switch to golangci-lint

.github/workflows/lint.yml

@@ -0,0 +1,25 @@
+name: lint
+
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    branches: [ master ]
+
+jobs:
+  lint:
+    name: lint
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v2
+
+    - uses: golangci/golangci-lint-action@v2
+      with:
+        version: v1.33
+        args: >
+          --disable=errcheck
+          --enable=gofmt
+          --enable=golint
+          --enable=misspell

Makefile

@@ -10,7 +10,8 @@ help:
 	@echo ""
 	@echo "  mod-tidy       run go mod tidy"
 	@echo "  format         format source files"
-	@echo "  test           run available tests"
+	@echo "  test           run tests"
+	@echo "  lint           run linter"
 	@echo "  run ARGS=args  run app"
 	@echo "  release        build release assets"
 	@echo "  dockerhub      build and push docker hub images"
@@ -51,6 +52,15 @@ test-nodocker:
 	$(eval export CGO_ENABLED=0)
 	go build -o /dev/null .
 
+lint:
+	docker run --rm -v $(PWD):/app -w /app \
+	golangci/golangci-lint:v1.33.0 \
+	golangci-lint run -v \
+	--disable=errcheck \
+	--enable=gofmt \
+	--enable=golint \
+	--enable=misspell
+
 define DOCKERFILE_RUN
 FROM amd64/$(BASE_IMAGE)
 WORKDIR /s

README.md

@@ -2,7 +2,7 @@
 # landiscover
 
 [![Test](https://github.com/aler9/landiscover/workflows/test/badge.svg)](https://github.com/aler9/landiscover/actions)
-[![Go Report Card](https://goreportcard.com/badge/github.com/aler9/landiscover)](https://goreportcard.com/report/github.com/aler9/landiscover)
+[![Lint](https://github.com/aler9/landiscover/workflows/lint/badge.svg)](https://github.com/aler9/landiscover/actions)
 [![Docker Hub](https://img.shields.io/badge/docker-aler9%2Flandiscover-blue)](https://hub.docker.com/r/aler9/landiscover)
 
 ![](README.gif)

layer-mdns.go

@@ -11,13 +11,13 @@ import (
 
 const mdnsPort = 5353
 
-var reMdnsQueryLocal = regexp.MustCompile("^([0-9]{1,3})\\.([0-9]{1,3})\\.([0-9]{1,3})\\.([0-9]{1,3})\\.in-addr\\.arpa$")
+var reMdnsQueryLocal = regexp.MustCompile(`^([0-9]{1,3})\.([0-9]{1,3})\.([0-9]{1,3})\.([0-9]{1,3})\.in-addr\.arpa$`)
 
 var layerTypeMdns gopacket.LayerType
 
 type layerMdns struct {
 	layers.BaseLayer
-	TransactionId   uint16
+	TransactionID   uint16
 	IsResponse      bool
 	Opcode          uint8
 	Questions       []mdnsQuestion
@@ -81,7 +81,7 @@ func (l *layerMdns) Payload() []byte {
 func (l *layerMdns) DecodeFromBytes(data []byte, df gopacket.DecodeFeedback) error {
 	l.BaseLayer = layers.BaseLayer{Contents: data[:]}
 
-	l.TransactionId = binary.BigEndian.Uint16(data[0:2])
+	l.TransactionID = binary.BigEndian.Uint16(data[0:2])
 	l.IsResponse = (data[3] >> 7) == 0x01
 	l.Opcode = uint8((data[3] >> 3) & 0x0F)
 	questionCount := binary.BigEndian.Uint16(data[4:6])
@@ -135,7 +135,7 @@ func (l *layerMdns) SerializeTo(b gopacket.SerializeBuffer, opts gopacket.Serial
 		panic(err)
 	}
 
-	binary.BigEndian.PutUint16(data[0:2], l.TransactionId)
+	binary.BigEndian.PutUint16(data[0:2], l.TransactionID)
 	if l.IsResponse {
 		data[3] |= 0x01 << 7
 	}

layer-nbns.go

@@ -15,7 +15,7 @@ var layerTypeNbns gopacket.LayerType
 
 type layerNbns struct {
 	layers.BaseLayer
-	TransactionId   uint16
+	TransactionID   uint16
 	IsResponse      bool
 	Opcode          uint8
 	Truncated       bool
@@ -92,7 +92,7 @@ func (l *layerNbns) DecodeFromBytes(data []byte, df gopacket.DecodeFeedback) err
 		return fmt.Errorf("invalid packet")
 	}
 
-	l.TransactionId = binary.BigEndian.Uint16(data[0:2])
+	l.TransactionID = binary.BigEndian.Uint16(data[0:2])
 	l.IsResponse = (data[3] >> 7) == 0x01
 	l.Opcode = uint8((data[3] >> 3) & 0x0F)
 	l.Truncated = (data[3] >> 1) == 0x01
@@ -153,7 +153,7 @@ func (l *layerNbns) SerializeTo(b gopacket.SerializeBuffer, opts gopacket.Serial
 		panic(err)
 	}
 
