*: add support for socket options

pkg/transport/listener.go

@@ -15,6 +15,7 @@
 package transport
 
 import (
+	"context"
 	"crypto/ecdsa"
 	"crypto/elliptic"
 	"crypto/rand"
@@ -39,18 +40,66 @@ import (
 
 // NewListener creates a new listner.
 func NewListener(addr, scheme string, tlsinfo *TLSInfo) (l net.Listener, err error) {
-	if l, err = newListener(addr, scheme); err != nil {
-		return nil, err
-	}
-	return wrapTLS(scheme, tlsinfo, l)
+	return newListener(addr, scheme, WithTLSInfo(tlsinfo))
+}
+
+// NewListenerWithOpts creates a new listener which accpets listener options.
+func NewListenerWithOpts(addr, scheme string, opts ...ListenerOption) (net.Listener, error) {
+	return newListener(addr, scheme, opts...)
 }
 
-func newListener(addr string, scheme string) (net.Listener, error) {
+func newListener(addr, scheme string, opts ...ListenerOption) (net.Listener, error) {
 	if scheme == "unix" || scheme == "unixs" {
 		// unix sockets via unix://laddr
 		return NewUnixListener(addr)
 	}
-	return net.Listen("tcp", addr)
+
+	lnOpts := newListenOpts(opts...)
+
+	switch {
+	case lnOpts.IsSocketOpts():
+		// new ListenConfig with socket options.
+		config, err := newListenConfig(lnOpts.socketOpts)
+		if err != nil {
+			return nil, err
+		}
+		lnOpts.ListenConfig = config
+		// check for timeout
+		fallthrough
+	case lnOpts.IsTimeout(), lnOpts.IsSocketOpts():
+		// timeout listener with socket options.
+		ln, err := lnOpts.ListenConfig.Listen(context.TODO(), "tcp", addr)
+		if err != nil {
+			return nil, err
+		}
+		lnOpts.Listener = &rwTimeoutListener{
+			Listener:     ln,
+			readTimeout:  lnOpts.readTimeout,
+			writeTimeout: lnOpts.writeTimeout,
+		}
+	case lnOpts.IsTimeout():
+		ln, err := net.Listen("tcp", addr)
+		if err != nil {
+			return nil, err
+		}
+		lnOpts.Listener = &rwTimeoutListener{
+			Listener:     ln,
+			readTimeout:  lnOpts.readTimeout,
+			writeTimeout: lnOpts.writeTimeout,
+		}
+	default:
+		ln, err := net.Listen("tcp", addr)
+		if err != nil {
+			return nil, err
+		}
+		lnOpts.Listener = ln
+	}
+
+	//  only skip if not passing TLSInfo
+	if lnOpts.skipTLSInfoCheck && !lnOpts.IsTLS() {
+		return lnOpts.Listener, nil
+	}
+	return wrapTLS(scheme, lnOpts.tlsInfo, lnOpts.Listener)
 }
 
 func wrapTLS(scheme string, tlsinfo *TLSInfo, l net.Listener) (net.Listener, error) {
@@ -63,6 +112,17 @@ func wrapTLS(scheme string, tlsinfo *TLSInfo, l net.Listener) (net.Listener, err
 	return newTLSListener(l, tlsinfo, checkSAN)
 }
 
+func newListenConfig(sopts *SocketOpts) (net.ListenConfig, error) {
+	lc := net.ListenConfig{}
+	if sopts != nil {
+		ctls := getControls(sopts)
+		if len(ctls) > 0 {
+			lc.Control = ctls.Control
+		}
+	}
+	return lc, nil
+}
+
 type TLSInfo struct {
 	CertFile            string
 	KeyFile             string

