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v6.13.7
   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
  40void 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
  58void 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
  71static 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 */
  98static 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
 142void 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
 150static int
 151mnt_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
 182int 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
 196int 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
 218out_free:
 219	free(pname);
 220out_ret:
 221	return fd;
 222}
 223
 224int 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
 247int create_and_mount_bpffs_dir(const char *dir_name)
 248{
 249	char err_str[ERR_MAX_LEN];
 250	bool dir_exists;
 251	int err = 0;
 252
 253	if (is_bpffs(dir_name))
 254		return err;
 255
 256	dir_exists = access(dir_name, F_OK) == 0;
 257
 258	if (!dir_exists) {
 259		char *temp_name;
 260		char *parent_name;
 261
 262		temp_name = strdup(dir_name);
 263		if (!temp_name) {
 264			p_err("mem alloc failed");
 265			return -1;
 266		}
 267
 268		parent_name = dirname(temp_name);
 269
 270		if (is_bpffs(parent_name)) {
 271			/* nothing to do if already mounted */
 272			free(temp_name);
 273			return err;
 274		}
 275
 276		if (access(parent_name, F_OK) == -1) {
 277			p_err("can't create dir '%s' to pin BPF object: parent dir '%s' doesn't exist",
 278			      dir_name, parent_name);
 279			free(temp_name);
 280			return -1;
 281		}
 282
 283		free(temp_name);
 284	}
 285
 286	if (block_mount) {
 287		p_err("no BPF file system found, not mounting it due to --nomount option");
 288		return -1;
 289	}
 290
 291	if (!dir_exists) {
 292		err = mkdir(dir_name, S_IRWXU);
 293		if (err) {
 294			p_err("failed to create dir '%s': %s", dir_name, strerror(errno));
 295			return err;
 296		}
 297	}
 298
 299	err = mnt_fs(dir_name, "bpf", err_str, ERR_MAX_LEN);
 300	if (err) {
 301		err_str[ERR_MAX_LEN - 1] = '\0';
 302		p_err("can't mount BPF file system on given dir '%s': %s",
 303		      dir_name, err_str);
 304
 305		if (!dir_exists)
 306			rmdir(dir_name);
 307	}
 308
 309	return err;
 310}
 311
 312int mount_bpffs_for_file(const char *file_name)
 313{
 314	char err_str[ERR_MAX_LEN];
 315	char *temp_name;
 316	char *dir;
 317	int err = 0;
 318
 319	if (access(file_name, F_OK) != -1) {
 320		p_err("can't pin BPF object: path '%s' already exists", file_name);
 321		return -1;
 322	}
 323
 324	temp_name = strdup(file_name);
 325	if (!temp_name) {
 326		p_err("mem alloc failed");
 327		return -1;
 328	}
 329
 330	dir = dirname(temp_name);
 
 331
 332	if (is_bpffs(dir))
 333		/* nothing to do if already mounted */
 334		goto out_free;
 335
 336	if (access(dir, F_OK) == -1) {
 337		p_err("can't pin BPF object: dir '%s' doesn't exist", dir);
 338		err = -1;
 339		goto out_free;
 340	}
 341
 342	if (block_mount) {
 343		p_err("no BPF file system found, not mounting it due to --nomount option");
 344		err = -1;
 345		goto out_free;
 346	}
 347
 348	err = mnt_fs(dir, "bpf", err_str, ERR_MAX_LEN);
 349	if (err) {
 350		err_str[ERR_MAX_LEN - 1] = '\0';
 351		p_err("can't mount BPF file system to pin the object '%s': %s",
 352		      file_name, err_str);
 353	}
 354
 355out_free:
 356	free(temp_name);
 357	return err;
