[IPV6] RAW: Add checksum default defines for MH.

[IPV6] RAW: Add checksum default defines for MH.

[Masahide NAKAMURA]

Add checksum default defines for mobility header(MH) which
goes through raw socket. As the result kernel's behavior is
to handle MH checksum as default.

This patch also removes verifying inbound MH checksum at
mip6_mh_filter() since it did not consider user specified
checksum offset and was redundant check with raw socket code.

Signed-off-by: Masahide NAKAMURA <nakam@linux-ipv6.org>
---
 net/ipv6/mip6.c |   26 --------------------------
 net/ipv6/raw.c  |   13 +++++++++++--
 2 files changed, 11 insertions(+), 28 deletions(-)

diff --git a/net/ipv6/mip6.c b/net/ipv6/mip6.c
index be7dd7d..681bb07 100644
--- a/net/ipv6/mip6.c
+++ b/net/ipv6/mip6.c
@@ -89,7 +89,6 @@ static int mip6_mh_len(int type)
 int mip6_mh_filter(struct sock *sk, struct sk_buff *skb)
 {
 	struct ip6_mh *mh;
-	int mhlen;
 
 	if (!pskb_may_pull(skb, (skb->h.raw - skb->data) + 8) ||
 	    !pskb_may_pull(skb, (skb->h.raw - skb->data) + ((skb->h.raw[1] + 1) << 3)))
@@ -103,31 +102,6 @@ int mip6_mh_filter(struct sock *sk, stru
 		mip6_param_prob(skb, 0, (&mh->ip6mh_hdrlen) - skb->nh.raw);
 		return -1;
 	}
-	mhlen = (mh->ip6mh_hdrlen + 1) << 3;
-
-	if (skb->ip_summed == CHECKSUM_COMPLETE) {
-		skb->ip_summed = CHECKSUM_UNNECESSARY;
-		if (csum_ipv6_magic(&skb->nh.ipv6h->saddr,
-				    &skb->nh.ipv6h->daddr,
-				    mhlen, IPPROTO_MH,
-				    skb->csum)) {
-			LIMIT_NETDEBUG(KERN_DEBUG "mip6: MH hw checksum failed\n");
-			skb->ip_summed = CHECKSUM_NONE;
-		}
-	}
-	if (skb->ip_summed == CHECKSUM_NONE) {
-		if (csum_ipv6_magic(&skb->nh.ipv6h->saddr,
-				    &skb->nh.ipv6h->daddr,
-				    mhlen, IPPROTO_MH,
-				    skb_checksum(skb, 0, mhlen, 0))) {
-			LIMIT_NETDEBUG(KERN_DEBUG "mip6: MH checksum failed "
-				       "[" NIP6_FMT " > " NIP6_FMT "]\n",
-				       NIP6(skb->nh.ipv6h->saddr),
-				       NIP6(skb->nh.ipv6h->daddr));
-			return -1;
-		}
-		skb->ip_summed = CHECKSUM_UNNECESSARY;
-	}
 
 	if (mh->ip6mh_proto != IPPROTO_NONE) {
 		LIMIT_NETDEBUG(KERN_DEBUG "mip6: MH invalid payload proto = %d\n",
diff --git a/net/ipv6/raw.c b/net/ipv6/raw.c
index 4ae1b19..4b83e69 100644
--- a/net/ipv6/raw.c
+++ b/net/ipv6/raw.c
@@ -1094,10 +1094,19 @@ static void rawv6_close(struct sock *sk,
 
 static int rawv6_init_sk(struct sock *sk)
 {
-	if (inet_sk(sk)->num == IPPROTO_ICMPV6) {
-		struct raw6_sock *rp = raw6_sk(sk);
+	struct raw6_sock *rp = raw6_sk(sk);
+
+	switch (inet_sk(sk)->num) {
+	case IPPROTO_ICMPV6:
 		rp->checksum = 1;
 		rp->offset   = 2;
+		break;
+	case IPPROTO_MH:
+		rp->checksum = 1;
+		rp->offset   = 4;
+		break;
+	default:
+		break;
 	}
 	return(0);
 }
-- 
1.4.2

[IPV6] RAW: Add checksum default defines for MH.

[Masahide NAKAMURA]

Add checksum default defines for mobility header(MH) which
goes through raw socket. As the result kernel's behavior is
to handle MH checksum as default.

This patch also removes verifying inbound MH checksum at
mip6_mh_filter() since it did not consider user specified
checksum offset and was redundant check with raw socket code.

