xref: /linux/tools/bpf/bpftool/common.c (revision 7b82e90411826deee07c180ec35f64d31051d154)
1 // SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
2 /* Copyright (C) 2017-2018 Netronome Systems, Inc. */
3 
4 #ifndef _GNU_SOURCE
5 #define _GNU_SOURCE
6 #endif
7 #include <ctype.h>
8 #include <errno.h>
9 #include <fcntl.h>
10 #include <ftw.h>
11 #include <libgen.h>
12 #include <mntent.h>
13 #include <stdbool.h>
14 #include <stdio.h>
15 #include <stdlib.h>
16 #include <string.h>
17 #include <unistd.h>
18 #include <net/if.h>
19 #include <sys/mount.h>
20 #include <sys/resource.h>
21 #include <sys/stat.h>
22 #include <sys/vfs.h>
23 
24 #include <linux/filter.h>
25 #include <linux/limits.h>
26 #include <linux/magic.h>
27 #include <linux/unistd.h>
28 
29 #include <bpf/bpf.h>
30 #include <bpf/hashmap.h>
31 #include <bpf/libbpf.h> /* libbpf_num_possible_cpus */
32 #include <bpf/btf.h>
33 
34 #include "main.h"
35 
36 #ifndef BPF_FS_MAGIC
37 #define BPF_FS_MAGIC		0xcafe4a11
38 #endif
39 
40 void p_err(const char *fmt, ...)
41 {
42 	va_list ap;
43 
44 	va_start(ap, fmt);
45 	if (json_output) {
46 		jsonw_start_object(json_wtr);
47 		jsonw_name(json_wtr, "error");
48 		jsonw_vprintf_enquote(json_wtr, fmt, ap);
49 		jsonw_end_object(json_wtr);
50 	} else {
51 		fprintf(stderr, "Error: ");
52 		vfprintf(stderr, fmt, ap);
53 		fprintf(stderr, "\n");
54 	}
55 	va_end(ap);
56 }
57 
58 void p_info(const char *fmt, ...)
59 {
60 	va_list ap;
61 
62 	if (json_output)
63 		return;
64 
65 	va_start(ap, fmt);
66 	vfprintf(stderr, fmt, ap);
67 	fprintf(stderr, "\n");
68 	va_end(ap);
69 }
70 
71 static bool is_bpffs(const char *path)
72 {
73 	struct statfs st_fs;
74 
75 	if (statfs(path, &st_fs) < 0)
76 		return false;
77 
78 	return (unsigned long)st_fs.f_type == BPF_FS_MAGIC;
79 }
80 
81 /* Probe whether kernel switched from memlock-based (RLIMIT_MEMLOCK) to
82  * memcg-based memory accounting for BPF maps and programs. This was done in
83  * commit 97306be45fbe ("Merge branch 'switch to memcg-based memory
84  * accounting'"), in Linux 5.11.
85  *
86  * Libbpf also offers to probe for memcg-based accounting vs rlimit, but does
87  * so by checking for the availability of a given BPF helper and this has
88  * failed on some kernels with backports in the past, see commit 6b4384ff1088
89  * ("Revert "bpftool: Use libbpf 1.0 API mode instead of RLIMIT_MEMLOCK"").
90  * Instead, we can probe by lowering the process-based rlimit to 0, trying to
91  * load a BPF object, and resetting the rlimit. If the load succeeds then
92  * memcg-based accounting is supported.
93  *
94  * This would be too dangerous to do in the library, because multithreaded
95  * applications might attempt to load items while the rlimit is at 0. Given
96  * that bpftool is single-threaded, this is fine to do here.
97  */
98 static bool known_to_need_rlimit(void)
99 {
100 	struct rlimit rlim_init, rlim_cur_zero = {};
101 	struct bpf_insn insns[] = {
102 		BPF_MOV64_IMM(BPF_REG_0, 0),
103 		BPF_EXIT_INSN(),
104 	};
105 	size_t insn_cnt = ARRAY_SIZE(insns);
106 	union bpf_attr attr;
107 	int prog_fd, err;
108 
109 	memset(&attr, 0, sizeof(attr));
110 	attr.prog_type = BPF_PROG_TYPE_SOCKET_FILTER;
111 	attr.insns = ptr_to_u64(insns);
112 	attr.insn_cnt = insn_cnt;
113 	attr.license = ptr_to_u64("GPL");
114 
115 	if (getrlimit(RLIMIT_MEMLOCK, &rlim_init))
116 		return false;
117 
118 	/* Drop the soft limit to zero. We maintain the hard limit to its
119 	 * current value, because lowering it would be a permanent operation
120 	 * for unprivileged users.
