Re: [PATCH v4] Add payload to be 32-bit aligned to fix dropped packets
From: Denis Kirjanov <hidden>
Date: 2021-11-10 13:58:26
Also in:
linux-aspeed, openbmc
11/10/21 12:54 PM, Kumar Thangavel пишет:
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.
Please add Fixes tag
quoted hunk ↗ jump to hunk
Signed-off-by: Kumar Thangavel <redacted> Acked-by: Samuel Mendoza-Jonas <sam@mendozajonas.com> Reviewed-by: Paul Menzel <redacted> --- 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;
Would be nice to have a constant
quoted hunk ↗ jump to hunk
- 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);