lib.base

sharewall is very good

    done
}

#
# Netmask from CIDR
#
ip_netmask() {
    local vlsm
    vlsm=${1#*/}

    [ $vlsm -eq 0 ] && echo 0 || echo $(( -1 $LEFTSHIFT $(( 32 - $vlsm )) ))
}

#
# Network address from CIDR
#
ip_network() {
    local decodedaddr
    decodedaddr=$(decodeaddr ${1%/*})
    local netmask
    netmask=$(ip_netmask $1)

    echo $(encodeaddr $(($decodedaddr & $netmask)))
}

#
# The following hack is supplied to compensate for the fact that many of
# the popular light-weight Bourne shell derivatives don't support XOR ("^").
#
ip_broadcast() {
    local x
    x=$(( 32 - ${1#*/} ))

    [ $x -eq 32 ] && echo -1 || echo $(( $(( 1 $LEFTSHIFT $x )) - 1 ))
}

#
# Calculate broadcast address from CIDR
#
broadcastaddress() {
    local decodedaddr
    decodedaddr=$(decodeaddr ${1%/*})
    local netmask
    netmask=$(ip_netmask $1)
    local broadcast
    broadcast=$(ip_broadcast $1)

    echo $(encodeaddr $(( $(($decodedaddr & $netmask)) | $broadcast )))
}

#
# Test for network membership
#
in_network() # $1 = IP address, $2 = CIDR network
{
    local netmask
    netmask=$(ip_netmask $2)
    #
    # We compare the values as strings rather than integers to work around broken BusyBox ash on OpenWRT
    #
    test $(( $(decodeaddr $1) & $netmask)) = $(( $(decodeaddr ${2%/*}) & $netmask ))
}

#
# Netmask to VLSM
#
ip_vlsm() {
    local mask
    mask=$(decodeaddr $1)
    local vlsm
    vlsm=0
    local x
    x=$(( 128 << 24 )) # 0x80000000

    while [ $(( $x & $mask )) -ne 0 ]; do
	[ $mask -eq $x ] && mask=0 || mask=$(( $mask $LEFTSHIFT 1 )) # Not all shells shift 0x80000000 left properly.
	vlsm=$(($vlsm + 1))
    done

    if [ $(( $mask & 2147483647 )) -ne 0 ]; then # 2147483647 = 0x7fffffff
	echo "Invalid net mask: $1" >&2
    else
	echo $vlsm
    fi
}


#
# Chain name base for an interface -- replace all periods with underscores in the passed name.
#                                     The result is echoed (less trailing "+").
#
chain_base() #$1 = interface
{
    local c
    c=${1%%+}

    while true; do
	case $c in
	    @*)
               c=at_${c#@}
	       ;;               
	    *.*)
		c="${c%.*}_${c##*.}"
		;;
	    *-*)
		c="${c%-*}_${c##*-}"
		;;
	    *%*)
		c="${c%\%*}_${c##*%}"
		;;
	    *@*)
		c="${c%@*}_${c##*@}"
		;;
	    *)
		echo ${c:=common}
		return
		;;
	esac
    done
}

#
# Query NetFilter about the existence of a filter chain
#
chain_exists() # $1 = chain name
{
    qt $IPTABLES -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
}

#
# Find the interfaces that have a route to the passed address - the default
# route is not used.
#

find_rt_interface() {
    ip route list | while read addr rest; do
	case $addr in
	    */*)
		in_network ${1%/*} $addr && echo $(find_device $rest)
		;;
	    default)
		;;
	    *)
		if [ "$addr" = "$1" -o "$addr/32" = "$1" ]; then
		    echo $(find_device $rest)
		fi
		;;
	esac
    done
}

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

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

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

#
# Echo the name of the interface(s) that will be used to send to the
# passed address
#

find_interface_by_address() {
    local dev
    dev="$(find_rt_interface $1)"
    local first
    local rest

    [ -z "$dev" ] && dev=$(find_default_interface)

