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(*argv, "map")) {
33			NEXT_ARG();
34
35			if (!REQ_ARGS(2)) {
36				p_err("incorrect map spec");
37				return -1;
38			}
39
40			map_fd = map_parse_fd(&argc, &argv);
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("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("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("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("attach_iter failed for program %s",
75		      bpf_program__name(prog));
76		goto close_obj;
77	}
78
79	err = mount_bpffs_for_pin(path, false);
80	if (err)
81		goto close_link;
82
83	err = bpf_link__pin(link, path);
84	if (err) {
85		p_err("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, do_help);
123}
124