Commit 784b58a3 authored by Bernhard Thaler's avatar Bernhard Thaler Committed by David S. Miller

bridge: change BR_GROUPFWD_RESTRICTED to allow forwarding of LLDP frames

BR_GROUPFWD_RESTRICTED bitmask restricts users from setting values to
/sys/class/net/brX/bridge/group_fwd_mask that allow forwarding of
some IEEE 802.1D Table 7-10 Reserved addresses:

	(MAC Control) 802.3		01-80-C2-00-00-01
	(Link Aggregation) 802.3	01-80-C2-00-00-02
	802.1AB LLDP			01-80-C2-00-00-0E

Change BR_GROUPFWD_RESTRICTED to allow to forward LLDP frames and document
group_fwd_mask.

e.g.
   echo 16384 > /sys/class/net/brX/bridge/group_fwd_mask
allows to forward LLDP frames.

This may be needed for bridge setups used for network troubleshooting or
any other scenario where forwarding of LLDP frames is desired (e.g. bridge
connecting a virtual machine to real switch transmitting LLDP frames that
virtual machine needs to receive).

Tested on a simple bridge setup with two interfaces and host transmitting
LLDP frames on one side of this bridge (used lldpd). Setting group_fwd_mask
as described above lets LLDP frames traverse bridge.
Signed-off-by: default avatarBernhard Thaler <bernhard.thaler@wvnet.at>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent cd8ae852
...@@ -39,6 +39,25 @@ Description: ...@@ -39,6 +39,25 @@ Description:
Format is a string, e.g: 00:11:22:33:44:55 for an Ethernet MAC Format is a string, e.g: 00:11:22:33:44:55 for an Ethernet MAC
address. address.
What: /sys/class/net/<bridge iface>/bridge/group_fwd_mask
Date: January 2012
KernelVersion: 3.2
Contact: netdev@vger.kernel.org
Description:
Bitmask to allow forwarding of link local frames with address
01-80-C2-00-00-0X on a bridge device. Only values that set bits
not matching BR_GROUPFWD_RESTRICTED in net/bridge/br_private.h
allowed.
Default value 0 does not forward any link local frames.
Restricted bits:
0: 01-80-C2-00-00-00 Bridge Group Address used for STP
1: 01-80-C2-00-00-01 (MAC Control) 802.3 used for MAC PAUSE
2: 01-80-C2-00-00-02 (Link Aggregation) 802.3ad
Any values not setting these bits can be used. Take special
care when forwarding control frames e.g. 802.1X-PAE or LLDP.
What: /sys/class/net/<iface>/broadcast What: /sys/class/net/<iface>/broadcast
Date: April 2005 Date: April 2005
KernelVersion: 2.6.12 KernelVersion: 2.6.12
......
...@@ -33,8 +33,8 @@ ...@@ -33,8 +33,8 @@
/* Control of forwarding link local multicast */ /* Control of forwarding link local multicast */
#define BR_GROUPFWD_DEFAULT 0 #define BR_GROUPFWD_DEFAULT 0
/* Don't allow forwarding control protocols like STP and LLDP */ /* Don't allow forwarding of control protocols like STP, MAC PAUSE and LACP */
#define BR_GROUPFWD_RESTRICTED 0x4007u #define BR_GROUPFWD_RESTRICTED 0x0007u
/* The Nearest Customer Bridge Group Address, 01-80-C2-00-00-[00,0B,0C,0D,0F] */ /* The Nearest Customer Bridge Group Address, 01-80-C2-00-00-[00,0B,0C,0D,0F] */
#define BR_GROUPFWD_8021AD 0xB801u #define BR_GROUPFWD_8021AD 0xB801u
......
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