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kernel/include/linux/genl_magic_func.h
Andy Shevchenko 2e106e5643 genetlink: replace custom CONCATENATE() implementation 
Replace custom implementation of the macros from args.h.

Link: https://lkml.kernel.org/r/20230718211147.18647-5-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Brendan Higgins <brendan.higgins@linux.dev>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Daniel Latypov <dlatypov@google.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Gow <davidgow@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lorenzo Pieralisi <lpieralisi@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-18 10:18:57 -07:00

408 lines
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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef GENL_MAGIC_FUNC_H
#define GENL_MAGIC_FUNC_H
#include <linux/args.h>
#include <linux/build_bug.h>
#include <linux/genl_magic_struct.h>
/*
* 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 CONCATENATE(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, __is_signed) \
[attr_nr] = { .type = nla_type },
#undef __array
#define __array(attr_nr, attr_flag, name, nla_type, _type, maxlen, \
__get, __put, __is_signed) \
[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];
#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 = drbd_nla_parse_nested(ntb, maxtype, tla, s_name ## _nl_policy); \
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[attr_nr]; \
if (nla) { \
if (exclude_invariants && !!((attr_flag) & DRBD_F_INVARIANT)) { \
pr_info("<< must not change invariant attr: %s\n", #name); \
return -EEXIST; \
} \
assignment; \
} else if (exclude_invariants && !!((attr_flag) & DRBD_F_INVARIANT)) { \
/* attribute missing from payload, */ \
/* which was expected */ \
} else if ((attr_flag) & DRBD_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, \
__is_signed) \
__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, __is_signed) \
__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
*/
static const char *CONCATENATE(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, \
},
#define ZZZ_genl_ops CONCATENATE(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 CONCATENATE(GENL_MAGIC_FAMILY, _genl_family)
static struct genl_family ZZZ_genl_family;
/*
* Magic: define multicast groups
* Magic: define multicast group registration helper
*/
#define ZZZ_genl_mcgrps CONCATENATE(GENL_MAGIC_FAMILY, _genl_mcgrps)
static const struct genl_multicast_group ZZZ_genl_mcgrps[] = {
#undef GENL_mc_group
#define GENL_mc_group(group) { .name = #group, },
#include GENL_MAGIC_INCLUDE_FILE
};
enum CONCATENATE(GENL_MAGIC_FAMILY, group_ids) {
#undef GENL_mc_group
#define GENL_mc_group(group) CONCATENATE(GENL_MAGIC_FAMILY, _group_ ## group),
#include GENL_MAGIC_INCLUDE_FILE
};
#undef GENL_mc_group
#define GENL_mc_group(group) \
static int CONCATENATE(GENL_MAGIC_FAMILY, _genl_multicast_ ## group)( \
struct sk_buff *skb, gfp_t flags) \
{ \
unsigned int group_id = \
CONCATENATE(GENL_MAGIC_FAMILY, _group_ ## group); \
return genlmsg_multicast(&ZZZ_genl_family, skb, 0, \
group_id, flags); \
}
#include GENL_MAGIC_INCLUDE_FILE
#undef GENL_mc_group
#define GENL_mc_group(group)
static struct genl_family ZZZ_genl_family __ro_after_init = {
.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(CONCATENATE(GENL_MAGIC_FAMILY, _tla_nl_policy))-1,
.policy = CONCATENATE(GENL_MAGIC_FAMILY, _tla_nl_policy),
.ops = ZZZ_genl_ops,
.n_ops = ARRAY_SIZE(ZZZ_genl_ops),
.mcgrps = ZZZ_genl_mcgrps,
.resv_start_op = 42, /* drbd is currently the only user */
.n_mcgrps = ARRAY_SIZE(ZZZ_genl_mcgrps),
.module = THIS_MODULE,
};
int CONCATENATE(GENL_MAGIC_FAMILY, _genl_register)(void)
{
return genl_register_family(&ZZZ_genl_family);
}
void CONCATENATE(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, \
__is_signed) \
if (!exclude_sensitive || !((attr_flag) & DRBD_F_SENSITIVE)) { \
DPRINT_FIELD(">>", nla_type, name, s, NULL); \
if (__put(skb, attr_nr, s->name)) \
goto nla_put_failure; \
}
#undef __array
#define __array(attr_nr, attr_flag, name, nla_type, type, maxlen, \
__get, __put, __is_signed) \
if (!exclude_sensitive || !((attr_flag) & DRBD_F_SENSITIVE)) { \
DPRINT_ARRAY(">>",nla_type, name, s, NULL); \
if (__put(skb, attr_nr, min_t(int, maxlen, \
s->name ## _len + (nla_type == NLA_NUL_STRING)),\
s->name)) \
goto nla_put_failure; \
}
#include GENL_MAGIC_INCLUDE_FILE
/* Functions for initializing structs to default values. */
#undef __field
#define __field(attr_nr, attr_flag, name, nla_type, type, __get, __put, \
__is_signed)
#undef __array
#define __array(attr_nr, attr_flag, name, nla_type, type, maxlen, \
__get, __put, __is_signed)
#undef __u32_field_def
#define __u32_field_def(attr_nr, attr_flag, name, default) \
x->name = default;
#undef __s32_field_def
#define __s32_field_def(attr_nr, attr_flag, name, default) \
x->name = default;
#undef __flg_field_def
#define __flg_field_def(attr_nr, attr_flag, name, default) \
x->name = default;
#undef __str_field_def
#define __str_field_def(attr_nr, attr_flag, name, maxlen) \
memset(x->name, 0, sizeof(x->name)); \
x->name ## _len = 0;
#undef GENL_struct
#define GENL_struct(tag_name, tag_number, s_name, s_fields) \
static void set_ ## s_name ## _defaults(struct s_name *x) __attribute__((unused)); \
static void set_ ## s_name ## _defaults(struct s_name *x) { \
s_fields \
}
#include GENL_MAGIC_INCLUDE_FILE
#endif /* __KERNEL__ */
/* }}}1 */
#endif /* GENL_MAGIC_FUNC_H */
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