gecko-dev/netwerk/dns/DNSPacket.h

106 lines
3.8 KiB
C++

/* 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 "nsClassHashtable.h"
#include "nsIDNSService.h"
#include "DNS.h"
#include "DNSByTypeRecord.h"
#include <functional>
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 = 0;
};
// 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
};
class DNSPacket {
public:
// 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;
DNSPacket() = default;
virtual ~DNSPacket() = default;
Result<uint8_t, nsresult> GetRCode() const;
Result<bool, nsresult> RecursionAvailable() 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);
void SetOriginHost(const Maybe<nsCString>& aHost) { mOriginHost = aHost; }
nsresult FillBuffer(std::function<int(unsigned char response[MAX_SIZE])>&&);
static nsresult ParseHTTPS(uint16_t aRDLen, struct SVCB& aParsed,
unsigned int aIndex, const unsigned char* aBuffer,
unsigned int aBodySize,
const nsACString& aOriginHost);
void SetNativePacket(bool aNative) { mNativePacket = aNative; }
protected:
nsresult PassQName(unsigned int& index, const unsigned char* aBuffer);
static nsresult GetQname(nsACString& aQname, unsigned int& aIndex,
const unsigned char* aBuffer,
unsigned int aBodySize);
static 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);
// The response buffer.
unsigned char mResponse[MAX_SIZE]{};
unsigned int mBodySize = 0;
// True when decoding a DNS packet received from OS. Decoding will
// not panic if packet ID is not zero.
bool mNativePacket = false;
nsresult mStatus = NS_OK;
Maybe<nsCString> mOriginHost;
};
} // namespace net
} // namespace mozilla
#endif // mozilla_net_DNSPacket_h__