the-bastion/bin/plugin/open/nc
2024-04-09 17:26:39 +02:00

97 lines
2.2 KiB
Perl
Executable file

#! /usr/bin/env perl
# vim: set filetype=perl ts=4 sw=4 sts=4 et:
use common::sense;
use IO::Socket;
use File::Basename;
use lib dirname(__FILE__) . '/../../../lib/perl';
use OVH::Result;
use OVH::Bastion;
use OVH::Bastion::Plugin qw( :DEFAULT help );
my $remainingOptions = OVH::Bastion::Plugin::begin(
argv => \@ARGV,
header => "simulate a netcat -z",
options => {"w=i" => \my $timeout},
helptext => <<'EOF',
Check whether a remote TCP port is open
Usage: --osh SCRIPT_NAME [--host] HOST [--port] PORT [-w TIMEOUT]
--host HOST Host or IP to attempt to connect to
--port PORT TCP port to attempt to connect to
-w SECONDS Timeout in seconds (default: 3)
EOF
);
# be nice and try to guessify a host as first param and port as second param
# if user said --osh nc mymachine.example.org 22
if ( not $host
and not $ip
and not $port
and ref $remainingOptions eq 'ARRAY'
and @$remainingOptions == 2
and $remainingOptions->[0] =~ /^[a-zA-Z0-9][a-zA-Z0-9.-]{1,}$/
and $remainingOptions->[1] =~ /^\d+$/)
{
($host, $port) = @$remainingOptions;
}
#
# code
#
my $fnret;
if (not $host) {
help();
osh_exit 'ERR_MISSING_PARAMETER', "Missing required host parameter";
}
if (not $port) {
help();
osh_exit 'ERR_MISSING_PARAMETER', "Missing required port parameter";
}
$fnret = OVH::Bastion::is_valid_port(port => $port);
if (!$fnret) {
help();
osh_exit $fnret;
}
osh_info "Checking whether TCP port $port of $host is reachable...";
my $Sock = IO::Socket->new(
Domain => IO::Socket::AF_INET,
Type => IO::Socket::SOCK_STREAM,
Proto => 'tcp',
Timeout => ($timeout and $timeout > 0 and $timeout <= 3600) ? $timeout : 3,
PeerAddr => $host,
PeerPort => $port,
);
my $errmsg = $@;
$errmsg =~ s{IO::Socket(::[a-zA-Z0-9]*)?: }{};
$errmsg =~ s{connect: }{};
# try to guess what happened
my $answer = 'unknown';
if ($Sock) {
$answer = 'open';
osh_info("Port $port is open");
}
elsif ($errmsg =~ m{refused}i) {
$answer = 'closed';
osh_info("Port $port is closed");
}
elsif ($errmsg =~ m{timeout}i) {
$answer = 'timeout';
osh_info("Connection timed out");
}
osh_ok {
host => $host,
port => $port + 0,
result => $answer,
};