1 files changed, 94 insertions, 0 deletions
diff --git a/third_party/rust/rlbox_lucet_sandbox/src/create.rs b/third_party/rust/rlbox_lucet_sandbox/src/create.rs
new file mode 100644
index 0000000000..e7701003e8
--- /dev/null
+++ b/third_party/rust/rlbox_lucet_sandbox/src/create.rs
@@ -0,0 +1,94 @@
+use crate::types::{Error, LucetSandboxInstance};
+
+use lucet_runtime::{DlModule, Limits, MmapRegion, Module, Region};
+use lucet_runtime_internals::{module::ModuleInternal};
+
+use lucet_wasi::WasiCtxBuilder;
+
+use std::ffi::{c_void, CStr};
+use std::os::raw::c_char;
+use std::ptr;
+use std::sync::Arc;
+
+#[no_mangle]
+pub extern "C" fn lucet_ensure_linked() {
+    lucet_runtime::lucet_internal_ensure_linked();
+    lucet_wasi::hostcalls::ensure_linked();
+}
+
+#[no_mangle]
+pub extern "C" fn lucet_load_module(lucet_module_path: *const c_char, allow_stdio: bool) -> *mut c_void {
+    let module_path;
+    unsafe {
+        module_path = CStr::from_ptr(lucet_module_path)
+            .to_string_lossy()
+            .into_owned();
+    }
+
+    let result = lucet_load_module_helper(&module_path, allow_stdio);
+
+    let r = match result {
+        Ok(inst) => Box::into_raw(Box::new(inst)) as *mut c_void,
+        Err(e) => {
+            println!("Error {:?}!", e);
+            ptr::null_mut()
+        }
+    };
+
+    return r;
+}
+
+#[no_mangle]
+pub extern "C" fn lucet_drop_module(inst_ptr: *mut c_void) {
+    // Need to invoke the destructor
+    let _inst = unsafe {
+        Box::from_raw(inst_ptr as *mut LucetSandboxInstance)
+    };
+
+}
+
+fn lucet_load_module_helper(module_path: &String, allow_stdio: bool) -> Result<LucetSandboxInstance, Error> {
+    let module = DlModule::load(module_path)?;
+
+    //Replicating calculations used in lucet examples
+    let min_globals_size = module.globals().len() * std::mem::size_of::<u64>();
+    // Nearest 4k
+    let globals_size = ((min_globals_size + 4096 - 1) / 4096) * 4096;
+
+    let region = MmapRegion::create_aligned(
+        1,
+        &Limits {
+            heap_memory_size: 4 * 1024 * 1024 * 1024,        // 4GB
+            heap_address_space_size: 8 * 1024 * 1024 * 1024, // 8GB
+            stack_size: 8 * 1024 * 1024,                     // 8MB - pthread default
+            globals_size: globals_size,
+            ..Limits::default()
+        },
+        4 * 1024 * 1024 * 1024,                              // 4GB heap alignment
+    )?;
+
+    let sig = module.get_signatures().to_vec();
+
+    // put the path to the module on the front for argv[0]
+    let mut builder = WasiCtxBuilder::new()
+        .args(&[&module_path]);
+
+    if allow_stdio {
+        builder = builder.inherit_stdio_no_syscall();
+    }
+
+    let ctx = builder.build()?;
+
+    let instance_handle = region
+        .new_instance_builder(module as Arc<dyn Module>)
+        .with_embed_ctx(ctx)
+        .build()?;
+
+    let opaque_instance = LucetSandboxInstance {
+        region: region,
+        instance_handle: instance_handle,
+        signatures: sig,
+    };
+
+    return Ok(opaque_instance);
+}