1 // SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) 2 /* Copyright (c) 2018 Facebook */ 3 4 #include <stdlib.h> 5 #include <memory.h> 6 #include <unistd.h> 7 #include <arpa/inet.h> 8 #include <linux/bpf.h> 9 #include <linux/if_ether.h> 10 #include <linux/pkt_cls.h> 11 #include <linux/rtnetlink.h> 12 #include <sys/socket.h> 13 #include <errno.h> 14 #include <time.h> 15 16 #include "bpf.h" 17 #include "libbpf.h" 18 #include "libbpf_internal.h" 19 #include "nlattr.h" 20 21 #ifndef SOL_NETLINK 22 #define SOL_NETLINK 270 23 #endif 24 25 typedef int (*libbpf_dump_nlmsg_t)(void *cookie, void *msg, struct nlattr **tb); 26 27 typedef int (*__dump_nlmsg_t)(struct nlmsghdr *nlmsg, libbpf_dump_nlmsg_t, 28 void *cookie); 29 30 struct xdp_id_md { 31 int ifindex; 32 __u32 flags; 33 struct xdp_link_info info; 34 }; 35 36 static int libbpf_netlink_open(__u32 *nl_pid) 37 { 38 struct sockaddr_nl sa; 39 socklen_t addrlen; 40 int one = 1, ret; 41 int sock; 42 43 memset(&sa, 0, sizeof(sa)); 44 sa.nl_family = AF_NETLINK; 45 46 sock = socket(AF_NETLINK, SOCK_RAW | SOCK_CLOEXEC, NETLINK_ROUTE); 47 if (sock < 0) 48 return -errno; 49 50 if (setsockopt(sock, SOL_NETLINK, NETLINK_EXT_ACK, 51 &one, sizeof(one)) < 0) { 52 pr_warn("Netlink error reporting not supported\n"); 53 } 54 55 if (bind(sock, (struct sockaddr *)&sa, sizeof(sa)) < 0) { 56 ret = -errno; 57 goto cleanup; 58 } 59 60 addrlen = sizeof(sa); 61 if (getsockname(sock, (struct sockaddr *)&sa, &addrlen) < 0) { 62 ret = -errno; 63 goto cleanup; 64 } 65 66 if (addrlen != sizeof(sa)) { 67 ret = -LIBBPF_ERRNO__INTERNAL; 68 goto cleanup; 69 } 70 71 *nl_pid = sa.nl_pid; 72 return sock; 73 74 cleanup: 75 close(sock); 76 return ret; 77 } 78 79 static void libbpf_netlink_close(int sock) 80 { 81 close(sock); 82 } 83 84 enum { 85 NL_CONT, 86 NL_NEXT, 87 NL_DONE, 88 }; 89 90 static int libbpf_netlink_recv(int sock, __u32 nl_pid, int seq, 91 __dump_nlmsg_t _fn, libbpf_dump_nlmsg_t fn, 92 void *cookie) 93 { 94 bool multipart = true; 95 struct nlmsgerr *err; 96 struct nlmsghdr *nh; 97 char buf[4096]; 98 int len, ret; 99 100 while (multipart) { 101 start: 102 multipart = false; 103 len = recv(sock, buf, sizeof(buf), 0); 104 if (len < 0) { 105 ret = -errno; 106 goto done; 107 } 108 109 if (len == 0) 110 break; 111 112 for (nh = (struct nlmsghdr *)buf; NLMSG_OK(nh, len); 113 nh = NLMSG_NEXT(nh, len)) { 114 if (nh->nlmsg_pid != nl_pid) { 115 ret = -LIBBPF_ERRNO__WRNGPID; 116 goto done; 117 } 118 if (nh->nlmsg_seq != seq) { 119 ret = -LIBBPF_ERRNO__INVSEQ; 120 goto done; 121 } 122 if (nh->nlmsg_flags & NLM_F_MULTI) 123 multipart = true; 124 switch (nh->nlmsg_type) { 125 case NLMSG_ERROR: 126 err = (struct nlmsgerr *)NLMSG_DATA(nh); 127 if (!err->error) 128 continue; 129 ret = err->error; 130 libbpf_nla_dump_errormsg(nh); 131 goto done; 132 case NLMSG_DONE: 133 return 0; 134 default: 