#     This program is under GPL [http://www.gnu.org/licenses/old-licenses/gpl-2.0.txt]
#
#     (c) 1999-2009 - Tom Eastep (teastep@shorewall.net)
#
#	Options are:
#
#	    -n				  Don't alter Routing
#	    -v and -q			  Standard Shorewall Verbosity control
#
#	Commands are:
#
#	   start			  Starts the firewall
#          refresh                        Refresh the firewall
#	   restart			  Restarts the firewall
#	   reload			  Reload the firewall
#	   clear			  Removes all firewall rules
#	   stop				  Stops the firewall
#	   status			  Displays firewall status
#	   version			  Displays the version of Shorewall that
#	   				  generated this program
#
################################################################################
# Functions imported from /usr/share/shorewall/prog.header6
################################################################################
#
# Message to stderr
#
error_message() # $* = Error Message
{
   echo "   $@" >&2
}

#
# Conditionally produce message
#
progress_message() # $* = Message
{
    local timestamp
    timestamp=

    if [ $VERBOSE -gt 1 ]; then
	[ -n "$TIMESTAMP" ] && timestamp="$(date +%H:%M:%S) "
	echo "${timestamp}$@"
    fi

    if [ $LOG_VERBOSE -gt 1 ]; then
        timestamp="$(date +'%b %_d %T') "
        echo "${timestamp}$@" >> $STARTUP_LOG
    fi
}

progress_message2() # $* = Message
{
    local timestamp
    timestamp=

    if [ $VERBOSE -gt 0 ]; then
	[ -n "$TIMESTAMP" ] && timestamp="$(date +%H:%M:%S) "
	echo "${timestamp}$@"
    fi

    if [ $LOG_VERBOSE -gt 0 ]; then
        timestamp="$(date +'%b %_d %T') "
        echo "${timestamp}$@" >> $STARTUP_LOG
    fi
}

progress_message3() # $* = Message
{
    local timestamp
    timestamp=

    if [ $VERBOSE -ge 0 ]; then
	[ -n "$TIMESTAMP" ] && timestamp="$(date +%H:%M:%S) "
	echo "${timestamp}$@"
    fi

    if [ $LOG_VERBOSE -ge 0 ]; then
        timestamp="$(date +'%b %_d %T') "
        echo "${timestamp}$@" >> $STARTUP_LOG
    fi
}

#
# Split a colon-separated list into a space-separated list
#
split() {
    local ifs
    ifs=$IFS
    IFS=:
    echo $*
    IFS=$ifs
}

#
# Undo the effect of 'split()'
#
join()
{
    local f
    local o
    o=

    for f in $* ; do
        o="${o:+$o:}$f"
    done

    echo $o
}

#
# Return the number of elements in a list
#
list_count() # $* = list
{
    return $#
}

#
# Search a list looking for a match -- returns zero if a match found
# 1 otherwise
#
list_search() # $1 = element to search for , $2-$n = list
{
    local e
    e=$1

    while [ $# -gt 1 ]; do
	shift
	[ "x$e" = "x$1" ] && return 0
    done

    return 1
}

#
# Suppress all output for a command
#
qt()
{
    "$@" >/dev/null 2>&1
}

qt1()
{
    local status

    while [ 1 ]; do
	"$@" >/dev/null 2>&1
	status=$?
	[ $status -ne 4 ] && return $status
    done
}

#
# Determine if Shorewall is "running"
#
shorewall6_is_started() {
    qt1 $IP6TABLES -L shorewall -n
}

#
# Echos the fully-qualified name of the calling shell program
#
my_pathname() {
    cd $(dirname $0)
    echo $PWD/$(basename $0)
}

#
# Source a user exit file if it exists
#
run_user_exit() # $1 = file name
{
    local user_exit
    user_exit=$(find_file $1)

    if [ -f $user_exit ]; then
	progress_message "Processing $user_exit ..."
	. $user_exit
    fi
}

#
# Set a standard chain's policy
#
setpolicy() # $1 = name of chain, $2 = policy
{
    run_iptables -P $1 $2
}

#
# Set a standard chain to enable established and related connections
#
setcontinue() # $1 = name of chain
{
    run_iptables -A $1 -m state --state ESTABLISHED,RELATED -j ACCEPT
}

#
# Flush one of the Mangle table chains
#
flushmangle() # $1 = name of chain
{
    run_iptables -t mangle -F $1
}

#
# Flush and delete all user-defined chains in the filter table
#
deleteallchains() {
    run_iptables -F
    run_iptables -X
}

