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 = drbd_nla_parse_nested(ntb, maxtype, tla, s_name ## _nl_policy); \
153 if (err) \
154 return err; \
155 \
156 s_fields \
157 return 0; \
158} __attribute__((unused)) \
159static int s_name ## _from_attrs(struct s_name *s, \
160 struct genl_info *info) \
161{ \
162 return __ ## s_name ## _from_attrs(s, info, false); \
163} __attribute__((unused)) \
164static int s_name ## _from_attrs_for_change(struct s_name *s, \
165 struct genl_info *info) \
166{ \
167 return __ ## s_name ## _from_attrs(s, info, true); \
168} __attribute__((unused)) \
169
170#define __assign(attr_nr, attr_flag, name, nla_type, type, assignment...) \
171 nla = ntb[attr_nr]; \
172 if (nla) { \
173 if (exclude_invariants && !!((attr_flag) & DRBD_F_INVARIANT)) { \
174 pr_info("<< must not change invariant attr: %s\n", #name); \
175 return -EEXIST; \
176 } \
177 assignment; \
178 } else if (exclude_invariants && !!((attr_flag) & DRBD_F_INVARIANT)) { \
179 /* attribute missing from payload, */ \
180 /* which was expected */ \
181 } else if ((attr_flag) & DRBD_F_REQUIRED) { \
182 pr_info("<< missing attr: %s\n", #name); \
183 return -ENOMSG; \
184 }
185
186#undef __field
187#define __field(attr_nr, attr_flag, name, nla_type, type, __get, __put, \
188 __is_signed) \
189 __assign(attr_nr, attr_flag, name, nla_type, type, \
190 if (s) \
191 s->name = __get(nla); \
192 DPRINT_FIELD("<<", nla_type, name, s, nla))
193
194/* validate_nla() already checked nla_len <= maxlen appropriately. */
195#undef __array
196#define __array(attr_nr, attr_flag, name, nla_type, type, maxlen, \
197 __get, __put, __is_signed) \
198 __assign(attr_nr, attr_flag, name, nla_type, type, \
199 if (s) \
200 s->name ## _len = \
201 __get(s->name, nla, maxlen); \
202 DPRINT_ARRAY("<<", nla_type, name, s, nla))
203
204#include GENL_MAGIC_INCLUDE_FILE
205
206#undef GENL_struct
207#define GENL_struct(tag_name, tag_number, s_name, s_fields)
208
209/*
210 * Magic: define op number to op name mapping {{{1
211 * {{{2
212 */
213static const char *CONCATENATE(GENL_MAGIC_FAMILY, _genl_cmd_to_str)(__u8 cmd)
214{
215 switch (cmd) {
216#undef GENL_op
217#define GENL_op(op_name, op_num, handler, tla_list) \
218 case op_num: return #op_name;
219#include GENL_MAGIC_INCLUDE_FILE
220 default:
221 return "unknown";
222 }
223}
224
225#ifdef __KERNEL__
226#include <linux/stringify.h>
227/*
228 * Magic: define genl_ops {{{1
229 * {{{2
230 */
231
232#undef GENL_op
233#define GENL_op(op_name, op_num, handler, tla_list) \
234{ \
235 handler \
236 .cmd = op_name, \
237},
238
239#define ZZZ_genl_ops CONCATENATE(GENL_MAGIC_FAMILY, _genl_ops)
240static struct genl_ops ZZZ_genl_ops[] __read_mostly = {
241#include GENL_MAGIC_INCLUDE_FILE
242};
243
244#undef GENL_op
245#define GENL_op(op_name, op_num, handler, tla_list)
246
247/*
248 * Define the genl_family, multicast groups, {{{1
249 * and provide register/unregister functions.
250 * {{{2
251 */
252#define ZZZ_genl_family CONCATENATE(GENL_MAGIC_FAMILY, _genl_family)
253static struct genl_family ZZZ_genl_family;
254/*
255 * Magic: define multicast groups
256 * Magic: define multicast group registration helper
257 */
258#define ZZZ_genl_mcgrps CONCATENATE(GENL_MAGIC_FAMILY, _genl_mcgrps)
259static const struct genl_multicast_group ZZZ_genl_mcgrps[] = {
260#undef GENL_mc_group
261#define GENL_mc_group(group) { .name = #group, },
262#include GENL_MAGIC_INCLUDE_FILE
263};
264
265enum CONCATENATE(GENL_MAGIC_FAMILY, group_ids) {
266#undef GENL_mc_group
267#define GENL_mc_group(group) CONCATENATE(GENL_MAGIC_FAMILY, _group_ ## group),
268#include GENL_MAGIC_INCLUDE_FILE
269};
270
271#undef GENL_mc_group
272#define GENL_mc_group(group) \
273static int CONCATENATE(GENL_MAGIC_FAMILY, _genl_multicast_ ## group)( \
274 struct sk_buff *skb, gfp_t flags) \
275{ \
276 unsigned int group_id = \
277 CONCATENATE(GENL_MAGIC_FAMILY, _group_ ## group); \
278 return genlmsg_multicast(&ZZZ_genl_family, skb, 0, \
279 group_id, flags); \
280}
281
282#include GENL_MAGIC_INCLUDE_FILE
283
284#undef GENL_mc_group
285#define GENL_mc_group(group)
286
287static struct genl_family ZZZ_genl_family __ro_after_init = {
288 .name = __stringify(GENL_MAGIC_FAMILY),
289 .version = GENL_MAGIC_VERSION,
290#ifdef GENL_MAGIC_FAMILY_HDRSZ
291 .hdrsize = NLA_ALIGN(GENL_MAGIC_FAMILY_HDRSZ),
292#endif
293 .maxattr = ARRAY_SIZE(CONCATENATE(GENL_MAGIC_FAMILY, _tla_nl_policy))-1,
294 .policy = CONCATENATE(GENL_MAGIC_FAMILY, _tla_nl_policy),
295#ifdef GENL_MAGIC_FAMILY_PRE_DOIT
296 .pre_doit = GENL_MAGIC_FAMILY_PRE_DOIT,
297 .post_doit = GENL_MAGIC_FAMILY_POST_DOIT,
298#endif
299 .ops = ZZZ_genl_ops,
300 .n_ops = ARRAY_SIZE(ZZZ_genl_ops),
301 .mcgrps = ZZZ_genl_mcgrps,
302 .resv_start_op = 42, /* drbd is currently the only user */
303 .n_mcgrps = ARRAY_SIZE(ZZZ_genl_mcgrps),
304 .module = THIS_MODULE,
305};
306
307int CONCATENATE(GENL_MAGIC_FAMILY, _genl_register)(void)
308{
309 return genl_register_family(&ZZZ_genl_family);
310}
311
312void CONCATENATE(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 */