xref: /aosp_15_r20/external/bpftool/src/link.c (revision 858ea5e570667251cdc31d3fe7b846b591105938)
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 <netinet/in.h>
7 #include <linux/netfilter.h>
8 #include <linux/netfilter_arp.h>
9 #include <linux/perf_event.h>
10 #include <net/if.h>
11 #include <stdio.h>
12 #include <unistd.h>
13 
14 #include <bpf/bpf.h>
15 #include <bpf/hashmap.h>
16 
17 #include "json_writer.h"
18 #include "main.h"
19 #include "xlated_dumper.h"
20 
21 #define PERF_HW_CACHE_LEN 128
22 
23 static struct hashmap *link_table;
24 static struct dump_data dd;
25 
26 static const char *perf_type_name[PERF_TYPE_MAX] = {
27 	[PERF_TYPE_HARDWARE]			= "hardware",
28 	[PERF_TYPE_SOFTWARE]			= "software",
29 	[PERF_TYPE_TRACEPOINT]			= "tracepoint",
30 	[PERF_TYPE_HW_CACHE]			= "hw-cache",
31 	[PERF_TYPE_RAW]				= "raw",
32 	[PERF_TYPE_BREAKPOINT]			= "breakpoint",
33 };
34 
35 const char *event_symbols_hw[PERF_COUNT_HW_MAX] = {
36 	[PERF_COUNT_HW_CPU_CYCLES]		= "cpu-cycles",
37 	[PERF_COUNT_HW_INSTRUCTIONS]		= "instructions",
38 	[PERF_COUNT_HW_CACHE_REFERENCES]	= "cache-references",
39 	[PERF_COUNT_HW_CACHE_MISSES]		= "cache-misses",
40 	[PERF_COUNT_HW_BRANCH_INSTRUCTIONS]	= "branch-instructions",
41 	[PERF_COUNT_HW_BRANCH_MISSES]		= "branch-misses",
42 	[PERF_COUNT_HW_BUS_CYCLES]		= "bus-cycles",
43 	[PERF_COUNT_HW_STALLED_CYCLES_FRONTEND]	= "stalled-cycles-frontend",
44 	[PERF_COUNT_HW_STALLED_CYCLES_BACKEND]	= "stalled-cycles-backend",
45 	[PERF_COUNT_HW_REF_CPU_CYCLES]		= "ref-cycles",
46 };
47 
48 const char *event_symbols_sw[PERF_COUNT_SW_MAX] = {
49 	[PERF_COUNT_SW_CPU_CLOCK]		= "cpu-clock",
50 	[PERF_COUNT_SW_TASK_CLOCK]		= "task-clock",
51 	[PERF_COUNT_SW_PAGE_FAULTS]		= "page-faults",
52 	[PERF_COUNT_SW_CONTEXT_SWITCHES]	= "context-switches",
53 	[PERF_COUNT_SW_CPU_MIGRATIONS]		= "cpu-migrations",
54 	[PERF_COUNT_SW_PAGE_FAULTS_MIN]		= "minor-faults",
55 	[PERF_COUNT_SW_PAGE_FAULTS_MAJ]		= "major-faults",
56 	[PERF_COUNT_SW_ALIGNMENT_FAULTS]	= "alignment-faults",
57 	[PERF_COUNT_SW_EMULATION_FAULTS]	= "emulation-faults",
58 	[PERF_COUNT_SW_DUMMY]			= "dummy",
59 	[PERF_COUNT_SW_BPF_OUTPUT]		= "bpf-output",
60 	[PERF_COUNT_SW_CGROUP_SWITCHES]		= "cgroup-switches",
61 };
62 
63 const char *evsel__hw_cache[PERF_COUNT_HW_CACHE_MAX] = {
64 	[PERF_COUNT_HW_CACHE_L1D]		= "L1-dcache",
65 	[PERF_COUNT_HW_CACHE_L1I]		= "L1-icache",
66 	[PERF_COUNT_HW_CACHE_LL]		= "LLC",
67 	[PERF_COUNT_HW_CACHE_DTLB]		= "dTLB",
68 	[PERF_COUNT_HW_CACHE_ITLB]		= "iTLB",
69 	[PERF_COUNT_HW_CACHE_BPU]		= "branch",
70 	[PERF_COUNT_HW_CACHE_NODE]		= "node",
71 };
72 
73 const char *evsel__hw_cache_op[PERF_COUNT_HW_CACHE_OP_MAX] = {
74 	[PERF_COUNT_HW_CACHE_OP_READ]		= "load",
75 	[PERF_COUNT_HW_CACHE_OP_WRITE]		= "store",
76 	[PERF_COUNT_HW_CACHE_OP_PREFETCH]	= "prefetch",
77 };
78 
79 const char *evsel__hw_cache_result[PERF_COUNT_HW_CACHE_RESULT_MAX] = {
80 	[PERF_COUNT_HW_CACHE_RESULT_ACCESS]	= "refs",
81 	[PERF_COUNT_HW_CACHE_RESULT_MISS]	= "misses",
82 };
83 
84 #define perf_event_name(array, id) ({			\
85 	const char *event_str = NULL;			\
86 							\
87 	if ((id) < ARRAY_SIZE(array))			\
88 		event_str = array[id];			\
89 	event_str;					\
90 })
91 
link_parse_fd(int * argc,char *** argv)92 static int link_parse_fd(int *argc, char ***argv)
93 {
94 	int fd;
95 
96 	if (is_prefix(**argv, "id")) {
97 		unsigned int id;
98 		char *endptr;
99 
100 		NEXT_ARGP();
101 
102 		id = strtoul(**argv, &endptr, 0);
103 		if (*endptr) {
104 			p_err("can't parse %s as ID", **argv);
105 			return -1;
106 		}
107 		NEXT_ARGP();
108 
109 		fd = bpf_link_get_fd_by_id(id);
110 		if (fd < 0)
111 			p_err("failed to get link with ID %d: %s", id, strerror(errno));
112 		return fd;
113 	} else if (is_prefix(**argv, "pinned")) {
114 		char *path;
115 
116 		NEXT_ARGP();
117 
118 		path = **argv;
119 		NEXT_ARGP();
120 
121 		return open_obj_pinned_any(path, BPF_OBJ_LINK);
122 	}
123 
124 	p_err("expected 'id' or 'pinned', got: '%s'?", **argv);
125 	return -1;
126 }
127 
128 static void
show_link_header_json(struct bpf_link_info * info,json_writer_t * wtr)129 show_link_header_json(struct bpf_link_info *info, json_writer_t *wtr)
130 {
131 	const char *link_type_str;
132 
133 	jsonw_uint_field(wtr, "id", info->id);
134 	link_type_str = libbpf_bpf_link_type_str(info->type);
135 	if (link_type_str)
136 		jsonw_string_field(wtr, "type", link_type_str);
137 	else
138 		jsonw_uint_field(wtr, "type", info->type);
139 
140 	jsonw_uint_field(json_wtr, "prog_id", info->prog_id);
141 }
142 
show_link_attach_type_json(__u32 attach_type,json_writer_t * wtr)143 static void show_link_attach_type_json(__u32 attach_type, json_writer_t *wtr)
144 {
145 	const char *attach_type_str;
146 
147 	attach_type_str = libbpf_bpf_attach_type_str(attach_type);
148 	if (attach_type_str)
149 		jsonw_string_field(wtr, "attach_type", attach_type_str);
150 	else
