SNTP Client for Virtual PC

This is a patch received from Jean-Alain Le Borgne <jalb@pobox.com> on
2007-03-26. It adds the ability to periodically synchronize the time with
alarm(2) instead of sleep(3), in order to fix the problem that in some
cases vsntp won't work after Virtual PC suspended for a while. It also
adds some more debug information. As I have not read this patch throughly
and incorporated it into the vsntp code, I put it here for now. The
original mail follows.


Forwarded by imacat <imacat@mail.imacat.idv.tw>
----------------------- Original Message -----------------------
From: "Jean-Alain Le Borgne" <jalb@pobox.com>
To: imacat@mail.imacat.idv.tw
Date: Mon, 26 Mar 2007 11:31:15 +0200
Subject: vsntp modification
----

Hello,

I'm working with Virtual PC (2007) these days and had to find a
solution to the clock drift problem. I found your software verty
handy, thanks a lot for writing it and making it available.

I noticed that, after pausing ot suspending the VM for a while, vsntp
would get stuck in the recv call, so I modified the code to use alarm
signals, instead of a loop with sleep call, to schedule the
synchronization. I'm still testing it, but it seems the alarm method
doesn't get stuck. I guess the problem in recv is caused by a defect
in the virtualization of the network.

The modified version is in the attached tar.gz, the changes are only
in vsntp.c. It is backward compatible, the new method is enabled with
a new "-a" option. I also added a "-d" option to send more information
to the log. Please let me know if you wish to get the code changes in
another form.

Best regards and thanks again,

Jean-Alain Le Borgne
http://jalb.org

--------------------- Original Message Ends --------------------