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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
29struct ip_devname_ifindex {
30 char devname[64];
31 int ifindex;
32};
33
34struct bpf_netdev_t {
35 struct ip_devname_ifindex *devices;
36 int used_len;
37 int array_len;
38 int filter_idx;
39};
40
41struct tc_kind_handle {
42 char kind[64];
43 int handle;
44};
45
46struct bpf_tcinfo_t {
47 struct tc_kind_handle *handle_array;
48 int used_len;
49 int array_len;
50 bool is_qdisc;
51};
52
53struct bpf_filter_t {
54 const char *kind;
55 const char *devname;
56 int ifindex;
57};
58
59struct bpf_attach_info {
60 __u32 flow_dissector_id;
61};
62
63enum 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
70static 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
77const size_t net_attach_type_size = ARRAY_SIZE(attach_type_strings);
78
79static 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
92typedef int (*dump_nlmsg_t)(void *cookie, void *msg, struct nlattr **tb);
93
94typedef int (*__dump_nlmsg_t)(struct nlmsghdr *nlmsg, dump_nlmsg_t, void *cookie);
95
96static 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
134cleanup:
135 close(sock);
136 return ret;
137}
138
139static 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;
193done:
194 return ret;
195}
196
197static 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
213static 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
236static 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
252static 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
275static 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
291static 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
315static 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
330static 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
352static 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
381static 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
415static 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
423static 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
479out:
480 free(tcinfo.handle_array);
481 return 0;
482}
483
484static 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
520static 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
540static 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_set_link_xdp_fd(ifindex, progfd, flags);
555}
556
557static 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);
606cleanup:
607 close(progfd);
608 return err;
609}
610
611static 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
648static 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
717static 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 "\n"
733 "Note: Only xdp and tc attachments are supported now.\n"
734 " For progs attached to cgroups, use \"bpftool cgroup\"\n"
735 " to dump program attachments. For program types\n"
736 " sk_{filter,skb,msg,reuseport} and lwt/seg6, please\n"
737 " consult iproute2.\n"
738 "",
739 bin_name, argv[-2]);
740
741 return 0;
742}
743
744static const struct cmd cmds[] = {
745 { "show", do_show },
746 { "list", do_show },
747 { "attach", do_attach },
748 { "detach", do_detach },
749 { "help", do_help },
750 { 0 }
751};
752
753int do_net(int argc, char **argv)
754{
755 return cmd_select(cmds, argc, argv, do_help);
756}