all: sync with master

internal/aghalg/ringbuffer.go

@@ -1,23 +1,15 @@
 package aghalg
 
-import (
-	"github.com/AdguardTeam/golibs/errors"
-)
-
 // RingBuffer is the implementation of ring buffer data structure.
 type RingBuffer[T any] struct {
 	buf  []T
-	cur  int
+	cur  uint
 	full bool
 }
 
 // NewRingBuffer initializes the new instance of ring buffer.  size must be
 // greater or equal to zero.
-func NewRingBuffer[T any](size int) (rb *RingBuffer[T]) {
-	if size < 0 {
-		panic(errors.Error("ring buffer: size must be greater or equal to zero"))
-	}
-
+func NewRingBuffer[T any](size uint) (rb *RingBuffer[T]) {
 	return &RingBuffer[T]{
 		buf: make([]T, size),
 	}
@@ -30,7 +22,7 @@ func (rb *RingBuffer[T]) Append(e T) {
 	}
 
 	rb.buf[rb.cur] = e
-	rb.cur = (rb.cur + 1) % cap(rb.buf)
+	rb.cur = (rb.cur + 1) % uint(cap(rb.buf))
 	if rb.cur == 0 {
 		rb.full = true
 	}
@@ -87,12 +79,12 @@ func (rb *RingBuffer[T]) splitCur() (before, after []T) {
 }
 
 // Len returns a length of the buffer.
-func (rb *RingBuffer[T]) Len() (l int) {
+func (rb *RingBuffer[T]) Len() (l uint) {
 	if !rb.full {
 		return rb.cur
 	}
 
-	return cap(rb.buf)
+	return uint(cap(rb.buf))
 }
 
 // Clear clears the buffer.

internal/aghalg/ringbuffer_test.go

@@ -9,13 +9,13 @@ import (
 )
 
 // elements is a helper function that returns n elements of the buffer.
-func elements(b *aghalg.RingBuffer[int], n int, reverse bool) (es []int) {
+func elements(b *aghalg.RingBuffer[int], n uint, reverse bool) (es []int) {
 	fn := b.Range
 	if reverse {
 		fn = b.ReverseRange
 	}
 
-	i := 0
+	var i uint
 	fn(func(e int) (cont bool) {
 		if i >= n {
 			return false
@@ -42,19 +42,14 @@ func TestNewRingBuffer(t *testing.T) {
 		assert.Zero(t, b.Len())
 	})
 
-	t.Run("negative_size", func(t *testing.T) {
-		assert.PanicsWithError(t, "ring buffer: size must be greater or equal to zero", func() {
-			aghalg.NewRingBuffer[int](-5)
-		})
-	})
-
 	t.Run("zero", func(t *testing.T) {
 		b := aghalg.NewRingBuffer[int](0)
 		for i := 0; i < 10; i++ {
 			b.Append(i)
-			assert.Equal(t, 0, b.Len())
-			assert.Empty(t, elements(b, b.Len(), false))
-			assert.Empty(t, elements(b, b.Len(), true))
+			bufLen := b.Len()
+			assert.EqualValues(t, 0, bufLen)
+			assert.Empty(t, elements(b, bufLen, false))
+			assert.Empty(t, elements(b, bufLen, true))
 		}
 	})
 
@@ -62,9 +57,10 @@ func TestNewRingBuffer(t *testing.T) {
 		b := aghalg.NewRingBuffer[int](1)
 		for i := 0; i < 10; i++ {
 			b.Append(i)
-			assert.Equal(t, 1, b.Len())
-			assert.Equal(t, []int{i}, elements(b, b.Len(), false))
-			assert.Equal(t, []int{i}, elements(b, b.Len(), true))
+			bufLen := b.Len()
+			assert.EqualValues(t, 1, bufLen)
+			assert.Equal(t, []int{i}, elements(b, bufLen, false))
+			assert.Equal(t, []int{i}, elements(b, bufLen, true))
 		}
 	})
 }
@@ -78,7 +74,7 @@ func TestRingBuffer_Range(t *testing.T) {
 		name   string
 		want   []int
 		count  int
-		length int
+		length uint
 	}{{
 		name:   "three",
 		count:  3,
@@ -163,11 +159,11 @@ func TestRingBuffer_Range_increment(t *testing.T) {
 	for i, tc := range testCases {
 		t.Run(tc.name, func(t *testing.T) {
 			b.Append(i)
-
-			assert.Equal(t, tc.want, elements(b, b.Len(), false))
+			bufLen := b.Len()
+			assert.Equal(t, tc.want, elements(b, bufLen, false))
 
 			slices.Reverse(tc.want)
-			assert.Equal(t, tc.want, elements(b, b.Len(), true))
+			assert.Equal(t, tc.want, elements(b, bufLen, true))
 		})
 	}
 }

internal/aghchan/aghchan.go

@@ -1,33 +0,0 @@
-// 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/aghnet/hostscontainer.go

@@ -1,65 +1,23 @@
 package aghnet
 
 import (
-	"context"
 	"fmt"
 	"io"
 	"io/fs"
 	"net/netip"
 	"path"
-	"strings"
 	"sync/atomic"
 
 	"github.com/AdguardTeam/AdGuardHome/internal/aghos"
-	"github.com/AdguardTeam/dnsproxy/upstream"
 	"github.com/AdguardTeam/golibs/errors"
 	"github.com/AdguardTeam/golibs/hostsfile"
 	"github.com/AdguardTeam/golibs/log"
-	"golang.org/x/exp/maps"
-	"golang.org/x/exp/slices"
 )
 
