| /* |
| * Copyright (C) 2020 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. |
| */ |
| |
| #define LOG_TAG "RpcState" |
| |
| #include "RpcState.h" |
| |
| #include <android-base/hex.h> |
| #include <android-base/scopeguard.h> |
| #include <binder/BpBinder.h> |
| #include <binder/IPCThreadState.h> |
| #include <binder/RpcServer.h> |
| |
| #include "Debug.h" |
| #include "RpcWireFormat.h" |
| |
| #include <random> |
| |
| #include <inttypes.h> |
| |
| namespace android { |
| |
| using base::ScopeGuard; |
| |
| #if RPC_FLAKE_PRONE |
| void rpcMaybeWaitToFlake() { |
| [[clang::no_destroy]] static std::random_device r; |
| [[clang::no_destroy]] static std::mutex m; |
| unsigned num; |
| { |
| std::lock_guard<std::mutex> lock(m); |
| num = r(); |
| } |
| if (num % 10 == 0) usleep(num % 1000); |
| } |
| #endif |
| |
| RpcState::RpcState() {} |
| RpcState::~RpcState() {} |
| |
| status_t RpcState::onBinderLeaving(const sp<RpcSession>& session, const sp<IBinder>& binder, |
| RpcAddress* outAddress) { |
| bool isRemote = binder->remoteBinder(); |
| bool isRpc = isRemote && binder->remoteBinder()->isRpcBinder(); |
| |
| if (isRpc && binder->remoteBinder()->getPrivateAccessorForId().rpcSession() != session) { |
| // We need to be able to send instructions over the socket for how to |
| // connect to a different server, and we also need to let the host |
| // process know that this is happening. |
| ALOGE("Cannot send binder from unrelated binder RPC session."); |
| return INVALID_OPERATION; |
| } |
| |
| if (isRemote && !isRpc) { |
| // Without additional work, this would have the effect of using this |
| // process to proxy calls from the socket over to the other process, and |
| // it would make those calls look like they come from us (not over the |
| // sockets). In order to make this work transparently like binder, we |
| // would instead need to send instructions over the socket for how to |
| // connect to the host process, and we also need to let the host process |
| // know this was happening. |
| ALOGE("Cannot send binder proxy %p over sockets", binder.get()); |
| return INVALID_OPERATION; |
| } |
| |
| std::lock_guard<std::mutex> _l(mNodeMutex); |
| if (mTerminated) return DEAD_OBJECT; |
| |
| // TODO(b/182939933): maybe move address out of BpBinder, and keep binder->address map |
| // in RpcState |
| for (auto& [addr, node] : mNodeForAddress) { |
| if (binder == node.binder) { |
| if (isRpc) { |
| const RpcAddress& actualAddr = |
| binder->remoteBinder()->getPrivateAccessorForId().rpcAddress(); |
| // TODO(b/182939933): this is only checking integrity of data structure |
| // a different data structure doesn't need this |
| LOG_ALWAYS_FATAL_IF(addr < actualAddr, "Address mismatch"); |
| LOG_ALWAYS_FATAL_IF(actualAddr < addr, "Address mismatch"); |
| } |
| node.timesSent++; |
| node.sentRef = binder; // might already be set |
| *outAddress = addr; |
| return OK; |
| } |
| } |
| LOG_ALWAYS_FATAL_IF(isRpc, "RPC binder must have known address at this point"); |
| |
| bool forServer = session->server() != nullptr; |
| |
| for (size_t tries = 0; tries < 5; tries++) { |
| auto&& [it, inserted] = mNodeForAddress.insert({RpcAddress::random(forServer), |
| BinderNode{ |
| .binder = binder, |
| .timesSent = 1, |
| .sentRef = binder, |
| }}); |
| if (inserted) { |
| *outAddress = it->first; |
| return OK; |
| } |
| |
| // well, we don't have visibility into the header here, but still |
| static_assert(sizeof(RpcWireAddress) == 40, "this log needs updating"); |
| ALOGW("2**256 is 1e77. If you see this log, you probably have some entropy issue, or maybe " |
| "you witness something incredible!"); |
| } |
| |
| ALOGE("Unable to create an address in order to send out %p", binder.get()); |
| return WOULD_BLOCK; |
| } |
| |
| status_t RpcState::onBinderEntering(const sp<RpcSession>& session, const RpcAddress& address, |
| sp<IBinder>* out) { |
| // ensure that: if we want to use addresses for something else in the future (for |
| // instance, allowing transitive binder sends), that we don't accidentally |
| // send those addresses to old server. Accidentally ignoring this in that |
| // case and considering the binder to be recognized could cause this |
| // process to accidentally proxy transactions for that binder. Of course, |
