[ipsec,0/2] xfrm: Fix bugs in stacked XFRM-I tunnels

Message

Benedict Wong Aug. 10, 2022, 6:22 p.m. UTC

This patch set fixes bugs that prevent stacked IPsec tunnels (via XFRM
interfaces) from receiving packets properly. The apparent cause of the
issues is that the inner tunnel’s policy checks fail to validate the
outer tunnel’s secpath entries (since it no longer has a reference to
the outer tunnel policies, and each call validates ALL secpath entries)
prior to verifying the inner tunnel’s. This patch set fixes this by
caching the list of verified secpath entries, and skipping them upon
future validation runs.

PATCH 1/2 Ensures that policies for nested tunnel mode transforms are
checked before additional decapsulation. This ensures that entries in
the secpath are verified while the context (intermediate IP addresses,
marks, etc) can be appropriately matched.

PATCH 2/2 Skips template matching for previously verified entries in
the secpath. This ensures that each tunnel is responsible for
incrementally verifying the secpath entries associated with it.