121 	 */
122 	rlim_cur_zero.rlim_max = rlim_init.rlim_max;
123 	if (setrlimit(RLIMIT_MEMLOCK, &rlim_cur_zero))
124 		return false;
125 
126 	/* Do not use bpf_prog_load() from libbpf here, because it calls
127 	 * bump_rlimit_memlock(), interfering with the current probe.
128 	 */
129 	prog_fd = syscall(__NR_bpf, BPF_PROG_LOAD, &attr, sizeof(attr));
130 	err = errno;
131 
132 	/* reset soft rlimit to its initial value */
133 	setrlimit(RLIMIT_MEMLOCK, &rlim_init);
134 
135 	if (prog_fd < 0)
136 		return err == EPERM;
137 
138 	close(prog_fd);
139 	return false;
140 }
141 
142 void set_max_rlimit(void)
143 {
144 	struct rlimit rinf = { RLIM_INFINITY, RLIM_INFINITY };
145 
146 	if (known_to_need_rlimit())
147 		setrlimit(RLIMIT_MEMLOCK, &rinf);
148 }
149 
150 static int
151 mnt_fs(const char *target, const char *type, char *buff, size_t bufflen)
152 {
153 	bool bind_done = false;
154 
155 	while (mount("", target, "none", MS_PRIVATE | MS_REC, NULL)) {
156 		if (errno != EINVAL || bind_done) {
157 			snprintf(buff, bufflen,
158 				 "mount --make-private %s failed: %s",
159 				 target, strerror(errno));
160 			return -1;
161 		}
162 
163 		if (mount(target, target, "none", MS_BIND, NULL)) {
164 			snprintf(buff, bufflen,
165 				 "mount --bind %s %s failed: %s",
166 				 target, target, strerror(errno));
167 			return -1;
168 		}
169 
170 		bind_done = true;
171 	}
172 
173 	if (mount(type, target, type, 0, "mode=0700")) {
174 		snprintf(buff, bufflen, "mount -t %s %s %s failed: %s",
175 			 type, type, target, strerror(errno));
176 		return -1;
177 	}
178 
179 	return 0;
180 }
181 
182 int mount_tracefs(const char *target)
183 {
184 	char err_str[ERR_MAX_LEN];
185 	int err;
186 
187 	err = mnt_fs(target, "tracefs", err_str, ERR_MAX_LEN);
188 	if (err) {
189 		err_str[ERR_MAX_LEN - 1] = '\0';
190 		p_err("can't mount tracefs: %s", err_str);
191 	}
192 
193 	return err;
194 }
195 
196 int open_obj_pinned(const char *path, bool quiet)
197 {
198 	char *pname;
199 	int fd = -1;
200 
201 	pname = strdup(path);
202 	if (!pname) {
203 		if (!quiet)
204 			p_err("mem alloc failed");
205 		goto out_ret;
206 	}
207 
208 	fd = bpf_obj_get(pname);
209 	if (fd < 0) {
210 		if (!quiet)
211 			p_err("bpf obj get (%s): %s", pname,
212 			      errno == EACCES && !is_bpffs(dirname(pname)) ?
213 			    "directory not in bpf file system (bpffs)" :
214 			    strerror(errno));
215 		goto out_free;
216 	}
217 
218 out_free:
219 	free(pname);
220 out_ret:
221 	return fd;
222 }
223 
224 int open_obj_pinned_any(const char *path, enum bpf_obj_type exp_type)
225 {
226 	enum bpf_obj_type type;
227 	int fd;
228 
229 	fd = open_obj_pinned(path, false);
230 	if (fd < 0)
231 		return -1;
232 
233 	type = get_fd_type(fd);
234 	if (type < 0) {
235 		close(fd);
236 		return type;
237 	}
238 	if (type != exp_type) {
239 		p_err("incorrect object type: %s", get_fd_type_name(type));
240 		close(fd);
241 		return -1;
242 	}
243 
244 	return fd;
245 }
246 
247 int mount_bpffs_for_pin(const char *name, bool is_dir)
248 {
249 	char err_str[ERR_MAX_LEN];
250 	char *file;
251 	char *dir;
252 	int err = 0;
253 
254 	if (is_dir && is_bpffs(name))
255 		return err;
256 
257 	file = malloc(strlen(name) + 1);
258 	if (!file) {
259 		p_err("mem alloc failed");
260 		return -1;
261 	}
262 
263 	strcpy(file, name);
264 	dir = dirname(file);
265 
266 	if (is_bpffs(dir))
267 		/* nothing to do if already mounted */
268 		goto out_free;
269 
