5 files changed, 486 insertions, 71 deletions

diff --git a/otautil/Android.bp b/otautil/Android.bp
index 41018dd2f..b4936c08b 100644
--- a/otautil/Android.bp
+++ b/otautil/Android.bp
@@ -42,12 +42,23 @@ cc_library_static {
                 "dirutil.cpp",
                 "mounts.cpp",
                 "parse_install_logs.cpp",
+                "roots.cpp",
                 "sysutil.cpp",
                 "thermalutil.cpp",
             ],
 
+            include_dirs: [
+                "system/vold",
+            ],
+
+            static_libs: [
+                "libfstab",
+            ],
+
             shared_libs: [
                 "libcutils",
+                "libext4_utils",
+                "libfs_mgr",
                 "libselinux",
             ],
         },
diff --git a/otautil/include/otautil/roots.h b/otautil/include/otautil/roots.h
new file mode 100644
index 000000000..482f3d050
--- /dev/null
+++ b/otautil/include/otautil/roots.h
@@ -0,0 +1,59 @@
+/*
+ * Copyright (C) 2007 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.
+ */
+
+#pragma once
+
+#include <string>
+
+#include <fstab/fstab.h>
+
+using Volume = android::fs_mgr::FstabEntry;
+
+// Load and parse volume data from /etc/recovery.fstab.
+void load_volume_table();
+
+// Return the Volume* record for this mount point (or nullptr).
+Volume* volume_for_mount_point(const std::string& mount_point);
+
+// Make sure that the volume 'path' is on is mounted.  Returns 0 on
+// success (volume is mounted).
+int ensure_path_mounted(const std::string& path);
+
+// Similar to ensure_path_mounted, but allows one to specify the mount_point.
+int ensure_path_mounted_at(const std::string& path, const std::string& mount_point);
+
+// Make sure that the volume 'path' is on is unmounted.  Returns 0 on
+// success (volume is unmounted);
+int ensure_path_unmounted(const std::string& path);
+
+// Reformat the given volume (must be the mount point only, eg
+// "/cache"), no paths permitted.  Attempts to unmount the volume if
+// it is mounted.
+int format_volume(const std::string& volume);
+
+// Reformat the given volume (must be the mount point only, eg
+// "/cache"), no paths permitted.  Attempts to unmount the volume if
+// it is mounted.
+// Copies 'directory' to root of the newly formatted volume
+int format_volume(const std::string& volume, const std::string& directory);
+
+// Ensure that all and only the volumes that packages expect to find
+// mounted (/tmp and /cache) are mounted.  Returns 0 on success.
+int setup_install_mounts();
+
+bool logical_partitions_mapped();
+
+std::string get_system_root();
diff --git a/otautil/include/otautil/sysutil.h b/otautil/include/otautil/sysutil.h
index 2eeb7c302..692a99e9d 100644
--- a/otautil/include/otautil/sysutil.h
+++ b/otautil/include/otautil/sysutil.h
@@ -22,6 +22,57 @@
 #include <string>
 #include <vector>
 
