Patchwork [RFC,1/4] netfilter: ip6t_NPT: Fix checksuming.

login
register
mail settings
Submitter Ulrich Weber
Date Jan. 29, 2013, 2:42 p.m.
Message ID <5107DFDF.4050504@gmail.com>
Download mbox | patch
Permalink /patch/216557/
State Accepted
Headers show

Comments

Ulrich Weber - Jan. 29, 2013, 2:42 p.m.
Hi Yoshofuji,

thanks for your patches! If I add a onces complement
to the return value of csum_fold() it works for my setup.

Cheers
Ulrich

On 01/26/13 19:37, YOSHIFUJI Hideaki wrote:
> Cast __wsum from/to __sum16 is wrong.  Instead, apply appropriate
> conversion function: csum_unfold() or csum_fold().
>
> Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
> ---
>  net/ipv6/netfilter/ip6t_NPT.c |    6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/net/ipv6/netfilter/ip6t_NPT.c b/net/ipv6/netfilter/ip6t_NPT.c
> index 7302b0b..3ff281b 100644
> --- a/net/ipv6/netfilter/ip6t_NPT.c
> +++ b/net/ipv6/netfilter/ip6t_NPT.c
> @@ -30,7 +30,7 @@ static int ip6t_npt_checkentry(const struct xt_tgchk_param *par)
>  				(__force __wsum)npt->dst_pfx.in6.s6_addr16[i]);
>  	}
>  
> -	npt->adjustment = (__force __sum16) csum_sub(src_sum, dst_sum);
> +	npt->adjustment = csum_fold(csum_sub(src_sum, dst_sum));
>  	return 0;
>  }
>  
> @@ -66,8 +66,8 @@ static bool ip6t_npt_map_pfx(const struct ip6t_npt_tginfo *npt,
>  			return false;
>  	}
>  
> -	sum = (__force __sum16) csum_add((__force __wsum)addr->s6_addr16[idx],
> -			 npt->adjustment);
> +	sum = csum_fold(csum_add(csum_unfold((__force __sum16)addr->s6_addr16[idx]),
> +				 csum_unfold(npt->adjustment)));
>  	if (sum == CSUM_MANGLED_0)
>  		sum = 0;
>  	*(__force __sum16 *)&addr->s6_addr16[idx] = sum;
Pablo Neira - Jan. 31, 2013, 10:04 a.m.
Hi,

On Tue, Jan 29, 2013 at 03:42:39PM +0100, Ulrich Weber wrote:
> Hi Yoshofuji,
> 
> thanks for your patches! If I add a onces complement
> to the return value of csum_fold() it works for my setup.

Any consensus on the fix for this? I'd like to have some solution into
3.8-rc.

Thanks.

> On 01/26/13 19:37, YOSHIFUJI Hideaki wrote:
> > Cast __wsum from/to __sum16 is wrong.  Instead, apply appropriate
> > conversion function: csum_unfold() or csum_fold().
> >
> > Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
> > ---
> >  net/ipv6/netfilter/ip6t_NPT.c |    6 +++---
> >  1 file changed, 3 insertions(+), 3 deletions(-)
> >
> > diff --git a/net/ipv6/netfilter/ip6t_NPT.c b/net/ipv6/netfilter/ip6t_NPT.c
> > index 7302b0b..3ff281b 100644
> > --- a/net/ipv6/netfilter/ip6t_NPT.c
> > +++ b/net/ipv6/netfilter/ip6t_NPT.c
> > @@ -30,7 +30,7 @@ static int ip6t_npt_checkentry(const struct xt_tgchk_param *par)
> >  				(__force __wsum)npt->dst_pfx.in6.s6_addr16[i]);
> >  	}
> >  
> > -	npt->adjustment = (__force __sum16) csum_sub(src_sum, dst_sum);
> > +	npt->adjustment = csum_fold(csum_sub(src_sum, dst_sum));
> >  	return 0;
> >  }
> >  
> > @@ -66,8 +66,8 @@ static bool ip6t_npt_map_pfx(const struct ip6t_npt_tginfo *npt,
> >  			return false;
> >  	}
> >  
> > -	sum = (__force __sum16) csum_add((__force __wsum)addr->s6_addr16[idx],
> > -			 npt->adjustment);
> > +	sum = csum_fold(csum_add(csum_unfold((__force __sum16)addr->s6_addr16[idx]),
> > +				 csum_unfold(npt->adjustment)));
> >  	if (sum == CSUM_MANGLED_0)
> >  		sum = 0;
> >  	*(__force __sum16 *)&addr->s6_addr16[idx] = sum;
> 

