mirror of https://github.com/vivier/EMILE.git
336 lines
10 KiB
C
336 lines
10 KiB
C
/*
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*
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* (c) 2008 Laurent Vivier <Laurent@Vivier.EU>
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*
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*/
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <unistd.h>
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#include <string.h>
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#include <asm/byteorder.h>
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#include "libext2.h"
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#include "ext2_utils.h"
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void ext2_get_super(device_io_t *device, struct ext2_super_block *super)
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{
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device->read_sector(device->data, 2, super, sizeof (*super));
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super->s_inodes_count = __le32_to_cpu(super->s_inodes_count);
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super->s_blocks_count = __le32_to_cpu(super->s_blocks_count);
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super->s_r_blocks_count = __le32_to_cpu(super->s_r_blocks_count);
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super->s_free_blocks_count = __le32_to_cpu(super->s_free_blocks_count);
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super->s_free_inodes_count = __le32_to_cpu(super->s_free_inodes_count);
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super->s_first_data_block = __le32_to_cpu(super->s_first_data_block);
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super->s_log_block_size = __le32_to_cpu(super->s_log_block_size);
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#ifdef CONFIG_E2FSLIBS
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super->s_log_cluster_size = __le32_to_cpu(super->s_log_cluster_size);
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#else
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super->s_log_frag_size = __le32_to_cpu(super->s_log_frag_size);
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#endif
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super->s_blocks_per_group = __le32_to_cpu(super->s_blocks_per_group);
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#ifdef CONFIG_E2FSLIBS
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super->s_clusters_per_group = __le32_to_cpu(super->s_clusters_per_group);
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#else
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super->s_frags_per_group = __le32_to_cpu(super->s_frags_per_group);
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#endif
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super->s_inodes_per_group = __le32_to_cpu(super->s_inodes_per_group);
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super->s_mtime = __le32_to_cpu(super->s_mtime);
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super->s_wtime = __le32_to_cpu(super->s_wtime);
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super->s_mnt_count = __le16_to_cpu(super->s_mnt_count);
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super->s_max_mnt_count = __le16_to_cpu(super->s_max_mnt_count);
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super->s_magic = __le16_to_cpu(super->s_magic);
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super->s_state = __le16_to_cpu(super->s_state);
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super->s_errors = __le16_to_cpu(super->s_errors);
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super->s_minor_rev_level = __le16_to_cpu(super->s_minor_rev_level);
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super->s_lastcheck = __le32_to_cpu(super->s_lastcheck);
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super->s_checkinterval = __le32_to_cpu(super->s_checkinterval);
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super->s_creator_os = __le32_to_cpu(super->s_creator_os);
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super->s_rev_level = __le32_to_cpu(super->s_rev_level);
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super->s_def_resuid = __le16_to_cpu(super->s_def_resuid);
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super->s_def_resgid = __le16_to_cpu(super->s_def_resgid);
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super->s_first_ino = __le32_to_cpu(super->s_first_ino);
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super->s_inode_size = __le16_to_cpu(super->s_inode_size);
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super->s_block_group_nr = __le16_to_cpu(super->s_block_group_nr);
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super->s_feature_compat = __le32_to_cpu(super->s_feature_compat);
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super->s_feature_incompat = __le32_to_cpu(super->s_feature_incompat);
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super->s_feature_ro_compat = __le32_to_cpu(super->s_feature_ro_compat);
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super->s_algorithm_usage_bitmap =
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__le32_to_cpu(super->s_algorithm_usage_bitmap);
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super->s_journal_inum = __le32_to_cpu(super->s_journal_inum);
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super->s_journal_dev = __le32_to_cpu(super->s_journal_dev);
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super->s_last_orphan = __le32_to_cpu(super->s_last_orphan);
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super->s_hash_seed[0] = __le32_to_cpu(super->s_hash_seed[0]);
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super->s_hash_seed[1] = __le32_to_cpu(super->s_hash_seed[1]);
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super->s_hash_seed[2] = __le32_to_cpu(super->s_hash_seed[2]);
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super->s_hash_seed[3] = __le32_to_cpu(super->s_hash_seed[3]);
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super->s_default_mount_opts =
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__le32_to_cpu(super->s_default_mount_opts);
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super->s_first_meta_bg = __le32_to_cpu(super->s_first_meta_bg);
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}
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void ext2_read_block(ext2_VOLUME* volume, unsigned int fsblock)
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{
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off_t block;
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int blocksize;
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if (fsblock == volume->current)
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return;
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volume->current = fsblock;
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blocksize = volume->device->get_blocksize(volume->device->data);
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block = fsblock * (EXT2_BLOCK_SIZE(volume->super) / blocksize);
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volume->device->read_sector(volume->device->data, block,
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volume->buffer,
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EXT2_BLOCK_SIZE(volume->super));
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}
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void ext2_get_group_desc(ext2_VOLUME* volume,
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int group_id, struct ext2_group_desc *gdp)
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{
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unsigned int block, offset;
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struct ext2_group_desc *le_gdp;
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block = 1 + volume->super->s_first_data_block;
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block += group_id / EXT2_DESC_PER_BLOCK(volume->super);
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ext2_read_block(volume, block);
