firegex-traffic-viewer/backend/routers/firewall.py

import sqlite3
from fastapi import APIRouter, HTTPException
from pydantic import BaseModel
from utils.sqlite import SQLite
from utils import ip_parse, ip_family, refactor_name, refresh_frontend, PortType
from utils.models import ResetRequest, StatusMessageModel
from modules.firewall.nftables import FiregexTables
from modules.firewall.firewall import FirewallManager

class RuleModel(BaseModel):
    active: bool
    name: str
    proto: str
    ip_src: str
    ip_dst: str
    port_src_from: PortType
    port_dst_from: PortType
    port_src_to: PortType
    port_dst_to: PortType
    action: str
    mode:str
    
class RuleAddResponse(BaseModel):
    status:str|list[dict]

class RenameForm(BaseModel):
    name:str

class GeneralStatModel(BaseModel):
    rules: int

app = APIRouter()

db = SQLite('db/firewall-rules.db', {
    'rules': {
        'rule_id': 'INT PRIMARY KEY CHECK (rule_id >= 0)',
        'mode': 'VARCHAR(1) NOT NULL CHECK (mode IN ("O", "I"))', # O = out, I = in, B = both
        'name': 'VARCHAR(100) NOT NULL',
        'active' : 'BOOLEAN NOT NULL CHECK (active IN (0, 1))',
        'proto': 'VARCHAR(3) NOT NULL CHECK (proto IN ("tcp", "udp", "any"))',
        'ip_src': 'VARCHAR(100) NOT NULL',
        'port_src_from': 'INT CHECK(port_src_from > 0 and port_src_from < 65536)',
        'port_src_to': 'INT CHECK(port_src_to > 0 and port_src_to < 65536 and port_src_from <= port_src_to)',
        'ip_dst': 'VARCHAR(100) NOT NULL',
        'port_dst_from': 'INT CHECK(port_dst_from > 0 and port_dst_from < 65536)',
        'port_dst_to': 'INT CHECK(port_dst_to > 0 and port_dst_to < 65536 and port_dst_from <= port_dst_to)',
        'action': 'VARCHAR(10) NOT NULL CHECK (action IN ("accept", "drop", "reject"))',
    },
    'QUERY':[
        "CREATE UNIQUE INDEX IF NOT EXISTS unique_rules ON rules (proto, ip_src, ip_dst, port_src_from, port_src_to, port_dst_from, port_dst_to, mode);"
    ]
})

async def reset(params: ResetRequest):
    if not params.delete: 
        db.backup()
    await firewall.close()
    FiregexTables().reset()
    if params.delete:
        db.delete()
        db.init()
    else:
        db.restore()
    await firewall.init()
    

async def startup():
    db.init()
    await firewall.init()

async def shutdown():
    db.backup()
    await firewall.close()
    db.disconnect()
    db.restore()

async def apply_changes():
    await firewall.reload()
    await refresh_frontend()
    return {'status': 'ok'}

firewall = FirewallManager(db)

@app.get('/stats', response_model=GeneralStatModel)
async def get_general_stats():
    """Get firegex general status about rules"""
    return db.query("SELECT (SELECT COUNT(*) FROM rules) rules")[0]

@app.get('/rules', response_model=list[RuleModel])
async def get_rule_list():
    """Get the list of existent firegex rules"""
    return db.query("SELECT active, name, proto, ip_src, ip_dst, port_src_from, port_dst_from, port_src_to, port_dst_to, action, mode FROM rules ORDER BY rule_id;")

@app.get('/rule/{rule_id}/disable', response_model=StatusMessageModel)
async def service_disable(rule_id: str):
    """Request disabling a specific rule"""
    if len(db.query('SELECT 1 FROM rules WHERE rule_id = ?;', rule_id)) == 0:
        return {'status': 'Rule not found'}
    db.query('UPDATE rules SET active = 0 WHERE rule_id = ?;', rule_id)
    return await apply_changes()

@app.get('/rule/{rule_id}/enable', response_model=StatusMessageModel)
async def service_start(rule_id: str):
    """Request the enabling a specific rule"""
    if len(db.query('SELECT 1 FROM rules WHERE rule_id = ?;', rule_id)) == 0:
        return {'status': 'Rule not found'}
    db.query('UPDATE rules SET active = 1 WHERE rule_id = ?;', rule_id)
    return await apply_changes()

@app.post('/service/{rule_id}/rename', response_model=StatusMessageModel)
async def service_rename(rule_id: str, form: RenameForm):
    """Request to change the name of a specific service"""
    if len(db.query('SELECT 1 FROM rules WHERE rule_id = ?;', rule_id)) == 0:
        return {'status': 'Rule not found'}
    form.name = refactor_name(form.name)
    if not form.name: return {'status': 'The name cannot be empty!'} 
    try:
        db.query('UPDATE rules SET name=? WHERE rule_id = ?;', form.name, rule_id)
    except sqlite3.IntegrityError:
        return {'status': 'This name is already used'}
    await refresh_frontend()
    return {'status': 'ok'}

def parse_and_check_rule(rule:RuleModel):
    try:
        rule.ip_src = ip_parse(rule.ip_src)
        rule.ip_dst = ip_parse(rule.ip_dst)
    except ValueError:
        return {"status":"Invalid address"}
    
    rule.port_dst_from, rule.port_dst_to = min(rule.port_dst_from, rule.port_dst_to), max(rule.port_dst_from, rule.port_dst_to)
    rule.port_src_from, rule.port_src_to = min(rule.port_src_from, rule.port_src_to), max(rule.port_src_from, rule.port_src_to)
    
    if ip_family(rule.ip_dst) != ip_family(rule.ip_src):
        return  {"status":"Destination and source addresses must be of the same family"}
    if rule.proto not in ["tcp", "udp", "any"]:
        return {"status":"Invalid protocol"}
    if rule.action not in ["accept", "drop", "reject"]:
        return {"status":"Invalid action"}
    return rule
    

@app.post('/rules/set', response_model=RuleAddResponse)
async def add_new_service(form: list[RuleModel]):
    """Add a new service"""
    form = [parse_and_check_rule(ele) for ele in form]
    errors = [({"rule":i} | ele) for i, ele in enumerate(form) if isinstance(ele, dict)]
    if len(errors) > 0:
        return {'status': errors}
    try:
        db.queries(["DELETE FROM rules"]+
            [("""
              INSERT INTO rules (
                  rule_id, active, name,
                  proto,
                  ip_src, ip_dst,
                  port_src_from, port_dst_from,
                  port_src_to, port_dst_to,
                  action, mode
            ) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ? ,?, ?)""",
                rid, ele.active, ele.name,
                ele.proto,
                ele.ip_src, ele.ip_dst,
                ele.port_src_from, ele.port_dst_from,
                ele.port_src_to, ele.port_dst_to,
                ele.action, ele.mode
            ) for rid, ele in enumerate(form)]
        )
    except sqlite3.IntegrityError:
        return {'status': 'Error saving the rules: maybe there are duplicated rules'}
    return await apply_changes()