linux-hardened/include/linux/genl_magic_struct.h
Andreas Gruenbacher 5f9359201b drbd: Make drbd's use of netlink attribute flags less confusing
Make it more clear in the flag names which flags are internal to drbd, and
which are not.

The check for mandatory attributes is the only extension visible at the netlink
layer.  Attributes with this flag set would look like unknown attributes to
some kernel versions.  The netlink layer would ignore them and also skip
consistency checks on the attribute type and legth.  To avoid this, we check
for mandatory attributes first, remove the mandatory flag, and then process the
attributes normally.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2012-11-08 16:55:55 +01:00

277 lines
7.4 KiB
C

#ifndef GENL_MAGIC_STRUCT_H
#define GENL_MAGIC_STRUCT_H
#ifndef GENL_MAGIC_FAMILY
# error "you need to define GENL_MAGIC_FAMILY before inclusion"
#endif
#ifndef GENL_MAGIC_VERSION
# error "you need to define GENL_MAGIC_VERSION before inclusion"
#endif
#ifndef GENL_MAGIC_INCLUDE_FILE
# error "you need to define GENL_MAGIC_INCLUDE_FILE before inclusion"
#endif
#include <linux/genetlink.h>
#include <linux/types.h>
#define CONCAT__(a,b) a ## b
#define CONCAT_(a,b) CONCAT__(a,b)
extern int CONCAT_(GENL_MAGIC_FAMILY, _genl_register)(void);
extern void CONCAT_(GENL_MAGIC_FAMILY, _genl_unregister)(void);
/*
* Extension of genl attribute validation policies {{{2
*/
/*
* @DRBD_GENLA_F_MANDATORY: By default, netlink ignores attributes it does not
* know about. This flag can be set in nlattr->nla_type to indicate that this
* attribute must not be ignored.
*
* We check and remove this flag in drbd_nla_check_mandatory() before
* validating the attribute types and lengths via nla_parse_nested().
*/
#define DRBD_GENLA_F_MANDATORY (1 << 14)
/*
* Flags specific to drbd and not visible at the netlink layer, used in
* <struct>_from_attrs and <struct>_to_skb:
*
* @DRBD_F_REQUIRED: Attribute is required; a request without this attribute is
* invalid.
*
* @DRBD_F_SENSITIVE: Attribute includes sensitive information and must not be
* included in unpriviledged get requests or broadcasts.
*
* @DRBD_F_INVARIANT: Attribute is set when an object is initially created, but
* cannot subsequently be changed.
*/
#define DRBD_F_REQUIRED (1 << 0)
#define DRBD_F_SENSITIVE (1 << 1)
#define DRBD_F_INVARIANT (1 << 2)
#define __nla_type(x) ((__u16)((x) & NLA_TYPE_MASK & ~DRBD_GENLA_F_MANDATORY))
/* }}}1
* MAGIC
* multi-include macro expansion magic starts here
*/
/* MAGIC helpers {{{2 */
/* possible field types */
#define __flg_field(attr_nr, attr_flag, name) \
__field(attr_nr, attr_flag, name, NLA_U8, char, \
nla_get_u8, NLA_PUT_U8, false)
#define __u8_field(attr_nr, attr_flag, name) \
__field(attr_nr, attr_flag, name, NLA_U8, unsigned char, \
nla_get_u8, NLA_PUT_U8, false)
#define __u16_field(attr_nr, attr_flag, name) \
__field(attr_nr, attr_flag, name, NLA_U16, __u16, \
nla_get_u16, NLA_PUT_U16, false)
#define __u32_field(attr_nr, attr_flag, name) \
__field(attr_nr, attr_flag, name, NLA_U32, __u32, \
nla_get_u32, NLA_PUT_U32, false)
#define __s32_field(attr_nr, attr_flag, name) \
__field(attr_nr, attr_flag, name, NLA_U32, __s32, \
nla_get_u32, NLA_PUT_U32, true)
#define __u64_field(attr_nr, attr_flag, name) \
__field(attr_nr, attr_flag, name, NLA_U64, __u64, \
nla_get_u64, NLA_PUT_U64, false)
#define __str_field(attr_nr, attr_flag, name, maxlen) \
__array(attr_nr, attr_flag, name, NLA_NUL_STRING, char, maxlen, \
nla_strlcpy, NLA_PUT, false)
#define __bin_field(attr_nr, attr_flag, name, maxlen) \
__array(attr_nr, attr_flag, name, NLA_BINARY, char, maxlen, \
nla_memcpy, NLA_PUT, false)
/* fields with default values */
#define __flg_field_def(attr_nr, attr_flag, name, default) \
__flg_field(attr_nr, attr_flag, name)
#define __u32_field_def(attr_nr, attr_flag, name, default) \
__u32_field(attr_nr, attr_flag, name)
#define __s32_field_def(attr_nr, attr_flag, name, default) \
__s32_field(attr_nr, attr_flag, name)
#define __str_field_def(attr_nr, attr_flag, name, maxlen) \