151 		jsonw_uint_field(wtr, "attach_type", attach_type);
152 }
153 
show_link_ifindex_json(__u32 ifindex,json_writer_t * wtr)154 static void show_link_ifindex_json(__u32 ifindex, json_writer_t *wtr)
155 {
156 	char devname[IF_NAMESIZE] = "(unknown)";
157 
158 	if (ifindex)
159 		if_indextoname(ifindex, devname);
160 	else
161 		snprintf(devname, sizeof(devname), "(detached)");
162 	jsonw_string_field(wtr, "devname", devname);
163 	jsonw_uint_field(wtr, "ifindex", ifindex);
164 }
165 
is_iter_map_target(const char * target_name)166 static bool is_iter_map_target(const char *target_name)
167 {
168 	return strcmp(target_name, "bpf_map_elem") == 0 ||
169 	       strcmp(target_name, "bpf_sk_storage_map") == 0;
170 }
171 
is_iter_cgroup_target(const char * target_name)172 static bool is_iter_cgroup_target(const char *target_name)
173 {
174 	return strcmp(target_name, "cgroup") == 0;
175 }
176 
cgroup_order_string(__u32 order)177 static const char *cgroup_order_string(__u32 order)
178 {
179 	switch (order) {
180 	case BPF_CGROUP_ITER_ORDER_UNSPEC:
181 		return "order_unspec";
182 	case BPF_CGROUP_ITER_SELF_ONLY:
183 		return "self_only";
184 	case BPF_CGROUP_ITER_DESCENDANTS_PRE:
185 		return "descendants_pre";
186 	case BPF_CGROUP_ITER_DESCENDANTS_POST:
187 		return "descendants_post";
188 	case BPF_CGROUP_ITER_ANCESTORS_UP:
189 		return "ancestors_up";
190 	default: /* won't happen */
191 		return "unknown";
192 	}
193 }
194 
is_iter_task_target(const char * target_name)195 static bool is_iter_task_target(const char *target_name)
196 {
197 	return strcmp(target_name, "task") == 0 ||
198 		strcmp(target_name, "task_file") == 0 ||
199 		strcmp(target_name, "task_vma") == 0;
200 }
201 
show_iter_json(struct bpf_link_info * info,json_writer_t * wtr)202 static void show_iter_json(struct bpf_link_info *info, json_writer_t *wtr)
203 {
204 	const char *target_name = u64_to_ptr(info->iter.target_name);
205 
206 	jsonw_string_field(wtr, "target_name", target_name);
207 
208 	if (is_iter_map_target(target_name))
209 		jsonw_uint_field(wtr, "map_id", info->iter.map.map_id);
210 	else if (is_iter_task_target(target_name)) {
211 		if (info->iter.task.tid)
212 			jsonw_uint_field(wtr, "tid", info->iter.task.tid);
213 		else if (info->iter.task.pid)
214 			jsonw_uint_field(wtr, "pid", info->iter.task.pid);
215 	}
216 
217 	if (is_iter_cgroup_target(target_name)) {
218 		jsonw_lluint_field(wtr, "cgroup_id", info->iter.cgroup.cgroup_id);
219 		jsonw_string_field(wtr, "order",
220 				   cgroup_order_string(info->iter.cgroup.order));
221 	}
222 }
223 
netfilter_dump_json(const struct bpf_link_info * info,json_writer_t * wtr)224 void netfilter_dump_json(const struct bpf_link_info *info, json_writer_t *wtr)
225 {
226 	jsonw_uint_field(json_wtr, "pf",
227 			 info->netfilter.pf);
228 	jsonw_uint_field(json_wtr, "hook",
229 			 info->netfilter.hooknum);
230 	jsonw_int_field(json_wtr, "prio",
231 			 info->netfilter.priority);
232 	jsonw_uint_field(json_wtr, "flags",
233 			 info->netfilter.flags);
234 }
235 
get_prog_info(int prog_id,struct bpf_prog_info * info)236 static int get_prog_info(int prog_id, struct bpf_prog_info *info)
237 {
238 	__u32 len = sizeof(*info);
239 	int err, prog_fd;
240 
241 	prog_fd = bpf_prog_get_fd_by_id(prog_id);
242 	if (prog_fd < 0)
243 		return prog_fd;
244 
245 	memset(info, 0, sizeof(*info));
246 	err = bpf_prog_get_info_by_fd(prog_fd, info, &len);
247 	if (err)
248 		p_err("can't get prog info: %s", strerror(errno));
249 	close(prog_fd);
250 	return err;
251 }
252 
253 struct addr_cookie {
254 	__u64 addr;
255 	__u64 cookie;
256 };
257 
cmp_addr_cookie(const void * A,const void * B)258 static int cmp_addr_cookie(const void *A, const void *B)
259 {
260 	const struct addr_cookie *a = A, *b = B;
261 
262 	if (a->addr == b->addr)
263 		return 0;
264 	return a->addr < b->addr ? -1 : 1;
265 }
266 
267 static struct addr_cookie *
get_addr_cookie_array(__u64 * addrs,__u64 * cookies,__u32 count)268 get_addr_cookie_array(__u64 *addrs, __u64 *cookies, __u32 count)
269 {
270 	struct addr_cookie *data;
271 	__u32 i;
272 
273 	data = calloc(count, sizeof(data[0]));
274 	if (!data) {
275 		p_err("mem alloc failed");
276 		return NULL;
277 	}
278 	for (i = 0; i < count; i++) {
279 		data[i].addr = addrs[i];
280 		data[i].cookie = cookies[i];
281 	}
282 	qsort(data, count, sizeof(data[0]), cmp_addr_cookie);
283 	return data;
284 }
285 
286 static void
show_kprobe_multi_json(struct bpf_link_info * info,json_writer_t * wtr)287 show_kprobe_multi_json(struct bpf_link_info *info, json_writer_t *wtr)
288 {
289 	struct addr_cookie *data;
290 	__u32 i, j = 0;
291 
292 	jsonw_bool_field(json_wtr, "retprobe",
293 			 info->kprobe_multi.flags & BPF_F_KPROBE_MULTI_RETURN);
294 	jsonw_uint_field(json_wtr, "func_cnt", info->kprobe_multi.count);
295 	jsonw_uint_field(json_wtr, "missed", info->kprobe_multi.missed);
296 	jsonw_name(json_wtr, "funcs");
