P25 conventional decode mode + conventional-channel attribution (node-26#24, #20)

op25-container
- generate-config takes p25_mode "conventional" + conv_channels [{frequency,
  name, nac}]. It builds fixed fsk4 channels (up to 2 on one non-tunable SDR,
  DC spike kept off the channels) with no control channel to hunt. Two
  channels send audio to UDP 23456/23457, and audio.py -2 + amplify(2) keeps
  levels.
- tk_drb_conv.py (a tk_p25.rx_ctl subclass, copied into OP25 apps) reports
  voice / NAC / encryption (LC service options + LDU2 ESS algid/keyid) for
  conventional channels and applies the per-channel NAC filter, which stock
  tk_p25 does not. Analog uses it too.
- Trunked P25 config is unchanged when p25_mode is absent.

drb-edge-node
- radio_config: system kind from type + config.mode (missing = trunked).
- conventional.py normalizes the console: a distinctive LC TGID, else the
  channel's last TGID (30 s), else a synthetic per-channel id (freq/100 Hz).
  Encrypted rows are never talkers. With exactly one conventional channel,
  orphan audio is attributed to it at close, which fixes analog recording
  (#20). The synthetic id and the real TGID on one channel never split.
- Health/dashboard: P25 conventional listen tab (/api/listen p25conv), and
  conventional decode + encryption checks. The checkin carries radio_channels.
- Tests: edge 296 pass; op25-container 18 (new CI job). Reviewed by
  drb-audio-review (findings fixed; simultaneous two-channel mixdown filed
  as #26) and drb-qa-review.

Not verified on SDR hardware.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

op25-container/Dockerfile

@@ -31,6 +31,10 @@ RUN ./install.sh -f
 COPY requirements.txt /tmp/requirements.txt
 RUN pip3 install --no-cache-dir -r /tmp/requirements.txt
 
+# DRB's trunking module for P25 conventional channels (node-26#24): reports
+# encryption + NAC and applies the NAC filter, which stock tk_p25 does not.
+COPY op25_addons/tk_drb_conv.py /op25/op25/gr-op25_repeater/apps/tk_drb_conv.py
+
 # Create the run_multi-rx_service.sh script
 COPY run_multi-rx_service.sh /op25/op25/gr-op25_repeater/apps/run_multi-rx_service.sh
 RUN chmod +x /op25/op25/gr-op25_repeater/apps/run_multi-rx_service.sh

op25-container/app/internal/conventional_config.py

@@ -0,0 +1,118 @@
+"""
+P25 conventional OP25 config (node-26#24).
+
+A conventional P25 channel is a fixed voice frequency with no control channel:
+radios key up on it directly, C4FM (fsk4), and identify themselves in the link
+control of each LDU1 (talkgroup + unit id) and the ESS of each LDU2
+(encryption algorithm + key id). Building a `tk_p25.py` trunking config for one
+— what "P25" always meant before — makes OP25 hunt forever for a control
+channel that does not exist, so nothing is ever decoded.
+
+Layout this produces, per boatbod OP25 gr310 `p25_conventional_example.json`:
+
+  * one non-tunable device parked so every channel sits inside its passband;
+  * one channel per frequency, `trunking_sysname: ""` (so the trunking module
+    treats it as conventional), `demod_type: fsk4`;
+  * trunking module `tk_drb_conv.py` with no chans — our thin subclass of
+    tk_p25.rx_ctl that reports encryption and the NAC for conventional
+    channels and applies the per-channel NAC filter (tk_p25 itself does
+    neither for FDMA conventional);
+  * channel N's audio to UDP 23456+N; with two channels audio.py runs in
+    two-channel mode (left = first channel, right = second).
+
+Pure: no file I/O, so it is unit-testable outside the container.
+"""
+from typing import Any, Dict, List, Tuple
+
+from models import ChannelConfig, ConventionalChannel, DeviceConfig, TerminalConfig
+
+# Two is what one audio.py instance can carry (its A and B sockets). A third
+# channel would need a second audio pipeline into PulseAudio.
+MAX_CONVENTIONAL_CHANNELS = 2
+
+AUDIO_UDP_BASE_PORT = 23456
+
+DEVICE_RATE = 1_920_000
+DEVICE_USABLE_BW_PCT = 0.85
+# Half the occupied bandwidth of a 12.5 kHz P25 channel.
+CHANNEL_HALF_BW_HZ = 6_250
+# Keep the RTL-SDR's DC spike off the channels. A single channel (or two very
+# close together) is offset from the centre; channels further apart than
+# 2x this already straddle the spike, so the centre goes between them.
+DC_SPIKE_OFFSET_HZ = 250_000
+DC_SPIKE_CLEARANCE_HZ = 50_000
+
+CONVENTIONAL_TRUNKING_MODULE = "tk_drb_conv.py"
+
+
+def device_center(freqs: List[int]) -> int:
+    lo, hi = min(freqs), max(freqs)
+    mid = (lo + hi) // 2
+    if (hi - lo) // 2 >= DC_SPIKE_CLEARANCE_HZ:
+        return mid
+    return mid + DC_SPIKE_OFFSET_HZ
+
+
+def validate_channels(channels: List[ConventionalChannel]) -> None:
+    """Raise ValueError with an operator-readable reason."""
+    if not channels:
+        raise ValueError("P25 conventional needs at least one channel frequency.")
+    if len(channels) > MAX_CONVENTIONAL_CHANNELS:
+        raise ValueError(
+            f"P25 conventional supports up to {MAX_CONVENTIONAL_CHANNELS} channels on one SDR "
+            f"(got {len(channels)})."
+        )
+    freqs = [c.frequency for c in channels]
+    if len(set(freqs)) != len(freqs):
+        raise ValueError("The same conventional frequency is listed twice.")
+    for c in channels:
+        if c.nac is not None and not (0 < c.nac <= 0xFFF):
+            raise ValueError(f"NAC {c.nac:#x} on {c.frequency / 1e6:.5f} MHz is outside 0x001-0xFFF.")
+    center = device_center(freqs)
+    half = DEVICE_RATE * DEVICE_USABLE_BW_PCT / 2
+    for f in freqs:
+        if abs(f - center) + CHANNEL_HALF_BW_HZ > half:
+            span = (max(freqs) - min(freqs)) / 1e6
+            raise ValueError(
+                f"These channels are {span:.3f} MHz apart — too far for one SDR "
+                f"(max ~{(2 * (half - CHANNEL_HALF_BW_HZ)) / 1e6:.2f} MHz)."
+            )
+
+
+def build_conventional_config(
+    system_name: str,
+    channels: List[ConventionalChannel],
+    gains: str,
+    ppm: float,
+) -> Tuple[Dict[str, Any], bool]:
+    """Return (OP25 config dict, two_channel_audio)."""
+    validate_channels(channels)
+    freqs = [c.frequency for c in channels]
+    center = device_center(freqs)
+
+    chans = []
+    for i, c in enumerate(channels):
+        chans.append(ChannelConfig(
+            name=c.name or f"{system_name} {c.frequency / 1e6:.4f}",
+            trunking_sysname="",
+            enable_analog="off",
+            demod_type="fsk4",
+            filter_type="rc",
+            frequency=c.frequency,
+            meta_stream_name="",
+            destination=f"udp://127.0.0.1:{AUDIO_UDP_BASE_PORT + i}",
+            nac=c.nac,
+            crypt_behavior=2,
+        ))
+
+    device = DeviceConfig(
+        gains=gains, ppm=ppm, tunable=False, frequency=center,
+        rate=DEVICE_RATE, usable_bw_pct=DEVICE_USABLE_BW_PCT,
+    )
+    config = {
+        "channels": [ch.model_dump() for ch in chans],
+        "devices": [device.model_dump()],
+        "trunking": {"module": CONVENTIONAL_TRUNKING_MODULE, "chans": []},
+        "terminal": TerminalConfig().model_dump(),
+    }
+    return config, len(chans) > 1

