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 NET_ATTACH_TYPE_TCX_INGRESS, 71 NET_ATTACH_TYPE_TCX_EGRESS, 72 }; 73 74 static const char * const attach_type_strings[] = { 75 [NET_ATTACH_TYPE_XDP] = "xdp", 76 [NET_ATTACH_TYPE_XDP_GENERIC] = "xdpgeneric", 77 [NET_ATTACH_TYPE_XDP_DRIVER] = "xdpdrv", 78 [NET_ATTACH_TYPE_XDP_OFFLOAD] = "xdpoffload", 79 [NET_ATTACH_TYPE_TCX_INGRESS] = "tcx_ingress", 80 [NET_ATTACH_TYPE_TCX_EGRESS] = "tcx_egress", 81 }; 82 83 static const char * const attach_loc_strings[] = { 84 [BPF_TCX_INGRESS] = "tcx/ingress", 85 [BPF_TCX_EGRESS] = "tcx/egress", 86 [BPF_NETKIT_PRIMARY] = "netkit/primary", 87 [BPF_NETKIT_PEER] = "netkit/peer", 88 }; 89 90 const size_t net_attach_type_size = ARRAY_SIZE(attach_type_strings); 91 92 static enum net_attach_type parse_attach_type(const char *str) 93 { 94 enum net_attach_type type; 95 96 for (type = 0; type < net_attach_type_size; type++) { 97 if (attach_type_strings[type] && 98 is_prefix(str, attach_type_strings[type])) 99 return type; 100 } 101 102 return net_attach_type_size; 103 } 104 105 typedef int (*dump_nlmsg_t)(void *cookie, void *msg, struct nlattr **tb); 106 107 typedef int (*__dump_nlmsg_t)(struct nlmsghdr *nlmsg, dump_nlmsg_t, void *cookie); 108 109 static int netlink_open(__u32 *nl_pid) 110 { 111 struct sockaddr_nl sa; 112 socklen_t addrlen; 113 int one = 1, ret; 114 int sock; 115 116 memset(&sa, 0, sizeof(sa)); 117 sa.nl_family = AF_NETLINK; 118 119 sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE); 120 if (sock < 0) 121 return -errno; 122 123 if (setsockopt(sock, SOL_NETLINK, NETLINK_EXT_ACK, 124 &one, sizeof(one)) < 0) { 125 p_err("Netlink error reporting not supported"); 126 } 127 128 if (bind(sock, (struct sockaddr *)&sa, sizeof(sa)) < 0) { 129 ret = -errno; 130 goto cleanup; 131 } 132 133 addrlen = sizeof(sa); 134 if (getsockname(sock, (struct sockaddr *)&sa, &addrlen) < 0) { 135 ret = -errno; 136 goto cleanup; 137 } 138 139 if (addrlen != sizeof(sa)) { 140 ret = -LIBBPF_ERRNO__INTERNAL; 141 goto cleanup; 142 } 143 144 *nl_pid = sa.nl_pid; 145 return sock; 146 147 cleanup: 148 close(sock); 149 return ret; 150 } 151 152 static int netlink_recv(int sock, __u32 nl_pid, __u32 seq, 153 __dump_nlmsg_t _fn, dump_nlmsg_t fn, 154 void *cookie) 155 { 156 bool multipart = true; 157 struct nlmsgerr *err; 158 struct nlmsghdr *nh; 159 char buf[8192]; 160 int len, ret; 161 162 while (multipart) { 163 multipart = false; 164 len = recv(sock, buf, sizeof(buf), 0); 165 if (len < 0) { 166 ret = -errno; 167 goto done; 168 } 169 170 if (len == 0) 171 break; 172 173 for (nh = (struct nlmsghdr *)buf; NLMSG_OK(nh, (unsigned int)len); 174 nh = NLMSG_NEXT(nh, len)) { 175 if (nh->nlmsg_pid != nl_pid) { 176 ret = -LIBBPF_ERRNO__WRNGPID; 177 goto done; 178 } 179 if (nh->nlmsg_seq != seq) { 180 ret = -LIBBPF_ERRNO__INVSEQ; 181 goto done; 182 } 183 if (nh->nlmsg_flags & NLM_F_MULTI) 184 multipart = true; 185 switch (nh->nlmsg_type) { 186 case NLMSG_ERROR: 187 err = (struct nlmsgerr *)NLMSG_DATA(nh); 188 if (!err->error) 189 continue; 190 ret = err->error; 191 libbpf_nla_dump_errormsg(nh); 192 goto done; 193 case NLMSG_DONE: 194 return 0; 195 default: 196 break; 197 } 198 if (_fn) { 199 ret = _fn(nh, fn, cookie); 200 if (ret) 201 return ret; 202 } 203 } 204 205 if (len) 206 p_err("Invalid message or trailing data in Netlink response: %d bytes left", len); 207 } 208 ret = 0; 209 done: 210 return ret; 211 } 212 213 static int __dump_class_nlmsg(struct nlmsghdr *nlh, 214 dump_nlmsg_t dump_class_nlmsg, 215 void *cookie) 216 { 217 struct nlattr *tb[TCA_MAX + 1], *attr; 218 struct tcmsg *t = NLMSG_DATA(nlh); 219 int len; 220 221 len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*t)); 222 attr = (struct nlattr *) ((void *) t + NLMSG_ALIGN(sizeof(*t))); 223 if (libbpf_nla_parse(tb, TCA_MAX, attr, len, NULL) != 0) 224 return -LIBBPF_ERRNO__NLPARSE; 225 226 return dump_class_nlmsg(cookie, t, tb); 227 } 228 229 static int netlink_get_class(int sock, unsigned int nl_pid, int ifindex, 230 dump_nlmsg_t dump_class_nlmsg, void *cookie) 231 { 232 struct { 233 struct nlmsghdr nlh; 234 struct tcmsg t; 235 } req = { 236 .nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg)), 237 .nlh.nlmsg_type = RTM_GETTCLASS, 238 .nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST, 239 .t.tcm_family = AF_UNSPEC, 240 .t.tcm_ifindex = ifindex, 241 }; 242 int seq = time(NULL); 243 244 req.nlh.nlmsg_seq = seq; 245 if (send(sock, &req, req.nlh.nlmsg_len, 0) < 0) 246 return -errno; 247 248 return netlink_recv(sock, nl_pid, seq, __dump_class_nlmsg, 249 dump_class_nlmsg, cookie); 250 } 251 252 static int __dump_qdisc_nlmsg(struct nlmsghdr *nlh, 253 dump_nlmsg_t dump_qdisc_nlmsg, 254 void *cookie) 255 { 256 struct nlattr *tb[TCA_MAX + 1], *attr; 257 struct tcmsg *t = NLMSG_DATA(nlh); 258 int len; 259 260 len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*t)); 261 attr = (struct nlattr *) ((void *) t + NLMSG_ALIGN(sizeof(*t))); 262 if (libbpf_nla_parse(tb, TCA_MAX, attr, len, NULL) != 0) 263 return -LIBBPF_ERRNO__NLPARSE; 264 265 return dump_qdisc_nlmsg(cookie, t, tb); 266 } 267 268 static int netlink_get_qdisc(int sock, unsigned int nl_pid, int ifindex, 269 dump_nlmsg_t dump_qdisc_nlmsg, void *cookie) 270 { 271 struct { 272 struct nlmsghdr nlh; 273 struct tcmsg t; 274 } req = { 275 .nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg)), 276 .nlh.nlmsg_type = RTM_GETQDISC, 277 .nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST, 278 .t.tcm_family = AF_UNSPEC, 279 .t.tcm_ifindex = ifindex, 280 }; 281 int seq = time(NULL); 282 283 req.nlh.nlmsg_seq = seq; 284 if (send(sock, &req, req.nlh.nlmsg_len, 0) < 0) 285 return -errno; 286 287 return netlink_recv(sock, nl_pid, seq, __dump_qdisc_nlmsg, 288 dump_qdisc_nlmsg, cookie); 289 } 290 291 static int __dump_filter_nlmsg(struct nlmsghdr *nlh, 292 dump_nlmsg_t dump_filter_nlmsg, 293 void *cookie) 294 { 295 struct nlattr *tb[TCA_MAX + 1], *attr; 296 struct tcmsg *t = NLMSG_DATA(nlh); 297 int len; 298 299 len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*t)); 300 attr = (struct nlattr *) ((void *) t + NLMSG_ALIGN(sizeof(*t))); 301 if (libbpf_nla_parse(tb, TCA_MAX, attr, len, NULL) != 0) 302 return -LIBBPF_ERRNO__NLPARSE; 303 304 return dump_filter_nlmsg(cookie, t, tb); 305 } 306 307 static int netlink_get_filter(int sock, unsigned int nl_pid, int ifindex, int handle, 308 dump_nlmsg_t dump_filter_nlmsg, void *cookie) 309 { 310 struct { 311 struct nlmsghdr nlh; 312 