aboutsummaryrefslogtreecommitdiff
path: root/tools/bpf/bpftool/common.c
blob: fc8172a4969ae1b4f365ee6ca7b84739981981fa (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
/* Copyright (C) 2017-2018 Netronome Systems, Inc. */

#define _GNU_SOURCE
#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <ftw.h>
#include <libgen.h>
#include <mntent.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <net/if.h>
#include <sys/mount.h>
#include <sys/resource.h>
#include <sys/stat.h>
#include <sys/vfs.h>

#include <linux/filter.h>
#include <linux/limits.h>
#include <linux/magic.h>
#include <linux/unistd.h>

#include <bpf/bpf.h>
#include <bpf/hashmap.h>
#include <bpf/libbpf.h> /* libbpf_num_possible_cpus */
#include <bpf/btf.h>

#include "main.h"

#ifndef BPF_FS_MAGIC
#define BPF_FS_MAGIC		0xcafe4a11
#endif

void p_err(const char *fmt, ...)
{
	va_list ap;

	va_start(ap, fmt);
	if (json_output) {
		jsonw_start_object(json_wtr);
		jsonw_name(json_wtr, "error");
		jsonw_vprintf_enquote(json_wtr, fmt, ap);
		jsonw_end_object(json_wtr);
	} else {
		fprintf(stderr, "Error: ");
		vfprintf(stderr, fmt, ap);
		fprintf(stderr, "\n");
	}
	va_end(ap);
}

void p_info(const char *fmt, ...)
{
	va_list ap;

	if (json_output)
		return;

	va_start(ap, fmt);
	vfprintf(stderr, fmt, ap);
	fprintf(stderr, "\n");
	va_end(ap);
}

static bool is_bpffs(char *path)
{
	struct statfs st_fs;

	if (statfs(path, &st_fs) < 0)
		return false;

	return (unsigned long)st_fs.f_type == BPF_FS_MAGIC;
}

/* Probe whether kernel switched from memlock-based (RLIMIT_MEMLOCK) to
 * memcg-based memory accounting for BPF maps and programs. This was done in
 * commit 97306be45fbe ("Merge branch 'switch to memcg-based memory
 * accounting'"), in Linux 5.11.
 *
 * Libbpf also offers to probe for memcg-based accounting vs rlimit, but does
 * so by checking for the availability of a given BPF helper and this has
 * failed on some kernels with backports in the past, see commit 6b4384ff1088
 * ("Revert "bpftool: Use libbpf 1.0 API mode instead of RLIMIT_MEMLOCK"").
 * Instead, we can probe by lowering the process-based rlimit to 0, trying to
 * load a BPF object, and resetting the rlimit. If the load succeeds then
 * memcg-based accounting is supported.
 *
 * This would be too dangerous to do in the library, because multithreaded
 * applications might attempt to load items while the rlimit is at 0. Given
 * that bpftool is single-threaded, this is fine to do here.
 */
static bool known_to_need_rlimit(void)
{
	struct rlimit rlim_init, rlim_cur_zero = {};
	struct bpf_insn insns[] = {
		BPF_MOV64_IMM(BPF_REG_0, 0),
		BPF_EXIT_INSN(),
	};
	size_t insn_cnt = ARRAY_SIZE(insns);
	union bpf_attr attr;
	int prog_fd, err;

	memset(&attr, 0, sizeof(attr));
	attr.prog_type = BPF_PROG_TYPE_SOCKET_FILTER;
	attr.insns = ptr_to_u64(insns);
	attr.insn_cnt = insn_cnt;
	attr.license = ptr_to_u64("GPL");

	if (getrlimit(RLIMIT_MEMLOCK, &rlim_init))
		return false;

	/* Drop the soft limit to zero. We maintain the hard limit to its
	 * current value, because lowering it would be a permanent operation
	 * for unprivileged users.
	 */
	rlim_cur_zero.rlim_max = rlim_init.rlim_max;
	if (setrlimit(RLIMIT_MEMLOCK, &rlim_cur_zero))
		return false;

	/* Do not use bpf_prog_load() from libbpf here, because it calls
	 * bump_rlimit_memlock(), interfering with the current probe.
	 */
	prog_fd = syscall(__NR_bpf, BPF_PROG_LOAD, &attr, sizeof(attr));
	err = errno;

