roots.cpp - platform/bootable/recovery - Git at Google

 /*
  * 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 <errno.h>
 #include <stdlib.h>
 #include <sys/mount.h>
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <sys/wait.h>
 #include <unistd.h>
 #include <ctype.h>
 #include <fcntl.h>

 #include <android-base/logging.h>
 #include <android-base/properties.h>
 #include <android-base/stringprintf.h>
 #include <android-base/unique_fd.h>
 #include <ext4_utils/wipe.h>
 #include <fs_mgr.h>

 #include "common.h"
 #include "mounts.h"
 #include "cryptfs.h"

 static struct fstab *fstab = NULL;

 extern struct selabel_handle *sehandle;

 void load_volume_table()
 {
     int i;
     int ret;

     fstab = fs_mgr_read_fstab_default();
     if (!fstab) {
         LOG(ERROR) << "failed to read default fstab";
         return;
     }

     ret = fs_mgr_add_entry(fstab, "/tmp", "ramdisk", "ramdisk");
     if (ret < 0 ) {
         LOG(ERROR) << "failed to add /tmp entry to fstab";
         fs_mgr_free_fstab(fstab);
         fstab = NULL;
         return;
     }

     printf("recovery filesystem table\n");
     printf("=========================\n");
     for (i = 0; i < fstab->num_entries; ++i) {
         Volume* v = &fstab->recs[i];
         printf("  %d %s %s %s %lld\n", i, v->mount_point, v->fs_type,
                v->blk_device, v->length);
     }
     printf("\n");
 }

 Volume* volume_for_path(const char* path) {
     return fs_mgr_get_entry_for_mount_point(fstab, path);
 }

 // Mount the volume specified by path at the given mount_point.
 int ensure_path_mounted_at(const char* path, const char* mount_point) {
     Volume* v = volume_for_path(path);
     if (v == NULL) {
         LOG(ERROR) << "unknown volume for path [" << path << "]";
         return -1;
     }
     if (strcmp(v->fs_type, "ramdisk") == 0) {
         // the ramdisk is always mounted.
         return 0;
     }

     if (!scan_mounted_volumes()) {
         LOG(ERROR) << "failed to scan mounted volumes";
         return -1;
     }

     if (!mount_point) {
         mount_point = v->mount_point;
     }

     MountedVolume* mv = find_mounted_volume_by_mount_point(mount_point);
     if (mv) {
         // volume is already mounted
         return 0;
     }

     mkdir(mount_point, 0755);  // in case it doesn't already exist

     if (strcmp(v->fs_type, "ext4") == 0 ||
                strcmp(v->fs_type, "squashfs") == 0 ||
                strcmp(v->fs_type, "vfat") == 0) {
         int result = mount(v->blk_device, mount_point, v->fs_type, v->flags, v->fs_options);
         if (result == -1 && fs_mgr_is_formattable(v)) {
             LOG(ERROR) << "failed to mount " << mount_point << " (" << strerror(errno)
                        << ") , formatting.....";
             bool crypt_footer = fs_mgr_is_encryptable(v) && !strcmp(v->key_loc, "footer");
             if (fs_mgr_do_format(v, crypt_footer) == 0) {
                 result = mount(v->blk_device, mount_point, v->fs_type, v->flags, v->fs_options);
             } else {
                 PLOG(ERROR) << "failed to format " << mount_point;
                 return -1;
             }
         }

         if (result == -1) {
             PLOG(ERROR) << "failed to mount " << mount_point;
             return -1;
         }
         return 0;
     }

     LOG(ERROR) << "unknown fs_type \"" << v->fs_type << "\" for " << mount_point;
     return -1;
 }

 int ensure_path_mounted(const char* path) {
     // Mount at the default mount point.
     return ensure_path_mounted_at(path, nullptr);
 }

 int ensure_path_unmounted(const char* path) {
     Volume* v = volume_for_path(path);
     if (v == NULL) {
         LOG(ERROR) << "unknown volume for path [" << path << "]";
         return -1;
     }
     if (strcmp(v->fs_type, "ramdisk") == 0) {
         // the ramdisk is always mounted; you can't unmount it.
         return -1;
     }

     if (!scan_mounted_volumes()) {
         LOG(ERROR) << "failed to scan mounted volumes";
         return -1;
     }

