1 // SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) 2 // Copyright (C) 2018 Facebook 3 4 #ifndef _GNU_SOURCE 5 #define _GNU_SOURCE 6 #endif 7 #include <errno.h> 8 #include <fcntl.h> 9 #include <stdlib.h> 10 #include <string.h> 11 #include <time.h> 12 #include <unistd.h> 13 #include <bpf/bpf.h> 14 #include <bpf/libbpf.h> 15 #include <net/if.h> 16 #include <linux/rtnetlink.h> 17 #include <linux/socket.h> 18 #include <linux/tc_act/tc_bpf.h> 19 #include <sys/socket.h> 20 #include <sys/stat.h> 21 #include <sys/types.h> 22 23 #include "bpf/nlattr.h" 24 #include "main.h" 25 #include "netlink_dumper.h" 26 27 #ifndef SOL_NETLINK 28 #define SOL_NETLINK 270 29 #endif 30 31 struct ip_devname_ifindex { 32 char devname[64]; 33 int ifindex; 34 }; 35 36 struct bpf_netdev_t { 37 struct ip_devname_ifindex *devices; 38 int used_len; 39 int array_len; 40 int filter_idx; 41 }; 42 43 struct tc_kind_handle { 44 char kind[64]; 45 int handle; 46 }; 47 48 struct bpf_tcinfo_t { 49 struct tc_kind_handle *handle_array; 50 int used_len; 51 int array_len; 52 bool is_qdisc; 53 }; 54 55 struct bpf_filter_t { 56 const char *kind; 57 const char *devname; 58 int ifindex; 59 }; 60 61 struct bpf_attach_info { 62 __u32 flow_dissector_id; 63 }; 64 65 enum net_attach_type { 66 NET_ATTACH_TYPE_XDP, 67 NET_ATTACH_TYPE_XDP_GENERIC, 68 NET_ATTACH_TYPE_XDP_DRIVER, 69 NET_ATTACH_TYPE_XDP_OFFLOAD, 70 }; 71 72 static const char * const attach_type_strings[] = { 73 [NET_ATTACH_TYPE_XDP] = "xdp", 74 [NET_ATTACH_TYPE_XDP_GENERIC] = "xdpgeneric", 75 [NET_ATTACH_TYPE_XDP_DRIVER] = "xdpdrv", 76 [NET_ATTACH_TYPE_XDP_OFFLOAD] = "xdpoffload", 77 }; 78 79 const size_t net_attach_type_size = ARRAY_SIZE(attach_type_strings); 80 81 static enum net_attach_type parse_attach_type(const char *str) 82 { 83 enum net_attach_type type; 84 85 for (type = 0; type < net_attach_type_size; type++) { 86 if (attach_type_strings[type] && 87 is_prefix(str, attach_type_strings[type])) 88 return type; 89 } 90 91 return net_attach_type_size; 92 } 93 94 typedef int (*dump_nlmsg_t)(void *cookie, void *msg, struct nlattr **tb); 95 96 typedef int (*__dump_nlmsg_t)(struct nlmsghdr *nlmsg, dump_nlmsg_t, void *cookie); 97 98 static int netlink_open(__u32 *nl_pid) 99 { 100 struct sockaddr_nl sa; 101 socklen_t addrlen; 102 int one = 1, ret; 103 int sock; 104 105 memset(&sa, 0, sizeof(sa)); 106 sa.nl_family = AF_NETLINK; 107 108 sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE); 109 if (sock < 0) 110 return -errno; 111 112 if (setsockopt(sock, SOL_NETLINK, NETLINK_EXT_ACK, 113 &one, sizeof(one)) < 0) { 114 p_err("Netlink error reporting not supported"); 115 } 116 117 if (bind(sock, (struct sockaddr *)&sa, sizeof(sa)) < 0) { 118 ret = -errno; 119 goto cleanup; 120 } 121 122 addrlen = sizeof(sa); 123 if (getsockname(sock, (struct sockaddr *)&sa, &addrlen) < 0) { 124 ret = -errno; 125 goto cleanup; 126 } 127 128 if (addrlen != sizeof(sa)) { 129 ret = -LIBBPF_ERRNO__INTERNAL; 130 goto cleanup; 131 } 132 133 *nl_pid = sa.nl_pid; 134 return sock; 135 136 cleanup: 137 close(sock); 138 return ret; 139 } 140 141 static int netlink_recv(int sock, __u32 nl_pid, __u32 