import cProfile import logging import time import traceback from typing import Any, AnyStr, Dict, \ Iterable, List, MutableMapping, Optional from django.conf import settings from django.contrib.sessions.backends.base import UpdateError from django.contrib.sessions.middleware import SessionMiddleware from django.core.exceptions import DisallowedHost, SuspiciousOperation from django.db import connection from django.http import HttpRequest, HttpResponse, StreamingHttpResponse from django.middleware.common import CommonMiddleware from django.shortcuts import render from django.utils.cache import patch_vary_headers from django.utils.deprecation import MiddlewareMixin from django.utils.http import http_date from django.utils.translation import ugettext as _ from django.views.csrf import csrf_failure as html_csrf_failure from zerver.lib.bugdown import get_bugdown_requests, get_bugdown_time from zerver.lib.cache import get_remote_cache_requests, get_remote_cache_time from zerver.lib.debug import maybe_tracemalloc_listen from zerver.lib.db import reset_queries from zerver.lib.exceptions import ErrorCode, JsonableError, RateLimited from zerver.lib.html_to_text import get_content_description from zerver.lib.queue import queue_json_publish from zerver.lib.rate_limiter import RateLimitResult, max_api_calls from zerver.lib.response import json_error, json_response_from_error from zerver.lib.subdomains import get_subdomain from zerver.lib.utils import statsd from zerver.lib.types import ViewFuncT from zerver.models import Realm, flush_per_request_caches, get_realm logger = logging.getLogger('zulip.requests') def record_request_stop_data(log_data: MutableMapping[str, Any]) -> None: log_data['time_stopped'] = time.time() log_data['remote_cache_time_stopped'] = get_remote_cache_time() log_data['remote_cache_requests_stopped'] = get_remote_cache_requests() log_data['bugdown_time_stopped'] = get_bugdown_time() log_data['bugdown_requests_stopped'] = get_bugdown_requests() if settings.PROFILE_ALL_REQUESTS: log_data["prof"].disable() def async_request_timer_stop(request: HttpRequest) -> None: record_request_stop_data(request._log_data) def record_request_restart_data(log_data: MutableMapping[str, Any]) -> None: if settings.PROFILE_ALL_REQUESTS: log_data["prof"].enable() log_data['time_restarted'] = time.time() log_data['remote_cache_time_restarted'] = get_remote_cache_time() log_data['remote_cache_requests_restarted'] = get_remote_cache_requests() log_data['bugdown_time_restarted'] = get_bugdown_time() log_data['bugdown_requests_restarted'] = get_bugdown_requests() def async_request_timer_restart(request: HttpRequest) -> None: if "time_restarted" in request._log_data: # Don't destroy data when being called from # finish_current_handler return record_request_restart_data(request._log_data) def record_request_start_data(log_data: MutableMapping[str, Any]) -> None: if settings.PROFILE_ALL_REQUESTS: log_data["prof"] = cProfile.Profile() log_data["prof"].enable() reset_queries() log_data['time_started'] = time.time() log_data['remote_cache_time_start'] = get_remote_cache_time() log_data['remote_cache_requests_start'] = get_remote_cache_requests() log_data['bugdown_time_start'] = get_bugdown_time() log_data['bugdown_requests_start'] = get_bugdown_requests() def timedelta_ms(timedelta: float) -> float: return timedelta * 1000 def format_timedelta(timedelta: float) -> str: if (timedelta >= 1): return "%.1fs" % (timedelta,) return "%.0fms" % (timedelta_ms(timedelta),) def is_slow_query(time_delta: float, path: str) -> bool: if time_delta < 1.2: return False is_exempt = \ path in ["/activity", "/json/report/error", "/api/v1/deployments/report_error"] \ or path.startswith("/realm_activity/") \ or path.startswith("/user_activity/") if is_exempt: return time_delta >= 5 if 'webathena_kerberos' in path: return time_delta >= 10 return True statsd_blacklisted_requests = [ 'do_confirm', 'signup_send_confirm', 'new_realm_send_confirm,' 'eventslast_event_id', 'webreq.content', 'avatar', 'user_uploads', 'password.reset', 'static', 'json.bots', 'json.users', 'json.streams', 'accounts.unsubscribe', 'apple-touch-icon', 'emoji', 'json.bots', 'upload_file', 'realm_activity', 'user_activity' ] def write_log_line(log_data: MutableMapping[str, Any], path: str, method: str, remote_ip: str, requestor_for_logs: str, client_name: str, status_code: int=200, error_content: Optional[AnyStr]=None, error_content_iter: Optional[Iterable[AnyStr]]=None) -> None: assert error_content is None or error_content_iter is None if error_content is not None: error_content_iter = (error_content,) if settings.STATSD_HOST != '': # For statsd timer name if path == '/': statsd_path = u'webreq' else: statsd_path = u"webreq.