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 static const char * const attach_loc_strings[] = {
80 [BPF_TCX_INGRESS] = "tcx/ingress",
81 [BPF_TCX_EGRESS] = "tcx/egress",
82 [BPF_NETKIT_PRIMARY] = "netkit/primary",
83 [BPF_NETKIT_PEER] = "netkit/peer",
84 };
85
86 const size_t net_attach_type_size = ARRAY_SIZE(attach_type_strings);
87
88 static enum net_attach_type parse_attach_type(const char *str)
89 {
90 enum net_attach_type type;
91
92 for (type = 0; type < net_attach_type_size; type++) {
93 if (attach_type_strings[type] &&
94 is_prefix(str, attach_type_strings[type]))
95 return type;
96 }
97
98 return net_attach_type_size;
99 }
100
101 typedef int (*dump_nlmsg_t)(void *cookie, void *msg, struct nlattr **tb);
102
103 typedef int (*__dump_nlmsg_t)(struct nlmsghdr *nlmsg, dump_nlmsg_t, void *cookie);
104
105 static int netlink_open(__u32 *nl_pid)
106 {
107 struct sockaddr_nl sa;
108 socklen_t addrlen;
109 int one = 1, ret;
110 int sock;
111
112 memset(&sa, 0, sizeof(sa));
113 sa.nl_family = AF_NETLINK;
114
115 sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
116 if (sock < 0)
117 return -errno;
118
119 if (setsockopt(sock, SOL_NETLINK, NETLINK_EXT_ACK,
120 &one, sizeof(one)) < 0) {
121 p_err("Netlink error reporting not supported");
122 }
123
124 if (bind(sock, (struct sockaddr *)&sa, sizeof(sa)) < 0) {
125 ret = -errno;
126 goto cleanup;
127 }
128
129 addrlen = sizeof(sa);
130 if (getsockname(sock, (struct sockaddr *)&sa, &addrlen) < 0) {
131 ret = -errno;
132 goto cleanup;
133 }
134
135 if (addrlen != sizeof(sa)) {
136 ret = -LIBBPF_ERRNO__INTERNAL;
137 goto cleanup;
138 }
139
140 *nl_pid = sa.nl_pid;
141 return sock;
142
143 cleanup:
144 close(sock);
145 return ret;
146 }
147
148 static int netlink_recv(int sock, __u32 nl_pid, __u32 seq,
149 __dump_nlmsg_t _fn, dump_nlmsg_t fn,
150 void *cookie)
151 {
152 bool multipart = true;
153 struct nlmsgerr *err;
154 struct nlmsghdr *nh;
155 char buf[4096];
156 int len, ret;
157
158 while (multipart) {
159 multipart = false;
160 len = recv(sock, buf, sizeof(buf), 0);
161 if (len < 0) {
162 ret = -errno;
163 goto done;
164 }
165
166 if (len == 0)
167 break;
168
169 for (nh = (struct nlmsghdr *)buf; NLMSG_OK(nh, (unsigned int)len);
170 nh = NLMSG_NEXT(nh, len)) {
171 if (nh->nlmsg_pid != nl_pid) {
172 ret = -LIBBPF_ERRNO__WRNGPID;
173 goto done;
174 }
175 if (nh->nlmsg_seq != seq) {
176 ret = -LIBBPF_ERRNO__INVSEQ;
177 goto done;
178 }
179 if (nh->nlmsg_flags & NLM_F_MULTI)
180 multipart = true;
181 switch (nh->nlmsg_type) {
182 case NLMSG_ERROR:
183 err = (struct nlmsgerr *)NLMSG_DATA(nh);
184 if (!err->error)
185 continue;
186 ret = err->error;
187 libbpf_nla_dump_errormsg(nh);
188 goto done;
189 case NLMSG_DONE:
190 return 0;
191 default:
192 break;
193 }
194 if (_fn) {
195 ret = _fn(nh, fn, cookie);
196 if (ret)
197 return ret;
198 }
199 }
200 }
201 ret = 0;
202 done:
