app/lib/request.rb
# frozen_string_literal: true
require 'ipaddr'
require 'socket'
require 'resolv'
# Use our own timeout class to avoid using HTTP.rb's timeout block
# around the Socket#open method, since we use our own timeout blocks inside
# that method
#
# Also changes how the read timeout behaves so that it is cumulative (closer
# to HTTP::Timeout::Global, but still having distinct timeouts for other
# operation types)
class PerOperationWithDeadline < HTTP::Timeout::PerOperation
READ_DEADLINE = 30
def initialize(*args)
super
@read_deadline = options.fetch(:read_deadline, READ_DEADLINE)
end
def connect(socket_class, host, port, nodelay = false)
@socket = socket_class.open(host, port)
@socket.setsockopt(Socket::IPPROTO_TCP, Socket::TCP_NODELAY, 1) if nodelay
end
# Reset deadline when the connection is re-used for different requests
def reset_counter
@deadline = nil
end
# Read data from the socket
def readpartial(size, buffer = nil)
@deadline ||= Process.clock_gettime(Process::CLOCK_MONOTONIC) + @read_deadline
timeout = false
loop do
result = @socket.read_nonblock(size, buffer, exception: false)
return :eof if result.nil?
remaining_time = @deadline - Process.clock_gettime(Process::CLOCK_MONOTONIC)
raise HTTP::TimeoutError, "Read timed out after #{@read_timeout} seconds" if timeout
raise HTTP::TimeoutError, "Read timed out after a total of #{@read_deadline} seconds" if remaining_time <= 0
return result if result != :wait_readable
# marking the socket for timeout. Why is this not being raised immediately?
# it seems there is some race-condition on the network level between calling
# #read_nonblock and #wait_readable, in which #read_nonblock signalizes waiting
# for reads, and when waiting for x seconds, it returns nil suddenly without completing
# the x seconds. In a normal case this would be a timeout on wait/read, but it can
# also mean that the socket has been closed by the server. Therefore we "mark" the
# socket for timeout and try to read more bytes. If it returns :eof, it's all good, no
# timeout. Else, the first timeout was a proper timeout.
# This hack has to be done because io/wait#wait_readable doesn't provide a value for when
# the socket is closed by the server, and HTTP::Parser doesn't provide the limit for the chunks.
timeout = true unless @socket.to_io.wait_readable([remaining_time, @read_timeout].min)
end
end
end
class Request
REQUEST_TARGET = '(request-target)'
# We enforce a 5s timeout on DNS resolving, 5s timeout on socket opening
# and 5s timeout on the TLS handshake, meaning the worst case should take
# about 15s in total
TIMEOUT = { connect_timeout: 5, read_timeout: 10, write_timeout: 10, read_deadline: 30 }.freeze
include RoutingHelper
def initialize(verb, url, **options)
raise ArgumentError if url.blank?
@verb = verb
@url = Addressable::URI.parse(url).normalize
@http_client = options.delete(:http_client)
@allow_local = options.delete(:allow_local)
@full_path = !options.delete(:omit_query_string)
@options = options.merge(socket_class: use_proxy? || @allow_local ? ProxySocket : Socket)
@options = @options.merge(timeout_class: PerOperationWithDeadline, timeout_options: TIMEOUT)
@options = @options.merge(proxy_url) if use_proxy?
@headers = {}
raise Mastodon::HostValidationError, 'Instance does not support hidden service connections' if block_hidden_service?
set_common_headers!
set_digest! if options.key?(:body)
end
def on_behalf_of(actor, sign_with: nil)
raise ArgumentError, 'actor must not be nil' if actor.nil?
@actor = actor
@keypair = sign_with.present? ? OpenSSL::PKey::RSA.new(sign_with) : @actor.keypair
self
end
def add_headers(new_headers)
@headers.merge!(new_headers)
self
end
def perform
begin
response = http_client.request(@verb, @url.to_s, @options.merge(headers: headers))
rescue => e
raise e.class, "#{e.message} on #{@url}", e.backtrace[0]
end
begin
# If we are using a persistent connection, we have to
# read every response to be able to move forward at all.
# However, simply calling #to_s or #flush may not be safe,
# as the response body, if malicious, could be too big
# for our memory. So we use the #body_with_limit method
response.body_with_limit if http_client.persistent?
yield response if block_given?
ensure
http_client.close unless http_client.persistent?
end
end
def headers
(@actor ? @headers.merge('Signature' => signature) : @headers).without(REQUEST_TARGET)
end
class << self
def valid_url?(url)
begin
parsed_url = Addressable::URI.parse(url)
rescue Addressable::URI::InvalidURIError
return false
end
%w(http https).include?(parsed_url.scheme) && parsed_url.host.present?
end
def http_client
HTTP.use(:auto_inflate).follow(max_hops: 3)
end
end
private
def set_common_headers!
@headers[REQUEST_TARGET] = request_target
@headers['User-Agent'] = Mastodon::Version.user_agent
@headers['Host'] = @url.host
@headers['Date'] = Time.now.utc.httpdate
@headers['Accept-Encoding'] = 'gzip' if @verb != :head
end
def set_digest!