op25-container/app/internal/liquidsoap_config_utils.py

@@ -2,7 +2,26 @@ import os
 from internal.op25_liq_template import liquidsoap_config_template
 from models import IcecastConfig
 
-def generate_liquid_script(config: IcecastConfig):
+# P25 conventional with two channels (node-26#24): OP25 sends channel A's
+# audio to UDP 23456 and channel B's to 23457, and audio.py -2 puts them on the
+# left and right of the stereo stream. Every output below is mean(input) — mono
+# — so a lone talker on one side would come out 6 dB down; doubling first keeps
+# the common case (one channel keyed) at the same level as single-channel mode.
+# Liquidsoap mixes in float, so the doubling cannot clip before the output.
+_TWO_CHANNEL_AUDIO_ARGS = " -2"
+_TWO_CHANNEL_MIX = "input = amplify(2.0, input)  # two conventional channels, L=A R=B"
+
+
+def render_liquid_script(config: IcecastConfig, two_channel: bool = False) -> str:
+    content = liquidsoap_config_template
+    for key, value in config.model_dump().items():
+        content = content.replace(f"${{{key}}}", str(value))
+    content = content.replace("${audio_py_args}", _TWO_CHANNEL_AUDIO_ARGS if two_channel else "")
+    content = content.replace("${two_channel_mix}", _TWO_CHANNEL_MIX if two_channel else "")
+    return content
+
+
+def generate_liquid_script(config: IcecastConfig, two_channel: bool = False):
     """
     Generates the "*.liq" file that's run by OP25 on startup. 
 
@@ -13,13 +32,7 @@ def generate_liquid_script(config: IcecastConfig):
                           Keys should match the variable names in the template (e.g., 'icecast_host').
     """
     try:
-        content = liquidsoap_config_template
-        # Replace variables
-        for key, value in config.model_dump().items():
-            placeholder = f"${{{key}}}"
-            # Ensure the value is converted to string for replacement
-            content = content.replace(placeholder, str(value))
-            print(f"  - Replaced placeholder {placeholder}")
+        content = render_liquid_script(config, two_channel)
 
         # Write the processed content to the output path
         output_path = "/configs/op25.liq"

op25-container/app/internal/op25_liq_template.py

@@ -17,8 +17,9 @@ ICE_DESCRIPTION = "${icecast_description}"
 ICE_GENRE = "${icecast_genre}"
 # ==========================================================
 
-input = mksafe(input.external(buffer=0.25, channels=2, samplerate=8000, restart_on_error=false, "./audio.py -x 2.5 -s"))
+input = mksafe(input.external(buffer=0.25, channels=2, samplerate=8000, restart_on_error=false, "./audio.py -x 2.5 -s${audio_py_args}"))
 # Consider increasing the buffer value on slow systems such as RPi3. e.g. buffer=0.25
+${two_channel_mix}
 
