1
2
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, 3);
11 __type(key, __u32);
12 __type(value, __u64);
13} hashmap SEC(".maps");
14
15struct {
16 __uint(type, BPF_MAP_TYPE_PERCPU_HASH);
17 __uint(max_entries, 1);
18 __type(key, __u32);
19 __type(value, __u64);
20} percpu_map SEC(".maps");
21
22struct callback_ctx {
23 struct __sk_buff *ctx;
24 int input;
25 int output;
26};
27
28static __u64
29check_hash_elem(struct bpf_map *map, __u32 *key, __u64 *val,
30 struct callback_ctx *data)
31{
32 struct __sk_buff *skb = data->ctx;
33 __u32 k;
34 __u64 v;
35
36 if (skb) {
37 k = *key;
38 v = *val;
39 if (skb->len == 10000 && k == 10 && v == 10)
40 data->output = 3;
41 else
42 data->output = 4;
43 } else {
44 data->output = data->input;
45 bpf_map_delete_elem(map, key);
46 }
47
48 return 0;
49}
50
51__u32 cpu = 0;
52__u32 percpu_called = 0;
53__u32 percpu_key = 0;
54__u64 percpu_val = 0;
55int percpu_output = 0;
56
57static __u64
58check_percpu_elem(struct bpf_map *map, __u32 *key, __u64 *val,
59 struct callback_ctx *unused)
60{
61 struct callback_ctx data;
62
63 percpu_called++;
64 cpu = bpf_get_smp_processor_id();
65 percpu_key = *key;
66 percpu_val = *val;
67
68 data.ctx = 0;
69 data.input = 100;
70 data.output = 0;
71 bpf_for_each_map_elem(&hashmap, check_hash_elem, &data, 0);
72 percpu_output = data.output;
73
74 return 0;
75}
76
77int hashmap_output = 0;
78int hashmap_elems = 0;
79int percpu_map_elems = 0;
80
81SEC("classifier")
82int test_pkt_access(struct __sk_buff *skb)
83{
84 struct callback_ctx data;
85
86 data.ctx = skb;
87 data.input = 10;
88 data.output = 0;
89 hashmap_elems = bpf_for_each_map_elem(&hashmap, check_hash_elem, &data, 0);
90 hashmap_output = data.output;
91
92 percpu_map_elems = bpf_for_each_map_elem(&percpu_map, check_percpu_elem,
93 (void *)0, 0);
94 return 0;
95}
96
