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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 <unistd.h>
10#include <bpf/bpf.h>
11#include <bpf/libbpf.h>
12#include <net/if.h>
13#include <linux/if.h>
14#include <linux/rtnetlink.h>
15#include <linux/tc_act/tc_bpf.h>
16#include <sys/socket.h>
17#include <sys/stat.h>
18#include <sys/types.h>
19
20#include "bpf/nlattr.h"
21#include "bpf/libbpf_internal.h"
22#include "main.h"
23#include "netlink_dumper.h"
24
25struct ip_devname_ifindex {
26 char devname[64];
27 int ifindex;
28};
29
30struct bpf_netdev_t {
31 struct ip_devname_ifindex *devices;
32 int used_len;
33 int array_len;
34 int filter_idx;
35};
36
37struct tc_kind_handle {
38 char kind[64];
39 int handle;
40};
41
42struct bpf_tcinfo_t {
43 struct tc_kind_handle *handle_array;
44 int used_len;
45 int array_len;
46 bool is_qdisc;
47};
48
49struct bpf_filter_t {
50 const char *kind;
51 const char *devname;
52 int ifindex;
53};
54
55struct bpf_attach_info {
56 __u32 flow_dissector_id;
57};
58
59enum net_attach_type {
60 NET_ATTACH_TYPE_XDP,
61 NET_ATTACH_TYPE_XDP_GENERIC,
62 NET_ATTACH_TYPE_XDP_DRIVER,
63 NET_ATTACH_TYPE_XDP_OFFLOAD,
64};
65
66static const char * const attach_type_strings[] = {
67 [NET_ATTACH_TYPE_XDP] = "xdp",
68 [NET_ATTACH_TYPE_XDP_GENERIC] = "xdpgeneric",
69 [NET_ATTACH_TYPE_XDP_DRIVER] = "xdpdrv",
70 [NET_ATTACH_TYPE_XDP_OFFLOAD] = "xdpoffload",
71};
72
73const size_t net_attach_type_size = ARRAY_SIZE(attach_type_strings);
74
75static enum net_attach_type parse_attach_type(const char *str)
76{
77 enum net_attach_type type;
78
79 for (type = 0; type < net_attach_type_size; type++) {
80 if (attach_type_strings[type] &&
81 is_prefix(str, attach_type_strings[type]))
82 return type;
83 }
84
85 return net_attach_type_size;
86}
87
88static int dump_link_nlmsg(void *cookie, void *msg, struct nlattr **tb)
89{
90 struct bpf_netdev_t *netinfo = cookie;
91 struct ifinfomsg *ifinfo = msg;
92
93 if (netinfo->filter_idx > 0 && netinfo->filter_idx != ifinfo->ifi_index)
94 return 0;
95
96 if (netinfo->used_len == netinfo->array_len) {
97 netinfo->devices = realloc(netinfo->devices,
98 (netinfo->array_len + 16) *
99 sizeof(struct ip_devname_ifindex));
100 if (!netinfo->devices)
101 return -ENOMEM;
102
103 netinfo->array_len += 16;
104 }
105 netinfo->devices[netinfo->used_len].ifindex = ifinfo->ifi_index;
106 snprintf(netinfo->devices[netinfo->used_len].devname,
107 sizeof(netinfo->devices[netinfo->used_len].devname),
108 "%s",
109 tb[IFLA_IFNAME]
110 ? libbpf_nla_getattr_str(tb[IFLA_IFNAME])
111 : "");
112 netinfo->used_len++;
113
114 return do_xdp_dump(ifinfo, tb);
115}
116
117static int dump_class_qdisc_nlmsg(void *cookie, void *msg, struct nlattr **tb)
118{
119 struct bpf_tcinfo_t *tcinfo = cookie;
120 struct tcmsg *info = msg;
121
122 if (tcinfo->is_qdisc) {
123 /* skip clsact qdisc */
124 if (tb[TCA_KIND] &&
125 strcmp(libbpf_nla_data(tb[TCA_KIND]), "clsact") == 0)
126 return 0;
127 if (info->tcm_handle == 0)
128 return 0;
129 }
130
131 if (tcinfo->used_len == tcinfo->array_len) {
