| // 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: |
| kfree(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); |
| kfree(value); |
| |
| return acl; |
| } |
| |
| struct posix_acl *f2fs_get_acl(struct inode *inode, int type, bool rcu) |
| { |
| if (rcu) |
| return ERR_PTR(-ECHILD); |
| |
| return __f2fs_get_acl(inode, type, NULL); |
| } |
| |
| static int f2fs_acl_update_mode(struct user_namespace *mnt_userns, |
| struct inode *inode, umode_t *mode_p, |
| struct posix_acl **acl) |
| { |
| umode_t mode = inode->i_mode; |
| int error; |
| |
| if (is_inode_flag_set(inode, FI_ACL_MODE)) |
| mode = F2FS_I(inode)->i_acl_mode; |
| |
| error = posix_acl_equiv_mode(*acl, &mode); |
| if (error < 0) |
| return error; |
| if (error == 0) |
| *acl = NULL; |
| if (!vfsgid_in_group_p(i_gid_into_vfsgid(mnt_userns, inode)) && |
| !capable_wrt_inode_uidgid(mnt_userns, inode, CAP_FSETID)) |
| mode &= ~S_ISGID; |
| *mode_p = mode; |
| return 0; |
| } |
| |
| static int __f2fs_set_acl(struct user_namespace *mnt_userns, |
| 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 = f2fs_acl_update_mode(mnt_userns, 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); |
| |
| kfree(value); |
| if (!error) |
| set_cached_acl(inode, type, acl); |
| |
| clear_inode_flag(inode, FI_ACL_MODE); |
| return error; |
| } |
| |
| int f2fs_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry, |
| struct posix_acl *acl, int type) |
| { |
| struct inode *inode = d_inode(dentry); |
| |
| if (unlikely(f2fs_cp_error(F2FS_I_SB(inode)))) |
| return -EIO; |
| |
| return __f2fs_set_acl(mnt_userns, 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; |
| |
| 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(NULL, 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(NULL, inode, ACL_TYPE_ACCESS, acl, |
| ipage); |
| posix_acl_release(acl); |
| } else { |
| inode->i_acl = NULL; |
| } |
| |
| return error; |
| } |