From d3ada9881ac0333deeaa13a77a78d6c4d891d14b Mon Sep 17 00:00:00 2001
From: Stanislav Chzhen <s.chzhen@adguard.com>
Date: Wed, 14 Jun 2023 15:08:57 +0300
Subject: [PATCH] Pull request 1854: 951-blocked-services-schedule

Merge in DNS/adguard-home from 951-blocked-services-schedule to master

Squashed commit of the following:

commit 0f0770292f8aa9dc0dddc05edefacf6655f329b8
Merge: 2705fbcfb 7309a5335
Author: Stanislav Chzhen <s.chzhen@adguard.com>
Date:   Wed Jun 14 15:00:56 2023 +0300

    Merge branch 'master' into 951-blocked-services-schedule

commit 2705fbcfba57392bcc0fa9b6e1f1dfdce9796963
Author: Stanislav Chzhen <s.chzhen@adguard.com>
Date:   Wed Jun 14 14:56:01 2023 +0300

    schedule: imp field alignment

commit ff8fa040558e97192a5a2c91c1d5722c67d88b3d
Merge: f99936f36 9fda7bfd3
Author: Stanislav Chzhen <s.chzhen@adguard.com>
Date:   Tue Jun 13 11:49:15 2023 +0300

    Merge branch 'master' into 951-blocked-services-schedule

commit f99936f36be3453b50d772ce10bfdc1ad14879c5
Author: Stanislav Chzhen <s.chzhen@adguard.com>
Date:   Fri Jun 9 19:14:06 2023 +0300

    schedule: add tests

commit 8436c2c5675d5cc22a3554ded2ce4a49eeeefc91
Author: Stanislav Chzhen <s.chzhen@adguard.com>
Date:   Thu Jun 8 20:10:03 2023 +0300

    schedule: imp code

commit 850a3d93e659e0584bd449cf5af3f13b36be9e62
Author: Stanislav Chzhen <s.chzhen@adguard.com>
Date:   Thu Jun 8 18:57:23 2023 +0300

    schedule: imp tests

commit d54c42b782a4a806d2f35abbea1826ba6394a64c
Merge: 21dfa51ea 156c199bb
Author: Stanislav Chzhen <s.chzhen@adguard.com>
Date:   Thu Jun 8 18:12:03 2023 +0300

    Merge branch 'master' into 951-blocked-services-schedule

commit 21dfa51ea7441c655ac39f2cbceeaa598d364bff
Author: Stanislav Chzhen <s.chzhen@adguard.com>
Date:   Thu Jun 8 18:02:47 2023 +0300

    all: add todo

commit d0d4532c8911fb6365f6af66ceb72a70b158b77d
Author: Stanislav Chzhen <s.chzhen@adguard.com>
Date:   Wed Jun 7 18:54:44 2023 +0300

    all: upd chlog

commit dc1d55fa23c0ec8e7f7b7cd25d3d0cbf3e51e236
Author: Stanislav Chzhen <s.chzhen@adguard.com>
Date:   Wed Jun 7 17:34:28 2023 +0300

    all: add tests

commit 601775307c2b23fa9d6cf2aa271793e8fd5f1797
Author: Stanislav Chzhen <s.chzhen@adguard.com>
Date:   Wed Jun 7 13:20:00 2023 +0300

    all: add schedule pkg

commit e0bcad0193a559a89f5f5052f5a985fa730d23be
Author: Stanislav Chzhen <s.chzhen@adguard.com>
Date:   Fri Jun 2 13:03:04 2023 +0300

    filtering: add test case

commit da7a7c20c84151ff83414cb5d576a91740a1be7e
Author: Stanislav Chzhen <s.chzhen@adguard.com>
Date:   Wed May 31 15:31:48 2023 +0300

    filtering: imp code

commit 9845a11cdae25eafe39a50f8cdc408fefe1fd746
Author: Stanislav Chzhen <s.chzhen@adguard.com>
Date:   Mon May 29 17:46:24 2023 +0300

    filtering: add type check

commit f4bcea8ad90d584ceff236ccce4f246e391e0e33
Author: Stanislav Chzhen <s.chzhen@adguard.com>
Date:   Mon May 29 17:37:25 2023 +0300

    all: imp code

commit 9de3a0f37eb65d0db2431c27dd4d69136c1485a7
Author: Stanislav Chzhen <s.chzhen@adguard.com>
Date:   Mon May 29 15:20:33 2023 +0300

    filtering: imp err msg

commit 1befab59cf2a12a3bc8296066ce1115dff5a8843
Author: Stanislav Chzhen <s.chzhen@adguard.com>
Date:   Mon May 29 14:31:14 2023 +0300

    filtering: imp tests

commit 09506f924f363f1563009cec0c44ad40d08b8ddd
Author: Stanislav Chzhen <s.chzhen@adguard.com>
Date:   Fri May 26 18:44:12 2023 +0300

    filtering: add tests

commit 36c42f523fcfe7fa6dca5f6f13e6c79f491c1ad5
Author: Stanislav Chzhen <s.chzhen@adguard.com>
Date:   Fri May 26 17:57:01 2023 +0300

