1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2022 Alexander V. Chernikov <melifaro@FreeBSD.org> 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 #ifndef _NETLINK_NETLINK_SNL_H_ 28 #define _NETLINK_NETLINK_SNL_H_ 29 30 /* 31 * Simple Netlink Library 32 */ 33 34 #include <assert.h> 35 #include <errno.h> 36 #include <stddef.h> 37 #include <stdbool.h> 38 #include <stdint.h> 39 #include <stdlib.h> 40 #include <string.h> 41 #include <unistd.h> 42 43 #include <sys/types.h> 44 #include <sys/socket.h> 45 #include <netlink/netlink.h> 46 47 48 #define _roundup2(x, y) (((x)+((y)-1))&(~((y)-1))) 49 50 #define NETLINK_ALIGN_SIZE sizeof(uint32_t) 51 #define NETLINK_ALIGN(_len) _roundup2(_len, NETLINK_ALIGN_SIZE) 52 53 #define NLA_ALIGN_SIZE sizeof(uint32_t) 54 #define NLA_HDRLEN ((int)sizeof(struct nlattr)) 55 #define NLA_DATA_LEN(_nla) ((int)((_nla)->nla_len - NLA_HDRLEN)) 56 #define NLA_DATA(_nla) NL_ITEM_DATA(_nla, NLA_HDRLEN) 57 #define NLA_DATA_CONST(_nla) NL_ITEM_DATA_CONST(_nla, NLA_HDRLEN) 58 59 #define NLA_TYPE(_nla) ((_nla)->nla_type & 0x3FFF) 60 61 #define NLA_NEXT(_attr) (struct nlattr *)(void *)((char *)_attr + NLA_ALIGN(_attr->nla_len)) 62 63 #define _NLA_END(_start, _len) ((char *)(_start) + (_len)) 64 #define NLA_FOREACH(_attr, _start, _len) \ 65 for (_attr = (_start); \ 66 ((char *)_attr < _NLA_END(_start, _len)) && \ 67 ((char *)NLA_NEXT(_attr) <= _NLA_END(_start, _len)); \ 68 _attr = NLA_NEXT(_attr)) 69 70 #define NL_ARRAY_LEN(_a) (sizeof(_a) / sizeof((_a)[0])) 71 72 struct linear_buffer { 73 char *base; /* Base allocated memory pointer */ 74 uint32_t offset; /* Currently used offset */ 75 uint32_t size; /* Total buffer size */ 76 struct linear_buffer *next; /* Buffer chaining */ 77 }; 78 79 static inline struct linear_buffer * 80 lb_init(uint32_t size) 81 { 82 struct linear_buffer *lb = calloc(1, size); 83 84 if (lb != NULL) { 85 lb->base = (char *)(lb + 1); 86 lb->size = size - sizeof(*lb); 87 } 88 89 return (lb); 90 } 91 92 static inline void 93 lb_free(struct linear_buffer *lb) 94 { 95 free(lb); 96 } 97 98 static inline char * 99 lb_allocz(struct linear_buffer *lb, int len) 100 { 101 len = roundup2(len, sizeof(uint64_t)); 102 if (lb->offset + len > lb->size) 103 return (NULL); 104 void *data = (void *)(lb->base + lb->offset); 105 lb->offset += len; 106 return (data); 107 } 108 109 static inline void 110 lb_clear(struct linear_buffer *lb) 111 { 112 memset(lb->base, 0, lb->offset); 113 lb->offset = 0; 114 } 115 116 struct snl_state { 117 int fd; 118 char *buf; 119 size_t off; 120 size_t bufsize; 121 size_t datalen; 122 uint32_t seq; 123 bool init_done; 124 struct linear_buffer *lb; 125 }; 126 #define SCRATCH_BUFFER_SIZE 1024 127 #define SNL_WRITER_BUFFER_SIZE 256 128 129 typedef void snl_parse_field_f(struct snl_state *ss, void *hdr, void *target); 130 struct snl_field_parser { 131 uint16_t off_in; 132 uint16_t off_out; 133 snl_parse_field_f *cb; 134 }; 135 136 typedef bool snl_parse_attr_f(struct snl_state *ss, struct nlattr *attr, 137 const void *arg, void *target); 138 struct snl_attr_parser { 139 uint16_t type; /* Attribute type */ 140 uint16_t off; /* field offset in the target structure */ 141 snl_parse_attr_f *cb; /* parser function