. /lib/functions/network.sh

QNUM=200
TPPORT_HTTP=1188
TPPORT_HTTPS=1189
TPWS_USER=daemon

# max wait time for the link local ipv6 on the LAN interface
LINKLOCAL_WAIT_SEC=5

[ -n "$ZAPRET_BASE" ] || ZAPRET_BASE=/opt/zapret
IPSET_CR=$ZAPRET_BASE/ipset/create_ipset.sh

exists()
{
 which $1 >/dev/null 2>/dev/null
}

# can be multiple ipv6 outgoing interfaces
# uplink from isp, tunnelbroker, vpn, ...
# want them all. who knows what's the real one that blocks sites
# dont want any manual configuration - want to do it automatically
# standard network_find_wan[6] return only the first
# we use low level function from network.sh to avoid this limitation
# it can change theoretically and stop working

network_find_wan_all()
{
 __network_ifstatus "$1" "" "[@.route[@.target='0.0.0.0' && !@.table]].interface" "" 10 2>/dev/null && return
 network_find_wan $1
}
network_find_wan6_all()
{
 __network_ifstatus "$1" "" "[@.route[@.target='::' && !@.table]].interface" "" 10 2>/dev/null && return
 network_find_wan6 $1
}

ipt()
{
 iptables -C $@ 2>/dev/null || iptables -I $@
}
ipt6()
{
 ip6tables -C $@ 2>/dev/null || ip6tables -I $@
}

# there's no route_localnet for ipv6
# the best we can is to route to link local of the incoming interface
# OUTPUT - can DNAT to ::1
# PREROUTING - can't DNAT to ::1. can DNAT to link local of -i interface or to any global addr
# not a good idea to expose tpws to the world (bind to ::)

get_ipv6_linklocal()
{
 # $1 - interface name. if empty - any interface
 if exists ip ; then
    local dev
    [ -n "$1" ] && dev="dev $1"
    ip addr show $dev | sed -e 's/^.*inet6 \([^ ]*\)\/[0-9]* scope link.*$/\1/;t;d' | head -n 1
 else
    ifconfig $1 | sed -re 's/^.*inet6 addr: ([^ ]*)\/[0-9]* Scope:Link.*$/\1/;t;d' | head -n 1
 fi
}
get_ipv6_global()
{
 # $1 - interface name. if empty - any interface
 if exists ip ; then
    local dev
    [ -n "$1" ] && dev="dev $1"
    ip addr show $dev | sed -e 's/^.*inet6 \([^ ]*\)\/[0-9]* scope global.*$/\1/;t;d' | head -n 1
 else
    ifconfig $1 | sed -re 's/^.*inet6 addr: ([^ ]*)\/[0-9]* Scope:Global.*$/\1/;t;d' | head -n 1
 fi
}

dnat6_target()
{
 # get target ip address for DNAT. prefer link locals
 # tpws should be as inaccessible from outside as possible
 # link local address can appear not immediately after ifup
 
 # DNAT6_TARGET=- means attempt was made but address was not found (to avoid multiple re-attempts)
 [ "$DNAT6_TARGET" = '-' ] || {
    # no reason to query if its down
    network_is_up lan || return

    local DEVICE
    network_get_device DEVICE lan

    local ct=0
    while 
      DNAT6_TARGET=$(get_ipv6_linklocal $DEVICE)
      [ -n "$DNAT6_TARGET" ] && break
      [ "$ct" -ge "$LINKLOCAL_WAIT_SEC" ] && break
      echo waiting for the link local for another $(($LINKLOCAL_WAIT_SEC - $ct)) seconds ...
      ct=$(($ct+1))
      sleep 1
    do :; done

    [ -n "$DNAT6_TARGET" ] || {
      echo no link local. getting global
      DNAT6_TARGET=$(get_ipv6_global $DEVICE)
      [ -n "$DNAT6_TARGET" ] || {
        echo could not get any address
        DNAT6_TARGET=-
      }
    }
 }
}


fw_nfqws()
{
 local DEVICE wan_iface
 network_find_wan_all wan_iface
 for ext_iface in $wan_iface; do
    network_get_device DEVICE $ext_iface
    ipt POSTROUTING -t mangle -o $DEVICE $IPT_FILTER_POST -j NFQUEUE --queue-num $QNUM --queue-bypass
    ipt PREROUTING -t raw -i $DEVICE $IPT_FILTER_PRE -j NFQUEUE --queue-num $QNUM --queue-bypass
 done
}
fw_nfqws6()
{
 local DEVICE wan_iface
 network_find_wan6_all wan_iface
 for ext_iface in $wan_iface; do
    network_get_device DEVICE $ext_iface
    ipt6 POSTROUTING -t mangle -o $DEVICE $IPT_FILTER_POST -j NFQUEUE --queue-num $QNUM --queue-bypass
    ipt6 PREROUTING -t raw -i $DEVICE $IPT_FILTER_PRE -j NFQUEUE --queue-num $QNUM --queue-bypass
 done
}

IPT_OWNER="-m owner ! --uid-owner $TPWS_USER"
__fw_tpws()
{
 # $1 - use https
 local DEVICE wan_iface
 network_find_wan_all wan_iface
 for ext_iface in $wan_iface; do
    network_get_device DEVICE $ext_iface
    ipt OUTPUT -t nat -o $DEVICE $IPT_OWNER $IPT_FILTER_HTTP -j DNAT --to 127.0.0.1:$TPPORT_HTTP
    [ "$1" != "1" ] || ipt OUTPUT -t nat -o $DEVICE $IPT_OWNER $IPT_FILTER_HTTPS -j DNAT --to 127.0.0.1:$TPPORT_HTTPS
 done
 network_get_device DEVICE lan
 sysctl -w net.ipv4.conf.$DEVICE.route_localnet=1
 ipt prerouting_lan_rule -t nat $IPT_FILTER_HTTP -j DNAT --to 127.0.0.1:$TPPORT_HTTP
 [ "$1" != "1" ] || ipt prerouting_lan_rule -t nat $IPT_FILTER_HTTPS -j DNAT --to 127.0.0.1:$TPPORT_HTTPS
}
fw_tpws()
{
 __fw_tpws 0
}
fw_tpws_https()
{
 __fw_tpws 1
}

__fw_tpws6()
{
 # $1 - use https
 local DEVICE wan_iface ip6
 network_find_wan6_all wan_iface
 for ext_iface in $wan_iface; do
    network_get_device DEVICE $ext_iface
    ipt6 OUTPUT -t nat -o $DEVICE $IPT_OWNER $IPT_FILTER_HTTP -j DNAT --to [::1]:$TPPORT_HTTP
    [ "$1" != "1" ] || ipt6 OUTPUT -t nat -o $DEVICE $IPT_OWNER $IPT_FILTER_HTTPS -j DNAT --to [::1]:$TPPORT_HTTPS
 done
 network_get_device DEVICE lan
 dnat6_target
 [ "$DNAT6_TARGET" != '-' ] && {
    ipt6 PREROUTING -t nat -i $DEVICE $IPT_FILTER_HTTP -j DNAT --to [$DNAT6_TARGET]:$TPPORT_HTTP
    [ "$1" != "1" ] || ipt6 PREROUTING -t nat -i $DEVICE $IPT_FILTER_HTTPS -j DNAT --to [$DNAT6_TARGET]:$TPPORT_HTTPS
 }
}
fw_tpws6()
{
 __fw_tpws6 0
}
fw_tpws_https6()
{
 __fw_tpws6 1
}



create_ipset()
{
 echo "Creating ipset"
 "$IPSET_CR" $1
}