docker-offlineimap/offlineimap/imapserver.py
Rodolfo García Peñas (kix) 48f2df4267 Handle connection refused messages
This patch handle the connection refused messages. One of these messages
is related to returned zeros.
2021-08-07 20:33:06 +02:00

908 lines
38 KiB
Python

# IMAP server support
# Copyright (C) 2002-2018 John Goerzen & contributors.
#
# This program 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 2 of the License, or
# (at your option) any later version.
#
# This program 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 this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
import datetime
import hashlib
import hmac
import json
import urllib.request
import urllib.parse
import urllib.error
import time
import errno
import socket
from socket import gaierror
from sys import exc_info
from ssl import SSLError, cert_time_to_seconds
from threading import Lock, BoundedSemaphore, Thread, Event, currentThread
import offlineimap.accounts
from offlineimap import imaplibutil, imaputil, threadutil, OfflineImapError
from offlineimap.ui import getglobalui
try:
import gssapi
have_gss = True
except ImportError:
have_gss = False
class IMAPServer:
"""Initializes all variables from an IMAPRepository() instance
Various functions, such as acquireconnection() return an IMAP4
object on which we can operate.
Public instance variables are: self.:
delim The server's folder delimiter. Only valid after acquireconnection()
"""
def __init__(self, repos):
""":repos: a IMAPRepository instance."""
self.ui = getglobalui()
self.repos = repos
self.config = repos.getconfig()
self.preauth_tunnel = repos.getpreauthtunnel()
self.transport_tunnel = repos.gettransporttunnel()
if self.preauth_tunnel and self.transport_tunnel:
raise OfflineImapError('%s: ' % repos +
'you must enable precisely one '
'type of tunnel (preauth or transport), '
'not both', OfflineImapError.ERROR.REPO)
self.tunnel = \
self.preauth_tunnel if self.preauth_tunnel \
else self.transport_tunnel
self.username = \
None if self.preauth_tunnel else repos.getuser()
self.user_identity = repos.get_remote_identity()
self.authmechs = repos.get_auth_mechanisms()
self.password = None
self.passworderror = None
self.goodpassword = None
self.usessl = repos.getssl()
self.useipv6 = repos.getipv6()
if self.useipv6 is True:
self.af = socket.AF_INET6
elif self.useipv6 is False:
self.af = socket.AF_INET
else:
self.af = socket.AF_UNSPEC
self.hostname = None if self.transport_tunnel or self.preauth_tunnel else repos.gethost()
self.port = repos.getport()
if self.port is None:
self.port = 993 if self.usessl else 143
self.sslclientcert = repos.getsslclientcert()
self.sslclientkey = repos.getsslclientkey()
self.sslcacertfile = repos.getsslcacertfile()
if self.sslcacertfile is None:
self.__verifycert = None # Disable cert verification.
# This way of working sucks hard...
self.fingerprint = repos.get_ssl_fingerprint()
if self.fingerprint is not None:
self.__verifycert = None # if we have a cert fingerprint
# we do not require verfication via CA
self.tlslevel = repos.gettlslevel()
self.sslversion = repos.getsslversion()
self.starttls = repos.getstarttls()
if self.usessl \
and self.tlslevel != "tls_compat" \
and self.sslversion is None:
raise Exception("When 'tls_level' is not 'tls_compat' "
"the 'ssl_version' must be set explicitly.")
self.oauth2_refresh_token = repos.getoauth2_refresh_token()
self.oauth2_access_token = repos.getoauth2_access_token()
self.oauth2_client_id = repos.getoauth2_client_id()
self.oauth2_client_secret = repos.getoauth2_client_secret()
self.oauth2_request_url = repos.getoauth2_request_url()
self.oauth2_access_token_expires_at = None
self.delim = None
self.root = None
self.maxconnections = repos.getmaxconnections()
self.availableconnections = []
self.assignedconnections = []
self.lastowner = {}
self.semaphore = BoundedSemaphore(self.maxconnections)
self.connectionlock = Lock()
self.reference = repos.getreference()
self.idlefolders = repos.getidlefolders()
