xref: /openbmc/linux/tools/bpf/bpftool/link.c (revision 61f4d204)
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) >= 0 && (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 bool is_iter_map_target(const char *target_name)
154 {
155 	return strcmp(target_name, "bpf_map_elem") == 0 ||
156 	       strcmp(target_name, "bpf_sk_storage_map") == 0;
157 }
158 
159 static bool is_iter_cgroup_target(const char *target_name)
160 {
161 	return strcmp(target_name, "cgroup") == 0;
162 }
163 
164 static const char *cgroup_order_string(__u32 order)
165 {
166 	switch (order) {
167 	case BPF_CGROUP_ITER_ORDER_UNSPEC:
168 		return "order_unspec";
169 	case BPF_CGROUP_ITER_SELF_ONLY:
170 		return "self_only";
171 	case BPF_CGROUP_ITER_DESCENDANTS_PRE:
172 		return "descendants_pre";
173 	case BPF_CGROUP_ITER_DESCENDANTS_POST:
174 		return "descendants_post";
175 	case BPF_CGROUP_ITER_ANCESTORS_UP:
176 		return "ancestors_up";
177 	default: /* won't happen */
178 		return "unknown";
179 	}
180 }
181 
182 static bool is_iter_task_target(const char *target_name)
183 {
184 	return strcmp(target_name, "task") == 0 ||
185 		strcmp(target_name, "task_file") == 0 ||
186 		strcmp(target_name, "task_vma") == 0;
187 }
188 
189 static void show_iter_json(struct bpf_link_info *info, json_writer_t *wtr)
190 {
191 	const char *target_name = u64_to_ptr(info->iter.target_name);
192 
193 	jsonw_string_field(wtr, "target_name", target_name);
194 
195 	if (is_iter_map_target(target_name))
196 		jsonw_uint_field(wtr, "map_id", info->iter.map.map_id);
197 	else if (is_iter_task_target(target_name)) {
198 		if (info->iter.task.tid)
199 			jsonw_uint_field(wtr, "tid", info->iter.task.tid);
200 		else if (info->iter.task.pid)
201 			jsonw_uint_field(wtr, "pid", info->iter.task.pid);
202 	}
203 
204 	if (is_iter_cgroup_target(target_name)) {
205 		jsonw_lluint_field(wtr, "cgroup_id", info->iter.cgroup.cgroup_id);
206 		jsonw_string_field(wtr, "order",
207 				   cgroup_order_string(info->iter.cgroup.order));
208 	}
209 }
210 
211 void netfilter_dump_json(const struct bpf_link_info *info, json_writer_t *wtr)
212 {
213 	jsonw_uint_field(json_wtr, "pf",
214 			 info->netfilter.pf);
215 	jsonw_uint_field(json_wtr, "hook",
216 			 info->netfilter.hooknum);
217 	jsonw_int_field(json_wtr, "prio",
218 			 info->netfilter.priority);
219 	jsonw_uint_field(json_wtr, "flags",
220 			 info->netfilter.flags);
221 }
222 
223 static int get_prog_info(int prog_id, struct bpf_prog_info *info)
224 {
225 	__u32 len = sizeof(*info);
226 	int err, prog_fd;
227 
228 	prog_fd = bpf_prog_get_fd_by_id(prog_id);
229 	if (prog_fd < 0)
230 		return prog_fd;
231 
232 	memset(info, 0, sizeof(*info));
233 	err = bpf_prog_get_info_by_fd(prog_fd, info, &len);
234 	if (err)
235 		p_err("can't get prog info: %s", strerror(errno));
236 	close(prog_fd);
237 	return err;
238 }
239 
240 static int cmp_u64(const void *A, const void *B)
241 {
242 	const __u64 *a = A, *b = B;
243 
244 	return *a - *b;
245 }
246 
247 static void
248 show_kprobe_multi_json(struct bpf_link_info *info, json_writer_t *wtr)
249 {
250 	__u32 i, j = 0;
