xref: /linux/tools/bpf/bpftool/link.c (revision 79997eda0d31bc68203c95ecb978773ee6ce7a1f)
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 void
298 show_perf_event_kprobe_json(struct bpf_link_info *info, json_writer_t *wtr)
299 {
300 	jsonw_bool_field(wtr, "retprobe", info->perf_event.type == BPF_PERF_EVENT_KRETPROBE);
301 	jsonw_uint_field(wtr, "addr", info->perf_event.kprobe.addr);
302 	jsonw_string_field(wtr, "func",
303 			   u64_to_ptr(info->perf_event.kprobe.func_name));
304 	jsonw_uint_field(wtr, "offset", info->perf_event.kprobe.offset);
305 	jsonw_uint_field(wtr, "missed", info->perf_event.kprobe.missed);
306 }
307 
308 static void
309 show_perf_event_uprobe_json(struct bpf_link_info *info, json_writer_t *wtr)
310 {
311 	jsonw_bool_field(wtr, "retprobe", info->perf_event.type == BPF_PERF_EVENT_URETPROBE);
312 	jsonw_string_field(wtr, "file",
313 			   u64_to_ptr(info->perf_event.uprobe.file_name));
314 	jsonw_uint_field(wtr, "offset", info->perf_event.uprobe.offset);
315 }
316 
317 static void
318 show_perf_event_tracepoint_json(struct bpf_link_info *info, json_writer_t *wtr)
319 {
320 	jsonw_string_field(wtr, "tracepoint",
321 			   u64_to_ptr(info->perf_event.tracepoint.tp_name));
322 }
323 
324 static char *perf_config_hw_cache_str(__u64 config)
325 {
326 	const char *hw_cache, *result, *op;
327 	char *str = malloc(PERF_HW_CACHE_LEN);
328 
329 	if (!str) {
330 		p_err("mem alloc failed");
331 		return NULL;
332 	}
333 
334 	hw_cache = perf_event_name(evsel__hw_cache, config & 0xff);
335 	if (hw_cache)
336 		snprintf(str, PERF_HW_CACHE_LEN, "%s-", hw_cache);
337 	else
338 		snprintf(str, PERF_HW_CACHE_LEN, "%lld-", config & 0xff);
339 
340 	op = perf_event_name(evsel__hw_cache_op, (config >> 8) & 0xff);
341 	if (op)
342 		snprintf(str + strlen(str), PERF_HW_CACHE_LEN - strlen(str),
343 			 "%s-", op);
344 	else
345 		snprintf(str + strlen(str), PERF_HW_CACHE_LEN - strlen(str),
346 			 "%lld-", (config >> 8) & 0xff);
347 
348 	result = perf_event_name(evsel__hw_cache_result, config >> 16);
349 	if (result)
350 		snprintf(str + strlen(str), PERF_HW_CACHE_LEN - strlen(str),
351 			 "%s", result);
352 	else
353 		snprintf(str + strlen(str), PERF_HW_CACHE_LEN - strlen(str),
354 			 "%lld", config >> 16);
355 	return str;
356 }
357 
358 static const char *perf_config_str(__u32 type, __u64 config)
359 {
360 	const char *perf_config;
361 
362 	switch (type) {
363 	case PERF_TYPE_HARDWARE:
364 		perf_config = perf_event_name(event_symbols_hw, config);
365 		break;
366 	case PERF_TYPE_SOFTWARE:
367 		perf_config = perf_event_name(event_symbols_sw, config);
368 		break;
369 	case PERF_TYPE_HW_CACHE:
370 		perf_config = perf_config_hw_cache_str(config);
371 		break;
372 	default:
373 		perf_config = NULL;
374 		break;
375 	}
376 	return perf_config;
377 }
378 
379 static void
380 show_perf_event_event_json(struct bpf_link_info *info, json_writer_t *wtr)
381 {
382 	__u64 config = info->perf_event.event.config;
383 	__u32 type = info->perf_event.event.type;
384 	const char *perf_type, *perf_config;
385 
386 	perf_type = perf_event_name(perf_type_name, type);
387 	if (perf_type)
388 		jsonw_string_field(wtr, "event_type", perf_type);
389 	else