-// DefaultHostsPaths returns the slice of paths default for the operating system
-// to files and directories which are containing the hosts database.  The result
-// is intended to be used within fs.FS so the initial slash is omitted.
-func DefaultHostsPaths() (paths []string) {
-	return defaultHostsPaths()
-}
-
-// MatchAddr returns the records for the IP address.
-func (hc *HostsContainer) MatchAddr(ip netip.Addr) (recs []*hostsfile.Record) {
-	cur := hc.current.Load()
-	if cur == nil {
-		return nil
-	}
-
-	return cur.addrs[ip]
-}
-
-// MatchName returns the records for the hostname.
-func (hc *HostsContainer) MatchName(name string) (recs []*hostsfile.Record) {
-	cur := hc.current.Load()
-	if cur != nil {
-		recs = cur.names[name]
-	}
-
-	return recs
-}
-
 // hostsContainerPrefix is a prefix for logging and wrapping errors in
 // HostsContainer's methods.
 const hostsContainerPrefix = "hosts container"
 
-// Hosts is a map of IP addresses to the records, as it primarily stored in the
-// [HostsContainer].  It should not be accessed for writing since it may be read
-// concurrently, users should clone it before modifying.
-//
-// The order of records for each address is preserved from original files, but
-// the order of the addresses, being a map key, is not.
-//
-// TODO(e.burkov):  Probably, this should be a sorted slice of records.
-type Hosts map[netip.Addr][]*hostsfile.Record
-
 // HostsContainer stores the relevant hosts database provided by the OS and
 // processes both A/AAAA and PTR DNS requests for those.
 type HostsContainer struct {
@@ -67,10 +25,10 @@ type HostsContainer struct {
 	done chan struct{}
 
 	// updates is the channel for receiving updated hosts.
-	updates chan Hosts
+	updates chan *hostsfile.DefaultStorage
 
 	// current is the last set of hosts parsed.
-	current atomic.Pointer[hostsIndex]
+	current atomic.Pointer[hostsfile.DefaultStorage]
 
 	// fsys is the working file system to read hosts files from.
 	fsys fs.FS
@@ -111,7 +69,7 @@ func NewHostsContainer(
 
 	hc = &HostsContainer{
 		done:     make(chan struct{}, 1),
-		updates:  make(chan Hosts, 1),
+		updates:  make(chan *hostsfile.DefaultStorage, 1),
 		fsys:     fsys,
 		watcher:  w,
 		patterns: patterns,
@@ -152,11 +110,25 @@ func (hc *HostsContainer) Close() (err error) {
 	return err
 }
 
-// Upd returns the channel into which the updates are sent.
-func (hc *HostsContainer) Upd() (updates <-chan Hosts) {
+// Upd returns the channel into which the updates are sent.  The updates
+// themselves must not be modified.
+func (hc *HostsContainer) Upd() (updates <-chan *hostsfile.DefaultStorage) {
 	return hc.updates
 }
 
+// type check
+var _ hostsfile.Storage = (*HostsContainer)(nil)
+
+// ByAddr implements the [hostsfile.Storage] interface for *HostsContainer.
+func (hc *HostsContainer) ByAddr(addr netip.Addr) (names []string) {
+	return hc.current.Load().ByAddr(addr)
+}
+
+// ByName implements the [hostsfile.Storage] interface for *HostsContainer.
+func (hc *HostsContainer) ByName(name string) (addrs []netip.Addr) {
+	return hc.current.Load().ByName(name)
+}
+
 // pathsToPatterns converts paths into patterns compatible with fs.Glob.
 func pathsToPatterns(fsys fs.FS, paths []string) (patterns []string, err error) {
 	for i, p := range paths {
@@ -167,7 +139,7 @@ func pathsToPatterns(fsys fs.FS, paths []string) (patterns []string, err error)
 				continue
 			}
 
-			// Don't put a filename here since it's already added by fs.Stat.
+			// Don't put a filename here since it's already added by [fs.Stat].
 			return nil, fmt.Errorf("path at index %d: %w", i, err)
 		}
 
@@ -209,7 +181,7 @@ func (hc *HostsContainer) handleEvents() {
 }
 
 // sendUpd tries to send the parsed data to the ch.
-func (hc *HostsContainer) sendUpd(recs Hosts) {
+func (hc *HostsContainer) sendUpd(recs *hostsfile.DefaultStorage) {
 	log.Debug("%s: sending upd", hostsContainerPrefix)
 
 	ch := hc.updates
@@ -226,67 +198,6 @@ func (hc *HostsContainer) sendUpd(recs Hosts) {
 	}
 }
 
-// hostsIndex is a [hostsfile.Set] to enumerate all the records.
-type hostsIndex struct {
-	// addrs maps IP addresses to the records.
-	addrs Hosts
-
-	// names maps hostnames to the records.
-	names map[string][]*hostsfile.Record
-}
-
-// walk is a file walking function for hostsIndex.
-func (idx *hostsIndex) walk(r io.Reader) (patterns []string, cont bool, err error) {
-	return nil, true, hostsfile.Parse(idx, r, nil)
-}
-
-// type check
-var _ hostsfile.Set = (*hostsIndex)(nil)
-
-// Add implements the [hostsfile.Set] interface for *hostsIndex.
-func (idx *hostsIndex) Add(rec *hostsfile.Record) {
-	idx.addrs[rec.Addr] = append(idx.addrs[rec.Addr], rec)
-	for _, name := range rec.Names {
-		idx.names[name] = append(idx.names[name], rec)
-	}
-}
-
-// type check
-var _ hostsfile.HandleSet = (*hostsIndex)(nil)
-
-// HandleInvalid implements the [hostsfile.HandleSet] interface for *hostsIndex.
-func (idx *hostsIndex) HandleInvalid(src string, _ []byte, err error) {
-	lineErr := &hostsfile.LineError{}
-	if !errors.As(err, &lineErr) {
-		// Must not happen if idx passed to [hostsfile.Parse].
-		return
-	} else if errors.Is(lineErr, hostsfile.ErrEmptyLine) {
-		// Ignore empty lines.
-		return
-	}
-
-	log.Info("%s: warning: parsing %q: %s", hostsContainerPrefix, src, lineErr)
-}
-
-// equalRecs is an equality function for [*hostsfile.Record].
-func equalRecs(a, b *hostsfile.Record) (ok bool) {
-	return a.Addr == b.Addr && a.Source == b.Source && slices.Equal(a.Names, b.Names)
-}
-
-// equalRecSlices is an equality function for slices of [*hostsfile.Record].
-func equalRecSlices(a, b []*hostsfile.Record) (ok bool) { return slices.EqualFunc(a, b, equalRecs) }
-
-// Equal returns true if indexes are equal.
-func (idx *hostsIndex) Equal(other *hostsIndex) (ok bool) {
-	if idx == nil {
-		return other == nil
-	} else if other == nil {
-		return false
-	}
-
-	return maps.EqualFunc(idx.addrs, other.addrs, equalRecSlices)
-}
-
 // refresh gets the data from specified files and propagates the updates if
 // needed.
 //
@@ -294,63 +205,22 @@ func (idx *hostsIndex) Equal(other *hostsIndex) (ok bool) {
 func (hc *HostsContainer) refresh() (err error) {
 	log.Debug("%s: refreshing", hostsContainerPrefix)
 
