// SPDX-License-Identifier: GPL-2.0
|
/* Copyright (c) 2020 Facebook */
|
#include "bpf_iter.h"
|
#include <bpf/bpf_helpers.h>
|
#include <bpf/bpf_tracing.h>
|
|
char _license[] SEC("license") = "GPL";
|
|
struct key_t {
|
int a;
|
int b;
|
int c;
|
};
|
|
struct {
|
__uint(type, BPF_MAP_TYPE_HASH);
|
__uint(max_entries, 3);
|
__type(key, struct key_t);
|
__type(value, __u64);
|
} hashmap1 SEC(".maps");
|
|
struct {
|
__uint(type, BPF_MAP_TYPE_HASH);
|
__uint(max_entries, 3);
|
__type(key, __u64);
|
__type(value, __u64);
|
} hashmap2 SEC(".maps");
|
|
struct {
|
__uint(type, BPF_MAP_TYPE_HASH);
|
__uint(max_entries, 3);
|
__type(key, struct key_t);
|
__type(value, __u32);
|
} hashmap3 SEC(".maps");
|
|
/* will set before prog run */
|
bool in_test_mode = 0;
|
|
/* will collect results during prog run */
|
__u32 key_sum_a = 0, key_sum_b = 0, key_sum_c = 0;
|
__u64 val_sum = 0;
|
|
SEC("iter/bpf_map_elem")
|
int dump_bpf_hash_map(struct bpf_iter__bpf_map_elem *ctx)
|
{
|
struct seq_file *seq = ctx->meta->seq;
|
__u32 seq_num = ctx->meta->seq_num;
|
struct bpf_map *map = ctx->map;
|
struct key_t *key = ctx->key;
|
struct key_t tmp_key;
|
__u64 *val = ctx->value;
|
__u64 tmp_val = 0;
|
int ret;
|
|
if (in_test_mode) {
|
/* test mode is used by selftests to
|
* test functionality of bpf_hash_map iter.
|
*
|
* the above hashmap1 will have correct size
|
* and will be accepted, hashmap2 and hashmap3
|
* should be rejected due to smaller key/value
|
* size.
|
*/
|
if (key == (void *)0 || val == (void *)0)
|
return 0;
|
|
/* update the value and then delete the <key, value> pair.
|
* it should not impact the existing 'val' which is still
|
* accessible under rcu.
|
*/
|
__builtin_memcpy(&tmp_key, key, sizeof(struct key_t));
|
ret = bpf_map_update_elem(&hashmap1, &tmp_key, &tmp_val, 0);
|
if (ret)
|
return 0;
|
ret = bpf_map_delete_elem(&hashmap1, &tmp_key);
|
if (ret)
|
return 0;
|
|
key_sum_a += key->a;
|
key_sum_b += key->b;
|
key_sum_c += key->c;
|
val_sum += *val;
|
return 0;
|
}
|
|
/* non-test mode, the map is prepared with the
|
* below bpftool command sequence:
|
* bpftool map create /sys/fs/bpf/m1 type hash \
|
* key 12 value 8 entries 3 name map1
|
* bpftool map update id 77 key 0 0 0 1 0 0 0 0 0 0 0 1 \
|
* value 0 0 0 1 0 0 0 1
|
* bpftool map update id 77 key 0 0 0 1 0 0 0 0 0 0 0 2 \
|
* value 0 0 0 1 0 0 0 2
|
* The bpftool iter command line:
|
* bpftool iter pin ./bpf_iter_bpf_hash_map.o /sys/fs/bpf/p1 \
|
* map id 77
|
* The below output will be:
|
* map dump starts
|
* 77: (1000000 0 2000000) (200000001000000)
|
* 77: (1000000 0 1000000) (100000001000000)
|
* map dump ends
|
*/
|
if (seq_num == 0)
|
BPF_SEQ_PRINTF(seq, "map dump starts\n");
|
|
if (key == (void *)0 || val == (void *)0) {
|
BPF_SEQ_PRINTF(seq, "map dump ends\n");
|
return 0;
|
}
|
|
BPF_SEQ_PRINTF(seq, "%d: (%x %d %x) (%llx)\n", map->id,
|
key->a, key->b, key->c, *val);
|
|
return 0;
|
}
|
