Divide code into packages; Use hosts+index to improve performance; Output Grouping. (#21)

Author: misaka4e21

Makefile

@@ -0,0 +1,3 @@
+GO=go
+all:
+	"$(GO)" build -o lmap cmd/lmap/main.go

cmd/lmap/main.go

@@ -0,0 +1,20 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"github.com/LinuxHub-Group/lmap/pkg/lmap"
+	"os"
+)
+
+func main() {
+	isVerbose := false
+	flag.BoolVar(&isVerbose, "v", false, "be verbose")
+	flag.Parse()
+	args := flag.Args()
+	if len(args) < 1 {
+		fmt.Fprintf(os.Stderr, "使用方法：%s [-v] <网络号>/<CIDR>\n", os.Args[0])
+		os.Exit(-1)
+	}
+	lmap.CheckIP(args[0], isVerbose)
+}

lmap.go

@@ -0,0 +1,66 @@
+package lmap
+
+import (
+	"fmt"
+	"net"
+	"os"
+	"sync"
+	"time"
+)
+
+const OUTPUT_IP_PER_LINE = 5
+
+func CheckIP(subnet string, isVerbose bool) {
+	checkerGroup := &sync.WaitGroup{}
+	t := time.Now()
+	hosts, _ := GetAllIPsFromCIDR(subnet)
+	isUsedList := make([]bool, len(hosts))
+	for index, _ := range hosts {
+		time.Sleep(500)
+		checkerGroup.Add(1)
+		go func(index int) {
+			defer checkerGroup.Done()
+			isUsed := Ping(hosts[index])
+			isUsedList[index] = isUsed
+			if isVerbose {
+				if isUsed {
+					println("已使用IP：", hosts[index].String())
+				} else {
+					println("未使用IP：", hosts[index].String())
+				}
+			}
+		}(index)
+	}
+	checkerGroup.Wait()
+	elapsed := time.Since(t)
+	fmt.Fprintln(os.Stderr, "IP扫描完成,耗时", elapsed)
+	println("已使用IP：")
+	printIPList(hosts, true, isUsedList)
+	println("未使用IP：")
+	printIPList(hosts, false, isUsedList)
+}
+
+func printIPList(hosts []net.IP, boolFilter bool, boolFilterTargetList []bool) {
+	firstIndex := 0
+	count := 0
+	for index, ip := range hosts {
+		if boolFilterTargetList[index] == boolFilter {
+			fmt.Print(ip.String())
+			firstIndex = index
+			count = 1
+			break
+		}
+	}
+	for index := firstIndex + 1; index < len(hosts); index++ {
+		if boolFilterTargetList[index] == boolFilter {
+			if count%OUTPUT_IP_PER_LINE == 0 {
+				fmt.Println("")
+			} else {
+				fmt.Print(", ")
+			}
+			fmt.Print(hosts[index].String())
+			count++
+		}
+	}
+	fmt.Println("")
+}

pkg/lmap/check_ip.go

@@ -0,0 +1,9 @@
+package lmap
+
+type ICMP struct {
+	Type        uint8
+	Code        uint8
+	Checksum    uint16
+	Identifier  uint16
+	SequenceNum uint16
+}

pkg/lmap/common.go

@@ -0,0 +1,38 @@
+package lmap
+
+import "net"
+
+func GetAllIPsFromCIDR(cidr string) ([]net.IP, error) {
+	ip, ipnet, err := net.ParseCIDR(cidr)
+	if err != nil {
+		return nil, err
+	}
+
+	var ips []net.IP
+	for ip := ip.Mask(ipnet.Mask); ipnet.Contains(ip); inc(ip) {
+		ips = append(ips, dupIP(ip))
+	}
+	if len(ips) <= 2 {
+		return ips, nil
+	}
+	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 dupIP(ip net.IP) net.IP {
+	// To save space, try and only use 4 bytes
+	if x := ip.To4(); x != nil {
+		ip = x
+	}
+	dup := make(net.IP, len(ip))
+	copy(dup, ip)
+	return dup
+}

pkg/lmap/parse_subnet.go

@@ -0,0 +1,63 @@
+package lmap
+
+import (
+	"bytes"
+	"encoding/binary"
+	"log"
+	"net"
+	"time"
+)
+
+func Ping(ip net.IP) 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.String(), 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)
+}