1 /* SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause */ 2 #ifndef __YNL_C_PRIV_H 3 #define __YNL_C_PRIV_H 1 4 5 #include <stdbool.h> 6 #include <stddef.h> 7 #include <linux/types.h> 8 9 struct ynl_parse_arg; 10 11 /* 12 * YNL internals / low level stuff 13 */ 14 15 enum ynl_policy_type { 16 YNL_PT_REJECT = 1, 17 YNL_PT_IGNORE, 18 YNL_PT_NEST, 19 YNL_PT_FLAG, 20 YNL_PT_BINARY, 21 YNL_PT_U8, 22 YNL_PT_U16, 23 YNL_PT_U32, 24 YNL_PT_U64, 25 YNL_PT_UINT, 26 YNL_PT_NUL_STR, 27 YNL_PT_BITFIELD32, 28 YNL_PT_SUBMSG, 29 }; 30 31 enum ynl_parse_result { 32 YNL_PARSE_CB_ERROR = -1, 33 YNL_PARSE_CB_STOP = 0, 34 YNL_PARSE_CB_OK = 1, 35 }; 36 37 #define YNL_SOCKET_BUFFER_SIZE (1 << 17) 38 39 #define YNL_ARRAY_SIZE(array) (sizeof(array) ? \ 40 sizeof(array) / sizeof(array[0]) : 0) 41 42 typedef int (*ynl_parse_cb_t)(const struct nlmsghdr *nlh, 43 struct ynl_parse_arg *yarg); 44 45 struct ynl_policy_attr { 46 enum ynl_policy_type type:8; 47 __u8 is_submsg:1; 48 __u8 is_selector:1; 49 __u16 selector_type; 50 unsigned int len; 51 const char *name; 52 const struct ynl_policy_nest *nest; 53 }; 54 55 struct ynl_policy_nest { 56 unsigned int max_attr; 57 const struct ynl_policy_attr *table; 58 }; 59 60 struct ynl_parse_arg { 61 struct ynl_sock *ys; 62 const struct ynl_policy_nest *rsp_policy; 63 void *data; 64 }; 65 66 struct ynl_dump_list_type { 67 struct ynl_dump_list_type *next; 68 unsigned char data[] __attribute__((aligned(8))); 69 }; 70 extern struct ynl_dump_list_type *YNL_LIST_END; 71 72 static inline bool ynl_dump_obj_is_last(void *obj) 73 { 74 unsigned long uptr = (unsigned long)obj; 75 76 uptr -= offsetof(struct ynl_dump_list_type, data); 77 return uptr == (unsigned long)YNL_LIST_END; 78 } 79 80 static inline void *ynl_dump_obj_next(void *obj) 81 { 82 unsigned long uptr = (unsigned long)obj; 83 struct ynl_dump_list_type *list; 84 85 uptr -= offsetof(struct ynl_dump_list_type, data); 86 list = (struct ynl_dump_list_type *)uptr; 87 uptr = (unsigned long)list->next; 88 uptr += offsetof(struct ynl_dump_list_type, data); 89 90 return (void *)uptr; 91 } 92 93 struct ynl_ntf_base_type { 94 __u16 family; 95 __u8 cmd; 96 struct ynl_ntf_base_type *next; 97 void (*free)(struct ynl_ntf_base_type *ntf); 98 unsigned char data[] __attribute__((aligned(8))); 99 }; 100 101 struct nlmsghdr *ynl_msg_start_req(struct ynl_sock *ys, __u32 id, __u16 flags); 102 struct nlmsghdr *ynl_msg_start_dump(struct ynl_sock *ys, __u32 id); 103 104 struct nlmsghdr * 105 ynl_gemsg_start_req(struct ynl_sock *ys, __u32 id, __u8 cmd, __u8 version); 106 struct nlmsghdr * 107 ynl_gemsg_start_dump(struct ynl_sock *ys, __u32 id, __u8 cmd, __u8 version); 108 109 int ynl_attr_validate(struct ynl_parse_arg *yarg, const struct nlattr *attr); 110 int ynl_submsg_failed(struct ynl_parse_arg *yarg, const char *field_name, 111 const char *sel_name); 112 113 /* YNL specific helpers used by the auto-generated code */ 114 115 struct ynl_req_state { 116 struct ynl_parse_arg yarg; 117 ynl_parse_cb_t cb; 118 __u32 rsp_cmd; 119 }; 120 121 struct ynl_dump_state { 122 struct ynl_parse_arg