[PATCH] selftests/input: Introduce basic tests for evdev ioctls

[eballetbo]

From: Enric Balletbo i Serra <eballetbo@xxxxxxxxxx>

This provides a basic infrastructure for the creation of tests for the evdev
interface. Most of this is code is adapted from the libevdev wrapper
library. While most of evdev ioctls are covered and tested using
libevdev tests there are some evdev ioctls that aren't because are not
supported (and will not be supported) by libevdev. So, adding, at least
those tests, would make sense.

The test creates an uinput device (and an evdev device) so you can
call the wanted ioctl from userspace. So, to run those tests you need
to have support for uinput and evdev as well.

Signed-off-by: Enric Balletbo i Serra <eballetbo@xxxxxxxxxx>
---
 tools/testing/selftests/Makefile           |   1 +
 tools/testing/selftests/input/.gitignore   |   2 +
 tools/testing/selftests/input/Makefile     |   5 +
 tools/testing/selftests/input/config       |   3 +
 tools/testing/selftests/input/evioc-test.c | 282 +++++++++++++++++++++
 5 files changed, 293 insertions(+)
 create mode 100644 tools/testing/selftests/input/.gitignore
 create mode 100644 tools/testing/selftests/input/Makefile
 create mode 100644 tools/testing/selftests/input/config
 create mode 100644 tools/testing/selftests/input/evioc-test.c

diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile
index 90a62cf75008..29fc77168aa7 100644
--- a/tools/testing/selftests/Makefile
+++ b/tools/testing/selftests/Makefile
@@ -28,6 +28,7 @@ TARGETS += futex
 TARGETS += gpio
 TARGETS += hid
 TARGETS += intel_pstate
+TARGETS += input
 TARGETS += iommu
 TARGETS += ipc
 TARGETS += ir
diff --git a/tools/testing/selftests/input/.gitignore b/tools/testing/selftests/input/.gitignore
new file mode 100644
index 000000000000..37f5dff3255b
--- /dev/null
+++ b/tools/testing/selftests/input/.gitignore
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0
+evioc-test
diff --git a/tools/testing/selftests/input/Makefile b/tools/testing/selftests/input/Makefile
new file mode 100644
index 000000000000..031729be0628
--- /dev/null
+++ b/tools/testing/selftests/input/Makefile
@@ -0,0 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0
+CFLAGS +=  -D_GNU_SOURCE -std=gnu99 -Wl,-no-as-needed -Wall $(KHDR_INCLUDES)
+
+TEST_GEN_PROGS := evioc-test
+include ../lib.mk
diff --git a/tools/testing/selftests/input/config b/tools/testing/selftests/input/config
new file mode 100644
index 000000000000..b7512f3e6d8d
--- /dev/null
+++ b/tools/testing/selftests/input/config
@@ -0,0 +1,3 @@
+CONFIG_INPUT=y
+CONFIG_INPUT_EVDEV=y
+CONFIG_INPUT_UINPUT=m
diff --git a/tools/testing/selftests/input/evioc-test.c b/tools/testing/selftests/input/evioc-test.c
new file mode 100644
index 000000000000..4c0c8ebed378
--- /dev/null
+++ b/tools/testing/selftests/input/evioc-test.c
@@ -0,0 +1,282 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2023 Red Hat, Inc.
+ *
+ * Part of the code in this file is inspired and copied from the libevdev wrapper library
+ * for evdev devices written by Peter Hutterer.
+ */
+
+#include <dirent.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <linux/uinput.h>
+#include <poll.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <time.h>
+#include <unistd.h>
+
+#include "../kselftest_harness.h"
+
+#define TEST_DEVICE_NAME "selftest input device"
+
+struct selftest_uinput {
+	int uinput_fd; /** file descriptor to uinput */
+	int evdev_fd; /** file descriptor to evdev */
+	char *name; /** device name */
+	char *syspath; /** /sys path */
+	char *devnode; /** device node */
+};
+
+static int is_event_device(const struct dirent *dent)
+{
+	return strncmp("event", dent->d_name, 5) == 0;
+}
+
+static char *fetch_device_node(const char *path)
+{
+	struct dirent **namelist;
+	char *devnode = NULL;
+	int ndev, i;
+
+	ndev = scandir(path, &namelist, is_event_device, alphasort);
+	if (ndev <= 0)
+		return NULL;
+
+	/* ndev should only ever be 1 */
+
+	for (i = 0; i < ndev; i++) {
+		if (!devnode && asprintf(&devnode, "/dev/input/%s",
+					 namelist[i]->d_name) == -1)
+			devnode = NULL;
+		free(namelist[i]);
+	}
+
+	free(namelist);
+
+	return devnode;
+}
+
+static int is_input_device(const struct dirent *dent)
+{
+	return strncmp("input", dent->d_name, 5) == 0;
+}
+
+/*
+ * Device node is guessed based on the sysfs path, the sysfs path contains a
+ * eventN file, that corresponds to our /dev/input/eventN number.
+ */
+static int fetch_syspath_and_devnode(struct selftest_uinput *uidev)
+{
+#define SYS_INPUT_DIR "/sys/devices/virtual/input/"
+	struct dirent **namelist;
+	int ndev, i;
+	int rc;
+	char buf[sizeof(SYS_INPUT_DIR) + 64] = SYS_INPUT_DIR;
+
+	rc = ioctl(uidev->uinput_fd,
+		   UI_GET_SYSNAME(sizeof(buf) - strlen(SYS_INPUT_DIR)),
+		   &buf[strlen(SYS_INPUT_DIR)]);
+	if (rc != -1) {
+		uidev->syspath = strdup(buf);
+		uidev->devnode = fetch_device_node(buf);
+		return 0;
+	}
+
+	ndev = scandir(SYS_INPUT_DIR, &namelist, is_input_device, alphasort);
+	if (ndev <= 0)
+		return -1;
+
+	for (i = 0; i < ndev; i++) {
+		int fd, len;
+
+		rc = snprintf(buf, sizeof(buf), "%s%s/name", SYS_INPUT_DIR,
+			      namelist[i]->d_name);
+		if (rc < 0 || (size_t)rc >= sizeof(buf))
+			continue;
+
+		/* created within time frame */
+		fd = open(buf, O_RDONLY);
+		if (fd < 0)
+			continue;
+
