1// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
2
3/*
4 * common eBPF ELF operations.
5 *
6 * Copyright (C) 2013-2015 Alexei Starovoitov <ast@kernel.org>
7 * Copyright (C) 2015 Wang Nan <wangnan0@huawei.com>
8 * Copyright (C) 2015 Huawei Inc.
9 *
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU Lesser General Public
12 * License as published by the Free Software Foundation;
13 * version 2.1 of the License (not later!)
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18 * GNU Lesser General Public License for more details.
19 *
20 * You should have received a copy of the GNU Lesser General Public
21 * License along with this program; if not,  see <http://www.gnu.org/licenses>
22 */
23
24#include <stdlib.h>
25#include <string.h>
26#include <memory.h>
27#include <unistd.h>
28#include <asm/unistd.h>
29#include <errno.h>
30#include <linux/bpf.h>
31#include <linux/filter.h>
32#include <linux/kernel.h>
33#include <limits.h>
34#include <sys/resource.h>
35#include "bpf.h"
36#include "libbpf.h"
37#include "libbpf_internal.h"
38
39/*
40 * When building perf, unistd.h is overridden. __NR_bpf is
41 * required to be defined explicitly.
42 */
43#ifndef __NR_bpf
44# if defined(__i386__)
45#  define __NR_bpf 357
46# elif defined(__x86_64__)
47#  define __NR_bpf 321
48# elif defined(__aarch64__)
49#  define __NR_bpf 280
50# elif defined(__sparc__)
51#  define __NR_bpf 349
52# elif defined(__s390__)
53#  define __NR_bpf 351
54# elif defined(__arc__)
55#  define __NR_bpf 280
56# elif defined(__mips__) && defined(_ABIO32)
57#  define __NR_bpf 4355
58# elif defined(__mips__) && defined(_ABIN32)
59#  define __NR_bpf 6319
60# elif defined(__mips__) && defined(_ABI64)
61#  define __NR_bpf 5315
62# else
63#  error __NR_bpf not defined. libbpf does not support your arch.
64# endif
65#endif
66
67static inline __u64 ptr_to_u64(const void *ptr)
68{
69	return (__u64) (unsigned long) ptr;
70}
71
72static inline int sys_bpf(enum bpf_cmd cmd, union bpf_attr *attr,
73			  unsigned int size)
74{
75	return syscall(__NR_bpf, cmd, attr, size);
76}
77
78static inline int sys_bpf_fd(enum bpf_cmd cmd, union bpf_attr *attr,
79			     unsigned int size)
80{
81	int fd;
82
83	fd = sys_bpf(cmd, attr, size);
84	return ensure_good_fd(fd);
85}
86
87int sys_bpf_prog_load(union bpf_attr *attr, unsigned int size, int attempts)
88{
89	int fd;
90
91	do {
92		fd = sys_bpf_fd(BPF_PROG_LOAD, attr, size);
93	} while (fd < 0 && errno == EAGAIN && --attempts > 0);
94
95	return fd;
96}
97
98/* Probe whether kernel switched from memlock-based (RLIMIT_MEMLOCK) to
99 * memcg-based memory accounting for BPF maps and progs. This was done in [0].
100 * We use the support for bpf_ktime_get_coarse_ns() helper, which was added in
101 * the same 5.11 Linux release ([1]), to detect memcg-based accounting for BPF.
102 *
103 *   [0] https://lore.kernel.org/bpf/20201201215900.3569844-1-guro@fb.com/
104 *   [1] d05512618056 ("bpf: Add bpf_ktime_get_coarse_ns helper")
105 */
106int probe_memcg_account(void)
107{
108	const size_t attr_sz = offsetofend(union bpf_attr, attach_btf_obj_fd);
109	struct bpf_insn insns[] = {
110		BPF_EMIT_CALL(BPF_FUNC_ktime_get_coarse_ns),
111		BPF_EXIT_INSN(),
112	};
113	size_t insn_cnt = ARRAY_SIZE(insns);
114	union bpf_attr attr;
115	int prog_fd;
116
117	/* attempt loading freplace trying to use custom BTF */
118	memset(&attr, 0, attr_sz);
119	attr.prog_type = BPF_PROG_TYPE_SOCKET_FILTER;
120	attr.insns = ptr_to_u64(insns);
121	attr.insn_cnt = insn_cnt;
122	attr.license = ptr_to_u64("GPL");
123
124	prog_fd = sys_bpf_fd(BPF_PROG_LOAD, &attr, attr_sz);
125	if (prog_fd >= 0) {
126		close(prog_fd);
127		return 1;
128	}
129	return 0;
130}
131
132static bool memlock_bumped;
133static rlim_t memlock_rlim = RLIM_INFINITY;
134
135int libbpf_set_memlock_rlim(size_t memlock_bytes)
136{
137	if (memlock_bumped)
138		return libbpf_err(-EBUSY);
139
140	memlock_rlim = memlock_bytes;
141	return 0;
142}
143
144int bump_rlimit_memlock(void)
145{
146	struct rlimit rlim;
147
148	/* if kernel supports memcg-based accounting, skip bumping RLIMIT_MEMLOCK */
149	if (memlock_bumped || kernel_supports(NULL, FEAT_MEMCG_ACCOUNT))
150		return 0;
151
152	memlock_bumped = true;
153
154	/* zero memlock_rlim_max disables auto-bumping RLIMIT_MEMLOCK */
155	if (memlock_rlim == 0)
156		return 0;
157
158	rlim.rlim_cur = rlim.rlim_max = memlock_rlim;
159	if (setrlimit(RLIMIT_MEMLOCK, &rlim))
160		return -errno;
161
162	return 0;
163}
164
165int bpf_map_create(enum bpf_map_type map_type,
166		   const char *map_name,
167		   __u32 key_size,
168		   __u32 value_size,
169		   __u32 max_entries,
170		   const struct bpf_map_create_opts *opts)
171{
172	const size_t attr_sz = offsetofend(union bpf_attr, map_extra);
173	union bpf_attr attr;
174	int fd;
175
176	bump_rlimit_memlock();
177
178	memset(&attr, 0, attr_sz);
