# -*- coding: utf-8 -*-
#
# Copyright (C) 2018 Red Hat, Inc.
#
# Authors:
# Eric Garver <e@erig.me>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
#
import copy
import json
import ipaddress

from firewall.core.logger import log
from firewall.functions import check_mac, getPortRange, normalizeIP6, \
                               check_single_address, check_address
from firewall.errors import FirewallError, UNKNOWN_ERROR, INVALID_RULE, \
                            INVALID_ICMPTYPE, INVALID_TYPE, INVALID_ENTRY, \
                            INVALID_PORT
from firewall.core.rich import Rich_Accept, Rich_Reject, Rich_Drop, Rich_Mark, \
                               Rich_Masquerade, Rich_ForwardPort, Rich_IcmpBlock, \
                               Rich_Tcp_Mss_Clamp, Rich_NFLog
from firewall.core.base import DEFAULT_ZONE_TARGET
from nftables.nftables import Nftables

TABLE_NAME = "firewalld"
TABLE_NAME_POLICY = TABLE_NAME + "_" + "policy_drop"
TABLE_NAME_PROBE = TABLE_NAME + "_" + "probe"
POLICY_CHAIN_PREFIX = "policy_"

# Map iptables (table, chain) to hooks and priorities.
# These are well defined by NF_IP_PRI_* defines in netfilter.
#
# This is analogous to ipXtables.BUILT_IN_CHAINS, but we omit the chains that
# are only used for direct rules.
#
# Note: All hooks use their standard position + NFT_HOOK_OFFSET. This means
# iptables will have DROP precedence. It also means that even if iptables
# ACCEPTs a packet it may still be dropped later by firewalld's rules.
#
NFT_HOOK_OFFSET = 10
IPTABLES_TO_NFT_HOOK = {
    #"security": {
    #    "INPUT": ("input", 50 + NFT_HOOK_OFFSET),
    #    "OUTPUT": ("output", 50 + NFT_HOOK_OFFSET),
    #    "FORWARD": ("forward", 50 + NFT_HOOK_OFFSET),
    #},
    "raw": {
        # "PREROUTING": ("prerouting", -300 + NFT_HOOK_OFFSET),
        # "OUTPUT": ("output", -300 + NFT_HOOK_OFFSET),
    },
    "mangle": {
        "PREROUTING": ("prerouting", -150 + NFT_HOOK_OFFSET),
        # "POSTROUTING": ("postrouting", -150 + NFT_HOOK_OFFSET),
        # "INPUT": ("input", -150 + NFT_HOOK_OFFSET),
        # "OUTPUT": ("output", -150 + NFT_HOOK_OFFSET),
        # "FORWARD": ("forward", -150 + NFT_HOOK_OFFSET),
    },
    "nat": {
        "PREROUTING": ("prerouting", -100 + NFT_HOOK_OFFSET),
        "POSTROUTING": ("postrouting", 100 + NFT_HOOK_OFFSET),
        # "INPUT": ("input", 100 + NFT_HOOK_OFFSET),
        "OUTPUT": ("output", -100 + NFT_HOOK_OFFSET),
    },
    "filter": {
        "PREROUTING": ("prerouting", 0 + NFT_HOOK_OFFSET),
        "INPUT": ("input", 0 + NFT_HOOK_OFFSET),
        "FORWARD": ("forward", 0 + NFT_HOOK_OFFSET),
        "OUTPUT": ("output", 0 + NFT_HOOK_OFFSET),
    },
}

def _icmp_types_fragments(protocol, type, code=None):
    fragments = [{"match": {"left": {"payload": {"protocol": protocol, "field": "type"}},
                            "op": "==",
                            "right": type}}]
    if code is not None:
        fragments.append({"match": {"left": {"payload": {"protocol": protocol, "field": "code"}},
                                    "op": "==",
                                    "right": code}})
    return fragments

# Most ICMP types are provided by nft, but for the codes we have to use numeric
# values.
#
ICMP_TYPES_FRAGMENTS = {
    "ipv4": {
        "communication-prohibited":     _icmp_types_fragments("icmp", "destination-unreachable", 13),
        "destination-unreachable":      _icmp_types_fragments("icmp", "destination-unreachable"),
        "echo-reply":                   _icmp_types_fragments("icmp", "echo-reply"),
        "echo-request":                 _icmp_types_fragments("icmp", "echo-request"),
        "fragmentation-needed":         _icmp_types_fragments("icmp", "destination-unreachable", 4),
        "host-precedence-violation":    _icmp_types_fragments("icmp", "destination-unreachable", 14),
        "host-prohibited":              _icmp_types_fragments("icmp", "destination-unreachable", 10),
        "host-redirect":                _icmp_types_fragments("icmp", "redirect", 1),
        "host-unknown":                 _icmp_types_fragments("icmp", "destination-unreachable", 7),
        "host-unreachable":             _icmp_types_fragments("icmp", "destination-unreachable", 1),
        "ip-header-bad":                _icmp_types_fragments("icmp", "parameter-problem", 1),
        "network-prohibited":           _icmp_types_fragments("icmp", "destination-unreachable", 8),
        "network-redirect":             _icmp_types_fragments("icmp", "redirect", 0),
        "network-unknown":              _icmp_types_fragments("icmp", "destination-unreachable", 6),
        "network-unreachable":          _icmp_types_fragments("icmp", "destination-unreachable", 0),
        "parameter-problem":            _icmp_types_fragments("icmp", "parameter-problem"),
        "port-unreachable":             _icmp_types_fragments("icmp", "destination-unreachable", 3),
        "precedence-cutoff":            _icmp_types_fragments("icmp", "destination-unreachable", 15),
        "protocol-unreachable":         _icmp_types_fragments("icmp", "destination-unreachable", 2),
        "redirect":                     _icmp_types_fragments("icmp", "redirect"),
        "required-option-missing":      _icmp_types_fragments("icmp", "parameter-problem", 1),
        "router-advertisement":         _icmp_types_fragments("icmp", "router-advertisement"),
        "router-solicitation":          _icmp_types_fragments("icmp", "router-solicitation"),
        "source-quench":                _icmp_types_fragments("icmp", "source-quench"),
        "source-route-failed":          _icmp_types_fragments("icmp", "destination-unreachable", 5),
        "time-exceeded":                _icmp_types_fragments("icmp", "time-exceeded"),
        "timestamp-reply":              _icmp_types_fragments("icmp", "timestamp-reply"),
        "timestamp-request":            _icmp_types_fragments("icmp", "timestamp-request"),
        "tos-host-redirect":            _icmp_types_fragments("icmp", "redirect", 3),
        "tos-host-unreachable":         _icmp_types_fragments("icmp", "destination-unreachable", 12),
        "tos-network-redirect":         _icmp_types_fragments("icmp", "redirect", 2),
        "tos-network-unreachable":      _icmp_types_fragments("icmp", "destination-unreachable", 11),
        "ttl-zero-during-reassembly":   _icmp_types_fragments("icmp", "time-exceeded", 1),
        "ttl-zero-during-transit":      _icmp_types_fragments("icmp", "time-exceeded", 0),
    },

    "ipv6": {
        "address-unreachable":          _icmp_types_fragments("icmpv6", "destination-unreachable", 3),
        "bad-header":                   _icmp_types_fragments("icmpv6", "parameter-problem", 0),
        "beyond-scope":                 _icmp_types_fragments("icmpv6", "destination-unreachable", 2),
        "communication-prohibited":     _icmp_types_fragments("icmpv6", "destination-unreachable", 1),
        "destination-unreachable":      _icmp_types_fragments("icmpv6", "destination-unreachable"),
        "echo-reply":                   _icmp_types_fragments("icmpv6", "echo-reply"),
        "echo-request":                 _icmp_types_fragments("icmpv6", "echo-request"),
        "failed-policy":                _icmp_types_fragments("icmpv6", "destination-unreachable", 5),
        "mld-listener-done":            _icmp_types_fragments("icmpv6", "mld-listener-done"),
        "mld-listener-query":           _icmp_types_fragments("icmpv6", "mld-listener-query"),
        "mld-listener-report":          _icmp_types_fragments("icmpv6", "mld-listener-report"),
        "mld2-listener-report":         _icmp_types_fragments("icmpv6", "mld2-listener-report"),
        "neighbour-advertisement":      _icmp_types_fragments("icmpv6", "nd-neighbor-advert"),
        "neighbour-solicitation":       _icmp_types_fragments("icmpv6", "nd-neighbor-solicit"),
        "no-route":                     _icmp_types_fragments("icmpv6", "destination-unreachable", 0),
        "packet-too-big":               _icmp_types_fragments("icmpv6", "packet-too-big"),
        "parameter-problem":            _icmp_types_fragments("icmpv6", "parameter-problem"),
        "port-unreachable":             _icmp_types_fragments("icmpv6", "destination-unreachable", 4),
        "redirect":                     _icmp_types_fragments("icmpv6", "nd-redirect"),
        "reject-route":                 _icmp_types_fragments("icmpv6", "destination-unreachable", 6),
        "router-advertisement":         _icmp_types_fragments("icmpv6", "nd-router-advert"),
        "router-solicitation":          _icmp_types_fragments("icmpv6", "nd-router-solicit"),
        "time-exceeded":                _icmp_types_fragments("icmpv6", "time-exceeded"),
        "ttl-zero-during-reassembly":   _icmp_types_fragments("icmpv6", "time-exceeded", 1),
        "ttl-zero-during-transit":      _icmp_types_fragments("icmpv6", "time-exceeded", 0),
        "unknown-header-type":          _icmp_types_fragments("icmpv6", "parameter-problem", 1),
        "unknown-option":               _icmp_types_fragments("icmpv6", "parameter-problem", 2),
    }
}

class nftables(object):
    name = "nftables"
    policies_supported = True

    def __init__(self, fw):
        self._fw = fw
        self.restore_command_exists = True
        self.supports_table_owner = False
        self.available_tables = []
        self.rule_to_handle = {}
        self.rule_ref_count = {}
        self.rich_rule_priority_counts = {}
        self.policy_priority_counts = {}
        self.zone_source_index_cache = {}

        self.nftables = Nftables()
        self.nftables.set_echo_output(True)
        self.nftables.set_handle_output(True)

    def _probe_support_table_owner(self):
        try:
            rules = {
                "nftables": [
                    {"metainfo": {"json_schema_version": 1}},
                    {
                        "add": {
                            "table": {
                                "family": "inet",
                                "name": TABLE_NAME_PROBE,
                                "flags": ["owner", "persist"],
                            }
                        }
                    },
                ]
            }

            rc, output, _ = self.nftables.json_cmd(rules)
            if rc:
                raise ValueError("nftables probe table owner failed")

