void Fat::wipe(const char *fsPath, unsigned int numSectors) { int fd; unsigned long long range[2]; fd = open(fsPath, O_RDWR); if (fd >= 0) { if (numSectors == 0) { numSectors = get_blkdev_size(fd); } if (numSectors == 0) { SLOGE("Fat wipe failed to determine size of %s", fsPath); close(fd); return; } range[0] = 0; range[1] = (unsigned long long)numSectors * 512; if (ioctl(fd, BLKDISCARD, &range) < 0) { SLOGE("Fat wipe failed to discard blocks on %s", fsPath); } else { SLOGI("Fat wipe %d sectors on %s succeeded", numSectors, fsPath); } close(fd); } else { SLOGE("Fat wipe failed to open device %s", fsPath); } }
int get_crypt_ftr_info(char **metadata_fname, off64_t *off) { static int cached_data = 0; static off64_t cached_off = 0; static char cached_metadata_fname[PROPERTY_VALUE_MAX] = ""; int fd; char key_loc[PROPERTY_VALUE_MAX]; char real_blkdev[PROPERTY_VALUE_MAX]; unsigned int nr_sec; int rc = -1; fs_mgr_get_crypt_info(fstab, key_loc, real_blkdev, sizeof(key_loc)); if (!strcmp(key_loc, KEY_IN_FOOTER)) { if ( (fd = open(real_blkdev, O_RDWR)) < 0) { printf("Cannot open real block device %s\n", real_blkdev); return -1; } if ((nr_sec = get_blkdev_size(fd))) { /* If it's an encrypted Android partition, the last 16 Kbytes contain the * encryption info footer and key, and plenty of bytes to spare for future * growth. */ strlcpy(cached_metadata_fname, real_blkdev, sizeof(cached_metadata_fname)); cached_off = ((off64_t)nr_sec * 512) - CRYPT_FOOTER_OFFSET; cached_data = 1; } else { printf("Cannot get size of block device %s\n", real_blkdev); } close(fd); } else { strlcpy(cached_metadata_fname, key_loc, sizeof(cached_metadata_fname)); cached_off = 0; cached_data = 1; } if (cached_data) { if (metadata_fname) { *metadata_fname = cached_metadata_fname; } if (off) { *off = cached_off; } rc = 0; } return rc; }
static ssize_t romdisk_read(struct blkdev * dev, u8_t * buf, size_t blkno, size_t blkcnt) { struct romdisk * romdisk = (struct romdisk *)(dev->driver); u8_t * p = (u8_t *)(romdisk->start); loff_t offset = get_blkdev_offset(dev, blkno); size_t size = get_blkdev_size(dev) * blkcnt; if(offset < 0) return 0; if(size < 0) return 0; memcpy((void *)buf, (const void *)(p + offset), size); return blkcnt; }
int main(void) { char key_loc[PROPERTY_VALUE_MAX]; char blk_dev[PROPERTY_VALUE_MAX]; char fstab_filename[PROPERTY_VALUE_MAX + sizeof(FSTAB_PREFIX)]; struct stat st; struct crypt_mnt_ftr crypt_ftr; int fdout; printf("This tool comes with no warranties whatsoever.\n"); printf("http://teamw.in\n\n"); strcpy(fstab_filename, FSTAB_PREFIX); property_get("ro.hardware", fstab_filename + sizeof(FSTAB_PREFIX) - 1, ""); if (stat(fstab_filename, &st) != 0) { printf("Cannot locate fstab file '%s'\n", fstab_filename); return -1; } fstab = fs_mgr_read_fstab(fstab_filename); if (!fstab) { printf("failed to open %s\n", fstab_filename); return -1; } fs_mgr_get_crypt_info(fstab, key_loc, blk_dev, sizeof(blk_dev)); if (get_crypt_ftr_and_key(&crypt_ftr)) { printf("Error getting crypt footer and key\n"); return -1; } if ( (fdout = open("/footerfile", O_WRONLY | O_CREAT, 0644)) < 0) { printf("Cannot open output file /footerfile\n"); return -1; } if (write(fdout, (void*) &crypt_ftr, sizeof(struct crypt_mnt_ftr)) != sizeof(struct crypt_mnt_ftr)) { printf("Failed to write footer.\n"); } close(fdout); if (!strcmp(key_loc, KEY_IN_FOOTER)) { unsigned int nr_sec, cnt; off64_t off = 0; char buffer[CRYPT_FOOTER_OFFSET]; int fd; printf("\n\nDumping footer from '%s'...\n", blk_dev); if ( (fd = open(blk_dev, O_RDONLY)) < 0) { printf("Cannot open real block device %s\n", blk_dev); return -1; } if ((nr_sec = get_blkdev_size(fd))) { off = ((off64_t)nr_sec * 512) - CRYPT_FOOTER_OFFSET; } else { printf("Cannot get size of block device %s\n", blk_dev); close(fd); return -1; } printf("Size is %llu, offset is %llu\n", ((off64_t)nr_sec * 512), off); if (lseek64(fd, off, SEEK_SET) == -1) { printf("Cannot seek to real block device footer\n"); close(fd); return -1; } if ( (cnt = read(fd, buffer, sizeof(buffer))) != sizeof(buffer)) { printf("Cannot read real block device footer\n"); close(fd); return -1; } close(fd); if ( (fdout = open("/footerdump", O_WRONLY | O_CREAT, 0644)) < 0) { printf("Cannot open output file /footerdump\n"); return -1; } if (write(fdout, buffer, sizeof(buffer)) != sizeof(buffer)) { printf("Failed to write footer.\n"); } close(fdout); } return 0; }