 358}
 359
 360int do_pin_fd(int fd, const char *name)
 361{
 362	int err;
 363
 364	err = mount_bpffs_for_file(name);
 365	if (err)
 366		return err;
 367
 368	err = bpf_obj_pin(fd, name);
 369	if (err)
 370		p_err("can't pin the object (%s): %s", name, strerror(errno));
 371
 372	return err;
 373}
 374
 375int do_pin_any(int argc, char **argv, int (*get_fd)(int *, char ***))
 376{
 377	int err;
 378	int fd;
 379
 380	if (!REQ_ARGS(3))
 381		return -EINVAL;
 382
 383	fd = get_fd(&argc, &argv);
 384	if (fd < 0)
 385		return fd;
 386
 387	err = do_pin_fd(fd, *argv);
 388
 389	close(fd);
 390	return err;
 391}
 392
 393const char *get_fd_type_name(enum bpf_obj_type type)
 394{
 395	static const char * const names[] = {
 396		[BPF_OBJ_UNKNOWN]	= "unknown",
 397		[BPF_OBJ_PROG]		= "prog",
 398		[BPF_OBJ_MAP]		= "map",
 399		[BPF_OBJ_LINK]		= "link",
 400	};
 401
 402	if (type < 0 || type >= ARRAY_SIZE(names) || !names[type])
 403		return names[BPF_OBJ_UNKNOWN];
 404
 405	return names[type];
 406}
 407
 408void get_prog_full_name(const struct bpf_prog_info *prog_info, int prog_fd,
 409			char *name_buff, size_t buff_len)
 410{
 411	const char *prog_name = prog_info->name;
 412	const struct btf_type *func_type;
 413	struct bpf_func_info finfo = {};
 414	struct bpf_prog_info info = {};
 415	__u32 info_len = sizeof(info);
 416	struct btf *prog_btf = NULL;
 417
 418	if (buff_len <= BPF_OBJ_NAME_LEN ||
 419	    strlen(prog_info->name) < BPF_OBJ_NAME_LEN - 1)
 420		goto copy_name;
 421
 422	if (!prog_info->btf_id || prog_info->nr_func_info == 0)
 423		goto copy_name;
 424
 425	info.nr_func_info = 1;
 426	info.func_info_rec_size = prog_info->func_info_rec_size;
 427	if (info.func_info_rec_size > sizeof(finfo))
 428		info.func_info_rec_size = sizeof(finfo);
 429	info.func_info = ptr_to_u64(&finfo);
 430
 431	if (bpf_prog_get_info_by_fd(prog_fd, &info, &info_len))
 432		goto copy_name;
 433
 434	prog_btf = btf__load_from_kernel_by_id(info.btf_id);
 435	if (!prog_btf)
 436		goto copy_name;
 437
 438	func_type = btf__type_by_id(prog_btf, finfo.type_id);
 439	if (!func_type || !btf_is_func(func_type))
 440		goto copy_name;
 441
 442	prog_name = btf__name_by_offset(prog_btf, func_type->name_off);
 443
 444copy_name:
 445	snprintf(name_buff, buff_len, "%s", prog_name);
 446
 447	if (prog_btf)
 448		btf__free(prog_btf);
 449}
 450
 451int get_fd_type(int fd)
 452{
 453	char path[PATH_MAX];
 454	char buf[512];
 455	ssize_t n;
 456
 457	snprintf(path, sizeof(path), "/proc/self/fd/%d", fd);
 458
 459	n = readlink(path, buf, sizeof(buf));
 460	if (n < 0) {
 461		p_err("can't read link type: %s", strerror(errno));
 462		return -1;
 463	}
 464	if (n == sizeof(path)) {
 465		p_err("can't read link type: path too long!");
 466		return -1;
 467	}
 468
 469	if (strstr(buf, "bpf-map"))
 470		return BPF_OBJ_MAP;
 471	else if (strstr(buf, "bpf-prog"))
 472		return BPF_OBJ_PROG;
 473	else if (strstr(buf, "bpf-link"))
 474		return BPF_OBJ_LINK;
 475
 476	return BPF_OBJ_UNKNOWN;
 477}
 478
 479char *get_fdinfo(int fd, const char *key)
 480{
 481	char path[PATH_MAX];
 482	char *line = NULL;
 483	size_t line_n = 0;
 484	ssize_t n;
 485	FILE *fdi;
 486
 487	snprintf(path, sizeof(path), "/proc/self/fdinfo/%d", fd);
 488
 489	fdi = fopen(path, "r");
 490	if (!fdi)
 491		return NULL;
 492
 493	while ((n = getline(&line, &line_n, fdi)) > 0) {
 494		char *value;
 495		int len;
 496
