# IMAP server support # Copyright (C) 2002, 2003 John Goerzen # # # 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 from offlineimap import imaplib, imaputil, threadutil from offlineimap.ui import UIBase from threading import * import thread, hmac, os class UsefulIMAPMixIn: def getstate(self): return self.state def getselectedfolder(self): if self.getstate() == 'SELECTED': return self.selectedfolder return None def select(self, mailbox='INBOX', readonly=None, force = 0): if (not force) and self.getselectedfolder() == mailbox: self.is_readonly = readonly # No change; return. return result = self.__class__.__bases__[1].select(self, mailbox, readonly) if result[0] != 'OK': raise ValueError, "Error from select: %s" % str(result) if self.getstate() == 'SELECTED': self.selectedfolder = mailbox else: self.selectedfolder = None class UsefulIMAP4(UsefulIMAPMixIn, imaplib.IMAP4): pass class UsefulIMAP4_SSL(UsefulIMAPMixIn, imaplib.IMAP4_SSL): pass class UsefulIMAP4_Tunnel(UsefulIMAPMixIn, imaplib.IMAP4_Tunnel): pass class IMAPServer: def __init__(self, config, reposname, username = None, password = None, hostname = None, port = None, ssl = 1, maxconnections = 1, tunnel = None, reference = '""'): self.reposname = reposname self.config = config self.username = username self.password = password self.passworderror = None self.hostname = hostname self.tunnel = tunnel self.port = port self.usessl = ssl self.delim = None self.root = None if port == None: if ssl: self.port = 993 else: self.port = 143 self.maxconnections = maxconnections self.availableconnections = [] self.assignedconnections = [] self.lastowner = {} self.semaphore = BoundedSemaphore(self.maxconnections) self.connectionlock = Lock() self.reference = reference def getpassword(self): if self.password != None and self.passworderror == None: return self.password self.password = UIBase.getglobalui().getpass(self.reposname, self.config, self.passworderror) self.passworderror = None return self.password def getdelim(self): """Returns this server's folder delimiter. Can only be called after one or more calls to acquireconnection.""" return self.delim def getroot(self): """Returns this server's folder root. Can only be called after one or more calls to acquireconnection.""" return self.root def releaseconnection(self, connection): self.connectionlock.acquire() self.assignedconnections.remove(connection) self.availableconnections.append(connection) self.connectionlock.release() self.semaphore.release() def md5handler(self, response): ui = UIBase.getglobalui() challenge = response.strip() ui.debug('imap', 'md5handler: got challenge %s' % challenge) passwd = self.getpassword() retval = self.username + ' ' + hmac.new(passwd, challenge).hexdigest() ui.debug('imap', 'md5handler: returning %s' % retval) return retval def plainauth(self, imapobj): UIBase.getglobalui().debug('imap', 'Attempting plain authentication') imapobj.login(self.username, self.getpassword()) 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() imapobj = None 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. threadid = thread.get_ident() imapobj = None for i in range(len(self.availableconnections) - 1, -1, -1): tryobj = self.availableconnections[i] if self.lastowner[tryobj] == threadid: 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] = thread.get_ident() self.connectionlock.release() return imapobj self.connectionlock.release() # Release until need to modify data success = 0 while not success: # Generate a new connection. if self.tunnel: UIBase.getglobalui().connecting('tunnel', self.tunnel) imapobj = UsefulIMAP4_Tunnel(self.tunnel) success = 1 elif self.usessl: UIBase.getglobalui().connecting(self.hostname, self.port) imapobj = UsefulIMAP4_SSL(self.hostname, self.port) else: UIBase.getglobalui().connecting(self.hostname, self.port) imapobj = UsefulIMAP4(self.hostname, self.port) if not self.tunnel: try: if 'AUTH=CRAM-MD5' in imapobj.capabilities: UIBase.getglobalui().debug('imap', 'Attempting CRAM-MD5 authentication') try: imapobj.authenticate('CRAM-MD5', self.md5handler) except imapobj.error, val: self.plainauth(imapobj) else: self.plainauth(imapobj) # Would bail by here if there was a failure. success = 1 except imapobj.error, val: self.passworderror = str(val) self.password = None if self.delim == None: listres = imapobj.list(self.reference, '""')[1] if listres == [None] or listres == None: # Some buggy IMAP servers do not respond well to LIST "" "" # Work around them. listres = imapobj.list(self.reference, '"*"')[1] self.delim, self.root = \ imaputil.imapsplit(listres[0])[1:] self.delim = imaputil.dequote(self.delim) self.root = imaputil.dequote(self.root) self.connectionlock.acquire() self.assignedconnections.append(imapobj) self.lastowner[imapobj] = thread.get_ident() self.connectionlock.release() return imapobj 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.""" threadutil.semaphorewait(self.semaphore) def close(self): # Make sure I own all the semaphores. Let the threads finish # their stuff. This is a blocking method. self.connectionlock.acquire() threadutil.semaphorereset(self.semaphore, self.maxconnections) for imapobj in self.assignedconnections + self.availableconnections: imapobj.logout() self.assignedconnections = [] self.availableconnections = [] self.lastowner = {} self.connectionlock.release() 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.""" ui = UIBase.getglobalui() ui.debug('imap', 'keepalive thread started') while 1: ui.debug('imap', 'keepalive: top of loop') event.wait(timeout) ui.debug('imap', 'keepalive: after wait') if event.isSet(): ui.debug('imap', 'keepalive: event is set; exiting') return ui.debug('imap', 'keepalive: acquiring connectionlock') self.connectionlock.acquire() numconnections = len(self.assignedconnections) + \ len(self.availableconnections) self.connectionlock.release() ui.debug('imap', 'keepalive: connectionlock released') threads = [] imapobjs = [] for i in range(numconnections): ui.debug('imap', 'keepalive: processing connection %d of %d' % (i, numconnections)) imapobj = self.acquireconnection() ui.debug('imap', 'keepalive: connection %d acquired' % i) imapobjs.append(imapobj) thr = threadutil.ExitNotifyThread(target = imapobj.noop) thr.setDaemon(1) thr.start() threads.append(thr) ui.debug('imap', 'keepalive: thread started') ui.debug('imap', 'keepalive: joining threads') for thr in threads: # Make sure all the commands have completed. thr.join() ui.debug('imap', 'keepalive: releasing connections') for imapobj in imapobjs: self.releaseconnection(imapobj) ui.debug('imap', 'keepalive: bottom of loop') class ConfigedIMAPServer(IMAPServer): """This class is designed for easier initialization given a ConfigParser object and an account name. The passwordhash is used if passwords for certain accounts are known. If the password for this account is listed, it will be obtained from there.""" def __init__(self, repository, passwordhash = {}): """Initialize the object. If the account is not a tunnel, the password is required.""" self.repos = repository self.config = self.repos.getconfig() usetunnel = self.repos.getpreauthtunnel() if not usetunnel: host = self.repos.gethost() user = self.repos.getuser() port = self.repos.getport() ssl = self.repos.getssl() reference = self.repos.getreference() server = None password = None if repository.getname() in passwordhash: password = passwordhash[repository.getname()] # Connect to the remote server. if usetunnel: IMAPServer.__init__(self, self.config, self.repos.getname(), tunnel = usetunnel, reference = reference, maxconnections = self.repos.getmaxconnections()) else: if not password: password = self.repos.getpassword() IMAPServer.__init__(self, self.config, self.repos.getname(), user, password, host, port, ssl, self.repos.getmaxconnections(), reference = reference)