Pull request:* all: remove github.com/joomcode/errorx dependency

Merge in DNS/adguard-home from 2240-removing-errorx-dependency to master

Squashed commit of the following:

commit 5bbe0567356f06e3b9ee5b3dc38d357b472cacb1
Merge: a6040850d 02d16a0b4
Author: Eugene Burkov <e.burkov@adguard.com>
Date:   Thu Nov 5 14:32:22 2020 +0300

    Merge branch 'master' into 2240-removing-errorx-dependency

commit a6040850da3cefb131208097477b0956e80063fb
Author: Eugene Burkov <e.burkov@adguard.com>
Date:   Thu Nov 5 14:23:36 2020 +0300

    * dhcpd: convert some abbreviations to lowercase.

commit d05bd51b994906b0ff52c5a8e779bd1f512f4bb7
Author: Eugene Burkov <e.burkov@adguard.com>
Date:   Thu Nov 5 12:47:20 2020 +0300

    * agherr: last final fixes

commit 164bca55035ff44e50b0abb33e129a0d24ffe87c
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Tue Nov 3 19:11:10 2020 +0300

    * all: final fixes again

commit a0ac26f409c0b28a176cf2861d52c2f471b59484
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Tue Nov 3 18:51:39 2020 +0300

    * all: final fixes

commit 6147b02d402b513323b07e85856b348884f3a088
Merge: 9fd3af1a3 62cc334f4
Author: Eugene Burkov <e.burkov@adguard.com>
Date:   Tue Nov 3 18:26:03 2020 +0300

    Merge branch 'master' into 2240-removing-errorx-dependency

commit 9fd3af1a39a3189b5c41315a8ad1568ae5cb4fc9
Author: Eugene Burkov <e.burkov@adguard.com>
Date:   Tue Nov 3 18:23:08 2020 +0300

    * all: remove useless helper

commit 7cd9aeae639762b28b25f354d69c5cf74f670211
Author: Eugene Burkov <e.burkov@adguard.com>
Date:   Tue Nov 3 17:19:26 2020 +0300

    * agherr: improved code tidiness

commit a74a49236e9aaace070646dac710de9201105262
Merge: dc9dedbf2 df34ee5c0
Author: Eugene Burkov <e.burkov@adguard.com>
Date:   Tue Nov 3 16:54:29 2020 +0300

    Merge branch 'master' into 2240-removing-errorx-dependency

commit dc9dedbf205756e3adaa3bc776d349bf3d8c69a5
Author: Eugene Burkov <e.burkov@adguard.com>
Date:   Tue Nov 3 16:40:08 2020 +0300

    * agherr: improve and cover by tests

commit fd6bfe9e282156cc60e006cb7cd46cce4d3a07a8
Author: Eugene Burkov <e.burkov@adguard.com>
Date:   Tue Nov 3 14:06:27 2020 +0300

    * all: improve code quality

commit ea00c2f8c5060e9611f9a80cfd0e4a039526d0c4
Author: Eugene Burkov <e.burkov@adguard.com>
Date:   Tue Nov 3 13:03:57 2020 +0300

    * all: fix linter style warnings

commit 8e75e1a681a7218c2b4c69adfa2b7e1e2966f9ac
Author: Eugene Burkov <e.burkov@adguard.com>
Date:   Tue Nov 3 12:29:26 2020 +0300

    * all: remove github.com/joomcode/errorx dependency

    Closes #2240.

go.mod

@@ -12,7 +12,6 @@ require (
 	github.com/gobuffalo/packr v1.30.1
 	github.com/hugelgupf/socketpair v0.0.0-20190730060125-05d35a94e714
 	github.com/insomniacslk/dhcp v0.0.0-20200621044212-d74cd86ad5b8
-	github.com/joomcode/errorx v1.0.3
 	github.com/kardianos/service v1.1.0
 	github.com/mdlayher/ethernet v0.0.0-20190606142754-0394541c37b7
 	github.com/mdlayher/raw v0.0.0-20191009151244-50f2db8cc065

go.sum

@@ -136,8 +136,6 @@ github.com/joho/godotenv v1.3.0 h1:Zjp+RcGpHhGlrMbJzXTrZZPrWj+1vfm90La1wgB6Bhc=
 github.com/joho/godotenv v1.3.0/go.mod h1:7hK45KPybAkOC6peb+G5yklZfMxEjkZhHbwpqxOKXbg=
 github.com/joomcode/errorx v1.0.1 h1:CalpDWz14ZHd68fIqluJasJosAewpz2TFaJALrUxjrk=
 github.com/joomcode/errorx v1.0.1/go.mod h1:kgco15ekB6cs+4Xjzo7SPeXzx38PbJzBwbnu9qfVNHQ=
-github.com/joomcode/errorx v1.0.3 h1:3e1mi0u7/HTPNdg6d6DYyKGBhA5l9XpsfuVE29NxnWw=
-github.com/joomcode/errorx v1.0.3/go.mod h1:eQzdtdlNyN7etw6YCS4W4+lu442waxZYw5yvz0ULrRo=
 github.com/json-iterator/go v1.1.6/go.mod h1:+SdeFBvtyEkXs7REEP0seUULqWtbJapLOCVDaaPEHmU=
 github.com/jstemmer/go-junit-report v0.0.0-20190106144839-af01ea7f8024/go.mod h1:6v2b51hI/fHJwM22ozAgKL4VKDeJcHhJFhtBdhmNjmU=
 github.com/kardianos/service v1.1.0 h1:QV2SiEeWK42P0aEmGcsAgjApw/lRxkwopvT+Gu6t1/0=

internal/agherr/agherr.go

@@ -0,0 +1,59 @@
+// Package agherr contains the extended error type, and the function for
+// wrapping several errors.
+package agherr
+
+import (
+	"fmt"
+	"strings"
+)
+
+// manyError is an error containing several wrapped errors.  It is created to be
+// a simpler version of the API provided by github.com/joomcode/errorx.
+type manyError struct {
+	message    string
+	underlying []error
+}
+
+// Many wraps several errors and returns a single error.
+func Many(message string, underlying ...error) error {
+	err := &manyError{
+		message:    message,
+		underlying: underlying,
+	}
+
+	return err
+}
+
+// Error implements the error interface for *manyError.
+func (e *manyError) Error() string {
+	switch len(e.underlying) {
+	case 0:
+		return e.message
+	case 1:
+		return fmt.Sprintf("%s: %s", e.message, e.underlying[0])
+	default:
+		b := &strings.Builder{}
+
+		// Ignore errors, since strings.(*Buffer).Write never returns
+		// errors.
+		_, _ = fmt.Fprintf(b, "%s: %s (hidden: %s", e.message, e.underlying[0], e.underlying[1])
+		for _, u := range e.underlying[2:] {
+			// See comment above.
+			_, _ = fmt.Fprintf(b, ", %s", u)
+		}
+
+		// See comment above.
+		_, _ = b.WriteString(")")
+
+		return b.String()
+	}
+}
+
+// Unwrap implements the hidden errors.wrapper interface for *manyError.
+func (e *manyError) Unwrap() error {
+	if len(e.underlying) == 0 {
+		return nil
+	}
+
+	return e.underlying[0]
+}

internal/agherr/agherr_test.go

@@ -0,0 +1,73 @@
+package agherr
+
+import (
+	"errors"
+	"fmt"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestError_Error(t *testing.T) {
+	testCases := []struct {
+		name string
+		want string
+		err  error
+	}{{
+		name: "simple",
+		want: "a",
+		err:  Many("a"),
+	}, {
+		name: "wrapping",
+		want: "a: b",
+		err:  Many("a", errors.New("b")),
+	}, {
+		name: "wrapping several",
+		want: "a: b (hidden: c, d)",
+		err:  Many("a", errors.New("b"), errors.New("c"), errors.New("d")),
+	}, {
+		name: "wrapping wrapper",
+		want: "a: b: c (hidden: d)",
+		err:  Many("a", Many("b", errors.New("c"), errors.New("d"))),
+	}}
+	for _, tc := range testCases {
+		assert.Equal(t, tc.want, tc.err.Error(), tc.name)
+	}
+}
+
+func TestError_Unwrap(t *testing.T) {
+	const (
+		errSimple = iota
+		errWrapped
+		errNil
+	)
+	errs := []error{
+		errSimple:  errors.New("a"),
+		errWrapped: fmt.Errorf("%w", errors.New("nested")),
+		errNil:     nil,
+	}
+	testCases := []struct {
+		name    string
+		want    error
+		wrapped error
+	}{{
+		name:    "simple",
+		want:    errs[errSimple],
+		wrapped: Many("a", errs[errSimple]),
+	}, {
+		name:    "nested",
+		want:    errs[errWrapped],
+		wrapped: Many("b", errs[errWrapped]),
+	}, {
+		name:    "nil passed",
+		want:    errs[errNil],
+		wrapped: Many("c", errs[errNil]),
+	}, {
+		name:    "nil not passed",
+		want:    nil,
+		wrapped: Many("d"),
+	}}
+	for _, tc := range testCases {
+		assert.Equal(t, tc.want, errors.Unwrap(tc.wrapped), tc.name)
+	}
+}

internal/dhcpd/check_other_dhcp.go

@@ -23,7 +23,7 @@ import (
 func CheckIfOtherDHCPServersPresentV4(ifaceName string) (bool, error) {
 	iface, err := net.InterfaceByName(ifaceName)
 	if err != nil {
-		return false, wrapErrPrint(err, "Couldn't find interface by name %s", ifaceName)
+		return false, fmt.Errorf("couldn't find interface by name %s: %w", ifaceName, err)
 	}
 
 	// get ipv4 address of an interface
@@ -44,7 +44,7 @@ func CheckIfOtherDHCPServersPresentV4(ifaceName string) (bool, error) {
 
 	req, err := dhcpv4.NewDiscovery(iface.HardwareAddr)
 	if err != nil {
-		return false, fmt.Errorf("dhcpv4.NewDiscovery: %s", err)
+		return false, fmt.Errorf("dhcpv4.NewDiscovery: %w", err)
 	}
 	req.Options.Update(dhcpv4.OptClientIdentifier(iface.HardwareAddr))
 	req.Options.Update(dhcpv4.OptHostName(hostname))
@@ -52,24 +52,24 @@ func CheckIfOtherDHCPServersPresentV4(ifaceName string) (bool, error) {
 	// resolve 0.0.0.0:68
 	udpAddr, err := net.ResolveUDPAddr("udp4", src)
 	if err != nil {
-		return false, wrapErrPrint(err, "Couldn't resolve UDP address %s", src)
+		return false, fmt.Errorf("couldn't resolve UDP address %s: %w", src, err)
 	}
 
 	if !udpAddr.IP.To4().Equal(srcIP) {
-		return false, wrapErrPrint(err, "Resolved UDP address is not %s", src)
+		return false, fmt.Errorf("resolved UDP address is not %s: %w", src, err)
 	}
 
 	// resolve 255.255.255.255:67
 	dstAddr, err := net.ResolveUDPAddr("udp4", dst)
 	if err != nil {
-		return false, wrapErrPrint(err, "Couldn't resolve UDP address %s", dst)
+		return false, fmt.Errorf("couldn't resolve UDP address %s: %w", dst, err)
 	}
 
