adding firewall function to firegex!

backend/modules/firewall/nftables.py

@@ -0,0 +1,88 @@
+from modules.firewall.models import Rule
+from utils import nftables_int_to_json, ip_parse, ip_family, NFTableManager, nftables_json_to_int
+
+
+class FiregexHijackRule():
+    def __init__(self, proto:str, ip_src:str, ip_dst:str, port_src_from:int, port_dst_from:int, port_src_to:int, port_dst_to:int, action:str, target:str, id:int):
+        self.id = id
+        self.target = target
+        self.proto = proto
+        self.ip_src = ip_src
+        self.ip_dst = ip_dst
+        self.port_src_from = min(port_src_from, port_src_to)
+        self.port_dst_from = min(port_dst_from, port_dst_to)
+        self.port_src_to = max(port_src_from, port_src_to)
+        self.port_dst_to = max(port_dst_from, port_dst_to)
+        self.action = action
+
+    def __eq__(self, o: object) -> bool:
+        if isinstance(o, FiregexHijackRule) or isinstance(o, Rule):
+            return self.action == o.action and self.proto == o.proto and\
+                ip_parse(self.ip_src) == ip_parse(o.ip_src) and ip_parse(self.ip_dst) == ip_parse(o.ip_dst) and\
+                int(self.port_src_from) == int(o.port_src_from) and int(self.port_dst_from) == int(o.port_dst_from) and\
+                int(self.port_src_to) == int(o.port_src_to) and int(self.port_dst_to) == int(o.port_dst_to)
+        return False
+
+
+class FiregexTables(NFTableManager):
+    rules_chain_in = "firewall_rules_in"
+    rules_chain_out = "firewall_rules_out"
+    
+    def __init__(self):
+        super().__init__([
+            {"add":{"chain":{
+                "family":"inet",
+                "table":self.table_name,
+                "name":self.rules_chain_in,
+                "type":"filter",
+                "hook":"prerouting",
+                "prio":-300,
+                "policy":"accept"
+            }}},
+            {"add":{"chain":{
+                "family":"inet",
+                "table":self.table_name,
+                "name":self.rules_chain_out,
+                "type":"filter",
+                "hook":"postrouting",
+                "prio":-300,
+                "policy":"accept"
+            }}},    
+        ],[
+            {"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}}},
+        ])
+    
+    def delete_all(self):
+        self.cmd(
+            {"flush":{"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}}},
+        )
+    
+    def set(self, srv:list[Rule]):
+        self.delete_all()
+        for ele in srv: self.add(ele)
+
+    def add(self, srv:Rule):
+        port_filters = []
+        if srv.proto != "any":
+            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': {'payload': {'protocol': str(srv.proto), 'field': 'sport'}}, 'op': '!=', 'right': 0}}) #filter the protocol if no port is specified
+                
+        self.cmd({ "insert":{ "rule": {
+            "family": "inet",
+            "table": self.table_name,
+            "chain": self.rules_chain_out if srv.output_mode else self.rules_chain_in,
+            "expr": [
+                    {'match': {'left': {'payload': {'protocol': ip_family(srv.ip_src), 'field': 'saddr'}}, 'op': '==', 'right': nftables_int_to_json(srv.ip_src)}},
+                    {'match': {'left': {'payload': {'protocol': ip_family(srv.ip_dst), 'field': 'daddr'}}, 'op': '==', 'right': nftables_int_to_json(srv.ip_dst)}},
+                ] + port_filters + [{'accept': None} if srv.action == "accept" else {'reject': {}} if srv.action == "reject" else {'drop': None}]
+        }}})