voice receive support (#101)

* initial voice

* some updates

fixed it

* some style updates

replaced the speaking when joining with an actual client_connect event

* please pass

* replaced channel with client in VoiceData and VoiceSpeaking events

Also changed some voice sending stuff

* added more debug logs

* fixed version not being set on the voice gateway

disco/voice/client.py

@@ -3,6 +3,8 @@ from __future__ import print_function
 import gevent
 import time
 
+from collections import namedtuple
+
 from holster.enum import Enum
 from holster.emitter import Emitter
 
@@ -11,7 +13,13 @@ from disco.util.websocket import Websocket
 from disco.util.logging import LoggingClass
 from disco.gateway.packets import OPCode
 from disco.voice.packets import VoiceOPCode
-from disco.voice.udp import UDPVoiceClient
+from disco.voice.udp import AudioCodecs, PayloadTypes, UDPVoiceClient
+
+SpeakingCodes = Enum(
+    NONE=0,
+    VOICE=1 << 0,
+    SOUNDSHARE=1 << 1,
+)
 
 VoiceState = Enum(
     DISCONNECTED=0,
@@ -25,6 +33,13 @@ VoiceState = Enum(
     VOICE_CONNECTED=8,
 )
 
+VoiceSpeaking = namedtuple('VoiceSpeaking', [
+    'client',
+    'user_id',
+    'speaking',
+    'soundshare',
+])
+
 
 class VoiceException(Exception):
     def __init__(self, msg, client):
@@ -33,7 +48,7 @@ class VoiceException(Exception):
 
 
 class VoiceClient(LoggingClass):
-    VOICE_GATEWAY_VERSION = 3
+    VOICE_GATEWAY_VERSION = 4
 
     SUPPORTED_MODES = {
         'xsalsa20_poly1305_lite',
@@ -58,6 +73,10 @@ class VoiceClient(LoggingClass):
         self.packets.on(VoiceOPCode.READY, self.on_voice_ready)
         self.packets.on(VoiceOPCode.RESUMED, self.on_voice_resumed)
         self.packets.on(VoiceOPCode.SESSION_DESCRIPTION, self.on_voice_sdp)
+        self.packets.on(VoiceOPCode.SPEAKING, self.on_voice_speaking)
+        self.packets.on(VoiceOPCode.CLIENT_CONNECT, self.on_voice_client_connect)
+        self.packets.on(VoiceOPCode.CLIENT_DISCONNECT, self.on_voice_client_disconnect)
+        self.packets.on(VoiceOPCode.CODECS, self.on_voice_codecs)
 
         # State + state change emitter
         self.state = VoiceState.DISCONNECTED
@@ -71,6 +90,9 @@ class VoiceClient(LoggingClass):
         self.port = None
         self.mode = None
         self.udp = None
+        self.audio_codec = None
+        self.video_codec = None
+        self.transport_id = None
 
         # Websocket connection
         self.ws = None
@@ -80,6 +102,9 @@ class VoiceClient(LoggingClass):
         self._update_listener = None
         self._heartbeat_task = None
 
+        # SSRCs
+        self.audio_ssrcs = {}
+
     def __repr__(self):
         return u'<VoiceClient {}>'.format(self.channel)
 
@@ -90,7 +115,7 @@ class VoiceClient(LoggingClass):
         self.state_emitter.emit(state, prev_state)
 
     def _connect_and_run(self):
-        self.ws = Websocket('wss://' + self.endpoint + '/v={}'.format(self.VOICE_GATEWAY_VERSION))
+        self.ws = Websocket('wss://' + self.endpoint + '/?v={}'.format(self.VOICE_GATEWAY_VERSION))
         self.ws.emitter.on('on_open', self.on_open)
         self.ws.emitter.on('on_error', self.on_error)
         self.ws.emitter.on('on_close', self.on_close)
@@ -102,10 +127,17 @@ class VoiceClient(LoggingClass):
             self.send(VoiceOPCode.HEARTBEAT, time.time())
             gevent.sleep(interval / 1000)
 
-    def set_speaking(self, value):
+    def set_speaking(self, voice=False, soundshare=False, delay=0):
+        value = SpeakingCodes.NONE.value
+        if voice:
+            value |= SpeakingCodes.VOICE.value
+        if soundshare:
+            value |= SpeakingCodes.SOUNDSHARE.value
+
         self.send(VoiceOPCode.SPEAKING, {
             'speaking': value,
-            'delay': 0,
+            'delay': delay,
+            'ssrc': self.ssrc,
         })
 
     def send(self, op, data):
@@ -115,9 +147,27 @@ class VoiceClient(LoggingClass):
             'd': data,
         }), self.encoder.OPCODE)
 
