[RFC PATCH] xfrm: Accept XFRM_STATE_AF_UNSPEC SAs on IPv4/IPv6 only hosts

[RFC PATCH] xfrm: Accept XFRM_STATE_AF_UNSPEC SAs on IPv4/IPv6 only hosts

[Martin Willi]

Installing SAs using the XFRM_STATE_AF_UNSPEC fails on hosts with
support for one address family only. This patch accepts such SAs, even
if the processing of not supported packets will fail.

Signed-off-by: Martin Willi <martin@strongswan.org>

---
For me the meaning of that flag is not really clear. If it means
"I-want-to-run-v6-in-v4-or-vice-versa" then the current behavior
(reject SA) is probably ok.
However, in my understanding ("accept-any-inner-address-family"), the
kernel should accept such SAs. Otherwise userspace has to query the
supported address families.

diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index 508337f..456782b 100644
--- a/net/xfrm/xfrm_state.c
+++ b/net/xfrm/xfrm_state.c
@@ -2032,8 +2032,9 @@ int xfrm_init_state(struct xfrm_state *x)
 		x->inner_mode = inner_mode;
 	} else {
 		struct xfrm_mode *inner_mode_iaf;
+		int iafamily = AF_INET;
 
-		inner_mode = xfrm_get_mode(x->props.mode, AF_INET);
+		inner_mode = xfrm_get_mode(x->props.mode, x->props.family);
 		if (inner_mode == NULL)
 			goto error;
 
@@ -2041,22 +2042,17 @@ int xfrm_init_state(struct xfrm_state *x)
 			xfrm_put_mode(inner_mode);
 			goto error;
 		}
+		x->inner_mode = inner_mode;
 
-		inner_mode_iaf = xfrm_get_mode(x->props.mode, AF_INET6);
-		if (inner_mode_iaf == NULL)
-			goto error;
+		if (x->props.family == AF_INET)
+			iafamily = AF_INET6;
 
-		if (!(inner_mode_iaf->flags & XFRM_MODE_FLAG_TUNNEL)) {
-			xfrm_put_mode(inner_mode_iaf);
-			goto error;
-		}
-
-		if (x->props.family == AF_INET) {
-			x->inner_mode = inner_mode;
-			x->inner_mode_iaf = inner_mode_iaf;
-		} else {
-			x->inner_mode = inner_mode_iaf;
-			x->inner_mode_iaf = inner_mode;
+		inner_mode_iaf = xfrm_get_mode(x->props.mode, iafamily);
+		if (inner_mode_iaf) {
+			if (inner_mode_iaf->flags & XFRM_MODE_FLAG_TUNNEL)
+				x->inner_mode_iaf = inner_mode_iaf;
+			else
+				xfrm_put_mode(inner_mode_iaf);
 		}
 	}
 

Re: [RFC PATCH] xfrm: Accept XFRM_STATE_AF_UNSPEC SAs on IPv4/IPv6 only hosts

[Martin Willi]

I'm wondering what's the state of this patch. Should I resubmit without
[RFC]? Something else wrong with it?

It has been tagged as "Accepted" in patchworks, but isn't gone anywhere
so far.

Thanks
Martin

On Tue, 2008-11-25 at 17:10 +0100, Martin Willi wrote:
> Installing SAs using the XFRM_STATE_AF_UNSPEC fails on hosts with
> support for one address family only. This patch accepts such SAs, even
> if the processing of not supported packets will fail.
> 
> Signed-off-by: Martin Willi <martin@strongswan.org>
> 
> ---
> For me the meaning of that flag is not really clear. If it means
> "I-want-to-run-v6-in-v4-or-vice-versa" then the current behavior
> (reject SA) is probably ok.
> However, in my understanding ("accept-any-inner-address-family"), the
> kernel should accept such SAs. Otherwise userspace has to query the
> supported address families.
> 
> diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
> index 508337f..456782b 100644
> --- a/net/xfrm/xfrm_state.c
> +++ b/net/xfrm/xfrm_state.c
> @@ -2032,8 +2032,9 @@ int xfrm_init_state(struct xfrm_state *x)
>  		x->inner_mode = inner_mode;
>  	} else {
>  		struct xfrm_mode *inner_mode_iaf;
> +		int iafamily = AF_INET;
>  
> -		inner_mode = xfrm_get_mode(x->props.mode, AF_INET);
> +		inner_mode = xfrm_get_mode(x->props.mode, x->props.family);
>  		if (inner_mode == NULL)
>  			goto error;
>  
> @@ -2041,22 +2042,17 @@ int xfrm_init_state(struct xfrm_state *x)
>  			xfrm_put_mode(inner_mode);
>  			goto error;
>  		}
> +		x->inner_mode = inner_mode;
>  
> -		inner_mode_iaf = xfrm_get_mode(x->props.mode, AF_INET6);
> -		if (inner_mode_iaf == NULL)
> -			goto error;
> +		if (x->props.family == AF_INET)
> +			iafamily = AF_INET6;
>  
> -		if (!(inner_mode_iaf->flags & XFRM_MODE_FLAG_TUNNEL)) {
> -			xfrm_put_mode(inner_mode_iaf);
> -			goto error;
> -		}
> -
> -		if (x->props.family == AF_INET) {
> -			x->inner_mode = inner_mode;
> -			x->inner_mode_iaf = inner_mode_iaf;
> -		} else {
> -			x->inner_mode = inner_mode_iaf;
> -			x->inner_mode_iaf = inner_mode;
> +		inner_mode_iaf = xfrm_get_mode(x->props.mode, iafamily);
> +		if (inner_mode_iaf) {
> +			if (inner_mode_iaf->flags & XFRM_MODE_FLAG_TUNNEL)
> +				x->inner_mode_iaf = inner_mode_iaf;
> +			else
> +				xfrm_put_mode(inner_mode_iaf);
>  		}
>  	}
>  
> 
> 
> --
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Re: [RFC PATCH] xfrm: Accept XFRM_STATE_AF_UNSPEC SAs on IPv4/IPv6 only hosts

[David Miller]

From: Martin Willi <martin@strongswan.org>
Date: Tue, 02 Dec 2008 10:49:24 +0100

> I'm wondering what's the state of this patch. Should I resubmit without
> [RFC]? Something else wrong with it?
> 
> It has been tagged as "Accepted" in patchworks, but isn't gone anywhere
> so far.

Sorry, I accidently advanced the state, it should still be in
"under review".  Let me fix that.

I want to do some research before I apply this patch, so please
be patient.

Thanks!

Re: [RFC PATCH] xfrm: Accept XFRM_STATE_AF_UNSPEC SAs on IPv4/IPv6 only hosts

[David Miller]

From: Martin Willi <martin@strongswan.org>
Date: Tue, 25 Nov 2008 17:10:06 +0100

> Installing SAs using the XFRM_STATE_AF_UNSPEC fails on hosts with
> support for one address family only. This patch accepts such SAs, even
> if the processing of not supported packets will fail.
> 
> Signed-off-by: Martin Willi <martin@strongswan.org>
> 
> ---
> For me the meaning of that flag is not really clear. If it means
> "I-want-to-run-v6-in-v4-or-vice-versa" then the current behavior
> (reject SA) is probably ok.
> However, in my understanding ("accept-any-inner-address-family"), the
> kernel should accept such SAs. Otherwise userspace has to query the
> supported address families.

Ok, your interpretation works for me, I've applied this to
net-next-2.6, thanks.