shebang loader

crates/vestal/Cargo.toml

@@ -9,4 +9,5 @@ goblin = "0.9.2"
 clap = { version = "4.5.4", features = [ "derive" ] }
 lancelot = "0.8.6"
 syscalls = "0.6.18"
+elf = "0.7.4"
 #falcon = "0.5.5"

crates/vestal/src/execute.rs

@@ -1,25 +1,68 @@
 use crate::*;
 use syscalls::{Sysno, syscall};
-static NAME: &'static [char] = &['\0'];
+use elf::file::Elf64_Ehdr;
+use std::ffi::CString;
+use std::str::FromStr;
+static NAME: &'static [u8] = &[b'\0'];
 impl Vestal {
-    pub fn execute (&self, path: impl AsRef<Path>) -> Usually<()> {
-        Self::with_pe(&path, |buffer, pe, main, deps|{
-            let fd = Self::get_fd();
-            // TODO: compose in-memory ELF binary out of PE sections and Wine libraries
-            Self::write(fd, buffer);
-            println!("{fd}");
+    pub fn execute_data (&self, data: &[u8]) -> Usually<()> {
+        Ok(())
+    }
+    pub fn execute_path (&self, path: impl AsRef<Path>) -> Usually<()> {
+        Self::from_path(&path, |buffer, pe, main, deps|{
+            if let Some(main) = main {
+                println!("VSTPluginMain: {:?} + {:?}", &main.rva, &main.offset);
+            } else {
+                panic!("VSTPluginMain not found. This is not a valid VST plugin.");
+            }
+            println!("Imports: {:#?}", &pe.imports.len());
+            println!("Dependencies: {:#?}", &deps.len());
+            for (dll, imports) in deps.iter() {
+                println!("- {dll}");
+                for import in imports.iter() {
+                    println!("    {:8} + {:8}  {:32}", import.rva, import.offset, import.name);
+                }
+            }
         })
     }
-    fn get_fd () -> usize {
-        match unsafe { syscall!(Sysno::memfd_create, NAME.as_ptr(), 0x0001, 0) } {
-            Err(no) => panic!("memfd_create failed: {no}"),
-            Ok(fd) => fd,
-        }
-    }
-    fn write (fd: usize, buffer: &[u8]) {
-        match unsafe { syscall!(Sysno::write, fd, buffer.as_ptr()) } {
-            Err(no) => panic!("write failed: {no}"),
-            Ok(_) => (),
-        }
+}
+fn make_elf () -> Vec<u8> {
+    let mut buffer = vec![0;1024*1024*1024];
+    // https://wiki.osdev.org/ELF#ELF_Header
+    buffer[0x00..0x40].copy_from_slice(any_as_u8_slice(&Elf64_Ehdr {
+        e_ehsize: 0x40, // elf header size,
+        e_ident: [ // identification data
+            0x7f, b'E', b'L', b'F', // magic bytes
+            0x02, // 64-bit, 0x01 is 32-bit
+            0x01, // little-endian
+            0x01, // ELF header version
+            0x00, // SysV ABI
+            0x00, 0x00, 0x00, 0x00, // unused
+            0x00, 0x00, 0x00, 0x00, // unused
+        ],
+        e_version:   0x01, // ELF version
+        e_type:      0x02, // executable
+        e_machine:   0x3e, // x86_64, 0x03 = x86
+        e_flags:     0x00, // TODO machine flags,
+        e_entry:     0x00, // TODO entry point (from wrapper?)
+
+        e_phnum:     0x00, // TODO program headers
+        e_phentsize: 0x00, // TODO why is there phent in my elf?
+        e_phoff:     0x00, // TODO program header table offset
+
+        e_shnum:     0x00, // TODO section headers
+        e_shentsize: 0x00, // TODO section header entry size
+        e_shoff:     0x00, // TODO section header table offset
+        e_shstrndx:  0x00, // TODO section header table index something something
+    }));
+    buffer
+}
+/// From https://stackoverflow.com/a/42186553
+fn any_as_u8_slice<T: Sized>(p: &T) -> &[u8] {
+    unsafe {
+        ::core::slice::from_raw_parts(
+            (p as *const T) as *const u8,
+            ::core::mem::size_of::<T>(),
+        )
     }
 }

