selftests/hid: add tests for hid_bpf_input_report

Usual way of testing, we call the function and ensures we receive
the event

Link: https://lore.kernel.org/r/20240315-b4-hid-bpf-new-funcs-v4-6-079c282469d3@kernel.orgSigned-off-by: Benjamin Tissoires <bentiss@kernel.org>

tools/testing/selftests/hid/hid_bpf.c

@@ -749,6 +749,52 @@ TEST_F(hid_bpf, test_hid_change_report)
 	ASSERT_EQ(buf[2], 0) TH_LOG("leftovers_from_previous_test");
 }
 
+/*
+ * Call hid_bpf_input_report against the given uhid device,
+ * check that the program is called and does the expected.
+ */
+TEST_F(hid_bpf, test_hid_user_input_report_call)
+{
+	struct hid_hw_request_syscall_args args = {
+		.retval = -1,
+		.size = 10,
+	};
+	DECLARE_LIBBPF_OPTS(bpf_test_run_opts, tattrs,
+			    .ctx_in = &args,
+			    .ctx_size_in = sizeof(args),
+	);
+	__u8 buf[10] = {0};
+	int err, prog_fd;
+
+	LOAD_BPF;
+
+	args.hid = self->hid_id;
+	args.data[0] = 1; /* report ID */
+	args.data[1] = 2; /* report ID */
+	args.data[2] = 42; /* report ID */
+
+	prog_fd = bpf_program__fd(self->skel->progs.hid_user_input_report);
+
+	/* check that there is no data to read from hidraw */
+	memset(buf, 0, sizeof(buf));
+	err = read(self->hidraw_fd, buf, sizeof(buf));
+	ASSERT_EQ(err, -1) TH_LOG("read_hidraw");
+
+	err = bpf_prog_test_run_opts(prog_fd, &tattrs);
+
+	ASSERT_OK(err) TH_LOG("error while calling bpf_prog_test_run_opts");
+
+	ASSERT_EQ(args.retval, 0);
+
+	/* read the data from hidraw */
+	memset(buf, 0, sizeof(buf));
+	err = read(self->hidraw_fd, buf, sizeof(buf));
+	ASSERT_EQ(err, 6) TH_LOG("read_hidraw");
+	ASSERT_EQ(buf[0], 1);
+	ASSERT_EQ(buf[1], 2);
+	ASSERT_EQ(buf[2], 42);
+}
+
 /*
  * Call hid_bpf_hw_output_report against the given uhid device,
  * check that the program is called and does the expected.
@@ -797,8 +843,7 @@ TEST_F(hid_bpf, test_hid_user_output_report_call)
 }
 
 /*
- * Attach hid_user_raw_request to the given uhid device,
- * call the bpf program from userspace
+ * Call hid_hw_raw_request against the given uhid device,
  * check that the program is called and does the expected.
  */
 TEST_F(hid_bpf, test_hid_user_raw_request_call)

tools/testing/selftests/hid/progs/hid.c

@@ -125,6 +125,28 @@ int hid_user_output_report(struct hid_hw_request_syscall_args *args)
 	return 0;
 }
 
+SEC("syscall")
+int hid_user_input_report(struct hid_hw_request_syscall_args *args)
+{
+	struct hid_bpf_ctx *ctx;
+	const size_t size = args->size;
+	int i, ret = 0;
+
+	if (size > sizeof(args->data))
+		return -7; /* -E2BIG */
+
+	ctx = hid_bpf_allocate_context(args->hid);
+	if (!ctx)
+		return -1; /* EPERM check */
+
+	ret = hid_bpf_input_report(ctx, HID_INPUT_REPORT, args->data, size);
+	args->retval = ret;
+
+	hid_bpf_release_context(ctx);
+
+	return 0;
+}
+
 static const __u8 rdesc[] = {
 	0x05, 0x01,				/* USAGE_PAGE (Generic Desktop) */
 	0x09, 0x32,				/* USAGE (Z) */

tools/testing/selftests/hid/progs/hid_bpf_helpers.h

@@ -96,5 +96,9 @@ extern int hid_bpf_hw_request(struct hid_bpf_ctx *ctx,
 			      enum hid_class_request reqtype) __ksym;
 extern int hid_bpf_hw_output_report(struct hid_bpf_ctx *ctx,
 				    __u8 *buf, size_t buf__sz) __ksym;
+extern int hid_bpf_input_report(struct hid_bpf_ctx *ctx,
+				enum hid_report_type type,
+				__u8 *data,
+				size_t buf__sz) __ksym;
 
 #endif /* __HID_BPF_HELPERS_H */