179
180	if (!OPTS_VALID(opts, bpf_map_create_opts))
181		return libbpf_err(-EINVAL);
182
183	attr.map_type = map_type;
184	if (map_name && kernel_supports(NULL, FEAT_PROG_NAME))
185		libbpf_strlcpy(attr.map_name, map_name, sizeof(attr.map_name));
186	attr.key_size = key_size;
187	attr.value_size = value_size;
188	attr.max_entries = max_entries;
189
190	attr.btf_fd = OPTS_GET(opts, btf_fd, 0);
191	attr.btf_key_type_id = OPTS_GET(opts, btf_key_type_id, 0);
192	attr.btf_value_type_id = OPTS_GET(opts, btf_value_type_id, 0);
193	attr.btf_vmlinux_value_type_id = OPTS_GET(opts, btf_vmlinux_value_type_id, 0);
194
195	attr.inner_map_fd = OPTS_GET(opts, inner_map_fd, 0);
196	attr.map_flags = OPTS_GET(opts, map_flags, 0);
197	attr.map_extra = OPTS_GET(opts, map_extra, 0);
198	attr.numa_node = OPTS_GET(opts, numa_node, 0);
199	attr.map_ifindex = OPTS_GET(opts, map_ifindex, 0);
200
201	fd = sys_bpf_fd(BPF_MAP_CREATE, &attr, attr_sz);
202	return libbpf_err_errno(fd);
203}
204
205static void *
206alloc_zero_tailing_info(const void *orecord, __u32 cnt,
207			__u32 actual_rec_size, __u32 expected_rec_size)
208{
209	__u64 info_len = (__u64)actual_rec_size * cnt;
210	void *info, *nrecord;
211	int i;
212
213	info = malloc(info_len);
214	if (!info)
215		return NULL;
216
217	/* zero out bytes kernel does not understand */
218	nrecord = info;
219	for (i = 0; i < cnt; i++) {
220		memcpy(nrecord, orecord, expected_rec_size);
221		memset(nrecord + expected_rec_size, 0,
222		       actual_rec_size - expected_rec_size);
223		orecord += actual_rec_size;
224		nrecord += actual_rec_size;
225	}
226
227	return info;
228}
229
230int bpf_prog_load(enum bpf_prog_type prog_type,
231		  const char *prog_name, const char *license,
232		  const struct bpf_insn *insns, size_t insn_cnt,
233		  const struct bpf_prog_load_opts *opts)
234{
235	const size_t attr_sz = offsetofend(union bpf_attr, fd_array);
236	void *finfo = NULL, *linfo = NULL;
237	const char *func_info, *line_info;
238	__u32 log_size, log_level, attach_prog_fd, attach_btf_obj_fd;
239	__u32 func_info_rec_size, line_info_rec_size;
240	int fd, attempts;
241	union bpf_attr attr;
242	char *log_buf;
243
244	bump_rlimit_memlock();
245
246	if (!OPTS_VALID(opts, bpf_prog_load_opts))
247		return libbpf_err(-EINVAL);
248
249	attempts = OPTS_GET(opts, attempts, 0);
250	if (attempts < 0)
251		return libbpf_err(-EINVAL);
252	if (attempts == 0)
253		attempts = PROG_LOAD_ATTEMPTS;
254
255	memset(&attr, 0, attr_sz);
256
257	attr.prog_type = prog_type;
258	attr.expected_attach_type = OPTS_GET(opts, expected_attach_type, 0);
259
260	attr.prog_btf_fd = OPTS_GET(opts, prog_btf_fd, 0);
261	attr.prog_flags = OPTS_GET(opts, prog_flags, 0);
262	attr.prog_ifindex = OPTS_GET(opts, prog_ifindex, 0);
263	attr.kern_version = OPTS_GET(opts, kern_version, 0);
264
265	if (prog_name && kernel_supports(NULL, FEAT_PROG_NAME))
266		libbpf_strlcpy(attr.prog_name, prog_name, sizeof(attr.prog_name));
267	attr.license = ptr_to_u64(license);
268
269	if (insn_cnt > UINT_MAX)
270		return libbpf_err(-E2BIG);
271
272	attr.insns = ptr_to_u64(insns);
273	attr.insn_cnt = (__u32)insn_cnt;
274
275	attach_prog_fd = OPTS_GET(opts, attach_prog_fd, 0);
276	attach_btf_obj_fd = OPTS_GET(opts, attach_btf_obj_fd, 0);
277
278	if (attach_prog_fd && attach_btf_obj_fd)
279		return libbpf_err(-EINVAL);
280
281	attr.attach_btf_id = OPTS_GET(opts, attach_btf_id, 0);
282	if (attach_prog_fd)
283		attr.attach_prog_fd = attach_prog_fd;
284	else
285		attr.attach_btf_obj_fd = attach_btf_obj_fd;
286
287	log_buf = OPTS_GET(opts, log_buf, NULL);
288	log_size = OPTS_GET(opts, log_size, 0);
289	log_level = OPTS_GET(opts, log_level, 0);
290
291	if (!!log_buf != !!log_size)
292		return libbpf_err(-EINVAL);
293	if (log_level > (4 | 2 | 1))
294		return libbpf_err(-EINVAL);
295	if (log_level && !log_buf)
296		return libbpf_err(-EINVAL);
297
298	func_info_rec_size = OPTS_GET(opts, func_info_rec_size, 0);
299	func_info = OPTS_GET(opts, func_info, NULL);
300	attr.func_info_rec_size = func_info_rec_size;
301	attr.func_info = ptr_to_u64(func_info);
302	attr.func_info_cnt = OPTS_GET(opts, func_info_cnt, 0);
303
304	line_info_rec_size = OPTS_GET(opts, line_info_rec_size, 0);
305	line_info = OPTS_GET(opts, line_info, NULL);
306	attr.line_info_rec_size = line_info_rec_size;
307	attr.line_info = ptr_to_u64(line_info);
308	attr.line_info_cnt = OPTS_GET(opts, line_info_cnt, 0);
309
310	attr.fd_array = ptr_to_u64(OPTS_GET(opts, fd_array, NULL));
311
312	if (log_level) {
313		attr.log_buf = ptr_to_u64(log_buf);
314		attr.log_size = log_size;
315		attr.log_level = log_level;
316	}
317
318	fd = sys_bpf_prog_load(&attr, attr_sz, attempts);
319	if (fd >= 0)
320		return fd;
321
322	/* After bpf_prog_load, the kernel may modify certain attributes
323	 * to give user space a hint how to deal with loading failure.
