import logging
from re import match
import aiosmtplib
from channels.layers import get_channel_layer
from channels.db import database_sync_to_async
from django.core.files.base import ContentFile
from mail.models import Email, EventAddress, EmailAttachment
from notifications.templates import render_auto_reply
from notify_sessions.models import SystemEvent
from tickets.models import IssueThread
class SpecialMailException(Exception):
pass
def find_quoted_printable(s, marker):
positions = [i for i in range(len(s)) if s.lower().startswith('=?utf-8?' + marker + '?', i)]
for pos in positions:
end = s.find('?=', pos + 10)
if end == -1:
continue
yield pos, end + 3
def unescape_and_decode_quoted_printable(s):
import quopri
decoded = ''
last_end = 0
for start, end in find_quoted_printable(s, 'q'):
decoded += s[last_end:start]
decoded += quopri.decodestring(s[start + 10:end - 3]).decode('utf-8')
last_end = end
decoded += s[last_end:]
return decoded
def unescape_and_decode_base64(s):
import base64
decoded = ''
last_end = 0
for start, end in find_quoted_printable(s, 'b'):
decoded += s[last_end:start]
decoded += base64.b64decode(s[start + 10:end - 3]).decode('utf-8')
last_end = end
decoded += s[last_end:]
return decoded
def unescape_simplified_quoted_printable(s):
import quopri
return quopri.decodestring(s).decode('utf-8')
def collect_references(issue_thread):
mails = issue_thread.emails.order_by('timestamp')
references = []
for mail in mails:
if mail.reference:
references.append(mail.reference)
return references
def make_reply(reply_email, references=None, event=None):
from email.message import EmailMessage
from core.settings import MAIL_DOMAIN
event = event or "mail"
reply = EmailMessage()
reply["From"] = reply_email.sender
reply["To"] = reply_email.recipient
reply["Subject"] = reply_email.subject
reply["Reply-To"] = f"{event}@{MAIL_DOMAIN}"
if reply_email.in_reply_to:
reply["In-Reply-To"] = reply_email.in_reply_to
if reply_email.reference:
reply["Message-ID"] = reply_email.reference
else:
reply["Message-ID"] = reply_email.id + "@" + MAIL_DOMAIN
reply_email.reference = reply["Message-ID"]
reply_email.save()
if references:
reply["References"] = " ".join(references)
reply.set_content(reply_email.body)
return reply
def make_notification(message, to, title): # TODO where should replies to this go
from email.message import EmailMessage
from core.settings import MAIL_DOMAIN
notification = EmailMessage()
notification["From"] = "notifications@%s" % MAIL_DOMAIN
notification["To"] = to
notification["Subject"] = f"[C3LF Notification]%s" % title
# notification["Reply-To"] = f"{event}@{MAIL_DOMAIN}"
# notification["In-Reply-To"] = email.reference
# notification["Message-ID"] = email.id + "@" + MAIL_DOMAIN
notification.set_content(message)
return notification
async def send_smtp(message):
await aiosmtplib.send(message, hostname="127.0.0.1", port=25, use_tls=False, start_tls=False)
def find_active_issue_thread(in_reply_to, address, subject):
from re import match
uuid_match = match(r'^ticket\+([a-f0-9-]{36})@', address)
if uuid_match:
issue = IssueThread.objects.filter(uuid=uuid_match.group(1))
if issue.exists():
return issue.first(), False
reply_to = Email.objects.filter(reference=in_reply_to)
if reply_to.exists():
return reply_to.first().issue_thread, False
else:
issue = IssueThread.objects.create(name=subject)
return issue, True
def find_target_event(address):
try:
address_map = EventAddress.objects.get(address=address)
if address_map.event:
return address_map.event
except EventAddress.DoesNotExist:
pass
return None
def parse_email_body(raw, log=None):
import email
from hashlib import sha256
attachments = []
parsed = email.message_from_bytes(raw)
body = ""
if parsed.is_multipart():
for part in parsed.walk():
ctype = part.get_content_type()
cdispo = str(part.get('Content-Disposition'))
# skip any text/plain (txt) attachments
if ctype == 'text/plain' and 'attachment' not in cdispo:
segment = part.get_payload()
if not segment:
continue
segment = unescape_and_decode_quoted_printable(segment)
segment = unescape_and_decode_base64(segment)
if part.get('Content-Transfer-Encoding') == 'quoted-printable':
segment = unescape_simplified_quoted_printable(segment)
log.debug(segment)
body = body + segment
elif 'attachment' in cdispo or 'inline' in cdispo:
file = ContentFile(part.get_payload(decode=True))
chash = sha256(file.read()).hexdigest()
name = part.get_filename()
if name is None:
name = "unnamed"
attachment, _ = EmailAttachment.objects.get_or_create(
name=name, mime_type=ctype, file=file, hash=chash)
attachment.save()
attachments.append(attachment)
if 'inline' in cdispo:
body = body + f'
'
log.info("Image %s %s", ctype, attachment.id)
else:
log.info("Attachment %s %s", ctype, cdispo)
else:
if parsed.get_content_type() == 'text/plain':
body = parsed.get_payload()
elif parsed.get_content_type() == 'text/html':
from bs4 import BeautifulSoup
import re
body = parsed.get_payload()
