1/*- 2 * SPDX-License-Identifier: BSD-2-Clause 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 <stdalign.h> 37#include <stddef.h> 38#include <stdbool.h> 39#include <stdint.h> 40#include <stdlib.h> 41#include <string.h> 42#include <unistd.h> 43 44#include <sys/types.h> 45#include <sys/socket.h> 46#include <netlink/netlink.h> 47#include <netlink/netlink_bitset.h> 48 49#define _roundup2(x, y) (((x)+((y)-1))&(~((y)-1))) 50 51#define NETLINK_ALIGN_SIZE sizeof(uint32_t) 52#define NETLINK_ALIGN(_len) _roundup2(_len, NETLINK_ALIGN_SIZE) 53 54#define NLA_ALIGN_SIZE sizeof(uint32_t) 55#define NLA_HDRLEN ((int)sizeof(struct nlattr)) 56#define NLA_DATA_LEN(_nla) ((int)((_nla)->nla_len - NLA_HDRLEN)) 57#define NLA_DATA(_nla) NL_ITEM_DATA(_nla, NLA_HDRLEN) 58#define NLA_DATA_CONST(_nla) NL_ITEM_DATA_CONST(_nla, NLA_HDRLEN) 59 60#define NLA_TYPE(_nla) ((_nla)->nla_type & 0x3FFF) 61 62#define NLA_NEXT(_attr) (struct nlattr *)(void *)((char *)_attr + NLA_ALIGN(_attr->nla_len)) 63 64#define _NLA_END(_start, _len) ((char *)(_start) + (_len)) 65#define NLA_FOREACH(_attr, _start, _len) \ 66 for (_attr = (struct nlattr *)(_start); \ 67 ((char *)_attr < _NLA_END(_start, _len)) && \ 68 ((char *)NLA_NEXT(_attr) <= _NLA_END(_start, _len)); \ 69 _attr = NLA_NEXT(_attr)) 70 71#define NL_ARRAY_LEN(_a) (sizeof(_a) / sizeof((_a)[0])) 72 73struct linear_buffer { 74 char *base; /* Base allocated memory pointer */ 75 uint32_t offset; /* Currently used offset */ 76 uint32_t size; /* Total buffer size */ 77 struct linear_buffer *next; /* Buffer chaining */ 78} __aligned(alignof(__max_align_t)); 79 80static inline struct linear_buffer * 81lb_init(uint32_t size) 82{ 83 struct linear_buffer *lb = (struct linear_buffer *)calloc(1, size); 84 85 if (lb != NULL) { 86 lb->base = (char *)(lb + 1); 87 lb->size = size - sizeof(*lb); 88 } 89 90 return (lb); 91} 92 93static inline void 94lb_free(struct linear_buffer *lb) 95{ 96 free(lb); 97} 98 99static inline char * 100lb_allocz(struct linear_buffer *lb, int len) 101{ 102 len = roundup2(len, alignof(__max_align_t)); 103 if (lb->offset + len > lb->size) 104 return (NULL); 105 char *data = (lb->base + lb->offset); 106 lb->offset += len; 107 return (data); 108} 109 110static inline void 111lb_clear(struct linear_buffer *lb) 112{ 113 memset(lb->base, 0, lb->offset); 114 lb->offset = 0; 115} 116 117struct snl_state { 118 int fd; 119 char *buf; 120 size_t off; 121 size_t bufsize; 122 size_t datalen; 123 uint32_t seq; 124 bool init_done; 125 struct linear_buffer *lb; 126}; 127#define SCRATCH_BUFFER_SIZE 1024 128#define SNL_WRITER_BUFFER_SIZE 256 129 130typedef void snl_parse_field_f(struct snl_state *ss, void *hdr, void *target); 131struct snl_field_parser { 132 uint16_t off_in; 133 uint16_t off_out; 134 snl_parse_field_f *cb; 135}; 136 137typedef bool snl_parse_attr_f(struct snl_state *ss, struct nlattr *attr, 138 const void *arg, void *target); 139struct snl_attr_parser { 140 uint16_t type; /* Attribute type */ 141 uint16_t off; /* field offset in the target structure */ 142 snl_parse_attr_f *cb; /* parser function to call */ 143 144 /* Optional parser argument */ 145 union { 146 const void *arg; 147 const uint32_t arg_u32; 148 }; 149}; 150 151typedef bool snl_parse_post_f(struct snl_state *ss, void *target); 152 153struct snl_hdr_parser { 154 uint16_t in_hdr_size; /* Input header size */ 155 uint16_t out_size; /* Output structure size */ 156 uint16_t fp_size; /* Number of items in field parser */ 157 uint16_t np_size; /* Number of items in attribute parser */ 158 const struct snl_field_parser *fp; /* array of header field parsers */ 159 const struct snl_attr_parser *np; /* array of attribute parsers */ 160 snl_parse_post_f *cb_post; /* post-parse callback */ 161}; 162 163#define SNL_DECLARE_PARSER_EXT(_name, _sz_h_in, _sz_out, _fp, _np, _cb) \ 164static const struct snl_hdr_parser _name = { \ 165 .in_hdr_size = _sz_h_in, \ 166 .out_size = _sz_out, \ 167 .fp = &((_fp)[0]), \ 168 .np = &((_np)[0]), \ 169 .fp_size = NL_ARRAY_LEN(_fp), \ 170 .np_size = NL_ARRAY_LEN(_np), \ 171 .cb_post = _cb, \ 172} 173 174#define SNL_DECLARE_PARSER(_name, _t, _fp, _np) \ 175 SNL_DECLARE_PARSER_EXT(_name, sizeof(_t), 0, _fp, _np, NULL) 176 177#define SNL_DECLARE_FIELD_PARSER_EXT(_name, _sz_h_in, _sz_out, _fp, _cb) \ 178static const struct snl_hdr_parser _name = { \ 179 .in_hdr_size = _sz_h_in, \ 180 .out_size = _sz_out, \ 181 .fp = &((_fp)[0]), \ 182 .fp_size = NL_ARRAY_LEN(_fp), \ 183 .cb_post = _cb, \ 184} 185 186#define SNL_DECLARE_FIELD_PARSER(_name, _t, _fp) \ 187 SNL_DECLARE_FIELD_PARSER_EXT(_name, sizeof(_t), 