1#include <linux/bpf.h> 2#include "bpf_helpers.h" 3#include "bpf_util.h" 4#include "bpf_endian.h" 5 6int _version SEC("version") = 1; 7 8#define bpf_printk(fmt, ...) \ 9({ \ 10 char ____fmt[] = fmt; \ 11 bpf_trace_printk(____fmt, sizeof(____fmt), \ 12 ##__VA_ARGS__); \ 13}) 14 15SEC("sk_msg1") 16int bpf_prog1(struct sk_msg_md *msg) 17{ 18 void *data_end = (void *)(long) msg->data_end; 19 void *data = (void *)(long) msg->data; 20 21 char *d; 22 23 if (data + 8 > data_end) 24 return SK_DROP; 25 26 bpf_printk("data length %i\n", (__u64)msg->data_end - (__u64)msg->data); 27 d = (char *)data; 28 bpf_printk("hello sendmsg hook %i %i\n", d[0], d[1]); 29 30 return SK_PASS; 31} 32 33char _license[] SEC("license") = "GPL"; 34