#
# Load a Kernel Module -- assumes that the variable 'moduledirectories' contains
#                         a space-separated list of directories to search for
#                         the module and that 'moduleloader' contains the
#                         module loader command.
#
loadmodule() # $1 = module name, $2 - * arguments
{
    local modulename
    modulename=$1
    local modulefile
    local suffix

    if ! list_search $modulename $DONT_LOAD $MODULES; then
	shift

	for suffix in $MODULE_SUFFIX ; do
	    for directory in $moduledirectories; do
		modulefile=$directory/${modulename}.${suffix}

		if [ -f $modulefile ]; then
		    case $moduleloader in
			insmod)
			    insmod $modulefile $*
			    ;;
			*)
			    modprobe $modulename $*
			    ;;
		    esac
		    break 2
		fi
	    done
	done
    fi
}

#
# Reload the Modules
#
reload_kernel_modules() {

    local save_modules_dir
    save_modules_dir=$MODULESDIR
    local directory
    local moduledirectories
    moduledirectories=
    local moduleloader
    moduleloader=modprobe

    if ! qt mywhich modprobe; then
	moduleloader=insmod
    fi

    [ -n "${MODULE_SUFFIX:=o gz ko o.gz ko.gz}" ]

    [ -z "$MODULESDIR" ] && MODULESDIR=/lib/modules/$(uname -r)/kernel/net/ipv6/netfilter:/lib/modules/$(uname -r)/kernel/net/netfilter
    MODULES=$(lsmod | cut -d ' ' -f1)

    for directory in $(split $MODULESDIR); do
	[ -d $directory ] && moduledirectories="$moduledirectories $directory"
    done

    [ -n "$moduledirectories" ] && while read command; do
	eval $command
    done

    MODULESDIR=$save_modules_dir
}

#
# Load kernel modules required for Shorewall6
#
load_kernel_modules() # $1 = Yes, if we are to save moduleinfo in $VARDIR
{
    local save_modules_dir
    save_modules_dir=$MODULESDIR
    local directory
    local moduledirectories
    moduledirectories=
    local moduleloader
    moduleloader=modprobe
    local savemoduleinfo
    savemoduleinfo=${1:-Yes} # So old compiled scripts still work

    if ! qt mywhich modprobe; then
	moduleloader=insmod
    fi

    [ -n "${MODULE_SUFFIX:=o gz ko o.gz ko.gz}" ]

    [ -z "$MODULESDIR" ] && \
	MODULESDIR=/lib/modules/$(uname -r)/kernel/net/ipv6/netfilter:/lib/modules/$(uname -r)/kernel/net/netfilter

    for directory in $(split $MODULESDIR); do
	[ -d $directory ] && moduledirectories="$moduledirectories $directory"
    done

    modules=$(find_file modules)

    if [ -f $modules -a -n "$moduledirectories" ]; then
	MODULES=$(lsmod | cut -d ' ' -f1)
	progress_message "Loading Modules..."
	. $modules
	if [ $savemoduleinfo = Yes ]; then
	    [ -d ${VARDIR} ] || mkdir -p ${VARDIR}
	    echo MODULESDIR="$MODULESDIR" > ${VARDIR}/.modulesdir
	    cp -f $modules ${VARDIR}/.modules
	fi
    elif [ $savemoduleinfo = Yes ]; then
	[ -d ${VARDIR} ] || mkdir -p ${VARDIR}
	> ${VARDIR}/.modulesdir
	> ${VARDIR}/.modules
    fi

    MODULESDIR=$save_modules_dir
}

#
# Query NetFilter about the existence of a filter chain
#
chain_exists() # $1 = chain name
{
    qt1 $IP6TABLES -L $1 -n
}

#
# Find the value 'dev' in the passed arguments then echo the next value
#

find_device() {
    while [ $# -gt 1 ]; do
	[ "x$1" = xdev ] && echo $2 && return
	shift
    done
}

#
# Find the value 'via' in the passed arguments then echo the next value
#

find_gateway() {
    while [ $# -gt 1 ]; do
	[ "x$1" = xvia ] && echo $2 && return
	shift
    done
}

#
# Find the value 'mtu' in the passed arguments then echo the next value
#

find_mtu() {
    while [ $# -gt 1 ]; do
	[ "x$1" = xmtu ] && echo $2 && return
	shift
    done
}

