xref: /openbmc/linux/tools/bpf/bpftool/iter.c (revision d89775fc)
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 
11 static int do_pin(int argc, char **argv)
12 {
13 	DECLARE_LIBBPF_OPTS(bpf_iter_attach_opts, iter_opts);
14 	const char *objfile, *path;
15 	struct bpf_program *prog;
16 	struct bpf_object *obj;
17 	struct bpf_link *link;
18 	int err = -1, map_fd = -1;
19 
20 	if (!REQ_ARGS(2))
21 		usage();
22 
23 	objfile = GET_ARG();
24 	path = GET_ARG();
25 
26 	/* optional arguments */
27 	if (argc) {
28 		if (is_prefix(*argv, "map")) {
29 			NEXT_ARG();
30 
31 			if (!REQ_ARGS(2)) {
32 				p_err("incorrect map spec");
33 				return -1;
34 			}
35 
36 			map_fd = map_parse_fd(&argc, &argv);
37 			if (map_fd < 0)
38 				return -1;
39 		}
40 	}
41 
42 	obj = bpf_object__open(objfile);
43 	if (IS_ERR(obj)) {
44 		p_err("can't open objfile %s", objfile);
45 		goto close_map_fd;
46 	}
47 
48 	err = bpf_object__load(obj);
49 	if (err) {
50 		p_err("can't load objfile %s", objfile);
51 		goto close_obj;
52 	}
53 
54 	prog = bpf_program__next(NULL, obj);
55 	if (!prog) {
56 		p_err("can't find bpf program in objfile %s", objfile);
57 		goto close_obj;
58 	}
59 
60 	if (map_fd >= 0)
61 		iter_opts.map_fd = map_fd;
62 
63 	link = bpf_program__attach_iter(prog, &iter_opts);
64 	if (IS_ERR(link)) {
65 		err = PTR_ERR(link);
66 		p_err("attach_iter failed for program %s",
67 		      bpf_program__name(prog));
68 		goto close_obj;
69 	}
70 
71 	err = mount_bpffs_for_pin(path);
72 	if (err)
73 		goto close_link;
74 
75 	err = bpf_link__pin(link, path);
76 	if (err) {
77 		p_err("pin_iter failed for program %s to path %s",
78 		      bpf_program__name(prog), path);
79 		goto close_link;
80 	}
81 
82 close_link:
83 	bpf_link__destroy(link);
84 close_obj:
85 	bpf_object__close(obj);
86 close_map_fd:
87 	if (map_fd >= 0)
88 		close(map_fd);
89 	return err;
90 }
91 
92 static int do_help(int argc, char **argv)
93 {
94 	fprintf(stderr,
95 		"Usage: %1$s %2$s pin OBJ PATH [map MAP]\n"
96 		"       %1$s %2$s help\n"
97 		"       " HELP_SPEC_MAP "\n"
98 		"",
99 		bin_name, "iter");
100 
101 	return 0;
102 }
103 
104 static const struct cmd cmds[] = {
105 	{ "help",	do_help },
106 	{ "pin",	do_pin },
107 	{ 0 }
108 };
109 
110 int do_iter(int argc, char **argv)
111 {
112 	return cmd_select(cmds, argc, argv, do_help);
113 }
114