-	var addrLen, nameLen int
-	last := hc.current.Load()
-	if last != nil {
-		addrLen, nameLen = len(last.addrs), len(last.names)
-	}
-	idx := &hostsIndex{
-		addrs: make(Hosts, addrLen),
-		names: make(map[string][]*hostsfile.Record, nameLen),
-	}
-
-	_, err = aghos.FileWalker(idx.walk).Walk(hc.fsys, hc.patterns...)
+	// The error is always nil here since no readers passed.
+	strg, _ := hostsfile.NewDefaultStorage()
+	_, err = aghos.FileWalker(func(r io.Reader) (patterns []string, cont bool, err error) {
+		// Don't wrap the error since it's already informative enough as is.
+		return nil, true, hostsfile.Parse(strg, r, nil)
+	}).Walk(hc.fsys, hc.patterns...)
 	if err != nil {
 		// Don't wrap the error since it's informative enough as is.
 		return err
 	}
 
-	// TODO(e.burkov):  Serialize updates using time.
-	if !last.Equal(idx) {
-		hc.current.Store(idx)
-		hc.sendUpd(idx.addrs)
+	// TODO(e.burkov):  Serialize updates using [time.Time].
+	if !hc.current.Load().Equal(strg) {
+		hc.current.Store(strg)
+		hc.sendUpd(strg)
 	}
 
 	return nil
 }
-
-// type check
-var _ upstream.Resolver = (*HostsContainer)(nil)
-
-// LookupNetIP implements the [upstream.Resolver] interface for *HostsContainer.
-func (hc *HostsContainer) LookupNetIP(
-	ctx context.Context,
-	network string,
-	hostname string,
-) (addrs []netip.Addr, err error) {
-	// TODO(e.burkov):  Think of extracting this logic to a golibs function if
-	// needed anywhere else.
-	var isDesiredProto func(ip netip.Addr) (ok bool)
-	switch network {
-	case "ip4":
-		isDesiredProto = (netip.Addr).Is4
-	case "ip6":
-		isDesiredProto = (netip.Addr).Is6
-	case "ip":
-		isDesiredProto = func(ip netip.Addr) (ok bool) { return true }
-	default:
-		return nil, fmt.Errorf("unsupported network: %q", network)
-	}
-
-	idx := hc.current.Load()
-	recs := idx.names[strings.ToLower(hostname)]
-
-	addrs = make([]netip.Addr, 0, len(recs))
-	for _, rec := range recs {
-		if isDesiredProto(rec.Addr) {
-			addrs = append(addrs, rec.Addr)
-		}
-	}
-
-	return slices.Clip(addrs), nil
-}

internal/aghnet/hostscontainer_linux.go

@@ -1,17 +0,0 @@
-//go:build linux
-
-package aghnet
-
-import (
-	"github.com/AdguardTeam/AdGuardHome/internal/aghos"
-)
-
-func defaultHostsPaths() (paths []string) {
-	paths = []string{"etc/hosts"}
-
-	if aghos.IsOpenWrt() {
-		paths = append(paths, "tmp/hosts")
-	}
-
-	return paths
-}

internal/aghnet/hostscontainer_others.go

@@ -1,7 +0,0 @@
-//go:build !(windows || linux)
-
-package aghnet
-
-func defaultHostsPaths() (paths []string) {
-	return []string{"etc/hosts"}
-}

internal/aghnet/hostscontainer_test.go

@@ -3,13 +3,11 @@ package aghnet_test
 import (
 	"net/netip"
 	"path"
-	"path/filepath"
 	"sync/atomic"
 	"testing"
 	"testing/fstest"
 	"time"
 
