1// SPDX-License-Identifier: GPL-2.0
 2#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 3#include <linux/init.h>
 4#include <linux/module.h>
 5#include "bpf_preload.h"
 6#include "iterators/iterators.lskel.h"
 
 
 
 
 7
 8static struct bpf_link *maps_link, *progs_link;
 9static struct iterators_bpf *skel;
10
11static void free_links_and_skel(void)
12{
13	if (!IS_ERR_OR_NULL(maps_link))
14		bpf_link_put(maps_link);
15	if (!IS_ERR_OR_NULL(progs_link))
16		bpf_link_put(progs_link);
17	iterators_bpf__destroy(skel);
18}
19
20static int preload(struct bpf_preload_info *obj)
21{
22	strlcpy(obj[0].link_name, "maps.debug", sizeof(obj[0].link_name));
23	obj[0].link = maps_link;
24	strlcpy(obj[1].link_name, "progs.debug", sizeof(obj[1].link_name));
25	obj[1].link = progs_link;
26	return 0;
27}
28
29static struct bpf_preload_ops ops = {
30	.preload = preload,
31	.owner = THIS_MODULE,
32};
33
34static int load_skel(void)
35{
36	int err;
37
38	skel = iterators_bpf__open();
39	if (!skel)
40		return -ENOMEM;
41	err = iterators_bpf__load(skel);
42	if (err)
43		goto out;
44	err = iterators_bpf__attach(skel);
45	if (err)
46		goto out;
47	maps_link = bpf_link_get_from_fd(skel->links.dump_bpf_map_fd);
48	if (IS_ERR(maps_link)) {
49		err = PTR_ERR(maps_link);
50		goto out;
51	}
52	progs_link = bpf_link_get_from_fd(skel->links.dump_bpf_prog_fd);
53	if (IS_ERR(progs_link)) {
54		err = PTR_ERR(progs_link);
55		goto out;
56	}
57	/* Avoid taking over stdin/stdout/stderr of init process. Zeroing out
58	 * makes skel_closenz() a no-op later in iterators_bpf__destroy().
59	 */
60	close_fd(skel->links.dump_bpf_map_fd);
61	skel->links.dump_bpf_map_fd = 0;
62	close_fd(skel->links.dump_bpf_prog_fd);
63	skel->links.dump_bpf_prog_fd = 0;
64	return 0;
65out:
66	free_links_and_skel();
67	return err;
68}
69
70static int __init load(void)
71{
72	int err;
73
74	err = load_skel();
75	if (err)
76		return err;
77	bpf_preload_ops = &ops;
78	return err;
79}
80
81static void __exit fini(void)
82{
83	bpf_preload_ops = NULL;
84	free_links_and_skel();
85}
86late_initcall(load);
87module_exit(fini);
88MODULE_LICENSE("GPL");

 1// SPDX-License-Identifier: GPL-2.0
 2#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 3#include <linux/init.h>
 4#include <linux/module.h>
 5#include "bpf_preload.h"
 6#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
 7#include "iterators/iterators.lskel-little-endian.h"
 8#else
 9#include "iterators/iterators.lskel-big-endian.h"
10#endif
11
12static struct bpf_link *maps_link, *progs_link;
13static struct iterators_bpf *skel;
14
15static void free_links_and_skel(void)
16{
17	if (!IS_ERR_OR_NULL(maps_link))
18		bpf_link_put(maps_link);
19	if (!IS_ERR_OR_NULL(progs_link))
20		bpf_link_put(progs_link);
21	iterators_bpf__destroy(skel);
22}
23
24static int preload(struct bpf_preload_info *obj)
25{
26	strscpy(obj[0].link_name, "maps.debug", sizeof(obj[0].link_name));
27	obj[0].link = maps_link;
28	strscpy(obj[1].link_name, "progs.debug", sizeof(obj[1].link_name));
29	obj[1].link = progs_link;
30	return 0;
31}
32
33static struct bpf_preload_ops ops = {
34	.preload = preload,
35	.owner = THIS_MODULE,
36};
37
38static int load_skel(void)
39{
40	int err;
41
42	skel = iterators_bpf__open();
43	if (!skel)
44		return -ENOMEM;
45	err = iterators_bpf__load(skel);
46	if (err)
47		goto out;
48	err = iterators_bpf__attach(skel);
49	if (err)
50		goto out;
51	maps_link = bpf_link_get_from_fd(skel->links.dump_bpf_map_fd);
52	if (IS_ERR(maps_link)) {
53		err = PTR_ERR(maps_link);
54		goto out;
55	}
56	progs_link = bpf_link_get_from_fd(skel->links.dump_bpf_prog_fd);
57	if (IS_ERR(progs_link)) {
58		err = PTR_ERR(progs_link);
59		goto out;
60	}
61	/* Avoid taking over stdin/stdout/stderr of init process. Zeroing out
62	 * makes skel_closenz() a no-op later in iterators_bpf__destroy().
63	 */
64	close_fd(skel->links.dump_bpf_map_fd);
65	skel->links.dump_bpf_map_fd = 0;
66	close_fd(skel->links.dump_bpf_prog_fd);
67	skel->links.dump_bpf_prog_fd = 0;
68	return 0;
69out:
70	free_links_and_skel();
71	return err;
72}
73
74static int __init load(void)
75{
76	int err;
77
78	err = load_skel();
79	if (err)
80		return err;
81	bpf_preload_ops = &ops;
82	return err;
83}
84
85static void __exit fini(void)
86{
87	bpf_preload_ops = NULL;
88	free_links_and_skel();
89}
90late_initcall(load);
91module_exit(fini);
92MODULE_LICENSE("GPL");