%s" % (path[1:].replace('/', '.'),) # Remove non-ascii chars from path (there should be none, if there are it's # because someone manually entered a nonexistent path), as UTF-8 chars make # statsd sad when it sends the key name over the socket statsd_path = statsd_path.encode('ascii', errors='ignore').decode("ascii") # TODO: This could probably be optimized to use a regular expression rather than a loop. suppress_statsd = any((blacklisted in statsd_path for blacklisted in statsd_blacklisted_requests)) else: suppress_statsd = True statsd_path = '' time_delta = -1 # A time duration of -1 means the StartLogRequests middleware # didn't run for some reason optional_orig_delta = "" if 'time_started' in log_data: time_delta = time.time() - log_data['time_started'] if 'time_stopped' in log_data: orig_time_delta = time_delta time_delta = ((log_data['time_stopped'] - log_data['time_started']) + (time.time() - log_data['time_restarted'])) optional_orig_delta = " (lp: %s)" % (format_timedelta(orig_time_delta),) remote_cache_output = "" if 'remote_cache_time_start' in log_data: remote_cache_time_delta = get_remote_cache_time() - log_data['remote_cache_time_start'] remote_cache_count_delta = get_remote_cache_requests() - log_data['remote_cache_requests_start'] if 'remote_cache_requests_stopped' in log_data: # (now - restarted) + (stopped - start) = (now - start) + (stopped - restarted) remote_cache_time_delta += (log_data['remote_cache_time_stopped'] - log_data['remote_cache_time_restarted']) remote_cache_count_delta += (log_data['remote_cache_requests_stopped'] - log_data['remote_cache_requests_restarted']) if (remote_cache_time_delta > 0.005): remote_cache_output = " (mem: %s/%s)" % (format_timedelta(remote_cache_time_delta), remote_cache_count_delta) if not suppress_statsd: statsd.timing("%s.remote_cache.time" % (statsd_path,), timedelta_ms(remote_cache_time_delta)) statsd.incr("%s.remote_cache.querycount" % (statsd_path,), remote_cache_count_delta) startup_output = "" if 'startup_time_delta' in log_data and log_data["startup_time_delta"] > 0.005: startup_output = " (+start: %s)" % (format_timedelta(log_data["startup_time_delta"]),) bugdown_output = "" if 'bugdown_time_start' in log_data: bugdown_time_delta = get_bugdown_time() - log_data['bugdown_time_start'] bugdown_count_delta = get_bugdown_requests() - log_data['bugdown_requests_start'] if 'bugdown_requests_stopped' in log_data: # (now - restarted) + (stopped - start) = (now - start) + (stopped - restarted) bugdown_time_delta += (log_data['bugdown_time_stopped'] - log_data['bugdown_time_restarted']) bugdown_count_delta += (log_data['bugdown_requests_stopped'] - log_data['bugdown_requests_restarted']) if (bugdown_time_delta > 0.005): bugdown_output = " (md: %s/%s)" % (format_timedelta(bugdown_time_delta), bugdown_count_delta) if not suppress_statsd: statsd.timing("%s.markdown.time" % (statsd_path,), timedelta_ms(bugdown_time_delta)) statsd.incr("%s.markdown.count" % (statsd_path,), bugdown_count_delta) # Get the amount of time spent doing database queries db_time_output = "" queries = connection.connection.queries if connection.connection is not None else [] if len(queries) > 0: query_time = sum(float(query.get('time', 0)) for query in queries) db_time_output = " (db: %s/%sq)" % (format_timedelta(query_time), len(queries)) if not suppress_statsd: # Log ms, db ms, and num queries to statsd statsd.timing("%s.dbtime" % (statsd_path,), timedelta_ms(query_time)) statsd.incr("%s.dbq" % (statsd_path,), len(queries)) statsd.timing("%s.total" % (statsd_path,), timedelta_ms(time_delta)) if 