Re: [PATCH next v4 5/6] bonding: Allow userspace to set actors' macaddr in an AD-system.

[Nikolay Aleksandrov <nikolay@redhat.com>]

On 02/18/2015 08:17 AM, Mahesh Bandewar wrote:
> In an AD system, the communication between actor and partner is the
> business between these two entities. In the current setup anyone on the
> same L2 can "guess" the LACPDU contents and then possibly send the
> spoofed LACPDUs and trick the partner causing connectivity issues for
> the AD system. This patch allows to use a random mac-address obscuring
> it's identity making it harder for someone in the L2 is do the same thing.
> 
> This patch allows user-space to choose the mac-address for the AD-system.
> This mac-address can not be NULL or a Multicast. If the mac-address is set
> from user-space; kernel will honor it and will not overwrite it. In the
> absence (value from user space); the logic will default to using the
> masters' mac as the mac-address for the AD-system.
> 
> It can be set using example code below -
> 
>    # modprobe bonding mode=4
>    # sys_mac_addr=$(printf '%02x:%02x:%02x:%02x:%02x:%02x' \
>                     $(( (RANDOM & 0xFE) | 0x02 )) \
>                     $(( RANDOM & 0xFF )) \
>                     $(( RANDOM & 0xFF )) \
>                     $(( RANDOM & 0xFF )) \
>                     $(( RANDOM & 0xFF )) \
>                     $(( RANDOM & 0xFF )))
>    # echo $sys_mac_addr > /sys/class/net/bond0/bonding/ad_actor_system
>    # echo +eth1 > /sys/class/net/bond0/bonding/slaves
>    ...
>    # ip link set bond0 up
> 
> Signed-off-by: Mahesh Bandewar <maheshb@google.com>
> ---
> v1:
>   Initial version
> v2:
>   Renamed ad_actor_system_mac_address to ad_actor_system
> v3:
>   Fixed commit message.
> v4:
>   Rebase
> 
>  Documentation/networking/bonding.txt | 12 ++++++++++++
>  drivers/net/bonding/bond_3ad.c       |  7 ++++++-
>  drivers/net/bonding/bond_main.c      |  1 +
>  drivers/net/bonding/bond_options.c   | 29 +++++++++++++++++++++++++++++
>  drivers/net/bonding/bond_procfs.c    |  6 ++++++
>  drivers/net/bonding/bond_sysfs.c     | 15 +++++++++++++++
>  include/net/bond_options.h           |  1 +
>  include/net/bonding.h                |  1 +
>  8 files changed, 71 insertions(+), 1 deletion(-)
> 
> diff --git a/Documentation/networking/bonding.txt b/Documentation/networking/bonding.txt
> index f19d888651b8..f0d93c58cdb0 100644
> --- a/Documentation/networking/bonding.txt
> +++ b/Documentation/networking/bonding.txt
> @@ -187,6 +187,18 @@ ad_actor_sys_prio
>  	This paramter has effect only in 802.3ad mode and is available through
>  	SysFs interface.
>  
> +ad_actor_system
> +
> +	In an AD system, this specifies the mac-address for the actor in
> +	protocol packet exchanges (LACPDUs). The value cannot be NULL or
> +	multicast. It is preferred to have the local-admin bit set for this
> +	mac but driver does not enforce it. If the value is not given then
> +	system defaults to using the masters' mac address as actors' system
> +	address.
> +
> +	This paramter has effect only in 802.3ad mode and is available through
s/paramter/parameter/

> +	SysFs interface.
> +