websvc: imp restart

Updates #4970.

Squashed commit of the following:

commit 10365d9c8474e9d9735f581fb32b2892b2153cc4
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Fri Sep 30 14:23:06 2022 +0300

    all: imp docs, names

commit cff1103a0618a6430dc91e7e018febbf313c12ba
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Fri Sep 30 14:02:38 2022 +0300

    home: imp content-type check

.github/stale.yml

@@ -4,15 +4,17 @@
 'daysUntilClose': 15
 # Issues with these labels will never be considered stale.
 'exemptLabels':
-- 'bug'
-- 'documentation'
-- 'enhancement'
-- 'feature request'
-- 'help wanted'
-- 'localization'
-- 'needs investigation'
-- 'recurrent'
-- 'research'
+  - 'bug'
+  - 'documentation'
+  - 'enhancement'
+  - 'feature request'
+  - 'help wanted'
+  - 'localization'
+  - 'needs investigation'
+  - 'recurrent'
+  - 'research'
+# Set to true to ignore issues in a milestone.
+'exemptMilestones': true
 # Label to use when marking an issue as stale.
 'staleLabel': 'wontfix'
 # Comment to post when marking an issue as stale. Set to `false` to disable.
@@ -22,3 +24,5 @@
   for your contributions.
 # Comment to post when closing a stale issue. Set to `false` to disable.
 'closeComment': false
+# Limit the number of actions per hour.
+'limitPerRun': 1

CHANGELOG.md

@@ -12,11 +12,75 @@ and this project adheres to
 ## [Unreleased]
 
 <!--
-## [v0.108.0] - 2022-12-01 (APPROX.)
+## [v0.108.0] - TBA (APPROX.)
 -->
 
 ### Security
 
+- As an additional CSRF protection measure, AdGuard Home now ensures that
+  requests that change its state but have no body (such as `POST
+  /control/stats_reset` requests) do not have a `Content-Type` header set on
+  them ([#4970]).
+
+### Fixed
+
+- `only application/json is allowed` errors in various APIs ([#4970]).
+
+[#4970]: https://github.com/AdguardTeam/AdGuardHome/issues/4970
+
+
+
+<!--
+## [v0.107.15] - 2022-10-26 (APPROX.)
+
+See also the [v0.107.15 GitHub milestone][ms-v0.107.15].
+
+[ms-v0.107.15]:   https://github.com/AdguardTeam/AdGuardHome/milestone/51?closed=1
+-->
+
+
+
+## [v0.107.14] - 2022-09-29
+
+See also the [v0.107.14 GitHub milestone][ms-v0.107.14].
+
+### Security
+
+A Cross-Site Request Forgery (CSRF) vulnerability has been discovered.  The CVE
+number is to be assigned.  We thank Daniel Elkabes from Mend.io for reporting
+this vulnerability to us.
+
+#### `SameSite` Policy
+
+The `SameSite` policy on the AdGuard Home session cookies is now set to `Lax`.
+Which means that the only cross-site HTTP request for which the browser is
+allowed to send the session cookie is navigating to the AdGuard Home domain.
+
+**Users are strongly advised to log out, clear browser cache, and log in again
+after updating.**
+
+#### Removal Of Plain-Text APIs (BREAKING API CHANGE)
+
+We have implemented several measures to prevent such vulnerabilities in the
+future, but some of these measures break backwards compatibility for the sake of
+better protection.
+
+The following APIs, which previously accepted or returned `text/plain` data,
+now accept or return data as JSON.  All new formats for the request and response
+bodies are documented in `openapi/openapi.yaml` and `openapi/CHANGELOG.md`.
+
+- `GET  /control/i18n/current_language`;
+- `POST /control/dhcp/find_active_dhcp`;
+- `POST /control/filtering/set_rules`;
+- `POST /control/i18n/change_language`.
+
+#### Stricter Content-Type Checks (BREAKING API CHANGE)
+
+All JSON APIs that expect a body now check if the request actually has
+`Content-Type` set to `application/json`.
+
+#### Other Security Changes
+
 - Weaker cipher suites that use the CBC (cipher block chaining) mode of
   operation have been disabled ([#2993]).
 
@@ -25,19 +89,15 @@ and this project adheres to
 - Support for plain (unencrypted) HTTP/2 ([#4930]).  This is useful for AdGuard
   Home installations behind a reverse proxy.
 
+### Fixed
+
+- Incorrect path template in DDR responses ([#4927]).
+
 [#2993]: https://github.com/AdguardTeam/AdGuardHome/issues/2993
+[#4927]: https://github.com/AdguardTeam/AdGuardHome/issues/4927
 [#4930]: https://github.com/AdguardTeam/AdGuardHome/issues/4930
 
-
-
-
-<!--
-## [v0.107.14] - 2022-10-05 (APPROX.)
-
-See also the [v0.107.14 GitHub milestone][ms-v0.107.14].
-
 [ms-v0.107.14]:   https://github.com/AdguardTeam/AdGuardHome/milestone/50?closed=1
--->
 
 
 
@@ -1236,11 +1296,12 @@ See also the [v0.104.2 GitHub milestone][ms-v0.104.2].
 
 
 <!--
-[Unreleased]: https://github.com/AdguardTeam/AdGuardHome/compare/v0.107.14...HEAD
-[v0.107.14]:  https://github.com/AdguardTeam/AdGuardHome/compare/v0.107.13...v0.107.14
+[Unreleased]: https://github.com/AdguardTeam/AdGuardHome/compare/v0.107.15...HEAD
+[v0.107.15]:  https://github.com/AdguardTeam/AdGuardHome/compare/v0.107.14...v0.107.15
 -->
 
-[Unreleased]: https://github.com/AdguardTeam/AdGuardHome/compare/v0.107.13...HEAD
+[Unreleased]: https://github.com/AdguardTeam/AdGuardHome/compare/v0.107.14...HEAD
+[v0.107.14]:  https://github.com/AdguardTeam/AdGuardHome/compare/v0.107.13...v0.107.14
 [v0.107.13]:  https://github.com/AdguardTeam/AdGuardHome/compare/v0.107.12...v0.107.13
 [v0.107.12]:  https://github.com/AdguardTeam/AdGuardHome/compare/v0.107.11...v0.107.12
 [v0.107.11]:  https://github.com/AdguardTeam/AdGuardHome/compare/v0.107.10...v0.107.11

Makefile

@@ -34,7 +34,7 @@ YARN_INSTALL_FLAGS = $(YARN_FLAGS) --network-timeout 120000 --silent\
 	--ignore-engines --ignore-optional --ignore-platform\
 	--ignore-scripts
 
-V1API = 0
+NEXTAPI = 0
 
 # Macros for the build-release target.  If FRONTEND_PREBUILT is 0, the
 # default, the macro $(BUILD_RELEASE_DEPS_$(FRONTEND_PREBUILT)) expands
@@ -63,7 +63,7 @@ ENV = env\
 	PATH="$${PWD}/bin:$$( "$(GO.MACRO)" env GOPATH )/bin:$${PATH}"\
 	RACE='$(RACE)'\
 	SIGN='$(SIGN)'\
-	V1API='$(V1API)'\
+	NEXTAPI='$(NEXTAPI)'\
 	VERBOSE='$(VERBOSE)'\
 	VERSION='$(VERSION)'\
 

SECURITY.md

@@ -0,0 +1,18 @@
+ #  Security Policy
+
+## Reporting a Vulnerability
+
+Please send your vulnerability reports to <security@adguard.com>.  To make sure
+that your report reaches us, please:
+
+1.  Include the words “AdGuard Home” and “vulnerability” to the subject line as
+    well as a short description of the vulnerability.  For example:
+
+     >  AdGuard Home API vulnerability: possible XSS attack
+
+2.  Make sure that the message body contains a clear description of the
+    vulnerability.
+
+If you have not received a reply to your email within 7 days, please make sure
+to follow up with us again at <security@adguard.com>.  Once again, make sure
+that the word “vulnerability” is in the subject line.

client/src/__locales/be.json

@@ -635,5 +635,6 @@
     "parental_control": "Бацькоўскі кантроль",
     "safe_browsing": "Бяспечны інтэрнэт",
     "served_from_cache": "{{value}} <i>(атрымана з кэша)</i>",
-    "form_error_password_length": "Пароль павінен быць не менш за {{value}} сімвалаў"
+    "form_error_password_length": "Пароль павінен быць не менш за {{value}} сімвалаў",
+    "anonymizer_notification": "<0>Заўвага:</0> Ананімізацыя IP уключана. Вы можаце адключыць яго ў <1>Агульных наладах</1> ."
 }

client/src/__locales/cs.json

@@ -635,5 +635,6 @@
     "parental_control": "Rodičovská ochrana",
     "safe_browsing": "Bezpečné prohlížení",
     "served_from_cache": "{{value}} <i>(převzato z mezipaměti)</i>",
-    "form_error_password_length": "Heslo musí být alespoň {{value}} znaků dlouhé"
+    "form_error_password_length": "Heslo musí být alespoň {{value}} znaků dlouhé",
+    "anonymizer_notification": "<0>Poznámka:</0> Anonymizace IP je zapnuta. Můžete ji vypnout v <1>Obecných nastaveních</1>."
 }

client/src/__locales/da.json

@@ -635,5 +635,6 @@
     "parental_control": "Forældrekontrol",
     "safe_browsing": "Sikker Browsing",
     "served_from_cache": "{{value}} <i>(leveret fra cache)</i>",
-    "form_error_password_length": "Adgangskoden skal udgøre mindst {{value}} tegn."
+    "form_error_password_length": "Adgangskoden skal udgøre mindst {{value}} tegn.",
+    "anonymizer_notification": "<0>Bemærk:</0> IP-anonymisering er aktiveret. Det kan deaktiveres via <1>Generelle indstillinger</1>."
 }

client/src/__locales/de.json

@@ -635,5 +635,6 @@
     "parental_control": "Kindersicherung",
     "safe_browsing": "Internetsicherheit",
     "served_from_cache": "{{value}} <i>(aus dem Cache abgerufen)</i>",
-    "form_error_password_length": "Das Passwort muss mindestens {{value}} Zeichen enthalten"
+    "form_error_password_length": "Das Passwort muss mindestens {{value}} Zeichen enthalten",
+    "anonymizer_notification": "<0>Hinweis:</0> Die IP-Anonymisierung ist aktiviert. Sie können sie in den <1>Allgemeinen Einstellungen</1> deaktivieren."
 }

client/src/__locales/es.json

@@ -635,5 +635,6 @@
     "parental_control": "Control parental",
     "safe_browsing": "Navegación segura",
     "served_from_cache": "{{value}} <i>(servido desde la caché)</i>",
-    "form_error_password_length": "La contraseña debe tener al menos {{value}} caracteres"
+    "form_error_password_length": "La contraseña debe tener al menos {{value}} caracteres",
+    "anonymizer_notification": "<0>Nota:</0> La anonimización de IP está habilitada. Puedes deshabilitarla en <1>Configuración general</1>."
 }

client/src/__locales/fi.json

@@ -635,5 +635,6 @@
     "parental_control": "Lapsilukko",
     "safe_browsing": "Turvallinen selaus",
     "served_from_cache": "{{value}} <i>(jaettu välimuistista)</i>",
-    "form_error_password_length": "Salasanan on oltava ainakin {{value}} merkkiä"
+    "form_error_password_length": "Salasanan on oltava ainakin {{value}} merkkiä",
+    "anonymizer_notification": "<0>Huomioi:</0> IP-osoitteen anonymisointi on käytössä. Voit poistaa sen käytöstä <1>Yleisistä asetuksista</1>."
 }

client/src/__locales/fr.json

@@ -635,5 +635,6 @@
     "parental_control": "Contrôle parental",
     "safe_browsing": "Navigation sécurisée",
     "served_from_cache": "{{value}} <i>(depuis le cache)</i>",
-    "form_error_password_length": "Le mot de passe doit comporter au moins {{value}} caractères"
+    "form_error_password_length": "Le mot de passe doit comporter au moins {{value}} caractères",
+    "anonymizer_notification": "<0>Note :</0> L'anonymisation IP est activée. Vous pouvez la désactiver dans les <1>paramètres généraux</1>."
 }

client/src/__locales/hr.json

@@ -635,5 +635,6 @@
     "parental_control": "Roditeljska zaštita",
     "safe_browsing": "Sigurno surfanje",
     "served_from_cache": "{{value}} <i>(dohvaćeno iz predmemorije)</i>",
-    "form_error_password_length": "Lozinka mora imati najmanje {{value}} znakova"
+    "form_error_password_length": "Lozinka mora imati najmanje {{value}} znakova",
+    "anonymizer_notification": "<0>Napomena:</0>IP anonimizacija je omogućena. Možete ju onemogućiti u <1>općim postavkama</1>."
 }

client/src/__locales/hu.json

@@ -635,5 +635,6 @@
     "parental_control": "Szülői felügyelet",
     "safe_browsing": "Biztonságos böngészés",
     "served_from_cache": "{{value}} <i>(gyorsítótárból kiszolgálva)</i>",
-    "form_error_password_length": "A jelszó legalább {{value}} karakter hosszú kell, hogy legyen"
+    "form_error_password_length": "A jelszó legalább {{value}} karakter hosszú kell, hogy legyen",
+    "anonymizer_notification": "<0>Megjegyzés:</0> Az IP anonimizálás engedélyezve van. Az <1>Általános beállításoknál letilthatja</1> ."
 }

client/src/__locales/id.json

@@ -635,5 +635,6 @@
     "parental_control": "Kontrol Orang Tua",
     "safe_browsing": "Penjelajahan Aman",
     "served_from_cache": "{{value}} <i>(disajikan dari cache)</i>",
-    "form_error_password_length": "Kata sandi harus minimal {{value}} karakter"
+    "form_error_password_length": "Kata sandi harus minimal {{value}} karakter",
+    "anonymizer_notification": "<0>Catatan:</0> Anonimisasi IP diaktifkan. Anda dapat menonaktifkannya di <1>Pengaturan umum</1> ."
 }

client/src/__locales/it.json

@@ -635,5 +635,6 @@
     "parental_control": "Controllo Parentale",
     "safe_browsing": "Navigazione Sicura",
     "served_from_cache": "{{value}} <i>(fornito dalla cache)</i>",
-    "form_error_password_length": "La password deve contenere almeno {{value}} caratteri"
+    "form_error_password_length": "La password deve contenere almeno {{value}} caratteri",
+    "anonymizer_notification": "<0>Attenzione:</0> L'anonimizzazione dell'IP è abilitata. Puoi disabilitarla in <1>Impostazioni generali</1>."
 }

client/src/__locales/ja.json

@@ -635,5 +635,6 @@
     "parental_control": "ペアレンタルコントロール",
     "safe_browsing": "セーフブラウジング",
     "served_from_cache": "{{value}} <i>(キャッシュから応答)</i>",
-    "form_error_password_length": "パスワードは{{value}}文字以上にしてください"
+    "form_error_password_length": "パスワードは{{value}}文字以上にしてください",
+    "anonymizer_notification": "【<0>注意</0>】IPの匿名化が有効になっています。 <1>一般設定</1>で無効にできます。"
 }

client/src/__locales/ko.json

@@ -635,5 +635,6 @@
     "parental_control": "자녀 보호",
     "safe_browsing": "세이프 브라우징",
     "served_from_cache": "{{value}} <i>(캐시에서 제공)</i>",
-    "form_error_password_length": "비밀번호는 {{value}}자 이상이어야 합니다"
+    "form_error_password_length": "비밀번호는 {{value}}자 이상이어야 합니다",
+    "anonymizer_notification": "<0>참고:</0> IP 익명화가 활성화되었습니다. <1>일반 설정</1>에서 비활성화할 수 있습니다."
 }

client/src/__locales/nl.json

@@ -557,7 +557,7 @@
     "fastest_addr_desc": "Alle DNS-servers bevragen en het snelste IP adres terugkoppelen. Dit zal de DNS verzoeken vertragen omdat AdGuard Home moet wachten op de antwoorden van alles DNS-servers, maar verbetert wel de connectiviteit.",
     "autofix_warning_text": "Als je op \"Repareren\" klikt, configureert AdGuard Home jouw systeem om de AdGuard Home DNS-server te gebruiken.",
     "autofix_warning_list": "De volgende taken worden uitgevoerd: <0> Deactiveren van Systeem DNSStubListener</0> <0> DNS-serveradres instellen op 127.0.0.1 </0> <0> Symbolisch koppelingsdoel van /etc/resolv.conf vervangen door /run/systemd/resolve/resolv.conf </0> <0> Stop DNSStubListener (herlaad systemd-resolved service) </0>",
-    "autofix_warning_result": "Als gevolg hiervan worden alle DNS-verzoeken van je systeem standaard door AdGuard Home verwerkt.",
+    "autofix_warning_result": "Als gevolg hiervan worden alle DNS-aanvragen van je systeem standaard door AdGuard Home verwerkt.",
     "tags_title": "Labels",
     "tags_desc": "Je kunt labels selecteren die overeenkomen met de client. Labels kunnen worden opgenomen in de filterregels om ze \n nauwkeuriger toe te passen. <0>Meer informatie</0>.",
     "form_select_tags": "Client tags selecteren",
@@ -628,12 +628,13 @@
     "original_response": "Oorspronkelijke reactie",
     "click_to_view_queries": "Klik om queries te bekijken",
     "port_53_faq_link": "Poort 53 wordt vaak gebruikt door services als DNSStubListener- of de systeem DNS-resolver. Lees a.u.b. <0>deze instructie</0> hoe dit is op te lossen.",
-    "adg_will_drop_dns_queries": "AdGuard Home zal alle DNS-verzoeken van deze cliënt laten vervallen.",
+    "adg_will_drop_dns_queries": "AdGuard Home zal alle DNS-aanvragen van deze cliënt laten vervallen.",
     "filter_allowlist": "WAARSCHUWING: Deze actie zal ook de regel \"{{disallowed_rule}}\" uitsluiten van de lijst met toegestane clients.",
     "last_rule_in_allowlist": "Kan deze client niet weigeren omdat het uitsluiten van de regel \"{{disallowed_rule}}\" de lijst \"Toegestane clients\" zal UITSCHAKELEN.",
     "use_saved_key": "De eerder opgeslagen sleutel gebruiken",
     "parental_control": "Ouderlijk toezicht",
     "safe_browsing": "Veilig browsen",
     "served_from_cache": "{{value}} <i>(geleverd vanuit cache)</i>",
-    "form_error_password_length": "Wachtwoord moet minimaal {{value}} tekens lang zijn"
+    "form_error_password_length": "Wachtwoord moet minimaal {{value}} tekens lang zijn",
+    "anonymizer_notification": "<0>Opmerking:</0> IP-anonimisering is ingeschakeld. Je kunt het uitschakelen in <1>Algemene instellingen</1>."
 }

client/src/__locales/pl.json

@@ -635,5 +635,6 @@
     "parental_control": "Kontrola rodzicielska",
     "safe_browsing": "Bezpieczne przeglądanie",
     "served_from_cache": "{{value}} <i>(podawane z pamięci podręcznej)</i>",
-    "form_error_password_length": "Hasło musi mieć co najmniej {{value}} znaków"
+    "form_error_password_length": "Hasło musi mieć co najmniej {{value}} znaków",
+    "anonymizer_notification": "<0>Uwaga:</0> Anonimizacja IP jest włączona. Możesz ją wyłączyć w <1>Ustawieniach ogólnych</1>."
 }

client/src/__locales/pt-br.json

@@ -635,5 +635,6 @@
     "parental_control": "Controle parental",
     "safe_browsing": "Navegação segura",
     "served_from_cache": "{{value}} <i>(servido do cache)</i>",
-    "form_error_password_length": "A senha deve ter pelo menos {{value}} caracteres"
+    "form_error_password_length": "A senha deve ter pelo menos {{value}} caracteres",
+    "anonymizer_notification": "<0>Observação:</0> A anonimização de IP está ativada. Você pode desativá-lo em <1>Configurações gerais</1>."
 }

client/src/__locales/pt-pt.json

@@ -635,5 +635,6 @@
     "parental_control": "Controlo parental",
     "safe_browsing": "Navegação segura",
     "served_from_cache": "{{value}} <i>(servido do cache)</i>",
-    "form_error_password_length": "A palavra-passe deve ter pelo menos {{value}} caracteres"
+    "form_error_password_length": "A palavra-passe deve ter pelo menos {{value}} caracteres",
+    "anonymizer_notification": "<0>Observação:</0> A anonimização de IP está ativada. Você pode desativá-la em <1>Definições gerais</1>."
 }

client/src/__locales/ro.json

@@ -635,5 +635,6 @@
     "parental_control": "Control Parental",
     "safe_browsing": "Navigare în siguranță",
     "served_from_cache": "{{value}} <i>(furnizat din cache)</i>",
-    "form_error_password_length": "Parola trebuie să aibă cel puțin {{value}} caractere"
+    "form_error_password_length": "Parola trebuie să aibă cel puțin {{value}} caractere",
+    "anonymizer_notification": "<0>Nota:</0> Anonimizarea IP este activată. Puteți să o dezactivați în <1>Setări generale</1>."
 }

client/src/__locales/ru.json

@@ -635,5 +635,6 @@
     "parental_control": "Родительский контроль",
     "safe_browsing": "Безопасный интернет",
     "served_from_cache": "{{value}} <i>(получено из кеша)</i>",
-    "form_error_password_length": "Пароль должен быть длиной не меньше {{value}} символов"
+    "form_error_password_length": "Пароль должен быть длиной не меньше {{value}} символов",
+    "anonymizer_notification": "<0>Внимание:</0> включена анонимизация IP-адресов. Вы можете отключить её в разделе <1>Основные настройки</1>."
 }

client/src/__locales/sk.json

@@ -635,5 +635,6 @@
     "parental_control": "Rodičovská kontrola",
     "safe_browsing": "Bezpečné prehliadanie",
     "served_from_cache": "{{value}} <i>(prevzatá z cache pamäte)</i>",
-    "form_error_password_length": "Heslo musí mať dĺžku aspoň {{value}} znakov"
+    "form_error_password_length": "Heslo musí mať dĺžku aspoň {{value}} znakov",
+    "anonymizer_notification": "<0>Poznámka:</0> Anonymizácia IP je zapnutá. Môžete ju vypnúť vo <1>Všeobecných nastaveniach</1>."
 }

client/src/__locales/sl.json

@@ -635,5 +635,6 @@
     "parental_control": "Starševski nadzor",
     "safe_browsing": "Varno brskanje",
     "served_from_cache": "{{value}} <i>(postreženo iz predpomnilnika)</i>",
-    "form_error_password_length": "Geslo mora vsebovati najmanj {{value}} znakov"
+    "form_error_password_length": "Geslo mora vsebovati najmanj {{value}} znakov",
+    "anonymizer_notification": "<0>Opomba:</0> Anonimizacija IP je omogočena. Onemogočite ga lahko v <1>Splošnih nastavitvah</1>."
 }

client/src/__locales/sr-cs.json

@@ -635,5 +635,6 @@
     "parental_control": "Roditeljska kontrola",
     "safe_browsing": "Sigurno pregledanje",
     "served_from_cache": "{{value}} <i>(posluženo iz predmemorije)</i>",
-    "form_error_password_length": "Lozinka mora imati najmanje {{value}} znakova"
+    "form_error_password_length": "Lozinka mora imati najmanje {{value}} znakova",
+    "anonymizer_notification": "<0>Nota:</0> IP prepoznavanje je omogućeno. Možete ga onemogućiti u opštim <1>postavkama</1>."
 }

client/src/__locales/sv.json

@@ -635,5 +635,6 @@
     "parental_control": "Föräldrakontroll",
     "safe_browsing": "Säker surfning",
     "served_from_cache": "{{value}} <i>(levereras från cache)</i>",
-    "form_error_password_length": "Lösenordet måste vara minst {{value}} tecken långt"
+    "form_error_password_length": "Lösenordet måste vara minst {{value}} tecken långt",
+    "anonymizer_notification": "<0>Observera:</0> IP-anonymisering är aktiverad. Du kan inaktivera den i <1>Allmänna inställningar</1>."
 }

client/src/__locales/tr.json

@@ -368,7 +368,7 @@
     "encryption_server_enter": "Alan adınızı girin",
     "encryption_server_desc": "Ayarlanırsa, AdGuard Home ClientID'leri algılar, DDR sorgularına yanıt verir ve ek bağlantı doğrulamaları gerçekleştirir. Ayarlanmazsa, bu özellikler devre dışı bırakılır. Sertifikadaki DNS Adlarından biriyle eşleşmelidir.",
     "encryption_redirect": "Otomatik olarak HTTPS'e yönlendir",
-    "encryption_redirect_desc": "Etkinleştirirseniz, AdGuard Home sizi HTTP adresi yerine HTTPS adresine yönlendirir.",
+    "encryption_redirect_desc": "İşaretlenirse, AdGuard Home sizi otomatik olarak HTTP adresinden HTTPS adreslerine yönlendirecektir.",
     "encryption_https": "HTTPS bağlantı noktası",
     "encryption_https_desc": "HTTPS bağlantı noktası yapılandırılırsa, AdGuard Home yönetici arayüzüne HTTPS aracılığıyla erişilebilir olacak ve ayrıca '/dns-query' üzerinden DNS-over-HTTPS bağlantısı sağlayacaktır.",
     "encryption_dot": "DNS-over-TLS bağlantı noktası",
@@ -408,7 +408,7 @@
     "fix": "Düzelt",
     "dns_providers": "Aralarından seçim yapabileceğiniz, bilinen <0>DNS sağlayıcıların listesi</0>.",
     "update_now": "Şimdi güncelle",
-    "update_failed": "Otomatik güncelleme başarısız oldu. Elle güncellemek için lütfen <a>bu adımları uygulayın</a>.",
+    "update_failed": "Otomatik güncelleme başarısız oldu. Elle güncellemek için lütfen <a>bu adımları izleyin</a>.",
     "manual_update": "Elle güncellemek için lütfen <a>bu adımları uygulayın</a>.",
     "processing_update": "Lütfen bekleyin, AdGuard Home güncelleniyor",
     "clients_title": "Kalıcı istemciler",
@@ -635,5 +635,6 @@
     "parental_control": "Ebeveyn Denetimi",
     "safe_browsing": "Güvenli Gezinti",
     "served_from_cache": "{{value}} <i>(önbellekten kullanıldı)</i>",
-    "form_error_password_length": "Parola en az {{value}} karakter uzunluğunda olmalıdır"
+    "form_error_password_length": "Parola en az {{value}} karakter uzunluğunda olmalıdır",
+    "anonymizer_notification": "<0>Not:</0> IP anonimleştirme etkinleştirildi. Bunu <1>Genel ayarlardan</1> devre dışı bırakabilirsiniz."
 }

client/src/__locales/uk.json

@@ -635,5 +635,6 @@
     "parental_control": "Батьківський контроль",
     "safe_browsing": "Безпечний перегляд",
     "served_from_cache": "{{value}} <i>(отримано з кешу)</i>",
-    "form_error_password_length": "Пароль мусить мати принаймні {{value}} символів"
+    "form_error_password_length": "Пароль мусить мати принаймні {{value}} символів",
+    "anonymizer_notification": "<0>Примітка:</0> IP-анонімізацію ввімкнено. Ви можете вимкнути його в <1>Загальні налаштування</1> ."
 }

client/src/__locales/vi.json

@@ -635,5 +635,6 @@
     "parental_control": "Quản lý của phụ huynh",
     "safe_browsing": "Duyệt web an toàn",
     "served_from_cache": "{{value}} <i>(được phục vụ từ bộ nhớ cache)</i>",
-    "form_error_password_length": "Mật khẩu phải có ít nhất {{value}} ký tự"
+    "form_error_password_length": "Mật khẩu phải có ít nhất {{value}} ký tự",
+    "anonymizer_notification": "<0> Lưu ý:</0> Tính năng ẩn danh IP được bật. Bạn có thể tắt nó trong <1> Cài đặt chung</1>."
 }

client/src/__locales/zh-cn.json

@@ -635,5 +635,6 @@
     "parental_control": "家长控制",
     "safe_browsing": "安全浏览",
     "served_from_cache": "{{value}}<i>(由缓存提供)</i>",
-    "form_error_password_length": "密码必须至少有 {{value}} 个字符"
+    "form_error_password_length": "密码必须至少有 {{value}} 个字符",
+    "anonymizer_notification": "<0>注意：</0> IP 匿名化已启用。您可以在<1>常规设置</1>中禁用它。"
 }

client/src/__locales/zh-tw.json

@@ -635,5 +635,6 @@
     "parental_control": "家長控制",
     "safe_browsing": "安全瀏覽",
     "served_from_cache": "{{value}} <i>(由快取提供)</i>",
-    "form_error_password_length": "密碼必須為至少長 {{value}} 個字元"
+    "form_error_password_length": "密碼必須為至少長 {{value}} 個字元",
+    "anonymizer_notification": "<0>注意：</0>IP 匿名化被啟用。您可在<1>一般設定</1>中禁用它。"
 }

client/src/actions/filtering.js

@@ -31,7 +31,9 @@ export const setRulesSuccess = createAction('SET_RULES_SUCCESS');
 export const setRules = (rules) => async (dispatch) => {
     dispatch(setRulesRequest());
     try {
-        const normalizedRules = normalizeRulesTextarea(rules);
+        const normalizedRules = {
+            rules: normalizeRulesTextarea(rules)?.split('\n'),
+        };
         await apiClient.setRules(normalizedRules);
         dispatch(addSuccessToast('updated_custom_filtering_toast'));
         dispatch(setRulesSuccess());

client/src/actions/index.js

@@ -355,7 +355,7 @@ export const changeLanguageSuccess = createAction('CHANGE_LANGUAGE_SUCCESS');
 export const changeLanguage = (lang) => async (dispatch) => {
     dispatch(changeLanguageRequest());
     try {
-        await apiClient.changeLanguage(lang);
+        await apiClient.changeLanguage({ language: lang });
         dispatch(changeLanguageSuccess());
     } catch (error) {
         dispatch(addErrorToast({ error }));
@@ -370,8 +370,8 @@ export const getLanguageSuccess = createAction('GET_LANGUAGE_SUCCESS');
 export const getLanguage = () => async (dispatch) => {
     dispatch(getLanguageRequest());
     try {
-        const language = await apiClient.getCurrentLanguage();
-        dispatch(getLanguageSuccess(language));
+        const langSettings = await apiClient.getCurrentLanguage();
+        dispatch(getLanguageSuccess(langSettings.language));
     } catch (error) {
         dispatch(addErrorToast({ error }));
         dispatch(getLanguageFailure());
@@ -421,7 +421,10 @@ export const findActiveDhcpFailure = createAction('FIND_ACTIVE_DHCP_FAILURE');
 export const findActiveDhcp = (name) => async (dispatch, getState) => {
     dispatch(findActiveDhcpRequest());
     try {
-        const activeDhcp = await apiClient.findActiveDhcp(name);
+        const req = {
+            interface: name,
+        };
+        const activeDhcp = await apiClient.findActiveDhcp(req);
         dispatch(findActiveDhcpSuccess(activeDhcp));
         const { check, interface_name, interfaces } = getState().dhcp;
         const selectedInterface = getState().form[FORM_NAME.DHCP_INTERFACES].values.interface_name;

client/src/api/Api.js

@@ -10,11 +10,17 @@ class Api {
     async makeRequest(path, method = 'POST', config) {
         const url = `${this.baseUrl}/${path}`;
 
