chore: sync local changes (2026-03-12)

mengyaping-backend/utils/dns.go

@@ -0,0 +1,60 @@
+package utils
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+	"net"
+	"net/http"
+	"net/url"
+	"time"
+)
+
+const dnsAPIBase = "https://cf-dns.smyhub.com/api/dns?domain="
+
+type dnsResponse struct {
+	Status string   `json:"status"`
+	IPv4   []string `json:"ipv4"`
+	IPv6   []string `json:"ipv6"`
+}
+
+// ResolveDomainIPs 通过 DNS API 解析域名的 IPv4 + IPv6 地址
+func ResolveDomainIPs(rawURL string) ([]string, error) {
+	parsed, err := url.Parse(rawURL)
+	if err != nil {
+		return nil, err
+	}
+
+	hostname := parsed.Hostname()
+	if hostname == "" {
+		return nil, fmt.Errorf("no hostname in URL")
+	}
+
+	if net.ParseIP(hostname) != nil {
+		return []string{hostname}, nil
+	}
+
+	client := &http.Client{Timeout: 10 * time.Second}
+	resp, err := client.Get(dnsAPIBase + hostname)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+
+	body, err := io.ReadAll(io.LimitReader(resp.Body, 1024*10))
+	if err != nil {
+		return nil, err
+	}
+
+	var dnsResp dnsResponse
+	if err := json.Unmarshal(body, &dnsResp); err != nil {
+		return nil, err
+	}
+
+	if dnsResp.Status != "success" {
+		return nil, fmt.Errorf("DNS lookup failed for %s", hostname)
+	}
+
+	ips := append(dnsResp.IPv4, dnsResp.IPv6...)
+	return ips, nil
+}