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 netlink_recvmsg(int sock, struct msghdr *mhdr, int flags) 91 { 92 int len; 93 94 do { 95 len = recvmsg(sock, mhdr, flags); 96 } while (len < 0 && (errno == EINTR || errno == EAGAIN)); 97 98 if (len < 0) 99 return -errno; 100 return len; 101 } 102 103 static int alloc_iov(struct iovec *iov, int len) 104 { 105 void *nbuf; 106 107 nbuf = realloc(iov->iov_base, len); 108 if (!nbuf) 109 return -ENOMEM; 110 111 iov->iov_base = nbuf; 112 iov->iov_len = len; 113 return 0; 114 } 115 116 static int libbpf_netlink_recv(int sock, __u32 nl_pid, int seq, 117 __dump_nlmsg_t _fn, libbpf_dump_nlmsg_t fn, 118 void *cookie) 119 { 120 struct iovec iov = {}; 121 struct msghdr mhdr = { 122 .msg_iov = &iov, 123 .msg_iovlen = 1, 124 }; 125 bool multipart = true; 126 struct nlmsgerr *err; 127 struct nlmsghdr *nh; 128 int len, ret; 129 130 ret = alloc_iov(&iov, 4096); 131 if (ret) 132 goto done; 133 134 while (multipart) { 135 start: 136 multipart = false; 137 len = netlink_recvmsg(sock, &mhdr, MSG_PEEK | MSG_TRUNC); 138 if (len < 0) { 139 ret = len; 140 goto done; 141 } 142 143 if (len > iov.iov_len) { 144 ret = alloc_iov(&iov, len); 145 if (ret) 146 goto done; 147 } 148 149 len = netlink_recvmsg(sock, &mhdr, 0); 150 if (len < 0) { 151 ret = len; 152 goto done; 153 } 154 155 if (len == 0) 156 break; 157 158 for (nh = (struct nlmsghdr *)iov.iov_base; NLMSG_OK(nh, len); 159 nh = NLMSG_NEXT(nh, len)) { 160 if (nh->nlmsg_pid != nl_pid) { 161 ret = -LIBBPF_ERRNO__WRNGPID; 162 goto done; 163 } 164 if (nh->nlmsg_seq != seq) { 165 ret = -LIBBPF_ERRNO__INVSEQ; 166 goto done; 167 } 168 if (nh->nlmsg_flags & NLM_F_MULTI) 169 multipart = true; 170 switch (nh->nlmsg_type) { 171 case NLMSG_ERROR: 172 err = (struct nlmsgerr *)NLMSG_DATA(nh); 173 if (!err->error) 174 continue; 175 ret = err->error; 176 libbpf_nla_dump_errormsg(nh); 177 goto done; 178 case NLMSG_DONE: 179 return 0; 180 default: 181 break; 182 } 183 if (_fn) { 184 ret = _fn(nh, fn, cookie); 185 switch (ret) { 186 case NL_CONT: 187 break; 188 case NL_NEXT: 189 goto start; 190 case NL_DONE: 191 return 0; 192 default: 193 return ret; 194 } 195 } 196 } 197 } 198 ret = 0; 199 done: 200 free(iov.iov_base); 201 return ret; 202 } 203 204 static int libbpf_netlink_send_recv(struct libbpf_nla_req *req, 205 __dump_nlmsg_t parse_msg, 206 libbpf_dump_nlmsg_t parse_attr, 207 void *cookie) 208 { 209 __u32 nl_pid = 0; 210 int sock, ret; 211 212 sock = libbpf_netlink_open(&nl_pid); 213 if (sock < 0) 214 return sock; 215 216 req->nh.nlmsg_pid = 0; 217 req->nh.nlmsg_seq = time(NULL); 218 219 if (send(sock, req, req->nh.nlmsg_len, 0) < 0) { 220 ret = -errno; 221 goto out; 222 } 223 224 ret = libbpf_netlink_recv(sock, nl_pid, req->nh.nlmsg_seq, 225 parse_msg, parse_attr, cookie); 226 out: 227 libbpf_netlink_close(sock); 228 return ret; 229 } 230 231 static int __bpf_set_link_xdp_fd_replace(int ifindex, int fd, int old_fd, 232 __u32 