diff options
Diffstat (limited to 'roms/u-boot/fs/fat/fat.c')
| -rw-r--r-- | roms/u-boot/fs/fat/fat.c | 1368 |
1 files changed, 1368 insertions, 0 deletions
diff --git a/roms/u-boot/fs/fat/fat.c b/roms/u-boot/fs/fat/fat.c new file mode 100644 index 000000000..c561d82b3 --- /dev/null +++ b/roms/u-boot/fs/fat/fat.c @@ -0,0 +1,1368 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * fat.c + * + * R/O (V)FAT 12/16/32 filesystem implementation by Marcus Sundberg + * + * 2002-07-28 - rjones@nexus-tech.net - ported to ppcboot v1.1.6 + * 2003-03-10 - kharris@nexus-tech.net - ported to uboot + */ + +#include <common.h> +#include <blk.h> +#include <config.h> +#include <exports.h> +#include <fat.h> +#include <fs.h> +#include <log.h> +#include <asm/byteorder.h> +#include <part.h> +#include <malloc.h> +#include <memalign.h> +#include <asm/cache.h> +#include <linux/compiler.h> +#include <linux/ctype.h> + +/* + * Convert a string to lowercase. Converts at most 'len' characters, + * 'len' may be larger than the length of 'str' if 'str' is NULL + * terminated. + */ +static void downcase(char *str, size_t len) +{ + while (*str != '\0' && len--) { + *str = tolower(*str); + str++; + } +} + +static struct blk_desc *cur_dev; +static struct disk_partition cur_part_info; + +#define DOS_BOOT_MAGIC_OFFSET 0x1fe +#define DOS_FS_TYPE_OFFSET 0x36 +#define DOS_FS32_TYPE_OFFSET 0x52 + +static int disk_read(__u32 block, __u32 nr_blocks, void *buf) +{ + ulong ret; + + if (!cur_dev) + return -1; + + ret = blk_dread(cur_dev, cur_part_info.start + block, nr_blocks, buf); + + if (ret != nr_blocks) + return -1; + + return ret; +} + +int fat_set_blk_dev(struct blk_desc *dev_desc, struct disk_partition *info) +{ + ALLOC_CACHE_ALIGN_BUFFER(unsigned char, buffer, dev_desc->blksz); + + cur_dev = dev_desc; + cur_part_info = *info; + + /* Make sure it has a valid FAT header */ + if (disk_read(0, 1, buffer) != 1) { + cur_dev = NULL; + return -1; + } + + /* Check if it's actually a DOS volume */ + if (memcmp(buffer + DOS_BOOT_MAGIC_OFFSET, "\x55\xAA", 2)) { + cur_dev = NULL; + return -1; + } + + /* Check for FAT12/FAT16/FAT32 filesystem */ + if (!memcmp(buffer + DOS_FS_TYPE_OFFSET, "FAT", 3)) + return 0; + if (!memcmp(buffer + DOS_FS32_TYPE_OFFSET, "FAT32", 5)) + return 0; + + cur_dev = NULL; + return -1; +} + +int fat_register_device(struct blk_desc *dev_desc, int part_no) +{ + struct disk_partition info; + + /* First close any currently found FAT filesystem */ + cur_dev = NULL; + + /* Read the partition table, if present */ + if (part_get_info(dev_desc, part_no, &info)) { + if (part_no != 0) { + printf("** Partition %d not valid on device %d **\n", + part_no, dev_desc->devnum); + return -1; + } + + info.start = 0; + info.size = dev_desc->lba; + info.blksz = dev_desc->blksz; + info.name[0] = 0; + info.type[0] = 0; + info.bootable = 0; +#if CONFIG_IS_ENABLED(PARTITION_UUIDS) + info.uuid[0] = 0; +#endif + } + + return fat_set_blk_dev(dev_desc, &info); +} + +/* + * Extract zero terminated short name from a directory entry. + */ +static void get_name(dir_entry *dirent, char *s_name) +{ + char *ptr; + + memcpy(s_name, dirent->nameext.name, 8); + s_name[8] = '\0'; + ptr = s_name; + while (*ptr && *ptr != ' ') + ptr++; + if (dirent->lcase & CASE_LOWER_BASE) + downcase(s_name, (unsigned)(ptr - s_name)); + if (dirent->nameext.ext[0] && dirent->nameext.ext[0] != ' ') { + *ptr++ = '.'; + memcpy(ptr, dirent->nameext.ext, 3); + if (dirent->lcase & CASE_LOWER_EXT) + downcase(ptr, 3); + ptr[3] = '\0'; + while (*ptr && *ptr != ' ') + ptr++; + } + *ptr = '\0'; + if (*s_name == DELETED_FLAG) + *s_name = '\0'; + else if (*s_name == aRING) + *s_name = DELETED_FLAG; +} + +static int flush_dirty_fat_buffer(fsdata *mydata); + +#if !CONFIG_IS_ENABLED(FAT_WRITE) +/* Stub for read only operation */ +int flush_dirty_fat_buffer(fsdata *mydata) +{ + (void)(mydata); + return 0; +} +#endif + +/* + * Get the entry at index 'entry' in a FAT (12/16/32) table. + * On failure 0x00 is returned. + */ +static __u32 get_fatent(fsdata *mydata, __u32 entry) +{ + __u32 bufnum; + __u32 