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offset = group_id % EXT2_DESC_PER_BLOCK(volume->super);
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offset *= sizeof(*gdp);
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le_gdp = (struct ext2_group_desc *)(volume->buffer + offset);
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gdp->bg_block_bitmap = __le32_to_cpu(le_gdp->bg_block_bitmap);
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gdp->bg_inode_bitmap = __le32_to_cpu(le_gdp->bg_inode_bitmap);
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gdp->bg_inode_table = __le32_to_cpu(le_gdp->bg_inode_table);
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gdp->bg_free_blocks_count = __le16_to_cpu(le_gdp->bg_free_blocks_count);
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gdp->bg_free_inodes_count = __le16_to_cpu(le_gdp->bg_free_inodes_count);
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gdp->bg_used_dirs_count = __le16_to_cpu(le_gdp->bg_used_dirs_count);
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}
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int ext2_get_inode(ext2_VOLUME* volume,
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unsigned int ino, struct ext2_inode *inode)
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{
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struct ext2_group_desc desc;
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unsigned int block;
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unsigned int group_id;
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unsigned int offset;
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struct ext2_inode *le_inode;
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int i;
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ino--;
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group_id = ino / EXT2_INODES_PER_GROUP(volume->super);
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ext2_get_group_desc(volume, group_id, &desc);
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ino %= EXT2_INODES_PER_GROUP(volume->super);
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block = desc.bg_inode_table;
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block += ino / (EXT2_BLOCK_SIZE(volume->super) /
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EXT2_INODE_SIZE(volume->super));
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ext2_read_block(volume, block);
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offset = ino % (EXT2_BLOCK_SIZE(volume->super) /
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EXT2_INODE_SIZE(volume->super));
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offset *= EXT2_INODE_SIZE(volume->super);
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le_inode = (struct ext2_inode *)(volume->buffer + offset);
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inode->i_mode = __le16_to_cpu(le_inode->i_mode);
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inode->i_uid = __le16_to_cpu(le_inode->i_uid);
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inode->i_size = __le32_to_cpu(le_inode->i_size);
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inode->i_atime = __le32_to_cpu(le_inode->i_atime);
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inode->i_ctime = __le32_to_cpu(le_inode->i_ctime);
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inode->i_mtime = __le32_to_cpu(le_inode->i_mtime);
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inode->i_dtime = __le32_to_cpu(le_inode->i_dtime);
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inode->i_gid = __le16_to_cpu(le_inode->i_gid);
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inode->i_links_count = __le16_to_cpu(le_inode->i_links_count);
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inode->i_blocks = __le32_to_cpu(le_inode->i_blocks);
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inode->i_flags = __le32_to_cpu(le_inode->i_flags);
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if (S_ISLNK(inode->i_mode)) {
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memcpy(inode->i_block, le_inode->i_block, EXT2_N_BLOCKS * 4);
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} else {
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for (i = 0; i < EXT2_N_BLOCKS; i++)
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inode->i_block[i] = __le32_to_cpu(le_inode->i_block[i]);
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}
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inode->i_generation = __le32_to_cpu(le_inode->i_generation);
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inode->i_file_acl = __le32_to_cpu(le_inode->i_file_acl);
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inode->i_dir_acl = __le32_to_cpu(le_inode->i_dir_acl);
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inode->i_faddr = __le32_to_cpu(le_inode->i_faddr);
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#ifdef CONFIG_E2FSLIBS
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inode->osd2.linux2.l_i_blocks_hi =
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__le16_to_cpu(le_inode->osd2.linux2.l_i_blocks_hi);
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inode->osd2.linux2.l_i_file_acl_high =
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__le16_to_cpu(le_inode->osd2.linux2.l_i_file_acl_high);
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#else
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inode->osd2.linux2.l_i_frag = le_inode->osd2.linux2.l_i_frag;
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inode->osd2.linux2.l_i_fsize = le_inode->osd2.linux2.l_i_fsize;
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#endif
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inode->osd2.linux2.l_i_uid_high =
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__le16_to_cpu(le_inode->osd2.linux2.l_i_uid_high);
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inode->osd2.linux2.l_i_gid_high =
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__le16_to_cpu(le_inode->osd2.linux2.l_i_gid_high);
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#ifdef CONFIG_E2FSLIBS
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#endif
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return 0;
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}
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unsigned int ext2_get_block_addr(ext2_VOLUME* volume, struct ext2_inode *inode,
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unsigned int logical)
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{
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unsigned int physical;
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unsigned int addr_per_block;
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/* direct */
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if (logical < EXT2_NDIR_BLOCKS) {
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physical = inode->i_block[logical];
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return physical;
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}
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/* indirect */
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logical -= EXT2_NDIR_BLOCKS;
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addr_per_block = EXT2_ADDR_PER_BLOCK (volume->super);
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if (logical < addr_per_block) {
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ext2_read_block(volume, inode->i_block[EXT2_IND_BLOCK]);
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physical = __le32_to_cpu(((unsigned int *)volume->buffer)[logical]);
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return physical;
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}
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/* double indirect */
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logical -= addr_per_block;
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if (logical < addr_per_block * addr_per_block) {
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ext2_read_block(volume, inode->i_block[EXT2_DIND_BLOCK]);
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physical = __le32_to_cpu(((unsigned int *)volume->buffer)