struct tcmsg t; 313 } req = { 314 .nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg)), 315 .nlh.nlmsg_type = RTM_GETTFILTER, 316 .nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST, 317 .t.tcm_family = AF_UNSPEC, 318 .t.tcm_ifindex = ifindex, 319 .t.tcm_parent = handle, 320 }; 321 int seq = time(NULL); 322 323 req.nlh.nlmsg_seq = seq; 324 if (send(sock, &req, req.nlh.nlmsg_len, 0) < 0) 325 return -errno; 326 327 return netlink_recv(sock, nl_pid, seq, __dump_filter_nlmsg, 328 dump_filter_nlmsg, cookie); 329 } 330 331 static int __dump_link_nlmsg(struct nlmsghdr *nlh, 332 dump_nlmsg_t dump_link_nlmsg, void *cookie) 333 { 334 struct nlattr *tb[IFLA_MAX + 1], *attr; 335 struct ifinfomsg *ifi = NLMSG_DATA(nlh); 336 int len; 337 338 len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*ifi)); 339 attr = (struct nlattr *) ((void *) ifi + NLMSG_ALIGN(sizeof(*ifi))); 340 if (libbpf_nla_parse(tb, IFLA_MAX, attr, len, NULL) != 0) 341 return -LIBBPF_ERRNO__NLPARSE; 342 343 return dump_link_nlmsg(cookie, ifi, tb); 344 } 345 346 static int netlink_get_link(int sock, unsigned int nl_pid, 347 dump_nlmsg_t dump_link_nlmsg, void *cookie) 348 { 349 struct { 350 struct nlmsghdr nlh; 351 struct ifinfomsg ifm; 352 } req = { 353 .nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg)), 354 .nlh.nlmsg_type = RTM_GETLINK, 355 .nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST, 356 .ifm.ifi_family = AF_PACKET, 357 }; 358 int seq = time(NULL); 359 360 req.nlh.nlmsg_seq = seq; 361 if (send(sock, &req, req.nlh.nlmsg_len, 0) < 0) 362 return -errno; 363 364 return netlink_recv(sock, nl_pid, seq, __dump_link_nlmsg, 365 dump_link_nlmsg, cookie); 366 } 367 368 static int dump_link_nlmsg(void *cookie, void *msg, struct nlattr **tb) 369 { 370 struct bpf_netdev_t *netinfo = cookie; 371 struct ifinfomsg *ifinfo = msg; 372 struct ip_devname_ifindex *tmp; 373 374 if (netinfo->filter_idx > 0 && netinfo->filter_idx != ifinfo->ifi_index) 375 return 0; 376 377 if (netinfo->used_len == netinfo->array_len) { 378 tmp = realloc(netinfo->devices, 379 (netinfo->array_len + 16) * sizeof(struct ip_devname_ifindex)); 380 if (!tmp) 381 return -ENOMEM; 382 383 netinfo->devices = tmp; 384 netinfo->array_len += 16; 385 } 386 netinfo->devices[netinfo->used_len].ifindex = ifinfo->ifi_index; 387 snprintf(netinfo->devices[netinfo->used_len].devname, 388 sizeof(netinfo->devices[netinfo->used_len].devname), 389 "%s", 390 tb[IFLA_IFNAME] 391 ? libbpf_nla_getattr_str(tb[IFLA_IFNAME]) 392 : ""); 393 netinfo->used_len++; 394 395 return do_xdp_dump(ifinfo, tb); 396 } 397 398 static int dump_class_qdisc_nlmsg(void *cookie, void *msg, struct nlattr **tb) 399 { 400 struct bpf_tcinfo_t *tcinfo = cookie; 401 struct tcmsg *info = msg; 402 struct tc_kind_handle *tmp; 403 404 if (tcinfo->is_qdisc) { 405 /* skip clsact qdisc */ 406 if (tb[TCA_KIND] && 407 strcmp(libbpf_nla_data(tb[TCA_KIND]), "clsact") == 0) 408 return 0; 409 if (info->tcm_handle == 0) 410 return 0; 411 } 412 413 if (tcinfo->used_len == tcinfo->array_len) { 414 tmp = realloc(tcinfo->handle_array, 415 (tcinfo->array_len + 16) * sizeof(struct tc_kind_handle)); 416 if (!tmp) 417 return -ENOMEM; 418 419 tcinfo->handle_array = tmp; 420 tcinfo->array_len += 16; 421 } 422 