mcpelauncher support

Author: Zeuroux

Cargo.toml

@@ -9,13 +9,10 @@ ctor = "0.4"
 log = "0.4"
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
+libc = "0.2"
 
 [target.'cfg(target_os = "android")'.dependencies]
 jni = "0.21"
-elf = "0.8"
-
-[target.'cfg(target_os = "linux")'.dependencies]
-elf = "0.8"
 
 [target.'cfg(target_os = "windows")'.dependencies]
 windows-sys = { version = "0.52", features = [

src/config.rs

@@ -11,26 +11,38 @@ static CONFIG_DIR: OnceLock<String> = OnceLock::new();
 const CONFIG_FILE: &str = "dimensions.json";
 const LOG_FILE: &str = "log.txt";
 
-pub fn config_path() -> Option<PathBuf> { CONFIG_DIR.get().map(|d| Path::new(d).join(CONFIG_FILE)) }
-pub fn log_path() -> Option<PathBuf> { CONFIG_DIR.get().map(|d| Path::new(d).join(LOG_FILE)) }
+pub fn config_path() -> Option<PathBuf> { 
+    CONFIG_DIR.get().map(|d| Path::new(d).join(CONFIG_FILE)) 
+}
+pub fn log_path() -> Option<PathBuf> { 
+    CONFIG_DIR.get().map(|d| Path::new(d).join(LOG_FILE)) 
+}
 
-fn set_config_dir(path: String) { if CONFIG_DIR.set(path).is_err() { log::error!("CONFIG_DIR can only be set once"); } }
+fn set_config_dir(path: String) { 
+    if CONFIG_DIR.set(path).is_err() { log::error!("CONFIG_DIR can only be set once"); } 
+}
 
 pub fn save() -> Result<(), ()> {
     let defaults: BuildLimitMap = [
         ("Overworld", BuildLimit { min: -64, max: 320 }),
         ("Nether",    BuildLimit { min: 0,  max: 128 }),
         ("TheEnd",    BuildLimit { min: 0,  max: 256 })
     ].into_iter().map(|(k,v)| (k.to_string(), v)).collect();
-    fs::write(config_path().ok_or_else(|| { log::error!("CONFIG_DIR is not set"); () })?,serde_json::to_string_pretty(&defaults).map_err(|e| log::error!("Serialize failed: {e}"))?)
+    fs::write(config_path().ok_or_else(
+        || { log::error!("CONFIG_DIR is not set"); () })?,
+        serde_json::to_string_pretty(&defaults)
+        .map_err(|e| log::error!("Serialize failed: {e}"))?)
         .map_err(|e| log::error!("Write failed: {e}"))?;
     Ok(())
 }
 
 pub fn load() -> BuildLimitMap {
     let path = match config_path() { 
         Some(p) => p,
-        None => { log::error!("CONFIG_DIR not set"); return BuildLimitMap::new(); } 
+        None => { 
+            log::error!("CONFIG_DIR not set");
+            return BuildLimitMap::new(); 
+        } 
     };
     let content = fs::read_to_string(&path).unwrap_or_else(|_| {
         save().ok();
@@ -42,17 +54,11 @@ pub fn load() -> BuildLimitMap {
     })
 }
 
-#[cfg_attr(target_os = "android", no_mangle)]
-pub fn init_config(#[cfg(target_os = "android")] env: &mut jni::JNIEnv) {
-    let mut path = (|| { crate::utils::get_config_directory(#[cfg(target_os = "android")] env) })().unwrap_or_else(|| { 
-        log::error!("Failed to get a valid config directory");
-        String::new()
-    });
-    
+pub fn init_config(path: &mut String) {    
     path.push_str("/BuildLimitChanger/");
-    if !is_dir_writable(&path) { log::error!("Config directory not writable: {}", path); return; }
-    set_config_dir(path.clone());
-    if !config_path().map_or(false, |p| p.exists()) { 
-        save().ok();
+    if !is_dir_writable(&path) { 
+        return log::error!("Config directory not writable: {}", path);
     }
+    set_config_dir(path.clone());
+    if !config_path().map_or(false, |p| p.exists()) { save().ok(); }
 }

src/lib.rs

@@ -1,10 +1,9 @@
+#![allow(non_snake_case)]
 mod config;
 mod hook;
 mod logger;
 mod utils;
 
