from __future__ import annotations import abc import copy import enum import functools import io import typing import urllib.parse import urllib.request import urllib.response from collections.abc import Iterable, Mapping from email.message import Message from http import HTTPStatus from http.cookiejar import CookieJar from ._helper import make_ssl_context, wrap_request_errors from .exceptions import ( NoSupportingHandlers, RequestError, TransportError, UnsupportedRequest, ) from ..utils import ( bug_reports_message, classproperty, deprecation_warning, error_to_str, escape_url, update_url_query, ) from ..utils.networking import HTTPHeaderDict if typing.TYPE_CHECKING: RequestData = bytes | Iterable[bytes] | typing.IO | None class RequestDirector: """RequestDirector class Helper class that, when given a request, forward it to a RequestHandler that supports it. @param logger: Logger instance. @param verbose: Print debug request information to stdout. """ def __init__(self, logger, verbose=False): self.handlers: dict[str, RequestHandler] = {} self.logger = logger # TODO(Grub4k): default logger self.verbose = verbose def close(self): for handler in self.handlers.values(): handler.close() def add_handler(self, handler: RequestHandler): """Add a handler. If a handler of the same RH_KEY exists, it will overwrite it""" assert isinstance(handler, RequestHandler), 'handler must be a RequestHandler' self.handlers[handler.RH_KEY] = handler def _print_verbose(self, msg): if self.verbose: self.logger.stdout(f'director: {msg}') def send(self, request: Request) -> Response: """ Passes a request onto a suitable RequestHandler """ if not self.handlers: raise RequestError('No request handlers configured') assert isinstance(request, Request) unexpected_errors = [] unsupported_errors = [] # TODO (future): add a per-request preference system for handler in reversed(list(self.handlers.values())): self._print_verbose(f'Checking if "{handler.RH_NAME}" supports this request.') try: handler.validate(request) except UnsupportedRequest as e: self._print_verbose( f'"{handler.RH_NAME}" cannot handle this request (reason: {error_to_str(e)})') unsupported_errors.append(e) continue self._print_verbose(f'Sending request via "{handler.RH_NAME}"') try: response = handler.send(request) except RequestError: raise except Exception as e: self.logger.error( f'[{handler.RH_NAME}] Unexpected error: {error_to_str(e)}{bug_reports_message()}', is_error=False) unexpected_errors.append(e) continue assert isinstance(response, Response) return response raise NoSupportingHandlers(unsupported_errors, unexpected_errors) _REQUEST_HANDLERS = {} def register(handler): """Register a RequestHandler class""" assert issubclass(handler, RequestHandler), f'{handler} must be a subclass of RequestHandler' assert handler.RH_KEY not in _REQUEST_HANDLERS, f'RequestHandler {handler.RH_KEY} already registered' _REQUEST_HANDLERS[handler.RH_KEY] = handler return handler class Features(enum.Enum): ALL_PROXY = enum.auto() NO_PROXY = enum.auto() class RequestHandler(abc.ABC): """Request Handler class Request handlers are class that, given a Request, process the request from start to finish and return a Response. Concrete subclasses need to redefine the _send(request) method, which handles the underlying request logic and returns a Response. RH_NAME class variable may contain a display name for the RequestHandler. By default, this is generated from the class name. The concrete request handler MUST have "RH" as the suffix in the class name. All exceptions raised by a RequestHandler should be an instance of RequestError. Any other exception raised will be treated as a handler issue. If a Request is not supported by the handler, an UnsupportedRequest should be raised with a reason. By default, some checks are done on the request in _validate() based on the following class variables: - `_SUPPORTED_URL_SCHEMES`: a tuple of supported url schemes. Any Request with an url scheme not in this list will raise an UnsupportedRequest. - `_SUPPORTED_PROXY_SCHEMES`: a tuple of support proxy url schemes. Any Request that contains a proxy url with an url scheme not in this list will raise an UnsupportedRequest. - `_SUPPORTED_FEATURES`: a tuple of supported features, as defined in Features enum. The above may be set to None to disable the checks. Parameters: @param logger: logger instance @param headers: HTTP Headers to include when sending requests. @param cookiejar: Cookiejar to use for requests. @param timeout: Socket timeout to use when sending requests. @param proxies: Proxies to use for sending requests. @param source_address: Client-side IP address to bind to for requests. @param verbose: Print debug request and traffic information to stdout. @param prefer_system_certs: Whether to prefer system certificates over other means (e.g. certifi). @param client_cert: SSL client certificate configuration. dict with {client_certificate, client_certificate_key, client_certificate_password} @param verify: Verify SSL certificates @param legacy_ssl_support: Enable legacy SSL options such as legacy server connect and older cipher support. Some configuration options may be available for individual Requests too. In this case, either the Request configuration option