[RESEND] [RFC PATCH] bonding: Do not tx-balance some IPv6 packets on ALB/TLB bonds

[RESEND] [RFC PATCH] bonding: Do not tx-balance some IPv6 packets on ALB/TLB bonds

[Vlad Yasevich]

It's been more then a month and still no replies.  Is this just
not interesting, or did this get lost in the shuffle...

Please take a look.  This patch makes ALB/TLB modes work much more
reliably with IPv6.

Thanks
-vlad

---

I've been trying to configure IPv6 on ALB and TLB bonds and have found
that there is a 50-50 chance that IPv6 doesn't configure a global address
on such bond.  After further investigation, it appears that DAD probes are
tx-balanced between the bond members.  When the DAD probe is sent on the
secondary device, it ends up arriving back on the primary, since that interface
is also in the multicast group.  As a result, we get a false positive duplicate
address and fail to configure a global IPv6 address.  The easy solution seems
to be to not tx-balance DAD problems.  Also, we should probably not balance
all-note-mulicasts as well since they are the equivalent of IPv4 broadcasts.

---

IPv6 all-node-multicasts and DAD probes should not be tx-balanced
on ALB/TLB bonds.  The all-node-multicast is an equivalent to IPv4
broadcasts.  DAD probes have to be sent only on the primary so that
we don't get false-positive detections.

Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
---
 drivers/net/bonding/bond_alb.c |   24 ++++++++++++++++++++++++
 1 files changed, 24 insertions(+), 0 deletions(-)

diff --git a/drivers/net/bonding/bond_alb.c b/drivers/net/bonding/bond_alb.c
index 5a67372..684440c 100644
--- a/drivers/net/bonding/bond_alb.c
+++ b/drivers/net/bonding/bond_alb.c
@@ -38,6 +38,7 @@
 #include <linux/in.h>
 #include <net/ipx.h>
 #include <net/arp.h>
+#include <net/ipv6.h>
 #include <asm/byteorder.h>
 #include "bonding.h"
 #include "bond_alb.h"
@@ -81,6 +82,7 @@
 #define RLB_PROMISC_TIMEOUT	10*ALB_TIMER_TICKS_PER_SEC
 
 static const u8 mac_bcast[ETH_ALEN] = {0xff,0xff,0xff,0xff,0xff,0xff};
+static const u8 mac_v6_allmcast[ETH_ALEN] = {0x33,0x33,0x00,0x00,0x00,0x01};
 static const int alb_delta_in_ticks = HZ / ALB_TIMER_TICKS_PER_SEC;
 
 #pragma pack(1)
@@ -1288,6 +1290,7 @@ int bond_alb_xmit(struct sk_buff *skb, struct net_device *bond_dev)
 	u32 hash_index = 0;
 	const u8 *hash_start = NULL;
 	int res = 1;
+	struct ipv6hdr *ip6hdr;
 
 	skb_reset_mac_header(skb);
 	eth_data = eth_hdr(skb);
@@ -1317,11 +1320,32 @@ int bond_alb_xmit(struct sk_buff *skb, struct net_device *bond_dev)
 	}
 		break;
 	case ETH_P_IPV6:
+		/* IPv6 doesn't really use broadcast mac address, but leave
+		 * that here just in case.
+		 */
 		if (memcmp(eth_data->h_dest, mac_bcast, ETH_ALEN) == 0) {
 			do_tx_balance = 0;
 			break;
 		}
 
+		/* IPv6 uses all-nodes multicast as an equivalent to
+		 * broadcasts in IPv4.
+		 */
+		if (memcmp(eth_data->h_dest, mac_v6_allmcast, ETH_ALEN) == 0) {
+			do_tx_balance = 0;
+			break;
+		}
+
+		/* Additianally, DAD probes should not be tx-balanced as that
+		 * will lead to false positives for duplicate addresses and
+		 * prevent address configuration from working.
+		 */
+		ip6hdr = ipv6_hdr(skb);
+		if (ipv6_addr_any(&ip6hdr->saddr)) {
+			do_tx_balance = 0;
+			break;
+		}
+
 		hash_start = (char *)&(ipv6_hdr(skb)->daddr);
 		hash_size = sizeof(ipv6_hdr(skb)->daddr);
 		break;
-- 
1.5.3.5
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Re: [RESEND] [RFC PATCH] bonding: Do not tx-balance some IPv6 packets on ALB/TLB bonds

[David Miller]

From: Vlad Yasevich <vladislav.yasevich@hp.com>
Date: Thu, 28 Aug 2008 15:38:41 -0400

> It's been more then a month and still no replies.  Is this just
> not interesting, or did this get lost in the shuffle...
> 
> Please take a look.  This patch makes ALB/TLB modes work much more
> reliably with IPv6.

Jeff, or someone, please be sure to pick this up.

Thanks.

