// SPDX-License-Identifier: GPL-2.0/* * linux/fs/ext4/acl.c * * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de> */ #include <linux/quotaops.h>#include "ext4_jbd2.h"#include "ext4.h"#include "xattr.h"#include "acl.h" /* * Convert from filesystem to in-memory representation. */static struct posix_acl *ext4_acl_from_disk(const void *value, size_t size){	const char *end = (char *)value + size;	int n, count;	struct posix_acl *acl; 	if (!value)		return NULL;	if (size < sizeof(ext4_acl_header))		 return ERR_PTR(-EINVAL);	if (((ext4_acl_header *)value)->a_version !=	    cpu_to_le32(EXT4_ACL_VERSION))		return ERR_PTR(-EINVAL);	value = (char *)value + sizeof(ext4_acl_header);	count = ext4_acl_count(size);	if (count < 0)		return ERR_PTR(-EINVAL);	if (count == 0)		return NULL;	acl = posix_acl_alloc(count, GFP_NOFS);	if (!acl)		return ERR_PTR(-ENOMEM);	for (n = 0; n < count; n++) {		ext4_acl_entry *entry =			(ext4_acl_entry *)value;		if ((char *)value + sizeof(ext4_acl_entry_short) > end)			goto fail;		acl->a_entries[n].e_tag  = le16_to_cpu(entry->e_tag);		acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm); 		switch (acl->a_entries[n].e_tag) {		case ACL_USER_OBJ:		case ACL_GROUP_OBJ:		case ACL_MASK:		case ACL_OTHER:			value = (char *)value +				sizeof(ext4_acl_entry_short);			break; 		case ACL_USER:			value = (char *)value + sizeof(ext4_acl_entry);			if ((char *)value > end)				goto fail;			acl->a_entries[n].e_uid =				make_kuid(&init_user_ns,					  le32_to_cpu(entry->e_id));			break;		case ACL_GROUP:			value = (char *)value + sizeof(ext4_acl_entry);			if ((char *)value > end)				goto fail;			acl->a_entries[n].e_gid =				make_kgid(&init_user_ns,					  le32_to_cpu(entry->e_id));			break; 		default:			goto fail;		}	}	if (value != end)		goto fail;	return acl; fail:	posix_acl_release(acl);	return ERR_PTR(-EINVAL);} /* * Convert from in-memory to filesystem representation. */static void *ext4_acl_to_disk(const struct posix_acl *acl, size_t *size){	ext4_acl_header *ext_acl;	char *e;	size_t n; 	*size = ext4_acl_size(acl->a_count);	ext_acl = kmalloc(sizeof(ext4_acl_header) + acl->a_count *			sizeof(ext4_acl_entry), GFP_NOFS);	if (!ext_acl)		return ERR_PTR(-ENOMEM);	ext_acl->a_version = cpu_to_le32(EXT4_ACL_VERSION);	e = (char *)ext_acl + sizeof(ext4_acl_header);	for (n = 0; n < acl->a_count; n++) {		const struct posix_acl_entry *acl_e = &acl->a_entries[n];		ext4_acl_entry *entry = (ext4_acl_entry *)e;		entry->e_tag  = cpu_to_le16(acl_e->e_tag);		entry->e_perm = cpu_to_le16(acl_e->e_perm);		switch (acl_e->e_tag) {		case ACL_USER:			entry->e_id = cpu_to_le32(				from_kuid(&init_user_ns, acl_e->e_uid));			e += sizeof(ext4_acl_entry);			break;		case ACL_GROUP:			entry->e_id = cpu_to_le32(				from_kgid(&init_user_ns, acl_e->e_gid));			e += sizeof(ext4_acl_entry);			break; 		case ACL_USER_OBJ:		case ACL_GROUP_OBJ:		case ACL_MASK:		case ACL_OTHER:			e += sizeof(ext4_acl_entry_short);			break; 		default:			goto fail;		}	}	return (char *)ext_acl; fail:	kfree(ext_acl);	return ERR_PTR(-EINVAL);} /* * Inode operation get_posix_acl(). * * inode->i_rwsem: don't care */struct posix_acl *ext4_get_acl(struct inode *inode, int type, bool rcu){	int name_index;	char *value = NULL;	struct posix_acl *acl;	int retval; 	if (rcu)		return ERR_PTR(-ECHILD); 	switch (type) {	