Files
duidreader/main.go
2025-05-09 22:47:16 +02:00

308 lines
7.3 KiB
Go

// client.go
package main
import (
"bufio"
"bytes"
"encoding/binary"
"encoding/hex"
"encoding/json"
"errors"
"fmt"
"io/fs"
"net/http"
"os"
"path/filepath"
"regexp"
"runtime"
"strconv"
"strings"
"time"
"golang.org/x/sys/windows/registry"
)
type iaidInfo struct {
Source string // Pfad oder Registry-Key
IAID uint32
}
// ---------- Linux ----------
var (
reDhclientIAID = regexp.MustCompile(`\biaid\s+(\d+);`) // dhclient, NM
reKVIAID = regexp.MustCompile(`^IAID=(\d+)`) // systemd-networkd
)
func iaidsLinux() ([]iaidInfo, error) {
candidates := []string{
"/var/lib/NetworkManager",
"/var/lib/dhclient", // manche Distros
"/run/systemd/netif/leases", // systemd-networkd
"/var/lib/dhcpcd", "/var/lib/dhcpcd5",
}
var out []iaidInfo
visit := func(path string, d fs.DirEntry, err error) error {
if err != nil || d.IsDir() {
return nil
}
f, err := os.Open(path)
if err != nil {
return nil
}
defer f.Close()
sc := bufio.NewScanner(f)
for sc.Scan() {
line := sc.Text()
if m := reDhclientIAID.FindStringSubmatch(line); len(m) == 2 {
if v, _ := strconv.ParseUint(m[1], 10, 32); v != 0 {
out = append(out, iaidInfo{path, uint32(v)})
break
}
}
if m := reKVIAID.FindStringSubmatch(line); len(m) == 2 {
if v, _ := strconv.ParseUint(m[1], 10, 32); v != 0 {
out = append(out, iaidInfo{path, uint32(v)})
break
}
}
}
return nil
}
for _, dir := range candidates {
_ = filepath.WalkDir(dir, visit)
}
if len(out) == 0 {
return nil, fmt.Errorf("keine IAID-Datei gefunden (root-Rechte?)")
}
return out, nil
}
// ---------- Windows ----------
/*func iaidsWindows() ([]iaidInfo, error) {
base := `SYSTEM\CurrentControlSet\Services\Tcpip6\Parameters\Interfaces`
root, err := registry.OpenKey(registry.LOCAL_MACHINE, base, registry.READ)
if err != nil {
return nil, err
}
defer root.Close()
names, _ := root.ReadSubKeyNames(-1)
var out []iaidInfo
for _, n := range names {
k, err := registry.OpenKey(root, n, registry.READ)
if err != nil {
continue
}
val, _, err := k.GetIntegerValue("IAID")
k.Close()
if err == nil {
out = append(out, iaidInfo{
Source: base + `\` + n + `\IAID`,
IAID: uint32(val),
})
}
}
if len(out) == 0 {
return nil, fmt.Errorf("kein IAID-Wert in der Registry")
}
return out, nil
}*/
func iaidsWindows() ([]iaidInfo, error) {
const base = `SYSTEM\CurrentControlSet\Services\Tcpip6\Parameters\Interfaces`
root, err := registry.OpenKey(registry.LOCAL_MACHINE, base, registry.READ)
if err != nil {
return nil, err
}
defer root.Close()
var out []iaidInfo
guidKeys, _ := root.ReadSubKeyNames(-1)
for _, g := range guidKeys {
k, err := registry.OpenKey(root, g, registry.READ)
if err != nil {
continue
}
if v, _, err := k.GetIntegerValue("Dhcpv6Iaid"); err == nil {
out = append(out, iaidInfo{Source: base + `\` + g, IAID: uint32(v)})
k.Close()
continue
}
// --- Fallback: MAC → IAID (letzte 3 Bytes), falls DWORD fehlt ---
if mac, _, err := k.GetBinaryValue("NetworkAddress"); err == nil && len(mac) >= 6 {
iaid := uint32(mac[3])<<16 | uint32(mac[4])<<8 | uint32(mac[5])
out = append(out, iaidInfo{Source: base + `\` + g + " (computed)", IAID: iaid})
}
k.Close()
}
if len(out) == 0 {
return nil, fmt.Errorf("weder Dhcpv6Iaid noch MAC-basierten Fallback gefunden - nutzt der Client überhaupt DHCPv6?")
