#
# httpproxy.rb -- HTTPProxy Class
#
# Author: IPR -- Internet Programming with Ruby -- writers
# Copyright (c) 2002 GOTO Kentaro
# Copyright (c) 2002 Internet Programming with Ruby writers. All rights
# reserved.
#
# $IPR: httpproxy.rb,v 1.18 2003/03/08 18:58:10 gotoyuzo Exp $
# $kNotwork: straw.rb,v 1.3 2002/02/12 15:13:07 gotoken Exp $
require "webrick/httpserver"
require "net/http"
Net::HTTP::version_1_2 if RUBY_VERSION < "1.7"
module WEBrick
NullReader = Object.new # :nodoc:
class << NullReader # :nodoc:
def read(*args)
nil
end
alias gets read
end
FakeProxyURI = Object.new # :nodoc:
class << FakeProxyURI # :nodoc:
def method_missing(meth, *args)
if %w(scheme host port path query userinfo).member?(meth.to_s)
return nil
end
super
end
end
# :startdoc:
##
# An HTTP Proxy server which proxies GET, HEAD and POST requests.
#
# To create a simple proxy server:
#
# require 'webrick'
# require 'webrick/httpproxy'
#
# proxy = WEBrick::HTTPProxyServer.new Port: 8000
#
# trap 'INT' do proxy.shutdown end
# trap 'TERM' do proxy.shutdown end
#
# proxy.start
#
# See ::new for proxy-specific configuration items.
#
# == Modifying proxied responses
#
# To modify content the proxy server returns use the +:ProxyContentHandler+
# option:
#
# handler = proc do |req, res|
# if res['content-type'] == 'text/plain' then
# res.body << "\nThis content was proxied!\n"
# end
# end
#
# proxy =
# WEBrick::HTTPProxyServer.new Port: 8000, ProxyContentHandler: handler
class HTTPProxyServer < HTTPServer
##
# Proxy server configurations. The proxy server handles the following
# configuration items in addition to those supported by HTTPServer:
#
# :ProxyAuthProc:: Called with a request and response to authorize a
# request
# :ProxyVia:: Appended to the via header
# :ProxyURI:: The proxy server's URI
# :ProxyContentHandler:: Called with a request and response and allows
# modification of the response
# :ProxyTimeout:: Sets the proxy timeouts to 30 seconds for open and 60
# seconds for read operations
def initialize(config={}, default=Config::HTTP)
super(config, default)
c = @config
@via = "#{c[:HTTPVersion]} #{c[:ServerName]}:#{c[:Port]}"
end
# :stopdoc:
def service(req, res)
if req.request_method == "CONNECT"
do_CONNECT(req, res)
elsif req.unparsed_uri =~ %r!^http://!
proxy_service(req, res)
else
super(req, res)
end
end
def proxy_auth(req, res)
if proc = @config[:ProxyAuthProc]
proc.call(req, res)
end
req.header.delete("proxy-authorization")
end
def proxy_uri(req, res)
# should return upstream proxy server's URI
return @config[:ProxyURI]
end
def proxy_service(req, res)
# Proxy Authentication
proxy_auth(req, res)
begin
self.send("do_#{req.request_method}", req, res)
rescue NoMethodError
raise HTTPStatus::MethodNotAllowed,
"unsupported method `#{req.request_method}'."
rescue => err
logger.debug("#{err.class}: #{err.message}")
raise HTTPStatus::ServiceUnavailable, err.message
end
# Process contents
if handler = @config[:ProxyContentHandler]
handler.call(req, res)
end
end
def do_CONNECT(req, res)
# Proxy Authentication
proxy_auth(req, res)
ua = Thread.current[:WEBrickSocket] # User-Agent
raise HTTPStatus::InternalServerError,
"[BUG] cannot get socket" unless ua
host, port = req.unparsed_uri.split(":", 2)
# Proxy authentication for upstream proxy server
if proxy = proxy_uri(req, res)
proxy_request_line = "CONNECT #{host}:#{port} HTTP/1.0"
if proxy.userinfo
credentials = "Basic " + [proxy.userinfo].pack("m").delete("\n")
end
host, port = proxy.host, proxy.port
end
begin
@logger.debug("CONNECT: upstream proxy is `#{host}:#{port}'.")