+    def on_voice_client_connect(self, data):
+        self.audio_ssrcs[data['audio_ssrc']] = data['user_id']
+        # ignore data['voice_ssrc'] for now
+
+    def on_voice_client_disconnect(self, data):
+        for ssrc in self.audio_ssrcs.keys():
+            if self.audio_ssrcs[ssrc] == data['user_id']:
+                del self.audio_ssrcs[ssrc]
+                break
+
+    def on_voice_codecs(self, data):
+        self.audio_codec = data['audio_codec']
+        self.video_codec = data['video_codec']
+        self.transport_id = data['media_session_id']
+
+        # Set the UDP's RTP Audio Header's Payload Type
+        self.udp.set_audio_codec(data['audio_codec'])
+
     def on_voice_hello(self, data):
         self.log.info('[%s] Recieved Voice HELLO payload, starting heartbeater', self)
-        self._heartbeat_task = gevent.spawn(self._heartbeat, data['heartbeat_interval'] * 0.75)
+        self._heartbeat_task = gevent.spawn(self._heartbeat, data['heartbeat_interval'])
         self.set_state(VoiceState.AUTHENTICATED)
 
     def on_voice_ready(self, data):
@@ -144,6 +194,17 @@ class VoiceClient(LoggingClass):
             self.disconnect()
             return
 
+        codecs = []
+
+        # Sending discord our available codecs and rtp payload type for it
+        for idx, codec in enumerate(AudioCodecs):
+            codecs.append({
+                'name': codec,
+                'type': 'audio',
+                'priority': (idx + 1) * 1000,
+                'payload_type': PayloadTypes.get(codec).value,
+            })
+
         self.log.debug('[%s] IP discovery completed (ip = %s, port = %s), sending SELECT_PROTOCOL', self, ip, port)
         self.send(VoiceOPCode.SELECT_PROTOCOL, {
             'protocol': 'udp',
@@ -152,6 +213,12 @@ class VoiceClient(LoggingClass):
                 'address': ip,
                 'mode': self.mode,
             },
+            'codecs': codecs,
+        })
+        self.send(VoiceOPCode.CLIENT_CONNECT, {
+            'audio_ssrc': self.ssrc,
+            'video_ssrc': 0,
+            'rtx_ssrc': 0,
         })
 
     def on_voice_resumed(self, data):
@@ -161,14 +228,17 @@ class VoiceClient(LoggingClass):
     def on_voice_sdp(self, sdp):
         self.log.info('[%s] Recieved session description, connection completed', self)
 
+        self.mode = sdp['mode']
+        self.audio_codec = sdp['audio_codec']
+        self.video_codec = sdp['video_codec']
+        self.transport_id = sdp['media_session_id']
+
+        # Set the UDP's RTP Audio Header's Payload Type
+        self.udp.set_audio_codec(sdp['audio_codec'])
+
         # Create a secret box for encryption/decryption
         self.udp.setup_encryption(bytes(bytearray(sdp['secret_key'])))
 
-        # Toggle speaking state so clients learn of our SSRC
-        self.set_speaking(True)
-        self.set_speaking(False)
-        gevent.sleep(0.25)
-
         self.set_state(VoiceState.CONNECTED)
 
     def on_voice_server_update(self, data):
@@ -187,6 +257,18 @@ class VoiceClient(LoggingClass):
 
         self._connect_and_run()
 
+    def on_voice_speaking(self, data):
+        self.audio_ssrcs[data['ssrc']] = data['user_id']
+
+        payload = VoiceSpeaking(
+            client=self,
+            user_id=data['user_id'],
+            speaking=bool(data['speaking'] & SpeakingCodes.VOICE.value),
+            soundshare=bool(data['speaking'] & SpeakingCodes.SOUNDSHARE.value),
+        )
+
+        self.client.gw.events.emit('VoiceSpeaking', payload)
+
     def on_message(self, msg):
         try:
             data = self.encoder.decode(msg)

disco/voice/packets.py

@@ -11,5 +11,7 @@ VoiceOPCode = Enum(
     RESUME=7,
     HELLO=8,
     RESUMED=9,
+    CLIENT_CONNECT=12,
     CLIENT_DISCONNECT=13,
+    CODECS=14,
 )

disco/voice/udp.py

@@ -2,16 +2,48 @@ import struct
 import socket
 import gevent
 
+from collections import namedtuple
+
 try:
     import nacl.secret
 except ImportError:
     print('WARNING: nacl is not installed, voice support is disabled')
 
