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![Heinrich Schuchardt](/assets/img/avatar_default.png)
The FAT driver supports unaligned reads and writes and EFI applications will make use of these. So a misaligned buffer is only worth a debug message. Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de> Signed-off-by: Alexander Graf <agraf@suse.de>
1231 lines
28 KiB
C
1231 lines
28 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* fat.c
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*
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* R/O (V)FAT 12/16/32 filesystem implementation by Marcus Sundberg
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*
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* 2002-07-28 - rjones@nexus-tech.net - ported to ppcboot v1.1.6
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* 2003-03-10 - kharris@nexus-tech.net - ported to uboot
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*/
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#include <common.h>
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#include <blk.h>
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#include <config.h>
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#include <exports.h>
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#include <fat.h>
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#include <fs.h>
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#include <asm/byteorder.h>
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#include <part.h>
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#include <malloc.h>
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#include <memalign.h>
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#include <linux/compiler.h>
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#include <linux/ctype.h>
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/*
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* Convert a string to lowercase. Converts at most 'len' characters,
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* 'len' may be larger than the length of 'str' if 'str' is NULL
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* terminated.
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*/
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static void downcase(char *str, size_t len)
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{
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while (*str != '\0' && len--) {
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*str = tolower(*str);
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str++;
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}
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}
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static struct blk_desc *cur_dev;
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static disk_partition_t cur_part_info;
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#define DOS_BOOT_MAGIC_OFFSET 0x1fe
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#define DOS_FS_TYPE_OFFSET 0x36
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#define DOS_FS32_TYPE_OFFSET 0x52
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static int disk_read(__u32 block, __u32 nr_blocks, void *buf)
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{
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ulong ret;
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if (!cur_dev)
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return -1;
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ret = blk_dread(cur_dev, cur_part_info.start + block, nr_blocks, buf);
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if (ret != nr_blocks)
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return -1;
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return ret;
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}
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int fat_set_blk_dev(struct blk_desc *dev_desc, disk_partition_t *info)
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{
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ALLOC_CACHE_ALIGN_BUFFER(unsigned char, buffer, dev_desc->blksz);
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cur_dev = dev_desc;
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cur_part_info = *info;
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/* Make sure it has a valid FAT header */
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if (disk_read(0, 1, buffer) != 1) {
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cur_dev = NULL;
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return -1;
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}
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/* Check if it's actually a DOS volume */
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if (memcmp(buffer + DOS_BOOT_MAGIC_OFFSET, "\x55\xAA", 2)) {
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cur_dev = NULL;
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return -1;
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}
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/* Check for FAT12/FAT16/FAT32 filesystem */
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if (!memcmp(buffer + DOS_FS_TYPE_OFFSET, "FAT", 3))
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return 0;
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if (!memcmp(buffer + DOS_FS32_TYPE_OFFSET, "FAT32", 5))
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return 0;
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cur_dev = NULL;
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return -1;
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}
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int fat_register_device(struct blk_desc *dev_desc, int part_no)
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{
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disk_partition_t info;
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/* First close any currently found FAT filesystem */
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cur_dev = NULL;
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/* Read the partition table, if present */
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if (part_get_info(dev_desc, part_no, &info)) {
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if (part_no != 0) {
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printf("** Partition %d not valid on device %d **\n",
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part_no, dev_desc->devnum);
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return -1;
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}
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info.start = 0;
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info.size = dev_desc->lba;
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info.blksz = dev_desc->blksz;
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info.name[0] = 0;
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info.type[0] = 0;
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info.bootable = 0;
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#if CONFIG_IS_ENABLED(PARTITION_UUIDS)
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info.uuid[0] = 0;
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#endif
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}
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return fat_set_blk_dev(dev_desc, &info);
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}
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/*
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* Extract zero terminated short name from a directory entry.
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*/
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static void get_name(dir_entry *dirent, char *s_name)
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{
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char *ptr;
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memcpy(s_name, dirent->name, 8);
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s_name[8] = '\0';
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ptr = s_name;
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while (*ptr && *ptr != ' ')
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ptr++;
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if (dirent->lcase & CASE_LOWER_BASE)
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downcase(s_name, (unsigned)(ptr - s_name));
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if (dirent->ext[0] && dirent->ext[0] != ' ') {
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*ptr++ = '.';
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memcpy(ptr, dirent->ext, 3);
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if (dirent->lcase & CASE_LOWER_EXT)
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downcase(ptr, 3);
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ptr[3] = '\0';
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while (*ptr && *ptr != ' ')
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ptr++;
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}
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*ptr = '\0';
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if (*s_name == DELETED_FLAG)
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*s_name = '\0';
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else if (*s_name == aRING)
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*s_name = DELETED_FLAG;
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}
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static int flush_dirty_fat_buffer(fsdata *mydata);
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#if !defined(CONFIG_FAT_WRITE)
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/* Stub for read only operation */
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int flush_dirty_fat_buffer(fsdata *mydata)
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{
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(void)(mydata);
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return 0;
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}
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#endif
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/*
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* Get the entry at index 'entry' in a FAT (12/16/32) table.
