Add network scan page (arp-scan)

New /scan page lists all active devices on the subnet (ARP scan):
- 静态绑定: matches a host declaration
- 动态分配: matches a dhcpd.leases entry
- 未知 / 外部: nothing matches (manually configured or from other DHCP server)

Click '转为静态绑定' to convert a discovered device to a static host binding.

Also includes:
- arp-scan wrapper in dhcp_ops.py (get_local_network, arp_scan, classify_devices)
- /scan route with optional auto-refresh every 30s
- README updated with arp-scan install step + new feature bullet

README.md

@@ -9,10 +9,11 @@
 - 🟢 静态绑定（host）：MAC + 固定 IP + 主机名
 - 🟢 监听接口配置（INTERFACESv4）
 - 🟢 租约查询（按 IP/MAC/主机名搜索）+ 地址池使用率
+- 🟢 网络扫描（arp-scan）：列出网段内活跃设备，标记 静态绑定 / 动态分配 / 未知
 - 🟢 服务状态 + reload / restart + 语法检查
 - 🟢 操作日志（谁在什么时间做了什么）
 - 🟢 用户名密码登录 + 改密
-- 🟢 所有变更自动：写文件 → 备份 → `dhcpd -t` 语法检查 → `systemctl reload isc-dhcp-server`
+- 🟢 所有变更自动：写文件 → 备份 → `dhcpd -t` 语法检查 → `systemctl restart isc-dhcp-server`（带 is-active 验证）
 
 ## 文件结构
 
@@ -30,7 +31,7 @@ dhcp-service/
 ## 安装
 
 ```bash
-apt-get install -y isc-dhcp-server  # 后端 DHCP 服务
+apt-get install -y isc-dhcp-server arp-scan dhcping  # 后端 DHCP 服务 + 扫描工具
 pip3 install -r requirements.txt --break-system-packages
 ```
 

app.py

@@ -459,6 +459,34 @@ def lease_list():
     return render_template("leases.html", leases=leases, q=q)
 
 
+# ---------- 网络扫描 (arp-scan) ----------
+
+@app.route("/scan", methods=["GET", "POST"])
+@login_required
+def scan():
+    """网络扫描 - 用 arp-scan 列出网段内所有活跃设备"""
+    ifaces = dhcp_ops.get_interfaces()
+    iface = request.values.get("iface") or (ifaces[0] if ifaces else "enp0s31f6-ovs")
+    network = request.values.get("network") or dhcp_ops.get_local_network(iface)
+
+    devices = []
+    scan_msg = ""
+    did_scan = False
+
+    if request.method == "POST" or request.args.get("auto") == "1":
+        did_scan = True
+        ok, scan_msg, devices = dhcp_ops.arp_scan(iface, network)
+        if ok:
+            # 交叉 dhcpd.leases 和 host 静态绑定
+            hosts = get_hosts()
+            leases = dhcp_ops.parse_leases()
+            devices = dhcp_ops.classify_devices(devices, hosts, leases)
+
+    return render_template("scan.html",
+                           ifaces=ifaces, iface=iface, network=network,
+                           devices=devices, scan_msg=scan_msg, did_scan=did_scan)
+
+
 # ---------- config (interfaces + 原始 conf) ----------
 
 @app.route("/config", methods=["GET", "POST"])