0, _fp, NULL) 188 189#define SNL_DECLARE_ATTR_PARSER_EXT(_name, _sz_out, _np, _cb) \ 190static const struct snl_hdr_parser _name = { \ 191 .out_size = _sz_out, \ 192 .np = &((_np)[0]), \ 193 .np_size = NL_ARRAY_LEN(_np), \ 194 .cb_post = _cb, \ 195} 196 197#define SNL_DECLARE_ATTR_PARSER(_name, _np) \ 198 SNL_DECLARE_ATTR_PARSER_EXT(_name, 0, _np, NULL) 199 200 201static inline void * 202snl_allocz(struct snl_state *ss, int len) 203{ 204 void *data = lb_allocz(ss->lb, len); 205 206 if (data == NULL) { 207 uint32_t size = ss->lb->size * 2; 208 209 while (size < len + sizeof(struct linear_buffer)) 210 size *= 2; 211 212 struct linear_buffer *lb = lb_init(size); 213 214 if (lb != NULL) { 215 lb->next = ss->lb; 216 ss->lb = lb; 217 data = lb_allocz(ss->lb, len); 218 } 219 } 220 221 return (data); 222} 223 224static inline void 225snl_clear_lb(struct snl_state *ss) 226{ 227 struct linear_buffer *lb = ss->lb; 228 229 lb_clear(lb); 230 lb = lb->next; 231 ss->lb->next = NULL; 232 /* Remove all linear bufs except the largest one */ 233 while (lb != NULL) { 234 struct linear_buffer *lb_next = lb->next; 235 lb_free(lb); 236 lb = lb_next; 237 } 238} 239 240static void 241snl_free(struct snl_state *ss) 242{ 243 if (ss->init_done) { 244 close(ss->fd); 245 if (ss->buf != NULL) 246 free(ss->buf); 247 if (ss->lb != NULL) { 248 snl_clear_lb(ss); 249 lb_free(ss->lb); 250 } 251 } 252} 253 254static inline bool 255snl_init(struct snl_state *ss, int netlink_family) 256{ 257 memset(ss, 0, sizeof(*ss)); 258 259 ss->fd = socket(AF_NETLINK, SOCK_RAW, netlink_family); 260 if (ss->fd == -1) 261 return (false); 262 ss->init_done = true; 263 264 int val = 1; 265 socklen_t optlen = sizeof(val); 266 if (setsockopt(ss->fd, SOL_NETLINK, NETLINK_EXT_ACK, &val, optlen) == -1) { 267 snl_free(ss); 268 return (false); 269 } 270 271 int rcvbuf; 272 if (getsockopt(ss->fd, SOL_SOCKET, SO_RCVBUF, &rcvbuf, &optlen) == -1) { 273 snl_free(ss); 274 return (false); 275 } 276 277 ss->bufsize = rcvbuf; 278 ss->buf = (char *)malloc(ss->bufsize); 279 if (ss->buf == NULL) { 280 snl_free(ss); 281 return (false); 282 } 283 284 ss->lb = lb_init(SCRATCH_BUFFER_SIZE); 285 if (ss->lb == NULL) { 286 snl_free(ss); 287 return (false); 288 } 289 290 return (true); 291} 292 293static inline bool 294snl_send(struct snl_state *ss, void *data, int sz) 295{ 296 return (send(ss->fd, data, sz, 0) == sz); 297} 298 299static inline bool 300snl_send_message(struct snl_state *ss, struct nlmsghdr *hdr) 301{ 302 ssize_t sz = NLMSG_ALIGN(hdr->nlmsg_len); 303 304 return (send(ss->fd, hdr, sz, 0) == sz); 305} 306 307static inline uint32_t 308snl_get_seq(struct snl_state *ss) 309{ 310 return (++ss->seq); 311} 312 313struct snl_msg_info { 314 int cmsg_type; 315 int cmsg_level; 316 uint32_t process_id; 317 uint8_t port_id; 318 uint8_t seq_id; 319}; 320static inline bool parse_cmsg(struct snl_state *ss, const struct msghdr *msg, 321 struct snl_msg_info *attrs); 322 323static inline struct nlmsghdr * 324snl_read_message_dbg(struct snl_state *ss, struct snl_msg_info *cinfo) 325{ 326 memset(cinfo, 0, sizeof(*cinfo)); 327 328 if (ss->off == ss->datalen) { 329 struct sockaddr_nl nladdr; 330 char cbuf[64]; 331 332 struct iovec iov = { 333 .iov_base = ss->buf, 334 .iov_len = ss->bufsize, 335 }; 336 struct msghdr msg = { 337 .msg_name = &nladdr, 338 .msg_namelen = sizeof(nladdr), 339 .msg_iov = &iov, 340 .msg_iovlen = 1, 341 .msg_control = cbuf, 342 .msg_controllen = sizeof(cbuf), 343 }; 344 ss->off = 0; 345 ss->datalen = 0; 346 for (;;) { 347 ssize_t datalen = recvmsg(ss->fd, &msg, 0); 348 if (datalen > 0) { 349 ss->datalen = datalen; 350 parse_cmsg(ss, &msg, cinfo); 351 break; 352 } else if (errno != EINTR) 353 return (NULL); 354 } 355 } 356 struct nlmsghdr *hdr = (struct nlmsghdr *)(void *)&ss->buf[ss->off]; 357 ss->off += NLMSG_ALIGN(hdr->nlmsg_len); 358 return (hdr); 359} 360 361 362static inline struct nlmsghdr * 363snl_read_message(struct snl_state *ss) 364{ 365 if (ss->off == ss->datalen) { 366 struct sockaddr_nl nladdr; 367 struct iovec iov = { 368 .iov_base = ss->buf, 369 .iov_len = ss->bufsize, 370 }; 371 struct msghdr msg = { 372 .msg_name = &nladdr, 373 .msg_namelen = sizeof(nladdr), 374 .msg_iov = &iov, 375 .msg_iovlen = 1, 376 }; 377 ss->off = 0; 378 ss->datalen = 0; 379 for (;;) { 380 ssize_t datalen = recvmsg(ss->fd, &msg, 0); 381 if (datalen > 0) { 382 ss->datalen = datalen; 383 break; 384 } else if (errno != EINTR) 385 return (NULL); 386 } 387 } 388 struct nlmsghdr *hdr = (struct nlmsghdr *)(void *)&ss->buf[ss->off]; 389 ss->off += NLMSG_ALIGN(hdr->nlmsg_len); 390 return (hdr); 391} 392 393static inline struct nlmsghdr * 394snl_read_reply(struct snl_state *ss, uint32_t nlmsg_seq) 395{ 396 struct nlmsghdr *hdr; 397 398 while ((hdr = snl_read_message(ss)) != NULL) { 399 if (hdr->nlmsg_seq == nlmsg_seq) 400 return (hdr); 401 } 402 403 return (NULL); 404} 405 406/* 407 * Checks that attributes are sorted by attribute type. 408 */ 409static inline void 410snl_verify_parsers(const struct snl_hdr_parser **parser, int count) 411{ 412 for (int i = 0; i < count; i++) { 413 const struct snl_hdr_parser *p = parser[i]; 414 int attr_type = 0; 415 for (int j = 0; j < p->np_size; j++) { 416 assert(p->np[j].type > attr_type); 417 attr_type = p->np[j].type; 418 } 419 } 420} 421#define SNL_VERIFY_PARSERS(_p) snl_verify_parsers((_p), NL_ARRAY_LEN(_p)) 422 423static const struct snl_attr_parser * 424find_parser(const struct snl_attr_parser *ps, int pslen, int key) 425{ 426 int left_i = 0, right_i = pslen - 1; 427 428 if (key < ps[0].type || key > ps[pslen - 1].type) 429 return (NULL); 430 431 while (left_i + 1 < right_i) { 432 int mid_i = (left_i + right_i) / 2; 433 if (key < ps[mid_i].type) 434 right_i = mid_i; 435 else if (key > ps[mid_i].type) 436 left_i = mid_i + 1; 437 else 438 return (&ps[mid_i]); 439 } 440 if (ps[left_i].type == key) 441 return (&ps[left_i]); 442 else if (ps[right_i].type == key) 443 return (&ps[right_i]); 444 return (NULL); 445} 446 447static inline bool 448snl_parse_attrs_raw(struct snl_state *ss, struct nlattr *nla_head, int len, 449 const struct snl_attr_parser *ps, int pslen, void *target) 450{ 451 struct nlattr *nla; 452 453 NLA_FOREACH(nla, nla_head, len) { 454 if (nla->nla_len < sizeof(struct nlattr)) 455 return (false); 456 int nla_type = nla->nla_type & NLA_TYPE_MASK; 457 const struct snl_attr_parser *s = find_parser(ps, pslen, nla_type); 458 if (s != NULL) { 459 void *ptr = (void *)((char *)target + s->off); 460 if (!s->cb(ss, nla, s->arg, ptr)) 461 return (false); 462 } 463 } 464 return (true); 465} 466 467static inline bool 468snl_parse_attrs(struct snl_state *ss, struct nlmsghdr *hdr, int hdrlen, 469 const struct snl_attr_parser *ps, int pslen, void *target) 470{ 471 int off = NLMSG_HDRLEN + NETLINK_ALIGN(hdrlen); 472 int len = hdr->nlmsg_len - off; 473 struct nlattr *nla_head = (struct nlattr *)(void *)((char *)hdr + off); 474 475 return (snl_parse_attrs_raw(ss, nla_head, len, ps, pslen, target)); 476} 477 478static inline void 479snl_parse_fields(struct snl_state *ss, struct nlmsghdr *hdr, int hdrlen __unused, 480 const struct snl_field_parser *ps, int pslen, void *target) 481{ 482 for (int i = 0; i < pslen; i++) { 483 const struct snl_field_parser *fp = &ps[i]; 484 void *src = (char *)hdr + fp->off_in; 485 void *dst = (char *)target + fp->off_out; 486 487 fp->cb(ss, src, dst); 488 } 489} 490 491static inline bool 492snl_parse_header(struct snl_state *ss, void *hdr, int len, 493 const struct snl_hdr_parser *parser, void *target) 494{ 495 struct nlattr *nla_head; 496 497 /* Extract fields first (if any) */ 498 snl_parse_fields(ss, (struct nlmsghdr *)hdr, parser->in_hdr_size, 499 parser->fp, parser->fp_size, target); 500 501 nla_head = (struct nlattr *)(void *)((char *)hdr + parser->in_hdr_size); 502 bool result = snl_parse_attrs_raw(ss, nla_head, len - parser->in_hdr_size, 503 parser->np, parser->np_size, target); 504 505 if (result && parser->cb_post != NULL) 506 result = parser->cb_post(ss, target); 507 508 return (result); 509} 510 511static inline bool 512snl_parse_nlmsg(struct snl_state *ss, struct nlmsghdr *hdr, 513 const struct snl_hdr_parser *parser, void *target) 514{ 515 return (snl_parse_header(ss, hdr + 1, hdr->nlmsg_len - sizeof(*hdr), parser, target)); 516} 517 518static inline bool 519snl_attr_get_flag(struct snl_state *ss __unused, struct nlattr *nla, const void *arg __unused, 520 void *target) 521{ 522 if (NLA_DATA_LEN(nla) == 0) { 523 *((uint8_t *)target) = 1; 524 return (true); 525 } 526 return (false); 527} 528 529static inline bool 530snl_attr_get_bytes(struct snl_state *ss __unused, struct nlattr *nla, const void *arg, 531 void *target) 532{ 533 if ((size_t)NLA_DATA_LEN(nla) != (size_t)arg) 534 return (false); 535 536 memcpy(target, NLA_DATA_CONST(nla), (size_t)arg); 537 538 return (true); 539} 540 541static inline bool 542snl_attr_get_bool(struct snl_state *ss __unused, struct nlattr *nla, 543 const void *arg __unused, void *target) 544{ 545 if (NLA_DATA_LEN(nla) == sizeof(bool)) { 546 *((bool *)target) = *((const bool *)NLA_DATA_CONST(nla)); 547 return (true); 548 } 549 return (false); 550} 551 552static inline bool 