xref: /openbmc/linux/tools/bpf/bpftool/link.c (revision 9470114d)
1 // SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
2 /* Copyright (C) 2020 Facebook */
3 
4 #include <errno.h>
5 #include <linux/err.h>
6 #include <linux/netfilter.h>
7 #include <linux/netfilter_arp.h>
8 #include <linux/perf_event.h>
9 #include <net/if.h>
10 #include <stdio.h>
11 #include <unistd.h>
12 
13 #include <bpf/bpf.h>
14 #include <bpf/hashmap.h>
15 
16 #include "json_writer.h"
17 #include "main.h"
18 #include "xlated_dumper.h"
19 
20 #define PERF_HW_CACHE_LEN 128
21 
22 static struct hashmap *link_table;
23 static struct dump_data dd;
24 
25 static const char *perf_type_name[PERF_TYPE_MAX] = {
26 	[PERF_TYPE_HARDWARE]			= "hardware",
27 	[PERF_TYPE_SOFTWARE]			= "software",
28 	[PERF_TYPE_TRACEPOINT]			= "tracepoint",
29 	[PERF_TYPE_HW_CACHE]			= "hw-cache",
30 	[PERF_TYPE_RAW]				= "raw",
31 	[PERF_TYPE_BREAKPOINT]			= "breakpoint",
32 };
33 
34 const char *event_symbols_hw[PERF_COUNT_HW_MAX] = {
35 	[PERF_COUNT_HW_CPU_CYCLES]		= "cpu-cycles",
36 	[PERF_COUNT_HW_INSTRUCTIONS]		= "instructions",
37 	[PERF_COUNT_HW_CACHE_REFERENCES]	= "cache-references",
38 	[PERF_COUNT_HW_CACHE_MISSES]		= "cache-misses",
39 	[PERF_COUNT_HW_BRANCH_INSTRUCTIONS]	= "branch-instructions",
40 	[PERF_COUNT_HW_BRANCH_MISSES]		= "branch-misses",
41 	[PERF_COUNT_HW_BUS_CYCLES]		= "bus-cycles",
42 	[PERF_COUNT_HW_STALLED_CYCLES_FRONTEND]	= "stalled-cycles-frontend",
43 	[PERF_COUNT_HW_STALLED_CYCLES_BACKEND]	= "stalled-cycles-backend",
44 	[PERF_COUNT_HW_REF_CPU_CYCLES]		= "ref-cycles",
45 };
46 
47 const char *event_symbols_sw[PERF_COUNT_SW_MAX] = {
48 	[PERF_COUNT_SW_CPU_CLOCK]		= "cpu-clock",
49 	[PERF_COUNT_SW_TASK_CLOCK]		= "task-clock",
50 	[PERF_COUNT_SW_PAGE_FAULTS]		= "page-faults",
51 	[PERF_COUNT_SW_CONTEXT_SWITCHES]	= "context-switches",
52 	[PERF_COUNT_SW_CPU_MIGRATIONS]		= "cpu-migrations",
53 	[PERF_COUNT_SW_PAGE_FAULTS_MIN]		= "minor-faults",
54 	[PERF_COUNT_SW_PAGE_FAULTS_MAJ]		= "major-faults",
55 	[PERF_COUNT_SW_ALIGNMENT_FAULTS]	= "alignment-faults",
56 	[PERF_COUNT_SW_EMULATION_FAULTS]	= "emulation-faults",
57 	[PERF_COUNT_SW_DUMMY]			= "dummy",
58 	[PERF_COUNT_SW_BPF_OUTPUT]		= "bpf-output",
59 	[PERF_COUNT_SW_CGROUP_SWITCHES]		= "cgroup-switches",
60 };
61 
62 const char *evsel__hw_cache[PERF_COUNT_HW_CACHE_MAX] = {
63 	[PERF_COUNT_HW_CACHE_L1D]		= "L1-dcache",
64 	[PERF_COUNT_HW_CACHE_L1I]		= "L1-icache",
65 	[PERF_COUNT_HW_CACHE_LL]		= "LLC",
66 	[PERF_COUNT_HW_CACHE_DTLB]		= "dTLB",
67 	[PERF_COUNT_HW_CACHE_ITLB]		= "iTLB",
68 	[PERF_COUNT_HW_CACHE_BPU]		= "branch",
69 	[PERF_COUNT_HW_CACHE_NODE]		= "node",
70 };
71 
72 const char *evsel__hw_cache_op[PERF_COUNT_HW_CACHE_OP_MAX] = {
73 	[PERF_COUNT_HW_CACHE_OP_READ]		= "load",
74 	[PERF_COUNT_HW_CACHE_OP_WRITE]		= "store",
75 	[PERF_COUNT_HW_CACHE_OP_PREFETCH]	= "prefetch",
76 };
77 
78 const char *evsel__hw_cache_result[PERF_COUNT_HW_CACHE_RESULT_MAX] = {
79 	[PERF_COUNT_HW_CACHE_RESULT_ACCESS]	= "refs",
80 	[PERF_COUNT_HW_CACHE_RESULT_MISS]	= "misses",
81 };
82 
83 #define perf_event_name(array, id) ({			\
84 	const char *event_str = NULL;			\
85 							\
86 	if ((id) < ARRAY_SIZE(array))			\
87 		event_str = array[id];			\
88 	event_str;					\
89 })
90 
91 static int link_parse_fd(int *argc, char ***argv)
92 {
93 	int fd;
94 
95 	if (is_prefix(**argv, "id")) {
96 		unsigned int id;
97 		char *endptr;
98 
99 		NEXT_ARGP();
100 
101 		id = strtoul(**argv, &endptr, 0);
102 		if (*endptr) {
103 			p_err("can't parse %s as ID", **argv);
104 			return -1;
105 		}
106 		NEXT_ARGP();
107 
108 		fd = bpf_link_get_fd_by_id(id);
109 		if (fd < 0)
110 			p_err("failed to get link with ID %d: %s", id, strerror(errno));
111 		return fd;
112 	} else if (is_prefix(**argv, "pinned")) {
113 		char *path;
114 
115 		NEXT_ARGP();
116 
117 		path = **argv;
118 		NEXT_ARGP();
119 
