Pull request: 2704 local addresses vol.3

Merge in DNS/adguard-home from 2704-local-addresses-vol.3 to master

Updates #2704.
Updates #2829.
Updates #2928.

Squashed commit of the following:

commit 8c42355c0093a3ac6951f79a5211e7891800f93a
Author: Eugene Burkov <e.burkov@adguard.com>
Date:   Wed Apr 7 18:07:41 2021 +0300

    dnsforward: rm errors pkg

commit 7594a21a620239951039454dd5686a872e6f41a8
Merge: 830b0834 908452f8
Author: Eugene Burkov <e.burkov@adguard.com>
Date:   Wed Apr 7 18:00:03 2021 +0300

    Merge branch 'master' into 2704-local-addresses-vol.3

commit 830b0834090510096061fed20b600195ab3773b8
Author: Eugene Burkov <e.burkov@adguard.com>
Date:   Wed Apr 7 17:47:51 2021 +0300

    dnsforward: reduce local upstream timeout

commit 493e81d9e8bacdc690f88af29a38d211b9733c7e
Author: Ildar Kamalov <ik@adguard.com>
Date:   Tue Apr 6 19:11:00 2021 +0300

    client: private_upstream test

commit a0194ac28f15114578359b8c2460cd9af621e912
Author: Eugene Burkov <e.burkov@adguard.com>
Date:   Tue Apr 6 18:36:23 2021 +0300

    all: expand api, fix conflicts

commit 0f4e06836fed958391aa597c8b02453564980ca3
Merge: 89cf93ad 8746005d
Author: Eugene Burkov <e.burkov@adguard.com>
Date:   Tue Apr 6 18:35:04 2021 +0300

    Merge branch 'master' into 2704-local-addresses-vol.3

commit 89cf93ad4f26c2bf4f1b18ecaa4d3a1e169f9b06
Author: Ildar Kamalov <ik@adguard.com>
Date:   Tue Apr 6 18:02:40 2021 +0300

    client: add local ptr upstreams to upstream test

commit e6dd869dddd4888474d625cbb005bad6390e4760
Author: Ildar Kamalov <ik@adguard.com>
Date:   Tue Apr 6 15:24:22 2021 +0300

    client: add private DNS form

commit b858057b9a957a416117f22b8bd0025f90e8c758
Author: Eugene Burkov <e.burkov@adguard.com>
Date:   Tue Apr 6 13:05:28 2021 +0300

    aghstrings: mk cloning correct

commit 8009ba60a6a7d6ceb7b6483a29f4e68d533af243
Author: Eugene Burkov <e.burkov@adguard.com>
Date:   Tue Apr 6 12:37:46 2021 +0300

    aghstrings: fix lil bug

commit 0dd19f2e7cc7c0de21517c37abd8336a907e1c0d
Author: Eugene Burkov <e.burkov@adguard.com>
Date:   Mon Apr 5 20:45:01 2021 +0300

    all: log changes

commit eb5558d96fffa6e7bca7e14d3740d26e47382e23
Author: Eugene Burkov <e.burkov@adguard.com>
Date:   Mon Apr 5 20:18:53 2021 +0300

    dnsforward: keep the style

commit d6d5fcbde40a633129c0e04887b81cf0b1ce6875
Author: Eugene Burkov <e.burkov@adguard.com>
Date:   Mon Apr 5 20:02:52 2021 +0300

    dnsforward: disable redundant filtering for local ptr

commit 4f864c32027d10db9bcb4a264d2338df8c20afac
Author: Eugene Burkov <e.burkov@adguard.com>
Date:   Mon Apr 5 17:53:17 2021 +0300

    dnsforward: imp tests

commit 7848e6f2341868f8ba0bb839956a0b7444cf02ca
Author: Eugene Burkov <e.burkov@adguard.com>
Date:   Mon Apr 5 14:52:12 2021 +0300

    all: imp code

commit 19ac30653800eebf8aaee499f65560ae2d458a5a
Author: Eugene Burkov <e.burkov@adguard.com>
Date:   Sun Apr 4 16:28:05 2021 +0300

    all: mv more logic to aghstrings

commit fac892ec5f0d2e30d6d64def0609267bbae4a202
Author: Eugene Burkov <e.burkov@adguard.com>
Date:   Fri Apr 2 20:23:23 2021 +0300

    dnsforward: use filepath

commit 05a3aeef1181b914788d14c7519287d467ab301f
Author: Eugene Burkov <e.burkov@adguard.com>
Date:   Fri Apr 2 20:17:54 2021 +0300

    aghstrings: introduce the pkg

commit f24e1b63d6e1bf266a4ed063f46f86d7abf65663
Author: Eugene Burkov <e.burkov@adguard.com>
Date:   Fri Apr 2 20:01:23 2021 +0300

    all: imp code

commit 0217a0ebb341f99a90c9b68013bebf6ff73d08ae
Author: Eugene Burkov <e.burkov@adguard.com>
Date:   Fri Apr 2 18:04:13 2021 +0300

    openapi: log changes

... and 3 more commits

internal/home/config.go

@@ -98,6 +98,13 @@ type dnsConfig struct {
 	// For example, a machine called "myhost" can be addressed as
 	// "myhost.lan" when AutohostTLD is "lan".
 	AutohostTLD string `yaml:"autohost_tld"`
+
+	// ResolveClients enables and disables resolving clients with RDNS.
+	ResolveClients bool `yaml:"resolve_clients"`
+
+	// LocalPTRResolvers is the slice of addresses to be used as upstreams
+	// for PTR queries for locally-served networks.
+	LocalPTRResolvers []string `yaml:"local_ptr_upstreams"`
 }
 
 type tlsConfigSettings struct {
@@ -150,6 +157,7 @@ var config = configuration{
 		FilteringEnabled:           true, // whether or not use filter lists
 		FiltersUpdateIntervalHours: 24,
 		AutohostTLD:                "lan",
+		ResolveClients:             true,
 	},
 	TLS: tlsConfigSettings{
 		PortHTTPS:       443,
@@ -296,10 +304,12 @@ func (c *configuration) write() error {
 		config.DNS.DnsfilterConf = c
 	}
 
-	if Context.dnsServer != nil {
+	if s := Context.dnsServer; s != nil {
 		c := dnsforward.FilteringConfig{}
-		Context.dnsServer.WriteDiskConfig(&c)
+		s.WriteDiskConfig(&c)
 		config.DNS.FilteringConfig = c
+
+		config.DNS.LocalPTRResolvers, config.DNS.ResolveClients = s.RDNSSettings()
 	}
 
 	if Context.dhcpServer != nil {