1 // SPDX-License-Identifier: GPL-2.0
2 #include <test_progs.h>
3 #include <network_helpers.h>
4
serial_test_flow_dissector_load_bytes(void)5 void serial_test_flow_dissector_load_bytes(void)
6 {
7 struct bpf_flow_keys flow_keys;
8 struct bpf_insn prog[] = {
9 // BPF_REG_1 - 1st argument: context
10 // BPF_REG_2 - 2nd argument: offset, start at first byte
11 BPF_MOV64_IMM(BPF_REG_2, 0),
12 // BPF_REG_3 - 3rd argument: destination, reserve byte on stack
13 BPF_ALU64_REG(BPF_MOV, BPF_REG_3, BPF_REG_10),
14 BPF_ALU64_IMM(BPF_ADD, BPF_REG_3, -1),
15 // BPF_REG_4 - 4th argument: copy one byte
16 BPF_MOV64_IMM(BPF_REG_4, 1),
17 // bpf_skb_load_bytes(ctx, sizeof(pkt_v4), ptr, 1)
18 BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
19 BPF_FUNC_skb_load_bytes),
20 BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 2),
21 // if (ret == 0) return BPF_DROP (2)
22 BPF_MOV64_IMM(BPF_REG_0, BPF_DROP),
23 BPF_EXIT_INSN(),
24 // if (ret != 0) return BPF_OK (0)
25 BPF_MOV64_IMM(BPF_REG_0, BPF_OK),
26 BPF_EXIT_INSN(),
27 };
28 int fd, err;
29 LIBBPF_OPTS(bpf_test_run_opts, topts,
30 .data_in = &pkt_v4,
31 .data_size_in = sizeof(pkt_v4),
32 .data_out = &flow_keys,
33 .data_size_out = sizeof(flow_keys),
34 .repeat = 1,
35 );
36
37 /* make sure bpf_skb_load_bytes is not allowed from skb-less context
38 */
39 fd = bpf_test_load_program(BPF_PROG_TYPE_FLOW_DISSECTOR, prog,
40 ARRAY_SIZE(prog), "GPL", 0, NULL, 0);
41 ASSERT_GE(fd, 0, "bpf_test_load_program good fd");
42
43 err = bpf_prog_test_run_opts(fd, &topts);
44 ASSERT_OK(err, "test_run");
45 ASSERT_EQ(topts.data_size_out, sizeof(flow_keys),
46 "test_run data_size_out");
47 ASSERT_EQ(topts.retval, BPF_OK, "test_run retval");
48
49 if (fd >= -1)
50 close(fd);
51 }
52