553snl_attr_get_uint8(struct snl_state *ss __unused, struct nlattr *nla, 554 const void *arg __unused, void *target) 555{ 556 if (NLA_DATA_LEN(nla) == sizeof(uint8_t)) { 557 *((uint8_t *)target) = *((const uint8_t *)NLA_DATA_CONST(nla)); 558 return (true); 559 } 560 return (false); 561} 562 563static inline bool 564snl_attr_get_uint16(struct snl_state *ss __unused, struct nlattr *nla, 565 const void *arg __unused, void *target) 566{ 567 if (NLA_DATA_LEN(nla) == sizeof(uint16_t)) { 568 *((uint16_t *)target) = *((const uint16_t *)NLA_DATA_CONST(nla)); 569 return (true); 570 } 571 return (false); 572} 573 574static inline bool 575snl_attr_get_uint32(struct snl_state *ss __unused, struct nlattr *nla, 576 const void *arg __unused, void *target) 577{ 578 if (NLA_DATA_LEN(nla) == sizeof(uint32_t)) { 579 *((uint32_t *)target) = *((const uint32_t *)NLA_DATA_CONST(nla)); 580 return (true); 581 } 582 return (false); 583} 584 585static inline bool 586snl_attr_get_uint64(struct snl_state *ss __unused, struct nlattr *nla, 587 const void *arg __unused, void *target) 588{ 589 if (NLA_DATA_LEN(nla) == sizeof(uint64_t)) { 590 memcpy(target, NLA_DATA_CONST(nla), sizeof(uint64_t)); 591 return (true); 592 } 593 return (false); 594} 595 596static inline bool 597snl_attr_get_int8(struct snl_state *ss, struct nlattr *nla, const void *arg, 598 void *target) 599{ 600 return (snl_attr_get_uint8(ss, nla, arg, target)); 601} 602 603static inline bool 604snl_attr_get_int16(struct snl_state *ss, struct nlattr *nla, const void *arg, 605 void *target) 606{ 607 return (snl_attr_get_uint16(ss, nla, arg, target)); 608} 609 610static inline bool 611snl_attr_get_int32(struct snl_state *ss, struct nlattr *nla, const void *arg, 612 void *target) 613{ 614 return (snl_attr_get_uint32(ss, nla, arg, target)); 615} 616 617static inline bool 618snl_attr_get_int64(struct snl_state *ss, struct nlattr *nla, const void *arg, 619 void *target) 620{ 621 return (snl_attr_get_uint64(ss, nla, arg, target)); 622} 623 624static inline bool 625snl_attr_get_string(struct snl_state *ss __unused, struct nlattr *nla, 626 const void *arg __unused, void *target) 627{ 628 size_t maxlen = NLA_DATA_LEN(nla); 629 630 if (strnlen((char *)NLA_DATA(nla), maxlen) < maxlen) { 631 *((char **)target) = (char *)NLA_DATA(nla); 632 return (true); 633 } 634 return (false); 635} 636 637static inline bool 638snl_attr_get_stringn(struct snl_state *ss, struct nlattr *nla, 639 const void *arg __unused, void *target) 640{ 641 int maxlen = NLA_DATA_LEN(nla); 642 643 char *buf = (char *)snl_allocz(ss, maxlen + 1); 644 if (buf == NULL) 645 return (false); 646 buf[maxlen] = '\0'; 647 memcpy(buf, NLA_DATA(nla), maxlen); 648 649 *((char **)target) = buf; 650 return (true); 651} 652 653static inline bool 654snl_attr_copy_string(struct snl_state *ss, struct nlattr *nla, 655 const void *arg, void *target) 656{ 657 char *tmp; 658 659 if (snl_attr_get_string(ss, nla, NULL, &tmp)) { 660 strlcpy((char *)target, tmp, (size_t)arg); 661 return (true); 662 } 663 return (false); 664} 665 666static inline bool 667snl_attr_dup_string(struct snl_state *ss __unused, struct nlattr *nla, 668 const void *arg __unused, void *target) 669{ 670 size_t maxlen = NLA_DATA_LEN(nla); 671 672 if (strnlen((char *)NLA_DATA(nla), maxlen) < maxlen) { 673 char *buf = (char *)snl_allocz(ss, maxlen); 674 if (buf == NULL) 675 return (false); 676 memcpy(buf, NLA_DATA(nla), maxlen); 677 *((char **)target) = buf; 678 return (true); 679 } 680 return (false); 681} 682 683static inline bool 684snl_attr_get_nested(struct snl_state *ss, struct nlattr *nla, const void *arg, void *target) 685{ 686 const struct snl_hdr_parser *p = (const struct snl_hdr_parser *)arg; 687 688 /* Assumes target points to the beginning of the structure */ 689 return (snl_parse_header(ss, NLA_DATA(nla), NLA_DATA_LEN(nla), p, target)); 690} 691 692struct snl_parray { 693 uint32_t count; 694 void **items; 695}; 696 697static inline bool 698snl_attr_get_parray_sz(struct snl_state *ss, struct nlattr *container_nla, 699 uint32_t start_size, const void *arg, void *target) 700{ 701 const struct snl_hdr_parser *p = (const struct snl_hdr_parser *)arg; 702 struct snl_parray *array = (struct snl_parray *)target; 703 struct nlattr *nla; 704 uint32_t count = 0, size = start_size; 705 706 if (p->out_size == 0) 707 return (false); 708 709 array->items = (void **)snl_allocz(ss, size * sizeof(void *)); 710 if (array->items == NULL) 711 return (false); 712 713 /* 714 * If the provided parser is an attribute parser, assume that each 715 * nla in the container nla is the container nla itself and parse 716 * the contents of this nla. 717 * Otherwise, run the parser on raw data, assuming the header of this 718 * data has u16 field with total size in the beginning. 