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
parse_attach_type(const char * str)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
netlink_open(__u32 * nl_pid)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
netlink_recv(int sock,__u32 nl_pid,__u32 seq,__dump_nlmsg_t _fn,dump_nlmsg_t fn,void * cookie)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[4096];
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 ret = 0;
206 done:
207 return ret;
208 }
209
__dump_class_nlmsg(struct nlmsghdr * nlh,dump_nlmsg_t dump_class_nlmsg,void * cookie)210 static int __dump_class_nlmsg(struct nlmsghdr *nlh,
211 dump_nlmsg_t dump_class_nlmsg,
212 void *cookie)
213 {
214 struct nlattr *tb[TCA_MAX + 1], *attr;
215 struct tcmsg *t = NLMSG_DATA(nlh);
216 int len;
217
218 len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*t));
219 attr = (struct nlattr *) ((void *) t + NLMSG_ALIGN(sizeof(*t)));
220 if (libbpf_nla_parse(tb, TCA_MAX, attr, len, NULL) != 0)
221 return -LIBBPF_ERRNO__NLPARSE;
222
223 return dump_class_nlmsg(cookie, t, tb);
224 }
225
netlink_get_class(int sock,unsigned int nl_pid,int ifindex,dump_nlmsg_t dump_class_nlmsg,void * cookie)226 static int netlink_get_class(int sock, unsigned int nl_pid, int ifindex,
227 dump_nlmsg_t dump_class_nlmsg, void *cookie)
228 {
229 struct {
230 struct nlmsghdr nlh;
231 struct tcmsg t;
232 } req = {
233 .nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg)),
234 .nlh.nlmsg_type = RTM_GETTCLASS,
235 .nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
236 .t.tcm_family = AF_UNSPEC,
237 .t.tcm_ifindex = ifindex,
238 };
239 int seq = time(NULL);
240
241 req.nlh.nlmsg_seq = seq;
242 if (send(sock, &req, req.nlh.nlmsg_len, 0) < 0)
243 return -errno;
244
245 return netlink_recv(sock, nl_pid, seq, __dump_class_nlmsg,
246 dump_class_nlmsg, cookie);
247 }
248
__dump_qdisc_nlmsg(struct nlmsghdr * nlh,dump_nlmsg_t dump_qdisc_nlmsg,void * cookie)249 static int __dump_qdisc_nlmsg(struct nlmsghdr *nlh,
250 dump_nlmsg_t dump_qdisc_nlmsg,
251 void *cookie)
252 {
253 struct nlattr *tb[TCA_MAX + 1], *attr;
254 struct tcmsg *t = NLMSG_DATA(nlh);
255 int len;
256
257 len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*t));
258 attr = (struct nlattr *) ((void *) t + NLMSG_ALIGN(sizeof(*t)));
259 if (libbpf_nla_parse(tb, TCA_MAX, attr, len, NULL) != 0)
260 return -LIBBPF_ERRNO__NLPARSE;
261
262 return dump_qdisc_nlmsg(cookie, t, tb);
263 }
264
netlink_get_qdisc(int sock,unsigned int nl_pid,int ifindex,dump_nlmsg_t dump_qdisc_nlmsg,void * cookie)265 static int netlink_get_qdisc(int sock, unsigned int nl_pid, int ifindex,
266 dump_nlmsg_t dump_qdisc_nlmsg, void *cookie)
267 {
268 struct {
269 struct nlmsghdr nlh;
270 struct tcmsg t;
271 } req = {
272 .nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg)),
273 .nlh.nlmsg_type = RTM_GETQDISC,
274 .nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
275 .t.tcm_family = AF_UNSPEC,
276 .t.tcm_ifindex = ifindex,
277 };
278 int seq = time(NULL);
