1 // SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause 2 #include <errno.h> 3 #include <poll.h> 4 #include <string.h> 5 #include <stdlib.h> 6 #include <linux/types.h> 7 8 #include <libmnl/libmnl.h> 9 #include <linux/genetlink.h> 10 11 #include "ynl.h" 12 13 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof(*arr)) 14 15 #define __yerr_msg(yse, _msg...) \ 16 ({ \ 17 struct ynl_error *_yse = (yse); \ 18 \ 19 if (_yse) { \ 20 snprintf(_yse->msg, sizeof(_yse->msg) - 1, _msg); \ 21 _yse->msg[sizeof(_yse->msg) - 1] = 0; \ 22 } \ 23 }) 24 25 #define __yerr_code(yse, _code...) \ 26 ({ \ 27 struct ynl_error *_yse = (yse); \ 28 \ 29 if (_yse) { \ 30 _yse->code = _code; \ 31 } \ 32 }) 33 34 #define __yerr(yse, _code, _msg...) \ 35 ({ \ 36 __yerr_msg(yse, _msg); \ 37 __yerr_code(yse, _code); \ 38 }) 39 40 #define __perr(yse, _msg) __yerr(yse, errno, _msg) 41 42 #define yerr_msg(_ys, _msg...) __yerr_msg(&(_ys)->err, _msg) 43 #define yerr(_ys, _code, _msg...) __yerr(&(_ys)->err, _code, _msg) 44 #define perr(_ys, _msg) __yerr(&(_ys)->err, errno, _msg) 45 46 /* -- Netlink boiler plate */ 47 static int 48 ynl_err_walk_report_one(struct ynl_policy_nest *policy, unsigned int type, 49 char *str, int str_sz, int *n) 50 { 51 if (!policy) { 52 if (*n < str_sz) 53 *n += snprintf(str, str_sz, "!policy"); 54 return 1; 55 } 56 57 if (type > policy->max_attr) { 58 if (*n < str_sz) 59 *n += snprintf(str, str_sz, "!oob"); 60 return 1; 61 } 62 63 if (!policy->table[type].name) { 64 if (*n < str_sz) 65 *n += snprintf(str, str_sz, "!name"); 66 return 1; 67 } 68 69 if (*n < str_sz) 70 *n += snprintf(str, str_sz - *n, 71 ".%s", policy->table[type].name); 72 return 0; 73 } 74 75 static int 76 ynl_err_walk(struct ynl_sock *ys, void *start, void *end, unsigned int off, 77 struct ynl_policy_nest *policy, char *str, int str_sz, 78 struct ynl_policy_nest **nest_pol) 79 { 80 unsigned int astart_off, aend_off; 81 const struct nlattr *attr; 82 unsigned int data_len; 83 unsigned int type; 84 bool found = false; 85 int n = 0; 86 87 if (!policy) { 88 if (n < str_sz) 89 n += snprintf(str, str_sz, "!policy"); 90 return n; 91 } 92 93 data_len = end - start; 94 95 mnl_attr_for_each_payload(start, data_len) { 96 astart_off = (char *)attr - (char *)start; 97 aend_off = astart_off + mnl_attr_get_payload_len(attr); 98 if (aend_off <= off) 99 continue; 100 101 found = true; 102 break; 103 } 104 if (!found) 105 return 0; 106 107 off -= astart_off; 108 109 type = mnl_attr_get_type(attr); 110 111 if (ynl_err_walk_report_one(policy, type, str, str_sz, &n)) 112 return n; 113 114 if (!off) { 115 if (nest_pol) 116 *nest_pol = policy->table[type].nest; 117 return n; 118 } 119 120 if (!policy->table[type].nest) { 121 if (n < str_sz) 122 n += snprintf(str, str_sz, "!nest"); 123 return n; 124 } 125 126 off -= sizeof(struct nlattr); 127 start = mnl_attr_get_payload(attr); 128 end = start + mnl_attr_get_payload_len(attr); 129 130 return n + ynl_err_walk(ys, start, end, off, policy->table[type].nest, 131 &str[n], str_sz - n, nest_pol); 132 } 133 134 #define NLMSGERR_ATTR_MISS_TYPE (NLMSGERR_ATTR_POLICY + 1) 135 #define NLMSGERR_ATTR_MISS_NEST (NLMSGERR_ATTR_POLICY + 2) 136 #define NLMSGERR_ATTR_MAX (NLMSGERR_ATTR_MAX + 2) 137 138 static int 139 ynl_ext_ack_check(struct ynl_sock *ys, const struct nlmsghdr *nlh, 140 unsigned int hlen) 141 { 142 const struct nlattr *tb[NLMSGERR_ATTR_MAX + 1] = {}; 143 char miss_attr[sizeof(ys->err.msg)]; 144 char bad_attr[sizeof(ys->err.msg)]; 145 const struct nlattr *attr; 146 const char *str = NULL; 147 148 if (!(nlh->nlmsg_flags & NLM_F_ACK_TLVS)) { 149 yerr_msg(ys, "%s", strerror(ys->err.code)); 150 return MNL_CB_OK; 151 } 152 153 mnl_attr_for_each(attr, nlh, hlen) { 154 unsigned int len, type; 155 156 len = mnl_attr_get_payload_len(attr); 157 type = mnl_attr_get_type(attr); 158 159 if (type > NLMSGERR_ATTR_MAX) 160 continue; 161 162 tb[type] = attr; 163 164 switch (type) { 165 case NLMSGERR_ATTR_OFFS: 166 case NLMSGERR_ATTR_MISS_TYPE: 167 case NLMSGERR_ATTR_MISS_NEST: 168 if (len != sizeof(__u32)) 169 return MNL_CB_ERROR; 170 break; 171 case NLMSGERR_ATTR_MSG: 172 str = mnl_attr_get_payload(attr); 173 if (str[len - 1]) 174 return MNL_CB_ERROR; 175 break; 176 default: 177 break; 178 } 179 } 180 181 bad_attr[0] = '\0'; 182 miss_attr[0] = '\0'; 183 184 if (tb[NLMSGERR_ATTR_OFFS]) { 185 unsigned int n, off; 186 void *start, *end; 187 188 ys->err.attr_offs = mnl_attr_get_u32(tb[NLMSGERR_ATTR_OFFS]); 189 190 n = snprintf(bad_attr, sizeof(bad_attr), "%sbad attribute: ", 191 str ? " (" : ""); 192 193 start = mnl_nlmsg_get_payload_offset(ys->nlh, 194 ys->family->hdr_len); 195 end = mnl_nlmsg_get_payload_tail(ys->nlh); 196 197 off = ys->err.attr_offs; 198 off -= sizeof(struct nlmsghdr); 199 off -= ys->family->hdr_len; 200 201 n += ynl_err_walk(ys, start, end, off, ys->req_policy, 202 &bad_attr[n], sizeof(bad_attr) - n, NULL); 203 204 if (n >= sizeof(bad_attr)) 205 n = sizeof(bad_attr) - 1; 206 bad_attr[n] = '\0'; 207 } 208 if (tb[NLMSGERR_ATTR_MISS_TYPE]) { 209 struct ynl_policy_nest *nest_pol = NULL; 210 unsigned int n, off, type; 211 void *start, *end; 212 int n2; 213 214 type = mnl_attr_get_u32(tb[NLMSGERR_ATTR_MISS_TYPE]); 215 216 n = snprintf(miss_attr, sizeof(miss_attr), "%smissing attribute: ", 217 bad_attr[0] ? ", " : (str ? " (" : "")); 218 219 start = mnl_nlmsg_get_payload_offset(ys->nlh, 220 ys->family->hdr_len); 221 end = mnl_nlmsg_get_payload_tail(ys->nlh); 222 223 nest_pol = ys->req_policy; 224 if (tb[NLMSGERR_ATTR_MISS_NEST]) { 225 off = mnl_attr_get_u32(tb[NLMSGERR_ATTR_MISS_NEST]); 226 off -= sizeof(struct nlmsghdr); 227 off -= ys->family->hdr_len; 228 229 n += ynl_err_walk(ys, start, end, off, ys->req_policy, 230 &miss_attr[n], sizeof(miss_attr) - n, 231 &nest_pol); 232 } 233 234 