Bug #9688: Ruby's child process inherits parent's sockets (mswin)

• Status: Closed
• Priority: Normal
• Assignee: usa (Usaku NAKAMURA)
• Target version: 2.2.0
• ruby -v: ruby 2.1.1p76 (2014-02-24 revision 45161) [i386-mswin32_100]
• Backport: 2.0.0: DONE, 2.1: DONE

[arton (Akio Tajima)]

When Ruby application creates child process, sockets are inherited from the parent process.
This causes severe troubles.
In my situation, I have some web services using WEBrick and Sinatra. They invoke child process as a batch file using kernel.system method. And in the batch file I launch some long running applications by 'start'.
If these type of long running applications stay in running state, I never restart the services because the children grab server sockets while running. What is worse that Windows never report EADDRINUSE so I have no clue to judge its condition. Indeed 'netstat /b' reports the port is occupied by System not the child app.

Below is the reproduction script.

require 'socket'
require 'timeout'

exit unless RUBY_PLATFORM =~ /mswin/

BAT = "#{ENV['TMP']}#{File::SEPARATOR}test_inheritsock.bat"
File.open(BAT, 'w') do |fout|
  fout.puts 'start ruby -e "sleep(10)"'
end

port = nil
TCPServer.open(0) do |gs|
  port = gs.addr[1]
  system(BAT)
end

File.delete BAT

gs = TCPServer.open(port)

running = true
client = false
begin
  timeout(20) do
    while running
      Thread.start do
        s = gs.accept
        s.gets
        s.close
        running = false
      end
      unless client
        client = true
        Thread.start do
          TCPSocket.open('localhost', port) do |sock|
            sock.puts('')
          end
        end
      else
        sleep(1)
      end  
    end
  end
  puts 'no problem'
rescue Timeout::Error
  puts 'failed'
end  
gs.close

The second opend TCPServer can not receive a connection request.

Unak already made no inheritance patch (https://gist.github.com/unak/9825743) and I tested it with Windowds7(x86) and Windows8.1(x64) and in both environments the above script runs completely.

So I wonder if the patch is applied to the trunk.

Thanks in advance.

[usa (Usaku NAKAMURA)]

Thank you for testing my patch!

[usa (Usaku NAKAMURA)]

• Status changed from Open to Closed
• % Done changed from 0 to 100

Applied in changeset r45471.

---

• win32/win32.c (rb_w32_accept, open_ifs_socket, socketpair_internal): reset inherit flag of socket to avoid unintentional inheritance of socket. note that the return value of SetHandleInformation() is not verified intentionally because old Windows may return an error. [Bug #9688]

[usa (Usaku NAKAMURA)]

• Backport changed from 2.0.0: UNKNOWN, 2.1: UNKNOWN to 2.0.0: REQUIRED, 2.1: REQUIRED

[usa (Usaku NAKAMURA)]

• Backport changed from 2.0.0: REQUIRED, 2.1: REQUIRED to 2.0.0: DONE, 2.1: REQUIRED

backported into ruby_2_0_0 at r45753.

[nagachika (Tomoyuki Chikanaga)]

• Backport changed from 2.0.0: DONE, 2.1: REQUIRED to 2.0.0: DONE, 2.1: DONE

Backported into ruby_2_1 branch at r46305.