279
280 req.nlh.nlmsg_seq = seq;
281 if (send(sock, &req, req.nlh.nlmsg_len, 0) < 0)
282 return -errno;
283
284 return netlink_recv(sock, nl_pid, seq, __dump_qdisc_nlmsg,
285 dump_qdisc_nlmsg, cookie);
286 }
287
__dump_filter_nlmsg(struct nlmsghdr * nlh,dump_nlmsg_t dump_filter_nlmsg,void * cookie)288 static int __dump_filter_nlmsg(struct nlmsghdr *nlh,
289 dump_nlmsg_t dump_filter_nlmsg,
290 void *cookie)
291 {
292 struct nlattr *tb[TCA_MAX + 1], *attr;
293 struct tcmsg *t = NLMSG_DATA(nlh);
294 int len;
295
296 len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*t));
297 attr = (struct nlattr *) ((void *) t + NLMSG_ALIGN(sizeof(*t)));
298 if (libbpf_nla_parse(tb, TCA_MAX, attr, len, NULL) != 0)
299 return -LIBBPF_ERRNO__NLPARSE;
300
301 return dump_filter_nlmsg(cookie, t, tb);
302 }
303
netlink_get_filter(int sock,unsigned int nl_pid,int ifindex,int handle,dump_nlmsg_t dump_filter_nlmsg,void * cookie)304 static int netlink_get_filter(int sock, unsigned int nl_pid, int ifindex, int handle,
305 dump_nlmsg_t dump_filter_nlmsg, void *cookie)
306 {
307 struct {
308 struct nlmsghdr nlh;
309 struct tcmsg t;
310 } req = {
311 .nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg)),
312 .nlh.nlmsg_type = RTM_GETTFILTER,
313 .nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
314 .t.tcm_family = AF_UNSPEC,
315 .t.tcm_ifindex = ifindex,
316 .t.tcm_parent = handle,
317 };
318 int seq = time(NULL);
319
320 req.nlh.nlmsg_seq = seq;
321 if (send(sock, &req, req.nlh.nlmsg_len, 0) < 0)
322 return -errno;
323
324 return netlink_recv(sock, nl_pid, seq, __dump_filter_nlmsg,
325 dump_filter_nlmsg, cookie);
326 }
327
__dump_link_nlmsg(struct nlmsghdr * nlh,dump_nlmsg_t dump_link_nlmsg,void * cookie)328 static int __dump_link_nlmsg(struct nlmsghdr *nlh,
329 dump_nlmsg_t dump_link_nlmsg, void *cookie)
330 {
331 struct nlattr *tb[IFLA_MAX + 1], *attr;
332 struct ifinfomsg *ifi = NLMSG_DATA(nlh);
333 int len;
334
335 len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*ifi));
336 attr = (struct nlattr *) ((void *) ifi + NLMSG_ALIGN(sizeof(*ifi)));
337 if (libbpf_nla_parse(tb, IFLA_MAX, attr, len, NULL) != 0)
338 return -LIBBPF_ERRNO__NLPARSE;
339
340 return dump_link_nlmsg(cookie, ifi, tb);
341 }
342
netlink_get_link(int sock,unsigned int nl_pid,dump_nlmsg_t dump_link_nlmsg,void * cookie)343 static int netlink_get_link(int sock, unsigned int nl_pid,
344 dump_nlmsg_t dump_link_nlmsg, void *cookie)
345 {
346 struct {
347 struct nlmsghdr nlh;
348 struct ifinfomsg ifm;
349 } req = {
350 .nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg)),
351 .nlh.nlmsg_type = RTM_GETLINK,
352 .nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
353 .ifm.ifi_family = AF_PACKET,
354 };
355 int seq = time(NULL);
356
357 req.nlh.nlmsg_seq = seq;
358 if (send(sock, &req, req.nlh.nlmsg_len, 0) < 0)
359 return -errno;
360
361 return netlink_recv(sock, nl_pid, seq, __dump_link_nlmsg,
362 dump_link_nlmsg, cookie);
363 }
364
