#!/usr/bin/perl -w
#***********************************************************************
#** Written to make making the same configuration changes to a number **
#** of devices less of a pain in the ass. Written with CISCO Routers  **
#** and switches in mind it should work with any devices that can be  **
#** sent commands via telnet.                                         **
#***********************************************************************



use strict;
my ($script, $i, $telnetpid);
unless ( @ARGV >= 2 ) { die "usage: $0 script ip ... " }#Test to verify that the
re is the minimum number of arguments
$script = $ARGV[0];     #Take the first argument as the name of the file to pull
 commands from
shift;                  #Remove the first argument from the list of arguments

#Feeding a list of IPs
if ( $ARGV[0] eq '-l' ){ #If the new first argument is -l we know to look for a
list of IPs
        if ( $ARGV[1] ){ #Make sure there is a list specified on the command lin
e
                open(IPLIST, $ARGV[1]) || die "can't open $ARGV[1]\n";
                while(<IPLIST>){
                        feedip($script, $_);
                }
                close(IPLIST)
        } else { die "Need to supply a list of IPs when using $ARGV[0] \n"; }
}
#Feeding IPs from the command line
else {
        foreach $i (@ARGV ) {
                feedip($script, $i);
        }
}
#***************************************************************
#**             Subroutines below here                        **
#***************************************************************
#This subroutine is based heavily on code mooched from "Learning Perl" by Randal
l Schwartz and Tom Christainsen

sub telnet {
        use IO::Socket;
        my ($host, $port, $kidpid, $handle, $line);
        unless (@_ == 2) { die "usage: $0 host port" }
        $host = $_[0];
        $port = $_[1];
        #creates a tcp connection to the specified host and port
        $handle = IO::Socket::INET->new(Proto => "tcp",
                PeerAddr => $host,
                PeerPort => $port)
                or die "can't connect to port $port on $host: $!";
        $handle->autoflush(1); # so output gets there right away
        print STDERR "[Connected to $host:$port]\n";
        # split the program into two processes
        die "can't fork: $!" unless defined($kidpid = fork());
        #the if{} block runs only in the parent process
        if ($kidpid) {
                #copy the socket to standard output
                while (defined ($line = <$handle>)) {
                print STDOUT $line;
                }
                kill("TERM", $kidpid); #send SIGTERM to child
        }
        #the else{} block runs only in the child process
        else {
                # copy standard input to the socket
                while (defined ($line = <SCRIPT>)){
                print $handle $line;
                }
        }
}



sub feedip {
        my($p);
        use Net::Ping;
        $p = new Net::Ping("icmp");
        unless (@_ == 2) { die "usage: $0 host port" }
        if ($_[1] =~ m{\d+\.\d+\.\d+\.\d+}){       #Test to see if we were given
 an IP, invalid IPs can still slip through

                if ($p->ping($_[1])){ #Test to see that host is up
                        $p->close();
                        open(SCRIPT, $_[0]) || die "Cannot open $script\n";    #
Open the script file
                        #Fork a new process for the telnet subroutine, wait for
it to finish before returning
                        if (!defined($telnetpid = fork())) {

                                die "Cannot fork: $!";
                        } elsif ($telnetpid == 0) {

                                telnet($_[1], 23);         #Options being sent t
o sub telnet( IP, Port)
                                exit;
                        } else {

                                waitpid($telnetpid, 0);
                        }
                        close(SCRIPT) || die "Cannot close $script\n"; #Close th
e script file

                }
                else{
                        print "$_[1] does not appear to be responding, skipping.
\n";
                        $p->close();
                }
        }
        else {
                warn "$_[1] did not appear to be an IP address, skipping.\n ";
        }

}