| /* |
| * Copyright (C) 2019 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 qemu_pipe.h before sysdeps, since it has inlined references to open, read, write. |
| #include <qemu_pipe.h> |
| |
| #define TRACE_TAG TRANSPORT |
| #include "socket_spec.h" |
| #include "sysdeps.h" |
| #include "transport.h" |
| |
| #include <android-base/properties.h> |
| |
| #include "adb_io.h" |
| #include "adb_trace.h" |
| #include "adb_unique_fd.h" |
| |
| /* A worker thread that monitors host connections, and registers a transport for |
| * every new host connection. This thread replaces server_socket_thread on |
| * condition that adbd daemon runs inside the emulator, and emulator uses QEMUD |
| * pipe to communicate with adbd daemon inside the guest. This is done in order |
| * to provide more robust communication channel between ADB host and guest. The |
| * main issue with server_socket_thread approach is that it runs on top of TCP, |
| * and thus is sensitive to network disruptions. For instance, the |
| * ConnectionManager may decide to reset all network connections, in which case |
| * the connection between ADB host and guest will be lost. To make ADB traffic |
| * independent from the network, we use here 'adb' QEMUD service to transfer data |
| * between the host, and the guest. See external/qemu/android/adb-*.* that |
| * implements the emulator's side of the protocol. Another advantage of using |
| * QEMUD approach is that ADB will be up much sooner, since it doesn't depend |
| * anymore on network being set up. |
| * The guest side of the protocol contains the following phases: |
| * - Connect with adb QEMUD service. In this phase a handle to 'adb' QEMUD service |
| * is opened, and it becomes clear whether or not emulator supports that |
| * protocol. |
| * - Wait for the ADB host to create connection with the guest. This is done by |
| * sending an 'accept' request to the adb QEMUD service, and waiting on |
| * response. |
| * - When new ADB host connection is accepted, the connection with adb QEMUD |
| * service is registered as the transport, and a 'start' request is sent to the |
| * adb QEMUD service, indicating that the guest is ready to receive messages. |
| * Note that the guest will ignore messages sent down from the emulator before |
| * the transport registration is completed. That's why we need to send the |
| * 'start' request after the transport is registered. |
| */ |
| void qemu_socket_thread(std::string_view addr) { |
| /* 'accept' request to the adb QEMUD service. */ |
| static const char _accept_req[] = "accept"; |
| /* 'start' request to the adb QEMUD service. */ |
| static const char _start_req[] = "start"; |
| /* 'ok' reply from the adb QEMUD service. */ |
| static const char _ok_resp[] = "ok"; |
| |
| char tmp[256]; |
| char con_name[32]; |
| |
| adb_thread_setname("qemu socket"); |
| D("transport: qemu_socket_thread() starting"); |
| |
| std::string error; |
| int port = get_host_socket_spec_port(addr, &error); |
| if (port == -1) { |
| port = DEFAULT_ADB_LOCAL_TRANSPORT_PORT; |
| } |
| |
| /* adb QEMUD service connection request. */ |
| snprintf(con_name, sizeof(con_name), "pipe:qemud:adb:%d", port); |
| |
| /* Connect to the adb QEMUD service. */ |
| unique_fd fd(qemu_pipe_open(con_name)); |
| if (fd < 0) { |
| /* This could be an older version of the emulator, that doesn't |
| * implement adb QEMUD service. Fall back to the old TCP way. */ |
| D("adb service is not available. Falling back to TCP socket."); |
| std::thread(server_socket_thread, adb_listen, addr).detach(); |
| return; |
| } |
| |
| while (true) { |
| /* |
| * Wait till the host creates a new connection. |
| */ |
| |
| /* Send the 'accept' request. */ |
| if (WriteFdExactly(fd.get(), _accept_req, strlen(_accept_req))) { |
| /* Wait for the response. In the response we expect 'ok' on success, |
| * or 'ko' on failure. */ |
| if (!ReadFdExactly(fd.get(), tmp, 2) || memcmp(tmp, _ok_resp, 2)) { |
| D("Accepting ADB host connection has failed."); |
| } else { |
| /* Host is connected. Register the transport, and start the |
| * exchange. */ |
| std::string serial = android::base::StringPrintf("host-%d", fd.get()); |
| WriteFdExactly(fd.get(), _start_req, strlen(_start_req)); |
| register_socket_transport( |
| std::move(fd), std::move(serial), port, 1, |
| [](atransport*) { return ReconnectResult::Abort; }, false); |
| } |
| |
| /* Prepare for accepting of the next ADB host connection. */ |
| fd.reset(qemu_pipe_open(con_name)); |
| if (fd < 0) { |
| D("adb service become unavailable."); |
| return; |
| } |
| } else { |
| D("Unable to send the '%s' request to ADB service.", _accept_req); |
| return; |
| } |
| } |
| D("transport: qemu_socket_thread() exiting"); |
| return; |
| } |
| |
| // If adbd is running inside the emulator, it will normally use QEMUD pipe (aka |
| // goldfish) as the transport. This can either be explicitly set by the |
| // service.adb.transport property, or be inferred from ro.kernel.qemu that is |
| // set to "1" for ranchu/goldfish. |
| bool use_qemu_goldfish() { |
| // Legacy way to detect if adbd should use the goldfish pipe is to check for |
| // ro.kernel.qemu, keep that behaviour for backward compatibility. |
| if (android::base::GetBoolProperty("ro.kernel.qemu", false)) { |
| return true; |
| } |
| // If service.adb.transport is present and is set to "goldfish", use the |
| // QEMUD pipe. |
| if (android::base::GetProperty("service.adb.transport", "") == "goldfish") { |
| return true; |
| } |
| return false; |
| } |