203 return ret;
204 }
205
206 static int __dump_class_nlmsg(struct nlmsghdr *nlh,
207 dump_nlmsg_t dump_class_nlmsg,
208 void *cookie)
209 {
210 struct nlattr *tb[TCA_MAX + 1], *attr;
211 struct tcmsg *t = NLMSG_DATA(nlh);
212 int len;
213
214 len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*t));
215 attr = (struct nlattr *) ((void *) t + NLMSG_ALIGN(sizeof(*t)));
216 if (libbpf_nla_parse(tb, TCA_MAX, attr, len, NULL) != 0)
217 return -LIBBPF_ERRNO__NLPARSE;
218
219 return dump_class_nlmsg(cookie, t, tb);
220 }
221
222 static int netlink_get_class(int sock, unsigned int nl_pid, int ifindex,
223 dump_nlmsg_t dump_class_nlmsg, void *cookie)
224 {
225 struct {
226 struct nlmsghdr nlh;
227 struct tcmsg t;
228 } req = {
229 .nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg)),
230 .nlh.nlmsg_type = RTM_GETTCLASS,
231 .nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
232 .t.tcm_family = AF_UNSPEC,
233 .t.tcm_ifindex = ifindex,
234 };
235 int seq = time(NULL);
236
237 req.nlh.nlmsg_seq = seq;
238 if (send(sock, &req, req.nlh.nlmsg_len, 0) < 0)
239 return -errno;
240
241 return netlink_recv(sock, nl_pid, seq, __dump_class_nlmsg,
242 dump_class_nlmsg, cookie);
243 }
244
245 static int __dump_qdisc_nlmsg(struct nlmsghdr *nlh,
246 dump_nlmsg_t dump_qdisc_nlmsg,
247 void *cookie)
248 {
249 struct nlattr *tb[TCA_MAX + 1], *attr;
250 struct tcmsg *t = NLMSG_DATA(nlh);
251 int len;
252
253 len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*t));
254 attr = (struct nlattr *) ((void *) t + NLMSG_ALIGN(sizeof(*t)));
255 if (libbpf_nla_parse(tb, TCA_MAX, attr, len, NULL) != 0)
256 return -LIBBPF_ERRNO__NLPARSE;
257
258 return dump_qdisc_nlmsg(cookie, t, tb);
259 }
260
261 static int netlink_get_qdisc(int sock, unsigned int nl_pid, int ifindex,
262 dump_nlmsg_t dump_qdisc_nlmsg, void *cookie)
263 {
264 struct {
265 struct nlmsghdr nlh;
266 struct tcmsg t;
267 } req = {
268 .nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg)),
269 .nlh.nlmsg_type = RTM_GETQDISC,
270 .nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
271 .t.tcm_family = AF_UNSPEC,
272 .t.tcm_ifindex = ifindex,
273 };
274 int seq = time(NULL);
275
276 req.nlh.nlmsg_seq = seq;
277 if (send(sock, &req, req.nlh.nlmsg_len, 0) < 0)
278 return -errno;
279
280 return netlink_recv(sock, nl_pid, seq, __dump_qdisc_nlmsg,
281 dump_qdisc_nlmsg, cookie);
282 }
283
284 static int __dump_filter_nlmsg(struct nlmsghdr *nlh,
285 dump_nlmsg_t dump_filter_nlmsg,
286 void *cookie)
287 {
288 struct nlattr *tb[TCA_MAX + 1], *attr;
289 struct tcmsg *t = NLMSG_DATA(nlh);
290 int len;
291
292 len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*t));
293 attr = (struct nlattr *) ((void *) t + NLMSG_ALIGN(sizeof(*t)));
294 if (libbpf_nla_parse(tb, TCA_MAX, attr, len, NULL) != 0)
295 return -LIBBPF_ERRNO__NLPARSE;
296
297 return dump_filter_nlmsg(cookie, t, tb);
298 }