324	 * Check to see whether we can make some changes and load again.
325	 */
326	while (errno == E2BIG && (!finfo || !linfo)) {
327		if (!finfo && attr.func_info_cnt &&
328		    attr.func_info_rec_size < func_info_rec_size) {
329			/* try with corrected func info records */
330			finfo = alloc_zero_tailing_info(func_info,
331							attr.func_info_cnt,
332							func_info_rec_size,
333							attr.func_info_rec_size);
334			if (!finfo) {
335				errno = E2BIG;
336				goto done;
337			}
338
339			attr.func_info = ptr_to_u64(finfo);
340			attr.func_info_rec_size = func_info_rec_size;
341		} else if (!linfo && attr.line_info_cnt &&
342			   attr.line_info_rec_size < line_info_rec_size) {
343			linfo = alloc_zero_tailing_info(line_info,
344							attr.line_info_cnt,
345							line_info_rec_size,
346							attr.line_info_rec_size);
347			if (!linfo) {
348				errno = E2BIG;
349				goto done;
350			}
351
352			attr.line_info = ptr_to_u64(linfo);
353			attr.line_info_rec_size = line_info_rec_size;
354		} else {
355			break;
356		}
357
358		fd = sys_bpf_prog_load(&attr, attr_sz, attempts);
359		if (fd >= 0)
360			goto done;
361	}
362
363	if (log_level == 0 && log_buf) {
364		/* log_level == 0 with non-NULL log_buf requires retrying on error
365		 * with log_level == 1 and log_buf/log_buf_size set, to get details of
366		 * failure
367		 */
368		attr.log_buf = ptr_to_u64(log_buf);
369		attr.log_size = log_size;
370		attr.log_level = 1;
371
372		fd = sys_bpf_prog_load(&attr, attr_sz, attempts);
373	}
374done:
375	/* free() doesn't affect errno, so we don't need to restore it */
376	free(finfo);
377	free(linfo);
378	return libbpf_err_errno(fd);
379}
380
381int bpf_map_update_elem(int fd, const void *key, const void *value,
382			__u64 flags)
383{
384	const size_t attr_sz = offsetofend(union bpf_attr, flags);
385	union bpf_attr attr;
386	int ret;
387
388	memset(&attr, 0, attr_sz);
389	attr.map_fd = fd;
390	attr.key = ptr_to_u64(key);
391	attr.value = ptr_to_u64(value);
392	attr.flags = flags;
393
394	ret = sys_bpf(BPF_MAP_UPDATE_ELEM, &attr, attr_sz);
395	return libbpf_err_errno(ret);
396}
397
398int bpf_map_lookup_elem(int fd, const void *key, void *value)
399{
400	const size_t attr_sz = offsetofend(union bpf_attr, flags);
401	union bpf_attr attr;
402	int ret;
403
404	memset(&attr, 0, attr_sz);
405	attr.map_fd = fd;
406	attr.key = ptr_to_u64(key);
407	attr.value = ptr_to_u64(value);
408
409	ret = sys_bpf(BPF_MAP_LOOKUP_ELEM, &attr, attr_sz);
410	return libbpf_err_errno(ret);
411}
412
413int bpf_map_lookup_elem_flags(int fd, const void *key, void *value, __u64 flags)
414{
415	const size_t attr_sz = offsetofend(union bpf_attr, flags);
416	union bpf_attr attr;
417	int ret;
418
419	memset(&attr, 0, attr_sz);
420	attr.map_fd = fd;
421	attr.key = ptr_to_u64(key);
422	attr.value = ptr_to_u64(value);
423	attr.flags = flags;
424
425	ret = sys_bpf(BPF_MAP_LOOKUP_ELEM, &attr, attr_sz);
426	return libbpf_err_errno(ret);
427}
428
429int bpf_map_lookup_and_delete_elem(int fd, const void *key, void *value)
430{
431	const size_t attr_sz = offsetofend(union bpf_attr, flags);
432	union bpf_attr attr;
433	int ret;
434
435	memset(&attr, 0, attr_sz);
436	attr.map_fd = fd;
437	attr.key = ptr_to_u64(key);
438	attr.value = ptr_to_u64(value);
439
440	ret = sys_bpf(BPF_MAP_LOOKUP_AND_DELETE_ELEM, &attr, attr_sz);
441	return libbpf_err_errno(ret);
442}
443
444int bpf_map_lookup_and_delete_elem_flags(int fd, const void *key, void *value, __u64 flags)
445{
446	const size_t attr_sz = offsetofend(union bpf_attr, flags);
447	union bpf_attr attr;
448	int ret;
449
450	memset(&attr, 0, attr_sz);
451	attr.map_fd = fd;
452	attr.key = ptr_to_u64(key);
453	attr.value = ptr_to_u64(value);
454	attr.flags = flags;
455
456	ret = sys_bpf(BPF_MAP_LOOKUP_AND_DELETE_ELEM, &attr, attr_sz);
457	return libbpf_err_errno(ret);
458}
459
460int bpf_map_delete_elem(int fd, const void *key)
461{
462	const size_t attr_sz = offsetofend(union bpf_attr, flags);
463	union bpf_attr attr;
464	int ret;
465
466	memset(&attr, 0, attr_sz);
