| // SPDX-License-Identifier: GPL-2.0 | 
 | /* | 
 |  * fs/f2fs/acl.c | 
 |  * | 
 |  * Copyright (c) 2012 Samsung Electronics Co., Ltd. | 
 |  *             http://www.samsung.com/ | 
 |  * | 
 |  * Portions of this code from linux/fs/ext2/acl.c | 
 |  * | 
 |  * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de> | 
 |  */ | 
 | #include <linux/f2fs_fs.h> | 
 | #include "f2fs.h" | 
 | #include "xattr.h" | 
 | #include "acl.h" | 
 |  | 
 | static inline size_t f2fs_acl_size(int count) | 
 | { | 
 | 	if (count <= 4) { | 
 | 		return sizeof(struct f2fs_acl_header) + | 
 | 			count * sizeof(struct f2fs_acl_entry_short); | 
 | 	} else { | 
 | 		return sizeof(struct f2fs_acl_header) + | 
 | 			4 * sizeof(struct f2fs_acl_entry_short) + | 
 | 			(count - 4) * sizeof(struct f2fs_acl_entry); | 
 | 	} | 
 | } | 
 |  | 
 | static inline int f2fs_acl_count(size_t size) | 
 | { | 
 | 	ssize_t s; | 
 | 	size -= sizeof(struct f2fs_acl_header); | 
 | 	s = size - 4 * sizeof(struct f2fs_acl_entry_short); | 
 | 	if (s < 0) { | 
 | 		if (size % sizeof(struct f2fs_acl_entry_short)) | 
 | 			return -1; | 
 | 		return size / sizeof(struct f2fs_acl_entry_short); | 
 | 	} else { | 
 | 		if (s % sizeof(struct f2fs_acl_entry)) | 
 | 			return -1; | 
 | 		return s / sizeof(struct f2fs_acl_entry) + 4; | 
 | 	} | 
 | } | 
 |  | 
 | static struct posix_acl *f2fs_acl_from_disk(const char *value, size_t size) | 
 | { | 
 | 	int i, count; | 
 | 	struct posix_acl *acl; | 
 | 	struct f2fs_acl_header *hdr = (struct f2fs_acl_header *)value; | 
 | 	struct f2fs_acl_entry *entry = (struct f2fs_acl_entry *)(hdr + 1); | 
 | 	const char *end = value + size; | 
 |  | 
 | 	if (size < sizeof(struct f2fs_acl_header)) | 
 | 		return ERR_PTR(-EINVAL); | 
 |  | 
 | 	if (hdr->a_version != cpu_to_le32(F2FS_ACL_VERSION)) | 
 | 		return ERR_PTR(-EINVAL); | 
 |  | 
 | 	count = f2fs_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 (i = 0; i < count; i++) { | 
 |  | 
 | 		if ((char *)entry > end) | 
 | 			goto fail; | 
 |  | 
 | 		acl->a_entries[i].e_tag  = le16_to_cpu(entry->e_tag); | 
 | 		acl->a_entries[i].e_perm = le16_to_cpu(entry->e_perm); | 
 |  | 
 | 		switch (acl->a_entries[i].e_tag) { | 
 | 		case ACL_USER_OBJ: | 
 | 		case ACL_GROUP_OBJ: | 
 | 		case ACL_MASK: | 
 | 		case ACL_OTHER: | 
 | 			entry = (struct f2fs_acl_entry *)((char *)entry + | 
 | 					sizeof(struct f2fs_acl_entry_short)); | 
 | 			break; | 
 |  | 
 | 		case ACL_USER: | 
 | 			acl->a_entries[i].e_uid = | 
 | 				make_kuid(&init_user_ns, | 
 | 						le32_to_cpu(entry->e_id)); | 
 | 			entry = (struct f2fs_acl_entry *)((char *)entry + | 
 | 					sizeof(struct f2fs_acl_entry)); | 
 | 			break; | 
 | 		case ACL_GROUP: | 
 | 			acl->a_entries[i].e_gid = | 
 | 				make_kgid(&init_user_ns, | 
 | 						le32_to_cpu(entry->e_id)); | 
 | 			entry = (struct f2fs_acl_entry *)((char *)entry + | 
