Patchwork bonding: 802.3ad: make aggregator_identifier bond-private

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Submitter Jiri Bohac
Date Feb. 14, 2014, 5:13 p.m.
Message ID <20140214171350.GC11688@midget.suse.cz>
Download mbox | patch
Permalink /patch/320495/
State Accepted
Delegated to: David Miller
Headers show

Comments

Jiri Bohac - Feb. 14, 2014, 5:13 p.m.
aggregator_identifier is used to assign unique aggregator identifiers
to aggregators of a bond during device enslaving.

aggregator_identifier is currently a global variable that is zeroed in
bond_3ad_initialize().

This sequence will lead to duplicate aggregator identifiers for eth1 and eth3:

create bond0
change bond0 mode to 802.3ad
enslave eth0 to bond0 		//eth0 gets agg id 1
enslave eth1 to bond0 		//eth1 gets agg id 2
create bond1
change bond1 mode to 802.3ad
enslave eth2 to bond1		//aggregator_identifier is reset to 0
				//eth2 gets agg id 1
enslave eth3 to bond0 		//eth3 gets agg id 2

Fix this by making aggregator_identifier private to the bond.

Signed-off-by: Jiri Bohac <jbohac@suse.cz>
---
 drivers/net/bonding/bond_3ad.c | 6 ++----
 drivers/net/bonding/bond_3ad.h | 1 +
 2 files changed, 3 insertions(+), 4 deletions(-)
Veaceslav Falico - Feb. 14, 2014, 5:18 p.m.
On Fri, Feb 14, 2014 at 06:13:50PM +0100, Jiri Bohac wrote:
>aggregator_identifier is used to assign unique aggregator identifiers
>to aggregators of a bond during device enslaving.
>
>aggregator_identifier is currently a global variable that is zeroed in
>bond_3ad_initialize().
>
>This sequence will lead to duplicate aggregator identifiers for eth1 and eth3:
>
>create bond0
>change bond0 mode to 802.3ad
>enslave eth0 to bond0 		//eth0 gets agg id 1
>enslave eth1 to bond0 		//eth1 gets agg id 2
>create bond1
>change bond1 mode to 802.3ad
>enslave eth2 to bond1		//aggregator_identifier is reset to 0
>				//eth2 gets agg id 1
>enslave eth3 to bond0 		//eth3 gets agg id 2
>
>Fix this by making aggregator_identifier private to the bond.
>
>Signed-off-by: Jiri Bohac <jbohac@suse.cz>

Acked-by: Veaceslav Falico <vfalico@redhat.com>

>---
> drivers/net/bonding/bond_3ad.c | 6 ++----
> drivers/net/bonding/bond_3ad.h | 1 +
> 2 files changed, 3 insertions(+), 4 deletions(-)
>
>diff --git a/drivers/net/bonding/bond_3ad.c b/drivers/net/bonding/bond_3ad.c
>index 4ced594..dcf2ee8 100644
>--- a/drivers/net/bonding/bond_3ad.c
>+++ b/drivers/net/bonding/bond_3ad.c
>@@ -1806,8 +1806,6 @@ void bond_3ad_initiate_agg_selection(struct bonding *bond, int timeout)
> 	BOND_AD_INFO(bond).agg_select_timer = timeout;
> }
>
>-static u16 aggregator_identifier;
>-
> /**
>  * bond_3ad_initialize - initialize a bond's 802.3ad parameters and structures
>  * @bond: bonding struct to work on
>@@ -1821,7 +1819,7 @@ void bond_3ad_initialize(struct bonding *bond, u16 tick_resolution)
> 	if (MAC_ADDRESS_COMPARE(&(BOND_AD_INFO(bond).system.sys_mac_addr),
> 				bond->dev->dev_addr)) {
>
>-		aggregator_identifier = 0;
>+		BOND_AD_INFO(bond).aggregator_identifier = 0;
>
> 		BOND_AD_INFO(bond).system.sys_priority = 0xFFFF;
> 		BOND_AD_INFO(bond).system.sys_mac_addr = *((struct mac_addr *)bond->dev->dev_addr);
>@@ -1892,7 +1890,7 @@ int bond_3ad_bind_slave(struct slave *slave)
> 		ad_initialize_agg(aggregator);
>
> 		aggregator->aggregator_mac_address = *((struct mac_addr *)bond->dev->dev_addr);
>-		aggregator->aggregator_identifier = (++aggregator_identifier);
>+		aggregator->aggregator_identifier = ++BOND_AD_INFO(bond).aggregator_identifier;
> 		aggregator->slave = slave;
> 		aggregator->is_active = 0;
> 		aggregator->num_of_ports = 0;
>diff --git a/drivers/net/bonding/bond_3ad.h b/drivers/net/bonding/bond_3ad.h
>index 5d91ad0..1f081c8 100644
>--- a/drivers/net/bonding/bond_3ad.h
>+++ b/drivers/net/bonding/bond_3ad.h
>@@ -253,6 +253,7 @@ struct ad_system {
> struct ad_bond_info {
> 	struct ad_system system;	    /* 802.3ad system structure */
> 	u32 agg_select_timer;	    // Timer to select aggregator after all adapter's hand shakes
>+	u16 aggregator_identifier;
> };
>
> struct ad_slave_info {
>
>-- 
>Jiri Bohac
>e-mail/jabber: jiri@boha.cz
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Flavio Leitner - Feb. 14, 2014, 7:12 p.m.
On Fri, Feb 14, 2014 at 06:13:50PM +0100, Jiri Bohac wrote:
> aggregator_identifier is used to assign unique aggregator identifiers
> to aggregators of a bond during device enslaving.
> 
> aggregator_identifier is currently a global variable that is zeroed in
> bond_3ad_initialize().
> 
> This sequence will lead to duplicate aggregator identifiers for eth1 and eth3:
> 
> create bond0
> change bond0 mode to 802.3ad
> enslave eth0 to bond0 		//eth0 gets agg id 1
> enslave eth1 to bond0 		//eth1 gets agg id 2
> create bond1
> change bond1 mode to 802.3ad
> enslave eth2 to bond1		//aggregator_identifier is reset to 0
> 				//eth2 gets agg id 1
> enslave eth3 to bond0 		//eth3 gets agg id 2
> 
> Fix this by making aggregator_identifier private to the bond.

