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Added write protection for session to engine map. am: b6cdd12394 am: b7aa89024e

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Original change: https://googleplex-android-review.googlesource.com/c/platform/vendor/widevine/+/15180882

Change-Id: I02aa84ef497a1ac8fb6ae4b04aec85133819ccd5
This commit is contained in:
Alex Dale
2021-07-02 17:07:16 +00:00
committed by Automerger Merge Worker
parent 54c00460d3 b7aa89024e
commit 5dec140676
2 changed files with 48 additions and 17 deletions
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29
libwvdrmengine/cdm/include/wv_content_decryption_module.h
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@@ -215,6 +215,14 @@ class WvContentDecryptionModule : public android::RefBase, public TimerHandler {
void DisableTimerAndWaitForExit();
void OnTimerEvent();
// Fill the |metrics| parameter with the metrics data for the CdmEngine
// associated with the given |identifier|. If the CdmEngine instance does
// not exist, this will return an error.
// This methods assumes that |metrics| is not null and that the |cdms_lock_|
// has already been acquired.
CdmResponseType GetMetricsInternal(const CdmIdentifier& identifier,
drm_metrics::WvCdmMetrics* metrics);
static std::mutex session_sharing_id_generation_lock_;
std::mutex timer_lock_;
Timer timer_;
@@ -222,14 +230,27 @@ class WvContentDecryptionModule : public android::RefBase, public TimerHandler {
// instance variables
// This manages the lifetime of the CDM instances.
std::map<CdmIdentifier, CdmInfo> cdms_;
std::mutex cdms_lock_;
// This contains weak pointers to the CDM instances contained in |cdms_|.
std::map<std::string, CdmEngine*> cdm_by_session_id_;
// Lock for accessing either |cdms_| or |cdm_by_session_id_|.
// This lock should be acquired for any of the following:
// 1) Getting a CDM instance from |cdms_| or |cdm_by_session_id_|
// - Hold lock while searching, release lock once pointer is acquired
// 2) Iterating over |cdms_| or |cdm_by_session_id_|
// - Hold lock for the entire duration of iterating over CDMs
// - DO NOT release the lock until all operations are complete
// - This MUST be done regardless of whether |cdms_| or
// |cdm_by_session_id_| is being modified
// 3) Creating a new CDM instance with |cdms_|
// - Hold lock when creating AND initializing the CDM
// - Release once CDM is fully initialized
// 4) Linking a session to a CDM with |cdm_by_session_id_|
// - Hold lock when mapping a session ID to a CDM, release once set
// 5) Unlinking a session from a CDM with |cdm_by_session_id_|
// - Hold lock when erasing, release once erased.
std::mutex cdms_lock_;
CORE_DISALLOW_COPY_AND_ASSIGN(WvContentDecryptionModule);
};
} // namespace wvcdm
#endif // CDM_BASE_WV_CONTENT_DECRYPTION_MODULE_H_

