roots.cpp

/*
 * 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>

extern "C" {
#include "mtdutils/mtdutils.h"
#include "mtdutils/mounts.h"
#include "flashutils/flashutils.h"
#include "bmlutils/bmlutils.h"
#include "mmcutils/mmcutils.h"
#include "libcrecovery/common.h"
#include "make_ext4fs.h"
}

#include "selinux/label.h" //get the struct selabel_handle;
#include "selinux/selinux.h" 

#include "roots.h"
#include "common.h"

struct selabel_handle* handle;
static char **BACKUP_FORMAT;
int num_volumes;
Volume* device_volumes;

int get_num_volumes() {
    return num_volumes;
}

Volume* get_device_volumes() {
    return device_volumes;
}

static int is_null(const char* sz) {
    if (sz == NULL)
        return 1;
    if (strcmp("NULL", sz) == 0)
        return 1;
    return 0;
}

static char* dupe_string(const char* sz) {
    if (is_null(sz))
        return NULL;
    return strdup(sz);
}

static int parse_options(char* options, Volume* volume) {
    char* option;
    while (option = strtok(options, ",")) {
        options = NULL;

        if (strncmp(option, "length=", 7) == 0) {
            volume->length = strtoll(option+7, NULL, 10);
        } else if (strncmp(option, "fstype2=", 8) == 0) {
            volume->fs_type2 = volume->fs_type;
            volume->fs_type = strdup(option + 8);
        } else if (strncmp(option, "fs_options=", 11) == 0) {
            volume->fs_options = strdup(option + 11);
        } else if (strncmp(option, "fs_options2=", 12) == 0) {
            volume->fs_options2 = strdup(option + 12);
        } else {
            LOGE("bad option \"%s\"\n", option);
            return -1;
        }
    }
    return 0;
}

void load_volume_table() {
    int alloc = 2;
    device_volumes = (Volume*)malloc(alloc * sizeof(Volume));
    BACKUP_FORMAT = (char**)malloc(alloc * sizeof(char*));

    // Insert an entry for /tmp, which is the ramdisk and is always mounted.
    device_volumes[0].mount_point = "/tmp";
    device_volumes[0].fs_type = "ramdisk";
    device_volumes[0].device = NULL;
    device_volumes[0].device2 = NULL;
    device_volumes[0].fs_type2 = NULL;
    device_volumes[0].fs_options = NULL;
    device_volumes[0].fs_options2 = NULL;
    device_volumes[0].length = 0;
    BACKUP_FORMAT[0] = NULL;
    num_volumes = 1;

    FILE* fstab = fopen("/etc/recovery.fstab", "r");
    if (fstab == NULL) {
        LOGE("failed to open /etc/recovery.fstab (%s)\n", strerror(errno));
        return;
    }

    char buffer[1024];
    int i;
    while (fgets(buffer, sizeof(buffer)-1, fstab)) {
        for (i = 0; buffer[i] && isspace(buffer[i]); ++i);
        if (buffer[i] == '\0' || buffer[i] == '#') continue;

        char* original = strdup(buffer);

        char* mount_point = strtok(buffer+i, " \t\n");
        char* fs_type = strtok(NULL, " \t\n");
        char* device = strtok(NULL, " \t\n");
        // lines may optionally have a second device, to use if
        // mounting the first one fails.
        char* options = NULL;
        char* device2 = strtok(NULL, " \t\n");
        if (device2) {
            if (device2[0] == '/') {
                options = strtok(NULL, " \t\n");
            } else {
                options = device2;
                device2 = NULL;
            }
        }

        if (mount_point && fs_type && device) {
            while (num_volumes >= alloc) {
                alloc *= 2;
                device_volumes = (Volume*)realloc(device_volumes, alloc*sizeof(Volume));
		BACKUP_FORMAT = (char**)realloc(BACKUP_FORMAT, alloc * sizeof(char*));
            }
            device_volumes[num_volumes].mount_point = strdup(mount_point);
            device_volumes[num_volumes].fs_type = strdup(fs_type);
            device_volumes[num_volumes].device = strdup(device);
            device_volumes[num_volumes].device2 =
                device2 ? strdup(device2) : NULL;