135 break; 136 } 137 if (_fn) { 138 ret = _fn(nh, fn, cookie); 139 switch (ret) { 140 case NL_CONT: 141 break; 142 case NL_NEXT: 143 goto start; 144 case NL_DONE: 145 return 0; 146 default: 147 return ret; 148 } 149 } 150 } 151 } 152 ret = 0; 153 done: 154 return ret; 155 } 156 157 static int libbpf_netlink_send_recv(struct libbpf_nla_req *req, 158 __dump_nlmsg_t parse_msg, 159 libbpf_dump_nlmsg_t parse_attr, 160 void *cookie) 161 { 162 __u32 nl_pid = 0; 163 int sock, ret; 164 165 sock = libbpf_netlink_open(&nl_pid); 166 if (sock < 0) 167 return sock; 168 169 req->nh.nlmsg_pid = 0; 170 req->nh.nlmsg_seq = time(NULL); 171 172 if (send(sock, req, req->nh.nlmsg_len, 0) < 0) { 173 ret = -errno; 174 goto out; 175 } 176 177 ret = libbpf_netlink_recv(sock, nl_pid, req->nh.nlmsg_seq, 178 parse_msg, parse_attr, cookie); 179 out: 180 libbpf_netlink_close(sock); 181 return ret; 182 } 183 184 static int __bpf_set_link_xdp_fd_replace(int ifindex, int fd, int old_fd, 185 __u32 flags) 186 { 187 struct nlattr *nla; 188 int ret; 189 struct libbpf_nla_req req; 190 191 memset(&req, 0, sizeof(req)); 192 req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg)); 193 req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK; 194 req.nh.nlmsg_type = RTM_SETLINK; 195 req.ifinfo.ifi_family = AF_UNSPEC; 196 req.ifinfo.ifi_index = ifindex; 197 198 nla = nlattr_begin_nested(&req, IFLA_XDP); 199 if (!nla) 200 return -EMSGSIZE; 201 ret = nlattr_add(&req, IFLA_XDP_FD, &fd, sizeof(fd)); 202 if (ret < 0) 203 return ret; 204 if (flags) { 205 ret = nlattr_add(&req, IFLA_XDP_FLAGS, &flags, sizeof(flags)); 206 if (ret < 0) 207 return ret; 208 } 209 if (flags & XDP_FLAGS_REPLACE) { 210 ret = nlattr_add(&req, IFLA_XDP_EXPECTED_FD, &old_fd, 211 sizeof(old_fd)); 212 if (ret < 0) 213 return ret; 214 } 215 nlattr_end_nested(&req, nla); 216 217 return libbpf_netlink_send_recv(&req, NULL, NULL, NULL); 218 } 219 220 int bpf_set_link_xdp_fd_opts(int ifindex, int fd, __u32 flags, 221 const struct bpf_xdp_set_link_opts *opts) 222 { 223 int old_fd = -1, ret; 224 225 if (!OPTS_VALID(opts, bpf_xdp_set_link_opts)) 226 return libbpf_err(-EINVAL); 227 228 if (OPTS_HAS(opts, old_fd)) { 229 old_fd = OPTS_GET(opts, old_fd, -1); 230 flags |= XDP_FLAGS_REPLACE; 231 } 232 233 ret = __bpf_set_link_xdp_fd_replace(ifindex, fd, old_fd, flags); 234 return libbpf_err(ret); 235 } 236 237 int bpf_set_link_xdp_fd(int ifindex, int fd, __u32 flags) 238 { 239 int ret; 240 241 ret = __bpf_set_link_xdp_fd_replace(ifindex, fd, 0, flags); 242 return libbpf_err(ret); 243 } 244 245 static int __dump_link_nlmsg(struct nlmsghdr *nlh, 246 libbpf_dump_nlmsg_t dump_link_nlmsg, void *cookie) 247 { 248 struct nlattr *tb[IFLA_MAX + 1], *attr; 249 struct ifinfomsg *ifi = NLMSG_DATA(nlh); 250 int len; 251 252 len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*ifi)); 253 attr = (struct