#!/bin/ksh93

# Usage: see $0 -h

typeset -r VERSION='1.0' FPROG=${.sh.file} PROG=${FPROG##*/} SDIR=${FPROG%/*}

function showUsage {
	[[ -n $1 ]] && X='-?' ||  X='--man'
	getopts -a ${PROG} "${ print ${USAGE} ; }" OPT $X
}

function doMain {
	typeset AHOST="$1" CNAME="$2"
	[[ -z ${AHOST} ]] && showUsage 1 && return 1
	[[ -z ${CNAME} ]] && CNAME='public'
	
	typeset -l VAL
	typeset -A IGNORE
	typeset KEY X IP IDX

	# CISCO-VLAN-IFTABLE-RELATIONSHIP-MIB:
	cviRoutedVlanIfIndex='.1.3.6.1.4.1.9.9.128.1.1.1.1.3'
	# RFC1213-MIB:
	ipNetToMediaPhysAddress='.1.3.6.1.2.1.4.22.1.2'

	# -O
	#	X .. display table indexes in a more "program like" output
	#	s .. display the MIB obj name (+ any instance or other subidentifiers)
	#	q .. remove '=' and type info
	snmpbulkwalk -OqsX -v 2c -c ${CNAME} ${AHOST} ${cviRoutedVlanIfIndex} | \
	while read KEY VAL; do
		# don't wanna have the MACs of "routing" vlan switches
		IGNORE["@${VAL}"]=1
	done

	snmpbulkwalk -OqsX -v 2c -c ${CNAME} ${AHOST} ${ipNetToMediaPhysAddress} | \
	while read KEY VAL; do
		X=${KEY:24}				# rm leading 'ipNetToMediaPhysAddress['
		IP=${X:#*]}				# rm leading "${ifIdx}]" -> "[$ip]"
		X="${.sh.match}"		# re-use matched part
		IDX="@${X:0:${#X}-1}"	# rm trailing ']' from IfIdx
		[[ -n ${IGNORE["${IDX}"]} ]] && continue
		print "${VAL}\t${IP:1:${#IP}-2}"
	done
}

USAGE="[-?${VERSION}"' ]
[-copyright?Copyright (c) 2016 Jens Elkner. All rights reserved.]
[-license?CDDL 1.0]
[+NAME?'"${PROG}"' - collect arp data from a cisco machine via snmp]
[+DESCRIPTION?This script is more or less a simple wrapper around \bsnmpbulkwalk\b(1), which fetches the arp tables from a cisco machine with the IP or hostname \ahost\a using SNMPv2c to get and display pairings between ip and ethernet addresses on stdout. The \apw\a is the community string to use for SNMP transactions with this machine (Default: public).]
[+?This fetching of address mappings can be further automated by using a script
like /var/arpwatch/bihourly .] 
[h:help?Print this help and exit.]
[F:functions?Print a list of all functions available.]
[T:trace]:[functionList?A comma separated list of functions of this script to trace (convinience for troubleshooting).]
[+SEE ALSO?\bsnmpbulkwalk\b(1).]
\n\n\ahost\a [\apw\a]
'
TMP=
ERR_DIR=
EMAIL=
X="${ print ${USAGE} ; }"
while getopts "${X}" OPT ; do
	case ${OPT} in
		h) showUsage ; exit 0 ;;
		T)	if [[ ${OPTARG} == 'ALL' ]]; then
				typeset -ft ${ typeset +f ; }
			else
				typeset -ft ${OPTARG//,/ }
			fi
			;;
		F) typeset +f && exit 0 ;;
		*) showUsage 1 ; exit 1 ;;
	esac
done

X=$((OPTIND-1))
shift $X && OPTIND=1
unset X

doMain "$@"