/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

/* vim: set sw=2 ts=8 et tw=80 : */

/* 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_TRR_h

#define mozilla_net_TRR_h

#include "nsIChannel.h"

#include "nsIHttpPushListener.h"

#include "nsIInterfaceRequestor.h"

#include "nsIStreamListener.h"

namespace mozilla { namespace net {

// the values map to RFC1035 type identifiers

enum TrrType {

  TRRTYPE_A = 1,

  TRRTYPE_NS = 2,

  TRRTYPE_CNAME = 5,

  TRRTYPE_AAAA = 28,

  TRRTYPE_TXT = 16,

};

class DOHaddr : public LinkedListElement<DOHaddr> {

public:

  NetAddr mNet;

  uint32_t mTtl;

};

class TRRService;

extern TRRService *gTRRService;

class DOHresp {

public:

  ~DOHresp() {

    DOHaddr *el;

    while ((el = mAddresses.popLast())) {

      delete el;

    }

  }

  nsresult Add(uint32_t TTL, unsigned char *dns, int index, uint16_t len,

               bool aLocalAllowed);

  LinkedList<DOHaddr> mAddresses;

};

class TRR

  : public Runnable

  , public nsITimerCallback

  , public nsIHttpPushListener

  , public nsIInterfaceRequestor

  , public nsIStreamListener

{

public:

  NS_DECL_ISUPPORTS_INHERITED

  NS_DECL_NSIHTTPPUSHLISTENER

  NS_DECL_NSIINTERFACEREQUESTOR

  NS_DECL_NSIREQUESTOBSERVER

  NS_DECL_NSISTREAMLISTENER

  NS_DECL_NSITIMERCALLBACK

  // Never accept larger DOH responses than this as that would indicate

  // something is wrong. Typical ones are much smaller.

  static const unsigned int kMaxSize = 3200;

  // Number of "steps" we follow CNAME chains

  static const unsigned int kCnameChaseMax = 64;

  // when firing off a normal A or AAAA query

  explicit TRR(AHostResolver *aResolver,

               nsHostRecord *aRec,

               enum TrrType aType)

    : mozilla::Runnable("TRR")

    , mRec(aRec)

    , mHostResolver(aResolver)

    , mType(aType)

    , mBodySize(0)

    , mFailed(false)

    , mCnameLoop(kCnameChaseMax)

    , mAllowRFC1918(false)

    , mTxtTtl(UINT32_MAX)

  {

    mHost = aRec->host;

    mPB = aRec->pb;

  }

  // when following CNAMEs

  explicit TRR(AHostResolver *aResolver,

               nsHostRecord *aRec,

               nsCString &aHost,

               enum TrrType & aType,

               unsigned int aLoopCount,

               bool aPB)

    : mozilla::Runnable("TRR")

    , mHost(aHost)

    , mRec(aRec)

    , mHostResolver(aResolver)

    , mType(aType)

    , mBodySize(0)

    , mFailed(false)

    , mPB(aPB)

    , mCnameLoop(aLoopCount)

    , mAllowRFC1918(false)

    , mTxtTtl(UINT32_MAX)

  {

  }

  // used on push

  explicit TRR(AHostResolver *aResolver, bool aPB)

    : mozilla::Runnable("TRR")

    , mHostResolver(aResolver)

    , mType(TRRTYPE_A)

    , mBodySize(0)

    , mFailed(false)

    , mPB(aPB)

    , mCnameLoop(kCnameChaseMax)

    , mAllowRFC1918(false)

    , mTxtTtl(UINT32_MAX)

  { }

  // to verify a domain

  explicit TRR(AHostResolver *aResolver,

               nsACString &aHost,

               enum TrrType aType,

               bool aPB)

    : mozilla::Runnable("TRR")

    , mHost(aHost)

    , mHostResolver(aResolver)

    , mType(aType)

    , mBodySize(0)

    , mFailed(false)

    , mPB(aPB)

    , mCnameLoop(kCnameChaseMax)

    , mAllowRFC1918(false)

    , mTxtTtl(UINT32_MAX)

  { }

  NS_IMETHOD Run() override;

  void Cancel();

  enum TrrType Type() { return mType; }

  nsCString mHost;

  RefPtr<nsHostRecord> mRec;

  RefPtr<AHostResolver> mHostResolver;

private:

  ~TRR() = default;

  nsresult SendHTTPRequest();

  nsresult DohEncode(nsCString &target, bool aDisableECS);

  nsresult PassQName(unsigned int &index);

  nsresult GetQname(nsAutoCString &aQname, unsigned int &aIndex);

  nsresult DohDecode(nsCString &aHost);

  nsresult ReturnData();

  // FailData() must be called to signal that the asynch TRR resolve is

  // completed. For failed name resolves ("no such host"), the 'error' it

  // passses on in its argument must be NS_ERROR_UNKNOWN_HOST. Other errors

  // (if host was blacklisted, there as a bad content-type received, etc)

  // other error codes must be used. This distinction is important for the

  // subsequent logic to separate the error reasons.

  nsresult FailData(nsresult error);

  nsresult DohDecodeQuery(const nsCString &query,

                          nsCString &host, enum TrrType &type);

  nsresult ReceivePush(nsIHttpChannel *pushed, nsHostRecord *pushedRec);

  nsresult On200Response();

  nsCOMPtr<nsIChannel> mChannel;

  enum TrrType mType;

  TimeStamp mStartTime;

  unsigned char mResponse[kMaxSize];

  unsigned int mBodySize;

  bool mFailed;

  bool mPB;

  DOHresp mDNS;

  nsCOMPtr<nsITimer> mTimeout;

  nsCString mCname;

  uint32_t mCnameLoop; // loop detection counter

  bool mAllowRFC1918;

  nsTArray<nsCString> mTxt;

  uint32_t mTxtTtl;

};

} // namespace net

} // namespace mozilla

#endif // include guard