refactor: DNS

dns/client_log.go

@@ -0,0 +1,69 @@
+package dns
+
+import (
+	"context"
+	"strings"
+
+	"github.com/sagernet/sing/common/logger"
+
+	"github.com/miekg/dns"
+)
+
+func logCachedResponse(logger logger.ContextLogger, ctx context.Context, response *dns.Msg, ttl int) {
+	if logger == nil || len(response.Question) == 0 {
+		return
+	}
+	domain := FqdnToDomain(response.Question[0].Name)
+	logger.DebugContext(ctx, "cached ", domain, " ", dns.RcodeToString[response.Rcode], " ", ttl)
+	for _, recordList := range [][]dns.RR{response.Answer, response.Ns, response.Extra} {
+		for _, record := range recordList {
+			logger.InfoContext(ctx, "cached ", dns.Type(record.Header().Rrtype).String(), " ", FormatQuestion(record.String()))
+		}
+	}
+}
+
+func logExchangedResponse(logger logger.ContextLogger, ctx context.Context, response *dns.Msg, ttl uint32) {
+	if logger == nil || len(response.Question) == 0 {
+		return
+	}
+	domain := FqdnToDomain(response.Question[0].Name)
+	logger.DebugContext(ctx, "exchanged ", domain, " ", dns.RcodeToString[response.Rcode], " ", ttl)
+	for _, recordList := range [][]dns.RR{response.Answer, response.Ns, response.Extra} {
+		for _, record := range recordList {
+			logger.InfoContext(ctx, "exchanged ", dns.Type(record.Header().Rrtype).String(), " ", FormatQuestion(record.String()))
+		}
+	}
+}
+
+func logRejectedResponse(logger logger.ContextLogger, ctx context.Context, response *dns.Msg) {
+	if logger == nil || len(response.Question) == 0 {
+		return
+	}
+	for _, recordList := range [][]dns.RR{response.Answer, response.Ns, response.Extra} {
+		for _, record := range recordList {
+			logger.InfoContext(ctx, "rejected ", dns.Type(record.Header().Rrtype).String(), " ", FormatQuestion(record.String()))
+		}
+	}
+}
+
+func FqdnToDomain(fqdn string) string {
+	if dns.IsFqdn(fqdn) {
+		return fqdn[:len(fqdn)-1]
+	}
+	return fqdn
+}
+
+func FormatQuestion(string string) string {
+	for strings.HasPrefix(string, ";") {
+		string = string[1:]
+	}
+	string = strings.ReplaceAll(string, "\t", " ")
+	string = strings.ReplaceAll(string, "\n", " ")
+	string = strings.ReplaceAll(string, ";; ", " ")
+	string = strings.ReplaceAll(string, "; ", " ")
+
+	for strings.Contains(string, "  ") {
+		string = strings.ReplaceAll(string, "  ", " ")
+	}
+	return strings.TrimSpace(string)
+}