            # old nftables versions would ignore table flags in JSON, so we
            # must parse back and verify the flags are set.
            rules = {
                "nftables": [
                    {"metainfo": {"json_schema_version": 1}},
                    {"list": {"table": {"family": "inet", "name": TABLE_NAME_PROBE}}},
                ]
            }
            self.nftables.set_echo_output(False)
            rc, output, _ = self.nftables.json_cmd(rules)
            self.nftables.set_echo_output(True)
            flags = output["nftables"][1]["table"]["flags"]

            self.set_rule(
                {"delete": {"table": {"family": "inet", "name": TABLE_NAME_PROBE}}},
                self._fw.get_log_denied(),
            )

            if "owner" not in flags or "persist" not in flags:
                raise ValueError("nftables probe table owner failed")

            log.debug2("nftables: probe_support(): owner flag is supported.")
            self.supports_table_owner = True
        except:
            log.debug2("nftables: probe_support(): owner flag is NOT supported.")
            self.supports_table_owner = False

    def probe_support(self):
        self._probe_support_table_owner()

    def _run_replace_zone_source(self, rule, zone_source_index_cache):
        for verb in ["add", "insert", "delete"]:
            if verb in rule:
                break

        if "%%ZONE_SOURCE%%" in rule[verb]["rule"]:
            zone_source = (rule[verb]["rule"]["%%ZONE_SOURCE%%"]["zone"],
                           rule[verb]["rule"]["%%ZONE_SOURCE%%"]["address"])
            del rule[verb]["rule"]["%%ZONE_SOURCE%%"]
        elif "%%ZONE_INTERFACE%%" in rule[verb]["rule"]:
            zone_source = None
            del rule[verb]["rule"]["%%ZONE_INTERFACE%%"]
        else:
            return

        family = rule[verb]["rule"]["family"]

        if zone_source and verb == "delete":
            if family in zone_source_index_cache and \
               zone_source in zone_source_index_cache[family]:
                zone_source_index_cache[family].remove(zone_source)
        elif verb != "delete":
            if family not in zone_source_index_cache:
                zone_source_index_cache[family] = []

            if zone_source:
                # order source based dispatch by zone name
                if zone_source not in zone_source_index_cache[family]:
                    zone_source_index_cache[family].append(zone_source)
                    zone_source_index_cache[family].sort(key=lambda x: x[0])

                index = zone_source_index_cache[family].index(zone_source)
            else:
                index = len(zone_source_index_cache[family])

            _verb_snippet = rule[verb]
            del rule[verb]
            if index == 0:
                rule["insert"] = _verb_snippet
            else:
                index -= 1 # point to the rule before insertion point
                rule["add"] = _verb_snippet
                rule["add"]["rule"]["index"] = index

    def reverse_rule(self, dict):
        if "insert" in dict:
            return {"delete": copy.deepcopy(dict["insert"])}
        elif "add" in dict:
            return {"delete": copy.deepcopy(dict["add"])}
        else:
            raise FirewallError(UNKNOWN_ERROR, "Failed to reverse rule")

    def _set_rule_replace_priority(self, rule, priority_counts, token):
        for verb in ["add", "insert", "delete"]:
            if verb in rule:
                break

        if token in rule[verb]["rule"]:
            priority = rule[verb]["rule"][token]
            del rule[verb]["rule"][token]
            if type(priority) != int:
                raise FirewallError(INVALID_RULE, "priority must be followed by a number")
            chain = (rule[verb]["rule"]["family"], rule[verb]["rule"]["chain"]) # family, chain
            # Add the rule to the priority counts. We don't need to store the
            # rule, just bump the ref count for the priority value.
            if verb == "delete":
                if chain not in priority_counts or \
                   priority not in priority_counts[chain] or \
                   priority_counts[chain][priority] <= 0:
                    raise FirewallError(UNKNOWN_ERROR, "nonexistent or underflow of priority count")

                priority_counts[chain][priority] -= 1
            else:
                if chain not in priority_counts:
                    priority_counts[chain] = {}
                if priority not in priority_counts[chain]:
                    priority_counts[chain][priority] = 0

                # calculate index of new rule
                index = 0
                for p in sorted(priority_counts[chain].keys()):
                    if p == priority and verb == "insert":
                        break
                    index += priority_counts[chain][p]
                    if p == priority and verb == "add":
                        break

                priority_counts[chain][priority] += 1

                _verb_snippet = rule[verb]
                del rule[verb]
                if index == 0:
                    rule["insert"] = _verb_snippet
                else:
                    index -= 1 # point to the rule before insertion point
                    rule["add"] = _verb_snippet
                    rule["add"]["rule"]["index"] = index

    def _get_rule_key(self, rule):
        for verb in ["add", "insert", "delete"]:
            if verb in rule and "rule" in rule[verb]:
                rule_key = copy.deepcopy(rule[verb]["rule"])
                for non_key in ["index", "handle", "position"]:
                    if non_key in rule_key:
                        del rule_key[non_key]
                # str(rule_key) is insufficient because dictionary order is
                # not stable.. so abuse the JSON library
                rule_key = json.dumps(rule_key, sort_keys=True)
                return rule_key
        # Not a rule (it's a table, chain, etc)
        return None

    def set_rules(self, rules, log_denied):
        _valid_verbs = ["add", "insert", "delete", "flush", "replace"]
        _valid_add_verbs = ["add", "insert", "replace"]
        _deduplicated_rules = []
        _executed_rules = []
        rich_rule_priority_counts = copy.deepcopy(self.rich_rule_priority_counts)
        policy_priority_counts = copy.deepcopy(self.policy_priority_counts)
        zone_source_index_cache = copy.deepcopy(self.zone_source_index_cache)
        rule_ref_count = self.rule_ref_count.copy()
        for rule in rules:
            if type(rule) != dict:
                raise FirewallError(UNKNOWN_ERROR, "rule must be a dictionary, rule: %s" % (rule))

            for verb in _valid_verbs:
                if verb in rule:
                    break
            if verb not in rule:
                raise FirewallError(INVALID_RULE, "no valid verb found, rule: %s" % (rule))

            rule_key = self._get_rule_key(rule)

            # rule deduplication
            if rule_key in rule_ref_count:
                log.debug2("%s: prev rule ref cnt %d, %s", self.__class__,
                           rule_ref_count[rule_key], rule_key)
                if verb != "delete":
                    rule_ref_count[rule_key] += 1
                    continue
                elif rule_ref_count[rule_key] > 1:
                    rule_ref_count[rule_key] -= 1
                    continue
                elif rule_ref_count[rule_key] == 1:
                    rule_ref_count[rule_key] -= 1
                else:
                    raise FirewallError(UNKNOWN_ERROR, "rule ref count bug: rule_key '%s', cnt %d"
                                                       % (rule_key, rule_ref_count[rule_key]))
            elif rule_key and verb != "delete":
                rule_ref_count[rule_key] = 1

            _deduplicated_rules.append(rule)

            _rule = copy.deepcopy(rule)
            if rule_key:
                # filter empty rule expressions. Rich rules add quite a bit of
                # them, but it makes the rest of the code simpler. libnftables
                # does not tolerate them.
                _rule[verb]["rule"]["expr"] = list(filter(None, _rule[verb]["rule"]["expr"]))

                self._set_rule_replace_priority(_rule, rich_rule_priority_counts, "%%RICH_RULE_PRIORITY%%")
                self._set_rule_replace_priority(_rule, policy_priority_counts, "%%POLICY_PRIORITY%%")
                self._run_replace_zone_source(_rule, zone_source_index_cache)

                # delete using rule handle
                if verb == "delete":
                    _rule = {"delete": {"rule": {"family": _rule["delete"]["rule"]["family"],
                                                 "table": _rule["delete"]["rule"]["table"],
                                                 "chain": _rule["delete"]["rule"]["chain"],
                                                 "handle": self.rule_to_handle[rule_key]}}}

            _executed_rules.append(_rule)

        json_blob = {"nftables": [{"metainfo": {"json_schema_version": 1}}] + _executed_rules}
        if log.getDebugLogLevel() >= 3:
            # guarded with if statement because json.dumps() is expensive.
            log.debug3("%s: calling python-nftables with JSON blob: %s", self.__class__,
                       json.dumps(json_blob))
        rc, output, error = self.nftables.json_cmd(json_blob)
        if rc != 0:
            raise ValueError("'%s' failed: %s\nJSON blob:\n%s" % ("python-nftables", error, json.dumps(json_blob)))

        self.rich_rule_priority_counts = rich_rule_priority_counts
        self.policy_priority_counts = policy_priority_counts
        self.zone_source_index_cache = zone_source_index_cache
        self.rule_ref_count = rule_ref_count

        index = 0
        for rule in _deduplicated_rules:
            index += 1 # +1 due to metainfo
            rule_key = self._get_rule_key(rule)

            if not rule_key:
                continue

            if "delete" in rule:
                del self.rule_to_handle[rule_key]
                del self.rule_ref_count[rule_key]
                continue

            for verb in _valid_add_verbs:
                if verb in output["nftables"][index]:
                    break
            if verb not in output["nftables"][index]:
                continue

            # don't bother tracking handles for the policy table as we simply
            # delete the entire table.
            if TABLE_NAME_POLICY == output["nftables"][index][verb]["rule"]["table"]:
                continue

            self.rule_to_handle[rule_key] = output["nftables"][index][verb]["rule"]["handle"]

    def set_rule(self, rule, log_denied):
        self.set_rules([rule], log_denied)
        return ""

    def get_available_tables(self, table=None):
        # Tables always exist in nftables
        return [table] if table else IPTABLES_TO_NFT_HOOK.keys()

    def _build_add_table_rules(self, table):
        rule = {"add": {"table": {"family": "inet", "name": table}}}

        if (
            table == TABLE_NAME
            and self._fw._nftables_table_owner
            and self.supports_table_owner
        ):
            rule["add"]["table"]["flags"] = ["owner", "persist"]

        return [rule]

    def _build_delete_table_rules(self, table):
        # To avoid nftables returning ENOENT we always add the table before
        # deleting to guarantee it will exist.
        #
        # In the future, this add+delete should be replaced with "destroy", but
        # that verb is too new to rely upon.
        return self._build_add_table_rules(table) + [
            {"delete": {"table": {"family": "inet", "name": table}}},
        ]

    def build_flush_rules(self):
        self.rule_to_handle = {}
        self.rule_ref_count = {}
        self.rich_rule_priority_counts = {}
        self.policy_priority_counts = {}
        self.zone_source_index_cache = {}

        return self._build_delete_table_rules(TABLE_NAME)

    def _build_set_policy_rules_ct_rule(self, enable, hook):
        add_del = { True: "add", False: "delete" }[enable]
        return {add_del: {"rule": {"family": "inet",
                                   "table": TABLE_NAME_POLICY,
                                   "chain": "%s_%s" % ("filter", hook),
                                   "expr": [{"match": {"left": {"ct": {"key": "state"}},
                                                       "op": "in",
                                                       "right": {"set": ["established", "related"]}}},
                                            {"accept": None}]}}}

    def build_set_policy_rules(self, policy, policy_details):
        # Policy is not exposed to the user. It's only to make sure we DROP
        # packets while reloading and for panic mode. As such, using hooks with
        # a higher priority than our base chains is sufficient.
        rules = []
        if policy == "PANIC":
            rules.extend(self._build_add_table_rules(TABLE_NAME_POLICY))

