/*
- * linux/fs/posix_acl.c
+ * Copyright (C) 2002,2003 by Andreas Gruenbacher <a.gruenbacher@computer.org>
*
- * Copyright (C) 2002 by Andreas Gruenbacher <a.gruenbacher@computer.org>
- *
- * Fixes from William Schumacher incorporated on 15 March 2001.
- * (Reported by Charles Bertsch, <CBertsch@microtest.com>).
+ * Fixes from William Schumacher incorporated on 15 March 2001.
+ * (Reported by Charles Bertsch, <CBertsch@microtest.com>).
*/
/*
#include <linux/fs.h>
#include <linux/sched.h>
#include <linux/posix_acl.h>
+#include <linux/posix_acl_xattr.h>
#include <linux/export.h>
-
-#include <linux/errno.h>
+#include <linux/user_namespace.h>
EXPORT_SYMBOL(posix_acl_init);
EXPORT_SYMBOL(posix_acl_alloc);
return err;
}
EXPORT_SYMBOL(posix_acl_chmod);
+
+/*
+ * Fix up the uids and gids in posix acl extended attributes in place.
+ */
+static void posix_acl_fix_xattr_userns(
+ struct user_namespace *to, struct user_namespace *from,
+ void *value, size_t size)
+{
+ posix_acl_xattr_header *header = (posix_acl_xattr_header *)value;
+ posix_acl_xattr_entry *entry = (posix_acl_xattr_entry *)(header+1), *end;
+ int count;
+ kuid_t uid;
+ kgid_t gid;
+
+ if (!value)
+ return;
+ if (size < sizeof(posix_acl_xattr_header))
+ return;
+ if (header->a_version != cpu_to_le32(POSIX_ACL_XATTR_VERSION))
+ return;
+
+ count = posix_acl_xattr_count(size);
+ if (count < 0)
+ return;
+ if (count == 0)
+ return;
+
+ for (end = entry + count; entry != end; entry++) {
+ switch(le16_to_cpu(entry->e_tag)) {
+ case ACL_USER:
+ uid = make_kuid(from, le32_to_cpu(entry->e_id));
+ entry->e_id = cpu_to_le32(from_kuid(to, uid));
+ break;
+ case ACL_GROUP:
+ gid = make_kgid(from, le32_to_cpu(entry->e_id));
+ entry->e_id = cpu_to_le32(from_kgid(to, gid));
+ break;
+ default:
+ break;
+ }
+ }
+}
+
+void posix_acl_fix_xattr_from_user(void *value, size_t size)
+{
+ struct user_namespace *user_ns = current_user_ns();
+ if (user_ns == &init_user_ns)
+ return;
+ posix_acl_fix_xattr_userns(&init_user_ns, user_ns, value, size);
+}
+
+void posix_acl_fix_xattr_to_user(void *value, size_t size)
+{
+ struct user_namespace *user_ns = current_user_ns();
+ if (user_ns == &init_user_ns)
+ return;
+ posix_acl_fix_xattr_userns(user_ns, &init_user_ns, value, size);
+}
+
+/*
+ * Convert from extended attribute to in-memory representation.
+ */
+struct posix_acl *
+posix_acl_from_xattr(struct user_namespace *user_ns,
+ const void *value, size_t size)
+{
+ posix_acl_xattr_header *header = (posix_acl_xattr_header *)value;
+ posix_acl_xattr_entry *entry = (posix_acl_xattr_entry *)(header+1), *end;
+ int count;
+ struct posix_acl *acl;
+ struct posix_acl_entry *acl_e;
+
+ if (!value)
+ return NULL;
+ if (size < sizeof(posix_acl_xattr_header))
+ return ERR_PTR(-EINVAL);
+ if (header->a_version != cpu_to_le32(POSIX_ACL_XATTR_VERSION))
+ return ERR_PTR(-EOPNOTSUPP);
+
+ count = posix_acl_xattr_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);
+ acl_e = acl->a_entries;
+
+ for (end = entry + count; entry != end; acl_e++, entry++) {
+ acl_e->e_tag = le16_to_cpu(entry->e_tag);
+ acl_e->e_perm = le16_to_cpu(entry->e_perm);
+
+ switch(acl_e->e_tag) {
+ case ACL_USER_OBJ:
+ case ACL_GROUP_OBJ:
+ case ACL_MASK:
+ case ACL_OTHER:
+ break;
+
+ case ACL_USER:
+ acl_e->e_uid =
+ make_kuid(user_ns,
+ le32_to_cpu(entry->e_id));
+ if (!uid_valid(acl_e->e_uid))
+ goto fail;
+ break;
+ case ACL_GROUP:
+ acl_e->e_gid =
+ make_kgid(user_ns,
+ le32_to_cpu(entry->e_id));
+ if (!gid_valid(acl_e->e_gid))
+ goto fail;
+ break;
+
+ default:
+ goto fail;
+ }
+ }
+ return acl;
+
+fail:
+ posix_acl_release(acl);
+ return ERR_PTR(-EINVAL);
+}
+EXPORT_SYMBOL (posix_acl_from_xattr);
+
+/*
+ * Convert from in-memory to extended attribute representation.
+ */
+int
+posix_acl_to_xattr(struct user_namespace *user_ns, const struct posix_acl *acl,
+ void *buffer, size_t size)
+{
+ posix_acl_xattr_header *ext_acl = (posix_acl_xattr_header *)buffer;
+ posix_acl_xattr_entry *ext_entry = ext_acl->a_entries;
+ int real_size, n;
+
+ real_size = posix_acl_xattr_size(acl->a_count);
+ if (!buffer)
+ return real_size;
+ if (real_size > size)
+ return -ERANGE;
+
+ ext_acl->a_version = cpu_to_le32(POSIX_ACL_XATTR_VERSION);
+
+ for (n=0; n < acl->a_count; n++, ext_entry++) {
+ const struct posix_acl_entry *acl_e = &acl->a_entries[n];
+ ext_entry->e_tag = cpu_to_le16(acl_e->e_tag);
+ ext_entry->e_perm = cpu_to_le16(acl_e->e_perm);
+ switch(acl_e->e_tag) {
+ case ACL_USER:
+ ext_entry->e_id =
+ cpu_to_le32(from_kuid(user_ns, acl_e->e_uid));
+ break;
+ case ACL_GROUP:
+ ext_entry->e_id =
+ cpu_to_le32(from_kgid(user_ns, acl_e->e_gid));
+ break;
+ default:
+ ext_entry->e_id = cpu_to_le32(ACL_UNDEFINED_ID);
+ break;
+ }
+ }
+ return real_size;
+}
+EXPORT_SYMBOL (posix_acl_to_xattr);
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