sysctl managmento for port hijacking

backend/app.py

@@ -7,12 +7,18 @@ from jose import jwt
 from passlib.context import CryptContext
 from fastapi_socketio import SocketManager
 from utils.sqlite import SQLite
-from utils import API_VERSION, FIREGEX_PORT, JWT_ALGORITHM, get_interfaces, refresh_frontend, DEBUG
+from utils import API_VERSION, FIREGEX_PORT, JWT_ALGORITHM, get_interfaces, refresh_frontend, DEBUG, SysctlManager
 from utils.loader import frontend_deploy, load_routers
 from utils.models import ChangePasswordModel, IpInterface, PasswordChangeForm, PasswordForm, ResetRequest, StatusModel, StatusMessageModel
 
 # DB init
 db = SQLite('db/firegex.db')
+sysctl = SysctlManager({
+    "net.ipv4.conf.all.forwarding": True,
+    "net.ipv6.conf.all.forwarding": True,
+    "net.ipv4.conf.all.route_localnet": True,
+    "net.ipv4.ip_forward": True
+})
 
 oauth2_scheme = OAuth2PasswordBearer(tokenUrl="/api/login", auto_error=False)
 crypto = CryptContext(schemes=["bcrypt"], deprecated="auto")
@@ -114,6 +120,7 @@ async def startup_event():
     db.init()
     if os.getenv("HEX_SET_PSW"):
         set_psw(bytes.fromhex(os.getenv("HEX_SET_PSW")).decode())
+    sysctl.set()
     await startup()
     if not JWT_SECRET(): db.put("secret", secrets.token_hex(32))
     await refresh_frontend()
@@ -121,6 +128,7 @@ async def startup_event():
 @app.on_event("shutdown")
 async def shutdown_event():
     await shutdown()
+    sysctl.reset()
     db.disconnect()
 
 @api.post('/reset', response_model=StatusMessageModel)
@@ -130,6 +138,7 @@ async def reset_firegex(form: ResetRequest):
         db.delete()
         db.init()
         db.put("secret", secrets.token_hex(32))
+    sysctl.set()
     await reset(form)
     await refresh_frontend()
     return {'status': 'ok'}

backend/utils/__init__.py

@@ -29,6 +29,34 @@ def refactor_name(name:str):
     while "  " in name: name = name.replace("  "," ")
     return name
 
+class SysctlManager:
+    def __init__(self, ctl_table):
+        self.old_table = {}
+        self.new_table = {}
+        if os.path.isdir("/sys_host/"):
+            self.old_table = dict()
+            self.new_table = dict(ctl_table)
+            for name in ctl_table.keys():
+                self.old_table[name] = read_sysctl(name)
+    
+    def write_table(self, table):
+        for name, value in table.items():
+            write_sysctl(name, value)
+
+    def set(self):
+        self.write_table(self.new_table)
+
+    def reset(self):
+        self.write_table(self.old_table)
+
+def read_sysctl(name:str):
+    with open(f"/sys_host/{name}", "rt") as f:
+        return "1" in f.read()
+
+def write_sysctl(name:str, value:bool):
+    with open(f"/sys_host/{name}", "wt") as f:
+        f.write("1" if value else "0")
+
 def list_files(mypath):
     from os import listdir
     from os.path import isfile, join

start.py

@@ -4,6 +4,7 @@ import argparse, sys, platform, os, multiprocessing, subprocess, getpass
 
 pref = "\033["
 reset = f"{pref}0m"
+composefile = "firegex-compose.yml"
 
 class colors:
     black = "30m"
@@ -72,6 +73,65 @@ args = parser.parse_args()
 os.chdir(os.path.dirname(os.path.realpath(__file__)))
 run_checks()
 