| // if we communicate with a binder, it could always be proxying |
| // information. However, we want to make sure that isn't done on accident |
| // by a client. |
| if (!address.isRecognizedType()) { |
| ALOGE("Address is of an unknown type, rejecting: %s", address.toString().c_str()); |
| return BAD_VALUE; |
| } |
| |
| std::unique_lock<std::mutex> _l(mNodeMutex); |
| if (mTerminated) return DEAD_OBJECT; |
| |
| if (auto it = mNodeForAddress.find(address); it != mNodeForAddress.end()) { |
| *out = it->second.binder.promote(); |
| |
| // implicitly have strong RPC refcount, since we received this binder |
| it->second.timesRecd++; |
| |
| _l.unlock(); |
| |
| // We have timesRecd RPC refcounts, but we only need to hold on to one |
| // when we keep the object. All additional dec strongs are sent |
| // immediately, we wait to send the last one in BpBinder::onLastDecStrong. |
| (void)session->sendDecStrong(address); |
| |
| return OK; |
| } |
| |
| // we don't know about this binder, so the other side of the connection |
| // should have created it. |
| if (address.isForServer() == !!session->server()) { |
| ALOGE("Server received unrecognized address which we should own the creation of %s.", |
| address.toString().c_str()); |
| return BAD_VALUE; |
| } |
| |
| auto&& [it, inserted] = mNodeForAddress.insert({address, BinderNode{}}); |
| LOG_ALWAYS_FATAL_IF(!inserted, "Failed to insert binder when creating proxy"); |
| |
| // Currently, all binders are assumed to be part of the same session (no |
| // device global binders in the RPC world). |
| it->second.binder = *out = BpBinder::create(session, it->first); |
| it->second.timesRecd = 1; |
| return OK; |
| } |
| |
| size_t RpcState::countBinders() { |
| std::lock_guard<std::mutex> _l(mNodeMutex); |
| return mNodeForAddress.size(); |
| } |
| |
| void RpcState::dump() { |
| std::lock_guard<std::mutex> _l(mNodeMutex); |
| dumpLocked(); |
| } |
| |
| void RpcState::clear() { |
| std::unique_lock<std::mutex> _l(mNodeMutex); |
| |
| if (mTerminated) { |
| LOG_ALWAYS_FATAL_IF(!mNodeForAddress.empty(), |
| "New state should be impossible after terminating!"); |
| return; |
| } |
| |
| if (SHOULD_LOG_RPC_DETAIL) { |
| ALOGE("RpcState::clear()"); |
| dumpLocked(); |
| } |
| |
| // if the destructor of a binder object makes another RPC call, then calling |
| // decStrong could deadlock. So, we must hold onto these binders until |
| // mNodeMutex is no longer taken. |
| std::vector<sp<IBinder>> tempHoldBinder; |
| |
| mTerminated = true; |
| for (auto& [address, node] : mNodeForAddress) { |
| sp<IBinder> binder = node.binder.promote(); |
| LOG_ALWAYS_FATAL_IF(binder == nullptr, "Binder %p expected to be owned.", binder.get()); |
| |
| if (node.sentRef != nullptr) { |
| tempHoldBinder.push_back(node.sentRef); |
| } |
| } |
| |
| mNodeForAddress.clear(); |
| |
| _l.unlock(); |
| tempHoldBinder.clear(); // explicit |
| } |
| |
| void RpcState::dumpLocked() { |
| ALOGE("DUMP OF RpcState %p", this); |
| ALOGE("DUMP OF RpcState (%zu nodes)", mNodeForAddress.size()); |
| for (const auto& [address, node] : mNodeForAddress) { |
| sp<IBinder> binder = node.binder.promote(); |
| |
| const char* desc; |
| if (binder) { |
| if (binder->remoteBinder()) { |
| if (binder->remoteBinder()->isRpcBinder()) { |
| desc = "(rpc binder proxy)"; |
| } else { |
| desc = "(binder proxy)"; |
| } |
| } else { |
| desc = "(local binder)"; |
| } |
| } else { |
| desc = "(null)"; |
| } |
| |
| ALOGE("- BINDER NODE: %p times sent:%zu times recd: %zu a:%s type:%s", |
| node.binder.unsafe_get(), node.timesSent, node.timesRecd, address.toString().c_str(), |
| desc); |
| } |
| ALOGE("END DUMP OF RpcState"); |
| } |
| |
| |
| RpcState::CommandData::CommandData(size_t size) : mSize(size) { |
| // The maximum size for regular binder is 1MB for all concurrent |
| // transactions. A very small proportion of transactions are even |
| // larger than a page, but we need to avoid allocating too much |
| // data on behalf of an arbitrary client, or we could risk being in |
| // a position where a single additional allocation could run out of |
| // memory. |
| // |
| // Note, this limit may not reflect the total amount of data allocated for a |
| // transaction (in some cases, additional fixed size amounts are added), |
| // though for rough consistency, we should avoid cases where this data type |