 	// bind to 0.0.0.0:68
 	log.Tracef("Listening to udp4 %+v", udpAddr)
 	c, err := nclient4.NewRawUDPConn(ifaceName, 68)
 	if err != nil {
-		return false, wrapErrPrint(err, "Couldn't listen on :68")
+		return false, fmt.Errorf("couldn't listen on :68: %w", err)
 	}
 	if c != nil {
 		defer c.Close()
@@ -78,7 +78,7 @@ func CheckIfOtherDHCPServersPresentV4(ifaceName string) (bool, error) {
 	// send to 255.255.255.255:67
 	_, err = c.WriteTo(req.ToBytes(), dstAddr)
 	if err != nil {
-		return false, wrapErrPrint(err, "Couldn't send a packet to %s", dst)
+		return false, fmt.Errorf("couldn't send a packet to %s: %w", dst, err)
 	}
 
 	for {
@@ -94,7 +94,7 @@ func CheckIfOtherDHCPServersPresentV4(ifaceName string) (bool, error) {
 			return false, nil
 		}
 		if err != nil {
-			return false, wrapErrPrint(err, "Couldn't receive packet")
+			return false, fmt.Errorf("couldn't receive packet: %w", err)
 		}
 
 		log.Tracef("Received packet (%v bytes)", n)
@@ -127,12 +127,12 @@ func CheckIfOtherDHCPServersPresentV4(ifaceName string) (bool, error) {
 func CheckIfOtherDHCPServersPresentV6(ifaceName string) (bool, error) {
 	iface, err := net.InterfaceByName(ifaceName)
 	if err != nil {
-		return false, fmt.Errorf("DHCPv6: net.InterfaceByName: %s: %s", ifaceName, err)
+		return false, fmt.Errorf("dhcpv6: net.InterfaceByName: %s: %w", ifaceName, err)
 	}
 
 	ifaceIPNet := getIfaceIPv6(*iface)
 	if len(ifaceIPNet) == 0 {
-		return false, fmt.Errorf("DHCPv6: couldn't find IPv6 address of interface %s %+v", ifaceName, iface)
+		return false, fmt.Errorf("dhcpv6: couldn't find IPv6 address of interface %s %+v", ifaceName, iface)
 	}
 
 	srcIP := ifaceIPNet[0]
@@ -141,27 +141,27 @@ func CheckIfOtherDHCPServersPresentV6(ifaceName string) (bool, error) {
 
 	req, err := dhcpv6.NewSolicit(iface.HardwareAddr)
 	if err != nil {
-		return false, fmt.Errorf("DHCPv6: dhcpv6.NewSolicit: %s", err)
+		return false, fmt.Errorf("dhcpv6: dhcpv6.NewSolicit: %w", err)
 	}
 
 	udpAddr, err := net.ResolveUDPAddr("udp6", src)
 	if err != nil {
-		return false, wrapErrPrint(err, "DHCPv6: Couldn't resolve UDP address %s", src)
+		return false, fmt.Errorf("dhcpv6: Couldn't resolve UDP address %s: %w", src, err)
 	}
 
 	if !udpAddr.IP.To16().Equal(srcIP) {
-		return false, wrapErrPrint(err, "DHCPv6: Resolved UDP address is not %s", src)
+		return false, fmt.Errorf("dhcpv6: Resolved UDP address is not %s: %w", src, err)
 	}
 
 	dstAddr, err := net.ResolveUDPAddr("udp6", dst)
 	if err != nil {
-		return false, fmt.Errorf("DHCPv6: Couldn't resolve UDP address %s: %s", dst, err)
+		return false, fmt.Errorf("dhcpv6: Couldn't resolve UDP address %s: %w", dst, err)
 	}
 
 	log.Debug("DHCPv6: Listening to udp6 %+v", udpAddr)
 	c, err := nclient6.NewIPv6UDPConn(ifaceName, dhcpv6.DefaultClientPort)
 	if err != nil {
-		return false, fmt.Errorf("DHCPv6: Couldn't listen on :546: %s", err)
+		return false, fmt.Errorf("dhcpv6: Couldn't listen on :546: %w", err)
 	}
 	if c != nil {
 		defer c.Close()
@@ -169,7 +169,7 @@ func CheckIfOtherDHCPServersPresentV6(ifaceName string) (bool, error) {
 
 	_, err = c.WriteTo(req.ToBytes(), dstAddr)
 	if err != nil {
-		return false, fmt.Errorf("DHCPv6: Couldn't send a packet to %s: %s", dst, err)
+		return false, fmt.Errorf("dhcpv6: Couldn't send a packet to %s: %w", dst, err)
 	}
 
 	for {
@@ -182,7 +182,7 @@ func CheckIfOtherDHCPServersPresentV6(ifaceName string) (bool, error) {
 			return false, nil
 		}
 		if err != nil {
-			return false, wrapErrPrint(err, "Couldn't receive packet")
+			return false, fmt.Errorf("couldn't receive packet: %w", err)
 		}
 
 		log.Debug("DHCPv6: Received packet (%v bytes)", n)

internal/dhcpd/helpers.go

@@ -4,9 +4,6 @@ import (
 	"encoding/binary"
 	"fmt"
 	"net"
-
-	"github.com/AdguardTeam/golibs/log"
-	"github.com/joomcode/errorx"
 )
 
 func isTimeout(err error) bool {
@@ -37,17 +34,6 @@ func getIfaceIPv4(iface net.Interface) []net.IP {
 	return res
 }
 
-func wrapErrPrint(err error, message string, args ...interface{}) error {
-	var errx error
-	if err == nil {
-		errx = fmt.Errorf(message, args...)
-	} else {
-		errx = errorx.Decorate(err, message, args...)
-	}
-	log.Println(errx.Error())
-	return errx
-}
-
 func parseIPv4(text string) (net.IP, error) {
 	result := net.ParseIP(text)
 	if result == nil {

internal/dhcpd/router_adv.go

@@ -163,7 +163,7 @@ func (ra *raCtx) Init() error {
 		return nil
 	}
 
-	log.Debug("DHCPv6 RA: source IP address: %s  DNS IP address: %s",
+	log.Debug("dhcpv6 ra: source IP address: %s  DNS IP address: %s",
 		ra.ipAddr, ra.dnsIPAddr)
 
 	params := icmpv6RA{
@@ -183,7 +183,7 @@ func (ra *raCtx) Init() error {
 	ipAndScope := ra.ipAddr.String() + "%" + ra.ifaceName
 	ra.conn, err = icmp.ListenPacket("ip6:ipv6-icmp", ipAndScope)
 	if err != nil {
-		return fmt.Errorf("DHCPv6 RA: icmp.ListenPacket: %s", err)
+		return fmt.Errorf("dhcpv6 ra: icmp.ListenPacket: %w", err)
 	}
 	success := false
 	defer func() {
@@ -195,11 +195,11 @@ func (ra *raCtx) Init() error {
 	con6 := ra.conn.IPv6PacketConn()
 
 	if err := con6.SetHopLimit(255); err != nil {
-		return fmt.Errorf("DHCPv6 RA: SetHopLimit: %s", err)
+		return fmt.Errorf("dhcpv6 ra: SetHopLimit: %w", err)
 	}
 
 	if err := con6.SetMulticastHopLimit(255); err != nil {
-		return fmt.Errorf("DHCPv6 RA: SetMulticastHopLimit: %s", err)
+		return fmt.Errorf("dhcpv6 ra: SetMulticastHopLimit: %w", err)
 	}
 
 	msg := &ipv6.ControlMessage{
@@ -212,15 +212,15 @@ func (ra *raCtx) Init() error {
 	}
 
 	go func() {
-		log.Debug("DHCPv6 RA: starting to send periodic RouterAdvertisement packets")
+		log.Debug("dhcpv6 ra: starting to send periodic RouterAdvertisement packets")
 		for ra.stop.Load() == 0 {
 			_, err = con6.WriteTo(data, msg, addr)
 			if err != nil {
-				log.Error("DHCPv6 RA: WriteTo: %s", err)
+				log.Error("dhcpv6 ra: WriteTo: %s", err)
 			}
 			time.Sleep(ra.packetSendPeriod)
 		}
-		log.Debug("DHCPv6 RA: loop exit")
+		log.Debug("dhcpv6 ra: loop exit")
 	}()
 
 	success = true
@@ -229,7 +229,7 @@ func (ra *raCtx) Init() error {
 
 // Close - close module
 func (ra *raCtx) Close() {
-	log.Debug("DHCPv6 RA: closing")
+	log.Debug("dhcpv6 ra: closing")
 
 	ra.stop.Store(1)
 

internal/dhcpd/v4.go

@@ -55,7 +55,7 @@ func (s *v4Server) ResetLeases(leases []*Lease) {
 		if l.Expiry.Unix() != leaseExpireStatic &&
 			!ip4InRange(s.conf.ipStart, s.conf.ipEnd, l.IP) {
 
-			log.Debug("DHCPv4: skipping a lease with IP %v: not within current IP range", l.IP)
+			log.Debug("dhcpv4: skipping a lease with IP %v: not within current IP range", l.IP)
 			continue
 		}
 
@@ -124,7 +124,7 @@ func (s *v4Server) blacklistLease(lease *Lease) {
 // Remove (swap) lease by index
 func (s *v4Server) leaseRemoveSwapByIndex(i int) {
 	s.ipAddrs[s.leases[i].IP[3]] = 0
-	log.Debug("DHCPv4: removed lease %s", s.leases[i].HWAddr)
+	log.Debug("dhcpv4: removed lease %s", s.leases[i].HWAddr)
 
 	n := len(s.leases)
 	if i != n-1 {
@@ -168,7 +168,7 @@ func (s *v4Server) rmDynamicLease(lease Lease) error {
 func (s *v4Server) addLease(l *Lease) {
 	s.leases = append(s.leases, l)
 	s.ipAddrs[l.IP[3]] = 1
-	log.Debug("DHCPv4: added lease %s <-> %s", l.IP, l.HWAddr)
+	log.Debug("dhcpv4: added lease %s <-> %s", l.IP, l.HWAddr)
 }
 
 // Remove a lease with the same properties
@@ -178,8 +178,7 @@ func (s *v4Server) rmLease(lease Lease) error {
 
 			if !bytes.Equal(l.HWAddr, lease.HWAddr) ||
 				l.Hostname != lease.Hostname {
-
+				return fmt.Errorf("lease not found")
-				return fmt.Errorf("Lease not found")
 			}
 
 			s.leaseRemoveSwapByIndex(i)
@@ -238,7 +237,6 @@ func (s *v4Server) RemoveStaticLease(l Lease) error {
 // Send ICMP to the specified machine
 // Return TRUE if it doesn't reply, which probably means that the IP is available
 func (s *v4Server) addrAvailable(target net.IP) bool {
-
 	if s.conf.ICMPTimeout == 0 {
 		return true
 	}
@@ -256,15 +254,15 @@ func (s *v4Server) addrAvailable(target net.IP) bool {
 	pinger.OnRecv = func(pkt *ping.Packet) {
 		reply = true
 	}
-	log.Debug("DHCPv4: Sending ICMP Echo to %v", target)
+	log.Debug("dhcpv4: Sending ICMP Echo to %v", target)
 	pinger.Run()
 
 	if reply {
-		log.Info("DHCPv4: IP conflict: %v is already used by another device", target)
+		log.Info("dhcpv4: IP conflict: %v is already used by another device", target)
 		return false
 	}
 
-	log.Debug("DHCPv4: ICMP procedure is complete: %v", target)
+	log.Debug("dhcpv4: ICMP procedure is complete: %v", target)
 	return true
 }
 