#
# Find the value 'peer' in the passed arguments then echo the next value up to
# "/"
#

find_peer() {
    while [ $# -gt 1 ]; do
	[ "x$1" = xpeer ] && echo ${2%/*} && return
	shift
    done
}

#
# Try to find the gateway through an interface looking for 'nexthop'

find_nexthop() # $1 = interface
{
    echo $(find_gateway `$IP -6 route list | grep "[[:space:]]nexthop.* $1"`)
}

#
# Find the default route's interface
#
find_default_interface() {
    $IP -6 route list | while read first rest; do
	[ "$first" = default ] && echo $(find_device $rest) && return
    done
}

#
# Find the interface with the passed MAC address
#

find_interface_by_mac() {
    local mac
    mac=$1
    local first
    local second
    local rest
    local dev

    $IP link list | while read first second rest; do
	case $first in
	    *:)
                dev=$second
		;;
	    *)
	        if [ "$second" = $mac ]; then
		    echo ${dev%:}
		    return
		fi
	esac
    done
}

#
# Determine if Interface is up
#
interface_is_up() {
    [ -n "$($IP link list dev $1 2> /dev/null | grep -e '[<,]UP[,>]')" ]
}

#
# Find interface address--returns the first IP address assigned to the passed
# device
#
find_first_interface_address() # $1 = interface
{
    #
    # get the line of output containing the first IP address
    #
    addr=$($IP -f inet6 addr show $1 2> /dev/null | grep 'inet6 .* global' | head -n1)
    #
    # If there wasn't one, bail out now
    #
    [ -n "$addr" ] || startup_error "Can't determine the IPv6 address of $1"
    #
    # Strip off the trailing VLSM mask (or the peer IP in case of a P-t-P link)
    # along with everything else on the line
    #
    echo $addr | sed 's/\s*inet6 //;s/\/.*//;s/ peer.*//'
}

find_first_interface_address_if_any() # $1 = interface
{
    #
    # get the line of output containing the first IP address
    #
    addr=$($IP -f inet6 addr show $1 2> /dev/null | grep 'inet6 2.* global' | head -n1)
    #
    # Strip off the trailing VLSM mask (or the peer IP in case of a P-t-P link)
    # along with everything else on the line
    #
    [ -n "$addr" ] && echo $addr | sed 's/\s*inet6 //;s/\/.*//;s/ peer.*//' || echo ::
}

#
# Determine if interface is usable from a Netfilter prespective
#
interface_is_usable() # $1 = interface
{
    interface_is_up $1 && [ "$(find_first_interface_address_if_any $1)" != :: ] && run_isusable_exit $1
}

#
# Find interface addresses--returns the set of addresses assigned to the passed
# device
#
find_interface_addresses() # $1 = interface
{
    $IP -f inet6 addr show $1 2> /dev/null | grep 'inet6 2' | sed 's/\s*inet6 //;s/\/.*//;s/ peer.*//'
}

#
# Get all interface addresses with VLSMs
#

find_interface_full_addresses() # $1 = interface
{
    $IP -f inet6 addr show $1 2> /dev/null | grep 'inet6 ' | sed 's/\s*inet6 //;s/ scope.*//;s/ peer.*//'
}

#
#  echo the list of networks routed out of a given interface
#
get_routed_networks() # $1 = interface name, $2-n = Fatal error message
{
    local address
    local rest

    $IP -6 route show dev $1 2> /dev/null |
	while read address rest; do
	    case "$address" in
		default)
		    if [ $# -gt 1 ]; then
			shift
			fatal_error "$@"
		    else
			echo "WARNING: default route ignored on interface $1" >&2
		    fi
		    ;;
		multicast|broadcast|prohibit|nat|throw|nexthop)
		    ;;
		2*)
		    [ "$address" = "${address%/*}" ] && address="${address}/128"
		    echo $address
		    ;;
	    esac
        done
}

#
# Normalize an IPv6 Address by compressing out consecutive zero elements
#
normalize_address() # $1 = valid IPv6 Address
{
    local address
    address=$1
    local j

    while true; do
	case $address in
	    ::*)
		address=0$address
		;;
	    *::*)
		list_count $(split $address)

		j=$?

		if [ $j -eq 7 ]; then
		    address=${address%::*}:0:${address#*::}
		elif [ $j -eq 8 ]; then
		    $address=${address%::*}:${address#*::}
		    break 2
		else
		    address=${address%::*}:0::${address#*::}
		fi
		;;
	    *)
		echo $address
		break 2
		;;
	esac
    done
}