offset, off8; + __u32 ret = 0x00; + + if (CHECK_CLUST(entry, mydata->fatsize)) { + printf("Error: Invalid FAT entry: 0x%08x\n", entry); + return ret; + } + + switch (mydata->fatsize) { + case 32: + bufnum = entry / FAT32BUFSIZE; + offset = entry - bufnum * FAT32BUFSIZE; + break; + case 16: + bufnum = entry / FAT16BUFSIZE; + offset = entry - bufnum * FAT16BUFSIZE; + break; + case 12: + bufnum = entry / FAT12BUFSIZE; + offset = entry - bufnum * FAT12BUFSIZE; + break; + + default: + /* Unsupported FAT size */ + return ret; + } + + debug("FAT%d: entry: 0x%08x = %d, offset: 0x%04x = %d\n", + mydata->fatsize, entry, entry, offset, offset); + + /* Read a new block of FAT entries into the cache. */ + if (bufnum != mydata->fatbufnum) { + __u32 getsize = FATBUFBLOCKS; + __u8 *bufptr = mydata->fatbuf; + __u32 fatlength = mydata->fatlength; + __u32 startblock = bufnum * FATBUFBLOCKS; + + /* Cap length if fatlength is not a multiple of FATBUFBLOCKS */ + if (startblock + getsize > fatlength) + getsize = fatlength - startblock; + + startblock += mydata->fat_sect; /* Offset from start of disk */ + + /* Write back the fatbuf to the disk */ + if (flush_dirty_fat_buffer(mydata) < 0) + return -1; + + if (disk_read(startblock, getsize, bufptr) < 0) { + debug("Error reading FAT blocks\n"); + return ret; + } + mydata->fatbufnum = bufnum; + } + + /* Get the actual entry from the table */ + switch (mydata->fatsize) { + case 32: + ret = FAT2CPU32(((__u32 *) mydata->fatbuf)[offset]); + break; + case 16: + ret = FAT2CPU16(((__u16 *) mydata->fatbuf)[offset]); + break; + case 12: + off8 = (offset * 3) / 2; + /* fatbut + off8 may be unaligned, read in byte granularity */ + ret = mydata->fatbuf[off8] + (mydata->fatbuf[off8 + 1] << 8); + + if (offset & 0x1) + ret >>= 4; + ret &= 0xfff; + } + debug("FAT%d: ret: 0x%08x, entry: 0x%08x, offset: 0x%04x\n", + mydata->fatsize, ret, entry, offset); + + return ret; +} + +/* + * Read at most 'size' bytes from the specified cluster into 'buffer'. + * Return 0 on success, -1 otherwise. + */ +static int +get_cluster(fsdata *mydata, __u32 clustnum, __u8 *buffer, unsigned long size) +{ + __u32 startsect; + int ret; + + if (clustnum > 0) { + startsect = clust_to_sect(mydata, clustnum); + } else { + startsect = mydata->rootdir_sect; + } + + debug("gc - clustnum: %d, startsect: %d\n", clustnum, startsect); + + if ((unsigned long)buffer & (ARCH_DMA_MINALIGN - 1)) { + ALLOC_CACHE_ALIGN_BUFFER(__u8, tmpbuf, mydata->sect_size); + + debug("FAT: Misaligned buffer address (%p)\n", buffer); + + while (size >= mydata->sect_size) { + ret = disk_read(startsect++, 1, tmpbuf); + if (ret != 1) { + debug("Error reading data (got %d)\n", ret); + return -1; + } + + memcpy(buffer, tmpbuf, mydata->sect_size); + buffer += mydata->sect_size; + size -= mydata->sect_size; + } + } else { + __u32 idx; + + idx = size / mydata->sect_size; + if (idx == 0) + ret = 0; + else + ret = disk_read(startsect, idx, buffer); + if (ret != idx) { + debug("Error reading data (got %d)\n", ret); + return -1; + } + startsect += idx; + idx *= mydata->sect_size; + buffer += idx; + size -= idx; + } + if (size) { + ALLOC_CACHE_ALIGN_BUFFER(__u8, tmpbuf, mydata->sect_size); + + ret = disk_read(startsect, 1, tmpbuf); + if (ret != 1) { + debug("Error reading data (got %d)\n", ret); + return -1; + } + + memcpy(buffer, tmpbuf, size); + } + + return 0; +} + +/** + * get_contents() - read from file + * + * Read at most 'maxsize' bytes from 'pos' in the file associated with 'dentptr' + * into 'buffer'. Update the number of bytes read in *gotsize or return -1 on + * fatal errors. + * + * @mydata: file system description + * @dentprt: directory entry pointer + * @pos: position from where to read + * @buffer: buffer into which to read + * @maxsize: maximum number of bytes to read + * @gotsize: number of bytes actually read + * Return: -1 on error, otherwise 0 + */ +static int get_contents(fsdata *mydata, dir_entry *dentptr, loff_t pos, + __u8 *buffer, loff_t maxsize, loff_t *gotsize) +{ + loff_t filesize = FAT2CPU32(dentptr->size); + unsigned int