Make bind() optional and implement a generator for device discovery (#427)

broadlink/__init__.py

@@ -1,15 +1,13 @@
 #!/usr/bin/python3
 """The python-broadlink library."""
 import socket
-import time
-from datetime import datetime
 from typing import Dict, List, Union, Tuple, Type
 
 from .alarm import S1C
 from .climate import hysen
 from .cover import dooya
-from .device import device
-from .helpers import get_local_ip
+from .device import device, scan
+from .exceptions import exception
 from .light import lb1
 from .remote import rm, rm2, rm4
 from .sensor import a1
@@ -95,11 +93,11 @@ def get_devices() -> Dict[int, Tuple[Type[device], str, str]]:
 
 
 def gendevice(
-    dev_type: int,
-    host: Tuple[str, int],
-    mac: Union[bytes, str],
-    name: str = None,
-    is_locked: bool = None,
+        dev_type: int,
+        host: Tuple[str, int],
+        mac: Union[bytes, str],
+        name: str = None,
+        is_locked: bool = None,
 ) -> device:
     """Generate a device."""
     try:
@@ -119,91 +117,50 @@ def gendevice(
     )
 
 
+def hello(
+        host: str,
+        port: int = 80,
+        timeout: int = 10,
+        local_ip_address: str = None,
+) -> device:
+    """Direct device discovery.
+
+    Useful if the device is locked.
+    """
+    try:
+        return next(xdiscover(timeout, local_ip_address, host, port))
+    except StopIteration:
+        raise exception(-4000)  # Network timeout.
+
+
 def discover(
-        timeout: int = None,
+        timeout: int = 10,
         local_ip_address: str = None,
         discover_ip_address: str = '255.255.255.255',
         discover_ip_port: int = 80,
 ) -> List[device]:
     """Discover devices connected to the local network."""
-    local_ip_address = local_ip_address or get_local_ip()
-    address = local_ip_address.split('.')
-    cs = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
-    cs.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
-    cs.setsockopt(socket.SOL_SOCKET, socket.SO_BROADCAST, 1)
-    cs.bind((local_ip_address, 0))
-    port = cs.getsockname()[1]
-    starttime = time.time()
+    responses = scan(
+        timeout, local_ip_address, discover_ip_address, discover_ip_port
+    )
+    return [gendevice(*resp) for resp in responses]
 
-    devices = []
 
-    timezone = int(time.timezone / -3600)
-    packet = bytearray(0x30)
+def xdiscover(
+        timeout: int = 10,
+        local_ip_address: str = None,
+        discover_ip_address: str = '255.255.255.255',
+        discover_ip_port: int = 80,
+) -> Generator[device, None, None]:
+    """Discover devices connected to the local network.
 
