1#ifndef GENL_MAGIC_FUNC_H
2#define GENL_MAGIC_FUNC_H
3
4#include <linux/genl_magic_struct.h>
5
6/*
7 * Magic: declare tla policy						{{{1
8 * Magic: declare nested policies
9 *									{{{2
10 */
11#undef GENL_mc_group
12#define GENL_mc_group(group)
13
14#undef GENL_notification
15#define GENL_notification(op_name, op_num, mcast_group, tla_list)
16
17#undef GENL_op
18#define GENL_op(op_name, op_num, handler, tla_list)
19
20#undef GENL_struct
21#define GENL_struct(tag_name, tag_number, s_name, s_fields)		\
22	[tag_name] = { .type = NLA_NESTED },
23
24static struct nla_policy CONCAT_(GENL_MAGIC_FAMILY, _tla_nl_policy)[] = {
25#include GENL_MAGIC_INCLUDE_FILE
26};
27
28#undef GENL_struct
29#define GENL_struct(tag_name, tag_number, s_name, s_fields)		\
30static struct nla_policy s_name ## _nl_policy[] __read_mostly =		\
31{ s_fields };
32
33#undef __field
34#define __field(attr_nr, attr_flag, name, nla_type, _type, __get,	\
35		 __put, __is_signed)					\
36	[attr_nr] = { .type = nla_type },
37
38#undef __array
39#define __array(attr_nr, attr_flag, name, nla_type, _type, maxlen,	\
40		__get, __put, __is_signed)				\
41	[attr_nr] = { .type = nla_type,					\
42		      .len = maxlen - (nla_type == NLA_NUL_STRING) },
43
44#include GENL_MAGIC_INCLUDE_FILE
45
46#ifndef __KERNEL__
47#ifndef pr_info
48#define pr_info(args...)	fprintf(stderr, args);
49#endif
50#endif
51
52#ifdef GENL_MAGIC_DEBUG
53static void dprint_field(const char *dir, int nla_type,
54		const char *name, void *valp)
55{
56	__u64 val = valp ? *(__u32 *)valp : 1;
57	switch (nla_type) {
58	case NLA_U8:  val = (__u8)val;
59	case NLA_U16: val = (__u16)val;
60	case NLA_U32: val = (__u32)val;
61		pr_info("%s attr %s: %d 0x%08x\n", dir,
62			name, (int)val, (unsigned)val);
63		break;
64	case NLA_U64:
65		val = *(__u64*)valp;
66		pr_info("%s attr %s: %lld 0x%08llx\n", dir,
67			name, (long long)val, (unsigned long long)val);
68		break;
69	case NLA_FLAG:
70		if (val)
71			pr_info("%s attr %s: set\n", dir, name);
72		break;
73	}
74}
75
76static void dprint_array(const char *dir, int nla_type,
77		const char *name, const char *val, unsigned len)
78{
79	switch (nla_type) {
80	case NLA_NUL_STRING:
81		if (len && val[len-1] == '\0')
82			len--;
83		pr_info("%s attr %s: [len:%u] '%s'\n", dir, name, len, val);
84		break;
85	default:
86		/* we can always show 4 byte,
87		 * thats what nlattr are aligned to. */
88		pr_info("%s attr %s: [len:%u] %02x%02x%02x%02x ...\n",
89			dir, name, len, val[0], val[1], val[2], val[3]);
90	}
91}
92
93#define DPRINT_TLA(a, op, b) pr_info("%s %s %s\n", a, op, b);
94
95/* Name is a member field name of the struct s.
96 * If s is NULL (only parsing, no copy requested in *_from_attrs()),
97 * nla is supposed to point to the attribute containing the information
98 * corresponding to that struct member. */
99#define DPRINT_FIELD(dir, nla_type, name, s, nla)			\
100	do {								\
101		if (s)							\
102			dprint_field(dir, nla_type, #name, &s->name);	\
103		else if (nla)						\
104			dprint_field(dir, nla_type, #name,		\
105				(nla_type == NLA_FLAG) ? NULL		\
106						: nla_data(nla));	\
107	} while (0)
108
109#define	DPRINT_ARRAY(dir, nla_type, name, s, nla)			\
110	do {								\
111		if (s)							\
112			dprint_array(dir, nla_type, #name,		\
113					s->name, s->name ## _len);	\
114		else if (nla)						\
115			dprint_array(dir, nla_type, #name,		\
116					nla_data(nla), nla_len(nla));	\
117	} while (0)
118#else
119#define DPRINT_TLA(a, op, b) do {} while (0)
120#define DPRINT_FIELD(dir, nla_type, name, s, nla) do {} while (0)
121#define	DPRINT_ARRAY(dir, nla_type, name, s, nla) do {} while (0)
122#endif
123
124/*
125 * Magic: provide conversion functions					{{{1
126 * populate struct from attribute table:
127 *									{{{2
128 */
129
130/* processing of generic netlink messages is serialized.