flags) 233 { 234 struct nlattr *nla; 235 int ret; 236 struct libbpf_nla_req req; 237 238 memset(&req, 0, sizeof(req)); 239 req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg)); 240 req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK; 241 req.nh.nlmsg_type = RTM_SETLINK; 242 req.ifinfo.ifi_family = AF_UNSPEC; 243 req.ifinfo.ifi_index = ifindex; 244 245 nla = nlattr_begin_nested(&req, IFLA_XDP); 246 if (!nla) 247 return -EMSGSIZE; 248 ret = nlattr_add(&req, IFLA_XDP_FD, &fd, sizeof(fd)); 249 if (ret < 0) 250 return ret; 251 if (flags) { 252 ret = nlattr_add(&req, IFLA_XDP_FLAGS, &flags, sizeof(flags)); 253 if (ret < 0) 254 return ret; 255 } 256 if (flags & XDP_FLAGS_REPLACE) { 257 ret = nlattr_add(&req, IFLA_XDP_EXPECTED_FD, &old_fd, 258 sizeof(old_fd)); 259 if (ret < 0) 260 return ret; 261 } 262 nlattr_end_nested(&req, nla); 263 264 return libbpf_netlink_send_recv(&req, NULL, NULL, NULL); 265 } 266 267 int bpf_xdp_attach(int ifindex, int prog_fd, __u32 flags, const struct bpf_xdp_attach_opts *opts) 268 { 269 int old_prog_fd, err; 270 271 if (!OPTS_VALID(opts, bpf_xdp_attach_opts)) 272 return libbpf_err(-EINVAL); 273 274 old_prog_fd = OPTS_GET(opts, old_prog_fd, 0); 275 if (old_prog_fd) 276 flags |= XDP_FLAGS_REPLACE; 277 else 278 old_prog_fd = -1; 279 280 err = __bpf_set_link_xdp_fd_replace(ifindex, prog_fd, old_prog_fd, flags); 281 return libbpf_err(err); 282 } 283 284 int bpf_xdp_detach(int ifindex, __u32 flags, const struct bpf_xdp_attach_opts *opts) 285 { 286 return bpf_xdp_attach(ifindex, -1, flags, opts); 287 } 288 289 int bpf_set_link_xdp_fd_opts(int ifindex, int fd, __u32 flags, 290 const struct bpf_xdp_set_link_opts *opts) 291 { 292 int old_fd = -1, ret; 293 294 if (!OPTS_VALID(opts, bpf_xdp_set_link_opts)) 295 return libbpf_err(-EINVAL); 296 297 if (OPTS_HAS(opts, old_fd)) { 298 old_fd = OPTS_GET(opts, old_fd, -1); 299 flags |= XDP_FLAGS_REPLACE; 300 } 301 302 ret = __bpf_set_link_xdp_fd_replace(ifindex, fd, old_fd, flags); 303 return libbpf_err(ret); 304 } 305 306 int bpf_set_link_xdp_fd(int ifindex, int fd, __u32 flags) 307 { 308 int ret; 309 310 ret = __bpf_set_link_xdp_fd_replace(ifindex, fd, 0, flags); 311 return libbpf_err(ret); 312 } 313 314 static int __dump_link_nlmsg(struct nlmsghdr *nlh, 315 libbpf_dump_nlmsg_t dump_link_nlmsg, void *cookie) 316 { 317 struct nlattr *tb[IFLA_MAX + 1], *attr; 318 struct ifinfomsg *ifi = NLMSG_DATA(nlh); 319 int len; 320 321 len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*ifi)); 322 attr = (struct nlattr *) ((void *) ifi + NLMSG_ALIGN(sizeof(*ifi))); 323 324 if (libbpf_nla_parse(tb, IFLA_MAX, attr, len, NULL) != 0) 325 return -LIBBPF_ERRNO__NLPARSE; 326 327 return dump_link_nlmsg(cookie, ifi, tb); 328 } 329 330 static int get_xdp_info(void *cookie, void *msg, struct nlattr **tb) 331 { 332 struct nlattr *xdp_tb[IFLA_XDP_MAX + 1]; 333 struct xdp_id_md *xdp_id = cookie; 334 struct ifinfomsg *ifinfo = msg; 335 int ret; 