#!/bin/sh
#
#     This program is under GPL [http://www.gnu.org/licenses/old-licenses/gpl-2.0.txt]
#
#     (c) 1999-2010- Tom Eastep (teastep@shorewall.net)
#
#	Options are:
#
#	    -n				  Don't alter Routing
#	    -v and -q			  Standard Shorewall Verbosity control
#           -t                            Timestamp progress messages
#           -p                            Purge conntrack table
#           -r                            Recover from failed start/restart
#           -V <verbosity>                Set verbosity level explicitly
#           -R <restore>                  Overrides RESTOREFILE setting
#
#	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
################################################################################
#
# Conditionally produce message
#
progress_message() # $* = Message
{
    local timestamp
    timestamp=

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

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

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

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

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

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

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

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

#
# Generate a list of all network interfaces on the system
#
find_all_interfaces() {
    ${IP:-ip} link list | egrep '^[[:digit:]]+:' | cut -d ' ' -f2 | sed 's/:$//'    
}

#
# 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
}

#
# Determine if Interface is up
#
interface_is_up() {
    [ -n "$($IP -6 link list dev $1 2> /dev/null | grep -e '[<,]UP[,>]')" ]
}

#
# Determine if interface is usable from a Netfilter prespective
#
interface_is_usable() # $1 = interface
{
    [ "$1" = lo ] && return 0
    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
}

#
# 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
}

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 "$g_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 "$g_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 $g_purge is non-empty
#
conditionally_flush_conntrack() {

    if [ -n "$g_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
}

#
# Remove all Shorewall-added rules
#
clear_firewall() {
    stop_firewall

    setpolicy INPUT ACCEPT
    setpolicy FORWARD ACCEPT
    setpolicy OUTPUT ACCEPT

    run_iptables -F

    echo 1 > /proc/sys/net/ipv6/conf/all/forwarding

    run_clear_exit

    set_state "Cleared"

    logger -p kern.info "$g_product Cleared"
}

#
# Issue a message and stop/restore the firewall
#
fatal_error()
{
    echo "   ERROR: $@" >&2

    if [ $LOG_VERBOSITY -gt 1 ]; then
        timestamp="$(date +'%_b %d %T') "
        echo "${timestamp}  ERROR: $@" >> $STARTUP_LOG
    fi

    stop_firewall
    [ -n "$TEMPFILE" ] && rm -f $TEMPFILE
    exit 2
}

#
# Issue a message and stop
#
startup_error() # $* = Error Message
{
    echo "   ERROR: $@: Firewall state not changed" >&2

    if [ $LOG_VERBOSITY -ge 0 ]; then
        timestamp="$(date +'%_b %d %T') "
        echo "${timestamp}  ERROR: $@" >> $STARTUP_LOG
    fi

    case $COMMAND in
        start)
	    logger -p kern.err "ERROR:$g_product start failed:Firewall state not changed"
	    ;;
	restart)
	    logger -p kern.err "ERROR:$g_product restart failed:Firewall state not changed"
	    ;;
	restore)
	    logger -p kern.err "ERROR:$g_product restore failed:Firewall state not changed"
	    ;;
    esac

    if [ $LOG_VERBOSITY -gt 1 ]; then
        timestamp="$(date +'%_b %d %T') "

	case $COMMAND in
	    start)
		echo "${timestamp}  ERROR:$g_product start failed:Firewall state not changed" >> $STARTUP_LOG
		;;
	    restart)
		echo "${timestamp}  ERROR:$g_product restart failed:Firewall state not changed" >> $STARTUP_LOG
		;;
	    restore)
		echo "${timestamp}  ERROR:$g_product restore failed:Firewall state not changed" >> $STARTUP_LOG
		;;
	esac
    fi

    kill $$
    exit 2
}

#
# Run iptables and if an error occurs, stop/restore the firewall
#
run_iptables()
{
    local status

    while [ 1 ]; do
	$IP6TABLES $@
	status=$?
	[ $status -ne 4 ] && break
    done

    if [ $status -ne 0 ]; then
        error_message "ERROR: Command \"$IP6TABLES $@\" Failed"
	stop_firewall
        exit 2
    fi
}

