1// SPDX-License-Identifier: GPL-2.0
2/* Copyright (c) 2020 Facebook */
3#include <linux/bpf.h>
4#include <bpf/bpf_helpers.h>
5#include <bpf/bpf_core_read.h>
6
7#pragma clang attribute push (__attribute__((preserve_access_index)), apply_to = record)
8struct seq_file;
9struct bpf_iter_meta {
10	struct seq_file *seq;
11	__u64 session_id;
12	__u64 seq_num;
13};
14
15struct bpf_map {
16	__u32 id;
17	char name[16];
18	__u32 max_entries;
19};
20
21struct bpf_iter__bpf_map {
22	struct bpf_iter_meta *meta;
23	struct bpf_map *map;
24};
25
26struct btf_type {
27	__u32 name_off;
28};
29
30struct btf_header {
31	__u32   str_len;
32};
33
34struct btf {
35	const char *strings;
36	struct btf_type **types;
37	struct btf_header hdr;
38};
39
40struct bpf_prog_aux {
41	__u32 id;
42	char name[16];
43	const char *attach_func_name;
44	struct bpf_prog *dst_prog;
45	struct bpf_func_info *func_info;
46	struct btf *btf;
47};
48
49struct bpf_prog {
50	struct bpf_prog_aux *aux;
51};
52
53struct bpf_iter__bpf_prog {
54	struct bpf_iter_meta *meta;
55	struct bpf_prog *prog;
56};
57#pragma clang attribute pop
58
59static const char *get_name(struct btf *btf, long btf_id, const char *fallback)
60{
61	struct btf_type **types, *t;
62	unsigned int name_off;
63	const char *str;
64
65	if (!btf)
66		return fallback;
67	str = btf->strings;
68	types = btf->types;
69	bpf_probe_read_kernel(&t, sizeof(t), types + btf_id);
70	name_off = BPF_CORE_READ(t, name_off);
71	if (name_off >= btf->hdr.str_len)
72		return fallback;
73	return str + name_off;
74}
75
76__s64 bpf_map_sum_elem_count(struct bpf_map *map) __ksym;
77
78SEC("iter/bpf_map")
79int dump_bpf_map(struct bpf_iter__bpf_map *ctx)
80{
81	struct seq_file *seq = ctx->meta->seq;
82	__u64 seq_num = ctx->meta->seq_num;
83	struct bpf_map *map = ctx->map;
84
85	if (!map)
86		return 0;
87
88	if (seq_num == 0)
89		BPF_SEQ_PRINTF(seq, "  id name             max_entries  cur_entries\n");
90
91	BPF_SEQ_PRINTF(seq, "%4u %-16s  %10d   %10lld\n",
92		       map->id, map->name, map->max_entries,
93		       bpf_map_sum_elem_count(map));
94
95	return 0;
96}
97
98SEC("iter/bpf_prog")
99int dump_bpf_prog(struct bpf_iter__bpf_prog *ctx)
100{
101	struct seq_file *seq = ctx->meta->seq;
102	__u64 seq_num = ctx->meta->seq_num;
103	struct bpf_prog *prog = ctx->prog;
104	struct bpf_prog_aux *aux;
105
106	if (!prog)
107		return 0;
108
109	aux = prog->aux;
110	if (seq_num == 0)
111		BPF_SEQ_PRINTF(seq, "  id name             attached\n");
112
113	BPF_SEQ_PRINTF(seq, "%4u %-16s %s %s\n", aux->id,
114		       get_name(aux->btf, aux->func_info[0].type_id, aux->name),
115		       aux->attach_func_name, aux->dst_prog->aux->name);
116	return 0;
117}
118char LICENSE[] SEC("license") = "GPL";
119