n2 = 0; 235 ynl_err_walk_report_one(nest_pol, type, &miss_attr[n], 236 sizeof(miss_attr) - n, &n2); 237 n += n2; 238 239 if (n >= sizeof(miss_attr)) 240 n = sizeof(miss_attr) - 1; 241 miss_attr[n] = '\0'; 242 } 243 244 /* Implicitly depend on ys->err.code already set */ 245 if (str) 246 yerr_msg(ys, "Kernel %s: '%s'%s%s%s", 247 ys->err.code ? "error" : "warning", 248 str, bad_attr, miss_attr, 249 bad_attr[0] || miss_attr[0] ? ")" : ""); 250 else if (bad_attr[0] || miss_attr[0]) 251 yerr_msg(ys, "Kernel %s: %s%s", 252 ys->err.code ? "error" : "warning", 253 bad_attr, miss_attr); 254 else 255 yerr_msg(ys, "%s", strerror(ys->err.code)); 256 257 return MNL_CB_OK; 258 } 259 260 static int ynl_cb_error(const struct nlmsghdr *nlh, void *data) 261 { 262 const struct nlmsgerr *err = mnl_nlmsg_get_payload(nlh); 263 struct ynl_parse_arg *yarg = data; 264 unsigned int hlen; 265 int code; 266 267 code = err->error >= 0 ? err->error : -err->error; 268 yarg->ys->err.code = code; 269 errno = code; 270 271 hlen = sizeof(*err); 272 if (!(nlh->nlmsg_flags & NLM_F_CAPPED)) 273 hlen += mnl_nlmsg_get_payload_len(&err->msg); 274 275 ynl_ext_ack_check(yarg->ys, nlh, hlen); 276 277 return code ? MNL_CB_ERROR : MNL_CB_STOP; 278 } 279 280 static int ynl_cb_done(const struct nlmsghdr *nlh, void *data) 281 { 282 struct ynl_parse_arg *yarg = data; 283 int err; 284 285 err = *(int *)NLMSG_DATA(nlh); 286 if (err < 0) { 287 yarg->ys->err.code = -err; 288 errno = -err; 289 290 ynl_ext_ack_check(yarg->ys, nlh, sizeof(int)); 291 292 return MNL_CB_ERROR; 293 } 294 return MNL_CB_STOP; 295 } 296 297 static int ynl_cb_noop(const struct nlmsghdr *nlh, void *data) 298 { 299 return MNL_CB_OK; 300 } 301 302 mnl_cb_t ynl_cb_array[NLMSG_MIN_TYPE] = { 303 [NLMSG_NOOP] = ynl_cb_noop, 304 [NLMSG_ERROR] = ynl_cb_error, 305 [NLMSG_DONE] = ynl_cb_done, 306 [NLMSG_OVERRUN] = ynl_cb_noop, 307 }; 308 309 /* Attribute validation */ 310 311 int ynl_attr_validate(struct ynl_parse_arg *yarg, const struct nlattr *attr) 312 { 313 struct ynl_policy_attr *policy; 314 unsigned int type, len; 315 unsigned char *data; 316 317 data = mnl_attr_get_payload(attr); 318 len = mnl_attr_get_payload_len(attr); 319 type = mnl_attr_get_type(attr); 320 if (type > yarg->rsp_policy->max_attr) { 321 yerr(yarg->ys, YNL_ERROR_INTERNAL, 322 "Internal error, validating unknown attribute"); 323 return -1; 324 } 325 326 policy = &yarg->rsp_policy->table[type]; 327 328 switch (policy->type) { 329 case YNL_PT_REJECT: 330 yerr(yarg->ys, YNL_ERROR_ATTR_INVALID, 331 "Rejected attribute (%s)", policy->name); 332 return -1; 333 case YNL_PT_IGNORE: 334 break; 335 case YNL_PT_U8: 336 if (len == sizeof(__u8)) 337 break; 338 yerr(yarg->ys, YNL_ERROR_ATTR_INVALID, 339 "Invalid attribute (u8 %s)", policy->name); 340 return -1; 341 case YNL_PT_U16: 342 if (len == sizeof(__u16)) 343 break; 344 yerr(yarg->ys, YNL_ERROR_ATTR_INVALID, 345 "Invalid attribute (u16 %s)", policy->name); 346 return -1; 347 case YNL_PT_U32: 348 if (len == sizeof(__u32)) 349 break; 350 yerr(yarg->ys, YNL_ERROR_ATTR_INVALID, 351 "Invalid attribute (u32 %s)", policy->name); 352 return -1; 353 case YNL_PT_U64: 354 if (len == sizeof(__u64)) 355 break; 356 yerr(yarg->ys, YNL_ERROR_ATTR_INVALID, 357 "Invalid attribute (u64 %s)", policy->name); 358 return -1; 359 case YNL_PT_UINT: 360 if (len == sizeof(__u32) || len == sizeof(__u64)) 361 break; 362 yerr(yarg->ys, YNL_ERROR_ATTR_INVALID, 363 "Invalid attribute (uint %s)", policy->name); 364 return -1; 365 case YNL_PT_FLAG: 366 /* Let flags grow into real attrs, why not.. */ 367 break; 368 case YNL_PT_NEST: 369 if (!len || len >= sizeof(*attr)) 370 break; 371 yerr(yarg->ys, YNL_ERROR_ATTR_INVALID, 372 "Invalid attribute (nest %s)", policy->name); 373 return -1; 374 case YNL_PT_BINARY: 375 if (!policy->len || len == policy->len) 376 break; 377 yerr(yarg->ys, YNL_ERROR_ATTR_INVALID, 378 "Invalid attribute (binary %s)", policy->name); 379 return -1; 380 case YNL_PT_NUL_STR: 381 if ((!policy->len || len <= policy->len) && !data[len - 1]) 382 break; 383 yerr(yarg->ys, YNL_ERROR_ATTR_INVALID, 384 "Invalid attribute (string %s)", policy->name); 385 return -1; 386 case YNL_PT_BITFIELD32: 387 if (len == sizeof(struct nla_bitfield32)) 388 break; 389 yerr(yarg->ys, YNL_ERROR_ATTR_INVALID, 390 "Invalid attribute (bitfield32 %s)", policy->name); 391 return -1; 392 default: 393 yerr(yarg->ys, YNL_ERROR_ATTR_INVALID, 394 "Invalid attribute (unknown %s)", policy->name); 395 return -1; 396 } 397 398 return 0; 399 } 400 401 /* Generic code */ 402 403 static void ynl_err_reset(struct ynl_sock *ys) 404 { 405 ys->err.code = 0; 406 ys->err.attr_offs = 0; 407 ys->err.msg[0] = 0; 408 } 409 410 struct nlmsghdr *ynl_msg_start(struct ynl_sock *ys, __u32 id, __u16 flags) 411 { 412 struct nlmsghdr *nlh; 413 414 ynl_err_reset(ys); 415 416 nlh = ys->nlh = mnl_nlmsg_put_header(ys->tx_buf); 417 nlh->nlmsg_type = id; 418 nlh->nlmsg_flags = flags; 419 nlh->nlmsg_seq = ++ys->seq; 420 421 return nlh; 422 } 423 424 struct nlmsghdr * 425 ynl_gemsg_start(struct ynl_sock *ys, __u32 id, __u16 flags, 426 __u8 cmd, __u8 version) 427 { 428 struct genlmsghdr gehdr; 429 struct nlmsghdr *nlh; 430 void *data; 431 432 nlh = ynl_msg_start(ys, id, flags); 433 434 memset(&gehdr, 0, sizeof(gehdr)); 435 gehdr.cmd = cmd; 436 gehdr.version = version; 437 438 data = mnl_nlmsg_put_extra_header(nlh, sizeof(gehdr)); 439 memcpy(data, &gehdr, sizeof(gehdr)); 440 441 return nlh; 442 } 443 444 void ynl_msg_start_req(struct ynl_sock *ys, __u32 id) 445 { 446 ynl_msg_start(ys, id, NLM_F_REQUEST | NLM_F_ACK); 447 } 448 449 void ynl_msg_start_dump(struct ynl_sock *ys, __u32 id) 450 { 451 ynl_msg_start(ys, id, NLM_F_REQUEST | NLM_F_ACK | NLM_F_DUMP); 452 } 453 454 struct nlmsghdr * 455 ynl_gemsg_start_req(struct ynl_sock *ys, __u32 id, __u8 cmd, __u8 version) 456 { 457 return ynl_gemsg_start(ys, id, NLM_F_REQUEST | NLM_F_ACK, cmd, version); 458 } 459 460 struct nlmsghdr * 461 ynl_gemsg_start_dump(struct ynl_sock *ys, __u32 id, __u8 cmd, __u8 version) 462 { 463 return ynl_gemsg_start(ys, id, NLM_F_REQUEST | NLM_F_ACK | NLM_F_DUMP, 464 cmd, version); 465 } 466 467 int ynl_recv_ack(struct ynl_sock *ys, int ret) 468 { 469 if (!ret) { 470 yerr(ys, YNL_ERROR_EXPECT_ACK, 471 "Expecting an ACK but nothing received"); 472 return -1; 473 } 474 475 ret = mnl_socket_recvfrom(ys->sock, ys->rx_buf, MNL_SOCKET_BUFFER_SIZE); 476 if (ret < 0) { 477 perr(ys, "Socket receive failed"); 478 return ret; 479 } 480 return mnl_cb_run(ys->rx_buf, ret, ys->seq, ys->portid, 481 ynl_cb_null, ys); 482 } 483 484 int ynl_cb_null(const struct nlmsghdr *nlh, void *data) 485 { 486 struct ynl_parse_arg *yarg = data; 487 488 yerr(yarg->ys, YNL_ERROR_UNEXPECT_MSG, 489 "Received a message when none were expected"); 490 491 return MNL_CB_ERROR; 492 } 493 494 /* Init/fini and genetlink boiler plate */ 495 static int 496 ynl_get_family_info_mcast(struct ynl_sock *ys, const struct nlattr *mcasts) 497 { 498 const struct nlattr *entry, *attr; 499 unsigned int i; 500 501 mnl_attr_for_each_nested(attr, mcasts) 502 ys->n_mcast_groups++; 503 504 if (!ys->n_mcast_groups) 505 return 0; 506 507 ys->mcast_groups = calloc(ys->n_mcast_groups, 508 sizeof(*ys->mcast_groups)); 509 if (!ys->mcast_groups) 510 return MNL_CB_ERROR; 511 512 i = 0; 513 mnl_attr_for_each_nested(entry, mcasts) { 514 mnl_attr_for_each_nested(attr, entry) { 515 if (mnl_attr_get_type(attr) == CTRL_ATTR_MCAST_GRP_ID) 516 ys->mcast_groups[i].id = mnl_attr_get_u32(attr); 517 if (mnl_attr_get_type(attr) == CTRL_ATTR_MCAST_GRP_NAME) { 518 strncpy(ys->mcast_groups[i].name, 519 mnl_attr_get_str(attr), 520 GENL_NAMSIZ - 1); 521 ys->mcast_groups[i].name[GENL_NAMSIZ - 1] = 0; 522 } 523 } 524 } 525 526 return 0; 527 } 528 529 static int ynl_get_family_info_cb(const struct nlmsghdr *nlh, void *data) 530 { 531 struct ynl_parse_arg *yarg = data; 532 struct ynl_sock *ys = yarg->ys; 533 const struct nlattr *attr; 534 bool found_id = true; 535 536 mnl_attr_for_each(attr, nlh, sizeof(struct genlmsghdr)) { 537 if (mnl_attr_get_type(attr) == CTRL_ATTR_MCAST_GROUPS) 538 if (ynl_get_family_info_mcast(ys, attr)) 539 return MNL_CB_ERROR; 540 541 if (mnl_attr_get_type(attr) != CTRL_ATTR_FAMILY_ID) 542 continue; 543 544 if (mnl_attr_get_payload_len(attr) != sizeof(__u16)) { 545 yerr(ys, YNL_ERROR_ATTR_INVALID, "Invalid family ID"); 546 return MNL_CB_ERROR; 547 } 548 549 ys->family_id = mnl_attr_get_u16(attr); 550 found_id = true; 551 } 552 553 if (!found_id) { 554 yerr(ys, YNL_ERROR_ATTR_MISSING, "Family ID missing"); 555 return MNL_CB_ERROR; 556 } 557 return MNL_CB_OK; 558 } 559 560 static int ynl_sock_read_family(struct ynl_sock *ys, const char *family_name) 