Added golangci-lint configuration and prepared for the integrattion

.golangci.yml

@@ -0,0 +1,55 @@
+# options for analysis running
+run:
+  # default concurrency is a available CPU number
+  concurrency: 4
+
+  # timeout for analysis, e.g. 30s, 5m, default is 1m
+  deadline: 2m
+
+  # which files to skip: they will be analyzed, but issues from them
+  # won't be reported. Default value is empty list, but there is
+  # no need to include all autogenerated files, we confidently recognize
+  # autogenerated files. If it's not please let us know.
+  skip-files:
+    - ".*generated.*"
+    - dnsfilter/rule_to_regexp.go
+
+
+# all available settings of specific linters
+linters-settings:
+  errcheck:
+    # [deprecated] comma-separated list of pairs of the form pkg:regex
+    # the regex is used to ignore names within pkg. (default "fmt:.*").
+    # see https://github.com/kisielk/errcheck#the-deprecated-method for details
+    ignore: fmt:.*,net:SetReadDeadline,net/http:^Write
+  gocyclo:
+    min-complexity: 20
+  lll:
+    line-length: 200
+
+linters:
+  enable-all: true
+  disable:
+    - interfacer
+    - gocritic
+    - scopelint
+    - gochecknoglobals
+    - gochecknoinits
+    - prealloc
+    - maligned
+    - goconst # disabled until it's possible to configure
+  fast: true
+
+issues:
+  # List of regexps of issue texts to exclude, empty list by default.
+  # But independently from this option we use default exclude patterns,
+  # it can be disabled by `exclude-use-default: false`. To list all
+  # excluded by default patterns execute `golangci-lint run --help`
+  exclude:
+    # structcheck cannot detect usages while they're there
+    - .parentalServer. is unused
+    - .safeBrowsingServer. is unused
+    # errcheck
+    - Error return value of .s.closeConn. is not checked
+    # goconst
+    - string .forcesafesearch.google.com. has 3 occurrences

config.go

@@ -10,7 +10,7 @@ import (
 	"github.com/AdguardTeam/AdGuardHome/dnsfilter"
 	"github.com/AdguardTeam/AdGuardHome/dnsforward"
 	"github.com/hmage/golibs/log"
-	"gopkg.in/yaml.v2"
+	yaml "gopkg.in/yaml.v2"
 )
 
 const (

control.go

@@ -15,7 +15,7 @@ import (
 	"github.com/AdguardTeam/dnsproxy/upstream"
 	"github.com/hmage/golibs/log"
 	"github.com/miekg/dns"
-	"gopkg.in/asaskevich/govalidator.v4"
+	govalidator "gopkg.in/asaskevich/govalidator.v4"
 )
 
 const updatePeriod = time.Minute * 30
@@ -321,27 +321,27 @@ func handleFilteringStatus(w http.ResponseWriter, r *http.Request) {
 }
 
 func handleFilteringAddURL(w http.ResponseWriter, r *http.Request) {
-	filter := filter{}
+	f := filter{}
-	err := json.NewDecoder(r.Body).Decode(&filter)
+	err := json.NewDecoder(r.Body).Decode(&f)
 	if err != nil {
 		httpError(w, http.StatusBadRequest, "Failed to parse request body json: %s", err)
 		return
 	}
 
-	if len(filter.URL) == 0 {
+	if len(f.URL) == 0 {
 		http.Error(w, "URL parameter was not specified", 400)
 		return
 	}
 
-	if valid := govalidator.IsRequestURL(filter.URL); !valid {
+	if valid := govalidator.IsRequestURL(f.URL); !valid {
 		http.Error(w, "URL parameter is not valid request URL", 400)
 		return
 	}
 
 	// Check for duplicates
 	for i := range config.Filters {
-		if config.Filters[i].URL == filter.URL {
+		if config.Filters[i].URL == f.URL {
-			errorText := fmt.Sprintf("Filter URL already added -- %s", filter.URL)
+			errorText := fmt.Sprintf("Filter URL already added -- %s", f.URL)
 			log.Println(errorText)
 			http.Error(w, errorText, http.StatusBadRequest)
 			return
@@ -349,34 +349,34 @@ func handleFilteringAddURL(w http.ResponseWriter, r *http.Request) {
 	}
 