#
# Reads correctly-formed and fully-qualified host and subnet addresses from STDIN. For each
# that defines a /120 or larger network, it sends to STDOUT:
#
#    The corresponding subnet-router anycast address (all host address bits are zero)
#    The corresponding anycast addresses defined by RFC 2526 (the last 128 addresses in the subnet)
#
convert_to_anycast() {
    local address
    local badress
    local vlsm
    local host
    local o
    local m
    m=
    local z
    z=65535
    local l

    while read address; do
	case $address in 
	    2*|3*)
		vlsm=${address#*/}
		vlsm=${vlsm:=128}

		if [ $vlsm -le 120 ]; then
	            #
	            # Defines a viable subnet -- first get the subnet-router anycast address
	            #
		    host=$((128 - $vlsm))

		    address=$(normalize_address ${address%/*})

		    while [ $host -ge 16 ]; do
			address=${address%:*}
			host=$(($host - 16))
		    done

		    if [ $host -gt 0 ]; then
			#
			# VLSM is not a multiple of 16
			#
			host=$((16 - $host))
			o=$((0x${address##*:}))
			m=0
			while [ $host -gt 0 ]; do
			    m=$((($m >> 1) | 0x8000))
			    z=$(($z >> 1))
			    host=$(($host - 1))
			done

			o=$(($o & $m))

			badress=${address%:*}

			address=$badress:$(printf %04x $o)

			z=$(($o | $z))

			if [ $vlsm -gt 112 ]; then
			    z=$(($z & 0xff80))
			fi

			badress=$badress:$(printf %04x $z)
		    else
			badress=$address
		    fi
		    #
		    # Note: at this point $address and $badress are the same except possibly for 
		    #       the contents of the last half-word
		    #
		    list_count $(split $address)

		    l=$?
		    #
		    # Now generate the anycast addresses defined by RFC 2526
		    #
		    if [ $l -lt 8 ]; then
			#
			# The subnet-router address
			#
			echo $address::

		    	while [ $l -lt 8 ]; do
			    badress=$badress:ffff
			    l=$(($l + 1 ))
			done
		    else
			#
			# The subnet-router address
			#
			echo $address
		    fi
		    #
		    # And the RFC 2526 addresses
		    #
		    echo $badress/121
		fi
		;;
	esac
    done
}

#
# Generate a list of anycast addresses for a given interface
# 

get_interface_acasts() # $1 = interface
{
    local addresses
    addresses=

    find_interface_full_addresses $1 | convert_to_anycast | sort -u
}

#
# Get a list of all configured anycast addresses on the system
#
get_all_acasts()
{
    find_interface_full_addresses | convert_to_anycast | sort -u
}

#
# Internal version of 'which'
#
mywhich() {
    local dir

    for dir in $(split $PATH); do
	if [ -x $dir/$1 ]; then
	    echo $dir/$1
	    return 0
	fi
    done

    return 2
}

#
# Find a File -- For relative file name, look in each ${CONFIG_PATH} then ${CONFDIR}
#
find_file()
{
    local saveifs
    saveifs=
    local directory

    case $1 in
	/*)
	    echo $1
	    ;;
	*)
	    for directory in $(split $CONFIG_PATH); do
		if [ -f $directory/$1 ]; then
		    echo $directory/$1
		    return
		fi
	    done

	    echo ${CONFDIR}/$1
	    ;;
    esac
}

#
# Set the Shorewall state
#
set_state () # $1 = state
{
    echo "$1 ($(date))" > ${VARDIR}/state
}

#
# Perform variable substitution on the passed argument and echo the result
#
expand() # $@ = contents of variable which may be the name of another variable
{
    eval echo \"$@\"
}

#
# Function for including one file into another
#
INCLUDE() {
    . $(find_file $(expand $@))
}

#
# Detect the gateway through an interface
#
detect_gateway() # $1 = interface
{
    local interface
    interface=$1
    #
    # First assume that this is some sort of point-to-point interface
    #
    gateway=$( find_peer $($IP -6 addr list $interface ) )
    #
    # Maybe there's a default route through this gateway already
    #
    [ -n "$gateway" ] || gateway=$(find_gateway $($IP -6 route list dev $interface | grep '^default'))
    #
    # Last hope -- is there a load-balancing route through the interface?
    #
    [ -n "$gateway" ] || gateway=$(find_nexthop $interface)
    #
    # Be sure we found one
    #
    [ -n "$gateway" ] && echo $gateway
}