 # Compression
 input = compress(input, attack = 2.0, gain = 0.0, knee = 13.0, ratio = 2.0, release = 12.3, threshold = -18.0)

op25-container/app/models.py

@@ -49,12 +49,28 @@ class IcecastConfig(BaseModel):
     icecast_genre: Optional[str] = "Public Safety"
 
 
+class P25Mode(str, Enum):
+    TRUNKED = "trunked"
+    CONVENTIONAL = "conventional"
+
+
+class ConventionalChannel(BaseModel):
+    """One fixed P25 conventional voice channel (node-26#24)."""
+    frequency: int                 # Hz
+    name: str = ""
+    nac: Optional[int] = None      # 0x001-0xFFF; None = accept any NAC
+
+
 class ConfigGenerator(BaseModel):
     type: DecodeMode
     systemName: str
-    # P25: control channel list (Hz). NBFM: channels[0] is the one analog
-    # frequency to listen to (Hz).
-    channels: List[Union[int, str]]
+    # P25 trunked: control channel list (Hz). NBFM: channels[0] is the one
+    # analog frequency to listen to (Hz). P25 conventional: unused — see
+    # conv_channels.
+    channels: List[Union[int, str]] = []
+    # P25 only. Missing = trunked, so every existing caller is unchanged.
+    p25_mode: P25Mode = P25Mode.TRUNKED
+    conv_channels: List[ConventionalChannel] = []
     tags: Optional[List[TalkgroupTag]] = None
     whitelist: Optional[List[int]] = None
     icecastConfig: Optional[IcecastConfig] = None
@@ -84,6 +100,13 @@ class ChannelConfig(BaseModel):
     # Key name op25_nbfm.py actually reads (from_dict(config, 'nbfm_squelch_threshold', -60)).
     nbfm_squelch_threshold: Optional[float] = None
     destination: Optional[str] = "udp://127.0.0.1:23456"
+    # P25 conventional only, read by tk_drb_conv.py (not by multi_rx): the NAC
+    # to lock the frame assembler to. multi_rx passes the whole channel dict
+    # through, so an extra key is harmless.
+    nac: Optional[int] = None
+    # Set on the channel itself for conventional (multi_rx forwards it to the
+    # frame assembler). 2 = drop encrypted voice instead of decoding noise.
+    crypt_behavior: Optional[int] = None
     tracking_threshold: Optional[int] = 120
     tracking_feedback: Optional[float] = 0.75
     excess_bw: Optional[float] = 0.2

op25-container/app/routers/op25_controller.py

@@ -8,7 +8,8 @@ import json
 import threading
 from collections import deque
 from typing import Optional
-from models import ConfigGenerator, DecodeMode, ChannelConfig, DeviceConfig, TrunkingConfig, TrunkingChannelConfig, TerminalConfig, MetadataConfig, MetadataStreamConfig, HARDWARE_PRESETS
+from models import ConfigGenerator, DecodeMode, P25Mode, ChannelConfig, DeviceConfig, TrunkingConfig, TrunkingChannelConfig, TerminalConfig, MetadataConfig, MetadataStreamConfig, HARDWARE_PRESETS
+from internal.conventional_config import build_conventional_config, CONVENTIONAL_TRUNKING_MODULE
 from internal.logger import create_logger
 from internal.op25_config_utls import save_talkgroup_tags, save_whitelist, del_none_in_dict, get_current_system_from_config
 from internal.liquidsoap_config_utils import generate_liquid_script
@@ -178,7 +179,20 @@ def create_op25_router():
     @router.post("/generate-config")
     async def generate_config(generator: ConfigGenerator):
         try:
-            if generator.type == DecodeMode.P25:
+            if generator.type == DecodeMode.P25 and generator.p25_mode == P25Mode.CONVENTIONAL:
+                # node-26#24: fixed voice channels, no control channel to hunt.
+                preset = HARDWARE_PRESETS.get(generator.hardware_preset, HARDWARE_PRESETS["other"])
+                ppm = generator.ppm_override if generator.ppm_override is not None else preset["ppm"]
+                try:
+                    config_dict, two_channel = build_conventional_config(
+                        generator.systemName, generator.conv_channels, preset["gains"], ppm,
+                    )
+                except ValueError as e:
+                    raise HTTPException(status_code=400, detail=str(e))
+                if generator.icecastConfig:
+                    generate_liquid_script(generator.icecastConfig, two_channel=two_channel)
+
+            elif generator.type == DecodeMode.P25:
                 preset = HARDWARE_PRESETS.get(generator.hardware_preset, HARDWARE_PRESETS["other"])
                 ppm = generator.ppm_override if generator.ppm_override is not None else preset["ppm"]
                 channels = [ChannelConfig(
@@ -236,9 +250,9 @@ def create_op25_router():
                 preset = HARDWARE_PRESETS.get(generator.hardware_preset, HARDWARE_PRESETS["other"])
                 ppm = generator.ppm_override if generator.ppm_override is not None else preset["ppm"]
                 freq = int(float(generator.channels[0]))
-                # One fixed conventional channel: no trunking section, so
-                # multi_rx adds its default tk_p25 with no chans and reports
-                # the channel as `conventional` on the HTTP terminal.
+                # One fixed conventional channel: a trunking module with no
+                # chans, so the channel is reported as `conventional` on the
+                # HTTP terminal.
                 channels = [ChannelConfig(
                     name=generator.systemName,
                     trunking_sysname="",
@@ -259,6 +273,11 @@ def create_op25_router():
                 config_dict = {
                     "channels": [channel.dict() for channel in channels],
                     "devices": [device.dict() for device in devices],
+                    # Same module as P25 conventional (node-26#24): it reports
+                    # the channel as `conventional` whatever tk_p25 version the
+                    # image was built with, which is what the edge node's
+                    # single-channel attribution keys on (node-26#20).
+                    "trunking": {"module": CONVENTIONAL_TRUNKING_MODULE, "chans": []},
                     "terminal": TerminalConfig().dict(),
                 }
 