            # Use "raw" priority for panic mode. This occurs before
            # conntrack, mangle, nat, etc
            for hook in ["prerouting", "output"]:
                rules.append({"add": {"chain": {"family": "inet",
                                                "table": TABLE_NAME_POLICY,
                                                "name": "%s_%s" % ("raw", hook),
                                                "type": "filter",
                                                "hook": hook,
                                                "prio": -300 + NFT_HOOK_OFFSET - 1,
                                                "policy": "drop"}}})
        elif policy == "DROP":
            rules.extend(self._build_add_table_rules(TABLE_NAME_POLICY))

            # To drop everything except existing connections we use
            # "filter" because it occurs _after_ conntrack.
            for hook in ("INPUT", "FORWARD", "OUTPUT"):
                d_policy = policy_details[hook]
                assert d_policy in ("ACCEPT", "REJECT", "DROP")
                hook = hook.lower()
                chain_name = f"filter_{hook}"

                rules.append({"add": {"chain": {"family": "inet",
                                                "table": TABLE_NAME_POLICY,
                                                "name": chain_name,
                                                "type": "filter",
                                                "hook": hook,
                                                "prio": 0 + NFT_HOOK_OFFSET - 1,
                                                "policy": "drop"}}})

                rules.append(self._build_set_policy_rules_ct_rule(True, hook))

                if d_policy == "ACCEPT":
                    expr_fragment = {"accept": None}
                elif d_policy == "DROP":
                    expr_fragment = {"drop": None}
                else:
                    expr_fragment = {
                        "reject": {"type": "icmpx", "expr": "admin-prohibited"}
                    }

                rules.append(
                    {
                        "add": {
                            "rule": {
                                "family": "inet",
                                "table": TABLE_NAME_POLICY,
                                "chain": chain_name,
                                "expr": [expr_fragment],
                            }
                        }
                    }
                )
        elif policy == "ACCEPT":
            rules += self._build_delete_table_rules(TABLE_NAME_POLICY)
        else:
            raise FirewallError(UNKNOWN_ERROR, "not implemented")

        return rules

    def supported_icmp_types(self, ipv=None):
        # nftables supports any icmp_type via arbitrary type/code matching.
        # We just need a translation for it in ICMP_TYPES_FRAGMENTS.
        supported = set()

        for _ipv in [ipv] if ipv else ICMP_TYPES_FRAGMENTS.keys():
            supported.update(ICMP_TYPES_FRAGMENTS[_ipv].keys())

        return list(supported)

    def build_default_tables(self):
        return self._build_add_table_rules(TABLE_NAME)

    def build_default_rules(self, log_denied="off"):
        default_rules = []
        for chain in IPTABLES_TO_NFT_HOOK["mangle"].keys():
            default_rules.append({"add": {"chain": {"family": "inet",
                                                    "table": TABLE_NAME,
                                                    "name": "mangle_%s" % chain,
                                                    "type": "filter",
                                                    "hook": "%s" % IPTABLES_TO_NFT_HOOK["mangle"][chain][0],
                                                    "prio": IPTABLES_TO_NFT_HOOK["mangle"][chain][1]}}})
            for dispatch_suffix in ["POLICIES_pre", "ZONES", "POLICIES_post"]:
                default_rules.append({"add": {"chain": {"family": "inet",
                                                        "table": TABLE_NAME,
                                                        "name": "mangle_%s_%s" % (chain, dispatch_suffix)}}})
            for dispatch_suffix in ["ZONES"]:
                default_rules.append({"add": {"rule":  {"family": "inet",
                                                        "table": TABLE_NAME,
                                                        "chain": "mangle_%s" % chain,
                                                        "expr": [{"jump": {"target": "mangle_%s_%s" % (chain, dispatch_suffix)}}]}}})

        for chain in IPTABLES_TO_NFT_HOOK["nat"].keys():
            default_rules.append({"add": {"chain": {"family": "inet",
                                                    "table": TABLE_NAME,
                                                    "name": "nat_%s" % chain,
                                                    "type": "nat",
                                                    "hook": "%s" % IPTABLES_TO_NFT_HOOK["nat"][chain][0],
                                                    "prio": IPTABLES_TO_NFT_HOOK["nat"][chain][1]}}})

            if chain in ["OUTPUT"]:
                # nat, output does not have zone dispatch
                for dispatch_suffix in ["POLICIES_pre", "POLICIES_post"]:
                    default_rules.append({"add": {"chain": {"family": "inet",
                                                            "table": TABLE_NAME,
                                                            "name": "nat_%s_%s" % (chain, dispatch_suffix)}}})
                    default_rules.append({"add": {"rule":  {"family": "inet",
                                                            "table": TABLE_NAME,
                                                            "chain": "nat_%s" % chain,
                                                            "expr": [{"jump": {"target": "nat_%s_%s" % (chain, dispatch_suffix)}}]}}})
            else:
                for dispatch_suffix in ["POLICIES_pre", "ZONES", "POLICIES_post"]:
                    default_rules.append({"add": {"chain": {"family": "inet",
                                                            "table": TABLE_NAME,
                                                            "name": "nat_%s_%s" % (chain, dispatch_suffix)}}})
                for dispatch_suffix in ["ZONES"]:
                    default_rules.append({"add": {"rule":  {"family": "inet",
                                                            "table": TABLE_NAME,
                                                            "chain": "nat_%s" % chain,
                                                            "expr": [{"jump": {"target": "nat_%s_%s" % (chain, dispatch_suffix)}}]}}})

        for chain in IPTABLES_TO_NFT_HOOK["filter"].keys():
            default_rules.append({"add": {"chain": {"family": "inet",
                                                    "table": TABLE_NAME,
                                                    "name": "filter_%s" % chain,
                                                    "type": "filter",
                                                    "hook": "%s" % IPTABLES_TO_NFT_HOOK["filter"][chain][0],
                                                    "prio": IPTABLES_TO_NFT_HOOK["filter"][chain][1]}}})

        # filter, INPUT
        default_rules.append({"add": {"rule":  {"family": "inet",
                                                "table": TABLE_NAME,
                                                "chain": "filter_%s" % "INPUT",
                                                "expr": [{"match": {"left": {"ct": {"key": "state"}},
                                                                    "op": "in",
                                                                    "right": {"set": ["established", "related"]}}},
                                                         {"accept": None}]}}})
        default_rules.append({"add": {"rule":  {"family": "inet",
                                                "table": TABLE_NAME,
                                                "chain": "filter_%s" % "INPUT",
                                                "expr": [{"match": {"left": {"ct": {"key": "status"}},
                                                                    "op": "in",
                                                                    "right": "dnat"}},
                                                         {"accept": None}]}}})
        default_rules.append({"add": {"rule":  {"family": "inet",
                                                "table": TABLE_NAME,
                                                "chain": "filter_%s" % "INPUT",
                                                "expr": [{"match": {"left": {"meta": {"key": "iifname"}},
                                                                    "op": "==",
                                                                    "right": "lo"}},
                                                         {"accept": None}]}}})
        if log_denied != "off":
            default_rules.append({"add": {"rule":  {"family": "inet",
                                                    "table": TABLE_NAME,
                                                    "chain": "filter_%s" % "INPUT",
                                                    "expr": [{"match": {"left": {"ct": {"key": "state"}},
                                                                        "op": "in",
                                                                        "right": {"set": ["invalid"]}}},
                                                             self._pkttype_match_fragment(log_denied),
                                                             {"log": {"prefix": "STATE_INVALID_DROP: "}}]}}})
        default_rules.append({"add": {"rule":  {"family": "inet",
                                                "table": TABLE_NAME,
                                                "chain": "filter_%s" % "INPUT",
                                                "expr": [{"match": {"left": {"ct": {"key": "state"}},
                                                                    "op": "in",
                                                                    "right": {"set": ["invalid"]}}},
                                                         {"drop": None}]}}})
        for dispatch_suffix in ["POLICIES_pre", "ZONES", "POLICIES_post"]:
            default_rules.append({"add": {"chain": {"family": "inet",
                                                    "table": TABLE_NAME,
                                                    "name": "filter_%s_%s" % ("INPUT", dispatch_suffix)}}})
        for dispatch_suffix in ["ZONES"]:
            default_rules.append({"add": {"rule":  {"family": "inet",
                                                    "table": TABLE_NAME,
                                                    "chain": "filter_%s" % "INPUT",
                                                    "expr": [{"jump": {"target": "filter_%s_%s" % ("INPUT", dispatch_suffix)}}]}}})
        if log_denied != "off":
            default_rules.append({"add": {"rule":  {"family": "inet",
                                                    "table": TABLE_NAME,
                                                    "chain": "filter_%s" % "INPUT",
                                                    "expr": [self._pkttype_match_fragment(log_denied),
                                                             {"log": {"prefix": "FINAL_REJECT: "}}]}}})
        default_rules.append({"add": {"rule":  {"family": "inet",
                                                "table": TABLE_NAME,
                                                "chain": "filter_%s" % "INPUT",
                                                "expr": [{"reject": {"type": "icmpx", "expr": "admin-prohibited"}}]}}})