pkg/transport/listener_opts.go

@@ -0,0 +1,76 @@
+package transport
+
+import (
+	"net"
+	"time"
+)
+
+type ListenerOptions struct {
+	Listener     net.Listener
+	ListenConfig net.ListenConfig
+
+	socketOpts       *SocketOpts
+	tlsInfo          *TLSInfo
+	skipTLSInfoCheck bool
+	writeTimeout     time.Duration
+	readTimeout      time.Duration
+}
+
+func newListenOpts(opts ...ListenerOption) *ListenerOptions {
+	lnOpts := &ListenerOptions{}
+	lnOpts.applyOpts(opts)
+	return lnOpts
+}
+
+func (lo *ListenerOptions) applyOpts(opts []ListenerOption) {
+	for _, opt := range opts {
+		opt(lo)
+	}
+}
+
+// IsTimeout returns true if the listener has a read/write timeout defined.
+func (lo *ListenerOptions) IsTimeout() bool { return lo.readTimeout != 0 || lo.writeTimeout != 0 }
+
+// IsSocketOpts returns true if the listener options includes socket options.
+func (lo *ListenerOptions) IsSocketOpts() bool {
+	if lo.socketOpts == nil {
+		return false
+	}
+	return lo.socketOpts.ReusePort == true || lo.socketOpts.ReuseAddress == true
+}
+
+// IsTLS returns true if listner options includes TLSInfo.
+func (lo *ListenerOptions) IsTLS() bool {
+	if lo.tlsInfo == nil {
+		return false
+	}
+	return lo.tlsInfo.Empty() == false
+}
+
+// ListenerOption are options which can be applied to the listener.
+type ListenerOption func(*ListenerOptions)
+
+// WithTimeout allows for a read or write timeout to be applied to the listener.
+func WithTimeout(read, write time.Duration) ListenerOption {
+	return func(lo *ListenerOptions) {
+		lo.writeTimeout = write
+		lo.readTimeout = read
+	}
+}
+
+// WithSocketOpts defines socket options that will be applied to the listener.
+func WithSocketOpts(s *SocketOpts) ListenerOption {
+	return func(lo *ListenerOptions) { lo.socketOpts = s }
+}
+
+// WithTLSInfo adds TLS credentials to the listener.
+func WithTLSInfo(t *TLSInfo) ListenerOption {
+	return func(lo *ListenerOptions) { lo.tlsInfo = t }
+}
+
+// WithSkipTLSInfoCheck when true a transport can be created with an https scheme
+// without passing TLSInfo, circumventing not presented error. Skipping this check
+// also requires that TLSInfo is not passed.
+func WithSkipTLSInfoCheck(skip bool) ListenerOption {
+	return func(lo *ListenerOptions) { lo.skipTLSInfoCheck = skip }
+}

pkg/transport/listener_test.go

@@ -61,6 +61,161 @@ func TestNewListenerTLSInfo(t *testing.T) {
 	testNewListenerTLSInfoAccept(t, *tlsInfo)
 }
 
