1 files changed, 261 insertions, 5 deletions

diff --git a/updater/target_files.cpp b/updater/target_files.cpp
index 53671dd9d..93540b2e5 100644
--- a/updater/target_files.cpp
+++ b/updater/target_files.cpp
@@ -16,11 +16,267 @@
 
 #include "updater/target_files.h"
 
-std::string TargetFiles::GetProperty(const std::string_view /*key*/,
-                                     const std::string_view default_value) const {
-  return std::string(default_value);
+#include <unistd.h>
+
+#include <algorithm>
+#include <filesystem>
+#include <memory>
+
+#include <android-base/logging.h>
+#include <android-base/strings.h>
+#include <sparse/sparse.h>
+
+static bool SimgToImg(int input_fd, int output_fd) {
+  if (lseek64(input_fd, 0, SEEK_SET) == -1) {
+    PLOG(ERROR) << "Failed to lseek64 on the input sparse image";
+    return false;
+  }
+
+  if (lseek64(output_fd, 0, SEEK_SET) == -1) {
+    PLOG(ERROR) << "Failed to lseek64 on the output raw image";
+    return false;
+  }
+
+  std::unique_ptr<sparse_file, decltype(&sparse_file_destroy)> s_file(
+      sparse_file_import(input_fd, true, false), sparse_file_destroy);
+  if (!s_file) {
+    LOG(ERROR) << "Failed to import the sparse image.";
+    return false;
+  }
+
+  if (sparse_file_write(s_file.get(), output_fd, false, false, false) < 0) {
+    PLOG(ERROR) << "Failed to output the raw image file.";
+    return false;
+  }
+
+  return true;
+}
+
+static bool ParsePropertyFile(const std::string_view prop_content,
+                              std::map<std::string, std::string, std::less<>>* props_map) {
+  LOG(INFO) << "Start parsing build property\n";
+  std::vector<std::string> lines = android::base::Split(std::string(prop_content), "\n");
+  for (const auto& line : lines) {
+    if (line.empty() || line[0] == '#') continue;
+    auto pos = line.find('=');
+    if (pos == std::string::npos) continue;
+    std::string key = line.substr(0, pos);
+    std::string value = line.substr(pos + 1);
+    LOG(INFO) << key << ": " << value;
+    props_map->emplace(key, value);
+  }
+
+  return true;
+}
+
+static bool ParseFstab(const std::string_view fstab, std::vector<FstabInfo>* fstab_info_list) {
+  LOG(INFO) << "parsing fstab\n";
+  std::vector<std::string> lines = android::base::Split(std::string(fstab), "\n");
+  for (const auto& line : lines) {
+    if (line.empty() || line[0] == '#') continue;
+
+    // <block_device>  <mount_point>  <fs_type>  <mount_flags>  optional:<fs_mgr_flags>
+    std::vector<std::string> tokens = android::base::Split(line, " ");
+    tokens.erase(std::remove(tokens.begin(), tokens.end(), ""), tokens.end());
+    if (tokens.size() != 4 && tokens.size() != 5) {
+      LOG(ERROR) << "Unexpected token size: " << tokens.size() << std::endl
+                 << "Error parsing fstab line: " << line;
+      return false;
+    }
+
+    const auto& blockdev = tokens[0];
+    const auto& mount_point = tokens[1];
+    const auto& fs_type = tokens[2];
+    if (!android::base::StartsWith(mount_point, "/")) {
+      LOG(WARNING) << "mount point '" << mount_point << "' does not start with '/'";
+      continue;
+    }
+
+    // The simulator only supports ext4 and emmc for now.
+    if (fs_type != "ext4" && fs_type != "emmc") {
+      LOG(WARNING) << "Unsupported fs_type in " << line;
+      continue;
+    }
+
+    fstab_info_list->emplace_back(blockdev, mount_point, fs_type);
+  }
+
+  return true;
 }
 
