Move to use zeroconf library instead of inline copy (#2192)

This commit is contained in:
Jesse Hills 2021-09-06 08:22:15 +12:00 committed by GitHub
parent 77508f7e44
commit ca12b8aa56
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GPG key ID: 4AEE18F83AFDEB23
3 changed files with 53 additions and 727 deletions

View file

@ -41,7 +41,7 @@ from .util import password_hash
# pylint: disable=unused-import, wrong-import-order
from typing import Optional # noqa
from esphome.zeroconf import DashboardStatus, Zeroconf
from esphome.zeroconf import DashboardStatus, EsphomeZeroconf
_LOGGER = logging.getLogger(__name__)
@ -501,7 +501,7 @@ def _ping_func(filename, address):
class MDNSStatusThread(threading.Thread):
def run(self):
zc = Zeroconf()
zc = EsphomeZeroconf()
def on_update(dat):
for key, b in dat.items():

View file

@ -97,10 +97,10 @@ def is_ip_address(host):
def _resolve_with_zeroconf(host):
from esphome.core import EsphomeError
from esphome.zeroconf import Zeroconf
from esphome.zeroconf import EsphomeZeroconf
try:
zc = Zeroconf()
zc = EsphomeZeroconf()
except Exception as err:
raise EsphomeError(
"Cannot start mDNS sockets, is this a docker container without "

View file

@ -1,520 +1,27 @@
# Custom zeroconf implementation based on python-zeroconf
# (https://github.com/jstasiak/python-zeroconf) that supports Python 2
import errno
import logging
import select
import socket
import struct
import sys
import threading
import time
from typing import Optional
import ifaddr
log = logging.getLogger(__name__)
# Some timing constants
_LISTENER_TIME = 200
# Some DNS constants
_MDNS_ADDR = "224.0.0.251"
_MDNS_PORT = 5353
_MAX_MSG_ABSOLUTE = 8966
_FLAGS_QR_MASK = 0x8000 # query response mask
_FLAGS_QR_QUERY = 0x0000 # query
_FLAGS_QR_RESPONSE = 0x8000 # response
_FLAGS_AA = 0x0400 # Authoritative answer
_FLAGS_TC = 0x0200 # Truncated
_FLAGS_RD = 0x0100 # Recursion desired
_FLAGS_RA = 0x8000 # Recursion available
_FLAGS_Z = 0x0040 # Zero
_FLAGS_AD = 0x0020 # Authentic data
_FLAGS_CD = 0x0010 # Checking disabled
_CLASS_IN = 1
_CLASS_CS = 2
_CLASS_CH = 3
_CLASS_HS = 4
_CLASS_NONE = 254
_CLASS_ANY = 255
_CLASS_MASK = 0x7FFF
_CLASS_UNIQUE = 0x8000
_TYPE_A = 1
_TYPE_NS = 2
_TYPE_MD = 3
_TYPE_MF = 4
_TYPE_CNAME = 5
_TYPE_SOA = 6
_TYPE_MB = 7
_TYPE_MG = 8
_TYPE_MR = 9
_TYPE_NULL = 10
_TYPE_WKS = 11
_TYPE_PTR = 12
_TYPE_HINFO = 13
_TYPE_MINFO = 14
_TYPE_MX = 15
_TYPE_TXT = 16
_TYPE_AAAA = 28
_TYPE_SRV = 33
_TYPE_ANY = 255
# Mapping constants to names
int2byte = struct.Struct(">B").pack
# Exceptions
class Error(Exception):
pass
class IncomingDecodeError(Error):
pass
# pylint: disable=no-init
class QuietLogger:
_seen_logs = {}
@classmethod
def log_exception_warning(cls, logger_data=None):
exc_info = sys.exc_info()
exc_str = str(exc_info[1])
if exc_str not in cls._seen_logs:
# log at warning level the first time this is seen
cls._seen_logs[exc_str] = exc_info
logger = log.warning
else:
logger = log.debug
if logger_data is not None:
logger(*logger_data)
logger("Exception occurred:", exc_info=True)
@classmethod
def log_warning_once(cls, *args):
msg_str = args[0]
if msg_str not in cls._seen_logs:
cls._seen_logs[msg_str] = 0
logger = log.warning
else:
logger = log.debug
cls._seen_logs[msg_str] += 1
logger(*args)
class DNSEntry:
"""A DNS entry"""
