selftests: Add tests for mirroring to gretap

This suite tests GRE-encapsulated mirroring. The general topology that most of the tests use is as follows, but each test defines details of the topology based on its needs, and some tests actually use a somewhat different topology.

+---------------------+                      +---------------------+
| H1                  |                      |                  H2 |
|     + $h1           |                      |           $h2 +     |
+-----|---------------+                      +---------------|-----+
      |                                                      |
+-----|------------------------------------------------------|-----+
| SW  o---> mirror                                           |     |
| +---|------------------------------------------------------|---+ |
| |   + $swp1               BR                         $swp2 +   | |
| +--------------------------------------------------------------+ |
|                                                                  |
|     + $swp3          + gt6 (ip6gretap)    + gt4 (gretap)         |
+-----|----------------:--------------------:----------------------+
      |                :                    :
+-----|----------------:--------------------:----------------------+
|     + $h3            + h3-gt6(ip6gretap)  + h3-gt4 (gretap)      |
| H3                                                               |
+------------------------------------------------------------------+

The following axes of configuration space are tested:

- ingress and egress mirroring
- mirroring triggered by matchall and flower
- mirroring to ipgretap and ip6gretap
- remote tunnel reachable directly or through a next-hop route
- skip_sw as well as skip_hw configurations

Apart from basic tests with the above mentioned features, the following tests are included:

- handling of changes to neighbors pertinent to routing decisions in mirrored underlay
- handling of configuration changes at the mirrored-to tunnel (endpoint addresses, upness)

A suite of mlxsw-specific tests will be part of a separate submission through linux-mlxsw patch queue.

Petr Machata (7):
selftests: forwarding: Add libs for gretap mirror testing
selftests: forwarding: Add test for mirror to gretap
selftests: forwarding: Test gretap mirror with next-hop remote
selftests: forwarding: Test mirror to gretap w/ bound dev
selftests: forwarding: Test flower mirror to gretap
selftests: forwarding: Test neighbor updates when mirroring to gretap
selftests: forwarding: Test changes in mirror-to-gretap

 tools/testing/selftests/net/forwarding/lib.sh      |  96 ++++++++++
 .../testing/selftests/net/forwarding/mirror_gre.sh | 139 ++++++++++++++
 .../selftests/net/forwarding/mirror_gre_bound.sh   | 213 +++++++++++++++++++++
 .../selftests/net/forwarding/mirror_gre_changes.sh | 194 +++++++++++++++++++
 .../selftests/net/forwarding/mirror_gre_flower.sh  | 116 +++++++++++
 .../selftests/net/forwarding/mirror_gre_lib.sh     |  85 ++++++++
 .../selftests/net/forwarding/mirror_gre_neigh.sh   | 101 ++++++++++
 .../selftests/net/forwarding/mirror_gre_nh.sh      | 117 +++++++++++
 .../net/forwarding/mirror_gre_topo_lib.sh          | 129 +++++++++++++
 .../testing/selftests/net/forwarding/mirror_lib.sh |  40 ++++
 10 files changed, 1230 insertions(+)
 create mode 100755 tools/testing/selftests/net/forwarding/mirror_gre.sh
 create mode 100755 tools/testing/selftests/net/forwarding/mirror_gre_bound.sh
 create mode 100755 tools/testing/selftests/net/forwarding/mirror_gre_changes.sh
 create mode 100755 tools/testing/selftests/net/forwarding/mirror_gre_flower.sh
 create mode 100644 tools/testing/selftests/net/forwarding/mirror_gre_lib.sh
 create mode 100755 tools/testing/selftests/net/forwarding/mirror_gre_neigh.sh
 create mode 100755 tools/testing/selftests/net/forwarding/mirror_gre_nh.sh
 create mode 100644 tools/testing/selftests/net/forwarding/mirror_gre_topo_lib.sh
 create mode 100644 tools/testing/selftests/net/forwarding/mirror_lib.sh

2.4.11