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#include <linux/bpf.h>
#include "bpf_helpers.h"
#include "bpf_util.h"
#include "bpf_endian.h"
int _version SEC("version") = 1;
#define bpf_printk(fmt, ...) \
({ \
char ____fmt[] = fmt; \
bpf_trace_printk(____fmt, sizeof(____fmt), \
##__VA_ARGS__); \
})
struct bpf_map_def SEC("maps") sock_map = {
.type = BPF_MAP_TYPE_SOCKMAP,
.key_size = sizeof(int),
.value_size = sizeof(int),
.max_entries = 20,
};
SEC("sk_skb2")
int bpf_prog2(struct __sk_buff *skb)
{
void *data_end = (void *)(long) skb->data_end;
void *data = (void *)(long) skb->data;
__u32 lport = skb->local_port;
__u32 rport = skb->remote_port;
char *d = data;
if (data + 8 > data_end)
return SK_DROP;
d[0] = 0xd;
d[1] = 0xe;
d[2] = 0xa;
d[3] = 0xd;
d[4] = 0xb;
d[5] = 0xe;
d[6] = 0xe;
d[7] = 0xf;
bpf_printk("verdict: data[0] = (%u): local_port %i remote %i redirect 5\n",
d[0], lport, bpf_ntohl(rport));
return bpf_sk_redirect_map(&sock_map, 5, 0);
}
char _license[] SEC("license") = "GPL";
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