719 */ 720 uint32_t data_off = 0; 721 722 if (p->in_hdr_size == 0) 723 data_off = sizeof(struct nlattr); 724 725 NLA_FOREACH(nla, NLA_DATA(container_nla), NLA_DATA_LEN(container_nla)) { 726 void *item = snl_allocz(ss, p->out_size); 727 728 if (item == NULL) 729 return (false); 730 731 void *data = (char *)(void *)nla + data_off; 732 int data_len = nla->nla_len - data_off; 733 734 if (!(snl_parse_header(ss, data, data_len, p, item))) 735 return (false); 736 737 if (count == size) { 738 uint32_t new_size = size * 2; 739 void **new_array = (void **)snl_allocz(ss, new_size *sizeof(void *)); 740 741 memcpy(new_array, array->items, size * sizeof(void *)); 742 array->items = new_array; 743 size = new_size; 744 } 745 array->items[count++] = item; 746 } 747 array->count = count; 748 749 return (true); 750} 751 752/* 753 * Parses and stores the unknown-size array. 754 * Assumes each array item is a container and the NLAs in the container are parsable 755 * by the parser provided in @arg. 756 * Assumes @target is struct snl_parray 757 */ 758static inline bool 759snl_attr_get_parray(struct snl_state *ss, struct nlattr *nla, const void *arg, void *target) 760{ 761 return (snl_attr_get_parray_sz(ss, nla, 8, arg, target)); 762} 763 764static inline bool 765snl_attr_get_nla(struct snl_state *ss __unused, struct nlattr *nla, 766 const void *arg __unused, void *target) 767{ 768 *((struct nlattr **)target) = nla; 769 return (true); 770} 771 772static inline bool 773snl_attr_dup_nla(struct snl_state *ss, struct nlattr *nla, 774 const void *arg __unused, void *target) 775{ 776 void *ptr = snl_allocz(ss, nla->nla_len); 777 778 if (ptr != NULL) { 779 memcpy(ptr, nla, nla->nla_len); 780 *((void **)target) = ptr; 781 return (true); 782 } 783 return (false); 784} 785 786static inline bool 787snl_attr_copy_struct(struct snl_state *ss, struct nlattr *nla, 788 const void *arg __unused, void *target) 789{ 790 void *ptr = snl_allocz(ss, NLA_DATA_LEN(nla)); 791 792 if (ptr != NULL) { 793 memcpy(ptr, NLA_DATA(nla), NLA_DATA_LEN(nla)); 794 *((void **)target) = ptr; 795 return (true); 796 } 797 return (false); 798} 799 800static inline bool 801snl_attr_dup_struct(struct snl_state *ss, struct nlattr *nla, 802 const void *arg __unused, void *target) 803{ 804 void *ptr = snl_allocz(ss, NLA_DATA_LEN(nla)); 805 806 if (ptr != NULL) { 807 memcpy(ptr, NLA_DATA(nla), NLA_DATA_LEN(nla)); 808 *((void **)target) = ptr; 809 return (true); 810 } 811 return (false); 812} 813 814struct snl_attr_bit { 815 uint32_t bit_index; 816 char *bit_name; 817 int bit_value; 818}; 819 820struct snl_attr_bits { 821 uint32_t num_bits; 822 struct snl_attr_bit **bits; 823}; 824 825#define _OUT(_field) offsetof(struct snl_attr_bit, _field) 826static const struct snl_attr_parser _nla_p_bit[] = { 827 { .type = NLA_BITSET_BIT_INDEX, .off = _OUT(bit_index), .cb = snl_attr_get_uint32 }, 828 { .type = NLA_BITSET_BIT_NAME, .off = _OUT(bit_name), .cb = snl_attr_dup_string }, 829 { .type = NLA_BITSET_BIT_VALUE, .off = _OUT(bit_value), .cb = snl_attr_get_flag }, 830}; 831#undef _OUT 832SNL_DECLARE_ATTR_PARSER_EXT(_nla_bit_parser, sizeof(struct snl_attr_bit), _nla_p_bit, NULL); 833 834struct snl_attr_bitset { 835 uint32_t nla_bitset_size; 836 uint32_t *nla_bitset_mask; 837 uint32_t *nla_bitset_value; 838 struct snl_attr_bits bits; 839}; 840 841#define _OUT(_field) offsetof(struct snl_attr_bitset, _field) 842static const struct snl_attr_parser _nla_p_bitset[] = { 843 { .type = NLA_BITSET_SIZE, .off = _OUT(nla_bitset_size), .cb = snl_attr_get_uint32 }, 844 { .type = NLA_BITSET_BITS, .off = _OUT(bits), .cb = snl_attr_get_parray, .arg = &_nla_bit_parser }, 845 { .type = NLA_BITSET_VALUE, .off = _OUT(nla_bitset_mask), .cb = snl_attr_dup_nla }, 846 { .type = NLA_BITSET_MASK, .off = _OUT(nla_bitset_value), .cb = snl_attr_dup_nla }, 847}; 848 849static inline bool 850_cb_p_bitset(struct snl_state *ss __unused, void *_target) 851{ 852 struct snl_attr_bitset *target = (struct snl_attr_bitset *)_target; 853 854 uint32_t sz_bytes = _roundup2(target->nla_bitset_size, 32) / 8; 855 856 if (target->nla_bitset_mask != NULL) { 857 struct nlattr *nla = (struct nlattr *)target->nla_bitset_mask; 858 uint32_t data_len = NLA_DATA_LEN(nla); 859 860 if (data_len != sz_bytes || _roundup2(data_len, 4) != data_len) 861 return (false); 862 target->nla_bitset_mask = (uint32_t *)NLA_DATA(nla); 863 } 864 865 if (target->nla_bitset_value != NULL) { 866 struct nlattr *nla = (struct nlattr *)target->nla_bitset_value; 867 uint32_t data_len = NLA_DATA_LEN(nla); 868 869 if (data_len != sz_bytes || _roundup2(data_len, 4) != data_len) 870 return (false); 871 target->nla_bitset_value = (uint32_t *)NLA_DATA(nla); 872 } 873 return (true); 874} 875#undef _OUT 876SNL_DECLARE_ATTR_PARSER_EXT(_nla_bitset_parser, 877 sizeof(struct snl_attr_bitset), 878 _nla_p_bitset, _cb_p_bitset); 879 880/* 881 * Parses the compact bitset representation. 