LAN port scan forbidderとは何ですか？

LAN port scan forbidderはhttps://garywill.github.ioによって開発されたChromeの拡張機能で、その主な機能は「Forbid non-LAN web to access LAN」です。

拡張機能のスクリーンショット

LAN port scan forbidder拡張機能のCRXファイルをダウンロード

LAN port scan forbidder拡張子のファイルをcrx形式でダウンロードし、ブラウザにChrome拡張機能を手動でインストールするか、crxファイルを友達と共有して簡単にChrome拡張機能をインストールします。

拡張機能の使用方法

Forbid untrusted web to scan localhost or LAN.

## Source Code Repo
https://github.com/garywill/LAN-port-scan-forbidder

## What

Webs can try to fetch `127.0.0.1:xxxx` or `192.168.Y.Z:xxxx` to scan your open ports in LAN.

Although browsers have cross-domain protections, webs can't read response contents, **but** can still see the connection succeeds or fails.

There're already reports that some websites using that as tracking fingerprint.

> A web for testing: http://samy.pl/webscan/

## So

Forbid any website behaviors trying to connect to your LAN or localhost, if user is visiting the website via their domains or public IP addresses. (Read the source code `background.js` to see the logic)

> Using JS library [whitequark/ipaddr.js](https://github.com/whitequark/ipaddr.js) (MIT License) v2.0.0 to judge IP range.

### Notification

User can enable notification. When untrusted web tries to access private network and get blocked, will show up notification.

### Fallback operation

If user find a web broken, user can temporary set this addon disabled via toolbar button for:

- this one tab
- this one tab and new tabs opened by this tab
- this one window (Firefox only)
- globally

(above can be set as keyboard shortcuts)

there's showy toolbar button badge indicating disabling status.

## Cases when web LAN scan is properly used

Not all LAN-port-scan are evil.

- Some manufacturers provide web for user's browser to scan LAN for their product that need updating.

- Some softwares use `127.0.0.1` communication to interact between native program and web.

## Disclaimer

This open souce addon comes with no warranty. Use on you own risk!

拡張機能の基本情報

名前	LAN port scan forbidder
ID	lapppchpconamefemlnjdebbcpbncafl
公式URL	https://chromewebstore.google.com/detail/lan-port-scan-forbidder/lapppchpconamefemlnjdebbcpbncafl
説明	Forbid non-LAN web to access LAN
ファイルサイズ	35.41 KB
インストール数	310
現在のバージョン	0.6.1
最終更新日	2023-11-09
公開日	2021-12-25
開発者	https://garywill.github.io
Eメール	[email protected]
支払い方法	free
拡張機能のウェブサイト	https://github.com/garywill/LAN-port-scan-forbidder
ヘルプページのURL	https://github.com/garywill/LAN-port-scan-forbidder
プライバシーポリシーページのURL	https://github.com/garywill/garywill/blob/privacy_policy/README.md
対応言語	en
manifest.json
{ "update_url": "https:\/\/clients2.google.com\/service\/update2\/crx", "name": "LAN port scan forbidder", "description": "Forbid non-LAN web to access LAN", "manifest_version": 2, "version": "0.6.1", "homepage_url": "https:\/\/github.com\/garywill\/LAN-port-scan-forbidder\/", "author": { "name": "Garywill", "url": "https:\/\/garywill.github.io" }, "permissions": [ "webRequest", "webRequestBlocking", ":\/\/\/", "ws:\/\/\/", "wss:\/\/\/", "ftp:\/\/\/*", "contextMenus", "storage" ], "optional_permissions": [ "notifications" ], "icons": { "128": "icon.png" }, "background": { "page": "background.html" }, "browser_action": { "default_icon": "icon_gray.png", "default_title": "LAN port scan forbidder" }, "commands": { "_execute_browser_action": { "description": "Click toolbar button" }, "toggle_t": { "description": "Toggle for one tab" }, "toggle_h": { "description": "Toggle for one tab and new tabs opened by it" }, "toggle_global": { "description": "Toggle globally enable\/disable" } }, "options_ui": { "page": "options.html" } }