#!/bin/bash
# Copyright (c) 2004-2005 Gentoo Foundation
# Distributed under the terms of the GNU General Public License v2

# Contributed by Roy Marples (uberlord@gentoo.org)

# char* arping_provides(void)
#
# Returns a string to change module definition for starting up
arping_provides() {
	echo "arping"
}

# void arping_depend(void)
#
# Sets up the dependancies for the module
arping_depend() {
	after system dhcp vlan
}

# bool arping_check_installed(void)
#
# Returns 0 if arping or arping2 is installed, otherwise 1
arping_check_installed() {
	[[ -x /sbin/arping || -x /usr/sbin/arping2 ]] && return 0
	if ${1:-false}; then
		eerror "For arping support emerge net-misc/iputils or net-analyzer/arping"
	fi
	return 1
}

# bool arping_check_depends(void)
#
# Checks to see if we have the needed functions
arping_check_depends() {
	local f

	for f in interface_exists interface_up ; do
		[[ $( type -t "${f}" ) == "function" ]] && continue
		eerror "arping: missing required function ${f}\n"
		return 1
	done

	return 0
}

# bool address_exists(char *interface, char *address)
#
# Returns 0 if the address on the interface responds to an arping
# 1 if not - packets defaults to 1
# If neither arping (net-misc/iputils) or arping2 (net-analyzer/arping)
# is installed then we return 1
address_exists() {
	local iface="$1" address="${2%%/*}" i

	# We only handle IPv4 addresses
	[[ ${address} != *.*.*.* ]] && return 1

	# 0.0.0.0 isn't a valid address - and some lusers have configured this
	[[ ${address} == "0.0.0.0" || ${address} == "0" ]] && return 1

	# We need to bring the interface up to test
	interface_up "${iface}"

	if [[ -x /sbin/arping ]]; then
		/sbin/arping -q -c 2 -w 3 -D -f -I "${iface}" "${address}" \
		&>/dev/null || return 0
	elif [[ -x /usr/sbin/arping2 ]]; then
		for (( i=0; i<3; i++ )); do
			/usr/sbin/arping2 -0 -c 1 -i "${iface}" "${address}" \
			&>/dev/null && return 0
		done
	fi
	return 1
}

# bool arping_gateways(void)
#
# arpings a list of gateways
# If one is foung then apply it's configuration
arping_gateways() {
	local gateways x conf i
	
	eval gateways=\"\$\{arping_${ifvar}\}\"
	[[ -z ${gateways} ]] && return 1

	einfo "Pinging gateways on ${iface} for configuration"
	eindent

	for x in ${gateways}; do
		vebegin "${x}"
		if address_exists "${iface}" "${x}" ; then
			for i in ${x//./ } ; do
				if [[ ${#i} == "2" ]]; then
					conf="${conf}0${i}"
				elif [[ ${#i} == "1" ]]; then
					conf="${conf}00${i}"
				else
					conf="${conf}${i}"
				fi
			done
			veend 0
			eoutdent
			veinfo "Configuring ${iface} for ${x}"
			configure_variables "${iface}" "${conf}"
			return 0
		fi
		veend 1
	done

	eoutdent
	return 1
}

# bool arping_apipa(char *iface)
#
# Tries to locate an address in the 169.254.0.0 netmask 169.254.255.255 range
arping_apipa() {
	local iface="$1" i1 i2 addr i=0

	einfo "Searching for free addresses in 169.254.0.0/16"
	eindent

	while [[ ${i} -lt 64516 ]]; do
		(( i1=${RANDOM}%255 ))
		(( i2=${RANDOM}%255 ))

		addr="169.254.${i1}.${i2}"
		vebegin "${addr}/16"
		if ! address_exists "${iface}" "${addr}" ; then
			config[config_counter]="${addr}/16 broadcast 169.254.255.255"
			(( config_counter-- ))
			veend 0
			eoutdent
			return 0
		fi

		(( i++ ))
	done

	eerror "No free address found!"
	eoutdent
	return 1
}

# bool arping_start(char *iface)
#
# Tries to detect a config based on arpinging things
arping_start() {
	local iface="$1"

	interface_exists "${iface}" true || return 1
	interface_up "${iface}"
	
	arping_gateways "${iface}" && return 0
	arping_apipa "${iface}" && return 0

	return 1
}

# vim:ts=4