[PATCH v2] net/ncsi: Ensure 32-bit boundary for data cksum

From: Terry S. Duncan
Date: Mon Aug 19 2019 - 20:25:03 EST


The NCSI spec indicates that if the data does not end on a 32 bit
boundary, one to three padding bytes equal to 0x00 shall be present to
align the checksum field to a 32-bit boundary.

Signed-off-by: Terry S. Duncan <terry.s.duncan@xxxxxxxxxxxxxxx>
---
net/ncsi/ncsi-cmd.c | 2 +-
net/ncsi/ncsi-rsp.c | 9 ++++++---
2 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/net/ncsi/ncsi-cmd.c b/net/ncsi/ncsi-cmd.c
index 5c3fad8cba57..eab4346b0a39 100644
--- a/net/ncsi/ncsi-cmd.c
+++ b/net/ncsi/ncsi-cmd.c
@@ -54,7 +54,7 @@ static void ncsi_cmd_build_header(struct ncsi_pkt_hdr *h,
checksum = ncsi_calculate_checksum((unsigned char *)h,
sizeof(*h) + nca->payload);
pchecksum = (__be32 *)((void *)h + sizeof(struct ncsi_pkt_hdr) +
- nca->payload);
+ ALIGN(nca->payload, 4));
*pchecksum = htonl(checksum);
}

diff --git a/net/ncsi/ncsi-rsp.c b/net/ncsi/ncsi-rsp.c
index 7581bf919885..d876bd55f356 100644
--- a/net/ncsi/ncsi-rsp.c
+++ b/net/ncsi/ncsi-rsp.c
@@ -47,7 +47,8 @@ static int ncsi_validate_rsp_pkt(struct ncsi_request *nr,
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");
+ "NCSI: non zero response/reason code %04xh, %04xh\n",
+ ntohs(h->code), ntohs(h->reason));
return -EPERM;
}

@@ -55,7 +56,7 @@ static int ncsi_validate_rsp_pkt(struct ncsi_request *nr,
* sender doesn't support checksum according to NCSI
* specification.
*/
- pchecksum = (__be32 *)((void *)(h + 1) + payload - 4);
+ pchecksum = (__be32 *)((void *)(h + 1) + ALIGN(payload, 4) - 4);
if (ntohl(*pchecksum) == 0)
return 0;

@@ -63,7 +64,9 @@ static int ncsi_validate_rsp_pkt(struct ncsi_request *nr,
sizeof(*h) + payload - 4);

if (*pchecksum != htonl(checksum)) {
- netdev_dbg(nr->ndp->ndev.dev, "NCSI: checksum mismatched\n");
+ netdev_dbg(nr->ndp->ndev.dev,
+ "NCSI: checksum mismatched; recd: %08x calc: %08x\n",
+ *pchecksum, htonl(checksum));
return -EINVAL;
}

--
2.17.1