1 // SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) 2 // Copyright (C) 2018 Facebook 3 4 #define _GNU_SOURCE 5 #include <errno.h> 6 #include <fcntl.h> 7 #include <stdlib.h> 8 #include <string.h> 9 #include <time.h> 10 #include <unistd.h> 11 #include <bpf/bpf.h> 12 #include <bpf/libbpf.h> 13 #include <net/if.h> 14 #include <linux/rtnetlink.h> 15 #include <linux/socket.h> 16 #include <linux/tc_act/tc_bpf.h> 17 #include <sys/socket.h> 18 #include <sys/stat.h> 19 #include <sys/types.h> 20 21 #include "bpf/nlattr.h" 22 #include "main.h" 23 #include "netlink_dumper.h" 24 25 #ifndef SOL_NETLINK 26 #define SOL_NETLINK 270 27 #endif 28 29 struct ip_devname_ifindex { 30 char devname[64]; 31 int ifindex; 32 }; 33 34 struct bpf_netdev_t { 35 struct ip_devname_ifindex *devices; 36 int used_len; 37 int array_len; 38 int filter_idx; 39 }; 40 41 struct tc_kind_handle { 42 char kind[64]; 43 int handle; 44 }; 45 46 struct bpf_tcinfo_t { 47 struct tc_kind_handle *handle_array; 48 int used_len; 49 int array_len; 50 bool is_qdisc; 51 }; 52 53 struct bpf_filter_t { 54 const char *kind; 55 const char *devname; 56 int ifindex; 57 }; 58 59 struct bpf_attach_info { 60 __u32 flow_dissector_id; 61 }; 62 63 enum net_attach_type { 64 NET_ATTACH_TYPE_XDP, 65 NET_ATTACH_TYPE_XDP_GENERIC, 66 NET_ATTACH_TYPE_XDP_DRIVER, 67 NET_ATTACH_TYPE_XDP_OFFLOAD, 68 }; 69 70 static const char * const attach_type_strings[] = { 71 [NET_ATTACH_TYPE_XDP] = "xdp", 72 [NET_ATTACH_TYPE_XDP_GENERIC] = "xdpgeneric", 73 [NET_ATTACH_TYPE_XDP_DRIVER] = "xdpdrv", 74 [NET_ATTACH_TYPE_XDP_OFFLOAD] = "xdpoffload", 75 }; 76 77 const size_t net_attach_type_size = ARRAY_SIZE(attach_type_strings); 78 79 static enum net_attach_type parse_attach_type(const char *str) 80 { 81 enum net_attach_type type; 82 83 for (type = 0; type < net_attach_type_size; type++) { 84 if (attach_type_strings[type] && 85 is_prefix(str, attach_type_strings[type])) 86 return type; 87 } 88 89 return net_attach_type_size; 90 } 91 92 typedef int (*dump_nlmsg_t)(void *cookie, void *msg, struct nlattr **tb); 93 94 typedef int (*__dump_nlmsg_t)(struct nlmsghdr *nlmsg, dump_nlmsg_t, void *cookie); 95 96 static int netlink_open(__u32 *nl_pid) 97 { 98 struct sockaddr_nl sa; 99 socklen_t addrlen; 100 int one = 1, ret; 101 int sock; 102 103 memset(&sa, 0, sizeof(sa)); 104 sa.nl_family = AF_NETLINK; 105 106 sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE); 107 if (sock < 0) 108 return -errno; 109 110 if (setsockopt(sock, SOL_NETLINK, NETLINK_EXT_ACK, 111 &one, sizeof(one)) < 0) { 112 p_err("Netlink error reporting not supported"); 113 } 114 115 if (bind(sock, (struct sockaddr *)&sa, sizeof(sa)) < 0) { 116 ret = -errno; 117 goto cleanup; 118 } 119 120 addrlen = sizeof(sa); 121 if (getsockname(sock, (struct sockaddr *)&sa, &addrlen) < 0) { 122 ret = -errno; 123 goto cleanup; 124 } 125 126 if (addrlen != sizeof(sa)) { 127 ret = -LIBBPF_ERRNO__INTERNAL; 128 goto cleanup; 129 } 130 131 *nl_pid = sa.nl_pid; 132 return sock; 133 134 cleanup: 135 close(sock); 136 return ret; 137 } 138 139 static int netlink_recv(int sock, __u32 nl_pid, __u32 seq, 140 __dump_nlmsg_t _fn, dump_nlmsg_t fn, 141 void *cookie) 142 { 143 bool multipart = true; 144 