	/* reset soft rlimit to its initial value */
	setrlimit(RLIMIT_MEMLOCK, &rlim_init);

	if (prog_fd < 0)
		return err == EPERM;

	close(prog_fd);
	return false;
}

void set_max_rlimit(void)
{
	struct rlimit rinf = { RLIM_INFINITY, RLIM_INFINITY };

	if (known_to_need_rlimit())
		setrlimit(RLIMIT_MEMLOCK, &rinf);
}

static int
mnt_fs(const char *target, const char *type, char *buff, size_t bufflen)
{
	bool bind_done = false;

	while (mount("", target, "none", MS_PRIVATE | MS_REC, NULL)) {
		if (errno != EINVAL || bind_done) {
			snprintf(buff, bufflen,
				 "mount --make-private %s failed: %s",
				 target, strerror(errno));
			return -1;
		}

		if (mount(target, target, "none", MS_BIND, NULL)) {
			snprintf(buff, bufflen,
				 "mount --bind %s %s failed: %s",
				 target, target, strerror(errno));
			return -1;
		}

		bind_done = true;
	}

	if (mount(type, target, type, 0, "mode=0700")) {
		snprintf(buff, bufflen, "mount -t %s %s %s failed: %s",
			 type, type, target, strerror(errno));
		return -1;
	}

	return 0;
}

int mount_tracefs(const char *target)
{
	char err_str[ERR_MAX_LEN];
	int err;

	err = mnt_fs(target, "tracefs", err_str, ERR_MAX_LEN);
	if (err) {
		err_str[ERR_MAX_LEN - 1] = '\0';
		p_err("can't mount tracefs: %s", err_str);
	}

	return err;
}

int open_obj_pinned(const char *path, bool quiet)
{
	char *pname;
	int fd = -1;

	pname = strdup(path);
	if (!pname) {
		if (!quiet)
			p_err("mem alloc failed");
		goto out_ret;
	}

	fd = bpf_obj_get(pname);
	if (fd < 0) {
		if (!quiet)
			p_err("bpf obj get (%s): %s", pname,
			      errno == EACCES && !is_bpffs(dirname(pname)) ?
			    "directory not in bpf file system (bpffs)" :
			    strerror(errno));
		goto out_free;
	}

out_free:
	free(pname);
out_ret:
	return fd;
}

int open_obj_pinned_any(const char *path, enum bpf_obj_type exp_type)
{
	enum bpf_obj_type type;
	int fd;

	fd = open_obj_pinned(path, false);
	if (fd < 0)
		return -1;

	type = get_fd_type(fd);
	if (type < 0) {
		close(fd);
		return type;
	}
	if (type != exp_type) {
		p_err("incorrect object type: %s", get_fd_type_name(type));
		close(fd);
		return -1;
	}

	return fd;
}

int mount_bpffs_for_pin(const char *name)
{
	char err_str[ERR_MAX_LEN];
	char *file;
	char *dir;
	int err = 0;

	file = malloc(strlen(name) + 1);
	if (!file) {
		p_err("mem alloc failed");
		return -1;
	}

	strcpy(file, name);
	dir = dirname(file);

	if (is_bpffs(dir))
		/* nothing to do if already mounted */
		goto out_free;

	if (block_mount) {
		p_err("no BPF file system found, not mounting it due to --nomount option");
		err = -1;
		goto out_free;
	}

	err = mnt_fs(dir, "bpf", err_str, ERR_MAX_LEN);
	if (err) {
		err_str[ERR_MAX_LEN - 1] = '\0';
		p_err("can't mount BPF file system to pin the object (%s): %s",
		      name, err_str);
	}

out_free:
	free(file);
	return err;
}

int do_pin_fd(int fd, const char *name)
{
	int err;

	err = mount_bpffs_for_pin(name);
	if (err)
		return err;

	err = bpf_obj_pin(fd, name);
	if (err)
		p_err("can't pin the object (%s): %s", name, strerror(errno));

	return err;
}

int do_pin_any(int argc, char **argv, int (*get_fd)(int *, char ***))
{
	int err;
	int fd;

	fd = get_fd(&argc, &argv);
	if (fd < 0)
		return fd;

	err = do_pin_fd(fd, *argv);

	close(fd);
	return err;
}

const char *get_fd_type_name(enum bpf_obj_type type)
{
	static const char * const names[] = {
		[BPF_OBJ_UNKNOWN]	= "unknown",
		[BPF_OBJ_PROG]		= "prog",
		[BPF_OBJ_MAP]		= "map",
	};

