Linux hidapi code dynamically loads udev

This commit is contained in:
Sam Lantinga 2019-11-23 12:11:20 -08:00
parent 359ae75bb2
commit 308e7f2fec
1 changed files with 48 additions and 36 deletions

View File

@ -48,7 +48,8 @@
#include <linux/hidraw.h> #include <linux/hidraw.h>
#include <linux/version.h> #include <linux/version.h>
#include <linux/input.h> #include <linux/input.h>
#include <libudev.h> //#include <libudev.h>
#include "../../core/linux/SDL_udev.h"
#include "hidapi.h" #include "hidapi.h"
@ -66,6 +67,8 @@ namespace NAMESPACE
#define HIDIOCGFEATURE(len) _IOC(_IOC_WRITE|_IOC_READ, 'H', 0x07, len) #define HIDIOCGFEATURE(len) _IOC(_IOC_WRITE|_IOC_READ, 'H', 0x07, len)
#endif #endif
static const SDL_UDEV_Symbols *udev_syms;
/* USB HID device property names */ /* USB HID device property names */
const char *device_string_names[] = { const char *device_string_names[] = {
"manufacturer", "manufacturer",
@ -147,7 +150,7 @@ static wchar_t *utf8_to_wchar_t(const char *utf8)
string. The returned string must be freed with free() when done.*/ string. The returned string must be freed with free() when done.*/
static wchar_t *copy_udev_string(struct udev_device *dev, const char *udev_name) static wchar_t *copy_udev_string(struct udev_device *dev, const char *udev_name)
{ {
return utf8_to_wchar_t(udev_device_get_sysattr_value(dev, udev_name)); return utf8_to_wchar_t(udev_syms->udev_device_get_sysattr_value(dev, udev_name));
} }
/* uses_numbered_reports() returns 1 if report_descriptor describes a device /* uses_numbered_reports() returns 1 if report_descriptor describes a device
@ -277,7 +280,7 @@ static int is_bluetooth(hid_device *dev)
int ret = -1; int ret = -1;
/* Create the udev object */ /* Create the udev object */
udev = udev_new(); udev = udev_syms->udev_new();
if (!udev) { if (!udev) {
printf("Can't create udev\n"); printf("Can't create udev\n");
return -1; return -1;
@ -286,14 +289,14 @@ static int is_bluetooth(hid_device *dev)
/* Get the dev_t (major/minor numbers) from the file handle. */ /* Get the dev_t (major/minor numbers) from the file handle. */
ret = fstat(dev->device_handle, &s); ret = fstat(dev->device_handle, &s);
if (-1 == ret) { if (-1 == ret) {
udev_unref(udev); udev_syms->udev_unref(udev);
return ret; return ret;
} }
/* Open a udev device from the dev_t. 'c' means character device. */ /* Open a udev device from the dev_t. 'c' means character device. */
udev_dev = udev_device_new_from_devnum(udev, 'c', s.st_rdev); udev_dev = udev_syms->udev_device_new_from_devnum(udev, 'c', s.st_rdev);
if (udev_dev) { if (udev_dev) {
hid_dev = udev_device_get_parent_with_subsystem_devtype( hid_dev = udev_syms->udev_device_get_parent_with_subsystem_devtype(
udev_dev, udev_dev,
"hid", "hid",
NULL); NULL);
@ -305,7 +308,7 @@ static int is_bluetooth(hid_device *dev)
char *product_name_utf8 = NULL; char *product_name_utf8 = NULL;
ret = parse_uevent_info( ret = parse_uevent_info(
udev_device_get_sysattr_value(hid_dev, "uevent"), udev_syms->udev_device_get_sysattr_value(hid_dev, "uevent"),
&bus_type, &bus_type,
&dev_vid, &dev_vid,
&dev_pid, &dev_pid,
@ -319,10 +322,10 @@ static int is_bluetooth(hid_device *dev)
/* hid_dev doesn't need to be (and can't be) unref'd. /* hid_dev doesn't need to be (and can't be) unref'd.
