linux-stable/net/bridge
Tobias Waldekranz f7cf972f93 net: bridge: disambiguate offload_fwd_mark
Before this change, four related - but distinct - concepts where named
offload_fwd_mark:

- skb->offload_fwd_mark: Set by the switchdev driver if the underlying
  hardware has already forwarded this frame to the other ports in the
  same hardware domain.

- nbp->offload_fwd_mark: An idetifier used to group ports that share
  the same hardware forwarding domain.

- br->offload_fwd_mark: Counter used to make sure that unique IDs are
  used in cases where a bridge contains ports from multiple hardware
  domains.

- skb->cb->offload_fwd_mark: The hardware domain on which the frame
  ingressed and was forwarded.

Introduce the term "hardware forwarding domain" ("hwdom") in the
bridge to denote a set of ports with the following property:

    If an skb with skb->offload_fwd_mark set, is received on a port
    belonging to hwdom N, that frame has already been forwarded to all
    other ports in hwdom N.

By decoupling the name from "offload_fwd_mark", we can extend the
term's definition in the future - e.g. to add constraints that
describe expected egress behavior - without overloading the meaning of
"offload_fwd_mark".

- nbp->offload_fwd_mark thus becomes nbp->hwdom.

- br->offload_fwd_mark becomes br->last_hwdom.

- skb->cb->offload_fwd_mark becomes skb->cb->src_hwdom. The slight
  change in naming here mandates a slight change in behavior of the
  nbp_switchdev_frame_mark() function. Previously, it only set this
  value in skb->cb for packets with skb->offload_fwd_mark true (ones
  which were forwarded in hardware). Whereas now we always track the
  incoming hwdom for all packets coming from a switchdev (even for the
  packets which weren't forwarded in hardware, such as STP BPDUs, IGMP
  reports etc). As all uses of skb->cb->offload_fwd_mark were already
  gated behind checks of skb->offload_fwd_mark, this will not introduce
  any functional change, but it paves the way for future changes where
  the ingressing hwdom must be known for frames coming from a switchdev
  regardless of whether they were forwarded in hardware or not
  (basically, if the skb comes from a switchdev, skb->cb->src_hwdom now
  always tracks which one).

  A typical example where this is relevant: the switchdev has a fixed
  configuration to trap STP BPDUs, but STP is not running on the bridge
  and the group_fwd_mask allows them to be forwarded. Say we have this
  setup:

        br0
       / | \
      /  |  \
  swp0 swp1 swp2

  A BPDU comes in on swp0 and is trapped to the CPU; the driver does not
  set skb->offload_fwd_mark. The bridge determines that the frame should
  be forwarded to swp{1,2}. It is imperative that forward offloading is
  _not_ allowed in this case, as the source hwdom is already "poisoned".

  Recording the source hwdom allows this case to be handled properly.

v2->v3: added code comments
v3->v6: none

Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Grygorii Strashko <grygorii.strashko@ti.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-22 00:26:23 -07:00
..
netfilter netfilter: allow to turn off xtables compat layer 2021-04-26 18:16:56 +02:00
br.c net: bridge: add vlan mcast snooping knob 2021-07-20 05:41:20 -07:00
br_arp_nd_proxy.c net: bridge: when suppression is enabled exclude RARP packets 2021-03-22 13:30:24 -07:00
br_cfm.c bridge: cfm: remove redundant return 2021-06-22 10:35:15 -07:00
br_cfm_netlink.c bridge: cfm: Netlink Notifications. 2020-10-29 18:39:44 -07:00
br_device.c net: bridge: add vlan mcast snooping knob 2021-07-20 05:41:20 -07:00
br_fdb.c net: bridge: allow br_fdb_replay to be called for the bridge device 2021-06-29 10:46:23 -07:00
br_forward.c net: bridge: multicast: use multicast contexts instead of bridge or port 2021-07-20 05:41:19 -07:00
br_if.c net: bridge: disambiguate offload_fwd_mark 2021-07-22 00:26:23 -07:00
br_input.c net: bridge: add vlan mcast snooping knob 2021-07-20 05:41:20 -07:00
br_ioctl.c net: bridge: delete duplicated words 2020-09-18 14:12:43 -07:00
br_mdb.c net: bridge: multicast: add context support for host-joined groups 2021-07-21 14:34:47 -07:00
br_mrp.c net: bridge: mrp: Update the Test frames for MRA 2021-06-28 15:46:10 -07:00
br_mrp_netlink.c bridge: mrp: Use hlist_head instead of list_head for mrp 2020-11-09 16:42:12 -08:00
br_mrp_switchdev.c bridge: mrp: Extend br_mrp_switchdev to detect better the errors 2021-02-16 14:47:46 -08:00
br_multicast.c net: bridge: multicast: add context support for host-joined groups 2021-07-21 14:34:47 -07:00
br_multicast_eht.c net: bridge: multicast: use multicast contexts instead of bridge or port 2021-07-20 05:41:19 -07:00
br_netfilter_hooks.c netfilter: bridge: reset skb->pkt_type after NF_INET_POST_ROUTING traversal 2020-11-28 11:46:51 -08:00
br_netfilter_ipv6.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2019-06-25 01:32:59 +02:00
br_netlink.c net: bridge: multicast: factor out bridge multicast context 2021-07-20 05:41:19 -07:00
br_netlink_tunnel.c net: bridge: notify on vlan tunnel changes done via the old api 2020-07-12 15:18:24 -07:00
br_nf_core.c net: add bool confirm_neigh parameter for dst_ops.update_pmtu 2019-12-24 22:28:54 -08:00
br_private.h net: bridge: disambiguate offload_fwd_mark 2021-07-22 00:26:23 -07:00
br_private_cfm.h bridge: cfm: Kernel space implementation of CFM. CCM frame RX added. 2020-10-29 18:39:43 -07:00
br_private_mcast_eht.h net: bridge: multicast: use multicast contexts instead of bridge or port 2021-07-20 05:41:19 -07:00
br_private_mrp.h net: bridge: mrp: Update the Test frames for MRA 2021-06-28 15:46:10 -07:00
br_private_stp.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
br_private_tunnel.h net: bridge: vlan options: add support for tunnel mapping set/del 2020-03-17 22:47:12 -07:00
br_stp.c net: bridge: constify variables in the replay helpers 2021-06-28 14:09:03 -07:00
br_stp_bpdu.c net: bridge: add STP xstats 2019-12-14 20:02:36 -08:00
br_stp_if.c net: remove newlines in NL_SET_ERR_MSG_MOD 2020-05-07 17:56:14 -07:00
br_stp_timer.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
br_switchdev.c net: bridge: disambiguate offload_fwd_mark 2021-07-22 00:26:23 -07:00
br_sysfs_br.c net: bridge: multicast: factor out bridge multicast context 2021-07-20 05:41:19 -07:00
br_sysfs_if.c net: bridge: multicast: factor out port multicast context 2021-07-20 05:41:19 -07:00
br_vlan.c net: bridge: vlan: add support for dumping global vlan options 2021-07-20 05:41:20 -07:00
br_vlan_options.c net: bridge: vlan: add mcast snooping control 2021-07-20 05:41:20 -07:00
br_vlan_tunnel.c net: bridge: fix vlan tunnel dst refcnt when egressing 2021-06-10 14:06:43 -07:00
Kconfig bridge: cfm: Add BRIDGE_CFM to Kconfig. 2020-10-29 18:39:43 -07:00
Makefile net: bridge: multicast: add EHT host handling functions 2021-01-22 19:39:56 -08:00