@@ -1168,6 +1168,42 @@ TEST_F(hid_bpf, test_multiply_events_wq)
ASSERT_EQ(buf[1], 3);
}
+/*
+ * Attach hid_multiply_event to the given uhid device,
+ * retrieve and open the matching hidraw node,
+ * inject one event in the uhid device,
+ * check that the program sees it and can add extra data
+ */
+TEST_F(hid_bpf, test_multiply_events)
+{
+ const struct test_program progs[] = {
+ { .name = "hid_test_multiply_events" },
+ };
+ __u8 buf[10] = {0};
+ int err;
+
+ LOAD_PROGRAMS(progs);
+
+ /* inject one event */
+ buf[0] = 1;
+ buf[1] = 42;
+ uhid_send_event(_metadata, self->uhid_fd, buf, 6);
+
+ /* read the data from hidraw */
+ memset(buf, 0, sizeof(buf));
+ err = read(self->hidraw_fd, buf, sizeof(buf));
+ ASSERT_EQ(err, 9) TH_LOG("read_hidraw");
+ ASSERT_EQ(buf[0], 2);
+ ASSERT_EQ(buf[1], 47);
+
+ /* read the data from hidraw */
+ memset(buf, 0, sizeof(buf));
+ err = read(self->hidraw_fd, buf, sizeof(buf));
+ ASSERT_EQ(err, 9) TH_LOG("read_hidraw");
+ ASSERT_EQ(buf[0], 2);
+ ASSERT_EQ(buf[1], 52);
+}
+
/*
* Attach hid_insert{0,1,2} to the given uhid device,
* retrieve and open the matching hidraw node,
@@ -522,3 +522,42 @@ SEC(".struct_ops.link")
struct hid_bpf_ops test_multiply_events_wq = {
.hid_device_event = (void *)hid_test_multiply_events_wq,
};
+
+SEC("?struct_ops/hid_device_event")
+int BPF_PROG(hid_test_multiply_events, struct hid_bpf_ctx *hid_ctx, enum hid_report_type type)
+{
+ __u8 *data = hid_bpf_get_data(hid_ctx, 0 /* offset */, 9 /* size */);
+ __u8 buf[9];
+ int ret;
+
+ if (!data)
+ return 0; /* EPERM check */
+
+ if (data[0] != 1)
+ return 0;
+
+ /*
+ * we have to use an intermediate buffer as hid_bpf_input_report
+ * will memset data to \0
+ */
+ __builtin_memcpy(buf, data, sizeof(buf));
+
+ buf[0] = 2;
+ buf[1] += 5;
+ ret = hid_bpf_try_input_report(hid_ctx, HID_INPUT_REPORT, buf, sizeof(buf));
+ if (ret < 0)
+ return ret;
+
+ /*
+ * In real world we should reset the original buffer as data might be garbage now,
+ * but it actually now has the content of 'buf'
+ */
+ data[1] += 5;
+
+ return 9;
+}
+
+SEC(".struct_ops.link")
+struct hid_bpf_ops test_multiply_events = {
+ .hid_device_event = (void *)hid_test_multiply_events,
+};
@@ -89,6 +89,10 @@ extern int hid_bpf_input_report(struct hid_bpf_ctx *ctx,
enum hid_report_type type,
__u8 *data,
size_t buf__sz) __ksym;
+extern int hid_bpf_try_input_report(struct hid_bpf_ctx *ctx,
+ enum hid_report_type type,
+ __u8 *data,
+ size_t buf__sz) __ksym;
/* bpf_wq implementation */
extern int bpf_wq_init(struct bpf_wq *wq, void *p__map, unsigned int flags) __weak __ksym;
Similar to test_multiply_events_wq: we receive one event and inject a new one. But given that this time we are already in the event hook, we can use hid_bpf_try_input_report() directly as this function will not sleep. Note that the injected event gets processed before the original one this way. Signed-off-by: Benjamin Tissoires <bentiss@kernel.org> --- tools/testing/selftests/hid/hid_bpf.c | 36 ++++++++++++++++++++ tools/testing/selftests/hid/progs/hid.c | 39 ++++++++++++++++++++++ .../testing/selftests/hid/progs/hid_bpf_helpers.h | 4 +++ 3 files changed, 79 insertions(+)