251 	__u64 *addrs;
252 
253 	jsonw_bool_field(json_wtr, "retprobe",
254 			 info->kprobe_multi.flags & BPF_F_KPROBE_MULTI_RETURN);
255 	jsonw_uint_field(json_wtr, "func_cnt", info->kprobe_multi.count);
256 	jsonw_name(json_wtr, "funcs");
257 	jsonw_start_array(json_wtr);
258 	addrs = u64_to_ptr(info->kprobe_multi.addrs);
259 	qsort(addrs, info->kprobe_multi.count, sizeof(addrs[0]), cmp_u64);
260 
261 	/* Load it once for all. */
262 	if (!dd.sym_count)
263 		kernel_syms_load(&dd);
264 	for (i = 0; i < dd.sym_count; i++) {
265 		if (dd.sym_mapping[i].address != addrs[j])
266 			continue;
267 		jsonw_start_object(json_wtr);
268 		jsonw_uint_field(json_wtr, "addr", dd.sym_mapping[i].address);
269 		jsonw_string_field(json_wtr, "func", dd.sym_mapping[i].name);
270 		/* Print null if it is vmlinux */
271 		if (dd.sym_mapping[i].module[0] == '\0') {
272 			jsonw_name(json_wtr, "module");
273 			jsonw_null(json_wtr);
274 		} else {
275 			jsonw_string_field(json_wtr, "module", dd.sym_mapping[i].module);
276 		}
277 		jsonw_end_object(json_wtr);
278 		if (j++ == info->kprobe_multi.count)
279 			break;
280 	}
281 	jsonw_end_array(json_wtr);
282 }
283 
284 static void
285 show_perf_event_kprobe_json(struct bpf_link_info *info, json_writer_t *wtr)
286 {
287 	jsonw_bool_field(wtr, "retprobe", info->perf_event.type == BPF_PERF_EVENT_KRETPROBE);
288 	jsonw_uint_field(wtr, "addr", info->perf_event.kprobe.addr);
289 	jsonw_string_field(wtr, "func",
290 			   u64_to_ptr(info->perf_event.kprobe.func_name));
291 	jsonw_uint_field(wtr, "offset", info->perf_event.kprobe.offset);
292 }
293 
294 static void
295 show_perf_event_uprobe_json(struct bpf_link_info *info, json_writer_t *wtr)
296 {
297 	jsonw_bool_field(wtr, "retprobe", info->perf_event.type == BPF_PERF_EVENT_URETPROBE);
298 	jsonw_string_field(wtr, "file",
299 			   u64_to_ptr(info->perf_event.uprobe.file_name));
300 	jsonw_uint_field(wtr, "offset", info->perf_event.uprobe.offset);
301 }
302 
303 static void
304 show_perf_event_tracepoint_json(struct bpf_link_info *info, json_writer_t *wtr)
305 {
306 	jsonw_string_field(wtr, "tracepoint",
307 			   u64_to_ptr(info->perf_event.tracepoint.tp_name));
308 }
309 
310 static char *perf_config_hw_cache_str(__u64 config)
311 {
312 	const char *hw_cache, *result, *op;
313 	char *str = malloc(PERF_HW_CACHE_LEN);
314 
315 	if (!str) {
316 		p_err("mem alloc failed");
317 		return NULL;
318 	}
319 
320 	hw_cache = perf_event_name(evsel__hw_cache, config & 0xff);
321 	if (hw_cache)
322 		snprintf(str, PERF_HW_CACHE_LEN, "%s-", hw_cache);
323 	else
324 		snprintf(str, PERF_HW_CACHE_LEN, "%lld-", config & 0xff);
325 
326 	op = perf_event_name(evsel__hw_cache_op, (config >> 8) & 0xff);
327 	if (op)
328 		snprintf(str + strlen(str), PERF_HW_CACHE_LEN - strlen(str),
329 			 "%s-", op);
330 	else
331 		snprintf(str + strlen(str), PERF_HW_CACHE_LEN - strlen(str),
332 			 "%lld-", (config >> 8) & 0xff);
333 
334 	result = perf_event_name(evsel__hw_cache_result, config >> 16);
335 	if (result)
336 		snprintf(str + strlen(str), PERF_HW_CACHE_LEN - strlen(str),
337 			 "%s", result);
338 	else