seq, 142 __dump_nlmsg_t _fn, dump_nlmsg_t fn, 143 void *cookie) 144 { 145 bool multipart = true; 146 struct nlmsgerr *err; 147 struct nlmsghdr *nh; 148 char buf[4096]; 149 int len, ret; 150 151 while (multipart) { 152 multipart = false; 153 len = recv(sock, buf, sizeof(buf), 0); 154 if (len < 0) { 155 ret = -errno; 156 goto done; 157 } 158 159 if (len == 0) 160 break; 161 162 for (nh = (struct nlmsghdr *)buf; NLMSG_OK(nh, (unsigned int)len); 163 nh = NLMSG_NEXT(nh, len)) { 164 if (nh->nlmsg_pid != nl_pid) { 165 ret = -LIBBPF_ERRNO__WRNGPID; 166 goto done; 167 } 168 if (nh->nlmsg_seq != seq) { 169 ret = -LIBBPF_ERRNO__INVSEQ; 170 goto done; 171 } 172 if (nh->nlmsg_flags & NLM_F_MULTI) 173 multipart = true; 174 switch (nh->nlmsg_type) { 175 case NLMSG_ERROR: 176 err = (struct nlmsgerr *)NLMSG_DATA(nh); 177 if (!err->error) 178 continue; 179 ret = err->error; 180 libbpf_nla_dump_errormsg(nh); 181 goto done; 182 case NLMSG_DONE: 183 return 0; 184 default: 185 break; 186 } 187 if (_fn) { 188 ret = _fn(nh, fn, cookie); 189 if (ret) 190 return ret; 191 } 192 } 193 } 194 ret = 0; 195 done: 196 return ret; 197 } 198 199 static int __dump_class_nlmsg(struct nlmsghdr *nlh, 200 dump_nlmsg_t dump_class_nlmsg, 201 void *cookie) 202 { 203 struct nlattr *tb[TCA_MAX + 1], *attr; 204 struct tcmsg *t = NLMSG_DATA(nlh); 205 int len; 206 207 len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*t)); 208 attr = (struct nlattr *) ((void *) t + NLMSG_ALIGN(sizeof(*t))); 209 if (libbpf_nla_parse(tb, TCA_MAX, attr, len, NULL) != 0) 210 return -LIBBPF_ERRNO__NLPARSE; 211 212 return dump_class_nlmsg(cookie, t, tb); 213 } 214 215 static int netlink_get_class(int sock, unsigned int nl_pid, int ifindex, 216 dump_nlmsg_t dump_class_nlmsg, void *cookie) 217 { 218 struct { 219 struct nlmsghdr nlh; 220 struct tcmsg t; 221 } req = { 222 .nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg)), 223 .nlh.nlmsg_type = RTM_GETTCLASS, 224 .nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST, 225 .t.tcm_family = AF_UNSPEC, 226 .t.tcm_ifindex = ifindex, 227 }; 228 int seq = time(NULL); 229 230 req.nlh.nlmsg_seq = seq; 231 if (send(sock, &req, req.nlh.nlmsg_len, 0) < 0) 232 return -errno; 233 234 return netlink_recv(sock, nl_pid, seq, __dump_class_nlmsg, 235 dump_class_nlmsg, cookie); 236 } 237 238 static int __dump_qdisc_nlmsg(struct nlmsghdr *nlh, 239 dump_nlmsg_t dump_qdisc_nlmsg, 240 void *cookie) 241 { 242 struct nlattr *tb[TCA_MAX + 1], *attr; 243 struct tcmsg *t = NLMSG_DATA(nlh); 244 int len; 245 246 len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*t)); 247 attr = (struct nlattr *) ((void *) t + NLMSG_ALIGN(sizeof(*t))); 248 if (libbpf_nla_parse(tb, TCA_MAX, attr, len, NULL) != 0) 249 return -LIBBPF_ERRNO__NLPARSE; 250 251 return dump_qdisc_nlmsg(cookie, t, tb); 252 } 253 254 static int netlink_get_qdisc(int sock, unsigned int nl_pid, int ifindex, 255 dump_nlmsg_t dump_qdisc_nlmsg, void *cookie) 256 { 257 struct { 258 struct nlmsghdr nlh; 259 struct tcmsg t; 260 } req = { 261 .nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg)), 262 .nlh.nlmsg_type = RTM_GETQDISC, 263 .nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST, 264 .t.tcm_family = AF_UNSPEC, 265 .t.tcm_ifindex = ifindex, 266 }; 267 int seq = time(NULL); 268 269 req.nlh.nlmsg_seq = seq; 270 if (send(sock, &req, req.nlh.nlmsg_len, 0) < 0) 271 return -errno; 272 273 return netlink_recv(sock, nl_pid, seq, __dump_qdisc_nlmsg, 274 dump_qdisc_nlmsg, cookie); 275 } 276 277 static int __dump_filter_nlmsg(struct nlmsghdr *nlh, 278 dump_nlmsg_t dump_filter_nlmsg, 279 void *cookie) 280 { 281 struct nlattr *tb[TCA_MAX + 1], *attr; 282 struct tcmsg *t = NLMSG_DATA(nlh); 283 int len; 284 285 len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*t)); 286 attr = (struct nlattr *) ((void *) t + NLMSG_ALIGN(sizeof(*t))); 287 if (libbpf_nla_parse(tb, TCA_MAX, attr, len, NULL) != 0) 288 return -LIBBPF_ERRNO__NLPARSE; 289 290 return dump_filter_nlmsg(cookie, t, tb); 291 } 292 293 static int netlink_get_filter(int sock, unsigned int nl_pid, int ifindex, int handle, 294 dump_nlmsg_t dump_filter_nlmsg, void *cookie) 295 { 296 struct { 297 struct nlmsghdr nlh; 298 struct tcmsg t; 299 } req = { 300 .nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg)), 301 .nlh.nlmsg_type = RTM_GETTFILTER, 302 .nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST, 303 .t.tcm_family = AF_UNSPEC, 304 .t.tcm_ifindex = ifindex, 305 .t.tcm_parent = handle, 306 }; 307 int seq = time(NULL); 308 309 req.nlh.nlmsg_seq = seq; 310 if (send(sock, &req, req.nlh.nlmsg_len, 0) < 0) 311 return -errno; 312 313 return netlink_recv(sock, nl_pid, seq, __dump_filter_nlmsg, 314 dump_filter_nlmsg, cookie); 315 } 316 317 static int __dump_link_nlmsg(struct nlmsghdr *nlh, 318 dump_nlmsg_t dump_link_nlmsg, void *cookie) 319 { 320 struct nlattr *tb[IFLA_MAX + 1], *attr; 321 struct ifinfomsg *ifi = NLMSG_DATA(nlh); 322 int len; 323 324 len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*ifi)); 325 attr = (struct nlattr *) ((void *) ifi + NLMSG_ALIGN(sizeof(*ifi))); 326 if (libbpf_nla_parse(tb, IFLA_MAX, attr, len, NULL) != 0) 327 return -LIBBPF_ERRNO__NLPARSE; 328 329 return dump_link_nlmsg(cookie, ifi, tb); 330 } 331 332 static int netlink_get_link(int sock, unsigned int nl_pid, 333 dump_nlmsg_t dump_link_nlmsg, void *cookie) 334 { 335 struct { 336 struct nlmsghdr nlh; 337 struct ifinfomsg ifm; 338 } req = { 339 .nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg)), 340 .nlh.nlmsg_type = RTM_GETLINK, 341 .nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST, 342 .ifm.ifi_family = AF_PACKET, 343 }; 344 int seq = time(NULL); 345 346 req.nlh.nlmsg_seq = seq; 347 if (send(sock, &req, req.nlh.nlmsg_len, 0) < 0) 348 return -errno; 349 350 return netlink_recv(sock, nl_pid, seq, __dump_link_nlmsg, 351 dump_link_nlmsg, cookie); 352 } 353 354 static int dump_link_nlmsg(void *cookie, void *msg, struct nlattr **tb) 355 { 356 struct bpf_netdev_t *netinfo = cookie; 357 struct ifinfomsg *ifinfo = msg; 358 359 if (netinfo->filter_idx > 0 && netinfo->filter_idx != ifinfo->ifi_index) 360 return 0; 361 362 if (netinfo->used_len == netinfo->array_len) { 363 netinfo->devices = realloc(netinfo->devices, 364 (netinfo->array_len + 16) * 365 sizeof(struct