 497		if (!strstr(line, key))
 498			continue;
 499
 500		fclose(fdi);
 501
 502		value = strchr(line, '\t');
 503		if (!value || !value[1]) {
 504			free(line);
 505			return NULL;
 506		}
 507		value++;
 508
 509		len = strlen(value);
 510		memmove(line, value, len);
 511		line[len - 1] = '\0';
 512
 513		return line;
 514	}
 515
 516	free(line);
 517	fclose(fdi);
 518	return NULL;
 519}
 520
 521void print_data_json(uint8_t *data, size_t len)
 522{
 523	unsigned int i;
 524
 525	jsonw_start_array(json_wtr);
 526	for (i = 0; i < len; i++)
 527		jsonw_printf(json_wtr, "%d", data[i]);
 528	jsonw_end_array(json_wtr);
 529}
 530
 531void print_hex_data_json(uint8_t *data, size_t len)
 532{
 533	unsigned int i;
 534
 535	jsonw_start_array(json_wtr);
 536	for (i = 0; i < len; i++)
 537		jsonw_printf(json_wtr, "\"0x%02hhx\"", data[i]);
 538	jsonw_end_array(json_wtr);
 539}
 540
 541/* extra params for nftw cb */
 542static struct hashmap *build_fn_table;
 543static enum bpf_obj_type build_fn_type;
 544
 545static int do_build_table_cb(const char *fpath, const struct stat *sb,
 546			     int typeflag, struct FTW *ftwbuf)
 547{
 548	struct bpf_prog_info pinned_info;
 549	__u32 len = sizeof(pinned_info);
 550	enum bpf_obj_type objtype;
 551	int fd, err = 0;
 552	char *path;
 553
 554	if (typeflag != FTW_F)
 555		goto out_ret;
 556
 557	fd = open_obj_pinned(fpath, true);
 558	if (fd < 0)
 559		goto out_ret;
 560
 561	objtype = get_fd_type(fd);
 562	if (objtype != build_fn_type)
 563		goto out_close;
 564
 565	memset(&pinned_info, 0, sizeof(pinned_info));
 566	if (bpf_prog_get_info_by_fd(fd, &pinned_info, &len))
 567		goto out_close;
 568
 569	path = strdup(fpath);
 570	if (!path) {
 571		err = -1;
 572		goto out_close;
 573	}
 574
 575	err = hashmap__append(build_fn_table, pinned_info.id, path);
 576	if (err) {
 577		p_err("failed to append entry to hashmap for ID %u, path '%s': %s",
 578		      pinned_info.id, path, strerror(errno));
 579		free(path);
 580		goto out_close;
 581	}
 582
 583out_close:
 584	close(fd);
 585out_ret:
 586	return err;
 587}
 588
 589int build_pinned_obj_table(struct hashmap *tab,
 590			   enum bpf_obj_type type)
 591{
 592	struct mntent *mntent = NULL;
 593	FILE *mntfile = NULL;
 594	int flags = FTW_PHYS;
 595	int nopenfd = 16;
 596	int err = 0;
 597
 598	mntfile = setmntent("/proc/mounts", "r");
 599	if (!mntfile)
 600		return -1;
 601
 602	build_fn_table = tab;
 603	build_fn_type = type;
 604
 605	while ((mntent = getmntent(mntfile))) {
 606		char *path = mntent->mnt_dir;
 607
 608		if (strncmp(mntent->mnt_type, "bpf", 3) != 0)
 609			continue;
 610		err = nftw(path, do_build_table_cb, nopenfd, flags);
 611		if (err)
 612			break;
 613	}
 614	fclose(mntfile);
 615	return err;
 616}
 617
 618void delete_pinned_obj_table(struct hashmap *map)
 619{
 620	struct hashmap_entry *entry;
 621	size_t bkt;
 622
 623	if (!map)
 624		return;
 625
 626	hashmap__for_each_entry(map, entry, bkt)
 627		free(entry->pvalue);
 628
 629	hashmap__free(map);
 630}
 631
 632unsigned int get_page_size(void)
 633{
 634	static int result;
 635
 636	if (!result)
 637		result = getpagesize();
 638	return result;
 639}
 640
 641unsigned int get_possible_cpus(void)
 642{
 643	int cpus = libbpf_num_possible_cpus();
 644
 645	if (cpus < 0) {
 646		p_err("Can't get # of possible cpus: %s", strerror(-cpus));
 647		exit(-1);
 648	}
 649	return cpus;
 650}
 651
 652static char *