	if (type < 0 || type >= ARRAY_SIZE(names) || !names[type])
		return names[BPF_OBJ_UNKNOWN];

	return names[type];
}

void get_prog_full_name(const struct bpf_prog_info *prog_info, int prog_fd,
			char *name_buff, size_t buff_len)
{
	const char *prog_name = prog_info->name;
	const struct btf_type *func_type;
	const struct bpf_func_info finfo = {};
	struct bpf_prog_info info = {};
	__u32 info_len = sizeof(info);
	struct btf *prog_btf = NULL;

	if (buff_len <= BPF_OBJ_NAME_LEN ||
	    strlen(prog_info->name) < BPF_OBJ_NAME_LEN - 1)
		goto copy_name;

	if (!prog_info->btf_id || prog_info->nr_func_info == 0)
		goto copy_name;

	info.nr_func_info = 1;
	info.func_info_rec_size = prog_info->func_info_rec_size;
	if (info.func_info_rec_size > sizeof(finfo))
		info.func_info_rec_size = sizeof(finfo);
	info.func_info = ptr_to_u64(&finfo);

	if (bpf_obj_get_info_by_fd(prog_fd, &info, &info_len))
		goto copy_name;

	prog_btf = btf__load_from_kernel_by_id(info.btf_id);
	if (!prog_btf)
		goto copy_name;

	func_type = btf__type_by_id(prog_btf, finfo.type_id);
	if (!func_type || !btf_is_func(func_type))
		goto copy_name;

	prog_name = btf__name_by_offset(prog_btf, func_type->name_off);

copy_name:
	snprintf(name_buff, buff_len, "%s", prog_name);

	if (prog_btf)
		btf__free(prog_btf);
}

int get_fd_type(int fd)
{
	char path[PATH_MAX];
	char buf[512];
	ssize_t n;

	snprintf(path, sizeof(path), "/proc/self/fd/%d", fd);

	n = readlink(path, buf, sizeof(buf));
	if (n < 0) {
		p_err("can't read link type: %s", strerror(errno));
		return -1;
	}
	if (n == sizeof(path)) {
		p_err("can't read link type: path too long!");
		return -1;
	}

	if (strstr(buf, "bpf-map"))
		return BPF_OBJ_MAP;
	else if (strstr(buf, "bpf-prog"))
		return BPF_OBJ_PROG;
	else if (strstr(buf, "bpf-link"))
		return BPF_OBJ_LINK;

	return BPF_OBJ_UNKNOWN;
}

char *get_fdinfo(int fd, const char *key)
{
	char path[PATH_MAX];
	char *line = NULL;
	size_t line_n = 0;
	ssize_t n;
	FILE *fdi;

	snprintf(path, sizeof(path), "/proc/self/fdinfo/%d", fd);

	fdi = fopen(path, "r");
	if (!fdi)
		return NULL;

	while ((n = getline(&line, &line_n, fdi)) > 0) {
		char *value;
		int len;

		if (!strstr(line, key))
			continue;

		fclose(fdi);

		value = strchr(line, '\t');
		if (!value || !value[1]) {
			free(line);
			return NULL;
		}
		value++;

		len = strlen(value);
		memmove(line, value, len);
		line[len - 1] = '\0';

		return line;
	}

	free(line);
	fclose(fdi);
	return NULL;
}

void print_data_json(uint8_t *data, size_t len)
{
	unsigned int i;

	jsonw_start_array(json_wtr);
	for (i = 0; i < len; i++)
		jsonw_printf(json_wtr, "%d", data[i]);
	jsonw_end_array(json_wtr);
}

void print_hex_data_json(uint8_t *data, size_t len)
{
	unsigned int i;

	jsonw_start_array(json_wtr);
	for (i = 0; i < len; i++)
		jsonw_printf(json_wtr, "\"0x%02hhx\"", data[i]);
	jsonw_end_array(json_wtr);
}