self.gss_vc = None
self.gssapi = False
# In order to support proxy connection, we have to override the
# default socket instance with our own socksified socket instance.
# We add this option to bypass the GFW in China.
self.proxied_socket = self._get_proxy('proxy', socket.socket)
# Turns out that the GFW in China is no longer blocking imap.gmail.com
# However accounts.google.com (for oauth2) definitey is. Therefore
# it is not strictly necessary to use a proxy for *both* IMAP *and*
# oauth2, so a new option is added: authproxy.
# Set proxy for use in authentication (only) if desired.
# If not set, is same as proxy option (compatible with current configs)
# To use a proxied_socket but not an authproxied_socket
# set authproxy = '' in config
self.authproxied_socket = self._get_proxy('authproxy',
self.proxied_socket)
def _get_proxy(self, proxysection, dfltsocket):
_account_section = 'Account ' + self.repos.account.name
if not self.config.has_option(_account_section, proxysection):
return dfltsocket
proxy = self.config.get(_account_section, proxysection)
if proxy == '':
# explicitly set no proxy (overrides default return of dfltsocket)
return socket.socket
# Powered by PySocks.
try:
import socks
proxy_type, host, port = proxy.split(":")
port = int(port)
socks.setdefaultproxy(getattr(socks, proxy_type), host, port)
return socks.socksocket
except ImportError:
self.ui.warn("PySocks not installed, ignoring proxy option.")
except (AttributeError, ValueError) as e:
self.ui.warn("Bad proxy option %s for account %s: %s "
"Ignoring %s option." %
(proxy, self.repos.account.name, e, proxysection))
return dfltsocket
def __getpassword(self):
"""Returns the server password or None"""
if self.goodpassword is not None: # use cached good one first
return self.goodpassword
if self.password is not None and self.passworderror is None:
return self.password # non-failed preconfigured one
# get 1) configured password first 2) fall back to asking via UI
self.password = self.repos.getpassword() or \
self.ui.getpass(self.username, self.config, self.passworderror)
self.passworderror = None
return self.password
def __md5handler(self, response):
challenge = response.strip()
self.ui.debug('imap', '__md5handler: got challenge %s' % challenge)
passwd = self.__getpassword()
retval = self.username + ' ' +\
hmac.new(bytes(passwd, encoding='utf-8'), challenge,
digestmod=hashlib.md5).hexdigest()
self.ui.debug('imap', '__md5handler: returning %s' % retval)
return retval
def __loginauth(self, imapobj):
""" Basic authentication via LOGIN command."""
self.ui.debug('imap', 'Attempting IMAP LOGIN authentication')
imapobj.login(self.username, self.__getpassword())
def __plainhandler(self, response):
"""Implements SASL PLAIN authentication, RFC 4616,
http://tools.ietf.org/html/rfc4616"""
authc = self.username
if not authc:
raise OfflineImapError("No username provided for '%s'"
% self.repos.getname(),
OfflineImapError.ERROR.REPO)
passwd = self.__getpassword()
authz = ''
NULL = '\x00'
if self.user_identity is not None:
authz = self.user_identity
retval = NULL.join((authz, authc, passwd))
self.ui.debug('imap', '__plainhandler: returning %s %s '
'(passwd hidden for log)' % (authz, authc))
return retval
def __xoauth2handler(self, response):
now = datetime.datetime.now()
if self.oauth2_access_token_expires_at \
and self.oauth2_access_token_expires_at < now:
self.oauth2_access_token = None
self.ui.debug('imap', 'xoauth2handler: oauth2_access_token expired')
if self.oauth2_access_token is None:
if self.oauth2_request_url is None:
raise OfflineImapError("No remote oauth2_request_url for "
"repository '%s' specified." %
self, OfflineImapError.ERROR.REPO)