case ACL_TYPE_ACCESS:		name_index = EXT4_XATTR_INDEX_POSIX_ACL_ACCESS;		break;	case ACL_TYPE_DEFAULT:		name_index = EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT;		break;	default:		BUG();	}	retval = ext4_xattr_get(inode, name_index, "", NULL, 0);	if (retval > 0) {		value = kmalloc(retval, GFP_NOFS);		if (!value)			return ERR_PTR(-ENOMEM);		retval = ext4_xattr_get(inode, name_index, "", value, retval);	}	if (retval > 0)		acl = ext4_acl_from_disk(value, retval);	else if (retval == -ENODATA || retval == -ENOSYS)		acl = NULL;	else		acl = ERR_PTR(retval);	kfree(value); 	return acl;} /* * Set the access or default ACL of an inode. * * inode->i_rwsem: down unless called from ext4_new_inode */static int__ext4_set_acl(handle_t *handle, struct inode *inode, int type,	     struct posix_acl *acl, int xattr_flags){	int name_index;	void *value = NULL;	size_t size = 0;	int error; 	switch (type) {	case ACL_TYPE_ACCESS:		name_index = EXT4_XATTR_INDEX_POSIX_ACL_ACCESS;		break; 	case ACL_TYPE_DEFAULT:		name_index = EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT;		if (!S_ISDIR(inode->i_mode))			return acl ? -EACCES : 0;		break; 	default:		return -EINVAL;	}	if (acl) {		value = ext4_acl_to_disk(acl, &size);		if (IS_ERR(value))			return (int)PTR_ERR(value);	} 	error = ext4_xattr_set_handle(handle, inode, name_index, "",				      value, size, xattr_flags); 	kfree(value);	if (!error)		set_cached_acl(inode, type, acl); 	return error;} intext4_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,	     struct posix_acl *acl, int type){	handle_t *handle;	int error, credits, retries = 0;	size_t acl_size = acl ? ext4_acl_size(acl->a_count) : 0;	struct inode *inode = d_inode(dentry);	umode_t mode = inode->i_mode;	int update_mode = 0; 	error = dquot_initialize(inode);	if (error)		return error;retry:	error = ext4_xattr_set_credits(inode, acl_size, false /* is_create */,				       &credits);	if (error)		return error; 	handle = ext4_journal_start(inode, EXT4_HT_XATTR, credits);	if (IS_ERR(handle))		return PTR_ERR(handle); 	if ((type == ACL_TYPE_ACCESS) && acl) {		error = posix_acl_update_mode(idmap, inode, &mode, &acl);		if (error)			goto out_stop;		if (mode != inode->i_mode)			update_mode = 1;	} 	error = __ext4_set_acl(handle, inode, type, acl, 0 /* xattr_flags */);	if (!error && update_mode) {		inode->i_mode = mode;		inode_set_ctime_current(inode);		error = ext4_mark_inode_dirty(handle, inode);	}out_stop:	ext4_journal_stop(handle);	if (error == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))		goto retry;	return error;} /* * Initialize the ACLs of a new inode. Called from ext4_new_inode. * * dir->i_rwsem: down * inode->i_rwsem: up (access to inode is still exclusive) */intext4_init_acl(handle_t *handle, struct inode *inode, struct inode *dir){	struct posix_acl *default_acl, *acl;	int error; 	error = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl);	if (error)		return error; 	if (default_acl) {		error = __ext4_set_acl(handle, inode, ACL_TYPE_DEFAULT,				       default_acl, XATTR_CREATE);		posix_acl_release(default_acl);	} else {		inode->i_default_acl = NULL;	}	if (acl) {		if (!error)			error = __ext4_set_acl(handle, inode, ACL_TYPE_ACCESS,					       acl, XATTR_CREATE);		posix_acl_release(acl);	} else {		inode->i_acl = NULL;	}	return error;}