-    year = datetime.now().year
-
-    if timezone < 0:
-        packet[0x08] = 0xff + timezone - 1
-        packet[0x09] = 0xff
-        packet[0x0a] = 0xff
-        packet[0x0b] = 0xff
-    else:
-        packet[0x08] = timezone
-        packet[0x09] = 0
-        packet[0x0a] = 0
-        packet[0x0b] = 0
-
-    packet[0x0c] = year & 0xff
-    packet[0x0d] = year >> 8
-    packet[0x0e] = datetime.now().minute
-    packet[0x0f] = datetime.now().hour
-    subyear = str(year)[2:]
-    packet[0x10] = int(subyear)
-    packet[0x11] = datetime.now().isoweekday()
-    packet[0x12] = datetime.now().day
-    packet[0x13] = datetime.now().month
-    packet[0x18] = int(address[0])
-    packet[0x19] = int(address[1])
-    packet[0x1a] = int(address[2])
-    packet[0x1b] = int(address[3])
-    packet[0x1c] = port & 0xff
-    packet[0x1d] = port >> 8
-    packet[0x26] = 6
-
-    checksum = sum(packet, 0xbeaf) & 0xffff
-    packet[0x20] = checksum & 0xff
-    packet[0x21] = checksum >> 8
-
-    cs.sendto(packet, (discover_ip_address, discover_ip_port))
-    if timeout is None:
-        response = cs.recvfrom(1024)
-        responsepacket = bytearray(response[0])
-        host = response[1]
-        devtype = responsepacket[0x34] | responsepacket[0x35] << 8
-        mac = responsepacket[0x3f:0x39:-1]
-        name = responsepacket[0x40:].split(b'\x00')[0].decode('utf-8')
-        is_locked = bool(responsepacket[-1])
-        device = gendevice(devtype, host, mac, name=name, is_locked=is_locked)
-        cs.close()
-        return device
-
-    while (time.time() - starttime) < timeout:
-        cs.settimeout(timeout - (time.time() - starttime))
-        try:
-            response = cs.recvfrom(1024)
-        except socket.timeout:
-            cs.close()
-            return devices
-        responsepacket = bytearray(response[0])
-        host = response[1]
-        devtype = responsepacket[0x34] | responsepacket[0x35] << 8
-        mac = responsepacket[0x3f:0x39:-1]
-        name = responsepacket[0x40:].split(b'\x00')[0].decode('utf-8')
-        is_locked = bool(responsepacket[-1])
-        device = gendevice(devtype, host, mac, name=name, is_locked=is_locked)
-        devices.append(device)
-    cs.close()
-    return devices
+    This function returns a generator that yields devices instantly.
+    """
+    responses = scan(
+        timeout, local_ip_address, discover_ip_address, discover_ip_port
+    )
+    for resp in responses:
+        yield gendevice(*resp)
 
 
 # Setup a new Broadlink device via AP Mode. Review the README to see how to enter AP Mode.

broadlink/device.py

@@ -2,13 +2,93 @@ import socket
 import threading
 import random
 import time
-from typing import Tuple, Union
+from datetime import datetime
+from typing import Generator, Tuple, Union
 
 from cryptography.hazmat.backends import default_backend
 from cryptography.hazmat.primitives.ciphers import Cipher, algorithms, modes
 
 from .exceptions import check_error, exception
 
+HelloResponse = Tuple[int, Tuple[str, int], str, str, bool]
+
+
+def scan(
+        timeout: int = 10,
+        local_ip_address: str = None,
+        discover_ip_address: str = '255.255.255.255',
+        discover_ip_port: int = 80,
+) -> Generator[HelloResponse, None, None]:
+    """Broadcast a hello message and yield responses."""
+    cs = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+    cs.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+    cs.setsockopt(socket.SOL_SOCKET, socket.SO_BROADCAST, 1)
+
+    if local_ip_address:
+        cs.bind((local_ip_address, 0))
+        port = cs.getsockname()[1]
+    else:
+        local_ip_address = "0.0.0.0"
+        port = 0
+
+    address = local_ip_address.split('.')
+    starttime = time.time()
+
+    timezone = int(time.timezone / -3600)
+    packet = bytearray(0x30)
+
+    year = datetime.now().year
+
+    if timezone < 0:
+        packet[0x08] = 0xff + timezone - 1
+        packet[0x09] = 0xff
+        packet[0x0a] = 0xff
+        packet[0x0b] = 0xff
+    else:
+        packet[0x08] = timezone
+        packet[0x09] = 0
+        packet[0x0a] = 0
+        packet[0x0b] = 0
+
+    packet[0x0c] = year & 0xff
+    packet[0x0d] = year >> 8
+    packet[0x0e] = datetime.now().minute
+    packet[0x0f] = datetime.now().hour
+    subyear = str(year)[2:]
+    packet[0x10] = int(subyear)
+    packet[0x11] = datetime.now().isoweekday()
+    packet[0x12] = datetime.now().day
+    packet[0x13] = datetime.now().month
+    packet[0x18] = int(address[3])
+    packet[0x19] = int(address[2])
+    packet[0x1a] = int(address[1])
+    packet[0x1b] = int(address[0])
+    packet[0x1c] = port & 0xff
+    packet[0x1d] = port >> 8
+    packet[0x26] = 6
+
+    checksum = sum(packet, 0xbeaf) & 0xffff
+    packet[0x20] = checksum & 0xff
+    packet[0x21] = checksum >> 8
+
+    cs.sendto(packet, (discover_ip_address, discover_ip_port))
+
+    try:
+        while (time.time() - starttime) < timeout:
+            cs.settimeout(timeout - (time.time() - starttime))
+            try:
+                response, host = cs.recvfrom(1024)
+            except socket.timeout:
+                break
+
+            devtype = response[0x34] | response[0x35] << 8
+            mac = bytes(reversed(response[0x3a:0x40]))
+            name = response[0x40:].split(b'\x00')[0].decode('utf-8')
+            is_locked = bool(response[-1])
+            yield devtype, host, mac, name, is_locked
+    finally:
+        cs.close()
+
 
