tnetwork dns hacks: split from network.py into its own file - electrum - Electrum Bitcoin wallet
HTML git clone https://git.parazyd.org/electrum
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DIR Files
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DIR Submodules
---
DIR commit 11452722aff3877b7033c2e873f73e906a110a78
DIR parent cb88a3b6e45e1261d4926d6d385f8f779a84a2d9
HTML Author: SomberNight <somber.night@protonmail.com>
Date: Wed, 1 Jan 2020 07:21:08 +0100
network dns hacks: split from network.py into its own file
Diffstat:
A electrum/dns_hacks.py | 100 +++++++++++++++++++++++++++++++
M electrum/network.py | 77 ++-----------------------------
2 files changed, 103 insertions(+), 74 deletions(-)
---
DIR diff --git a/electrum/dns_hacks.py b/electrum/dns_hacks.py
t@@ -0,0 +1,100 @@
+# Copyright (C) 2020 The Electrum developers
+# Distributed under the MIT software license, see the accompanying
+# file LICENCE or http://www.opensource.org/licenses/mit-license.php
+
+import sys
+import socket
+import concurrent
+from concurrent import futures
+import ipaddress
+from typing import Optional
+
+import dns
+import dns.resolver
+
+from .logging import get_logger
+
+
+_logger = get_logger(__name__)
+
+_dns_threads_executor = None # type: Optional[concurrent.futures.Executor]
+
+
+def configure_dns_depending_on_proxy(is_proxy: bool) -> None:
+ # Store this somewhere so we can un-monkey-patch:
+ if not hasattr(socket, "_getaddrinfo"):
+ socket._getaddrinfo = socket.getaddrinfo
+ if is_proxy:
+ # prevent dns leaks, see http://stackoverflow.com/questions/13184205/dns-over-proxy
+ socket.getaddrinfo = lambda *args: [(socket.AF_INET, socket.SOCK_STREAM, 6, '', (args[0], args[1]))]
+ else:
+ if sys.platform == 'win32':
+ # On Windows, socket.getaddrinfo takes a mutex, and might hold it for up to 10 seconds
+ # when dns-resolving. To speed it up drastically, we resolve dns ourselves, outside that lock.
+ # See https://github.com/spesmilo/electrum/issues/4421
+ _prepare_windows_dns_hack()
+ socket.getaddrinfo = _fast_getaddrinfo
+ else:
+ socket.getaddrinfo = socket._getaddrinfo
+
+
+def _prepare_windows_dns_hack():
+ # enable dns cache
+ resolver = dns.resolver.get_default_resolver()
+ if resolver.cache is None:
+ resolver.cache = dns.resolver.Cache()
+ # prepare threads
+ global _dns_threads_executor
+ if _dns_threads_executor is None:
+ _dns_threads_executor = concurrent.futures.ThreadPoolExecutor(max_workers=20,
+ thread_name_prefix='dns_resolver')
+
+
+def _fast_getaddrinfo(host, *args, **kwargs):
+ def needs_dns_resolving(host):
+ try:
+ ipaddress.ip_address(host)
+ return False # already valid IP
+ except ValueError:
+ pass # not an IP
+ if str(host) in ('localhost', 'localhost.',):
+ return False
+ return True
+
+ def resolve_with_dnspython(host):
+ addrs = []
+ expected_errors = (dns.resolver.NXDOMAIN, dns.resolver.NoAnswer,
+ concurrent.futures.CancelledError, concurrent.futures.TimeoutError)
+ ipv6_fut = _dns_threads_executor.submit(dns.resolver.query, host, dns.rdatatype.AAAA)
+ ipv4_fut = _dns_threads_executor.submit(dns.resolver.query, host, dns.rdatatype.A)
+ # try IPv6
+ try:
+ answers = ipv6_fut.result()
+ addrs += [str(answer) for answer in answers]
+ except expected_errors as e:
+ pass
+ except BaseException as e:
+ _logger.info(f'dnspython failed to resolve dns (AAAA) for {repr(host)} with error: {repr(e)}')
+ # try IPv4
+ try:
+ answers = ipv4_fut.result()
+ addrs += [str(answer) for answer in answers]
+ except expected_errors as e:
+ # dns failed for some reason, e.g. dns.resolver.NXDOMAIN this is normal.
+ # Simply report back failure; except if we already have some results.
+ if not addrs:
+ raise socket.gaierror(11001, 'getaddrinfo failed') from e
+ except BaseException as e:
+ # Possibly internal error in dnspython :( see #4483 and #5638
+ _logger.info(f'dnspython failed to resolve dns (A) for {repr(host)} with error: {repr(e)}')
+ if addrs:
+ return addrs
+ # Fall back to original socket.getaddrinfo to resolve dns.
