xref: /linux/tools/bpf/bpftool/link.c (revision aece2094e34e602f37403dda028f464bb41da50c)
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_uint_field(json_wtr, "missed", info->kprobe_multi.missed);
269 	jsonw_name(json_wtr, "funcs");
270 	jsonw_start_array(json_wtr);
271 	addrs = u64_to_ptr(info->kprobe_multi.addrs);
272 	qsort(addrs, info->kprobe_multi.count, sizeof(addrs[0]), cmp_u64);
273 
274 	/* Load it once for all. */
275 	if (!dd.sym_count)
276 		kernel_syms_load(&dd);
277 	for (i = 0; i < dd.sym_count; i++) {
278 		if (dd.sym_mapping[i].address != addrs[j])
279 			continue;
280 		jsonw_start_object(json_wtr);
281 		jsonw_uint_field(json_wtr, "addr", dd.sym_mapping[i].address);
282 		jsonw_string_field(json_wtr, "func", dd.sym_mapping[i].name);
283 		/* Print null if it is vmlinux */
284 		if (dd.sym_mapping[i].module[0] == '\0') {
285 			jsonw_name(json_wtr, "module");
286 			jsonw_null(json_wtr);
287 		} else {
288 			jsonw_string_field(json_wtr, "module", dd.sym_mapping[i].module);
289 		}
290 		jsonw_end_object(json_wtr);
291 		if (j++ == info->kprobe_multi.count)
292 			break;
293 	}
294 	jsonw_end_array(json_wtr);
295 }
296 
297 static __u64 *u64_to_arr(__u64 val)
298 {
299 	return (__u64 *) u64_to_ptr(val);
300 }
301 
302 static void
303 show_uprobe_multi_json(struct bpf_link_info *info, json_writer_t *wtr)
304 {
305 	__u32 i;
306 
307 	jsonw_bool_field(json_wtr, "retprobe",
308 			 info->uprobe_multi.flags & BPF_F_UPROBE_MULTI_RETURN);
309 	jsonw_string_field(json_wtr, "path", (char *) u64_to_ptr(info->uprobe_multi.path));
310 	jsonw_uint_field(json_wtr, "func_cnt", info->uprobe_multi.count);
311 	jsonw_int_field(json_wtr, "pid", (int) info->uprobe_multi.pid);
312 	jsonw_name(json_wtr, "funcs");
313 	jsonw_start_array(json_wtr);
314 
315 	for (i = 0; i < info->uprobe_multi.count; i++) {
316 		jsonw_start_object(json_wtr);
317 		jsonw_uint_field(json_wtr, "offset",
318 				 u64_to_arr(info->uprobe_multi.offsets)[i]);
319 		jsonw_uint_field(json_wtr, "ref_ctr_offset",
320 				 u64_to_arr(info->uprobe_multi.ref_ctr_offsets)[i]);
321 		jsonw_uint_field(json_wtr, "cookie",
322 				 u64_to_arr(info->uprobe_multi.cookies)[i]);
323 		jsonw_end_object(json_wtr);
324 	}
325 	jsonw_end_array(json_wtr);
326 }
327 
328 static void
329 show_perf_event_kprobe_json(struct bpf_link_info *info, json_writer_t *wtr)
330 {
331 	jsonw_bool_field(wtr, "retprobe", info->perf_event.type == BPF_PERF_EVENT_KRETPROBE);
332 	jsonw_uint_field(wtr, "addr", info->perf_event.kprobe.addr);
333 	jsonw_string_field(wtr, "func",
334 			   u64_to_ptr(info->perf_event.kprobe.func_name));
335 	jsonw_uint_field(wtr, "offset", info->perf_event.kprobe.offset);
336 	jsonw_uint_field(wtr, "missed", info->perf_event.kprobe.missed);
337 }
338 
339 static void
340 show_perf_event_uprobe_json(struct bpf_link_info *info, json_writer_t *wtr)
341 {
342 	jsonw_bool_field(wtr, "retprobe", info->perf_event.type == BPF_PERF_EVENT_URETPROBE);
343 	jsonw_string_field(wtr, "file",
344 			   u64_to_ptr(info->perf_event.uprobe.file_name));
345 	jsonw_uint_field(wtr, "offset", info->perf_event.uprobe.offset);
346 }
347 
348 static void
349 show_perf_event_tracepoint_json(struct bpf_link_info *info, json_writer_t *wtr)
350 {
351 	jsonw_string_field(wtr, "tracepoint",
352 			   u64_to_ptr(info->perf_event.tracepoint.tp_name));
353 }
354 