            device_volumes[num_volumes].length = 0;

            device_volumes[num_volumes].fs_type2 = NULL;
            device_volumes[num_volumes].fs_options = NULL;
            device_volumes[num_volumes].fs_options2 = NULL;
	    if (strncmp(fs_type, "emmc",4) == 0 ||
			    strncmp(fs_type, "mtd", 3) == 0 ||
			    strncmp(fs_type, "bml", 3) == 0) {
		    BACKUP_FORMAT[num_volumes] = strdup("DD");
	    } else if  (strncmp(fs_type, "ext4", 4) == 0 ||
			    strncmp(fs_type, "ext3", 4) == 0 ||
			    strncmp(fs_type, "vfat", 4) == 0 ||
			    strncmp(fs_type, "rfs" , 3) == 0) {
		    BACKUP_FORMAT[num_volumes] = strdup("FILES");
	    } else {
		    BACKUP_FORMAT[num_volumes] = strdup(" ");
	    }

	   
	    

            if (parse_options(options, device_volumes + num_volumes) != 0) {
                LOGE("skipping malformed recovery.fstab line: %s\n", original);
            } else {
                ++num_volumes;
            }
        } else {
            LOGE("skipping malformed recovery.fstab line: %s\n", original);
        }
        free(original);
    }

    fclose(fstab);

    printf("recovery filesystem table\n");
    printf("=========================\n");
    for (i = 0; i < num_volumes; i++) {
        Volume* v = &device_volumes[i];
        printf(" Index: %d\nMount point: %s\nFS_TYPE: %s\nDevice: %s\nDevice2: %s\nLength: %lld\n BACKUP_FORMAT: %s\n\n", i, v->mount_point, v->fs_type,
               v->device, v->device2, v->length,BACKUP_FORMAT[i]);
    }
    printf("\n");

    for(i = 0; i < num_volumes; ++i) {
	    free(BACKUP_FORMAT[i]);
    }
    free(BACKUP_FORMAT);
}
/*
 * Volume* volume_for_path(const char* path) 
 * @path, parase need to check ,if it exist on the recovery.fstab 
 * if exist return the struct of volume 
 * if not exist return NULL
 *
 *
 */
Volume* volume_for_path(const char* path) {
    int i;
    for (i = 0; i < num_volumes; ++i) {
        Volume* v = device_volumes+i;
        int len = strlen(v->mount_point);
        if (strncmp(path, v->mount_point, len) == 0 &&
            (path[len] == '\0' || path[len] == '/')) {
            return v;
        }
    }
    return NULL;
}

int try_mount(const char* device, const char* mount_point, const char* fs_type, const char* fs_options) {
    if (device == NULL || mount_point == NULL || fs_type == NULL)
        return -1;
    int ret = 0;
    if (fs_options == NULL) {
        ret = mount(device, mount_point, fs_type,
                       MS_NOATIME | MS_NODEV | MS_NODIRATIME, "");
    }
    else {
        char mount_cmd[PATH_MAX];
        sprintf(mount_cmd, "mount -t %s -o%s %s %s", fs_type, fs_options, device, mount_point);
        ret = __system(mount_cmd);
    }
    if (ret == 0)
        return 0;
    LOGW("failed to mount %s (%s)\n", device, strerror(errno));
    return ret;
}

int is_data_media() {
    int i;
    for (i = 0; i < num_volumes; i++) {
        Volume* vol = device_volumes + i;
        if (strcmp(vol->fs_type, "datamedia") == 0)
            return 1;
        if (strcmp(vol->fs_type, "datashare") == 0)
            return 1;
    }
    return 0;
}

void setup_data_media() {
    int i;
    for (i = 0; i < num_volumes; i++) {
        Volume* vol = device_volumes + i;
        if (strcmp(vol->fs_type, "datamedia") == 0) {
            rmdir(vol->mount_point);
            mkdir("/data/media", 0755);
            symlink("/data/media", vol->mount_point);
            return;
        }
        if (strcmp(vol->fs_type, "datashare") == 0) {
            rmdir(vol->mount_point);
            mkdir("/data/share", 0755);
            symlink("/data/share", vol->mount_point);
            return;
        }
    }
}