struct nlmsgerr *err; 145 struct nlmsghdr *nh; 146 char buf[4096]; 147 int len, ret; 148 149 while (multipart) { 150 multipart = false; 151 len = recv(sock, buf, sizeof(buf), 0); 152 if (len < 0) { 153 ret = -errno; 154 goto done; 155 } 156 157 if (len == 0) 158 break; 159 160 for (nh = (struct nlmsghdr *)buf; NLMSG_OK(nh, (unsigned int)len); 161 nh = NLMSG_NEXT(nh, len)) { 162 if (nh->nlmsg_pid != nl_pid) { 163 ret = -LIBBPF_ERRNO__WRNGPID; 164 goto done; 165 } 166 if (nh->nlmsg_seq != seq) { 167 ret = -LIBBPF_ERRNO__INVSEQ; 168 goto done; 169 } 170 if (nh->nlmsg_flags & NLM_F_MULTI) 171 multipart = true; 172 switch (nh->nlmsg_type) { 173 case NLMSG_ERROR: 174 err = (struct nlmsgerr *)NLMSG_DATA(nh); 175 if (!err->error) 176 continue; 177 ret = err->error; 178 libbpf_nla_dump_errormsg(nh); 179 goto done; 180 case NLMSG_DONE: 181 return 0; 182 default: 183 break; 184 } 185 if (_fn) { 186 ret = _fn(nh, fn, cookie); 187 if (ret) 188 return ret; 189 } 190 } 191 } 192 ret = 0; 193 done: 194 return ret; 195 } 196 197 static int __dump_class_nlmsg(struct nlmsghdr *nlh, 198 dump_nlmsg_t dump_class_nlmsg, 199 void *cookie) 200 { 201 struct nlattr *tb[TCA_MAX + 1], *attr; 202 struct tcmsg *t = NLMSG_DATA(nlh); 203 int len; 204 205 len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*t)); 206 attr = (struct nlattr *) ((void *) t + NLMSG_ALIGN(sizeof(*t))); 207 if (libbpf_nla_parse(tb, TCA_MAX, attr, len, NULL) != 0) 208 return -LIBBPF_ERRNO__NLPARSE; 209 210 return dump_class_nlmsg(cookie, t, tb); 211 } 212 213 static int netlink_get_class(int sock, unsigned int nl_pid, int ifindex, 214 dump_nlmsg_t dump_class_nlmsg, void *cookie) 215 { 216 struct { 217 struct nlmsghdr nlh; 218 struct tcmsg t; 219 } req = { 220 .nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg)), 221 .nlh.nlmsg_type = RTM_GETTCLASS, 222 .nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST, 223 .t.tcm_family = AF_UNSPEC, 224 .t.tcm_ifindex = ifindex, 225 }; 226 int seq = time(NULL); 227 228 req.nlh.nlmsg_seq = seq; 229 if (send(sock, &req, req.nlh.nlmsg_len, 0) < 0) 230 return -errno; 231 232 return netlink_recv(sock, nl_pid, seq, __dump_class_nlmsg, 233 dump_class_nlmsg, cookie); 234 } 235 236 static int __dump_qdisc_nlmsg(struct nlmsghdr *nlh, 237 dump_nlmsg_t dump_qdisc_nlmsg, 238 void *cookie) 239 { 240 struct nlattr *tb[TCA_MAX + 1], *attr; 241 struct tcmsg *t = NLMSG_DATA(nlh); 242 int len; 243 244 len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*t)); 245 attr = (struct nlattr *) ((void *) t + NLMSG_ALIGN(sizeof(*t))); 246 if (libbpf_nla_parse(tb, TCA_MAX, attr, len, NULL) != 0) 247 return -LIBBPF_ERRNO__NLPARSE; 248 249 return dump_qdisc_nlmsg(cookie, t, tb); 250 } 251 252 static int netlink_get_qdisc(int sock, unsigned int nl_pid, int ifindex, 253 dump_nlmsg_t dump_qdisc_nlmsg, void *cookie) 254 { 255 struct { 256 struct nlmsghdr nlh; 257 struct tcmsg t; 258 } req = { 259 .nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg)), 260 .nlh.nlmsg_type = RTM_GETQDISC, 261 .nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST, 262 .t.tcm_family = AF_UNSPEC, 263 .t.tcm_ifindex = ifindex, 264 }; 265 int seq = time(NULL); 266 267 req.nlh.nlmsg_seq = seq; 268 if (send(sock, &req, req.nlh.nlmsg_len, 0) < 0) 269 return -errno; 270 271 return netlink_recv(sock, nl_pid, seq, __dump_qdisc_nlmsg, 272 dump_qdisc_nlmsg, cookie); 273 } 274 275 static int __dump_filter_nlmsg(struct nlmsghdr *nlh, 276 dump_nlmsg_t dump_filter_nlmsg, 277 void *cookie) 278 { 279 struct nlattr *tb[TCA_MAX + 1], *attr; 280 struct tcmsg *t = NLMSG_DATA(nlh); 281 int len; 282 283 len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*t)); 284 attr = (struct nlattr *) ((void *) t + NLMSG_ALIGN(sizeof(*t))); 285 if (libbpf_nla_parse(tb, TCA_MAX, attr, len, NULL) != 0) 286 return -LIBBPF_ERRNO__NLPARSE; 287 288 return dump_filter_nlmsg(cookie, t, tb); 289 } 290 291 static int netlink_get_filter(int sock, unsigned int nl_pid, int ifindex, int handle, 292 dump_nlmsg_t dump_filter_nlmsg, void *cookie) 293 { 294 struct { 295 struct nlmsghdr nlh; 296 struct tcmsg t; 297 } req = { 298 .nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg)), 299 .nlh.nlmsg_type = RTM_GETTFILTER, 300 .nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST, 301 .t.tcm_family = AF_UNSPEC, 302 .t.tcm_ifindex = ifindex, 303 .t.tcm_parent = handle, 304 }; 305 int seq = time(NULL); 306 307 req.nlh.nlmsg_seq = seq; 308 if (send(sock, &req, req.nlh.nlmsg_len, 0) < 0) 309 return -errno; 310 311 return netlink_recv(sock, nl_pid, seq, __dump_filter_nlmsg, 312 dump_filter_nlmsg, cookie); 313 } 314 315 static int __dump_link_nlmsg(struct nlmsghdr *nlh, 316 dump_nlmsg_t dump_link_nlmsg, void *cookie) 317 { 318 struct nlattr *tb[IFLA_MAX + 1], *attr; 319 struct ifinfomsg *ifi = NLMSG_DATA(nlh); 320 int len; 321 322 len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*ifi)); 323 attr = (struct nlattr *) ((void *) ifi + NLMSG_ALIGN(sizeof(*ifi))); 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 netlink_get_link(int sock, unsigned int nl_pid, 331 dump_nlmsg_t dump_link_nlmsg, void *cookie) 332 { 333 struct { 334 struct nlmsghdr nlh; 335 struct ifinfomsg ifm; 336 } req = { 337 .nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg)), 338 .nlh.nlmsg_type = RTM_GETLINK, 339 .nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST, 340 .ifm.ifi_family = AF_PACKET, 341 }; 342 int seq = time(NULL); 343 344 req.nlh.nlmsg_seq = seq; 345 if (send(sock, &req, req.nlh.nlmsg_len, 0) < 0) 346 return -errno; 347 348 return netlink_recv(sock, nl_pid, seq, __dump_link_nlmsg, 349 dump_link_nlmsg, cookie); 350 } 351 352 static int dump_link_nlmsg(void *cookie, void *msg, struct nlattr **tb) 353 { 354 struct bpf_netdev_t *netinfo = cookie; 355 struct ifinfomsg *ifinfo = msg; 356 357 if (netinfo->filter_idx > 0 && netinfo->filter_idx != ifinfo->ifi_index) 358 return 0; 359 360 if (netinfo->used_len == netinfo->array_len) { 361 netinfo->devices = realloc(netinfo->devices, 362 (netinfo->array_len + 16) * 363 sizeof(struct ip_devname_ifindex)); 364 if (!netinfo->devices) 365 return -ENOMEM; 366 367 netinfo->array_len += 16; 368 } 369 netinfo->devices[netinfo->used_len].ifindex = ifinfo->ifi_index; 370 snprintf(netinfo->devices[netinfo->used_len].devname, 371 sizeof(netinfo->devices[netinfo->used_len].devname), 372 "%s", 373 tb[IFLA_IFNAME] 374 ? libbpf_nla_getattr_str(tb[IFLA_IFNAME]) 375 : ""); 376 netinfo->used_len++; 377 378 return do_xdp_dump(ifinfo, tb); 379 } 380 381 static int dump_class_qdisc_nlmsg(void *cookie, void *msg, struct nlattr **tb) 382 { 383 struct bpf_tcinfo_t *tcinfo = cookie; 384 struct tcmsg *info = msg; 385 386 if (tcinfo->is_qdisc) { 387 /* skip clsact qdisc */ 388 if (tb[TCA_KIND] && 389 strcmp(libbpf_nla_data(tb[TCA_KIND]), "clsact") == 0) 390 return 0; 391 if (info->tcm_handle == 0) 392 return 0; 393 } 394 395 if (tcinfo->used_len == tcinfo->array_len) { 396 tcinfo->handle_array = realloc(tcinfo->handle_array, 397 (tcinfo->array_len + 16) * sizeof(struct tc_kind_handle)); 398 if (!tcinfo->handle_array) 399 return -ENOMEM; 400 401 tcinfo->array_len += 16; 402 } 403 tcinfo->handle_array[tcinfo->used_len].handle = info->tcm_handle; 404 snprintf(tcinfo->handle_array[tcinfo->used_len].kind, 405 sizeof(tcinfo->handle_array[tcinfo->used_len].kind), 406 "%s", 407 tb[TCA_KIND] 408 ? libbpf_nla_getattr_str(tb[TCA_KIND]) 409 : "unknown"); 410 tcinfo->used_len++; 411 412 return 0; 413 } 414 415 static int dump_filter_nlmsg(void *cookie, void *msg, struct nlattr **tb) 416 { 417 const struct bpf_filter_t *filter_info = cookie; 418 419 return do_filter_dump((struct tcmsg *)msg, tb, filter_info->kind, 420 filter_info->devname, filter_info->ifindex); 421 } 422 423 static int show_dev_tc_bpf(int sock, unsigned int nl_pid, 424 struct ip_devname_ifindex *dev) 425 { 426 struct bpf_filter_t filter_info; 427 struct bpf_tcinfo_t tcinfo; 428 int i, handle, ret = 0; 429 430 tcinfo.handle_array = NULL; 431 tcinfo.used_len = 0; 432 tcinfo.array_len = 0; 433 434 tcinfo.is_qdisc = false; 435 ret = netlink_get_class(sock, nl_pid, dev->ifindex, 436 dump_class_qdisc_nlmsg, &tcinfo); 437 if (ret) 438 goto out; 439 440 tcinfo.is_qdisc = true; 441 ret = netlink_get_qdisc(sock, nl_pid, dev->ifindex, 442 dump_class_qdisc_nlmsg, &tcinfo); 443 if (ret) 444 goto out; 445 446 filter_info.devname = dev->devname; 447 filter_info.ifindex = dev->ifindex; 448 for (i = 0; i < tcinfo.used_len; i++) { 449 filter_info.kind = tcinfo.handle_array[i].kind; 450 ret = netlink_get_filter(sock, nl_pid, dev->ifindex, 451 tcinfo.handle_array[i].handle, 452 dump_filter_nlmsg, &filter_info); 453 if (ret) 454 goto out; 455 } 456 457 /* root, ingress and egress handle */ 458 handle = TC_H_ROOT; 459 filter_info.kind = "root"; 460 ret = netlink_get_filter(sock, nl_pid, dev->ifindex, handle, 461 dump_filter_nlmsg, &filter_info); 462 if (ret) 463 goto out; 464 465 handle = TC_H_MAKE(TC_H_CLSACT, TC_H_MIN_INGRESS); 466 filter_info.kind = "clsact/ingress"; 467 ret = netlink_get_filter(sock, nl_pid, dev->ifindex, handle, 468 dump_filter_nlmsg, &filter_info); 469 if (ret) 470 goto out; 471 472 handle = TC_H_MAKE(TC_H_CLSACT, TC_H_MIN_EGRESS); 473 filter_info.kind = "clsact/egress"; 474 ret = netlink_get_filter(sock, nl_pid, dev->ifindex, handle, 475 dump_filter_nlmsg, &filter_info); 476 if (ret) 477 goto out; 478 479 out: 480 free(tcinfo.handle_array); 481 return 0; 482 } 483 484 static int query_flow_dissector(struct bpf_attach_info *attach_info) 485 { 486 __u32 attach_flags; 487 __u32 prog_ids[1]; 488 __u32 prog_cnt; 489 int err; 490 int fd; 491 492 fd = open("/proc/self/ns/net", O_RDONLY); 493 if (fd < 0) { 494 p_err("can't open /proc/self/ns/net: %s", 495 strerror(errno)); 496 return -1; 497 } 498 prog_cnt = ARRAY_SIZE(prog_ids); 499 err = bpf_prog_query(fd, BPF_FLOW_DISSECTOR, 0, 500 &attach_flags, prog_ids, &prog_cnt); 501 close(fd); 502 if (err) { 503 if (errno == EINVAL) { 504 /* Older kernel's don't support querying 505 * flow dissector programs. 