/* extra params for nftw cb */
static struct hashmap *build_fn_table;
static enum bpf_obj_type build_fn_type;

static int do_build_table_cb(const char *fpath, const struct stat *sb,
			     int typeflag, struct FTW *ftwbuf)
{
	struct bpf_prog_info pinned_info;
	__u32 len = sizeof(pinned_info);
	enum bpf_obj_type objtype;
	int fd, err = 0;
	char *path;

	if (typeflag != FTW_F)
		goto out_ret;

	fd = open_obj_pinned(fpath, true);
	if (fd < 0)
		goto out_ret;

	objtype = get_fd_type(fd);
	if (objtype != build_fn_type)
		goto out_close;

	memset(&pinned_info, 0, sizeof(pinned_info));
	if (bpf_obj_get_info_by_fd(fd, &pinned_info, &len))
		goto out_close;

	path = strdup(fpath);
	if (!path) {
		err = -1;
		goto out_close;
	}

	err = hashmap__append(build_fn_table, u32_as_hash_field(pinned_info.id), path);
	if (err) {
		p_err("failed to append entry to hashmap for ID %u, path '%s': %s",
		      pinned_info.id, path, strerror(errno));
		goto out_close;
	}

out_close:
	close(fd);
out_ret:
	return err;
}

int build_pinned_obj_table(struct hashmap *tab,
			   enum bpf_obj_type type)
{
	struct mntent *mntent = NULL;
	FILE *mntfile = NULL;
	int flags = FTW_PHYS;
	int nopenfd = 16;
	int err = 0;

	mntfile = setmntent("/proc/mounts", "r");
	if (!mntfile)
		return -1;

	build_fn_table = tab;
	build_fn_type = type;

	while ((mntent = getmntent(mntfile))) {
		char *path = mntent->mnt_dir;

		if (strncmp(mntent->mnt_type, "bpf", 3) != 0)
			continue;
		err = nftw(path, do_build_table_cb, nopenfd, flags);
		if (err)
			break;
	}
	fclose(mntfile);
	return err;
}

void delete_pinned_obj_table(struct hashmap *map)
{
	struct hashmap_entry *entry;
	size_t bkt;

	if (!map)
		return;

	hashmap__for_each_entry(map, entry, bkt)
		free(entry->value);

	hashmap__free(map);
}

unsigned int get_page_size(void)
{
	static int result;

	if (!result)
		result = getpagesize();
	return result;
}

unsigned int get_possible_cpus(void)
{
	int cpus = libbpf_num_possible_cpus();

	if (cpus < 0) {
		p_err("Can't get # of possible cpus: %s", strerror(-cpus));
		exit(-1);
	}
	return cpus;
}

static char *
ifindex_to_name_ns(__u32 ifindex, __u32 ns_dev, __u32 ns_ino, char *buf)
{
	struct stat st;
	int err;

	err = stat("/proc/self/ns/net", &st);
	if (err) {
		p_err("Can't stat /proc/self: %s", strerror(errno));
		return NULL;
	}

	if (st.st_dev != ns_dev || st.st_ino != ns_ino)
		return NULL;

	return if_indextoname(ifindex, buf);
}

static int read_sysfs_hex_int(char *path)
{
	char vendor_id_buf[8];
	int len;
	int fd;

	fd = open(path, O_RDONLY);
	if (fd < 0) {
		p_err("Can't open %s: %s", path, strerror(errno));
		return -1;
	}

	len = read(fd, vendor_id_buf, sizeof(vendor_id_buf));
	close(fd);
	if (len < 0) {
		p_err("Can't read %s: %s", path, strerror(errno));
		return -1;
	}
	if (len >= (int)sizeof(vendor_id_buf)) {
		p_err("Value in %s too long", path);
		return -1;
	}

	vendor_id_buf[len] = 0;

	return strtol(vendor_id_buf, NULL, 0);
}

static int read_sysfs_netdev_hex_int(char *devname, const char *entry_name)
{
	char full_path[64];

	snprintf(full_path, sizeof(full_path), "/sys/class/net/%s/device/%s",
		 devname, entry_name);

	return read_sysfs_hex_int(full_path);
}

const char *
ifindex_to_bfd_params(__u32 ifindex, __u64 ns_dev, __u64 ns_ino,
		      const char **opt)
{
	char devname[IF_NAMESIZE];
	int vendor_id;
	int device_id;

	if (!ifindex_to_name_ns(ifindex, ns_dev, ns_ino, devname)) {
		p_err("Can't get net device name for ifindex %d: %s", ifindex,
		      strerror(errno));
		return NULL;
	}