+        const axiosConfig = config || {};
+        if (method !== 'GET' && axiosConfig.data) {
+            axiosConfig.headers = axiosConfig.headers || {};
+            axiosConfig.headers['Content-Type'] = axiosConfig.headers['Content-Type'] || 'application/json';
+        }
+
         try {
             const response = await axios({
                 url,
                 method,
-                ...config,
+                ...axiosConfig,
             });
             return response.data;
         } catch (error) {
@@ -55,7 +61,6 @@ class Api {
         const { path, method } = this.GLOBAL_TEST_UPSTREAM_DNS;
         const config = {
             data: servers,
-            headers: { 'Content-Type': 'application/json' },
         };
         return this.makeRequest(path, method, config);
     }
@@ -64,7 +69,6 @@ class Api {
         const { path, method } = this.GLOBAL_VERSION;
         const config = {
             data,
-            headers: { 'Content-Type': 'application/json' },
         };
         return this.makeRequest(path, method, config);
     }
@@ -100,7 +104,6 @@ class Api {
         const { path, method } = this.FILTERING_REFRESH;
         const parameters = {
             data: config,
-            headers: { 'Content-Type': 'application/json' },
         };
 
         return this.makeRequest(path, method, parameters);
@@ -110,7 +113,6 @@ class Api {
         const { path, method } = this.FILTERING_ADD_FILTER;
         const parameters = {
             data: config,
-            headers: { 'Content-Type': 'application/json' },
         };
 
         return this.makeRequest(path, method, parameters);
@@ -120,7 +122,6 @@ class Api {
         const { path, method } = this.FILTERING_REMOVE_FILTER;
         const parameters = {
             data: config,
-            headers: { 'Content-Type': 'application/json' },
         };
 
         return this.makeRequest(path, method, parameters);
@@ -130,7 +131,6 @@ class Api {
         const { path, method } = this.FILTERING_SET_RULES;
         const parameters = {
             data: rules,
-            headers: { 'Content-Type': 'text/plain' },
         };
         return this.makeRequest(path, method, parameters);
     }
@@ -139,7 +139,6 @@ class Api {
         const { path, method } = this.FILTERING_CONFIG;
         const parameters = {
             data: config,
-            headers: { 'Content-Type': 'application/json' },
         };
         return this.makeRequest(path, method, parameters);
     }
@@ -148,7 +147,6 @@ class Api {
         const { path, method } = this.FILTERING_SET_URL;
         const parameters = {
             data: config,
-            headers: { 'Content-Type': 'application/json' },
         };
         return this.makeRequest(path, method, parameters);
     }
@@ -173,12 +171,7 @@ class Api {
 
     enableParentalControl() {
         const { path, method } = this.PARENTAL_ENABLE;
-        const parameter = 'sensitivity=TEEN'; // this parameter TEEN is hardcoded
-        const config = {
-            data: parameter,
-            headers: { 'Content-Type': 'text/plain' },
-        };
-        return this.makeRequest(path, method, config);
+        return this.makeRequest(path, method);
     }
 
     disableParentalControl() {
@@ -240,11 +233,10 @@ class Api {
         return this.makeRequest(path, method);
     }
 
-    changeLanguage(lang) {
+    changeLanguage(config) {
         const { path, method } = this.CHANGE_LANGUAGE;
         const parameters = {
-            data: lang,
-            headers: { 'Content-Type': 'text/plain' },
+            data: config,
         };
         return this.makeRequest(path, method, parameters);
     }
@@ -280,16 +272,14 @@ class Api {
         const { path, method } = this.DHCP_SET_CONFIG;
         const parameters = {
             data: config,
-            headers: { 'Content-Type': 'application/json' },
         };
         return this.makeRequest(path, method, parameters);
     }
 
-    findActiveDhcp(name) {
+    findActiveDhcp(req) {
         const { path, method } = this.DHCP_FIND_ACTIVE;
         const parameters = {
-            data: name,
-            headers: { 'Content-Type': 'text/plain' },
+            data: req,
         };
         return this.makeRequest(path, method, parameters);
     }
@@ -298,7 +288,6 @@ class Api {
         const { path, method } = this.DHCP_ADD_STATIC_LEASE;
         const parameters = {
             data: config,
-            headers: { 'Content-Type': 'application/json' },
         };
         return this.makeRequest(path, method, parameters);
     }
@@ -307,7 +296,6 @@ class Api {
         const { path, method } = this.DHCP_REMOVE_STATIC_LEASE;
         const parameters = {
             data: config,
-            headers: { 'Content-Type': 'application/json' },
         };
         return this.makeRequest(path, method, parameters);
     }
@@ -338,7 +326,6 @@ class Api {
         const { path, method } = this.INSTALL_CONFIGURE;
         const parameters = {
             data: config,
-            headers: { 'Content-Type': 'application/json' },
         };
         return this.makeRequest(path, method, parameters);
     }
@@ -347,7 +334,6 @@ class Api {
         const { path, method } = this.INSTALL_CHECK_CONFIG;
         const parameters = {
             data: config,
-            headers: { 'Content-Type': 'application/json' },
         };
         return this.makeRequest(path, method, parameters);
     }
@@ -368,7 +354,6 @@ class Api {
         const { path, method } = this.TLS_CONFIG;
         const parameters = {
             data: config,
-            headers: { 'Content-Type': 'application/json' },
         };
         return this.makeRequest(path, method, parameters);
     }
@@ -377,7 +362,6 @@ class Api {
         const { path, method } = this.TLS_VALIDATE;
         const parameters = {
             data: config,
-            headers: { 'Content-Type': 'application/json' },
         };
         return this.makeRequest(path, method, parameters);
     }
@@ -402,7 +386,6 @@ class Api {
         const { path, method } = this.ADD_CLIENT;
         const parameters = {
             data: config,
-            headers: { 'Content-Type': 'application/json' },
         };
         return this.makeRequest(path, method, parameters);
     }
@@ -411,7 +394,6 @@ class Api {
         const { path, method } = this.DELETE_CLIENT;
         const parameters = {
             data: config,
-            headers: { 'Content-Type': 'application/json' },
         };
         return this.makeRequest(path, method, parameters);
     }
@@ -420,7 +402,6 @@ class Api {
         const { path, method } = this.UPDATE_CLIENT;
         const parameters = {
             data: config,
-            headers: { 'Content-Type': 'application/json' },
         };
         return this.makeRequest(path, method, parameters);
     }
@@ -445,7 +426,6 @@ class Api {
         const { path, method } = this.ACCESS_SET;
         const parameters = {
             data: config,
-            headers: { 'Content-Type': 'application/json' },
         };
         return this.makeRequest(path, method, parameters);
     }
@@ -466,7 +446,6 @@ class Api {
         const { path, method } = this.REWRITE_ADD;
         const parameters = {
             data: config,
-            headers: { 'Content-Type': 'application/json' },
         };
         return this.makeRequest(path, method, parameters);
     }
@@ -475,7 +454,6 @@ class Api {
         const { path, method } = this.REWRITE_DELETE;
         const parameters = {
             data: config,
-            headers: { 'Content-Type': 'application/json' },
         };
         return this.makeRequest(path, method, parameters);
     }
@@ -501,7 +479,6 @@ class Api {
         const { path, method } = this.BLOCKED_SERVICES_SET;
         const parameters = {
             data: config,
-            headers: { 'Content-Type': 'application/json' },
         };
         return this.makeRequest(path, method, parameters);
     }
@@ -529,7 +506,6 @@ class Api {
         const { path, method } = this.STATS_CONFIG;
         const config = {
             data,
-            headers: { 'Content-Type': 'application/json' },
         };
         return this.makeRequest(path, method, config);
     }
@@ -565,7 +541,6 @@ class Api {
         const { path, method } = this.QUERY_LOG_CONFIG;
         const config = {
             data,
-            headers: { 'Content-Type': 'application/json' },
         };
         return this.makeRequest(path, method, config);
     }
@@ -582,7 +557,6 @@ class Api {
         const { path, method } = this.LOGIN;
         const config = {
             data,
-            headers: { 'Content-Type': 'application/json' },
         };
         return this.makeRequest(path, method, config);
     }
@@ -609,7 +583,6 @@ class Api {
         const { path, method } = this.SET_DNS_CONFIG;
         const config = {
             data,
-            headers: { 'Content-Type': 'application/json' },
         };
         return this.makeRequest(path, method, config);
     }

client/src/components/Logs/Cells/ClientCell.js

@@ -62,7 +62,7 @@ const ClientCell = ({
         'white-space--nowrap': isDetailed,
     });
 
-    const hintClass = classNames('icons mr-4 icon--24 icon--lightgray', {
+    const hintClass = classNames('icons mr-4 icon--24 logs__question icon--lightgray', {
         'my-3': isDetailed,
     });
 

client/src/components/Logs/Cells/DomainCell.js

@@ -34,7 +34,7 @@ const DomainCell = ({
         'my-3': isDetailed,
     });
 
-    const privacyIconClass = classNames('icons mx-2 icon--24 d-none d-sm-block', {
+    const privacyIconClass = classNames('icons mx-2 icon--24 d-none d-sm-block logs__question', {
         'icon--green': hasTracker,
         'icon--disabled': !hasTracker,
         'my-3': isDetailed,

client/src/components/Logs/Cells/IconTooltip.css

@@ -49,6 +49,12 @@
     padding-top: 1rem;
 }
 
+@media (max-width: 1024px) {
+    .grid .key-colon, .grid .title--border {
+        font-weight: 600;
+    }
+}
+
 @media (max-width: 767.98px) {
     .grid {
         grid-template-columns: 35% 55%;
@@ -70,10 +76,6 @@
         grid-column: 2 / span 1;
         margin: 0 !important;
     }
-
-    .grid .key-colon, .grid .title--border {
-        font-weight: 600;
-    }
 }
 
 .grid .key-colon:nth-child(odd)::after {

client/src/components/Logs/Cells/ResponseCell.js

@@ -97,7 +97,7 @@ const ResponseCell = ({
     return (
         <div className="logs__cell logs__cell--response" role="gridcell">
             <IconTooltip
-                className={classNames('icons mr-4 icon--24 icon--lightgray', { 'my-3': isDetailed })}
+                className={classNames('icons mr-4 icon--24 icon--lightgray logs__question', { 'my-3': isDetailed })}
                 columnClass='grid grid--limited'
                 tooltipClass='px-5 pb-5 pt-4 mw-75 custom-tooltip__response-details'
                 contentItemClass='text-truncate key-colon o-hidden'

client/src/components/Logs/Logs.css

@@ -485,3 +485,13 @@
 .bg--green {
     color: var(--green79);
 }
+
+@media (max-width: 1024px) {
+    .logs__question {
+        display: none;
+    }
+}
+
+.logs__modal {
+    max-width: 720px;
+}

client/src/components/Logs/index.js

@@ -184,27 +184,34 @@ const Logs = () => {
                 setButtonType={setButtonType}
                 setModalOpened={setModalOpened}
         />
-        <Modal portalClassName='grid' isOpen={isSmallScreen && isModalOpened}
-               onRequestClose={closeModal}
-               style={{
-                   content: {
-                       width: '100%',
-                       height: 'fit-content',
-                       left: 0,
-                       top: 47,
-                       padding: '1rem 1.5rem 1rem',
-                   },
-                   overlay: {
-                       backgroundColor: 'rgba(0,0,0,0.5)',
-                   },
-               }}
+        <Modal
+            portalClassName='grid'
+            isOpen={isSmallScreen && isModalOpened}
+            onRequestClose={closeModal}
+            style={{
+                content: {
+                    width: '100%',
+                    height: 'fit-content',
+                    left: '50%',
+                    top: 47,
+                    padding: '1rem 1.5rem 1rem',
+                    maxWidth: '720px',
+                    transform: 'translateX(-50%)',
+                },
+                overlay: {
+                    backgroundColor: 'rgba(0,0,0,0.5)',
+                },
+            }}
         >
-            <svg
-                    className="icon icon--24 icon-cross d-block d-md-none cursor--pointer"
-                    onClick={closeModal}>
-                <use xlinkHref="#cross" />
-            </svg>
-            {processContent(detailedDataCurrent, buttonType)}
+            <div className="logs__modal-wrap">
+                <svg
+                    className="icon icon--24 icon-cross d-block cursor--pointer"
+                    onClick={closeModal}
+                >
+                    <use xlinkHref="#cross" />
+                </svg>
+                {processContent(detailedDataCurrent, buttonType)}
+            </div>
         </Modal>
     </>;
 

internal/aghchan/aghchan.go

@@ -0,0 +1,33 @@
+// Package aghchan contains channel utilities.
+package aghchan
+
+import (
+	"fmt"
+	"time"
+)
+
+// Receive returns an error if it cannot receive a value form c before timeout
+// runs out.
+func Receive[T any](c <-chan T, timeout time.Duration) (v T, ok bool, err error) {
+	var zero T
+	timeoutCh := time.After(timeout)
+	select {
+	case <-timeoutCh:
+		// TODO(a.garipov): Consider implementing [errors.Aser] for
+		// os.ErrTimeout.
+		return zero, false, fmt.Errorf("did not receive after %s", timeout)
+	case v, ok = <-c:
+		return v, ok, nil
+	}
+}
+
+// MustReceive panics if it cannot receive a value form c before timeout runs
+// out.
+func MustReceive[T any](c <-chan T, timeout time.Duration) (v T, ok bool) {
+	v, ok, err := Receive(c, timeout)
+	if err != nil {
+		panic(err)
+	}
+
+	return v, ok
+}

internal/aghhttp/aghhttp.go

@@ -2,13 +2,21 @@
 package aghhttp
 
 import (
+	"encoding/json"
 	"fmt"
 	"io"
 	"net/http"
 
+	"github.com/AdguardTeam/AdGuardHome/internal/version"
 	"github.com/AdguardTeam/golibs/log"
 )
 
+// HTTP scheme constants.
+const (
+	SchemeHTTP  = "http"
+	SchemeHTTPS = "https"
+)
+
 // RegisterFunc is the function that sets the handler to handle the URL for the
 // method.
 //
@@ -25,6 +33,43 @@ func OK(w http.ResponseWriter) {
 // Error writes formatted message to w and also logs it.
 func Error(r *http.Request, w http.ResponseWriter, code int, format string, args ...any) {
 	text := fmt.Sprintf(format, args...)
-	log.Error("%s %s: %s", r.Method, r.URL, text)
+	log.Error("%s %s %s: %s", r.Method, r.Host, r.URL, text)
 	http.Error(w, text, code)
 }
+
+// UserAgent returns the ID of the service as a User-Agent string.  It can also
+// be used as the value of the Server HTTP header.
+func UserAgent() (ua string) {
+	return fmt.Sprintf("AdGuardHome/%s", version.Version())
+}
+
+// textPlainDeprMsg is the message returned to API users when they try to use
+// an API that used to accept "text/plain" but doesn't anymore.
+const textPlainDeprMsg = `using this api with the text/plain content-type is deprecated; ` +
+	`use application/json`
+
+// WriteTextPlainDeprecated responds to the request with a message about
+// deprecation and removal of a plain-text API if the request is made with the
+// "text/plain" content-type.
+func WriteTextPlainDeprecated(w http.ResponseWriter, r *http.Request) (isPlainText bool) {
+	if r.Header.Get(HdrNameContentType) != HdrValTextPlain {
+		return false
+	}
+
+	Error(r, w, http.StatusUnsupportedMediaType, textPlainDeprMsg)
+
+	return true
+}
+
+// WriteJSONResponse sets the content-type header in w.Header() to
+// "application/json", encodes resp to w, calls Error on any returned error, and
+// returns it as well.
+func WriteJSONResponse(w http.ResponseWriter, r *http.Request, resp any) (err error) {
+	w.Header().Set(HdrNameContentType, HdrValApplicationJSON)
+	err = json.NewEncoder(w).Encode(resp)
+	if err != nil {
+		Error(r, w, http.StatusInternalServerError, "encoding resp: %s", err)
+	}
+
+	return err
+}

internal/aghhttp/header.go

@@ -0,0 +1,22 @@
+package aghhttp
+
+// HTTP Headers
+
+// HTTP header name constants.
+//
+// TODO(a.garipov): Remove unused.
+const (
+	HdrNameAcceptEncoding           = "Accept-Encoding"
+	HdrNameAccessControlAllowOrigin = "Access-Control-Allow-Origin"
+	HdrNameContentEncoding          = "Content-Encoding"
+	HdrNameContentType              = "Content-Type"
+	HdrNameServer                   = "Server"
+	HdrNameTrailer                  = "Trailer"
+	HdrNameUserAgent                = "User-Agent"
+)
+
+// HTTP header value constants.
+const (
+	HdrValApplicationJSON = "application/json"
+	HdrValTextPlain       = "text/plain"
+)

internal/aghnet/hostscontainer_test.go

@@ -10,9 +10,9 @@ import (
 	"testing/fstest"
 	"time"
 
+	"github.com/AdguardTeam/AdGuardHome/internal/aghchan"
 	"github.com/AdguardTeam/AdGuardHome/internal/aghtest"
 	"github.com/AdguardTeam/golibs/errors"
-	"github.com/AdguardTeam/golibs/netutil"
 	"github.com/AdguardTeam/golibs/stringutil"
 	"github.com/AdguardTeam/golibs/testutil"
 	"github.com/AdguardTeam/urlfilter"
@@ -163,15 +163,9 @@ func TestHostsContainer_refresh(t *testing.T) {
 	checkRefresh := func(t *testing.T, want *HostsRecord) {
 		t.Helper()
 
-		var ok bool
-		var upd *netutil.IPMap
-		select {
-		case upd, ok = <-hc.Upd():
-			require.True(t, ok)
-			require.NotNil(t, upd)
-		case <-time.After(1 * time.Second):
-			t.Fatal("did not receive after 1s")
-		}
+		upd, ok := aghchan.MustReceive(hc.Upd(), 1*time.Second)
+		require.True(t, ok)
+		require.NotNil(t, upd)
 
 		assert.Equal(t, 1, upd.Len())
 

internal/aghnet/ipset_linux.go

@@ -18,27 +18,18 @@ import (
 
 // How to test on a real Linux machine:
 //
-// 1.  Run:
+//  1. Run "sudo ipset create example_set hash:ip family ipv4".
 //
-//   sudo ipset create example_set hash:ip family ipv4
+//  2. Run "sudo ipset list example_set".  The Members field should be empty.
 //
-// 2.  Run:
+//  3. Add the line "example.com/example_set" to your AdGuardHome.yaml.
 //
-//   sudo ipset list example_set
+//  4. Start AdGuardHome.
 //
-// The Members field should be empty.
+//  5. Make requests to example.com and its subdomains.
 //
-// 3.  Add the line "example.com/example_set" to your AdGuardHome.yaml.
-//
-// 4.  Start AdGuardHome.
-//
-// 5.  Make requests to example.com and its subdomains.
-//
-// 6.  Run:
-//
-//   sudo ipset list example_set
-//
-// The Members field should contain the resolved IP addresses.
+//  6. Run "sudo ipset list example_set".  The Members field should contain the
+//     resolved IP addresses.
 
 // newIpsetMgr returns a new Linux ipset manager.
 func newIpsetMgr(ipsetConf []string) (set IpsetManager, err error) {

internal/aghtest/interface.go

@@ -1,6 +1,7 @@
 package aghtest
 
 import (
+	"context"
 	"io/fs"
 	"net"
 
@@ -15,6 +16,8 @@ import (
 
 // Standard Library
 
+// Package fs
+
 // type check
 var _ fs.FS = &FS{}
 
@@ -58,6 +61,8 @@ func (fsys *StatFS) Stat(name string) (fs.FileInfo, error) {
 	return fsys.OnStat(name)
 }
 
+// Package net
+
 // type check
 var _ net.Listener = (*Listener)(nil)
 
@@ -83,32 +88,10 @@ func (l *Listener) Close() (err error) {
 	return l.OnClose()
 }
 
-// Module dnsproxy
-
-// type check
-var _ upstream.Upstream = (*UpstreamMock)(nil)
-
-// UpstreamMock is a mock [upstream.Upstream] implementation for tests.
-//
-// TODO(a.garipov): Replace with all uses of Upstream with UpstreamMock and
-// rename it to just Upstream.
-type UpstreamMock struct {
-	OnAddress  func() (addr string)
-	OnExchange func(req *dns.Msg) (resp *dns.Msg, err error)
-}
-
-// Address implements the [upstream.Upstream] interface for *UpstreamMock.
-func (u *UpstreamMock) Address() (addr string) {
-	return u.OnAddress()
-}
-
-// Exchange implements the [upstream.Upstream] interface for *UpstreamMock.
-func (u *UpstreamMock) Exchange(req *dns.Msg) (resp *dns.Msg, err error) {
-	return u.OnExchange(req)
-}
-
 // Module AdGuardHome
 
+// Package aghos
+
 // type check
 var _ aghos.FSWatcher = (*FSWatcher)(nil)
 
@@ -133,3 +116,57 @@ func (w *FSWatcher) Add(name string) (err error) {
 func (w *FSWatcher) Close() (err error) {
 	return w.OnClose()
 }
+
+// Package websvc
+
+// ServiceWithConfig is a mock [websvc.ServiceWithConfig] implementation for
+// tests.
+type ServiceWithConfig[ConfigType any] struct {
+	OnStart    func() (err error)
+	OnShutdown func(ctx context.Context) (err error)
+	OnConfig   func() (c ConfigType)
+}
+
+// Start implements the [websvc.ServiceWithConfig] interface for
+// *ServiceWithConfig.
+func (s *ServiceWithConfig[_]) Start() (err error) {
+	return s.OnStart()
+}
+
+// Shutdown implements the [websvc.ServiceWithConfig] interface for
+// *ServiceWithConfig.
+func (s *ServiceWithConfig[_]) Shutdown(ctx context.Context) (err error) {
+	return s.OnShutdown(ctx)
+}
+
+// Config implements the [websvc.ServiceWithConfig] interface for
+// *ServiceWithConfig.
+func (s *ServiceWithConfig[ConfigType]) Config() (c ConfigType) {
+	return s.OnConfig()
+}
+
+// Module dnsproxy
+
+// Package upstream
+
+// type check
+var _ upstream.Upstream = (*UpstreamMock)(nil)
+
+// UpstreamMock is a mock [upstream.Upstream] implementation for tests.
+//
+// TODO(a.garipov): Replace with all uses of Upstream with UpstreamMock and
+// rename it to just Upstream.
+type UpstreamMock struct {
+	OnAddress  func() (addr string)
+	OnExchange func(req *dns.Msg) (resp *dns.Msg, err error)
+}
+
+// Address implements the [upstream.Upstream] interface for *UpstreamMock.
+func (u *UpstreamMock) Address() (addr string) {
+	return u.OnAddress()
+}
+
+// Exchange implements the [upstream.Upstream] interface for *UpstreamMock.
+func (u *UpstreamMock) Exchange(req *dns.Msg) (resp *dns.Msg, err error) {
+	return u.OnExchange(req)
+}

internal/aghtest/interface_test.go

@@ -1,9 +1,9 @@
 package aghtest_test
 
 import (
-	"github.com/AdguardTeam/AdGuardHome/internal/aghos"
 	"github.com/AdguardTeam/AdGuardHome/internal/aghtest"
+	"github.com/AdguardTeam/AdGuardHome/internal/next/websvc"
 )
 
 // type check
-var _ aghos.FSWatcher = (*aghtest.FSWatcher)(nil)
+var _ websvc.ServiceWithConfig[struct{}] = (*aghtest.ServiceWithConfig[struct{}])(nil)

internal/dhcpd/http_unix.go

@@ -5,11 +5,9 @@ package dhcpd
 import (
 	"encoding/json"
 	"fmt"
-	"io"
 	"net"
 	"net/http"
 	"os"
-	"strings"
 
 	"github.com/AdguardTeam/AdGuardHome/internal/aghalg"
 	"github.com/AdguardTeam/AdGuardHome/internal/aghhttp"
@@ -410,31 +408,37 @@ type dhcpSearchResult struct {
 	V6 dhcpSearchV6Result `json:"v6"`
 }
 
-// Perform the following tasks:
-// . Search for another DHCP server running
-// . Check if a static IP is configured for the network interface
-// Respond with results
+// findActiveServerReq is the JSON structure for the request to find active DHCP
+// servers.
+type findActiveServerReq struct {
+	Interface string `json:"interface"`
+}
+
+// handleDHCPFindActiveServer performs the following tasks:
+//  1. searches for another DHCP server in the network;
+//  2. check if a static IP is configured for the network interface;
+//  3. responds with the results.
 func (s *server) handleDHCPFindActiveServer(w http.ResponseWriter, r *http.Request) {
-	// This use of ReadAll is safe, because request's body is now limited.
-	body, err := io.ReadAll(r.Body)
+	if aghhttp.WriteTextPlainDeprecated(w, r) {
+		return
+	}
+
+	req := &findActiveServerReq{}
+	err := json.NewDecoder(r.Body).Decode(req)
 	if err != nil {
-		msg := fmt.Sprintf("failed to read request body: %s", err)
-		log.Error(msg)
-		http.Error(w, msg, http.StatusBadRequest)
+		aghhttp.Error(r, w, http.StatusBadRequest, "reading req: %s", err)
 
 		return
 	}
 
-	ifaceName := strings.TrimSpace(string(body))
+	ifaceName := req.Interface
 	if ifaceName == "" {
-		msg := "empty interface name specified"
-		log.Error(msg)
-		http.Error(w, msg, http.StatusBadRequest)
+		aghhttp.Error(r, w, http.StatusBadRequest, "empty interface name")
 
 		return
 	}
 
-	result := dhcpSearchResult{
+	result := &dhcpSearchResult{
 		V4: dhcpSearchV4Result{
 			OtherServer: dhcpSearchOtherResult{
 				Found: "no",
@@ -459,6 +463,14 @@ func (s *server) handleDHCPFindActiveServer(w http.ResponseWriter, r *http.Reque
 		result.V4.StaticIP.IP = aghnet.GetSubnet(ifaceName).String()
 	}
 
+	setOtherDHCPResult(ifaceName, result)
+
+	_ = aghhttp.WriteJSONResponse(w, r, result)
+}
+
+// setOtherDHCPResult sets the results of the check for another DHCP server in
+// result.
+func setOtherDHCPResult(ifaceName string, result *dhcpSearchResult) {
 	found4, found6, err4, err6 := aghnet.CheckOtherDHCP(ifaceName)
 	if err4 != nil {
 		result.V4.OtherServer.Found = "error"
@@ -466,24 +478,13 @@ func (s *server) handleDHCPFindActiveServer(w http.ResponseWriter, r *http.Reque
 	} else if found4 {
 		result.V4.OtherServer.Found = "yes"
 	}
+
 	if err6 != nil {
 		result.V6.OtherServer.Found = "error"
 		result.V6.OtherServer.Error = err6.Error()
 	} else if found6 {
 		result.V6.OtherServer.Found = "yes"
 	}
-
-	w.Header().Set("Content-Type", "application/json")
-	err = json.NewEncoder(w).Encode(result)
-	if err != nil {
-		aghhttp.Error(
-			r,
-			w,
-			http.StatusInternalServerError,
-			"Failed to marshal DHCP found json: %s",
-			err,
-		)
-	}
 }
 
 func (s *server) handleDHCPAddStaticLease(w http.ResponseWriter, r *http.Request) {

internal/dnsforward/dns.go

@@ -296,7 +296,7 @@ func (s *Server) makeDDRResponse(req *dns.Msg) (resp *dns.Msg) {
 		values := []dns.SVCBKeyValue{
 			&dns.SVCBAlpn{Alpn: []string{"h2"}},
 			&dns.SVCBPort{Port: uint16(addr.Port)},
-			&dns.SVCBDoHPath{Template: "/dns-query?dns"},
+			&dns.SVCBDoHPath{Template: "/dns-query{?dns}"},
 		}
 
 		ans := &dns.SVCB{

internal/dnsforward/dns_test.go

@@ -26,7 +26,7 @@ func TestServer_ProcessDDRQuery(t *testing.T) {
 		Value: []dns.SVCBKeyValue{
 			&dns.SVCBAlpn{Alpn: []string{"h2"}},
 			&dns.SVCBPort{Port: 8044},
-			&dns.SVCBDoHPath{Template: "/dns-query?dns"},
+			&dns.SVCBDoHPath{Template: "/dns-query{?dns}"},
 		},
 	}
 

internal/dnsforward/dnsforward_test.go

@@ -67,10 +67,11 @@ func createTestServer(
 		ID: 0, Data: []byte(rules),
 	}}
 
-	f := filtering.New(filterConf, filters)
+	f, err := filtering.New(filterConf, filters)
+	require.NoError(t, err)
+
 	f.SetEnabled(true)
 
-	var err error
 	s, err = NewServer(DNSCreateParams{
 		DHCPServer:  testDHCP,
 		DNSFilter:   f,
@@ -774,7 +775,9 @@ func TestBlockedCustomIP(t *testing.T) {
 		Data: []byte(rules),
 	}}
 
-	f := filtering.New(&filtering.Config{}, filters)
+	f, err := filtering.New(&filtering.Config{}, filters)
+	require.NoError(t, err)
+
 	s, err := NewServer(DNSCreateParams{
 		DHCPServer:  testDHCP,
 		DNSFilter:   f,
@@ -906,7 +909,9 @@ func TestRewrite(t *testing.T) {
 			Type:   dns.TypeCNAME,
 		}},
 	}
-	f := filtering.New(c, nil)
+	f, err := filtering.New(c, nil)
+	require.NoError(t, err)
+
 	f.SetEnabled(true)
 
 	s, err := NewServer(DNSCreateParams{
@@ -1021,19 +1026,14 @@ var testDHCP = &dhcpd.MockInterface{
 	OnWriteDiskConfig:   func(c *dhcpd.ServerConfig) { panic("not implemented") },
 }
 
-// func (*testDHCP) Leases(flags dhcpd.GetLeasesFlags) (leases []*dhcpd.Lease) {
-// 	return []*dhcpd.Lease{{
-// 		IP:       net.IP{192, 168, 12, 34},
-// 		HWAddr:   net.HardwareAddr{0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA},
-// 		Hostname: "myhost",
-// 	}}
-// }
-
 func TestPTRResponseFromDHCPLeases(t *testing.T) {
 	const localDomain = "lan"
 
+	flt, err := filtering.New(&filtering.Config{}, nil)
+	require.NoError(t, err)
+
 	s, err := NewServer(DNSCreateParams{
-		DNSFilter:   filtering.New(&filtering.Config{}, nil),
+		DNSFilter:   flt,
 		DHCPServer:  testDHCP,
 		PrivateNets: netutil.SubnetSetFunc(netutil.IsLocallyServed),
 		LocalDomain: localDomain,
@@ -1100,9 +1100,11 @@ func TestPTRResponseFromHosts(t *testing.T) {
 		assert.Equal(t, uint32(1), atomic.LoadUint32(&eventsCalledCounter))
 	})
 
-	flt := filtering.New(&filtering.Config{
+	flt, err := filtering.New(&filtering.Config{
 		EtcHosts: hc,
 	}, nil)
+	require.NoError(t, err)
+
 	flt.SetEnabled(true)
 
 	var s *Server

internal/dnsforward/filter_test.go

@@ -35,7 +35,8 @@ func TestHandleDNSRequest_filterDNSResponse(t *testing.T) {
 		ID: 0, Data: []byte(rules),
 	}}
 
-	f := filtering.New(&filtering.Config{}, filters)
+	f, err := filtering.New(&filtering.Config{}, filters)
+	require.NoError(t, err)
 	f.SetEnabled(true)
 
 	s, err := NewServer(DNSCreateParams{

internal/filtering/blocked.go

@@ -421,31 +421,34 @@ func initBlockedServices() {
 }
 
 // BlockedSvcKnown - return TRUE if a blocked service name is known
-func BlockedSvcKnown(s string) bool {
-	_, ok := serviceRules[s]
+func BlockedSvcKnown(s string) (ok bool) {
+	_, ok = serviceRules[s]
+
 	return ok
 }
 
 // ApplyBlockedServices - set blocked services settings for this DNS request
-func (d *DNSFilter) ApplyBlockedServices(setts *Settings, list []string, global bool) {
+func (d *DNSFilter) ApplyBlockedServices(setts *Settings, list []string) {
 	setts.ServicesRules = []ServiceEntry{}
-	if global {
+	if list == nil {
 		d.confLock.RLock()
 		defer d.confLock.RUnlock()
+
 		list = d.Config.BlockedServices
 	}
+
 	for _, name := range list {
 		rules, ok := serviceRules[name]
-
 		if !ok {
 			log.Error("unknown service name: %s", name)
+
 			continue
 		}
 
-		s := ServiceEntry{}
-		s.Name = name
-		s.Rules = rules
-		setts.ServicesRules = append(setts.ServicesRules, s)
+		setts.ServicesRules = append(setts.ServicesRules, ServiceEntry{
+			Name:  name,
+			Rules: rules,
+		})
 	}
 }
 
@@ -490,10 +493,3 @@ func (d *DNSFilter) handleBlockedServicesSet(w http.ResponseWriter, r *http.Requ
 
 	d.ConfigModified()
 }
-
-// registerBlockedServicesHandlers - register HTTP handlers
-func (d *DNSFilter) registerBlockedServicesHandlers() {
-	d.Config.HTTPRegister(http.MethodGet, "/control/blocked_services/services", d.handleBlockedServicesAvailableServices)
-	d.Config.HTTPRegister(http.MethodGet, "/control/blocked_services/list", d.handleBlockedServicesList)
-	d.Config.HTTPRegister(http.MethodPost, "/control/blocked_services/set", d.handleBlockedServicesSet)
-}

internal/filtering/dnsrewrite_test.go

@@ -49,7 +49,7 @@ func TestDNSFilter_CheckHostRules_dnsrewrite(t *testing.T) {
 |1.2.3.5.in-addr.arpa^$dnsrewrite=NOERROR;PTR;new-ptr-with-dot.
 `
 
