netselect for Debian
====================

running netselect without setuid root
-------------------------------------

Netselect needs to run as root since it currently uses RAW sockets for
it network tests. In UDP probe mode (traceroute) Netselect will 
send an UDP probe and then waits for an ICMP reply. In ICMP probe mode (-I),
Netselect will send an ICMP probe and waits for its reply.

If you want to to run netselect without setuid root and make the tool
available to regular uses, you can enable this through the use of file
capabilities on Linux.

Starting with linux >= 2.6.24 and using a filesystem supporting POSIX extended
attributes you can set the 'cap_net_raw' capability on netselect thanks to
setcap shipped inside libcap2-bin:

setcap cap_net_raw=ep /usr/bin/netselect

at this point you can remove setuid on netselect by doing:

chmod u-s /usr/bin/netselect

This is a known limitation, so please do not report it as a bug. Actually, this
has been reported already in
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=297439

To prevent this need netselect would need a rewrite to use full TCP
connections, and do traceroutes just like the 'tcptraceroute' program. If you
are able to develop such a patch, please forward it to the above bug report.

---- 
Javier Fernandez-Sanguino
Wed, 01 Dec 2010 00:30:17 +0100