macho get_function_offset read function_name len

Author: AlexKnauth

src/file_format/macho.rs

@@ -1,6 +1,6 @@
 //! Support for parsing MachO files
 
-use crate::{Process, string::ArrayCString};
+use crate::Process;
 
 use core::mem;
 
@@ -57,9 +57,10 @@ pub fn is_64_bit(process: &Process) -> Option<bool> {
 }
 
 /// Finds the offset of a function in the bytes of a MachO file.
-pub fn get_function_offset<const N: usize>(macho_bytes: &[u8], function_name: &str) -> Option<u32> {
+pub fn get_function_offset(macho_bytes: &[u8], function_name: &[u8]) -> Option<u32> {
     let macho_offsets = MachOFormatOffsets::new();
     let number_of_commands: u32 = slice_read(macho_bytes, macho_offsets.number_of_commands).ok()?;
+    let function_name_len = function_name.len();
 
     let mut offset_to_next_command: usize = macho_offsets.load_commands as usize;
     for _i in 0..number_of_commands {
@@ -72,9 +73,10 @@ pub fn get_function_offset<const N: usize>(macho_bytes: &[u8], function_name: &s
 
             for j in 0..(number_of_symbols as usize) {
                 let symbol_name_offset: u32 = slice_read(macho_bytes, symbol_table_offset as usize + (j * macho_offsets.size_of_nlist_item)).ok()?;
-                let symbol_name: ArrayCString<N> = slice_read(macho_bytes, (string_table_offset + symbol_name_offset) as usize).ok()?;
+                let string_offset = string_table_offset as usize + symbol_name_offset as usize;
+                let symbol_name: &[u8] = &macho_bytes[string_offset..(string_offset + function_name_len + 1)];
 
-                if symbol_name.matches(function_name) {
+                if symbol_name[function_name_len] == 0 && symbol_name.starts_with(function_name) {
                     return Some(slice_read(macho_bytes, symbol_table_offset as usize + (j * macho_offsets.size_of_nlist_item) + macho_offsets.nlist_value).ok()?);
                 }
             }

src/game_engine/unity/mono.rs

@@ -147,9 +147,7 @@ impl Module {
         let mono_module_path = contents_path.join("Frameworks").join("libmonobdwgc-2.0.dylib");
         let mono_module_bytes = file_read_all_bytes(mono_module_path).ok()?;
 
-        const MONO_ASSEMBLY_FOREACH: &str = "_mono_assembly_foreach";
-        const MONO_ASSEMBLY_FOREACH_LEN_P1: usize = MONO_ASSEMBLY_FOREACH.len() + 1;
-        let mono_assembly_foreach_offset: u32 = macho::get_function_offset::<MONO_ASSEMBLY_FOREACH_LEN_P1>(&mono_module_bytes, MONO_ASSEMBLY_FOREACH)?;
+        let mono_assembly_foreach_offset: u32 = macho::get_function_offset(&mono_module_bytes, b"_mono_assembly_foreach")?;
 
         let function_array: [u8; 0x100] = macho::slice_read(&mono_module_bytes, mono_assembly_foreach_offset as usize).ok()?;
         let sig_function_array: Signature<0x100> = Signature::Simple(function_array);