From 786047dd08de3334722af036e2827ce3b34205cc Mon Sep 17 00:00:00 2001 From: Andrey Ignatov Date: Fri, 8 Mar 2019 15:22:03 -0800 Subject: selftests/bpf: Test bpf_sysctl_{get,set}_new_value helpers Test that new value provided by user space on sysctl write can be read by bpf_sysctl_get_new_value and overridden by bpf_sysctl_set_new_value. # ./test_sysctl ... Test case: sysctl_get_new_value sysctl:read EINVAL .. [PASS] Test case: sysctl_get_new_value sysctl:write ok .. [PASS] Test case: sysctl_get_new_value sysctl:write ok long .. [PASS] Test case: sysctl_get_new_value sysctl:write E2BIG .. [PASS] Test case: sysctl_set_new_value sysctl:read EINVAL .. [PASS] Test case: sysctl_set_new_value sysctl:write ok .. [PASS] Summary: 22 PASSED, 0 FAILED Signed-off-by: Andrey Ignatov Signed-off-by: Alexei Starovoitov --- tools/testing/selftests/bpf/test_sysctl.c | 222 ++++++++++++++++++++++++++++++ 1 file changed, 222 insertions(+) (limited to 'tools/testing/selftests/bpf/test_sysctl.c') diff --git a/tools/testing/selftests/bpf/test_sysctl.c b/tools/testing/selftests/bpf/test_sysctl.c index 9fb6560fa775..95437b72404f 100644 --- a/tools/testing/selftests/bpf/test_sysctl.c +++ b/tools/testing/selftests/bpf/test_sysctl.c @@ -536,6 +536,228 @@ static struct sysctl_test tests[] = { .newval = "600", /* same as default, should fail anyway */ .result = OP_EPERM, }, + { + .descr = "sysctl_get_new_value sysctl:read EINVAL", + .insns = { + /* sysctl_get_new_value arg2 (buf) */ + BPF_MOV64_REG(BPF_REG_7, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, -8), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_STX_MEM(BPF_DW, BPF_REG_7, BPF_REG_0, 0), + + BPF_MOV64_REG(BPF_REG_2, BPF_REG_7), + + /* sysctl_get_new_value arg3 (buf_len) */ + BPF_MOV64_IMM(BPF_REG_3, 8), + + /* sysctl_get_new_value(ctx, buf, buf_len) */ + BPF_EMIT_CALL(BPF_FUNC_sysctl_get_new_value), + + /* if (ret == expected) */ + BPF_JMP_IMM(BPF_JNE, BPF_REG_0, -EINVAL, 2), + + /* return ALLOW; */ + BPF_MOV64_IMM(BPF_REG_0, 1), + BPF_JMP_A(1), + + /* else return DENY; */ + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .attach_type = BPF_CGROUP_SYSCTL, + .sysctl = "net/ipv4/tcp_mem", + .open_flags = O_RDONLY, + .result = SUCCESS, + }, + { + .descr = "sysctl_get_new_value sysctl:write ok", + .insns = { + /* sysctl_get_new_value arg2 (buf) */ + BPF_MOV64_REG(BPF_REG_7, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, -8), + + BPF_MOV64_REG(BPF_REG_2, BPF_REG_7), + + /* sysctl_get_new_value arg3 (buf_len) */ + BPF_MOV64_IMM(BPF_REG_3, 4), + + /* sysctl_get_new_value(ctx, buf, buf_len) */ + BPF_EMIT_CALL(BPF_FUNC_sysctl_get_new_value), + + /* if (ret == expected && */ + BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 3, 4), + + /* buf[0:4] == "606\0") */ + BPF_LDX_MEM(BPF_W, BPF_REG_9, BPF_REG_7, 0), + BPF_JMP_IMM(BPF_JNE, BPF_REG_9, 0x00363036, 2), + + /* return DENY; */ + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_JMP_A(1), + + /* else return ALLOW; */ + BPF_MOV64_IMM(BPF_REG_0, 1), + BPF_EXIT_INSN(), + }, + .attach_type = BPF_CGROUP_SYSCTL, + .sysctl = "net/ipv4/route/mtu_expires", + .open_flags = O_WRONLY, + .newval = "606", + .result = OP_EPERM, + }, + { + .descr = "sysctl_get_new_value sysctl:write ok long", + .insns = { + /* sysctl_get_new_value arg2 (buf) */ + BPF_MOV64_REG(BPF_REG_7, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, -24), + + BPF_MOV64_REG(BPF_REG_2, BPF_REG_7), + + /* sysctl_get_new_value arg3 (buf_len) */ + BPF_MOV64_IMM(BPF_REG_3, 24), + + /* sysctl_get_new_value(ctx, buf, buf_len) */ + BPF_EMIT_CALL(BPF_FUNC_sysctl_get_new_value), + + /* if (ret == expected && */ + BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 23, 14), + + /* buf[0:8] == "3000000 " && */ + BPF_LD_IMM64(BPF_REG_8, 0x2030303030303033ULL), + BPF_LDX_MEM(BPF_DW, BPF_REG_9, BPF_REG_7, 0), + BPF_JMP_REG(BPF_JNE, BPF_REG_8, BPF_REG_9, 10), + + /* buf[8:16] == "4000000 " && */ + BPF_LD_IMM64(BPF_REG_8, 0x2030303030303034ULL), + BPF_LDX_MEM(BPF_DW, BPF_REG_9, BPF_REG_7, 8), + BPF_JMP_REG(BPF_JNE, BPF_REG_8, BPF_REG_9, 6), + + /* buf[16:24] == "6000000\0") */ + BPF_LD_IMM64(BPF_REG_8, 0x0030303030303036ULL), + BPF_LDX_MEM(BPF_DW, BPF_REG_9, BPF_REG_7, 16), + BPF_JMP_REG(BPF_JNE, BPF_REG_8, BPF_REG_9, 2), + + /* return DENY; */ + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_JMP_A(1), + + /* else return ALLOW; */ + BPF_MOV64_IMM(BPF_REG_0, 1), + BPF_EXIT_INSN(), + }, + .attach_type = BPF_CGROUP_SYSCTL, + .sysctl = "net/ipv4/tcp_mem", + .open_flags = O_WRONLY, + .newval = "3000000 4000000 6000000", + .result = OP_EPERM, + }, + { + .descr = "sysctl_get_new_value sysctl:write E2BIG", + .insns = { + /* sysctl_get_new_value arg2 (buf) */ + BPF_MOV64_REG(BPF_REG_7, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, -8), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_STX_MEM(BPF_B, BPF_REG_7, BPF_REG_0, 3), + + BPF_MOV64_REG(BPF_REG_2, BPF_REG_7), + + /* sysctl_get_new_value arg3 (buf_len) */ + BPF_MOV64_IMM(BPF_REG_3, 3), + + /* sysctl_get_new_value(ctx, buf, buf_len) */ + BPF_EMIT_CALL(BPF_FUNC_sysctl_get_new_value), + + /* if (ret == expected && */ + BPF_JMP_IMM(BPF_JNE, BPF_REG_0, -E2BIG, 4), + + /* buf[0:3] == "60\0") */ + BPF_LDX_MEM(BPF_W, BPF_REG_9, BPF_REG_7, 0), + BPF_JMP_IMM(BPF_JNE, BPF_REG_9, 0x003036, 2), + + /* return DENY; */ + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_JMP_A(1), + + /* else return ALLOW; */ + BPF_MOV64_IMM(BPF_REG_0, 1), + BPF_EXIT_INSN(), + }, + .attach_type = BPF_CGROUP_SYSCTL, + .sysctl = "net/ipv4/route/mtu_expires", + .open_flags = O_WRONLY, + .newval = "606", + .result = OP_EPERM, + }, + { + .descr = "sysctl_set_new_value sysctl:read EINVAL", + .insns = { + /* sysctl_set_new_value arg2 (buf) */ + BPF_MOV64_REG(BPF_REG_7, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, -8), + BPF_MOV64_IMM(BPF_REG_0, 0x00303036), + BPF_STX_MEM(BPF_DW, BPF_REG_7, BPF_REG_0, 0), + + BPF_MOV64_REG(BPF_REG_2, BPF_REG_7), + + /* sysctl_set_new_value arg3 (buf_len) */ + BPF_MOV64_IMM(BPF_REG_3, 3), + + /* sysctl_set_new_value(ctx, buf, buf_len) */ + BPF_EMIT_CALL(BPF_FUNC_sysctl_set_new_value), + + /* if (ret == expected) */ + BPF_JMP_IMM(BPF_JNE, BPF_REG_0, -EINVAL, 2), + + /* return ALLOW; */ + BPF_MOV64_IMM(BPF_REG_0, 1), + BPF_JMP_A(1), + + /* else return DENY; */ + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .attach_type = BPF_CGROUP_SYSCTL, + .sysctl = "net/ipv4/route/mtu_expires", + .open_flags = O_RDONLY, + .result = SUCCESS, + }, + { + .descr = "sysctl_set_new_value sysctl:write ok", + .fixup_value_insn = 2, + .insns = { + /* sysctl_set_new_value arg2 (buf) */ + BPF_MOV64_REG(BPF_REG_7, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, -8), + BPF_MOV64_IMM(BPF_REG_0, FIXUP_SYSCTL_VALUE), + BPF_STX_MEM(BPF_DW, BPF_REG_7, BPF_REG_0, 0), + + BPF_MOV64_REG(BPF_REG_2, BPF_REG_7), + + /* sysctl_set_new_value arg3 (buf_len) */ + BPF_MOV64_IMM(BPF_REG_3, 3), + + /* sysctl_set_new_value(ctx, buf, buf_len) */ + BPF_EMIT_CALL(BPF_FUNC_sysctl_set_new_value), + + /* if (ret == expected) */ + BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 2), + + /* return ALLOW; */ + BPF_MOV64_IMM(BPF_REG_0, 1), + BPF_JMP_A(1), + + /* else return DENY; */ + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .attach_type = BPF_CGROUP_SYSCTL, + .sysctl = "net/ipv4/route/mtu_expires", + .open_flags = O_WRONLY, + .newval = "606", + .result = SUCCESS, + }, }; static size_t probe_prog_length(const struct bpf_insn *fp) -- cgit v1.2.3-59-g8ed1b