yarg; 123 void *first; 124 struct ynl_dump_list_type *last; 125 size_t alloc_sz; 126 ynl_parse_cb_t cb; 127 __u32 rsp_cmd; 128 }; 129 130 struct ynl_ntf_info { 131 const struct ynl_policy_nest *policy; 132 ynl_parse_cb_t cb; 133 size_t alloc_sz; 134 void (*free)(struct ynl_ntf_base_type *ntf); 135 }; 136 137 int ynl_exec(struct ynl_sock *ys, struct nlmsghdr *req_nlh, 138 struct ynl_req_state *yrs); 139 int ynl_exec_dump(struct ynl_sock *ys, struct nlmsghdr *req_nlh, 140 struct ynl_dump_state *yds); 141 142 void ynl_error_unknown_notification(struct ynl_sock *ys, __u8 cmd); 143 int ynl_error_parse(struct ynl_parse_arg *yarg, const char *msg); 144 145 /* Netlink message handling helpers */ 146 147 #define YNL_MSG_OVERFLOW 1 148 149 static inline struct nlmsghdr *ynl_nlmsg_put_header(void *buf) 150 { 151 struct nlmsghdr *nlh = (struct nlmsghdr *)buf; 152 153 memset(nlh, 0, sizeof(*nlh)); 154 nlh->nlmsg_len = NLMSG_HDRLEN; 155 156 return nlh; 157 } 158 159 static inline unsigned int ynl_nlmsg_data_len(const struct nlmsghdr *nlh) 160 { 161 return nlh->nlmsg_len - NLMSG_HDRLEN; 162 } 163 164 static inline void *ynl_nlmsg_data(const struct nlmsghdr *nlh) 165 { 166 return (unsigned char *)nlh + NLMSG_HDRLEN; 167 } 168 169 static inline void * 170 ynl_nlmsg_data_offset(const struct nlmsghdr *nlh, unsigned int offset) 171 { 172 return (unsigned char *)nlh + NLMSG_HDRLEN + offset; 173 } 174 175 static inline void *ynl_nlmsg_end_addr(const struct nlmsghdr *nlh) 176 { 177 return (char *)nlh + nlh->nlmsg_len; 178 } 179 180 static inline void * 181 ynl_nlmsg_put_extra_header(struct nlmsghdr *nlh, unsigned int size) 182 { 183 void *tail = ynl_nlmsg_end_addr(nlh); 184 185 nlh->nlmsg_len += NLMSG_ALIGN(size); 186 return tail; 187 } 188 189 /* Netlink attribute helpers */ 190 191 static inline unsigned int ynl_attr_type(const struct nlattr *attr) 192 { 193 return attr->nla_type & NLA_TYPE_MASK; 194 } 195 196 static inline unsigned int ynl_attr_data_len(const struct nlattr *attr) 197 { 198 return attr->nla_len - NLA_HDRLEN; 199 } 200 201 static inline void *ynl_attr_data(const struct nlattr *attr) 202 { 203 return (unsigned char *)attr + NLA_HDRLEN; 204 } 205 206 static inline void *ynl_attr_data_end(const struct nlattr *attr) 207 { 208 return (char *)ynl_attr_data(attr) + ynl_attr_data_len(attr); 209 } 210 211 #define ynl_attr_for_each(attr, nlh, fixed_hdr_sz) \ 212 for ((attr) = ynl_attr_first(nlh, (nlh)->nlmsg_len, \ 213 NLMSG_HDRLEN + fixed_hdr_sz); attr; \ 214 (attr) = ynl_attr_next(ynl_nlmsg_end_addr(nlh), attr)) 215 216 #define ynl_attr_for_each_nested(attr, outer) \ 217 for ((attr) = ynl_attr_first(outer, outer->nla_len, \ 218 sizeof(struct nlattr)); attr; \ 219 (attr) = ynl_attr_next(ynl_attr_data_end(outer), attr)) 220 221 #define ynl_attr_for_each_payload(start, len, attr) \ 222 for ((attr) = ynl_attr_first(start, len, 0); attr; \ 223 (attr) = ynl_attr_next(start + len, attr)) 224 225 static inline struct nlattr * 226 ynl_attr_if_good(const void *end, struct nlattr *attr) 227 { 228 if (attr + 1 > (const struct nlattr *)end) 229 return