Initial commit

validator/arp.go

@@ -0,0 +1,61 @@
+package main
+
+import (
+	"fmt"
+	"io/ioutil"
+	"net"
+	"strings"
+)
+
+var ARPTable string = "/proc/net/arp"
+
+type ARPEntry struct {
+	IP        net.IP
+	HWType    int
+	Flags     int
+	HWAddress net.HardwareAddr
+	Mask      string
+	Device    string
+}
+
+func ARPAnalyze() (ents []ARPEntry, err error) {
+	var content []byte
+	if content, err = ioutil.ReadFile(ARPTable); err != nil {
+		return
+	}
+
+	for _, line := range strings.Split(string(content), "\n") {
+		f := strings.Fields(line)
+		if len(f) > 5 {
+			var e ARPEntry
+
+			if _, err := fmt.Sscanf(f[1], "0x%x", &e.HWType); err != nil {
+				continue
+			}
+			if _, err := fmt.Sscanf(f[2], "0x%x", &e.Flags); err != nil {
+				continue
+			}
+
+			e.IP = net.ParseIP(f[0])
+			if e.HWAddress, err = net.ParseMAC(f[3]); err != nil {
+				continue
+			}
+			e.Mask = f[4]
+			e.Device = f[5]
+
+			ents = append(ents, e)
+		}
+	}
+
+	return
+}
+
+func ARPContainsIP(ents []ARPEntry, ip net.IP) *ARPEntry {
+	for i, e := range ents {
+		if e.IP.Equal(ip) && e.Flags == 2 {
+			return &ents[i]
+		}
+	}
+
+	return nil
+}