linux-stable.git/net/bridge/br_input.c, branch v6.2 Linux kernel stable tree bridge: Add missing parentheses 2022-11-12T05:34:55+00:00 Ido Schimmel idosch@nvidia.com 2022-11-10T08:54:22+00:00 3e35f26d339718e155fa7cf5993a99924124a041 No changes in generated code. Reported-by: Petr Machata <petrm@nvidia.com> Reviewed-by: Petr Machata <petrm@nvidia.com> Signed-off-by: Ido Schimmel <idosch@nvidia.com> Link: https://lore.kernel.org/r/20221110085422.521059-1-idosch@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
No changes in generated code.

Reported-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Link: https://lore.kernel.org/r/20221110085422.521059-1-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
bridge: Add MAC Authentication Bypass (MAB) support 2022-11-04T03:46:32+00:00 Hans J. Schultz netdev@kapio-technology.com 2022-11-01T19:39:21+00:00 a35ec8e38cdd1766f29924ca391a01de20163931 Hosts that support 802.1X authentication are able to authenticate themselves by exchanging EAPOL frames with an authenticator (Ethernet bridge, in this case) and an authentication server. Access to the network is only granted by the authenticator to successfully authenticated hosts. The above is implemented in the bridge using the "locked" bridge port option. When enabled, link-local frames (e.g., EAPOL) can be locally received by the bridge, but all other frames are dropped unless the host is authenticated. That is, unless the user space control plane installed an FDB entry according to which the source address of the frame is located behind the locked ingress port. The entry can be dynamic, in which case learning needs to be enabled so that the entry will be refreshed by incoming traffic. There are deployments in which not all the devices connected to the authenticator (the bridge) support 802.1X. Such devices can include printers and cameras. One option to support such deployments is to unlock the bridge ports connecting these devices, but a slightly more secure option is to use MAB. When MAB is enabled, the MAC address of the connected device is used as the user name and password for the authentication. For MAB to work, the user space control plane needs to be notified about MAC addresses that are trying to gain access so that they will be compared against an allow list. This can be implemented via the regular learning process with the sole difference that learned FDB entries are installed with a new "locked" flag indicating that the entry cannot be used to authenticate the device. The flag cannot be set by user space, but user space can clear the flag by replacing the entry, thereby authenticating the device. Locked FDB entries implement the following semantics with regards to roaming, aging and forwarding: 1. Roaming: Locked FDB entries can roam to unlocked (authorized) ports, in which case the "locked" flag is cleared. FDB entries cannot roam to locked ports regardless of MAB being enabled or not. Therefore, locked FDB entries are only created if an FDB entry with the given {MAC, VID} does not already exist. This behavior prevents unauthenticated devices from disrupting traffic destined to already authenticated devices. 2. Aging: Locked FDB entries age and refresh by incoming traffic like regular entries. 3. Forwarding: Locked FDB entries forward traffic like regular entries. If user space detects an unauthorized MAC behind a locked port and wishes to prevent traffic with this MAC DA from reaching the host, it can do so using tc or a different mechanism. Enable the above behavior using a new bridge port option called "mab". It can only be enabled on a bridge port that is both locked and has learning enabled. Locked FDB entries are flushed from the port once MAB is disabled. A new option is added because there are pure 802.1X deployments that are not interested in notifications about locked FDB entries. Signed-off-by: Hans J. Schultz <netdev@kapio-technology.com> Signed-off-by: Ido Schimmel <idosch@nvidia.com> Acked-by: Nikolay Aleksandrov <razor@blackwall.org> Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
Hosts that support 802.1X authentication are able to authenticate
themselves by exchanging EAPOL frames with an authenticator (Ethernet
bridge, in this case) and an authentication server. Access to the
network is only granted by the authenticator to successfully
authenticated hosts.

The above is implemented in the bridge using the "locked" bridge port
option. When enabled, link-local frames (e.g., EAPOL) can be locally
received by the bridge, but all other frames are dropped unless the host
is authenticated. That is, unless the user space control plane installed
an FDB entry according to which the source address of the frame is
located behind the locked ingress port. The entry can be dynamic, in
which case learning needs to be enabled so that the entry will be
refreshed by incoming traffic.

There are deployments in which not all the devices connected to the
authenticator (the bridge) support 802.1X. Such devices can include
printers and cameras. One option to support such deployments is to
unlock the bridge ports connecting these devices, but a slightly more
secure option is to use MAB. When MAB is enabled, the MAC address of the
connected device is used as the user name and password for the
authentication.

