C2SH(1)

NAME
poink - Nosuid, secure TCP/IP ping

SYNOPSIS

poink
    [ -i delay ] [ -c count ] [ -t timeout ] hostname

DESCRIPTION

Nosuid TCP/IP ping is a small, secure replacement for the original ping command. Unlike its setuid counterpart, it won't allow flood-pings, security compromises and other typical problems. It uses TCP syn-rst challenge/response instead of ICMP echo and echo-reply.

LIMITS
Of course, many advanced features are not implemented, but these are needed only for network supervisors already running at UID 0, so they could use original even with no suid at all. Nosuid ping is designed for lusers.

OPTIONS
Options are compatible with basic options of suid ping. ..PD 0

-d delay
    Delay between sending ping requests, in seconds (default 1 second, minimum - 1 second)

-c count
    Number of packets to send (default 0 - send until stopped)

-t timeout
    How long should we wait for packet (in seconds); by default, 4 seconds, minimum - 1 second; higher values might result in slightly inaccurate measurements due to TCP/IP retransmits.

OUTPUT
The output is compatible with original ping. When its work is done or the program caught Ctrl+C (SIGINT), short round-trip statistic is displayed.

BUGS
On some networks, TCP packets to high ports might be discarded silently by firewalls. In this case, poink will fail, just like a regular ping when ICMP is blocked.

AUTHOR
Michal Zalewski <lcamtuf@coredump.cx>