/* * linux/fs/fat/dir.c * * directory handling functions for fat-based filesystems * * Written 1992,1993 by Werner Almesberger * * Hidden files 1995 by Albert Cahalan * * VFAT extensions by Gordon Chaffee * Merged with msdos fs by Henrik Storner * Rewritten for constant inumbers. Plugged buffer overrun in readdir(). AV * Short name translation 1999, 2001 by Wolfram Pienkoss */ #include #include #include #include #include #include #include #include #include #include #include #include #define PRINTK(X) struct file_operations fat_dir_operations = { read: generic_read_dir, readdir: fat_readdir, ioctl: fat_dir_ioctl, fsync: file_fsync, }; /* * Convert Unicode 16 to UTF8, translated Unicode, or ASCII. * If uni_xlate is enabled and we can't get a 1:1 conversion, use a * colon as an escape character since it is normally invalid on the vfat * filesystem. The following four characters are the hexadecimal digits * of Unicode value. This lets us do a full dump and restore of Unicode * filenames. We could get into some trouble with long Unicode names, * but ignore that right now. * Ahem... Stack smashing in ring 0 isn't fun. Fixed. */ static int uni16_to_x8(unsigned char *ascii, wchar_t *uni, int uni_xlate, struct nls_table *nls) { wchar_t *ip, ec; unsigned char *op, nc; int charlen; int k; ip = uni; op = ascii; while (*ip) { ec = *ip++; if ( (charlen = nls->uni2char(ec, op, NLS_MAX_CHARSET_SIZE)) > 0) { op += charlen; } else { if (uni_xlate == 1) { *op = ':'; for (k = 4; k > 0; k--) { nc = ec & 0xF; op[k] = nc > 9 ? nc + ('a' - 10) : nc + '0'; ec >>= 4; } op += 5; } else { *op++ = '?'; } } /* We have some slack there, so it's OK */ if (op>ascii+256) { op = ascii + 256; break; } } *op = 0; return (op - ascii); } #if 0 static void dump_de(struct msdos_dir_entry *de) { int i; unsigned char *p = (unsigned char *) de; printk("["); for (i = 0; i < 32; i++, p++) { printk("%02x ", *p); } printk("]\n"); } #endif static inline unsigned char fat_tolower(struct nls_table *t, unsigned char c) { unsigned char nc = t->charset2lower[c]; return nc ? nc : c; } static inline int fat_short2uni(struct nls_table *t, unsigned char *c, int clen, wchar_t *uni) { int charlen; charlen = t->char2uni(c, clen, uni); if (charlen < 0) { *uni = 0x003f; /* a question mark */ charlen = 1; } return charlen; } static inline int fat_short2lower_uni(struct nls_table *t, unsigned char *c, int clen, wchar_t *uni) { int charlen; wchar_t wc; charlen = t->char2uni(c, clen, &wc); if (charlen < 0) { *uni = 0x003f; /* a question mark */ charlen = 1; } else if (charlen <= 1) { unsigned char nc = t->charset2lower[*c]; if (!nc) nc = *c; if ( (charlen = t->char2uni(&nc, 1, uni)) < 0) { *uni = 0x003f; /* a question mark */ charlen = 1; } } else *uni = wc; return charlen; } static int fat_strnicmp(struct nls_table *t, const unsigned char *s1, const unsigned char *s2, int len) { while(len--) if (fat_tolower(t, *s1++) != fat_tolower(t, *s2++)) return 1; return 0; } static