|  | /* | 
|  | * 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/macros.h> | 
|  | #include <android-base/scopeguard.h> | 
|  | #include <android-base/stringprintf.h> | 
|  | #include <binder/BpBinder.h> | 
|  | #include <binder/IPCThreadState.h> | 
|  | #include <binder/RpcServer.h> | 
|  |  | 
|  | #include "Debug.h" | 
|  | #include "RpcWireFormat.h" | 
|  | #include "Utils.h" | 
|  |  | 
|  | #include <random> | 
|  |  | 
|  | #include <inttypes.h> | 
|  |  | 
|  | namespace android { | 
|  |  | 
|  | using base::StringPrintf; | 
|  |  | 
|  | #if RPC_FLAKE_PRONE | 
|  | void rpcMaybeWaitToFlake() { | 
|  | [[clang::no_destroy]] static std::random_device r; | 
|  | [[clang::no_destroy]] static std::mutex m; | 
|  | unsigned num; | 
|  | { | 
|  | RpcMutexLockGuard lock(m); | 
|  | num = r(); | 
|  | } | 
|  | if (num % 10 == 0) usleep(num % 1000); | 
|  | } | 
|  | #endif | 
|  |  | 
|  | static bool enableAncillaryFds(RpcSession::FileDescriptorTransportMode mode) { | 
|  | switch (mode) { | 
|  | case RpcSession::FileDescriptorTransportMode::NONE: | 
|  | return false; | 
|  | case RpcSession::FileDescriptorTransportMode::UNIX: | 
|  | return true; | 
|  | } | 
|  | } | 
|  |  | 
|  | RpcState::RpcState() {} | 
|  | RpcState::~RpcState() {} | 
|  |  | 
|  | status_t RpcState::onBinderLeaving(const sp<RpcSession>& session, const sp<IBinder>& binder, | 
|  | uint64_t* outAddress) { | 
|  | bool isRemote = binder->remoteBinder(); | 
|  | bool isRpc = isRemote && binder->remoteBinder()->isRpcBinder(); | 
|  |  | 
|  | if (isRpc && binder->remoteBinder()->getPrivateAccessor().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; | 
|  | } | 
|  |  | 
|  | RpcMutexLockGuard _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) { | 
|  | // check integrity of data structure | 
|  | uint64_t actualAddr = binder->remoteBinder()->getPrivateAccessor().rpcAddress(); | 
|  | LOG_ALWAYS_FATAL_IF(addr != actualAddr, "Address mismatch %" PRIu64 " vs %" PRIu64, | 
|  | addr, actualAddr); | 
|  | } | 
|  | 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; | 
|  |  | 
|  | // arbitrary limit for maximum number of nodes in a process (otherwise we | 
|  | // might run out of addresses) | 
|  | if (mNodeForAddress.size() > 100000) { | 
|  | return NO_MEMORY; | 
|  | } | 
|  |  | 
|  | while (true) { | 
|  | RpcWireAddress address{ | 
|  | .options = RPC_WIRE_ADDRESS_OPTION_CREATED, | 
|  | .address = mNextId, | 
|  | }; | 
|  | if (forServer) { | 
|  | address.options |= RPC_WIRE_ADDRESS_OPTION_FOR_SERVER; | 
|  | } | 
|  |  | 
|  | // avoid ubsan abort | 
|  | if (mNextId >= std::numeric_limits<uint32_t>::max()) { | 
|  | mNextId = 0; | 
|  | } else { | 
|  | mNextId++; | 
|  | } | 
|  |  | 
|  | auto&& [it, inserted] = mNodeForAddress.insert({RpcWireAddress::toRaw(address), | 
|  | BinderNode{ | 
|  | .binder = binder, | 
|  | .sentRef = binder, | 
|  | .timesSent = 1, | 
|  | }}); | 
|  | if (inserted) { | 
|  | *outAddress = it->first; | 
|  | return OK; | 
|  | } | 
|  | } | 
|  | } | 
|  |  | 
|  | status_t RpcState::onBinderEntering(const sp<RpcSession>& session, uint64_t 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. | 
|  | RpcWireAddress addr = RpcWireAddress::fromRaw(address); | 
|  | constexpr uint32_t kKnownOptions = | 
|  | RPC_WIRE_ADDRESS_OPTION_CREATED | RPC_WIRE_ADDRESS_OPTION_FOR_SERVER; | 
|  | if (addr.options & ~kKnownOptions) { | 
|  | ALOGE("Address is of an unknown type, rejecting: %" PRIu64, address); | 
|  | return BAD_VALUE; | 
|  | } | 
|  |  | 
|  | RpcMutexLockGuard _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++; | 
|  | return OK; | 
|  | } | 
|  |  | 
|  | // we don't know about this binder, so the other side of the connection | 
|  | // should have created it. | 
|  | if ((addr.options & RPC_WIRE_ADDRESS_OPTION_FOR_SERVER) == !!session->server()) { | 
|  | ALOGE("Server received unrecognized address which we should own the creation of %" PRIu64, | 
|  | address); | 
|  | 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::PrivateAccessor::create(session, it->first); | 
|  | it->second.timesRecd = 1; | 
|  | return OK; | 
|  | } | 
|  |  | 
|  | status_t RpcState::flushExcessBinderRefs(const sp<RpcSession>& session, uint64_t address, | 