-	binary.BigEndian.PutUint16(data[0:2], l.TransactionId)
+	binary.BigEndian.PutUint16(data[0:2], l.TransactionID)
 	if l.IsResponse {
 		data[3] |= 0x01 << 7
 	}

main.go

@@ -36,7 +36,7 @@ type node struct {
 
 type arpReq struct {
 	srcMac net.HardwareAddr
-	srcIp  net.IP
+	srcIP  net.IP
 }
 
 type dnsReq struct {
@@ -46,13 +46,13 @@ type dnsReq struct {
 
 type mdnsReq struct {
 	srcMac     net.HardwareAddr
-	srcIp      net.IP
+	srcIP      net.IP
 	domainName string
 }
 
 type nbnsReq struct {
 	srcMac net.HardwareAddr
-	srcIp  net.IP
+	srcIP  net.IP
 	name   string
 }
 
@@ -64,7 +64,7 @@ type uiGetDataReq struct {
 type program struct {
 	passiveMode bool
 	intf        *net.Interface
-	ownIp       net.IP
+	ownIP       net.IP
 	ls          *listener
 	ma          *methodArp
 	mm          *methodMdns
@@ -123,7 +123,7 @@ func newProgram() error {
 		return err
 	}
 
-	ownIp, err := func() (net.IP, error) {
+	ownIP, err := func() (net.IP, error) {
 		addrs, err := intf.Addrs()
 		if err != nil {
 			return nil, err
@@ -148,7 +148,7 @@ func newProgram() error {
 	p := &program{
 		passiveMode: *argPassiveMode,
 		intf:        intf,
-		ownIp:       ownIp,
+		ownIP:       ownIP,
 		arp:         make(chan arpReq),
 		dns:         make(chan dnsReq),
 		mdns:        make(chan mdnsReq),
@@ -177,7 +177,7 @@ func newProgram() error {
 		return err
 	}
 
-	err = newUi(p)
+	err = newUI(p)
 	if err != nil {
 		return err
 	}
@@ -200,19 +200,19 @@ outer:
 	for {
 		select {
 		case req := <-p.arp:
-			key := newNodeKey(req.srcMac, req.srcIp)
+			key := newNodeKey(req.srcMac, req.srcIP)
 
 			if _, ok := nodes[key]; !ok {
 				nodes[key] = &node{
 					lastSeen: time.Now(),
 					mac:      req.srcMac,
-					ip:       req.srcIp,
+					ip:       req.srcIP,
 				}
 
-				if p.passiveMode == false {
-					go p.dnsRequest(key, req.srcIp)
-					go p.mm.request(req.srcIp)
-					go p.mn.request(req.srcIp)
+				if !p.passiveMode {
+					go p.dnsRequest(key, req.srcIP)
+					go p.mm.request(req.srcIP)
+					go p.mn.request(req.srcIP)
 				}
 
 				// update last seen
@@ -224,13 +224,13 @@ outer:
 			nodes[req.key].dns = req.dns
 
 		case req := <-p.mdns:
-			key := newNodeKey(req.srcMac, req.srcIp)
+			key := newNodeKey(req.srcMac, req.srcIP)
 
 			if _, ok := nodes[key]; !ok {
 				nodes[key] = &node{
 					lastSeen: time.Now(),
 					mac:      req.srcMac,
-					ip:       req.srcIp,
+					ip:       req.srcIP,
 				}
 			}
 
@@ -240,13 +240,13 @@ outer:
 			}
 
 		case req := <-p.nbns:
-			key := newNodeKey(req.srcMac, req.srcIp)
+			key := newNodeKey(req.srcMac, req.srcIP)
 
 			if _, has := nodes[key]; !has {
 				nodes[key] = &node{
 					lastSeen: time.Now(),
 					mac:      req.srcMac,
-					ip:       req.srcIp,
+					ip:       req.srcIP,
 				}
 			}
 

method-arp.go

@@ -33,7 +33,7 @@ func newMethodArp(p *program) error {
 func (ma *methodArp) run() {
 	go ma.runListener()
 
-	if ma.p.passiveMode == false {
+	if !ma.p.passiveMode {
 		go ma.runPeriodicRequests()
 	}
 }
@@ -60,21 +60,21 @@ func (ma *methodArp) runListener() {
 			return
 		}
 
-		if bytes.Equal(arp.SourceProtAddress, []byte{0, 0, 0, 0}) == true {
+		if bytes.Equal(arp.SourceProtAddress, []byte{0, 0, 0, 0}) {
 			return
 		}
 
 		srcMac := copyMac(arp.SourceHwAddress)
-		srcIp := copyIp(arp.SourceProtAddress)
+		srcIP := copyIP(arp.SourceProtAddress)
 
 		// ethernet mac and arp mac must correspond
-		if bytes.Equal(arp.SourceHwAddress, eth.SrcMAC) == false {
+		if !bytes.Equal(arp.SourceHwAddress, eth.SrcMAC) {
 			return
 		}
 
 		ma.p.arp <- arpReq{
 			srcMac: srcMac,
-			srcIp:  srcIp,
+			srcIP:  srcIP,
 		}
 	}
 