390 		jsonw_uint_field(wtr, "event_type", type);
391 
392 	perf_config = perf_config_str(type, config);
393 	if (perf_config)
394 		jsonw_string_field(wtr, "event_config", perf_config);
395 	else
396 		jsonw_uint_field(wtr, "event_config", config);
397 
398 	if (type == PERF_TYPE_HW_CACHE && perf_config)
399 		free((void *)perf_config);
400 }
401 
402 static int show_link_close_json(int fd, struct bpf_link_info *info)
403 {
404 	struct bpf_prog_info prog_info;
405 	const char *prog_type_str;
406 	int err;
407 
408 	jsonw_start_object(json_wtr);
409 
410 	show_link_header_json(info, json_wtr);
411 
412 	switch (info->type) {
413 	case BPF_LINK_TYPE_RAW_TRACEPOINT:
414 		jsonw_string_field(json_wtr, "tp_name",
415 				   u64_to_ptr(info->raw_tracepoint.tp_name));
416 		break;
417 	case BPF_LINK_TYPE_TRACING:
418 		err = get_prog_info(info->prog_id, &prog_info);
419 		if (err)
420 			return err;
421 
422 		prog_type_str = libbpf_bpf_prog_type_str(prog_info.type);
423 		/* libbpf will return NULL for variants unknown to it. */
424 		if (prog_type_str)
425 			jsonw_string_field(json_wtr, "prog_type", prog_type_str);
426 		else
427 			jsonw_uint_field(json_wtr, "prog_type", prog_info.type);
428 
429 		show_link_attach_type_json(info->tracing.attach_type,
430 					   json_wtr);
431 		jsonw_uint_field(json_wtr, "target_obj_id", info->tracing.target_obj_id);
432 		jsonw_uint_field(json_wtr, "target_btf_id", info->tracing.target_btf_id);
433 		break;
434 	case BPF_LINK_TYPE_CGROUP:
435 		jsonw_lluint_field(json_wtr, "cgroup_id",
436 				   info->cgroup.cgroup_id);
437 		show_link_attach_type_json(info->cgroup.attach_type, json_wtr);
438 		break;
439 	case BPF_LINK_TYPE_ITER:
440 		show_iter_json(info, json_wtr);
441 		break;
442 	case BPF_LINK_TYPE_NETNS:
443 		jsonw_uint_field(json_wtr, "netns_ino",
444 				 info->netns.netns_ino);
445 		show_link_attach_type_json(info->netns.attach_type, json_wtr);
446 		break;
447 	case BPF_LINK_TYPE_NETFILTER:
448 		netfilter_dump_json(info, json_wtr);
449 		break;
450 	case BPF_LINK_TYPE_TCX:
451 		show_link_ifindex_json(info->tcx.ifindex, json_wtr);
452 		show_link_attach_type_json(info->tcx.attach_type, json_wtr);
453 		break;
454 	case BPF_LINK_TYPE_NETKIT:
455 		show_link_ifindex_json(info->netkit.ifindex, json_wtr);
456 		show_link_attach_type_json(info->netkit.attach_type, json_wtr);
457 		break;
458 	case BPF_LINK_TYPE_XDP:
459 		show_link_ifindex_json(info->xdp.ifindex, json_wtr);
460 		break;
461 	case BPF_LINK_TYPE_STRUCT_OPS:
462 		jsonw_uint_field(json_wtr, "map_id",
463 				 info->struct_ops.map_id);
464 		break;
465 	case BPF_LINK_TYPE_KPROBE_MULTI:
466 		show_kprobe_multi_json(info, json_wtr);
467 		break;
468 	case BPF_LINK_TYPE_PERF_EVENT:
469 		switch (info->perf_event.type) {
470 		case BPF_PERF_EVENT_EVENT:
471 			show_perf_event_event_json(info, json_wtr);
472 			break;
473 		case BPF_PERF_EVENT_TRACEPOINT:
474 			show_perf_event_tracepoint_json(info, json_wtr);
475 			break;
476 		case BPF_PERF_EVENT_KPROBE:
477 		case BPF_PERF_EVENT_KRETPROBE:
478 			show_perf_event_kprobe_json(info, json_wtr);
479 			break;
480 		case BPF_PERF_EVENT_UPROBE:
481 		case BPF_PERF_EVENT_URETPROBE:
482 			show_perf_event_uprobe_json(info, json_wtr);