op25-container/op25_addons/tk_drb_conv.py

@@ -0,0 +1,263 @@
+"""
+tk_drb_conv — DRB's trunking module for P25 CONVENTIONAL channels (node-26#24).
+
+Copied into OP25's apps directory by the Dockerfile and named as the trunking
+module by op25-container's conventional config, so multi_rx imports it in place
+of tk_p25. It is tk_p25.rx_ctl with the conventional-channel handling replaced;
+trunked receivers (none in a conventional config) still go to the base class.
+
+Why not stock tk_p25: for an FDMA conventional channel it reports the talkgroup
+and unit id from LDU1 link control, but
+
+  * never reports encryption — the encrypted/algid/keyid JSON OP25 sends after
+    every LDU2 carries no grpaddr, and tk_p25 only records `encrypted` when
+    grpaddr != 0 — so an encrypted channel looks exactly like a quiet one;
+  * never reports the NAC it is hearing, and has no per-channel NAC filter;
+  * has no "voice frames are arriving" signal of its own, so a transmission
+    whose link control is unreadable is invisible to the console.
+
+All three matter to the edge node: it attributes audio to a channel from what
+this module reports, and must tell the owner when a channel is encrypted rather
+than silently recording nothing.
+
+Each conventional channel row in `channel_update` keeps every key tk_p25 sends
+(freq, tgid, srcaddr, tag, encrypted, conventional, ...) and adds:
+
+    voice            True while voice frames are arriving (HDU/LDU1/LDU2 seen,
+                     no TDU or sync timeout since)
+    nac              last NAC heard on the channel (int) or None
+    nac_filter       the configured NAC filter (int) or None
+    algid, keyid     ALGID/key id of the current call (None when clear/idle)
+    enc_calls, clear_calls     calls heard since start, by encryption
+    last_enc_algid, last_enc_keyid, last_enc_time, last_clear_time
+
+Message types handled (lower 16 bits of msg.type(), P25 protocol only):
+    0          HDU                 -> voice start
+    3, 15      TDU / TDULC         -> transmission end
+    19         LDU1 link control   -> tgid, srcaddr, service options (E bit)
+    -3         LDU2 ESS JSON       -> encrypted / algid / keyid
+    -1         sync timeout        -> transmission end
+"""
+import ctypes
+import json
+import sys
+import time
+
+import tk_p25
+from helper_funcs import from_dict, get_ordinals
+from log_ts import log_ts
+
+ALGID_CLEAR = 0x80
+SVCOPT_ENCRYPTED = 0x40
+LCW_PROTECTED = 0x80
+LCO_GROUP_VOICE = 0x00
+DUID_HDU, DUID_TDU, DUID_TDULC, DUID_LCW = 0, 3, 15, 19
+M_TIMEOUT, M_JSON_DATA = -1, -3
+
+
+def _parse_nac(value):
+    if value is None or value == "":
+        return None
+    try:
+        nac = int(value, 16) if isinstance(value, str) else int(value)
+    except (TypeError, ValueError):
+        return None
+    return nac if 0 < nac <= 0xFFF else None
+
+
+class rx_ctl(tk_p25.rx_ctl):
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.drb_conv = {}   # msgq_id -> state dict
+
+    def add_receiver(self, msgq_id, config, meta_q=None, freq=0):
+        super().add_receiver(msgq_id, config, meta_q=meta_q, freq=freq)
+        rcvr = self.receivers.get(msgq_id)
+        if rcvr is not None and rcvr.get('rx_rcvr') is not None:
+            return   # trunked receiver: base class owns it
+        self.drb_conv[msgq_id] = {
+            'name': from_dict(config, 'name', str(msgq_id)),
+            'freq': freq,
+            'nac_filter': _parse_nac(config.get('nac')),
+            'nac': None,
+            'voice': False,
+            'tgid': None,
+            'srcaddr': 0,
+            'svc_encrypted': False,
+            'ess_encrypted': False,
+            'algid': None,
+            'keyid': None,
+            'call_start': None,
+            'call_encrypted': False,
+            'logged_tgid': None,
+            'prev_type': None,
+            'enc_calls': 0,
+            'clear_calls': 0,
+            'last_enc_algid': None,
+            'last_enc_keyid': None,
+            'last_enc_time': None,
+            'last_clear_time': None,
+            'last_voice_time': None,
+        }
+
+    def post_init(self):
+        super().post_init()
+        for msgq_id, cs in self.drb_conv.items():
+            if cs['nac_filter'] is not None and self.fa_ctrl is not None:
+                self.fa_ctrl({'tuner': msgq_id, 'cmd': 'set_nac', 'nac': cs['nac_filter']})
+                sys.stderr.write("%s [%d] conventional NAC filter 0x%03x\n" % (log_ts.get(), msgq_id, cs['nac_filter']))
+
+    # ------------------------------------------------------------------
+
+    def _encrypted(self, cs):
+        return cs['svc_encrypted'] or cs['ess_encrypted']
+
+    def _voice_start(self, cs, now):
+        if not cs['voice']:
+            cs['voice'] = True
+            cs['call_start'] = now
+            cs['call_encrypted'] = False
+            cs['logged_tgid'] = None
+        cs['last_voice_time'] = now
+
+    def _voice_end(self, cs, now):
+        if cs['voice']:
+            if cs['call_encrypted']:
+                cs['enc_calls'] += 1
+                cs['last_enc_time'] = now
+            else:
+                cs['clear_calls'] += 1
+                cs['last_clear_time'] = now
+        cs['voice'] = False
+        cs['tgid'] = None
+        cs['srcaddr'] = 0
+        cs['svc_encrypted'] = False
+        cs['ess_encrypted'] = False
+        cs['algid'] = None
+        cs['keyid'] = None
+        cs['call_start'] = None
+        cs['logged_tgid'] = None
+
