* Copyright (c) 2015 Grzegorz Kostka (kostka.grzegorz@gmail.com)
* Copyright (c) 2015 Kaho Ng (ngkaho1234@gmail.com)
*
- *
- * HelenOS:
- * Copyright (c) 2012 Martin Sucha
- * Copyright (c) 2012 Frantisek Princ
- * All rights reserved.
- *
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
#include "ext4_errno.h"
#include "ext4_blockdev.h"
#include "ext4_super.h"
+#include "ext4_crc32c.h"
#include "ext4_debug.h"
#include "ext4_block_group.h"
#include "ext4_balloc.h"
#include "ext4_inode.h"
-#include "ext4_extent.h"
#include <string.h>
#include <stdlib.h>
header->h_hash = to_le32(hash);
}
+#if CONFIG_META_CSUM_ENABLE
+static uint32_t
+ext4_xattr_block_checksum(struct ext4_inode_ref *inode_ref,
+ ext4_fsblk_t blocknr,
+ struct ext4_xattr_header *header)
+{
+ uint32_t checksum = 0;
+ uint64_t le64_blocknr = blocknr;
+ struct ext4_sblock *sb = &inode_ref->fs->sb;
+
+ if (ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_METADATA_CSUM)) {
+ uint32_t orig_checksum;
+
+ /* Preparation: temporarily set bg checksum to 0 */
+ orig_checksum = header->h_checksum;
+ header->h_checksum = 0;
+ /* First calculate crc32 checksum against fs uuid */
+ checksum = ext4_crc32c(EXT4_CRC32_INIT, sb->uuid,
+ sizeof(sb->uuid));
+ /* Then calculate crc32 checksum block number */
+ checksum = ext4_crc32c(checksum, &le64_blocknr,
+ sizeof(le64_blocknr));
+ /* Finally calculate crc32 checksum against
+ * the entire xattr block */
+ checksum = ext4_crc32c(checksum, header,
+ ext4_sb_get_block_size(sb));
+ header->h_checksum = orig_checksum;
+ }
+ return checksum;
+}
+#else
+#define ext4_xattr_block_checksum(...) 0
+#endif
+
+static void
+ext4_xattr_set_block_checksum(struct ext4_inode_ref *inode_ref,
+ ext4_fsblk_t blocknr __unused,
+ struct ext4_xattr_header *header)
+{
+ struct ext4_sblock *sb = &inode_ref->fs->sb;
+ if (!ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_METADATA_CSUM))
+ return;
+
+ header->h_checksum =
+ ext4_xattr_block_checksum(inode_ref, blocknr, header);
+}
+
static int ext4_xattr_item_cmp(struct ext4_xattr_item *a,
struct ext4_xattr_item *b)
{
int result;
+ if (a->in_inode && !b->in_inode)
+ return -1;
+
+ if (!a->in_inode && b->in_inode)
+ return 1;
+
result = a->name_index - b->name_index;
if (result)
return result;
ext4_xattr_item_cmp, static inline)
static struct ext4_xattr_item *
-ext4_xattr_item_alloc(uint8_t name_index, char *name, size_t name_len)
+ext4_xattr_item_alloc(uint8_t name_index, const char *name, size_t name_len)
{
struct ext4_xattr_item *item;
item = malloc(sizeof(struct ext4_xattr_item) + name_len);
memset(&item->node, 0, sizeof(item->node));
memcpy(item->name, name, name_len);
+ if (name_index == EXT4_XATTR_INDEX_SYSTEM &&
+ name_len == 4 &&
+ !memcmp(name, "data", 4))
+ item->in_inode = true;
+ else
+ item->in_inode = false;
+
return item;
}
static int ext4_xattr_item_alloc_data(struct ext4_xattr_item *item,
- void *orig_data, size_t data_size)
+ const void *orig_data, size_t data_size)
{
void *data = NULL;
ext4_assert(!item->data);
struct ext4_xattr_entry *entry,
bool in_inode)
{
- void *ret;
+ char *ret;
if (in_inode) {
