#!/bin/sh

# Copyright (c) 2015 Rozhuk Ivan <rozhuk.im@gmail.com>
# All rights reserved.
# 
# Subject to the following obligations and disclaimer of warranty, use and
# redistribution of this software, in source or object code forms, with or
# without modifications are expressly permitted by Whistle Communications;
# provided, however, that:
# 1. Any and all reproductions of the source or object code must include the
#    copyright notice above and the following disclaimer of warranties; and
# 2. No rights are granted, in any manner or form, to use Whistle
#    Communications, Inc. trademarks, including the mark "WHISTLE
#    COMMUNICATIONS" on advertising, endorsements, or otherwise except as
#    such appears in the above copyright notice or in the software.
# 
# THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
# TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
# REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
# INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
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# WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
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# OF SUCH DAMAGE.
#
# Author: Rozhuk Ivan <rozhuk.im@gmail.com>
#


# This script creates LAGG interface using netgraph nodes.
# Roundrobin algo used.


# History
#
# Version: 1.0
# * initial release


usage_msg()
{
	echo "usage:"
	echo ""
	echo " Create new netgraph LAGG interface named \"NEW_NG_LAGG_IF_NAME\""
	echo "and add interfaces: \"ifname1\" \"ifname2\"..."
	echo "NEW_NG_LAGG_IF_NAME = \"auto\" - automatic generate names: \"ngeht0\", \"ngeth1\"..."
	echo "	start NEW_NG_LAGG_IF_NAME ifname1 ifname2..."
	echo "	start auto ifname1 ifname2..."
	echo ""
	echo " Destroy netgraph LAGG interface named \"NG_LAGG_IF_NAME\":"
	echo "	stop NG_LAGG_IF_NAME"
	echo ""
	echo " Add interface \"ifname\" to netgraph LAGG interface named \"NG_LAGG_IF_NAME\":"
	echo "	if_add NG_LAGG_IF_NAME ifname"
	echo ""
	echo " Remove interface \"ifname\" from netgraph LAGG interface:"
	echo "	if_del ifname"
}

case $1 in
start)
	# Load modules.
	kldload ng_ether > /dev/null 2>&1
	kldload ng_one2many > /dev/null 2>&1

	IF_NAME=$3
	# Check first network interface.
	if [ -z ${IF_NAME} ]; then
		echo "Network interface name required."
		usage_msg
		return 1
	fi
	if ! ifconfig ${IF_NAME} up > /dev/null 2>&1 ; then
		echo "Invalid network interface name: ${IF_NAME}."
		usage_msg
		return 1
	fi

	# Create and connect nodes fo first network interface.
	## Init network interface.
	ngctl msg ${IF_NAME}: setpromisc 1
	ngctl msg ${IF_NAME}: setautosrc 0

	## Nodes create.
	ngctl mkpeer ${IF_NAME}: one2many lower many0
	ngctl mkpeer ${IF_NAME}:lower eiface one ether
	NG_EIFACE_IF_NAME=`ngctl msg ${IF_NAME}:lower.one getifname | grep Args: | tail -c +8 | rev | tail -c +2 | rev`

	## Rename nodes and LAGG interface.
	if [ $2 = "auto" ]; then
		NG_LAGG_IF_NAME=${NG_EIFACE_IF_NAME}
	else
		NG_LAGG_IF_NAME=$2
		ngctl name "${IF_NAME}":lower.one "${NG_LAGG_IF_NAME}"
		ifconfig "${NG_EIFACE_IF_NAME}" name "${NG_LAGG_IF_NAME}"
	fi
	## Rename one2many node.
	ONE2MANY_NAME="${NG_LAGG_IF_NAME}-one2many"
	ngctl name "${IF_NAME}":lower "${ONE2MANY_NAME}"

	## Generate and set mac on LAGG interface.
	IF_NG_LAGG_MAC=`head -c 16 /dev/random | md5 | tail -c 11`
	ifconfig ${NG_LAGG_IF_NAME} link "00${IF_NG_LAGG_MAC}" down up