 class device:
     """Controls a Broadlink device."""
@@ -101,6 +181,29 @@ class device:
         self.update_aes(key)
         return True
 
+    def hello(self, local_ip_address=None) -> bool:
+        """Send a hello message to the device.
+
+        Device information is checked before updating name and lock status.
+        """
+        responses = scan(
+            timeout=self.timeout,
+            local_ip_address=local_ip_address,
+            discover_ip_address=self.host[0],
+            discover_ip_port=self.host[1],
+        )
+        try:
+            devtype, host, mac, name, is_locked = next(responses)
+        except StopIteration:
+            raise exception(-4000)  # Network timeout.
+
+        if (devtype, host, mac) != (self.devtype, self.host, self.mac):
+            raise exception(-2040)  # Device information is not intact.
+
+        self.name = name
+        self.is_locked = is_locked
+        return True
+
     def get_fwversion(self) -> int:
         """Get firmware version."""
         packet = bytearray([0x68])

broadlink/exceptions.py

@@ -80,6 +80,10 @@ class SDKException(BroadlinkException):
     """Common base class for all SDK exceptions."""
 
 
+class DeviceInformationError(SDKException):
+    """Device information is not intact."""
+
+
 class ChecksumError(SDKException):
     """Received data packet check error."""
 
@@ -88,10 +92,6 @@ class LengthError(SDKException):
     """Received data packet length error."""
 
 
-class DNSLookupError(SDKException):
-    """Failed to obtain local IP address."""
-
-
 class NetworkTimeoutError(SDKException):
     """Network timeout error."""
 
@@ -113,11 +113,11 @@ BROADLINK_EXCEPTIONS = {
     -9: (WriteError, "Write error"),
     -10: (ReadError, "Read error"),
     -11: (SSIDNotFoundError, "SSID could not be found in AP configuration"),
-    # DNASDK related errors are generated by this module.
+    # SDK related errors are generated by this module.
+    -2040: (DeviceInformationError, "Device information is not intact"),
     -4000: (NetworkTimeoutError, "Network timeout"),
     -4007: (LengthError, "Received data packet length error"),
     -4008: (ChecksumError, "Received data packet check error"),
-    -4013: (DNSLookupError, "Failed to obtain local IP address"),
 }
 
 

broadlink/helpers.py

@@ -1,24 +1,5 @@
 """Helper functions."""
 from ctypes import c_ushort
-import socket
-
-from .exceptions import exception
-
-
-def get_local_ip() -> str:
-    """Try to determine the local IP address of the machine."""
-    # Useful for VPNs.
-    try:
-        local_ip_address = socket.gethostbyname(socket.gethostname())
-        if not local_ip_address.startswith('127.'):
-            return local_ip_address
-    except socket.gaierror:
-        raise exception(-4013)  # DNS Error
-
-    # Connecting to UDP address does not send packets.
-    with socket.socket(socket.AF_INET, socket.SOCK_DGRAM) as s:
-        s.connect(('8.8.8.8', 53))
-        return s.getsockname()[0]
 
 
 def calculate_crc16(input_data: bytes) -> int: