# 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'):
# 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, header_name=header_name,
continuation_ws=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
# Pre-calculate
listid = '<%s.%s>' % (mlist.internal_name(), mlist.host_name)
if mlist.description:
# Make sure description is properly i18n'd
listid_h = uheader(mlist, mlist.description, 'List-Id')
listid_h.append(' ' + listid, 'us-ascii')
else:
# For wrapping
listid_h = Header(listid, 'us-ascii', header_name='List-Id')
# We always add a List-ID: header.
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