struct ext4_xattr_ibody_header *header;
struct ext4_xattr_entry *first_entry;
- uint16_t inode_size =
+ int16_t inode_size =
ext4_get16(&xattr_ref->fs->sb, inode_size);
header = EXT4_XATTR_IHDR(xattr_ref->inode_ref->inode);
first_entry = EXT4_XATTR_IFIRST(header);
- ret = (void *)((char *)first_entry +
- to_le16(entry->e_value_offs));
- if ((char *)ret +
- EXT4_XATTR_SIZE(to_le32(entry->e_value_size)) -
- (char *)xattr_ref->inode_ref->inode >
- inode_size)
+ ret = ((char *)first_entry + to_le16(entry->e_value_offs));
+ if (ret + EXT4_XATTR_SIZE(to_le32(entry->e_value_size)) -
+ (char *)xattr_ref->inode_ref->inode > inode_size)
ret = NULL;
- } else {
- int32_t block_size = ext4_sb_get_block_size(&xattr_ref->fs->sb);
- ret = (void *)((char *)xattr_ref->block.data +
- to_le16(entry->e_value_offs));
- if ((char *)ret +
- EXT4_XATTR_SIZE(to_le32(entry->e_value_size)) -
- (char *)xattr_ref->block.data >
- block_size)
- ret = NULL;
+ return ret;
+
}
+ int32_t block_size = ext4_sb_get_block_size(&xattr_ref->fs->sb);
+ ret = ((char *)xattr_ref->block.data + to_le16(entry->e_value_offs));
+ if (ret + EXT4_XATTR_SIZE(to_le32(entry->e_value_size)) -
+ (char *)xattr_ref->block.data > block_size)
+ ret = NULL;
return ret;
}
static struct ext4_xattr_item *
ext4_xattr_lookup_item(struct ext4_xattr_ref *xattr_ref, uint8_t name_index,
- char *name, size_t name_len)
+ const char *name, size_t name_len)
{
- struct ext4_xattr_item tmp, *ret;
- tmp.name_index = name_index;
- tmp.name = name;
- tmp.name_len = name_len;
- ret = RB_FIND(ext4_xattr_tree, &xattr_ref->root, &tmp);
- return ret;
+ struct ext4_xattr_item tmp = {
+ .name_index = name_index,
+ .name = (char *)name, /*RB_FIND - won't touch this string*/
+ .name_len = name_len,
+ };
+ if (name_index == EXT4_XATTR_INDEX_SYSTEM &&
+ name_len == 4 &&
+ !memcmp(name, "data", 4))
+ tmp.in_inode = true;
+
+ return RB_FIND(ext4_xattr_tree, &xattr_ref->root, &tmp);
}
static struct ext4_xattr_item *
ext4_xattr_insert_item(struct ext4_xattr_ref *xattr_ref, uint8_t name_index,
- char *name, size_t name_len, void *data,
+ const char *name, size_t name_len, const void *data,
size_t data_size)
{
struct ext4_xattr_item *item;
if (!item)
return NULL;
- if (xattr_ref->ea_size + EXT4_XATTR_SIZE(item->data_size) +
+ if ((xattr_ref->ea_size + EXT4_XATTR_SIZE(data_size) +
+ EXT4_XATTR_LEN(item->name_len)
+ >
+ ext4_xattr_inode_space(xattr_ref) -
+ sizeof(struct ext4_xattr_ibody_header))
+ &&
+ (xattr_ref->ea_size + EXT4_XATTR_SIZE(data_size) +
EXT4_XATTR_LEN(item->name_len) >
- ext4_xattr_inode_space(xattr_ref) +
- ext4_xattr_block_space(xattr_ref)) {
+ ext4_xattr_block_space(xattr_ref) -
+ sizeof(struct ext4_xattr_header))) {
ext4_xattr_item_free(item);
+
return NULL;
}
if (ext4_xattr_item_alloc_data(item, data, data_size) != EOK) {
}
static int ext4_xattr_remove_item(struct ext4_xattr_ref *xattr_ref,
- uint8_t name_index, char *name,
+ uint8_t name_index, const char *name,
size_t name_len)
{
int ret = ENOENT;
xattr_ref->iter_from =
RB_NEXT(ext4_xattr_tree, &xattr_ref->root, item);
- RB_REMOVE(ext4_xattr_tree, &xattr_ref->root, item);