|  | const sp<IBinder>& binder) { | 
|  | // We can flush all references when the binder is destroyed. No need to send | 
|  | // extra reference counting packets now. | 
|  | if (binder->remoteBinder()) return OK; | 
|  |  | 
|  | RpcMutexUniqueLock _l(mNodeMutex); | 
|  | if (mTerminated) return DEAD_OBJECT; | 
|  |  | 
|  | auto it = mNodeForAddress.find(address); | 
|  |  | 
|  | LOG_ALWAYS_FATAL_IF(it == mNodeForAddress.end(), "Can't be deleted while we hold sp<>"); | 
|  | LOG_ALWAYS_FATAL_IF(it->second.binder != binder, | 
|  | "Caller of flushExcessBinderRefs using inconsistent arguments"); | 
|  |  | 
|  | LOG_ALWAYS_FATAL_IF(it->second.timesSent <= 0, "Local binder must have been sent %p", | 
|  | binder.get()); | 
|  |  | 
|  | // For a local binder, we only need to know that we sent it. Now that we | 
|  | // have an sp<> for this call, we don't need anything more. If the other | 
|  | // process is done with this binder, it needs to know we received the | 
|  | // refcount associated with this call, so we can acknowledge that we | 
|  | // received it. Once (or if) it has no other refcounts, it would reply with | 
|  | // its own decStrong so that it could be removed from this session. | 
|  | if (it->second.timesRecd != 0) { | 
|  | _l.unlock(); | 
|  |  | 
|  | return session->sendDecStrongToTarget(address, 0); | 
|  | } | 
|  |  | 
|  | return OK; | 
|  | } | 
|  |  | 
|  | status_t RpcState::sendObituaries(const sp<RpcSession>& session) { | 
|  | RpcMutexUniqueLock _l(mNodeMutex); | 
|  |  | 
|  | // Gather strong pointers to all of the remote binders for this session so | 
|  | // we hold the strong references. remoteBinder() returns a raw pointer. | 
|  | // Send the obituaries and drop the strong pointers outside of the lock so | 
|  | // the destructors and the onBinderDied calls are not done while locked. | 
|  | std::vector<sp<IBinder>> remoteBinders; | 
|  | for (const auto& [_, binderNode] : mNodeForAddress) { | 
|  | if (auto binder = binderNode.binder.promote()) { | 
|  | remoteBinders.push_back(std::move(binder)); | 
|  | } | 
|  | } | 
|  | _l.unlock(); | 
|  |  | 
|  | for (const auto& binder : remoteBinders) { | 
|  | if (binder->remoteBinder() && | 
|  | binder->remoteBinder()->getPrivateAccessor().rpcSession() == session) { | 
|  | binder->remoteBinder()->sendObituary(); | 
|  | } | 
|  | } | 
|  | return OK; | 
|  | } | 
|  |  | 
|  | size_t RpcState::countBinders() { | 
|  | RpcMutexLockGuard _l(mNodeMutex); | 
|  | return mNodeForAddress.size(); | 
|  | } | 
|  |  | 
|  | void RpcState::dump() { | 
|  | RpcMutexLockGuard _l(mNodeMutex); | 
|  | dumpLocked(); | 
|  | } | 
|  |  | 
|  | void RpcState::clear() { | 
|  | RpcMutexUniqueLock _l(mNodeMutex); | 
|  |  | 
|  | if (mTerminated) { | 
|  | LOG_ALWAYS_FATAL_IF(!mNodeForAddress.empty(), | 
|  | "New state should be impossible after terminating!"); | 
|  | return; | 
|  | } | 
|  | mTerminated = true; | 
|  |  | 
|  | if (SHOULD_LOG_RPC_DETAIL) { | 
|  | ALOGE("RpcState::clear()"); | 
|  | dumpLocked(); | 
|  | } | 
|  |  | 
|  | // invariants | 
|  | for (auto& [address, node] : mNodeForAddress) { | 
|  | bool guaranteedHaveBinder = node.timesSent > 0; | 
|  | if (guaranteedHaveBinder) { | 
|  | LOG_ALWAYS_FATAL_IF(node.sentRef == nullptr, | 
|  | "Binder expected to be owned with address: %" PRIu64 " %s", address, | 
|  | node.toString().c_str()); | 
|  | } | 
|  | } | 
|  |  | 
|  | // 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. | 
|  | auto temp = std::move(mNodeForAddress); | 
|  | mNodeForAddress.clear(); // RpcState isn't reusable, but for future/explicit | 
|  |  | 
|  | _l.unlock(); | 
|  | temp.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) { | 
|  | ALOGE("- address: %" PRIu64 " %s", address, node.toString().c_str()); | 
|  | } | 
|  | ALOGE("END DUMP OF RpcState"); | 
|  | } | 
|  |  | 
|  | std::string RpcState::BinderNode::toString() const { | 
|  | sp<IBinder> strongBinder = this->binder.promote(); | 
|  |  | 
|  | const char* desc; | 
|  | if (strongBinder) { | 
|  | if (strongBinder->remoteBinder()) { | 
|  | if (strongBinder->remoteBinder()->isRpcBinder()) { | 
|  | desc = "(rpc binder proxy)"; | 
|  | } else { | 
|  | desc = "(binder proxy)"; | 
|  | } | 
|  | } else { | 