> I've been trying to configure IPv6 on ALB and TLB bonds and have found
> that there is a 50-50 chance that IPv6 doesn't configure a global address
> on such bond.  After further investigation, it appears that DAD probes are
> tx-balanced between the bond members.  When the DAD probe is sent on the
> secondary device, it ends up arriving back on the primary, since that interface
> is also in the multicast group.  As a result, we get a false positive duplicate
> address and fail to configure a global IPv6 address.  The easy solution seems
> to be to not tx-balance DAD problems.  Also, we should probably not balance
> all-note-mulicasts as well since they are the equivalent of IPv4 broadcasts.
> 
> ---
> 
> IPv6 all-node-multicasts and DAD probes should not be tx-balanced
> on ALB/TLB bonds.  The all-node-multicast is an equivalent to IPv4
> broadcasts.  DAD probes have to be sent only on the primary so that
> we don't get false-positive detections.
> 
> Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
> ---
>  drivers/net/bonding/bond_alb.c |   24 ++++++++++++++++++++++++
>  1 files changed, 24 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/net/bonding/bond_alb.c b/drivers/net/bonding/bond_alb.c
> index 5a67372..684440c 100644
> --- a/drivers/net/bonding/bond_alb.c
> +++ b/drivers/net/bonding/bond_alb.c
> @@ -38,6 +38,7 @@
>  #include <linux/in.h>
>  #include <net/ipx.h>
>  #include <net/arp.h>
> +#include <net/ipv6.h>
>  #include <asm/byteorder.h>
>  #include "bonding.h"
>  #include "bond_alb.h"
> @@ -81,6 +82,7 @@
>  #define RLB_PROMISC_TIMEOUT	10*ALB_TIMER_TICKS_PER_SEC
>  
>  static const u8 mac_bcast[ETH_ALEN] = {0xff,0xff,0xff,0xff,0xff,0xff};
> +static const u8 mac_v6_allmcast[ETH_ALEN] = {0x33,0x33,0x00,0x00,0x00,0x01};
>  static const int alb_delta_in_ticks = HZ / ALB_TIMER_TICKS_PER_SEC;
>  
>  #pragma pack(1)
> @@ -1288,6 +1290,7 @@ int bond_alb_xmit(struct sk_buff *skb, struct net_device *bond_dev)
>  	u32 hash_index = 0;
>  	const u8 *hash_start = NULL;
>  	int res = 1;
> +	struct ipv6hdr *ip6hdr;
>  
>  	skb_reset_mac_header(skb);
>  	eth_data = eth_hdr(skb);
> @@ -1317,11 +1320,32 @@ int bond_alb_xmit(struct sk_buff *skb, struct net_device *bond_dev)
>  	}
>  		break;
>  	case ETH_P_IPV6:
> +		/* IPv6 doesn't really use broadcast mac address, but leave
> +		 * that here just in case.
> +		 */
>  		if (memcmp(eth_data->h_dest, mac_bcast, ETH_ALEN) == 0) {
>  			do_tx_balance = 0;
>  			break;
>  		}
>  
> +		/* IPv6 uses all-nodes multicast as an equivalent to
> +		 * broadcasts in IPv4.
> +		 */
> +		if (memcmp(eth_data->h_dest, mac_v6_allmcast, ETH_ALEN) == 0) {
> +			do_tx_balance = 0;
> +			break;
> +		}
> +
> +		/* Additianally, DAD probes should not be tx-balanced as that
> +		 * will lead to false positives for duplicate addresses and
> +		 * prevent address configuration from working.
> +		 */
> +		ip6hdr = ipv6_hdr(skb);
> +		if (ipv6_addr_any(&ip6hdr->saddr)) {
> +			do_tx_balance = 0;
> +			break;
> +		}
> +
>  		hash_start = (char *)&(ipv6_hdr(skb)->daddr);
>  		hash_size = sizeof(ipv6_hdr(skb)->daddr);
>  		break;
> -- 
> 1.5.3.5
> --
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> 

Re: [RESEND] [RFC PATCH] bonding: Do not tx-balance some IPv6 packets on ALB/TLB bonds

[Jeff Garzik]

David Miller wrote:
> From: Vlad Yasevich <vladislav.yasevich@hp.com>
> Date: Thu, 28 Aug 2008 15:38:41 -0400
> 
>> It's been more then a month and still no replies.  Is this just
>> not interesting, or did this get lost in the shuffle...
>>
>> Please take a look.  This patch makes ALB/TLB modes work much more
>> reliably with IPv6.
> 
> Jeff, or someone, please be sure to pick this up.

For 2.6.27-rc, I presume?

Re: [RESEND] [RFC PATCH] bonding: Do not tx-balance some IPv6 packets on ALB/TLB bonds

[Vlad Yasevich]

Jeff Garzik wrote:
> David Miller wrote:
>> From: Vlad Yasevich <vladislav.yasevich@hp.com>
>> Date: Thu, 28 Aug 2008 15:38:41 -0400
>>
>>> It's been more then a month and still no replies.  Is this just
>>> not interesting, or did this get lost in the shuffle...
>>>
>>> Please take a look.  This patch makes ALB/TLB modes work much more
>>> reliably with IPv6.
>>
>> Jeff, or someone, please be sure to pick this up.
> 
> For 2.6.27-rc, I presume?
> 
> 

Fine by me.