I'm not sure why, but it'll throw double-free() errors. */ I'm not sure why, but it'll throw double-free() errors. */
} }
udev_device_unref(udev_dev); udev_syms->udev_device_unref(udev_dev);
} }
udev_unref(udev); udev_syms->udev_unref(udev);
return ret; return ret;
} }
@ -339,7 +342,7 @@ static int get_device_string(hid_device *dev, enum device_string_id key, wchar_t
char *tmp; char *tmp;
/* Create the udev object */ /* Create the udev object */
udev = udev_new(); udev = udev_syms->udev_new();
if (!udev) { if (!udev) {
printf("Can't create udev\n"); printf("Can't create udev\n");
return -1; return -1;
@ -348,13 +351,13 @@ static int get_device_string(hid_device *dev, enum device_string_id key, wchar_t
/* Get the dev_t (major/minor numbers) from the file handle. */ /* Get the dev_t (major/minor numbers) from the file handle. */
ret = fstat(dev->device_handle, &s); ret = fstat(dev->device_handle, &s);
if (-1 == ret) { if (-1 == ret) {
udev_unref(udev); udev_syms->udev_unref(udev);
return ret; return ret;
} }
/* Open a udev device from the dev_t. 'c' means character device. */ /* Open a udev device from the dev_t. 'c' means character device. */
udev_dev = udev_device_new_from_devnum(udev, 'c', s.st_rdev); udev_dev = udev_syms->udev_device_new_from_devnum(udev, 'c', s.st_rdev);
if (udev_dev) { if (udev_dev) {
hid_dev = udev_device_get_parent_with_subsystem_devtype( hid_dev = udev_syms->udev_device_get_parent_with_subsystem_devtype(
udev_dev, udev_dev,
"hid", "hid",
NULL); NULL);
@ -365,7 +368,7 @@ static int get_device_string(hid_device *dev, enum device_string_id key, wchar_t
size_t retm; size_t retm;
ret = parse_uevent_info( ret = parse_uevent_info(
udev_device_get_sysattr_value(hid_dev, "uevent"), udev_syms->udev_device_get_sysattr_value(hid_dev, "uevent"),
&bus_type, &bus_type,
&dev_vid, &dev_vid,
&dev_pid, &dev_pid,
@ -401,7 +404,7 @@ static int get_device_string(hid_device *dev, enum device_string_id key, wchar_t
} }
else { else {
/* This is a USB device. Find its parent USB Device node. */ /* This is a USB device. Find its parent USB Device node. */
parent = udev_device_get_parent_with_subsystem_devtype( parent = udev_syms->udev_device_get_parent_with_subsystem_devtype(
udev_dev, udev_dev,
"usb", "usb",
"usb_device"); "usb_device");
@ -416,7 +419,7 @@ static int get_device_string(hid_device *dev, enum device_string_id key, wchar_t
goto end; goto end;
} }
str = udev_device_get_sysattr_value(parent, key_str); str = udev_syms->udev_device_get_sysattr_value(parent, key_str);
if (str) { if (str) {
/* Convert the string from UTF-8 to wchar_t */ /* Convert the string from UTF-8 to wchar_t */
retm = mbstowcs(string, str, maxlen); retm = mbstowcs(string, str, maxlen);
@ -432,10 +435,10 @@ end:
free(serial_number_utf8); free(serial_number_utf8);
free(product_name_utf8); free(product_name_utf8);
udev_device_unref(udev_dev); udev_syms->udev_device_unref(udev_dev);
/* parent and hid_dev don't need to be (and can't be) unref'd. /* parent and hid_dev don't need to be (and can't be) unref'd.
I'm not sure why, but they'll throw double-free() errors. */ I'm not sure why, but they'll throw double-free() errors. */
udev_unref(udev); udev_syms->udev_unref(udev);
return ret; return ret;
} }
@ -451,11 +454,17 @@ int HID_API_EXPORT hid_init(void)
kernel_version = detect_kernel_version(); kernel_version = detect_kernel_version();
udev_syms = SDL_UDEV_GetUdevSyms();
if (!udev_syms)
return -1;
return 0; return 0;
} }
int HID_API_EXPORT hid_exit(void) int HID_API_EXPORT hid_exit(void)
{ {
SDL_UDEV_ReleaseUdevSyms();
/* Nothing to do for this in the Linux/hidraw implementation. */ /* Nothing to do for this in the Linux/hidraw implementation. */
return 0; return 0;
} }
@ -474,20 +483,23 @@ struct hid_device_info HID_API_EXPORT *hid_enumerate(unsigned short vendor_id,
hid_init(); hid_init();
/* Create the udev object */ /* Create the udev object */
udev = udev_new(); udev = udev_syms->udev_new();
if (!udev) { if (!udev) {
printf("Can't create udev\n"); printf("Can't create udev\n");
return NULL; return NULL;
} }
/* Create a list of the devices in the 'hidraw' subsystem. */ /* Create a list of the devices in the 'hidraw' subsystem. */
enumerate = udev_enumerate_new(udev); enumerate = udev_syms->udev_enumerate_new(udev);
udev_enumerate_add_match_subsystem(enumerate, "hidraw"); udev_syms->udev_enumerate_add_match_subsystem(enumerate, "hidraw");
