xref: /linux/tools/bpf/bpftool/common.c (revision 4ac6d90867a4de2e12117e755dbd76e08d88697f)
1 // SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
2 /* Copyright (C) 2017-2018 Netronome Systems, Inc. */
3 
4 #define _GNU_SOURCE
5 #include <ctype.h>
6 #include <errno.h>
7 #include <fcntl.h>
8 #include <ftw.h>
9 #include <libgen.h>
10 #include <mntent.h>
11 #include <stdbool.h>
12 #include <stdio.h>
13 #include <stdlib.h>
14 #include <string.h>
15 #include <unistd.h>
16 #include <linux/limits.h>
17 #include <linux/magic.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 <bpf/bpf.h>
25 #include <bpf/libbpf.h> /* libbpf_num_possible_cpus */
26 
27 #include "main.h"
28 
29 #ifndef BPF_FS_MAGIC
30 #define BPF_FS_MAGIC		0xcafe4a11
31 #endif
32 
33 const char * const attach_type_name[__MAX_BPF_ATTACH_TYPE] = {
34 	[BPF_CGROUP_INET_INGRESS]	= "ingress",
35 	[BPF_CGROUP_INET_EGRESS]	= "egress",
36 	[BPF_CGROUP_INET_SOCK_CREATE]	= "sock_create",
37 	[BPF_CGROUP_INET_SOCK_RELEASE]	= "sock_release",
38 	[BPF_CGROUP_SOCK_OPS]		= "sock_ops",
39 	[BPF_CGROUP_DEVICE]		= "device",
40 	[BPF_CGROUP_INET4_BIND]		= "bind4",
41 	[BPF_CGROUP_INET6_BIND]		= "bind6",
42 	[BPF_CGROUP_INET4_CONNECT]	= "connect4",
43 	[BPF_CGROUP_INET6_CONNECT]	= "connect6",
44 	[BPF_CGROUP_INET4_POST_BIND]	= "post_bind4",
45 	[BPF_CGROUP_INET6_POST_BIND]	= "post_bind6",
46 	[BPF_CGROUP_INET4_GETPEERNAME]	= "getpeername4",
47 	[BPF_CGROUP_INET6_GETPEERNAME]	= "getpeername6",
48 	[BPF_CGROUP_INET4_GETSOCKNAME]	= "getsockname4",
49 	[BPF_CGROUP_INET6_GETSOCKNAME]	= "getsockname6",
50 	[BPF_CGROUP_UDP4_SENDMSG]	= "sendmsg4",
51 	[BPF_CGROUP_UDP6_SENDMSG]	= "sendmsg6",
52 	[BPF_CGROUP_SYSCTL]		= "sysctl",
53 	[BPF_CGROUP_UDP4_RECVMSG]	= "recvmsg4",
54 	[BPF_CGROUP_UDP6_RECVMSG]	= "recvmsg6",
55 	[BPF_CGROUP_GETSOCKOPT]		= "getsockopt",
56 	[BPF_CGROUP_SETSOCKOPT]		= "setsockopt",
57 
58 	[BPF_SK_SKB_STREAM_PARSER]	= "sk_skb_stream_parser",
59 	[BPF_SK_SKB_STREAM_VERDICT]	= "sk_skb_stream_verdict",
60 	[BPF_SK_SKB_VERDICT]		= "sk_skb_verdict",
61 	[BPF_SK_MSG_VERDICT]		= "sk_msg_verdict",
62 	[BPF_LIRC_MODE2]		= "lirc_mode2",
63 	[BPF_FLOW_DISSECTOR]		= "flow_dissector",
64 	[BPF_TRACE_RAW_TP]		= "raw_tp",
65 	[BPF_TRACE_FENTRY]		= "fentry",
66 	[BPF_TRACE_FEXIT]		= "fexit",
67 	[BPF_MODIFY_RETURN]		= "mod_ret",
68 	[BPF_LSM_MAC]			= "lsm_mac",
69 	[BPF_SK_LOOKUP]			= "sk_lookup",
70 	[BPF_TRACE_ITER]		= "trace_iter",
71 	[BPF_XDP_DEVMAP]		= "xdp_devmap",
72 	[BPF_XDP_CPUMAP]		= "xdp_cpumap",
73 	[BPF_XDP]			= "xdp",
74 	[BPF_SK_REUSEPORT_SELECT]	= "sk_skb_reuseport_select",
75 	[BPF_SK_REUSEPORT_SELECT_OR_MIGRATE]	= "sk_skb_reuseport_select_or_migrate",
76 };
77 
78 void p_err(const char *fmt, ...)