| // is used for multiple dynamic allocations for a single transaction. |
| constexpr size_t kMaxTransactionAllocation = 100 * 1000; |
| if (size == 0) return; |
| if (size > kMaxTransactionAllocation) { |
| ALOGW("Transaction requested too much data allocation %zu", size); |
| return; |
| } |
| mData.reset(new (std::nothrow) uint8_t[size]); |
| } |
| |
| status_t RpcState::rpcSend(const sp<RpcSession::RpcConnection>& connection, |
| const sp<RpcSession>& session, const char* what, const void* data, |
| size_t size) { |
| LOG_RPC_DETAIL("Sending %s on RpcTransport %p: %s", what, connection->rpcTransport.get(), |
| android::base::HexString(data, size).c_str()); |
| |
| if (size > std::numeric_limits<ssize_t>::max()) { |
| ALOGE("Cannot send %s at size %zu (too big)", what, size); |
| (void)session->shutdownAndWait(false); |
| return BAD_VALUE; |
| } |
| |
| if (status_t status = |
| connection->rpcTransport->interruptableWriteFully(session->mShutdownTrigger.get(), |
| data, size); |
| status != OK) { |
| LOG_RPC_DETAIL("Failed to write %s (%zu bytes) on RpcTransport %p, error: %s", what, size, |
| connection->rpcTransport.get(), statusToString(status).c_str()); |
| (void)session->shutdownAndWait(false); |
| return status; |
| } |
| |
| return OK; |
| } |
| |
| status_t RpcState::rpcRec(const sp<RpcSession::RpcConnection>& connection, |
| const sp<RpcSession>& session, const char* what, void* data, |
| size_t size) { |
| if (size > std::numeric_limits<ssize_t>::max()) { |
| ALOGE("Cannot rec %s at size %zu (too big)", what, size); |
| (void)session->shutdownAndWait(false); |
| return BAD_VALUE; |
| } |
| |
| if (status_t status = |
| connection->rpcTransport->interruptableReadFully(session->mShutdownTrigger.get(), |
| data, size); |
| status != OK) { |
| LOG_RPC_DETAIL("Failed to read %s (%zu bytes) on RpcTransport %p, error: %s", what, size, |
| connection->rpcTransport.get(), statusToString(status).c_str()); |
| return status; |
| } |
| |
| LOG_RPC_DETAIL("Received %s on RpcTransport %p: %s", what, connection->rpcTransport.get(), |
| android::base::HexString(data, size).c_str()); |
| return OK; |
| } |
| |
| status_t RpcState::readNewSessionResponse(const sp<RpcSession::RpcConnection>& connection, |
| const sp<RpcSession>& session, uint32_t* version) { |
| RpcNewSessionResponse response; |
| if (status_t status = |
| rpcRec(connection, session, "new session response", &response, sizeof(response)); |
| status != OK) { |
| return status; |
| } |
| *version = response.version; |
| return OK; |
| } |
| |
| status_t RpcState::sendConnectionInit(const sp<RpcSession::RpcConnection>& connection, |
| const sp<RpcSession>& session) { |
| RpcOutgoingConnectionInit init{ |
| .msg = RPC_CONNECTION_INIT_OKAY, |
| }; |
| return rpcSend(connection, session, "connection init", &init, sizeof(init)); |
| } |
| |
| status_t RpcState::readConnectionInit(const sp<RpcSession::RpcConnection>& connection, |
| const sp<RpcSession>& session) { |
| RpcOutgoingConnectionInit init; |
| if (status_t status = rpcRec(connection, session, "connection init", &init, sizeof(init)); |
| status != OK) |
| return status; |
| |
| static_assert(sizeof(init.msg) == sizeof(RPC_CONNECTION_INIT_OKAY)); |
| if (0 != strncmp(init.msg, RPC_CONNECTION_INIT_OKAY, sizeof(init.msg))) { |
| ALOGE("Connection init message unrecognized %.*s", static_cast<int>(sizeof(init.msg)), |
| init.msg); |
| return BAD_VALUE; |
| } |
| return OK; |
| } |
| |
| sp<IBinder> RpcState::getRootObject(const sp<RpcSession::RpcConnection>& connection, |
| const sp<RpcSession>& session) { |
| Parcel data; |
| data.markForRpc(session); |
| Parcel reply; |
| |
| status_t status = transactAddress(connection, RpcAddress::zero(), RPC_SPECIAL_TRANSACT_GET_ROOT, |
| data, session, &reply, 0); |
| if (status != OK) { |
| ALOGE("Error getting root object: %s", statusToString(status).c_str()); |
| return nullptr; |
| } |
| |
| return reply.readStrongBinder(); |
| } |
| |
| status_t RpcState::getMaxThreads(const sp<RpcSession::RpcConnection>& connection, |
| const sp<RpcSession>& session, size_t* maxThreadsOut) { |
| Parcel data; |
| data.markForRpc(session); |
| Parcel reply; |
| |
| status_t status = |
| transactAddress(connection, RpcAddress::zero(), RPC_SPECIAL_TRANSACT_GET_MAX_THREADS, |
| data, session, &reply, 0); |
