return errParse on incorrect HTTP, fix #4

jsonrpc2/all_test.go

@@ -6,13 +6,16 @@
 package jsonrpc2
 
 import (
+	"bufio"
 	"bytes"
 	"encoding/json"
 	"errors"
 	"fmt"
 	"io"
 	"io/ioutil"
 	"net"
+	"net/http"
+	"net/http/httptest"
 	"net/rpc"
 	"strings"
 	"testing"
@@ -244,9 +247,47 @@ func TestServerErrorHasNullResult(t *testing.T) {
 func TestUnexpectedError(t *testing.T) {
 	cli, srv := myPipe()
 	go cli.PipeWriter.CloseWithError(errors.New("unexpected error")) // reader will get this error
+	go cli.PipeReader.Close()                                        // writer will get ErrClosedPipe
 	ServeConn(srv)                                                   // must return, not loop
 }
 
+func TestBadHTTP2Server(t *testing.T) {
+	ts := httptest.NewServer(HTTPHandler(nil))
+	// Don't close because of https://github.com/golang/go/issues/12262
+	// defer ts.Close()
+	addr := ts.URL[strings.LastIndex(ts.URL, "/")+1:]
+	for _, c := range []string{"", " ", "{", `{"jsonrpc":"2.0",`} {
+		conn, err := net.Dial("tcp", addr)
+		if err != nil {
+			t.Fatalf("Dial(%s), err = %v", addr, err)
+		}
+		_, err = conn.Write([]byte("POST / HTTP/1.0\r\n" +
+			"Host: localhost\r\n" +
+			"Content-Type: application/json\r\n" +
+			"Accept: application/json\r\n" +
+			"Content-Length: " + fmt.Sprintf("%d", len(c)) + "\r\n" +
+			"\r\n" + c))
+		if err != nil {
+			t.Fatalf("[%#q] Write(), err = %v", c, err)
+		}
+		resp, err := http.ReadResponse(bufio.NewReader(conn), nil)
+		if err != nil {
+			t.Fatalf("[%#q] ReadResponse(), err = %v", c, err)
+		}
+		if resp.StatusCode != http.StatusOK {
+			t.Errorf("[%#q] resp.StatusCode = %d, want %d", c, resp.StatusCode, http.StatusOK)
+		}
+		var r clientResponse
+		err = json.NewDecoder(resp.Body).Decode(&r)
+		if err != nil {
+			t.Errorf("[%#q] Decode(), err = %v", c, err)
+		}
+		if r.Error == nil || r.Error.Code != errParse.Code {
+			t.Errorf("[%#q] r = %v, wait errParse", c, r)
+		}
+	}
+}
+
 // Copied from package net.
 func myPipe() (*pipe, *pipe) {
 	r1, w1 := io.Pipe()

jsonrpc2/server.go

@@ -14,10 +14,11 @@ import (
 )
 
 type serverCodec struct {
-	dec *json.Decoder // for reading JSON values
-	enc *json.Encoder // for writing JSON values
-	c   io.Closer
-	srv *rpc.Server
+	encmutex sync.Mutex    // protects enc
+	dec      *json.Decoder // for reading JSON values
+	enc      *json.Encoder // for writing JSON values
+	c        io.Closer
+	srv      *rpc.Server
 
 	// temporary work space
 	req serverRequest
@@ -126,9 +127,9 @@ func (c *serverCodec) ReadRequestHeader(r *rpc.Request) (err error) {
 	// So, try to send error reply to client before returning error.
 	var raw json.RawMessage
 	if err := c.dec.Decode(&raw); err != nil {
-		if _, ok := err.(*json.SyntaxError); ok {
-			c.enc.Encode(serverResponse{Version: "2.0", ID: &null, Error: errParse})
-		}
+		c.encmutex.Lock()
+		c.enc.Encode(serverResponse{Version: "2.0", ID: &null, Error: errParse})
+		c.encmutex.Unlock()
 		return err
 	}
 
@@ -139,7 +140,9 @@ func (c *serverCodec) ReadRequestHeader(r *rpc.Request) (err error) {
 		c.req.ID = &null
 	} else if err := json.Unmarshal(raw, &c.req); err != nil {
 		if err.Error() == "bad request" {
+			c.encmutex.Lock()
 			c.enc.Encode(serverResponse{Version: "2.0", ID: &null, Error: errRequest})
+			c.encmutex.Unlock()
 		}
 		return err
 	}
@@ -203,6 +206,8 @@ func (c *serverCodec) WriteResponse(r *rpc.Response, x interface{}) error {
 		if len(*replies) == 0 {
 			return nil
 		}
+		c.encmutex.Lock()
+		defer c.encmutex.Unlock()
 		return c.enc.Encode(replies)
 	}
 
@@ -228,6 +233,8 @@ func (c *serverCodec) WriteResponse(r *rpc.Response, x interface{}) error {
 		raw := json.RawMessage(newError(r.Error).Error())
 		resp.Error = &raw
 	}
+	c.encmutex.Lock()
+	defer c.encmutex.Unlock()
 	return c.enc.Encode(resp)
 }