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