+		len = read(fd, buf, sizeof(buf));
+		close(fd);
+		if (len <= 0)
+			continue;
+
+		buf[len - 1] = '\0'; /* file contains \n */
+		if (strcmp(buf, uidev->name) == 0) {
+			if (uidev->syspath) {
+				fprintf(stderr,
+					"multiple identical devices found. syspath is unreliable\n");
+				break;
+			}
+
+			rc = snprintf(buf, sizeof(buf), "%s%s", SYS_INPUT_DIR,
+				      namelist[i]->d_name);
+
+			if (rc < 0 || (size_t)rc >= sizeof(buf)) {
+				fprintf(stderr,
+					"Invalid syspath, syspath is unreliable\n");
+				break;
+			}
+
+			uidev->syspath = strdup(buf);
+			uidev->devnode = fetch_device_node(buf);
+		}
+	}
+
+	for (i = 0; i < ndev; i++)
+		free(namelist[i]);
+	free(namelist);
+
+	return uidev->devnode ? 0 : -1;
+#undef SYS_INPUT_DIR
+}
+
+void selftest_uinput_destroy(struct selftest_uinput *uidev)
+{
+	if (!uidev)
+		return;
+
+	if (uidev->uinput_fd >= 0)
+		ioctl(uidev->uinput_fd, UI_DEV_DESTROY, NULL);
+
+	close(uidev->evdev_fd);
+	close(uidev->uinput_fd);
+
+	free(uidev->syspath);
+	free(uidev->devnode);
+	free(uidev->name);
+	free(uidev);
+}
+
+int selftest_uinput_create_device(struct selftest_uinput **uidev, ...)
+{
+	struct selftest_uinput *new_device;
+	struct uinput_setup setup;
+	va_list args;
+	int rc, fd;
+	int type;
+
+	new_device = calloc(1, sizeof(struct selftest_uinput));
+	if (!new_device)
+		return -ENOMEM;
+
+	memset(&setup, 0, sizeof(setup));
+	strncpy(setup.name, TEST_DEVICE_NAME, UINPUT_MAX_NAME_SIZE - 1);
+	setup.id.vendor = 0x1234; /* sample vendor */
+	setup.id.product = 0x5678; /* sample product */
+	setup.id.bustype = BUS_USB;
+
+	fd = open("/dev/uinput", O_WRONLY | O_NONBLOCK);
+	if (fd < 0) {
+		fprintf(stderr, "cannot open uinput (%d): %m\n", errno);
+		goto error;
+	}
+
+	va_start(args, uidev);
+	rc = 0;
+	do {
+		type = va_arg(args, int);
+		if (type == -1)
+			break;
+		rc = ioctl(fd, UI_SET_EVBIT, type);
+	} while (rc == 0);
+	va_end(args);
+
+	rc = ioctl(fd, UI_DEV_SETUP, &setup);
+	if (rc == -1)
+		goto error;
+
+	rc = ioctl(fd, UI_DEV_CREATE, NULL);
+	if (rc == -1)
+		goto error;
+
+	new_device->name = strdup(TEST_DEVICE_NAME);
+	new_device->uinput_fd = fd;
+
+	if (fetch_syspath_and_devnode(new_device) == -1) {
+		fprintf(stderr, "unable to fetch syspath or device node.\n");
+		errno = ENODEV;
+		goto error;
+	}
+
+	fd = open(new_device->devnode, O_RDONLY);
+	if (fd < 0) {
+		fprintf(stderr, "cannot open uinput (%d): %m\n", errno);
+		goto error;
+	}
+	new_device->evdev_fd = fd;
+
+	*uidev = new_device;
+
+	return 0;
+
+error:
+	rc = -errno;
+	selftest_uinput_destroy(new_device);
+	return rc;
+}
+
+const char *selftest_uinput_get_devnode(struct selftest_uinput *uidev)
+{
+	return uidev->devnode;
+}
+
+TEST(eviocgname_get_device_name)
+{
+	struct selftest_uinput *uidev;
+	char buf[256];
+	int rc;
+
+	rc = selftest_uinput_create_device(&uidev);
+	ASSERT_EQ(0, rc);
+	ASSERT_NE(NULL, uidev);
+
+	memset(buf, 0, sizeof(buf));
+	/* ioctl to get the name */
+	rc = ioctl(uidev->evdev_fd, EVIOCGNAME(sizeof(buf) - 1), buf);
+	ASSERT_GE(rc, 0);
+	ASSERT_STREQ(TEST_DEVICE_NAME, buf);
+
+	selftest_uinput_destroy(uidev);
+}
+
+TEST(eviocgrep_get_repeat_settings)
+{
+	struct selftest_uinput *uidev;
+	int rep_values[2];
+	int rc;
+
+	memset(rep_values, 0, sizeof(rep_values));
+
+	rc = selftest_uinput_create_device(&uidev);
+	ASSERT_EQ(0, rc);
+	ASSERT_NE(NULL, uidev);
+
+	/* ioctl to get the repeat rates values */
+	rc = ioctl(uidev->evdev_fd, EVIOCSREP, rep_values);
+	/* should fail because EV_REP is not set */
+	ASSERT_EQ(-1, rc);
+
+	selftest_uinput_destroy(uidev);
+
+	rc = selftest_uinput_create_device(&uidev, EV_REP);
+	ASSERT_EQ(0, rc);
+	ASSERT_NE(NULL, uidev);
+
+	/* ioctl to get the repeat rates values */
+	rc = ioctl(uidev->evdev_fd, EVIOCGREP, rep_values);
+	ASSERT_EQ(0, rc);
+	/* should get the default delay an period values set by the kernel */
+	ASSERT_EQ(rep_values[0], 250);
+	ASSERT_EQ(rep_values[1], 33);
+
+	selftest_uinput_destroy(uidev);
+}
+
+TEST_HARNESS_MAIN
-- 
2.40.1