131 * use one static buffer for parsing of nested attributes */
132static struct nlattr *nested_attr_tb[128];
133
134#ifndef BUILD_BUG_ON
135/* Force a compilation error if condition is true */
136#define BUILD_BUG_ON(condition) ((void)BUILD_BUG_ON_ZERO(condition))
137/* Force a compilation error if condition is true, but also produce a
138   result (of value 0 and type size_t), so the expression can be used
139   e.g. in a structure initializer (or where-ever else comma expressions
140   aren't permitted). */
141#define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:-!!(e); }))
142#define BUILD_BUG_ON_NULL(e) ((void *)sizeof(struct { int:-!!(e); }))
143#endif
144
145#undef GENL_struct
146#define GENL_struct(tag_name, tag_number, s_name, s_fields)		\
147/* *_from_attrs functions are static, but potentially unused */		\
148static int __ ## s_name ## _from_attrs(struct s_name *s,		\
149		struct genl_info *info, bool exclude_invariants)	\
150{									\
151	const int maxtype = ARRAY_SIZE(s_name ## _nl_policy)-1;		\
152	struct nlattr *tla = info->attrs[tag_number];			\
153	struct nlattr **ntb = nested_attr_tb;				\
154	struct nlattr *nla;						\
155	int err;							\
156	BUILD_BUG_ON(ARRAY_SIZE(s_name ## _nl_policy) > ARRAY_SIZE(nested_attr_tb));	\
157	if (!tla)							\
158		return -ENOMSG;						\
159	DPRINT_TLA(#s_name, "<=-", #tag_name);				\
160	err = drbd_nla_parse_nested(ntb, maxtype, tla, s_name ## _nl_policy);	\
161	if (err)							\
162		return err;						\
163									\
164	s_fields							\
165	return 0;							\
166}					__attribute__((unused))		\
167static int s_name ## _from_attrs(struct s_name *s,			\
168						struct genl_info *info)	\
169{									\
170	return __ ## s_name ## _from_attrs(s, info, false);		\
171}					__attribute__((unused))		\
172static int s_name ## _from_attrs_for_change(struct s_name *s,		\
173						struct genl_info *info)	\
174{									\
175	return __ ## s_name ## _from_attrs(s, info, true);		\
176}					__attribute__((unused))		\
177
178#define __assign(attr_nr, attr_flag, name, nla_type, type, assignment...)	\
179		nla = ntb[attr_nr];						\
180		if (nla) {						\
181			if (exclude_invariants && !!((attr_flag) & DRBD_F_INVARIANT)) {		\
182				pr_info("<< must not change invariant attr: %s\n", #name);	\
183				return -EEXIST;				\
184			}						\
185			assignment;					\
186		} else if (exclude_invariants && !!((attr_flag) & DRBD_F_INVARIANT)) {		\
187			/* attribute missing from payload, */		\
188			/* which was expected */			\
189		} else if ((attr_flag) & DRBD_F_REQUIRED) {		\
190			pr_info("<< missing attr: %s\n", #name);	\
191			return -ENOMSG;					\
192		}
193
194#undef __field
195#define __field(attr_nr, attr_flag, name, nla_type, type, __get, __put,	\
196		__is_signed)						\
197	__assign(attr_nr, attr_flag, name, nla_type, type,		\
198			if (s)						\
199				s->name = __get(nla);			\
200			DPRINT_FIELD("<<", nla_type, name, s, nla))
201
202/* validate_nla() already checked nla_len <= maxlen appropriately. */
203#undef __array
204#define __array(attr_nr, attr_flag, name, nla_type, type, maxlen,	\
205		__get, __put, __is_signed)				\
206	__assign(attr_nr, attr_flag, name, nla_type, type,		\
207			if (s)						\