|  | desc = "(local binder)"; | 
|  | } | 
|  | } else { | 
|  | desc = "(not promotable)"; | 
|  | } | 
|  |  | 
|  | return StringPrintf("node{%p times sent: %zu times recd: %zu type: %s}", | 
|  | this->binder.unsafe_get(), this->timesSent, this->timesRecd, desc); | 
|  | } | 
|  |  | 
|  | 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, iovec* iovs, int niovs, | 
|  | const std::optional<android::base::function_ref<status_t()>>& altPoll, | 
|  | const std::vector<std::variant<base::unique_fd, base::borrowed_fd>>* ancillaryFds) { | 
|  | for (int i = 0; i < niovs; i++) { | 
|  | LOG_RPC_DETAIL("Sending %s (part %d of %d) on RpcTransport %p: %s", | 
|  | what, i + 1, niovs, connection->rpcTransport.get(), | 
|  | android::base::HexString(iovs[i].iov_base, iovs[i].iov_len).c_str()); | 
|  | } | 
|  |  | 
|  | if (status_t status = | 
|  | connection->rpcTransport->interruptableWriteFully(session->mShutdownTrigger.get(), | 
|  | iovs, niovs, altPoll, | 
|  | ancillaryFds); | 
|  | status != OK) { | 
|  | LOG_RPC_DETAIL("Failed to write %s (%d iovs) on RpcTransport %p, error: %s", what, niovs, | 
|  | 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, iovec* iovs, int niovs, | 
|  | std::vector<std::variant<base::unique_fd, base::borrowed_fd>>* ancillaryFds) { | 
|  | if (status_t status = | 
|  | connection->rpcTransport->interruptableReadFully(session->mShutdownTrigger.get(), | 
|  | iovs, niovs, std::nullopt, | 
|  | ancillaryFds); | 
|  | status != OK) { | 
|  | LOG_RPC_DETAIL("Failed to read %s (%d iovs) on RpcTransport %p, error: %s", what, niovs, | 
|  | connection->rpcTransport.get(), statusToString(status).c_str()); | 
|  | (void)session->shutdownAndWait(false); | 
|  | return status; | 
|  | } | 
|  |  | 
|  | for (int i = 0; i < niovs; i++) { | 
|  | LOG_RPC_DETAIL("Received %s (part %d of %d) on RpcTransport %p: %s", | 
|  | what, i + 1, niovs, connection->rpcTransport.get(), | 
|  | android::base::HexString(iovs[i].iov_base, iovs[i].iov_len).c_str()); | 
|  | } | 
|  | return OK; | 
|  | } | 
|  |  | 
|  | status_t RpcState::readNewSessionResponse(const sp<RpcSession::RpcConnection>& connection, | 
|  | const sp<RpcSession>& session, uint32_t* version) { | 
|  | RpcNewSessionResponse response; | 
|  | iovec iov{&response, sizeof(response)}; | 
|  | if (status_t status = rpcRec(connection, session, "new session response", &iov, 1, nullptr); | 
|  | 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, | 
|  | }; | 
|  | iovec iov{&init, sizeof(init)}; | 
|  | return rpcSend(connection, session, "connection init", &iov, 1, std::nullopt); | 
|  | } | 
|  |  | 
|  | status_t RpcState::readConnectionInit(const sp<RpcSession::RpcConnection>& connection, | 
|  | const sp<RpcSession>& session) { | 
|  | RpcOutgoingConnectionInit init; | 
|  | iovec iov{&init, sizeof(init)}; | 
|  | if (status_t status = rpcRec(connection, session, "connection init", &iov, 1, nullptr); | 
|  | 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, 0, 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, 0, 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, std::vector<uint8_t>* sessionIdOut) { | 
|  | Parcel data; | 
|  | data.markForRpc(session); | 
|  | Parcel reply; | 
|  |  | 
|  | status_t status = transactAddress(connection, 0, 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 reply.readByteVector(sessionIdOut); | 
|  | } | 
|  |  | 
|  | 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) { | 
|  | std::string errorMsg; | 
|  | if (status_t status = validateParcel(session, data, &errorMsg); status != OK) { | 
|  | ALOGE("Refusing to send RPC on binder %p code %" PRIu32 ": Parcel %p failed validation: %s", | 
|  | binder.get(), code, &data, errorMsg.c_str()); | 
|  | return status; | 
|  | } | 
|  | uint64_t address; | 
|  | 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, | 
|  | uint64_t 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 != 0) { | 
|  | RpcMutexUniqueLock _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 %" PRIu64, address); | 
|  |  | 
|  | if (flags & IBinder::FLAG_ONEWAY) { | 
|  | asyncNumber = it->second.asyncNumber; | 
|  | if (!nodeProgressAsyncNumber(&it->second)) { | 
|  | _l.unlock(); | 
|  | (void)session->shutdownAndWait(false); | 
