from scapy.all import sniff, UDP, IP, get_if_list
import struct

# === 🧾 設定區 ===
TARGET_IP = "169.254.11.110"      # 目標設備 IP
TARGET_PORT = 2312                # UDP 埠口
INTERFACE_NAME = r"\Device\NPF_{EA61A31B-056F-40E5-ADC8-5CEC3FEFDAE8}"  # ✅ 換成你那張有 IP 的網卡

# === 📦 資料解析函數 ===
def analyze_payload(payload: bytes):
    results = []
    for i in range(0, len(payload), 8):
        block = payload[i:i+8]
        if len(block) < 8:
            continue
        try:
            tag, type_code, value = struct.unpack('<H B x I', block)
            results.append((f"0x{tag:04X}", type_code, value))
        except struct.error:
            continue
    return results

# === 🖥️ 封包處理函數 ===
def handle_packet(pkt):
    if UDP in pkt and IP in pkt:
        ip_layer = pkt[IP]
        udp_layer = pkt[UDP]

        if ip_layer.src == TARGET_IP or ip_layer.dst == TARGET_IP:
            print(f"\n📦 封包來自 {ip_layer.src} → {ip_layer.dst}")
            payload = bytes(udp_layer.payload)

            if len(payload) == 0:
                print("⚠️ 無 payload，跳過")
                return

            result = analyze_payload(payload)
            print(f"📊 分析結果，共 {len(result)} 筆：")
            for tag, typ, val in result:
                print(f"  ➤ Tag: {tag} | Type: {typ} | Value: {val}")

# === ✅ 檢查介面是否存在 ===
if INTERFACE_NAME not in get_if_list():
    print("❌ 找不到指定的網卡：", INTERFACE_NAME)
    print("✅ 可選網卡如下：")
    for iface in get_if_list():
        print("  -", iface)
    exit(1)

# === 🚀 開始監控 ===
print(f"📡 正在監控介面：{INTERFACE_NAME}，目標 IP: {TARGET_IP}, Port: {TARGET_PORT}")
sniff(
    iface=INTERFACE_NAME,
    filter=f"udp and host {TARGET_IP} and port {TARGET_PORT}",
    prn=handle_packet
)