From: Jiri Pirko <j...@mellanox.com> For the TC clsact offload these days, some of HW drivers need to hold a magic ball. The reason is, with the first inserted rule inside HW they need to guess what fields will be used for the matching. If later on this guess proves to be wrong and user adds a filter with a different field to match, there's a problem. Mlxsw resolves it now with couple of patterns. Those try to cover as many match fields as possible. This aproach is far from optimal, both performance-wise and scale-wise. Also, there is a combination of filters that in certain order won't succeed.
Most of the time, when user inserts filters in chain, he knows right away how the filters are going to look like - what type and option will they have. For example, he knows that he will only insert filters of type flower matching destination IP address. He can specify a template that would cover all the filters in the chain. This patchset is providing the possibility to user to provide such template to kernel and propagate it all the way down to device drivers. See the examples below. Create dummy device with clsact first: # ip link add type dummy # tc qdisc add dev dummy0 clsact There is no template assigned by default: # tc chaintemplate show dev dummy0 ingress Add a template of type flower allowing to insert rules matching on last 2 bytes of destination mac address: # tc chaintemplate add dev dummy0 ingress proto ip flower dst_mac 00:00:00:00:00:00/00:00:00:00:FF:FF The template is now showed in the list: # tc chaintemplate show dev dummy0 ingress chaintemplate flower chain 0 dst_mac 00:00:00:00:00:00/00:00:00:00:ff:ff eth_type ipv4 Add another template, this time for chain number 22: # tc chaintemplate add dev dummy0 ingress proto ip chain 22 flower dst_ip 0.0.0.0/16 # tc chaintemplate show dev dummy0 ingress chaintemplate flower chain 0 dst_mac 00:00:00:00:00:00/00:00:00:00:ff:ff eth_type ipv4 chaintemplate flower chain 22 eth_type ipv4 dst_ip 0.0.0.0/16 Add a filter that fits the template: # tc filter add dev dummy0 ingress proto ip flower dst_mac aa:bb:cc:dd:ee:ff/00:00:00:00:00:0F action drop Addition of filters that does not fit the template would fail: # tc filter add dev dummy0 ingress proto ip flower dst_mac aa:11:22:33:44:55/00:00:00:FF:00:00 action drop Error: Mask does not fit the template. We have an error talking to the kernel, -1 # tc filter add dev dummy0 ingress proto ip flower dst_ip 10.0.0.1 action drop Error: Mask does not fit the template. We have an error talking to the kernel, -1 Additions of filters to chain 22: # tc filter add dev dummy0 ingress proto ip chain 22 flower dst_ip 10.0.0.1/8 action drop # tc filter add dev dummy0 ingress proto ip chain 22 flower dst_ip 10.0.0.1 action drop Error: Mask does not fit the template. We have an error talking to the kernel, -1 # tc filter add dev dummy0 ingress proto ip chain 22 flower dst_ip 10.0.0.1/24 action drop Error: Mask does not fit the template. We have an error talking to the kernel, -1 Removal of a template from non-empty chain would fail: # tc chaintemplate del dev dummy0 ingress Error: The chain is not empty, unable to delete template. We have an error talking to the kernel, -1 Once the chain is flushed, the template could be removed: # tc filter del dev dummy0 ingress # tc chaintemplate del dev dummy0 ingress --- v1->v2: - patch 5: - rebase on top of the reoffload pathset - patch 6: - remove leftover extack arg in fl_hw_create_tmplt() - rebase on top of the reoffload pathset - patch 9: - adjust to the userspace cmdline changes Jiri Pirko (9): net: sched: push ops lookup bits into tcf_proto_lookup_ops() net: sched: introduce chain templates net: sched: cls_flower: move key/mask dumping into a separate function net: sched: cls_flower: change fl_init_dissector to accept mask and dissector net: sched: cls_flower: implement chain templates net: sched: cls_flower: propagate chain teplate creation and destruction to drivers mlxsw: spectrum: Implement chain template hinting selftests: forwarding: move shblock tc support check to a separate helper selftests: forwarding: add tests for TC chain templates drivers/net/ethernet/mellanox/mlxsw/spectrum.c | 5 + drivers/net/ethernet/mellanox/mlxsw/spectrum.h | 12 +- drivers/net/ethernet/mellanox/mlxsw/spectrum_acl.c | 12 +- .../ethernet/mellanox/mlxsw/spectrum_acl_tcam.c | 25 +- .../net/ethernet/mellanox/mlxsw/spectrum_flower.c | 44 ++- include/net/pkt_cls.h | 2 + include/net/sch_generic.h | 14 +- include/uapi/linux/rtnetlink.h | 7 + net/sched/cls_api.c | 424 +++++++++++++++++++-- net/sched/cls_basic.c | 2 +- net/sched/cls_bpf.c | 3 +- net/sched/cls_cgroup.c | 2 +- net/sched/cls_flow.c | 3 +- net/sched/cls_flower.c | 250 +++++++++--- net/sched/cls_fw.c | 3 +- net/sched/cls_matchall.c | 3 +- net/sched/cls_route.c | 2 +- net/sched/cls_rsvp.h | 3 +- net/sched/cls_tcindex.c | 2 +- net/sched/cls_u32.c | 2 +- security/selinux/nlmsgtab.c | 2 +- tools/testing/selftests/net/forwarding/lib.sh | 12 + .../selftests/net/forwarding/tc_chaintemplates.sh | 160 ++++++++ .../selftests/net/forwarding/tc_shblocks.sh | 2 + 24 files changed, 900 insertions(+), 96 deletions(-) create mode 100755 tools/testing/selftests/net/forwarding/tc_chaintemplates.sh -- 2.14.4