feat: complete basic functions

Support http,dns and mysql connection. Support custom http, dns response. Support dns rebinding.
Support mysql load local files and jdbc deserialize exploit.

internal/newdns/set.go

@@ -0,0 +1,71 @@
+package newdns
+
+import (
+	"time"
+
+	"github.com/pkg/errors"
+)
+
+// Set is a set of records.
+type Set struct {
+	// The FQDN of the set.
+	Name string
+
+	// The type of the record.
+	Type Type
+
+	// The records in the set.
+	Records []Record
+
+	// The TTL of the set.
+	//
+	// Default: 5m.
+	TTL time.Duration
+}
+
+// Validate will validate the set and ensure defaults.
+func (s *Set) Validate() error {
+	// check name
+	if !IsDomain(s.Name, true) {
+		return errors.Errorf("invalid name: %s", s.Name)
+	}
+
+	// check type
+	if !s.Type.valid() {
+		return errors.Errorf("invalid type: %d", s.Type)
+	}
+
+	// check records
+	if len(s.Records) == 0 {
+		return errors.Errorf("missing records")
+	}
+
+	// check CNAME records
+	if s.Type == CNAME && len(s.Records) > 1 {
+		return errors.Errorf("multiple CNAME records")
+	}
+
+	// validate records
+	for _, record := range s.Records {
+		err := record.Validate(s.Type)
+		if err != nil {
+			return errors.Wrap(err, "invalid record")
+		}
+	}
+
+	// check for duplicate addresses if not TXT
+	if len(s.Records) > 1 && s.Type != TXT {
+		for i := 0; i < len(s.Records)-1; i++ {
+			if s.Records[i].Address == s.Records[i+1].Address {
+				return errors.Errorf("duplicate address: %s", s.Records[i].Address)
+			}
+		}
+	}
+
+	// set default ttl
+	if s.TTL == 0 {
+		s.TTL = 5 * time.Minute
+	}
+
+	return nil
+}