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|
import logging
import time
import traceback
from urllib.parse import unquote
from twisted.internet.defer import inlineCallbacks, maybeDeferred
from twisted.internet.interfaces import IProtocolNegotiationFactory
from twisted.protocols.policies import ProtocolWrapper
from twisted.web import http
from zope.interface import implementer
from .utils import HEADER_NAME_RE, parse_x_forwarded_for
logger = logging.getLogger(__name__)
class WebRequest(http.Request):
"""
Request that either hands off information to channels, or offloads
to a WebSocket class.
Does some extra processing over the normal Twisted Web request to separate
GET and POST out.
"""
error_template = (
"""
<html>
<head>
<title>%(title)s</title>
<style>
body { font-family: sans-serif; margin: 0; padding: 0; }
h1 { padding: 0.6em 0 0.2em 20px; color: #896868; margin: 0; }
p { padding: 0 0 0.3em 20px; margin: 0; }
footer { padding: 1em 0 0.3em 20px; color: #999; font-size: 80%%; font-style: italic; }
</style>
</head>
<body>
<h1>%(title)s</h1>
<p>%(body)s</p>
<footer>Daphne</footer>
</body>
</html>
""".replace(
"\n", ""
)
.replace(" ", " ")
.replace(" ", " ")
.replace(" ", " ")
) # Shorten it a bit, bytes wise
def __init__(self, *args, **kwargs):
self.client_addr = None
self.server_addr = None
try:
http.Request.__init__(self, *args, **kwargs)
# Easy server link
self.server = self.channel.factory.server
self.application_queue = None
self._response_started = False
self.server.protocol_connected(self)
except Exception:
logger.error(traceback.format_exc())
raise
### Twisted progress callbacks
@inlineCallbacks
def process(self):
try:
self.request_start = time.time()
# Validate header names.
for name, _ in self.requestHeaders.getAllRawHeaders():
if not HEADER_NAME_RE.fullmatch(name):
self.basic_error(400, b"Bad Request", "Invalid header name")
return
# Get upgrade header
upgrade_header = None
if self.requestHeaders.hasHeader(b"Upgrade"):
upgrade_header = self.requestHeaders.getRawHeaders(b"Upgrade")[0]
# Get client address if possible
if hasattr(self.client, "host") and hasattr(self.client, "port"):
# client.host and host.host are byte strings in Python 2, but spec
# requires unicode string.
self.client_addr = [str(self.client.host), self.client.port]
self.server_addr = [str(self.host.host), self.host.port]
self.client_scheme = "https" if self.isSecure() else "http"
# See if we need to get the address from a proxy header instead
if self.server.proxy_forwarded_address_header:
self.client_addr, self.client_scheme = parse_x_forwarded_for(
self.requestHeaders,
self.server.proxy_forwarded_address_header,
self.server.proxy_forwarded_port_header,
self.server.proxy_forwarded_proto_header,
self.client_addr,
self.client_scheme,
)
# Check for unicodeish path (or it'll crash when trying to parse)
try:
self.path.decode("ascii")
except UnicodeDecodeError:
self.path = b"/"
self.basic_error(400, b"Bad Request", "Invalid characters in path")
return
# Calculate query string
self.query_string = b""
if b"?" in self.uri:
self.query_string = self.uri.split(b"?", 1)[1]
try:
self.query_string.decode("ascii")
except UnicodeDecodeError:
self.basic_error(400, b"Bad Request", "Invalid query string")
return
# Is it WebSocket? IS IT?!
if upgrade_header and upgrade_header.lower() == b"websocket":
# Make WebSocket protocol to hand off to
protocol = self.server.ws_factory.buildProtocol(
self.transport.getPeer()
)
if not protocol:
# If protocol creation fails, we signal "internal server error"
self.setResponseCode(500)
logger.warn("Could not make WebSocket protocol")
self.finish()
# Give it the raw query string
protocol._raw_query_string = self.query_string
# Port across transport
transport, self.transport = self.transport, None
if isinstance(transport, ProtocolWrapper):
# i.e. TLS is a wrapping protocol
transport.wrappedProtocol = protocol
else:
transport.protocol = protocol
protocol.makeConnection(transport)
# Re-inject request
data = self.method + b" " + self.uri + b" HTTP/1.1\x0d\x0a"
for h in self.requestHeaders.getAllRawHeaders():
data += h[0] + b": " + b",".join(h[1]) + b"\x0d\x0a"
data += b"\x0d\x0a"
data += self.content.read()
protocol.dataReceived(data)
# Remove our HTTP reply channel association
logger.debug("Upgraded connection %s to WebSocket", self.client_addr)
self.server.protocol_disconnected(self)
# Resume the producer so we keep getting data, if it's available as a method
self.channel._networkProducer.resumeProducing()
# Boring old HTTP.
else:
# Sanitize and decode headers, potentially extracting root path
self.clean_headers = []
self.root_path = self.server.root_path
for name, values in self.requestHeaders.getAllRawHeaders():
# Prevent CVE-2015-0219
if b"_" in name:
continue
for value in values:
if name.lower() == b"daphne-root-path":
self.root_path = unquote(value.decode("ascii"))
else:
self.clean_headers.append((name.lower(), value))
logger.debug("HTTP %s request for %s", self.method, self.client_addr)
self.content.seek(0, 0)
# Work out the application scope and create application
self.application_queue = yield maybeDeferred(
self.server.create_application,
self,
{
"type": "http",
# TODO: Correctly say if it's 1.1 or 1.0
"http_version": self.clientproto.split(b"/")[-1].decode(
"ascii"
),
"method": self.method.decode("ascii"),
"path": unquote(self.path.decode("ascii")),
"raw_path": self.path,
"root_path": self.root_path,
"scheme": self.client_scheme,
"query_string": self.query_string,
"headers": self.clean_headers,
"client": self.client_addr,
"server": self.server_addr,
},
)
# Check they didn't close an unfinished request
if self.application_queue is None or self.content.closed:
# Not much we can do, the request is prematurely abandoned.
return
# Run application against request
buffer_size = self.server.request_buffer_size
while True:
chunk = self.content.read(buffer_size)
more_body = not (len(chunk) < buffer_size)
payload = {
"type": "http.request",
"body": chunk,
"more_body": more_body,
}
self.application_queue.put_nowait(payload)
if not more_body:
break
except Exception:
logger.error(traceback.format_exc())
self.basic_error(
500, b"Internal Server Error", "Daphne HTTP processing error"
)
def connectionLost(self, reason):
"""
Cleans up reply channel on close.
