RFR 8067105: Socket returned by ServerSocket.accept() is inherited by child process on Windows

[Ivan Gerasimov]

Hi Chris!

I think it's better to pass the last argument to SetHandleInformation as 
0 rather than FALSE.
This argument is DWORD flag, which is a bit subset of the second argument.

Sincerely yours,
Ivan

On 28.01.2015 23:01, Chris Hegarty wrote:
> Reviving an old code review [1], after further investigation…
>
> Pertinent details from previous review:
> "A socket connection which is returned by ServerSocket.accept() is
> inherited by a child process. The expected behavior is that the socket
> connection is not inherited by the child process. This is an oversight
> in the original implementation, that only sets HANDLE_FLAG_INHERIT for
> newly created sockets.
>
> The native socket returned by ServerSocket.accept() should be configured
> so it will not be inherited by a child process,
> SetHandleInformation(<HANDLE>, HANDLE_FLAG_INHERIT, FALSE)."
> http://cr.openjdk.java.net/~chegar/8067105/webrev.00/webrev/ 
> <http://cr.openjdk.java.net/%7Echegar/8067105/webrev.00/webrev/>
>
> —
>
> There were on objections to the changes, since they are mainly benign, 
> but I took the action to investigate why we are calling CreateProcess 
> with bInheritHandles set to TRUE. It appears that, without major work, 
> we cannot change this.
>
> From 7147084 [2]:
>
> Java does not provide the API to change inherit-bit for any handle. 
> More over, since at least the JDK 6, it is assumed that all 
> Java-created handles have no installed inherit-bit . The only handles 
> that change the inherit-bit to 1 in the Java call are the handles of 
> redirected Input, Output, and Error streams (IOE streams for short) 
> for child process. That is the way these redirect the streams work. 
> That's why we can not give up the nomination in [TRUE] the parameter 
> [bInheritHandles] in the [CreateProcess] call. And I want to mention 
> again that this is the only place in JDK where Java installs the 
> inherit-bit. Java itself does not use handle inheritance.
> —
>
> Ivan pointed out that HANDLE_FLAG_INHERIT will not always work, in the 
> case of Layered Service Providers, see [3], but it will work in the 
> standard case.
>
> Finally, I think that we will need to revisit the process creation 
> implementation at some point, to see if bInheritHandles can be set to 
> FALSE, but that is a larger, more significant, piece of work, that 
> should be done separately.
>
> -Chris.
>
> P.S. if there are no objections to the changes I will amend an 
> existing test case to cover these new cases.
>
> [1] 
> http://mail.openjdk.java.net/pipermail/net-dev/2014-December/008789.html
> [2] 
> https://bugs.openjdk.java.net/browse/JDK-7147084?focusedCommentId=13322689&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-13322689
> [3] 
> http://stackoverflow.com/questions/12058911/can-tcp-socket-handles-be-set-not-inheritable
>

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