Files
fips/testing/nat/scripts
Johnathan Corgan 1c93fde672 Give each sender its own traversal offer allowance, and enforce the freshness bound at load
The incoming-offer semaphore was global with no per-sender accounting and
the permit was taken before any identity check, so one sender could hold
every slot and deny rendezvous to everyone else. Each sender now has its
own allowance with the global count kept as the outer bound. Note what
this does and does not do: it raises the cost from one keypair to a small
number of them, so a sender willing to spend throwaway identities can
still saturate the pool at unchanged total offer rate.

The signal freshness bound is only sound while the acceptance window
stays strictly inside the replay window, or an offer evicted from the
replay cache is still fresh enough to be accepted twice. The relation was
stated in a comment and enforced nowhere. Config validation now rejects
the bad combination at load, derived from the skew constant rather than a
literal, and checked regardless of whether the feature is enabled so that
turning it on later cannot surface an error at a surprising moment. The
NAT lab config generator produced a combination the new rule rejects and
is corrected in the same change.

The punch-target filter shipped with no test that would fail if it were
reverted. Loopback, link-local and multicast candidates and an oversized
list are now covered, and the cap assertion is tightened from a bound to
an equality. The private-range inclusion that LAN traversal depends on is
pinned as a healthy path so a blanket ban cannot pass.

Green: fmt, build, clippy and test --lib, 1533 passed.
2026-08-15 07:21:45 +00:00
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