Feat: patch dylib for game dlopen calls

Now that game can directly load macOS's JNA native library,
libjnidispatch is removed.

Natives/CMakeLists.txt

@@ -99,6 +99,7 @@ target_link_libraries(PojavAccountJNI)
 # PojavLauncher
 add_executable(PojavLauncher
   dyld_bypass_validation.m
+  dyld_patch_platform.m
   main.m
   main_hook.m
   JavaLauncher.m

Natives/JavaLauncher.m

@@ -178,7 +178,6 @@ int launchJVM(NSString *username, id launchTarget, int width, int height, int mi
     margv[++margc] = "-Xms128M";
     margv[++margc] = [NSString stringWithFormat:@"-Xmx%dM", allocmem].UTF8String;
     margv[++margc] = [NSString stringWithFormat:@"-Djava.library.path=%@/Frameworks", NSBundle.mainBundle.bundlePath].UTF8String;
-    margv[++margc] = [NSString stringWithFormat:@"-Djna.boot.library.path=%@/Frameworks", NSBundle.mainBundle.bundlePath].UTF8String;
     margv[++margc] = [NSString stringWithFormat:@"-Duser.dir=%@", gameDir].UTF8String;
     margv[++margc] = [NSString stringWithFormat:@"-Duser.home=%s", getenv("POJAV_HOME")].UTF8String;
     margv[++margc] = [NSString stringWithFormat:@"-Duser.timezone=%@", NSTimeZone.localTimeZone.name].UTF8String;

Natives/dyld_patch_platform.m

@@ -0,0 +1,70 @@
+#import <Foundation/Foundation.h>
+#include <libgen.h>
+#include <mach-o/fat.h>
+#include <mach-o/loader.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+
+extern int dyld_get_active_platform();
+
+static BOOL PLPatchMachOPlatformForSlice(const char *path, struct mach_header_64 *header) {
+    uint8_t *imageHeaderPtr = (uint8_t*)header + sizeof(struct mach_header_64);
+
+    struct load_command *command = (struct load_command *)imageHeaderPtr;
+    for(int i = 0; i < header->ncmds; i++) {
+        if (command->cmd == LC_BUILD_VERSION) {
+            struct build_version_command *buildver = (struct build_version_command *)command;
+            int activePlatform = dyld_get_active_platform();
+            if (buildver->platform == activePlatform) return NO; // it is already set, stop
+            buildver->platform = activePlatform; // set to current platform
+        } else if (command->cmd == LC_LOAD_DYLIB) {
+            struct dylib_command *dylib = (struct dylib_command *)command;
+            char *dylibName = (void *)dylib + dylib->dylib.name.offset;
+            char *verPtr = strstr(dylibName, "/Versions/");
+            if (verPtr) {
+                // Remove "/Versions/X"
+                int lastComponentLen = strlen(dylibName) - (verPtr - dylibName) - 11;
+                memmove(verPtr, verPtr + 11, lastComponentLen);
+                verPtr[lastComponentLen] = '\0';
+            }
+        }
+        command = (struct load_command *)((void *)command + command->cmdsize);
+    }
+    return YES;
+}
+
+
+BOOL PLPatchMachOPlatformForFile(const char *path) {
+    int fd = open(path, O_RDWR, (mode_t)0600);
+    if (fd == -1) return NO;
+    struct stat s;
+    fstat(fd, &s);
+
+    void *map = mmap(NULL, s.st_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
+    if (!map) {
+        close(fd);
+        return NO;
+    }
+
+    BOOL patched = NO;
+    uint32_t magic = *(uint32_t *)map;
+    if (magic == FAT_CIGAM) {
+        // Find compatible slice
+        struct fat_header *header = (struct fat_header *)map;
+        struct fat_arch *arch = (struct fat_arch *)(map + sizeof(struct fat_header));
+        for (int i = 0; i < OSSwapInt32(header->nfat_arch); i++) {
+            if (OSSwapInt32(arch->cputype) == CPU_TYPE_ARM64) {
+                NSLog(@"[PojavLauncher] Patching %s", path);
+                patched |= PLPatchMachOPlatformForSlice(path, (struct mach_header_64 *)(map + OSSwapInt32(arch->offset)));
+            }
+            arch = (struct fat_arch *)((void *)arch + sizeof(struct fat_arch));
+        }
+    } else if (magic == MH_MAGIC_64 && ((struct mach_header_64 *)map)->cputype == CPU_TYPE_ARM64) {
+        patched = PLPatchMachOPlatformForSlice(path, (struct mach_header_64 *)map);
+    }
+
+    if (patched) msync(map, s.st_size, MS_SYNC);
+    munmap(map, s.st_size);
+    close(fd);
+    return patched;
+}

