qutebrowser/qutebrowser/browser/adblock.py
Daniel Schadt a088f238e5 usertypes: remove Frankenstein's enum
This approach is not as weird in Python and still works.

DownloadTarget.OpenDownload has been renamed to OpenFileDownloadTarget,
since OpenDownloadDownloadTarget didn't look as nice.
2016-07-12 17:10:36 +02:00

305 lines
10 KiB
Python

# vim: ft=python fileencoding=utf-8 sts=4 sw=4 et:
# Copyright 2014-2016 Florian Bruhin (The Compiler) <mail@qutebrowser.org>
#
# This file is part of qutebrowser.
#
# qutebrowser is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# qutebrowser is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with qutebrowser. If not, see <http://www.gnu.org/licenses/>.
"""Functions related to ad blocking."""
import io
import os.path
import functools
import posixpath
import zipfile
import fnmatch
from qutebrowser.config import config
from qutebrowser.utils import objreg, standarddir, log, message, usertypes
from qutebrowser.commands import cmdutils, cmdexc
def guess_zip_filename(zf):
"""Guess which file to use inside a zip file.
Args:
zf: A ZipFile instance.
"""
files = zf.namelist()
if len(files) == 1:
return files[0]
else:
for e in files:
if posixpath.splitext(e)[0].lower() == 'hosts':
return e
raise FileNotFoundError("No hosts file found in zip")
def get_fileobj(byte_io):
"""Get a usable file object to read the hosts file from."""
byte_io.seek(0) # rewind downloaded file
if zipfile.is_zipfile(byte_io):
byte_io.seek(0) # rewind what zipfile.is_zipfile did
zf = zipfile.ZipFile(byte_io)
filename = guess_zip_filename(zf)
byte_io = zf.open(filename, mode='r')
else:
byte_io.seek(0) # rewind what zipfile.is_zipfile did
return io.TextIOWrapper(byte_io, encoding='utf-8')
def is_whitelisted_host(host):
"""Check if the given host is on the adblock whitelist.
Args:
host: The host of the request as string.
"""
whitelist = config.get('content', 'host-blocking-whitelist')
if whitelist is None:
return False
for pattern in whitelist:
if fnmatch.fnmatch(host, pattern.lower()):
return True
return False
class FakeDownload:
"""A download stub to use on_download_finished with local files."""
def __init__(self, fileobj):
self.basename = os.path.basename(fileobj.name)
self.fileobj = fileobj
self.successful = True
class HostBlocker:
"""Manage blocked hosts based from /etc/hosts-like files.
Attributes:
_blocked_hosts: A set of blocked hosts.
_config_blocked_hosts: A set of blocked hosts from ~/.config.
_in_progress: The DownloadItems which are currently downloading.
_done_count: How many files have been read successfully.
_local_hosts_file: The path to the blocked-hosts file.
_config_hosts_file: The path to a blocked-hosts in ~/.config
Class attributes:
WHITELISTED: Hosts which never should be blocked.
"""
WHITELISTED = ('localhost', 'localhost.localdomain', 'broadcasthost',
'local')
def __init__(self):
self._blocked_hosts = set()
self._config_blocked_hosts = set()
self._in_progress = []
self._done_count = 0
data_dir = standarddir.data()
if data_dir is None:
self._local_hosts_file = None
else:
self._local_hosts_file = os.path.join(data_dir, 'blocked-hosts')
self.on_config_changed()
config_dir = standarddir.config()
if config_dir is None:
self._config_hosts_file = None
else:
self._config_hosts_file = os.path.join(config_dir, 'blocked-hosts')
objreg.get('config').changed.connect(self.on_config_changed)
def is_blocked(self, url):
"""Check if the given URL (as QUrl) is blocked."""
if not config.get('content', 'host-blocking-enabled'):
return False
host = url.host()
return ((host in self._blocked_hosts or
host in self._config_blocked_hosts) and
not is_whitelisted_host(host))
def _read_hosts_file(self, filename, target):
"""Read hosts from the given filename.
Args:
filename: The file to read.
target: The set to store the hosts in.
Return:
True if a read was attempted, False otherwise
"""
if filename is None or not os.path.exists(filename):
return False
try:
with open(filename, 'r', encoding='utf-8') as f:
for line in f:
target.add(line.strip())
except OSError:
log.misc.exception("Failed to read host blocklist!")
return True
def read_hosts(self):
"""Read hosts from the existing blocked-hosts file."""
self._blocked_hosts = set()
if self._local_hosts_file is None:
return
self._read_hosts_file(self._config_hosts_file,
self._config_blocked_hosts)
found = self._read_hosts_file(self._local_hosts_file,
self._blocked_hosts)
if not found:
args = objreg.get('args')
if (config.get('content', 'host-block-lists') is not None and
args.basedir is None):
message.info('current',
"Run :adblock-update to get adblock lists.")
@cmdutils.register(instance='host-blocker')
@cmdutils.argument('win_id', win_id=True)
def adblock_update(self, win_id):
"""Update the adblock block lists.
This updates ~/.local/share/qutebrowser/blocked-hosts with downloaded
host lists and re-reads ~/.config/qutebrowser/blocked-hosts.
"""
self._read_hosts_file(self._config_hosts_file,
self._config_blocked_hosts)
if self._local_hosts_file is None:
raise cmdexc.CommandError("No data storage is configured!")
self._blocked_hosts = set()
self._done_count = 0
urls = config.get('content', 'host-block-lists')
download_manager = objreg.get('download-manager', scope='window',
window='last-focused')
if urls is None:
return
for url in urls:
if url.scheme() == 'file':
try:
fileobj = open(url.path(), 'rb')
except OSError as e:
message.error(win_id, "adblock: Error while reading {}: "
"{}".format(url.path(), e.strerror))
continue
download = FakeDownload(fileobj)
self._in_progress.append(download)
self.on_download_finished(download)
else:
fobj = io.BytesIO()
fobj.name = 'adblock: ' + url.host()
target = usertypes.FileObjDownloadTarget(fobj)
download = download_manager.get(url, target=target,
auto_remove=True)
self._in_progress.append(download)
download.finished.connect(
functools.partial(self.on_download_finished, download))
def _merge_file(self, byte_io):
"""Read and merge host files.
Args:
byte_io: The BytesIO object of the completed download.
Return:
A set of the merged hosts.
"""
error_count = 0
line_count = 0
try:
f = get_fileobj(byte_io)
except (OSError, UnicodeDecodeError, zipfile.BadZipFile,
zipfile.LargeZipFile) as e:
message.error('current', "adblock: Error while reading {}: {} - "
"{}".format(byte_io.name, e.__class__.__name__, e))
return
for line in f:
line_count += 1
# Remove comments
try:
hash_idx = line.index('#')
line = line[:hash_idx]
except ValueError:
pass
line = line.strip()
# Skip empty lines
if not line:
continue
parts = line.split()
if len(parts) == 1:
# "one host per line" format
host = parts[0]
elif len(parts) == 2:
# /etc/hosts format
host = parts[1]
else:
error_count += 1
continue
if host not in self.WHITELISTED:
self._blocked_hosts.add(host)
log.misc.debug("{}: read {} lines".format(byte_io.name, line_count))
if error_count > 0:
message.error('current', "adblock: {} read errors for {}".format(
error_count, byte_io.name))
def on_lists_downloaded(self):
"""Install block lists after files have been downloaded."""
with open(self._local_hosts_file, 'w', encoding='utf-8') as f:
for host in sorted(self._blocked_hosts):
f.write(host + '\n')
message.info('current', "adblock: Read {} hosts from {} sources."
.format(len(self._blocked_hosts), self._done_count))
@config.change_filter('content', 'host-block-lists')
def on_config_changed(self):
"""Update files when the config changed."""
urls = config.get('content', 'host-block-lists')
if urls is None and self._local_hosts_file is not None:
try:
os.remove(self._local_hosts_file)
except FileNotFoundError:
pass
except OSError as e:
log.misc.exception("Failed to delete hosts file: {}".format(e))
def on_download_finished(self, download):
"""Check if all downloads are finished and if so, trigger reading.
Arguments:
download: The finished DownloadItem.
"""
self._in_progress.remove(download)
if download.successful:
self._done_count += 1
try:
self._merge_file(download.fileobj)
finally:
download.fileobj.close()
if not self._in_progress:
try:
self.on_lists_downloaded()
except OSError:
log.misc.exception("Failed to write host block list!")