297 	jsonw_start_array(json_wtr);
298 	data = get_addr_cookie_array(u64_to_ptr(info->kprobe_multi.addrs),
299 				     u64_to_ptr(info->kprobe_multi.cookies),
300 				     info->kprobe_multi.count);
301 	if (!data)
302 		return;
303 
304 	/* Load it once for all. */
305 	if (!dd.sym_count)
306 		kernel_syms_load(&dd);
307 	if (!dd.sym_count)
308 		goto error;
309 
310 	for (i = 0; i < dd.sym_count; i++) {
311 		if (dd.sym_mapping[i].address != data[j].addr)
312 			continue;
313 		jsonw_start_object(json_wtr);
314 		jsonw_uint_field(json_wtr, "addr", dd.sym_mapping[i].address);
315 		jsonw_string_field(json_wtr, "func", dd.sym_mapping[i].name);
316 		/* Print null if it is vmlinux */
317 		if (dd.sym_mapping[i].module[0] == '\0') {
318 			jsonw_name(json_wtr, "module");
319 			jsonw_null(json_wtr);
320 		} else {
321 			jsonw_string_field(json_wtr, "module", dd.sym_mapping[i].module);
322 		}
323 		jsonw_uint_field(json_wtr, "cookie", data[j].cookie);
324 		jsonw_end_object(json_wtr);
325 		if (j++ == info->kprobe_multi.count)
326 			break;
327 	}
328 	jsonw_end_array(json_wtr);
329 error:
330 	free(data);
331 }
332 
u64_to_arr(__u64 val)333 static __u64 *u64_to_arr(__u64 val)
334 {
335 	return (__u64 *) u64_to_ptr(val);
336 }
337 
338 static void
show_uprobe_multi_json(struct bpf_link_info * info,json_writer_t * wtr)339 show_uprobe_multi_json(struct bpf_link_info *info, json_writer_t *wtr)
340 {
341 	__u32 i;
342 
343 	jsonw_bool_field(json_wtr, "retprobe",
344 			 info->uprobe_multi.flags & BPF_F_UPROBE_MULTI_RETURN);
345 	jsonw_string_field(json_wtr, "path", (char *) u64_to_ptr(info->uprobe_multi.path));
346 	jsonw_uint_field(json_wtr, "func_cnt", info->uprobe_multi.count);
347 	jsonw_int_field(json_wtr, "pid", (int) info->uprobe_multi.pid);
348 	jsonw_name(json_wtr, "funcs");
349 	jsonw_start_array(json_wtr);
350 
351 	for (i = 0; i < info->uprobe_multi.count; i++) {
352 		jsonw_start_object(json_wtr);
353 		jsonw_uint_field(json_wtr, "offset",
354 				 u64_to_arr(info->uprobe_multi.offsets)[i]);
355 		jsonw_uint_field(json_wtr, "ref_ctr_offset",
356 				 u64_to_arr(info->uprobe_multi.ref_ctr_offsets)[i]);
357 		jsonw_uint_field(json_wtr, "cookie",
358 				 u64_to_arr(info->uprobe_multi.cookies)[i]);
359 		jsonw_end_object(json_wtr);
360 	}
361 	jsonw_end_array(json_wtr);
362 }
363 
364 static void
show_perf_event_kprobe_json(struct bpf_link_info * info,json_writer_t * wtr)365 show_perf_event_kprobe_json(struct bpf_link_info *info, json_writer_t *wtr)
366 {
367 	jsonw_bool_field(wtr, "retprobe", info->perf_event.type == BPF_PERF_EVENT_KRETPROBE);
368 	jsonw_uint_field(wtr, "addr", info->perf_event.kprobe.addr);
369 	jsonw_string_field(wtr, "func",
370 			   u64_to_ptr(info->perf_event.kprobe.func_name));
371 	jsonw_uint_field(wtr, "offset", info->perf_event.kprobe.offset);
372 	jsonw_uint_field(wtr, "missed", info->perf_event.kprobe.missed);
373 	jsonw_uint_field(wtr, "cookie", info->perf_event.kprobe.cookie);
374 }
375 
376 static void
show_perf_event_uprobe_json(struct bpf_link_info * info,json_writer_t * wtr)377 show_perf_event_uprobe_json(struct bpf_link_info *info, json_writer_t *wtr)
378 {
379 	jsonw_bool_field(wtr, "retprobe", info->perf_event.type == BPF_PERF_EVENT_URETPROBE);
380 	jsonw_string_field(wtr, "file",
381 			   u64_to_ptr(info->perf_event.uprobe.file_name));
382 	jsonw_uint_field(wtr, "offset", info->perf_event.uprobe.offset);
383 	jsonw_uint_field(wtr, "cookie", info->perf_event.uprobe.cookie);
384 }
385 
386 static void
show_perf_event_tracepoint_json(struct bpf_link_info * info,json_writer_t * wtr)387 show_perf_event_tracepoint_json(struct bpf_link_info *info, json_writer_t *wtr)
388 {
389 	jsonw_string_field(wtr, "tracepoint",
390 			   u64_to_ptr(info->perf_event.tracepoint.tp_name));
391 	jsonw_uint_field(wtr, "cookie", info->perf_event.tracepoint.cookie);
392 }
393 
perf_config_hw_cache_str(__u64 config)394 static char *perf_config_hw_cache_str(__u64 config)
395 {
396 	const char *hw_cache, *result, *op;
397 	char *str = malloc(PERF_HW_CACHE_LEN);
398 
399 	if (!str) {
400 		p_err("mem alloc failed");
401 		return NULL;
402 	}
403 
404 	hw_cache = perf_event_name(evsel__hw_cache, config & 0xff);
405 	if (hw_cache)
406 		snprintf(str, PERF_HW_CACHE_LEN, "%s-", hw_cache);
407 	else
408 		snprintf(str, PERF_HW_CACHE_LEN, "%lld-", config & 0xff);
409 
410 	op = perf_event_name(evsel__hw_cache_op, (config >> 8) & 0xff);
411 	if (op)
412 		snprintf(str + strlen(str), PERF_HW_CACHE_LEN - strlen(str),
413 			 "%s-", op);
414 	else
415 		snprintf(str + strlen(str), PERF_HW_CACHE_LEN - strlen(str),
416 			 "%lld-", (config >> 8) & 0xff);
417 
418 	result = perf_event_name(evsel__hw_cache_result, config >> 16);
419 	if (result)
420 		snprintf(str + strlen(str), PERF_HW_CACHE_LEN - strlen(str),
421 			 "%s", result);
422 	else
423 		snprintf(str + strlen(str), PERF_HW_CACHE_LEN - strlen(str),