nlattr *) ((void *) ifi + NLMSG_ALIGN(sizeof(*ifi))); 254 255 if (libbpf_nla_parse(tb, IFLA_MAX, attr, len, NULL) != 0) 256 return -LIBBPF_ERRNO__NLPARSE; 257 258 return dump_link_nlmsg(cookie, ifi, tb); 259 } 260 261 static int get_xdp_info(void *cookie, void *msg, struct nlattr **tb) 262 { 263 struct nlattr *xdp_tb[IFLA_XDP_MAX + 1]; 264 struct xdp_id_md *xdp_id = cookie; 265 struct ifinfomsg *ifinfo = msg; 266 int ret; 267 268 if (xdp_id->ifindex && xdp_id->ifindex != ifinfo->ifi_index) 269 return 0; 270 271 if (!tb[IFLA_XDP]) 272 return 0; 273 274 ret = libbpf_nla_parse_nested(xdp_tb, IFLA_XDP_MAX, tb[IFLA_XDP], NULL); 275 if (ret) 276 return ret; 277 278 if (!xdp_tb[IFLA_XDP_ATTACHED]) 279 return 0; 280 281 xdp_id->info.attach_mode = libbpf_nla_getattr_u8( 282 xdp_tb[IFLA_XDP_ATTACHED]); 283 284 if (xdp_id->info.attach_mode == XDP_ATTACHED_NONE) 285 return 0; 286 287 if (xdp_tb[IFLA_XDP_PROG_ID]) 288 xdp_id->info.prog_id = libbpf_nla_getattr_u32( 289 xdp_tb[IFLA_XDP_PROG_ID]); 290 291 if (xdp_tb[IFLA_XDP_SKB_PROG_ID]) 292 xdp_id->info.skb_prog_id = libbpf_nla_getattr_u32( 293 xdp_tb[IFLA_XDP_SKB_PROG_ID]); 294 295 if (xdp_tb[IFLA_XDP_DRV_PROG_ID]) 296 xdp_id->info.drv_prog_id = libbpf_nla_getattr_u32( 297 xdp_tb[IFLA_XDP_DRV_PROG_ID]); 298 299 if (xdp_tb[IFLA_XDP_HW_PROG_ID]) 300 xdp_id->info.hw_prog_id = libbpf_nla_getattr_u32( 301 xdp_tb[IFLA_XDP_HW_PROG_ID]); 302 303 return 0; 304 } 305 306 int bpf_get_link_xdp_info(int ifindex, struct xdp_link_info *info, 307 size_t info_size, __u32 flags) 308 { 309 struct xdp_id_md xdp_id = {}; 310 __u32 mask; 311 int ret; 312 struct libbpf_nla_req req = { 313 .nh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg)), 314 .nh.nlmsg_type = RTM_GETLINK, 315 .nh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST, 316 .ifinfo.ifi_family = AF_PACKET, 317 }; 318 319 if (flags & ~XDP_FLAGS_MASK || !info_size) 320 return libbpf_err(-EINVAL); 321 322 /* Check whether the single {HW,DRV,SKB} mode is set */ 323 flags &= (XDP_FLAGS_SKB_MODE | XDP_FLAGS_DRV_MODE | XDP_FLAGS_HW_MODE); 324 mask = flags - 1; 325 if (flags && flags & mask) 326 return libbpf_err(-EINVAL); 327 328 xdp_id.ifindex = ifindex; 329 xdp_id.flags = flags; 330 331 ret = libbpf_netlink_send_recv(&req, __dump_link_nlmsg, 332 get_xdp_info, &xdp_id); 333 if (!ret) { 334 size_t sz = min(info_size, sizeof(xdp_id.info)); 335 336 memcpy(info, &xdp_id.info, sz); 337 memset((void *) info + sz, 0, info_size - sz); 338 } 339 340 return libbpf_err(ret); 341 } 342 343 static __u32 get_xdp_id(struct xdp_link_info *info, __u32 flags) 344 { 345 flags &= XDP_FLAGS_MODES; 346 347 if (info->attach_mode != XDP_ATTACHED_MULTI && !flags) 348 return info->prog_id; 349 if (flags & XDP_FLAGS_DRV_MODE) 350 return info->drv_prog_id; 351 if (flags & XDP_FLAGS_HW_MODE) 352 return info->hw_prog_id; 353 if (flags & XDP_FLAGS_SKB_MODE) 