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 strcpy(file, name); 232 dir = dirname(file); 233 234 if (is_bpffs(dir)) 235 /* nothing to do if already mounted */ 236 goto out_free; 237 238 if (block_mount) { 239 p_err("no BPF file system found, not mounting it due to --nomount option"); 240 err = -1; 241 goto out_free; 242 } 243 244 err = mnt_fs(dir, "bpf", err_str, ERR_MAX_LEN); 245 if (err) { 246 err_str[ERR_MAX_LEN - 1] = '\0'; 247 p_err("can't mount BPF file system to pin the object (%s): %s", 248 name, err_str); 249 } 250 251 out_free: 252 free(file); 253 return err; 254 } 255 256 int do_pin_fd(int fd, const char *name) 257 { 258 int err; 259 260 err = mount_bpffs_for_pin(name); 261 if (err) 262 return err; 263 264 err = bpf_obj_pin(fd, name); 265 if (err) 266 p_err("can't pin the object (%s): %s", name, strerror(errno)); 267 268 return err; 269 } 270 271 int do_pin_any(int argc, char **argv, int (*get_fd)(int *, char ***)) 272 { 273 int err; 274 int fd; 275 276 fd = get_fd(&argc, &argv); 277 if (fd < 0) 278 return fd; 279 280 err = do_pin_fd(fd, *argv); 281 282 close(fd); 283 return err; 284 } 285 286 const char *get_fd_type_name(enum bpf_obj_type type) 287 { 288 static const char * const names[] = { 289 [BPF_OBJ_UNKNOWN] = "unknown", 290 [BPF_OBJ_PROG] = "prog", 291 [BPF_OBJ_MAP] = "map", 292 }; 293 294 if (type < 0 || type >= ARRAY_SIZE(names) || !names[type]) 295 return names[BPF_OBJ_UNKNOWN]; 296 297 return names[type]; 298 } 299 300 int get_fd_type(int fd) 301 { 302 char path[PATH_MAX]; 303 char buf[512]; 304 ssize_t n; 305 306 snprintf(path, sizeof(path), "/proc/self/fd/%d", fd); 307 308 n = readlink(path, buf, sizeof(buf)); 309 if (n < 0) { 310 p_err("can't read link type: %s", strerror(errno)); 311 return -1; 312 } 313 if (n == sizeof(path)) { 314 p_err("can't read link type: path too long!"); 315 return -1; 316 } 317 318 if (strstr(buf, "bpf-map")) 319 return BPF_OBJ_MAP; 320 else if (strstr(buf, "bpf-prog")) 321 return BPF_OBJ_PROG; 322 else if (strstr(buf, "bpf-link")) 323 return BPF_OBJ_LINK; 324 325 return BPF_OBJ_UNKNOWN; 326 } 327 328 char *get_fdinfo(int fd, const char *key) 329 { 330 char path[PATH_MAX]; 331 char *line = NULL; 332 size_t line_n = 0; 333 ssize_t n; 334 FILE *fdi; 335 336 snprintf(path, sizeof(path), "/proc/self/fdinfo/%d", fd); 337 338 fdi = fopen(path, "r"); 339 if (!fdi) 340 return NULL; 341 342 while ((n = getline(&line, &line_n, fdi)) > 0) { 343 char *value; 344 int len; 345 346 if (!strstr(line, key)) 347 continue; 348 349 fclose(fdi); 350 351 value = strchr(line, '\t'); 352 if (!value || !value[1]) { 353 free(line); 354 return NULL; 355 } 356 value++; 357 358 len = strlen(value); 359 memmove(line, value, len); 360 line[len - 1] = '\0'; 361 362 return line; 363 } 364 365 free(line); 366 fclose(fdi); 367 return NULL; 368 } 369 370 void print_data_json(uint8_t *data, size_t len) 371 { 372 unsigned int i; 373 374 jsonw_start_array(json_wtr); 375 for (i = 0; i < len; i++) 376 jsonw_printf(json_wtr, "%d", data[i]); 377 jsonw_end_array(json_wtr); 378 } 379 380 void print_hex_data_json(uint8_t *data, size_t len) 381 { 382 unsigned int i; 383 384 