功能：接入Linux原生光标并完善设备接入工具

terminal/native-cursor/capture-no-cursor.c

@@ -0,0 +1,54 @@
+/* Linux/glibc X11 capture adapter. Only preload into a leased Sunshine process.
+ * Sunshine resolves XFixesGetCursorImage with dlsym(), so a plain symbol
+ * interposer is insufficient. No system library or desktop theme is replaced.
+ * ABI matches XFixesCursorImage from the Xorg Xfixes.h public header.
+ */
+#define _GNU_SOURCE
+#include <stddef.h>
+extern void *dlvsym(void *, const char *, const char *);
+extern char *getenv(const char *);
+extern int strcmp(const char *, const char *);
+extern void abort(void);
+extern int open(const char *, int, ...);
+extern long write(int, const void *, unsigned long);
+extern int close(int);
+typedef struct {
+    short x, y;
+    unsigned short width, height, xhot, yhot;
+    unsigned long serial;
+    unsigned long *pixels;
+    unsigned long atom;
+    const char *name;
+} CursorImage;
+typedef void *(*Lookup)(void *, const char *);
+typedef CursorImage *(*GetImage)(void *);
+static GetImage real_image;
+
+static CursorImage *capture_image(void *display) {
+    GetImage fn = __atomic_load_n(&real_image, __ATOMIC_ACQUIRE);
+    if (!fn) abort();
+    CursorImage *image = fn(display);
+    if (image && image->pixels) {
+        unsigned long n = (unsigned long)image->width * image->height;
+        if (n > 1048576) abort();
+        for (unsigned long i = 0; i < n; ++i) image->pixels[i] = 0;
+    }
+    return image;
+}
+
+void *dlsym(void *handle, const char *name) {
+    Lookup lookup = (Lookup)dlvsym((void *)-1L, "dlsym", "GLIBC_2.2.5");
+    if (!lookup) abort();
+    void *result = lookup(handle, name);
+    if (result && getenv("VDI_CURSOR_LEASE") &&
+            strcmp(name, "XFixesGetCursorImage") == 0) {
+        __atomic_store_n(&real_image, (GetImage)result, __ATOMIC_RELEASE);
+        const char *receipt = getenv("VDI_CURSOR_RECEIPT");
+        if (receipt) {
+            int fd = open(receipt, 0101 | 01000 | 02000000, 0600);
+            if (fd >= 0) { write(fd, "xfixes-v1\n", 10); close(fd); }
+        }
+        return (void *)capture_image;
+    }
+    return result;
+}