 653ifindex_to_name_ns(__u32 ifindex, __u32 ns_dev, __u32 ns_ino, char *buf)
 654{
 655	struct stat st;
 656	int err;
 657
 658	err = stat("/proc/self/ns/net", &st);
 659	if (err) {
 660		p_err("Can't stat /proc/self: %s", strerror(errno));
 661		return NULL;
 662	}
 663
 664	if (st.st_dev != ns_dev || st.st_ino != ns_ino)
 665		return NULL;
 666
 667	return if_indextoname(ifindex, buf);
 668}
 669
 670static int read_sysfs_hex_int(char *path)
 671{
 672	char vendor_id_buf[8];
 673	int len;
 674	int fd;
 675
 676	fd = open(path, O_RDONLY);
 677	if (fd < 0) {
 678		p_err("Can't open %s: %s", path, strerror(errno));
 679		return -1;
 680	}
 681
 682	len = read(fd, vendor_id_buf, sizeof(vendor_id_buf));
 683	close(fd);
 684	if (len < 0) {
 685		p_err("Can't read %s: %s", path, strerror(errno));
 686		return -1;
 687	}
 688	if (len >= (int)sizeof(vendor_id_buf)) {
 689		p_err("Value in %s too long", path);
 690		return -1;
 691	}
 692
 693	vendor_id_buf[len] = 0;
 694
 695	return strtol(vendor_id_buf, NULL, 0);
 696}
 697
 698static int read_sysfs_netdev_hex_int(char *devname, const char *entry_name)
 699{
 700	char full_path[64];
 701
 702	snprintf(full_path, sizeof(full_path), "/sys/class/net/%s/device/%s",
 703		 devname, entry_name);
 704
 705	return read_sysfs_hex_int(full_path);
 706}
 707
 708const char *
 709ifindex_to_arch(__u32 ifindex, __u64 ns_dev, __u64 ns_ino, const char **opt)
 710{
 711	__maybe_unused int device_id;
 712	char devname[IF_NAMESIZE];
 713	int vendor_id;
 714
 715	if (!ifindex_to_name_ns(ifindex, ns_dev, ns_ino, devname)) {
 716		p_err("Can't get net device name for ifindex %d: %s", ifindex,
 717		      strerror(errno));
 718		return NULL;
 719	}
 720
 721	vendor_id = read_sysfs_netdev_hex_int(devname, "vendor");
 722	if (vendor_id < 0) {
 723		p_err("Can't get device vendor id for %s", devname);
 724		return NULL;
 725	}
 726
 727	switch (vendor_id) {
 728#ifdef HAVE_LIBBFD_SUPPORT
 729	case 0x19ee:
 730		device_id = read_sysfs_netdev_hex_int(devname, "device");
 731		if (device_id != 0x4000 &&
 732		    device_id != 0x6000 &&
 733		    device_id != 0x6003)
 734			p_info("Unknown NFP device ID, assuming it is NFP-6xxx arch");
 735		*opt = "ctx4";
 736		return "NFP-6xxx";
 737#endif /* HAVE_LIBBFD_SUPPORT */
 738	/* No NFP support in LLVM, we have no valid triple to return. */
 739	default:
 740		p_err("Can't get arch name for device vendor id 0x%04x",
 741		      vendor_id);
 742		return NULL;
 743	}
 744}
 745
 746void print_dev_plain(__u32 ifindex, __u64 ns_dev, __u64 ns_inode)
 747{
 748	char name[IF_NAMESIZE];
 749
 750	if (!ifindex)
 751		return;
 752
 753	printf("  offloaded_to ");
 754	if (ifindex_to_name_ns(ifindex, ns_dev, ns_inode, name))
 755		printf("%s", name);
 756	else
 757		printf("ifindex %u ns_dev %llu ns_ino %llu",
 758		       ifindex, ns_dev, ns_inode);
 759}
 760
 761void print_dev_json(__u32 ifindex, __u64 ns_dev, __u64 ns_inode)
 762{
 763	char name[IF_NAMESIZE];
 764
 765	if (!ifindex)
 766		return;
 767
 768	jsonw_name(json_wtr, "dev");
 769	jsonw_start_object(json_wtr);
 770	jsonw_uint_field(json_wtr, "ifindex", ifindex);
 771	jsonw_uint_field(json_wtr, "ns_dev", ns_dev);
 772	jsonw_uint_field(json_wtr, "ns_inode", ns_inode);
 773	if (ifindex_to_name_ns(ifindex, ns_dev, ns_inode, name))
 774		jsonw_string_field(json_wtr, "ifname", name);
 775	jsonw_end_object(json_wtr);
 776}
 777