79 {
80 	va_list ap;
81 
82 	va_start(ap, fmt);
83 	if (json_output) {
84 		jsonw_start_object(json_wtr);
85 		jsonw_name(json_wtr, "error");
86 		jsonw_vprintf_enquote(json_wtr, fmt, ap);
87 		jsonw_end_object(json_wtr);
88 	} else {
89 		fprintf(stderr, "Error: ");
90 		vfprintf(stderr, fmt, ap);
91 		fprintf(stderr, "\n");
92 	}
93 	va_end(ap);
94 }
95 
96 void p_info(const char *fmt, ...)
97 {
98 	va_list ap;
99 
100 	if (json_output)
101 		return;
102 
103 	va_start(ap, fmt);
104 	vfprintf(stderr, fmt, ap);
105 	fprintf(stderr, "\n");
106 	va_end(ap);
107 }
108 
109 static bool is_bpffs(char *path)
110 {
111 	struct statfs st_fs;
112 
113 	if (statfs(path, &st_fs) < 0)
114 		return false;
115 
116 	return (unsigned long)st_fs.f_type == BPF_FS_MAGIC;
117 }
118 
119 void set_max_rlimit(void)
120 {
121 	struct rlimit rinf = { RLIM_INFINITY, RLIM_INFINITY };
122 
123 	setrlimit(RLIMIT_MEMLOCK, &rinf);
124 }
125 
126 static int
127 mnt_fs(const char *target, const char *type, char *buff, size_t bufflen)
128 {
129 	bool bind_done = false;
130 
131 	while (mount("", target, "none", MS_PRIVATE | MS_REC, NULL)) {
132 		if (errno != EINVAL || bind_done) {
133 			snprintf(buff, bufflen,
134 				 "mount --make-private %s failed: %s",
135 				 target, strerror(errno));
136 			return -1;
137 		}
138 
139 		if (mount(target, target, "none", MS_BIND, NULL)) {
140 			snprintf(buff, bufflen,
141 				 "mount --bind %s %s failed: %s",
142 				 target, target, strerror(errno));
143 			return -1;
144 		}
145 
146 		bind_done = true;
147 	}
148 
149 	if (mount(type, target, type, 0, "mode=0700")) {
150 		snprintf(buff, bufflen, "mount -t %s %s %s failed: %s",
151 			 type, type, target, strerror(errno));
152 		return -1;
153 	}
154 
155 	return 0;
156 }
157 
158 int mount_tracefs(const char *target)
159 {
160 	char err_str[ERR_MAX_LEN];
161 	int err;
162 
163 	err = mnt_fs(target, "tracefs", err_str, ERR_MAX_LEN);
164 	if (err) {
165 		err_str[ERR_MAX_LEN - 1] = '\0';
166 		p_err("can't mount tracefs: %s", err_str);
167 	}
168 
169 	return err;
170 }
171 
172 int open_obj_pinned(const char *path, bool quiet)
173 {
174 	char *pname;
175 	int fd = -1;
176 
177 	pname = strdup(path);
178 	if (!pname) {
179 		if (!quiet)
180 			p_err("mem alloc failed");
181 		goto out_ret;
182 	}
183 
184 	fd = bpf_obj_get(pname);
185 	if (fd < 0) {
186 		if (!quiet)
187 			p_err("bpf obj get (%s): %s", pname,
188 			      errno == EACCES && !is_bpffs(dirname(pname)) ?