+#include "rangeset.h"
+
+// This class holds the content of a block map file.
+class BlockMapData {
+ public:
+  // A "block map" which looks like this (from uncrypt/uncrypt.cpp):
+  //
+  //   /dev/block/platform/msm_sdcc.1/by-name/userdata     # block device
+  //   49652 4096                                          # file size in bytes, block size
+  //   3                                                   # count of block ranges
+  //   1000 1008                                           # block range 0
+  //   2100 2102                                           # ... block range 1
+  //   30 33                                               # ... block range 2
+  //
+  // Each block range represents a half-open interval; the line "30 33" reprents the blocks
+  // [30, 31, 32].
+  static BlockMapData ParseBlockMapFile(const std::string& block_map_path);
+
+  explicit operator bool() const {
+    return !path_.empty();
+  }
+
+  std::string path() const {
+    return path_;
+  }
+  uint64_t file_size() const {
+    return file_size_;
+  }
+  uint32_t block_size() const {
+    return block_size_;
+  }
+  RangeSet block_ranges() const {
+    return block_ranges_;
+  }
+
+ private:
+  BlockMapData() = default;
+
+  BlockMapData(const std::string& path, uint64_t file_size, uint32_t block_size,
+               RangeSet block_ranges)
+      : path_(path),
+        file_size_(file_size),
+        block_size_(block_size),
+        block_ranges_(std::move(block_ranges)) {}
+
+  std::string path_;
+  uint64_t file_size_ = 0;
+  uint32_t block_size_ = 0;
+  RangeSet block_ranges_;
+};
+
 /*
  * Use this to keep track of mapped segments.
  */
diff --git a/otautil/roots.cpp b/otautil/roots.cpp
new file mode 100644
index 000000000..815d644e5
--- /dev/null
+++ b/otautil/roots.cpp
@@ -0,0 +1,285 @@
+/*
+ * Copyright (C) 2007 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 "otautil/roots.h"
+
+#include <ctype.h>
+#include <fcntl.h>
+#include <inttypes.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mount.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+#include <iostream>
+#include <string>
+#include <vector>
+
+#include <android-base/logging.h>
+#include <android-base/properties.h>
+#include <android-base/stringprintf.h>
+#include <android-base/unique_fd.h>
+#include <cryptfs.h>
+#include <ext4_utils/wipe.h>
+#include <fs_mgr.h>
+#include <fs_mgr/roots.h>
+#include <fs_mgr_dm_linear.h>
+
+#include "otautil/mounts.h"
+#include "otautil/sysutil.h"
+
+using android::fs_mgr::Fstab;
+using android::fs_mgr::FstabEntry;
+using android::fs_mgr::ReadDefaultFstab;
+
+static Fstab fstab;
+
+void load_volume_table() {
+  if (!ReadDefaultFstab(&fstab)) {
+    LOG(ERROR) << "Failed to read default fstab";
+    return;
+  }
+
+  fstab.emplace_back(FstabEntry{
+      .mount_point = "/tmp", .fs_type = "ramdisk", .blk_device = "ramdisk", .length = 0 });
+
+  std::cout << "recovery filesystem table" << std::endl << "=========================" << std::endl;
+  for (size_t i = 0; i < fstab.size(); ++i) {
+    const auto& entry = fstab[i];
+    std::cout << "  " << i << " " << entry.mount_point << " "
+              << " " << entry.fs_type << " " << entry.blk_device << " " << entry.length
+              << std::endl;
+  }
+  std::cout << std::endl;
+}
+
+Volume* volume_for_mount_point(const std::string& mount_point) {
+  return android::fs_mgr::GetEntryForMountPoint(&fstab, mount_point);
