[PATCH libevdev 1/6] Add support for uinput device creation
David Herrmann
dh.herrmann at gmail.com
Wed Aug 14 06:05:33 PDT 2013
Hi
On Wed, Aug 14, 2013 at 2:45 PM, Benjamin Tissoires
<benjamin.tissoires at gmail.com> wrote:
> On Tue, Aug 13, 2013 at 12:39 PM, Peter Hutterer
> <peter.hutterer at who-t.net> wrote:
>> This lets libevdev provide a relatively generic interface for the
>> creation of uinput devices so we don't need to duplicate this across
>> multiple projects.
>>
>> Most of this is lifted from the current test implementation, with a
>> couple of minor changes.
>>
>> EV_REP needs special handling:
>> Kernel allows to set the EV_REP bit, it doesn't set REP_* bits (which we
>> wrap anyway) but it will also set the default values (500, 33).
>>
>> Signed-off-by: Peter Hutterer <peter.hutterer at who-t.net>
>> ---
>> doc/libevdev.doxygen.in | 3 +-
>> libevdev/Makefile.am | 5 +-
>> libevdev/libevdev-uinput-int.h | 29 +++++
>> libevdev/libevdev-uinput.c | 285 +++++++++++++++++++++++++++++++++++++++++
>> libevdev/libevdev-uinput.h | 232 +++++++++++++++++++++++++++++++++
>> libevdev/libevdev.c | 1 -
>> test/Makefile.am | 3 +
>> 7 files changed, 555 insertions(+), 3 deletions(-)
>> create mode 100644 libevdev/libevdev-uinput-int.h
>> create mode 100644 libevdev/libevdev-uinput.c
>> create mode 100644 libevdev/libevdev-uinput.h
>>
>> diff --git a/doc/libevdev.doxygen.in b/doc/libevdev.doxygen.in
>> index 4511ae8..855b317 100644
>> --- a/doc/libevdev.doxygen.in
>> +++ b/doc/libevdev.doxygen.in
>> @@ -668,7 +668,8 @@ WARN_LOGFILE =
>> # directories like "/usr/src/myproject". Separate the files or directories
>> # with spaces.
>>
>> -INPUT = @top_srcdir@/libevdev/libevdev.h
>> +INPUT = @top_srcdir@/libevdev/libevdev.h \
>> + @top_srcdir@/libevdev/libevdev-uinput.h
>>
>> # This tag can be used to specify the character encoding of the source files
>> # that doxygen parses. Internally doxygen uses the UTF-8 encoding, which is
>> diff --git a/libevdev/Makefile.am b/libevdev/Makefile.am
>> index 9879c0e..2e99c2a 100644
>> --- a/libevdev/Makefile.am
>> +++ b/libevdev/Makefile.am
>> @@ -6,12 +6,15 @@ libevdev_la_SOURCES = \
>> libevdev.h \
>> libevdev-int.h \
>> libevdev-util.h \
>> + libevdev-uinput.c \
>> + libevdev-uinput.h \
>> + libevdev-uinput-int.h \
>> libevdev.c
>>
>> libevdev_la_LDFLAGS = -version-info $(LIBEVDEV_LT_VERSION) -export-symbols-regex '^libevdev_' $(GCOV_LDFLAGS)
>>
>> libevdevincludedir = $(includedir)/libevdev-1.0/libevdev
>> -libevdevinclude_HEADERS = libevdev.h
>> +libevdevinclude_HEADERS = libevdev.h libevdev-uinput.h
>>
>> event-names.h: Makefile make-event-names.py
>> $(srcdir)/make-event-names.py --output=c > $@
>> diff --git a/libevdev/libevdev-uinput-int.h b/libevdev/libevdev-uinput-int.h
>> new file mode 100644
>> index 0000000..70fa1e1
>> --- /dev/null
>> +++ b/libevdev/libevdev-uinput-int.h
>> @@ -0,0 +1,29 @@
>> +/*
>> + * Copyright © 2013 Red Hat, Inc.
>> + *
>> + * Permission to use, copy, modify, distribute, and sell this software and its
>> + * documentation for any purpose is hereby granted without fee, provided that
>> + * the above copyright notice appear in all copies and that both that copyright
>> + * notice and this permission notice appear in supporting documentation, and
>> + * that the name of the copyright holders not be used in advertising or
>> + * publicity pertaining to distribution of the software without specific,
>> + * written prior permission. The copyright holders make no representations
>> + * about the suitability of this software for any purpose. It is provided "as
>> + * is" without express or implied warranty.
>> + *
>> + * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
>> + * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
>> + * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
>> + * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
>> + * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
>> + * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
>> + * OF THIS SOFTWARE.
>> + */
>> +
>> +
>> +struct libevdev_uinput {
>> + int fd; /**< file descriptor to uinput */
>> + char *name; /**< device name */
>> + char *syspath; /**< /sys path */
>> + time_t ctime[2]; /**< before/after UI_DEV_CREATE */
>> +};
>> diff --git a/libevdev/libevdev-uinput.c b/libevdev/libevdev-uinput.c
>> new file mode 100644
>> index 0000000..3009fba
>> --- /dev/null
>> +++ b/libevdev/libevdev-uinput.c
>> @@ -0,0 +1,285 @@
>> +/*
>> + * Copyright © 2013 Red Hat, Inc.
>> + *
>> + * Permission to use, copy, modify, distribute, and sell this software and its
>> + * documentation for any purpose is hereby granted without fee, provided that
>> + * the above copyright notice appear in all copies and that both that copyright
>> + * notice and this permission notice appear in supporting documentation, and
>> + * that the name of the copyright holders not be used in advertising or
>> + * publicity pertaining to distribution of the software without specific,
>> + * written prior permission. The copyright holders make no representations
>> + * about the suitability of this software for any purpose. It is provided "as
>> + * is" without express or implied warranty.