inline int fat_shortname2uni(struct nls_table *nls, char *buf, int buf_size, wchar_t *uni_buf, unsigned short opt, int lower) { int len = 0; if (opt & VFAT_SFN_DISPLAY_LOWER) len = fat_short2lower_uni(nls, buf, buf_size, uni_buf); else if (opt & VFAT_SFN_DISPLAY_WIN95) len = fat_short2uni(nls, buf, buf_size, uni_buf); else if (opt & VFAT_SFN_DISPLAY_WINNT) { if (lower) len = fat_short2lower_uni(nls, buf, buf_size, uni_buf); else len = fat_short2uni(nls, buf, buf_size, uni_buf); } else len = fat_short2uni(nls, buf, buf_size, uni_buf); return len; } /* * Return values: negative -> error, 0 -> not found, positive -> found, * value is the total amount of slots, including the shortname entry. */ int fat_search_long(struct inode *inode, const char *name, int name_len, int anycase, loff_t *spos, loff_t *lpos) { struct super_block *sb = inode->i_sb; struct buffer_head *bh = NULL; struct msdos_dir_entry *de; struct nls_table *nls_io = MSDOS_SB(sb)->nls_io; struct nls_table *nls_disk = MSDOS_SB(sb)->nls_disk; wchar_t bufuname[14]; unsigned char xlate_len, long_slots; wchar_t *unicode = NULL; char work[8], bufname[260]; /* 256 + 4 */ int uni_xlate = MSDOS_SB(sb)->options.unicode_xlate; int utf8 = MSDOS_SB(sb)->options.utf8; unsigned short opt_shortname = MSDOS_SB(sb)->options.shortname; int ino, chl, i, j, last_u, res = 0; loff_t cpos = 0; while(1) { if (fat_get_entry(inode,&cpos,&bh,&de,&ino) == -1) goto EODir; parse_record: long_slots = 0; if (de->name[0] == (__s8) DELETED_FLAG) continue; if (de->attr != ATTR_EXT && (de->attr & ATTR_VOLUME)) continue; if (de->attr != ATTR_EXT && IS_FREE(de->name)) continue; if (de->attr == ATTR_EXT) { struct msdos_dir_slot *ds; unsigned char id; unsigned char slot; unsigned char slots; unsigned char sum; unsigned char alias_checksum; if (!unicode) { unicode = (wchar_t *) __get_free_page(GFP_KERNEL); if (!unicode) { fat_brelse(sb, bh); return -ENOMEM; } } parse_long: slots = 0; ds = (struct msdos_dir_slot *) de; id = ds->id; if (!(id & 0x40)) continue; slots = id & ~0x40; if (slots > 20 || !slots) /* ceil(256 * 2 / 26) */ continue; long_slots = slots; alias_checksum = ds->alias_checksum; slot = slots; while (1) { int offset; slot--; offset = slot * 13; fat16_towchar(unicode + offset, ds->name0_4, 5); fat16_towchar(unicode + offset + 5, ds->name5_10, 6); fat16_towchar(unicode + offset + 11, ds->name11_12, 2); if (ds->id & 0x40) { unicode[offset + 13] = 0; } if (fat_get_entry(inode,&cpos,&bh,&de,&ino)<0) goto EODir; if (slot == 0) break; ds = (struct msdos_dir_slot *) de; if (ds->attr != ATTR_EXT) goto parse_record; if ((ds->id & ~0x40) != slot) goto parse_long; if (ds->alias_checksum != alias_checksum) goto parse_long; } if (de->name[0] == (__s8) DELETED_FLAG) continue; if (de->attr == ATTR_EXT) goto parse_long; if (IS_FREE(de->name) || (de->attr & ATTR_VOLUME)) continue; for (sum = 0, i = 0; i < 11; i++) sum = (((sum&1)<<7)|((sum&0xfe)>>1)) + de->name[i]; if (sum != alias_checksum) long_slots = 0; } for (i = 0; i < 8; i++) { /* see namei.c, msdos_format_name */ if (de->name[i] == 0x05) work[i] = 0xE5; else work[i] = de->name[i]; } for (i = 0, j = 0, last_u = 0; i < 8;) { if (!work[i]) break; chl = fat_shortname2uni(nls_disk, &work[i], 8 - i, &bufuname[j++], opt_shortname, de->lcase & CASE_LOWER_BASE); if (chl <= 1) { if (work[i] != ' ') last_u = j; } else { last_u = j; } i += chl; } j = last_u; fat_short2uni(nls_disk, ".", 1, &bufuname[j++]); for (i = 0; i < 3;) { if (!de->ext[i]) break; chl = fat_shortname2uni(nls_disk, &de->ext[i], 3 - i, &bufuname[j++], opt_shortname, de->lcase & CASE_LOWER_EXT); if (chl <= 1) { if (de->ext[i] != ' ') last_u = j; } else { last_u = j; } i += chl; } if (!last_u) continue; bufuname[last_u] = 0x0000; xlate_len = utf8 ?utf8_wcstombs(bufname, bufuname, sizeof(bufname)) :uni16_to_x8(bufname, bufuname, uni_xlate, nls_io); if (xlate_len == name_len) if ((!anycase && !memcmp(name, bufname, xlate_len)) || (anycase && !fat_strnicmp(nls_io, name, bufname, xlate_len))) goto Found; if (long_slots) { xlate_len = utf8 ?utf8_wcstombs(bufname, unicode, sizeof(bufname)) :uni16_to_x8(bufname, unicode, uni_xlate, nls_io); if (xlate_len != name_len) continue; if ((!anycase && !memcmp(name, bufname, xlate_len)) || (anycase && !fat_strnicmp(nls_io, name, bufname, xlate_len))) goto Found; } } Found: res = long_slots + 1; *spos = cpos - sizeof(struct msdos_dir_entry); *lpos = cpos - res*sizeof(struct msdos_dir_entry); EODir: fat_brelse(sb, bh); if (unicode) { free_page((unsigned long) unicode); } return res; } static int fat_readdirx(struct inode *inode, struct file *filp, void *dirent, filldir_t filldir, int shortnames, int both) { struct super_block *sb = inode->i_sb; struct buffer_head *bh; struct msdos_dir_entry *de; struct nls_table *nls_io = MSDOS_SB(sb)->nls_io; struct nls_table *nls_disk = MSDOS_SB(sb)->nls_disk; wchar_t bufuname[14]; unsigned char long_slots; wchar_t *unicode = NULL; char c, work[8], bufname[56], *ptname = bufname; unsigned long lpos, dummy, *furrfu = &lpos; int uni_xlate = MSDOS_SB(sb)->options.unicode_xlate; int isvfat = MSDOS_SB(sb)->options.isvfat; int utf8 = MSDOS_SB(sb)->options.utf8; int nocase = MSDOS_SB(sb)->options.nocase; unsigned short opt_shortname = MSDOS_SB(sb)->options.shortname; int ino, inum, chi, chl, i, i2, j, last, last_u, dotoffset = 0; loff_t cpos; cpos = filp->f_pos; /* Fake . and .. for the root directory. */ if (inode->i_ino == MSDOS_ROOT_INO) { while (cpos < 2) { if (filldir(dirent, "..", cpos+1, cpos, MSDOS_ROOT_INO, DT_DIR) < 0) return 0; cpos++; filp->f_pos++; } if (cpos == 2) { dummy = 2; furrfu = &dummy; cpos = 0; } } if (cpos & (sizeof(struct msdos_dir_entry)-1)) return -ENOENT; bh = NULL; GetNew: long_slots = 0; if (fat_get_entry(inode,&cpos,&bh,&de,&ino) == -1) goto EODir; /* Check for long filename entry */ if (isvfat) { if (de->name[0] == (__s8) DELETED_FLAG) goto RecEnd; if (de->attr != ATTR_EXT && (de->attr & ATTR_VOLUME)) goto