355 static char *perf_config_hw_cache_str(__u64 config)
356 {
357 	const char *hw_cache, *result, *op;
358 	char *str = malloc(PERF_HW_CACHE_LEN);
359 
360 	if (!str) {
361 		p_err("mem alloc failed");
362 		return NULL;
363 	}
364 
365 	hw_cache = perf_event_name(evsel__hw_cache, config & 0xff);
366 	if (hw_cache)
367 		snprintf(str, PERF_HW_CACHE_LEN, "%s-", hw_cache);
368 	else
369 		snprintf(str, PERF_HW_CACHE_LEN, "%lld-", config & 0xff);
370 
371 	op = perf_event_name(evsel__hw_cache_op, (config >> 8) & 0xff);
372 	if (op)
373 		snprintf(str + strlen(str), PERF_HW_CACHE_LEN - strlen(str),
374 			 "%s-", op);
375 	else
376 		snprintf(str + strlen(str), PERF_HW_CACHE_LEN - strlen(str),
377 			 "%lld-", (config >> 8) & 0xff);
378 
379 	result = perf_event_name(evsel__hw_cache_result, config >> 16);
380 	if (result)
381 		snprintf(str + strlen(str), PERF_HW_CACHE_LEN - strlen(str),
382 			 "%s", result);
383 	else
384 		snprintf(str + strlen(str), PERF_HW_CACHE_LEN - strlen(str),
385 			 "%lld", config >> 16);
386 	return str;
387 }
388 
389 static const char *perf_config_str(__u32 type, __u64 config)
390 {
391 	const char *perf_config;
392 
393 	switch (type) {
394 	case PERF_TYPE_HARDWARE:
395 		perf_config = perf_event_name(event_symbols_hw, config);
396 		break;
397 	case PERF_TYPE_SOFTWARE:
398 		perf_config = perf_event_name(event_symbols_sw, config);
399 		break;
400 	case PERF_TYPE_HW_CACHE:
401 		perf_config = perf_config_hw_cache_str(config);
402 		break;
403 	default:
404 		perf_config = NULL;
405 		break;
406 	}
407 	return perf_config;
408 }
409 
410 static void
411 show_perf_event_event_json(struct bpf_link_info *info, json_writer_t *wtr)
412 {
413 	__u64 config = info->perf_event.event.config;
414 	__u32 type = info->perf_event.event.type;
415 	const char *perf_type, *perf_config;
416 
417 	perf_type = perf_event_name(perf_type_name, type);
418 	if (perf_type)
419 		jsonw_string_field(wtr, "event_type", perf_type);
420 	else
421 		jsonw_uint_field(wtr, "event_type", type);
422 
423 	perf_config = perf_config_str(type, config);
424 	if (perf_config)
425 		jsonw_string_field(wtr, "event_config", perf_config);
426 	else
427 		jsonw_uint_field(wtr, "event_config", config);
428 
429 	if (type == PERF_TYPE_HW_CACHE && perf_config)
430 		free((void *)perf_config);
431 }
432 
433 static int show_link_close_json(int fd, struct bpf_link_info *info)
434 {
435 	struct bpf_prog_info prog_info;
436 	const char *prog_type_str;
437 	int err;
438 
439 	jsonw_start_object(json_wtr);
440 
441 	show_link_header_json(info, json_wtr);
442 
443 	switch (info->type) {
444 	case BPF_LINK_TYPE_RAW_TRACEPOINT:
445 		jsonw_string_field(json_wtr, "tp_name",
446 				   u64_to_ptr(info->raw_tracepoint.tp_name));
447 		break;
448 	case BPF_LINK_TYPE_TRACING:
449 		err = get_prog_info(info->prog_id, &prog_info);
450 		if (err)
451 			return err;
452 
453 		prog_type_str = libbpf_bpf_prog_type_str(prog_info.type);
454 		/* libbpf will return NULL for variants unknown to it. */
455 		if (prog_type_str)
456 			jsonw_string_field(json_wtr, "prog_type", prog_type_str);
457 		else
458 			jsonw_uint_field(json_wtr, "prog_type", prog_info.type);
459 
460 		show_link_attach_type_json(info->tracing.attach_type,
461 					   json_wtr);
462 		jsonw_uint_field(json_wtr, "target_obj_id", info->tracing.target_obj_id);