>> + *
>> + * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
>> + * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
>> + * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
>> + * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
>> + * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
>> + * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
>> + * OF THIS SOFTWARE.
>> + */
>> +
>> +#define _GNU_SOURCE
>> +#include <config.h>
>> +#include <fcntl.h>
>> +#include <poll.h>
>> +#include <errno.h>
>> +#include <unistd.h>
>> +#include <string.h>
>> +#include <stdio.h>
>> +#include <dirent.h>
>> +#include <sys/stat.h>
>> +#include <time.h>
>> +#include <linux/uinput.h>
>> +
>> +#include "libevdev.h"
>> +#include "libevdev-int.h"
>> +#include "libevdev-uinput.h"
>> +#include "libevdev-uinput-int.h"
>> +#include "libevdev-util.h"
>> +
>> +#define SYS_INPUT_DIR "/sys/devices/virtual/input/"
>> +
>> +static struct libevdev_uinput *
>> +alloc_uinput_device(const char *name)
>> +{
>> + struct libevdev_uinput *uinput_dev;
>> +
>> + uinput_dev = calloc(1, sizeof(struct libevdev_uinput));
>> + if (uinput_dev)
>> + uinput_dev->name = strdup(name);
>> +
>> + return uinput_dev;
>> +}
>> +
>> +int set_evbits(const struct libevdev *dev, int fd, struct uinput_user_dev *uidev)
>
> hmm, it looks like either this function should be prefixed with
> libevdev_uinput, or it should be static.
>
>> +{
>> + int rc = 0;
>> + unsigned int type;
>> +
>> + for (type = 0; type < EV_MAX; type++) {
>> + unsigned int code;
>> + int max;
>> + int uinput_bit;
>> + const unsigned long *mask;
>> +
>> + if (!libevdev_has_event_type(dev, type))
>> + continue;
>> +
>> + rc = ioctl(fd, UI_SET_EVBIT, type);
>> + if (rc == -1)
>> + break;
>> +
>> + /* uinput can't set EV_REP */
>> + if (type == EV_REP)
>> + continue;
>> +
>> + max = type_to_mask_const(dev, type, &mask);
>> + if (max == -1)
>> + continue;
>> +
>> + switch(type) {
>> + case EV_KEY: uinput_bit = UI_SET_KEYBIT; break;
>> + case EV_REL: uinput_bit = UI_SET_RELBIT; break;
>> + case EV_ABS: uinput_bit = UI_SET_ABSBIT; break;
>> + case EV_MSC: uinput_bit = UI_SET_MSCBIT; break;
>> + case EV_LED: uinput_bit = UI_SET_LEDBIT; break;
>> + case EV_SND: uinput_bit = UI_SET_SNDBIT; break;
>> + case EV_FF: uinput_bit = UI_SET_FFBIT; break;
>> + case EV_SW: uinput_bit = UI_SET_SWBIT; break;
>> + default:
>> + rc = -1;
>> + errno = EINVAL;
>> + goto out;
>> + }
>> +
>> + for (code = 0; code < max; code++) {
>> + if (!libevdev_has_event_code(dev, type, code))
>> + continue;
>> +
>> + rc = ioctl(fd, uinput_bit, code);
>> + if (rc == -1)
>> + goto out;
>> +
>> + if (type == EV_ABS) {
>> + const struct input_absinfo *abs = libevdev_get_abs_info(dev, code);
>> + uidev->absmin[code] = abs->minimum;
>> + uidev->absmax[code] = abs->maximum;
>> + uidev->absfuzz[code] = abs->fuzz;
>> + uidev->absflat[code] = abs->flat;
>> + /* uinput has no resolution in the device struct, this needs
>> + * to be fixed in the kernel */
>> + }
>> + }
>> +
>> + }
>> +
>> +out:
>> + return rc;
>> +}
>> +
>> +int set_props(const struct libevdev *dev, int fd, struct uinput_user_dev *uidev)
>
> ditto
>
>> +{
>> + unsigned int prop;
>> + int rc = 0;
>> +
>> + for (prop = 0; prop < INPUT_PROP_MAX; prop++) {
>> + if (!libevdev_has_property(dev, prop))
>> + continue;
>> +
>> + rc = ioctl(fd, UI_SET_PROPBIT, prop);
>> + if (rc == -1)
>> + break;
>> + }
>> + return rc;
>> +}
>> +
>> +int
>> +libevdev_uinput_create_from_device(const struct libevdev *dev, int fd, struct libevdev_uinput** uinput_dev)
>
> The code looks good, but I don't really like the parameter "fd". To
> me, it looks like this parameter can only be a fresh open of
> /dev/uinput node, with the right permissions and parameters. Besides,
> having this as a parameter, would allow a user to use it twice for two
> different uinput devices.
>
> To my mind, the parameter should be omitted and the open called in
> libevdev_uinput_create_from_device(). If the user wants to have a
> handle to it, it can call libevdev_uinput_get_fd(), and it will also
> allows us to close the fd in libevdev_uinput_destroy().
You might not have permissions to access /dev/uinput and get the fd
via a unix socket. That's quite common practice. But we could allow
"-1" and then open the fd inside of the constructor.
But I agree that libevdev should own the fd. uinput doesn't allow
multiplexing on a single fd so I cannot see any reason why a user
would want access to it after calling create_from_device().
Regards
David
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