483 			break;
484 		default:
485 			break;
486 		}
487 		break;
488 	default:
489 		break;
490 	}
491 
492 	if (!hashmap__empty(link_table)) {
493 		struct hashmap_entry *entry;
494 
495 		jsonw_name(json_wtr, "pinned");
496 		jsonw_start_array(json_wtr);
497 		hashmap__for_each_key_entry(link_table, entry, info->id)
498 			jsonw_string(json_wtr, entry->pvalue);
499 		jsonw_end_array(json_wtr);
500 	}
501 
502 	emit_obj_refs_json(refs_table, info->id, json_wtr);
503 
504 	jsonw_end_object(json_wtr);
505 
506 	return 0;
507 }
508 
509 static void show_link_header_plain(struct bpf_link_info *info)
510 {
511 	const char *link_type_str;
512 
513 	printf("%u: ", info->id);
514 	link_type_str = libbpf_bpf_link_type_str(info->type);
515 	if (link_type_str)
516 		printf("%s  ", link_type_str);
517 	else
518 		printf("type %u  ", info->type);
519 
520 	if (info->type == BPF_LINK_TYPE_STRUCT_OPS)
521 		printf("map %u  ", info->struct_ops.map_id);
522 	else
523 		printf("prog %u  ", info->prog_id);
524 }
525 
526 static void show_link_attach_type_plain(__u32 attach_type)
527 {
528 	const char *attach_type_str;
529 
530 	attach_type_str = libbpf_bpf_attach_type_str(attach_type);
531 	if (attach_type_str)
532 		printf("attach_type %s  ", attach_type_str);
533 	else
534 		printf("attach_type %u  ", attach_type);
535 }
536 
537 static void show_link_ifindex_plain(__u32 ifindex)
538 {
539 	char devname[IF_NAMESIZE * 2] = "(unknown)";
540 	char tmpname[IF_NAMESIZE];
541 	char *ret = NULL;
542 
543 	if (ifindex)
544 		ret = if_indextoname(ifindex, tmpname);
545 	else
546 		snprintf(devname, sizeof(devname), "(detached)");
547 	if (ret)
548 		snprintf(devname, sizeof(devname), "%s(%d)",
549 			 tmpname, ifindex);
550 	printf("ifindex %s  ", devname);
551 }
552 
553 static void show_iter_plain(struct bpf_link_info *info)
554 {
555 	const char *target_name = u64_to_ptr(info->iter.target_name);
556 
557 	printf("target_name %s  ", target_name);
558 
559 	if (is_iter_map_target(target_name))
560 		printf("map_id %u  ", info->iter.map.map_id);
561 	else if (is_iter_task_target(target_name)) {
562 		if (info->iter.task.tid)
563 			printf("tid %u ", info->iter.task.tid);
564 		else if (info->iter.task.pid)
565 			printf("pid %u ", info->iter.task.pid);
566 	}
567 
568 	if (is_iter_cgroup_target(target_name)) {
569 		printf("cgroup_id %llu  ", info->iter.cgroup.cgroup_id);
570 		printf("order %s  ",
571 		       cgroup_order_string(info->iter.cgroup.order));
572 	}
573 }
574 
575 static const char * const pf2name[] = {
576 	[NFPROTO_INET] = "inet",
577 	[NFPROTO_IPV4] = "ip",
578 	[NFPROTO_ARP] = "arp",
579 	[NFPROTO_NETDEV] = "netdev",
580 	[NFPROTO_BRIDGE] = "bridge",
581 	[NFPROTO_IPV6] = "ip6",
582 };
583 
584 static const char * const inethook2name[] = {
585 	[NF_INET_PRE_ROUTING] = "prerouting",
586 	[NF_INET_LOCAL_IN] = "input",
587 	[NF_INET_FORWARD] = "forward",
588 	[NF_INET_LOCAL_OUT] = "output",
589 	[NF_INET_POST_ROUTING] = "postrouting",
590 };
591 
592 static const char * const arphook2name[] = {
593 	[NF_ARP_IN] = "input",
594 	[NF_ARP_OUT] = "output",
595 };
596 
597 void netfilter_dump_plain(const struct bpf_link_info *info)
598 {
