ebpf_exporter

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#include <vmlinux.h>
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#include <bpf/bpf_core_read.h>
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#include <bpf/bpf_tracing.h>
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#include "maps.bpf.h"
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struct inet_frags_key_t {
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    u32 ifindex;
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    u8 ip_version;
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};
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struct {
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    __uint(type, BPF_MAP_TYPE_LRU_HASH);
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    __uint(max_entries, 64);
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    __type(key, struct inet_frags_key_t);
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    __type(value, u64);
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} inet_frags_total SEC(".maps");
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static __always_inline void increment_map_for_skb(void *map, struct sk_buff *skb)
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{
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    void *skb_head = BPF_CORE_READ(skb, head);
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    u16 skb_l3_off = BPF_CORE_READ(skb, network_header);
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    struct iphdr *iph = (struct iphdr *) (skb_head + skb_l3_off);
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    struct inet_frags_key_t key = { 0 };
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    key.ip_version = BPF_CORE_READ_BITFIELD_PROBED(iph, version);
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    key.ifindex = BPF_CORE_READ(skb, skb_iif);
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    increment_map(map, &key, 1);
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}
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SEC("kprobe/inet_frag_queue_insert")
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int BPF_KPROBE(inet_frag_queue_insert, struct inet_frag_queue *q, struct sk_buff *skb, int offset)
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{
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    increment_map_for_skb(&inet_frags_total, skb);
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    return 0;
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}
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char LICENSE[] SEC("license") = "GPL";
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