Andrew Morton wrote:
> On Mon, 4 Feb 2008 13:46:13 -0800 (PST)
> [EMAIL PROTECTED] wrote:
>>
>> Open a tun device as type TUN, set the TUN_NO_PI flag, and try sending an
>> IPv6
>> packet. The packet appears at the interface under tcpdumps, but propagates no
>> further. This is because the default protocol info used for tun devices where
>> the TUN_NO_PI flag is set assumes IPv4 as can be seen by the initialization
>> at
>> the top of the tun_get_user function in drivers/net/tun.c file given by
>>
>> struct tun_pi pi = { 0, __constant_htons(ETH_P_IP) };
>>
>> This can easily be fixed by adding a quick check at the top of tun_get_user.
>> Basically the code that used to read
>>
>> if (!(tun->flags & TUN_NO_PI)) {
>> if ((len -= sizeof(pi)) > count)
>> return -EINVAL;
>>
>> if(memcpy_fromiovec((void *)&pi, iv, sizeof(pi)))
>> return -EFAULT;
>> }
>>
>> when changed to read
>>
>> if (!(tun->flags & TUN_NO_PI)) {
>> if ((len -= sizeof(pi)) > count)
>> return -EINVAL;
>>
>> if(memcpy_fromiovec((void *)&pi, iv, sizeof(pi)))
>> return -EFAULT;
>> }
>> else {
>> /* Fixup default pi if IPv6 rather than IPv4 */
>> if (((tun->flags & TUN_TYPE_MASK) == TUN_TUN_DEV) &&
>> (*(char *)(iv->iov_base) == 0x60)) {
>> pi.proto = __constant_htons(ETH_P_IPV6);
>> }
>> }
>>
>> fixes the problem.
>>
>> How do we get this in as part of the maintained codebase??
>>
>
> Please email a tested patch prepared as described in
>
> Documentation/SubmittingPatches
> Documentation/SubmitChecklist
> http://www.zip.com.au/~akpm/linux/patches/stuff/tpp.txt
>
> to
>
> Maxim Krasnyansky <[EMAIL PROTECTED]>
> "David S. Miller" <[EMAIL PROTECTED]>
> Andrew Morton <[EMAIL PROTECTED]>
> netdev@vger.kernel.org
btw I'd be ok with this fix. But I guess the questions is why not use
struct tun_pi in the apps instead ?
Max
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