599 	const char *hookname = NULL, *pfname = NULL;
600 	unsigned int hook = info->netfilter.hooknum;
601 	unsigned int pf = info->netfilter.pf;
602 
603 	if (pf < ARRAY_SIZE(pf2name))
604 		pfname = pf2name[pf];
605 
606 	switch (pf) {
607 	case NFPROTO_BRIDGE: /* bridge shares numbers with enum nf_inet_hooks */
608 	case NFPROTO_IPV4:
609 	case NFPROTO_IPV6:
610 	case NFPROTO_INET:
611 		if (hook < ARRAY_SIZE(inethook2name))
612 			hookname = inethook2name[hook];
613 		break;
614 	case NFPROTO_ARP:
615 		if (hook < ARRAY_SIZE(arphook2name))
616 			hookname = arphook2name[hook];
617 	default:
618 		break;
619 	}
620 
621 	if (pfname)
622 		printf("\n\t%s", pfname);
623 	else
624 		printf("\n\tpf: %d", pf);
625 
626 	if (hookname)
627 		printf(" %s", hookname);
628 	else
629 		printf(", hook %u,", hook);
630 
631 	printf(" prio %d", info->netfilter.priority);
632 
633 	if (info->netfilter.flags)
634 		printf(" flags 0x%x", info->netfilter.flags);
635 }
636 
637 static void show_kprobe_multi_plain(struct bpf_link_info *info)
638 {
639 	__u32 i, j = 0;
640 	__u64 *addrs;
641 
642 	if (!info->kprobe_multi.count)
643 		return;
644 
645 	if (info->kprobe_multi.flags & BPF_F_KPROBE_MULTI_RETURN)
646 		printf("\n\tkretprobe.multi  ");
647 	else
648 		printf("\n\tkprobe.multi  ");
649 	printf("func_cnt %u  ", info->kprobe_multi.count);
650 	if (info->kprobe_multi.missed)
651 		printf("missed %llu  ", info->kprobe_multi.missed);
652 	addrs = (__u64 *)u64_to_ptr(info->kprobe_multi.addrs);
653 	qsort(addrs, info->kprobe_multi.count, sizeof(__u64), cmp_u64);
654 
655 	/* Load it once for all. */
656 	if (!dd.sym_count)
657 		kernel_syms_load(&dd);
658 	if (!dd.sym_count)
659 		return;
660 
661 	printf("\n\t%-16s %s", "addr", "func [module]");
662 	for (i = 0; i < dd.sym_count; i++) {
663 		if (dd.sym_mapping[i].address != addrs[j])
664 			continue;
665 		printf("\n\t%016lx %s",
666 		       dd.sym_mapping[i].address, dd.sym_mapping[i].name);
667 		if (dd.sym_mapping[i].module[0] != '\0')
668 			printf(" [%s]  ", dd.sym_mapping[i].module);
669 		else
670 			printf("  ");
671 
672 		if (j++ == info->kprobe_multi.count)
673 			break;
674 	}
675 }
676 
677 static void show_perf_event_kprobe_plain(struct bpf_link_info *info)
678 {
679 	const char *buf;
680 
681 	buf = u64_to_ptr(info->perf_event.kprobe.func_name);
682 	if (buf[0] == '\0' && !info->perf_event.kprobe.addr)
683 		return;
684 
685 	if (info->perf_event.type == BPF_PERF_EVENT_KRETPROBE)
686 		printf("\n\tkretprobe ");
687 	else
688 		printf("\n\tkprobe ");
689 	if (info->perf_event.kprobe.addr)
690 		printf("%llx ", info->perf_event.kprobe.addr);
691 	printf("%s", buf);
692 	if (info->perf_event.kprobe.offset)
693 		printf("+%#x", info->perf_event.kprobe.offset);
694 	if (info->perf_event.kprobe.missed)
695 		printf("  missed %llu", info->perf_event.kprobe.missed);
696 	printf("  ");
697 }
698 
699 static void show_perf_event_uprobe_plain(struct bpf_link_info *info)
700 {
701 	const char *buf;
702 
703 	buf = u64_to_ptr(info->perf_event.uprobe.file_name);
704 	if (buf[0] == '\0')
705 		return;
706 
707 	if (info->perf_event.type == BPF_PERF_EVENT_URETPROBE)
708 		printf("\n\turetprobe ");
709 	else
710 		printf("\n\tuprobe ");