# Generate new access token.
params = {}
params['client_id'] = self.oauth2_client_id
params['client_secret'] = self.oauth2_client_secret
params['refresh_token'] = self.oauth2_refresh_token
params['grant_type'] = 'refresh_token'
self.ui.debug('imap', 'xoauth2handler: url "%s"' %
self.oauth2_request_url)
self.ui.debug('imap', 'xoauth2handler: params "%s"' % params)
original_socket = socket.socket
socket.socket = self.authproxied_socket
try:
response = urllib.request.urlopen(
self.oauth2_request_url, urllib.parse.urlencode(params).encode('utf-8')).read()
except Exception as e:
try:
msg = "%s (configuration is: %s)" % (e, str(params))
except Exception as eparams:
msg = "%s [cannot display configuration: %s]" % (e, eparams)
self.ui.error(msg)
raise
finally:
socket.socket = original_socket
resp = json.loads(response)
self.ui.debug('imap', 'xoauth2handler: response "%s"' % resp)
if 'error' in resp:
raise OfflineImapError("xoauth2handler got: %s" % resp,
OfflineImapError.ERROR.REPO)
self.oauth2_access_token = resp['access_token']
if 'expires_in' in resp:
self.oauth2_access_token_expires_at = now + datetime.timedelta(
seconds=resp['expires_in'] / 2
)
self.ui.debug('imap', 'xoauth2handler: access_token "%s expires %s"' % (
self.oauth2_access_token, self.oauth2_access_token_expires_at))
auth_string = 'user=%s\1auth=Bearer %s\1\1' % (
self.username, self.oauth2_access_token)
# auth_string = base64.b64encode(auth_string)
self.ui.debug('imap', 'xoauth2handler: returning "%s"' % auth_string)
return auth_string
# Perform the next step handling a GSSAPI connection.
# Client sends first, so token will be ignored if there is no context.
def __gsshandler(self, token):
if token == "":
token = None
try:
if not self.gss_vc:
name = gssapi.Name('imap@' + self.hostname,
gssapi.NameType.hostbased_service)
self.gss_vc = gssapi.SecurityContext(usage="initiate",
name=name)
if not self.gss_vc.complete:
response = self.gss_vc.step(token)
return response if response else ""
elif token is None:
# uh... context is complete, so there's no negotiation we can
# do. But we also don't have a token, so we can't send any
# kind of response. Empirically, some (but not all) servers
# seem to put us in this state, and seem fine with getting no
# GSSAPI content in response, so give it to them.
return ""
# Don't bother checking qop because we're over a TLS channel
# already. But hey, if some server started encrypting tomorrow,
# we'd be ready since krb5 always requests integrity and
# confidentiality support.
response = self.gss_vc.unwrap(token)
# This is a behavior we got from pykerberos. First byte is one,
# first four bytes are preserved (pykerberos calls this a length).
# Any additional bytes are username.
reply = b'\x01' + response.message[1:4]
reply += bytes(self.username, 'utf-8')
response = self.gss_vc.wrap(reply, response.encrypted)
return response.message if response.message else ""
except gssapi.exceptions.GSSError as err:
# GSSAPI errored out on us; respond with None to cancel the
# authentication
self.ui.debug('imap', err.gen_message())
return None
def __start_tls(self, imapobj):
if 'STARTTLS' in imapobj.capabilities and not self.usessl:
self.ui.debug('imap', 'Using STARTTLS connection')
try:
imapobj.starttls()
except imapobj.error as e:
raise OfflineImapError("Failed to start "
"TLS connection: %s" % str(e),
OfflineImapError.ERROR.REPO,
exc_info()[2])
# All __authn_* procedures are helpers that do authentication.
# They are class methods that take one parameter, IMAP object.
#
# Each function should return True if authentication was
# successful and False if authentication wasn't even tried
# for some reason (but not when IMAP has no such authentication
# capability, calling code checks that).
#
# Functions can also raise exceptions; two types are special
# and will be handled by the calling code:
#
# - imapobj.error means that there was some error that
# comes from imaplib2;
#
# - OfflineImapError means that function detected some
# problem by itself.
def __authn_gssapi(self, imapobj):
if not have_gss:
return False
self.connectionlock.acquire()
try:
imapobj.authenticate('GSSAPI', self.__gsshandler)
return True
except imapobj.error:
self.gssapi = False
raise
finally:
self.connectionlock.release()
def __authn_cram_md5(self, imapobj):
imapobj.authenticate('CRAM-MD5', self.__md5handler)
return True
def __authn_plain(self, imapobj):
imapobj.authenticate('PLAIN', self.__plainhandler)
return True
def __authn_xoauth2(self, imapobj):
if self.oauth2_refresh_token is None \
and self.oauth2_access_token is None:
return False
imapobj.authenticate('XOAUTH2', self.__xoauth2handler)
return True
def __authn_login(self, imapobj):
# Use LOGIN command, unless LOGINDISABLED is advertized
# (per RFC 2595)
if 'LOGINDISABLED' in imapobj.capabilities:
raise OfflineImapError("IMAP LOGIN is "
"disabled by server. Need to use SSL?",
OfflineImapError.ERROR.REPO)
else:
self.__loginauth(imapobj)
return True
def __authn_helper(self, imapobj):
"""Authentication machinery for self.acquireconnection().
