1 files changed, 231 insertions, 0 deletions

diff --git a/install/fuse_install.cpp b/install/fuse_install.cpp
new file mode 100644
index 000000000..ffde4a348
--- /dev/null
+++ b/install/fuse_install.cpp
@@ -0,0 +1,231 @@
+/*
+ * 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 "install/fuse_install.h"
+
+#include <dirent.h>
+#include <signal.h>
+#include <sys/mount.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+#include <algorithm>
+#include <functional>
+#include <memory>
+#include <string>
+#include <vector>
+
+#include <android-base/logging.h>
+#include <android-base/strings.h>
+
+#include "bootloader_message/bootloader_message.h"
+#include "fuse_provider.h"
+#include "fuse_sideload.h"
+#include "install/install.h"
+#include "otautil/roots.h"
+
+static constexpr const char* SDCARD_ROOT = "/sdcard";
+// How long (in seconds) we wait for the fuse-provided package file to
+// appear, before timing out.
+static constexpr int SDCARD_INSTALL_TIMEOUT = 10;
+
+// Set the BCB to reboot back into recovery (it won't resume the install from
+// sdcard though).
+static void SetSdcardUpdateBootloaderMessage() {
+  std::vector<std::string> options;
+  std::string err;
+  if (!update_bootloader_message(options, &err)) {
+    LOG(ERROR) << "Failed to set BCB message: " << err;
+  }
+}
+
+// Returns the selected filename, or an empty string.
+static std::string BrowseDirectory(const std::string& path, Device* device, RecoveryUI* ui) {
+  ensure_path_mounted(path);
+
+  std::unique_ptr<DIR, decltype(&closedir)> d(opendir(path.c_str()), closedir);
+  if (!d) {
+    PLOG(ERROR) << "error opening " << path;
+    return "";
+  }
+
+  std::vector<std::string> dirs;
+  std::vector<std::string> entries{ "../" };  // "../" is always the first entry.
+
+  dirent* de;
+  while ((de = readdir(d.get())) != nullptr) {
+    std::string name(de->d_name);
+
+    if (de->d_type == DT_DIR) {
+      // Skip "." and ".." entries.
+      if (name == "." || name == "..") continue;
+      dirs.push_back(name + "/");
+    } else if (de->d_type == DT_REG && (android::base::EndsWithIgnoreCase(name, ".zip") ||
+                                        android::base::EndsWithIgnoreCase(name, ".map"))) {
+      entries.push_back(name);
+    }
+  }
+
+  std::sort(dirs.begin(), dirs.end());
+  std::sort(entries.begin(), entries.end());
+
+  // Append dirs to the entries list.
+  entries.insert(entries.end(), dirs.begin(), dirs.end());
+
+  std::vector<std::string> headers{ "Choose a package to install:", path };
+
+  size_t chosen_item = 0;
+  while (true) {
+    chosen_item = ui->ShowMenu(
+        headers, entries, chosen_item, true,
+        std::bind(&Device::HandleMenuKey, device, std::placeholders::_1, std::placeholders::_2));
+
+    // Return if WaitKey() was interrupted.
+    if (chosen_item == static_cast<size_t>(RecoveryUI::KeyError::INTERRUPTED)) {
+      return "";
+    }
+
+    const std::string& item = entries[chosen_item];
+    if (chosen_item == 0) {
+      // Go up but continue browsing (if the caller is BrowseDirectory).
+      return "";
+    }
+
+    std::string new_path = path + "/" + item;
+    if (new_path.back() == '/') {
+      // Recurse down into a subdirectory.
+      new_path.pop_back();
+      std::string result = BrowseDirectory(new_path, device, ui);
+      if (!result.empty()) return result;
+    } else {
+      // Selected a zip file: return the path to the caller.
+      return new_path;
+    }
+  }
+
+  // Unreachable.