to call */ 142 const void *arg; /* Optional argument parser */ 143 }; 144 145 struct snl_hdr_parser { 146 int hdr_off; /* aligned header size */ 147 int fp_size; 148 int np_size; 149 const struct snl_field_parser *fp; /* array of header field parsers */ 150 const struct snl_attr_parser *np; /* array of attribute parsers */ 151 }; 152 153 #define SNL_DECLARE_PARSER(_name, _t, _fp, _np) \ 154 static const struct snl_hdr_parser _name = { \ 155 .hdr_off = sizeof(_t), \ 156 .fp = &((_fp)[0]), \ 157 .np = &((_np)[0]), \ 158 .fp_size = NL_ARRAY_LEN(_fp), \ 159 .np_size = NL_ARRAY_LEN(_np), \ 160 } 161 162 #define SNL_DECLARE_ATTR_PARSER(_name, _np) \ 163 static const struct snl_hdr_parser _name = { \ 164 .np = &((_np)[0]), \ 165 .np_size = NL_ARRAY_LEN(_np), \ 166 } 167 168 169 static inline void * 170 snl_allocz(struct snl_state *ss, int len) 171 { 172 void *data = lb_allocz(ss->lb, len); 173 174 if (data == NULL) { 175 uint32_t size = ss->lb->size * 2; 176 177 while (size < len + sizeof(struct linear_buffer)) 178 size *= 2; 179 180 struct linear_buffer *lb = lb_init(size); 181 182 if (lb != NULL) { 183 lb->next = ss->lb; 184 ss->lb = lb; 185 data = lb_allocz(ss->lb, len); 186 } 187 } 188 189 return (data); 190 } 191 192 static inline void 193 snl_clear_lb(struct snl_state *ss) 194 { 195 struct linear_buffer *lb = ss->lb; 196 197 lb_clear(lb); 198 lb = lb->next; 199 ss->lb->next = NULL; 200 /* Remove all linear bufs except the largest one */ 201 while (lb != NULL) { 202 struct linear_buffer *lb_next = lb->next; 203 lb_free(lb); 204 lb = lb_next; 205 } 206 } 207 208 static void 209 snl_free(struct snl_state *ss) 210 { 211 if (ss->init_done) { 212 close(ss->fd); 213 if (ss->buf != NULL) 214 free(ss->buf); 215 if (ss->lb != NULL) { 216 snl_clear_lb(ss); 217 lb_free(ss->lb); 218 } 219 } 220 } 221 222 static inline bool 223 snl_init(struct snl_state *ss, int netlink_family) 224 { 225 memset(ss, 0, sizeof(*ss)); 226 227 ss->fd = socket(AF_NETLINK, SOCK_RAW, netlink_family); 228 if (ss->fd == -1) 229 return (false); 230 ss->init_done = true; 231 232 int rcvbuf; 233 socklen_t optlen = sizeof(rcvbuf); 234 if (getsockopt(ss->fd, SOL_SOCKET, SO_RCVBUF, &rcvbuf, &optlen) == -1) { 235 snl_free(ss); 236 return (false); 237 } 238 239 ss->bufsize = rcvbuf; 240 ss->buf = malloc(ss->bufsize); 241 if (ss->buf == NULL) { 242 snl_free(ss); 243 return (false); 244 } 245 246 ss->lb = lb_init(SCRATCH_BUFFER_SIZE); 247 if (ss->lb == NULL) { 248 snl_free(ss); 249 return (false); 250 } 251 252 return (true); 253 } 254 255 static inline bool 256 snl_send(struct snl_state *ss, void *data, int sz) 257 { 258 return (send(ss->fd, data, sz, 0) == sz); 259 } 260 261 static inline uint32_t 262 snl_get_seq(struct snl_state *ss) 263 { 264 return (++ss->seq); 265 } 266 267 static inline struct nlmsghdr * 268 snl_read_message(struct snl_state *ss) 269 { 270 if (ss->off == ss->datalen) { 271 struct sockaddr_nl nladdr; 272 struct iovec iov = { 273 .iov_base = ss->buf, 274 .iov_len = ss->bufsize, 275 }; 276 struct msghdr msg = { 277 .msg_name = &nladdr, 278 .msg_namelen = sizeof(nladdr), 279 .msg_iov = &iov, 280 .msg_iovlen = 1, 281 }; 282 ss->off = 0; 283 ss->datalen = 0; 284 for (;;) { 285 ssize_t