util-linux/volume_id/util.c - codeaurora/busybox - Gitiles

 /*
  * volume_id - reads filesystem label and uuid
  *
  * Copyright (C) 2005 Kay Sievers <kay.sievers@vrfy.org>
  *
  *	This library is free software; you can redistribute it and/or
  *	modify it under the terms of the GNU Lesser General Public
  *	License as published by the Free Software Foundation; either
  *	version 2.1 of the License, or (at your option) any later version.
  *
  *	This library is distributed in the hope that it will be useful,
  *	but WITHOUT ANY WARRANTY; without even the implied warranty of
  *	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  *	Lesser General Public License for more details.
  *
  *	You should have received a copy of the GNU Lesser General Public
  *	License along with this library; if not, write to the Free Software
  *	Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  */

 #include "volume_id_internal.h"

 void volume_id_set_unicode16(char *str, size_t len, const uint8_t *buf, enum endian endianess, size_t count)
 {
 	unsigned i, j;
 	unsigned c;

 	j = 0;
 	for (i = 0; i + 2 <= count; i += 2) {
 		if (endianess == LE)
 			c = (buf[i+1] << 8) | buf[i];
 		else
 			c = (buf[i] << 8) | buf[i+1];
 		if (c == 0) {
 			str[j] = '\0';
 			break;
 		} else if (c < 0x80) {
 			if (j+1 >= len)
 				break;
 			str[j++] = (uint8_t) c;
 		} else if (c < 0x800) {
 			if (j+2 >= len)
 				break;
 			str[j++] = (uint8_t) (0xc0 | (c >> 6));
 			str[j++] = (uint8_t) (0x80 | (c & 0x3f));
 		} else {
 			if (j+3 >= len)
 				break;
 			str[j++] = (uint8_t) (0xe0 | (c >> 12));
 			str[j++] = (uint8_t) (0x80 | ((c >> 6) & 0x3f));
 			str[j++] = (uint8_t) (0x80 | (c & 0x3f));
 		}
 	}
 	str[j] = '\0';
 }

 #ifdef UNUSED
 static const char *usage_to_string(enum volume_id_usage usage_id)
 {
 	switch (usage_id) {
 	case VOLUME_ID_FILESYSTEM:
 		return "filesystem";
 	case VOLUME_ID_PARTITIONTABLE:
 		return "partitiontable";
 	case VOLUME_ID_OTHER:
 		return "other";
 	case VOLUME_ID_RAID:
 		return "raid";
 	case VOLUME_ID_DISKLABEL:
 		return "disklabel";
 	case VOLUME_ID_CRYPTO:
 		return "crypto";
 	case VOLUME_ID_UNPROBED:
 		return "unprobed";
 	case VOLUME_ID_UNUSED:
 		return "unused";
 	}
 	return NULL;
 }

 void volume_id_set_usage_part(struct volume_id_partition *part, enum volume_id_usage usage_id)
 {
 	part->usage_id = usage_id;
 	part->usage = usage_to_string(usage_id);
 }

 void volume_id_set_usage(struct volume_id *id, enum volume_id_usage usage_id)
 {
 	id->usage_id = usage_id;
 	id->usage = usage_to_string(usage_id);
 }

 void volume_id_set_label_raw(struct volume_id *id, const uint8_t *buf, size_t count)
 {
 	memcpy(id->label_raw, buf, count);
 	id->label_raw_len = count;
 }
 #endif

 #ifdef NOT_NEEDED
 static size_t strnlen(const char *s, size_t maxlen)
 {
 	size_t i;
 	if (!maxlen) return 0;
 	if (!s) return 0;
 	for (i = 0; *s && i < maxlen; ++s) ++i;
 	return i;
 }
 #endif

 void volume_id_set_label_string(struct volume_id *id, const uint8_t *buf, size_t count)
 {
 	unsigned i;

 	memcpy(id->label, buf, count);

 	/* remove trailing whitespace */
 	i = strnlen(id->label, count);
 	while (i--) {
 		if (!isspace(id->label[i]))
 			break;
 	}
 	id->label[i+1] = '\0';
 }

 void volume_id_set_label_unicode16(struct volume_id *id, const uint8_t *buf, enum endian endianess, size_t count)
 {
 	 volume_id_set_unicode16(id->label, sizeof(id->label), buf, endianess, count);
 }

 void volume_id_set_uuid(struct volume_id *id, const uint8_t *buf, enum uuid_format format)
 {
 	unsigned i;
 	unsigned count = 0;

 	switch (format) {
 	case UUID_DOS:
 		count = 4;
 		break;
 	case UUID_NTFS:
 	case UUID_HFS:
 		count = 8;
 		break;
 	case UUID_DCE:
 		count = 16;
 		break;
 	case UUID_DCE_STRING:
 		/* 36 is ok, id->uuid has one extra byte for NUL */
 		count = VOLUME_ID_UUID_SIZE;
 		break;
 	}
 //	memcpy(id->uuid_raw, buf, count);
 //	id->uuid_raw_len = count;