467	attr.map_fd = fd;
468	attr.key = ptr_to_u64(key);
469
470	ret = sys_bpf(BPF_MAP_DELETE_ELEM, &attr, attr_sz);
471	return libbpf_err_errno(ret);
472}
473
474int bpf_map_delete_elem_flags(int fd, const void *key, __u64 flags)
475{
476	const size_t attr_sz = offsetofend(union bpf_attr, flags);
477	union bpf_attr attr;
478	int ret;
479
480	memset(&attr, 0, attr_sz);
481	attr.map_fd = fd;
482	attr.key = ptr_to_u64(key);
483	attr.flags = flags;
484
485	ret = sys_bpf(BPF_MAP_DELETE_ELEM, &attr, attr_sz);
486	return libbpf_err_errno(ret);
487}
488
489int bpf_map_get_next_key(int fd, const void *key, void *next_key)
490{
491	const size_t attr_sz = offsetofend(union bpf_attr, next_key);
492	union bpf_attr attr;
493	int ret;
494
495	memset(&attr, 0, attr_sz);
496	attr.map_fd = fd;
497	attr.key = ptr_to_u64(key);
498	attr.next_key = ptr_to_u64(next_key);
499
500	ret = sys_bpf(BPF_MAP_GET_NEXT_KEY, &attr, attr_sz);
501	return libbpf_err_errno(ret);
502}
503
504int bpf_map_freeze(int fd)
505{
506	const size_t attr_sz = offsetofend(union bpf_attr, map_fd);
507	union bpf_attr attr;
508	int ret;
509
510	memset(&attr, 0, attr_sz);
511	attr.map_fd = fd;
512
513	ret = sys_bpf(BPF_MAP_FREEZE, &attr, attr_sz);
514	return libbpf_err_errno(ret);
515}
516
517static int bpf_map_batch_common(int cmd, int fd, void  *in_batch,
518				void *out_batch, void *keys, void *values,
519				__u32 *count,
520				const struct bpf_map_batch_opts *opts)
521{
522	const size_t attr_sz = offsetofend(union bpf_attr, batch);
523	union bpf_attr attr;
524	int ret;
525
526	if (!OPTS_VALID(opts, bpf_map_batch_opts))
527		return libbpf_err(-EINVAL);
528
529	memset(&attr, 0, attr_sz);
530	attr.batch.map_fd = fd;
531	attr.batch.in_batch = ptr_to_u64(in_batch);
532	attr.batch.out_batch = ptr_to_u64(out_batch);
533	attr.batch.keys = ptr_to_u64(keys);
534	attr.batch.values = ptr_to_u64(values);
535	attr.batch.count = *count;
536	attr.batch.elem_flags  = OPTS_GET(opts, elem_flags, 0);
537	attr.batch.flags = OPTS_GET(opts, flags, 0);
538
539	ret = sys_bpf(cmd, &attr, attr_sz);
540	*count = attr.batch.count;
541
542	return libbpf_err_errno(ret);
543}
544
545int bpf_map_delete_batch(int fd, const void *keys, __u32 *count,
546			 const struct bpf_map_batch_opts *opts)
547{
548	return bpf_map_batch_common(BPF_MAP_DELETE_BATCH, fd, NULL,
549				    NULL, (void *)keys, NULL, count, opts);
550}
551
552int bpf_map_lookup_batch(int fd, void *in_batch, void *out_batch, void *keys,
553			 void *values, __u32 *count,
554			 const struct bpf_map_batch_opts *opts)
555{
556	return bpf_map_batch_common(BPF_MAP_LOOKUP_BATCH, fd, in_batch,
557				    out_batch, keys, values, count, opts);
558}
559
560int bpf_map_lookup_and_delete_batch(int fd, void *in_batch, void *out_batch,
561				    void *keys, void *values, __u32 *count,
562				    const struct bpf_map_batch_opts *opts)
563{
564	return bpf_map_batch_common(BPF_MAP_LOOKUP_AND_DELETE_BATCH,
565				    fd, in_batch, out_batch, keys, values,
566				    count, opts);
567}
568
569int bpf_map_update_batch(int fd, const void *keys, const void *values, __u32 *count,
570			 const struct bpf_map_batch_opts *opts)
571{
572	return bpf_map_batch_common(BPF_MAP_UPDATE_BATCH, fd, NULL, NULL,
573				    (void *)keys, (void *)values, count, opts);
574}
575
576int bpf_obj_pin(int fd, const char *pathname)
577{
578	const size_t attr_sz = offsetofend(union bpf_attr, file_flags);
579	union bpf_attr attr;
580	int ret;
581
582	memset(&attr, 0, attr_sz);
583	attr.pathname = ptr_to_u64((void *)pathname);
584	attr.bpf_fd = fd;
585
586	ret = sys_bpf(BPF_OBJ_PIN, &attr, attr_sz);
587	return libbpf_err_errno(ret);
588}
589
590int bpf_obj_get(const char *pathname)
591{
592	return bpf_obj_get_opts(pathname, NULL);
593}
594
595int bpf_obj_get_opts(const char *pathname, const struct bpf_obj_get_opts *opts)
596{
597	const size_t attr_sz = offsetofend(union bpf_attr, file_flags);
598	union bpf_attr attr;
599	int fd;
600
601	if (!OPTS_VALID(opts, bpf_obj_get_opts))
602		return libbpf_err(-EINVAL);
