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/*
*
* (c) 2008-2009 Laurent Vivier <Laurent@lvivier.info>
*
* This file has been copied from EMILE, http://emile.sf.net
*
*/
#include "libext2.h"
#include "ext2_utils.h"
#include "libopenbios/bindings.h"
#include "libc/diskio.h"
#include "libc/byteorder.h"
int ext2_probe(int fd, long long offset)
{
struct ext2_super_block *super;
super = (struct ext2_super_block*)malloc(sizeof(struct ext2_super_block));
seek_io(fd, 2 * 512 + offset);
read_io(fd, super, sizeof (*super));
if (__le16_to_cpu(super->s_magic) != EXT2_SUPER_MAGIC) {
free(super);
return 0;
}
free(super);
return -1;
}
void ext2_get_super(int fd, struct ext2_super_block *super)
{
seek_io(fd, 2 * 512);
read_io(fd, super, sizeof (*super));
super->s_inodes_count = __le32_to_cpu(super->s_inodes_count);
super->s_blocks_count = __le32_to_cpu(super->s_blocks_count);
super->s_r_blocks_count = __le32_to_cpu(super->s_r_blocks_count);
super->s_free_blocks_count = __le32_to_cpu(super->s_free_blocks_count);
super->s_free_inodes_count = __le32_to_cpu(super->s_free_inodes_count);
super->s_first_data_block = __le32_to_cpu(super->s_first_data_block);
super->s_log_block_size = __le32_to_cpu(super->s_log_block_size);
super->s_log_frag_size = __le32_to_cpu(super->s_log_frag_size);
super->s_blocks_per_group = __le32_to_cpu(super->s_blocks_per_group);
super->s_frags_per_group = __le32_to_cpu(super->s_frags_per_group);
super->s_inodes_per_group = __le32_to_cpu(super->s_inodes_per_group);
super->s_mtime = __le32_to_cpu(super->s_mtime);
super->s_wtime = __le32_to_cpu(super->s_wtime);
super->s_mnt_count = __le16_to_cpu(super->s_mnt_count);
super->s_max_mnt_count = __le16_to_cpu(super->s_max_mnt_count);
super->s_magic = __le16_to_cpu(super->s_magic);
super->s_state = __le16_to_cpu(super->s_state);
super->s_errors = __le16_to_cpu(super->s_errors);
super->s_minor_rev_level = __le16_to_cpu(super->s_minor_rev_level);
super->s_lastcheck = __le32_to_cpu(super->s_lastcheck);
super->s_checkinterval = __le32_to_cpu(super->s_checkinterval);
super->s_creator_os = __le32_to_cpu(super->s_creator_os);
super->s_rev_level = __le32_to_cpu(super->s_rev_level);
super->s_def_resuid = __le16_to_cpu(super->s_def_resuid);
super->s_def_resgid = __le16_to_cpu(super->s_def_resgid);
super->s_first_ino = __le32_to_cpu(super->s_first_ino);
super->s_inode_size = __le16_to_cpu(super->s_inode_size);
super->s_block_group_nr = __le16_to_cpu(super->s_block_group_nr);
super->s_feature_compat = __le32_to_cpu(super->s_feature_compat);
super->s_feature_incompat = __le32_to_cpu(super->s_feature_incompat);
super->s_feature_ro_compat = __le32_to_cpu(super->s_feature_ro_compat);
super->s_algorithm_usage_bitmap =
__le32_to_cpu(super->s_algorithm_usage_bitmap);
super->s_journal_inum = __le32_to_cpu(super->s_journal_inum);
super->s_journal_dev = __le32_to_cpu(super->s_journal_dev);
super->s_last_orphan = __le32_to_cpu(super->s_last_orphan);
super->s_hash_seed[0] = __le32_to_cpu(super->s_hash_seed[0]);
super->s_hash_seed[1] = __le32_to_cpu(super->s_hash_seed[1]);
super->s_hash_seed[2] = __le32_to_cpu(super->s_hash_seed[2]);
super->s_hash_seed[3] = __le32_to_cpu(super->s_hash_seed[3]);
super->s_default_mount_opts =
__le32_to_cpu(super->s_default_mount_opts);
super->s_first_meta_bg = __le32_to_cpu(super->s_first_meta_bg);
}
