[PATCH] ipv4: fix ipsec forward performance regression

[PATCH] ipv4: fix ipsec forward performance regression

[Yan, Zheng]

There is bug in commit 5e2b61f(ipv4: Remove flowi from struct rtable).
It makes xfrm4_fill_dst() modify wrong data structure.

Signed-off-by: Zheng Yan <zheng.z.yan@intel.com>
---
 net/ipv4/xfrm4_policy.c |   14 +++++++-------
 1 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/net/ipv4/xfrm4_policy.c b/net/ipv4/xfrm4_policy.c
index fc5368a..a0b4c5d 100644
--- a/net/ipv4/xfrm4_policy.c
+++ b/net/ipv4/xfrm4_policy.c
@@ -79,13 +79,13 @@ static int xfrm4_fill_dst(struct xfrm_dst *xdst, struct net_device *dev,
 	struct rtable *rt = (struct rtable *)xdst->route;
 	const struct flowi4 *fl4 = &fl->u.ip4;
 
-	rt->rt_key_dst = fl4->daddr;
-	rt->rt_key_src = fl4->saddr;
-	rt->rt_key_tos = fl4->flowi4_tos;
-	rt->rt_route_iif = fl4->flowi4_iif;
-	rt->rt_iif = fl4->flowi4_iif;
-	rt->rt_oif = fl4->flowi4_oif;
-	rt->rt_mark = fl4->flowi4_mark;
+	xdst->u.rt.rt_key_dst = fl4->daddr;
+	xdst->u.rt.rt_key_src = fl4->saddr;
+	xdst->u.rt.rt_key_tos = fl4->flowi4_tos;
+	xdst->u.rt.rt_route_iif = fl4->flowi4_iif;
+	xdst->u.rt.rt_iif = fl4->flowi4_iif;
+	xdst->u.rt.rt_oif = fl4->flowi4_oif;
+	xdst->u.rt.rt_mark = fl4->flowi4_mark;
 
 	xdst->u.dst.dev = dev;
 	dev_hold(dev);
-- 
1.7.4.4

Re: [PATCH] ipv4: fix ipsec forward performance regression

[Eric Dumazet]

Le dimanche 23 octobre 2011 à 15:58 +0800, Yan, Zheng a écrit :
> There is bug in commit 5e2b61f(ipv4: Remove flowi from struct rtable).
> It makes xfrm4_fill_dst() modify wrong data structure.
> 
> Signed-off-by: Zheng Yan <zheng.z.yan@intel.com>
> ---
>  net/ipv4/xfrm4_policy.c |   14 +++++++-------
>  1 files changed, 7 insertions(+), 7 deletions(-)
> 
> diff --git a/net/ipv4/xfrm4_policy.c b/net/ipv4/xfrm4_policy.c
> index fc5368a..a0b4c5d 100644
> --- a/net/ipv4/xfrm4_policy.c
> +++ b/net/ipv4/xfrm4_policy.c
> @@ -79,13 +79,13 @@ static int xfrm4_fill_dst(struct xfrm_dst *xdst, struct net_device *dev,
>  	struct rtable *rt = (struct rtable *)xdst->route;
>  	const struct flowi4 *fl4 = &fl->u.ip4;
>  
> -	rt->rt_key_dst = fl4->daddr;
> -	rt->rt_key_src = fl4->saddr;
> -	rt->rt_key_tos = fl4->flowi4_tos;
> -	rt->rt_route_iif = fl4->flowi4_iif;
> -	rt->rt_iif = fl4->flowi4_iif;
> -	rt->rt_oif = fl4->flowi4_oif;
> -	rt->rt_mark = fl4->flowi4_mark;
> +	xdst->u.rt.rt_key_dst = fl4->daddr;
> +	xdst->u.rt.rt_key_src = fl4->saddr;
> +	xdst->u.rt.rt_key_tos = fl4->flowi4_tos;
> +	xdst->u.rt.rt_route_iif = fl4->flowi4_iif;
> +	xdst->u.rt.rt_iif = fl4->flowi4_iif;
> +	xdst->u.rt.rt_oif = fl4->flowi4_oif;
> +	xdst->u.rt.rt_mark = fl4->flowi4_mark;
>  
>  	xdst->u.dst.dev = dev;
>  	dev_hold(dev);

Good catch, thanks !

