Add symbols for non-windows dll proxying

Signed-off-by: Dimitris Zervas <dzervas@dzervas.gr>

.gitignore

@@ -8,3 +8,4 @@ __handlers__
 /examples/cs/bin
 /examples/cs/obj
 /dotnet
+src/symbols.rs

build.rs

@@ -1,4 +1,7 @@
 use std::env;
+use std::io::Write;
+use std::fs::File;
+use std::path::Path;
 #[cfg(feature = "dotnet")]
 use csbindgen;
 
@@ -6,64 +9,78 @@ fn main() {
 	println!("cargo:rerun-if-env-changed=FRIDA_CODE");
 	println!("cargo:rerun-if-env-changed=DLL_PROXY");
 
-	if let Ok(lib_path) = env::var("DLL_PROXY") {
+	let Ok(lib_path) = env::var("DLL_PROXY") else {
-		println!("cargo:rerun-if-changed={}", &lib_path);
+		return;
-		use goblin::Object;
+	};
 
-		let path = std::path::Path::new(&lib_path);
+	use goblin::Object;
-		let lib_filename = path.file_name().unwrap().to_str().unwrap();
+	println!("cargo:rerun-if-changed={}", &lib_path);
 
-		let lib_bytes = std::fs::read(path).expect(format!("Failed to open given library file {}", &lib_filename).as_str());
+	let path = std::path::Path::new(&lib_path);
-		let object = Object::parse(&lib_bytes).expect(format!("Failed to parse given libary file {}", &lib_filename).as_str());
+	let lib_filename = path.file_name().unwrap().to_str().unwrap();
 
-		let (exports, lib_name): (Vec<&str>, String) = match object {
+	let lib_bytes = std::fs::read(path).expect(format!("Failed to open given library file {}", &lib_filename).as_str());
-			#[cfg(target_os = "windows")]
+	let object = Object::parse(&lib_bytes).expect(format!("Failed to parse given libary file {}", &lib_filename).as_str());
-			Object::PE(o) => {
-				(o.exports
-					.iter()
-					.map(|e| e.name.unwrap())
-					.collect(),
-				o.name.expect("Couldn't read the name of the DLL. Is it a .NET DLL? It's not supported").replace(".dll", ""))
-			}
-			#[cfg(target_os = "linux")]
-			Object::Elf(o) => {
-				(o.dynsyms
-					.iter()
-					.filter(|e| e.is_function() && !e.is_import())
-					.map(|e| o.dynstrtab.get_at(e.st_name).unwrap())
-					.collect(),
-				o.soname.expect("Couldn't read the name of the SO.").replace(".so", ""))
-			},
-			// #[cfg(target_os = "darwin")]
-			// Object::Mach(goblin::mach::Mach::Binary(o)) => {
-			// 	(o.dynsyms
-			// 		.iter()
-			// 		.filter(|e| e.is_function() && !e.is_import())
-			// 		.map(|e| o.dynstrtab.get_at(e.st_name).unwrap())
-			// 		.collect(),
-			// 	o.name.expect("Couldn't read the name of the DLL. Is it a .NET DLL? It's not supported").replace(".dll", ""))
-			// },
-			_ => {
-				println!("Only PE (.dll) and ELF (.so) files are supported in their respective target platforms.");
-				std::process::exit(1);
-			},
-		};
 
+	let (exports, lib_name): (Vec<&str>, String) = match object {
 		#[cfg(target_os = "windows")]
-		for e in exports.iter() {
+		Object::PE(o) => {
-			println!("cargo:warning=Exported function: {} => {}-orig.{}", e, lib_name, e);
+			(o.exports
-			println!("cargo:rustc-link-arg=/export:{}={}-orig.{}", e, lib_name, e);
+				.iter()
+				.map(|e| e.name.unwrap())
+				.collect(),
+			o.name.expect("Couldn't read the name of the DLL. Is it a .NET DLL? It's not supported").replace(".dll", ""))
 		}
+		#[cfg(target_os = "linux")]
+		Object::Elf(o) => {
+			(o.dynsyms
+				.iter()
+				.filter(|e| e.is_function() && !e.is_import())
+				.map(|e| o.dynstrtab.get_at(e.st_name).unwrap())
+				.collect(),
+			o.soname.expect("Couldn't read the name of the SO.").replace(".so", ""))
+		},
+		// #[cfg(target_os = "darwin")]
+		// Object::Mach(goblin::mach::Mach::Binary(o)) => {
+		// 	(o.dynsyms
+		// 		.iter()
+		// 		.filter(|e| e.is_function() && !e.is_import())
+		// 		.map(|e| o.dynstrtab.get_at(e.st_name).unwrap())
+		// 		.collect(),
+		// 	o.name.expect("Couldn't read the name of the DLL. Is it a .NET DLL? It's not supported").replace(".dll", ""))
+		// },
+		_ => {
+			println!("Only PE (.dll) and ELF (.so) files are supported in their respective target platforms.");
+			std::process::exit(1);
+		},
+	};
 
-		#[cfg(not(target_os = "windows"))]
+	#[cfg(target_os = "windows")]
+	for e in exports.iter() {
+		println!("cargo:warning=Exported function: {} => {}-orig.{}", e, lib_name, e);
+		println!("cargo:rustc-link-arg=/export:{}={}-orig.{}", e, lib_name, e);
+	}
+
+	#[cfg(not(target_os = "windows"))]
+	{
+		let symbols_path = Path::new(env!("CARGO_MANIFEST_DIR")).join("src").join("symbols.rs");
+		let mut symbols = File::create(&symbols_path).unwrap();
+		println!("cargo:rerun-if-changed={:?}", symbols_path);
+
+		writeln!(symbols, "#[allow(dead_code)]").unwrap();
+		writeln!(symbols, "#[link(name = \"{}\")]", lib_name.replace("lib", "")).unwrap();
+		writeln!(symbols, "extern {{").unwrap();
 		for e in exports.iter() {
 			println!("cargo:warning=Exported function: {}", e);
+			// writeln!(symbols, "\t#[no_mangle]").unwrap();
+			writeln!(symbols, "\tpub fn {}();", e).unwrap();
 		}
-
+		writeln!(symbols, "}}").unwrap();
-		println!("cargo:warning=Expected library name: {}-orig.dll", lib_name);
-		println!("cargo:rustc-env=LIB_NAME={}-orig.dll", lib_name);
 	}
 
+	println!("cargo:warning=Expected library name: {}-orig.dll", lib_name);
+	println!("cargo:rustc-env=LIB_NAME={}-orig.dll", lib_name);
+
 	#[cfg(feature = "dotnet")]
 	{
 		let lib_path = concat!(env!("CARGO_MANIFEST_DIR"), "/src/lib.rs");

src/lib.rs

@@ -3,6 +3,8 @@ pub mod injector;
 pub mod frida_handler;
 // #[cfg(feature = "dotnet")]
 // pub mod cs;
+#[cfg(not(windows))]
+pub mod symbols;
 
 pub use injector::attach_self;