flow_dissector_load_bytes.c (1592B)
1// SPDX-License-Identifier: GPL-2.0 2#include <test_progs.h> 3#include <network_helpers.h> 4 5void 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, 1, "test_run retval"); 48 49 if (fd >= -1) 50 close(fd); 51}