Natives/main_hook.m

@@ -8,6 +8,7 @@
 
 void (*orig_abort)();
 void (*orig_exit)(int code);
+void* (*orig_dlopen)(const char* path, int mode);
 int (*orig_open)(const char *path, int oflag, ...);
 
 void handle_fatal_exit(int code) {
@@ -54,13 +55,27 @@ void hooked_exit(int code) {
     }
     handle_fatal_exit(code);
 
+/*
     if (runtimeJavaVMPtr != NULL) {
         (*runtimeJavaVMPtr)->DestroyJavaVM(runtimeJavaVMPtr);
     }
+*/
 
     orig_exit(code);
 }
 
+void* hooked_dlopen(const char* path, int mode) {
+    const char *home = getenv("POJAV_HOME");
+    // Only proceed to check if dylib is in the home dir
+    // Path input from jvm is absolute path(?)
+    if (!path || strncmp(path, home, strlen(home))) {
+        return orig_dlopen(path, mode);
+    }
+
+    PLPatchMachOPlatformForFile(path);
+    return orig_dlopen(path, mode);
+}
+
 int hooked_open(const char *path, int oflag, ...) {
     va_list args;
     va_start(args, oflag);
@@ -78,6 +93,7 @@ void init_hookFunctions() {
         {"abort", hooked_abort, (void *)&orig_abort},
         {"__assert_rtn", hooked___assert_rtn, NULL},
         {"exit", hooked_exit, (void *)&orig_exit},
+        {"dlopen", hooked_dlopen, (void *)&orig_dlopen},
         {"open", hooked_open, (void *)&orig_open}
     };
     rebind_symbols(rebindings, sizeof(rebindings)/sizeof(struct rebinding));

Natives/utils.h

@@ -63,6 +63,8 @@ void init_hookFunctions();
 void init_hookUIKitConstructor();
 void init_setupMultiDir();
 
+BOOL PLPatchMachOPlatformForFile(const char *path);
+
 UIWindow* currentWindow();
 UIWindow* currentWindowInScene(BOOL external);
 UIViewController* currentVC();

README.md

@@ -96,7 +96,6 @@ PojavLauncher is amazing, and surprisingly stable, and it wouldn't be this way w
 - [LWJGLX](https://github.com/PojavLauncherTeam/lwjglx) (LWJGL2 API compatibility layer for LWJGL3): unknown license.
 - [DBNumberedSlider](https://github.com/khanhduytran0/DBNumberedSlider): [Apache 2.0 License](https://github.com/immago/DBNumberedSlider/blob/master/LICENSE)
 - [fishhook](https://github.com/khanhduytran0/fishhook): [BSD-3 License](https://github.com/facebook/fishhook/blob/main/LICENSE).
-- [Java Native Access](https://github.com/java-native-access/jna): [Apache 2.0 License](https://github.com/java-native-access/jna/blob/master/LICENSE).
 - [shaderc](https://github.com/khanhduytran0/shaderc) (used by Vulkan rendering mods): [Apache 2.0 License](https://github.com/google/shaderc/blob/main/LICENSE).
 - [NRFileManager](https://github.com/mozilla-mobile/firefox-ios/tree/b2f89ac40835c5988a1a3eb642982544e00f0f90/ThirdParty/NRFileManager): [MPL-2.0 License](https://www.mozilla.org/en-US/MPL/2.0)
 - [AltKit](https://github.com/rileytestut/AltKit)