	vendor_id = read_sysfs_netdev_hex_int(devname, "vendor");
	if (vendor_id < 0) {
		p_err("Can't get device vendor id for %s", devname);
		return NULL;
	}

	switch (vendor_id) {
	case 0x19ee:
		device_id = read_sysfs_netdev_hex_int(devname, "device");
		if (device_id != 0x4000 &&
		    device_id != 0x6000 &&
		    device_id != 0x6003)
			p_info("Unknown NFP device ID, assuming it is NFP-6xxx arch");
		*opt = "ctx4";
		return "NFP-6xxx";
	default:
		p_err("Can't get bfd arch name for device vendor id 0x%04x",
		      vendor_id);
		return NULL;
	}
}

void print_dev_plain(__u32 ifindex, __u64 ns_dev, __u64 ns_inode)
{
	char name[IF_NAMESIZE];

	if (!ifindex)
		return;

	printf("  offloaded_to ");
	if (ifindex_to_name_ns(ifindex, ns_dev, ns_inode, name))
		printf("%s", name);
	else
		printf("ifindex %u ns_dev %llu ns_ino %llu",
		       ifindex, ns_dev, ns_inode);
}

void print_dev_json(__u32 ifindex, __u64 ns_dev, __u64 ns_inode)
{
	char name[IF_NAMESIZE];

	if (!ifindex)
		return;

	jsonw_name(json_wtr, "dev");
	jsonw_start_object(json_wtr);
	jsonw_uint_field(json_wtr, "ifindex", ifindex);
	jsonw_uint_field(json_wtr, "ns_dev", ns_dev);
	jsonw_uint_field(json_wtr, "ns_inode", ns_inode);
	if (ifindex_to_name_ns(ifindex, ns_dev, ns_inode, name))
		jsonw_string_field(json_wtr, "ifname", name);
	jsonw_end_object(json_wtr);
}

int parse_u32_arg(int *argc, char ***argv, __u32 *val, const char *what)
{
	char *endptr;

	NEXT_ARGP();

	if (*val) {
		p_err("%s already specified", what);
		return -1;
	}

	*val = strtoul(**argv, &endptr, 0);
	if (*endptr) {
		p_err("can't parse %s as %s", **argv, what);
		return -1;
	}
	NEXT_ARGP();

	return 0;
}

int __printf(2, 0)
print_all_levels(__maybe_unused enum libbpf_print_level level,
		 const char *format, va_list args)
{
	return vfprintf(stderr, format, args);
}

static int prog_fd_by_nametag(void *nametag, int **fds, bool tag)
{
	unsigned int id = 0;
	int fd, nb_fds = 0;
	void *tmp;
	int err;

	while (true) {
		struct bpf_prog_info info = {};
		__u32 len = sizeof(info);

		err = bpf_prog_get_next_id(id, &id);
		if (err) {
			if (errno != ENOENT) {
				p_err("%s", strerror(errno));
				goto err_close_fds;
			}
			return nb_fds;
		}

		fd = bpf_prog_get_fd_by_id(id);
		if (fd < 0) {
			p_err("can't get prog by id (%u): %s",
			      id, strerror(errno));
			goto err_close_fds;
		}

		err = bpf_obj_get_info_by_fd(fd, &info, &len);
		if (err) {
			p_err("can't get prog info (%u): %s",
			      id, strerror(errno));
			goto err_close_fd;
		}

		if ((tag && memcmp(nametag, info.tag, BPF_TAG_SIZE)) ||
		    (!tag && strncmp(nametag, info.name, BPF_OBJ_NAME_LEN))) {
			close(fd);
			continue;
		}

		if (nb_fds > 0) {
			tmp = realloc(*fds, (nb_fds + 1) * sizeof(int));
			if (!tmp) {
				p_err("failed to realloc");
				goto err_close_fd;
			}
			*fds = tmp;
		}
		(*fds)[nb_fds++] = fd;
	}

err_close_fd:
	close(fd);
err_close_fds:
	while (--nb_fds >= 0)
		close((*fds)[nb_fds]);
	return -1;
}

int prog_parse_fds(int *argc, char ***argv, int **fds)
{
	if (is_prefix(**argv, "id")) {
		unsigned int id;
		char *endptr;

		NEXT_ARGP();

		id = strtoul(**argv, &endptr, 0);
		if (*endptr) {
			p_err("can't parse %s as ID", **argv);
			return -1;
		}
		NEXT_ARGP();

