# Maildir folder support # Copyright (C) 2002-2016 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 socket import time import re import os import six from sys import exc_info from threading import Lock try: from hashlib import md5 except ImportError: from md5 import md5 try: # python 2.6 has set() built in set except NameError: from sets import Set as set from offlineimap import OfflineImapError, emailutil from .Base import BaseFolder # Find the UID in a message filename re_uidmatch = re.compile(',U=(\d+)') # Find a numeric timestamp in a string (filename prefix) re_timestampmatch = re.compile('(\d+)'); timehash = {} timelock = Lock() def _gettimeseq(date=None): global timehash, timelock timelock.acquire() try: if date is None: date = int(time.time()) if date in timehash: timehash[date] += 1 else: timehash[date] = 0 return (date, timehash[date]) finally: timelock.release() class MaildirFolder(BaseFolder): def __init__(self, root, name, sep, repository): self.sep = sep # needs to be set before super().__init__ super(MaildirFolder, self).__init__(name, repository) self.root = root # check if we should use a different infosep to support Win file systems self.wincompatible = self.config.getdefaultboolean( "Account "+self.accountname, "maildir-windows-compatible", False) self.infosep = '!' if self.wincompatible else ':' """infosep is the separator between maildir name and flag appendix""" self.re_flagmatch = re.compile('%s2,(\w*)'% self.infosep) #self.ui is set in BaseFolder.init() # Everything up to the first comma or colon (or ! if Windows): self.re_prefixmatch = re.compile('([^'+ self.infosep + ',]*)') # folder's md, so we can match with recorded file md5 for validity. self._foldermd5 = md5(self.getvisiblename()).hexdigest() # Cache the full folder path, as we use getfullname() very often. self._fullname = os.path.join(self.getroot(), self.getname()) # Modification time from 'Date' header. utime_from_header_global = self.config.getdefaultboolean( "general", "utime_from_header", False) self._utime_from_header = self.config.getdefaultboolean( self.repoconfname, "utime_from_header", utime_from_header_global) # Interface from BaseFolder def getfullname(self): """Return the absolute file path to the Maildir folder (sans cur|new)""" return self._fullname # Interface from BaseFolder def get_uidvalidity(self): """Retrieve the current connections UIDVALIDITY value Maildirs have no notion of uidvalidity, so we just return a magic token.""" return 42 def _iswithintime(self, messagename, date): """Check to see if the given message is newer than date (a time_struct) according to the maildir name which should begin with a timestamp.""" timestampmatch = re_timestampmatch.search(messagename) if not timestampmatch: return True timestampstr = timestampmatch.group() timestamplong = int(timestampstr) if(timestamplong < time.mktime(date)): return False else: return True def _parse_filename(self, filename): """Returns a messages file name components Receives the file name (without path) of a msg. Usual format is '<%d_%d.%d.%s>,U=<%d>,FMD5=<%s>:2,' (pointy brackets denoting the various components). If FMD5 does not correspond with the current folder MD5, we will return None for the UID & FMD5 (as it is not valid in this folder). If UID or FMD5 can not be detected, we return `None` for the respective element. If flags are empty or cannot be detected, we return an empty flags list. :returns: (prefix, UID, FMD5, flags). UID is a numeric "long" type. flags is a set() of Maildir flags. """ prefix, uid, fmd5, flags = None, None, None, set() prefixmatch = self.re_prefixmatch.match(filename) if prefixmatch: prefix = prefixmatch.group(1) folderstr = ',FMD5=%s'% self._foldermd5 foldermatch = folderstr in filename # If there was no folder MD5 specified, or if it mismatches, # assume it is a foreign (new) message and ret: uid, fmd5 = None, None # XXX: This is wrong behaviour: if FMD5 is missing or mismatches, assume # the mail is new and **fix UID to None** to avoid any conflict. # XXX: If UID is missing, I have no idea what FMD5 can do. Should be # fixed to None in this case, too. if foldermatch: uidmatch = re_uidmatch.search(filename) if uidmatch: uid = int(uidmatch.group(1)) flagmatch = self.re_flagmatch.search(filename) if flagmatch: flags = set((c for c in flagmatch.group(1))) return prefix, uid, fmd5, flags def _scanfolder(self, min_date=None, min_uid=None): """Cache the message list from a Maildir. If min_date is set, this finds the min UID of all messages newer than min_date and uses it as the real cutoff for considering messages. This handles the edge cases where the date is much earlier than messages with similar UID's (e.g. the UID was reassigned much later). Maildir flags are: D (draft) F (flagged) R (replied) S (seen) T (trashed), plus lower-case letters for custom flags. :returns: dict that can be used as self.messagelist. """ maxsize = self.getmaxsize() retval = {} files = [] nouidcounter = -1 # Messages without UIDs get negative UIDs. for dirannex in ['new', 'cur']: fulldirname = os.path.join(self.getfullname(), dirannex) files.extend((dirannex, filename) for filename in os.listdir(fulldirname)) date_excludees = {} for dirannex, filename in files: if filename.startswith('.'): continue # Ignore dot files. # We store just dirannex and filename, ie 'cur/123...' filepath = os.path.join(dirannex, filename) # Check maxsize if this message should be considered. if maxsize and (os.path.getsize( os.path.join(self.getfullname(), filepath)) > maxsize): continue prefix, uid, fmd5, flags = self._parse_filename(filename) if uid is None: # Assign negative uid to upload it. uid = nouidcounter nouidcounter -= 1 else: # It comes from our folder. uidmatch = re_uidmatch.search(filename) uid = None if not uidmatch: uid = nouidcounter nouidcounter -= 1 else: uid = int(uidmatch.group(1)) if min_uid != None and uid > 0 and uid < min_uid: continue if min_date != None and not self._iswithintime(filename, min_date): # Keep track of messages outside of the time limit, because they # still might have UID > min(UIDs of within-min_date). We hit # this case for maxage if any message had a known/valid datetime # and was re-uploaded because the UID in the filename got lost # (e.g. local copy/move). On next sync, it was assigned a new # UID from the server and will be included in the SEARCH # condition. So, we must re-include them later in this method # in order to avoid inconsistent lists of messages. date_excludees[uid] = self.msglist_item_initializer(uid) date_excludees[uid]['flags'] = flags date_excludees[uid]['filename'] = filepath else: # 'filename' is 'dirannex/filename', e.g. cur/123,U=1,FMD5=1:2,S retval[uid] = self.msglist_item_initializer(uid) retval[uid]['flags'] = flags retval[uid]['filename'] = filepath if min_date != None: # Re-include messages with high enough uid's. positive_uids = [uid for uid in retval if uid > 0] if positive_uids: min_uid = min(positive_uids) for uid in date_excludees.keys(): if uid > min_uid: # This message was originally excluded because of # its date. It is re-included now because we want all # messages with UID > min_uid. retval[uid] = date_excludees[uid] return retval # Interface from BaseFolder def quickchanged(self, statusfolder): """Returns True if the Maildir has changed Assumes cachemessagelist() has already been called """ # Folder has different uids than statusfolder => TRUE. if sorted(self.getmessageuidlist()) != \ sorted(statusfolder.getmessageuidlist()): return True # Also check for flag changes, it's quick on a Maildir. for (uid, message) in self.getmessagelist().items(): if message['flags'] != statusfolder.getmessageflags(uid): return True return False # Nope, nothing changed. # Interface from BaseFolder def msglist_item_initializer(self, uid): return {'flags': set(), 'filename': '/no-dir/no-such-file/'} # Interface from BaseFolder def cachemessagelist(self, min_date=None, min_uid=None): if self.ismessagelistempty(): self.ui.loadmessagelist(self.repository, self) self.messagelist = self._scanfolder(min_date=min_date, min_uid=min_uid) self.ui.messagelistloaded(self.repository, self, self.getmessagecount()) # Interface from BaseFolder def getmessage(self, uid): """Return the content of the message.""" filename = self.messagelist[uid]['filename'] filepath = os.path.join(self.getfullname(), filename) file = open(filepath, 'rt') retval = file.read() file.close() #TODO: WHY are we replacing \r\n with \n here? And why do we # read it as text? return retval.replace("\r\n", "\n") # Interface from BaseFolder def getmessagetime(self, uid): filename = self.messagelist[uid]['filename'] filepath = os.path.join(self.getfullname(), filename) return os.path.getmtime(filepath) def new_message_filename(self, uid, flags=set(), date=None): """Creates a new unique Maildir filename :param uid: The UID`None`, or a set of maildir flags :param flags: A set of maildir flags :returns: String containing unique message filename""" timeval, timeseq = _gettimeseq(date) return '%d_%d.%d.%s,U=%d,FMD5=%s%s2,%s'% \ (timeval, timeseq, os.getpid(), socket.gethostname(), uid, self._foldermd5, self.infosep, ''.join(sorted(flags))) def save_to_tmp_file(self, filename, content): """Saves given content to the named temporary file in the 'tmp' subdirectory of $CWD. Arguments: - filename: name of the temporary file; - content: data to be saved. Returns: relative path to the temporary file that was created.""" tmpname = os.path.join('tmp', filename) # Open file and write it out. # XXX: why do we need to loop 7 times? tries = 7 while tries: tries = tries - 1 try: fd = os.open(os.path.join(self.getfullname(), tmpname), os.O_EXCL|os.O_CREAT|os.O_WRONLY, 0o666) break except OSError as e: if not hasattr(e, 'EEXIST'): raise if e.errno == e.EEXIST: if tries: time.sleep(0.23) continue severity = OfflineImapError.ERROR.MESSAGE six.reraise(OfflineImapError, OfflineImapError( "Unique filename %s already exists."% filename, severity), exc_info()[2]) else: raise fd = os.fdopen(fd, 'wt') fd.write(content) # Make sure the data hits the disk. fd.flush() if self.dofsync(): os.fsync(fd) fd.close() return tmpname # Interface from BaseFolder def savemessage(self, uid, content, flags, rtime): """Writes a new message, with the specified uid. See folder/Base for detail. Note that savemessage() does not check against dryrun settings, so you need to ensure that savemessage is never called in a dryrun mode.""" # This function only ever saves to tmp/, # but it calls savemessageflags() to actually save to cur/ or new/. self.ui.savemessage('maildir', uid, flags, self) if uid < 0: # We cannot assign a new uid. return uid if uid in self.messagelist: # We already have it, just update flags. self.savemessageflags(uid, flags) return uid # Otherwise, save the message in tmp/ and then call savemessageflags() # to give it a permanent home. tmpdir = os.path.join(self.getfullname(), 'tmp') # Use the mail timestamp given by either Date or Delivery-date mail # headers. message_timestamp = None if self._filename_use_mail_timestamp: try: message_timestamp = emailutil.get_message_date(content, 'Date') if message_timestamp is None: # Give a try with Delivery-date date = emailutil.get_message_date(content, 'Delivery-date') except Exception as e: # This should never happen. from email.Parser import Parser from offlineimap.ui import getglobalui datestr = Parser().parsestr(content, True).get("Date") ui = getglobalui() ui.warn("UID %d has invalid date %s: %s\n" "Not using message timestamp as file prefix"% (uid, datestr, e)) # No need to check if date is None here since it would # be overridden by _gettimeseq. messagename = self.new_message_filename(uid, flags, date=message_timestamp) tmpname = self.save_to_tmp_file(messagename, content) if self._utime_from_header is True: try: date = emailutil.get_message_date(content, 'Date') if date is not None: os.utime(os.path.join(self.getfullname(), tmpname), (date, date)) # In case date is wrongly so far into the future as to be > max # int32. except Exception as e: from email.Parser import Parser from offlineimap.ui import getglobalui datestr = Parser().parsestr(content, True).get("Date") ui = getglobalui() ui.warn("UID %d has invalid date %s: %s\n" "Not changing file modification time"% (uid, datestr, e)) self.messagelist[uid] = self.msglist_item_initializer(uid) self.messagelist[uid]['flags'] = flags self.messagelist[uid]['filename'] = tmpname # savemessageflags moves msg to 'cur' or 'new' as appropriate. self.savemessageflags(uid, flags) self.ui.debug('maildir', 