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// 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;
}
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