		(*fds)[0] = bpf_prog_get_fd_by_id(id);
		if ((*fds)[0] < 0) {
			p_err("get by id (%u): %s", id, strerror(errno));
			return -1;
		}
		return 1;
	} else if (is_prefix(**argv, "tag")) {
		unsigned char tag[BPF_TAG_SIZE];

		NEXT_ARGP();

		if (sscanf(**argv, BPF_TAG_FMT, tag, tag + 1, tag + 2,
			   tag + 3, tag + 4, tag + 5, tag + 6, tag + 7)
		    != BPF_TAG_SIZE) {
			p_err("can't parse tag");
			return -1;
		}
		NEXT_ARGP();

		return prog_fd_by_nametag(tag, fds, true);
	} else if (is_prefix(**argv, "name")) {
		char *name;

		NEXT_ARGP();

		name = **argv;
		if (strlen(name) > BPF_OBJ_NAME_LEN - 1) {
			p_err("can't parse name");
			return -1;
		}
		NEXT_ARGP();

		return prog_fd_by_nametag(name, fds, false);
	} else if (is_prefix(**argv, "pinned")) {
		char *path;

		NEXT_ARGP();

		path = **argv;
		NEXT_ARGP();

		(*fds)[0] = open_obj_pinned_any(path, BPF_OBJ_PROG);
		if ((*fds)[0] < 0)
			return -1;
		return 1;
	}

	p_err("expected 'id', 'tag', 'name' or 'pinned', got: '%s'?", **argv);
	return -1;
}

int prog_parse_fd(int *argc, char ***argv)
{
	int *fds = NULL;
	int nb_fds, fd;

	fds = malloc(sizeof(int));
	if (!fds) {
		p_err("mem alloc failed");
		return -1;
	}
	nb_fds = prog_parse_fds(argc, argv, &fds);
	if (nb_fds != 1) {
		if (nb_fds > 1) {
			p_err("several programs match this handle");
			while (nb_fds--)
				close(fds[nb_fds]);
		}
		fd = -1;
		goto exit_free;
	}

	fd = fds[0];
exit_free:
	free(fds);
	return fd;
}

static int map_fd_by_name(char *name, int **fds)
{
	unsigned int id = 0;
	int fd, nb_fds = 0;
	void *tmp;
	int err;

	while (true) {
		struct bpf_map_info info = {};
		__u32 len = sizeof(info);

		err = bpf_map_get_next_id(id, &id);
		if (err) {
			if (errno != ENOENT) {
				p_err("%s", strerror(errno));
				goto err_close_fds;
			}
			return nb_fds;
		}

		fd = bpf_map_get_fd_by_id(id);
		if (fd < 0) {
			p_err("can't get map by id (%u): %s",
			      id, strerror(errno));
			goto err_close_fds;
		}

		err = bpf_obj_get_info_by_fd(fd, &info, &len);
		if (err) {
			p_err("can't get map info (%u): %s",
			      id, strerror(errno));
			goto err_close_fd;
		}

		if (strncmp(name, info.name, BPF_OBJ_NAME_LEN)) {
			close(fd);
			continue;
		}

		if (nb_fds > 0) {
			tmp = realloc(*fds, (nb_fds + 1) * sizeof(int));
			if (!tmp) {
				p_err("failed to realloc");
				goto err_close_fd;
			}
			*fds = tmp;
		}
		(*fds)[nb_fds++] = fd;
	}

err_close_fd:
	close(fd);
err_close_fds:
	while (--nb_fds >= 0)
		close((*fds)[nb_fds]);
	return -1;
}

int map_parse_fds(int *argc, char ***argv, int **fds)
{
	if (is_prefix(**argv, "id")) {
		unsigned int id;
		char *endptr;

		NEXT_ARGP();

		id = strtoul(**argv, &endptr, 0);
		if (*endptr) {
			p_err("can't parse %s as ID", **argv);
			return -1;
		}
		NEXT_ARGP();

		(*fds)[0] = bpf_map_get_fd_by_id(id);
		if ((*fds)[0] < 0) {
			p_err("get map by id (%u): %s", id, strerror(errno));
			return -1;
		}
		return 1;
	} else if (is_prefix(**argv, "name")) {
		char *name;