189 			    "directory not in bpf file system (bpffs)" :
190 			    strerror(errno));
191 		goto out_free;
192 	}
193 
194 out_free:
195 	free(pname);
196 out_ret:
197 	return fd;
198 }
199 
200 int open_obj_pinned_any(const char *path, enum bpf_obj_type exp_type)
201 {
202 	enum bpf_obj_type type;
203 	int fd;
204 
205 	fd = open_obj_pinned(path, false);
206 	if (fd < 0)
207 		return -1;
208 
209 	type = get_fd_type(fd);
210 	if (type < 0) {
211 		close(fd);
212 		return type;
213 	}
214 	if (type != exp_type) {
215 		p_err("incorrect object type: %s", get_fd_type_name(type));
216 		close(fd);
217 		return -1;
218 	}
219 
220 	return fd;
221 }
222 
223 int mount_bpffs_for_pin(const char *name)
224 {
225 	char err_str[ERR_MAX_LEN];
226 	char *file;
227 	char *dir;
228 	int err = 0;
229 
230 	file = malloc(strlen(name) + 1);
231 	if (!file) {
232 		p_err("mem alloc failed");
233 		return -1;
234 	}
235 
236 	strcpy(file, name);
237 	dir = dirname(file);
238 
239 	if (is_bpffs(dir))
240 		/* nothing to do if already mounted */
241 		goto out_free;
242 
243 	if (block_mount) {
244 		p_err("no BPF file system found, not mounting it due to --nomount option");
245 		err = -1;
246 		goto out_free;
247 	}
248 
249 	err = mnt_fs(dir, "bpf", err_str, ERR_MAX_LEN);
250 	if (err) {
251 		err_str[ERR_MAX_LEN - 1] = '\0';
252 		p_err("can't mount BPF file system to pin the object (%s): %s",
253 		      name, err_str);
254 	}
255 
256 out_free:
257 	free(file);
258 	return err;
259 }
260 
261 int do_pin_fd(int fd, const char *name)
262 {
263 	int err;
264 
265 	err = mount_bpffs_for_pin(name);
266 	if (err)
267 		return err;
268 
269 	err = bpf_obj_pin(fd, name);
270 	if (err)
271 		p_err("can't pin the object (%s): %s", name, strerror(errno));
272 
273 	return err;
274 }
275 
276 int do_pin_any(int argc, char **argv, int (*get_fd)(int *, char ***))
277 {
278 	int err;
279 	int fd;
280 
281 	fd = get_fd(&argc, &argv);
282 	if (fd < 0)
283 		return fd;
284 
285 	err = do_pin_fd(fd, *argv);
286 
287 	close(fd);
288 	return err;
289 }
290 
291 const char *get_fd_type_name(enum bpf_obj_type type)
292 {
293 	static const char * const names[] = {
294 		[BPF_OBJ_UNKNOWN]	= "unknown",
295 		[BPF_OBJ_PROG]		= "prog",
296 		[BPF_OBJ_MAP]		= "map",
297 	};
298 
299 	if (type < 0 || type >= ARRAY_SIZE(names) || !names[type])
300 		return names[BPF_OBJ_UNKNOWN];
301 
302 	return names[type];
303 }
304 
305 int get_fd_type(int fd)
306 {
307 	char path[PATH_MAX];
308 	char buf[512];
309 	ssize_t n;
310 
311 	snprintf(path, sizeof(path), "/proc/self/fd/%d", fd);
312 
313 	n = readlink(path, buf, sizeof(buf));
314 	if (n < 0) {
315 		p_err("can't read link type: %s", strerror(errno));
316 		return -1;
317 	}
318 	if (n == sizeof(path)) {
319 		p_err("can't read link type: path too long!");
320 		return -1;
321 	}
322 
323 	if (strstr(buf, "bpf-map"))
324 		return BPF_OBJ_MAP;
325 	else if (strstr(buf, "bpf-prog"))