463 		jsonw_uint_field(json_wtr, "target_btf_id", info->tracing.target_btf_id);
464 		break;
465 	case BPF_LINK_TYPE_CGROUP:
466 		jsonw_lluint_field(json_wtr, "cgroup_id",
467 				   info->cgroup.cgroup_id);
468 		show_link_attach_type_json(info->cgroup.attach_type, json_wtr);
469 		break;
470 	case BPF_LINK_TYPE_ITER:
471 		show_iter_json(info, json_wtr);
472 		break;
473 	case BPF_LINK_TYPE_NETNS:
474 		jsonw_uint_field(json_wtr, "netns_ino",
475 				 info->netns.netns_ino);
476 		show_link_attach_type_json(info->netns.attach_type, json_wtr);
477 		break;
478 	case BPF_LINK_TYPE_NETFILTER:
479 		netfilter_dump_json(info, json_wtr);
480 		break;
481 	case BPF_LINK_TYPE_TCX:
482 		show_link_ifindex_json(info->tcx.ifindex, json_wtr);
483 		show_link_attach_type_json(info->tcx.attach_type, json_wtr);
484 		break;
485 	case BPF_LINK_TYPE_NETKIT:
486 		show_link_ifindex_json(info->netkit.ifindex, json_wtr);
487 		show_link_attach_type_json(info->netkit.attach_type, json_wtr);
488 		break;
489 	case BPF_LINK_TYPE_XDP:
490 		show_link_ifindex_json(info->xdp.ifindex, json_wtr);
491 		break;
492 	case BPF_LINK_TYPE_STRUCT_OPS:
493 		jsonw_uint_field(json_wtr, "map_id",
494 				 info->struct_ops.map_id);
495 		break;
496 	case BPF_LINK_TYPE_KPROBE_MULTI:
497 		show_kprobe_multi_json(info, json_wtr);
498 		break;
499 	case BPF_LINK_TYPE_UPROBE_MULTI:
500 		show_uprobe_multi_json(info, json_wtr);
501 		break;
502 	case BPF_LINK_TYPE_PERF_EVENT:
503 		switch (info->perf_event.type) {
504 		case BPF_PERF_EVENT_EVENT:
505 			show_perf_event_event_json(info, json_wtr);
506 			break;
507 		case BPF_PERF_EVENT_TRACEPOINT:
508 			show_perf_event_tracepoint_json(info, json_wtr);
509 			break;
510 		case BPF_PERF_EVENT_KPROBE:
511 		case BPF_PERF_EVENT_KRETPROBE:
512 			show_perf_event_kprobe_json(info, json_wtr);
513 			break;
514 		case BPF_PERF_EVENT_UPROBE:
515 		case BPF_PERF_EVENT_URETPROBE:
516 			show_perf_event_uprobe_json(info, json_wtr);
517 			break;
518 		default:
519 			break;
520 		}
521 		break;
522 	default:
523 		break;
524 	}
525 
526 	if (!hashmap__empty(link_table)) {
527 		struct hashmap_entry *entry;
528 
529 		jsonw_name(json_wtr, "pinned");
530 		jsonw_start_array(json_wtr);
531 		hashmap__for_each_key_entry(link_table, entry, info->id)
532 			jsonw_string(json_wtr, entry->pvalue);
533 		jsonw_end_array(json_wtr);
534 	}
535 
536 	emit_obj_refs_json(refs_table, info->id, json_wtr);
537 
538 	jsonw_end_object(json_wtr);
539 
540 	return 0;
541 }
542 
543 static void show_link_header_plain(struct bpf_link_info *info)
544 {
545 	const char *link_type_str;
546 
547 	printf("%u: ", info->id);
548 	link_type_str = libbpf_bpf_link_type_str(info->type);
549 	if (link_type_str)
550 		printf("%s  ", link_type_str);
551 	else
552 		printf("type %u  ", info->type);
553 
554 	if (info->type == BPF_LINK_TYPE_STRUCT_OPS)
555 		printf("map %u  ", info->struct_ops.map_id);
556 	else
557 		printf("prog %u  ", info->prog_id);
558 }
559 
560 static void show_link_attach_type_plain(__u32 attach_type)
561 {
562 	const char *attach_type_str;
563 
564 	attach_type_str = libbpf_bpf_attach_type_str(attach_type);
565 	if (attach_type_str)
566 		printf("attach_type %s  ", attach_type_str);
567 	else
568 		printf("attach_type %u  ", attach_type);
569 }
570 
571 static void show_link_ifindex_plain(__u32 ifindex)
572 {
573 	char devname[IF_NAMESIZE * 2] = "(unknown)";