-	f := newForTest(t, nil, []Filter{{ID: 0, Data: []byte(text)}})
+	f, _ := newForTest(t, nil, []Filter{{ID: 0, Data: []byte(text)}})
 	setts := &Settings{
 		FilteringEnabled: true,
 	}

internal/filtering/filter.go

@@ -1,4 +1,4 @@
-package home
+package filtering
 
 import (
 	"bufio"
@@ -8,63 +8,29 @@ import (
 	"net/http"
 	"os"
 	"path/filepath"
-	"regexp"
 	"strconv"
 	"strings"
-	"sync"
-	"sync/atomic"
 	"time"
 
-	"github.com/AdguardTeam/AdGuardHome/internal/filtering"
 	"github.com/AdguardTeam/golibs/errors"
 	"github.com/AdguardTeam/golibs/log"
 	"github.com/AdguardTeam/golibs/stringutil"
+	"golang.org/x/exp/slices"
 )
 
-var nextFilterID = time.Now().Unix() // semi-stable way to generate an unique ID
+// filterDir is the subdirectory of a data directory to store downloaded
+// filters.
+const filterDir = "filters"
 
-// Filtering - module object
-type Filtering struct {
-	// conf FilteringConf
-	refreshStatus     uint32 // 0:none; 1:in progress
-	refreshLock       sync.Mutex
-	filterTitleRegexp *regexp.Regexp
-}
+// nextFilterID is a way to seed a unique ID generation.
+//
+// TODO(e.burkov):  Use more deterministic approach.
+var nextFilterID = time.Now().Unix()
 
-// Init - initialize the module
-func (f *Filtering) Init() {
-	f.filterTitleRegexp = regexp.MustCompile(`^! Title: +(.*)$`)
-	_ = os.MkdirAll(filepath.Join(Context.getDataDir(), filterDir), 0o755)
-	f.loadFilters(config.Filters)
-	f.loadFilters(config.WhitelistFilters)
-	deduplicateFilters()
-	updateUniqueFilterID(config.Filters)
-	updateUniqueFilterID(config.WhitelistFilters)
-}
-
-// Start - start the module
-func (f *Filtering) Start() {
-	f.RegisterFilteringHandlers()
-
-	// Here we should start updating filters,
-	//  but currently we can't wake up the periodic task to do so.
-	// So for now we just start this periodic task from here.
-	go f.periodicallyRefreshFilters()
-}
-
-// Close - close the module
-func (f *Filtering) Close() {
-}
-
-func defaultFilters() []filter {
-	return []filter{
-		{Filter: filtering.Filter{ID: 1}, Enabled: true, URL: "https://adguardteam.github.io/AdGuardSDNSFilter/Filters/filter.txt", Name: "AdGuard DNS filter"},
-		{Filter: filtering.Filter{ID: 2}, Enabled: false, URL: "https://adaway.org/hosts.txt", Name: "AdAway Default Blocklist"},
-	}
-}
-
-// field ordering is important -- yaml fields will mirror ordering from here
-type filter struct {
+// FilterYAML respresents a filter list in the configuration file.
+//
+// TODO(e.burkov):  Investigate if the field oredering is important.
+type FilterYAML struct {
 	Enabled     bool
 	URL         string    // URL or a file path
 	Name        string    `yaml:"name"`
@@ -73,91 +39,108 @@ type filter struct {
 	checksum    uint32    // checksum of the file data
 	white       bool
 
-	filtering.Filter `yaml:",inline"`
+	Filter `yaml:",inline"`
+}
+
+// Clear filter rules
+func (filter *FilterYAML) unload() {
+	filter.RulesCount = 0
+	filter.checksum = 0
+}
+
+// Path to the filter contents
+func (filter *FilterYAML) Path(dataDir string) string {
+	return filepath.Join(dataDir, filterDir, strconv.FormatInt(filter.ID, 10)+".txt")
 }
 
 const (
-	statusFound          = 1
-	statusEnabledChanged = 2
-	statusURLChanged     = 4
-	statusURLExists      = 8
-	statusUpdateRequired = 0x10
+	statusFound = 1 << iota
+	statusEnabledChanged
+	statusURLChanged
+	statusURLExists
+	statusUpdateRequired
 )
 
 // Update properties for a filter specified by its URL
 // Return status* flags.
-func (f *Filtering) filterSetProperties(url string, newf filter, whitelist bool) int {
+func (d *DNSFilter) filterSetProperties(url string, newf FilterYAML, whitelist bool) int {
 	r := 0
-	config.Lock()
-	defer config.Unlock()
+	d.filtersMu.Lock()
+	defer d.filtersMu.Unlock()
 
-	filters := &config.Filters
+	filters := d.Filters
 	if whitelist {
-		filters = &config.WhitelistFilters
+		filters = d.WhitelistFilters
 	}
 
-	for i := range *filters {
-		filt := &(*filters)[i]
-		if filt.URL != url {
-			continue
+	i := slices.IndexFunc(filters, func(filt FilterYAML) bool {
+		return filt.URL == url
+	})
+	if i == -1 {
+		return 0
+	}
+
+	filt := &filters[i]
+
+	log.Debug("filter: set properties: %s: {%s %s %v}", filt.URL, newf.Name, newf.URL, newf.Enabled)
+	filt.Name = newf.Name
+
+	if filt.URL != newf.URL {
+		r |= statusURLChanged | statusUpdateRequired
+		if d.filterExistsNoLock(newf.URL) {
+			return statusURLExists
 		}
 
-		log.Debug("filter: set properties: %s: {%s %s %v}",
-			filt.URL, newf.Name, newf.URL, newf.Enabled)
-		filt.Name = newf.Name
+		filt.URL = newf.URL
+		filt.unload()
+		filt.LastUpdated = time.Time{}
+		filt.checksum = 0
+		filt.RulesCount = 0
+	}
 
-		if filt.URL != newf.URL {
-			r |= statusURLChanged | statusUpdateRequired
-			if filterExistsNoLock(newf.URL) {
-				return statusURLExists
-			}
-			filt.URL = newf.URL
-			filt.unload()
-			filt.LastUpdated = time.Time{}
-			filt.checksum = 0
-			filt.RulesCount = 0
-		}
+	if filt.Enabled != newf.Enabled {
+		r |= statusEnabledChanged
+		filt.Enabled = newf.Enabled
+		if filt.Enabled {
+			if (r & statusURLChanged) == 0 {
+				err := d.load(filt)
+				if err != nil {
+					// TODO(e.burkov):  It seems the error is only returned when
+					// the file exists and couldn't be open.  Investigate and
+					// improve.
+					log.Error("loading filter %d: %s", filt.ID, err)
 
-		if filt.Enabled != newf.Enabled {
-			r |= statusEnabledChanged
-			filt.Enabled = newf.Enabled
-			if filt.Enabled {
-				if (r & statusURLChanged) == 0 {
-					e := f.load(filt)
-					if e != nil {
-						// This isn't a fatal error,
-						//  because it may occur when someone removes the file from disk.
-						filt.LastUpdated = time.Time{}
-						filt.checksum = 0
-						filt.RulesCount = 0
-						r |= statusUpdateRequired
-					}
+					filt.LastUpdated = time.Time{}
+					filt.checksum = 0
+					filt.RulesCount = 0
+					r |= statusUpdateRequired
 				}
-			} else {
-				filt.unload()
 			}
+		} else {
+			filt.unload()
 		}
-
-		return r | statusFound
 	}
-	return 0
+
+	return r | statusFound
 }
 
 // Return TRUE if a filter with this URL exists
-func filterExists(url string) bool {
-	config.RLock()
-	r := filterExistsNoLock(url)
-	config.RUnlock()
+func (d *DNSFilter) filterExists(url string) bool {
+	d.filtersMu.RLock()
+	defer d.filtersMu.RUnlock()
+
+	r := d.filterExistsNoLock(url)
+
 	return r
 }
 
-func filterExistsNoLock(url string) bool {
-	for _, f := range config.Filters {
+func (d *DNSFilter) filterExistsNoLock(url string) bool {
+	for _, f := range d.Filters {
 		if f.URL == url {
 			return true
 		}
 	}
-	for _, f := range config.WhitelistFilters {
+	for _, f := range d.WhitelistFilters {
 		if f.URL == url {
 			return true
 		}
@@ -167,26 +150,26 @@ func filterExistsNoLock(url string) bool {
 
 // Add a filter
 // Return FALSE if a filter with this URL exists
-func filterAdd(f filter) bool {
-	config.Lock()
-	defer config.Unlock()
+func (d *DNSFilter) filterAdd(flt FilterYAML) bool {
+	d.filtersMu.Lock()
+	defer d.filtersMu.Unlock()
 
 	// Check for duplicates
-	if filterExistsNoLock(f.URL) {
+	if d.filterExistsNoLock(flt.URL) {
 		return false
 	}
 
-	if f.white {
-		config.WhitelistFilters = append(config.WhitelistFilters, f)
+	if flt.white {
+		d.WhitelistFilters = append(d.WhitelistFilters, flt)
 	} else {
-		config.Filters = append(config.Filters, f)
+		d.Filters = append(d.Filters, flt)
 	}
 	return true
 }
 
 // Load filters from the disk
 // And if any filter has zero ID, assign a new one
-func (f *Filtering) loadFilters(array []filter) {
+func (d *DNSFilter) loadFilters(array []FilterYAML) {
 	for i := range array {
 		filter := &array[i] // otherwise we're operating on a copy
 		if filter.ID == 0 {
@@ -198,32 +181,30 @@ func (f *Filtering) loadFilters(array []filter) {
 			continue
 		}
 
-		err := f.load(filter)
+		err := d.load(filter)
 		if err != nil {
 			log.Error("Couldn't load filter %d contents due to %s", filter.ID, err)
 		}
 	}
 }
 
-func deduplicateFilters() {
-	// Deduplicate filters
-	i := 0 // output index, used for deletion later
-	urls := map[string]bool{}
-	for _, filter := range config.Filters {
-		if _, ok := urls[filter.URL]; !ok {
-			// we didn't see it before, keep it
-			urls[filter.URL] = true // remember the URL
-			config.Filters[i] = filter
-			i++
+func deduplicateFilters(filters []FilterYAML) (deduplicated []FilterYAML) {
+	urls := stringutil.NewSet()
+	lastIdx := 0
+
+	for _, filter := range filters {
+		if !urls.Has(filter.URL) {
+			urls.Add(filter.URL)
+			filters[lastIdx] = filter
+			lastIdx++
 		}
 	}
 
-	// all entries we want to keep are at front, delete the rest
-	config.Filters = config.Filters[:i]
+	return filters[:lastIdx]
 }
 
 // Set the next filter ID to max(filter.ID) + 1
-func updateUniqueFilterID(filters []filter) {
+func updateUniqueFilterID(filters []FilterYAML) {
 	for _, filter := range filters {
 		if nextFilterID < filter.ID {
 			nextFilterID = filter.ID + 1
@@ -238,22 +219,19 @@ func assignUniqueFilterID() int64 {
 }
 
 // Sets up a timer that will be checking for filters updates periodically
-func (f *Filtering) periodicallyRefreshFilters() {
+func (d *DNSFilter) periodicallyRefreshFilters() {
 	const maxInterval = 1 * 60 * 60
 	intval := 5 // use a dynamically increasing time interval
 	for {
-		isNetworkErr := false
-		if config.DNS.FiltersUpdateIntervalHours != 0 && atomic.CompareAndSwapUint32(&f.refreshStatus, 0, 1) {
-			f.refreshLock.Lock()
-			_, isNetworkErr = f.refreshFiltersIfNecessary(filterRefreshBlocklists | filterRefreshAllowlists)
-			f.refreshLock.Unlock()
-			f.refreshStatus = 0
-			if !isNetworkErr {
+		isNetErr, ok := false, false
+		if d.FiltersUpdateIntervalHours != 0 {
+			_, isNetErr, ok = d.tryRefreshFilters(true, true, false)
+			if ok && !isNetErr {
 				intval = maxInterval
 			}
 		}
 
-		if isNetworkErr {
+		if isNetErr {
 			intval *= 2
 			if intval > maxInterval {
 				intval = maxInterval
@@ -264,51 +242,73 @@ func (f *Filtering) periodicallyRefreshFilters() {
 	}
 }
 
-// Refresh filters
-// flags: filterRefresh*
-// important:
+// tryRefreshFilters is like [refreshFilters], but backs down if the update is
+// already going on.
 //
-// TRUE: ignore the fact that we're currently updating the filters
-func (f *Filtering) refreshFilters(flags int, important bool) (int, error) {
-	set := atomic.CompareAndSwapUint32(&f.refreshStatus, 0, 1)
-	if !important && !set {
-		return 0, fmt.Errorf("filters update procedure is already running")
+// TODO(e.burkov):  Get rid of the concurrency pattern which requires the
+// sync.Mutex.TryLock.
+func (d *DNSFilter) tryRefreshFilters(block, allow, force bool) (updated int, isNetworkErr, ok bool) {
+	if ok = d.refreshLock.TryLock(); !ok {
+		return 0, false, ok
 	}
+	defer d.refreshLock.Unlock()
 
-	f.refreshLock.Lock()
-	nUpdated, _ := f.refreshFiltersIfNecessary(flags)
-	f.refreshLock.Unlock()
-	f.refreshStatus = 0
-	return nUpdated, nil
+	updated, isNetworkErr = d.refreshFiltersIntl(block, allow, force)
+
+	return updated, isNetworkErr, ok
 }
 
-func (f *Filtering) refreshFiltersArray(filters *[]filter, force bool) (int, []filter, []bool, bool) {
-	var updateFilters []filter
+// refreshFilters updates the lists and returns the number of updated ones.
+// It's safe for concurrent use, but blocks at least until the previous
+// refreshing is finished.
+func (d *DNSFilter) refreshFilters(block, allow, force bool) (updated int) {
+	d.refreshLock.Lock()
+	defer d.refreshLock.Unlock()
+
+	updated, _ = d.refreshFiltersIntl(block, allow, force)
+
+	return updated
+}
+
+// listsToUpdate returns the slice of filter lists that could be updated.
+func (d *DNSFilter) listsToUpdate(filters *[]FilterYAML, force bool) (toUpd []FilterYAML) {
+	now := time.Now()
+
+	d.filtersMu.RLock()
+	defer d.filtersMu.RUnlock()
+
+	for i := range *filters {
+		flt := &(*filters)[i] // otherwise we will be operating on a copy
+		log.Debug("checking list at index %d: %v", i, flt)
+
+		if !flt.Enabled {
+			continue
+		}
+
+		if !force {
+			exp := flt.LastUpdated.Add(time.Duration(d.FiltersUpdateIntervalHours) * time.Hour)
+			if now.Before(exp) {
+				continue
+			}
+		}
+
+		toUpd = append(toUpd, FilterYAML{
+			Filter: Filter{
+				ID: flt.ID,
+			},
+			URL:      flt.URL,
+			Name:     flt.Name,
+			checksum: flt.checksum,
+		})
+	}
+
+	return toUpd
+}
+
+func (d *DNSFilter) refreshFiltersArray(filters *[]FilterYAML, force bool) (int, []FilterYAML, []bool, bool) {
 	var updateFlags []bool // 'true' if filter data has changed
 
-	now := time.Now()
-	config.RLock()
-	for i := range *filters {
-		f := &(*filters)[i] // otherwise we will be operating on a copy
-
-		if !f.Enabled {
-			continue
-		}
-
-		expireTime := f.LastUpdated.Unix() + int64(config.DNS.FiltersUpdateIntervalHours)*60*60
-		if !force && expireTime > now.Unix() {
-			continue
-		}
-
-		var uf filter
-		uf.ID = f.ID
-		uf.URL = f.URL
-		uf.Name = f.Name
-		uf.checksum = f.checksum
-		updateFilters = append(updateFilters, uf)
-	}
-	config.RUnlock()
-
+	updateFilters := d.listsToUpdate(filters, force)
 	if len(updateFilters) == 0 {
 		return 0, nil, nil, false
 	}
@@ -316,7 +316,7 @@ func (f *Filtering) refreshFiltersArray(filters *[]filter, force bool) (int, []f
 	nfail := 0
 	for i := range updateFilters {
 		uf := &updateFilters[i]
-		updated, err := f.update(uf)
+		updated, err := d.update(uf)
 		updateFlags = append(updateFlags, updated)
 		if err != nil {
 			nfail++
@@ -334,7 +334,7 @@ func (f *Filtering) refreshFiltersArray(filters *[]filter, force bool) (int, []f
 		uf := &updateFilters[i]
 		updated := updateFlags[i]
 
-		config.Lock()
+		d.filtersMu.Lock()
 		for k := range *filters {
 			f := &(*filters)[k]
 			if f.ID != uf.ID || f.URL != uf.URL {
@@ -352,20 +352,14 @@ func (f *Filtering) refreshFiltersArray(filters *[]filter, force bool) (int, []f
 			f.checksum = uf.checksum
 			updateCount++
 		}
-		config.Unlock()
+		d.filtersMu.Unlock()
 	}
 
 	return updateCount, updateFilters, updateFlags, false
 }
 
-const (
-	filterRefreshForce      = 1 // ignore last file modification date
-	filterRefreshAllowlists = 2 // update allow-lists
-	filterRefreshBlocklists = 4 // update block-lists
-)
-
-// refreshFiltersIfNecessary checks filters and updates them if necessary.  If
-// force is true, it ignores the filter.LastUpdated field value.
+// refreshFiltersIntl checks filters and updates them if necessary.  If force is
+// true, it ignores the filter.LastUpdated field value.
 //
 // Algorithm:
 //
@@ -378,53 +372,49 @@ const (
 //     that this method works only on Unix systems.  On Windows, don't pass
 //     files to filtering, pass the whole data.
 //
-// refreshFiltersIfNecessary returns the number of updated filters.  It also
-// returns true if there was a network error and nothing could be updated.
+// refreshFiltersIntl returns the number of updated filters.  It also returns
+// true if there was a network error and nothing could be updated.
 //
 // TODO(a.garipov, e.burkov): What the hell?
-func (f *Filtering) refreshFiltersIfNecessary(flags int) (int, bool) {
-	log.Debug("Filters: updating...")
+func (d *DNSFilter) refreshFiltersIntl(block, allow, force bool) (int, bool) {
+	log.Debug("filtering: updating...")
 
-	updateCount := 0
-	var updateFilters []filter
-	var updateFlags []bool
-	netError := false
-	netErrorW := false
-	force := false
-	if (flags & filterRefreshForce) != 0 {
-		force = true
+	updNum := 0
+	var lists []FilterYAML
+	var toUpd []bool
+	isNetErr := false
+
+	if block {
+		updNum, lists, toUpd, isNetErr = d.refreshFiltersArray(&d.Filters, force)
 	}
-	if (flags & filterRefreshBlocklists) != 0 {
-		updateCount, updateFilters, updateFlags, netError = f.refreshFiltersArray(&config.Filters, force)
+	if allow {
+		updNumAl, listsAl, toUpdAl, isNetErrAl := d.refreshFiltersArray(&d.WhitelistFilters, force)
+
+		updNum += updNumAl
+		lists = append(lists, listsAl...)
+		toUpd = append(toUpd, toUpdAl...)
+		isNetErr = isNetErr || isNetErrAl
 	}
-	if (flags & filterRefreshAllowlists) != 0 {
-		updateCountW := 0
-		var updateFiltersW []filter
-		var updateFlagsW []bool
-		updateCountW, updateFiltersW, updateFlagsW, netErrorW = f.refreshFiltersArray(&config.WhitelistFilters, force)
-		updateCount += updateCountW
-		updateFilters = append(updateFilters, updateFiltersW...)
-		updateFlags = append(updateFlags, updateFlagsW...)
-	}
-	if netError && netErrorW {
+	if isNetErr {
 		return 0, true
 	}
 
-	if updateCount != 0 {
-		enableFilters(false)
+	if updNum != 0 {
+		d.EnableFilters(false)
 
-		for i := range updateFilters {
-			uf := &updateFilters[i]
-			updated := updateFlags[i]
+		for i := range lists {
+			uf := &lists[i]
+			updated := toUpd[i]
 			if !updated {
 				continue
 			}
-			_ = os.Remove(uf.Path() + ".old")
+			_ = os.Remove(uf.Path(d.DataDir) + ".old")
 		}
 	}
 
-	log.Debug("Filters: update finished")
-	return updateCount, false
+	log.Debug("filtering: update finished")
+
+	return updNum, false
 }
 
 // Allows printable UTF-8 text with CR, LF, TAB characters
@@ -440,7 +430,7 @@ func isPrintableText(data []byte, len int) bool {
 }
 
 // A helper function that parses filter contents and returns a number of rules and a filter name (if there's any)
-func (f *Filtering) parseFilterContents(file io.Reader) (int, uint32, string) {
+func (d *DNSFilter) parseFilterContents(file io.Reader) (int, uint32, string) {
 	rulesCount := 0
 	name := ""
 	seenTitle := false
@@ -455,7 +445,7 @@ func (f *Filtering) parseFilterContents(file io.Reader) (int, uint32, string) {
 		if len(line) == 0 {
 			//
 		} else if line[0] == '!' {
-			m := f.filterTitleRegexp.FindAllStringSubmatch(line, -1)
+			m := d.filterTitleRegexp.FindAllStringSubmatch(line, -1)
 			if len(m) > 0 && len(m[0]) >= 2 && !seenTitle {
 				name = m[0][1]
 				seenTitle = true
@@ -476,11 +466,11 @@ func (f *Filtering) parseFilterContents(file io.Reader) (int, uint32, string) {
 }
 
 // Perform upgrade on a filter and update LastUpdated value
-func (f *Filtering) update(filter *filter) (bool, error) {
-	b, err := f.updateIntl(filter)
+func (d *DNSFilter) update(filter *FilterYAML) (bool, error) {
+	b, err := d.updateIntl(filter)
 	filter.LastUpdated = time.Now()
 	if !b {
-		e := os.Chtimes(filter.Path(), filter.LastUpdated, filter.LastUpdated)
+		e := os.Chtimes(filter.Path(d.DataDir), filter.LastUpdated, filter.LastUpdated)
 		if e != nil {
 			log.Error("os.Chtimes(): %v", e)
 		}
@@ -488,7 +478,7 @@ func (f *Filtering) update(filter *filter) (bool, error) {
 	return b, err
 }
 
-func (f *Filtering) read(reader io.Reader, tmpFile *os.File, filter *filter) (int, error) {
+func (d *DNSFilter) read(reader io.Reader, tmpFile *os.File, filter *FilterYAML) (int, error) {
 	htmlTest := true
 	firstChunk := make([]byte, 4*1024)
 	firstChunkLen := 0
@@ -539,20 +529,20 @@ func (f *Filtering) read(reader io.Reader, tmpFile *os.File, filter *filter) (in
 // finalizeUpdate closes and gets rid of temporary file f with filter's content
 // according to updated.  It also saves new values of flt's name, rules number
 // and checksum if sucсeeded.
-func finalizeUpdate(
-	f *os.File,
-	flt *filter,
+func (d *DNSFilter) finalizeUpdate(
+	file *os.File,
+	flt *FilterYAML,
 	updated bool,
 	name string,
 	rnum int,
 	cs uint32,
 ) (err error) {
-	tmpFileName := f.Name()
+	tmpFileName := file.Name()
 
 	// Close the file before renaming it because it's required on Windows.
 	//
 	// See https://github.com/adguardTeam/adGuardHome/issues/1553.
-	if err = f.Close(); err != nil {
+	if err = file.Close(); err != nil {
 		return fmt.Errorf("closing temporary file: %w", err)
 	}
 
@@ -562,9 +552,9 @@ func finalizeUpdate(
 		return os.Remove(tmpFileName)
 	}
 
-	log.Printf("saving filter %d contents to: %s", flt.ID, flt.Path())
+	log.Printf("saving filter %d contents to: %s", flt.ID, flt.Path(d.DataDir))
 
-	if err = os.Rename(tmpFileName, flt.Path()); err != nil {
+	if err = os.Rename(tmpFileName, flt.Path(d.DataDir)); err != nil {
 		return errors.WithDeferred(err, os.Remove(tmpFileName))
 	}
 
@@ -578,12 +568,12 @@ func finalizeUpdate(
 // processUpdate copies filter's content from src to dst and returns the name,
 // rules number, and checksum for it.  It also returns the number of bytes read
 // from src.
-func (f *Filtering) processUpdate(
+func (d *DNSFilter) processUpdate(
 	src io.Reader,
 	dst *os.File,
-	flt *filter,
+	flt *FilterYAML,
 ) (name string, rnum int, cs uint32, n int, err error) {
-	if n, err = f.read(src, dst, flt); err != nil {
+	if n, err = d.read(src, dst, flt); err != nil {
 		return "", 0, 0, 0, err
 	}
 
@@ -591,14 +581,14 @@ func (f *Filtering) processUpdate(
 		return "", 0, 0, 0, err
 	}
 
-	rnum, cs, name = f.parseFilterContents(dst)
+	rnum, cs, name = d.parseFilterContents(dst)
 
 	return name, rnum, cs, n, nil
 }
 
 // updateIntl updates the flt rewriting it's actual file.  It returns true if
 // the actual update has been performed.
-func (f *Filtering) updateIntl(flt *filter) (ok bool, err error) {
+func (d *DNSFilter) updateIntl(flt *FilterYAML) (ok bool, err error) {
 	log.Tracef("downloading update for filter %d from %s", flt.ID, flt.URL)
 
 	var name string
@@ -606,12 +596,12 @@ func (f *Filtering) updateIntl(flt *filter) (ok bool, err error) {
 	var cs uint32
 
 	var tmpFile *os.File
-	tmpFile, err = os.CreateTemp(filepath.Join(Context.getDataDir(), filterDir), "")
+	tmpFile, err = os.CreateTemp(filepath.Join(d.DataDir, filterDir), "")
 	if err != nil {
 		return false, err
 	}
 	defer func() {
-		err = errors.WithDeferred(err, finalizeUpdate(tmpFile, flt, ok, name, rnum, cs))
+		err = errors.WithDeferred(err, d.finalizeUpdate(tmpFile, flt, ok, name, rnum, cs))
 		ok = ok && err == nil
 		if ok {
 			log.Printf("updated filter %d: %d bytes, %d rules", flt.ID, n, rnum)
@@ -638,7 +628,7 @@ func (f *Filtering) updateIntl(flt *filter) (ok bool, err error) {
 		r = file
 	} else {
 		var resp *http.Response
-		resp, err = Context.client.Get(flt.URL)
+		resp, err = d.HTTPClient.Get(flt.URL)
 		if err != nil {
 			log.Printf("requesting filter from %s, skip: %s", flt.URL, err)
 
@@ -655,16 +645,16 @@ func (f *Filtering) updateIntl(flt *filter) (ok bool, err error) {
 		r = resp.Body
 	}
 
-	name, rnum, cs, n, err = f.processUpdate(r, tmpFile, flt)
+	name, rnum, cs, n, err = d.processUpdate(r, tmpFile, flt)
 
 	return cs != flt.checksum, err
 }
 
 // loads filter contents from the file in dataDir
-func (f *Filtering) load(filter *filter) (err error) {
-	filterFilePath := filter.Path()
+func (d *DNSFilter) load(filter *FilterYAML) (err error) {
+	filterFilePath := filter.Path(d.DataDir)
 
-	log.Tracef("filtering: loading filter %d contents to: %s", filter.ID, filterFilePath)
+	log.Tracef("filtering: loading filter %d from %s", filter.ID, filterFilePath)
 
 	file, err := os.Open(filterFilePath)
 	if errors.Is(err, os.ErrNotExist) {
@@ -682,7 +672,7 @@ func (f *Filtering) load(filter *filter) (err error) {
 
 	log.Tracef("filtering: File %s, id %d, length %d", filterFilePath, filter.ID, st.Size())
 
-	rulesCount, checksum, _ := f.parseFilterContents(file)
+	rulesCount, checksum, _ := d.parseFilterContents(file)
 
 	filter.RulesCount = rulesCount
 	filter.checksum = checksum
@@ -691,56 +681,45 @@ func (f *Filtering) load(filter *filter) (err error) {
 	return nil
 }
 
-// Clear filter rules
-func (filter *filter) unload() {
-	filter.RulesCount = 0
-	filter.checksum = 0
+func (d *DNSFilter) EnableFilters(async bool) {
+	d.filtersMu.RLock()
+	defer d.filtersMu.RUnlock()
+
+	d.enableFiltersLocked(async)
 }
 
-// Path to the filter contents
-func (filter *filter) Path() string {
-	return filepath.Join(Context.getDataDir(), filterDir, strconv.FormatInt(filter.ID, 10)+".txt")
-}
-
-func enableFilters(async bool) {
-	config.RLock()
-	defer config.RUnlock()
-
-	enableFiltersLocked(async)
-}
-
-func enableFiltersLocked(async bool) {
-	filters := []filtering.Filter{{
-		ID:   filtering.CustomListID,
-		Data: []byte(strings.Join(config.UserRules, "\n")),
+func (d *DNSFilter) enableFiltersLocked(async bool) {
+	filters := []Filter{{
+		ID:   CustomListID,
+		Data: []byte(strings.Join(d.UserRules, "\n")),
 	}}
 
-	for _, filter := range config.Filters {
+	for _, filter := range d.Filters {
 		if !filter.Enabled {
 			continue
 		}
 
-		filters = append(filters, filtering.Filter{
+		filters = append(filters, Filter{
 			ID:       filter.ID,
-			FilePath: filter.Path(),
+			FilePath: filter.Path(d.DataDir),
 		})
 	}
 
-	var allowFilters []filtering.Filter
-	for _, filter := range config.WhitelistFilters {
+	var allowFilters []Filter
+	for _, filter := range d.WhitelistFilters {
 		if !filter.Enabled {
 			continue
 		}
 
-		allowFilters = append(allowFilters, filtering.Filter{
+		allowFilters = append(allowFilters, Filter{
 			ID:       filter.ID,
-			FilePath: filter.Path(),
+			FilePath: filter.Path(d.DataDir),
 		})
 	}
 
-	if err := Context.dnsFilter.SetFilters(filters, allowFilters, async); err != nil {
+	if err := d.SetFilters(filters, allowFilters, async); err != nil {
 		log.Debug("enabling filters: %s", err)
 	}
 
-	Context.dnsFilter.SetEnabled(config.DNS.FilteringEnabled)
+	d.SetEnabled(d.FilteringEnabled)
 }

internal/filtering/filter_test.go

@@ -1,4 +1,4 @@
-package home
+package filtering
 
 import (
 	"io/fs"
@@ -51,15 +51,17 @@ func TestFilters(t *testing.T) {
 
 	l := testStartFilterListener(t, &fltContent)
 
-	Context = homeContext{
-		workDir: t.TempDir(),
-		client: &http.Client{
+	tempDir := t.TempDir()
+
+	filters, err := New(&Config{
+		DataDir: tempDir,
+		HTTPClient: &http.Client{
 			Timeout: 5 * time.Second,
 		},
-	}
-	Context.filters.Init()
+	}, nil)
+	require.NoError(t, err)
 
-	f := &filter{
+	f := &FilterYAML{
 		URL: (&url.URL{
 			Scheme: "http",
 			Host: (&netutil.IPPort{
@@ -71,21 +73,22 @@ func TestFilters(t *testing.T) {
 	}
 
 	updateAndAssert := func(t *testing.T, want require.BoolAssertionFunc, wantRulesCount int) {
-		ok, err := Context.filters.update(f)
+		var ok bool
+		ok, err = filters.update(f)
 		require.NoError(t, err)
 		want(t, ok)
 
 		assert.Equal(t, wantRulesCount, f.RulesCount)
 
 		var dir []fs.DirEntry
-		dir, err = os.ReadDir(filepath.Join(Context.getDataDir(), filterDir))
+		dir, err = os.ReadDir(filepath.Join(tempDir, filterDir))
 		require.NoError(t, err)
 
 		assert.Len(t, dir, 1)
 
-		require.FileExists(t, f.Path())
+		require.FileExists(t, f.Path(tempDir))
 
-		err = Context.filters.load(f)
+		err = filters.load(f)
 		require.NoError(t, err)
 	}
 
