In commit 6de6e46d27 ("cls_flower: Fix inability to match GRE/IPIP
packets"), cls_flower was fixed to match an outer packet of a tunneled
packet as would be expected, rather than dissecting to the inner packet and
matching on that.
This fix uncovered several issues in packet matching in mirroring
selftests:
- in mirror_gre_bridge_1d_vlan.sh and mirror_gre_vlan_bridge_1q.sh, the
vlan_ethtype match is copied around as "ip", even as some of the tests
are running over ip6gretap. This is fixed by using an "ipv6" for
vlan_ethtype in the ip6gretap tests.
- in mirror_gre_changes.sh, a filter to count GRE packets is set up to
match TTL of 50. This used to trigger in the offloaded datapath, where
the envelope TTL was matched, but not in the software datapath, which
considered TTL of the inner packet. Now that both match consistently, all
the packets were double-counted. This is fixed by marking the filter as
skip_hw, leaving only the SW datapath component active.
Fixes: 6de6e46d27 ("cls_flower: Fix inability to match GRE/IPIP packets")
Signed-off-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Motivation
==========
One of the nice things about network namespaces is that they allow one
to easily create and test complex environments.
Unfortunately, these namespaces can not be used with actual switching
ASICs, as their ports can not be migrated to other network namespaces
(NETIF_F_NETNS_LOCAL) and most of them probably do not support the
L1-separation provided by namespaces.
However, a similar kind of flexibility can be achieved by using VRFs and
by looping the switch ports together. For example:
br0
+
vrf-h1 | vrf-h2
+ +---+----+ +
| | | |
192.0.2.1/24 + + + + 192.0.2.2/24
swp1 swp2 swp3 swp4
+ + + +
| | | |
+--------+ +--------+
The VRFs act as lightweight namespaces representing hosts connected to
the switch.
This approach for testing switch ASICs has several advantages over the
traditional method that requires multiple physical machines, to name a
few:
1. Only the device under test (DUT) is being tested without noise from
other system.
2. Ability to easily provision complex topologies. Testing bridging
between 4-ports LAGs or 8-way ECMP requires many physical links that are
not always available. With the VRF-based approach one merely needs to
loopback more ports.
These tests are written with switch ASICs in mind, but they can be run
on any Linux box using veth pairs to emulate physical loopbacks.
Guidelines for Writing Tests
============================
o Where possible, reuse an existing topology for different tests instead
of recreating the same topology.
o Tests that use anything but the most trivial topologies should include
an ASCII art showing the topology.
o Where possible, IPv6 and IPv4 addresses shall conform to RFC 3849 and
RFC 5737, respectively.
o Where possible, tests shall be written so that they can be reused by
multiple topologies and added to lib.sh.
o Checks shall be added to lib.sh for any external dependencies.
o Code shall be checked using ShellCheck [1] prior to submission.
1. https://www.shellcheck.net/
af0a51113c