dump_link_nlmsg(void * cookie,void * msg,struct nlattr ** tb)365 static int dump_link_nlmsg(void *cookie, void *msg, struct nlattr **tb)
366 {
367 struct bpf_netdev_t *netinfo = cookie;
368 struct ifinfomsg *ifinfo = msg;
369
370 if (netinfo->filter_idx > 0 && netinfo->filter_idx != ifinfo->ifi_index)
371 return 0;
372
373 if (netinfo->used_len == netinfo->array_len) {
374 netinfo->devices = realloc(netinfo->devices,
375 (netinfo->array_len + 16) *
376 sizeof(struct ip_devname_ifindex));
377 if (!netinfo->devices)
378 return -ENOMEM;
379
380 netinfo->array_len += 16;
381 }
382 netinfo->devices[netinfo->used_len].ifindex = ifinfo->ifi_index;
383 snprintf(netinfo->devices[netinfo->used_len].devname,
384 sizeof(netinfo->devices[netinfo->used_len].devname),
385 "%s",
386 tb[IFLA_IFNAME]
387 ? libbpf_nla_getattr_str(tb[IFLA_IFNAME])
388 : "");
389 netinfo->used_len++;
390
391 return do_xdp_dump(ifinfo, tb);
392 }
393
dump_class_qdisc_nlmsg(void * cookie,void * msg,struct nlattr ** tb)394 static int dump_class_qdisc_nlmsg(void *cookie, void *msg, struct nlattr **tb)
395 {
396 struct bpf_tcinfo_t *tcinfo = cookie;
397 struct tcmsg *info = msg;
398
399 if (tcinfo->is_qdisc) {
400 /* skip clsact qdisc */
401 if (tb[TCA_KIND] &&
402 strcmp(libbpf_nla_data(tb[TCA_KIND]), "clsact") == 0)
403 return 0;
404 if (info->tcm_handle == 0)
405 return 0;
406 }
407
408 if (tcinfo->used_len == tcinfo->array_len) {
409 tcinfo->handle_array = realloc(tcinfo->handle_array,
410 (tcinfo->array_len + 16) * sizeof(struct tc_kind_handle));
411 if (!tcinfo->handle_array)
412 return -ENOMEM;
413
414 tcinfo->array_len += 16;
415 }
416 tcinfo->handle_array[tcinfo->used_len].handle = info->tcm_handle;
417 snprintf(tcinfo->handle_array[tcinfo->used_len].kind,
418 sizeof(tcinfo->handle_array[tcinfo->used_len].kind),
419 "%s",
420 tb[TCA_KIND]
421 ? libbpf_nla_getattr_str(tb[TCA_KIND])
422 : "unknown");
423 tcinfo->used_len++;
424
425 return 0;
426 }
427
dump_filter_nlmsg(void * cookie,void * msg,struct nlattr ** tb)428 static int dump_filter_nlmsg(void *cookie, void *msg, struct nlattr **tb)
429 {
430 const struct bpf_filter_t *filter_info = cookie;
431
432 return do_filter_dump((struct tcmsg *)msg, tb, filter_info->kind,
433 filter_info->devname, filter_info->ifindex);
434 }
435
__show_dev_tc_bpf_name(__u32 id,char * name,size_t len)436 static int __show_dev_tc_bpf_name(__u32 id, char *name, size_t len)
437 {
438 struct bpf_prog_info info = {};
439 __u32 ilen = sizeof(info);
440 int fd, ret;
441
442 fd = bpf_prog_get_fd_by_id(id);
443 if (fd < 0)
444 return fd;
445 ret = bpf_obj_get_info_by_fd(fd, &info, &ilen);
446 if (ret < 0)
447 goto out;
448 ret = -ENOENT;
449 if (info.name[0]) {
450 get_prog_full_name(&info, fd, name, len);
451 ret = 0;
452 }
453 out:
454 close(fd);
455 return ret;
456 }
457
__show_dev_tc_bpf(const struct ip_devname_ifindex * dev,const enum bpf_attach_type loc)458 static void __show_dev_tc_bpf(const struct ip_devname_ifindex *dev,
459 const enum bpf_attach_type loc)