Raises OfflineImapError() of type ERROR.REPO when
there are either fatal problems or no authentications
succeeded.
If any authentication method succeeds, routine should exit:
warnings for failed methods are to be produced in the
respective except blocks."""
# Stack stores pairs of (method name, exception)
exc_stack = []
tried_to_authn = False
tried_tls = False
# Authentication routines, hash keyed by method name
# with value that is a tuple with
# - authentication function,
# - tryTLS flag,
# - check IMAP capability flag.
auth_methods = {
"GSSAPI": (self.__authn_gssapi, False, True),
"XOAUTH2": (self.__authn_xoauth2, True, True),
"CRAM-MD5": (self.__authn_cram_md5, True, True),
"PLAIN": (self.__authn_plain, True, True),
"LOGIN": (self.__authn_login, True, False),
}
# GSSAPI is tried first by default: we will probably go TLS after it and
# GSSAPI mustn't be tunneled over TLS.
for m in self.authmechs:
if m not in auth_methods:
raise Exception("Bad authentication method %s, "
"please, file OfflineIMAP bug" % m)
func, tryTLS, check_cap = auth_methods[m]
# TLS must be initiated before checking capabilities:
# they could have been changed after STARTTLS.
if tryTLS and self.starttls and not tried_tls:
tried_tls = True
self.__start_tls(imapobj)
if check_cap:
cap = "AUTH=" + m
if cap not in imapobj.capabilities:
continue
tried_to_authn = True
self.ui.debug('imap', 'Attempting '
'%s authentication' % m)
try:
if func(imapobj):
return
except (imapobj.error, OfflineImapError) as e:
self.ui.warn('%s authentication failed: %s' % (m, e))
exc_stack.append((m, e))
if len(exc_stack):
msg = "\n\t".join([": ".join((x[0], str(x[1]))) for x in exc_stack])
raise OfflineImapError("All authentication types "
"failed:\n\t%s" % msg, OfflineImapError.ERROR.REPO)
if not tried_to_authn:
methods = ", ".join([x[5:] for x in
[x for x in imapobj.capabilities if x[0:5] == "AUTH="]])
raise OfflineImapError("Repository %s: no supported "
"authentication mechanisms found; configured %s, "
"server advertises %s" % (self.repos,
", ".join(self.authmechs), methods),
OfflineImapError.ERROR.REPO)
def __verifycert(self, cert, hostname):
"""Verify that cert (in socket.getpeercert() format) matches hostname.
CRLs are not handled.
Returns error message if any problems are found and None on success."""
errstr = "CA Cert verifying failed: "
if not cert:
return '%s no certificate received' % errstr
dnsname = hostname.lower()
certnames = []
# cert expired?
notafter = cert.get('notAfter')
if notafter:
if time.time() >= cert_time_to_seconds(notafter):
return '%s certificate expired %s' % (errstr, notafter)
# First read commonName
for s in cert.get('subject', []):
key, value = s[0]
if key == 'commonName':
certnames.append(value.lower())
if len(certnames) == 0:
return '%s no commonName found in certificate' % errstr
# Then read subjectAltName
for key, value in cert.get('subjectAltName', []):
if key == 'DNS':
certnames.append(value.lower())
# And finally try to match hostname with one of these names
for certname in certnames:
if (certname == dnsname or
'.' in dnsname and certname == '*.' + dnsname.split('.', 1)[1]):
return None
return '%s no matching domain name found in certificate' % errstr
def acquireconnection(self):
"""Fetches a connection from the pool, making sure to create a new one
if needed, to obey the maximum connection limits, etc.
Opens a connection to the server and returns an appropriate
object."""
self.semaphore.acquire()
self.connectionlock.acquire()
curThread = currentThread()
imapobj = None
imap_debug = 0
if 'imap' in self.ui.debuglist:
imap_debug = 5
if len(self.availableconnections): # One is available.