326 		return BPF_OBJ_PROG;
327 	else if (strstr(buf, "bpf-link"))
328 		return BPF_OBJ_LINK;
329 
330 	return BPF_OBJ_UNKNOWN;
331 }
332 
333 char *get_fdinfo(int fd, const char *key)
334 {
335 	char path[PATH_MAX];
336 	char *line = NULL;
337 	size_t line_n = 0;
338 	ssize_t n;
339 	FILE *fdi;
340 
341 	snprintf(path, sizeof(path), "/proc/self/fdinfo/%d", fd);
342 
343 	fdi = fopen(path, "r");
344 	if (!fdi)
345 		return NULL;
346 
347 	while ((n = getline(&line, &line_n, fdi)) > 0) {
348 		char *value;
349 		int len;
350 
351 		if (!strstr(line, key))
352 			continue;
353 
354 		fclose(fdi);
355 
356 		value = strchr(line, '\t');
357 		if (!value || !value[1]) {
358 			free(line);
359 			return NULL;
360 		}
361 		value++;
362 
363 		len = strlen(value);
364 		memmove(line, value, len);
365 		line[len - 1] = '\0';
366 
367 		return line;
368 	}
369 
370 	free(line);
371 	fclose(fdi);
372 	return NULL;
373 }
374 
375 void print_data_json(uint8_t *data, size_t len)
376 {
377 	unsigned int i;
378 
379 	jsonw_start_array(json_wtr);
380 	for (i = 0; i < len; i++)
381 		jsonw_printf(json_wtr, "%d", data[i]);
382 	jsonw_end_array(json_wtr);
383 }
384 
385 void print_hex_data_json(uint8_t *data, size_t len)
386 {
387 	unsigned int i;
388 
389 	jsonw_start_array(json_wtr);
390 	for (i = 0; i < len; i++)
391 		jsonw_printf(json_wtr, "\"0x%02hhx\"", data[i]);
392 	jsonw_end_array(json_wtr);
393 }
394 
395 /* extra params for nftw cb */
396 static struct pinned_obj_table *build_fn_table;
397 static enum bpf_obj_type build_fn_type;
398 
399 static int do_build_table_cb(const char *fpath, const struct stat *sb,
400 			     int typeflag, struct FTW *ftwbuf)
401 {
402 	struct bpf_prog_info pinned_info;
403 	__u32 len = sizeof(pinned_info);
404 	struct pinned_obj *obj_node;
405 	enum bpf_obj_type objtype;
406 	int fd, err = 0;
407 
408 	if (typeflag != FTW_F)
409 		goto out_ret;
410 
411 	fd = open_obj_pinned(fpath, true);
412 	if (fd < 0)
413 		goto out_ret;
414 
415 	objtype = get_fd_type(fd);
416 	if (objtype != build_fn_type)
417 		goto out_close;
418 
419 	memset(&pinned_info, 0, sizeof(pinned_info));
420 	if (bpf_obj_get_info_by_fd(fd, &pinned_info, &len))
421 		goto out_close;
422 
423 	obj_node = calloc(1, sizeof(*obj_node));
424 	if (!obj_node) {
425 		err = -1;
426 		goto out_close;
427 	}
428 
429 	obj_node->id = pinned_info.id;
430 	obj_node->path = strdup(fpath);
431 	if (!obj_node->path) {
432 		err = -1;
433 		free(obj_node);
434 		goto out_close;
435 	}
436 
437 	hash_add(build_fn_table->table, &obj_node->hash, obj_node->id);
438 out_close:
439 	close(fd);
440 out_ret:
441 	return err;
442 }
443 
444 int build_pinned_obj_table(struct pinned_obj_table *tab,
445 			   enum bpf_obj_type type)
446 {
447 	struct mntent *mntent = NULL;
448 	FILE *mntfile = NULL;
449 	int flags = FTW_PHYS;
450 	int nopenfd = 16;
451 	int err = 0;
452 
453 	mntfile = setmntent("/proc/mounts", "r");
454 	if (!mntfile)