-	"github.com/AdguardTeam/AdGuardHome/internal/aghchan"
 	"github.com/AdguardTeam/AdGuardHome/internal/aghnet"
 	"github.com/AdguardTeam/AdGuardHome/internal/aghtest"
 	"github.com/AdguardTeam/golibs/errors"
@@ -20,139 +18,6 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
-// nl is a newline character.
-const nl = "\n"
-
-// Variables mirroring the etc_hosts file from testdata.
-var (
-	addr1000 = netip.MustParseAddr("1.0.0.0")
-	addr1001 = netip.MustParseAddr("1.0.0.1")
-	addr1002 = netip.MustParseAddr("1.0.0.2")
-	addr1003 = netip.MustParseAddr("1.0.0.3")
-	addr1004 = netip.MustParseAddr("1.0.0.4")
-	addr1357 = netip.MustParseAddr("1.3.5.7")
-	addr4216 = netip.MustParseAddr("4.2.1.6")
-	addr7531 = netip.MustParseAddr("7.5.3.1")
-
-	addr0  = netip.MustParseAddr("::")
-	addr1  = netip.MustParseAddr("::1")
-	addr2  = netip.MustParseAddr("::2")
-	addr3  = netip.MustParseAddr("::3")
-	addr4  = netip.MustParseAddr("::4")
-	addr42 = netip.MustParseAddr("::42")
-	addr13 = netip.MustParseAddr("::13")
-	addr31 = netip.MustParseAddr("::31")
-
-	hostsSrc = "./" + filepath.Join("./testdata", "etc_hosts")
-
-	testHosts = map[netip.Addr][]*hostsfile.Record{
-		addr1000: {{
-			Addr:   addr1000,
-			Source: hostsSrc,
-			Names:  []string{"hello", "hello.world"},
-		}, {
-			Addr:   addr1000,
-			Source: hostsSrc,
-			Names:  []string{"hello.world.again"},
-		}, {
-			Addr:   addr1000,
-			Source: hostsSrc,
-			Names:  []string{"hello.world"},
-		}},
-		addr1001: {{
-			Addr:   addr1001,
-			Source: hostsSrc,
-			Names:  []string{"simplehost"},
-		}, {
-			Addr:   addr1001,
-			Source: hostsSrc,
-			Names:  []string{"simplehost"},
-		}},
-		addr1002: {{
-			Addr:   addr1002,
-			Source: hostsSrc,
-			Names:  []string{"a.whole", "lot.of", "aliases", "for.testing"},
-		}},
-		addr1003: {{
-			Addr:   addr1003,
-			Source: hostsSrc,
-			Names:  []string{"*"},
-		}},
-		addr1004: {{
-			Addr:   addr1004,
-			Source: hostsSrc,
-			Names:  []string{"*.com"},
-		}},
-		addr1357: {{
-			Addr:   addr1357,
-			Source: hostsSrc,
-			Names:  []string{"domain4", "domain4.alias"},
-		}},
-		addr7531: {{
-			Addr:   addr7531,
-			Source: hostsSrc,
-			Names:  []string{"domain4.alias", "domain4"},
-		}},
-		addr4216: {{
-			Addr:   addr4216,
-			Source: hostsSrc,
-			Names:  []string{"domain", "domain.alias"},
-		}},
-		addr0: {{
-			Addr:   addr0,
-			Source: hostsSrc,
-			Names:  []string{"hello", "hello.world"},
-		}, {
-			Addr:   addr0,
-			Source: hostsSrc,
-			Names:  []string{"hello.world.again"},
-		}, {
-			Addr:   addr0,
-			Source: hostsSrc,
-			Names:  []string{"hello.world"},
-		}},
-		addr1: {{
-			Addr:   addr1,
-			Source: hostsSrc,
-			Names:  []string{"simplehost"},
-		}, {
-			Addr:   addr1,
-			Source: hostsSrc,
-			Names:  []string{"simplehost"},
-		}},
-		addr2: {{
-			Addr:   addr2,
-			Source: hostsSrc,
-			Names:  []string{"a.whole", "lot.of", "aliases", "for.testing"},
-		}},
-		addr3: {{
-			Addr:   addr3,
-			Source: hostsSrc,
-			Names:  []string{"*"},
-		}},
-		addr4: {{
-			Addr:   addr4,
-			Source: hostsSrc,
-			Names:  []string{"*.com"},
-		}},
-		addr42: {{
-			Addr:   addr42,
-			Source: hostsSrc,
-			Names:  []string{"domain.alias", "domain"},
-		}},
-		addr13: {{
-			Addr:   addr13,
-			Source: hostsSrc,
-			Names:  []string{"domain6", "domain6.alias"},
-		}},
-		addr31: {{
-			Addr:   addr31,
-			Source: hostsSrc,
-			Names:  []string{"domain6.alias", "domain6"},
-		}},
-	}
-)
-
 func TestNewHostsContainer(t *testing.T) {
 	const dirname = "dir"
 	const filename = "file1"
@@ -267,7 +132,21 @@ func TestHostsContainer_refresh(t *testing.T) {
 	anotherIPStr := "1.2.3.4"
 	anotherIP := netip.MustParseAddr(anotherIPStr)
 
-	testFS := fstest.MapFS{"dir/file1": &fstest.MapFile{Data: []byte(ipStr + ` hostname` + nl)}}
+	r1 := &hostsfile.Record{
+		Addr:   ip,
+		Source: "file1",
+		Names:  []string{"hostname"},
+	}
+	r2 := &hostsfile.Record{
+		Addr:   anotherIP,
+		Source: "file2",
+		Names:  []string{"alias"},
+	}
+
+	r1Data, _ := r1.MarshalText()
+	r2Data, _ := r2.MarshalText()
+
+	testFS := fstest.MapFS{"dir/file1": &fstest.MapFile{Data: r1Data}}
 
 	// event is a convenient alias for an empty struct{} to emit test events.
 	type event = struct{}
@@ -289,172 +168,47 @@ func TestHostsContainer_refresh(t *testing.T) {
 	require.NoError(t, err)
 	testutil.CleanupAndRequireSuccess(t, hc.Close)
 
-	checkRefresh := func(t *testing.T, want aghnet.Hosts) {
-		t.Helper()
-
-		upd, ok := aghchan.MustReceive(hc.Upd(), 1*time.Second)
-		require.True(t, ok)
-
-		assert.Equal(t, want, upd)
-	}
+	strg, _ := hostsfile.NewDefaultStorage()
+	strg.Add(r1)
 
 	t.Run("initial_refresh", func(t *testing.T) {
-		checkRefresh(t, aghnet.Hosts{
-			ip: {{
-				Addr:   ip,
-				Source: "file1",
-				Names:  []string{"hostname"},
-			}},
-		})
+		upd, ok := testutil.RequireReceive(t, hc.Upd(), 1*time.Second)
+		require.True(t, ok)
+
+		assert.True(t, strg.Equal(upd))
 	})
 
+	strg.Add(r2)
+
 	t.Run("second_refresh", func(t *testing.T) {
-		testFS["dir/file2"] = &fstest.MapFile{Data: []byte(anotherIPStr + ` alias` + nl)}
+		testFS["dir/file2"] = &fstest.MapFile{Data: r2Data}
 		eventsCh <- event{}
 