+}
+
+static bool StartInstallPackageFuse(std::string_view path) {
+  if (path.empty()) {
+    return false;
+  }
+
+  constexpr auto FUSE_BLOCK_SIZE = 65536;
+  bool is_block_map = android::base::ConsumePrefix(&path, "@");
+  auto file_data_reader =
+      is_block_map ? FuseBlockDataProvider::CreateFromBlockMap(std::string(path), FUSE_BLOCK_SIZE)
+                   : FuseFileDataProvider::CreateFromFile(std::string(path), FUSE_BLOCK_SIZE);
+
+  if (!file_data_reader->Valid()) {
+    return false;
+  }
+
+  if (android::base::StartsWith(path, SDCARD_ROOT)) {
+    // The installation process expects to find the sdcard unmounted. Unmount it with MNT_DETACH so
+    // that our open file continues to work but new references see it as unmounted.
+    umount2(SDCARD_ROOT, MNT_DETACH);
+  }
+
+  return run_fuse_sideload(std::move(file_data_reader)) == 0;
+}
+
+InstallResult InstallWithFuseFromPath(std::string_view path, RecoveryUI* ui) {
+  // We used to use fuse in a thread as opposed to a process. Since accessing
+  // through fuse involves going from kernel to userspace to kernel, it leads
+  // to deadlock when a page fault occurs. (Bug: 26313124)
+  pid_t child;
+  if ((child = fork()) == 0) {
+    bool status = StartInstallPackageFuse(path);
+
+    _exit(status ? EXIT_SUCCESS : EXIT_FAILURE);
+  }
+
+  // FUSE_SIDELOAD_HOST_PATHNAME will start to exist once the fuse in child process is ready.
+  InstallResult result = INSTALL_ERROR;
+  int status;
+  bool waited = false;
+  for (int i = 0; i < SDCARD_INSTALL_TIMEOUT; ++i) {
+    if (waitpid(child, &status, WNOHANG) == -1) {
+      result = INSTALL_ERROR;
+      waited = true;
+      break;
+    }
+
+    struct stat sb;
+    if (stat(FUSE_SIDELOAD_HOST_PATHNAME, &sb) == -1) {
+      if (errno == ENOENT && i < SDCARD_INSTALL_TIMEOUT - 1) {
+        sleep(1);
+        continue;
+      } else {
+        LOG(ERROR) << "Timed out waiting for the fuse-provided package.";
+        result = INSTALL_ERROR;
+        kill(child, SIGKILL);
+        break;
+      }
+    }
+    auto package =
+        Package::CreateFilePackage(FUSE_SIDELOAD_HOST_PATHNAME,
+                                   std::bind(&RecoveryUI::SetProgress, ui, std::placeholders::_1));
+    result =
+        InstallPackage(package.get(), FUSE_SIDELOAD_HOST_PATHNAME, false, 0 /* retry_count */, ui);
+    break;
+  }
+
+  if (!waited) {
+    // Calling stat() on this magic filename signals the fuse
+    // filesystem to shut down.
+    struct stat sb;
+    stat(FUSE_SIDELOAD_HOST_EXIT_PATHNAME, &sb);
+
+    waitpid(child, &status, 0);
+  }
+
+  if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
+    LOG(ERROR) << "Error exit from the fuse process: " << WEXITSTATUS(status);
+  }
+
+  return result;
+}
+
+InstallResult ApplyFromSdcard(Device* device) {
+  auto ui = device->GetUI();
+  if (ensure_path_mounted(SDCARD_ROOT) != 0) {
+    LOG(ERROR) << "\n-- Couldn't mount " << SDCARD_ROOT << ".\n";
+    return INSTALL_ERROR;
+  }
+
+  std::string path = BrowseDirectory(SDCARD_ROOT, device, ui);
+  if (path.empty()) {
+    LOG(ERROR) << "\n-- No package file selected.\n";
+    ensure_path_unmounted(SDCARD_ROOT);
+    return INSTALL_ERROR;
+  }
+
+  // Hint the install function to read from a block map file.
+  if (android::base::EndsWithIgnoreCase(path, ".map")) {
+    path = "@" + path;
+  }
+
+  ui->Print("\n-- Install %s ...\n", path.c_str());
+  SetSdcardUpdateBootloaderMessage();
+
+  auto result = InstallWithFuseFromPath(path, ui);
+  ensure_path_unmounted(SDCARD_ROOT);
+  return result;
+}