    [ -n "$dev" ] && echo $dev
}

#
# 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 inet addr show $1 2> /dev/null | grep 'inet .* global' | head -n1)
    #
    # If there wasn't one, bail out now
    #
    [ -n "$addr" ] || fatal_error "Can't determine the IP 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*inet //;s/\/.*//;s/ peer.*//'
}

find_first_interface_address_if_any() # $1 = interface
{
    #
    # get the line of output containing the first IP address
    #
    addr=$(ip -f inet addr show $1 2> /dev/null | grep 'inet .* global' | head -n1)
    #
    # Strip off the trailing VLSM mask (or the peer IP in case of a P-t-P link)
    # along with everything else on the line
    #
    [ -n "$addr" ] && echo $addr | sed 's/\s*inet //;s/\/.*//;s/ peer.*//' || echo 0.0.0.0
}

#
# 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)" != 0.0.0.0 ]
}

#
# Find interface addresses--returns the set of addresses assigned to the passed
# device
#
find_interface_addresses() # $1 = interface
{
    ip -f inet addr show $1 2> /dev/null | grep inet\  | sed 's/\s*inet //;s/\/.*//;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 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 $1" >&2
		    fi
		    ;;
		multicast|broadcast|prohibit|nat|throw|nexthop)
		    ;;
		*)
		    [ "$address" = "${address%/*}" ] && address="${address}/32"
		    echo $address
		    ;;
	    esac
        done
}

get_interface_bcasts() # $1 = interface
{
    ip -f inet addr show dev $1 2> /dev/null | grep 'inet.*brd' | sed 's/inet.*brd //; s/scope.*//;' | 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
}

#
# Set default config path
#
ensure_config_path() {
    local F
    F=${SHAREDIR}/configpath
    if [ -z "$CONFIG_PATH" ]; then
	[ -f $F ] || { echo "   ERROR: $F does not exist"; exit 2; }
	. $F
    fi

    if [ -n "$SHOREWALL_DIR" ]; then
	[ "${CONFIG_PATH%%:*}" = "$SHOREWALL_DIR" ] || CONFIG_PATH=$SHOREWALL_DIR:$CONFIG_PATH
    fi
}

#
# 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
}

#
# Get fully-qualified name of file
#
resolve_file() # $1 = file name
{
    local pwd
    pwd=$PWD

    case $1 in
	/*)
	    echo $1
	    ;;
	.)
	    echo $pwd
	    ;;
	./*)
	    echo ${pwd}${1#.}
	    ;;
	..)
	    cd ..
	    echo $PWD
	    cd $pwd
	    ;;
	../*)
	    cd ..
	    resolve_file ${1#../}
	    cd $pwd
	    ;;
	*)
	    echo $pwd/$1
	    ;;
    esac
}

#
# 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 $@))
}

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

#
# Determine which optional facilities are supported by iptables/netfilter
#
determine_capabilities() {
    qt $IPTABLES -t nat    -L -n && NAT_ENABLED=Yes    || NAT_ENABLED=
    qt $IPTABLES -t mangle -L -n && MANGLE_ENABLED=Yes || MANGLE_ENABLED=

    CONNTRACK_MATCH=
    NEW_CONNTRACK_MATCH=
    OLD_CONNTRACK_MATCH=
    MULTIPORT=
    XMULTIPORT=
    POLICY_MATCH=
    PHYSDEV_MATCH=
    PHYSDEV_BRIDGE=
    IPRANGE_MATCH=
    RECENT_MATCH=
    OWNER_MATCH=
    IPSET_MATCH=
    CONNMARK=
    XCONNMARK=
    CONNMARK_MATCH=
    XCONNMARK_MATCH=
    RAW_TABLE=
    IPP2P_MATCH=
    OLD_IPP2P_MATCH=
    LENGTH_MATCH=
    CLASSIFY_TARGET=
    ENHANCED_REJECT=
    USEPKTTYPE=
    KLUDGEFREE=
    MARK=
    XMARK=
    MANGLE_FORWARD=
    COMMENTS=
    ADDRTYPE=
    TCPMSS_MATCH=
    HASHLIMIT_MATCH=
    NFQUEUE_TARGET=
    REALM_MATCH=
    HELPER_MATCH=
    CONNLIMIT_MATCH=
    TIME_MATCH=
    GOTO_TARGET=

    chain=fooX$$

    [ -n "$IPTABLES" ] || IPTABLES=$(mywhich iptables)

    if [ -z "$IPTABLES" ]; then
	echo "   ERROR: No executable iptables binary can be found on your PATH" >&2
	exit 1
    fi