|  | return DEAD_OBJECT; | 
|  | } | 
|  | } | 
|  | } | 
|  |  | 
|  | auto* rpcFields = data.maybeRpcFields(); | 
|  | LOG_ALWAYS_FATAL_IF(rpcFields == nullptr); | 
|  |  | 
|  | Span<const uint32_t> objectTableSpan = Span<const uint32_t>{rpcFields->mObjectPositions.data(), | 
|  | rpcFields->mObjectPositions.size()}; | 
|  |  | 
|  | uint32_t bodySize; | 
|  | LOG_ALWAYS_FATAL_IF(__builtin_add_overflow(sizeof(RpcWireTransaction), data.dataSize(), | 
|  | &bodySize) || | 
|  | __builtin_add_overflow(objectTableSpan.byteSize(), bodySize, | 
|  | &bodySize), | 
|  | "Too much data %zu", data.dataSize()); | 
|  | RpcWireHeader command{ | 
|  | .command = RPC_COMMAND_TRANSACT, | 
|  | .bodySize = bodySize, | 
|  | }; | 
|  |  | 
|  | RpcWireTransaction transaction{ | 
|  | .address = RpcWireAddress::fromRaw(address), | 
|  | .code = code, | 
|  | .flags = flags, | 
|  | .asyncNumber = asyncNumber, | 
|  | // bodySize didn't overflow => this cast is safe | 
|  | .parcelDataSize = static_cast<uint32_t>(data.dataSize()), | 
|  | }; | 
|  |  | 
|  | constexpr size_t kWaitMaxUs = 1000000; | 
|  | constexpr size_t kWaitLogUs = 10000; | 
|  | size_t waitUs = 0; | 
|  |  | 
|  | // Oneway calls have no sync point, so if many are sent before, whether this | 
|  | // is a twoway or oneway transaction, they may have filled up the socket. | 
|  | // So, make sure we drain them before polling | 
|  |  | 
|  | iovec iovs[]{ | 
|  | {&command, sizeof(RpcWireHeader)}, | 
|  | {&transaction, sizeof(RpcWireTransaction)}, | 
|  | {const_cast<uint8_t*>(data.data()), data.dataSize()}, | 
|  | objectTableSpan.toIovec(), | 
|  | }; | 
|  | if (status_t status = rpcSend( | 
|  | connection, session, "transaction", iovs, arraysize(iovs), | 
|  | [&] { | 
|  | if (waitUs > kWaitLogUs) { | 
|  | ALOGE("Cannot send command, trying to process pending refcounts. Waiting " | 
|  | "%zuus. Too many oneway calls?", | 
|  | waitUs); | 
|  | } | 
|  |  | 
|  | if (waitUs > 0) { | 
|  | usleep(waitUs); | 
|  | waitUs = std::min(kWaitMaxUs, waitUs * 2); | 
|  | } else { | 
|  | waitUs = 1; | 
|  | } | 
|  |  | 
|  | return drainCommands(connection, session, CommandType::CONTROL_ONLY); | 
|  | }, | 
|  | rpcFields->mFds.get()); | 
|  | 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. | 
|  | return OK; | 
|  | } | 
|  |  | 
|  | LOG_ALWAYS_FATAL_IF(reply == nullptr, "Reply parcel must be used for synchronous transaction."); | 
|  |  | 
|  | return waitForReply(connection, session, reply); | 
|  | } | 
|  |  | 
|  | static void cleanup_reply_data(const uint8_t* data, size_t dataSize, const binder_size_t* objects, | 
|  | size_t objectsCount) { | 
|  | delete[] const_cast<uint8_t*>(data); | 
|  | (void)dataSize; | 
|  | LOG_ALWAYS_FATAL_IF(objects != nullptr); | 
|  | (void)objectsCount; | 
|  | } | 
|  |  | 
|  | status_t RpcState::waitForReply(const sp<RpcSession::RpcConnection>& connection, | 
|  | const sp<RpcSession>& session, Parcel* reply) { | 
|  | std::vector<std::variant<base::unique_fd, base::borrowed_fd>> ancillaryFds; | 
|  | RpcWireHeader command; | 
|  | while (true) { | 
|  | iovec iov{&command, sizeof(command)}; | 
|  | if (status_t status = rpcRec(connection, session, "command header (for reply)", &iov, 1, | 
|  | enableAncillaryFds(session->getFileDescriptorTransportMode()) | 
|  | ? &ancillaryFds | 
|  | : nullptr); | 
|  | status != OK) | 
|  | return status; | 
|  |  | 
|  | if (command.command == RPC_COMMAND_REPLY) break; | 
|  |  | 
|  | if (status_t status = processCommand(connection, session, command, CommandType::ANY, | 
|  | std::move(ancillaryFds)); | 
|  | status != OK) | 
|  | return status; | 
|  |  | 
|  | // Reset to avoid spurious use-after-move warning from clang-tidy. | 
|  | ancillaryFds = decltype(ancillaryFds)(); | 
|  | } | 
|  |  | 
|  | const size_t rpcReplyWireSize = RpcWireReply::wireSize(session->getProtocolVersion().value()); | 
|  |  | 
|  | if (command.bodySize < rpcReplyWireSize) { | 
|  | ALOGE("Expecting %zu but got %" PRId32 " bytes for RpcWireReply. Terminating!", | 
|  | sizeof(RpcWireReply), command.bodySize); | 
|  | (void)session->shutdownAndWait(false); | 
|  | return BAD_VALUE; | 
|  | } | 
|  |  | 
|  | RpcWireReply rpcReply; | 
