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/*
* Copyright (C) 2010 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <sys/stat.h>
#include <string.h>
#include <stdio.h>
#include "ext4_utils.h"
#include "ext4.h"
#include "make_ext4fs.h"
#include "allocate.h"
#include "contents.h"
#include "extent.h"
#include "indirect.h"
#include "xattr.h"
#ifdef USE_MINGW
#define S_IFLNK 0 /* used by make_link, not needed under mingw */
#endif
static u32 dentry_size(u32 entries, struct dentry *dentries)
{
u32 len = 24;
unsigned int i;
unsigned int dentry_len;
for (i = 0; i < entries; i++) {
dentry_len = 8 + ALIGN(strlen(dentries[i].filename), 4);
if (len % info.block_size + dentry_len > info.block_size)
len += info.block_size - (len % info.block_size);
len += dentry_len;
}
return len;
}
static struct ext4_dir_entry_2 *add_dentry(u8 *data, u32 *offset,
struct ext4_dir_entry_2 *prev, u32 inode, const char *name,
u8 file_type)
{
u8 name_len = strlen(name);
u16 rec_len = 8 + ALIGN(name_len, 4);
struct ext4_dir_entry_2 *dentry;
u32 start_block = *offset / info.block_size;
u32 end_block = (*offset + rec_len - 1) / info.block_size;
if (start_block != end_block) {
/* Adding this dentry will cross a block boundary, so pad the previous
dentry to the block boundary */
if (!prev)
critical_error("no prev");
prev->rec_len += end_block * info.block_size - *offset;
*offset = end_block * info.block_size;
}
dentry = (struct ext4_dir_entry_2 *)(data + *offset);
dentry->inode = inode;
dentry->rec_len = rec_len;
dentry->name_len = name_len;
dentry->file_type = file_type;
memcpy(dentry->name, name, name_len);
*offset += rec_len;
return dentry;
}
/* Creates a directory structure for an array of directory entries, dentries,
and stores the location of the structure in an inode. The new inode's
.. link is set to dir_inode_num. Stores the location of the inode number
of each directory entry into dentries[i].inode, to be filled in later
when the inode for the entry is allocated. Returns the inode number of the
new directory */
u32 make_directory(u32 dir_inode_num, u32 entries, struct dentry *dentries,
u32 dirs)
{
struct ext4_inode *inode;
u32 blocks;
u32 len;
u32 offset = 0;
u32 inode_num;
u8 *data;
unsigned int i;
struct ext4_dir_entry_2 *dentry;
blocks = DIV_ROUND_UP(dentry_size(entries, dentries), info.block_size);
len = blocks * info.block_size;
if (dir_inode_num) {
inode_num = allocate_inode(info);
} else {
dir_inode_num = EXT4_ROOT_INO;
inode_num = EXT4_ROOT_INO;
}
if (inode_num == EXT4_ALLOCATE_FAILED) {
error("failed to allocate inode\n");
return EXT4_ALLOCATE_FAILED;
}
add_directory(inode_num);
inode = get_inode(inode_num);
if (inode == NULL) {
error("failed to get inode %u", inode_num);
return EXT4_ALLOCATE_FAILED;
}
data = inode_allocate_data_extents(inode, len, len);
if (data == NULL) {
error("failed to allocate %u extents", len);
return EXT4_ALLOCATE_FAILED;
}
inode->i_mode = S_IFDIR;
inode->i_links_count = dirs + 2;
inode->i_flags |= aux_info.default_i_flags;
dentry = NULL;
dentry = add_dentry(data, &offset, NULL, inode_num, ".", EXT4_FT_DIR);
if (!dentry) {
error("failed to add . directory");
return EXT4_ALLOCATE_FAILED;
}
dentry = add_dentry(data, &offset, dentry, dir_inode_num, "..", EXT4_FT_DIR);
if (!dentry) {
error("failed to add .. directory");
return EXT4_ALLOCATE_FAILED;
}
for (i = 0; i < entries; i++) {