424 			 "%lld", config >> 16);
425 	return str;
426 }
427 
perf_config_str(__u32 type,__u64 config)428 static const char *perf_config_str(__u32 type, __u64 config)
429 {
430 	const char *perf_config;
431 
432 	switch (type) {
433 	case PERF_TYPE_HARDWARE:
434 		perf_config = perf_event_name(event_symbols_hw, config);
435 		break;
436 	case PERF_TYPE_SOFTWARE:
437 		perf_config = perf_event_name(event_symbols_sw, config);
438 		break;
439 	case PERF_TYPE_HW_CACHE:
440 		perf_config = perf_config_hw_cache_str(config);
441 		break;
442 	default:
443 		perf_config = NULL;
444 		break;
445 	}
446 	return perf_config;
447 }
448 
449 static void
show_perf_event_event_json(struct bpf_link_info * info,json_writer_t * wtr)450 show_perf_event_event_json(struct bpf_link_info *info, json_writer_t *wtr)
451 {
452 	__u64 config = info->perf_event.event.config;
453 	__u32 type = info->perf_event.event.type;
454 	const char *perf_type, *perf_config;
455 
456 	perf_type = perf_event_name(perf_type_name, type);
457 	if (perf_type)
458 		jsonw_string_field(wtr, "event_type", perf_type);
459 	else
460 		jsonw_uint_field(wtr, "event_type", type);
461 
462 	perf_config = perf_config_str(type, config);
463 	if (perf_config)
464 		jsonw_string_field(wtr, "event_config", perf_config);
465 	else
466 		jsonw_uint_field(wtr, "event_config", config);
467 
468 	jsonw_uint_field(wtr, "cookie", info->perf_event.event.cookie);
469 
470 	if (type == PERF_TYPE_HW_CACHE && perf_config)
471 		free((void *)perf_config);
472 }
473 
show_link_close_json(int fd,struct bpf_link_info * info)474 static int show_link_close_json(int fd, struct bpf_link_info *info)
475 {
476 	struct bpf_prog_info prog_info;
477 	const char *prog_type_str;
478 	int err;
479 
480 	jsonw_start_object(json_wtr);
481 
482 	show_link_header_json(info, json_wtr);
483 
484 	switch (info->type) {
485 	case BPF_LINK_TYPE_RAW_TRACEPOINT:
486 		jsonw_string_field(json_wtr, "tp_name",
487 				   u64_to_ptr(info->raw_tracepoint.tp_name));
488 		break;
489 	case BPF_LINK_TYPE_TRACING:
490 		err = get_prog_info(info->prog_id, &prog_info);
491 		if (err)
492 			return err;
493 
494 		prog_type_str = libbpf_bpf_prog_type_str(prog_info.type);
495 		/* libbpf will return NULL for variants unknown to it. */
496 		if (prog_type_str)
497 			jsonw_string_field(json_wtr, "prog_type", prog_type_str);
498 		else
499 			jsonw_uint_field(json_wtr, "prog_type", prog_info.type);
500 
501 		show_link_attach_type_json(info->tracing.attach_type,
502 					   json_wtr);
503 		jsonw_uint_field(json_wtr, "target_obj_id", info->tracing.target_obj_id);
504 		jsonw_uint_field(json_wtr, "target_btf_id", info->tracing.target_btf_id);
505 		break;
506 	case BPF_LINK_TYPE_CGROUP:
507 		jsonw_lluint_field(json_wtr, "cgroup_id",
508 				   info->cgroup.cgroup_id);
509 		show_link_attach_type_json(info->cgroup.attach_type, json_wtr);
510 		break;
511 	case BPF_LINK_TYPE_ITER:
512 		show_iter_json(info, json_wtr);
513 		break;
514 	case BPF_LINK_TYPE_NETNS:
515 		jsonw_uint_field(json_wtr, "netns_ino",
516 				 info->netns.netns_ino);
517 		show_link_attach_type_json(info->netns.attach_type, json_wtr);
518 		break;
519 	case BPF_LINK_TYPE_NETFILTER:
520 		netfilter_dump_json(info, json_wtr);
521 		break;
522 	case BPF_LINK_TYPE_TCX:
523 		show_link_ifindex_json(info->tcx.ifindex, json_wtr);
524 		show_link_attach_type_json(info->tcx.attach_type, json_wtr);
525 		break;
526 	case BPF_LINK_TYPE_NETKIT:
527 		show_link_ifindex_json(info->netkit.ifindex, json_wtr);
528 		show_link_attach_type_json(info->netkit.attach_type, json_wtr);
529 		break;
530 	case BPF_LINK_TYPE_XDP:
531 		show_link_ifindex_json(info->xdp.ifindex, json_wtr);
532 		break;
533 	case BPF_LINK_TYPE_STRUCT_OPS:
534 		jsonw_uint_field(json_wtr, "map_id",
535 				 info->struct_ops.map_id);
536 		break;
537 	case BPF_LINK_TYPE_KPROBE_MULTI:
538 		show_kprobe_multi_json(info, json_wtr);
539 		break;
540 	case BPF_LINK_TYPE_UPROBE_MULTI:
541 		show_uprobe_multi_json(info, json_wtr);
542 		break;
543 	case BPF_LINK_TYPE_PERF_EVENT:
544 		switch (info->perf_event.type) {
545 		case BPF_PERF_EVENT_EVENT:
546 			show_perf_event_event_json(info, json_wtr);
547 			break;
548 		case BPF_PERF_EVENT_TRACEPOINT:
549 			show_perf_event_tracepoint_json(info, json_wtr);
550 			break;
551 		case BPF_PERF_EVENT_KPROBE:
552 		case BPF_PERF_EVENT_KRETPROBE:
553 			show_perf_event_kprobe_json(info, json_wtr);
554 			break;
555 		case BPF_PERF_EVENT_UPROBE:
556 		case BPF_PERF_EVENT_URETPROBE:
557 			show_perf_event_uprobe_json(info, json_wtr);
558 			break;
559 		default:
560 			break;
561 		}
562 		break;
563 	default:
564 		break;
565 	}
566 
567 	if (!hashmap__empty(link_table)) {
568 		struct hashmap_entry *entry;
569 
570 		jsonw_name(json_wtr, "pinned");
571 		jsonw_start_array(json_wtr);
572 		hashmap__for_each_key_entry(link_table, entry, info->id)
573 			jsonw_string(json_wtr, entry->pvalue);
