68 lines · c
1#include <linux/bpf.h>2#include <bpf/bpf_helpers.h>3#include <bpf/bpf_endian.h>4#include "bpf_misc.h"5 6struct {7 __uint(type, BPF_MAP_TYPE_SOCKMAP);8 __uint(max_entries, 20);9 __type(key, int);10 __type(value, int);11} sock_map_rx SEC(".maps");12 13struct {14 __uint(type, BPF_MAP_TYPE_SOCKMAP);15 __uint(max_entries, 20);16 __type(key, int);17 __type(value, int);18} sock_map_tx SEC(".maps");19 20struct {21 __uint(type, BPF_MAP_TYPE_SOCKMAP);22 __uint(max_entries, 20);23 __type(key, int);24 __type(value, int);25} sock_map_msg SEC(".maps");26 27struct {28 __uint(type, BPF_MAP_TYPE_ARRAY);29 __uint(max_entries, 20);30 __type(key, int);31 __type(value, int);32} sock_map_break SEC(".maps");33 34SEC("sk_skb2")35int bpf_prog2(struct __sk_buff *skb)36{37 void *data_end = (void *)(long) skb->data_end;38 void *data = (void *)(long) skb->data;39 __u32 lport = skb->local_port;40 __u32 rport = skb->remote_port;41 __u8 *d = data;42 __u8 sk, map;43 44 __sink(lport);45 __sink(rport);46 47 if (data + 8 > data_end)48 return SK_DROP;49 50 map = d[0];51 sk = d[1];52 53 d[0] = 0xd;54 d[1] = 0xe;55 d[2] = 0xa;56 d[3] = 0xd;57 d[4] = 0xb;58 d[5] = 0xe;59 d[6] = 0xe;60 d[7] = 0xf;61 62 if (!map)63 return bpf_sk_redirect_map(skb, &sock_map_rx, sk, 0);64 return bpf_sk_redirect_map(skb, &sock_map_tx, sk, 0);65}66 67char _license[] SEC("license") = "GPL";68