[U-Boot] [PATCH]Fix checksum to handle odd-length packet

[Greg Ren]

Ah. I just realize that the endianess can be supported as simple as:

In stead of this:
               xsum += (*p & 0xff00);
Use this:
               xsum += (*p & ntohs(0xff00));

Greg Ren

-----Original Message-----
From: Wolfgang Denk [mailto:wd at denx.de] 
Sent: Thursday, December 03, 2009 3:31 AM
To: Greg Ren
Cc: u-boot at lists.denx.de
Subject: Re: [U-Boot] [PATCH]Fix checksum to handle odd-length packet

Dear "Greg Ren",

In message <CB2DD11991B27C4F99935E6229450D3204E5CB91 at STORK.scenix.com>
you wrote:
> 
> I am new to u-boot and got assignment to debug some networking issue.
I
> traced the checksum failure and was able to fix it with the patch
below.

It would be important to know on which system(s) you have actually
tested your patch - and on which you experienced any issues in the
first place. Please mention CPU, board, and network driver used.

> The patch is a git commit log from my local git reposite.
> 
> Thanks for your time and advice.
> 
> % git show cffd5fb03e0c3f116cce9f3ff825c5445a1eca3f

Please use git-format-patch / git-send-email to submit patches, see
http://www.denx.de/wiki/U-Boot/Patches for details.


> @@ -1420,12 +1420,12 @@ NetReceive(volatile uchar * inpkt, int len)
>                                 ip->ip_off = 0;
>                                 NetCopyIP((void*)&ip->ip_dst,
> &ip->ip_src);
>                                 NetCopyIP((void*)&ip->ip_src,
> &NetOurIP);
> -                               ip->ip_sum = ~NetCksum((uchar *)ip,
> IP_HDR_SIZE_NO_UDP >> 1);
> +                               ip->ip_sum = ~NetCksum((uchar *)ip,
> IP_HDR_SIZE_NO_UDP);

Your mailer has line-wrapped the patch which makes it useless.

> +       if (len == 1) {
> +               xsum += (*p & 0xff00);

I doubt that this code is endianess-clean.

Best regards,

Wolfgang Denk

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