120 		return open_obj_pinned_any(path, BPF_OBJ_LINK);
121 	}
122 
123 	p_err("expected 'id' or 'pinned', got: '%s'?", **argv);
124 	return -1;
125 }
126 
127 static void
128 show_link_header_json(struct bpf_link_info *info, json_writer_t *wtr)
129 {
130 	const char *link_type_str;
131 
132 	jsonw_uint_field(wtr, "id", info->id);
133 	link_type_str = libbpf_bpf_link_type_str(info->type);
134 	if (link_type_str)
135 		jsonw_string_field(wtr, "type", link_type_str);
136 	else
137 		jsonw_uint_field(wtr, "type", info->type);
138 
139 	jsonw_uint_field(json_wtr, "prog_id", info->prog_id);
140 }
141 
142 static void show_link_attach_type_json(__u32 attach_type, json_writer_t *wtr)
143 {
144 	const char *attach_type_str;
145 
146 	attach_type_str = libbpf_bpf_attach_type_str(attach_type);
147 	if (attach_type_str)
148 		jsonw_string_field(wtr, "attach_type", attach_type_str);
149 	else
150 		jsonw_uint_field(wtr, "attach_type", attach_type);
151 }
152 
153 static void show_link_ifindex_json(__u32 ifindex, json_writer_t *wtr)
154 {
155 	char devname[IF_NAMESIZE] = "(unknown)";
156 
157 	if (ifindex)
158 		if_indextoname(ifindex, devname);
159 	else
160 		snprintf(devname, sizeof(devname), "(detached)");
161 	jsonw_string_field(wtr, "devname", devname);
162 	jsonw_uint_field(wtr, "ifindex", ifindex);
163 }
164 
165 static bool is_iter_map_target(const char *target_name)
166 {
167 	return strcmp(target_name, "bpf_map_elem") == 0 ||
168 	       strcmp(target_name, "bpf_sk_storage_map") == 0;
169 }
170 
171 static bool is_iter_cgroup_target(const char *target_name)
172 {
173 	return strcmp(target_name, "cgroup") == 0;
174 }
175 
176 static const char *cgroup_order_string(__u32 order)
177 {
178 	switch (order) {
179 	case BPF_CGROUP_ITER_ORDER_UNSPEC:
180 		return "order_unspec";
181 	case BPF_CGROUP_ITER_SELF_ONLY:
182 		return "self_only";
183 	case BPF_CGROUP_ITER_DESCENDANTS_PRE:
184 		return "descendants_pre";
185 	case BPF_CGROUP_ITER_DESCENDANTS_POST:
186 		return "descendants_post";
187 	case BPF_CGROUP_ITER_ANCESTORS_UP:
188 		return "ancestors_up";
189 	default: /* won't happen */
190 		return "unknown";
191 	}
192 }
193 
194 static bool is_iter_task_target(const char *target_name)
195 {
196 	return strcmp(target_name, "task") == 0 ||
197 		strcmp(target_name, "task_file") == 0 ||
198 		strcmp(target_name, "task_vma") == 0;
199 }
200 
201 static void show_iter_json(struct bpf_link_info *info, json_writer_t *wtr)
202 {
203 	const char *target_name = u64_to_ptr(info->iter.target_name);
204 
205 	jsonw_string_field(wtr, "target_name", target_name);
206 
207 	if (is_iter_map_target(target_name))
208 		jsonw_uint_field(wtr, "map_id", info->iter.map.map_id);
209 	else if (is_iter_task_target(target_name)) {
210 		if (info->iter.task.tid)
211 			jsonw_uint_field(wtr, "tid", info->iter.task.tid);
212 		else if (info->iter.task.pid)
213 			jsonw_uint_field(wtr, "pid", info->iter.task.pid);
214 	}
215 
216 	if (is_iter_cgroup_target(target_name)) {
217 		jsonw_lluint_field(wtr, "cgroup_id", info->iter.cgroup.cgroup_id);
218 		jsonw_string_field(wtr, "order",
219 				   cgroup_order_string(info->iter.cgroup.order));
220 	}
221 }
222 
223 void netfilter_dump_json(const struct bpf_link_info *info, json_writer_t *wtr)
224 {
225 	jsonw_uint_field(json_wtr, "pf",
226 			 info->netfilter.pf);
227 	jsonw_uint_field(json_wtr, "hook",
228 			 info->netfilter.hooknum);
229 	jsonw_int_field(json_wtr, "prio",
230 			 info->netfilter.priority);
231 	jsonw_uint_field(json_wtr, "flags",
232 			 info->netfilter.flags);
233 }
234 
235 static int get_prog_info(int prog_id, struct bpf_prog_info *info)
236 {
237 	__u32 len = sizeof(*info);
238 	int err, prog_fd;
239 
240 	prog_fd = bpf_prog_get_fd_by_id(prog_id);
241 	if (prog_fd < 0)
242 		return prog_fd;
243 
244 	memset(info, 0, sizeof(*info));
245 	err = bpf_prog_get_info_by_fd(prog_fd, info, &len);