270 	if (block_mount) {
271 		p_err("no BPF file system found, not mounting it due to --nomount option");
272 		err = -1;
273 		goto out_free;
274 	}
275 
276 	err = mnt_fs(dir, "bpf", err_str, ERR_MAX_LEN);
277 	if (err) {
278 		err_str[ERR_MAX_LEN - 1] = '\0';
279 		p_err("can't mount BPF file system to pin the object (%s): %s",
280 		      name, err_str);
281 	}
282 
283 out_free:
284 	free(file);
285 	return err;
286 }
287 
288 int do_pin_fd(int fd, const char *name)
289 {
290 	int err;
291 
292 	err = mount_bpffs_for_pin(name, false);
293 	if (err)
294 		return err;
295 
296 	err = bpf_obj_pin(fd, name);
297 	if (err)
298 		p_err("can't pin the object (%s): %s", name, strerror(errno));
299 
300 	return err;
301 }
302 
303 int do_pin_any(int argc, char **argv, int (*get_fd)(int *, char ***))
304 {
305 	int err;
306 	int fd;
307 
308 	if (!REQ_ARGS(3))
309 		return -EINVAL;
310 
311 	fd = get_fd(&argc, &argv);
312 	if (fd < 0)
313 		return fd;
314 
315 	err = do_pin_fd(fd, *argv);
316 
317 	close(fd);
318 	return err;
319 }
320 
321 const char *get_fd_type_name(enum bpf_obj_type type)
322 {
323 	static const char * const names[] = {
324 		[BPF_OBJ_UNKNOWN]	= "unknown",
325 		[BPF_OBJ_PROG]		= "prog",
326 		[BPF_OBJ_MAP]		= "map",
327 		[BPF_OBJ_LINK]		= "link",
328 	};
329 
330 	if (type < 0 || type >= ARRAY_SIZE(names) || !names[type])
331 		return names[BPF_OBJ_UNKNOWN];
332 
333 	return names[type];
334 }
335 
336 void get_prog_full_name(const struct bpf_prog_info *prog_info, int prog_fd,
337 			char *name_buff, size_t buff_len)
338 {
339 	const char *prog_name = prog_info->name;
340 	const struct btf_type *func_type;
341 	const struct bpf_func_info finfo = {};
342 	struct bpf_prog_info info = {};
343 	__u32 info_len = sizeof(info);
344 	struct btf *prog_btf = NULL;
345 
346 	if (buff_len <= BPF_OBJ_NAME_LEN ||
347 	    strlen(prog_info->name) < BPF_OBJ_NAME_LEN - 1)
348 		goto copy_name;
349 
350 	if (!prog_info->btf_id || prog_info->nr_func_info == 0)
351 		goto copy_name;
352 
353 	info.nr_func_info = 1;
354 	info.func_info_rec_size = prog_info->func_info_rec_size;
355 	if (info.func_info_rec_size > sizeof(finfo))
356 		info.func_info_rec_size = sizeof(finfo);
357 	info.func_info = ptr_to_u64(&finfo);
358 
359 	if (bpf_prog_get_info_by_fd(prog_fd, &info, &info_len))
360 		goto copy_name;
361 
362 	prog_btf = btf__load_from_kernel_by_id(info.btf_id);
363 	if (!prog_btf)
364 		goto copy_name;
365 
366 	func_type = btf__type_by_id(prog_btf, finfo.type_id);
367 	if (!func_type || !btf_is_func(func_type))
368 		goto copy_name;
369 
370 	prog_name = btf__name_by_offset(prog_btf, func_type->name_off);
371 
372 copy_name:
373 	snprintf(name_buff, buff_len, "%s", prog_name);
374 
375 	if (prog_btf)
376 		btf__free(prog_btf);
377 }
378 
379 int get_fd_type(int fd)
380 {
381 	char path[PATH_MAX];
382 	char buf[512];
383 	ssize_t n;
384 
385 	snprintf(path, sizeof(path), "/proc/self/fd/%d", fd);
386 
387 	n = readlink(path, buf, sizeof(buf));
388 	if (n < 0) {
389 		p_err("can't read link type: %s", strerror(errno));
390 		return -1;
391 	}
392 	if (n == sizeof(path)) {
393 		p_err("can't read link type: path too long!");
394 		return -1;
395 	}
396 
397 	if (strstr(buf, "bpf-map"))
398 		return BPF_OBJ_MAP;
399 	else if (strstr(buf, "bpf-prog"))
400 		return BPF_OBJ_PROG;
401 	else if (strstr(buf, "bpf-link"))
402 		return BPF_OBJ_LINK;
403 
404 	return BPF_OBJ_UNKNOWN;
405 }
406 
