v1

2026-07-24 12:25:14 +02:00
parent 909ec41b39
commit fc8813c14a
28 changed files with 1805 additions and 0 deletions
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+"""Parse wmbusmeters output lines into structured events.
+
+wmbusmeters is run with ``--format=json --verbose`` plus a wildcard
+``scan auto '*' NOKEY`` meter. That produces, for *every* received telegram:
+
+* a verbose DLL line on stderr (universal discovery), e.g.::
+
+    (telegram) DLL L=2a C=44 (from meter SND_NR) M=2c2d (KAM) A=76348799 \
+        VER=1b TYPE=16 (Cold water meter) (driver kamwater) DEV=rtlwmbus[] RSSI=97
+
+* and, when a matching keyed meter is configured, a decrypted JSON line on
+  stdout, e.g. ``{"_":"telegram","id":"76348799","total_m3":6.408,...}``.
+
+stdout and stderr are merged, so a single parser handles both.
+"""
+
+from __future__ import annotations
+
+import json
+import re
+from typing import Optional
+
+_DLL_RE = re.compile(
+    r"\(telegram\) DLL "
+    r"L=(?P<L>[0-9a-fA-F]+) "
+    r"C=(?P<C>[0-9a-fA-F]+).*?"
+    r"M=(?P<mhex>[0-9a-fA-F]+) \((?P<mfct>[A-Z?]+)\) "
+    r"A=(?P<id>\w+) "
+    r"VER=(?P<ver>[0-9a-fA-F]+) "
+    r"TYPE=(?P<type>[0-9a-fA-F]+) \((?P<media>[^)]*)\) "
+    r"\(driver (?P<driver>\w+)\)"
+    r"(?:.*?RSSI=(?P<rssi>-?\d+))?"
+)
+
+# JSON keys that are metadata, not measurement values.
+_META = {"_", "media", "meter", "name", "id", "timestamp", "device", "rssi_dbm"}
+
+# OMS/EN13757-3 TPL security modes we can name.
+_SEC_MODE = {"AES_CBC_IV": 5, "AES_CBC_NO_IV": 4, "AES_CTR": 7, "AES_DES": 2}
+
+
+def _find(pattern: str, line: str) -> str:
+    m = re.search(pattern, line)
+    return m.group(1) if m else ""
+
+
+def parse_dll(line: str) -> Optional[dict]:
+    m = _DLL_RE.search(line)
+    if not m:
+        return None
+    g = m.groupdict()
+    return {
+        "type": "dll",
+        "id": g["id"],
+        "manufacturer": g["mfct"],
+        "version": g["ver"],
+        "media": g["media"],
+        "driver": g["driver"],
+        "c_field": g["C"],
+        "rssi": int(g["rssi"]) if g["rssi"] is not None else None,
+    }
+
+
+def parse_json_telegram(line: str) -> Optional[dict]:
+    line = line.strip()
+    if not line.startswith("{"):
+        return None
+    try:
+        obj = json.loads(line)
+    except json.JSONDecodeError:
+        return None
+    if obj.get("_") != "telegram":
+        return None
+    fields = {k: v for k, v in obj.items() if k not in _META}
+    return {
+        "type": "json",
+        "id": str(obj.get("id", "")),
+        "driver": obj.get("meter", ""),
+        "media": obj.get("media", ""),
+        "name": obj.get("name", ""),
+        "timestamp": obj.get("timestamp", ""),
+        "rssi": obj.get("rssi_dbm"),
+        "fields": fields,
+    }
+
+
+def parse_ell(line: str) -> Optional[dict]:
+    """Extended Link Layer line — carries ELL-layer encryption (e.g. AES-CTR)."""
+    if "(telegram) ELL" not in line:
+        return None
+    enc = "AES-CTR" if "AES_CTR" in line else ("AES-CBC" if "AES_CBC" in line else "")
+    return {
+        "type": "ell",
+        "ci": _find(r"CI=(\w+)", line),
+        "cc": _find(r"CC=(\w+)", line),
+        "sn": _find(r"SN=(\w+)", line),
+        "session": _find(r"session=(\d+)", line),
+        "enc": enc,
+    }
+
+
+def parse_tpl(line: str) -> Optional[dict]:
+    """Transport Layer line — carries the TPL security mode (5=CBC, 7=CTR)."""
+    if "(telegram) TPL" not in line:
+        return None
+    sec_mode = 0
+    enc = ""
+    for name, mode in _SEC_MODE.items():
+        if name in line:
+            sec_mode = mode
+            enc = "AES-CBC" if "CBC" in name else ("AES-CTR" if "CTR" in name else name)
+            break
+    return {
+        "type": "tpl",
+        "ci": _find(r"CI=(\w+)", line),
+        "acc": _find(r"ACC=(\w+)", line),
+        "sts": _find(r"STS=(\w+)", line),
+        "cfg": _find(r"CFG=(\w+)", line),
+        "nb": _find(r"nb=(\d+)", line),
+        "sec_mode": sec_mode,
+        "enc": enc,
+    }
+
+
+def parse_line(line: str) -> Optional[dict]:
+    """Return a structured event for a wmbusmeters output line, or None."""
+    stripped = line.lstrip()
+    if stripped.startswith("{"):
+        ev = parse_json_telegram(line)
+        if ev is not None:
+            return ev
+    if "(telegram) DLL" in line:
+        return parse_dll(line)
+    if "(telegram) ELL" in line:
+        return parse_ell(line)
+    if "(telegram) TPL" in line:
+        return parse_tpl(line)
+    return None