574 		jsonw_end_array(json_wtr);
575 	}
576 
577 	emit_obj_refs_json(refs_table, info->id, json_wtr);
578 
579 	jsonw_end_object(json_wtr);
580 
581 	return 0;
582 }
583 
show_link_header_plain(struct bpf_link_info * info)584 static void show_link_header_plain(struct bpf_link_info *info)
585 {
586 	const char *link_type_str;
587 
588 	printf("%u: ", info->id);
589 	link_type_str = libbpf_bpf_link_type_str(info->type);
590 	if (link_type_str)
591 		printf("%s  ", link_type_str);
592 	else
593 		printf("type %u  ", info->type);
594 
595 	if (info->type == BPF_LINK_TYPE_STRUCT_OPS)
596 		printf("map %u  ", info->struct_ops.map_id);
597 	else
598 		printf("prog %u  ", info->prog_id);
599 }
600 
show_link_attach_type_plain(__u32 attach_type)601 static void show_link_attach_type_plain(__u32 attach_type)
602 {
603 	const char *attach_type_str;
604 
605 	attach_type_str = libbpf_bpf_attach_type_str(attach_type);
606 	if (attach_type_str)
607 		printf("attach_type %s  ", attach_type_str);
608 	else
609 		printf("attach_type %u  ", attach_type);
610 }
611 
show_link_ifindex_plain(__u32 ifindex)612 static void show_link_ifindex_plain(__u32 ifindex)
613 {
614 	char devname[IF_NAMESIZE * 2] = "(unknown)";
615 	char tmpname[IF_NAMESIZE];
616 	char *ret = NULL;
617 
618 	if (ifindex)
619 		ret = if_indextoname(ifindex, tmpname);
620 	else
621 		snprintf(devname, sizeof(devname), "(detached)");
622 	if (ret)
623 		snprintf(devname, sizeof(devname), "%s(%d)",
624 			 tmpname, ifindex);
625 	printf("ifindex %s  ", devname);
626 }
627 
show_iter_plain(struct bpf_link_info * info)628 static void show_iter_plain(struct bpf_link_info *info)
629 {
630 	const char *target_name = u64_to_ptr(info->iter.target_name);
631 
632 	printf("target_name %s  ", target_name);
633 
634 	if (is_iter_map_target(target_name))
635 		printf("map_id %u  ", info->iter.map.map_id);
636 	else if (is_iter_task_target(target_name)) {
637 		if (info->iter.task.tid)
638 			printf("tid %u ", info->iter.task.tid);
639 		else if (info->iter.task.pid)
640 			printf("pid %u ", info->iter.task.pid);
641 	}
642 
643 	if (is_iter_cgroup_target(target_name)) {
644 		printf("cgroup_id %llu  ", info->iter.cgroup.cgroup_id);
645 		printf("order %s  ",
646 		       cgroup_order_string(info->iter.cgroup.order));
647 	}
648 }
649 
650 static const char * const pf2name[] = {
651 	[NFPROTO_INET] = "inet",
652 	[NFPROTO_IPV4] = "ip",
653 	[NFPROTO_ARP] = "arp",
654 	[NFPROTO_NETDEV] = "netdev",
655 	[NFPROTO_BRIDGE] = "bridge",
656 	[NFPROTO_IPV6] = "ip6",
657 };
658 
659 static const char * const inethook2name[] = {
660 	[NF_INET_PRE_ROUTING] = "prerouting",
661 	[NF_INET_LOCAL_IN] = "input",
662 	[NF_INET_FORWARD] = "forward",
663 	[NF_INET_LOCAL_OUT] = "output",
664 	[NF_INET_POST_ROUTING] = "postrouting",
665 };
666 
667 static const char * const arphook2name[] = {
668 	[NF_ARP_IN] = "input",
669 	[NF_ARP_OUT] = "output",
670 };
671 
netfilter_dump_plain(const struct bpf_link_info * info)672 void netfilter_dump_plain(const struct bpf_link_info *info)
673 {
674 	const char *hookname = NULL, *pfname = NULL;
675 	unsigned int hook = info->netfilter.hooknum;
676 	unsigned int pf = info->netfilter.pf;
677 
678 	if (pf < ARRAY_SIZE(pf2name))
679 		pfname = pf2name[pf];
680 
681 	switch (pf) {
682 	case NFPROTO_BRIDGE: /* bridge shares numbers with enum nf_inet_hooks */
683 	case NFPROTO_IPV4:
684 	case NFPROTO_IPV6:
685 	case NFPROTO_INET:
686 		if (hook < ARRAY_SIZE(inethook2name))
687 			hookname = inethook2name[hook];
688 		break;
689 	case NFPROTO_ARP:
690 		if (hook < ARRAY_SIZE(arphook2name))
691 			hookname = arphook2name[hook];
692 	default:
693 		break;
694 	}
695 
696 	if (pfname)
697 		printf("\n\t%s", pfname);
698 	else
699 		printf("\n\tpf: %d", pf);
700 
701 	if (hookname)
702 		printf(" %s", hookname);
703 	else
704 		printf(", hook %u,", hook);
705 
706 	printf(" prio %d", info->netfilter.priority);
707 
708 	if (info->netfilter.flags)
709 		printf(" flags 0x%x", info->netfilter.flags);
710 }
711 
show_kprobe_multi_plain(struct bpf_link_info * info)712 static void show_kprobe_multi_plain(struct bpf_link_info *info)
713 {
714 	struct addr_cookie *data;
715 	__u32 i, j = 0;
716 
717 	if (!info->kprobe_multi.count)
718 		return;
719 
720 	if (info->kprobe_multi.flags & BPF_F_KPROBE_MULTI_RETURN)
721 		printf("\n\tkretprobe.multi  ");
722 	else
723 		printf("\n\tkprobe.multi  ");
724 	printf("func_cnt %u  ", info->kprobe_multi.count);
725 	if (info->kprobe_multi.missed)
726 		printf("missed %llu  ", info->kprobe_multi.missed);
727 	data = get_addr_cookie_array(u64_to_ptr(info->kprobe_multi.addrs),
728 				     u64_to_ptr(info->kprobe_multi.cookies),
729 				     info->kprobe_multi.count);
730 	if (!data)
731 		return;
732 
733 	/* Load it once for all. */
734 	if (!dd.sym_count)
735 		kernel_syms_load(&dd);
736 	if (!dd.sym_count)
737 		goto error;
738 