bytesperclust = mydata->clust_size * mydata->sect_size; + __u32 curclust = START(dentptr); + __u32 endclust, newclust; + loff_t actsize; + + *gotsize = 0; + debug("Filesize: %llu bytes\n", filesize); + + if (pos >= filesize) { + debug("Read position past EOF: %llu\n", pos); + return 0; + } + + if (maxsize > 0 && filesize > pos + maxsize) + filesize = pos + maxsize; + + debug("%llu bytes\n", filesize); + + actsize = bytesperclust; + + /* go to cluster at pos */ + while (actsize <= pos) { + curclust = get_fatent(mydata, curclust); + if (CHECK_CLUST(curclust, mydata->fatsize)) { + debug("curclust: 0x%x\n", curclust); + printf("Invalid FAT entry\n"); + return -1; + } + actsize += bytesperclust; + } + + /* actsize > pos */ + actsize -= bytesperclust; + filesize -= actsize; + pos -= actsize; + + /* align to beginning of next cluster if any */ + if (pos) { + __u8 *tmp_buffer; + + actsize = min(filesize, (loff_t)bytesperclust); + tmp_buffer = malloc_cache_aligned(actsize); + if (!tmp_buffer) { + debug("Error: allocating buffer\n"); + return -1; + } + + if (get_cluster(mydata, curclust, tmp_buffer, actsize) != 0) { + printf("Error reading cluster\n"); + free(tmp_buffer); + return -1; + } + filesize -= actsize; + actsize -= pos; + memcpy(buffer, tmp_buffer + pos, actsize); + free(tmp_buffer); + *gotsize += actsize; + if (!filesize) + return 0; + buffer += actsize; + + curclust = get_fatent(mydata, curclust); + if (CHECK_CLUST(curclust, mydata->fatsize)) { + debug("curclust: 0x%x\n", curclust); + printf("Invalid FAT entry\n"); + return -1; + } + } + + actsize = bytesperclust; + endclust = curclust; + + do { + /* search for consecutive clusters */ + while (actsize < filesize) { + newclust = get_fatent(mydata, endclust); + if ((newclust - 1) != endclust) + goto getit; + if (CHECK_CLUST(newclust, mydata->fatsize)) { + debug("curclust: 0x%x\n", newclust); + printf("Invalid FAT entry\n"); + return -1; + } + endclust = newclust; + actsize += bytesperclust; + } + + /* get remaining bytes */ + actsize = filesize; + if (get_cluster(mydata, curclust, buffer, (int)actsize) != 0) { + printf("Error reading cluster\n"); + return -1; + } + *gotsize += actsize; + return 0; +getit: + if (get_cluster(mydata, curclust, buffer, (int)actsize) != 0) { + printf("Error reading cluster\n"); + return -1; + } + *gotsize += (int)actsize; + filesize -= actsize; + buffer += actsize; + + curclust = get_fatent(mydata, endclust); + if (CHECK_CLUST(curclust, mydata->fatsize)) { + debug("curclust: 0x%x\n", curclust); + printf("Invalid FAT entry\n"); + return -1; + } + actsize = bytesperclust; + endclust = curclust; + } while (1); +} + +/* + * Extract the file name information from 'slotptr' into 'l_name', + * starting at l_name[*idx]. + * Return 1 if terminator (zero byte) is found, 0 otherwise. + */ +static int slot2str(dir_slot *slotptr, char *l_name, int *idx) +{ + int j; + + for (j = 0; j <= 8; j += 2) { + l_name[*idx] = slotptr->name0_4[j]; + if (l_name[*idx] == 0x00) + return 1; + (*idx)++; + } + for (j = 0; j <= 10; j += 2) { + l_name[*idx] = slotptr->name5_10[j]; + if (l_name[*idx] == 0x00) + return 1; + (*idx)++; + } + for (j = 0; j <= 2; j += 2) { + l_name[*idx] = slotptr->name11_12[j]; + if (l_name[*idx] == 0x00) + return 1; + (*idx)++; + } + + return 0; +} + +/* Calculate short name checksum */ +static __u8 mkcksum(struct nameext *nameext) +{ + int i; + u8 *pos = (void *)nameext; + + __u8 ret = 0; + + for (i = 0; i < 11; i++) + ret = (((ret & 1) << 7) | ((ret & 0xfe) >> 1)) + pos[i]; + + return ret; +} + +/* + * Read boot sector and volume info from a FAT filesystem + */ +static int +read_bootsectandvi(boot_sector *bs, volume_info *volinfo, int *fatsize) +{ + __u8 *block; + volume_info *vistart; + int ret = 0; + + if (cur_dev == NULL) { + debug("Error: no device selected\n"); + return -1; + } + + block = malloc_cache_aligned(cur_dev->blksz); + if (block == NULL) { + debug("Error: allocating block\n"); + return -1; + } + + if (disk_read(0, 1, block) < 0) { + debug("Error: reading block\n"); + goto fail; + } + + memcpy(bs, block, sizeof(boot_sector)); + bs->reserved = FAT2CPU16(bs->reserved); + bs->fat_length = FAT2CPU16(bs->fat_length); + bs->secs_track = FAT2CPU16(bs->secs_track); + bs->heads = FAT2CPU16(bs->heads); + bs->total_sect = FAT2CPU32(bs->total_sect); + + /* FAT32 entries */ + if (bs->fat_length == 0) { + /* Assume FAT32 */ + bs->fat32_length = FAT2CPU32(bs->fat32_length); + bs->flags = FAT2CPU16(bs->flags); + bs->root_cluster = FAT2CPU32(bs->root_cluster); + bs->info_sector = FAT2CPU16(bs->info_sector); + bs->backup_boot = FAT2CPU16(bs->backup_boot); + vistart = (volume_info *)(block + sizeof(boot_sector)); + *fatsize = 32; + } else { + vistart = (volume_info *)&(bs->fat32_length); + *fatsize = 0; + } + memcpy(volinfo, vistart, sizeof(volume_info)); + + if (*fatsize == 32) { + if (strncmp(FAT32_SIGN, vistart->fs_type, SIGNLEN) == 0) + goto exit; + } else { + if (strncmp(FAT12_SIGN, vistart->fs_type, SIGNLEN) == 0) { + *fatsize = 12; + goto exit; + } + if (strncmp(FAT16_SIGN, vistart->fs_type, SIGNLEN) == 0) { + *fatsize = 16; + goto exit; + } + } + + debug("Error: broken fs_type sign\n"); +fail: + ret = -1; +exit: + free(block); + return ret; +} + +static int get_fs_info(fsdata *mydata) +{ + boot_sector bs; + volume_info volinfo; + int ret; + + ret = read_bootsectandvi(&bs, &volinfo, &mydata->fatsize); + if (ret) { + debug("Error: reading boot sector\n"); + return ret; + } + + if (mydata->fatsize == 32) { + mydata->fatlength = bs.fat32_length; + mydata->total_sect = bs.total_sect; + } else { + mydata->fatlength = bs.fat_length; + mydata->total_sect = (bs.sectors[1] << 8) + bs.sectors[0]; + if (!mydata->total_sect) + mydata->total_sect = bs.total_sect; + } + if (!mydata->total_sect) /* unlikely */ + mydata->total_sect = (u32)cur_part_info.size; + + mydata->fats = bs.fats; + mydata->fat_sect = bs.reserved; + + mydata->rootdir_sect = mydata->fat_sect + mydata->fatlength * bs.fats; + + mydata->sect_size = (bs.sector_size[1] << 8) + bs.sector_size[0]; + mydata->clust_size = bs.cluster_size; + if (mydata->sect_size != cur_part_info.blksz) { + printf("Error: FAT sector size mismatch (fs=%hu, dev=%lu)\n", + mydata->sect_size, cur_part_info.blksz); + return -1; + } + if (mydata->clust_size == 0) { + printf("Error: FAT cluster size not set\n"); + return -1; + } + if ((unsigned int)mydata->clust_size * mydata->sect_size > + MAX_CLUSTSIZE) { + printf("Error: FAT cluster size too big (cs=%u, max=%u)\n", + (unsigned int)mydata->clust_size * mydata->sect_size, + MAX_CLUSTSIZE); + return -1; + } + + if (mydata->fatsize == 32) { + mydata->data_begin = mydata->rootdir_sect - + (mydata->clust_size * 2); + mydata->root_cluster = bs.root_cluster; + } else { + mydata->rootdir_size = ((bs.dir_entries[1] * (int)256 + + bs.dir_entries[0]) * + sizeof(dir_entry)) / + mydata->sect_size; + mydata->data_begin = mydata->rootdir_sect + + mydata->rootdir_size - + (mydata->clust_size * 2); + + /* + * The root directory is not cluster-aligned and may be on a + * "negative" cluster, this will be handled specially in + * fat_next_cluster(). + */ + mydata->root_cluster = 0; + } + + mydata->fatbufnum = -1; + mydata->fat_dirty = 0; + mydata->fatbuf = malloc_cache_aligned(FATBUFSIZE); + if (mydata->fatbuf == NULL) { + debug("Error: allocating memory\n"); + return -1; + } + + debug("FAT%d, fat_sect: %d, fatlength: %d\n", + mydata->fatsize, mydata->fat_sect, mydata->fatlength); + debug("Rootdir begins at cluster: %d, sector: %d, offset: %x\n" + "Data begins at: %d\n", + mydata->root_cluster, + mydata->rootdir_sect, + mydata->rootdir_sect * mydata->sect_size, mydata->data_begin); + debug("Sector size: %d, cluster size: %d\n", mydata->sect_size, + mydata->clust_size); + + return 0; +} + +/** + * struct fat_itr - directory iterator, to simplify filesystem traversal + * + * Implements an iterator pattern to traverse directory tables, + * transparently handling directory tables split across multiple + * clusters, and the difference between FAT12/FAT16 root directory + * (contiguous) and subdirectories + FAT32 root (chained). + * + * Rough usage + * + * .. code-block:: c + * + * for (fat_itr_root(&itr, fsdata); fat_itr_next(&itr); ) { + * // to traverse down to a subdirectory pointed to by + * // current iterator position: + * fat_itr_child(&itr, &itr); + * } + * + * For a more complete example, see fat_itr_resolve(). + */ +struct fat_itr { + /** + * @fsdata: filesystem parameters + */ + fsdata *fsdata; + /** + * @start_clust: first cluster + */ + unsigned int start_clust; + /** + * @clust: current cluster + */ + unsigned int clust; + /** + * @next_clust: next cluster if remaining == 0 + */ + unsigned int next_clust; + /** + * @last_cluster: set if last cluster of directory reached + */ + int last_cluster; + /** + * @is_root: is iterator at root directory + */ + int is_root; + /** + * @remaining: remaining directory entries in current cluster + */ + int remaining; + /** + * @dent: current directory entry + */ + dir_entry *dent; + /** + * @dent_rem: remaining entries after long name start + */ + int dent_rem; + /** + * @dent_clust: cluster of long name start + */ + unsigned int dent_clust; + /** + * @dent_start: first directory entry for long name + */ + dir_entry *dent_start; + /** + * @l_name: long name of current directory entry + */ + char l_name[VFAT_MAXLEN_BYTES]; + /** + * @s_name: short 8.3 name of current directory entry + */ + char s_name[14]; + /** + * @name: l_name if there is one, else s_name + */ + char *name; + /** + * @block: buffer for current cluster + */ + u8 block[MAX_CLUSTSIZE] __aligned(ARCH_DMA_MINALIGN); +}; + +static int fat_itr_isdir(fat_itr *itr); + +/** + * fat_itr_root() - initialize an iterator to start at the root + * directory + * + * @itr: iterator to initialize + * @fsdata: filesystem data for the partition + * @return 0 on success, else -errno + */ +static int fat_itr_root(fat_itr *itr, fsdata *fsdata) +{ + if (get_fs_info(fsdata)) + return -ENXIO; + + itr->fsdata = fsdata; + itr->start_clust = fsdata->root_cluster; + itr->clust = fsdata->root_cluster; + itr->next_clust = fsdata->root_cluster; + itr->dent = NULL; + itr->remaining = 0; + itr->last_cluster = 0; + itr->is_root = 1; + + return 0; +} + +/** + * fat_itr_child() - initialize an iterator to descend into a sub- + * directory + * + * Initializes 'itr' to iterate the contents of the directory at + * the current cursor position of 'parent'. It is an error to + * call this if the current cursor of 'parent' is pointing at a + * regular file. + * + * Note that 'itr' and 'parent' can be the same pointer if you do + * not need to preserve 'parent' after this call, which is useful + * for traversing directory structure to resolve a file/directory. + * + * @itr: iterator to initialize + * @parent: the iterator pointing at a directory entry in the + * parent directory of the directory to iterate + */ +static void fat_itr_child(fat_itr *itr, fat_itr *parent) +{ + fsdata *mydata = parent->fsdata; /* for silly macros */ + unsigned clustnum = START(parent->dent); + + assert(fat_itr_isdir(parent)); + + itr->fsdata = parent->fsdata; + itr->start_clust = clustnum; + if (clustnum > 0) { + itr->clust = clustnum; + itr->next_clust = clustnum; + itr->is_root = 0; + } else { + itr->clust = parent->fsdata->root_cluster; + itr->next_clust = parent->fsdata->root_cluster; + itr->start_clust = parent->fsdata->root_cluster; + itr->is_root = 1; + } + itr->dent = NULL; + itr->remaining = 0; + itr->last_cluster = 0; +} + +/** + * fat_next_cluster() - load next FAT cluster + * + * The function is used when iterating through directories. It loads the + * next cluster with directory entries + * + * @itr: directory iterator + * @nbytes: number of bytes read, 0 on error + * Return: first directory entry, NULL on error + */ +void *fat_next_cluster(fat_itr *itr, unsigned int *nbytes) +{ + int ret; + u32 sect; + u32 read_size; + + /* have we reached the end? */ + if (itr->last_cluster) + return NULL; + + if (itr->is_root && itr->fsdata->fatsize != 32) { + /* + * The root directory is located before the data area and + * cannot be indexed using the regular unsigned cluster + * numbers (it may start at a "negative" cluster or not at a + * cluster boundary at all), so consider itr->next_clust to be + * a offset in cluster-sized units from the start of rootdir. + */ + unsigned sect_offset = itr->next_clust * itr->fsdata->clust_size; + unsigned remaining_sects = itr->fsdata->rootdir_size - sect_offset; + sect = itr->fsdata->rootdir_sect + sect_offset; + /* do not read past the end of rootdir */ + read_size = min_t(u32, itr->fsdata->clust_size, + remaining_sects); + } else { + sect = clust_to_sect(itr->fsdata, itr->next_clust); + read_size = itr->fsdata->clust_size; + } + + log_debug("FAT read(sect=%d), clust_size=%d, read_size=%u\n", + sect, itr->fsdata->clust_size, read_size); + + /* + * NOTE: do_fat_read_at() had complicated logic to deal w/ + * vfat names that span multiple clusters in the fat16 case, + * which get_dentfromdir() probably also needed (and was + * missing). And not entirely sure what fat32 didn't have + * the same issue.. We solve that by only caring about one + * dent at a time and iteratively constructing the vfat long + * name. + */ + ret = disk_read(sect, read_size, itr->block); + if (ret < 0) { + debug("Error: reading block\n"); + return NULL; + } + + *nbytes = read_size * itr->fsdata->sect_size; + itr->clust = itr->next_clust; + if (itr->is_root && itr->fsdata->fatsize != 32) { + itr->next_clust++; + if (itr->next_clust * itr->fsdata->clust_size >= + itr->fsdata->rootdir_size) { + debug("nextclust: 0x%x\n", itr->next_clust); + itr->last_cluster = 1; + } + } else { + itr->next_clust = get_fatent(itr->fsdata, itr->next_clust); + if (CHECK_CLUST(itr->next_clust, itr->fsdata->fatsize)) { + debug("nextclust: 0x%x\n", itr->next_clust); + itr->last_cluster = 1; + } + } + + return itr->block; +} + +static dir_entry *next_dent(fat_itr *itr) +{ + if (itr->remaining == 0) { + unsigned nbytes; + struct dir_entry *dent = fat_next_cluster(itr, &nbytes); + + /* have we reached the last cluster? */ + if (!dent) { + /* a sign for no more entries left */ + itr->dent = NULL; + return NULL; + } + + itr->remaining = nbytes / sizeof(dir_entry) - 1; + itr->dent = dent; + } else { + itr->remaining--; + itr->dent++; + } + + /* have we reached the last valid entry? */ + if (itr->dent->nameext.name[0] == 0) + return NULL; + + return itr->dent; +} + +static dir_entry *extract_vfat_name(fat_itr *itr) +{ + struct dir_entry *dent = itr->dent; + int seqn = itr->dent->nameext.name[0] & ~LAST_LONG_ENTRY_MASK; + u8 chksum, alias_checksum = ((dir_slot *)dent)->alias_checksum; + int n = 0; + + while (seqn--) { + char buf[13]; + int idx = 0; + + slot2str((dir_slot *)dent, buf, &idx); + + if (n + idx >= sizeof(itr->l_name)) + return NULL; + + /* shift accumulated long-name up and copy new part in: */ + memmove(itr->l_name + idx, itr->l_name, n); + memcpy(itr->l_name, buf, idx); + n += idx; + + dent = next_dent(itr); + if (!dent) + return NULL; + } + + /* + * We are now at the short file name entry. + * If it is marked as deleted, just skip it. + */ + if (dent->nameext.name[0] == DELETED_FLAG || + dent->nameext.name[0] == aRING) + return NULL; + + itr->l_name[n] = '\0'; + + chksum = mkcksum(&dent->nameext); + + /* checksum mismatch could mean deleted file, etc.. skip it: */ + if (chksum != alias_checksum) { + debug("** chksum=%x, alias_checksum=%x, l_name=%s, s_name=%8s.%3s\n", + chksum, alias_checksum, itr->l_name, dent->nameext.name, + dent->nameext.ext); + return NULL; + } + + return dent; +} + +/** + * fat_itr_next() - step to the next entry in a directory + * + * Must be called once on a new iterator before the cursor is valid. + * + * @itr: the iterator to iterate + * @return boolean, 1 if success or 0 if no more entries in the + * current directory + */ +static int fat_itr_next(fat_itr *itr) +{ + dir_entry *dent; + + itr->name = NULL; + + /* + * One logical directory entry consist of following slots: + * name[0] Attributes + * dent[N - N]: LFN[N - 1] N|0x40 ATTR_VFAT + * ... + * dent[N - 2]: LFN[1] 2 ATTR_VFAT + * dent[N - 1]: LFN[0] 1 ATTR_VFAT + * dent[N]: SFN ATTR_ARCH + */ + + while (1) { + dent = next_dent(itr); + if (!dent) { + itr->dent_start = NULL; + return 0; + } + itr->dent_rem = itr->remaining; + itr->dent_start = itr->dent; + itr->dent_clust = itr->clust; + if (dent->nameext.name[0] == DELETED_FLAG) + continue; + + if (dent->attr & ATTR_VOLUME) { + if ((dent->attr & ATTR_VFAT) == ATTR_VFAT && + (dent->nameext.name[0] & LAST_LONG_ENTRY_MASK)) { + /* long file name */ + dent = extract_vfat_name(itr); + /* + * If succeeded, dent has a valid short file + * name entry for the current entry. + * If failed, itr points to a current bogus + * entry. So after fetching a next one, + * it may have a short file name entry + * for this bogus entry so that we can still + * check for a short name. + */ + if (!dent) + continue; + itr->name = itr->l_name; + break; + } else { + /* Volume label or VFAT entry, skip */ + continue; + } + } + + /* short file name */ + break; + } + + get_name(dent, itr->s_name); + if (!itr->name) + itr->name = itr->s_name; + + return 1; +} + +/** + * fat_itr_isdir() - is current cursor position pointing to a directory + * + * @itr: the iterator + * @return true if cursor is at a directory + */ +static int fat_itr_isdir(fat_itr *itr) +{ + return !!(itr->dent->attr & ATTR_DIR); +} + +/* + * Helpers: + */ + +#define TYPE_FILE 0x1 +#define TYPE_DIR 0x2 +#define TYPE_ANY (TYPE_FILE | TYPE_DIR) + +/** + * fat_itr_resolve() - traverse directory structure to resolve the + * requested path. + * + * Traverse directory structure to the requested path. If the specified + * path is to a directory, this will descend into the directory and + * leave it iterator at the start of the directory. If the path is to a + * file, it will leave the iterator in the parent directory with current + * cursor at file's entry in the directory. + * + * @itr: iterator initialized to root + * @path: the requested path + * @type: bitmask of allowable file types + * @return 0 on success or -errno + */ +static int fat_itr_resolve(fat_itr *itr, const char *path, unsigned type) +{ + const char *next; + + /* chomp any extra leading slashes: */ + while (path[0] && ISDIRDELIM(path[0])) + path++; + + /* are we at the end? */ + if (strlen(path) == 0) { + if (!(type & TYPE_DIR)) + return -ENOENT; + return 0; + } + + /* find length of next path entry: */ + next = path; + while (next[0] && !ISDIRDELIM(next[0])) + next++; + + if (itr->is_root) { + /* root dir doesn't have "." nor ".." */ + if ((((next - path) == 1) && !strncmp(path, ".", 1)) || + (((next - path) == 2) && !strncmp(path, "..", 2))) { + /* point back to itself */ + itr->clust = itr->fsdata->root_cluster; + itr->next_clust = itr->fsdata->root_cluster; + itr->start_clust = itr->fsdata->root_cluster; + itr->dent = NULL; + itr->remaining = 0; + itr->last_cluster = 0; + + if (next[0] == 0) { + if (type & TYPE_DIR) + return 0; + else + return -ENOENT; + } + + return fat_itr_resolve(itr, next, type); + } + } + + while (fat_itr_next(itr)) { + int match = 0; + unsigned n = max(strlen(itr->name), (size_t)(next - path)); + + /* check both long and short name: */ + if (!strncasecmp(path, itr->name, n)) + match = 1; + else if (itr->name != itr->s_name && + !strncasecmp(path, itr->s_name, n)) + match = 1; + + if (!match) + continue; + + if (fat_itr_isdir(itr)) { + /* recurse into directory: */ + fat_itr_child(itr, itr); + return fat_itr_resolve(itr, next, type); + } else if (next[0]) { + /* + * If next is not empty then we have a case + * like: /path/to/realfile/nonsense + */ + debug("bad trailing path: %s\n", next); + return -ENOENT; + } else if (!