tcinfo->handle_array[tcinfo->used_len].handle = info->tcm_handle; 423 snprintf(tcinfo->handle_array[tcinfo->used_len].kind, 424 sizeof(tcinfo->handle_array[tcinfo->used_len].kind), 425 "%s", 426 tb[TCA_KIND] 427 ? libbpf_nla_getattr_str(tb[TCA_KIND]) 428 : "unknown"); 429 tcinfo->used_len++; 430 431 return 0; 432 } 433 434 static int dump_filter_nlmsg(void *cookie, void *msg, struct nlattr **tb) 435 { 436 const struct bpf_filter_t *filter_info = cookie; 437 438 return do_filter_dump((struct tcmsg *)msg, tb, filter_info->kind, 439 filter_info->devname, filter_info->ifindex); 440 } 441 442 static int __show_dev_tc_bpf_name(__u32 id, char *name, size_t len) 443 { 444 struct bpf_prog_info info = {}; 445 __u32 ilen = sizeof(info); 446 int fd, ret; 447 448 fd = bpf_prog_get_fd_by_id(id); 449 if (fd < 0) 450 return fd; 451 ret = bpf_obj_get_info_by_fd(fd, &info, &ilen); 452 if (ret < 0) 453 goto out; 454 ret = -ENOENT; 455 if (info.name[0]) { 456 get_prog_full_name(&info, fd, name, len); 457 ret = 0; 458 } 459 out: 460 close(fd); 461 return ret; 462 } 463 464 static void __show_dev_tc_bpf(const struct ip_devname_ifindex *dev, 465 const enum bpf_attach_type loc) 466 { 467 __u32 prog_flags[64] = {}, link_flags[64] = {}, i, j; 468 __u32 prog_ids[64] = {}, link_ids[64] = {}; 469 LIBBPF_OPTS(bpf_prog_query_opts, optq); 470 char prog_name[MAX_PROG_FULL_NAME]; 471 int ret; 472 473 optq.prog_ids = prog_ids; 474 optq.prog_attach_flags = prog_flags; 475 optq.link_ids = link_ids; 476 optq.link_attach_flags = link_flags; 477 optq.count = ARRAY_SIZE(prog_ids); 478 479 ret = bpf_prog_query_opts(dev->ifindex, loc, &optq); 480 if (ret) 481 return; 482 for (i = 0; i < optq.count; i++) { 483 NET_START_OBJECT; 484 NET_DUMP_STR("devname", "%s", dev->devname); 485 NET_DUMP_UINT("ifindex", "(%u)", (unsigned int)dev->ifindex); 486 NET_DUMP_STR("kind", " %s", attach_loc_strings[loc]); 487 ret = __show_dev_tc_bpf_name(prog_ids[i], prog_name, 488 sizeof(prog_name)); 489 if (!ret) 490 NET_DUMP_STR("name", " %s", prog_name); 491 NET_DUMP_UINT("prog_id", " prog_id %u ", prog_ids[i]); 492 if (prog_flags[i] || json_output) { 493 NET_START_ARRAY("prog_flags", "%s "); 494 for (j = 0; prog_flags[i] && j < 32; j++) { 495 if (!(prog_flags[i] & (1U << j))) 496 continue; 497 NET_DUMP_UINT_ONLY(1U << j); 498 } 499 NET_END_ARRAY(""); 500 } 501 if (link_ids[i] || json_output) { 502 NET_DUMP_UINT("link_id", "link_id %u ", link_ids[i]); 503 if (link_flags[i] || json_output) { 504 NET_START_ARRAY("link_flags", "%s "); 505 for (j = 0; link_flags[i] && j < 32; j++) { 506 if (!(link_flags[i] & (1U << j))) 507 continue; 508 NET_DUMP_UINT_ONLY(1U << j); 509 } 510 NET_END_ARRAY(""); 511 } 512 } 513 NET_END_OBJECT_FINAL; 514 } 515 } 516 517 static void show_dev_tc_bpf(struct ip_devname_ifindex *dev) 518 { 519 __show_dev_tc_bpf(dev, BPF_TCX_INGRESS); 520 __show_dev_tc_bpf(dev, BPF_TCX_EGRESS); 521 522 __show_dev_tc_bpf(dev, BPF_NETKIT_PRIMARY); 523 __show_dev_tc_bpf(dev, BPF_NETKIT_PEER); 524 } 525 526 static int show_dev_tc_bpf_classic(int sock, unsigned int nl_pid, 527 struct ip_devname_ifindex *dev) 528 { 529 struct bpf_filter_t filter_info; 530 struct bpf_tcinfo_t tcinfo; 531 int i, handle, ret = 0; 532 533 tcinfo.handle_array = NULL; 