407 char *get_fdinfo(int fd, const char *key)
408 {
409 	char path[PATH_MAX];
410 	char *line = NULL;
411 	size_t line_n = 0;
412 	ssize_t n;
413 	FILE *fdi;
414 
415 	snprintf(path, sizeof(path), "/proc/self/fdinfo/%d", fd);
416 
417 	fdi = fopen(path, "r");
418 	if (!fdi)
419 		return NULL;
420 
421 	while ((n = getline(&line, &line_n, fdi)) > 0) {
422 		char *value;
423 		int len;
424 
425 		if (!strstr(line, key))
426 			continue;
427 
428 		fclose(fdi);
429 
430 		value = strchr(line, '\t');
431 		if (!value || !value[1]) {
432 			free(line);
433 			return NULL;
434 		}
435 		value++;
436 
437 		len = strlen(value);
438 		memmove(line, value, len);
439 		line[len - 1] = '\0';
440 
441 		return line;
442 	}
443 
444 	free(line);
445 	fclose(fdi);
446 	return NULL;
447 }
448 
449 void print_data_json(uint8_t *data, size_t len)
450 {
451 	unsigned int i;
452 
453 	jsonw_start_array(json_wtr);
454 	for (i = 0; i < len; i++)
455 		jsonw_printf(json_wtr, "%d", data[i]);
456 	jsonw_end_array(json_wtr);
457 }
458 
459 void print_hex_data_json(uint8_t *data, size_t len)
460 {
461 	unsigned int i;
462 
463 	jsonw_start_array(json_wtr);
464 	for (i = 0; i < len; i++)
465 		jsonw_printf(json_wtr, "\"0x%02hhx\"", data[i]);
466 	jsonw_end_array(json_wtr);
467 }
468 
469 /* extra params for nftw cb */
470 static struct hashmap *build_fn_table;
471 static enum bpf_obj_type build_fn_type;
472 
473 static int do_build_table_cb(const char *fpath, const struct stat *sb,
474 			     int typeflag, struct FTW *ftwbuf)
475 {
476 	struct bpf_prog_info pinned_info;
477 	__u32 len = sizeof(pinned_info);
478 	enum bpf_obj_type objtype;
479 	int fd, err = 0;
480 	char *path;
481 
482 	if (typeflag != FTW_F)
483 		goto out_ret;
484 
485 	fd = open_obj_pinned(fpath, true);
486 	if (fd < 0)
487 		goto out_ret;
488 
489 	objtype = get_fd_type(fd);
490 	if (objtype != build_fn_type)
491 		goto out_close;
492 
493 	memset(&pinned_info, 0, sizeof(pinned_info));
494 	if (bpf_prog_get_info_by_fd(fd, &pinned_info, &len))
495 		goto out_close;
496 
497 	path = strdup(fpath);
498 	if (!path) {
499 		err = -1;
500 		goto out_close;
501 	}
502 
503 	err = hashmap__append(build_fn_table, pinned_info.id, path);
504 	if (err) {
505 		p_err("failed to append entry to hashmap for ID %u, path '%s': %s",
506 		      pinned_info.id, path, strerror(errno));
507 		free(path);
508 		goto out_close;
509 	}
510 
511 out_close:
512 	close(fd);
513 out_ret:
514 	return err;
515 }
516 
517 int build_pinned_obj_table(struct hashmap *tab,
518 			   enum bpf_obj_type type)
519 {
520 	struct mntent *mntent = NULL;
521 	FILE *mntfile = NULL;
522 	int flags = FTW_PHYS;
523 	int nopenfd = 16;
524 	int err = 0;
525 
526 	mntfile = setmntent("/proc/mounts", "r");
527 	if (!mntfile)
528 		return -1;
529 
530 	build_fn_table = tab;
531 	build_fn_type = type;
532 
533 	while ((mntent = getmntent(mntfile))) {
534 		char *path = mntent->mnt_dir;
535 
536 		if (strncmp(mntent->mnt_type, "bpf", 3) != 0)
537 			continue;
538 		err = nftw(path, do_build_table_cb, nopenfd, flags);
539 		if (err)
540 			break;
541 	}
542 	fclose(mntfile);
543 	return err;
544 }
545 
546 void delete_pinned_obj_table(struct hashmap *map)
547 {
548 	struct hashmap_entry *entry;
549 	size_t bkt;
550 
551 	if (!map)
552 		return;
553 
554 	hashmap__for_each_entry(map, entry, bkt)
555 		free(entry->pvalue);
556 
557 	hashmap__free(map);
558 }
559 
560 unsigned int get_page_size(void)
561 {