+func TestNewListenerWithOpts(t *testing.T) {
+	tlsInfo, del, err := createSelfCert()
+	if err != nil {
+		t.Fatalf("unable to create cert: %v", err)
+	}
+	defer del()
+
+	tests := map[string]struct {
+		opts        []ListenerOption
+		scheme      string
+		expectedErr bool
+	}{
+		"https scheme no TLSInfo": {
+			opts:        []ListenerOption{},
+			expectedErr: true,
+			scheme:      "https",
+		},
+		"https scheme no TLSInfo with skip check": {
+			opts:        []ListenerOption{WithSkipTLSInfoCheck(true)},
+			expectedErr: false,
+			scheme:      "https",
+		},
+		"https scheme empty TLSInfo with skip check": {
+			opts: []ListenerOption{
+				WithSkipTLSInfoCheck(true),
+				WithTLSInfo(&TLSInfo{}),
+			},
+			expectedErr: false,
+			scheme:      "https",
+		},
+		"https scheme empty TLSInfo no skip check": {
+			opts: []ListenerOption{
+				WithTLSInfo(&TLSInfo{}),
+			},
+			expectedErr: true,
+			scheme:      "https",
+		},
+		"https scheme with TLSInfo and skip check": {
+			opts: []ListenerOption{
+				WithSkipTLSInfoCheck(true),
+				WithTLSInfo(tlsInfo),
+			},
+			expectedErr: false,
+			scheme:      "https",
+		},
+	}
+	for testName, test := range tests {
+		t.Run(testName, func(t *testing.T) {
+			ln, err := NewListenerWithOpts("127.0.0.1:0", test.scheme, test.opts...)
+			if ln != nil {
+				defer ln.Close()
+			}
+			if test.expectedErr && err == nil {
+				t.Fatalf("expected error")
+			}
+			if !test.expectedErr && err != nil {
+				t.Fatalf("unexpected error: %v", err)
+			}
+		})
+	}
+}
+
+func TestNewListenerWithSocketOpts(t *testing.T) {
+	tlsInfo, del, err := createSelfCert()
+	if err != nil {
+		t.Fatalf("unable to create cert: %v", err)
+	}
+	defer del()
+
+	tests := map[string]struct {
+		opts        []ListenerOption
+		scheme      string
+		expectedErr bool
+	}{
+		"nil socketopts": {
+			opts:        []ListenerOption{WithSocketOpts(nil)},
+			expectedErr: true,
+			scheme:      "http",
+		},
+		"empty socketopts": {
+			opts:        []ListenerOption{WithSocketOpts(&SocketOpts{})},
+			expectedErr: true,
+			scheme:      "http",
+		},
+
+		"reuse address": {
+			opts:        []ListenerOption{WithSocketOpts(&SocketOpts{ReuseAddress: true})},
+			scheme:      "http",
+			expectedErr: true,
+		},
+		"reuse address with TLS": {
+			opts: []ListenerOption{
+				WithSocketOpts(&SocketOpts{ReuseAddress: true}),
+				WithTLSInfo(tlsInfo),
+			},
+			scheme:      "https",
+			expectedErr: true,
+		},
+		"reuse address and port": {
+			opts:        []ListenerOption{WithSocketOpts(&SocketOpts{ReuseAddress: true, ReusePort: true})},
+			scheme:      "http",
+			expectedErr: false,
+		},
+		"reuse address and port with TLS": {
+			opts: []ListenerOption{
+				WithSocketOpts(&SocketOpts{ReuseAddress: true, ReusePort: true}),
+				WithTLSInfo(tlsInfo),
+			},
+			scheme:      "https",
+			expectedErr: false,
+		},
+		"reuse port with TLS and timeout": {
+			opts: []ListenerOption{
+				WithSocketOpts(&SocketOpts{ReusePort: true}),
+				WithTLSInfo(tlsInfo),
+				WithTimeout(5*time.Second, 5*time.Second),
+			},
+			scheme:      "https",
+			expectedErr: false,
+		},
+		"reuse port with https scheme and no TLSInfo skip check": {
+			opts: []ListenerOption{
+				WithSocketOpts(&SocketOpts{ReusePort: true}),
+				WithSkipTLSInfoCheck(true),
+			},
+			scheme:      "https",
+			expectedErr: false,
+		},
+		"reuse port": {
+			opts:        []ListenerOption{WithSocketOpts(&SocketOpts{ReusePort: true})},
+			scheme:      "http",
+			expectedErr: false,
+		},
+	}
+	for testName, test := range tests {
+		t.Run(testName, func(t *testing.T) {
+			ln, err := NewListenerWithOpts("127.0.0.1:0", test.scheme, test.opts...)
+			if err != nil {
+				t.Fatalf("unexpected NewListenerWithSocketOpts error: %v", err)
+			}
+			defer ln.Close()
+			ln2, err := NewListenerWithOpts(ln.Addr().String(), test.scheme, test.opts...)
+			if ln2 != nil {
+				ln2.Close()
+			}
+			if test.expectedErr && err == nil {
+				t.Fatalf("expected error")
+			}
+			if !test.expectedErr && err != nil {
+				t.Fatalf("unexpected error: %v", err)
+			}
+		})
+	}
+}
+
 func testNewListenerTLSInfoAccept(t *testing.T, tlsInfo TLSInfo) {
 	ln, err := NewListener("127.0.0.1:0", "https", &tlsInfo)
 	if err != nil {
@@ -401,3 +556,21 @@ func TestIsClosedConnError(t *testing.T) {
 		t.Fatalf("expect true, got false (%v)", err)
 	}
 }
+
+func TestSocktOptsEmpty(t *testing.T) {
+	tests := []struct {
+		sopts SocketOpts
+		want  bool
+	}{
+		{SocketOpts{}, true},
+		{SocketOpts{ReuseAddress: true, ReusePort: false}, false},
+		{SocketOpts{ReusePort: true}, false},
+	}
+
+	for i, tt := range tests {
+		got := tt.sopts.Empty()
+		if tt.want != got {
+			t.Errorf("#%d: result of Empty() incorrect: want=%t got=%t", i, tt.want, got)
+		}
+	}
+}