void ext2_read_block(ext2_VOLUME* volume, unsigned int fsblock)
{
long long offset;
if (fsblock == volume->current)
return;
volume->current = fsblock;
offset = fsblock * EXT2_BLOCK_SIZE(volume->super);
seek_io(volume->fd, offset);
read_io(volume->fd, volume->buffer, EXT2_BLOCK_SIZE(volume->super));
}
void ext2_get_group_desc(ext2_VOLUME* volume,
int group_id, struct ext2_group_desc *gdp)
{
unsigned int block, offset;
struct ext2_group_desc *le_gdp;
block = 1 + volume->super->s_first_data_block;
block += group_id / EXT2_DESC_PER_BLOCK(volume->super);
ext2_read_block(volume, block);
offset = group_id % EXT2_DESC_PER_BLOCK(volume->super);
offset *= sizeof(*gdp);
le_gdp = (struct ext2_group_desc *)(volume->buffer + offset);
gdp->bg_block_bitmap = __le32_to_cpu(le_gdp->bg_block_bitmap);
gdp->bg_inode_bitmap = __le32_to_cpu(le_gdp->bg_inode_bitmap);
gdp->bg_inode_table = __le32_to_cpu(le_gdp->bg_inode_table);
gdp->bg_free_blocks_count = __le16_to_cpu(le_gdp->bg_free_blocks_count);
gdp->bg_free_inodes_count = __le16_to_cpu(le_gdp->bg_free_inodes_count);
gdp->bg_used_dirs_count = __le16_to_cpu(le_gdp->bg_used_dirs_count);
}
int ext2_get_inode(ext2_VOLUME* volume,
unsigned int ino, struct ext2_inode *inode)
{
struct ext2_group_desc desc;
unsigned int block;
unsigned int group_id;
unsigned int offset;
struct ext2_inode *le_inode;
int i;
ino--;
group_id = ino / EXT2_INODES_PER_GROUP(volume->super);
ext2_get_group_desc(volume, group_id, &desc);
ino %= EXT2_INODES_PER_GROUP(volume->super);
block = desc.bg_inode_table;
block += ino / (EXT2_BLOCK_SIZE(volume->super) /
EXT2_INODE_SIZE(volume->super));
ext2_read_block(volume, block);
offset = ino % (EXT2_BLOCK_SIZE(volume->super) /
EXT2_INODE_SIZE(volume->super));
offset *= EXT2_INODE_SIZE(volume->super);
le_inode = (struct ext2_inode *)(volume->buffer + offset);
inode->i_mode = __le16_to_cpu(le_inode->i_mode);
inode->i_uid = __le16_to_cpu(le_inode->i_uid);
inode->i_size = __le32_to_cpu(le_inode->i_size);
inode->i_atime = __le32_to_cpu(le_inode->i_atime);
inode->i_ctime = __le32_to_cpu(le_inode->i_ctime);
inode->i_mtime = __le32_to_cpu(le_inode->i_mtime);
inode->i_dtime = __le32_to_cpu(le_inode->i_dtime);
inode->i_gid = __le16_to_cpu(le_inode->i_gid);
inode->i_links_count = __le16_to_cpu(le_inode->i_links_count);
inode->i_blocks = __le32_to_cpu(le_inode->i_blocks);
inode->i_flags = __le32_to_cpu(le_inode->i_flags);
if (S_ISLNK(inode->i_mode)) {
memcpy(inode->i_block, le_inode->i_block, EXT2_N_BLOCKS * 4);
} else {
for (i = 0; i < EXT2_N_BLOCKS; i++)
inode->i_block[i] = __le32_to_cpu(le_inode->i_block[i]);
}
inode->i_generation = __le32_to_cpu(le_inode->i_generation);
inode->i_file_acl = __le32_to_cpu(le_inode->i_file_acl);
inode->i_dir_acl = __le32_to_cpu(le_inode->i_dir_acl);
inode->i_faddr = __le32_to_cpu(le_inode->i_faddr);
inode->osd2.linux2.l_i_frag = le_inode->osd2.linux2.l_i_frag;
inode->osd2.linux2.l_i_fsize = le_inode->osd2.linux2.l_i_fsize;
inode->osd2.linux2.l_i_uid_high =
__le16_to_cpu(le_inode->osd2.linux2.l_i_uid_high);
inode->osd2.linux2.l_i_gid_high =
__le16_to_cpu(le_inode->osd2.linux2.l_i_gid_high);
return 0;
}
unsigned int ext2_get_block_addr(ext2_VOLUME* volume, struct ext2_inode *inode,
unsigned int logical)
{
unsigned int physical;
unsigned int addr_per_block;
/* direct */
if (logical < EXT2_NDIR_BLOCKS) {