Reported-by: Kim Phillips <kim.phillips@freescale.com>

Acked-by: Eric Dumazet <eric.dumazet@gmail.com>

Re: [PATCH] ipv4: fix ipsec forward performance regression

[Julian Anastasov]

	Hello,

On Sun, 23 Oct 2011, Yan, Zheng wrote:

> There is bug in commit 5e2b61f(ipv4: Remove flowi from struct rtable).
> It makes xfrm4_fill_dst() modify wrong data structure.
> 
> Signed-off-by: Zheng Yan <zheng.z.yan@intel.com>
> ---
>  net/ipv4/xfrm4_policy.c |   14 +++++++-------
>  1 files changed, 7 insertions(+), 7 deletions(-)
> 
> diff --git a/net/ipv4/xfrm4_policy.c b/net/ipv4/xfrm4_policy.c
> index fc5368a..a0b4c5d 100644
> --- a/net/ipv4/xfrm4_policy.c
> +++ b/net/ipv4/xfrm4_policy.c
> @@ -79,13 +79,13 @@ static int xfrm4_fill_dst(struct xfrm_dst *xdst, struct net_device *dev,
>  	struct rtable *rt = (struct rtable *)xdst->route;
>  	const struct flowi4 *fl4 = &fl->u.ip4;
>  
> -	rt->rt_key_dst = fl4->daddr;
> -	rt->rt_key_src = fl4->saddr;
> -	rt->rt_key_tos = fl4->flowi4_tos;
> -	rt->rt_route_iif = fl4->flowi4_iif;
> -	rt->rt_iif = fl4->flowi4_iif;
> -	rt->rt_oif = fl4->flowi4_oif;
> -	rt->rt_mark = fl4->flowi4_mark;
> +	xdst->u.rt.rt_key_dst = fl4->daddr;
> +	xdst->u.rt.rt_key_src = fl4->saddr;
> +	xdst->u.rt.rt_key_tos = fl4->flowi4_tos;
> +	xdst->u.rt.rt_route_iif = fl4->flowi4_iif;

	May be I'm missing something but I don't see where
flowi4_iif is set for the forwarding case. __xfrm_route_forward
calls xfrm_decode_session which does not appear to set
flowi4_iif. When providing fl4 for output routes flowi4_iif
is always set to 0, so it represents rt_route_iif. But
then there are 2 variants for __ip_route_output_key:

- ip_route_output_slow sets flowi4_iif to loopback and
flowi4_oif to outdev during lookup but never restores them
to original values. It is assumed that caller uses outdev
from dst, not from flowi4_oif.

- for cached route we do not update flowi4_iif and flowi4_oif
in __ip_route_output_key, so the resulting fl4 can not be
used for these values. I assume, the current rules are that
only fl4.saddr and daddr are updated while flowi4_iif and
flowi4_oif are not. It looks wrong flowi code to rely on them.

	Currently, we have 3 values for devices:

rt_iif: indev for input routes, resulting outdev for output routes
which plays the role as indev for loopback traffic.

rt_oif: original outdev key, 0 for input routes, can be 0 for
output routes if socket is not bound to oif

rt_route_iif: indev for input routes, 0 for output routes

	With above rules for flowi4_iif and flowi4_oif
it is impossible to select value for rt_iif from fl4.

	I don't know the xfrm code well, may be after the
mentioned change we damaged rt_oif and rt_route_iif values
for cached dst which can lead to using slow path all the time.
Even if rt_intern_hash() avoids caching similar dsts multiple
times, if cached entry is damaged we will add more and
more new entries after every damage.

> +	xdst->u.rt.rt_iif = fl4->flowi4_iif;
> +	xdst->u.rt.rt_oif = fl4->flowi4_oif;
> +	xdst->u.rt.rt_mark = fl4->flowi4_mark;
>  
>  	xdst->u.dst.dev = dev;
>  	dev_hold(dev);

Regards

--
Julian Anastasov <ja@ssi.bg>

Re: [PATCH] ipv4: fix ipsec forward performance regression

[Yan, Zheng]

