Merge pull request #20 from LinuxHub-Group/revert-19-directory-structure

Revert "Divide code into packages; Use hosts+index to improve perform…

Author: coolrc136

.gitignore

@@ -1,5 +1,5 @@
 # Binaries for programs and plugins
-/lmap
+lmap
 *.exe
 *.exe~
 *.dll

Makefile

@@ -0,0 +1,169 @@
+package main
+
+import (
+	"bytes"
+	"encoding/binary"
+	"flag"
+	"fmt"
+	"log"
+	"net"
+	"os"
+	"sort"
+	"sync"
+	"sync/atomic"
+	"time"
+)
+
+type ICMP struct {
+	Type        uint8
+	Code        uint8
+	Checksum    uint16
+	Identifier  uint16
+	SequenceNum uint16
+}
+
+func main() {
+	isVerbose := false
+	flag.BoolVar(&isVerbose, "v", false, "be verbose")
+	flag.Parse()
+	args := flag.Args()
+	if len(args) < 1 {
+		fmt.Printf("使用方法：%s [-v] <网络号>/<CIDR>\n", os.Args[0])
+		os.Exit(-1)
+	}
+	CheckIP(args[0], isVerbose)
+}
+
+func CheckIP(subnet string, isVerbose bool) {
+	checkerGroup := &sync.WaitGroup{}
+	t := time.Now()
+	hosts, _ := getAllHostsFromCIDR(subnet)
+	usedIP := make([]string, len(hosts))
+	unusedIP := make([]string, len(hosts))
+	var (
+		usedIndex   int64 = 0
+		unusedIndex int64 = 0
+	)
+	for _, ip := range hosts {
+		time.Sleep(500)
+		checkerGroup.Add(1)
+		go func(data string) {
+			defer checkerGroup.Done()
+			isUsed := ping(data)
+			if isUsed {
+				old := atomic.LoadInt64(&usedIndex)
+				for !atomic.CompareAndSwapInt64(&usedIndex, old, old+1) {
+					old = atomic.LoadInt64(&usedIndex)
+				}
+				usedIP[old] = data
+				if isVerbose {
+					fmt.Println("已使用IP：", data)
+				}
+			} else {
+				old := atomic.LoadInt64(&unusedIndex)
+				for !atomic.CompareAndSwapInt64(&unusedIndex, old, old+1) {
+					old = atomic.LoadInt64(&unusedIndex)
+				}
+				unusedIP[old] = data
+				if isVerbose {
+					fmt.Println("未使用IP：", data)
+				}
+			}
+		}(ip)
+	}
+	checkerGroup.Wait()
+	elapsed := time.Since(t)
+	fmt.Println("IP扫描完成,耗时", elapsed)
+	fmt.Println("已使用IP：", sortIPList(usedIP[:usedIndex]))
+	fmt.Println("未使用IP：", sortIPList(unusedIP[:unusedIndex]))
+}
+
+func sortIPList(ipStrings []string) (result []string) {
+	var ips []net.IP
+	for _, ipString := range ipStrings {
+		ips = append(ips, net.ParseIP(ipString))
+	}
+	sort.Slice(ips, func(i, j int) bool {
+		return bytes.Compare(ips[i], ips[j]) < 0
+	})
+	for _, ip := range ips {
+		result = append(result, ip.String())
+	}
+	return
+}
+
+func getAllHostsFromCIDR(cidr string) ([]string, error) {
+	ip, ipnet, err := net.ParseCIDR(cidr)
+	if err != nil {
+		return nil, err
+	}
+
+	var ips []string
+	for ip := ip.Mask(ipnet.Mask); ipnet.Contains(ip); inc(ip) {
+		ips = append(ips, ip.String())
+	}
+	return ips[1 : len(ips)-1], nil
+}
+
+func inc(ip net.IP) {
+	for j := len(ip) - 1; j >= 0; j-- {
+		ip[j]++
+		if ip[j] > 0 {
+			break
+		}
+	}
+}
+
+func ping(ip string) bool {
+	var icmp ICMP
+	//开始填充数据包
+	icmp.Type = 8 //8->echo message  0->reply message
+
+	recvBuf := make([]byte, 32)
+	var buffer bytes.Buffer
+
+	//先在buffer中写入icmp数据报求去校验和
+	binary.Write(&buffer, binary.BigEndian, icmp)
+	icmp.Checksum = CheckSum(buffer.Bytes())
+	//然后清空buffer并把求完校验和的icmp数据报写入其中准备发送
+	buffer.Reset()
+	binary.Write(&buffer, binary.BigEndian, icmp)
+
+	conn, err := net.DialTimeout("ip4:icmp", ip, 1*time.Second)
+	if err != nil {
+		return false
+	}
+	_, err = conn.Write(buffer.Bytes())
+	if err != nil {
+		log.Println("conn.Write error:", err)
+		return false
+	}
+	conn.SetReadDeadline(time.Now().Add(time.Second * 2))
+	num, err := conn.Read(recvBuf)
+	if err != nil {
+		return false
+	}
+
+	conn.SetReadDeadline(time.Time{})
+
+	return string(recvBuf[0:num]) != ""
+}
+
+func CheckSum(data []byte) uint16 {
+	var (
+		sum    uint32
+		length int = len(data)
+		index  int
+	)
+	for length > 1 {
+		sum += uint32(data[index])<<8 + uint32(data[index+1])
+		index += 2
+		length -= 2
+	}
+	if length > 0 {
+		sum += uint32(data[index])
+	}
+	sum += (sum >> 16)
+
+	return uint16(^sum)
+}