 778int parse_u32_arg(int *argc, char ***argv, __u32 *val, const char *what)
 779{
 780	char *endptr;
 781
 782	NEXT_ARGP();
 783
 784	if (*val) {
 785		p_err("%s already specified", what);
 786		return -1;
 787	}
 788
 789	*val = strtoul(**argv, &endptr, 0);
 790	if (*endptr) {
 791		p_err("can't parse %s as %s", **argv, what);
 792		return -1;
 793	}
 794	NEXT_ARGP();
 795
 796	return 0;
 797}
 798
 799int __printf(2, 0)
 800print_all_levels(__maybe_unused enum libbpf_print_level level,
 801		 const char *format, va_list args)
 802{
 803	return vfprintf(stderr, format, args);
 804}
 805
 806static int prog_fd_by_nametag(void *nametag, int **fds, bool tag)
 807{
 808	char prog_name[MAX_PROG_FULL_NAME];
 809	unsigned int id = 0;
 810	int fd, nb_fds = 0;
 811	void *tmp;
 812	int err;
 813
 814	while (true) {
 815		struct bpf_prog_info info = {};
 816		__u32 len = sizeof(info);
 817
 818		err = bpf_prog_get_next_id(id, &id);
 819		if (err) {
 820			if (errno != ENOENT) {
 821				p_err("%s", strerror(errno));
 822				goto err_close_fds;
 823			}
 824			return nb_fds;
 825		}
 826
 827		fd = bpf_prog_get_fd_by_id(id);
 828		if (fd < 0) {
 829			p_err("can't get prog by id (%u): %s",
 830			      id, strerror(errno));
 831			goto err_close_fds;
 832		}
 833
 834		err = bpf_prog_get_info_by_fd(fd, &info, &len);
 835		if (err) {
 836			p_err("can't get prog info (%u): %s",
 837			      id, strerror(errno));
 838			goto err_close_fd;
 839		}
 840
 841		if (tag && memcmp(nametag, info.tag, BPF_TAG_SIZE)) {
 842			close(fd);
 843			continue;
 844		}
 845
 846		if (!tag) {
 847			get_prog_full_name(&info, fd, prog_name,
 848					   sizeof(prog_name));
 849			if (strncmp(nametag, prog_name, sizeof(prog_name))) {
 850				close(fd);
 851				continue;
 852			}
 853		}
 854
 855		if (nb_fds > 0) {
 856			tmp = realloc(*fds, (nb_fds + 1) * sizeof(int));
 857			if (!tmp) {
 858				p_err("failed to realloc");
 859				goto err_close_fd;
 860			}
 861			*fds = tmp;
 862		}
 863		(*fds)[nb_fds++] = fd;
 864	}
 865
 866err_close_fd:
 867	close(fd);
 868err_close_fds:
 869	while (--nb_fds >= 0)
 870		close((*fds)[nb_fds]);
 871	return -1;
 872}
 873
 874int prog_parse_fds(int *argc, char ***argv, int **fds)
 875{
 876	if (is_prefix(**argv, "id")) {
 877		unsigned int id;
 878		char *endptr;
 879
 880		NEXT_ARGP();
 881
 882		id = strtoul(**argv, &endptr, 0);
 883		if (*endptr) {
 884			p_err("can't parse %s as ID", **argv);
 885			return -1;
 886		}
 887		NEXT_ARGP();
 888
 889		(*fds)[0] = bpf_prog_get_fd_by_id(id);
 890		if ((*fds)[0] < 0) {
 891			p_err("get by id (%u): %s", id, strerror(errno));
 892			return -1;
 893		}
 894		return 1;
 895	} else if (is_prefix(**argv, "tag")) {
 896		unsigned char tag[BPF_TAG_SIZE];
 897
 898		NEXT_ARGP();
 899
 900		if (sscanf(**argv, BPF_TAG_FMT, tag, tag + 1, tag + 2,
 901			   tag + 3, tag + 4, tag + 5, tag + 6, tag + 7)
 902		    != BPF_TAG_SIZE) {
 903			p_err("can't parse tag");
 904			return -1;
 905		}
 906		NEXT_ARGP();
 907
 908		return prog_fd_by_nametag(tag, fds, true);
 909	} else if (is_prefix(**argv, "name")) {
 910		char *name;
 911
 912		NEXT_ARGP();
 913
 914		name = **argv;
 915		if (strlen(name) > MAX_PROG_FULL_NAME - 1) {
 916			p_err("can't parse name");
 917			return -1;
 918		}
 919		NEXT_ARGP();
 920
 921		return prog_fd_by_nametag(name, fds, false);
 922	} else if (is_prefix(**argv, "pinned")) {
 923		char *path;
 924
 925		NEXT_ARGP();
 926