# Try to find one that previously belonged to this thread
# as an optimization. Start from the back since that's where
# they're popped on.
for i in range(len(self.availableconnections) - 1, -1, -1):
tryobj = self.availableconnections[i]
if self.lastowner[tryobj] == curThread.ident:
imapobj = tryobj
del (self.availableconnections[i])
break
if not imapobj:
imapobj = self.availableconnections[0]
del (self.availableconnections[0])
self.assignedconnections.append(imapobj)
self.lastowner[imapobj] = curThread.ident
self.connectionlock.release()
return imapobj
self.connectionlock.release() # Release until need to modify data
# Must be careful here that if we fail we should bail out gracefully
# and release locks / threads so that the next attempt can try...
success = False
try:
while success is not True:
# Generate a new connection.
if self.tunnel:
self.ui.connecting(
self.repos.getname(), 'tunnel', self.tunnel)
imapobj = imaplibutil.IMAP4_Tunnel(
self.tunnel,
timeout=socket.getdefaulttimeout(),
debug=imap_debug,
use_socket=self.proxied_socket,
)
success = True
elif self.usessl:
self.ui.connecting(
self.repos.getname(), self.hostname, self.port)
self.ui.debug('imap', "%s: level '%s', version '%s'" %
(self.repos.getname(), self.tlslevel, self.sslversion))
imapobj = imaplibutil.WrappedIMAP4_SSL(
host=self.hostname,
port=self.port,
keyfile=self.sslclientkey,
certfile=self.sslclientcert,
ca_certs=self.sslcacertfile,
cert_verify_cb=self.__verifycert,
ssl_version=self.sslversion,
debug=imap_debug,
timeout=socket.getdefaulttimeout(),
fingerprint=self.fingerprint,
use_socket=self.proxied_socket,
tls_level=self.tlslevel,
af=self.af,
)
else:
self.ui.connecting(
self.repos.getname(), self.hostname, self.port)
imapobj = imaplibutil.WrappedIMAP4(
self.hostname, self.port,
timeout=socket.getdefaulttimeout(),
use_socket=self.proxied_socket,
debug=imap_debug,
af=self.af,
)
if not self.preauth_tunnel:
try:
self.__authn_helper(imapobj)
self.goodpassword = self.password
success = True
except OfflineImapError as e:
self.passworderror = str(e)
raise
# Enable compression
if self.repos.getconfboolean('usecompression', 0):
imapobj.enable_compression()
# update capabilities after login, e.g. gmail serves different ones
typ, dat = imapobj.capability()
if dat != [None]:
# Get the capabilities and convert them to string from bytes
s_dat = [x.decode('utf-8') for x in dat[-1].upper().split()]
imapobj.capabilities = tuple(s_dat)
if self.delim is None:
listres = imapobj.list(self.reference, '""')[1]
if listres == [None] or listres is None:
# Some buggy IMAP servers do not respond well to LIST "" ""
# Work around them.
listres = imapobj.list(self.reference, '"*"')[1]
if listres == [None] or listres is None:
# No Folders were returned. This occurs, e.g. if the
# 'reference' prefix does not exist on the mail
# server. Raise exception.
err = "Server '%s' returned no folders in '%s'" % \
(self.repos.getname(), self.reference)
self.ui.warn(err)
raise Exception(err)
self.delim, self.root = \
imaputil.imapsplit(listres[0])[1:]
self.delim = imaputil.dequote(self.delim)
self.root = imaputil.dequote(self.root)
with self.connectionlock:
self.assignedconnections.append(imapobj)
self.lastowner[imapobj] = curThread.ident
return imapobj
except Exception as e:
"""If we are here then we did not succeed in getting a
connection - we should clean up and then re-raise the
error..."""
