initial commit, 4.5 stable

thirdparty/sdl/core/linux/SDL_udev.c

@@ -0,0 +1,597 @@
+/*
+  Simple DirectMedia Layer
+  Copyright (C) 1997-2025 Sam Lantinga <slouken@libsdl.org>
+
+  This software is provided 'as-is', without any express or implied
+  warranty.  In no event will the authors be held liable for any damages
+  arising from the use of this software.
+
+  Permission is granted to anyone to use this software for any purpose,
+  including commercial applications, and to alter it and redistribute it
+  freely, subject to the following restrictions:
+
+  1. The origin of this software must not be misrepresented; you must not
+     claim that you wrote the original software. If you use this software
+     in a product, an acknowledgment in the product documentation would be
+     appreciated but is not required.
+  2. Altered source versions must be plainly marked as such, and must not be
+     misrepresented as being the original software.
+  3. This notice may not be removed or altered from any source distribution.
+*/
+#include "SDL_internal.h"
+
+/*
+ * To list the properties of a device, try something like:
+ * udevadm info -a -n snd/hwC0D0 (for a sound card)
+ * udevadm info --query=all -n input/event3 (for a keyboard, mouse, etc)
+ * udevadm info --query=property -n input/event2
+ */
+#include "SDL_udev.h"
+
+#ifdef SDL_USE_LIBUDEV
+
+#include <linux/input.h>
+#include <sys/stat.h>
+
+#include "SDL_evdev_capabilities.h"
+#include "../unix/SDL_poll.h"
+
+static const char *SDL_UDEV_LIBS[] = { "libudev.so.1", "libudev.so.0" };
+
+SDL_UDEV_PrivateData *SDL_UDEV_PrivateData_this = NULL;
+#define _this SDL_UDEV_PrivateData_this
+
+static bool SDL_UDEV_load_sym(const char *fn, void **addr);
+static bool SDL_UDEV_load_syms(void);
+static bool SDL_UDEV_hotplug_update_available(void);
+static void get_caps(struct udev_device *dev, struct udev_device *pdev, const char *attr, unsigned long *bitmask, size_t bitmask_len);
+static int guess_device_class(struct udev_device *dev);
+static int device_class(struct udev_device *dev);
+static void device_event(SDL_UDEV_deviceevent type, struct udev_device *dev);
+
+static bool SDL_UDEV_load_sym(const char *fn, void **addr)
+{
+    *addr = SDL_LoadFunction(_this->udev_handle, fn);
+    if (!*addr) {
+        // Don't call SDL_SetError(): SDL_LoadFunction already did.
+        return false;
+    }
+
+    return true;
+}
+
+static bool SDL_UDEV_load_syms(void)
+{
+/* cast funcs to char* first, to please GCC's strict aliasing rules. */
+#define SDL_UDEV_SYM(x)                                          \
+    if (!SDL_UDEV_load_sym(#x, (void **)(char *)&_this->syms.x)) \
+        return false
+
+    SDL_UDEV_SYM(udev_device_get_action);
+    SDL_UDEV_SYM(udev_device_get_devnode);
+    SDL_UDEV_SYM(udev_device_get_syspath);
+    SDL_UDEV_SYM(udev_device_get_subsystem);
+    SDL_UDEV_SYM(udev_device_get_parent_with_subsystem_devtype);
+    SDL_UDEV_SYM(udev_device_get_property_value);
+    SDL_UDEV_SYM(udev_device_get_sysattr_value);
+    SDL_UDEV_SYM(udev_device_new_from_syspath);
+    SDL_UDEV_SYM(udev_device_unref);
+    SDL_UDEV_SYM(udev_enumerate_add_match_property);
+    SDL_UDEV_SYM(udev_enumerate_add_match_subsystem);
+    SDL_UDEV_SYM(udev_enumerate_get_list_entry);
+    SDL_UDEV_SYM(udev_enumerate_new);
+    SDL_UDEV_SYM(udev_enumerate_scan_devices);
+    SDL_UDEV_SYM(udev_enumerate_unref);
+    SDL_UDEV_SYM(udev_list_entry_get_name);
