de210260a7
As we make all configurations editable through dashboard(ex: password_reset_limit), it makes sense to provide limit as a callable so that it can be accessed dynamically.
125 lines
3.6 KiB
Python
125 lines
3.6 KiB
Python
# -*- coding: utf-8 -*-
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# Copyright (c) 2020, Frappe Technologies Pvt. Ltd. and Contributors
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# MIT License. See license.txt
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from __future__ import unicode_literals
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from datetime import datetime
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from functools import wraps
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from typing import Union, Callable
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from werkzeug.wrappers import Response
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import frappe
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from frappe import _
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from frappe.utils import cint
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def apply():
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rate_limit = frappe.conf.rate_limit
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if rate_limit:
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frappe.local.rate_limiter = RateLimiter(rate_limit["limit"], rate_limit["window"])
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frappe.local.rate_limiter.apply()
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def update():
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if hasattr(frappe.local, "rate_limiter"):
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frappe.local.rate_limiter.update()
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def respond():
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if hasattr(frappe.local, "rate_limiter"):
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return frappe.local.rate_limiter.respond()
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class RateLimiter:
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def __init__(self, limit, window):
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self.limit = int(limit * 1000000)
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self.window = window
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self.start = datetime.utcnow()
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timestamp = int(frappe.utils.now_datetime().timestamp())
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self.window_number, self.spent = divmod(timestamp, self.window)
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self.key = frappe.cache().make_key(f"rate-limit-counter-{self.window_number}")
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self.counter = cint(frappe.cache().get(self.key))
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self.remaining = max(self.limit - self.counter, 0)
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self.reset = self.window - self.spent
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self.end = None
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self.duration = None
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self.rejected = False
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def apply(self):
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if self.counter > self.limit:
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self.rejected = True
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self.reject()
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def reject(self):
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raise frappe.TooManyRequestsError
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def update(self):
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self.end = datetime.utcnow()
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self.duration = int((self.end - self.start).total_seconds() * 1000000)
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pipeline = frappe.cache().pipeline()
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pipeline.incrby(self.key, self.duration)
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pipeline.expire(self.key, self.window)
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pipeline.execute()
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def headers(self):
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headers = {
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"X-RateLimit-Reset": self.reset,
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"X-RateLimit-Limit": self.limit,
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"X-RateLimit-Remaining": self.remaining,
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}
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if self.rejected:
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headers["Retry-After"] = self.reset
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else:
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headers["X-RateLimit-Used"] = self.duration
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return headers
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def respond(self):
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if self.rejected:
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return Response(_("Too Many Requests"), status=429)
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def rate_limit(key: str, limit: Union[int, Callable] = 5, seconds: int= 24*60*60, methods: Union[str, list]='ALL'):
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"""Decorator to rate limit an endpoint.
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This will limit Number of requests per endpoint to `limit` within `seconds`.
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Uses redis cache to track request counts.
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:param key: Key is used to identify the requests uniqueness
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:param limit: Maximum number of requests to allow with in window time
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:type limit: Callable or Integer
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:param seconds: window time to allow requests
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:param methods: Limit the validation for these methods.
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`ALL` is a wildcard that applies rate limit on all methods.
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:type methods: string or list or tuple
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:returns: a decorator function that limit the number of requests per endpoint
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"""
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def ratelimit_decorator(fun):
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@wraps(fun)
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def wrapper(*args, **kwargs):
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# Do not apply rate limits if method is not opted to check
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if methods != 'ALL' and frappe.request.method.upper() not in methods:
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return frappe.call(fun, **frappe.form_dict)
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_limit = limit() if callable(limit) else limit
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identity = frappe.form_dict[key]
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cache_key = f"rl:{frappe.form_dict.cmd}:{identity}"
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value = frappe.cache().get_value(cache_key, expires=True) or 0
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if not value:
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frappe.cache().set_value(cache_key, 0, expires_in_sec=seconds)
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value = frappe.cache().incrby(cache_key, 1)
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if value > _limit:
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frappe.throw(_("You hit the rate limit because of too many requests. Please try after sometime."))
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return frappe.call(fun, **frappe.form_dict)
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return wrapper
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return ratelimit_decorator
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