| // SPDX-License-Identifier: GPL-2.0 |
| #include <test_progs.h> |
| #include <network_helpers.h> |
| |
| void test_flow_dissector_load_bytes(void) |
| { |
| struct bpf_flow_keys flow_keys; |
| __u32 duration = 0, retval, size; |
| struct bpf_insn prog[] = { |
| // BPF_REG_1 - 1st argument: context |
| // BPF_REG_2 - 2nd argument: offset, start at first byte |
| BPF_MOV64_IMM(BPF_REG_2, 0), |
| // BPF_REG_3 - 3rd argument: destination, reserve byte on stack |
| BPF_ALU64_REG(BPF_MOV, BPF_REG_3, BPF_REG_10), |
| BPF_ALU64_IMM(BPF_ADD, BPF_REG_3, -1), |
| // BPF_REG_4 - 4th argument: copy one byte |
| BPF_MOV64_IMM(BPF_REG_4, 1), |
| // bpf_skb_load_bytes(ctx, sizeof(pkt_v4), ptr, 1) |
| BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, |
| BPF_FUNC_skb_load_bytes), |
| BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 2), |
| // if (ret == 0) return BPF_DROP (2) |
| BPF_MOV64_IMM(BPF_REG_0, BPF_DROP), |
| BPF_EXIT_INSN(), |
| // if (ret != 0) return BPF_OK (0) |
| BPF_MOV64_IMM(BPF_REG_0, BPF_OK), |
| BPF_EXIT_INSN(), |
| }; |
| int fd, err; |
| |
| /* make sure bpf_skb_load_bytes is not allowed from skb-less context |
| */ |
| fd = bpf_load_program(BPF_PROG_TYPE_FLOW_DISSECTOR, prog, |
| ARRAY_SIZE(prog), "GPL", 0, NULL, 0); |
| CHECK(fd < 0, |
| "flow_dissector-bpf_skb_load_bytes-load", |
| "fd %d errno %d\n", |
| fd, errno); |
| |
| err = bpf_prog_test_run(fd, 1, &pkt_v4, sizeof(pkt_v4), |
| &flow_keys, &size, &retval, &duration); |
| CHECK(size != sizeof(flow_keys) || err || retval != 1, |
| "flow_dissector-bpf_skb_load_bytes", |
| "err %d errno %d retval %d duration %d size %u/%zu\n", |
| err, errno, retval, duration, size, sizeof(flow_keys)); |
| |
| if (fd >= -1) |
| close(fd); |
| } |