def __init__(self, name, type_, class_):
self.key = name.lower()
self.name = name
self.type = type_
self.class_ = class_ & _CLASS_MASK
self.unique = (class_ & _CLASS_UNIQUE) != 0
class DNSQuestion(DNSEntry):
"""A DNS question entry"""
def __init__(self, name, type_, class_):
DNSEntry.__init__(self, name, type_, class_)
def answered_by(self, rec):
"""Returns true if the question is answered by the record"""
return (
self.class_ == rec.class_
and (self.type == rec.type or self.type == _TYPE_ANY)
and self.name == rec.name
from zeroconf import (
_CLASS_IN,
_FLAGS_QR_QUERY,
_TYPE_A,
DNSAddress,
DNSOutgoing,
DNSRecord,
DNSQuestion,
RecordUpdateListener,
Zeroconf,
)
class DNSRecord(DNSEntry):
"""A DNS record - like a DNS entry, but has a TTL"""
def __init__(self, name, type_, class_, ttl):
DNSEntry.__init__(self, name, type_, class_)
self.ttl = 15
self.created = time.time()
def write(self, out):
"""Abstract method"""
raise NotImplementedError
def is_expired(self, now):
return self.created + self.ttl <= now
def is_removable(self, now):
return self.created + self.ttl * 2 <= now
class DNSAddress(DNSRecord):
"""A DNS address record"""
def __init__(self, name, type_, class_, ttl, address):
DNSRecord.__init__(self, name, type_, class_, ttl)
self.address = address
def write(self, out):
"""Used in constructing an outgoing packet"""
out.write_string(self.address)
class DNSText(DNSRecord):
"""A DNS text record"""
def __init__(self, name, type_, class_, ttl, text):
assert isinstance(text, (bytes, type(None)))
DNSRecord.__init__(self, name, type_, class_, ttl)
self.text = text
def write(self, out):
"""Used in constructing an outgoing packet"""
out.write_string(self.text)
class DNSIncoming(QuietLogger):
"""Object representation of an incoming DNS packet"""
def __init__(self, data):
"""Constructor from string holding bytes of packet"""
self.offset = 0
self.data = data
self.questions = []
self.answers = []
self.id = 0
self.flags = 0 # type: int
self.num_questions = 0
self.num_answers = 0
self.num_authorities = 0
self.num_additionals = 0
self.valid = False
try:
self.read_header()
self.read_questions()
self.read_others()
self.valid = True
except (IndexError, struct.error, IncomingDecodeError):
self.log_exception_warning(
("Choked at offset %d while unpacking %r", self.offset, data)
)
def unpack(self, format_):
length = struct.calcsize(format_)
info = struct.unpack(format_, self.data[self.offset : self.offset + length])
self.offset += length
return info
def read_header(self):
"""Reads header portion of packet"""
(
self.id,
self.flags,
self.num_questions,
self.num_answers,
self.num_authorities,
self.num_additionals,
) = self.unpack(b"!6H")
def read_questions(self):
"""Reads questions section of packet"""
for _ in range(self.num_questions):
name = self.read_name()
type_, class_ = self.unpack(b"!HH")
question = DNSQuestion(name, type_, class_)
self.questions.append(question)
def read_character_string(self):
"""Reads a character string from the packet"""
length = self.data[self.offset]
self.offset += 1
return self.read_string(length)
def read_string(self, length):
"""Reads a string of a given length from the packet"""
info = self.data[self.offset : self.offset + length]
self.offset += length
return info
def read_unsigned_short(self):
"""Reads an unsigned short from the packet"""
