Revert "Revert "Binder Record/Replay implemented in BBinder""

This reverts commit c6c68e30955192e0559a73ed0800d7f5b5e88ce2.

Reason for revert: Fixed build issue

Test: atest aidl_integration_test
Bug: 245596867
Change-Id: I8eba80e46689636e530edbe9e235ab58029c4649
diff --git a/libs/binder/Android.bp b/libs/binder/Android.bp
index 5dca468..b2fd7b1 100644
--- a/libs/binder/Android.bp
+++ b/libs/binder/Android.bp
@@ -76,6 +76,7 @@
 
     srcs: [
         "Binder.cpp",
+        "BinderRecordReplay.cpp",
         "BpBinder.cpp",
         "Debug.cpp",
         "FdTrigger.cpp",
@@ -147,7 +148,10 @@
         },
 
         debuggable: {
-            cflags: ["-DBINDER_RPC_DEV_SERVERS"],
+            cflags: [
+                "-DBINDER_RPC_DEV_SERVERS",
+                "-DBINDER_ENABLE_RECORDING",
+            ],
         },
     },
 
diff --git a/libs/binder/Binder.cpp b/libs/binder/Binder.cpp
index 4029957..481d704 100644
--- a/libs/binder/Binder.cpp
+++ b/libs/binder/Binder.cpp
@@ -21,6 +21,7 @@
 
 #include <android-base/logging.h>
 #include <android-base/unique_fd.h>
+#include <binder/BinderRecordReplay.h>
 #include <binder/BpBinder.h>
 #include <binder/IInterface.h>
 #include <binder/IPCThreadState.h>
@@ -28,7 +29,9 @@
 #include <binder/IShellCallback.h>
 #include <binder/Parcel.h>
 #include <binder/RpcServer.h>
+#include <cutils/compiler.h>
 #include <private/android_filesystem_config.h>
+#include <pthread.h>
 #include <utils/misc.h>
 
 #include <inttypes.h>
@@ -60,6 +63,12 @@
 bool kEnableRpcDevServers = false;
 #endif
 
+#ifdef BINDER_ENABLE_RECORDING
+bool kEnableRecording = true;
+#else
+bool kEnableRecording = false;
+#endif
+
 // Log any reply transactions for which the data exceeds this size
 #define LOG_REPLIES_OVER_SIZE (300 * 1024)
 // ---------------------------------------------------------------------------
@@ -265,11 +274,13 @@
     Mutex mLock;
     std::set<sp<RpcServerLink>> mRpcServerLinks;
     BpBinder::ObjectManager mObjects;
+
+    android::base::unique_fd mRecordingFd;
 };
 
 // ---------------------------------------------------------------------------
 
-BBinder::BBinder() : mExtras(nullptr), mStability(0), mParceled(false) {}
+BBinder::BBinder() : mExtras(nullptr), mStability(0), mParceled(false), mRecordingOn(false) {}
 
 bool BBinder::isBinderAlive() const
 {
@@ -281,6 +292,63 @@
     return NO_ERROR;
 }
 