354 return info->skb_prog_id; 355 356 return 0; 357 } 358 359 int bpf_get_link_xdp_id(int ifindex, __u32 *prog_id, __u32 flags) 360 { 361 struct xdp_link_info info; 362 int ret; 363 364 ret = bpf_get_link_xdp_info(ifindex, &info, sizeof(info), flags); 365 if (!ret) 366 *prog_id = get_xdp_id(&info, flags); 367 368 return libbpf_err(ret); 369 } 370 371 typedef int (*qdisc_config_t)(struct libbpf_nla_req *req); 372 373 static int clsact_config(struct libbpf_nla_req *req) 374 { 375 req->tc.tcm_parent = TC_H_CLSACT; 376 req->tc.tcm_handle = TC_H_MAKE(TC_H_CLSACT, 0); 377 378 return nlattr_add(req, TCA_KIND, "clsact", sizeof("clsact")); 379 } 380 381 static int attach_point_to_config(struct bpf_tc_hook *hook, 382 qdisc_config_t *config) 383 { 384 switch (OPTS_GET(hook, attach_point, 0)) { 385 case BPF_TC_INGRESS: 386 case BPF_TC_EGRESS: 387 case BPF_TC_INGRESS | BPF_TC_EGRESS: 388 if (OPTS_GET(hook, parent, 0)) 389 return -EINVAL; 390 *config = &clsact_config; 391 return 0; 392 case BPF_TC_CUSTOM: 393 return -EOPNOTSUPP; 394 default: 395 return -EINVAL; 396 } 397 } 398 399 static int tc_get_tcm_parent(enum bpf_tc_attach_point attach_point, 400 __u32 *parent) 401 { 402 switch (attach_point) { 403 case BPF_TC_INGRESS: 404 case BPF_TC_EGRESS: 405 if (*parent) 406 return -EINVAL; 407 *parent = TC_H_MAKE(TC_H_CLSACT, 408 attach_point == BPF_TC_INGRESS ? 409 TC_H_MIN_INGRESS : TC_H_MIN_EGRESS); 410 break; 411 case BPF_TC_CUSTOM: 412 if (!*parent) 413 return -EINVAL; 414 break; 415 default: 416 return -EINVAL; 417 } 418 return 0; 419 } 420 421 static int tc_qdisc_modify(struct bpf_tc_hook *hook, int cmd, int flags) 422 { 423 qdisc_config_t config; 424 int ret; 425 struct libbpf_nla_req req; 426 427 ret = attach_point_to_config(hook, &config); 428 if (ret < 0) 429 return ret; 430 431 memset(&req, 0, sizeof(req)); 432 req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg)); 433 req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK | flags; 434 req.nh.nlmsg_type = cmd; 435 req.tc.tcm_family = AF_UNSPEC; 436 req.tc.tcm_ifindex = OPTS_GET(hook, ifindex, 0); 437 438 ret = config(&req); 439 if (ret < 0) 440 return ret; 441 442 return libbpf_netlink_send_recv(&req, NULL, NULL, NULL); 443 } 444 445 static int tc_qdisc_create_excl(struct bpf_tc_hook *hook) 446 { 447 return tc_qdisc_modify(hook, RTM_NEWQDISC, NLM_F_CREATE | NLM_F_EXCL); 448 } 449 450 static int tc_qdisc_delete(struct bpf_tc_hook *hook) 451 { 452 return tc_qdisc_modify(hook, RTM_DELQDISC, 0); 453 } 454 455 int bpf_tc_hook_create(struct bpf_tc_hook *hook) 456 { 457 int ret; 458 459 if (!hook || !OPTS_VALID(hook, bpf_tc_hook) || 460 OPTS_GET(hook, ifindex, 0) <= 0) 461 return libbpf_err(-EINVAL); 462 463 ret = tc_qdisc_create_excl(hook); 464 return libbpf_err(ret); 465 } 466 467 static int __bpf_tc_detach(const struct bpf_tc_hook *hook, 468 const