+    SDL_UDEV_SYM(udev_list_entry_get_next);
+    SDL_UDEV_SYM(udev_monitor_enable_receiving);
+    SDL_UDEV_SYM(udev_monitor_filter_add_match_subsystem_devtype);
+    SDL_UDEV_SYM(udev_monitor_get_fd);
+    SDL_UDEV_SYM(udev_monitor_new_from_netlink);
+    SDL_UDEV_SYM(udev_monitor_receive_device);
+    SDL_UDEV_SYM(udev_monitor_unref);
+    SDL_UDEV_SYM(udev_new);
+    SDL_UDEV_SYM(udev_unref);
+    SDL_UDEV_SYM(udev_device_new_from_devnum);
+    SDL_UDEV_SYM(udev_device_get_devnum);
+#undef SDL_UDEV_SYM
+
+    return true;
+}
+
+static bool SDL_UDEV_hotplug_update_available(void)
+{
+    if (_this->udev_mon) {
+        const int fd = _this->syms.udev_monitor_get_fd(_this->udev_mon);
+        if (SDL_IOReady(fd, SDL_IOR_READ, 0)) {
+            return true;
+        }
+    }
+    return false;
+}
+
+bool SDL_UDEV_Init(void)
+{
+    if (!_this) {
+        _this = (SDL_UDEV_PrivateData *)SDL_calloc(1, sizeof(*_this));
+        if (!_this) {
+            return false;
+        }
+
+        if (!SDL_UDEV_LoadLibrary()) {
+            SDL_UDEV_Quit();
+            return false;
+        }
+
+        /* Set up udev monitoring
+         * Listen for input devices (mouse, keyboard, joystick, etc) and sound devices
+         */
+
+        _this->udev = _this->syms.udev_new();
+        if (!_this->udev) {
+            SDL_UDEV_Quit();
+            return SDL_SetError("udev_new() failed");
+        }
+
+        _this->udev_mon = _this->syms.udev_monitor_new_from_netlink(_this->udev, "udev");
+        if (!_this->udev_mon) {
+            SDL_UDEV_Quit();
+            return SDL_SetError("udev_monitor_new_from_netlink() failed");
+        }
+
+        _this->syms.udev_monitor_filter_add_match_subsystem_devtype(_this->udev_mon, "input", NULL);
+        _this->syms.udev_monitor_filter_add_match_subsystem_devtype(_this->udev_mon, "sound", NULL);
+        _this->syms.udev_monitor_filter_add_match_subsystem_devtype(_this->udev_mon, "video4linux", NULL);
+        _this->syms.udev_monitor_enable_receiving(_this->udev_mon);
+
+        // Do an initial scan of existing devices
+        SDL_UDEV_Scan();
+    }
+
+    _this->ref_count += 1;
+
+    return true;
+}
+
+void SDL_UDEV_Quit(void)
+{
+    if (!_this) {
+        return;
+    }
+
+    _this->ref_count -= 1;
+
+    if (_this->ref_count < 1) {
+
+        if (_this->udev_mon) {
+            _this->syms.udev_monitor_unref(_this->udev_mon);
+            _this->udev_mon = NULL;
+        }
+        if (_this->udev) {
+            _this->syms.udev_unref(_this->udev);
+            _this->udev = NULL;
+        }
+
+        // Remove existing devices
+        while (_this->first) {
+            SDL_UDEV_CallbackList *item = _this->first;
+            _this->first = _this->first->next;
+            SDL_free(item);
+        }
+
+        SDL_UDEV_UnloadLibrary();
+        SDL_free(_this);
+        _this = NULL;
+    }
+}
+
+bool SDL_UDEV_Scan(void)
+{
+    struct udev_enumerate *enumerate = NULL;
+    struct udev_list_entry *devs = NULL;
+    struct udev_list_entry *item = NULL;
+
+    if (!_this) {
+        return true;
+    }
+
+    enumerate = _this->syms.udev_enumerate_new(_this->udev);
+    if (!enumerate) {
+        SDL_UDEV_Quit();
+        return SDL_SetError("udev_enumerate_new() failed");
+    }
+
+    _this->syms.udev_enumerate_add_match_subsystem(enumerate, "input");
+    _this->syms.udev_enumerate_add_match_subsystem(enumerate, "sound");