# Function to truncate a string -- It uses 'cut -b -<n>'
# rather than ${v:first:last} because light-weight shells like ash and
# dash do not support that form of expansion.
#

truncate() # $1 = length
{
    cut -b -${1}
}

#
# Clear the current traffic shaping configuration
#

delete_tc1()
{
    clear_one_tc() {
        $TC qdisc del dev $1 root 2> /dev/null
        $TC qdisc del dev $1 ingress 2> /dev/null

    }

    run_tcclear_exit

    run_ip link list | \
    while read inx interface details; do
        case $inx in
            [0-9]*)
                clear_one_tc ${interface%:}
                ;;
            *)
                ;;
        esac
    done
}

#
# Detect a device's MTU -- echos the passed device's MTU
#
get_device_mtu() # $1 = device
{
    local output
    output="$($IP link list dev $1 2> /dev/null)" # quotes required for /bin/ash

    if [ -n "$output" ]; then
	echo $(find_mtu $output)
    else
	echo 1500
    fi
}

#
# Version of the above that doesn't generate any output for MTU 1500.
# Generates 'mtu <mtu+>' otherwise, where <mtu+> is the device's MTU + 100
#
get_device_mtu1() # $1 = device
{
    local output
    output="$($IP link list dev $1 2> /dev/null)" # quotes required for /bin/ash
    local mtu

    if [ -n "$output" ]; then
	mtu=$(find_mtu $output)
	if [ -n "$mtu" ]; then
	    [ $mtu = 1500 ] || echo mtu $(($mtu + 100))
	fi
    fi

}

#
# Undo changes to routing
#
undo_routing() {

    if [ -z "$NOROUTES"  ]; then
	#
	# Restore rt_tables database
	#
	if [ -f ${VARDIR}/rt_tables ]; then
	    [ -w /etc/iproute2/rt_table -a -z "$KEEP_RT_TABLES" ] && cp -f ${VARDIR}/rt_tables /etc/iproute2/ && progress_message "/etc/iproute2/rt_tables database restored"
	    rm -f ${VARDIR}/rt_tables
	fi
	#
	# Restore the rest of the routing table
	#
	if [ -f ${VARDIR}/undo_routing ]; then
	    . ${VARDIR}/undo_routing
	    progress_message "Shorewall-generated routing tables and routing rules removed"
	    rm -f ${VARDIR}/undo_routing
	fi
    fi

}

#
# Restore the default route that was in place before the initial 'shorewall start'
#
restore_default_route() {
    if [ -z "$NOROUTES" -a -f ${VARDIR}/default_route ]; then
	local default_route
	default_route=
	local route
	local result
	result=1

	while read route ; do
	    case $route in
		default)
		    if [ -n "$default_route" ]; then
			case "$default_route" in
			    *metric*)
		                #
		                # Don't restore a route with a metric -- we only replace the one with metric == 0
		                #
				qt $IP -6 route delete default metric 0 && \
				    progress_message "Default Route with metric 0 deleted"
				;;
			    *)
				qt $IP -6 route replace $default_route && \
				    result=0 && \
				    progress_message "Default Route (${default_route# }) restored"
				;;
			esac

			break
		    fi

		    default_route="$default_route $route"
		    ;;
		*)
		    default_route="$default_route $route"
		    ;;
	    esac
	done < ${VARDIR}/default_route

	rm -f ${VARDIR}/default_route
    fi

    return $result
}

#
# Determine how to do "echo -e"
#

find_echo() {
    local result

    result=$(echo "a\tb")
    [ ${#result} -eq 3 ] && { echo echo; return; }

    result=$(echo -e "a\tb")
    [ ${#result} -eq 3 ] && { echo "echo -e"; return; }

    result=$(which echo)
    [ -n "$result" ] && { echo "$result -e"; return; }

    echo echo
}

#
# Flush the conntrack table if $PURGE is non-empty
#
conditionally_flush_conntrack() {

    if [ -n "$PURGE" ]; then
	if [ -n $(which conntrack) ]; then
            conntrack -F
	else
            error_message "WARNING: The '-p' option requires the conntrack utility which does not appear to be installed on this system"
	fi
    fi
}

################################################################################
# End of functions imported from /usr/share/shorewall/prog.header6
################################################################################