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* On failure 0x00 is returned.
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*/
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static __u32 get_fatent(fsdata *mydata, __u32 entry)
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{
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__u32 bufnum;
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__u32 offset, off8;
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__u32 ret = 0x00;
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if (CHECK_CLUST(entry, mydata->fatsize)) {
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printf("Error: Invalid FAT entry: 0x%08x\n", entry);
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return ret;
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}
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switch (mydata->fatsize) {
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case 32:
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bufnum = entry / FAT32BUFSIZE;
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offset = entry - bufnum * FAT32BUFSIZE;
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break;
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case 16:
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bufnum = entry / FAT16BUFSIZE;
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offset = entry - bufnum * FAT16BUFSIZE;
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break;
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case 12:
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bufnum = entry / FAT12BUFSIZE;
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offset = entry - bufnum * FAT12BUFSIZE;
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break;
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default:
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/* Unsupported FAT size */
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return ret;
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}
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debug("FAT%d: entry: 0x%08x = %d, offset: 0x%04x = %d\n",
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mydata->fatsize, entry, entry, offset, offset);
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/* Read a new block of FAT entries into the cache. */
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if (bufnum != mydata->fatbufnum) {
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__u32 getsize = FATBUFBLOCKS;
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__u8 *bufptr = mydata->fatbuf;
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__u32 fatlength = mydata->fatlength;
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__u32 startblock = bufnum * FATBUFBLOCKS;
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/* Cap length if fatlength is not a multiple of FATBUFBLOCKS */
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if (startblock + getsize > fatlength)
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getsize = fatlength - startblock;
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startblock += mydata->fat_sect; /* Offset from start of disk */
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/* Write back the fatbuf to the disk */
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if (flush_dirty_fat_buffer(mydata) < 0)
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return -1;
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if (disk_read(startblock, getsize, bufptr) < 0) {
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debug("Error reading FAT blocks\n");
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return ret;
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}
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mydata->fatbufnum = bufnum;
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}
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/* Get the actual entry from the table */
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switch (mydata->fatsize) {
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case 32:
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ret = FAT2CPU32(((__u32 *) mydata->fatbuf)[offset]);
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break;
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case 16:
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ret = FAT2CPU16(((__u16 *) mydata->fatbuf)[offset]);
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break;
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case 12:
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off8 = (offset * 3) / 2;
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/* fatbut + off8 may be unaligned, read in byte granularity */
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ret = mydata->fatbuf[off8] + (mydata->fatbuf[off8 + 1] << 8);
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if (offset & 0x1)
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ret >>= 4;
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ret &= 0xfff;
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}
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debug("FAT%d: ret: 0x%08x, entry: 0x%08x, offset: 0x%04x\n",
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mydata->fatsize, ret, entry, offset);
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return ret;
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}
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/*
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* Read at most 'size' bytes from the specified cluster into 'buffer'.
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* Return 0 on success, -1 otherwise.
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*/
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static int
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get_cluster(fsdata *mydata, __u32 clustnum, __u8 *buffer, unsigned long size)
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{
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__u32 idx = 0;
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__u32 startsect;
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int ret;
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if (clustnum > 0) {
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startsect = clust_to_sect(mydata, clustnum);
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} else {
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startsect = mydata->rootdir_sect;
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}
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debug("gc - clustnum: %d, startsect: %d\n", clustnum, startsect);
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if ((unsigned long)buffer & (ARCH_DMA_MINALIGN - 1)) {
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ALLOC_CACHE_ALIGN_BUFFER(__u8, tmpbuf, mydata->sect_size);
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debug("FAT: Misaligned buffer address (%p)\n", buffer);
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while (size >= mydata->sect_size) {
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ret = disk_read(startsect++, 1, tmpbuf);
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if (ret != 1) {
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debug("Error reading data (got %d)\n", ret);
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return -1;
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}
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memcpy(buffer, tmpbuf, mydata->sect_size);
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buffer += mydata->sect_size;
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size -= mydata->sect_size;
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}
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} else {
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idx = size / mydata->sect_size;
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ret = disk_read(startsect, idx, buffer);
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if (ret != idx) {
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debug("Error reading data (got %d)\n", ret);
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return -1;
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}
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startsect += idx;
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idx *= mydata->sect_size;
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buffer += idx;
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size -= idx;
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}
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if (size) {
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ALLOC_CACHE_ALIGN_BUFFER(__u8, tmpbuf, mydata->sect_size);
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ret = disk_read(startsect, 1, tmpbuf);
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if (ret != 1) {
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debug("Error reading data (got %d)\n", ret);
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return -1;
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}
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memcpy(buffer, tmpbuf, size);
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}
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return 0;
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}
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/*
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* Read at most 'maxsize' bytes from 'pos' in the file associated with 'dentptr'
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* into 'buffer'.