 927		path = **argv;
 928		NEXT_ARGP();
 929
 930		(*fds)[0] = open_obj_pinned_any(path, BPF_OBJ_PROG);
 931		if ((*fds)[0] < 0)
 932			return -1;
 933		return 1;
 934	}
 935
 936	p_err("expected 'id', 'tag', 'name' or 'pinned', got: '%s'?", **argv);
 937	return -1;
 938}
 939
 940int prog_parse_fd(int *argc, char ***argv)
 941{
 942	int *fds = NULL;
 943	int nb_fds, fd;
 944
 945	fds = malloc(sizeof(int));
 946	if (!fds) {
 947		p_err("mem alloc failed");
 948		return -1;
 949	}
 950	nb_fds = prog_parse_fds(argc, argv, &fds);
 951	if (nb_fds != 1) {
 952		if (nb_fds > 1) {
 953			p_err("several programs match this handle");
 954			while (nb_fds--)
 955				close(fds[nb_fds]);
 956		}
 957		fd = -1;
 958		goto exit_free;
 959	}
 960
 961	fd = fds[0];
 962exit_free:
 963	free(fds);
 964	return fd;
 965}
 966
 967static int map_fd_by_name(char *name, int **fds)
 968{
 969	unsigned int id = 0;
 970	int fd, nb_fds = 0;
 971	void *tmp;
 972	int err;
 973
 974	while (true) {
 975		struct bpf_map_info info = {};
 976		__u32 len = sizeof(info);
 977
 978		err = bpf_map_get_next_id(id, &id);
 979		if (err) {
 980			if (errno != ENOENT) {
 981				p_err("%s", strerror(errno));
 982				goto err_close_fds;
 983			}
 984			return nb_fds;
 985		}
 986
 987		fd = bpf_map_get_fd_by_id(id);
 988		if (fd < 0) {
 989			p_err("can't get map by id (%u): %s",
 990			      id, strerror(errno));
 991			goto err_close_fds;
 992		}
 993
 994		err = bpf_map_get_info_by_fd(fd, &info, &len);
 995		if (err) {
 996			p_err("can't get map info (%u): %s",
 997			      id, strerror(errno));
 998			goto err_close_fd;
 999		}
1000
1001		if (strncmp(name, info.name, BPF_OBJ_NAME_LEN)) {
1002			close(fd);
1003			continue;
1004		}
1005
1006		if (nb_fds > 0) {
1007			tmp = realloc(*fds, (nb_fds + 1) * sizeof(int));
1008			if (!tmp) {
1009				p_err("failed to realloc");
1010				goto err_close_fd;
1011			}
1012			*fds = tmp;
1013		}
1014		(*fds)[nb_fds++] = fd;
1015	}
1016
1017err_close_fd:
1018	close(fd);
1019err_close_fds:
1020	while (--nb_fds >= 0)
1021		close((*fds)[nb_fds]);
1022	return -1;
1023}
1024
1025int map_parse_fds(int *argc, char ***argv, int **fds)
1026{
1027	if (is_prefix(**argv, "id")) {
1028		unsigned int id;
1029		char *endptr;
1030
1031		NEXT_ARGP();
1032
1033		id = strtoul(**argv, &endptr, 0);
1034		if (*endptr) {
1035			p_err("can't parse %s as ID", **argv);
1036			return -1;
1037		}
1038		NEXT_ARGP();
1039
1040		(*fds)[0] = bpf_map_get_fd_by_id(id);
1041		if ((*fds)[0] < 0) {
1042			p_err("get map by id (%u): %s", id, strerror(errno));
1043			return -1;
1044		}
1045		return 1;
1046	} else if (is_prefix(**argv, "name")) {
1047		char *name;
1048
1049		NEXT_ARGP();
1050
1051		name = **argv;
1052		if (strlen(name) > BPF_OBJ_NAME_LEN - 1) {
1053			p_err("can't parse name");
1054			return -1;
1055		}
1056		NEXT_ARGP();
1057
1058		return map_fd_by_name(name, fds);
1059	} else if (is_prefix(**argv, "pinned")) {
1060		char *path;
1061
1062		NEXT_ARGP();
1063
1064		path = **argv;
1065		NEXT_ARGP();
1066
1067		(*fds)[0] = open_obj_pinned_any(path, BPF_OBJ_MAP);
1068		if ((*fds)[0] < 0)
1069			return -1;
1070		return 1;
1071	}
1072
1073	p_err("expected 'id', 'name' or 'pinned', got: '%s'?", **argv);
1074	return -1;
1075}
1076
1077int map_parse_fd(int *argc, char ***argv)
1078{
1079	int *fds = NULL;
1080	int nb_fds, fd;
1081
1082	fds = malloc(sizeof(int));
1083	if (!fds) {