@@ -349,7 +347,7 @@ func (s *v4Server) processDiscover(req *dhcpv4.DHCPv4, resp *dhcpv4.DHCPv4) *Lea
 		for lease == nil {
 			lease = s.reserveLease(mac)
 			if lease == nil {
-				log.Debug("DHCPv4: No more IP addresses")
+				log.Debug("dhcpv4: No more IP addresses")
 				if toStore {
 					s.conf.notify(LeaseChangedDBStore)
 				}
@@ -372,7 +370,7 @@ func (s *v4Server) processDiscover(req *dhcpv4.DHCPv4, resp *dhcpv4.DHCPv4) *Lea
 		reqIP := req.Options.Get(dhcpv4.OptionRequestedIPAddress)
 		if len(reqIP) != 0 &&
 			!bytes.Equal(reqIP, lease.IP) {
-			log.Debug("DHCPv4: different RequestedIP: %v != %v", reqIP, lease.IP)
+			log.Debug("dhcpv4: different RequestedIP: %v != %v", reqIP, lease.IP)
 		}
 	}
 
@@ -407,7 +405,6 @@ func (o *optFQDN) ToBytes() []byte {
 
 	copy(b[i:], []byte(o.name))
 	return b
-
 }
 
 // Process Request request and return lease
@@ -424,12 +421,12 @@ func (s *v4Server) processRequest(req *dhcpv4.DHCPv4, resp *dhcpv4.DHCPv4) (*Lea
 	sid := req.Options.Get(dhcpv4.OptionServerIdentifier)
 	if len(sid) != 0 &&
 		!bytes.Equal(sid, s.conf.dnsIPAddrs[0]) {
-		log.Debug("DHCPv4: Bad OptionServerIdentifier in Request message for %s", mac)
+		log.Debug("dhcpv4: Bad OptionServerIdentifier in Request message for %s", mac)
 		return nil, false
 	}
 
 	if len(reqIP) != 4 {
-		log.Debug("DHCPv4: Bad OptionRequestedIPAddress in Request message for %s", mac)
+		log.Debug("dhcpv4: Bad OptionRequestedIPAddress in Request message for %s", mac)
 		return nil, false
 	}
 
@@ -438,7 +435,7 @@ func (s *v4Server) processRequest(req *dhcpv4.DHCPv4, resp *dhcpv4.DHCPv4) (*Lea
 		if bytes.Equal(l.HWAddr, mac) {
 			if !bytes.Equal(l.IP, reqIP) {
 				s.leasesLock.Unlock()
-				log.Debug("DHCPv4: Mismatched OptionRequestedIPAddress in Request message for %s", mac)
+				log.Debug("dhcpv4: Mismatched OptionRequestedIPAddress in Request message for %s", mac)
 				return nil, true
 			}
 
@@ -449,7 +446,7 @@ func (s *v4Server) processRequest(req *dhcpv4.DHCPv4, resp *dhcpv4.DHCPv4) (*Lea
 	s.leasesLock.Unlock()
 
 	if lease == nil {
-		log.Debug("DHCPv4: No lease for %s", mac)
+		log.Debug("dhcpv4: No lease for %s", mac)
 		return nil, true
 	}
 
@@ -476,7 +473,6 @@ func (s *v4Server) processRequest(req *dhcpv4.DHCPv4, resp *dhcpv4.DHCPv4) (*Lea
 // Return 0: error; reply with Nak
 // Return -1: error; don't reply
 func (s *v4Server) process(req *dhcpv4.DHCPv4, resp *dhcpv4.DHCPv4) int {
-
 	var lease *Lease
 
 	resp.UpdateOption(dhcpv4.OptServerIdentifier(s.conf.dnsIPAddrs[0]))
@@ -519,7 +515,7 @@ func (s *v4Server) process(req *dhcpv4.DHCPv4, resp *dhcpv4.DHCPv4) int {
 // client(0.0.0.0:68) -> (Request:ClientMAC,Type=Request,ClientID,ReqIP||ClientIP,HostName,ServerID,ParamReqList) -> server(255.255.255.255:67)
 // client(255.255.255.255:68) <- (Reply:YourIP,ClientMAC,Type=ACK,ServerID,SubnetMask,LeaseTime) <- server(<IP>:67)
 func (s *v4Server) packetHandler(conn net.PacketConn, peer net.Addr, req *dhcpv4.DHCPv4) {
-	log.Debug("DHCPv4: received message: %s", req.Summary())
+	log.Debug("dhcpv4: received message: %s", req.Summary())
 
 	switch req.MessageType() {
 	case dhcpv4.MessageTypeDiscover,
@@ -527,18 +523,18 @@ func (s *v4Server) packetHandler(conn net.PacketConn, peer net.Addr, req *dhcpv4
 		//
 
 	default:
-		log.Debug("DHCPv4: unsupported message type %d", req.MessageType())
+		log.Debug("dhcpv4: unsupported message type %d", req.MessageType())
 		return
 	}
 
 	resp, err := dhcpv4.NewReplyFromRequest(req)
 	if err != nil {
-		log.Debug("DHCPv4: dhcpv4.New: %s", err)
+		log.Debug("dhcpv4: dhcpv4.New: %s", err)
 		return
 	}
 
 	if len(req.ClientHWAddr) != 6 {
-		log.Debug("DHCPv4: Invalid ClientHWAddr")
+		log.Debug("dhcpv4: Invalid ClientHWAddr")
 		return
 	}
 
@@ -549,11 +545,11 @@ func (s *v4Server) packetHandler(conn net.PacketConn, peer net.Addr, req *dhcpv4
 		resp.Options.Update(dhcpv4.OptMessageType(dhcpv4.MessageTypeNak))
 	}
 
-	log.Debug("DHCPv4: sending: %s", resp.Summary())
+	log.Debug("dhcpv4: sending: %s", resp.Summary())
 
 	_, err = conn.WriteTo(resp.ToBytes(), peer)
 	if err != nil {
-		log.Error("DHCPv4: conn.Write to %s failed: %s", peer, err)
+		log.Error("dhcpv4: conn.Write to %s failed: %s", peer, err)
 		return
 	}
 }
@@ -566,13 +562,13 @@ func (s *v4Server) Start() error {
 
 	iface, err := net.InterfaceByName(s.conf.InterfaceName)
 	if err != nil {
-		return fmt.Errorf("DHCPv4: Couldn't find interface by name %s: %s", s.conf.InterfaceName, err)
+		return fmt.Errorf("dhcpv4: Couldn't find interface by name %s: %w", s.conf.InterfaceName, err)
 	}
 
-	log.Debug("DHCPv4: starting...")
+	log.Debug("dhcpv4: starting...")
 	s.conf.dnsIPAddrs = getIfaceIPv4(*iface)
 	if len(s.conf.dnsIPAddrs) == 0 {
-		log.Debug("DHCPv4: no IPv6 address for interface %s", iface.Name)
+		log.Debug("dhcpv4: no IPv6 address for interface %s", iface.Name)
 		return nil
 	}
 
@@ -585,11 +581,11 @@ func (s *v4Server) Start() error {
 		return err
 	}
 
-	log.Info("DHCPv4: listening")
+	log.Info("dhcpv4: listening")
 
 	go func() {
 		err = s.srv.Serve()
-		log.Debug("DHCPv4: srv.Serve: %s", err)
+		log.Debug("dhcpv4: srv.Serve: %s", err)
 	}()
 	return nil
 }
@@ -600,10 +596,10 @@ func (s *v4Server) Stop() {
 		return
 	}
 
-	log.Debug("DHCPv4: stopping")
+	log.Debug("dhcpv4: stopping")
 	err := s.srv.Close()
 	if err != nil {
-		log.Error("DHCPv4: srv.Close: %s", err)
+		log.Error("dhcpv4: srv.Close: %s", err)
 	}
 	// now s.srv.Serve() will return
 	s.srv = nil
@@ -621,31 +617,31 @@ func v4Create(conf V4ServerConf) (DHCPServer, error) {
 	var err error
 	s.conf.routerIP, err = parseIPv4(s.conf.GatewayIP)
 	if err != nil {
-		return s, fmt.Errorf("DHCPv4: %s", err)
+		return s, fmt.Errorf("dhcpv4: %w", err)
 	}
 
 	subnet, err := parseIPv4(s.conf.SubnetMask)
 	if err != nil || !isValidSubnetMask(subnet) {
-		return s, fmt.Errorf("DHCPv4: invalid subnet mask: %s", s.conf.SubnetMask)
+		return s, fmt.Errorf("dhcpv4: invalid subnet mask: %s", s.conf.SubnetMask)
 	}
 	s.conf.subnetMask = make([]byte, 4)
 	copy(s.conf.subnetMask, subnet)
 
 	s.conf.ipStart, err = parseIPv4(conf.RangeStart)
 	if s.conf.ipStart == nil {
-		return s, fmt.Errorf("DHCPv4: %s", err)
+		return s, fmt.Errorf("dhcpv4: %w", err)
 	}
 	if s.conf.ipStart[0] == 0 {
-		return s, fmt.Errorf("DHCPv4: invalid range start IP")
+		return s, fmt.Errorf("dhcpv4: invalid range start IP")
 	}
 
 	s.conf.ipEnd, err = parseIPv4(conf.RangeEnd)
 	if s.conf.ipEnd == nil {
-		return s, fmt.Errorf("DHCPv4: %s", err)
+		return s, fmt.Errorf("dhcpv4: %w", err)
 	}
 	if !net.IP.Equal(s.conf.ipStart[:3], s.conf.ipEnd[:3]) ||
 		s.conf.ipStart[3] > s.conf.ipEnd[3] {
-		return s, fmt.Errorf("DHCPv4: range end IP should match range start IP")
+		return s, fmt.Errorf("dhcpv4: range end IP should match range start IP")
 	}
 
 	if conf.LeaseDuration == 0 {
@@ -658,7 +654,7 @@ func v4Create(conf V4ServerConf) (DHCPServer, error) {
 	for _, o := range conf.Options {
 		code, val := parseOptionString(o)
 		if code == 0 {
-			log.Debug("DHCPv4: bad option string: %s", o)
+			log.Debug("dhcpv4: bad option string: %s", o)
 			continue
 		}
 

internal/dhcpd/v6.go

@@ -73,12 +73,10 @@ func (s *v6Server) GetLeases(flags int) []Lease {
 	var result []Lease
 	s.leasesLock.Lock()
 	for _, lease := range s.leases {
-
 		if lease.Expiry.Unix() == leaseExpireStatic {
 			if (flags & LeasesStatic) != 0 {
 				result = append(result, *lease)
 			}
-
 		} else {
 			if (flags & LeasesDynamic) != 0 {
 				result = append(result, *lease)
@@ -215,8 +213,7 @@ func (s *v6Server) rmLease(lease Lease) error {
 
 			if !bytes.Equal(l.HWAddr, lease.HWAddr) ||
 				l.Hostname != lease.Hostname {
-
+				return fmt.Errorf("lease not found")
-				return fmt.Errorf("Lease not found")
 			}
 
 			s.leaseRemoveSwapByIndex(i)
@@ -303,7 +300,7 @@ func (s *v6Server) commitDynamicLease(l *Lease) {
 // Check Client ID
 func (s *v6Server) checkCID(msg *dhcpv6.Message) error {
 	if msg.Options.ClientID() == nil {
-		return fmt.Errorf("DHCPv6: no ClientID option in request")
+		return fmt.Errorf("dhcpv6: no ClientID option in request")
 	}
 	return nil
 }
@@ -318,7 +315,7 @@ func (s *v6Server) checkSID(msg *dhcpv6.Message) error {
 		dhcpv6.MessageTypeRebind:
 