339 		snprintf(str + strlen(str), PERF_HW_CACHE_LEN - strlen(str),
340 			 "%lld", config >> 16);
341 	return str;
342 }
343 
344 static const char *perf_config_str(__u32 type, __u64 config)
345 {
346 	const char *perf_config;
347 
348 	switch (type) {
349 	case PERF_TYPE_HARDWARE:
350 		perf_config = perf_event_name(event_symbols_hw, config);
351 		break;
352 	case PERF_TYPE_SOFTWARE:
353 		perf_config = perf_event_name(event_symbols_sw, config);
354 		break;
355 	case PERF_TYPE_HW_CACHE:
356 		perf_config = perf_config_hw_cache_str(config);
357 		break;
358 	default:
359 		perf_config = NULL;
360 		break;
361 	}
362 	return perf_config;
363 }
364 
365 static void
366 show_perf_event_event_json(struct bpf_link_info *info, json_writer_t *wtr)
367 {
368 	__u64 config = info->perf_event.event.config;
369 	__u32 type = info->perf_event.event.type;
370 	const char *perf_type, *perf_config;
371 
372 	perf_type = perf_event_name(perf_type_name, type);
373 	if (perf_type)
374 		jsonw_string_field(wtr, "event_type", perf_type);
375 	else
376 		jsonw_uint_field(wtr, "event_type", type);
377 
378 	perf_config = perf_config_str(type, config);
379 	if (perf_config)
380 		jsonw_string_field(wtr, "event_config", perf_config);
381 	else
382 		jsonw_uint_field(wtr, "event_config", config);
383 
384 	if (type == PERF_TYPE_HW_CACHE && perf_config)
385 		free((void *)perf_config);
386 }
387 
388 static int show_link_close_json(int fd, struct bpf_link_info *info)
389 {
390 	struct bpf_prog_info prog_info;
391 	const char *prog_type_str;
392 	int err;
393 
394 	jsonw_start_object(json_wtr);
395 
396 	show_link_header_json(info, json_wtr);
397 
398 	switch (info->type) {
399 	case BPF_LINK_TYPE_RAW_TRACEPOINT:
400 		jsonw_string_field(json_wtr, "tp_name",
401 				   u64_to_ptr(info->raw_tracepoint.tp_name));
402 		break;
403 	case BPF_LINK_TYPE_TRACING:
404 		err = get_prog_info(info->prog_id, &prog_info);
405 		if (err)
406 			return err;
407 
408 		prog_type_str = libbpf_bpf_prog_type_str(prog_info.type);
409 		/* libbpf will return NULL for variants unknown to it. */
410 		if (prog_type_str)
411 			jsonw_string_field(json_wtr, "prog_type", prog_type_str);
412 		else
413 			jsonw_uint_field(json_wtr, "prog_type", prog_info.type);
414 
415 		show_link_attach_type_json(info->tracing.attach_type,
416 					   json_wtr);
417 		jsonw_uint_field(json_wtr, "target_obj_id", info->tracing.target_obj_id);
418 		jsonw_uint_field(json_wtr, "target_btf_id", info->tracing.target_btf_id);
419 		break;
420 	case BPF_LINK_TYPE_CGROUP:
421 		jsonw_lluint_field(json_wtr, "cgroup_id",
422 				   info->cgroup.cgroup_id);
423 		show_link_attach_type_json(info->cgroup.attach_type, json_wtr);
424 		break;
425 	case BPF_LINK_TYPE_ITER:
426 		show_iter_json(info, json_wtr);
427 		break;
428 	case BPF_LINK_TYPE_NETNS:
429 		jsonw_uint_field(json_wtr, "netns_ino",
430 				 info->netns.netns_ino);
431 		show_link_attach_type_json(info->netns.attach_type, json_wtr);
432 		break;
433 	case BPF_LINK_TYPE_NETFILTER:
434 		netfilter_dump_json(info, json_wtr);
435 		break;
436 	case BPF_LINK_TYPE_STRUCT_OPS:
437 		jsonw_uint_field(json_wtr, "map_id",
438 				 info->struct_ops.map_id);
439 		break;
440 	case BPF_LINK_TYPE_KPROBE_MULTI:
441 		show_kprobe_multi_json(info, json_wtr);
442 		break;
443 	case BPF_LINK_TYPE_PERF_EVENT:
444 		switch (info->perf_event.type) {
445 		case BPF_PERF_EVENT_EVENT:
446 			show_perf_event_event_json(info, json_wtr);
447 			break;
448 		case BPF_PERF_EVENT_TRACEPOINT:
449 			show_perf_event_tracepoint_json(info, json_wtr);
450 			break;
451 		case BPF_PERF_EVENT_KPROBE:
452 		case BPF_PERF_EVENT_KRETPROBE:
453 			show_perf_event_kprobe_json(info, json_wtr);
454 			break;
455 		case BPF_PERF_EVENT_UPROBE:
456 		case BPF_PERF_EVENT_URETPROBE:
457 			show_perf_event_uprobe_json(info, json_wtr);
458 			break;
459 		default:
460 			break;
461 		}
462 		break;
463 	default:
464 		break;
465 	}
466 
467 	if (!hashmap__empty(link_table)) {
468 		struct hashmap_entry *entry;
469 
470 		jsonw_name(json_wtr, "pinned");
471 		jsonw_start_array(json_wtr);
472 		hashmap__for_each_key_entry(link_table, entry, info->id)
473 			jsonw_string(json_wtr, entry->pvalue);
474 		jsonw_end_array(json_wtr);
475 	}
476 
477 	emit_obj_refs_json(refs_table, info->id, json_wtr);
478 
479 	jsonw_end_object(json_wtr);
480 
481 	return 0;
482 }
483 
484 static void show_link_header_plain(struct bpf_link_info *info)
485 {
486 	const char *link_type_str;
487 
488 	printf("%u: ", info->id);
489 	link_type_str = libbpf_bpf_link_type_str(info->type);
490 	if (link_type_str)
491 		printf("%s  ", link_type_str);
492 	else
493 		printf("type %u  ", info->type);
494 
495 	if (info->type == BPF_LINK_TYPE_STRUCT_OPS)
496 		printf("map %u  ", info->struct_ops.map_id);
497 	else
498 		printf("prog %u  ", info->prog_id);
499 }
500 
501 static void show_link_attach_type_plain(__u32 attach_type)
502 {
503 	const char *attach_type_str;
504 
505 	attach_type_str = libbpf_bpf_attach_type_str(attach_type);
506 	if (attach_type_str)
507 		printf("attach_type %s  ", attach_type_str);
508 	else
509 		printf("attach_type %u  ", attach_type);
510 }
511 
512 static void show_iter_plain(struct bpf_link_info *info)
513 {
514 	const char *target_name = u64_to_ptr(info->iter.target_name);
515 
516 	printf("target_name %s  ", target_name);
517 
518 	if (is_iter_map_target(target_name))
519 		printf("map_id %u  ", info->iter.map.map_id);
520 	else if (is_iter_task_target(target_name)) {
521 		if (info->iter.task.tid)
522 			printf("tid %u ", info->iter.task.tid);
523 		else if (info->iter.task.pid)
524 			printf("pid %u ", info->iter.task.pid);
525 	}
526 
527 	if (is_iter_cgroup_target(target_name)) {
528 		printf("cgroup_id %llu  ", info->iter.cgroup.cgroup_id);
529 		printf("order %s  ",
530 		       cgroup_order_string(info->iter.cgroup.order));
531 	}
532 }
533 
534 static const char * const pf2name[] = {
535 	[NFPROTO_INET] = "inet",
536 	[NFPROTO_IPV4] = "ip",
537 	[NFPROTO_ARP] = "arp",
538 	[NFPROTO_NETDEV] = "netdev",
539 	[NFPROTO_BRIDGE] = "bridge",
540 	[NFPROTO_IPV6] = "ip6",
541 };
542 
543 static const char * const inethook2name[] = {
544 	[NF_INET_PRE_ROUTING] = "prerouting",