'extra' in log_data: extra_request_data = " %s" % (log_data['extra'],) else: extra_request_data = "" logger_client = "(%s via %s)" % (requestor_for_logs, client_name) logger_timing = ('%5s%s%s%s%s%s %s' % (format_timedelta(time_delta), optional_orig_delta, remote_cache_output, bugdown_output, db_time_output, startup_output, path)) logger_line = ('%-15s %-7s %3d %s%s %s' % (remote_ip, method, status_code, logger_timing, extra_request_data, logger_client)) if (status_code in [200, 304] and method == "GET" and path.startswith("/static")): logger.debug(logger_line) else: logger.info(logger_line) if (is_slow_query(time_delta, path)): queue_json_publish("slow_queries", dict( query="%s (%s)" % (logger_line, requestor_for_logs))) if settings.PROFILE_ALL_REQUESTS: log_data["prof"].disable() profile_path = "/tmp/profile.data.%s.%s" % (path.split("/")[-1], int(time_delta * 1000),) log_data["prof"].dump_stats(profile_path) # Log some additional data whenever we return certain 40x errors if 400 <= status_code < 500 and status_code not in [401, 404, 405]: assert error_content_iter is not None error_content_list = list(error_content_iter) if not error_content_list: error_data = u'' elif isinstance(error_content_list[0], str): error_data = u''.join(error_content_list) elif isinstance(error_content_list[0], bytes): error_data = repr(b''.join(error_content_list)) if len(error_data) > 200: error_data = u"[content more than 200 characters]" logger.info('status=%3d, data=%s, uid=%s' % (status_code, error_data, requestor_for_logs)) class LogRequests(MiddlewareMixin): # We primarily are doing logging using the process_view hook, but # for some views, process_view isn't run, so we call the start # method here too def process_request(self, request: HttpRequest) -> None: maybe_tracemalloc_listen() if hasattr(request, "_log_data"): # Sanity check to ensure this is being called from the # Tornado code path that returns responses asynchronously. assert getattr(request, "saved_response", False) # Avoid re-initializing request._log_data if it's already there. return request._log_data = dict() record_request_start_data(request._log_data) def process_view(self, request: HttpRequest, view_func: ViewFuncT, args: List[str], kwargs: Dict[str, Any]) -> None: if hasattr(request, "saved_response"): # The below logging adjustments are unnecessary (because # we've already imported everything) and incorrect # (because they'll overwrite data from pre-long-poll # request processing) when returning a saved response. return # process_request was already run; we save the initialization # time (i.e. the time between receiving the request and # figuring out which view function to call, which is primarily # importing modules on the first start) request._log_data["startup_time_delta"] = time.time() - request._log_data["time_started"] # And then completely reset our tracking to only cover work # done as part of this request record_request_start_data(request._log_data) def process_response(self, request: HttpRequest, response: StreamingHttpResponse) -> StreamingHttpResponse: if getattr(response, "asynchronous", False): # This special Tornado "asynchronous" response is # discarded after going through this code path as Tornado # intends to block, so we stop here to avoid unnecessary work. return response # The reverse proxy might have sent us the real external IP remote_ip = request.META.get('HTTP_X_REAL_IP') if remote_ip is None: remote_ip = request.META['REMOTE_ADDR'] # Get the requestor's identifier and client, if available. try: requestor_for_logs = request._requestor_for_logs except Exception: requestor_for_logs = "unauth" try: client = request.client.name except Exception: client = "?" if response.streaming: content_iter = response.streaming_content content = None else: content = response.content content_iter = None write_log_line(request._log_data, request.path, request.method, remote_ip, requestor_for_logs, client, status_code=response.status_code, error_content=content, error_content_iter=content_iter) return response class JsonErrorHandler(MiddlewareMixin): def