534 tcinfo.used_len = 0; 535 tcinfo.array_len = 0; 536 537 tcinfo.is_qdisc = false; 538 ret = netlink_get_class(sock, nl_pid, dev->ifindex, 539 dump_class_qdisc_nlmsg, &tcinfo); 540 if (ret) 541 goto out; 542 543 tcinfo.is_qdisc = true; 544 ret = netlink_get_qdisc(sock, nl_pid, dev->ifindex, 545 dump_class_qdisc_nlmsg, &tcinfo); 546 if (ret) 547 goto out; 548 549 filter_info.devname = dev->devname; 550 filter_info.ifindex = dev->ifindex; 551 for (i = 0; i < tcinfo.used_len; i++) { 552 filter_info.kind = tcinfo.handle_array[i].kind; 553 ret = netlink_get_filter(sock, nl_pid, dev->ifindex, 554 tcinfo.handle_array[i].handle, 555 dump_filter_nlmsg, &filter_info); 556 if (ret) 557 goto out; 558 } 559 560 /* root, ingress and egress handle */ 561 handle = TC_H_ROOT; 562 filter_info.kind = "root"; 563 ret = netlink_get_filter(sock, nl_pid, dev->ifindex, handle, 564 dump_filter_nlmsg, &filter_info); 565 if (ret) 566 goto out; 567 568 handle = TC_H_MAKE(TC_H_CLSACT, TC_H_MIN_INGRESS); 569 filter_info.kind = "clsact/ingress"; 570 ret = netlink_get_filter(sock, nl_pid, dev->ifindex, handle, 571 dump_filter_nlmsg, &filter_info); 572 if (ret) 573 goto out; 574 575 handle = TC_H_MAKE(TC_H_CLSACT, TC_H_MIN_EGRESS); 576 filter_info.kind = "clsact/egress"; 577 ret = netlink_get_filter(sock, nl_pid, dev->ifindex, handle, 578 dump_filter_nlmsg, &filter_info); 579 if (ret) 580 goto out; 581 582 out: 583 free(tcinfo.handle_array); 584 return 0; 585 } 586 587 static int query_flow_dissector(struct bpf_attach_info *attach_info) 588 { 589 __u32 attach_flags; 590 __u32 prog_ids[1]; 591 __u32 prog_cnt; 592 int err; 593 int fd; 594 595 fd = open("/proc/self/ns/net", O_RDONLY); 596 if (fd < 0) { 597 p_err("can't open /proc/self/ns/net: %s", 598 strerror(errno)); 599 return -1; 600 } 601 prog_cnt = ARRAY_SIZE(prog_ids); 602 err = bpf_prog_query(fd, BPF_FLOW_DISSECTOR, 0, 603 &attach_flags, prog_ids, &prog_cnt); 604 close(fd); 605 if (err) { 606 if (errno == EINVAL) { 607 /* Older kernel's don't support querying 608 * flow dissector programs. 609 */ 610 errno = 0; 611 return 0; 612 } 613 p_err("can't query prog: %s", strerror(errno)); 614 return -1; 615 } 616 617 if (prog_cnt == 1) 618 attach_info->flow_dissector_id = prog_ids[0]; 619 620 return 0; 621 } 622 623 static int net_parse_dev(int *argc, char ***argv) 624 { 625 int ifindex; 626 627 if (is_prefix(**argv, "dev")) { 628 NEXT_ARGP(); 629 630 ifindex = if_nametoindex(**argv); 631 if (!ifindex) 632 p_err("invalid devname %s", **argv); 633 634 NEXT_ARGP(); 635 } else { 636 p_err("expected 'dev', got: '%s'?", **argv); 637 return -1; 638 } 639 640 return ifindex; 641 } 642 643 static int do_attach_detach_xdp(int progfd, enum net_attach_type attach_type, 644 int ifindex, bool overwrite) 645 { 646 __u32 flags = 0; 647 648 if (!overwrite) 649 flags = XDP_FLAGS_UPDATE_IF_NOEXIST; 650 if (attach_type == NET_ATTACH_TYPE_XDP_GENERIC) 651 flags |= XDP_FLAGS_SKB_MODE; 652 if (attach_type == NET_ATTACH_TYPE_XDP_DRIVER) 653 flags |= XDP_FLAGS_DRV_MODE; 654 if (attach_type == NET_ATTACH_TYPE_XDP_OFFLOAD) 655 flags |= XDP_FLAGS_HW_MODE; 656 657 return bpf_xdp_attach(ifindex, progfd, flags, NULL); 658 } 659 660 static int get_tcx_type(enum net_attach_type attach_type) 