+ return [host]
+
+ addrs = [host]
+ if needs_dns_resolving(host):
+ addrs = resolve_with_dnspython(host)
+ list_of_list_of_socketinfos = [socket._getaddrinfo(addr, *args, **kwargs) for addr in addrs]
+ list_of_socketinfos = [item for lst in list_of_list_of_socketinfos for item in lst]
+ return list_of_socketinfos
DIR diff --git a/electrum/network.py b/electrum/network.py
t@@ -31,15 +31,12 @@ import threading
import socket
import json
import sys
-import ipaddress
import asyncio
from typing import NamedTuple, Optional, Sequence, List, Dict, Tuple, TYPE_CHECKING, Iterable
import traceback
import concurrent
from concurrent import futures
-import dns
-import dns.resolver
import aiorpcx
from aiorpcx import TaskGroup
from aiohttp import ClientResponse
t@@ -53,6 +50,7 @@ from .bitcoin import COIN
from . import constants
from . import blockchain
from . import bitcoin
+from . import dns_hacks
from .transaction import Transaction
from .blockchain import Blockchain, HEADER_SIZE
from .interface import (Interface, serialize_server, deserialize_server,
t@@ -228,8 +226,6 @@ class UntrustedServerReturnedError(NetworkException):
return f"<UntrustedServerReturnedError original_exception: {repr(self.original_exception)}>"
-_dns_threads_executor = None # type: Optional[concurrent.futures.Executor]
-
_INSTANCE = None
t@@ -557,77 +553,10 @@ class Network(Logger):
def _set_proxy(self, proxy: Optional[dict]):
self.proxy = proxy
- # Store these somewhere so we can un-monkey-patch
- if not hasattr(socket, "_getaddrinfo"):
- socket._getaddrinfo = socket.getaddrinfo
- if proxy:
- self.logger.info(f'setting proxy {proxy}')
- # prevent dns leaks, see http://stackoverflow.com/questions/13184205/dns-over-proxy
- socket.getaddrinfo = lambda *args: [(socket.AF_INET, socket.SOCK_STREAM, 6, '', (args[0], args[1]))]
- else:
- if sys.platform == 'win32':
- # On Windows, socket.getaddrinfo takes a mutex, and might hold it for up to 10 seconds
- # when dns-resolving. To speed it up drastically, we resolve dns ourselves, outside that lock.
- # see #4421
- resolver = dns.resolver.get_default_resolver()
- if resolver.cache is None:
- resolver.cache = dns.resolver.Cache()
- global _dns_threads_executor
- if _dns_threads_executor is None:
- _dns_threads_executor = concurrent.futures.ThreadPoolExecutor(max_workers=20)
- socket.getaddrinfo = self._fast_getaddrinfo
- else:
- socket.getaddrinfo = socket._getaddrinfo
+ dns_hacks.configure_dns_depending_on_proxy(bool(proxy))
+ self.logger.info(f'setting proxy {proxy}')
self.trigger_callback('proxy_set', self.proxy)
- @staticmethod
- def _fast_getaddrinfo(host, *args, **kwargs):
- def needs_dns_resolving(host):
- try:
- ipaddress.ip_address(host)
- return False # already valid IP
- except ValueError:
- pass # not an IP
- if str(host) in ('localhost', 'localhost.',):
- return False
- return True
- def resolve_with_dnspython(host):
- addrs = []
- expected_errors = (dns.resolver.NXDOMAIN, dns.resolver.NoAnswer,
- concurrent.futures.CancelledError, concurrent.futures.TimeoutError)
- ipv6_fut = _dns_threads_executor.submit(dns.resolver.query, host, dns.rdatatype.AAAA)
- ipv4_fut = _dns_threads_executor.submit(dns.resolver.query, host, dns.rdatatype.A)
- # try IPv6
- try:
- answers = ipv6_fut.result()
- addrs += [str(answer) for answer in answers]
- except expected_errors as e:
- pass
- except BaseException as e:
- _logger.info(f'dnspython failed to resolve dns (AAAA) for {repr(host)} with error: {repr(e)}')
- # try IPv4
- try:
- answers = ipv4_fut.result()
- addrs += [str(answer) for answer in answers]
- except expected_errors as e:
- # dns failed for some reason, e.g. dns.resolver.NXDOMAIN this is normal.
- # Simply report back failure; except if we already have some results.
- if not addrs:
- raise socket.gaierror(11001, 'getaddrinfo failed') from e
- except BaseException as e:
- # Possibly internal error in dnspython :( see #4483 and #5638
- _logger.info(f'dnspython failed to resolve dns (A) for {repr(host)} with error: {repr(e)}')
- if addrs:
- return addrs
- # Fall back to original socket.getaddrinfo to resolve dns.
- return [host]
- addrs = [host]
- if needs_dns_resolving(host):
- addrs = resolve_with_dnspython(host)
- list_of_list_of_socketinfos = [socket._getaddrinfo(addr, *args, **kwargs) for addr in addrs]
- list_of_socketinfos = [item for lst in list_of_list_of_socketinfos for item in lst]
- return list_of_socketinfos
-
@log_exceptions
async def set_parameters(self, net_params: NetworkParameters):
proxy = net_params.proxy