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/*
* Copyright (C) 2018 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef ART_RUNTIME_HIDDEN_API_H_
#define ART_RUNTIME_HIDDEN_API_H_
#include "hidden_api_access_flags.h"
#include "reflection.h"
#include "runtime.h"
namespace art {
namespace hiddenapi {
enum Action {
kAllow,
kAllowButWarn,
kAllowButWarnAndToast,
kDeny
};
inline Action GetMemberAction(uint32_t access_flags) {
switch (HiddenApiAccessFlags::DecodeFromRuntime(access_flags)) {
case HiddenApiAccessFlags::kWhitelist:
return kAllow;
case HiddenApiAccessFlags::kLightGreylist:
return kAllowButWarn;
case HiddenApiAccessFlags::kDarkGreylist:
return kAllowButWarnAndToast;
case HiddenApiAccessFlags::kBlacklist:
return kDeny;
}
}
// Issue a warning about field access.
inline void WarnAboutMemberAccess(ArtField* field) REQUIRES_SHARED(Locks::mutator_lock_) {
std::string tmp;
LOG(WARNING) << "Accessing hidden field "
<< field->GetDeclaringClass()->GetDescriptor(&tmp) << "->"
<< field->GetName() << ":" << field->GetTypeDescriptor();
}
// Issue a warning about method access.
inline void WarnAboutMemberAccess(ArtMethod* method) REQUIRES_SHARED(Locks::mutator_lock_) {
std::string tmp;
LOG(WARNING) << "Accessing hidden method "
<< method->GetDeclaringClass()->GetDescriptor(&tmp) << "->"
<< method->GetName() << method->GetSignature().ToString();
}
// Returns true if access to `member` should be denied to the caller of the
// reflective query. The decision is based on whether the caller is in boot
// class path or not. Because different users of this function determine this
// in a different way, `fn_caller_in_boot(self)` is called and should return
// true if the caller is in boot class path.
// This function might print warnings into the log if the member is greylisted.
template<typename T>
inline bool ShouldBlockAccessToMember(T* member,
Thread* self,
std::function<bool(Thread*)> fn_caller_in_boot)
REQUIRES_SHARED(Locks::mutator_lock_) {
DCHECK(member != nullptr);
Runtime* runtime = Runtime::Current();
if (!runtime->AreHiddenApiChecksEnabled()) {
// Exit early. Nothing to enforce.
return false;
}
Action action = GetMemberAction(member->GetAccessFlags());
if (action == kAllow) {
// Nothing to do.
return false;
}
// Member is hidden. Walk the stack to find the caller.
// This can be *very* expensive. Save it for last.
if (fn_caller_in_boot(self)) {
// Caller in boot class path. Exit.
return false;
}
// Member is hidden and we are not in the boot class path. Act accordingly.
if (action == kDeny) {
return true;
} else {
DCHECK(action == kAllowButWarn || action == kAllowButWarnAndToast);
// Allow access to this member but print a warning. Depending on a runtime
// flag, we might move the member into whitelist and skip the warning the
// next time the member is used.
if (runtime->ShouldDedupeHiddenApiWarnings()) {
member->SetAccessFlags(HiddenApiAccessFlags::EncodeForRuntime(
member->GetAccessFlags(), HiddenApiAccessFlags::kWhitelist));
}
WarnAboutMemberAccess(member);
if (action == kAllowButWarnAndToast || runtime->ShouldAlwaysSetHiddenApiWarningFlag()) {
Runtime::Current()->SetPendingHiddenApiWarning(true);
}
return false;
}
}
// Returns true if access to member with `access_flags` should be denied to `caller`.
// This function should be called on statically linked uses of hidden API.
inline bool ShouldBlockAccessToMember(uint32_t access_flags, mirror::Class* caller)
REQUIRES_SHARED(Locks::mutator_lock_) {
if (!Runtime::Current()->AreHiddenApiChecksEnabled()) {
// Exit early. Nothing to enforce.
return false;
}
// Only continue if we want to deny access. Warnings are *not* printed.
if (GetMemberAction(access_flags) != kDeny) {
return false;
}
// Member is hidden. Check if the caller is in boot class path.
if (caller == nullptr) {
// The caller is unknown. We assume that this is *not* boot class path.
return true;
}
return !caller->IsBootStrapClassLoaded();
}
} // namespace hiddenapi
} // namespace art
#endif // ART_RUNTIME_HIDDEN_API_H_
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