+status_t BBinder::startRecordingTransactions(const Parcel& data) {
+    if (!kEnableRecording) {
+        ALOGW("Binder recording disallowed because recording is not enabled");
+        return INVALID_OPERATION;
+    }
+    if (!kEnableKernelIpc) {
+        ALOGW("Binder recording disallowed because kernel binder is not enabled");
+        return INVALID_OPERATION;
+    }
+    uid_t uid = IPCThreadState::self()->getCallingUid();
+    if (uid != AID_ROOT) {
+        ALOGE("Binder recording not allowed because client %" PRIu32 " is not root", uid);
+        return PERMISSION_DENIED;
+    }
+    Extras* e = getOrCreateExtras();
+    AutoMutex lock(e->mLock);
+    if (mRecordingOn) {
+        LOG(INFO) << "Could not start Binder recording. Another is already in progress.";
+        return INVALID_OPERATION;
+    } else {
+        status_t readStatus = data.readUniqueFileDescriptor(&(e->mRecordingFd));
+        if (readStatus != OK) {
+            return readStatus;
+        }
+        mRecordingOn = true;
+        LOG(INFO) << "Started Binder recording.";
+        return NO_ERROR;
+    }
+}
+
+status_t BBinder::stopRecordingTransactions() {
+    if (!kEnableRecording) {
+        ALOGW("Binder recording disallowed because recording is not enabled");
+        return INVALID_OPERATION;
+    }
+    if (!kEnableKernelIpc) {
+        ALOGW("Binder recording disallowed because kernel binder is not enabled");
+        return INVALID_OPERATION;
+    }
+    uid_t uid = IPCThreadState::self()->getCallingUid();
+    if (uid != AID_ROOT) {
+        ALOGE("Binder recording not allowed because client %" PRIu32 " is not root", uid);
+        return PERMISSION_DENIED;
+    }
+    Extras* e = getOrCreateExtras();
+    AutoMutex lock(e->mLock);
+    if (mRecordingOn) {
+        e->mRecordingFd.reset();
+        mRecordingOn = false;
+        LOG(INFO) << "Stopped Binder recording.";
+        return NO_ERROR;
+    } else {
+        LOG(INFO) << "Could not stop Binder recording. One is not in progress.";
+        return INVALID_OPERATION;
+    }
+}
+
 const String16& BBinder::getInterfaceDescriptor() const
 {
     static StaticString16 sBBinder(u"BBinder");
@@ -303,6 +371,12 @@
         case PING_TRANSACTION:
             err = pingBinder();
             break;
+        case START_RECORDING_TRANSACTION:
+            err = startRecordingTransactions(data);
+            break;
+        case STOP_RECORDING_TRANSACTION:
+            err = stopRecordingTransactions();
+            break;
         case EXTENSION_TRANSACTION:
             CHECK(reply != nullptr);
             err = reply->writeStrongBinder(getExtension());
@@ -329,6 +403,26 @@
         }
     }
 
+    if (CC_UNLIKELY(kEnableKernelIpc && mRecordingOn && code != START_RECORDING_TRANSACTION)) {
+        Extras* e = mExtras.load(std::memory_order_acquire);
+        AutoMutex lock(e->mLock);
+        if (mRecordingOn) {
+            Parcel emptyReply;
+            auto transaction =
+                    android::binder::debug::RecordedTransaction::fromDetails(code, flags, data,
+                                                                             reply ? *reply
+                                                                                   : emptyReply,
+                                                                             err);
+            if (transaction) {
+                if (status_t err = transaction->dumpToFile(e->mRecordingFd); err != NO_ERROR) {
+                    LOG(INFO) << "Failed to dump RecordedTransaction to file with error " << err;
+                }
+            } else {
+                LOG(INFO) << "Failed to create RecordedTransaction object.";
+            }
+        }
+    }
+
     return err;
 }
 
