Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
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linux
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#undef GENL_mc_group
277#define GENL_mc_group(group) \
278static struct genl_multicast_group \
279CONCAT_(GENL_MAGIC_FAMILY, _mcg_ ## group) __read_mostly = { \
280 .name = #group, \
281}; \
282static int CONCAT_(GENL_MAGIC_FAMILY, _genl_multicast_ ## group)( \
283 struct sk_buff *skb, gfp_t flags) \
284{ \
285 unsigned int group_id = \
286 CONCAT_(GENL_MAGIC_FAMILY, _mcg_ ## group).id; \
287 if (!group_id) \
288 return -EINVAL; \
289 return genlmsg_multicast(skb, 0, group_id, flags); \
290}
291
292#include GENL_MAGIC_INCLUDE_FILE
293
294int CONCAT_(GENL_MAGIC_FAMILY, _genl_register)(void)
295{
296 int err = genl_register_family_with_ops(&ZZZ_genl_family,
297 ZZZ_genl_ops, ARRAY_SIZE(ZZZ_genl_ops));
298 if (err)
299 return err;
300#undef GENL_mc_group
301#define GENL_mc_group(group) \
302 err = genl_register_mc_group(&ZZZ_genl_family, \
303 &CONCAT_(GENL_MAGIC_FAMILY, _mcg_ ## group)); \
304 if (err) \
305 goto fail; \
306 else \
307 pr_info("%s: mcg %s: %u\n", #group, \
308 __stringify(GENL_MAGIC_FAMILY), \
309 CONCAT_(GENL_MAGIC_FAMILY, _mcg_ ## group).id);
310
311#include GENL_MAGIC_INCLUDE_FILE
312
313#undef GENL_mc_group
314#define GENL_mc_group(group)
315 return 0;
316fail:
317 genl_unregister_family(&ZZZ_genl_family);
318 return err;
319}
320
321void CONCAT_(GENL_MAGIC_FAMILY, _genl_unregister)(void)
322{
323 genl_unregister_family(&ZZZ_genl_family);
324}
325
326/*
327 * Magic: provide conversion functions {{{1
328 * populate skb from struct.
329 * {{{2
330 */
331
332#undef GENL_op
333#define GENL_op(op_name, op_num, handler, tla_list)
334
335#undef GENL_struct
336#define GENL_struct(tag_name, tag_number, s_name, s_fields) \
337static int s_name ## _to_skb(struct sk_buff *skb, struct s_name *s, \
338 const bool exclude_sensitive) \
339{ \
340 struct nlattr *tla = nla_nest_start(skb, tag_number); \
341 if (!tla) \
342 goto nla_put_failure; \
343 DPRINT_TLA(#s_name, "-=>", #tag_name); \
344 s_fields \
345 nla_nest_end(skb, tla); \
346 return 0; \
347 \
348nla_put_failure: \
349 if (tla) \
350 nla_nest_cancel(skb, tla); \
351 return -EMSGSIZE; \
352} \
353static inline int s_name ## _to_priv_skb(struct sk_buff *skb, \
354 struct s_name *s) \
355{ \
356 return s_name ## _to_skb(skb, s, 0); \
357} \
358static inline int s_name ## _to_unpriv_skb(struct sk_buff *skb, \
359 struct s_name *s) \
360{ \
361 return s_name ## _to_skb(skb, s, 1); \
362}
363
364
365#undef __field
366#define __field(attr_nr, attr_flag, name, nla_type, type, __get, __put, \
367 __is_signed) \
368 if (!exclude_sensitive || !((attr_flag) & DRBD_F_SENSITIVE)) { \
369 DPRINT_FIELD(">>", nla_type, name, s, NULL); \
370 if (__put(skb, attr_nr, s->name)) \
371 goto nla_put_failure; \
372 }
373
374#undef __array
375#define __array(attr_nr, attr_flag, name, nla_type, type, maxlen, \
376 __get, __put, __is_signed) \
377 if (!exclude_sensitive || !((attr_flag) & DRBD_F_SENSITIVE)) { \
378 DPRINT_ARRAY(">>",nla_type, name, s, NULL); \
379 if (__put(skb, attr_nr, min_t(int, maxlen, \
380 s->name ## _len + (nla_type == NLA_NUL_STRING)),\
381 s->name)) \
382 goto nla_put_failure; \
383 }
384
385#include GENL_MAGIC_INCLUDE_FILE
386
387
388/* Functions for initializing structs to default values. */
389
390#undef __field
391#define __field(attr_nr, attr_flag, name, nla_type, type, __get, __put, \
392 __is_signed)
393#undef __array
394#define __array(attr_nr, attr_flag, name, nla_type, type, maxlen, \
395 __get, __put, __is_signed)
396#undef __u32_field_def
397#define __u32_field_def(attr_nr, attr_flag, name, default) \
398 x->name = default;
399#undef __s32_field_def
400#define __s32_field_def(attr_nr, attr_flag, name, default) \
401 x->name = default;
402#undef __flg_field_def
403#define __flg_field_def(attr_nr, attr_flag, name, default) \
404 x->name = default;
405#undef __str_field_def
406#define __str_field_def(attr_nr, attr_flag, name, maxlen) \
407 memset(x->name, 0, sizeof(x->name)); \
408 x->name ## _len = 0;
409#undef GENL_struct
410#define GENL_struct(tag_name, tag_number, s_name, s_fields) \
411static void set_ ## s_name ## _defaults(struct s_name *x) __attribute__((unused)); \
412static void set_ ## s_name ## _defaults(struct s_name *x) { \
413s_fields \
414}
415
416#include GENL_MAGIC_INCLUDE_FILE
417
418#endif /* __KERNEL__ */
419
420/* }}}1 */
421#endif /* GENL_MAGIC_FUNC_H */
422/* vim: set foldmethod=marker foldlevel=1 nofoldenable : */