Signed-off-by: Masahide NAKAMURA <nakam@linux-ipv6.org>
---
 net/ipv6/mip6.c |   26 --------------------------
 net/ipv6/raw.c  |   13 +++++++++++--
 2 files changed, 11 insertions(+), 28 deletions(-)

diff --git a/net/ipv6/mip6.c b/net/ipv6/mip6.c
index be7dd7d..681bb07 100644
--- a/net/ipv6/mip6.c
+++ b/net/ipv6/mip6.c
@@ -89,7 +89,6 @@ static int mip6_mh_len(int type)
 int mip6_mh_filter(struct sock *sk, struct sk_buff *skb)
 {
 	struct ip6_mh *mh;
-	int mhlen;
 
 	if (!pskb_may_pull(skb, (skb->h.raw - skb->data) + 8) ||
 	    !pskb_may_pull(skb, (skb->h.raw - skb->data) + ((skb->h.raw[1] + 1) << 3)))
@@ -103,31 +102,6 @@ int mip6_mh_filter(struct sock *sk, stru
 		mip6_param_prob(skb, 0, (&mh->ip6mh_hdrlen) - skb->nh.raw);
 		return -1;
 	}
-	mhlen = (mh->ip6mh_hdrlen + 1) << 3;
-
-	if (skb->ip_summed == CHECKSUM_COMPLETE) {
-		skb->ip_summed = CHECKSUM_UNNECESSARY;
-		if (csum_ipv6_magic(&skb->nh.ipv6h->saddr,
-				    &skb->nh.ipv6h->daddr,
-				    mhlen, IPPROTO_MH,
-				    skb->csum)) {
-			LIMIT_NETDEBUG(KERN_DEBUG "mip6: MH hw checksum failed\n");
-			skb->ip_summed = CHECKSUM_NONE;
-		}
-	}
-	if (skb->ip_summed == CHECKSUM_NONE) {
-		if (csum_ipv6_magic(&skb->nh.ipv6h->saddr,
-				    &skb->nh.ipv6h->daddr,
-				    mhlen, IPPROTO_MH,
-				    skb_checksum(skb, 0, mhlen, 0))) {
-			LIMIT_NETDEBUG(KERN_DEBUG "mip6: MH checksum failed "
-				       "[" NIP6_FMT " > " NIP6_FMT "]\n",
-				       NIP6(skb->nh.ipv6h->saddr),
-				       NIP6(skb->nh.ipv6h->daddr));
-			return -1;
-		}
-		skb->ip_summed = CHECKSUM_UNNECESSARY;
-	}
 
 	if (mh->ip6mh_proto != IPPROTO_NONE) {
 		LIMIT_NETDEBUG(KERN_DEBUG "mip6: MH invalid payload proto = %d\n",
diff --git a/net/ipv6/raw.c b/net/ipv6/raw.c
index 4ae1b19..4b83e69 100644
--- a/net/ipv6/raw.c
+++ b/net/ipv6/raw.c
@@ -1094,10 +1094,19 @@ static void rawv6_close(struct sock *sk,
 
 static int rawv6_init_sk(struct sock *sk)
 {
-	if (inet_sk(sk)->num == IPPROTO_ICMPV6) {
-		struct raw6_sock *rp = raw6_sk(sk);
+	struct raw6_sock *rp = raw6_sk(sk);
+
+	switch (inet_sk(sk)->num) {
+	case IPPROTO_ICMPV6:
 		rp->checksum = 1;
 		rp->offset   = 2;
+		break;
+	case IPPROTO_MH:
+		rp->checksum = 1;
+		rp->offset   = 4;
+		break;
+	default:
+		break;
 	}
 	return(0);
 }
-- 
1.4.2

Re: [IPV6] RAW: Add checksum default defines for MH.

[David Miller]

From: Masahide NAKAMURA <nakam@linux-ipv6.org>
Date: Wed,  3 Jan 2007 18:32:22 +0900

> Add checksum default defines for mobility header(MH) which
> goes through raw socket. As the result kernel's behavior is
> to handle MH checksum as default.
> 
> This patch also removes verifying inbound MH checksum at
> mip6_mh_filter() since it did not consider user specified
> checksum offset and was redundant check with raw socket code.
> 
> Signed-off-by: Masahide NAKAMURA <nakam@linux-ipv6.org>

Did a complete agreement occur that this patch is ok?

Thank you.

Re: [IPV6] RAW: Add checksum default defines for MH.

[Herbert Xu]

David Miller <davem@davemloft.net> wrote:
>
> Did a complete agreement occur that this patch is ok?

My only concern is that we're putting an arbitrary list of
protocols in the generic raw.c.  What's the justification
for including these protocols in particular but not others?

