netwerk/dns/DNSPacket.h

   1 /* This Source Code Form is subject to the terms of the Mozilla Public
   2  * License, v. 2.0. If a copy of the MPL was not distributed with this
   3  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   4
   5 #ifndef mozilla_net_DNSPacket_h__
   6 #define mozilla_net_DNSPacket_h__
   7
   8 #include "mozilla/Maybe.h"
   9 #include "mozilla/Result.h"
  10 #include "pk11pub.h"
  11 #include "ScopedNSSTypes.h"
  12 #include "nsClassHashtable.h"
  13 #include "nsIDNSService.h"
  14 #include "DNS.h"
  15 #include "DNSByTypeRecord.h"
  16
  17 namespace mozilla {
  18 namespace net {
  19
  20 class DOHresp {
  21  public:
  22   nsresult Add(uint32_t TTL, unsigned char const* dns, unsigned int index,
  23                uint16_t len, bool aLocalAllowed);
  24   nsTArray<NetAddr> mAddresses;
  25   uint32_t mTtl = 0;
  26 };
  27
  28 // the values map to RFC1035 type identifiers
  29 enum TrrType {
  30   TRRTYPE_A = 1,
  31   TRRTYPE_NS = 2,
  32   TRRTYPE_CNAME = 5,
  33   TRRTYPE_AAAA = 28,
  34   TRRTYPE_OPT = 41,
  35   TRRTYPE_TXT = 16,
  36   TRRTYPE_HTTPSSVC = nsIDNSService::RESOLVE_TYPE_HTTPSSVC,  // 65
  37 };
  38
  39 enum class DNSPacketStatus : uint8_t {
  40   Unknown = 0,
  41   Success,
  42   KeyNotAvailable,
  43   KeyNotUsable,
  44   EncodeError,
  45   EncryptError,
  46   DecodeError,
  47   DecryptError,
  48 };
  49
  50 class DNSPacket {
  51  public:
  52   DNSPacket() = default;
  53   virtual ~DNSPacket() = default;
  54
  55   Result<uint8_t, nsresult> GetRCode() const;
  56   Result<bool, nsresult> RecursionAvailable() const;
  57
  58   // Called in order to feed data into the buffer.
  59   nsresult OnDataAvailable(nsIRequest* aRequest, nsIInputStream* aInputStream,
  60                            uint64_t aOffset, const uint32_t aCount);
  61
  62   // Encodes the name request into a buffer that represents a DNS packet
  63   virtual nsresult EncodeRequest(nsCString& aBody, const nsACString& aHost,
  64                                  uint16_t aType, bool aDisableECS);
  65
  66   // Decodes the DNS response and extracts the responses, additional records,
  67   // etc. XXX: This should probably be refactored to reduce the number of
  68   // output parameters and have a common format for different record types.
  69   virtual nsresult Decode(
  70       nsCString& aHost, enum TrrType aType, nsCString& aCname,
  71       bool aAllowRFC1918, DOHresp& aResp, TypeRecordResultType& aTypeResult,
  72       nsClassHashtable<nsCStringHashKey, DOHresp>& aAdditionalRecords,
  73       uint32_t& aTTL);
  74
  75   DNSPacketStatus PacketStatus() const { return mStatus; }
  76   void SetOriginHost(const Maybe<nsCString>& aHost) { mOriginHost = aHost; }
  77
  78  protected:
  79   // Never accept larger DOH responses than this as that would indicate
  80   // something is wrong. Typical ones are much smaller.
  81   static const unsigned int MAX_SIZE = 3200;
  82
  83   nsresult PassQName(unsigned int& index, const unsigned char* aBuffer);
  84   nsresult GetQname(nsACString& aQname, unsigned int& aIndex,
  85                     const unsigned char* aBuffer);
  86   nsresult ParseSvcParam(unsigned int svcbIndex, uint16_t key,
  87                          SvcFieldValue& field, uint16_t length,
  88                          const unsigned char* aBuffer);
  89   nsresult DecodeInternal(
  90       nsCString& aHost, enum TrrType aType, nsCString& aCname,
  91       bool aAllowRFC1918, DOHresp& aResp, TypeRecordResultType& aTypeResult,
  92       nsClassHashtable<nsCStringHashKey, DOHresp>& aAdditionalRecords,
  93       uint32_t& aTTL, const unsigned char* aBuffer, uint32_t aLen);
  94
  95   void SetDNSPacketStatus(DNSPacketStatus aStatus) {
  96     if (mStatus == DNSPacketStatus::Unknown ||
  97         mStatus == DNSPacketStatus::Success) {
  98       mStatus = aStatus;
  99     }
 100   }
 101
 102   // The response buffer.
 103   unsigned char mResponse[MAX_SIZE]{};
 104   unsigned int mBodySize = 0;
 105   DNSPacketStatus mStatus = DNSPacketStatus::Unknown;
 106   Maybe<nsCString> mOriginHost;
 107 };
 108
 109 }  // namespace net
 110 }  // namespace mozilla
 111
 112 #endif  // mozilla_net_DNSPacket_h__