@@ -97,7 +97,7 @@ func (ma *methodArp) runPeriodicRequests() {
 		ProtAddressSize:   4,
 		Operation:         layers.ARPRequest,
 		SourceHwAddress:   ma.p.intf.HardwareAddr,
-		SourceProtAddress: ma.p.ownIp,
+		SourceProtAddress: ma.p.ownIP,
 		DstHwAddress:      []byte{0, 0, 0, 0, 0, 0},
 	}
 
@@ -108,7 +108,7 @@ func (ma *methodArp) runPeriodicRequests() {
 	}
 
 	for {
-		for _, dstAddr := range randAvailableIps(ma.p.ownIp) {
+		for _, dstAddr := range randAvailableIps(ma.p.ownIP) {
 			arp.DstProtAddress = dstAddr
 			if err := gopacket.SerializeLayers(buf, opts, &eth, &arp); err != nil {
 				panic(err)

method-dns.go

@@ -4,8 +4,8 @@ import (
 	"net"
 )
 
-func (p *program) dnsRequest(key nodeKey, destIp net.IP) {
-	names, err := net.LookupAddr(destIp.String())
+func (p *program) dnsRequest(key nodeKey, destIP net.IP) {
+	names, err := net.LookupAddr(destIP.String())
 	if err != nil {
 		return
 	}

method-mdns.go

@@ -1,7 +1,6 @@
 package main
 
 import (
-	"bytes"
 	"fmt"
 	"net"
 	"strings"
@@ -34,7 +33,7 @@ func newMethodMdns(p *program) error {
 func (mm *methodMdns) run() {
 	go mm.runListener()
 
-	if mm.p.passiveMode == false {
+	if !mm.p.passiveMode {
 		// continuously poll mdns in order to detect changes or skipped hosts
 		go mm.runPeriodicRequests()
 	}
@@ -67,7 +66,7 @@ func (mm *methodMdns) runListener() {
 		}
 
 		srcMac := copyMac(eth.SrcMAC)
-		srcIp := copyIp(ip.SrcIP)
+		srcIP := copyIP(ip.SrcIP)
 
 		domainName := func() string {
 			for _, a := range mdns.Answers {
@@ -82,8 +81,8 @@ func (mm *methodMdns) runListener() {
 				}
 
 				// accept only if mdns ip matches with sender ip
-				mdnsIp := net.ParseIP(fmt.Sprintf("%s.%s.%s.%s", m[4], m[3], m[2], m[1])).To4()
-				if bytes.Equal(mdnsIp, srcIp) == false {
+				mdnsIP := net.ParseIP(fmt.Sprintf("%s.%s.%s.%s", m[4], m[3], m[2], m[1])).To4()
+				if !mdnsIP.Equal(srcIP) {
 					continue
 				}
 
@@ -99,7 +98,7 @@ func (mm *methodMdns) runListener() {
 
 		mm.p.mdns <- mdnsReq{
 			srcMac:     srcMac,
-			srcIp:      srcIp,
+			srcIP:      srcIP,
 			domainName: domainName,
 		}
 	}
@@ -110,7 +109,7 @@ func (mm *methodMdns) runListener() {
 	}
 }
 
-func (mm *methodMdns) request(destIp net.IP) {
+func (mm *methodMdns) request(destIP net.IP) {
 	mac, _ := net.ParseMAC("01:00:5e:00:00:fb")
 	eth := layers.Ethernet{
 		SrcMAC:       mm.p.intf.HardwareAddr,
@@ -122,7 +121,7 @@ func (mm *methodMdns) request(destIp net.IP) {
 		TTL:      255,
 		Id:       randUint16(),
 		Protocol: layers.IPProtocolUDP,
-		SrcIP:    mm.p.ownIp,
+		SrcIP:    mm.p.ownIP,
 		DstIP:    net.ParseIP("224.0.0.251"), // TODO: provare unicast
 	}
 	udp := layers.UDP{
@@ -131,10 +130,10 @@ func (mm *methodMdns) request(destIp net.IP) {
 	}
 	udp.SetNetworkLayerForChecksum(&ip)
 	mdns := layerMdns{
-		TransactionId: 0,
+		TransactionID: 0,
 		Questions: []mdnsQuestion{
 			{
-				Query: fmt.Sprintf("%d.%d.%d.%d.in-addr.arpa", destIp[3], destIp[2], destIp[1], destIp[0]),
+				Query: fmt.Sprintf("%d.%d.%d.%d.in-addr.arpa", destIP[3], destIP[2], destIP[1], destIP[0]),
 				Type:  0x0C, // domain pointer
 				Class: 1,    // IN
 			},
@@ -158,7 +157,7 @@ func (mm *methodMdns) request(destIp net.IP) {
 
 func (mm *methodMdns) runPeriodicRequests() {
 	for {
-		for _, dstAddr := range randAvailableIps(mm.p.ownIp) {
+		for _, dstAddr := range randAvailableIps(mm.p.ownIP) {
 			mm.request(dstAddr)
 			time.Sleep(mdnsPeriod) // about 1 minute for a full scan
 		}