Add socket communication between recovery and minadbd
This cl adds a socket pair to support the communication between recovery
and minadbd. Therefore, minadbd will be able to issue multiple commands
to recovery and get back the status of each command.
This cl also switches the adb sideload from the recovery menu to use
this protocol; and moves minadbd to a separate binary.
Bug: 130166585
Test: sideload a package
Change-Id: I80d36d5c4e6fe1ae3ea23640907bc50c0dc0d482
diff --git a/install/adb_install.cpp b/install/adb_install.cpp
index 5296ff6..dc7ee0b 100644
--- a/install/adb_install.cpp
+++ b/install/adb_install.cpp
@@ -21,23 +21,265 @@
#include <signal.h>
#include <stdlib.h>
#include <string.h>
+#include <sys/epoll.h>
+#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
+#include <atomic>
+#include <functional>
+#include <map>
+
+#include <android-base/file.h>
#include <android-base/logging.h>
+#include <android-base/memory.h>
#include <android-base/properties.h>
+#include <android-base/strings.h>
+#include <android-base/unique_fd.h>
#include "fuse_sideload.h"
#include "install/install.h"
+#include "minadbd_types.h"
#include "recovery_ui/ui.h"
+using CommandFunction = std::function<bool()>;
+
static bool SetUsbConfig(const std::string& state) {
android::base::SetProperty("sys.usb.config", state);
return android::base::WaitForProperty("sys.usb.state", state);
}
+// Parses the minadbd command in |message|; returns MinadbdCommands::kError upon errors.
+static MinadbdCommands ParseMinadbdCommands(const std::string& message) {
+ if (!android::base::StartsWith(message, kMinadbdCommandPrefix)) {
+ LOG(ERROR) << "Failed to parse command in message " << message;
+ return MinadbdCommands::kError;
+ }
+
+ auto cmd_code_string = message.substr(strlen(kMinadbdCommandPrefix));
+ auto cmd_code = android::base::get_unaligned<uint32_t>(cmd_code_string.c_str());
+ if (cmd_code >= static_cast<uint32_t>(MinadbdCommands::kError)) {
+ LOG(ERROR) << "Unsupported command code: " << cmd_code;
+ return MinadbdCommands::kError;
+ }
+
+ return static_cast<MinadbdCommands>(cmd_code);
+}
+
+static bool WriteStatusToFd(MinadbdCommandStatus status, int fd) {
+ char message[kMinadbdMessageSize];
+ memcpy(message, kMinadbdStatusPrefix, strlen(kMinadbdStatusPrefix));
+ android::base::put_unaligned(message + strlen(kMinadbdStatusPrefix), status);
+
+ if (!android::base::WriteFully(fd, message, kMinadbdMessageSize)) {
+ PLOG(ERROR) << "Failed to write message " << message;
+ return false;
+ }
+ return true;
+}
+
+// Installs the package from FUSE. Returns true if the installation succeeds, and false otherwise.
+static bool AdbInstallPackageHandler(bool* wipe_cache, RecoveryUI* ui, int* result) {
+ // How long (in seconds) we wait for the package path to be ready. It doesn't need to be too long
+ // because the minadbd service has already issued an install command. FUSE_SIDELOAD_HOST_PATHNAME
+ // will start to exist once the host connects and starts serving a package. Poll for its
+ // appearance. (Note that inotify doesn't work with FUSE.)
+ constexpr int ADB_INSTALL_TIMEOUT = 15;
+ *result = INSTALL_ERROR;
+ for (int i = 0; i < ADB_INSTALL_TIMEOUT; ++i) {
+ struct stat st;
+ if (stat(FUSE_SIDELOAD_HOST_PATHNAME, &st) != 0) {
+ if (errno == ENOENT && i < ADB_INSTALL_TIMEOUT - 1) {
+ sleep(1);
+ continue;
+ } else {
+ ui->Print("\nTimed out waiting for fuse to be ready.\n\n");
+ break;
+ }
+ }
+ *result = install_package(FUSE_SIDELOAD_HOST_PATHNAME, wipe_cache, false, 0, ui);
+ break;
+ }
+
+ // Calling stat() on this magic filename signals the FUSE to exit.
+ struct stat st;
+ stat(FUSE_SIDELOAD_HOST_EXIT_PATHNAME, &st);
+ return *result == INSTALL_SUCCESS;
+}
+
+// Parses and executes the command from minadbd. Returns false if we enter an invalid state so that
+// the caller can kill the minadbd service properly.