#
# Run iptables retrying exit status 4
#
do_iptables()
{
    local status

    while [ 1 ]; do
	$IP6TABLES $@
	status=$?
	[ $status -ne 4 ] && return $status;
    done
}

#
# Run iptables and if an error occurs, stop/restore the firewall
#
run_ip()
{
    if ! $IP -6 $@; then
	error_message "ERROR: Command \"$IP -6 $@\" Failed"
	stop_firewall
	exit 2
    fi
}

#
# Run tc and if an error occurs, stop/restore the firewall
#
run_tc() {
    if ! $TC $@ ; then
	error_message "ERROR: Command \"$TC $@\" Failed"
	stop_firewall
	exit 2
    fi
}

#
# Restore the rules generated by 'drop','reject','logdrop', etc.
#
restore_dynamic_rules() {
    if [ -f ${VARDIR}/save ]; then
	progress_message2 "Setting up dynamic rules..."
	rangematch='source IP range'
	while read target ignore1 ignore2 address ignore3 rest; do
	    case $target in
		DROP|reject|logdrop|logreject)
		    case $rest in
			$rangematch*)
			    run_iptables -A dynamic -m iprange --src-range ${rest#source IP range} -j $target
			    ;;
			*)
			    if [ -z "$rest" ]; then
				run_iptables -A dynamic -s $address -j $target
			    else
				error_message "WARNING: Unable to restore dynamic rule \"$target $ignore1 $ignore2 $address $ignore3 $rest\""
			    fi
			    ;;
		    esac
		    ;;
	    esac
	done < ${VARDIR}/save
    fi
}

#
# Run the .iptables_restore_input as a set of discrete iptables commands
#
debug_restore_input() {
    local first second rest table chain
    #
    # Clear the ruleset
    #
    qt1 $IP6TABLES -t mangle -F
    qt1 $IP6TABLES -t mangle -X

    for chain in PREROUTING INPUT FORWARD POSTROUTING; do
	qt1 $IP6TABLES -t mangle -P $chain ACCEPT
    done

    qt1 $IP6TABLES -t raw    -F
    qt1 $IP6TABLES -t raw    -X

    for chain in PREROUTING OUTPUT; do
	qt1 $IP6TABLES -t raw -P $chain ACCEPT
    done

    qt1 $IP6TABLES -t filter -F
    qt1 $IP6TABLES -t filter -X

    for chain in INPUT FORWARD OUTPUT; do
	qt1 $IP6TABLES -t filter -P $chain -P ACCEPT
    done

    while read first second rest; do
	case $first in
	    -*)
		#
		# We can't call run_iptables() here because the rules may contain quoted strings
		#
		eval $IP6TABLES -t $table $first $second $rest

		if [ $? -ne 0 ]; then
		    error_message "ERROR: Command \"$IP6TABLES $first $second $rest\" Failed"
		    stop_firewall
		    exit 2
		fi
		;;
	    :*)
		chain=${first#:}

		if [ "x$second" = x- ]; then
		    do_iptables -t $table -N $chain
		else
		    do_iptables -t $table -P $chain $second
		fi

		if [ $? -ne 0 ]; then
		    error_message "ERROR: Command \"$IP6TABLES $first $second $rest\" Failed"
		    stop_firewall
		    exit 2
		fi
		;;
	    #
	    # This grotesque hack with the table names works around a bug/feature with ash
	    #
	    '*'raw)
		table=raw
		;;
	    '*'mangle)
		table=mangle
		;;
	    '*'nat)
		table=nat
		;;
	    '*'filter)
		table=filter
		;;
	esac
    done
}

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