#ifndef GENL_MAGIC_FUNC_H
#define GENL_MAGIC_FUNC_H
#include <linux/genl_magic_struct.h>
/*
* Extension of genl attribute validation policies {{{1
* {{{2
*/
/**
* nla_is_required - return true if this attribute is required
* @nla: netlink attribute
*/
static inline int nla_is_required(const struct nlattr *nla)
{
return nla->nla_type & GENLA_F_REQUIRED;
}
/**
* nla_is_mandatory - return true if understanding this attribute is mandatory
* @nla: netlink attribute
* Note: REQUIRED attributes are implicitly MANDATORY as well
*/
static inline int nla_is_mandatory(const struct nlattr *nla)
{
return nla->nla_type & (GENLA_F_MANDATORY | GENLA_F_REQUIRED);
}
/* Functionality to be integrated into nla_parse(), and validate_nla(),
* respectively.
*
* Enforcing the "mandatory" bit is done here,
* by rejecting unknown mandatory attributes.
*
* Part of enforcing the "required" flag would mean to embed it into
* nla_policy.type, and extending validate_nla(), which currently does
* BUG_ON(pt->type > NLA_TYPE_MAX); we have to work on existing kernels,
* so we cannot do that. Thats why enforcing "required" is done in the
* generated assignment functions below. */
static int nla_check_unknown(int maxtype, struct nlattr *head, int len)
{
struct nlattr *nla;
int rem;
nla_for_each_attr(nla, head, len, rem) {
__u16 type = nla_type(nla);
if (type > maxtype && nla_is_mandatory(nla))
return -EOPNOTSUPP;
}
return 0;
}
/*
* Magic: declare tla policy {{{1
* Magic: declare nested policies
* {{{2
*/
#undef GENL_mc_group
#define GENL_mc_group(group)
#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, tla_list)
#undef GENL_struct
#define GENL_struct(tag_name, tag_number, s_name, s_fields) \
[tag_name] = { .type = NLA_NESTED },
static struct nla_policy CONCAT_(GENL_MAGIC_FAMILY, _tla_nl_policy)[] = {
#include GENL_MAGIC_INCLUDE_FILE
};
#undef GENL_struct
#define GENL_struct(tag_name, tag_number, s_name, s_fields) \
static struct nla_policy s_name ## _nl_policy[] __read_mostly = \
{ s_fields };
#undef __field
#define __field(attr_nr, attr_flag, name, nla_type, _type, __get, __put) \
[__nla_type(attr_nr)] = { .type = nla_type },
#undef __array
#define __array(attr_nr, attr_flag, name, nla_type, _type, maxlen, \
__get, __put) \
[__nla_type(attr_nr)] = { .type = nla_type, \
.len = maxlen - (nla_type == NLA_NUL_STRING) },
#include GENL_MAGIC_INCLUDE_FILE
#ifndef __KERNEL__
#ifndef pr_info
#define pr_info(args...) fprintf(stderr, args);
#endif
#endif
#ifdef GENL_MAGIC_DEBUG
static void dprint_field(const char *dir, int nla_type,
const char *name, void *valp)
{
__u64 val = valp ? *(__u32 *)valp : 1;
switch (nla_type) {
case NLA_U8: val = (__u8)val;
case NLA_U16: val = (__u16)val;
case NLA_U32: val = (__u32)val;
pr_info("%s attr %s: %d 0x%08x\n", dir,
name, (int)val, (unsigned)val);
break;
case NLA_U64:
val = *(__u64*)valp;
pr_info("%s attr %s: %lld 0x%08llx\n", dir,
name, (long long)val, (unsigned long long)val);
break;
case NLA_FLAG:
if (val)
pr_info("%s attr %s: set\n", dir, name);
break;
}
}
static void dprint_array(const char *dir, int nla_type,
const char *name, const char *val, unsigned len)
{
switch (nla_type) {
case NLA_NUL_STRING:
if (len && val[len-1] == '\0')
len--;
pr_info("%s attr %s: [len:%u] '%s'\n", dir, name, len, val);
break;
default:
/* we can always show 4 byte,
* thats what nlattr are aligned to. */
pr_info("%s attr %s: [len:%u] %02x%02x%02x%02x ...\n",
dir, name, len, val[0], val[1], val[2], val[3]);
}
}
#define DPRINT_TLA(a, op, b) pr_info("%s %s %s\n", a, op, b);
/* Name is a member field name of the struct s.
* If s is NULL (only parsing, no copy requested in *_from_attrs()),
* nla is supposed to point to the attribute containing the information
* corresponding to that struct member. */
#define DPRINT_FIELD(dir, nla_type, name, s, nla) \
do { \
if (s) \
dprint_field(dir, nla_type, #name, &s->name); \
else if (nla) \
dprint_field(dir, nla_type, #name, \
(nla_type == NLA_FLAG) ? NULL \
: nla_data(nla)); \
} while (0)
#define DPRINT_ARRAY(dir, nla_type, name, s, nla) \
do { \
if (s) \
dprint_array(dir, nla_type, #name, \
s->name, s->name ## _len); \
else if (nla) \
dprint_array(dir, nla_type, #name, \
nla_data(nla), nla_len(nla)); \
} while (0)
#else
#define DPRINT_TLA(a, op, b) do {} while (0)
#define DPRINT_FIELD(dir, nla_type, name, s, nla) do {} while (0)
#define DPRINT_ARRAY(dir, nla_type, name, s, nla) do {} while (0)
#endif
/*
* Magic: provide conversion functions {{{1
* populate struct from attribute table:
* {{{2
*/
/* processing of generic netlink messages is serialized.