|  | memset(&rpcReply, 0, sizeof(RpcWireReply)); // zero because of potential short read | 
|  |  | 
|  | CommandData data(command.bodySize - rpcReplyWireSize); | 
|  | if (!data.valid()) return NO_MEMORY; | 
|  |  | 
|  | iovec iovs[]{ | 
|  | {&rpcReply, rpcReplyWireSize}, | 
|  | {data.data(), data.size()}, | 
|  | }; | 
|  | if (status_t status = rpcRec(connection, session, "reply body", iovs, arraysize(iovs), nullptr); | 
|  | status != OK) | 
|  | return status; | 
|  |  | 
|  | if (rpcReply.status != OK) return rpcReply.status; | 
|  |  | 
|  | Span<const uint8_t> parcelSpan = {data.data(), data.size()}; | 
|  | Span<const uint32_t> objectTableSpan; | 
|  | if (session->getProtocolVersion().value() >= | 
|  | RPC_WIRE_PROTOCOL_VERSION_RPC_HEADER_FEATURE_EXPLICIT_PARCEL_SIZE) { | 
|  | std::optional<Span<const uint8_t>> objectTableBytes = | 
|  | parcelSpan.splitOff(rpcReply.parcelDataSize); | 
|  | if (!objectTableBytes.has_value()) { | 
|  | ALOGE("Parcel size larger than available bytes: %" PRId32 " vs %zu. Terminating!", | 
|  | rpcReply.parcelDataSize, parcelSpan.byteSize()); | 
|  | (void)session->shutdownAndWait(false); | 
|  | return BAD_VALUE; | 
|  | } | 
|  | std::optional<Span<const uint32_t>> maybeSpan = | 
|  | objectTableBytes->reinterpret<const uint32_t>(); | 
|  | if (!maybeSpan.has_value()) { | 
|  | ALOGE("Bad object table size inferred from RpcWireReply. Saw bodySize=%" PRId32 | 
|  | " sizeofHeader=%zu parcelSize=%" PRId32 " objectTableBytesSize=%zu. Terminating!", | 
|  | command.bodySize, rpcReplyWireSize, rpcReply.parcelDataSize, | 
|  | objectTableBytes->size); | 
|  | return BAD_VALUE; | 
|  | } | 
|  | objectTableSpan = *maybeSpan; | 
|  | } | 
|  |  | 
|  | data.release(); | 
|  | return reply->rpcSetDataReference(session, parcelSpan.data, parcelSpan.size, | 
|  | objectTableSpan.data, objectTableSpan.size, | 
|  | std::move(ancillaryFds), cleanup_reply_data); | 
|  | } | 
|  |  | 
|  | status_t RpcState::sendDecStrongToTarget(const sp<RpcSession::RpcConnection>& connection, | 
|  | const sp<RpcSession>& session, uint64_t addr, | 
|  | size_t target) { | 
|  | RpcDecStrong body = { | 
|  | .address = RpcWireAddress::fromRaw(addr), | 
|  | }; | 
|  |  | 
|  | { | 
|  | RpcMutexLockGuard _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 %" PRIu64, addr); | 
|  |  | 
|  | LOG_ALWAYS_FATAL_IF(it->second.timesRecd < target, "Can't dec count of %zu to %zu.", | 
|  | it->second.timesRecd, target); | 
|  |  | 
|  | // typically this happens when multiple threads send dec refs at the | 
|  | // same time - the transactions will get combined automatically | 
|  | if (it->second.timesRecd == target) return OK; | 
|  |  | 
|  | body.amount = it->second.timesRecd - target; | 
|  | it->second.timesRecd = target; | 
|  |  | 
|  | LOG_ALWAYS_FATAL_IF(nullptr != tryEraseNode(it), | 
|  | "Bad state. RpcState shouldn't own received binder"); | 
|  | } | 
|  |  | 
|  | RpcWireHeader cmd = { | 
|  | .command = RPC_COMMAND_DEC_STRONG, | 
|  | .bodySize = sizeof(RpcDecStrong), | 
|  | }; | 
|  | iovec iovs[]{{&cmd, sizeof(cmd)}, {&body, sizeof(body)}}; | 
|  | return rpcSend(connection, session, "dec ref", iovs, arraysize(iovs), std::nullopt); | 
|  | } | 
|  |  | 
|  | 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()); | 
|  |  | 
|  | std::vector<std::variant<base::unique_fd, base::borrowed_fd>> ancillaryFds; | 
|  | RpcWireHeader command; | 
|  | iovec iov{&command, sizeof(command)}; | 
|  | if (status_t status = | 
|  | rpcRec(connection, session, "command header (for server)", &iov, 1, | 
|  | enableAncillaryFds(session->getFileDescriptorTransportMode()) ? &ancillaryFds | 
|  | : nullptr); | 
|  | status != OK) | 
|  | return status; | 
|  |  | 
|  | return processCommand(connection, session, command, type, std::move(ancillaryFds)); | 
|  | } | 
|  |  | 
|  | status_t RpcState::drainCommands(const sp<RpcSession::RpcConnection>& connection, | 
|  | const sp<RpcSession>& session, CommandType type) { | 
|  | while (true) { | 
|  | status_t status = connection->rpcTransport->pollRead(); | 
|  | if (status == WOULD_BLOCK) break; | 
|  | if (status != OK) return status; | 
|  |  | 
|  | 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, | 
|  | std::vector<std::variant<base::unique_fd, base::borrowed_fd>>&& ancillaryFds) { | 