455 		return -1;
456 
457 	build_fn_table = tab;
458 	build_fn_type = type;
459 
460 	while ((mntent = getmntent(mntfile))) {
461 		char *path = mntent->mnt_dir;
462 
463 		if (strncmp(mntent->mnt_type, "bpf", 3) != 0)
464 			continue;
465 		err = nftw(path, do_build_table_cb, nopenfd, flags);
466 		if (err)
467 			break;
468 	}
469 	fclose(mntfile);
470 	return err;
471 }
472 
473 void delete_pinned_obj_table(struct pinned_obj_table *tab)
474 {
475 	struct pinned_obj *obj;
476 	struct hlist_node *tmp;
477 	unsigned int bkt;
478 
479 	hash_for_each_safe(tab->table, bkt, tmp, obj, hash) {
480 		hash_del(&obj->hash);
481 		free(obj->path);
482 		free(obj);
483 	}
484 }
485 
486 unsigned int get_page_size(void)
487 {
488 	static int result;
489 
490 	if (!result)
491 		result = getpagesize();
492 	return result;
493 }
494 
495 unsigned int get_possible_cpus(void)
496 {
497 	int cpus = libbpf_num_possible_cpus();
498 
499 	if (cpus < 0) {
500 		p_err("Can't get # of possible cpus: %s", strerror(-cpus));
501 		exit(-1);
502 	}
503 	return cpus;
504 }
505 
506 static char *
507 ifindex_to_name_ns(__u32 ifindex, __u32 ns_dev, __u32 ns_ino, char *buf)
508 {
509 	struct stat st;
510 	int err;
511 
512 	err = stat("/proc/self/ns/net", &st);
513 	if (err) {
514 		p_err("Can't stat /proc/self: %s", strerror(errno));
515 		return NULL;
516 	}
517 
518 	if (st.st_dev != ns_dev || st.st_ino != ns_ino)
519 		return NULL;
520 
521 	return if_indextoname(ifindex, buf);
522 }
523 
524 static int read_sysfs_hex_int(char *path)
525 {
526 	char vendor_id_buf[8];
527 	int len;
528 	int fd;
529 
530 	fd = open(path, O_RDONLY);
531 	if (fd < 0) {
532 		p_err("Can't open %s: %s", path, strerror(errno));
533 		return -1;
534 	}
535 
536 	len = read(fd, vendor_id_buf, sizeof(vendor_id_buf));
537 	close(fd);
538 	if (len < 0) {
539 		p_err("Can't read %s: %s", path, strerror(errno));
540 		return -1;
541 	}
542 	if (len >= (int)sizeof(vendor_id_buf)) {
543 		p_err("Value in %s too long", path);
544 		return -1;
545 	}
546 
547 	vendor_id_buf[len] = 0;
548 
549 	return strtol(vendor_id_buf, NULL, 0);
550 }
551 
552 static int read_sysfs_netdev_hex_int(char *devname, const char *entry_name)
553 {
554 	char full_path[64];
555 
556 	snprintf(full_path, sizeof(full_path), "/sys/class/net/%s/device/%s",
557 		 devname, entry_name);
558 
559 	return read_sysfs_hex_int(full_path);
560 }
561 
562 const char *
563 ifindex_to_bfd_params(__u32 ifindex, __u64 ns_dev, __u64 ns_ino,
564 		      const char **opt)
565 {
566 	char devname[IF_NAMESIZE];
567 	int vendor_id;
568 	int device_id;
569 
570 	if (!ifindex_to_name_ns(ifindex, ns_dev, ns_ino, devname)) {
571 		p_err("Can't get net device name for ifindex %d: %s", ifindex,
572 		      strerror(errno));
573 		return NULL;
574 	}
575 
576 	vendor_id = read_sysfs_netdev_hex_int(devname, "vendor");
577 	if (vendor_id < 0) {
578 		p_err("Can't get device vendor id for %s", devname);
579 		return NULL;