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* Update the number of bytes read in *gotsize or return -1 on fatal errors.
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*/
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__u8 get_contents_vfatname_block[MAX_CLUSTSIZE]
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__aligned(ARCH_DMA_MINALIGN);
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static int get_contents(fsdata *mydata, dir_entry *dentptr, loff_t pos,
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__u8 *buffer, loff_t maxsize, loff_t *gotsize)
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{
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loff_t filesize = FAT2CPU32(dentptr->size);
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unsigned int bytesperclust = mydata->clust_size * mydata->sect_size;
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__u32 curclust = START(dentptr);
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__u32 endclust, newclust;
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loff_t actsize;
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*gotsize = 0;
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debug("Filesize: %llu bytes\n", filesize);
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if (pos >= filesize) {
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debug("Read position past EOF: %llu\n", pos);
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return 0;
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}
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if (maxsize > 0 && filesize > pos + maxsize)
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filesize = pos + maxsize;
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debug("%llu bytes\n", filesize);
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actsize = bytesperclust;
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/* go to cluster at pos */
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while (actsize <= pos) {
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curclust = get_fatent(mydata, curclust);
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if (CHECK_CLUST(curclust, mydata->fatsize)) {
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debug("curclust: 0x%x\n", curclust);
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debug("Invalid FAT entry\n");
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return 0;
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}
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actsize += bytesperclust;
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}
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/* actsize > pos */
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actsize -= bytesperclust;
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filesize -= actsize;
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pos -= actsize;
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/* align to beginning of next cluster if any */
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if (pos) {
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actsize = min(filesize, (loff_t)bytesperclust);
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if (get_cluster(mydata, curclust, get_contents_vfatname_block,
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(int)actsize) != 0) {
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printf("Error reading cluster\n");
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return -1;
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}
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filesize -= actsize;
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actsize -= pos;
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memcpy(buffer, get_contents_vfatname_block + pos, actsize);
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*gotsize += actsize;
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if (!filesize)
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return 0;
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buffer += actsize;
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curclust = get_fatent(mydata, curclust);
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if (CHECK_CLUST(curclust, mydata->fatsize)) {
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debug("curclust: 0x%x\n", curclust);
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debug("Invalid FAT entry\n");
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return 0;
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}
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}
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actsize = bytesperclust;
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endclust = curclust;
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do {
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/* search for consecutive clusters */
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while (actsize < filesize) {
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newclust = get_fatent(mydata, endclust);
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if ((newclust - 1) != endclust)
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goto getit;
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if (CHECK_CLUST(newclust, mydata->fatsize)) {
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debug("curclust: 0x%x\n", newclust);
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debug("Invalid FAT entry\n");
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return 0;
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}
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endclust = newclust;
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actsize += bytesperclust;
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}
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/* get remaining bytes */
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actsize = filesize;
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if (get_cluster(mydata, curclust, buffer, (int)actsize) != 0) {
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printf("Error reading cluster\n");
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return -1;
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}
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*gotsize += actsize;
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return 0;
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getit:
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if (get_cluster(mydata, curclust, buffer, (int)actsize) != 0) {
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printf("Error reading cluster\n");
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return -1;
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}
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*gotsize += (int)actsize;
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filesize -= actsize;
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buffer += actsize;
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curclust = get_fatent(mydata, endclust);
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if (CHECK_CLUST(curclust, mydata->fatsize)) {
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debug("curclust: 0x%x\n", curclust);
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printf("Invalid FAT entry\n");
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return 0;
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}
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actsize = bytesperclust;
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endclust = curclust;
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} while (1);
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}
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/*
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* Extract the file name information from 'slotptr' into 'l_name',
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* starting at l_name[*idx].