299
300 static int netlink_get_filter(int sock, unsigned int nl_pid, int ifindex, int handle,
301 dump_nlmsg_t dump_filter_nlmsg, void *cookie)
302 {
303 struct {
304 struct nlmsghdr nlh;
305 struct tcmsg t;
306 } req = {
307 .nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg)),
308 .nlh.nlmsg_type = RTM_GETTFILTER,
309 .nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
310 .t.tcm_family = AF_UNSPEC,
311 .t.tcm_ifindex = ifindex,
312 .t.tcm_parent = handle,
313 };
314 int seq = time(NULL);
315
316 req.nlh.nlmsg_seq = seq;
317 if (send(sock, &req, req.nlh.nlmsg_len, 0) < 0)
318 return -errno;
319
320 return netlink_recv(sock, nl_pid, seq, __dump_filter_nlmsg,
321 dump_filter_nlmsg, cookie);
322 }
323
324 static int __dump_link_nlmsg(struct nlmsghdr *nlh,
325 dump_nlmsg_t dump_link_nlmsg, void *cookie)
326 {
327 struct nlattr *tb[IFLA_MAX + 1], *attr;
328 struct ifinfomsg *ifi = NLMSG_DATA(nlh);
329 int len;
330
331 len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*ifi));
332 attr = (struct nlattr *) ((void *) ifi + NLMSG_ALIGN(sizeof(*ifi)));
333 if (libbpf_nla_parse(tb, IFLA_MAX, attr, len, NULL) != 0)
334 return -LIBBPF_ERRNO__NLPARSE;
335
336 return dump_link_nlmsg(cookie, ifi, tb);
337 }
338
339 static int netlink_get_link(int sock, unsigned int nl_pid,
340 dump_nlmsg_t dump_link_nlmsg, void *cookie)
341 {
342 struct {
343 struct nlmsghdr nlh;
344 struct ifinfomsg ifm;
345 } req = {
346 .nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg)),
347 .nlh.nlmsg_type = RTM_GETLINK,
348 .nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
349 .ifm.ifi_family = AF_PACKET,
350 };
351 int seq = time(NULL);
352
353 req.nlh.nlmsg_seq = seq;
354 if (send(sock, &req, req.nlh.nlmsg_len, 0) < 0)
355 return -errno;
356
357 return netlink_recv(sock, nl_pid, seq, __dump_link_nlmsg,
358 dump_link_nlmsg, cookie);
359 }
360
361 static int dump_link_nlmsg(void *cookie, void *msg, struct nlattr **tb)
362 {
363 struct bpf_netdev_t *netinfo = cookie;
364 struct ifinfomsg *ifinfo = msg;
365
366 if (netinfo->filter_idx > 0 && netinfo->filter_idx != ifinfo->ifi_index)
367 return 0;
368
369 if (netinfo->used_len == netinfo->array_len) {
370 netinfo->devices = realloc(netinfo->devices,
371 (netinfo->array_len + 16) *
372 sizeof(struct ip_devname_ifindex));
373 if (!netinfo->devices)
374 return -ENOMEM;
375
376 netinfo->array_len += 16;
377 }
378 netinfo->devices[netinfo->used_len].ifindex = ifinfo->ifi_index;
379 snprintf(netinfo->devices[netinfo->used_len].devname,
380 sizeof(netinfo->devices[netinfo->used_len].devname),
381 "%s",
382 tb[IFLA_IFNAME]
383 ? libbpf_nla_getattr_str(tb[IFLA_IFNAME])
384 : "");
385 netinfo->used_len++;
386
387 return do_xdp_dump(ifinfo, tb);
388 }
389
390 static int dump_class_qdisc_nlmsg(void *cookie, void *msg, struct nlattr **tb)
391 {
392 struct bpf_tcinfo_t *tcinfo = cookie;
393 struct tcmsg *info = msg;