661 { 662 switch (attach_type) { 663 case NET_ATTACH_TYPE_TCX_INGRESS: 664 return BPF_TCX_INGRESS; 665 case NET_ATTACH_TYPE_TCX_EGRESS: 666 return BPF_TCX_EGRESS; 667 default: 668 return -1; 669 } 670 } 671 672 static int do_attach_tcx(int progfd, enum net_attach_type attach_type, int ifindex, bool prepend) 673 { 674 int type = get_tcx_type(attach_type); 675 676 if (prepend) { 677 LIBBPF_OPTS(bpf_prog_attach_opts, opts, 678 .flags = BPF_F_BEFORE 679 ); 680 return bpf_prog_attach_opts(progfd, ifindex, type, &opts); 681 } 682 return bpf_prog_attach(progfd, ifindex, type, 0); 683 } 684 685 static int do_detach_tcx(int targetfd, enum net_attach_type attach_type) 686 { 687 int type = get_tcx_type(attach_type); 688 689 return bpf_prog_detach(targetfd, type); 690 } 691 692 static int do_attach(int argc, char **argv) 693 { 694 enum net_attach_type attach_type; 695 int progfd, ifindex, err = 0; 696 bool overwrite = false; 697 bool prepend = false; 698 699 /* parse attach args */ 700 if (!REQ_ARGS(5)) 701 return -EINVAL; 702 703 attach_type = parse_attach_type(*argv); 704 if (attach_type == net_attach_type_size) { 705 p_err("invalid net attach/detach type: %s", *argv); 706 return -EINVAL; 707 } 708 NEXT_ARG(); 709 710 progfd = prog_parse_fd(&argc, &argv); 711 if (progfd < 0) 712 return -EINVAL; 713 714 ifindex = net_parse_dev(&argc, &argv); 715 if (ifindex < 1) { 716 err = -EINVAL; 717 goto cleanup; 718 } 719 720 if (argc) { 721 if (is_prefix(*argv, "overwrite")) { 722 if (attach_type != NET_ATTACH_TYPE_XDP && 723 attach_type != NET_ATTACH_TYPE_XDP_GENERIC && 724 attach_type != NET_ATTACH_TYPE_XDP_DRIVER && 725 attach_type != NET_ATTACH_TYPE_XDP_OFFLOAD) { 726 p_err("'overwrite' is only supported for xdp types"); 727 err = -EINVAL; 728 goto cleanup; 729 } 730 overwrite = true; 731 } else if (is_prefix(*argv, "prepend")) { 732 if (attach_type != NET_ATTACH_TYPE_TCX_INGRESS && 733 attach_type != NET_ATTACH_TYPE_TCX_EGRESS) { 734 p_err("'prepend' is only supported for tcx_ingress/tcx_egress"); 735 err = -EINVAL; 736 goto cleanup; 737 } 738 prepend = true; 739 } else { 740 p_err("expected 'overwrite' or 'prepend', got: '%s'?", *argv); 741 err = -EINVAL; 742 goto cleanup; 743 } 744 } 745 746 switch (attach_type) { 747 /* attach xdp prog */ 748 case NET_ATTACH_TYPE_XDP: 749 case NET_ATTACH_TYPE_XDP_GENERIC: 750 case NET_ATTACH_TYPE_XDP_DRIVER: 751 case NET_ATTACH_TYPE_XDP_OFFLOAD: 752 err = do_attach_detach_xdp(progfd, attach_type, ifindex, overwrite); 753 break; 754 /* attach tcx prog */ 755 case NET_ATTACH_TYPE_TCX_INGRESS: 756 case NET_ATTACH_TYPE_TCX_EGRESS: 757 err = do_attach_tcx(progfd, attach_type, ifindex, prepend); 758 break; 759 default: 760 break; 761 } 762 763 if (err) { 764 p_err("interface %s attach failed: %s", 765 attach_type_strings[attach_type], strerror(-err)); 766 goto cleanup; 767 } 768 769 if (json_output) 770 jsonw_null(json_wtr); 771 cleanup: 772 close(progfd); 773 return err; 774 } 775 776 static int do_detach(int argc, char **argv) 777 { 778 enum net_attach_type attach_type; 779 int progfd, ifindex, err = 0; 780 781 /* parse detach args */ 782 if (!REQ_ARGS(3)) 783 return -EINVAL; 784 785 attach_type = parse_attach_type(*argv); 786 if (attach_type == net_attach_type_size) { 