#!/usr/bin/env perl

=head1 DESCRIPTION

This is a SNMP extend for FreeBSD NFS server stats for use with LibreNMS.

For more information, see L<https://docs.librenms.org/#Extensions/Applications/#fbsd-nfs-client>.

=head1 SWITCHES

=head2 -p

Pretty print the JSON.

=head1 SNMPD SETUP EXAMPLES

Below is a basic example of setting it up snmpd.conf for NetSNMP.

    extend fbsdnfsclient /etc/snmp/fbsdnfsclient

=cut

#Copyright (c) 2018, Zane C. Bowers-Hadley
#All rights reserved.
#
#Redistribution and use in source and binary forms, with or without modification,
#are permitted provided that the following conditions are met:
#
#   * Redistributions of source code must retain the above copyright notice,
#    this list of conditions and the following disclaimer.
#   * Redistributions in binary form must reproduce the above copyright notice,
#    this list of conditions and the following disclaimer in the documentation
#    and/or other materials provided with the distribution.
#
#THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
#ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
#WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
#IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
#INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
#BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
#DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
#LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
#OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
#THE POSSIBILITY OF SUCH DAMAGE.

use strict;
use warnings;
use Getopt::Std;
use JSON;

#the version of returned data
my $VERSION=1;

#gets the options
my %opts=();
getopts('p', \%opts);

$Getopt::Std::STANDARD_HELP_VERSION = 1;
sub main::VERSION_MESSAGE {
	print "fbsdnfsclient SNMP extend 0.0.0\n";
}

sub main::HELP_MESSAGE {
	print "\n".
		"-p   Print the JSON in a pretty manner.\n";
	exit 0;
}

#the data to return
my %to_return;
$to_return{'version'}=$VERSION;
$to_return{'error'}='0';
$to_return{'errorString'}='';

my $nfsstatOutput=`/usr/bin/nfsstat`;
$to_return{error}=$?;

# check for bad exit codes
if ( $? == -1){
	$to_return{errorString}='failed to run nfsstat';
}
elsif ($? & 127) {
	$to_return{errorString}= sprintf "nfsstat died with signal %d, %s coredump\n",
		($? & 127),  ($? & 128) ? 'with' : 'without';
} else {
	$to_return{error}=$? >> 8;
	$to_return{errorString}="nfsstat exited with ".$to_return{error};
}

# pull the output of nfssetat appart
my %data;
my @nfsstatOutputA=split( /\n/, $nfsstatOutput );
my $int=0;
while( defined( $nfsstatOutputA[$int] ) ){
	$nfsstatOutputA[$int]=~s/^ +//;
	$nfsstatOutputA[$int]=~s/ +/ /g;

	if ( $int == 3 ){
		(
		 $data{Getattr},
		 $data{Setattr},
		 $data{Lookup},
		 $data{Readlink},
		 $data{Read},
		 $data{Write},
		 $data{Create},
		 $data{Remove},
		)=split( /\ /, $nfsstatOutputA[$int] );
	
	}

	if ( $int == 5 ){
		(
		 $data{Rename},
		 $data{Link},
		 $data{Symlink},
		 $data{Mkdir},
		 $data{Rmdir},
		 $data{Readdir},
		 $data{RdirPlus},
		 $data{Access},
		)=split( /\ /, $nfsstatOutputA[$int] );
	
	}

	if ( $int == 7 ){
		(
		 $data{Mknod},
		 $data{Fsstat},
		 $data{Fsinfo},
		 $data{PathConf},
		 $data{Commit},
		)=split( /\ /, $nfsstatOutputA[$int] );
	
	}

	if ( $int == 10 ){
		(
		 $data{TimedOut},
		 $data{Invalid},
		 $data{XReplies},
		 $data{Retries},
		 $data{Requests},
		)=split( /\ /, $nfsstatOutputA[$int] );
	
	}

	if ( $int == 13 ){
		(
		 $data{AttrHits},
		 $data{AttrMisses},
		 $data{LkupHits},
		 $data{LkupMisses},
		 $data{BioRHits},
		 $data{BioRMisses},
		 $data{BioWHits},
		 $data{BioWMisses},
		)=split( /\ /, $nfsstatOutputA[$int] );
	
	}

	if ( $int == 15 ){
		(
		 $data{BioRLHits},
		 $data{BioRLMisses},
		 $data{BioDHits},
		 $data{BioDMisses},
		 $data{DirEHits},
		 $data{DirEMisses},
		 $data{AccsHits},
		 $data{AccsMisses},
		)=split( /\ /, $nfsstatOutputA[$int] );
	
	}
	
	$int++;
}

#add the data has to the return hash
$to_return{data}=\%data;

#finally render the JSON
my $j=JSON->new;
if ( $opts{p} ){
        $j->pretty(1);
}
print $j->encode( \%to_return );
if ( ! $opts{p} ){
	print "\n";
}