394
395 if (tcinfo->is_qdisc) {
396 /* skip clsact qdisc */
397 if (tb[TCA_KIND] &&
398 strcmp(libbpf_nla_data(tb[TCA_KIND]), "clsact") == 0)
399 return 0;
400 if (info->tcm_handle == 0)
401 return 0;
402 }
403
404 if (tcinfo->used_len == tcinfo->array_len) {
405 tcinfo->handle_array = realloc(tcinfo->handle_array,
406 (tcinfo->array_len + 16) * sizeof(struct tc_kind_handle));
407 if (!tcinfo->handle_array)
408 return -ENOMEM;
409
410 tcinfo->array_len += 16;
411 }
412 tcinfo->handle_array[tcinfo->used_len].handle = info->tcm_handle;
413 snprintf(tcinfo->handle_array[tcinfo->used_len].kind,
414 sizeof(tcinfo->handle_array[tcinfo->used_len].kind),
415 "%s",
416 tb[TCA_KIND]
417 ? libbpf_nla_getattr_str(tb[TCA_KIND])
418 : "unknown");
419 tcinfo->used_len++;
420
421 return 0;
422 }
423
424 static int dump_filter_nlmsg(void *cookie, void *msg, struct nlattr **tb)
425 {
426 const struct bpf_filter_t *filter_info = cookie;
427
428 return do_filter_dump((struct tcmsg *)msg, tb, filter_info->kind,
429 filter_info->devname, filter_info->ifindex);
430 }
431
432 static int __show_dev_tc_bpf_name(__u32 id, char *name, size_t len)
433 {
434 struct bpf_prog_info info = {};
435 __u32 ilen = sizeof(info);
436 int fd, ret;
437
438 fd = bpf_prog_get_fd_by_id(id);
439 if (fd < 0)
440 return fd;
441 ret = bpf_obj_get_info_by_fd(fd, &info, &ilen);
442 if (ret < 0)
443 goto out;
444 ret = -ENOENT;
445 if (info.name[0]) {
446 get_prog_full_name(&info, fd, name, len);
447 ret = 0;
448 }
449 out:
450 close(fd);
451 return ret;
452 }
453
454 static void __show_dev_tc_bpf(const struct ip_devname_ifindex *dev,
455 const enum bpf_attach_type loc)
456 {
457 __u32 prog_flags[64] = {}, link_flags[64] = {}, i, j;
458 __u32 prog_ids[64] = {}, link_ids[64] = {};
459 LIBBPF_OPTS(bpf_prog_query_opts, optq);
460 char prog_name[MAX_PROG_FULL_NAME];
461 int ret;
462
463 optq.prog_ids = prog_ids;
464 optq.prog_attach_flags = prog_flags;
465 optq.link_ids = link_ids;
466 optq.link_attach_flags = link_flags;
467 optq.count = ARRAY_SIZE(prog_ids);
468
469 ret = bpf_prog_query_opts(dev->ifindex, loc, &optq);
470 if (ret)
471 return;
472 for (i = 0; i < optq.count; i++) {
473 NET_START_OBJECT;
474 NET_DUMP_STR("devname", "%s", dev->devname);
475 NET_DUMP_UINT("ifindex", "(%u)", dev->ifindex);
476 NET_DUMP_STR("kind", " %s", attach_loc_strings[loc]);
477 ret = __show_dev_tc_bpf_name(prog_ids[i], prog_name,
478 sizeof(prog_name));
479 if (!ret)
480 NET_DUMP_STR("name", " %s", prog_name);
481 NET_DUMP_UINT("prog_id", " prog_id %u ", prog_ids[i]);
482 if (prog_flags[i] || json_output) {
483 NET_START_ARRAY("prog_flags", "%s ");
484 for (j = 0; prog_flags[i] && j < 32; j++) {
485 if (!(prog_flags[i] & (1 << j)))
486 continue;
487 NET_DUMP_UINT_ONLY(1 << j);
488 }
489 NET_END_ARRAY("");
490 }
491 if (link_ids[i] || json_output) {
492 NET_DUMP_UINT("link_id", "link_id %u ", link_ids[i]);