datalen = recvmsg(ss->fd, &msg, 0); 286 if (datalen > 0) { 287 ss->datalen = datalen; 288 break; 289 } else if (errno != EINTR) 290 return (NULL); 291 } 292 } 293 struct nlmsghdr *hdr = (struct nlmsghdr *)(void *)&ss->buf[ss->off]; 294 ss->off += NLMSG_ALIGN(hdr->nlmsg_len); 295 return (hdr); 296 } 297 298 static inline struct nlmsghdr * 299 snl_read_reply(struct snl_state *ss, uint32_t nlmsg_seq) 300 { 301 while (true) { 302 struct nlmsghdr *hdr = snl_read_message(ss); 303 if (hdr == NULL) 304 break; 305 if (hdr->nlmsg_seq == nlmsg_seq) 306 return (hdr); 307 } 308 309 return (NULL); 310 } 311 312 static inline struct nlmsghdr * 313 snl_get_reply(struct snl_state *ss, struct nlmsghdr *hdr) 314 { 315 uint32_t nlmsg_seq = hdr->nlmsg_seq; 316 317 if (snl_send(ss, hdr, hdr->nlmsg_len)) 318 return (snl_read_reply(ss, nlmsg_seq)); 319 return (NULL); 320 } 321 322 /* 323 * Checks that attributes are sorted by attribute type. 324 */ 325 static inline void 326 snl_verify_parsers(const struct snl_hdr_parser **parser, int count) 327 { 328 for (int i = 0; i < count; i++) { 329 const struct snl_hdr_parser *p = parser[i]; 330 int attr_type = 0; 331 for (int j = 0; j < p->np_size; j++) { 332 assert(p->np[j].type > attr_type); 333 attr_type = p->np[j].type; 334 } 335 } 336 } 337 #define SNL_VERIFY_PARSERS(_p) snl_verify_parsers((_p), NL_ARRAY_LEN(_p)) 338 339 static const struct snl_attr_parser * 340 find_parser(const struct snl_attr_parser *ps, int pslen, int key) 341 { 342 int left_i = 0, right_i = pslen - 1; 343 344 if (key < ps[0].type || key > ps[pslen - 1].type) 345 return (NULL); 346 347 while (left_i + 1 < right_i) { 348 int mid_i = (left_i + right_i) / 2; 349 if (key < ps[mid_i].type) 350 right_i = mid_i; 351 else if (key > ps[mid_i].type) 352 left_i = mid_i + 1; 353 else 354 return (&ps[mid_i]); 355 } 356 if (ps[left_i].type == key) 357 return (&ps[left_i]); 358 else if (ps[right_i].type == key) 359 return (&ps[right_i]); 360 return (NULL); 361 } 362 363 static inline bool 364 snl_parse_attrs_raw(struct snl_state *ss, struct nlattr *nla_head, int len, 365 const struct snl_attr_parser *ps, int pslen, void *target) 366 { 367 struct nlattr *nla; 368 369 NLA_FOREACH(nla, nla_head, len) { 370 if (nla->nla_len < sizeof(struct nlattr)) 371 return (false); 372 int nla_type = nla->nla_type & NLA_TYPE_MASK; 373 const struct snl_attr_parser *s = find_parser(ps, pslen, nla_type); 374 if (s != NULL) { 375 void *ptr = (void *)((char *)target + s->off); 376 if (!s->cb(ss, nla, s->arg, ptr)) 377 return (false); 378 } 379 } 380 return (true); 381 } 382 383 static inline bool 384 snl_parse_attrs(struct snl_state *ss, struct nlmsghdr *hdr, int hdrlen, 385 const struct snl_attr_parser *ps, int pslen, void *target) 386 { 387 int off = NLMSG_HDRLEN + NETLINK_ALIGN(hdrlen); 388 int len = hdr->nlmsg_len - off; 389 struct nlattr *nla_head = (struct nlattr *)(void *)((char *)hdr + off); 390 391 return (snl_parse_attrs_raw(ss, nla_head, len, ps, pslen, target)); 392 } 393 394 static inline bool 395 snl_parse_header(struct snl_state *ss, void *hdr, int len, 396 const struct snl_hdr_parser *parser, void *target) 397 { 398 /* Extract fields first (if any) */ 399 for (int i = 0; i < parser->fp_size; i++) { 