574 	char tmpname[IF_NAMESIZE];
575 	char *ret = NULL;
576 
577 	if (ifindex)
578 		ret = if_indextoname(ifindex, tmpname);
579 	else
580 		snprintf(devname, sizeof(devname), "(detached)");
581 	if (ret)
582 		snprintf(devname, sizeof(devname), "%s(%d)",
583 			 tmpname, ifindex);
584 	printf("ifindex %s  ", devname);
585 }
586 
587 static void show_iter_plain(struct bpf_link_info *info)
588 {
589 	const char *target_name = u64_to_ptr(info->iter.target_name);
590 
591 	printf("target_name %s  ", target_name);
592 
593 	if (is_iter_map_target(target_name))
594 		printf("map_id %u  ", info->iter.map.map_id);
595 	else if (is_iter_task_target(target_name)) {
596 		if (info->iter.task.tid)
597 			printf("tid %u ", info->iter.task.tid);
598 		else if (info->iter.task.pid)
599 			printf("pid %u ", info->iter.task.pid);
600 	}
601 
602 	if (is_iter_cgroup_target(target_name)) {
603 		printf("cgroup_id %llu  ", info->iter.cgroup.cgroup_id);
604 		printf("order %s  ",
605 		       cgroup_order_string(info->iter.cgroup.order));
606 	}
607 }
608 
609 static const char * const pf2name[] = {
610 	[NFPROTO_INET] = "inet",
611 	[NFPROTO_IPV4] = "ip",
612 	[NFPROTO_ARP] = "arp",
613 	[NFPROTO_NETDEV] = "netdev",
614 	[NFPROTO_BRIDGE] = "bridge",
615 	[NFPROTO_IPV6] = "ip6",
616 };
617 
618 static const char * const inethook2name[] = {
619 	[NF_INET_PRE_ROUTING] = "prerouting",
620 	[NF_INET_LOCAL_IN] = "input",
621 	[NF_INET_FORWARD] = "forward",
622 	[NF_INET_LOCAL_OUT] = "output",
623 	[NF_INET_POST_ROUTING] = "postrouting",
624 };
625 
626 static const char * const arphook2name[] = {
627 	[NF_ARP_IN] = "input",
628 	[NF_ARP_OUT] = "output",
629 };
630 
631 void netfilter_dump_plain(const struct bpf_link_info *info)
632 {
633 	const char *hookname = NULL, *pfname = NULL;
634 	unsigned int hook = info->netfilter.hooknum;
635 	unsigned int pf = info->netfilter.pf;
636 
637 	if (pf < ARRAY_SIZE(pf2name))
638 		pfname = pf2name[pf];
639 
640 	switch (pf) {
641 	case NFPROTO_BRIDGE: /* bridge shares numbers with enum nf_inet_hooks */
642 	case NFPROTO_IPV4:
643 	case NFPROTO_IPV6:
644 	case NFPROTO_INET:
645 		if (hook < ARRAY_SIZE(inethook2name))
646 			hookname = inethook2name[hook];
647 		break;
648 	case NFPROTO_ARP:
649 		if (hook < ARRAY_SIZE(arphook2name))
650 			hookname = arphook2name[hook];
651 	default:
652 		break;
653 	}
654 
655 	if (pfname)
656 		printf("\n\t%s", pfname);
657 	else
658 		printf("\n\tpf: %d", pf);
659 
660 	if (hookname)
661 		printf(" %s", hookname);
662 	else
663 		printf(", hook %u,", hook);
664 
665 	printf(" prio %d", info->netfilter.priority);
666 
667 	if (info->netfilter.flags)
668 		printf(" flags 0x%x", info->netfilter.flags);
669 }
670 
671 static void show_kprobe_multi_plain(struct bpf_link_info *info)
672 {
673 	__u32 i, j = 0;
674 	__u64 *addrs;
675 
676 	if (!info->kprobe_multi.count)
677 		return;
678 
679 	if (info->kprobe_multi.flags & BPF_F_KPROBE_MULTI_RETURN)
680 		printf("\n\tkretprobe.multi  ");
681 	else
682 		printf("\n\tkprobe.multi  ");
683 	printf("func_cnt %u  ", info->kprobe_multi.count);
684 	if (info->kprobe_multi.missed)
685 		printf("missed %llu  ", info->kprobe_multi.missed);
686 	addrs = (__u64 *)u64_to_ptr(info->kprobe_multi.addrs);
687 	qsort(addrs, info->kprobe_multi.count, sizeof(__u64), cmp_u64);
688 
689 	/* Load it once for all. */
690 	if (!dd.sym_count)