460 {
461 __u32 prog_flags[64] = {}, link_flags[64] = {}, i, j;
462 __u32 prog_ids[64] = {}, link_ids[64] = {};
463 LIBBPF_OPTS(bpf_prog_query_opts, optq);
464 char prog_name[MAX_PROG_FULL_NAME];
465 int ret;
466
467 optq.prog_ids = prog_ids;
468 optq.prog_attach_flags = prog_flags;
469 optq.link_ids = link_ids;
470 optq.link_attach_flags = link_flags;
471 optq.count = ARRAY_SIZE(prog_ids);
472
473 ret = bpf_prog_query_opts(dev->ifindex, loc, &optq);
474 if (ret)
475 return;
476 for (i = 0; i < optq.count; i++) {
477 NET_START_OBJECT;
478 NET_DUMP_STR("devname", "%s", dev->devname);
479 NET_DUMP_UINT("ifindex", "(%u)", dev->ifindex);
480 NET_DUMP_STR("kind", " %s", attach_loc_strings[loc]);
481 ret = __show_dev_tc_bpf_name(prog_ids[i], prog_name,
482 sizeof(prog_name));
483 if (!ret)
484 NET_DUMP_STR("name", " %s", prog_name);
485 NET_DUMP_UINT("prog_id", " prog_id %u ", prog_ids[i]);
486 if (prog_flags[i] || json_output) {
487 NET_START_ARRAY("prog_flags", "%s ");
488 for (j = 0; prog_flags[i] && j < 32; j++) {
489 if (!(prog_flags[i] & (1U << j)))
490 continue;
491 NET_DUMP_UINT_ONLY(1U << j);
492 }
493 NET_END_ARRAY("");
494 }
495 if (link_ids[i] || json_output) {
496 NET_DUMP_UINT("link_id", "link_id %u ", link_ids[i]);
497 if (link_flags[i] || json_output) {
498 NET_START_ARRAY("link_flags", "%s ");
499 for (j = 0; link_flags[i] && j < 32; j++) {
500 if (!(link_flags[i] & (1U << j)))
501 continue;
502 NET_DUMP_UINT_ONLY(1U << j);
503 }
504 NET_END_ARRAY("");
505 }
506 }
507 NET_END_OBJECT_FINAL;
508 }
509 }
510
show_dev_tc_bpf(struct ip_devname_ifindex * dev)511 static void show_dev_tc_bpf(struct ip_devname_ifindex *dev)
512 {
513 __show_dev_tc_bpf(dev, BPF_TCX_INGRESS);
514 __show_dev_tc_bpf(dev, BPF_TCX_EGRESS);
515
516 __show_dev_tc_bpf(dev, BPF_NETKIT_PRIMARY);
517 __show_dev_tc_bpf(dev, BPF_NETKIT_PEER);
518 }
519
show_dev_tc_bpf_classic(int sock,unsigned int nl_pid,struct ip_devname_ifindex * dev)520 static int show_dev_tc_bpf_classic(int sock, unsigned int nl_pid,
521 struct ip_devname_ifindex *dev)
522 {
523 struct bpf_filter_t filter_info;
524 struct bpf_tcinfo_t tcinfo;
525 int i, handle, ret = 0;
526
527 tcinfo.handle_array = NULL;
528 tcinfo.used_len = 0;
529 tcinfo.array_len = 0;
530
531 tcinfo.is_qdisc = false;
532 ret = netlink_get_class(sock, nl_pid, dev->ifindex,
533 dump_class_qdisc_nlmsg, &tcinfo);
534 if (ret)
535 goto out;
536
537 tcinfo.is_qdisc = true;
538 ret = netlink_get_qdisc(sock, nl_pid, dev->ifindex,
539 dump_class_qdisc_nlmsg, &tcinfo);
540 if (ret)
541 goto out;
542
543 filter_info.devname = dev->devname;
544 filter_info.ifindex = dev->ifindex;
545 for (i = 0; i < tcinfo.used_len; i++) {
546 filter_info.kind = tcinfo.handle_array[i].kind;
547 ret = netlink_get_filter(sock, nl_pid, dev->ifindex,
548 tcinfo.handle_array[i].handle,
549 dump_filter_nlmsg, &filter_info);
550 if (ret)
551 goto out;
552 }
553
554 /* root, ingress and egress handle */
555 handle = TC_H_ROOT;
556 filter_info.kind = "root";
