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