 | 					sizeof(struct f2fs_acl_entry)); | 
 | 			break; | 
 | 		default: | 
 | 			goto fail; | 
 | 		} | 
 | 	} | 
 | 	if ((char *)entry != end) | 
 | 		goto fail; | 
 | 	return acl; | 
 | fail: | 
 | 	posix_acl_release(acl); | 
 | 	return ERR_PTR(-EINVAL); | 
 | } | 
 |  | 
 | static void *f2fs_acl_to_disk(struct f2fs_sb_info *sbi, | 
 | 				const struct posix_acl *acl, size_t *size) | 
 | { | 
 | 	struct f2fs_acl_header *f2fs_acl; | 
 | 	struct f2fs_acl_entry *entry; | 
 | 	int i; | 
 |  | 
 | 	f2fs_acl = f2fs_kmalloc(sbi, sizeof(struct f2fs_acl_header) + | 
 | 			acl->a_count * sizeof(struct f2fs_acl_entry), | 
 | 			GFP_NOFS); | 
 | 	if (!f2fs_acl) | 
 | 		return ERR_PTR(-ENOMEM); | 
 |  | 
 | 	f2fs_acl->a_version = cpu_to_le32(F2FS_ACL_VERSION); | 
 | 	entry = (struct f2fs_acl_entry *)(f2fs_acl + 1); | 
 |  | 
 | 	for (i = 0; i < acl->a_count; i++) { | 
 |  | 
 | 		entry->e_tag  = cpu_to_le16(acl->a_entries[i].e_tag); | 
 | 		entry->e_perm = cpu_to_le16(acl->a_entries[i].e_perm); | 
 |  | 
 | 		switch (acl->a_entries[i].e_tag) { | 
 | 		case ACL_USER: | 
 | 			entry->e_id = cpu_to_le32( | 
 | 					from_kuid(&init_user_ns, | 
 | 						acl->a_entries[i].e_uid)); | 
 | 			entry = (struct f2fs_acl_entry *)((char *)entry + | 
 | 					sizeof(struct f2fs_acl_entry)); | 
 | 			break; | 
 | 		case ACL_GROUP: | 
 | 			entry->e_id = cpu_to_le32( | 
 | 					from_kgid(&init_user_ns, | 
 | 						acl->a_entries[i].e_gid)); | 
 | 			entry = (struct f2fs_acl_entry *)((char *)entry + | 
 | 					sizeof(struct f2fs_acl_entry)); | 
 | 			break; | 
 | 		case ACL_USER_OBJ: | 
 | 		case ACL_GROUP_OBJ: | 
 | 		case ACL_MASK: | 
 | 		case ACL_OTHER: | 
 | 			entry = (struct f2fs_acl_entry *)((char *)entry + | 
 | 					sizeof(struct f2fs_acl_entry_short)); | 
 | 			break; | 
 | 		default: | 
 | 			goto fail; | 
 | 		} | 
 | 	} | 
 | 	*size = f2fs_acl_size(acl->a_count); | 
 | 	return (void *)f2fs_acl; | 
 |  | 
 | fail: | 
 | 	kvfree(f2fs_acl); | 
 | 	return ERR_PTR(-EINVAL); | 
 | } | 
 |  | 
 | static struct posix_acl *__f2fs_get_acl(struct inode *inode, int type, | 
 | 						struct page *dpage) | 
 | { | 
 | 	int name_index = F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT; | 
 | 	void *value = NULL; | 
 | 	struct posix_acl *acl; | 
 | 	int retval; | 
 |  | 
 | 	if (type == ACL_TYPE_ACCESS) | 
 | 		name_index = F2FS_XATTR_INDEX_POSIX_ACL_ACCESS; | 
 |  | 
 | 	retval = f2fs_getxattr(inode, name_index, "", NULL, 0, dpage); | 
 | 	if (retval > 0) { | 
 | 		value = f2fs_kmalloc(F2FS_I_SB(inode), retval, GFP_F2FS_ZERO); | 
 | 		if (!value) | 
 | 			return ERR_PTR(-ENOMEM); | 
 | 		retval = f2fs_getxattr(inode, name_index, "", value, | 
 | 							retval, dpage); | 
 | 	} | 
 |  | 
 | 	if (retval > 0) | 
 | 		acl = f2fs_acl_from_disk(value, retval); | 
 | 	else if (retval == -ENODATA) | 
 | 		acl = NULL; | 
 | 	else | 
 | 		acl = ERR_PTR(retval); | 
