Merge pull request #4472 from OffchainLabs/pmikolajczyk/nit-4614-port-wavmio

Move wavmio logic to caller-env

Author: eljobe

Cargo.lock

@@ -55,7 +55,7 @@ enum-iterator = { version = "2.0.1" }
 eyre = { version = "0.6.5" }
 fnv = { version = "1.0.7" }
 gperftools = { version = "0.2.0" }
-hex = { version = "0.4.3" }
+hex = { version = "0.4.3", default-features = false }
 k256 = { version = "0.13.4", default-features = false}
 lazy_static = { version = "1.4.0" }
 libc = { version = "0.2.132" }

Cargo.toml

@@ -0,0 +1,2 @@
+### Internal
+ - Move wavmio logic from JIT crate to caller-env (to be reused soon by SP1 validator)

changelog/pmikolajczyk-nit-4614.md

@@ -11,6 +11,7 @@ rust-version.workspace = true
 
 [dependencies]
 brotli = { workspace = true, optional = true }
+hex = { workspace = true, features = ["alloc"] }
 k256 = { workspace = true, features = ["ecdsa"] }
 rand = { workspace = true }
 rand_pcg = { workspace = true }

crates/caller-env/Cargo.toml

@@ -21,6 +21,7 @@ pub mod wasmer_traits;
 pub mod brotli;
 
 pub mod arbcrypto;
+pub mod wavmio;
 
 mod guest_ptr;
 pub mod wasip1_stub;