jsonw_start_array(json_wtr); 385 for (i = 0; i < len; i++) 386 jsonw_printf(json_wtr, "\"0x%02hhx\"", data[i]); 387 jsonw_end_array(json_wtr); 388 } 389 390 /* extra params for nftw cb */ 391 static struct pinned_obj_table *build_fn_table; 392 static enum bpf_obj_type build_fn_type; 393 394 static int do_build_table_cb(const char *fpath, const struct stat *sb, 395 int typeflag, struct FTW *ftwbuf) 396 { 397 struct bpf_prog_info pinned_info; 398 __u32 len = sizeof(pinned_info); 399 struct pinned_obj *obj_node; 400 enum bpf_obj_type objtype; 401 int fd, err = 0; 402 403 if (typeflag != FTW_F) 404 goto out_ret; 405 406 fd = open_obj_pinned(fpath, true); 407 if (fd < 0) 408 goto out_ret; 409 410 objtype = get_fd_type(fd); 411 if (objtype != build_fn_type) 412 goto out_close; 413 414 memset(&pinned_info, 0, sizeof(pinned_info)); 415 if (bpf_obj_get_info_by_fd(fd, &pinned_info, &len)) 416 goto out_close; 417 418 obj_node = calloc(1, sizeof(*obj_node)); 419 if (!obj_node) { 420 err = -1; 421 goto out_close; 422 } 423 424 obj_node->id = pinned_info.id; 425 obj_node->path = strdup(fpath); 426 if (!obj_node->path) { 427 err = -1; 428 free(obj_node); 429 goto out_close; 430 } 431 432 hash_add(build_fn_table->table, &obj_node->hash, obj_node->id); 433 out_close: 434 close(fd); 435 out_ret: 436 return err; 437 } 438 439 int build_pinned_obj_table(struct pinned_obj_table *tab, 440 enum bpf_obj_type type) 441 { 442 struct mntent *mntent = NULL; 443 FILE *mntfile = NULL; 444 int flags = FTW_PHYS; 445 int nopenfd = 16; 446 int err = 0; 447 448 mntfile = setmntent("/proc/mounts", "r"); 449 if (!mntfile) 450 return -1; 451 452 build_fn_table = tab; 453 build_fn_type = type; 454 455 while ((mntent = getmntent(mntfile))) { 456 char *path = mntent->mnt_dir; 457 458 if (strncmp(mntent->mnt_type, "bpf", 3) != 0) 459 continue; 460 err = nftw(path, do_build_table_cb, nopenfd, flags); 461 if (err) 462 break; 463 } 464 fclose(mntfile); 465 return err; 466 } 467 468 void delete_pinned_obj_table(struct pinned_obj_table *tab) 469 { 470 struct pinned_obj *obj; 471 struct hlist_node *tmp; 472 unsigned int bkt; 473 474 hash_for_each_safe(tab->table, bkt, tmp, obj, hash) { 475 hash_del(&obj->hash); 476 free(obj->path); 477 free(obj); 478 } 479 } 480 481 unsigned int get_page_size(void) 482 { 483 static int result; 484 485 if (!result) 486 result = getpagesize(); 487 return result; 488 } 489 490 unsigned int get_possible_cpus(void) 491 { 492 int cpus = libbpf_num_possible_cpus(); 493 494 if (cpus < 0) { 495 p_err("Can't get # of possible cpus: %s", strerror(-cpus)); 496 exit(-1); 497 } 498 return cpus; 499 } 500 501 static char * 502 ifindex_to_name_ns(__u32 ifindex, __u32 ns_dev, __u32 ns_ino, char *buf) 503 { 504 struct stat st; 505 int err; 506 507 err = stat("/proc/self/ns/net", &st); 508 if (err) { 509 p_err("Can't stat /proc/self: %s", strerror(errno)); 510 return NULL; 511 } 512 513 if (st.st_dev != ns_dev || st.st_ino != ns_ino) 514 return NULL; 515 516 return if_indextoname(ifindex, buf); 517 } 518 519 static int read_sysfs_hex_int(char *path) 520 { 521 char vendor_id_buf[8]; 522 int len; 523 int fd; 524 525 fd = open(path, O_RDONLY); 526 if (fd < 0) { 527 p_err("Can't open %s: %s", path, strerror(errno)); 528 return -1; 529 } 530 531 len = read(fd, vendor_id_buf, sizeof(vendor_id_buf)); 532 close(fd); 533 if (len < 0) { 534 p_err("Can't read %s: %s", path, strerror(errno)); 535 return -1; 536 } 537 if (len >= (int)sizeof(vendor_id_buf)) { 538 p_err("Value in %s too long", path); 539 return -1; 540 } 541 542 vendor_id_buf[len] = 0; 543 544 return strtol(vendor_id_buf, NULL, 0); 545 } 546 547 static int read_sysfs_netdev_hex_int(char *devname, const char *entry_name) 548 { 549 char full_path[64]; 550 551 snprintf(full_path, sizeof(full_path), "/sys/class/net/%s/device/%s", 552 devname, entry_name); 553 554 return read_sysfs_hex_int(full_path); 555 } 556 557 const char * 558 ifindex_to_bfd_params(__u32 ifindex, __u64 ns_dev, __u64 ns_ino, 559 const char **opt) 560 { 561 char devname[IF_NAMESIZE]; 562 int vendor_id; 563 int device_id; 564 565 if (!ifindex_to_name_ns(ifindex, ns_dev, ns_ino, devname)) { 566 p_err("Can't get net device name for ifindex %d: %s", ifindex, 567 strerror(errno)); 568 return NULL; 569 } 570 571 vendor_id = read_sysfs_netdev_hex_int(devname, "vendor"); 572 if (vendor_id < 0) { 573 p_err("Can't get device vendor id for %s", devname); 574 return NULL; 575 } 576 577 switch (vendor_id) { 578 case 0x19ee: 579 device_id = read_sysfs_netdev_hex_int(devname, "device"); 580 if (device_id != 0x4000 && 581 device_id != 0x6000 && 582 device_id != 0x6003) 583 p_info("Unknown NFP device ID, assuming it is NFP-6xxx arch"); 584 *opt = "ctx4"; 585 return "NFP-6xxx"; 586 default: 587 p_err("Can't get bfd arch name for device vendor id 0x%04x", 588 vendor_id); 589 return NULL; 590 } 591 } 592 593 void print_dev_plain(__u32 ifindex, __u64 ns_dev, __u64 ns_inode) 594 { 595 char name[IF_NAMESIZE]; 596 597 if (!ifindex) 598 return; 599 600 printf(" offloaded_to "); 601 if (ifindex_to_name_ns(ifindex, ns_dev, ns_inode, name)) 602 printf("%s", name); 603 else 604 printf("ifindex %u ns_dev %llu ns_ino %llu", 605 ifindex, ns_dev, ns_inode); 606 } 607 608 void print_dev_json(__u32 ifindex, __u64 ns_dev, __u64 ns_inode) 609 { 610 char name[IF_NAMESIZE]; 611 612 if (!ifindex) 613 return; 614 615 jsonw_name(json_wtr, "dev"); 616 jsonw_start_object(json_wtr); 617 jsonw_uint_field(json_wtr, "ifindex", ifindex); 618 jsonw_uint_field(json_wtr, "ns_dev", ns_dev); 619 jsonw_uint_field(json_wtr, "ns_inode", ns_inode); 620 if (ifindex_to_name_ns(ifindex, ns_dev, ns_inode, name)) 621 jsonw_string_field(json_wtr, "ifname", name); 622 jsonw_end_object(json_wtr); 623 } 624 625 int parse_u32_arg(int *argc, char ***argv, __u32 *val, const char *what) 626 { 627 char *endptr; 628 629 NEXT_ARGP(); 630 631 if (*val) { 632 p_err("%s already specified", what); 633 return -1; 634 } 635 636 *val = strtoul(**argv, &endptr, 0); 637 if (*endptr) { 638 p_err("can't parse %s as %s", **argv, what); 639 return -1; 640 } 641 NEXT_ARGP(); 642 643 return 0; 644 } 645 646 int __printf(2, 0) 647 print_all_levels(__maybe_unused enum libbpf_print_level level, 648 const char *format, va_list args) 649 { 650 return vfprintf(stderr, format, args); 651 } 652 653 static int prog_fd_by_nametag(void *nametag, int **fds, bool tag) 654 { 655 unsigned int id = 0; 656 int fd, nb_fds = 0; 657 void *tmp; 658 int err; 659 660 while (true) { 661 struct bpf_prog_info info = {}; 662 __u32 len = sizeof(info); 663 664 err = bpf_prog_get_next_id(id, &id); 665 if (err) { 666 if (errno != ENOENT) { 667 p_err("%s", strerror(errno)); 668 goto err_close_fds; 669 } 670 return nb_fds; 671 } 672 673 fd = bpf_prog_get_fd_by_id(id); 674 if (fd < 0) { 675 p_err("can't get prog by id (%u): %s", 676 id, strerror(errno)); 677 goto err_close_fds; 678 } 679 680 err = bpf_obj_get_info_by_fd(fd, &info, &len); 681 if (err) { 682 p_err("can't get prog info (%u): %s", 683 id, strerror(errno)); 684 goto err_close_fd; 685 } 686 687 if ((tag && memcmp(nametag, info.tag, BPF_TAG_SIZE)) || 688 (!tag && strncmp(nametag, info.name, BPF_OBJ_NAME_LEN))) { 689 close(fd); 690 continue; 691 } 692 693 if (nb_fds > 0) { 694 tmp = realloc(*fds, (nb_fds + 1) * sizeof(int)); 695 if (!tmp) { 696 p_err("failed to realloc"); 697 goto err_close_fd; 698 } 699 *fds = tmp; 700 } 701 (*fds)[nb_fds++] = fd; 702 } 703 704 err_close_fd: 705 close(fd); 706 err_close_fds: 707 while (--nb_fds >= 0) 708 close((*fds)[nb_fds]); 709 return -1; 710 } 711 712 int prog_parse_fds(int *argc, char ***argv, int **fds) 713 { 714 if (is_prefix(**argv, "id")) { 715 unsigned int id; 716 char *endptr; 717 718 NEXT_ARGP(); 719 720 id = strtoul(**argv, &endptr, 0); 721 if (*endptr) { 722 p_err("can't parse %s as ID", **argv); 723 return -1; 724 } 725 NEXT_ARGP(); 726 727 (*fds)[0] = bpf_prog_get_fd_by_id(id); 728 if ((*fds)[0] < 0) { 729 p_err("get by id (%u): %s", id, strerror(errno)); 730 return -1; 731 } 732 return 1; 733 } else if (is_prefix(**argv, "tag")) { 734 unsigned char tag[BPF_TAG_SIZE]; 735 736 NEXT_ARGP(); 737 738 if (sscanf(**argv, BPF_TAG_FMT, tag, tag + 1, tag + 2, 739 tag + 3, tag + 4, tag + 5, tag + 6, tag + 7) 740 != BPF_TAG_SIZE) { 741 p_err("can't parse tag"); 742 return -1; 743 } 744 NEXT_ARGP(); 745 746 return prog_fd_by_nametag(tag, fds, true); 747 } else if (is_prefix(**argv, "name")) { 748 char *name; 749 750 NEXT_ARGP(); 751 752 name = **argv; 753 if (strlen(name) > BPF_OBJ_NAME_LEN - 1) { 754 p_err("can't parse name"); 755 return -1; 756 } 757 NEXT_ARGP(); 758 759 return prog_fd_by_nametag(name, fds, false); 760 } else if (is_prefix(**argv, "pinned")) { 761 char *path; 762 763 NEXT_ARGP(); 764 765 path = **argv; 766 NEXT_ARGP(); 767 768 (*fds)[0] = open_obj_pinned_any(path, BPF_OBJ_PROG); 769 if ((*fds)[0] < 0) 770 return -1; 771 return 1; 772 } 773 774 p_err("expected 'id', 'tag', 'name' or 'pinned', got: '%s'?", **argv); 775 return -1; 776 } 777 778 int prog_parse_fd(int *argc, char ***argv) 779 { 780 int *fds = NULL; 781 int nb_fds, fd; 782 783 fds = malloc(sizeof(int)); 784 if (!fds) { 785 p_err("mem alloc failed"); 786 return -1; 787 } 788 nb_fds = prog_parse_fds(argc, argv, &fds); 789 if (nb_fds != 1) { 790 if (nb_fds > 1) { 791 p_err("several programs match this handle"); 792 while (nb_fds--) 793 close(fds[nb_fds]); 794 } 795 fd = -1; 796 goto exit_free; 797 } 798 799 fd = fds[0]; 800 