int is_data_media_volume_path(const char* path) {
    Volume* v = volume_for_path(path);
    return strcmp(v->fs_type, "datamedia") == 0 || strcmp(v->fs_type, "datashare") == 0;
}

int ensure_path_mounted(const char* path) {
    return ensure_path_mounted_at_mount_point(path, NULL);
}

int ensure_path_mounted_at_mount_point(const char* path, const char* mount_point) {
    Volume* v = volume_for_path(path);
    if (v == NULL) {
        LOGE("unknown volume for path [%s]\n", path);
        return -1;
    }
    if (is_data_media_volume_path(path)) {
        LOGI("using /data/media or /data/share for %s.\n", path);
        int ret;
        if (0 != (ret = ensure_path_mounted("/data")))
            return ret;
        setup_data_media();
        return 0;
    }
    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;
    }

    if (NULL == mount_point)
        mount_point = v->mount_point;

    const 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, "ext3") == 0 ||
               strcmp(v->fs_type, "rfs") == 0 ||
               strcmp(v->fs_type, "vfat") == 0) {
        if ((result = try_mount(v->device, mount_point, v->fs_type, v->fs_options)) == 0)
            return 0;
        if ((result = try_mount(v->device2, mount_point, v->fs_type, v->fs_options)) == 0)
            return 0;
        if ((result = try_mount(v->device, mount_point, v->fs_type2, v->fs_options2)) == 0)
            return 0;
        if ((result = try_mount(v->device2, mount_point, v->fs_type2, v->fs_options2)) == 0)
            return 0;
        return result;
    } else {
        // let's try mounting with the mount binary and hope for the best.
        char mount_cmd[PATH_MAX];
        sprintf(mount_cmd, "mount %s", path);
        return __system(mount_cmd);
    }

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

int ensure_path_unmounted(const char* path) {
    // if we are using /data/media, do not ever unmount volumes /data or /sdcard
    if (strstr(path, "/data") == path && is_data_media()) {
        return 0;
    }

    Volume* v = volume_for_path(path);
    if (v == NULL) {
        LOGE("unknown volume for path [%s]\n", path);
        return -1;
    }
    if (is_data_media_volume_path(path)) {
        return ensure_path_unmounted("/data");
    }
    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) {
        // silent failure for sd-ext
        if (strcmp(volume, "/sd-ext") == 0)
            return -1;
        LOGE("unknown volume \"%s\"\n", volume);
        return -1;
    }
    if (is_data_media_volume_path(volume)) {
        return format_unknown_device(NULL, volume, NULL);
    }
    // check to see if /data is being formatted, and if it is /data/media
    // Note: the /sdcard check is redundant probably, just being safe.
    if (strstr(volume, "/data") == volume && is_data_media()) {
        return format_unknown_device(NULL, volume, NULL);
    }
    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) {
#if 0
        LOGE("can't give path \"%s\" to format_volume\n", volume);
        return -1;
#endif
        return format_unknown_device(v->device, volume, NULL);
    }

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


    if (strcmp(v->fs_type, "ext4") == 0) {
        int result = make_ext4fs(v->device, v->length, volume, handle );
        if (result != 0) {
            LOGE("format_volume: make_extf4fs failed on %s\n", v->device);
            return -1;
        }
        return 0;
    }

#if 0
    LOGE("format_volume: fs_type \"%s\" unsupported\n", v->fs_type);
    return -1;
#endif
    return format_unknown_device(v->device, volume, v->fs_type);
}

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

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

    const MountedVolume* mv =
        find_mounted_volume_by_mount_point(v->mount_point);
    if (mv) {
        // volume is already mounted
        return 1;
    }
    return 0;
}

int has_datadata() {
    Volume *vol = volume_for_path("/datadata");
    return vol != NULL;
}