 		if sid != nil {
-			return fmt.Errorf("DHCPv6: drop packet: ServerID option in message %s", msg.Type().String())
+			return fmt.Errorf("dhcpv6: drop packet: ServerID option in message %s", msg.Type().String())
 		}
 
 	case dhcpv6.MessageTypeRequest,
@@ -327,10 +324,10 @@ func (s *v6Server) checkSID(msg *dhcpv6.Message) error {
 		dhcpv6.MessageTypeDecline:
 
 		if sid == nil {
-			return fmt.Errorf("DHCPv6: drop packet: no ServerID option in message %s", msg.Type().String())
+			return fmt.Errorf("dhcpv6: drop packet: no ServerID option in message %s", msg.Type().String())
 		}
 		if !sid.Equal(s.sid) {
-			return fmt.Errorf("DHCPv6: drop packet: mismatched ServerID option in message %s: %s",
+			return fmt.Errorf("dhcpv6: drop packet: mismatched ServerID option in message %s: %s",
 				msg.Type().String(), sid.String())
 		}
 	}
@@ -589,7 +586,7 @@ func (s *v6Server) Start() error {
 
 	iface, err := net.InterfaceByName(s.conf.InterfaceName)
 	if err != nil {
-		return wrapErrPrint(err, "Couldn't find interface by name %s", s.conf.InterfaceName)
+		return fmt.Errorf("couldn't find interface by name %s: %w", s.conf.InterfaceName, err)
 	}
 
 	s.conf.dnsIPAddrs = getIfaceIPv6(*iface)
@@ -612,7 +609,7 @@ func (s *v6Server) Start() error {
 	log.Debug("DHCPv6: starting...")
 
 	if len(iface.HardwareAddr) != 6 {
-		return fmt.Errorf("DHCPv6: invalid MAC %s", iface.HardwareAddr)
+		return fmt.Errorf("dhcpv6: invalid MAC %s", iface.HardwareAddr)
 	}
 	s.sid = dhcpv6.Duid{
 		Type:          dhcpv6.DUID_LLT,
@@ -667,7 +664,7 @@ func v6Create(conf V6ServerConf) (DHCPServer, error) {
 
 	s.conf.ipStart = net.ParseIP(conf.RangeStart)
 	if s.conf.ipStart == nil || s.conf.ipStart.To16() == nil {
-		return s, fmt.Errorf("DHCPv6: invalid range-start IP: %s", conf.RangeStart)
+		return s, fmt.Errorf("dhcpv6: invalid range-start IP: %s", conf.RangeStart)
 	}
 
 	if conf.LeaseDuration == 0 {

internal/dnsfilter/README.md

@@ -22,12 +22,12 @@ func main() {
     res, err := filter.CheckHost(host)
     if err != nil {
         // temporary failure
-        log.Fatalf("Failed to check host '%s': %s", host, err)
+        log.Fatalf("Failed to check host %q: %s", host, err)
     }
     if res.IsFiltered {
-        log.Printf("Host %s is filtered, reason - '%s', matched rule: '%s'", host, res.Reason, res.Rule)
+        log.Printf("Host %s is filtered, reason - %q, matched rule: %q", host, res.Reason, res.Rule)
     } else {
-        log.Printf("Host %s is not filtered, reason - '%s'", host, res.Reason)
+        log.Printf("Host %s is not filtered, reason - %q", host, res.Reason)
     }
 }
 ```
@@ -59,12 +59,12 @@ func main() {
     res, err := filter.CheckHost(host)
     if err != nil {
         // temporary failure
-        log.Fatalf("Failed to check host '%s': %s", host, err)
+        log.Fatalf("Failed to check host %q: %s", host, err)
     }
     if res.IsFiltered {
-        log.Printf("Host %s is filtered, reason - '%s', matched rule: '%s'", host, res.Reason, res.Rule)
+        log.Printf("Host %s is filtered, reason - %q, matched rule: %q", host, res.Reason, res.Rule)
     } else {
-        log.Printf("Host %s is not filtered, reason - '%s'", host, res.Reason)
+        log.Printf("Host %s is not filtered, reason - %q", host, res.Reason)
     }
 }
 ```

internal/dnsfilter/dnsfilter.go

@@ -501,19 +501,17 @@ func createFilteringEngine(filters []Filter) (*filterlist.RuleStorage, *urlfilte
 				RulesText:      string(f.Data),
 				IgnoreCosmetic: true,
 			}
-
 		} else if !fileExists(f.FilePath) {
 			list = &filterlist.StringRuleList{
 				ID:             int(f.ID),
 				IgnoreCosmetic: true,
 			}
-
 		} else if runtime.GOOS == "windows" {
 			// On Windows we don't pass a file to urlfilter because
 			//  it's difficult to update this file while it's being used.
 			data, err := ioutil.ReadFile(f.FilePath)
 			if err != nil {
-				return nil, nil, fmt.Errorf("ioutil.ReadFile(): %s: %s", f.FilePath, err)
+				return nil, nil, fmt.Errorf("ioutil.ReadFile(): %s: %w", f.FilePath, err)
 			}
 			list = &filterlist.StringRuleList{
 				ID:             int(f.ID),
@@ -525,7 +523,7 @@ func createFilteringEngine(filters []Filter) (*filterlist.RuleStorage, *urlfilte
 			var err error
 			list, err = filterlist.NewFileRuleList(int(f.ID), f.FilePath, true)
 			if err != nil {
-				return nil, nil, fmt.Errorf("filterlist.NewFileRuleList(): %s: %s", f.FilePath, err)
+				return nil, nil, fmt.Errorf("filterlist.NewFileRuleList(): %s: %w", f.FilePath, err)
 			}
 		}
 		listArray = append(listArray, list)
@@ -533,7 +531,7 @@ func createFilteringEngine(filters []Filter) (*filterlist.RuleStorage, *urlfilte
 
 	rulesStorage, err := filterlist.NewRuleStorage(listArray)
 	if err != nil {
-		return nil, nil, fmt.Errorf("filterlist.NewRuleStorage(): %s", err)
+		return nil, nil, fmt.Errorf("filterlist.NewRuleStorage(): %w", err)
 	}
 	filteringEngine := urlfilter.NewDNSEngine(rulesStorage)
 	return rulesStorage, filteringEngine, nil
@@ -590,7 +588,7 @@ func (d *Dnsfilter) matchHost(host string, qtype uint16, setts RequestFilteringS
 				rule = rr.HostRulesV6[0]
 			}
 
-			log.Debug("Filtering: found whitelist rule for host '%s': '%s'  list_id: %d",
+			log.Debug("Filtering: found whitelist rule for host %q: %q  list_id: %d",
 				host, rule.Text(), rule.GetFilterListID())
 			res := makeResult(rule, NotFilteredWhiteList)
 			return res, nil
@@ -607,7 +605,7 @@ func (d *Dnsfilter) matchHost(host string, qtype uint16, setts RequestFilteringS
 	}
 
 	if rr.NetworkRule != nil {
-		log.Debug("Filtering: found rule for host '%s': '%s'  list_id: %d",
+		log.Debug("Filtering: found rule for host %q: %q  list_id: %d",
 			host, rr.NetworkRule.Text(), rr.NetworkRule.GetFilterListID())
 		reason := FilteredBlackList
 		if rr.NetworkRule.Whitelist {
@@ -619,7 +617,7 @@ func (d *Dnsfilter) matchHost(host string, qtype uint16, setts RequestFilteringS
 
 	if qtype == dns.TypeA && rr.HostRulesV4 != nil {
 		rule := rr.HostRulesV4[0] // note that we process only 1 matched rule
-		log.Debug("Filtering: found rule for host '%s': '%s'  list_id: %d",
+		log.Debug("Filtering: found rule for host %q: %q  list_id: %d",
 			host, rule.Text(), rule.GetFilterListID())
 		res := makeResult(rule, FilteredBlackList)
 		res.IP = rule.IP.To4()
@@ -628,7 +626,7 @@ func (d *Dnsfilter) matchHost(host string, qtype uint16, setts RequestFilteringS
 
 	if qtype == dns.TypeAAAA && rr.HostRulesV6 != nil {
 		rule := rr.HostRulesV6[0] // note that we process only 1 matched rule
-		log.Debug("Filtering: found rule for host '%s': '%s'  list_id: %d",
+		log.Debug("Filtering: found rule for host %q: %q  list_id: %d",
 			host, rule.Text(), rule.GetFilterListID())
 		res := makeResult(rule, FilteredBlackList)
 		res.IP = rule.IP
@@ -644,7 +642,7 @@ func (d *Dnsfilter) matchHost(host string, qtype uint16, setts RequestFilteringS
 		} else if rr.HostRulesV6 != nil {
 			rule = rr.HostRulesV6[0]
 		}
-		log.Debug("Filtering: found rule for host '%s': '%s'  list_id: %d",
+		log.Debug("Filtering: found rule for host %q: %q  list_id: %d",
 			host, rule.Text(), rule.GetFilterListID())
 		res := makeResult(rule, FilteredBlackList)
 		res.IP = net.IP{}
@@ -673,7 +671,6 @@ func InitModule() {
 
 // New creates properly initialized DNS Filter that is ready to be used
 func New(c *Config, blockFilters []Filter) *Dnsfilter {
-
 	if c != nil {
 		cacheConf := cache.Config{
 			EnableLRU: true,
@@ -713,7 +710,7 @@ func New(c *Config, blockFilters []Filter) *Dnsfilter {
 	bsvcs := []string{}
 	for _, s := range d.BlockedServices {
 		if !BlockedSvcKnown(s) {
-			log.Debug("skipping unknown blocked-service '%s'", s)
+			log.Debug("skipping unknown blocked-service %q", s)
 			continue
 		}
 		bsvcs = append(bsvcs, s)

internal/dnsforward/access.go

@@ -51,7 +51,7 @@ func (a *accessCtx) Init(allowedClients, disallowedClients, blockedHosts []strin
 	listArray = append(listArray, list)
 	rulesStorage, err := filterlist.NewRuleStorage(listArray)
 	if err != nil {
-		return fmt.Errorf("filterlist.NewRuleStorage(): %s", err)
+		return fmt.Errorf("filterlist.NewRuleStorage(): %w", err)
 	}
 	a.blockedHostsEngine = urlfilter.NewDNSEngine(rulesStorage)
 

internal/dnsforward/config.go

@@ -15,7 +15,6 @@ import (
 	"github.com/AdguardTeam/dnsproxy/proxy"
 	"github.com/AdguardTeam/dnsproxy/upstream"
 	"github.com/AdguardTeam/golibs/log"
-	"github.com/joomcode/errorx"
 )
 