    all: fix typos

commit 69399cd3ea17691ff0848baf43ff09b18b82114c
Author: Stanislav Chzhen <s.chzhen@adguard.com>
Date:   Thu May 25 18:50:51 2023 +0300

    all: upd chlog

... and 2 more commits
---
 CHANGELOG.md                                |  58 +++
 internal/dnsforward/filter.go               |   6 +-
 internal/filtering/blocked.go               |  32 +-
 internal/filtering/filtering.go             |  27 +-
 internal/filtering/http.go                  |   6 +-
 internal/home/config.go                     |   6 +
 internal/home/dns.go                        |   4 +-
 internal/home/upgrade.go                    |  53 ++-
 internal/home/upgrade_test.go               |  43 +++
 internal/schedule/schedule.go               | 220 ++++++++++++
 internal/schedule/schedule_internal_test.go | 371 ++++++++++++++++++++
 11 files changed, 798 insertions(+), 28 deletions(-)
 create mode 100644 internal/schedule/schedule.go
 create mode 100644 internal/schedule/schedule_internal_test.go

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 88ca9e69..d23c574c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -25,9 +25,67 @@ NOTE: Add new changes BELOW THIS COMMENT.
 
 ### Added
 
+- The ability to set inactivity periods for filtering blocked services in the
+  configuration file ([#951]).  The UI changes are coming in the upcoming
+  releases.
 - The ability to edit rewrite rules via `PUT /control/rewrite/update` HTTP API
   ([#1577]).
 
+### Changed
+
+#### Configuration Changes
+
+In this release, the schema version has changed from 20 to 21.
+
+- Property `dns.blocked_services`, which in schema versions 20 and earlier used
+  to be a list containing ids of blocked services, is now an object containing
+  ids and schedule for blocked services:
+
+  ```yaml
+  # BEFORE:
+  'blocked_services':
+  - id_1
+  - id_2
+
+  # AFTER:
+  'blocked_services':
+    'ids':
+    - id_1
+    - id_2
+    'schedule':
+      'time_zone': 'Local'
+      'sun':
+        'start': '0s'
+        'end': '24h'
+      'mon':
+        'start': '10m'
+        'end': '23h30m'
+      'tue':
+        'start': '20m'
+        'end': '23h'
+      'wed':
+        'start': '30m'
+        'end': '22h30m'
+      'thu':
+        'start': '40m'
+        'end': '22h'
+      'fri':
+        'start': '50m'
+        'end': '21h30m'
+      'sat':
+        'start': '1h'
+        'end': '21h'
+  ```
+
+  To rollback this change, replace `dns.blocked_services` object with the list
+  of ids of blocked services and change the `schema_version` back to `20`.
+
+### Fixed
+
+ - DNSCrypt upstream not resetting the client and resolver information on
+   dialing errors ([#5872]).
+
+[#951]:  https://github.com/AdguardTeam/AdGuardHome/issues/951
 [#1577]: https://github.com/AdguardTeam/AdGuardHome/issues/1577
 
 <!--
diff --git a/internal/dnsforward/filter.go b/internal/dnsforward/filter.go
index 6ee4e0f3..f55e3059 100644
--- a/internal/dnsforward/filter.go
+++ b/internal/dnsforward/filter.go
@@ -53,14 +53,14 @@ func (s *Server) beforeRequestHandler(
 // getClientRequestFilteringSettings looks up client filtering settings using
 // the client's IP address and ID, if any, from dctx.
 func (s *Server) getClientRequestFilteringSettings(dctx *dnsContext) *filtering.Settings {
-	setts := s.dnsFilter.GetConfig()
+	setts := s.dnsFilter.Settings()
 	setts.ProtectionEnabled = dctx.protectionEnabled
 	if s.conf.FilterHandler != nil {
 		ip, _ := netutil.IPAndPortFromAddr(dctx.proxyCtx.Addr)
-		s.conf.FilterHandler(ip, dctx.clientID, &setts)
+		s.conf.FilterHandler(ip, dctx.clientID, setts)
 	}
 
-	return &setts
+	return setts
 }
 
 // filterDNSRequest applies the dnsFilter and sets dctx.proxyCtx.Res if the
diff --git a/internal/filtering/blocked.go b/internal/filtering/blocked.go
index 4e4878aa..d8c8b9d2 100644
--- a/internal/filtering/blocked.go
+++ b/internal/filtering/blocked.go
@@ -3,8 +3,10 @@ package filtering
 import (
 	"encoding/json"
 	"net/http"
+	"time"
 
 	"github.com/AdguardTeam/AdGuardHome/internal/aghhttp"
+	"github.com/AdguardTeam/AdGuardHome/internal/schedule"
 	"github.com/AdguardTeam/golibs/log"
 	"github.com/AdguardTeam/urlfilter/rules"
 	"golang.org/x/exp/slices"
@@ -44,6 +46,15 @@ func initBlockedServices() {
 	log.Debug("filtering: initialized %d services", l)
 }
 