takes precedence or they are merged. Requests may have additional optional parameters defined as extensions. RequestHandler subclasses may choose to support custom extensions. The following extensions are defined for RequestHandler: - `cookiejar`: Cookiejar to use for this request - `timeout`: socket timeout to use for this request Apart from the url protocol, proxies dict may contain the following keys: - `all`: proxy to use for all protocols. Used as a fallback if no proxy is set for a specific protocol. - `no`: comma seperated list of hostnames (optionally with port) to not use a proxy for. Note: a RequestHandler may not support these, as defined in `_SUPPORTED_FEATURES`. """ _SUPPORTED_URL_SCHEMES = () _SUPPORTED_PROXY_SCHEMES = () _SUPPORTED_FEATURES = () def __init__( self, *, logger, # TODO(Grub4k): default logger headers: HTTPHeaderDict = None, cookiejar: CookieJar = None, timeout: float | int | None = None, proxies: dict = None, source_address: str = None, verbose: bool = False, prefer_system_certs: bool = False, client_cert: dict[str, str | None] = None, verify: bool = True, legacy_ssl_support: bool = False, **_, ): self._logger = logger self.headers = headers or {} self.cookiejar = cookiejar if cookiejar is not None else CookieJar() self.timeout = float(timeout or 20) self.proxies = proxies or {} self.source_address = source_address self.verbose = verbose self.prefer_system_certs = prefer_system_certs self._client_cert = client_cert or {} self.verify = verify self.legacy_ssl_support = legacy_ssl_support super().__init__() def _make_sslcontext(self): return make_ssl_context( verify=self.verify, legacy_support=self.legacy_ssl_support, use_certifi=not self.prefer_system_certs, **self._client_cert, ) def _merge_headers(self, request_headers): return HTTPHeaderDict(self.headers, request_headers) def _check_url_scheme(self, request: Request): scheme = urllib.parse.urlparse(request.url).scheme.lower() if self._SUPPORTED_URL_SCHEMES is not None and scheme not in self._SUPPORTED_URL_SCHEMES: raise UnsupportedRequest(f'Unsupported url scheme: "{scheme}"') return scheme # for further processing def _check_proxies(self, proxies): for proxy_key, proxy_url in proxies.items(): if proxy_url is None: continue if proxy_key == 'no': if self._SUPPORTED_FEATURES is not None and Features.NO_PROXY not in self._SUPPORTED_FEATURES: raise UnsupportedRequest('"no" proxy is not supported') continue if ( proxy_key == 'all' and self._SUPPORTED_FEATURES is not None and Features.ALL_PROXY not in self._SUPPORTED_FEATURES ): raise UnsupportedRequest('"all" proxy is not supported') # Unlikely this handler will use this proxy, so ignore. # This is to allow a case where a proxy may be set for a protocol # for one handler in which such protocol (and proxy) is not supported by another handler. if self._SUPPORTED_URL_SCHEMES is not None and proxy_key not in (*self._SUPPORTED_URL_SCHEMES, 'all'): continue if self._SUPPORTED_PROXY_SCHEMES is None: # Skip proxy scheme checks continue # Scheme-less proxies are not supported if urllib.request._parse_proxy(proxy_url)[0] is None: raise UnsupportedRequest(f'Proxy "{proxy_url}" missing scheme') scheme = urllib.parse.urlparse(proxy_url).scheme.lower() if scheme not in self._SUPPORTED_PROXY_SCHEMES: raise UnsupportedRequest(f'Unsupported proxy type: "{scheme}"') def _check_cookiejar_extension(self, extensions): if not extensions.get('cookiejar'): return if not isinstance(extensions['cookiejar'], CookieJar): raise UnsupportedRequest('cookiejar is not a CookieJar') def _check_timeout_extension(self, extensions): if extensions.get('timeout') is None: return if not isinstance(extensions['timeout'], (float, int)): raise UnsupportedRequest('timeout is not a float or int') def _check_extensions(self, extensions): self._check_cookiejar_extension(extensions) self._check_timeout_extension(extensions) def _validate(self, request): self._check_url_scheme(request) self._check_proxies(request.proxies or self.proxies) self._check_extensions(request.extensions) @wrap_request_errors def validate(self, request: Request): if not isinstance(request, Request): raise TypeError('Expected an instance of Request') self._validate(request) @wrap_request_errors def send(self, request: Request) -> Response: if not isinstance(request, Request): raise TypeError('Expected an instance of Request') return self._send(request) @abc.abstractmethod def _send(self, request: Request): """Handle a request from start to finish. Redefine in subclasses.""" def close(self): pass @classproperty def RH_NAME(cls): return cls.__name__[:-2] @classproperty def RH_KEY(cls): assert cls.__name__.endswith('RH'), 'RequestHandler class names must end with "RH"' return cls.