882 */ 883static inline bool 884snl_attr_get_bitset_c(struct snl_state *ss, struct nlattr *nla, 885 const void *arg __unused, void *_target) 886{ 887 const struct snl_hdr_parser *p = &_nla_bitset_parser; 888 struct snl_attr_bitset *target = (struct snl_attr_bitset *)_target; 889 890 /* Assumes target points to the beginning of the structure */ 891 if (!snl_parse_header(ss, NLA_DATA(nla), NLA_DATA_LEN(nla), p, _target)) 892 return (false); 893 if (target->nla_bitset_mask == NULL || target->nla_bitset_value == NULL) 894 return (false); 895 return (true); 896} 897 898static inline void 899snl_field_get_uint8(struct snl_state *ss __unused, void *src, void *target) 900{ 901 *((uint8_t *)target) = *((uint8_t *)src); 902} 903 904static inline void 905snl_field_get_uint16(struct snl_state *ss __unused, void *src, void *target) 906{ 907 *((uint16_t *)target) = *((uint16_t *)src); 908} 909 910static inline void 911snl_field_get_uint32(struct snl_state *ss __unused, void *src, void *target) 912{ 913 *((uint32_t *)target) = *((uint32_t *)src); 914} 915 916static inline void 917snl_field_get_ptr(struct snl_state *ss __unused, void *src, void *target) 918{ 919 *((void **)target) = src; 920} 921 922struct snl_errmsg_data { 923 struct nlmsghdr *orig_hdr; 924 int error; 925 uint32_t error_offs; 926 char *error_str; 927 struct nlattr *cookie; 928}; 929 930#define _IN(_field) offsetof(struct nlmsgerr, _field) 931#define _OUT(_field) offsetof(struct snl_errmsg_data, _field) 932static const struct snl_attr_parser nla_p_errmsg[] = { 933 { .type = NLMSGERR_ATTR_MSG, .off = _OUT(error_str), .cb = snl_attr_get_string }, 934 { .type = NLMSGERR_ATTR_OFFS, .off = _OUT(error_offs), .cb = snl_attr_get_uint32 }, 935 { .type = NLMSGERR_ATTR_COOKIE, .off = _OUT(cookie), .cb = snl_attr_get_nla }, 936}; 937 938static const struct snl_field_parser nlf_p_errmsg[] = { 939 { .off_in = _IN(error), .off_out = _OUT(error), .cb = snl_field_get_uint32 }, 940 { .off_in = _IN(msg), .off_out = _OUT(orig_hdr), .cb = snl_field_get_ptr }, 941}; 942#undef _IN 943#undef _OUT 944SNL_DECLARE_PARSER(snl_errmsg_parser, struct nlmsgerr, nlf_p_errmsg, nla_p_errmsg); 945 946#define _IN(_field) offsetof(struct nlmsgerr, _field) 947#define _OUT(_field) offsetof(struct snl_errmsg_data, _field) 948static const struct snl_field_parser nlf_p_donemsg[] = { 949 { .off_in = _IN(error), .off_out = _OUT(error), .cb = snl_field_get_uint32 }, 950}; 951#undef _IN 952#undef _OUT 953SNL_DECLARE_FIELD_PARSER(snl_donemsg_parser, struct nlmsgerr, nlf_p_donemsg); 954 955static inline bool 956snl_parse_errmsg(struct snl_state *ss, struct nlmsghdr *hdr, struct snl_errmsg_data *e) 957{ 958 if ((hdr->nlmsg_flags & NLM_F_CAPPED) != 0) 959 return (snl_parse_nlmsg(ss, hdr, &snl_errmsg_parser, e)); 960 961 const struct snl_hdr_parser *ps = &snl_errmsg_parser; 962 struct nlmsgerr *errmsg = (struct nlmsgerr *)(hdr + 1); 963 int hdrlen = sizeof(int) + NLMSG_ALIGN(errmsg->msg.nlmsg_len); 964 struct nlattr *attr_head = (struct nlattr *)(void *)((char *)errmsg + hdrlen); 965 int attr_len = hdr->nlmsg_len - sizeof(struct nlmsghdr) - hdrlen; 966 967 snl_parse_fields(ss, (struct nlmsghdr *)errmsg, hdrlen, ps->fp, ps->fp_size, e); 968 return (snl_parse_attrs_raw(ss, attr_head, attr_len, ps->np, ps->np_size, e)); 969} 970 971static inline bool 972snl_read_reply_code(struct snl_state *ss, uint32_t nlmsg_seq, struct snl_errmsg_data *e) 973{ 974 struct nlmsghdr *hdr = snl_read_reply(ss, nlmsg_seq); 975 976 if (hdr == NULL) { 977 e->error = EINVAL; 978 } else if (hdr->nlmsg_type == NLMSG_ERROR) { 979 if (!snl_parse_errmsg(ss, hdr, e)) 980 e->error = EINVAL; 981 return (e->error == 0); 982 } 983 984 return (false); 985} 986 987#define _OUT(_field) offsetof(struct snl_msg_info, _field) 988static const struct snl_attr_parser _nla_p_cinfo[] = { 989 { .type = NLMSGINFO_ATTR_PROCESS_ID, .off = _OUT(process_id), .cb = snl_attr_get_uint32 }, 990 { .type = NLMSGINFO_ATTR_PORT_ID, .off = _OUT(port_id), .cb = snl_attr_get_uint32 }, 991 { .type = NLMSGINFO_ATTR_SEQ_ID, .off = _OUT(seq_id), .cb = snl_attr_get_uint32 }, 992}; 