+// BlockedServices is the configuration of blocked services.
+type BlockedServices struct {
+	// Schedule is blocked services schedule for every day of the week.
+	Schedule *schedule.Weekly `yaml:"schedule"`
+
+	// IDs is the names of blocked services.
+	IDs []string `yaml:"ids"`
+}
+
 // BlockedSvcKnown returns true if a blocked service ID is known.
 func BlockedSvcKnown(s string) (ok bool) {
 	_, ok = serviceRules[s]
@@ -52,15 +63,22 @@ func BlockedSvcKnown(s string) (ok bool) {
 }
 
 // ApplyBlockedServices - set blocked services settings for this DNS request
-func (d *DNSFilter) ApplyBlockedServices(setts *Settings, list []string) {
+func (d *DNSFilter) ApplyBlockedServices(setts *Settings) {
+	d.confLock.RLock()
+	defer d.confLock.RUnlock()
+
 	setts.ServicesRules = []ServiceEntry{}
-	if list == nil {
-		d.confLock.RLock()
-		defer d.confLock.RUnlock()
 
-		list = d.Config.BlockedServices
+	bsvc := d.BlockedServices
+
+	// TODO(s.chzhen):  Use startTime from [dnsforward.dnsContext].
+	if !bsvc.Schedule.Contains(time.Now()) {
+		d.ApplyBlockedServicesList(setts, bsvc.IDs)
 	}
+}
 
+// ApplyBlockedServicesList appends filtering rules to the settings.
+func (d *DNSFilter) ApplyBlockedServicesList(setts *Settings, list []string) {
 	for _, name := range list {
 		rules, ok := serviceRules[name]
 		if !ok {
@@ -90,7 +108,7 @@ func (d *DNSFilter) handleBlockedServicesAll(w http.ResponseWriter, r *http.Requ
 
 func (d *DNSFilter) handleBlockedServicesList(w http.ResponseWriter, r *http.Request) {
 	d.confLock.RLock()
-	list := d.Config.BlockedServices
+	list := d.Config.BlockedServices.IDs
 	d.confLock.RUnlock()
 
 	_ = aghhttp.WriteJSONResponse(w, r, list)
@@ -106,7 +124,7 @@ func (d *DNSFilter) handleBlockedServicesSet(w http.ResponseWriter, r *http.Requ
 	}
 
 	d.confLock.Lock()
-	d.Config.BlockedServices = list
+	d.Config.BlockedServices.IDs = list
 	d.confLock.Unlock()
 
 	log.Debug("Updated blocked services list: %d", len(list))
diff --git a/internal/filtering/filtering.go b/internal/filtering/filtering.go
index 5c30c645..ea6d4bfb 100644
--- a/internal/filtering/filtering.go
+++ b/internal/filtering/filtering.go
@@ -103,9 +103,9 @@ type Config struct {
 
 	Rewrites []*LegacyRewrite `yaml:"rewrites"`
 
-	// Names of services to block (globally).
+	// BlockedServices is the configuration of blocked services.
 	// Per-client settings can override this configuration.
-	BlockedServices []string `yaml:"blocked_services"`
+	BlockedServices *BlockedServices `yaml:"blocked_services"`
 
 	// EtcHosts is a container of IP-hostname pairs taken from the operating
 	// system configuration files (e.g. /etc/hosts).
@@ -298,12 +298,12 @@ func (d *DNSFilter) SetEnabled(enabled bool) {
 	atomic.StoreUint32(&d.enabled, mathutil.BoolToNumber[uint32](enabled))
 }
 
-// GetConfig - get configuration
-func (d *DNSFilter) GetConfig() (s Settings) {
+// Settings returns filtering settings.
+func (d *DNSFilter) Settings() (s *Settings) {
 	d.confLock.RLock()
 	defer d.confLock.RUnlock()
 
-	return Settings{
+	return &Settings{
 		FilteringEnabled:    atomic.LoadUint32(&d.Config.enabled) != 0,
 		SafeSearchEnabled:   d.Config.SafeSearchConf.Enabled,
 		SafeBrowsingEnabled: d.Config.SafeBrowsingEnabled,
@@ -987,16 +987,19 @@ func New(c *Config, blockFilters []Filter) (d *DNSFilter, err error) {
 		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)
+	if d.BlockedServices != nil {
+		bsvcs := []string{}
+		for _, s := range d.BlockedServices.IDs {
+			if !BlockedSvcKnown(s) {
+				log.Debug("skipping unknown blocked-service %q", s)
 
-			continue
+				continue
+			}
+
+			bsvcs = append(bsvcs, s)
 		}
-		bsvcs = append(bsvcs, s)
+		d.BlockedServices.IDs = bsvcs
 	}
-	d.BlockedServices = bsvcs
 
 	if blockFilters != nil {
 		err = d.initFiltering(nil, blockFilters)
diff --git a/internal/filtering/http.go b/internal/filtering/http.go
index dbfe6889..41964965 100644
--- a/internal/filtering/http.go
+++ b/internal/filtering/http.go
@@ -416,12 +416,12 @@ type checkHostResp struct {
 func (d *DNSFilter) handleCheckHost(w http.ResponseWriter, r *http.Request) {
 	host := r.URL.Query().Get("name")
 