787 p_err("invalid net attach/detach type: %s", *argv); 788 return -EINVAL; 789 } 790 NEXT_ARG(); 791 792 ifindex = net_parse_dev(&argc, &argv); 793 if (ifindex < 1) 794 return -EINVAL; 795 796 switch (attach_type) { 797 /* detach xdp prog */ 798 case NET_ATTACH_TYPE_XDP: 799 case NET_ATTACH_TYPE_XDP_GENERIC: 800 case NET_ATTACH_TYPE_XDP_DRIVER: 801 case NET_ATTACH_TYPE_XDP_OFFLOAD: 802 progfd = -1; 803 err = do_attach_detach_xdp(progfd, attach_type, ifindex, NULL); 804 break; 805 /* detach tcx prog */ 806 case NET_ATTACH_TYPE_TCX_INGRESS: 807 case NET_ATTACH_TYPE_TCX_EGRESS: 808 err = do_detach_tcx(ifindex, attach_type); 809 break; 810 default: 811 break; 812 } 813 814 if (err < 0) { 815 p_err("interface %s detach failed: %s", 816 attach_type_strings[attach_type], strerror(-err)); 817 return err; 818 } 819 820 if (json_output) 821 jsonw_null(json_wtr); 822 823 return 0; 824 } 825 826 static int netfilter_link_compar(const void *a, const void *b) 827 { 828 const struct bpf_link_info *nfa = a; 829 const struct bpf_link_info *nfb = b; 830 int delta; 831 832 delta = nfa->netfilter.pf - nfb->netfilter.pf; 833 if (delta) 834 return delta; 835 836 delta = nfa->netfilter.hooknum - nfb->netfilter.hooknum; 837 if (delta) 838 return delta; 839 840 if (nfa->netfilter.priority < nfb->netfilter.priority) 841 return -1; 842 if (nfa->netfilter.priority > nfb->netfilter.priority) 843 return 1; 844 845 return nfa->netfilter.flags - nfb->netfilter.flags; 846 } 847 848 static void show_link_netfilter(void) 849 { 850 unsigned int nf_link_len = 0, nf_link_count = 0; 851 struct bpf_link_info *nf_link_info = NULL; 852 __u32 id = 0; 853 854 while (true) { 855 struct bpf_link_info info; 856 int fd, err; 857 __u32 len; 858 859 err = bpf_link_get_next_id(id, &id); 860 if (err) { 861 if (errno == ENOENT) 862 break; 863 p_err("can't get next link: %s (id %u)", strerror(errno), id); 864 break; 865 } 866 867 fd = bpf_link_get_fd_by_id(id); 868 if (fd < 0) { 869 p_err("can't get link by id (%u): %s", id, strerror(errno)); 870 continue; 871 } 872 873 memset(&info, 0, sizeof(info)); 874 len = sizeof(info); 875 876 err = bpf_link_get_info_by_fd(fd, &info, &len); 877 878 close(fd); 879 880 if (err) { 881 p_err("can't get link info for fd %d: %s", fd, strerror(errno)); 882 continue; 883 } 884 885 if (info.type != BPF_LINK_TYPE_NETFILTER) 886 continue; 887 888 if (nf_link_count >= nf_link_len) { 889 static const unsigned int max_link_count = INT_MAX / sizeof(info); 890 struct bpf_link_info *expand; 891 892 if (nf_link_count > max_link_count) { 893 p_err("cannot handle more than %u links\n", max_link_count); 894 break; 895 } 896 897 nf_link_len += 16; 898 899 expand = realloc(nf_link_info, nf_link_len * sizeof(info)); 900 if (!expand) { 901 p_err("realloc: %s", strerror(errno)); 902 break; 903 } 904 905 nf_link_info = expand; 906 } 907 908 nf_link_info[nf_link_count] = info; 909 nf_link_count++; 910 } 911 912 if (!nf_link_info) 913 return; 914 915 qsort(nf_link_info, nf_link_count, sizeof(*nf_link_info), netfilter_link_compar); 916 917 for (id = 0; id < nf_link_count; id++) { 918 NET_START_OBJECT; 919 if (json_output) 920 netfilter_dump_json(&nf_link_info[id], json_wtr); 921 else 922 netfilter_dump_plain(&nf_link_info[id]); 