Merge "MediaTranscodingService: Implement service's add/remove client APIs."

1 files changed, 122 insertions, 11 deletions

diff --git a/services/mediatranscoding/MediaTranscodingService.cpp b/services/mediatranscoding/MediaTranscodingService.cpp
index 0269896c14..480844e508 100644
--- a/services/mediatranscoding/MediaTranscodingService.cpp
+++ b/services/mediatranscoding/MediaTranscodingService.cpp
@@ -16,26 +16,55 @@
 
 //#define LOG_NDEBUG 0
 #define LOG_TAG "MediaTranscodingService"
-#include "MediaTranscodingService.h"
-
+#include <MediaTranscodingService.h>
 #include <android/binder_manager.h>
 #include <android/binder_process.h>
+#include <private/android_filesystem_config.h>
 #include <utils/Log.h>
 #include <utils/Vector.h>
 
 namespace android {
 
+// Convenience methods for constructing binder::Status objects for error returns
+#define STATUS_ERROR_FMT(errorCode, errorString, ...) \
+    Status::fromServiceSpecificErrorWithMessage(      \
+            errorCode,                                \
+            String8::format("%s:%d: " errorString, __FUNCTION__, __LINE__, ##__VA_ARGS__))
+
+// Can MediaTranscoding service trust the caller based on the calling UID?
+// TODO(hkuang): Add MediaProvider's UID.
+static bool isTrustedCallingUid(uid_t uid) {
+    switch (uid) {
+    case AID_ROOT:  // root user
+    case AID_SYSTEM:
+    case AID_SHELL:
+    case AID_MEDIA:  // mediaserver
+        return true;
+    default:
+        return false;
+    }
+}
+
 MediaTranscodingService::MediaTranscodingService() {
     ALOGV("MediaTranscodingService is created");
+    mTranscodingClientManager = TranscodingClientManager::getInstance();
 }
 
 MediaTranscodingService::~MediaTranscodingService() {
     ALOGE("Should not be in ~MediaTranscodingService");
 }
 
-binder_status_t MediaTranscodingService::dump(int /* fd */, const char** /*args*/,
-                                              uint32_t /*numArgs*/) {
-    // TODO(hkuang): Add implementation.
+binder_status_t MediaTranscodingService::dump(int fd, const char** /*args*/, uint32_t /*numArgs*/) {
+    String8 result;
+    const size_t SIZE = 256;
+    char buffer[SIZE];
+
+    snprintf(buffer, SIZE, "MediaTranscodingService: %p\n", this);
+    result.append(buffer);
+    write(fd, result.string(), result.size());
+
+    Vector<String16> args;
+    mTranscodingClientManager->dumpAllClients(fd, args);
     return OK;
 }
 