739 	printf("\n\t%-16s %-16s %s", "addr", "cookie", "func [module]");
740 	for (i = 0; i < dd.sym_count; i++) {
741 		if (dd.sym_mapping[i].address != data[j].addr)
742 			continue;
743 		printf("\n\t%016lx %-16llx %s",
744 		       dd.sym_mapping[i].address, data[j].cookie, dd.sym_mapping[i].name);
745 		if (dd.sym_mapping[i].module[0] != '\0')
746 			printf(" [%s]  ", dd.sym_mapping[i].module);
747 		else
748 			printf("  ");
749 
750 		if (j++ == info->kprobe_multi.count)
751 			break;
752 	}
753 error:
754 	free(data);
755 }
756 
show_uprobe_multi_plain(struct bpf_link_info * info)757 static void show_uprobe_multi_plain(struct bpf_link_info *info)
758 {
759 	__u32 i;
760 
761 	if (!info->uprobe_multi.count)
762 		return;
763 
764 	if (info->uprobe_multi.flags & BPF_F_UPROBE_MULTI_RETURN)
765 		printf("\n\turetprobe.multi  ");
766 	else
767 		printf("\n\tuprobe.multi  ");
768 
769 	printf("path %s  ", (char *) u64_to_ptr(info->uprobe_multi.path));
770 	printf("func_cnt %u  ", info->uprobe_multi.count);
771 
772 	if (info->uprobe_multi.pid)
773 		printf("pid %d  ", info->uprobe_multi.pid);
774 
775 	printf("\n\t%-16s   %-16s   %-16s", "offset", "ref_ctr_offset", "cookies");
776 	for (i = 0; i < info->uprobe_multi.count; i++) {
777 		printf("\n\t0x%-16llx 0x%-16llx 0x%-16llx",
778 			u64_to_arr(info->uprobe_multi.offsets)[i],
779 			u64_to_arr(info->uprobe_multi.ref_ctr_offsets)[i],
780 			u64_to_arr(info->uprobe_multi.cookies)[i]);
781 	}
782 }
783 
show_perf_event_kprobe_plain(struct bpf_link_info * info)784 static void show_perf_event_kprobe_plain(struct bpf_link_info *info)
785 {
786 	const char *buf;
787 
788 	buf = u64_to_ptr(info->perf_event.kprobe.func_name);
789 	if (buf[0] == '\0' && !info->perf_event.kprobe.addr)
790 		return;
791 
792 	if (info->perf_event.type == BPF_PERF_EVENT_KRETPROBE)
793 		printf("\n\tkretprobe ");
794 	else
795 		printf("\n\tkprobe ");
796 	if (info->perf_event.kprobe.addr)
797 		printf("%llx ", info->perf_event.kprobe.addr);
798 	printf("%s", buf);
799 	if (info->perf_event.kprobe.offset)
800 		printf("+%#x", info->perf_event.kprobe.offset);
801 	if (info->perf_event.kprobe.missed)
802 		printf("  missed %llu", info->perf_event.kprobe.missed);
803 	if (info->perf_event.kprobe.cookie)
804 		printf("  cookie %llu", info->perf_event.kprobe.cookie);
805 	printf("  ");
806 }
807 
show_perf_event_uprobe_plain(struct bpf_link_info * info)808 static void show_perf_event_uprobe_plain(struct bpf_link_info *info)
809 {
810 	const char *buf;
811 
812 	buf = u64_to_ptr(info->perf_event.uprobe.file_name);
813 	if (buf[0] == '\0')
814 		return;
815 
816 	if (info->perf_event.type == BPF_PERF_EVENT_URETPROBE)
817 		printf("\n\turetprobe ");
818 	else
819 		printf("\n\tuprobe ");
820 	printf("%s+%#x  ", buf, info->perf_event.uprobe.offset);
821 	if (info->perf_event.uprobe.cookie)
822 		printf("cookie %llu  ", info->perf_event.uprobe.cookie);
823 }
824 
show_perf_event_tracepoint_plain(struct bpf_link_info * info)825 static void show_perf_event_tracepoint_plain(struct bpf_link_info *info)
826 {
827 	const char *buf;
828 
829 	buf = u64_to_ptr(info->perf_event.tracepoint.tp_name);
830 	if (buf[0] == '\0')
831 		return;
832 
833 	printf("\n\ttracepoint %s  ", buf);
834 	if (info->perf_event.tracepoint.cookie)
835 		printf("cookie %llu  ", info->perf_event.tracepoint.cookie);
836 }
837 
show_perf_event_event_plain(struct bpf_link_info * info)838 static void show_perf_event_event_plain(struct bpf_link_info *info)
839 {
840 	__u64 config = info->perf_event.event.config;
841 	__u32 type = info->perf_event.event.type;
842 	const char *perf_type, *perf_config;
843 
844 	printf("\n\tevent ");
845 	perf_type = perf_event_name(perf_type_name, type);
846 	if (perf_type)
847 		printf("%s:", perf_type);
848 	else
849 		printf("%u :", type);
850 
851 	perf_config = perf_config_str(type, config);
852 	if (perf_config)
853 		printf("%s  ", perf_config);
854 	else
855 		printf("%llu  ", config);
856 
857 	if (info->perf_event.event.cookie)
858 		printf("cookie %llu  ", info->perf_event.event.cookie);
859 
860 	if (type == PERF_TYPE_HW_CACHE && perf_config)
861 		free((void *)perf_config);
862 }
863 
show_link_close_plain(int fd,struct bpf_link_info * info)864 static int show_link_close_plain(int fd, struct bpf_link_info *info)
865 {
866 	struct bpf_prog_info prog_info;
867 	const char *prog_type_str;
868 	int err;
869 
870 	show_link_header_plain(info);
871 
872 	switch (info->type) {
873 	case BPF_LINK_TYPE_RAW_TRACEPOINT:
874 		printf("\n\ttp '%s'  ",
875 		       (const char *)u64_to_ptr(info->raw_tracepoint.tp_name));
876 		break;
877 	case BPF_LINK_TYPE_TRACING:
878 		err = get_prog_info(info->prog_id, &prog_info);
879 		if (err)
880 			return err;
881 
882 		prog_type_str = libbpf_bpf_prog_type_str(prog_info.type);
883 		/* libbpf will return NULL for variants unknown to it. */
884 		if (prog_type_str)