diff --git a/libs/binder/BinderRecordReplay.cpp b/libs/binder/BinderRecordReplay.cpp
new file mode 100644
index 0000000..90c02a8
--- /dev/null
+++ b/libs/binder/BinderRecordReplay.cpp
@@ -0,0 +1,185 @@
+/*
+ * Copyright (C) 2022, 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.
+ */
+
+#include <android-base/file.h>
+#include <android-base/logging.h>
+#include <binder/BinderRecordReplay.h>
+#include <algorithm>
+
+using android::Parcel;
+using android::base::unique_fd;
+using android::binder::debug::RecordedTransaction;
+
+#define PADDING8(s) ((8 - (s) % 8) % 8)
+
+static_assert(PADDING8(0) == 0);
+static_assert(PADDING8(1) == 7);
+static_assert(PADDING8(7) == 1);
+static_assert(PADDING8(8) == 0);
+
+// Transactions are sequentially recorded to the file descriptor in the following format:
+//
+// RecordedTransaction.TransactionHeader  (32 bytes)
+// Sent Parcel data                       (getDataSize() bytes)
+// padding                                (enough bytes to align the reply Parcel data to 8 bytes)
+// Reply Parcel data                      (getReplySize() bytes)
+// padding                                (enough bytes to align the next header to 8 bytes)
+// [repeats with next transaction]
+//
+// Warning: This format is non-stable
+
+RecordedTransaction::RecordedTransaction(RecordedTransaction&& t) noexcept {
+    mHeader = {t.getCode(),      t.getFlags(),          t.getDataSize(),
+               t.getReplySize(), t.getReturnedStatus(), t.getVersion()};
+    mSent.setData(t.getDataParcel().data(), t.getDataSize());
+    mReply.setData(t.getReplyParcel().data(), t.getReplySize());
+}
+
+std::optional<RecordedTransaction> RecordedTransaction::fromDetails(uint32_t code, uint32_t flags,
+                                                                    const Parcel& dataParcel,
+                                                                    const Parcel& replyParcel,
+                                                                    status_t err) {
+    RecordedTransaction t;
+    t.mHeader = {code,
+                 flags,
+                 static_cast<uint64_t>(dataParcel.dataSize()),
+                 static_cast<uint64_t>(replyParcel.dataSize()),
+                 static_cast<int32_t>(err),
+                 dataParcel.isForRpc() ? static_cast<uint32_t>(1) : static_cast<uint32_t>(0)};
+
+    if (t.mSent.setData(dataParcel.data(), t.getDataSize()) != android::NO_ERROR) {
+        LOG(INFO) << "Failed to set sent parcel data.";
+        return std::nullopt;
+    }
+
+    if (t.mReply.setData(replyParcel.data(), t.getReplySize()) != android::NO_ERROR) {
+        LOG(INFO) << "Failed to set reply parcel data.";
+        return std::nullopt;
+    }
+
+    return std::optional<RecordedTransaction>(std::move(t));
+}
+
+std::optional<RecordedTransaction> RecordedTransaction::fromFile(const unique_fd& fd) {
+    RecordedTransaction t;
+    if (!android::base::ReadFully(fd, &t.mHeader, sizeof(mHeader))) {
+        LOG(INFO) << "Failed to read transactionHeader from fd " << fd.get();
+        return std::nullopt;
+    }
+    if (t.getVersion() != 0) {
+        LOG(INFO) << "File corrupted: transaction version is not 0.";
+        return std::nullopt;
+    }
+
+    std::vector<uint8_t> bytes;
+    bytes.resize(t.getDataSize());
+    if (!android::base::ReadFully(fd, bytes.data(), t.getDataSize())) {
+        LOG(INFO) << "Failed to read sent parcel data from fd " << fd.get();
+        return std::nullopt;
+    }
+    if (t.mSent.setData(bytes.data(), t.getDataSize()) != android::NO_ERROR) {
+        LOG(INFO) << "Failed to set sent parcel data.";
+        return std::nullopt;
+    }
+
+    uint8_t padding[7];
+    if (!android::base::ReadFully(fd, padding, PADDING8(t.getDataSize()))) {
+        LOG(INFO) << "Failed to read sent parcel padding from fd " << fd.get();
+        return std::nullopt;
+    }
+    if (std::any_of(padding, padding + 7, [](uint8_t i) { return i != 0; })) {
+        LOG(INFO) << "File corrupted: padding isn't 0.";
+        return std::nullopt;
+    }
+
+    bytes.resize(t.getReplySize());
+    if (!android::base::ReadFully(fd, bytes.data(), t.getReplySize())) {
+        LOG(INFO) << "Failed to read reply parcel data from fd " << fd.get();
+        return std::nullopt;
+    }
+    if (t.mReply.setData(bytes.data(), t.getReplySize()) != android::NO_ERROR) {
+        LOG(INFO) << "Failed to set reply parcel data.";
+        return std::nullopt;
+    }
+
+    if (!android::base::ReadFully(fd, padding, PADDING8(t.getReplySize()))) {
+        LOG(INFO) << "Failed to read parcel padding from fd " << fd.get();
+        return std::nullopt;
+    }
+    if (std::any_of(padding, padding + 7, [](uint8_t i) { return i != 0; })) {
+        LOG(INFO) << "File corrupted: padding isn't 0.";
+        return std::nullopt;
+    }
+
+    return std::optional<RecordedTransaction>(std::move(t));
+}
+
+android::status_t RecordedTransaction::dumpToFile(const unique_fd& fd) const {
+    if (!android::base::WriteFully(fd, &mHeader, sizeof(mHeader))) {
+        LOG(INFO) << "Failed to write transactionHeader to fd " << fd.get();
+        return UNKNOWN_ERROR;
+    }
+    if (!android::base::WriteFully(fd, mSent.data(), getDataSize())) {
+        LOG(INFO) << "Failed to write sent parcel data to fd " << fd.get();
+        return UNKNOWN_ERROR;
+    }
+    const uint8_t zeros[7] = {0};
+    if (!android::base::WriteFully(fd, zeros, PADDING8(getDataSize()))) {
+        LOG(INFO) << "Failed to write sent parcel padding to fd " << fd.get();
+        return UNKNOWN_ERROR;
+    }
+    if (!android::base::WriteFully(fd, mReply.data(), getReplySize())) {
+        LOG(INFO) << "Failed to write reply parcel data to fd " << fd.get();
+        return UNKNOWN_ERROR;
+    }
+    if (!android::base::WriteFully(fd, zeros, PADDING8(getReplySize()))) {
+        LOG(INFO) << "Failed to write reply parcel padding to fd " << fd.get();
+        return UNKNOWN_ERROR;
+    }
+    return NO_ERROR;
+}
+
+uint32_t RecordedTransaction::getCode() const {
+    return mHeader.code;
+}
+
+uint32_t RecordedTransaction::getFlags() const {
+    return mHeader.flags;
+}
+
+uint64_t RecordedTransaction::getDataSize() const {
+    return mHeader.dataSize;
+}
+
+uint64_t RecordedTransaction::getReplySize() const {
+    return mHeader.replySize;
+}
+
+int32_t RecordedTransaction::getReturnedStatus() const {
+    return mHeader.statusReturned;
+}
+
+uint32_t RecordedTransaction::getVersion() const {
+    return mHeader.version;
+}
+
+const Parcel& RecordedTransaction::getDataParcel() const {
+    return mSent;
+}
+
+const Parcel& RecordedTransaction::getReplyParcel() const {
+    return mReply;
+}
diff --git a/libs/binder/BpBinder.cpp b/libs/binder/BpBinder.cpp
index d9b7231..54d2445 100644
--- a/libs/binder/BpBinder.cpp
+++ b/libs/binder/BpBinder.cpp
@@ -30,6 +30,8 @@
 