580 	}
581 
582 	switch (vendor_id) {
583 	case 0x19ee:
584 		device_id = read_sysfs_netdev_hex_int(devname, "device");
585 		if (device_id != 0x4000 &&
586 		    device_id != 0x6000 &&
587 		    device_id != 0x6003)
588 			p_info("Unknown NFP device ID, assuming it is NFP-6xxx arch");
589 		*opt = "ctx4";
590 		return "NFP-6xxx";
591 	default:
592 		p_err("Can't get bfd arch name for device vendor id 0x%04x",
593 		      vendor_id);
594 		return NULL;
595 	}
596 }
597 
598 void print_dev_plain(__u32 ifindex, __u64 ns_dev, __u64 ns_inode)
599 {
600 	char name[IF_NAMESIZE];
601 
602 	if (!ifindex)
603 		return;
604 
605 	printf("  offloaded_to ");
606 	if (ifindex_to_name_ns(ifindex, ns_dev, ns_inode, name))
607 		printf("%s", name);
608 	else
609 		printf("ifindex %u ns_dev %llu ns_ino %llu",
610 		       ifindex, ns_dev, ns_inode);
611 }
612 
613 void print_dev_json(__u32 ifindex, __u64 ns_dev, __u64 ns_inode)
614 {
615 	char name[IF_NAMESIZE];
616 
617 	if (!ifindex)
618 		return;
619 
620 	jsonw_name(json_wtr, "dev");
621 	jsonw_start_object(json_wtr);
622 	jsonw_uint_field(json_wtr, "ifindex", ifindex);
623 	jsonw_uint_field(json_wtr, "ns_dev", ns_dev);
624 	jsonw_uint_field(json_wtr, "ns_inode", ns_inode);
625 	if (ifindex_to_name_ns(ifindex, ns_dev, ns_inode, name))
626 		jsonw_string_field(json_wtr, "ifname", name);
627 	jsonw_end_object(json_wtr);
628 }
629 
630 int parse_u32_arg(int *argc, char ***argv, __u32 *val, const char *what)
631 {
632 	char *endptr;
633 
634 	NEXT_ARGP();
635 
636 	if (*val) {
637 		p_err("%s already specified", what);
638 		return -1;
639 	}
640 
641 	*val = strtoul(**argv, &endptr, 0);
642 	if (*endptr) {
643 		p_err("can't parse %s as %s", **argv, what);
644 		return -1;
645 	}
646 	NEXT_ARGP();
647 
648 	return 0;
649 }
650 
651 int __printf(2, 0)
652 print_all_levels(__maybe_unused enum libbpf_print_level level,
653 		 const char *format, va_list args)
654 {
655 	return vfprintf(stderr, format, args);
656 }
657 
658 static int prog_fd_by_nametag(void *nametag, int **fds, bool tag)
659 {
660 	unsigned int id = 0;
661 	int fd, nb_fds = 0;
662 	void *tmp;
663 	int err;
664 
665 	while (true) {
666 		struct bpf_prog_info info = {};
667 		__u32 len = sizeof(info);
668 
669 		err = bpf_prog_get_next_id(id, &id);
670 		if (err) {
671 			if (errno != ENOENT) {
672 				p_err("%s", strerror(errno));
673 				goto err_close_fds;
674 			}
675 			return nb_fds;
676 		}
677 
678 		fd = bpf_prog_get_fd_by_id(id);
679 		if (fd < 0) {
680 			p_err("can't get prog by id (%u): %s",
681 			      id, strerror(errno));
682 			goto err_close_fds;
683 		}
684 
685 		err = bpf_obj_get_info_by_fd(fd, &info, &len);
686 		if (err) {
687 			p_err("can't get prog info (%u): %s",
688 			      id, strerror(errno));
689 			goto err_close_fd;
690 		}
691 
692 		if ((tag && memcmp(nametag, info.tag, BPF_TAG_SIZE)) ||
693 		    (!tag && strncmp(nametag, info.name, BPF_OBJ_NAME_LEN))) {