993#undef _OUT 994SNL_DECLARE_ATTR_PARSER(snl_msg_info_parser, _nla_p_cinfo); 995 996static inline bool 997parse_cmsg(struct snl_state *ss, const struct msghdr *msg, struct snl_msg_info *attrs) 998{ 999 for (struct cmsghdr *cmsg = CMSG_FIRSTHDR(msg); cmsg != NULL; 1000 cmsg = CMSG_NXTHDR(msg, cmsg)) { 1001 if (cmsg->cmsg_level != SOL_NETLINK || cmsg->cmsg_type != NETLINK_MSG_INFO) 1002 continue; 1003 1004 void *data = CMSG_DATA(cmsg); 1005 int len = cmsg->cmsg_len - ((char *)data - (char *)cmsg); 1006 const struct snl_hdr_parser *ps = &snl_msg_info_parser; 1007 1008 return (snl_parse_attrs_raw(ss, (struct nlattr *)data, len, ps->np, ps->np_size, attrs)); 1009 } 1010 1011 return (false); 1012} 1013 1014/* 1015 * Assumes e is zeroed 1016 */ 1017static inline struct nlmsghdr * 1018snl_read_reply_multi(struct snl_state *ss, uint32_t nlmsg_seq, struct snl_errmsg_data *e) 1019{ 1020 struct nlmsghdr *hdr = snl_read_reply(ss, nlmsg_seq); 1021 1022 if (hdr == NULL) { 1023 e->error = EINVAL; 1024 } else if (hdr->nlmsg_type == NLMSG_ERROR) { 1025 if (!snl_parse_errmsg(ss, hdr, e)) 1026 e->error = EINVAL; 1027 } else if (hdr->nlmsg_type == NLMSG_DONE) { 1028 snl_parse_nlmsg(ss, hdr, &snl_donemsg_parser, e); 1029 } else 1030 return (hdr); 1031 1032 return (NULL); 1033} 1034 1035 1036/* writer logic */ 1037struct snl_writer { 1038 char *base; 1039 uint32_t offset; 1040 uint32_t size; 1041 struct nlmsghdr *hdr; 1042 struct snl_state *ss; 1043 bool error; 1044}; 1045 1046static inline void 1047snl_init_writer(struct snl_state *ss, struct snl_writer *nw) 1048{ 1049 nw->size = SNL_WRITER_BUFFER_SIZE; 1050 nw->base = (char *)snl_allocz(ss, nw->size); 1051 if (nw->base == NULL) { 1052 nw->error = true; 1053 nw->size = 0; 1054 } 1055 1056 nw->offset = 0; 1057 nw->hdr = NULL; 1058 nw->error = false; 1059 nw->ss = ss; 1060} 1061 1062static inline bool 1063snl_realloc_msg_buffer(struct snl_writer *nw, size_t sz) 1064{ 1065 uint32_t new_size = nw->size * 2; 1066 1067 while (new_size < nw->size + sz) 1068 new_size *= 2; 1069 1070 if (nw->error) 1071 return (false); 1072 1073 if (snl_allocz(nw->ss, new_size) == NULL) { 1074 nw->error = true; 1075 return (false); 1076 } 1077 nw->size = new_size; 1078 1079 void *new_base = nw->ss->lb->base; 1080 if (new_base != nw->base) { 1081 memcpy(new_base, nw->base, nw->offset); 1082 if (nw->hdr != NULL) { 1083 int hdr_off = (char *)(nw->hdr) - nw->base; 1084 1085 nw->hdr = (struct nlmsghdr *) 1086 (void *)((char *)new_base + hdr_off); 1087 } 1088 nw->base = (char *)new_base; 1089 } 1090 1091 return (true); 1092} 1093 1094static inline void * 1095snl_reserve_msg_data_raw(struct snl_writer *nw, size_t sz) 1096{ 1097 sz = NETLINK_ALIGN(sz); 1098 1099 if (__predict_false(nw->offset + sz > nw->size)) { 1100 if (!snl_realloc_msg_buffer(nw, sz)) 1101 return (NULL); 1102 } 1103 1104 void *data_ptr = &nw->base[nw->offset]; 1105 nw->offset += sz; 1106 1107 return (data_ptr); 1108} 1109#define snl_reserve_msg_object(_ns, _t) ((_t *)snl_reserve_msg_data_raw(_ns, sizeof(_t))) 1110#define snl_reserve_msg_data(_ns, _sz, _t) ((_t *)snl_reserve_msg_data_raw(_ns, _sz)) 1111 1112static inline void * 1113_snl_reserve_msg_attr(struct snl_writer *nw, uint16_t nla_type, uint16_t sz) 1114{ 1115 sz += sizeof(struct nlattr); 1116 1117 struct nlattr *nla = snl_reserve_msg_data(nw, sz, struct nlattr); 1118 if (__predict_false(nla == NULL)) 1119 return (NULL); 1120 nla->nla_type = nla_type; 1121 nla->nla_len = sz; 1122 1123 return ((void *)(nla + 1)); 1124} 1125#define snl_reserve_msg_attr(_ns, _at, _t) ((_t *)_snl_reserve_msg_attr(_ns, _at, sizeof(_t))) 1126 1127static inline bool 1128snl_add_msg_attr(struct snl_writer *nw, int attr_type, int attr_len, const void *data) 1129{ 1130 int required_len = NLA_ALIGN(attr_len + sizeof(struct nlattr)); 1131 1132 if (__predict_false(nw->offset + required_len > nw->size)) { 1133 if (!snl_realloc_msg_buffer(nw, required_len)) 1134 return (false); 1135 } 1136 1137 struct nlattr *nla = (struct nlattr *)(void *)(&nw->base[nw->offset]); 1138 1139 nla->nla_len = attr_len + sizeof(struct nlattr); 1140 nla->nla_type = attr_type; 1141 if (attr_len > 0) { 1142 if ((attr_len % 4) != 0) { 1143 /* clear padding bytes */ 1144 bzero((char *)nla + required_len - 4, 4); 1145 } 1146 memcpy((nla + 1), data, attr_len); 1147 } 1148 nw->offset += required_len; 1149 return (true); 1150} 1151 1152static inline bool 1153snl_add_msg_attr_raw(struct snl_writer *nw, const struct nlattr *nla_src) 1154{ 1155 int attr_len = nla_src->nla_len - sizeof(struct nlattr); 1156 1157 assert(attr_len >= 0); 1158 1159 