-	setts := d.GetConfig()
+	setts := d.Settings()
 	setts.FilteringEnabled = true
 	setts.ProtectionEnabled = true
 
-	d.ApplyBlockedServices(&setts, nil)
-	result, err := d.CheckHost(host, dns.TypeA, &setts)
+	d.ApplyBlockedServices(setts)
+	result, err := d.CheckHost(host, dns.TypeA, setts)
 	if err != nil {
 		aghhttp.Error(
 			r,
diff --git a/internal/home/config.go b/internal/home/config.go
index 8d9fa422..2eb0aff5 100644
--- a/internal/home/config.go
+++ b/internal/home/config.go
@@ -14,6 +14,7 @@ import (
 	"github.com/AdguardTeam/AdGuardHome/internal/dnsforward"
 	"github.com/AdguardTeam/AdGuardHome/internal/filtering"
 	"github.com/AdguardTeam/AdGuardHome/internal/querylog"
+	"github.com/AdguardTeam/AdGuardHome/internal/schedule"
 	"github.com/AdguardTeam/AdGuardHome/internal/stats"
 	"github.com/AdguardTeam/dnsproxy/fastip"
 	"github.com/AdguardTeam/golibs/errors"
@@ -316,6 +317,11 @@ var config = &configuration{
 				Yandex:     true,
 				YouTube:    true,
 			},
+
+			BlockedServices: &filtering.BlockedServices{
+				Schedule: schedule.EmptyWeekly(),
+				IDs:      []string{},
+			},
 		},
 		UpstreamTimeout: timeutil.Duration{Duration: dnsforward.DefaultTimeout},
 		UsePrivateRDNS:  true,
diff --git a/internal/home/dns.go b/internal/home/dns.go
index 9c3b03cc..48b332f2 100644
--- a/internal/home/dns.go
+++ b/internal/home/dns.go
@@ -390,7 +390,7 @@ func applyAdditionalFiltering(clientIP net.IP, clientID string, setts *filtering
 	// pref is a prefix for logging messages around the scope.
 	const pref = "applying filters"
 
-	Context.filters.ApplyBlockedServices(setts, nil)
+	Context.filters.ApplyBlockedServices(setts)
 
 	log.Debug("%s: looking for client with ip %s and clientid %q", pref, clientIP, clientID)
 
@@ -418,7 +418,7 @@ func applyAdditionalFiltering(clientIP net.IP, clientID string, setts *filtering
 		if svcs == nil {
 			svcs = []string{}
 		}
-		Context.filters.ApplyBlockedServices(setts, svcs)
+		Context.filters.ApplyBlockedServicesList(setts, svcs)
 		log.Debug("%s: services for client %q set: %s", pref, c.Name, svcs)
 	}
 
diff --git a/internal/home/upgrade.go b/internal/home/upgrade.go
index e429eb41..2326bdb7 100644
--- a/internal/home/upgrade.go
+++ b/internal/home/upgrade.go
@@ -22,7 +22,7 @@ import (
 )
 
 // currentSchemaVersion is the current schema version.
-const currentSchemaVersion = 20
+const currentSchemaVersion = 21
 
 // These aliases are provided for convenience.
 type (
@@ -94,6 +94,7 @@ func upgradeConfigSchema(oldVersion int, diskConf yobj) (err error) {
 		upgradeSchema17to18,
 		upgradeSchema18to19,
 		upgradeSchema19to20,
+		upgradeSchema20to21,
 	}
 
 	n := 0
@@ -1128,6 +1129,56 @@ func upgradeSchema19to20(diskConf yobj) (err error) {
 	return nil
 }
 