@@ -105,11 +108,9 @@ func TestFilters(t *testing.T) {
 	})
 
 	t.Run("load_unload", func(t *testing.T) {
-		err := Context.filters.load(f)
+		err = filters.load(f)
 		require.NoError(t, err)
 
 		f.unload()
 	})
-
-	require.NoError(t, os.Remove(f.Path()))
 }

internal/filtering/filtering.go

@@ -6,7 +6,10 @@ import (
 	"fmt"
 	"io/fs"
 	"net"
+	"net/http"
 	"os"
+	"path/filepath"
+	"regexp"
 	"runtime"
 	"runtime/debug"
 	"strings"
@@ -24,6 +27,7 @@ import (
 	"github.com/AdguardTeam/urlfilter/filterlist"
 	"github.com/AdguardTeam/urlfilter/rules"
 	"github.com/miekg/dns"
+	"golang.org/x/exp/slices"
 )
 
 // The IDs of built-in filter lists.
@@ -69,8 +73,13 @@ type Config struct {
 	// enabled is used to be returned within Settings.
 	//
 	// It is of type uint32 to be accessed by atomic.
+	//
+	// TODO(e.burkov):  Use atomic.Bool in Go 1.19.
 	enabled uint32
 
+	FilteringEnabled           bool   `yaml:"filtering_enabled"`       // whether or not use filter lists
+	FiltersUpdateIntervalHours uint32 `yaml:"filters_update_interval"` // time period to update filters (in hours)
+
 	ParentalEnabled     bool `yaml:"parental_enabled"`
 	SafeSearchEnabled   bool `yaml:"safesearch_enabled"`
 	SafeBrowsingEnabled bool `yaml:"safebrowsing_enabled"`
@@ -98,6 +107,24 @@ type Config struct {
 
 	// CustomResolver is the resolver used by DNSFilter.
 	CustomResolver Resolver `yaml:"-"`
+
+	// HTTPClient is the client to use for updating the remote filters.
+	HTTPClient *http.Client `yaml:"-"`
+
+	// DataDir is used to store filters' contents.
+	DataDir string `yaml:"-"`
+
+	// filtersMu protects filter lists.
+	filtersMu *sync.RWMutex
+
+	// Filters are the blocking filter lists.
+	Filters []FilterYAML `yaml:"-"`
+
+	// WhitelistFilters are the allowing filter lists.
+	WhitelistFilters []FilterYAML `yaml:"-"`
+
+	// UserRules is the global list of custom rules.
+	UserRules []string `yaml:"-"`
 }
 
 // LookupStats store stats collected during safebrowsing or parental checks
@@ -128,11 +155,13 @@ type hostChecker struct {
 
 // DNSFilter matches hostnames and DNS requests against filtering rules.
 type DNSFilter struct {
-	rulesStorage         *filterlist.RuleStorage
-	filteringEngine      *urlfilter.DNSEngine
+	rulesStorage    *filterlist.RuleStorage
+	filteringEngine *urlfilter.DNSEngine
+
 	rulesStorageAllow    *filterlist.RuleStorage
 	filteringEngineAllow *urlfilter.DNSEngine
-	engineLock           sync.RWMutex
+
+	engineLock sync.RWMutex
 
 	parentalServer       string // access via methods
 	safeBrowsingServer   string // access via methods
@@ -156,6 +185,12 @@ type DNSFilter struct {
 	// TODO(e.burkov): Use upstream that configured in dnsforward instead.
 	resolver Resolver
 
+	refreshLock *sync.Mutex
+
+	// filterTitleRegexp is the regular expression to retrieve a name of a
+	// filter list.
+	filterTitleRegexp *regexp.Regexp
+
 	hostCheckers []hostChecker
 }
 
@@ -168,7 +203,7 @@ type Filter struct {
 	Data []byte `yaml:"-"`
 
 	// ID is automatically assigned when filter is added using nextFilterID.
-	ID int64
+	ID int64 `yaml:"id"`
 }
 
 // Reason holds an enum detailing why it was filtered or not filtered
@@ -245,15 +280,7 @@ func (r Reason) String() string {
 }
 
 // In returns true if reasons include r.
-func (r Reason) In(reasons ...Reason) (ok bool) {
-	for _, reason := range reasons {
-		if r == reason {
-			return true
-		}
-	}
-
-	return false
-}
+func (r Reason) In(reasons ...Reason) (ok bool) { return slices.Contains(reasons, r) }
 
 // SetEnabled sets the status of the *DNSFilter.
 func (d *DNSFilter) SetEnabled(enabled bool) {
@@ -261,6 +288,7 @@ func (d *DNSFilter) SetEnabled(enabled bool) {
 	if enabled {
 		i = 1
 	}
+
 	atomic.StoreUint32(&d.enabled, uint32(i))
 }
 
@@ -279,11 +307,20 @@ func (d *DNSFilter) GetConfig() (s Settings) {
 
 // WriteDiskConfig - write configuration
 func (d *DNSFilter) WriteDiskConfig(c *Config) {
-	d.confLock.Lock()
-	defer d.confLock.Unlock()
+	func() {
+		d.confLock.Lock()
+		defer d.confLock.Unlock()
 
-	*c = d.Config
-	c.Rewrites = cloneRewrites(c.Rewrites)
+		*c = d.Config
+		c.Rewrites = cloneRewrites(c.Rewrites)
+	}()
+
+	d.filtersMu.RLock()
+	defer d.filtersMu.RUnlock()
+
+	c.Filters = slices.Clone(d.Filters)
+	c.WhitelistFilters = slices.Clone(d.WhitelistFilters)
+	c.UserRules = slices.Clone(d.UserRules)
 }
 
 // cloneRewrites returns a deep copy of entries.
@@ -309,6 +346,8 @@ func (d *DNSFilter) SetFilters(blockFilters, allowFilters []Filter, async bool)
 		}
 
 		d.filtersInitializerLock.Lock() // prevent multiple writers from adding more than 1 task
+		defer d.filtersInitializerLock.Unlock()
+
 		// remove all pending tasks
 		stop := false
 		for !stop {
@@ -321,7 +360,6 @@ func (d *DNSFilter) SetFilters(blockFilters, allowFilters []Filter, async bool)
 		}
 
 		d.filtersInitializerChan <- params
-		d.filtersInitializerLock.Unlock()
 		return nil
 	}
 
@@ -350,22 +388,19 @@ func (d *DNSFilter) filtersInitializer() {
 func (d *DNSFilter) Close() {
 	d.engineLock.Lock()
 	defer d.engineLock.Unlock()
+
 	d.reset()
 }
 
 func (d *DNSFilter) reset() {
-	var err error
-
 	if d.rulesStorage != nil {
-		err = d.rulesStorage.Close()
-		if err != nil {
+		if err := d.rulesStorage.Close(); err != nil {
 			log.Error("filtering: rulesStorage.Close: %s", err)
 		}
 	}
 
 	if d.rulesStorageAllow != nil {
-		err = d.rulesStorageAllow.Close()
-		if err != nil {
+		if err := d.rulesStorageAllow.Close(); err != nil {
 			log.Error("filtering: rulesStorageAllow.Close: %s", err)
 		}
 	}
@@ -885,29 +920,30 @@ func InitModule() {
 	initBlockedServices()
 }
 
-// New creates properly initialized DNS Filter that is ready to be used.
-func New(c *Config, blockFilters []Filter) (d *DNSFilter) {
+// New creates properly initialized DNS Filter that is ready to be used.  c must
+// be non-nil.
+func New(c *Config, blockFilters []Filter) (d *DNSFilter, err error) {
 	d = &DNSFilter{
-		resolver: net.DefaultResolver,
+		resolver:          net.DefaultResolver,
+		refreshLock:       &sync.Mutex{},
+		filterTitleRegexp: regexp.MustCompile(`^! Title: +(.*)$`),
 	}
-	if c != nil {
 
-		d.safebrowsingCache = cache.New(cache.Config{
-			EnableLRU: true,
-			MaxSize:   c.SafeBrowsingCacheSize,
-		})
-		d.safeSearchCache = cache.New(cache.Config{
-			EnableLRU: true,
-			MaxSize:   c.SafeSearchCacheSize,
-		})
-		d.parentalCache = cache.New(cache.Config{
-			EnableLRU: true,
-			MaxSize:   c.ParentalCacheSize,
-		})
+	d.safebrowsingCache = cache.New(cache.Config{
+		EnableLRU: true,
+		MaxSize:   c.SafeBrowsingCacheSize,
+	})
+	d.safeSearchCache = cache.New(cache.Config{
+		EnableLRU: true,
+		MaxSize:   c.SafeSearchCacheSize,
+	})
+	d.parentalCache = cache.New(cache.Config{
+		EnableLRU: true,
+		MaxSize:   c.ParentalCacheSize,
+	})
 
-		if c.CustomResolver != nil {
-			d.resolver = c.CustomResolver
-		}
+	if r := c.CustomResolver; r != nil {
+		d.resolver = r
 	}
 
 	d.hostCheckers = []hostChecker{{
@@ -930,27 +966,26 @@ func New(c *Config, blockFilters []Filter) (d *DNSFilter) {
 		name:  "safe search",
 	}}
 
-	err := d.initSecurityServices()
-	if err != nil {
-		log.Error("filtering: initialize services: %s", err)
+	defer func() { err = errors.Annotate(err, "filtering: %w") }()
 
-		return nil
+	err = d.initSecurityServices()
+	if err != nil {
+		return nil, fmt.Errorf("initializing services: %s", err)
 	}
 
-	if c != nil {
-		d.Config = *c
-		err = d.prepareRewrites()
-		if err != nil {
-			log.Error("rewrites: preparing: %s", err)
+	d.Config = *c
+	d.filtersMu = &sync.RWMutex{}
 
-			return nil
-		}
+	err = d.prepareRewrites()
+	if err != nil {
+		return nil, fmt.Errorf("rewrites: preparing: %s", err)
 	}
 
 	bsvcs := []string{}
 	for _, s := range d.BlockedServices {
 		if !BlockedSvcKnown(s) {
 			log.Debug("skipping unknown blocked-service %q", s)
+
 			continue
 		}
 		bsvcs = append(bsvcs, s)
@@ -960,13 +995,24 @@ func New(c *Config, blockFilters []Filter) (d *DNSFilter) {
 	if blockFilters != nil {
 		err = d.initFiltering(nil, blockFilters)
 		if err != nil {
-			log.Error("Can't initialize filtering subsystem: %s", err)
 			d.Close()
-			return nil
+
+			return nil, fmt.Errorf("initializing filtering subsystem: %s", err)
 		}
 	}
 
-	return d
+	_ = os.MkdirAll(filepath.Join(d.DataDir, filterDir), 0o755)
+
+	d.loadFilters(d.Filters)
+	d.loadFilters(d.WhitelistFilters)
+
+	d.Filters = deduplicateFilters(d.Filters)
+	d.WhitelistFilters = deduplicateFilters(d.WhitelistFilters)
+
+	updateUniqueFilterID(d.Filters)
+	updateUniqueFilterID(d.WhitelistFilters)
+
+	return d, nil
 }
 
 // Start - start the module:
@@ -976,9 +1022,10 @@ func (d *DNSFilter) Start() {
 	d.filtersInitializerChan = make(chan filtersInitializerParams, 1)
 	go d.filtersInitializer()
 
-	if d.Config.HTTPRegister != nil { // for tests
-		d.registerSecurityHandlers()
-		d.registerRewritesHandlers()
-		d.registerBlockedServicesHandlers()
-	}
+	d.RegisterFilteringHandlers()
+
+	// Here we should start updating filters,
+	//  but currently we can't wake up the periodic task to do so.
+	// So for now we just start this periodic task from here.
+	go d.periodicallyRefreshFilters()
 }

internal/filtering/filtering_test.go

@@ -26,10 +26,6 @@ const (
 	pcBlocked = "pornhub.com"
 )
 
-var setts = Settings{
-	ProtectionEnabled: true,
-}
-
 // Helpers.
 
 func purgeCaches(d *DNSFilter) {
@@ -44,8 +40,8 @@ func purgeCaches(d *DNSFilter) {
 	}
 }
 
-func newForTest(t testing.TB, c *Config, filters []Filter) *DNSFilter {
-	setts = Settings{
+func newForTest(t testing.TB, c *Config, filters []Filter) (f *DNSFilter, setts *Settings) {
+	setts = &Settings{
 		ProtectionEnabled: true,
 		FilteringEnabled:  true,
 	}
@@ -57,26 +53,31 @@ func newForTest(t testing.TB, c *Config, filters []Filter) *DNSFilter {
 		setts.SafeSearchEnabled = c.SafeSearchEnabled
 		setts.SafeBrowsingEnabled = c.SafeBrowsingEnabled
 		setts.ParentalEnabled = c.ParentalEnabled
+	} else {
+		// It must not be nil.
+		c = &Config{}
 	}
-	d := New(c, filters)
-	purgeCaches(d)
+	f, err := New(c, filters)
+	require.NoError(t, err)
 
-	return d
+	purgeCaches(f)
+
+	return f, setts
 }
 
-func (d *DNSFilter) checkMatch(t *testing.T, hostname string) {
+func (d *DNSFilter) checkMatch(t *testing.T, hostname string, setts *Settings) {
 	t.Helper()
 
-	res, err := d.CheckHost(hostname, dns.TypeA, &setts)
+	res, err := d.CheckHost(hostname, dns.TypeA, setts)
 	require.NoErrorf(t, err, "host %q", hostname)
 
 	assert.Truef(t, res.IsFiltered, "host %q", hostname)
 }
 
-func (d *DNSFilter) checkMatchIP(t *testing.T, hostname, ip string, qtype uint16) {
+func (d *DNSFilter) checkMatchIP(t *testing.T, hostname, ip string, qtype uint16, setts *Settings) {
 	t.Helper()
 
-	res, err := d.CheckHost(hostname, qtype, &setts)
+	res, err := d.CheckHost(hostname, qtype, setts)
 	require.NoErrorf(t, err, "host %q", hostname, err)
 	require.NotEmpty(t, res.Rules, "host %q", hostname)
 
@@ -88,10 +89,10 @@ func (d *DNSFilter) checkMatchIP(t *testing.T, hostname, ip string, qtype uint16
 	assert.Equalf(t, ip, r.IP.String(), "host %q", hostname)
 }
 
-func (d *DNSFilter) checkMatchEmpty(t *testing.T, hostname string) {
+func (d *DNSFilter) checkMatchEmpty(t *testing.T, hostname string, setts *Settings) {
 	t.Helper()
 
-	res, err := d.CheckHost(hostname, dns.TypeA, &setts)
+	res, err := d.CheckHost(hostname, dns.TypeA, setts)
 	require.NoErrorf(t, err, "host %q", hostname)
 
 	assert.Falsef(t, res.IsFiltered, "host %q", hostname)
@@ -111,19 +112,19 @@ func TestEtcHostsMatching(t *testing.T) {
 	filters := []Filter{{
 		ID: 0, Data: []byte(text),
 	}}
-	d := newForTest(t, nil, filters)
+	d, setts := newForTest(t, nil, filters)
 	t.Cleanup(d.Close)
 
-	d.checkMatchIP(t, "google.com", addr, dns.TypeA)
-	d.checkMatchIP(t, "www.google.com", addr, dns.TypeA)
-	d.checkMatchEmpty(t, "subdomain.google.com")
-	d.checkMatchEmpty(t, "example.org")
+	d.checkMatchIP(t, "google.com", addr, dns.TypeA, setts)
+	d.checkMatchIP(t, "www.google.com", addr, dns.TypeA, setts)
+	d.checkMatchEmpty(t, "subdomain.google.com", setts)
+	d.checkMatchEmpty(t, "example.org", setts)
 
 	// IPv4 match.
-	d.checkMatchIP(t, "block.com", "0.0.0.0", dns.TypeA)
+	d.checkMatchIP(t, "block.com", "0.0.0.0", dns.TypeA, setts)
 
 	// Empty IPv6.
-	res, err := d.CheckHost("block.com", dns.TypeAAAA, &setts)
+	res, err := d.CheckHost("block.com", dns.TypeAAAA, setts)
 	require.NoError(t, err)
 
 	assert.True(t, res.IsFiltered)
@@ -134,10 +135,10 @@ func TestEtcHostsMatching(t *testing.T) {
 	assert.Empty(t, res.Rules[0].IP)
 
 	// IPv6 match.
-	d.checkMatchIP(t, "ipv6.com", addr6, dns.TypeAAAA)
+	d.checkMatchIP(t, "ipv6.com", addr6, dns.TypeAAAA, setts)
 
 	// Empty IPv4.
-	res, err = d.CheckHost("ipv6.com", dns.TypeA, &setts)
+	res, err = d.CheckHost("ipv6.com", dns.TypeA, setts)
 	require.NoError(t, err)
 
 	assert.True(t, res.IsFiltered)
@@ -148,7 +149,7 @@ func TestEtcHostsMatching(t *testing.T) {
 	assert.Empty(t, res.Rules[0].IP)
 
 	// Two IPv4, both must be returned.
-	res, err = d.CheckHost("host2", dns.TypeA, &setts)
+	res, err = d.CheckHost("host2", dns.TypeA, setts)
 	require.NoError(t, err)
 
 	assert.True(t, res.IsFiltered)
@@ -159,7 +160,7 @@ func TestEtcHostsMatching(t *testing.T) {
 	assert.Equal(t, res.Rules[1].IP, net.IP{0, 0, 0, 2})
 
 	// One IPv6 address.
-	res, err = d.CheckHost("host2", dns.TypeAAAA, &setts)
+	res, err = d.CheckHost("host2", dns.TypeAAAA, setts)
 	require.NoError(t, err)
 
 	assert.True(t, res.IsFiltered)
@@ -176,27 +177,27 @@ func TestSafeBrowsing(t *testing.T) {
 	aghtest.ReplaceLogWriter(t, logOutput)
 	aghtest.ReplaceLogLevel(t, log.DEBUG)
 
-	d := newForTest(t, &Config{SafeBrowsingEnabled: true}, nil)
+	d, setts := newForTest(t, &Config{SafeBrowsingEnabled: true}, nil)
 	t.Cleanup(d.Close)
 
 	d.SetSafeBrowsingUpstream(aghtest.NewBlockUpstream(sbBlocked, true))
-	d.checkMatch(t, sbBlocked)
+	d.checkMatch(t, sbBlocked, setts)
 
 	require.Contains(t, logOutput.String(), fmt.Sprintf("safebrowsing lookup for %q", sbBlocked))
 
-	d.checkMatch(t, "test."+sbBlocked)
-	d.checkMatchEmpty(t, "yandex.ru")
-	d.checkMatchEmpty(t, pcBlocked)
+	d.checkMatch(t, "test."+sbBlocked, setts)
+	d.checkMatchEmpty(t, "yandex.ru", setts)
+	d.checkMatchEmpty(t, pcBlocked, setts)
 
 	// Cached result.
 	d.safeBrowsingServer = "127.0.0.1"
-	d.checkMatch(t, sbBlocked)
-	d.checkMatchEmpty(t, pcBlocked)
+	d.checkMatch(t, sbBlocked, setts)
+	d.checkMatchEmpty(t, pcBlocked, setts)
 	d.safeBrowsingServer = defaultSafebrowsingServer
 }
 
 func TestParallelSB(t *testing.T) {
-	d := newForTest(t, &Config{SafeBrowsingEnabled: true}, nil)
+	d, setts := newForTest(t, &Config{SafeBrowsingEnabled: true}, nil)
 	t.Cleanup(d.Close)
 
 	d.SetSafeBrowsingUpstream(aghtest.NewBlockUpstream(sbBlocked, true))
@@ -205,10 +206,10 @@ func TestParallelSB(t *testing.T) {
 		for i := 0; i < 100; i++ {
 			t.Run(fmt.Sprintf("aaa%d", i), func(t *testing.T) {
 				t.Parallel()
-				d.checkMatch(t, sbBlocked)
-				d.checkMatch(t, "test."+sbBlocked)
-				d.checkMatchEmpty(t, "yandex.ru")
-				d.checkMatchEmpty(t, pcBlocked)
+				d.checkMatch(t, sbBlocked, setts)
+				d.checkMatch(t, "test."+sbBlocked, setts)
+				d.checkMatchEmpty(t, "yandex.ru", setts)
+				d.checkMatchEmpty(t, pcBlocked, setts)
 			})
 		}
 	})
@@ -217,7 +218,7 @@ func TestParallelSB(t *testing.T) {
 // Safe Search.
 
 func TestSafeSearch(t *testing.T) {
-	d := newForTest(t, &Config{SafeSearchEnabled: true}, nil)
+	d, _ := newForTest(t, &Config{SafeSearchEnabled: true}, nil)
 	t.Cleanup(d.Close)
 	val, ok := d.SafeSearchDomain("www.google.com")
 	require.True(t, ok)
@@ -226,7 +227,7 @@ func TestSafeSearch(t *testing.T) {
 }
 
 func TestCheckHostSafeSearchYandex(t *testing.T) {
-	d := newForTest(t, &Config{
+	d, setts := newForTest(t, &Config{
 		SafeSearchEnabled: true,
 	}, nil)
 	t.Cleanup(d.Close)
@@ -243,7 +244,7 @@ func TestCheckHostSafeSearchYandex(t *testing.T) {
 		"www.yandex.com",
 	} {
 		t.Run(strings.ToLower(host), func(t *testing.T) {
-			res, err := d.CheckHost(host, dns.TypeA, &setts)
+			res, err := d.CheckHost(host, dns.TypeA, setts)
 			require.NoError(t, err)
 
 			assert.True(t, res.IsFiltered)
@@ -258,7 +259,7 @@ func TestCheckHostSafeSearchYandex(t *testing.T) {
 
 func TestCheckHostSafeSearchGoogle(t *testing.T) {
 	resolver := &aghtest.TestResolver{}
-	d := newForTest(t, &Config{
+	d, setts := newForTest(t, &Config{
 		SafeSearchEnabled: true,
 		CustomResolver:    resolver,
 	}, nil)
@@ -277,7 +278,7 @@ func TestCheckHostSafeSearchGoogle(t *testing.T) {
 		"www.google.je",
 	} {
 		t.Run(host, func(t *testing.T) {
-			res, err := d.CheckHost(host, dns.TypeA, &setts)
+			res, err := d.CheckHost(host, dns.TypeA, setts)
 			require.NoError(t, err)
 
 			assert.True(t, res.IsFiltered)
@@ -291,12 +292,12 @@ func TestCheckHostSafeSearchGoogle(t *testing.T) {
 }
 
 func TestSafeSearchCacheYandex(t *testing.T) {
-	d := newForTest(t, nil, nil)
+	d, setts := newForTest(t, nil, nil)
 	t.Cleanup(d.Close)
 	const domain = "yandex.ru"
 
 	// Check host with disabled safesearch.
-	res, err := d.CheckHost(domain, dns.TypeA, &setts)
+	res, err := d.CheckHost(domain, dns.TypeA, setts)
 	require.NoError(t, err)
 
 	assert.False(t, res.IsFiltered)
@@ -305,10 +306,10 @@ func TestSafeSearchCacheYandex(t *testing.T) {
 
 	yandexIP := net.IPv4(213, 180, 193, 56)
 
-	d = newForTest(t, &Config{SafeSearchEnabled: true}, nil)
+	d, setts = newForTest(t, &Config{SafeSearchEnabled: true}, nil)
 	t.Cleanup(d.Close)
 
-	res, err = d.CheckHost(domain, dns.TypeA, &setts)
+	res, err = d.CheckHost(domain, dns.TypeA, setts)
 	require.NoError(t, err)
 
 	// For yandex we already know valid IP.
@@ -325,20 +326,20 @@ func TestSafeSearchCacheYandex(t *testing.T) {
 
 func TestSafeSearchCacheGoogle(t *testing.T) {
 	resolver := &aghtest.TestResolver{}
-	d := newForTest(t, &Config{
+	d, setts := newForTest(t, &Config{
 		CustomResolver: resolver,
 	}, nil)
 	t.Cleanup(d.Close)
 
 	const domain = "www.google.ru"
-	res, err := d.CheckHost(domain, dns.TypeA, &setts)
+	res, err := d.CheckHost(domain, dns.TypeA, setts)
 	require.NoError(t, err)
 
 	assert.False(t, res.IsFiltered)
 
 	require.Empty(t, res.Rules)
 
-	d = newForTest(t, &Config{SafeSearchEnabled: true}, nil)
+	d, setts = newForTest(t, &Config{SafeSearchEnabled: true}, nil)
 	t.Cleanup(d.Close)
 	d.resolver = resolver
 
@@ -358,7 +359,7 @@ func TestSafeSearchCacheGoogle(t *testing.T) {
 		}
 	}
 
-	res, err = d.CheckHost(domain, dns.TypeA, &setts)
+	res, err = d.CheckHost(domain, dns.TypeA, setts)
 	require.NoError(t, err)
 	require.Len(t, res.Rules, 1)
 
@@ -379,22 +380,22 @@ func TestParentalControl(t *testing.T) {
 	aghtest.ReplaceLogWriter(t, logOutput)
 	aghtest.ReplaceLogLevel(t, log.DEBUG)
 
-	d := newForTest(t, &Config{ParentalEnabled: true}, nil)
+	d, setts := newForTest(t, &Config{ParentalEnabled: true}, nil)
 	t.Cleanup(d.Close)
 
 	d.SetParentalUpstream(aghtest.NewBlockUpstream(pcBlocked, true))
-	d.checkMatch(t, pcBlocked)
+	d.checkMatch(t, pcBlocked, setts)
 	require.Contains(t, logOutput.String(), fmt.Sprintf("parental lookup for %q", pcBlocked))
 
-	d.checkMatch(t, "www."+pcBlocked)
-	d.checkMatchEmpty(t, "www.yandex.ru")
-	d.checkMatchEmpty(t, "yandex.ru")
-	d.checkMatchEmpty(t, "api.jquery.com")
+	d.checkMatch(t, "www."+pcBlocked, setts)
+	d.checkMatchEmpty(t, "www.yandex.ru", setts)
+	d.checkMatchEmpty(t, "yandex.ru", setts)
+	d.checkMatchEmpty(t, "api.jquery.com", setts)
 
 	// Test cached result.
 	d.parentalServer = "127.0.0.1"
-	d.checkMatch(t, pcBlocked)
-	d.checkMatchEmpty(t, "yandex.ru")
+	d.checkMatch(t, pcBlocked, setts)
+	d.checkMatchEmpty(t, "yandex.ru", setts)
 }
 
 // Filtering.
@@ -679,10 +680,10 @@ func TestMatching(t *testing.T) {
 	for _, tc := range testCases {
 		t.Run(fmt.Sprintf("%s-%s", tc.name, tc.host), func(t *testing.T) {
 			filters := []Filter{{ID: 0, Data: []byte(tc.rules)}}
-			d := newForTest(t, nil, filters)
+			d, setts := newForTest(t, nil, filters)
 			t.Cleanup(d.Close)
 
-			res, err := d.CheckHost(tc.host, tc.wantDNSType, &setts)
+			res, err := d.CheckHost(tc.host, tc.wantDNSType, setts)
 			require.NoError(t, err)
 
 			assert.Equalf(t, tc.wantIsFiltered, res.IsFiltered, "Hostname %s has wrong result (%v must be %v)", tc.host, res.IsFiltered, tc.wantIsFiltered)
@@ -705,7 +706,7 @@ func TestWhitelist(t *testing.T) {
 	whiteFilters := []Filter{{
 		ID: 0, Data: []byte(whiteRules),
 	}}
-	d := newForTest(t, nil, filters)
+	d, setts := newForTest(t, nil, filters)
 
 	err := d.SetFilters(filters, whiteFilters, false)
 	require.NoError(t, err)
@@ -713,7 +714,7 @@ func TestWhitelist(t *testing.T) {
 	t.Cleanup(d.Close)
 
 	// Matched by white filter.
-	res, err := d.CheckHost("host1", dns.TypeA, &setts)
+	res, err := d.CheckHost("host1", dns.TypeA, setts)
 	require.NoError(t, err)
 
 	assert.False(t, res.IsFiltered)
@@ -724,7 +725,7 @@ func TestWhitelist(t *testing.T) {
 	assert.Equal(t, "||host1^", res.Rules[0].Text)
 
 	// Not matched by white filter, but matched by block filter.
-	res, err = d.CheckHost("host2", dns.TypeA, &setts)
+	res, err = d.CheckHost("host2", dns.TypeA, setts)
 	require.NoError(t, err)
 
 	assert.True(t, res.IsFiltered)
@@ -750,7 +751,7 @@ func applyClientSettings(setts *Settings) {
 }
 
 func TestClientSettings(t *testing.T) {
-	d := newForTest(t,
+	d, setts := newForTest(t,
 		&Config{
 			ParentalEnabled:     true,
 			SafeBrowsingEnabled: false,
@@ -796,7 +797,7 @@ func TestClientSettings(t *testing.T) {
 		return func(t *testing.T) {
 			t.Helper()
 
-			r, err := d.CheckHost(tc.host, dns.TypeA, &setts)
+			r, err := d.CheckHost(tc.host, dns.TypeA, setts)
 			require.NoError(t, err)
 
 			if before {
@@ -814,7 +815,7 @@ func TestClientSettings(t *testing.T) {
 		t.Run(tc.name, makeTester(tc, tc.before))
 	}
 
-	applyClientSettings(&setts)
+	applyClientSettings(setts)
 
 	for _, tc := range testCases {
 		t.Run(tc.name, makeTester(tc, !tc.before))
@@ -824,13 +825,13 @@ func TestClientSettings(t *testing.T) {
 // Benchmarks.
 
 func BenchmarkSafeBrowsing(b *testing.B) {
-	d := newForTest(b, &Config{SafeBrowsingEnabled: true}, nil)
+	d, setts := newForTest(b, &Config{SafeBrowsingEnabled: true}, nil)
 	b.Cleanup(d.Close)
 
 	d.SetSafeBrowsingUpstream(aghtest.NewBlockUpstream(sbBlocked, true))
 
 	for n := 0; n < b.N; n++ {
-		res, err := d.CheckHost(sbBlocked, dns.TypeA, &setts)
+		res, err := d.CheckHost(sbBlocked, dns.TypeA, setts)
 		require.NoError(b, err)
 
 		assert.Truef(b, res.IsFiltered, "expected hostname %q to match", sbBlocked)
@@ -838,14 +839,14 @@ func BenchmarkSafeBrowsing(b *testing.B) {
 }
 
 func BenchmarkSafeBrowsingParallel(b *testing.B) {
-	d := newForTest(b, &Config{SafeBrowsingEnabled: true}, nil)
+	d, setts := newForTest(b, &Config{SafeBrowsingEnabled: true}, nil)
 	b.Cleanup(d.Close)
 
 	d.SetSafeBrowsingUpstream(aghtest.NewBlockUpstream(sbBlocked, true))
 
 	b.RunParallel(func(pb *testing.PB) {
 		for pb.Next() {
-			res, err := d.CheckHost(sbBlocked, dns.TypeA, &setts)
+			res, err := d.CheckHost(sbBlocked, dns.TypeA, setts)
 			require.NoError(b, err)
 
 			assert.Truef(b, res.IsFiltered, "expected hostname %q to match", sbBlocked)
@@ -854,7 +855,7 @@ func BenchmarkSafeBrowsingParallel(b *testing.B) {
 }
 
 func BenchmarkSafeSearch(b *testing.B) {
-	d := newForTest(b, &Config{SafeSearchEnabled: true}, nil)
+	d, _ := newForTest(b, &Config{SafeSearchEnabled: true}, nil)
 	b.Cleanup(d.Close)
 	for n := 0; n < b.N; n++ {
 		val, ok := d.SafeSearchDomain("www.google.com")
@@ -865,7 +866,7 @@ func BenchmarkSafeSearch(b *testing.B) {
 }
 
 func BenchmarkSafeSearchParallel(b *testing.B) {
-	d := newForTest(b, &Config{SafeSearchEnabled: true}, nil)
+	d, _ := newForTest(b, &Config{SafeSearchEnabled: true}, nil)
 	b.Cleanup(d.Close)
 	b.RunParallel(func(pb *testing.PB) {
 		for pb.Next() {

internal/filtering/http.go

@@ -1,15 +1,13 @@
-package home
+package filtering
 
 import (
 	"encoding/json"
 	"fmt"
-	"io"
 	"net"
 	"net/http"
 	"net/url"
 	"os"
 	"path/filepath"
-	"strings"
 	"time"
 
