# Copyright (C) 1998-2003 by the Free Software Foundation, Inc. # # 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. """Cook a message's Subject header. """ from __future__ import nested_scopes import re from types import UnicodeType from email.Charset import Charset from email.Header import Header, decode_header from email.Utils import parseaddr, formataddr, getaddresses from Mailman import mm_cfg from Mailman import Utils from Mailman.i18n import _ from Mailman.Logging.Syslog import syslog CONTINUATION = ',\n\t' COMMASPACE = ', ' MAXLINELEN = 78 def _isunicode(s): return isinstance(s, UnicodeType) def uheader(mlist, s, header_name=None, continuation_ws='\t', maxlinelen=None): # Get the charset to encode the string in. If this is us-ascii, we'll use # iso-8859-1 instead, just to get a little extra coverage, and because the # Header class tries us-ascii first anyway. charset = Utils.GetCharSet(mlist.preferred_language) if charset == 'us-ascii': charset = 'iso-8859-1' charset = Charset(charset) # Convert the string to unicode so Header will do the 3-charset encoding. # If s is a byte string and there are funky characters in it that don't # match the charset, we might as well replace them now. if not _isunicode(s): codec = charset.input_codec or 'ascii' s = unicode(s, codec, 'replace') # We purposefully leave no space b/w prefix and subject! return Header(s, charset, maxlinelen, header_name, continuation_ws) def process(mlist, msg, msgdata): # Set the "X-Ack: no" header if noack flag is set. if msgdata.get('noack'): del msg['x-ack'] msg['X-Ack'] = 'no' # Because we're going to modify various important headers in the email # message, we want to save some of the information in the msgdata # dictionary for later. Specifically, the sender header will get waxed, # but we need it for the Acknowledge module later. msgdata['original_sender'] = msg.get_sender() # VirginRunner sets _fasttrack for internally crafted messages. fasttrack = msgdata.get('_fasttrack') if not msgdata.get('isdigest') and not fasttrack: prefix_subject(mlist, msg, msgdata) # Mark message so we know we've been here, but leave any existing # X-BeenThere's intact. msg['X-BeenThere'] = mlist.GetListEmail() # Add Precedence: and other useful headers. None of these are standard # and finding information on some of them are fairly difficult. Some are # just common practice, and we'll add more here as they become necessary. # Good places to look are: # # http://www.dsv.su.se/~jpalme/ietf/jp-ietf-home.html # http://www.faqs.org/rfcs/rfc2076.html # # None of these headers are added if they already exist. BAW: some # consider the advertising of this a security breach. I.e. if there are # known exploits in a particular version of Mailman and we know a site is # using such an old version, they may be vulnerable. It's too easy to # edit the code to add a configuration variable to handle this. if not msg.has_key('x-mailman-version'): msg['X-Mailman-Version'] = mm_cfg.VERSION # We set "Precedence: list" because this is the recommendation from the # sendmail docs, the most authoritative source of this header's semantics. if not msg.has_key('precedence'): msg['Precedence'] = 'list' # Reply-To: munging. Do not do this if the message is "fast tracked", # meaning it is internally crafted and delivered to a specific user. BAW: # Yuck, I really hate this feature but I've caved under the sheer pressure # of the (very vocal) folks want it. OTOH, RFC 2822 allows Reply-To: to # be a list of addresses, so instead of replacing the original, simply # augment it. RFC 2822 allows max one Reply-To: header so collapse them # if we're adding a value, otherwise don't touch it. (Should we collapse # in all cases?) if not fasttrack: # A convenience function, requires nested scopes. pair is (name, addr) new = [] d = {} def add(pair): lcaddr = pair[1].lower() if d.has_key(lcaddr): return d[lcaddr] = pair new.append(pair) # List admin wants an explicit Reply-To: added if mlist.reply_goes_to_list == 2: add(parseaddr(mlist.reply_to_address)) # If we're not first stripping existing Reply-To: then we need to add # the original Reply-To:'s to the list we're building up. In both # cases we'll zap the existing field because RFC 2822 says max one is # allowed. if not mlist.first_strip_reply_to: orig = msg.get_all('reply-to', []) for pair in getaddresses(orig): add(pair) # Set Reply-To: header to point back to this list. Add this last # because some folks think that some MUAs make it easier to delete # addresses from the right than from the left. if mlist.reply_goes_to_list == 1: i18ndesc = uheader(mlist, mlist.description) add((str(i18ndesc), mlist.GetListEmail())) del msg['reply-to'] # Don't put Reply-To: back if there's nothing to add! if new: # Preserve order msg['Reply-To'] = COMMASPACE.join( [formataddr(pair) for pair in new]) # The To field normally contains the list posting address. However # when messages are fully personalized, that header will get # overwritten with the address of the recipient. We need to get the # posting address in one of the recipient headers or they won't be # able to reply back to the list. It's possible the posting address # was munged into the Reply-To header, but if not, we'll add it to a # Cc header. BAW: should we force it into a Reply-To header in the # above code? if mlist.personalize == 2 and mlist.reply_goes_to_list <> 1: # Watch out for existing Cc headers, merge, and remove dups. Note # that RFC 2822 says only zero or one Cc header is allowed. new = [] d = {} for pair in getaddresses(msg.get_all('cc', [])): add(pair) i18ndesc = uheader(mlist, mlist.description) add((str(i18ndesc), mlist.GetListEmail())) del msg['Cc'] msg['Cc'] = COMMASPACE.join([formataddr(pair) for pair in new]) # Add list-specific headers as defined in RFC 2369 and RFC 2919, but only # if the message is being crafted for a specific list (e.g. not for the # password reminders). # # BAW: Some people really hate the List-* headers. It seems that the free # version of Eudora (possibly on for some platforms) does not hide these # headers by default, pissing off their users. Too bad. Fix the MUAs. if msgdata.get('_nolist') or not mlist.include_rfc2369_headers: return # This will act like an email address for purposes of formataddr() listid = '%s.%s' % (mlist.internal_name(), mlist.host_name) if mlist.description: # Don't wrap the header since here we just want to get it properly RFC # 2047 encoded. h = uheader(mlist, mlist.description, 'List-Id', maxlinelen=10000) desc = str(h) else: desc = '' listid_h = formataddr((desc, listid)) # BAW: I think the message object should handle any necessary wrapping. del msg['list-id'] msg['List-Id'] = listid_h # For internally crafted messages, we # also add a (nonstandard), "X-List-Administrivia: yes" header. For all # others (i.e. those coming from list posts), we adda a bunch of other RFC # 2369 headers. requestaddr = mlist.GetRequestEmail() subfieldfmt = '<%s>, <mailto:%s?subject=%ssubscribe>' listinfo = mlist.GetScriptURL('listinfo', absolute=1) headers = {} if msgdata.get('reduced_list_headers'): headers['X-List-Administrivia'] = 'yes' else: headers.update({ 'List-Help' : '<mailto:%s?subject=help>' % requestaddr, 'List-Unsubscribe': subfieldfmt % (listinfo, requestaddr, 'un'), 'List-Subscribe' : subfieldfmt % (listinfo, requestaddr, ''), }) # List-Post: is controlled by a separate attribute if mlist.include_list_post_header: headers['List-Post'] = '<mailto:%s>' % mlist.GetListEmail() # Add this header if we're archiving if mlist.archive: archiveurl = mlist.GetBaseArchiveURL() if archiveurl.endswith('/'): archiveurl = archiveurl[:-1] headers['List-Archive'] = '<%s>' % archiveurl # First we delete any pre-existing headers because the RFC permits only # one copy of each, and we want to be sure it's ours. for h, v in headers.items(): del msg[h] # Wrap these lines if they are too long. 78 character width probably # shouldn't be hardcoded, but is at least text-MUA friendly. The # adding of 2 is for the colon-space separator. if len(h) + 2 + len(v) > 78: v = CONTINUATION.join(v.split(', ')) msg[h] = v def prefix_subject(mlist, msg, msgdata): # Add the subject prefix unless the message is a digest or is being fast # tracked (e.g. internally crafted, delivered to a single user such as the # list admin). prefix = mlist.subject_prefix subject = msg.get('subject', '') # Try to figure out what the continuation_ws is for the header if isinstance(subject, Header): lines = str(subject).splitlines() else: lines = subject.splitlines() ws = '\t' if len(lines) > 1 and lines[1] and lines[1][0] in ' \t': ws = lines[1][0] msgdata['origsubj'] = subject if not subject: subject = _('(no subject)') # The header may be multilingual; decode it from base64/quopri and search # each chunk for the prefix. BAW: Note that if the prefix contains spaces # and each word of the prefix is encoded in a different chunk in the # header, we won't find it. I think in practice that's unlikely though. headerbits = decode_header(subject) if prefix and subject: pattern = re.escape(prefix.strip()) for decodedsubj, charset in headerbits: if re.search(pattern, decodedsubj, re.IGNORECASE): # The subject's already got the prefix, so don't change it return del msg['subject'] # Get the header as a Header instance, with proper unicode conversion h = uheader(mlist, prefix, 'Subject', continuation_ws=ws) for s, c in headerbits: # Once again, convert the string to unicode. if c is None: c = Charset('iso-8859-1') if not isinstance(c, Charset): c = Charset(c) if not _isunicode(s): codec = c.input_codec or 'ascii' try: s = unicode(s, codec, 'replace') except LookupError: # Unknown codec, is this default reasonable? s = unicode(s, Utils.GetCharSet(mlist.preferred_language), 'replace') h.append(s, c) msg['Subject'] = h