885 			printf("\n\tprog_type %s  ", prog_type_str);
886 		else
887 			printf("\n\tprog_type %u  ", prog_info.type);
888 
889 		show_link_attach_type_plain(info->tracing.attach_type);
890 		if (info->tracing.target_obj_id || info->tracing.target_btf_id)
891 			printf("\n\ttarget_obj_id %u  target_btf_id %u  ",
892 			       info->tracing.target_obj_id,
893 			       info->tracing.target_btf_id);
894 		break;
895 	case BPF_LINK_TYPE_CGROUP:
896 		printf("\n\tcgroup_id %zu  ", (size_t)info->cgroup.cgroup_id);
897 		show_link_attach_type_plain(info->cgroup.attach_type);
898 		break;
899 	case BPF_LINK_TYPE_ITER:
900 		show_iter_plain(info);
901 		break;
902 	case BPF_LINK_TYPE_NETNS:
903 		printf("\n\tnetns_ino %u  ", info->netns.netns_ino);
904 		show_link_attach_type_plain(info->netns.attach_type);
905 		break;
906 	case BPF_LINK_TYPE_NETFILTER:
907 		netfilter_dump_plain(info);
908 		break;
909 	case BPF_LINK_TYPE_TCX:
910 		printf("\n\t");
911 		show_link_ifindex_plain(info->tcx.ifindex);
912 		show_link_attach_type_plain(info->tcx.attach_type);
913 		break;
914 	case BPF_LINK_TYPE_NETKIT:
915 		printf("\n\t");
916 		show_link_ifindex_plain(info->netkit.ifindex);
917 		show_link_attach_type_plain(info->netkit.attach_type);
918 		break;
919 	case BPF_LINK_TYPE_XDP:
920 		printf("\n\t");
921 		show_link_ifindex_plain(info->xdp.ifindex);
922 		break;
923 	case BPF_LINK_TYPE_KPROBE_MULTI:
924 		show_kprobe_multi_plain(info);
925 		break;
926 	case BPF_LINK_TYPE_UPROBE_MULTI:
927 		show_uprobe_multi_plain(info);
928 		break;
929 	case BPF_LINK_TYPE_PERF_EVENT:
930 		switch (info->perf_event.type) {
931 		case BPF_PERF_EVENT_EVENT:
932 			show_perf_event_event_plain(info);
933 			break;
934 		case BPF_PERF_EVENT_TRACEPOINT:
935 			show_perf_event_tracepoint_plain(info);
936 			break;
937 		case BPF_PERF_EVENT_KPROBE:
938 		case BPF_PERF_EVENT_KRETPROBE:
939 			show_perf_event_kprobe_plain(info);
940 			break;
941 		case BPF_PERF_EVENT_UPROBE:
942 		case BPF_PERF_EVENT_URETPROBE:
943 			show_perf_event_uprobe_plain(info);
944 			break;
945 		default:
946 			break;
947 		}
948 		break;
949 	default:
950 		break;
951 	}
952 
953 	if (!hashmap__empty(link_table)) {
954 		struct hashmap_entry *entry;
955 
956 		hashmap__for_each_key_entry(link_table, entry, info->id)
957 			printf("\n\tpinned %s", (char *)entry->pvalue);
958 	}
959 	emit_obj_refs_plain(refs_table, info->id, "\n\tpids ");
960 
961 	printf("\n");
962 
963 	return 0;
964 }
965 
do_show_link(int fd)966 static int do_show_link(int fd)
967 {
968 	__u64 *ref_ctr_offsets = NULL, *offsets = NULL, *cookies = NULL;
969 	struct bpf_link_info info;
970 	__u32 len = sizeof(info);
971 	char path_buf[PATH_MAX];
972 	__u64 *addrs = NULL;
973 	char buf[PATH_MAX];
974 	int count;
975 	int err;
976 
977 	memset(&info, 0, sizeof(info));
978 	buf[0] = '\0';
979 again:
980 	err = bpf_link_get_info_by_fd(fd, &info, &len);
981 	if (err) {
982 		p_err("can't get link info: %s",
983 		      strerror(errno));
984 		close(fd);
985 		return err;
986 	}
987 	if (info.type == BPF_LINK_TYPE_RAW_TRACEPOINT &&
988 	    !info.raw_tracepoint.tp_name) {
989 		info.raw_tracepoint.tp_name = ptr_to_u64(&buf);
990 		info.raw_tracepoint.tp_name_len = sizeof(buf);
991 		goto again;
992 	}
993 	if (info.type == BPF_LINK_TYPE_ITER &&
994 	    !info.iter.target_name) {
995 		info.iter.target_name = ptr_to_u64(&buf);
996 		info.iter.target_name_len = sizeof(buf);
997 		goto again;
998 	}
999 	if (info.type == BPF_LINK_TYPE_KPROBE_MULTI &&
1000 	    !info.kprobe_multi.addrs) {
1001 		count = info.kprobe_multi.count;
1002 		if (count) {
1003 			addrs = calloc(count, sizeof(__u64));
1004 			if (!addrs) {
1005 				p_err("mem alloc failed");
1006 				close(fd);
1007 				return -ENOMEM;
1008 			}
1009 			info.kprobe_multi.addrs = ptr_to_u64(addrs);
1010 			cookies = calloc(count, sizeof(__u64));
1011 			if (!cookies) {
1012 				p_err("mem alloc failed");
1013 				free(addrs);
1014 				close(fd);
1015 				return -ENOMEM;
1016 			}
1017 			info.kprobe_multi.cookies = ptr_to_u64(cookies);
1018 			goto again;
1019 		}
1020 	}
1021 	if (info.type == BPF_LINK_TYPE_UPROBE_MULTI &&
1022 	    !info.uprobe_multi.offsets) {
1023 		count = info.uprobe_multi.count;
1024 		if (count) {
1025 			offsets = calloc(count, sizeof(__u64));
1026 			if (!offsets) {
1027 				p_err("mem alloc failed");
1028 				close(fd);
1029 				return -ENOMEM;
1030 			}
1031 			info.uprobe_multi.offsets = ptr_to_u64(offsets);
1032 			ref_ctr_offsets = calloc(count, sizeof(__u64));
1033 			if (!ref_ctr_offsets) {
1034 				p_err("mem alloc failed");
1035 				free(offsets);
1036 				close(fd);
1037 				return -ENOMEM;
1038 			}
1039 			info.uprobe_multi.ref_ctr_offsets = ptr_to_u64(ref_ctr_offsets);
1040 			cookies = calloc(count, sizeof(__u64));
1041 			if (!cookies) {
1042 				p_err("mem alloc failed");
1043 				free(ref_ctr_offsets);
1044 				free(offsets);
