diff options
Diffstat (limited to 'lib/libexfat.c')
| -rw-r--r-- | lib/libexfat.c | 1019 |
1 files changed, 1019 insertions, 0 deletions
diff --git a/lib/libexfat.c b/lib/libexfat.c new file mode 100644 index 0000000..d7b8344 --- /dev/null +++ b/lib/libexfat.c @@ -0,0 +1,1019 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2019 Namjae Jeon <linkinjeon@kernel.org> + */ + +#include <sys/types.h> +#include <sys/stat.h> +#include <sys/ioctl.h> +#include <sys/sysmacros.h> +#include <unistd.h> +#include <fcntl.h> +#include <stdlib.h> +#include <stdio.h> +#include <string.h> +#include <errno.h> +#include <wchar.h> +#include <limits.h> +#include <assert.h> + +#include "exfat_ondisk.h" +#include "libexfat.h" +#include "version.h" +#include "exfat_fs.h" +#include "exfat_dir.h" + +unsigned int print_level = EXFAT_INFO; + +void exfat_bitmap_set_range(struct exfat *exfat, char *bitmap, + clus_t start_clus, clus_t count) +{ + clus_t clus; + + if (!exfat_heap_clus(exfat, start_clus) || + !exfat_heap_clus(exfat, start_clus + count - 1)) + return; + + clus = start_clus; + while (clus < start_clus + count) { + exfat_bitmap_set(bitmap, clus); + clus++; + } +} + +static int exfat_bitmap_find_bit(struct exfat *exfat, char *bmap, + clus_t start_clu, clus_t *next, + int bit) +{ + clus_t last_clu; + + last_clu = le32_to_cpu(exfat->bs->bsx.clu_count) + + EXFAT_FIRST_CLUSTER; + while (start_clu < last_clu) { + if (!!exfat_bitmap_get(bmap, start_clu) == bit) { + *next = start_clu; + return 0; + } + start_clu++; + } + return 1; +} + +int exfat_bitmap_find_zero(struct exfat *exfat, char *bmap, + clus_t start_clu, clus_t *next) +{ + return exfat_bitmap_find_bit(exfat, bmap, + start_clu, next, 0); +} + +int exfat_bitmap_find_one(struct exfat *exfat, char *bmap, + clus_t start_clu, clus_t *next) +{ + return exfat_bitmap_find_bit(exfat, bmap, + start_clu, next, 1); +} + +wchar_t exfat_bad_char(wchar_t w) +{ + return (w < 0x0020) + || (w == '*') || (w == '?') || (w == '<') || (w == '>') + || (w == '|') || (w == '"') || (w == ':') || (w == '/') + || (w == '\\'); +} + +void boot_calc_checksum(unsigned char *sector, unsigned short size, + bool is_boot_sec, __le32 *checksum) +{ + unsigned int index; + + if (is_boot_sec) { + for (index = 0; index < size; index++) { + if ((index == 106) || (index == 107) || (index == 112)) + continue; + *checksum = ((*checksum & 1) ? 0x80000000 : 0) + + (*checksum >> 1) + sector[index]; + } + } else { + for (index = 0; index < size; index++) { + *checksum = ((*checksum & 1) ? 0x80000000 : 0) + + (*checksum >> 1) + sector[index]; + } + } +} + +void show_version(void) +{ + printf("exfatprogs version : %s\n", EXFAT_PROGS_VERSION); +} + +static inline unsigned int sector_size_bits(unsigned int size) +{ + unsigned int bits = 8; + + do { + bits++; + size >>= 1; + } while (size > 256); + + return bits; +} + +static void exfat_set_default_cluster_size(struct exfat_blk_dev *bd, + struct exfat_user_input *ui) +{ + if (256 * MB >= bd->size) + ui->cluster_size = 4 * KB; + else if (32 * GB >= bd->size) + ui->cluster_size = 32 * KB; + else + ui->cluster_size = 128 * KB; +} + +void init_user_input(struct exfat_user_input *ui) +{ + memset(ui, 0, sizeof(struct exfat_user_input)); + ui->writeable = true; + ui->quick = true; +} + +int exfat_get_blk_dev_info(struct exfat_user_input *ui, + struct exfat_blk_dev *bd) +{ + int fd, ret = -1; + off_t blk_dev_size; + struct stat st; + unsigned long long blk_dev_offset = 0; + + fd = open(ui->dev_name, ui->writeable ? O_RDWR|O_EXCL : O_RDONLY); + if (fd < 0) { + exfat_err("open failed : %s, %s\n", ui->dev_name, + strerror(errno)); + return -1; + } + blk_dev_size = lseek(fd, 0, SEEK_END); + if (blk_dev_size <= 0) { + exfat_err("invalid block device size(%s)\n", + ui->dev_name); + ret = blk_dev_size; + close(fd); + goto out; + } + + if (fstat(fd, &st) == 0 && S_ISBLK(st.st_mode)) { + char pathname[sizeof("/sys/dev/block/4294967295:4294967295/start")]; + FILE *fp; + + snprintf(pathname, sizeof(pathname), "/sys/dev/block/%u:%u/start", + major(st.st_rdev), minor(st.st_rdev)); + fp = fopen(pathname, "r"); + if (fp != NULL) { + if (fscanf(fp, "%llu", &blk_dev_offset) == 1) { + /* + * Linux kernel always reports partition offset + * in 512-byte units, regardless of sector size + */ + blk_dev_offset <<= 9; + } + fclose(fp); + } + } + + bd->dev_fd = fd; + bd->offset = blk_dev_offset; + bd->size = blk_dev_size; + if (!ui->cluster_size) + exfat_set_default_cluster_size(bd, ui); + + if (!ui->boundary_align) + ui->boundary_align = DEFAULT_BOUNDARY_ALIGNMENT; + + if (ioctl(fd, BLKSSZGET, &bd->sector_size) < 0) + bd->sector_size = DEFAULT_SECTOR_SIZE; + bd->sector_size_bits = sector_size_bits(bd->sector_size); + bd->num_sectors = blk_dev_size / bd->sector_size; + bd->num_clusters = blk_dev_size / ui->cluster_size; + + exfat_debug("Block device name : %s\n", ui->dev_name); + exfat_debug("Block device offset : %llu\n", bd->offset); + exfat_debug("Block device size : %llu\n", bd->size); + exfat_debug("Block sector size : %u\n", bd->sector_size); + exfat_debug("Number of the sectors : %llu\n", + bd->num_sectors); + exfat_debug("Number of the clusters : %u\n", + bd->num_clusters); + + ret = 0; + bd->dev_fd = fd; +out: + return ret; +} + +ssize_t exfat_read(int fd, void *buf, size_t size, off_t offset) +{ + return pread(fd, buf, size, offset); +} + +ssize_t exfat_write(int fd, void *buf, size_t size, off_t offset) +{ + return pwrite(fd, buf, size, offset); +} + +size_t exfat_utf16_len(const __le16 *str, size_t max_size) +{ + size_t i = 0; + + while (le16_to_cpu(str[i]) && i < max_size) + i++; + return i; +} + +ssize_t exfat_utf16_enc(const char *in_str, __u16 *out_str, size_t out_size) +{ + size_t mbs_len, out_len, i; + wchar_t *wcs; + + mbs_len = mbstowcs(NULL, in_str, 0); + if (mbs_len == (size_t)-1) { + if (errno == EINVAL || errno == EILSEQ) + exfat_err("invalid character sequence in current locale\n"); + return -errno; + } + + wcs = calloc(mbs_len+1, sizeof(wchar_t)); + if (!wcs) + return -ENOMEM; + + /* First convert multibyte char* string to wchar_t* string */ + if (mbstowcs(wcs, in_str, mbs_len+1) == (size_t)-1) { + if (errno == EINVAL || errno == EILSEQ) + exfat_err("invalid character sequence in current locale\n"); + free(wcs); + return -errno; + } + + /* Convert wchar_t* string (sequence of code points) to UTF-16 string */ + for (i = 0, out_len = 0; i < mbs_len; i++) { + if (2*(out_len+1) > out_size || + (wcs[i] >= 