 | 	kvfree(value); | 
 |  | 
 | 	return acl; | 
 | } | 
 |  | 
 | struct posix_acl *f2fs_get_acl(struct inode *inode, int type) | 
 | { | 
 | 	return __f2fs_get_acl(inode, type, NULL); | 
 | } | 
 |  | 
 | static int __f2fs_set_acl(struct inode *inode, int type, | 
 | 			struct posix_acl *acl, struct page *ipage) | 
 | { | 
 | 	int name_index; | 
 | 	void *value = NULL; | 
 | 	size_t size = 0; | 
 | 	int error; | 
 | 	umode_t mode = inode->i_mode; | 
 |  | 
 | 	switch (type) { | 
 | 	case ACL_TYPE_ACCESS: | 
 | 		name_index = F2FS_XATTR_INDEX_POSIX_ACL_ACCESS; | 
 | 		if (acl && !ipage) { | 
 | 			error = posix_acl_update_mode(inode, &mode, &acl); | 
 | 			if (error) | 
 | 				return error; | 
 | 			set_acl_inode(inode, mode); | 
 | 		} | 
 | 		break; | 
 |  | 
 | 	case ACL_TYPE_DEFAULT: | 
 | 		name_index = F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT; | 
 | 		if (!S_ISDIR(inode->i_mode)) | 
 | 			return acl ? -EACCES : 0; | 
 | 		break; | 
 |  | 
 | 	default: | 
 | 		return -EINVAL; | 
 | 	} | 
 |  | 
 | 	if (acl) { | 
 | 		value = f2fs_acl_to_disk(F2FS_I_SB(inode), acl, &size); | 
 | 		if (IS_ERR(value)) { | 
 | 			clear_inode_flag(inode, FI_ACL_MODE); | 
 | 			return PTR_ERR(value); | 
 | 		} | 
 | 	} | 
 |  | 
 | 	error = f2fs_setxattr(inode, name_index, "", value, size, ipage, 0); | 
 |  | 
 | 	kvfree(value); | 
 | 	if (!error) | 
 | 		set_cached_acl(inode, type, acl); | 
 |  | 
 | 	clear_inode_flag(inode, FI_ACL_MODE); | 
 | 	return error; | 
 | } | 
 |  | 
 | int f2fs_set_acl(struct inode *inode, struct posix_acl *acl, int type) | 
 | { | 
 | 	if (unlikely(f2fs_cp_error(F2FS_I_SB(inode)))) | 
 | 		return -EIO; | 
 |  | 
 | 	return __f2fs_set_acl(inode, type, acl, NULL); | 
 | } | 
 |  | 
 | /* | 
 |  * Most part of f2fs_acl_clone, f2fs_acl_create_masq, f2fs_acl_create | 
 |  * are copied from posix_acl.c | 
 |  */ | 
 | static struct posix_acl *f2fs_acl_clone(const struct posix_acl *acl, | 
 | 							gfp_t flags) | 
 | { | 
 | 	struct posix_acl *clone = NULL; | 
 |  | 
 | 	if (acl) { | 
 | 		int size = sizeof(struct posix_acl) + acl->a_count * | 
 | 				sizeof(struct posix_acl_entry); | 
 | 		clone = kmemdup(acl, size, flags); | 
 | 		if (clone) | 
 | 			refcount_set(&clone->a_refcount, 1); | 
 | 	} | 
 | 	return clone; | 
 | } | 
 |  | 
 | static int f2fs_acl_create_masq(struct posix_acl *acl, umode_t *mode_p) | 
 | { | 
 | 	struct posix_acl_entry *pa, *pe; | 
 | 	struct posix_acl_entry *group_obj = NULL, *mask_obj = NULL; | 
 | 	umode_t mode = *mode_p; | 
 | 	int not_equiv = 0; | 
 |  | 
 | 	/* assert(atomic_read(acl->a_refcount) == 1); */ | 
 |  | 
 | 	FOREACH_ACL_ENTRY(pa, acl, pe) { | 
 | 		switch (pa->e_tag) { | 
 | 		case ACL_USER_OBJ: | 
 | 			pa->e_perm &= (mode >> 6) | ~S_IRWXO; | 
 | 			mode &= (pa->e_perm << 6) | ~S_IRWXU; | 
 | 			break; | 
 |  | 
 | 		case ACL_USER: | 
 | 		case ACL_GROUP: | 