400 const struct snl_field_parser *fp = &parser->fp[i]; 401 void *src = (char *)hdr + fp->off_in; 402 void *dst = (char *)target + fp->off_out; 403 404 fp->cb(ss, src, dst); 405 } 406 407 struct nlattr *nla_head = (struct nlattr *)(void *)((char *)hdr + parser->hdr_off); 408 bool result = snl_parse_attrs_raw(ss, nla_head, len - parser->hdr_off, 409 parser->np, parser->np_size, target); 410 411 return (result); 412 } 413 414 static inline bool 415 snl_parse_nlmsg(struct snl_state *ss, struct nlmsghdr *hdr, 416 const struct snl_hdr_parser *parser, void *target) 417 { 418 return (snl_parse_header(ss, hdr + 1, hdr->nlmsg_len - sizeof(*hdr), parser, target)); 419 } 420 421 static inline bool 422 snl_attr_get_flag(struct snl_state *ss __unused, struct nlattr *nla, void *target) 423 { 424 if (NLA_DATA_LEN(nla) == 0) { 425 *((uint8_t *)target) = 1; 426 return (true); 427 } 428 return (false); 429 } 430 431 static inline bool 432 snl_attr_get_uint8(struct snl_state *ss __unused, struct nlattr *nla, 433 const void *arg __unused, void *target) 434 { 435 if (NLA_DATA_LEN(nla) == sizeof(uint8_t)) { 436 *((uint8_t *)target) = *((const uint8_t *)NLA_DATA_CONST(nla)); 437 return (true); 438 } 439 return (false); 440 } 441 442 static inline bool 443 snl_attr_get_uint16(struct snl_state *ss __unused, struct nlattr *nla, 444 const void *arg __unused, void *target) 445 { 446 if (NLA_DATA_LEN(nla) == sizeof(uint16_t)) { 447 *((uint16_t *)target) = *((const uint16_t *)NLA_DATA_CONST(nla)); 448 return (true); 449 } 450 return (false); 451 } 452 453 static inline bool 454 snl_attr_get_uint32(struct snl_state *ss __unused, struct nlattr *nla, 455 const void *arg __unused, void *target) 456 { 457 if (NLA_DATA_LEN(nla) == sizeof(uint32_t)) { 458 *((uint32_t *)target) = *((const uint32_t *)NLA_DATA_CONST(nla)); 459 return (true); 460 } 461 return (false); 462 } 463 464 static inline bool 465 snl_attr_get_uint64(struct snl_state *ss __unused, struct nlattr *nla, 466 const void *arg __unused, void *target) 467 { 468 if (NLA_DATA_LEN(nla) == sizeof(uint64_t)) { 469 memcpy(target, NLA_DATA_CONST(nla), sizeof(uint64_t)); 470 return (true); 471 } 472 return (false); 473 } 474 475 static inline bool 476 snl_attr_get_string(struct snl_state *ss __unused, struct nlattr *nla, 477 const void *arg __unused, void *target) 478 { 479 size_t maxlen = NLA_DATA_LEN(nla); 480 481 if (strnlen((char *)NLA_DATA(nla), maxlen) < maxlen) { 482 *((char **)target) = (char *)NLA_DATA(nla); 483 return (true); 484 } 485 return (false); 486 } 487 488 static inline bool 489 snl_attr_get_stringn(struct snl_state *ss, struct nlattr *nla, 490 const void *arg __unused, void *target) 491 { 492 int maxlen = NLA_DATA_LEN(nla); 493 494 char *buf = snl_allocz(ss, maxlen + 1); 495 if (buf == NULL) 496 return (false); 497 buf[maxlen] = '\0'; 498 memcpy(buf, NLA_DATA(nla), maxlen); 499 500 *((char **)target) = buf; 501 return (true); 502 } 503 504 static inline bool 505 snl_attr_get_nested(struct snl_state *ss, struct nlattr *nla, const void *arg, void *target) 506 { 507 const struct snl_hdr_parser *p = (const struct snl_hdr_parser *)arg; 508 509 /* Assumes target points to the beginning of the structure */ 510 return (snl_parse_header(ss, NLA_DATA(nla), NLA_DATA_LEN(nla), p, target)); 511 } 512 513 static inline bool 514 snl_attr_get_nla(struct snl_state *ss __unused, struct nlattr *nla, 515 const void *arg __unused, void *target) 516 { 517 *((struct nlattr **)target) = nla; 518 return (true); 519 } 520 521 static inline bool 522 snl_attr_copy_struct(struct snl_state *ss, struct nlattr *nla, 523 const void *arg __unused, void *target) 524 { 525 void *ptr = snl_allocz(ss, NLA_DATA_LEN(nla)); 526 527 if (ptr != NULL) { 528 memcpy(ptr, NLA_DATA(nla), NLA_DATA_LEN(nla)); 529 *((void **)target) = ptr; 530 return (true); 531 } 532 return (false); 533 } 534 535 static inline void 536 snl_field_get_uint8(struct snl_state *ss __unused, void *src, void *target) 537 { 538 *((uint8_t *)target) = *((uint8_t *)src); 539 } 540 541 static inline void 542 snl_field_get_uint16(struct snl_state *ss __unused, void *src, void *target) 543 { 544 *((uint16_t *)target) = *((uint16_t *)src); 545 } 546 547 static inline void 548 snl_field_get_uint32(struct snl_state *ss __unused, void *src, void *target) 549 { 550 *((uint32_t *)target) = *((uint32_t *)src); 551 } 552 553 struct snl_errmsg_data { 554 uint32_t nlmsg_seq; 555 int error; 556 char *error_str; 557 uint32_t error_offs; 558 struct nlattr *cookie; 559 }; 560 #define _IN(_field) offsetof(struct nlmsgerr, _field) 561 #define _OUT(_field) offsetof(struct snl_errmsg_data, _field) 562 static const struct snl_attr_parser nla_p_errmsg[] = { 563 { .type = NLMSGERR_ATTR_MSG, .off = _OUT(error_str), .cb = snl_attr_get_string }, 564 { .type = NLMSGERR_ATTR_OFFS, .off = _OUT(error_offs), .cb = snl_attr_get_uint32 }, 565 { .type = NLMSGERR_ATTR_COOKIE, .off = _OUT(cookie), .cb = snl_attr_get_nla }, 566 }; 567 568 static const struct snl_field_parser nlf_p_errmsg[] = { 569 { .off_in = _IN(error), .off_out = _OUT(error), .cb = snl_field_get_uint32 }, 570 { .off_in = _IN(msg.nlmsg_seq), .off_out = _OUT(nlmsg_seq), .cb = snl_field_get_uint32 }, 571 }; 572 #undef _IN 573 #undef _OUT 574 SNL_DECLARE_PARSER(snl_errmsg_parser, struct nlmsgerr, nlf_p_errmsg, nla_p_errmsg); 575 576 static inline bool 577 snl_check_return(struct snl_state *ss, struct nlmsghdr *hdr, struct snl_errmsg_data *e) 578 { 579 if (hdr != NULL && hdr->nlmsg_type == NLMSG_ERROR) 580 return (snl_parse_nlmsg(ss, hdr, &snl_errmsg_parser, e)); 581 return (false); 582 } 583 584 /* writer logic */ 585 struct snl_writer { 586 char *base; 587 uint32_t offset; 588 uint32_t size; 589 struct nlmsghdr *hdr; 590 struct snl_state *ss; 591 bool error; 592 }; 593 594 static inline void 595 snl_init_writer(struct snl_state *ss, struct snl_writer *nw) 596 { 597 nw->size = SNL_WRITER_BUFFER_SIZE; 598 nw->base = snl_allocz(ss, nw->size); 599 if (nw->base == NULL) { 600 nw->error = true; 601 nw->size = 0; 602 } 603 604 nw->offset = 0; 605 nw->hdr = NULL; 606 nw->error = false; 607 nw->ss = ss; 608 } 609 610 static inline bool 611 snl_realloc_msg_buffer(struct snl_writer *nw, size_t sz) 612 { 613 uint32_t new_size = nw->size * 2; 614 615 while (new_size < nw->size + sz) 616 new_size *= 2; 617 618 if (nw->error) 619 return (false); 620 621 void *new_base = snl_allocz(nw->ss, new_size); 622 if (new_base == NULL) { 