NULL; 230 if (ynl_attr_data_end(attr) > end) 231 return NULL; 232 return attr; 233 } 234 235 static inline struct nlattr * 236 ynl_attr_next(const void *end, const struct nlattr *prev) 237 { 238 struct nlattr *attr; 239 240 attr = (struct nlattr *)((char *)prev + NLA_ALIGN(prev->nla_len)); 241 return ynl_attr_if_good(end, attr); 242 } 243 244 static inline struct nlattr * 245 ynl_attr_first(const void *start, size_t len, size_t skip) 246 { 247 struct nlattr *attr; 248 249 attr = (struct nlattr *)((char *)start + NLMSG_ALIGN(skip)); 250 return ynl_attr_if_good((char *)start + len, attr); 251 } 252 253 static inline bool 254 __ynl_attr_put_overflow(struct nlmsghdr *nlh, size_t size) 255 { 256 bool o; 257 258 /* ynl_msg_start() stashed buffer length in nlmsg_pid. */ 259 o = nlh->nlmsg_len + NLA_HDRLEN + NLMSG_ALIGN(size) > nlh->nlmsg_pid; 260 if (o) 261 /* YNL_MSG_OVERFLOW is < NLMSG_HDRLEN, all subsequent checks 262 * are guaranteed to fail. 263 */ 264 nlh->nlmsg_pid = YNL_MSG_OVERFLOW; 265 return o; 266 } 267 268 static inline struct nlattr * 269 ynl_attr_nest_start(struct nlmsghdr *nlh, unsigned int attr_type) 270 { 271 struct nlattr *attr; 272 273 if (__ynl_attr_put_overflow(nlh, 0)) 274 return (struct nlattr *)ynl_nlmsg_end_addr(nlh) - 1; 275 276 attr = (struct nlattr *)ynl_nlmsg_end_addr(nlh); 277 attr->nla_type = attr_type | NLA_F_NESTED; 278 nlh->nlmsg_len += NLA_HDRLEN; 279 280 return attr; 281 } 282 283 static inline void 284 ynl_attr_nest_end(struct nlmsghdr *nlh, struct nlattr *attr) 285 { 286 attr->nla_len = (char *)ynl_nlmsg_end_addr(nlh) - (char *)attr; 287 } 288 289 static inline void 290 ynl_attr_put(struct nlmsghdr *nlh, unsigned int attr_type, 291 const void *value, size_t size) 292 { 293 struct nlattr *attr; 294 295 if (__ynl_attr_put_overflow(nlh, size)) 296 return; 297 298 attr = (struct nlattr *)ynl_nlmsg_end_addr(nlh); 299 attr->nla_type = attr_type; 300 attr->nla_len = NLA_HDRLEN + size; 301 302 memcpy(ynl_attr_data(attr), value, size); 303 304 nlh->nlmsg_len += NLMSG_ALIGN(attr->nla_len); 305 } 306 307 static inline void 308 ynl_attr_put_str(struct nlmsghdr *nlh, unsigned int attr_type, const char *str) 309 { 310 struct nlattr *attr; 311 size_t len; 312 313 len = strlen(str); 314 if (__ynl_attr_put_overflow(nlh, len)) 315 return; 316 317 attr = (struct nlattr *)ynl_nlmsg_end_addr(nlh); 318 attr->nla_type = attr_type; 319 320 strcpy((char *)ynl_attr_data(attr), str); 321 attr->nla_len = NLA_HDRLEN + NLA_ALIGN(len); 322 323 nlh->nlmsg_len += NLMSG_ALIGN(attr->nla_len); 324 } 325 326 static inline const char *ynl_attr_get_str(const struct nlattr *attr) 327 { 328 return (const char *)ynl_attr_data(attr); 329 } 330 331 static inline __s8 ynl_attr_get_s8(const struct nlattr *attr) 332 { 333 return *(__s8 *)ynl_attr_data(attr); 334 } 335 336 static inline __s16 ynl_attr_get_s16(const struct nlattr *attr) 337 { 338 return *(__s16 *)ynl_attr_data(attr); 339 } 340 341 static inline __s32 ynl_attr_get_s32(const struct nlattr *attr) 342 { 343 return *(__s32 *)ynl_attr_data(attr); 344 } 345 346 static inline __s64 