 	"github.com/AdguardTeam/AdGuardHome/internal/aghhttp"
@@ -34,7 +32,7 @@ func validateFilterURL(urlStr string) (err error) {
 		return fmt.Errorf("checking filter url: %w", err)
 	}
 
-	if s := url.Scheme; s != schemeHTTP && s != schemeHTTPS {
+	if s := url.Scheme; s != aghhttp.SchemeHTTP && s != aghhttp.SchemeHTTPS {
 		return fmt.Errorf("checking filter url: invalid scheme %q", s)
 	}
 
@@ -47,7 +45,7 @@ type filterAddJSON struct {
 	Whitelist bool   `json:"whitelist"`
 }
 
-func (f *Filtering) handleFilteringAddURL(w http.ResponseWriter, r *http.Request) {
+func (d *DNSFilter) handleFilteringAddURL(w http.ResponseWriter, r *http.Request) {
 	fj := filterAddJSON{}
 	err := json.NewDecoder(r.Body).Decode(&fj)
 	if err != nil {
@@ -65,14 +63,14 @@ func (f *Filtering) handleFilteringAddURL(w http.ResponseWriter, r *http.Request
 	}
 
 	// Check for duplicates
-	if filterExists(fj.URL) {
+	if d.filterExists(fj.URL) {
 		aghhttp.Error(r, w, http.StatusBadRequest, "Filter URL already added -- %s", fj.URL)
 
 		return
 	}
 
 	// Set necessary properties
-	filt := filter{
+	filt := FilterYAML{
 		Enabled: true,
 		URL:     fj.URL,
 		Name:    fj.Name,
@@ -81,7 +79,7 @@ func (f *Filtering) handleFilteringAddURL(w http.ResponseWriter, r *http.Request
 	filt.ID = assignUniqueFilterID()
 
 	// Download the filter contents
-	ok, err := f.update(&filt)
+	ok, err := d.update(&filt)
 	if err != nil {
 		aghhttp.Error(
 			r,
@@ -109,14 +107,14 @@ func (f *Filtering) handleFilteringAddURL(w http.ResponseWriter, r *http.Request
 
 	// URL is assumed valid so append it to filters, update config, write new
 	// file and reload it to engines.
-	if !filterAdd(filt) {
+	if !d.filterAdd(filt) {
 		aghhttp.Error(r, w, http.StatusBadRequest, "Filter URL already added -- %s", filt.URL)
 
 		return
 	}
 
-	onConfigModified()
-	enableFilters(true)
+	d.ConfigModified()
+	d.EnableFilters(true)
 
 	_, err = fmt.Fprintf(w, "OK %d rules\n", filt.RulesCount)
 	if err != nil {
@@ -124,7 +122,7 @@ func (f *Filtering) handleFilteringAddURL(w http.ResponseWriter, r *http.Request
 	}
 }
 
-func (f *Filtering) handleFilteringRemoveURL(w http.ResponseWriter, r *http.Request) {
+func (d *DNSFilter) handleFilteringRemoveURL(w http.ResponseWriter, r *http.Request) {
 	type request struct {
 		URL       string `json:"url"`
 		Whitelist bool   `json:"whitelist"`
@@ -138,23 +136,23 @@ func (f *Filtering) handleFilteringRemoveURL(w http.ResponseWriter, r *http.Requ
 		return
 	}
 
-	config.Lock()
-	filters := &config.Filters
+	d.filtersMu.Lock()
+	filters := &d.Filters
 	if req.Whitelist {
-		filters = &config.WhitelistFilters
+		filters = &d.WhitelistFilters
 	}
 
-	var deleted filter
-	var newFilters []filter
-	for _, f := range *filters {
-		if f.URL != req.URL {
-			newFilters = append(newFilters, f)
+	var deleted FilterYAML
+	var newFilters []FilterYAML
+	for _, flt := range *filters {
+		if flt.URL != req.URL {
+			newFilters = append(newFilters, flt)
 
 			continue
 		}
 
-		deleted = f
-		path := f.Path()
+		deleted = flt
+		path := flt.Path(d.DataDir)
 		err = os.Rename(path, path+".old")
 		if err != nil {
 			log.Error("deleting filter %q: %s", path, err)
@@ -162,10 +160,10 @@ func (f *Filtering) handleFilteringRemoveURL(w http.ResponseWriter, r *http.Requ
 	}
 
 	*filters = newFilters
-	config.Unlock()
+	d.filtersMu.Unlock()
 
-	onConfigModified()
-	enableFilters(true)
+	d.ConfigModified()
+	d.EnableFilters(true)
 
 	// NOTE: The old files "filter.txt.old" aren't deleted.  It's not really
 	// necessary, but will require the additional complicated code to run
@@ -191,55 +189,51 @@ type filterURLReq struct {
 	Whitelist bool              `json:"whitelist"`
 }
 
-func (f *Filtering) handleFilteringSetURL(w http.ResponseWriter, r *http.Request) {
+func (d *DNSFilter) handleFilteringSetURL(w http.ResponseWriter, r *http.Request) {
 	fj := filterURLReq{}
 	err := json.NewDecoder(r.Body).Decode(&fj)
 	if err != nil {
-		aghhttp.Error(r, w, http.StatusBadRequest, "json decode: %s", err)
+		aghhttp.Error(r, w, http.StatusBadRequest, "decoding request: %s", err)
 
 		return
 	}
 
 	if fj.Data == nil {
-		err = errors.Error("data cannot be null")
-		aghhttp.Error(r, w, http.StatusBadRequest, "%s", err)
+		aghhttp.Error(r, w, http.StatusBadRequest, "%s", errors.Error("data is absent"))
 
 		return
 	}
 
 	err = validateFilterURL(fj.Data.URL)
 	if err != nil {
-		err = fmt.Errorf("invalid url: %s", err)
-		aghhttp.Error(r, w, http.StatusBadRequest, "%s", err)
+		aghhttp.Error(r, w, http.StatusBadRequest, "invalid url: %s", err)
 
 		return
 	}
 
-	filt := filter{
+	filt := FilterYAML{
 		Enabled: fj.Data.Enabled,
 		Name:    fj.Data.Name,
 		URL:     fj.Data.URL,
 	}
-	status := f.filterSetProperties(fj.URL, filt, fj.Whitelist)
+	status := d.filterSetProperties(fj.URL, filt, fj.Whitelist)
 	if (status & statusFound) == 0 {
-		http.Error(w, "URL doesn't exist", http.StatusBadRequest)
+		aghhttp.Error(r, w, http.StatusBadRequest, "URL doesn't exist")
+
 		return
 	}
 	if (status & statusURLExists) != 0 {
-		http.Error(w, "URL already exists", http.StatusBadRequest)
+		aghhttp.Error(r, w, http.StatusBadRequest, "URL already exists")
+
 		return
 	}
 
-	onConfigModified()
+	d.ConfigModified()
 
 	restart := (status & statusEnabledChanged) != 0
 	if (status&statusUpdateRequired) != 0 && fj.Data.Enabled {
-		// download new filter and apply its rules
-		flags := filterRefreshBlocklists
-		if fj.Whitelist {
-			flags = filterRefreshAllowlists
-		}
-		nUpdated, _ := f.refreshFilters(flags, true)
+		// download new filter and apply its rules.
+		nUpdated := d.refreshFilters(!fj.Whitelist, fj.Whitelist, false)
 		// if at least 1 filter has been updated, refreshFilters() restarts the filtering automatically
 		// if not - we restart the filtering ourselves
 		restart = false
@@ -249,25 +243,34 @@ func (f *Filtering) handleFilteringSetURL(w http.ResponseWriter, r *http.Request
 	}
 
 	if restart {
-		enableFilters(true)
+		d.EnableFilters(true)
 	}
 }
 
-func (f *Filtering) handleFilteringSetRules(w http.ResponseWriter, r *http.Request) {
-	// This use of ReadAll is safe, because request's body is now limited.
-	body, err := io.ReadAll(r.Body)
+// filteringRulesReq is the JSON structure for settings custom filtering rules.
+type filteringRulesReq struct {
+	Rules []string `json:"rules"`
+}
+
+func (d *DNSFilter) handleFilteringSetRules(w http.ResponseWriter, r *http.Request) {
+	if aghhttp.WriteTextPlainDeprecated(w, r) {
+		return
+	}
+
+	req := &filteringRulesReq{}
+	err := json.NewDecoder(r.Body).Decode(req)
 	if err != nil {
-		aghhttp.Error(r, w, http.StatusBadRequest, "Failed to read request body: %s", err)
+		aghhttp.Error(r, w, http.StatusBadRequest, "reading req: %s", err)
 
 		return
 	}
 
-	config.UserRules = strings.Split(string(body), "\n")
-	onConfigModified()
-	enableFilters(true)
+	d.UserRules = req.Rules
+	d.ConfigModified()
+	d.EnableFilters(true)
 }
 
-func (f *Filtering) handleFilteringRefresh(w http.ResponseWriter, r *http.Request) {
+func (d *DNSFilter) handleFilteringRefresh(w http.ResponseWriter, r *http.Request) {
 	type Req struct {
 		White bool `json:"whitelist"`
 	}
@@ -285,35 +288,27 @@ func (f *Filtering) handleFilteringRefresh(w http.ResponseWriter, r *http.Reques
 		return
 	}
 
-	flags := filterRefreshBlocklists
-	if req.White {
-		flags = filterRefreshAllowlists
-	}
-	func() {
-		// Temporarily unlock the Context.controlLock because the
-		// f.refreshFilters waits for it to be unlocked but it's
-		// actually locked in ensure wrapper.
-		//
-		// TODO(e.burkov):  Reconsider this messy syncing process.
-		Context.controlLock.Unlock()
-		defer Context.controlLock.Lock()
-
-		resp.Updated, err = f.refreshFilters(flags|filterRefreshForce, false)
-	}()
-	if err != nil {
-		aghhttp.Error(r, w, http.StatusInternalServerError, "%s", err)
+	var ok bool
+	resp.Updated, _, ok = d.tryRefreshFilters(!req.White, req.White, true)
+	if !ok {
+		aghhttp.Error(
+			r,
+			w,
+			http.StatusInternalServerError,
+			"filters update procedure is already running",
+		)
 
 		return
 	}
 
-	js, err := json.Marshal(resp)
+	w.Header().Set("Content-Type", "application/json")
+
+	err = json.NewEncoder(w).Encode(resp)
 	if err != nil {
 		aghhttp.Error(r, w, http.StatusInternalServerError, "json encode: %s", err)
 
 		return
 	}
-	w.Header().Set("Content-Type", "application/json")
-	_, _ = w.Write(js)
 }
 
 type filterJSON struct {
@@ -333,7 +328,7 @@ type filteringConfig struct {
 	Enabled          bool         `json:"enabled"`
 }
 
-func filterToJSON(f filter) filterJSON {
+func filterToJSON(f FilterYAML) filterJSON {
 	fj := filterJSON{
 		ID:         f.ID,
 		Enabled:    f.Enabled,
@@ -350,21 +345,21 @@ func filterToJSON(f filter) filterJSON {
 }
 
 // Get filtering configuration
-func (f *Filtering) handleFilteringStatus(w http.ResponseWriter, r *http.Request) {
+func (d *DNSFilter) handleFilteringStatus(w http.ResponseWriter, r *http.Request) {
 	resp := filteringConfig{}
-	config.RLock()
-	resp.Enabled = config.DNS.FilteringEnabled
-	resp.Interval = config.DNS.FiltersUpdateIntervalHours
-	for _, f := range config.Filters {
+	d.filtersMu.RLock()
+	resp.Enabled = d.FilteringEnabled
+	resp.Interval = d.FiltersUpdateIntervalHours
+	for _, f := range d.Filters {
 		fj := filterToJSON(f)
 		resp.Filters = append(resp.Filters, fj)
 	}
-	for _, f := range config.WhitelistFilters {
+	for _, f := range d.WhitelistFilters {
 		fj := filterToJSON(f)
 		resp.WhitelistFilters = append(resp.WhitelistFilters, fj)
 	}
-	resp.UserRules = config.UserRules
-	config.RUnlock()
+	resp.UserRules = d.UserRules
+	d.filtersMu.RUnlock()
 
 	jsonVal, err := json.Marshal(resp)
 	if err != nil {
@@ -380,7 +375,7 @@ func (f *Filtering) handleFilteringStatus(w http.ResponseWriter, r *http.Request
 }
 
 // Set filtering configuration
-func (f *Filtering) handleFilteringConfig(w http.ResponseWriter, r *http.Request) {
+func (d *DNSFilter) handleFilteringConfig(w http.ResponseWriter, r *http.Request) {
 	req := filteringConfig{}
 	err := json.NewDecoder(r.Body).Decode(&req)
 	if err != nil {
@@ -389,22 +384,22 @@ func (f *Filtering) handleFilteringConfig(w http.ResponseWriter, r *http.Request
 		return
 	}
 
-	if !checkFiltersUpdateIntervalHours(req.Interval) {
+	if !ValidateUpdateIvl(req.Interval) {
 		aghhttp.Error(r, w, http.StatusBadRequest, "Unsupported interval")
 
 		return
 	}
 
 	func() {
-		config.Lock()
-		defer config.Unlock()
+		d.filtersMu.Lock()
+		defer d.filtersMu.Unlock()
 
-		config.DNS.FilteringEnabled = req.Enabled
-		config.DNS.FiltersUpdateIntervalHours = req.Interval
+		d.FilteringEnabled = req.Enabled
+		d.FiltersUpdateIntervalHours = req.Interval
 	}()
 
-	onConfigModified()
-	enableFilters(true)
+	d.ConfigModified()
+	d.EnableFilters(true)
 }
 
 type checkHostRespRule struct {
@@ -435,15 +430,15 @@ type checkHostResp struct {
 	FilterID int64 `json:"filter_id"`
 }
 
-func (f *Filtering) handleCheckHost(w http.ResponseWriter, r *http.Request) {
-	q := r.URL.Query()
-	host := q.Get("name")
+func (d *DNSFilter) handleCheckHost(w http.ResponseWriter, r *http.Request) {
+	host := r.URL.Query().Get("name")
 
-	setts := Context.dnsFilter.GetConfig()
+	setts := d.GetConfig()
 	setts.FilteringEnabled = true
 	setts.ProtectionEnabled = true
-	Context.dnsFilter.ApplyBlockedServices(&setts, nil, true)
-	result, err := Context.dnsFilter.CheckHost(host, dns.TypeA, &setts)
+
+	d.ApplyBlockedServices(&setts, nil)
+	result, err := d.CheckHost(host, dns.TypeA, &setts)
 	if err != nil {
 		aghhttp.Error(
 			r,
@@ -457,18 +452,20 @@ func (f *Filtering) handleCheckHost(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	resp := checkHostResp{}
-	resp.Reason = result.Reason.String()
-	resp.SvcName = result.ServiceName
-	resp.CanonName = result.CanonName
-	resp.IPList = result.IPList
+	rulesLen := len(result.Rules)
+	resp := checkHostResp{
+		Reason:    result.Reason.String(),
+		SvcName:   result.ServiceName,
+		CanonName: result.CanonName,
+		IPList:    result.IPList,
+		Rules:     make([]*checkHostRespRule, len(result.Rules)),
+	}
 
-	if len(result.Rules) > 0 {
+	if rulesLen > 0 {
 		resp.FilterID = result.Rules[0].FilterListID
 		resp.Rule = result.Rules[0].Text
 	}
 
-	resp.Rules = make([]*checkHostRespRule, len(result.Rules))
 	for i, r := range result.Rules {
 		resp.Rules[i] = &checkHostRespRule{
 			FilterListID: r.FilterListID,
@@ -476,28 +473,51 @@ func (f *Filtering) handleCheckHost(w http.ResponseWriter, r *http.Request) {
 		}
 	}
 
-	js, err := json.Marshal(resp)
-	if err != nil {
-		aghhttp.Error(r, w, http.StatusInternalServerError, "json encode: %s", err)
-
-		return
-	}
 	w.Header().Set("Content-Type", "application/json")
-	_, _ = w.Write(js)
+	err = json.NewEncoder(w).Encode(resp)
+	if err != nil {
+		aghhttp.Error(r, w, http.StatusInternalServerError, "encoding response: %s", err)
+	}
 }
 
 // RegisterFilteringHandlers - register handlers
-func (f *Filtering) RegisterFilteringHandlers() {
-	httpRegister(http.MethodGet, "/control/filtering/status", f.handleFilteringStatus)
-	httpRegister(http.MethodPost, "/control/filtering/config", f.handleFilteringConfig)
-	httpRegister(http.MethodPost, "/control/filtering/add_url", f.handleFilteringAddURL)
-	httpRegister(http.MethodPost, "/control/filtering/remove_url", f.handleFilteringRemoveURL)
-	httpRegister(http.MethodPost, "/control/filtering/set_url", f.handleFilteringSetURL)
-	httpRegister(http.MethodPost, "/control/filtering/refresh", f.handleFilteringRefresh)
-	httpRegister(http.MethodPost, "/control/filtering/set_rules", f.handleFilteringSetRules)
-	httpRegister(http.MethodGet, "/control/filtering/check_host", f.handleCheckHost)
+func (d *DNSFilter) RegisterFilteringHandlers() {
+	registerHTTP := d.HTTPRegister
+	if registerHTTP == nil {
+		return
+	}
+
+	registerHTTP(http.MethodPost, "/control/safebrowsing/enable", d.handleSafeBrowsingEnable)
+	registerHTTP(http.MethodPost, "/control/safebrowsing/disable", d.handleSafeBrowsingDisable)
+	registerHTTP(http.MethodGet, "/control/safebrowsing/status", d.handleSafeBrowsingStatus)
+
+	registerHTTP(http.MethodPost, "/control/parental/enable", d.handleParentalEnable)
+	registerHTTP(http.MethodPost, "/control/parental/disable", d.handleParentalDisable)
+	registerHTTP(http.MethodGet, "/control/parental/status", d.handleParentalStatus)
+
+	registerHTTP(http.MethodPost, "/control/safesearch/enable", d.handleSafeSearchEnable)
+	registerHTTP(http.MethodPost, "/control/safesearch/disable", d.handleSafeSearchDisable)
+	registerHTTP(http.MethodGet, "/control/safesearch/status", d.handleSafeSearchStatus)
+
+	registerHTTP(http.MethodGet, "/control/rewrite/list", d.handleRewriteList)
+	registerHTTP(http.MethodPost, "/control/rewrite/add", d.handleRewriteAdd)
+	registerHTTP(http.MethodPost, "/control/rewrite/delete", d.handleRewriteDelete)
+
+	registerHTTP(http.MethodGet, "/control/blocked_services/services", d.handleBlockedServicesAvailableServices)
+	registerHTTP(http.MethodGet, "/control/blocked_services/list", d.handleBlockedServicesList)
+	registerHTTP(http.MethodPost, "/control/blocked_services/set", d.handleBlockedServicesSet)
+
+	registerHTTP(http.MethodGet, "/control/filtering/status", d.handleFilteringStatus)
+	registerHTTP(http.MethodPost, "/control/filtering/config", d.handleFilteringConfig)
+	registerHTTP(http.MethodPost, "/control/filtering/add_url", d.handleFilteringAddURL)
+	registerHTTP(http.MethodPost, "/control/filtering/remove_url", d.handleFilteringRemoveURL)
+	registerHTTP(http.MethodPost, "/control/filtering/set_url", d.handleFilteringSetURL)
+	registerHTTP(http.MethodPost, "/control/filtering/refresh", d.handleFilteringRefresh)
+	registerHTTP(http.MethodPost, "/control/filtering/set_rules", d.handleFilteringSetRules)
+	registerHTTP(http.MethodGet, "/control/filtering/check_host", d.handleCheckHost)
 }
 
-func checkFiltersUpdateIntervalHours(i uint32) bool {
+// ValidateUpdateIvl returns false if i is not a valid filters update interval.
+func ValidateUpdateIvl(i uint32) bool {
 	return i == 0 || i == 1 || i == 12 || i == 1*24 || i == 3*24 || i == 7*24
 }

internal/filtering/rewrites.go

@@ -133,34 +133,31 @@ func matchDomainWildcard(host, wildcard string) (ok bool) {
 //  1. A and AAAA > CNAME
 //  2. wildcard > exact
 //  3. lower level wildcard > higher level wildcard
+//
+// TODO(a.garipov):  Replace with slices.Sort.
 type rewritesSorted []*LegacyRewrite
 
-// Len implements the sort.Interface interface for legacyRewritesSorted.
+// Len implements the sort.Interface interface for rewritesSorted.
 func (a rewritesSorted) Len() (l int) { return len(a) }
 
-// Swap implements the sort.Interface interface for legacyRewritesSorted.
+// Swap implements the sort.Interface interface for rewritesSorted.
 func (a rewritesSorted) Swap(i, j int) { a[i], a[j] = a[j], a[i] }
 
-// Less implements the sort.Interface interface for legacyRewritesSorted.
+// Less implements the sort.Interface interface for rewritesSorted.
 func (a rewritesSorted) Less(i, j int) (less bool) {
-	if a[i].Type == dns.TypeCNAME && a[j].Type != dns.TypeCNAME {
+	ith, jth := a[i], a[j]
+	if ith.Type == dns.TypeCNAME && jth.Type != dns.TypeCNAME {
 		return true
-	} else if a[i].Type != dns.TypeCNAME && a[j].Type == dns.TypeCNAME {
+	} else if ith.Type != dns.TypeCNAME && jth.Type == dns.TypeCNAME {
 		return false
 	}
 
-	if isWildcard(a[i].Domain) {
-		if !isWildcard(a[j].Domain) {
-			return false
-		}
-	} else {
-		if isWildcard(a[j].Domain) {
-			return true
-		}
+	if iw, jw := isWildcard(ith.Domain), isWildcard(jth.Domain); iw != jw {
+		return jw
 	}
 
-	// Both are wildcards.
-	return len(a[i].Domain) > len(a[j].Domain)
+	// Both are either wildcards or not.
+	return len(ith.Domain) > len(jth.Domain)
 }
 
 // prepareRewrites normalizes and validates all legacy DNS rewrites.
@@ -313,9 +310,3 @@ func (d *DNSFilter) handleRewriteDelete(w http.ResponseWriter, r *http.Request)
 
 	d.Config.ConfigModified()
 }
-
-func (d *DNSFilter) registerRewritesHandlers() {
-	d.Config.HTTPRegister(http.MethodGet, "/control/rewrite/list", d.handleRewriteList)
-	d.Config.HTTPRegister(http.MethodPost, "/control/rewrite/add", d.handleRewriteAdd)
-	d.Config.HTTPRegister(http.MethodPost, "/control/rewrite/delete", d.handleRewriteDelete)
-}

internal/filtering/rewrites_test.go

@@ -12,7 +12,7 @@ import (
 // TODO(e.burkov): All the tests in this file may and should me merged together.
 
 func TestRewrites(t *testing.T) {
-	d := newForTest(t, nil, nil)
+	d, _ := newForTest(t, nil, nil)
 	t.Cleanup(d.Close)
 
 	d.Rewrites = []*LegacyRewrite{{
@@ -188,7 +188,7 @@ func TestRewrites(t *testing.T) {
 }
 
 func TestRewritesLevels(t *testing.T) {
-	d := newForTest(t, nil, nil)
+	d, _ := newForTest(t, nil, nil)
 	t.Cleanup(d.Close)
 	// Exact host, wildcard L2, wildcard L3.
 	d.Rewrites = []*LegacyRewrite{{
@@ -235,7 +235,7 @@ func TestRewritesLevels(t *testing.T) {
 }
 
 func TestRewritesExceptionCNAME(t *testing.T) {
-	d := newForTest(t, nil, nil)
+	d, _ := newForTest(t, nil, nil)
 	t.Cleanup(d.Close)
 	// Wildcard and exception for a sub-domain.
 	d.Rewrites = []*LegacyRewrite{{
@@ -286,7 +286,7 @@ func TestRewritesExceptionCNAME(t *testing.T) {
 }
 
 func TestRewritesExceptionIP(t *testing.T) {
-	d := newForTest(t, nil, nil)
+	d, _ := newForTest(t, nil, nil)
 	t.Cleanup(d.Close)
 	// Exception for AAAA record.
 	d.Rewrites = []*LegacyRewrite{{

internal/filtering/safebrowsing.go

@@ -415,17 +415,3 @@ func (d *DNSFilter) handleParentalStatus(w http.ResponseWriter, r *http.Request)
 		aghhttp.Error(r, w, http.StatusInternalServerError, "Unable to write response json: %s", err)
 	}
 }
-
-func (d *DNSFilter) registerSecurityHandlers() {
-	d.Config.HTTPRegister(http.MethodPost, "/control/safebrowsing/enable", d.handleSafeBrowsingEnable)
-	d.Config.HTTPRegister(http.MethodPost, "/control/safebrowsing/disable", d.handleSafeBrowsingDisable)
-	d.Config.HTTPRegister(http.MethodGet, "/control/safebrowsing/status", d.handleSafeBrowsingStatus)
-
-	d.Config.HTTPRegister(http.MethodPost, "/control/parental/enable", d.handleParentalEnable)
-	d.Config.HTTPRegister(http.MethodPost, "/control/parental/disable", d.handleParentalDisable)
-	d.Config.HTTPRegister(http.MethodGet, "/control/parental/status", d.handleParentalStatus)
-
-	d.Config.HTTPRegister(http.MethodPost, "/control/safesearch/enable", d.handleSafeSearchEnable)
-	d.Config.HTTPRegister(http.MethodPost, "/control/safesearch/disable", d.handleSafeSearchDisable)
-	d.Config.HTTPRegister(http.MethodGet, "/control/safesearch/status", d.handleSafeSearchStatus)
-}

internal/filtering/safebrowsing_test.go

@@ -107,7 +107,7 @@ func TestSafeBrowsingCache(t *testing.T) {
 }
 
 func TestSBPC_checkErrorUpstream(t *testing.T) {
-	d := newForTest(t, &Config{SafeBrowsingEnabled: true}, nil)
+	d, _ := newForTest(t, &Config{SafeBrowsingEnabled: true}, nil)
 	t.Cleanup(d.Close)
 
 	ups := aghtest.NewErrorUpstream()
@@ -128,7 +128,7 @@ func TestSBPC_checkErrorUpstream(t *testing.T) {
 }
 
 func TestSBPC(t *testing.T) {
-	d := newForTest(t, &Config{SafeBrowsingEnabled: true}, nil)
+	d, _ := newForTest(t, &Config{SafeBrowsingEnabled: true}, nil)
 	t.Cleanup(d.Close)
 
 	const hostname = "example.org"

internal/home/auth.go

@@ -8,12 +8,14 @@ import (
 	"fmt"
 	"net"
 	"net/http"
+	"path"
 	"strconv"
 	"strings"
 	"sync"
 	"time"
 
 	"github.com/AdguardTeam/AdGuardHome/internal/aghhttp"
+	"github.com/AdguardTeam/golibs/errors"
 	"github.com/AdguardTeam/golibs/log"
 	"github.com/AdguardTeam/golibs/netutil"
 	"github.com/AdguardTeam/golibs/timeutil"
@@ -32,7 +34,8 @@ const sessionTokenSize = 16
 
 type session struct {
 	userName string
-	expire   uint32 // expiration time (in seconds)
+	// expire is the expiration time, in seconds.
+	expire uint32
 }
 
 func (s *session) serialize() []byte {
@@ -64,29 +67,29 @@ func (s *session) deserialize(data []byte) bool {
 
 // Auth - global object
 type Auth struct {
-	db         *bbolt.DB
-	blocker    *authRateLimiter
-	sessions   map[string]*session
-	users      []User
-	lock       sync.Mutex
-	sessionTTL uint32
+	db          *bbolt.DB
+	raleLimiter *authRateLimiter
+	sessions    map[string]*session
+	users       []webUser
+	lock        sync.Mutex
+	sessionTTL  uint32
 }
 
-// User object
-type User struct {
+// webUser represents a user of the Web UI.
+type webUser struct {
 	Name         string `yaml:"name"`
-	PasswordHash string `yaml:"password"` // bcrypt hash
+	PasswordHash string `yaml:"password"`
 }
 
 // InitAuth - create a global object
-func InitAuth(dbFilename string, users []User, sessionTTL uint32, blocker *authRateLimiter) *Auth {
+func InitAuth(dbFilename string, users []webUser, sessionTTL uint32, rateLimiter *authRateLimiter) *Auth {
 	log.Info("Initializing auth module: %s", dbFilename)
 
 	a := &Auth{
-		sessionTTL: sessionTTL,
-		blocker:    blocker,
-		sessions:   make(map[string]*session),
-		users:      users,
+		sessionTTL:  sessionTTL,
+		raleLimiter: rateLimiter,
+		sessions:    make(map[string]*session),
+		users:       users,
 	}
 	var err error
 	a.db, err = bbolt.Open(dbFilename, 0o644, nil)
@@ -326,35 +329,25 @@ func newSessionToken() (data []byte, err error) {
 	return randData, nil
 }
 
-// cookieTimeFormat is the format to be used in (time.Time).Format for cookie's
-// expiry field.
-const cookieTimeFormat = "Mon, 02 Jan 2006 15:04:05 GMT"
-
-// cookieExpiryFormat returns the formatted exp to be used in cookie string.
-// It's quite simple for now, but probably will be expanded in the future.
-func cookieExpiryFormat(exp time.Time) (formatted string) {
-	return exp.Format(cookieTimeFormat)
-}
-
-func (a *Auth) httpCookie(req loginJSON, addr string) (cookie string, err error) {
-	blocker := a.blocker
-	u := a.UserFind(req.Name, req.Password)
-	if len(u.Name) == 0 {
-		if blocker != nil {
-			blocker.inc(addr)
+// newCookie creates a new authentication cookie.
+func (a *Auth) newCookie(req loginJSON, addr string) (c *http.Cookie, err error) {
+	rateLimiter := a.raleLimiter
+	u, ok := a.findUser(req.Name, req.Password)
+	if !ok {
+		if rateLimiter != nil {
+			rateLimiter.inc(addr)
 		}
 
-		return "", err
+		return nil, errors.Error("invalid username or password")
 	}
 
-	if blocker != nil {
-		blocker.remove(addr)
+	if rateLimiter != nil {
+		rateLimiter.remove(addr)
 	}
 
-	var sess []byte
-	sess, err = newSessionToken()
+	sess, err := newSessionToken()
 	if err != nil {
-		return "", err
+		return nil, fmt.Errorf("generating token: %w", err)
 	}
 
 	now := time.Now().UTC()
@@ -364,11 +357,15 @@ func (a *Auth) httpCookie(req loginJSON, addr string) (cookie string, err error)
 		expire:   uint32(now.Unix()) + a.sessionTTL,
 	})
 
-	return fmt.Sprintf(
-		"%s=%s; Path=/; HttpOnly; Expires=%s",
-		sessionCookieName, hex.EncodeToString(sess),
-		cookieExpiryFormat(now.Add(cookieTTL)),
-	), nil
+	return &http.Cookie{
+		Name:    sessionCookieName,
+		Value:   hex.EncodeToString(sess),
+		Path:    "/",
+		Expires: now.Add(cookieTTL),
+
+		HttpOnly: true,
+		SameSite: http.SameSiteLaxMode,
+	}, nil
 }
 
 // realIP extracts the real IP address of the client from an HTTP request using
@@ -436,8 +433,8 @@ func handleLogin(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	if blocker := Context.auth.blocker; blocker != nil {
-		if left := blocker.check(remoteAddr); left > 0 {
+	if rateLimiter := Context.auth.raleLimiter; rateLimiter != nil {
+		if left := rateLimiter.check(remoteAddr); left > 0 {
 			w.Header().Set("Retry-After", strconv.Itoa(int(left.Seconds())))
 			aghhttp.Error(r, w, http.StatusTooManyRequests, "auth: blocked for %s", left)
 
@@ -445,10 +442,9 @@ func handleLogin(w http.ResponseWriter, r *http.Request) {
 		}
 	}
 
-	var cookie string
-	cookie, err = Context.auth.httpCookie(req, remoteAddr)
+	cookie, err := Context.auth.newCookie(req, remoteAddr)
 	if err != nil {
-		aghhttp.Error(r, w, http.StatusBadRequest, "crypto rand reader: %s", err)
+		aghhttp.Error(r, w, http.StatusForbidden, "%s", err)
 
 		return
 	}
@@ -462,20 +458,11 @@ func handleLogin(w http.ResponseWriter, r *http.Request) {
 		log.Error("auth: unknown ip")
 	}
 