711 	printf("%s+%#x  ", buf, info->perf_event.uprobe.offset);
712 }
713 
714 static void show_perf_event_tracepoint_plain(struct bpf_link_info *info)
715 {
716 	const char *buf;
717 
718 	buf = u64_to_ptr(info->perf_event.tracepoint.tp_name);
719 	if (buf[0] == '\0')
720 		return;
721 
722 	printf("\n\ttracepoint %s  ", buf);
723 }
724 
725 static void show_perf_event_event_plain(struct bpf_link_info *info)
726 {
727 	__u64 config = info->perf_event.event.config;
728 	__u32 type = info->perf_event.event.type;
729 	const char *perf_type, *perf_config;
730 
731 	printf("\n\tevent ");
732 	perf_type = perf_event_name(perf_type_name, type);
733 	if (perf_type)
734 		printf("%s:", perf_type);
735 	else
736 		printf("%u :", type);
737 
738 	perf_config = perf_config_str(type, config);
739 	if (perf_config)
740 		printf("%s  ", perf_config);
741 	else
742 		printf("%llu  ", config);
743 
744 	if (type == PERF_TYPE_HW_CACHE && perf_config)
745 		free((void *)perf_config);
746 }
747 
748 static int show_link_close_plain(int fd, struct bpf_link_info *info)
749 {
750 	struct bpf_prog_info prog_info;
751 	const char *prog_type_str;
752 	int err;
753 
754 	show_link_header_plain(info);
755 
756 	switch (info->type) {
757 	case BPF_LINK_TYPE_RAW_TRACEPOINT:
758 		printf("\n\ttp '%s'  ",
759 		       (const char *)u64_to_ptr(info->raw_tracepoint.tp_name));
760 		break;
761 	case BPF_LINK_TYPE_TRACING:
762 		err = get_prog_info(info->prog_id, &prog_info);
763 		if (err)
764 			return err;
765 
766 		prog_type_str = libbpf_bpf_prog_type_str(prog_info.type);
767 		/* libbpf will return NULL for variants unknown to it. */
768 		if (prog_type_str)
769 			printf("\n\tprog_type %s  ", prog_type_str);
770 		else
771 			printf("\n\tprog_type %u  ", prog_info.type);
772 
773 		show_link_attach_type_plain(info->tracing.attach_type);
774 		if (info->tracing.target_obj_id || info->tracing.target_btf_id)
775 			printf("\n\ttarget_obj_id %u  target_btf_id %u  ",
776 			       info->tracing.target_obj_id,
777 			       info->tracing.target_btf_id);
778 		break;
779 	case BPF_LINK_TYPE_CGROUP:
780 		printf("\n\tcgroup_id %zu  ", (size_t)info->cgroup.cgroup_id);
781 		show_link_attach_type_plain(info->cgroup.attach_type);
782 		break;
783 	case BPF_LINK_TYPE_ITER:
784 		show_iter_plain(info);
785 		break;
786 	case BPF_LINK_TYPE_NETNS:
787 		printf("\n\tnetns_ino %u  ", info->netns.netns_ino);
788 		show_link_attach_type_plain(info->netns.attach_type);
789 		break;
790 	case BPF_LINK_TYPE_NETFILTER:
791 		netfilter_dump_plain(info);
792 		break;
793 	case BPF_LINK_TYPE_TCX:
794 		printf("\n\t");
795 		show_link_ifindex_plain(info->tcx.ifindex);
796 		show_link_attach_type_plain(info->tcx.attach_type);
797 		break;
798 	case BPF_LINK_TYPE_NETKIT:
799 		printf("\n\t");
800 		show_link_ifindex_plain(info->netkit.ifindex);
801 		show_link_attach_type_plain(info->netkit.attach_type);
802 		break;
803 	case BPF_LINK_TYPE_XDP:
804 		printf("\n\t");
805 		show_link_ifindex_plain(info->xdp.ifindex);
806 		break;
807 	case BPF_LINK_TYPE_KPROBE_MULTI:
808 		show_kprobe_multi_plain(info);
809 		break;
810 	case BPF_LINK_TYPE_PERF_EVENT:
811 		switch (info->perf_event.type) {