691 		kernel_syms_load(&dd);
692 	if (!dd.sym_count)
693 		return;
694 
695 	printf("\n\t%-16s %s", "addr", "func [module]");
696 	for (i = 0; i < dd.sym_count; i++) {
697 		if (dd.sym_mapping[i].address != addrs[j])
698 			continue;
699 		printf("\n\t%016lx %s",
700 		       dd.sym_mapping[i].address, dd.sym_mapping[i].name);
701 		if (dd.sym_mapping[i].module[0] != '\0')
702 			printf(" [%s]  ", dd.sym_mapping[i].module);
703 		else
704 			printf("  ");
705 
706 		if (j++ == info->kprobe_multi.count)
707 			break;
708 	}
709 }
710 
711 static void show_uprobe_multi_plain(struct bpf_link_info *info)
712 {
713 	__u32 i;
714 
715 	if (!info->uprobe_multi.count)
716 		return;
717 
718 	if (info->uprobe_multi.flags & BPF_F_UPROBE_MULTI_RETURN)
719 		printf("\n\turetprobe.multi  ");
720 	else
721 		printf("\n\tuprobe.multi  ");
722 
723 	printf("path %s  ", (char *) u64_to_ptr(info->uprobe_multi.path));
724 	printf("func_cnt %u  ", info->uprobe_multi.count);
725 
726 	if (info->uprobe_multi.pid)
727 		printf("pid %d  ", info->uprobe_multi.pid);
728 
729 	printf("\n\t%-16s   %-16s   %-16s", "offset", "ref_ctr_offset", "cookies");
730 	for (i = 0; i < info->uprobe_multi.count; i++) {
731 		printf("\n\t0x%-16llx 0x%-16llx 0x%-16llx",
732 			u64_to_arr(info->uprobe_multi.offsets)[i],
733 			u64_to_arr(info->uprobe_multi.ref_ctr_offsets)[i],
734 			u64_to_arr(info->uprobe_multi.cookies)[i]);
735 	}
736 }
737 
738 static void show_perf_event_kprobe_plain(struct bpf_link_info *info)
739 {
740 	const char *buf;
741 
742 	buf = u64_to_ptr(info->perf_event.kprobe.func_name);
743 	if (buf[0] == '\0' && !info->perf_event.kprobe.addr)
744 		return;
745 
746 	if (info->perf_event.type == BPF_PERF_EVENT_KRETPROBE)
747 		printf("\n\tkretprobe ");
748 	else
749 		printf("\n\tkprobe ");
750 	if (info->perf_event.kprobe.addr)
751 		printf("%llx ", info->perf_event.kprobe.addr);
752 	printf("%s", buf);
753 	if (info->perf_event.kprobe.offset)
754 		printf("+%#x", info->perf_event.kprobe.offset);
755 	if (info->perf_event.kprobe.missed)
756 		printf("  missed %llu", info->perf_event.kprobe.missed);
757 	printf("  ");
758 }
759 
760 static void show_perf_event_uprobe_plain(struct bpf_link_info *info)
761 {
762 	const char *buf;
763 
764 	buf = u64_to_ptr(info->perf_event.uprobe.file_name);
765 	if (buf[0] == '\0')
766 		return;
767 
768 	if (info->perf_event.type == BPF_PERF_EVENT_URETPROBE)
769 		printf("\n\turetprobe ");
770 	else
771 		printf("\n\tuprobe ");
772 	printf("%s+%#x  ", buf, info->perf_event.uprobe.offset);
773 }
774 
775 static void show_perf_event_tracepoint_plain(struct bpf_link_info *info)
776 {
777 	const char *buf;
778 
779 	buf = u64_to_ptr(info->perf_event.tracepoint.tp_name);
780 	if (buf[0] == '\0')
781 		return;
782 
783 	printf("\n\ttracepoint %s  ", buf);
784 }
785 
786 static void show_perf_event_event_plain(struct bpf_link_info *info)
787 {
788 	__u64 config = info->perf_event.event.config;
789 	__u32 type = info->perf_event.event.type;
790 	const char *perf_type, *perf_config;
791 
792 	printf("\n\tevent ");
793 	perf_type = perf_event_name(perf_type_name, type);
794 	if (perf_type)
795 		printf("%s:", perf_type);
796 	else
797 		printf("%u :", type);
798 
799 	perf_config = perf_config_str(type, config);
800 	if (perf_config)
801 		printf("%s  ", perf_config);
802 	else
803 		printf("%llu  ", config);
804 
805 	if (type == PERF_TYPE_HW_CACHE && perf_config)
806 		free((void *)perf_config);
807 }
808 
809 static int show_link_close_plain(int fd, struct bpf_link_info *info)
810 {
811 	struct bpf_prog_info prog_info;
812 	const char *prog_type_str;
813 	int err;
814 
815 	show_link_header_plain(info);
816 
817 	switch (info->type) {
818 	case BPF_LINK_TYPE_RAW_TRACEPOINT:
819 		printf("\n\ttp '%s'  ",
820 		       (const char *)u64_to_ptr(info->raw_tracepoint.tp_name));
821 		break;
822 	case BPF_LINK_TYPE_TRACING:
823 		err = get_prog_info(info->prog_id, &prog_info);
824 		if (err)
825 			return err;
826 
827 		prog_type_str = libbpf_bpf_prog_type_str(prog_info.type);
828 		/* libbpf will return NULL for variants unknown to it. */
829 		if (prog_type_str)
830 			printf("\n\tprog_type %s  ", prog_type_str);
831 		else
832 			printf("\n\tprog_type %u  ", prog_info.type);
833 
834 		show_link_attach_type_plain(info->tracing.attach_type);
835 		if (info->tracing.target_obj_id || info->tracing.target_btf_id)
836 			printf("\n\ttarget_obj_id %u  target_btf_id %u  ",
837 			       info->tracing.target_obj_id,
838 			       info->tracing.target_btf_id);
839 		break;
840 	case BPF_LINK_TYPE_CGROUP:
841 		printf("\n\tcgroup_id %zu  ", (size_t)info->cgroup.cgroup_id);
842 		show_link_attach_type_plain(info->cgroup.attach_type);
843 		break;
844 	case BPF_LINK_TYPE_ITER:
845 		show_iter_plain(info);
846 		break;
847 	case BPF_LINK_TYPE_NETNS:
848 		printf("\n\tnetns_ino %u  ", info->netns.netns_ino);
849 		show_link_attach_type_plain(info->netns.attach_type);
850 		break;
851 	case BPF_LINK_TYPE_NETFILTER:
852 		netfilter_dump_plain(info);
853 		break;
854 	case BPF_LINK_TYPE_TCX:
855 		printf("\n\t");
856 		show_link_ifindex_plain(info->tcx.ifindex);
857 		show_link_attach_type_plain(info->tcx.attach_type);
858 		break;
859 	case BPF_LINK_TYPE_NETKIT:
860 		printf("\n\t");
861 		show_link_ifindex_plain(info->netkit.ifindex);
862 		show_link_attach_type_plain(info->netkit.attach_type);
863 		break;
864 	case BPF_LINK_TYPE_XDP:
865 		printf("\n\t");
866 		show_link_ifindex_plain(info->xdp.ifindex);
867 		break;
868 	case BPF_LINK_TYPE_KPROBE_MULTI:
869 		show_kprobe_multi_plain(info);
870 		break;
871 	case BPF_LINK_TYPE_UPROBE_MULTI:
872 		show_uprobe_multi_plain(info);
873 		break;
874 	case BPF_LINK_TYPE_PERF_EVENT:
875 		switch (info->perf_event.type) {
876 		case BPF_PERF_EVENT_EVENT:
877 			show_perf_event_event_plain(info);
878 			break;
879 		case BPF_PERF_EVENT_TRACEPOINT:
880 			show_perf_event_tracepoint_plain(info);
881 			break;
882 		case BPF_PERF_EVENT_KPROBE:
883 		case BPF_PERF_EVENT_KRETPROBE:
884 			show_perf_event_kprobe_plain(info);
885 			break;
886 		case BPF_PERF_EVENT_UPROBE:
887 		case BPF_PERF_EVENT_URETPROBE:
888 			show_perf_event_uprobe_plain(info);
889 			break;
890 		default:
891 			break;
892 		}
893 		break;
894 	default:
895 		break;
896 	}
897 
898 	if (!hashmap__empty(link_table)) {
899 		struct hashmap_entry *entry;
900 
901 		hashmap__for_each_key_entry(link_table, entry, info->id)
902 			printf("\n\tpinned %s", (char *)entry->pvalue);
903 	}
904 	emit_obj_refs_plain(refs_table, info->id, "\n\tpids ");
905 
906 	printf("\n");
907 
908 	return 0;
909 }
910 
911 static int do_show_link(int fd)
912 {
913 	__u64 *ref_ctr_offsets = NULL, *offsets = NULL, *cookies = NULL;
914 	struct bpf_link_info info;
915 	__u32 len = sizeof(info);
916 	char path_buf[PATH_MAX];
917 	__u64 *addrs = NULL;
918 	char buf[PATH_MAX];
919 	int count;
920 	int err;
921 
922 	memset(&info, 0, sizeof(info));
923 	buf[0] = '\0';
924 again:
925 	err = bpf_link_get_info_by_fd(fd, &info, &len);
926 	if (err) {
927 		p_err("can't get link info: %s",
928 		      strerror(errno));
929 		close(fd);
930 		return err;
931 	}
932 	if (info.type == BPF_LINK_TYPE_RAW_TRACEPOINT &&
933 	    !info.raw_tracepoint.tp_name) {
934 		info.raw_tracepoint.tp_name = ptr_to_u64(&buf);
935 		info.raw_tracepoint.tp_name_len = sizeof(buf);
936 		goto again;
937 	}
938 	if (info.type == BPF_LINK_TYPE_ITER &&
939 	    !info.iter.target_name) {
940 		info.iter.target_name = ptr_to_u64(&buf);
941 		info.iter.target_name_len = sizeof(buf);
942 		goto again;
943 	}
944 	if (info.type == BPF_LINK_TYPE_KPROBE_MULTI &&
945 	    !info.kprobe_multi.addrs) {
946 		count = info.kprobe_multi.count;
947 		if (count) {
948 			addrs = calloc(count, sizeof(__u64));
949 			if (!addrs) {
950 				p_err("mem alloc failed");
951 				close(fd);
952 				return -ENOMEM;
953 			}
954 			info.kprobe_multi.addrs = ptr_to_u64(addrs);
955 			goto again;
956 		}
957 	}
958 	if (info.type == BPF_LINK_TYPE_UPROBE_MULTI &&
959 	    !info.uprobe_multi.offsets) {
960 		count = info.uprobe_multi.count;
961 		if (count) {
962 			offsets = calloc(count, sizeof(__u64));
963 			if (!offsets) {
964 				p_err("mem alloc failed");
965 				close(fd);
966 				return -ENOMEM;
967 			}
968 			info.uprobe_multi.offsets = ptr_to_u64(offsets);
969 			ref_ctr_offsets = calloc(count, sizeof(__u64));
970 			if (!ref_ctr_offsets) {
971 				p_err("mem alloc failed");
972 				free(offsets);
973 				close(fd);
974 				return -ENOMEM;
975 			}
976 			info.uprobe_multi.ref_ctr_offsets = ptr_to_u64(ref_ctr_offsets);
977 			cookies = calloc(count, sizeof(__u64));
978 			if (!cookies) {
979 				p_err("mem alloc failed");
980 				free(cookies);
981 				free(offsets);
982 				close(fd);
983 				return -ENOMEM;
984 			}
985 			info.uprobe_multi.cookies = ptr_to_u64(cookies);
986 			info.uprobe_multi.path = ptr_to_u64(path_buf);
987 			info.uprobe_multi.path_size = sizeof(path_buf);
988 			goto again;
989 		}
990 	}
991 	if (info.type == BPF_LINK_TYPE_PERF_EVENT) {
992 		switch (info.perf_event.type) {
993 		case BPF_PERF_EVENT_TRACEPOINT:
994 			if (!info.perf_event.tracepoint.tp_name) {
995 				info.perf_event.tracepoint.tp_name = ptr_to_u64(&buf);
996 				info.perf_event.tracepoint.name_len = sizeof(buf);
997 				goto again;
998 			}
999 			break;
1000 		case BPF_PERF_EVENT_KPROBE:
1001 		case BPF_PERF_EVENT_KRETPROBE:
1002 			if (!info.perf_event.kprobe.func_name) {
1003 				info.perf_event.kprobe.func_name = ptr_to_u64(&buf);
1004 				info.perf_event.kprobe.name_len = sizeof(buf);
1005 				goto again;
1006 			}
1007 			break;
1008 		case BPF_PERF_EVENT_UPROBE:
1009 		case BPF_PERF_EVENT_URETPROBE:
1010 			if (!info.perf_event.uprobe.file_name) {
1011 				info.perf_event.uprobe.file_name = ptr_to_u64(&buf);
1012 				info.perf_event.uprobe.name_len = sizeof(buf);
1013 				goto again;
1014 			}
1015 			break;
1016 		default:
1017 			break;
1018 		}
1019 	}
1020 
1021 	if (json_output)
1022 		show_link_close_json(fd, &info);
1023 	else
1024 		show_link_close_plain(fd, &info);
1025 
1026 	free(ref_ctr_offsets);