 // FilteringConfig represents the DNS filtering configuration of AdGuard Home
@@ -252,14 +251,14 @@ func (s *Server) prepareUpstreamSettings() error {
 	upstreams = filterOutComments(upstreams)
 	upstreamConfig, err := proxy.ParseUpstreamsConfig(upstreams, s.conf.BootstrapDNS, DefaultTimeout)
 	if err != nil {
-		return fmt.Errorf("DNS: proxy.ParseUpstreamsConfig: %s", err)
+		return fmt.Errorf("dns: proxy.ParseUpstreamsConfig: %w", err)
 	}
 
 	if len(upstreamConfig.Upstreams) == 0 {
 		log.Info("Warning: no default upstream servers specified, using %v", defaultDNS)
 		uc, err := proxy.ParseUpstreamsConfig(defaultDNS, s.conf.BootstrapDNS, DefaultTimeout)
 		if err != nil {
-			return fmt.Errorf("DNS: failed to parse default upstreams: %v", err)
+			return fmt.Errorf("dns: failed to parse default upstreams: %v", err)
 		}
 		upstreamConfig.Upstreams = uc.Upstreams
 	}
@@ -300,13 +299,13 @@ func (s *Server) prepareTLS(proxyConfig *proxy.Config) error {
 	var err error
 	s.conf.cert, err = tls.X509KeyPair(s.conf.CertificateChainData, s.conf.PrivateKeyData)
 	if err != nil {
-		return errorx.Decorate(err, "Failed to parse TLS keypair")
+		return fmt.Errorf("failed to parse TLS keypair: %w", err)
 	}
 
 	if s.conf.StrictSNICheck {
 		x, err := x509.ParseCertificate(s.conf.cert.Certificate[0])
 		if err != nil {
-			return errorx.Decorate(err, "x509.ParseCertificate(): %s", err)
+			return fmt.Errorf("x509.ParseCertificate(): %w", err)
 		}
 		if len(x.DNSNames) != 0 {
 			s.conf.dnsNames = x.DNSNames

internal/dnsforward/dnsforward.go

@@ -15,7 +15,6 @@ import (
 	"github.com/AdguardTeam/AdGuardHome/internal/stats"
 	"github.com/AdguardTeam/dnsproxy/proxy"
 	"github.com/AdguardTeam/golibs/log"
-	"github.com/joomcode/errorx"
 	"github.com/miekg/dns"
 )
 
@@ -182,7 +181,7 @@ func (s *Server) Prepare(config *ServerConfig) error {
 			s.conf.BlockingIPAddrv4 = net.ParseIP(s.conf.BlockingIPv4)
 			s.conf.BlockingIPAddrv6 = net.ParseIP(s.conf.BlockingIPv6)
 			if s.conf.BlockingIPAddrv4 == nil || s.conf.BlockingIPAddrv6 == nil {
-				return fmt.Errorf("DNS: invalid custom blocking IP address specified")
+				return fmt.Errorf("dns: invalid custom blocking IP address specified")
 			}
 		}
 		if s.conf.MaxGoroutines == 0 {
@@ -250,7 +249,7 @@ func (s *Server) stopInternal() error {
 	if s.dnsProxy != nil {
 		err := s.dnsProxy.Stop()
 		if err != nil {
-			return errorx.Decorate(err, "could not stop the DNS server properly")
+			return fmt.Errorf("could not stop the DNS server properly: %w", err)
 		}
 	}
 
@@ -273,7 +272,7 @@ func (s *Server) Reconfigure(config *ServerConfig) error {
 	log.Print("Start reconfiguring the server")
 	err := s.stopInternal()
 	if err != nil {
-		return errorx.Decorate(err, "could not reconfigure the server")
+		return fmt.Errorf("could not reconfigure the server: %w", err)
 	}
 
 	// It seems that net.Listener.Close() doesn't close file descriptors right away.
@@ -282,12 +281,12 @@ func (s *Server) Reconfigure(config *ServerConfig) error {
 
 	err = s.Prepare(config)
 	if err != nil {
-		return errorx.Decorate(err, "could not reconfigure the server")
+		return fmt.Errorf("could not reconfigure the server: %w", err)
 	}
 
 	err = s.startInternal()
 	if err != nil {
-		return errorx.Decorate(err, "could not reconfigure the server")
+		return fmt.Errorf("could not reconfigure the server: %w", err)
 	}
 
 	return nil

internal/dnsforward/dnsforward_http.go

@@ -17,7 +17,7 @@ import (
 
 func httpError(r *http.Request, w http.ResponseWriter, code int, format string, args ...interface{}) {
 	text := fmt.Sprintf(format, args...)
-	log.Info("DNS: %s %s: %s", r.Method, r.URL, text)
+	log.Info("dns: %s %s: %s", r.Method, r.URL, text)
 	http.Error(w, text, code)
 }
 
@@ -102,7 +102,7 @@ func checkBootstrap(addr string) error {
 	}
 	_, err := upstream.NewResolver(addr, 0)
 	if err != nil {
-		return fmt.Errorf("invalid bootstrap server address: %s", err)
+		return fmt.Errorf("invalid bootstrap server address: %w", err)
 	}
 	return nil
 }
@@ -322,7 +322,7 @@ func separateUpstream(upstream string) (string, bool, error) {
 		// split domains and upstream string
 		domainsAndUpstream := strings.Split(strings.TrimPrefix(upstream, "[/"), "/]")
 		if len(domainsAndUpstream) != 2 {
-			return "", defaultUpstream, fmt.Errorf("wrong DNS upstream per domain specification: %s", upstream)
+			return "", defaultUpstream, fmt.Errorf("wrong dns upstream per domain specification: %s", upstream)
 		}
 
 		// split domains list and validate each one
@@ -357,7 +357,7 @@ func checkPlainDNS(upstream string) error {
 
 	_, err = strconv.ParseInt(port, 0, 64)
 	if err != nil {
-		return fmt.Errorf("%s is not a valid port: %s", port, err)
+		return fmt.Errorf("%s is not a valid port: %w", port, err)
 	}
 
 	return nil
@@ -405,7 +405,7 @@ func checkDNS(input string, bootstrap []string) error {
 	// separate upstream from domains list
 	input, defaultUpstream, err := separateUpstream(input)
 	if err != nil {
-		return fmt.Errorf("wrong upstream format: %s", err)
+		return fmt.Errorf("wrong upstream format: %w", err)
 	}
 
 	// No need to check this DNS server
@@ -414,17 +414,17 @@ func checkDNS(input string, bootstrap []string) error {
 	}
 
 	if _, err := validateUpstream(input); err != nil {
-		return fmt.Errorf("wrong upstream format: %s", err)
+		return fmt.Errorf("wrong upstream format: %w", err)
 	}
 
 	if len(bootstrap) == 0 {
 		bootstrap = defaultBootstrap
 	}
 
-	log.Debug("Checking if DNS %s works...", input)
+	log.Debug("checking if dns %s works...", input)
 	u, err := upstream.AddressToUpstream(input, upstream.Options{Bootstrap: bootstrap, Timeout: DefaultTimeout})
 	if err != nil {
-		return fmt.Errorf("failed to choose upstream for %s: %s", input, err)
+		return fmt.Errorf("failed to choose upstream for %s: %w", input, err)
 	}
 
 	req := dns.Msg{}
@@ -435,18 +435,18 @@ func checkDNS(input string, bootstrap []string) error {
 	}
 	reply, err := u.Exchange(&req)
 	if err != nil {
-		return fmt.Errorf("couldn't communicate with DNS server %s: %s", input, err)
+		return fmt.Errorf("couldn't communicate with dns server %s: %w", input, err)
 	}
 	if len(reply.Answer) != 1 {
-		return fmt.Errorf("DNS server %s returned wrong answer", input)
+		return fmt.Errorf("dns server %s returned wrong answer", input)
 	}
 	if t, ok := reply.Answer[0].(*dns.A); ok {
 		if !net.IPv4(8, 8, 8, 8).Equal(t.A) {
-			return fmt.Errorf("DNS server %s returned wrong answer: %v", input, t.A)
+			return fmt.Errorf("dns server %s returned wrong answer: %v", input, t.A)
 		}
 	}
 
-	log.Debug("DNS %s works OK", input)
+	log.Debug("dns %s works OK", input)
 	return nil
 }
 
@@ -462,7 +462,7 @@ func (s *Server) handleDOH(w http.ResponseWriter, r *http.Request) {
 	}
 
 	if !s.IsRunning() {
-		httpError(r, w, http.StatusInternalServerError, "DNS server is not running")
+		httpError(r, w, http.StatusInternalServerError, "dns server is not running")
 		return
 	}
 

internal/dnsforward/filter.go

@@ -1,12 +1,13 @@
 package dnsforward
 
 import (
+	"fmt"
 	"strings"
 
 	"github.com/AdguardTeam/AdGuardHome/internal/dnsfilter"
 	"github.com/AdguardTeam/dnsproxy/proxy"
 	"github.com/AdguardTeam/golibs/log"
-	"github.com/joomcode/errorx"
+
 	"github.com/miekg/dns"
 )
 
@@ -49,10 +50,9 @@ func (s *Server) filterDNSRequest(ctx *dnsContext) (*dnsfilter.Result, error) {
 	res, err := s.dnsFilter.CheckHost(host, d.Req.Question[0].Qtype, ctx.setts)
 	if err != nil {
 		// Return immediately if there's an error
-		return nil, errorx.Decorate(err, "dnsfilter failed to check host '%s'", host)
+		return nil, fmt.Errorf("dnsfilter failed to check host %q: %w", host, err)
-
 	} else if res.IsFiltered {
-		log.Tracef("Host %s is filtered, reason - '%s', matched rule: '%s'", host, res.Reason, res.Rule)
+		log.Tracef("Host %s is filtered, reason - %q, matched rule: %q", host, res.Reason, res.Rule)
 		d.Res = s.genDNSFilterMessage(d, &res)
 
 	} else if res.Reason == dnsfilter.ReasonRewrite && len(res.CanonName) != 0 && len(res.IPList) == 0 {
@@ -136,7 +136,6 @@ func (s *Server) filterDNSResponse(ctx *dnsContext) (*dnsfilter.Result, error) {
 
 		if err != nil {
 			return nil, err
-
 		} else if res.IsFiltered {
 			d.Res = s.genDNSFilterMessage(d, &res)
 			log.Debug("DNSFwd: Matched %s by response: %s", d.Req.Question[0].Name, host)

internal/dnsforward/ipset.go

@@ -31,13 +31,13 @@ func (c *ipsetCtx) init(ipsetConfig []string) {
 		it = strings.TrimSpace(it)
 		hostsAndNames := strings.Split(it, "/")
 		if len(hostsAndNames) != 2 {
-			log.Debug("IPSET: invalid value '%s'", it)
+			log.Debug("IPSET: invalid value %q", it)
 			continue
 		}
 
 		ipsetNames := strings.Split(hostsAndNames[1], ",")
 		if len(ipsetNames) == 0 {
-			log.Debug("IPSET: invalid value '%s'", it)
+			log.Debug("IPSET: invalid value %q", it)
 			continue
 		}
 		bad := false
@@ -49,7 +49,7 @@ func (c *ipsetCtx) init(ipsetConfig []string) {
 			}
 		}
 		if bad {
-			log.Debug("IPSET: invalid value '%s'", it)
+			log.Debug("IPSET: invalid value %q", it)
 			continue
 		}
 
@@ -58,7 +58,7 @@ func (c *ipsetCtx) init(ipsetConfig []string) {
 			host = strings.TrimSpace(host)
 			host = strings.ToLower(host)
 			if len(host) == 0 {
-				log.Debug("IPSET: invalid value '%s'", it)
+				log.Debug("IPSET: invalid value %q", it)
 				continue
 			}
 			c.ipsetList[host] = ipsetNames
@@ -131,7 +131,7 @@ func (c *ipsetCtx) process(ctx *dnsContext) int {
 				continue
 			}
 			if code != 0 {
-				log.Info("IPSET: ipset add:  code:%d  output:'%s'", code, out)
+				log.Info("IPSET: ipset add:  code:%d  output:%q", code, out)
 				continue
 			}
 			log.Debug("IPSET: added %s(%s) -> %s", host, ipStr, name)

internal/dnsforward/msg.go

@@ -46,7 +46,6 @@ func (s *Server) genDNSFilterMessage(d *proxy.DNSContext, result *dnsfilter.Resu
 		if s.conf.BlockingMode == "null_ip" {
 			// it means that we should return 0.0.0.0 or :: for any blocked request
 			return s.makeResponseNullIP(m)
-
 		} else if s.conf.BlockingMode == "custom_ip" {
 			// means that we should return custom IP for any blocked request
 