return (snl_add_msg_attr(nw, nla_src->nla_type, attr_len, (const void *)(nla_src + 1))); 1160} 1161 1162static inline bool 1163snl_add_msg_attr_bool(struct snl_writer *nw, int attrtype, bool value) 1164{ 1165 return (snl_add_msg_attr(nw, attrtype, sizeof(bool), &value)); 1166} 1167 1168static inline bool 1169snl_add_msg_attr_u8(struct snl_writer *nw, int attrtype, uint8_t value) 1170{ 1171 return (snl_add_msg_attr(nw, attrtype, sizeof(uint8_t), &value)); 1172} 1173 1174static inline bool 1175snl_add_msg_attr_u16(struct snl_writer *nw, int attrtype, uint16_t value) 1176{ 1177 return (snl_add_msg_attr(nw, attrtype, sizeof(uint16_t), &value)); 1178} 1179 1180static inline bool 1181snl_add_msg_attr_u32(struct snl_writer *nw, int attrtype, uint32_t value) 1182{ 1183 return (snl_add_msg_attr(nw, attrtype, sizeof(uint32_t), &value)); 1184} 1185 1186static inline bool 1187snl_add_msg_attr_u64(struct snl_writer *nw, int attrtype, uint64_t value) 1188{ 1189 return (snl_add_msg_attr(nw, attrtype, sizeof(uint64_t), &value)); 1190} 1191 1192static inline bool 1193snl_add_msg_attr_s8(struct snl_writer *nw, int attrtype, int8_t value) 1194{ 1195 return (snl_add_msg_attr(nw, attrtype, sizeof(int8_t), &value)); 1196} 1197 1198static inline bool 1199snl_add_msg_attr_s16(struct snl_writer *nw, int attrtype, int16_t value) 1200{ 1201 return (snl_add_msg_attr(nw, attrtype, sizeof(int16_t), &value)); 1202} 1203 1204static inline bool 1205snl_add_msg_attr_s32(struct snl_writer *nw, int attrtype, int32_t value) 1206{ 1207 return (snl_add_msg_attr(nw, attrtype, sizeof(int32_t), &value)); 1208} 1209 1210static inline bool 1211snl_add_msg_attr_s64(struct snl_writer *nw, int attrtype, int64_t value) 1212{ 1213 return (snl_add_msg_attr(nw, attrtype, sizeof(int64_t), &value)); 1214} 1215 1216static inline bool 1217snl_add_msg_attr_flag(struct snl_writer *nw, int attrtype) 1218{ 1219 return (snl_add_msg_attr(nw, attrtype, 0, NULL)); 1220} 1221 1222static inline bool 1223snl_add_msg_attr_string(struct snl_writer *nw, int attrtype, const char *str) 1224{ 1225 return (snl_add_msg_attr(nw, attrtype, strlen(str) + 1, str)); 1226} 1227 1228 1229static inline int 1230snl_get_msg_offset(const struct snl_writer *nw) 1231{ 1232 return (nw->offset - ((char *)nw->hdr - nw->base)); 1233} 1234 1235static inline void * 1236_snl_restore_msg_offset(const struct snl_writer *nw, int off) 1237{ 1238 return ((void *)((char *)nw->hdr + off)); 1239} 1240#define snl_restore_msg_offset(_ns, _off, _t) ((_t *)_snl_restore_msg_offset(_ns, _off)) 1241 1242static inline int 1243snl_add_msg_attr_nested(struct snl_writer *nw, int attrtype) 1244{ 1245 int off = snl_get_msg_offset(nw); 1246 struct nlattr *nla = snl_reserve_msg_data(nw, sizeof(struct nlattr), struct nlattr); 1247 if (__predict_false(nla == NULL)) 1248 return (0); 1249 nla->nla_type = attrtype; 1250 return (off); 1251} 1252 1253static inline void 1254snl_end_attr_nested(const struct snl_writer *nw, int off) 1255{ 1256 if (!nw->error) { 1257 struct nlattr *nla = snl_restore_msg_offset(nw, off, struct nlattr); 1258 nla->nla_len = NETLINK_ALIGN(snl_get_msg_offset(nw) - off); 1259 } 1260} 1261 1262static inline struct nlmsghdr * 1263snl_create_msg_request(struct snl_writer *nw, int nlmsg_type) 1264{ 1265 assert(nw->hdr == NULL); 1266 1267 struct nlmsghdr *hdr = snl_reserve_msg_object(nw, struct nlmsghdr); 1268 hdr->nlmsg_type = nlmsg_type; 1269 hdr->nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK; 1270 nw->hdr = hdr; 1271 1272 return (hdr); 1273} 1274 1275static void 1276snl_abort_msg(struct snl_writer *nw) 1277{ 1278 if (nw->hdr != NULL) { 1279 int offset = (char *)(&nw->base[nw->offset]) - (char *)(nw->hdr); 1280 1281 nw->offset -= offset; 1282 nw->hdr = NULL; 1283 } 1284} 1285 1286static inline struct nlmsghdr * 1287snl_finalize_msg(struct snl_writer *nw) 1288{ 1289 if (nw->error) 1290 snl_abort_msg(nw); 1291 if (nw->hdr != NULL) { 1292 struct nlmsghdr *hdr = nw->hdr; 1293 1294 int offset = (char *)(&nw->base[nw->offset]) - (char *)(nw->hdr); 1295 hdr->nlmsg_len = offset; 1296 hdr->nlmsg_seq = snl_get_seq(nw->ss); 1297 nw->hdr = NULL; 1298 1299 return (hdr); 1300 } 1301 return (NULL); 1302} 1303 1304static inline bool 1305snl_send_msgs(struct snl_writer *nw) 1306{ 1307 int offset = nw->offset; 1308 1309 assert(nw->hdr == NULL); 1310 nw->offset = 0; 1311 1312 return (snl_send(nw->ss, nw->base, offset)); 1313} 1314 1315static const struct snl_hdr_parser *snl_all_core_parsers[] = { 1316 &snl_errmsg_parser, &snl_donemsg_parser, 1317 &_nla_bit_parser, &_nla_bitset_parser, 1318}; 1319 1320#endif 1321