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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__); \
})
SEC("sk_skb1")
int bpf_prog1(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 skb->len;
/* This write/read is a bit pointless but tests the verifier and
* strparser handler for read/write pkt data and access into sk
* fields.
*/
d[0] = 1;
bpf_printk("data[0] = (%u): local_port %i remote %i\n",
d[0], lport, bpf_ntohl(rport));
return skb->len;
}
char _license[] SEC("license") = "GPL";
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