"""
if self.application_queue:
self.send_disconnect()
logger.debug("HTTP disconnect for %s", self.client_addr)
http.Request.connectionLost(self, reason)
self.server.protocol_disconnected(self)
def finish(self):
"""
Cleans up reply channel on close.
"""
if self.application_queue:
self.send_disconnect()
logger.debug("HTTP close for %s", self.client_addr)
http.Request.finish(self)
self.server.protocol_disconnected(self)
### Server reply callbacks
def handle_reply(self, message):
"""
Handles a reply from the client
"""
# Handle connections that are already closed
if self.finished or self.channel is None:
return
# Check message validity
if "type" not in message:
raise ValueError("Message has no type defined")
# Handle message
if message["type"] == "http.response.start":
if self._response_started:
raise ValueError("HTTP response has already been started")
self._response_started = True
if "status" not in message:
raise ValueError(
"Specifying a status code is required for a Response message."
)
# Set HTTP status code
self.setResponseCode(message["status"])
# Write headers
for header, value in message.get("headers", {}):
self.responseHeaders.addRawHeader(header, value)
if self.server.server_name and not self.responseHeaders.hasHeader("server"):
self.setHeader(b"server", self.server.server_name.encode())
logger.debug(
"HTTP %s response started for %s", message["status"], self.client_addr
)
elif message["type"] == "http.response.body":
if not self._response_started:
raise ValueError(
"HTTP response has not yet been started but got %s"
% message["type"]
)
# Write out body
http.Request.write(self, message.get("body", b""))
# End if there's no more content
if not message.get("more_body", False):
self.finish()
logger.debug("HTTP response complete for %s", self.client_addr)
try:
uri = self.uri.decode("ascii")
except UnicodeDecodeError:
# The path is malformed somehow - do our best to log something
uri = repr(self.uri)
try:
self.server.log_action(
"http",
"complete",
{
"path": uri,
"status": self.code,
"method": self.method.decode("ascii", "replace"),
"client": (
"%s:%s" % tuple(self.client_addr)
if self.client_addr
else None
),
"time_taken": self.duration(),
"size": self.sentLength,
},
)
except Exception:
logger.error(traceback.format_exc())
else:
logger.debug("HTTP response chunk for %s", self.client_addr)
else:
raise ValueError("Cannot handle message type %s!" % message["type"])
def handle_exception(self, exception):
"""
Called by the server when our application tracebacks
"""
self.basic_error(500, b"Internal Server Error", "Exception inside application.")
def check_timeouts(self):
"""
Called periodically to see if we should timeout something
"""
# Web timeout checking
if self.server.http_timeout and self.duration() > self.server.http_timeout:
if self._response_started:
logger.warning("Application timed out while sending response")
self.finish()
else:
self.basic_error(
503,
b"Service Unavailable",
"Application failed to respond within time limit.",
)
### Utility functions
def send_disconnect(self):
"""
Sends a http.disconnect message.
Useful only really for long-polling.
"""
# If we don't yet have a path, then don't send as we never opened.
if self.path:
self.application_queue.put_nowait({"type": "http.disconnect"})
def duration(self):
"""
Returns the time since the start of the request.
"""
if not hasattr(self, "request_start"):
return 0
return time.time() - self.request_start
def basic_error(self, status, status_text, body):
"""
Responds with a server-level error page (very basic)
"""
self.handle_reply(
{
"type": "http.response.start",
"status": status,
"headers": [(b"Content-Type", b"text/html; charset=utf-8")],
}
)
self.handle_reply(
{
"type": "http.response.body",
"body": (
self.error_template
% {
"title": str(status) + " " + status_text.decode("ascii"),
"body": body,
}
).encode("utf8"),
}
)
def __hash__(self):
return hash(id(self))
def __eq__(self, other):
return id(self) == id(other)
@implementer(IProtocolNegotiationFactory)
class HTTPFactory(http.HTTPFactory):
"""
Factory which takes care of tracking which protocol
instances or request instances are responsible for which
named response channels, so incoming messages can be
routed appropriately.
"""
def __init__(self, server):
http.HTTPFactory.__init__(self)
self.server = server
def buildProtocol(self, addr):
"""
Builds protocol instances. This override is used to ensure we use our
own Request object instead of the default.
"""
try:
protocol = http.HTTPFactory.buildProtocol(self, addr)
protocol.requestFactory = WebRequest
return protocol
except Exception:
logger.error("Cannot build protocol: %s" % traceback.format_exc())
raise
# IProtocolNegotiationFactory
def acceptableProtocols(self):
"""
Protocols this server can speak after ALPN negotiation. Currently that
is HTTP/1.1 and optionally HTTP/2. Websockets cannot be negotiated
using ALPN, so that doesn't go here: anyone wanting websockets will
negotiate HTTP/1.1 and then do the upgrade dance.
"""
baseProtocols = [b"http/1.1"]
if http.H2_ENABLED:
baseProtocols.insert(0, b"h2")
return baseProtocols
|
