xref: /openbmc/linux/tools/bpf/bpftool/iter.c (revision 6abeae2a)
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 	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 
85 close_link:
86 	bpf_link__destroy(link);
87 close_obj:
88 	bpf_object__close(obj);
89 close_map_fd:
90 	if (map_fd >= 0)
91 		close(map_fd);
92 	return err;
93 }
94 
95 static 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 		"       " HELP_SPEC_MAP "\n"
101 		"",
102 		bin_name, "iter");
103 
104 	return 0;
105 }
106 
107 static const struct cmd cmds[] = {
108 	{ "help",	do_help },
109 	{ "pin",	do_pin },
110 	{ 0 }
111 };
112 
113 int do_iter(int argc, char **argv)
114 {
115 	return cmd_select(cmds, argc, argv, do_help);
116 }
117