@@ -56,12 +55,10 @@ func (s *Server) genDNSFilterMessage(d *proxy.DNSContext, result *dnsfilter.Resu
 			case dns.TypeAAAA:
 				return s.genAAAARecord(m, s.conf.BlockingIPAddrv6)
 			}
-
 		} else if s.conf.BlockingMode == "nxdomain" {
 			// means that we should return NXDOMAIN for any blocked request
 
 			return s.genNXDomain(m)
-
 		} else if s.conf.BlockingMode == "refused" {
 			// means that we should return NXDOMAIN for any blocked request
 
@@ -148,7 +145,6 @@ func (s *Server) makeResponseNullIP(req *dns.Msg) *dns.Msg {
 }
 
 func (s *Server) genBlockedHost(request *dns.Msg, newAddr string, d *proxy.DNSContext) *dns.Msg {
-
 	ip := net.ParseIP(newAddr)
 	if ip != nil {
 		return s.genResponseWithIP(request, ip)
@@ -168,7 +164,7 @@ func (s *Server) genBlockedHost(request *dns.Msg, newAddr string, d *proxy.DNSCo
 
 	err := s.dnsProxy.Resolve(newContext)
 	if err != nil {
-		log.Printf("Couldn't look up replacement host '%s': %s", newAddr, err)
+		log.Printf("Couldn't look up replacement host %q: %s", newAddr, err)
 		return s.genServerFailure(request)
 	}
 

internal/home/auth.go

@@ -17,8 +17,10 @@ import (
 	"golang.org/x/crypto/bcrypt"
 )
 
-const cookieTTL = 365 * 24 // in hours
+const (
-const sessionCookieName = "agh_session"
+	cookieTTL         = 365 * 24 // in hours
+	sessionCookieName = "agh_session"
+)
 
 type session struct {
 	userName string
@@ -78,7 +80,7 @@ func InitAuth(dbFilename string, users []User, sessionTTL uint32) *Auth {
 	a.sessions = make(map[string]*session)
 	rand.Seed(time.Now().UTC().Unix())
 	var err error
-	a.db, err = bbolt.Open(dbFilename, 0644, nil)
+	a.db, err = bbolt.Open(dbFilename, 0o644, nil)
 	if err != nil {
 		log.Error("Auth: open DB: %s: %s", dbFilename, err)
 		if err.Error() == "invalid argument" {
@@ -318,7 +320,7 @@ func handleLogin(w http.ResponseWriter, r *http.Request) {
 
 	cookie := Context.auth.httpCookie(req)
 	if len(cookie) == 0 {
-		log.Info("Auth: invalid user name or password: name='%s'", req.Name)
+		log.Info("Auth: invalid user name or password: name=%q", req.Name)
 		time.Sleep(1 * time.Second)
 		http.Error(w, "invalid user name or password", http.StatusBadRequest)
 		return
@@ -372,7 +374,6 @@ func parseCookie(cookie string) string {
 // nolint(gocyclo)
 func optionalAuth(handler func(http.ResponseWriter, *http.Request)) 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()
@@ -424,7 +425,6 @@ func optionalAuth(handler func(http.ResponseWriter, *http.Request)) func(http.Re
 				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)

internal/home/clients.go

@@ -126,7 +126,6 @@ func (clients *clientsContainer) Start() {
 		}
 		go clients.periodicUpdate()
 	}
-
 }
 
 // Reload - reload auto-clients
@@ -173,7 +172,7 @@ func (clients *clientsContainer) addFromConfig(objects []clientObject) {
 
 		for _, s := range cy.BlockedServices {
 			if !dnsfilter.BlockedSvcKnown(s) {
-				log.Debug("Clients: skipping unknown blocked-service '%s'", s)
+				log.Debug("Clients: skipping unknown blocked-service %q", s)
 				continue
 			}
 			cli.BlockedServices = append(cli.BlockedServices, s)
@@ -181,7 +180,7 @@ func (clients *clientsContainer) addFromConfig(objects []clientObject) {
 
 		for _, t := range cy.Tags {
 			if !clients.tagKnown(t) {
-				log.Debug("Clients: skipping unknown tag '%s'", t)
+				log.Debug("Clients: skipping unknown tag %q", t)
 				continue
 			}
 			cli.Tags = append(cli.Tags, t)
@@ -377,7 +376,7 @@ func (clients *clientsContainer) check(c *Client) error {
 	}
 
 	if len(c.IDs) == 0 {
-		return fmt.Errorf("ID required")
+		return fmt.Errorf("id required")
 	}
 
 	for i, id := range c.IDs {
@@ -409,7 +408,7 @@ func (clients *clientsContainer) check(c *Client) error {
 
 	err := dnsforward.ValidateUpstreams(c.Upstreams)
 	if err != nil {
-		return fmt.Errorf("invalid upstream servers: %s", err)
+		return fmt.Errorf("invalid upstream servers: %w", err)
 	}
 
 	return nil
@@ -448,7 +447,7 @@ func (clients *clientsContainer) Add(c Client) (bool, error) {
 		clients.idIndex[id] = &c
 	}
 
-	log.Debug("Clients: added '%s': ID:%v [%d]", c.Name, c.IDs, len(clients.list))
+	log.Debug("Clients: added %q: ID:%v [%d]", c.Name, c.IDs, len(clients.list))
 	return true, nil
 }
 
@@ -590,7 +589,7 @@ func (clients *clientsContainer) addHost(ip, host string, source clientSource) (
 		}
 		clients.ipHost[ip] = ch
 	}
-	log.Debug("Clients: added '%s' -> '%s' [%d]", ip, host, len(clients.ipHost))
+	log.Debug("Clients: added %q -> %q [%d]", ip, host, len(clients.ipHost))
 	return true, nil
 }
 

internal/home/control_install.go

@@ -71,6 +71,7 @@ type checkConfigReqEnt struct {
 	IP      string `json:"ip"`
 	Autofix bool   `json:"autofix"`
 }
+
 type checkConfigReq struct {
 	Web         checkConfigReqEnt `json:"web"`
 	DNS         checkConfigReqEnt `json:"dns"`
@@ -81,11 +82,13 @@ type checkConfigRespEnt struct {
 	Status     string `json:"status"`
 	CanAutofix bool   `json:"can_autofix"`
 }
+
 type staticIPJSON struct {
 	Static string `json:"static"`
 	IP     string `json:"ip"`
 	Error  string `json:"error"`
 }
+
 type checkConfigResp struct {
 	Web      checkConfigRespEnt `json:"web"`
 	DNS      checkConfigRespEnt `json:"dns"`
@@ -214,31 +217,33 @@ func checkDNSStubListener() bool {
 	return true
 }
 
-const resolvedConfPath = "/etc/systemd/resolved.conf.d/adguardhome.conf"
+const (
-const resolvedConfData = `[Resolve]
+	resolvedConfPath = "/etc/systemd/resolved.conf.d/adguardhome.conf"
+	resolvedConfData = `[Resolve]
 DNS=127.0.0.1
 DNSStubListener=no
 `
+)
 const resolvConfPath = "/etc/resolv.conf"
 
 // Deactivate DNSStubListener
 func disableDNSStubListener() error {
 	dir := filepath.Dir(resolvedConfPath)
-	err := os.MkdirAll(dir, 0755)
+	err := os.MkdirAll(dir, 0o755)
 	if err != nil {
-		return fmt.Errorf("os.MkdirAll: %s: %s", dir, err)
+		return fmt.Errorf("os.MkdirAll: %s: %w", dir, err)
 	}
 
-	err = ioutil.WriteFile(resolvedConfPath, []byte(resolvedConfData), 0644)
+	err = ioutil.WriteFile(resolvedConfPath, []byte(resolvedConfData), 0o644)
 	if err != nil {
-		return fmt.Errorf("ioutil.WriteFile: %s: %s", resolvedConfPath, err)
+		return fmt.Errorf("ioutil.WriteFile: %s: %w", resolvedConfPath, err)
 	}
 
 	_ = os.Rename(resolvConfPath, resolvConfPath+".backup")
 	err = os.Symlink("/run/systemd/resolve/resolv.conf", resolvConfPath)
 	if err != nil {
 		_ = os.Remove(resolvedConfPath) // remove the file we've just created
-		return fmt.Errorf("os.Symlink: %s: %s", resolvConfPath, err)
+		return fmt.Errorf("os.Symlink: %s: %w", resolvConfPath, err)
 	}
 
 	cmd := exec.Command("systemctl", "reload-or-restart", "systemd-resolved")
@@ -259,6 +264,7 @@ type applyConfigReqEnt struct {
 	IP   string `json:"ip"`
 	Port int    `json:"port"`
 }
+
 type applyConfigReq struct {
 	Web      applyConfigReqEnt `json:"web"`
 	DNS      applyConfigReqEnt `json:"dns"`

internal/home/dns.go

@@ -12,7 +12,6 @@ import (
 	"github.com/AdguardTeam/AdGuardHome/internal/util"
 	"github.com/AdguardTeam/dnsproxy/proxy"
 	"github.com/AdguardTeam/golibs/log"
-	"github.com/joomcode/errorx"
 )
 
 // Called by other modules when configuration is changed
@@ -75,7 +74,7 @@ func initDNSServer() error {
 	err = Context.dnsServer.Prepare(&dnsConfig)
 	if err != nil {
 		closeDNSServer()
-		return fmt.Errorf("dnsServer.Prepare: %s", err)
+		return fmt.Errorf("dnsServer.Prepare: %w", err)
 	}
 
 	Context.rdns = InitRDNS(Context.dnsServer, &Context.clients)
@@ -96,41 +95,41 @@ func isPublicIP(ip net.IP) bool {
 	if ip4 != nil {
 		switch ip4[0] {
 		case 0:
-			return false //software
+			return false // software
 		case 10:
-			return false //private network
+			return false // private network
 		case 127:
-			return false //loopback
+			return false // loopback
 		case 169:
 			if ip4[1] == 254 {
-				return false //link-local
+				return false // link-local
 			}
 		case 172:
 			if ip4[1] >= 16 && ip4[1] <= 31 {
-				return false //private network
+				return false // private network
 			}
 		case 192:
-			if (ip4[1] == 0 && ip4[2] == 0) || //private network
+			if (ip4[1] == 0 && ip4[2] == 0) || // private network
-				(ip4[1] == 0 && ip4[2] == 2) || //documentation
+				(ip4[1] == 0 && ip4[2] == 2) || // documentation
-				(ip4[1] == 88 && ip4[2] == 99) || //reserved
+				(ip4[1] == 88 && ip4[2] == 99) || // reserved
-				(ip4[1] == 168) { //private network
+				(ip4[1] == 168) { // private network
 				return false
 			}
 		case 198:
-			if (ip4[1] == 18 || ip4[2] == 19) || //private network
+			if (ip4[1] == 18 || ip4[2] == 19) || // private network
-				(ip4[1] == 51 || ip4[2] == 100) { //documentation
+				(ip4[1] == 51 || ip4[2] == 100) { // documentation
 				return false
 			}
 		case 203:
-			if ip4[1] == 0 && ip4[2] == 113 { //documentation
+			if ip4[1] == 0 && ip4[2] == 113 { // documentation
 				return false
 			}
 		case 224:
-			if ip4[1] == 0 && ip4[2] == 0 { //multicast
+			if ip4[1] == 0 && ip4[2] == 0 { // multicast
 				return false
 			}
 		case 255:
-			if ip4[1] == 255 && ip4[2] == 255 && ip4[3] == 255 { //subnet
+			if ip4[1] == 255 && ip4[2] == 255 && ip4[3] == 255 { // subnet
 				return false
 			}
 		}
@@ -313,7 +312,7 @@ func startDNSServer() error {
 
 	err := Context.dnsServer.Start()
 	if err != nil {
-		return errorx.Decorate(err, "Couldn't start forwarding DNS server")
+		return fmt.Errorf("couldn't start forwarding DNS server: %w", err)
 	}
 