246 	if (err)
247 		p_err("can't get prog info: %s", strerror(errno));
248 	close(prog_fd);
249 	return err;
250 }
251 
252 static int cmp_u64(const void *A, const void *B)
253 {
254 	const __u64 *a = A, *b = B;
255 
256 	return *a - *b;
257 }
258 
259 static void
260 show_kprobe_multi_json(struct bpf_link_info *info, json_writer_t *wtr)
261 {
262 	__u32 i, j = 0;
263 	__u64 *addrs;
264 
265 	jsonw_bool_field(json_wtr, "retprobe",
266 			 info->kprobe_multi.flags & BPF_F_KPROBE_MULTI_RETURN);
267 	jsonw_uint_field(json_wtr, "func_cnt", info->kprobe_multi.count);
268 	jsonw_name(json_wtr, "funcs");
269 	jsonw_start_array(json_wtr);
270 	addrs = u64_to_ptr(info->kprobe_multi.addrs);
271 	qsort(addrs, info->kprobe_multi.count, sizeof(addrs[0]), cmp_u64);
272 
273 	/* Load it once for all. */
274 	if (!dd.sym_count)
275 		kernel_syms_load(&dd);
276 	for (i = 0; i < dd.sym_count; i++) {
277 		if (dd.sym_mapping[i].address != addrs[j])
278 			continue;
279 		jsonw_start_object(json_wtr);
280 		jsonw_uint_field(json_wtr, "addr", dd.sym_mapping[i].address);
281 		jsonw_string_field(json_wtr, "func", dd.sym_mapping[i].name);
282 		/* Print null if it is vmlinux */
283 		if (dd.sym_mapping[i].module[0] == '\0') {
284 			jsonw_name(json_wtr, "module");
285 			jsonw_null(json_wtr);
286 		} else {
287 			jsonw_string_field(json_wtr, "module", dd.sym_mapping[i].module);
288 		}
289 		jsonw_end_object(json_wtr);
290 		if (j++ == info->kprobe_multi.count)
291 			break;
292 	}
293 	jsonw_end_array(json_wtr);
294 }
295 
296 static void
297 show_perf_event_kprobe_json(struct bpf_link_info *info, json_writer_t *wtr)
298 {
299 	jsonw_bool_field(wtr, "retprobe", info->perf_event.type == BPF_PERF_EVENT_KRETPROBE);
300 	jsonw_uint_field(wtr, "addr", info->perf_event.kprobe.addr);
301 	jsonw_string_field(wtr, "func",
302 			   u64_to_ptr(info->perf_event.kprobe.func_name));
303 	jsonw_uint_field(wtr, "offset", info->perf_event.kprobe.offset);
304 }
305 
306 static void
307 show_perf_event_uprobe_json(struct bpf_link_info *info, json_writer_t *wtr)
308 {
309 	jsonw_bool_field(wtr, "retprobe", info->perf_event.type == BPF_PERF_EVENT_URETPROBE);
310 	jsonw_string_field(wtr, "file",
311 			   u64_to_ptr(info->perf_event.uprobe.file_name));
312 	jsonw_uint_field(wtr, "offset", info->perf_event.uprobe.offset);
313 }
314 
315 static void
316 show_perf_event_tracepoint_json(struct bpf_link_info *info, json_writer_t *wtr)
317 {
318 	jsonw_string_field(wtr, "tracepoint",
319 			   u64_to_ptr(info->perf_event.tracepoint.tp_name));
320 }
321 
322 static char *perf_config_hw_cache_str(__u64 config)
323 {
324 	const char *hw_cache, *result, *op;
325 	char *str = malloc(PERF_HW_CACHE_LEN);
326 
327 	if (!str) {
328 		p_err("mem alloc failed");
329 		return NULL;
330 	}
331 
332 	hw_cache = perf_event_name(evsel__hw_cache, config & 0xff);
333 	if (hw_cache)
334 		snprintf(str, PERF_HW_CACHE_LEN, "%s-", hw_cache);
335 	else
336 		snprintf(str, PERF_HW_CACHE_LEN, "%lld-", config & 0xff);
337 
338 	op = perf_event_name(evsel__hw_cache_op, (config >> 8) & 0xff);
339 	if (op)
340 		snprintf(str + strlen(str), PERF_HW_CACHE_LEN - strlen(str),
341 			 "%s-", op);
342 	else
343 		snprintf(str + strlen(str), PERF_HW_CACHE_LEN - strlen(str),
344 			 "%lld-", (config >> 8) & 0xff);
345 
346 	result = perf_event_name(evsel__hw_cache_result, config >> 16);
347 	if (result)
348 		snprintf(str + strlen(str), PERF_HW_CACHE_LEN - strlen(str),
349 			 "%s", result);
350 	else
351 		snprintf(str + strlen(str), PERF_HW_CACHE_LEN - strlen(str),
352 			 "%lld", config >> 16);
353 	return str;
354 }
355 
356 static const char *perf_config_str(__u32 type, __u64 config)
357 {
358 	const char *perf_config;
359 
360 	switch (type) {
361 	case PERF_TYPE_HARDWARE:
362 		perf_config = perf_event_name(event_symbols_hw, config);
363 		break;
364 	case PERF_TYPE_SOFTWARE:
365 		perf_config = perf_event_name(event_symbols_sw, config);
366 		break;
367 	case PERF_TYPE_HW_CACHE:
368 		perf_config = perf_config_hw_cache_str(config);
369 		break;
370 	default:
371 		perf_config = NULL;
372 		break;
373 	}
374 	return perf_config;
375 }
376 
377 static void
378 show_perf_event_event_json(struct bpf_link_info *info, json_writer_t *wtr)
379 {
380 	__u64 config = info->perf_event.event.config;
381 	__u32 type = info->perf_event.event.type;
382 	const char *perf_type, *perf_config;
383 
384 	perf_type = perf_event_name(perf_type_name, type);
385 	if (perf_type)
386 		jsonw_string_field(wtr, "event_type", perf_type);
387 	else
388 		jsonw_uint_field(wtr, "event_type", type);
389 
390 	perf_config = perf_config_str(type, config);
391 	if (perf_config)
392 		jsonw_string_field(wtr, "event_config", perf_config);
393 	else
394 		jsonw_uint_field(wtr, "event_config", config);
395 
396 	if (type == PERF_TYPE_HW_CACHE && perf_config)
397 		free((void *)perf_config);
398 }
399 
400 static int show_link_close_json(int fd, struct bpf_link_info *info)
401 {
402 	struct bpf_prog_info prog_info;
403 	const char *prog_type_str;
404 	int err;
405 
406 	jsonw_start_object(json_wtr);
407 
408 	show_link_header_json(info, json_wtr);
409 
410 	switch (info->type) {
411 	case BPF_LINK_TYPE_RAW_TRACEPOINT:
412 		jsonw_string_field(json_wtr, "tp_name",
413 				   u64_to_ptr(info->raw_tracepoint.tp_name));
414 		break;
415 	case BPF_LINK_TYPE_TRACING:
416 		err = get_prog_info(info->prog_id, &prog_info);
417 		if (err)
418 			return err;
419 
420 		prog_type_str = libbpf_bpf_prog_type_str(prog_info.type);
421 		/* libbpf will return NULL for variants unknown to it. */
422 		if (prog_type_str)
423 			jsonw_string_field(json_wtr, "prog_type", prog_type_str);
424 		else
425 			jsonw_uint_field(json_wtr, "prog_type", prog_info.type);
426 
427 		show_link_attach_type_json(info->tracing.attach_type,
428 					   json_wtr);
429 		jsonw_uint_field(json_wtr, "target_obj_id", info->tracing.target_obj_id);
430 		jsonw_uint_field(json_wtr, "target_btf_id", info->tracing.target_btf_id);
431 		break;
432 	case BPF_LINK_TYPE_CGROUP:
433 		jsonw_lluint_field(json_wtr, "cgroup_id",
434 				   info->cgroup.cgroup_id);
435 		show_link_attach_type_json(info->cgroup.attach_type, json_wtr);
436 		break;
437 	case BPF_LINK_TYPE_ITER:
438 		show_iter_json(info, json_wtr);
439 		break;
440 	case BPF_LINK_TYPE_NETNS:
441 		jsonw_uint_field(json_wtr, "netns_ino",
442 				 info->netns.netns_ino);
443 		show_link_attach_type_json(info->netns.attach_type, json_wtr);
444 		break;
445 	case BPF_LINK_TYPE_NETFILTER:
446 		netfilter_dump_json(info, json_wtr);
447 		break;
448 	case BPF_LINK_TYPE_TCX:
449 		show_link_ifindex_json(info->tcx.ifindex, json_wtr);
450 		show_link_attach_type_json(info->tcx.attach_type, json_wtr);
451 		break;
452 	case BPF_LINK_TYPE_XDP:
453 		show_link_ifindex_json(info->xdp.ifindex, json_wtr);
454 		break;
455 	case BPF_LINK_TYPE_STRUCT_OPS:
456 		jsonw_uint_field(json_wtr, "map_id",
457 				 info->struct_ops.map_id);
458 		break;
459 	case BPF_LINK_TYPE_KPROBE_MULTI:
460 		show_kprobe_multi_json(info, json_wtr);
461 		break;
462 	case BPF_LINK_TYPE_PERF_EVENT:
463 		switch (info->perf_event.type) {
464 		case BPF_PERF_EVENT_EVENT:
465 			show_perf_event_event_json(info, json_wtr);
466 			break;
467 		case BPF_PERF_EVENT_TRACEPOINT:
468 			show_perf_event_tracepoint_json(info, json_wtr);
469 			break;
470 		case BPF_PERF_EVENT_KPROBE:
471 		case BPF_PERF_EVENT_KRETPROBE:
472 			show_perf_event_kprobe_json(info, json_wtr);
473 			break;
474 		case BPF_PERF_EVENT_UPROBE:
475 		case BPF_PERF_EVENT_URETPROBE:
476 			show_perf_event_uprobe_json(info, json_wtr);
477 			break;
478 		default:
479 			break;
480 		}
481 		break;
482 	default:
483 		break;
484 	}
485 
486 	if (!hashmap__empty(link_table)) {