506 */ 507 errno = 0; 508 return 0; 509 } 510 p_err("can't query prog: %s", strerror(errno)); 511 return -1; 512 } 513 514 if (prog_cnt == 1) 515 attach_info->flow_dissector_id = prog_ids[0]; 516 517 return 0; 518 } 519 520 static int net_parse_dev(int *argc, char ***argv) 521 { 522 int ifindex; 523 524 if (is_prefix(**argv, "dev")) { 525 NEXT_ARGP(); 526 527 ifindex = if_nametoindex(**argv); 528 if (!ifindex) 529 p_err("invalid devname %s", **argv); 530 531 NEXT_ARGP(); 532 } else { 533 p_err("expected 'dev', got: '%s'?", **argv); 534 return -1; 535 } 536 537 return ifindex; 538 } 539 540 static int do_attach_detach_xdp(int progfd, enum net_attach_type attach_type, 541 int ifindex, bool overwrite) 542 { 543 __u32 flags = 0; 544 545 if (!overwrite) 546 flags = XDP_FLAGS_UPDATE_IF_NOEXIST; 547 if (attach_type == NET_ATTACH_TYPE_XDP_GENERIC) 548 flags |= XDP_FLAGS_SKB_MODE; 549 if (attach_type == NET_ATTACH_TYPE_XDP_DRIVER) 550 flags |= XDP_FLAGS_DRV_MODE; 551 if (attach_type == NET_ATTACH_TYPE_XDP_OFFLOAD) 552 flags |= XDP_FLAGS_HW_MODE; 553 554 return bpf_xdp_attach(ifindex, progfd, flags, NULL); 555 } 556 557 static int do_attach(int argc, char **argv) 558 { 559 enum net_attach_type attach_type; 560 int progfd, ifindex, err = 0; 561 bool overwrite = false; 562 563 /* parse attach args */ 564 if (!REQ_ARGS(5)) 565 return -EINVAL; 566 567 attach_type = parse_attach_type(*argv); 568 if (attach_type == net_attach_type_size) { 569 p_err("invalid net attach/detach type: %s", *argv); 570 return -EINVAL; 571 } 572 NEXT_ARG(); 573 574 progfd = prog_parse_fd(&argc, &argv); 575 if (progfd < 0) 576 return -EINVAL; 577 578 ifindex = net_parse_dev(&argc, &argv); 579 if (ifindex < 1) { 580 err = -EINVAL; 581 goto cleanup; 582 } 583 584 if (argc) { 585 if (is_prefix(*argv, "overwrite")) { 586 overwrite = true; 587 } else { 588 p_err("expected 'overwrite', got: '%s'?", *argv); 589 err = -EINVAL; 590 goto cleanup; 591 } 592 } 593 594 /* attach xdp prog */ 595 if (is_prefix("xdp", attach_type_strings[attach_type])) 596 err = do_attach_detach_xdp(progfd, attach_type, ifindex, 597 overwrite); 598 if (err) { 599 p_err("interface %s attach failed: %s", 600 attach_type_strings[attach_type], strerror(-err)); 601 goto cleanup; 602 } 603 604 if (json_output) 605 jsonw_null(json_wtr); 606 cleanup: 607 close(progfd); 608 return err; 609 } 610 611 static int do_detach(int argc, char **argv) 612 { 613 enum net_attach_type attach_type; 614 int progfd, ifindex, err = 0; 615 616 /* parse detach args */ 617 if (!REQ_ARGS(3)) 618 return -EINVAL; 619 620 attach_type = parse_attach_type(*argv); 621 if (attach_type == net_attach_type_size) { 622 p_err("invalid net attach/detach type: %s", *argv); 623 return -EINVAL; 624 } 625 NEXT_ARG(); 626 627 ifindex = net_parse_dev(&argc, &argv); 628 if (ifindex < 1) 