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