493 if (link_flags[i] || json_output) {
494 NET_START_ARRAY("link_flags", "%s ");
495 for (j = 0; link_flags[i] && j < 32; j++) {
496 if (!(link_flags[i] & (1 << j)))
497 continue;
498 NET_DUMP_UINT_ONLY(1 << j);
499 }
500 NET_END_ARRAY("");
501 }
502 }
503 NET_END_OBJECT_FINAL;
504 }
505 }
506
507 static void show_dev_tc_bpf(struct ip_devname_ifindex *dev)
508 {
509 __show_dev_tc_bpf(dev, BPF_TCX_INGRESS);
510 __show_dev_tc_bpf(dev, BPF_TCX_EGRESS);
511
512 __show_dev_tc_bpf(dev, BPF_NETKIT_PRIMARY);
513 __show_dev_tc_bpf(dev, BPF_NETKIT_PEER);
514 }
515
516 static int show_dev_tc_bpf_classic(int sock, unsigned int nl_pid,
517 struct ip_devname_ifindex *dev)
518 {
519 struct bpf_filter_t filter_info;
520 struct bpf_tcinfo_t tcinfo;
521 int i, handle, ret = 0;
522
523 tcinfo.handle_array = NULL;
524 tcinfo.used_len = 0;
525 tcinfo.array_len = 0;
526
527 tcinfo.is_qdisc = false;
528 ret = netlink_get_class(sock, nl_pid, dev->ifindex,
529 dump_class_qdisc_nlmsg, &tcinfo);
530 if (ret)
531 goto out;
532
533 tcinfo.is_qdisc = true;
534 ret = netlink_get_qdisc(sock, nl_pid, dev->ifindex,
535 dump_class_qdisc_nlmsg, &tcinfo);
536 if (ret)
537 goto out;
538
539 filter_info.devname = dev->devname;
540 filter_info.ifindex = dev->ifindex;
541 for (i = 0; i < tcinfo.used_len; i++) {
542 filter_info.kind = tcinfo.handle_array[i].kind;
543 ret = netlink_get_filter(sock, nl_pid, dev->ifindex,
544 tcinfo.handle_array[i].handle,
545 dump_filter_nlmsg, &filter_info);
546 if (ret)
547 goto out;
548 }
549
550 /* root, ingress and egress handle */
551 handle = TC_H_ROOT;
552 filter_info.kind = "root";
553 ret = netlink_get_filter(sock, nl_pid, dev->ifindex, handle,
554 dump_filter_nlmsg, &filter_info);
555 if (ret)
556 goto out;
557
558 handle = TC_H_MAKE(TC_H_CLSACT, TC_H_MIN_INGRESS);
559 filter_info.kind = "clsact/ingress";
560 ret = netlink_get_filter(sock, nl_pid, dev->ifindex, handle,
561 dump_filter_nlmsg, &filter_info);
562 if (ret)
563 goto out;
564
565 handle = TC_H_MAKE(TC_H_CLSACT, TC_H_MIN_EGRESS);
566 filter_info.kind = "clsact/egress";
567 ret = netlink_get_filter(sock, nl_pid, dev->ifindex, handle,
568 dump_filter_nlmsg, &filter_info);
569 if (ret)
570 goto out;
571
572 out:
573 free(tcinfo.handle_array);
574 return 0;
575 }
576
577 static int query_flow_dissector(struct bpf_attach_info *attach_info)
578 {
579 __u32 attach_flags;
580 __u32 prog_ids[1];
581 __u32 prog_cnt;
582 int err;
583 int fd;
584
585 fd = open("/proc/self/ns/net", O_RDONLY);
586 if (fd < 0) {
587 p_err("can't open /proc/self/ns/net: %s",
588 strerror(errno));
589 return -1;
590 }
591 prog_cnt = ARRAY_SIZE(prog_ids);
592 err = bpf_prog_query(fd, BPF_FLOW_DISSECTOR, 0,
593 &attach_flags, prog_ids, &prog_cnt);
594 close(fd);
595 if (err) {
596 if (errno == EINVAL) {
597 /* Older kernel's don't support querying
598 * flow dissector programs.