On 10/23/2011 10:52 PM, Julian Anastasov wrote:
> 
> 	Hello,
> 
> On Sun, 23 Oct 2011, Yan, Zheng wrote:
> 
>> There is bug in commit 5e2b61f(ipv4: Remove flowi from struct rtable).
>> It makes xfrm4_fill_dst() modify wrong data structure.
>>
>> Signed-off-by: Zheng Yan <zheng.z.yan@intel.com>
>> ---
>>  net/ipv4/xfrm4_policy.c |   14 +++++++-------
>>  1 files changed, 7 insertions(+), 7 deletions(-)
>>
>> diff --git a/net/ipv4/xfrm4_policy.c b/net/ipv4/xfrm4_policy.c
>> index fc5368a..a0b4c5d 100644
>> --- a/net/ipv4/xfrm4_policy.c
>> +++ b/net/ipv4/xfrm4_policy.c
>> @@ -79,13 +79,13 @@ static int xfrm4_fill_dst(struct xfrm_dst *xdst, struct net_device *dev,
>>  	struct rtable *rt = (struct rtable *)xdst->route;
>>  	const struct flowi4 *fl4 = &fl->u.ip4;
>>  
>> -	rt->rt_key_dst = fl4->daddr;
>> -	rt->rt_key_src = fl4->saddr;
>> -	rt->rt_key_tos = fl4->flowi4_tos;
>> -	rt->rt_route_iif = fl4->flowi4_iif;
>> -	rt->rt_iif = fl4->flowi4_iif;
>> -	rt->rt_oif = fl4->flowi4_oif;
>> -	rt->rt_mark = fl4->flowi4_mark;
>> +	xdst->u.rt.rt_key_dst = fl4->daddr;
>> +	xdst->u.rt.rt_key_src = fl4->saddr;
>> +	xdst->u.rt.rt_key_tos = fl4->flowi4_tos;
>> +	xdst->u.rt.rt_route_iif = fl4->flowi4_iif;
> 
> 	May be I'm missing something but I don't see where
> flowi4_iif is set for the forwarding case. __xfrm_route_forward
> calls xfrm_decode_session which does not appear to set
> flowi4_iif. When providing fl4 for output routes flowi4_iif
> is always set to 0, so it represents rt_route_iif. But
> then there are 2 variants for __ip_route_output_key:
> 
> - ip_route_output_slow sets flowi4_iif to loopback and
> flowi4_oif to outdev during lookup but never restores them
> to original values. It is assumed that caller uses outdev
> from dst, not from flowi4_oif.
> 
> - for cached route we do not update flowi4_iif and flowi4_oif
> in __ip_route_output_key, so the resulting fl4 can not be
> used for these values. I assume, the current rules are that
> only fl4.saddr and daddr are updated while flowi4_iif and
> flowi4_oif are not. It looks wrong flowi code to rely on them.
> 
> 	Currently, we have 3 values for devices:
> 
> rt_iif: indev for input routes, resulting outdev for output routes
> which plays the role as indev for loopback traffic.
> 
> rt_oif: original outdev key, 0 for input routes, can be 0 for
> output routes if socket is not bound to oif
> 
> rt_route_iif: indev for input routes, 0 for output routes
> 
> 	With above rules for flowi4_iif and flowi4_oif
> it is impossible to select value for rt_iif from fl4.
> 
> 	I don't know the xfrm code well, may be after the

Neither do I. My understanding is that xfrm_dst(s) are managed by the
flow cache (net/core/flow.c). We don't put them into the routing cache.

Regards
Yan, Zheng 

> mentioned change we damaged rt_oif and rt_route_iif values
> for cached dst which can lead to using slow path all the time.
> Even if rt_intern_hash() avoids caching similar dsts multiple
> times, if cached entry is damaged we will add more and
> more new entries after every damage.
> 
>> +	xdst->u.rt.rt_iif = fl4->flowi4_iif;
>> +	xdst->u.rt.rt_oif = fl4->flowi4_oif;
>> +	xdst->u.rt.rt_mark = fl4->flowi4_mark;
>>  
>>  	xdst->u.dst.dev = dev;
>>  	dev_hold(dev);
> 
> Regards
> 
> --
> Julian Anastasov <ja@ssi.bg>

Re: [PATCH] ipv4: fix ipsec forward performance regression

[David Miller]

From: "Yan, Zheng" <zheng.z.yan@intel.com>
Date: Mon, 24 Oct 2011 08:41:53 +0800

> My understanding is that xfrm_dst(s) are managed by the flow cache
> (net/core/flow.c). We don't put them into the routing cache.

This is correct.

Re: [PATCH] ipv4: fix ipsec forward performance regression

[David Miller]

From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Sun, 23 Oct 2011 11:03:10 +0200

> Le dimanche 23 octobre 2011 à 15:58 +0800, Yan, Zheng a écrit :
>> There is bug in commit 5e2b61f(ipv4: Remove flowi from struct rtable).
>> It makes xfrm4_fill_dst() modify wrong data structure.
>> 
>> Signed-off-by: Zheng Yan <zheng.z.yan@intel.com>
 ...
> Reported-by: Kim Phillips <kim.phillips@freescale.com>
> 
> Acked-by: Eric Dumazet <eric.dumazet@gmail.com>

Applied, thanks everyone.

Re: [PATCH] ipv4: fix ipsec forward performance regression

[Kim Phillips]

On Mon, 24 Oct 2011 03:02:03 -0400
David Miller <davem@davemloft.net> wrote:

> From: Eric Dumazet <eric.dumazet@gmail.com>
> Date: Sun, 23 Oct 2011 11:03:10 +0200
> 
> > Le dimanche 23 octobre 2011 à 15:58 +0800, Yan, Zheng a écrit :
> >> There is bug in commit 5e2b61f(ipv4: Remove flowi from struct rtable).
> >> It makes xfrm4_fill_dst() modify wrong data structure.
> >> 
> >> Signed-off-by: Zheng Yan <zheng.z.yan@intel.com>
>  ...
> > Reported-by: Kim Phillips <kim.phillips@freescale.com>
> > 
> > Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
> 
> Applied, thanks everyone.

