discourse/lib/middleware/request_tracker.rb

323 lines
8.8 KiB
Ruby

# frozen_string_literal: true
require 'method_profiler'
require 'middleware/anonymous_cache'
class Middleware::RequestTracker
@@detailed_request_loggers = nil
@@ip_skipper = nil
# You can add exceptions to our app rate limiter in the app.yml ENV section.
# example:
#
# env:
# DISCOURSE_MAX_REQS_PER_IP_EXCEPTIONS: >-
# 14.15.16.32/27
# 216.148.1.2
#
STATIC_IP_SKIPPER = ENV['DISCOURSE_MAX_REQS_PER_IP_EXCEPTIONS']&.split&.map { |ip| IPAddr.new(ip) }
# register callbacks for detailed request loggers called on every request
# example:
#
# Middleware::RequestTracker.detailed_request_logger(->|env, data| do
# # do stuff with env and data
# end
def self.register_detailed_request_logger(callback)
MethodProfiler.ensure_discourse_instrumentation!
(@@detailed_request_loggers ||= []) << callback
end
def self.unregister_detailed_request_logger(callback)
@@detailed_request_loggers.delete(callback)
if @@detailed_request_loggers.length == 0
@detailed_request_loggers = nil
end
end
# used for testing
def self.unregister_ip_skipper
@@ip_skipper = nil
end
# Register a custom `ip_skipper`, a function that will skip rate limiting
# for any IP that returns true.
#
# For example, if you never wanted to rate limit 1.2.3.4
#
# ```
# Middleware::RequestTracker.register_ip_skipper do |ip|
# ip == "1.2.3.4"
# end
# ```
def self.register_ip_skipper(&blk)
raise "IP skipper is already registered!" if @@ip_skipper
@@ip_skipper = blk
end
def initialize(app, settings = {})
@app = app
end
def self.log_request(data)
status = data[:status]
track_view = data[:track_view]
if track_view
if data[:is_crawler]
ApplicationRequest.increment!(:page_view_crawler)
WebCrawlerRequest.increment!(data[:user_agent])
elsif data[:has_auth_cookie]
ApplicationRequest.increment!(:page_view_logged_in)
ApplicationRequest.increment!(:page_view_logged_in_mobile) if data[:is_mobile]
elsif !SiteSetting.login_required
ApplicationRequest.increment!(:page_view_anon)
ApplicationRequest.increment!(:page_view_anon_mobile) if data[:is_mobile]
end
end
ApplicationRequest.increment!(:http_total)
if status >= 500
ApplicationRequest.increment!(:http_5xx)
elsif data[:is_background]
ApplicationRequest.increment!(:http_background)
elsif status >= 400
ApplicationRequest.increment!(:http_4xx)
elsif status >= 300
ApplicationRequest.increment!(:http_3xx)
elsif status >= 200
ApplicationRequest.increment!(:http_2xx)
end
end
def self.get_data(env, result, timing)
status, headers = result
status = status.to_i
helper = Middleware::AnonymousCache::Helper.new(env)
request = Rack::Request.new(env)
env_track_view = env["HTTP_DISCOURSE_TRACK_VIEW"]
track_view = status == 200
track_view &&= env_track_view != "0" && env_track_view != "false"
track_view &&= env_track_view || (request.get? && !request.xhr? && headers["Content-Type"] =~ /text\/html/)
track_view = !!track_view
h = {
status: status,
is_crawler: helper.is_crawler?,
has_auth_cookie: helper.has_auth_cookie?,
is_background: !!(request.path =~ /^\/message-bus\// || request.path =~ /\/topics\/timings/),
is_mobile: helper.is_mobile?,
track_view: track_view,
timing: timing,
queue_seconds: env['REQUEST_QUEUE_SECONDS']
}
if h[:is_crawler]
user_agent = env['HTTP_USER_AGENT']
if user_agent && (user_agent.encoding != Encoding::UTF_8)
user_agent = user_agent.encode("utf-8")
user_agent.scrub!