+static bool HandleMessageFromMinadbd(
+ int socket_fd, const std::map<MinadbdCommands, CommandFunction>& command_map) {
+ char buffer[kMinadbdMessageSize];
+ if (!android::base::ReadFully(socket_fd, buffer, kMinadbdMessageSize)) {
+ PLOG(ERROR) << "Failed to read message from minadbd";
+ return false;
+ }
+
+ std::string message(buffer, buffer + kMinadbdMessageSize);
+ auto command_type = ParseMinadbdCommands(message);
+ if (command_type == MinadbdCommands::kError) {
+ return false;
+ }
+ if (command_map.find(command_type) == command_map.end()) {
+ LOG(ERROR) << "Unsupported command: "
+ << android::base::get_unaligned<unsigned int>(
+ message.substr(strlen(kMinadbdCommandPrefix)).c_str());
+ return false;
+ }
+
+ // We have received a valid command, execute the corresponding function.
+ const auto& command_func = command_map.at(command_type);
+ if (!command_func()) {
+ LOG(ERROR) << "Failed to execute command " << static_cast<unsigned int>(command_type);
+ return WriteStatusToFd(MinadbdCommandStatus::kFailure, socket_fd);
+ }
+ return WriteStatusToFd(MinadbdCommandStatus::kSuccess, socket_fd);
+}
+
+// TODO(xunchang) add a wrapper function and kill the minadbd service there.
+static void ListenAndExecuteMinadbdCommands(
+ pid_t minadbd_pid, android::base::unique_fd&& socket_fd,
+ const std::map<MinadbdCommands, CommandFunction>& command_map) {
+ android::base::unique_fd epoll_fd(epoll_create1(O_CLOEXEC));
+ if (epoll_fd == -1) {
+ PLOG(ERROR) << "Failed to create epoll";
+ kill(minadbd_pid, SIGKILL);
+ return;
+ }
+
+ constexpr int EPOLL_MAX_EVENTS = 10;
+ struct epoll_event ev = {};
+ ev.events = EPOLLIN | EPOLLHUP;
+ ev.data.fd = socket_fd.get();
+ struct epoll_event events[EPOLL_MAX_EVENTS];
+ if (epoll_ctl(epoll_fd.get(), EPOLL_CTL_ADD, socket_fd.get(), &ev) == -1) {
+ PLOG(ERROR) << "Failed to add socket fd to epoll";
+ kill(minadbd_pid, SIGKILL);
+ return;
+ }
+
+ // Set the timeout to be 300s when waiting for minadbd commands.
+ constexpr int TIMEOUT_MILLIS = 300 * 1000;
+ while (true) {
+ // Poll for the status change of the socket_fd, and handle the message if the fd is ready to
+ // read.
+ int event_count =
+ TEMP_FAILURE_RETRY(epoll_wait(epoll_fd.get(), events, EPOLL_MAX_EVENTS, TIMEOUT_MILLIS));
+ if (event_count == -1) {
+ PLOG(ERROR) << "Failed to wait for epoll events";
+ kill(minadbd_pid, SIGKILL);
+ return;
+ }
+ if (event_count == 0) {
+ LOG(ERROR) << "Timeout waiting for messages from minadbd";
+ kill(minadbd_pid, SIGKILL);
+ return;
+ }
+
+ for (int n = 0; n < event_count; n++) {
+ if (events[n].events & EPOLLHUP) {
+ LOG(INFO) << "Socket has been closed";
+ kill(minadbd_pid, SIGKILL);
+ return;
+ }
+ if (!HandleMessageFromMinadbd(socket_fd.get(), command_map)) {
+ kill(minadbd_pid, SIGKILL);
+ return;
+ }
+ }
+ }
+}
+
+// Recovery starts minadbd service as a child process, and spawns another thread to listen for the
+// message from minadbd through a socket pair. Here is an example to execute one command from adb
+// host.
+// a. recovery b. listener thread c. minadbd service
+//
+// a1. create socket pair
+// a2. fork minadbd service
+// c3. wait for the adb commands
+// from host
+// c4. after receiving host commands:
+// 1) set up pre-condition (i.e.
+// start fuse for adb sideload)
+// 2) issue command through
+// socket.
+// 3) wait for result
+// a5. start listener thread
+// b6. listen for message from
+// minadbd in a loop.
+// b7. After receiving a minadbd
+// command from socket
+// 1) execute the command function
+// 2) send the result back to
+// minadbd
+// ......
+// c8. exit upon receiving the
+// result
+// a9. wait for listener thread
+// to exit.