RecEnd; if (de->attr != ATTR_EXT && IS_FREE(de->name)) goto RecEnd; } else { if ((de->attr & ATTR_VOLUME) || IS_FREE(de->name)) goto RecEnd; } if (isvfat && de->attr == ATTR_EXT) { struct msdos_dir_slot *ds; unsigned char id; unsigned char slot; unsigned char slots; unsigned char sum; unsigned char alias_checksum; if (!unicode) { unicode = (wchar_t *) __get_free_page(GFP_KERNEL); if (!unicode) { filp->f_pos = cpos; fat_brelse(sb, bh); return -ENOMEM; } } ParseLong: slots = 0; ds = (struct msdos_dir_slot *) de; id = ds->id; if (!(id & 0x40)) goto RecEnd; slots = id & ~0x40; if (slots > 20 || !slots) /* ceil(256 * 2 / 26) */ goto RecEnd; long_slots = slots; alias_checksum = ds->alias_checksum; slot = slots; while (1) { int offset; slot--; offset = slot * 13; fat16_towchar(unicode + offset, ds->name0_4, 5); fat16_towchar(unicode + offset + 5, ds->name5_10, 6); fat16_towchar(unicode + offset + 11, ds->name11_12, 2); if (ds->id & 0x40) { unicode[offset + 13] = 0; } if (fat_get_entry(inode,&cpos,&bh,&de,&ino) == -1) goto EODir; if (slot == 0) break; ds = (struct msdos_dir_slot *) de; if (ds->attr != ATTR_EXT) goto RecEnd; /* XXX */ if ((ds->id & ~0x40) != slot) goto ParseLong; if (ds->alias_checksum != alias_checksum) goto ParseLong; } if (de->name[0] == (__s8) DELETED_FLAG) goto RecEnd; if (de->attr == ATTR_EXT) goto ParseLong; if (IS_FREE(de->name) || (de->attr & ATTR_VOLUME)) goto RecEnd; for (sum = 0, i = 0; i < 11; i++) sum = (((sum&1)<<7)|((sum&0xfe)>>1)) + de->name[i]; if (sum != alias_checksum) long_slots = 0; } if ((de->attr & ATTR_HIDDEN) && MSDOS_SB(sb)->options.dotsOK) { *ptname++ = '.'; dotoffset = 1; } for (i = 0; i < 8; i++) { /* see namei.c, msdos_format_name */ if (de->name[i] == 0x05) work[i] = 0xE5; else work[i] = de->name[i]; } for (i = 0, j = 0, last = 0, last_u = 0; i < 8;) { if (!(c = work[i])) break; chl = fat_shortname2uni(nls_disk, &work[i], 8 - i, &bufuname[j++], opt_shortname, de->lcase & CASE_LOWER_BASE); if (chl <= 1) { ptname[i++] = (!nocase && c>='A' && c<='Z') ? c+32 : c; if (c != ' ') { last = i; last_u = j; } } else { last_u = j; for (chi = 0; chi < chl && i < 8; chi++) { ptname[i] = work[i]; i++; last = i; } } } i = last; j = last_u; fat_short2uni(nls_disk, ".", 1, &bufuname[j++]); ptname[i++] = '.'; for (i2 = 0; i2 < 3;) { if (!(c = de->ext[i2])) break; chl = fat_shortname2uni(nls_disk, &de->ext[i2], 3 - i2, &bufuname[j++], opt_shortname, de->lcase & CASE_LOWER_EXT); if (chl <= 1) { i2++; ptname[i++] = (!nocase && c>='A' && c<='Z') ? c+32 : c; if (c != ' ') { last = i; last_u = j; } } else { last_u = j; for (chi = 0; chi < chl && i2 < 3; chi++) { ptname[i++] = de->ext[i2++]; last = i; } } } if (!last) goto RecEnd; i = last + dotoffset; j = last_u; lpos = cpos - (long_slots+1)*sizeof(struct msdos_dir_entry); if (!memcmp(de->name,MSDOS_DOT,11)) inum = inode->i_ino; else if (!memcmp(de->name,MSDOS_DOTDOT,11)) { /* inum = fat_parent_ino(inode,0); */ inum = filp->f_dentry->d_parent->d_inode->i_ino; } else { struct inode *tmp = fat_iget(sb, ino); if (tmp) { inum = tmp->i_ino; iput(tmp); } else inum = iunique(sb, MSDOS_ROOT_INO); } if (isvfat) { bufuname[j] = 0x0000; i = utf8 ? utf8_wcstombs(bufname, bufuname, sizeof(bufname)) : uni16_to_x8(bufname, bufuname, uni_xlate, nls_io); } if (!long_slots||shortnames) { if (both) bufname[i] = '\0'; if (filldir(dirent, bufname, i, *furrfu, inum, (de->attr & ATTR_DIR) ? DT_DIR : DT_REG) < 0) goto FillFailed; } else { char longname[275]; int long_len = utf8 ? utf8_wcstombs(longname, unicode, sizeof(longname)) : uni16_to_x8(longname, unicode, uni_xlate, nls_io); if (both) { memcpy(&longname[long_len+1], bufname, i); long_len += i; } if (filldir(dirent, longname, long_len, *furrfu, inum, (de->attr & ATTR_DIR) ? DT_DIR : DT_REG) < 0) goto FillFailed; } RecEnd: furrfu = &lpos; filp->f_pos = cpos; goto GetNew; EODir: filp->f_pos = cpos; FillFailed: if (bh) fat_brelse(sb, bh); if (unicode) { free_page((unsigned long) unicode); } return 0; } int fat_readdir(struct file *filp, void *dirent, filldir_t filldir) { struct inode *inode = filp->f_dentry->d_inode; return fat_readdirx(inode, filp, dirent, filldir, 0, 0); } static int vfat_ioctl_fill( void * buf, const char * name, int name_len, loff_t offset, ino_t ino, unsigned int d_type) { struct dirent *d1 = (struct dirent *)buf; struct dirent *d2 = d1 + 1; int len, slen; int dotdir; get_user(len, &d1->d_reclen); if (len != 0) { return -1; } if ((name_len == 1 && name[0] == '.') || (name_len == 2 && name[0] == '.' && name[1] == '.')) { dotdir = 1; len = name_len; } else { dotdir = 0; len = strlen(name); } if (len != name_len) { copy_to_user(d2->d_name, name, len); put_user(0, d2->d_name + len); put_user(len, &d2->d_reclen); put_user(ino, &d2->d_ino); put_user(offset, &d2->d_off); slen = name_len - len; copy_to_user(d1->d_name, name+len+1, slen); put_user(0, d1->d_name+slen); put_user(slen, &d1->d_reclen); } else { put_user(0, d2->d_name); put_user(0, &d2->d_reclen); copy_to_user(d1->d_name, name, len); put_user(0, d1->d_name+len); put_user(len, &d1->d_reclen); } PRINTK(("FAT d1=%p d2=%p len=%d, name_len=%d\n", d1, d2, len, name_len)); return 0; } int fat_dir_ioctl(struct inode * inode, struct file * filp, unsigned int cmd, unsigned long arg) { int err; /* * We want to provide an interface for Samba to be able * to get the short filename for a given long filename. * Samba should use this ioctl instead of readdir() to * get the information it needs. */ switch (cmd) { case VFAT_IOCTL_READDIR_BOTH: { struct dirent *d1 = (struct dirent *)arg; err = verify_area(VERIFY_WRITE, d1, sizeof(struct dirent[2])); if (err) return err; put_user(0, &d1->d_reclen); return fat_readdirx(inode,filp,(void *)arg, vfat_ioctl_fill, 0, 1); } case VFAT_IOCTL_READDIR_SHORT: { struct dirent *d1 = (struct dirent *)arg; put_user(0, &d1->d_reclen); err = verify_area(VERIFY_WRITE, d1, sizeof(struct dirent[2])); if (err) return err; return