+}
+
+// Mount the volume specified by path at the given mount_point.
+int ensure_path_mounted_at(const std::string& path, const std::string& mount_point) {
+  return android::fs_mgr::EnsurePathMounted(&fstab, path, mount_point) ? 0 : -1;
+}
+
+int ensure_path_mounted(const std::string& path) {
+  // Mount at the default mount point.
+  return android::fs_mgr::EnsurePathMounted(&fstab, path) ? 0 : -1;
+}
+
+int ensure_path_unmounted(const std::string& path) {
+  return android::fs_mgr::EnsurePathUnmounted(&fstab, path) ? 0 : -1;
+}
+
+static int exec_cmd(const std::vector<std::string>& args) {
+  CHECK(!args.empty());
+  auto argv = StringVectorToNullTerminatedArray(args);
+
+  pid_t child;
+  if ((child = fork()) == 0) {
+    execv(argv[0], argv.data());
+    _exit(EXIT_FAILURE);
+  }
+
+  int status;
+  waitpid(child, &status, 0);
+  if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
+    LOG(ERROR) << args[0] << " failed with status " << WEXITSTATUS(status);
+  }
+  return WEXITSTATUS(status);
+}
+
+static int64_t get_file_size(int fd, uint64_t reserve_len) {
+  struct stat buf;
+  int ret = fstat(fd, &buf);
+  if (ret) return 0;
+
+  int64_t computed_size;
+  if (S_ISREG(buf.st_mode)) {
+    computed_size = buf.st_size - reserve_len;
+  } else if (S_ISBLK(buf.st_mode)) {
+    uint64_t block_device_size = get_block_device_size(fd);
+    if (block_device_size < reserve_len ||
+        block_device_size > std::numeric_limits<int64_t>::max()) {
+      computed_size = 0;
+    } else {
+      computed_size = block_device_size - reserve_len;
+    }
+  } else {
+    computed_size = 0;
+  }
+
+  return computed_size;
+}
+
+int format_volume(const std::string& volume, const std::string& directory) {
+  const FstabEntry* v = android::fs_mgr::GetEntryForPath(&fstab, volume);
+  if (v == nullptr) {
+    LOG(ERROR) << "unknown volume \"" << volume << "\"";
+    return -1;
+  }
+  if (v->fs_type == "ramdisk") {
+    LOG(ERROR) << "can't format_volume \"" << volume << "\"";
+    return -1;
+  }
+  if (v->mount_point != volume) {
+    LOG(ERROR) << "can't give path \"" << volume << "\" to format_volume";
+    return -1;
+  }
+  if (ensure_path_unmounted(volume) != 0) {
+    LOG(ERROR) << "format_volume: Failed to unmount \"" << v->mount_point << "\"";
+    return -1;
+  }
+  if (v->fs_type != "ext4" && v->fs_type != "f2fs") {
+    LOG(ERROR) << "format_volume: fs_type \"" << v->fs_type << "\" unsupported";
+    return -1;
+  }
+
+  // If there's a key_loc that looks like a path, it should be a block device for storing encryption
+  // metadata. Wipe it too.
+  if (!v->key_loc.empty() && v->key_loc[0] == '/') {
+    LOG(INFO) << "Wiping " << v->key_loc;
+    int fd = open(v->key_loc.c_str(), O_WRONLY | O_CREAT, 0644);
+    if (fd == -1) {
+      PLOG(ERROR) << "format_volume: Failed to open " << v->key_loc;
+      return -1;
+    }
+    wipe_block_device(fd, get_file_size(fd));
+    close(fd);
+  }
+
+  int64_t length = 0;
+  if (v->length > 0) {
+    length = v->length;
+  } else if (v->length < 0 || v->key_loc == "footer") {
+    android::base::unique_fd fd(open(v->blk_device.c_str(), O_RDONLY));
+    if (fd == -1) {
+      PLOG(ERROR) << "format_volume: failed to open " << v->blk_device;
+      return -1;
+    }
+    length = get_file_size(fd.get(), v->length ? -v->length : CRYPT_FOOTER_OFFSET);
+    if (length <= 0) {