36
libwvdrmengine/cdm/src/wv_content_decryption_module.cpp
View File

@@ -71,6 +71,7 @@ CdmResponseType WvContentDecryptionModule::OpenSession(
CdmResponseType sts = cdm_engine->OpenSession(key_system, property_set,
event_listener, session_id);
if (sts == NO_ERROR) {
std::unique_lock<std::mutex> auto_lock(cdms_lock_);
cdm_by_session_id_[*session_id] = cdm_engine;
}
return sts;
@@ -82,12 +83,11 @@ CdmResponseType WvContentDecryptionModule::CloseSession(
CdmEngine* cdm_engine = GetCdmForSessionId(session_id);
// TODO(rfrias): Avoid reusing the error codes from CdmEngine.
if (!cdm_engine) return SESSION_NOT_FOUND_1;
std::unique_lock<std::mutex> auto_lock(cdms_lock_);
CdmResponseType sts = cdm_engine->CloseSession(session_id);
const CdmResponseType sts = cdm_engine->CloseSession(session_id);
if (sts == NO_ERROR) {
std::unique_lock<std::mutex> auto_lock(cdms_lock_);
cdm_by_session_id_.erase(session_id);
}
return sts;
}
@@ -107,6 +107,7 @@ CdmResponseType WvContentDecryptionModule::GenerateKeyRequest(
if (license_type == kLicenseTypeRelease) {
sts = cdm_engine->OpenKeySetSession(key_set_id, property_set, nullptr);
if (sts != NO_ERROR) return sts;
std::unique_lock<std::mutex> auto_lock(cdms_lock_);
cdm_by_session_id_[key_set_id] = cdm_engine;
}
@@ -130,6 +131,7 @@ CdmResponseType WvContentDecryptionModule::GenerateKeyRequest(
app_parameters, key_request);
if (license_type == kLicenseTypeRelease && sts != KEY_MESSAGE) {
cdm_engine->CloseKeySetSession(key_set_id);
std::unique_lock<std::mutex> auto_lock(cdms_lock_);
cdm_by_session_id_.erase(key_set_id);
}
return sts;
@@ -152,6 +154,7 @@ CdmResponseType WvContentDecryptionModule::AddKey(
// Empty session id indicates license type release.
if (sts == KEY_ADDED && session_id.empty()) {
cdm_engine->CloseKeySetSession(release_key_set_id);
std::unique_lock<std::mutex> auto_lock(cdms_lock_);
cdm_by_session_id_.erase(release_key_set_id);
}
return sts;
@@ -297,11 +300,11 @@ CdmResponseType WvContentDecryptionModule::GetSecureStopIds(
}
CdmEngine* cdm_engine = EnsureCdmForIdentifier(identifier);
CdmResponseType sts =
const CdmResponseType sts =
cdm_engine->ListUsageIds(app_id, kSecurityLevelL1, nullptr, ssids);
std::vector<CdmSecureStopId> secure_stop_ids;
CdmResponseType sts_l3 = cdm_engine->ListUsageIds(app_id, kSecurityLevelL3,
nullptr, &secure_stop_ids);
const CdmResponseType sts_l3 = cdm_engine->ListUsageIds(
app_id, kSecurityLevelL3, nullptr, &secure_stop_ids);
ssids->insert(ssids->end(), secure_stop_ids.begin(), secure_stop_ids.end());
return sts_l3 != NO_ERROR ? sts_l3 : sts;
}
@@ -383,17 +386,19 @@ CdmResponseType WvContentDecryptionModule::GetMetrics(
if (!metrics || !full_list_returned) {
return PARAMETER_NULL;
}
std::unique_lock<std::mutex> auto_lock(cdms_lock_);
for (auto& key_value_pair : cdms_) {
const CdmIdentifier& identifier = key_value_pair.first;
drm_metrics::WvCdmMetrics metric;
CdmResponseType status = GetMetrics(key_value_pair.first, &metric);
const CdmResponseType status = GetMetricsInternal(identifier, &metric);
if (status == NO_ERROR) {
metrics->push_back(metric);
} else {
LOGD("GetMetrics call failed: cdm identifier=%u, error=%d",
key_value_pair.first.unique_id, status);
identifier.unique_id, status);
}
}
// With no streaming activities, cdms_ size would be zero,
// With no streaming activities, |cdms_| size would be zero,
// treat it as a non full list in that case.
*full_list_returned = !cdms_.empty() && metrics->size() == cdms_.size();
@@ -410,6 +415,12 @@ CdmResponseType WvContentDecryptionModule::GetMetrics(
return PARAMETER_NULL;
}
std::unique_lock<std::mutex> auto_lock(cdms_lock_);
return GetMetricsInternal(identifier, metrics);
}
CdmResponseType WvContentDecryptionModule::GetMetricsInternal(
const CdmIdentifier& identifier, drm_metrics::WvCdmMetrics* metrics) {
// Note: Caller should lock before calling.
auto it = cdms_.find(identifier);
if (it == cdms_.end()) {
LOGE("Cdm Identifier not found");
@@ -454,6 +465,7 @@ CdmEngine* WvContentDecryptionModule::EnsureCdmForIdentifier(
CdmEngine* WvContentDecryptionModule::GetCdmForSessionId(
const std::string& session_id) {
std::unique_lock<std::mutex> auto_lock(cdms_lock_);
// Use find to avoid creating empty entries when not found.
auto it = cdm_by_session_id_.find(session_id);
if (it == cdm_by_session_id_.end()) return nullptr;
@@ -462,10 +474,8 @@ CdmEngine* WvContentDecryptionModule::GetCdmForSessionId(
void WvContentDecryptionModule::CloseAllCdms() {
std::unique_lock<std::mutex> auto_lock(cdms_lock_);
for (auto it = cdms_.begin(); it != cdms_.end();) {
it = cdms_.erase(it);
}
cdm_by_session_id_.clear();
cdms_.clear();
}
CdmResponseType WvContentDecryptionModule::CloseCdm(