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 24 static 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) \ 30 static 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 53 static 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 76 static 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 */ 132 static 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 */ \ 148 static 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)) \ 167 static 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)) \ 172 static 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 */ 221 const 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) 249 static 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) 262 static 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) 277 static 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 }; 282 283 enum 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) \ 291 static 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) 304 305 int 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 } 311 312 void 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) \ 328 static 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 \ 339 nla_put_failure: \ 340 if (tla) \ 341 nla_nest_cancel(skb, tla); \ 342 return -EMSGSIZE; \ 343 } \ 344 static 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 } \ 349 static 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) \ 402 static void set_ ## s_name ## _defaults(struct s_name *x) __attribute__((unused)); \ 403 static void set_ ## s_name ## _defaults(struct s_name *x) { \ 404 s_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