+def write_compose(psw_set=None):
+    with open(composefile,"wt") as compose:
+
+        if "linux" in sys.platform and not 'microsoft-standard' in platform.uname().release: #Check if not is a wsl also
+             compose.write(f"""
+version: '3.9'
+
+services:
+    firewall:
+        restart: unless-stopped
+        container_name: firegex
+        {"build: ." if args.build else "image: ghcr.io/pwnzer0tt1/firegex"}
+        network_mode: "host"
+        environment:
+            - PORT={args.port}
+            - NTHREADS={args.threads}
+            {"- HEX_SET_PSW="+psw_set.encode().hex() if psw_set else ""}
+        volumes:
+            - /execute/db
+            - type: bind
+              source: /proc/sys/net/ipv4/conf/all/route_localnet
+              target: /sys_host/net.ipv4.conf.all.route_localnet
+            - type: bind
+              source: /proc/sys/net/ipv4/ip_forward
+              target: /sys_host/net.ipv4.ip_forward
+            - type: bind
+              source: /proc/sys/net/ipv4/conf/all/forwarding
+              target: /sys_host/net.ipv4.conf.all.forwarding
+            - type: bind
+              source: /proc/sys/net/ipv6/conf/all/forwarding
+              target: /sys_host/net.ipv6.conf.all.forwarding
+        cap_add:
+            - NET_ADMIN
+""")
+
+        else:
+            sep()
+            puts("--- WARNING ---", color=colors.yellow)
+            puts("You are not in a linux machine, due to docker limitation on other platform, the firewall will not work in this machine. You will only see the interface of firegex.", color=colors.red)
+            compose.write(f"""
+version: '3.9'
+
+services:
+    firewall:
+        restart: unless-stopped
+        container_name: firegex
+        {"build: ." if args.build else "image: ghcr.io/pwnzer0tt1/firegex"}
+        ports:
+            - {args.port}:{args.port}
+        environment:
+            - PORT={args.port}
+            - NTHREADS={args.threads}
+            {"- HEX_SET_PSW="+psw_set.encode().hex() if psw_set else ""}
+        volumes:
+            - /execute/db
+        cap_add:
+            - NET_ADMIN
+""")
+
 start_operation = not (args.stop or args.restart)
 
 if args.build and not os.path.isfile("./Dockerfile"):
@@ -81,9 +141,12 @@ if args.build and not os.path.isfile("./Dockerfile"):
 if args.threads < 1:
     args.threads = multiprocessing.cpu_count()
 
-if start_operation:
+if start_operation and (not args.build or args.keep):
     if check_if_exists("docker ps --filter 'name=^firegex$' --no-trunc | grep firegex"):
-        puts("Firegex is already running! use --help to see options useful to manage firegex execution", color=colors.yellow)
+        if args.keep:
+            write_compose()
+        else:
+            puts("Firegex is already running! use --help to see options useful to manage firegex execution", color=colors.yellow)
         exit()
     sep()
     puts(f"Firegex", color=colors.yellow, end="")
@@ -105,53 +168,8 @@ if start_operation:
             else:
                 break
 
-composefile = "firegex-compose.yml"
+write_compose(psw_set)
 
-with open(composefile,"wt") as compose:
-
-    if "linux" in sys.platform and not 'microsoft-standard' in platform.uname().release: #Check if not is a wsl also
-        compose.write(f"""
-version: '3.9'
-
-services:
-    firewall:
-        restart: unless-stopped
-        container_name: firegex
-        {"build: ." if args.build else "image: ghcr.io/pwnzer0tt1/firegex"}
-        network_mode: "host"
-        environment:
-            - PORT={args.port}
-            - NTHREADS={args.threads}
-            {"- HEX_SET_PSW="+psw_set.encode().hex() if psw_set else ""}
-        volumes:
-            - /execute/db
-        cap_add:
-            - NET_ADMIN
-""")
-
-    else:
-        sep()
-        puts("--- WARNING ---", color=colors.yellow)
-        puts("You are not in a linux machine, due to docker limitation on other platform, the firewall will not work in this machine. You will only see the interface of firegex.", color=colors.red)
-        compose.write(f"""
-version: '3.9'
-
-services:
-    firewall:
-        restart: unless-stopped
-        container_name: firegex
-        {"build: ." if args.build else "image: ghcr.io/pwnzer0tt1/firegex"}
-        ports:
-            - {args.port}:{args.port}
-        environment:
-            - PORT={args.port}
-            - NTHREADS={args.threads}
-            {"- HEX_SET_PSW="+psw_set.encode().hex() if psw_set else ""}
-        volumes:
-            - /execute/db
-        cap_add:
-            - NET_ADMIN
-""")
 sep()
 if not args.no_autostart:
     try: