net/ncsi : Add payload to be 32-bit aligned to fix dropped packets

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: ee912e175a52 ("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>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ncsi/ncsi-cmd.c b/net/ncsi/ncsi-cmd.c
index ba9ae482141b0f4be035085a6f9427cf581cf169..dda8b76b77988ab422afce64470e924a90124809 100644 (file)
--- a/net/ncsi/ncsi-cmd.c
+++ b/net/ncsi/ncsi-cmd.c
@@ -18,6 +18,8 @@
 #include "internal.h"
 #include "ncsi-pkt.h"
 
+static 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);