		NEXT_ARGP();

		name = **argv;
		if (strlen(name) > BPF_OBJ_NAME_LEN - 1) {
			p_err("can't parse name");
			return -1;
		}
		NEXT_ARGP();

		return map_fd_by_name(name, fds);
	} else if (is_prefix(**argv, "pinned")) {
		char *path;

		NEXT_ARGP();

		path = **argv;
		NEXT_ARGP();

		(*fds)[0] = open_obj_pinned_any(path, BPF_OBJ_MAP);
		if ((*fds)[0] < 0)
			return -1;
		return 1;
	}

	p_err("expected 'id', 'name' or 'pinned', got: '%s'?", **argv);
	return -1;
}

int map_parse_fd(int *argc, char ***argv)
{
	int *fds = NULL;
	int nb_fds, fd;

	fds = malloc(sizeof(int));
	if (!fds) {
		p_err("mem alloc failed");
		return -1;
	}
	nb_fds = map_parse_fds(argc, argv, &fds);
	if (nb_fds != 1) {
		if (nb_fds > 1) {
			p_err("several maps match this handle");
			while (nb_fds--)
				close(fds[nb_fds]);
		}
		fd = -1;
		goto exit_free;
	}

	fd = fds[0];
exit_free:
	free(fds);
	return fd;
}

int map_parse_fd_and_info(int *argc, char ***argv, void *info, __u32 *info_len)
{
	int err;
	int fd;

	fd = map_parse_fd(argc, argv);
	if (fd < 0)
		return -1;

	err = bpf_obj_get_info_by_fd(fd, info, info_len);
	if (err) {
		p_err("can't get map info: %s", strerror(errno));
		close(fd);
		return err;
	}

	return fd;
}

size_t hash_fn_for_key_as_id(const void *key, void *ctx)
{
	return (size_t)key;
}

bool equal_fn_for_key_as_id(const void *k1, const void *k2, void *ctx)
{
	return k1 == k2;
}

const char *bpf_attach_type_input_str(enum bpf_attach_type t)
{
	switch (t) {
	case BPF_CGROUP_INET_INGRESS:		return "ingress";
	case BPF_CGROUP_INET_EGRESS:		return "egress";
	case BPF_CGROUP_INET_SOCK_CREATE:	return "sock_create";
	case BPF_CGROUP_INET_SOCK_RELEASE:	return "sock_release";
	case BPF_CGROUP_SOCK_OPS:		return "sock_ops";
	case BPF_CGROUP_DEVICE:			return "device";
	case BPF_CGROUP_INET4_BIND:		return "bind4";
	case BPF_CGROUP_INET6_BIND:		return "bind6";
	case BPF_CGROUP_INET4_CONNECT:		return "connect4";
	case BPF_CGROUP_INET6_CONNECT:		return "connect6";
	case BPF_CGROUP_INET4_POST_BIND:	return "post_bind4";
	case BPF_CGROUP_INET6_POST_BIND:	return "post_bind6";
	case BPF_CGROUP_INET4_GETPEERNAME:	return "getpeername4";
	case BPF_CGROUP_INET6_GETPEERNAME:	return "getpeername6";
	case BPF_CGROUP_INET4_GETSOCKNAME:	return "getsockname4";
	case BPF_CGROUP_INET6_GETSOCKNAME:	return "getsockname6";
	case BPF_CGROUP_UDP4_SENDMSG:		return "sendmsg4";
	case BPF_CGROUP_UDP6_SENDMSG:		return "sendmsg6";
	case BPF_CGROUP_SYSCTL:			return "sysctl";
	case BPF_CGROUP_UDP4_RECVMSG:		return "recvmsg4";
	case BPF_CGROUP_UDP6_RECVMSG:		return "recvmsg6";
	case BPF_CGROUP_GETSOCKOPT:		return "getsockopt";
	case BPF_CGROUP_SETSOCKOPT:		return "setsockopt";
	case BPF_TRACE_RAW_TP:			return "raw_tp";
	case BPF_TRACE_FENTRY:			return "fentry";
	case BPF_TRACE_FEXIT:			return "fexit";
	case BPF_MODIFY_RETURN:			return "mod_ret";
	case BPF_SK_REUSEPORT_SELECT:		return "sk_skb_reuseport_select";
	case BPF_SK_REUSEPORT_SELECT_OR_MIGRATE:	return "sk_skb_reuseport_select_or_migrate";
	default:	return libbpf_bpf_attach_type_str(t);
	}
}