* use one static buffer for parsing of nested attributes */
static struct nlattr *nested_attr_tb[128];
#ifndef BUILD_BUG_ON
/* Force a compilation error if condition is true */
#define BUILD_BUG_ON(condition) ((void)BUILD_BUG_ON_ZERO(condition))
/* Force a compilation error if condition is true, but also produce a
result (of value 0 and type size_t), so the expression can be used
e.g. in a structure initializer (or where-ever else comma expressions
aren't permitted). */
#define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:-!!(e); }))
#define BUILD_BUG_ON_NULL(e) ((void *)sizeof(struct { int:-!!(e); }))
#endif
#undef GENL_struct
#define GENL_struct(tag_name, tag_number, s_name, s_fields) \
/* *_from_attrs functions are static, but potentially unused */ \
static int __ ## s_name ## _from_attrs(struct s_name *s, \
struct genl_info *info, bool exclude_invariants) \
{ \
const int maxtype = ARRAY_SIZE(s_name ## _nl_policy)-1; \
struct nlattr *tla = info->attrs[tag_number]; \
struct nlattr **ntb = nested_attr_tb; \
struct nlattr *nla; \
int err; \
BUILD_BUG_ON(ARRAY_SIZE(s_name ## _nl_policy) > ARRAY_SIZE(nested_attr_tb)); \
if (!tla) \
return -ENOMSG; \
DPRINT_TLA(#s_name, "<=-", #tag_name); \
err = nla_parse_nested(ntb, maxtype, tla, s_name ## _nl_policy); \
if (err) \
return err; \
err = nla_check_unknown(maxtype, nla_data(tla), nla_len(tla)); \
if (err) \
return err; \
\
s_fields \
return 0; \
} __attribute__((unused)) \
static int s_name ## _from_attrs(struct s_name *s, \
struct genl_info *info) \
{ \
return __ ## s_name ## _from_attrs(s, info, false); \
} __attribute__((unused)) \
static int s_name ## _from_attrs_for_change(struct s_name *s, \
struct genl_info *info) \
{ \
return __ ## s_name ## _from_attrs(s, info, true); \
} __attribute__((unused)) \
#define __assign(attr_nr, attr_flag, name, nla_type, type, assignment...) \
nla = ntb[__nla_type(attr_nr)]; \
if (nla) { \
if (exclude_invariants && ((attr_flag) & GENLA_F_INVARIANT)) { \
pr_info("<< must not change invariant attr: %s\n", #name); \
return -EEXIST; \
} \
assignment; \
} else if (exclude_invariants && ((attr_flag) & GENLA_F_INVARIANT)) { \
/* attribute missing from payload, */ \
/* which was expected */ \
} else if ((attr_flag) & GENLA_F_REQUIRED) { \
pr_info("<< missing attr: %s\n", #name); \
return -ENOMSG; \
}
#undef __field
#define __field(attr_nr, attr_flag, name, nla_type, type, __get, __put) \
__assign(attr_nr, attr_flag, name, nla_type, type, \
if (s) \
s->name = __get(nla); \
DPRINT_FIELD("<<", nla_type, name, s, nla))
/* validate_nla() already checked nla_len <= maxlen appropriately. */
#undef __array
#define __array(attr_nr, attr_flag, name, nla_type, type, maxlen, __get, __put) \
__assign(attr_nr, attr_flag, name, nla_type, type, \
if (s) \
s->name ## _len = \
__get(s->name, nla, maxlen); \
DPRINT_ARRAY("<<", nla_type, name, s, nla))
#include GENL_MAGIC_INCLUDE_FILE
#undef GENL_struct
#define GENL_struct(tag_name, tag_number, s_name, s_fields)
/*
* Magic: define op number to op name mapping {{{1
* {{{2
*/
const char *CONCAT_(GENL_MAGIC_FAMILY, _genl_cmd_to_str)(__u8 cmd)
{
switch (cmd) {
#undef GENL_op
#define GENL_op(op_name, op_num, handler, tla_list) \
case op_num: return #op_name;
#include GENL_MAGIC_INCLUDE_FILE
default:
return "unknown";
}
}
#ifdef __KERNEL__
#include <linux/stringify.h>
/*
* Magic: define genl_ops {{{1
* {{{2
*/
#undef GENL_op
#define GENL_op(op_name, op_num, handler, tla_list) \
{ \
handler \
.cmd = op_name, \
.policy = CONCAT_(GENL_MAGIC_FAMILY, _tla_nl_policy), \
},
#define ZZZ_genl_ops CONCAT_(GENL_MAGIC_FAMILY, _genl_ops)
static struct genl_ops ZZZ_genl_ops[] __read_mostly = {
#include GENL_MAGIC_INCLUDE_FILE
};
#undef GENL_op
#define GENL_op(op_name, op_num, handler, tla_list)
/*
* Define the genl_family, multicast groups, {{{1
* and provide register/unregister functions.
