| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * Copyright (c) 2008, Christoph Hellwig |
| * All Rights Reserved. |
| */ |
| #include "xfs.h" |
| #include "xfs_shared.h" |
| #include "xfs_format.h" |
| #include "xfs_log_format.h" |
| #include "xfs_trans_resv.h" |
| #include "xfs_mount.h" |
| #include "xfs_inode.h" |
| #include "xfs_da_format.h" |
| #include "xfs_da_btree.h" |
| #include "xfs_attr.h" |
| #include "xfs_trace.h" |
| #include "xfs_error.h" |
| #include "xfs_acl.h" |
| #include "xfs_trans.h" |
| #include "xfs_xattr.h" |
| |
| #include <linux/posix_acl_xattr.h> |
| |
| /* |
| * Locking scheme: |
| * - all ACL updates are protected by inode->i_mutex, which is taken before |
| * calling into this file. |
| */ |
| |
| STATIC struct posix_acl * |
| xfs_acl_from_disk( |
| struct xfs_mount *mp, |
| const struct xfs_acl *aclp, |
| int len, |
| int max_entries) |
| { |
| struct posix_acl_entry *acl_e; |
| struct posix_acl *acl; |
| const struct xfs_acl_entry *ace; |
| unsigned int count, i; |
| |
| if (len < sizeof(*aclp)) { |
| XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, aclp, |
| len); |
| return ERR_PTR(-EFSCORRUPTED); |
| } |
| |
| count = be32_to_cpu(aclp->acl_cnt); |
| if (count > max_entries || XFS_ACL_SIZE(count) != len) { |
| XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, aclp, |
| len); |
| return ERR_PTR(-EFSCORRUPTED); |
| } |
| |
| acl = posix_acl_alloc(count, GFP_KERNEL); |
| if (!acl) |
| return ERR_PTR(-ENOMEM); |
| |
| for (i = 0; i < count; i++) { |
| acl_e = &acl->a_entries[i]; |
| ace = &aclp->acl_entry[i]; |
| |
| /* |
| * The tag is 32 bits on disk and 16 bits in core. |
| * |
| * Because every access to it goes through the core |
| * format first this is not a problem. |
| */ |
| acl_e->e_tag = be32_to_cpu(ace->ae_tag); |
| acl_e->e_perm = be16_to_cpu(ace->ae_perm); |
| |
| switch (acl_e->e_tag) { |
| case ACL_USER: |
| acl_e->e_uid = make_kuid(&init_user_ns, |
| be32_to_cpu(ace->ae_id)); |
| break; |
| case ACL_GROUP: |
| acl_e->e_gid = make_kgid(&init_user_ns, |
| be32_to_cpu(ace->ae_id)); |
| break; |
| case ACL_USER_OBJ: |
| case ACL_GROUP_OBJ: |
| case ACL_MASK: |
| case ACL_OTHER: |
| break; |
| default: |
| goto fail; |
| } |
| } |
| return acl; |
| |
| fail: |
| posix_acl_release(acl); |
| return ERR_PTR(-EINVAL); |
| } |
| |
| STATIC void |
| xfs_acl_to_disk(struct xfs_acl *aclp, const struct posix_acl *acl) |
| { |
| const struct posix_acl_entry *acl_e; |
| struct xfs_acl_entry *ace; |
| int i; |
| |
| aclp->acl_cnt = cpu_to_be32(acl->a_count); |
| for (i = 0; i < acl->a_count; i++) { |
| ace = &aclp->acl_entry[i]; |
| acl_e = &acl->a_entries[i]; |
| |
| ace->ae_tag = cpu_to_be32(acl_e->e_tag); |
| switch (acl_e->e_tag) { |
| case ACL_USER: |
| ace->ae_id = cpu_to_be32( |
| from_kuid(&init_user_ns, acl_e->e_uid)); |
| break; |
| case ACL_GROUP: |
| ace->ae_id = cpu_to_be32( |
| from_kgid(&init_user_ns, acl_e->e_gid)); |
| break; |
| default: |
| ace->ae_id = cpu_to_be32(ACL_UNDEFINED_ID); |
| break; |
| } |
| |
| ace->ae_perm = cpu_to_be16(acl_e->e_perm); |
| } |
| } |
| |
| struct posix_acl * |
| xfs_get_acl(struct inode *inode, int type, bool rcu) |
| { |
| struct xfs_inode *ip = XFS_I(inode); |
| struct xfs_mount *mp = ip->i_mount; |
| struct posix_acl *acl = NULL; |
| struct xfs_da_args args = { |
| .dp = ip, |
| .attr_filter = XFS_ATTR_ROOT, |
| .valuelen = XFS_ACL_MAX_SIZE(mp), |
| }; |
| int error; |
| |
| if (rcu) |
| return ERR_PTR(-ECHILD); |
| |
| trace_xfs_get_acl(ip); |
| |
| switch (type) { |
| case ACL_TYPE_ACCESS: |
| args.name = SGI_ACL_FILE; |
| break; |
| case ACL_TYPE_DEFAULT: |
