Network.go

package main

import (
	"fmt"
	"net"
	"sort"
	"syscall"
	"unsafe"
)

//IP		IP地址
//MAC		MAC地址
//GateWay	网关
type Network struct {
	IP      map[string]string `json:"ip"`
	MAC     map[string]string `json:"mac"`
	GateWay []GateWay         `json:"gateway"`
}

//路由信息
type rtInfo struct {
	Dst              net.IPNet
	Gateway, PrefSrc net.IP
	OutputIface      uint32
	Priority         uint32
}

type routeSlice []*rtInfo

//路由器信息
type router struct {
	ifaces []net.Interface
	addrs  []net.IP
	v4     routeSlice
}

//网关
type GateWay struct {
	InterfaceName string `json:"interface_name"`
	GateWay       string `json:"gate_way"`
	Ip            string `json:"ip"`
}

//获取路由信息
func getRouteInfo() (*router, error) {
	rtr := &router{}
	tab, err := syscall.NetlinkRIB(syscall.RTM_GETROUTE, syscall.AF_INET)
	if err != nil {
		return nil, err
	}
	msgs, err := syscall.ParseNetlinkMessage(tab)
	if err != nil {
		return nil, err
	}
	for _, m := range msgs {
		switch m.Header.Type {
		case syscall.NLMSG_DONE:
			break
		case syscall.RTM_NEWROUTE:
			rtmsg := (*syscall.RtMsg)(unsafe.Pointer(&m.Data[0]))
			attrs, err := syscall.ParseNetlinkRouteAttr(&m)
			if err != nil {
				return nil, err
			}
			routeInfo := rtInfo{}
			rtr.v4 = append(rtr.v4, &routeInfo)
			for _, attr := range attrs {
				switch attr.Attr.Type {
				case syscall.RTA_DST:
					routeInfo.Dst.IP = net.IP(attr.Value)
					routeInfo.Dst.Mask = net.CIDRMask(int(rtmsg.Dst_len), len(attr.Value)*8)
				case syscall.RTA_GATEWAY:
					routeInfo.Gateway = net.IPv4(attr.Value[0], attr.Value[1], attr.Value[2], attr.Value[3])
				case syscall.RTA_OIF:
					routeInfo.OutputIface = *(*uint32)(unsafe.Pointer(&attr.Value[0]))
				case syscall.RTA_PRIORITY:
					routeInfo.Priority = *(*uint32)(unsafe.Pointer(&attr.Value[0]))
				case syscall.RTA_PREFSRC:
					routeInfo.PrefSrc = net.IPv4(attr.Value[0], attr.Value[1], attr.Value[2], attr.Value[3])
				}
			}
		}
	}
	sort.Slice(rtr.v4, func(i, j int) bool {
		return rtr.v4[i].Priority < rtr.v4[j].Priority
	})
	ifaces, err := net.Interfaces()
	if err != nil {
		return nil, err
	}
	for i, iface := range ifaces {
		if i != iface.Index-1 {
			break
		}
		if iface.Flags&net.FlagUp == 0 {
			continue
		}
		rtr.ifaces = append(rtr.ifaces, iface)
		ifaceAddrs, err := iface.Addrs()
		if err != nil {
			return nil, err
		}
		var addrs net.IP
		for _, addr := range ifaceAddrs {
			if inet, ok := addr.(*net.IPNet); ok {
				if v4 := inet.IP.To4(); v4 != nil {
					if addrs == nil {
						addrs = v4
					}
				}
			}
		}
		rtr.addrs = append(rtr.addrs, addrs)
	}
	return rtr, nil
}

//获取网关信息
func getGateWay() []GateWay {
	newRoute, err := getRouteInfo()
	if err != nil {
		fmt.Println(err)
		return nil
	}
	var gateWays []GateWay
	for _, rt := range newRoute.v4 {
		var gateway GateWay
		if rt.Gateway != nil {
			gateway.InterfaceName = newRoute.ifaces[rt.OutputIface-1].Name
			gateway.GateWay = rt.Gateway.String()
			gateway.Ip = newRoute.addrs[rt.OutputIface-1].String()
			gateWays = append(gateWays, gateway)
		}
	}
	return gateWays
}

//获取IP地址
func GetIpAddrs() map[string]string {
	mpIp := make(map[string]string)
	//获取网络接口
	ifaces, err := net.Interfaces()
	if err != nil {
		fmt.Print(fmt.Errorf("localAddresses: %+v\n", err.Error()))
		return nil
	}
	//遍历网络接口
	for _, i := range ifaces {
		addrs, err := i.Addrs()
		if err != nil {
			fmt.Print(fmt.Errorf("localAddresses: %+v\n", err.Error()))
			continue
		}
		//获取网络接口的地址
		for _, a := range addrs {
			mpIp[i.Name] = a.String()
			//fmt.Printf("%v : %s \n", i.Name, a.String())
		}
	}
	return mpIp
}

//获取硬件地址
func GetMacAddrs() map[string]string {
	mpMac := make(map[string]string)
	netInterfaces, err := net.Interfaces()
	if err != nil {
		panic(err)
	}
	for _, netInterface := range netInterfaces {
		macAddr := netInterface.HardwareAddr.String()
		if len(macAddr) == 0 {
			continue
		}
		mpMac[netInterface.Name] = macAddr
	}
	return mpMac
}

//获取网络信息
func GetNetInfo() Network {
	ip := GetIpAddrs()
	mac := GetMacAddrs()
	gateways := getGateWay()
	netinfo := Network{
		IP:      ip,
		MAC:     mac,
		GateWay: gateways,
	}
	return netinfo
}