-	if len(cookie) == 0 {
-		log.Info("auth: failed to login user %q from ip %v", req.Name, ip)
-
-		time.Sleep(1 * time.Second)
-
-		http.Error(w, "invalid username or password", http.StatusBadRequest)
-
-		return
-	}
-
 	log.Info("auth: user %q successfully logged in from ip %v", req.Name, ip)
 
+	http.SetCookie(w, cookie)
+
 	h := w.Header()
-	h.Set("Set-Cookie", cookie)
 	h.Set("Cache-Control", "no-store, no-cache, must-revalidate, proxy-revalidate")
 	h.Set("Pragma", "no-cache")
 	h.Set("Expires", "0")
@@ -484,17 +471,31 @@ func handleLogin(w http.ResponseWriter, r *http.Request) {
 }
 
 func handleLogout(w http.ResponseWriter, r *http.Request) {
-	cookie := r.Header.Get("Cookie")
-	sess := parseCookie(cookie)
+	respHdr := w.Header()
+	c, err := r.Cookie(sessionCookieName)
+	if err != nil {
+		// The only error that is returned from r.Cookie is [http.ErrNoCookie].
+		// The user is already logged out.
+		respHdr.Set("Location", "/login.html")
+		w.WriteHeader(http.StatusFound)
 
-	Context.auth.RemoveSession(sess)
+		return
+	}
 
-	w.Header().Set("Location", "/login.html")
+	Context.auth.RemoveSession(c.Value)
 
-	s := fmt.Sprintf("%s=; Path=/; HttpOnly; Expires=Thu, 01 Jan 1970 00:00:00 GMT",
-		sessionCookieName)
-	w.Header().Set("Set-Cookie", s)
+	c = &http.Cookie{
+		Name:    sessionCookieName,
+		Value:   "",
+		Path:    "/",
+		Expires: time.Unix(0, 0),
 
+		HttpOnly: true,
+		SameSite: http.SameSiteLaxMode,
+	}
+
+	respHdr.Set("Location", "/login.html")
+	respHdr.Set("Set-Cookie", c.String())
 	w.WriteHeader(http.StatusFound)
 }
 
@@ -504,101 +505,108 @@ func RegisterAuthHandlers() {
 	httpRegister(http.MethodGet, "/control/logout", handleLogout)
 }
 
-func parseCookie(cookie string) string {
-	pairs := strings.Split(cookie, ";")
-	for _, pair := range pairs {
-		pair = strings.TrimSpace(pair)
-		kv := strings.SplitN(pair, "=", 2)
-		if len(kv) != 2 {
-			continue
-		}
-		if kv[0] == sessionCookieName {
-			return kv[1]
-		}
-	}
-	return ""
-}
-
 // optionalAuthThird return true if user should authenticate first.
-func optionalAuthThird(w http.ResponseWriter, r *http.Request) (authFirst bool) {
-	authFirst = false
+func optionalAuthThird(w http.ResponseWriter, r *http.Request) (mustAuth bool) {
+	if glProcessCookie(r) {
+		log.Debug("auth: authentication is handled by GL-Inet submodule")
+
+		return false
+	}
 
 	// redirect to login page if not authenticated
-	ok := false
+	isAuthenticated := false
 	cookie, err := r.Cookie(sessionCookieName)
-
-	if glProcessCookie(r) {
-		log.Debug("auth: authentication was handled by GL-Inet submodule")
-		ok = true
-	} else if err == nil {
-		r := Context.auth.checkSession(cookie.Value)
-		if r == checkSessionOK {
-			ok = true
-		} else if r < 0 {
-			log.Debug("auth: invalid cookie value: %s", cookie)
-		}
-	} else {
-		// there's no Cookie, check Basic authentication
-		user, pass, ok2 := r.BasicAuth()
-		if ok2 {
-			u := Context.auth.UserFind(user, pass)
-			if len(u.Name) != 0 {
-				ok = true
-			} else {
+	if err != nil {
+		// The only error that is returned from r.Cookie is [http.ErrNoCookie].
+		// Check Basic authentication.
+		user, pass, hasBasic := r.BasicAuth()
+		if hasBasic {
+			_, isAuthenticated = Context.auth.findUser(user, pass)
+			if !isAuthenticated {
 				log.Info("auth: invalid Basic Authorization value")
 			}
 		}
-	}
-	if !ok {
-		if r.URL.Path == "/" || r.URL.Path == "/index.html" {
-			if glProcessRedirect(w, r) {
-				log.Debug("auth: redirected to login page by GL-Inet submodule")
-			} else {
-				w.Header().Set("Location", "/login.html")
-				w.WriteHeader(http.StatusFound)
-			}
-		} else {
-			w.WriteHeader(http.StatusForbidden)
-			_, _ = w.Write([]byte("Forbidden"))
+	} else {
+		res := Context.auth.checkSession(cookie.Value)
+		isAuthenticated = res == checkSessionOK
+		if !isAuthenticated {
+			log.Debug("auth: invalid cookie value: %s", cookie)
 		}
-		authFirst = true
 	}
 
-	return authFirst
+	if isAuthenticated {
+		return false
+	}
+
+	if p := r.URL.Path; p == "/" || p == "/index.html" {
+		if glProcessRedirect(w, r) {
+			log.Debug("auth: redirected to login page by GL-Inet submodule")
+		} else {
+			log.Debug("auth: redirected to login page")
+			w.Header().Set("Location", "/login.html")
+			w.WriteHeader(http.StatusFound)
+		}
+	} else {
+		log.Debug("auth: responded with forbidden to %s %s", r.Method, p)
+		w.WriteHeader(http.StatusForbidden)
+		_, _ = w.Write([]byte("Forbidden"))
+	}
+
+	return true
 }
 
-func optionalAuth(handler func(http.ResponseWriter, *http.Request)) func(http.ResponseWriter, *http.Request) {
+// TODO(a.garipov): Use [http.Handler] consistently everywhere throughout the
+// project.
+func optionalAuth(
+	h func(http.ResponseWriter, *http.Request),
+) (wrapped func(http.ResponseWriter, *http.Request)) {
 	return func(w http.ResponseWriter, r *http.Request) {
-		if r.URL.Path == "/login.html" {
-			// redirect to dashboard if already authenticated
-			authRequired := Context.auth != nil && Context.auth.AuthRequired()
+		p := r.URL.Path
+		authRequired := Context.auth != nil && Context.auth.AuthRequired()
+		if p == "/login.html" {
 			cookie, err := r.Cookie(sessionCookieName)
 			if authRequired && err == nil {
-				r := Context.auth.checkSession(cookie.Value)
-				if r == checkSessionOK {
+				// Redirect to the dashboard if already authenticated.
+				res := Context.auth.checkSession(cookie.Value)
+				if res == checkSessionOK {
 					w.Header().Set("Location", "/")
 					w.WriteHeader(http.StatusFound)
 
 					return
-				} else if r == checkSessionNotFound {
-					log.Debug("auth: invalid cookie value: %s", cookie)
 				}
-			}
 
-		} else if strings.HasPrefix(r.URL.Path, "/assets/") ||
-			strings.HasPrefix(r.URL.Path, "/login.") {
-			// process as usual
-			// no additional auth requirements
-		} else if Context.auth != nil && Context.auth.AuthRequired() {
+				log.Debug("auth: invalid cookie value: %s", cookie)
+			}
+		} else if isPublicResource(p) {
+			// Process as usual, no additional auth requirements.
+		} else if authRequired {
 			if optionalAuthThird(w, r) {
 				return
 			}
 		}
 
-		handler(w, r)
+		h(w, r)
 	}
 }
 
+// isPublicResource returns true if p is a path to a public resource.
+func isPublicResource(p string) (ok bool) {
+	isAsset, err := path.Match("/assets/*", p)
+	if err != nil {
+		// The only error that is returned from path.Match is
+		// [path.ErrBadPattern].  This is a programmer error.
+		panic(fmt.Errorf("bad asset pattern: %w", err))
+	}
+
+	isLogin, err := path.Match("/login.*", p)
+	if err != nil {
+		// Same as above.
+		panic(fmt.Errorf("bad login pattern: %w", err))
+	}
+
+	return isAsset || isLogin
+}
+
 type authHandler struct {
 	handler http.Handler
 }
@@ -612,7 +620,7 @@ func optionalAuthHandler(handler http.Handler) http.Handler {
 }
 
 // UserAdd - add new user
-func (a *Auth) UserAdd(u *User, password string) {
+func (a *Auth) UserAdd(u *webUser, password string) {
 	if len(password) == 0 {
 		return
 	}
@@ -631,31 +639,35 @@ func (a *Auth) UserAdd(u *User, password string) {
 	log.Debug("auth: added user: %s", u.Name)
 }
 
-// UserFind - find a user
-func (a *Auth) UserFind(login, password string) User {
+// findUser returns a user if there is one.
+func (a *Auth) findUser(login, password string) (u webUser, ok bool) {
 	a.lock.Lock()
 	defer a.lock.Unlock()
-	for _, u := range a.users {
+
+	for _, u = range a.users {
 		if u.Name == login &&
 			bcrypt.CompareHashAndPassword([]byte(u.PasswordHash), []byte(password)) == nil {
-			return u
+			return u, true
 		}
 	}
-	return User{}
+
+	return webUser{}, false
 }
 
 // getCurrentUser returns the current user.  It returns an empty User if the
 // user is not found.
-func (a *Auth) getCurrentUser(r *http.Request) User {
+func (a *Auth) getCurrentUser(r *http.Request) (u webUser) {
 	cookie, err := r.Cookie(sessionCookieName)
 	if err != nil {
 		// There's no Cookie, check Basic authentication.
 		user, pass, ok := r.BasicAuth()
 		if ok {
-			return Context.auth.UserFind(user, pass)
+			u, _ = Context.auth.findUser(user, pass)
+
+			return u
 		}
 
-		return User{}
+		return webUser{}
 	}
 
 	a.lock.Lock()
@@ -663,20 +675,20 @@ func (a *Auth) getCurrentUser(r *http.Request) User {
 
 	s, ok := a.sessions[cookie.Value]
 	if !ok {
-		return User{}
+		return webUser{}
 	}
 
-	for _, u := range a.users {
+	for _, u = range a.users {
 		if u.Name == s.userName {
 			return u
 		}
 	}
 
-	return User{}
+	return webUser{}
 }
 
 // GetUsers - get users
-func (a *Auth) GetUsers() []User {
+func (a *Auth) GetUsers() []webUser {
 	a.lock.Lock()
 	users := a.users
 	a.lock.Unlock()

internal/home/auth_test.go

@@ -43,14 +43,14 @@ func TestAuth(t *testing.T) {
 	dir := t.TempDir()
 	fn := filepath.Join(dir, "sessions.db")
 
-	users := []User{{
+	users := []webUser{{
 		Name:         "name",
 		PasswordHash: "$2y$05$..vyzAECIhJPfaQiOK17IukcQnqEgKJHy0iETyYqxn3YXJl8yZuo2",
 	}}
 	a := InitAuth(fn, nil, 60, nil)
 	s := session{}
 
-	user := User{Name: "name"}
+	user := webUser{Name: "name"}
 	a.UserAdd(&user, "password")
 
 	assert.Equal(t, checkSessionNotFound, a.checkSession("notfound"))
@@ -84,7 +84,8 @@ func TestAuth(t *testing.T) {
 	a.storeSession(sess, &s)
 	a.Close()
 
-	u := a.UserFind("name", "password")
+	u, ok := a.findUser("name", "password")
+	assert.True(t, ok)
 	assert.NotEmpty(t, u.Name)
 
 	time.Sleep(3 * time.Second)
@@ -118,7 +119,7 @@ func TestAuthHTTP(t *testing.T) {
 	dir := t.TempDir()
 	fn := filepath.Join(dir, "sessions.db")
 
-	users := []User{
+	users := []webUser{
 		{Name: "name", PasswordHash: "$2y$05$..vyzAECIhJPfaQiOK17IukcQnqEgKJHy0iETyYqxn3YXJl8yZuo2"},
 	}
 	Context.auth = InitAuth(fn, users, 60, nil)
@@ -150,18 +151,19 @@ func TestAuthHTTP(t *testing.T) {
 	assert.True(t, handlerCalled)
 
 	// perform login
-	cookie, err := Context.auth.httpCookie(loginJSON{Name: "name", Password: "password"}, "")
+	cookie, err := Context.auth.newCookie(loginJSON{Name: "name", Password: "password"}, "")
 	require.NoError(t, err)
-	assert.NotEmpty(t, cookie)
+	require.NotNil(t, cookie)
 
 	// get /
 	handler2 = optionalAuth(handler)
 	w.hdr = make(http.Header)
-	r.Header.Set("Cookie", cookie)
+	r.Header.Set("Cookie", cookie.String())
 	r.URL = &url.URL{Path: "/"}
 	handlerCalled = false
 	handler2(&w, &r)
 	assert.True(t, handlerCalled)
+
 	r.Header.Del("Cookie")
 
 	// get / with basic auth
@@ -177,7 +179,7 @@ func TestAuthHTTP(t *testing.T) {
 	// get login page with a valid cookie - we're redirected to /
 	handler2 = optionalAuth(handler)
 	w.hdr = make(http.Header)
-	r.Header.Set("Cookie", cookie)
+	r.Header.Set("Cookie", cookie.String())
 	r.URL = &url.URL{Path: loginURL}
 	handlerCalled = false
 	handler2(&w, &r)

internal/home/clientshttp.go

@@ -93,13 +93,7 @@ func (clients *clientsContainer) handleGetClients(w http.ResponseWriter, r *http
 
 	data.Tags = clientTags
 
-	w.Header().Set("Content-Type", "application/json")
-	e := json.NewEncoder(w).Encode(data)
-	if e != nil {
-		aghhttp.Error(r, w, http.StatusInternalServerError, "failed to encode to json: %v", e)
-
-		return
-	}
+	_ = aghhttp.WriteJSONResponse(w, r, data)
 }
 
 // Convert JSON object to Client object
@@ -249,11 +243,7 @@ func (clients *clientsContainer) handleFindClient(w http.ResponseWriter, r *http
 		})
 	}
 
-	w.Header().Set("Content-Type", "application/json")
-	err := json.NewEncoder(w).Encode(data)
-	if err != nil {
-		aghhttp.Error(r, w, http.StatusInternalServerError, "Couldn't write response: %s", err)
-	}
+	_ = aghhttp.WriteJSONResponse(w, r, data)
 }
 
 // findRuntime looks up the IP in runtime and temporary storages, like

internal/home/config.go

@@ -14,7 +14,6 @@ import (
 	"github.com/AdguardTeam/AdGuardHome/internal/filtering"
 	"github.com/AdguardTeam/AdGuardHome/internal/querylog"
 	"github.com/AdguardTeam/AdGuardHome/internal/stats"
-	"github.com/AdguardTeam/AdGuardHome/internal/version"
 	"github.com/AdguardTeam/dnsproxy/fastip"
 	"github.com/AdguardTeam/golibs/errors"
 	"github.com/AdguardTeam/golibs/log"
@@ -23,10 +22,9 @@ import (
 	yaml "gopkg.in/yaml.v3"
 )
 
-const (
-	dataDir   = "data"    // data storage
-	filterDir = "filters" // cache location for downloaded filters, it's under DataDir
-)
+// dataDir is the name of a directory under the working one to store some
+// persistent data.
+const dataDir = "data"
 
 // logSettings are the logging settings part of the configuration file.
 //
@@ -87,10 +85,10 @@ type configuration struct {
 	// It's reset after config is parsed
 	fileData []byte
 
-	BindHost     net.IP `yaml:"bind_host"`      // BindHost is the IP address of the HTTP server to bind to
-	BindPort     int    `yaml:"bind_port"`      // BindPort is the port the HTTP server
-	BetaBindPort int    `yaml:"beta_bind_port"` // BetaBindPort is the port for new client
-	Users        []User `yaml:"users"`          // Users that can access HTTP server
+	BindHost     net.IP    `yaml:"bind_host"`      // BindHost is the IP address of the HTTP server to bind to
+	BindPort     int       `yaml:"bind_port"`      // BindPort is the port the HTTP server
+	BetaBindPort int       `yaml:"beta_bind_port"` // BetaBindPort is the port for new client
+	Users        []webUser `yaml:"users"`          // Users that can access HTTP server
 	// AuthAttempts is the maximum number of failed login attempts a user
 	// can do before being blocked.
 	AuthAttempts uint `yaml:"auth_attempts"`
@@ -108,9 +106,16 @@ type configuration struct {
 	DNS dnsConfig         `yaml:"dns"`
 	TLS tlsConfigSettings `yaml:"tls"`
 
-	Filters          []filter `yaml:"filters"`
-	WhitelistFilters []filter `yaml:"whitelist_filters"`
-	UserRules        []string `yaml:"user_rules"`
+	// Filters reflects the filters from [filtering.Config].  It's cloned to the
+	// config used in the filtering module at the startup.  Afterwards it's
+	// cloned from the filtering module back here.
+	//
+	// TODO(e.burkov):  Move all the filtering configuration fields into the
+	// only configuration subsection covering the changes with a single
+	// migration.
+	Filters          []filtering.FilterYAML `yaml:"filters"`
+	WhitelistFilters []filtering.FilterYAML `yaml:"whitelist_filters"`
+	UserRules        []string               `yaml:"user_rules"`
 
 	DHCP *dhcpd.ServerConfig `yaml:"dhcp"`
 
@@ -145,9 +150,7 @@ type dnsConfig struct {
 
 	dnsforward.FilteringConfig `yaml:",inline"`
 
-	FilteringEnabled           bool             `yaml:"filtering_enabled"`       // whether or not use filter lists
-	FiltersUpdateIntervalHours uint32           `yaml:"filters_update_interval"` // time period to update filters (in hours)
-	DnsfilterConf              filtering.Config `yaml:",inline"`
+	DnsfilterConf *filtering.Config `yaml:",inline"`
 
 	// UpstreamTimeout is the timeout for querying upstream servers.
 	UpstreamTimeout timeutil.Duration `yaml:"upstream_timeout"`
@@ -193,15 +196,20 @@ type tlsConfigSettings struct {
 //
 // TODO(a.garipov, e.burkov): This global is awful and must be removed.
 var config = &configuration{
-	BindPort:     3000,
-	BetaBindPort: 0,
-	BindHost:     net.IP{0, 0, 0, 0},
-	AuthAttempts: 5,
-	AuthBlockMin: 15,
+	BindPort:           3000,
+	BetaBindPort:       0,
+	BindHost:           net.IP{0, 0, 0, 0},
+	AuthAttempts:       5,
+	AuthBlockMin:       15,
+	WebSessionTTLHours: 30 * 24,
 	DNS: dnsConfig{
-		BindHosts:     []net.IP{{0, 0, 0, 0}},
-		Port:          defaultPortDNS,
-		StatsInterval: 1,
+		BindHosts:           []net.IP{{0, 0, 0, 0}},
+		Port:                defaultPortDNS,
+		StatsInterval:       1,
+		QueryLogEnabled:     true,
+		QueryLogFileEnabled: true,
+		QueryLogInterval:    timeutil.Duration{Duration: 90 * timeutil.Day},
+		QueryLogMemSize:     1000,
 		FilteringConfig: dnsforward.FilteringConfig{
 			ProtectionEnabled:  true, // whether or not use any of filtering features
 			BlockingMode:       dnsforward.BlockingModeDefault,
@@ -222,18 +230,42 @@ var config = &configuration{
 			// was later increased to 300 due to https://github.com/AdguardTeam/AdGuardHome/issues/2257
 			MaxGoroutines: 300,
 		},
-		FilteringEnabled:           true, // whether or not use filter lists
-		FiltersUpdateIntervalHours: 24,
-		UpstreamTimeout:            timeutil.Duration{Duration: dnsforward.DefaultTimeout},
-		UsePrivateRDNS:             true,
+		DnsfilterConf: &filtering.Config{
+			SafeBrowsingCacheSize:      1 * 1024 * 1024,
+			SafeSearchCacheSize:        1 * 1024 * 1024,
+			ParentalCacheSize:          1 * 1024 * 1024,
+			CacheTime:                  30,
+			FilteringEnabled:           true,
+			FiltersUpdateIntervalHours: 24,
+		},
+		UpstreamTimeout: timeutil.Duration{Duration: dnsforward.DefaultTimeout},
+		UsePrivateRDNS:  true,
 	},
 	TLS: tlsConfigSettings{
 		PortHTTPS:       defaultPortHTTPS,
 		PortDNSOverTLS:  defaultPortTLS, // needs to be passed through to dnsproxy
 		PortDNSOverQUIC: defaultPortQUIC,
 	},
+	Filters: []filtering.FilterYAML{{
+		Filter:  filtering.Filter{ID: 1},
+		Enabled: true,
+		URL:     "https://adguardteam.github.io/AdGuardSDNSFilter/Filters/filter.txt",
+		Name:    "AdGuard DNS filter",
+	}, {
+		Filter:  filtering.Filter{ID: 2},
+		Enabled: false,
+		URL:     "https://adaway.org/hosts.txt",
+		Name:    "AdAway Default Blocklist",
+	}},
 	DHCP: &dhcpd.ServerConfig{
 		LocalDomainName: "lan",
+		Conf4: dhcpd.V4ServerConf{
+			LeaseDuration: dhcpd.DefaultDHCPLeaseTTL,
+			ICMPTimeout:   dhcpd.DefaultDHCPTimeoutICMP,
+		},
+		Conf6: dhcpd.V6ServerConf{
+			LeaseDuration: dhcpd.DefaultDHCPLeaseTTL,
+		},
 	},
 	Clients: &clientsConfig{
 		Sources: &clientSourcesConf{
@@ -255,31 +287,6 @@ var config = &configuration{
 	SchemaVersion: currentSchemaVersion,
 }
 
-// initConfig initializes default configuration for the current OS&ARCH
-func initConfig() {
-	config.WebSessionTTLHours = 30 * 24
-
-	config.DNS.QueryLogEnabled = true
-	config.DNS.QueryLogFileEnabled = true
-	config.DNS.QueryLogInterval = timeutil.Duration{Duration: 90 * timeutil.Day}
-	config.DNS.QueryLogMemSize = 1000
-
-	config.DNS.CacheSize = 4 * 1024 * 1024
-	config.DNS.DnsfilterConf.SafeBrowsingCacheSize = 1 * 1024 * 1024
-	config.DNS.DnsfilterConf.SafeSearchCacheSize = 1 * 1024 * 1024
-	config.DNS.DnsfilterConf.ParentalCacheSize = 1 * 1024 * 1024
-	config.DNS.DnsfilterConf.CacheTime = 30
-	config.Filters = defaultFilters()
-
-	config.DHCP.Conf4.LeaseDuration = dhcpd.DefaultDHCPLeaseTTL
-	config.DHCP.Conf4.ICMPTimeout = dhcpd.DefaultDHCPTimeoutICMP
-	config.DHCP.Conf6.LeaseDuration = dhcpd.DefaultDHCPLeaseTTL
-
-	if ch := version.Channel(); ch == version.ChannelEdge || ch == version.ChannelDevelopment {
-		config.BetaBindPort = 3001
-	}
-}
-
 // getConfigFilename returns path to the current config file
 func (c *configuration) getConfigFilename() string {
 	configFile, err := filepath.EvalSymlinks(Context.configFilename)
@@ -348,8 +355,8 @@ func parseConfig() (err error) {
 		return fmt.Errorf("validating udp ports: %w", err)
 	}
 
-	if !checkFiltersUpdateIntervalHours(config.DNS.FiltersUpdateIntervalHours) {
-		config.DNS.FiltersUpdateIntervalHours = 24
+	if !filtering.ValidateUpdateIvl(config.DNS.DnsfilterConf.FiltersUpdateIntervalHours) {
+		config.DNS.DnsfilterConf.FiltersUpdateIntervalHours = 24
 	}
 
 	if config.DNS.UpstreamTimeout.Duration == 0 {
@@ -418,10 +425,11 @@ func (c *configuration) write() (err error) {
 		config.DNS.AnonymizeClientIP = dc.AnonymizeClientIP
 	}
 
-	if Context.dnsFilter != nil {
-		c := filtering.Config{}
-		Context.dnsFilter.WriteDiskConfig(&c)
-		config.DNS.DnsfilterConf = c
+	if Context.filters != nil {
+		Context.filters.WriteDiskConfig(config.DNS.DnsfilterConf)
+		config.Filters = config.DNS.DnsfilterConf.Filters
+		config.WhitelistFilters = config.DNS.DnsfilterConf.WhitelistFilters
+		config.UserRules = config.DNS.DnsfilterConf.UserRules
 	}
 
 	if s := Context.dnsServer; s != nil {

internal/home/control.go

@@ -8,6 +8,7 @@ import (
 	"net/url"
 	"runtime"
 	"strings"
+	"time"
 
 	"github.com/AdguardTeam/AdGuardHome/internal/aghhttp"
 	"github.com/AdguardTeam/AdGuardHome/internal/aghnet"
@@ -97,16 +98,16 @@ func collectDNSAddresses() (addrs []string, err error) {
 
 // statusResponse is a response for /control/status endpoint.
 type statusResponse struct {
+	Version             string   `json:"version"`
+	Language            string   `json:"language"`
 	DNSAddrs            []string `json:"dns_addresses"`
 	DNSPort             int      `json:"dns_port"`
 	HTTPPort            int      `json:"http_port"`
 	IsProtectionEnabled bool     `json:"protection_enabled"`
 	// TODO(e.burkov): Inspect if front-end doesn't requires this field as
 	// openapi.yaml declares.
-	IsDHCPAvailable bool   `json:"dhcp_available"`
-	IsRunning       bool   `json:"running"`
-	Version         string `json:"version"`
-	Language        string `json:"language"`
+	IsDHCPAvailable bool `json:"dhcp_available"`
+	IsRunning       bool `json:"running"`
 }
 
 func handleStatus(w http.ResponseWriter, r *http.Request) {
@@ -125,12 +126,12 @@ func handleStatus(w http.ResponseWriter, r *http.Request) {
 		defer config.RUnlock()
 
 		resp = statusResponse{
+			Version:   version.Version(),
 			DNSAddrs:  dnsAddrs,
 			DNSPort:   config.DNS.Port,
 			HTTPPort:  config.BindPort,
-			IsRunning: isRunning(),
-			Version:   version.Version(),
 			Language:  config.Language,
+			IsRunning: isRunning(),
 		}
 	}()
 
@@ -146,13 +147,7 @@ func handleStatus(w http.ResponseWriter, r *http.Request) {
 		resp.IsDHCPAvailable = Context.dhcpServer != nil
 	}
 
-	w.Header().Set("Content-Type", "application/json")
-	err = json.NewEncoder(w).Encode(resp)
-	if err != nil {
-		aghhttp.Error(r, w, http.StatusInternalServerError, "Unable to write response json: %s", err)
-
-		return
-	}
+	_ = aghhttp.WriteJSONResponse(w, r, resp)
 }
 
 type profileJSON struct {
@@ -162,13 +157,16 @@ type profileJSON struct {
 func handleGetProfile(w http.ResponseWriter, r *http.Request) {
 	pj := profileJSON{}
 	u := Context.auth.getCurrentUser(r)
+
 	pj.Name = u.Name
 
 	data, err := json.Marshal(pj)
 	if err != nil {
 		aghhttp.Error(r, w, http.StatusInternalServerError, "json.Marshal: %s", err)
+
 		return
 	}
+
 	_, _ = w.Write(data)
 }
 
@@ -199,19 +197,29 @@ func httpRegister(method, url string, handler http.HandlerFunc) {
 	Context.mux.Handle(url, postInstallHandler(optionalAuthHandler(gziphandler.GzipHandler(ensureHandler(method, handler)))))
 }
 
-// ----------------------------------
-// helper functions for HTTP handlers
-// ----------------------------------
-func ensure(method string, handler func(http.ResponseWriter, *http.Request)) func(http.ResponseWriter, *http.Request) {
+// ensure returns a wrapped handler that makes sure that the request has the
+// correct method as well as additional method and header checks.
+func ensure(
+	method string,
+	handler func(http.ResponseWriter, *http.Request),
+) (wrapped func(http.ResponseWriter, *http.Request)) {
 	return func(w http.ResponseWriter, r *http.Request) {
-		log.Debug("%s %v", r.Method, r.URL)
+		start := time.Now()
+		m, u := r.Method, r.URL
+		log.Debug("started %s %s %s", m, r.Host, u)
+		defer func() { log.Debug("finished %s %s %s in %s", m, r.Host, u, time.Since(start)) }()
+
+		if m != method {
+			aghhttp.Error(r, w, http.StatusMethodNotAllowed, "only method %s is allowed", method)
 
-		if r.Method != method {
-			http.Error(w, "This request must be "+method, http.StatusMethodNotAllowed)
 			return
 		}
 
-		if method == http.MethodPost || method == http.MethodPut || method == http.MethodDelete {
+		if modifiesData(m) {
+			if !ensureContentType(w, r) {
+				return
+			}
+
 			Context.controlLock.Lock()
 			defer Context.controlLock.Unlock()
 		}
@@ -220,6 +228,42 @@ func ensure(method string, handler func(http.ResponseWriter, *http.Request)) fun
 	}
 }
 
+// modifiesData returns true if m is an HTTP method that can modify data.
+func modifiesData(m string) (ok bool) {
+	return m == http.MethodPost || m == http.MethodPut || m == http.MethodDelete
+}
+
+// ensureContentType makes sure that the content type of a data-modifying
+// request is set correctly.  If it is not, ensureContentType writes a response
+// to w, and ok is false.
+func ensureContentType(w http.ResponseWriter, r *http.Request) (ok bool) {
+	const statusUnsup = http.StatusUnsupportedMediaType
+
+	cType := r.Header.Get(aghhttp.HdrNameContentType)
+	if r.ContentLength == 0 {
+		if cType == "" {
+			return true
+		}
+
+		// Assume that browsers always send a content type when submitting HTML
+		// forms and require no content type for requests with no body to make
+		// sure that the request comes from JavaScript.
+		aghhttp.Error(r, w, statusUnsup, "empty body with content-type %q not allowed", cType)
+
+		return false
+
+	}
+
+	const wantCType = aghhttp.HdrValApplicationJSON
+	if cType == wantCType {
+		return true
+	}
+
+	aghhttp.Error(r, w, statusUnsup, "only content-type %s is allowed", wantCType)
+
+	return false
+}
+
 func ensurePOST(handler func(http.ResponseWriter, *http.Request)) func(http.ResponseWriter, *http.Request) {
 	return ensure(http.MethodPost, handler)
 }
@@ -291,7 +335,7 @@ func handleHTTPSRedirect(w http.ResponseWriter, r *http.Request) (ok bool) {
 		}
 
 		httpsURL := &url.URL{
-			Scheme:   schemeHTTPS,
+			Scheme:   aghhttp.SchemeHTTPS,
 			Host:     hostPort,
 			Path:     r.URL.Path,
 			RawQuery: r.URL.RawQuery,
@@ -307,7 +351,7 @@ func handleHTTPSRedirect(w http.ResponseWriter, r *http.Request) (ok bool) {
 	//
 	// See https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Access-Control-Allow-Origin.
 	originURL := &url.URL{
-		Scheme: schemeHTTP,
+		Scheme: aghhttp.SchemeHTTP,
 		Host:   r.Host,
 	}
 	w.Header().Set("Access-Control-Allow-Origin", originURL.String())

internal/home/controlinstall.go

@@ -59,19 +59,7 @@ func (web *Web) handleInstallGetAddresses(w http.ResponseWriter, r *http.Request
 		data.Interfaces[iface.Name] = iface
 	}
 
-	w.Header().Set("Content-Type", "application/json")
-	err = json.NewEncoder(w).Encode(data)
-	if err != nil {
-		aghhttp.Error(
-			r,
-			w,
-			http.StatusInternalServerError,
-			"Unable to marshal default addresses to json: %s",
-			err,
-		)
-
-		return
-	}
+	_ = aghhttp.WriteJSONResponse(w, r, data)
 }
 
 type checkConfReqEnt struct {
@@ -201,13 +189,7 @@ func (web *Web) handleInstallCheckConfig(w http.ResponseWriter, r *http.Request)
 		resp.StaticIP = handleStaticIP(req.DNS.IP, req.SetStaticIP)
 	}
 
-	w.Header().Set("Content-Type", "application/json")
-	err = json.NewEncoder(w).Encode(resp)
-	if err != nil {
-		aghhttp.Error(r, w, http.StatusInternalServerError, "encoding the response: %s", err)
-
-		return
-	}
+	_ = aghhttp.WriteJSONResponse(w, r, resp)
 }
 