(type & TYPE_FILE)) { + return -ENOTDIR; + } else { + return 0; + } + } + + return -ENOENT; +} + +int file_fat_detectfs(void) +{ + boot_sector bs; + volume_info volinfo; + int fatsize; + char vol_label[12]; + + if (cur_dev == NULL) { + printf("No current device\n"); + return 1; + } + + if (IS_ENABLED(CONFIG_HAVE_BLOCK_DEVICE)) { + printf("Interface: %s\n", blk_get_if_type_name(cur_dev->if_type)); + printf(" Device %d: ", cur_dev->devnum); + dev_print(cur_dev); + } + + if (read_bootsectandvi(&bs, &volinfo, &fatsize)) { + printf("\nNo valid FAT fs found\n"); + return 1; + } + + memcpy(vol_label, volinfo.volume_label, 11); + vol_label[11] = '\0'; + volinfo.fs_type[5] = '\0'; + + printf("Filesystem: %s \"%s\"\n", volinfo.fs_type, vol_label); + + return 0; +} + +int fat_exists(const char *filename) +{ + fsdata fsdata; + fat_itr *itr; + int ret; + + itr = malloc_cache_aligned(sizeof(fat_itr)); + if (!itr) + return 0; + ret = fat_itr_root(itr, &fsdata); + if (ret) + goto out; + + ret = fat_itr_resolve(itr, filename, TYPE_ANY); + free(fsdata.fatbuf); +out: + free(itr); + return ret == 0; +} + +int fat_size(const char *filename, loff_t *size) +{ + fsdata fsdata; + fat_itr *itr; + int ret; + + itr = malloc_cache_aligned(sizeof(fat_itr)); + if (!itr) + return -ENOMEM; + ret = fat_itr_root(itr, &fsdata); + if (ret) + goto out_free_itr; + + ret = fat_itr_resolve(itr, filename, TYPE_FILE); + if (ret) { + /* + * Directories don't have size, but fs_size() is not + * expected to fail if passed a directory path: + */ + free(fsdata.fatbuf); + ret = fat_itr_root(itr, &fsdata); + if (ret) + goto out_free_itr; + ret = fat_itr_resolve(itr, filename, TYPE_DIR); + if (!ret) + *size = 0; + goto out_free_both; + } + + *size = FAT2CPU32(itr->dent->size); +out_free_both: + free(fsdata.fatbuf); +out_free_itr: + free(itr); + return ret; +} + +int file_fat_read_at(const char *filename, loff_t pos, void *buffer, + loff_t maxsize, loff_t *actread) +{ + fsdata fsdata; + fat_itr *itr; + int ret; + + itr = malloc_cache_aligned(sizeof(fat_itr)); + if (!itr) + return -ENOMEM; + ret = fat_itr_root(itr, &fsdata); + if (ret) + goto out_free_itr; + + ret = fat_itr_resolve(itr, filename, TYPE_FILE); + if (ret) + goto out_free_both; + + debug("reading %s at pos %llu\n", filename, pos); + + /* For saving default max clustersize memory allocated to malloc pool */ + dir_entry *dentptr = itr->dent; + + ret = get_contents(&fsdata, dentptr, pos, buffer, maxsize, actread); + +out_free_both: + free(fsdata.fatbuf); +out_free_itr: + free(itr); + return ret; +} + +int file_fat_read(const char *filename, void *buffer, int maxsize) +{ + loff_t actread; + int ret; + + ret = file_fat_read_at(filename, 0, buffer, maxsize, &actread); + if (ret) + return ret; + else + return actread; +} + +int fat_read_file(const char *filename, void *buf, loff_t offset, loff_t len, + loff_t *actread) +{ + int ret; + + ret = file_fat_read_at(filename, offset, buf, len, actread); + if (ret) + printf("** Unable to read file %s **\n", filename); + + return ret; +} + +typedef struct { + struct fs_dir_stream parent; + struct fs_dirent dirent; + fsdata fsdata; + fat_itr itr; +} fat_dir; + +int fat_opendir(const char *filename, struct fs_dir_stream **dirsp) +{ + fat_dir *dir; + int ret; + + dir = malloc_cache_aligned(sizeof(*dir)); + if (!dir) + return -ENOMEM; + memset(dir, 0, sizeof(*dir)); + + ret = fat_itr_root(&dir->itr, &dir->fsdata); + if (ret) + goto fail_free_dir; + + ret = fat_itr_resolve(&dir->itr, filename, TYPE_DIR); + if (ret) + goto fail_free_both; + + *dirsp = (struct fs_dir_stream *)dir; + return 0; + +fail_free_both: + free(dir->fsdata.fatbuf); +fail_free_dir: + free(dir); + return ret; +} + +int fat_readdir(struct fs_dir_stream *dirs, struct fs_dirent **dentp) +{ + fat_dir *dir = (fat_dir *)dirs; + struct fs_dirent *dent = &dir->dirent; + + if (!fat_itr_next(&dir->itr)) + return -ENOENT; + + memset(dent, 0, sizeof(*dent)); + strcpy(dent->name, dir->itr.name); + + if (fat_itr_isdir(&dir->itr)) { + dent->type = FS_DT_DIR; + } else { + dent->type = FS_DT_REG; + dent->size = FAT2CPU32(dir->itr.dent->size); + } + + *dentp = dent; + + return 0; +} + +void fat_closedir(struct fs_dir_stream *dirs) +{ + fat_dir *dir = (fat_dir *)dirs; + free(dir->fsdata.fatbuf); + free(dir); +} + +void fat_close(void) +{ +} + +int fat_uuid(char *uuid_str) +{ + boot_sector bs; + volume_info volinfo; + int fatsize; + int ret; + u8 *id; + + ret = read_bootsectandvi(&bs, &volinfo, &fatsize); + if (ret) + return ret; + + id = volinfo.volume_id; + sprintf(uuid_str, "%02X%02X-%02X%02X", id[3], id[2], id[1], id[0]); + + return 0; +} |