 	/* if set, create string in the same format, the native platform uses */
 	for (i = 0; i < count; i++)
 		if (buf[i] != 0)
 			goto set;
 	return; /* all bytes are zero, leave it empty ("") */

 set:
 	switch (format) {
 	case UUID_DOS:
 		sprintf(id->uuid, "%02X%02X-%02X%02X",
 			buf[3], buf[2], buf[1], buf[0]);
 		break;
 	case UUID_NTFS:
 		sprintf(id->uuid, "%02X%02X%02X%02X%02X%02X%02X%02X",
 			buf[7], buf[6], buf[5], buf[4],
 			buf[3], buf[2], buf[1], buf[0]);
 		break;
 	case UUID_HFS:
 		sprintf(id->uuid, "%02X%02X%02X%02X%02X%02X%02X%02X",
 			buf[0], buf[1], buf[2], buf[3],
 			buf[4], buf[5], buf[6], buf[7]);
 		break;
 	case UUID_DCE:
 		sprintf(id->uuid,
 			"%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
 			buf[0], buf[1], buf[2], buf[3],
 			buf[4], buf[5],
 			buf[6], buf[7],
 			buf[8], buf[9],
 			buf[10], buf[11], buf[12], buf[13], buf[14], buf[15]);
 		break;
 	case UUID_DCE_STRING:
 		memcpy(id->uuid, buf, count);
 		id->uuid[count] = '\0';
 		break;
 	}
 }

 /* Do not use xlseek here. With it, single corrupted filesystem
  * may result in attempt to seek past device -> exit.
  * It's better to ignore such fs and continue.  */
 void *volume_id_get_buffer(struct volume_id *id, uint64_t off, size_t len)
 {
 	uint8_t *dst;
 	unsigned small_off;
 	ssize_t read_len;

 	dbg("get buffer off 0x%llx(%llu), len 0x%zx",
 		(unsigned long long) off, (unsigned long long) off, len);

 	/* check if requested area fits in superblock buffer */
 	if (off + len <= SB_BUFFER_SIZE
 	 /* && off <= SB_BUFFER_SIZE - want this paranoid overflow check? */
 	) {
 		if (id->sbbuf == NULL) {
 			id->sbbuf = xmalloc(SB_BUFFER_SIZE);
 		}
 		small_off = off;
 		dst = id->sbbuf;

 		/* check if we need to read */
 		len += off;
 		if (len <= id->sbbuf_len)
 			goto ret; /* we already have it */

 		dbg("read sbbuf len:0x%x", (unsigned) len);
 		id->sbbuf_len = len;
 		off = 0;
 		goto do_read;
 	}

 	if (len > SEEK_BUFFER_SIZE) {
 		dbg("seek buffer too small %d", SEEK_BUFFER_SIZE);
 		return NULL;
 	}
 	dst = id->seekbuf;

 	/* check if we need to read */
 	if ((off >= id->seekbuf_off)
 	 && ((off + len) <= (id->seekbuf_off + id->seekbuf_len))
 	) {
 		small_off = off - id->seekbuf_off; /* can't overflow */
 		goto ret; /* we already have it */
 	}

 	id->seekbuf_off = off;
 	id->seekbuf_len = len;
 	id->seekbuf = xrealloc(id->seekbuf, len);
 	small_off = 0;
 	dst = id->seekbuf;
 	dbg("read seekbuf off:0x%llx len:0x%zx",
 				(unsigned long long) off, len);
  do_read:
 	if (lseek(id->fd, off, SEEK_SET) != off) {
 		dbg("seek(0x%llx) failed", (unsigned long long) off);
 		goto err;
 	}
 	read_len = full_read(id->fd, dst, len);
 	if (read_len != len) {
 		dbg("requested 0x%x bytes, got 0x%x bytes",
 				(unsigned) len, (unsigned) read_len);
  err:
 		/* No filesystem can be this tiny. It's most likely
 		 * non-associated loop device, empty drive and so on.
 		 * Flag it, making it possible to short circuit future
 		 * accesses. Rationale:
 		 * users complained of slow blkid due to empty floppy drives.
 		 */
 		if (off < 64*1024)
 			id->error = 1;
 		/* id->seekbuf_len or id->sbbuf_len is wrong now! Fixing. */
 		volume_id_free_buffer(id);
 		return NULL;
 	}
  ret:
 	return dst + small_off;
 }