812 		case BPF_PERF_EVENT_EVENT:
813 			show_perf_event_event_plain(info);
814 			break;
815 		case BPF_PERF_EVENT_TRACEPOINT:
816 			show_perf_event_tracepoint_plain(info);
817 			break;
818 		case BPF_PERF_EVENT_KPROBE:
819 		case BPF_PERF_EVENT_KRETPROBE:
820 			show_perf_event_kprobe_plain(info);
821 			break;
822 		case BPF_PERF_EVENT_UPROBE:
823 		case BPF_PERF_EVENT_URETPROBE:
824 			show_perf_event_uprobe_plain(info);
825 			break;
826 		default:
827 			break;
828 		}
829 		break;
830 	default:
831 		break;
832 	}
833 
834 	if (!hashmap__empty(link_table)) {
835 		struct hashmap_entry *entry;
836 
837 		hashmap__for_each_key_entry(link_table, entry, info->id)
838 			printf("\n\tpinned %s", (char *)entry->pvalue);
839 	}
840 	emit_obj_refs_plain(refs_table, info->id, "\n\tpids ");
841 
842 	printf("\n");
843 
844 	return 0;
845 }
846 
847 static int do_show_link(int fd)
848 {
849 	struct bpf_link_info info;
850 	__u32 len = sizeof(info);
851 	__u64 *addrs = NULL;
852 	char buf[PATH_MAX];
853 	int count;
854 	int err;
855 
856 	memset(&info, 0, sizeof(info));
857 	buf[0] = '\0';
858 again:
859 	err = bpf_link_get_info_by_fd(fd, &info, &len);
860 	if (err) {
861 		p_err("can't get link info: %s",
862 		      strerror(errno));
863 		close(fd);
864 		return err;
865 	}
866 	if (info.type == BPF_LINK_TYPE_RAW_TRACEPOINT &&
867 	    !info.raw_tracepoint.tp_name) {
868 		info.raw_tracepoint.tp_name = ptr_to_u64(&buf);
869 		info.raw_tracepoint.tp_name_len = sizeof(buf);
870 		goto again;
871 	}
872 	if (info.type == BPF_LINK_TYPE_ITER &&
873 	    !info.iter.target_name) {
874 		info.iter.target_name = ptr_to_u64(&buf);
875 		info.iter.target_name_len = sizeof(buf);
876 		goto again;
877 	}
878 	if (info.type == BPF_LINK_TYPE_KPROBE_MULTI &&
879 	    !info.kprobe_multi.addrs) {
880 		count = info.kprobe_multi.count;
881 		if (count) {
882 			addrs = calloc(count, sizeof(__u64));
883 			if (!addrs) {
884 				p_err("mem alloc failed");
885 				close(fd);
886 				return -ENOMEM;
887 			}
888 			info.kprobe_multi.addrs = ptr_to_u64(addrs);
889 			goto again;
890 		}
891 	}
892 	if (info.type == BPF_LINK_TYPE_PERF_EVENT) {
893 		switch (info.perf_event.type) {
894 		case BPF_PERF_EVENT_TRACEPOINT:
895 			if (!info.perf_event.tracepoint.tp_name) {
896 				info.perf_event.tracepoint.tp_name = ptr_to_u64(&buf);
897 				info.perf_event.tracepoint.name_len = sizeof(buf);
898 				goto again;
899 			}
900 			break;
901 		case BPF_PERF_EVENT_KPROBE:
902 		case BPF_PERF_EVENT_KRETPROBE:
903 			if (!info.perf_event.kprobe.func_name) {
904 				info.perf_event.kprobe.func_name = ptr_to_u64(&buf);
905 				info.perf_event.kprobe.name_len = sizeof(buf);
906 				goto again;
907 			}
908 			break;
909 		case BPF_PERF_EVENT_UPROBE:
910 		case BPF_PERF_EVENT_URETPROBE:
911 			if (!info.perf_event.uprobe.file_name) {
912 				info.perf_event.uprobe.file_name = ptr_to_u64(&buf);
913 				info.perf_event.uprobe.name_len = sizeof(buf);
914 				goto again;
915 			}
916 			break;
917 		default:
918 			break;
919 		}
920 	}
921 
922 	if (json_output)
923 		show_link_close_json(fd, &info);
924 	else
925 		show_link_close_plain(fd, &info);
926 
927 	if (addrs)
928 		free(addrs);
929 	close(fd);