For MAB to work, the user space control plane needs to be notified about
MAC addresses that are trying to gain access so that they will be
compared against an allow list. This can be implemented via the regular
learning process with the sole difference that learned FDB entries are
installed with a new "locked" flag indicating that the entry cannot be
used to authenticate the device. The flag cannot be set by user space,
but user space can clear the flag by replacing the entry, thereby
authenticating the device.

Locked FDB entries implement the following semantics with regards to
roaming, aging and forwarding:

1. Roaming: Locked FDB entries can roam to unlocked (authorized) ports,
   in which case the "locked" flag is cleared. FDB entries cannot roam
   to locked ports regardless of MAB being enabled or not. Therefore,
   locked FDB entries are only created if an FDB entry with the given {MAC,
   VID} does not already exist. This behavior prevents unauthenticated
   devices from disrupting traffic destined to already authenticated
   devices.

2. Aging: Locked FDB entries age and refresh by incoming traffic like
   regular entries.

3. Forwarding: Locked FDB entries forward traffic like regular entries.
   If user space detects an unauthorized MAC behind a locked port and
   wishes to prevent traffic with this MAC DA from reaching the host, it
   can do so using tc or a different mechanism.

Enable the above behavior using a new bridge port option called "mab".
It can only be enabled on a bridge port that is both locked and has
learning enabled. Locked FDB entries are flushed from the port once MAB
is disabled. A new option is added because there are pure 802.1X
deployments that are not interested in notifications about locked FDB
entries.

Signed-off-by: Hans J. Schultz <netdev@kapio-technology.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
net: bridge: Clear offload_fwd_mark when passing frame up bridge interface. 2022-05-19T07:20:44+00:00 Andrew Lunn andrew@lunn.ch 2022-05-18T00:58:40+00:00 fbb3abdf2223cd0dfc07de85fe5a43ba7f435bdf It is possible to stack bridges on top of each other. Consider the following which makes use of an Ethernet switch: br1 / \ / \ / \ br0.11 wlan0 | br0 / | \ p1 p2 p3 br0 is offloaded to the switch. Above br0 is a vlan interface, for vlan 11. This vlan interface is then a slave of br1. br1 also has a wireless interface as a slave. This setup trunks wireless lan traffic over the copper network inside a VLAN. A frame received on p1 which is passed up to the bridge has the skb->offload_fwd_mark flag set to true, indicating that the switch has dealt with forwarding the frame out ports p2 and p3 as needed. This flag instructs the software bridge it does not need to pass the frame back down again. However, the flag is not getting reset when the frame is passed upwards. As a result br1 sees the flag, wrongly interprets it, and fails to forward the frame to wlan0. When passing a frame upwards, clear the flag. This is the Rx equivalent of br_switchdev_frame_unmark() in br_dev_xmit(). Fixes: f1c2eddf4cb6 ("bridge: switchdev: Use an helper to clear forward mark") Signed-off-by: Andrew Lunn <andrew@lunn.ch> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Tested-by: Ido Schimmel <idosch@nvidia.com> Acked-by: Nikolay Aleksandrov <razor@blackwall.org> Link: https://lore.kernel.org/r/20220518005840.771575-1-andrew@lunn.ch Signed-off-by: Paolo Abeni <pabeni@redhat.com> 
It is possible to stack bridges on top of each other. Consider the
following which makes use of an Ethernet switch:

       br1
     /    \
    /      \
   /        \
 br0.11    wlan0
   |
   br0
 /  |  \
p1  p2  p3

br0 is offloaded to the switch. Above br0 is a vlan interface, for
vlan 11. This vlan interface is then a slave of br1. br1 also has a
wireless interface as a slave. This setup trunks wireless lan traffic
over the copper network inside a VLAN.

A frame received on p1 which is passed up to the bridge has the
skb->offload_fwd_mark flag set to true, indicating that the switch has
dealt with forwarding the frame out ports p2 and p3 as needed. This
flag instructs the software bridge it does not need to pass the frame
back down again. However, the flag is not getting reset when the frame
is passed upwards. As a result br1 sees the flag, wrongly interprets
it, and fails to forward the frame to wlan0.

When passing a frame upwards, clear the flag. This is the Rx
equivalent of br_switchdev_frame_unmark() in br_dev_xmit().

