Initial commit: Dabit Time Manager project

Python-based time management application with UDP discovery,
TCP protocol communication, time sync, and drift monitoring.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

network/packet_parser.py

@@ -0,0 +1,88 @@
+"""DIBD 응답 패킷 파싱 (가변 길이 지원)"""
+
+from models.controller import Controller
+from config import PROTOCOL_ENCODING
+
+
+def parse_dibd_packet(data: bytes) -> Controller | None:
+    """DIBD 응답 패킷을 파싱하여 Controller 객체를 반환.
+
+    패킷 길이:
+      - 이더넷 전용 모델: 174바이트 (DNS Name까지)
+      - WiFi 지원 모델: 222바이트 (AP Mode까지)
+
+    패킷 구조 (0x88 응답, \r\n으로 필드 구분):
+      0-5:     'DIBD\\r\\n'
+      6-24:    MAC (17자) + \\r\\n
+      25-41:   Local IP (15자) + \\r\\n
+      42-58:   Subnet Mask (15자) + \\r\\n
+      59-75:   Gateway IP (15자) + \\r\\n
+      76-82:   Port (5자) + \\r\\n
+      83-86:   DHCP Mode (2자) + \\r\\n
+      87-103:  Server IP (15자) + \\r\\n
+      104-110: Server Port (5자) + \\r\\n
+      111-114: Server Mode (2자) + \\r\\n
+      115-136: Name (20자) + \\r\\n
+      137-141: KeepAlive (3자) + \\r\\n
+      142-173: DNS Name (30자) + \\r\\n       ← 174바이트 여기까지
+      174-195: AP SSID Name (20자) + \\r\\n   ← 선택
+      196-217: AP SSID PW (20자) + \\r\\n     ← 선택
+      218-221: AP Mode (2자) + \\r\\n         ← 선택
+    """
+    try:
+        text = data.decode(PROTOCOL_ENCODING, errors="replace")
+    except Exception:
+        return None
+
+    # 최소 길이: KeepAlive 필드까지 = 142바이트
+    if len(text) < 142:
+        return None
+
+    if not text.startswith("DIBD"):
+        return None
+
+    ctrl = Controller()
+
+    ctrl.mac = text[6:23].strip()
+    ctrl.ip = _normalize_ip(text[25:40].strip())
+    ctrl.subnet = _normalize_ip(text[42:57].strip())
+    ctrl.gateway = _normalize_ip(text[59:74].strip())
+
+    ctrl.port = _safe_int(text[76:81].strip(), 5000)
+    ctrl.dhcp_mode = _safe_int(text[83:85].strip(), 30) % 30
+    ctrl.server_ip = _normalize_ip(text[87:102].strip())
+    ctrl.server_port = _safe_int(text[104:109].strip(), 0)
+    ctrl.server_mode = _safe_int(text[111:113].strip(), 30) % 30
+
+    ctrl.name = text[115:135].strip()
+    ctrl.keep_alive = _safe_int(text[137:140].strip(), 0)
+
+    # DNS Name (선택 - 174바이트 이상)
+    if len(text) >= 172:
+        ctrl.dns_name = text[142:172].strip()
+
+    # AP SSID (선택 - 222바이트 패킷)
+    if len(text) >= 194:
+        ctrl.ap_ssid_name = text[174:194].strip()
+    if len(text) >= 216:
+        ctrl.ap_ssid_pw = text[196:216].strip()
+    if len(text) >= 220:
+        ctrl.ap_mode = _safe_int(text[218:220].strip(), 30) % 30
+
+    return ctrl
+
+
+def _normalize_ip(ip_str: str) -> str:
+    """패딩된 IP(예: '192.168.000.074')를 일반형(예: '192.168.0.74')으로 변환."""
+    try:
+        parts = ip_str.split(".")
+        return ".".join(str(int(p)) for p in parts)
+    except (ValueError, IndexError):
+        return ip_str
+
+
+def _safe_int(s: str, default: int = 0) -> int:
+    try:
+        return int(s)
+    except (ValueError, TypeError):
+        return default