545 	[NF_INET_LOCAL_IN] = "input",
546 	[NF_INET_FORWARD] = "forward",
547 	[NF_INET_LOCAL_OUT] = "output",
548 	[NF_INET_POST_ROUTING] = "postrouting",
549 };
550 
551 static const char * const arphook2name[] = {
552 	[NF_ARP_IN] = "input",
553 	[NF_ARP_OUT] = "output",
554 };
555 
556 void netfilter_dump_plain(const struct bpf_link_info *info)
557 {
558 	const char *hookname = NULL, *pfname = NULL;
559 	unsigned int hook = info->netfilter.hooknum;
560 	unsigned int pf = info->netfilter.pf;
561 
562 	if (pf < ARRAY_SIZE(pf2name))
563 		pfname = pf2name[pf];
564 
565 	switch (pf) {
566 	case NFPROTO_BRIDGE: /* bridge shares numbers with enum nf_inet_hooks */
567 	case NFPROTO_IPV4:
568 	case NFPROTO_IPV6:
569 	case NFPROTO_INET:
570 		if (hook < ARRAY_SIZE(inethook2name))
571 			hookname = inethook2name[hook];
572 		break;
573 	case NFPROTO_ARP:
574 		if (hook < ARRAY_SIZE(arphook2name))
575 			hookname = arphook2name[hook];
576 	default:
577 		break;
578 	}
579 
580 	if (pfname)
581 		printf("\n\t%s", pfname);
582 	else
583 		printf("\n\tpf: %d", pf);
584 
585 	if (hookname)
586 		printf(" %s", hookname);
587 	else
588 		printf(", hook %u,", hook);
589 
590 	printf(" prio %d", info->netfilter.priority);
591 
592 	if (info->netfilter.flags)
593 		printf(" flags 0x%x", info->netfilter.flags);
594 }
595 
596 static void show_kprobe_multi_plain(struct bpf_link_info *info)
597 {
598 	__u32 i, j = 0;
599 	__u64 *addrs;
600 
601 	if (!info->kprobe_multi.count)
602 		return;
603 
604 	if (info->kprobe_multi.flags & BPF_F_KPROBE_MULTI_RETURN)
605 		printf("\n\tkretprobe.multi  ");
606 	else
607 		printf("\n\tkprobe.multi  ");
608 	printf("func_cnt %u  ", info->kprobe_multi.count);
609 	addrs = (__u64 *)u64_to_ptr(info->kprobe_multi.addrs);
610 	qsort(addrs, info->kprobe_multi.count, sizeof(__u64), cmp_u64);
611 
612 	/* Load it once for all. */
613 	if (!dd.sym_count)
614 		kernel_syms_load(&dd);
615 	if (!dd.sym_count)
616 		return;
617 
618 	printf("\n\t%-16s %s", "addr", "func [module]");
619 	for (i = 0; i < dd.sym_count; i++) {
620 		if (dd.sym_mapping[i].address != addrs[j])
621 			continue;
622 		printf("\n\t%016lx %s",
623 		       dd.sym_mapping[i].address, dd.sym_mapping[i].name);
624 		if (dd.sym_mapping[i].module[0] != '\0')
625 			printf(" [%s]  ", dd.sym_mapping[i].module);
626 		else
627 			printf("  ");
628 
629 		if (j++ == info->kprobe_multi.count)
630 			break;
631 	}
632 }
633 
634 static void show_perf_event_kprobe_plain(struct bpf_link_info *info)
635 {
636 	const char *buf;
637 
638 	buf = u64_to_ptr(info->perf_event.kprobe.func_name);
639 	if (buf[0] == '\0' && !info->perf_event.kprobe.addr)
640 		return;
641 
642 	if (info->perf_event.type == BPF_PERF_EVENT_KRETPROBE)
643 		printf("\n\tkretprobe ");
644 	else
645 		printf("\n\tkprobe ");
646 	if (info->perf_event.kprobe.addr)
647 		printf("%llx ", info->perf_event.kprobe.addr);
648 	printf("%s", buf);
649 	if (info->perf_event.kprobe.offset)
650 		printf("+%#x", info->perf_event.kprobe.offset);
651 	printf("  ");
652 }
653 
654 static void show_perf_event_uprobe_plain(struct bpf_link_info *info)
655 {