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[logical / addr_per_block]);
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ext2_read_block(volume, physical);
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physical = __le32_to_cpu(((unsigned int *)volume->buffer)
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[logical % addr_per_block]);
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return physical;
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}
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/* triple indirect */
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logical -= addr_per_block * addr_per_block;
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ext2_read_block(volume, inode->i_block[EXT2_DIND_BLOCK]);
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physical = __le32_to_cpu(((unsigned int *)volume->buffer)
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[logical / (addr_per_block * addr_per_block)]);
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ext2_read_block(volume, physical);
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logical = logical % (addr_per_block * addr_per_block);
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physical = __le32_to_cpu(((unsigned int *)volume->buffer)[logical / addr_per_block]);
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ext2_read_block(volume, physical);
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physical = __le32_to_cpu(((unsigned int *)volume->buffer)[logical % addr_per_block]);
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return physical;
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}
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int ext2_read_data(ext2_VOLUME* volume, struct ext2_inode *inode,
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off_t offset, char *buffer, size_t length)
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{
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unsigned int logical, physical;
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int blocksize = EXT2_BLOCK_SIZE(volume->super);
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int shift;
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size_t read;
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if (offset >= inode->i_size)
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return -1;
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if (offset + length >= inode->i_size)
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length = inode->i_size - offset;
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read = 0;
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logical = offset / blocksize;
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shift = offset % blocksize;
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if (shift) {
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physical = ext2_get_block_addr(volume, inode, logical);
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ext2_read_block(volume, physical);
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if (length < blocksize - shift) {
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memcpy(buffer, volume->buffer + shift, length);
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return length;
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}
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read += blocksize - shift;
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memcpy(buffer, volume->buffer + shift, read);
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buffer += read;
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length -= read;
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logical++;
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}
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while (length) {
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physical = ext2_get_block_addr(volume, inode, logical);
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ext2_read_block(volume, physical);
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if (length < blocksize) {
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memcpy(buffer, volume->buffer, length);
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read += length;
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return read;
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}
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memcpy(buffer, volume->buffer, blocksize);
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buffer += blocksize;
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length -= blocksize;
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read += blocksize;
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logical++;
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}
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return read;
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}
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off_t ext2_dir_entry(ext2_VOLUME *volume, struct ext2_inode *inode,
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off_t index, struct ext2_dir_entry_2 *entry)
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{
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int ret;
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ret = ext2_read_data(volume, inode, index,
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(char*)entry, sizeof(*entry));
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if (ret == -1)
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return -1;
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entry->inode = __le32_to_cpu(entry->inode);
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entry->rec_len = __le16_to_cpu(entry->rec_len);
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return index + entry->rec_len;
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}
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unsigned int ext2_seek_name(ext2_VOLUME *volume, char *name)
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{
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struct ext2_inode inode;
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int ret;
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unsigned int ino;
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off_t index;
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struct ext2_dir_entry_2 entry;
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ino = EXT2_ROOT_INO;
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while(1) {
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while (*name == '/')
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name++;
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if (!*name)
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break;
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ret = ext2_get_inode(volume, ino, &inode);
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if (ret == -1)
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return 0;
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index = 0;
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while (1) {
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index = ext2_dir_entry(volume, &inode, index, &entry);
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if (index == -1)
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return 0;
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ret = strncmp(name, entry.name, entry.name_len);
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if (ret == 0 &&
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(name[entry.name_len] == 0 ||
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name[entry.name_len] == '/')) {
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ino = entry.inode;
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break;
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}
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}
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name += entry.name_len;
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}
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return ino;
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}
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