udev_enumerate_scan_devices(enumerate); udev_syms->udev_enumerate_scan_devices(enumerate);
devices = udev_enumerate_get_list_entry(enumerate); devices = udev_syms->udev_enumerate_get_list_entry(enumerate);
/* For each item, see if it matches the vid/pid, and if so /* For each item, see if it matches the vid/pid, and if so
create a udev_device record for it */ create a udev_device record for it */
udev_list_entry_foreach(dev_list_entry, devices) { for (dev_list_entry = devices;
dev_list_entry;
dev_list_entry = udev_syms->udev_list_entry_get_next(dev_list_entry)) {
const char *sysfs_path; const char *sysfs_path;
const char *dev_path; const char *dev_path;
const char *str; const char *str;
@ -504,11 +516,11 @@ struct hid_device_info HID_API_EXPORT *hid_enumerate(unsigned short vendor_id,
/* Get the filename of the /sys entry for the device /* Get the filename of the /sys entry for the device
and create a udev_device object (dev) representing it */ and create a udev_device object (dev) representing it */
sysfs_path = udev_list_entry_get_name(dev_list_entry); sysfs_path = udev_syms->udev_list_entry_get_name(dev_list_entry);
raw_dev = udev_device_new_from_syspath(udev, sysfs_path); raw_dev = udev_syms->udev_device_new_from_syspath(udev, sysfs_path);
dev_path = udev_device_get_devnode(raw_dev); dev_path = udev_syms->udev_device_get_devnode(raw_dev);
hid_dev = udev_device_get_parent_with_subsystem_devtype( hid_dev = udev_syms->udev_device_get_parent_with_subsystem_devtype(
raw_dev, raw_dev,
"hid", "hid",
NULL); NULL);
@ -519,7 +531,7 @@ struct hid_device_info HID_API_EXPORT *hid_enumerate(unsigned short vendor_id,
} }
result = parse_uevent_info( result = parse_uevent_info(
udev_device_get_sysattr_value(hid_dev, "uevent"), udev_syms->udev_device_get_sysattr_value(hid_dev, "uevent"),
&bus_type, &bus_type,
&dev_vid, &dev_vid,
&dev_pid, &dev_pid,
@ -582,7 +594,7 @@ struct hid_device_info HID_API_EXPORT *hid_enumerate(unsigned short vendor_id,
subsystem/devtype pair of "usb"/"usb_device". This will subsystem/devtype pair of "usb"/"usb_device". This will
be several levels up the tree, but the function will find be several levels up the tree, but the function will find
it. */ it. */
usb_dev = udev_device_get_parent_with_subsystem_devtype( usb_dev = udev_syms->udev_device_get_parent_with_subsystem_devtype(
raw_dev, raw_dev,
"usb", "usb",
"usb_device"); "usb_device");
@ -610,16 +622,16 @@ struct hid_device_info HID_API_EXPORT *hid_enumerate(unsigned short vendor_id,
cur_dev->product_string = copy_udev_string(usb_dev, device_string_names[DEVICE_STRING_PRODUCT]); cur_dev->product_string = copy_udev_string(usb_dev, device_string_names[DEVICE_STRING_PRODUCT]);
/* Release Number */ /* Release Number */
str = udev_device_get_sysattr_value(usb_dev, "bcdDevice"); str = udev_syms->udev_device_get_sysattr_value(usb_dev, "bcdDevice");
cur_dev->release_number = (str)? strtol(str, NULL, 16): 0x0; cur_dev->release_number = (str)? strtol(str, NULL, 16): 0x0;
/* Get a handle to the interface's udev node. */ /* Get a handle to the interface's udev node. */
intf_dev = udev_device_get_parent_with_subsystem_devtype( intf_dev = udev_syms->udev_device_get_parent_with_subsystem_devtype(
raw_dev, raw_dev,
"usb", "usb",
"usb_interface"); "usb_interface");
if (intf_dev) { if (intf_dev) {
str = udev_device_get_sysattr_value(intf_dev, "bInterfaceNumber"); str = udev_syms->udev_device_get_sysattr_value(intf_dev, "bInterfaceNumber");
cur_dev->interface_number = (str)? strtol(str, NULL, 16): -1; cur_dev->interface_number = (str)? strtol(str, NULL, 16): -1;
} }
@ -642,14 +654,14 @@ struct hid_device_info HID_API_EXPORT *hid_enumerate(unsigned short vendor_id,
next: next:
free(serial_number_utf8); free(serial_number_utf8);
free(product_name_utf8); free(product_name_utf8);
udev_device_unref(raw_dev); udev_syms->udev_device_unref(raw_dev);
/* hid_dev, usb_dev and intf_dev don't need to be (and can't be) /* hid_dev, usb_dev and intf_dev don't need to be (and can't be)
unref()d. It will cause a double-free() error. I'm not unref()d. It will cause a double-free() error. I'm not
sure why. */ sure why. */
} }
/* Free the enumerator and udev objects. */ /* Free the enumerator and udev objects. */
udev_enumerate_unref(enumerate); udev_syms->udev_enumerate_unref(enumerate);
udev_unref(udev); udev_syms->udev_unref(udev);
return root; return root;
} }