562 	static int result;
563 
564 	if (!result)
565 		result = getpagesize();
566 	return result;
567 }
568 
569 unsigned int get_possible_cpus(void)
570 {
571 	int cpus = libbpf_num_possible_cpus();
572 
573 	if (cpus < 0) {
574 		p_err("Can't get # of possible cpus: %s", strerror(-cpus));
575 		exit(-1);
576 	}
577 	return cpus;
578 }
579 
580 static char *
581 ifindex_to_name_ns(__u32 ifindex, __u32 ns_dev, __u32 ns_ino, char *buf)
582 {
583 	struct stat st;
584 	int err;
585 
586 	err = stat("/proc/self/ns/net", &st);
587 	if (err) {
588 		p_err("Can't stat /proc/self: %s", strerror(errno));
589 		return NULL;
590 	}
591 
592 	if (st.st_dev != ns_dev || st.st_ino != ns_ino)
593 		return NULL;
594 
595 	return if_indextoname(ifindex, buf);
596 }
597 
598 static int read_sysfs_hex_int(char *path)
599 {
600 	char vendor_id_buf[8];
601 	int len;
602 	int fd;
603 
604 	fd = open(path, O_RDONLY);
605 	if (fd < 0) {
606 		p_err("Can't open %s: %s", path, strerror(errno));
607 		return -1;
608 	}
609 
610 	len = read(fd, vendor_id_buf, sizeof(vendor_id_buf));
611 	close(fd);
612 	if (len < 0) {
613 		p_err("Can't read %s: %s", path, strerror(errno));
614 		return -1;
615 	}
616 	if (len >= (int)sizeof(vendor_id_buf)) {
617 		p_err("Value in %s too long", path);
618 		return -1;
619 	}
620 
621 	vendor_id_buf[len] = 0;
622 
623 	return strtol(vendor_id_buf, NULL, 0);
624 }
625 
626 static int read_sysfs_netdev_hex_int(char *devname, const char *entry_name)
627 {
628 	char full_path[64];
629 
630 	snprintf(full_path, sizeof(full_path), "/sys/class/net/%s/device/%s",
631 		 devname, entry_name);
632 
633 	return read_sysfs_hex_int(full_path);
634 }
635 
636 const char *
637 ifindex_to_arch(__u32 ifindex, __u64 ns_dev, __u64 ns_ino, const char **opt)
638 {
639 	__maybe_unused int device_id;
640 	char devname[IF_NAMESIZE];
641 	int vendor_id;
642 
643 	if (!ifindex_to_name_ns(ifindex, ns_dev, ns_ino, devname)) {
644 		p_err("Can't get net device name for ifindex %d: %s", ifindex,
645 		      strerror(errno));
646 		return NULL;
647 	}
648 
649 	vendor_id = read_sysfs_netdev_hex_int(devname, "vendor");
650 	if (vendor_id < 0) {
651 		p_err("Can't get device vendor id for %s", devname);
652 		return NULL;
653 	}
654 
655 	switch (vendor_id) {
656 #ifdef HAVE_LIBBFD_SUPPORT
657 	case 0x19ee:
658 		device_id = read_sysfs_netdev_hex_int(devname, "device");
659 		if (device_id != 0x4000 &&
660 		    device_id != 0x6000 &&
661 		    device_id != 0x6003)
662 			p_info("Unknown NFP device ID, assuming it is NFP-6xxx arch");
663 		*opt = "ctx4";
664 		return "NFP-6xxx";
665 #endif /* HAVE_LIBBFD_SUPPORT */
666 	/* No NFP support in LLVM, we have no valid triple to return. */
667 	default:
668 		p_err("Can't get arch name for device vendor id 0x%04x",
669 		      vendor_id);
670 		return NULL;
671 	}
672 }
673 
674 void print_dev_plain(__u32 ifindex, __u64 ns_dev, __u64 ns_inode)
675 {
676 	char name[IF_NAMESIZE];
677 
678 	if (!ifindex)
679 		return;
680 
681 	printf("  offloaded_to ");
682 	if (ifindex_to_name_ns(ifindex, ns_dev, ns_inode, name))
683 		printf("%s", name);
684 	else
685 		printf("ifindex %u ns_dev %llu ns_ino %llu",
686 		       ifindex, ns_dev, ns_inode);
687 }
688 
689 void print_dev_json(__u32 ifindex, __u64 ns_dev, __u64 ns_inode)
690 {
691 	char name[IF_NAMESIZE];
692 
693 	if (!ifindex)
694 		return;
695 
696 	jsonw_name(json_wtr, "dev");
697 	jsonw_start_object(json_wtr);
