Limited NSEC support to RecordParsed

net/dns/record_rdata.h

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef NET_DNS_RECORD_RDATA_H_
 #define NET_DNS_RECORD_RDATA_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 163 matching lines @@
   const std::vector<std::string>& texts() const { return texts_; }
 
  private:
   TxtRecordRdata();
 
   std::vector<std::string> texts_;
 
   DISALLOW_COPY_AND_ASSIGN(TxtRecordRdata);
 };
 
+// Only the subset of the nsec record format required by mDNS is supported.
+// Nsec (limited) record format (http://www.ietf.org/rfc/rfc3845.txt and
+//                               http://www.rfc-editor.org/rfc/rfc6762.txt):
+// next-domain (ignored): A domain name.
+// one bit-map:
+//     - one byte zeroed out to represent the zeroth window
+//     - one byte from 0-32 representing the length of the bitmap in bytes
+//     - the bitmap, each bit representing whether or not the record
+//     corresponding to the bit number exists for that domain.
+class NET_EXPORT_PRIVATE NsecRecordRdata : public RecordRdata {
+ public:
+  static const uint16 kType = dns_protocol::kTypeNSEC;
+
+  virtual ~NsecRecordRdata();
+  static scoped_ptr<NsecRecordRdata> Create(const base::StringPiece& data,
+                                            const DnsRecordParser& parser);
+  virtual bool IsEqual(const RecordRdata* other) const OVERRIDE;
+  virtual uint16 Type() const OVERRIDE;
+
+  const std::vector<uint8>& bitmap() { return bitmap_; }
+
+  // Returns bit i-th bit in the bitmap, where bits withing a byte are organized
+  // most to least significant.
+  bool GetBit(unsigned i);
+
+ private:
+  NsecRecordRdata();
+
+  std::vector<uint8> bitmap_;
+
+  DISALLOW_COPY_AND_ASSIGN(NsecRecordRdata);
+};
+
+
 }  // namespace net
 
 #endif  // NET_DNS_RECORD_RDATA_H_