-		checkRefresh(t, aghnet.Hosts{
-			ip: {{
-				Addr:   ip,
-				Source: "file1",
-				Names:  []string{"hostname"},
-			}},
-			anotherIP: {{
-				Addr:   anotherIP,
-				Source: "file2",
-				Names:  []string{"alias"},
-			}},
-		})
+		upd, ok := testutil.RequireReceive(t, hc.Upd(), 1*time.Second)
+		require.True(t, ok)
+
+		assert.True(t, strg.Equal(upd))
 	})
 
 	t.Run("double_refresh", func(t *testing.T) {
 		// Make a change once.
-		testFS["dir/file1"] = &fstest.MapFile{Data: []byte(ipStr + ` alias` + nl)}
+		testFS["dir/file1"] = &fstest.MapFile{Data: []byte(ipStr + " alias\n")}
 		eventsCh <- event{}
 
 		// Require the changes are written.
-		require.Eventually(t, func() bool {
-			ips := hc.MatchName("hostname")
+		current, ok := testutil.RequireReceive(t, hc.Upd(), 1*time.Second)
+		require.True(t, ok)
 
-			return len(ips) == 0
-		}, 5*time.Second, time.Second/2)
+		require.Empty(t, current.ByName("hostname"))
 
 		// Make a change again.
-		testFS["dir/file2"] = &fstest.MapFile{Data: []byte(ipStr + ` hostname` + nl)}
+		testFS["dir/file2"] = &fstest.MapFile{Data: []byte(ipStr + " hostname\n")}
 		eventsCh <- event{}
 
 		// Require the changes are written.
-		require.Eventually(t, func() bool {
-			ips := hc.MatchName("hostname")
+		current, ok = testutil.RequireReceive(t, hc.Upd(), 1*time.Second)
+		require.True(t, ok)
 
-			return len(ips) > 0
-		}, 5*time.Second, time.Second/2)
-
-		assert.Len(t, hc.Upd(), 1)
+		require.NotEmpty(t, current.ByName("hostname"))
 	})
 }
-
-func TestHostsContainer_MatchName(t *testing.T) {
-	require.NoError(t, fstest.TestFS(testdata, "etc_hosts"))
-
-	stubWatcher := aghtest.FSWatcher{
-		OnEvents: func() (e <-chan struct{}) { return nil },
-		OnAdd:    func(name string) (err error) { return nil },
-		OnClose:  func() (err error) { return nil },
-	}
-
-	testCases := []struct {
-		req  string
-		name string
-		want []*hostsfile.Record
-	}{{
-		req:  "simplehost",
-		name: "simple",
-		want: append(testHosts[addr1001], testHosts[addr1]...),
-	}, {
-		req:  "hello.world",
-		name: "hello_alias",
-		want: []*hostsfile.Record{
-			testHosts[addr1000][0],
-			testHosts[addr1000][2],
-			testHosts[addr0][0],
-			testHosts[addr0][2],
-		},
-	}, {
-		req:  "hello.world.again",
-		name: "other_line_alias",
-		want: []*hostsfile.Record{
-			testHosts[addr1000][1],
-			testHosts[addr0][1],
-		},
-	}, {
-		req:  "say.hello",
-		name: "hello_subdomain",
-		want: nil,
-	}, {
-		req:  "say.hello.world",
-		name: "hello_alias_subdomain",
-		want: nil,
-	}, {
-		req:  "for.testing",
-		name: "lots_of_aliases",
-		want: append(testHosts[addr1002], testHosts[addr2]...),
-	}, {
-		req:  "nonexistent.example",
-		name: "non-existing",
-		want: nil,
-	}, {
-		req:  "domain",
-		name: "issue_4216_4_6",
-		want: append(testHosts[addr4216], testHosts[addr42]...),
-	}, {
-		req:  "domain4",
-		name: "issue_4216_4",
-		want: append(testHosts[addr1357], testHosts[addr7531]...),
-	}, {
-		req:  "domain6",
-		name: "issue_4216_6",
-		want: append(testHosts[addr13], testHosts[addr31]...),
-	}}
-
-	hc, err := aghnet.NewHostsContainer(testdata, &stubWatcher, "etc_hosts")
-	require.NoError(t, err)
-	testutil.CleanupAndRequireSuccess(t, hc.Close)
-
-	for _, tc := range testCases {
-		t.Run(tc.name, func(t *testing.T) {
-			recs := hc.MatchName(tc.req)
-			assert.Equal(t, tc.want, recs)
-		})
-	}
-}
-
-func TestHostsContainer_MatchAddr(t *testing.T) {
-	require.NoError(t, fstest.TestFS(testdata, "etc_hosts"))
-
-	stubWatcher := aghtest.FSWatcher{
-		OnEvents: func() (e <-chan struct{}) { return nil },
-		OnAdd:    func(name string) (err error) { return nil },
-		OnClose:  func() (err error) { return nil },
-	}
-
-	hc, err := aghnet.NewHostsContainer(testdata, &stubWatcher, "etc_hosts")
-	require.NoError(t, err)
-	testutil.CleanupAndRequireSuccess(t, hc.Close)
-
-	testCases := []struct {
-		req  netip.Addr
-		name string
-		want []*hostsfile.Record
-	}{{
-		req:  netip.AddrFrom4([4]byte{1, 0, 0, 1}),
-		name: "reverse",
-		want: testHosts[addr1001],
-	}}
-
-	for _, tc := range testCases {
-		t.Run(tc.name, func(t *testing.T) {
-			recs := hc.MatchAddr(tc.req)
-			assert.Equal(t, tc.want, recs)
-		})
-	}
-}

internal/aghnet/hostscontainer_windows.go

@@ -1,32 +0,0 @@
-//go:build windows
-
-package aghnet
-
-import (
-	"os"
-	"path"
-	"path/filepath"
-	"strings"
-
-	"github.com/AdguardTeam/golibs/log"
-	"golang.org/x/sys/windows"
-)
-
-func defaultHostsPaths() (paths []string) {
-	sysDir, err := windows.GetSystemDirectory()
-	if err != nil {
-		log.Error("aghnet: getting system directory: %s", err)
-
-		return []string{}
-	}
-
-	// Split all the elements of the path to join them afterwards.  This is
-	// needed to make the Windows-specific path string returned by
-	// windows.GetSystemDirectory to be compatible with fs.FS.
-	pathElems := strings.Split(sysDir, string(os.PathSeparator))
-	if len(pathElems) > 0 && pathElems[0] == filepath.VolumeName(sysDir) {
-		pathElems = pathElems[1:]
-	}
-
-	return []string{path.Join(append(pathElems, "drivers/etc/hosts")...)}
-}

internal/aghnet/net_test.go

@@ -1,11 +1,9 @@
 package aghnet_test
 
 import (
-	"io/fs"
 	"net"
 	"net/netip"
 	"net/url"
-	"os"
 	"testing"
 