698 	jsonw_uint_field(json_wtr, "ifindex", ifindex);
699 	jsonw_uint_field(json_wtr, "ns_dev", ns_dev);
700 	jsonw_uint_field(json_wtr, "ns_inode", ns_inode);
701 	if (ifindex_to_name_ns(ifindex, ns_dev, ns_inode, name))
702 		jsonw_string_field(json_wtr, "ifname", name);
703 	jsonw_end_object(json_wtr);
704 }
705 
706 int parse_u32_arg(int *argc, char ***argv, __u32 *val, const char *what)
707 {
708 	char *endptr;
709 
710 	NEXT_ARGP();
711 
712 	if (*val) {
713 		p_err("%s already specified", what);
714 		return -1;
715 	}
716 
717 	*val = strtoul(**argv, &endptr, 0);
718 	if (*endptr) {
719 		p_err("can't parse %s as %s", **argv, what);
720 		return -1;
721 	}
722 	NEXT_ARGP();
723 
724 	return 0;
725 }
726 
727 int __printf(2, 0)
728 print_all_levels(__maybe_unused enum libbpf_print_level level,
729 		 const char *format, va_list args)
730 {
731 	return vfprintf(stderr, format, args);
732 }
733 
734 static int prog_fd_by_nametag(void *nametag, int **fds, bool tag)
735 {
736 	char prog_name[MAX_PROG_FULL_NAME];
737 	unsigned int id = 0;
738 	int fd, nb_fds = 0;
739 	void *tmp;
740 	int err;
741 
742 	while (true) {
743 		struct bpf_prog_info info = {};
744 		__u32 len = sizeof(info);
745 
746 		err = bpf_prog_get_next_id(id, &id);
747 		if (err) {
748 			if (errno != ENOENT) {
749 				p_err("%s", strerror(errno));
750 				goto err_close_fds;
751 			}
752 			return nb_fds;
753 		}
754 
755 		fd = bpf_prog_get_fd_by_id(id);
756 		if (fd < 0) {
757 			p_err("can't get prog by id (%u): %s",
758 			      id, strerror(errno));
759 			goto err_close_fds;
760 		}
761 
762 		err = bpf_prog_get_info_by_fd(fd, &info, &len);
763 		if (err) {
764 			p_err("can't get prog info (%u): %s",
765 			      id, strerror(errno));
766 			goto err_close_fd;
767 		}
768 
769 		if (tag && memcmp(nametag, info.tag, BPF_TAG_SIZE)) {
770 			close(fd);
771 			continue;
772 		}
773 
774 		if (!tag) {
775 			get_prog_full_name(&info, fd, prog_name,
776 					   sizeof(prog_name));
777 			if (strncmp(nametag, prog_name, sizeof(prog_name))) {
778 				close(fd);
779 				continue;
780 			}
781 		}
782 
783 		if (nb_fds > 0) {
784 			tmp = realloc(*fds, (nb_fds + 1) * sizeof(int));
785 			if (!tmp) {
786 				p_err("failed to realloc");
787 				goto err_close_fd;
788 			}
789 			*fds = tmp;
790 		}
791 		(*fds)[nb_fds++] = fd;
792 	}
793 
794 err_close_fd:
795 	close(fd);
796 err_close_fds:
797 	while (--nb_fds >= 0)
798 		close((*fds)[nb_fds]);
799 	return -1;
800 }
801 
802 int prog_parse_fds(int *argc, char ***argv, int **fds)
803 {
804 	if (is_prefix(**argv, "id")) {
805 		unsigned int id;
806 		char *endptr;
807 
808 		NEXT_ARGP();
809 
810 		id = strtoul(**argv, &endptr, 0);
811 		if (*endptr) {
812 			p_err("can't parse %s as ID", **argv);
813 			return -1;
814 		}
815 		NEXT_ARGP();
816 
817 		(*fds)[0] = bpf_prog_get_fd_by_id(id);
818 		if ((*fds)[0] < 0) {
819 			p_err("get by id (%u): %s", id, strerror(errno));
820 			return -1;
821 		}
822 		return 1;
823 	} else if (is_prefix(**argv, "tag")) {
824 		unsigned char tag[BPF_TAG_SIZE];
825 
826 		NEXT_ARGP();
827 
828 		if (sscanf(**argv, BPF_TAG_FMT, tag, tag + 1, tag + 2,
829 			   tag + 3, tag + 4, tag + 5, tag + 6, tag + 7)
830 		    != BPF_TAG_SIZE) {
831 			p_err("can't parse tag");
832 			return -1;
833 		}
834 		NEXT_ARGP();
835 
836 		return prog_fd_by_nametag(tag, fds, true);
837 	} else if (is_prefix(**argv, "name")) {
838 		char *name;
839 
840 		NEXT_ARGP();
841 
