Files
homelable/backend/app/services/scanner.py
Pouzor 057891f7d5 feat: add stop scan button in UI with backend cancellation support
- POST /scan/{run_id}/stop endpoint signals running scan to cancel
- Scanner checks cancellation flag between CIDR ranges and hosts, exits early
- Cancelled scans get status 'cancelled' instead of 'done'
- Stop button (red StopCircle) shown in Scan History panel for running scans
- 6 new backend tests, 5 new frontend tests
2026-04-01 14:18:44 +02:00

229 lines
8.1 KiB
Python

"""Network scanner: ARP sweep + nmap service detection."""
import asyncio
import logging
import socket
from datetime import datetime, timezone
from typing import Any
from sqlalchemy.ext.asyncio import AsyncSession
from app.db.models import Node, PendingDevice, ScanRun
from app.services.fingerprint import fingerprint_ports, suggest_node_type
logger = logging.getLogger(__name__)
# Run IDs that have been requested to cancel
_cancelled_runs: set[str] = set()
def request_cancel(run_id: str) -> None:
"""Signal a running scan to stop early."""
_cancelled_runs.add(run_id)
def _is_cancelled(run_id: str) -> bool:
return run_id in _cancelled_runs
try:
import nmap
_NMAP_AVAILABLE = True
except ImportError:
_NMAP_AVAILABLE = False
logger.warning("python-nmap not available — scanner will run in mock mode")
def _nmap_scan(target: str) -> list[dict[str, Any]]:
"""Run nmap -sV --open on target, return list of host dicts."""
if not _NMAP_AVAILABLE:
return _mock_scan(target)
nm = nmap.PortScanner()
try:
# Home lab port range: standard top-1000 + common self-hosted service ports
extra_ports = (
"80,443,22,21,23,25,53,110,143,161,162,179,389,445,548,"
"554,636,873,1883,1880,1935,2020,2375,2376,3000,3001,3306,"
"3389,4711,5000,5001,5432,5601,5900,5984,6052,6379,6432,6443,"
"6767,6789,6800,7878,8000,8006,8080,8081,8086,8088,8090,8096,"
"8112,8123,8200,8291,8428,8443,8554,8686,8789,8843,8880,8883,"
"8971,8989,9000,9001,9090,9091,9092,9093,9100,9117,9200,9300,"
"9411,9443,9696,10051,16686,34567,37777,51413,64738"
)
nm.scan(hosts=target, arguments=f"-sV --open -T4 --host-timeout 120s -p {extra_ports}")
except Exception as exc:
logger.error("nmap scan failed: %s", exc)
raise RuntimeError(str(exc)) from exc
hosts = []
for host in nm.all_hosts():
if nm[host].state() != "up":
continue
open_ports = []
for proto in nm[host].all_protocols():
for port, info in nm[host][proto].items():
if info["state"] == "open":
open_ports.append({
"port": port,
"protocol": proto,
"banner": info.get("product", "") + " " + info.get("version", ""),
})
hosts.append({
"ip": host,
"hostname": _resolve_hostname(host),
"mac": nm[host].get("addresses", {}).get("mac"),
"os": _extract_os(nm, host),
"open_ports": open_ports,
})
return hosts
def _resolve_hostname(ip: str) -> str | None:
try:
return socket.gethostbyaddr(ip)[0]
except Exception:
return None
def _extract_os(nm: object, host: str) -> str | None:
try:
osmatch = nm[host].get("osmatch", []) # type: ignore[index]
if osmatch:
return str(osmatch[0]["name"])
except Exception:
pass
return None
def _mock_scan(target: str) -> list[dict[str, Any]]:
"""Return fake results for dev/test environments without nmap."""
return [
{
"ip": "192.168.1.99",
"hostname": "unknown-device.lan",
"mac": "AA:BB:CC:DD:EE:FF",
"os": None,
"open_ports": [
{"port": 80, "protocol": "tcp", "banner": "nginx"},
{"port": 22, "protocol": "tcp", "banner": "OpenSSH 9.0"},
],
}
]
async def run_scan(ranges: list[str], db: AsyncSession, run_id: str) -> None:
"""Execute scan for given CIDR ranges and populate pending_devices."""
# Avoid circular import
from sqlalchemy import select
from app.api.routes.status import broadcast_scan_update
devices_found = 0
try:
# Clean up stale pending devices whose IPs are already in the canvas
# (covers devices approved between scans, or pre-existing canvas nodes)
canvas_ips_result = await db.execute(select(Node.ip).where(Node.ip.isnot(None)))
canvas_ips = {row[0] for row in canvas_ips_result.fetchall()}
if canvas_ips:
stale_result = await db.execute(
select(PendingDevice).where(
PendingDevice.status == "pending",
PendingDevice.ip.in_(canvas_ips),
)
)
for stale in stale_result.scalars().all():
await db.delete(stale)
await db.commit()
for cidr in ranges:
if _is_cancelled(run_id):
break
# Run nmap in a thread pool — does not block the event loop
hosts = await asyncio.to_thread(_nmap_scan, cidr)
for host in hosts:
if _is_cancelled(run_id):
break
ip = host["ip"]
# Skip if device is already in the canvas (approved node)
canvas_result = await db.execute(
select(Node).where(Node.ip == ip)
)
if canvas_result.scalar_one_or_none() is not None:
logger.debug("Skipping %s — already in canvas", ip)
continue
# Skip if device was explicitly hidden by the user
hidden_result = await db.execute(
select(PendingDevice).where(
PendingDevice.ip == ip,
PendingDevice.status == "hidden",
)
)
if hidden_result.scalar_one_or_none() is not None:
logger.debug("Skipping %s — hidden by user", ip)
continue
services = fingerprint_ports(host["open_ports"])
suggested_type = suggest_node_type(host["open_ports"], host.get("mac"))
# Update existing pending device or create a new one
existing_result = await db.execute(
select(PendingDevice).where(
PendingDevice.ip == ip,
PendingDevice.status == "pending",
)
)
existing = existing_result.scalar_one_or_none()
if existing:
existing.mac = host.get("mac") or existing.mac
existing.hostname = host.get("hostname") or existing.hostname
existing.os = host.get("os") or existing.os
existing.services = services
existing.suggested_type = suggested_type
else:
device = PendingDevice(
ip=ip,
mac=host.get("mac"),
hostname=host.get("hostname"),
os=host.get("os"),
services=services,
suggested_type=suggested_type,
status="pending",
)
db.add(device)
devices_found += 1
# Commit immediately so the device is visible right away
await db.commit()
# Update running count on the scan run record
run = await db.get(ScanRun, run_id)
if run:
run.devices_found = devices_found
await db.commit()
# Push WS event so the frontend refreshes pending panel
await broadcast_scan_update(run_id=run_id, devices_found=devices_found)
# Mark scan as done or cancelled
run = await db.get(ScanRun, run_id)
if run:
run.status = "cancelled" if _is_cancelled(run_id) else "done"
run.devices_found = devices_found
run.finished_at = datetime.now(timezone.utc)
await db.commit()
except Exception as exc:
logger.error("Scan failed: %s", exc)
run = await db.get(ScanRun, run_id)
if run:
run.status = "error"
run.error = str(exc)
run.finished_at = datetime.now(timezone.utc)
await db.commit()
finally:
_cancelled_runs.discard(run_id)