To: <stable@kernel.org>

-stable maintainers, please consider the following two upstream
commits for inclusion in upcoming v3.0.x [1] stable releases:

v3.0.8 plus this:

upstream commit b73233960a59ee66e09d642f13d0592b13651e94
(ipv4: fix ipsec forward performance regression)

increases IPSec fwding performance from 0.2kpps to ~3.5kpps.

Adding this:

upstream commit aa1c366e4febc7f5c2b84958a2dd7cd70e28f9d0
(net: Handle different key sizes between address families in flow
cache)

to that, brings it back up to 2.6.38 levels, i.e., ~44kpps.

note that for v2.6.39.4 (.39 is the first kernel version with the
40->0.2kpps regression), commit b732339 depends on a slew of
commits, presumably ending with commit 5e2b61f: ipv4: Remove flowi
from struct rtable.

However it appears commit aa1c366e alone will restore almost all
the performance (~42kpps) on that kernel version.

So to summarize, please cherry-pick:

v2.6.39.x: aa1c366: net: Handle different key sizes between address families in flow cache
v3.0.x: aa1c366: net: Handle different key sizes between address families in flow cache
v3.0.x: b732339: ipv4: fix ipsec forward performance regression
v3.1.x: b732339: ipv4: fix ipsec forward performance regression

[All figures are based on a p2020ds board configured to rx, encrypt
and forward 64-byte packets.]

Thanks,

Kim

[1] initial kernel in long-term stable series for the embedded
industry (http://lwn.net/Articles/464834/)

Re: [PATCH] ipv4: fix ipsec forward performance regression

[David Miller]

From: Kim Phillips <kim.phillips@freescale.com>
Date: Tue, 1 Nov 2011 18:50:22 -0500

> -stable maintainers, please consider the following two upstream
> commits for inclusion in upcoming v3.0.x [1] stable releases:

I submit networking stable fixes as needed, so please make such
requests to me.

I haven't submitted this change yet because I want it to sit a bit
longer in Linus's tree to make sure there aren't any unwanted
side-effects.

Re: [PATCH] ipv4: fix ipsec forward performance regression

[Kim Phillips]

On Tue, 1 Nov 2011 20:34:30 -0400
David Miller <davem@davemloft.net> wrote:

> From: Kim Phillips <kim.phillips@freescale.com>
> Date: Tue, 1 Nov 2011 18:50:22 -0500
> 
> > -stable maintainers, please consider the following two upstream
> > commits for inclusion in upcoming v3.0.x [1] stable releases:
> 
> I submit networking stable fixes as needed, so please make such
> requests to me.
> 
> I haven't submitted this change yet because I want it to sit a bit
> longer in Linus's tree to make sure there aren't any unwanted
> side-effects.

I see b732339 (ipv4: fix ipsec forward performance regression) has
been added to the 3.0- and 3.1-stable trees.

b732339 increases IPSec fwding performance from 0.2kpps to ~3.5kpps.

However, adding upstream commit aa1c366 (net: Handle different key
sizes between address families in flow cache) brings performance
back up to 2.6.38 levels, i.e., ~44kpps.

So can aa1c366 also be queued to the v2.6.39 and v3.0 stable
trees?

Thanks,

Kim

Re: [PATCH] ipv4: fix ipsec forward performance regression

[David Miller]

From: Kim Phillips <kim.phillips@freescale.com>
Date: Thu, 3 Nov 2011 13:58:51 -0500

> I see b732339 (ipv4: fix ipsec forward performance regression) has
> been added to the 3.0- and 3.1-stable trees.
> 
> b732339 increases IPSec fwding performance from 0.2kpps to ~3.5kpps.
> 
> However, adding upstream commit aa1c366 (net: Handle different key
> sizes between address families in flow cache) brings performance
> back up to 2.6.38 levels, i.e., ~44kpps.
> 
> So can aa1c366 also be queued to the v2.6.39 and v3.0 stable
> trees?

1) stable@kernel.org no longer exists and will just go into the bit
   bucket, it's now stable@vger.kernel.org

2) The patch in question doesn't apply cleanly to v3.0.8 -stable so
   if it's important to you you'll need to submit a backport.

3) 2.6.39 is no longer a maintained -stable kernel series.

[stable] net: Handle different key sizes between address families in flow cache

[Kim Phillips]

commit aa1c366e4febc7f5c2b84958a2dd7cd70e28f9d0 upstream.

With the conversion of struct flowi to a union of AF-specific structs, some
operations on the flow cache need to account for the exact size of the key.