ynl_attr_get_s64(const struct nlattr *attr) 347 { 348 __s64 tmp; 349 350 memcpy(&tmp, (unsigned char *)(attr + 1), sizeof(tmp)); 351 return tmp; 352 } 353 354 static inline __u8 ynl_attr_get_u8(const struct nlattr *attr) 355 { 356 return *(__u8 *)ynl_attr_data(attr); 357 } 358 359 static inline __u16 ynl_attr_get_u16(const struct nlattr *attr) 360 { 361 return *(__u16 *)ynl_attr_data(attr); 362 } 363 364 static inline __u32 ynl_attr_get_u32(const struct nlattr *attr) 365 { 366 return *(__u32 *)ynl_attr_data(attr); 367 } 368 369 static inline __u64 ynl_attr_get_u64(const struct nlattr *attr) 370 { 371 __u64 tmp; 372 373 memcpy(&tmp, (unsigned char *)(attr + 1), sizeof(tmp)); 374 return tmp; 375 } 376 377 static inline void 378 ynl_attr_put_s8(struct nlmsghdr *nlh, unsigned int attr_type, __s8 value) 379 { 380 ynl_attr_put(nlh, attr_type, &value, sizeof(value)); 381 } 382 383 static inline void 384 ynl_attr_put_s16(struct nlmsghdr *nlh, unsigned int attr_type, __s16 value) 385 { 386 ynl_attr_put(nlh, attr_type, &value, sizeof(value)); 387 } 388 389 static inline void 390 ynl_attr_put_s32(struct nlmsghdr *nlh, unsigned int attr_type, __s32 value) 391 { 392 ynl_attr_put(nlh, attr_type, &value, sizeof(value)); 393 } 394 395 static inline void 396 ynl_attr_put_s64(struct nlmsghdr *nlh, unsigned int attr_type, __s64 value) 397 { 398 ynl_attr_put(nlh, attr_type, &value, sizeof(value)); 399 } 400 401 static inline void 402 ynl_attr_put_u8(struct nlmsghdr *nlh, unsigned int attr_type, __u8 value) 403 { 404 ynl_attr_put(nlh, attr_type, &value, sizeof(value)); 405 } 406 407 static inline void 408 ynl_attr_put_u16(struct nlmsghdr *nlh, unsigned int attr_type, __u16 value) 409 { 410 ynl_attr_put(nlh, attr_type, &value, sizeof(value)); 411 } 412 413 static inline void 414 ynl_attr_put_u32(struct nlmsghdr *nlh, unsigned int attr_type, __u32 value) 415 { 416 ynl_attr_put(nlh, attr_type, &value, sizeof(value)); 417 } 418 419 static inline void 420 ynl_attr_put_u64(struct nlmsghdr *nlh, unsigned int attr_type, __u64 value) 421 { 422 ynl_attr_put(nlh, attr_type, &value, sizeof(value)); 423 } 424 425 static inline __u64 ynl_attr_get_uint(const struct nlattr *attr) 426 { 427 switch (ynl_attr_data_len(attr)) { 428 case 4: 429 return ynl_attr_get_u32(attr); 430 case 8: 431 return ynl_attr_get_u64(attr); 432 default: 433 return 0; 434 } 435 } 436 437 static inline __s64 ynl_attr_get_sint(const struct nlattr *attr) 438 { 439 switch (ynl_attr_data_len(attr)) { 440 case 4: 441 return ynl_attr_get_s32(attr); 442 case 8: 443 return ynl_attr_get_s64(attr); 444 default: 445 return 0; 446 } 447 } 448 449 static inline void 450 ynl_attr_put_uint(struct nlmsghdr *nlh, __u16 type, __u64 data) 451 { 452 if ((__u32)data == (__u64)data) 453 ynl_attr_put_u32(nlh, type, data); 454 else 455 ynl_attr_put_u64(nlh, type, data); 456 } 457 458 static inline void 459 ynl_attr_put_sint(struct nlmsghdr *nlh, __u16 type, __s64 data) 460 { 461 if ((__s32)data == (__s64)data) 462 ynl_attr_put_s32(nlh, type, data); 463 else 464 ynl_attr_put_s64(nlh, type, data); 465 } 466 #endif 467