# AGENTS.md

KLALB ("KLALB Decentralized SRv6 Network") — Java load-balancing/tunnel system that merges multiple WAN links into one virtual IPv6/SRv6 network. Version constant lives in `src/org/kne/cloud/network/klalb/CONST.java`. Protocol specs and manuals are the Chinese `.docx` files in the repo root.

## Build & run

No Maven/Gradle. Plain Eclipse/IntelliJ project: dependencies are vendored jars in `lib/`, output goes to `bin/` (gitignored). When adding a jar, update **both** `.classpath` and `KLALB.iml`.

Compile (`javac` is NOT on PATH — use the full JDK path; `-encoding UTF-8` is mandatory because sources contain Chinese text):

```powershell
& "C:\Program Files\Zulu\zulu-25\bin\javac.exe" -encoding UTF-8 -cp "lib/*" -d bin (Get-ChildItem -Recurse src -Filter *.java | ForEach-Object FullName)
```

Warnings about `ThreadTool` varargs / deprecated `finalize` are pre-existing and expected — success = exit code 0. After recompiling, restart the running app (IDE-debugged JVMs keep old classes).

Run from the repo root — CWD matters:
- reads `klalb-config.json` from CWD
- loads native libs from CWD: `tuntap4j.dll/.so/.dylib`, `wintun.dll`, `fastcopy.dll` (TUN device support)
- classpath must include `src` as well as `bin`: i18n bundles (`/klalb_*.properties`) and images (`/assets/*`) are classpath resources that Eclipse copies to `bin` but manual `javac` does not

```powershell
java --enable-native-access=ALL-UNNAMED "--add-opens=java.base/jdk.internal.misc=ALL-UNNAMED" -cp "bin;src;lib/*" org.kne.cloud.network.klalb.KLALBMain
```

IDE metadata targets JDK 26 (`jdk-26.0.1`); the tree also compiles cleanly on JDK 25. `.classpath` now references the standard container `JavaSE-25` — an execution-environment spec that any JDK ≥25 satisfies, so it works unchanged on JDK 26 machines too (the original named `jdk-26.0.1` VM broke VS Code import on machines without it). `.vscode/settings.json` maps `JavaSE-25` to the locally installed Adoptium JDK; register every installed JDK there when adding another one. Keep compiler compliance ≤25 (`.settings` pins 19) so both JDKs stay usable.

Runtime gotchas (all verified):
- On JDK 25, `KNEOptimize.jar`'s `FastLib` reflects into `jdk.internal.misc.Unsafe`; without the two JVM flags above it throws `InaccessibleObjectException` at startup (app still runs).
- Creating the SRv6 TUN adapter (`WintunCreateAdapter`) requires an elevated shell; without admin rights it logs "创建虚拟网卡失败" and continues with only the `inLoopBack` interface — links/bridges still work.
- To disable TUN creation completely (e.g. for non-admin UI/routing testing), set `"enableTUN": false` in `klalb-config.json` or toggle off "启用 TUN 虚拟网卡" in GUI/Web settings.
- Routing broadcast (`RouterInfo`) transmits `deviceName`, which topology and node overview panels display. `deviceDescription` is NOT broadcast — it only leaves the node in full node-info query responses (see srv6 API below); `ExtraRoutes` remain local controller configs.

## Verification

No test suite, no CI. Classes named `*Test*` (`nathole/`, `ntp/`) are manual `main()` harnesses requiring real network peers. Practical check = compile succeeds + app launches.