self.semaphore.release()
severity = OfflineImapError.ERROR.REPO
if type(e) == gaierror:
# DNS related errors. Abort Repo sync
# TODO: special error msg for e.errno == 2 "Name or service not known"?
reason = "Could not resolve name '%s' for repository " \
"'%s'. Make sure you have configured the ser" \
"ver name correctly and that you are online." % \
(self.hostname, self.repos)
raise OfflineImapError(reason, severity, exc_info()[2])
elif isinstance(e, SSLError) and e.errno == errno.EPERM:
# SSL unknown protocol error
# happens e.g. when connecting via SSL to a non-SSL service
if self.port != 993:
reason = "Could not connect via SSL to host '%s' and non-s" \
"tandard ssl port %d configured. Make sure you connect" \
" to the correct port. Got: %s" % (
self.hostname, self.port, e)
else:
reason = "Unknown SSL protocol connecting to host '%s' for " \
"repository '%s'. OpenSSL responded:\n%s" \
% (self.hostname, self.repos, e)
raise OfflineImapError(reason, severity, exc_info()[2])
elif isinstance(e, socket.error) and e.args and e.args[0] == errno.ECONNREFUSED:
# "Connection refused", can be a non-existing port, or an unauthorized
# webproxy (open WLAN?)
reason = "Connection to host '%s:%d' for repository '%s' was " \
"refused. Make sure you have the right host and port " \
"configured and that you are actually able to access the " \
"network." % (self.hostname, self.port, self.repos)
raise OfflineImapError(reason, severity, exc_info()[2])
# Could not acquire connection to the remote;
# socket.error(last_error) raised
if str(e)[:24] == "can't open socket; error":
raise OfflineImapError(
"Could not connect to remote server '%s' "
"for repository '%s'. Remote does not answer." % (self.hostname, self.repos),
OfflineImapError.ERROR.REPO,
exc_info()[2])
elif e.args and \
e.args[0][:35] == 'IMAP4 protocol error: socket error:':
raise OfflineImapError(
"Could not connect to remote server '{}' "
"for repository '{}'. Connection Refused.".format(
self.hostname, self.repos),
OfflineImapError.ERROR.CRITICAL)
else:
# re-raise all other errors
raise
def connectionwait(self):
"""Waits until there is a connection available.
Note that between the time that a connection becomes available and the
time it is requested, another thread may have grabbed it. This function
is mainly present as a way to avoid spawning thousands of threads to
copy messages, then have them all wait for 3 available connections.
It's OK if we have maxconnections + 1 or 2 threads, which is what this
will help us do."""
self.semaphore.acquire() # Blocking until maxconnections has free slots.
self.semaphore.release()
def close(self):
# Make sure I own all the semaphores. Let the threads finish
# their stuff. This is a blocking method.
with self.connectionlock:
# first, wait till all connections had been released.
# TODO: won't work IMHO, as releaseconnection() also
# requires the connectionlock, leading to a potential
# deadlock! Audit & check!
threadutil.semaphorereset(self.semaphore, self.maxconnections)
for imapobj in self.assignedconnections + self.availableconnections:
imapobj.logout()
self.assignedconnections = []
self.availableconnections = []
self.lastowner = {}
# reset GSSAPI state
self.gss_vc = None
self.gssapi = False
def keepalive(self, timeout, event):
"""Sends a NOOP to each connection recorded.
It will wait a maximum of timeout seconds between doing this, and will
continue to do so until the Event object as passed is true. This method
is expected to be invoked in a separate thread, which should be join()'d
after the event is set."""
self.ui.debug('imap', 'keepalive thread started')
while not event.isSet():
self.connectionlock.acquire()
numconnections = len(self.assignedconnections) + \
len(self.availableconnections)
self.connectionlock.release()
threads = []
for i in range(numconnections):
self.ui.debug('imap', 'keepalive: processing connection %d of %d' %
(i, numconnections))
if len(self.idlefolders) > i:
# IDLE thread
idler = IdleThread(self, self.idlefolders[i])
else:
# NOOP thread
idler = IdleThread(self)
idler.start()
threads.append(idler)
self.ui.debug('imap', 'keepalive: waiting for timeout')
event.wait(timeout)
self.ui.debug('imap', 'keepalive: after wait')
for idler in threads:
# Make sure all the commands have completed.
idler.stop()
idler.join()
self.ui.debug('imap', 'keepalive: all threads joined')
self.ui.debug('imap', 'keepalive: event is set; exiting')
return
def releaseconnection(self, connection, drop_conn=False):
"""Releases a connection, returning it to the pool.