@@ -51,15 +80,97 @@ void MediaTranscodingService::instantiate() {
 }
 
 Status MediaTranscodingService::registerClient(
-        const std::shared_ptr<ITranscodingServiceClient>& /*in_client*/,
-        const std::string& /* in_opPackageName */, int32_t /* in_clientUid */,
-        int32_t /* in_clientPid */, int32_t* /*_aidl_return*/) {
-    // TODO(hkuang): Add implementation.
+        const std::shared_ptr<ITranscodingServiceClient>& in_client,
+        const std::string& in_opPackageName, int32_t in_clientUid, int32_t in_clientPid,
+        int32_t* _aidl_return) {
+    if (in_client == nullptr) {
+        ALOGE("Client can not be null");
+        *_aidl_return = kInvalidJobId;
+        return Status::fromServiceSpecificError(ERROR_ILLEGAL_ARGUMENT);
+    }
+
+    int32_t callingPid = AIBinder_getCallingPid();
+    int32_t callingUid = AIBinder_getCallingUid();
+
+    // Check if we can trust clientUid. Only privilege caller could forward the uid on app client's behalf.
+    if (in_clientUid == USE_CALLING_UID) {
+        in_clientUid = callingUid;
+    } else if (!isTrustedCallingUid(callingUid)) {
+        ALOGE("MediaTranscodingService::registerClient failed (calling PID %d, calling UID %d) "
+              "rejected "
+              "(don't trust clientUid %d)",
+              in_clientPid, in_clientUid, in_clientUid);
+        return STATUS_ERROR_FMT(ERROR_PERMISSION_DENIED,
+                                "Untrusted caller (calling PID %d, UID %d) trying to "
+                                "register client",
+                                in_clientPid, in_clientUid);
+    }
+
+    // Check if we can trust clientPid. Only privilege caller could forward the pid on app client's behalf.
+    if (in_clientPid == USE_CALLING_PID) {
+        in_clientPid = callingPid;
+    } else if (!isTrustedCallingUid(callingUid)) {
+        ALOGE("MediaTranscodingService::registerClient client failed (calling PID %d, calling UID "
+              "%d) rejected "
+              "(don't trust clientPid %d)",
+              in_clientPid, in_clientUid, in_clientPid);
+        return STATUS_ERROR_FMT(ERROR_PERMISSION_DENIED,
+                                "Untrusted caller (calling PID %d, UID %d) trying to "
+                                "register client",
+                                in_clientPid, in_clientUid);
+    }
+
+    // We know the clientId must be equal to its pid as we assigned client's pid as its clientId.
+    int32_t clientId = in_clientPid;
+
+    // Checks if the client already registers.
+    if (mTranscodingClientManager->isClientIdRegistered(clientId)) {
+        return Status::fromServiceSpecificError(ERROR_ALREADY_EXISTS);
+    }
+
+    // Creates the client and uses its process id as client id.
+    std::unique_ptr<TranscodingClientManager::ClientInfo> newClient =
+            std::make_unique<TranscodingClientManager::ClientInfo>(
+                    in_client, clientId, in_clientPid, in_clientUid, in_opPackageName);
+    status_t err = mTranscodingClientManager->addClient(std::move(newClient));
+    if (err != OK) {
+        *_aidl_return = kInvalidClientId;
+        return STATUS_ERROR_FMT(err, "Failed to add client to TranscodingClientManager");
+    }
+
+    ALOGD("Assign client: %s pid: %d, uid: %d with id: %d", in_opPackageName.c_str(), in_clientPid,
+          in_clientUid, clientId);
+
+    *_aidl_return = clientId;
     return Status::ok();
 }
 
-Status MediaTranscodingService::unregisterClient(int32_t /*clientId*/, bool* /*_aidl_return*/) {
-    // TODO(hkuang): Add implementation.
+Status MediaTranscodingService::unregisterClient(int32_t clientId, bool* _aidl_return) {
+    ALOGD("unregisterClient id: %d", clientId);
+    int32_t callingUid = AIBinder_getCallingUid();
+    int32_t callingPid = AIBinder_getCallingPid();
+
+    // Only the client with clientId or the trusted caller could unregister the client.
+    if (callingPid != clientId) {
+        if (!isTrustedCallingUid(callingUid)) {
+            ALOGE("Untrusted caller (calling PID %d, UID %d) trying to "
+                  "unregister client with id: %d",
+                  callingUid, callingPid, clientId);
+            *_aidl_return = true;
+            return STATUS_ERROR_FMT(ERROR_PERMISSION_DENIED,
+                                    "Untrusted caller (calling PID %d, UID %d) trying to "
+                                    "unregister client with id: %d",
+                                    callingUid, callingPid, clientId);
+        }
+    }
+
+    *_aidl_return = (mTranscodingClientManager->removeClient(clientId) == OK);
+    return Status::ok();
+}
+
+Status MediaTranscodingService::getNumOfClients(int32_t* _aidl_return) {
+    ALOGD("MediaTranscodingService::getNumOfClients");
+    *_aidl_return = mTranscodingClientManager->getNumOfClients();
     return Status::ok();
 }