557 ret = netlink_get_filter(sock, nl_pid, dev->ifindex, handle,
558 dump_filter_nlmsg, &filter_info);
559 if (ret)
560 goto out;
561
562 handle = TC_H_MAKE(TC_H_CLSACT, TC_H_MIN_INGRESS);
563 filter_info.kind = "clsact/ingress";
564 ret = netlink_get_filter(sock, nl_pid, dev->ifindex, handle,
565 dump_filter_nlmsg, &filter_info);
566 if (ret)
567 goto out;
568
569 handle = TC_H_MAKE(TC_H_CLSACT, TC_H_MIN_EGRESS);
570 filter_info.kind = "clsact/egress";
571 ret = netlink_get_filter(sock, nl_pid, dev->ifindex, handle,
572 dump_filter_nlmsg, &filter_info);
573 if (ret)
574 goto out;
575
576 out:
577 free(tcinfo.handle_array);
578 return 0;
579 }
580
query_flow_dissector(struct bpf_attach_info * attach_info)581 static int query_flow_dissector(struct bpf_attach_info *attach_info)
582 {
583 __u32 attach_flags;
584 __u32 prog_ids[1];
585 __u32 prog_cnt;
586 int err;
587 int fd;
588
589 fd = open("/proc/self/ns/net", O_RDONLY);
590 if (fd < 0) {
591 p_err("can't open /proc/self/ns/net: %s",
592 strerror(errno));
593 return -1;
594 }
595 prog_cnt = ARRAY_SIZE(prog_ids);
596 err = bpf_prog_query(fd, BPF_FLOW_DISSECTOR, 0,
597 &attach_flags, prog_ids, &prog_cnt);
598 close(fd);
599 if (err) {
600 if (errno == EINVAL) {
601 /* Older kernel's don't support querying
602 * flow dissector programs.
603 */
604 errno = 0;
605 return 0;
606 }
607 p_err("can't query prog: %s", strerror(errno));
608 return -1;
609 }
610
611 if (prog_cnt == 1)
612 attach_info->flow_dissector_id = prog_ids[0];
613
614 return 0;
615 }
616
net_parse_dev(int * argc,char *** argv)617 static int net_parse_dev(int *argc, char ***argv)
618 {
619 int ifindex;
620
621 if (is_prefix(**argv, "dev")) {
622 NEXT_ARGP();
623
624 ifindex = if_nametoindex(**argv);
625 if (!ifindex)
626 p_err("invalid devname %s", **argv);
627
628 NEXT_ARGP();
629 } else {
630 p_err("expected 'dev', got: '%s'?", **argv);
631 return -1;
632 }
633
634 return ifindex;
635 }
636
do_attach_detach_xdp(int progfd,enum net_attach_type attach_type,int ifindex,bool overwrite)637 static int do_attach_detach_xdp(int progfd, enum net_attach_type attach_type,
638 int ifindex, bool overwrite)
639 {
640 __u32 flags = 0;
641
642 if (!overwrite)
643 flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
644 if (attach_type == NET_ATTACH_TYPE_XDP_GENERIC)
645 flags |= XDP_FLAGS_SKB_MODE;
646 if (attach_type == NET_ATTACH_TYPE_XDP_DRIVER)
647 flags |= XDP_FLAGS_DRV_MODE;
648 if (attach_type == NET_ATTACH_TYPE_XDP_OFFLOAD)
649 flags |= XDP_FLAGS_HW_MODE;
650
651 return bpf_xdp_attach(ifindex, progfd, flags, NULL);
652 }
653
get_tcx_type(enum net_attach_type attach_type)654 static int get_tcx_type(enum net_attach_type attach_type)
655 {
656 switch (attach_type) {
657 case NET_ATTACH_TYPE_TCX_INGRESS:
658 return BPF_TCX_INGRESS;
659 case NET_ATTACH_TYPE_TCX_EGRESS:
660 return BPF_TCX_EGRESS;
661 default:
662 return -1;
663 }
664 }
665