0x10000 && 2*(out_len+2) > out_size)) { + exfat_err("input string is too long\n"); + free(wcs); + return -E2BIG; + } + + /* Encode code point above Plane0 as UTF-16 surrogate pair */ + if (wcs[i] >= 0x10000) { + out_str[out_len++] = + cpu_to_le16(((wcs[i] - 0x10000) >> 10) + 0xD800); + wcs[i] = ((wcs[i] - 0x10000) & 0x3FF) + 0xDC00; + } + + out_str[out_len++] = cpu_to_le16(wcs[i]); + } + + free(wcs); + return 2*out_len; +} + +ssize_t exfat_utf16_dec(const __u16 *in_str, size_t in_len, + char *out_str, size_t out_size) +{ + size_t wcs_len, out_len, c_len, i; + char c_str[MB_LEN_MAX]; + wchar_t *wcs; + mbstate_t ps; + wchar_t w; + + wcs = calloc(in_len/2+1, sizeof(wchar_t)); + if (!wcs) + return -ENOMEM; + + /* First convert UTF-16 string to wchar_t* string */ + for (i = 0, wcs_len = 0; i < in_len/2; i++, wcs_len++) { + wcs[wcs_len] = le16_to_cpu(in_str[i]); + /* + * If wchar_t can store code point above Plane0 + * then unpack UTF-16 surrogate pair to code point + */ +#if WCHAR_MAX >= 0x10FFFF + if (wcs[wcs_len] >= 0xD800 && wcs[wcs_len] <= 0xDBFF && + i+1 < in_len/2) { + w = le16_to_cpu(in_str[i+1]); + if (w >= 0xDC00 && w <= 0xDFFF) { + wcs[wcs_len] = 0x10000 + + ((wcs[wcs_len] - 0xD800) << 10) + + (w - 0xDC00); + i++; + } + } +#endif + } + + memset(&ps, 0, sizeof(ps)); + + /* And then convert wchar_t* string to multibyte char* string */ + for (i = 0, out_len = 0, c_len = 0; i <= wcs_len; i++) { + c_len = wcrtomb(c_str, wcs[i], &ps); + /* + * If character is non-representable in current locale then + * try to store it as Unicode replacement code point U+FFFD + */ + if (c_len == (size_t)-1 && errno == EILSEQ) + c_len = wcrtomb(c_str, 0xFFFD, &ps); + /* If U+FFFD is also non-representable, try question mark */ + if (c_len == (size_t)-1 && errno == EILSEQ) + c_len = wcrtomb(c_str, L'?', &ps); + /* If also (7bit) question mark fails then we cannot do more */ + if (c_len == (size_t)-1) { + exfat_err("invalid UTF-16 sequence\n"); + free(wcs); + return -errno; + } + if (out_len+c_len > out_size) { + exfat_err("input string is too long\n"); + free(wcs); + return -E2BIG; + } + memcpy(out_str+out_len, c_str, c_len); + out_len += c_len; + } + + free(wcs); + + /* Last iteration of above loop should have produced null byte */ + if (c_len == 0 || out_str[out_len-1] != 0) { + exfat_err("invalid UTF-16 sequence\n"); + return -errno; + } + + return out_len-1; +} + +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; + } + + if (memcmp(bs->bpb.oem_name, "EXFAT ", 8) != 0) { + exfat_err("Bad fs_name in boot sector, which does not describe a valid exfat filesystem\n"); + 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_read_volume_label(struct exfat *exfat) +{ + struct exfat_dentry *dentry; + int err; + __le16 disk_label[VOLUME_LABEL_MAX_LEN]; + struct exfat_lookup_filter filter = { + .in.type = EXFAT_VOLUME, + .in.dentry_count = 0, + .in.filter = NULL, + }; + + err = exfat_lookup_dentry_set(exfat, exfat->root, &filter); + if (err) + return err; + + dentry = filter.out.dentry_set; + + if (dentry->vol_char_cnt == 0) + goto out; + + if (dentry->vol_char_cnt > VOLUME_LABEL_MAX_LEN) { + exfat_err("too long label. %d\n", dentry->vol_char_cnt); + err = -EINVAL; + goto