/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

/* vim: set ts=8 sts=2 et sw=2 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/. */

#include "mozilla/dom/InternalHeaders.h"

#include "mozilla/dom/FetchTypes.h"

#include "mozilla/ErrorResult.h"

#include "nsCharSeparatedTokenizer.h"

#include "nsContentUtils.h"

#include "nsIHttpHeaderVisitor.h"

#include "nsNetUtil.h"

#include "nsReadableUtils.h"

namespace mozilla {

namespace dom {

InternalHeaders::InternalHeaders(const nsTArray<Entry>&& aHeaders,

                                 HeadersGuardEnum aGuard)

  : mGuard(aGuard)

  , mList(aHeaders)

  , mListDirty(true)

{

}

InternalHeaders::InternalHeaders(const nsTArray<HeadersEntry>& aHeadersEntryList,

                                 HeadersGuardEnum aGuard)

  : mGuard(aGuard)

  , mListDirty(true)

{

  for (const HeadersEntry& headersEntry : aHeadersEntryList) {

    mList.AppendElement(Entry(headersEntry.name(), headersEntry.value()));

  }

}

void

InternalHeaders::ToIPC(nsTArray<HeadersEntry>& aIPCHeaders,

                       HeadersGuardEnum& aGuard)

{

  aGuard = mGuard;

  aIPCHeaders.Clear();

  for (Entry& entry : mList) {

    aIPCHeaders.AppendElement(HeadersEntry(entry.mName, entry.mValue));

  }

}

void

InternalHeaders::Append(const nsACString& aName, const nsACString& aValue,

                        ErrorResult& aRv)

{

  nsAutoCString lowerName;

  ToLowerCase(aName, lowerName);

  nsAutoCString trimValue;

  NS_TrimHTTPWhitespace(aValue, trimValue);

  if (IsInvalidMutableHeader(lowerName, trimValue, aRv)) {

    return;

  }

  SetListDirty();

  mList.AppendElement(Entry(lowerName, trimValue));

}

void

InternalHeaders::Delete(const nsACString& aName, ErrorResult& aRv)

{

  nsAutoCString lowerName;

  ToLowerCase(aName, lowerName);

  if (IsInvalidMutableHeader(lowerName, aRv)) {

    return;

  }

  SetListDirty();

  // remove in reverse order to minimize copying

  for (int32_t i = mList.Length() - 1; i >= 0; --i) {

    if (lowerName == mList[i].mName) {

      mList.RemoveElementAt(i);

    }

  }

}

void

InternalHeaders::Get(const nsACString& aName, nsACString& aValue, ErrorResult& aRv) const

{

  nsAutoCString lowerName;

  ToLowerCase(aName, lowerName);

  if (IsInvalidName(lowerName, aRv)) {

    return;

  }

  const char* delimiter = ", ";

  bool firstValueFound = false;

  for (uint32_t i = 0; i < mList.Length(); ++i) {

    if (lowerName == mList[i].mName) {

      if (firstValueFound) {

        aValue += delimiter;

      }

      aValue += mList[i].mValue;

      firstValueFound = true;

    }

  }

  // No value found, so return null to content

  if (!firstValueFound) {

    aValue.SetIsVoid(true);

  }

}

void

InternalHeaders::GetFirst(const nsACString& aName, nsACString& aValue, ErrorResult& aRv) const

{

  nsAutoCString lowerName;

  ToLowerCase(aName, lowerName);

  if (IsInvalidName(lowerName, aRv)) {

    return;

  }

  for (uint32_t i = 0; i < mList.Length(); ++i) {

    if (lowerName == mList[i].mName) {

      aValue = mList[i].mValue;

      return;

    }

  }

  // No value found, so return null to content

  aValue.SetIsVoid(true);

}

bool

InternalHeaders::Has(const nsACString& aName, ErrorResult& aRv) const

{

  nsAutoCString lowerName;

