Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef GENL_MAGIC_FUNC_H
3#define GENL_MAGIC_FUNC_H
4
5#include <linux/args.h>
6#include <linux/build_bug.h>
7#include <linux/genl_magic_struct.h>
8
9/*
10 * Magic: declare tla policy {{{1
11 * Magic: declare nested policies
12 * {{{2
13 */
14#undef GENL_mc_group
15#define GENL_mc_group(group)
16
17#undef GENL_notification
18#define GENL_notification(op_name, op_num, mcast_group, tla_list)
19
20#undef GENL_op
21#define GENL_op(op_name, op_num, handler, tla_list)
22
23#undef GENL_struct
24#define GENL_struct(tag_name, tag_number, s_name, s_fields) \
25 [tag_name] = { .type = NLA_NESTED },
26
27static struct nla_policy CONCATENATE(GENL_MAGIC_FAMILY, _tla_nl_policy)[] = {
28#include GENL_MAGIC_INCLUDE_FILE
29};
30
31#undef GENL_struct
32#define GENL_struct(tag_name, tag_number, s_name, s_fields) \
33static struct nla_policy s_name ## _nl_policy[] __read_mostly = \
34{ s_fields };
35
36#undef __field
37#define __field(attr_nr, attr_flag, name, nla_type, _type, __get, \
38 __put, __is_signed) \
39 [attr_nr] = { .type = nla_type },
40
41#undef __array
42#define __array(attr_nr, attr_flag, name, nla_type, _type, maxlen, \
43 __get, __put, __is_signed) \
44 [attr_nr] = { .type = nla_type, \
45 .len = maxlen - (nla_type == NLA_NUL_STRING) },
46
47#include GENL_MAGIC_INCLUDE_FILE
48
49#ifndef __KERNEL__
50#ifndef pr_info
51#define pr_info(args...) fprintf(stderr, args);
52#endif
53#endif
54
55#ifdef GENL_MAGIC_DEBUG
56static void dprint_field(const char *dir, int nla_type,
57 const char *name, void *valp)
58{
59 __u64 val = valp ? *(__u32 *)valp : 1;
60 switch (nla_type) {
61 case NLA_U8: val = (__u8)val;
62 case NLA_U16: val = (__u16)val;
63 case NLA_U32: val = (__u32)val;
64 pr_info("%s attr %s: %d 0x%08x\n", dir,
65 name, (int)val, (unsigned)val);
66 break;
67 case NLA_U64:
68 val = *(__u64*)valp;
69 pr_info("%s attr %s: %lld 0x%08llx\n", dir,
70 name, (long long)val, (unsigned long long)val);
71 break;
72 case NLA_FLAG:
73 if (val)
74 pr_info("%s attr %s: set\n", dir, name);
75 break;
76 }
77}
78
79static void dprint_array(const char *dir, int nla_type,
80 const char *name, const char *val, unsigned len)
81{
82 switch (nla_type) {
83 case NLA_NUL_STRING:
84 if (len && val[len-1] == '\0')
85 len--;
86 pr_info("%s attr %s: [len:%u] '%s'\n", dir, name, len, val);
87 break;
88 default:
89 /* we can always show 4 byte,
90 * thats what nlattr are aligned to. */
91 pr_info("%s attr %s: [len:%u] %02x%02x%02x%02x ...\n",
92 dir, name, len, val[0], val[1], val[2], val[3]);
93 }
94}
95
96#define DPRINT_TLA(a, op, b) pr_info("%s %s %s\n", a, op, b);
97
98/* Name is a member field name of the struct s.
