Class: WEBrick::HTTPProxyServer

Inherits:
HTTPServer show all
Defined in:
lib/webrick/httpproxy.rb

Constant Summary collapse

HopByHop =

Some header fields shuold not be transfered.

%w( connection keep-alive proxy-authenticate upgrade
proxy-authorization te trailers transfer-encoding )
ShouldNotTransfer = 
%w( set-cookie proxy-connection )

Instance Attribute Summary

Attributes inherited from GenericServer

#config, #listeners, #logger, #status, #tokens

Instance Method Summary collapse

Methods inherited from HTTPServer

#access_log, #lookup_server, #mount, #mount_proc, #run, #search_servlet, #unmount, #virtual_host

Methods inherited from GenericServer

#[], #listen, #run, #setup_ssl_context, #shutdown, #ssl_context, #start, #stop

Constructor Details

#initialize(config) ⇒ HTTPProxyServer

Returns a new instance of HTTPProxyServer.



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# File 'lib/webrick/httpproxy.rb', line 27

def initialize(config)
  super
  c = @config
  @via = "#{c[:HTTPVersion]} #{c[:ServerName]}:#{c[:Port]}"
end

Instance Method Details

#choose_header(src, dst) ⇒ Object 



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# File 'lib/webrick/httpproxy.rb', line 56

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

#do_OPTIONS(req, res) ⇒ Object 



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# File 'lib/webrick/httpproxy.rb', line 250

def do_OPTIONS(req, res)
  res['allow'] = "GET,HEAD,POST,OPTIONS,CONNECT"
end

#proxy_auth(req, res) ⇒ Object 



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# File 'lib/webrick/httpproxy.rb', line 43

def proxy_auth(req, res)
  if proc = @config[:ProxyAuthProc]
    proc.call(req, res)
  end
  req.header.delete("proxy-authorization")
end

#proxy_connect(req, res) ⇒ Object

Raises:



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# File 'lib/webrick/httpproxy.rb', line 169

def proxy_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*")
      credentials.chomp!
    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 sesponse 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.size} byte from User-Agent")
        os.syswrite(buf)
      elsif fds[0].member?(os)
        buf = os.sysread(1024);
        @logger.debug("CONNECT: #{buf.size} byte from #{host}:#{port}")
        ua.syswrite(buf)
      end
    end
  rescue => ex
    os.close
    @logger.debug("CONNECT #{host}:#{port}: closed")
  end

  raise HTTPStatus::EOFError
end

#proxy_service(req, res) ⇒ Object 



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# File 'lib/webrick/httpproxy.rb', line 102

def proxy_service(req, res)
  # Proxy Authentication
  proxy_auth(req, res)      

  # Create Request-URI to send to the origin server
  uri  = req.request_uri
  path = uri.path.dup
  path << "?" << uri.query if uri.query

  # Choose header fields to transfer
  header = Hash.new
  choose_header(req, header)
  set_via(header)

  # select upstream proxy server
  if proxy = proxy_uri(req, res)
    proxy_host = proxy.host
    proxy_port = proxy.port
    if proxy.userinfo
      credentials = "Basic " + [proxy.userinfo].pack("m*")
      credentials.chomp!
      header['proxy-authorization'] = credentials
    end
  end

  response = nil
  begin
    http = Net::HTTP.new(uri.host, uri.port, proxy_host, proxy_port)
    http.start{
      if @config[:ProxyTimeout]
        ##################################   these issues are 
        http.open_timeout = 30   # secs  #   necessary (maybe bacause
        http.read_timeout = 60   # secs  #   Ruby's bug, but why?)
        ##################################
      end
      case req.request_method
      when "GET"  then response = http.get(path, header)
      when "POST" then response = http.post(path, req.body || "", header)
      when "HEAD" then response = http.head(path, header)
      else
        raise HTTPStatus::MethodNotAllowed,
          "unsupported method `#{req.request_method}'."
      end
    }
  rescue => err
    logger.debug("#{err.class}: #{err.message}")
    raise HTTPStatus::ServiceUnavailable, err.message
  end
  
  # Persistent connction 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::HTTPProxy
  res.status = response.code.to_i
  choose_header(response, res)
  set_cookie(response, res)
  set_via(res)
  res.body = response.body

  # Process contents
  if handler = @config[:ProxyContentHandler]
    handler.call(req, res)
  end
end

#proxy_uri(req, res) ⇒ Object 



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# File 'lib/webrick/httpproxy.rb', line 98

def proxy_uri(req, res)
  @config[:ProxyURI]
end

#service(req, res) ⇒ Object 



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# File 'lib/webrick/httpproxy.rb', line 33

def service(req, res)
  if req.request_method == "CONNECT"
    proxy_connect(req, res)
  elsif req.unparsed_uri =~ %r!^http://!
    proxy_service(req, res)
  else
    super(req, res)
  end
end

#set_cookie(src, dst) ⇒ Object

Net::HTTP is stupid about the multiple header fields. Here is workaround:



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# File 'lib/webrick/httpproxy.rb', line 72

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

#set_via(h) ⇒ Object 



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# File 'lib/webrick/httpproxy.rb', line 88

def set_via(h)
  if @config[:ProxyVia]
    if  h['via']
      h['via'] << ", " << @via
    else
      h['via'] = @via
    end
  end
end

#split_field(f) ⇒ Object 



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# File 'lib/webrick/httpproxy.rb', line 54

def split_field(f) f ? f.split(/,\s+/).collect{|i| i.downcase } : [] end