> From 40e0c6d86514a8dcc80f18fbe8a2945c6ee78f6d Mon Sep 17 00:00:00 2001
> From: Ulrich Weber <ulrich.weber@sophos.com>
> Date: Tue, 29 Jan 2013 15:24:21 +0100
> Subject: [PATCH] netfilter: ip6t_NTP: Use onces complement of csum_fold
> 
> we need a 16bit value but not folded
> 
> Signed-off-by: Ulrich Weber <ulrich.weber@sophos.com>
> ---
>  net/ipv6/netfilter/ip6t_NPT.c |    6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/net/ipv6/netfilter/ip6t_NPT.c b/net/ipv6/netfilter/ip6t_NPT.c
> index 74e171d..61a9b95 100644
> --- a/net/ipv6/netfilter/ip6t_NPT.c
> +++ b/net/ipv6/netfilter/ip6t_NPT.c
> @@ -35,7 +35,7 @@ static int ip6t_npt_checkentry(const struct xt_tgchk_param *par)
>  	src_sum = csum_partial(&npt->src_pfx.in6, sizeof(npt->src_pfx.in6), 0);
>  	dst_sum = csum_partial(&npt->dst_pfx.in6, sizeof(npt->dst_pfx.in6), 0);
>  
> -	npt->adjustment = csum_fold(csum_sub(src_sum, dst_sum));
> +	npt->adjustment = ~csum_fold(csum_sub(src_sum, dst_sum));
>  	return 0;
>  }
>  
> @@ -71,8 +71,8 @@ static bool ip6t_npt_map_pfx(const struct ip6t_npt_tginfo *npt,
>  			return false;
>  	}
>  
> -	sum = csum_fold(csum_add(csum_unfold((__force __sum16)addr->s6_addr16[idx]),
> -				 csum_unfold(npt->adjustment)));
> +	sum = ~csum_fold(csum_add(csum_unfold((__force __sum16)addr->s6_addr16[idx]),
> +				  csum_unfold(npt->adjustment)));
>  	if (sum == CSUM_MANGLED_0)
>  		sum = 0;
>  	*(__force __sum16 *)&addr->s6_addr16[idx] = sum;
> -- 
> 1.7.9.5
> 

--
To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Ulrich Weber - Jan. 31, 2013, 3:59 p.m.
From my side, apply yoshofuji patches and my
onces complement patch, that worked for me ;)

I can do some more testing tomorrow with different
addresses and ranges if nobody else finds time...

