From d9a738597faf7cd2edeec82ce8fd81969fed8390 Mon Sep 17 00:00:00 2001 From: Jim Garlick Date: Wed, 29 May 2013 12:09:39 -0700 Subject: fs/9p: xattr: add trusted and security namespaces Allow requests for security.* and trusted.* xattr name spaces to pass through to server. The new files are 99% cut and paste from fs/9p/xattr_user.c with the namespaces changed. It has the intended effect in superficial testing. I do not know much detail about how these namespaces are used, but passing them through to the server, which can decide whether to handle them or not, seems reasonable. I want to support a use case where an ext4 file system is mounted via 9P, then re-exported via samba to windows clients in a cluster. Windows wants to store xattrs such as security.NTACL. This works when ext4 directly backs samba, but not when 9P is inserted. This use case is documented here: http://code.google.com/p/diod/issues/detail?id=95 Signed-off-by: Jim Garlick Signed-off-by: Eric Van Hensbergen --- fs/9p/xattr_trusted.c | 80 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 80 insertions(+) create mode 100644 fs/9p/xattr_trusted.c (limited to 'fs/9p/xattr_trusted.c') diff --git a/fs/9p/xattr_trusted.c b/fs/9p/xattr_trusted.c new file mode 100644 index 000000000000..e30d33b8a3fb --- /dev/null +++ b/fs/9p/xattr_trusted.c @@ -0,0 +1,80 @@ +/* + * Copyright IBM Corporation, 2010 + * Author Aneesh Kumar K.V + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of version 2.1 of the GNU Lesser General Public License + * as published by the Free Software Foundation. + * + * This program is distributed in the hope that it would be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. + * + */ + + +#include +#include +#include +#include +#include "xattr.h" + +static int v9fs_xattr_trusted_get(struct dentry *dentry, const char *name, + void *buffer, size_t size, int type) +{ + int retval; + char *full_name; + size_t name_len; + size_t prefix_len = XATTR_TRUSTED_PREFIX_LEN; + + if (name == NULL) + return -EINVAL; + + if (strcmp(name, "") == 0) + return -EINVAL; + + name_len = strlen(name); + full_name = kmalloc(prefix_len + name_len + 1 , GFP_KERNEL); + if (!full_name) + return -ENOMEM; + memcpy(full_name, XATTR_TRUSTED_PREFIX, prefix_len); + memcpy(full_name+prefix_len, name, name_len); + full_name[prefix_len + name_len] = '\0'; + + retval = v9fs_xattr_get(dentry, full_name, buffer, size); + kfree(full_name); + return retval; +} + +static int v9fs_xattr_trusted_set(struct dentry *dentry, const char *name, + const void *value, size_t size, int flags, int type) +{ + int retval; + char *full_name; + size_t name_len; + size_t prefix_len = XATTR_TRUSTED_PREFIX_LEN; + + if (name == NULL) + return -EINVAL; + + if (strcmp(name, "") == 0) + return -EINVAL; + + name_len = strlen(name); + full_name = kmalloc(prefix_len + name_len + 1 , GFP_KERNEL); + if (!full_name) + return -ENOMEM; + memcpy(full_name, XATTR_TRUSTED_PREFIX, prefix_len); + memcpy(full_name + prefix_len, name, name_len); + full_name[prefix_len + name_len] = '\0'; + + retval = v9fs_xattr_set(dentry, full_name, value, size, flags); + kfree(full_name); + return retval; +} + +struct xattr_handler v9fs_xattr_trusted_handler = { + .prefix = XATTR_TRUSTED_PREFIX, + .get = v9fs_xattr_trusted_get, + .set = v9fs_xattr_trusted_set, +}; -- cgit v1.2.3