| if (status != OK) { |
| ALOGE("Error getting max threads: %s", statusToString(status).c_str()); |
| return status; |
| } |
| |
| int32_t maxThreads; |
| status = reply.readInt32(&maxThreads); |
| if (status != OK) return status; |
| if (maxThreads <= 0) { |
| ALOGE("Error invalid max maxThreads: %d", maxThreads); |
| return BAD_VALUE; |
| } |
| |
| *maxThreadsOut = maxThreads; |
| return OK; |
| } |
| |
| status_t RpcState::getSessionId(const sp<RpcSession::RpcConnection>& connection, |
| const sp<RpcSession>& session, RpcAddress* sessionIdOut) { |
| Parcel data; |
| data.markForRpc(session); |
| Parcel reply; |
| |
| status_t status = |
| transactAddress(connection, RpcAddress::zero(), RPC_SPECIAL_TRANSACT_GET_SESSION_ID, |
| data, session, &reply, 0); |
| if (status != OK) { |
| ALOGE("Error getting session ID: %s", statusToString(status).c_str()); |
| return status; |
| } |
| |
| return sessionIdOut->readFromParcel(reply); |
| } |
| |
| status_t RpcState::transact(const sp<RpcSession::RpcConnection>& connection, |
| const sp<IBinder>& binder, uint32_t code, const Parcel& data, |
| const sp<RpcSession>& session, Parcel* reply, uint32_t flags) { |
| if (!data.isForRpc()) { |
| ALOGE("Refusing to send RPC with parcel not crafted for RPC"); |
| return BAD_TYPE; |
| } |
| |
| if (data.objectsCount() != 0) { |
| ALOGE("Parcel at %p has attached objects but is being used in an RPC call", &data); |
| return BAD_TYPE; |
| } |
| |
| RpcAddress address = RpcAddress::zero(); |
| if (status_t status = onBinderLeaving(session, binder, &address); status != OK) return status; |
| |
| return transactAddress(connection, address, code, data, session, reply, flags); |
| } |
| |
| status_t RpcState::transactAddress(const sp<RpcSession::RpcConnection>& connection, |
| const RpcAddress& address, uint32_t code, const Parcel& data, |
| const sp<RpcSession>& session, Parcel* reply, uint32_t flags) { |
| LOG_ALWAYS_FATAL_IF(!data.isForRpc()); |
| LOG_ALWAYS_FATAL_IF(data.objectsCount() != 0); |
| |
| uint64_t asyncNumber = 0; |
| |
| if (!address.isZero()) { |
| std::unique_lock<std::mutex> _l(mNodeMutex); |
| if (mTerminated) return DEAD_OBJECT; // avoid fatal only, otherwise races |
| auto it = mNodeForAddress.find(address); |
| LOG_ALWAYS_FATAL_IF(it == mNodeForAddress.end(), "Sending transact on unknown address %s", |
| address.toString().c_str()); |
| |
| if (flags & IBinder::FLAG_ONEWAY) { |
| asyncNumber = it->second.asyncNumber; |
| if (!nodeProgressAsyncNumber(&it->second)) { |
| _l.unlock(); |
| (void)session->shutdownAndWait(false); |
| return DEAD_OBJECT; |
| } |
| } |
| } |
| |
| LOG_ALWAYS_FATAL_IF(std::numeric_limits<int32_t>::max() - sizeof(RpcWireHeader) - |
| sizeof(RpcWireTransaction) < |
| data.dataSize(), |
| "Too much data %zu", data.dataSize()); |
| |
| RpcWireHeader command{ |
| .command = RPC_COMMAND_TRANSACT, |
| .bodySize = static_cast<uint32_t>(sizeof(RpcWireTransaction) + data.dataSize()), |
| }; |
| RpcWireTransaction transaction{ |
| .address = address.viewRawEmbedded(), |
| .code = code, |
| .flags = flags, |
| .asyncNumber = asyncNumber, |
| }; |
| CommandData transactionData(sizeof(RpcWireHeader) + sizeof(RpcWireTransaction) + |
| data.dataSize()); |
| if (!transactionData.valid()) { |
| return NO_MEMORY; |
| } |
| |
| memcpy(transactionData.data() + 0, &command, sizeof(RpcWireHeader)); |
| memcpy(transactionData.data() + sizeof(RpcWireHeader), &transaction, |
| sizeof(RpcWireTransaction)); |
| memcpy(transactionData.data() + sizeof(RpcWireHeader) + sizeof(RpcWireTransaction), data.data(), |
| data.dataSize()); |
| |
| if (status_t status = rpcSend(connection, session, "transaction", transactionData.data(), |
| transactionData.size()); |
| status != OK) |
| // TODO(b/167966510): need to undo onBinderLeaving - we know the |
| // refcount isn't successfully transferred. |
| return status; |
| |
| if (flags & IBinder::FLAG_ONEWAY) { |
| LOG_RPC_DETAIL("Oneway command, so no longer waiting on RpcTransport %p", |
| connection->rpcTransport.get()); |
| |
| // Do not wait on result. |
| // However, too many oneway calls may cause refcounts to build up and fill up the socket, |
| // so process those. |
| return drainCommands(connection, session, CommandType::CONTROL_ONLY); |
| } |
| |
| LOG_ALWAYS_FATAL_IF(reply == nullptr, "Reply parcel must be used for synchronous transaction."); |