487 		struct hashmap_entry *entry;
488 
489 		jsonw_name(json_wtr, "pinned");
490 		jsonw_start_array(json_wtr);
491 		hashmap__for_each_key_entry(link_table, entry, info->id)
492 			jsonw_string(json_wtr, entry->pvalue);
493 		jsonw_end_array(json_wtr);
494 	}
495 
496 	emit_obj_refs_json(refs_table, info->id, json_wtr);
497 
498 	jsonw_end_object(json_wtr);
499 
500 	return 0;
501 }
502 
503 static void show_link_header_plain(struct bpf_link_info *info)
504 {
505 	const char *link_type_str;
506 
507 	printf("%u: ", info->id);
508 	link_type_str = libbpf_bpf_link_type_str(info->type);
509 	if (link_type_str)
510 		printf("%s  ", link_type_str);
511 	else
512 		printf("type %u  ", info->type);
513 
514 	if (info->type == BPF_LINK_TYPE_STRUCT_OPS)
515 		printf("map %u  ", info->struct_ops.map_id);
516 	else
517 		printf("prog %u  ", info->prog_id);
518 }
519 
520 static void show_link_attach_type_plain(__u32 attach_type)
521 {
522 	const char *attach_type_str;
523 
524 	attach_type_str = libbpf_bpf_attach_type_str(attach_type);
525 	if (attach_type_str)
526 		printf("attach_type %s  ", attach_type_str);
527 	else
528 		printf("attach_type %u  ", attach_type);
529 }
530 
531 static void show_link_ifindex_plain(__u32 ifindex)
532 {
533 	char devname[IF_NAMESIZE * 2] = "(unknown)";
534 	char tmpname[IF_NAMESIZE];
535 	char *ret = NULL;
536 
537 	if (ifindex)
538 		ret = if_indextoname(ifindex, tmpname);
539 	else
540 		snprintf(devname, sizeof(devname), "(detached)");
541 	if (ret)
542 		snprintf(devname, sizeof(devname), "%s(%d)",
543 			 tmpname, ifindex);
544 	printf("ifindex %s  ", devname);
545 }
546 
547 static void show_iter_plain(struct bpf_link_info *info)
548 {
549 	const char *target_name = u64_to_ptr(info->iter.target_name);
550 
551 	printf("target_name %s  ", target_name);
552 
553 	if (is_iter_map_target(target_name))
554 		printf("map_id %u  ", info->iter.map.map_id);
555 	else if (is_iter_task_target(target_name)) {
556 		if (info->iter.task.tid)
557 			printf("tid %u ", info->iter.task.tid);
558 		else if (info->iter.task.pid)
559 			printf("pid %u ", info->iter.task.pid);
560 	}
561 
562 	if (is_iter_cgroup_target(target_name)) {
563 		printf("cgroup_id %llu  ", info->iter.cgroup.cgroup_id);
564 		printf("order %s  ",
565 		       cgroup_order_string(info->iter.cgroup.order));
566 	}
567 }
568 
569 static const char * const pf2name[] = {
570 	[NFPROTO_INET] = "inet",
571 	[NFPROTO_IPV4] = "ip",
572 	[NFPROTO_ARP] = "arp",
573 	[NFPROTO_NETDEV] = "netdev",
574 	[NFPROTO_BRIDGE] = "bridge",
575 	[NFPROTO_IPV6] = "ip6",
576 };
577 
578 static const char * const inethook2name[] = {
579 	[NF_INET_PRE_ROUTING] = "prerouting",
580 	[NF_INET_LOCAL_IN] = "input",
581 	[NF_INET_FORWARD] = "forward",
582 	[NF_INET_LOCAL_OUT] = "output",
583 	[NF_INET_POST_ROUTING] = "postrouting",
584 };
585 
586 static const char * const arphook2name[] = {
587 	[NF_ARP_IN] = "input",
588 	[NF_ARP_OUT] = "output",
589 };
590 
591 void netfilter_dump_plain(const struct bpf_link_info *info)
592 {
593 	const char *hookname = NULL, *pfname = NULL;
594 	unsigned int hook = info->netfilter.hooknum;
595 	unsigned int pf = info->netfilter.pf;
596 
597 	if (pf < ARRAY_SIZE(pf2name))
598 		pfname = pf2name[pf];
599 
600 	switch (pf) {
601 	case NFPROTO_BRIDGE: /* bridge shares numbers with enum nf_inet_hooks */
602 	case NFPROTO_IPV4:
603 	case NFPROTO_IPV6:
604 	case NFPROTO_INET:
605 		if (hook < ARRAY_SIZE(inethook2name))
606 			hookname = inethook2name[hook];
607 		break;
608 	case NFPROTO_ARP:
609 		if (hook < ARRAY_SIZE(arphook2name))
610 			hookname = arphook2name[hook];
611 	default:
612 		break;
613 	}
614 
615 	if (pfname)
616 		printf("\n\t%s", pfname);
617 	else
618 		printf("\n\tpf: %d", pf);
619 
620 	if (hookname)
621 		printf(" %s", hookname);
622 	else
623 		printf(", hook %u,", hook);
624 