336 337 if (xdp_id->ifindex && xdp_id->ifindex != ifinfo->ifi_index) 338 return 0; 339 340 if (!tb[IFLA_XDP]) 341 return 0; 342 343 ret = libbpf_nla_parse_nested(xdp_tb, IFLA_XDP_MAX, tb[IFLA_XDP], NULL); 344 if (ret) 345 return ret; 346 347 if (!xdp_tb[IFLA_XDP_ATTACHED]) 348 return 0; 349 350 xdp_id->info.attach_mode = libbpf_nla_getattr_u8( 351 xdp_tb[IFLA_XDP_ATTACHED]); 352 353 if (xdp_id->info.attach_mode == XDP_ATTACHED_NONE) 354 return 0; 355 356 if (xdp_tb[IFLA_XDP_PROG_ID]) 357 xdp_id->info.prog_id = libbpf_nla_getattr_u32( 358 xdp_tb[IFLA_XDP_PROG_ID]); 359 360 if (xdp_tb[IFLA_XDP_SKB_PROG_ID]) 361 xdp_id->info.skb_prog_id = libbpf_nla_getattr_u32( 362 xdp_tb[IFLA_XDP_SKB_PROG_ID]); 363 364 if (xdp_tb[IFLA_XDP_DRV_PROG_ID]) 365 xdp_id->info.drv_prog_id = libbpf_nla_getattr_u32( 366 xdp_tb[IFLA_XDP_DRV_PROG_ID]); 367 368 if (xdp_tb[IFLA_XDP_HW_PROG_ID]) 369 xdp_id->info.hw_prog_id = libbpf_nla_getattr_u32( 370 xdp_tb[IFLA_XDP_HW_PROG_ID]); 371 372 return 0; 373 } 374 375 int bpf_xdp_query(int ifindex, int xdp_flags, struct bpf_xdp_query_opts *opts) 376 { 377 struct libbpf_nla_req req = { 378 .nh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg)), 379 .nh.nlmsg_type = RTM_GETLINK, 380 .nh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST, 381 .ifinfo.ifi_family = AF_PACKET, 382 }; 383 struct xdp_id_md xdp_id = {}; 384 int err; 385 386 if (!OPTS_VALID(opts, bpf_xdp_query_opts)) 387 return libbpf_err(-EINVAL); 388 389 if (xdp_flags & ~XDP_FLAGS_MASK) 390 return libbpf_err(-EINVAL); 391 392 /* Check whether the single {HW,DRV,SKB} mode is set */ 393 xdp_flags &= XDP_FLAGS_SKB_MODE | XDP_FLAGS_DRV_MODE | XDP_FLAGS_HW_MODE; 394 if (xdp_flags & (xdp_flags - 1)) 395 return libbpf_err(-EINVAL); 396 397 xdp_id.ifindex = ifindex; 398 xdp_id.flags = xdp_flags; 399 400 err = libbpf_netlink_send_recv(&req, __dump_link_nlmsg, 401 get_xdp_info, &xdp_id); 402 if (err) 403 return libbpf_err(err); 404 405 OPTS_SET(opts, prog_id, xdp_id.info.prog_id); 406 OPTS_SET(opts, drv_prog_id, xdp_id.info.drv_prog_id); 407 OPTS_SET(opts, hw_prog_id, xdp_id.info.hw_prog_id); 408 OPTS_SET(opts, skb_prog_id, xdp_id.info.skb_prog_id); 409 OPTS_SET(opts, attach_mode, xdp_id.info.attach_mode); 410 411 return 0; 412 } 413 414 int bpf_get_link_xdp_info(int ifindex, struct xdp_link_info *info, 415 size_t info_size, __u32 flags) 416 { 417 LIBBPF_OPTS(bpf_xdp_query_opts, opts); 418 size_t sz; 419 int err; 420 421 if (!info_size) 422 return libbpf_err(-EINVAL); 423 424 err = bpf_xdp_query(ifindex, flags, &opts); 425 if (err) 426 return libbpf_err(err); 427 428 /* struct xdp_link_info field layout matches struct bpf_xdp_query_opts 429 * layout after sz field 430 */ 431 sz = min(info_size, offsetofend(struct xdp_link_info, attach_mode)); 432 memcpy(info, &opts.prog_id, sz); 433 memset((void *)info + sz, 0, info_size - sz); 434 435 return 0; 436 } 437 438 int bpf_xdp_query_id(int ifindex, int flags, __u32 *prog_id) 