Implement linter suggestions

Author: blechschmidt

fwd.go

@@ -155,7 +155,7 @@ func LocalForward(state *State, s *stack.Stack, conn KaConn, targetAddr net.Addr
 		// connection had routable IP (unlike
 		// 127.0.0.1)... well... spoof it! The client might find it
 		// useful who launched the connection in the first place.
-		if proxyProtocol == false {
+		if !proxyProtocol {
 			srcIP = conn.RemoteAddr()
 		} else {
 			ppPrefix = "PP "
@@ -251,5 +251,4 @@ pperror:
 			err)
 	}
 	conn.Close()
-	return
 }

kacon.go

@@ -1,11 +1,12 @@
 package main
 
 import (
-	"golang.org/x/sys/unix"
 	"net"
 	"sync"
 	"syscall"
 	"time"
+
+	"golang.org/x/sys/unix"
 )
 
 type KaConn interface {
@@ -92,7 +93,7 @@ func (c *KaUDPConn) Read(buf []byte) (int, error) {
 	c.Conn.SetReadDeadline(t)
 
 	n, err := c.Conn.Read(buf)
-	if ne, ok := err.(net.Error); ok == true && ne.Timeout() {
+	if ne, ok := err.(net.Error); ok && ne.Timeout() {
 		// On Keepalive raise special error
 		return 0, &UDPKeepAliveError{err}
 	} else {

main.go

@@ -353,12 +353,10 @@ func Main(programName string, args []string) int {
 	}
 
 	for {
-		select {
-		case sig := <-sigCh:
-			signal.Reset(sig)
-			fmt.Fprintf(os.Stderr, "[-] #%d Slirpnetstack closing\n", pid)
-			goto stop
-		}
+		sig := <-sigCh
+		signal.Reset(sig)
+		fmt.Fprintf(os.Stderr, "[-] #%d Slirpnetstack closing\n", pid)
+		goto stop
 	}
 stop:
 	// TODO: define semantics of graceful close on signal

net.go

@@ -100,7 +100,7 @@ func ParseDefAddress(ipS string, portS string) (_da *defAddress, _err error) {
 func (da *defAddress) Retrieve() *tcpip.FullAddress {
 	da.Lock()
 	defer da.Unlock()
-	if da.label == "" || time.Now().Sub(da.fetched) <= dnsTTL {
+	if da.label == "" || time.Since(da.fetched) <= dnsTTL {
 		return &da.static
 	}
 	da.fetched = time.Now()
@@ -165,7 +165,7 @@ func simpleLookupHost(resolver *net.Resolver, label string) (net.IP, error) {
 		return nil, err
 	}
 	if len(addrs) < 1 {
-		return nil, fmt.Errorf("Empty dns reponse for %q", label)
+		return nil, fmt.Errorf("empty dns reponse for %q", label)
 	}
 
 	// prefer IPv4. No real reason.
@@ -178,7 +178,7 @@ func simpleLookupHost(resolver *net.Resolver, label string) (net.IP, error) {
 
 	ip := netParseIP(addrs[0])
 	if ip == nil {
-		return nil, fmt.Errorf("Empty dns reponse for %q", label)
+		return nil, fmt.Errorf("empty dns reponse for %q", label)
 	}
 	return ip, nil
 }
@@ -189,7 +189,7 @@ func FullResolve(label string) (net.IP, uint16, error) {
 	if len(p) == 2 {
 		srvQuery, dnsSrv := p[0], p[1]
 		if !strings.HasPrefix(dnsSrv, "srv-") {
-			return nil, 0, fmt.Errorf("Unknown dns type %q", dnsSrv)
+			return nil, 0, fmt.Errorf("unknown dns type %q", dnsSrv)
 		}
 
 		dnsSrvAddr := dnsSrv[4:]
@@ -207,16 +207,14 @@ func FullResolve(label string) (net.IP, uint16, error) {
 		}
 		_, srvAddrs, err := r.LookupSRV(context.Background(), "", "", srvQuery)
 		if err != nil || len(srvAddrs) == 0 {
-			return nil, 0, fmt.Errorf("Failed to lookup SRV %q on %q", srvQuery, dnsSrvAddr)
+			return nil, 0, fmt.Errorf("failed to lookup SRV %q on %q", srvQuery, dnsSrvAddr)
 		}
 
 		// For effective resolution, allowing to utilize
 		// /etc/hosts, trim the trailing dot if present.
 		serviceLabel := srvAddrs[0].Target
 		servicePort := srvAddrs[0].Port
-		if strings.HasSuffix(serviceLabel, ".") {
-			serviceLabel = serviceLabel[:len(serviceLabel)-1]
-		}
+		serviceLabel = strings.TrimSuffix(serviceLabel, ".")
 
 		ip, err := simpleLookupHost(r, serviceLabel)
 		if err == nil && ip != nil {

proxy.go

@@ -154,7 +154,7 @@ func connSplice(local KaConn, remote KaConn, sppHeader []byte) ProxyError {
 	proxyOneFlow(remote, local, &pe.RemoteRead,
 		&pe.LocalWrite, doneCh, 1, sppHeader)
 	first := <-doneCh
-	_ = <-doneCh
+	<-doneCh
 	switch {
 	case first == 0 && pe.LocalRead != nil:
 		pe.First = 0

routing.go

@@ -54,7 +54,7 @@ func UdpRoutingHandler(s *stack.Stack, state *State) func(*udp.ForwarderRequest)
 		}
 
 		rf, ok := state.remoteUdpFwd[loc.String()]
-		if ok == false {
+		if !ok {
 			if block := FirewallRoutingBlock(state, loc); block {
 				ep.Close()
 				return
@@ -88,7 +88,7 @@ func TcpRoutingHandler(state *State) func(*tcp.ForwarderRequest) {
 		}
 
 		rf, ok := state.remoteTcpFwd[loc.String()]
-		if ok == false {
+		if !ok {
 			if block := FirewallRoutingBlock(state, loc); block {
 				// In theory we could pass a bit of
 				// data to the guest here. Like:

stack.go

@@ -126,7 +126,7 @@ func NewStack(rcvBufferSize, sndBufferSize int) *stack.Stack {
 	return s
 }
 
-func createLinkEP(s *stack.Stack, tunFd int, tapMode bool, macAddress net.HardwareAddr, tapMtu uint32) (stack.LinkEndpoint, error) {
+func createLinkEP(_ *stack.Stack, tunFd int, tapMode bool, macAddress net.HardwareAddr, tapMtu uint32) (stack.LinkEndpoint, error) {
 	parms := fdbased.Options{FDs: []int{tunFd},
 		MTU:               tapMtu,
 		RXChecksumOffload: true,
@@ -227,9 +227,7 @@ func GonetDialTCP(s *stack.Stack, laddr, raddr *tcpip.FullAddress, network tcpip
 
 	err = ep.Connect(*raddr)
 	if _, ok := err.(*tcpip.ErrConnectStarted); ok {
-		select {
-		case <-notifyCh:
-		}
+		<-notifyCh
 
 		err = ep.LastError()
 	}