| |
| return waitForReply(connection, session, reply); |
| } |
| |
| static void cleanup_reply_data(Parcel* p, const uint8_t* data, size_t dataSize, |
| const binder_size_t* objects, size_t objectsCount) { |
| (void)p; |
| delete[] const_cast<uint8_t*>(data - offsetof(RpcWireReply, data)); |
| (void)dataSize; |
| LOG_ALWAYS_FATAL_IF(objects != nullptr); |
| LOG_ALWAYS_FATAL_IF(objectsCount != 0, "%zu objects remaining", objectsCount); |
| } |
| |
| status_t RpcState::waitForReply(const sp<RpcSession::RpcConnection>& connection, |
| const sp<RpcSession>& session, Parcel* reply) { |
| RpcWireHeader command; |
| while (true) { |
| if (status_t status = |
| rpcRec(connection, session, "command header", &command, sizeof(command)); |
| status != OK) |
| return status; |
| |
| if (command.command == RPC_COMMAND_REPLY) break; |
| |
| if (status_t status = processCommand(connection, session, command, CommandType::ANY); |
| status != OK) |
| return status; |
| } |
| |
| CommandData data(command.bodySize); |
| if (!data.valid()) return NO_MEMORY; |
| |
| if (status_t status = rpcRec(connection, session, "reply body", data.data(), command.bodySize); |
| status != OK) |
| return status; |
| |
| if (command.bodySize < sizeof(RpcWireReply)) { |
| ALOGE("Expecting %zu but got %" PRId32 " bytes for RpcWireReply. Terminating!", |
| sizeof(RpcWireReply), command.bodySize); |
| (void)session->shutdownAndWait(false); |
| return BAD_VALUE; |
| } |
| RpcWireReply* rpcReply = reinterpret_cast<RpcWireReply*>(data.data()); |
| if (rpcReply->status != OK) return rpcReply->status; |
| |
| data.release(); |
| reply->ipcSetDataReference(rpcReply->data, command.bodySize - offsetof(RpcWireReply, data), |
| nullptr, 0, cleanup_reply_data); |
| |
| reply->markForRpc(session); |
| |
| return OK; |
| } |
| |
| status_t RpcState::sendDecStrong(const sp<RpcSession::RpcConnection>& connection, |
| const sp<RpcSession>& session, const RpcAddress& addr) { |
| { |
| std::lock_guard<std::mutex> _l(mNodeMutex); |
| if (mTerminated) return DEAD_OBJECT; // avoid fatal only, otherwise races |
| auto it = mNodeForAddress.find(addr); |
| LOG_ALWAYS_FATAL_IF(it == mNodeForAddress.end(), "Sending dec strong on unknown address %s", |
| addr.toString().c_str()); |
| LOG_ALWAYS_FATAL_IF(it->second.timesRecd <= 0, "Bad dec strong %s", |
| addr.toString().c_str()); |
| |
| it->second.timesRecd--; |
| LOG_ALWAYS_FATAL_IF(nullptr != tryEraseNode(it), |
| "Bad state. RpcState shouldn't own received binder"); |
| } |
| |
| RpcWireHeader cmd = { |
| .command = RPC_COMMAND_DEC_STRONG, |
| .bodySize = sizeof(RpcWireAddress), |
| }; |
| if (status_t status = rpcSend(connection, session, "dec ref header", &cmd, sizeof(cmd)); |
| status != OK) |
| return status; |
| if (status_t status = rpcSend(connection, session, "dec ref body", &addr.viewRawEmbedded(), |
| sizeof(RpcWireAddress)); |
| status != OK) |
| return status; |
| return OK; |
| } |
| |
| status_t RpcState::getAndExecuteCommand(const sp<RpcSession::RpcConnection>& connection, |
| const sp<RpcSession>& session, CommandType type) { |
| LOG_RPC_DETAIL("getAndExecuteCommand on RpcTransport %p", connection->rpcTransport.get()); |
| |
| RpcWireHeader command; |
| if (status_t status = rpcRec(connection, session, "command header", &command, sizeof(command)); |
| status != OK) |
| return status; |
| |
| return processCommand(connection, session, command, type); |
| } |
| |
| status_t RpcState::drainCommands(const sp<RpcSession::RpcConnection>& connection, |
| const sp<RpcSession>& session, CommandType type) { |
| uint8_t buf; |
| while (connection->rpcTransport->peek(&buf, sizeof(buf)).value_or(0) > 0) { |
| status_t status = getAndExecuteCommand(connection, session, type); |
| if (status != OK) return status; |
| } |
| return OK; |
| } |
| |
| status_t RpcState::processCommand(const sp<RpcSession::RpcConnection>& connection, |
| const sp<RpcSession>& session, const RpcWireHeader& command, |
| CommandType type) { |
| IPCThreadState* kernelBinderState = IPCThreadState::selfOrNull(); |
| IPCThreadState::SpGuard spGuard{ |
| .address = __builtin_frame_address(0), |
| .context = "processing binder RPC command", |
| }; |
| const IPCThreadState::SpGuard* origGuard; |
| if (kernelBinderState != nullptr) { |
| origGuard = kernelBinderState->pushGetCallingSpGuard(&spGuard); |
