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