1084		p_err("mem alloc failed");
1085		return -1;
1086	}
1087	nb_fds = map_parse_fds(argc, argv, &fds);
1088	if (nb_fds != 1) {
1089		if (nb_fds > 1) {
1090			p_err("several maps match this handle");
1091			while (nb_fds--)
1092				close(fds[nb_fds]);
1093		}
1094		fd = -1;
1095		goto exit_free;
1096	}
1097
1098	fd = fds[0];
1099exit_free:
1100	free(fds);
1101	return fd;
1102}
1103
1104int map_parse_fd_and_info(int *argc, char ***argv, struct bpf_map_info *info,
1105			  __u32 *info_len)
1106{
1107	int err;
1108	int fd;
1109
1110	fd = map_parse_fd(argc, argv);
1111	if (fd < 0)
1112		return -1;
1113
1114	err = bpf_map_get_info_by_fd(fd, info, info_len);
1115	if (err) {
1116		p_err("can't get map info: %s", strerror(errno));
1117		close(fd);
1118		return err;
1119	}
1120
1121	return fd;
1122}
1123
1124size_t hash_fn_for_key_as_id(long key, void *ctx)
1125{
1126	return key;
1127}
1128
1129bool equal_fn_for_key_as_id(long k1, long k2, void *ctx)
1130{
1131	return k1 == k2;
1132}
1133
1134const char *bpf_attach_type_input_str(enum bpf_attach_type t)
1135{
1136	switch (t) {
1137	case BPF_CGROUP_INET_INGRESS:		return "ingress";
1138	case BPF_CGROUP_INET_EGRESS:		return "egress";
1139	case BPF_CGROUP_INET_SOCK_CREATE:	return "sock_create";
1140	case BPF_CGROUP_INET_SOCK_RELEASE:	return "sock_release";
1141	case BPF_CGROUP_SOCK_OPS:		return "sock_ops";
1142	case BPF_CGROUP_DEVICE:			return "device";
1143	case BPF_CGROUP_INET4_BIND:		return "bind4";
1144	case BPF_CGROUP_INET6_BIND:		return "bind6";
1145	case BPF_CGROUP_INET4_CONNECT:		return "connect4";
1146	case BPF_CGROUP_INET6_CONNECT:		return "connect6";
1147	case BPF_CGROUP_INET4_POST_BIND:	return "post_bind4";
1148	case BPF_CGROUP_INET6_POST_BIND:	return "post_bind6";
1149	case BPF_CGROUP_INET4_GETPEERNAME:	return "getpeername4";
1150	case BPF_CGROUP_INET6_GETPEERNAME:	return "getpeername6";
1151	case BPF_CGROUP_INET4_GETSOCKNAME:	return "getsockname4";
1152	case BPF_CGROUP_INET6_GETSOCKNAME:	return "getsockname6";
1153	case BPF_CGROUP_UDP4_SENDMSG:		return "sendmsg4";
1154	case BPF_CGROUP_UDP6_SENDMSG:		return "sendmsg6";
1155	case BPF_CGROUP_SYSCTL:			return "sysctl";
1156	case BPF_CGROUP_UDP4_RECVMSG:		return "recvmsg4";
1157	case BPF_CGROUP_UDP6_RECVMSG:		return "recvmsg6";
1158	case BPF_CGROUP_GETSOCKOPT:		return "getsockopt";
1159	case BPF_CGROUP_SETSOCKOPT:		return "setsockopt";
1160	case BPF_TRACE_RAW_TP:			return "raw_tp";
1161	case BPF_TRACE_FENTRY:			return "fentry";
1162	case BPF_TRACE_FEXIT:			return "fexit";
1163	case BPF_MODIFY_RETURN:			return "mod_ret";
1164	case BPF_SK_REUSEPORT_SELECT:		return "sk_skb_reuseport_select";
1165	case BPF_SK_REUSEPORT_SELECT_OR_MIGRATE:	return "sk_skb_reuseport_select_or_migrate";
1166	default:	return libbpf_bpf_attach_type_str(t);
1167	}
1168}
1169
1170int pathname_concat(char *buf, int buf_sz, const char *path,
1171		    const char *name)
1172{
1173	int len;
1174
1175	len = snprintf(buf, buf_sz, "%s/%s", path, name);
1176	if (len < 0)
1177		return -EINVAL;
1178	if (len >= buf_sz)
1179		return -ENAMETOOLONG;
1180
1181	return 0;
1182}
v6.8
   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
  40void 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
  58void 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
  71static 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 */
  98static 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
