[PATCH net v2] bonding: enhance L2 hash helper with packet type

[PATCH net v2] bonding: enhance L2 hash helper with packet type

[Xie Jianhua]

From: Jianhua Xie <jianhua.xie@freescale.com>

Current L2 hash helper calculates destination eth addr and
source ether addr as L2 hash factors. This patch is adding
packet type ID field into hash factors, which can help to
distribute different types of packets like IPv4/IPv6 packets
to different slave devices while only BOND_XMIT_POLICY_LAYER2
is applied.

CC: Jay Vosburgh <j.vosburgh@gmail.com>
CC: Veaceslav Falico <vfalico@gmail.com>
CC: Andy Gospodarek <andy@greyhouse.net>
CC: David S. Miller <davem@davemloft.net>
CC: Pan Jiafei <Jiafei.Pan@freescale.com>

Suggested-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jianhua Xie <jianhua.xie@freescale.com>
---

v2-changes:
 Use the appropriate interface skb_header_pointer()
 to check skb headlen, fragmented packet or not is
 not distinguished any more.


 drivers/net/bonding/bond_main.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 3a451b6..bcff90c 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -2999,11 +2999,11 @@ static struct notifier_block bond_netdev_notifier = {
 /* L2 hash helper */
 static inline u32 bond_eth_hash(struct sk_buff *skb)
 {
-	struct ethhdr *data = (struct ethhdr *)skb->data;
-
-	if (skb_headlen(skb) >= offsetof(struct ethhdr, h_proto))
-		return data->h_dest[5] ^ data->h_source[5];
+	struct ethhdr *ep, hdr_tmp;
 
+	ep = skb_header_pointer(skb, 0, sizeof(hdr_tmp), &hdr_tmp);
+	if (ep)
+		return ep->h_dest[5] ^ ep->h_source[5] ^ ep->h_proto;
 	return 0;
 }
 
-- 
1.8.5

Re: [PATCH net v2] bonding: enhance L2 hash helper with packet type

[Eric Dumazet]

On Tue, 2014-07-15 at 15:41 +0800, Xie Jianhua wrote:
> From: Jianhua Xie <jianhua.xie@freescale.com>
> 
> Current L2 hash helper calculates destination eth addr and
> source ether addr as L2 hash factors. This patch is adding
> packet type ID field into hash factors, which can help to
> distribute different types of packets like IPv4/IPv6 packets
> to different slave devices while only BOND_XMIT_POLICY_LAYER2
> is applied.
> 
> CC: Jay Vosburgh <j.vosburgh@gmail.com>
> CC: Veaceslav Falico <vfalico@gmail.com>
> CC: Andy Gospodarek <andy@greyhouse.net>
> CC: David S. Miller <davem@davemloft.net>
> CC: Pan Jiafei <Jiafei.Pan@freescale.com>
> 
> Suggested-by: David S. Miller <davem@davemloft.net>

I do not think this patch was suggested by David.

He suggested to use skb_header_pointer() which is an implementation
detail.

Anyway, patch looks fine, even if bond_eth_hash() is no longer a leaf
function.

Acked-by: Eric Dumazet <edumazet@google.com>

Re: [PATCH net v2] bonding: enhance L2 hash helper with packet type

[Veaceslav Falico]

On Tue, Jul 15, 2014 at 03:41:23PM +0800, Xie Jianhua wrote:
>From: Jianhua Xie <jianhua.xie@freescale.com>
>
>Current L2 hash helper calculates destination eth addr and
>source ether addr as L2 hash factors. This patch is adding
>packet type ID field into hash factors, which can help to
>distribute different types of packets like IPv4/IPv6 packets
>to different slave devices while only BOND_XMIT_POLICY_LAYER2
>is applied.

1) It's also used in BOND_XMIT_POLICY_{LAYER|ENCAP}23, for the 2nd level
hash.
2) The documentation (D/networking/bonding.txt) also needs an update.

Otherwise, looks good.

>
>CC: Jay Vosburgh <j.vosburgh@gmail.com>
>CC: Veaceslav Falico <vfalico@gmail.com>
>CC: Andy Gospodarek <andy@greyhouse.net>
>CC: David S. Miller <davem@davemloft.net>
>CC: Pan Jiafei <Jiafei.Pan@freescale.com>
>
>Suggested-by: David S. Miller <davem@davemloft.net>
>Signed-off-by: Jianhua Xie <jianhua.xie@freescale.com>
>---
>
>v2-changes:
> Use the appropriate interface skb_header_pointer()
> to check skb headlen, fragmented packet or not is
> not distinguished any more.
>
>
> drivers/net/bonding/bond_main.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
>diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
>index 3a451b6..bcff90c 100644
>--- a/drivers/net/bonding/bond_main.c
>+++ b/drivers/net/bonding/bond_main.c
>@@ -2999,11 +2999,11 @@ static struct notifier_block bond_netdev_notifier = {
> /* L2 hash helper */
> static inline u32 bond_eth_hash(struct sk_buff *skb)
> {
>-	struct ethhdr *data = (struct ethhdr *)skb->data;
>-
>-	if (skb_headlen(skb) >= offsetof(struct ethhdr, h_proto))
>-		return data->h_dest[5] ^ data->h_source[5];
>+	struct ethhdr *ep, hdr_tmp;
>
>+	ep = skb_header_pointer(skb, 0, sizeof(hdr_tmp), &hdr_tmp);
>+	if (ep)
>+		return ep->h_dest[5] ^ ep->h_source[5] ^ ep->h_proto;
> 	return 0;
> }
>
>-- 
>1.8.5
>

Re: [PATCH net v2] bonding: enhance L2 hash helper with packet type

[David Miller]

From: Veaceslav Falico <vfalico@gmail.com>
Date: Tue, 15 Jul 2014 10:20:28 +0200

> On Tue, Jul 15, 2014 at 03:41:23PM +0800, Xie Jianhua wrote:
>>From: Jianhua Xie <jianhua.xie@freescale.com>
>>
>>Current L2 hash helper calculates destination eth addr and
>>source ether addr as L2 hash factors. This patch is adding
>>packet type ID field into hash factors, which can help to
>>distribute different types of packets like IPv4/IPv6 packets
>>to different slave devices while only BOND_XMIT_POLICY_LAYER2
>>is applied.
> 
> 1) It's also used in BOND_XMIT_POLICY_{LAYER|ENCAP}23, for the 2nd
> level
> hash.
> 2) The documentation (D/networking/bonding.txt) also needs an update.
> 
> Otherwise, looks good.

Please make these adjustments and resubmit this patch, thank you.