Cheers
  Ulrich


On 01/31/13 11:04, Pablo Neira Ayuso wrote:
> Hi,
>
> On Tue, Jan 29, 2013 at 03:42:39PM +0100, Ulrich Weber wrote:
>> Hi Yoshofuji,
>>
>> thanks for your patches! If I add a onces complement
>> to the return value of csum_fold() it works for my setup.
> Any consensus on the fix for this? I'd like to have some solution into
> 3.8-rc.
>
> Thanks.
>
>> On 01/26/13 19:37, YOSHIFUJI Hideaki wrote:
>>> Cast __wsum from/to __sum16 is wrong.  Instead, apply appropriate
>>> conversion function: csum_unfold() or csum_fold().
>>>
>>> Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
>>> ---
>>>   net/ipv6/netfilter/ip6t_NPT.c |    6 +++---
>>>   1 file changed, 3 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/net/ipv6/netfilter/ip6t_NPT.c b/net/ipv6/netfilter/ip6t_NPT.c
>>> index 7302b0b..3ff281b 100644
>>> --- a/net/ipv6/netfilter/ip6t_NPT.c
>>> +++ b/net/ipv6/netfilter/ip6t_NPT.c
>>> @@ -30,7 +30,7 @@ static int ip6t_npt_checkentry(const struct xt_tgchk_param *par)
>>>   				(__force __wsum)npt->dst_pfx.in6.s6_addr16[i]);
>>>   	}
>>>   
>>> -	npt->adjustment = (__force __sum16) csum_sub(src_sum, dst_sum);
>>> +	npt->adjustment = csum_fold(csum_sub(src_sum, dst_sum));
>>>   	return 0;
>>>   }
>>>   
>>> @@ -66,8 +66,8 @@ static bool ip6t_npt_map_pfx(const struct ip6t_npt_tginfo *npt,
>>>   			return false;
>>>   	}
>>>   
>>> -	sum = (__force __sum16) csum_add((__force __wsum)addr->s6_addr16[idx],
>>> -			 npt->adjustment);
>>> +	sum = csum_fold(csum_add(csum_unfold((__force __sum16)addr->s6_addr16[idx]),
>>> +				 csum_unfold(npt->adjustment)));
>>>   	if (sum == CSUM_MANGLED_0)
>>>   		sum = 0;
>>>   	*(__force __sum16 *)&addr->s6_addr16[idx] = sum;
>>  From 40e0c6d86514a8dcc80f18fbe8a2945c6ee78f6d Mon Sep 17 00:00:00 2001
>> From: Ulrich Weber <ulrich.weber@sophos.com>
>> Date: Tue, 29 Jan 2013 15:24:21 +0100
>> Subject: [PATCH] netfilter: ip6t_NTP: Use onces complement of csum_fold
>>
>> we need a 16bit value but not folded
>>
>> Signed-off-by: Ulrich Weber <ulrich.weber@sophos.com>
>> ---
>>   net/ipv6/netfilter/ip6t_NPT.c |    6 +++---
>>   1 file changed, 3 insertions(+), 3 deletions(-)
>>
>> diff --git a/net/ipv6/netfilter/ip6t_NPT.c b/net/ipv6/netfilter/ip6t_NPT.c
>> index 74e171d..61a9b95 100644
>> --- a/net/ipv6/netfilter/ip6t_NPT.c
>> +++ b/net/ipv6/netfilter/ip6t_NPT.c
>> @@ -35,7 +35,7 @@ static int ip6t_npt_checkentry(const struct xt_tgchk_param *par)
>>   	src_sum = csum_partial(&npt->src_pfx.in6, sizeof(npt->src_pfx.in6), 0);
>>   	dst_sum = csum_partial(&npt->dst_pfx.in6, sizeof(npt->dst_pfx.in6), 0);
>>   
>> -	npt->adjustment = csum_fold(csum_sub(src_sum, dst_sum));
>> +	npt->adjustment = ~csum_fold(csum_sub(src_sum, dst_sum));
>>   	return 0;
>>   }
>>   
>> @@ -71,8 +71,8 @@ static bool ip6t_npt_map_pfx(const struct ip6t_npt_tginfo *npt,
>>   			return false;
>>   	}
>>   
>> -	sum = csum_fold(csum_add(csum_unfold((__force __sum16)addr->s6_addr16[idx]),
>> -				 csum_unfold(npt->adjustment)));
>> +	sum = ~csum_fold(csum_add(csum_unfold((__force __sum16)addr->s6_addr16[idx]),
>> +				  csum_unfold(npt->adjustment)));
>>   	if (sum == CSUM_MANGLED_0)
>>   		sum = 0;
>>   	*(__force __sum16 *)&addr->s6_addr16[idx] = sum;
>> -- 
>> 1.7.9.5
>>

--
To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Jean-Michel DILLY - Jan. 31, 2013, 6:45 p.m.
I'll make some tests this week-end. I have had no time theses days.

