Add fakeip support

docs/faq/fakeip.md

@@ -0,0 +1,20 @@
+# FakeIP
+
+FakeIP refers to a type of behavior in a program that simultaneously hijacks both DNS and connection requests. It
+responds to DNS requests with virtual results and restores mapping when accepting connections.
+
+#### Advantage
+
+* Retrieve the requested domain in places like IP routing (L3) where traffic detection is not possible to assist with routing.
+* Decrease an RTT on the first TCP request to a domain (the most common reason).
+
+#### Limitation
+
+* Its mechanism breaks applications that depend on returning correct remote addresses.
+* Only A and AAAA (IP) requests are supported, which may break applications that rely on other requests.
+
+#### Recommendation
+
+* Do not use if you do not need L3 routing.
+* If using tun, make sure FakeIP ranges is included in the tun's routes.
+* Enable `experimental.clash_api.store_fakeip` to persist FakeIP records, or use `dns.rules.rewrite_ttl` to avoid losing records after program restart in DNS cached environments.

docs/faq/fakeip.zh.md

@@ -0,0 +1,19 @@
+# FakeIP
+
+FakeIP 是指同时劫持 DNS 和连接请求的程序中的一种行为。它通过虚拟结果响应 DNS 请求，在接受连接时恢复映射。
+
+#### 优点
+
+* 在像 L3 路由这样无法进行流量探测的地方检索所请求的域名，以协助路由。
+* 减少对一个域的第一个 TCP 请求的 RTT（这是最常见的原因）。
+
+#### 限制
+
+* 它的机制会破坏依赖于返回正确远程地址的应用程序。
+* 仅支持 A 和 AAAA（IP）请求，这可能会破坏依赖于其他请求的应用程序。
+
+#### 建议
+
+* 如果不需要 L3 路由，请勿使用。
+* 如果使用 tun，请确保 tun 路由中包含 FakeIP 地址范围。
+* 启用 `experimental.clash_api.store_fakeip` 以持久化 FakeIP 记录，或者使用 `dns.rules.rewrite_ttl` 避免程序重启后在 DNS 被缓存的环境中丢失记录。

docs/faq/index.md

@@ -11,12 +11,6 @@ it doesn't fit, because it compromises performance or design clarity, or because
 If it bothers you that sing-box is missing feature X, please forgive us and investigate the features that sing-box does
 have. You might find that they compensate in interesting ways for the lack of X.
 
-#### Fake IP
-
-Fake IP (also called Fake DNS) is an invasive and imperfect DNS solution that breaks expected behavior, causes DNS leaks
-and makes many software unusable. It is recommended by some software that lacks DNS processing and caching, but sing-box
-does not need this.
-
 #### Naive outbound
 
 NaïveProxy's main function is chromium's network stack, and it makes no sense to implement only its transport protocol.

docs/faq/index.zh.md

@@ -9,11 +9,6 @@
 
 如果 sing-box 缺少功能 X 让您感到困扰，请原谅我们并调查 sing-box 确实有的功能。 您可能会发现它们以有趣的方式弥补了 X 的缺失。
 
-#### Fake IP
-
-Fake IP（也称 Fake DNS）是一种侵入性和不完善的 DNS 解决方案，它打破了预期的行为，导致 DNS 泄漏并使许多软件无法使用。
-一些缺乏 DNS 处理和缓存的软件推荐使用它，但 sing-box 不需要。
-
 #### Naive 出站
 
 NaïveProxy 的主要功能是 chromium 的网络栈，仅实现它的传输协议是舍本逐末的。