+    def _note_encryption(self, cs, now):
+        if self._encrypted(cs):
+            cs['call_encrypted'] = True
+            if cs['algid'] is not None:
+                cs['last_enc_algid'] = cs['algid']
+                cs['last_enc_keyid'] = cs['keyid']
+            cs['last_enc_time'] = now
+
+    def _maybe_log_call(self, msgq_id, cs):
+        # One call_log entry per (call, talkgroup), and none for an encrypted
+        # call: it will produce no audio, so a "grant" would only mislead the
+        # edge node's attribution.
+        if cs['tgid'] is None or self._encrypted(cs) or cs['logged_tgid'] == cs['tgid']:
+            return
+        cs['logged_tgid'] = cs['tgid']
+        try:
+            self.log_call(0, msgq_id, cs['freq'], 0, 0, cs['tgid'], cs['name'], cs['srcaddr'], '')
+        except Exception as e:   # older/newer tk_p25 log_call signature
+            sys.stderr.write("%s [%d] conventional call_log failed: %s\n" % (log_ts.get(), msgq_id, e))
+
+    def _process_conv(self, msgq_id, cs, m_type, msg, now):
+        if m_type == M_TIMEOUT or m_type in (DUID_TDU, DUID_TDULC):
+            self._voice_end(cs, now)
+        elif m_type == DUID_HDU:
+            s = msg.to_string()
+            cs['nac'] = get_ordinals(s[0:2]) if len(s) >= 2 else cs['nac']
+            self._voice_start(cs, now)
+        elif m_type == DUID_LCW:
+            s = msg.to_string()
+            if len(s) < 11:
+                return
+            cs['nac'] = get_ordinals(s[0:2])
+            if cs['prev_type'] in (DUID_TDU, DUID_TDULC):
+                return   # TDULC's link control follows its TDU: the call is over
+            lcw = s[2:]
+            self._voice_start(cs, now)
+            pb_sf_lco = get_ordinals(lcw[0:1])
+            if pb_sf_lco & LCW_PROTECTED:
+                # Link control itself is encrypted — the call certainly is.
+                cs['svc_encrypted'] = True
+            elif (pb_sf_lco & 0x3f) == LCO_GROUP_VOICE:
+                svcopts = get_ordinals(lcw[2:3])
+                ga = get_ordinals(lcw[4:6])
+                sa = get_ordinals(lcw[6:9])
+                cs['svc_encrypted'] = bool(svcopts & SVCOPT_ENCRYPTED)
+                if ga:
+                    cs['tgid'] = ga
+                if sa:
+                    cs['srcaddr'] = sa
+            self._note_encryption(cs, now)
+            self._maybe_log_call(msgq_id, cs)
+        elif m_type == M_JSON_DATA:
+            try:
+                js = json.loads(msg.to_string())
+            except (ValueError, TypeError):
+                return
+            if 'encrypted' in js:
+                self._voice_start(cs, now)
+                algid = from_dict(js, 'algid', None)
+                cs['ess_encrypted'] = bool(js.get('encrypted')) and algid != ALGID_CLEAR
+                cs['algid'] = algid if cs['ess_encrypted'] else None
+                cs['keyid'] = from_dict(js, 'keyid', None) if cs['ess_encrypted'] else None
+                self._note_encryption(cs, now)
+            grpaddr = from_dict(js, 'grpaddr', 0)
+            if grpaddr:
+                cs['tgid'] = grpaddr
+                cs['srcaddr'] = from_dict(js, 'srcaddr', 0) or cs['srcaddr']
+                self._maybe_log_call(msgq_id, cs)
+
+    def process_qmsg(self, msg):
+        m_proto = ctypes.c_int16(msg.type() >> 16).value
+        m_rxid = int(msg.arg1()) >> 1
+        if m_proto != 0 or m_rxid not in self.drb_conv:
+            return super().process_qmsg(msg)
+        m_type = ctypes.c_int16(msg.type() & 0xffff).value
+        cs = self.drb_conv[m_rxid]
+        try:
+            self._process_conv(m_rxid, cs, m_type, msg, time.time())
+        except Exception as e:   # never take multi_rx down over a bad frame
+            sys.stderr.write("%s [%d] conventional message type %d failed: %s\n" % (log_ts.get(), m_rxid, m_type, e))
+        cs['prev_type'] = m_type
+
+    def get_chan_status(self):
+        d = json.loads(super().get_chan_status())
+        ids = list(d.get('channels') or [])
+        for msgq_id, cs in self.drb_conv.items():
+            key = str(msgq_id)
+            row = d.get(key) or {}
+            row.update({
+                'freq': cs['freq'],
+                'name': cs['name'],
+                'system': cs['name'],
+                'tdma': 0,
+                'tgid': cs['tgid'],
+                'tag': cs['name'],
+                'srcaddr': cs['srcaddr'],
+                'srctag': '',
+                'svcopts': 0,
+                'encrypted': 1 if self._encrypted(cs) else 0,
+                'emergency': 0,
+                'hold_tgid': 0,
+                'mode': None,
+                'stream': '',
+                'msgqid': msgq_id,
+                'conventional': True,
+                'voice': cs['voice'],
+                'nac': cs['nac'],
+                'nac_filter': cs['nac_filter'],
+                'algid': cs['algid'],
+                'keyid': cs['keyid'],
+                'enc_calls': cs['enc_calls'],
+                'clear_calls': cs['clear_calls'],
+                'last_enc_algid': cs['last_enc_algid'],
+                'last_enc_keyid': cs['last_enc_keyid'],
+                'last_enc_time': cs['last_enc_time'],
+                'last_clear_time': cs['last_clear_time'],
+                'last_voice_time': cs['last_voice_time'],
+            })
+            d[key] = row
+            if key not in ids:
+                ids.append(key)
+        d['channels'] = ids
+        return json.dumps(d)