  ToLowerCase(aName, lowerName);

  if (IsInvalidName(lowerName, aRv)) {

    return false;

  }

  for (uint32_t i = 0; i < mList.Length(); ++i) {

    if (lowerName == mList[i].mName) {

      return true;

    }

  }

  return false;

}

void

InternalHeaders::Set(const nsACString& aName, const nsACString& aValue, ErrorResult& aRv)

{

  nsAutoCString lowerName;

  ToLowerCase(aName, lowerName);

  nsAutoCString trimValue;

  NS_TrimHTTPWhitespace(aValue, trimValue);

  if (IsInvalidMutableHeader(lowerName, trimValue, aRv)) {

    return;

  }

  SetListDirty();

  int32_t firstIndex = INT32_MAX;

  // remove in reverse order to minimize copying

  for (int32_t i = mList.Length() - 1; i >= 0; --i) {

    if (lowerName == mList[i].mName) {

      firstIndex = std::min(firstIndex, i);

      mList.RemoveElementAt(i);

    }

  }

  if (firstIndex < INT32_MAX) {

    Entry* entry = mList.InsertElementAt(firstIndex);

    entry->mName = lowerName;

    entry->mValue = trimValue;

  } else {

    mList.AppendElement(Entry(lowerName, trimValue));

  }

}

void

InternalHeaders::Clear()

{

  SetListDirty();

  mList.Clear();

}

void

InternalHeaders::SetGuard(HeadersGuardEnum aGuard, ErrorResult& aRv)

{

  // The guard is only checked during ::Set() and ::Append() in the spec.  It

  // does not require revalidating headers already set.

  mGuard = aGuard;

}

InternalHeaders::~InternalHeaders()

{

}

// static

bool

InternalHeaders::IsSimpleHeader(const nsACString& aName, const nsACString& aValue)

{

  // Note, we must allow a null content-type value here to support

  // get("content-type"), but the IsInvalidValue() check will prevent null

  // from being set or appended.

  return aName.EqualsLiteral("accept") ||

         aName.EqualsLiteral("accept-language") ||

         aName.EqualsLiteral("content-language") ||

         (aName.EqualsLiteral("content-type") &&

          nsContentUtils::IsAllowedNonCorsContentType(aValue));

}

// static

bool

InternalHeaders::IsRevalidationHeader(const nsACString& aName)

{

  return aName.EqualsLiteral("if-modified-since") ||

         aName.EqualsLiteral("if-none-match") ||

         aName.EqualsLiteral("if-unmodified-since") ||

         aName.EqualsLiteral("if-match") ||

         aName.EqualsLiteral("if-range");

}

//static

bool

InternalHeaders::IsInvalidName(const nsACString& aName, ErrorResult& aRv)

{

  if (!NS_IsValidHTTPToken(aName)) {

    NS_ConvertUTF8toUTF16 label(aName);

    aRv.ThrowTypeError<MSG_INVALID_HEADER_NAME>(label);

    return true;

  }

  return false;

}

// static

bool

InternalHeaders::IsInvalidValue(const nsACString& aValue, ErrorResult& aRv)

{

  if (!NS_IsReasonableHTTPHeaderValue(aValue)) {

    NS_ConvertUTF8toUTF16 label(aValue);

    aRv.ThrowTypeError<MSG_INVALID_HEADER_VALUE>(label);

    return true;

  }

  return false;

}

bool

InternalHeaders::IsImmutable(ErrorResult& aRv) const

{

  if (mGuard == HeadersGuardEnum::Immutable) {

    aRv.ThrowTypeError<MSG_HEADERS_IMMUTABLE>();

    return true;

  }

  return false;

}

bool

InternalHeaders::IsForbiddenRequestHeader(const nsACString& aName) const

{

  return mGuard == HeadersGuardEnum::Request &&

         nsContentUtils::IsForbiddenRequestHeader(aName);

