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/if.h> 15 #include <linux/rtnetlink.h> 16 #include <linux/socket.h> 17 #include <linux/tc_act/tc_bpf.h> 18 #include <sys/socket.h> 19 #include <sys/stat.h> 20 #include <sys/types.h> 21 22 #include "bpf/nlattr.h" 23 #include "main.h" 24 #include "netlink_dumper.h" 25 26 #ifndef SOL_NETLINK 27 #define SOL_NETLINK 270 28 #endif 29 30 struct ip_devname_ifindex { 31 char devname[64]; 32 int ifindex; 33 }; 34 35 struct bpf_netdev_t { 36 struct ip_devname_ifindex *devices; 37 int used_len; 38 int array_len; 39 int filter_idx; 40 }; 41 42 struct tc_kind_handle { 43 char kind[64]; 44 int handle; 45 }; 46 47 struct bpf_tcinfo_t { 48 struct tc_kind_handle *handle_array; 49 int used_len; 50 int array_len; 51 bool is_qdisc; 52 }; 53 54 struct bpf_filter_t { 55 const char *kind; 56 const char *devname; 57 int ifindex; 58 }; 59 60 struct bpf_attach_info { 61 __u32 flow_dissector_id; 62 }; 63 64 enum net_attach_type { 65 NET_ATTACH_TYPE_XDP, 66 NET_ATTACH_TYPE_XDP_GENERIC, 67 NET_ATTACH_TYPE_XDP_DRIVER, 68 NET_ATTACH_TYPE_XDP_OFFLOAD, 69 }; 70 71 static const char * const attach_type_strings[] = { 72 [NET_ATTACH_TYPE_XDP] = "xdp", 73 [NET_ATTACH_TYPE_XDP_GENERIC] = "xdpgeneric", 74 [NET_ATTACH_TYPE_XDP_DRIVER] = "xdpdrv", 75 [NET_ATTACH_TYPE_XDP_OFFLOAD] = "xdpoffload", 76 }; 77 78 const size_t net_attach_type_size = ARRAY_SIZE(attach_type_strings); 79 80 static enum net_attach_type parse_attach_type(const char *str) 81 { 82 enum net_attach_type type; 83 84 for (type = 0; type < net_attach_type_size; type++) { 85 if (attach_type_strings[type] && 86 is_prefix(str, attach_type_strings[type])) 87 return type; 88 } 89 90 return net_attach_type_size; 91 } 92 93 typedef int (*dump_nlmsg_t)(void *cookie, void *msg, struct nlattr **tb); 94 95 typedef int (*__dump_nlmsg_t)(struct nlmsghdr *nlmsg, dump_nlmsg_t, void *cookie); 96 97 static int netlink_open(__u32 *nl_pid) 98 { 99 struct sockaddr_nl sa; 100 socklen_t addrlen; 101 int one = 1, ret; 102 int sock; 103 104 memset(&sa, 0, sizeof(sa)); 105 sa.nl_family = AF_NETLINK; 106 107 sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE); 108 if (sock < 0) 109 return -errno; 110 111 if (setsockopt(sock, SOL_NETLINK, NETLINK_EXT_ACK, 112 &one, sizeof(one)) < 0) { 113 p_err("Netlink error reporting not supported"); 114 } 115 116 if (bind(sock, (struct sockaddr *)&sa, sizeof(sa)) < 0) { 117 ret = -errno; 118 goto cleanup; 119 } 120 121 addrlen = sizeof(sa); 122 if (getsockname(sock, (struct sockaddr *)&sa, &addrlen) < 0) { 123 ret = -errno; 124 goto cleanup; 125 } 126 127 if (addrlen != sizeof(sa)) { 128 ret = -LIBBPF_ERRNO__INTERNAL; 129 goto cleanup; 130 } 131 132 *nl_pid = sa.nl_pid; 133 return sock; 134 135 cleanup: 136 close(sock); 137 return ret; 138 } 139 140 static int netlink_recv(int sock, __u32 nl_pid, __u32 seq, 141 __dump_nlmsg_t _fn, dump_nlmsg_t fn, 142 void *cookie) 143 { 144 bool multipart = true; 145 struct nlmsgerr *err; 146 struct nlmsghdr *nh; 147 char buf[4096]; 148 int len, ret; 149 150 while (multipart) { 151 multipart = false; 152 len = recv(sock, buf, sizeof(buf), 0); 153 if (len < 0) { 154 ret = -errno; 155 goto done; 156 } 157 158 if (len == 0) 159 break; 160 161 for (nh = (struct nlmsghdr *)buf; NLMSG_OK(nh, len); 162 nh = NLMSG_NEXT(nh, len)) { 163 if (nh->nlmsg_pid != nl_pid) { 164 ret = -LIBBPF_ERRNO__WRNGPID; 165 goto done; 166 } 167 if (nh->nlmsg_seq != seq) { 168 ret = -LIBBPF_ERRNO__INVSEQ; 169 goto done; 170 } 171 if (nh->nlmsg_flags & NLM_F_MULTI) 172 multipart = true; 173 switch (nh->nlmsg_type) { 174 case NLMSG_ERROR: 175 err = (struct nlmsgerr *)NLMSG_DATA(nh); 176 if (!err->error) 177 continue; 178 ret = err->error; 179 libbpf_nla_dump_errormsg(nh); 180 goto done; 181 case NLMSG_DONE: 182 return 0; 183 default: 184 break; 185 } 186 if (_fn) { 187 ret = _fn(nh, fn, cookie); 188 if (ret) 189 return ret; 190 } 191 } 192 } 193 ret = 0; 194 done: 195 return ret; 196 } 197 198 static int __dump_class_nlmsg(struct nlmsghdr *nlh, 199 dump_nlmsg_t dump_class_nlmsg, 200 void *cookie) 201 { 202 struct nlattr *tb[TCA_MAX + 1], *attr; 203 struct tcmsg *t = NLMSG_DATA(nlh); 204 int len; 205 206 len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*t)); 207 attr = (struct nlattr *) ((void *) t + NLMSG_ALIGN(sizeof(*t))); 208 if (libbpf_nla_parse(tb, TCA_MAX, attr, len, NULL) != 0) 209 return -LIBBPF_ERRNO__NLPARSE; 210 211 return dump_class_nlmsg(cookie, t, tb); 212 } 213 214 static int netlink_get_class(int sock, unsigned int nl_pid, int ifindex, 215 dump_nlmsg_t dump_class_nlmsg, void *cookie) 216 { 217 struct { 218 struct nlmsghdr nlh; 219 struct tcmsg t; 220 } req = { 221 .nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg)), 222 .nlh.nlmsg_type = RTM_GETTCLASS, 223 .nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST, 224 .t.tcm_family = AF_UNSPEC, 225 .t.tcm_ifindex = ifindex, 226 }; 227 int seq = time(NULL); 228 229 req.nlh.nlmsg_seq = seq; 230 if (send(sock, &req, req.nlh.nlmsg_len, 0) < 0) 231 return -errno; 232 233 return netlink_recv(sock, nl_pid, seq, __dump_class_nlmsg, 234 dump_class_nlmsg, cookie); 235 } 236 237 static int __dump_qdisc_nlmsg(struct nlmsghdr *nlh, 238 dump_nlmsg_t dump_qdisc_nlmsg, 239 void *cookie) 240 { 241 struct nlattr *tb[TCA_MAX + 1], *attr; 242 struct tcmsg *t = NLMSG_DATA(nlh); 243 int len; 244 245 len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*t)); 246 attr = (struct nlattr *) ((void *) t + NLMSG_ALIGN(sizeof(*t))); 247 if (libbpf_nla_parse(tb, TCA_MAX, attr, len, NULL) != 0) 248 return -LIBBPF_ERRNO__NLPARSE; 249 250 return dump_qdisc_nlmsg(cookie, t, tb); 251 } 252 253 static int netlink_get_qdisc(int sock, unsigned int nl_pid, int ifindex, 254 dump_nlmsg_t dump_qdisc_nlmsg, void *cookie) 255 { 256 struct { 257 struct nlmsghdr nlh; 258 struct tcmsg t; 259 } req = { 260 .nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg)), 261 .nlh.nlmsg_type = RTM_GETQDISC, 262 .nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST, 263 .t.tcm_family = AF_UNSPEC, 264 .t.tcm_ifindex = ifindex, 265 }; 266 int seq = time(NULL); 267 268 req.nlh.nlmsg_seq = seq; 269 if (send(sock, &req, req.nlh.nlmsg_len, 0) < 0) 270 return -errno; 271 272 return netlink_recv(sock, nl_pid, seq, __dump_qdisc_nlmsg, 273 dump_qdisc_nlmsg, cookie); 274 } 275 276 static int __dump_filter_nlmsg(struct nlmsghdr *nlh, 277 dump_nlmsg_t dump_filter_nlmsg, 278 void *cookie) 279 { 280 struct nlattr *tb[TCA_MAX + 1], *attr; 281 struct tcmsg *t = NLMSG_DATA(nlh); 282 int len; 283 284 len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*t)); 285 attr = (struct nlattr *) ((void *) t + NLMSG_ALIGN(sizeof(*t))); 286 if (libbpf_nla_parse(tb, TCA_MAX, attr, len, NULL) != 0) 287 return -LIBBPF_ERRNO__NLPARSE; 288 289 return dump_filter_nlmsg(cookie, t, tb); 290 } 291 292 static int netlink_get_filter(int sock, unsigned int nl_pid, int ifindex, int handle, 293 dump_nlmsg_t dump_filter_nlmsg, void *cookie) 294 { 295 struct { 296 struct nlmsghdr nlh; 297 struct tcmsg t; 298 } req = { 299 .nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg)), 300 .nlh.nlmsg_type = RTM_GETTFILTER, 301 .nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST, 302 .t.tcm_family = AF_UNSPEC, 303 .t.tcm_ifindex = ifindex, 304 .t.tcm_parent = handle, 305 }; 306 int seq = time(NULL); 307 308 req.nlh.nlmsg_seq = seq; 309 if (send(sock, &req, req.nlh.nlmsg_len, 0) < 0) 310 return -errno; 311 312 return netlink_recv(sock, nl_pid, seq, __dump_filter_nlmsg, 313 dump_filter_nlmsg, cookie); 314 } 315 316 static int __dump_link_nlmsg(struct nlmsghdr *nlh, 317 dump_nlmsg_t dump_link_nlmsg, void *cookie) 318 { 319 struct nlattr *tb[IFLA_MAX + 1], *attr; 320 struct ifinfomsg *ifi = NLMSG_DATA(nlh); 321 int len; 322 323 len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*ifi)); 324 attr = (struct nlattr *) ((void *) ifi + NLMSG_ALIGN(sizeof(*ifi))); 325 if (libbpf_nla_parse(tb, IFLA_MAX, attr, len, NULL) != 0) 326 return -LIBBPF_ERRNO__NLPARSE; 327 328 return dump_link_nlmsg(cookie, ifi, tb); 329 } 330 331 static int netlink_get_link(int sock, unsigned int nl_pid, 332 dump_nlmsg_t dump_link_nlmsg, void *cookie) 333 { 334 struct { 335 struct nlmsghdr nlh; 336 struct ifinfomsg ifm; 337 } req = { 338 .nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg)), 339 .nlh.nlmsg_type = RTM_GETLINK, 340 .nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST, 341 .ifm.ifi_family = AF_PACKET, 342 }; 343 int seq = time(NULL); 344 345 req.nlh.nlmsg_seq = seq; 346 if (send(sock, &req, req.nlh.nlmsg_len, 0) < 0) 347 return -errno; 348 349 return netlink_recv(sock, nl_pid, seq, __dump_link_nlmsg, 350 dump_link_nlmsg, cookie); 351 } 352 353 static int dump_link_nlmsg(void *cookie, void *msg, struct nlattr **tb) 354 { 355 struct bpf_netdev_t *netinfo = cookie; 356 struct ifinfomsg *ifinfo = msg; 357 358 if (netinfo->filter_idx > 0 && netinfo->filter_idx != ifinfo->ifi_index) 359 return 0; 360 361 if (netinfo->used_len == netinfo->array_len) { 362 netinfo->devices = realloc(netinfo->devices, 363 (netinfo->array_len + 16) * 364 sizeof(struct ip_devname_ifindex)); 365 if (!netinfo->devices) 366 return -ENOMEM; 367 368 netinfo->array_len += 16; 369 } 370 