132 tcinfo->handle_array = realloc(tcinfo->handle_array,
133 (tcinfo->array_len + 16) * sizeof(struct tc_kind_handle));
134 if (!tcinfo->handle_array)
135 return -ENOMEM;
136
137 tcinfo->array_len += 16;
138 }
139 tcinfo->handle_array[tcinfo->used_len].handle = info->tcm_handle;
140 snprintf(tcinfo->handle_array[tcinfo->used_len].kind,
141 sizeof(tcinfo->handle_array[tcinfo->used_len].kind),
142 "%s",
143 tb[TCA_KIND]
144 ? libbpf_nla_getattr_str(tb[TCA_KIND])
145 : "unknown");
146 tcinfo->used_len++;
147
148 return 0;
149}
150
151static int dump_filter_nlmsg(void *cookie, void *msg, struct nlattr **tb)
152{
153 const struct bpf_filter_t *filter_info = cookie;
154
155 return do_filter_dump((struct tcmsg *)msg, tb, filter_info->kind,
156 filter_info->devname, filter_info->ifindex);
157}
158
159static int show_dev_tc_bpf(int sock, unsigned int nl_pid,
160 struct ip_devname_ifindex *dev)
161{
162 struct bpf_filter_t filter_info;
163 struct bpf_tcinfo_t tcinfo;
164 int i, handle, ret = 0;
165
166 tcinfo.handle_array = NULL;
167 tcinfo.used_len = 0;
168 tcinfo.array_len = 0;
169
170 tcinfo.is_qdisc = false;
171 ret = libbpf_nl_get_class(sock, nl_pid, dev->ifindex,
172 dump_class_qdisc_nlmsg, &tcinfo);
173 if (ret)
174 goto out;
175
176 tcinfo.is_qdisc = true;
177 ret = libbpf_nl_get_qdisc(sock, nl_pid, dev->ifindex,
178 dump_class_qdisc_nlmsg, &tcinfo);
179 if (ret)
180 goto out;
181
182 filter_info.devname = dev->devname;
183 filter_info.ifindex = dev->ifindex;
184 for (i = 0; i < tcinfo.used_len; i++) {
185 filter_info.kind = tcinfo.handle_array[i].kind;
186 ret = libbpf_nl_get_filter(sock, nl_pid, dev->ifindex,
187 tcinfo.handle_array[i].handle,
188 dump_filter_nlmsg, &filter_info);
189 if (ret)
190 goto out;
191 }
192
193 /* root, ingress and egress handle */
194 handle = TC_H_ROOT;
195 filter_info.kind = "root";
196 ret = libbpf_nl_get_filter(sock, nl_pid, dev->ifindex, handle,
197 dump_filter_nlmsg, &filter_info);
198 if (ret)
199 goto out;
200
201 handle = TC_H_MAKE(TC_H_CLSACT, TC_H_MIN_INGRESS);
202 filter_info.kind = "clsact/ingress";
203 ret = libbpf_nl_get_filter(sock, nl_pid, dev->ifindex, handle,
204 dump_filter_nlmsg, &filter_info);
205 if (ret)
206 goto out;
207
208 handle = TC_H_MAKE(TC_H_CLSACT, TC_H_MIN_EGRESS);
209 filter_info.kind = "clsact/egress";
210 ret = libbpf_nl_get_filter(sock, nl_pid, dev->ifindex, handle,
211 dump_filter_nlmsg, &filter_info);
212 if (ret)
213 goto out;
214
215out:
216 free(tcinfo.handle_array);
217 return 0;
218}
219
220static int query_flow_dissector(struct bpf_attach_info *attach_info)
221{
222 __u32 attach_flags;
223 __u32 prog_ids[1];
224 __u32 prog_cnt;
225 int err;
226 int fd;
227
228 fd = open("/proc/self/ns/net", O_RDONLY);
229 if (fd < 0) {
230 p_err("can't open /proc/self/ns/net: %s",
231 strerror(errno));
232 return -1;
233 }
234 prog_cnt = ARRAY_SIZE(prog_ids);
235 err = bpf_prog_query(fd, BPF_FLOW_DISSECTOR, 0,
236 &attach_flags, prog_ids, &prog_cnt);
237 close(fd);
238 if (err) {
239 if (errno == EINVAL) {
240 /* Older kernel's don't support querying
241 * flow dissector programs.
