1 files changed, 190 insertions, 0 deletions

diff --git a/install/wipe_data.cpp b/install/wipe_data.cpp
new file mode 100644
index 000000000..7db79048a
--- /dev/null
+++ b/install/wipe_data.cpp
@@ -0,0 +1,190 @@
+/*
+ * 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/wipe_data.h"
+
+#include <dirent.h>
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/stat.h>
+
+#include <functional>
+#include <memory>
+#include <vector>
+
+#include <android-base/file.h>
+#include <android-base/logging.h>
+#include <android-base/stringprintf.h>
+
+#include "otautil/dirutil.h"
+#include "otautil/logging.h"
+#include "otautil/roots.h"
+#include "recovery_ui/ui.h"
+
+constexpr const char* CACHE_ROOT = "/cache";
+constexpr const char* DATA_ROOT = "/data";
+constexpr const char* METADATA_ROOT = "/metadata";
+
+constexpr const char* CACHE_LOG_DIR = "/cache/recovery";
+
+static struct selabel_handle* sehandle;
+
+void SetWipeDataSehandle(selabel_handle* handle) {
+  sehandle = handle;
+}
+
+struct saved_log_file {
+  std::string name;
+  struct stat sb;
+  std::string data;
+};
+
+static bool EraseVolume(const char* volume, RecoveryUI* ui, bool convert_fbe) {
+  bool is_cache = (strcmp(volume, CACHE_ROOT) == 0);
+  bool is_data = (strcmp(volume, DATA_ROOT) == 0);
+
+  ui->SetBackground(RecoveryUI::ERASING);
+  ui->SetProgressType(RecoveryUI::INDETERMINATE);
+
+  std::vector<saved_log_file> log_files;
+
+  if (is_cache) {
+    // If we're reformatting /cache, we load any past logs
+    // (i.e. "/cache/recovery/last_*") and the current log
+    // ("/cache/recovery/log") into memory, so we can restore them after
+    // the reformat.
+
+    ensure_path_mounted(volume);
+
+    struct dirent* de;
+    std::unique_ptr<DIR, decltype(&closedir)> d(opendir(CACHE_LOG_DIR), closedir);
+    if (d) {
+      while ((de = readdir(d.get())) != nullptr) {
+        if (strncmp(de->d_name, "last_", 5) == 0 || strcmp(de->d_name, "log") == 0) {
+          std::string path = android::base::StringPrintf("%s/%s", CACHE_LOG_DIR, de->d_name);
+
+          struct stat sb;
+          if (stat(path.c_str(), &sb) == 0) {
+            // truncate files to 512kb
+            if (sb.st_size > (1 << 19)) {
+              sb.st_size = 1 << 19;
+            }
+
+            std::string data(sb.st_size, '\0');
+            FILE* f = fopen(path.c_str(), "rbe");
+            fread(&data[0], 1, data.size(), f);
+            fclose(f);
+
+            log_files.emplace_back(saved_log_file{ path, sb, data });
+          }
+        }
+      }
+    } else {
+      if (errno != ENOENT) {
+        PLOG(ERROR) << "Failed to opendir " << CACHE_LOG_DIR;
+      }
+    }
+  }
+
+  ui->Print("Formatting %s...\n", volume);
+
+  ensure_path_unmounted(volume);
+
+  int result;
+  if (is_data && convert_fbe) {
+    constexpr const char* CONVERT_FBE_DIR = "/tmp/convert_fbe";
+    constexpr const char* CONVERT_FBE_FILE = "/tmp/convert_fbe/convert_fbe";
+    // Create convert_fbe breadcrumb file to signal init to convert to file based encryption, not
+    // full disk encryption.
+    if (mkdir(CONVERT_FBE_DIR, 0700) != 0) {
+      PLOG(ERROR) << "Failed to mkdir " << CONVERT_FBE_DIR;
+      return false;
+    }
+    FILE* f = fopen(CONVERT_FBE_FILE, "wbe");
+    if (!f) {
+      PLOG(ERROR) << "Failed to convert to file encryption";
+      return false;
+    }
+    fclose(f);
+    result = format_volume(volume, CONVERT_FBE_DIR);
+    remove(CONVERT_FBE_FILE);
+    rmdir(CONVERT_FBE_DIR);
+  } else {
+    result = format_volume(volume);
+  }
+
+  if (is_cache) {
+    // Re-create the log dir and write back the log entries.
+    if (ensure_path_mounted(CACHE_LOG_DIR) == 0 &&
+        mkdir_recursively(CACHE_LOG_DIR, 0777, false, sehandle) == 0) {
+      for (const auto& log : log_files) {
+        if (!android::base::WriteStringToFile(log.data, log.name, log.sb.st_mode, log.sb.st_uid,
+                                              log.sb.st_gid)) {
+          PLOG(ERROR) << "Failed to write to " << log.name;
+        }
+      }
+    } else {
+      PLOG(ERROR) << "Failed to mount / create " << CACHE_LOG_DIR;
+    }
+
+    // Any part of the log we'd copied to cache is now gone.
+    // Reset the pointer so we copy from the beginning of the temp
+    // log.
+    reset_tmplog_offset();
+    copy_logs(true /* save_current_log */, true /* has_cache */, sehandle);
+  }
+
+  return (result == 0);
+}
+
+bool WipeCache(RecoveryUI* ui, const std::function<bool()>& confirm_func) {
+  bool has_cache = volume_for_mount_point("/cache") != nullptr;
+  if (!has_cache) {
+    ui->Print("No /cache partition found.\n");
+    return false;
+  }
+
+  if (confirm_func && !confirm_func()) {
+    return false;
+  }
+
+  ui->Print("\n-- Wiping cache...\n");
+  bool success = EraseVolume("/cache", ui, false);
+  ui->Print("Cache wipe %s.\n", success ? "complete" : "failed");
+  return success;
+}
+
+bool WipeData(Device* device, bool convert_fbe) {
+  RecoveryUI* ui = device->GetUI();
+  ui->Print("\n-- Wiping data...\n");
+  bool success = device->PreWipeData();
+  if (success) {
+    success &= EraseVolume(DATA_ROOT, ui, convert_fbe);
+    bool has_cache = volume_for_mount_point("/cache") != nullptr;
+    if (has_cache) {
+      success &= EraseVolume(CACHE_ROOT, ui, false);
+    }
+    if (volume_for_mount_point(METADATA_ROOT) != nullptr) {
+      success &= EraseVolume(METADATA_ROOT, ui, false);
+    }
+  }
+  if (success) {
+    success &= device->PostWipeData();
+  }
+  ui->Print("Data wipe %s.\n", success ? "complete" : "failed");
+  return success;
+}
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