561 { 562 struct ynl_parse_arg yarg = { .ys = ys, }; 563 struct nlmsghdr *nlh; 564 int err; 565 566 nlh = ynl_gemsg_start_req(ys, GENL_ID_CTRL, CTRL_CMD_GETFAMILY, 1); 567 mnl_attr_put_strz(nlh, CTRL_ATTR_FAMILY_NAME, family_name); 568 569 err = mnl_socket_sendto(ys->sock, nlh, nlh->nlmsg_len); 570 if (err < 0) { 571 perr(ys, "failed to request socket family info"); 572 return err; 573 } 574 575 err = mnl_socket_recvfrom(ys->sock, ys->rx_buf, MNL_SOCKET_BUFFER_SIZE); 576 if (err <= 0) { 577 perr(ys, "failed to receive the socket family info"); 578 return err; 579 } 580 err = mnl_cb_run2(ys->rx_buf, err, ys->seq, ys->portid, 581 ynl_get_family_info_cb, &yarg, 582 ynl_cb_array, ARRAY_SIZE(ynl_cb_array)); 583 if (err < 0) { 584 free(ys->mcast_groups); 585 perr(ys, "failed to receive the socket family info - no such family?"); 586 return err; 587 } 588 589 return ynl_recv_ack(ys, err); 590 } 591 592 struct ynl_sock * 593 ynl_sock_create(const struct ynl_family *yf, struct ynl_error *yse) 594 { 595 struct ynl_sock *ys; 596 int one = 1; 597 598 ys = malloc(sizeof(*ys) + 2 * MNL_SOCKET_BUFFER_SIZE); 599 if (!ys) 600 return NULL; 601 memset(ys, 0, sizeof(*ys)); 602 603 ys->family = yf; 604 ys->tx_buf = &ys->raw_buf[0]; 605 ys->rx_buf = &ys->raw_buf[MNL_SOCKET_BUFFER_SIZE]; 606 ys->ntf_last_next = &ys->ntf_first; 607 608 ys->sock = mnl_socket_open(NETLINK_GENERIC); 609 if (!ys->sock) { 610 __perr(yse, "failed to create a netlink socket"); 611 goto err_free_sock; 612 } 613 614 if (mnl_socket_setsockopt(ys->sock, NETLINK_CAP_ACK, 615 &one, sizeof(one))) { 616 __perr(yse, "failed to enable netlink ACK"); 617 goto err_close_sock; 618 } 619 if (mnl_socket_setsockopt(ys->sock, NETLINK_EXT_ACK, 620 &one, sizeof(one))) { 621 __perr(yse, "failed to enable netlink ext ACK"); 622 goto err_close_sock; 623 } 624 625 ys->seq = random(); 626 ys->portid = mnl_socket_get_portid(ys->sock); 627 628 if (ynl_sock_read_family(ys, yf->name)) { 629 if (yse) 630 memcpy(yse, &ys->err, sizeof(*yse)); 631 goto err_close_sock; 632 } 633 634 return ys; 635 636 err_close_sock: 637 mnl_socket_close(ys->sock); 638 err_free_sock: 639 free(ys); 640 return NULL; 641 } 642 643 void ynl_sock_destroy(struct ynl_sock *ys) 644 { 645 struct ynl_ntf_base_type *ntf; 646 647 mnl_socket_close(ys->sock); 648 while ((ntf = ynl_ntf_dequeue(ys))) 649 ynl_ntf_free(ntf); 650 free(ys->mcast_groups); 651 free(ys); 652 } 653 654 /* YNL multicast handling */ 655 656 void ynl_ntf_free(struct ynl_ntf_base_type *ntf) 657 { 658 ntf->free(ntf); 659 } 660 661 int ynl_subscribe(struct ynl_sock *ys, const char *grp_name) 662 { 663 unsigned int i; 664 int err; 665 666 for (i = 0; i < ys->n_mcast_groups; i++) 667 if (!strcmp(ys->mcast_groups[i].name, grp_name)) 668 break; 669 if (i == ys->n_mcast_groups) { 670 yerr(ys, ENOENT, "Multicast group '%s' not found", grp_name); 671 return -1; 672 } 673 674 err = mnl_socket_setsockopt(ys->sock, NETLINK_ADD_MEMBERSHIP, 675 &ys->mcast_groups[i].id, 676 sizeof(ys->mcast_groups[i].id)); 677 if (err < 0) { 678 perr(ys, "Subscribing to multicast group failed"); 679 return -1; 680 } 681 682 return 0; 683 } 684 685 int ynl_socket_get_fd(struct ynl_sock *ys) 686 { 687 return mnl_socket_get_fd(ys->sock); 688 } 689 690 struct ynl_ntf_base_type *ynl_ntf_dequeue(struct ynl_sock *ys) 691 { 692 struct ynl_ntf_base_type *ntf; 693 694 if (!ynl_has_ntf(ys)) 695 return NULL; 696 697 ntf = ys->ntf_first; 698 ys->ntf_first = ntf->next; 699 if (ys->ntf_last_next == &ntf->next) 700 ys->ntf_last_next = &ys->ntf_first; 701 702 return ntf; 703 } 704 705 static int ynl_ntf_parse(struct ynl_sock *ys, const struct nlmsghdr *nlh) 706 { 707 struct ynl_parse_arg yarg = { .ys = ys, }; 708 const struct ynl_ntf_info *info; 709 struct ynl_ntf_base_type *rsp; 710 struct genlmsghdr *gehdr; 711 int ret; 712 713 gehdr = mnl_nlmsg_get_payload(nlh); 714 if (gehdr->cmd >= ys->family->ntf_info_size) 715 return MNL_CB_ERROR; 716 info = &ys->family->ntf_info[gehdr->cmd]; 717 if (!info->cb) 718 return MNL_CB_ERROR; 719 720 rsp = calloc(1, info->alloc_sz); 721 rsp->free = info->free; 722 yarg.data = rsp->data; 723 yarg.rsp_policy = info->policy; 724 725 ret = info->cb(nlh, &yarg); 726 if (ret <= MNL_CB_STOP) 727 goto err_free; 728 729 rsp->family = nlh->nlmsg_type; 730 rsp->cmd = gehdr->cmd; 731 732 *ys->ntf_last_next = rsp; 733 ys->ntf_last_next = &rsp->next; 734 735 return MNL_CB_OK; 736 737 err_free: 738 info->free(rsp); 739 return MNL_CB_ERROR; 740 } 741 742 static int ynl_ntf_trampoline(const struct nlmsghdr *nlh, void *data) 743 { 744 return ynl_ntf_parse((struct ynl_sock *)data, nlh); 745 } 746 747 int ynl_ntf_check(struct ynl_sock *ys) 748 { 749 ssize_t len; 750 int err; 751 752 do { 753 /* libmnl doesn't let us pass flags to the recv to make 754 * it non-blocking so we need to poll() or peek() :| 755 */ 756 struct pollfd pfd = { }; 757 758 pfd.fd = mnl_socket_get_fd(ys->sock); 759 pfd.events = POLLIN; 760 err = poll(&pfd, 1, 1); 761 if (err < 1) 762 return err; 763 764 len = mnl_socket_recvfrom(ys->sock, ys->rx_buf, 765 MNL_SOCKET_BUFFER_SIZE); 766 if (len < 0) 767 return len; 768 769 err = mnl_cb_run2(ys->rx_buf, len, ys->seq, ys->portid, 770 ynl_ntf_trampoline, ys, 771 ynl_cb_array, NLMSG_MIN_TYPE); 772 if (err < 0) 773 return err; 774 } while (err > 0); 775 776 return 0; 777 } 778 779 /* YNL specific helpers used by the auto-generated code */ 780 781 struct ynl_dump_list_type *YNL_LIST_END = (void *)(0xb4d123); 782 783 void ynl_error_unknown_notification(struct ynl_sock *ys, __u8 cmd) 784 { 785 yerr(ys, YNL_ERROR_UNKNOWN_NTF, 786 "Unknown notification message type '%d'", cmd); 787 } 788 789 int ynl_error_parse(struct ynl_parse_arg *yarg, const char *msg) 790 { 791 yerr(yarg->ys, YNL_ERROR_INV_RESP, "Error parsing response: %s", msg); 