439 { 440 LIBBPF_OPTS(bpf_xdp_query_opts, opts); 441 int ret; 442 443 ret = bpf_xdp_query(ifindex, flags, &opts); 444 if (ret) 445 return libbpf_err(ret); 446 447 flags &= XDP_FLAGS_MODES; 448 449 if (opts.attach_mode != XDP_ATTACHED_MULTI && !flags) 450 *prog_id = opts.prog_id; 451 else if (flags & XDP_FLAGS_DRV_MODE) 452 *prog_id = opts.drv_prog_id; 453 else if (flags & XDP_FLAGS_HW_MODE) 454 *prog_id = opts.hw_prog_id; 455 else if (flags & XDP_FLAGS_SKB_MODE) 456 *prog_id = opts.skb_prog_id; 457 else 458 *prog_id = 0; 459 460 return 0; 461 } 462 463 464 int bpf_get_link_xdp_id(int ifindex, __u32 *prog_id, __u32 flags) 465 { 466 return bpf_xdp_query_id(ifindex, flags, prog_id); 467 } 468 469 typedef int (*qdisc_config_t)(struct libbpf_nla_req *req); 470 471 static int clsact_config(struct libbpf_nla_req *req) 472 { 473 req->tc.tcm_parent = TC_H_CLSACT; 474 req->tc.tcm_handle = TC_H_MAKE(TC_H_CLSACT, 0); 475 476 return nlattr_add(req, TCA_KIND, "clsact", sizeof("clsact")); 477 } 478 479 static int attach_point_to_config(struct bpf_tc_hook *hook, 480 qdisc_config_t *config) 481 { 482 switch (OPTS_GET(hook, attach_point, 0)) { 483 case BPF_TC_INGRESS: 484 case BPF_TC_EGRESS: 485 case BPF_TC_INGRESS | BPF_TC_EGRESS: 486 if (OPTS_GET(hook, parent, 0)) 487 return -EINVAL; 488 *config = &clsact_config; 489 return 0; 490 case BPF_TC_CUSTOM: 491 return -EOPNOTSUPP; 492 default: 493 return -EINVAL; 494 } 495 } 496 497 static int tc_get_tcm_parent(enum bpf_tc_attach_point attach_point, 498 __u32 *parent) 499 { 500 switch (attach_point) { 501 case BPF_TC_INGRESS: 502 case BPF_TC_EGRESS: 503 if (*parent) 504 return -EINVAL; 505 *parent = TC_H_MAKE(TC_H_CLSACT, 506 attach_point == BPF_TC_INGRESS ? 507 TC_H_MIN_INGRESS : TC_H_MIN_EGRESS); 508 break; 509 case BPF_TC_CUSTOM: 510 if (!*parent) 511 return -EINVAL; 512 break; 513 default: 514 return -EINVAL; 515 } 516 return 0; 517 } 518 519 static int tc_qdisc_modify(struct bpf_tc_hook *hook, int cmd, int flags) 520 { 521 qdisc_config_t config; 522 int ret; 523 struct libbpf_nla_req req; 524 525 ret = attach_point_to_config(hook, &config); 526 if (ret < 0) 527 return ret; 528 529 memset(&req, 0, sizeof(req)); 530 req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg)); 531 req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK | flags; 532 req.nh.nlmsg_type = cmd; 533 req.tc.tcm_family = AF_UNSPEC; 534 req.tc.tcm_ifindex = OPTS_GET(hook, ifindex, 0); 535 536 ret = config(&req); 537 if (ret < 0) 538 return ret; 539 540 return libbpf_netlink_send_recv(&req, NULL, NULL, NULL); 541 } 542 543 static int tc_qdisc_create_excl(struct bpf_tc_hook *hook) 544 { 545 return tc_qdisc_modify(hook, RTM_NEWQDISC, NLM_F_CREATE | NLM_F_EXCL); 546 } 547 548 static int tc_qdisc_delete(struct bpf_tc_hook *hook) 549 { 550 return tc_qdisc_modify(hook, RTM_DELQDISC, 0); 551 } 552 553 int bpf_tc_hook_create(struct bpf_tc_hook *hook) 554 { 555 int ret; 556 557 if (!hook || !OPTS_VALID(hook, bpf_tc_hook) || 558 OPTS_GET(hook, ifindex, 0) <= 0) 559 return libbpf_err(-EINVAL); 560 561 ret = tc_qdisc_create_excl(hook); 562 return libbpf_err(ret); 563 } 564 565 static int __bpf_tc_detach(const struct bpf_tc_hook *hook, 566 const struct bpf_tc_opts *opts, 567 const bool flush); 568 569 int bpf_tc_hook_destroy(struct bpf_tc_hook *hook) 570 { 571 if (!hook || !OPTS_VALID(hook, bpf_tc_hook) || 572 OPTS_GET(hook, ifindex, 0) <= 0) 573 return libbpf_err(-EINVAL); 574 575 switch (OPTS_GET(hook, attach_point, 0)) { 576 case BPF_TC_INGRESS: 577 case BPF_TC_EGRESS: 578 return libbpf_err(__bpf_tc_detach(hook, NULL, true)); 579 case BPF_TC_INGRESS | BPF_TC_EGRESS: 580 return libbpf_err(tc_qdisc_delete(hook)); 581 case BPF_TC_CUSTOM: 582 return libbpf_err(-EOPNOTSUPP); 583 default: 584 return libbpf_err(-EINVAL); 585 } 586 } 587 588 struct bpf_cb_ctx { 589 struct bpf_tc_opts *opts; 590 bool processed; 591 }; 592 593 static int __get_tc_info(void *cookie, struct tcmsg *tc, struct nlattr **tb, 594 bool unicast) 595 { 596 struct nlattr *tbb[TCA_BPF_MAX + 1]; 597 struct bpf_cb_ctx *info = cookie; 598 599 if (!info || !info->opts) 600 return -EINVAL; 601 if (unicast && info->processed) 602 return -EINVAL; 603 if (!tb[TCA_OPTIONS]) 604 return NL_CONT; 605 606 libbpf_nla_parse_nested(tbb, TCA_BPF_MAX, tb[TCA_OPTIONS], NULL); 607 if (!tbb[TCA_BPF_ID]) 608 return -EINVAL; 609 610 OPTS_SET(info->opts, prog_id, libbpf_nla_getattr_u32(tbb[TCA_BPF_ID])); 611 OPTS_SET(info->opts, handle, tc->tcm_handle); 612 OPTS_SET(info->opts, priority, TC_H_MAJ(tc->tcm_info) >> 16); 613 614 info->processed = true; 615 return unicast ? NL_NEXT : NL_DONE; 616 } 617 618 static int get_tc_info(struct nlmsghdr *nh, libbpf_dump_nlmsg_t fn, 619 void *cookie) 620 { 621 struct tcmsg *tc = NLMSG_DATA(nh); 622 struct nlattr *tb[TCA_MAX + 1]; 623 624 libbpf_nla_parse(tb, TCA_MAX, 625 (struct nlattr *)((void *)tc + NLMSG_ALIGN(sizeof(*tc))), 626 NLMSG_PAYLOAD(nh, sizeof(*tc)), NULL); 627 if (!tb[TCA_KIND]) 628 return NL_CONT; 629 return __get_tc_info(cookie, tc, tb, nh->nlmsg_flags & NLM_F_ECHO); 630 } 631 632 static int tc_add_fd_and_name(struct libbpf_nla_req *req, int fd) 633 { 634 struct bpf_prog_info info = {}; 635 __u32 info_len = sizeof(info); 636 char name[256]; 637 int len, ret; 638 639 ret = bpf_obj_get_info_by_fd(fd, &info, &info_len); 640 if (ret < 0) 641 return ret; 642 643 ret = nlattr_add(req, TCA_BPF_FD, &fd, sizeof(fd)); 644 if (ret < 0) 645 return ret; 646 len = snprintf(name, sizeof(name), "%s:[%u]", info.name, info.id); 647 if (len < 0) 648 return -errno; 649 if (len >= sizeof(name)) 650 return -ENAMETOOLONG; 651 return nlattr_add(req, TCA_BPF_NAME, name, len + 1); 652 } 653 654 int bpf_tc_attach(const struct bpf_tc_hook *hook, struct bpf_tc_opts *opts) 655 { 656 __u32 protocol, bpf_flags, handle, priority, parent, prog_id, flags; 657 int ret, ifindex, attach_point, prog_fd; 658 struct