 void volume_id_free_buffer(struct volume_id *id)
 {
 	free(id->sbbuf);
 	id->sbbuf = NULL;
 	id->sbbuf_len = 0;
 	free(id->seekbuf);
 	id->seekbuf = NULL;
 	id->seekbuf_len = 0;
 	id->seekbuf_off = 0; /* paranoia */
 }
	/*
	* volume_id - reads filesystem label and uuid
	*
	* Copyright (C) 2005 Kay Sievers <kay.sievers@vrfy.org>
	*
	* This library is free software; you can redistribute it and/or
	* modify it under the terms of the GNU Lesser General Public
	* License as published by the Free Software Foundation; either
	* version 2.1 of the License, or (at your option) any later version.
	*
	* This library is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	* Lesser General Public License for more details.
	*
	* You should have received a copy of the GNU Lesser General Public
	* License along with this library; if not, write to the Free Software
	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	*/

	#include "volume_id_internal.h"

	void volume_id_set_unicode16(char str, size_t len, const uint8_t buf, enum endian endianess, size_t count)
	{
	unsigned i, j;
	unsigned c;

	j = 0;
	for (i = 0; i + 2 <= count; i += 2) {
	if (endianess == LE)
	c = (buf[i+1] << 8) \| buf[i];
	else
	c = (buf[i] << 8) \| buf[i+1];
	if (c == 0) {
	str[j] = '\0';
	break;
	} else if (c < 0x80) {
	if (j+1 >= len)
	break;
	str[j++] = (uint8_t) c;
	} else if (c < 0x800) {
	if (j+2 >= len)
	break;
	str[j++] = (uint8_t) (0xc0 \| (c >> 6));
	str[j++] = (uint8_t) (0x80 \| (c & 0x3f));
	} else {
	if (j+3 >= len)
	break;
	str[j++] = (uint8_t) (0xe0 \| (c >> 12));
	str[j++] = (uint8_t) (0x80 \| ((c >> 6) & 0x3f));
	str[j++] = (uint8_t) (0x80 \| (c & 0x3f));
	}
	}
	str[j] = '\0';
	}

	#ifdef UNUSED
	static const char *usage_to_string(enum volume_id_usage usage_id)
	{
	switch (usage_id) {
	case VOLUME_ID_FILESYSTEM:
	return "filesystem";
	case VOLUME_ID_PARTITIONTABLE:
	return "partitiontable";
	case VOLUME_ID_OTHER:
	return "other";
	case VOLUME_ID_RAID:
	return "raid";
	case VOLUME_ID_DISKLABEL:
	return "disklabel";
	case VOLUME_ID_CRYPTO:
	return "crypto";
	case VOLUME_ID_UNPROBED:
	return "unprobed";
	case VOLUME_ID_UNUSED:
	return "unused";
	}
	return NULL;
	}

	void volume_id_set_usage_part(struct volume_id_partition *part, enum volume_id_usage usage_id)
	{
	part->usage_id = usage_id;
	part->usage = usage_to_string(usage_id);
	}

	void volume_id_set_usage(struct volume_id *id, enum volume_id_usage usage_id)
	{
	id->usage_id = usage_id;
	id->usage = usage_to_string(usage_id);
	}

	void volume_id_set_label_raw(struct volume_id id, const uint8_t buf, size_t count)
	{
	memcpy(id->label_raw, buf, count);
	id->label_raw_len = count;
	}
	#endif

	#ifdef NOT_NEEDED
	static size_t strnlen(const char *s, size_t maxlen)
	{
	size_t i;
	if (!maxlen) return 0;
	if (!s) return 0;
	for (i = 0; *s && i < maxlen; ++s) ++i;
	return i;
	}
	#endif

	void volume_id_set_label_string(struct volume_id id, const uint8_t buf, size_t count)
	{
	unsigned i;

	memcpy(id->label, buf, count);

	/* remove trailing whitespace */
	i = strnlen(id->label, count);
	while (i--) {
	if (!isspace(id->label[i]))
	break;
	}
	id->label[i+1] = '\0';
	}

	void volume_id_set_label_unicode16(struct volume_id id, const uint8_t buf, enum endian endianess, size_t count)
	{
	volume_id_set_unicode16(id->label, sizeof(id->label), buf, endianess, count);
	}

	void volume_id_set_uuid(struct volume_id id, const uint8_t buf, enum uuid_format format)
	{
	unsigned i;
	unsigned count = 0;

	switch (format) {
	case UUID_DOS:
	count = 4;
	break;
	case UUID_NTFS:
	case UUID_HFS:
	count = 8;
	break;
	case UUID_DCE:
	count = 16;
	break;
	case UUID_DCE_STRING:
	/* 36 is ok, id->uuid has one extra byte for NUL */
	count = VOLUME_ID_UUID_SIZE;
	break;
	}
	// memcpy(id->uuid_raw, buf, count);
	// id->uuid_raw_len = count;