208				s->name ## _len =			\
209					__get(s->name, nla, maxlen);	\
210			DPRINT_ARRAY("<<", nla_type, name, s, nla))
211
212#include GENL_MAGIC_INCLUDE_FILE
213
214#undef GENL_struct
215#define GENL_struct(tag_name, tag_number, s_name, s_fields)
216
217/*
218 * Magic: define op number to op name mapping				{{{1
219 *									{{{2
220 */
221const char *CONCAT_(GENL_MAGIC_FAMILY, _genl_cmd_to_str)(__u8 cmd)
222{
223	switch (cmd) {
224#undef GENL_op
225#define GENL_op(op_name, op_num, handler, tla_list)		\
226	case op_num: return #op_name;
227#include GENL_MAGIC_INCLUDE_FILE
228	default:
229		     return "unknown";
230	}
231}
232
233#ifdef __KERNEL__
234#include <linux/stringify.h>
235/*
236 * Magic: define genl_ops						{{{1
237 *									{{{2
238 */
239
240#undef GENL_op
241#define GENL_op(op_name, op_num, handler, tla_list)		\
242{								\
243	handler							\
244	.cmd = op_name,						\
245	.policy	= CONCAT_(GENL_MAGIC_FAMILY, _tla_nl_policy),	\
246},
247
248#define ZZZ_genl_ops		CONCAT_(GENL_MAGIC_FAMILY, _genl_ops)
249static struct genl_ops ZZZ_genl_ops[] __read_mostly = {
250#include GENL_MAGIC_INCLUDE_FILE
251};
252
253#undef GENL_op
254#define GENL_op(op_name, op_num, handler, tla_list)
255
256/*
257 * Define the genl_family, multicast groups,				{{{1
258 * and provide register/unregister functions.
259 *									{{{2
260 */
261#define ZZZ_genl_family		CONCAT_(GENL_MAGIC_FAMILY, _genl_family)
262static struct genl_family ZZZ_genl_family __read_mostly = {
263	.id = GENL_ID_GENERATE,
264	.name = __stringify(GENL_MAGIC_FAMILY),
265	.version = GENL_MAGIC_VERSION,
266#ifdef GENL_MAGIC_FAMILY_HDRSZ
267	.hdrsize = NLA_ALIGN(GENL_MAGIC_FAMILY_HDRSZ),
268#endif
269	.maxattr = ARRAY_SIZE(drbd_tla_nl_policy)-1,
270};
271
272/*
273 * Magic: define multicast groups
274 * Magic: define multicast group registration helper
275 */
276#define ZZZ_genl_mcgrps		CONCAT_(GENL_MAGIC_FAMILY, _genl_mcgrps)
277static const struct genl_multicast_group ZZZ_genl_mcgrps[] = {
278#undef GENL_mc_group
279#define GENL_mc_group(group) { .name = #group, },
280#include GENL_MAGIC_INCLUDE_FILE
281};
282
283enum CONCAT_(GENL_MAGIC_FAMILY, group_ids) {
284#undef GENL_mc_group
285#define GENL_mc_group(group) CONCAT_(GENL_MAGIC_FAMILY, _group_ ## group),
286#include GENL_MAGIC_INCLUDE_FILE
287};
288
289#undef GENL_mc_group
290#define GENL_mc_group(group)						\
291static int CONCAT_(GENL_MAGIC_FAMILY, _genl_multicast_ ## group)(	\
292	struct sk_buff *skb, gfp_t flags)				\
293{									\
294	unsigned int group_id =						\
295		CONCAT_(GENL_MAGIC_FAMILY, _group_ ## group);		\
296	return genlmsg_multicast(&ZZZ_genl_family, skb, 0,		\
297				 group_id, flags);			\
298}
299
300#include GENL_MAGIC_INCLUDE_FILE
301
302#undef GENL_mc_group
303#define GENL_mc_group(group)
304
305int CONCAT_(GENL_MAGIC_FAMILY, _genl_register)(void)
306{
307	return genl_register_family_with_ops_groups(&ZZZ_genl_family,	\
308						    ZZZ_genl_ops,	\
309						    ZZZ_genl_mcgrps);
310}
311
312void CONCAT_(GENL_MAGIC_FAMILY, _genl_unregister)(void)
313{
314	genl_unregister_family(&ZZZ_genl_family);
315}
316
317/*
318 * Magic: provide conversion functions					{{{1
319 * populate skb from struct.