do_attach_tcx(int progfd,enum net_attach_type attach_type,int ifindex)666 static int do_attach_tcx(int progfd, enum net_attach_type attach_type, int ifindex)
667 {
668 int type = get_tcx_type(attach_type);
669
670 return bpf_prog_attach(progfd, ifindex, type, 0);
671 }
672
do_detach_tcx(int targetfd,enum net_attach_type attach_type)673 static int do_detach_tcx(int targetfd, enum net_attach_type attach_type)
674 {
675 int type = get_tcx_type(attach_type);
676
677 return bpf_prog_detach(targetfd, type);
678 }
679
do_attach(int argc,char ** argv)680 static int do_attach(int argc, char **argv)
681 {
682 enum net_attach_type attach_type;
683 int progfd, ifindex, err = 0;
684 bool overwrite = false;
685
686 /* parse attach args */
687 if (!REQ_ARGS(5))
688 return -EINVAL;
689
690 attach_type = parse_attach_type(*argv);
691 if (attach_type == net_attach_type_size) {
692 p_err("invalid net attach/detach type: %s", *argv);
693 return -EINVAL;
694 }
695 NEXT_ARG();
696
697 progfd = prog_parse_fd(&argc, &argv);
698 if (progfd < 0)
699 return -EINVAL;
700
701 ifindex = net_parse_dev(&argc, &argv);
702 if (ifindex < 1) {
703 err = -EINVAL;
704 goto cleanup;
705 }
706
707 if (argc) {
708 if (is_prefix(*argv, "overwrite")) {
709 overwrite = true;
710 } else {
711 p_err("expected 'overwrite', got: '%s'?", *argv);
712 err = -EINVAL;
713 goto cleanup;
714 }
715 }
716
717 switch (attach_type) {
718 /* attach xdp prog */
719 case NET_ATTACH_TYPE_XDP:
720 case NET_ATTACH_TYPE_XDP_GENERIC:
721 case NET_ATTACH_TYPE_XDP_DRIVER:
722 case NET_ATTACH_TYPE_XDP_OFFLOAD:
723 err = do_attach_detach_xdp(progfd, attach_type, ifindex, overwrite);
724 break;
725 /* attach tcx prog */
726 case NET_ATTACH_TYPE_TCX_INGRESS:
727 case NET_ATTACH_TYPE_TCX_EGRESS:
728 err = do_attach_tcx(progfd, attach_type, ifindex);
729 break;
730 default:
731 break;
732 }
733
734 if (err) {
735 p_err("interface %s attach failed: %s",
736 attach_type_strings[attach_type], strerror(-err));
737 goto cleanup;
738 }
739
740 if (json_output)
741 jsonw_null(json_wtr);
742 cleanup:
743 close(progfd);
744 return err;
745 }
746
do_detach(int argc,char ** argv)747 static int do_detach(int argc, char **argv)
748 {
749 enum net_attach_type attach_type;
750 int progfd, ifindex, err = 0;
751
752 /* parse detach args */
753 if (!REQ_ARGS(3))
754 return -EINVAL;
755
756 attach_type = parse_attach_type(*argv);
757 if (attach_type == net_attach_type_size) {
758 p_err("invalid net attach/detach type: %s", *argv);
759 return -EINVAL;
760 }
761 NEXT_ARG();
762
763 ifindex = net_parse_dev(&argc, &argv);
764 if (ifindex < 1)
765 return -EINVAL;
766
767 switch (attach_type) {
768 /* detach xdp prog */
769 case NET_ATTACH_TYPE_XDP:
770 case NET_ATTACH_TYPE_XDP_GENERIC:
771 case NET_ATTACH_TYPE_XDP_DRIVER:
772 case NET_ATTACH_TYPE_XDP_OFFLOAD:
773 progfd = -1;
774 err = do_attach_detach_xdp(progfd, attach_type, ifindex, NULL);
775 break;
776 /* detach tcx prog */
777 case NET_ATTACH_TYPE_TCX_INGRESS:
778 case NET_ATTACH_TYPE_TCX_EGRESS:
779 err = do_detach_tcx(ifindex, attach_type);
