1#!/usr/bin/perl -w 2# 3# CDDL HEADER START 4# 5# The contents of this file are subject to the terms of the 6# Common Development and Distribution License (the "License"). 7# You may not use this file except in compliance with the License. 8# 9# You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10# or http://www.opensolaris.org/os/licensing. 11# See the License for the specific language governing permissions 12# and limitations under the License. 13# 14# When distributing Covered Code, include this CDDL HEADER in each 15# file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16# If applicable, add the following below this CDDL HEADER, with the 17# fields enclosed by brackets "[]" replaced with your own identifying 18# information: Portions Copyright [yyyy] [name of copyright owner] 19# 20# CDDL HEADER END 21# 22 23# 24# Copyright 2008 Sun Microsystems, Inc. All rights reserved. 25# Use is subject to license terms. 26# 27#pragma ident "%Z%%M% %I% %E% SMI" 28 29# 30# get.ipv4remote.pl [tcpport] 31# 32# Find an IPv4 reachable remote host using both ifconfig(1M) and ping(1M). 33# If a tcpport is specified, return a host that is also listening on this 34# TCP port. Print the local address and the remote address, or an 35# error message if no suitable remote host was found. Exit status is 0 if 36# a host was found. 37# 38 39use strict; 40use IO::Socket; 41 42my $MAXHOSTS = 32; # max hosts to port scan 43my $TIMEOUT = 3; # connection timeout 44my $tcpport = @ARGV == 1 ? $ARGV[0] : 0; 45 46# 47# Determine local IP address 48# 49my $local = ""; 50my $remote = ""; 51my %Broadcast; 52my $up; 53open IFCONFIG, '/usr/sbin/ifconfig -a |' or die "Couldn't run ifconfig: $!\n"; 54while (<IFCONFIG>) { 55 next if /^lo/; 56 57 # "UP" is always printed first (see print_flags() in ifconfig.c): 58 $up = 1 if /^[a-z].*<UP,/; 59 $up = 0 if /^[a-z].*<,/; 60 61 # assume output is "inet X ... broadcast Z": 62 if (/inet (\S+) .* broadcast (\S+)/) { 63 my ($addr, $bcast) = ($1, $2); 64 $Broadcast{$addr} = $bcast; 65 $local = $addr if $up and $local eq ""; 66 $up = 0; 67 } 68} 69close IFCONFIG; 70die "Could not determine local IP address" if $local eq ""; 71 72# 73# Find the first remote host that responds to an icmp echo, 74# which isn't a local address. 75# 76open PING, "/usr/sbin/ping -ns $Broadcast{$local} 56 $MAXHOSTS |" or 77 die "Couldn't run ping: $!\n"; 78while (<PING>) { 79 if (/bytes from (.*): / and not defined $Broadcast{$1}) { 80 my $addr = $1; 81 82 if ($tcpport != 0) { 83 # 84 # Test TCP 85 # 86 my $socket = IO::Socket::INET->new( 87 Proto => "tcp", 88 PeerAddr => $addr, 89 PeerPort => $tcpport, 90 Timeout => $TIMEOUT, 91 ); 92 next unless $socket; 93 close $socket; 94 } 95 96 $remote = $addr; 97 last; 98 } 99} 100close PING; 101die "Can't find a remote host for testing: No suitable response from " . 102 "$Broadcast{$local}\n" if $remote eq ""; 103 104print "$local $remote\n"; 105