dentry = add_dentry(data, &offset, dentry, 0,
dentries[i].filename, dentries[i].file_type);
if (offset > len || (offset == len && i != entries - 1))
critical_error("internal error: dentry for %s ends at %d, past %d\n",
dentries[i].filename, offset, len);
dentries[i].inode = &dentry->inode;
if (!dentry) {
error("failed to add directory");
return EXT4_ALLOCATE_FAILED;
}
}
/* pad the last dentry out to the end of the block */
dentry->rec_len += len - offset;
return inode_num;
}
/* Creates a file on disk. Returns the inode number of the new file */
u32 make_file(const char *filename, u64 len)
{
struct ext4_inode *inode;
u32 inode_num;
inode_num = allocate_inode(info);
if (inode_num == EXT4_ALLOCATE_FAILED) {
error("failed to allocate inode\n");
return EXT4_ALLOCATE_FAILED;
}
inode = get_inode(inode_num);
if (inode == NULL) {
error("failed to get inode %u", inode_num);
return EXT4_ALLOCATE_FAILED;
}
if (len > 0)
inode_allocate_file_extents(inode, len, filename);
inode->i_mode = S_IFREG;
inode->i_links_count = 1;
inode->i_flags |= aux_info.default_i_flags;
return inode_num;
}
/* Creates a file on disk. Returns the inode number of the new file */
u32 make_link(const char *filename, const char *link)
{
struct ext4_inode *inode;
u32 inode_num;
u32 len = strlen(link);
inode_num = allocate_inode(info);
if (inode_num == EXT4_ALLOCATE_FAILED) {
error("failed to allocate inode\n");
return EXT4_ALLOCATE_FAILED;
}
inode = get_inode(inode_num);
if (inode == NULL) {
error("failed to get inode %u", inode_num);
return EXT4_ALLOCATE_FAILED;
}
inode->i_mode = S_IFLNK;
inode->i_links_count = 1;
inode->i_flags |= aux_info.default_i_flags;
inode->i_size_lo = len;
if (len + 1 <= sizeof(inode->i_block)) {
/* Fast symlink */
memcpy((char*)inode->i_block, link, len);
} else {
u8 *data = inode_allocate_data_indirect(inode, info.block_size, info.block_size);
memcpy(data, link, len);
inode->i_blocks_lo = info.block_size / 512;
}
return inode_num;
}
int inode_set_permissions(u32 inode_num, u16 mode, u16 uid, u16 gid, u32 mtime)
{
struct ext4_inode *inode = get_inode(inode_num);
if (!inode)
return -1;
inode->i_mode |= mode;
inode->i_uid = uid;
inode->i_gid = gid;
inode->i_mtime = mtime;
inode->i_atime = mtime;
inode->i_ctime = mtime;
return 0;
}
#define XATTR_SELINUX_SUFFIX "selinux"
/* XXX */
#define cpu_to_le32(x) (x)
#define cpu_to_le16(x) (x)
int inode_set_selinux(u32 inode_num, const char *secon)
{
struct ext4_inode *inode = get_inode(inode_num);
u32 *hdr;
struct ext4_xattr_entry *entry;
size_t name_len = strlen(XATTR_SELINUX_SUFFIX);
size_t value_len;
size_t size, min_offs;
char *val;
if (!secon)
return 0;
if (!inode)
return -1;
hdr = (u32 *) (inode + 1);
*hdr = cpu_to_le32(EXT4_XATTR_MAGIC);
entry = (struct ext4_xattr_entry *) (hdr+1);
memset(entry, 0, EXT4_XATTR_LEN(name_len));
entry->e_name_index = EXT4_XATTR_INDEX_SECURITY;
entry->e_name_len = name_len;
memcpy(entry->e_name, XATTR_SELINUX_SUFFIX, name_len);
value_len = strlen(secon)+1;
entry->e_value_size = cpu_to_le32(value_len);
min_offs = (char *)inode + info.inode_size - (char*) entry;
size = EXT4_XATTR_SIZE(value_len);
val = (char *)entry + min_offs - size;
entry->e_value_offs = cpu_to_le16(min_offs - size);
memset(val + size - EXT4_XATTR_PAD, 0, EXT4_XATTR_PAD);
memcpy(val, secon, value_len);
inode->i_extra_isize = cpu_to_le16(sizeof(struct ext4_inode) - EXT4_GOOD_OLD_INODE_SIZE);
return 0;
}