Add read timeout

client.go

@@ -18,6 +18,10 @@ type Client struct {
 	// retry).
 	Retry time.Duration
 
+	// Interval on which the response is timed out (zero or negative value means no
+	// timeout).
+	ResponseTimeout time.Duration
+
 	// MaxPacketErrors controls how many packet parsing and validation errors
 	// the client will ignore before returning the error from Exchange.
 	//
@@ -32,6 +36,7 @@ type Client struct {
 // DefaultClient is the RADIUS client used by the Exchange function.
 var DefaultClient = &Client{
 	Retry:           time.Second,
+	ResponseTimeout: 0 * time.Second,
 	MaxPacketErrors: 10,
 }
 
@@ -95,6 +100,12 @@ func (c *Client) Exchange(ctx context.Context, packet *Packet, addr string) (*Pa
 	}()
 
 	var packetErrorCount int
+	if c.ResponseTimeout > 0 {
+		err = conn.SetReadDeadline(time.Now().Add(c.ResponseTimeout))
+		if err != nil {
+			return nil, err
+		}
+	}
 
 	var incoming [MaxPacketLength]byte
 	for {

client_test.go

@@ -2,6 +2,7 @@ package radius
 
 import (
 	"context"
+	"net"
 	"strings"
 	"sync/atomic"
 	"testing"
@@ -160,3 +161,32 @@ func TestClient_Exchange_nilContext(t *testing.T) {
 	//lint:ignore SA1012 This test is specifically checking for a nil context
 	Exchange(nil, req, "")
 }
+
+func TestClient_Exchange_readTimeout(t *testing.T) {
+	secret := []byte(`12345`)
+
+	var server *TestServer
+	handler := HandlerFunc(func(w ResponseWriter, r *Request) {
+		time.Sleep(time.Minute)
+		resp := r.Response(CodeAccessAccept)
+		w.Write(resp)
+	})
+	server = NewTestServer(handler, StaticSecretSource(secret))
+	defer server.Close()
+
+	req := New(CodeAccessRequest, secret)
+
+	client := Client{
+		ResponseTimeout: time.Second,
+	}
+	resp, err := client.Exchange(context.Background(), req, server.Addr)
+	if resp != nil {
+		t.Fatalf("got non-nil response (%v); expected nil", resp)
+	}
+	if err == nil {
+		t.Fatal("got nil error; expected one")
+	}
+	if !err.(net.Error).Timeout() {
+		t.Fatalf("got err = %v; expected net.Error.Timeout()", err)
+	}
+}

packet.go

@@ -48,11 +48,11 @@ func Parse(b, secret []byte) (*Packet, error) {
 	}
 
 	length := int(binary.BigEndian.Uint16(b[2:4]))
-	if length < 20 || length > MaxPacketLength || len(b) != length {
+	if length < 20 || length > MaxPacketLength || len(b) < length {
 		return nil, errors.New("radius: invalid packet length")
 	}
 
-	attrs, err := ParseAttributes(b[20:])
+	attrs, err := ParseAttributes(b[20:length])
 	if err != nil {
 		return nil, err
 	}

packet_test.go

@@ -267,7 +267,7 @@ func TestParse_invalid(t *testing.T) {
 			"invalid packet length",
 		},
 		{
-			"\x00\xff\x00\x14\x01\x01\x01\x01\x01\x01" +
+			"\x00\xff\x00\x16\x01\x01\x01\x01\x01\x01" +
 				"\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01" +
 				"\x00",
 			"invalid packet length",