+static void sock_fanout_set_ebpf(int fd)
+{
+ const int len_off = __builtin_offsetof(struct __sk_buff, len);
+ struct bpf_insn prog[] = {
+ { BPF_ALU64 | BPF_MOV | BPF_X, 6, 1, 0, 0 },
+ { BPF_LDX | BPF_W | BPF_MEM, 0, 6, len_off, 0 },
+ { BPF_JMP | BPF_JGE | BPF_K, 0, 0, 1, DATA_LEN },
+ { BPF_JMP | BPF_JA | BPF_K, 0, 0, 4, 0 },
+ { BPF_LD | BPF_B | BPF_ABS, 0, 0, 0, 0x50 },
+ { BPF_JMP | BPF_JEQ | BPF_K, 0, 0, 2, DATA_CHAR },
+ { BPF_JMP | BPF_JEQ | BPF_K, 0, 0, 1, DATA_CHAR_1 },
+ { BPF_ALU | BPF_MOV | BPF_K, 0, 0, 0, 0 },
+ { BPF_JMP | BPF_EXIT, 0, 0, 0, 0 }
+ };
+ char log_buf[512];
+ union bpf_attr attr;
+ int pfd;
+
+ memset(&attr, 0, sizeof(attr));
+ attr.prog_type = BPF_PROG_TYPE_SOCKET_FILTER;
+ attr.insns = (unsigned long) prog;
+ attr.insn_cnt = sizeof(prog) / sizeof(prog[0]);
+ attr.license = (unsigned long) "GPL";
+ attr.log_buf = (unsigned long) log_buf,
+ attr.log_size = sizeof(log_buf),
+ attr.log_level = 1,
+
+ pfd = syscall(__NR_bpf, BPF_PROG_LOAD, &attr, sizeof(attr));
+ if (pfd < 0) {
+ perror("bpf");
+ fprintf(stderr, "bpf verifier:\n%s\n", log_buf);
+ exit(1);
+ }
+
+ if (setsockopt(fd, SOL_PACKET, PACKET_FANOUT_DATA, &pfd, sizeof(pfd))) {
+ perror("fanout data ebpf");
+ exit(1);
+ }
+
+ if (close(pfd)) {
+ perror("close ebpf");
+ exit(1);
+ }
+}
+