629 return -EINVAL; 630 631 /* detach xdp prog */ 632 progfd = -1; 633 if (is_prefix("xdp", attach_type_strings[attach_type])) 634 err = do_attach_detach_xdp(progfd, attach_type, ifindex, NULL); 635 636 if (err < 0) { 637 p_err("interface %s detach failed: %s", 638 attach_type_strings[attach_type], strerror(-err)); 639 return err; 640 } 641 642 if (json_output) 643 jsonw_null(json_wtr); 644 645 return 0; 646 } 647 648 static int do_show(int argc, char **argv) 649 { 650 struct bpf_attach_info attach_info = {}; 651 int i, sock, ret, filter_idx = -1; 652 struct bpf_netdev_t dev_array; 653 unsigned int nl_pid = 0; 654 char err_buf[256]; 655 656 if (argc == 2) { 657 filter_idx = net_parse_dev(&argc, &argv); 658 if (filter_idx < 1) 659 return -1; 660 } else if (argc != 0) { 661 usage(); 662 } 663 664 ret = query_flow_dissector(&attach_info); 665 if (ret) 666 return -1; 667 668 sock = netlink_open(&nl_pid); 669 if (sock < 0) { 670 fprintf(stderr, "failed to open netlink sock\n"); 671 return -1; 672 } 673 674 dev_array.devices = NULL; 675 dev_array.used_len = 0; 676 dev_array.array_len = 0; 677 dev_array.filter_idx = filter_idx; 678 679 if (json_output) 680 jsonw_start_array(json_wtr); 681 NET_START_OBJECT; 682 NET_START_ARRAY("xdp", "%s:\n"); 683 ret = netlink_get_link(sock, nl_pid, dump_link_nlmsg, &dev_array); 684 NET_END_ARRAY("\n"); 685 686 if (!ret) { 687 NET_START_ARRAY("tc", "%s:\n"); 688 for (i = 0; i < dev_array.used_len; i++) { 689 ret = show_dev_tc_bpf(sock, nl_pid, 690 &dev_array.devices[i]); 691 if (ret) 692 break; 693 } 694 NET_END_ARRAY("\n"); 695 } 696 697 NET_START_ARRAY("flow_dissector", "%s:\n"); 698 if (attach_info.flow_dissector_id > 0) 699 NET_DUMP_UINT("id", "id %u", attach_info.flow_dissector_id); 700 NET_END_ARRAY("\n"); 701 702 NET_END_OBJECT; 703 if (json_output) 704 jsonw_end_array(json_wtr); 705 706 if (ret) { 707 if (json_output) 708 jsonw_null(json_wtr); 709 libbpf_strerror(ret, err_buf, sizeof(err_buf)); 710 fprintf(stderr, "Error: %s\n", err_buf); 711 } 712 free(dev_array.devices); 713 close(sock); 714 return ret; 715 } 716 717 static int do_help(int argc, char **argv) 718 { 719 if (json_output) { 720 jsonw_null(json_wtr); 721 return 0; 722 } 723 724 fprintf(stderr, 725 "Usage: %1$s %2$s { show | list } [dev <devname>]\n" 726 " %1$s %2$s attach ATTACH_TYPE PROG dev <devname> [ overwrite ]\n" 727 " %1$s %2$s detach ATTACH_TYPE dev <devname>\n" 728 " %1$s %2$s help\n" 729 "\n" 730 " " HELP_SPEC_PROGRAM "\n" 731 " ATTACH_TYPE := { xdp | xdpgeneric | xdpdrv | xdpoffload }\n" 732 " " HELP_SPEC_OPTIONS " }\n" 733 "\n" 734 "Note: Only xdp and tc attachments are supported now.\n" 735 " For progs attached to cgroups, use \"bpftool cgroup\"\n" 736 " to dump program attachments. For program types\n" 737 " sk_{filter,skb,msg,reuseport} and lwt/seg6, please\n" 738 " consult iproute2.\n" 739 "", 740 bin_name, argv[-2]); 741 742 return 0; 743 } 744 745 static const struct cmd cmds[] = { 746 { "show", do_show }, 747 { "list", do_show }, 748 { "attach", do_attach }, 749 { "detach", do_detach }, 750 { "help", do_help }, 751 { 0 } 752 }; 753 754 int do_net(int argc, char **argv) 755 { 756 return cmd_select(cmds, argc, argv, do_help); 757 } 758