一.获取gopacket

go get  github.com/google/gopacket

二.编译

1.windows

直接编译即可

2.linux

不能从windows下交叉编译到linux，（安装了MINGW也不行），所以需要在linux上编译。
编译前准备:（Centos示例）

yum -y install gcc
yum -y install gcc-c++
yum -y install libpcap
yum -y install libpcap-devel

三.示例代码

var ListenNetwork  = "Adapter for loopback traffic capture"//监听的网卡
var ListenPort  ="80"//监听的端口

func main()  {
    ptrListenNetwork:= flag.String("i","eth0","监听的网卡")
    ptrListenPort:=flag.String("p","80","监听的端口")
    flag.Parse()
    ListenNetwork=*ptrListenNetwork
    ListenPort=*ptrListenPort
    var deviceTarget=""
    devices, err := pcap.FindAllDevs()
    if err!=nil{
        panic(err.Error())
    }
    for _,v:=range devices{
        fmt.Println(v.Name,v.Description)
        if v.Description==ListenNetwork{//win10 这里用Description来判断网卡，主要是Name太乱了
            deviceTarget=v.Name
            break
        }
        if v.Name==ListenNetwork{//linux
            deviceTarget=v.Name
            break
        }
    }
    signalChan := make(chan os.Signal, 1)
    signal.Notify(signalChan, syscall.SIGHUP, syscall.SIGINT, syscall.SIGKILL)
    ctx, cancel := context.WithCancel(context.Background())
    if deviceTarget!=""{
        go listenPacket(deviceTarget,ctx)
        for {
            select {
            case <-signalChan:
                cancel()
                return
            }
        }
    }
}

func listenPacket(iface string, ctx context.Context) {
    handle,err:=pcap.OpenLive(iface,65536,true,-time.Millisecond * 10)
    if err!=nil{
        fmt.Println(err.Error())
        return
    }
    defer handle.Close()
    err=handle.SetBPFFilter(fmt.Sprintf("(src port %s) or (dst port %s)",listenPort,listenPort))
    if err!=nil{
        fmt.Println(err.Error())
        return
    }
    ps := gopacket.NewPacketSource(handle, handle.LinkType())
    var rxLen int64
    var txLen int64
    var packId int64
    fmt.Println(fmt.Sprintf("listen device:%s,port:%s",iface,ListenPort))
    for {
        select {
        case <-ctx.Done():
            return
        case p := <-ps.Packets():
            //fmt.Println(p.Metadata().CaptureInfo.Timestamp,p.Metadata().CaptureInfo.Length)
            //fmt.Println(p.NetworkLayer().NetworkFlow().String())
            //fmt.Println(p.TransportLayer().TransportFlow().Endpoints())
            srcEndpoint,dstEndpoint:=p.TransportLayer().TransportFlow().Endpoints()
            srcPort,dstPort:=srcEndpoint.String(),dstEndpoint.String()
            flag1:=false
            if srcPort==ListenPort{
                packId++
                flag1=true
                l:=p.Metadata().Length
                txLen+=int64(l)
                fmt.Println(fmt.Sprintf("PackId:%d,Port:%s send package,len:%d,stats[RX:%d,TX:%d]",packId,ListenPort,l,rxLen,txLen))
            }
            if dstPort==ListenPort{
                if !flag1{
                    packId++
                }
                l:=p.Metadata().Length
                rxLen+=int64(l)
                fmt.Println(fmt.Sprintf("PackId:%d,Port:%s get package,len:%d,stats[RX:%d,TX:%d]",packId,ListenPort,l,rxLen,txLen))
            }
        }
    }
}

注意事项

linux下编译的包移植到其它机器运行，仍依赖于libpcap，但是不需要libpcap-devel

yum -y install libpcap