694 			close(fd);
695 			continue;
696 		}
697 
698 		if (nb_fds > 0) {
699 			tmp = realloc(*fds, (nb_fds + 1) * sizeof(int));
700 			if (!tmp) {
701 				p_err("failed to realloc");
702 				goto err_close_fd;
703 			}
704 			*fds = tmp;
705 		}
706 		(*fds)[nb_fds++] = fd;
707 	}
708 
709 err_close_fd:
710 	close(fd);
711 err_close_fds:
712 	while (--nb_fds >= 0)
713 		close((*fds)[nb_fds]);
714 	return -1;
715 }
716 
717 int prog_parse_fds(int *argc, char ***argv, int **fds)
718 {
719 	if (is_prefix(**argv, "id")) {
720 		unsigned int id;
721 		char *endptr;
722 
723 		NEXT_ARGP();
724 
725 		id = strtoul(**argv, &endptr, 0);
726 		if (*endptr) {
727 			p_err("can't parse %s as ID", **argv);
728 			return -1;
729 		}
730 		NEXT_ARGP();
731 
732 		(*fds)[0] = bpf_prog_get_fd_by_id(id);
733 		if ((*fds)[0] < 0) {
734 			p_err("get by id (%u): %s", id, strerror(errno));
735 			return -1;
736 		}
737 		return 1;
738 	} else if (is_prefix(**argv, "tag")) {
739 		unsigned char tag[BPF_TAG_SIZE];
740 
741 		NEXT_ARGP();
742 
743 		if (sscanf(**argv, BPF_TAG_FMT, tag, tag + 1, tag + 2,
744 			   tag + 3, tag + 4, tag + 5, tag + 6, tag + 7)
745 		    != BPF_TAG_SIZE) {
746 			p_err("can't parse tag");
747 			return -1;
748 		}
749 		NEXT_ARGP();
750 
751 		return prog_fd_by_nametag(tag, fds, true);
752 	} else if (is_prefix(**argv, "name")) {
753 		char *name;
754 
755 		NEXT_ARGP();
756 
757 		name = **argv;
758 		if (strlen(name) > BPF_OBJ_NAME_LEN - 1) {
759 			p_err("can't parse name");
760 			return -1;
761 		}
762 		NEXT_ARGP();
763 
764 		return prog_fd_by_nametag(name, fds, false);
765 	} else if (is_prefix(**argv, "pinned")) {
766 		char *path;
767 
768 		NEXT_ARGP();
769 
770 		path = **argv;
771 		NEXT_ARGP();
772 
773 		(*fds)[0] = open_obj_pinned_any(path, BPF_OBJ_PROG);
774 		if ((*fds)[0] < 0)
775 			return -1;
776 		return 1;
777 	}
778 
779 	p_err("expected 'id', 'tag', 'name' or 'pinned', got: '%s'?", **argv);
780 	return -1;
781 }
782 
783 int prog_parse_fd(int *argc, char ***argv)
784 {
785 	int *fds = NULL;
786 	int nb_fds, fd;
787 
788 	fds = malloc(sizeof(int));
789 	if (!fds) {
790 		p_err("mem alloc failed");
791 		return -1;
792 	}
793 	nb_fds = prog_parse_fds(argc, argv, &fds);
794 	if (nb_fds != 1) {
795 		if (nb_fds > 1) {
796 			p_err("several programs match this handle");
797 			while (nb_fds--)
798 				close(fds[nb_fds]);
799 		}
800 		fd = -1;
801 		goto exit_free;
802 	}
803 
804 	fd = fds[0];
805 exit_free:
806 	free(fds);
807 	return fd;
808 }
809 
810 static int map_fd_by_name(char *name, int **fds)
811 {
812 	unsigned int id = 0;
813 	int fd, nb_fds = 0;
814 	void *tmp;
815 	int err;
816 
817 	while (true) {
818 		struct bpf_map_info info = {};
819 		__u32 len = sizeof(info);
820 
821 		err = bpf_map_get_next_id(id, &id);
822 		if (err) {
823 			if (errno != ENOENT) {
824 				p_err("%s", strerror(errno));
825 				goto err_close_fds;
826 			}
827 			return nb_fds;