623 nw->error = true; 624 return (false); 625 } 626 627 memcpy(new_base, nw->base, nw->offset); 628 if (nw->hdr != NULL) { 629 int hdr_off = (char *)(nw->hdr) - nw->base; 630 nw->hdr = (struct nlmsghdr *)(void *)((char *)new_base + hdr_off); 631 } 632 nw->base = new_base; 633 634 return (true); 635 } 636 637 static inline void * 638 snl_reserve_msg_data_raw(struct snl_writer *nw, size_t sz) 639 { 640 sz = NETLINK_ALIGN(sz); 641 642 if (__predict_false(nw->offset + sz > nw->size)) { 643 if (!snl_realloc_msg_buffer(nw, sz)) 644 return (NULL); 645 } 646 647 void *data_ptr = &nw->base[nw->offset]; 648 nw->offset += sz; 649 650 return (data_ptr); 651 } 652 #define snl_reserve_msg_object(_ns, _t) ((_t *)snl_reserve_msg_data_raw(_ns, sizeof(_t))) 653 #define snl_reserve_msg_data(_ns, _sz, _t) ((_t *)snl_reserve_msg_data_raw(_ns, _sz)) 654 655 static inline void * 656 _snl_reserve_msg_attr(struct snl_writer *nw, uint16_t nla_type, uint16_t sz) 657 { 658 sz += sizeof(struct nlattr); 659 660 struct nlattr *nla = snl_reserve_msg_data(nw, sz, struct nlattr); 661 if (__predict_false(nla == NULL)) 662 return (NULL); 663 nla->nla_type = nla_type; 664 nla->nla_len = sz; 665 666 return ((void *)(nla + 1)); 667 } 668 #define snl_reserve_msg_attr(_ns, _at, _t) ((_t *)_snl_reserve_msg_attr(_ns, _at, sizeof(_t))) 669 670 static inline bool 671 snl_add_msg_attr(struct snl_writer *nw, int attr_type, int attr_len, const void *data) 672 { 673 int required_len = NLA_ALIGN(attr_len + sizeof(struct nlattr)); 674 675 if (__predict_false(nw->offset + required_len > nw->size)) { 676 if (!snl_realloc_msg_buffer(nw, required_len)) 677 return (false); 678 } 679 680 struct nlattr *nla = (struct nlattr *)(void *)(&nw->base[nw->offset]); 681 682 nla->nla_len = attr_len + sizeof(struct nlattr); 683 nla->nla_type = attr_type; 684 if (attr_len > 0) { 685 if ((attr_len % 4) != 0) { 686 /* clear padding bytes */ 687 bzero((char *)nla + required_len - 4, 4); 688 } 689 memcpy((nla + 1), data, attr_len); 690 } 691 nw->offset += required_len; 692 return (true); 693 } 694 695 static inline bool 696 snl_add_msg_attr_raw(struct snl_writer *nw, const struct nlattr *nla_src) 697 { 698 int attr_len = nla_src->nla_len - sizeof(struct nlattr); 699 700 assert(attr_len >= 0); 701 702 return (snl_add_msg_attr(nw, nla_src->nla_type, attr_len, (const void *)(nla_src + 1))); 703 } 704 705 static inline bool 706 snl_add_msg_attr_u8(struct snl_writer *nw, int attrtype, uint8_t value) 707 { 708 return (snl_add_msg_attr(nw, attrtype, sizeof(uint8_t), &value)); 709 } 710 711 static inline bool 712 snl_add_msg_attr_u16(struct snl_writer *nw, int attrtype, uint16_t value) 713 { 714 return (snl_add_msg_attr(nw, attrtype, sizeof(uint16_t), &value)); 715 } 716 717 static inline bool 718 snl_add_msg_attr_u32(struct snl_writer *nw, int attrtype, uint32_t value) 719 { 720 return (snl_add_msg_attr(nw, attrtype, sizeof(uint32_t), &value)); 721 } 722 723 static inline bool 724 snl_add_msg_attr_u64(struct snl_writer *nw, int attrtype, uint64_t value) 725 { 726 return (snl_add_msg_attr(nw, attrtype, sizeof(uint64_t), &value)); 727 } 728 729 static inline bool 730 snl_add_msg_attr_s8(struct snl_writer *nw, int attrtype, int8_t value) 