99 * If s is NULL (only parsing, no copy requested in *_from_attrs()),
100 * nla is supposed to point to the attribute containing the information
101 * corresponding to that struct member. */
102#define DPRINT_FIELD(dir, nla_type, name, s, nla) \
103 do { \
104 if (s) \
105 dprint_field(dir, nla_type, #name, &s->name); \
106 else if (nla) \
107 dprint_field(dir, nla_type, #name, \
108 (nla_type == NLA_FLAG) ? NULL \
109 : nla_data(nla)); \
110 } while (0)
111
112#define DPRINT_ARRAY(dir, nla_type, name, s, nla) \
113 do { \
114 if (s) \
115 dprint_array(dir, nla_type, #name, \
116 s->name, s->name ## _len); \
117 else if (nla) \
118 dprint_array(dir, nla_type, #name, \
119 nla_data(nla), nla_len(nla)); \
120 } while (0)
121#else
122#define DPRINT_TLA(a, op, b) do {} while (0)
123#define DPRINT_FIELD(dir, nla_type, name, s, nla) do {} while (0)
124#define DPRINT_ARRAY(dir, nla_type, name, s, nla) do {} while (0)
125#endif
126
127/*
128 * Magic: provide conversion functions {{{1
129 * populate struct from attribute table:
130 * {{{2
131 */
132
133/* processing of generic netlink messages is serialized.
134 * use one static buffer for parsing of nested attributes */
135static struct nlattr *nested_attr_tb[128];
136
137#undef GENL_struct
138#define GENL_struct(tag_name, tag_number, s_name, s_fields) \
139/* *_from_attrs functions are static, but potentially unused */ \
140static int __ ## s_name ## _from_attrs(struct s_name *s, \
141 struct genl_info *info, bool exclude_invariants) \
142{ \
143 const int maxtype = ARRAY_SIZE(s_name ## _nl_policy)-1; \
144 struct nlattr *tla = info->attrs[tag_number]; \
145 struct nlattr **ntb = nested_attr_tb; \
146 struct nlattr *nla; \
147 int err; \
148 BUILD_BUG_ON(ARRAY_SIZE(s_name ## _nl_policy) > ARRAY_SIZE(nested_attr_tb)); \
149 if (!tla) \
150 return -ENOMSG; \
151 DPRINT_TLA(#s_name, "<=-", #tag_name); \
152 err = nla_parse_nested_deprecated(ntb, maxtype, tla, \
153 s_name ## _nl_policy, NULL); \
154 if (err) \
155 return err; \
156 \
157 s_fields \
158 return 0; \
159} __attribute__((unused)) \
160static int s_name ## _from_attrs(struct s_name *s, \
161 struct genl_info *info) \
162{ \
163 return __ ## s_name ## _from_attrs(s, info, false); \
164} __attribute__((unused)) \
165static int s_name ## _from_attrs_for_change(struct s_name *s, \
166 struct genl_info *info) \
167{ \
168 return __ ## s_name ## _from_attrs(s, info, true); \
169} __attribute__((unused)) \
170
171#define __assign(attr_nr, attr_flag, name, nla_type, type, assignment...) \
172 nla = ntb[attr_nr]; \
173 if (nla) { \
174 if (exclude_invariants && !!((attr_flag) & DRBD_F_INVARIANT)) { \
175 pr_info("<< must not change invariant attr: %s\n", #name); \
176 return -EEXIST; \
177 } \
178 assignment; \
179 } else if (exclude_invariants && !!((attr_flag) & DRBD_F_INVARIANT)) { \
180 /* attribute missing from payload, */ \
181 /* which was expected */ \
182 } else if ((attr_flag) & DRBD_F_REQUIRED) { \
183 pr_info("<< missing attr: %s\n", #name); \
184 return -ENOMSG; \
185 }
186
187#undef __field
188#define __field(attr_nr, attr_flag, name, nla_type, type, __get, __put, \
189 __is_signed) \
190 __assign(attr_nr, attr_flag, name, nla_type, type, \
191 if (s) \
192 s->name = __get(nla); \
193 DPRINT_FIELD("<<", nla_type, name, s, nla))
194
195/* validate_nla() already checked nla_len <= maxlen appropriately. */
196#undef __array
197#define __array(attr_nr, attr_flag, name, nla_type, type, maxlen, \
198 __get, __put, __is_signed) \
