1 files changed, 105 insertions, 0 deletions
diff --git a/netwerk/dns/DNSPacket.h b/netwerk/dns/DNSPacket.h
new file mode 100644
index 0000000000..943bcfe246
--- /dev/null
+++ b/netwerk/dns/DNSPacket.h
@@ -0,0 +1,105 @@
+/* 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__