        # filter, FORWARD
        default_rules.append({"add": {"rule":  {"family": "inet",
                                                "table": TABLE_NAME,
                                                "chain": "filter_%s" % "FORWARD",
                                                "expr": [{"match": {"left": {"ct": {"key": "state"}},
                                                                    "op": "in",
                                                                    "right": {"set": ["established", "related"]}}},
                                                         {"accept": None}]}}})
        default_rules.append({"add": {"rule":  {"family": "inet",
                                                "table": TABLE_NAME,
                                                "chain": "filter_%s" % "FORWARD",
                                                "expr": [{"match": {"left": {"ct": {"key": "status"}},
                                                                    "op": "in",
                                                                    "right": "dnat"}},
                                                         {"accept": None}]}}})
        default_rules.append({"add": {"rule":  {"family": "inet",
                                                "table": TABLE_NAME,
                                                "chain": "filter_%s" % "FORWARD",
                                                "expr": [{"match": {"left": {"meta": {"key": "iifname"}},
                                                                    "op": "==",
                                                                    "right": "lo"}},
                                                         {"accept": None}]}}})
        if log_denied != "off":
            default_rules.append({"add": {"rule":  {"family": "inet",
                                                    "table": TABLE_NAME,
                                                    "chain": "filter_%s" % "FORWARD",
                                                    "expr": [{"match": {"left": {"ct": {"key": "state"}},
                                                                        "op": "in",
                                                                        "right": {"set": ["invalid"]}}},
                                                             self._pkttype_match_fragment(log_denied),
                                                             {"log": {"prefix": "STATE_INVALID_DROP: "}}]}}})
        default_rules.append({"add": {"rule":  {"family": "inet",
                                                "table": TABLE_NAME,
                                                "chain": "filter_%s" % "FORWARD",
                                                "expr": [{"match": {"left": {"ct": {"key": "state"}},
                                                                    "op": "in",
                                                                    "right": {"set": ["invalid"]}}},
                                                         {"drop": None}]}}})
        for dispatch_suffix in ["POLICIES_pre"]:
            default_rules.append({"add": {"chain": {"family": "inet",
                                                    "table": TABLE_NAME,
                                                    "name": "filter_%s_%s" % ("FORWARD", dispatch_suffix)}}})
        for dispatch_suffix in ["ZONES"]:
            default_rules.append({"add": {"chain": {"family": "inet",
                                                    "table": TABLE_NAME,
                                                    "name": "filter_%s_%s" % ("FORWARD", dispatch_suffix)}}})
            default_rules.append({"add": {"rule":  {"family": "inet",
                                                    "table": TABLE_NAME,
                                                    "chain": "filter_%s" % "FORWARD",
                                                    "expr": [{"jump": {"target": "filter_%s_%s" % ("FORWARD", dispatch_suffix)}}]}}})
        for dispatch_suffix in ["POLICIES_post"]:
            default_rules.append({"add": {"chain": {"family": "inet",
                                                    "table": TABLE_NAME,
                                                    "name": "filter_%s_%s" % ("FORWARD", dispatch_suffix)}}})
        if log_denied != "off":
            default_rules.append({"add": {"rule":  {"family": "inet",
                                                    "table": TABLE_NAME,
                                                    "chain": "filter_%s" % "FORWARD",
                                                    "expr": [self._pkttype_match_fragment(log_denied),
                                                             {"log": {"prefix": "FINAL_REJECT: "}}]}}})
        default_rules.append({"add": {"rule":  {"family": "inet",
                                                "table": TABLE_NAME,
                                                "chain": "filter_%s" % "FORWARD",
                                                "expr": [{"reject": {"type": "icmpx", "expr": "admin-prohibited"}}]}}})

        # filter, OUTPUT
        default_rules.append({"add": {"rule":  {"family": "inet",
                                                "table": TABLE_NAME,
                                                "chain": "filter_%s" % "OUTPUT",
                                                "expr": [{"match": {"left": {"ct": {"key": "state"}},
                                                                    "op": "in",
                                                                    "right": {"set": ["established", "related"]}}},
                                                         {"accept": None}]}}})
        default_rules.append({"add": {"rule":  {"family": "inet",
                                                "table": TABLE_NAME,
                                                "chain": "filter_OUTPUT",
                                                "expr": [{"match": {"left": {"meta": {"key": "oifname"}},
                                                          "op": "==",
                                                          "right": "lo"}},
                                                         {"accept": None}]}}})
        for dispatch_suffix in ["POLICIES_pre"]:
            default_rules.append({"add": {"chain": {"family": "inet",
                                                    "table": TABLE_NAME,
                                                    "name": "filter_%s_%s" % ("OUTPUT", dispatch_suffix)}}})
            default_rules.append({"add": {"rule":  {"family": "inet",
                                                    "table": TABLE_NAME,
                                                    "chain": "filter_%s" % "OUTPUT",
                                                    "expr": [{"jump": {"target": "filter_%s_%s" % ("OUTPUT", dispatch_suffix)}}]}}})
        for dispatch_suffix in ["POLICIES_post"]:
            default_rules.append({"add": {"chain": {"family": "inet",
                                                    "table": TABLE_NAME,
                                                    "name": "filter_%s_%s" % ("OUTPUT", dispatch_suffix)}}})
            default_rules.append({"add": {"rule":  {"family": "inet",
                                                    "table": TABLE_NAME,
                                                    "chain": "filter_%s" % "OUTPUT",
                                                    "expr": [{"jump": {"target": "filter_%s_%s" % ("OUTPUT", dispatch_suffix)}}]}}})

        return default_rules

    def get_zone_table_chains(self, table):
        if table == "filter":
            return ["INPUT", "FORWARD"]
        if table == "mangle":
            return ["PREROUTING"]
        if table == "nat":
            return ["PREROUTING", "POSTROUTING"]

        return []

    def build_policy_ingress_egress_rules(self, enable, policy, table, chain,
                                          ingress_interfaces, egress_interfaces,
                                          ingress_sources, egress_sources):

        p_obj = self._fw.policy.get_policy(policy)
        chain_suffix = "pre" if p_obj.priority < 0 else "post"
        isSNAT = True if (table == "nat" and chain == "POSTROUTING") else False
        _policy = self._fw.policy.policy_base_chain_name(policy, table, POLICY_CHAIN_PREFIX, isSNAT)

        ingress_fragments = []
        egress_fragments = []
        ingress_interfaces_without_wildcards = []
        egress_interfaces_without_wildcards = []

        # wildcard interfaces must be handled individually because the nftables
        # backend does not allow them inside of an anonymous set
        for ingress_interface in ingress_interfaces:
            if ingress_interface[len(ingress_interface)-1] == "+":
                ingress_fragments.append({"match": {"left": {"meta": {"key": "iifname"}},
                                                    "op": "==",
                                                    "right": ingress_interface[:len(ingress_interface)-1] + "*"}})
            else:
                ingress_interfaces_without_wildcards.append(ingress_interface)

        for egress_interface in egress_interfaces:
            if egress_interface[len(egress_interface)-1] == "+":
                egress_fragments.append({"match": {"left": {"meta": {"key": "oifname"}},
                                                   "op": "==",
                                                   "right": egress_interface[:len(egress_interface)-1] + "*"}})
            else:
                egress_interfaces_without_wildcards.append(egress_interface)

        if ingress_interfaces_without_wildcards:
            ingress_fragments.append({"match": {"left": {"meta": {"key": "iifname"}},
                                                "op": "==",
                                                "right": {"set": ingress_interfaces_without_wildcards}}})

        if egress_interfaces_without_wildcards:
            egress_fragments.append({"match": {"left": {"meta": {"key": "oifname"}},
                                               "op": "==",
                                               "right": {"set": egress_interfaces_without_wildcards}}})

        if ingress_sources:
            for src in ingress_sources:
                ingress_fragments.append(self._rule_addr_fragment("saddr", src))
        if egress_sources:
            for dst in egress_sources:
                egress_fragments.append(self._rule_addr_fragment("daddr", dst))

        def _generate_policy_dispatch_rule(ingress_fragment, egress_fragment):
            if ingress_fragment and egress_fragment:
                # The IP families must be the same
                #
                if "payload" in ingress_fragment["match"]["left"] and \
                   "payload" in egress_fragment["match"]["left"] and \
                   ingress_fragment["match"]["left"]["payload"]["protocol"] != \
                   egress_fragment["match"]["left"]["payload"]["protocol"]:
                    return None

            expr_fragments = []
            if ingress_fragment:
                expr_fragments.append(ingress_fragment)
            if egress_fragment:
                expr_fragments.append(egress_fragment)
            expr_fragments.append({"jump": {"target": "%s_%s" % (table, _policy)}})

            rule = {"family": "inet",
                    "table": TABLE_NAME,
                    "chain": "%s_%s_POLICIES_%s" % (table, chain, chain_suffix),
                    "expr": expr_fragments}
            rule.update(self._policy_priority_fragment(p_obj))

            if enable:
                return {"add": {"rule": rule}}
            else:
                return {"delete": {"rule": rule}}

        rules = []
        if ingress_fragments: # zone --> [zone, ANY, HOST]
            for ingress_fragment in ingress_fragments:
                if egress_fragments:
                    # zone --> zone
                    for egress_fragment in egress_fragments:
                        rules.append(_generate_policy_dispatch_rule(ingress_fragment, egress_fragment))
                else:
                    # zone --> [ANY, HOST]
                    rules.append(_generate_policy_dispatch_rule(ingress_fragment, None))
        else: # [ANY, HOST] --> [zone, ANY, HOST]
            if egress_fragments:
                # [ANY, HOST] --> zone
                for egress_fragment in egress_fragments:
                    rules.append(_generate_policy_dispatch_rule(None, egress_fragment))
            else:
                # [ANY, HOST] --> [ANY, HOST]
                rules.append(_generate_policy_dispatch_rule(None, None))

        return rules

    def build_zone_source_interface_rules(self, enable, zone, policy, interface,
                                          table, chain, append=False):

        isSNAT = True if (table == "nat" and chain == "POSTROUTING") else False
        _policy = self._fw.policy.policy_base_chain_name(policy, table, POLICY_CHAIN_PREFIX, isSNAT=isSNAT)
        opt = {
            "PREROUTING": "iifname",
            "POSTROUTING": "oifname",
            "INPUT": "iifname",
            "FORWARD": "iifname",
            "OUTPUT": "oifname",
        }[chain]

        if interface[len(interface)-1] == "+":
            interface = interface[:len(interface)-1] + "*"

        action = "goto"

        if interface == "*":
            expr_fragments = [{action: {"target": "%s_%s" % (table, _policy)}}]
        else:
            expr_fragments = [{"match": {"left": {"meta": {"key": opt}},
                                         "op": "==",
                                         "right": interface}},
                              {action: {"target": "%s_%s" % (table, _policy)}}]

        if enable and not append:
            verb = "insert"
            rule = {"family": "inet",
                    "table": TABLE_NAME,
                    "chain": "%s_%s_ZONES" % (table, chain),
                    "expr": expr_fragments}
            rule.update(self._zone_interface_fragment())
        elif enable:
            verb = "add"
            rule = {"family": "inet",
                    "table": TABLE_NAME,
                    "chain": "%s_%s_ZONES" % (table, chain),
                    "expr": expr_fragments}
        else:
            verb = "delete"
            rule = {"family": "inet",
                    "table": TABLE_NAME,
                    "chain": "%s_%s_ZONES" % (table, chain),
                    "expr": expr_fragments}
            if not append:
                rule.update(self._zone_interface_fragment())

        return [{verb: {"rule": rule}}]

    def build_zone_source_address_rules(self, enable, zone, policy,
                                        address, table, chain):
        isSNAT = True if (table == "nat" and chain == "POSTROUTING") else False
        _policy = self._fw.policy.policy_base_chain_name(policy, table, POLICY_CHAIN_PREFIX, isSNAT=isSNAT)
        add_del = { True: "insert", False: "delete" }[enable]

        opt = {
            "PREROUTING": "saddr",
            "POSTROUTING": "daddr",
            "INPUT": "saddr",
            "FORWARD": "saddr",
            "OUTPUT": "daddr",
        }[chain]

        action = "goto"

        rule = {"family": "inet",
                "table": TABLE_NAME,
                "chain": "%s_%s_ZONES" % (table, chain),
                "expr": [self._rule_addr_fragment(opt, address),
                         {action: {"target": "%s_%s" % (table, _policy)}}]}
        rule.update(self._zone_source_fragment(zone, address))
        return [{add_del: {"rule": rule}}]

    def build_policy_chain_rules(self, enable, policy, table, chain):
        add_del = { True: "add", False: "delete" }[enable]
        isSNAT = True if (table == "nat" and chain == "POSTROUTING") else False
        _policy = self._fw.policy.policy_base_chain_name(policy, table, POLICY_CHAIN_PREFIX, isSNAT=isSNAT)
        p_obj = self._fw.policy.get_policy(policy)

        rules = []
        rules.append({add_del: {"chain": {"family": "inet",
                                          "table": TABLE_NAME,
                                          "name": "%s_%s" % (table, _policy)}}})
        for chain_suffix in ["pre", "log", "deny", "allow", "post"]:
            rules.append({add_del: {"chain": {"family": "inet",
                                              "table": TABLE_NAME,
                                              "name": "%s_%s_%s" % (table, _policy, chain_suffix)}}})