     MountedVolume* mv = find_mounted_volume_by_mount_point(v->mount_point);
     if (mv == NULL) {
         // volume is already unmounted
         return 0;
     }

     return unmount_mounted_volume(mv);
 }

 static int exec_cmd(const char* path, char* const argv[]) {
     int status;
     pid_t child;
     if ((child = vfork()) == 0) {
         execv(path, argv);
         _exit(EXIT_FAILURE);
     }
     waitpid(child, &status, 0);
     if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
         LOG(ERROR) << path << " failed with status " << WEXITSTATUS(status);
     }
     return WEXITSTATUS(status);
 }

 static ssize_t get_file_size(int fd, uint64_t reserve_len) {
   struct stat buf;
   int ret = fstat(fd, &buf);
   if (ret) return 0;

   ssize_t computed_size;
   if (S_ISREG(buf.st_mode)) {
     computed_size = buf.st_size - reserve_len;
   } else if (S_ISBLK(buf.st_mode)) {
     computed_size = get_block_device_size(fd) - reserve_len;
   } else {
     computed_size = 0;
   }

   return computed_size;
 }

 int format_volume(const char* volume, const char* directory) {
     Volume* v = volume_for_path(volume);
     if (v == NULL) {
         LOG(ERROR) << "unknown volume \"" << volume << "\"";
         return -1;
     }
     if (strcmp(v->fs_type, "ramdisk") == 0) {
         // you can't format the ramdisk.
         LOG(ERROR) << "can't format_volume \"" << volume << "\"";
         return -1;
     }
     if (strcmp(v->mount_point, volume) != 0) {
         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 (strcmp(v->fs_type, "ext4") == 0 || strcmp(v->fs_type, "f2fs") == 0) {
         // 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 != NULL && v->key_loc[0] == '/') {
             LOG(INFO) << "wiping " << v->key_loc;
             int fd = open(v->key_loc, O_WRONLY | O_CREAT, 0644);
             if (fd < 0) {
                 LOG(ERROR) << "format_volume: failed to open " << v->key_loc;
                 return -1;
             }
             wipe_block_device(fd, get_file_size(fd));
             close(fd);
         }

         ssize_t length = 0;
         if (v->length != 0) {
             length = v->length;
         } else if (v->key_loc != NULL && strcmp(v->key_loc, "footer") == 0) {
           android::base::unique_fd fd(open(v->blk_device, O_RDONLY));
           if (fd < 0) {
             PLOG(ERROR) << "get_file_size: failed to open " << v->blk_device;
             return -1;
           }
           length = get_file_size(fd.get(), CRYPT_FOOTER_OFFSET);
           if (length <= 0) {
             LOG(ERROR) << "get_file_size: invalid size " << length << " for " << v->blk_device;
             return -1;
           }
         }
         int result;
         if (strcmp(v->fs_type, "ext4") == 0) {
           static constexpr int block_size = 4096;
           int raid_stride = v->logical_blk_size / block_size;
           int raid_stripe_width = v->erase_blk_size / block_size;

           // 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 / block_size;
           }

           const char* mke2fs_argv[] = { "/sbin/mke2fs_static",
                                         "-F",
                                         "-t",
                                         "ext4",
                                         "-b",
                                         nullptr,
                                         nullptr,
                                         nullptr,
                                         nullptr,
                                         nullptr,
                                         nullptr };

           int i = 5;
           std::string block_size_str = std::to_string(block_size);
           mke2fs_argv[i++] = block_size_str.c_str();

           std::string ext_args;
           if (v->erase_blk_size != 0 && v->logical_blk_size != 0) {
             ext_args = android::base::StringPrintf("stride=%d,stripe-width=%d", raid_stride,
                                                    raid_stripe_width);
             mke2fs_argv[i++] = "-E";
             mke2fs_argv[i++] = ext_args.c_str();
           }

           mke2fs_argv[i++] = v->blk_device;

           std::string size_str = std::to_string(length / block_size);
           if (length != 0) {
             mke2fs_argv[i++] = size_str.c_str();
           }

           result = exec_cmd(mke2fs_argv[0], const_cast<char**>(mke2fs_argv));
           if (result == 0 && directory != nullptr) {
             const char* e2fsdroid_argv[] = { "/sbin/e2fsdroid_static",
                                              "-e",
                                              "-S",
                                              "/file_contexts",
                                              "-f",
                                              directory,
                                              "-a",
                                              volume,
                                              v->blk_device,
                                              nullptr };