- ext4_xattr_item_free(item);
xattr_ref->ea_size -= EXT4_XATTR_SIZE(item->data_size) +
EXT4_XATTR_LEN(item->name_len);
+
+ RB_REMOVE(ext4_xattr_tree, &xattr_ref->root, item);
+ ext4_xattr_item_free(item);
xattr_ref->dirty = true;
ret = EOK;
}
size_t new_data_size)
{
int ret = EOK;
- if (xattr_ref->ea_size - EXT4_XATTR_SIZE(item->data_size) +
- EXT4_XATTR_SIZE(new_data_size) >
- ext4_xattr_inode_space(xattr_ref) +
- ext4_xattr_block_space(xattr_ref)) {
+ size_t old_data_size = item->data_size;
+ if ((xattr_ref->ea_size - EXT4_XATTR_SIZE(old_data_size) +
+ EXT4_XATTR_SIZE(new_data_size)
+ >
+ ext4_xattr_inode_space(xattr_ref) -
+ sizeof(struct ext4_xattr_ibody_header))
+ &&
+ (xattr_ref->ea_size - EXT4_XATTR_SIZE(old_data_size) +
+ EXT4_XATTR_SIZE(new_data_size)
+ >
+ ext4_xattr_block_space(xattr_ref) -
+ sizeof(struct ext4_xattr_header))) {
return ENOSPC;
}
if (ret != EOK) {
return ret;
}
- xattr_ref->ea_size -=
- EXT4_XATTR_SIZE(item->data_size) + EXT4_XATTR_SIZE(new_data_size);
+ xattr_ref->ea_size =
+ xattr_ref->ea_size -
+ EXT4_XATTR_SIZE(old_data_size) +
+ EXT4_XATTR_SIZE(new_data_size);
xattr_ref->dirty = true;
return ret;
}
static void ext4_xattr_purge_items(struct ext4_xattr_ref *xattr_ref)
{
struct ext4_xattr_item *item, *save_item;
- uint64_t xattr_block = ext4_inode_get_file_acl(
- xattr_ref->inode_ref->inode, &xattr_ref->fs->sb);
RB_FOREACH_SAFE(item, ext4_xattr_tree, &xattr_ref->root, save_item)
{
RB_REMOVE(ext4_xattr_tree, &xattr_ref->root, item);
ext4_xattr_item_free(item);
}
xattr_ref->ea_size = 0;
- if (xattr_block)
- xattr_ref->ea_size += sizeof(struct ext4_xattr_header);
-
- if (ext4_xattr_inode_space(xattr_ref) >
- sizeof(struct ext4_xattr_ibody_header))
- xattr_ref->ea_size += sizeof(struct ext4_xattr_ibody_header);
}
static int ext4_xattr_try_alloc_block(struct ext4_xattr_ref *xattr_ref)
{
int ret = EOK;
- uint64_t xattr_block = 0;
+ ext4_fsblk_t xattr_block = 0;
xattr_block = ext4_inode_get_file_acl(xattr_ref->inode_ref->inode,
&xattr_ref->fs->sb);
if (!xattr_block) {
+ ext4_fsblk_t goal =
+ ext4_fs_inode_to_goal_block(xattr_ref->inode_ref);
+
ret = ext4_balloc_alloc_block(xattr_ref->inode_ref,
- (uint32_t *)&xattr_block);
+ goal,
+ &xattr_block);
if (ret != EOK)
goto Finish;
&xattr_ref->fs->sb, xattr_block);
xattr_ref->inode_ref->dirty = true;
xattr_ref->block_loaded = true;
- xattr_ref->ea_size += sizeof(struct ext4_xattr_header);
}
Finish:
static void ext4_xattr_try_free_block(struct ext4_xattr_ref *xattr_ref)
{
- uint64_t xattr_block;
+ ext4_fsblk_t xattr_block;
xattr_block = ext4_inode_get_file_acl(xattr_ref->inode_ref->inode,
&xattr_ref->fs->sb);
ext4_inode_set_file_acl(xattr_ref->inode_ref->inode, &xattr_ref->fs->sb,
ext4_balloc_free_block(xattr_ref->inode_ref, xattr_block);
xattr_ref->inode_ref->dirty = true;
xattr_ref->block_loaded = false;
- xattr_ref->ea_size -= sizeof(struct ext4_xattr_header);
}
static void ext4_xattr_set_block_header(struct ext4_xattr_ref *xattr_ref)
{
int ret = EOK;
bool block_modified = false;
- void *ibody_data, *block_data;
+ void *ibody_data = NULL;
+ void *block_data = NULL;
struct ext4_xattr_item *item, *save_item;
