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

 #include <fs_mgr.h>
 #include "mtdutils/mtdutils.h"
 #include "mtdutils/mounts.h"
 #include "roots.h"
 #include "common.h"
 #include "make_ext4fs.h"
 extern "C" {
 #include "wipe.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("/etc/recovery.fstab");
     if (!fstab) {
         LOGE("failed to read /etc/recovery.fstab\n");
         return;
     }

     ret = fs_mgr_add_entry(fstab, "/tmp", "ramdisk", "ramdisk", 0);
     if (ret < 0 ) {
         LOGE("failed to add /tmp entry to fstab\n");
         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);
 }

 int ensure_path_mounted(const char* path) {
     Volume* v = volume_for_path(path);
     if (v == NULL) {
         LOGE("unknown volume for path [%s]\n", path);
         return -1;
     }
     if (strcmp(v->fs_type, "ramdisk") == 0) {
         // the ramdisk is always mounted.
         return 0;
     }

     int result;
     result = scan_mounted_volumes();
     if (result < 0) {
         LOGE("failed to scan mounted volumes\n");
         return -1;
     }

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

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

     if (strcmp(v->fs_type, "yaffs2") == 0) {
         // mount an MTD partition as a YAFFS2 filesystem.
         mtd_scan_partitions();
         const MtdPartition* partition;
         partition = mtd_find_partition_by_name(v->blk_device);
         if (partition == NULL) {
             LOGE("failed to find \"%s\" partition to mount at \"%s\"\n",
                  v->blk_device, v->mount_point);
             return -1;
         }
         return mtd_mount_partition(partition, v->mount_point, v->fs_type, 0);
     } else if (strcmp(v->fs_type, "ext4") == 0 ||
                strcmp(v->fs_type, "vfat") == 0) {
         result = mount(v->blk_device, v->mount_point, v->fs_type,
                        MS_NOATIME | MS_NODEV | MS_NODIRATIME, "");
         if (result == 0) return 0;

         LOGE("failed to mount %s (%s)\n", v->mount_point, strerror(errno));
         return -1;
     }

     LOGE("unknown fs_type \"%s\" for %s\n", v->fs_type, v->mount_point);
     return -1;
 }

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

     int result;
     result = scan_mounted_volumes();
     if (result < 0) {
         LOGE("failed to scan mounted volumes\n");
         return -1;
     }

     const 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);
 }

 int format_volume(const char* volume) {
     Volume* v = volume_for_path(volume);
     if (v == NULL) {
         LOGE("unknown volume \"%s\"\n", volume);
         return -1;
     }
     if (strcmp(v->fs_type, "ramdisk") == 0) {
         // you can't format the ramdisk.
         LOGE("can't format_volume \"%s\"", volume);
         return -1;
     }
     if (strcmp(v->mount_point, volume) != 0) {
         LOGE("can't give path \"%s\" to format_volume\n", volume);
         return -1;
     }

     if (ensure_path_unmounted(volume) != 0) {
         LOGE("format_volume failed to unmount \"%s\"\n", v->mount_point);
         return -1;
     }

     if (strcmp(v->fs_type, "yaffs2") == 0 || strcmp(v->fs_type, "mtd") == 0) {
         mtd_scan_partitions();
         const MtdPartition* partition = mtd_find_partition_by_name(v->blk_device);
         if (partition == NULL) {
             LOGE("format_volume: no MTD partition \"%s\"\n", v->blk_device);
             return -1;
         }

         MtdWriteContext *write = mtd_write_partition(partition);
         if (write == NULL) {
             LOGW("format_volume: can't open MTD \"%s\"\n", v->blk_device);
             return -1;
         } else if (mtd_erase_blocks(write, -1) == (off_t) -1) {
             LOGW("format_volume: can't erase MTD \"%s\"\n", v->blk_device);
             mtd_write_close(write);
             return -1;
         } else if (mtd_write_close(write)) {
             LOGW("format_volume: can't close MTD \"%s\"\n", v->blk_device);
             return -1;
         }
         return 0;
     }

     if (strcmp(v->fs_type, "ext4") == 0) {
         ssize_t length = 0;
         if (v->length != 0) {
             length = v->length;
         } else if (v->key_loc != NULL && strcmp(v->key_loc, "footer") == 0) {
             length = -CRYPT_FOOTER_OFFSET;
         }
         int result = make_ext4fs(v->blk_device, length, volume, sehandle);
         if (result != 0) {
             LOGE("format_volume: make_extf4fs failed on %s\n", v->blk_device);
             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 != NULL && v->key_loc[0] == '/') {
             LOGI("wiping %s\n", v->key_loc);
             int fd = open(v->key_loc, O_WRONLY | O_CREAT, 0644);
             if (fd < 0) {
                 LOGE("format_volume: failed to open %s\n", v->key_loc);
                 return -1;
             }
             wipe_block_device(fd, get_file_size(fd));
             close(fd);
         }

         return 0;
     }

     LOGE("format_volume: fs_type \"%s\" unsupported\n", v->fs_type);
     return -1;
 }

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

         if (strcmp(v->mount_point, "/tmp") == 0 ||
             strcmp(v->mount_point, "/cache") == 0) {
             if (ensure_path_mounted(v->mount_point) != 0) {
                 LOGE("failed to mount %s\n", v->mount_point);
                 return -1;
             }

         } else {
             if (ensure_path_unmounted(v->mount_point) != 0) {
                 LOGE("failed to unmount %s\n", 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 <errno.h>
	#include <stdlib.h>
	#include <sys/mount.h>
	#include <sys/stat.h>
	#include <sys/types.h>
	#include <unistd.h>
	#include <ctype.h>
	#include <fcntl.h>

	#include <fs_mgr.h>
	#include "mtdutils/mtdutils.h"
	#include "mtdutils/mounts.h"
	#include "roots.h"
	#include "common.h"
	#include "make_ext4fs.h"
	extern "C" {
	#include "wipe.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("/etc/recovery.fstab");
	if (!fstab) {
	LOGE("failed to read /etc/recovery.fstab\n");
	return;
	}

	ret = fs_mgr_add_entry(fstab, "/tmp", "ramdisk", "ramdisk", 0);
	if (ret < 0 ) {
	LOGE("failed to add /tmp entry to fstab\n");
	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);
	}

	int ensure_path_mounted(const char* path) {
	Volume* v = volume_for_path(path);
	if (v == NULL) {
	LOGE("unknown volume for path [%s]\n", path);
	return -1;
	}
	if (strcmp(v->fs_type, "ramdisk") == 0) {
	// the ramdisk is always mounted.
	return 0;
	}

	int result;
	result = scan_mounted_volumes();
	if (result < 0) {
	LOGE("failed to scan mounted volumes\n");
	return -1;
	}

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

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

	if (strcmp(v->fs_type, "yaffs2") == 0) {
	// mount an MTD partition as a YAFFS2 filesystem.
	mtd_scan_partitions();
	const MtdPartition* partition;
	partition = mtd_find_partition_by_name(v->blk_device);
	if (partition == NULL) {
	LOGE("failed to find \"%s\" partition to mount at \"%s\"\n",
	v->blk_device, v->mount_point);
	return -1;
	}
	return mtd_mount_partition(partition, v->mount_point, v->fs_type, 0);
	} else if (strcmp(v->fs_type, "ext4") == 0 \|\|
	strcmp(v->fs_type, "vfat") == 0) {
	result = mount(v->blk_device, v->mount_point, v->fs_type,
	MS_NOATIME \| MS_NODEV \| MS_NODIRATIME, "");
	if (result == 0) return 0;

	LOGE("failed to mount %s (%s)\n", v->mount_point, strerror(errno));
	return -1;
	}

	LOGE("unknown fs_type \"%s\" for %s\n", v->fs_type, v->mount_point);
	return -1;
	}

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

	int result;
	result = scan_mounted_volumes();
	if (result < 0) {
	LOGE("failed to scan mounted volumes\n");
	return -1;
	}

	const 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);
	}

	int format_volume(const char* volume) {
	Volume* v = volume_for_path(volume);
	if (v == NULL) {
	LOGE("unknown volume \"%s\"\n", volume);
	return -1;
	}
	if (strcmp(v->fs_type, "ramdisk") == 0) {
	// you can't format the ramdisk.
	LOGE("can't format_volume \"%s\"", volume);
	return -1;
	}
	if (strcmp(v->mount_point, volume) != 0) {
	LOGE("can't give path \"%s\" to format_volume\n", volume);
	return -1;
	}

	if (ensure_path_unmounted(volume) != 0) {
	LOGE("format_volume failed to unmount \"%s\"\n", v->mount_point);
	return -1;
	}

	if (strcmp(v->fs_type, "yaffs2") == 0 \|\| strcmp(v->fs_type, "mtd") == 0) {
	mtd_scan_partitions();
	const MtdPartition* partition = mtd_find_partition_by_name(v->blk_device);
	if (partition == NULL) {
	LOGE("format_volume: no MTD partition \"%s\"\n", v->blk_device);
	return -1;
	}

	MtdWriteContext *write = mtd_write_partition(partition);
	if (write == NULL) {
	LOGW("format_volume: can't open MTD \"%s\"\n", v->blk_device);
	return -1;
	} else if (mtd_erase_blocks(write, -1) == (off_t) -1) {
	LOGW("format_volume: can't erase MTD \"%s\"\n", v->blk_device);
	mtd_write_close(write);
	return -1;
	} else if (mtd_write_close(write)) {
	LOGW("format_volume: can't close MTD \"%s\"\n", v->blk_device);
	return -1;
	}
	return 0;
	}

	if (strcmp(v->fs_type, "ext4") == 0) {
	ssize_t length = 0;
	if (v->length != 0) {
	length = v->length;
	} else if (v->key_loc != NULL && strcmp(v->key_loc, "footer") == 0) {
	length = -CRYPT_FOOTER_OFFSET;
	}
	int result = make_ext4fs(v->blk_device, length, volume, sehandle);
	if (result != 0) {
	LOGE("format_volume: make_extf4fs failed on %s\n", v->blk_device);
	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 != NULL && v->key_loc[0] == '/') {
	LOGI("wiping %s\n", v->key_loc);
	int fd = open(v->key_loc, O_WRONLY \| O_CREAT, 0644);
	if (fd < 0) {
	LOGE("format_volume: failed to open %s\n", v->key_loc);
	return -1;
	}
	wipe_block_device(fd, get_file_size(fd));
	close(fd);
	}

	return 0;
	}

	LOGE("format_volume: fs_type \"%s\" unsupported\n", v->fs_type);
	return -1;
	}

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

	if (strcmp(v->mount_point, "/tmp") == 0 \|\|
	strcmp(v->mount_point, "/cache") == 0) {
	if (ensure_path_mounted(v->mount_point) != 0) {
	LOGE("failed to mount %s\n", v->mount_point);
	return -1;
	}

	} else {
	if (ensure_path_unmounted(v->mount_point) != 0) {
	LOGE("failed to unmount %s\n", v->mount_point);
	return -1;
	}
	}
	}
	return 0;
	}