        # policy dispatch
        if p_obj.derived_from_zone:
            rules.append({"add": {"rule":  {"family": "inet",
                                                      "table": TABLE_NAME,
                                                      "chain": "%s_%s" % (table, _policy),
                                                      "expr": [{"jump": {"target": "%s_%s_%s" % (table, chain, "POLICIES_pre")}}]}}})

        for chain_suffix in ["pre", "log", "deny", "allow", "post"]:
            rules.append({add_del: {"rule": {"family": "inet",
                                             "table": TABLE_NAME,
                                             "chain": "%s_%s" % (table, _policy),
                                             "expr": [{"jump": {"target": "%s_%s_%s" % (table, _policy, chain_suffix)}}]}}})

        # since zones are always terminal we need to jump to the policy
        # dispatch just before the catch-all accept/drop
        if p_obj.derived_from_zone:
            rules.append({"add": {"rule":  {"family": "inet",
                                                      "table": TABLE_NAME,
                                                      "chain": "%s_%s" % (table, _policy),
                                                      "expr": [{"jump": {"target": "%s_%s_%s" % (table, chain, "POLICIES_post")}}]}}})

        target = self._fw.policy._policies[policy].target

        if self._fw.get_log_denied() != "off":
            if table == "filter":
                if target in [DEFAULT_ZONE_TARGET, "REJECT", "%%REJECT%%", "DROP"]:
                    log_suffix = target
                    if target in [DEFAULT_ZONE_TARGET, "%%REJECT%%"]:
                        log_suffix = "REJECT"
                    rules.append({add_del: {"rule": {"family": "inet",
                                                     "table": TABLE_NAME,
                                                     "chain": "%s_%s" % (table, _policy),
                                                     "expr": [self._pkttype_match_fragment(self._fw.get_log_denied()),
                                                              {"log": {"prefix": "filter_%s_%s: " % (_policy, log_suffix)}}]}}})

        if table == "filter" and \
           target in [DEFAULT_ZONE_TARGET, "ACCEPT", "REJECT", "%%REJECT%%", "DROP"]:
            if target in [DEFAULT_ZONE_TARGET, "%%REJECT%%", "REJECT"]:
                target_fragment = self._reject_fragment()
            else:
                target_fragment = {target.lower(): None}
            rules.append({add_del: {"rule": {"family": "inet",
                                             "table": TABLE_NAME,
                                             "chain": "%s_%s" % (table, _policy),
                                             "expr": [target_fragment]}}})

        if not enable:
            rules.reverse()

        return rules

    def _pkttype_match_fragment(self, pkttype):
        if pkttype == "all":
            return {}
        elif pkttype in ["unicast", "broadcast", "multicast"]:
            return {"match": {"left": {"meta": {"key": "pkttype"}},
                               "op": "==",
                               "right": pkttype}}

        raise FirewallError(INVALID_RULE, "Invalid pkttype \"%s\"", pkttype)

    def _reject_types_fragment(self, reject_type):
        frags = {
            # REJECT_TYPES              : <nft reject rule fragment>
            "icmp-host-prohibited"      : {"reject": {"type": "icmp", "expr": "host-prohibited"}},
            "host-prohib"               : {"reject": {"type": "icmp", "expr": "host-prohibited"}},
            "icmp-net-prohibited"       : {"reject": {"type": "icmp", "expr": "net-prohibited"}},
            "net-prohib"                : {"reject": {"type": "icmp", "expr": "net-prohibited"}},
            "icmp-admin-prohibited"     : {"reject": {"type": "icmp", "expr": "admin-prohibited"}},
            "admin-prohib"              : {"reject": {"type": "icmp", "expr": "admin-prohibited"}},
            "icmp6-adm-prohibited"      : {"reject": {"type": "icmpv6", "expr": "admin-prohibited"}},
            "adm-prohibited"            : {"reject": {"type": "icmpv6", "expr": "admin-prohibited"}},

            "icmp-net-unreachable"      : {"reject": {"type": "icmp", "expr": "net-unreachable"}},
            "net-unreach"               : {"reject": {"type": "icmp", "expr": "net-unreachable"}},
            "icmp-host-unreachable"     : {"reject": {"type": "icmp", "expr": "host-unreachable"}},
            "host-unreach"              : {"reject": {"type": "icmp", "expr": "host-unreachable"}},
            "icmp-port-unreachable"     : {"reject": {"type": "icmp", "expr": "port-unreachable"}},
            "icmp6-port-unreachable"    : {"reject": {"type": "icmpv6", "expr": "port-unreachable"}},
            "port-unreach"              : {"reject": {"type": "icmpx", "expr": "port-unreachable"}},
            "icmp-proto-unreachable"    : {"reject": {"type": "icmp", "expr": "prot-unreachable"}},
            "proto-unreach"             : {"reject": {"type": "icmp", "expr": "prot-unreachable"}},
            "icmp6-addr-unreachable"    : {"reject": {"type": "icmpv6", "expr": "addr-unreachable"}},
            "addr-unreach"              : {"reject": {"type": "icmpv6", "expr": "addr-unreachable"}},

            "icmp6-no-route"            : {"reject": {"type": "icmpv6", "expr": "no-route"}},
            "no-route"                  : {"reject": {"type": "icmpv6", "expr": "no-route"}},

            "tcp-reset"                 : {"reject": {"type": "tcp reset"}},
            "tcp-rst"                   : {"reject": {"type": "tcp reset"}},
        }
        return frags[reject_type]

    def _reject_fragment(self):
        return {"reject": {"type": "icmpx",
                           "expr": "admin-prohibited"}}

    def _icmp_match_fragment(self):
        return {"match": {"left": {"meta": {"key": "l4proto"}},
                          "op": "==",
                          "right": {"set": ["icmp", "icmpv6"]}}}

    def _rich_rule_limit_fragment(self, limit):
        if not limit:
            return {}

        rich_to_nft = {
            "s" : "second",
            "m" : "minute",
            "h" : "hour",
            "d" : "day",
        }

        try:
            i = limit.value.index("/")
        except ValueError:
            raise FirewallError(INVALID_RULE, "Expected '/' in limit")

        return {"limit": {"rate": int(limit.value[0:i]),
                          "per": rich_to_nft[limit.value[i+1]]}}

    def _rich_rule_chain_suffix(self, rich_rule):
        if type(rich_rule.element) in [Rich_Masquerade, Rich_ForwardPort, Rich_IcmpBlock, Rich_Tcp_Mss_Clamp]:
            # These are special and don't have an explicit action
            pass
        elif rich_rule.action:
            if type(rich_rule.action) not in [Rich_Accept, Rich_Reject, Rich_Drop, Rich_Mark]:
                raise FirewallError(INVALID_RULE, "Unknown action %s" % type(rich_rule.action))
        else:
            raise FirewallError(INVALID_RULE, "No rule action specified.")

        if rich_rule.priority == 0:
            if type(rich_rule.element) in [Rich_Masquerade, Rich_ForwardPort, Rich_Tcp_Mss_Clamp] or \
               type(rich_rule.action) in [Rich_Accept, Rich_Mark]:
                return "allow"
            elif type(rich_rule.element) in [Rich_IcmpBlock] or \
                 type(rich_rule.action) in [Rich_Reject, Rich_Drop]:
                return "deny"
        elif rich_rule.priority < 0:
            return "pre"
        else:
            return "post"

    def _rich_rule_chain_suffix_from_log(self, rich_rule):
        if not rich_rule.log and not rich_rule.audit:
            raise FirewallError(INVALID_RULE, "Not log or audit")

        if rich_rule.priority == 0:
            return "log"
        elif rich_rule.priority < 0:
            return "pre"
        else:
            return "post"

    def _zone_interface_fragment(self):
        return {"%%ZONE_INTERFACE%%": None}

    def _zone_source_fragment(self, zone, address):
        if check_single_address("ipv6", address):
            address = normalizeIP6(address)
        elif check_address("ipv6", address):
            addr_split = address.split("/")
            address = normalizeIP6(addr_split[0]) + "/" + addr_split[1]
        return {"%%ZONE_SOURCE%%": {"zone": zone, "address": address}}

    def _policy_priority_fragment(self, policy):
        return {"%%POLICY_PRIORITY%%": policy.priority}

    def _rich_rule_priority_fragment(self, rich_rule):
        if not rich_rule or rich_rule.priority == 0:
            return {}
        return {"%%RICH_RULE_PRIORITY%%": rich_rule.priority}

    def _rich_rule_log(self, policy, rich_rule, enable, table, expr_fragments):
        if not rich_rule.log:
            return {}

        _policy = self._fw.policy.policy_base_chain_name(policy, table, POLICY_CHAIN_PREFIX)

        add_del = { True: "add", False: "delete" }[enable]

        chain_suffix = self._rich_rule_chain_suffix_from_log(rich_rule)

        log_options = {}
        if type(rich_rule.log) == Rich_NFLog:
            log_options["group"] = int(rich_rule.log.group) if rich_rule.log.group else 0
            if rich_rule.log.threshold:
                log_options["queue-threshold"] = int(rich_rule.log.threshold)
        else:
            if rich_rule.log.level:
                level = "warn" if "warning" == rich_rule.log.level else rich_rule.log.level
                log_options["level"] = "%s" % level

        if rich_rule.log.prefix:
            log_options["prefix"] = "%s" % rich_rule.log.prefix

        rule = {"family": "inet",
                "table": TABLE_NAME,
                "chain": "%s_%s_%s" % (table, _policy, chain_suffix),
                "expr": expr_fragments +
                        [self._rich_rule_limit_fragment(rich_rule.log.limit),
                         {"log": log_options}]}
        rule.update(self._rich_rule_priority_fragment(rich_rule))
        return {add_del: {"rule": rule}}

    def _rich_rule_audit(self, policy, rich_rule, enable, table, expr_fragments):
        if not rich_rule.audit:
            return {}

