1 // SPDX-License-Identifier: GPL-2.0 2 #include <test_progs.h> 3 #include <network_helpers.h> 4 5 void serial_test_flow_dissector_load_bytes(void) 6 { 7 struct bpf_flow_keys flow_keys; 8 __u32 duration = 0, retval, size; 9 struct bpf_insn prog[] = { 10 // BPF_REG_1 - 1st argument: context 11 // BPF_REG_2 - 2nd argument: offset, start at first byte 12 BPF_MOV64_IMM(BPF_REG_2, 0), 13 // BPF_REG_3 - 3rd argument: destination, reserve byte on stack 14 BPF_ALU64_REG(BPF_MOV, BPF_REG_3, BPF_REG_10), 15 BPF_ALU64_IMM(BPF_ADD, BPF_REG_3, -1), 16 // BPF_REG_4 - 4th argument: copy one byte 17 BPF_MOV64_IMM(BPF_REG_4, 1), 18 // bpf_skb_load_bytes(ctx, sizeof(pkt_v4), ptr, 1) 19 BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, 20 BPF_FUNC_skb_load_bytes), 21 BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 2), 22 // if (ret == 0) return BPF_DROP (2) 23 BPF_MOV64_IMM(BPF_REG_0, BPF_DROP), 24 BPF_EXIT_INSN(), 25 // if (ret != 0) return BPF_OK (0) 26 BPF_MOV64_IMM(BPF_REG_0, BPF_OK), 27 BPF_EXIT_INSN(), 28 }; 29 int fd, err; 30 31 /* make sure bpf_skb_load_bytes is not allowed from skb-less context 32 */ 33 fd = bpf_load_program(BPF_PROG_TYPE_FLOW_DISSECTOR, prog, 34 ARRAY_SIZE(prog), "GPL", 0, NULL, 0); 35 CHECK(fd < 0, 36 "flow_dissector-bpf_skb_load_bytes-load", 37 "fd %d errno %d\n", 38 fd, errno); 39 40 err = bpf_prog_test_run(fd, 1, &pkt_v4, sizeof(pkt_v4), 41 &flow_keys, &size, &retval, &duration); 42 CHECK(size != sizeof(flow_keys) || err || retval != 1, 43 "flow_dissector-bpf_skb_load_bytes", 44 "err %d errno %d retval %d duration %d size %u/%zu\n", 45 err, errno, retval, duration, size, sizeof(flow_keys)); 46 47 if (fd >= -1) 48 close(fd); 49 } 50