feat: initial commit

backend/app/scanner.py

@@ -0,0 +1,100 @@
+from __future__ import annotations
+
+import asyncio
+import ipaddress
+import socket
+from typing import Any
+
+from .state import NetworkState, utc_now
+
+COMMON_PORTS = (22, 53, 80, 443, 8291)
+VENDOR_HINTS = {
+    "mikrotik": "MikroTik",
+    "cisco": "Cisco",
+    "ubiquiti": "Ubiquiti",
+    "raspberry": "Raspberry Pi",
+}
+
+
+def guess_device_type(hostname: str | None, open_port: int | None) -> str:
+    if not hostname and open_port is None:
+        return "unknown"
+
+    hn = (hostname or "").lower()
+    if "rb4011" in hn or "router" in hn:
+        return "router"
+    if "crs" in hn or "switch" in hn or "slm" in hn:
+        return "switch"
+    if "cap" in hn or "ap" in hn or "wifi" in hn:
+        return "ap"
+
+    if open_port == 8291:
+        return "mikrotik"
+    if open_port == 53:
+        return "dns"
+    return "client"
+
+
+def guess_vendor(hostname: str | None) -> str | None:
+    if not hostname:
+        return None
+    hn = hostname.lower()
+    for token, vendor in VENDOR_HINTS.items():
+        if token in hn:
+            return vendor
+    return None
+
+
+async def probe_host(ip: str, timeout: float) -> tuple[bool, int | None]:
+    for port in COMMON_PORTS:
+        try:
+            conn = asyncio.open_connection(ip, port)
+            reader, writer = await asyncio.wait_for(conn, timeout=timeout)
+            writer.close()
+            await writer.wait_closed()
+            return True, port
+        except Exception:
+            continue
+    return False, None
+
+
+def reverse_dns(ip: str) -> str | None:
+    try:
+        return socket.gethostbyaddr(ip)[0]
+    except Exception:
+        return None
+
+
+async def scan_subnet(
+    state: NetworkState,
+    subnet_cidr: str,
+    timeout_seconds: float,
+    concurrency: int,
+) -> set[str]:
+    network = ipaddress.ip_network(subnet_cidr, strict=False)
+    active: set[str] = set()
+    sem = asyncio.Semaphore(concurrency)
+
+    async def one(ip_obj: Any) -> None:
+        ip = str(ip_obj)
+        async with sem:
+            is_up, port = await probe_host(ip, timeout_seconds)
+            if not is_up:
+                return
+            hostname = reverse_dns(ip)
+            active.add(ip)
+            await state.upsert_device(
+                ip,
+                {
+                    "hostname": hostname,
+                    "name": hostname or ip,
+                    "type": guess_device_type(hostname, port),
+                    "vendor": guess_vendor(hostname),
+                    "status": "online",
+                    "last_seen": utc_now(),
+                    "source": "scanner",
+                },
+            )
+
+    await asyncio.gather(*(one(ip) for ip in network.hosts()))
+    return active