656 	const char *buf;
657 
658 	buf = u64_to_ptr(info->perf_event.uprobe.file_name);
659 	if (buf[0] == '\0')
660 		return;
661 
662 	if (info->perf_event.type == BPF_PERF_EVENT_URETPROBE)
663 		printf("\n\turetprobe ");
664 	else
665 		printf("\n\tuprobe ");
666 	printf("%s+%#x  ", buf, info->perf_event.uprobe.offset);
667 }
668 
669 static void show_perf_event_tracepoint_plain(struct bpf_link_info *info)
670 {
671 	const char *buf;
672 
673 	buf = u64_to_ptr(info->perf_event.tracepoint.tp_name);
674 	if (buf[0] == '\0')
675 		return;
676 
677 	printf("\n\ttracepoint %s  ", buf);
678 }
679 
680 static void show_perf_event_event_plain(struct bpf_link_info *info)
681 {
682 	__u64 config = info->perf_event.event.config;
683 	__u32 type = info->perf_event.event.type;
684 	const char *perf_type, *perf_config;
685 
686 	printf("\n\tevent ");
687 	perf_type = perf_event_name(perf_type_name, type);
688 	if (perf_type)
689 		printf("%s:", perf_type);
690 	else
691 		printf("%u :", type);
692 
693 	perf_config = perf_config_str(type, config);
694 	if (perf_config)
695 		printf("%s  ", perf_config);
696 	else
697 		printf("%llu  ", config);
698 
699 	if (type == PERF_TYPE_HW_CACHE && perf_config)
700 		free((void *)perf_config);
701 }
702 
703 static int show_link_close_plain(int fd, struct bpf_link_info *info)
704 {
705 	struct bpf_prog_info prog_info;
706 	const char *prog_type_str;
707 	int err;
708 
709 	show_link_header_plain(info);
710 
711 	switch (info->type) {
712 	case BPF_LINK_TYPE_RAW_TRACEPOINT:
713 		printf("\n\ttp '%s'  ",
714 		       (const char *)u64_to_ptr(info->raw_tracepoint.tp_name));
715 		break;
716 	case BPF_LINK_TYPE_TRACING:
717 		err = get_prog_info(info->prog_id, &prog_info);
718 		if (err)
719 			return err;
720 
721 		prog_type_str = libbpf_bpf_prog_type_str(prog_info.type);
722 		/* libbpf will return NULL for variants unknown to it. */
723 		if (prog_type_str)
724 			printf("\n\tprog_type %s  ", prog_type_str);
725 		else
726 			printf("\n\tprog_type %u  ", prog_info.type);
727 
728 		show_link_attach_type_plain(info->tracing.attach_type);
729 		if (info->tracing.target_obj_id || info->tracing.target_btf_id)
730 			printf("\n\ttarget_obj_id %u  target_btf_id %u  ",
731 			       info->tracing.target_obj_id,
732 			       info->tracing.target_btf_id);
733 		break;
734 	case BPF_LINK_TYPE_CGROUP:
735 		printf("\n\tcgroup_id %zu  ", (size_t)info->cgroup.cgroup_id);
736 		show_link_attach_type_plain(info->cgroup.attach_type);
737 		break;
738 	case BPF_LINK_TYPE_ITER:
739 		show_iter_plain(info);
740 		break;
741 	case BPF_LINK_TYPE_NETNS:
742 		printf("\n\tnetns_ino %u  ", info->netns.netns_ino);
743 		show_link_attach_type_plain(info->netns.attach_type);
744 		break;
745 	case BPF_LINK_TYPE_NETFILTER:
746 		netfilter_dump_plain(info);
747 		break;
748 	case BPF_LINK_TYPE_KPROBE_MULTI:
749 		show_kprobe_multi_plain(info);
750 		break;
751 	case BPF_LINK_TYPE_PERF_EVENT:
752 		switch (info->perf_event.type) {
753 		case BPF_PERF_EVENT_EVENT:
754 			show_perf_event_event_plain(info);
755 			break;
756 		case BPF_PERF_EVENT_TRACEPOINT:
757 			show_perf_event_tracepoint_plain(info);
758 			break;
759 		case BPF_PERF_EVENT_KPROBE:
760 		case BPF_PERF_EVENT_KRETPROBE:
761 			show_perf_event_kprobe_plain(info);
762 			break;
763 		case BPF_PERF_EVENT_UPROBE:
764 		case BPF_PERF_EVENT_URETPROBE:
765 			show_perf_event_uprobe_plain(info);
766 			break;
767 		default:
768 			break;
769 		}
770 		break;
771 	default:
772 		break;
773 	}
774 
775 	if (!hashmap__empty(link_table)) {
776 		struct hashmap_entry *entry;
777 
778 		hashmap__for_each_key_entry(link_table, entry, info->id)
779 			printf("\n\tpinned %s", (char *)entry->pvalue);
780 	}
781 	emit_obj_refs_plain(refs_table, info->id, "\n\tpids ");
782 
783 	printf("\n");
784 
785 	return 0;
786 }
787 
788 static int do_show_link(int fd)
789 {
790 	struct bpf_link_info info;
791 	__u32 len = sizeof(info);
792 	__u64 *addrs = NULL;
793 	char buf[PATH_MAX];
794 	int count;
795 	int err;
796 
797 	memset(&info, 0, sizeof(info));
798 	buf[0] = '\0';
799 again:
800 	err = bpf_link_get_info_by_fd(fd, &info, &len);
801 	if (err) {
802 		p_err("can't get link info: %s",
803 		      strerror(errno));
804 		close(fd);
805 		return err;
806 	}
807 	if (info.type == BPF_LINK_TYPE_RAW_TRACEPOINT &&
808 	    !info.raw_tracepoint.tp_name) {
809 		info.raw_tracepoint.tp_name = ptr_to_u64(&buf);
810 		info.raw_tracepoint.tp_name_len = sizeof(buf);
811 		goto again;
812 	}
813 	if (info.type == BPF_LINK_TYPE_ITER &&
814 	    !info.iter.target_name) {
815 		info.iter.target_name = ptr_to_u64(&buf);
816 		info.iter.target_name_len = sizeof(buf);
817 		goto again;
818 	}
819 	if (info.type == BPF_LINK_TYPE_KPROBE_MULTI &&
820 	    !info.kprobe_multi.addrs) {
821 		count = info.kprobe_multi.count;
822 		if (count) {
823 			addrs = calloc(count, sizeof(__u64));
824 			if (!addrs) {
825 				p_err("mem alloc failed");
826 				close(fd);
827 				return -ENOMEM;
828 			}
829 			info.kprobe_multi.addrs = ptr_to_u64(addrs);
830 			goto again;
831 		}
832 	}
833 	if (info.type == BPF_LINK_TYPE_PERF_EVENT) {
834 		switch (info.perf_event.type) {
835 		case BPF_PERF_EVENT_TRACEPOINT:
836 			if (!info.perf_event.tracepoint.tp_name) {
837 				info.perf_event.tracepoint.tp_name = ptr_to_u64(&buf);
838 				info.perf_event.tracepoint.name_len = sizeof(buf);
839 				goto again;
840 			}
841 			break;
842 		case BPF_PERF_EVENT_KPROBE:
843 		case BPF_PERF_EVENT_KRETPROBE:
844 			if (!info.perf_event.kprobe.func_name) {
845 				info.perf_event.kprobe.func_name = ptr_to_u64(&buf);
846 				info.perf_event.kprobe.name_len = sizeof(buf);
847 				goto again;
848 			}
849 			break;
850 		case BPF_PERF_EVENT_UPROBE:
851 		case BPF_PERF_EVENT_URETPROBE:
852 			if (!info.perf_event.uprobe.file_name) {
853 				info.perf_event.uprobe.file_name = ptr_to_u64(&buf);
854 				info.perf_event.uprobe.name_len = sizeof(buf);
855 				goto again;
856 			}
857 			break;
858 		default:
859 			break;
860 		}
861 	}
862 
863 	if (json_output)
864 		show_link_close_json(fd, &info);
865 	else
866 		show_link_close_plain(fd, &info);
867 
868 	if (addrs)
869 		free(addrs);
870 	close(fd);
871 	return 0;
872 }
873 