+from holster.enum import Enum
+
 from disco.util.logging import LoggingClass
 
+AudioCodecs = ('opus',)
+
+PayloadTypes = Enum(OPUS=0x78)
+
 MAX_UINT32 = 4294967295
 MAX_SEQUENCE = 65535
 
+RTP_HEADER_VERSION = 0x80  # Only RTP Version is set here (value of 2 << 6)
+RTP_EXTENSION_ONE_BYTE = (0xBE, 0xDE)
+
+
+RTPHeader = namedtuple('RTPHeader', [
+    'version',
+    'padding',
+    'extension',
+    'csrc_count',
+    'marker',
+    'payload_type',
+    'sequence',
+    'timestamp',
+    'ssrc',
+])
+
+VoiceData = namedtuple('VoiceData', [
+    'client',
+    'user_id',
+    'payload_type',
+    'rtp',
+    'data',
+])
+
 
 class UDPVoiceClient(LoggingClass):
     def __init__(self, vc):
@@ -34,10 +66,17 @@ class UDPVoiceClient(LoggingClass):
         self._run_task = None
         self._secret_box = None
 
-        # Buffer used for encoding/sending frames
+        # RTP Header
-        self._buffer = bytearray(24)
+        self._rtp_audio_header = bytearray(12)
-        self._buffer[0] = 0x80
+        self._rtp_audio_header[0] = RTP_HEADER_VERSION
-        self._buffer[1] = 0x78
+
+    def set_audio_codec(self, codec):
+        ptype = PayloadTypes.get(codec)
+        if ptype:
+            self._rtp_audio_header[1] = ptype.value
+            self.log.debug('[%s] Set UDP\'s Audio Codec to %s, RTP payload type %s', self.vc, ptype.name, ptype.value)
+        else:
+            raise Exception('The voice codec, {}, isn\'t supported.'.format(codec))
 
     def increment_timestamp(self, by):
         self.timestamp += by
@@ -52,27 +91,40 @@ class UDPVoiceClient(LoggingClass):
         frame = bytearray(frame)
 
         # Pack the rtc header into our buffer
-        struct.pack_into('>H', self._buffer, 2, sequence or self.sequence)
+        struct.pack_into('>H', self._rtp_audio_header, 2, sequence or self.sequence)
-        struct.pack_into('>I', self._buffer, 4, timestamp or self.timestamp)
+        struct.pack_into('>I', self._rtp_audio_header, 4, timestamp or self.timestamp)
-        struct.pack_into('>i', self._buffer, 8, self.vc.ssrc)
+        struct.pack_into('>i', self._rtp_audio_header, 8, self.vc.ssrc)
 
         if self.vc.mode == 'xsalsa20_poly1305_lite':
+            # Use an incrementing number as a nonce, only first 4 bytes of the nonce is padded on
             self._nonce += 1
             if self._nonce > MAX_UINT32:
                 self._nonce = 0
 
             nonce = bytearray(24)
             struct.pack_into('>I', nonce, 0, self._nonce)
-            raw = self._secret_box.encrypt(bytes(frame), nonce).ciphertext + nonce[:4]
+            nonce_padding = nonce[:4]
         elif self.vc.mode == 'xsalsa20_poly1305_suffix':
+            # Generate a nonce
             nonce = nacl.utils.random(nacl.secret.SecretBox.NONCE_SIZE)
-            raw = self._secret_box.encrypt(bytes(frame), nonce).ciphertext + nonce
+            nonce_padding = nonce
+        elif self.vc.mode == 'xsalsa20_poly1305':
+            # Nonce is the header
+            nonce = bytearray(24)
+            nonce[:12] = self._rtp_audio_header
+            nonce_padding = None
         else:
-            # Now encrypt the payload with the nonce as a header
+            raise Exception('The voice mode, {}, isn\'t supported.'.format(self.vc.mode))
-            raw = self._secret_box.encrypt(bytes(frame), bytes(self._buffer)).ciphertext
+
+        # Encrypt the payload with the nonce
+        payload = self._secret_box.encrypt(bytes(frame), bytes(nonce)).ciphertext
+
+        # Pad the payload with the nonce, if applicable
+        if nonce_padding:
+            payload += nonce_padding
 
