feat: remote dns for sing

core/sing/dns.go

@@ -0,0 +1,81 @@
+package sing
+
+import (
+	"bytes"
+	"github.com/InazumaV/V2bX/api/panel"
+	"github.com/goccy/go-json"
+	log "github.com/sirupsen/logrus"
+	"os"
+	"strings"
+)
+
+func updateDNSConfig(node *panel.NodeInfo) (err error) {
+	dnsPath := os.Getenv("SING_DNS_PATH")
+	if len(node.RawDNS.DNSJson) != 0 {
+		err = saveDnsConfig(node.RawDNS.DNSJson, dnsPath)
+	} else if len(node.RawDNS.DNSMap) != 0 {
+		dnsConfig := DNSConfig{
+			Servers: []map[string]interface{}{
+				{
+					"tag":     "default",
+					"address": "https://8.8.8.8/dns-query",
+					"detour":  "direct",
+				},
+			},
+		}
+		for id, value := range node.RawDNS.DNSMap {
+			dnsConfig.Servers = append(dnsConfig.Servers,
+				map[string]interface{}{
+					"tag":              id,
+					"address":          value["address"],
+					"address_resolver": "default",
+					"detour":           "direct",
+				},
+			)
+			rule := map[string]interface{}{
+				"server":        id,
+				"disable_cache": true,
+			}
+			for _, ruleType := range []string{"domain_suffix", "domain_keyword", "domain_regex", "geosite"} {
+				var domains []string
+				for _, v := range value["domains"].([]string) {
+					split := strings.SplitN(v, ":", 2)
+					prefix := strings.ToLower(split[0])
+					if prefix == ruleType || (prefix == "domain" && ruleType == "domain_suffix") {
+						if len(split) > 1 {
+							domains = append(domains, split[1])
+						}
+						if len(domains) > 0 {
+							rule[ruleType] = domains
+						}
+					}
+				}
+			}
+			dnsConfig.Rules = append(dnsConfig.Rules, rule)
+		}
+		dnsConfigJSON, err := json.MarshalIndent(dnsConfig, "", "  ")
+		if err != nil {
+			log.WithField("err", err).Error("Error marshaling dnsConfig to JSON")
+			return err
+		}
+		err = saveDnsConfig(dnsConfigJSON, dnsPath)
+	}
+	return err
+}
+
+func saveDnsConfig(dns []byte, dnsPath string) (err error) {
+	currentData, err := os.ReadFile(dnsPath)
+	if err != nil {
+		log.WithField("err", err).Error("Failed to read SING_DNS_PATH")
+		return err
+	}
+	if !bytes.Equal(currentData, dns) {
+		if err = os.Truncate(dnsPath, 0); err != nil {
+			log.WithField("err", err).Error("Failed to clear SING DNS PATH file")
+		}
+		if err = os.WriteFile(dnsPath, dns, 0644); err != nil {
+			log.WithField("err", err).Error("Failed to write DNS to SING DNS PATH file")
+		}
+	}
+	return err
+}