Regards,
Jean-Michel
Le 31 janv. 2013 à 16:59, Ulrich Weber a écrit :

> From my side, apply yoshofuji patches and my
> onces complement patch, that worked for me ;)
> 
> I can do some more testing tomorrow with different
> addresses and ranges if nobody else finds time...
> 
> Cheers
> Ulrich
> 
> 
> On 01/31/13 11:04, Pablo Neira Ayuso wrote:
>> Hi,
>> 
>> On Tue, Jan 29, 2013 at 03:42:39PM +0100, Ulrich Weber wrote:
>>> Hi Yoshofuji,
>>> 
>>> thanks for your patches! If I add a onces complement
>>> to the return value of csum_fold() it works for my setup.
>> Any consensus on the fix for this? I'd like to have some solution into
>> 3.8-rc.
>> 
>> Thanks.
>> 
>>> On 01/26/13 19:37, YOSHIFUJI Hideaki wrote:
>>>> Cast __wsum from/to __sum16 is wrong.  Instead, apply appropriate
>>>> conversion function: csum_unfold() or csum_fold().
>>>> 
>>>> Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
>>>> ---
>>>>  net/ipv6/netfilter/ip6t_NPT.c |    6 +++---
>>>>  1 file changed, 3 insertions(+), 3 deletions(-)
>>>> 
>>>> diff --git a/net/ipv6/netfilter/ip6t_NPT.c b/net/ipv6/netfilter/ip6t_NPT.c
>>>> index 7302b0b..3ff281b 100644
>>>> --- a/net/ipv6/netfilter/ip6t_NPT.c
>>>> +++ b/net/ipv6/netfilter/ip6t_NPT.c
>>>> @@ -30,7 +30,7 @@ static int ip6t_npt_checkentry(const struct xt_tgchk_param *par)
>>>>  				(__force __wsum)npt->dst_pfx.in6.s6_addr16[i]);
>>>>  	}
>>>>  -	npt->adjustment = (__force __sum16) csum_sub(src_sum, dst_sum);
>>>> +	npt->adjustment = csum_fold(csum_sub(src_sum, dst_sum));
>>>>  	return 0;
>>>>  }
>>>>  @@ -66,8 +66,8 @@ static bool ip6t_npt_map_pfx(const struct ip6t_npt_tginfo *npt,
>>>>  			return false;
>>>>  	}
>>>>  -	sum = (__force __sum16) csum_add((__force __wsum)addr->s6_addr16[idx],
>>>> -			 npt->adjustment);
>>>> +	sum = csum_fold(csum_add(csum_unfold((__force __sum16)addr->s6_addr16[idx]),
>>>> +				 csum_unfold(npt->adjustment)));
>>>>  	if (sum == CSUM_MANGLED_0)
>>>>  		sum = 0;
>>>>  	*(__force __sum16 *)&addr->s6_addr16[idx] = sum;
>>> From 40e0c6d86514a8dcc80f18fbe8a2945c6ee78f6d Mon Sep 17 00:00:00 2001
>>> From: Ulrich Weber <ulrich.weber@sophos.com>
>>> Date: Tue, 29 Jan 2013 15:24:21 +0100
>>> Subject: [PATCH] netfilter: ip6t_NTP: Use onces complement of csum_fold
>>> 
>>> we need a 16bit value but not folded
>>> 
>>> Signed-off-by: Ulrich Weber <ulrich.weber@sophos.com>
>>> ---
>>>  net/ipv6/netfilter/ip6t_NPT.c |    6 +++---
>>>  1 file changed, 3 insertions(+), 3 deletions(-)
>>> 
>>> diff --git a/net/ipv6/netfilter/ip6t_NPT.c b/net/ipv6/netfilter/ip6t_NPT.c
>>> index 74e171d..61a9b95 100644
>>> --- a/net/ipv6/netfilter/ip6t_NPT.c
>>> +++ b/net/ipv6/netfilter/ip6t_NPT.c
>>> @@ -35,7 +35,7 @@ static int ip6t_npt_checkentry(const struct xt_tgchk_param *par)
>>>  	src_sum = csum_partial(&npt->src_pfx.in6, sizeof(npt->src_pfx.in6), 0);
>>>  	dst_sum = csum_partial(&npt->dst_pfx.in6, sizeof(npt->dst_pfx.in6), 0);
>>>  -	npt->adjustment = csum_fold(csum_sub(src_sum, dst_sum));
>>> +	npt->adjustment = ~csum_fold(csum_sub(src_sum, dst_sum));
>>>  	return 0;
>>>  }
>>>  @@ -71,8 +71,8 @@ static bool ip6t_npt_map_pfx(const struct ip6t_npt_tginfo *npt,
>>>  			return false;
>>>  	}
>>>  -	sum = csum_fold(csum_add(csum_unfold((__force __sum16)addr->s6_addr16[idx]),
>>> -				 csum_unfold(npt->adjustment)));
>>> +	sum = ~csum_fold(csum_add(csum_unfold((__force __sum16)addr->s6_addr16[idx]),
>>> +				  csum_unfold(npt->adjustment)));
>>>  	if (sum == CSUM_MANGLED_0)
>>>  		sum = 0;
>>>  	*(__force __sum16 *)&addr->s6_addr16[idx] = sum;
>>> -- 
>>> 1.7.9.5
>>> 
>
Jean-Michel DILLY - Feb. 3, 2013, 10:31 p.m.
Looks good from here. :)