1045 				close(fd);
1046 				return -ENOMEM;
1047 			}
1048 			info.uprobe_multi.cookies = ptr_to_u64(cookies);
1049 			info.uprobe_multi.path = ptr_to_u64(path_buf);
1050 			info.uprobe_multi.path_size = sizeof(path_buf);
1051 			goto again;
1052 		}
1053 	}
1054 	if (info.type == BPF_LINK_TYPE_PERF_EVENT) {
1055 		switch (info.perf_event.type) {
1056 		case BPF_PERF_EVENT_TRACEPOINT:
1057 			if (!info.perf_event.tracepoint.tp_name) {
1058 				info.perf_event.tracepoint.tp_name = ptr_to_u64(&buf);
1059 				info.perf_event.tracepoint.name_len = sizeof(buf);
1060 				goto again;
1061 			}
1062 			break;
1063 		case BPF_PERF_EVENT_KPROBE:
1064 		case BPF_PERF_EVENT_KRETPROBE:
1065 			if (!info.perf_event.kprobe.func_name) {
1066 				info.perf_event.kprobe.func_name = ptr_to_u64(&buf);
1067 				info.perf_event.kprobe.name_len = sizeof(buf);
1068 				goto again;
1069 			}
1070 			break;
1071 		case BPF_PERF_EVENT_UPROBE:
1072 		case BPF_PERF_EVENT_URETPROBE:
1073 			if (!info.perf_event.uprobe.file_name) {
1074 				info.perf_event.uprobe.file_name = ptr_to_u64(&buf);
1075 				info.perf_event.uprobe.name_len = sizeof(buf);
1076 				goto again;
1077 			}
1078 			break;
1079 		default:
1080 			break;
1081 		}
1082 	}
1083 
1084 	if (json_output)
1085 		show_link_close_json(fd, &info);
1086 	else
1087 		show_link_close_plain(fd, &info);
1088 
1089 	free(ref_ctr_offsets);
1090 	free(cookies);
1091 	free(offsets);
1092 	free(addrs);
1093 	close(fd);
1094 	return 0;
1095 }
1096 
do_show(int argc,char ** argv)1097 static int do_show(int argc, char **argv)
1098 {
1099 	__u32 id = 0;
1100 	int err, fd;
1101 
1102 	if (show_pinned) {
1103 		link_table = hashmap__new(hash_fn_for_key_as_id,
1104 					  equal_fn_for_key_as_id, NULL);
1105 		if (IS_ERR(link_table)) {
1106 			p_err("failed to create hashmap for pinned paths");
1107 			return -1;
1108 		}
1109 		build_pinned_obj_table(link_table, BPF_OBJ_LINK);
1110 	}
1111 	build_obj_refs_table(&refs_table, BPF_OBJ_LINK);
1112 
1113 	if (argc == 2) {
1114 		fd = link_parse_fd(&argc, &argv);
1115 		if (fd < 0)
1116 			return fd;
1117 		do_show_link(fd);
1118 		goto out;
1119 	}
1120 
1121 	if (argc)
1122 		return BAD_ARG();
1123 
1124 	if (json_output)
1125 		jsonw_start_array(json_wtr);
1126 	while (true) {
1127 		err = bpf_link_get_next_id(id, &id);
1128 		if (err) {
1129 			if (errno == ENOENT)
1130 				break;
1131 			p_err("can't get next link: %s%s", strerror(errno),
1132 			      errno == EINVAL ? " -- kernel too old?" : "");
1133 			break;
1134 		}
1135 
1136 		fd = bpf_link_get_fd_by_id(id);
1137 		if (fd < 0) {
1138 			if (errno == ENOENT)
1139 				continue;
1140 			p_err("can't get link by id (%u): %s",
1141 			      id, strerror(errno));
1142 			break;
1143 		}
1144 
1145 		err = do_show_link(fd);
1146 		if (err)
1147 			break;
1148 	}
1149 	if (json_output)
1150 		jsonw_end_array(json_wtr);
1151 
1152 	delete_obj_refs_table(refs_table);
1153 
1154 	if (show_pinned)
1155 		delete_pinned_obj_table(link_table);
1156 
1157 out:
1158 	if (dd.sym_count)
1159 		kernel_syms_destroy(&dd);
1160 	return errno == ENOENT ? 0 : -1;
1161 }
1162 
do_pin(int argc,char ** argv)1163 static int do_pin(int argc, char **argv)
1164 {
1165 	int err;
1166 
1167 	err = do_pin_any(argc, argv, link_parse_fd);
1168 	if (!err && json_output)
1169 		jsonw_null(json_wtr);
1170 	return err;
1171 }
1172 
do_detach(int argc,char ** argv)1173 static int do_detach(int argc, char **argv)
1174 {
1175 	int err, fd;
1176 
1177 	if (argc != 2) {
1178 		p_err("link specifier is invalid or missing\n");
1179 		return 1;
1180 	}
1181 
1182 	fd = link_parse_fd(&argc, &argv);
1183 	if (fd < 0)
1184 		return 1;
1185 
1186 	err = bpf_link_detach(fd);
1187 	if (err)
1188 		err = -errno;
1189 	close(fd);
1190 	if (err) {
1191 		p_err("failed link detach: %s", strerror(-err));
1192 		return 1;
1193 	}
1194 
1195 	if (json_output)
1196 		jsonw_null(json_wtr);
1197 
1198 	return 0;
1199 }
1200 
do_help(int argc,char ** argv)1201 static int do_help(int argc, char **argv)
1202 {
1203 	if (json_output) {
1204 		jsonw_null(json_wtr);
1205 		return 0;
1206 	}
1207 
1208 	fprintf(stderr,
1209 		"Usage: %1$s %2$s { show | list }   [LINK]\n"
1210 		"       %1$s %2$s pin        LINK  FILE\n"
1211 		"       %1$s %2$s detach     LINK\n"
1212 		"       %1$s %2$s help\n"
1213 		"\n"
1214 		"       " HELP_SPEC_LINK "\n"
1215 		"       " HELP_SPEC_OPTIONS " |\n"
1216 		"                    {-f|--bpffs} | {-n|--nomount} }\n"
1217 		"",
1218 		bin_name, argv[-2]);
1219 
1220 	return 0;
1221 }
1222 
1223 static const struct cmd cmds[] = {
1224 	{ "show",	do_show },
1225 	{ "list",	do_show },
1226 	{ "help",	do_help },
1227 	{ "pin",	do_pin },
1228 	{ "detach",	do_detach },
1229 	{ 0 }
1230 };
1231 
do_link(int argc,char ** argv)1232 int do_link(int argc, char **argv)
1233 {
1234 	return cmd_select(cmds, argc, argv, do_help);
1235 }
1236