soup = BeautifulSoup(body, 'html.parser')
body = re.sub(r'([\r\n]+.?)*[\r\n]', r'\n', soup.get_text()).strip('\n')
else:
log.warning("Unknown content type %s", parsed.get_content_type())
body = "Unknown content type"
body = unescape_and_decode_quoted_printable(body)
body = unescape_and_decode_base64(body)
if parsed.get('Content-Transfer-Encoding') == 'quoted-printable':
body = unescape_simplified_quoted_printable(body)
log.debug(body)
return parsed, body, attachments
@database_sync_to_async
def receive_email(envelope, log=None):
parsed, body, attachments = parse_email_body(envelope.content, log)
header_from = parsed.get('From')
header_to = parsed.get('To')
header_in_reply_to = parsed.get('In-Reply-To')
header_message_id = parsed.get('Message-ID')
# if header_from != envelope.mail_from:
# log.warning("Header from does not match envelope from")
# log.info(f"Header from: {header_from}, envelope from: {envelope.mail_from}")
#
# if header_to != envelope.rcpt_tos[0]:
# log.warning("Header to does not match envelope to")
# log.info(f"Header to: {header_to}, envelope to: {envelope.rcpt_tos[0]}")
# handle undelivered mail header_from : 'Mail Delivery System ") == "":
log.warning("Ignoring mailer daemon")
raise SpecialMailException("Ignoring mailer daemon")
if Email.objects.filter(reference=header_message_id).exists(): # break before issue thread is created
log.warning("Email already exists")
raise Exception("Email already exists")
recipient = envelope.rcpt_tos[0].lower() if envelope.rcpt_tos else header_to.lower()
sender = envelope.mail_from if envelope.mail_from else header_from
subject = parsed.get('Subject')
if not subject:
subject = "No subject"
subject = unescape_and_decode_quoted_printable(subject)
subject = unescape_and_decode_base64(subject)
target_event = find_target_event(recipient)
active_issue_thread, new = find_active_issue_thread(header_in_reply_to, recipient, subject)
email = Email.objects.create(
sender=sender, recipient=recipient, body=body, subject=subject, reference=header_message_id,
in_reply_to=header_in_reply_to, raw=envelope.content, event=target_event,
issue_thread=active_issue_thread)
for attachment in attachments:
email.attachments.add(attachment)
email.save()
reply = None
if new:
# auto reply if new issue
references = collect_references(active_issue_thread)
if not sender.startswith('noreply'):
subject = f"Re: {subject} [#{active_issue_thread.short_uuid()}]"
body = render_auto_reply(active_issue_thread)
reply_email = Email.objects.create(
sender=recipient, recipient=sender, body=body, subject=subject,
in_reply_to=header_message_id, event=target_event, issue_thread=active_issue_thread)
reply = make_reply(reply_email, references, event=target_event.slug if target_event else None)
else:
# change state if not new
if active_issue_thread.state != 'pending_new':
active_issue_thread.state = 'pending_open'
active_issue_thread.save()
return email, new, reply, active_issue_thread
class LMTPHandler:
async def handle_RCPT(self, server, session, envelope, address, rcpt_options):
from core.settings import MAIL_DOMAIN
address = address.lower()
if not address.endswith('@' + MAIL_DOMAIN):
return '550 not relaying to that domain'
envelope.rcpt_tos.append(address)
return '250 OK'
async def handle_DATA(self, server, session, envelope):
log = logging.getLogger('mail.log')
log.setLevel(logging.DEBUG)
log.info('Message from %s' % envelope.mail_from)
log.info('Message for %s' % envelope.rcpt_tos)
log.info('Message data:\n')
content = None
try:
content = envelope.content
email, new, reply, thread = await receive_email(envelope, log)
log.info(f"Created email {email.id}")
systemevent = await database_sync_to_async(SystemEvent.objects.create)(type='email received',
reference=email.id)
log.info(f"Created system event {systemevent.id}")
channel_layer = get_channel_layer()
await channel_layer.group_send(
'general', {"type": "generic.event", "name": "send_message_to_frontend", "event_id": systemevent.id,
"message": "email received"})
log.info(f"Sent message to frontend")
if new and reply:
log.info('Sending message to %s' % reply['To'])
await send_smtp(reply)
log.info("Sent auto reply")
if thread:
await channel_layer.group_send(
'general', {"type": "generic.event", "name": "user_notification", "event_id": systemevent.id,
"ticket_id": thread.id, "new": new})
else:
print("No thread found")
return '250 Message accepted for delivery'
except SpecialMailException as e:
import uuid
random_filename = 'special-' + str(uuid.uuid4())
with open(random_filename, 'wb') as f:
f.write(content)
log.warning(f"Special mail exception: {e} saved to {random_filename}")
return '250 Message accepted for delivery'
except Exception as e:
from hashlib import sha256
random_filename = 'mail-' + sha256(content).hexdigest()
with open(random_filename, 'wb') as f:
f.write(content)
log.error(f"Saved email to {random_filename} because of error %s (%s)", e, type(e))
return '451 Internal server error'