feat: add network scanner module with nmap discovery, config merge, and ping

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend/modules/network_scanner.py

@@ -0,0 +1,78 @@
+import asyncio
+import subprocess
+from typing import Any
+
+
+class NetworkScanner:
+    def __init__(self, subnet: str):
+        self.subnet = subnet
+
+    def scan(self) -> dict[str, Any]:
+        import nmap
+        nm = nmap.PortScanner()
+        nm.scan(hosts=self.subnet, arguments="-sn")
+        return {"scan": dict(nm._scan_result.get("scan", {}))}
+
+    def parse_scan_results(self, scan_data: dict[str, Any]) -> list[dict[str, Any]]:
+        nodes = []
+        for ip, data in scan_data.get("scan", {}).items():
+            hostnames = data.get("hostnames", [{}])
+            hostname = hostnames[0].get("name", "") if hostnames else ""
+            vendors = data.get("vendor", {})
+            vendor = next(iter(vendors.values()), "") if vendors else ""
+            nodes.append({
+                "ip": ip,
+                "hostname": hostname,
+                "status": data.get("status", {}).get("state", "unknown"),
+                "vendor": vendor,
+            })
+        nodes.sort(key=lambda n: tuple(int(p) for p in n["ip"].split(".")))
+        return nodes
+
+    def merge_with_config(
+        self,
+        discovered: list[dict[str, Any]],
+        configured: list[dict[str, Any]],
+    ) -> list[dict[str, Any]]:
+        config_by_ip = {n["ip"]: n for n in configured}
+        merged = []
+        seen_ips = set()
+
+        for node in discovered:
+            ip = node["ip"]
+            seen_ips.add(ip)
+            if ip in config_by_ip:
+                entry = {**config_by_ip[ip], **{"status": node["status"], "auto_discovered": True}}
+            else:
+                entry = {
+                    "name": node["hostname"] or ip,
+                    "ip": ip,
+                    "status": node["status"],
+                    "vendor": node.get("vendor", ""),
+                    "icon": "device",
+                    "auto_discovered": True,
+                    "connections": [],
+                }
+            merged.append(entry)
+
+        for node in configured:
+            if node["ip"] not in seen_ips:
+                merged.append({**node, "status": "unknown", "auto_discovered": False})
+
+        return merged
+
+    async def ping_host(self, ip: str) -> bool:
+        try:
+            proc = await asyncio.create_subprocess_exec(
+                "ping", "-c", "1", "-W", "1", ip,
+                stdout=subprocess.DEVNULL,
+                stderr=subprocess.DEVNULL,
+            )
+            code = await proc.wait()
+            return code == 0
+        except Exception:
+            return False
+
+    async def ping_all(self, ips: list[str]) -> dict[str, bool]:
+        results = await asyncio.gather(*[self.ping_host(ip) for ip in ips])
+        return dict(zip(ips, results))