}
return out, nil
}
// ---------- Fallback: IAID selbst ableiten (MAC → 3 Byte) ----------
func iaidFromMAC(mac []byte, ifindex int) uint32 {
if len(mac) >= 3 {
return binary.BigEndian.Uint32([]byte{0, mac[len(mac)-3], mac[len(mac)-2], mac[len(mac)-1]})
}
// Notlösung: Interface-Index + 0xA0 im obersten Byte
return uint32(0xA0000000 | (ifindex & 0x00FFFFFF))
}
/*######################################################################################################*/
/*######################################################################################################*/
/*######################################################################################################*/
/*######################################################################################################*/
/*######################################################################################################*/
// ---------- Datentyp, der an den Server geschickt wird ----------
type payload struct {
Hostname string `json:"hostname"`
DUIDs []string `json:"duids"` // hex-codiert
IAIDs []uint32
}
// ---------- Linux ----------
func duidsLinux() ([][]byte, error) {
candidates := []string{
"/var/lib/NetworkManager",
"/var/lib/dhcp",
"/var/lib/systemd/network",
"/run/systemd/netif/leases",
}
var out [][]byte
for _, dir := range candidates {
_ = filepath.WalkDir(dir, func(path string, d fs.DirEntry, err error) error {
if err != nil || d.IsDir() {
return nil
}
buf, err := os.ReadFile(path)
if err != nil {
return nil
}
if duid := extractDUID(buf); len(duid) > 0 {
out = append(out, duid)
}
return nil
})
}
if len(out) == 0 {
return nil, errors.New("keine DUID gefunden")
}
return out, nil
}
// ---------- Windows ----------
func duidsWindows() ([][]byte, error) {
k, err := registry.OpenKey(registry.LOCAL_MACHINE,
`SYSTEM\CurrentControlSet\Services\Tcpip6\Parameters`,
registry.READ)
if err != nil {
return nil, err
}
defer k.Close()
val, _, err := k.GetBinaryValue("Dhcpv6DUID")
if err != nil {
return nil, err
}
return [][]byte{val}, nil
}
// ---------- Hilfsfunktionen ----------
func extractDUID(b []byte) []byte {
if idx := bytes.Index(b, []byte("default-duid")); idx >= 0 {
start := bytes.IndexByte(b[idx:], '"') + idx + 1
end := bytes.IndexByte(b[start:], '"') + start
hexEsc := bytes.ReplaceAll(b[start:end], []byte(`\x`), nil)
duid, _ := hex.DecodeString(string(hexEsc))
return duid
}
hexOnly := strings.TrimSpace(string(b))
if len(hexOnly) >= 28 && allHex(hexOnly) { // plausibel?
duid, _ := hex.DecodeString(hexOnly)
return duid
}
return nil
}
func allHex(s string) bool {
for _, c := range s {
if !strings.ContainsRune("0123456789abcdefABCDEF", c) {
return false
}
}
return true
}
// ---------- main ----------
func main() {
var raw [][]byte
var all []iaidInfo
var err error
var err1 error
switch runtime.GOOS {
case "windows":
raw, err = duidsWindows()
all, err1 = iaidsWindows()
default:
raw, err = duidsLinux()
all, err1 = iaidsLinux()
}
if err != nil {
fmt.Fprintln(os.Stderr, err)
}
if err1 != nil {
fmt.Fprintln(os.Stderr, err1)
}
for _, ia := range all {
fmt.Printf("%-60s 0x%08x (%d)\n", ia.Source, ia.IAID, ia.IAID)
}
var gh []uint32
for _, bh := range all {
gh = append(gh, bh.IAID)
}
//host, _ := os.Hostname()
host := "PC1020"
p := payload{
Hostname: host,
DUIDs: make([]string, len(raw)),
IAIDs: gh,
}
for i, d := range raw {
p.DUIDs[i] = hex.EncodeToString(d)
}
// --- JSON kodieren ---
body, _ := json.Marshal(p)
// --- HTTP senden ---
url := "http://localhost:8080/register" // <-- ggf. anpassen
req, _ := http.NewRequest(http.MethodPost, url, bytes.NewReader(body))
req.Header.Set("Content-Type", "application/json")
client := &http.Client{Timeout: 5 * time.Second}
resp, err := client.Do(req)
if err != nil {
fmt.Fprintln(os.Stderr, "HTTP-Fehler:", err)
os.Exit(1)
}
defer resp.Body.Close()
fmt.Println("Server-Antwort:", resp.Status)
}