|  | #ifdef BINDER_WITH_KERNEL_IPC | 
|  | IPCThreadState* kernelBinderState = IPCThreadState::selfOrNull(); | 
|  | IPCThreadState::SpGuard spGuard{ | 
|  | .address = __builtin_frame_address(0), | 
|  | .context = "processing binder RPC command (where RpcServer::setPerSessionRootObject is " | 
|  | "used to distinguish callers)", | 
|  | }; | 
|  | const IPCThreadState::SpGuard* origGuard; | 
|  | if (kernelBinderState != nullptr) { | 
|  | origGuard = kernelBinderState->pushGetCallingSpGuard(&spGuard); | 
|  | } | 
|  |  | 
|  | base::ScopeGuard guardUnguard = [&]() { | 
|  | if (kernelBinderState != nullptr) { | 
|  | kernelBinderState->restoreGetCallingSpGuard(origGuard); | 
|  | } | 
|  | }; | 
|  | #endif // BINDER_WITH_KERNEL_IPC | 
|  |  | 
|  | switch (command.command) { | 
|  | case RPC_COMMAND_TRANSACT: | 
|  | if (type != CommandType::ANY) return BAD_TYPE; | 
|  | return processTransact(connection, session, command, std::move(ancillaryFds)); | 
|  | 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, | 
|  | std::vector<std::variant<base::unique_fd, base::borrowed_fd>>&& ancillaryFds) { | 
|  | LOG_ALWAYS_FATAL_IF(command.command != RPC_COMMAND_TRANSACT, "command: %d", command.command); | 
|  |  | 
|  | CommandData transactionData(command.bodySize); | 
|  | if (!transactionData.valid()) { | 
|  | return NO_MEMORY; | 
|  | } | 
|  | iovec iov{transactionData.data(), transactionData.size()}; | 
|  | if (status_t status = rpcRec(connection, session, "transaction body", &iov, 1, nullptr); | 
|  | status != OK) | 
|  | return status; | 
|  |  | 
|  | return processTransactInternal(connection, session, std::move(transactionData), | 
|  | std::move(ancillaryFds)); | 
|  | } | 
|  |  | 
|  | static void do_nothing_to_transact_data(const uint8_t* data, size_t dataSize, | 
|  | const binder_size_t* objects, size_t objectsCount) { | 
|  | (void)data; | 
|  | (void)dataSize; | 
|  | (void)objects; | 
|  | (void)objectsCount; | 
|  | } | 
|  |  | 
|  | status_t RpcState::processTransactInternal( | 
|  | const sp<RpcSession::RpcConnection>& connection, const sp<RpcSession>& session, | 
|  | CommandData transactionData, | 
|  | std::vector<std::variant<base::unique_fd, base::borrowed_fd>>&& ancillaryFds) { | 
|  | // 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> target; | 
|  | 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()); | 
|  |  | 
|  | uint64_t addr = RpcWireAddress::toRaw(transaction->address); | 
|  | bool oneway = transaction->flags & IBinder::FLAG_ONEWAY; | 
|  |  | 
|  | status_t replyStatus = OK; | 
|  | if (addr != 0) { | 
|  | if (!target) { | 
|  | replyStatus = onBinderEntering(session, addr, &target); | 
|  | } | 
|  |  | 
|  | 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 %" PRIu64 ". Terminating!", | 
|  | addr); | 
|  | (void)session->shutdownAndWait(false); | 
|  | replyStatus = BAD_VALUE; | 
|  | } else if (target->localBinder() == nullptr) { | 
|  | ALOGE("Unknown binder address or non-local binder, not address %" PRIu64 | 
|  | ". Terminating!", | 
|  | addr); | 
|  | (void)session->shutdownAndWait(false); | 
|  | replyStatus = BAD_VALUE; | 
|  | } else if (oneway) { | 
|  | RpcMutexUniqueLock _l(mNodeMutex); | 
|  | auto it = mNodeForAddress.find(addr); | 
|  | if (it->second.binder.promote() != target) { | 
|  | ALOGE("Binder became invalid during transaction. Bad client? %" PRIu64, addr); | 
|  | 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 %" PRIu64 " on %" PRIu64 " (%zu pending)", | 
|  | transaction->asyncNumber, addr, 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) { | 
|  | Span<const uint8_t> parcelSpan = {transaction->data, | 
|  | transactionData.size() - | 
|  | offsetof(RpcWireTransaction, data)}; | 
|  | Span<const uint32_t> objectTableSpan; | 
|  | if (session->getProtocolVersion().value() > | 
|  | RPC_WIRE_PROTOCOL_VERSION_RPC_HEADER_FEATURE_EXPLICIT_PARCEL_SIZE) { | 
|  | std::optional<Span<const uint8_t>> objectTableBytes = | 
|  | parcelSpan.splitOff(transaction->parcelDataSize); | 
|  | if (!objectTableBytes.has_value()) { | 
|  | ALOGE("Parcel size (%" PRId32 ") greater than available bytes (%zu). Terminating!", | 
|  | transaction->parcelDataSize, parcelSpan.byteSize()); | 