1027 	free(cookies);
1028 	free(offsets);
1029 	free(addrs);
1030 	close(fd);
1031 	return 0;
1032 }
1033 
1034 static int do_show(int argc, char **argv)
1035 {
1036 	__u32 id = 0;
1037 	int err, fd;
1038 
1039 	if (show_pinned) {
1040 		link_table = hashmap__new(hash_fn_for_key_as_id,
1041 					  equal_fn_for_key_as_id, NULL);
1042 		if (IS_ERR(link_table)) {
1043 			p_err("failed to create hashmap for pinned paths");
1044 			return -1;
1045 		}
1046 		build_pinned_obj_table(link_table, BPF_OBJ_LINK);
1047 	}
1048 	build_obj_refs_table(&refs_table, BPF_OBJ_LINK);
1049 
1050 	if (argc == 2) {
1051 		fd = link_parse_fd(&argc, &argv);
1052 		if (fd < 0)
1053 			return fd;
1054 		do_show_link(fd);
1055 		goto out;
1056 	}
1057 
1058 	if (argc)
1059 		return BAD_ARG();
1060 
1061 	if (json_output)
1062 		jsonw_start_array(json_wtr);
1063 	while (true) {
1064 		err = bpf_link_get_next_id(id, &id);
1065 		if (err) {
1066 			if (errno == ENOENT)
1067 				break;
1068 			p_err("can't get next link: %s%s", strerror(errno),
1069 			      errno == EINVAL ? " -- kernel too old?" : "");
1070 			break;
1071 		}
1072 
1073 		fd = bpf_link_get_fd_by_id(id);
1074 		if (fd < 0) {
1075 			if (errno == ENOENT)
1076 				continue;
1077 			p_err("can't get link by id (%u): %s",
1078 			      id, strerror(errno));
1079 			break;
1080 		}
1081 
1082 		err = do_show_link(fd);
1083 		if (err)
1084 			break;
1085 	}
1086 	if (json_output)
1087 		jsonw_end_array(json_wtr);
1088 
1089 	delete_obj_refs_table(refs_table);
1090 
1091 	if (show_pinned)
1092 		delete_pinned_obj_table(link_table);
1093 
1094 out:
1095 	if (dd.sym_count)
1096 		kernel_syms_destroy(&dd);
1097 	return errno == ENOENT ? 0 : -1;
1098 }
1099 
1100 static int do_pin(int argc, char **argv)
1101 {
1102 	int err;
1103 
1104 	err = do_pin_any(argc, argv, link_parse_fd);
1105 	if (!err && json_output)
1106 		jsonw_null(json_wtr);
1107 	return err;
1108 }
1109 
1110 static int do_detach(int argc, char **argv)
1111 {
1112 	int err, fd;
1113 
1114 	if (argc != 2) {
1115 		p_err("link specifier is invalid or missing\n");
1116 		return 1;
1117 	}
1118 
1119 	fd = link_parse_fd(&argc, &argv);
1120 	if (fd < 0)
1121 		return 1;
1122 
1123 	err = bpf_link_detach(fd);
1124 	if (err)
1125 		err = -errno;
1126 	close(fd);
1127 	if (err) {
1128 		p_err("failed link detach: %s", strerror(-err));
1129 		return 1;
1130 	}
1131 
1132 	if (json_output)
1133 		jsonw_null(json_wtr);
1134 
1135 	return 0;
1136 }
1137 
1138 static int do_help(int argc, char **argv)
1139 {
1140 	if (json_output) {
1141 		jsonw_null(json_wtr);
1142 		return 0;
1143 	}
1144 
1145 	fprintf(stderr,
1146 		"Usage: %1$s %2$s { show | list }   [LINK]\n"
1147 		"       %1$s %2$s pin        LINK  FILE\n"
1148 		"       %1$s %2$s detach     LINK\n"
1149 		"       %1$s %2$s help\n"
1150 		"\n"
1151 		"       " HELP_SPEC_LINK "\n"
1152 		"       " HELP_SPEC_OPTIONS " |\n"
1153 		"                    {-f|--bpffs} | {-n|--nomount} }\n"
1154 		"",
1155 		bin_name, argv[-2]);
1156 
1157 	return 0;
1158 }
1159 
1160 static const struct cmd cmds[] = {
1161 	{ "show",	do_show },
1162 	{ "list",	do_show },
1163 	{ "help",	do_help },
1164 	{ "pin",	do_pin },
1165 	{ "detach",	do_detach },
1166 	{ 0 }
1167 };
1168 
1169 int do_link(int argc, char **argv)
1170 {
1171 	return cmd_select(cmds, argc, argv, do_help);
1172 }
1173