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// Copyright 2019 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 DISCOVERY_MDNS_MDNS_READER_H_
#define DISCOVERY_MDNS_MDNS_READER_H_
#include <utility>
#include <vector>
#include "discovery/mdns/mdns_records.h"
#include "platform/base/error.h"
#include "util/big_endian.h"
namespace openscreen {
namespace discovery {
struct Config;
class MdnsReader : public BigEndianReader {
public:
MdnsReader(const Config& config, const uint8_t* buffer, size_t length);
using BigEndianReader::Read;
// The following methods return true if the method was able to successfully
// read the value to |out| and advances current() to point right past the read
// data. Returns false if the method failed to read the value to |out|,
// current() remains unchanged.
bool Read(TxtRecordRdata::Entry* out);
bool Read(DomainName* out);
bool Read(RawRecordRdata* out);
bool Read(SrvRecordRdata* out);
bool Read(ARecordRdata* out);
bool Read(AAAARecordRdata* out);
bool Read(PtrRecordRdata* out);
bool Read(TxtRecordRdata* out);
bool Read(NsecRecordRdata* out);
// Reads a DNS resource record with its RDATA.
// The correct type of RDATA to be read is determined by the type
// specified in the record.
bool Read(MdnsRecord* out);
bool Read(MdnsQuestion* out);
// Reads multiple mDNS questions and records that are a part of
// a mDNS message being read.
ErrorOr<MdnsMessage> Read();
private:
struct NsecBitMapField {
uint8_t window_block;
uint8_t bitmap_length;
const uint8_t* bitmap;
};
bool Read(IPAddress::Version version, IPAddress* out);
bool Read(DnsType type, Rdata* out);
bool Read(Header* out);
bool Read(std::vector<DnsType>* types, int remaining_length);
bool Read(NsecBitMapField* out);
template <class ItemType>
bool Read(uint16_t count, std::vector<ItemType>* out) {
Cursor cursor(this);
out->reserve(count);
for (uint16_t i = 0; i < count; ++i) {
ItemType entry;
if (!Read(&entry)) {
return false;
}
out->emplace_back(std::move(entry));
}
cursor.Commit();
return true;
}
template <class RdataType>
bool Read(Rdata* out) {
RdataType rdata;
if (Read(&rdata)) {
*out = std::move(rdata);
return true;
}
return false;
}
// Maximum allowed size for the rdata in any received record.
const size_t kMaximumAllowedRdataSize;
};
} // namespace discovery
} // namespace openscreen
#endif // DISCOVERY_MDNS_MDNS_READER_H_