__name__[:-2] def __enter__(self): return self def __exit__(self, *args): self.close() class Request: """ Represents a request to be made. Partially backwards-compatible with urllib.request.Request. @param url: url to send. Will be sanitized. @param data: payload data to send. Must be bytes, iterable of bytes, a file-like object or None @param headers: headers to send. @param proxies: proxy dict mapping of proto:proxy to use for the request and any redirects. @param query: URL query parameters to update the url with. @param method: HTTP method to use. If no method specified, will use POST if payload data is present else GET @param extensions: Dictionary of Request extensions to add, as supported by handlers. """ def __init__( self, url: str, data: RequestData = None, headers: typing.Mapping = None, proxies: dict = None, query: dict = None, method: str = None, extensions: dict = None ): self._headers = HTTPHeaderDict() self._data = None if query: url = update_url_query(url, query) self.url = url self.method = method if headers: self.headers = headers self.data = data # note: must be done after setting headers self.proxies = proxies or {} self.extensions = extensions or {} @property def url(self): return self._url @url.setter def url(self, url): if not isinstance(url, str): raise TypeError('url must be a string') elif url.startswith('//'): url = 'http:' + url self._url = escape_url(url) @property def method(self): return self._method or ('POST' if self.data is not None else 'GET') @method.setter def method(self, method): if method is None: self._method = None elif isinstance(method, str): self._method = method.upper() else: raise TypeError('method must be a string') @property def data(self): return self._data @data.setter def data(self, data: RequestData): # Try catch some common mistakes if data is not None and ( not isinstance(data, (bytes, io.IOBase, Iterable)) or isinstance(data, (str, Mapping)) ): raise TypeError('data must be bytes, iterable of bytes, or a file-like object') if data == self._data and self._data is None: self.headers.pop('Content-Length', None) # https://docs.python.org/3/library/urllib.request.html#urllib.request.Request.data if data != self._data: if self._data is not None: self.headers.pop('Content-Length', None) self._data = data if self._data is None: self.headers.pop('Content-Type', None) if 'Content-Type' not in self.headers and self._data is not None: self.headers['Content-Type'] = 'application/x-www-form-urlencoded' @property def headers(self) -> HTTPHeaderDict: return self._headers @headers.setter def headers(self, new_headers: Mapping): """Replaces headers of the request. If not a CaseInsensitiveDict, it will be converted to one.""" if isinstance(new_headers, HTTPHeaderDict): self._headers = new_headers elif isinstance(new_headers, Mapping): self._headers = HTTPHeaderDict(new_headers) else: raise TypeError('headers must be a mapping') def update(self, url=None, data=None, headers=None, query=None): self.data = data or self.data self.headers.update(headers or {}) self.url = update_url_query(url or self.url, query or {}) def copy(self): return self.__class__( url=self.url, headers=copy.deepcopy(self.headers), proxies=copy.deepcopy(self.proxies), data=self._data, extensions=copy.copy(self.extensions), method=self._method, ) HEADRequest = functools.partial(Request, method='HEAD') PUTRequest = functools.partial(Request, method='PUT') class Response(io.IOBase): """ Base class for HTTP response adapters. By default, it provides a basic wrapper for a file-like response object. Interface partially backwards-compatible with addinfourl and http.client.HTTPResponse. @param fp: Original, file-like, response. @param url: URL that this is a response of. @param headers: response headers. @param status: Response HTTP status code. Default is 200 OK. @param reason: HTTP status reason. Will use built-in reasons based on status code if not provided. """ def __init__( self, fp: typing.IO, url: str, headers: Mapping[str, str], status: int = 200, reason: str = None): self.fp = fp self.headers = Message() for name, value in headers.items(): self.headers.add_header(name, value) self.status = status self.url = url try: self.reason = reason or HTTPStatus(status).phrase except ValueError: self.reason = None def readable(self): return self.fp.readable() def read(self, amt: int = None) -> bytes: # Expected errors raised here should be of type RequestError or subclasses. # Subclasses should redefine this method with more precise error handling. try: return self.fp.read(amt) except Exception as e: raise TransportError(cause=e) from e def close(self): self.fp.close() return super().close() def get_header(self, name, default=None): """Get header for name. If there are multiple matching headers, return all seperated by comma.""" headers = self.headers.get_all(name) if not headers: return default if name.title() == 'Set-Cookie': # Special case, only get the first one # https://www.rfc-editor.org/rfc/rfc9110.html#section-5.3-4.1 return headers[0] return ', '.join(headers) # The following methods are for compatability reasons and are deprecated @property def code(self): deprecation_warning('Response.code is deprecated, use Response.status', stacklevel=2) return self.status def getcode(self): deprecation_warning('Response.getcode() is deprecated, use Response.status', stacklevel=2) return self.status def geturl(self): deprecation_warning('Response.geturl() is deprecated, use Response.url', stacklevel=2) return self.url def info(self): deprecation_warning('Response.info() is deprecated, use Response.headers', stacklevel=2) return self.headers def getheader(self, name, default=None): deprecation_warning('Response.getheader() is deprecated, use Response.get_header', stacklevel=2) return self.get_header(name, default)