}

bool

InternalHeaders::IsForbiddenRequestNoCorsHeader(const nsACString& aName) const

{

  return mGuard == HeadersGuardEnum::Request_no_cors &&

         !IsSimpleHeader(aName, EmptyCString());

}

bool

InternalHeaders::IsForbiddenRequestNoCorsHeader(const nsACString& aName,

                                                const nsACString& aValue) const

{

  return mGuard == HeadersGuardEnum::Request_no_cors &&

         !IsSimpleHeader(aName, aValue);

}

bool

InternalHeaders::IsForbiddenResponseHeader(const nsACString& aName) const

{

  return mGuard == HeadersGuardEnum::Response &&

         nsContentUtils::IsForbiddenResponseHeader(aName);

}

void

InternalHeaders::Fill(const InternalHeaders& aInit, ErrorResult& aRv)

{

  const nsTArray<Entry>& list = aInit.mList;

  for (uint32_t i = 0; i < list.Length() && !aRv.Failed(); ++i) {

    const Entry& entry = list[i];

    Append(entry.mName, entry.mValue, aRv);

  }

}

void

InternalHeaders::Fill(const Sequence<Sequence<nsCString>>& aInit, ErrorResult& aRv)

{

  for (uint32_t i = 0; i < aInit.Length() && !aRv.Failed(); ++i) {

    const Sequence<nsCString>& tuple = aInit[i];

    if (tuple.Length() != 2) {

      aRv.ThrowTypeError<MSG_INVALID_HEADER_SEQUENCE>();

      return;

    }

    Append(tuple[0], tuple[1], aRv);

  }

}

void

InternalHeaders::Fill(const Record<nsCString, nsCString>& aInit, ErrorResult& aRv)

{

  for (auto& entry : aInit.Entries()) {

    Append(entry.mKey, entry.mValue, aRv);

    if (aRv.Failed()) {

      return;

    }

  }

}

namespace {

class FillHeaders final : public nsIHttpHeaderVisitor

{

  RefPtr<InternalHeaders> mInternalHeaders;

  ~FillHeaders() = default;

public:

  NS_DECL_ISUPPORTS

  explicit FillHeaders(InternalHeaders* aInternalHeaders)

    : mInternalHeaders(aInternalHeaders)

  {

    MOZ_DIAGNOSTIC_ASSERT(mInternalHeaders);

  }

  NS_IMETHOD

  VisitHeader(const nsACString& aHeader, const nsACString& aValue) override

  {

    mInternalHeaders->Append(aHeader, aValue, IgnoreErrors());

    return NS_OK;

  }

};

NS_IMPL_ISUPPORTS(FillHeaders, nsIHttpHeaderVisitor)

} // namespace

void

InternalHeaders::FillResponseHeaders(nsIRequest* aRequest)

{

  nsCOMPtr<nsIHttpChannel> httpChannel = do_QueryInterface(aRequest);

  if (!httpChannel) {

    return;

  }

  RefPtr<FillHeaders> visitor = new FillHeaders(this);

  nsresult rv = httpChannel->VisitResponseHeaders(visitor);

  if (NS_FAILED(rv)) {

    NS_WARNING("failed to fill headers");

  }

}

bool

InternalHeaders::HasOnlySimpleHeaders() const

{

  for (uint32_t i = 0; i < mList.Length(); ++i) {

    if (!IsSimpleHeader(mList[i].mName, mList[i].mValue)) {

      return false;

    }

  }

  return true;

}

bool

InternalHeaders::HasRevalidationHeaders() const

{

  for (uint32_t i = 0; i < mList.Length(); ++i) {

    if (IsRevalidationHeader(mList[i].mName)) {

      return true;

    }

  }

  return false;

}

// static

already_AddRefed<InternalHeaders>

InternalHeaders::BasicHeaders(InternalHeaders* aHeaders)

{

  RefPtr<InternalHeaders> basic = new InternalHeaders(*aHeaders);

  ErrorResult result;