 	Context.dnsFilter.Start()
@@ -340,7 +339,7 @@ func reconfigureDNSServer() error {
 	newconfig := generateServerConfig()
 	err := Context.dnsServer.Reconfigure(&newconfig)
 	if err != nil {
-		return errorx.Decorate(err, "Couldn't start forwarding DNS server")
+		return fmt.Errorf("couldn't start forwarding DNS server: %w", err)
 	}
 
 	return nil
@@ -353,7 +352,7 @@ func stopDNSServer() error {
 
 	err := Context.dnsServer.Stop()
 	if err != nil {
-		return errorx.Decorate(err, "Couldn't stop forwarding DNS server")
+		return fmt.Errorf("couldn't stop forwarding DNS server: %w", err)
 	}
 
 	closeDNSServer()

internal/home/filter.go

@@ -20,9 +20,7 @@ import (
 	"github.com/AdguardTeam/golibs/log"
 )
 
-var (
+var nextFilterID = time.Now().Unix() // semi-stable way to generate an unique ID
-	nextFilterID = time.Now().Unix() // semi-stable way to generate an unique ID
-)
 
 // Filtering - module object
 type Filtering struct {
@@ -35,7 +33,7 @@ type Filtering struct {
 // Init - initialize the module
 func (f *Filtering) Init() {
 	f.filterTitleRegexp = regexp.MustCompile(`^! Title: +(.*)$`)
-	_ = os.MkdirAll(filepath.Join(Context.getDataDir(), filterDir), 0755)
+	_ = os.MkdirAll(filepath.Join(Context.getDataDir(), filterDir), 0o755)
 	f.loadFilters(config.Filters)
 	f.loadFilters(config.WhitelistFilters)
 	deduplicateFilters()
@@ -466,7 +464,6 @@ func (f *Filtering) parseFilterContents(file io.Reader) (int, uint32, string) {
 		line = strings.TrimSpace(line)
 		if len(line) == 0 {
 			//
-
 		} else if line[0] == '!' {
 			m := f.filterTitleRegexp.FindAllStringSubmatch(line, -1)
 			if len(m) > 0 && len(m[0]) >= 2 && !seenTitle {
@@ -476,7 +473,6 @@ func (f *Filtering) parseFilterContents(file io.Reader) (int, uint32, string) {
 
 		} else if line[0] == '#' {
 			//
-
 		} else {
 			rulesCount++
 		}
@@ -521,7 +517,7 @@ func (f *Filtering) updateIntl(filter *filter) (bool, error) {
 	if filepath.IsAbs(filter.URL) {
 		f, err := os.Open(filter.URL)
 		if err != nil {
-			return false, fmt.Errorf("open file: %s", err)
+			return false, fmt.Errorf("open file: %w", err)
 		}
 		defer f.Close()
 		reader = f

internal/home/home.go

@@ -22,11 +22,10 @@ import (
 
 	"gopkg.in/natefinch/lumberjack.v2"
 
+	"github.com/AdguardTeam/AdGuardHome/internal/agherr"
 	"github.com/AdguardTeam/AdGuardHome/internal/update"
 	"github.com/AdguardTeam/AdGuardHome/internal/util"
 
-	"github.com/joomcode/errorx"
-
 	"github.com/AdguardTeam/AdGuardHome/internal/isdelve"
 
 	"github.com/AdguardTeam/AdGuardHome/internal/dhcpd"
@@ -113,7 +112,7 @@ func Main(version string, channel string, armVer string) {
 	go func() {
 		for {
 			sig := <-Context.appSignalChannel
-			log.Info("Received signal '%s'", sig)
+			log.Info("Received signal %q", sig)
 			switch sig {
 			case syscall.SIGHUP:
 				Context.clients.Reload()
@@ -279,7 +278,7 @@ func run(args options) {
 		}
 	}
 
-	err := os.MkdirAll(Context.getDataDir(), 0755)
+	err := os.MkdirAll(Context.getDataDir(), 0o755)
 	if err != nil {
 		log.Fatalf("Cannot create DNS data dir at %s: %s", Context.getDataDir(), err)
 	}
@@ -358,7 +357,7 @@ func checkPermissions() {
 		// On Windows we need to have admin rights to run properly
 
 		admin, _ := util.HaveAdminRights()
-		if //noinspection ALL
+		if // noinspection ALL
 		admin || isdelve.Enabled {
 			// Don't forget that for this to work you need to add "delve" tag explicitly
 			// https://stackoverflow.com/questions/47879070/how-can-i-see-if-the-goland-debugger-is-running-in-the-program
@@ -404,7 +403,7 @@ Please note, that this is crucial for a DNS server to be able to use that port.`
 // Write PID to a file
 func writePIDFile(fn string) bool {
 	data := fmt.Sprintf("%d", os.Getpid())
-	err := ioutil.WriteFile(fn, []byte(data), 0644)
+	err := ioutil.WriteFile(fn, []byte(data), 0o644)
 	if err != nil {
 		log.Error("Couldn't write PID to file %s: %v", fn, err)
 		return false
@@ -487,7 +486,7 @@ func configureLogger(args options) {
 			logFilePath = ls.LogFile
 		}
 
-		_, err := os.OpenFile(logFilePath, os.O_WRONLY|os.O_CREATE|os.O_APPEND, 0644)
+		_, err := os.OpenFile(logFilePath, os.O_WRONLY|os.O_CREATE|os.O_APPEND, 0o644)
 		if err != nil {
 			log.Fatalf("cannot create a log file: %s", err)
 		}
@@ -498,7 +497,7 @@ func configureLogger(args options) {
 			LocalTime:  ls.LogLocalTime,
 			MaxBackups: ls.LogMaxBackups,
 			MaxSize:    ls.LogMaxSize, // megabytes
-			MaxAge:     ls.LogMaxAge,  //days
+			MaxAge:     ls.LogMaxAge,  // days
 		})
 	}
 }
@@ -662,7 +661,7 @@ func customDialContext(ctx context.Context, network, addr string) (net.Conn, err
 		}
 		return con, err
 	}
-	return nil, errorx.DecorateMany(fmt.Sprintf("couldn't dial to %s", addr), dialErrs...)
+	return nil, agherr.Many(fmt.Sprintf("couldn't dial to %s", addr), dialErrs...)
 }
 
 func getHTTPProxy(req *http.Request) (*url.URL, error) {

internal/home/options.go

@@ -106,7 +106,7 @@ var portArg = arg{
 		var p int
 		minPort, maxPort := 0, 1<<16-1
 		if p, err = strconv.Atoi(v); err != nil {
-			err = fmt.Errorf("port '%s' is not a number", v)
+			err = fmt.Errorf("port %q is not a number", v)
 		} else if p < minPort || p > maxPort {
 			err = fmt.Errorf("port %d not in range %d - %d", p, minPort, maxPort)
 		} else {

internal/home/tls.go

@@ -20,7 +20,6 @@ import (
 	"time"
 
 	"github.com/AdguardTeam/golibs/log"
-	"github.com/joomcode/errorx"
 )
 
 var tlsWebHandlersRegistered = false
@@ -484,13 +483,13 @@ func unmarshalTLS(r *http.Request) (tlsConfigSettings, error) {
 	data := tlsConfigSettings{}
 	err := json.NewDecoder(r.Body).Decode(&data)
 	if err != nil {
-		return data, errorx.Decorate(err, "Failed to parse new TLS config json")
+		return data, fmt.Errorf("failed to parse new TLS config json: %w", err)
 	}
 
 	if data.CertificateChain != "" {
 		certPEM, err := base64.StdEncoding.DecodeString(data.CertificateChain)
 		if err != nil {
-			return data, errorx.Decorate(err, "Failed to base64-decode certificate chain")
+			return data, fmt.Errorf("failed to base64-decode certificate chain: %w", err)
 		}
 		data.CertificateChain = string(certPEM)
 		if data.CertificatePath != "" {
@@ -501,7 +500,7 @@ func unmarshalTLS(r *http.Request) (tlsConfigSettings, error) {
 	if data.PrivateKey != "" {
 		keyPEM, err := base64.StdEncoding.DecodeString(data.PrivateKey)
 		if err != nil {
-			return data, errorx.Decorate(err, "Failed to base64-decode private key")
+			return data, fmt.Errorf("failed to base64-decode private key: %w", err)
 		}
 
 		data.PrivateKey = string(keyPEM)

internal/home/upgrade.go

@@ -184,7 +184,7 @@ func upgradeSchema2to3(diskConfig *map[string]interface{}) error {
 			newDNSConfig[fmt.Sprint(k)] = v
 		}
 	default:
-		return fmt.Errorf("DNS configuration is not a map")
+		return fmt.Errorf("dns configuration is not a map")
 	}
 
 	// Replace bootstrap_dns value filed with new array contains old bootstrap_dns inside
@@ -217,7 +217,6 @@ func upgradeSchema3to4(diskConfig *map[string]interface{}) error {
 	case []interface{}:
 
 		for i := range arr {
-
 			switch c := arr[i].(type) {
 
 			case map[interface{}]interface{}:
@@ -309,7 +308,6 @@ func upgradeSchema5to6(diskConfig *map[string]interface{}) error {
 	case []interface{}:
 
 		for i := range arr {
-
 			switch c := arr[i].(type) {
 
 			case map[interface{}]interface{}:

internal/home/whois.go

@@ -168,7 +168,7 @@ func (w *Whois) queryAll(target string) (string, error) {
 
 		log.Debug("Whois: redirected to %s  IP:%s", redir, target)
 	}
-	return "", fmt.Errorf("Whois: redirect loop")
+	return "", fmt.Errorf("whois: redirect loop")
 }
 
 // Request WHOIS information

internal/querylog/qlog_reader.go

@@ -3,7 +3,7 @@ package querylog
 import (
 	"io"
 
-	"github.com/joomcode/errorx"
+	"github.com/AdguardTeam/AdGuardHome/internal/agherr"
 )
 
