kwasmd.

Cargo.lock

@@ -2240,6 +2240,7 @@ dependencies = [
 name = "wasmer"
 version = "0.4.0"
 dependencies = [
+ "byteorder 1.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "errno 0.2.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "glob 0.2.11 (registry+https://github.com/rust-lang/crates.io-index)",
  "hashbrown 0.1.8 (registry+https://github.com/rust-lang/crates.io-index)",

Cargo.toml

@@ -19,6 +19,7 @@ include = [
 ]
 
 [dependencies]
+byteorder = "1.3.1"
 errno = "0.2.4"
 structopt = "0.2.11"
 wabt = "0.7.2"

lib/kwasm-loader/src/lib.rs

@@ -99,6 +99,14 @@ impl Instance for KernelInstance {
             entry_offset: self.offsets[id] as u32,
             params: &args,
         }).map_err(|x| format!("{:?}", x))?;
-        Ok(ret as u64)
+        Ok(ret)
+    }
+
+    fn read_memory(&mut self, offset: u32, len: u32) -> Result<Vec<u8>, String> {
+        self.context.read_memory(offset, len).map_err(|x| format!("{:?}", x))
+    }
+
+    fn write_memory(&mut self, offset: u32, len: u32, buf: &[u8]) -> Result<(), String> {
+        self.context.write_memory(offset, len, buf).map_err(|x| format!("{:?}", x))
     }
 }

lib/kwasm-loader/src/service.rs

@@ -17,6 +17,8 @@ macro_rules! impl_debug_display {
 pub enum Command {
     LoadCode = 0x1001,
     RunCode = 0x1002,
+    ReadMemory = 0x1003,
+    WriteMemory = 0x1004,
 }
 
 #[derive(Debug)]
@@ -67,6 +69,27 @@ struct RunCodeRequest {
     entry_offset: u32,
     params: *const u64,
     param_count: u32,
+    result: *mut RunCodeResult,
+}
+
+#[repr(C)]
+struct RunCodeResult {
+    success: u32,
+    retval: u64,
+}
+
+#[repr(C)]
+struct ReadMemoryRequest {
+    out: *mut u8,
+    offset: u32,
+    len: u32,
+}
+
+#[repr(C)]
+struct WriteMemoryRequest {
+    _in: *const u8,
+    offset: u32,
+    len: u32,
 }
 
 #[repr(C)]
@@ -144,20 +167,75 @@ impl ServiceContext {
         }
     }
 
-    pub fn run_code(&mut self, run: RunProfile) -> ServiceResult<i32> {
-        let req = RunCodeRequest {
+    pub fn run_code(&mut self, run: RunProfile) -> ServiceResult<u64> {
+        let mut result: RunCodeResult = unsafe { ::std::mem::zeroed() };
+        let mut req = RunCodeRequest {
             entry_offset: run.entry_offset,
             params: run.params.as_ptr(),
             param_count: run.params.len() as u32,
+            result: &mut result,
         };
         let fd = self.dev.as_raw_fd();
-        let ret = unsafe {
+        let err = unsafe {
             ::libc::ioctl(
                 fd,
                 Command::RunCode as i32 as ::libc::c_ulong,
+                &mut req as *mut _ as ::libc::c_ulong
+            )
+        };
+        if err < 0 {
+            Err(ServiceError::Code(err))
+        } else if result.success == 0 {
+            println!("Rejected {} {}", result.success, result.retval);
+            Err(ServiceError::Rejected)
+        } else {
+            Ok(result.retval)
+        }
+    }
+
+    pub fn read_memory(&mut self, offset: u32, len: u32) -> ServiceResult<Vec<u8>> {
+        let fd = self.dev.as_raw_fd();
+        let mut ret = Vec::with_capacity(len as usize);
+        unsafe {
+            ret.set_len(len as usize);
+        }
+        let req = ReadMemoryRequest {
+            out: ret.as_mut_ptr(),
+            offset: offset,
+            len: len,
+        };
+        let err = unsafe {
+            ::libc::ioctl(
+                fd,
+                Command::ReadMemory as i32 as ::libc::c_ulong,
                 &req as *const _ as ::libc::c_ulong
             )
         };
+        if err < 0 {
+            Err(ServiceError::Code(err))
+        } else {
             Ok(ret)
         }
     }
+
+    pub fn write_memory(&mut self, offset: u32, len: u32, buf: &[u8]) -> ServiceResult<()> {
+        let fd = self.dev.as_raw_fd();
+        let req = WriteMemoryRequest {
+            _in: buf.as_ptr(),
+            offset: offset,
+            len: len,
+        };
+        let err = unsafe {
+            ::libc::ioctl(
+                fd,
+                Command::WriteMemory as i32 as ::libc::c_ulong,
+                &req as *const _ as ::libc::c_ulong
+            )
+        };
+        if err < 0 {
+            Err(ServiceError::Code(err))
+        } else {
+            Ok(())
+        }
+    }
+}

lib/runtime-core/src/loader.rs

@@ -23,6 +23,13 @@ pub trait Loader {
 pub trait Instance {
     type Error: Debug;
     fn call(&mut self, id: usize, args: &[Value]) -> Result<u64, Self::Error>;
+    fn read_memory(&mut self, offset: u32, len: u32) -> Result<Vec<u8>, Self::Error> {
+        unimplemented!()
+    }
+
+    fn write_memory(&mut self, offset: u32, len: u32, buf: &[u8]) -> Result<(), Self::Error> {
+        unimplemented!()
+    }
 }
 
 pub struct LocalLoader;