+      LOG(ERROR) << "get_file_size: invalid size " << length << " for " << v->blk_device;
+      return -1;
+    }
+  }
+
+  if (v->fs_type == "ext4") {
+    static constexpr int kBlockSize = 4096;
+    std::vector<std::string> mke2fs_args = {
+      "/system/bin/mke2fs", "-F", "-t", "ext4", "-b", std::to_string(kBlockSize),
+    };
+
+    int raid_stride = v->logical_blk_size / kBlockSize;
+    int raid_stripe_width = v->erase_blk_size / kBlockSize;
+    // stride should be the max of 8KB and logical block size
+    if (v->logical_blk_size != 0 && v->logical_blk_size < 8192) {
+      raid_stride = 8192 / kBlockSize;
+    }
+    if (v->erase_blk_size != 0 && v->logical_blk_size != 0) {
+      mke2fs_args.push_back("-E");
+      mke2fs_args.push_back(
+          android::base::StringPrintf("stride=%d,stripe-width=%d", raid_stride, raid_stripe_width));
+    }
+    mke2fs_args.push_back(v->blk_device);
+    if (length != 0) {
+      mke2fs_args.push_back(std::to_string(length / kBlockSize));
+    }
+
+    int result = exec_cmd(mke2fs_args);
+    if (result == 0 && !directory.empty()) {
+      std::vector<std::string> e2fsdroid_args = {
+        "/system/bin/e2fsdroid", "-e", "-f", directory, "-a", volume, v->blk_device,
+      };
+      result = exec_cmd(e2fsdroid_args);
+    }
+
+    if (result != 0) {
+      PLOG(ERROR) << "format_volume: Failed to make ext4 on " << v->blk_device;
+      return -1;
+    }
+    return 0;
+  }
+
+  // Has to be f2fs because we checked earlier.
+  static constexpr int kSectorSize = 4096;
+  std::vector<std::string> make_f2fs_cmd = {
+    "/system/bin/make_f2fs",
+    "-g",
+    "android",
+    v->blk_device,
+  };
+  if (length >= kSectorSize) {
+    make_f2fs_cmd.push_back(std::to_string(length / kSectorSize));
+  }
+
+  if (exec_cmd(make_f2fs_cmd) != 0) {
+    PLOG(ERROR) << "format_volume: Failed to make_f2fs on " << v->blk_device;
+    return -1;
+  }
+  if (!directory.empty()) {
+    std::vector<std::string> sload_f2fs_cmd = {
+      "/system/bin/sload_f2fs", "-f", directory, "-t", volume, v->blk_device,
+    };
+    if (exec_cmd(sload_f2fs_cmd) != 0) {
+      PLOG(ERROR) << "format_volume: Failed to sload_f2fs on " << v->blk_device;
+      return -1;
+    }
+  }
+  return 0;
+}
+
+int format_volume(const std::string& volume) {
+  return format_volume(volume, "");
+}
+
+int setup_install_mounts() {
+  if (fstab.empty()) {
+    LOG(ERROR) << "can't set up install mounts: no fstab loaded";
+    return -1;
+  }
+  for (const FstabEntry& entry : fstab) {
+    // We don't want to do anything with "/".
+    if (entry.mount_point == "/") {
+      continue;
+    }
+
+    if (entry.mount_point == "/tmp" || entry.mount_point == "/cache") {
+      if (ensure_path_mounted(entry.mount_point) != 0) {
+        LOG(ERROR) << "Failed to mount " << entry.mount_point;
+        return -1;
+      }
+    } else {
+      if (ensure_path_unmounted(entry.mount_point) != 0) {
+        LOG(ERROR) << "Failed to unmount " << entry.mount_point;
+        return -1;
+      }
+    }
+  }
+  return 0;
+}
+
+bool logical_partitions_mapped() {
+  return android::fs_mgr::LogicalPartitionsMapped();
+}
+
+std::string get_system_root() {
+  return android::fs_mgr::GetSystemRoot();
+}
diff --git a/otautil/sysutil.cpp b/otautil/sysutil.cpp
index d8969a0bb..8366fa0ac 100644
--- a/otautil/sysutil.cpp
+++ b/otautil/sysutil.cpp
@@ -18,12 +18,13 @@
 