size_t inode_size_rem, block_size_rem;
struct ext4_xattr_ibody_header *ibody_header = NULL;
entry = EXT4_XATTR_IFIRST(ibody_header);
}
- if (xattr_ref->dirty) {
- /* If there are enough spaces in the ibody EA table.*/
- if (inode_size_rem > sizeof(struct ext4_xattr_ibody_header)) {
- memset(ibody_header, 0, inode_size_rem);
- ibody_header->h_magic = EXT4_XATTR_MAGIC;
- ibody_data = (char *)ibody_header + inode_size_rem;
- inode_size_rem -=
- sizeof(struct ext4_xattr_ibody_header);
+ if (!xattr_ref->dirty)
+ goto Finish;
+ /* If there are enough spaces in the ibody EA table.*/
+ if (inode_size_rem > sizeof(struct ext4_xattr_ibody_header)) {
+ memset(ibody_header, 0, inode_size_rem);
+ ibody_header->h_magic = EXT4_XATTR_MAGIC;
+ ibody_data = (char *)ibody_header + inode_size_rem;
+ inode_size_rem -= sizeof(struct ext4_xattr_ibody_header);
- xattr_ref->inode_ref->dirty = true;
+ xattr_ref->inode_ref->dirty = true;
+ }
+ /* If we need an extra block to hold the EA entries*/
+ if (xattr_ref->ea_size > inode_size_rem) {
+ if (!xattr_ref->block_loaded) {
+ ret = ext4_xattr_try_alloc_block(xattr_ref);
+ if (ret != EOK)
+ goto Finish;
}
- /* If we need an extra block to hold the EA entries*/
- if (xattr_ref->ea_size > inode_size_rem) {
- if (!xattr_ref->block_loaded) {
- ret = ext4_xattr_try_alloc_block(xattr_ref);
- if (ret != EOK)
- goto Finish;
- }
+ block_header = EXT4_XATTR_BHDR(&xattr_ref->block);
+ block_entry = EXT4_XATTR_BFIRST(&xattr_ref->block);
+ ext4_xattr_set_block_header(xattr_ref);
+ block_data = (char *)block_header + block_size_rem;
+ block_size_rem -= sizeof(struct ext4_xattr_header);
+
+ ext4_bcache_set_dirty(xattr_ref->block.buf);
+ } else {
+ /* We don't need an extra block.*/
+ if (xattr_ref->block_loaded) {
block_header = EXT4_XATTR_BHDR(&xattr_ref->block);
- block_entry = EXT4_XATTR_BFIRST(&xattr_ref->block);
- ext4_xattr_set_block_header(xattr_ref);
- block_data = (char *)block_header + block_size_rem;
- block_size_rem -= sizeof(struct ext4_xattr_header);
-
- xattr_ref->block.dirty = true;
- } else {
- /* We don't need an extra block.*/
- if (xattr_ref->block_loaded) {
- block_header =
- EXT4_XATTR_BHDR(&xattr_ref->block);
- block_header->h_refcount = to_le32(
- to_le32(block_header->h_refcount) - 1);
- if (!block_header->h_refcount) {
- ext4_xattr_try_free_block(xattr_ref);
- block_header = NULL;
- } else {
- block_entry = EXT4_XATTR_BFIRST(
- &xattr_ref->block);
- block_data = (char *)block_header +
- block_size_rem;
- block_size_rem -=
- sizeof(struct ext4_xattr_header);
- ext4_inode_set_file_acl(
- xattr_ref->inode_ref->inode,
- &xattr_ref->fs->sb, 0);
-
- xattr_ref->inode_ref->dirty = true;
- xattr_ref->block.dirty = true;
- }
- }
- }
- RB_FOREACH_SAFE(item, ext4_xattr_tree, &xattr_ref->root,
- save_item)
- {
- if (EXT4_XATTR_SIZE(item->data_size) +
- EXT4_XATTR_LEN(item->name_len) <=
- inode_size_rem) {
- ibody_data = (char *)ibody_data -
- EXT4_XATTR_SIZE(item->data_size);
- ext4_xattr_set_inode_entry(item, ibody_header,
- entry, ibody_data);
- memcpy(EXT4_XATTR_NAME(entry), item->name,
- item->name_len);