## Architecture

- Entrypoint `org.kne.cloud.network.klalb.KLALBMain`: load config → build `KLALBProxySystem` → open Swing GUI (`KLALBStateGUI3`) unless `"nogui": true` → start `KLALBWebServer` (if `"webUI": true` or web server enabled, default port `4665`) → interactive console (`help`, `links-state`, `route`, `kperf`, ...).
- `org.kne.cloud.network.klalb.web.KLALBWebServer` — built-in HTTP/SSE server (JDK `HttpServer`):
  - API endpoints: `/api/status`, `/api/events` (SSE stream, 200ms intervals), `/api/links`, `/api/links/action`, `/api/links/reconnect`, `/api/routing-table`, `/api/nodes` (topology graph), `/api/node-info?address=<ipv6>` (on-demand full node info), `/api/config`.
  - Static file hosting / SPA fallback: serves `dashboard/dist/` assets directly.
- `org.kne.cloud.network` — generic socket framework: `VirtualSocket*` hierarchy, `SocketBridge` port-forwarding proxies, `ProtocolDetector` (multi-protocol mux on one port), `MultiProtocolSocketAddress` = URI-style addresses (`tcp://`, `udp://`, `kltp://`, `ntp://`) dispatched through the `SocketType` registry.
- `...network.klalb` — app core: `KLALBController` (the virtual SRv6 network), `KLALBRemoteLink` (WAN lines), `*Packet` wire-format classes, virtual socket implementations.
- `...network.congestion` — pluggable congestion control (BBR, Vegas2, DCTCP...), chosen via `"congestionAlgorithm"` in config.
- `...network.kltp` — custom reliable transport protocol (packets/streams).
- `...network.ipv6`, `...network.srv6` — packet codecs, route table, Dijkstra path computation.
- **Node-info query API** (`...network.srv6`, JSON datagrams on `KLALBRoutingProtocol.DEFAULT_PORT=1001`): `KLALBRoutingProtocolAPIServer/Client` speak two request types —
  - `nodeinfotinyreq/resp` → device name ONLY; never gated by any flag (name is public via broadcast anyway).
  - `nodeinfofullreq/resp` → externalEndpoints + deviceName + deviceDescription. `denyExternalEndpointQuery=true` hides ONLY the endpoint list (`data=null`); name/description still answer.
  - GUI rule: opening `NodeInformationPanel` = Full query; use `requestNodeInfoTiny` for lightweight/background lookups. Legacy `openlines*` message types were removed — mixed-version meshes get silence, so upgrade the whole network together.
  - `JsonDataPacket` stores its UTF-8 payload length in a 2-byte header field: keep every JSON message under 64 KiB.
- `...network.frpc` — frp client integration.
- `...klalb.ui` — all Swing UI code.

## Frontend (Dashboard)

Located in `dashboard/`:
- **Git layout**: `dashboard/` is a separate git repo wired in as a submodule (own origin on `git.code.cq.cn`). Commit frontend changes inside `dashboard/` first, then bump the submodule pointer in the parent repo — parent-repo commits alone do not capture them.
- **Stack**: Vite + React 19 + TypeScript + Tailwind CSS v4 + `@base-ui/react` (style: `base-nova`, icons: `lucide-react`, toasts: `@base-ui/react/toast`).
- **Routing**: Hash-based routing (`#/overview`, `#/connections`, `#/routing-table`, `#/topology`, `#/settings`) for seamless SPA hosting under Java `KLALBWebServer`.
- **Package Manager**: `pnpm` (run all commands from `dashboard/` directory).
- **Component installation**: **Must** use CLI via `pnpm dlx shadcn@latest add <component>` (e.g. `pnpm dlx shadcn@latest add alert card badge toast`). Never create or fake shadcn components manually. Non-shadcn libs (`@xyflow/react`, `d3-force`) are installed via plain `pnpm add`.
- **Commands**:
  - `pnpm dev` — Start Vite dev server (proxies `/api` to backend `http://127.0.0.1:4665`).
  - `pnpm build` — Typecheck and build SPA to `dashboard/dist` (which Java `KLALBWebServer` serves directly).
  - `pnpm lint` / `pnpm typecheck` — Verification.
- **Pages & data flow**:
  - Overview / Connections read the SSE stream (`use-klalb-sse.ts`, 200ms pushes of status + links).
  - Settings loads/saves `/api/config` (`use-klalb-config.ts`); save payload must keep legacy field aliases alongside new names for compatibility.
  - Routing table polls `/api/routing-table` every 1s (`use-routing-table.ts`); `cost` is delay-derived and displayed in milliseconds.
  - Topology polls `/api/nodes` every 1s (`use-topology.ts`) — SSE does NOT carry topology.
  - Selecting a topology node queries `/api/node-info`; remote node descriptions require a full SRv6 node-info request and can time out after 3s.
  - Topology layout: `d3-force` headless simulation (recomputed only when node/edge structure changes) rendered by `@xyflow/react` with custom `device-node` / `link-edge` components in `src/components/topology/`.
  - React hooks lint rule forbids `setState` synchronously inside effects — initialize form state via component `key` remount + lazy `useState(() => ...)` initializers (see `SettingsForm` pattern).