Is there any reason why the application can't just use the
existing IPV6_CHECKSUM socket option to set the same fields?

Cheers,
-- 
Visit Openswan at http://www.openswan.org/
Email: Herbert Xu ~{PmV>HI~} <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt

Re: [IPV6] RAW: Add checksum default defines for MH.

[David Miller]

From: Herbert Xu <herbert@gondor.apana.org.au>
Date: Wed, 24 Jan 2007 17:56:23 +1100

> David Miller <davem@davemloft.net> wrote:
> >
> > Did a complete agreement occur that this patch is ok?
> 
> My only concern is that we're putting an arbitrary list of
> protocols in the generic raw.c.  What's the justification
> for including these protocols in particular but not others?
> 
> Is there any reason why the application can't just use the
> existing IPV6_CHECKSUM socket option to set the same fields?

My understanding in the MH case is that the kernel is going
to make changes to the header that the user can't predict
and thus it's impossible for them to set the correct checksum.

I don't know what the justification is for ICMP6 though :-)

Re: [IPV6] RAW: Add checksum default defines for MH.

[YOSHIFUJI Hideaki / 吉藤英明]

In article <E1H9c3T-0005HA-00@gondolin.me.apana.org.au> (at Wed, 24 Jan 2007 17:56:23 +1100), Herbert Xu <herbert@gondor.apana.org.au> says:

> David Miller <davem@davemloft.net> wrote:
> >
> > Did a complete agreement occur that this patch is ok?
> 
> My only concern is that we're putting an arbitrary list of
> protocols in the generic raw.c.  What's the justification
> for including these protocols in particular but not others?
> 
> Is there any reason why the application can't just use the
> existing IPV6_CHECKSUM socket option to set the same fields?

Yes, it can.

The only reason they (not myself :-)) want to put this in is
because the RFC says that MIP6 implementation MUST compute
checksum by default when it passes the MH to userspace.  On
the other hand, it also states that user space application SHOULD
set IPV6_CHECKSUM to 4.

--yoshfuji

Re: [IPV6] RAW: Add checksum default defines for MH.

[Herbert Xu]

On Wed, Jan 24, 2007 at 04:05:41PM +0900, YOSHIFUJI Hideaki / ?$B5HF#1QL@ wrote:
> 
> The only reason they (not myself :-)) want to put this in is
> because the RFC says that MIP6 implementation MUST compute
> checksum by default when it passes the MH to userspace.  On
> the other hand, it also states that user space application SHOULD
> set IPV6_CHECKSUM to 4.

OK if the RFC says so then it's fine by me :)
-- 
Visit Openswan at http://www.openswan.org/
Email: Herbert Xu ~{PmV>HI~} <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt

Re: [IPV6] RAW: Add checksum default defines for MH.

[Masahide NAKAMURA]

David Miller wrote:
> From: Herbert Xu <herbert@gondor.apana.org.au>
> Date: Wed, 24 Jan 2007 17:56:23 +1100
> 
>> David Miller <davem@davemloft.net> wrote:
>>> Did a complete agreement occur that this patch is ok?
>> My only concern is that we're putting an arbitrary list of
>> protocols in the generic raw.c.  What's the justification
>> for including these protocols in particular but not others?
>>
>> Is there any reason why the application can't just use the
>> existing IPV6_CHECKSUM socket option to set the same fields?
> 
> My understanding in the MH case is that the kernel is going
> to make changes to the header that the user can't predict
> and thus it's impossible for them to set the correct checksum.

Yes, kernel will change the IPv6 header address, however,
actually it is possible to compute MH checksum by user-space
since final address (=home address) is seen by application
on both sending and receiving case and the checksum is calculated
by the address. It is true user can use IPV6_CHECKSUM option
to set the same fields.
(FYI, it is failed to validate MH checksum with IPv6 header
address on wire (or before parsing extension headers) for such
Mobile IPv6 routing optimized packet).

So this fix is not mandatory feature for kernel.
This patch just relaxes user application like ICMPv6 case
then we can cancel this if it is too much.

Thanks for taking care of this again, guys.

-- 
Masahide NAKAMURA

Re: [IPV6] RAW: Add checksum default defines for MH.