Regards,
JMichel DILLY

Le 31 janv. 2013 à 16:59, Ulrich Weber a écrit :

> From my side, apply yoshofuji patches and my
> onces complement patch, that worked for me ;)
> 
> I can do some more testing tomorrow with different
> addresses and ranges if nobody else finds time...
> 
> Cheers
> Ulrich
> 
> 
> On 01/31/13 11:04, Pablo Neira Ayuso wrote:
>> Hi,
>> 
>> On Tue, Jan 29, 2013 at 03:42:39PM +0100, Ulrich Weber wrote:
>>> Hi Yoshofuji,
>>> 
>>> thanks for your patches! If I add a onces complement
>>> to the return value of csum_fold() it works for my setup.
>> Any consensus on the fix for this? I'd like to have some solution into
>> 3.8-rc.
>> 
>> Thanks.
>> 
>>> On 01/26/13 19:37, YOSHIFUJI Hideaki wrote:
>>>> Cast __wsum from/to __sum16 is wrong.  Instead, apply appropriate
>>>> conversion function: csum_unfold() or csum_fold().
>>>> 
>>>> Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
>>>> ---
>>>>  net/ipv6/netfilter/ip6t_NPT.c |    6 +++---
>>>>  1 file changed, 3 insertions(+), 3 deletions(-)
>>>> 
>>>> diff --git a/net/ipv6/netfilter/ip6t_NPT.c b/net/ipv6/netfilter/ip6t_NPT.c
>>>> index 7302b0b..3ff281b 100644
>>>> --- a/net/ipv6/netfilter/ip6t_NPT.c
>>>> +++ b/net/ipv6/netfilter/ip6t_NPT.c
>>>> @@ -30,7 +30,7 @@ static int ip6t_npt_checkentry(const struct xt_tgchk_param *par)
>>>>  				(__force __wsum)npt->dst_pfx.in6.s6_addr16[i]);
>>>>  	}
>>>>  -	npt->adjustment = (__force __sum16) csum_sub(src_sum, dst_sum);
>>>> +	npt->adjustment = csum_fold(csum_sub(src_sum, dst_sum));
>>>>  	return 0;
>>>>  }
>>>>  @@ -66,8 +66,8 @@ static bool ip6t_npt_map_pfx(const struct ip6t_npt_tginfo *npt,
>>>>  			return false;
>>>>  	}
>>>>  -	sum = (__force __sum16) csum_add((__force __wsum)addr->s6_addr16[idx],
>>>> -			 npt->adjustment);
>>>> +	sum = csum_fold(csum_add(csum_unfold((__force __sum16)addr->s6_addr16[idx]),
>>>> +				 csum_unfold(npt->adjustment)));
>>>>  	if (sum == CSUM_MANGLED_0)
>>>>  		sum = 0;
>>>>  	*(__force __sum16 *)&addr->s6_addr16[idx] = sum;
>>> From 40e0c6d86514a8dcc80f18fbe8a2945c6ee78f6d Mon Sep 17 00:00:00 2001
>>> From: Ulrich Weber <ulrich.weber@sophos.com>
>>> Date: Tue, 29 Jan 2013 15:24:21 +0100
>>> Subject: [PATCH] netfilter: ip6t_NTP: Use onces complement of csum_fold
>>> 
>>> we need a 16bit value but not folded
>>> 
>>> Signed-off-by: Ulrich Weber <ulrich.weber@sophos.com>
>>> ---
>>>  net/ipv6/netfilter/ip6t_NPT.c |    6 +++---
>>>  1 file changed, 3 insertions(+), 3 deletions(-)
>>> 
>>> diff --git a/net/ipv6/netfilter/ip6t_NPT.c b/net/ipv6/netfilter/ip6t_NPT.c
>>> index 74e171d..61a9b95 100644
>>> --- a/net/ipv6/netfilter/ip6t_NPT.c
>>> +++ b/net/ipv6/netfilter/ip6t_NPT.c
>>> @@ -35,7 +35,7 @@ static int ip6t_npt_checkentry(const struct xt_tgchk_param *par)
>>>  	src_sum = csum_partial(&npt->src_pfx.in6, sizeof(npt->src_pfx.in6), 0);
>>>  	dst_sum = csum_partial(&npt->dst_pfx.in6, sizeof(npt->dst_pfx.in6), 0);
>>>  -	npt->adjustment = csum_fold(csum_sub(src_sum, dst_sum));
>>> +	npt->adjustment = ~csum_fold(csum_sub(src_sum, dst_sum));
>>>  	return 0;
>>>  }
>>>  @@ -71,8 +71,8 @@ static bool ip6t_npt_map_pfx(const struct ip6t_npt_tginfo *npt,
>>>  			return false;
>>>  	}
>>>  -	sum = csum_fold(csum_add(csum_unfold((__force __sum16)addr->s6_addr16[idx]),
>>> -				 csum_unfold(npt->adjustment)));
>>> +	sum = ~csum_fold(csum_add(csum_unfold((__force __sum16)addr->s6_addr16[idx]),
>>> +				  csum_unfold(npt->adjustment)));
>>>  	if (sum == CSUM_MANGLED_0)
>>>  		sum = 0;
>>>  	*(__force __sum16 *)&addr->s6_addr16[idx] = sum;
>>> -- 
>>> 1.7.9.5
>>> 
>