ip_devname_ifindex)); 366 if (!netinfo->devices) 367 return -ENOMEM; 368 369 netinfo->array_len += 16; 370 } 371 netinfo->devices[netinfo->used_len].ifindex = ifinfo->ifi_index; 372 snprintf(netinfo->devices[netinfo->used_len].devname, 373 sizeof(netinfo->devices[netinfo->used_len].devname), 374 "%s", 375 tb[IFLA_IFNAME] 376 ? libbpf_nla_getattr_str(tb[IFLA_IFNAME]) 377 : ""); 378 netinfo->used_len++; 379 380 return do_xdp_dump(ifinfo, tb); 381 } 382 383 static int dump_class_qdisc_nlmsg(void *cookie, void *msg, struct nlattr **tb) 384 { 385 struct bpf_tcinfo_t *tcinfo = cookie; 386 struct tcmsg *info = msg; 387 388 if (tcinfo->is_qdisc) { 389 /* skip clsact qdisc */ 390 if (tb[TCA_KIND] && 391 strcmp(libbpf_nla_data(tb[TCA_KIND]), "clsact") == 0) 392 return 0; 393 if (info->tcm_handle == 0) 394 return 0; 395 } 396 397 if (tcinfo->used_len == tcinfo->array_len) { 398 tcinfo->handle_array = realloc(tcinfo->handle_array, 399 (tcinfo->array_len + 16) * sizeof(struct tc_kind_handle)); 400 if (!tcinfo->handle_array) 401 return -ENOMEM; 402 403 tcinfo->array_len += 16; 404 } 405 tcinfo->handle_array[tcinfo->used_len].handle = info->tcm_handle; 406 snprintf(tcinfo->handle_array[tcinfo->used_len].kind, 407 sizeof(tcinfo->handle_array[tcinfo->used_len].kind), 408 "%s", 409 tb[TCA_KIND] 410 ? libbpf_nla_getattr_str(tb[TCA_KIND]) 411 : "unknown"); 412 tcinfo->used_len++; 413 414 return 0; 415 } 416 417 static int dump_filter_nlmsg(void *cookie, void *msg, struct nlattr **tb) 418 { 419 const struct bpf_filter_t *filter_info = cookie; 420 421 return do_filter_dump((struct tcmsg *)msg, tb, filter_info->kind, 422 filter_info->devname, filter_info->ifindex); 423 } 424 425 static int show_dev_tc_bpf(int sock, unsigned int nl_pid, 426 struct ip_devname_ifindex *dev) 427 { 428 struct bpf_filter_t filter_info; 429 struct bpf_tcinfo_t tcinfo; 430 int i, handle, ret = 0; 431 432 tcinfo.handle_array = NULL; 433 tcinfo.used_len = 0; 434 tcinfo.array_len = 0; 435 436 tcinfo.is_qdisc = false; 437 ret = netlink_get_class(sock, nl_pid, dev->ifindex, 438 dump_class_qdisc_nlmsg, &tcinfo); 439 if (ret) 440 goto out; 441 442 tcinfo.is_qdisc = true; 443 ret = netlink_get_qdisc(sock, nl_pid, dev->ifindex, 444 dump_class_qdisc_nlmsg, &tcinfo); 445 if (ret) 446 goto out; 447 448 filter_info.devname = dev->devname; 449 filter_info.ifindex = dev->ifindex; 450 for (i = 0; i < tcinfo.used_len; i++) { 451 filter_info.kind = tcinfo.handle_array[i].kind; 452 ret = netlink_get_filter(sock, nl_pid, dev->ifindex, 453 tcinfo.handle_array[i].handle, 454 dump_filter_nlmsg, &filter_info); 455 if (ret) 456 goto out; 457 } 458 459 /* root, ingress and egress handle */ 460 handle = TC_H_ROOT; 461 filter_info.kind = "root"; 462 ret = netlink_get_filter(sock, nl_pid, dev->ifindex, handle, 463 dump_filter_nlmsg, &filter_info); 464 if (ret) 465 goto out; 466 467 handle = TC_H_MAKE(TC_H_CLSACT, TC_H_MIN_INGRESS); 468 filter_info.kind = "clsact/ingress"; 469 ret = netlink_get_filter(sock, nl_pid, dev->ifindex, handle, 470 dump_filter_nlmsg, &filter_info); 471 if (ret) 472 goto out; 473 474 handle = TC_H_MAKE(TC_H_CLSACT, TC_H_MIN_EGRESS); 475 filter_info.kind = "clsact/egress"; 476 ret = netlink_get_filter(sock, nl_pid, dev->ifindex, handle, 477 dump_filter_nlmsg, &filter_info); 478 if (ret) 479 goto out; 480 481 out: 482 free(tcinfo.handle_array); 483 return 0; 484 } 485 486 static int query_flow_dissector(struct bpf_attach_info *attach_info) 487 { 488 __u32 attach_flags; 489 __u32 prog_ids[1]; 490 __u32 prog_cnt; 491 int err; 492 int fd; 493 494 fd = open("/proc/self/ns/net", O_RDONLY); 495 if (fd < 0) { 496 p_err("can't open /proc/self/ns/net: %s", 497 strerror(errno)); 498 return -1; 499 } 500 prog_cnt = ARRAY_SIZE(prog_ids); 501 err = bpf_prog_query(fd, BPF_FLOW_DISSECTOR, 0, 502 &attach_flags, prog_ids, &prog_cnt); 503 close(fd); 504 if (err) { 505 if (errno == EINVAL) { 506 /* Older kernel's don't support querying 507 * flow dissector programs. 508 */ 509 errno = 0; 510 return 0; 511 } 512 p_err("can't query prog: %s", strerror(errno)); 513 return -1; 514 } 515 516 if (prog_cnt == 1) 517 attach_info->flow_dissector_id = prog_ids[0]; 518 519 return 0; 520 } 521 522 static int net_parse_dev(int *argc, char ***argv) 523 { 524 int ifindex; 525 526 if (is_prefix(**argv, "dev")) { 527 NEXT_ARGP(); 528 529 ifindex = if_nametoindex(**argv); 530 if (!ifindex) 531 p_err("invalid devname %s", **argv); 532 533 NEXT_ARGP(); 534 } else { 535 p_err("expected 'dev', got: '%s'?", **argv); 536 return -1; 537 } 538 539 return ifindex; 540 } 541 542 static int do_attach_detach_xdp(int progfd, enum net_attach_type attach_type, 543 int ifindex, bool overwrite) 544 { 545 __u32 flags = 0; 546 547 if (!overwrite) 548 flags = XDP_FLAGS_UPDATE_IF_NOEXIST; 549 if (attach_type == NET_ATTACH_TYPE_XDP_GENERIC) 550 flags |= XDP_FLAGS_SKB_MODE; 551 if (attach_type == NET_ATTACH_TYPE_XDP_DRIVER) 552 flags |= XDP_FLAGS_DRV_MODE; 553 if (attach_type == NET_ATTACH_TYPE_XDP_OFFLOAD) 554 flags |= XDP_FLAGS_HW_MODE; 555 556 return bpf_xdp_attach(ifindex, progfd, flags, NULL); 557 } 558 559 static int do_attach(int argc, char **argv) 560 { 561 enum net_attach_type attach_type; 562 int progfd, ifindex, err = 0; 563 bool overwrite = false; 564 565 /* parse attach args */ 566 if (!REQ_ARGS(5)) 567 return -EINVAL; 568 569 attach_type = parse_attach_type(*argv); 570 if (attach_type == net_attach_type_size) { 571 p_err("invalid net attach/detach type: %s", *argv); 572 return -EINVAL; 573 } 574 NEXT_ARG(); 575 576 progfd = prog_parse_fd(&argc, &argv); 577 if (progfd < 0) 578 return -EINVAL; 579 580 ifindex = net_parse_dev(&argc, &argv); 581 if (ifindex < 1) { 582 err = -EINVAL; 583 goto cleanup; 584 } 585 586 if (argc) { 587 if (is_prefix(*argv, "overwrite")) { 588 overwrite = true; 589 } else { 590 p_err("expected 'overwrite', got: '%s'?", *argv); 591 err = -EINVAL; 592 goto cleanup; 593 } 594 } 595 596 /* attach xdp prog */ 597 if (is_prefix("xdp", attach_type_strings[attach_type])) 598 err = do_attach_detach_xdp(progfd, attach_type, ifindex, 599 overwrite); 600 if (err) { 601 p_err("interface %s attach failed: %s", 602 attach_type_strings[attach_type], strerror(-err)); 603 goto cleanup; 604 } 605 606 if (json_output) 607 jsonw_null(json_wtr); 608 cleanup: 609 close(progfd); 610 return err; 611 } 612 613 static int do_detach(int argc, char **argv) 614 { 615 enum net_attach_type attach_type; 616 int progfd, ifindex, err = 0; 617 618 /* parse detach args */ 619 if (!REQ_ARGS(3)) 620 return -EINVAL; 621 622 attach_type = parse_attach_type(*argv); 623 if (attach_type == net_attach_type_size) { 624 p_err("invalid net attach/detach type: %s", *argv); 625 return -EINVAL; 626 } 627 NEXT_ARG(); 628 629 ifindex = net_parse_dev(&argc, &argv); 630 if (ifindex < 1) 631 return -EINVAL; 632 633 /* detach xdp prog */ 634 progfd = -1; 635 if (is_prefix("xdp", attach_type_strings[attach_type])) 636 err = do_attach_detach_xdp(progfd, attach_type, ifindex, NULL); 637 638 if (err < 0) { 639 p_err("interface %s detach failed: %s", 640 attach_type_strings[attach_type], strerror(-err)); 641 return err; 642 } 643 644 if (json_output) 645 jsonw_null(json_wtr); 646 647 return 0; 648 } 649 650 static int netfilter_link_compar(const void *a, const void *b) 651 { 652 const struct bpf_link_info *nfa = a; 653 const struct bpf_link_info *nfb = b; 654 int delta; 655 656 delta = nfa->netfilter.pf - nfb->netfilter.pf; 657 if (delta) 658 return delta; 659 660 delta = nfa->netfilter.hooknum - nfb->netfilter.hooknum; 661 if (delta) 662 return delta; 663 664 if (nfa->netfilter.priority < nfb->netfilter.priority) 665 return -1; 666 if (nfa->netfilter.priority > nfb->netfilter.priority) 667 return 1; 668 669 return nfa->netfilter.flags - nfb->netfilter.flags; 670 } 671 672 static void show_link_netfilter(void) 673 { 674 unsigned int nf_link_len = 0, nf_link_count = 0; 675 struct bpf_link_info *nf_link_info = NULL; 676 __u32 id = 0; 677 678 while (true) { 679 struct bpf_link_info info; 680 int fd, err; 681 __u32 len; 682 683 err = bpf_link_get_next_id(id, &id); 684 if (err) { 685 if (errno == ENOENT) 686 break; 687 p_err("can't get next link: %s (id %d)", strerror(errno), id); 688 break; 689 } 690 691 fd = bpf_link_get_fd_by_id(id); 692 if (fd < 0) { 693 p_err("can't get link by id (%u): %s", id, strerror(errno)); 694 continue; 695 } 696 697 memset(&info, 0, sizeof(info)); 698 len = sizeof(info); 699 700 err = bpf_link_get_info_by_fd(fd, &info, &len); 701 702 close(fd); 703 704 if (err) { 705 p_err("can't get link info for fd %d: %s", fd, strerror(errno)); 706 continue; 707 } 708 709 if (info.type != BPF_LINK_TYPE_NETFILTER) 710 continue; 711 712 if (nf_link_count >= nf_link_len) { 713 static const unsigned int max_link_count = INT_MAX / sizeof(info); 714 struct bpf_link_info *expand; 715 716 if (nf_link_count > max_link_count) { 717 p_err("cannot handle more than %u links\n", max_link_count); 718 break; 719 } 720 721 nf_link_len += 16; 722 723 expand = realloc(nf_link_info, nf_link_len * sizeof(info)); 724 if (!expand) { 725 p_err("realloc: %s", strerror(errno)); 726 break; 727 } 728 729 nf_link_info = expand; 730 } 731 732 nf_link_info[nf_link_count] = info; 733 nf_link_count++; 734 } 735 736 qsort(nf_link_info, nf_link_count, sizeof(*nf_link_info), netfilter_link_compar); 737 738 for (id = 0; id < nf_link_count; id++) { 739 NET_START_OBJECT; 740 if (json_output) 