zulip/zerver/lib/email_mirror.py

269 lines
9.3 KiB
Python

from __future__ import absolute_import
import logging
import re
from email.header import decode_header
from django.conf import settings
from zerver.lib.actions import decode_email_address, internal_send_message
from zerver.lib.notifications import convert_html_to_markdown
from zerver.lib.redis_utils import get_redis_client
from zerver.lib.upload import upload_message_image
from zerver.lib.utils import generate_random_token
from zerver.models import Stream, Recipient, get_user_profile_by_email, \
get_user_profile_by_id, get_display_recipient
logger = logging.getLogger(__name__)
def redact_stream(error_message):
domain = settings.EMAIL_GATEWAY_PATTERN.rsplit('@')[-1]
stream_match = re.search(r'\b(.*?)@' + domain, error_message)
if stream_match:
stream_name = stream_match.groups()[0]
return error_message.replace(stream_name, "X" * len(stream_name))
return error_message
def report_to_zulip(error_message):
error_stream = Stream.objects.get(name="errors", realm__domain=settings.ADMIN_DOMAIN)
send_zulip(error_stream, "email mirror error",
"""~~~\n%s\n~~~""" % (error_message,))
def log_and_report(email_message, error_message, debug_info):
scrubbed_error = "Sender: %s\n%s" % (email_message.get("From"),
redact_stream(error_message))
if "to" in debug_info:
scrubbed_error = "Stream: %s\n%s" % (redact_stream(debug_info["to"]),
scrubbed_error)
if "stream" in debug_info:
scrubbed_error = "Realm: %s\n%s" % (debug_info["stream"].realm.domain,
scrubbed_error)
logger.error(scrubbed_error)
report_to_zulip(scrubbed_error)
# Temporary missed message addresses
redis_client = get_redis_client()
def missed_message_redis_key(token):
return 'missed_message:' + token
def is_missed_message_address(address):
local_part = address.split('@')[0]
return local_part.startswith('mm') and len(local_part) == 34
def get_missed_message_token_from_address(address):
local_part = address.split('@')[0]
if not address.startswith('mm') and len(address) != 34:
raise ZulipEmailForwardError('Could not parse missed message address')
return local_part[2:]
def create_missed_message_address(user_profile, message):
data = {
'user_profile_id': user_profile.id,
'recipient_id': message.recipient_id,
'subject': message.subject,
}
while True:
token = generate_random_token(32)
key = missed_message_redis_key(token)
if redis_client.hsetnx(key, 'uses_left', 1):
break
with redis_client.pipeline() as pipeline:
pipeline.hmset(key, data)
pipeline.expire(key, 60 * 60 * 24 * 5)
pipeline.execute()
address = 'mm' + token
return settings.EMAIL_GATEWAY_PATTERN % (address, )
def mark_missed_message_address_as_used(address):
token = get_missed_message_token_from_address(address)
key = missed_message_redis_key(token)
with redis_client.pipeline() as pipeline:
pipeline.hincrby(key, 'uses_left', -1)
pipeline.expire(key, 60 * 60 * 24 * 5)
new_value = pipeline.execute()[0]
if new_value < 0:
redis_client.delete(key)
raise ZulipEmailForwardError('Missed message address has already been used')
def send_to_missed_message_address(address, message):
token = get_missed_message_token_from_address(address)
key = missed_message_redis_key(token)
result = redis_client.hmget(key, 'user_profile_id', 'recipient_id', 'subject')
if not all(result):
raise ZulipEmailForwardError('Missing missed message address data')
user_profile_id, recipient_id, subject = result
user_profile = get_user_profile_by_id(user_profile_id)
recipient = Recipient.objects.get(id=recipient_id)
display_recipient = get_display_recipient(recipient)
body = filter_footer(extract_body(message))
body += extract_and_upload_attachments(message, user_profile.realm)
if not body:
body = '(No email body)'
internal_send_message(user_profile.email, recipient.type_name(),
display_recipient, subject, body)
## Sending the Zulip ##
class ZulipEmailForwardError(Exception):
pass
def send_zulip(stream, topic, content):
internal_send_message(
settings.EMAIL_GATEWAY_BOT,
"stream",
stream.name,
topic[:60],
content[:2000],
stream.realm)
def valid_stream(stream_name, token):
try:
stream = Stream.objects.get(email_token=token)
return stream.name.lower() == stream_name.lower()
except Stream.DoesNotExist:
return False
def get_message_part_by_type(message, content_type):
charsets = message.get_charsets()
for idx, part in enumerate(message.walk()):
if part.get_content_type() == content_type:
content = part.get_payload(decode=True)
if charsets[idx]:
content = content.decode(charsets[idx], errors="ignore")
return content
def extract_body(message):