return self.unpack(b"!H")[0]
def read_others(self):
"""Reads the answers, authorities and additionals section of the
packet"""
n = self.num_answers + self.num_authorities + self.num_additionals
for _ in range(n):
domain = self.read_name()
type_, class_, ttl, length = self.unpack(b"!HHiH")
rec = None
if type_ == _TYPE_A:
rec = DNSAddress(domain, type_, class_, ttl, self.read_string(4))
elif type_ == _TYPE_TXT:
rec = DNSText(domain, type_, class_, ttl, self.read_string(length))
elif type_ == _TYPE_AAAA:
rec = DNSAddress(domain, type_, class_, ttl, self.read_string(16))
else:
# Try to ignore types we don't know about
# Skip the payload for the resource record so the next
# records can be parsed correctly
self.offset += length
if rec is not None:
self.answers.append(rec)
def is_query(self):
"""Returns true if this is a query"""
return (self.flags & _FLAGS_QR_MASK) == _FLAGS_QR_QUERY
def is_response(self):
"""Returns true if this is a response"""
return (self.flags & _FLAGS_QR_MASK) == _FLAGS_QR_RESPONSE
def read_utf(self, offset, length):
"""Reads a UTF-8 string of a given length from the packet"""
return str(self.data[offset : offset + length], "utf-8", "replace")
def read_name(self):
"""Reads a domain name from the packet"""
result = ""
off = self.offset
next_ = -1
first = off
while True:
length = self.data[off]
off += 1
if length == 0:
break
t = length & 0xC0
if t == 0x00:
result = "".join((result, self.read_utf(off, length) + "."))
off += length
elif t == 0xC0:
if next_ < 0:
next_ = off + 1
off = ((length & 0x3F) << 8) | self.data[off]
if off >= first:
raise IncomingDecodeError(f"Bad domain name (circular) at {off}")
first = off
else:
raise IncomingDecodeError(f"Bad domain name at {off}")
if next_ >= 0:
self.offset = next_
else:
self.offset = off
return result
class DNSOutgoing:
"""Object representation of an outgoing packet"""
def __init__(self, flags):
self.finished = False
self.id = 0
self.flags = flags
self.names = {}
self.data = []
self.size = 12
self.state = False
self.questions = []
self.answers = []
def add_question(self, record):
"""Adds a question"""
self.questions.append(record)
def pack(self, format_, value):
self.data.append(struct.pack(format_, value))
self.size += struct.calcsize(format_)
def write_byte(self, value):
"""Writes a single byte to the packet"""
self.pack(b"!c", int2byte(value))
def insert_short(self, index, value):
"""Inserts an unsigned short in a certain position in the packet"""
self.data.insert(index, struct.pack(b"!H", value))
self.size += 2
def write_short(self, value):
"""Writes an unsigned short to the packet"""
self.pack(b"!H", value)
def write_int(self, value):
"""Writes an unsigned integer to the packet"""
self.pack(b"!I", int(value))
def write_string(self, value):
"""Writes a string to the packet"""
assert isinstance(value, bytes)
self.data.append(value)
self.size += len(value)
def write_utf(self, s):
"""Writes a UTF-8 string of a given length to the packet"""
utfstr = s.encode("utf-8")
length = len(utfstr)
self.write_byte(length)
self.write_string(utfstr)
def write_character_string(self, value):
assert isinstance(value, bytes)
length = len(value)
self.write_byte(length)
self.write_string(value)
def write_name(self, name):
# split name into each label
parts = name.split(".")