struct bpf_tc_opts *opts, 469 const bool flush); 470 471 int bpf_tc_hook_destroy(struct bpf_tc_hook *hook) 472 { 473 if (!hook || !OPTS_VALID(hook, bpf_tc_hook) || 474 OPTS_GET(hook, ifindex, 0) <= 0) 475 return libbpf_err(-EINVAL); 476 477 switch (OPTS_GET(hook, attach_point, 0)) { 478 case BPF_TC_INGRESS: 479 case BPF_TC_EGRESS: 480 return libbpf_err(__bpf_tc_detach(hook, NULL, true)); 481 case BPF_TC_INGRESS | BPF_TC_EGRESS: 482 return libbpf_err(tc_qdisc_delete(hook)); 483 case BPF_TC_CUSTOM: 484 return libbpf_err(-EOPNOTSUPP); 485 default: 486 return libbpf_err(-EINVAL); 487 } 488 } 489 490 struct bpf_cb_ctx { 491 struct bpf_tc_opts *opts; 492 bool processed; 493 }; 494 495 static int __get_tc_info(void *cookie, struct tcmsg *tc, struct nlattr **tb, 496 bool unicast) 497 { 498 struct nlattr *tbb[TCA_BPF_MAX + 1]; 499 struct bpf_cb_ctx *info = cookie; 500 501 if (!info || !info->opts) 502 return -EINVAL; 503 if (unicast && info->processed) 504 return -EINVAL; 505 if (!tb[TCA_OPTIONS]) 506 return NL_CONT; 507 508 libbpf_nla_parse_nested(tbb, TCA_BPF_MAX, tb[TCA_OPTIONS], NULL); 509 if (!tbb[TCA_BPF_ID]) 510 return -EINVAL; 511 512 OPTS_SET(info->opts, prog_id, libbpf_nla_getattr_u32(tbb[TCA_BPF_ID])); 513 OPTS_SET(info->opts, handle, tc->tcm_handle); 514 OPTS_SET(info->opts, priority, TC_H_MAJ(tc->tcm_info) >> 16); 515 516 info->processed = true; 517 return unicast ? NL_NEXT : NL_DONE; 518 } 519 520 static int get_tc_info(struct nlmsghdr *nh, libbpf_dump_nlmsg_t fn, 521 void *cookie) 522 { 523 struct tcmsg *tc = NLMSG_DATA(nh); 524 struct nlattr *tb[TCA_MAX + 1]; 525 526 libbpf_nla_parse(tb, TCA_MAX, 527 (struct nlattr *)((void *)tc + NLMSG_ALIGN(sizeof(*tc))), 528 NLMSG_PAYLOAD(nh, sizeof(*tc)), NULL); 529 if (!tb[TCA_KIND]) 530 return NL_CONT; 531 return __get_tc_info(cookie, tc, tb, nh->nlmsg_flags & NLM_F_ECHO); 532 } 533 534 static int tc_add_fd_and_name(struct libbpf_nla_req *req, int fd) 535 { 536 struct bpf_prog_info info = {}; 537 __u32 info_len = sizeof(info); 538 char name[256]; 539 int len, ret; 540 541 ret = bpf_obj_get_info_by_fd(fd, &info, &info_len); 542 if (ret < 0) 543 return ret; 544 545 ret = nlattr_add(req, TCA_BPF_FD, &fd, sizeof(fd)); 546 if (ret < 0) 547 return ret; 548 len = snprintf(name, sizeof(name), "%s:[%u]", info.name, info.id); 549 if (len < 0) 550 return -errno; 551 if (len >= sizeof(name)) 552 return -ENAMETOOLONG; 553 return nlattr_add(req, TCA_BPF_NAME, name, len + 1); 554 } 555 556 int bpf_tc_attach(const struct bpf_tc_hook *hook, struct bpf_tc_opts *opts) 557 { 558 __u32 protocol, bpf_flags, handle, priority, parent, prog_id, flags; 559 int ret, ifindex, attach_point, prog_fd; 560 struct bpf_cb_ctx info = {}; 561 struct libbpf_nla_req req; 562 struct nlattr *nla; 563 564 if (!hook || !opts || 565 !OPTS_VALID(hook, bpf_tc_hook) || 566 !OPTS_VALID(opts, bpf_tc_opts)) 