netinfo->devices[netinfo->used_len].ifindex = ifinfo->ifi_index; 371 snprintf(netinfo->devices[netinfo->used_len].devname, 372 sizeof(netinfo->devices[netinfo->used_len].devname), 373 "%s", 374 tb[IFLA_IFNAME] 375 ? libbpf_nla_getattr_str(tb[IFLA_IFNAME]) 376 : ""); 377 netinfo->used_len++; 378 379 return do_xdp_dump(ifinfo, tb); 380 } 381 382 static int dump_class_qdisc_nlmsg(void *cookie, void *msg, struct nlattr **tb) 383 { 384 struct bpf_tcinfo_t *tcinfo = cookie; 385 struct tcmsg *info = msg; 386 387 if (tcinfo->is_qdisc) { 388 /* skip clsact qdisc */ 389 if (tb[TCA_KIND] && 390 strcmp(libbpf_nla_data(tb[TCA_KIND]), "clsact") == 0) 391 return 0; 392 if (info->tcm_handle == 0) 393 return 0; 394 } 395 396 if (tcinfo->used_len == tcinfo->array_len) { 397 tcinfo->handle_array = realloc(tcinfo->handle_array, 398 (tcinfo->array_len + 16) * sizeof(struct tc_kind_handle)); 399 if (!tcinfo->handle_array) 400 return -ENOMEM; 401 402 tcinfo->array_len += 16; 403 } 404 tcinfo->handle_array[tcinfo->used_len].handle = info->tcm_handle; 405 snprintf(tcinfo->handle_array[tcinfo->used_len].kind, 406 sizeof(tcinfo->handle_array[tcinfo->used_len].kind), 407 "%s", 408 tb[TCA_KIND] 409 ? libbpf_nla_getattr_str(tb[TCA_KIND]) 410 : "unknown"); 411 tcinfo->used_len++; 412 413 return 0; 414 } 415 416 static int dump_filter_nlmsg(void *cookie, void *msg, struct nlattr **tb) 417 { 418 const struct bpf_filter_t *filter_info = cookie; 419 420 return do_filter_dump((struct tcmsg *)msg, tb, filter_info->kind, 421 filter_info->devname, filter_info->ifindex); 422 } 423 424 static int show_dev_tc_bpf(int sock, unsigned int nl_pid, 425 struct ip_devname_ifindex *dev) 426 { 427 struct bpf_filter_t filter_info; 428 struct bpf_tcinfo_t tcinfo; 429 int i, handle, ret = 0; 430 431 tcinfo.handle_array = NULL; 432 tcinfo.used_len = 0; 433 tcinfo.array_len = 0; 434 435 tcinfo.is_qdisc = false; 436 ret = netlink_get_class(sock, nl_pid, dev->ifindex, 437 dump_class_qdisc_nlmsg, &tcinfo); 438 if (ret) 439 goto out; 440 441 tcinfo.is_qdisc = true; 442 ret = netlink_get_qdisc(sock, nl_pid, dev->ifindex, 443 dump_class_qdisc_nlmsg, &tcinfo); 444 if (ret) 445 goto out; 446 447 filter_info.devname = dev->devname; 448 filter_info.ifindex = dev->ifindex; 449 for (i = 0; i < tcinfo.used_len; i++) { 450 filter_info.kind = tcinfo.handle_array[i].kind; 451 ret = netlink_get_filter(sock, nl_pid, dev->ifindex, 452 tcinfo.handle_array[i].handle, 453 dump_filter_nlmsg, &filter_info); 454 if (ret) 455 goto out; 456 } 457 458 /* root, ingress and egress handle */ 459 handle = TC_H_ROOT; 460 filter_info.kind = "root"; 461 ret = netlink_get_filter(sock, nl_pid, dev->ifindex, handle, 462 dump_filter_nlmsg, &filter_info); 463 if (ret) 464 goto out; 465 466 handle = TC_H_MAKE(TC_H_CLSACT, TC_H_MIN_INGRESS); 467 filter_info.kind = "clsact/ingress"; 468 ret = netlink_get_filter(sock, nl_pid, dev->ifindex, handle, 469 dump_filter_nlmsg, &filter_info); 470 if (ret) 471 goto out; 472 473 handle = TC_H_MAKE(TC_H_CLSACT, TC_H_MIN_EGRESS); 474 filter_info.kind = "clsact/egress"; 475 ret = netlink_get_filter(sock, nl_pid, dev->ifindex, handle, 476 dump_filter_nlmsg, &filter_info); 477 if (ret) 478 goto out; 479 480 out: 481 free(tcinfo.handle_array); 482 return 0; 483 } 484 485 static int query_flow_dissector(struct bpf_attach_info *attach_info) 486 { 487 __u32 attach_flags; 488 __u32 prog_ids[1]; 489 __u32 prog_cnt; 490 int err; 491 int fd; 492 493 fd = open("/proc/self/ns/net", O_RDONLY); 494 if (fd < 0) { 495 p_err("can't open /proc/self/ns/net: %s", 496 strerror(errno)); 497 return -1; 498 } 499 prog_cnt = ARRAY_SIZE(prog_ids); 500 err = bpf_prog_query(fd, BPF_FLOW_DISSECTOR, 0, 501 &attach_flags, prog_ids, &prog_cnt); 502 close(fd); 503 if (err) { 504 if (errno == EINVAL) { 505 /* Older kernel's don't support querying 506 * flow dissector programs. 507 */ 508 errno = 0; 509 return 0; 510 } 511 p_err("can't query prog: %s", strerror(errno)); 512 return -1; 513 } 514 515 if (prog_cnt == 1) 516 attach_info->flow_dissector_id = prog_ids[0]; 517 518 return 0; 519 } 520 521 static int net_parse_dev(int *argc, char ***argv) 522 { 523 int ifindex; 524 525 if (is_prefix(**argv, "dev")) { 526 NEXT_ARGP(); 527 528 ifindex = if_nametoindex(**argv); 529 if (!ifindex) 530 p_err("invalid devname %s", **argv); 531 532 NEXT_ARGP(); 533 } else { 534 p_err("expected 'dev', got: '%s'?", **argv); 535 return -1; 536 } 537 538 return ifindex; 539 } 540 541 static int do_attach_detach_xdp(int progfd, enum net_attach_type attach_type, 542 int ifindex, bool overwrite) 543 { 544 __u32 flags = 0; 545 546 if (!overwrite) 547 flags = XDP_FLAGS_UPDATE_IF_NOEXIST; 548 if (attach_type == NET_ATTACH_TYPE_XDP_GENERIC) 549 flags |= XDP_FLAGS_SKB_MODE; 550 if (attach_type == NET_ATTACH_TYPE_XDP_DRIVER) 551 flags |= XDP_FLAGS_DRV_MODE; 552 if (attach_type == NET_ATTACH_TYPE_XDP_OFFLOAD) 553 flags |= XDP_FLAGS_HW_MODE; 554 555 return bpf_set_link_xdp_fd(ifindex, progfd, flags); 556 } 557 558 static int do_attach(int argc, char **argv) 559 { 560 enum net_attach_type attach_type; 561 int progfd, ifindex, err = 0; 562 bool overwrite = false; 563 564 /* parse attach args */ 565 if (!REQ_ARGS(5)) 566 return -EINVAL; 567 568 attach_type = parse_attach_type(*argv); 569 if (attach_type == net_attach_type_size) { 570 p_err("invalid net attach/detach type: %s", *argv); 571 return -EINVAL; 572 } 573 NEXT_ARG(); 574 575 progfd = prog_parse_fd(&argc, &argv); 576 if (progfd < 0) 577 return -EINVAL; 578 579 ifindex = net_parse_dev(&argc, &argv); 580 if (ifindex < 1) { 581 close(progfd); 582 return -EINVAL; 583 } 584 585 if (argc) { 586 if (is_prefix(*argv, "overwrite")) { 587 overwrite = true; 588 } else { 589 p_err("expected 'overwrite', got: '%s'?", *argv); 590 close(progfd); 591 return -EINVAL; 592 } 593 } 594 595 /* attach xdp prog */ 596 if (is_prefix("xdp", attach_type_strings[attach_type])) 597 err = do_attach_detach_xdp(progfd, attach_type, ifindex, 598 overwrite); 599 600 if (err < 0) { 601 p_err("interface %s attach failed: %s", 602 attach_type_strings[attach_type], strerror(-err)); 603 return err; 604 } 605 606 if (json_output) 607 jsonw_null(json_wtr); 608 609 