init

cap.go

@@ -0,0 +1,110 @@
+package main
+
+import (
+	"fmt"
+	"log"
+	"net"
+	"os"
+	"os/signal"
+	"syscall"
+
+	"github.com/google/gopacket"
+	"github.com/google/gopacket/layers"
+	"github.com/google/gopacket/pcap"
+	"github.com/google/gopacket/pcapgo"
+)
+
+// 打印可用的网络接口信息
+func printAvailableInterfaces() {
+	devices, err := pcap.FindAllDevs()
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	fmt.Println("可用的网络接口:")
+	for _, device := range devices {
+		fmt.Printf("名称: %s\n描述: %s\n地址: %+v\n\n", device.Name, device.Description, device.Addresses)
+	}
+}
+
+// 判断 IP 是否在链表中
+func isIPInList(ip net.IP) bool {
+	for e := ipList.Front(); e != nil; e = e.Next() {
+		if e.Value.(net.IP).Equal(ip) {
+			return true
+		}
+	}
+	return false
+}
+
+// 打印捕获到的每个数据包的信息
+func printPacketInfo(packet gopacket.Packet) {
+	ipLayer := packet.Layer(layers.LayerTypeIPv4)
+
+	if ipLayer != nil {
+		ip, _ := ipLayer.(*layers.IPv4)
+		ipMutex.Lock()
+		defer ipMutex.Unlock()
+		if !isIPInList(ip.SrcIP) {
+			ipList.PushBack(ip.SrcIP)
+			log.Printf("已添加源 IP: %s 到链表\n", ip.SrcIP)
+
+		}
+	}
+}
+
+func startPacketCapture() {
+	handle, err := pcap.OpenLive(*interfaceName, 65535, true, pcap.BlockForever)
+	if err != nil {
+		log.Fatalf("打开网络接口 %s 出错: %v", *interfaceName, err)
+	}
+	defer handle.Close()
+
+	defer func() {
+		fmt.Println("清理资源...")
+		if handle != nil {
+			handle.Close()
+		}
+	}()
+
+	err = handle.SetBPFFilter(*filter)
+	if err != nil {
+		log.Fatalf("设置 BPF 过滤器出错: %v", err)
+	}
+
+	var pcapWriter *pcapgo.Writer
+	if *outputFile != "" {
+		file, err := os.Create(*outputFile)
+		if err != nil {
+			log.Fatalf("创建输出文件出错: %v", err)
+		}
+		defer file.Close()
+
+		pcapWriter = pcapgo.NewWriter(file)
+		err = pcapWriter.WriteFileHeader(65535, layers.LinkTypeEthernet)
+		if err != nil {
+			log.Fatalf("写入全局头部出错: %v", err)
+		}
+	}
+
+	packetSource := gopacket.NewPacketSource(handle, handle.LinkType())
+	fmt.Printf("正在监听网络接口 %s，使用过滤器 '%s'...\n", *interfaceName, *filter)
+
+	sigChan := make(chan os.Signal, 1)
+	signal.Notify(sigChan, os.Interrupt, syscall.SIGTERM)
+
+	go func() {
+		for packet := range packetSource.Packets() {
+			printPacketInfo(packet)
+			if pcapWriter != nil {
+				err := pcapWriter.WritePacket(packet.Metadata().CaptureInfo, packet.Data())
+				if err != nil {
+					log.Printf("写入数据包出错: %v", err)
+				}
+			}
+		}
+	}()
+
+	<-sigChan
+	fmt.Println("\n停止抓包...")
+}