603
604	memset(&attr, 0, attr_sz);
605	attr.pathname = ptr_to_u64((void *)pathname);
606	attr.file_flags = OPTS_GET(opts, file_flags, 0);
607
608	fd = sys_bpf_fd(BPF_OBJ_GET, &attr, attr_sz);
609	return libbpf_err_errno(fd);
610}
611
612int bpf_prog_attach(int prog_fd, int target_fd, enum bpf_attach_type type,
613		    unsigned int flags)
614{
615	DECLARE_LIBBPF_OPTS(bpf_prog_attach_opts, opts,
616		.flags = flags,
617	);
618
619	return bpf_prog_attach_opts(prog_fd, target_fd, type, &opts);
620}
621
622int bpf_prog_attach_opts(int prog_fd, int target_fd,
623			  enum bpf_attach_type type,
624			  const struct bpf_prog_attach_opts *opts)
625{
626	const size_t attr_sz = offsetofend(union bpf_attr, replace_bpf_fd);
627	union bpf_attr attr;
628	int ret;
629
630	if (!OPTS_VALID(opts, bpf_prog_attach_opts))
631		return libbpf_err(-EINVAL);
632
633	memset(&attr, 0, attr_sz);
634	attr.target_fd	   = target_fd;
635	attr.attach_bpf_fd = prog_fd;
636	attr.attach_type   = type;
637	attr.attach_flags  = OPTS_GET(opts, flags, 0);
638	attr.replace_bpf_fd = OPTS_GET(opts, replace_prog_fd, 0);
639
640	ret = sys_bpf(BPF_PROG_ATTACH, &attr, attr_sz);
641	return libbpf_err_errno(ret);
642}
643
644int bpf_prog_detach(int target_fd, enum bpf_attach_type type)
645{
646	const size_t attr_sz = offsetofend(union bpf_attr, replace_bpf_fd);
647	union bpf_attr attr;
648	int ret;
649
650	memset(&attr, 0, attr_sz);
651	attr.target_fd	 = target_fd;
652	attr.attach_type = type;
653
654	ret = sys_bpf(BPF_PROG_DETACH, &attr, attr_sz);
655	return libbpf_err_errno(ret);
656}
657
658int bpf_prog_detach2(int prog_fd, int target_fd, enum bpf_attach_type type)
659{
660	const size_t attr_sz = offsetofend(union bpf_attr, replace_bpf_fd);
661	union bpf_attr attr;
662	int ret;
663
664	memset(&attr, 0, attr_sz);
665	attr.target_fd	 = target_fd;
666	attr.attach_bpf_fd = prog_fd;
667	attr.attach_type = type;
668
669	ret = sys_bpf(BPF_PROG_DETACH, &attr, attr_sz);
670	return libbpf_err_errno(ret);
671}
672
673int bpf_link_create(int prog_fd, int target_fd,
674		    enum bpf_attach_type attach_type,
675		    const struct bpf_link_create_opts *opts)
676{
677	const size_t attr_sz = offsetofend(union bpf_attr, link_create);
678	__u32 target_btf_id, iter_info_len;
679	union bpf_attr attr;
680	int fd, err;
681
682	if (!OPTS_VALID(opts, bpf_link_create_opts))
683		return libbpf_err(-EINVAL);
684
685	iter_info_len = OPTS_GET(opts, iter_info_len, 0);
686	target_btf_id = OPTS_GET(opts, target_btf_id, 0);
687
688	/* validate we don't have unexpected combinations of non-zero fields */
689	if (iter_info_len || target_btf_id) {
690		if (iter_info_len && target_btf_id)
691			return libbpf_err(-EINVAL);
692		if (!OPTS_ZEROED(opts, target_btf_id))
693			return libbpf_err(-EINVAL);
694	}
695
696	memset(&attr, 0, attr_sz);
697	attr.link_create.prog_fd = prog_fd;
698	attr.link_create.target_fd = target_fd;
699	attr.link_create.attach_type = attach_type;
700	attr.link_create.flags = OPTS_GET(opts, flags, 0);
701
702	if (target_btf_id) {
703		attr.link_create.target_btf_id = target_btf_id;
704		goto proceed;
705	}
706
707	switch (attach_type) {
708	case BPF_TRACE_ITER:
709		attr.link_create.iter_info = ptr_to_u64(OPTS_GET(opts, iter_info, (void *)0));
710		attr.link_create.iter_info_len = iter_info_len;
711		break;
712	case BPF_PERF_EVENT:
713		attr.link_create.perf_event.bpf_cookie = OPTS_GET(opts, perf_event.bpf_cookie, 0);
714		if (!OPTS_ZEROED(opts, perf_event))
715			return libbpf_err(-EINVAL);
716		break;
717	case BPF_TRACE_KPROBE_MULTI:
718		attr.link_create.kprobe_multi.flags = OPTS_GET(opts, kprobe_multi.flags, 0);
719		attr.link_create.kprobe_multi.cnt = OPTS_GET(opts, kprobe_multi.cnt, 0);
720		attr.link_create.kprobe_multi.syms = ptr_to_u64(OPTS_GET(opts, kprobe_multi.syms, 0));
721		attr.link_create.kprobe_multi.addrs = ptr_to_u64(OPTS_GET(opts, kprobe_multi.addrs, 0));
722		attr.link_create.kprobe_multi.cookies = ptr_to_u64(OPTS_GET(opts, kprobe_multi.cookies, 0));
723		if (!OPTS_ZEROED(opts, kprobe_multi))