Fixes: f1c2eddf4cb6 ("bridge: switchdev: Use an helper to clear forward mark")
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Tested-by: Ido Schimmel <idosch@nvidia.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://lore.kernel.org/r/20220518005840.771575-1-andrew@lunn.ch
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
net: bridge: mst: Multiple Spanning Tree (MST) mode 2022-03-17T23:49:57+00:00 Tobias Waldekranz tobias@waldekranz.com 2022-03-16T15:08:43+00:00 ec7328b59176227216c461601c6bd0e922232a9b Allow the user to switch from the current per-VLAN STP mode to an MST mode. Up to this point, per-VLAN STP states where always isolated from each other. This is in contrast to the MSTP standard (802.1Q-2018, Clause 13.5), where VLANs are grouped into MST instances (MSTIs), and the state is managed on a per-MSTI level, rather that at the per-VLAN level. Perhaps due to the prevalence of the standard, many switching ASICs are built after the same model. Therefore, add a corresponding MST mode to the bridge, which we can later add offloading support for in a straight-forward way. For now, all VLANs are fixed to MSTI 0, also called the Common Spanning Tree (CST). That is, all VLANs will follow the port-global state. Upcoming changes will make this actually useful by allowing VLANs to be mapped to arbitrary MSTIs and allow individual MSTI states to be changed. Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com> Acked-by: Nikolay Aleksandrov <razor@blackwall.org> Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
Allow the user to switch from the current per-VLAN STP mode to an MST
mode.

Up to this point, per-VLAN STP states where always isolated from each
other. This is in contrast to the MSTP standard (802.1Q-2018, Clause
13.5), where VLANs are grouped into MST instances (MSTIs), and the
state is managed on a per-MSTI level, rather that at the per-VLAN
level.

Perhaps due to the prevalence of the standard, many switching ASICs
are built after the same model. Therefore, add a corresponding MST
mode to the bridge, which we can later add offloading support for in a
straight-forward way.

For now, all VLANs are fixed to MSTI 0, also called the Common
Spanning Tree (CST). That is, all VLANs will follow the port-global
state.

Upcoming changes will make this actually useful by allowing VLANs to
be mapped to arbitrary MSTIs and allow individual MSTI states to be
changed.

Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
net: bridge: Add support for bridge port in locked mode 2022-02-23T12:52:34+00:00 Hans Schultz schultz.hans@gmail.com 2022-02-23T10:16:46+00:00 a21d9a670d81103db7f788de1a4a4a6e4b891a0b In a 802.1X scenario, clients connected to a bridge port shall not be allowed to have traffic forwarded until fully authenticated. A static fdb entry of the clients MAC address for the bridge port unlocks the client and allows bidirectional communication. This scenario is facilitated with setting the bridge port in locked mode, which is also supported by various switchcore chipsets. Signed-off-by: Hans Schultz <schultz.hans+netdev@gmail.com> Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
In a 802.1X scenario, clients connected to a bridge port shall not
be allowed to have traffic forwarded until fully authenticated.
A static fdb entry of the clients MAC address for the bridge port
unlocks the client and allows bidirectional communication.

This scenario is facilitated with setting the bridge port in locked
mode, which is also supported by various switchcore chipsets.

Signed-off-by: Hans Schultz <schultz.hans+netdev@gmail.com>
Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: bridge: change return type of br_handle_ingress_vlan_tunnel 2021-08-24T23:51:09+00:00 Kangmin Park l4stpr0gr4m@gmail.com 2021-08-23T10:21:18+00:00 a37c5c26693eadb3aa4101d8fe955e40d206b386 br_handle_ingress_vlan_tunnel() is only referenced in br_handle_frame(). If br_handle_ingress_vlan_tunnel() is called and return non-zero value, goto drop in br_handle_frame(). But, br_handle_ingress_vlan_tunnel() always return 0. So, the routines that check the return value and goto drop has no meaning. Therefore, change return type of br_handle_ingress_vlan_tunnel() to void and remove if statement of br_handle_frame(). Signed-off-by: Kangmin Park <l4stpr0gr4m@gmail.com> Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com> Link: https://lore.kernel.org/r/20210823102118.17966-1-l4stpr0gr4m@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
br_handle_ingress_vlan_tunnel() is only referenced in
br_handle_frame(). If br_handle_ingress_vlan_tunnel() is called and
return non-zero value, goto drop in br_handle_frame().

But, br_handle_ingress_vlan_tunnel() always return 0. So, the
routines that check the return value and goto drop has no meaning.