+// upgradeSchema20to21 performs the following changes:
+//
+//	# BEFORE:
+//	'dns':
+//	  'blocked_services':
+//	  - 'svc_name'
+//
+//	# AFTER:
+//	'dns':
+//	  'blocked_services':
+//	    'ids':
+//	    - 'svc_name'
+//	    'schedule':
+//	      'time_zone': 'Local'
+func upgradeSchema20to21(diskConf yobj) (err error) {
+	log.Printf("Upgrade yaml: 20 to 21")
+	diskConf["schema_version"] = 21
+
+	const field = "blocked_services"
+
+	dnsVal, ok := diskConf["dns"]
+	if !ok {
+		return nil
+	}
+
+	dns, ok := dnsVal.(yobj)
+	if !ok {
+		return fmt.Errorf("unexpected type of dns: %T", dnsVal)
+	}
+
+	blockedVal, ok := dns[field]
+	if !ok {
+		return nil
+	}
+
+	services, ok := blockedVal.(yarr)
+	if !ok {
+		return fmt.Errorf("unexpected type of blocked: %T", blockedVal)
+	}
+
+	dns[field] = yobj{
+		"ids": services,
+		"schedule": yobj{
+			"time_zone": "Local",
+		},
+	}
+
+	return nil
+}
+
 // TODO(a.garipov): Replace with log.Output when we port it to our logging
 // package.
 func funcName() string {
diff --git a/internal/home/upgrade_test.go b/internal/home/upgrade_test.go
index 11820be0..aabf514f 100644
--- a/internal/home/upgrade_test.go
+++ b/internal/home/upgrade_test.go
@@ -1140,3 +1140,46 @@ func TestUpgradeSchema19to20(t *testing.T) {
 		assert.Equal(t, 24*time.Hour, ivlVal.Duration)
 	})
 }
+
+func TestUpgradeSchema20to21(t *testing.T) {
+	const newSchemaVer = 21
+
+	testCases := []struct {
+		in   yobj
+		want yobj
+		name string
+	}{{
+		name: "nothing",
+		in:   yobj{},
+		want: yobj{
+			"schema_version": newSchemaVer,
+		},
+	}, {
+		name: "no_clients",
+		in: yobj{
+			"dns": yobj{
+				"blocked_services": yarr{"ok"},
+			},
+		},
+		want: yobj{
+			"dns": yobj{
+				"blocked_services": yobj{
+					"ids": yarr{"ok"},
+					"schedule": yobj{
+						"time_zone": "Local",
+					},
+				},
+			},
+			"schema_version": newSchemaVer,
+		},
+	}}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			err := upgradeSchema20to21(tc.in)
+			require.NoError(t, err)
+
+			assert.Equal(t, tc.want, tc.in)
+		})
+	}
+}
diff --git a/internal/schedule/schedule.go b/internal/schedule/schedule.go
new file mode 100644
index 00000000..ba3757f9
--- /dev/null
+++ b/internal/schedule/schedule.go
@@ -0,0 +1,220 @@
+// Package schedule provides types for scheduling.
+package schedule
+
+import (
+	"fmt"
+	"time"
+
+	"github.com/AdguardTeam/golibs/errors"
+	"github.com/AdguardTeam/golibs/timeutil"
+	"gopkg.in/yaml.v3"
+)
+
+// Weekly is a schedule for one week.  Each day of the week has one range with
+// a beginning and an end.
+type Weekly struct {
+	// location is used to calculate the offsets of the day ranges.
+	location *time.Location
+
+	// days are the day ranges of this schedule.  The indexes of this array are
+	// the [time.Weekday] values.
+	days [7]dayRange
+}
+
+// EmptyWeekly creates empty weekly schedule with local time zone.
+func EmptyWeekly() (w *Weekly) {
+	return &Weekly{
+		location: time.Local,
+	}
+}
+
+// Contains returns true if t is within the corresponding day range of the
+// schedule in the schedule's time zone.
+func (w *Weekly) Contains(t time.Time) (ok bool) {
+	t = t.In(w.location)
+	wd := t.Weekday()
+	dr := w.days[wd]
+
+	// Calculate the offset of the day range.
+	//
+	// NOTE: Do not use [time.Truncate] since it requires UTC time zone.
+	y, m, d := t.Date()
+	day := time.Date(y, m, d, 0, 0, 0, 0, w.location)
+	offset := t.Sub(day)
+
+	return dr.contains(offset)
+}
+
+// type check
+var _ yaml.Unmarshaler = (*Weekly)(nil)
+
+// UnmarshalYAML implements the [yaml.Unmarshaler] interface for *Weekly.
+func (w *Weekly) UnmarshalYAML(value *yaml.Node) (err error) {
+	conf := &weeklyConfig{}
+
+	err = value.Decode(conf)
+	if err != nil {
+		// Don't wrap the error since it's informative enough as is.
+		return err
+	}
+
+	weekly := Weekly{}
+
+	weekly.location, err = time.LoadLocation(conf.TimeZone)
+	if err != nil {
+		// Don't wrap the error since it's informative enough as is.
+		return err
+	}
+
+	days := []dayConfig{
+		time.Sunday:    conf.Sunday,
+		time.Monday:    conf.Monday,
+		time.Tuesday:   conf.Tuesday,
+		time.Wednesday: conf.Wednesday,
+		time.Thursday:  conf.Thursday,
+		time.Friday:    conf.Friday,
+		time.Saturday:  conf.Saturday,
+	}
+	for i, d := range days {