src/bin/kwasmd.rs

@@ -0,0 +1,156 @@
+extern crate structopt;
+extern crate byteorder;
+
+use std::thread;
+use structopt::StructOpt;
+use wasmer::*;
+use wasmer_runtime::{
+    error::RuntimeError,
+    Func, Value,
+};
+use wasmer_runtime_core::{
+    self,
+    backend::{Compiler, CompilerConfig},
+    loader::{self, Loader, Instance as LoadedInstance, LocalLoader},
+};
+use wasmer_singlepass_backend::SinglePassCompiler;
+
+use std::os::unix::net::{UnixStream, UnixListener};
+use std::io::prelude::*;
+
+use byteorder::{LittleEndian, ReadBytesExt, WriteBytesExt};
+
+#[derive(Debug, StructOpt)]
+#[structopt(name = "kwasmd", about = "Kernel-mode WebAssembly service.")]
+enum CLIOptions {
+    #[structopt(name = "listen")]
+    Listen(Listen),
+}
+
+#[derive(Debug, StructOpt)]
+struct Listen {
+    #[structopt(long = "socket")]
+    socket: String,
+}
+
+const CMD_RUN_CODE: u32 = 0x901;
+const CMD_READ_MEMORY: u32 = 0x902;
+const CMD_WRITE_MEMORY: u32 = 0x903;
+
+fn handle_client(mut stream: UnixStream) {
+    let binary_size = stream.read_u32::<LittleEndian>().unwrap();
+    if binary_size > 1048576 * 16 {
+        println!("binary too large");
+        return;
+    }
+    let mut wasm_binary: Vec<u8> = Vec::with_capacity(binary_size as usize);
+    unsafe { wasm_binary.set_len(binary_size as usize) };
+    stream.read_exact(&mut wasm_binary).unwrap();
+    let module = webassembly::compile_with_config_with(
+        &wasm_binary[..],
+        CompilerConfig {
+            symbol_map: None,
+        },
+        &SinglePassCompiler::new(),
+    ).unwrap();
+
+    let mut import_object = wasmer_runtime_core::import::ImportObject::new();
+    import_object.allow_missing_functions = true; // Import initialization might be left to the loader.
+    let instance = module.instantiate(&import_object).unwrap();
+    let mut ins = instance.load(::kwasm_loader::KernelLoader).unwrap();
+
+    loop {
+        let cmd = stream.read_u32::<LittleEndian>().unwrap();
+        match cmd {
+            CMD_RUN_CODE => {
+                let func_name_len = stream.read_u32::<LittleEndian>().unwrap();
+                if func_name_len > 32 {
+                    println!("function name too long");
+                    return;
+                }
+                let mut func_name: Vec<u8> = Vec::with_capacity(func_name_len as usize);
+                unsafe { func_name.set_len(func_name_len as usize) };
+                stream.read_exact(&mut func_name).unwrap();
+                let func_name = ::std::str::from_utf8(&func_name).unwrap();
+                let arg_count = stream.read_u32::<LittleEndian>().unwrap();
+                if arg_count > 0 {
+                    println!("Too many arguments");
+                    return;
+                }
+                let mut args: Vec<Value> = Vec::with_capacity(arg_count as usize);
+                for _ in 0..arg_count {
+                    args.push(Value::I64(stream.read_u64::<LittleEndian>().unwrap() as _));
+                }
+
+                let index = instance.resolve_local_func(func_name).unwrap();
+                let ret = ins.call(index, &args);
+                match ret {
+                    Ok(x) => {
+                        stream.write_u32::<LittleEndian>(1).unwrap();
+                        stream.write_u64::<LittleEndian>(x).unwrap();
+                    },
+                    Err(e) => {
+                        println!("Execution error: {:?}", e);
+                        stream.write_u32::<LittleEndian>(0).unwrap();
+                    },
+                }
+            },
+            CMD_READ_MEMORY => {
+                let offset = stream.read_u32::<LittleEndian>().unwrap();
+                let len = stream.read_u32::<LittleEndian>().unwrap();
+                if len > 1048576 * 16 {
+                    println!("memory size too large");
+                    return;
+                }
+                let buf = ins.read_memory(offset, len).unwrap();
+                stream.write_all(&buf).unwrap();
+            },
+            CMD_WRITE_MEMORY => {
+                let offset = stream.read_u32::<LittleEndian>().unwrap();
+                let len = stream.read_u32::<LittleEndian>().unwrap();
+                if len > 1048576 * 16 {
+                    println!("memory size too large");
+                    return;
+                }
+                let mut buf: Vec<u8> = Vec::with_capacity(len as usize);
+                unsafe { buf.set_len(len as usize) };
+                stream.read_exact(&mut buf).unwrap();
+                ins.write_memory(offset, len, &buf).unwrap();
+            },
+            _ => {
+                println!("Unknown command");
+                return;
+            }
+        }
+    }
+}
+
+fn run_listen(opts: Listen) {
+    let listener = UnixListener::bind(&opts.socket).unwrap();
+    for stream in listener.incoming() {
+        match stream {
+            Ok(stream) => {
+                thread::spawn(|| {
+                    match ::std::panic::catch_unwind(::std::panic::AssertUnwindSafe(|| {
+                        handle_client(stream);
+                    })) {
+                        Ok(()) => {},
+                        Err(_) => {}
+                    }
+                });
+            }
+            Err(err) => {
+                panic!("{:?}", err);
+            }
+        }
+    }
+}
+
+fn main() {
+    let options = CLIOptions::from_args();
+    match options {
+        CLIOptions::Listen(listen) => {
+            run_listen(listen);
+        }
+    }
+}