# 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 (verified; `-encoding UTF-8` is mandatory — sources contain Chinese text):

```powershell
& javac -encoding UTF-8 -cp "lib/*" -d bin (Get-ChildItem -Recurse src -Filter *.java | ForEach-Object FullName)
```

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 `"TUNName": null` in `klalb-config.json` or leave the TUN Name empty in GUI settings. If omitted, it defaults to `"KLALB_SRv6"`.
- Routing broadcast (`RouterInfo`) transmits `deviceName` across the network, which topology and node overview panels display. `deviceDescription` and `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` → interactive console (`help`, `links-state`, `route`, `kperf`, ...).
- `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.
- `...network.frpc` — frp client integration.
- `...klalb.ui` — all Swing UI code.

## 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`).

## 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.