build: Enable gometalinter "unused" check

build.go

@@ -299,6 +299,7 @@ func runCommand(cmd string, target target) {
 			ok = gometalinter("structcheck", dirs) && ok
 			ok = gometalinter("varcheck", dirs) && ok
 			ok = gometalinter("ineffassign", dirs) && ok
+			ok = gometalinter("unused", dirs) && ok
 			if !ok {
 				os.Exit(1)
 			}
@@ -369,6 +370,7 @@ func setup() {
 		"github.com/tsenart/deadcode",
 		"golang.org/x/net/html",
 		"golang.org/x/tools/cmd/cover",
+		"honnef.co/go/unused/cmd/unused",
 	}
 	for _, pkg := range packages {
 		fmt.Println(pkg)

cmd/strelaysrv/main.go

@@ -54,7 +54,6 @@ func init() {
 var (
 	listen string
 	debug  bool
-	proto  string
 
 	sessionAddress []byte
 	sessionPort    uint16

lib/model/model.go

@@ -1070,20 +1070,6 @@ func (m *Model) Closed(conn protocol.Connection, err error) {
 	close(closed)
 }
 
-// close will close the underlying connection for a given device
-func (m *Model) close(device protocol.DeviceID) {
-	m.pmut.Lock()
-	conn, ok := m.conn[device]
-	m.pmut.Unlock()
-
-	if !ok {
-		// There is no connection to close
-		return
-	}
-
-	closeRawConn(conn)
-}
-
 // Request returns the specified data segment by reading it from local disk.
 // Implements the protocol.Model interface.
 func (m *Model) Request(deviceID protocol.DeviceID, folder, name string, offset int64, hash []byte, fromTemporary bool, buf []byte) error {

lib/protocol/protocol.go

@@ -21,8 +21,6 @@ const (
 
 	// MaxMessageLen is the largest message size allowed on the wire. (500 MB)
 	MaxMessageLen = 500 * 1000 * 1000
-
-	hdrSize = 6
 )
 
 const (