|  | (void)session->shutdownAndWait(false); | 
|  | return BAD_VALUE; | 
|  | } | 
|  | std::optional<Span<const uint32_t>> maybeSpan = | 
|  | objectTableBytes->reinterpret<const uint32_t>(); | 
|  | if (!maybeSpan.has_value()) { | 
|  | ALOGE("Bad object table size inferred from RpcWireTransaction. Saw bodySize=%zu " | 
|  | "sizeofHeader=%zu parcelSize=%" PRId32 | 
|  | " objectTableBytesSize=%zu. Terminating!", | 
|  | transactionData.size(), sizeof(RpcWireTransaction), | 
|  | transaction->parcelDataSize, objectTableBytes->size); | 
|  | return BAD_VALUE; | 
|  | } | 
|  | objectTableSpan = *maybeSpan; | 
|  | } | 
|  |  | 
|  | 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. | 
|  |  | 
|  | replyStatus = | 
|  | data.rpcSetDataReference(session, parcelSpan.data, parcelSpan.size, | 
|  | objectTableSpan.data, objectTableSpan.size, | 
|  | std::move(ancillaryFds), do_nothing_to_transact_data); | 
|  | // Reset to avoid spurious use-after-move warning from clang-tidy. | 
|  | ancillaryFds = std::remove_reference<decltype(ancillaryFds)>::type(); | 
|  |  | 
|  | if (replyStatus == OK) { | 
|  | 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->getMaxIncomingThreads()); | 
|  | 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 = reply.writeByteVector(session->mId); | 
|  | break; | 
|  | } | 
|  | default: { | 
|  | sp<RpcServer> server = session->server(); | 
|  | if (server) { | 
|  | switch (transaction->code) { | 
|  | case RPC_SPECIAL_TRANSACT_GET_ROOT: { | 
|  | sp<IBinder> root = session->mSessionSpecificRootObject | 
|  | ?: server->getRootObject(); | 
|  | replyStatus = reply.writeStrongBinder(root); | 
|  | 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 %" PRIu64 " on %" PRIu64, | 
|  | transaction->asyncNumber, addr); | 
|  |  | 
|  | // 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. | 
|  | { | 
|  | RpcMutexUniqueLock _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 %" PRIu64 " on %" PRIu64, | 
|  | it->second.asyncNumber, addr); | 
|  |  | 
|  | // 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); | 
|  | LOG_ALWAYS_FATAL_IF(target != todo.ref, | 
|  | "async list should be associated with a binder"); | 
|  |  | 
|  | it->second.asyncTodo.pop(); | 
|  | goto processTransactInternalTailCall; | 
|  | } | 
|  | } | 
|  |  | 
|  | // done processing all the async commands on this binder that we can, so | 
|  | // write decstrongs on the binder | 
|  | if (addr != 0 && replyStatus == OK) { | 
|  | return flushExcessBinderRefs(session, addr, target); | 
|  | } | 
|  |  | 
|  | return OK; | 
|  | } | 
|  |  | 
|  | // Binder refs are flushed for oneway calls only after all calls which are | 
|  | // built up are executed. Otherwise, they fill up the binder buffer. | 
|  | if (addr != 0 && replyStatus == OK) { | 
|  | replyStatus = flushExcessBinderRefs(session, addr, target); | 
|  | } | 
|  |  | 
|  | std::string errorMsg; | 
|  | if (status_t status = validateParcel(session, reply, &errorMsg); status != OK) { | 
|  | ALOGE("Reply Parcel failed validation: %s", errorMsg.c_str()); | 
|  | // Forward the error to the client of the transaction. | 
|  | reply.freeData(); | 
|  | reply.markForRpc(session); | 
|  | replyStatus = status; | 
|  | } | 
|  |  | 
|  | auto* rpcFields = reply.maybeRpcFields(); | 
|  | LOG_ALWAYS_FATAL_IF(rpcFields == nullptr); | 
|  |  | 
|  | const size_t rpcReplyWireSize = RpcWireReply::wireSize(session->getProtocolVersion().value()); | 
|  |  | 
|  | Span<const uint32_t> objectTableSpan = Span<const uint32_t>{rpcFields->mObjectPositions.data(), | 
|  | rpcFields->mObjectPositions.size()}; | 
|  |  | 
|  | uint32_t bodySize; | 
|  | LOG_ALWAYS_FATAL_IF(__builtin_add_overflow(rpcReplyWireSize, reply.dataSize(), &bodySize) || | 
|  | __builtin_add_overflow(objectTableSpan.byteSize(), bodySize, | 
|  | &bodySize), | 
|  | "Too much data for reply %zu", reply.dataSize()); | 
|  | RpcWireHeader cmdReply{ | 
|  | .command = RPC_COMMAND_REPLY, | 
|  | .bodySize = bodySize, | 
|  | }; | 
|  | RpcWireReply rpcReply{ | 
|  | .status = replyStatus, | 
|  | // NOTE: Not necessarily written to socket depending on session | 
|  | // version. | 
|  | // NOTE: bodySize didn't overflow => this cast is safe | 