828 		}
829 
830 		fd = bpf_map_get_fd_by_id(id);
831 		if (fd < 0) {
832 			p_err("can't get map by id (%u): %s",
833 			      id, strerror(errno));
834 			goto err_close_fds;
835 		}
836 
837 		err = bpf_obj_get_info_by_fd(fd, &info, &len);
838 		if (err) {
839 			p_err("can't get map info (%u): %s",
840 			      id, strerror(errno));
841 			goto err_close_fd;
842 		}
843 
844 		if (strncmp(name, info.name, BPF_OBJ_NAME_LEN)) {
845 			close(fd);
846 			continue;
847 		}
848 
849 		if (nb_fds > 0) {
850 			tmp = realloc(*fds, (nb_fds + 1) * sizeof(int));
851 			if (!tmp) {
852 				p_err("failed to realloc");
853 				goto err_close_fd;
854 			}
855 			*fds = tmp;
856 		}
857 		(*fds)[nb_fds++] = fd;
858 	}
859 
860 err_close_fd:
861 	close(fd);
862 err_close_fds:
863 	while (--nb_fds >= 0)
864 		close((*fds)[nb_fds]);
865 	return -1;
866 }
867 
868 int map_parse_fds(int *argc, char ***argv, int **fds)
869 {
870 	if (is_prefix(**argv, "id")) {
871 		unsigned int id;
872 		char *endptr;
873 
874 		NEXT_ARGP();
875 
876 		id = strtoul(**argv, &endptr, 0);
877 		if (*endptr) {
878 			p_err("can't parse %s as ID", **argv);
879 			return -1;
880 		}
881 		NEXT_ARGP();
882 
883 		(*fds)[0] = bpf_map_get_fd_by_id(id);
884 		if ((*fds)[0] < 0) {
885 			p_err("get map by id (%u): %s", id, strerror(errno));
886 			return -1;
887 		}
888 		return 1;
889 	} else if (is_prefix(**argv, "name")) {
890 		char *name;
891 
892 		NEXT_ARGP();
893 
894 		name = **argv;
895 		if (strlen(name) > BPF_OBJ_NAME_LEN - 1) {
896 			p_err("can't parse name");
897 			return -1;
898 		}
899 		NEXT_ARGP();
900 
901 		return map_fd_by_name(name, fds);
902 	} else if (is_prefix(**argv, "pinned")) {
903 		char *path;
904 
905 		NEXT_ARGP();
906 
907 		path = **argv;
908 		NEXT_ARGP();
909 
910 		(*fds)[0] = open_obj_pinned_any(path, BPF_OBJ_MAP);
911 		if ((*fds)[0] < 0)
912 			return -1;
913 		return 1;
914 	}
915 
916 	p_err("expected 'id', 'name' or 'pinned', got: '%s'?", **argv);
917 	return -1;
918 }
919 
920 int map_parse_fd(int *argc, char ***argv)
921 {
922 	int *fds = NULL;
923 	int nb_fds, fd;
924 
925 	fds = malloc(sizeof(int));
926 	if (!fds) {
927 		p_err("mem alloc failed");
928 		return -1;
929 	}
930 	nb_fds = map_parse_fds(argc, argv, &fds);
931 	if (nb_fds != 1) {
932 		if (nb_fds > 1) {
933 			p_err("several maps match this handle");
934 			while (nb_fds--)
935 				close(fds[nb_fds]);
936 		}
937 		fd = -1;
938 		goto exit_free;
939 	}
940 
941 	fd = fds[0];
942 exit_free:
943 	free(fds);
944 	return fd;
945 }
946 
947 int map_parse_fd_and_info(int *argc, char ***argv, void *info, __u32 *info_len)
948 {
949 	int err;
950 	int fd;
951 
952 	fd = map_parse_fd(argc, argv);
953 	if (fd < 0)
954 		return -1;
955 
956 	err = bpf_obj_get_info_by_fd(fd, info, info_len);
957 	if (err) {
958 		p_err("can't get map info: %s", strerror(errno));
959 		close(fd);
960 		return err;
961 	}
962 
963 	return fd;
964 }
965