 	// Set necessary properties
-	filter.ID = assignUniqueFilterID()
+	f.ID = assignUniqueFilterID()
-	filter.Enabled = true
+	f.Enabled = true
 
 	// Download the filter contents
-	ok, err := filter.update(true)
+	ok, err := f.update(true)
 	if err != nil {
-		errorText := fmt.Sprintf("Couldn't fetch filter from url %s: %s", filter.URL, err)
+		errorText := fmt.Sprintf("Couldn't fetch filter from url %s: %s", f.URL, err)
 		log.Println(errorText)
 		http.Error(w, errorText, http.StatusBadRequest)
 		return
 	}
-	if filter.RulesCount == 0 {
+	if f.RulesCount == 0 {
-		errorText := fmt.Sprintf("Filter at the url %s has no rules (maybe it points to blank page?)", filter.URL)
+		errorText := fmt.Sprintf("Filter at the url %s has no rules (maybe it points to blank page?)", f.URL)
 		log.Println(errorText)
 		http.Error(w, errorText, http.StatusBadRequest)
 		return
 	}
 	if !ok {
-		errorText := fmt.Sprintf("Filter at the url %s is invalid (maybe it points to blank page?)", filter.URL)
+		errorText := fmt.Sprintf("Filter at the url %s is invalid (maybe it points to blank page?)", f.URL)
 		log.Println(errorText)
 		http.Error(w, errorText, http.StatusBadRequest)
 		return
 	}
 
 	// Save the filter contents
-	err = filter.save()
+	err = f.save()
 	if err != nil {
-		errorText := fmt.Sprintf("Failed to save filter %d due to %s", filter.ID, err)
+		errorText := fmt.Sprintf("Failed to save filter %d due to %s", f.ID, err)
 		log.Println(errorText)
 		http.Error(w, errorText, http.StatusBadRequest)
 		return
@@ -384,7 +384,7 @@ func handleFilteringAddURL(w http.ResponseWriter, r *http.Request) {
 
 	// URL is deemed valid, append it to filters, update config, write new filter file and tell dns to reload it
 	// TODO: since we directly feed filters in-memory, revisit if writing configs is always necessary
-	config.Filters = append(config.Filters, filter)
+	config.Filters = append(config.Filters, f)
 	err = writeAllConfigs()
 	if err != nil {
 		errorText := fmt.Sprintf("Couldn't write config file: %s", err)
@@ -393,9 +393,14 @@ func handleFilteringAddURL(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	reconfigureDNSServer()
+	err = reconfigureDNSServer()
+	if err != nil {
+		errorText := fmt.Sprintf("Couldn't reconfigure the DNS server: %s", err)
+		log.Println(errorText)
+		http.Error(w, errorText, http.StatusInternalServerError)
+	}
 
-	_, err = fmt.Fprintf(w, "OK %d rules\n", filter.RulesCount)
+	_, err = fmt.Fprintf(w, "OK %d rules\n", f.RulesCount)
 	if err != nil {
 		errorText := fmt.Sprintf("Couldn't write body: %s", err)
 		log.Println(errorText)

dhcp.go

@@ -101,9 +101,9 @@ func handleDHCPInterfaces(w http.ResponseWriter, r *http.Request) {
 			MTU:          ifaces[i].MTU,
 			HardwareAddr: ifaces[i].HardwareAddr.String(),
 		}
-		addrs, err := ifaces[i].Addrs()
+		addrs, errAddrs := ifaces[i].Addrs()
-		if err != nil {
+		if errAddrs != nil {
-			httpError(w, http.StatusInternalServerError, "Failed to get addresses for interface %v: %s", ifaces[i].Name, err)
+			httpError(w, http.StatusInternalServerError, "Failed to get addresses for interface %v: %s", ifaces[i].Name, errAddrs)
 			return
 		}
 		for _, addr := range addrs {
@@ -155,7 +155,7 @@ func handleDHCPFindActiveServer(w http.ResponseWriter, r *http.Request) {
 }
 
 func startDHCPServer() error {
-	if config.DHCP.Enabled == false {
+	if !config.DHCP.Enabled {
 		// not enabled, don't do anything
 		return nil
 	}

