roots.cpp - android_bootable_recovery - Gitiles

 /*
  * 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 "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"

 static Fstab fstab;

 extern struct selabel_handle* sehandle;

 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) {
   auto it = std::find_if(fstab.begin(), fstab.end(), [&mount_point](const auto& entry) {
     return entry.mount_point == mount_point;
   });
   return it == fstab.end() ? nullptr : &*it;
 }

 // 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::string cmd("/sbin/mkfs.f2fs");
   // clang-format off
   std::vector<std::string> make_f2fs_cmd = {
     cmd,
     "-g", "android",
     v->blk_device,
   };
   // clang-format on
   if (length >= kSectorSize) {
     make_f2fs_cmd.push_back(std::to_string(length / kSectorSize));
   }

   int result = exec_cmd(make_f2fs_cmd);
   if (result == 0 && !directory.empty()) {
     cmd = "/sbin/sload.f2fs";
     // clang-format off
     std::vector<std::string> sload_f2fs_cmd = {
       cmd,
       "-f", directory,
       "-t", volume,
       v->blk_device,
     };
     // clang-format on
     result = exec_cmd(sload_f2fs_cmd);
   }
   if (result != 0) {
     PLOG(ERROR) << "format_volume: Failed " << cmd << " 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();
 }
	/*
	* 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 "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"

	static Fstab fstab;

	extern struct selabel_handle* sehandle;

	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) {
	auto it = std::find_if(fstab.begin(), fstab.end(), [&mount_point](const auto& entry) {
	return entry.mount_point == mount_point;
	});
	return it == fstab.end() ? nullptr : &*it;
	}

	// 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::string cmd("/sbin/mkfs.f2fs");
	// clang-format off
	std::vector<std::string> make_f2fs_cmd = {
	cmd,
	"-g", "android",
	v->blk_device,
	};
	// clang-format on
	if (length >= kSectorSize) {
	make_f2fs_cmd.push_back(std::to_string(length / kSectorSize));
	}

	int result = exec_cmd(make_f2fs_cmd);
	if (result == 0 && !directory.empty()) {
	cmd = "/sbin/sload.f2fs";
	// clang-format off
	std::vector<std::string> sload_f2fs_cmd = {
	cmd,
	"-f", directory,
	"-t", volume,
	v->blk_device,
	};
	// clang-format on
	result = exec_cmd(sload_f2fs_cmd);
	}
	if (result != 0) {
	PLOG(ERROR) << "format_volume: Failed " << cmd << " 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();
	}