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