Signed-off-by: David Ward <david.ward@ll.mit.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>
Cc: stable@vger.kernel.org # v3.0.x
---
This patch is the result of a clean cherry-pick onto v3.0.8.
It restores IPSec fwding performance from ~4kpps back to ~44kpps on
a P2020DS board.

 include/net/flow.h |   19 +++++++++++++++++++
 net/core/flow.c    |   31 +++++++++++++++++--------------
 2 files changed, 36 insertions(+), 14 deletions(-)

diff --git a/include/net/flow.h b/include/net/flow.h
index c6d5fe5..93a8785 100644
--- a/include/net/flow.h
+++ b/include/net/flow.h
@@ -7,6 +7,7 @@
 #ifndef _NET_FLOW_H
 #define _NET_FLOW_H
 
+#include <linux/socket.h>
 #include <linux/in6.h>
 #include <asm/atomic.h>
 
@@ -161,6 +162,24 @@ static inline struct flowi *flowidn_to_flowi(struct flowidn *fldn)
 	return container_of(fldn, struct flowi, u.dn);
 }
 
+typedef unsigned long flow_compare_t;
+
+static inline size_t flow_key_size(u16 family)
+{
+	switch (family) {
+	case AF_INET:
+		BUILD_BUG_ON(sizeof(struct flowi4) % sizeof(flow_compare_t));
+		return sizeof(struct flowi4) / sizeof(flow_compare_t);
+	case AF_INET6:
+		BUILD_BUG_ON(sizeof(struct flowi6) % sizeof(flow_compare_t));
+		return sizeof(struct flowi6) / sizeof(flow_compare_t);
+	case AF_DECnet:
+		BUILD_BUG_ON(sizeof(struct flowidn) % sizeof(flow_compare_t));
+		return sizeof(struct flowidn) / sizeof(flow_compare_t);
+	}
+	return 0;
+}
+
 #define FLOW_DIR_IN	0
 #define FLOW_DIR_OUT	1
 #define FLOW_DIR_FWD	2
diff --git a/net/core/flow.c b/net/core/flow.c
index 990703b..a6bda2a 100644
--- a/net/core/flow.c
+++ b/net/core/flow.c
@@ -172,29 +172,26 @@ static void flow_new_hash_rnd(struct flow_cache *fc,
 
 static u32 flow_hash_code(struct flow_cache *fc,
 			  struct flow_cache_percpu *fcp,
-			  const struct flowi *key)
+			  const struct flowi *key,
+			  size_t keysize)
 {
 	const u32 *k = (const u32 *) key;
+	const u32 length = keysize * sizeof(flow_compare_t) / sizeof(u32);
 
-	return jhash2(k, (sizeof(*key) / sizeof(u32)), fcp->hash_rnd)
+	return jhash2(k, length, fcp->hash_rnd)
 		& (flow_cache_hash_size(fc) - 1);
 }
 
-typedef unsigned long flow_compare_t;
-
 /* I hear what you're saying, use memcmp.  But memcmp cannot make
- * important assumptions that we can here, such as alignment and
- * constant size.
+ * important assumptions that we can here, such as alignment.
  */
-static int flow_key_compare(const struct flowi *key1, const struct flowi *key2)
+static int flow_key_compare(const struct flowi *key1, const struct flowi *key2,
+			    size_t keysize)
 {
 	const flow_compare_t *k1, *k1_lim, *k2;
-	const int n_elem = sizeof(struct flowi) / sizeof(flow_compare_t);
-
-	BUILD_BUG_ON(sizeof(struct flowi) % sizeof(flow_compare_t));
 
 	k1 = (const flow_compare_t *) key1;
-	k1_lim = k1 + n_elem;
+	k1_lim = k1 + keysize;
 
 	k2 = (const flow_compare_t *) key2;
 
@@ -215,6 +212,7 @@ flow_cache_lookup(struct net *net, const struct flowi *key, u16 family, u8 dir,
 	struct flow_cache_entry *fle, *tfle;
 	struct hlist_node *entry;
 	struct flow_cache_object *flo;
+	size_t keysize;
 	unsigned int hash;
 
 	local_bh_disable();
@@ -222,6 +220,11 @@ flow_cache_lookup(struct net *net, const struct flowi *key, u16 family, u8 dir,
 
 	fle = NULL;
 	flo = NULL;
+
+	keysize = flow_key_size(family);
+	if (!keysize)
+		goto nocache;
+
 	/* Packet really early in init?  Making flow_cache_init a
 	 * pre-smp initcall would solve this.  --RR */
 	if (!fcp->hash_table)
@@ -230,11 +233,11 @@ flow_cache_lookup(struct net *net, const struct flowi *key, u16 family, u8 dir,
 	if (fcp->hash_rnd_recalc)
 		flow_new_hash_rnd(fc, fcp);
 
