| /* |
| * Copyright 2018, 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 "commander.h" |
| |
| #include "commands/command.h" |
| #include "log.h" |
| |
| #include <errno.h> |
| #pragma clang diagnostic push |
| #pragma clang diagnostic ignored "-Wunused-function" |
| #include <qemu_pipe.h> |
| #pragma clang diagnostic pop |
| #include <string.h> |
| #include <sys/socket.h> |
| #include <sys/types.h> |
| |
| static const char kQemuPipeName[] = "qemud:network"; |
| |
| // How much space to use for each command received |
| static const size_t kReceiveSpace = 1024; |
| // The maximum amount of bytes to keep in the receive buffer for a single |
| // command before dropping data. |
| static const size_t kMaxReceiveBufferSize = 65536; |
| |
| Commander::Commander() : mPipeFd(-1) { |
| } |
| |
| Commander::~Commander() { |
| closePipe(); |
| } |
| |
| Result Commander::init() { |
| if (mPipeFd != -1) { |
| return Result::error("Commander already initialized"); |
| } |
| |
| openPipe(); |
| |
| return Result::success(); |
| } |
| |
| void Commander::registerCommand(const char* commandStr, Command* command) { |
| mCommands[commandStr] = command; |
| } |
| |
| void Commander::getPollData(std::vector<pollfd>* fds) const { |
| if (mPipeFd != -1) { |
| fds->push_back(pollfd{mPipeFd, POLLIN, 0}); |
| } |
| } |
| |
| Pollable::Timestamp Commander::getTimeout() const { |
| return mDeadline; |
| } |
| |
| bool Commander::onReadAvailable(int /*fd*/, int* /*status*/) { |
| size_t offset = mReceiveBuffer.size(); |
| mReceiveBuffer.resize(offset + kReceiveSpace); |
| if (mReceiveBuffer.size() > kMaxReceiveBufferSize) { |
| // We have buffered too much data, this should never happen but as a |
| // seurity measure let's just drop everything we have and keep |
| // receiving. Maybe the situation will improve. |
| mReceiveBuffer.resize(kReceiveSpace); |
| offset = 0; |
| } |
| while (true) { |
| int status = ::read(mPipeFd, &mReceiveBuffer[offset], kReceiveSpace); |
| |
| if (status < 0) { |
| if (errno == EINTR) { |
| // We got an interrupt, try again |
| continue; |
| } |
| LOGE("Commander failed to receive on pipe: %s", strerror(errno)); |
| // Don't exit the looper because of this, keep trying |
| return true; |
| } |
| size_t length = static_cast<size_t>(status); |
| mReceiveBuffer.resize(offset + length); |
| |
| while (true) { |
| auto endline = std::find(mReceiveBuffer.begin(), |
| mReceiveBuffer.end(), |
| '\n'); |
| if (endline == mReceiveBuffer.end()) { |
| // No endline in sight, keep waiting and buffering |
| return true; |
| } |
| |
| *endline = '\0'; |
| |
| char* args = ::strchr(mReceiveBuffer.data(), ' '); |
| if (args) { |
| *args++ = '\0'; |
| } |
| auto command = mCommands.find(mReceiveBuffer.data()); |
| |
| if (command != mCommands.end()) { |
| command->second->onCommand(mReceiveBuffer.data(), args); |
| } |
| // Now that we have processed this line let's remove it from the |
| // receive buffer |
| ++endline; |
| if (endline == mReceiveBuffer.end()) { |
| mReceiveBuffer.clear(); |
| // There can be nothing left, just return |
| return true; |
| } else { |
| mReceiveBuffer.erase(mReceiveBuffer.begin(), endline + 1); |
| // There may be another line in there so keep looping and look |
| // for more |
| } |
| } |
| return true; |
| } |
| } |
| |
| bool Commander::onClose(int /*fd*/, int* /*status*/) { |
| // Pipe was closed from the other end, close it on our side and re-open |
| closePipe(); |
| openPipe(); |
| return true; |
| } |
| |
| bool Commander::onTimeout(int* /*status*/) { |
| if (mPipeFd == -1) { |
| openPipe(); |
| } |
| return true; |
| } |
| |
| void Commander::openPipe() { |
| mPipeFd = qemu_pipe_open(kQemuPipeName); |
| if (mPipeFd == -1) { |
| LOGE("Failed to open QEMU pipe '%s': %s", |
| kQemuPipeName, |
| strerror(errno)); |
| // Try again in the future |
| mDeadline = Pollable::Clock::now() + std::chrono::minutes(1); |
| } else { |
| mDeadline = Pollable::Timestamp::max(); |
| } |
| } |
| |
| void Commander::closePipe() { |
| if (mPipeFd != -1) { |
| ::close(mPipeFd); |
| mPipeFd = -1; |
| } |
| } |