        _policy = self._fw.policy.policy_base_chain_name(policy, table, POLICY_CHAIN_PREFIX)

        add_del = { True: "add", False: "delete" }[enable]

        chain_suffix = self._rich_rule_chain_suffix_from_log(rich_rule)
        rule = {"family": "inet",
                "table": TABLE_NAME,
                "chain": "%s_%s_%s" % (table, _policy, chain_suffix),
                "expr": expr_fragments +
                        [self._rich_rule_limit_fragment(rich_rule.audit.limit),
                         {"log": {"level": "audit"}}]}
        rule.update(self._rich_rule_priority_fragment(rich_rule))
        return {add_del: {"rule": rule}}

    def _rich_rule_action(self, policy, rich_rule, enable, table, expr_fragments):
        if not rich_rule.action:
            return {}

        _policy = self._fw.policy.policy_base_chain_name(policy, table, POLICY_CHAIN_PREFIX)

        add_del = { True: "add", False: "delete" }[enable]

        chain_suffix = self._rich_rule_chain_suffix(rich_rule)
        chain = "%s_%s_%s" % (table, _policy, chain_suffix)
        if type(rich_rule.action) == Rich_Accept:
            rule_action = {"accept": None}
        elif type(rich_rule.action) == Rich_Reject:
            if rich_rule.action.type:
                rule_action = self._reject_types_fragment(rich_rule.action.type)
            else:
                rule_action = {"reject": None}
        elif type(rich_rule.action) ==  Rich_Drop:
            rule_action = {"drop": None}
        elif type(rich_rule.action) == Rich_Mark:
            table = "mangle"
            _policy = self._fw.policy.policy_base_chain_name(policy, table, POLICY_CHAIN_PREFIX)
            chain = "%s_%s_%s" % (table, _policy, chain_suffix)
            value = rich_rule.action.set.split("/")
            if len(value) > 1:
                rule_action = {"mangle": {"key": {"meta": {"key": "mark"}},
                                          "value": {"^": [{"&": [{"meta": {"key": "mark"}}, value[1]]}, value[0]]}}}
            else:
                rule_action = {"mangle": {"key": {"meta": {"key": "mark"}},
                                          "value": value[0]}}

        else:
            raise FirewallError(INVALID_RULE,
                                "Unknown action %s" % type(rich_rule.action))

        rule = {"family": "inet",
                "table": TABLE_NAME,
                "chain": chain,
                "expr": expr_fragments +
                        [self._rich_rule_limit_fragment(rich_rule.action.limit), rule_action]}
        rule.update(self._rich_rule_priority_fragment(rich_rule))
        return {add_del: {"rule": rule}}

    def _rule_addr_fragment(self, addr_field, address, invert=False):
        if address.startswith("ipset:"):
            return self._set_match_fragment(address[len("ipset:"):], True if "daddr" == addr_field else False, invert)
        else:
            if check_mac(address):
                family = "ether"
            elif check_single_address("ipv4", address):
                family = "ip"
            elif check_address("ipv4", address):
                family = "ip"
                normalized_address = ipaddress.IPv4Network(address, strict=False)
                address = {"prefix": {"addr": normalized_address.network_address.compressed, "len": normalized_address.prefixlen}}
            elif check_single_address("ipv6", address):
                family = "ip6"
                address = normalizeIP6(address)
            else:
                family = "ip6"
                addr_len = address.split("/")
                address = {"prefix": {"addr": normalizeIP6(addr_len[0]), "len": int(addr_len[1])}}

            return {"match": {"left": {"payload": {"protocol": family,
                                                   "field": addr_field}},
                              "op": "!=" if invert else "==",
                              "right": address}}

    def _rich_rule_family_fragment(self, rich_family):
        if not rich_family:
            return {}
        if rich_family not in ["ipv4", "ipv6"]:
            raise FirewallError(INVALID_RULE,
                                "Invalid family" % rich_family)

        return {"match": {"left": {"meta": {"key": "nfproto"}},
                          "op": "==",
                          "right": rich_family}}

    def _rich_rule_destination_fragment(self, rich_dest):
        if not rich_dest:
            return {}
        if rich_dest.addr:
            address = rich_dest.addr
        elif rich_dest.ipset:
            address = "ipset:" + rich_dest.ipset

        return self._rule_addr_fragment("daddr", address, invert=rich_dest.invert)

    def _rich_rule_source_fragment(self, rich_source):
        if not rich_source:
            return {}

        if rich_source.addr:
            address = rich_source.addr
        elif hasattr(rich_source, "mac") and rich_source.mac:
            address = rich_source.mac
        elif hasattr(rich_source, "ipset") and rich_source.ipset:
            address = "ipset:" + rich_source.ipset

        return self._rule_addr_fragment("saddr", address, invert=rich_source.invert)

    def _port_fragment(self, port):
        range = getPortRange(port)
        if isinstance(range, int) and range < 0:
            raise FirewallError(INVALID_PORT)
        elif len(range) == 1:
            return range[0]
        else:
            return {"range": [range[0], range[1]]}

    def build_policy_ports_rules(self, enable, policy, proto, port, destination=None, rich_rule=None):
        add_del = { True: "add", False: "delete" }[enable]
        table = "filter"
        _policy = self._fw.policy.policy_base_chain_name(policy, table, POLICY_CHAIN_PREFIX)

        expr_fragments = []
        if rich_rule:
            expr_fragments.append(self._rich_rule_family_fragment(rich_rule.family))
        if destination:
            expr_fragments.append(self._rule_addr_fragment("daddr", destination))
        if rich_rule:
            expr_fragments.append(self._rich_rule_destination_fragment(rich_rule.destination))
            expr_fragments.append(self._rich_rule_source_fragment(rich_rule.source))

        expr_fragments.append({"match": {"left": {"payload": {"protocol": proto,
                                                              "field": "dport"}},
                                         "op": "==",
                                         "right": self._port_fragment(port)}})

        rules = []
        if rich_rule:
            rules.append(self._rich_rule_log(policy, rich_rule, enable, table, expr_fragments))
            rules.append(self._rich_rule_audit(policy, rich_rule, enable, table, expr_fragments))
            rules.append(self._rich_rule_action(policy, rich_rule, enable, table, expr_fragments))
        else:
            rules.append({add_del: {"rule": {"family": "inet",
                                             "table": TABLE_NAME,
                                             "chain": "%s_%s_allow" % (table, _policy),
                                             "expr": expr_fragments + [{"accept": None}]}}})

        return rules

    def build_policy_protocol_rules(self, enable, policy, protocol, destination=None, rich_rule=None):
        add_del = { True: "add", False: "delete" }[enable]
        table = "filter"
        _policy = self._fw.policy.policy_base_chain_name(policy, table, POLICY_CHAIN_PREFIX)

        expr_fragments = []
        if rich_rule:
            expr_fragments.append(self._rich_rule_family_fragment(rich_rule.family))
        if destination:
            expr_fragments.append(self._rule_addr_fragment("daddr", destination))
        if rich_rule:
            expr_fragments.append(self._rich_rule_destination_fragment(rich_rule.destination))
            expr_fragments.append(self._rich_rule_source_fragment(rich_rule.source))

        expr_fragments.append({"match": {"left": {"meta": {"key": "l4proto"}},
                                         "op": "==",
                                         "right": protocol}})

        rules = []
        if rich_rule:
            rules.append(self._rich_rule_log(policy, rich_rule, enable, table, expr_fragments))
            rules.append(self._rich_rule_audit(policy, rich_rule, enable, table, expr_fragments))
            rules.append(self._rich_rule_action(policy, rich_rule, enable, table, expr_fragments))
        else:
            rules.append({add_del: {"rule": {"family": "inet",
                                             "table": TABLE_NAME,
                                             "chain": "%s_%s_allow" % (table, _policy),
                                             "expr": expr_fragments + [{"accept": None}]}}})

        return rules

    def build_policy_tcp_mss_clamp_rules(self, enable, policy, tcp_mss_clamp_value,
                                      destination=None, rich_rule=None):
        chain_suffix = "allow"
        table = "filter"
        _policy = self._fw.policy.policy_base_chain_name(policy, table, POLICY_CHAIN_PREFIX)
        add_del = { True: "add", False: "delete" }[enable]

        expr_fragments = []
        if rich_rule:
            expr_fragments.append(self._rich_rule_destination_fragment(rich_rule.destination))
            expr_fragments.append(self._rich_rule_source_fragment(rich_rule.source))
            chain_suffix = self._rich_rule_chain_suffix(rich_rule)

        expr_fragments.append({"match": {"op": "in",
                                         "left": {"payload": {"protocol": "tcp","field": "flags"}},
                                         "right": "syn"}})

        if tcp_mss_clamp_value == "pmtu" or tcp_mss_clamp_value is None:
            expr_fragments.append({"mangle": {"key": {"tcp option": {"name": "maxseg","field": "size"}},
                                              "value": {"rt": {"key": "mtu" }}}})
        else:
            expr_fragments.append({"mangle": {"key": {"tcp option": {"name": "maxseg","field": "size"}},
                                              "value": tcp_mss_clamp_value}})

        return [{add_del: {"rule": {"family": "inet",
                           "table": TABLE_NAME,
                           "chain": "filter_%s_%s" % (_policy, chain_suffix),
                           "expr": expr_fragments}}}]

    def build_policy_source_ports_rules(self, enable, policy, proto, port,
                                      destination=None, rich_rule=None):
        add_del = { True: "add", False: "delete" }[enable]
        table = "filter"
        _policy = self._fw.policy.policy_base_chain_name(policy, table, POLICY_CHAIN_PREFIX)

        expr_fragments = []
        if rich_rule:
            expr_fragments.append(self._rich_rule_family_fragment(rich_rule.family))
        if destination:
            expr_fragments.append(self._rule_addr_fragment("daddr", destination))
        if rich_rule:
            expr_fragments.append(self._rich_rule_destination_fragment(rich_rule.destination))
            expr_fragments.append(self._rich_rule_source_fragment(rich_rule.source))

        expr_fragments.append({"match": {"left": {"payload": {"protocol": proto,
                                                              "field": "sport"}},
                                         "op": "==",
                                         "right": self._port_fragment(port)}})

        rules = []
        if rich_rule:
            rules.append(self._rich_rule_log(policy, rich_rule, enable, table, expr_fragments))
            rules.append(self._rich_rule_audit(policy, rich_rule, enable, table, expr_fragments))
            rules.append(self._rich_rule_action(policy, rich_rule, enable, table, expr_fragments))
        else:
            rules.append({add_del: {"rule": {"family": "inet",
                                             "table": TABLE_NAME,
                                             "chain": "%s_%s_allow" % (table, _policy),
                                             "expr": expr_fragments + [{"accept": None}]}}})

