first commit

libpcap/libpcap.go

@@ -0,0 +1,77 @@
+package libpcap
+
+import (
+	"fmt"
+	"github.com/google/gopacket"
+	"github.com/google/gopacket/pcap"
+)
+
+type NetCatch struct {
+	eth      string
+	host     string
+	sentence string
+	fn       func(gopacket.Packet)
+	*pcap.Handle
+}
+
+func (n *NetCatch) SetRecall(fn func(p gopacket.Packet)) {
+	n.fn = fn
+}
+
+func FindAllDevs() ([]pcap.Interface, error) {
+	return pcap.FindAllDevs()
+}
+
+func NewCatch(host string, sentence string) (*NetCatch, error) {
+	ifs, err := pcap.FindAllDevs()
+	if err != nil {
+		return nil, err
+	}
+	eth := ""
+	for _, v := range ifs {
+		if host == "127.0.0.1" && v.Name == "\\Device\\NPF_Loopback" {
+			eth = v.Name
+		}
+		for _, addr := range v.Addresses {
+			if addr.IP.String() == host {
+				eth = v.Name
+			}
+		}
+	}
+	if len(eth) == 0 {
+		return nil, fmt.Errorf("cannot found eth")
+	}
+	nc := new(NetCatch)
+	nc.host = host
+	nc.eth = eth
+	nc.sentence = sentence
+	return nc, nil
+}
+
+func NewCatchEth(eth string, sentence string) (*NetCatch, error) {
+	nc := new(NetCatch)
+	nc.eth = eth
+	nc.sentence = sentence
+	return nc, nil
+}
+
+func (n *NetCatch) Run() error {
+	if n.eth == "" {
+		return fmt.Errorf("no pcap device")
+	}
+	handle, err := pcap.OpenLive(n.eth, 65535, true, pcap.BlockForever)
+	if err != nil {
+		return err
+	}
+	n.Handle = handle
+	if err = handle.SetBPFFilter(n.sentence); err != nil {
+		return err
+	}
+	pks := gopacket.NewPacketSource(handle, handle.LinkType())
+	for packet := range pks.Packets() {
+		if n.fn != nil {
+			n.fn(packet)
+		}
+	}
+	return nil
+}