:param connection: Connection object
:param drop_conn: If True, the connection will be released and
not be reused. This can be used to indicate broken connections."""
if connection is None:
return # Noop on bad connection.
self.connectionlock.acquire()
self.assignedconnections.remove(connection)
# Don't reuse broken connections
if connection.Terminate or drop_conn:
connection.logout()
else:
self.availableconnections.append(connection)
self.connectionlock.release()
self.semaphore.release()
class IdleThread:
def __init__(self, parent, folder=None):
"""If invoked without 'folder', perform a NOOP and wait for
self.stop() to be called. If invoked with folder, switch to IDLE
mode and synchronize once we have a new message"""
self.parent = parent
self.folder = folder
self.stop_sig = Event()
self.ui = getglobalui()
if folder is None:
self.thread = Thread(target=self.noop)
else:
self.thread = Thread(target=self.__idle)
self.thread.setDaemon(True)
def start(self):
self.thread.start()
def stop(self):
self.stop_sig.set()
def join(self):
self.thread.join()
def noop(self):
# TODO: AFAIK this is not optimal, we will send a NOOP on one
# random connection (ie not enough to keep all connections
# open). In case we do the noop multiple times, we can well use
# the same connection every time, as we get a random one. This
# function should IMHO send a noop on ALL available connections
# to the server.
imapobj = self.parent.acquireconnection()
try:
imapobj.noop()
except imapobj.abort:
self.ui.warn('Attempting NOOP on dropped connection %s' %
imapobj.identifier)
self.parent.releaseconnection(imapobj, True)
imapobj = None
finally:
if imapobj:
self.parent.releaseconnection(imapobj)
self.stop_sig.wait() # wait until we are supposed to quit
def __dosync(self):
remoterepos = self.parent.repos
account = remoterepos.account
remoterepos = account.remoterepos
remotefolder = remoterepos.getfolder(self.folder, decode=False)
hook = account.getconf('presynchook', '')
account.callhook(hook)
offlineimap.accounts.syncfolder(account, remotefolder, quick=False)
hook = account.getconf('postsynchook', '')
account.callhook(hook)
ui = getglobalui()
ui.unregisterthread(currentThread()) # syncfolder registered the thread
def __idle(self):
"""Invoke IDLE mode until timeout or self.stop() is invoked."""
def callback(args):
"""IDLE callback function invoked by imaplib2.
This is invoked when a) The IMAP server tells us something
while in IDLE mode, b) we get an Exception (e.g. on dropped
connections, or c) the standard imaplib IDLE timeout of 29
minutes kicks in."""
result, cb_arg, exc_data = args
if exc_data is None and not self.stop_sig.isSet():
# No Exception, and we are not supposed to stop:
self.needsync = True
self.stop_sig.set() # Continue to sync.
def noop(imapobj):
"""Factorize the noop code."""
try:
# End IDLE mode with noop, imapobj can point to a dropped conn.
imapobj.noop()
except imapobj.abort:
self.ui.warn('Attempting NOOP on dropped connection %s' %
imapobj.identifier)
self.parent.releaseconnection(imapobj, True)
else:
self.parent.releaseconnection(imapobj)
while not self.stop_sig.isSet():
self.needsync = False
success = False # Successfully selected FOLDER?
while not success:
imapobj = self.parent.acquireconnection()
try:
imapobj.select(self.folder)
except OfflineImapError as e:
if e.severity == OfflineImapError.ERROR.FOLDER_RETRY:
# Connection closed, release connection and retry.
self.ui.error(e, exc_info()[2])
self.parent.releaseconnection(imapobj, True)
elif e.severity == OfflineImapError.ERROR.FOLDER:
# Just continue the process on such error for now.
self.ui.error(e, exc_info()[2])
else:
# Stops future attempts to sync this account.
raise
else:
success = True
if "IDLE" in imapobj.capabilities:
imapobj.idle(callback=callback)
else:
self.ui.warn("IMAP IDLE not supported on server '%s'."
"Sleep until next refresh cycle." % imapobj.identifier)
noop(imapobj) # XXX: why?
self.stop_sig.wait() # self.stop() or IDLE callback are invoked.
noop(imapobj)
if self.needsync:
# Here not via self.stop, but because IDLE responded. Do
# another round and invoke actual syncing.
self.stop_sig.clear()
self.__dosync()