        return rules

    def build_policy_helper_ports_rules(self, enable, policy, proto, port,
                                        destination, helper_name, module_short_name):
        table = "filter"
        _policy = self._fw.policy.policy_base_chain_name(policy, table, POLICY_CHAIN_PREFIX)
        add_del = { True: "add", False: "delete" }[enable]
        rules = []

        if enable:
            rules.append({"add": {"ct helper": {"family": "inet",
                                                "table": TABLE_NAME,
                                                "name": "helper-%s-%s" % (helper_name, proto),
                                                "type": module_short_name,
                                                "protocol": proto}}})

        expr_fragments = []
        if destination:
            expr_fragments.append(self._rule_addr_fragment("daddr", destination))
        expr_fragments.append({"match": {"left": {"payload": {"protocol": proto,
                                                              "field": "dport"}},
                                         "op": "==",
                                         "right": self._port_fragment(port)}})
        expr_fragments.append({"ct helper": "helper-%s-%s" % (helper_name, proto)})
        rules.append({add_del: {"rule": {"family": "inet",
                                         "table": TABLE_NAME,
                                         "chain": "filter_%s_allow" % (_policy),
                                         "expr": expr_fragments}}})

        return rules

    def build_zone_forward_rules(self, enable, zone, policy, table, interface=None, source=None):
        add_del = { True: "add", False: "delete" }[enable]
        _policy = self._fw.policy.policy_base_chain_name(policy, table, POLICY_CHAIN_PREFIX)

        rules = []

        if interface:
            if interface[len(interface)-1] == "+":
                interface = interface[:len(interface)-1] + "*"

            expr = [{"match": {"left": {"meta": {"key": "oifname"}},
                               "op": "==",
                               "right": interface}},
                    {"accept": None}]
        else: # source
            expr = [self._rule_addr_fragment("daddr", source), {"accept": None}]

        rule = {"family": "inet",
                "table": TABLE_NAME,
                "chain": "filter_%s_allow" % (_policy),
                "expr": expr}
        rules.append({add_del: {"rule": rule}})

        return rules

    def build_policy_masquerade_rules(self, enable, policy, rich_rule=None):
        add_del = { True: "add", False: "delete" }[enable]

        rules = []

        expr_fragments = []
        if rich_rule:
            expr_fragments.append(self._rich_rule_family_fragment(rich_rule.family))
            expr_fragments.append(self._rich_rule_destination_fragment(rich_rule.destination))
            expr_fragments.append(self._rich_rule_source_fragment(rich_rule.source))
            chain_suffix = self._rich_rule_chain_suffix(rich_rule)
        else:
            expr_fragments.append({"match": {"left": {"meta": {"key": "nfproto"}},
                                             "op": "==",
                                             "right": "ipv4"}})
            chain_suffix = "allow"

        table = "nat"
        _policy = self._fw.policy.policy_base_chain_name(policy, table, POLICY_CHAIN_PREFIX, isSNAT=True)
        rule = {"family": "inet",
                "table": TABLE_NAME,
                "chain": "nat_%s_%s" % (_policy, chain_suffix),
                "expr": expr_fragments +
                        [{"match": {"left": {"meta": {"key": "oifname"}},
                                    "op": "!=",
                                    "right": "lo"}},
                         {"masquerade": None}]}
        rule.update(self._rich_rule_priority_fragment(rich_rule))
        rules.append({add_del: {"rule": rule}})

        return rules

    def build_policy_forward_port_rules(self, enable, policy, port,
                                      protocol, toport, toaddr, rich_rule=None):
        table = "nat"
        _policy = self._fw.policy.policy_base_chain_name(policy, table, POLICY_CHAIN_PREFIX)
        add_del = { True: "add", False: "delete" }[enable]

        expr_fragments = []
        if rich_rule:
            expr_fragments.append(self._rich_rule_family_fragment(rich_rule.family))
            expr_fragments.append(self._rich_rule_destination_fragment(rich_rule.destination))
            expr_fragments.append(self._rich_rule_source_fragment(rich_rule.source))
            chain_suffix = self._rich_rule_chain_suffix(rich_rule)
        else:
            nfproto = "ipv4"
            if toaddr and check_single_address("ipv6", toaddr):
                nfproto = "ipv6"
            expr_fragments.append({"match": {"left": {"meta": {"key": "nfproto"}},
                                             "op": "==",
                                             "right": nfproto}})
            chain_suffix = "allow"

        expr_fragments.append({"match": {"left": {"payload": {"protocol": protocol,
                                                              "field": "dport"}},
                                         "op": "==",
                                         "right": self._port_fragment(port)}})

        if toaddr:
            if check_single_address("ipv6", toaddr):
                toaddr = normalizeIP6(toaddr)
            if toport and toport != "":
                expr_fragments.append({"dnat": {"addr": toaddr, "port": self._port_fragment(toport)}})
            else:
                expr_fragments.append({"dnat": {"addr": toaddr}})
        else:
            expr_fragments.append({"redirect": {"port": self._port_fragment(toport)}})

        rule = {"family": "inet",
                "table": TABLE_NAME,
                "chain": "nat_%s_%s" % (_policy, chain_suffix),
                "expr": expr_fragments}
        rule.update(self._rich_rule_priority_fragment(rich_rule))
        return [{add_del: {"rule": rule}}]

    def _icmp_types_to_nft_fragments(self, ipv, icmp_type):
        if icmp_type in ICMP_TYPES_FRAGMENTS[ipv]:
            return ICMP_TYPES_FRAGMENTS[ipv][icmp_type]
        else:
            raise FirewallError(INVALID_ICMPTYPE,
                                "ICMP type '%s' not supported by %s for %s" % (icmp_type, self.name, ipv))

    def build_policy_icmp_block_rules(self, enable, policy, ict, rich_rule=None):
        table = "filter"
        _policy = self._fw.policy.policy_base_chain_name(policy, table, POLICY_CHAIN_PREFIX)
        add_del = { True: "add", False: "delete" }[enable]

        if rich_rule and rich_rule.ipvs:
            ipvs = rich_rule.ipvs
        elif ict.destination:
            ipvs = []
            if "ipv4" in ict.destination:
                ipvs.append("ipv4")
            if "ipv6" in ict.destination:
                ipvs.append("ipv6")
        else:
            ipvs = ["ipv4", "ipv6"]

        rules = []
        for ipv in ipvs:
            if self._fw.policy.query_icmp_block_inversion(policy):
                final_chain = "%s_%s_allow" % (table, _policy)
                target_fragment = {"accept": None}
            else:
                final_chain = "%s_%s_deny" % (table, _policy)
                target_fragment = self._reject_fragment()

            expr_fragments = []
            if rich_rule:
                expr_fragments.append(self._rich_rule_family_fragment(rich_rule.family))
                expr_fragments.append(self._rich_rule_destination_fragment(rich_rule.destination))
                expr_fragments.append(self._rich_rule_source_fragment(rich_rule.source))
            expr_fragments.extend(self._icmp_types_to_nft_fragments(ipv, ict.name))

            if rich_rule:
                rules.append(self._rich_rule_log(policy, rich_rule, enable, table, expr_fragments))
                rules.append(self._rich_rule_audit(policy, rich_rule, enable, table, expr_fragments))
                if rich_rule.action:
                    rules.append(self._rich_rule_action(policy, rich_rule, enable, table, expr_fragments))
                else:
                    chain_suffix = self._rich_rule_chain_suffix(rich_rule)
                    rule = {"family": "inet",
                            "table": TABLE_NAME,
                            "chain": "%s_%s_%s" % (table, _policy, chain_suffix),
                            "expr": expr_fragments + [self._reject_fragment()]}
                    rule.update(self._rich_rule_priority_fragment(rich_rule))
                    rules.append({add_del: {"rule": rule}})
            else:
                if self._fw.get_log_denied() != "off" and not self._fw.policy.query_icmp_block_inversion(policy):
                    rules.append({add_del: {"rule": {"family": "inet",
                                                     "table": TABLE_NAME,
                                                     "chain": final_chain,
                                                     "expr": (expr_fragments +
                                                              [self._pkttype_match_fragment(self._fw.get_log_denied()),
                                                               {"log": {"prefix": "%s_%s_ICMP_BLOCK: " % (table, policy)}}])}}})
                rules.append({add_del: {"rule": {"family": "inet",
                                                 "table": TABLE_NAME,
                                                 "chain": final_chain,
                                                 "expr": expr_fragments + [target_fragment]}}})

        return rules

    def build_policy_icmp_block_inversion_rules(self, enable, policy):
        table = "filter"
        _policy = self._fw.policy.policy_base_chain_name(policy, table, POLICY_CHAIN_PREFIX)
        rules = []
        add_del = { True: "add", False: "delete" }[enable]

        if self._fw.policy.query_icmp_block_inversion(policy):
            target_fragment = self._reject_fragment()
        else:
            target_fragment = {"accept": None}

        # WARN: The "index" used here must be kept in sync with
        # build_policy_chain_rules()
        #
        rules.append({add_del: {"rule": {"family": "inet",
                                         "table": TABLE_NAME,
                                         "chain": "%s_%s" % (table, _policy),
                                         "index": 6,
                                         "expr": [self._icmp_match_fragment(),
                                                  target_fragment]}}})

        if self._fw.get_log_denied() != "off" and self._fw.policy.query_icmp_block_inversion(policy):
            rules.append({add_del: {"rule": {"family": "inet",
                                             "table": TABLE_NAME,
                                             "chain": "%s_%s" % (table, _policy),
                                             "index": 6,
                                             "expr": [self._icmp_match_fragment(),
                                                      self._pkttype_match_fragment(self._fw.get_log_denied()),
                                                      {"log": {"prefix": "%s_%s_ICMP_BLOCK: " % (table, policy)}}]}}})
        return rules

    def build_rpfilter_rules(self, log_denied=False):
        rules = []
        rpfilter_chain = "filter_PREROUTING"

        if self._fw._ipv6_rpfilter == "loose":
            fib_flags = ["saddr", "mark"]
        elif self._fw._ipv6_rpfilter == "loose-forward":
            fib_flags = ["saddr", "mark"]
            rpfilter_chain = "filter_FORWARD"
        elif self._fw._ipv6_rpfilter == "strict-forward":
            fib_flags = ["saddr", "mark", "iif"]
            rpfilter_chain = "filter_FORWARD"
        else:
            fib_flags = ["saddr", "mark", "iif"]

        expr_fragments = [{"match": {"left": {"meta": {"key": "nfproto"}},
                                     "op": "==",
                                     "right": "ipv6"}},
                          {"match": {"left": {"fib": {"flags": fib_flags,
                                                      "result": "oif"}},
                                     "op": "==",
                                     "right": False}}]
        if log_denied != "off":
            expr_fragments.append({"log": {"prefix": "rpfilter_DROP: "}})
        expr_fragments.append({"drop": None})