+		r := dayRange{
+			start: d.Start.Duration,
+			end:   d.End.Duration,
+		}
+
+		err = w.validate(r)
+		if err != nil {
+			return fmt.Errorf("weekday %s: %w", time.Weekday(i), err)
+		}
+
+		weekly.days[i] = r
+	}
+
+	*w = weekly
+
+	return nil
+}
+
+// weeklyConfig is the YAML configuration structure of Weekly.
+type weeklyConfig struct {
+	// TimeZone is the local time zone.
+	TimeZone string `yaml:"time_zone"`
+
+	// Days of the week.
+
+	Sunday    dayConfig `yaml:"sun,omitempty"`
+	Monday    dayConfig `yaml:"mon,omitempty"`
+	Tuesday   dayConfig `yaml:"tue,omitempty"`
+	Wednesday dayConfig `yaml:"wed,omitempty"`
+	Thursday  dayConfig `yaml:"thu,omitempty"`
+	Friday    dayConfig `yaml:"fri,omitempty"`
+	Saturday  dayConfig `yaml:"sat,omitempty"`
+}
+
+// dayConfig is the YAML configuration structure of dayRange.
+type dayConfig struct {
+	Start timeutil.Duration `yaml:"start"`
+	End   timeutil.Duration `yaml:"end"`
+}
+
+// maxDayRange is the maximum value for day range end.
+const maxDayRange = 24 * time.Hour
+
+// validate returns the day range rounding errors, if any.
+func (w *Weekly) validate(r dayRange) (err error) {
+	defer func() { err = errors.Annotate(err, "bad day range: %w") }()
+
+	err = r.validate()
+	if err != nil {
+		// Don't wrap the error since it's informative enough as is.
+		return err
+	}
+
+	start := r.start.Truncate(time.Minute)
+	end := r.end.Truncate(time.Minute)
+
+	switch {
+	case start != r.start:
+		return fmt.Errorf("start %s isn't rounded to minutes", r.start)
+	case end != r.end:
+		return fmt.Errorf("end %s isn't rounded to minutes", r.end)
+	default:
+		return nil
+	}
+}
+
+// type check
+var _ yaml.Marshaler = (*Weekly)(nil)
+
+// MarshalYAML implements the [yaml.Marshaler] interface for *Weekly.
+func (w *Weekly) MarshalYAML() (v any, err error) {
+	return weeklyConfig{
+		TimeZone: w.location.String(),
+		Sunday: dayConfig{
+			Start: timeutil.Duration{Duration: w.days[time.Sunday].start},
+			End:   timeutil.Duration{Duration: w.days[time.Sunday].end},
+		},
+		Monday: dayConfig{
+			Start: timeutil.Duration{Duration: w.days[time.Monday].start},
+			End:   timeutil.Duration{Duration: w.days[time.Monday].end},
+		},
+		Tuesday: dayConfig{
+			Start: timeutil.Duration{Duration: w.days[time.Tuesday].start},
+			End:   timeutil.Duration{Duration: w.days[time.Tuesday].end},
+		},
+		Wednesday: dayConfig{
+			Start: timeutil.Duration{Duration: w.days[time.Wednesday].start},
+			End:   timeutil.Duration{Duration: w.days[time.Wednesday].end},
+		},
+		Thursday: dayConfig{
+			Start: timeutil.Duration{Duration: w.days[time.Thursday].start},
+			End:   timeutil.Duration{Duration: w.days[time.Thursday].end},
+		},
+		Friday: dayConfig{
+			Start: timeutil.Duration{Duration: w.days[time.Friday].start},
+			End:   timeutil.Duration{Duration: w.days[time.Friday].end},
+		},
+		Saturday: dayConfig{
+			Start: timeutil.Duration{Duration: w.days[time.Saturday].start},
+			End:   timeutil.Duration{Duration: w.days[time.Saturday].end},
+		},
+	}, nil
+}
+
+// dayRange represents a single interval within a day.  The interval begins at
+// start and ends before end.  That is, it contains a time point T if start <=
+// T < end.
+type dayRange struct {
+	// start is an offset from the beginning of the day.  It must be greater
+	// than or equal to zero and less than 24h.
+	start time.Duration
+
+	// end is an offset from the beginning of the day.  It must be greater than
+	// or equal to zero and less than or equal to 24h.
+	end time.Duration
+}
+
+// validate returns the day range validation errors, if any.
+func (r dayRange) validate() (err error) {
+	switch {
+	case r == dayRange{}:
+		return nil
+	case r.start < 0:
+		return fmt.Errorf("start %s is negative", r.start)
+	case r.end < 0:
+		return fmt.Errorf("end %s is negative", r.end)
+	case r.start >= r.end:
+		return fmt.Errorf("start %s is greater or equal to end %s", r.start, r.end)
+	case r.start >= maxDayRange:
+		return fmt.Errorf("start %s is greater or equal to %s", r.start, maxDayRange)
+	case r.end > maxDayRange:
+		return fmt.Errorf("end %s is greater than %s", r.end, maxDayRange)
+	default:
+		return nil
+	}
+}
+
+// contains returns true if start <= offset < end, where offset is the time
+// duration from the beginning of the day.
