1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* Copyright (c) 2022 Red Hat, Inc. */ |
3 | #include <linux/bpf.h> |
4 | #include <linux/fs.h> |
5 | #include <linux/filter.h> |
6 | #include <linux/kernel.h> |
7 | #include <linux/btf_ids.h> |
8 | |
9 | struct bpf_iter_seq_link_info { |
10 | u32 link_id; |
11 | }; |
12 | |
13 | static void *bpf_link_seq_start(struct seq_file *seq, loff_t *pos) |
14 | { |
15 | struct bpf_iter_seq_link_info *info = seq->private; |
16 | struct bpf_link *link; |
17 | |
18 | link = bpf_link_get_curr_or_next(id: &info->link_id); |
19 | if (!link) |
20 | return NULL; |
21 | |
22 | if (*pos == 0) |
23 | ++*pos; |
24 | return link; |
25 | } |
26 | |
27 | static void *bpf_link_seq_next(struct seq_file *seq, void *v, loff_t *pos) |
28 | { |
29 | struct bpf_iter_seq_link_info *info = seq->private; |
30 | |
31 | ++*pos; |
32 | ++info->link_id; |
33 | bpf_link_put(link: (struct bpf_link *)v); |
34 | return bpf_link_get_curr_or_next(id: &info->link_id); |
35 | } |
36 | |
37 | struct bpf_iter__bpf_link { |
38 | __bpf_md_ptr(struct bpf_iter_meta *, meta); |
39 | __bpf_md_ptr(struct bpf_link *, link); |
40 | }; |
41 | |
42 | DEFINE_BPF_ITER_FUNC(bpf_link, struct bpf_iter_meta *meta, struct bpf_link *link) |
43 | |
44 | static int __bpf_link_seq_show(struct seq_file *seq, void *v, bool in_stop) |
45 | { |
46 | struct bpf_iter__bpf_link ctx; |
47 | struct bpf_iter_meta meta; |
48 | struct bpf_prog *prog; |
49 | int ret = 0; |
50 | |
51 | ctx.meta = &meta; |
52 | ctx.link = v; |
53 | meta.seq = seq; |
54 | prog = bpf_iter_get_info(meta: &meta, in_stop); |
55 | if (prog) |
56 | ret = bpf_iter_run_prog(prog, ctx: &ctx); |
57 | |
58 | return ret; |
59 | } |
60 | |
61 | static int bpf_link_seq_show(struct seq_file *seq, void *v) |
62 | { |
63 | return __bpf_link_seq_show(seq, v, in_stop: false); |
64 | } |
65 | |
66 | static void bpf_link_seq_stop(struct seq_file *seq, void *v) |
67 | { |
68 | if (!v) |
69 | (void)__bpf_link_seq_show(seq, v, in_stop: true); |
70 | else |
71 | bpf_link_put(link: (struct bpf_link *)v); |
72 | } |
73 | |
74 | static const struct seq_operations bpf_link_seq_ops = { |
75 | .start = bpf_link_seq_start, |
76 | .next = bpf_link_seq_next, |
77 | .stop = bpf_link_seq_stop, |
78 | .show = bpf_link_seq_show, |
79 | }; |
80 | |
81 | BTF_ID_LIST(btf_bpf_link_id) |
82 | BTF_ID(struct, bpf_link) |
83 | |
84 | static const struct bpf_iter_seq_info bpf_link_seq_info = { |
85 | .seq_ops = &bpf_link_seq_ops, |
86 | .init_seq_private = NULL, |
87 | .fini_seq_private = NULL, |
88 | .seq_priv_size = sizeof(struct bpf_iter_seq_link_info), |
89 | }; |
90 | |
91 | static struct bpf_iter_reg bpf_link_reg_info = { |
92 | .target = "bpf_link" , |
93 | .ctx_arg_info_size = 1, |
94 | .ctx_arg_info = { |
95 | { offsetof(struct bpf_iter__bpf_link, link), |
96 | PTR_TO_BTF_ID_OR_NULL }, |
97 | }, |
98 | .seq_info = &bpf_link_seq_info, |
99 | }; |
100 | |
101 | static int __init bpf_link_iter_init(void) |
102 | { |
103 | bpf_link_reg_info.ctx_arg_info[0].btf_id = *btf_bpf_link_id; |
104 | return bpf_iter_reg_target(reg_info: &bpf_link_reg_info); |
105 | } |
106 | |
107 | late_initcall(bpf_link_iter_init); |
108 | |