+    _this->syms.udev_enumerate_add_match_subsystem(enumerate, "video4linux");
+
+    _this->syms.udev_enumerate_scan_devices(enumerate);
+    devs = _this->syms.udev_enumerate_get_list_entry(enumerate);
+    for (item = devs; item; item = _this->syms.udev_list_entry_get_next(item)) {
+        const char *path = _this->syms.udev_list_entry_get_name(item);
+        struct udev_device *dev = _this->syms.udev_device_new_from_syspath(_this->udev, path);
+        if (dev) {
+            device_event(SDL_UDEV_DEVICEADDED, dev);
+            _this->syms.udev_device_unref(dev);
+        }
+    }
+
+    _this->syms.udev_enumerate_unref(enumerate);
+    return true;
+}
+
+bool SDL_UDEV_GetProductInfo(const char *device_path, Uint16 *vendor, Uint16 *product, Uint16 *version, int *class)
+{
+    struct stat statbuf;
+    char type;
+    struct udev_device *dev;
+    const char* val;
+    int class_temp;
+
+    if (!_this) {
+        return false;
+    }
+
+    if (stat(device_path, &statbuf) == -1) {
+        return false;
+    }
+
+    if (S_ISBLK(statbuf.st_mode)) {
+        type = 'b';
+    }
+    else if (S_ISCHR(statbuf.st_mode)) {
+        type = 'c';
+    }
+    else {
+        return false;
+    }
+
+    dev = _this->syms.udev_device_new_from_devnum(_this->udev, type, statbuf.st_rdev);
+
+    if (!dev) {
+        return false;
+    }
+
+    val = _this->syms.udev_device_get_property_value(dev, "ID_VENDOR_ID");
+    if (val) {
+        *vendor = (Uint16)SDL_strtol(val, NULL, 16);
+    }
+
+    val = _this->syms.udev_device_get_property_value(dev, "ID_MODEL_ID");
+    if (val) {
+        *product = (Uint16)SDL_strtol(val, NULL, 16);
+    }
+
+    val = _this->syms.udev_device_get_property_value(dev, "ID_REVISION");
+    if (val) {
+        *version = (Uint16)SDL_strtol(val, NULL, 16);
+    }
+
+    class_temp = device_class(dev);
+    if (class_temp) {
+        *class = class_temp;
+    }
+
+    _this->syms.udev_device_unref(dev);
+
+    return true;
+}
+
+void SDL_UDEV_UnloadLibrary(void)
+{
+    if (!_this) {
+        return;
+    }
+
+    if (_this->udev_handle) {
+        SDL_UnloadObject(_this->udev_handle);
+        _this->udev_handle = NULL;
+    }
+}
+
+bool SDL_UDEV_LoadLibrary(void)
+{
+    bool result = true;
+
+    if (!_this) {
+        return SDL_SetError("UDEV not initialized");
+    }
+
+    // See if there is a udev library already loaded
+    if (SDL_UDEV_load_syms()) {
+        return true;
+    }
+
+#ifdef SDL_UDEV_DYNAMIC
+    // Check for the build environment's libudev first
+    if (!_this->udev_handle) {
+        _this->udev_handle = SDL_LoadObject(SDL_UDEV_DYNAMIC);
+        if (_this->udev_handle) {
+            result = SDL_UDEV_load_syms();
+            if (!result) {
+                SDL_UDEV_UnloadLibrary();
+            }
+        }
+    }
+#endif
+
+    if (!_this->udev_handle) {
+        for (int i = 0; i < SDL_arraysize(SDL_UDEV_LIBS); i++) {
+            _this->udev_handle = SDL_LoadObject(SDL_UDEV_LIBS[i]);
+            if (_this->udev_handle) {
+                result = SDL_UDEV_load_syms();
+                if (!result) {
+                    SDL_UDEV_UnloadLibrary();
+                } else {
+                    break;
+                }
+            }
+        }
+
+        if (!_this->udev_handle) {
+            result = false;
+            // Don't call SDL_SetError(): SDL_LoadObject already did.