874 static int do_show(int argc, char **argv)
875 {
876 	__u32 id = 0;
877 	int err, fd;
878 
879 	if (show_pinned) {
880 		link_table = hashmap__new(hash_fn_for_key_as_id,
881 					  equal_fn_for_key_as_id, NULL);
882 		if (IS_ERR(link_table)) {
883 			p_err("failed to create hashmap for pinned paths");
884 			return -1;
885 		}
886 		build_pinned_obj_table(link_table, BPF_OBJ_LINK);
887 	}
888 	build_obj_refs_table(&refs_table, BPF_OBJ_LINK);
889 
890 	if (argc == 2) {
891 		fd = link_parse_fd(&argc, &argv);
892 		if (fd < 0)
893 			return fd;
894 		do_show_link(fd);
895 		goto out;
896 	}
897 
898 	if (argc)
899 		return BAD_ARG();
900 
901 	if (json_output)
902 		jsonw_start_array(json_wtr);
903 	while (true) {
904 		err = bpf_link_get_next_id(id, &id);
905 		if (err) {
906 			if (errno == ENOENT)
907 				break;
908 			p_err("can't get next link: %s%s", strerror(errno),
909 			      errno == EINVAL ? " -- kernel too old?" : "");
910 			break;
911 		}
912 
913 		fd = bpf_link_get_fd_by_id(id);
914 		if (fd < 0) {
915 			if (errno == ENOENT)
916 				continue;
917 			p_err("can't get link by id (%u): %s",
918 			      id, strerror(errno));
919 			break;
920 		}
921 
922 		err = do_show_link(fd);
923 		if (err)
924 			break;
925 	}
926 	if (json_output)
927 		jsonw_end_array(json_wtr);
928 
929 	delete_obj_refs_table(refs_table);
930 
931 	if (show_pinned)
932 		delete_pinned_obj_table(link_table);
933 
934 out:
935 	if (dd.sym_count)
936 		kernel_syms_destroy(&dd);
937 	return errno == ENOENT ? 0 : -1;
938 }
939 
940 static int do_pin(int argc, char **argv)
941 {
942 	int err;
943 
944 	err = do_pin_any(argc, argv, link_parse_fd);
945 	if (!err && json_output)
946 		jsonw_null(json_wtr);
947 	return err;
948 }
949 
950 static int do_detach(int argc, char **argv)
951 {
952 	int err, fd;
953 
954 	if (argc != 2) {
955 		p_err("link specifier is invalid or missing\n");
956 		return 1;
957 	}
958 
959 	fd = link_parse_fd(&argc, &argv);
960 	if (fd < 0)
961 		return 1;
962 
963 	err = bpf_link_detach(fd);
964 	if (err)
965 		err = -errno;
966 	close(fd);
967 	if (err) {
968 		p_err("failed link detach: %s", strerror(-err));
969 		return 1;
970 	}
971 
972 	if (json_output)
973 		jsonw_null(json_wtr);
974 
975 	return 0;
976 }
977 
978 static int do_help(int argc, char **argv)
979 {
980 	if (json_output) {
981 		jsonw_null(json_wtr);
982 		return 0;
983 	}
984 
985 	fprintf(stderr,
986 		"Usage: %1$s %2$s { show | list }   [LINK]\n"
987 		"       %1$s %2$s pin        LINK  FILE\n"
988 		"       %1$s %2$s detach     LINK\n"
989 		"       %1$s %2$s help\n"
990 		"\n"
991 		"       " HELP_SPEC_LINK "\n"
992 		"       " HELP_SPEC_OPTIONS " |\n"
993 		"                    {-f|--bpffs} | {-n|--nomount} }\n"
994 		"",
995 		bin_name, argv[-2]);
996 
997 	return 0;
998 }
999 
1000 static const struct cmd cmds[] = {
1001 	{ "show",	do_show },
1002 	{ "list",	do_show },
1003 	{ "help",	do_help },
1004 	{ "pin",	do_pin },
1005 	{ "detach",	do_detach },
1006 	{ 0 }
1007 };
1008 
1009 int do_link(int argc, char **argv)
1010 {
1011 	return cmd_select(cmds, argc, argv, do_help);
1012 }
1013