physical = inode->i_block[logical];
return physical;
}
/* indirect */
logical -= EXT2_NDIR_BLOCKS;
addr_per_block = EXT2_ADDR_PER_BLOCK (volume->super);
if (logical < addr_per_block) {
ext2_read_block(volume, inode->i_block[EXT2_IND_BLOCK]);
physical = __le32_to_cpu(((unsigned int *)volume->buffer)[logical]);
return physical;
}
/* double indirect */
logical -= addr_per_block;
if (logical < addr_per_block * addr_per_block) {
ext2_read_block(volume, inode->i_block[EXT2_DIND_BLOCK]);
physical = __le32_to_cpu(((unsigned int *)volume->buffer)
[logical / addr_per_block]);
ext2_read_block(volume, physical);
physical = __le32_to_cpu(((unsigned int *)volume->buffer)
[logical % addr_per_block]);
return physical;
}
/* triple indirect */
logical -= addr_per_block * addr_per_block;
ext2_read_block(volume, inode->i_block[EXT2_DIND_BLOCK]);
physical = __le32_to_cpu(((unsigned int *)volume->buffer)
[logical / (addr_per_block * addr_per_block)]);
ext2_read_block(volume, physical);
logical = logical % (addr_per_block * addr_per_block);
physical = __le32_to_cpu(((unsigned int *)volume->buffer)[logical / addr_per_block]);
ext2_read_block(volume, physical);
physical = __le32_to_cpu(((unsigned int *)volume->buffer)[logical % addr_per_block]);
return physical;
}
int ext2_read_data(ext2_VOLUME* volume, struct ext2_inode *inode,
off_t offset, char *buffer, size_t length)
{
unsigned int logical, physical;
int blocksize = EXT2_BLOCK_SIZE(volume->super);
int shift;
size_t read;
if (offset >= inode->i_size)
return -1;
if (offset + length >= inode->i_size)
length = inode->i_size - offset;
read = 0;
logical = offset / blocksize;
shift = offset % blocksize;
if (shift) {
physical = ext2_get_block_addr(volume, inode, logical);
ext2_read_block(volume, physical);
if (length < blocksize - shift) {
memcpy(buffer, volume->buffer + shift, length);
return length;
}
read += blocksize - shift;
memcpy(buffer, volume->buffer + shift, read);
buffer += read;
length -= read;
logical++;
}
while (length) {
physical = ext2_get_block_addr(volume, inode, logical);
ext2_read_block(volume, physical);
if (length < blocksize) {
memcpy(buffer, volume->buffer, length);
read += length;
return read;
}
memcpy(buffer, volume->buffer, blocksize);
buffer += blocksize;
length -= blocksize;
read += blocksize;
logical++;
}
return read;
}
off_t ext2_dir_entry(ext2_VOLUME *volume, struct ext2_inode *inode,
off_t index, struct ext2_dir_entry_2 *entry)
{
int ret;
ret = ext2_read_data(volume, inode, index,
(char*)entry, sizeof(*entry));
if (ret == -1)
return -1;
entry->inode = __le32_to_cpu(entry->inode);
entry->rec_len = __le16_to_cpu(entry->rec_len);
return index + entry->rec_len;
}
unsigned int ext2_seek_name(ext2_VOLUME *volume, const char *name)
{
struct ext2_inode inode;
int ret;
unsigned int ino;
off_t index;
struct ext2_dir_entry_2 entry;
ino = EXT2_ROOT_INO;
while(1) {
while (*name == '\\')
name++;
if (!*name)
break;
ret = ext2_get_inode(volume, ino, &inode);
if (ret == -1)
return 0;
index = 0;
while (1) {
index = ext2_dir_entry(volume, &inode, index, &entry);
if (index == -1)
return 0;
ret = strncmp(name, entry.name, entry.name_len);
if (ret == 0 &&
(name[entry.name_len] == 0 ||
name[entry.name_len] == '\\')) {
ino = entry.inode;
break;
}
}
name += entry.name_len;
}
return ino;
}
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