if not parts[-1]:
parts.pop()
# construct each suffix
name_suffices = [".".join(parts[i:]) for i in range(len(parts))]
# look for an existing name or suffix
for count, sub_name in enumerate(name_suffices):
if sub_name in self.names:
break
else:
count = len(name_suffices)
# note the new names we are saving into the packet
name_length = len(name.encode("utf-8"))
for suffix in name_suffices[:count]:
self.names[suffix] = (
self.size + name_length - len(suffix.encode("utf-8")) - 1
)
# write the new names out.
for part in parts[:count]:
self.write_utf(part)
# if we wrote part of the name, create a pointer to the rest
if count != len(name_suffices):
# Found substring in packet, create pointer
index = self.names[name_suffices[count]]
self.write_byte((index >> 8) | 0xC0)
self.write_byte(index & 0xFF)
else:
# this is the end of a name
self.write_byte(0)
def write_question(self, question):
self.write_name(question.name)
self.write_short(question.type)
self.write_short(question.class_)
def packet(self):
if not self.state:
for question in self.questions:
self.write_question(question)
self.state = True
self.insert_short(0, 0) # num additionals
self.insert_short(0, 0) # num authorities
self.insert_short(0, 0) # num answers
self.insert_short(0, len(self.questions))
self.insert_short(0, self.flags) # _FLAGS_QR_QUERY
self.insert_short(0, 0)
return b"".join(self.data)
class Engine(threading.Thread):
def __init__(self, zc):
threading.Thread.__init__(self, name="zeroconf-Engine")
self.daemon = True
self.zc = zc
self.readers = {}
self.timeout = 5
self.condition = threading.Condition()
self.start()
def run(self):
while not self.zc.done:
# pylint: disable=len-as-condition
with self.condition:
rs = self.readers.keys()
if len(rs) == 0:
# No sockets to manage, but we wait for the timeout
# or addition of a socket
self.condition.wait(self.timeout)
if len(rs) != 0:
try:
rr, _, _ = select.select(rs, [], [], self.timeout)
if not self.zc.done:
for socket_ in rr:
reader = self.readers.get(socket_)
if reader:
reader.handle_read(socket_)
except OSError as e:
# If the socket was closed by another thread, during
# shutdown, ignore it and exit
if e.args[0] != socket.EBADF or not self.zc.done:
raise
def add_reader(self, reader, socket_):
with self.condition:
self.readers[socket_] = reader
self.condition.notify()
def del_reader(self, socket_):
with self.condition:
del self.readers[socket_]
self.condition.notify()
class Listener(QuietLogger):
def __init__(self, zc):
self.zc = zc
self.data = None
def handle_read(self, socket_):
try:
data, (addr, port) = socket_.recvfrom(_MAX_MSG_ABSOLUTE)
except Exception: # pylint: disable=broad-except
self.log_exception_warning()
return
log.debug("Received from %r:%r: %r ", addr, port, data)
self.data = data
msg = DNSIncoming(data)
if not msg.valid or msg.is_query():
pass
else:
self.zc.handle_response(msg)
class RecordUpdateListener:
def update_record(self, zc, now, record):
raise NotImplementedError()
class HostResolver(RecordUpdateListener):
def __init__(self, name):
def __init__(self, name: str):
self.name = name
self.address = None
self.address: Optional[bytes] = None
def update_record(self, zc, now, record):
def update_record(self, zc: Zeroconf, now: float, record: DNSRecord) -> None:
if record is None:
return
if record.type == _TYPE_A:
@ -522,14 +29,14 @@ class HostResolver(RecordUpdateListener):
if record.name == self.name:
self.address = record.address
def request(self, zc, timeout):
def request(self, zc: Zeroconf, timeout: float) -> bool:
now = time.time()
delay = 0.2
next_ = now + delay
last = now + timeout
try:
zc.add_listener(self)
zc.add_listener(self, None)
while self.address is None:
if last <= now:
# Timeout
@ -550,56 +57,52 @@ class HostResolver(RecordUpdateListener):
class DashboardStatus(RecordUpdateListener, threading.Thread):
def __init__(self, zc, on_update):
PING_AFTER = 15 * 1000 # Send new mDNS request after 15 seconds
OFFLINE_AFTER = PING_AFTER * 2 # Offline if no mDNS response after 30 seconds
def __init__(self, zc: Zeroconf, on_update) -> None:
threading.Thread.__init__(self)
self.zc = zc
self.query_hosts = set()
self.key_to_host = {}
self.cache = {}
self.query_hosts: set[str] = set()
self.key_to_host: dict[str, str] = {}
self.stop_event = threading.Event()
self.query_event = threading.Event()
self.on_update = on_update
def update_record(self, zc, now, record):
if record is None:
return
if record.type in (_TYPE_A, _TYPE_AAAA, _TYPE_TXT):
assert isinstance(record, DNSEntry)
if record.name in self.query_hosts:
self.cache.setdefault(record.name, []).insert(0, record)
self.purge_cache()
def update_record(self, zc: Zeroconf, now: float, record: DNSRecord) -> None:
pass
def purge_cache(self):
new_cache = {}
for host, records in self.cache.items():
if host not in self.query_hosts:
continue
new_records = [rec for rec in records if not rec.is_removable(time.time())]
if new_records:
new_cache[host] = new_records
self.cache = new_cache
self.on_update({key: self.host_status(key) for key in self.key_to_host})
def request_query(self, hosts):
def request_query(self, hosts: dict[str, str]) -> None:
self.query_hosts = set(hosts.values())
self.key_to_host = hosts
self.query_event.set()
def stop(self):
def stop(self) -> None:
self.stop_event.set()
self.query_event.set()
def host_status(self, key):
return self.key_to_host.get(key) in self.cache
def host_status(self, key: str) -> bool:
entries = self.zc.cache.entries_with_name(key)
if not entries:
return False
now = time.time() * 1000
def run(self):
self.zc.add_listener(self)
return any(
(entry.created + DashboardStatus.OFFLINE_AFTER) >= now for entry in entries
)
def run(self) -> None:
self.zc.add_listener(self, None)
while not self.stop_event.is_set():
self.purge_cache()
self.on_update(
{key: self.host_status(host) for key, host in self.key_to_host.items()}
)
now = time.time() * 1000
for host in self.query_hosts:
if all(
record.is_expired(time.time())
for record in self.cache.get(host, [])
entries = self.zc.cache.entries_with_name(host)
if not entries or all(
(entry.created + DashboardStatus.PING_AFTER) <= now
for entry in entries
):
out = DNSOutgoing(_FLAGS_QR_QUERY)
out.add_question(DNSQuestion(host, _TYPE_A, _CLASS_IN))
@ -609,186 +112,9 @@ class DashboardStatus(RecordUpdateListener, threading.Thread):
self.zc.remove_listener(self)
def get_all_addresses():
return list(
{
addr.ip
for iface in ifaddr.get_adapters()
for addr in iface.ips
if addr.is_IPv4
and addr.network_prefix != 32 # Host only netmask 255.255.255.255
}
)
def new_socket():
s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
# SO_REUSEADDR should be equivalent to SO_REUSEPORT for
# multicast UDP sockets (p 731, "TCP/IP Illustrated,
# Volume 2"), but some BSD-derived systems require
# SO_REUSEPORT to be specified explicitly. Also, not all
# versions of Python have SO_REUSEPORT available.
# Catch OSError and socket.error for kernel versions <3.9 because lacking
# SO_REUSEPORT support.
try:
reuseport = socket.SO_REUSEPORT
except AttributeError:
pass
else:
try:
s.setsockopt(socket.SOL_SOCKET, reuseport, 1)
except OSError as err:
# OSError on python 3, socket.error on python 2
if err.errno != errno.ENOPROTOOPT:
raise
# OpenBSD needs the ttl and loop values for the IP_MULTICAST_TTL and
# IP_MULTICAST_LOOP socket options as an unsigned char.
ttl = struct.pack(b"B", 255)
s.setsockopt(socket.IPPROTO_IP, socket.IP_MULTICAST_TTL, ttl)
loop = struct.pack(b"B", 1)
s.setsockopt(socket.IPPROTO_IP, socket.IP_MULTICAST_LOOP, loop)
s.bind(("", _MDNS_PORT))
return s
class Zeroconf(QuietLogger):
def __init__(self):
# hook for threads
self._GLOBAL_DONE = False
self._listen_socket = new_socket()
interfaces = get_all_addresses()
self._respond_sockets = []
for i in interfaces:
try:
_value = socket.inet_aton(_MDNS_ADDR) + socket.inet_aton(i)
self._listen_socket.setsockopt(
socket.IPPROTO_IP, socket.IP_ADD_MEMBERSHIP, _value
)
except OSError as e:
_errno = e.args[0]
if _errno == errno.EADDRINUSE:
log.info(
"Address in use when adding %s to multicast group, "
"it is expected to happen on some systems",
i,
)
elif _errno == errno.EADDRNOTAVAIL:
log.info(
"Address not available when adding %s to multicast "
"group, it is expected to happen on some systems",
i,
)
continue
elif _errno == errno.EINVAL:
log.info(
"Interface of %s does not support multicast, "
"it is expected in WSL",
i,
)
continue
else:
raise
respond_socket = new_socket()
respond_socket.setsockopt(
socket.IPPROTO_IP, socket.IP_MULTICAST_IF, socket.inet_aton(i)
)
self._respond_sockets.append(respond_socket)
self.listeners = []
self.condition = threading.Condition()
self.engine = Engine(self)
self.listener = Listener(self)
self.engine.add_reader(self.listener, self._listen_socket)
@property
def done(self):
return self._GLOBAL_DONE
def wait(self, timeout):
"""Calling thread waits for a given number of milliseconds or
until notified."""
with self.condition:
self.condition.wait(timeout)
def notify_all(self):
"""Notifies all waiting threads"""
with self.condition:
self.condition.notify_all()
def resolve_host(self, host, timeout=3.0):
class EsphomeZeroconf(Zeroconf):
def resolve_host(self, host: str, timeout=3.0):
info = HostResolver(host)
if info.request(self, timeout):
return socket.inet_ntoa(info.address)
return None
def add_listener(self, listener):
self.listeners.append(listener)
self.notify_all()
def remove_listener(self, listener):
"""Removes a listener."""
try:
self.listeners.remove(listener)
self.notify_all()
except Exception as e: # pylint: disable=broad-except
log.exception("Unknown error, possibly benign: %r", e)
def update_record(self, now, rec):
"""Used to notify listeners of new information that has updated
a record."""
for listener in self.listeners:
listener.update_record(self, now, rec)
self.notify_all()
def handle_response(self, msg):
"""Deal with incoming response packets. All answers
are held in the cache, and listeners are notified."""
now = time.time()
for record in msg.answers:
self.update_record(now, record)
def send(self, out):
"""Sends an outgoing packet."""
packet = out.packet()
log.debug("Sending %r (%d bytes) as %r...", out, len(packet), packet)
for s in self._respond_sockets:
if self._GLOBAL_DONE:
return
try:
bytes_sent = s.sendto(packet, 0, (_MDNS_ADDR, _MDNS_PORT))
except Exception: # pylint: disable=broad-except
# on send errors, log the exception and keep going
self.log_exception_warning()
else:
if bytes_sent != len(packet):
self.log_warning_once(
"!!! sent %d out of %d bytes to %r"
% (bytes_sent, len(packet), s)
)
def close(self):
"""Ends the background threads, and prevent this instance from
servicing further queries."""
if not self._GLOBAL_DONE:
self._GLOBAL_DONE = True
# shutdown recv socket and thread
self.engine.del_reader(self._listen_socket)
self._listen_socket.close()
self.engine.join()
# shutdown the rest
self.notify_all()
for s in self._respond_sockets:
s.close()