	## Add other network interfaces to LAGG.
	### many0 allready used, start from 1.
	HOOK_NUM=1
	### Start from second interface name / skeep first 3 args.
	shift 3

	while [ "$#" -gt 0 ];
	do
		CUR_ARG=$1
		### Move to next command line arg.
		shift 1
		if ! ifconfig ${CUR_ARG} up > /dev/null 2>&1 ; then
			echo "Invalid network interface name: ${CUR_ARG}."
		else
			## Init network interface and connect to LAGG.
			ngctl msg ${CUR_ARG}: setpromisc 1
			ngctl msg ${CUR_ARG}: setautosrc 0
			ngctl connect ${CUR_ARG}: ${ONE2MANY_NAME}: lower "many${HOOK_NUM}"
			let HOOK_NUM=HOOK_NUM+1 > /dev/null 2>&1
		fi
	done

	;;
stop)
	NG_LAGG_IF_NAME=$2
	# Check first network interface name.
	if [ -z ${NG_LAGG_IF_NAME} ]; then
		echo "LAGG interface name required."
		usage_msg
		return 1
	fi
	if ! ifconfig ${NG_LAGG_IF_NAME} > /dev/null 2>&1 ; then
		echo "Invalid LAGG interface name: ${NG_LAGG_IF_NAME}."
		usage_msg
		return 1
	fi
	ONE2MANY_NAME="${NG_LAGG_IF_NAME}-one2many"

	# Configure network interface to default settings.
	for i in $(jot - 0 64);
	do
		ngctl msg ${ONE2MANY_NAME}:"many$i" setautosrc 1 > /dev/null 2>&1
		ngctl msg ${ONE2MANY_NAME}:"many$i" setpromisc 0 > /dev/null 2>&1
	done

	# Remove hooks and nodes.
	ngctl shutdown ${ONE2MANY_NAME}:
	ngctl shutdown ${NG_LAGG_IF_NAME}:
	;;
if_add)
	NG_LAGG_IF_NAME=$2
	# Check LAGG network interface name.
	if [ -z ${NG_LAGG_IF_NAME} ]; then
		echo "LAGG interface name required."
		usage_msg
		return 1
	fi
	if ! ifconfig ${NG_LAGG_IF_NAME} > /dev/null 2>&1 ; then
		echo "Invalid LAGG interface name: ${NG_LAGG_IF_NAME}."
		usage_msg
		return 1
	fi

	IF_NAME=$3
	# Check network interface.
	if [ -z ${IF_NAME} ]; then
		echo "Network interface required."
		usage_msg
		return 1
	fi
	if ! ifconfig ${IF_NAME} up > /dev/null 2>&1 ; then
		echo "Invalid interface name: ${IF_NAME}."
		usage_msg
		return 1
	fi
	ONE2MANY_NAME="${NG_LAGG_IF_NAME}-one2many"

	# Configure network interface.
	ngctl msg ${IF_NAME}: setautosrc 1
	ngctl msg ${IF_NAME}: setpromisc 0
	for i in $(jot - 0 6);
	do
		if ngctl connect ${IF_NAME}: ${ONE2MANY_NAME}: lower "many$i" > /dev/null 2>&1 ; then
			# OK, added!
			return 0
		fi
	done
	echo "Add \"${IF_NAME}\" to \"${NG_LAGG_IF_NAME}\" FAIL: no more free links in LAGG (max 64) or \"${IF_NAME}\" allready connected."
	return 1
	;;
if_del)
	IF_NAME=$2
	# Check network interface.
	if [ -z ${IF_NAME} ]; then
		echo "Network interface name required."
		usage_msg
		return 1
	fi
	if ! ifconfig ${IF_NAME} up > /dev/null 2>&1 ; then
		echo "Invalid interface name: ${IF_NAME}."
		usage_msg
		return 1
	fi
	# configure net if
	ngctl msg ${IF_NAME}: setautosrc 1
	ngctl msg ${IF_NAME}: setpromisc 0
	# remove hooks and nodes
	ngctl rmhook ${IF_NAME}: lower
	# TODO: check is last iface removed and call stop.
	;;
*)
	echo "Unknown command: \"$1\""
	usage_msg
esac


return 0