199 __assign(attr_nr, attr_flag, name, nla_type, type, \
200 if (s) \
201 s->name ## _len = \
202 __get(s->name, nla, maxlen); \
203 DPRINT_ARRAY("<<", nla_type, name, s, nla))
204
205#include GENL_MAGIC_INCLUDE_FILE
206
207#undef GENL_struct
208#define GENL_struct(tag_name, tag_number, s_name, s_fields)
209
210/*
211 * Magic: define op number to op name mapping {{{1
212 * {{{2
213 */
214static const char *CONCATENATE(GENL_MAGIC_FAMILY, _genl_cmd_to_str)(__u8 cmd)
215{
216 switch (cmd) {
217#undef GENL_op
218#define GENL_op(op_name, op_num, handler, tla_list) \
219 case op_num: return #op_name;
220#include GENL_MAGIC_INCLUDE_FILE
221 default:
222 return "unknown";
223 }
224}
225
226#ifdef __KERNEL__
227#include <linux/stringify.h>
228/*
229 * Magic: define genl_ops {{{1
230 * {{{2
231 */
232
233#undef GENL_op
234#define GENL_op(op_name, op_num, handler, tla_list) \
235{ \
236 handler \
237 .cmd = op_name, \
238},
239
240#define ZZZ_genl_ops CONCATENATE(GENL_MAGIC_FAMILY, _genl_ops)
241static struct genl_ops ZZZ_genl_ops[] __read_mostly = {
242#include GENL_MAGIC_INCLUDE_FILE
243};
244
245#undef GENL_op
246#define GENL_op(op_name, op_num, handler, tla_list)
247
248/*
249 * Define the genl_family, multicast groups, {{{1
250 * and provide register/unregister functions.
251 * {{{2
252 */
253#define ZZZ_genl_family CONCATENATE(GENL_MAGIC_FAMILY, _genl_family)
254static struct genl_family ZZZ_genl_family;
255/*
256 * Magic: define multicast groups
257 * Magic: define multicast group registration helper
258 */
259#define ZZZ_genl_mcgrps CONCATENATE(GENL_MAGIC_FAMILY, _genl_mcgrps)
260static const struct genl_multicast_group ZZZ_genl_mcgrps[] = {
261#undef GENL_mc_group
262#define GENL_mc_group(group) { .name = #group, },
263#include GENL_MAGIC_INCLUDE_FILE
264};
265
266enum CONCATENATE(GENL_MAGIC_FAMILY, group_ids) {
267#undef GENL_mc_group
268#define GENL_mc_group(group) CONCATENATE(GENL_MAGIC_FAMILY, _group_ ## group),
269#include GENL_MAGIC_INCLUDE_FILE
270};
271
272#undef GENL_mc_group
273#define GENL_mc_group(group) \
274static int CONCATENATE(GENL_MAGIC_FAMILY, _genl_multicast_ ## group)( \
275 struct sk_buff *skb, gfp_t flags) \
276{ \
277 unsigned int group_id = \
278 CONCATENATE(GENL_MAGIC_FAMILY, _group_ ## group); \
279 return genlmsg_multicast(&ZZZ_genl_family, skb, 0, \
280 group_id, flags); \
281}
282
283#include GENL_MAGIC_INCLUDE_FILE
284
285#undef GENL_mc_group
286#define GENL_mc_group(group)
287
288static struct genl_family ZZZ_genl_family __ro_after_init = {
289 .name = __stringify(GENL_MAGIC_FAMILY),
290 .version = GENL_MAGIC_VERSION,
291#ifdef GENL_MAGIC_FAMILY_HDRSZ
292 .hdrsize = NLA_ALIGN(GENL_MAGIC_FAMILY_HDRSZ),
293#endif
294 .maxattr = ARRAY_SIZE(CONCATENATE(GENL_MAGIC_FAMILY, _tla_nl_policy))-1,
295 .policy = CONCATENATE(GENL_MAGIC_FAMILY, _tla_nl_policy),
296#ifdef GENL_MAGIC_FAMILY_PRE_DOIT
297 .pre_doit = GENL_MAGIC_FAMILY_PRE_DOIT,
298 .post_doit = GENL_MAGIC_FAMILY_POST_DOIT,
299#endif
300 .ops = ZZZ_genl_ops,
301 .n_ops = ARRAY_SIZE(ZZZ_genl_ops),
302 .mcgrps = ZZZ_genl_mcgrps,
303 .resv_start_op = 42, /* drbd is currently the only user */
304 .n_mcgrps = ARRAY_SIZE(ZZZ_genl_mcgrps),
305 .module = THIS_MODULE,
306};
307
308int CONCATENATE(GENL_MAGIC_FAMILY, _genl_register)(void)
309{
310 return genl_register_family(&ZZZ_genl_family);
311}
312
313void CONCATENATE(GENL_MAGIC_FAMILY, _genl_unregister)(void)
314{
315 genl_unregister_family(&ZZZ_genl_family);
316}
317
318/*
319 * Magic: provide conversion functions {{{1
320 * populate skb from struct.