| } |
| ScopeGuard guardUnguard = [&]() { |
| if (kernelBinderState != nullptr) { |
| kernelBinderState->restoreGetCallingSpGuard(origGuard); |
| } |
| }; |
| |
| switch (command.command) { |
| case RPC_COMMAND_TRANSACT: |
| if (type != CommandType::ANY) return BAD_TYPE; |
| return processTransact(connection, session, command); |
| case RPC_COMMAND_DEC_STRONG: |
| return processDecStrong(connection, session, command); |
| } |
| |
| // We should always know the version of the opposing side, and since the |
| // RPC-binder-level wire protocol is not self synchronizing, we have no way |
| // to understand where the current command ends and the next one begins. We |
| // also can't consider it a fatal error because this would allow any client |
| // to kill us, so ending the session for misbehaving client. |
| ALOGE("Unknown RPC command %d - terminating session", command.command); |
| (void)session->shutdownAndWait(false); |
| return DEAD_OBJECT; |
| } |
| status_t RpcState::processTransact(const sp<RpcSession::RpcConnection>& connection, |
| const sp<RpcSession>& session, const RpcWireHeader& command) { |
| LOG_ALWAYS_FATAL_IF(command.command != RPC_COMMAND_TRANSACT, "command: %d", command.command); |
| |
| CommandData transactionData(command.bodySize); |
| if (!transactionData.valid()) { |
| return NO_MEMORY; |
| } |
| if (status_t status = rpcRec(connection, session, "transaction body", transactionData.data(), |
| transactionData.size()); |
| status != OK) |
| return status; |
| |
| return processTransactInternal(connection, session, std::move(transactionData)); |
| } |
| |
| static void do_nothing_to_transact_data(Parcel* p, const uint8_t* data, size_t dataSize, |
| const binder_size_t* objects, size_t objectsCount) { |
| (void)p; |
| (void)data; |
| (void)dataSize; |
| (void)objects; |
| (void)objectsCount; |
| } |
| |
| status_t RpcState::processTransactInternal(const sp<RpcSession::RpcConnection>& connection, |
| const sp<RpcSession>& session, |
| CommandData transactionData) { |
| // for 'recursive' calls to this, we have already read and processed the |
| // binder from the transaction data and taken reference counts into account, |
| // so it is cached here. |
| sp<IBinder> targetRef; |
| processTransactInternalTailCall: |
| |
| if (transactionData.size() < sizeof(RpcWireTransaction)) { |
| ALOGE("Expecting %zu but got %zu bytes for RpcWireTransaction. Terminating!", |
| sizeof(RpcWireTransaction), transactionData.size()); |
| (void)session->shutdownAndWait(false); |
| return BAD_VALUE; |
| } |
| RpcWireTransaction* transaction = reinterpret_cast<RpcWireTransaction*>(transactionData.data()); |
| |
| // TODO(b/182939933): heap allocation just for lookup in mNodeForAddress, |
| // maybe add an RpcAddress 'view' if the type remains 'heavy' |
| auto addr = RpcAddress::fromRawEmbedded(&transaction->address); |
| bool oneway = transaction->flags & IBinder::FLAG_ONEWAY; |
| |
| status_t replyStatus = OK; |
| sp<IBinder> target; |
| if (!addr.isZero()) { |
| if (!targetRef) { |
| replyStatus = onBinderEntering(session, addr, &target); |
| } else { |
| target = targetRef; |
| } |
| |
| if (replyStatus != OK) { |
| // do nothing |
| } else if (target == nullptr) { |
| // This can happen if the binder is remote in this process, and |
| // another thread has called the last decStrong on this binder. |
| // However, for local binders, it indicates a misbehaving client |
| // (any binder which is being transacted on should be holding a |
| // strong ref count), so in either case, terminating the |
| // session. |
| ALOGE("While transacting, binder has been deleted at address %s. Terminating!", |
| addr.toString().c_str()); |
| (void)session->shutdownAndWait(false); |
| replyStatus = BAD_VALUE; |
| } else if (target->localBinder() == nullptr) { |
| ALOGE("Unknown binder address or non-local binder, not address %s. Terminating!", |
| addr.toString().c_str()); |
| (void)session->shutdownAndWait(false); |
| replyStatus = BAD_VALUE; |
| } else if (oneway) { |
| std::unique_lock<std::mutex> _l(mNodeMutex); |
| auto it = mNodeForAddress.find(addr); |
| if (it->second.binder.promote() != target) { |
| ALOGE("Binder became invalid during transaction. Bad client? %s", |
| addr.toString().c_str()); |
| replyStatus = BAD_VALUE; |
