refactor(discovery): use ping for discovery and fill MAC via SSH

auto-check/pkg/discovery/scanner.go

@@ -1,61 +1,88 @@
 package discovery
 
 import (
+	"context"
 	"fmt"
 	"net"
 	"os/exec"
-	"runtime"
+	"strings"
+	"sync"
 	"time"
 
 	"auto-check/pkg/model"
 )
 
-// Scanner 网段扫描器（串行，按顺序逐个探测）
+// Scanner 网段扫描器（并发 ping 探测）
 type Scanner struct {
-	CIDR    string
-	Timeout time.Duration
+	CIDR        string
+	Timeout     time.Duration // 单 IP 探测超时
+	Concurrency int           // 并发数，默认 30
 }
 
 // NewScanner 创建扫描器
-func NewScanner(cidr string, timeout time.Duration) *Scanner {
+func NewScanner(cidr string, timeout time.Duration, concurrency int) *Scanner {
+	if concurrency <= 0 {
+		concurrency = 10
+	}
 	return &Scanner{
-		CIDR:    cidr,
-		Timeout: timeout,
+		CIDR:        cidr,
+		Timeout:     timeout,
+		Concurrency: concurrency,
 	}
 }
 
-// Scan 扫描网段，返回存活设备列表（含 MAC 地址）
-// 串行逐个探测，每个 IP 有超时保护
+// Scan 并发 ping 扫描网段，返回存活设备列表（仅含 IP，MAC 留空待 SSH 阶段回填）
 func (s *Scanner) Scan() []model.Device {
 	ips, ok := s.candidateIPs()
 	if !ok {
 		return nil
 	}
-	fmt.Printf("[扫描] 网段 %s，共 %d 个IP，开始探测...\n", s.CIDR, len(ips))
+	fmt.Printf("[扫描] 网段 %s，共 %d 个IP，%d 并发 ping 探测...\n", s.CIDR, len(ips), s.Concurrency)
 
-	var results []model.Device
-	for _, ip := range ips {
-		if dev, ok := s.probe(ip); ok {
-			results = append(results, dev)
-		}
+	jobs := make(chan string, len(ips))
+	results := make(chan model.Device, len(ips))
+
+	var wg sync.WaitGroup
+	for i := 0; i < s.Concurrency; i++ {
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			for ip := range jobs {
+				if s.ping(ip) {
+					results <- model.Device{IP: ip, MAC: ""}
+				}
+			}
+		}()
 	}
 
-	fmt.Printf("[扫描] 完成，发现 %d 台存活设备\n", len(results))
-	return results
+	for _, ip := range ips {
+		jobs <- ip
+	}
+	close(jobs)
+
+	wg.Wait()
+	close(results)
+
+	var devices []model.Device
+	for dev := range results {
+		devices = append(devices, dev)
+	}
+
+	fmt.Printf("[扫描] 完成，发现 %d 台存活设备\n", len(devices))
+	return devices
 }
 
 // candidateIPs 解析网段并生成候选 IP 列表（排除网络地址和广播地址）
-func (s *Scanner) candidateIPs() ([]net.IP, bool) {
-	ip, ipnet, err := net.ParseCIDR(s.CIDR)
+func (s *Scanner) candidateIPs() ([]string, bool) {
+	_, ipnet, err := net.ParseCIDR(s.CIDR)
 	if err != nil {
 		fmt.Printf("[扫描] 网段解析失败: %v\n", err)
 		return nil, false
 	}
-	var ips []net.IP
-	for ip := ip.Mask(ipnet.Mask); ipnet.Contains(ip); inc(ip) {
-		dst := make(net.IP, len(ip))
-		copy(dst, ip)
-		ips = append(ips, dst)
+	ip := ipnet.IP.Mask(ipnet.Mask)
+	var ips []string
+	for ; ipnet.Contains(ip); inc(ip) {
+		ips = append(ips, ip.String())
 	}
 	if len(ips) > 2 {
 		ips = ips[1 : len(ips)-1]
@@ -63,39 +90,47 @@ func (s *Scanner) candidateIPs() ([]net.IP, bool) {
 	return ips, true
 }
 
-// probe 探测单个 IP，存活则返回设备信息（MAC 通过 ARP 表查询）
-func (s *Scanner) probe(ip net.IP) (model.Device, bool) {
-	if !s.isAlive(ip) {
-		return model.Device{}, false
+// ping 探测单个 IP 是否存活（ICMP，经系统 ping 命令）。
+// 仅凭 exit code 不可靠（Windows 在某些代答/虚拟网卡场景会返回 0），
+// 因此解析输出，要求至少收到 1 个回包。
+func (s *Scanner) ping(ip string) bool {
+	// ping 命令的等待超时（毫秒）：固定 1s 足够局域网探测
+	const pingWait = 1000
+	// context 超时设为 ping 等待的 2 倍，留足 ping 自然退出时间，
+	// 避免 context 先于 ping -w 杀进程导致拿不到输出。
+	ctx, cancel := context.WithTimeout(context.Background(), 2*pingWait*time.Millisecond)
+	defer cancel()
+	cmd := exec.CommandContext(ctx, "ping", "-n", "1", "-w", fmt.Sprintf("%d", pingWait), ip)
+	out, err := cmd.Output()
+	if err != nil {
+		return false
 	}
-	mac := lookupMAC(ip.String())
-	desc := "无MAC"
-	if mac != "" {
-		desc = mac
-	}
-	fmt.Printf("  [+] %s 存活 (MAC: %s)\n", ip, desc)
-	return model.Device{IP: ip.String(), MAC: mac}, true
+	return parsePingReply(string(out))
 }
 
-// isAlive 用 ping 探测单个 IP 是否存活（内置超时保护）
-func (s *Scanner) isAlive(ip net.IP) bool {
-	waitMs := s.Timeout.Milliseconds()
-	if waitMs < 1000 {
-		waitMs = 1000
+// parsePingReply 判断 ping 输出是否表示存活
+func parsePingReply(out string) bool {
+	for _, line := range strings.Split(out, "\n") {
+		l := strings.ToLower(strings.TrimSpace(line))
+		// Windows: "Packets: Sent = 1, Received = 1, Lost = 0"
+		if strings.Contains(l, "received =") {
+			i := strings.Index(l, "received =")
+			n := strings.TrimSpace(l[i+len("received ="):])
+			// 取数字前缀
+			cnt := 0
+			for _, c := range n {
+				if c < '0' || c > '9' {
+					break
+				}
+				cnt = cnt*10 + int(c-'0')
+			}
+			return cnt >= 1
+		}
 	}
-	var args []string
-	switch runtime.GOOS {
-	case "windows":
-		args = []string{"-n", "1", "-w", fmt.Sprintf("%d", waitMs), ip.String()}
-	case "darwin":
-		args = []string{"-c", "1", "-W", fmt.Sprintf("%d", waitMs), ip.String()}
-	default:
-		args = []string{"-c", "1", "-W", fmt.Sprintf("%d", waitMs/1000), ip.String()}
-	}
-	return exec.Command("ping", args...).Run() == nil
+	return false
 }
 
-// inc IP 递增
+// inc IP 递增（原地修改，调用方负责复制）
 func inc(ip net.IP) {
 	for j := len(ip) - 1; j >= 0; j-- {
 		ip[j]++