625 	printf(" prio %d", info->netfilter.priority);
626 
627 	if (info->netfilter.flags)
628 		printf(" flags 0x%x", info->netfilter.flags);
629 }
630 
631 static void show_kprobe_multi_plain(struct bpf_link_info *info)
632 {
633 	__u32 i, j = 0;
634 	__u64 *addrs;
635 
636 	if (!info->kprobe_multi.count)
637 		return;
638 
639 	if (info->kprobe_multi.flags & BPF_F_KPROBE_MULTI_RETURN)
640 		printf("\n\tkretprobe.multi  ");
641 	else
642 		printf("\n\tkprobe.multi  ");
643 	printf("func_cnt %u  ", info->kprobe_multi.count);
644 	addrs = (__u64 *)u64_to_ptr(info->kprobe_multi.addrs);
645 	qsort(addrs, info->kprobe_multi.count, sizeof(__u64), cmp_u64);
646 
647 	/* Load it once for all. */
648 	if (!dd.sym_count)
649 		kernel_syms_load(&dd);
650 	if (!dd.sym_count)
651 		return;
652 
653 	printf("\n\t%-16s %s", "addr", "func [module]");
654 	for (i = 0; i < dd.sym_count; i++) {
655 		if (dd.sym_mapping[i].address != addrs[j])
656 			continue;
657 		printf("\n\t%016lx %s",
658 		       dd.sym_mapping[i].address, dd.sym_mapping[i].name);
659 		if (dd.sym_mapping[i].module[0] != '\0')
660 			printf(" [%s]  ", dd.sym_mapping[i].module);
661 		else
662 			printf("  ");
663 
664 		if (j++ == info->kprobe_multi.count)
665 			break;
666 	}
667 }
668 
669 static void show_perf_event_kprobe_plain(struct bpf_link_info *info)
670 {
671 	const char *buf;
672 
673 	buf = u64_to_ptr(info->perf_event.kprobe.func_name);
674 	if (buf[0] == '\0' && !info->perf_event.kprobe.addr)
675 		return;
676 
677 	if (info->perf_event.type == BPF_PERF_EVENT_KRETPROBE)
678 		printf("\n\tkretprobe ");
679 	else
680 		printf("\n\tkprobe ");
681 	if (info->perf_event.kprobe.addr)
682 		printf("%llx ", info->perf_event.kprobe.addr);
683 	printf("%s", buf);
684 	if (info->perf_event.kprobe.offset)
685 		printf("+%#x", info->perf_event.kprobe.offset);
686 	printf("  ");
687 }
688 
689 static void show_perf_event_uprobe_plain(struct bpf_link_info *info)
690 {
691 	const char *buf;
692 
693 	buf = u64_to_ptr(info->perf_event.uprobe.file_name);
694 	if (buf[0] == '\0')
695 		return;
696 
697 	if (info->perf_event.type == BPF_PERF_EVENT_URETPROBE)
698 		printf("\n\turetprobe ");
699 	else
700 		printf("\n\tuprobe ");
701 	printf("%s+%#x  ", buf, info->perf_event.uprobe.offset);
702 }
703 
704 static void show_perf_event_tracepoint_plain(struct bpf_link_info *info)
705 {
706 	const char *buf;
707 
708 	buf = u64_to_ptr(info->perf_event.tracepoint.tp_name);
709 	if (buf[0] == '\0')
710 		return;
711 
712 	printf("\n\ttracepoint %s  ", buf);
713 }
714 
715 static void show_perf_event_event_plain(struct bpf_link_info *info)
716 {
717 	__u64 config = info->perf_event.event.config;
718 	__u32 type = info->perf_event.event.type;
719 	const char *perf_type, *perf_config;
720 
721 	printf("\n\tevent ");
722 	perf_type = perf_event_name(perf_type_name, type);
723 	if (perf_type)
724 		printf("%s:", perf_type);
725 	else
726 		printf("%u :", type);
727 
728 	perf_config = perf_config_str(type, config);
729 	if (perf_config)
730 		printf("%s  ", perf_config);
731 	else
732 		printf("%llu  ", config);
733 
734 	if (type == PERF_TYPE_HW_CACHE && perf_config)
735 		free((void *)perf_config);
736 }
737 
738 static int show_link_close_plain(int fd, struct bpf_link_info *info)
739 {
740 	struct bpf_prog_info prog_info;
741 	const char *prog_type_str;
742 	int err;
743 
744 	show_link_header_plain(info);
745 
746 	switch (info->type) {
747 	case BPF_LINK_TYPE_RAW_TRACEPOINT:
748 		printf("\n\ttp '%s'  ",
749 		       (const char *)u64_to_ptr(info->raw_tracepoint.tp_name));
750 		break;
751 	case BPF_LINK_TYPE_TRACING:
752 		err = get_prog_info(info->prog_id, &prog_info);
753 		if (err)
754 			return err;
755 
756 		prog_type_str = libbpf_bpf_prog_type_str(prog_info.type);
757 		/* libbpf will return NULL for variants unknown to it. */
758 		if (prog_type_str)
