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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
31struct ip_devname_ifindex {
32 char devname[64];
33 int ifindex;
34};
35
36struct bpf_netdev_t {
37 struct ip_devname_ifindex *devices;
38 int used_len;
39 int array_len;
40 int filter_idx;
41};
42
43struct tc_kind_handle {
44 char kind[64];
45 int handle;
46};
47
48struct bpf_tcinfo_t {
49 struct tc_kind_handle *handle_array;
50 int used_len;
51 int array_len;
52 bool is_qdisc;
53};
54
55struct bpf_filter_t {
56 const char *kind;
57 const char *devname;
58 int ifindex;
59};
60
61struct bpf_attach_info {
62 __u32 flow_dissector_id;
63};
64
65enum 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
72static 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
79const size_t net_attach_type_size = ARRAY_SIZE(attach_type_strings);
80
81static 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
94typedef int (*dump_nlmsg_t)(void *cookie, void *msg, struct nlattr **tb);
95
96typedef int (*__dump_nlmsg_t)(struct nlmsghdr *nlmsg, dump_nlmsg_t, void *cookie);
97
98static 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
136cleanup:
137 close(sock);
138 return ret;
139}
140
141static 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;
195done:
196 return ret;
197}
198
199static 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
215static 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
238static 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
254static 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
277static 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
293static 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
317static 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
332static 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
354static 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
383static 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
417static 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
425static 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
481out:
482 free(tcinfo.handle_array);
483 return 0;
484}
485
486static 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
522static 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
542static 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
559static 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);
608cleanup:
609 close(progfd);
610 return err;
611}
612
613static 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
650static int do_show(int argc, char **argv)
651{
652 struct bpf_attach_info attach_info = {};
653 int i, sock, ret, filter_idx = -1;
654 struct bpf_netdev_t dev_array;
655 unsigned int nl_pid = 0;
656 char err_buf[256];
657
658 if (argc == 2) {
659 filter_idx = net_parse_dev(&argc, &argv);
660 if (filter_idx < 1)
661 return -1;
662 } else if (argc != 0) {
663 usage();
664 }
665
666 ret = query_flow_dissector(&attach_info);
667 if (ret)
668 return -1;
669
670 sock = netlink_open(&nl_pid);
671 if (sock < 0) {
672 fprintf(stderr, "failed to open netlink sock\n");
673 return -1;
674 }
675
676 dev_array.devices = NULL;
677 dev_array.used_len = 0;
678 dev_array.array_len = 0;
679 dev_array.filter_idx = filter_idx;
680
681 if (json_output)
682 jsonw_start_array(json_wtr);
683 NET_START_OBJECT;
684 NET_START_ARRAY("xdp", "%s:\n");
685 ret = netlink_get_link(sock, nl_pid, dump_link_nlmsg, &dev_array);
686 NET_END_ARRAY("\n");
687
688 if (!ret) {
689 NET_START_ARRAY("tc", "%s:\n");
690 for (i = 0; i < dev_array.used_len; i++) {
691 ret = show_dev_tc_bpf(sock, nl_pid,
692 &dev_array.devices[i]);
693 if (ret)
694 break;
695 }
696 NET_END_ARRAY("\n");
697 }
698
699 NET_START_ARRAY("flow_dissector", "%s:\n");
700 if (attach_info.flow_dissector_id > 0)
701 NET_DUMP_UINT("id", "id %u", attach_info.flow_dissector_id);
702 NET_END_ARRAY("\n");
703
704 NET_END_OBJECT;
705 if (json_output)
706 jsonw_end_array(json_wtr);
707
708 if (ret) {
709 if (json_output)
710 jsonw_null(json_wtr);
711 libbpf_strerror(ret, err_buf, sizeof(err_buf));
712 fprintf(stderr, "Error: %s\n", err_buf);
713 }
714 free(dev_array.devices);
715 close(sock);
716 return ret;
717}
718
719static int do_help(int argc, char **argv)
720{
721 if (json_output) {
722 jsonw_null(json_wtr);
723 return 0;
724 }
725
726 fprintf(stderr,
727 "Usage: %1$s %2$s { show | list } [dev <devname>]\n"
728 " %1$s %2$s attach ATTACH_TYPE PROG dev <devname> [ overwrite ]\n"
729 " %1$s %2$s detach ATTACH_TYPE dev <devname>\n"
730 " %1$s %2$s help\n"
731 "\n"
732 " " HELP_SPEC_PROGRAM "\n"
733 " ATTACH_TYPE := { xdp | xdpgeneric | xdpdrv | xdpoffload }\n"
734 " " HELP_SPEC_OPTIONS " }\n"
735 "\n"
736 "Note: Only xdp and tc attachments are supported now.\n"
737 " For progs attached to cgroups, use \"bpftool cgroup\"\n"
738 " to dump program attachments. For program types\n"
739 " sk_{filter,skb,msg,reuseport} and lwt/seg6, please\n"
740 " consult iproute2.\n"
741 "",
742 bin_name, argv[-2]);
743
744 return 0;
745}
746
747static const struct cmd cmds[] = {
748 { "show", do_show },
749 { "list", do_show },
750 { "attach", do_attach },
751 { "detach", do_detach },
752 { "help", do_help },
753 { 0 }
754};
755
756int do_net(int argc, char **argv)
757{
758 return cmd_select(cmds, argc, argv, do_help);
759}