Files
paperless-ngx/src/documents/workflows/webhooks.py

139 lines
3.8 KiB
Python

import logging
import httpx
from celery import shared_task
from django.conf import settings
from paperless.network import format_host_for_url
from paperless.network import is_public_ip
from paperless.network import resolve_hostname_ips
from paperless.network import validate_outbound_http_url
logger = logging.getLogger("paperless.workflows.webhooks")
class WebhookTransport(httpx.HTTPTransport):
"""
Transport that resolves/validates hostnames and rewrites to a vetted IP
while keeping Host/SNI as the original hostname.
"""
def __init__(
self,
hostname: str,
*args,
allow_internal: bool = False,
**kwargs,
) -> None:
super().__init__(*args, **kwargs)
self.hostname = hostname
self.allow_internal = allow_internal
def handle_request(self, request: httpx.Request) -> httpx.Response:
hostname = request.url.host
if not hostname:
raise httpx.ConnectError("No hostname in request URL")
try:
ips = resolve_hostname_ips(hostname)
except ValueError as e:
raise httpx.ConnectError(str(e)) from e
if not self.allow_internal:
for ip_str in ips:
if not is_public_ip(ip_str):
raise httpx.ConnectError(
f"Connection blocked: {hostname} resolves to a non-public address",
)
ip_str = ips[0]
formatted_ip = format_host_for_url(ip_str)
new_headers = httpx.Headers(request.headers)
if "host" in new_headers:
del new_headers["host"]
new_headers["Host"] = hostname
new_url = request.url.copy_with(host=formatted_ip)
request = httpx.Request(
method=request.method,
url=new_url,
headers=new_headers,
content=request.stream,
extensions=request.extensions,
)
request.extensions["sni_hostname"] = hostname
return super().handle_request(request)
@shared_task(
retry_backoff=True,
autoretry_for=(httpx.HTTPStatusError,),
max_retries=3,
throws=(httpx.HTTPError,),
)
def send_webhook(
url: str,
data: str | dict,
headers: dict,
files: dict,
*,
as_json: bool = False,
):
try:
parsed = validate_outbound_http_url(
url,
allowed_schemes=settings.WEBHOOKS_ALLOWED_SCHEMES,
allowed_ports=settings.WEBHOOKS_ALLOWED_PORTS,
# Internal-address checks happen in transport to preserve ConnectError behavior.
allow_internal=True,
)
except ValueError as e:
logger.warning("Webhook blocked: %s", e)
raise
hostname = parsed.hostname
if hostname is None: # pragma: no cover
raise ValueError("Invalid URL scheme or hostname.")
transport = WebhookTransport(
hostname=hostname,
allow_internal=settings.WEBHOOKS_ALLOW_INTERNAL_REQUESTS,
)
try:
post_args = {
"url": url,
"headers": {
k: v for k, v in (headers or {}).items() if k.lower() != "host"
},
"files": files or None,
}
if as_json:
post_args["json"] = data
elif isinstance(data, dict):
post_args["data"] = data
else:
post_args["content"] = data
with httpx.Client(
transport=transport,
timeout=5.0,
follow_redirects=False,
) as client:
client.post(
**post_args,
).raise_for_status()
logger.info(
f"Webhook sent to {url}",
)
except Exception as e:
logger.error(
f"Failed attempt sending webhook to {url}: {e}",
)
raise e
finally:
transport.close()