Commit e8445737 authored by Benjamin Tissoires's avatar Benjamin Tissoires Committed by Jiri Kosina
Browse files

selftests/hid: add report descriptor fixup tests 



Simple report descriptor override in HID: replace part of the report
descriptor from a static definition in the bpf kernel program.

Note that this test should be run last because we disconnect/reconnect
the device, meaning that it changes the overall uhid device.

Signed-off-by: default avatarBenjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: default avatarJiri Kosina <jkosina@suse.cz>
parent ad190df1

tools/testing/selftests/hid/hid_bpf.c

+32 −0
Original line number Diff line number Diff line
@@ -740,6 +740,38 @@ TEST_F(hid_bpf, test_hid_user_raw_request_call) 
	ASSERT_EQ(args.data[1], 2);

}



/*

 * Attach hid_rdesc_fixup to the given uhid device,

 * retrieve and open the matching hidraw node,

 * check that the hidraw report descriptor has been updated.

 */

TEST_F(hid_bpf, test_rdesc_fixup)

{

	struct hidraw_report_descriptor rpt_desc = {0};

	const struct test_program progs[] = {

		{ .name = "hid_rdesc_fixup" },

	};

	int err, desc_size;



	LOAD_PROGRAMS(progs);



	/* check that hid_rdesc_fixup() was executed */

	ASSERT_EQ(self->skel->data->callback2_check, 0x21);



	/* read the exposed report descriptor from hidraw */

	err = ioctl(self->hidraw_fd, HIDIOCGRDESCSIZE, &desc_size);

	ASSERT_GE(err, 0) TH_LOG("error while reading HIDIOCGRDESCSIZE: %d", err);



	/* ensure the new size of the rdesc is bigger than the old one */

	ASSERT_GT(desc_size, sizeof(rdesc));



	rpt_desc.size = desc_size;

	err = ioctl(self->hidraw_fd, HIDIOCGRDESC, &rpt_desc);

	ASSERT_GE(err, 0) TH_LOG("error while reading HIDIOCGRDESC: %d", err);



	ASSERT_EQ(rpt_desc.value[4], 0x42);

}



static int libbpf_print_fn(enum libbpf_print_level level,

			   const char *format, va_list args)

{

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

+53 −0
Original line number Diff line number Diff line
@@ -88,3 +88,56 @@ int hid_user_raw_request(struct hid_hw_request_syscall_args *args) 


	return 0;

}



static const __u8 rdesc[] = {

	0x05, 0x01,				/* USAGE_PAGE (Generic Desktop) */

	0x09, 0x32,				/* USAGE (Z) */

	0x95, 0x01,				/* REPORT_COUNT (1) */

	0x81, 0x06,				/* INPUT (Data,Var,Rel) */



	0x06, 0x00, 0xff,			/* Usage Page (Vendor Defined Page 1) */

	0x19, 0x01,				/* USAGE_MINIMUM (1) */

	0x29, 0x03,				/* USAGE_MAXIMUM (3) */

	0x15, 0x00,				/* LOGICAL_MINIMUM (0) */

	0x25, 0x01,				/* LOGICAL_MAXIMUM (1) */

	0x95, 0x03,				/* REPORT_COUNT (3) */

	0x75, 0x01,				/* REPORT_SIZE (1) */

	0x91, 0x02,				/* Output (Data,Var,Abs) */

	0x95, 0x01,				/* REPORT_COUNT (1) */

	0x75, 0x05,				/* REPORT_SIZE (5) */

	0x91, 0x01,				/* Output (Cnst,Var,Abs) */



	0x06, 0x00, 0xff,			/* Usage Page (Vendor Defined Page 1) */

	0x19, 0x06,				/* USAGE_MINIMUM (6) */

	0x29, 0x08,				/* USAGE_MAXIMUM (8) */

	0x15, 0x00,				/* LOGICAL_MINIMUM (0) */

	0x25, 0x01,				/* LOGICAL_MAXIMUM (1) */

	0x95, 0x03,				/* REPORT_COUNT (3) */

	0x75, 0x01,				/* REPORT_SIZE (1) */

	0xb1, 0x02,				/* Feature (Data,Var,Abs) */

	0x95, 0x01,				/* REPORT_COUNT (1) */

	0x75, 0x05,				/* REPORT_SIZE (5) */

	0x91, 0x01,				/* Output (Cnst,Var,Abs) */



	0xc0,				/* END_COLLECTION */

	0xc0,			/* END_COLLECTION */

};



SEC("?fmod_ret/hid_bpf_rdesc_fixup")

int BPF_PROG(hid_rdesc_fixup, struct hid_bpf_ctx *hid_ctx)

{

	__u8 *data = hid_bpf_get_data(hid_ctx, 0 /* offset */, 4096 /* size */);



	if (!data)

		return 0; /* EPERM check */



	callback2_check = data[4];



	/* insert rdesc at offset 73 */

	__builtin_memcpy(&data[73], rdesc, sizeof(rdesc));



	/* Change Usage Vendor globally */

	data[4] = 0x42;



	return sizeof(rdesc) + 73;

}