 	"github.com/AdguardTeam/AdGuardHome/internal/aghnet"
@@ -18,9 +16,6 @@ func TestMain(m *testing.M) {
 	testutil.DiscardLogOutput(m)
 }
 
-// testdata is the filesystem containing data for testing the package.
-var testdata fs.FS = os.DirFS("./testdata")
-
 func TestParseAddrPort(t *testing.T) {
 	const defaultPort = 1
 

internal/aghnet/testdata/etc_hosts

@@ -1,38 +0,0 @@
-#
-# Test /etc/hosts file
-#
-
-1.0.0.1 simplehost
-1.0.0.0 hello hello.world
-
-# See https://github.com/AdguardTeam/AdGuardHome/issues/3846.
-1.0.0.2 a.whole lot.of aliases for.testing
-
-# See https://github.com/AdguardTeam/AdGuardHome/issues/3946.
-1.0.0.3 *
-1.0.0.4 *.com
-
-# See https://github.com/AdguardTeam/AdGuardHome/issues/4079.
-1.0.0.0 hello.world.again
-
-# Duplicates of a main host and an alias.
-1.0.0.1 simplehost
-1.0.0.0 hello.world
-
-# Same for IPv6.
-::1 simplehost
-::  hello hello.world
-::2 a.whole lot.of aliases for.testing
-::3 *
-::4 *.com
-::  hello.world.again
-::1 simplehost
-::  hello.world
-
-# See https://github.com/AdguardTeam/AdGuardHome/issues/4216.
-4.2.1.6 domain domain.alias
-::42    domain.alias domain
-1.3.5.7 domain4 domain4.alias
-7.5.3.1 domain4.alias domain4
-::13    domain6 domain6.alias
-::31    domain6.alias domain6

internal/aghnet/testdata/ifaces

@@ -1 +0,0 @@
-iface sample_name inet static

internal/aghnet/testdata/include-subsources

@@ -1,5 +0,0 @@
-# The "testdata" part is added here because the test is actually run from the
-# parent directory.  Real interface files usually contain only absolute paths.
-
-source ./testdata/ifaces
-source ./testdata/*

internal/client/addrproc.go

@@ -262,8 +262,7 @@ func (p *DefaultAddrProc) processRDNS(ip netip.Addr) (host string) {
 // shouldResolve returns false if ip is a loopback address, or ip is private and
 // resolving of private addresses is disabled.
 func (p *DefaultAddrProc) shouldResolve(ip netip.Addr) (ok bool) {
-	return !ip.IsLoopback() &&
-		(p.usePrivateRDNS || !p.privateSubnets.Contains(ip.AsSlice()))
+	return !ip.IsLoopback() && (p.usePrivateRDNS || !p.privateSubnets.Contains(ip))
 }
 
 // processWHOIS looks up the information about clients' IP addresses in the

internal/client/client.go

@@ -7,6 +7,8 @@ package client
 import (
 	"encoding"
 	"fmt"
+
+	"github.com/AdguardTeam/AdGuardHome/internal/whois"
 )
 
 // Source represents the source from which the information about the client has
@@ -15,8 +17,7 @@ type Source uint8
 
 // Clients information sources.  The order determines the priority.
 const (
-	SourceNone Source = iota
-	SourceWHOIS
+	SourceWHOIS Source = iota + 1
 	SourceARP
 	SourceRDNS
 	SourceDHCP
@@ -52,3 +53,107 @@ var _ encoding.TextMarshaler = Source(0)
 func (cs Source) MarshalText() (text []byte, err error) {
 	return []byte(cs.String()), nil
 }
+
+// Runtime is a client information from different sources.
+type Runtime struct {
+	// whois is the filtered WHOIS information of a client.
+	whois *whois.Info
+
+	// arp is the ARP information of a client.  nil indicates that there is no
+	// information from the source.  Empty non-nil slice indicates that the data
+	// from the source is present, but empty.
+	arp []string
+
+	// rdns is the RDNS information of a client.  nil indicates that there is no
+	// information from the source.  Empty non-nil slice indicates that the data
+	// from the source is present, but empty.
+	rdns []string
+
+	// dhcp is the DHCP information of a client.  nil indicates that there is no
+	// information from the source.  Empty non-nil slice indicates that the data
+	// from the source is present, but empty.
+	dhcp []string
+
+	// hostsFile is the information from the hosts file.  nil indicates that
+	// there is no information from the source.  Empty non-nil slice indicates
+	// that the data from the source is present, but empty.
+	hostsFile []string
+}
+
+// Info returns a client information from the highest-priority source.
+func (r *Runtime) Info() (cs Source, host string) {
+	info := []string{}
+
+	switch {
+	case r.hostsFile != nil:
+		cs, info = SourceHostsFile, r.hostsFile
+	case r.dhcp != nil:
+		cs, info = SourceDHCP, r.dhcp
+	case r.rdns != nil:
+		cs, info = SourceRDNS, r.rdns
+	case r.arp != nil:
+		cs, info = SourceARP, r.arp
+	case r.whois != nil:
+		cs = SourceWHOIS
+	}
+
+	if len(info) == 0 {
+		return cs, ""
+	}
+
+	// TODO(s.chzhen):  Return the full information.
+	return cs, info[0]
+}
+
+// SetInfo sets a host as a client information from the cs.
+func (r *Runtime) SetInfo(cs Source, hosts []string) {
+	if len(hosts) == 1 && hosts[0] == "" {
+		hosts = []string{}
+	}
+
+	switch cs {
+	case SourceARP:
+		r.arp = hosts
+	case SourceRDNS:
+		r.rdns = hosts
+	case SourceDHCP:
+		r.dhcp = hosts
+	case SourceHostsFile:
+		r.hostsFile = hosts
+	}
+}
+
+// WHOIS returns a WHOIS client information.
+func (r *Runtime) WHOIS() (info *whois.Info) {
+	return r.whois
+}
+
+// SetWHOIS sets a WHOIS client information.  info must be non-nil.
+func (r *Runtime) SetWHOIS(info *whois.Info) {
+	r.whois = info
+}
+
+// Unset clears a cs information.
+func (r *Runtime) Unset(cs Source) {
+	switch cs {
+	case SourceWHOIS:
+		r.whois = nil
+	case SourceARP:
+		r.arp = nil
+	case SourceRDNS:
+		r.rdns = nil
+	case SourceDHCP:
+		r.dhcp = nil
+	case SourceHostsFile:
+		r.hostsFile = nil
+	}
+}
+
+// IsEmpty returns true if there is no information from any source.
+func (r *Runtime) IsEmpty() (ok bool) {
+	return r.whois == nil &&
+		r.arp == nil &&
+		r.rdns == nil &&
+		r.dhcp == nil &&
+		r.hostsFile == nil
+}