    qt $IPTABLES -F $chain
    qt $IPTABLES -X $chain
    if ! $IPTABLES -N $chain; then
	echo "   ERROR: The command \"$IPTABLES -N $chain\" failed" >&2
	exit 1
    fi

    chain1=${chain}1

    qt $IPTABLES -F $chain1
    qt $IPTABLES -X $chain1
    if ! $IPTABLES -N $chain1; then
	echo "   ERROR: The command \"$IPTABLES -N $chain1\" failed" >&2
	exit 1
    fi

    if ! qt $IPTABLES -A $chain -m state --state ESTABLISHED,RELATED -j ACCEPT; then
	echo "   ERROR: Your kernel lacks connection tracking and/or state matching -- Shorewall will not run on this system" >&2
	exit 1
    fi

    qt $IPTABLES -A $chain -m conntrack --ctorigdst 192.168.1.1 -j ACCEPT && CONNTRACK_MATCH=Yes

    if [ -n "$CONNTRACK_MATCH" ]; then
	qt $IPTABLES -A $chain -m conntrack -p tcp --ctorigdstport 22 -j ACCEPT && NEW_CONNTRACK_MATCH=Yes
	qt $IPTABLES -A $chain -m conntrack ! --ctorigdst 1.2.3.4 || OLD_CONNTRACK_MATCH=Yes
    fi

    if qt $IPTABLES -A $chain -p tcp -m multiport --dports 21,22 -j ACCEPT; then
	MULTIPORT=Yes
	qt $IPTABLES -A $chain -p tcp -m multiport --sports 60 -m multiport --dports 99 -j ACCEPT && KLUDEFREE=Yes
    fi

    qt $IPTABLES -A $chain -p tcp -m multiport --dports 21:22 -j ACCEPT           && XMULTIPORT=Yes
    qt $IPTABLES -A $chain -m policy --pol ipsec --mode tunnel --dir in -j ACCEPT && POLICY_MATCH=Yes

    if qt $IPTABLES -A $chain -m physdev --physdev-out eth0 -j ACCEPT; then
	PHYSDEV_MATCH=Yes
	qt $IPTABLES -A $chain -m physdev --physdev-is-bridged --physdev-in eth0 --physdev-out eth0 -j ACCEPT && PHYSDEV_BRIDGE=Yes
	if [ -z "${KLUDGEFREE}" ]; then
	    qt $IPTABLES -A $chain -m physdev --physdev-in eth0 -m physdev --physdev-out eth0 -j ACCEPT && KLUDGEFREE=Yes
	fi
    fi

    if qt $IPTABLES -A $chain -m iprange --src-range 192.168.1.5-192.168.1.124 -j ACCEPT; then
	IPRANGE_MATCH=Yes
	if [ -z "${KLUDGEFREE}" ]; then
	    qt $IPTABLES -A $chain -m iprange --src-range 192.168.1.5-192.168.1.124 -m iprange --dst-range 192.168.1.5-192.168.1.124 -j ACCEPT && KLUDGEFREE=Yes
	fi
    fi

    qt $IPTABLES -A $chain -m recent --update -j ACCEPT     && RECENT_MATCH=Yes
    qt $IPTABLES -A $chain -m owner --uid-owner 0 -j ACCEPT && OWNER_MATCH=Yes

    if qt $IPTABLES -A $chain -m connmark --mark 2  -j ACCEPT; then
	CONNMARK_MATCH=Yes
	qt $IPTABLES -A $chain -m connmark --mark 2/0xFF -j ACCEPT && XCONNMARK_MATCH=Yes
    fi

    qt $IPTABLES -A $chain -p tcp -m ipp2p --edk -j ACCEPT       && IPP2P_MATCH=Yes
    if [ -n "$IPP2P_MATCH" ]; then
	qt $IPTABLES -A $chain -p tcp -m ipp2p --ipp2p -j ACCEPT && OLD_IPP2P_MATCH=Yes
    fi

    qt $IPTABLES -A $chain -m length --length 10:20 -j ACCEPT           && LENGTH_MATCH=Yes
    qt $IPTABLES -A $chain -j REJECT --reject-with icmp-host-prohibited && ENHANCED_REJECT=Yes

    qt $IPTABLES -A $chain -j ACCEPT -m comment --comment "This is a comment" && COMMENTS=Yes