923 924 NET_DUMP_UINT("id", " prog_id %u", nf_link_info[id].prog_id); 925 NET_END_OBJECT; 926 } 927 928 free(nf_link_info); 929 } 930 931 static int do_show(int argc, char **argv) 932 { 933 struct bpf_attach_info attach_info = {}; 934 int i, sock, ret, filter_idx = -1; 935 struct bpf_netdev_t dev_array; 936 unsigned int nl_pid = 0; 937 char err_buf[256]; 938 939 if (argc == 2) { 940 filter_idx = net_parse_dev(&argc, &argv); 941 if (filter_idx < 1) 942 return -1; 943 } else if (argc != 0) { 944 usage(); 945 } 946 947 ret = query_flow_dissector(&attach_info); 948 if (ret) 949 return -1; 950 951 sock = netlink_open(&nl_pid); 952 if (sock < 0) { 953 fprintf(stderr, "failed to open netlink sock\n"); 954 return -1; 955 } 956 957 dev_array.devices = NULL; 958 dev_array.used_len = 0; 959 dev_array.array_len = 0; 960 dev_array.filter_idx = filter_idx; 961 962 if (json_output) 963 jsonw_start_array(json_wtr); 964 NET_START_OBJECT; 965 NET_START_ARRAY("xdp", "%s:\n"); 966 ret = netlink_get_link(sock, nl_pid, dump_link_nlmsg, &dev_array); 967 NET_END_ARRAY("\n"); 968 969 if (!ret) { 970 NET_START_ARRAY("tc", "%s:\n"); 971 for (i = 0; i < dev_array.used_len; i++) { 972 show_dev_tc_bpf(&dev_array.devices[i]); 973 ret = show_dev_tc_bpf_classic(sock, nl_pid, 974 &dev_array.devices[i]); 975 if (ret) 976 break; 977 } 978 NET_END_ARRAY("\n"); 979 } 980 981 NET_START_ARRAY("flow_dissector", "%s:\n"); 982 if (attach_info.flow_dissector_id > 0) 983 NET_DUMP_UINT("id", "id %u", attach_info.flow_dissector_id); 984 NET_END_ARRAY("\n"); 985 986 NET_START_ARRAY("netfilter", "%s:\n"); 987 show_link_netfilter(); 988 NET_END_ARRAY("\n"); 989 990 NET_END_OBJECT; 991 if (json_output) 992 jsonw_end_array(json_wtr); 993 994 if (ret) { 995 if (json_output) 996 jsonw_null(json_wtr); 997 libbpf_strerror(ret, err_buf, sizeof(err_buf)); 998 fprintf(stderr, "Error: %s\n", err_buf); 999 } 1000 free(dev_array.devices); 1001 close(sock); 1002 return ret; 1003 } 1004 1005 static int do_help(int argc, char **argv) 1006 { 1007 if (json_output) { 1008 jsonw_null(json_wtr); 1009 return 0; 1010 } 1011 1012 fprintf(stderr, 1013 "Usage: %1$s %2$s { show | list } [dev <devname>]\n" 1014 " %1$s %2$s attach ATTACH_TYPE PROG dev <devname> [ overwrite | prepend ]\n" 1015 " %1$s %2$s detach ATTACH_TYPE dev <devname>\n" 1016 " %1$s %2$s help\n" 1017 "\n" 1018 " " HELP_SPEC_PROGRAM "\n" 1019 " ATTACH_TYPE := { xdp | xdpgeneric | xdpdrv | xdpoffload | tcx_ingress\n" 1020 " | tcx_egress }\n" 1021 " " HELP_SPEC_OPTIONS " }\n" 1022 "\n" 1023 "Note: Only xdp, tcx, tc, netkit, flow_dissector and netfilter attachments\n" 1024 " are currently supported.\n" 1025 " For progs attached to cgroups, use \"bpftool cgroup\"\n" 1026 " to dump program attachments. For program types\n" 1027 " sk_{filter,skb,msg,reuseport} and lwt/seg6, please\n" 1028 " consult iproute2.\n" 1029 "", 1030 bin_name, argv[-2]); 1031 1032 return 0; 1033 } 1034 1035 static const struct cmd cmds[] = { 1036 { "show", do_show }, 1037 { "list", do_show }, 1038 { "attach", do_attach }, 1039 { "detach", do_detach }, 1040 { "help", do_help }, 1041 { 0 } 1042 }; 1043 1044 int do_net(int argc, char **argv) 1045 { 1046 return cmd_select(cmds, argc, argv, do_help); 1047 } 1048