internal/configmigrate/configmigrate.go

@@ -0,0 +1,5 @@
+// Package configmigrate provides a way to upgrade the YAML configuration file.
+package configmigrate
+
+// LastSchemaVersion is the most recent schema version.
+const LastSchemaVersion uint = 28

internal/configmigrate/migrations_internal_test.go

@@ -1,9 +1,10 @@
-package confmigrate
+package configmigrate
 
 import (
 	"testing"
 	"time"
 
+	"github.com/AdguardTeam/AdGuardHome/internal/dnsforward"
 	"github.com/AdguardTeam/AdGuardHome/internal/filtering"
 	"github.com/AdguardTeam/golibs/testutil"
 	"github.com/AdguardTeam/golibs/timeutil"
@@ -1646,3 +1647,84 @@ func TestUpgradeSchema26to27(t *testing.T) {
 		})
 	}
 }
+
+func TestUpgradeSchema27to28(t *testing.T) {
+	const newSchemaVer = 28
+
+	testCases := []struct {
+		in   yobj
+		want yobj
+		name string
+	}{{
+		name: "empty",
+		in:   yobj{},
+		want: yobj{
+			"schema_version": newSchemaVer,
+		},
+	}, {
+		name: "load_balance",
+		in: yobj{
+			"dns": yobj{
+				"all_servers":  false,
+				"fastest_addr": false,
+			},
+		},
+		want: yobj{
+			"dns": yobj{
+				"upstream_mode": dnsforward.UpstreamModeLoadBalance,
+			},
+			"schema_version": newSchemaVer,
+		},
+	}, {
+		name: "parallel",
+		in: yobj{
+			"dns": yobj{
+				"all_servers":  true,
+				"fastest_addr": false,
+			},
+		},
+		want: yobj{
+			"dns": yobj{
+				"upstream_mode": dnsforward.UpstreamModeParallel,
+			},
+			"schema_version": newSchemaVer,
+		},
+	}, {
+		name: "parallel_fastest",
+		in: yobj{
+			"dns": yobj{
+				"all_servers":  true,
+				"fastest_addr": true,
+			},
+		},
+		want: yobj{
+			"dns": yobj{
+				"upstream_mode": dnsforward.UpstreamModeParallel,
+			},
+			"schema_version": newSchemaVer,
+		},
+	}, {
+		name: "load_balance",
+		in: yobj{
+			"dns": yobj{
+				"all_servers":  false,
+				"fastest_addr": true,
+			},
+		},
+		want: yobj{
+			"dns": yobj{
+				"upstream_mode": dnsforward.UpstreamModeFastestAddr,
+			},
+			"schema_version": newSchemaVer,
+		},
+	}}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			err := migrateTo28(tc.in)
+			require.NoError(t, err)
+
+			assert.Equal(t, tc.want, tc.in)
+		})
+	}
+}

internal/configmigrate/migrator.go

@@ -1,5 +1,4 @@
-// Package confmigrate provides a way to upgrade the YAML configuration file.
-package confmigrate
+package configmigrate
 
 import (
 	"bytes"
@@ -9,9 +8,6 @@ import (
 	yaml "gopkg.in/yaml.v3"
 )
 
-// LastSchemaVersion is the most recent schema version.
-const LastSchemaVersion uint = 27
-
 // Config is a the configuration for initializing a [Migrator].
 type Config struct {
 	// WorkingDir is an absolute path to the working directory of AdGuardHome.
@@ -123,6 +119,7 @@ func (m *Migrator) upgradeConfigSchema(current, target uint, diskConf yobj) (err
 		24: migrateTo25,
 		25: migrateTo26,
 		26: migrateTo27,
+		27: migrateTo28,
 	}
 
 	for i, migrate := range upgrades[current:target] {

internal/configmigrate/migrator_test.go

@@ -1,4 +1,4 @@
-package confmigrate_test
+package configmigrate_test
 
 import (
 	"io/fs"
@@ -6,7 +6,7 @@ import (
 	"path"
 	"testing"
 
-	"github.com/AdguardTeam/AdGuardHome/internal/confmigrate"
+	"github.com/AdguardTeam/AdGuardHome/internal/configmigrate"
 	"github.com/AdguardTeam/golibs/testutil"
 	"github.com/stretchr/testify/require"
 	"golang.org/x/crypto/bcrypt"
@@ -200,7 +200,7 @@ func TestMigrateConfig_Migrate(t *testing.T) {
 			wantBody, err := fs.ReadFile(testdata, path.Join(t.Name(), outputFileName))
 			require.NoError(t, err)
 
