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
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