724			return libbpf_err(-EINVAL);
725		break;
726	case BPF_TRACE_FENTRY:
727	case BPF_TRACE_FEXIT:
728	case BPF_MODIFY_RETURN:
729	case BPF_LSM_MAC:
730		attr.link_create.tracing.cookie = OPTS_GET(opts, tracing.cookie, 0);
731		if (!OPTS_ZEROED(opts, tracing))
732			return libbpf_err(-EINVAL);
733		break;
734	default:
735		if (!OPTS_ZEROED(opts, flags))
736			return libbpf_err(-EINVAL);
737		break;
738	}
739proceed:
740	fd = sys_bpf_fd(BPF_LINK_CREATE, &attr, attr_sz);
741	if (fd >= 0)
742		return fd;
743	/* we'll get EINVAL if LINK_CREATE doesn't support attaching fentry
744	 * and other similar programs
745	 */
746	err = -errno;
747	if (err != -EINVAL)
748		return libbpf_err(err);
749
750	/* if user used features not supported by
751	 * BPF_RAW_TRACEPOINT_OPEN command, then just give up immediately
752	 */
753	if (attr.link_create.target_fd || attr.link_create.target_btf_id)
754		return libbpf_err(err);
755	if (!OPTS_ZEROED(opts, sz))
756		return libbpf_err(err);
757
758	/* otherwise, for few select kinds of programs that can be
759	 * attached using BPF_RAW_TRACEPOINT_OPEN command, try that as
760	 * a fallback for older kernels
761	 */
762	switch (attach_type) {
763	case BPF_TRACE_RAW_TP:
764	case BPF_LSM_MAC:
765	case BPF_TRACE_FENTRY:
766	case BPF_TRACE_FEXIT:
767	case BPF_MODIFY_RETURN:
768		return bpf_raw_tracepoint_open(NULL, prog_fd);
769	default:
770		return libbpf_err(err);
771	}
772}
773
774int bpf_link_detach(int link_fd)
775{
776	const size_t attr_sz = offsetofend(union bpf_attr, link_detach);
777	union bpf_attr attr;
778	int ret;
779
780	memset(&attr, 0, attr_sz);
781	attr.link_detach.link_fd = link_fd;
782
783	ret = sys_bpf(BPF_LINK_DETACH, &attr, attr_sz);
784	return libbpf_err_errno(ret);
785}
786
787int bpf_link_update(int link_fd, int new_prog_fd,
788		    const struct bpf_link_update_opts *opts)
789{
790	const size_t attr_sz = offsetofend(union bpf_attr, link_update);
791	union bpf_attr attr;
792	int ret;
793
794	if (!OPTS_VALID(opts, bpf_link_update_opts))
795		return libbpf_err(-EINVAL);
796
797	memset(&attr, 0, attr_sz);
798	attr.link_update.link_fd = link_fd;
799	attr.link_update.new_prog_fd = new_prog_fd;
800	attr.link_update.flags = OPTS_GET(opts, flags, 0);
801	attr.link_update.old_prog_fd = OPTS_GET(opts, old_prog_fd, 0);
802
803	ret = sys_bpf(BPF_LINK_UPDATE, &attr, attr_sz);
804	return libbpf_err_errno(ret);
805}
806
807int bpf_iter_create(int link_fd)
808{
809	const size_t attr_sz = offsetofend(union bpf_attr, iter_create);
810	union bpf_attr attr;
811	int fd;
812
813	memset(&attr, 0, attr_sz);
814	attr.iter_create.link_fd = link_fd;
815
816	fd = sys_bpf_fd(BPF_ITER_CREATE, &attr, attr_sz);
817	return libbpf_err_errno(fd);
818}
819
820int bpf_prog_query_opts(int target_fd,
821			enum bpf_attach_type type,
822			struct bpf_prog_query_opts *opts)
823{
824	const size_t attr_sz = offsetofend(union bpf_attr, query);
825	union bpf_attr attr;
826	int ret;
827
828	if (!OPTS_VALID(opts, bpf_prog_query_opts))
829		return libbpf_err(-EINVAL);
830
831	memset(&attr, 0, attr_sz);
832
833	attr.query.target_fd	= target_fd;
834	attr.query.attach_type	= type;
835	attr.query.query_flags	= OPTS_GET(opts, query_flags, 0);
836	attr.query.prog_cnt	= OPTS_GET(opts, prog_cnt, 0);
837	attr.query.prog_ids	= ptr_to_u64(OPTS_GET(opts, prog_ids, NULL));
838	attr.query.prog_attach_flags = ptr_to_u64(OPTS_GET(opts, prog_attach_flags, NULL));
839
840	ret = sys_bpf(BPF_PROG_QUERY, &attr, attr_sz);
841
842	OPTS_SET(opts, attach_flags, attr.query.attach_flags);
843	OPTS_SET(opts, prog_cnt, attr.query.prog_cnt);
844
845	return libbpf_err_errno(ret);
846}
847
848int bpf_prog_query(int target_fd, enum bpf_attach_type type, __u32 query_flags,
849		   __u32 *attach_flags, __u32 *prog_ids, __u32 *prog_cnt)
850{
851	LIBBPF_OPTS(bpf_prog_query_opts, opts);
852	int ret;
853
854	opts.query_flags = query_flags;
855	opts.prog_ids = prog_ids;
856	opts.prog_cnt = *prog_cnt;
857
858	ret = bpf_prog_query_opts(target_fd, type, &opts);
859
860	if (attach_flags)