bpf_cb_ctx info = {}; 659 struct libbpf_nla_req req; 660 struct nlattr *nla; 661 662 if (!hook || !opts || 663 !OPTS_VALID(hook, bpf_tc_hook) || 664 !OPTS_VALID(opts, bpf_tc_opts)) 665 return libbpf_err(-EINVAL); 666 667 ifindex = OPTS_GET(hook, ifindex, 0); 668 parent = OPTS_GET(hook, parent, 0); 669 attach_point = OPTS_GET(hook, attach_point, 0); 670 671 handle = OPTS_GET(opts, handle, 0); 672 priority = OPTS_GET(opts, priority, 0); 673 prog_fd = OPTS_GET(opts, prog_fd, 0); 674 prog_id = OPTS_GET(opts, prog_id, 0); 675 flags = OPTS_GET(opts, flags, 0); 676 677 if (ifindex <= 0 || !prog_fd || prog_id) 678 return libbpf_err(-EINVAL); 679 if (priority > UINT16_MAX) 680 return libbpf_err(-EINVAL); 681 if (flags & ~BPF_TC_F_REPLACE) 682 return libbpf_err(-EINVAL); 683 684 flags = (flags & BPF_TC_F_REPLACE) ? NLM_F_REPLACE : NLM_F_EXCL; 685 protocol = ETH_P_ALL; 686 687 memset(&req, 0, sizeof(req)); 688 req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg)); 689 req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK | NLM_F_CREATE | 690 NLM_F_ECHO | flags; 691 req.nh.nlmsg_type = RTM_NEWTFILTER; 692 req.tc.tcm_family = AF_UNSPEC; 693 req.tc.tcm_ifindex = ifindex; 694 req.tc.tcm_handle = handle; 695 req.tc.tcm_info = TC_H_MAKE(priority << 16, htons(protocol)); 696 697 ret = tc_get_tcm_parent(attach_point, &parent); 698 if (ret < 0) 699 return libbpf_err(ret); 700 req.tc.tcm_parent = parent; 701 702 ret = nlattr_add(&req, TCA_KIND, "bpf", sizeof("bpf")); 703 if (ret < 0) 704 return libbpf_err(ret); 705 nla = nlattr_begin_nested(&req, TCA_OPTIONS); 706 if (!nla) 707 return libbpf_err(-EMSGSIZE); 708 ret = tc_add_fd_and_name(&req, prog_fd); 709 if (ret < 0) 710 return libbpf_err(ret); 711 bpf_flags = TCA_BPF_FLAG_ACT_DIRECT; 712 ret = nlattr_add(&req, TCA_BPF_FLAGS, &bpf_flags, sizeof(bpf_flags)); 713 if (ret < 0) 714 return libbpf_err(ret); 715 nlattr_end_nested(&req, nla); 716 717 info.opts = opts; 718 719 ret = libbpf_netlink_send_recv(&req, get_tc_info, NULL, &info); 720 if (ret < 0) 721 return libbpf_err(ret); 722 if (!info.processed) 723 return libbpf_err(-ENOENT); 724 return ret; 725 } 726 727 static int __bpf_tc_detach(const struct bpf_tc_hook *hook, 728 const struct bpf_tc_opts *opts, 729 const bool flush) 730 { 731 __u32 protocol = 0, handle, priority, parent, prog_id, flags; 732 int ret, ifindex, attach_point, prog_fd; 733 struct libbpf_nla_req req; 734 735 if (!hook || 736 !OPTS_VALID(hook, bpf_tc_hook) || 737 !OPTS_VALID(opts, bpf_tc_opts)) 738 return -EINVAL; 739 740 ifindex = OPTS_GET(hook, ifindex, 0); 741 parent = OPTS_GET(hook, parent, 0); 742 attach_point = OPTS_GET(hook, attach_point, 0); 743 744 handle = OPTS_GET(opts, handle, 0); 745 priority = OPTS_GET(opts, priority, 0); 746 prog_fd = OPTS_GET(opts, prog_fd, 0); 747 prog_id = OPTS_GET(opts, prog_id, 0); 748 flags = OPTS_GET(opts, flags, 0); 749 750 if (ifindex <= 0 || flags || prog_fd || prog_id) 751 return -EINVAL; 