1#!/usr/bin/env perl 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 [port] [proto] 31# 32# Find an IPv4 reachable remote host using both ifconfig(1M) and ping(1M). 33# If a port is specified, return a host that is also listening on this 34# port. If the port is specified, the protocol can also be specified and 35# defaults to tcp. Print the local address and the remote address, or an 36# error message if no suitable remote host was found. Exit status is 0 if 37# a host was found. 38# 39 40use strict; 41use IO::Socket; 42 43my $MAXHOSTS = 32; # max hosts to port scan 44my $TIMEOUT = 3; # connection timeout 45my $port = @ARGV >= 1 ? $ARGV[0] : 0; 46my $proto = @ARGV == 2 ? $ARGV[1] : "tcp"; 47 48# 49# Determine local IP address 50# 51my $local = ""; 52my $remote = ""; 53my %Broadcast; 54my $up; 55open IFCONFIG, '/sbin/ifconfig -a |' or die "Couldn't run ifconfig: $!\n"; 56while (<IFCONFIG>) { 57 next if /^lo/; 58 59 # "UP" is always printed first (see print_flags() in ifconfig.c): 60 $up = 1 if /^[a-z].*<UP,/; 61 $up = 0 if /^[a-z].*<,/; 62 63 # assume output is "inet X ... broadcast Z": 64 if (/inet (\S+) .* broadcast (\S+)/) { 65 my ($addr, $bcast) = ($1, $2); 66 $Broadcast{$addr} = $bcast; 67 $local = $addr if $up and $local eq ""; 68 $up = 0; 69 } 70} 71close IFCONFIG; 72die "Could not determine local IP address" if $local eq ""; 73 74# 75# Find the first remote host that responds to an icmp echo, 76# which isn't a local address. 77# 78open PING, "/sbin/ping -n -s 56 -c $MAXHOSTS $Broadcast{$local} |" or 79 die "Couldn't run ping: $!\n"; 80while (<PING>) { 81 if (/bytes from (.*): / and not defined $Broadcast{$1}) { 82 my $addr = $1; 83 84 if ($port != 0) { 85 # 86 # Test TCP 87 # 88 my $socket = IO::Socket::INET->new( 89 Type => SOCK_STREAM, 90 Proto => $proto, 91 PeerAddr => $addr, 92 PeerPort => $port, 93 Timeout => $TIMEOUT, 94 ); 95 next unless $socket; 96 close $socket; 97 } 98 99 $remote = $addr; 100 last; 101 } 102} 103close PING; 104die "Can't find a remote host for testing: No suitable response from " . 105 "$Broadcast{$local}\n" if $remote eq ""; 106 107print "$local $remote\n"; 108