crates/vestal/src/inspect.rs

@@ -1,8 +1,9 @@
 use crate::*;
 
 impl Vestal {
-    pub fn inspect (&self, path: impl AsRef<Path>) -> Usually<()> {
-        Self::with_pe(&path, |buffer, pe, main, deps|{
+    pub fn inspect_data (&self, path: impl AsRef<Path>) -> Usually<()> { Ok(()) }
+    pub fn inspect_path (&self, path: impl AsRef<Path>) -> Usually<()> {
+        Self::from_path(&path, |buffer, pe, main, deps|{
             if let Some(main) = main {
                 println!("VSTPluginMain: {:?} + {:?}", &main.rva, &main.offset);
             } else {

crates/vestal/src/main.rs

@@ -1,5 +1,7 @@
 mod execute;
 mod inspect;
+mod memrun;
+mod parse;
 pub(crate) use std::path::Path;
 pub(crate) use goblin::{error, Object, pe::{PE, import::Import, export::Export}};
 use std::collections::HashMap;
@@ -18,22 +20,37 @@ pub enum Vestal {
     Inspect { path: String },
     /// Load a VST DLL into memory
     Execute { path: String },
+    /// Load a VST DLL from hashbang
+    Loader  { path: String }
+}
+
+pub enum Arch {
+    ThirtyTwo,
+    SixtyFour,
 }
 
 impl Vestal {
     pub fn run (&self) -> Usually<()> {
         match self {
-            Self::Inspect { path } => self.inspect(path.as_str()),
-            Self::Execute { path } => self.execute(path.as_str()),
+            Self::Inspect { path } => self.inspect_path(path.as_str()),
+            Self::Execute { path } => self.execute_path(path.as_str()),
+            Self::Loader  { path } => self.execute_path(path.as_str()),
         }
     }
-    pub fn with_pe (
+    pub fn with_path (
         path: &impl AsRef<Path>,
         cb:   impl Fn(&[u8], &PE, Option<&Export>, HashMap<String, Vec<&Import>>)
     ) -> Usually<()> {
-        println!("PE: {}", path.as_ref().display());
+        println!("Path: {}", path.as_ref().display());
         let buffer = std::fs::read(path.as_ref())?;
-        if let Object::PE(ref pe) = Object::parse(&buffer)? {
+        Self::with_data(buffer.as_slice(), cb)
+    }
+    pub fn with_data (
+        buffer: &[u8],
+        callback: impl Fn(&[u8], &PE, Option<&Export>, HashMap<String, Vec<&Import>>)
+    ) -> Usually<()> {
+        println!("PE: {}b", buffer.len());
+        if let Object::PE(ref pe) = Object::parse(buffer)? {
             let mut main = None;
             let mut imports: HashMap<_, _> = Default::default();
             for import in pe.imports.iter() {
@@ -50,7 +67,7 @@ impl Vestal {
                     break
                 }
             }
-            cb(&buffer, pe, main, imports);
+            callback(&buffer, pe, main, imports);
             Ok(())
         } else {
             Err("not a PE".into())

