1 | #include <linux/bpf.h> |
2 | #include <linux/if_ether.h> |
3 | #include <linux/pkt_cls.h> |
4 | |
5 | #include <bpf/bpf_helpers.h> |
6 | |
7 | #define __round_mask(x, y) ((__typeof__(x))((y) - 1)) |
8 | #define round_up(x, y) ((((x) - 1) | __round_mask(x, y)) + 1) |
9 | #define ctx_ptr(ctx, mem) (void *)(unsigned long)ctx->mem |
10 | |
11 | SEC("t" ) |
12 | int ing_cls(struct __sk_buff *ctx) |
13 | { |
14 | __u8 *data, *data_meta, *data_end; |
15 | __u32 diff = 0; |
16 | |
17 | data_meta = ctx_ptr(ctx, data_meta); |
18 | data_end = ctx_ptr(ctx, data_end); |
19 | data = ctx_ptr(ctx, data); |
20 | |
21 | if (data + ETH_ALEN > data_end || |
22 | data_meta + round_up(ETH_ALEN, 4) > data) |
23 | return TC_ACT_SHOT; |
24 | |
25 | diff |= ((__u32 *)data_meta)[0] ^ ((__u32 *)data)[0]; |
26 | diff |= ((__u16 *)data_meta)[2] ^ ((__u16 *)data)[2]; |
27 | |
28 | return diff ? TC_ACT_SHOT : TC_ACT_OK; |
29 | } |
30 | |
31 | SEC("x" ) |
32 | int ing_xdp(struct xdp_md *ctx) |
33 | { |
34 | __u8 *data, *data_meta, *data_end; |
35 | int ret; |
36 | |
37 | ret = bpf_xdp_adjust_meta(ctx, -round_up(ETH_ALEN, 4)); |
38 | if (ret < 0) |
39 | return XDP_DROP; |
40 | |
41 | data_meta = ctx_ptr(ctx, data_meta); |
42 | data_end = ctx_ptr(ctx, data_end); |
43 | data = ctx_ptr(ctx, data); |
44 | |
45 | if (data + ETH_ALEN > data_end || |
46 | data_meta + round_up(ETH_ALEN, 4) > data) |
47 | return XDP_DROP; |
48 | |
49 | __builtin_memcpy(data_meta, data, ETH_ALEN); |
50 | return XDP_PASS; |
51 | } |
52 | |
53 | char _license[] SEC("license" ) = "GPL" ; |
54 | |