792 return MNL_CB_ERROR; 793 } 794 795 static int 796 ynl_check_alien(struct ynl_sock *ys, const struct nlmsghdr *nlh, __u32 rsp_cmd) 797 { 798 struct genlmsghdr *gehdr; 799 800 if (mnl_nlmsg_get_payload_len(nlh) < sizeof(*gehdr)) { 801 yerr(ys, YNL_ERROR_INV_RESP, 802 "Kernel responded with truncated message"); 803 return -1; 804 } 805 806 gehdr = mnl_nlmsg_get_payload(nlh); 807 if (gehdr->cmd != rsp_cmd) 808 return ynl_ntf_parse(ys, nlh); 809 810 return 0; 811 } 812 813 static int ynl_req_trampoline(const struct nlmsghdr *nlh, void *data) 814 { 815 struct ynl_req_state *yrs = data; 816 int ret; 817 818 ret = ynl_check_alien(yrs->yarg.ys, nlh, yrs->rsp_cmd); 819 if (ret) 820 return ret < 0 ? MNL_CB_ERROR : MNL_CB_OK; 821 822 return yrs->cb(nlh, &yrs->yarg); 823 } 824 825 int ynl_exec(struct ynl_sock *ys, struct nlmsghdr *req_nlh, 826 struct ynl_req_state *yrs) 827 { 828 ssize_t len; 829 int err; 830 831 err = mnl_socket_sendto(ys->sock, req_nlh, req_nlh->nlmsg_len); 832 if (err < 0) 833 return err; 834 835 do { 836 len = mnl_socket_recvfrom(ys->sock, ys->rx_buf, 837 MNL_SOCKET_BUFFER_SIZE); 838 if (len < 0) 839 return len; 840 841 err = mnl_cb_run2(ys->rx_buf, len, ys->seq, ys->portid, 842 ynl_req_trampoline, yrs, 843 ynl_cb_array, NLMSG_MIN_TYPE); 844 if (err < 0) 845 return err; 846 } while (err > 0); 847 848 return 0; 849 } 850 851 static int ynl_dump_trampoline(const struct nlmsghdr *nlh, void *data) 852 { 853 struct ynl_dump_state *ds = data; 854 struct ynl_dump_list_type *obj; 855 struct ynl_parse_arg yarg = {}; 856 int ret; 857 858 ret = ynl_check_alien(ds->ys, nlh, ds->rsp_cmd); 859 if (ret) 860 return ret < 0 ? MNL_CB_ERROR : MNL_CB_OK; 861 862 obj = calloc(1, ds->alloc_sz); 863 if (!obj) 864 return MNL_CB_ERROR; 865 866 if (!ds->first) 867 ds->first = obj; 868 if (ds->last) 869 ds->last->next = obj; 870 ds->last = obj; 871 872 yarg.ys = ds->ys; 873 yarg.rsp_policy = ds->rsp_policy; 874 yarg.data = &obj->data; 875 876 return ds->cb(nlh, &yarg); 877 } 878 879 static void *ynl_dump_end(struct ynl_dump_state *ds) 880 { 881 if (!ds->first) 882 return YNL_LIST_END; 883 884 ds->last->next = YNL_LIST_END; 885 return ds->first; 886 } 887 888 int ynl_exec_dump(struct ynl_sock *ys, struct nlmsghdr *req_nlh, 889 struct ynl_dump_state *yds) 890 { 891 ssize_t len; 892 int err; 893 894 err = mnl_socket_sendto(ys->sock, req_nlh, req_nlh->nlmsg_len); 895 if (err < 0) 896 return err; 897 898 do { 899 len = mnl_socket_recvfrom(ys->sock, ys->rx_buf, 900 MNL_SOCKET_BUFFER_SIZE); 901 if (len < 0) 902 goto err_close_list; 903 904 err = mnl_cb_run2(ys->rx_buf, len, ys->seq, ys->portid, 905 ynl_dump_trampoline, yds, 906 ynl_cb_array, NLMSG_MIN_TYPE); 907 if (err < 0) 908 goto err_close_list; 909 } while (err > 0); 910 911 yds->first = ynl_dump_end(yds); 912 return 0; 913 914 err_close_list: 915 yds->first = ynl_dump_end(yds); 916 return -1; 917 } 918