842 		name = **argv;
843 		if (strlen(name) > MAX_PROG_FULL_NAME - 1) {
844 			p_err("can't parse name");
845 			return -1;
846 		}
847 		NEXT_ARGP();
848 
849 		return prog_fd_by_nametag(name, fds, false);
850 	} else if (is_prefix(**argv, "pinned")) {
851 		char *path;
852 
853 		NEXT_ARGP();
854 
855 		path = **argv;
856 		NEXT_ARGP();
857 
858 		(*fds)[0] = open_obj_pinned_any(path, BPF_OBJ_PROG);
859 		if ((*fds)[0] < 0)
860 			return -1;
861 		return 1;
862 	}
863 
864 	p_err("expected 'id', 'tag', 'name' or 'pinned', got: '%s'?", **argv);
865 	return -1;
866 }
867 
868 int prog_parse_fd(int *argc, char ***argv)
869 {
870 	int *fds = NULL;
871 	int nb_fds, fd;
872 
873 	fds = malloc(sizeof(int));
874 	if (!fds) {
875 		p_err("mem alloc failed");
876 		return -1;
877 	}
878 	nb_fds = prog_parse_fds(argc, argv, &fds);
879 	if (nb_fds != 1) {
880 		if (nb_fds > 1) {
881 			p_err("several programs match this handle");
882 			while (nb_fds--)
883 				close(fds[nb_fds]);
884 		}
885 		fd = -1;
886 		goto exit_free;
887 	}
888 
889 	fd = fds[0];
890 exit_free:
891 	free(fds);
892 	return fd;
893 }
894 
895 static int map_fd_by_name(char *name, int **fds)
896 {
897 	unsigned int id = 0;
898 	int fd, nb_fds = 0;
899 	void *tmp;
900 	int err;
901 
902 	while (true) {
903 		struct bpf_map_info info = {};
904 		__u32 len = sizeof(info);
905 
906 		err = bpf_map_get_next_id(id, &id);
907 		if (err) {
908 			if (errno != ENOENT) {
909 				p_err("%s", strerror(errno));
910 				goto err_close_fds;
911 			}
912 			return nb_fds;
913 		}
914 
915 		fd = bpf_map_get_fd_by_id(id);
916 		if (fd < 0) {
917 			p_err("can't get map by id (%u): %s",
918 			      id, strerror(errno));
919 			goto err_close_fds;
920 		}
921 
922 		err = bpf_map_get_info_by_fd(fd, &info, &len);
923 		if (err) {
924 			p_err("can't get map info (%u): %s",
925 			      id, strerror(errno));
926 			goto err_close_fd;
927 		}
928 
929 		if (strncmp(name, info.name, BPF_OBJ_NAME_LEN)) {
930 			close(fd);
931 			continue;
932 		}
933 
934 		if (nb_fds > 0) {
935 			tmp = realloc(*fds, (nb_fds + 1) * sizeof(int));
936 			if (!tmp) {
937 				p_err("failed to realloc");
938 				goto err_close_fd;
939 			}
940 			*fds = tmp;
941 		}
942 		(*fds)[nb_fds++] = fd;
943 	}
944 
945 err_close_fd:
946 	close(fd);
947 err_close_fds:
948 	while (--nb_fds >= 0)
949 		close((*fds)[nb_fds]);
950 	return -1;
951 }
952 
953 int map_parse_fds(int *argc, char ***argv, int **fds)
954 {
955 	if (is_prefix(**argv, "id")) {
956 		unsigned int id;
957 		char *endptr;
958 
959 		NEXT_ARGP();
960 
961 		id = strtoul(**argv, &endptr, 0);
962 		if (*endptr) {
963 			p_err("can't parse %s as ID", **argv);
964 			return -1;
965 		}
966 		NEXT_ARGP();
967 
968 		(*fds)[0] = bpf_map_get_fd_by_id(id);
969 		if ((*fds)[0] < 0) {
970 			p_err("get map by id (%u): %s", id, strerror(errno));
971 			return -1;
972 		}
973 		return 1;
974 	} else if (is_prefix(**argv, "name")) {
975 		char *name;
976 
977 		NEXT_ARGP();
978 
979 		name = **argv;
980 		if (strlen(name) > BPF_OBJ_NAME_LEN - 1) {
981 			p_err("can't parse name");
982 			return -1;
983 		}
984 		NEXT_ARGP();
985 
986 		return map_fd_by_name(name, fds);
987 	} else if (is_prefix(**argv, "pinned")) {
988 		char *path;
989 
990 		NEXT_ARGP();
991 
992 		path = **argv;
993 		NEXT_ARGP();
994 
995 		(*fds)[0] = open_obj_pinned_any(path, BPF_OBJ_MAP);
996 		if ((*fds)[0] < 0)
997 			return -1;
998 		return 1;
999 	}