-	hash = flow_hash_code(fc, fcp, key);
+	hash = flow_hash_code(fc, fcp, key, keysize);
 	hlist_for_each_entry(tfle, entry, &fcp->hash_table[hash], u.hlist) {
 		if (tfle->family == family &&
 		    tfle->dir == dir &&
-		    flow_key_compare(key, &tfle->key) == 0) {
+		    flow_key_compare(key, &tfle->key, keysize) == 0) {
 			fle = tfle;
 			break;
 		}
@@ -248,7 +251,7 @@ flow_cache_lookup(struct net *net, const struct flowi *key, u16 family, u8 dir,
 		if (fle) {
 			fle->family = family;
 			fle->dir = dir;
-			memcpy(&fle->key, key, sizeof(*key));
+			memcpy(&fle->key, key, keysize * sizeof(flow_compare_t));
 			fle->object = NULL;
 			hlist_add_head(&fle->u.hlist, &fcp->hash_table[hash]);
 			fcp->hash_count++;
-- 
1.7.7.2

Re: [stable] net: Handle different key sizes between address families in flow cache

[David Miller]

From: Kim Phillips <kim.phillips@freescale.com>
Date: Fri, 4 Nov 2011 14:46:59 -0500

> commit aa1c366e4febc7f5c2b84958a2dd7cd70e28f9d0 upstream.
> 
> With the conversion of struct flowi to a union of AF-specific structs, some
> operations on the flow cache need to account for the exact size of the key.
> 
> Signed-off-by: David Ward <david.ward@ll.mit.edu>
> Signed-off-by: David S. Miller <davem@davemloft.net>
> Cc: stable@vger.kernel.org # v3.0.x

I'm fine with this, -stable folks please apply.

Thanks.

Re: [stable] net: Handle different key sizes between address families in flow cache

[Greg KH]

On Fri, Nov 04, 2011 at 02:46:59PM -0500, Kim Phillips wrote:
> commit aa1c366e4febc7f5c2b84958a2dd7cd70e28f9d0 upstream.
> 
> With the conversion of struct flowi to a union of AF-specific structs, some
> operations on the flow cache need to account for the exact size of the key.
> 
> Signed-off-by: David Ward <david.ward@ll.mit.edu>
> Signed-off-by: David S. Miller <davem@davemloft.net>
> Cc: stable@vger.kernel.org # v3.0.x
> ---
> This patch is the result of a clean cherry-pick onto v3.0.8.
> It restores IPSec fwding performance from ~4kpps back to ~44kpps on
> a P2020DS board.

Too bad you forgot to build this patch after you applied it:
  CC      init/main.o
In file included from include/linux/security.h:39:0,
                 from init/main.c:32:
include/net/flow.h: In function ‘flow_key_size’:
include/net/flow.h:174:3: error: size of unnamed array is negative
include/net/flow.h:177:3: error: size of unnamed array is negative

Please be kind to your poor over-worked stable kernel maintainer and do
the decent thing and TEST YOUR PATCH before you ask him to accept it.

bah, I think it's time for the weekend to start a bit earlier than normal...

greg k-h

Re: [stable] net: Handle different key sizes between address families in flow cache

[Kim Phillips]

On Fri, 4 Nov 2011 14:24:39 -0700
Greg KH <greg@kroah.com> wrote:

> On Fri, Nov 04, 2011 at 02:46:59PM -0500, Kim Phillips wrote:
> > commit aa1c366e4febc7f5c2b84958a2dd7cd70e28f9d0 upstream.
> > 
> > With the conversion of struct flowi to a union of AF-specific structs, some
> > operations on the flow cache need to account for the exact size of the key.
> > 
> > Signed-off-by: David Ward <david.ward@ll.mit.edu>
> > Signed-off-by: David S. Miller <davem@davemloft.net>
> > Cc: stable@vger.kernel.org # v3.0.x
> > ---
> > This patch is the result of a clean cherry-pick onto v3.0.8.
> > It restores IPSec fwding performance from ~4kpps back to ~44kpps on
> > a P2020DS board.
> 
> Too bad you forgot to build this patch after you applied it:
>   CC      init/main.o
> In file included from include/linux/security.h:39:0,
>                  from init/main.c:32:
> include/net/flow.h: In function 'flow_key_size':
> include/net/flow.h:174:3: error: size of unnamed array is negative
> include/net/flow.h:177:3: error: size of unnamed array is negative
> 
> Please be kind to your poor over-worked stable kernel maintainer and do
> the decent thing and TEST YOUR PATCH before you ask him to accept it.
> 
> bah, I think it's time for the weekend to start a bit earlier than normal...

so sorry I hadn't tested 64-bit.

I found the problem - upstream commit aa1c366 depends on
upstream commit 728871b:

commit 728871bc05afc8ff310b17dba3e57a2472792b13
Author: David Ward <david.ward@ll.mit.edu>
Date:   Mon Sep 5 16:47:23 2011 +0000

    net: Align AF-specific flowi structs to long
    
    AF-specific flowi structs are now passed to flow_key_compare, which must
    also be aligned to a long.
    