  // The Set-Cookie headers cannot be invalid mutable headers, so the Delete

  // must succeed.

  basic->Delete(NS_LITERAL_CSTRING("Set-Cookie"), result);

  MOZ_ASSERT(!result.Failed());

  basic->Delete(NS_LITERAL_CSTRING("Set-Cookie2"), result);

  MOZ_ASSERT(!result.Failed());

  return basic.forget();

}

// static

already_AddRefed<InternalHeaders>

InternalHeaders::CORSHeaders(InternalHeaders* aHeaders)

{

  RefPtr<InternalHeaders> cors = new InternalHeaders(aHeaders->mGuard);

  ErrorResult result;

  nsAutoCString acExposedNames;

  aHeaders->GetFirst(NS_LITERAL_CSTRING("Access-Control-Expose-Headers"), acExposedNames, result);

  MOZ_ASSERT(!result.Failed());

  AutoTArray<nsCString, 5> exposeNamesArray;

  nsCCharSeparatedTokenizer exposeTokens(acExposedNames, ',');

  while (exposeTokens.hasMoreTokens()) {

    const nsDependentCSubstring& token = exposeTokens.nextToken();

    if (token.IsEmpty()) {

      continue;

    }

    if (!NS_IsValidHTTPToken(token)) {

      NS_WARNING("Got invalid HTTP token in Access-Control-Expose-Headers. Header value is:");

      NS_WARNING(acExposedNames.get());

      exposeNamesArray.Clear();

      break;

    }

    exposeNamesArray.AppendElement(token);

  }

  nsCaseInsensitiveCStringArrayComparator comp;

  for (uint32_t i = 0; i < aHeaders->mList.Length(); ++i) {

    const Entry& entry = aHeaders->mList[i];

    if (entry.mName.EqualsASCII("cache-control") ||

        entry.mName.EqualsASCII("content-language") ||

        entry.mName.EqualsASCII("content-type") ||

        entry.mName.EqualsASCII("expires") ||

        entry.mName.EqualsASCII("last-modified") ||

        entry.mName.EqualsASCII("pragma") ||

        exposeNamesArray.Contains(entry.mName, comp)) {

      cors->Append(entry.mName, entry.mValue, result);

      MOZ_ASSERT(!result.Failed());

    }

  }

  return cors.forget();

}

void

InternalHeaders::GetEntries(nsTArray<InternalHeaders::Entry>& aEntries) const

{

  MOZ_ASSERT(aEntries.IsEmpty());

  aEntries.AppendElements(mList);

}

void

InternalHeaders::GetUnsafeHeaders(nsTArray<nsCString>& aNames) const

{

  MOZ_ASSERT(aNames.IsEmpty());

  for (uint32_t i = 0; i < mList.Length(); ++i) {

    const Entry& header = mList[i];

    if (!InternalHeaders::IsSimpleHeader(header.mName, header.mValue)) {

      aNames.AppendElement(header.mName);

    }

  }

}

void

InternalHeaders::MaybeSortList()

{

  class Comparator {

  public:

    bool Equals(const Entry& aA, const Entry& aB) const

    {

       return aA.mName == aB.mName;

    }

    bool LessThan(const Entry& aA, const Entry& aB) const

    {

      return aA.mName < aB.mName;

    }

  };

  if (!mListDirty) {

    return;

  }

  mListDirty = false;

  Comparator comparator;

  mSortedList.Clear();

  for (const Entry& entry : mList) {

    bool found = false;

    for (Entry& sortedEntry : mSortedList) {

      if (sortedEntry.mName == entry.mName) {

        sortedEntry.mValue += ", ";

        sortedEntry.mValue += entry.mValue;

        found = true;

        break;

      }

    }

    if (!found) {

      mSortedList.InsertElementSorted(entry, comparator);

    }

  }

}

void

InternalHeaders::SetListDirty()

{

  mSortedList.Clear();

  mListDirty = true;

}

} // namespace dom

} // namespace mozilla