             result = exec_cmd(e2fsdroid_argv[0], const_cast<char**>(e2fsdroid_argv));
             }
         } else {   /* Has to be f2fs because we checked earlier. */
             char *num_sectors = nullptr;
             if (length >= 512 && asprintf(&num_sectors, "%zd", length / 512) <= 0) {
                 LOG(ERROR) << "format_volume: failed to create " << v->fs_type
                            << " command for " << v->blk_device;
                 return -1;
             }
             const char *f2fs_path = "/sbin/mkfs.f2fs";
             const char* const f2fs_argv[] = {"mkfs.f2fs", "-t", "-d1", v->blk_device, num_sectors, nullptr};

             result = exec_cmd(f2fs_path, (char* const*)f2fs_argv);
             free(num_sectors);
         }
         if (result != 0) {
             PLOG(ERROR) << "format_volume: make " << v->fs_type << " failed on " << v->blk_device;
             return -1;
         }
         return 0;
     }

     LOG(ERROR) << "format_volume: fs_type \"" << v->fs_type << "\" unsupported";
     return -1;
 }

 int format_volume(const char* volume) {
     return format_volume(volume, NULL);
 }

 int setup_install_mounts() {
   if (fstab == nullptr) {
     LOG(ERROR) << "can't set up install mounts: no fstab loaded";
     return -1;
   }
   for (int i = 0; i < fstab->num_entries; ++i) {
     const Volume* v = fstab->recs + i;

     // We don't want to do anything with "/".
     if (strcmp(v->mount_point, "/") == 0) {
       continue;
     }

     if (strcmp(v->mount_point, "/tmp") == 0 || strcmp(v->mount_point, "/cache") == 0) {
       if (ensure_path_mounted(v->mount_point) != 0) {
         LOG(ERROR) << "failed to mount " << v->mount_point;
         return -1;
       }
     } else {
       if (ensure_path_unmounted(v->mount_point) != 0) {
         LOG(ERROR) << "failed to unmount " << v->mount_point;
         return -1;
       }
     }
   }
   return 0;
 }
	/*
	* 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 <errno.h>
	#include <stdlib.h>
	#include <sys/mount.h>
	#include <sys/stat.h>
	#include <sys/types.h>
	#include <sys/wait.h>
	#include <unistd.h>
	#include <ctype.h>
	#include <fcntl.h>

	#include <android-base/logging.h>
	#include <android-base/properties.h>
	#include <android-base/stringprintf.h>
	#include <android-base/unique_fd.h>
	#include <ext4_utils/wipe.h>
	#include <fs_mgr.h>

	#include "common.h"
	#include "mounts.h"
	#include "cryptfs.h"

	static struct fstab *fstab = NULL;

	extern struct selabel_handle *sehandle;

	void load_volume_table()
	{
	int i;
	int ret;

	fstab = fs_mgr_read_fstab_default();
	if (!fstab) {
	LOG(ERROR) << "failed to read default fstab";
	return;
	}

	ret = fs_mgr_add_entry(fstab, "/tmp", "ramdisk", "ramdisk");
	if (ret < 0 ) {
	LOG(ERROR) << "failed to add /tmp entry to fstab";
	fs_mgr_free_fstab(fstab);
	fstab = NULL;
	return;
	}

	printf("recovery filesystem table\n");
	printf("=========================\n");
	for (i = 0; i < fstab->num_entries; ++i) {
	Volume* v = &fstab->recs[i];
	printf(" %d %s %s %s %lld\n", i, v->mount_point, v->fs_type,
	v->blk_device, v->length);
	}
	printf("\n");
	}

	Volume* volume_for_path(const char* path) {
	return fs_mgr_get_entry_for_mount_point(fstab, path);
	}