    Signed-off-by: David Ward <david.ward@ll.mit.edu>
    Signed-off-by: David S. Miller <davem@davemloft.net>

so, one more time, in stable sign-off area format:

Cc: <stable@vger.kernel.org> # v3.0.x: 728871b: net: Align AF-specific flowi structs to long
Cc: <stable@vger.kernel.org> # v3.0.x

build tested on 32- and 64-bit powerpc, and ARCH=x86
{i386,x86_64}_defconfig.

Kim

Re: [stable] net: Handle different key sizes between address families in flow cache

[Greg KH]

On Fri, Nov 04, 2011 at 09:29:58PM -0500, Kim Phillips wrote:
> On Fri, 4 Nov 2011 14:24:39 -0700
> Greg KH <greg@kroah.com> wrote:
> 
> > On Fri, Nov 04, 2011 at 02:46:59PM -0500, Kim Phillips wrote:
> > > commit aa1c366e4febc7f5c2b84958a2dd7cd70e28f9d0 upstream.
> > > 
> > > With the conversion of struct flowi to a union of AF-specific structs, some
> > > operations on the flow cache need to account for the exact size of the key.
> > > 
> > > Signed-off-by: David Ward <david.ward@ll.mit.edu>
> > > Signed-off-by: David S. Miller <davem@davemloft.net>
> > > Cc: stable@vger.kernel.org # v3.0.x
> > > ---
> > > This patch is the result of a clean cherry-pick onto v3.0.8.
> > > It restores IPSec fwding performance from ~4kpps back to ~44kpps on
> > > a P2020DS board.
> > 
> > Too bad you forgot to build this patch after you applied it:
> >   CC      init/main.o
> > In file included from include/linux/security.h:39:0,
> >                  from init/main.c:32:
> > include/net/flow.h: In function 'flow_key_size':
> > include/net/flow.h:174:3: error: size of unnamed array is negative
> > include/net/flow.h:177:3: error: size of unnamed array is negative
> > 
> > Please be kind to your poor over-worked stable kernel maintainer and do
> > the decent thing and TEST YOUR PATCH before you ask him to accept it.
> > 
> > bah, I think it's time for the weekend to start a bit earlier than normal...
> 
> so sorry I hadn't tested 64-bit.
> 
> I found the problem - upstream commit aa1c366 depends on
> upstream commit 728871b:
> 
> commit 728871bc05afc8ff310b17dba3e57a2472792b13
> Author: David Ward <david.ward@ll.mit.edu>
> Date:   Mon Sep 5 16:47:23 2011 +0000
> 
>     net: Align AF-specific flowi structs to long
>     
>     AF-specific flowi structs are now passed to flow_key_compare, which must
>     also be aligned to a long.
>     
>     Signed-off-by: David Ward <david.ward@ll.mit.edu>
>     Signed-off-by: David S. Miller <davem@davemloft.net>
> 
> so, one more time, in stable sign-off area format:
> 
> Cc: <stable@vger.kernel.org> # v3.0.x: 728871b: net: Align AF-specific flowi structs to long
> Cc: <stable@vger.kernel.org> # v3.0.x
> 
> build tested on 32- and 64-bit powerpc, and ARCH=x86
> {i386,x86_64}_defconfig.

Can you please resend the original patch I needed to apply here as well?
It's long-gone in my deleted inbox.

thanks,

greg k-h

[stable v2] net: Handle different key sizes between address families in flow cache

[Kim Phillips]

commit aa1c366e4febc7f5c2b84958a2dd7cd70e28f9d0 upstream.

With the conversion of struct flowi to a union of AF-specific structs, some
operations on the flow cache need to account for the exact size of the key.

Signed-off-by: David Ward <david.ward@ll.mit.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>
Cc: <stable@vger.kernel.org> # v3.0.x: 728871b: net: Align AF-specific flowi structs to long
Cc: <stable@vger.kernel.org> # v3.0.x
---
v2: resend, with 64-bit build fix dependency 728871b included in sign-off area

 include/net/flow.h |   19 +++++++++++++++++++
 net/core/flow.c    |   31 +++++++++++++++++--------------
 2 files changed, 36 insertions(+), 14 deletions(-)

diff --git a/include/net/flow.h b/include/net/flow.h
index c6d5fe5..93a8785 100644
--- a/include/net/flow.h
+++ b/include/net/flow.h
@@ -7,6 +7,7 @@
 #ifndef _NET_FLOW_H
 #define _NET_FLOW_H
 
+#include <linux/socket.h>
 #include <linux/in6.h>
 #include <asm/atomic.h>
 
@@ -161,6 +162,24 @@ static inline struct flowi *flowidn_to_flowi(struct flowidn *fldn)
 	return container_of(fldn, struct flowi, u.dn);
 }
 