 #include <errno.h>  // TEMP_FAILURE_RETRY
 #include <fcntl.h>
-#include <stdint.h>  // SIZE_MAX
+#include <inttypes.h>
 #include <sys/mman.h>
 #include <sys/stat.h>
 #include <sys/types.h>
 
 #include <algorithm>
+#include <limits>
 #include <string>
 #include <vector>
 
@@ -34,6 +35,68 @@
 #include <android-base/unique_fd.h>
 #include <cutils/android_reboot.h>
 
+BlockMapData BlockMapData::ParseBlockMapFile(const std::string& block_map_path) {
+  std::string content;
+  if (!android::base::ReadFileToString(block_map_path, &content)) {
+    LOG(ERROR) << "Failed to read " << block_map_path;
+    return {};
+  }
+
+  std::vector<std::string> lines = android::base::Split(android::base::Trim(content), "\n");
+  if (lines.size() < 4) {
+    LOG(ERROR) << "Block map file is too short: " << lines.size();
+    return {};
+  }
+
+  const std::string& block_dev = lines[0];
+
+  uint64_t file_size;
+  uint32_t blksize;
+  if (sscanf(lines[1].c_str(), "%" SCNu64 "%" SCNu32, &file_size, &blksize) != 2) {
+    LOG(ERROR) << "Failed to parse file size and block size: " << lines[1];
+    return {};
+  }
+
+  if (file_size == 0 || blksize == 0) {
+    LOG(ERROR) << "Invalid size in block map file: size " << file_size << ", blksize " << blksize;
+    return {};
+  }
+
+  size_t range_count;
+  if (sscanf(lines[2].c_str(), "%zu", &range_count) != 1) {
+    LOG(ERROR) << "Failed to parse block map header: " << lines[2];
+    return {};
+  }
+
+  uint64_t blocks = ((file_size - 1) / blksize) + 1;
+  if (blocks > std::numeric_limits<uint32_t>::max() || range_count == 0 ||
+      lines.size() != 3 + range_count) {
+    LOG(ERROR) << "Invalid data in block map file: size " << file_size << ", blksize " << blksize
+               << ", range_count " << range_count << ", lines " << lines.size();
+    return {};
+  }
+
+  RangeSet ranges;
+  uint64_t remaining_blocks = blocks;
+  for (size_t i = 0; i < range_count; ++i) {
+    const std::string& line = lines[i + 3];
+    uint64_t start, end;
+    if (sscanf(line.c_str(), "%" SCNu64 "%" SCNu64, &start, &end) != 2) {
+      LOG(ERROR) << "failed to parse range " << i << ": " << line;
+      return {};
+    }
+    uint64_t range_blocks = end - start;
+    if (end <= start || range_blocks > remaining_blocks) {
+      LOG(ERROR) << "Invalid range: " << start << " " << end;
+      return {};
+    }
+    ranges.PushBack({ start, end });
+    remaining_blocks -= range_blocks;
+  }
+
+  return BlockMapData(block_dev, file_size, blksize, std::move(ranges));
+}
+
 bool MemMapping::MapFD(int fd) {
   struct stat sb;
   if (fstat(fd, &sb) == -1) {
@@ -55,115 +118,61 @@ bool MemMapping::MapFD(int fd) {
   return true;
 }
 
-// A "block map" which looks like this (from uncrypt/uncrypt.cpp):
-//
-//   /dev/block/platform/msm_sdcc.1/by-name/userdata     # block device
-//   49652 4096                                          # file size in bytes, block size
-//   3                                                   # count of block ranges
-//   1000 1008                                           # block range 0
-//   2100 2102                                           # ... block range 1
-//   30 33                                               # ... block range 2
-//
-// Each block range represents a half-open interval; the line "30 33" reprents the blocks
-// [30, 31, 32].
 bool MemMapping::MapBlockFile(const std::string& filename) {
-  std::string content;
-  if (!android::base::ReadFileToString(filename, &content)) {
-    PLOG(ERROR) << "Failed to read " << filename;
-    return false;
-  }
-
-  std::vector<std::string> lines = android::base::Split(android::base::Trim(content), "\n");
-  if (lines.size() < 4) {
-    LOG(ERROR) << "Block map file is too short: " << lines.size();
-    return false;
-  }
-
-  size_t size;
-  size_t blksize;
-  if (sscanf(lines[1].c_str(), "%zu %zu", &size, &blksize) != 2) {
-    LOG(ERROR) << "Failed to parse file size and block size: " << lines[1];
-    return false;
-  }
-
-  size_t range_count;
-  if (sscanf(lines[2].c_str(), "%zu", &range_count) != 1) {
-    LOG(ERROR) << "Failed to parse block map header: " << lines[2];
+  auto block_map_data = BlockMapData::ParseBlockMapFile(filename);
+  if (!block_map_data) {
     return false;
   }
 
