go http数据转发

package main
 
import (
    "bytes"
    "flag"
    "fmt"
    "io"
    "log"
    "net"
    "os"
    "strings"
    "time"
)
 
func main() {
    var srcHost, agencyHost string
    flag.StringVar(&srcHost, "srcHost", "", "srcHost")
    flag.StringVar(&agencyHost, "agencyHost", "", "agencyHost")
    flag.Parse()
    if srcHost == "" || agencyHost == "" {
        fmt.Fprintf(os.Stderr, "Fatal error: %s", "参数为空")
        os.Exit(1)
    }
    //建立socket，监听端口
    netListen, err := net.Listen("tcp", srcHost)
    CheckError(err)
    defer netListen.Close()
 
    Log("Waiting for clients")
    for {
        conn, err := netListen.Accept()
        //如果没有请求就一直等待
        if err != nil {
            continue
        }
        if conn != nil {
            Log(conn.RemoteAddr().String(), " tcp connect success")
            go handleConnection(conn, agencyHost) //go 可以实现异步并发请求
        }
    }
}
 
//处理连接
func handleConnection(conn net.Conn, agencyHost string) {
    time.Sleep(10 * time.Millisecond)
    buffer := ReceiveData(conn)
    if len(buffer) > 1 {
        arr := strings.Split(string(buffer), "\r\n")
        if len(arr) > 1 {
            arr[1] = "Host: " + agencyHost
            newstr := strings.Join(arr, "\r\n")
            SendAgencyHost([]byte(newstr), agencyHost, conn)
        }
    }
    conn.Close()
}
func SendAgencyHost(data []byte, host string, baseconn net.Conn) {
    conn, _ := net.Dial("tcp", host)
    conn.Write(data)
    time.Sleep(10 * time.Millisecond)
    bufferHead := ReceiveData(conn)
    time.Sleep(10 * time.Millisecond)
    bufferBody := ReceiveData(conn)
    var buf bytes.Buffer
    buf.Write(bufferHead)
    buf.Write(bufferBody)
    baseconn.Write(buf.Bytes())
    conn.Close()
}
 
//接收数据统一方法
func ReceiveData(conn net.Conn) []byte {
    var buf bytes.Buffer
    buffer := make([]byte, 8192)
    for {
        sizenew, err := conn.Read(buffer)
        buf.Write(buffer[:sizenew])
        if err == io.EOF || sizenew < 8192 {
            break
        }
    }
    return buf.Bytes()
}
 
//打印信息统一方法
func Log(v ...interface{}) {
    log.Println(v...)
}
 
//执行错误处理方法
func CheckError(err error) {
    if err != nil {
        fmt.Fprintf(os.Stderr, "Fatal error: %s", err.Error())
        os.Exit(1)
    }
}