malmert
6ad2dd2435
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38 lines
818 B
C
38 lines
818 B
C
#include <linux/bpf.h>
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#include <linux/pkt_cls.h>
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#include <bpf/bpf_helpers.h>
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#define PACKET_ID_MASK 0x0FFFFFFF
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#define VERDICT_MASK 0xF0000000
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struct counter_state {
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struct bpf_spin_lock lock;
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__u32 value;
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};
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struct {
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__uint(type, BPF_MAP_TYPE_ARRAY);
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__uint(max_entries, 1);
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__type(key, __u32);
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__type(value, struct counter_state);
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} packet_counter SEC(".maps");
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SEC("classifier")
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int classifier(struct __sk_buff *skb) {
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__u32 key = 0;
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struct counter_state *state = bpf_map_lookup_elem(&packet_counter, &key);
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__u32 next = 1;
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if (state) {
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bpf_spin_lock(&state->lock);
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state->value += 1;
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next = state->value;
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bpf_spin_unlock(&state->lock);
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}
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skb->mark = (skb->mark & VERDICT_MASK) | (next & PACKET_ID_MASK);
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return TC_ACT_OK;
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}
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char LICENSE[] SEC("license") = "GPL";
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