         # Send the header (sans nonce padding) plus the payload
-        self.send(self._buffer[:12] + raw)
+        self.send(self._rtp_audio_header + payload)
 
         # Increment our sequence counter
         self.sequence += 1
@@ -85,7 +137,111 @@ class UDPVoiceClient(LoggingClass):
 
     def run(self):
         while True:
-            self.conn.recvfrom(4096)
+            data, addr = self.conn.recvfrom(4096)
+
+            # Data cannot be less than the bare minimum, just ignore
+            if len(data) <= 12:
+                self.log.debug('[%s] [VoiceData] Received voice data under 13 bytes', self.vc)
+                continue
+
+            first, second, sequence, timestamp, ssrc = struct.unpack_from('>BBHII', data)
+
+            rtp = RTPHeader(
+                version=first >> 6,
+                padding=(first >> 5) & 1,
+                extension=(first >> 4) & 1,
+                csrc_count=first & 0x0F,
+                marker=second >> 7,
+                payload_type=second & 0x7F,
+                sequence=sequence,
+                timestamp=timestamp,
+                ssrc=ssrc,
+            )
+
+            # Check if rtp version is 2
+            if rtp.version != 2:
+                self.log.debug('[%s] [VoiceData] Received an invalid RTP packet version, %s', self.vc, rtp.version)
+                continue
+
+            payload_type = PayloadTypes.get(rtp.payload_type)
+
+            # Unsupported payload type received
+            if not payload_type:
+                self.log.debug('[%s] [VoiceData] Received unsupported payload type, %s', self.vc, rtp.payload_type)
+                continue
+
+            nonce = bytearray(24)
+            if self.vc.mode == 'xsalsa20_poly1305_lite':
+                nonce[:4] = data[-4:]
+                data = data[:-4]
+            elif self.vc.mode == 'xsalsa20_poly1305_suffx':
+                nonce[:24] = data[-24:]
+                data = data[:-24]
+            elif self.vc.mode == 'xsalsa20_poly1305':
+                nonce[:12] = data[:12]
+            else:
+                self.log.debug('[%s] [VoiceData] Unsupported Encryption Mode, %s', self.vc, self.vc.mode)
+                continue
+
+            try:
+                data = self._secret_box.decrypt(bytes(data[12:]), bytes(nonce))
+            except Exception:
+                self.log.debug('[%s] [VoiceData] Failed to decode data from ssrc %s', self.vc, rtp.ssrc)
+                continue
+
+            # RFC3550 Section 5.1 (Padding)
+            if rtp.padding:
+                padding_amount, = struct.unpack_from('>B', data[:-1])
+                data = data[-padding_amount:]
+
+            if rtp.extension:
+                # RFC5285 Section 4.2: One-Byte Header
+                rtp_extension_header = struct.unpack_from('>BB', data)
+                if rtp_extension_header == RTP_EXTENSION_ONE_BYTE:
+                    data = data[2:]
+
+                    fields_amount, = struct.unpack_from('>H', data)
+                    fields = []
+
+                    offset = 4
+                    for i in range(fields_amount):
+                        first_byte, = struct.unpack_from('>B', data[offset])
+                        offset += 1
+
+                        rtp_extension_identifer = first_byte & 0xF
+                        rtp_extension_len = ((first_byte >> 4) & 0xF) + 1
+
+                        # Ignore data if identifer == 15, so skip if this is set as 0
+                        if rtp_extension_identifer:
+                            fields.append(data[offset:offset + rtp_extension_len])
+
+                        offset += rtp_extension_len
+
+                        # skip padding
+                        while data[offset] == 0:
+                            offset += 1
+
+                    if len(fields):
+                        fields.append(data[offset:])
+                        data = b''.join(fields)
+                    else:
+                        data = data[offset:]
+
+            # RFC3550 Section 5.3: Profile-Specific Modifications to the RTP Header
+            # clients send it sometimes, definitely on fresh connects to a server, dunno what to do here
+            if rtp.marker:
+                self.log.debug('[%s] [VoiceData] Received RTP data with the marker set, skipping', self.vc)
+                continue
+
+            payload = VoiceData(
+                client=self.vc,
+                payload_type=payload_type.name,
+                user_id=self.vc.audio_ssrcs.get(rtp.ssrc, None),
+                rtp=rtp,
+                data=data,
+            )
+
+            self.vc.client.gw.events.emit('VoiceData', payload)
 
     def send(self, data):
         self.conn.sendto(data, (self.ip, self.port))