+func (r *dayRange) contains(offset time.Duration) (ok bool) {
+	return r.start <= offset && offset < r.end
+}
diff --git a/internal/schedule/schedule_internal_test.go b/internal/schedule/schedule_internal_test.go
new file mode 100644
index 00000000..f500524e
--- /dev/null
+++ b/internal/schedule/schedule_internal_test.go
@@ -0,0 +1,371 @@
+package schedule
+
+import (
+	"testing"
+	"time"
+
+	"github.com/AdguardTeam/golibs/testutil"
+	"github.com/AdguardTeam/golibs/timeutil"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"gopkg.in/yaml.v3"
+)
+
+func TestWeekly_Contains(t *testing.T) {
+	baseTime := time.Date(2021, 1, 1, 0, 0, 0, 0, time.UTC)
+	otherTime := baseTime.Add(1 * timeutil.Day)
+
+	// NOTE: In the Etc area the sign of the offsets is flipped.  So, Etc/GMT-3
+	// is actually UTC+03:00.
+	otherTZ := time.FixedZone("Etc/GMT-3", 3*60*60)
+
+	// baseSchedule, 12:00 to 14:00.
+	baseSchedule := &Weekly{
+		days: [7]dayRange{
+			time.Friday: {start: 12 * time.Hour, end: 14 * time.Hour},
+		},
+		location: time.UTC,
+	}
+
+	// allDaySchedule, 00:00 to 24:00.
+	allDaySchedule := &Weekly{
+		days: [7]dayRange{
+			time.Friday: {start: 0, end: 24 * time.Hour},
+		},
+		location: time.UTC,
+	}
+
+	// oneMinSchedule, 00:00 to 00:01.
+	oneMinSchedule := &Weekly{
+		days: [7]dayRange{
+			time.Friday: {start: 0, end: 1 * time.Minute},
+		},
+		location: time.UTC,
+	}
+
+	testCases := []struct {
+		schedule *Weekly
+		assert   assert.BoolAssertionFunc
+		t        time.Time
+		name     string
+	}{{
+		schedule: EmptyWeekly(),
+		assert:   assert.False,
+		t:        baseTime,
+		name:     "empty",
+	}, {
+		schedule: allDaySchedule,
+		assert:   assert.True,
+		t:        baseTime,
+		name:     "same_day_all_day",
+	}, {
+		schedule: baseSchedule,
+		assert:   assert.True,
+		t:        baseTime.Add(13 * time.Hour),
+		name:     "same_day_inside",
+	}, {
+		schedule: baseSchedule,
+		assert:   assert.False,
+		t:        baseTime.Add(11 * time.Hour),
+		name:     "same_day_outside",
+	}, {
+		schedule: allDaySchedule,
+		assert:   assert.True,
+		t:        baseTime.Add(24*time.Hour - time.Second),
+		name:     "same_day_last_second",
+	}, {
+		schedule: allDaySchedule,
+		assert:   assert.False,
+		t:        otherTime,
+		name:     "other_day_all_day",
+	}, {
+		schedule: baseSchedule,
+		assert:   assert.False,
+		t:        otherTime.Add(13 * time.Hour),
+		name:     "other_day_inside",
+	}, {
+		schedule: baseSchedule,
+		assert:   assert.False,
+		t:        otherTime.Add(11 * time.Hour),
+		name:     "other_day_outside",
+	}, {
+		schedule: baseSchedule,
+		assert:   assert.True,
+		t:        baseTime.Add(13 * time.Hour).In(otherTZ),
+		name:     "same_day_inside_other_tz",
+	}, {
+		schedule: baseSchedule,
+		assert:   assert.False,
+		t:        baseTime.Add(11 * time.Hour).In(otherTZ),
+		name:     "same_day_outside_other_tz",
+	}, {
+		schedule: oneMinSchedule,
+		assert:   assert.True,
+		t:        baseTime,
+		name:     "one_minute_beginning",
+	}, {
+		schedule: oneMinSchedule,
+		assert:   assert.True,
+		t:        baseTime.Add(1*time.Minute - 1),
+		name:     "one_minute_end",
+	}, {
+		schedule: oneMinSchedule,
+		assert:   assert.False,
+		t:        baseTime.Add(1 * time.Minute),
+		name:     "one_minute_past_end",
+	}}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			tc.assert(t, tc.schedule.Contains(tc.t))
+		})
+	}
+}
+
+const brusselsSunday = `
+sun:
+    start: 12h
+    end: 14h
+time_zone: Europe/Brussels
+`
+
+func TestWeekly_UnmarshalYAML(t *testing.T) {
+	const (
+		sameTime = `
+sun:
+    start: 9h
+    end: 9h
+`
+		negativeStart = `
+sun:
+    start: -1h
+    end: 1h
+`
+		badTZ = `
+time_zone: "bad_timezone"
+`
+		badYAML = `
+yaml: "bad"
+yaml: "bad"
+`
+	)
+
+	brusseltsTZ, err := time.LoadLocation("Europe/Brussels")
+	require.NoError(t, err)
+
+	brusselsWeekly := &Weekly{
+		days: [7]dayRange{{
+			start: time.Hour * 12,
+			end:   time.Hour * 14,
+		}},
+		location: brusseltsTZ,
+	}
+
+	testCases := []struct {
+		name       string
+		wantErrMsg string
+		data       []byte
+		want       *Weekly
+	}{{
+		name:       "empty",
+		wantErrMsg: "",
+		data:       []byte(""),
+		want:       &Weekly{},
+	}, {
+		name:       "null",
+		wantErrMsg: "",
+		data:       []byte("null"),