-  size_t blocks;
-  if (blksize != 0) {
-    blocks = ((size - 1) / blksize) + 1;
-  }
-  if (size == 0 || blksize == 0 || blocks > SIZE_MAX / blksize || range_count == 0 ||
-      lines.size() != 3 + range_count) {
-    LOG(ERROR) << "Invalid data in block map file: size " << size << ", blksize " << blksize
-               << ", range_count " << range_count << ", lines " << lines.size();
+  if (block_map_data.file_size() > std::numeric_limits<size_t>::max()) {
+    LOG(ERROR) << "File size is too large for mmap " << block_map_data.file_size();
     return false;
   }
 
   // Reserve enough contiguous address space for the whole file.
+  uint32_t blksize = block_map_data.block_size();
+  uint64_t blocks = ((block_map_data.file_size() - 1) / blksize) + 1;
   void* reserve = mmap(nullptr, blocks * blksize, PROT_NONE, MAP_PRIVATE | MAP_ANON, -1, 0);
   if (reserve == MAP_FAILED) {
     PLOG(ERROR) << "failed to reserve address space";
     return false;
   }
 
-  const std::string& block_dev = lines[0];
-  android::base::unique_fd fd(TEMP_FAILURE_RETRY(open(block_dev.c_str(), O_RDONLY)));
+  android::base::unique_fd fd(TEMP_FAILURE_RETRY(open(block_map_data.path().c_str(), O_RDONLY)));
   if (fd == -1) {
-    PLOG(ERROR) << "failed to open block device " << block_dev;
+    PLOG(ERROR) << "failed to open block device " << block_map_data.path();
     munmap(reserve, blocks * blksize);
     return false;
   }
 
   ranges_.clear();
 
-  unsigned char* next = static_cast<unsigned char*>(reserve);
+  auto next = static_cast<unsigned char*>(reserve);
   size_t remaining_size = blocks * blksize;
-  bool success = true;
-  for (size_t i = 0; i < range_count; ++i) {
-    const std::string& line = lines[i + 3];
-
-    size_t start, end;
-    if (sscanf(line.c_str(), "%zu %zu\n", &start, &end) != 2) {
-      LOG(ERROR) << "failed to parse range " << i << ": " << line;
-      success = false;
-      break;
-    }
+  for (const auto& [start, end] : block_map_data.block_ranges()) {
     size_t range_size = (end - start) * blksize;
-    if (end <= start || (end - start) > SIZE_MAX / blksize || range_size > remaining_size) {
-      LOG(ERROR) << "Invalid range: " << start << " " << end;
-      success = false;
-      break;
-    }
-
     void* range_start = mmap(next, range_size, PROT_READ, MAP_PRIVATE | MAP_FIXED, fd,
                              static_cast<off_t>(start) * blksize);
     if (range_start == MAP_FAILED) {
-      PLOG(ERROR) << "failed to map range " << i << ": " << line;
-      success = false;
-      break;
+      PLOG(ERROR) << "failed to map range " << start << ": " << end;
+      munmap(reserve, blocks * blksize);
+      return false;
     }
     ranges_.emplace_back(MappedRange{ range_start, range_size });
 
     next += range_size;
     remaining_size -= range_size;
   }
-  if (success && remaining_size != 0) {
+  if (remaining_size != 0) {
     LOG(ERROR) << "Invalid ranges: remaining_size " << remaining_size;
-    success = false;
-  }
-  if (!success) {
     munmap(reserve, blocks * blksize);
     return false;
   }
 
   addr = static_cast<unsigned char*>(reserve);
-  length = size;
+  length = block_map_data.file_size();
 
-  LOG(INFO) << "mmapped " << range_count << " ranges";
+  LOG(INFO) << "mmapped " << block_map_data.block_ranges().size() << " ranges";
 
   return true;
 }