end
h[:user_agent] = user_agent
end
if cache = headers["X-Discourse-Cached"]
h[:cache] = cache
end
h
end
def log_request_info(env, result, info)
# we got to skip this on error ... its just logging
data = self.class.get_data(env, result, info) rescue nil
if data
if result && (headers = result[1])
headers["X-Discourse-TrackView"] = "1" if data[:track_view]
end
if @@detailed_request_loggers
@@detailed_request_loggers.each { |logger| logger.call(env, data) }
end
log_later(data)
end
end
def self.populate_request_queue_seconds!(env)
if !env['REQUEST_QUEUE_SECONDS']
if queue_start = env['HTTP_X_REQUEST_START']
queue_start = if queue_start.start_with?("t=")
queue_start.split("t=")[1].to_f
else
queue_start.to_f / 1000.0
end
queue_time = (Time.now.to_f - queue_start)
env['REQUEST_QUEUE_SECONDS'] = queue_time
end
end
end
def call(env)
result = nil
log_request = true
# doing this as early as possible so we have an
# accurate counter
::Middleware::RequestTracker.populate_request_queue_seconds!(env)
request = Rack::Request.new(env)
if available_in = rate_limit(request)
return [
429,
{ "Retry-After" => available_in.to_s },
["Slow down, too many requests from this IP address"]
]
end
env["discourse.request_tracker"] = self
MethodProfiler.start
result = @app.call(env)
info = MethodProfiler.stop
# possibly transferred?
if info && (headers = result[1])
headers["X-Runtime"] = "%0.6f" % info[:total_duration]
if GlobalSetting.enable_performance_http_headers
if redis = info[:redis]
headers["X-Redis-Calls"] = redis[:calls].to_s
headers["X-Redis-Time"] = "%0.6f" % redis[:duration]
end
if sql = info[:sql]
headers["X-Sql-Calls"] = sql[:calls].to_s
headers["X-Sql-Time"] = "%0.6f" % sql[:duration]
end
if queue = env['REQUEST_QUEUE_SECONDS']
headers["X-Queue-Time"] = "%0.6f" % queue
end
end
end
if env[Auth::DefaultCurrentUserProvider::BAD_TOKEN] && (headers = result[1])
headers['Discourse-Logged-Out'] = '1'
end
result
ensure
if (limiters = env['DISCOURSE_RATE_LIMITERS']) && env['DISCOURSE_IS_ASSET_PATH']
limiters.each(&:rollback!)
env['DISCOURSE_ASSET_RATE_LIMITERS'].each do |limiter|
begin
limiter.performed!
rescue RateLimiter::LimitExceeded
# skip
end
end
end
log_request_info(env, result, info) unless !log_request || env["discourse.request_tracker.skip"]
end
def is_private_ip?(ip)
ip = IPAddr.new(ip) rescue nil
!!(ip && (ip.private? || ip.loopback?))
end
def rate_limit(request)
if (
GlobalSetting.max_reqs_per_ip_mode == "block" ||
GlobalSetting.max_reqs_per_ip_mode == "warn" ||
GlobalSetting.max_reqs_per_ip_mode == "warn+block"
)
ip = request.ip
if !GlobalSetting.max_reqs_rate_limit_on_private
return false if is_private_ip?(ip)
end
return false if @@ip_skipper&.call(ip)
return false if STATIC_IP_SKIPPER&.any? { |entry| entry.include?(ip) }
limiter10 = RateLimiter.new(
nil,
"global_ip_limit_10_#{ip}",
GlobalSetting.max_reqs_per_ip_per_10_seconds,
10,
global: true,
aggressive: true
)
limiter60 = RateLimiter.new(
nil,
"global_ip_limit_60_#{ip}",
GlobalSetting.max_reqs_per_ip_per_minute,
60,
global: true,
aggressive: true
)
limiter_assets10 = RateLimiter.new(
nil,
"global_ip_limit_10_assets_#{ip}",
GlobalSetting.max_asset_reqs_per_ip_per_10_seconds,
10,
global: true
)
request.env['DISCOURSE_RATE_LIMITERS'] = [limiter10, limiter60]
request.env['DISCOURSE_ASSET_RATE_LIMITERS'] = [limiter_assets10]
warn = GlobalSetting.max_reqs_per_ip_mode == "warn" || GlobalSetting.max_reqs_per_ip_mode == "warn+block"
if !limiter_assets10.can_perform?
if warn
Discourse.warn("Global asset IP rate limit exceeded for #{ip}: 10 second rate limit", uri: request.env["REQUEST_URI"])
end
if GlobalSetting.max_reqs_per_ip_mode != "warn"
return limiter_assets10.seconds_to_wait(Time.now.to_i)
else
return false
end
end
begin
type = 10
limiter10.performed!
type = 60
limiter60.performed!
false
rescue RateLimiter::LimitExceeded => e
if warn
Discourse.warn("Global IP rate limit exceeded for #{ip}: #{type} second rate limit", uri: request.env["REQUEST_URI"])
if GlobalSetting.max_reqs_per_ip_mode != "warn"
e.available_in
else
false
end
else
e.available_in
end
end
end
end
def log_later(data)
Scheduler::Defer.later("Track view") do
unless Discourse.pg_readonly_mode?
self.class.log_request(data)
end
end
end
end