1 files changed, 109 insertions, 0 deletions
diff --git a/att script/3 (v6 DDoS)/code/辅助权威服务器/plugin/plugin.go b/att script/3 (v6 DDoS)/code/辅助权威服务器/plugin/plugin.go
new file mode 100644
index 0000000..3153b58
--- /dev/null
+++ b/att script/3 (v6 DDoS)/code/辅助权威服务器/plugin/plugin.go
@@ -0,0 +1,109 @@
+package plugin
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"github.com/miekg/dns"
+	ot "github.com/opentracing/opentracing-go"
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+type (
+	// Plugin 是一个中间层，它定义了一个插件传递链，前一个 Handler 处理完成之后将紧接着传递到下一个 Handler。
+	Plugin func(Handler) Handler
+
+	// Handler is like dns.Handler except ServeDNS may return an rcode
+	// and/or error.
+	//
+	// If ServeDNS writes to the response body, it should return a status
+	// code. CoreDNS assumes *no* reply has yet been written if the status
+	// code is one of the following:
+	//
+	// * SERVFAIL (dns.RcodeServerFailure)
+	//
+	// * REFUSED (dns.RecodeRefused)
+	//
+	// * FORMERR (dns.RcodeFormatError)
+	//
+	// * NOTIMP (dns.RcodeNotImplemented)
+	//
+	// All other response codes signal other handlers above it that the
+	// response message is already written, and that they should not write
+	// to it also.
+	//
+	// If ServeDNS encounters an error, it should return the error value
+	// so it can be logged by designated error-handling plugin.
+	//
+	// If writing a response after calling another ServeDNS method, the
+	// returned rcode SHOULD be used when writing the response.
+	//
+	// If handling errors after calling another ServeDNS method, the
+	// returned error value SHOULD be logged or handled accordingly.
+	//
+	// Otherwise, return values should be propagated down the plugin
+	// chain by returning them unchanged.
+	Handler interface {
+		ServeDNS(context.Context, dns.ResponseWriter, *dns.Msg) (int, error)
+		Name() string
+	}
+
+	// HandlerFunc is a convenience type like dns.HandlerFunc, except
+	// ServeDNS returns an rcode and an error. See Handler
+	// documentation for more information.
+	HandlerFunc func(context.Context, dns.ResponseWriter, *dns.Msg) (int, error)
+)
+
+// ServeDNS implements the Handler interface.
+func (f HandlerFunc) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
+	return f(ctx, w, r)
+}
+
+// Name implements the Handler interface.
+func (f HandlerFunc) Name() string { return "handlerfunc" }
+
+// Error returns err with 'plugin/name: ' prefixed to it.
+func Error(name string, err error) error { return fmt.Errorf("%s/%s: %s", "plugin", name, err) }
+
+// NextOrFailure calls next.ServeDNS when next is not nil, otherwise it will return, a ServerFailure and a `no next plugin found` error.
+func NextOrFailure(name string, next Handler, ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) { // nolint: golint
+	if next != nil {
+		if span := ot.SpanFromContext(ctx); span != nil {
+			child := span.Tracer().StartSpan(next.Name(), ot.ChildOf(span.Context()))
+			defer child.Finish()
+			ctx = ot.ContextWithSpan(ctx, child)
+		}
+		return next.ServeDNS(ctx, w, r)
+	}
+
+	return dns.RcodeServerFailure, Error(name, errors.New("no next plugin found"))
+}
+
+// ClientWrite returns true if the response has been written to the client.
+// Each plugin to adhere to this protocol.
+func ClientWrite(rcode int) bool {
+	switch rcode {
+	case dns.RcodeServerFailure:
+		fallthrough
+	case dns.RcodeRefused:
+		fallthrough
+	case dns.RcodeFormatError:
+		fallthrough
+	case dns.RcodeNotImplemented:
+		return false
+	}
+	return true
+}
+
+// Namespace is the namespace used for the metrics.
+const Namespace = "ohmydns2"
+
+// 普罗米修斯监控
+// TimeBuckets is based on Prometheus client_golang prometheus.DefBuckets
+var TimeBuckets = prometheus.ExponentialBuckets(0.00025, 2, 16) // from 0.25ms to 8 seconds
+
+// SlimTimeBuckets is low cardinality set of duration buckets.
+var SlimTimeBuckets = prometheus.ExponentialBuckets(0.00025, 10, 5) // from 0.25ms to 2.5 seconds
+
+// ErrOnce is returned when a plugin doesn't support multiple setups per server.
+var ErrOnce = errors.New("this plugin can only be used once per Server Block")