759 			printf("\n\tprog_type %s  ", prog_type_str);
760 		else
761 			printf("\n\tprog_type %u  ", prog_info.type);
762 
763 		show_link_attach_type_plain(info->tracing.attach_type);
764 		if (info->tracing.target_obj_id || info->tracing.target_btf_id)
765 			printf("\n\ttarget_obj_id %u  target_btf_id %u  ",
766 			       info->tracing.target_obj_id,
767 			       info->tracing.target_btf_id);
768 		break;
769 	case BPF_LINK_TYPE_CGROUP:
770 		printf("\n\tcgroup_id %zu  ", (size_t)info->cgroup.cgroup_id);
771 		show_link_attach_type_plain(info->cgroup.attach_type);
772 		break;
773 	case BPF_LINK_TYPE_ITER:
774 		show_iter_plain(info);
775 		break;
776 	case BPF_LINK_TYPE_NETNS:
777 		printf("\n\tnetns_ino %u  ", info->netns.netns_ino);
778 		show_link_attach_type_plain(info->netns.attach_type);
779 		break;
780 	case BPF_LINK_TYPE_NETFILTER:
781 		netfilter_dump_plain(info);
782 		break;
783 	case BPF_LINK_TYPE_TCX:
784 		printf("\n\t");
785 		show_link_ifindex_plain(info->tcx.ifindex);
786 		show_link_attach_type_plain(info->tcx.attach_type);
787 		break;
788 	case BPF_LINK_TYPE_XDP:
789 		printf("\n\t");
790 		show_link_ifindex_plain(info->xdp.ifindex);
791 		break;
792 	case BPF_LINK_TYPE_KPROBE_MULTI:
793 		show_kprobe_multi_plain(info);
794 		break;
795 	case BPF_LINK_TYPE_PERF_EVENT:
796 		switch (info->perf_event.type) {
797 		case BPF_PERF_EVENT_EVENT:
798 			show_perf_event_event_plain(info);
799 			break;
800 		case BPF_PERF_EVENT_TRACEPOINT:
801 			show_perf_event_tracepoint_plain(info);
802 			break;
803 		case BPF_PERF_EVENT_KPROBE:
804 		case BPF_PERF_EVENT_KRETPROBE:
805 			show_perf_event_kprobe_plain(info);
806 			break;
807 		case BPF_PERF_EVENT_UPROBE:
808 		case BPF_PERF_EVENT_URETPROBE:
809 			show_perf_event_uprobe_plain(info);
810 			break;
811 		default:
812 			break;
813 		}
814 		break;
815 	default:
816 		break;
817 	}
818 
819 	if (!hashmap__empty(link_table)) {
820 		struct hashmap_entry *entry;
821 
822 		hashmap__for_each_key_entry(link_table, entry, info->id)
823 			printf("\n\tpinned %s", (char *)entry->pvalue);
824 	}
825 	emit_obj_refs_plain(refs_table, info->id, "\n\tpids ");
826 
827 	printf("\n");
828 
829 	return 0;
830 }
831 
832 static int do_show_link(int fd)
833 {
834 	struct bpf_link_info info;
835 	__u32 len = sizeof(info);
836 	__u64 *addrs = NULL;
837 	char buf[PATH_MAX];
838 	int count;
839 	int err;
840 
841 	memset(&info, 0, sizeof(info));
842 	buf[0] = '\0';
843 again:
844 	err = bpf_link_get_info_by_fd(fd, &info, &len);
845 	if (err) {
846 		p_err("can't get link info: %s",
847 		      strerror(errno));
848 		close(fd);
849 		return err;
850 	}
851 	if (info.type == BPF_LINK_TYPE_RAW_TRACEPOINT &&
852 	    !info.raw_tracepoint.tp_name) {
853 		info.raw_tracepoint.tp_name = ptr_to_u64(&buf);
854 		info.raw_tracepoint.tp_name_len = sizeof(buf);
855 		goto again;
856 	}
857 	if (info.type == BPF_LINK_TYPE_ITER &&
858 	    !info.iter.target_name) {
859 		info.iter.target_name = ptr_to_u64(&buf);
860 		info.iter.target_name_len = sizeof(buf);
861 		goto again;
862 	}
863 	if (info.type == BPF_LINK_TYPE_KPROBE_MULTI &&
864 	    !info.kprobe_multi.addrs) {
865 		count = info.kprobe_multi.count;
866 		if (count) {
867 			addrs = calloc(count, sizeof(__u64));
868 			if (!addrs) {
869 				p_err("mem alloc failed");
870 				close(fd);
871 				return -ENOMEM;
872 			}
873 			info.kprobe_multi.addrs = ptr_to_u64(addrs);
874 			goto again;
875 		}
876 	}
877 	if (info.type == BPF_LINK_TYPE_PERF_EVENT) {
878 		switch (info.perf_event.type) {
879 		case BPF_PERF_EVENT_TRACEPOINT:
880 			if (!info.perf_event.tracepoint.tp_name) {
881 				info.perf_event.tracepoint.tp_name = ptr_to_u64(&buf);
882 				info.perf_event.tracepoint.name_len = sizeof(buf);
883 				goto again;
884 			}
885 			break;
886 		case BPF_PERF_EVENT_KPROBE:
887 		case BPF_PERF_EVENT_KRETPROBE:
888 			if (!info.perf_event.kprobe.func_name) {