## Config

`klalb-config.json` is an array of items discriminated by their `"Type"` field. Adding a new item type requires a `KLALBConfigItem` subclass **plus** new cases in both `KLALBConfigItem.getDefaultJsonDeserializer()` and `getDefaultJsonSerializer()`; unknown types are preserved as `UnknownKLALBConfigItem`. Any Gson instance handling config must register these adapters via `registerToGsonBuilder` (see `KLALBProxySystem`).

Key controller config fields:
- `externalEndpoints` / `autoConnections`: published vs auto-connect endpoint lists (renamed from `openConnections`, which itself replaced legacy `LineTable`; the old name was a developer naming mistake — these addresses are this node's externally published endpoints, not "connections").
- `ntpServers`: time server list (replaces `ntpServerTable`).
- `denyExternalEndpointQuery` / `denyExternalEndpointBroadcast`: safety flags — the query flag hides ONLY the external-endpoint list in full node-info responses (device name/description still answer; Tiny queries are never gated), the broadcast flag disables LAN multicast discovery (renamed from `denyConnectionQuery` / `denyConnectionBroadcast`, which replaced `denyLineTableQuery` / `denyLineTableBroadcast`).
- `enableTUN`: boolean flag for TUN interface creation (`"TUNName"` configures device name).
- `webListen`: Web API listen address, normally `http://0.0.0.0:4665`; legacy `webPort` is accepted on load/API input.

Legacy JSON keys are still accepted on load: `KLALBConfigItem.getDefaultJsonDeserializer()` normalizes old key names (`openConnections`/`LineTable`, `denyConnectionQuery`, `denyLineTable*`, ...) before reflective deserialization (manual rewrite because gson-2.1 has no `@SerializedName(alternate=...)`), and `handleConfig` in the web server accepts them too. New saves always write canonical names.

Gson quirks:
- **gson-2.1 (vendored) is ancient**: its `JSON_ELEMENT` adapter factory only matches exact `JsonElement.class`, NOT subclasses. Calling `gson.toJson(Object)` with a runtime `JsonObject`/`JsonArray` reflectively serializes the internal field as `{"members": {...}}`. `KLALBWebServer.sendJsonResponse` guards against this by using `JsonElement.toString()` for JsonElement instances — keep that guard when adding new response paths. SSE avoids the issue entirely via `JsonObject.toString()`.
- `/api/config` GET/POST is parsed field-by-field in `KLALBWebServer.handleConfig` (NOT whole-object Gson reflection) because polymorphic fields (`List<InetAddress>`, `List<MultiProtocolSocketAddress>`) break reflective mapping. Keep new config fields in sync there, accepting both legacy and new JSON key names.
- `InetAddress`, `MultiProtocolSocketAddress`, and `KLALBConfigItem` custom adapters are registered on the shared Gson in `KLALBProxySystem`; the web server reuses that instance via `proxySystem.getGson()`.
- Saving via web API persists through `KLALBProxySystem.saveConfigToFile()` (GUI save consumer takes precedence when present).

## Conventions

- Sources are UTF-8; comments, log/UI strings, and commit messages are largely Chinese.
- UI strings go through `UIEnv.getRsb().getString(...)`; add keys to **both** `src/klalb_zh_CN.properties` and `src/klalb_en_US.properties`.
- `client.cfg`, `server.cfg`, `linetable.txt` at the root are example line-table/port-rule files loaded via the GUI file picker — not hardwired paths.