567 return libbpf_err(-EINVAL); 568 569 ifindex = OPTS_GET(hook, ifindex, 0); 570 parent = OPTS_GET(hook, parent, 0); 571 attach_point = OPTS_GET(hook, attach_point, 0); 572 573 handle = OPTS_GET(opts, handle, 0); 574 priority = OPTS_GET(opts, priority, 0); 575 prog_fd = OPTS_GET(opts, prog_fd, 0); 576 prog_id = OPTS_GET(opts, prog_id, 0); 577 flags = OPTS_GET(opts, flags, 0); 578 579 if (ifindex <= 0 || !prog_fd || prog_id) 580 return libbpf_err(-EINVAL); 581 if (priority > UINT16_MAX) 582 return libbpf_err(-EINVAL); 583 if (flags & ~BPF_TC_F_REPLACE) 584 return libbpf_err(-EINVAL); 585 586 flags = (flags & BPF_TC_F_REPLACE) ? NLM_F_REPLACE : NLM_F_EXCL; 587 protocol = ETH_P_ALL; 588 589 memset(&req, 0, sizeof(req)); 590 req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg)); 591 req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK | NLM_F_CREATE | 592 NLM_F_ECHO | flags; 593 req.nh.nlmsg_type = RTM_NEWTFILTER; 594 req.tc.tcm_family = AF_UNSPEC; 595 req.tc.tcm_ifindex = ifindex; 596 req.tc.tcm_handle = handle; 597 req.tc.tcm_info = TC_H_MAKE(priority << 16, htons(protocol)); 598 599 ret = tc_get_tcm_parent(attach_point, &parent); 600 if (ret < 0) 601 return libbpf_err(ret); 602 req.tc.tcm_parent = parent; 603 604 ret = nlattr_add(&req, TCA_KIND, "bpf", sizeof("bpf")); 605 if (ret < 0) 606 return libbpf_err(ret); 607 nla = nlattr_begin_nested(&req, TCA_OPTIONS); 608 if (!nla) 609 return libbpf_err(-EMSGSIZE); 610 ret = tc_add_fd_and_name(&req, prog_fd); 611 if (ret < 0) 612 return libbpf_err(ret); 613 bpf_flags = TCA_BPF_FLAG_ACT_DIRECT; 614 ret = nlattr_add(&req, TCA_BPF_FLAGS, &bpf_flags, sizeof(bpf_flags)); 615 if (ret < 0) 616 return libbpf_err(ret); 617 nlattr_end_nested(&req, nla); 618 619 info.opts = opts; 620 621 ret = libbpf_netlink_send_recv(&req, get_tc_info, NULL, &info); 622 if (ret < 0) 623 return libbpf_err(ret); 624 if (!info.processed) 625 return libbpf_err(-ENOENT); 626 return ret; 627 } 628 629 static int __bpf_tc_detach(const struct bpf_tc_hook *hook, 630 const struct bpf_tc_opts *opts, 631 const bool flush) 632 { 633 __u32 protocol = 0, handle, priority, parent, prog_id, flags; 634 int ret, ifindex, attach_point, prog_fd; 635 struct libbpf_nla_req req; 636 637 if (!hook || 638 !OPTS_VALID(hook, bpf_tc_hook) || 639 !OPTS_VALID(opts, bpf_tc_opts)) 640 return -EINVAL; 641 642 ifindex = OPTS_GET(hook, ifindex, 0); 643 parent = OPTS_GET(hook, parent, 0); 644 attach_point = OPTS_GET(hook, attach_point, 0); 645 646 handle = OPTS_GET(opts, handle, 0); 647 priority = OPTS_GET(opts, priority, 0); 648 prog_fd = OPTS_GET(opts, prog_fd, 0); 649 prog_id = OPTS_GET(opts, prog_id, 0); 650 flags = OPTS_GET(opts, flags, 0); 651 652 if (ifindex <= 0 || flags || prog_fd || prog_id) 653 return -EINVAL; 654 if (priority > UINT16_MAX) 655 return -EINVAL; 656 if (!flush) { 657 if (!handle || !priority) 658 return -EINVAL; 659 protocol = ETH_P_ALL; 660 } else { 661 if (handle || priority) 662 return -EINVAL; 663 } 664 665 memset(&req, 0, sizeof(req)); 666 req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg)); 667 req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK; 668 req.nh.nlmsg_type = RTM_DELTFILTER; 669 req.tc.tcm_family = AF_UNSPEC; 670 req.tc.tcm_ifindex = ifindex; 671 if (!flush) { 672 req.tc.tcm_handle = handle; 673 req.tc.tcm_info = TC_H_MAKE(priority << 16, htons(protocol)); 674 } 675 676 ret = tc_get_tcm_parent(attach_point, &parent); 677 if (ret < 0) 678 return ret; 679 req.tc.tcm_parent = parent; 680 681 if (!flush) { 682 ret = nlattr_add(&req, TCA_KIND, "bpf", sizeof("bpf")); 683 if (ret < 0) 684 return ret; 685 } 686 687 return libbpf_netlink_send_recv(&req, NULL, NULL, NULL); 688 } 689 690 int bpf_tc_detach(const struct bpf_tc_hook *hook, 691 const struct bpf_tc_opts *opts) 692 { 693 int ret; 694 695 if (!opts) 696 return libbpf_err(-EINVAL); 697 698 ret = __bpf_tc_detach(hook, opts, false); 699 return libbpf_err(ret); 700 } 701 702 int bpf_tc_query(const struct bpf_tc_hook *hook, struct bpf_tc_opts *opts) 703 { 704 __u32 protocol, handle, priority, parent, prog_id, flags; 705 int ret, ifindex, attach_point, prog_fd; 706 struct bpf_cb_ctx info = {}; 707 struct libbpf_nla_req req; 708 709 if (!hook || !opts || 710 !OPTS_VALID(hook, bpf_tc_hook) || 711 !OPTS_VALID(opts, bpf_tc_opts)) 712 return libbpf_err(-EINVAL); 713 714 ifindex = OPTS_GET(hook, ifindex, 0); 715 parent = OPTS_GET(hook, parent, 0); 716 attach_point = OPTS_GET(hook, attach_point, 0); 717 718 handle = OPTS_GET(opts, handle, 0); 719 priority = OPTS_GET(opts, priority, 0); 720 prog_fd = OPTS_GET(opts, prog_fd, 0); 721 prog_id = OPTS_GET(opts, prog_id, 0); 722 flags = OPTS_GET(opts, flags, 0); 723 724 if (ifindex <= 0 || flags || prog_fd || prog_id || 725 !handle || !priority) 726 return libbpf_err(-EINVAL); 727 if (priority > UINT16_MAX) 728 return libbpf_err(-EINVAL); 729 730 protocol = ETH_P_ALL; 731 732 memset(&req, 0, sizeof(req)); 733 req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg)); 734 req.nh.nlmsg_flags = NLM_F_REQUEST; 735 req.nh.nlmsg_type = RTM_GETTFILTER; 736 req.tc.tcm_family = AF_UNSPEC; 737 req.tc.tcm_ifindex = ifindex; 738 req.tc.tcm_handle = handle; 739 req.tc.tcm_info = TC_H_MAKE(priority << 16, htons(protocol)); 740 741 ret = tc_get_tcm_parent(attach_point, &parent); 742 if (ret < 0) 743 return libbpf_err(ret); 744 req.tc.tcm_parent = parent; 745 746 ret = nlattr_add(&req, TCA_KIND, "bpf", sizeof("bpf")); 747 if (ret < 0) 748 return libbpf_err(ret); 749 750 info.opts = opts; 751 752 ret = libbpf_netlink_send_recv(&req, get_tc_info, NULL, &info); 753 if (ret < 0) 754 return libbpf_err(ret); 755 if (!info.processed) 756 return libbpf_err(-ENOENT); 757 return ret; 758 } 759