-			migrator := confmigrate.New(&confmigrate.Config{
+			migrator := configmigrate.New(&configmigrate.Config{
 				WorkingDir: t.Name(),
 			})
 			newBody, upgraded, err := migrator.Migrate(body, tc.targetVersion)

internal/configmigrate/v1.go

@@ -1,4 +1,4 @@
-package confmigrate
+package configmigrate
 
 import (
 	"os"

internal/configmigrate/v10.go

@@ -1,4 +1,4 @@
-package confmigrate
+package configmigrate
 
 import (
 	"fmt"

internal/configmigrate/v11.go

@@ -1,4 +1,4 @@
-package confmigrate
+package configmigrate
 
 // migrateTo11 performs the following changes:
 //

internal/configmigrate/v12.go

@@ -1,4 +1,4 @@
-package confmigrate
+package configmigrate
 
 import (
 	"time"

internal/configmigrate/v13.go

@@ -1,4 +1,4 @@
-package confmigrate
+package configmigrate
 
 // migrateTo13 performs the following changes:
 //

internal/configmigrate/v14.go

@@ -1,4 +1,4 @@
-package confmigrate
+package configmigrate
 
 // migrateTo14 performs the following changes:
 //

internal/configmigrate/v15.go

@@ -1,4 +1,4 @@
-package confmigrate
+package configmigrate
 
 // migrateTo15 performs the following changes:
 //

internal/configmigrate/v16.go

@@ -1,4 +1,4 @@
-package confmigrate
+package configmigrate
 
 // migrateTo16 performs the following changes:
 //

internal/configmigrate/v17.go

@@ -1,4 +1,4 @@
-package confmigrate
+package configmigrate
 
 // migrateTo17 performs the following changes:
 //

internal/configmigrate/v18.go

@@ -1,4 +1,4 @@
-package confmigrate
+package configmigrate
 
 // migrateTo18 performs the following changes:
 //

internal/configmigrate/v19.go

@@ -1,4 +1,4 @@
-package confmigrate
+package configmigrate
 
 import "github.com/AdguardTeam/golibs/log"
 

internal/configmigrate/v2.go

@@ -1,4 +1,4 @@
-package confmigrate
+package configmigrate
 
 import (
 	"os"

internal/configmigrate/v20.go

@@ -1,4 +1,4 @@
-package confmigrate
+package configmigrate
 
 import (
 	"time"

internal/configmigrate/v21.go

@@ -1,4 +1,4 @@
-package confmigrate
+package configmigrate
 
 // migrateTo21 performs the following changes:
 //

internal/configmigrate/v22.go

@@ -1,4 +1,4 @@
-package confmigrate
+package configmigrate
 
 import (
 	"fmt"

internal/configmigrate/v23.go

@@ -1,4 +1,4 @@
-package confmigrate
+package configmigrate
 
 import (
 	"fmt"

internal/configmigrate/v24.go

@@ -1,4 +1,4 @@
-package confmigrate
+package configmigrate
 
 // migrateTo24 performs the following changes:
 //

internal/configmigrate/v25.go

@@ -1,4 +1,4 @@
-package confmigrate
+package configmigrate
 
 // migrateTo25 performs the following changes:
 //

internal/configmigrate/v26.go

@@ -1,4 +1,4 @@
-package confmigrate
+package configmigrate
 
 // migrateTo26 performs the following changes:
 //

internal/configmigrate/v27.go

@@ -1,4 +1,4 @@
-package confmigrate
+package configmigrate
 
 // migrateTo27 performs the following changes:
 //

internal/configmigrate/v28.go

@@ -0,0 +1,47 @@
+package configmigrate
+
+import (
+	"github.com/AdguardTeam/AdGuardHome/internal/dnsforward"
+)
+
+// migrateTo28 performs the following changes:
+//
+//	# BEFORE:
+//	'dns':
+//	  'all_servers': true
+//	  'fastest_addr': true
+//	  # …
+//	# …
+//
+//	# AFTER:
+//	'dns':
+//	  'upstream_mode': 'parallel'
+//	  # …
+//	# …
+func migrateTo28(diskConf yobj) (err error) {
+	diskConf["schema_version"] = 28
+
+	dns, ok, err := fieldVal[yobj](diskConf, "dns")
+	if !ok {
+		return err
+	}
+
+	allServers, _, _ := fieldVal[bool](dns, "all_servers")
+	fastestAddr, _, _ := fieldVal[bool](dns, "fastest_addr")
+
+	var upstreamModeType dnsforward.UpstreamMode
+	if allServers {
+		upstreamModeType = dnsforward.UpstreamModeParallel
+	} else if fastestAddr {
+		upstreamModeType = dnsforward.UpstreamModeFastestAddr
+	} else {
+		upstreamModeType = dnsforward.UpstreamModeLoadBalance
+	}
+
+	dns["upstream_mode"] = upstreamModeType
+
+	delete(dns, "all_servers")
+	delete(dns, "fastest_addr")
+
+	return nil
+}

internal/configmigrate/v3.go

@@ -1,4 +1,4 @@
-package confmigrate
+package configmigrate
 
 // migrateTo3 performs the following changes:
 //

internal/configmigrate/v4.go

@@ -1,4 +1,4 @@
-package confmigrate
+package configmigrate
 
 // migrateTo4 performs the following changes:
 //

internal/configmigrate/v5.go

@@ -1,4 +1,4 @@
-package confmigrate
+package configmigrate
 
 import (
 	"fmt"

internal/configmigrate/v6.go

@@ -1,4 +1,4 @@
-package confmigrate
+package configmigrate
 
 import "fmt"
 

internal/configmigrate/v7.go

@@ -1,4 +1,4 @@
-package confmigrate
+package configmigrate
 
 // migrateTo7 performs the following changes:
 //

internal/configmigrate/v8.go

@@ -1,4 +1,4 @@
-package confmigrate
+package configmigrate
 
 // migrateTo8 performs the following changes:
 //

internal/configmigrate/v9.go

@@ -1,4 +1,4 @@
-package confmigrate
+package configmigrate
 
 // migrateTo9 performs the following changes:
 //