#! /usr/bin/perl
# Wrapper around the base Linux ping command to provide
#  nicer API (ie no flag arguments)
#
# **** License ****
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License version 2 as
# published by the Free Software Foundation.
#
# This program is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
# General Public License for more details.
#
# This code was originally developed by Vyatta, Inc.
# Portions created by Vyatta are Copyright (C) 2012 Vyatta, Inc.
# All Rights Reserved.
#
#
# Syntax
#   ping HOST
#           [ audible ]
#           [ adaptive ]
#           [ allow-broadcast]
#           [ count REQUESTS ]
#           [ mark N ]
#           [ flow LABEL ]
#           [ flood ]
#           [ interval ]
#           [ pattern PATTERN ]
#           [ timestamp ]
#           [ tos VALUE ]
#           [ quiet ]
#           [ bypass-routing ]
#           [ size SIZE ]
#           [ ttl TTL ]
#           [ verbose ]

use strict;
use warnings;
use NetAddr::IP;
use feature ":5.10";

sub get_options {
   my ($opt, $args) = @_;
   my $prev = $$args[-2];
   my $arg = $$args[-1];
   # print type text for arguments 
   if ( exists($opt->{$arg}) && $opt->{$arg}->{type} ne "noarg" ){
     get_args($opt, $arg);
   }
   # only show options that we haven't used yet
   my $options = '';
   foreach my $key (keys(%{$opt})){
     next if (grep $_ eq $key, @{$args});
     $options .= "$key ";
   }
   print $options;
   exit 0;
} 

sub get_args {
  my ($opt, $arg) = @_;
  print $opt->{$arg}->{type}; 
  exit 0; 
}

# Table for translating options to arguments
my %options = (
    'audible'	      => { 'p_arg'=>'a',  
                           'type'=>'noarg', 
                           'help'=>'Make a noise on ping' },
    'adaptive'	      => { 'p_arg'=>'A',  
                           'type'=>'noarg', 
                           'help'=>'Adativly set interpacket interval' },
    'allow-broadcast' => { 'p_arg'=>'b',  
                           'type'=>'noarg', 
                           'help'=>'Ping broadcast address' },
    'bypass-route'    => { 'p_arg'=>'r',  
                           'type'=>'noarg', 
                           'help'=>'Bypass normal routing tables' },
    'count'           => { 'p_arg'=>'c:', 
                           'type'=>'<requests>', 
                           'help'=>'Number of requests to send' },
    'deadline'        => { 'p_arg'=>'w:', 
                           'type'=>'<seconds>', 
                           'help'=>'Number of seconds before ping exits' },
    'flood'	      => { 'p_arg'=>'f',  
                           'type'=>'noarg', 
                            'help'=>'Send 100 requests per second' } ,
    'interface'       => { 'p_arg'=>'I:', 
                           'type'=>'<interface> <X.X.X.X> <h:h:h:h:h:h:h:h>', 
                           'help'=>'Interface to use as source for ping' }, 
    'interval'        => { 'p_arg'=>'i:', 
                           'type'=>'<seconds>',
                           'help'=>'Number of seconds to wait between requests' },
    'mark'	      => { 'p_arg'=>'m:', 
                           'type'=>'<fwmark>', 
                           'help'=>'Mark request for special processing' },
    'numeric'         => { 'p_arg'=>'n', 
                           'type'=>'noarg', 
                           'help'=>'Do not resolve DNS names' },
    'no-loopback'     => { 'p_arg'=>'L', 
                           'type'=>'noarg', 
                           'help'=>'Supress loopback of multicast pings' },
    'pattern'         => { 'p_arg'=>'p:', 
                           'type'=>'<pattern>', 
                           'help'=>'Pattern to fill out the packet' },
    'timestamp'       => { 'p_arg'=>'D', 
                           'type'=>'noarg', 
                           'help'=>'Print timestamp of output' },
    'tos'	      => { 'p_arg'=>'Q:', 
                           'type'=>'<tos>', 
                           'help'=>'Mark packets with specified TOS' },
    'quiet'	      => { 'p_arg'=>'q', 
                           'type'=>'noarg', 
                           'help'=>'Only print summary lines' },
    'record-route'    => { 'p_arg'=>'R',  
                           'type'=>'noarg', 
                           'help'=>'Record route the packet takes' },
    'size'	      => { 'p_arg'=>'s:',
                           'type'=>'<bytes>', 
                           'help'=>'Number of bytes to send' },
    'ttl'	      => { 'p_arg'=>'t:', 
                           'type'=>'<ttl>', 
                           'help'=>'Maximum packet lifetime' },
    'verbose'	      => { 'p_arg'=>'v',  
                           'type'=>'noarg', 
                           'help'=>'Verbose output' }
);



# First argument is host
my $host = shift @ARGV;
die "ping: Missing host\n"
    unless defined($host);
if ($host eq "--get-options"){
  my @args = @ARGV;
  get_options(\%options, \@args);
}
my $ip = new NetAddr::IP $host;
die "ping: Unknown host: $host\n"
    unless defined($ip);

my $cmd;
given ($ip->version) {
    when (4) {	$cmd = '/bin/ping'; }
    when (6) {	$cmd = '/bin/ping6' }
    default {
	die "Unknown address: $host\n";
    }
}

my @cmdargs = ( 'ping' );

while (my $arg = shift @ARGV) {
    my $pingarg = $options{$arg}->{p_arg};
    die "ping: unknown option $arg\n"
	unless $pingarg;
    
    my $flag = "-" . substr($pingarg, 0, 1);
    push @cmdargs, $flag;

    if (rindex($pingarg, ':') != -1) {
        my $optarg = shift @ARGV;
	die "ping: missing argument for $arg option\n"
	    unless defined($optarg);
	push @cmdargs, $optarg;
    }
}
exec { $cmd } @cmdargs, $host;