记录Okhttp & golang websocket server 连接问题

Okhttp 报错堆栈

java.net.ProtocolException: Expected HTTP 101 response but was '403 Forbidden'
at okhttp3.internal.ws.RealWebSocket.checkUpgradeSuccess$okhttp(RealWebSocket.kt:224)
at okhttp3.internal.ws.RealWebSocket$connect$1.onResponse(RealWebSocket.kt:170)
at okhttp3.internal.connection.RealCall$AsyncCall.run(RealCall.kt:519)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1167)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:641)
at java.lang.Thread.run(Thread.java:919) 

报错代码

        OkHttpClient mClient = new OkHttpClient.Builder()
                .readTimeout(3, TimeUnit.SECONDS)
                .writeTimeout(3, TimeUnit.SECONDS)
                .connectTimeout(3, TimeUnit.SECONDS)
                .build();
        Request.Builder builder = new Request.Builder();
        Request request =builder.get().url("ws://xxxxx/ws").build();
        mClient.newWebSocket(request,new WebSocketConnect(getContext()));

问题分析 golang 层面

// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package websocket

import (
    "bufio"
    "fmt"
    "io"
    "net/http"
)

func newServerConn(rwc io.ReadWriteCloser, buf *bufio.ReadWriter, req *http.Request, config *Config, handshake func(*Config, *http.Request) error) (conn *Conn, err error) {
    var hs serverHandshaker = &hybiServerHandshaker{Config: config}
    code, err := hs.ReadHandshake(buf.Reader, req)
    if err == ErrBadWebSocketVersion {
        fmt.Fprintf(buf, "HTTP/1.1 %03d %s\r\n", code, http.StatusText(code))
        fmt.Fprintf(buf, "Sec-WebSocket-Version: %s\r\n", SupportedProtocolVersion)
        buf.WriteString("\r\n")
        buf.WriteString(err.Error())
        buf.Flush()
        return
    }
    if err != nil {
        fmt.Fprintf(buf, "HTTP/1.1 %03d %s\r\n", code, http.StatusText(code))
        buf.WriteString("\r\n")
        buf.WriteString(err.Error())
        buf.Flush()
        return
    }
    if handshake != nil {
        err = handshake(config, req)
        if err != nil {
            code = http.StatusForbidden
            fmt.Fprintf(buf, "HTTP/1.1 %03d %s\r\n", code, http.StatusText(code))
            buf.WriteString("\r\n")
            buf.Flush()
            return
        }
    }
    err = hs.AcceptHandshake(buf.Writer)
    if err != nil {
        code = http.StatusBadRequest
        fmt.Fprintf(buf, "HTTP/1.1 %03d %s\r\n", code, http.StatusText(code))
        buf.WriteString("\r\n")
        buf.Flush()
        return
    }
    conn = hs.NewServerConn(buf, rwc, req)
    return
}

// Server represents a server of a WebSocket.
type Server struct {
    // Config is a WebSocket configuration for new WebSocket connection.
    Config

    // Handshake is an optional function in WebSocket handshake.
    // For example, you can check, or don't check Origin header.
    // Another example, you can select config.Protocol.
    Handshake func(*Config, *http.Request) error

    // Handler handles a WebSocket connection.
    Handler
}

// ServeHTTP implements the http.Handler interface for a WebSocket
func (s Server) ServeHTTP(w http.ResponseWriter, req *http.Request) {
    s.serveWebSocket(w, req)
}

func (s Server) serveWebSocket(w http.ResponseWriter, req *http.Request) {
    rwc, buf, err := w.(http.Hijacker).Hijack()
    if err != nil {
        panic("Hijack failed: " + err.Error())
    }
    // The server should abort the WebSocket connection if it finds
    // the client did not send a handshake that matches with protocol
    // specification.
    defer rwc.Close()
    conn, err := newServerConn(rwc, buf, req, &s.Config, s.Handshake)
    if err != nil {
        return
    }
    if conn == nil {
        panic("unexpected nil conn")
    }
    s.Handler(conn)
}

// Handler is a simple interface to a WebSocket browser client.
// It checks if Origin header is valid URL by default.
// You might want to verify websocket.Conn.Config().Origin in the func.
// If you use Server instead of Handler, you could call websocket.Origin and
// check the origin in your Handshake func. So, if you want to accept
// non-browser clients, which do not send an Origin header, set a
// Server.Handshake that does not check the origin.
type Handler func(*Conn)

func checkOrigin(config *Config, req *http.Request) (err error) {
    config.Origin, err = Origin(config, req)
    if err == nil && config.Origin == nil {
        return fmt.Errorf("null origin")
    }
    return err
}

// ServeHTTP implements the http.Handler interface for a WebSocket
func (h Handler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
    s := Server{Handler: h, Handshake: checkOrigin}
    s.serveWebSocket(w, req)
}

经过Debug 得知 golang websocket server 对客户端的 请求头参数有强校验,必须要求请求头中包含 Origin 字段.

func checkOrigin(config *Config, req *http.Request) (err error) {
    config.Origin, err = Origin(config, req)
    if err == nil && config.Origin == nil {
        return fmt.Errorf("null origin")
    }
    return err
}

解决办法 Android 层面

      OkHttpClient mClient = new OkHttpClient.Builder()
              .readTimeout(3, TimeUnit.SECONDS)//设置读取超时时间
              .writeTimeout(3, TimeUnit.SECONDS)//设置写的超时时间
              .connectTimeout(3, TimeUnit.SECONDS)//设置连接超时时间
              .build();
      Request.Builder builder = new Request.Builder();
      // 构建请求时 请求头增加Origin 参数 
      builder.addHeader("Origin","https://xxxx");
      Request request =builder.get().url("ws://xxxxx/ws").build();
      mClient.newWebSocket(request,new WebSocketConnect(getContext()));