+
+off_t exfat_get_root_entry_offset(struct exfat_blk_dev *bd)
+{
+ struct pbr *bs;
+ int nbytes;
+ unsigned int cluster_size, sector_size;
+ off_t root_clu_off;
+
+ bs = (struct pbr *)malloc(EXFAT_MAX_SECTOR_SIZE);
+ if (!bs) {
+ exfat_err("failed to allocate memory\n");
+ return -ENOMEM;
+ }
+
+ nbytes = exfat_read(bd->dev_fd, bs, EXFAT_MAX_SECTOR_SIZE, 0);
+ if (nbytes != EXFAT_MAX_SECTOR_SIZE) {
+ exfat_err("boot sector read failed: %d\n", errno);
+ free(bs);
+ return -1;
+ }
+
+ sector_size = 1 << bs->bsx.sect_size_bits;
+ cluster_size = (1 << bs->bsx.sect_per_clus_bits) * sector_size;
+ root_clu_off = le32_to_cpu(bs->bsx.clu_offset) * sector_size +
+ (le32_to_cpu(bs->bsx.root_cluster) - EXFAT_RESERVED_CLUSTERS) *
+ cluster_size;
+ free(bs);
+
+ return root_clu_off;
+}
+
+char *exfat_conv_volume_label(struct exfat_dentry *vol_entry)
+{
+ char *volume_label;
+ __le16 disk_label[VOLUME_LABEL_MAX_LEN];
+
+ volume_label = malloc(VOLUME_LABEL_BUFFER_SIZE);
+ if (!volume_label)
+ return NULL;
+
+ memcpy(disk_label, vol_entry->vol_label, sizeof(disk_label));
+ memset(volume_label, 0, VOLUME_LABEL_BUFFER_SIZE);
+ if (exfat_utf16_dec(disk_label, vol_entry->vol_char_cnt*2,
+ volume_label, VOLUME_LABEL_BUFFER_SIZE) < 0) {
+ exfat_err("failed to decode volume label\n");
+ free(volume_label);
+ return NULL;
+ }
+
+ return volume_label;
+}
+
+int exfat_show_volume_label(struct exfat_blk_dev *bd, off_t root_clu_off)
+{
+ struct exfat_dentry *vol_entry;
+ char *volume_label;
+ int nbytes;
+
+ vol_entry = malloc(sizeof(struct exfat_dentry));
+ if (!vol_entry) {
+ exfat_err("failed to allocate memory\n");
+ return -ENOMEM;
+ }
+
+ nbytes = exfat_read(bd->dev_fd, vol_entry,
+ sizeof(struct exfat_dentry), root_clu_off);
+ if (nbytes != sizeof(struct exfat_dentry)) {
+ exfat_err("volume entry read failed: %d\n", errno);
+ free(vol_entry);
+ return -1;
+ }
+
+ volume_label = exfat_conv_volume_label(vol_entry);
+ if (!volume_label) {
+ free(vol_entry);
+ return -EINVAL;
+ }
+
+ exfat_info("label: %s\n", volume_label);
+
+ free(volume_label);
+ free(vol_entry);
+ return 0;
+}
+
+int exfat_set_volume_label(struct exfat_blk_dev *bd,
+ char *label_input, off_t root_clu_off)
+{
+ struct exfat_dentry vol;
+ int nbytes;
+ __u16 volume_label[VOLUME_LABEL_MAX_LEN];
+ int volume_label_len;
+
+ volume_label_len = exfat_utf16_enc(label_input,
+ volume_label, sizeof(volume_label));
+ if (volume_label_len < 0) {
+ exfat_err("failed to encode volume label\n");
+ return -1;
+ }
+
+ vol.type = EXFAT_VOLUME;
+ memset(vol.vol_label, 0, sizeof(vol.vol_label));
+ memcpy(vol.vol_label, volume_label, volume_label_len);
+ vol.vol_char_cnt = volume_label_len/2;
+
+ nbytes = exfat_write(bd->dev_fd, &vol, sizeof(struct exfat_dentry),
+ root_clu_off);
+ if (nbytes != sizeof(struct exfat_dentry)) {
+ exfat_err("volume entry write failed: %d\n", errno);
+ return -1;
+ }
+ fsync(bd->dev_fd);
+
+ exfat_info("new label: %s\n", label_input);
+ return 0;
+}
+
+int exfat_read_sector(struct exfat_blk_dev *bd, void *buf, unsigned int sec_off)
+{
+ int ret;
+ unsigned long long offset = sec_off * bd->sector_size;
+
+ lseek(bd->dev_fd, offset, SEEK_SET);
+ ret = read(bd->dev_fd, buf, bd->sector_size);
+ if (ret < 0) {
+ exfat_err("read failed, sec_off : %u\n", sec_off);
+ return -1;
+ }
+ return 0;
+}
+
+int exfat_write_sector(struct exfat_blk_dev *bd, void *buf,
+ unsigned int sec_off)
+{
+ int bytes;
+ unsigned long long offset = sec_off * bd->sector_size;
+
+ lseek(bd->dev_fd, offset, SEEK_SET);
+ bytes = write(bd->dev_fd, buf, bd->sector_size);
+ if (bytes != (int)bd->sector_size) {
