Go1.10使用Windows系统API查看网络链接情况

package main

import (
    "fmt"
    "syscall"
    "unsafe"
)

const ERROR_INSUFFICIENT_BUFFER = 122

func main() {
    lazydll := syscall.NewLazyDLL("Iphlpapi.dll")
    proc := lazydll.NewProc("GetTcpTable2")

    var mibtable2 MIB_TCPTABLE2
    size := unsafe.Sizeof(mibtable2)

    //第一次执行是获取缓存区大小,然后根据返回的size申请对应长度的内存
    r, _, err := proc.Call(uintptr(unsafe.Pointer(&mibtable2)), uintptr(unsafe.Pointer(&size)), 1)
    if err != nil && r != 0 {
        if r == ERROR_INSUFFICIENT_BUFFER {
            buf := make([]byte, size)
            r, _, err = proc.Call(uintptr(unsafe.Pointer(&buf[0])), uintptr(unsafe.Pointer(&size)), 1)
            if r != 0 {
                fmt.Printf("Get tcp table error:%s\n", err.Error())
                return
            }
            var index = int(unsafe.Sizeof(mibtable2.dwNumEntries))
            var step = int(unsafe.Sizeof(mibtable2.table))
            dwNumEntries := *(*uint32)(unsafe.Pointer(&buf[0]))
            for i := 0; i < int(dwNumEntries); i++ {
                mibs := *(*MIB_TCPROW2)(unsafe.Pointer(&buf[index]))
                index += step
                fmt.Println(mibs)
            }
        }
    }
}

type inet_ntoa uint32
//地址转化
func (i inet_ntoa) String() string {
    return fmt.Sprintf("%d.%d.%d.%d", i&255, i>>8&255, i>>16&255, i>>24&255)
}

type ntohs uint32
//端口转化
func (i ntohs) String() string {
    return fmt.Sprint(syscall.Ntohs(uint16(i)))
}

type TCP_CONNECTION_OFFLOAD_STATE uint32
//状态枚举
var _MIB_TCP_STATE = map[uint32]string{
    1:  "CLOSED",
    2:  "LISTEN",
    3:  "SYN_SENT",
    4:  "SYN_RCVD",
    5:  "ESTABLISHED",
    6:  "FIN_WAIT1",
    7:  "FIN_WAIT2",
    8:  "CLOSE_WAIT",
    9:  "CLOSING",
    10: "LAST_ACK",
    11: "TIME_WAIT",
    12: "DELETE_TCB",
}

type MIB_TCP_STATE uint32

func (m MIB_TCP_STATE) String() string {
    return _MIB_TCP_STATE[uint32(m)]
}

type MIB_TCPROW2 struct {
    dwState        MIB_TCP_STATE
    dwLocalAddr    inet_ntoa
    dwLocalPort    ntohs
    dwRemoteAddr   inet_ntoa
    dwRemotePort   ntohs
    dwOwningPid    uint32
    dwOffloadState TCP_CONNECTION_OFFLOAD_STATE
}

func (M MIB_TCPROW2) String() string {
    return fmt.Sprintf("%s\t%s\t%s\t%s\t%s\t%d", M.dwLocalAddr, M.dwLocalPort, M.dwRemoteAddr, M.dwRemotePort, M.dwState, M.dwOwningPid)
}

type MIB_TCPTABLE2 struct {
    dwNumEntries uint32
    table        [1]MIB_TCPROW2
}

/*
const (
    //MIB_TCPTABLE
    TCP_TABLE_BASIC_LISTENER uintptr = iota + 1
    TCP_TABLE_BASIC_CONNECTIONS
    TCP_TABLE_BASIC_ALL

    //MIB_TCPTABLE_OWNER_PID
    TCP_TABLE_OWNER_PID_LISTENER
    TCP_TABLE_OWNER_PID_CONNECTIONS
    TCP_TABLE_OWNER_PID_ALL

    //MIB_TCPTABLE_OWNER_MODULE
    TCP_TABLE_OWNER_MODULE_LISTENER
    TCP_TABLE_OWNER_MODULE_CONNECTIONS
    TCP_TABLE_OWNER_MODULE_ALL
)

const (
    AF_INET  = 2
    AF_INET6 = 23
)

type MIB_TCPROW_OWNER_PID struct {
    dwState      MIB_TCP_STATE
    dwLocalAddr  inet_ntoa
    dwLocalPort  ntohs
    dwRemoteAddr inet_ntoa
    dwRemotePort ntohs
    dwOwningPid  uint32
}

func (M MIB_TCPROW_OWNER_PID) String() string {
    return fmt.Sprintf("%s %s %s %s %s %d", M.dwLocalAddr, M.dwLocalPort, M.dwRemoteAddr, M.dwRemotePort, M.dwState, M.dwOwningPid)
}

func MIB_TCPROW_OWNER_PID_TOSTRING(p unsafe.Pointer) fmt.Stringer {
    return *(*MIB_TCPROW_OWNER_PID)(p)
}

type MIB_TCPTABLE_OWNER_PID struct {
    dwNumEntries uint32
    table        [1]MIB_TCPROW_OWNER_PID
}
*/