 // handleStaticIP - handles static IP request
@@ -424,7 +406,7 @@ func (web *Web) handleInstallConfigure(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	u := &User{
+	u := &webUser{
 		Name: req.Username,
 	}
 	Context.auth.UserAdd(u, req.Password)
@@ -688,19 +670,7 @@ func (web *Web) handleInstallGetAddressesBeta(w http.ResponseWriter, r *http.Req
 
 	data.Interfaces = ifaces
 
-	w.Header().Set("Content-Type", "application/json")
-	err = json.NewEncoder(w).Encode(data)
-	if err != nil {
-		aghhttp.Error(
-			r,
-			w,
-			http.StatusInternalServerError,
-			"Unable to marshal default addresses to json: %s",
-			err,
-		)
-
-		return
-	}
+	_ = aghhttp.WriteJSONResponse(w, r, data)
 }
 
 // registerBetaInstallHandlers registers the install handlers for new client

internal/home/controlupdate.go

@@ -28,8 +28,6 @@ type temporaryError interface {
 
 // Get the latest available version from the Internet
 func handleGetVersionJSON(w http.ResponseWriter, r *http.Request) {
-	w.Header().Set("Content-Type", "application/json")
-
 	resp := &versionResponse{}
 	if Context.disableUpdate {
 		resp.Disabled = true
@@ -71,10 +69,7 @@ func handleGetVersionJSON(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	err = json.NewEncoder(w).Encode(resp)
-	if err != nil {
-		aghhttp.Error(r, w, http.StatusInternalServerError, "writing body: %s", err)
-	}
+	_ = aghhttp.WriteJSONResponse(w, r, resp)
 }
 
 // requestVersionInfo sets the VersionInfo field of resp if it can reach the

internal/home/dns.go

@@ -31,7 +31,10 @@ const (
 
 // Called by other modules when configuration is changed
 func onConfigModified() {
-	_ = config.write()
+	err := config.write()
+	if err != nil {
+		log.Error("writing config: %s", err)
+	}
 }
 
 // initDNSServer creates an instance of the dnsforward.Server
@@ -71,11 +74,11 @@ func initDNSServer() (err error) {
 	}
 	Context.queryLog = querylog.New(conf)
 
-	filterConf := config.DNS.DnsfilterConf
-	filterConf.EtcHosts = Context.etcHosts
-	filterConf.ConfigModified = onConfigModified
-	filterConf.HTTPRegister = httpRegister
-	Context.dnsFilter = filtering.New(&filterConf, nil)
+	Context.filters, err = filtering.New(config.DNS.DnsfilterConf, nil)
+	if err != nil {
+		// Don't wrap the error, since it's informative enough as is.
+		return err
+	}
 
 	var privateNets netutil.SubnetSet
 	switch len(config.DNS.PrivateNets) {
@@ -83,13 +86,10 @@ func initDNSServer() (err error) {
 		// Use an optimized locally-served matcher.
 		privateNets = netutil.SubnetSetFunc(netutil.IsLocallyServed)
 	case 1:
-		var n *net.IPNet
-		n, err = netutil.ParseSubnet(config.DNS.PrivateNets[0])
+		privateNets, err = netutil.ParseSubnet(config.DNS.PrivateNets[0])
 		if err != nil {
 			return fmt.Errorf("preparing the set of private subnets: %w", err)
 		}
-
-		privateNets = n
 	default:
 		var nets []*net.IPNet
 		nets, err = netutil.ParseSubnets(config.DNS.PrivateNets...)
@@ -101,15 +101,13 @@ func initDNSServer() (err error) {
 	}
 
 	p := dnsforward.DNSCreateParams{
-		DNSFilter:   Context.dnsFilter,
+		DNSFilter:   Context.filters,
 		Stats:       Context.stats,
 		QueryLog:    Context.queryLog,
 		PrivateNets: privateNets,
 		Anonymizer:  anonymizer,
 		LocalDomain: config.DHCP.LocalDomainName,
-	}
-	if Context.dhcpServer != nil {
-		p.DHCPServer = Context.dhcpServer
+		DHCPServer:  Context.dhcpServer,
 	}
 
 	Context.dnsServer, err = dnsforward.NewServer(p)
@@ -143,7 +141,6 @@ func initDNSServer() (err error) {
 		Context.whois = initWHOIS(&Context.clients)
 	}
 
-	Context.filters.Init()
 	return nil
 }
 
@@ -335,9 +332,12 @@ func getDNSEncryption() (de dnsEncryption) {
 // applyAdditionalFiltering adds additional client information and settings if
 // the client has them.
 func applyAdditionalFiltering(clientIP net.IP, clientID string, setts *filtering.Settings) {
-	Context.dnsFilter.ApplyBlockedServices(setts, nil, true)
+	// pref is a prefix for logging messages around the scope.
+	const pref = "applying filters"
 
-	log.Debug("looking up settings for client with ip %s and clientid %q", clientIP, clientID)
+	Context.filters.ApplyBlockedServices(setts, nil)
+
+	log.Debug("%s: looking for client with ip %s and clientid %q", pref, clientIP, clientID)
 
 	if clientIP == nil {
 		return
@@ -349,16 +349,16 @@ func applyAdditionalFiltering(clientIP net.IP, clientID string, setts *filtering
 	if !ok {
 		c, ok = Context.clients.Find(clientIP.String())
 		if !ok {
-			log.Debug("client with ip %s and clientid %q not found", clientIP, clientID)
+			log.Debug("%s: no clients with ip %s and clientid %q", pref, clientIP, clientID)
 
 			return
 		}
 	}
 
-	log.Debug("using settings for client %q with ip %s and clientid %q", c.Name, clientIP, clientID)
+	log.Debug("%s: using settings for client %q (%s; %q)", pref, c.Name, clientIP, clientID)
 
 	if c.UseOwnBlockedServices {
-		Context.dnsFilter.ApplyBlockedServices(setts, c.BlockedServices, false)
+		Context.filters.ApplyBlockedServices(setts, c.BlockedServices)
 	}
 
 	setts.ClientName = c.Name
@@ -381,7 +381,7 @@ func startDNSServer() error {
 		return fmt.Errorf("unable to start forwarding DNS server: Already running")
 	}
 
-	enableFiltersLocked(false)
+	Context.filters.EnableFilters(false)
 
 	Context.clients.Start()
 
@@ -390,7 +390,6 @@ func startDNSServer() error {
 		return fmt.Errorf("couldn't start forwarding DNS server: %w", err)
 	}
 
-	Context.dnsFilter.Start()
 	Context.filters.Start()
 	Context.stats.Start()
 	Context.queryLog.Start()
@@ -449,10 +448,7 @@ func closeDNSServer() {
 		Context.dnsServer = nil
 	}
 
-	if Context.dnsFilter != nil {
-		Context.dnsFilter.Close()
-		Context.dnsFilter = nil
-	}
+	Context.filters.Close()
 
 	if Context.stats != nil {
 		err := Context.stats.Close()
@@ -469,7 +465,5 @@ func closeDNSServer() {
 		Context.queryLog = nil
 	}
 
-	Context.filters.Close()
-
-	log.Debug("Closed all DNS modules")
+	log.Debug("all dns modules are closed")
 }

internal/home/home.go

@@ -20,6 +20,7 @@ import (
 	"time"
 
 	"github.com/AdguardTeam/AdGuardHome/internal/aghalg"
+	"github.com/AdguardTeam/AdGuardHome/internal/aghhttp"
 	"github.com/AdguardTeam/AdGuardHome/internal/aghnet"
 	"github.com/AdguardTeam/AdGuardHome/internal/aghos"
 	"github.com/AdguardTeam/AdGuardHome/internal/aghtls"
@@ -33,6 +34,7 @@ import (
 	"github.com/AdguardTeam/golibs/errors"
 	"github.com/AdguardTeam/golibs/log"
 	"github.com/AdguardTeam/golibs/netutil"
+	"golang.org/x/exp/slices"
 	"gopkg.in/natefinch/lumberjack.v2"
 )
 
@@ -52,10 +54,9 @@ type homeContext struct {
 	dnsServer  *dnsforward.Server   // DNS module
 	rdns       *RDNS                // rDNS module
 	whois      *WHOIS               // WHOIS module
-	dnsFilter  *filtering.DNSFilter // DNS filtering module
 	dhcpServer dhcpd.Interface      // DHCP module
 	auth       *Auth                // HTTP authentication module
-	filters    Filtering            // DNS filtering module
+	filters    *filtering.DNSFilter // DNS filtering module
 	web        *Web                 // Web (HTTP, HTTPS) module
 	tls        *TLSMod              // TLS module
 	// etcHosts is an IP-hostname pairs set taken from system configuration
@@ -140,7 +141,12 @@ func setupContext(args options) {
 		checkPermissions()
 	}
 
-	initConfig()
+	switch version.Channel() {
+	case version.ChannelEdge, version.ChannelDevelopment:
+		config.BetaBindPort = 3001
+	default:
+		// Go on.
+	}
 
 	Context.tlsRoots = LoadSystemRootCAs()
 	Context.transport = &http.Transport{
@@ -265,6 +271,15 @@ func setupHostsContainer() (err error) {
 }
 
 func setupConfig(args options) (err error) {
+	config.DNS.DnsfilterConf.EtcHosts = Context.etcHosts
+	config.DNS.DnsfilterConf.ConfigModified = onConfigModified
+	config.DNS.DnsfilterConf.HTTPRegister = httpRegister
+	config.DNS.DnsfilterConf.DataDir = Context.getDataDir()
+	config.DNS.DnsfilterConf.Filters = slices.Clone(config.Filters)
+	config.DNS.DnsfilterConf.WhitelistFilters = slices.Clone(config.WhitelistFilters)
+	config.DNS.DnsfilterConf.UserRules = slices.Clone(config.UserRules)
+	config.DNS.DnsfilterConf.HTTPClient = Context.client
+
 	config.DHCP.WorkDir = Context.workDir
 	config.DHCP.HTTPRegister = httpRegister
 	config.DHCP.ConfigModified = onConfigModified
@@ -384,8 +399,6 @@ func fatalOnError(err error) {
 
 // run configures and starts AdGuard Home.
 func run(args options, clientBuildFS fs.FS) {
-	var err error
-
 	// configure config filename
 	initConfigFilename(args)
 
@@ -396,7 +409,7 @@ func run(args options, clientBuildFS fs.FS) {
 	configureLogger(args)
 
 	// Print the first message after logger is configured.
-	log.Println(version.Full())
+	log.Info(version.Full())
 	log.Debug("current working directory is %s", Context.workDir)
 	if args.runningAsService {
 		log.Info("AdGuard Home is running as a service")
@@ -404,7 +417,7 @@ func run(args options, clientBuildFS fs.FS) {
 
 	setupContext(args)
 
-	err = configureOS(config)
+	err := configureOS(config)
 	fatalOnError(err)
 
 	// clients package uses filtering package's static data (filtering.BlockedSvcKnown()),
@@ -442,9 +455,9 @@ func run(args options, clientBuildFS fs.FS) {
 
 	sessFilename := filepath.Join(Context.getDataDir(), "sessions.db")
 	GLMode = args.glinetMode
-	var arl *authRateLimiter
+	var rateLimiter *authRateLimiter
 	if config.AuthAttempts > 0 && config.AuthBlockMin > 0 {
-		arl = newAuthRateLimiter(
+		rateLimiter = newAuthRateLimiter(
 			time.Duration(config.AuthBlockMin)*time.Minute,
 			config.AuthAttempts,
 		)
@@ -456,7 +469,7 @@ func run(args options, clientBuildFS fs.FS) {
 		sessFilename,
 		config.Users,
 		config.WebSessionTTLHours*60*60,
-		arl,
+		rateLimiter,
 	)
 	if Context.auth == nil {
 		log.Fatalf("Couldn't initialize Auth module")
@@ -763,12 +776,12 @@ func printHTTPAddresses(proto string) {
 	}
 
 	port := config.BindPort
-	if proto == schemeHTTPS {
+	if proto == aghhttp.SchemeHTTPS {
 		port = tlsConf.PortHTTPS
 	}
 
 	// TODO(e.burkov): Inspect and perhaps merge with the previous condition.
-	if proto == schemeHTTPS && tlsConf.ServerName != "" {
+	if proto == aghhttp.SchemeHTTPS && tlsConf.ServerName != "" {
 		printWebAddrs(proto, tlsConf.ServerName, tlsConf.PortHTTPS, 0)
 
 		return

internal/home/i18n.go

@@ -1,10 +1,8 @@
 package home
 
 import (
-	"fmt"
-	"io"
+	"encoding/json"
 	"net/http"
-	"strings"
 
 	"github.com/AdguardTeam/AdGuardHome/internal/aghhttp"
 	"github.com/AdguardTeam/golibs/log"
@@ -51,43 +49,35 @@ var allowedLanguages = stringutil.NewSet(
 	"zh-tw",
 )
 
-func handleI18nCurrentLanguage(w http.ResponseWriter, _ *http.Request) {
-	w.Header().Set("Content-Type", "text/plain")
-	log.Printf("config.Language is %s", config.Language)
-	_, err := fmt.Fprintf(w, "%s\n", config.Language)
-	if err != nil {
-		msg := fmt.Sprintf("Unable to write response json: %s", err)
-		log.Println(msg)
-		http.Error(w, msg, http.StatusInternalServerError)
+// languageJSON is the JSON structure for language requests and responses.
+type languageJSON struct {
+	Language string `json:"language"`
+}
 
-		return
-	}
+func handleI18nCurrentLanguage(w http.ResponseWriter, r *http.Request) {
+	log.Printf("home: language is %s", config.Language)
+
+	_ = aghhttp.WriteJSONResponse(w, r, &languageJSON{
+		Language: config.Language,
+	})
 }
 
 func handleI18nChangeLanguage(w http.ResponseWriter, r *http.Request) {
-	// This use of ReadAll is safe, because request's body is now limited.
-	body, err := io.ReadAll(r.Body)
+	if aghhttp.WriteTextPlainDeprecated(w, r) {
+		return
+	}
+
+	langReq := &languageJSON{}
+	err := json.NewDecoder(r.Body).Decode(langReq)
 	if err != nil {
-		msg := fmt.Sprintf("failed to read request body: %s", err)
-		log.Println(msg)
-		http.Error(w, msg, http.StatusBadRequest)
+		aghhttp.Error(r, w, http.StatusInternalServerError, "reading req: %s", err)
 
 		return
 	}
 
-	language := strings.TrimSpace(string(body))
-	if language == "" {
-		msg := "empty language specified"
-		log.Println(msg)
-		http.Error(w, msg, http.StatusBadRequest)
-
-		return
-	}
-
-	if !allowedLanguages.Has(language) {
-		msg := fmt.Sprintf("unknown language specified: %s", language)
-		log.Println(msg)
-		http.Error(w, msg, http.StatusBadRequest)
+	lang := langReq.Language
+	if !allowedLanguages.Has(lang) {
+		aghhttp.Error(r, w, http.StatusBadRequest, "unknown language: %q", lang)
 
 		return
 	}
@@ -96,7 +86,8 @@ func handleI18nChangeLanguage(w http.ResponseWriter, r *http.Request) {
 		config.Lock()
 		defer config.Unlock()
 
-		config.Language = language
+		config.Language = lang
+		log.Printf("home: language is set to %s", lang)
 	}()
 
 	onConfigModified()

internal/home/mobileconfig.go

@@ -8,6 +8,7 @@ import (
 	"net/url"
 	"path"
 
+	"github.com/AdguardTeam/AdGuardHome/internal/aghhttp"
 	"github.com/AdguardTeam/AdGuardHome/internal/dnsforward"
 	"github.com/AdguardTeam/golibs/errors"
 	"github.com/AdguardTeam/golibs/log"
@@ -82,7 +83,7 @@ func encodeMobileConfig(d *dnsSettings, clientID string) ([]byte, error) {
 	case dnsProtoHTTPS:
 		dspName = fmt.Sprintf("%s DoH", d.ServerName)
 		u := &url.URL{
-			Scheme: schemeHTTPS,
+			Scheme: aghhttp.SchemeHTTPS,
 			Host:   d.ServerName,
 			Path:   path.Join("/dns-query", clientID),
 		}

internal/home/service.go

@@ -11,6 +11,7 @@ import (
 	"syscall"
 	"time"
 
+	"github.com/AdguardTeam/AdGuardHome/internal/aghhttp"
 	"github.com/AdguardTeam/AdGuardHome/internal/aghos"
 	"github.com/AdguardTeam/AdGuardHome/internal/version"
 	"github.com/AdguardTeam/golibs/errors"
@@ -175,7 +176,8 @@ func handleServiceControlAction(opts options, clientBuildFS fs.FS) {
 	chooseSystem()
 
 	action := opts.serviceControlAction
-	log.Printf("service: control action: %s", action)
+	log.Info(version.Full())
+	log.Info("service: control action: %s", action)
 
 	if action == "reload" {
 		sendSigReload()
@@ -277,7 +279,7 @@ AdGuard Home is successfully installed and will automatically start on boot.
 There are a few more things that must be configured before you can use it.
 Click on the link below and follow the Installation Wizard steps to finish setup.
 AdGuard Home is now available at the following addresses:`)
-		printHTTPAddresses(schemeHTTP)
+		printHTTPAddresses(aghhttp.SchemeHTTP)
 	}
 }
 

internal/home/tls.go

@@ -680,8 +680,6 @@ func unmarshalTLS(r *http.Request) (tlsConfigSettingsExt, error) {
 }
 
 func marshalTLS(w http.ResponseWriter, r *http.Request, data tlsConfig) {
-	w.Header().Set("Content-Type", "application/json")
-
 	if data.CertificateChain != "" {
 		encoded := base64.StdEncoding.EncodeToString([]byte(data.CertificateChain))
 		data.CertificateChain = encoded
@@ -692,16 +690,7 @@ func marshalTLS(w http.ResponseWriter, r *http.Request, data tlsConfig) {
 		data.PrivateKey = ""
 	}
 
-	err := json.NewEncoder(w).Encode(data)
-	if err != nil {
-		aghhttp.Error(
-			r,
-			w,
-			http.StatusInternalServerError,
-			"Failed to marshal json with TLS status: %s",
-			err,
-		)
-	}
+	_ = aghhttp.WriteJSONResponse(w, r, data)
 }
 
 // registerWebHandlers registers HTTP handlers for TLS configuration

internal/home/upgrade.go

@@ -278,11 +278,11 @@ func upgradeSchema4to5(diskConf yobj) error {
 		log.Fatalf("Can't use password \"%s\": bcrypt.GenerateFromPassword: %s", passStr, err)
 		return nil
 	}
-	u := User{
+	u := webUser{
 		Name:         nameStr,
 		PasswordHash: string(hash),
 	}
-	users := []User{u}
+	users := []webUser{u}
 	diskConf["users"] = users
 	return nil
 }

internal/home/upgrade_test.go

@@ -4,6 +4,7 @@ import (
 	"testing"
 	"time"
 
+	"github.com/AdguardTeam/AdGuardHome/internal/filtering"
 	"github.com/AdguardTeam/golibs/testutil"
 	"github.com/AdguardTeam/golibs/timeutil"
 	"github.com/stretchr/testify/assert"
@@ -160,7 +161,7 @@ func assertEqualExcept(t *testing.T, oldConf, newConf yobj, oldKeys, newKeys []s
 }
 
 func testDiskConf(schemaVersion int) (diskConf yobj) {
-	filters := []filter{{
+	filters := []filtering.FilterYAML{{
 		URL:        "https://filters.adtidy.org/android/filters/111_optimized.txt",
 		Name:       "Latvian filter",
 		RulesCount: 100,

internal/home/web.go

@@ -9,6 +9,7 @@ import (
 	"sync"
 	"time"
 
+	"github.com/AdguardTeam/AdGuardHome/internal/aghhttp"
 	"github.com/AdguardTeam/AdGuardHome/internal/aghnet"
 	"github.com/AdguardTeam/AdGuardHome/internal/aghtls"
 	"github.com/AdguardTeam/golibs/errors"
@@ -19,12 +20,6 @@ import (
 	"golang.org/x/net/http2/h2c"
 )
 
-// HTTP scheme constants.
-const (
-	schemeHTTP  = "http"
-	schemeHTTPS = "https"
-)
-
 const (
 	// readTimeout is the maximum duration for reading the entire request,
 	// including the body.
@@ -166,7 +161,7 @@ func (web *Web) Start() {
 
 	// this loop is used as an ability to change listening host and/or port
 	for !web.httpsServer.shutdown {
-		printHTTPAddresses(schemeHTTP)
+		printHTTPAddresses(aghhttp.SchemeHTTP)
 		errs := make(chan error, 2)
 
 		// Use an h2c handler to support unencrypted HTTP/2, e.g. for proxies.
@@ -286,7 +281,7 @@ func (web *Web) tlsServerLoop() {
 			WriteTimeout:      web.conf.WriteTimeout,
 		}
 
-		printHTTPAddresses(schemeHTTPS)
+		printHTTPAddresses(aghhttp.SchemeHTTPS)
 		err := web.httpsServer.server.ListenAndServeTLS("", "")
 		if err != http.ErrServerClosed {
 			cleanupAlways()

internal/next/cmd/cmd.go

@@ -11,29 +11,32 @@ import (
 	"net/netip"
 	"time"
 
-	"github.com/AdguardTeam/AdGuardHome/internal/v1/websvc"
+	"github.com/AdguardTeam/AdGuardHome/internal/next/websvc"
 	"github.com/AdguardTeam/golibs/log"
 )
 
 // Main is the entry point of application.
 func Main(clientBuildFS fs.FS) {
-	// # Initial Configuration
+	// Initial Configuration
 
 	start := time.Now()
 	rand.Seed(start.UnixNano())
 
 	// TODO(a.garipov): Set up logging.
 
-	// # Web Service
+	// Web Service
 
 	// TODO(a.garipov): Use in the Web service.
 	_ = clientBuildFS
 
 	// TODO(a.garipov): Make configurable.
 	web := websvc.New(&websvc.Config{
-		Addresses: []netip.AddrPort{netip.MustParseAddrPort("127.0.0.1:3001")},
-		Start:     start,
-		Timeout:   60 * time.Second,
+		// TODO(a.garipov): Use an actual implementation.
+		ConfigManager: nil,
+		Addresses:     []netip.AddrPort{netip.MustParseAddrPort("127.0.0.1:3001")},
+		Start:         start,
+		Timeout:       60 * time.Second,
+		ForceHTTPS:    false,
 	})
 
 	err := web.Start()

internal/next/cmd/signal.go

@@ -4,7 +4,7 @@ import (
 	"os"
 
 	"github.com/AdguardTeam/AdGuardHome/internal/aghos"
-	"github.com/AdguardTeam/AdGuardHome/internal/v1/agh"
+	"github.com/AdguardTeam/AdGuardHome/internal/next/agh"
 	"github.com/AdguardTeam/golibs/log"
 )
 

internal/next/dnssvc/dnssvc.go

@@ -9,9 +9,10 @@ import (
 	"fmt"
 	"net"
 	"net/netip"
+	"sync/atomic"
 	"time"
 
-	"github.com/AdguardTeam/AdGuardHome/internal/v1/agh"
+	"github.com/AdguardTeam/AdGuardHome/internal/next/agh"
 	// TODO(a.garipov): Add a “dnsproxy proxy” package to shield us from changes
 	// and replacement of module dnsproxy.
 	"github.com/AdguardTeam/dnsproxy/proxy"
@@ -47,6 +48,14 @@ type Config struct {
 // Service is the AdGuard Home DNS service.  A nil *Service is a valid
 // [agh.Service] that does nothing.
 type Service struct {
+	// running is an atomic boolean value.  Keep it the first value in the
+	// struct to ensure atomic alignment.  0 means that the service is not
+	// running, 1 means that it is running.
+	//
+	// TODO(a.garipov): Use [atomic.Bool] in Go 1.19 or get rid of it
+	// completely.
+	running uint64
+
 	proxy      *proxy.Proxy
 	bootstraps []string
 	upstreams  []string
@@ -160,6 +169,17 @@ func (svc *Service) Start() (err error) {
 		return nil
 	}
 
+	defer func() {
+		// TODO(a.garipov): [proxy.Proxy.Start] doesn't actually have any way to
+		// tell when all servers are actually up, so at best this is merely an
+		// assumption.
+		if err != nil {
+			atomic.StoreUint64(&svc.running, 0)
+		} else {
+			atomic.StoreUint64(&svc.running, 1)
+		}
+	}()
+
 	return svc.proxy.Start()
 }
 
@@ -173,13 +193,27 @@ func (svc *Service) Shutdown(ctx context.Context) (err error) {
 	return svc.proxy.Stop()
 }
 
-// Config returns the current configuration of the web service.
+// Config returns the current configuration of the web service.  Config must not
+// be called simultaneously with Start.  If svc was initialized with ":0"
+// addresses, addrs will not return the actual bound ports until Start is
+// finished.
 func (svc *Service) Config() (c *Config) {
 	// TODO(a.garipov): Do we need to get the TCP addresses separately?
-	udpAddrs := svc.proxy.Addrs(proxy.ProtoUDP)
-	addrs := make([]netip.AddrPort, len(udpAddrs))
-	for i, a := range udpAddrs {
-		addrs[i] = a.(*net.UDPAddr).AddrPort()
+
+	var addrs []netip.AddrPort
+	if atomic.LoadUint64(&svc.running) == 1 {
+		udpAddrs := svc.proxy.Addrs(proxy.ProtoUDP)
+		addrs = make([]netip.AddrPort, len(udpAddrs))
+		for i, a := range udpAddrs {
+			addrs[i] = a.(*net.UDPAddr).AddrPort()
+		}
+	} else {
+		conf := svc.proxy.Config
+		udpAddrs := conf.UDPListenAddr
+		addrs = make([]netip.AddrPort, len(udpAddrs))
+		for i, a := range udpAddrs {
+			addrs[i] = a.AddrPort()
+		}
 	}
 
 	c = &Config{

internal/next/dnssvc/dnssvc_test.go

@@ -7,7 +7,7 @@ import (
 	"time"
 
 	"github.com/AdguardTeam/AdGuardHome/internal/aghtest"
-	"github.com/AdguardTeam/AdGuardHome/internal/v1/dnssvc"
+	"github.com/AdguardTeam/AdGuardHome/internal/next/dnssvc"
 	"github.com/AdguardTeam/dnsproxy/upstream"
 	"github.com/miekg/dns"
 	"github.com/stretchr/testify/assert"

internal/next/websvc/dns.go

@@ -0,0 +1,84 @@
+package websvc
+
+import (
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"net/netip"
+	"time"
+
+	"github.com/AdguardTeam/AdGuardHome/internal/next/dnssvc"
+)
+
+// DNS Settings Handlers
+
+// ReqPatchSettingsDNS describes the request to the PATCH /api/v1/settings/dns
+// HTTP API.
+type ReqPatchSettingsDNS struct {
+	// TODO(a.garipov): Add more as we go.
+
+	Addresses        []netip.AddrPort `json:"addresses"`
+	BootstrapServers []string         `json:"bootstrap_servers"`
+	UpstreamServers  []string         `json:"upstream_servers"`
+	UpstreamTimeout  JSONDuration     `json:"upstream_timeout"`
+}
+
+// HTTPAPIDNSSettings are the DNS settings as used by the HTTP API.  See the
+// DnsSettings object in the OpenAPI specification.
+type HTTPAPIDNSSettings struct {
+	// TODO(a.garipov): Add more as we go.
+
+	Addresses        []netip.AddrPort `json:"addresses"`
+	BootstrapServers []string         `json:"bootstrap_servers"`
+	UpstreamServers  []string         `json:"upstream_servers"`
+	UpstreamTimeout  JSONDuration     `json:"upstream_timeout"`
+}
+
+// handlePatchSettingsDNS is the handler for the PATCH /api/v1/settings/dns HTTP
+// API.
+func (svc *Service) handlePatchSettingsDNS(w http.ResponseWriter, r *http.Request) {
+	req := &ReqPatchSettingsDNS{
+		Addresses:        []netip.AddrPort{},
+		BootstrapServers: []string{},
+		UpstreamServers:  []string{},
+	}
+
+	// TODO(a.garipov): Validate nulls and proper JSON patch.
+
+	err := json.NewDecoder(r.Body).Decode(&req)
+	if err != nil {
+		writeJSONErrorResponse(w, r, fmt.Errorf("decoding: %w", err))
+
+		return
+	}
+
+	newConf := &dnssvc.Config{
+		Addresses:        req.Addresses,
+		BootstrapServers: req.BootstrapServers,
+		UpstreamServers:  req.UpstreamServers,
+		UpstreamTimeout:  time.Duration(req.UpstreamTimeout),
+	}
+
+	ctx := r.Context()
+	err = svc.confMgr.UpdateDNS(ctx, newConf)
+	if err != nil {
+		writeJSONErrorResponse(w, r, fmt.Errorf("updating: %w", err))
+
+		return
+	}
+
+	newSvc := svc.confMgr.DNS()
+	err = newSvc.Start()
+	if err != nil {
+		writeJSONErrorResponse(w, r, fmt.Errorf("starting new service: %w", err))
+
+		return
+	}
+
+	writeJSONOKResponse(w, r, &HTTPAPIDNSSettings{
+		Addresses:        newConf.Addresses,
+		BootstrapServers: newConf.BootstrapServers,
+		UpstreamServers:  newConf.UpstreamServers,
+		UpstreamTimeout:  JSONDuration(newConf.UpstreamTimeout),
+	})
+}

internal/next/websvc/dns_test.go

@@ -0,0 +1,68 @@
+package websvc_test
+
+import (
+	"context"
+	"encoding/json"
+	"net/http"
+	"net/netip"
+	"net/url"
+	"sync/atomic"
+	"testing"
+	"time"
+
+	"github.com/AdguardTeam/AdGuardHome/internal/aghtest"
+	"github.com/AdguardTeam/AdGuardHome/internal/next/dnssvc"
+	"github.com/AdguardTeam/AdGuardHome/internal/next/websvc"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestService_HandlePatchSettingsDNS(t *testing.T) {
+	wantDNS := &websvc.HTTPAPIDNSSettings{
+		Addresses:        []netip.AddrPort{netip.MustParseAddrPort("127.0.1.1:53")},
+		BootstrapServers: []string{"1.0.0.1"},
+		UpstreamServers:  []string{"1.1.1.1"},
+		UpstreamTimeout:  websvc.JSONDuration(2 * time.Second),
+	}
+
+	// TODO(a.garipov): Use [atomic.Bool] in Go 1.19.
+	var numStarted uint64
+	confMgr := newConfigManager()
+	confMgr.onDNS = func() (s websvc.ServiceWithConfig[*dnssvc.Config]) {
+		return &aghtest.ServiceWithConfig[*dnssvc.Config]{
+			OnStart: func() (err error) {
+				atomic.AddUint64(&numStarted, 1)
+
+				return nil
+			},
+			OnShutdown: func(_ context.Context) (err error) { panic("not implemented") },
+			OnConfig:   func() (c *dnssvc.Config) { panic("not implemented") },
+		}
+	}
+	confMgr.onUpdateDNS = func(ctx context.Context, c *dnssvc.Config) (err error) {
+		return nil
+	}
+
+	_, addr := newTestServer(t, confMgr)
+	u := &url.URL{
+		Scheme: "http",
+		Host:   addr.String(),
+		Path:   websvc.PathV1SettingsDNS,
+	}
+
+	req := jobj{
+		"addresses":         wantDNS.Addresses,
+		"bootstrap_servers": wantDNS.BootstrapServers,
+		"upstream_servers":  wantDNS.UpstreamServers,
+		"upstream_timeout":  wantDNS.UpstreamTimeout,
+	}
+
+	respBody := httpPatch(t, u, req, http.StatusOK)
+	resp := &websvc.HTTPAPIDNSSettings{}
+	err := json.Unmarshal(respBody, resp)
+	require.NoError(t, err)
+
+	assert.Equal(t, uint64(1), numStarted)
+	assert.Equal(t, wantDNS, resp)
+	assert.Equal(t, wantDNS, resp)
+}

