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firegex-traffic-viewer/backend/modules/firewall/nftables.py
Domingo Dirutigliano 71edfc29c4 Firewall refactor
2023-09-28 20:45:58 +02:00

149 lines
7.8 KiB
Python

from modules.firewall.models import Rule, Protocol, Mode, Action
from utils import nftables_int_to_json, ip_family, NFTableManager, is_ip_parse
import copy
class FiregexTables(NFTableManager):
rules_chain_in = "firewall_rules_in"
rules_chain_out = "firewall_rules_out"
rules_chain_fwd = "firewall_rules_fwd"
def init_comands(self, policy:str=Action.ACCEPT, allow_loopback=False, allow_established=False, allow_icmp=False):
return [
{"add":{"chain":{
"family":"inet",
"table":self.table_name,
"name":self.rules_chain_in,
"type":"filter",
"hook":"prerouting",
"prio":0,
"policy":policy
}}},
{"add":{"chain":{
"family":"inet",
"table":self.table_name,
"name":self.rules_chain_fwd,
"type":"filter",
"hook":"forward",
"prio":0,
"policy":policy
}}},
{"add":{"chain":{
"family":"inet",
"table":self.table_name,
"name":self.rules_chain_out,
"type":"filter",
"hook":"postrouting",
"prio":0,
"policy":Action.ACCEPT
}}},
] + ([
{ "add":{ "rule": {
"family": "inet", "table": self.table_name, "chain": self.rules_chain_out,
"expr": [{ "match": { "op": "==", "left": { "meta": { "key": "iif" }}, "right": "lo"}},{"accept": None}]
}}},
{ "add":{ "rule": {
"family": "inet", "table": self.table_name, "chain": self.rules_chain_in,
"expr": [{ "match": { "op": "==", "left": { "meta": { "key": "iif" }}, "right": "lo"}},{"accept": None}]
}}}
] if allow_loopback else []) + ([
{ "add":{ "rule": {
"family": "inet", "table": self.table_name, "chain": self.rules_chain_in,
"expr": [{ "match": {"op": "in", "left": { "ct": { "key": "state" }},"right": ["established"]} }, { "accept": None }]
}}}
] if allow_established else []) + ([
{ "add":{ "rule": {
"family": "inet", "table": self.table_name, "chain": self.rules_chain_in,
"expr": [{ "match": { "op": "==", "left": { "meta": { "key": "l4proto" } }, "right": "icmp"} }, { "accept": None }]
}}},
{ "add":{ "rule": {
"family": "inet", "table": self.table_name, "chain": self.rules_chain_fwd,
"expr": [{ "match": { "op": "==", "left": { "meta": { "key": "l4proto" } }, "right": "icmp"} }, { "accept": None }]
}}},
{ "add":{ "rule": {
"family": "inet", "table": self.table_name, "chain": self.rules_chain_in,
"expr": [{ "match": { "op": "==", "left": { "meta": { "key": "l4proto" } }, "right": "ipv6-icmp"} }, { "accept": None }]
}}},
{ "add":{ "rule": {
"family": "inet", "table": self.table_name, "chain": self.rules_chain_fwd,
"expr": [{ "match": { "op": "==", "left": { "meta": { "key": "l4proto" } }, "right": "ipv6-icmp"} }, { "accept": None }]
}}}
] if allow_icmp else [])
def __init__(self):
super().__init__(self.init_comands(),[
{"flush":{"chain":{"table":self.table_name,"family":"inet", "name":self.rules_chain_in}}},
{"delete":{"chain":{"table":self.table_name,"family":"inet", "name":self.rules_chain_in}}},
{"flush":{"chain":{"table":self.table_name,"family":"inet", "name":self.rules_chain_out}}},
{"delete":{"chain":{"table":self.table_name,"family":"inet", "name":self.rules_chain_out}}},
{"flush":{"chain":{"table":self.table_name,"family":"inet", "name":self.rules_chain_fwd}}},
{"delete":{"chain":{"table":self.table_name,"family":"inet", "name":self.rules_chain_fwd}}},
])
def set(self, srvs:list[Rule], policy:str="accept", allow_loopback=False, allow_established=False, allow_icmp=False):
srvs = list(srvs)
self.reset()
if policy == Action.REJECT:
policy = Action.DROP
srvs.append(Rule(
proto=Protocol.ANY,
src="",
dst="",
port_src_from=1,
port_dst_from=1,
port_src_to=65535,
port_dst_to=65535,
action=Action.REJECT,
mode=Mode.IN
))
rules = self.init_comands(policy, allow_loopback=allow_loopback, allow_established=allow_established, allow_icmp=allow_icmp) + self.get_rules(*srvs)
self.cmd(*rules)
def get_rules(self,*srvs:Rule):
rules = []
final_srvs:list[Rule] = []
for ele in srvs:
if ele.proto == Protocol.BOTH:
udp_rule = copy.deepcopy(ele)
udp_rule.proto = Protocol.UDP.value
ele.proto = Protocol.TCP.value
final_srvs.append(udp_rule)
final_srvs.append(ele)
for srv in final_srvs:
ip_filters = []
if srv.src != "":
if is_ip_parse(srv.src):
ip_filters.append({'match': {'left': {'payload': {'protocol': ip_family(srv.src), 'field': 'saddr'}}, 'op': '==', 'right': nftables_int_to_json(srv.src)}})
else:
ip_filters.append({"match": { "op": "==", "left": { "meta": { "key": "iifname" } }, "right": srv.src} })
if srv.dst != "":
if is_ip_parse(srv.dst):
ip_filters.append({'match': {'left': {'payload': {'protocol': ip_family(srv.dst), 'field': 'daddr'}}, 'op': '==', 'right': nftables_int_to_json(srv.dst)}})
else:
ip_filters.append({"match": { "op": "==", "left": { "meta": { "key": "oifname" } }, "right": srv.dst} })
port_filters = []
if not srv.proto in [Protocol.ANY, Protocol.BOTH]:
if srv.port_src_from != 1 or srv.port_src_to != 65535: #Any Port
port_filters.append({'match': {'left': {'payload': {'protocol': str(srv.proto), 'field': 'sport'}}, 'op': '>=', 'right': int(srv.port_src_from)}})
port_filters.append({'match': {'left': {'payload': {'protocol': str(srv.proto), 'field': 'sport'}}, 'op': '<=', 'right': int(srv.port_src_to)}})
if srv.port_dst_from != 1 or srv.port_dst_to != 65535: #Any Port
port_filters.append({'match': {'left': {'payload': {'protocol': str(srv.proto), 'field': 'dport'}}, 'op': '>=', 'right': int(srv.port_dst_from)}})
port_filters.append({'match': {'left': {'payload': {'protocol': str(srv.proto), 'field': 'dport'}}, 'op': '<=', 'right': int(srv.port_dst_to)}})
if len(port_filters) == 0:
port_filters.append({'match': {'left': {'meta': {'key': 'l4proto'}}, 'op': '==', 'right': srv.proto}}) #filter the protocol if no port is specified
end_rules = [{'accept': None} if srv.action == "accept" else {'reject': {}} if (srv.action == "reject" and not srv.output_mode) else {'drop': None}]
rules.append({ "add":{ "rule": {
"family": "inet",
"table": self.table_name,
"chain": self.rules_chain_out if srv.output_mode else self.rules_chain_in if srv.input_mode else self.rules_chain_fwd,
"expr": ip_filters + port_filters + end_rules
#If srv.output_mode is True, then the rule is in the output chain, so the reject action is not allowed
}}})
return rules
def add(self, *srvs:Rule):
self.cmd(*self.get_rules(*srvs))