From e9aab3c2a5087c2165e5e5b9dd21a66b67b0183f Mon Sep 17 00:00:00 2001
From: Eugene Burkov <e.burkov@adguard.com>
Date: Wed, 19 Jan 2022 14:19:24 +0300
Subject: [PATCH] Pull request: 4133 empty rewrite

Merge in DNS/adguard-home-wiki from 4133-empty-rewrite to master

Squashed commit of the following:

commit 11deec72902b9231cde12bee4a7e5d6391a0cd3f
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Tue Jan 18 22:02:28 2022 +0300

    Hosts-Blocklists: imp rewrites description
---
 Hosts-Blocklists.md | 23 +++++++++++++++++++----
 1 file changed, 19 insertions(+), 4 deletions(-)

diff --git a/Hosts-Blocklists.md b/Hosts-Blocklists.md
index 0cf55e4..32c3886 100644
--- a/Hosts-Blocklists.md
+++ b/Hosts-Blocklists.md
@@ -345,7 +345,14 @@ $dnsrewrite=example.net
 $dnsrewrite=REFUSED
 ```
 
-The keywords, like `REFUSED`, MUST be in all caps.
+The keywords MUST be in all caps (e.g. `NOERROR`).  Keyword rewrites take
+precedence over the other and will result in an empty response with an
+appropriate response code.
+
+Before **v0.107.3** the only possible keyword is `REFUSED`.
+
+Since **v0.107.3** response codes `NOERROR`, `NXDOMAIN`, and `SERVFAIL` are also
+supported.
 
 The full syntax is of the form `RCODE;RRTYPE;VALUE`:
 
@@ -356,6 +363,9 @@ $dnsrewrite=NOERROR;CNAME;example.net
 $dnsrewrite=REFUSED;;
 ```
 
+Since **v0.107.3** a `$dnsrewrite` modifier with the `NOERROR` response code may
+also has empty `RRTYPE` and `VALUE` fields.
+
 The `CNAME` one is special because AdGuard Home will resolve the host and add
 its info to the response.  That is, if `example.net` has IP `1.2.3.4`, and the
 user has this in their filter rules:
@@ -382,9 +392,8 @@ Name:	example.net
 Address: 1.2.3.4
 ```
 
-Keyword rewrites (for example, `REFUSED`) take precedence over the other.  Next,
-the `CNAME` rewrite.  After that, all other records's values are summed as one
-response, so this:
+Next, the `CNAME` rewrite.  After that, all other records's values are summed as
+one response, so this:
 
 ```none
 ||example.com^$dnsrewrite=NOERROR;A;1.2.3.4
@@ -441,6 +450,12 @@ Currently supported RR types with examples:
 
  *  `||example.com^$dnsrewrite=NXDOMAIN;;` responds with an `NXDOMAIN` code.
 
+ *  `$dnstype=AAAA,denyallow=example.org,dnsrewrite=NOERROR;;` responds with an
+    empty `NOERROR` answers for all `AAAA` requests except the ones for
+    `example.org`.
+
+    **NOTE:** this is available since **v0.107.3**.
+
 Exception rules remove one or all rules:
 
  *  `@@||example.com^$dnsrewrite` removes all DNS rewrite rules.