731 { 732 return (snl_add_msg_attr(nw, attrtype, sizeof(int8_t), &value)); 733 } 734 735 static inline bool 736 snl_add_msg_attr_s16(struct snl_writer *nw, int attrtype, int16_t value) 737 { 738 return (snl_add_msg_attr(nw, attrtype, sizeof(int16_t), &value)); 739 } 740 741 static inline bool 742 snl_add_msg_attr_s32(struct snl_writer *nw, int attrtype, int32_t value) 743 { 744 return (snl_add_msg_attr(nw, attrtype, sizeof(int32_t), &value)); 745 } 746 747 static inline bool 748 snl_add_msg_attr_s64(struct snl_writer *nw, int attrtype, int64_t value) 749 { 750 return (snl_add_msg_attr(nw, attrtype, sizeof(int64_t), &value)); 751 } 752 753 static inline bool 754 snl_add_msg_attr_flag(struct snl_writer *nw, int attrtype) 755 { 756 return (snl_add_msg_attr(nw, attrtype, 0, NULL)); 757 } 758 759 static inline bool 760 snl_add_msg_attr_string(struct snl_writer *nw, int attrtype, const char *str) 761 { 762 return (snl_add_msg_attr(nw, attrtype, strlen(str) + 1, str)); 763 } 764 765 766 static inline int 767 snl_get_msg_offset(const struct snl_writer *nw) 768 { 769 return (nw->offset - ((char *)nw->hdr - nw->base)); 770 } 771 772 static inline void * 773 _snl_restore_msg_offset(const struct snl_writer *nw, int off) 774 { 775 return ((void *)((char *)nw->hdr + off)); 776 } 777 #define snl_restore_msg_offset(_ns, _off, _t) ((_t *)_snl_restore_msg_offset(_ns, _off)) 778 779 static inline int 780 snl_add_msg_attr_nested(struct snl_writer *nw, int attrtype) 781 { 782 int off = snl_get_msg_offset(nw); 783 struct nlattr *nla = snl_reserve_msg_data(nw, sizeof(struct nlattr), struct nlattr); 784 if (__predict_false(nla == NULL)) 785 return (0); 786 nla->nla_type = attrtype; 787 return (off); 788 } 789 790 static inline void 791 snl_end_attr_nested(const struct snl_writer *nw, int off) 792 { 793 if (!nw->error) { 794 struct nlattr *nla = snl_restore_msg_offset(nw, off, struct nlattr); 795 nla->nla_len = NETLINK_ALIGN(snl_get_msg_offset(nw) - off); 796 } 797 } 798 799 static inline struct nlmsghdr * 800 snl_create_msg_request(struct snl_writer *nw, int nlmsg_type) 801 { 802 assert(nw->hdr == NULL); 803 804 struct nlmsghdr *hdr = snl_reserve_msg_object(nw, struct nlmsghdr); 805 hdr->nlmsg_type = nlmsg_type; 806 hdr->nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK; 807 nw->hdr = hdr; 808 809 return (hdr); 810 } 811 812 static void 813 snl_abort_msg(struct snl_writer *nw) 814 { 815 if (nw->hdr != NULL) { 816 int offset = (char *)(&nw->base[nw->offset]) - (char *)(nw->hdr); 817 818 nw->offset -= offset; 819 nw->hdr = NULL; 820 } 821 } 822 823 static inline struct nlmsghdr * 824 snl_finalize_msg(struct snl_writer *nw) 825 { 826 if (nw->error) 827 snl_abort_msg(nw); 828 if (nw->hdr != NULL) { 829 struct nlmsghdr *hdr = nw->hdr; 830 831 int offset = (char *)(&nw->base[nw->offset]) - (char *)(nw->hdr); 832 hdr->nlmsg_len = offset; 833 hdr->nlmsg_seq = snl_get_seq(nw->ss); 834 nw->hdr = NULL; 835 836 return (hdr); 837 } 838 return (NULL); 839 } 840 841 static inline bool 842 snl_send_msgs(struct snl_writer *nw) 843 { 844 int offset = nw->offset; 845 846 assert(nw->hdr == NULL); 847 nw->offset = 0; 848 849 return (snl_send(nw->ss, nw->base, offset)); 850 } 851 852 #endif 853