Types 0x03/0x04/0x05 land with a bounded columnar train buffer (head kept, truncation declared) and grant-free multi-part reports - a report row is smaller than the packet it answers, so $3.4 holds without a grant. The read loop now collects TTL/TOS cmsgs on Linux, replacing the 0xFF stubs in the observation block with what the kernel saw; downtrain gained a dscp parameter, so DSCP survival is measurable in both directions. Rate limiting ($2.5) exists now: per-credential AND per-source buckets, 429 on the control plane, silent drop on the data plane after the HMAC gate and before the replay window. UDP ceilings default above the largest legitimate run - a limit that clips a real measurement produces a confidently wrong number. Every granted packet carries its action_id at payload[8:16]; overlapping actions were unattributable before. Canary DNS logs now honor the stated 24h privacy default. /admin/enroll-tokens answers the spec's JSON shape. protocol_version 1.0.1 (additive). 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