[Q] IOKit: Inside the bowels of IOHIDSystem

[Emmanuel Dreyfus]

Hi everyone

I try to understand the kernel/userland interface of the IOHIDSystem
driver in MacOS X. I wrote the following test code, strongly inspired
from XDarwin sources. But whatever happens, I never get any event for
moved mouse in the low level queue.

Anyone has an idea why?

#include <mach/mach_types.h>
#include <mach/mach_host.h>
#include <mach/mach_traps.h>
#include <mach/mach_init.h>

#include <IOKitLib.h>
#include <IOLLEvent.h>
#include <IOHIDShared.h>

#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <ctype.h>

void dump(char *, size_t);

/*
* cc -Wall -Werror -ansi \
* -I/System/Library/Frameworks/IOKit.framework/Headers \
* -I/System/Library/Frameworks/IOKit.framework/Headers/hidsystem \
* -L/System/Library/Frameworks/IOKit.framework -g
* -o test -lIOKit test.c
*/
int
main(argc, argv)
int argc;
char **argv;
{
host_name_port_t hs;
io_master_t iop;
kern_return_t ret;
mach_port_t rp;
CFMutableDictionaryRef classToMatch;
char *cn = "IOHIDSystem";
io_iterator_t iterator;
io_object_t serviceObject;
io_connect_t dataport;
vm_address_t shmem;
vm_size_t size;
EvGlobals *evg;
int i;
int log;

if (argc != 2) {
printf("usage: %s logfile\n", argv[0]);
return 1;
}

log = open(argv[1], O_WRONLY|O_TRUNC|O_CREAT, 0644);
if (log == -1) {
perror("cannot open log file");
return 1;
}

rp = mach_reply_port();
hs = mach_host_self();

ret = IOMasterPort(MACH_PORT_NULL, &iop);
printf("ret = 0x%x, rp = 0x%x, hs = 0x%x, iop = 0x%x\n",
ret, rp, hs, iop);
if (ret != 0)
return 1;

classToMatch = IOServiceMatching(cn);

ret = IOServiceGetMatchingServices(iop,
classToMatch, &iterator);
printf("ret = 0x%x, iterator = 0x%x\n", ret, iterator);
if (ret != 0)
return 1;

serviceObject = IOIteratorNext(iterator);
printf("serviceObject = 0x%x\n", serviceObject);

ret = IOServiceOpen(serviceObject, mach_task_self(),
0, &dataport);
printf("ret = 0x%x, dataport = 0x%x\n", ret, dataport);
if (ret != 0)
return 1;

ret = IOHIDCreateSharedMemory(dataport,
kIOHIDCurrentShmemVersion);
printf("ret = 0x%x\n", ret);
if (ret != 0)
return 1;

ret = IOConnectMapMemory(dataport, kIOHIDGlobalMemory,
mach_task_self(), &shmem, &size, kIOMapAnywhere);
printf("ret = 0x%x, shmem = 0x%x, size = 0x%x\n",
ret, shmem, size);
if (ret != 0)
return 1;

evg = (EvGlobals *)(shmem +
((EvOffsets *)shmem)->evGlobalsOffset);
printf("evg = %p\n", evg);
if (evg == NULL)
return 1;

evg->movedMask = NX_MOUSEMOVEDMASK;

printf("Perform an action within 3 seconds... \n");
sleep(3);
printf("Okay, let's dump in the logfile...\n");

(void)close(1);
(void)dup(log);

printf("LLEHead = %d\n", evg->LLEHead);
printf("LLETail = %d\n", evg->LLETail);
printf("LLELast = %d\n", evg->LLELast);
for (i = 0; i < LLEQSIZE; i++) {
printf("item %d\n", i);
printf(" next = %d, type = %d, flags = %d\n",
evg->lleq[i].next,
evg->lleq[i].event.type,
evg->lleq[i].event.flags);
printf(" x = %d, y = %d, window = %d\n",
evg->lleq[i].event.location.x,
evg->lleq[i].event.location.y,
evg->lleq[i].event.window);
dump((char *)&evg->lleq[i].event.data,
sizeof(evg->lleq[i].event.data));
}
printf("\n\nFull dump of the shared memory\n");
dump((char *)shmem, size);

return 0;
}

void
dump(data, len)
char *data;
size_t len;
{
int i, j;

for (i = 0; i < len; i += 16) {
printf("%p ", &data[i]);
for (j = i; j < i + 16; j += 4)
printf("0x%08x ", *((int *)(&data[j])));
printf(" ");
for (j = i; j < i + 16; j++)
if (isprint(data[j]))
printf("%c", data[j]);
else
printf(".");
printf("\n");
}
return;
}


--
Emmanuel Dreyfus
[email]manu@netbsd.org[/email]

[Eric Albert]

In article <1g1dh7y.8ihsl21v0grpmN%manu@netbsd.org>,
[email]manu@netbsd.org[/email] (Emmanuel Dreyfus) wrote:

> I try to understand the kernel/userland interface of the IOHIDSystem
> driver in MacOS X. I wrote the following test code, strongly inspired
> from XDarwin sources. But whatever happens, I never get any event for
> moved mouse in the low level queue.
>
> Anyone has an idea why?

Probably not here. I'd suggest asking this on Apple's
darwin-development mailing list.

-Eric

--
Eric Albert [email]ejalbert@stanford.edu[/email]
[url]http://rescomp.stanford.edu/~ejalbert/[/url]

[Emmanuel Dreyfus]

Eric Albert <ejalbert@stanford.edu> wrote:

> Probably not here. I'd suggest asking this on Apple's
> darwin-development mailing list.

Thanks for the hint.
Anyway, someone else gave me the answer behinf the scene: IOHIDSystem
will not report events until this is called:

IOHIDSetEventsEnable (dataport, TRUE);

--
Emmanuel Dreyfus
Publicité subliminale: achetez ce livre!
[url]http://www.eyrolles.com/php.informatique/Ouvrages/9782212112443.php3[/url]
[email]manu@netbsd.org[/email]