1// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
2// Copyright (C) 2020 Facebook
3
4#ifndef _GNU_SOURCE
5#define _GNU_SOURCE
6#endif
7#include <errno.h>
8#include <unistd.h>
9#include <linux/err.h>
10#include <bpf/libbpf.h>
11
12#include "main.h"
13
14static int do_pin(int argc, char **argv)
15{
16 DECLARE_LIBBPF_OPTS(bpf_iter_attach_opts, iter_opts);
17 union bpf_iter_link_info linfo;
18 const char *objfile, *path;
19 struct bpf_program *prog;
20 struct bpf_object *obj;
21 struct bpf_link *link;
22 int err = -1, map_fd = -1;
23
24 if (!REQ_ARGS(2))
25 usage();
26
27 objfile = GET_ARG();
28 path = GET_ARG();
29
30 /* optional arguments */
31 if (argc) {
32 if (is_prefix(pfx: *argv, str: "map")) {
33 NEXT_ARG();
34
35 if (!REQ_ARGS(2)) {
36 p_err(fmt: "incorrect map spec");
37 return -1;
38 }
39
40 map_fd = map_parse_fd(argc: &argc, argv: &argv, open_flags: BPF_F_RDONLY);
41 if (map_fd < 0)
42 return -1;
43
44 memset(&linfo, 0, sizeof(linfo));
45 linfo.map.map_fd = map_fd;
46 iter_opts.link_info = &linfo;
47 iter_opts.link_info_len = sizeof(linfo);
48 }
49 }
50
51 obj = bpf_object__open(objfile);
52 if (!obj) {
53 err = -errno;
54 p_err(fmt: "can't open objfile %s", objfile);
55 goto close_map_fd;
56 }
57
58 err = bpf_object__load(obj);
59 if (err) {
60 p_err(fmt: "can't load objfile %s", objfile);
61 goto close_obj;
62 }
63
64 prog = bpf_object__next_program(obj, NULL);
65 if (!prog) {
66 err = -errno;
67 p_err(fmt: "can't find bpf program in objfile %s", objfile);
68 goto close_obj;
69 }
70
71 link = bpf_program__attach_iter(prog, &iter_opts);
72 if (!link) {
73 err = -errno;
74 p_err(fmt: "attach_iter failed for program %s",
75 bpf_program__name(prog));
76 goto close_obj;
77 }
78
79 err = mount_bpffs_for_file(file_name: path);
80 if (err)
81 goto close_link;
82
83 err = bpf_link__pin(link, path);
84 if (err) {
85 p_err(fmt: "pin_iter failed for program %s to path %s",
86 bpf_program__name(prog), path);
87 goto close_link;
88 }
89
90close_link:
91 bpf_link__destroy(link);
92close_obj:
93 bpf_object__close(obj);
94close_map_fd:
95 if (map_fd >= 0)
96 close(map_fd);
97 return err;
98}
99
100static int do_help(int argc, char **argv)
101{
102 fprintf(stderr,
103 "Usage: %1$s %2$s pin OBJ PATH [map MAP]\n"
104 " %1$s %2$s help\n"
105 "\n"
106 " " HELP_SPEC_MAP "\n"
107 " " HELP_SPEC_OPTIONS " }\n"
108 "",
109 bin_name, "iter");
110
111 return 0;
112}
113
114static const struct cmd cmds[] = {
115 { "help", do_help },
116 { "pin", do_pin },
117 { 0 }
118};
119
120int do_iter(int argc, char **argv)
121{
122 return cmd_select(cmds, argc, argv, help: do_help);
123}
124

source code of linux/tools/bpf/bpftool/iter.c