'savemessage: returning uid %d' % uid) return uid # Interface from BaseFolder def getmessageflags(self, uid): return self.messagelist[uid]['flags'] # Interface from BaseFolder def savemessageflags(self, uid, flags): """Sets the specified message's flags to the given set. This function moves the message to the cur or new subdir, depending on the 'S'een flag. Note that this function does not check against dryrun settings, so you need to ensure that it is never called in a dryrun mode.""" assert uid in self.messagelist oldfilename = self.messagelist[uid]['filename'] dir_prefix, filename = os.path.split(oldfilename) # If a message has been seen, it goes into 'cur' dir_prefix = 'cur' if 'S' in flags else 'new' if flags != self.messagelist[uid]['flags']: # Flags have actually changed, construct new filename Strip # off existing infostring infomatch = self.re_flagmatch.search(filename) if infomatch: filename = filename[:-len(infomatch.group())] #strip off infostr = '%s2,%s'% (self.infosep, ''.join(sorted(flags))) filename += infostr newfilename = os.path.join(dir_prefix, filename) if (newfilename != oldfilename): try: os.rename(os.path.join(self.getfullname(), oldfilename), os.path.join(self.getfullname(), newfilename)) except OSError as e: six.reraise(OfflineImapError, OfflineImapError( "Can't rename file '%s' to '%s': %s"% (oldfilename, newfilename, e[1]), OfflineImapError.ERROR.FOLDER), exc_info()[2]) self.messagelist[uid]['flags'] = flags self.messagelist[uid]['filename'] = newfilename # Interface from BaseFolder def change_message_uid(self, uid, new_uid): """Change the message from existing uid to new_uid This will not update the statusfolder UID, you need to do that yourself. :param new_uid: (optional) If given, the old UID will be changed to a new UID. The Maildir backend can implement this as an efficient rename. """ if not uid in self.messagelist: raise OfflineImapError("Cannot change unknown Maildir UID %s"% uid, OfflineImapError.ERROR.MESSAGE) if uid == new_uid: return oldfilename = self.messagelist[uid]['filename'] dir_prefix, filename = os.path.split(oldfilename) flags = self.getmessageflags(uid) newfilename = os.path.join(dir_prefix, self.new_message_filename(new_uid, flags)) os.rename(os.path.join(self.getfullname(), oldfilename), os.path.join(self.getfullname(), newfilename)) self.messagelist[new_uid] = self.messagelist[uid] self.messagelist[new_uid]['filename'] = newfilename del self.messagelist[uid] # Interface from BaseFolder def deletemessage(self, uid): """Unlinks a message file from the Maildir. :param uid: UID of a mail message :type uid: String :return: Nothing, or an Exception if UID but no corresponding file found. """ filename = self.messagelist[uid]['filename'] filepath = os.path.join(self.getfullname(), filename) try: os.unlink(filepath) except OSError: # Can't find the file -- maybe already deleted? newmsglist = self._scanfolder() if uid in newmsglist: # Nope, try new filename. filename = newmsglist[uid]['filename'] filepath = os.path.join(self.getfullname(), filename) os.unlink(filepath) # Yep -- return. del(self.messagelist[uid]) def migratefmd5(self, dryrun=False): """Migrate FMD5 hashes from versions prior to 6.3.5 :param dryrun: Run in dry run mode :type fix: Boolean :return: None """ oldfmd5 = md5(self.name).hexdigest() msglist = self._scanfolder() for mkey, mvalue in msglist.items(): filename = os.path.join(self.getfullname(), mvalue['filename']) match = re.search("FMD5=([a-fA-F0-9]+)", filename) if match is None: self.ui.debug("maildir", "File `%s' doesn't have an FMD5 assigned" % filename) elif match.group(1) == oldfmd5: self.ui.info("Migrating file `%s' to FMD5 `%s'" % (filename, self._foldermd5)) if not dryrun: newfilename = filename.replace( "FMD5=" + match.group(1), "FMD5=" + self._foldermd5) try: os.rename(filename, newfilename) except OSError as e: six.reraise(OfflineImapError, OfflineImapError( "Can't rename file '%s' to '%s': %s"% (filename, newfilename, e[1]), OfflineImapError.ERROR.FOLDER), exc_info()[2]) elif match.group(1) != self._foldermd5: self.ui.warn(("Inconsistent FMD5 for file `%s':" " Neither `%s' nor `%s' found") % (filename, oldfmd5, self._foldermd5))