-use std::time::Instant;
-
 fn find_water_mob_cap_and_fn_starts(data: &[u8]) -> (Option<usize>, Vec<usize>) {
     let mut seen_ret = false;
     let mut possible_fn_starts = Vec::new();
@@ -15,7 +14,6 @@ fn find_water_mob_cap_and_fn_starts(data: &[u8]) -> (Option<usize>, Vec<usize>)
     #[cfg(target_arch = "aarch64")] {
         const MASKS: [u32; 3] = [0xFFFF_FC1F, 0xFFFF_FFE0, 0xFF00_0000];
         const PATTERNS: [u32; 3] = [0xD65F_0000, 0x52A8_4200, 0xD100_0000];
-
         for inst in data.chunks_exact(4) {
             let addr = inst.as_ptr() as usize;
             let instr = u32::from_le_bytes(inst.try_into().unwrap());
@@ -45,7 +43,6 @@ fn find_water_mob_cap_and_fn_starts(data: &[u8]) -> (Option<usize>, Vec<usize>)
         let mut instruction = Instruction::default();
 
         const TARGET_IMMEDIATE: u64 = 0x42100000;
-
         while decoder.can_decode() {
             decoder.decode_out(&mut instruction);
 
@@ -83,43 +80,49 @@ fn find_water_mob_cap_and_fn_starts(data: &[u8]) -> (Option<usize>, Vec<usize>)
     (water_mob_cap, possible_fn_starts)
 }
 
-#[ctor::ctor]
+#[cfg_attr(target_os = "android", no_mangle)]
 fn init() {
-    println!("Starting BuildLimitChanger");
-    let time_start = Instant::now();
-    log::set_logger(&logger::LOGGER).expect("Logger already set");
-    log::set_max_level(log::LevelFilter::Debug);
-
-    #[cfg(any(target_os = "windows", target_os = "linux"))] {
-        crate::config::init_config();
-        crate::logger::init_log_file(false);
-    }
-    let mcmap = utils::find_minecraft_text_section().expect("Cannot find Minecraft .text section");
+    let time_start = std::time::Instant::now();
+    let mcmap = utils::find_minecraft_text_section().unwrap_or_else(|e|  { panic!("Cannot find Minecraft .text section: {}", e.to_string()) });
     let data = unsafe { std::slice::from_raw_parts(mcmap.start as *const u8, mcmap.size) };
-
     let (water_mob_cap, possible_fn_starts) = find_water_mob_cap_and_fn_starts(data);
-
-    if water_mob_cap.is_none() {
-        log::error!("Cannot find the water mob cap");
-        return;
-    }
+    if water_mob_cap.is_none() { return log::error!("Cannot find the water mob cap"); }
     let Some(function_addr) = utils::find_max_less_than(&possible_fn_starts, water_mob_cap.unwrap()) else {
-        log::error!("Cannot get the function where water mob cap is located");
-        return;
+        return log::error!("Cannot get the function where water mob cap is located");
     };
     log::debug!("Function Offset: 0x{:X}", function_addr);
     log::debug!("{:02X?}", &data[function_addr - mcmap.start..(function_addr - mcmap.start + 10).min(data.len())]);
-
     hook::setup_hook(function_addr);
     log::debug!("{:02X?}", &data[function_addr - mcmap.start..(function_addr - mcmap.start + 10).min(data.len())]);
     log::info!("Took: {:?}", time_start.elapsed());
 }
 
+#[ctor::ctor]
+fn main() {
+    println!("Starting BuildLimitChanger");
+    log::set_logger(&logger::LOGGER).expect("Logger already set");
+    log::set_max_level(log::LevelFilter::Debug);
+    #[cfg(any(target_os = "linux", target_os = "windows"))] {
+        config::init_config(&mut utils::get_config_directory().expect("Failed to get a valid config directory"));
+        logger::init_log_file(false);
+        init(); 
+    } 
+}
+
+#[cfg(target_os = "android")]
+#[no_mangle]
+pub extern "C" fn mod_init() {
+    config::init_config(&mut String::from("/data/data/com.mojang.minecraftpe"));
+    logger::init_log_file(false);
+    init();
+}
+
 #[cfg(target_os = "android")]
 #[no_mangle]
 pub extern "system" fn JNI_OnLoad(vm: jni::JavaVM, _: *mut core::ffi::c_void) -> i32 {
     let mut env = vm.get_env().expect("Cannot get reference to the JNIEnv");
-    config::init_config(&mut env);
-    logger::init_log_file(crate::utils::is_levi_launcher(&mut env));
+    config::init_config(&mut utils::get_config_directory(&mut env).expect("Failed to get a valid config directory"));
+    logger::init_log_file(utils::is_levi_launcher(&mut env));
+    init();
     return jni::sys::JNI_VERSION_1_6;
 }