out; + } + + memcpy(disk_label, dentry->vol_label, sizeof(disk_label)); + if (exfat_utf16_dec(disk_label, dentry->vol_char_cnt*2, + exfat->volume_label, sizeof(exfat->volume_label)) < 0) { + exfat_err("failed to decode volume label\n"); + err = -EINVAL; + goto out; + } + + exfat_info("label: %s\n", exfat->volume_label); +out: + free(filter.out.dentry_set); + return err; +} + +int exfat_set_volume_label(struct exfat *exfat, char *label_input) +{ + struct exfat_dentry *pvol; + struct exfat_dentry_loc loc; + __u16 volume_label[VOLUME_LABEL_MAX_LEN]; + int volume_label_len, dcount, err; + + struct exfat_lookup_filter filter = { + .in.type = EXFAT_VOLUME, + .in.dentry_count = 1, + .in.filter = NULL, + }; + + err = exfat_lookup_dentry_set(exfat, exfat->root, &filter); + if (!err) { + pvol = filter.out.dentry_set; + dcount = filter.out.dentry_count; + memset(pvol->vol_label, 0, sizeof(pvol->vol_label)); + } else { + pvol = calloc(sizeof(struct exfat_dentry), 1); + if (!pvol) + return -ENOMEM; + + dcount = 1; + pvol->type = EXFAT_VOLUME; + } + + 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"); + free(pvol); + return -1; + } + + memcpy(pvol->vol_label, volume_label, volume_label_len); + pvol->vol_char_cnt = volume_label_len/2; + + loc.parent = exfat->root; + loc.file_offset = filter.out.file_offset; + loc.dev_offset = filter.out.dev_offset; + err = exfat_add_dentry_set(exfat, &loc, pvol, dcount, false); + exfat_info("new label: %s\n", label_input); + + free(pvol); + + return err; +} + +static inline void print_guid(const char *msg, const __u8 *guid) +{ + exfat_info("%s: %02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x\n", + msg, + guid[0], guid[1], guid[2], guid[3], + guid[4], guid[5], guid[5], guid[7], + guid[8], guid[9], guid[10], guid[11], + guid[12], guid[13], guid[14], guid[15]); +} + +static int set_guid(__u8 *guid, const char *input) +{ + int i, j, zero_len = 0; + int len = strlen(input); + + if (len != VOLUME_GUID_LEN * 2 && len != VOLUME_GUID_LEN * 2 + 4) { + exfat_err("invalid format for volume guid\n"); + return -EINVAL; + } + + for (i = 0, j = 0; i < len; i++) { + unsigned char ch = input[i]; + + if (ch >= '0' && ch <= '9') + ch -= '0'; + else if (ch >= 'a' && ch <= 'f') + ch -= 'a' - 0xA; + else if (ch >= 'A' && ch <= 'F') + ch -= 'A' - 0xA; + else if (ch == '-' && len == VOLUME_GUID_LEN * 2 + 4 && + (i == 8 || i == 13 || i == 18 || i == 23)) + continue; + else { + exfat_err("invalid character '%c' for volume GUID\n", ch); + return -EINVAL; + } + + if (j & 1) + guid[j >> 1] |= ch; + else + guid[j >> 1] = ch << 4; + + j++; + + if (ch == 0) + zero_len++; + } + + if (zero_len == VOLUME_GUID_LEN * 2) { + exfat_err("%s is invalid for volume GUID\n", input); + return -EINVAL; + } + + return 0; +} + +int exfat_read_volume_guid(struct exfat *exfat) +{ + int err; + uint16_t checksum = 0; + struct exfat_dentry *dentry; + struct exfat_lookup_filter filter = { + .in.type = EXFAT_GUID, + .in.dentry_count = 1, + .in.filter = NULL, + }; + + err = exfat_lookup_dentry_set(exfat, exfat->root, &filter); + if (err) + return err; + + dentry = filter.out.dentry_set; + exfat_calc_dentry_checksum(dentry, &checksum, true); + + if (cpu_to_le16(checksum) == dentry->dentry.guid.checksum) + print_guid("GUID", dentry->dentry.guid.guid); + else + exfat_info("GUID is corrupted, please delete it or set a new one\n"); + + free(dentry); + + return err; +} + +int __exfat_set_volume_guid(struct exfat_dentry *dentry, const char *guid) +{ + int err; + uint16_t checksum = 0; + + memset(dentry, 0, sizeof(*dentry)); + dentry->type = EXFAT_GUID; + + err = set_guid(dentry->dentry.guid.guid, guid); + if (err) + return err; + + exfat_calc_dentry_checksum(dentry, &checksum, true); + dentry->dentry.guid.checksum = cpu_to_le16(checksum); + + return 0; +} + +/* + * Create/Update/Delete GUID dentry in root directory + * + * create/update GUID if @guid is not NULL. + * delete GUID if @guid is NULL. + */ +int exfat_set_volume_guid(struct exfat *exfat, const char *guid) +{ + struct exfat_dentry *dentry; + struct exfat_dentry_loc loc; + int err; + + struct exfat_lookup_filter filter = { + .in.type = EXFAT_GUID, + .in.dentry_count = 1, + .in.filter = NULL, + }; + + err = exfat_lookup_dentry_set(exfat, exfat->root, &filter); + if (!err) { + /* GUID entry is found */ + dentry = filter.out.dentry_set; + } else { + /* no GUID to delete */ + if (guid == NULL) + return 0; + + dentry = calloc(1, sizeof(*dentry)); + if (!dentry) + return -ENOMEM; + } + + if (guid) { + /* Set GUID */ + err = __exfat_set_volume_guid(dentry, guid); + if (err) + goto out; + } else { + /* Delete GUID */ + dentry->type &= ~EXFAT_INVAL; + } + + loc.parent = exfat->root; + loc.file_offset = filter.out.file_offset; + loc.dev_offset = filter.out.dev_offset; + err = exfat_add_dentry_set(exfat, &loc, dentry, 1, false); + if (!err) { + if (guid) + print_guid("new GUID", dentry->dentry.guid.guid); + else + exfat_info("GUID is deleted\n"); + } + +out: + free(dentry); + + return err; +} + +int exfat_read_sector(struct exfat_blk_dev *bd, void *buf, unsigned int sec_off) +{ + int ret; + unsigned long long offset = + (unsigned long long)sec_off * bd->sector_size; + + ret = pread(bd->dev_fd, buf, bd->sector_size, offset); + 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 = + (unsigned long long)sec_off * bd->sector_size; + + bytes = pwrite(bd->dev_fd, buf, bd->sector_size, offset); + 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; + } + + if (memcmp(ppbr->bpb.oem_name, "EXFAT ", 8) != 0) { + exfat_err("Bad fs_name in boot sector, which does not describe a valid exfat filesystem\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; + } + + if (memcmp(ppbr->bpb.oem_name, "EXFAT ", 8) != 0) { + exfat_err("Bad fs_name in boot sector, which does not describe a valid exfat filesystem\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; +} + +int exfat_get_next_clus(struct exfat *exfat, clus_t clus, clus_t *next) +{ + off_t offset; + + *next = EXFAT_EOF_CLUSTER; + + if (!exfat_heap_clus(exfat, clus)) + return -EINVAL; + + offset = (off_t)le32_to_cpu(exfat->bs->bsx.fat_offset) << + exfat->bs->bsx.sect_size_bits; + offset += sizeof(clus_t) * clus; + + if (exfat_read(exfat->blk_dev->dev_fd, next, sizeof(*next), offset) + != sizeof(*next)) + return -EIO; + *next = le32_to_cpu(*next); + return 0; +} + +int exfat_get_inode_next_clus(struct exfat *exfat, struct exfat_inode *node, + clus_t clus, clus_t *next) +{ + *next = EXFAT_EOF_CLUSTER; + + if (node->is_contiguous) { + if (!exfat_heap_clus(exfat, clus)) + return -EINVAL; + *next = clus + 1; + return 0; + } + + return exfat_get_next_clus(exfat, clus, next); +} + +int exfat_set_fat(struct exfat *exfat, clus_t clus, clus_t next_clus) +{ + off_t offset; + + offset = le32_to_cpu(exfat->bs->bsx.fat_offset) << + exfat->bs->bsx.sect_size_bits; + offset += sizeof(clus_t) * clus; + + if (exfat_write(exfat->blk_dev->dev_fd, &next_clus, sizeof(next_clus), + offset) != sizeof(next_clus)) + return -EIO; + return 0; +} + +off_t exfat_s2o(struct exfat *exfat, off_t sect) +{ + return sect << exfat->bs->bsx.sect_size_bits; +} + +off_t exfat_c2o(struct exfat *exfat, unsigned int clus) +{ + assert(clus >= EXFAT_FIRST_CLUSTER); + + return exfat_s2o(exfat, le32_to_cpu(exfat->bs->bsx.clu_offset) + + ((off_t)(clus - EXFAT_FIRST_CLUSTER) << + exfat->bs->bsx.sect_per_clus_bits)); +} + +int exfat_o2c(struct exfat *exfat, off_t device_offset, + unsigned int *clu, unsigned int *offset) +{ + off_t heap_offset; + + heap_offset = exfat_s2o(exfat, le32_to_cpu(exfat->bs->bsx.clu_offset)); + if (device_offset < heap_offset) + return -ERANGE; + + *clu = (unsigned int)((device_offset - heap_offset) / + exfat->clus_size) + EXFAT_FIRST_CLUSTER; + if (!exfat_heap_clus(exfat, *clu)) + return -ERANGE; + *offset = (device_offset - heap_offset) % exfat->clus_size; + return 0; +} + +bool exfat_heap_clus(struct exfat *exfat, clus_t clus) +{ + return clus >= EXFAT_FIRST_CLUSTER && + (clus - EXFAT_FIRST_CLUSTER) < exfat->clus_count; +} + +int exfat_root_clus_count(struct exfat *exfat) +{ + struct exfat_inode *node = exfat->root; + clus_t clus, next; + int clus_count = 0; + + if (!exfat_heap_clus(exfat, node->first_clus)) + return -EIO; + + clus = node->first_clus; + do { + if (exfat_bitmap_get(exfat->alloc_bitmap, clus)) + return -EINVAL; + + exfat_bitmap_set(exfat->alloc_bitmap, clus); + + if (exfat_get_inode_next_clus(exfat, node, clus, &next)) { + exfat_err("ERROR: failed to read the fat entry of root"); + return -EIO; + } + + if (next != EXFAT_EOF_CLUSTER && !exfat_heap_clus(exfat, next)) + return -EINVAL; + + clus = next; + clus_count++; + } while (clus != EXFAT_EOF_CLUSTER); + + node->size = clus_count * exfat->clus_size; + return 0; +} + +int read_boot_sect(struct exfat_blk_dev *bdev, struct pbr **bs) +{ + struct pbr *pbr; + int err = 0; + unsigned int sect_size, clu_size; + + pbr = malloc(sizeof(struct pbr)); + + if (exfat_read(bdev->dev_fd, pbr, sizeof(*pbr), 0) != + (ssize_t)sizeof(*pbr)) { + exfat_err("failed to read a boot sector\n"); + err = -EIO; + goto err; + } + + err = -EINVAL; + if (memcmp(pbr->bpb.oem_name, "EXFAT ", 8) != 0) { + exfat_err("failed to find exfat file system\n"); + goto err; + } + + sect_size = 1 << pbr->bsx.sect_size_bits; + clu_size = 1 << (pbr->bsx.sect_size_bits + + pbr->bsx.sect_per_clus_bits); + + if (sect_size < 512 || sect_size > 4 * KB) { + exfat_err("too small or big sector size: %d\n", + sect_size); + goto err; + } + + if (clu_size < sect_size || clu_size > 32 * MB) { + exfat_err("too small or big cluster size: %d\n", + clu_size); + goto err; + } + + *bs = pbr; + return 0; +err: + free(pbr); + return err; +} |