internal/next/websvc/http.go

@@ -0,0 +1,109 @@
+package websvc
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"net/netip"
+	"time"
+
+	"github.com/AdguardTeam/golibs/log"
+)
+
+// HTTP Settings Handlers
+
+// ReqPatchSettingsHTTP describes the request to the PATCH /api/v1/settings/http
+// HTTP API.
+type ReqPatchSettingsHTTP struct {
+	// TODO(a.garipov): Add more as we go.
+	//
+	// TODO(a.garipov): Add wait time.
+
+	Addresses       []netip.AddrPort `json:"addresses"`
+	SecureAddresses []netip.AddrPort `json:"secure_addresses"`
+	Timeout         JSONDuration     `json:"timeout"`
+}
+
+// HTTPAPIHTTPSettings are the HTTP settings as used by the HTTP API.  See the
+// HttpSettings object in the OpenAPI specification.
+type HTTPAPIHTTPSettings struct {
+	// TODO(a.garipov): Add more as we go.
+
+	Addresses       []netip.AddrPort `json:"addresses"`
+	SecureAddresses []netip.AddrPort `json:"secure_addresses"`
+	Timeout         JSONDuration     `json:"timeout"`
+	ForceHTTPS      bool             `json:"force_https"`
+}
+
+// handlePatchSettingsHTTP is the handler for the PATCH /api/v1/settings/http
+// HTTP API.
+func (svc *Service) handlePatchSettingsHTTP(w http.ResponseWriter, r *http.Request) {
+	req := &ReqPatchSettingsHTTP{}
+
+	// TODO(a.garipov): Validate nulls and proper JSON patch.
+
+	err := json.NewDecoder(r.Body).Decode(&req)
+	if err != nil {
+		writeJSONErrorResponse(w, r, fmt.Errorf("decoding: %w", err))
+
+		return
+	}
+
+	newConf := &Config{
+		ConfigManager:   svc.confMgr,
+		TLS:             svc.tls,
+		Addresses:       req.Addresses,
+		SecureAddresses: req.SecureAddresses,
+		Timeout:         time.Duration(req.Timeout),
+		ForceHTTPS:      svc.forceHTTPS,
+	}
+
+	writeJSONOKResponse(w, r, &HTTPAPIHTTPSettings{
+		Addresses:       newConf.Addresses,
+		SecureAddresses: newConf.SecureAddresses,
+		Timeout:         JSONDuration(newConf.Timeout),
+		ForceHTTPS:      newConf.ForceHTTPS,
+	})
+
+	cancelUpd := func() {}
+	updCtx := context.Background()
+
+	ctx := r.Context()
+	if deadline, ok := ctx.Deadline(); ok {
+		updCtx, cancelUpd = context.WithDeadline(updCtx, deadline)
+	}
+
+	// Launch the new HTTP service in a separate goroutine to let this handler
+	// finish and thus, this server to shutdown.
+	go func() {
+		defer cancelUpd()
+
+		updErr := svc.confMgr.UpdateWeb(updCtx, newConf)
+		if updErr != nil {
+			writeJSONErrorResponse(w, r, fmt.Errorf("updating: %w", updErr))
+
+			return
+		}
+
+		// TODO(a.garipov): Consider better ways to do this.
+		const maxUpdDur = 10 * time.Second
+		updStart := time.Now()
+		var newSvc ServiceWithConfig[*Config]
+		for newSvc = svc.confMgr.Web(); newSvc == svc; {
+			if time.Since(updStart) >= maxUpdDur {
+				log.Error("websvc: failed to update svc after %s", maxUpdDur)
+
+				return
+			}
+
+			log.Debug("websvc: waiting for new websvc to be configured")
+			time.Sleep(1 * time.Second)
+		}
+
+		updErr = newSvc.Start()
+		if updErr != nil {
+			log.Error("websvc: new svc failed to start with error: %s", updErr)
+		}
+	}()
+}

internal/next/websvc/http_test.go

@@ -0,0 +1,62 @@
+package websvc_test
+
+import (
+	"context"
+	"crypto/tls"
+	"encoding/json"
+	"net/http"
+	"net/netip"
+	"net/url"
+	"testing"
+	"time"
+
+	"github.com/AdguardTeam/AdGuardHome/internal/next/websvc"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestService_HandlePatchSettingsHTTP(t *testing.T) {
+	wantWeb := &websvc.HTTPAPIHTTPSettings{
+		Addresses:       []netip.AddrPort{netip.MustParseAddrPort("127.0.1.1:80")},
+		SecureAddresses: []netip.AddrPort{netip.MustParseAddrPort("127.0.1.1:443")},
+		Timeout:         websvc.JSONDuration(10 * time.Second),
+		ForceHTTPS:      false,
+	}
+
+	confMgr := newConfigManager()
+	confMgr.onWeb = func() (s websvc.ServiceWithConfig[*websvc.Config]) {
+		return websvc.New(&websvc.Config{
+			TLS: &tls.Config{
+				Certificates: []tls.Certificate{{}},
+			},
+			Addresses:       []netip.AddrPort{netip.MustParseAddrPort("127.0.0.1:80")},
+			SecureAddresses: []netip.AddrPort{netip.MustParseAddrPort("127.0.0.1:443")},
+			Timeout:         5 * time.Second,
+			ForceHTTPS:      true,
+		})
+	}
+	confMgr.onUpdateWeb = func(ctx context.Context, c *websvc.Config) (err error) {
+		return nil
+	}
+
+	_, addr := newTestServer(t, confMgr)
+	u := &url.URL{
+		Scheme: "http",
+		Host:   addr.String(),
+		Path:   websvc.PathV1SettingsHTTP,
+	}
+
+	req := jobj{
+		"addresses":        wantWeb.Addresses,
+		"secure_addresses": wantWeb.SecureAddresses,
+		"timeout":          wantWeb.Timeout,
+		"force_https":      wantWeb.ForceHTTPS,
+	}
+
+	respBody := httpPatch(t, u, req, http.StatusOK)
+	resp := &websvc.HTTPAPIHTTPSettings{}
+	err := json.Unmarshal(respBody, resp)
+	require.NoError(t, err)
+
+	assert.Equal(t, wantWeb, resp)
+}

internal/next/websvc/json.go

@@ -0,0 +1,143 @@
+package websvc
+
+import (
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"strconv"
+	"time"
+
+	"github.com/AdguardTeam/AdGuardHome/internal/aghhttp"
+	"github.com/AdguardTeam/golibs/log"
+)
+
+// JSON Utilities
+
+// nsecPerMsec is the number of nanoseconds in a millisecond.
+const nsecPerMsec = float64(time.Millisecond / time.Nanosecond)
+
+// JSONDuration is a time.Duration that can be decoded from JSON and encoded
+// into JSON according to our API conventions.
+type JSONDuration time.Duration
+
+// type check
+var _ json.Marshaler = JSONDuration(0)
+
+// MarshalJSON implements the json.Marshaler interface for JSONDuration.  err is
+// always nil.
+func (d JSONDuration) MarshalJSON() (b []byte, err error) {
+	msec := float64(time.Duration(d)) / nsecPerMsec
+	b = strconv.AppendFloat(nil, msec, 'f', -1, 64)
+
+	return b, nil
+}
+
+// type check
+var _ json.Unmarshaler = (*JSONDuration)(nil)
+
+// UnmarshalJSON implements the json.Marshaler interface for *JSONDuration.
+func (d *JSONDuration) UnmarshalJSON(b []byte) (err error) {
+	if d == nil {
+		return fmt.Errorf("json duration is nil")
+	}
+
+	msec, err := strconv.ParseFloat(string(b), 64)
+	if err != nil {
+		return fmt.Errorf("parsing json time: %w", err)
+	}
+
+	*d = JSONDuration(int64(msec * nsecPerMsec))
+
+	return nil
+}
+
+// JSONTime is a time.Time that can be decoded from JSON and encoded into JSON
+// according to our API conventions.
+type JSONTime time.Time
+
+// type check
+var _ json.Marshaler = JSONTime{}
+
+// MarshalJSON implements the json.Marshaler interface for JSONTime.  err is
+// always nil.
+func (t JSONTime) MarshalJSON() (b []byte, err error) {
+	msec := float64(time.Time(t).UnixNano()) / nsecPerMsec
+	b = strconv.AppendFloat(nil, msec, 'f', -1, 64)
+
+	return b, nil
+}
+
+// type check
+var _ json.Unmarshaler = (*JSONTime)(nil)
+
+// UnmarshalJSON implements the json.Marshaler interface for *JSONTime.
+func (t *JSONTime) UnmarshalJSON(b []byte) (err error) {
+	if t == nil {
+		return fmt.Errorf("json time is nil")
+	}
+
+	msec, err := strconv.ParseFloat(string(b), 64)
+	if err != nil {
+		return fmt.Errorf("parsing json time: %w", err)
+	}
+
+	*t = JSONTime(time.Unix(0, int64(msec*nsecPerMsec)).UTC())
+
+	return nil
+}
+
+// writeJSONOKResponse writes headers with the code 200 OK, encodes v into w,
+// and logs any errors it encounters.  r is used to get additional information
+// from the request.
+func writeJSONOKResponse(w http.ResponseWriter, r *http.Request, v any) {
+	writeJSONResponse(w, r, v, http.StatusOK)
+}
+
+// writeJSONResponse writes headers with code, encodes v into w, and logs any
+// errors it encounters.  r is used to get additional information from the
+// request.
+func writeJSONResponse(w http.ResponseWriter, r *http.Request, v any, code int) {
+	// TODO(a.garipov): Put some of these to a middleware.
+	h := w.Header()
+	h.Set(aghhttp.HdrNameContentType, aghhttp.HdrValApplicationJSON)
+	h.Set(aghhttp.HdrNameServer, aghhttp.UserAgent())
+
+	w.WriteHeader(code)
+
+	err := json.NewEncoder(w).Encode(v)
+	if err != nil {
+		log.Error("websvc: writing resp to %s %s: %s", r.Method, r.URL.Path, err)
+	}
+}
+
+// ErrorCode is the error code as used by the HTTP API.  See the ErrorCode
+// definition in the OpenAPI specification.
+type ErrorCode string
+
+// ErrorCode constants.
+//
+// TODO(a.garipov): Expand and document codes.
+const (
+	// ErrorCodeTMP000 is the temporary error code used for all errors.
+	ErrorCodeTMP000 = ""
+)
+
+// HTTPAPIErrorResp is the error response as used by the HTTP API.  See the
+// BadRequestResp, InternalServerErrorResp, and similar objects in the OpenAPI
+// specification.
+type HTTPAPIErrorResp struct {
+	Code ErrorCode `json:"code"`
+	Msg  string    `json:"msg"`
+}
+
+// writeJSONErrorResponse encodes err as a JSON error into w, and logs any
+// errors it encounters.  r is used to get additional information from the
+// request.
+func writeJSONErrorResponse(w http.ResponseWriter, r *http.Request, err error) {
+	log.Error("websvc: %s %s: %s", r.Method, r.URL.Path, err)
+
+	writeJSONResponse(w, r, &HTTPAPIErrorResp{
+		Code: ErrorCodeTMP000,
+		Msg:  err.Error(),
+	}, http.StatusUnprocessableEntity)
+}

internal/next/websvc/json_test.go

@@ -0,0 +1,114 @@
+package websvc_test
+
+import (
+	"encoding/json"
+	"testing"
+	"time"
+
+	"github.com/AdguardTeam/AdGuardHome/internal/next/websvc"
+	"github.com/AdguardTeam/golibs/testutil"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+// testJSONTime is the JSON time for tests.
+var testJSONTime = websvc.JSONTime(time.Unix(1_234_567_890, 123_456_000).UTC())
+
+// testJSONTimeStr is the string with the JSON encoding of testJSONTime.
+const testJSONTimeStr = "1234567890123.456"
+
+func TestJSONTime_MarshalJSON(t *testing.T) {
+	testCases := []struct {
+		name       string
+		wantErrMsg string
+		in         websvc.JSONTime
+		want       []byte
+	}{{
+		name:       "unix_zero",
+		wantErrMsg: "",
+		in:         websvc.JSONTime(time.Unix(0, 0)),
+		want:       []byte("0"),
+	}, {
+		name:       "empty",
+		wantErrMsg: "",
+		in:         websvc.JSONTime{},
+		want:       []byte("-6795364578871.345"),
+	}, {
+		name:       "time",
+		wantErrMsg: "",
+		in:         testJSONTime,
+		want:       []byte(testJSONTimeStr),
+	}}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			got, err := tc.in.MarshalJSON()
+			testutil.AssertErrorMsg(t, tc.wantErrMsg, err)
+
+			assert.Equal(t, tc.want, got)
+		})
+	}
+
+	t.Run("json", func(t *testing.T) {
+		in := &struct {
+			A websvc.JSONTime
+		}{
+			A: testJSONTime,
+		}
+
+		got, err := json.Marshal(in)
+		require.NoError(t, err)
+
+		assert.Equal(t, []byte(`{"A":`+testJSONTimeStr+`}`), got)
+	})
+}
+
+func TestJSONTime_UnmarshalJSON(t *testing.T) {
+	testCases := []struct {
+		name       string
+		wantErrMsg string
+		want       websvc.JSONTime
+		data       []byte
+	}{{
+		name:       "time",
+		wantErrMsg: "",
+		want:       testJSONTime,
+		data:       []byte(testJSONTimeStr),
+	}, {
+		name: "bad",
+		wantErrMsg: `parsing json time: strconv.ParseFloat: parsing "{}": ` +
+			`invalid syntax`,
+		want: websvc.JSONTime{},
+		data: []byte(`{}`),
+	}}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			var got websvc.JSONTime
+			err := got.UnmarshalJSON(tc.data)
+			testutil.AssertErrorMsg(t, tc.wantErrMsg, err)
+
+			assert.Equal(t, tc.want, got)
+		})
+	}
+
+	t.Run("nil", func(t *testing.T) {
+		err := (*websvc.JSONTime)(nil).UnmarshalJSON([]byte("0"))
+		require.Error(t, err)
+
+		msg := err.Error()
+		assert.Equal(t, "json time is nil", msg)
+	})
+
+	t.Run("json", func(t *testing.T) {
+		want := testJSONTime
+		var got struct {
+			A websvc.JSONTime
+		}
+
+		err := json.Unmarshal([]byte(`{"A":`+testJSONTimeStr+`}`), &got)
+		require.NoError(t, err)
+
+		assert.Equal(t, want, got.A)
+	})
+}

internal/next/websvc/path.go

@@ -0,0 +1,11 @@
+package websvc
+
+// Path constants
+const (
+	PathHealthCheck = "/health-check"
+
+	PathV1SettingsAll  = "/api/v1/settings/all"
+	PathV1SettingsDNS  = "/api/v1/settings/dns"
+	PathV1SettingsHTTP = "/api/v1/settings/http"
+	PathV1SystemInfo   = "/api/v1/system/info"
+)

internal/next/websvc/settings.go

@@ -0,0 +1,42 @@
+package websvc
+
+import (
+	"net/http"
+)
+
+// All Settings Handlers
+
+// RespGetV1SettingsAll describes the response of the GET /api/v1/settings/all
+// HTTP API.
+type RespGetV1SettingsAll struct {
+	// TODO(a.garipov): Add more as we go.
+
+	DNS  *HTTPAPIDNSSettings  `json:"dns"`
+	HTTP *HTTPAPIHTTPSettings `json:"http"`
+}
+
+// handleGetSettingsAll is the handler for the GET /api/v1/settings/all HTTP
+// API.
+func (svc *Service) handleGetSettingsAll(w http.ResponseWriter, r *http.Request) {
+	dnsSvc := svc.confMgr.DNS()
+	dnsConf := dnsSvc.Config()
+
+	webSvc := svc.confMgr.Web()
+	httpConf := webSvc.Config()
+
+	// TODO(a.garipov): Add all currently supported parameters.
+	writeJSONOKResponse(w, r, &RespGetV1SettingsAll{
+		DNS: &HTTPAPIDNSSettings{
+			Addresses:        dnsConf.Addresses,
+			BootstrapServers: dnsConf.BootstrapServers,
+			UpstreamServers:  dnsConf.UpstreamServers,
+			UpstreamTimeout:  JSONDuration(dnsConf.UpstreamTimeout),
+		},
+		HTTP: &HTTPAPIHTTPSettings{
+			Addresses:       httpConf.Addresses,
+			SecureAddresses: httpConf.SecureAddresses,
+			Timeout:         JSONDuration(httpConf.Timeout),
+			ForceHTTPS:      httpConf.ForceHTTPS,
+		},
+	})
+}

internal/next/websvc/settings_test.go

@@ -0,0 +1,74 @@
+package websvc_test
+
+import (
+	"crypto/tls"
+	"encoding/json"
+	"net/http"
+	"net/netip"
+	"net/url"
+	"testing"
+	"time"
+
+	"github.com/AdguardTeam/AdGuardHome/internal/next/dnssvc"
+	"github.com/AdguardTeam/AdGuardHome/internal/next/websvc"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestService_HandleGetSettingsAll(t *testing.T) {
+	// TODO(a.garipov): Add all currently supported parameters.
+
+	wantDNS := &websvc.HTTPAPIDNSSettings{
+		Addresses:        []netip.AddrPort{netip.MustParseAddrPort("127.0.0.1:53")},
+		BootstrapServers: []string{"94.140.14.140", "94.140.14.141"},
+		UpstreamServers:  []string{"94.140.14.14", "1.1.1.1"},
+		UpstreamTimeout:  websvc.JSONDuration(1 * time.Second),
+	}
+
+	wantWeb := &websvc.HTTPAPIHTTPSettings{
+		Addresses:       []netip.AddrPort{netip.MustParseAddrPort("127.0.0.1:80")},
+		SecureAddresses: []netip.AddrPort{netip.MustParseAddrPort("127.0.0.1:443")},
+		Timeout:         websvc.JSONDuration(5 * time.Second),
+		ForceHTTPS:      true,
+	}
+
+	confMgr := newConfigManager()
+	confMgr.onDNS = func() (s websvc.ServiceWithConfig[*dnssvc.Config]) {
+		c, err := dnssvc.New(&dnssvc.Config{
+			Addresses:        wantDNS.Addresses,
+			UpstreamServers:  wantDNS.UpstreamServers,
+			BootstrapServers: wantDNS.BootstrapServers,
+			UpstreamTimeout:  time.Duration(wantDNS.UpstreamTimeout),
+		})
+		require.NoError(t, err)
+
+		return c
+	}
+
+	confMgr.onWeb = func() (s websvc.ServiceWithConfig[*websvc.Config]) {
+		return websvc.New(&websvc.Config{
+			TLS: &tls.Config{
+				Certificates: []tls.Certificate{{}},
+			},
+			Addresses:       wantWeb.Addresses,
+			SecureAddresses: wantWeb.SecureAddresses,
+			Timeout:         time.Duration(wantWeb.Timeout),
+			ForceHTTPS:      true,
+		})
+	}
+
+	_, addr := newTestServer(t, confMgr)
+	u := &url.URL{
+		Scheme: "http",
+		Host:   addr.String(),
+		Path:   websvc.PathV1SettingsAll,
+	}
+
+	body := httpGet(t, u, http.StatusOK)
+	resp := &websvc.RespGetV1SettingsAll{}
+	err := json.Unmarshal(body, resp)
+	require.NoError(t, err)
+
+	assert.Equal(t, wantDNS, resp.DNS)
+	assert.Equal(t, wantWeb, resp.HTTP)
+}

internal/next/websvc/system.go

@@ -16,20 +16,20 @@ type RespGetV1SystemInfo struct {
 	Channel    string   `json:"channel"`
 	OS         string   `json:"os"`
 	NewVersion string   `json:"new_version,omitempty"`
-	Start      jsonTime `json:"start"`
+	Start      JSONTime `json:"start"`
 	Version    string   `json:"version"`
 }
 
 // handleGetV1SystemInfo is the handler for the GET /api/v1/system/info HTTP
 // API.
 func (svc *Service) handleGetV1SystemInfo(w http.ResponseWriter, r *http.Request) {
-	writeJSONResponse(w, r, &RespGetV1SystemInfo{
+	writeJSONOKResponse(w, r, &RespGetV1SystemInfo{
 		Arch:    runtime.GOARCH,
 		Channel: version.Channel(),
 		OS:      runtime.GOOS,
 		// TODO(a.garipov): Fill this when we have an updater.
 		NewVersion: "",
-		Start:      jsonTime(svc.start),
+		Start:      JSONTime(svc.start),
 		Version:    version.Version(),
 	})
 }

internal/next/websvc/system_test.go

@@ -8,16 +8,17 @@ import (
 	"testing"
 	"time"
 
-	"github.com/AdguardTeam/AdGuardHome/internal/v1/websvc"
+	"github.com/AdguardTeam/AdGuardHome/internal/next/websvc"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 )
 
 func TestService_handleGetV1SystemInfo(t *testing.T) {
-	_, addr := newTestServer(t)
+	confMgr := newConfigManager()
+	_, addr := newTestServer(t, confMgr)
 	u := &url.URL{
 		Scheme: "http",
-		Host:   addr,
+		Host:   addr.String(),
 		Path:   websvc.PathV1SystemInfo,
 	}
 

internal/next/websvc/waitlistener.go

@@ -0,0 +1,31 @@
+package websvc
+
+import (
+	"net"
+	"sync"
+)
+
+// Wait Listener
+
+// waitListener is a wrapper around a listener that also calls wg.Done() on the
+// first call to Accept.  It is useful in situations where it is important to
+// catch the precise moment of the first call to Accept, for example when
+// starting an HTTP server.
+//
+// TODO(a.garipov): Move to aghnet?
+type waitListener struct {
+	net.Listener
+
+	firstAcceptWG   *sync.WaitGroup
+	firstAcceptOnce sync.Once
+}
+
+// type check
+var _ net.Listener = (*waitListener)(nil)
+
+// Accept implements the [net.Listener] interface for *waitListener.
+func (l *waitListener) Accept() (conn net.Conn, err error) {
+	l.firstAcceptOnce.Do(l.firstAcceptWG.Done)
+
+	return l.Listener.Accept()
+}

internal/next/websvc/waitlistener_internal_test.go

@@ -0,0 +1,46 @@
+package websvc
+
+import (
+	"net"
+	"sync"
+	"sync/atomic"
+	"testing"
+
+	"github.com/AdguardTeam/AdGuardHome/internal/aghchan"
+	"github.com/AdguardTeam/AdGuardHome/internal/aghtest"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestWaitListener_Accept(t *testing.T) {
+	// TODO(a.garipov): use atomic.Bool in Go 1.19.
+	var numAcceptCalls uint32
+	var l net.Listener = &aghtest.Listener{
+		OnAccept: func() (conn net.Conn, err error) {
+			atomic.AddUint32(&numAcceptCalls, 1)
+
+			return nil, nil
+		},
+		OnAddr:  func() (addr net.Addr) { panic("not implemented") },
+		OnClose: func() (err error) { panic("not implemented") },
+	}
+
+	wg := &sync.WaitGroup{}
+	wg.Add(1)
+
+	done := make(chan struct{})
+	go aghchan.MustReceive(done, testTimeout)
+
+	go func() {
+		var wrapper net.Listener = &waitListener{
+			Listener:      l,
+			firstAcceptWG: wg,
+		}
+
+		_, _ = wrapper.Accept()
+	}()
+
+	wg.Wait()
+	close(done)
+
+	assert.Equal(t, uint32(1), atomic.LoadUint32(&numAcceptCalls))
+}

internal/next/websvc/websvc.go

@@ -1,4 +1,7 @@
-// Package websvc contains the AdGuard Home web service.
+// Package websvc contains the AdGuard Home HTTP API service.
+//
+// NOTE: Packages other than cmd must not import this package, as it imports
+// most other packages.
 //
 // TODO(a.garipov): Add tests.
 package websvc
@@ -14,18 +17,46 @@ import (
 	"sync"
 	"time"
 
-	"github.com/AdguardTeam/AdGuardHome/internal/v1/agh"
+	"github.com/AdguardTeam/AdGuardHome/internal/next/agh"
+	"github.com/AdguardTeam/AdGuardHome/internal/next/dnssvc"
 	"github.com/AdguardTeam/golibs/errors"
 	"github.com/AdguardTeam/golibs/log"
 	httptreemux "github.com/dimfeld/httptreemux/v5"
 )
 
+// ServiceWithConfig is an extension of the [agh.Service] interface for services
+// that can return their configuration.
+//
+// TODO(a.garipov): Consider removing this generic interface if we figure out
+// how to make it testable in a better way.
+type ServiceWithConfig[ConfigType any] interface {
+	agh.Service
+
+	Config() (c ConfigType)
+}
+
+// ConfigManager is the configuration manager interface.
+type ConfigManager interface {
+	DNS() (svc ServiceWithConfig[*dnssvc.Config])
+	Web() (svc ServiceWithConfig[*Config])
+
+	UpdateDNS(ctx context.Context, c *dnssvc.Config) (err error)
+	UpdateWeb(ctx context.Context, c *Config) (err error)
+}
+
 // Config is the AdGuard Home web service configuration structure.
 type Config struct {
+	// ConfigManager is used to show information about services as well as
+	// dynamically reconfigure them.
+	ConfigManager ConfigManager
+
 	// TLS is the optional TLS configuration.  If TLS is not nil,
 	// SecureAddresses must not be empty.
 	TLS *tls.Config
 
+	// Start is the time of start of AdGuard Home.
+	Start time.Time
+
 	// Addresses are the addresses on which to serve the plain HTTP API.
 	Addresses []netip.AddrPort
 
@@ -33,40 +64,48 @@ type Config struct {
 	// SecureAddresses is not empty, TLS must not be nil.
 	SecureAddresses []netip.AddrPort
 
-	// Start is the time of start of AdGuard Home.
-	Start time.Time
-
 	// Timeout is the timeout for all server operations.
 	Timeout time.Duration
+
+	// ForceHTTPS tells if all requests to Addresses should be redirected to a
+	// secure address instead.
+	//
+	// TODO(a.garipov): Use; define rules, which address to redirect to.
+	ForceHTTPS bool
 }
 
 // Service is the AdGuard Home web service.  A nil *Service is a valid
 // [agh.Service] that does nothing.
 type Service struct {
-	tls     *tls.Config
-	servers []*http.Server
-	start   time.Time
-	timeout time.Duration
+	confMgr    ConfigManager
+	tls        *tls.Config
+	start      time.Time
+	servers    []*http.Server
+	timeout    time.Duration
+	forceHTTPS bool
 }
 
 // New returns a new properly initialized *Service.  If c is nil, svc is a nil
-// *Service that does nothing.
+// *Service that does nothing.  The fields of c must not be modified after
+// calling New.
 func New(c *Config) (svc *Service) {
 	if c == nil {
 		return nil
 	}
 
 	svc = &Service{
-		tls:     c.TLS,
-		start:   c.Start,
-		timeout: c.Timeout,
+		confMgr:    c.ConfigManager,
+		tls:        c.TLS,
+		start:      c.Start,
+		timeout:    c.Timeout,
+		forceHTTPS: c.ForceHTTPS,
 	}
 
 	mux := newMux(svc)
 
 	for _, a := range c.Addresses {
 		addr := a.String()
-		errLog := log.StdLog("websvc: http: "+addr, log.ERROR)
+		errLog := log.StdLog("websvc: plain http: "+addr, log.ERROR)
 		svc.servers = append(svc.servers, &http.Server{
 			Addr:              addr,
 			Handler:           mux,
@@ -111,6 +150,21 @@ func newMux(svc *Service) (mux *httptreemux.ContextMux) {
 		method:  http.MethodGet,
 		path:    PathHealthCheck,
 		isJSON:  false,
+	}, {
+		handler: svc.handleGetSettingsAll,
+		method:  http.MethodGet,
+		path:    PathV1SettingsAll,
+		isJSON:  true,
+	}, {
+		handler: svc.handlePatchSettingsDNS,
+		method:  http.MethodPatch,
+		path:    PathV1SettingsDNS,
+		isJSON:  true,
+	}, {
+		handler: svc.handlePatchSettingsHTTP,
+		method:  http.MethodPatch,
+		path:    PathV1SettingsHTTP,
+		isJSON:  true,
 	}, {
 		handler: svc.handleGetV1SystemInfo,
 		method:  http.MethodGet,
@@ -119,29 +173,41 @@ func newMux(svc *Service) (mux *httptreemux.ContextMux) {
 	}}
 
 	for _, r := range routes {
-		var h http.HandlerFunc
 		if r.isJSON {
-			// TODO(a.garipov): Consider using httptreemux's MiddlewareFunc.
-			h = jsonMw(r.handler)
+			mux.Handle(r.method, r.path, jsonMw(r.handler))
 		} else {
-			h = r.handler
+			mux.Handle(r.method, r.path, r.handler)
 		}
-
-		mux.Handle(r.method, r.path, h)
 	}
 
 	return mux
 }
 
-// Addrs returns all addresses on which this server serves the HTTP API.  Addrs
-// must not be called until Start returns.
-func (svc *Service) Addrs() (addrs []string) {
-	addrs = make([]string, 0, len(svc.servers))
+// addrs returns all addresses on which this server serves the HTTP API.  addrs
+// must not be called simultaneously with Start.  If svc was initialized with
+// ":0" addresses, addrs will not return the actual bound ports until Start is
+// finished.
+func (svc *Service) addrs() (addrs, secureAddrs []netip.AddrPort) {
 	for _, srv := range svc.servers {
-		addrs = append(addrs, srv.Addr)
+		addrPort, err := netip.ParseAddrPort(srv.Addr)
+		if err != nil {
+			// Technically shouldn't happen, since all servers must have a valid
+			// address.
+			panic(fmt.Errorf("websvc: server %q: bad address: %w", srv.Addr, err))
+		}
+
+		// srv.Serve will set TLSConfig to an almost empty value, so, instead of
+		// relying only on the nilness of TLSConfig, check the length of the
+		// certificates field as well.
+		if srv.TLSConfig == nil || len(srv.TLSConfig.Certificates) == 0 {
+			addrs = append(addrs, addrPort)
+		} else {
+			secureAddrs = append(secureAddrs, addrPort)
+		}
+
 	}
 
-	return addrs
+	return addrs, secureAddrs
 }
 
 // handleGetHealthCheck is the handler for the GET /health-check HTTP API.
@@ -149,9 +215,6 @@ func (svc *Service) handleGetHealthCheck(w http.ResponseWriter, _ *http.Request)
 	_, _ = io.WriteString(w, "OK")
 }
 
-// unit is a convenient alias for struct{}.
-type unit = struct{}
-
 // type check
 var _ agh.Service = (*Service)(nil)
 
@@ -163,11 +226,9 @@ func (svc *Service) Start() (err error) {
 		return nil
 	}
 
-	srvs := svc.servers
-
 	wg := &sync.WaitGroup{}
-	wg.Add(len(srvs))
-	for _, srv := range srvs {
+	wg.Add(len(svc.servers))
+	for _, srv := range svc.servers {
 		go serve(srv, wg)
 	}
 
@@ -181,11 +242,14 @@ func serve(srv *http.Server, wg *sync.WaitGroup) {
 	addr := srv.Addr
 	defer log.OnPanic(addr)
 
+	var proto string
 	var l net.Listener
 	var err error
 	if srv.TLSConfig == nil {
+		proto = "http"
 		l, err = net.Listen("tcp", addr)
 	} else {
+		proto = "https"
 		l, err = tls.Listen("tcp", addr, srv.TLSConfig)
 	}
 	if err != nil {
@@ -196,8 +260,12 @@ func serve(srv *http.Server, wg *sync.WaitGroup) {
 	// would mean that a random available port was automatically chosen.
 	srv.Addr = l.Addr().String()
 
-	log.Info("websvc: starting srv http://%s", srv.Addr)
-	wg.Done()
+	log.Info("websvc: starting srv %s://%s", proto, srv.Addr)
+
+	l = &waitListener{
+		Listener:      l,
+		firstAcceptWG: wg,
+	}
 
 	err = srv.Serve(l)
 	if err != nil && !errors.Is(err, http.ErrServerClosed) {
@@ -221,8 +289,28 @@ func (svc *Service) Shutdown(ctx context.Context) (err error) {
 	}
 
 	if len(errs) > 0 {
-		return errors.List("shutting down")
+		return errors.List("shutting down", errs...)
 	}
 
 	return nil
 }
+
+// Config returns the current configuration of the web service.  Config must not
+// be called simultaneously with Start.  If svc was initialized with ":0"
+// addresses, addrs will not return the actual bound ports until Start is
+// finished.
+func (svc *Service) Config() (c *Config) {
+	c = &Config{
+		ConfigManager: svc.confMgr,
+		TLS:           svc.tls,
+		// Leave Addresses and SecureAddresses empty and get the actual
+		// addresses that include the :0 ones later.
+		Start:      svc.start,
+		Timeout:    svc.timeout,
+		ForceHTTPS: svc.forceHTTPS,
+	}
+
+	c.Addresses, c.SecureAddresses = svc.addrs()
+
+	return c
+}