|  | .parcelDataSize = static_cast<uint32_t>(reply.dataSize()), | 
|  | .reserved = {0, 0, 0}, | 
|  | }; | 
|  | iovec iovs[]{ | 
|  | {&cmdReply, sizeof(RpcWireHeader)}, | 
|  | {&rpcReply, rpcReplyWireSize}, | 
|  | {const_cast<uint8_t*>(reply.data()), reply.dataSize()}, | 
|  | objectTableSpan.toIovec(), | 
|  | }; | 
|  | return rpcSend(connection, session, "reply", iovs, arraysize(iovs), std::nullopt, | 
|  | rpcFields->mFds.get()); | 
|  | } | 
|  |  | 
|  | 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); | 
|  |  | 
|  | if (command.bodySize != sizeof(RpcDecStrong)) { | 
|  | ALOGE("Expecting %zu but got %" PRId32 " bytes for RpcDecStrong. Terminating!", | 
|  | sizeof(RpcDecStrong), command.bodySize); | 
|  | (void)session->shutdownAndWait(false); | 
|  | return BAD_VALUE; | 
|  | } | 
|  |  | 
|  | RpcDecStrong body; | 
|  | iovec iov{&body, sizeof(RpcDecStrong)}; | 
|  | if (status_t status = rpcRec(connection, session, "dec ref body", &iov, 1, nullptr); | 
|  | status != OK) | 
|  | return status; | 
|  |  | 
|  | uint64_t addr = RpcWireAddress::toRaw(body.address); | 
|  | RpcMutexUniqueLock _l(mNodeMutex); | 
|  | auto it = mNodeForAddress.find(addr); | 
|  | if (it == mNodeForAddress.end()) { | 
|  | ALOGE("Unknown binder address %" PRIu64 " for dec strong.", addr); | 
|  | return OK; | 
|  | } | 
|  |  | 
|  | sp<IBinder> target = it->second.binder.promote(); | 
|  | if (target == nullptr) { | 
|  | ALOGE("While requesting dec strong, binder has been deleted at address %" PRIu64 | 
|  | ". Terminating!", | 
|  | addr); | 
|  | _l.unlock(); | 
|  | (void)session->shutdownAndWait(false); | 
|  | return BAD_VALUE; | 
|  | } | 
|  |  | 
|  | if (it->second.timesSent < body.amount) { | 
|  | ALOGE("Record of sending binder %zu times, but requested decStrong for %" PRIu64 " of %u", | 
|  | it->second.timesSent, addr, body.amount); | 
|  | return OK; | 
|  | } | 
|  |  | 
|  | LOG_ALWAYS_FATAL_IF(it->second.sentRef == nullptr, "Inconsistent state, lost ref for %" PRIu64, | 
|  | addr); | 
|  |  | 
|  | LOG_RPC_DETAIL("Processing dec strong of %" PRIu64 " by %u from %zu", addr, body.amount, | 
|  | it->second.timesSent); | 
|  |  | 
|  | it->second.timesSent -= body.amount; | 
|  | sp<IBinder> tempHold = tryEraseNode(it); | 
|  | _l.unlock(); | 
|  | tempHold = nullptr; // destructor may make binder calls on this session | 
|  |  | 
|  | return OK; | 
|  | } | 
|  |  | 
|  | status_t RpcState::validateParcel(const sp<RpcSession>& session, const Parcel& parcel, | 
|  | std::string* errorMsg) { | 
|  | auto* rpcFields = parcel.maybeRpcFields(); | 
|  | if (rpcFields == nullptr) { | 
|  | *errorMsg = "Parcel not crafted for RPC call"; | 
|  | return BAD_TYPE; | 
|  | } | 
|  |  | 
|  | if (rpcFields->mSession != session) { | 
|  | *errorMsg = "Parcel's session doesn't match"; | 
|  | return BAD_TYPE; | 
|  | } | 
|  |  | 
|  | uint32_t protocolVersion = session->getProtocolVersion().value(); | 
|  | if (protocolVersion < RPC_WIRE_PROTOCOL_VERSION_RPC_HEADER_FEATURE_EXPLICIT_PARCEL_SIZE && | 
|  | !rpcFields->mObjectPositions.empty()) { | 
|  | *errorMsg = StringPrintf("Parcel has attached objects but the session's protocol version " | 
|  | "(%" PRIu32 ") is too old, must be at least %" PRIu32, | 
|  | protocolVersion, | 
|  | RPC_WIRE_PROTOCOL_VERSION_RPC_HEADER_FEATURE_EXPLICIT_PARCEL_SIZE); | 
|  | return BAD_VALUE; | 
|  | } | 
|  |  | 
|  | if (rpcFields->mFds && !rpcFields->mFds->empty()) { | 
|  | switch (session->getFileDescriptorTransportMode()) { | 
|  | case RpcSession::FileDescriptorTransportMode::NONE: | 
|  | *errorMsg = | 
|  | "Parcel has file descriptors, but no file descriptor transport is enabled"; | 
|  | return FDS_NOT_ALLOWED; | 
|  | case RpcSession::FileDescriptorTransportMode::UNIX: { | 
|  | constexpr size_t kMaxFdsPerMsg = 253; | 
|  | if (rpcFields->mFds->size() > kMaxFdsPerMsg) { | 
|  | *errorMsg = StringPrintf("Too many file descriptors in Parcel for unix " | 
|  | "domain socket: %zu (max is %zu)", | 
|  | rpcFields->mFds->size(), kMaxFdsPerMsg); | 
|  | return BAD_VALUE; | 
|  | } | 
|  | } | 
|  | } | 
|  | } | 
|  |  | 
|  | return OK; | 
|  | } | 
|  |  | 
|  | sp<IBinder> RpcState::tryEraseNode(std::map<uint64_t, 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 |