__str_field(attr_nr, attr_flag, name, maxlen)
#define GENL_op_init(args...) args
#define GENL_doit(handler) \
.doit = handler, \
.flags = GENL_ADMIN_PERM,
#define GENL_dumpit(handler) \
.dumpit = handler, \
.flags = GENL_ADMIN_PERM,
/* }}}1
* Magic: define the enum symbols for genl_ops
* Magic: define the enum symbols for top level attributes
* Magic: define the enum symbols for nested attributes
* {{{2
*/
#undef GENL_struct
#define GENL_struct(tag_name, tag_number, s_name, s_fields)
#undef GENL_mc_group
#define GENL_mc_group(group)
#undef GENL_notification
#define GENL_notification(op_name, op_num, mcast_group, tla_list) \
op_name = op_num,
#undef GENL_op
#define GENL_op(op_name, op_num, handler, tla_list) \
op_name = op_num,
enum {
#include GENL_MAGIC_INCLUDE_FILE
};
#undef GENL_notification
#define GENL_notification(op_name, op_num, mcast_group, tla_list)
#undef GENL_op
#define GENL_op(op_name, op_num, handler, attr_list)
#undef GENL_struct
#define GENL_struct(tag_name, tag_number, s_name, s_fields) \
tag_name = tag_number,
enum {
#include GENL_MAGIC_INCLUDE_FILE
};
#undef GENL_struct
#define GENL_struct(tag_name, tag_number, s_name, s_fields) \
enum { \
s_fields \
};
#undef __field
#define __field(attr_nr, attr_flag, name, nla_type, type, \
__get, __put, __is_signed) \
T_ ## name = (__u16)(attr_nr | ((attr_flag) & DRBD_GENLA_F_MANDATORY)),
#undef __array
#define __array(attr_nr, attr_flag, name, nla_type, type, \
maxlen, __get, __put, __is_signed) \
T_ ## name = (__u16)(attr_nr | ((attr_flag) & DRBD_GENLA_F_MANDATORY)),
#include GENL_MAGIC_INCLUDE_FILE
/* }}}1
* Magic: compile time assert unique numbers for operations
* Magic: -"- unique numbers for top level attributes
* Magic: -"- unique numbers for nested attributes
* {{{2
*/
#undef GENL_struct
#define GENL_struct(tag_name, tag_number, s_name, s_fields)
#undef GENL_op
#define GENL_op(op_name, op_num, handler, attr_list) \
case op_name:
#undef GENL_notification
#define GENL_notification(op_name, op_num, mcast_group, tla_list) \
case op_name:
static inline void ct_assert_unique_operations(void)
{
switch (0) {
#include GENL_MAGIC_INCLUDE_FILE
;
}
}
#undef GENL_op
#define GENL_op(op_name, op_num, handler, attr_list)
#undef GENL_notification
#define GENL_notification(op_name, op_num, mcast_group, tla_list)
#undef GENL_struct
#define GENL_struct(tag_name, tag_number, s_name, s_fields) \
case tag_number:
static inline void ct_assert_unique_top_level_attributes(void)
{
switch (0) {
#include GENL_MAGIC_INCLUDE_FILE
;
}
}
#undef GENL_struct
#define GENL_struct(tag_name, tag_number, s_name, s_fields) \
static inline void ct_assert_unique_ ## s_name ## _attributes(void) \
{ \
switch (0) { \
s_fields \
; \
} \
}
#undef __field
#define __field(attr_nr, attr_flag, name, nla_type, type, __get, __put, \
__is_signed) \
case attr_nr:
#undef __array
#define __array(attr_nr, attr_flag, name, nla_type, type, maxlen, \
__get, __put, __is_signed) \
case attr_nr:
#include GENL_MAGIC_INCLUDE_FILE
/* }}}1
* Magic: declare structs
* struct <name> {
* fields
* };
* {{{2
*/
#undef GENL_struct
#define GENL_struct(tag_name, tag_number, s_name, s_fields) \
struct s_name { s_fields };
#undef __field
#define __field(attr_nr, attr_flag, name, nla_type, type, __get, __put, \
__is_signed) \
type name;
#undef __array
#define __array(attr_nr, attr_flag, name, nla_type, type, maxlen, \
__get, __put, __is_signed) \
type name[maxlen]; \
__u32 name ## _len;
#include GENL_MAGIC_INCLUDE_FILE
#undef GENL_struct
#define GENL_struct(tag_name, tag_number, s_name, s_fields) \
enum { \
s_fields \
};
#undef __field
#define __field(attr_nr, attr_flag, name, nla_type, type, __get, __put, \
is_signed) \
F_ ## name ## _IS_SIGNED = is_signed,
#undef __array
#define __array(attr_nr, attr_flag, name, nla_type, type, maxlen, \
__get, __put, is_signed) \
F_ ## name ## _IS_SIGNED = is_signed,
#include GENL_MAGIC_INCLUDE_FILE
/* }}}1 */
#endif /* GENL_MAGIC_STRUCT_H */
/* vim: set foldmethod=marker nofoldenable : */