	// Mount the volume specified by path at the given mount_point.
	int ensure_path_mounted_at(const char* path, const char* mount_point) {
	Volume* v = volume_for_path(path);
	if (v == NULL) {
	LOG(ERROR) << "unknown volume for path [" << path << "]";
	return -1;
	}
	if (strcmp(v->fs_type, "ramdisk") == 0) {
	// the ramdisk is always mounted.
	return 0;
	}

	if (!scan_mounted_volumes()) {
	LOG(ERROR) << "failed to scan mounted volumes";
	return -1;
	}

	if (!mount_point) {
	mount_point = v->mount_point;
	}

	MountedVolume* mv = find_mounted_volume_by_mount_point(mount_point);
	if (mv) {
	// volume is already mounted
	return 0;
	}

	mkdir(mount_point, 0755); // in case it doesn't already exist

	if (strcmp(v->fs_type, "ext4") == 0 \|\|
	strcmp(v->fs_type, "squashfs") == 0 \|\|
	strcmp(v->fs_type, "vfat") == 0) {
	int result = mount(v->blk_device, mount_point, v->fs_type, v->flags, v->fs_options);
	if (result == -1 && fs_mgr_is_formattable(v)) {
	LOG(ERROR) << "failed to mount " << mount_point << " (" << strerror(errno)
	<< ") , formatting.....";
	bool crypt_footer = fs_mgr_is_encryptable(v) && !strcmp(v->key_loc, "footer");
	if (fs_mgr_do_format(v, crypt_footer) == 0) {
	result = mount(v->blk_device, mount_point, v->fs_type, v->flags, v->fs_options);
	} else {
	PLOG(ERROR) << "failed to format " << mount_point;
	return -1;
	}
	}

	if (result == -1) {
	PLOG(ERROR) << "failed to mount " << mount_point;
	return -1;
	}
	return 0;
	}

	LOG(ERROR) << "unknown fs_type \"" << v->fs_type << "\" for " << mount_point;
	return -1;
	}

	int ensure_path_mounted(const char* path) {
	// Mount at the default mount point.
	return ensure_path_mounted_at(path, nullptr);
	}

	int ensure_path_unmounted(const char* path) {
	Volume* v = volume_for_path(path);
	if (v == NULL) {
	LOG(ERROR) << "unknown volume for path [" << path << "]";
	return -1;
	}
	if (strcmp(v->fs_type, "ramdisk") == 0) {
	// the ramdisk is always mounted; you can't unmount it.
	return -1;
	}

	if (!scan_mounted_volumes()) {
	LOG(ERROR) << "failed to scan mounted volumes";
	return -1;
	}

	MountedVolume* mv = find_mounted_volume_by_mount_point(v->mount_point);
	if (mv == NULL) {
	// volume is already unmounted
	return 0;
	}

	return unmount_mounted_volume(mv);
	}

	static int exec_cmd(const char* path, char* const argv[]) {
	int status;
	pid_t child;
	if ((child = vfork()) == 0) {
	execv(path, argv);
	_exit(EXIT_FAILURE);
	}
	waitpid(child, &status, 0);
	if (!WIFEXITED(status) \|\| WEXITSTATUS(status) != 0) {
	LOG(ERROR) << path << " failed with status " << WEXITSTATUS(status);
	}
	return WEXITSTATUS(status);
	}

	static ssize_t get_file_size(int fd, uint64_t reserve_len) {
	struct stat buf;
	int ret = fstat(fd, &buf);
	if (ret) return 0;

	ssize_t computed_size;
	if (S_ISREG(buf.st_mode)) {
	computed_size = buf.st_size - reserve_len;
	} else if (S_ISBLK(buf.st_mode)) {
	computed_size = get_block_device_size(fd) - reserve_len;
	} else {
	computed_size = 0;
	}

	return computed_size;
	}

	int format_volume(const char* volume, const char* directory) {
	Volume* v = volume_for_path(volume);
	if (v == NULL) {
	LOG(ERROR) << "unknown volume \"" << volume << "\"";
	return -1;
	}
	if (strcmp(v->fs_type, "ramdisk") == 0) {
	// you can't format the ramdisk.
	LOG(ERROR) << "can't format_volume \"" << volume << "\"";
	return -1;
	}
	if (strcmp(v->mount_point, volume) != 0) {
	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 (strcmp(v->fs_type, "ext4") == 0 \|\| strcmp(v->fs_type, "f2fs") == 0) {
	// 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 != NULL && v->key_loc[0] == '/') {
	LOG(INFO) << "wiping " << v->key_loc;
	int fd = open(v->key_loc, O_WRONLY \| O_CREAT, 0644);
	if (fd < 0) {
	LOG(ERROR) << "format_volume: failed to open " << v->key_loc;
	return -1;
	}
	wipe_block_device(fd, get_file_size(fd));
	close(fd);
	}