op25-container/tests/test_conventional.py

@@ -0,0 +1,305 @@
+"""
+P25 conventional (node-26#24): config generation, the liquidsoap two-channel
+variant, and the tk_drb_conv state machine — all without OP25/GNU Radio.
+
+tk_drb_conv imports tk_p25/helper_funcs/log_ts from OP25's apps dir; those are
+stubbed here with the minimum of tk_p25.rx_ctl it relies on. The message
+shapes fed in are the ones boatbod gr310 p25p1_fdma.cc sends: LCW = 2-byte NAC
++ 9 LC bytes (type 19), LDU2 ESS = JSON (type -3), TDU = 2-byte NAC (type 3/15),
+sync timeout = type -1.
+"""
+import json
+import os
+import sys
+import types
+
+import pytest
+
+HERE = os.path.dirname(__file__)
+sys.path.insert(0, os.path.join(HERE, "..", "app"))
+sys.path.insert(0, os.path.join(HERE, "..", "op25_addons"))
+
+from fastapi.testclient import TestClient  # noqa: E402
+from fastapi import FastAPI  # noqa: E402
+
+from models import ConventionalChannel  # noqa: E402
+from internal import conventional_config as cc  # noqa: E402
+from internal.liquidsoap_config_utils import render_liquid_script  # noqa: E402
+from models import IcecastConfig  # noqa: E402
+
+
+# ---------------------------------------------------------------------------
+# Config generation
+# ---------------------------------------------------------------------------
+
+WP = [
+    ConventionalChannel(frequency=460_400_000, name="PD1 Dispatch"),
+    ConventionalChannel(frequency=460_425_000, name="PD3 Tac", nac=0x293),
+]
+
+
+def test_white_plains_two_channels_one_sdr():
+    config, two = cc.build_conventional_config("White Plains", WP, "lna:34", 0.0)
+    assert two is True
+    assert "trunking" in config and config["trunking"]["module"] == "tk_drb_conv.py"
+    assert config["trunking"]["chans"] == []          # nothing for tk_p25 to hunt
+    a, b = config["channels"]
+    for ch in (a, b):
+        assert ch["demod_type"] == "fsk4"
+        assert ch["trunking_sysname"] == ""
+        assert ch["enable_analog"] == "off"
+        assert ch["crypt_behavior"] == 2
+        assert "control_channel_list" not in ch
+    assert (a["frequency"], b["frequency"]) == (460_400_000, 460_425_000)
+    assert a["destination"].endswith(":23456") and b["destination"].endswith(":23457")
+    assert a["name"] == "PD1 Dispatch" and b["nac"] == 0x293
+    dev = config["devices"][0]
+    assert dev["tunable"] is False
+    # 25 kHz apart: centre is offset off both channels (DC spike), and both
+    # still sit inside the usable passband.
+    half = dev["rate"] * dev["usable_bw_pct"] / 2
+    for f in (460_400_000, 460_425_000):
+        assert 100_000 < abs(f - dev["frequency"]) < half
+
+
+def test_single_channel_is_not_two_channel_audio():
+    config, two = cc.build_conventional_config("X", WP[:1], "lna:34", 0.0)
+    assert two is False
+    assert len(config["channels"]) == 1
+
+
+def test_wide_pair_centres_between_channels():
+    chans = [ConventionalChannel(frequency=453_000_000), ConventionalChannel(frequency=454_000_000)]
+    config, _ = cc.build_conventional_config("X", chans, "lna:34", 0.0)
+    assert config["devices"][0]["frequency"] == 453_500_000
+
+
+@pytest.mark.parametrize("chans, needle", [
+    ([], "at least one"),
+    ([ConventionalChannel(frequency=f) for f in (460_000_000, 460_025_000, 460_050_000)], "up to 2"),
+    ([ConventionalChannel(frequency=460_000_000), ConventionalChannel(frequency=462_000_000)], "too far"),
+    ([ConventionalChannel(frequency=460_000_000), ConventionalChannel(frequency=460_000_000)], "twice"),
+    ([ConventionalChannel(frequency=460_000_000, nac=0x1000)], "NAC"),
+])
+def test_rejects_bad_channel_sets(chans, needle):
+    with pytest.raises(ValueError, match=needle):
+        cc.build_conventional_config("X", chans, "lna:34", 0.0)
+
+
+ICE = IcecastConfig(icecast_host="localhost", icecast_port=8000, icecast_mountpoint="/n", icecast_password="p")
+
+
+def test_liquidsoap_single_channel_unchanged_command():
+    liq = render_liquid_script(ICE, two_channel=False)
+    assert '"./audio.py -x 2.5 -s"' in liq
+    assert "amplify" not in liq and "${" not in liq