 // QLogReader allows reading from multiple query log files in the reverse order.
@@ -132,7 +132,7 @@ func closeQFiles(qFiles []*QLogFile) error {
 	}
 
 	if len(errs) > 0 {
-		return errorx.DecorateMany("Error while closing QLogReader", errs...)
+		return agherr.Many("Error while closing QLogReader", errs...)
 	}
 
 	return nil

internal/update/check.go

@@ -32,12 +32,12 @@ func (u *Updater) GetVersionResponse(forceRecheck bool) (VersionInfo, error) {
 	}
 
 	if err != nil {
-		return VersionInfo{}, fmt.Errorf("updater: HTTP GET %s: %s", u.VersionURL, err)
+		return VersionInfo{}, fmt.Errorf("updater: HTTP GET %s: %w", u.VersionURL, err)
 	}
 
 	body, err := ioutil.ReadAll(resp.Body)
 	if err != nil {
-		return VersionInfo{}, fmt.Errorf("updater: HTTP GET %s: %s", u.VersionURL, err)
+		return VersionInfo{}, fmt.Errorf("updater: HTTP GET %s: %w", u.VersionURL, err)
 	}
 
 	u.versionJSON = body
@@ -51,7 +51,7 @@ func (u *Updater) parseVersionResponse(data []byte) (VersionInfo, error) {
 	versionJSON := make(map[string]interface{})
 	err := json.Unmarshal(data, &versionJSON)
 	if err != nil {
-		return info, fmt.Errorf("version.json: %s", err)
+		return info, fmt.Errorf("version.json: %w", err)
 	}
 
 	var ok1, ok2, ok3, ok4 bool

internal/update/updater.go

@@ -138,13 +138,13 @@ func (u *Updater) unpack() error {
 	if strings.HasSuffix(pkgNameOnly, ".zip") {
 		u.unpackedFiles, err = zipFileUnpack(u.packageName, u.updateDir)
 		if err != nil {
-			return fmt.Errorf(".zip unpack failed: %s", err)
+			return fmt.Errorf(".zip unpack failed: %w", err)
 		}
 
 	} else if strings.HasSuffix(pkgNameOnly, ".tar.gz") {
 		u.unpackedFiles, err = tarGzFileUnpack(u.packageName, u.updateDir)
 		if err != nil {
-			return fmt.Errorf(".tar.gz unpack failed: %s", err)
+			return fmt.Errorf(".tar.gz unpack failed: %w", err)
 		}
 
 	} else {
@@ -158,7 +158,7 @@ func (u *Updater) check() error {
 	log.Debug("updater: checking configuration")
 	err := copyFile(u.ConfigName, filepath.Join(u.updateDir, "AdGuardHome.yaml"))
 	if err != nil {
-		return fmt.Errorf("copyFile() failed: %s", err)
+		return fmt.Errorf("copyFile() failed: %w", err)
 	}
 	cmd := exec.Command(u.updateExeName, "--check-config")
 	err = cmd.Run()
@@ -170,10 +170,10 @@ func (u *Updater) check() error {
 
 func (u *Updater) backup() error {
 	log.Debug("updater: backing up the current configuration")
-	_ = os.Mkdir(u.backupDir, 0755)
+	_ = os.Mkdir(u.backupDir, 0o755)
 	err := copyFile(u.ConfigName, filepath.Join(u.backupDir, "AdGuardHome.yaml"))
 	if err != nil {
-		return fmt.Errorf("copyFile() failed: %s", err)
+		return fmt.Errorf("copyFile() failed: %w", err)
 	}
 
 	// workdir/README.md -> backup/README.md
@@ -221,7 +221,7 @@ func (u *Updater) clean() {
 func (u *Updater) downloadPackageFile(url string, filename string) error {
 	resp, err := u.Client.Get(url)
 	if err != nil {
-		return fmt.Errorf("HTTP request failed: %s", err)
+		return fmt.Errorf("http request failed: %w", err)
 	}
 	if resp != nil && resp.Body != nil {
 		defer resp.Body.Close()
@@ -230,15 +230,15 @@ func (u *Updater) downloadPackageFile(url string, filename string) error {
 	log.Debug("updater: reading HTTP body")
 	body, err := ioutil.ReadAll(resp.Body)
 	if err != nil {
-		return fmt.Errorf("ioutil.ReadAll() failed: %s", err)
+		return fmt.Errorf("ioutil.ReadAll() failed: %w", err)
 	}
 
-	_ = os.Mkdir(u.updateDir, 0755)
+	_ = os.Mkdir(u.updateDir, 0o755)
 
 	log.Debug("updater: saving package to file")
-	err = ioutil.WriteFile(filename, body, 0644)
+	err = ioutil.WriteFile(filename, body, 0o644)
 	if err != nil {
-		return fmt.Errorf("ioutil.WriteFile() failed: %s", err)
+		return fmt.Errorf("ioutil.WriteFile() failed: %w", err)
 	}
 	return nil
 }
@@ -250,7 +250,7 @@ func (u *Updater) downloadPackageFile(url string, filename string) error {
 func tarGzFileUnpack(tarfile, outdir string) ([]string, error) {
 	f, err := os.Open(tarfile)
 	if err != nil {
-		return nil, fmt.Errorf("os.Open(): %s", err)
+		return nil, fmt.Errorf("os.Open(): %w", err)
 	}
 	defer func() {
 		_ = f.Close()
@@ -258,7 +258,7 @@ func tarGzFileUnpack(tarfile, outdir string) ([]string, error) {
 
 	gzReader, err := gzip.NewReader(f)
 	if err != nil {
-		return nil, fmt.Errorf("gzip.NewReader(): %s", err)
+		return nil, fmt.Errorf("gzip.NewReader(): %w", err)
 	}
 
 	var files []string
@@ -271,7 +271,7 @@ func tarGzFileUnpack(tarfile, outdir string) ([]string, error) {
 			break
 		}
 		if err != nil {
-			err2 = fmt.Errorf("tarReader.Next(): %s", err)
+			err2 = fmt.Errorf("tarReader.Next(): %w", err)
 			break
 		}
 
@@ -283,9 +283,9 @@ func tarGzFileUnpack(tarfile, outdir string) ([]string, error) {
 		outputName := filepath.Join(outdir, inputNameOnly)
 
 		if header.Typeflag == tar.TypeDir {
-			err = os.Mkdir(outputName, os.FileMode(header.Mode&0777))
+			err = os.Mkdir(outputName, os.FileMode(header.Mode&0o777))
 			if err != nil && !os.IsExist(err) {
-				err2 = fmt.Errorf("os.Mkdir(%s): %s", outputName, err)
+				err2 = fmt.Errorf("os.Mkdir(%s): %w", outputName, err)
 				break
 			}
 			log.Debug("updater: created directory %s", outputName)
@@ -295,20 +295,20 @@ func tarGzFileUnpack(tarfile, outdir string) ([]string, error) {
 			continue
 		}
 
-		f, err := os.OpenFile(outputName, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, os.FileMode(header.Mode&0777))
+		f, err := os.OpenFile(outputName, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, os.FileMode(header.Mode&0o777))
 		if err != nil {
-			err2 = fmt.Errorf("os.OpenFile(%s): %s", outputName, err)
+			err2 = fmt.Errorf("os.OpenFile(%s): %w", outputName, err)
 			break
 		}
 		_, err = io.Copy(f, tarReader)
 		if err != nil {
 			_ = f.Close()
-			err2 = fmt.Errorf("io.Copy(): %s", err)
+			err2 = fmt.Errorf("io.Copy(): %w", err)
 			break
 		}
 		err = f.Close()
 		if err != nil {
-			err2 = fmt.Errorf("f.Close(): %s", err)
+			err2 = fmt.Errorf("f.Close(): %w", err)
 			break
 		}
 
@@ -327,7 +327,7 @@ func tarGzFileUnpack(tarfile, outdir string) ([]string, error) {
 func zipFileUnpack(zipfile, outdir string) ([]string, error) {
 	r, err := zip.OpenReader(zipfile)
 	if err != nil {
-		return nil, fmt.Errorf("zip.OpenReader(): %s", err)
+		return nil, fmt.Errorf("zip.OpenReader(): %w", err)
 	}
 	defer r.Close()
 
@@ -337,7 +337,7 @@ func zipFileUnpack(zipfile, outdir string) ([]string, error) {
 	for _, zf := range r.File {
 		zr, err = zf.Open()
 		if err != nil {
-			err2 = fmt.Errorf("zip file Open(): %s", err)
+			err2 = fmt.Errorf("zip file Open(): %w", err)
 			break
 		}
 
@@ -352,7 +352,7 @@ func zipFileUnpack(zipfile, outdir string) ([]string, error) {
 		if fi.IsDir() {
 			err = os.Mkdir(outputName, fi.Mode())
 			if err != nil && !os.IsExist(err) {
-				err2 = fmt.Errorf("os.Mkdir(): %s", err)
+				err2 = fmt.Errorf("os.Mkdir(): %w", err)
 				break
 			}
 			log.Tracef("created directory %s", outputName)
@@ -361,18 +361,18 @@ func zipFileUnpack(zipfile, outdir string) ([]string, error) {
 
 		f, err := os.OpenFile(outputName, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, fi.Mode())
 		if err != nil {
-			err2 = fmt.Errorf("os.OpenFile(): %s", err)
+			err2 = fmt.Errorf("os.OpenFile(): %w", err)
 			break
 		}
 		_, err = io.Copy(f, zr)
 		if err != nil {
 			_ = f.Close()
-			err2 = fmt.Errorf("io.Copy(): %s", err)
+			err2 = fmt.Errorf("io.Copy(): %w", err)
 			break
 		}
 		err = f.Close()
 		if err != nil {
-			err2 = fmt.Errorf("f.Close(): %s", err)
+			err2 = fmt.Errorf("f.Close(): %w", err)
 			break
 		}
 
@@ -390,7 +390,7 @@ func copyFile(src, dst string) error {
 	if e != nil {
 		return e
 	}
-	e = ioutil.WriteFile(dst, d, 0644)
+	e = ioutil.WriteFile(dst, d, 0o644)
 	if e != nil {
 		return e
 	}

internal/util/network_utils.go

@@ -11,8 +11,6 @@ import (
 	"time"
 
 	"github.com/AdguardTeam/golibs/log"
-
-	"github.com/joomcode/errorx"
 )
 
 // NetInterface represents a list of network interfaces
@@ -30,7 +28,7 @@ type NetInterface struct {
 func GetValidNetInterfaces() ([]net.Interface, error) {
 	ifaces, err := net.Interfaces()
 	if err != nil {
-		return nil, fmt.Errorf("couldn't get list of interfaces: %s", err)
+		return nil, fmt.Errorf("couldn't get list of interfaces: %w", err)
 	}
 
 	netIfaces := []net.Interface{}
@@ -48,7 +46,7 @@ func GetValidNetInterfaces() ([]net.Interface, error) {
 func GetValidNetInterfacesForWeb() ([]NetInterface, error) {
 	ifaces, err := GetValidNetInterfaces()
 	if err != nil {
-		return nil, errorx.Decorate(err, "Couldn't get interfaces")
+		return nil, fmt.Errorf("couldn't get interfaces: %w", err)
 	}
 	if len(ifaces) == 0 {
 		return nil, errors.New("couldn't find any legible interface")
@@ -57,9 +55,9 @@ func GetValidNetInterfacesForWeb() ([]NetInterface, error) {
 	var netInterfaces []NetInterface
 
 	for _, iface := range ifaces {
-		addrs, e := iface.Addrs()
+		addrs, err := iface.Addrs()
-		if e != nil {
+		if err != nil {
-			return nil, errorx.Decorate(e, "Failed to get addresses for interface %s", iface.Name)
+			return nil, fmt.Errorf("failed to get addresses for interface %s: %w", iface.Name, err)
 		}
 
 		netIface := NetInterface{