- memcpy(ibody_data, item->data, item->data_size);
- entry = EXT4_XATTR_NEXT(entry);
- inode_size_rem -=
- EXT4_XATTR_SIZE(item->data_size) +
- EXT4_XATTR_LEN(item->name_len);
+ block_header->h_refcount =
+ to_le32(to_le32(block_header->h_refcount) - 1);
+ if (!block_header->h_refcount) {
+ ext4_xattr_try_free_block(xattr_ref);
+ block_header = NULL;
+ } else {
+ block_entry =
+ EXT4_XATTR_BFIRST(&xattr_ref->block);
+ block_data =
+ (char *)block_header + block_size_rem;
+ block_size_rem -=
+ sizeof(struct ext4_xattr_header);
+ ext4_inode_set_file_acl(
+ xattr_ref->inode_ref->inode,
+ &xattr_ref->fs->sb, 0);
xattr_ref->inode_ref->dirty = true;
- continue;
+ ext4_bcache_set_dirty(xattr_ref->block.buf);
}
- if (EXT4_XATTR_SIZE(item->data_size) +
- EXT4_XATTR_LEN(item->name_len) >
- block_size_rem) {
- ret = ENOSPC;
- goto Finish;
- }
- block_data = (char *)block_data -
+ }
+ }
+ RB_FOREACH_SAFE(item, ext4_xattr_tree, &xattr_ref->root, save_item)
+ {
+ if (EXT4_XATTR_SIZE(item->data_size) +
+ EXT4_XATTR_LEN(item->name_len) <=
+ inode_size_rem) {
+ ibody_data = (char *)ibody_data -
EXT4_XATTR_SIZE(item->data_size);
- ext4_xattr_set_block_entry(item, block_header,
- block_entry, block_data);
- memcpy(EXT4_XATTR_NAME(block_entry), item->name,
+ ext4_xattr_set_inode_entry(item, ibody_header, entry,
+ ibody_data);
+ memcpy(EXT4_XATTR_NAME(entry), item->name,
item->name_len);
- memcpy(block_data, item->data, item->data_size);
- block_entry = EXT4_XATTR_NEXT(block_entry);
- block_size_rem -= EXT4_XATTR_SIZE(item->data_size) +
+ memcpy(ibody_data, item->data, item->data_size);
+ entry = EXT4_XATTR_NEXT(entry);
+ inode_size_rem -= EXT4_XATTR_SIZE(item->data_size) +
EXT4_XATTR_LEN(item->name_len);
- block_modified = true;
+ xattr_ref->inode_ref->dirty = true;
+ continue;
}
- xattr_ref->dirty = false;
- if (block_modified) {
- ext4_xattr_rehash(block_header,
- EXT4_XATTR_BFIRST(&xattr_ref->block));
- xattr_ref->block.dirty = true;
+ if (EXT4_XATTR_SIZE(item->data_size) +
+ EXT4_XATTR_LEN(item->name_len) >
+ block_size_rem) {
+ ret = ENOSPC;
+ goto Finish;
}
+ block_data =
+ (char *)block_data - EXT4_XATTR_SIZE(item->data_size);
+ ext4_xattr_set_block_entry(item, block_header, block_entry,
+ block_data);
+ memcpy(EXT4_XATTR_NAME(block_entry), item->name,
+ item->name_len);
+ memcpy(block_data, item->data, item->data_size);
+ block_entry = EXT4_XATTR_NEXT(block_entry);
+ block_size_rem -= EXT4_XATTR_SIZE(item->data_size) +
+ EXT4_XATTR_LEN(item->name_len);
+
+ block_modified = true;
+ }
+ xattr_ref->dirty = false;
+ if (block_modified) {
+ ext4_xattr_rehash(block_header,
+ EXT4_XATTR_BFIRST(&xattr_ref->block));
+ ext4_xattr_set_block_checksum(xattr_ref->inode_ref,
+ xattr_ref->block.lb_id,
+ block_header);
+ ext4_bcache_set_dirty(xattr_ref->block.buf);
}
Finish:
}
void ext4_fs_xattr_iterate(struct ext4_xattr_ref *ref,
- int(iter)(struct ext4_xattr_ref *ref,
+ int (*iter)(struct ext4_xattr_ref *ref,
struct ext4_xattr_item *item))
{
struct ext4_xattr_item *item;
}
int ext4_fs_set_xattr(struct ext4_xattr_ref *ref, uint8_t name_index,
- char *name, size_t name_len, void *data, size_t data_size,