599 */
600 errno = 0;
601 return 0;
602 }
603 p_err("can't query prog: %s", strerror(errno));
604 return -1;
605 }
606
607 if (prog_cnt == 1)
608 attach_info->flow_dissector_id = prog_ids[0];
609
610 return 0;
611 }
612
613 static int net_parse_dev(int *argc, char ***argv)
614 {
615 int ifindex;
616
617 if (is_prefix(**argv, "dev")) {
618 NEXT_ARGP();
619
620 ifindex = if_nametoindex(**argv);
621 if (!ifindex)
622 p_err("invalid devname %s", **argv);
623
624 NEXT_ARGP();
625 } else {
626 p_err("expected 'dev', got: '%s'?", **argv);
627 return -1;
628 }
629
630 return ifindex;
631 }
632
633 static int do_attach_detach_xdp(int progfd, enum net_attach_type attach_type,
634 int ifindex, bool overwrite)
635 {
636 __u32 flags = 0;
637
638 if (!overwrite)
639 flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
640 if (attach_type == NET_ATTACH_TYPE_XDP_GENERIC)
641 flags |= XDP_FLAGS_SKB_MODE;
642 if (attach_type == NET_ATTACH_TYPE_XDP_DRIVER)
643 flags |= XDP_FLAGS_DRV_MODE;
644 if (attach_type == NET_ATTACH_TYPE_XDP_OFFLOAD)
645 flags |= XDP_FLAGS_HW_MODE;
646
647 return bpf_xdp_attach(ifindex, progfd, flags, NULL);
648 }
649
650 static int do_attach(int argc, char **argv)
651 {
652 enum net_attach_type attach_type;
653 int progfd, ifindex, err = 0;
654 bool overwrite = false;
655
656 /* parse attach args */
657 if (!REQ_ARGS(5))
658 return -EINVAL;
659
660 attach_type = parse_attach_type(*argv);
661 if (attach_type == net_attach_type_size) {
662 p_err("invalid net attach/detach type: %s", *argv);
663 return -EINVAL;
664 }
665 NEXT_ARG();
666
667 progfd = prog_parse_fd(&argc, &argv);
668 if (progfd < 0)
669 return -EINVAL;
670
671 ifindex = net_parse_dev(&argc, &argv);
672 if (ifindex < 1) {
673 err = -EINVAL;
674 goto cleanup;
675 }
676
677 if (argc) {
678 if (is_prefix(*argv, "overwrite")) {
679 overwrite = true;
680 } else {
681 p_err("expected 'overwrite', got: '%s'?", *argv);
682 err = -EINVAL;
683 goto cleanup;
684 }
685 }
686
687 /* attach xdp prog */
688 if (is_prefix("xdp", attach_type_strings[attach_type]))
689 err = do_attach_detach_xdp(progfd, attach_type, ifindex,
690 overwrite);
691 if (err) {
692 p_err("interface %s attach failed: %s",
693 attach_type_strings[attach_type], strerror(-err));
694 goto cleanup;
695 }
696
697 if (json_output)
698 jsonw_null(json_wtr);
699 cleanup:
700 close(progfd);
701 return err;
702 }
703
704 static int do_detach(int argc, char **argv)
705 {
706 enum net_attach_type attach_type;
707 int progfd, ifindex, err = 0;
708
709 /* parse detach args */
710 if (!REQ_ARGS(3))
711 return -EINVAL;
712
713 attach_type = parse_attach_type(*argv);
714 if (attach_type == net_attach_type_size) {
715 p_err("invalid net attach/detach type: %s", *argv);
716 return -EINVAL;
717 }
718 NEXT_ARG();
719
720 ifindex = net_parse_dev(&argc, &argv);
721 if (ifindex < 1)
722 return -EINVAL;
723
724 /* detach xdp prog */
725 progfd = -1;
