tools/bpf/bpftool/common.c

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