- bool replace)
+ const char *name, size_t name_len, const void *data,
+ size_t data_size, bool replace)
{
int ret = EOK;
struct ext4_xattr_item *item =
ext4_xattr_lookup_item(ref, name_index, name, name_len);
if (replace) {
if (!item) {
- ret = ENOATTR;
+ ret = ENODATA;
goto Finish;
}
if (item->data_size != data_size)
}
int ext4_fs_remove_xattr(struct ext4_xattr_ref *ref, uint8_t name_index,
- char *name, size_t name_len)
+ const char *name, size_t name_len)
{
return ext4_xattr_remove_item(ref, name_index, name, name_len);
}
int ext4_fs_get_xattr(struct ext4_xattr_ref *ref, uint8_t name_index,
- char *name, size_t name_len, void *buf, size_t buf_size,
- size_t *size_got)
+ const char *name, size_t name_len, void *buf, size_t buf_size,
+ size_t *data_size)
{
int ret = EOK;
size_t item_size = 0;
ext4_xattr_lookup_item(ref, name_index, name, name_len);
if (!item) {
- ret = ENOATTR;
+ ret = ENODATA;
goto Finish;
}
item_size = item->data_size;
memcpy(buf, item->data, buf_size);
Finish:
- if (size_got)
- *size_got = buf_size;
+ if (data_size)
+ *data_size = item_size;
return ret;
}
struct ext4_xattr_ref *ref)
{
int rc;
- uint64_t xattr_block;
+ ext4_fsblk_t xattr_block;
xattr_block = ext4_inode_get_file_acl(inode_ref->inode, &fs->sb);
RB_INIT(&ref->root);
ref->ea_size = 0;
if (rc != EOK)
return EIO;
- ref->ea_size += sizeof(struct ext4_xattr_header);
ref->block_loaded = true;
} else
ref->block_loaded = false;
ref->inode_ref = inode_ref;
ref->fs = fs;
- if (ext4_xattr_inode_space(ref) >
- sizeof(struct ext4_xattr_ibody_header))
- ref->ea_size += sizeof(struct ext4_xattr_ibody_header);
-
rc = ext4_xattr_fetch(ref);
if (rc != EOK) {
ext4_xattr_purge_items(ref);
}
struct xattr_prefix {
- char *prefix;
+ const char *prefix;
uint8_t name_index;
-} prefix_tbl[] = {
+};
+
+static const struct xattr_prefix prefix_tbl[] = {
{"user.", EXT4_XATTR_INDEX_USER},
- {"system.", EXT4_XATTR_INDEX_SYSTEM},
{"system.posix_acl_access", EXT4_XATTR_INDEX_POSIX_ACL_ACCESS},
{"system.posix_acl_default", EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT},
+ {"trusted.", EXT4_XATTR_INDEX_TRUSTED},
+ {"security.", EXT4_XATTR_INDEX_SECURITY},
+ {"system.", EXT4_XATTR_INDEX_SYSTEM},
+ {"system.richacl", EXT4_XATTR_INDEX_RICHACL},
{NULL, 0},
};
-char *ext4_extract_xattr_name(char *full_name, size_t full_name_len,
+const char *ext4_extract_xattr_name(const char *full_name, size_t full_name_len,
uint8_t *name_index, size_t *name_len)
{
int i;
ext4_assert(name_index);
- if (!full_name_len)
+ if (!full_name_len) {
+ if (name_len)
+ *name_len = 0;
+
return NULL;
+ }
for (i = 0; prefix_tbl[i].prefix; i++) {
size_t prefix_len = strlen(prefix_tbl[i].prefix);
return NULL;
}
+const char *ext4_get_xattr_name_prefix(uint8_t name_index, size_t *ret_prefix_len)
+{
+ int i;
+
+ for (i = 0; prefix_tbl[i].prefix; i++) {
+ size_t prefix_len = strlen(prefix_tbl[i].prefix);
+ if (prefix_tbl[i].name_index == name_index) {
+ if (ret_prefix_len)
+ *ret_prefix_len = prefix_len;
+
+ return prefix_tbl[i].prefix;
+ }
+ }
+ if (ret_prefix_len)
+ *ret_prefix_len = 0;
+
+ return NULL;
+}
+
/**
* @}
*/