LXR linux/tools/bpf/bpftool/iter.c

   1// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
   2// Copyright (C) 2020 Facebook
   3
   4#define _GNU_SOURCE
   5#include <unistd.h>
   6#include <linux/err.h>
   7#include <bpf/libbpf.h>
   8
   9#include "main.h"
  10
  11static int do_pin(int argc, char **argv)
  12{
  13        DECLARE_LIBBPF_OPTS(bpf_iter_attach_opts, iter_opts);
  14        union bpf_iter_link_info linfo;
  15        const char *objfile, *path;
  16        struct bpf_program *prog;
  17        struct bpf_object *obj;
  18        struct bpf_link *link;
  19        int err = -1, map_fd = -1;
  20
  21        if (!REQ_ARGS(2))
  22                usage();
  23
  24        objfile = GET_ARG();
  25        path = GET_ARG();
  26
  27        /* optional arguments */
  28        if (argc) {
  29                if (is_prefix(*argv, "map")) {
  30                        NEXT_ARG();
  31
  32                        if (!REQ_ARGS(2)) {
  33                                p_err("incorrect map spec");
  34                                return -1;
  35                        }
  36
  37                        map_fd = map_parse_fd(&argc, &argv);
  38                        if (map_fd < 0)
  39                                return -1;
  40
  41                        memset(&linfo, 0, sizeof(linfo));
  42                        linfo.map.map_fd = map_fd;
  43                        iter_opts.link_info = &linfo;
  44                        iter_opts.link_info_len = sizeof(linfo);
  45                }
  46        }
  47
  48        obj = bpf_object__open(objfile);
  49        if (IS_ERR(obj)) {
  50                p_err("can't open objfile %s", objfile);
  51                goto close_map_fd;
  52        }
  53
  54        err = bpf_object__load(obj);
  55        if (err) {
  56                p_err("can't load objfile %s", objfile);
  57                goto close_obj;
  58        }
  59
  60        prog = bpf_program__next(NULL, obj);
  61        if (!prog) {
  62                p_err("can't find bpf program in objfile %s", objfile);
  63                goto close_obj;
  64        }
  65
  66        link = bpf_program__attach_iter(prog, &iter_opts);
  67        if (IS_ERR(link)) {
  68                err = PTR_ERR(link);
  69                p_err("attach_iter failed for program %s",
  70                      bpf_program__name(prog));
  71                goto close_obj;
  72        }
  73
  74        err = mount_bpffs_for_pin(path);
  75        if (err)
  76                goto close_link;
  77
  78        err = bpf_link__pin(link, path);
  79        if (err) {
  80                p_err("pin_iter failed for program %s to path %s",
  81                      bpf_program__name(prog), path);
  82                goto close_link;
  83        }
  84
  85close_link:
  86        bpf_link__destroy(link);
  87close_obj:
  88        bpf_object__close(obj);
  89close_map_fd:
  90        if (map_fd >= 0)
  91                close(map_fd);
  92        return err;
  93}
  94
  95static int do_help(int argc, char **argv)
  96{
  97        fprintf(stderr,
  98                "Usage: %1$s %2$s pin OBJ PATH [map MAP]\n"
  99                "       %1$s %2$s help\n"
 100                "\n"
 101                "       " HELP_SPEC_MAP "\n"
 102                "       " HELP_SPEC_OPTIONS " }\n"
 103                "",
 104                bin_name, "iter");
 105
 106        return 0;
 107}
 108
 109static const struct cmd cmds[] = {
 110        { "help",       do_help },
 111        { "pin",        do_pin },
 112        { 0 }
 113};
 114
 115int do_iter(int argc, char **argv)
 116{
 117        return cmd_select(cmds, argc, argv, do_help);
 118}
 119