| } else if (transaction->asyncNumber != it->second.asyncNumber) { |
| // we need to process some other asynchronous transaction |
| // first |
| it->second.asyncTodo.push(BinderNode::AsyncTodo{ |
| .ref = target, |
| .data = std::move(transactionData), |
| .asyncNumber = transaction->asyncNumber, |
| }); |
| |
| size_t numPending = it->second.asyncTodo.size(); |
| LOG_RPC_DETAIL("Enqueuing %" PRId64 " on %s (%zu pending)", |
| transaction->asyncNumber, addr.toString().c_str(), numPending); |
| |
| constexpr size_t kArbitraryOnewayCallTerminateLevel = 10000; |
| constexpr size_t kArbitraryOnewayCallWarnLevel = 1000; |
| constexpr size_t kArbitraryOnewayCallWarnPer = 1000; |
| |
| if (numPending >= kArbitraryOnewayCallWarnLevel) { |
| if (numPending >= kArbitraryOnewayCallTerminateLevel) { |
| ALOGE("WARNING: %zu pending oneway transactions. Terminating!", numPending); |
| _l.unlock(); |
| (void)session->shutdownAndWait(false); |
| return FAILED_TRANSACTION; |
| } |
| |
| if (numPending % kArbitraryOnewayCallWarnPer == 0) { |
| ALOGW("Warning: many oneway transactions built up on %p (%zu)", |
| target.get(), numPending); |
| } |
| } |
| return OK; |
| } |
| } |
| } |
| |
| Parcel reply; |
| reply.markForRpc(session); |
| |
| if (replyStatus == OK) { |
| Parcel data; |
| // transaction->data is owned by this function. Parcel borrows this data and |
| // only holds onto it for the duration of this function call. Parcel will be |
| // deleted before the 'transactionData' object. |
| data.ipcSetDataReference(transaction->data, |
| transactionData.size() - offsetof(RpcWireTransaction, data), |
| nullptr /*object*/, 0 /*objectCount*/, |
| do_nothing_to_transact_data); |
| data.markForRpc(session); |
| |
| if (target) { |
| bool origAllowNested = connection->allowNested; |
| connection->allowNested = !oneway; |
| |
| replyStatus = target->transact(transaction->code, data, &reply, transaction->flags); |
| |
| connection->allowNested = origAllowNested; |
| } else { |
| LOG_RPC_DETAIL("Got special transaction %u", transaction->code); |
| |
| switch (transaction->code) { |
| case RPC_SPECIAL_TRANSACT_GET_MAX_THREADS: { |
| replyStatus = reply.writeInt32(session->getMaxThreads()); |
| break; |
| } |
| case RPC_SPECIAL_TRANSACT_GET_SESSION_ID: { |
| // for client connections, this should always report the value |
| // originally returned from the server, so this is asserting |
| // that it exists |
| replyStatus = session->mId.value().writeToParcel(&reply); |
| break; |
| } |
| default: { |
| sp<RpcServer> server = session->server(); |
| if (server) { |
| switch (transaction->code) { |
| case RPC_SPECIAL_TRANSACT_GET_ROOT: { |
| replyStatus = reply.writeStrongBinder(server->getRootObject()); |
| break; |
| } |
| default: { |
| replyStatus = UNKNOWN_TRANSACTION; |
| } |
| } |
| } else { |
| ALOGE("Special command sent, but no server object attached."); |
| } |
| } |
| } |
| } |
| } |
| |
| if (oneway) { |
| if (replyStatus != OK) { |
| ALOGW("Oneway call failed with error: %d", replyStatus); |
| } |
| |
| LOG_RPC_DETAIL("Processed async transaction %" PRId64 " on %s", transaction->asyncNumber, |
| addr.toString().c_str()); |
| |
| // Check to see if there is another asynchronous transaction to process. |
| // This behavior differs from binder behavior, since in the binder |
| // driver, asynchronous transactions will be processed after existing |
| // pending binder transactions on the queue. The downside of this is |
| // that asynchronous transactions can be drowned out by synchronous |
| // transactions. However, we have no easy way to queue these |
| // transactions after the synchronous transactions we may want to read |
| // from the wire. So, in socket binder here, we have the opposite |
| // downside: asynchronous transactions may drown out synchronous |
| // transactions. |
| { |
| std::unique_lock<std::mutex> _l(mNodeMutex); |
| auto it = mNodeForAddress.find(addr); |
| // last refcount dropped after this transaction happened |
| if (it == mNodeForAddress.end()) return OK; |
| |
| if (!nodeProgressAsyncNumber(&it->second)) { |
| _l.unlock(); |
| (void)session->shutdownAndWait(false); |
| return DEAD_OBJECT; |
| } |
| |
| if (it->second.asyncTodo.size() == 0) return OK; |
| if (it->second.asyncTodo.top().asyncNumber == it->second.asyncNumber) { |
