happy is a simple TCP happy eyeballs probing tool. It uses non‐blocking connect() calls to establish connections concurrently to a number of possible endpoints. This tool is particularly useful to determine whether happy eyeball [RFC 6555] applications will use IPv4 or IPv6 if both are available.

The build environment uses cmake and hence the code should be fairly portable. However, patches that improve portability of fix bugs are always welcome.

Build and Usage:

$ mkdir builddir
$ cd builddir
$ cmake ..
$ make
$ make install

$ happy -ac www.ietf.org www.facebook.com www.bing.com
www.ietf.org:80
 www.ietf.org.cdn.cloudflare.net > 2400:cb00:2048:1::6814:155
 www.ietf.org.cdn.cloudflare.net > 2400:cb00:2048:1::6814:55
 www.ietf.org.cdn.cloudflare.net > 104.20.1.85
 www.ietf.org.cdn.cloudflare.net > 104.20.0.85

www.facebook.com:80
 star.c10r.facebook.com > 2a03:2880:f01c:d01:face:b00c::1 >
edge-star6-shv-14-fra3.facebook.com
 star.c10r.facebook.com > 31.13.93.241 >
edge-star-shv-14-fra3.facebook.com

www.bing.com:80
 any.edge.bing.com > 204.79.197.200 > a-0001.a-msedge.net

www.ietf.org:80
 2400:cb00:2048:1::6814:155                   8.297    8.411    8.759
 2400:cb00:2048:1::6814:55                    8.573    8.767    8.573
 104.20.1.85                                 12.824   14.677   14.584
 104.20.0.85                                 12.794   14.573   12.746

www.facebook.com:80
 2a03:2880:f01c:d01:face:b00c::1              8.678    8.471    8.902
 31.13.93.241                                 9.268    8.441    8.285

www.bing.com:80
 204.79.197.200                              24.434   26.091   26.309

Options:

% happy -h
Usage: happy [-a] [-b] [-c] [-p port] [-q nqueries] [-t timeout] [-d
delay ] [-f file] [-s] [-m] hostname...

The description of each option is available in the man page:

$ man happy

Limitations:

The tool does not check whether the endpoints of a given target all provide the same service. Hence, it is possible to impact the results by setting up ’fake’ servers that do not provide the service tested and which are designed and deployed with the only purpose to provide fast connection setup times.

Author:

• Juergen Schoenwaelder <j.schoenwaelder AT jacobs‐university.de>
• Vaibhav Bajpai <v.bajpai AT jacobs‐university.de>

License:

Copyright (c) 2013-2014, Juergen Schoenwaelder, Jacobs University Bremen
Copyright (c) 2014, Vaibhav Bajpai, Jacobs University Bremen
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:

1. Redistributions of source code must retain the above copyright
   notice, this list of conditions and the following disclaimer.

2. Redistributions in binary form must reproduce the above
   copyright notice, this list of conditions and the following
   disclaimer in the documentation and/or other materials provided
   with the distribution.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
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The views and conclusions contained in the software and
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interpreted as representing official policies, either expressed or
implied, of the Leone Project or Jacobs University Bremen.