dhcp_ops.py

@@ -515,4 +515,91 @@ def get_service_status() -> Dict:
         info["status_text"] = "\n".join(info["status_text"][:5])
     except (subprocess.TimeoutExpired, FileNotFoundError):
         pass
-    return info
+    return info
+
+
+# ---------------------------------------------------------------------------
+# 网络扫描（arp-scan）
+# ---------------------------------------------------------------------------
+
+@dataclass
+class ArpDevice:
+    ip: str
+    mac: str
+    vendor: str = ""
+    source: str = ""   # 标记：static / dynamic / unknown
+
+
+def get_local_network(iface: str = "enp0s31f6-ovs") -> Optional[str]:
+    """从指定接口的 IPv4 地址 + 掩码计算出 /24 网络号"""
+    try:
+        out = subprocess.run(
+            ["ip", "-4", "-o", "addr", "show", "dev", iface],
+            capture_output=True, text=True, timeout=5,
+        ).stdout
+        # 形如: "4: enp0s31f6-ovs    inet 10.168.1.209/24 brd 10.168.1.255 scope global enp0s31f6-ovs\"
+        import re as _re
+        m = _re.search(r"inet\s+(\d+\.\d+\.\d+\.\d+)/(\d+)", out)
+        if not m:
+            return None
+        ip, prefix = m.group(1), int(m.group(2))
+        if prefix != 24:
+            # 仅支持 /24 扫描；其他掩码返回 None 让 UI 提示用户
+            return None
+        return ".".join(ip.split(".")[:3]) + ".0/24"
+    except Exception:
+        return None
+
+
+def arp_scan(iface: str = "enp0s31f6-ovs", network: Optional[str] = None,
+             timeout: int = 10) -> Tuple[bool, str, List[ArpDevice]]:
+    """
+    扫描指定接口/网段，返回 (ok, msg, devices)。
+    - 用 arp-scan（系统二进制）
+    - 如果传 network=None，自动从 iface 推算
+    """
+    if network is None:
+        network = get_local_network(iface) or "10.168.1.0/24"
+
+    cmd = ["arp-scan", f"--interface={iface}", "--numeric", "--quiet", "--retry=1",
+           "--timeout=" + str(timeout * 1000), network]
+    try:
+        r = subprocess.run(cmd, capture_output=True, text=True, timeout=timeout + 5)
+        if r.returncode not in (0, 1):  # arp-scan: 0=全部收到, 1=部分收到
+            return False, (r.stderr or r.stdout).strip(), []
+    except FileNotFoundError:
+        return False, "未安装 arp-scan（apt-get install arp-scan）", []
+    except subprocess.TimeoutExpired:
+        return False, "arp-scan 超时", []
+
+    devices: List[ArpDevice] = []
+    for line in r.stdout.splitlines():
+        line = line.strip()
+        if not line or line.startswith("Interface:") or "arp-scan" in line or "packets" in line:
+            continue
+        parts = line.split()
+        if len(parts) >= 2 and "." in parts[0] and ":" in parts[1]:
+            devices.append(ArpDevice(ip=parts[0], mac=parts[1].lower()))
+    msg = f"扫描完成，发现 {len(devices)} 个设备"
+    return True, msg, devices
+
+
+def classify_devices(devices: List[ArpDevice], hosts, leases) -> List[ArpDevice]:
+    """
+    给设备打标记：
+    - static: 在静态绑定（host 声明）里
+    - dynamic: 在 dhcpd.leases 里
+    - unknown: 都不在（手动配的或别处 DHCP 给的）
+    """
+    static_macs = {h.mac.lower() for h in hosts}
+    static_ips = {h.ip for h in hosts}
+    lease_macs = {l.mac.lower() for l in leases if l.mac}
+    lease_ips = {l.ip for l in leases}
+    for d in devices:
+        if d.mac in static_macs or d.ip in static_ips:
+            d.source = "static"
+        elif d.mac in lease_macs or d.ip in lease_ips:
+            d.source = "dynamic"
+        else:
+            d.source = "unknown"
+    return devices

templates/base.html

@@ -16,6 +16,7 @@
             <a href="{{ url_for('subnet_list') }}" class="{% if request.endpoint in ['subnet_list','subnet_new','subnet_edit'] %}active{% endif %}">子网</a>
             <a href="{{ url_for('host_list') }}" class="{% if request.endpoint in ['host_list','host_new','host_edit'] %}active{% endif %}">静态绑定</a>
             <a href="{{ url_for('lease_list') }}" class="{% if request.endpoint=='lease_list' %}active{% endif %}">租约</a>
+            <a href="{{ url_for('scan') }}" class="{% if request.endpoint=='scan' %}active{% endif %}">扫描</a>
             <a href="{{ url_for('config_view') }}" class="{% if request.endpoint=='config_view' %}active{% endif %}">服务配置</a>
             {% if is_admin %}
             <a href="{{ url_for('log_list') }}" class="{% if request.endpoint=='log_list' %}active{% endif %}">日志</a>