process_exception(self, request: HttpRequest, exception: Exception) -> Optional[HttpResponse]: if isinstance(exception, JsonableError): return json_response_from_error(exception) if request.error_format == "JSON": logging.error(traceback.format_exc(), extra=dict(request=request)) return json_error(_("Internal server error"), status=500) return None class TagRequests(MiddlewareMixin): def process_view(self, request: HttpRequest, view_func: ViewFuncT, args: List[str], kwargs: Dict[str, Any]) -> None: self.process_request(request) def process_request(self, request: HttpRequest) -> None: if request.path.startswith("/api/") or request.path.startswith("/json/"): request.error_format = "JSON" else: request.error_format = "HTML" class CsrfFailureError(JsonableError): http_status_code = 403 code = ErrorCode.CSRF_FAILED data_fields = ['reason'] def __init__(self, reason: str) -> None: self.reason = reason # type: str @staticmethod def msg_format() -> str: return _("CSRF Error: {reason}") def csrf_failure(request: HttpRequest, reason: str="") -> HttpResponse: if request.error_format == "JSON": return json_response_from_error(CsrfFailureError(reason)) else: return html_csrf_failure(request, reason) class RateLimitMiddleware(MiddlewareMixin): def set_response_headers(self, response: HttpResponse, rate_limit_results: List[RateLimitResult]) -> None: # The limit on the action that was requested is the minimum of the limits that get applied: limit = min([max_api_calls(result.entity) for result in rate_limit_results]) response['X-RateLimit-Limit'] = str(limit) # Same principle applies to remaining api calls: if all(result.remaining for result in rate_limit_results): remaining_api_calls = min([result.remaining for result in rate_limit_results]) response['X-RateLimit-Remaining'] = str(remaining_api_calls) else: response['X-RateLimit-Remaining'] = str(0) # The full reset time is the maximum of the reset times for the limits that get applied: reset_time = time.time() + max([result.secs_to_freedom for result in rate_limit_results]) response['X-RateLimit-Reset'] = str(int(reset_time)) def process_response(self, request: HttpRequest, response: HttpResponse) -> HttpResponse: if not settings.RATE_LIMITING: return response # Add X-RateLimit-*** headers if hasattr(request, '_ratelimit'): rate_limit_results = list(request._ratelimit.values()) self.set_response_headers(response, rate_limit_results) return response def process_exception(self, request: HttpRequest, exception: Exception) -> Optional[HttpResponse]: if isinstance(exception, RateLimited): entity_type = str(exception) # entity type is passed to RateLimited when raising resp = json_error( _("API usage exceeded rate limit"), data={'retry-after': request._ratelimit[entity_type].secs_to_freedom}, status=429 ) resp['Retry-After'] = request._ratelimit[entity_type].secs_to_freedom return resp return None class FlushDisplayRecipientCache(MiddlewareMixin): def process_response(self, request: HttpRequest, response: HttpResponse) -> HttpResponse: # We flush the per-request caches after every request, so they # are not shared at all between requests. flush_per_request_caches() return response class SessionHostDomainMiddleware(SessionMiddleware): def process_response(self, request: HttpRequest, response: HttpResponse) -> HttpResponse: if getattr(response, "asynchronous", False): # This special Tornado "asynchronous" response is # discarded after going through this code path as Tornado # intends to block, so we stop here to avoid unnecessary work. return response try: request.get_host() except DisallowedHost: # If we get a DisallowedHost exception trying to access # the host, (1) the request is failed anyway and so the # below code will do nothing, and (2) the below will # trigger a recursive exception, breaking things, so we # just return here. return response if (not request.path.startswith("/static/") and not request.path.startswith("/api/") and not request.path.startswith("/json/")): subdomain = get_subdomain(request) if subdomain != Realm.SUBDOMAIN_FOR_ROOT_DOMAIN: try: get_realm(subdomain) except Realm.DoesNotExist: return