#define MKE2FS_BIN      "/sbin/mke2fs"
#define TUNE2FS_BIN     "/sbin/tune2fs"
#define E2FSCK_BIN      "/sbin/e2fsck"

static int handle_data_media = 0;

int format_device(const char *device, const char *path, const char *fs_type) {
    Volume* v = volume_for_path(path);
    if (v == NULL) {
        // no /sdcard? let's assume /data/media
        if (strstr(path, "/sdcard") == path && is_data_media()) {
            return format_unknown_device(NULL, path, NULL);
        }
        // silent failure for sd-ext
        if (strcmp(path, "/sd-ext") == 0)
            return -1;
        LOGE("unknown volume \"%s\"\n", path);
        return -1;
    }
    if (strstr(path, "/data") == path && volume_for_path("/sdcard") == NULL && is_data_media()) {
        return format_unknown_device(NULL, path, NULL);
    }
    if (strcmp(fs_type, "ramdisk") == 0) {
        // you can't format the ramdisk.
        LOGE("can't format_volume \"%s\"", path);
        return -1;
    }

    if (strcmp(fs_type, "rfs") == 0) {
        if (ensure_path_unmounted(path) != 0) {
            LOGE("format_volume failed to unmount \"%s\"\n", v->mount_point);
            return -1;
        }
        if (0 != format_rfs_device(device, path)) {
            LOGE("format_volume: format_rfs_device failed on %s\n", device);
            return -1;
        }
        return 0;
    }
 
    if (strcmp(v->mount_point, path) != 0) {
        return format_unknown_device(v->device, path, NULL);
    }

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

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

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

    if (strcmp(fs_type, "ext4") == 0) {
        int length = 0;
        if (strcmp(v->fs_type, "ext4") == 0) {
            // Our desired filesystem matches the one in fstab, respect v->length
           // length = v->length;
        }
        reset_ext4fs_info();
       // int result = make_ext4fs(device, length);
       int result = make_ext4fs(device, v->length, path, handle);
        if (result != 0) {
            LOGE("format_volume: make_extf4fs failed on %s\n", device);
            return -1;
        }
        return 0;
    }

    return format_unknown_device(device, path, fs_type);
}

int format_unknown_device(const char *device, const char* path, const char *fs_type)
{
    LOGI("Formatting unknown device.\n");

    if (fs_type != NULL && get_flash_type(fs_type) != UNSUPPORTED)
        return erase_raw_partition(fs_type, device);

    // if this is SDEXT:, don't worry about it if it does not exist.
    if (0 == strcmp(path, "/sd-ext"))
    {
        struct stat st;
        Volume *vol = volume_for_path("/sd-ext");
        if (vol == NULL || 0 != stat(vol->device, &st))
        {
            ui_print("No app2sd partition found. Skipping format of /sd-ext.\n");
            return 0;
        }
    }

    if (NULL != fs_type) {
        if (strcmp("ext3", fs_type) == 0) {
            LOGI("Formatting ext3 device.\n");
            if (0 != ensure_path_unmounted(path)) {
                LOGE("Error while unmounting %s.\n", path);
                return -12;
            }
            return format_ext3_device(device);
        }

        if (strcmp("ext2", fs_type) == 0) {
            LOGI("Formatting ext2 device.\n");
            if (0 != ensure_path_unmounted(path)) {
                LOGE("Error while unmounting %s.\n", path);
                return -12;
            }
            return format_ext2_device(device);
        }
    }

    if (0 != ensure_path_mounted(path))
    {
        ui_print("Error mounting %s!\n", path);
        ui_print("Skipping format...\n");
        return 0;
    }

    static char tmp[PATH_MAX];
    if (strcmp(path, "/data") == 0) {
        sprintf(tmp, "cd /data ; for f in $(ls -a | grep -v ^[media|share]$); do rm -rf $f; done");
        __system(tmp);
    }
    else {
        sprintf(tmp, "rm -rf %s/*", path);
        __system(tmp);
        sprintf(tmp, "rm -rf %s/.*", path);
        __system(tmp);
    }

    ensure_path_unmounted(path);
    return 0;
}