I don't see how you fix the duplicate agg id with this patch because
you initialize for each bond to 0, then use the same algo further on.
So, what is changing?

Actually, aggregator_identifier is a global variable to make sure the
counter is always increasing for new bonds.  So, the fix would be to
not reset it to zero, isn't it?

Thanks,
fbl 


> Signed-off-by: Jiri Bohac <jbohac@suse.cz>
> ---
>  drivers/net/bonding/bond_3ad.c | 6 ++----
>  drivers/net/bonding/bond_3ad.h | 1 +
>  2 files changed, 3 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/net/bonding/bond_3ad.c b/drivers/net/bonding/bond_3ad.c
> index 4ced594..dcf2ee8 100644
> --- a/drivers/net/bonding/bond_3ad.c
> +++ b/drivers/net/bonding/bond_3ad.c
> @@ -1806,8 +1806,6 @@ void bond_3ad_initiate_agg_selection(struct bonding *bond, int timeout)
>  	BOND_AD_INFO(bond).agg_select_timer = timeout;
>  }
>  
> -static u16 aggregator_identifier;
> -
>  /**
>   * bond_3ad_initialize - initialize a bond's 802.3ad parameters and structures
>   * @bond: bonding struct to work on
> @@ -1821,7 +1819,7 @@ void bond_3ad_initialize(struct bonding *bond, u16 tick_resolution)
>  	if (MAC_ADDRESS_COMPARE(&(BOND_AD_INFO(bond).system.sys_mac_addr),
>  				bond->dev->dev_addr)) {
>  
> -		aggregator_identifier = 0;
> +		BOND_AD_INFO(bond).aggregator_identifier = 0;
>  
>  		BOND_AD_INFO(bond).system.sys_priority = 0xFFFF;
>  		BOND_AD_INFO(bond).system.sys_mac_addr = *((struct mac_addr *)bond->dev->dev_addr);
> @@ -1892,7 +1890,7 @@ int bond_3ad_bind_slave(struct slave *slave)
>  		ad_initialize_agg(aggregator);
>  
>  		aggregator->aggregator_mac_address = *((struct mac_addr *)bond->dev->dev_addr);
> -		aggregator->aggregator_identifier = (++aggregator_identifier);
> +		aggregator->aggregator_identifier = ++BOND_AD_INFO(bond).aggregator_identifier;
>  		aggregator->slave = slave;
>  		aggregator->is_active = 0;
>  		aggregator->num_of_ports = 0;
> diff --git a/drivers/net/bonding/bond_3ad.h b/drivers/net/bonding/bond_3ad.h
> index 5d91ad0..1f081c8 100644
> --- a/drivers/net/bonding/bond_3ad.h
> +++ b/drivers/net/bonding/bond_3ad.h
> @@ -253,6 +253,7 @@ struct ad_system {
>  struct ad_bond_info {
>  	struct ad_system system;	    /* 802.3ad system structure */
>  	u32 agg_select_timer;	    // Timer to select aggregator after all adapter's hand shakes
> +	u16 aggregator_identifier;
>  };
>  
>  struct ad_slave_info {
> 
> -- 
> Jiri Bohac
> e-mail/jabber: jiri@boha.cz
> --
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Jiri Bohac - Feb. 14, 2014, 8:51 p.m.
On Fri, Feb 14, 2014 at 05:12:43PM -0200, Flavio Leitner wrote:
> On Fri, Feb 14, 2014 at 06:13:50PM +0100, Jiri Bohac wrote:
> > Fix this by making aggregator_identifier private to the bond.
> 
> I don't see how you fix the duplicate agg id with this patch because
> you initialize for each bond to 0, then use the same algo further on.
> So, what is changing?