+		want:       &Weekly{},
+	}, {
+		name:       "brussels_sunday",
+		wantErrMsg: "",
+		data:       []byte(brusselsSunday),
+		want:       brusselsWeekly,
+	}, {
+		name:       "start_equal_end",
+		wantErrMsg: "weekday Sunday: bad day range: start 9h0m0s is greater or equal to end 9h0m0s",
+		data:       []byte(sameTime),
+		want:       &Weekly{},
+	}, {
+		name:       "start_negative",
+		wantErrMsg: "weekday Sunday: bad day range: start -1h0m0s is negative",
+		data:       []byte(negativeStart),
+		want:       &Weekly{},
+	}, {
+		name:       "bad_time_zone",
+		wantErrMsg: "unknown time zone bad_timezone",
+		data:       []byte(badTZ),
+		want:       &Weekly{},
+	}, {
+		name:       "bad_yaml",
+		wantErrMsg: "yaml: unmarshal errors:\n  line 3: mapping key \"yaml\" already defined at line 2",
+		data:       []byte(badYAML),
+		want:       &Weekly{},
+	}}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			w := &Weekly{}
+			err = yaml.Unmarshal(tc.data, w)
+			testutil.AssertErrorMsg(t, tc.wantErrMsg, err)
+
+			assert.Equal(t, tc.want, w)
+		})
+	}
+}
+
+func TestWeekly_MarshalYAML(t *testing.T) {
+	brusselsTZ, err := time.LoadLocation("Europe/Brussels")
+	require.NoError(t, err)
+
+	brusselsWeekly := &Weekly{
+		days: [7]dayRange{time.Sunday: {
+			start: time.Hour * 12,
+			end:   time.Hour * 14,
+		}},
+		location: brusselsTZ,
+	}
+
+	testCases := []struct {
+		name string
+		data []byte
+		want *Weekly
+	}{{
+		name: "empty",
+		data: []byte(""),
+		want: &Weekly{},
+	}, {
+		name: "null",
+		data: []byte("null"),
+		want: &Weekly{},
+	}, {
+		name: "brussels_sunday",
+		data: []byte(brusselsSunday),
+		want: brusselsWeekly,
+	}}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			var data []byte
+			data, err = yaml.Marshal(brusselsWeekly)
+			require.NoError(t, err)
+
+			w := &Weekly{}
+			err = yaml.Unmarshal(data, w)
+			require.NoError(t, err)
+
+			assert.Equal(t, brusselsWeekly, w)
+		})
+	}
+}
+
+func TestWeekly_Validate(t *testing.T) {
+	testCases := []struct {
+		name       string
+		in         dayRange
+		wantErrMsg string
+	}{{
+		name:       "empty",
+		wantErrMsg: "",
+		in:         dayRange{},
+	}, {
+		name:       "start_seconds",
+		wantErrMsg: "bad day range: start 1s isn't rounded to minutes",
+		in: dayRange{
+			start: time.Second,
+			end:   time.Hour,
+		},
+	}, {
+		name:       "end_seconds",
+		wantErrMsg: "bad day range: end 1s isn't rounded to minutes",
+		in: dayRange{
+			start: 0,
+			end:   time.Second,
+		},
+	}}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			w := &Weekly{}
+			err := w.validate(tc.in)
+
+			testutil.AssertErrorMsg(t, tc.wantErrMsg, err)
+		})
+	}
+}
+
+func TestDayRange_Validate(t *testing.T) {
+	testCases := []struct {
+		name       string
+		in         dayRange
+		wantErrMsg string
+	}{{
+		name:       "empty",
+		wantErrMsg: "",
+		in:         dayRange{},
+	}, {
+		name:       "valid",
+		wantErrMsg: "",
+		in: dayRange{
+			start: time.Hour,
+			end:   time.Hour * 2,
+		},
+	}, {
+		name:       "valid_end_max",
+		wantErrMsg: "",
+		in: dayRange{
+			start: 0,
+			end:   time.Hour * 24,
+		},
+	}, {
+		name:       "start_negative",
+		wantErrMsg: "start -1h0m0s is negative",
+		in: dayRange{
+			start: time.Hour * -1,
+			end:   time.Hour * 2,
+		},
+	}, {
+		name:       "end_negative",
+		wantErrMsg: "end -1h0m0s is negative",
+		in: dayRange{
+			start: 0,
+			end:   time.Hour * -1,
+		},
+	}, {
+		name:       "start_equal_end",
+		wantErrMsg: "start 1h0m0s is greater or equal to end 1h0m0s",
+		in: dayRange{
+			start: time.Hour,
+			end:   time.Hour,
+		},
+	}, {
+		name:       "start_greater_end",
+		wantErrMsg: "start 2h0m0s is greater or equal to end 1h0m0s",
+		in: dayRange{
+			start: time.Hour * 2,
+			end:   time.Hour,
+		},
+	}, {
+		name:       "start_equal_max",
+		wantErrMsg: "start 24h0m0s is greater or equal to 24h0m0s",
+		in: dayRange{
+			start: time.Hour * 24,
+			end:   time.Hour * 48,
+		},
+	}, {
+		name:       "end_greater_max",
+		wantErrMsg: "end 48h0m0s is greater than 24h0m0s",
+		in: dayRange{
+			start: 0,
+			end:   time.Hour * 48,
+		},
+	}}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			err := tc.in.validate()
+
+			testutil.AssertErrorMsg(t, tc.wantErrMsg, err)
+		})
+	}
+}