242 */
243 errno = 0;
244 return 0;
245 }
246 p_err("can't query prog: %s", strerror(errno));
247 return -1;
248 }
249
250 if (prog_cnt == 1)
251 attach_info->flow_dissector_id = prog_ids[0];
252
253 return 0;
254}
255
256static int net_parse_dev(int *argc, char ***argv)
257{
258 int ifindex;
259
260 if (is_prefix(**argv, "dev")) {
261 NEXT_ARGP();
262
263 ifindex = if_nametoindex(**argv);
264 if (!ifindex)
265 p_err("invalid devname %s", **argv);
266
267 NEXT_ARGP();
268 } else {
269 p_err("expected 'dev', got: '%s'?", **argv);
270 return -1;
271 }
272
273 return ifindex;
274}
275
276static int do_attach_detach_xdp(int progfd, enum net_attach_type attach_type,
277 int ifindex, bool overwrite)
278{
279 __u32 flags = 0;
280
281 if (!overwrite)
282 flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
283 if (attach_type == NET_ATTACH_TYPE_XDP_GENERIC)
284 flags |= XDP_FLAGS_SKB_MODE;
285 if (attach_type == NET_ATTACH_TYPE_XDP_DRIVER)
286 flags |= XDP_FLAGS_DRV_MODE;
287 if (attach_type == NET_ATTACH_TYPE_XDP_OFFLOAD)
288 flags |= XDP_FLAGS_HW_MODE;
289
290 return bpf_set_link_xdp_fd(ifindex, progfd, flags);
291}
292
293static int do_attach(int argc, char **argv)
294{
295 enum net_attach_type attach_type;
296 int progfd, ifindex, err = 0;
297 bool overwrite = false;
298
299 /* parse attach args */
300 if (!REQ_ARGS(5))
301 return -EINVAL;
302
303 attach_type = parse_attach_type(*argv);
304 if (attach_type == net_attach_type_size) {
305 p_err("invalid net attach/detach type: %s", *argv);
306 return -EINVAL;
307 }
308 NEXT_ARG();
309
310 progfd = prog_parse_fd(&argc, &argv);
311 if (progfd < 0)
312 return -EINVAL;
313
314 ifindex = net_parse_dev(&argc, &argv);
315 if (ifindex < 1) {
316 close(progfd);
317 return -EINVAL;
318 }
319
320 if (argc) {
321 if (is_prefix(*argv, "overwrite")) {
322 overwrite = true;
323 } else {
324 p_err("expected 'overwrite', got: '%s'?", *argv);
325 close(progfd);
326 return -EINVAL;
327 }
328 }
329
330 /* attach xdp prog */
331 if (is_prefix("xdp", attach_type_strings[attach_type]))
332 err = do_attach_detach_xdp(progfd, attach_type, ifindex,
333 overwrite);
334
335 if (err < 0) {
336 p_err("interface %s attach failed: %s",
337 attach_type_strings[attach_type], strerror(-err));
338 return err;
339 }
340
341 if (json_output)
342 jsonw_null(json_wtr);
343
344 return 0;
345}
346
347static int do_detach(int argc, char **argv)
348{
349 enum net_attach_type attach_type;
350 int progfd, ifindex, err = 0;
351
352 /* parse detach args */
353 if (!REQ_ARGS(3))
354 return -EINVAL;
355
356 attach_type = parse_attach_type(*argv);
357 if (attach_type == net_attach_type_size) {
358 p_err("invalid net attach/detach type: %s", *argv);
359 return -EINVAL;
360 }
361 NEXT_ARG();
362
363 ifindex = net_parse_dev(&argc, &argv);
364 if (ifindex < 1)
365 return -EINVAL;
366
367 /* detach xdp prog */
368 progfd = -1;
369 if (is_prefix("xdp", attach_type_strings[attach_type]))
370 err = do_attach_detach_xdp(progfd, attach_type, ifindex, NULL);