1000 
1001 	p_err("expected 'id', 'name' or 'pinned', got: '%s'?", **argv);
1002 	return -1;
1003 }
1004 
1005 int map_parse_fd(int *argc, char ***argv)
1006 {
1007 	int *fds = NULL;
1008 	int nb_fds, fd;
1009 
1010 	fds = malloc(sizeof(int));
1011 	if (!fds) {
1012 		p_err("mem alloc failed");
1013 		return -1;
1014 	}
1015 	nb_fds = map_parse_fds(argc, argv, &fds);
1016 	if (nb_fds != 1) {
1017 		if (nb_fds > 1) {
1018 			p_err("several maps match this handle");
1019 			while (nb_fds--)
1020 				close(fds[nb_fds]);
1021 		}
1022 		fd = -1;
1023 		goto exit_free;
1024 	}
1025 
1026 	fd = fds[0];
1027 exit_free:
1028 	free(fds);
1029 	return fd;
1030 }
1031 
1032 int map_parse_fd_and_info(int *argc, char ***argv, struct bpf_map_info *info,
1033 			  __u32 *info_len)
1034 {
1035 	int err;
1036 	int fd;
1037 
1038 	fd = map_parse_fd(argc, argv);
1039 	if (fd < 0)
1040 		return -1;
1041 
1042 	err = bpf_map_get_info_by_fd(fd, info, info_len);
1043 	if (err) {
1044 		p_err("can't get map info: %s", strerror(errno));
1045 		close(fd);
1046 		return err;
1047 	}
1048 
1049 	return fd;
1050 }
1051 
1052 size_t hash_fn_for_key_as_id(long key, void *ctx)
1053 {
1054 	return key;
1055 }
1056 
1057 bool equal_fn_for_key_as_id(long k1, long k2, void *ctx)
1058 {
1059 	return k1 == k2;
1060 }
1061 
1062 const char *bpf_attach_type_input_str(enum bpf_attach_type t)
1063 {
1064 	switch (t) {
1065 	case BPF_CGROUP_INET_INGRESS:		return "ingress";
1066 	case BPF_CGROUP_INET_EGRESS:		return "egress";
1067 	case BPF_CGROUP_INET_SOCK_CREATE:	return "sock_create";
1068 	case BPF_CGROUP_INET_SOCK_RELEASE:	return "sock_release";
1069 	case BPF_CGROUP_SOCK_OPS:		return "sock_ops";
1070 	case BPF_CGROUP_DEVICE:			return "device";
1071 	case BPF_CGROUP_INET4_BIND:		return "bind4";
1072 	case BPF_CGROUP_INET6_BIND:		return "bind6";
1073 	case BPF_CGROUP_INET4_CONNECT:		return "connect4";
1074 	case BPF_CGROUP_INET6_CONNECT:		return "connect6";
1075 	case BPF_CGROUP_INET4_POST_BIND:	return "post_bind4";
1076 	case BPF_CGROUP_INET6_POST_BIND:	return "post_bind6";
1077 	case BPF_CGROUP_INET4_GETPEERNAME:	return "getpeername4";
1078 	case BPF_CGROUP_INET6_GETPEERNAME:	return "getpeername6";
1079 	case BPF_CGROUP_INET4_GETSOCKNAME:	return "getsockname4";
1080 	case BPF_CGROUP_INET6_GETSOCKNAME:	return "getsockname6";
1081 	case BPF_CGROUP_UDP4_SENDMSG:		return "sendmsg4";
1082 	case BPF_CGROUP_UDP6_SENDMSG:		return "sendmsg6";
1083 	case BPF_CGROUP_SYSCTL:			return "sysctl";
1084 	case BPF_CGROUP_UDP4_RECVMSG:		return "recvmsg4";
1085 	case BPF_CGROUP_UDP6_RECVMSG:		return "recvmsg6";
1086 	case BPF_CGROUP_GETSOCKOPT:		return "getsockopt";
1087 	case BPF_CGROUP_SETSOCKOPT:		return "setsockopt";
1088 	case BPF_TRACE_RAW_TP:			return "raw_tp";
1089 	case BPF_TRACE_FENTRY:			return "fentry";
1090 	case BPF_TRACE_FEXIT:			return "fexit";
1091 	case BPF_MODIFY_RETURN:			return "mod_ret";
1092 	case BPF_SK_REUSEPORT_SELECT:		return "sk_skb_reuseport_select";
1093 	case BPF_SK_REUSEPORT_SELECT_OR_MIGRATE:	return "sk_skb_reuseport_select_or_migrate";
1094 	default:	return libbpf_bpf_attach_type_str(t);
1095 	}
1096 }
1097 
1098 int pathname_concat(char *buf, int buf_sz, const char *path,
1099 		    const char *name)
1100 {
1101 	int len;
1102 
1103 	len = snprintf(buf, buf_sz, "%s/%s", path, name);
1104 	if (len < 0)
1105 		return -EINVAL;
1106 	if (len >= buf_sz)
1107 		return -ENAMETOOLONG;
1108 
1109 	return 0;
1110 }
1111