+typedef unsigned long flow_compare_t;
+
+static inline size_t flow_key_size(u16 family)
+{
+	switch (family) {
+	case AF_INET:
+		BUILD_BUG_ON(sizeof(struct flowi4) % sizeof(flow_compare_t));
+		return sizeof(struct flowi4) / sizeof(flow_compare_t);
+	case AF_INET6:
+		BUILD_BUG_ON(sizeof(struct flowi6) % sizeof(flow_compare_t));
+		return sizeof(struct flowi6) / sizeof(flow_compare_t);
+	case AF_DECnet:
+		BUILD_BUG_ON(sizeof(struct flowidn) % sizeof(flow_compare_t));
+		return sizeof(struct flowidn) / sizeof(flow_compare_t);
+	}
+	return 0;
+}
+
 #define FLOW_DIR_IN	0
 #define FLOW_DIR_OUT	1
 #define FLOW_DIR_FWD	2
diff --git a/net/core/flow.c b/net/core/flow.c
index 990703b..a6bda2a 100644
--- a/net/core/flow.c
+++ b/net/core/flow.c
@@ -172,29 +172,26 @@ static void flow_new_hash_rnd(struct flow_cache *fc,
 
 static u32 flow_hash_code(struct flow_cache *fc,
 			  struct flow_cache_percpu *fcp,
-			  const struct flowi *key)
+			  const struct flowi *key,
+			  size_t keysize)
 {
 	const u32 *k = (const u32 *) key;
+	const u32 length = keysize * sizeof(flow_compare_t) / sizeof(u32);
 
-	return jhash2(k, (sizeof(*key) / sizeof(u32)), fcp->hash_rnd)
+	return jhash2(k, length, fcp->hash_rnd)
 		& (flow_cache_hash_size(fc) - 1);
 }
 
-typedef unsigned long flow_compare_t;
-
 /* I hear what you're saying, use memcmp.  But memcmp cannot make
- * important assumptions that we can here, such as alignment and
- * constant size.
+ * important assumptions that we can here, such as alignment.
  */
-static int flow_key_compare(const struct flowi *key1, const struct flowi *key2)
+static int flow_key_compare(const struct flowi *key1, const struct flowi *key2,
+			    size_t keysize)
 {
 	const flow_compare_t *k1, *k1_lim, *k2;
-	const int n_elem = sizeof(struct flowi) / sizeof(flow_compare_t);
-
-	BUILD_BUG_ON(sizeof(struct flowi) % sizeof(flow_compare_t));
 
 	k1 = (const flow_compare_t *) key1;
-	k1_lim = k1 + n_elem;
+	k1_lim = k1 + keysize;
 
 	k2 = (const flow_compare_t *) key2;
 
@@ -215,6 +212,7 @@ flow_cache_lookup(struct net *net, const struct flowi *key, u16 family, u8 dir,
 	struct flow_cache_entry *fle, *tfle;
 	struct hlist_node *entry;
 	struct flow_cache_object *flo;
+	size_t keysize;
 	unsigned int hash;
 
 	local_bh_disable();
@@ -222,6 +220,11 @@ flow_cache_lookup(struct net *net, const struct flowi *key, u16 family, u8 dir,
 
 	fle = NULL;
 	flo = NULL;
+
+	keysize = flow_key_size(family);
+	if (!keysize)
+		goto nocache;
+
 	/* Packet really early in init?  Making flow_cache_init a
 	 * pre-smp initcall would solve this.  --RR */
 	if (!fcp->hash_table)
@@ -230,11 +233,11 @@ flow_cache_lookup(struct net *net, const struct flowi *key, u16 family, u8 dir,
 	if (fcp->hash_rnd_recalc)
 		flow_new_hash_rnd(fc, fcp);
 
-	hash = flow_hash_code(fc, fcp, key);
+	hash = flow_hash_code(fc, fcp, key, keysize);
 	hlist_for_each_entry(tfle, entry, &fcp->hash_table[hash], u.hlist) {
 		if (tfle->family == family &&
 		    tfle->dir == dir &&
-		    flow_key_compare(key, &tfle->key) == 0) {
+		    flow_key_compare(key, &tfle->key, keysize) == 0) {
 			fle = tfle;
 			break;
 		}
@@ -248,7 +251,7 @@ flow_cache_lookup(struct net *net, const struct flowi *key, u16 family, u8 dir,
 		if (fle) {
 			fle->family = family;
 			fle->dir = dir;
-			memcpy(&fle->key, key, sizeof(*key));
+			memcpy(&fle->key, key, keysize * sizeof(flow_compare_t));
 			fle->object = NULL;
 			hlist_add_head(&fle->u.hlist, &fcp->hash_table[hash]);
 			fcp->hash_count++;
-- 
1.7.7.2