Thanks
-vlad

Re: [RESEND] [RFC PATCH] bonding: Do not tx-balance some IPv6 packets on ALB/TLB bonds

[Jay Vosburgh]

Jeff Garzik <jgarzik@pobox.com> wrote:

>David Miller wrote:
>> From: Vlad Yasevich <vladislav.yasevich@hp.com>
>> Date: Thu, 28 Aug 2008 15:38:41 -0400
>>
>>> It's been more then a month and still no replies.  Is this just
>>> not interesting, or did this get lost in the shuffle...
>>>
>>> Please take a look.  This patch makes ALB/TLB modes work much more
>>> reliably with IPv6.
>>
>> Jeff, or someone, please be sure to pick this up.
>
>For 2.6.27-rc, I presume?

	Ok with me.  I haven't tested this yet (just got back from
vacation), but the description sounds reasonable.

	-J

---
	-Jay Vosburgh, IBM Linux Technology Center, fubar@us.ibm.com

Re: [RESEND] [RFC PATCH] bonding: Do not tx-balance some IPv6 packets on ALB/TLB bonds

[Jeff Garzik]

Vlad Yasevich wrote:
> It's been more then a month and still no replies.  Is this just
> not interesting, or did this get lost in the shuffle...
> 
> Please take a look.  This patch makes ALB/TLB modes work much more
> reliably with IPv6.
> 
> Thanks
> -vlad
> 
> ---
> 
> I've been trying to configure IPv6 on ALB and TLB bonds and have found
> that there is a 50-50 chance that IPv6 doesn't configure a global address
> on such bond.  After further investigation, it appears that DAD probes are
> tx-balanced between the bond members.  When the DAD probe is sent on the
> secondary device, it ends up arriving back on the primary, since that interface
> is also in the multicast group.  As a result, we get a false positive duplicate
> address and fail to configure a global IPv6 address.  The easy solution seems
> to be to not tx-balance DAD problems.  Also, we should probably not balance
> all-note-mulicasts as well since they are the equivalent of IPv4 broadcasts.
> 
> ---
> 
> IPv6 all-node-multicasts and DAD probes should not be tx-balanced
> on ALB/TLB bonds.  The all-node-multicast is an equivalent to IPv4
> broadcasts.  DAD probes have to be sent only on the primary so that
> we don't get false-positive detections.
> 
> Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
> ---
>  drivers/net/bonding/bond_alb.c |   24 ++++++++++++++++++++++++
>  1 files changed, 24 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/net/bonding/bond_alb.c b/drivers/net/bonding/bond_alb.c
> index 5a67372..684440c 100644
> --- a/drivers/net/bonding/bond_alb.c
> +++ b/drivers/net/bonding/bond_alb.c
> @@ -38,6 +38,7 @@
>  #include <linux/in.h>
>  #include <net/ipx.h>
>  #include <net/arp.h>
> +#include <net/ipv6.h>
>  #include <asm/byteorder.h>
>  #include "bonding.h"
>  #include "bond_alb.h"
> @@ -81,6 +82,7 @@
>  #define RLB_PROMISC_TIMEOUT	10*ALB_TIMER_TICKS_PER_SEC
>  
>  static const u8 mac_bcast[ETH_ALEN] = {0xff,0xff,0xff,0xff,0xff,0xff};
> +static const u8 mac_v6_allmcast[ETH_ALEN] = {0x33,0x33,0x00,0x00,0x00,0x01};
>  static const int alb_delta_in_ticks = HZ / ALB_TIMER_TICKS_PER_SEC;
>  
>  #pragma pack(1)
> @@ -1288,6 +1290,7 @@ int bond_alb_xmit(struct sk_buff *skb, struct net_device *bond_dev)
>  	u32 hash_index = 0;
>  	const u8 *hash_start = NULL;
>  	int res = 1;
> +	struct ipv6hdr *ip6hdr;
>  
>  	skb_reset_mac_header(skb);
>  	eth_data = eth_hdr(skb);
> @@ -1317,11 +1320,32 @@ int bond_alb_xmit(struct sk_buff *skb, struct net_device *bond_dev)
>  	}
>  		break;
>  	case ETH_P_IPV6:
> +		/* IPv6 doesn't really use broadcast mac address, but leave
> +		 * that here just in case.
> +		 */
>  		if (memcmp(eth_data->h_dest, mac_bcast, ETH_ALEN) == 0) {
>  			do_tx_balance = 0;
>  			break;
>  		}
>  
> +		/* IPv6 uses all-nodes multicast as an equivalent to
> +		 * broadcasts in IPv4.
> +		 */
> +		if (memcmp(eth_data->h_dest, mac_v6_allmcast, ETH_ALEN) == 0) {
> +			do_tx_balance = 0;
> +			break;
> +		}
> +
> +		/* Additianally, DAD probes should not be tx-balanced as that
> +		 * will lead to false positives for duplicate addresses and
> +		 * prevent address configuration from working.
> +		 */
> +		ip6hdr = ipv6_hdr(skb);
> +		if (ipv6_addr_any(&ip6hdr->saddr)) {
> +			do_tx_balance = 0;
> +			break;
> +		}
> +
>  		hash_start = (char *)&(ipv6_hdr(skb)->daddr);

applied