780 break;
781 default:
782 break;
783 }
784
785 if (err < 0) {
786 p_err("interface %s detach failed: %s",
787 attach_type_strings[attach_type], strerror(-err));
788 return err;
789 }
790
791 if (json_output)
792 jsonw_null(json_wtr);
793
794 return 0;
795 }
796
netfilter_link_compar(const void * a,const void * b)797 static int netfilter_link_compar(const void *a, const void *b)
798 {
799 const struct bpf_link_info *nfa = a;
800 const struct bpf_link_info *nfb = b;
801 int delta;
802
803 delta = nfa->netfilter.pf - nfb->netfilter.pf;
804 if (delta)
805 return delta;
806
807 delta = nfa->netfilter.hooknum - nfb->netfilter.hooknum;
808 if (delta)
809 return delta;
810
811 if (nfa->netfilter.priority < nfb->netfilter.priority)
812 return -1;
813 if (nfa->netfilter.priority > nfb->netfilter.priority)
814 return 1;
815
816 return nfa->netfilter.flags - nfb->netfilter.flags;
817 }
818
show_link_netfilter(void)819 static void show_link_netfilter(void)
820 {
821 unsigned int nf_link_len = 0, nf_link_count = 0;
822 struct bpf_link_info *nf_link_info = NULL;
823 __u32 id = 0;
824
825 while (true) {
826 struct bpf_link_info info;
827 int fd, err;
828 __u32 len;
829
830 err = bpf_link_get_next_id(id, &id);
831 if (err) {
832 if (errno == ENOENT)
833 break;
834 p_err("can't get next link: %s (id %d)", strerror(errno), id);
835 break;
836 }
837
838 fd = bpf_link_get_fd_by_id(id);
839 if (fd < 0) {
840 p_err("can't get link by id (%u): %s", id, strerror(errno));
841 continue;
842 }
843
844 memset(&info, 0, sizeof(info));
845 len = sizeof(info);
846
847 err = bpf_link_get_info_by_fd(fd, &info, &len);
848
849 close(fd);
850
851 if (err) {
852 p_err("can't get link info for fd %d: %s", fd, strerror(errno));
853 continue;
854 }
855
856 if (info.type != BPF_LINK_TYPE_NETFILTER)
857 continue;
858
859 if (nf_link_count >= nf_link_len) {
860 static const unsigned int max_link_count = INT_MAX / sizeof(info);
861 struct bpf_link_info *expand;
862
863 if (nf_link_count > max_link_count) {
864 p_err("cannot handle more than %u links\n", max_link_count);
865 break;
866 }
867
868 nf_link_len += 16;
869
870 expand = realloc(nf_link_info, nf_link_len * sizeof(info));
871 if (!expand) {
872 p_err("realloc: %s", strerror(errno));
873 break;
874 }
875
876 nf_link_info = expand;
877 }
878
879 nf_link_info[nf_link_count] = info;
880 nf_link_count++;
881 }
882
883 if (!nf_link_info)
884 return;
885
886 qsort(nf_link_info, nf_link_count, sizeof(*nf_link_info), netfilter_link_compar);
887
888 for (id = 0; id < nf_link_count; id++) {
889 NET_START_OBJECT;
890 if (json_output)
891 netfilter_dump_json(&nf_link_info[id], json_wtr);
892 else
893 netfilter_dump_plain(&nf_link_info[id]);
894
895 NET_DUMP_UINT("id", " prog_id %u", nf_link_info[id].prog_id);
896 NET_END_OBJECT;
897 }
898
899 free(nf_link_info);
900 }
901
do_show(int argc,char ** argv)902 static int do_show(int argc, char **argv)
903 {
904 struct bpf_attach_info attach_info = {};
905 int i, sock, ret, filter_idx = -1;