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* Return 1 if terminator (zero byte) is found, 0 otherwise.
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*/
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static int slot2str(dir_slot *slotptr, char *l_name, int *idx)
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{
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int j;
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for (j = 0; j <= 8; j += 2) {
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l_name[*idx] = slotptr->name0_4[j];
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if (l_name[*idx] == 0x00)
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return 1;
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(*idx)++;
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}
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for (j = 0; j <= 10; j += 2) {
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l_name[*idx] = slotptr->name5_10[j];
|
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if (l_name[*idx] == 0x00)
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return 1;
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(*idx)++;
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}
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for (j = 0; j <= 2; j += 2) {
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l_name[*idx] = slotptr->name11_12[j];
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if (l_name[*idx] == 0x00)
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return 1;
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(*idx)++;
|
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}
|
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|
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return 0;
|
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}
|
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|
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/* Calculate short name checksum */
|
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static __u8 mkcksum(const char name[8], const char ext[3])
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{
|
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int i;
|
|
|
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__u8 ret = 0;
|
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|
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for (i = 0; i < 8; i++)
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ret = (((ret & 1) << 7) | ((ret & 0xfe) >> 1)) + name[i];
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for (i = 0; i < 3; i++)
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ret = (((ret & 1) << 7) | ((ret & 0xfe) >> 1)) + ext[i];
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|
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return ret;
|
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}
|
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|
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/*
|
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* Read boot sector and volume info from a FAT filesystem
|
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*/
|
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static int
|
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read_bootsectandvi(boot_sector *bs, volume_info *volinfo, int *fatsize)
|
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{
|
|
__u8 *block;
|
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volume_info *vistart;
|
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int ret = 0;
|
|
|
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if (cur_dev == NULL) {
|
|
debug("Error: no device selected\n");
|
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return -1;
|
|
}
|
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|
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block = malloc_cache_aligned(cur_dev->blksz);
|
|
if (block == NULL) {
|
|
debug("Error: allocating block\n");
|
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return -1;
|
|
}
|
|
|
|
if (disk_read(0, 1, block) < 0) {
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debug("Error: reading block\n");
|
|
goto fail;
|
|
}
|
|
|
|
memcpy(bs, block, sizeof(boot_sector));
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|
bs->reserved = FAT2CPU16(bs->reserved);
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bs->fat_length = FAT2CPU16(bs->fat_length);
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bs->secs_track = FAT2CPU16(bs->secs_track);
|
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bs->heads = FAT2CPU16(bs->heads);
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bs->total_sect = FAT2CPU32(bs->total_sect);
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|
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/* FAT32 entries */
|
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if (bs->fat_length == 0) {
|
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/* Assume FAT32 */
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bs->fat32_length = FAT2CPU32(bs->fat32_length);
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bs->flags = FAT2CPU16(bs->flags);
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bs->root_cluster = FAT2CPU32(bs->root_cluster);