exit_free: 801 free(fds); 802 return fd; 803 } 804 805 static int map_fd_by_name(char *name, int **fds) 806 { 807 unsigned int id = 0; 808 int fd, nb_fds = 0; 809 void *tmp; 810 int err; 811 812 while (true) { 813 struct bpf_map_info info = {}; 814 __u32 len = sizeof(info); 815 816 err = bpf_map_get_next_id(id, &id); 817 if (err) { 818 if (errno != ENOENT) { 819 p_err("%s", strerror(errno)); 820 goto err_close_fds; 821 } 822 return nb_fds; 823 } 824 825 fd = bpf_map_get_fd_by_id(id); 826 if (fd < 0) { 827 p_err("can't get map by id (%u): %s", 828 id, strerror(errno)); 829 goto err_close_fds; 830 } 831 832 err = bpf_obj_get_info_by_fd(fd, &info, &len); 833 if (err) { 834 p_err("can't get map info (%u): %s", 835 id, strerror(errno)); 836 goto err_close_fd; 837 } 838 839 if (strncmp(name, info.name, BPF_OBJ_NAME_LEN)) { 840 close(fd); 841 continue; 842 } 843 844 if (nb_fds > 0) { 845 tmp = realloc(*fds, (nb_fds + 1) * sizeof(int)); 846 if (!tmp) { 847 p_err("failed to realloc"); 848 goto err_close_fd; 849 } 850 *fds = tmp; 851 } 852 (*fds)[nb_fds++] = fd; 853 } 854 855 err_close_fd: 856 close(fd); 857 err_close_fds: 858 while (--nb_fds >= 0) 859 close((*fds)[nb_fds]); 860 return -1; 861 } 862 863 int map_parse_fds(int *argc, char ***argv, int **fds) 864 { 865 if (is_prefix(**argv, "id")) { 866 unsigned int id; 867 char *endptr; 868 869 NEXT_ARGP(); 870 871 id = strtoul(**argv, &endptr, 0); 872 if (*endptr) { 873 p_err("can't parse %s as ID", **argv); 874 return -1; 875 } 876 NEXT_ARGP(); 877 878 (*fds)[0] = bpf_map_get_fd_by_id(id); 879 if ((*fds)[0] < 0) { 880 p_err("get map by id (%u): %s", id, strerror(errno)); 881 return -1; 882 } 883 return 1; 884 } else if (is_prefix(**argv, "name")) { 885 char *name; 886 887 NEXT_ARGP(); 888 889 name = **argv; 890 if (strlen(name) > BPF_OBJ_NAME_LEN - 1) { 891 p_err("can't parse name"); 892 return -1; 893 } 894 NEXT_ARGP(); 895 896 return map_fd_by_name(name, fds); 897 } else if (is_prefix(**argv, "pinned")) { 898 char *path; 899 900 NEXT_ARGP(); 901 902 path = **argv; 903 NEXT_ARGP(); 904 905 (*fds)[0] = open_obj_pinned_any(path, BPF_OBJ_MAP); 906 if ((*fds)[0] < 0) 907 return -1; 908 return 1; 909 } 910 911 p_err("expected 'id', 'name' or 'pinned', got: '%s'?", **argv); 912 return -1; 913 } 914 915 int map_parse_fd(int *argc, char ***argv) 916 { 917 int *fds = NULL; 918 int nb_fds, fd; 919 920 fds = malloc(sizeof(int)); 921 if (!fds) { 922 p_err("mem alloc failed"); 923 return -1; 924 } 925 nb_fds = map_parse_fds(argc, argv, &fds); 926 if (nb_fds != 1) { 927 if (nb_fds > 1) { 928 p_err("several maps match this handle"); 929 while (nb_fds--) 930 close(fds[nb_fds]); 931 } 932 fd = -1; 933 goto exit_free; 934 } 935 936 fd = fds[0]; 937 exit_free: 938 free(fds); 939 return fd; 940 } 941 942 int map_parse_fd_and_info(int *argc, char ***argv, void *info, __u32 *info_len) 943 { 944 int err; 945 int fd; 946 947 fd = map_parse_fd(argc, argv); 948 if (fd < 0) 949 return -1; 950 951 err = bpf_obj_get_info_by_fd(fd, info, info_len); 952 if (err) { 953 p_err("can't get map info: %s", strerror(errno)); 954 close(fd); 955 return err; 956 } 957 958 return fd; 959 } 960