* {{{2
*/
#define ZZZ_genl_family CONCAT_(GENL_MAGIC_FAMILY, _genl_family)
static struct genl_family ZZZ_genl_family __read_mostly = {
.id = GENL_ID_GENERATE,
.name = __stringify(GENL_MAGIC_FAMILY),
.version = GENL_MAGIC_VERSION,
#ifdef GENL_MAGIC_FAMILY_HDRSZ
.hdrsize = NLA_ALIGN(GENL_MAGIC_FAMILY_HDRSZ),
#endif
.maxattr = ARRAY_SIZE(drbd_tla_nl_policy)-1,
};
/*
* Magic: define multicast groups
* Magic: define multicast group registration helper
*/
#undef GENL_mc_group
#define GENL_mc_group(group) \
static struct genl_multicast_group \
CONCAT_(GENL_MAGIC_FAMILY, _mcg_ ## group) __read_mostly = { \
.name = #group, \
}; \
static int CONCAT_(GENL_MAGIC_FAMILY, _genl_multicast_ ## group)( \
struct sk_buff *skb, gfp_t flags) \
{ \
unsigned int group_id = \
CONCAT_(GENL_MAGIC_FAMILY, _mcg_ ## group).id; \
if (!group_id) \
return -EINVAL; \
return genlmsg_multicast(skb, 0, group_id, flags); \
}
#include GENL_MAGIC_INCLUDE_FILE
int CONCAT_(GENL_MAGIC_FAMILY, _genl_register)(void)
{
int err = genl_register_family_with_ops(&ZZZ_genl_family,
ZZZ_genl_ops, ARRAY_SIZE(ZZZ_genl_ops));
if (err)
return err;
#undef GENL_mc_group
#define GENL_mc_group(group) \
err = genl_register_mc_group(&ZZZ_genl_family, \
&CONCAT_(GENL_MAGIC_FAMILY, _mcg_ ## group)); \
if (err) \
goto fail; \
else \
pr_info("%s: mcg %s: %u\n", #group, \
__stringify(GENL_MAGIC_FAMILY), \
CONCAT_(GENL_MAGIC_FAMILY, _mcg_ ## group).id);
#include GENL_MAGIC_INCLUDE_FILE
#undef GENL_mc_group
#define GENL_mc_group(group)
return 0;
fail:
genl_unregister_family(&ZZZ_genl_family);
return err;
}
void CONCAT_(GENL_MAGIC_FAMILY, _genl_unregister)(void)
{
genl_unregister_family(&ZZZ_genl_family);
}
/*
* Magic: provide conversion functions {{{1
* populate skb from struct.
* {{{2
*/
#undef GENL_op
#define GENL_op(op_name, op_num, handler, tla_list)
#undef GENL_struct
#define GENL_struct(tag_name, tag_number, s_name, s_fields) \
static int s_name ## _to_skb(struct sk_buff *skb, struct s_name *s, \
const bool exclude_sensitive) \
{ \
struct nlattr *tla = nla_nest_start(skb, tag_number); \
if (!tla) \
goto nla_put_failure; \
DPRINT_TLA(#s_name, "-=>", #tag_name); \
s_fields \
nla_nest_end(skb, tla); \
return 0; \
\
nla_put_failure: \
if (tla) \
nla_nest_cancel(skb, tla); \
return -EMSGSIZE; \
} \
static inline int s_name ## _to_priv_skb(struct sk_buff *skb, \
struct s_name *s) \
{ \
return s_name ## _to_skb(skb, s, 0); \
} \
static inline int s_name ## _to_unpriv_skb(struct sk_buff *skb, \
struct s_name *s) \
{ \
return s_name ## _to_skb(skb, s, 1); \
}
#undef __field
#define __field(attr_nr, attr_flag, name, nla_type, type, __get, __put) \
if (!exclude_sensitive || !((attr_flag) & GENLA_F_SENSITIVE)) { \
DPRINT_FIELD(">>", nla_type, name, s, NULL); \
__put(skb, attr_nr, s->name); \
}
#undef __array
#define __array(attr_nr, attr_flag, name, nla_type, type, maxlen, __get, __put) \
if (!exclude_sensitive || !((attr_flag) & GENLA_F_SENSITIVE)) { \
DPRINT_ARRAY(">>",nla_type, name, s, NULL); \
__put(skb, attr_nr, min_t(int, maxlen, \
s->name ## _len + (nla_type == NLA_NUL_STRING)),\
s->name); \
}
#include GENL_MAGIC_INCLUDE_FILE
#endif /* __KERNEL__ */
/* }}}1 */
#endif /* GENL_MAGIC_FUNC_H */
/* vim: set foldmethod=marker foldlevel=1 nofoldenable : */
