packet header. We don't need validate
* the packet type, which should have been checked
* before calling this function.
*/
h = (struct ncsi_rsp_pkt_hdr *)skb_network_header(nr->rsp);
if (h->common.revision != NCSI_PKT_REVISION) {
netdev_dbg(nr->ndp->ndev.dev,
"NCSI: unsupported header revision\n");
return -EINVAL;
}
if (ntohs(h->common.length) != payload) {
netdev_dbg(nr->ndp->ndev.dev,
"NCSI: payload length mismatched\n");
return -EINVAL;
}
/* Check on code and reason */
if (ntohs(h->code) != NCSI_PKT_RSP_C_COMPLETED ||
ntohs(h->reason) != NCSI_PKT_RSP_R_NO_ERROR) {
netdev_dbg(nr->ndp->ndev.dev,
"NCSI: non zero response/reason code\n");
return -EPERM;
}
/* Validate checksum, which might be zeroes if the
* sender doesn't support checksum according to NCSI
* specification.
*/
pchecksum = (__be32 *)((void *)(h + 1) + payload - 4);
if (ntohl(*pchecksum) == 0)
return 0;
checksum = ncsi_calculate_checksum((unsigned char *)h,
sizeof(*h) + payload - 4);
if (*pchecksum != htonl(checksum)) {
netdev_dbg(nr->ndp->ndev.dev, "NCSI: checksum mismatched\n");
return -EINVAL;
}
return 0;
}
/* This function should be called after the data area has been
* populated completely.
*/
static void ncsi_cmd_build_header(struct ncsi_pkt_hdr *h,
struct ncsi_cmd_arg *nca)
{
u32 checksum;
__be32 *pchecksum;
h->mc_id = 0;
h->revision = NCSI_PKT_REVISION;
h->reserved = 0;
h->id = nca->id;
h->type = nca->type;
h->channel = NCSI_TO_CHANNEL(nca->package,
nca->channel);
h->length = htons(nca->payload);
h->reserved1[0] = 0;
h->reserved1[1] = 0;
/* Fill with calculated checksum */
checksum = ncsi_calculate_checksum((unsigned char *)h,
sizeof(*h) + nca->payload);
pchecksum = (__be32 *)((void *)h + sizeof(struct ncsi_pkt_hdr) +
nca->payload);
*pchecksum = htonl(checksum);
}
