1a432018c0
Add the 'TCA_FLOWER_L2_MISS' netlink attribute that allows user space to
match on packets that encountered a layer 2 miss. The miss indication is
set as metadata in the tc skb extension by the bridge driver upon FDB or
MDB lookup miss and dissected by the flow dissector to the
'FLOW_DISSECTOR_KEY_META' key.
The use of this skb extension is guarded by the 'tc_skb_ext_tc' static
key. As such, enable / disable this key when filters that match on layer
2 miss are added / deleted.
Tested:
# cat tc_skb_ext_tc.py
#!/usr/bin/env -S drgn -s vmlinux
refcount = prog["tc_skb_ext_tc"].key.enabled.counter.value_()
print(f"tc_skb_ext_tc reference count is {refcount}")
# ./tc_skb_ext_tc.py
tc_skb_ext_tc reference count is 0
# tc filter add dev swp1 egress proto all handle 101 pref 1 flower src_mac 00:11:22:33:44:55 action drop
# tc filter add dev swp1 egress proto all handle 102 pref 2 flower src_mac 00:11:22:33:44:55 l2_miss true action drop
# tc filter add dev swp1 egress proto all handle 103 pref 3 flower src_mac 00:11:22:33:44:55 l2_miss false action drop
# ./tc_skb_ext_tc.py
tc_skb_ext_tc reference count is 2
# tc filter replace dev swp1 egress proto all handle 102 pref 2 flower src_mac 00:01:02:03:04:05 l2_miss false action drop
# ./tc_skb_ext_tc.py
tc_skb_ext_tc reference count is 2
# tc filter del dev swp1 egress proto all handle 103 pref 3 flower
# tc filter del dev swp1 egress proto all handle 102 pref 2 flower
# tc filter del dev swp1 egress proto all handle 101 pref 1 flower
# ./tc_skb_ext_tc.py
tc_skb_ext_tc reference count is 0
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.