+
+
+def test_liquidsoap_two_channel():
+    liq = render_liquid_script(ICE, two_channel=True)
+    assert '"./audio.py -x 2.5 -s -2"' in liq
+    assert "input = amplify(2.0, input)" in liq
+    assert "${" not in liq
+
+
+def test_generate_config_route(tmp_path, monkeypatch):
+    from routers import op25_controller
+    monkeypatch.setattr(op25_controller, "_ACTIVE_CFG", str(tmp_path / "active.cfg.json"))
+    written = {}
+    monkeypatch.setattr(op25_controller, "generate_liquid_script",
+                        lambda ice, two_channel=False: written.setdefault("two", two_channel))
+    monkeypatch.setattr(op25_controller, "save_talkgroup_tags", lambda tags: None)
+    monkeypatch.setattr(op25_controller, "save_whitelist", lambda wl: None)
+    app = FastAPI()
+    app.include_router(op25_controller.create_op25_router(), prefix="/op25")
+    client = TestClient(app)
+    ice = ICE.model_dump()
+    r = client.post("/op25/generate-config", json={
+        "type": "P25", "systemName": "White Plains", "p25_mode": "conventional",
+        "conv_channels": [{"frequency": 460400000, "name": "PD1"}, {"frequency": 460425000, "name": "PD3"}],
+        "icecastConfig": ice,
+    })
+    assert r.status_code == 200, r.text
+    cfg = json.loads((tmp_path / "active.cfg.json").read_text())
+    assert cfg["trunking"]["module"] == "tk_drb_conv.py"
+    assert [c["frequency"] for c in cfg["channels"]] == [460400000, 460425000]
+    assert written["two"] is True
+
+    # Trunked P25 without p25_mode is exactly what it was.
+    r = client.post("/op25/generate-config", json={
+        "type": "P25", "systemName": "County", "channels": [851012500], "icecastConfig": ice,
+    })
+    assert r.status_code == 200, r.text
+    cfg = json.loads((tmp_path / "active.cfg.json").read_text())
+    assert cfg["trunking"]["module"] == "tk_p25.py"
+    assert cfg["trunking"]["chans"][0]["control_channel_list"] == "851012500"
+    assert cfg["channels"][0]["demod_type"] == "cqpsk"
+
+    r = client.post("/op25/generate-config", json={
+        "type": "P25", "systemName": "X", "p25_mode": "conventional", "conv_channels": [],
+    })
+    assert r.status_code == 400
+
+    # Analog uses the same module, so the edge node sees a `conventional` row
+    # whatever tk_p25 the image was built with (node-26#20).
+    r = client.post("/op25/generate-config", json={
+        "type": "NBFM", "systemName": "Fire", "channels": [154430000], "icecastConfig": ice,
+    })
+    assert r.status_code == 200, r.text
+    cfg = json.loads((tmp_path / "active.cfg.json").read_text())
+    assert cfg["trunking"]["module"] == "tk_drb_conv.py"
+    assert cfg["channels"][0]["frequency"] == 154430000
+
+
+# ---------------------------------------------------------------------------
+# tk_drb_conv state machine
+# ---------------------------------------------------------------------------
+
+class _BaseRxCtl:
+    """The slice of tk_p25.rx_ctl that tk_drb_conv relies on."""
+
+    def __init__(self, debug=0, frequency_set=None, nbfm_ctrl=None, fa_ctrl=None, chans={}):
+        self.fa_ctrl = fa_ctrl
+        self.receivers = {}
+        self.call_log = []
+
+    def add_receiver(self, msgq_id, config, meta_q=None, freq=0):
+        self.receivers[msgq_id] = {'msgq_id': msgq_id, 'config': config, 'rx_rcvr': None,
+                                   'conv_state': {'tgid': None}}
+
+    def post_init(self):
+        pass
+
+    def process_qmsg(self, msg):
+        self.base_saw = msg
+
+    def log_call(self, sysid, rcvr, freq, slot, prio, tgid, tgtag, rid, rtag):
+        self.call_log.append({"rcvr": rcvr, "freq": freq, "tgid": tgid, "tgtag": tgtag, "rid": rid})
+
+    def get_chan_status(self):
+        return json.dumps({'json_type': 'channel_update', 'channels': []})
+
+
+def _stub_op25_modules():
+    tk = types.ModuleType("tk_p25")
+    tk.rx_ctl = _BaseRxCtl
+    hf = types.ModuleType("helper_funcs")
+
+    def from_dict(d, key, def_val):
+        return d[key] if key in d and d[key] != "" else def_val
+
+    def get_ordinals(s):
+        t = 0