@headers['Digest'] = "SHA-256=#{Digest::SHA256.base64digest(@options[:body])}"
end
def request_target
if @url.query.nil? || !@full_path
"#{@verb} #{@url.path}"
else
"#{@verb} #{@url.path}?#{@url.query}"
end
end
def signature
algorithm = 'rsa-sha256'
signature = Base64.strict_encode64(@keypair.sign(OpenSSL::Digest.new('SHA256'), signed_string))
"keyId=\"#{key_id}\",algorithm=\"#{algorithm}\",headers=\"#{signed_headers.keys.join(' ').downcase}\",signature=\"#{signature}\""
end
def signed_string
signed_headers.map { |key, value| "#{key.downcase}: #{value}" }.join("\n")
end
def signed_headers
@headers.without('User-Agent', 'Accept-Encoding')
end
def key_id
ActivityPub::TagManager.instance.key_uri_for(@actor)
end
def http_client
@http_client ||= Request.http_client
end
def use_proxy?
proxy_url.present?
end
def proxy_url
if hidden_service? && Rails.configuration.x.http_client_hidden_proxy.present?
Rails.configuration.x.http_client_hidden_proxy
else
Rails.configuration.x.http_client_proxy
end
end
def block_hidden_service?
!Rails.configuration.x.access_to_hidden_service && hidden_service?
end
def hidden_service?
/\.(onion|i2p)$/.match?(@url.host)
end
module ClientLimit
def truncated_body(limit = 1.megabyte)
if charset.nil?
encoding = Encoding::BINARY
else
begin
encoding = Encoding.find(charset)
rescue ArgumentError
encoding = Encoding::BINARY
end
end
contents = String.new(encoding: encoding)
while (chunk = readpartial)
contents << chunk
chunk.clear
break if contents.bytesize > limit
end
contents
end
def body_with_limit(limit = 1.megabyte)
require_limit_not_exceeded!(limit)
contents = truncated_body(limit)
raise Mastodon::LengthValidationError, "Body size exceeds limit of #{limit}" if contents.bytesize > limit
contents
end
def require_limit_not_exceeded!(limit)
raise Mastodon::LengthValidationError, "Content-Length #{content_length} exceeds limit of #{limit}" if content_length.present? && content_length > limit
end
end
if ::HTTP::Response.methods.include?(:body_with_limit) && !Rails.env.production?
abort 'HTTP::Response#body_with_limit is already defined, the monkey patch will not be applied'
else
class ::HTTP::Response
include Request::ClientLimit
end
end
class Socket < TCPSocket
class << self
def open(host, *args)
outer_e = nil
port = args.first
addresses = []
begin
addresses = [IPAddr.new(host)]
rescue IPAddr::InvalidAddressError
Resolv::DNS.open do |dns|
dns.timeouts = 5
addresses = dns.getaddresses(host)
addresses = addresses.filter { |addr| addr.is_a?(Resolv::IPv6) }.take(2) + addresses.filter { |addr| !addr.is_a?(Resolv::IPv6) }.take(2)
end
end
socks = []
addr_by_socket = {}
addresses.each do |address|
check_private_address(address, host)
sock = ::Socket.new(address.is_a?(Resolv::IPv6) ? ::Socket::AF_INET6 : ::Socket::AF_INET, ::Socket::SOCK_STREAM, 0)
sockaddr = ::Socket.pack_sockaddr_in(port, address.to_s)
sock.setsockopt(::Socket::IPPROTO_TCP, ::Socket::TCP_NODELAY, 1)
sock.connect_nonblock(sockaddr)
# If that hasn't raised an exception, we somehow managed to connect
# immediately, close pending sockets and return immediately
socks.each(&:close)
return sock
rescue IO::WaitWritable
socks << sock
addr_by_socket[sock] = sockaddr
rescue => e
outer_e = e
end
until socks.empty?
_, available_socks, = IO.select(nil, socks, nil, Request::TIMEOUT[:connect_timeout])
if available_socks.nil?
socks.each(&:close)
raise HTTP::TimeoutError, "Connect timed out after #{Request::TIMEOUT[:connect_timeout]} seconds"
end
available_socks.each do |sock|
socks.delete(sock)
begin
sock.connect_nonblock(addr_by_socket[sock])
rescue Errno::EISCONN
# Do nothing
rescue => e
sock.close
outer_e = e
next
end
socks.each(&:close)
return sock
end
end
if outer_e
raise outer_e
else
raise SocketError, "No address for #{host}"
end
end
alias new open
def check_private_address(address, host)
addr = IPAddr.new(address.to_s)
return if Rails.env.development? || Rails.configuration.x.private_address_exceptions.any? { |range| range.include?(addr) }
raise Mastodon::PrivateNetworkAddressError, host if PrivateAddressCheck.private_address?(addr)
end
end
end
class ProxySocket < Socket
class << self
def check_private_address(_address, _host)
# Accept connections to private addresses as HTTP proxies will usually
# be on local addresses
nil
end
end
end
private_constant :ClientLimit, :Socket, :ProxySocket
end