os = TCPSocket.new(host, port) # origin server
if proxy
@logger.debug("CONNECT: sending a Request-Line")
os << proxy_request_line << CRLF
@logger.debug("CONNECT: > #{proxy_request_line}")
if credentials
@logger.debug("CONNECT: sending a credentials")
os << "Proxy-Authorization: " << credentials << CRLF
end
os << CRLF
proxy_status_line = os.gets(LF)
@logger.debug("CONNECT: read a Status-Line form the upstream server")
@logger.debug("CONNECT: < #{proxy_status_line}")
if %r{^HTTP/\d+\.\d+\s+200\s*} =~ proxy_status_line
while line = os.gets(LF)
break if /\A(#{CRLF}|#{LF})\z/om =~ line
end
else
raise HTTPStatus::BadGateway
end
end
@logger.debug("CONNECT #{host}:#{port}: succeeded")
res.status = HTTPStatus::RC_OK
rescue => ex
@logger.debug("CONNECT #{host}:#{port}: failed `#{ex.message}'")
res.set_error(ex)
raise HTTPStatus::EOFError
ensure
if handler = @config[:ProxyContentHandler]
handler.call(req, res)
end
res.send_response(ua)
access_log(@config, req, res)
# Should clear request-line not to send the response twice.
# see: HTTPServer#run
req.parse(NullReader) rescue nil
end
begin
while fds = IO::select([ua, os])
if fds[0].member?(ua)
buf = ua.sysread(1024);
@logger.debug("CONNECT: #{buf.bytesize} byte from User-Agent")
os.syswrite(buf)
elsif fds[0].member?(os)
buf = os.sysread(1024);
@logger.debug("CONNECT: #{buf.bytesize} byte from #{host}:#{port}")
ua.syswrite(buf)
end
end
rescue => ex
os.close
@logger.debug("CONNECT #{host}:#{port}: closed")
end
raise HTTPStatus::EOFError
end
def do_GET(req, res)
perform_proxy_request(req, res) do |http, path, header|
http.get(path, header)
end
end
def do_HEAD(req, res)
perform_proxy_request(req, res) do |http, path, header|
http.head(path, header)
end
end
def do_POST(req, res)
perform_proxy_request(req, res) do |http, path, header|
http.post(path, req.body || "", header)
end
end
def do_OPTIONS(req, res)
res['allow'] = "GET,HEAD,POST,OPTIONS,CONNECT"
end
private
# Some header fields should not be transferred.
HopByHop = %w( connection keep-alive proxy-authenticate upgrade
proxy-authorization te trailers transfer-encoding )
ShouldNotTransfer = %w( set-cookie proxy-connection )
def split_field(f) f ? f.split(/,\s+/).collect{|i| i.downcase } : [] end
def choose_header(src, dst)
connections = split_field(src['connection'])
src.each{|key, value|
key = key.downcase
if HopByHop.member?(key) || # RFC2616: 13.5.1
connections.member?(key) || # RFC2616: 14.10
ShouldNotTransfer.member?(key) # pragmatics
@logger.debug("choose_header: `#{key}: #{value}'")
next
end
dst[key] = value
}
end
# Net::HTTP is stupid about the multiple header fields.
# Here is workaround:
def set_cookie(src, dst)
if str = src['set-cookie']
cookies = []
str.split(/,\s*/).each{|token|
if /^[^=]+;/o =~ token
cookies[-1] << ", " << token
elsif /=/o =~ token
cookies << token
else
cookies[-1] << ", " << token
end
}
dst.cookies.replace(cookies)
end
end
def set_via(h)
if @config[:ProxyVia]
if h['via']
h['via'] << ", " << @via
else
h['via'] = @via
end
end
end
def setup_proxy_header(req, res)
# Choose header fields to transfer
header = Hash.new
choose_header(req, header)
set_via(header)
return header
end
def setup_upstream_proxy_authentication(req, res, header)
if upstream = proxy_uri(req, res)
if upstream.userinfo
header['proxy-authorization'] =
"Basic " + [upstream.userinfo].pack("m").delete("\n")
end
return upstream
end
return FakeProxyURI
end
def perform_proxy_request(req, res)
uri = req.request_uri
path = uri.path.dup
path << "?" << uri.query if uri.query
header = setup_proxy_header(req, res)
upstream = setup_upstream_proxy_authentication(req, res, header)
response = nil
http = Net::HTTP.new(uri.host, uri.port, upstream.host, upstream.port)
http.start do
if @config[:ProxyTimeout]
################################## these issues are
http.open_timeout = 30 # secs # necessary (maybe because
http.read_timeout = 60 # secs # Ruby's bug, but why?)
##################################
end
response = yield(http, path, header)
end
# Persistent connection requirements are mysterious for me.
# So I will close the connection in every response.
res['proxy-connection'] = "close"
res['connection'] = "close"
# Convert Net::HTTP::HTTPResponse to WEBrick::HTTPResponse
res.status = response.code.to_i
choose_header(response, res)
set_cookie(response, res)
set_via(res)
res.body = response.body
end
# :stopdoc:
end
end