906 struct bpf_netdev_t dev_array;
907 unsigned int nl_pid = 0;
908 char err_buf[256];
909
910 if (argc == 2) {
911 filter_idx = net_parse_dev(&argc, &argv);
912 if (filter_idx < 1)
913 return -1;
914 } else if (argc != 0) {
915 usage();
916 }
917
918 ret = query_flow_dissector(&attach_info);
919 if (ret)
920 return -1;
921
922 sock = netlink_open(&nl_pid);
923 if (sock < 0) {
924 fprintf(stderr, "failed to open netlink sock\n");
925 return -1;
926 }
927
928 dev_array.devices = NULL;
929 dev_array.used_len = 0;
930 dev_array.array_len = 0;
931 dev_array.filter_idx = filter_idx;
932
933 if (json_output)
934 jsonw_start_array(json_wtr);
935 NET_START_OBJECT;
936 NET_START_ARRAY("xdp", "%s:\n");
937 ret = netlink_get_link(sock, nl_pid, dump_link_nlmsg, &dev_array);
938 NET_END_ARRAY("\n");
939
940 if (!ret) {
941 NET_START_ARRAY("tc", "%s:\n");
942 for (i = 0; i < dev_array.used_len; i++) {
943 show_dev_tc_bpf(&dev_array.devices[i]);
944 ret = show_dev_tc_bpf_classic(sock, nl_pid,
945 &dev_array.devices[i]);
946 if (ret)
947 break;
948 }
949 NET_END_ARRAY("\n");
950 }
951
952 NET_START_ARRAY("flow_dissector", "%s:\n");
953 if (attach_info.flow_dissector_id > 0)
954 NET_DUMP_UINT("id", "id %u", attach_info.flow_dissector_id);
955 NET_END_ARRAY("\n");
956
957 NET_START_ARRAY("netfilter", "%s:\n");
958 show_link_netfilter();
959 NET_END_ARRAY("\n");
960
961 NET_END_OBJECT;
962 if (json_output)
963 jsonw_end_array(json_wtr);
964
965 if (ret) {
966 if (json_output)
967 jsonw_null(json_wtr);
968 libbpf_strerror(ret, err_buf, sizeof(err_buf));
969 fprintf(stderr, "Error: %s\n", err_buf);
970 }
971 free(dev_array.devices);
972 close(sock);
973 return ret;
974 }
975
do_help(int argc,char ** argv)976 static int do_help(int argc, char **argv)
977 {
978 if (json_output) {
979 jsonw_null(json_wtr);
980 return 0;
981 }
982
983 fprintf(stderr,
984 "Usage: %1$s %2$s { show | list } [dev <devname>]\n"
985 " %1$s %2$s attach ATTACH_TYPE PROG dev <devname> [ overwrite ]\n"
986 " %1$s %2$s detach ATTACH_TYPE dev <devname>\n"
987 " %1$s %2$s help\n"
988 "\n"
989 " " HELP_SPEC_PROGRAM "\n"
990 " ATTACH_TYPE := { xdp | xdpgeneric | xdpdrv | xdpoffload | tcx_ingress\n"
991 " | tcx_egress }\n"
992 " " HELP_SPEC_OPTIONS " }\n"
993 "\n"
994 "Note: Only xdp, tcx, tc, netkit, flow_dissector and netfilter attachments\n"
995 " are currently supported.\n"
996 " For progs attached to cgroups, use \"bpftool cgroup\"\n"
997 " to dump program attachments. For program types\n"
998 " sk_{filter,skb,msg,reuseport} and lwt/seg6, please\n"
999 " consult iproute2.\n"
1000 "",
1001 bin_name, argv[-2]);
1002
1003 return 0;
1004 }
1005
1006 static const struct cmd cmds[] = {
1007 { "show", do_show },
1008 { "list", do_show },
1009 { "attach", do_attach },
1010 { "detach", do_detach },
1011 { "help", do_help },
1012 { 0 }
1013 };
1014
do_net(int argc,char ** argv)1015 int do_net(int argc, char **argv)
1016 {
1017 return cmd_select(cmds, argc, argv, do_help);
1018 }
1019