return 0; 610 } 611 612 static int do_detach(int argc, char **argv) 613 { 614 enum net_attach_type attach_type; 615 int progfd, ifindex, err = 0; 616 617 /* parse detach args */ 618 if (!REQ_ARGS(3)) 619 return -EINVAL; 620 621 attach_type = parse_attach_type(*argv); 622 if (attach_type == net_attach_type_size) { 623 p_err("invalid net attach/detach type: %s", *argv); 624 return -EINVAL; 625 } 626 NEXT_ARG(); 627 628 ifindex = net_parse_dev(&argc, &argv); 629 if (ifindex < 1) 630 return -EINVAL; 631 632 /* detach xdp prog */ 633 progfd = -1; 634 if (is_prefix("xdp", attach_type_strings[attach_type])) 635 err = do_attach_detach_xdp(progfd, attach_type, ifindex, NULL); 636 637 if (err < 0) { 638 p_err("interface %s detach failed: %s", 639 attach_type_strings[attach_type], strerror(-err)); 640 return err; 641 } 642 643 if (json_output) 644 jsonw_null(json_wtr); 645 646 return 0; 647 } 648 649 static int do_show(int argc, char **argv) 650 { 651 struct bpf_attach_info attach_info = {}; 652 int i, sock, ret, filter_idx = -1; 653 struct bpf_netdev_t dev_array; 654 unsigned int nl_pid = 0; 655 char err_buf[256]; 656 657 if (argc == 2) { 658 filter_idx = net_parse_dev(&argc, &argv); 659 if (filter_idx < 1) 660 return -1; 661 } else if (argc != 0) { 662 usage(); 663 } 664 665 ret = query_flow_dissector(&attach_info); 666 if (ret) 667 return -1; 668 669 sock = netlink_open(&nl_pid); 670 if (sock < 0) { 671 fprintf(stderr, "failed to open netlink sock\n"); 672 return -1; 673 } 674 675 dev_array.devices = NULL; 676 dev_array.used_len = 0; 677 dev_array.array_len = 0; 678 dev_array.filter_idx = filter_idx; 679 680 if (json_output) 681 jsonw_start_array(json_wtr); 682 NET_START_OBJECT; 683 NET_START_ARRAY("xdp", "%s:\n"); 684 ret = netlink_get_link(sock, nl_pid, dump_link_nlmsg, &dev_array); 685 NET_END_ARRAY("\n"); 686 687 if (!ret) { 688 NET_START_ARRAY("tc", "%s:\n"); 689 for (i = 0; i < dev_array.used_len; i++) { 690 ret = show_dev_tc_bpf(sock, nl_pid, 691 &dev_array.devices[i]); 692 if (ret) 693 break; 694 } 695 NET_END_ARRAY("\n"); 696 } 697 698 NET_START_ARRAY("flow_dissector", "%s:\n"); 699 if (attach_info.flow_dissector_id > 0) 700 NET_DUMP_UINT("id", "id %u", attach_info.flow_dissector_id); 701 NET_END_ARRAY("\n"); 702 703 NET_END_OBJECT; 704 if (json_output) 705 jsonw_end_array(json_wtr); 706 707 if (ret) { 708 if (json_output) 709 jsonw_null(json_wtr); 710 libbpf_strerror(ret, err_buf, sizeof(err_buf)); 711 fprintf(stderr, "Error: %s\n", err_buf); 712 } 713 free(dev_array.devices); 714 close(sock); 715 return ret; 716 } 717 718 static int do_help(int argc, char **argv) 719 { 720 if (json_output) { 721 jsonw_null(json_wtr); 722 return 0; 723 } 724 725 fprintf(stderr, 726 "Usage: %1$s %2$s { show | list } [dev <devname>]\n" 727 " %1$s %2$s attach ATTACH_TYPE PROG dev <devname> [ overwrite ]\n" 728 " %1$s %2$s detach ATTACH_TYPE dev <devname>\n" 729 " %1$s %2$s help\n" 730 "\n" 731 " " HELP_SPEC_PROGRAM "\n" 732 " ATTACH_TYPE := { xdp | xdpgeneric | xdpdrv | xdpoffload }\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