930 	return 0;
931 }
932 
933 static int do_show(int argc, char **argv)
934 {
935 	__u32 id = 0;
936 	int err, fd;
937 
938 	if (show_pinned) {
939 		link_table = hashmap__new(hash_fn_for_key_as_id,
940 					  equal_fn_for_key_as_id, NULL);
941 		if (IS_ERR(link_table)) {
942 			p_err("failed to create hashmap for pinned paths");
943 			return -1;
944 		}
945 		build_pinned_obj_table(link_table, BPF_OBJ_LINK);
946 	}
947 	build_obj_refs_table(&refs_table, BPF_OBJ_LINK);
948 
949 	if (argc == 2) {
950 		fd = link_parse_fd(&argc, &argv);
951 		if (fd < 0)
952 			return fd;
953 		do_show_link(fd);
954 		goto out;
955 	}
956 
957 	if (argc)
958 		return BAD_ARG();
959 
960 	if (json_output)
961 		jsonw_start_array(json_wtr);
962 	while (true) {
963 		err = bpf_link_get_next_id(id, &id);
964 		if (err) {
965 			if (errno == ENOENT)
966 				break;
967 			p_err("can't get next link: %s%s", strerror(errno),
968 			      errno == EINVAL ? " -- kernel too old?" : "");
969 			break;
970 		}
971 
972 		fd = bpf_link_get_fd_by_id(id);
973 		if (fd < 0) {
974 			if (errno == ENOENT)
975 				continue;
976 			p_err("can't get link by id (%u): %s",
977 			      id, strerror(errno));
978 			break;
979 		}
980 
981 		err = do_show_link(fd);
982 		if (err)
983 			break;
984 	}
985 	if (json_output)
986 		jsonw_end_array(json_wtr);
987 
988 	delete_obj_refs_table(refs_table);
989 
990 	if (show_pinned)
991 		delete_pinned_obj_table(link_table);
992 
993 out:
994 	if (dd.sym_count)
995 		kernel_syms_destroy(&dd);
996 	return errno == ENOENT ? 0 : -1;
997 }
998 
999 static int do_pin(int argc, char **argv)
1000 {
1001 	int err;
1002 
1003 	err = do_pin_any(argc, argv, link_parse_fd);
1004 	if (!err && json_output)
1005 		jsonw_null(json_wtr);
1006 	return err;
1007 }
1008 
1009 static int do_detach(int argc, char **argv)
1010 {
1011 	int err, fd;
1012 
1013 	if (argc != 2) {
1014 		p_err("link specifier is invalid or missing\n");
1015 		return 1;
1016 	}
1017 
1018 	fd = link_parse_fd(&argc, &argv);
1019 	if (fd < 0)
1020 		return 1;
1021 
1022 	err = bpf_link_detach(fd);
1023 	if (err)
1024 		err = -errno;
1025 	close(fd);
1026 	if (err) {
1027 		p_err("failed link detach: %s", strerror(-err));
1028 		return 1;
1029 	}
1030 
1031 	if (json_output)
1032 		jsonw_null(json_wtr);
1033 
1034 	return 0;
1035 }
1036 
1037 static int do_help(int argc, char **argv)
1038 {
1039 	if (json_output) {
1040 		jsonw_null(json_wtr);
1041 		return 0;
1042 	}
1043 
1044 	fprintf(stderr,
1045 		"Usage: %1$s %2$s { show | list }   [LINK]\n"
1046 		"       %1$s %2$s pin        LINK  FILE\n"
1047 		"       %1$s %2$s detach     LINK\n"
1048 		"       %1$s %2$s help\n"
1049 		"\n"
1050 		"       " HELP_SPEC_LINK "\n"
1051 		"       " HELP_SPEC_OPTIONS " |\n"
1052 		"                    {-f|--bpffs} | {-n|--nomount} }\n"
1053 		"",
1054 		bin_name, argv[-2]);
1055 
1056 	return 0;
1057 }
1058 
1059 static const struct cmd cmds[] = {
1060 	{ "show",	do_show },
1061 	{ "list",	do_show },
1062 	{ "help",	do_help },
1063 	{ "pin",	do_pin },
1064 	{ "detach",	do_detach },
1065 	{ 0 }
1066 };
1067 
1068 int do_link(int argc, char **argv)
1069 {
1070 	return cmd_select(cmds, argc, argv, do_help);
1071 }
1072