889 				info.perf_event.kprobe.func_name = ptr_to_u64(&buf);
890 				info.perf_event.kprobe.name_len = sizeof(buf);
891 				goto again;
892 			}
893 			break;
894 		case BPF_PERF_EVENT_UPROBE:
895 		case BPF_PERF_EVENT_URETPROBE:
896 			if (!info.perf_event.uprobe.file_name) {
897 				info.perf_event.uprobe.file_name = ptr_to_u64(&buf);
898 				info.perf_event.uprobe.name_len = sizeof(buf);
899 				goto again;
900 			}
901 			break;
902 		default:
903 			break;
904 		}
905 	}
906 
907 	if (json_output)
908 		show_link_close_json(fd, &info);
909 	else
910 		show_link_close_plain(fd, &info);
911 
912 	if (addrs)
913 		free(addrs);
914 	close(fd);
915 	return 0;
916 }
917 
918 static int do_show(int argc, char **argv)
919 {
920 	__u32 id = 0;
921 	int err, fd;
922 
923 	if (show_pinned) {
924 		link_table = hashmap__new(hash_fn_for_key_as_id,
925 					  equal_fn_for_key_as_id, NULL);
926 		if (IS_ERR(link_table)) {
927 			p_err("failed to create hashmap for pinned paths");
928 			return -1;
929 		}
930 		build_pinned_obj_table(link_table, BPF_OBJ_LINK);
931 	}
932 	build_obj_refs_table(&refs_table, BPF_OBJ_LINK);
933 
934 	if (argc == 2) {
935 		fd = link_parse_fd(&argc, &argv);
936 		if (fd < 0)
937 			return fd;
938 		do_show_link(fd);
939 		goto out;
940 	}
941 
942 	if (argc)
943 		return BAD_ARG();
944 
945 	if (json_output)
946 		jsonw_start_array(json_wtr);
947 	while (true) {
948 		err = bpf_link_get_next_id(id, &id);
949 		if (err) {
950 			if (errno == ENOENT)
951 				break;
952 			p_err("can't get next link: %s%s", strerror(errno),
953 			      errno == EINVAL ? " -- kernel too old?" : "");
954 			break;
955 		}
956 
957 		fd = bpf_link_get_fd_by_id(id);
958 		if (fd < 0) {
959 			if (errno == ENOENT)
960 				continue;
961 			p_err("can't get link by id (%u): %s",
962 			      id, strerror(errno));
963 			break;
964 		}
965 
966 		err = do_show_link(fd);
967 		if (err)
968 			break;
969 	}
970 	if (json_output)
971 		jsonw_end_array(json_wtr);
972 
973 	delete_obj_refs_table(refs_table);
974 
975 	if (show_pinned)
976 		delete_pinned_obj_table(link_table);
977 
978 out:
979 	if (dd.sym_count)
980 		kernel_syms_destroy(&dd);
981 	return errno == ENOENT ? 0 : -1;
982 }
983 
984 static int do_pin(int argc, char **argv)
985 {
986 	int err;
987 
988 	err = do_pin_any(argc, argv, link_parse_fd);
989 	if (!err && json_output)
990 		jsonw_null(json_wtr);
991 	return err;
992 }
993 
994 static int do_detach(int argc, char **argv)
995 {
996 	int err, fd;
997 
998 	if (argc != 2) {
999 		p_err("link specifier is invalid or missing\n");
1000 		return 1;
1001 	}
1002 
1003 	fd = link_parse_fd(&argc, &argv);
1004 	if (fd < 0)
1005 		return 1;
1006 
1007 	err = bpf_link_detach(fd);
1008 	if (err)
1009 		err = -errno;
1010 	close(fd);
1011 	if (err) {
1012 		p_err("failed link detach: %s", strerror(-err));
1013 		return 1;
1014 	}
1015 
1016 	if (json_output)
1017 		jsonw_null(json_wtr);
1018 
1019 	return 0;
1020 }
1021 
1022 static int do_help(int argc, char **argv)
1023 {
1024 	if (json_output) {
1025 		jsonw_null(json_wtr);
1026 		return 0;
1027 	}
1028 
1029 	fprintf(stderr,
1030 		"Usage: %1$s %2$s { show | list }   [LINK]\n"
1031 		"       %1$s %2$s pin        LINK  FILE\n"
1032 		"       %1$s %2$s detach     LINK\n"
1033 		"       %1$s %2$s help\n"
1034 		"\n"
1035 		"       " HELP_SPEC_LINK "\n"
1036 		"       " HELP_SPEC_OPTIONS " |\n"
1037 		"                    {-f|--bpffs} | {-n|--nomount} }\n"
1038 		"",
1039 		bin_name, argv[-2]);
1040 
1041 	return 0;
1042 }
1043 
1044 static const struct cmd cmds[] = {
1045 	{ "show",	do_show },
1046 	{ "list",	do_show },
1047 	{ "help",	do_help },
1048 	{ "pin",	do_pin },
1049 	{ "detach",	do_detach },
1050 	{ 0 }
1051 };
1052 
1053 int do_link(int argc, char **argv)
1054 {
1055 	return cmd_select(cmds, argc, argv, do_help);
1056 }
1057