|
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bs->info_sector = FAT2CPU16(bs->info_sector);
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bs->backup_boot = FAT2CPU16(bs->backup_boot);
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vistart = (volume_info *)(block + sizeof(boot_sector));
|
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*fatsize = 32;
|
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} else {
|
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vistart = (volume_info *)&(bs->fat32_length);
|
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*fatsize = 0;
|
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}
|
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memcpy(volinfo, vistart, sizeof(volume_info));
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|
|
|
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->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);
|
|
mydata->root_cluster =
|
|
sect_to_clust(mydata, mydata->rootdir_sect);
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
|
|
/*
|
|
* 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:
|
|
*
|
|
* 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 more complete example, see fat_itr_resolve()
|
|
*/
|
|
|
|
typedef struct {
|
|
fsdata *fsdata; /* filesystem parameters */
|
|
unsigned start_clust; /* first cluster */
|
|
unsigned clust; /* current cluster */
|
|
unsigned next_clust; /* next cluster if remaining == 0 */
|
|
int last_cluster; /* set once we've read last cluster */
|
|
int is_root; /* is iterator at root directory */
|
|
int remaining; /* remaining dent's in current cluster */
|
|
|
|
/* current iterator position values: */
|
|
dir_entry *dent; /* current directory entry */
|
|
char l_name[VFAT_MAXLEN_BYTES]; /* long (vfat) name */
|
|
char s_name[14]; /* short 8.3 name */
|
|
char *name; /* l_name if there is one, else s_name */
|
|
|
|
/* storage for current cluster in memory: */
|
|
u8 block[MAX_CLUSTSIZE] __aligned(ARCH_DMA_MINALIGN);
|
|
} fat_itr;
|
|
|
|
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 = 0;
|
|
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->is_root = 1;
|
|
}
|
|
itr->dent = NULL;
|
|
itr->remaining = 0;
|
|
itr->last_cluster = 0;
|
|
}
|
|
|
|
static void *next_cluster(fat_itr *itr)
|
|
{
|
|
fsdata *mydata = itr->fsdata; /* for silly macros */
|
|
int ret;
|
|
u32 sect;
|
|
|
|
/* have we reached the end? */
|
|
if (itr->last_cluster)
|
|
return NULL;
|
|
|
|
sect = clust_to_sect(itr->fsdata, itr->next_clust);
|
|
|
|
debug("FAT read(sect=%d), clust_size=%d, DIRENTSPERBLOCK=%zd\n",
|
|
sect, itr->fsdata->clust_size, DIRENTSPERBLOCK);
|
|
|
|
/*
|
|
* 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, itr->fsdata->clust_size,
|
|
itr->block);
|
|
if (ret < 0) {
|
|
debug("Error: reading block\n");
|
|
return NULL;
|
|
}
|
|
|
|
itr->clust = itr->next_clust;
|
|
if (itr->is_root && itr->fsdata->fatsize != 32) {
|
|
itr->next_clust++;
|
|
sect = clust_to_sect(itr->fsdata, itr->next_clust);
|
|
if (sect - itr->fsdata->rootdir_sect >=
|
|
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) {
|
|
struct dir_entry *dent = next_cluster(itr);
|
|
unsigned nbytes = itr->fsdata->sect_size *
|
|
itr->fsdata->clust_size;
|
|
|
|
/* 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->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->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);
|
|
|
|
/* 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;
|
|
}
|
|
|
|
itr->l_name[n] = '\0';
|
|
|
|
chksum = mkcksum(dent->name, dent->ext);
|
|
|
|
/* 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->name, dent->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;
|
|
|
|
while (1) {
|
|
dent = next_dent(itr);
|
|
if (!dent)
|
|
return 0;
|
|
|
|
if (dent->name[0] == DELETED_FLAG ||
|
|
dent->name[0] == aRING)
|
|
continue;
|
|
|
|
if (dent->attr & ATTR_VOLUME) {
|
|
if ((dent->attr & ATTR_VFAT) == ATTR_VFAT &&
|
|
(dent->name[0] & LAST_LONG_ENTRY_MASK)) {
|
|
dent = extract_vfat_name(itr);
|
|
if (!dent)
|
|
continue;
|
|
itr->name = itr->l_name;
|
|
break;
|
|
} else {
|
|
/* Volume label or VFAT entry, skip */
|
|
continue;
|
|
}
|
|
}
|
|
|
|
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->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 defined(CONFIG_IDE) || \
|
|
defined(CONFIG_SATA) || \
|
|
defined(CONFIG_SCSI) || \
|
|
defined(CONFIG_CMD_USB) || \
|
|
defined(CONFIG_MMC)
|
|
printf("Interface: ");
|
|
switch (cur_dev->if_type) {
|
|
case IF_TYPE_IDE:
|
|
printf("IDE");
|
|
break;
|
|
case IF_TYPE_SATA:
|
|
printf("SATA");
|
|
break;
|
|
case IF_TYPE_SCSI:
|
|
printf("SCSI");
|
|
break;
|
|
case IF_TYPE_ATAPI:
|
|
printf("ATAPI");
|
|
break;
|
|
case IF_TYPE_USB:
|
|
printf("USB");
|
|
break;
|
|
case IF_TYPE_DOC:
|
|
printf("DOC");
|
|
break;
|
|
case IF_TYPE_MMC:
|
|
printf("MMC");
|
|
break;
|
|
default:
|
|
printf("Unknown");
|
|
}
|
|
|
|
printf("\n Device %d: ", cur_dev->devnum);
|
|
dev_print(cur_dev);
|
|
#endif
|
|
|
|
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);
|
|
fat_itr_root(itr, &fsdata);
|
|
if (!fat_itr_resolve(itr, filename, TYPE_DIR)) {
|
|
*size = 0;
|
|
ret = 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);
|
|
ret = get_contents(&fsdata, itr->dent, 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)
|
|
{
|
|
}
|