 142void 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
 150static int
 151mnt_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
 182int 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
 196int 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
 218out_free:
 219	free(pname);
 220out_ret:
 221	return fd;
 222}
 223
 224int 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
 247int 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
 283out_free:
 284	free(file);
 285	return err;
 286}
 287
 288int 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
 303int 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
 321const 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
 336void 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
 372copy_name:
 373	snprintf(name_buff, buff_len, "%s", prog_name);
 374
 375	if (prog_btf)
 376		btf__free(prog_btf);
 377}
 378
 379int 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
 407char *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
 449void 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
 459void 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 */
 470static struct hashmap *build_fn_table;
 471static enum bpf_obj_type build_fn_type;
 472
 473static 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
 511out_close:
 512	close(fd);
 513out_ret:
 514	return err;
 515}
 516
 517int 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
 546void 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
 560unsigned int get_page_size(void)
 561{
 562	static int result;
 563
 564	if (!result)
 565		result = getpagesize();
 566	return result;
 567}
 568
 569unsigned 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
 580static char *
 581ifindex_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
 598static 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
 626static 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
 636const char *
 637ifindex_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
 674void 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
 689void 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
 706int 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
 727int __printf(2, 0)
 728print_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
 734static 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
 794err_close_fd:
 795	close(fd);
 796err_close_fds:
 797	while (--nb_fds >= 0)
 798		close((*fds)[nb_fds]);
 799	return -1;
 800}
 801
 802int 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
 868int 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];
 890exit_free:
 891	free(fds);
 892	return fd;
 893}
 894
 895static 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
 945err_close_fd:
 946	close(fd);
 947err_close_fds:
 948	while (--nb_fds >= 0)
 949		close((*fds)[nb_fds]);
 950	return -1;
 951}
 952
 953int 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
1005int 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];
1027exit_free:
1028	free(fds);
1029	return fd;
1030}
1031
1032int 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
1052size_t hash_fn_for_key_as_id(long key, void *ctx)
1053{
1054	return key;
1055}
1056
1057bool equal_fn_for_key_as_id(long k1, long k2, void *ctx)
1058{
1059	return k1 == k2;
1060}
1061
1062const 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
1098int 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}