752 if (priority > UINT16_MAX) 753 return -EINVAL; 754 if (!flush) { 755 if (!handle || !priority) 756 return -EINVAL; 757 protocol = ETH_P_ALL; 758 } else { 759 if (handle || priority) 760 return -EINVAL; 761 } 762 763 memset(&req, 0, sizeof(req)); 764 req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg)); 765 req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK; 766 req.nh.nlmsg_type = RTM_DELTFILTER; 767 req.tc.tcm_family = AF_UNSPEC; 768 req.tc.tcm_ifindex = ifindex; 769 if (!flush) { 770 req.tc.tcm_handle = handle; 771 req.tc.tcm_info = TC_H_MAKE(priority << 16, htons(protocol)); 772 } 773 774 ret = tc_get_tcm_parent(attach_point, &parent); 775 if (ret < 0) 776 return ret; 777 req.tc.tcm_parent = parent; 778 779 if (!flush) { 780 ret = nlattr_add(&req, TCA_KIND, "bpf", sizeof("bpf")); 781 if (ret < 0) 782 return ret; 783 } 784 785 return libbpf_netlink_send_recv(&req, NULL, NULL, NULL); 786 } 787 788 int bpf_tc_detach(const struct bpf_tc_hook *hook, 789 const struct bpf_tc_opts *opts) 790 { 791 int ret; 792 793 if (!opts) 794 return libbpf_err(-EINVAL); 795 796 ret = __bpf_tc_detach(hook, opts, false); 797 return libbpf_err(ret); 798 } 799 800 int bpf_tc_query(const struct bpf_tc_hook *hook, struct bpf_tc_opts *opts) 801 { 802 __u32 protocol, handle, priority, parent, prog_id, flags; 803 int ret, ifindex, attach_point, prog_fd; 804 struct bpf_cb_ctx info = {}; 805 struct libbpf_nla_req req; 806 807 if (!hook || !opts || 808 !OPTS_VALID(hook, bpf_tc_hook) || 809 !OPTS_VALID(opts, bpf_tc_opts)) 810 return libbpf_err(-EINVAL); 811 812 ifindex = OPTS_GET(hook, ifindex, 0); 813 parent = OPTS_GET(hook, parent, 0); 814 attach_point = OPTS_GET(hook, attach_point, 0); 815 816 handle = OPTS_GET(opts, handle, 0); 817 priority = OPTS_GET(opts, priority, 0); 818 prog_fd = OPTS_GET(opts, prog_fd, 0); 819 prog_id = OPTS_GET(opts, prog_id, 0); 820 flags = OPTS_GET(opts, flags, 0); 821 822 if (ifindex <= 0 || flags || prog_fd || prog_id || 823 !handle || !priority) 824 return libbpf_err(-EINVAL); 825 if (priority > UINT16_MAX) 826 return libbpf_err(-EINVAL); 827 828 protocol = ETH_P_ALL; 829 830 memset(&req, 0, sizeof(req)); 831 req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg)); 832 req.nh.nlmsg_flags = NLM_F_REQUEST; 833 req.nh.nlmsg_type = RTM_GETTFILTER; 834 req.tc.tcm_family = AF_UNSPEC; 835 req.tc.tcm_ifindex = ifindex; 836 req.tc.tcm_handle = handle; 837 req.tc.tcm_info = TC_H_MAKE(priority << 16, htons(protocol)); 838 839 ret = tc_get_tcm_parent(attach_point, &parent); 840 if (ret < 0) 841 return libbpf_err(ret); 842 req.tc.tcm_parent = parent; 843 844 ret = nlattr_add(&req, TCA_KIND, "bpf", sizeof("bpf")); 845 if (ret < 0) 846 return libbpf_err(ret); 847 848 info.opts = opts; 849 850 ret = libbpf_netlink_send_recv(&req, get_tc_info, NULL, &info); 851 if (ret < 0) 852 return libbpf_err(ret); 853 if (!info.processed) 854 return libbpf_err(-ENOENT); 855 return ret; 856 } 857