1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
|
// SPDX-License-Identifier: GPL-2.0-only
/* Copyright (c) 2020 Facebook */
#include <linux/bpf.h>
#include <linux/fs.h>
#include <linux/filter.h>
#include <linux/kernel.h>
#include <linux/btf_ids.h>
struct bpf_iter_seq_map_info {
u32 map_id;
};
static void *bpf_map_seq_start(struct seq_file *seq, loff_t *pos)
{
struct bpf_iter_seq_map_info *info = seq->private;
struct bpf_map *map;
map = bpf_map_get_curr_or_next(&info->map_id);
if (!map)
return NULL;
if (*pos == 0)
++*pos;
return map;
}
static void *bpf_map_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
struct bpf_iter_seq_map_info *info = seq->private;
++*pos;
++info->map_id;
bpf_map_put((struct bpf_map *)v);
return bpf_map_get_curr_or_next(&info->map_id);
}
struct bpf_iter__bpf_map {
__bpf_md_ptr(struct bpf_iter_meta *, meta);
__bpf_md_ptr(struct bpf_map *, map);
};
DEFINE_BPF_ITER_FUNC(bpf_map, struct bpf_iter_meta *meta, struct bpf_map *map)
static int __bpf_map_seq_show(struct seq_file *seq, void *v, bool in_stop)
{
struct bpf_iter__bpf_map ctx;
struct bpf_iter_meta meta;
struct bpf_prog *prog;
int ret = 0;
ctx.meta = &meta;
ctx.map = v;
meta.seq = seq;
prog = bpf_iter_get_info(&meta, in_stop);
if (prog)
ret = bpf_iter_run_prog(prog, &ctx);
return ret;
}
static int bpf_map_seq_show(struct seq_file *seq, void *v)
{
return __bpf_map_seq_show(seq, v, false);
}
static void bpf_map_seq_stop(struct seq_file *seq, void *v)
{
if (!v)
(void)__bpf_map_seq_show(seq, v, true);
else
bpf_map_put((struct bpf_map *)v);
}
static const struct seq_operations bpf_map_seq_ops = {
.start = bpf_map_seq_start,
.next = bpf_map_seq_next,
.stop = bpf_map_seq_stop,
.show = bpf_map_seq_show,
};
BTF_ID_LIST_GLOBAL_SINGLE(btf_bpf_map_id, struct, bpf_map)
static const struct bpf_iter_seq_info bpf_map_seq_info = {
.seq_ops = &bpf_map_seq_ops,
.init_seq_private = NULL,
.fini_seq_private = NULL,
.seq_priv_size = sizeof(struct bpf_iter_seq_map_info),
};
static struct bpf_iter_reg bpf_map_reg_info = {
.target = "bpf_map",
.ctx_arg_info_size = 1,
.ctx_arg_info = {
{ offsetof(struct bpf_iter__bpf_map, map),
PTR_TO_BTF_ID_OR_NULL | PTR_TRUSTED },
},
.seq_info = &bpf_map_seq_info,
};
static int bpf_iter_attach_map(struct bpf_prog *prog,
union bpf_iter_link_info *linfo,
struct bpf_iter_aux_info *aux)
{
u32 key_acc_size, value_acc_size, key_size, value_size;
struct bpf_map *map;
bool is_percpu = false;
int err = -EINVAL;
if (!linfo->map.map_fd)
return -EBADF;
map = bpf_map_get_with_uref(linfo->map.map_fd);
if (IS_ERR(map))
return PTR_ERR(map);
if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH ||
map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY)
is_percpu = true;
else if (map->map_type != BPF_MAP_TYPE_HASH &&
map->map_type != BPF_MAP_TYPE_LRU_HASH &&
map->map_type != BPF_MAP_TYPE_ARRAY)
goto put_map;
key_acc_size = prog->aux->max_rdonly_access;
value_acc_size = prog->aux->max_rdwr_access;
key_size = map->key_size;
if (!is_percpu)
value_size = map->value_size;
else
value_size = round_up(map->value_size, 8) * num_possible_cpus();
if (key_acc_size > key_size || value_acc_size > value_size) {
err = -EACCES;
goto put_map;
}
aux->map = map;
return 0;
put_map:
bpf_map_put_with_uref(map);
return err;
}
static void bpf_iter_detach_map(struct bpf_iter_aux_info *aux)
{
bpf_map_put_with_uref(aux->map);
}
void bpf_iter_map_show_fdinfo(const struct bpf_iter_aux_info *aux,
struct seq_file *seq)
{
seq_printf(seq, "map_id:\t%u\n", aux->map->id);
}
int bpf_iter_map_fill_link_info(const struct bpf_iter_aux_info *aux,
struct bpf_link_info *info)
{
info->iter.map.map_id = aux->map->id;
return 0;
}
DEFINE_BPF_ITER_FUNC(bpf_map_elem, struct bpf_iter_meta *meta,
struct bpf_map *map, void *key, void *value)
static const struct bpf_iter_reg bpf_map_elem_reg_info = {
.target = "bpf_map_elem",
.attach_target = bpf_iter_attach_map,
.detach_target = bpf_iter_detach_map,
.show_fdinfo = bpf_iter_map_show_fdinfo,
.fill_link_info = bpf_iter_map_fill_link_info,
.ctx_arg_info_size = 2,
.ctx_arg_info = {
{ offsetof(struct bpf_iter__bpf_map_elem, key),
PTR_TO_BUF | PTR_MAYBE_NULL | MEM_RDONLY },
{ offsetof(struct bpf_iter__bpf_map_elem, value),
PTR_TO_BUF | PTR_MAYBE_NULL },
},
};
static int __init bpf_map_iter_init(void)
{
int ret;
bpf_map_reg_info.ctx_arg_info[0].btf_id = *btf_bpf_map_id;
ret = bpf_iter_reg_target(&bpf_map_reg_info);
if (ret)
return ret;
return bpf_iter_reg_target(&bpf_map_elem_reg_info);
}
late_initcall(bpf_map_iter_init);
__bpf_kfunc_start_defs();
__bpf_kfunc s64 bpf_map_sum_elem_count(const struct bpf_map *map)
{
s64 *pcount;
s64 ret = 0;
int cpu;
if (!map || !map->elem_count)
return 0;
for_each_possible_cpu(cpu) {
pcount = per_cpu_ptr(map->elem_count, cpu);
ret += READ_ONCE(*pcount);
}
return ret;
}
__bpf_kfunc_end_defs();
BTF_KFUNCS_START(bpf_map_iter_kfunc_ids)
BTF_ID_FLAGS(func, bpf_map_sum_elem_count, KF_TRUSTED_ARGS)
BTF_KFUNCS_END(bpf_map_iter_kfunc_ids)
static const struct btf_kfunc_id_set bpf_map_iter_kfunc_set = {
.owner = THIS_MODULE,
.set = &bpf_map_iter_kfunc_ids,
};
static int init_subsystem(void)
{
return register_btf_kfunc_id_set(BPF_PROG_TYPE_UNSPEC, &bpf_map_iter_kfunc_set);
}
late_initcall(init_subsystem);
|
