LAN port scan forbidder EN

Name: LAN port scan forbidder
Rating: 3.0 (2 reviews)
Author: GarryW

GarryW · Firefox

Forbid non-LAN webs to access LAN or localhost. An anti-scan protection

3.0/5 2 人评分 36用户 v0.6.2当前版本

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权限提示 该扩展申请访问所有网站（<all_urls>），意味着它可以读取你在任意站点的页面内容，包括已登录的页面。这是许多扩展正常工作的必要条件，但也值得你确认来源可信。

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简介

Forbid untrusted web to scan localhost or LAN. Browser addon.

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/

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 (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.

LAN port scan forbidder 是做什么的

LAN port scan forbidder 是一款面向 Firefox 的开发者工具类扩展，主要用来调试页面、查看样式与请求、测试接口、辅助前端开发。官方对它的介绍是：Forbid non-LAN webs to access LAN or localhost. An anti-scan protection在Firefox 附加组件商店（AMO）上，它当前版本 0.6.2，评分 3（2 人评价），约 36 名用户。

适合什么人用

从功能定位看，LAN port scan forbidder 更适合前端工程师、测试与需要经常查看页面结构的用户。如果你平时只是偶尔遇到相关需求，用浏览器自带功能也能凑合；但如果这件事每天都发生，装一个专门处理它的扩展通常比手动操作省事得多。需要注意的是它作用于所有网站，装上后建议先观察一两天，确认不影响常用站点的正常使用。