 #include "BuildFlags.h"
 
+#include <android-base/file.h>
+
 //#undef ALOGV
 //#define ALOGV(...) fprintf(stderr, __VA_ARGS__)
 
@@ -299,6 +301,18 @@
     return transact(PING_TRANSACTION, data, &reply);
 }
 
+status_t BpBinder::startRecordingBinder(const android::base::unique_fd& fd) {
+    Parcel send, reply;
+    send.writeUniqueFileDescriptor(fd);
+    return transact(START_RECORDING_TRANSACTION, send, &reply);
+}
+
+status_t BpBinder::stopRecordingBinder() {
+    Parcel data, reply;
+    data.markForBinder(sp<BpBinder>::fromExisting(this));
+    return transact(STOP_RECORDING_TRANSACTION, data, &reply);
+}
+
 status_t BpBinder::dump(int fd, const Vector<String16>& args)
 {
     Parcel send;
diff --git a/libs/binder/include/binder/Binder.h b/libs/binder/include/binder/Binder.h
index 88d9ca1..08dbd13 100644
--- a/libs/binder/include/binder/Binder.h
+++ b/libs/binder/include/binder/Binder.h
@@ -105,6 +105,12 @@
     [[nodiscard]] status_t setRpcClientDebug(android::base::unique_fd clientFd,
                                              const sp<IBinder>& keepAliveBinder);
 
+    // Start recording transactions to the unique_fd in data.
+    // See BinderRecordReplay.h for more details.
+    [[nodiscard]] status_t startRecordingTransactions(const Parcel& data);
+    // Stop the current recording.
+    [[nodiscard]] status_t stopRecordingTransactions();
+
 protected:
     virtual             ~BBinder();
 
@@ -131,7 +137,7 @@
     friend ::android::internal::Stability;
     int16_t mStability;
     bool mParceled;
-    uint8_t mReserved0;
+    bool mRecordingOn;
 
