From d9a738597faf7cd2edeec82ce8fd81969fed8390 Mon Sep 17 00:00:00 2001 From: Jim Garlick Date: Wed, 29 May 2013 12:09:39 -0700 Subject: [PATCH] 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/Kconfig | 13 +++++++ fs/9p/Makefile | 4 ++- fs/9p/xattr.c | 4 +++ fs/9p/xattr.h | 2 ++ fs/9p/xattr_security.c | 80 ++++++++++++++++++++++++++++++++++++++++++ fs/9p/xattr_trusted.c | 80 ++++++++++++++++++++++++++++++++++++++++++ 6 files changed, 182 insertions(+), 1 deletion(-) create mode 100644 fs/9p/xattr_security.c create mode 100644 fs/9p/xattr_trusted.c diff --git a/fs/9p/Kconfig b/fs/9p/Kconfig index 55abfd62654a..6489e1fc1afd 100644 --- a/fs/9p/Kconfig +++ b/fs/9p/Kconfig @@ -31,3 +31,16 @@ config 9P_FS_POSIX_ACL If you don't know what Access Control Lists are, say N endif + + +config 9P_FS_SECURITY + bool "9P Security Labels" + depends on 9P_FS + help + Security labels support alternative access control models + implemented by security modules like SELinux. This option + enables an extended attribute handler for file security + labels in the 9P filesystem. + + If you are not using a security module that requires using + extended attributes for file security labels, say N. diff --git a/fs/9p/Makefile b/fs/9p/Makefile index ab8c12780634..ff7be98f84f2 100644 --- a/fs/9p/Makefile +++ b/fs/9p/Makefile @@ -11,7 +11,9 @@ obj-$(CONFIG_9P_FS) := 9p.o v9fs.o \ fid.o \ xattr.o \ - xattr_user.o + xattr_user.o \ + xattr_trusted.o 9p-$(CONFIG_9P_FSCACHE) += cache.o 9p-$(CONFIG_9P_FS_POSIX_ACL) += acl.o +9p-$(CONFIG_9P_FS_SECURITY) += xattr_security.o diff --git a/fs/9p/xattr.c b/fs/9p/xattr.c index c45e016b190f..3c28cdfb8c47 100644 --- a/fs/9p/xattr.c +++ b/fs/9p/xattr.c @@ -167,9 +167,13 @@ ssize_t v9fs_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size) const struct xattr_handler *v9fs_xattr_handlers[] = { &v9fs_xattr_user_handler, + &v9fs_xattr_trusted_handler, #ifdef CONFIG_9P_FS_POSIX_ACL &v9fs_xattr_acl_access_handler, &v9fs_xattr_acl_default_handler, +#endif +#ifdef CONFIG_9P_FS_SECURITY + &v9fs_xattr_security_handler, #endif NULL }; diff --git a/fs/9p/xattr.h b/fs/9p/xattr.h index eec348a3df71..d3e2ea3840be 100644 --- a/fs/9p/xattr.h +++ b/fs/9p/xattr.h @@ -20,6 +20,8 @@ extern const struct xattr_handler *v9fs_xattr_handlers[]; extern struct xattr_handler v9fs_xattr_user_handler; +extern struct xattr_handler v9fs_xattr_trusted_handler; +extern struct xattr_handler v9fs_xattr_security_handler; extern const struct xattr_handler v9fs_xattr_acl_access_handler; extern const struct xattr_handler v9fs_xattr_acl_default_handler; diff --git a/fs/9p/xattr_security.c b/fs/9p/xattr_security.c new file mode 100644 index 000000000000..cb247a142a6e --- /dev/null +++ b/fs/9p/xattr_security.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_security_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_SECURITY_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_SECURITY_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_security_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_SECURITY_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_SECURITY_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_security_handler = { + .prefix = XATTR_SECURITY_PREFIX, + .get = v9fs_xattr_security_get, + .set = v9fs_xattr_security_set, +}; 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, +}; -- 2.20.1