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