Therefore, change return type of br_handle_ingress_vlan_tunnel() to
void and remove if statement of br_handle_frame().

Signed-off-by: Kangmin Park <l4stpr0gr4m@gmail.com>
Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Link: https://lore.kernel.org/r/20210823102118.17966-1-l4stpr0gr4m@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
net: bridge: add vlan mcast snooping knob 2021-07-20T12:41:20+00:00 Nikolay Aleksandrov nikolay@nvidia.com 2021-07-19T17:06:28+00:00 f4b7002a7076f025dce59647a77c8251175d2b34 Add a global knob that controls if vlan multicast snooping is enabled. The proper contexts (vlan or bridge-wide) will be chosen based on the knob when processing packets and changing bridge device state. Note that vlans have their individual mcast snooping enabled by default, but this knob is needed to turn on bridge vlan snooping. It is disabled by default. To enable the knob vlan filtering must also be enabled, it doesn't make sense to have vlan mcast snooping without vlan filtering since that would lead to inconsistencies. Disabling vlan filtering will also automatically disable vlan mcast snooping. Signed-off-by: Nikolay Aleksandrov <nikolay@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Add a global knob that controls if vlan multicast snooping is enabled.
The proper contexts (vlan or bridge-wide) will be chosen based on the knob
when processing packets and changing bridge device state. Note that
vlans have their individual mcast snooping enabled by default, but this
knob is needed to turn on bridge vlan snooping. It is disabled by
default. To enable the knob vlan filtering must also be enabled, it
doesn't make sense to have vlan mcast snooping without vlan filtering
since that would lead to inconsistencies. Disabling vlan filtering will
also automatically disable vlan mcast snooping.

Signed-off-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: bridge: multicast: use multicast contexts instead of bridge or port 2021-07-20T12:41:19+00:00 Nikolay Aleksandrov nikolay@nvidia.com 2021-07-19T17:06:25+00:00 adc47037a7d5c8f89ca428bd840c83ab7b62730c Pass multicast context pointers to multicast functions instead of bridge/port. This would make it easier later to switch these contexts to their per-vlan versions. The patch is basically search and replace, no functional changes. Signed-off-by: Nikolay Aleksandrov <nikolay@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Pass multicast context pointers to multicast functions instead of bridge/port.
This would make it easier later to switch these contexts to their per-vlan
versions. The patch is basically search and replace, no functional changes.

Signed-off-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: bridge: mcast: prepare is-router function for mcast router split 2021-05-13T21:04:31+00:00 Linus Lüssing linus.luessing@c0d3.blue 2021-05-13T13:20:47+00:00 1a3065a26807b4cdd65d3b696ddb18385610f7da In preparation for the upcoming split of multicast router state into their IPv4 and IPv6 variants make br_multicast_is_router() protocol family aware. Note that for now br_ip6_multicast_is_router() uses the currently still common ip4_mc_router_timer for now. It will be renamed to ip6_mc_router_timer later when the split is performed. While at it also renames the "1" and "2" constants in br_multicast_is_router() to the MDB_RTR_TYPE_TEMP_QUERY and MDB_RTR_TYPE_PERM enums. Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue> Signed-off-by: David S. Miller <davem@davemloft.net> 
In preparation for the upcoming split of multicast router state into
their IPv4 and IPv6 variants make br_multicast_is_router() protocol
family aware.

Note that for now br_ip6_multicast_is_router() uses the currently still
common ip4_mc_router_timer for now. It will be renamed to
ip6_mc_router_timer later when the split is performed.

While at it also renames the "1" and "2" constants in
br_multicast_is_router() to the MDB_RTR_TYPE_TEMP_QUERY and
MDB_RTR_TYPE_PERM enums.

Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: bridge: Fix fall-through warnings for Clang 2021-03-10T20:45:15+00:00 Gustavo A. R. Silva gustavoars@kernel.org 2021-03-10T05:41:15+00:00 ecd1c6a51fcc0389d0dd3e3ea70edab3520f487d In preparation to enable -Wimplicit-fallthrough for Clang, fix a warning by explicitly adding a break statement instead of letting the code fall through to the next case. Link: https://github.com/KSPP/linux/issues/115 Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net> 
In preparation to enable -Wimplicit-fallthrough for Clang, fix a warning
by explicitly adding a break statement instead of letting the code fall
through to the next case.

Link: https://github.com/KSPP/linux/issues/115
Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>