* [PATCH v6] Add payload to be 32-bit aligned to fix dropped packets
@ 2021-11-17 7:55 Kumar Thangavel
2021-11-17 18:23 ` Jakub Kicinski
0 siblings, 1 reply; 3+ messages in thread
From: Kumar Thangavel @ 2021-11-17 7:55 UTC (permalink / raw)
To: Samuel Mendoza-Jonas, David S. Miller, Jakub Kicinski
Cc: linux-aspeed, netdev, openbmc, Amithash Prasad, velumanit, patrickw3
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.
Fixes: fb4ee67529ff ("net/ncsi: Add NCSI OEM command support")
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>
---
v6:
- Updated type of padding_bytes variable
- Updated type of payload variable
- Seperated variable declarations and code
v5:
- Added Fixes tag
- Added const variable for padding_bytes
v4:
- Used 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 | 24 ++++++++++++++++--------
1 file changed, 16 insertions(+), 8 deletions(-)
diff --git a/net/ncsi/ncsi-cmd.c b/net/ncsi/ncsi-cmd.c
index ba9ae482141b..78376d88e788 100644
--- a/net/ncsi/ncsi-cmd.c
+++ b/net/ncsi/ncsi-cmd.c
@@ -18,6 +18,8 @@
#include "internal.h"
#include "ncsi-pkt.h"
+const int padding_bytes = 26;
+
u32 ncsi_calculate_checksum(unsigned char *data, int len)
{
u32 checksum = 0;
@@ -213,12 +215,17 @@ static int ncsi_cmd_handler_oem(struct sk_buff *skb,
{
struct ncsi_cmd_oem_pkt *cmd;
unsigned int len;
+ int payload;
+ /* 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
+ */
+ 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, padding_bytes);
cmd = skb_put_zero(skb, len);
memcpy(&cmd->mfr_id, nca->data, nca->payload);
@@ -272,6 +279,7 @@ 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 +289,14 @@ 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, padding_bytes);
/* Allocate skb */
skb = alloc_skb(len, GFP_ATOMIC);
--
2.17.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH v6] Add payload to be 32-bit aligned to fix dropped packets
2021-11-17 7:55 [PATCH v6] Add payload to be 32-bit aligned to fix dropped packets Kumar Thangavel
@ 2021-11-17 18:23 ` Jakub Kicinski
2021-11-18 7:37 ` Kumar Thangavel
0 siblings, 1 reply; 3+ messages in thread
From: Jakub Kicinski @ 2021-11-17 18:23 UTC (permalink / raw)
To: Kumar Thangavel
Cc: linux-aspeed, netdev, openbmc, Amithash Prasad, patrickw3,
Samuel Mendoza-Jonas, velumanit, David S. Miller
On Wed, 17 Nov 2021 13:25:13 +0530 Kumar Thangavel wrote:
> +const int padding_bytes = 26;
net/ncsi/ncsi-cmd.c:21:11: warning: symbol 'padding_bytes' was not declared. Should it be static?
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH v6] Add payload to be 32-bit aligned to fix dropped packets
2021-11-17 18:23 ` Jakub Kicinski
@ 2021-11-18 7:37 ` Kumar Thangavel
0 siblings, 0 replies; 3+ messages in thread
From: Kumar Thangavel @ 2021-11-18 7:37 UTC (permalink / raw)
To: Jakub Kicinski
Cc: linux-aspeed, Networking, OpenBMC Maillist, Amithash Prasad,
patrickw3, Samuel Mendoza-Jonas, velumanit, David S. Miller
[-- Attachment #1: Type: text/plain, Size: 279 bytes --]
On Wed, Nov 17, 2021 at 11:53 PM Jakub Kicinski <kuba@kernel.org> wrote:
> On Wed, 17 Nov 2021 13:25:13 +0530 Kumar Thangavel wrote:
> > +const int padding_bytes = 26;
>
> net/ncsi/ncsi-cmd.c:21:11: warning: symbol 'padding_bytes' was not
> declared. Should it be static?
Ack.
[-- Attachment #2: Type: text/html, Size: 604 bytes --]
^ permalink raw reply [flat|nested] 3+ messages in thread
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2021-11-17 18:23 ` Jakub Kicinski
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