My understanding is that the aggregator identifier is used
internally by the bond and never appears anywhere in the LACP
traffic.

So having duplicate aggregator ids between two bonds on the same
machine does not matter. But it is a problem if two aggregators
in the same bond share the same id.

Is my understanding wrong?
 
> Actually, aggregator_identifier is a global variable to make sure the
> counter is always increasing for new bonds.  So, the fix would be to
> not reset it to zero, isn't it?

I was considering this fix, but my concern was that the variable
(u16) would overflow sooner than it does now. It would take 2^16
enslavings on the machine, while with my patch you need 2^16
enslavings on a single bond.

Hypothetically, a rogue NET_ADMIN in one net namespace may cause
this overflow to break a bond in another nemespace.

Maybe I'm being paranoid? ;)
Jay Vosburgh - Feb. 14, 2014, 9:16 p.m.
Jiri Bohac <jbohac@suse.cz> wrote:

>On Fri, Feb 14, 2014 at 05:12:43PM -0200, Flavio Leitner wrote:
>> On Fri, Feb 14, 2014 at 06:13:50PM +0100, Jiri Bohac wrote:
>> > Fix this by making aggregator_identifier private to the bond.
>> 
>> I don't see how you fix the duplicate agg id with this patch because
>> you initialize for each bond to 0, then use the same algo further on.
>> So, what is changing?
>
>My understanding is that the aggregator identifier is used
>internally by the bond and never appears anywhere in the LACP
>traffic.
>
>So having duplicate aggregator ids between two bonds on the same
>machine does not matter. But it is a problem if two aggregators
>in the same bond share the same id.
>
>Is my understanding wrong?

	Your understanding is correct.

>> Actually, aggregator_identifier is a global variable to make sure the
>> counter is always increasing for new bonds.  So, the fix would be to
>> not reset it to zero, isn't it?
>
>I was considering this fix, but my concern was that the variable
>(u16) would overflow sooner than it does now. It would take 2^16
>enslavings on the machine, while with my patch you need 2^16
>enslavings on a single bond.
>
>Hypothetically, a rogue NET_ADMIN in one net namespace may cause
>this overflow to break a bond in another nemespace.
>
>Maybe I'm being paranoid? ;)

	Personally, for ease of reading debug messages, I would prefer
the globally unique ID (or a patch to update the pr_debugs to add the
bond name).  From a technical point of view either way will function
correctly.  I'm not too worried about the overflow of the ID.

	-J

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

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Flavio Leitner - Feb. 14, 2014, 9:48 p.m.
On Fri, Feb 14, 2014 at 09:51:47PM +0100, Jiri Bohac wrote:
> On Fri, Feb 14, 2014 at 05:12:43PM -0200, Flavio Leitner wrote:
> > On Fri, Feb 14, 2014 at 06:13:50PM +0100, Jiri Bohac wrote:
> > > Fix this by making aggregator_identifier private to the bond.
> > 
> > I don't see how you fix the duplicate agg id with this patch because
> > you initialize for each bond to 0, then use the same algo further on.
> > So, what is changing?
> 
> My understanding is that the aggregator identifier is used
> internally by the bond and never appears anywhere in the LACP
> traffic.
> 
> So having duplicate aggregator ids between two bonds on the same
> machine does not matter. But it is a problem if two aggregators
> in the same bond share the same id.
> 
> Is my understanding wrong?

No, I agree that having two agg id in the same bond is a problem
while we can have the same agg id in different bonds.