dhcpd/check_other_dhcp.go

@@ -59,7 +59,7 @@ func CheckIfOtherDHCPServersPresent(ifaceName string) (bool, error) {
 	maxUDPsizeRaw := make([]byte, 2)
 	binary.BigEndian.PutUint16(maxUDPsizeRaw, 1500)
 	leaseTimeRaw := make([]byte, 4)
-	leaseTime := uint32(math.RoundToEven(time.Duration(time.Hour * 24 * 90).Seconds()))
+	leaseTime := uint32(math.RoundToEven((time.Hour * 24 * 90).Seconds()))
 	binary.BigEndian.PutUint32(leaseTimeRaw, leaseTime)
 	options := []dhcp4.Option{
 		{Code: dhcp4.OptionParameterRequestList, Value: requestList},

dhcpd/dhcpd.go

@@ -83,6 +83,7 @@ func (s *Server) Start(config *ServerConfig) error {
 
 	s.leaseStart, err = parseIPv4(s.RangeStart)
 	if err != nil {
+
 		s.closeConn() // in case it was already started
 		return wrapErrPrint(err, "Failed to parse range start address %s", s.RangeStart)
 	}
@@ -178,7 +179,7 @@ func (s *Server) reserveLease(p dhcp4.Packet) (*Lease, error) {
 	}
 	// not assigned a lease, create new one, find IP from LRU
 	log.Tracef("Lease not found for %s: creating new one", hwaddr)
-	ip, err := s.findFreeIP(p, hwaddr)
+	ip, err := s.findFreeIP(hwaddr)
 	if err != nil {
 		return nil, wrapErrPrint(err, "Couldn't find free IP for the lease %s", hwaddr.String())
 	}
@@ -202,7 +203,7 @@ func (s *Server) locateLease(p dhcp4.Packet) *Lease {
 	return nil
 }
 
-func (s *Server) findFreeIP(p dhcp4.Packet, hwaddr net.HardwareAddr) (net.IP, error) {
+func (s *Server) findFreeIP(hwaddr net.HardwareAddr) (net.IP, error) {
 	// if IP pool is nil, lazy initialize it
 	if s.IPpool == nil {
 		s.IPpool = make(map[[4]byte]net.HardwareAddr)
@@ -227,7 +228,7 @@ func (s *Server) findFreeIP(p dhcp4.Packet, hwaddr net.HardwareAddr) (net.IP, er
 
 	if foundIP == nil {
 		// TODO: LRU
-		return nil, fmt.Errorf("Couldn't find free entry in IP pool")
+		return nil, fmt.Errorf("couldn't find free entry in IP pool")
 	}
 
 	s.reserveIP(foundIP, hwaddr)
@@ -281,7 +282,7 @@ func (s *Server) ServeDHCP(p dhcp4.Packet, msgType dhcp4.MessageType, options dh
 	case dhcp4.Request: // Broadcast From Client - I'll take that IP (Also start for renewals)
 		// start/renew a lease -- update lease time
 		// some clients (OSX) just go right ahead and do Request first from previously known IP, if they get NAK, they restart full cycle with Discover then Request
-		return s.handleDHCP4Request(p, msgType, options)
+		return s.handleDHCP4Request(p, options)
 	case dhcp4.Decline: // Broadcast From Client - Sorry I can't use that IP
 		log.Tracef("Got from client: Decline")
 
@@ -306,7 +307,7 @@ func (s *Server) ServeDHCP(p dhcp4.Packet, msgType dhcp4.MessageType, options dh
 	return nil
 }
 
-func (s *Server) handleDHCP4Request(p dhcp4.Packet, msgType dhcp4.MessageType, options dhcp4.Options) dhcp4.Packet {
+func (s *Server) handleDHCP4Request(p dhcp4.Packet, options dhcp4.Options) dhcp4.Packet {
 	log.Tracef("Got from client: Request")
 	if server, ok := options[dhcp4.OptionServerIdentifier]; ok && !net.IP(server).Equal(s.ipnet.IP) {
 		log.Tracef("Request message not for this DHCP server (%v vs %v)", server, s.ipnet.IP)
@@ -315,7 +316,7 @@ func (s *Server) handleDHCP4Request(p dhcp4.Packet, msgType dhcp4.MessageType, o
 
