for_each_hash_modify.c

 1// SPDX-License-Identifier: GPL-2.0
 2/* Copyright (c) 2025 Intel Corporation */
 3#include "vmlinux.h"
 4#include <bpf/bpf_helpers.h>
 5
 6char _license[] SEC("license") = "GPL";
 7
 8struct {
 9	__uint(type, BPF_MAP_TYPE_HASH);
10	__uint(max_entries, 128);
11	__type(key, __u64);
12	__type(value, __u64);
13} hashmap SEC(".maps");
14
15static int cb(struct bpf_map *map, __u64 *key, __u64 *val, void *arg)
16{
17	bpf_map_delete_elem(map, key);
18	bpf_map_update_elem(map, key, val, 0);
19	return 0;
20}
21
22SEC("tc")
23int test_pkt_access(struct __sk_buff *skb)
24{
25	(void)skb;
26
27	bpf_for_each_map_elem(&hashmap, cb, NULL, 0);
28
29	return 0;
30}