WebSVN – HelenOS – Blame – //trunk/uspace/srv/fs/fat/fat_dentry.c

Rev	Author	Line No.	Line
3504	jermar	1	/*
		2	* Copyright (c) 2008 Jakub Jermar
		3	* All rights reserved.
		4	*
		5	* Redistribution and use in source and binary forms, with or without
		6	* modification, are permitted provided that the following conditions
		7	* are met:
		8	*
		9	* - Redistributions of source code must retain the above copyright
		10	* notice, this list of conditions and the following disclaimer.
		11	* - Redistributions in binary form must reproduce the above copyright
		12	* notice, this list of conditions and the following disclaimer in the
		13	* documentation and/or other materials provided with the distribution.
		14	* - The name of the author may not be used to endorse or promote products
		15	* derived from this software without specific prior written permission.
		16	*
		17	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
		18	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
		19	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
		20	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
		21	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
		22	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
		23	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
		24	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
		25	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
		26	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
		27	*/
		28
		29	/** @addtogroup fs
		30	* @{
		31	*/
		32
		33	/**
		34	* @file fat_dentry.c
		35	* @brief Functions that work with FAT directory entries.
		36	*/
		37
3505	jermar	38	#include "fat_dentry.h"
3628	jermar	39	#include <ctype.h>
3634	jermar	40	#include <string.h>
3504	jermar	41
3505	jermar	42	#define FAT_PAD ' '
		43
		44	#define FAT_DENTRY_UNUSED 0x00
		45	#define FAT_DENTRY_E5_ESC 0x05
		46	#define FAT_DENTRY_DOT 0x2e
		47	#define FAT_DENTRY_ERASED 0xe5
		48
3628	jermar	49	static bool is_d_char(const char ch)
3505	jermar	50	{
3628	jermar	51	if (isalnum(ch) \|\| ch == '_')
		52	return true;
		53	else
		54	return false;
		55	}
		56
3634	jermar	57	/** Compare path component with the name read from the dentry.
		58	*
		59	* This function compares the path component with the name read from the dentry.
		60	* The comparison is case insensitive and tolerates a mismatch on the trailing
		61	* dot character at the end of the name (i.e. when there is a dot, but no
		62	* extension).
		63	*
		64	* @param name Node name read from the dentry.
		65	* @param component Path component.
		66	*
		67	* @return Zero on match, non-zero otherwise.
		68	*/
		69	int fat_dentry_namecmp(char name, const char component)
		70	{
		71	int rc;
		72	if (!(rc = stricmp(name, component)))
		73	return rc;
		74	if (!strchr(name, '.')) {
		75	/*
		76	* There is no '.' in the name, so we know that there is enough
		77	* space for appending an extra '.' to name.
		78	*/
		79	name[strlen(name)] = '.';
		80	name[strlen(name) + 1] = '\0';
		81	rc = stricmp(name, component);
		82	}
		83	return rc;
		84	}
		85
3628	jermar	86	bool fat_dentry_name_verify(const char *name)
		87	{
		88	unsigned i, dot;
		89	bool dot_found = false;
		90
		91
		92	for (i = 0; name[i]; i++) {
		93	if (name[i] == '.') {
		94	if (dot_found) {
		95	return false;
		96	} else {
		97	dot_found = true;
		98	dot = i;
		99	}
		100	} else {
		101	if (!is_d_char(name[i]))
		102	return false;
		103	}
		104	}
		105
		106	if (dot_found) {
		107	if (dot > FAT_NAME_LEN)
		108	return false;
		109	if (i - dot > FAT_EXT_LEN + 1)
		110	return false;
		111	} else {
		112	if (i > FAT_NAME_LEN)
		113	return false;
		114	}
		115
		116	return true;
		117	}
		118
		119	void fat_dentry_name_get(const fat_dentry_t d, char buf)
		120	{
3505	jermar	121	int i;
		122
		123	for (i = 0; i < FAT_NAME_LEN; i++) {
		124	if (d->name[i] == FAT_PAD)
		125	break;
		126	if (d->name[i] == FAT_DENTRY_E5_ESC)
		127	*buf++ = 0xe5;
		128	else
		129	*buf++ = d->name[i];
		130	}
		131	if (d->ext[0] != FAT_PAD)
		132	*buf++ = '.';
		133	for (i = 0; i < FAT_EXT_LEN; i++) {
		134	if (d->ext[i] == FAT_PAD) {
		135	*buf = '\0';
		136	return;
		137	}
		138	if (d->ext[i] == FAT_DENTRY_E5_ESC)
		139	*buf++ = 0xe5;
		140	else
		141	*buf++ = d->ext[i];
		142	}
		143	*buf = '\0';
		144	}
		145
3628	jermar	146	void fat_dentry_name_set(fat_dentry_t d, const char name)
3505	jermar	147	{
3628	jermar	148	int i;
		149	const char fake_ext[] = " ";
		150
		151
		152	for (i = 0; i < FAT_NAME_LEN; i++) {
		153	switch ((uint8_t) *name) {
		154	case 0xe5:
		155	d->name[i] = FAT_DENTRY_E5_ESC;
		156	name++;
		157	break;
		158	case '\0':
		159	case '.':
		160	d->name[i] = FAT_PAD;
		161	break;
		162	default:
		163	d->name[i] = toupper(*name++);
		164	break;
		165	}
		166	}
		167	if (*name++ != '.')
		168	name = fake_ext;
		169	for (i = 0; i < FAT_EXT_LEN; i++) {
		170	switch ((uint8_t) *name) {
		171	case 0xe5:
		172	d->ext[i] = FAT_DENTRY_E5_ESC;
		173	name++;
		174	break;
		175	case '\0':
		176	d->ext[i] = FAT_PAD;
		177	break;
		178	default:
		179	d->ext[i] = toupper(*name++);
		180	break;
		181	}
		182	}
		183	}
		184
		185	fat_dentry_clsf_t fat_classify_dentry(const fat_dentry_t *d)
		186	{
3505	jermar	187	if (d->attr & FAT_ATTR_VOLLABEL) {
		188	/* volume label entry */
		189	return FAT_DENTRY_SKIP;
		190	}
		191	if (d->name[0] == FAT_DENTRY_ERASED) {
		192	/* not-currently-used entry */
3628	jermar	193	return FAT_DENTRY_FREE;
3505	jermar	194	}
		195	if (d->name[0] == FAT_DENTRY_UNUSED) {
		196	/* never used entry */
		197	return FAT_DENTRY_LAST;
		198	}
		199	if (d->name[0] == FAT_DENTRY_DOT) {
		200	/*
		201	* Most likely '.' or '..'.
		202	* It cannot occur in a regular file name.
		203	*/
		204	return FAT_DENTRY_SKIP;
		205	}
		206	return FAT_DENTRY_VALID;
		207	}
		208
3504	jermar	209	/**
		210	* @}
		211	*/

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(root)//trunk/uspace/srv/fs/fat/fat_dentry.c – Rev 3634