+        for c in s:
+            t = (t << 8) + c
+        return t
+    hf.from_dict = from_dict
+    hf.get_ordinals = get_ordinals
+    lt = types.ModuleType("log_ts")
+    lt.log_ts = types.SimpleNamespace(get=lambda *a: "ts")
+    sys.modules.update({"tk_p25": tk, "helper_funcs": hf, "log_ts": lt})
+
+
+class _Msg:
+    def __init__(self, m_type, rxid, payload=b""):
+        self._type = m_type & 0xffff   # proto 0 in the upper 16 bits
+        self._arg1 = rxid << 1
+        self._payload = payload
+
+    def type(self):
+        return self._type
+
+    def arg1(self):
+        return self._arg1
+
+    def to_string(self):
+        return self._payload
+
+
+def _lcw(nac, tgid, src, svcopts=0, lco=0x00):
+    lc = bytes([lco, 0x00, svcopts, 0x00]) + tgid.to_bytes(2, "big") + src.to_bytes(3, "big")
+    return nac.to_bytes(2, "big") + lc
+
+
+def _ess(encrypted, algid, keyid):
+    return json.dumps({"encrypted": encrypted, "algid": algid, "keyid": keyid}).encode()
+
+
+@pytest.fixture
+def tk():
+    _stub_op25_modules()
+    sys.modules.pop("tk_drb_conv", None)
+    import tk_drb_conv
+    sent = []
+    rx = tk_drb_conv.rx_ctl(fa_ctrl=sent.append, chans=[])
+    rx.add_receiver(0, {"name": "PD1 Dispatch", "nac": 0x293}, freq=460_400_000)
+    rx.add_receiver(1, {"name": "PD3 Tac"}, freq=460_425_000)
+    rx.post_init()
+    rx.sent = sent
+    return rx
+
+
+def _rows(rx):
+    d = json.loads(rx.get_chan_status())
+    return {cid: d[cid] for cid in d["channels"]}
+
+
+def test_nac_filter_applied_only_where_configured(tk):
+    assert tk.sent == [{'tuner': 0, 'cmd': 'set_nac', 'nac': 0x293}]
+
+
+def test_clear_call_reports_tgid_unit_nac_and_logs_once(tk):
+    tk.process_qmsg(_Msg(0, 0, b"\x02\x93"))                       # HDU
+    tk.process_qmsg(_Msg(19, 0, _lcw(0x293, 101, 4242)))            # LDU1
+    tk.process_qmsg(_Msg(-3, 0, _ess(0, 0x80, 0)))                  # LDU2 clear
+    tk.process_qmsg(_Msg(19, 0, _lcw(0x293, 101, 4242)))
+    row = _rows(tk)["0"]
+    assert row["conventional"] and row["voice"]
+    assert (row["tgid"], row["srcaddr"], row["nac"], row["encrypted"]) == (101, 4242, 0x293, 0)
+    assert row["algid"] is None
+    assert [e["tgid"] for e in tk.call_log] == [101]
+    assert tk.call_log[0]["tgtag"] == "PD1 Dispatch"
+    # The other channel is idle.
+    assert _rows(tk)["1"]["voice"] is False
+
+    tk.process_qmsg(_Msg(3, 0, b"\x02\x93"))                         # TDU
+    row = _rows(tk)["0"]
+    assert row["voice"] is False and row["tgid"] is None
+    assert (row["clear_calls"], row["enc_calls"]) == (1, 0)
+
+
+def test_tdulc_link_control_does_not_reopen_the_call(tk):
+    tk.process_qmsg(_Msg(19, 1, _lcw(0x111, 7, 9)))
+    tk.process_qmsg(_Msg(15, 1, b"\x01\x11"))                        # TDULC
+    tk.process_qmsg(_Msg(19, 1, _lcw(0x111, 7, 9)))                 # its LC
+    assert _rows(tk)["1"]["voice"] is False
+
+
+def test_encrypted_call_is_reported_and_never_logged(tk):
+    tk.process_qmsg(_Msg(19, 1, _lcw(0x111, 7, 9, svcopts=0x40)))  # E bit
+    tk.process_qmsg(_Msg(-3, 1, _ess(1, 0x84, 0x1234)))
+    row = _rows(tk)["1"]
+    assert row["encrypted"] == 1 and row["algid"] == 0x84 and row["keyid"] == 0x1234
+    assert tk.call_log == []
+    tk.process_qmsg(_Msg(-1, 1))                                    # sync timeout
+    row = _rows(tk)["1"]
+    assert row["encrypted"] == 0 and row["voice"] is False
+    assert (row["enc_calls"], row["last_enc_algid"], row["last_enc_keyid"]) == (1, 0x84, 0x1234)
+
+
+def test_encryption_seen_only_in_ess_still_counts(tk):
+    tk.process_qmsg(_Msg(-3, 0, _ess(1, 0x81, 0x0001)))
+    assert _rows(tk)["0"]["encrypted"] == 1
+    tk.process_qmsg(_Msg(3, 0, b"\x02\x93"))
+    assert _rows(tk)["0"]["enc_calls"] == 1
+
+
+def test_protected_link_control_marks_encrypted(tk):
+    tk.process_qmsg(_Msg(19, 0, _lcw(0x293, 0, 0, lco=0x80)))
+    assert _rows(tk)["0"]["encrypted"] == 1
+
+
+def test_trunked_receivers_and_other_protocols_go_to_base(tk):
+    msg = _Msg(7, 5)
+    tk.process_qmsg(msg)
+    assert tk.base_saw is msg