726 if (is_prefix("xdp", attach_type_strings[attach_type]))
727 err = do_attach_detach_xdp(progfd, attach_type, ifindex, NULL);
728
729 if (err < 0) {
730 p_err("interface %s detach failed: %s",
731 attach_type_strings[attach_type], strerror(-err));
732 return err;
733 }
734
735 if (json_output)
736 jsonw_null(json_wtr);
737
738 return 0;
739 }
740
741 static int netfilter_link_compar(const void *a, const void *b)
742 {
743 const struct bpf_link_info *nfa = a;
744 const struct bpf_link_info *nfb = b;
745 int delta;
746
747 delta = nfa->netfilter.pf - nfb->netfilter.pf;
748 if (delta)
749 return delta;
750
751 delta = nfa->netfilter.hooknum - nfb->netfilter.hooknum;
752 if (delta)
753 return delta;
754
755 if (nfa->netfilter.priority < nfb->netfilter.priority)
756 return -1;
757 if (nfa->netfilter.priority > nfb->netfilter.priority)
758 return 1;
759
760 return nfa->netfilter.flags - nfb->netfilter.flags;
761 }
762
763 static void show_link_netfilter(void)
764 {
765 unsigned int nf_link_len = 0, nf_link_count = 0;
766 struct bpf_link_info *nf_link_info = NULL;
767 __u32 id = 0;
768
769 while (true) {
770 struct bpf_link_info info;
771 int fd, err;
772 __u32 len;
773
774 err = bpf_link_get_next_id(id, &id);
775 if (err) {
776 if (errno == ENOENT)
777 break;
778 p_err("can't get next link: %s (id %d)", strerror(errno), id);
779 break;
780 }
781
782 fd = bpf_link_get_fd_by_id(id);
783 if (fd < 0) {
784 p_err("can't get link by id (%u): %s", id, strerror(errno));
785 continue;
786 }
787
788 memset(&info, 0, sizeof(info));
789 len = sizeof(info);
790
791 err = bpf_link_get_info_by_fd(fd, &info, &len);
792
793 close(fd);
794
795 if (err) {
796 p_err("can't get link info for fd %d: %s", fd, strerror(errno));
797 continue;
798 }
799
800 if (info.type != BPF_LINK_TYPE_NETFILTER)
801 continue;
802
803 if (nf_link_count >= nf_link_len) {
804 static const unsigned int max_link_count = INT_MAX / sizeof(info);
805 struct bpf_link_info *expand;
806
807 if (nf_link_count > max_link_count) {
808 p_err("cannot handle more than %u links\n", max_link_count);
809 break;
810 }
811
812 nf_link_len += 16;
813
814 expand = realloc(nf_link_info, nf_link_len * sizeof(info));
815 if (!expand) {
816 p_err("realloc: %s", strerror(errno));
817 break;
818 }
819
820 nf_link_info = expand;
821 }
822
823 nf_link_info[nf_link_count] = info;
824 nf_link_count++;
825 }
826
827 qsort(nf_link_info, nf_link_count, sizeof(*nf_link_info), netfilter_link_compar);
828
829 for (id = 0; id < nf_link_count; id++) {
830 NET_START_OBJECT;
831 if (json_output)
832 netfilter_dump_json(&nf_link_info[id], json_wtr);
833 else
834 netfilter_dump_plain(&nf_link_info[id]);
835
836 NET_DUMP_UINT("id", " prog_id %u", nf_link_info[id].prog_id);
837 NET_END_OBJECT;
838 }
839
840 free(nf_link_info);
841 }
842
843 static int do_show(int argc, char **argv)
844 {
845 struct bpf_attach_info attach_info = {};
846 int i, sock, ret, filter_idx = -1;