 | 			not_equiv = 1; | 
 | 			break; | 
 |  | 
 | 		case ACL_GROUP_OBJ: | 
 | 			group_obj = pa; | 
 | 			break; | 
 |  | 
 | 		case ACL_OTHER: | 
 | 			pa->e_perm &= mode | ~S_IRWXO; | 
 | 			mode &= pa->e_perm | ~S_IRWXO; | 
 | 			break; | 
 |  | 
 | 		case ACL_MASK: | 
 | 			mask_obj = pa; | 
 | 			not_equiv = 1; | 
 | 			break; | 
 |  | 
 | 		default: | 
 | 			return -EIO; | 
 | 		} | 
 | 	} | 
 |  | 
 | 	if (mask_obj) { | 
 | 		mask_obj->e_perm &= (mode >> 3) | ~S_IRWXO; | 
 | 		mode &= (mask_obj->e_perm << 3) | ~S_IRWXG; | 
 | 	} else { | 
 | 		if (!group_obj) | 
 | 			return -EIO; | 
 | 		group_obj->e_perm &= (mode >> 3) | ~S_IRWXO; | 
 | 		mode &= (group_obj->e_perm << 3) | ~S_IRWXG; | 
 | 	} | 
 |  | 
 | 	*mode_p = (*mode_p & ~S_IRWXUGO) | mode; | 
 | 	return not_equiv; | 
 | } | 
 |  | 
 | static int f2fs_acl_create(struct inode *dir, umode_t *mode, | 
 | 		struct posix_acl **default_acl, struct posix_acl **acl, | 
 | 		struct page *dpage) | 
 | { | 
 | 	struct posix_acl *p; | 
 | 	struct posix_acl *clone; | 
 | 	int ret; | 
 |  | 
 | 	*acl = NULL; | 
 | 	*default_acl = NULL; | 
 |  | 
 | 	if (S_ISLNK(*mode) || !IS_POSIXACL(dir)) | 
 | 		return 0; | 
 |  | 
 | 	p = __f2fs_get_acl(dir, ACL_TYPE_DEFAULT, dpage); | 
 | 	if (!p || p == ERR_PTR(-EOPNOTSUPP)) { | 
 | 		*mode &= ~current_umask(); | 
 | 		return 0; | 
 | 	} | 
 | 	if (IS_ERR(p)) | 
 | 		return PTR_ERR(p); | 
 |  | 
 | 	clone = f2fs_acl_clone(p, GFP_NOFS); | 
 | 	if (!clone) { | 
 | 		ret = -ENOMEM; | 
 | 		goto release_acl; | 
 | 	} | 
 |  | 
 | 	ret = f2fs_acl_create_masq(clone, mode); | 
 | 	if (ret < 0) | 
 | 		goto release_clone; | 
 |  | 
 | 	if (ret == 0) | 
 | 		posix_acl_release(clone); | 
 | 	else | 
 | 		*acl = clone; | 
 |  | 
 | 	if (!S_ISDIR(*mode)) | 
 | 		posix_acl_release(p); | 
 | 	else | 
 | 		*default_acl = p; | 
 |  | 
 | 	return 0; | 
 |  | 
 | release_clone: | 
 | 	posix_acl_release(clone); | 
 | release_acl: | 
 | 	posix_acl_release(p); | 
 | 	return ret; | 
 | } | 
 |  | 
 | int f2fs_init_acl(struct inode *inode, struct inode *dir, struct page *ipage, | 
 | 							struct page *dpage) | 
 | { | 
 | 	struct posix_acl *default_acl = NULL, *acl = NULL; | 
 | 	int error = 0; | 
 |  | 
 | 	error = f2fs_acl_create(dir, &inode->i_mode, &default_acl, &acl, dpage); | 
 | 	if (error) | 
 | 		return error; | 
 |  | 
 | 	f2fs_mark_inode_dirty_sync(inode, true); | 
 |  | 
 | 	if (default_acl) { | 
 | 		error = __f2fs_set_acl(inode, ACL_TYPE_DEFAULT, default_acl, | 
 | 				       ipage); | 
 | 		posix_acl_release(default_acl); | 
 | 	} else { | 
 | 		inode->i_default_acl = NULL; | 
 | 	} | 
 | 	if (acl) { | 
 | 		if (!error) | 
 | 			error = __f2fs_set_acl(inode, ACL_TYPE_ACCESS, acl, | 
 | 					       ipage); | 
 | 		posix_acl_release(acl); | 
 | 	} else { | 
 | 		inode->i_acl = NULL; | 
 | 	} | 
 |  | 
 | 	return error; | 
 | } |