 #ifdef __LP64__
     int32_t mReserved1;
diff --git a/libs/binder/include/binder/BinderRecordReplay.h b/libs/binder/include/binder/BinderRecordReplay.h
new file mode 100644
index 0000000..25ed5e5
--- /dev/null
+++ b/libs/binder/include/binder/BinderRecordReplay.h
@@ -0,0 +1,80 @@
+/*
+ * Copyright (C) 2022, 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.
+ */
+
+#pragma once
+
+#include <android-base/unique_fd.h>
+#include <binder/Parcel.h>
+#include <mutex>
+
+namespace android {
+
+namespace binder::debug {
+
+// Warning: Transactions are sequentially recorded to the file descriptor in a
+// non-stable format. A detailed description of the recording format can be found in
+// BinderRecordReplay.cpp.
+
+class RecordedTransaction {
+public:
+    // Filled with the first transaction from fd.
+    static std::optional<RecordedTransaction> fromFile(const android::base::unique_fd& fd);
+    // Filled with the arguments.
+    static std::optional<RecordedTransaction> fromDetails(uint32_t code, uint32_t flags,
+                                                          const Parcel& data, const Parcel& reply,
+                                                          status_t err);
+    RecordedTransaction(RecordedTransaction&& t) noexcept;
+
+    [[nodiscard]] status_t dumpToFile(const android::base::unique_fd& fd) const;
+
+    uint32_t getCode() const;
+    uint32_t getFlags() const;
+    uint64_t getDataSize() const;
+    uint64_t getReplySize() const;
+    int32_t getReturnedStatus() const;
+    uint32_t getVersion() const;
+    const Parcel& getDataParcel() const;
+    const Parcel& getReplyParcel() const;
+
+private:
+    RecordedTransaction() = default;
+
+#pragma clang diagnostic push
+#pragma clang diagnostic error "-Wpadded"
+    struct TransactionHeader {
+        uint32_t code = 0;
+        uint32_t flags = 0;
+        uint64_t dataSize = 0;
+        uint64_t replySize = 0;
+        int32_t statusReturned = 0;
+        uint32_t version = 0; // !0 iff Rpc
+    };
+#pragma clang diagnostic pop
+    static_assert(sizeof(TransactionHeader) == 32);
+    static_assert(sizeof(TransactionHeader) % 8 == 0);
+
+    TransactionHeader mHeader;
+    Parcel mSent;
+    Parcel mReply;
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wunused-private-field"
+    uint8_t mReserved[40];
+#pragma clang diagnostic pop
+};
+
+} // namespace binder::debug
+
+} // namespace android
diff --git a/libs/binder/include/binder/BpBinder.h b/libs/binder/include/binder/BpBinder.h
index 4172cc5..57e103d 100644
--- a/libs/binder/include/binder/BpBinder.h
+++ b/libs/binder/include/binder/BpBinder.h
@@ -16,6 +16,7 @@
 
 #pragma once
 
+#include <android-base/unique_fd.h>
 #include <binder/IBinder.h>
 #include <utils/Mutex.h>
 
@@ -89,6 +90,12 @@
 
     std::optional<int32_t> getDebugBinderHandle() const;
 
+    // Start recording transactions to the unique_fd.
+    // See BinderRecordReplay.h for more details.
+    status_t startRecordingBinder(const android::base::unique_fd& fd);
+    // Stop the current recording.
+    status_t stopRecordingBinder();
+
     class ObjectManager {
     public:
         ObjectManager();
diff --git a/libs/binder/include/binder/IBinder.h b/libs/binder/include/binder/IBinder.h
index 83aaca7..e75d548 100644
--- a/libs/binder/include/binder/IBinder.h
+++ b/libs/binder/include/binder/IBinder.h
@@ -56,6 +56,8 @@
         LAST_CALL_TRANSACTION = 0x00ffffff,
 
         PING_TRANSACTION = B_PACK_CHARS('_', 'P', 'N', 'G'),
+        START_RECORDING_TRANSACTION = B_PACK_CHARS('_', 'S', 'R', 'D'),
+        STOP_RECORDING_TRANSACTION = B_PACK_CHARS('_', 'E', 'R', 'D'),
         DUMP_TRANSACTION = B_PACK_CHARS('_', 'D', 'M', 'P'),
         SHELL_COMMAND_TRANSACTION = B_PACK_CHARS('_', 'C', 'M', 'D'),
         INTERFACE_TRANSACTION = B_PACK_CHARS('_', 'N', 'T', 'F'),