320 *									{{{2
321 */
322
323#undef GENL_op
324#define GENL_op(op_name, op_num, handler, tla_list)
325
326#undef GENL_struct
327#define GENL_struct(tag_name, tag_number, s_name, s_fields)		\
328static int s_name ## _to_skb(struct sk_buff *skb, struct s_name *s,	\
329		const bool exclude_sensitive)				\
330{									\
331	struct nlattr *tla = nla_nest_start(skb, tag_number);		\
332	if (!tla)							\
333		goto nla_put_failure;					\
334	DPRINT_TLA(#s_name, "-=>", #tag_name);				\
335	s_fields							\
336	nla_nest_end(skb, tla);						\
337	return 0;							\
338									\
339nla_put_failure:							\
340	if (tla)							\
341		nla_nest_cancel(skb, tla);				\
342        return -EMSGSIZE;						\
343}									\
344static inline int s_name ## _to_priv_skb(struct sk_buff *skb,		\
345		struct s_name *s)					\
346{									\
347	return s_name ## _to_skb(skb, s, 0);				\
348}									\
349static inline int s_name ## _to_unpriv_skb(struct sk_buff *skb,		\
350		struct s_name *s)					\
351{									\
352	return s_name ## _to_skb(skb, s, 1);				\
353}
354
355
356#undef __field
357#define __field(attr_nr, attr_flag, name, nla_type, type, __get, __put,	\
358		__is_signed)						\
359	if (!exclude_sensitive || !((attr_flag) & DRBD_F_SENSITIVE)) {	\
360		DPRINT_FIELD(">>", nla_type, name, s, NULL);		\
361		if (__put(skb, attr_nr, s->name))			\
362			goto nla_put_failure;				\
363	}
364
365#undef __array
366#define __array(attr_nr, attr_flag, name, nla_type, type, maxlen,	\
367		__get, __put, __is_signed)				\
368	if (!exclude_sensitive || !((attr_flag) & DRBD_F_SENSITIVE)) {	\
369		DPRINT_ARRAY(">>",nla_type, name, s, NULL);		\
370		if (__put(skb, attr_nr, min_t(int, maxlen,		\
371			s->name ## _len + (nla_type == NLA_NUL_STRING)),\
372						s->name))		\
373			goto nla_put_failure;				\
374	}
375
376#include GENL_MAGIC_INCLUDE_FILE
377
378
379/* Functions for initializing structs to default values.  */
380
381#undef __field
382#define __field(attr_nr, attr_flag, name, nla_type, type, __get, __put,	\
383		__is_signed)
384#undef __array
385#define __array(attr_nr, attr_flag, name, nla_type, type, maxlen,	\
386		__get, __put, __is_signed)
387#undef __u32_field_def
388#define __u32_field_def(attr_nr, attr_flag, name, default)		\
389	x->name = default;
390#undef __s32_field_def
391#define __s32_field_def(attr_nr, attr_flag, name, default)		\
392	x->name = default;
393#undef __flg_field_def
394#define __flg_field_def(attr_nr, attr_flag, name, default)		\
395	x->name = default;
396#undef __str_field_def
397#define __str_field_def(attr_nr, attr_flag, name, maxlen)		\
398	memset(x->name, 0, sizeof(x->name));				\
399	x->name ## _len = 0;
400#undef GENL_struct
401#define GENL_struct(tag_name, tag_number, s_name, s_fields)		\
402static void set_ ## s_name ## _defaults(struct s_name *x) __attribute__((unused)); \
403static void set_ ## s_name ## _defaults(struct s_name *x) {	\
404s_fields								\
405}
406
407#include GENL_MAGIC_INCLUDE_FILE
408
409#endif /* __KERNEL__ */
410
411/* }}}1 */
412#endif /* GENL_MAGIC_FUNC_H */
413/* vim: set foldmethod=marker foldlevel=1 nofoldenable : */
414