| LOG_RPC_DETAIL("Found next async transaction %" PRId64 " on %s", |
| it->second.asyncNumber, addr.toString().c_str()); |
| |
| // justification for const_cast (consider avoiding priority_queue): |
| // - AsyncTodo operator< doesn't depend on 'data' or 'ref' objects |
| // - gotta go fast |
| auto& todo = const_cast<BinderNode::AsyncTodo&>(it->second.asyncTodo.top()); |
| |
| // reset up arguments |
| transactionData = std::move(todo.data); |
| targetRef = std::move(todo.ref); |
| |
| it->second.asyncTodo.pop(); |
| goto processTransactInternalTailCall; |
| } |
| } |
| return OK; |
| } |
| |
| LOG_ALWAYS_FATAL_IF(std::numeric_limits<int32_t>::max() - sizeof(RpcWireHeader) - |
| sizeof(RpcWireReply) < |
| reply.dataSize(), |
| "Too much data for reply %zu", reply.dataSize()); |
| |
| RpcWireHeader cmdReply{ |
| .command = RPC_COMMAND_REPLY, |
| .bodySize = static_cast<uint32_t>(sizeof(RpcWireReply) + reply.dataSize()), |
| }; |
| RpcWireReply rpcReply{ |
| .status = replyStatus, |
| }; |
| |
| CommandData replyData(sizeof(RpcWireHeader) + sizeof(RpcWireReply) + reply.dataSize()); |
| if (!replyData.valid()) { |
| return NO_MEMORY; |
| } |
| memcpy(replyData.data() + 0, &cmdReply, sizeof(RpcWireHeader)); |
| memcpy(replyData.data() + sizeof(RpcWireHeader), &rpcReply, sizeof(RpcWireReply)); |
| memcpy(replyData.data() + sizeof(RpcWireHeader) + sizeof(RpcWireReply), reply.data(), |
| reply.dataSize()); |
| |
| return rpcSend(connection, session, "reply", replyData.data(), replyData.size()); |
| } |
| |
| status_t RpcState::processDecStrong(const sp<RpcSession::RpcConnection>& connection, |
| const sp<RpcSession>& session, const RpcWireHeader& command) { |
| LOG_ALWAYS_FATAL_IF(command.command != RPC_COMMAND_DEC_STRONG, "command: %d", command.command); |
| |
| CommandData commandData(command.bodySize); |
| if (!commandData.valid()) { |
| return NO_MEMORY; |
| } |
| if (status_t status = |
| rpcRec(connection, session, "dec ref body", commandData.data(), commandData.size()); |
| status != OK) |
| return status; |
| |
| if (command.bodySize < sizeof(RpcWireAddress)) { |
| ALOGE("Expecting %zu but got %" PRId32 " bytes for RpcWireAddress. Terminating!", |
| sizeof(RpcWireAddress), command.bodySize); |
| (void)session->shutdownAndWait(false); |
| return BAD_VALUE; |
| } |
| RpcWireAddress* address = reinterpret_cast<RpcWireAddress*>(commandData.data()); |
| |
| // TODO(b/182939933): heap allocation just for lookup |
| auto addr = RpcAddress::fromRawEmbedded(address); |
| std::unique_lock<std::mutex> _l(mNodeMutex); |
| auto it = mNodeForAddress.find(addr); |
| if (it == mNodeForAddress.end()) { |
| ALOGE("Unknown binder address %s for dec strong.", addr.toString().c_str()); |
| return OK; |
| } |
| |
| sp<IBinder> target = it->second.binder.promote(); |
| if (target == nullptr) { |
| ALOGE("While requesting dec strong, binder has been deleted at address %s. Terminating!", |
| addr.toString().c_str()); |
| _l.unlock(); |
| (void)session->shutdownAndWait(false); |
| return BAD_VALUE; |
| } |
| |
| if (it->second.timesSent == 0) { |
| ALOGE("No record of sending binder, but requested decStrong: %s", addr.toString().c_str()); |
| return OK; |
| } |
| |
| LOG_ALWAYS_FATAL_IF(it->second.sentRef == nullptr, "Inconsistent state, lost ref for %s", |
| addr.toString().c_str()); |
| |
| it->second.timesSent--; |
| sp<IBinder> tempHold = tryEraseNode(it); |
| _l.unlock(); |
| tempHold = nullptr; // destructor may make binder calls on this session |
| |
| return OK; |
| } |
| |
| sp<IBinder> RpcState::tryEraseNode(std::map<RpcAddress, BinderNode>::iterator& it) { |
| sp<IBinder> ref; |
| |
| if (it->second.timesSent == 0) { |
| ref = std::move(it->second.sentRef); |
| |
| if (it->second.timesRecd == 0) { |
| LOG_ALWAYS_FATAL_IF(!it->second.asyncTodo.empty(), |
| "Can't delete binder w/ pending async transactions"); |
| mNodeForAddress.erase(it); |
| } |
| } |
| |
| return ref; |
| } |
| |
| bool RpcState::nodeProgressAsyncNumber(BinderNode* node) { |
| // 2**64 =~ 10**19 =~ 1000 transactions per second for 585 million years to |
| // a single binder |
| if (node->asyncNumber >= std::numeric_limits<decltype(node->asyncNumber)>::max()) { |
| ALOGE("Out of async transaction IDs. Terminating"); |
| return false; |
| } |
| node->asyncNumber++; |
| return true; |
| } |
| |
| } // namespace android |