861		*attach_flags = opts.attach_flags;
862	*prog_cnt = opts.prog_cnt;
863
864	return libbpf_err_errno(ret);
865}
866
867int bpf_prog_test_run_opts(int prog_fd, struct bpf_test_run_opts *opts)
868{
869	const size_t attr_sz = offsetofend(union bpf_attr, test);
870	union bpf_attr attr;
871	int ret;
872
873	if (!OPTS_VALID(opts, bpf_test_run_opts))
874		return libbpf_err(-EINVAL);
875
876	memset(&attr, 0, attr_sz);
877	attr.test.prog_fd = prog_fd;
878	attr.test.batch_size = OPTS_GET(opts, batch_size, 0);
879	attr.test.cpu = OPTS_GET(opts, cpu, 0);
880	attr.test.flags = OPTS_GET(opts, flags, 0);
881	attr.test.repeat = OPTS_GET(opts, repeat, 0);
882	attr.test.duration = OPTS_GET(opts, duration, 0);
883	attr.test.ctx_size_in = OPTS_GET(opts, ctx_size_in, 0);
884	attr.test.ctx_size_out = OPTS_GET(opts, ctx_size_out, 0);
885	attr.test.data_size_in = OPTS_GET(opts, data_size_in, 0);
886	attr.test.data_size_out = OPTS_GET(opts, data_size_out, 0);
887	attr.test.ctx_in = ptr_to_u64(OPTS_GET(opts, ctx_in, NULL));
888	attr.test.ctx_out = ptr_to_u64(OPTS_GET(opts, ctx_out, NULL));
889	attr.test.data_in = ptr_to_u64(OPTS_GET(opts, data_in, NULL));
890	attr.test.data_out = ptr_to_u64(OPTS_GET(opts, data_out, NULL));
891
892	ret = sys_bpf(BPF_PROG_TEST_RUN, &attr, attr_sz);
893
894	OPTS_SET(opts, data_size_out, attr.test.data_size_out);
895	OPTS_SET(opts, ctx_size_out, attr.test.ctx_size_out);
896	OPTS_SET(opts, duration, attr.test.duration);
897	OPTS_SET(opts, retval, attr.test.retval);
898
899	return libbpf_err_errno(ret);
900}
901
902static int bpf_obj_get_next_id(__u32 start_id, __u32 *next_id, int cmd)
903{
904	const size_t attr_sz = offsetofend(union bpf_attr, open_flags);
905	union bpf_attr attr;
906	int err;
907
908	memset(&attr, 0, attr_sz);
909	attr.start_id = start_id;
910
911	err = sys_bpf(cmd, &attr, attr_sz);
912	if (!err)
913		*next_id = attr.next_id;
914
915	return libbpf_err_errno(err);
916}
917
918int bpf_prog_get_next_id(__u32 start_id, __u32 *next_id)
919{
920	return bpf_obj_get_next_id(start_id, next_id, BPF_PROG_GET_NEXT_ID);
921}
922
923int bpf_map_get_next_id(__u32 start_id, __u32 *next_id)
924{
925	return bpf_obj_get_next_id(start_id, next_id, BPF_MAP_GET_NEXT_ID);
926}
927
928int bpf_btf_get_next_id(__u32 start_id, __u32 *next_id)
929{
930	return bpf_obj_get_next_id(start_id, next_id, BPF_BTF_GET_NEXT_ID);
931}
932
933int bpf_link_get_next_id(__u32 start_id, __u32 *next_id)
934{
935	return bpf_obj_get_next_id(start_id, next_id, BPF_LINK_GET_NEXT_ID);
936}
937
938int bpf_prog_get_fd_by_id(__u32 id)
939{
940	const size_t attr_sz = offsetofend(union bpf_attr, open_flags);
941	union bpf_attr attr;
942	int fd;
943
944	memset(&attr, 0, attr_sz);
945	attr.prog_id = id;
946
947	fd = sys_bpf_fd(BPF_PROG_GET_FD_BY_ID, &attr, attr_sz);
948	return libbpf_err_errno(fd);
949}
950
951int bpf_map_get_fd_by_id(__u32 id)
952{
953	const size_t attr_sz = offsetofend(union bpf_attr, open_flags);
954	union bpf_attr attr;
955	int fd;
956
957	memset(&attr, 0, attr_sz);
958	attr.map_id = id;
959
960	fd = sys_bpf_fd(BPF_MAP_GET_FD_BY_ID, &attr, attr_sz);
961	return libbpf_err_errno(fd);
962}
963
964int bpf_btf_get_fd_by_id(__u32 id)
965{
966	const size_t attr_sz = offsetofend(union bpf_attr, open_flags);
967	union bpf_attr attr;
968	int fd;
969
970	memset(&attr, 0, attr_sz);
971	attr.btf_id = id;
972
973	fd = sys_bpf_fd(BPF_BTF_GET_FD_BY_ID, &attr, attr_sz);
974	return libbpf_err_errno(fd);
975}
976
977int bpf_link_get_fd_by_id(__u32 id)
978{
979	const size_t attr_sz = offsetofend(union bpf_attr, open_flags);
980	union bpf_attr attr;
981	int fd;
982
983	memset(&attr, 0, attr_sz);
984	attr.link_id = id;
985
986	fd = sys_bpf_fd(BPF_LINK_GET_FD_BY_ID, &attr, attr_sz);
987	return libbpf_err_errno(fd);
988}
989
990int bpf_obj_get_info_by_fd(int bpf_fd, void *info, __u32 *info_len)
991{
992	const size_t attr_sz = offsetofend(union bpf_attr, info);
993	union bpf_attr attr;
994	int err;
995
996	memset(&attr, 0, attr_sz);
997	attr.info.bpf_fd = bpf_fd;
998	attr.info.info_len = *info_len;