fat_readdirx(inode,filp,(void *)arg, vfat_ioctl_fill, 1, 1); } default: /* forward ioctl to CVF extension */ if (MSDOS_SB(inode->i_sb)->cvf_format && MSDOS_SB(inode->i_sb)->cvf_format->cvf_dir_ioctl) return MSDOS_SB(inode->i_sb)->cvf_format ->cvf_dir_ioctl(inode,filp,cmd,arg); return -EINVAL; } return 0; } /***** See if directory is empty */ int fat_dir_empty(struct inode *dir) { loff_t pos; struct buffer_head *bh; struct msdos_dir_entry *de; int ino,result = 0; pos = 0; bh = NULL; while (fat_get_entry(dir,&pos,&bh,&de,&ino) > -1) { /* Ignore vfat longname entries */ if (de->attr == ATTR_EXT) continue; if (!IS_FREE(de->name) && strncmp(de->name,MSDOS_DOT , MSDOS_NAME) && strncmp(de->name,MSDOS_DOTDOT, MSDOS_NAME)) { result = -ENOTEMPTY; break; } } if (bh) fat_brelse(dir->i_sb, bh); return result; } /* This assumes that size of cluster is above the 32*slots */ int fat_add_entries(struct inode *dir,int slots, struct buffer_head **bh, struct msdos_dir_entry **de, int *ino) { struct super_block *sb = dir->i_sb; loff_t offset, curr; int row; struct buffer_head *new_bh; offset = curr = 0; *bh = NULL; row = 0; while (fat_get_entry(dir,&curr,bh,de,ino) > -1) { if (IS_FREE((*de)->name)) { if (++row == slots) return offset; } else { row = 0; offset = curr; } } if ((dir->i_ino == MSDOS_ROOT_INO) && (MSDOS_SB(sb)->fat_bits != 32)) return -ENOSPC; new_bh = fat_extend_dir(dir); if (!new_bh) return -ENOSPC; fat_brelse(sb, new_bh); do fat_get_entry(dir,&curr,bh,de,ino); while (++rowi_sb; struct buffer_head *bh; struct msdos_dir_entry *de; __u16 date, time; if ((bh = fat_extend_dir(dir)) == NULL) return -ENOSPC; /* zeroed out, so... */ fat_date_unix2dos(dir->i_mtime,&time,&date); de = (struct msdos_dir_entry*)&bh->b_data[0]; memcpy(de[0].name,MSDOS_DOT,MSDOS_NAME); memcpy(de[1].name,MSDOS_DOTDOT,MSDOS_NAME); de[0].attr = de[1].attr = ATTR_DIR; de[0].time = de[1].time = CT_LE_W(time); de[0].date = de[1].date = CT_LE_W(date); if (is_vfat) { /* extra timestamps */ de[0].ctime = de[1].ctime = CT_LE_W(time); de[0].adate = de[0].cdate = de[1].adate = de[1].cdate = CT_LE_W(date); } de[0].start = CT_LE_W(MSDOS_I(dir)->i_logstart); de[0].starthi = CT_LE_W(MSDOS_I(dir)->i_logstart>>16); de[1].start = CT_LE_W(MSDOS_I(parent)->i_logstart); de[1].starthi = CT_LE_W(MSDOS_I(parent)->i_logstart>>16); fat_mark_buffer_dirty(sb, bh); fat_brelse(sb, bh); dir->i_atime = dir->i_ctime = dir->i_mtime = CURRENT_TIME; mark_inode_dirty(dir); return 0; } /* * Overrides for Emacs so that we follow Linus's tabbing style. * Emacs will notice this stuff at the end of the file and automatically * adjust the settings for this buffer only. This must remain at the end * of the file. * --------------------------------------------------------------------------- * Local variables: * c-indent-level: 8 * c-brace-imaginary-offset: 0 * c-brace-offset: -8 * c-argdecl-indent: 8 * c-label-offset: -8 * c-continued-statement-offset: 8 * c-continued-brace-offset: 0 * End: */