847 struct bpf_netdev_t dev_array;
848 unsigned int nl_pid = 0;
849 char err_buf[256];
850
851 if (argc == 2) {
852 filter_idx = net_parse_dev(&argc, &argv);
853 if (filter_idx < 1)
854 return -1;
855 } else if (argc != 0) {
856 usage();
857 }
858
859 ret = query_flow_dissector(&attach_info);
860 if (ret)
861 return -1;
862
863 sock = netlink_open(&nl_pid);
864 if (sock < 0) {
865 fprintf(stderr, "failed to open netlink sock\n");
866 return -1;
867 }
868
869 dev_array.devices = NULL;
870 dev_array.used_len = 0;
871 dev_array.array_len = 0;
872 dev_array.filter_idx = filter_idx;
873
874 if (json_output)
875 jsonw_start_array(json_wtr);
876 NET_START_OBJECT;
877 NET_START_ARRAY("xdp", "%s:\n");
878 ret = netlink_get_link(sock, nl_pid, dump_link_nlmsg, &dev_array);
879 NET_END_ARRAY("\n");
880
881 if (!ret) {
882 NET_START_ARRAY("tc", "%s:\n");
883 for (i = 0; i < dev_array.used_len; i++) {
884 show_dev_tc_bpf(&dev_array.devices[i]);
885 ret = show_dev_tc_bpf_classic(sock, nl_pid,
886 &dev_array.devices[i]);
887 if (ret)
888 break;
889 }
890 NET_END_ARRAY("\n");
891 }
892
893 NET_START_ARRAY("flow_dissector", "%s:\n");
894 if (attach_info.flow_dissector_id > 0)
895 NET_DUMP_UINT("id", "id %u", attach_info.flow_dissector_id);
896 NET_END_ARRAY("\n");
897
898 NET_START_ARRAY("netfilter", "%s:\n");
899 show_link_netfilter();
900 NET_END_ARRAY("\n");
901
902 NET_END_OBJECT;
903 if (json_output)
904 jsonw_end_array(json_wtr);
905
906 if (ret) {
907 if (json_output)
908 jsonw_null(json_wtr);
909 libbpf_strerror(ret, err_buf, sizeof(err_buf));
910 fprintf(stderr, "Error: %s\n", err_buf);
911 }
912 free(dev_array.devices);
913 close(sock);
914 return ret;
915 }
916
917 static int do_help(int argc, char **argv)
918 {
919 if (json_output) {
920 jsonw_null(json_wtr);
921 return 0;
922 }
923
924 fprintf(stderr,
925 "Usage: %1$s %2$s { show | list } [dev <devname>]\n"
926 " %1$s %2$s attach ATTACH_TYPE PROG dev <devname> [ overwrite ]\n"
927 " %1$s %2$s detach ATTACH_TYPE dev <devname>\n"
928 " %1$s %2$s help\n"
929 "\n"
930 " " HELP_SPEC_PROGRAM "\n"
931 " ATTACH_TYPE := { xdp | xdpgeneric | xdpdrv | xdpoffload }\n"
932 " " HELP_SPEC_OPTIONS " }\n"
933 "\n"
934 "Note: Only xdp, tcx, tc, netkit, flow_dissector and netfilter attachments\n"
935 " are currently supported.\n"
936 " For progs attached to cgroups, use \"bpftool cgroup\"\n"
937 " to dump program attachments. For program types\n"
938 " sk_{filter,skb,msg,reuseport} and lwt/seg6, please\n"
939 " consult iproute2.\n"
940 "",
941 bin_name, argv[-2]);
942
943 return 0;
944 }
945
946 static const struct cmd cmds[] = {
947 { "show", do_show },
948 { "list", do_show },
949 { "attach", do_attach },
950 { "detach", do_detach },
951 { "help", do_help },
952 { 0 }
953 };
954
955 int do_net(int argc, char **argv)
956 {
957 return cmd_select(cmds, argc, argv, do_help);
958 }
959
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.