mrambossekandClaude Opus 5
5b5a54db7d
fmr keeps .151/::151 for measurement. Their diagnostic value is entirely in their listening state being known: a TLS handshake that completes on a port nothing listens on proves interception, with no competing explanation. One stray bind turns that proof into a shrug, and nothing about the failure is visible — the run still says the network is clean. CheckReserved refuses to start when a listener would take one. Wildcards are refused outright, because that is how this actually happens: every listener defaults to ":port" and the next one added gets copied from an existing default, claiming every address without anyone deciding to. Reserved is not silent, though. The first version of the guard would have refused the live config's UDP and canary-DNS binds on .151, which are deliberate — as is STUN's RFC 5780 alternate. Reserving an address and then forbidding the measurements that need it defeats the purpose. The rule is narrower: no services, and never ports 80 or 443. The adb-beacon receiver was wildcard-bound to 0.0.0.0:443, holding port 443 on every IPv4 address including the reserved one, so the IPv4 interception test had been compromised for as long as it had run. It is disabled; restore with systemctl enable --now echolot-adb-beacon. This also marks the guard's limit: it governs this server's listeners, and a process outside its config can still pollute a reserved address. The admin UI and ACME responder were single-address, which is why the UI could only live on ::2 and why the server was reachable over IPv6 alone — the thing that made it look nonexistent from a phone without working IPv6. Both now take address lists like every other listener. Verified from outside: .150/::150/::2 answer on 443 with a valid cert for fmr.echo-lot.app, .151/::151 are closed on 80 and 443, and canary DNS is still up on .151. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Echolot
Free software for detecting and debugging local network issues from an Android phone — built for people who actually know what a neighbor table is.
Most "wifi analyzer" apps show you signal bars. Echolot aims at the layer where home and office networks actually break: duplicate DHCP servers, broken IPv6 RAs, MTU black holes, NAT64 weirdness, multicast that dies at the AP, DNS that answers differently than it should. It records what it observed, separates observation from interpretation, and exports the whole run so you can argue with it later.
Status: pre-release. The capability prober runs on real hardware; the production app and the probe server are not built yet.
Repository layout
docs/ design docs — the contract for everything below
echolot-prober/ capability prober: validates the no-root feasibility matrix on real devices
The Go probe server and the production app land here as siblings.
Design docs
The three specs are draft-complete and reviewed; treat them as the contract.
| Doc | What it defines |
|---|---|
| docs/feature-catalog-and-feasibility.md | Full feature list + the no-root feasibility matrix |
| docs/measurement-schema.md | Archived/exportable measurement JSON (observation vs finding, two-clock rule, anonymization) |
| docs/probe-protocol.md | Client↔server wire protocol (pinned TLS control plane, binary UDP data plane, STUN, canary DNS) |
| docs/build-status.md | Running log of decisions and next steps |
Privilege tiers
Every result records which tier produced it:
app— no root, no special setup. The bulk of the functionality.shizuku— ADB-shell privileges via wireless pairing, no root. Shipped in v1.root— future optional module.
Licensing
| Part | License | Why |
|---|---|---|
| All code (app, prober, server) | GPL-3.0-or-later | The value here is the platform-API research; copyleft keeps derivative apps free |
docs/ (the specs) |
CC-BY-4.0 | A wire protocol and a measurement format should be implementable by anyone, without license anxiety |
Full texts: LICENSE (GPLv3) and docs/LICENSE (CC BY 4.0).
Sources carry SPDX-License-Identifier headers.
If you want to build a compatible server or client, the protocol and schema docs are deliberately permissive — go ahead.
Building
See echolot-prober/README.md. Short version, from echolot-prober/:
echo "sdk.dir=/path/to/Android/sdk" > local.properties
./gradlew :app:assembleDebug