templates/scan.html

@@ -0,0 +1,110 @@
+{% extends "base.html" %}
+{% block title %}网络扫描{% endblock %}
+{% block content %}
+<div class="page-head">
+    <h1>网络扫描</h1>
+    <span class="muted small">用 arp-scan 列出网段内活跃设备</span>
+</div>
+
+<div class="card">
+    <form method="post" class="form-inline">
+        <label>接口
+            <select name="iface">
+                {% for i in ifaces %}
+                <option value="{{ i }}" {% if i==iface %}selected{% endif %}>{{ i }}</option>
+                {% endfor %}
+                {% if not ifaces %}
+                <option value="{{ iface }}">{{ iface }}</option>
+                {% endif %}
+            </select>
+        </label>
+        <label>网段
+            <input type="text" name="network" value="{{ network or '' }}" placeholder="10.168.1.0/24">
+        </label>
+        <button type="submit" class="btn btn-primary">扫描</button>
+        <label class="checkbox-row" style="margin-left:12px">
+            <input type="checkbox" id="autoRefresh" checked>
+            自动刷新（30 秒）
+        </label>
+    </form>
+    {% if did_scan %}
+    <p class="muted small" style="margin-top:8px">{{ scan_msg }}</p>
+    {% endif %}
+</div>
+
+{% if did_scan %}
+<div class="card">
+    <h2>扫描结果（{{ devices|length }} 个设备）</h2>
+    {% if devices %}
+    <table class="data-table">
+        <thead>
+            <tr>
+                <th>IP</th>
+                <th>MAC</th>
+                <th>来源</th>
+                <th>操作</th>
+            </tr>
+        </thead>
+        <tbody>
+        {% for d in devices %}
+        <tr>
+            <td><code>{{ d.ip }}</code></td>
+            <td><code>{{ d.mac }}</code></td>
+            <td>
+                {% if d.source == 'static' %}
+                    <span class="badge badge-ok">静态绑定</span>
+                {% elif d.source == 'dynamic' %}
+                    <span class="badge badge-warn">动态分配</span>
+                {% else %}
+                    <span class="badge">未知 / 外部</span>
+                {% endif %}
+            </td>
+            <td class="actions">
+                {% if d.source != 'static' and is_admin %}
+                <form method="post" action="{{ url_for('host_new') }}" style="display:inline">
+                    <input type="hidden" name="mac" value="{{ d.mac }}">
+                    <input type="hidden" name="ip" value="{{ d.ip }}">
+                    <input type="hidden" name="name" value="dev-{{ d.ip|replace('.', '-') }}">
+                    <button type="submit" class="btn btn-sm">转为静态绑定</button>
+                </form>
+                {% endif %}
+            </td>
+        </tr>
+        {% endfor %}
+        </tbody>
+    </table>
+    <p class="muted small">
+        说明：「静态绑定」= 在 Web 静态绑定（host 声明）里；
+        「动态分配」= 在 dhcpd.leases 里被分配过；
+        「未知/外部」= 不在上述两类（可能手动配的或别的 DHCP 服务器给的）。
+    </p>
+    {% else %}
+    <p class="muted">未发现活跃设备（网段内无应答）</p>
+    {% endif %}
+</div>
+{% else %}
+<div class="card empty">
+    <p>点击「扫描」开始 ARP 扫描。</p>
+    <p class="muted small">提示：扫描时会向网段每个 IP 发 ARP 请求，3-5 秒完成。</p>
+</div>
+{% endif %}
+
+<script>
+let timer = null;
+function setupAutoRefresh() {
+    const cb = document.getElementById('autoRefresh');
+    if (!cb) return;
+    if (timer) clearTimeout(timer);
+    if (!cb.checked) return;
+    // 只在已经扫过一次的情况下自动刷新
+    if (document.querySelector('table.data-table')) {
+        timer = setTimeout(() => {
+            const f = document.querySelector('form.form-inline');
+            if (f) f.submit();
+        }, 30000);
+    }
+}
+document.addEventListener('DOMContentLoaded', setupAutoRefresh);
+document.getElementById('autoRefresh')?.addEventListener('change', setupAutoRefresh);
+</script>
+{% endblock %}