+ exfat_err("write failed, sec_off : %u, bytes : %d\n", sec_off,
+ bytes);
+ return -1;
+ }
+ return 0;
+}
+
+int exfat_write_checksum_sector(struct exfat_blk_dev *bd,
+ unsigned int checksum, bool is_backup)
+{
+ __le32 *checksum_buf;
+ int ret = 0;
+ unsigned int i;
+ unsigned int sec_idx = CHECKSUM_SEC_IDX;
+
+ checksum_buf = malloc(bd->sector_size);
+ if (!checksum_buf)
+ return -1;
+
+ if (is_backup)
+ sec_idx += BACKUP_BOOT_SEC_IDX;
+
+ for (i = 0; i < bd->sector_size / sizeof(int); i++)
+ checksum_buf[i] = cpu_to_le32(checksum);
+
+ ret = exfat_write_sector(bd, checksum_buf, sec_idx);
+ if (ret) {
+ exfat_err("checksum sector write failed\n");
+ goto free;
+ }
+
+free:
+ free(checksum_buf);
+ return ret;
+}
+
+int exfat_show_volume_serial(int fd)
+{
+ struct pbr *ppbr;
+ int ret;
+
+ ppbr = malloc(EXFAT_MAX_SECTOR_SIZE);
+ if (!ppbr) {
+ exfat_err("Cannot allocate pbr: out of memory\n");
+ return -1;
+ }
+
+ /* read main boot sector */
+ ret = exfat_read(fd, (char *)ppbr, EXFAT_MAX_SECTOR_SIZE, 0);
+ if (ret < 0) {
+ exfat_err("main boot sector read failed\n");
+ ret = -1;
+ goto free_ppbr;
+ }
+
+ exfat_info("volume serial : 0x%x\n", ppbr->bsx.vol_serial);
+
+free_ppbr:
+ free(ppbr);
+ return ret;
+}
+
+static int exfat_update_boot_checksum(struct exfat_blk_dev *bd, bool is_backup)
+{
+ unsigned int checksum = 0;
+ int ret, sec_idx, backup_sec_idx = 0;
+ unsigned char *buf;
+
+ buf = malloc(bd->sector_size);
+ if (!buf) {
+ exfat_err("Cannot allocate pbr: out of memory\n");
+ return -1;
+ }
+
+ if (is_backup)
+ backup_sec_idx = BACKUP_BOOT_SEC_IDX;
+
+ for (sec_idx = BOOT_SEC_IDX; sec_idx < CHECKSUM_SEC_IDX; sec_idx++) {
+ bool is_boot_sec = false;
+
+ ret = exfat_read_sector(bd, buf, sec_idx + backup_sec_idx);
+ if (ret < 0) {
+ exfat_err("sector(%d) read failed\n", sec_idx);
+ ret = -1;
+ goto free_buf;
+ }
+
+ if (sec_idx == BOOT_SEC_IDX)
+ is_boot_sec = true;
+
+ boot_calc_checksum(buf, bd->sector_size, is_boot_sec,
+ &checksum);
+ }
+
+ ret = exfat_write_checksum_sector(bd, checksum, is_backup);
+
+free_buf:
+ free(buf);
+
+ return ret;
+}
+
+int exfat_set_volume_serial(struct exfat_blk_dev *bd,
+ struct exfat_user_input *ui)
+{
+ int ret;
+ struct pbr *ppbr;
+
+ ppbr = malloc(EXFAT_MAX_SECTOR_SIZE);
+ if (!ppbr) {
+ exfat_err("Cannot allocate pbr: out of memory\n");
+ return -1;
+ }
+
+ /* read main boot sector */
+ ret = exfat_read(bd->dev_fd, (char *)ppbr, EXFAT_MAX_SECTOR_SIZE,
+ BOOT_SEC_IDX);
+ if (ret < 0) {
+ exfat_err("main boot sector read failed\n");
+ ret = -1;
+ goto free_ppbr;
+ }
+
+ bd->sector_size = 1 << ppbr->bsx.sect_size_bits;
+ ppbr->bsx.vol_serial = ui->volume_serial;
+
+ /* update main boot sector */
+ ret = exfat_write_sector(bd, (char *)ppbr, BOOT_SEC_IDX);
+ if (ret < 0) {
+ exfat_err("main boot sector write failed\n");
+ ret = -1;
+ goto free_ppbr;
+ }
+
+ /* update backup boot sector */
+ ret = exfat_write_sector(bd, (char *)ppbr, BACKUP_BOOT_SEC_IDX);
+ if (ret < 0) {
+ exfat_err("backup boot sector write failed\n");
+ ret = -1;
+ goto free_ppbr;
+ }
+
+ ret = exfat_update_boot_checksum(bd, 0);
+ if (ret < 0) {
+ exfat_err("main checksum update failed\n");
+ goto free_ppbr;
+ }
+
+ ret = exfat_update_boot_checksum(bd, 1);
+ if (ret < 0)
+ exfat_err("backup checksum update failed\n");
+free_ppbr:
+ free(ppbr);
+
+ exfat_info("New volume serial : 0x%x\n", ui->volume_serial);
+
+ return ret;
+}
+
+unsigned int exfat_clus_to_blk_dev_off(struct exfat_blk_dev *bd,
+ unsigned int clu_off_sectnr, unsigned int clu)
+{
+ return clu_off_sectnr * bd->sector_size +
+ (clu - EXFAT_RESERVED_CLUSTERS) * bd->cluster_size;
+}