1 files changed, 51 insertions, 0 deletions
diff --git a/third_party/rust/rlbox_lucet_sandbox/src/callback.rs b/third_party/rust/rlbox_lucet_sandbox/src/callback.rs
new file mode 100644
index 0000000000..b9f42aab47
--- /dev/null
+++ b/third_party/rust/rlbox_lucet_sandbox/src/callback.rs
@@ -0,0 +1,51 @@
+use crate::types::{LucetFunctionSignature, LucetSandboxInstance, SizedBuffer};
+
+use lucet_module::Signature;
+use lucet_runtime_internals::instance::InstanceInternal;
+
+use std::convert::TryFrom;
+use std::ffi::c_void;
+
+#[no_mangle]
+pub extern "C" fn lucet_get_reserved_callback_slot_val(
+    inst_ptr: *mut c_void,
+    slot_number: u32,
+) -> usize {
+    let inst = unsafe { &mut *(inst_ptr as *mut LucetSandboxInstance) };
+
+    let name = format!("sandboxReservedCallbackSlot{}", slot_number);
+    let func = inst
+        .instance_handle
+        .module()
+        .get_export_func(&name)
+        .unwrap();
+    return func.ptr.as_usize();
+}
+
+#[no_mangle]
+pub extern "C" fn lucet_get_function_pointer_table(inst_ptr: *mut c_void) -> SizedBuffer {
+    let inst = unsafe { &mut *(inst_ptr as *mut LucetSandboxInstance) };
+
+    let elems = inst.instance_handle.module().table_elements().unwrap();
+
+    SizedBuffer {
+        data: elems.as_ptr() as *mut c_void,
+        length: elems.len(),
+    }
+}
+
+#[no_mangle]
+pub extern "C" fn lucet_get_function_type_index(
+    inst_ptr: *mut c_void,
+    csig: LucetFunctionSignature,
+) -> i32 {
+    let inst = unsafe { &mut *(inst_ptr as *mut LucetSandboxInstance) };
+
+    let conv_sig: Signature = csig.into();
+    let index = inst.signatures.iter().position(|r| *r == conv_sig);
+
+    match index {
+        Some(x) => i32::try_from(x).unwrap_or(-1),
+        _ => -1,
+    }
+}