321 * {{{2
322 */
323
324#undef GENL_op
325#define GENL_op(op_name, op_num, handler, tla_list)
326
327#undef GENL_struct
328#define GENL_struct(tag_name, tag_number, s_name, s_fields) \
329static int s_name ## _to_skb(struct sk_buff *skb, struct s_name *s, \
330 const bool exclude_sensitive) \
331{ \
332 struct nlattr *tla = nla_nest_start(skb, tag_number); \
333 if (!tla) \
334 goto nla_put_failure; \
335 DPRINT_TLA(#s_name, "-=>", #tag_name); \
336 s_fields \
337 nla_nest_end(skb, tla); \
338 return 0; \
339 \
340nla_put_failure: \
341 if (tla) \
342 nla_nest_cancel(skb, tla); \
343 return -EMSGSIZE; \
344} \
345static inline int s_name ## _to_priv_skb(struct sk_buff *skb, \
346 struct s_name *s) \
347{ \
348 return s_name ## _to_skb(skb, s, 0); \
349} \
350static inline int s_name ## _to_unpriv_skb(struct sk_buff *skb, \
351 struct s_name *s) \
352{ \
353 return s_name ## _to_skb(skb, s, 1); \
354}
355
356
357#undef __field
358#define __field(attr_nr, attr_flag, name, nla_type, type, __get, __put, \
359 __is_signed) \
360 if (!exclude_sensitive || !((attr_flag) & DRBD_F_SENSITIVE)) { \
361 DPRINT_FIELD(">>", nla_type, name, s, NULL); \
362 if (__put(skb, attr_nr, s->name)) \
363 goto nla_put_failure; \
364 }
365
366#undef __array
367#define __array(attr_nr, attr_flag, name, nla_type, type, maxlen, \
368 __get, __put, __is_signed) \
369 if (!exclude_sensitive || !((attr_flag) & DRBD_F_SENSITIVE)) { \
370 DPRINT_ARRAY(">>",nla_type, name, s, NULL); \
371 if (__put(skb, attr_nr, min_t(int, maxlen, \
372 s->name ## _len + (nla_type == NLA_NUL_STRING)),\
373 s->name)) \
374 goto nla_put_failure; \
375 }
376
377#include GENL_MAGIC_INCLUDE_FILE
378
379
380/* Functions for initializing structs to default values. */
381
382#undef __field
383#define __field(attr_nr, attr_flag, name, nla_type, type, __get, __put, \
384 __is_signed)
385#undef __array
386#define __array(attr_nr, attr_flag, name, nla_type, type, maxlen, \
387 __get, __put, __is_signed)
388#undef __u32_field_def
389#define __u32_field_def(attr_nr, attr_flag, name, default) \
390 x->name = default;
391#undef __s32_field_def
392#define __s32_field_def(attr_nr, attr_flag, name, default) \
393 x->name = default;
394#undef __flg_field_def
395#define __flg_field_def(attr_nr, attr_flag, name, default) \
396 x->name = default;
397#undef __str_field_def
398#define __str_field_def(attr_nr, attr_flag, name, maxlen) \
399 memset(x->name, 0, sizeof(x->name)); \
400 x->name ## _len = 0;
401#undef GENL_struct
402#define GENL_struct(tag_name, tag_number, s_name, s_fields) \
403static void set_ ## s_name ## _defaults(struct s_name *x) __attribute__((unused)); \
404static void set_ ## s_name ## _defaults(struct s_name *x) { \
405s_fields \
406}
407
408#include GENL_MAGIC_INCLUDE_FILE
409
410#endif /* __KERNEL__ */
411
412/* }}}1 */
413#endif /* GENL_MAGIC_FUNC_H */