-std::string TargetFiles::FindBlockDeviceName(const std::string_view name) const {
-  return std::string(name);
+bool TargetFile::EntryExists(const std::string_view name) const {
+  if (extracted_input_) {
+    std::string entry_path = path_ + "/" + std::string(name);
+    if (access(entry_path.c_str(), O_RDONLY) != 0) {
+      PLOG(WARNING) << "Failed to access " << entry_path;
+      return false;
+    }
+    return true;
+  }
+
+  CHECK(handle_);
+  ZipEntry img_entry;
+  return FindEntry(handle_, name, &img_entry) == 0;
+}
+
+bool TargetFile::ReadEntryToString(const std::string_view name, std::string* content) const {
+  if (extracted_input_) {
+    std::string entry_path = path_ + "/" + std::string(name);
+    return android::base::ReadFileToString(entry_path, content);
+  }
+
+  CHECK(handle_);
+  ZipEntry entry;
+  if (auto find_err = FindEntry(handle_, name, &entry); find_err != 0) {
+    LOG(ERROR) << "failed to find " << name << " in the package: " << ErrorCodeString(find_err);
+    return false;
+  }
+
+  content->resize(entry.uncompressed_length);
+  if (auto extract_err = ExtractToMemory(
+          handle_, &entry, reinterpret_cast<uint8_t*>(&content->at(0)), entry.uncompressed_length);
+      extract_err != 0) {
+    LOG(ERROR) << "failed to read " << name << " from package: " << ErrorCodeString(extract_err);
+    return false;
+  }
+
+  return true;
+}
+
+bool TargetFile::ExtractEntryToTempFile(const std::string_view name,
+                                        TemporaryFile* temp_file) const {
+  if (extracted_input_) {
+    std::string entry_path = path_ + "/" + std::string(name);
+    return std::filesystem::copy_file(entry_path, temp_file->path,
+                                      std::filesystem::copy_options::overwrite_existing);
+  }
+
+  CHECK(handle_);
+  ZipEntry entry;
+  if (auto find_err = FindEntry(handle_, name, &entry); find_err != 0) {
+    LOG(ERROR) << "failed to find " << name << " in the package: " << ErrorCodeString(find_err);
+    return false;
+  }
+
+  if (auto status = ExtractEntryToFile(handle_, &entry, temp_file->fd); status != 0) {
+    LOG(ERROR) << "Failed to extract zip entry " << name << " : " << ErrorCodeString(status);
+    return false;
+  }
+  return true;
+}
+
+bool TargetFile::Open() {
+  if (!extracted_input_) {
+    if (auto ret = OpenArchive(path_.c_str(), &handle_); ret != 0) {
+      LOG(ERROR) << "failed to open source target file " << path_ << ": " << ErrorCodeString(ret);
+      return false;
+    }
+  }
+
+  // Parse the misc info.
+  std::string misc_info_content;
+  if (!ReadEntryToString("META/misc_info.txt", &misc_info_content)) {
+    return false;
+  }
+  if (!ParsePropertyFile(misc_info_content, &misc_info_)) {
+    return false;
+  }
+
+  return true;
+}
+
+bool TargetFile::GetBuildProps(std::map<std::string, std::string, std::less<>>* props_map) const {
+  props_map->clear();
+  // Parse the source zip to mock the system props and block devices. We try all the possible
+  // locations for build props.
+  constexpr std::string_view kPropLocations[] = {
+    "SYSTEM/build.prop",
+    "VENDOR/build.prop",
+    "PRODUCT/build.prop",
+    "PRODUCT_SERVICES/build.prop",
+    "SYSTEM/vendor/build.prop",
+    "SYSTEM/product/build.prop",
+    "SYSTEM/product_services/build.prop",
+    "ODM/build.prop",  // legacy
+    "ODM/etc/build.prop",
+    "VENDOR/odm/build.prop",  // legacy
+    "VENDOR/odm/etc/build.prop",
+  };
+  for (const auto& name : kPropLocations) {
+    std::string build_prop_content;
+    if (!ReadEntryToString(name, &build_prop_content)) {
+      continue;
+    }
+    std::map<std::string, std::string, std::less<>> props;
+    if (!ParsePropertyFile(build_prop_content, &props)) {
+      LOG(ERROR) << "Failed to parse build prop in " << name;
+      return false;
+    }
+    for (const auto& [key, value] : props) {
+      if (auto it = props_map->find(key); it != props_map->end() && it->second != value) {
+        LOG(WARNING) << "Property " << key << " has different values in property files, we got "
+                     << it->second << " and " << value;
+      }
+      props_map->emplace(key, value);
+    }
+  }
+
+  return true;
+}
+
+bool TargetFile::ExtractImage(const std::string_view entry_name, const FstabInfo& fstab_info,
+                              const std::string_view work_dir, TemporaryFile* image_file) const {
+  if (!EntryExists(entry_name)) {
+    return false;
+  }
+
+  // We don't need extra work for 'emmc'; use the image file as the block device.
+  if (fstab_info.fs_type == "emmc" || misc_info_.find("extfs_sparse_flag") == misc_info_.end()) {
+    if (!ExtractEntryToTempFile(entry_name, image_file)) {
+      return false;
+    }
+  } else {  // treated as ext4 sparse image
+    TemporaryFile sparse_image{ std::string(work_dir) };
+    if (!ExtractEntryToTempFile(entry_name, &sparse_image)) {
+      return false;
+    }
+
+    // Convert the sparse image to raw.
+    if (!SimgToImg(sparse_image.fd, image_file->fd)) {
+      LOG(ERROR) << "Failed to convert " << fstab_info.mount_point << " to raw.";
+      return false;
+    }
+  }
+
+  return true;
+}
+
+bool TargetFile::ParseFstabInfo(std::vector<FstabInfo>* fstab_info_list) const {
+  // Parse the fstab file and extract the image files. The location of the fstab actually depends
+  // on some flags e.g. "no_recovery", "recovery_as_boot". Here we just try all possibilities.
+  constexpr std::string_view kRecoveryFstabLocations[] = {
+    "RECOVERY/RAMDISK/system/etc/recovery.fstab",
+    "RECOVERY/RAMDISK/etc/recovery.fstab",
+    "BOOT/RAMDISK/system/etc/recovery.fstab",
+    "BOOT/RAMDISK/etc/recovery.fstab",
+  };
+  std::string fstab_content;
+  for (const auto& name : kRecoveryFstabLocations) {
+    if (std::string content; ReadEntryToString(name, &content)) {
+      fstab_content = std::move(content);
+      break;
+    }
+  }
+  if (fstab_content.empty()) {
+    LOG(ERROR) << "Failed to parse the recovery fstab file";
+    return false;
+  }
+
+  // Extract the images and convert them to raw.
+  if (!ParseFstab(fstab_content, fstab_info_list)) {
+    LOG(ERROR) << "Failed to mount the block devices for source build.";
+    return false;
+  }
+
+  return true;
 }