| args.name = SGI_ACL_DEFAULT; |
| break; |
| default: |
| BUG(); |
| } |
| args.namelen = strlen(args.name); |
| |
| /* |
| * If the attribute doesn't exist make sure we have a negative cache |
| * entry, for any other error assume it is transient. |
| */ |
| error = xfs_attr_get(&args); |
| if (!error) { |
| acl = xfs_acl_from_disk(mp, args.value, args.valuelen, |
| XFS_ACL_MAX_ENTRIES(mp)); |
| } else if (error != -ENOATTR) { |
| acl = ERR_PTR(error); |
| } |
| |
| kmem_free(args.value); |
| return acl; |
| } |
| |
| int |
| __xfs_set_acl(struct inode *inode, struct posix_acl *acl, int type) |
| { |
| struct xfs_inode *ip = XFS_I(inode); |
| struct xfs_da_args args = { |
| .dp = ip, |
| .attr_filter = XFS_ATTR_ROOT, |
| }; |
| int error; |
| |
| switch (type) { |
| case ACL_TYPE_ACCESS: |
| args.name = SGI_ACL_FILE; |
| break; |
| case ACL_TYPE_DEFAULT: |
| if (!S_ISDIR(inode->i_mode)) |
| return acl ? -EACCES : 0; |
| args.name = SGI_ACL_DEFAULT; |
| break; |
| default: |
| return -EINVAL; |
| } |
| args.namelen = strlen(args.name); |
| |
| if (acl) { |
| args.valuelen = XFS_ACL_SIZE(acl->a_count); |
| args.value = kvzalloc(args.valuelen, GFP_KERNEL); |
| if (!args.value) |
| return -ENOMEM; |
| xfs_acl_to_disk(args.value, acl); |
| } |
| |
| error = xfs_attr_change(&args); |
| kmem_free(args.value); |
| |
| /* |
| * If the attribute didn't exist to start with that's fine. |
| */ |
| if (!acl && error == -ENOATTR) |
| error = 0; |
| if (!error) |
| set_cached_acl(inode, type, acl); |
| return error; |
| } |
| |
| static int |
| xfs_acl_set_mode( |
| struct inode *inode, |
| umode_t mode) |
| { |
| struct xfs_inode *ip = XFS_I(inode); |
| struct xfs_mount *mp = ip->i_mount; |
| struct xfs_trans *tp; |
| int error; |
| |
| error = xfs_trans_alloc(mp, &M_RES(mp)->tr_ichange, 0, 0, 0, &tp); |
| if (error) |
| return error; |
| |
| xfs_ilock(ip, XFS_ILOCK_EXCL); |
| xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL); |
| inode->i_mode = mode; |
| inode->i_ctime = current_time(inode); |
| xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE); |
| |
| if (xfs_has_wsync(mp)) |
| xfs_trans_set_sync(tp); |
| return xfs_trans_commit(tp); |
| } |
| |
| int |
| xfs_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry, |
| struct posix_acl *acl, int type) |
| { |
| umode_t mode; |
| bool set_mode = false; |
| int error = 0; |
| struct inode *inode = d_inode(dentry); |
| |
| if (!acl) |
| goto set_acl; |
| |
| error = -E2BIG; |
| if (acl->a_count > XFS_ACL_MAX_ENTRIES(XFS_M(inode->i_sb))) |
| return error; |
| |
| if (type == ACL_TYPE_ACCESS) { |
| error = posix_acl_update_mode(mnt_userns, inode, &mode, &acl); |
| if (error) |
| return error; |
| set_mode = true; |
| } |
| |
| set_acl: |
| /* |
| * We set the mode after successfully updating the ACL xattr because the |
| * xattr update can fail at ENOSPC and we don't want to change the mode |
| * if the ACL update hasn't been applied. |
| */ |
| error = __xfs_set_acl(inode, acl, type); |
| if (!error && set_mode && mode != inode->i_mode) |
| error = xfs_acl_set_mode(inode, mode); |
| return error; |
| } |
| |
| /* |
| * Invalidate any cached ACLs if the user has bypassed the ACL interface. |
| * We don't validate the content whatsoever so it is caller responsibility to |
| * provide data in valid format and ensure i_mode is consistent. |
| */ |
| void |
| xfs_forget_acl( |
| struct inode *inode, |
| const char *name) |
| { |
| if (!strcmp(name, SGI_ACL_FILE)) |
| forget_cached_acl(inode, ACL_TYPE_ACCESS); |
| else if (!strcmp(name, SGI_ACL_DEFAULT)) |
| forget_cached_acl(inode, ACL_TYPE_DEFAULT); |
| } |