crates/vestal/src/memrun.rs

@@ -0,0 +1,57 @@
+use std::fmt::{Debug, Display};
+use syscalls::{Sysno, Errno, syscall};
+
+static EMPTY: &'static [u8] = &[b'\0'];
+static CMD:   &'static [u8] = &[b'/',b'p',b'r',b'o',b'c',b'/',b's',b'e',b'l',b'f',b'/',b'f',b'd',b'/',b'3',b'\0'];
+static ARGS:  &'static [u8] = &[b'\0',b'\0'];
+static ENVS:  &'static [u8] = &[b'\0'];
+
+pub struct MemRun(usize);
+
+#[derive(Debug)]
+pub enum MemRunError {
+    MemfdCreateFailed(Errno),
+    ExecveFailed(Errno),
+}
+
+impl MemRun {
+    pub fn new () -> Result<Self, MemRunError> {
+        unsafe { syscall!(Sysno::memfd_create, EMPTY.as_ptr(), 0x0001, 0) }
+            .map_err(MemRunError::MemfdCreateFailed)
+            .map(Self)
+    }
+    pub fn run (code: &[u8]) -> Result<(), MemRunError> {
+        let cmd = b"/proc/self/fd/3\0";
+        let arg = [b"custom process name\0"];
+        let env = [b"\0"];
+        unsafe { syscall!(Sysno::execve, CMD.as_ptr(), ARGS.as_ptr(), ENVS.as_ptr()) }
+            .map_err(MemRunError::ExecveFailed)
+            .map(|_|())
+    }
+}
+
+// From https://github.com/guitmz/memrun/
+fn get_fd () -> usize {
+    match unsafe { syscall!(Sysno::memfd_create, EMPTY.as_ptr(), 0x0001, 0) } {
+        Err(no) => panic!("memfd_create failed: {no}"),
+        Ok(fd) => fd,
+    }
+}
+// From https://github.com/guitmz/memrun/
+fn write (fd: usize, buffer: &[u8]) {
+    match unsafe { syscall!(Sysno::write, fd, buffer.as_ptr()) } {
+        Err(no) => panic!("write failed: {no}"),
+        Ok(_) => (),
+    }
+}
+// From https://github.com/guitmz/memrun/
+fn run (fd: usize) {
+    println!("fd = {fd}");
+    let cmd = b"/proc/self/fd/3\0";
+    let arg = [b"it is i, leclerc\0"];
+    let env = [b"\0"];
+    match unsafe { syscall!(Sysno::execve, cmd.as_ptr(), arg.as_ptr(), env.as_ptr()) } {
+        Err(no) => panic!("write failed: {no}"),
+        Ok(_) => (),
+    }
+}

crates/vestal/src/parse.rs

@@ -0,0 +1,54 @@
+use crate::*;
+impl Vestal {
+
+    pub fn from_path (
+        path: &impl AsRef<Path>,
+        cb:   impl Fn(&[u8], &PE, Option<&Export>, HashMap<String, Vec<&Import>>)
+    ) -> Usually<()> {
+        println!("Path: {}", path.as_ref().display());
+        let buffer = std::fs::read(path.as_ref())?;
+        Self::from_data(buffer.as_slice(), cb)
+    }
+
+    pub fn from_data (
+        mut buffer: &[u8],
+        callback: impl Fn(&[u8], &PE, Option<&Export>, HashMap<String, Vec<&Import>>)
+    ) -> Usually<()> {
+        println!("PE: {}b", buffer.len());
+        let mut index = 2;
+        let mut slice = false;
+        if buffer.get(0) == Some(&b'#') && buffer.get(1) == Some(&b'!') {
+            while let Some(c) = buffer.get(index) {
+                if *c == 0x0a {
+                    slice = true;
+                    break
+                }
+                index += 1;
+            }
+        }
+        println!("Slice: {slice} {index}");
+        let buffer = if slice { &buffer[index+1..] } else { buffer };
+        if let Object::PE(ref pe) = Object::parse(buffer)? {
+            let mut main = None;
+            let mut imports: HashMap<_, _> = Default::default();
+            for import in pe.imports.iter() {
+                let dll = import.dll.clone();
+                if !imports.contains_key(dll) {
+                    imports.insert(dll.to_string(), vec![]);
+                }
+                imports.get_mut(dll).unwrap().push(import);
+            }
+            for export in pe.exports.iter() {
+                if let Some("VSTPluginMain") = export.name {
+                    main = Some(export);
+                    break
+                }
+            }
+            callback(&buffer, pe, main, imports);
+            Ok(())
+        } else {
+            Err("not a PE".into())
+        }
+    }
+
+}