render(request, "zerver/invalid_realm.html", status=404) """ If request.session was modified, or if the configuration is to save the session every time, save the changes and set a session cookie or delete the session cookie if the session has been emptied. """ try: accessed = request.session.accessed modified = request.session.modified empty = request.session.is_empty() except AttributeError: pass else: # First check if we need to delete this cookie. # The session should be deleted only if the session is entirely empty if settings.SESSION_COOKIE_NAME in request.COOKIES and empty: response.delete_cookie( settings.SESSION_COOKIE_NAME, path=settings.SESSION_COOKIE_PATH, domain=settings.SESSION_COOKIE_DOMAIN, ) else: if accessed: patch_vary_headers(response, ('Cookie',)) if (modified or settings.SESSION_SAVE_EVERY_REQUEST) and not empty: if request.session.get_expire_at_browser_close(): max_age = None expires = None else: max_age = request.session.get_expiry_age() expires_time = time.time() + max_age expires = http_date(expires_time) # Save the session data and refresh the client cookie. # Skip session save for 500 responses, refs #3881. if response.status_code != 500: try: request.session.save() except UpdateError: raise SuspiciousOperation( "The request's session was deleted before the " "request completed. The user may have logged " "out in a concurrent request, for example." ) host = request.get_host().split(':')[0] # The subdomains feature overrides the # SESSION_COOKIE_DOMAIN setting, since the setting # is a fixed value and with subdomains enabled, # the session cookie domain has to vary with the # subdomain. session_cookie_domain = host response.set_cookie( settings.SESSION_COOKIE_NAME, request.session.session_key, max_age=max_age, expires=expires, domain=session_cookie_domain, path=settings.SESSION_COOKIE_PATH, secure=settings.SESSION_COOKIE_SECURE or None, httponly=settings.SESSION_COOKIE_HTTPONLY or None, samesite=settings.SESSION_COOKIE_SAMESITE, ) return response class SetRemoteAddrFromForwardedFor(MiddlewareMixin): """ Middleware that sets REMOTE_ADDR based on the HTTP_X_FORWARDED_FOR. This middleware replicates Django's former SetRemoteAddrFromForwardedFor middleware. Because Zulip sits behind a NGINX reverse proxy, if the HTTP_X_FORWARDED_FOR is set in the request, then it has properly been set by NGINX. Therefore HTTP_X_FORWARDED_FOR's value is trusted. """ def process_request(self, request: HttpRequest) -> None: try: real_ip = request.META['HTTP_X_FORWARDED_FOR'] except KeyError: return None else: # HTTP_X_FORWARDED_FOR can be a comma-separated list of IPs. # For NGINX reverse proxy servers, the client's IP will be the first one. real_ip = real_ip.split(",")[0].strip() request.META['REMOTE_ADDR'] = real_ip def alter_content(request: HttpRequest, content: bytes) -> bytes: first_paragraph_text = get_content_description(content, request) return content.replace(request.placeholder_open_graph_description.encode("utf-8"), first_paragraph_text.encode("utf-8")) class FinalizeOpenGraphDescription(MiddlewareMixin): def process_response(self, request: HttpRequest, response: StreamingHttpResponse) -> StreamingHttpResponse: if getattr(request, "placeholder_open_graph_description", None) is not None: assert not response.streaming response.content = alter_content(request, response.content) return response class ZulipCommonMiddleware(CommonMiddleware): """ Patched version of CommonMiddleware to disable the APPEND_SLASH redirect behavior inside Tornado. While this has some correctness benefit in encouraging clients to implement the API correctly, this also saves about 600us in the runtime of every GET /events query, as the APPEND_SLASH route resolution logic is surprisingly expensive. TODO: We should probably extend this behavior to apply to all of our API routes. The APPEND_SLASH behavior is really only useful for non-API endpoints things like /login. But doing that transition will require more careful testing. """ def should_redirect_with_slash(self, request: HttpRequest) -> bool: if settings.RUNNING_INSIDE_TORNADO: return False return super().should_redirect_with_slash(request)