+        }
+    }
+
+    return result;
+}
+
+static void get_caps(struct udev_device *dev, struct udev_device *pdev, const char *attr, unsigned long *bitmask, size_t bitmask_len)
+{
+    const char *value;
+    char text[4096];
+    char *word;
+    int i;
+    unsigned long v;
+
+    SDL_memset(bitmask, 0, bitmask_len * sizeof(*bitmask));
+    value = _this->syms.udev_device_get_sysattr_value(pdev, attr);
+    if (!value) {
+        return;
+    }
+
+    SDL_strlcpy(text, value, sizeof(text));
+    i = 0;
+    while ((word = SDL_strrchr(text, ' ')) != NULL) {
+        v = SDL_strtoul(word + 1, NULL, 16);
+        if (i < bitmask_len) {
+            bitmask[i] = v;
+        }
+        ++i;
+        *word = '\0';
+    }
+    v = SDL_strtoul(text, NULL, 16);
+    if (i < bitmask_len) {
+        bitmask[i] = v;
+    }
+}
+
+static int guess_device_class(struct udev_device *dev)
+{
+    struct udev_device *pdev;
+    unsigned long bitmask_props[NBITS(INPUT_PROP_MAX)];
+    unsigned long bitmask_ev[NBITS(EV_MAX)];
+    unsigned long bitmask_abs[NBITS(ABS_MAX)];
+    unsigned long bitmask_key[NBITS(KEY_MAX)];
+    unsigned long bitmask_rel[NBITS(REL_MAX)];
+
+    /* walk up the parental chain until we find the real input device; the
+     * argument is very likely a subdevice of this, like eventN */
+    pdev = dev;
+    while (pdev && !_this->syms.udev_device_get_sysattr_value(pdev, "capabilities/ev")) {
+        pdev = _this->syms.udev_device_get_parent_with_subsystem_devtype(pdev, "input", NULL);
+    }
+    if (!pdev) {
+        return 0;
+    }
+
+    get_caps(dev, pdev, "properties", bitmask_props, SDL_arraysize(bitmask_props));
+    get_caps(dev, pdev, "capabilities/ev", bitmask_ev, SDL_arraysize(bitmask_ev));
+    get_caps(dev, pdev, "capabilities/abs", bitmask_abs, SDL_arraysize(bitmask_abs));
+    get_caps(dev, pdev, "capabilities/rel", bitmask_rel, SDL_arraysize(bitmask_rel));
+    get_caps(dev, pdev, "capabilities/key", bitmask_key, SDL_arraysize(bitmask_key));
+
+    return SDL_EVDEV_GuessDeviceClass(&bitmask_props[0],
+                                      &bitmask_ev[0],
+                                      &bitmask_abs[0],
+                                      &bitmask_key[0],
+                                      &bitmask_rel[0]);
+}
+
+static int device_class(struct udev_device *dev)
+{
+    const char *subsystem;
+    const char *val = NULL;
+    int devclass = 0;
+
+    subsystem = _this->syms.udev_device_get_subsystem(dev);
+    if (!subsystem) {
+        return 0;
+    }
+
+    if (SDL_strcmp(subsystem, "sound") == 0) {
+        devclass = SDL_UDEV_DEVICE_SOUND;
+    } else if (SDL_strcmp(subsystem, "video4linux") == 0) {
+        val = _this->syms.udev_device_get_property_value(dev, "ID_V4L_CAPABILITIES");
+        if (val && SDL_strcasestr(val, "capture")) {
+            devclass = SDL_UDEV_DEVICE_VIDEO_CAPTURE;
+        }
+    } else if (SDL_strcmp(subsystem, "input") == 0) {
+        // udev rules reference: http://cgit.freedesktop.org/systemd/systemd/tree/src/udev/udev-builtin-input_id.c
+
+        val = _this->syms.udev_device_get_property_value(dev, "ID_INPUT_JOYSTICK");
+        if (val && SDL_strcmp(val, "1") == 0) {
+            devclass |= SDL_UDEV_DEVICE_JOYSTICK;
+        }
+
+        val = _this->syms.udev_device_get_property_value(dev, "ID_INPUT_ACCELEROMETER");
+        if (val && SDL_strcmp(val, "1") == 0) {
+            devclass |= SDL_UDEV_DEVICE_ACCELEROMETER;
+        }
+
+        val = _this->syms.udev_device_get_property_value(dev, "ID_INPUT_MOUSE");
+        if (val && SDL_strcmp(val, "1") == 0) {
+            devclass |= SDL_UDEV_DEVICE_MOUSE;
+        }
+
+        val = _this->syms.udev_device_get_property_value(dev, "ID_INPUT_TOUCHSCREEN");
+        if (val && SDL_strcmp(val, "1") == 0) {
+            devclass |= SDL_UDEV_DEVICE_TOUCHSCREEN;
+        }
+
+        /* The undocumented rule is:
+           - All devices with keys get ID_INPUT_KEY
+           - From this subset, if they have ESC, numbers, and Q to D, it also gets ID_INPUT_KEYBOARD
+
