[PATCH net-next v2 0/4] nexthop: Refactor and fix nexthop selection for multipath routes

[Benjamin Poirier <bpoirier@nvidia.com>]

In order to select a nexthop for multipath routes, fib_select_multipath()
is used with legacy nexthops and nexthop_select_path_hthr() is used with
nexthop objects. Those two functions perform a validity test on the
neighbor related to each nexthop but their logic is structured differently.
This causes a divergence in behavior and nexthop_select_path_hthr() may
return a nexthop that failed the neighbor validity test even if there was
one that passed.

Refactor nexthop_select_path_hthr() to make it more similar to
fib_select_multipath() and fix the problem mentioned above.

v2:
Removed unnecessary "first" variable in "nexthop: Do not return invalid
nexthop object during multipath selection".

v1:
https://lore.kernel.org/netdev/20230529201914.69828-1-bpoirier@nvidia.com/

---
Benjamin Poirier (4):
      nexthop: Factor out hash threshold fdb nexthop selection
      nexthop: Factor out neighbor validity check
      nexthop: Do not return invalid nexthop object during multipath selection
      selftests: net: Add test cases for nexthop groups with invalid neighbors

 net/ipv4/nexthop.c                          |  61 +++++++++----
 tools/testing/selftests/net/fib_nexthops.sh | 129 ++++++++++++++++++++++++++++
 2 files changed, 171 insertions(+), 19 deletions(-)
---
base-commit: 36395b2efe905650cd179d67411ffee3b770268b
change-id: 20230719-nh_select-0303d55a1fb0

Best regards,
-- 
Benjamin Poirier <bpoirier@nvidia.com>