[YOSHIFUJI Hideaki / 吉藤英明]

Dave,

AFAIK, we have not heard objectsions and I finally agree on this.
Please apply.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>

--yoshfuji

In article <11678182681435-git-send-email-nakam@linux-ipv6.org> (at Wed,  3 Jan 2007 18:57:48 +0900), Masahide NAKAMURA <nakam@linux-ipv6.org> says:

> Add checksum default defines for mobility header(MH) which
> goes through raw socket. As the result kernel's behavior is
> to handle MH checksum as default.
> 
> This patch also removes verifying inbound MH checksum at
> mip6_mh_filter() since it did not consider user specified
> checksum offset and was redundant check with raw socket code.
> 
> Signed-off-by: Masahide NAKAMURA <nakam@linux-ipv6.org>
> ---
>  net/ipv6/mip6.c |   26 --------------------------
>  net/ipv6/raw.c  |   13 +++++++++++--
>  2 files changed, 11 insertions(+), 28 deletions(-)
> 
> diff --git a/net/ipv6/mip6.c b/net/ipv6/mip6.c
> index be7dd7d..681bb07 100644
> --- a/net/ipv6/mip6.c
> +++ b/net/ipv6/mip6.c
> @@ -89,7 +89,6 @@ static int mip6_mh_len(int type)
>  int mip6_mh_filter(struct sock *sk, struct sk_buff *skb)
>  {
>  	struct ip6_mh *mh;
> -	int mhlen;
>  
>  	if (!pskb_may_pull(skb, (skb->h.raw - skb->data) + 8) ||
>  	    !pskb_may_pull(skb, (skb->h.raw - skb->data) + ((skb->h.raw[1] + 1) << 3)))
> @@ -103,31 +102,6 @@ int mip6_mh_filter(struct sock *sk, stru
>  		mip6_param_prob(skb, 0, (&mh->ip6mh_hdrlen) - skb->nh.raw);
>  		return -1;
>  	}
> -	mhlen = (mh->ip6mh_hdrlen + 1) << 3;
> -
> -	if (skb->ip_summed == CHECKSUM_COMPLETE) {
> -		skb->ip_summed = CHECKSUM_UNNECESSARY;
> -		if (csum_ipv6_magic(&skb->nh.ipv6h->saddr,
> -				    &skb->nh.ipv6h->daddr,
> -				    mhlen, IPPROTO_MH,
> -				    skb->csum)) {
> -			LIMIT_NETDEBUG(KERN_DEBUG "mip6: MH hw checksum failed\n");
> -			skb->ip_summed = CHECKSUM_NONE;
> -		}
> -	}
> -	if (skb->ip_summed == CHECKSUM_NONE) {
> -		if (csum_ipv6_magic(&skb->nh.ipv6h->saddr,
> -				    &skb->nh.ipv6h->daddr,
> -				    mhlen, IPPROTO_MH,
> -				    skb_checksum(skb, 0, mhlen, 0))) {
> -			LIMIT_NETDEBUG(KERN_DEBUG "mip6: MH checksum failed "
> -				       "[" NIP6_FMT " > " NIP6_FMT "]\n",
> -				       NIP6(skb->nh.ipv6h->saddr),
> -				       NIP6(skb->nh.ipv6h->daddr));
> -			return -1;
> -		}
> -		skb->ip_summed = CHECKSUM_UNNECESSARY;
> -	}
>  
>  	if (mh->ip6mh_proto != IPPROTO_NONE) {
>  		LIMIT_NETDEBUG(KERN_DEBUG "mip6: MH invalid payload proto = %d\n",
> diff --git a/net/ipv6/raw.c b/net/ipv6/raw.c
> index 4ae1b19..4b83e69 100644
> --- a/net/ipv6/raw.c
> +++ b/net/ipv6/raw.c
> @@ -1094,10 +1094,19 @@ static void rawv6_close(struct sock *sk,
>  
>  static int rawv6_init_sk(struct sock *sk)
>  {
> -	if (inet_sk(sk)->num == IPPROTO_ICMPV6) {
> -		struct raw6_sock *rp = raw6_sk(sk);
> +	struct raw6_sock *rp = raw6_sk(sk);
> +
> +	switch (inet_sk(sk)->num) {
> +	case IPPROTO_ICMPV6:
>  		rp->checksum = 1;
>  		rp->offset   = 2;
> +		break;
> +	case IPPROTO_MH:
> +		rp->checksum = 1;
> +		rp->offset   = 4;
> +		break;
> +	default:
> +		break;
>  	}
>  	return(0);
>  }
> -- 
> 1.4.2
> 
> -
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Re: [IPV6] RAW: Add checksum default defines for MH.

[David Miller]

From: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Date: Wed, 07 Feb 2007 15:43:34 +0900 (JST)

> AFAIK, we have not heard objectsions and I finally agree on this.
> Please apply.
> 
> Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>

Yes, thank you for reminding me, I will apply this to
net-2.6.21 right now.