+           Ref: http://cgit.freedesktop.org/systemd/systemd/tree/src/udev/udev-builtin-input_id.c#n183
+        */
+        val = _this->syms.udev_device_get_property_value(dev, "ID_INPUT_KEY");
+        if (val && SDL_strcmp(val, "1") == 0) {
+            devclass |= SDL_UDEV_DEVICE_HAS_KEYS;
+        }
+
+        val = _this->syms.udev_device_get_property_value(dev, "ID_INPUT_KEYBOARD");
+        if (val && SDL_strcmp(val, "1") == 0) {
+            devclass |= SDL_UDEV_DEVICE_KEYBOARD;
+        }
+
+        if (devclass == 0) {
+            // Fall back to old style input classes
+            val = _this->syms.udev_device_get_property_value(dev, "ID_CLASS");
+            if (val) {
+                if (SDL_strcmp(val, "joystick") == 0) {
+                    devclass = SDL_UDEV_DEVICE_JOYSTICK;
+                } else if (SDL_strcmp(val, "mouse") == 0) {
+                    devclass = SDL_UDEV_DEVICE_MOUSE;
+                } else if (SDL_strcmp(val, "kbd") == 0) {
+                    devclass = SDL_UDEV_DEVICE_HAS_KEYS | SDL_UDEV_DEVICE_KEYBOARD;
+                }
+            } else {
+                // We could be linked with libudev on a system that doesn't have udev running
+                devclass = guess_device_class(dev);
+            }
+        }
+    }
+
+    return devclass;
+}
+
+static void device_event(SDL_UDEV_deviceevent type, struct udev_device *dev)
+{
+    int devclass = 0;
+    const char *path;
+    SDL_UDEV_CallbackList *item;
+
+    path = _this->syms.udev_device_get_devnode(dev);
+    if (!path) {
+        return;
+    }
+
+    if (type == SDL_UDEV_DEVICEADDED) {
+        devclass = device_class(dev);
+        if (!devclass) {
+            return;
+        }
+    } else {
+        // The device has been removed, the class isn't available
+    }
+
+    // Process callbacks
+    for (item = _this->first; item; item = item->next) {
+        item->callback(type, devclass, path);
+    }
+}
+
+void SDL_UDEV_Poll(void)
+{
+    struct udev_device *dev = NULL;
+    const char *action = NULL;
+
+    if (!_this) {
+        return;
+    }
+
+    while (SDL_UDEV_hotplug_update_available()) {
+        dev = _this->syms.udev_monitor_receive_device(_this->udev_mon);
+        if (!dev) {
+            break;
+        }
+        action = _this->syms.udev_device_get_action(dev);
+
+        if (action) {
+            if (SDL_strcmp(action, "add") == 0) {
+                device_event(SDL_UDEV_DEVICEADDED, dev);
+            } else if (SDL_strcmp(action, "remove") == 0) {
+                device_event(SDL_UDEV_DEVICEREMOVED, dev);
+            }
+        }
+
+        _this->syms.udev_device_unref(dev);
+    }
+}
+
+bool SDL_UDEV_AddCallback(SDL_UDEV_Callback cb)
+{
+    SDL_UDEV_CallbackList *item;
+    item = (SDL_UDEV_CallbackList *)SDL_calloc(1, sizeof(SDL_UDEV_CallbackList));
+    if (!item) {
+        return false;
+    }
+
+    item->callback = cb;
+
+    if (!_this->last) {
+        _this->first = _this->last = item;
+    } else {
+        _this->last->next = item;
+        _this->last = item;
+    }
+
+    return true;
+}
+
+void SDL_UDEV_DelCallback(SDL_UDEV_Callback cb)
+{
+    SDL_UDEV_CallbackList *item;
+    SDL_UDEV_CallbackList *prev = NULL;
+
+    if (!_this) {
+        return;
+    }
+
+    for (item = _this->first; item; item = item->next) {
+        // found it, remove it.
+        if (item->callback == cb) {
+            if (prev) {
+                prev->next = item->next;
+            } else {
+                SDL_assert(_this->first == item);
+                _this->first = item->next;
+            }
+            if (item == _this->last) {
+                _this->last = prev;
+            }
+            SDL_free(item);
+            return;
+        }
+        prev = item;
+    }
+}
+
+const SDL_UDEV_Symbols *SDL_UDEV_GetUdevSyms(void)
+{
+    if (!SDL_UDEV_Init()) {
+        SDL_SetError("Could not initialize UDEV");
+        return NULL;
+    }
+
+    return &_this->syms;
+}
+
+void SDL_UDEV_ReleaseUdevSyms(void)
+{
+    SDL_UDEV_Quit();
+}
+
+#endif // SDL_USE_LIBUDEV