> > Actually, aggregator_identifier is a global variable to make sure the
> > counter is always increasing for new bonds.  So, the fix would be to
> > not reset it to zero, isn't it?
> 
> I was considering this fix, but my concern was that the variable
> (u16) would overflow sooner than it does now. It would take 2^16
> enslavings on the machine, while with my patch you need 2^16
> enslavings on a single bond.
> 
> Hypothetically, a rogue NET_ADMIN in one net namespace may cause
> this overflow to break a bond in another nemespace.

Well, I think it is easier to troubleshoot if you have one agg id
regardless of bonding. Also, the id is visible in /proc and I
recall to have seen a script using it somehow, but yeah you made a
good point.
 
> Maybe I'm being paranoid? ;)

I will defer to bonding maintainer to decide. :P

Thanks,
fbl
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David Miller - Feb. 17, 2014, 7:55 p.m.
From: Jiri Bohac <jiri@boha.cz>
Date: Fri, 14 Feb 2014 18:13:50 +0100

> aggregator_identifier is used to assign unique aggregator identifiers
> to aggregators of a bond during device enslaving.
> 
> aggregator_identifier is currently a global variable that is zeroed in
> bond_3ad_initialize().
> 
> This sequence will lead to duplicate aggregator identifiers for eth1 and eth3:
> 
> create bond0
> change bond0 mode to 802.3ad
> enslave eth0 to bond0 		//eth0 gets agg id 1
> enslave eth1 to bond0 		//eth1 gets agg id 2
> create bond1
> change bond1 mode to 802.3ad
> enslave eth2 to bond1		//aggregator_identifier is reset to 0
> 				//eth2 gets agg id 1
> enslave eth3 to bond0 		//eth3 gets agg id 2
> 
> Fix this by making aggregator_identifier private to the bond.
> 
> Signed-off-by: Jiri Bohac <jbohac@suse.cz>

Looks good, and I think this matches what the original author of this
code probably intended.

Applied and queued up for -stable, thanks.

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Patch

diff --git a/drivers/net/bonding/bond_3ad.c b/drivers/net/bonding/bond_3ad.c
index 4ced594..dcf2ee8 100644
--- a/drivers/net/bonding/bond_3ad.c
+++ b/drivers/net/bonding/bond_3ad.c
@@ -1806,8 +1806,6 @@  void bond_3ad_initiate_agg_selection(struct bonding *bond, int timeout)
 	BOND_AD_INFO(bond).agg_select_timer = timeout;
 }
 
-static u16 aggregator_identifier;
-
 /**
  * bond_3ad_initialize - initialize a bond's 802.3ad parameters and structures
  * @bond: bonding struct to work on
@@ -1821,7 +1819,7 @@  void bond_3ad_initialize(struct bonding *bond, u16 tick_resolution)
 	if (MAC_ADDRESS_COMPARE(&(BOND_AD_INFO(bond).system.sys_mac_addr),
 				bond->dev->dev_addr)) {
 
-		aggregator_identifier = 0;
+		BOND_AD_INFO(bond).aggregator_identifier = 0;
 
 		BOND_AD_INFO(bond).system.sys_priority = 0xFFFF;
 		BOND_AD_INFO(bond).system.sys_mac_addr = *((struct mac_addr *)bond->dev->dev_addr);
@@ -1892,7 +1890,7 @@  int bond_3ad_bind_slave(struct slave *slave)
 		ad_initialize_agg(aggregator);
 
 		aggregator->aggregator_mac_address = *((struct mac_addr *)bond->dev->dev_addr);
-		aggregator->aggregator_identifier = (++aggregator_identifier);
+		aggregator->aggregator_identifier = ++BOND_AD_INFO(bond).aggregator_identifier;
 		aggregator->slave = slave;
 		aggregator->is_active = 0;
 		aggregator->num_of_ports = 0;
diff --git a/drivers/net/bonding/bond_3ad.h b/drivers/net/bonding/bond_3ad.h
index 5d91ad0..1f081c8 100644
--- a/drivers/net/bonding/bond_3ad.h
+++ b/drivers/net/bonding/bond_3ad.h
@@ -253,6 +253,7 @@  struct ad_system {
 struct ad_bond_info {
 	struct ad_system system;	    /* 802.3ad system structure */
 	u32 agg_select_timer;	    // Timer to select aggregator after all adapter's hand shakes
+	u16 aggregator_identifier;
 };
 
 struct ad_slave_info {