        rules.append({"insert": {"rule": {"family": "inet",
                                          "table": TABLE_NAME,
                                          "chain": rpfilter_chain,
                                          "expr": expr_fragments}}})
        # RHBZ#1058505, RHBZ#1575431 (bug in kernel 4.16-4.17)
        if self._fw._ipv6_rpfilter not in ("loose-forward", "strict-forward"):
            # this rule doesn't make sense for forwarded packets
            rules.append({"insert": {"rule": {"family": "inet",
                                              "table": TABLE_NAME,
                                              "chain": rpfilter_chain,
                                              "expr": [{"match": {"left": {"payload": {"protocol": "icmpv6",
                                                                                       "field": "type"}},
                                                                  "op": "==",
                                                                  "right": {"set": ["nd-router-advert", "nd-neighbor-solicit"]}}},
                                                       {"accept": None}]}}})
        return rules

    def build_rfc3964_ipv4_rules(self):
        daddr_set = ["::0.0.0.0/96", # IPv4 compatible
                     "::ffff:0.0.0.0/96", # IPv4 mapped
                     "2002:0000::/24", # 0.0.0.0/8 (the system has no address assigned yet)
                     "2002:0a00::/24", # 10.0.0.0/8 (private)
                     "2002:7f00::/24", # 127.0.0.0/8 (loopback)
                     "2002:ac10::/28", # 172.16.0.0/12 (private)
                     "2002:c0a8::/32", # 192.168.0.0/16 (private)
                     "2002:a9fe::/32", # 169.254.0.0/16 (IANA Assigned DHCP link-local)
                     "2002:e000::/19", # 224.0.0.0/4 (multicast), 240.0.0.0/4 (reserved and broadcast)
                     ]
        daddr_set = [{"prefix": {"addr": x.split("/")[0], "len": int(x.split("/")[1])}} for x in daddr_set]

        expr_fragments = [{"match": {"left": {"payload": {"protocol": "ip6",
                                                          "field": "daddr"}},
                                     "op": "==",
                                     "right": {"set": daddr_set}}}]
        if self._fw._log_denied in ["unicast", "all"]:
            expr_fragments.append({"log": {"prefix": "RFC3964_IPv4_REJECT: "}})
        expr_fragments.append(self._reject_types_fragment("addr-unreach"))

        rules = []
        # WARN: index must be kept in sync with build_default_rules()
        rules.append({"add": {"rule": {"family": "inet",
                                       "table": TABLE_NAME,
                                       "chain": "filter_OUTPUT",
                                       "index": 1,
                                       "expr": expr_fragments}}})
        forward_index = 3
        if self._fw.get_log_denied() != "off":
            forward_index += 1
        if self._fw._ipv6_rpfilter in ("loose-forward", "strict-forward"):
            forward_index += 1
        rules.append({"add": {"rule": {"family": "inet",
                                       "table": TABLE_NAME,
                                       "chain": "filter_FORWARD",
                                       "index": forward_index,
                                       "expr": expr_fragments}}})
        return rules

    def build_policy_rich_source_destination_rules(self, enable, policy, rich_rule):
        table = "filter"

        expr_fragments = []
        expr_fragments.append(self._rich_rule_family_fragment(rich_rule.family))
        expr_fragments.append(self._rich_rule_destination_fragment(rich_rule.destination))
        expr_fragments.append(self._rich_rule_source_fragment(rich_rule.source))

        rules = []
        rules.append(self._rich_rule_log(policy, rich_rule, enable, table, expr_fragments))
        rules.append(self._rich_rule_audit(policy, rich_rule, enable, table, expr_fragments))
        rules.append(self._rich_rule_action(policy, rich_rule, enable, table, expr_fragments))

        return rules

    def is_ipv_supported(self, ipv):
        if ipv in ["ipv4", "ipv6", "eb"]:
            return True
        return False

    def _set_type_list(self, ipv, type):
        ipv_addr = {
            "ipv4" : "ipv4_addr",
            "ipv6" : "ipv6_addr",
        }
        types = {
            "hash:ip" : ipv_addr[ipv],
            "hash:ip,port" : [ipv_addr[ipv], "inet_proto", "inet_service"],
            "hash:ip,port,ip" : [ipv_addr[ipv], "inet_proto", "inet_service", ipv_addr[ipv]],
            "hash:ip,port,net" : [ipv_addr[ipv], "inet_proto", "inet_service", ipv_addr[ipv]],
            "hash:ip,mark" : [ipv_addr[ipv], "mark"],

            "hash:net" : ipv_addr[ipv],
            "hash:net,net" : [ipv_addr[ipv], ipv_addr[ipv]],
            "hash:net,port" : [ipv_addr[ipv], "inet_proto", "inet_service"],
            "hash:net,port,net" : [ipv_addr[ipv], "inet_proto", "inet_service", ipv_addr[ipv]],
            "hash:net,iface" : [ipv_addr[ipv], "ifname"],

            "hash:mac" : "ether_addr",
        }
        if type in types:
            return types[type]
        else:
            raise FirewallError(INVALID_TYPE,
                                "ipset type name '%s' is not valid" % type)

    def build_set_create_rules(self, name, type, options=None):
        if options and "family" in options and options["family"] == "inet6":
            ipv = "ipv6"
        else:
            ipv = "ipv4"

        set_dict = {"family": "inet",
                    "table": TABLE_NAME,
                    "name": name,
                    "type": self._set_type_list(ipv, type)}

        # Some types need the interval flag
        for t in type.split(":")[1].split(","):
            if t in ["ip", "net", "port"]:
                set_dict["flags"] = ["interval"]
                break

        if options:
            if "timeout" in options:
                set_dict["timeout"] = int(options["timeout"])
            if "maxelem" in options:
                set_dict["size"] = int(options["maxelem"])

        return [{"add": {"set": set_dict}}]

    def set_create(self, name, type, options=None):
        rules = self.build_set_create_rules(name, type, options)
        self.set_rules(rules, self._fw.get_log_denied())

    def set_destroy(self, name):
        rule = {"delete": {"set": {"family": "inet",
                                   "table": TABLE_NAME,
                                   "name": name}}}
        self.set_rule(rule, self._fw.get_log_denied())

    def _set_match_fragment(self, name, match_dest, invert=False):
        type_format = self._fw.ipset.get_ipset(name).type.split(":")[1].split(",")

        fragments = []
        for format in type_format:
            if format == "port":
                fragments.append({"meta": {"key": "l4proto"}})
                fragments.append({"payload": {"protocol": "th",
                                              "field": "dport" if match_dest else "sport"}})
            elif format in ["ip", "net", "mac"]:
                fragments.append({"payload": {"protocol": self._set_get_family(name),
                                              "field": "daddr" if match_dest else "saddr"}})
            elif format == "iface":
                fragments.append({"meta": {"key": "iifname" if match_dest else "oifname"}})
            elif format == "mark":
                fragments.append({"meta": {"key": "mark"}})
            else:
                raise FirewallError(INVALID_TYPE, "Unsupported ipset type for match fragment: %s" % (format))

        return {"match": {"left": {"concat": fragments} if len(type_format) > 1 else fragments[0],
                          "op": "!=" if invert else "==",
                          "right": "@" + name}}

    def _set_entry_fragment(self, name, entry):
        # convert something like
        #    1.2.3.4,sctp:8080 (type hash:ip,port)
        # to
        #    ["1.2.3.4", "sctp", "8080"]
        obj = self._fw.ipset.get_ipset(name)
        type_format = obj.type.split(":")[1].split(",")
        entry_tokens = entry.split(",")
        if len(type_format) != len(entry_tokens):
            raise FirewallError(INVALID_ENTRY,
                                "Number of values does not match ipset type.")
        fragment = []
        for i, format in enumerate(type_format):
            if format == "port":
                try:
                    index = entry_tokens[i].index(":")
                except ValueError:
                    # no protocol means default tcp
                    fragment.append("tcp")
                    port_str = entry_tokens[i]
                else:
                    fragment.append(entry_tokens[i][:index])
                    port_str = entry_tokens[i][index+1:]

                try:
                    index = port_str.index("-")
                except ValueError:
                    fragment.append(port_str)
                else:
                    fragment.append({"range": [port_str[:index], port_str[index+1:]]})

            elif format in ["ip", "net"]:
                if '-' in entry_tokens[i]:
                    fragment.append({"range": entry_tokens[i].split('-') })
                else:
                    try:
                        index = entry_tokens[i].index("/")
                    except ValueError:
                        addr = entry_tokens[i]
                        if "family" in obj.options and obj.options["family"] == "inet6":
                            addr = normalizeIP6(addr)
                        fragment.append(addr)
                    else:
                        addr = entry_tokens[i][:index]
                        if "family" in obj.options and obj.options["family"] == "inet6":
                            addr = normalizeIP6(addr)
                        fragment.append({"prefix": {"addr": addr,
                                                    "len": int(entry_tokens[i][index+1:])}})
            else:
                fragment.append(entry_tokens[i])
        return [{"concat": fragment}] if len(type_format) > 1 else fragment

    def build_set_add_rules(self, name, entry):
        rules = []
        element = self._set_entry_fragment(name, entry)
        rules.append({"add": {"element": {"family": "inet",
                                          "table": TABLE_NAME,
                                          "name": name,
                                          "elem": element}}})
        return rules

    def set_add(self, name, entry):
        rules = self.build_set_add_rules(name, entry)
        self.set_rules(rules, self._fw.get_log_denied())

    def set_delete(self, name, entry):
        element = self._set_entry_fragment(name, entry)
        rule = {"delete": {"element": {"family": "inet",
                                       "table": TABLE_NAME,
                                       "name": name,
                                       "elem": element}}}
        self.set_rule(rule, self._fw.get_log_denied())

    def build_set_flush_rules(self, name):
        return [{"flush": {"set": {"family": "inet",
                                   "table": TABLE_NAME,
                                   "name": name}}}]

    def set_flush(self, name):
        rules = self.build_set_flush_rules(name)
        self.set_rules(rules, self._fw.get_log_denied())

    def _set_get_family(self, name):
        ipset = self._fw.ipset.get_ipset(name)

        if ipset.type == "hash:mac":
            family = "ether"
        elif ipset.options and "family" in ipset.options \
             and ipset.options["family"] == "inet6":
            family = "ip6"
        else:
            family = "ip"

        return family

    def set_restore(self, set_name, type_name, entries,
                    create_options=None, entry_options=None):
        rules = []
        rules.extend(self.build_set_create_rules(set_name, type_name, create_options))
        rules.extend(self.build_set_flush_rules(set_name))

        # avoid large memory usage by chunking the entries
        chunk = 0
        for entry in entries:
            rules.extend(self.build_set_add_rules(set_name, entry))
            chunk += 1
            if chunk >= 1000:
                self.set_rules(rules, self._fw.get_log_denied())
                rules.clear()
                chunk = 0
        else:
            self.set_rules(rules, self._fw.get_log_denied())
