[PATCH v23 19/22] richacl: Add richacl xattr handler

Andreas Gruenbacher
2016-06-30T13:53:04Z

Add richacl xattr handler implementing the xattr operations based on the
get_richacl and set_richacl inode operations.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
---
fs/richacl.c | 22 ++++++++++++++++
fs/richacl_xattr.c | 61 +++++++++++++++++++++++++++++++++++++++++++
include/linux/richacl.h | 1 +
include/linux/richacl_xattr.h | 2 ++
4 files changed, 86 insertions(+)

diff --git a/fs/richacl.c b/fs/richacl.c
index 40e4af9..b7d7104 100644
--- a/fs/richacl.c
+++ b/fs/richacl.c
@@ -549,6 +549,28 @@ out:
EXPORT_SYMBOL_GPL(richacl_permission);

/**
+ * set_richacl - set the richacl of an inode
+ * @inode: inode whose richacl to set
+ * @acl: access control list
+ */
+int
+set_richacl(struct inode *inode, struct richacl *acl)
+{
+ if (!IS_RICHACL(inode))
+ return -EOPNOTSUPP;
+ if (!inode->i_op->set_richacl)
+ return -EOPNOTSUPP;
+
+ if (!uid_eq(current_fsuid(), inode->i_uid) &&
+ inode_permission(inode, MAY_CHMOD) &&
+ !capable(CAP_FOWNER))
+ return -EPERM;
+
+ return inode->i_op->set_richacl(inode, acl);
+}
+EXPORT_SYMBOL(set_richacl);
+
+/**
* __richacl_chmod - update the file masks to reflect the new mode
* @acl: access control list
* @mode: new file permission bits including the file type
diff --git a/fs/richacl_xattr.c b/fs/richacl_xattr.c
index dc1ad36..5eb4aba 100644
--- a/fs/richacl_xattr.c
+++ b/fs/richacl_xattr.c
@@ -18,7 +18,9 @@
#include <linux/fs.h>
#include <linux/slab.h>
#include <linux/module.h>
+#include <linux/xattr.h>
#include <linux/richacl_xattr.h>
+#include <uapi/linux/xattr.h>

/**
* richacl_from_xattr - convert a richacl xattr into the in-memory representation
@@ -159,3 +161,62 @@ richacl_to_xattr(struct user_namespace *user_ns,
return real_size;
}
EXPORT_SYMBOL_GPL(richacl_to_xattr);
+
+static bool
+richacl_xattr_list(struct dentry *dentry)
+{
+ return IS_RICHACL(d_backing_inode(dentry));
+}
+
+static int
+richacl_xattr_get(const struct xattr_handler *handler,
+ struct dentry *unused, struct inode *inode,
+ const char *name, void *buffer, size_t buffer_size)
+{
+ struct richacl *acl;
+ int error;
+
+ if (*name)
+ return -EINVAL;
+ if (!IS_RICHACL(inode))
+ return -EOPNOTSUPP;
+ if (S_ISLNK(inode->i_mode))
+ return -EOPNOTSUPP;
+ acl = get_richacl(inode);
+ if (IS_ERR(acl))
+ return PTR_ERR(acl);
+ if (acl == NULL)
+ return -ENODATA;
+ error = richacl_to_xattr(current_user_ns(), acl, buffer, buffer_size);
+ richacl_put(acl);
+ return error;
+}
+
+static int
+richacl_xattr_set(const struct xattr_handler *handler,
+ struct dentry *unused, struct inode *inode,
+ const char *name, const void *value, size_t size,
+ int flags)
+{
+ struct richacl *acl = NULL;
+ int ret;
+
+ if (value) {
+ acl = richacl_from_xattr(current_user_ns(), value, size,
+ -EINVAL);
+ if (IS_ERR(acl))
+ return PTR_ERR(acl);
+ }
+
+ ret = set_richacl(inode, acl);
+ richacl_put(acl);
+ return ret;
+}
+
+struct xattr_handler richacl_xattr_handler = {
+ .name = XATTR_NAME_RICHACL,
+ .list = richacl_xattr_list,
+ .get = richacl_xattr_get,
+ .set = richacl_xattr_set,
+};
+EXPORT_SYMBOL(richacl_xattr_handler);
diff --git a/include/linux/richacl.h b/include/linux/richacl.h
index a442372..e7db066 100644
--- a/include/linux/richacl.h
+++ b/include/linux/richacl.h
@@ -206,5 +206,6 @@ extern int richacl_chmod(struct inode *, umode_t);
extern int richacl_equiv_mode(const struct richacl *, umode_t *);
extern struct richacl *richacl_inherit(const struct richacl *, int);
extern struct richacl *richacl_create(umode_t *, struct inode *);
+extern int set_richacl(struct inode *, struct richacl *);

#endif /* __RICHACL_H */
diff --git a/include/linux/richacl_xattr.h b/include/linux/richacl_xattr.h
index 0efa14b..6c6adb1 100644
--- a/include/linux/richacl_xattr.h
+++ b/include/linux/richacl_xattr.h
@@ -26,4 +26,6 @@ extern size_t richacl_xattr_size(const struct richacl *);
extern int richacl_to_xattr(struct user_namespace *, const struct richacl *,
void *, size_t);

+extern struct xattr_handler richacl_xattr_handler;
+
#endif /* __RICHACL_XATTR_H */
--
2.5.5