	ssize_t length = 0;
	if (v->length != 0) {
	length = v->length;
	} else if (v->key_loc != NULL && strcmp(v->key_loc, "footer") == 0) {
	android::base::unique_fd fd(open(v->blk_device, O_RDONLY));
	if (fd < 0) {
	PLOG(ERROR) << "get_file_size: failed to open " << v->blk_device;
	return -1;
	}
	length = get_file_size(fd.get(), CRYPT_FOOTER_OFFSET);
	if (length <= 0) {
	LOG(ERROR) << "get_file_size: invalid size " << length << " for " << v->blk_device;
	return -1;
	}
	}
	int result;
	if (strcmp(v->fs_type, "ext4") == 0) {
	static constexpr int block_size = 4096;
	int raid_stride = v->logical_blk_size / block_size;
	int raid_stripe_width = v->erase_blk_size / block_size;

	// 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 / block_size;
	}

	const char* mke2fs_argv[] = { "/sbin/mke2fs_static",
	"-F",
	"-t",
	"ext4",
	"-b",
	nullptr,
	nullptr,
	nullptr,
	nullptr,
	nullptr,
	nullptr };

	int i = 5;
	std::string block_size_str = std::to_string(block_size);
	mke2fs_argv[i++] = block_size_str.c_str();

	std::string ext_args;
	if (v->erase_blk_size != 0 && v->logical_blk_size != 0) {
	ext_args = android::base::StringPrintf("stride=%d,stripe-width=%d", raid_stride,
	raid_stripe_width);
	mke2fs_argv[i++] = "-E";
	mke2fs_argv[i++] = ext_args.c_str();
	}

	mke2fs_argv[i++] = v->blk_device;

	std::string size_str = std::to_string(length / block_size);
	if (length != 0) {
	mke2fs_argv[i++] = size_str.c_str();
	}

	result = exec_cmd(mke2fs_argv[0], const_cast<char**>(mke2fs_argv));
	if (result == 0 && directory != nullptr) {
	const char* e2fsdroid_argv[] = { "/sbin/e2fsdroid_static",
	"-e",
	"-S",
	"/file_contexts",
	"-f",
	directory,
	"-a",
	volume,
	v->blk_device,
	nullptr };

	result = exec_cmd(e2fsdroid_argv[0], const_cast<char**>(e2fsdroid_argv));
	}
	} else { /* Has to be f2fs because we checked earlier. */
	char *num_sectors = nullptr;
	if (length >= 512 && asprintf(&num_sectors, "%zd", length / 512) <= 0) {
	LOG(ERROR) << "format_volume: failed to create " << v->fs_type
	<< " command for " << v->blk_device;
	return -1;
	}
	const char *f2fs_path = "/sbin/mkfs.f2fs";
	const char* const f2fs_argv[] = {"mkfs.f2fs", "-t", "-d1", v->blk_device, num_sectors, nullptr};

	result = exec_cmd(f2fs_path, (char* const*)f2fs_argv);
	free(num_sectors);
	}
	if (result != 0) {
	PLOG(ERROR) << "format_volume: make " << v->fs_type << " failed on " << v->blk_device;
	return -1;
	}
	return 0;
	}

	LOG(ERROR) << "format_volume: fs_type \"" << v->fs_type << "\" unsupported";
	return -1;
	}

	int format_volume(const char* volume) {
	return format_volume(volume, NULL);
	}

	int setup_install_mounts() {
	if (fstab == nullptr) {
	LOG(ERROR) << "can't set up install mounts: no fstab loaded";
	return -1;
	}
	for (int i = 0; i < fstab->num_entries; ++i) {
	const Volume* v = fstab->recs + i;

	// We don't want to do anything with "/".
	if (strcmp(v->mount_point, "/") == 0) {
	continue;
	}

	if (strcmp(v->mount_point, "/tmp") == 0 \|\| strcmp(v->mount_point, "/cache") == 0) {
	if (ensure_path_mounted(v->mount_point) != 0) {
	LOG(ERROR) << "failed to mount " << v->mount_point;
	return -1;
	}
	} else {
	if (ensure_path_unmounted(v->mount_point) != 0) {
	LOG(ERROR) << "failed to unmount " << v->mount_point;
	return -1;
	}
	}
	}
	return 0;
	}