 	reqIP := net.IP(options[dhcp4.OptionRequestedIPAddress])
 	if reqIP == nil {
-		reqIP = net.IP(p.CIAddr())
+		reqIP = p.CIAddr()
 	}
 
 	if reqIP.To4() == nil {

dhcpd/standalone/main.go

@@ -76,9 +76,9 @@ func main() {
 		panic(err)
 	}
 	log.Printf("Now serving DHCP")
-	signal_channel := make(chan os.Signal)
+	signalChannel := make(chan os.Signal)
-	signal.Notify(signal_channel, syscall.SIGINT, syscall.SIGTERM)
+	signal.Notify(signalChannel, syscall.SIGINT, syscall.SIGTERM)
-	<-signal_channel
+	<-signalChannel
 
 }
 

dns.go

@@ -52,7 +52,7 @@ func generateServerConfig() dnsforward.ServerConfig {
 
 func startDNSServer() error {
 	if isRunning() {
-		return fmt.Errorf("Unable to start forwarding DNS server: Already running")
+		return fmt.Errorf("unable to start forwarding DNS server: Already running")
 	}
 
 	newconfig := generateServerConfig()

dnsfilter/dnsfilter_test.go

@@ -869,7 +869,7 @@ func BenchmarkLotsOfRulesLotsOfHosts(b *testing.B) {
 	for n := 0; n < b.N; n++ {
 		havedata := scanner.Scan()
 		if !havedata {
-			hostnames.Seek(0, 0)
+			_, _ = hostnames.Seek(0, 0)
 			scanner = bufio.NewScanner(hostnames)
 			havedata = scanner.Scan()
 		}
@@ -906,7 +906,7 @@ func BenchmarkLotsOfRulesLotsOfHostsParallel(b *testing.B) {
 		for pb.Next() {
 			havedata := scanner.Scan()
 			if !havedata {
-				hostnames.Seek(0, 0)
+				_, _ = hostnames.Seek(0, 0)
 				scanner = bufio.NewScanner(hostnames)
 				havedata = scanner.Scan()
 			}

dnsforward/querylog.go

@@ -108,7 +108,12 @@ func logRequest(question *dns.Msg, answer *dns.Msg, result *dnsfilter.Result, el
 	if len(flushBuffer) > 0 {
 		// write to file
 		// do it in separate goroutine -- we are stalling DNS response this whole time
-		go flushToFile(flushBuffer)
+		go func() {
+			err := flushToFile(flushBuffer)
+			if err != nil {
+				log.Printf("Failed to flush the query log: %s", err)
+			}
+		}()
 	}
 }
 

dnsforward/stats.go

@@ -340,11 +340,11 @@ func HandleStatsHistory(w http.ResponseWriter, r *http.Request) {
 	// check if start and time times are within supported time range
 	timeRange := timeUnit * statsHistoryElements
 	if startTime.Add(timeRange).Before(now) {
-		http.Error(w, "start_time parameter is outside of supported range", 501)
+		http.Error(w, "start_time parameter is outside of supported range", http.StatusBadRequest)
 		return
 	}
 	if endTime.Add(timeRange).Before(now) {
-		http.Error(w, "end_time parameter is outside of supported range", 501)
+		http.Error(w, "end_time parameter is outside of supported range", http.StatusBadRequest)
 		return
 	}
 

helpers.go

@@ -39,7 +39,7 @@ func safeWriteFile(path string, data []byte) error {
 func ensure(method string, handler func(http.ResponseWriter, *http.Request)) func(http.ResponseWriter, *http.Request) {
 	return func(w http.ResponseWriter, r *http.Request) {
 		if r.Method != method {
-			http.Error(w, "This request must be "+method, 405)
+			http.Error(w, "This request must be "+method, http.StatusMethodNotAllowed)
 			return
 		}
 		handler(w, r)

upgrade.go

@@ -7,7 +7,7 @@ import (
 	"path/filepath"
 
 	"github.com/hmage/golibs/log"
-	"gopkg.in/yaml.v2"
+	yaml "gopkg.in/yaml.v2"
 )
 
 const currentSchemaVersion = 2 // used for upgrading from old configs to new config