	/* if set, create string in the same format, the native platform uses */
	for (i = 0; i < count; i++)
	if (buf[i] != 0)
	goto set;
	return; /* all bytes are zero, leave it empty ("") */

	set:
	switch (format) {
	case UUID_DOS:
	sprintf(id->uuid, "%02X%02X-%02X%02X",
	buf[3], buf[2], buf[1], buf[0]);
	break;
	case UUID_NTFS:
	sprintf(id->uuid, "%02X%02X%02X%02X%02X%02X%02X%02X",
	buf[7], buf[6], buf[5], buf[4],
	buf[3], buf[2], buf[1], buf[0]);
	break;
	case UUID_HFS:
	sprintf(id->uuid, "%02X%02X%02X%02X%02X%02X%02X%02X",
	buf[0], buf[1], buf[2], buf[3],
	buf[4], buf[5], buf[6], buf[7]);
	break;
	case UUID_DCE:
	sprintf(id->uuid,
	"%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
	buf[0], buf[1], buf[2], buf[3],
	buf[4], buf[5],
	buf[6], buf[7],
	buf[8], buf[9],
	buf[10], buf[11], buf[12], buf[13], buf[14], buf[15]);
	break;
	case UUID_DCE_STRING:
	memcpy(id->uuid, buf, count);
	id->uuid[count] = '\0';
	break;
	}
	}

	/* Do not use xlseek here. With it, single corrupted filesystem
	* may result in attempt to seek past device -> exit.
	* It's better to ignore such fs and continue. */
	void volume_id_get_buffer(struct volume_id id, uint64_t off, size_t len)
	{
	uint8_t *dst;
	unsigned small_off;
	ssize_t read_len;

	dbg("get buffer off 0x%llx(%llu), len 0x%zx",
	(unsigned long long) off, (unsigned long long) off, len);

	/* check if requested area fits in superblock buffer */
	if (off + len <= SB_BUFFER_SIZE
	/* && off <= SB_BUFFER_SIZE - want this paranoid overflow check? */
	) {
	if (id->sbbuf == NULL) {
	id->sbbuf = xmalloc(SB_BUFFER_SIZE);
	}
	small_off = off;
	dst = id->sbbuf;

	/* check if we need to read */
	len += off;
	if (len <= id->sbbuf_len)
	goto ret; /* we already have it */

	dbg("read sbbuf len:0x%x", (unsigned) len);
	id->sbbuf_len = len;
	off = 0;
	goto do_read;
	}

	if (len > SEEK_BUFFER_SIZE) {
	dbg("seek buffer too small %d", SEEK_BUFFER_SIZE);
	return NULL;
	}
	dst = id->seekbuf;

	/* check if we need to read */
	if ((off >= id->seekbuf_off)
	&& ((off + len) <= (id->seekbuf_off + id->seekbuf_len))
	) {
	small_off = off - id->seekbuf_off; /* can't overflow */
	goto ret; /* we already have it */
	}

	id->seekbuf_off = off;
	id->seekbuf_len = len;
	id->seekbuf = xrealloc(id->seekbuf, len);
	small_off = 0;
	dst = id->seekbuf;
	dbg("read seekbuf off:0x%llx len:0x%zx",
	(unsigned long long) off, len);
	do_read:
	if (lseek(id->fd, off, SEEK_SET) != off) {
	dbg("seek(0x%llx) failed", (unsigned long long) off);
	goto err;
	}
	read_len = full_read(id->fd, dst, len);
	if (read_len != len) {
	dbg("requested 0x%x bytes, got 0x%x bytes",
	(unsigned) len, (unsigned) read_len);
	err:
	/* No filesystem can be this tiny. It's most likely
	* non-associated loop device, empty drive and so on.
	* Flag it, making it possible to short circuit future
	* accesses. Rationale:
	* users complained of slow blkid due to empty floppy drives.
	*/
	if (off < 64*1024)
	id->error = 1;
	/* id->seekbuf_len or id->sbbuf_len is wrong now! Fixing. */
	volume_id_free_buffer(id);
	return NULL;
	}
	ret:
	return dst + small_off;
	}

	void volume_id_free_buffer(struct volume_id *id)
	{
	free(id->sbbuf);
	id->sbbuf = NULL;
	id->sbbuf_len = 0;
	free(id->seekbuf);
	id->seekbuf = NULL;
	id->seekbuf_len = 0;
	id->seekbuf_off = 0; /* paranoia */
	}