741 netfilter_dump_json(&nf_link_info[id], json_wtr); 742 else 743 netfilter_dump_plain(&nf_link_info[id]); 744 745 NET_DUMP_UINT("id", " prog_id %u", nf_link_info[id].prog_id); 746 NET_END_OBJECT; 747 } 748 749 free(nf_link_info); 750 } 751 752 static int do_show(int argc, char **argv) 753 { 754 struct bpf_attach_info attach_info = {}; 755 int i, sock, ret, filter_idx = -1; 756 struct bpf_netdev_t dev_array; 757 unsigned int nl_pid = 0; 758 char err_buf[256]; 759 760 if (argc == 2) { 761 filter_idx = net_parse_dev(&argc, &argv); 762 if (filter_idx < 1) 763 return -1; 764 } else if (argc != 0) { 765 usage(); 766 } 767 768 ret = query_flow_dissector(&attach_info); 769 if (ret) 770 return -1; 771 772 sock = netlink_open(&nl_pid); 773 if (sock < 0) { 774 fprintf(stderr, "failed to open netlink sock\n"); 775 return -1; 776 } 777 778 dev_array.devices = NULL; 779 dev_array.used_len = 0; 780 dev_array.array_len = 0; 781 dev_array.filter_idx = filter_idx; 782 783 if (json_output) 784 jsonw_start_array(json_wtr); 785 NET_START_OBJECT; 786 NET_START_ARRAY("xdp", "%s:\n"); 787 ret = netlink_get_link(sock, nl_pid, dump_link_nlmsg, &dev_array); 788 NET_END_ARRAY("\n"); 789 790 if (!ret) { 791 NET_START_ARRAY("tc", "%s:\n"); 792 for (i = 0; i < dev_array.used_len; i++) { 793 ret = show_dev_tc_bpf(sock, nl_pid, 794 &dev_array.devices[i]); 795 if (ret) 796 break; 797 } 798 NET_END_ARRAY("\n"); 799 } 800 801 NET_START_ARRAY("flow_dissector", "%s:\n"); 802 if (attach_info.flow_dissector_id > 0) 803 NET_DUMP_UINT("id", "id %u", attach_info.flow_dissector_id); 804 NET_END_ARRAY("\n"); 805 806 NET_START_ARRAY("netfilter", "%s:\n"); 807 show_link_netfilter(); 808 NET_END_ARRAY("\n"); 809 810 NET_END_OBJECT; 811 if (json_output) 812 jsonw_end_array(json_wtr); 813 814 if (ret) { 815 if (json_output) 816 jsonw_null(json_wtr); 817 libbpf_strerror(ret, err_buf, sizeof(err_buf)); 818 fprintf(stderr, "Error: %s\n", err_buf); 819 } 820 free(dev_array.devices); 821 close(sock); 822 return ret; 823 } 824 825 static int do_help(int argc, char **argv) 826 { 827 if (json_output) { 828 jsonw_null(json_wtr); 829 return 0; 830 } 831 832 fprintf(stderr, 833 "Usage: %1$s %2$s { show | list } [dev <devname>]\n" 834 " %1$s %2$s attach ATTACH_TYPE PROG dev <devname> [ overwrite ]\n" 835 " %1$s %2$s detach ATTACH_TYPE dev <devname>\n" 836 " %1$s %2$s help\n" 837 "\n" 838 " " HELP_SPEC_PROGRAM "\n" 839 " ATTACH_TYPE := { xdp | xdpgeneric | xdpdrv | xdpoffload }\n" 840 " " HELP_SPEC_OPTIONS " }\n" 841 "\n" 842 "Note: Only xdp and tc attachments are supported now.\n" 843 " For progs attached to cgroups, use \"bpftool cgroup\"\n" 844 " to dump program attachments. For program types\n" 845 " sk_{filter,skb,msg,reuseport} and lwt/seg6, please\n" 846 " consult iproute2.\n" 847 "", 848 bin_name, argv[-2]); 849 850 return 0; 851 } 852 853 static const struct cmd cmds[] = { 854 { "show", do_show }, 855 { "list", do_show }, 856 { "attach", do_attach }, 857 { "detach", do_detach }, 858 { "help", do_help }, 859 { 0 } 860 }; 861 862 int do_net(int argc, char **argv) 863 { 864 return cmd_select(cmds, argc, argv, do_help); 865 } 866