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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef mozilla_net_DNSPacket_h__
#define mozilla_net_DNSPacket_h__
#include "mozilla/Maybe.h"
#include "mozilla/Result.h"
#include "pk11pub.h"
#include "ScopedNSSTypes.h"
#include "nsClassHashtable.h"
#include "nsIDNSService.h"
namespace mozilla {
namespace net {
class DOHresp {
public:
nsresult Add(uint32_t TTL, unsigned char const* dns, unsigned int index,
uint16_t len, bool aLocalAllowed);
nsTArray<NetAddr> mAddresses;
uint32_t mTtl = UINT32_MAX;
};
// the values map to RFC1035 type identifiers
enum TrrType {
TRRTYPE_A = 1,
TRRTYPE_NS = 2,
TRRTYPE_CNAME = 5,
TRRTYPE_AAAA = 28,
TRRTYPE_OPT = 41,
TRRTYPE_TXT = 16,
TRRTYPE_HTTPSSVC = nsIDNSService::RESOLVE_TYPE_HTTPSSVC, // 65
};
enum class DNSPacketStatus : uint8_t {
Unknown = 0,
Success,
KeyNotAvailable,
KeyNotUsable,
EncodeError,
EncryptError,
DecodeError,
DecryptError,
};
class DNSPacket {
public:
DNSPacket() = default;
virtual ~DNSPacket() = default;
Result<uint8_t, nsresult> GetRCode() const;
// Called in order to feed data into the buffer.
nsresult OnDataAvailable(nsIRequest* aRequest, nsIInputStream* aInputStream,
uint64_t aOffset, const uint32_t aCount);
// Encodes the name request into a buffer that represents a DNS packet
virtual nsresult EncodeRequest(nsCString& aBody, const nsACString& aHost,
uint16_t aType, bool aDisableECS);
// Decodes the DNS response and extracts the responses, additional records,
// etc. XXX: This should probably be refactored to reduce the number of
// output parameters and have a common format for different record types.
virtual nsresult Decode(
nsCString& aHost, enum TrrType aType, nsCString& aCname,
bool aAllowRFC1918, DOHresp& aResp, TypeRecordResultType& aTypeResult,
nsClassHashtable<nsCStringHashKey, DOHresp>& aAdditionalRecords,
uint32_t& aTTL);
DNSPacketStatus PacketStatus() const { return mStatus; }
protected:
// Never accept larger DOH responses than this as that would indicate
// something is wrong. Typical ones are much smaller.
static const unsigned int MAX_SIZE = 3200;
nsresult PassQName(unsigned int& index, const unsigned char* aBuffer);
nsresult GetQname(nsACString& aQname, unsigned int& aIndex,
const unsigned char* aBuffer);
nsresult ParseSvcParam(unsigned int svcbIndex, uint16_t key,
SvcFieldValue& field, uint16_t length,
const unsigned char* aBuffer);
nsresult DecodeInternal(
nsCString& aHost, enum TrrType aType, nsCString& aCname,
bool aAllowRFC1918, DOHresp& aResp, TypeRecordResultType& aTypeResult,
nsClassHashtable<nsCStringHashKey, DOHresp>& aAdditionalRecords,
uint32_t& aTTL, const unsigned char* aBuffer, uint32_t aLen);
void SetDNSPacketStatus(DNSPacketStatus aStatus) {
if (mStatus == DNSPacketStatus::Unknown ||
mStatus == DNSPacketStatus::Success) {
mStatus = aStatus;
}
}
// The response buffer.
unsigned char mResponse[MAX_SIZE]{};
unsigned int mBodySize = 0;
DNSPacketStatus mStatus = DNSPacketStatus::Unknown;
};
class ODoHDNSPacket final : public DNSPacket {
public:
ODoHDNSPacket() = default;
virtual ~ODoHDNSPacket();
static bool ParseODoHConfigs(Span<const uint8_t> aData,
nsTArray<ObliviousDoHConfig>& aOut);
virtual nsresult EncodeRequest(nsCString& aBody, const nsACString& aHost,
uint16_t aType, bool aDisableECS) override;
virtual nsresult Decode(
nsCString& aHost, enum TrrType aType, nsCString& aCname,
bool aAllowRFC1918, DOHresp& aResp, TypeRecordResultType& aTypeResult,
nsClassHashtable<nsCStringHashKey, DOHresp>& aAdditionalRecords,
uint32_t& aTTL) override;
protected:
bool EncryptDNSQuery(const nsACString& aQuery, uint16_t aPaddingLen,
const ObliviousDoHConfig& aConfig,
ObliviousDoHMessage& aOut);
bool DecryptDNSResponse();
HpkeContext* mContext = nullptr;
UniqueSECItem mPlainQuery;
// This struct indicates the range of decrypted responses stored in mResponse.
struct DecryptedResponseRange {
uint16_t mStart = 0;
uint16_t mLength = 0;
};
Maybe<DecryptedResponseRange> mDecryptedResponseRange;
};
} // namespace net
} // namespace mozilla
#endif // mozilla_net_DNSPacket_h__