+//
+// a10. wait for minadbd to
+// exit
+// b11. exit the listening loop
+//
+static void CreateMinadbdServiceAndExecuteCommands(
+ const std::map<MinadbdCommands, CommandFunction>& command_map) {
+ signal(SIGPIPE, SIG_IGN);
+
+ android::base::unique_fd recovery_socket;
+ android::base::unique_fd minadbd_socket;
+ if (!android::base::Socketpair(AF_UNIX, SOCK_STREAM, 0, &recovery_socket, &minadbd_socket)) {
+ PLOG(ERROR) << "Failed to create socket";
+ return;
+ }
+
+ pid_t child = fork();
+ if (child == -1) {
+ PLOG(ERROR) << "Failed to fork child process";
+ return;
+ }
+ if (child == 0) {
+ recovery_socket.reset();
+ execl("/system/bin/minadbd", "minadbd", "--socket_fd",
+ std::to_string(minadbd_socket.release()).c_str(), nullptr);
+
+ _exit(EXIT_FAILURE);
+ }
+
+ minadbd_socket.reset();
+
+ // We need to call SetUsbConfig() after forking minadbd service. Because the function waits for
+ // the usb state to be updated, which depends on sys.usb.ffs.ready=1 set in the adb daemon.
+ if (!SetUsbConfig("sideload")) {
+ LOG(ERROR) << "Failed to set usb config to sideload";
+ return;
+ }
+
+ std::thread listener_thread(ListenAndExecuteMinadbdCommands, child, std::move(recovery_socket),
+ std::ref(command_map));
+
+ if (listener_thread.joinable()) {
+ listener_thread.join();
+ }
+
+ int status;
+ waitpid(child, &status, 0);
+ if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
+ if (WEXITSTATUS(status) == MinadbdErrorCode::kMinadbdAdbVersionError) {
+ LOG(ERROR) << "\nYou need adb 1.0.32 or newer to sideload\nto this device.\n";
+ } else if (!WIFSIGNALED(status)) {
+ LOG(ERROR) << "\n(adbd status " << WEXITSTATUS(status) << ")";
+ }
+ }
+
+ signal(SIGPIPE, SIG_DFL);
+}
+
int apply_from_adb(bool* wipe_cache, RecoveryUI* ui) {
// Save the usb state to restore after the sideload operation.
std::string usb_state = android::base::GetProperty("sys.usb.state", "none");
@@ -51,66 +293,13 @@
"\n\nNow send the package you want to apply\n"
"to the device with \"adb sideload <filename>\"...\n");
- pid_t child;
- if ((child = fork()) == 0) {
- execl("/system/bin/recovery", "recovery", "--adbd", nullptr);
- _exit(EXIT_FAILURE);
- }
+ int install_result = INSTALL_ERROR;
+ std::map<MinadbdCommands, CommandFunction> command_map{
+ { MinadbdCommands::kInstall,
+ std::bind(&AdbInstallPackageHandler, wipe_cache, ui, &install_result) },
+ };
- if (!SetUsbConfig("sideload")) {
- LOG(ERROR) << "Failed to set usb config to sideload";
- return INSTALL_ERROR;
- }
-
- // How long (in seconds) we wait for the host to start sending us a package, before timing out.
- static constexpr int ADB_INSTALL_TIMEOUT = 300;
-
- // FUSE_SIDELOAD_HOST_PATHNAME will start to exist once the host connects and starts serving a
- // package. Poll for its appearance. (Note that inotify doesn't work with FUSE.)
- int result = INSTALL_ERROR;
- int status;
- bool waited = false;
- for (int i = 0; i < ADB_INSTALL_TIMEOUT; ++i) {
- if (waitpid(child, &status, WNOHANG) != 0) {
- result = INSTALL_ERROR;
- waited = true;
- break;
- }
-
- struct stat st;
- if (stat(FUSE_SIDELOAD_HOST_PATHNAME, &st) != 0) {
- if (errno == ENOENT && i < ADB_INSTALL_TIMEOUT - 1) {
- sleep(1);
- continue;
- } else {
- ui->Print("\nTimed out waiting for package.\n\n");
- result = INSTALL_ERROR;
- kill(child, SIGKILL);
- break;
- }
- }
- result = install_package(FUSE_SIDELOAD_HOST_PATHNAME, wipe_cache, false, 0, ui);
- break;
- }
-
- if (!waited) {
- // Calling stat() on this magic filename signals the minadbd subprocess to shut down.
- struct stat st;
- stat(FUSE_SIDELOAD_HOST_EXIT_PATHNAME, &st);
-
- // TODO: there should be a way to cancel waiting for a package (by pushing some button combo on
- // the device). For now you just have to 'adb sideload' a file that's not a valid package, like
- // "/dev/null".
- waitpid(child, &status, 0);
- }
-
- if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
- if (WEXITSTATUS(status) == 3) {
- ui->Print("\nYou need adb 1.0.32 or newer to sideload\nto this device.\n\n");
- } else if (!WIFSIGNALED(status)) {
- ui->Print("\n(adbd status %d)\n", WEXITSTATUS(status));
- }
- }
+ CreateMinadbdServiceAndExecuteCommands(command_map);
// Clean up before switching to the older state, for example setting the state
// to none sets sys/class/android_usb/android0/enable to 0.
@@ -124,5 +313,5 @@
}
}
- return result;
+ return install_result;
}