# If the message contains a plaintext version of the body, use
# that.
plaintext_content = get_message_part_by_type(message, "text/plain")
if plaintext_content:
return plaintext_content
# If we only have an HTML version, try to make that look nice.
html_content = get_message_part_by_type(message, "text/html")
if html_content:
return convert_html_to_markdown(html_content)
raise ZulipEmailForwardError("Unable to find plaintext or HTML message body")
def filter_footer(text):
# Try to filter out obvious footers.
possible_footers = filter(lambda line: line.strip().startswith("--"),
text.split("\n"))
if len(possible_footers) != 1:
# Be conservative and don't try to scrub content if there
# isn't a trivial footer structure.
return text
return text.partition("--")[0].strip()
def extract_and_upload_attachments(message, realm):
user_profile = get_user_profile_by_email(settings.EMAIL_GATEWAY_BOT)
attachment_links = []
payload = message.get_payload()
if not isinstance(payload, list):
# This is not a multipart message, so it can't contain attachments.
return ""
for part in payload:
content_type = part.get_content_type()
filename = part.get_filename()
if filename:
s3_url = upload_message_image(filename, content_type,
part.get_payload(decode=True),
user_profile,
target_realm=realm)
formatted_link = "[%s](%s)" % (filename, s3_url)
attachment_links.append(formatted_link)
return "\n".join(attachment_links)
def extract_and_validate(email):
try:
stream_name, token = decode_email_address(email)
except (TypeError, ValueError):
raise ZulipEmailForwardError("Malformed email recipient " + email)
if not valid_stream(stream_name, token):
raise ZulipEmailForwardError("Bad stream token from email recipient " + email)
return Stream.objects.get(email_token=token)
def find_emailgateway_recipient(message):
# We can't use Delivered-To; if there is a X-Gm-Original-To
# it is more accurate, so try to find the most-accurate
# recipient list in descending priority order
recipient_headers = ["X-Gm-Original-To", "Delivered-To", "To"]
recipients = []
for recipient_header in recipient_headers:
r = message.get_all(recipient_header, None)
if r:
recipients = r
break
pattern_parts = [re.escape(part) for part in settings.EMAIL_GATEWAY_PATTERN.split('%s')]
match_email_re = re.compile(".*?".join(pattern_parts))
for recipient_email in recipients:
if match_email_re.match(recipient_email):
return recipient_email
raise ZulipEmailForwardError("Missing recipient in mirror email")
def process_stream_message(to, subject, message, debug_info):
stream = extract_and_validate(to)
body = filter_footer(extract_body(message))
body += extract_and_upload_attachments(message, stream.realm)
debug_info["stream"] = stream
if not body:
# You can't send empty Zulips, so to avoid confusion over the
# email forwarding failing, set a dummy message body.
body = "(No email body)"
send_zulip(stream, subject, body)
def process_missed_message(to, message, pre_checked):
if not pre_checked:
mark_missed_message_address_as_used(to)
send_to_missed_message_address(to, message)
def process_message(message, rcpt_to=None, pre_checked=False):
subject = decode_header(message.get("Subject", "(no subject)"))[0][0]
debug_info = {}
try:
if rcpt_to is not None:
to = rcpt_to
else:
to = find_emailgateway_recipient(message)
debug_info["to"] = to
if is_missed_message_address(to):
process_missed_message(to, message, pre_checked)
else:
process_stream_message(to, subject, message, debug_info)
except ZulipEmailForwardError, e:
# TODO: notify sender of error, retry if appropriate.
log_and_report(message, e.message, debug_info)