Patch

From 40e0c6d86514a8dcc80f18fbe8a2945c6ee78f6d Mon Sep 17 00:00:00 2001
From: Ulrich Weber <ulrich.weber@sophos.com>
Date: Tue, 29 Jan 2013 15:24:21 +0100
Subject: [PATCH] netfilter: ip6t_NTP: Use onces complement of csum_fold

we need a 16bit value but not folded

Signed-off-by: Ulrich Weber <ulrich.weber@sophos.com>
---
 net/ipv6/netfilter/ip6t_NPT.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/net/ipv6/netfilter/ip6t_NPT.c b/net/ipv6/netfilter/ip6t_NPT.c
index 74e171d..61a9b95 100644
--- a/net/ipv6/netfilter/ip6t_NPT.c
+++ b/net/ipv6/netfilter/ip6t_NPT.c
@@ -35,7 +35,7 @@  static int ip6t_npt_checkentry(const struct xt_tgchk_param *par)
 	src_sum = csum_partial(&npt->src_pfx.in6, sizeof(npt->src_pfx.in6), 0);
 	dst_sum = csum_partial(&npt->dst_pfx.in6, sizeof(npt->dst_pfx.in6), 0);
 
-	npt->adjustment = csum_fold(csum_sub(src_sum, dst_sum));
+	npt->adjustment = ~csum_fold(csum_sub(src_sum, dst_sum));
 	return 0;
 }
 
@@ -71,8 +71,8 @@  static bool ip6t_npt_map_pfx(const struct ip6t_npt_tginfo *npt,
 			return false;
 	}
 
-	sum = csum_fold(csum_add(csum_unfold((__force __sum16)addr->s6_addr16[idx]),
-				 csum_unfold(npt->adjustment)));
+	sum = ~csum_fold(csum_add(csum_unfold((__force __sum16)addr->s6_addr16[idx]),
+				  csum_unfold(npt->adjustment)));
 	if (sum == CSUM_MANGLED_0)
 		sum = 0;
 	*(__force __sum16 *)&addr->s6_addr16[idx] = sum;
-- 
1.7.9.5