371
372 if (err < 0) {
373 p_err("interface %s detach failed: %s",
374 attach_type_strings[attach_type], strerror(-err));
375 return err;
376 }
377
378 if (json_output)
379 jsonw_null(json_wtr);
380
381 return 0;
382}
383
384static int do_show(int argc, char **argv)
385{
386 struct bpf_attach_info attach_info = {};
387 int i, sock, ret, filter_idx = -1;
388 struct bpf_netdev_t dev_array;
389 unsigned int nl_pid;
390 char err_buf[256];
391
392 if (argc == 2) {
393 filter_idx = net_parse_dev(&argc, &argv);
394 if (filter_idx < 1)
395 return -1;
396 } else if (argc != 0) {
397 usage();
398 }
399
400 ret = query_flow_dissector(&attach_info);
401 if (ret)
402 return -1;
403
404 sock = libbpf_netlink_open(&nl_pid);
405 if (sock < 0) {
406 fprintf(stderr, "failed to open netlink sock\n");
407 return -1;
408 }
409
410 dev_array.devices = NULL;
411 dev_array.used_len = 0;
412 dev_array.array_len = 0;
413 dev_array.filter_idx = filter_idx;
414
415 if (json_output)
416 jsonw_start_array(json_wtr);
417 NET_START_OBJECT;
418 NET_START_ARRAY("xdp", "%s:\n");
419 ret = libbpf_nl_get_link(sock, nl_pid, dump_link_nlmsg, &dev_array);
420 NET_END_ARRAY("\n");
421
422 if (!ret) {
423 NET_START_ARRAY("tc", "%s:\n");
424 for (i = 0; i < dev_array.used_len; i++) {
425 ret = show_dev_tc_bpf(sock, nl_pid,
426 &dev_array.devices[i]);
427 if (ret)
428 break;
429 }
430 NET_END_ARRAY("\n");
431 }
432
433 NET_START_ARRAY("flow_dissector", "%s:\n");
434 if (attach_info.flow_dissector_id > 0)
435 NET_DUMP_UINT("id", "id %u", attach_info.flow_dissector_id);
436 NET_END_ARRAY("\n");
437
438 NET_END_OBJECT;
439 if (json_output)
440 jsonw_end_array(json_wtr);
441
442 if (ret) {
443 if (json_output)
444 jsonw_null(json_wtr);
445 libbpf_strerror(ret, err_buf, sizeof(err_buf));
446 fprintf(stderr, "Error: %s\n", err_buf);
447 }
448 free(dev_array.devices);
449 close(sock);
450 return ret;
451}
452
453static int do_help(int argc, char **argv)
454{
455 if (json_output) {
456 jsonw_null(json_wtr);
457 return 0;
458 }
459
460 fprintf(stderr,
461 "Usage: %1$s %2$s { show | list } [dev <devname>]\n"
462 " %1$s %2$s attach ATTACH_TYPE PROG dev <devname> [ overwrite ]\n"
463 " %1$s %2$s detach ATTACH_TYPE dev <devname>\n"
464 " %1$s %2$s help\n"
465 "\n"
466 " " HELP_SPEC_PROGRAM "\n"
467 " ATTACH_TYPE := { xdp | xdpgeneric | xdpdrv | xdpoffload }\n"
468 "\n"
469 "Note: Only xdp and tc attachments are supported now.\n"
470 " For progs attached to cgroups, use \"bpftool cgroup\"\n"
471 " to dump program attachments. For program types\n"
472 " sk_{filter,skb,msg,reuseport} and lwt/seg6, please\n"
473 " consult iproute2.\n"
474 "",
475 bin_name, argv[-2]);
476
477 return 0;
478}
479
480static const struct cmd cmds[] = {
481 { "show", do_show },
482 { "list", do_show },
483 { "attach", do_attach },
484 { "detach", do_detach },
485 { "help", do_help },
486 { 0 }
487};
488
489int do_net(int argc, char **argv)
490{
491 return cmd_select(cmds, argc, argv, do_help);
492}