999	attr.info.info = ptr_to_u64(info);
1000
1001	err = sys_bpf(BPF_OBJ_GET_INFO_BY_FD, &attr, attr_sz);
1002	if (!err)
1003		*info_len = attr.info.info_len;
1004	return libbpf_err_errno(err);
1005}
1006
1007int bpf_raw_tracepoint_open(const char *name, int prog_fd)
1008{
1009	const size_t attr_sz = offsetofend(union bpf_attr, raw_tracepoint);
1010	union bpf_attr attr;
1011	int fd;
1012
1013	memset(&attr, 0, attr_sz);
1014	attr.raw_tracepoint.name = ptr_to_u64(name);
1015	attr.raw_tracepoint.prog_fd = prog_fd;
1016
1017	fd = sys_bpf_fd(BPF_RAW_TRACEPOINT_OPEN, &attr, attr_sz);
1018	return libbpf_err_errno(fd);
1019}
1020
1021int bpf_btf_load(const void *btf_data, size_t btf_size, const struct bpf_btf_load_opts *opts)
1022{
1023	const size_t attr_sz = offsetofend(union bpf_attr, btf_log_level);
1024	union bpf_attr attr;
1025	char *log_buf;
1026	size_t log_size;
1027	__u32 log_level;
1028	int fd;
1029
1030	bump_rlimit_memlock();
1031
1032	memset(&attr, 0, attr_sz);
1033
1034	if (!OPTS_VALID(opts, bpf_btf_load_opts))
1035		return libbpf_err(-EINVAL);
1036
1037	log_buf = OPTS_GET(opts, log_buf, NULL);
1038	log_size = OPTS_GET(opts, log_size, 0);
1039	log_level = OPTS_GET(opts, log_level, 0);
1040
1041	if (log_size > UINT_MAX)
1042		return libbpf_err(-EINVAL);
1043	if (log_size && !log_buf)
1044		return libbpf_err(-EINVAL);
1045
1046	attr.btf = ptr_to_u64(btf_data);
1047	attr.btf_size = btf_size;
1048	/* log_level == 0 and log_buf != NULL means "try loading without
1049	 * log_buf, but retry with log_buf and log_level=1 on error", which is
1050	 * consistent across low-level and high-level BTF and program loading
1051	 * APIs within libbpf and provides a sensible behavior in practice
1052	 */
1053	if (log_level) {
1054		attr.btf_log_buf = ptr_to_u64(log_buf);
1055		attr.btf_log_size = (__u32)log_size;
1056		attr.btf_log_level = log_level;
1057	}
1058
1059	fd = sys_bpf_fd(BPF_BTF_LOAD, &attr, attr_sz);
1060	if (fd < 0 && log_buf && log_level == 0) {
1061		attr.btf_log_buf = ptr_to_u64(log_buf);
1062		attr.btf_log_size = (__u32)log_size;
1063		attr.btf_log_level = 1;
1064		fd = sys_bpf_fd(BPF_BTF_LOAD, &attr, attr_sz);
1065	}
1066	return libbpf_err_errno(fd);
1067}
1068
1069int bpf_task_fd_query(int pid, int fd, __u32 flags, char *buf, __u32 *buf_len,
1070		      __u32 *prog_id, __u32 *fd_type, __u64 *probe_offset,
1071		      __u64 *probe_addr)
1072{
1073	const size_t attr_sz = offsetofend(union bpf_attr, task_fd_query);
1074	union bpf_attr attr;
1075	int err;
1076
1077	memset(&attr, 0, attr_sz);
1078	attr.task_fd_query.pid = pid;
1079	attr.task_fd_query.fd = fd;
1080	attr.task_fd_query.flags = flags;
1081	attr.task_fd_query.buf = ptr_to_u64(buf);
1082	attr.task_fd_query.buf_len = *buf_len;
1083
1084	err = sys_bpf(BPF_TASK_FD_QUERY, &attr, attr_sz);
1085
1086	*buf_len = attr.task_fd_query.buf_len;
1087	*prog_id = attr.task_fd_query.prog_id;
1088	*fd_type = attr.task_fd_query.fd_type;
1089	*probe_offset = attr.task_fd_query.probe_offset;
1090	*probe_addr = attr.task_fd_query.probe_addr;
1091
1092	return libbpf_err_errno(err);
1093}
1094
1095int bpf_enable_stats(enum bpf_stats_type type)
1096{
1097	const size_t attr_sz = offsetofend(union bpf_attr, enable_stats);
1098	union bpf_attr attr;
1099	int fd;
1100
1101	memset(&attr, 0, attr_sz);
1102	attr.enable_stats.type = type;
1103
1104	fd = sys_bpf_fd(BPF_ENABLE_STATS, &attr, attr_sz);
1105	return libbpf_err_errno(fd);
1106}
1107
1108int bpf_prog_bind_map(int prog_fd, int map_fd,
1109		      const struct bpf_prog_bind_opts *opts)
1110{
1111	const size_t attr_sz = offsetofend(union bpf_attr, prog_bind_map);
1112	union bpf_attr attr;
1113	int ret;
1114
1115	if (!OPTS_VALID(opts, bpf_prog_bind_opts))
1116		return libbpf_err(-EINVAL);
1117
1118	memset(&attr, 0, attr_sz);
1119	attr.prog_bind_map.prog_fd = prog_fd;
1120	attr.prog_bind_map.map_fd = map_fd;
1121	attr.prog_bind_map.flags = OPTS_GET(opts, flags, 0);
1122
1123	ret = sys_bpf(BPF_PROG_BIND_MAP, &attr, attr_sz);
1124	return libbpf_err_errno(ret);
1125}
1126