crates/caller-env/src/lib.rs

@@ -0,0 +1,147 @@
+// Copyright 2026, Offchain Labs, Inc.
+// For license information, see https://github.com/OffchainLabs/nitro/blob/master/LICENSE.md
+
+use crate::{GuestPtr, MemAccess};
+use alloc::format;
+use alloc::string::String;
+use core::cmp::min;
+
+/// Read validation inputs and set outputs for the `wavmio` host functions.
+pub trait WavmIo {
+    fn get_u64_global(&self, idx: usize) -> Option<u64>;
+    fn set_u64_global(&mut self, idx: usize, val: u64) -> bool;
+    fn get_bytes32_global(&self, idx: usize) -> Option<&[u8; 32]>;
+    fn set_bytes32_global(&mut self, idx: usize, val: [u8; 32]) -> bool;
+    fn get_sequencer_message(&self, num: u64) -> Option<&[u8]>;
+    fn get_delayed_message(&self, num: u64) -> Option<&[u8]>;
+    fn get_preimage(&self, preimage_type: u8, hash: &[u8; 32]) -> Option<&[u8]>;
+}
+
+/// Reads 32-bytes of global state and writes to guest memory.
+pub fn get_global_state_bytes32(
+    mem: &mut impl MemAccess,
+    io: &impl WavmIo,
+    idx: u32,
+    out_ptr: GuestPtr,
+) -> Result<(), String> {
+    let Some(global) = io.get_bytes32_global(idx as usize) else {
+        return Err("global read out of bounds in wavmio.getGlobalStateBytes32".into());
+    };
+    mem.write_slice(out_ptr, &global[..]);
+    Ok(())
+}
+
+/// Reads 32-bytes from guest memory and writes to global state.
+pub fn set_global_state_bytes32(
+    mem: &impl MemAccess,
+    io: &mut impl WavmIo,
+    idx: u32,
+    src_ptr: GuestPtr,
+) -> Result<(), String> {
+    let val = mem.read_fixed(src_ptr);
+    if !io.set_bytes32_global(idx as usize, val) {
+        return Err("global write oob in wavmio.setGlobalStateBytes32".into());
+    }
+    Ok(())
+}
+
+/// Reads 8-bytes of global state.
+pub fn get_global_state_u64(io: &impl WavmIo, idx: u32) -> Result<u64, String> {
+    match io.get_u64_global(idx as usize) {
+        Some(val) => Ok(val),
+        None => Err("global read out of bounds in wavmio.getGlobalStateU64".into()),
+    }
+}
+
+/// Writes 8-bytes of global state.
+pub fn set_global_state_u64(io: &mut impl WavmIo, idx: u32, val: u64) -> Result<(), String> {
+    if !io.set_u64_global(idx as usize, val) {
+        return Err("global write out of bounds in wavmio.setGlobalStateU64".into());
+    }
+    Ok(())
+}
+
+/// Reads up to 32 bytes of a sequencer inbox message at the given offset.
+pub fn read_inbox_message(
+    mem: &mut impl MemAccess,
+    io: &impl WavmIo,
+    msg_num: u64,
+    offset: u32,
+    out_ptr: GuestPtr,
+) -> Result<u32, String> {
+    let message = io
+        .get_sequencer_message(msg_num)
+        .ok_or(format!("missing sequencer inbox message {msg_num}"))?;
+    read_message(mem, message, offset, out_ptr)
+}
+
+/// Reads up to 32 bytes of a delayed inbox message at the given offset.
+pub fn read_delayed_inbox_message(
+    mem: &mut impl MemAccess,
+    io: &impl WavmIo,
+    msg_num: u64,
+    offset: u32,
+    out_ptr: GuestPtr,
+) -> Result<u32, String> {
+    let message = io
+        .get_delayed_message(msg_num)
+        .ok_or(format!("missing delayed inbox message {msg_num}"))?;
+    read_message(mem, message, offset, out_ptr)
+}
+
+fn read_message(
+    mem: &mut impl MemAccess,
+    message: &[u8],
+    offset: u32,
+    out_ptr: GuestPtr,
+) -> Result<u32, String> {
+    let offset = offset as usize;
+    let len = min(32, message.len().saturating_sub(offset));
+    let read = message.get(offset..(offset + len)).unwrap_or_default();
+    mem.write_slice(out_ptr, read);
+    Ok(read.len() as u32)
+}
+
+/// Looks up a preimage by type and hash, reads up to 32 bytes at an aligned offset.
+pub fn resolve_preimage(
+    mem: &mut impl MemAccess,
+    io: &impl WavmIo,
+    preimage_type: u8,
+    hash_ptr: GuestPtr,
+    offset: u32,
+    out_ptr: GuestPtr,
+    name: &str,
+) -> Result<u32, String> {
+    let hash = mem.read_fixed(hash_ptr);
+    let offset = offset as usize;
+
+    let Some(preimage) = io.get_preimage(preimage_type, &hash) else {
+        let hash_hex = hex::encode(hash);
+        return Err(format!(
+            "Missing requested preimage for hash {hash_hex} in {name}"
+        ));
+    };
+
+    if offset % 32 != 0 {
+        return Err(format!("bad offset {offset} in {name}"));
+    }
+
+    let len = min(32, preimage.len().saturating_sub(offset));
+    let read = preimage.get(offset..(offset + len)).unwrap_or_default();
+    mem.write_slice(out_ptr, read);
+    Ok(read.len() as u32)
+}
+
+/// Returns 1 if a preimage exists for the given type and hash, 0 otherwise.
+pub fn validate_certificate(
+    mem: &impl MemAccess,
+    io: &impl WavmIo,
+    preimage_type: u8,
+    hash_ptr: GuestPtr,
+) -> u8 {
+    let hash = mem.read_fixed(hash_ptr);
+    match io.get_preimage(preimage_type, &hash) {
+        Some(_) => 1,
+        None => 0,
+    }
+}

crates/caller-env/src/wavmio.rs

@@ -3,7 +3,7 @@
 
 use crate::machine::{WasmEnv, WasmEnvMut};
 use arbutil::{Bytes20, Bytes32};
-use caller_env::{ExecEnv, GuestPtr, MemAccess};
+use caller_env::{wavmio::WavmIo, ExecEnv, GuestPtr, MemAccess};
 use rand::RngCore;
 use std::mem::{self, MaybeUninit};
 use wasmer::{Memory, MemoryView, StoreMut, WasmPtr};
@@ -132,3 +132,48 @@ impl ExecEnv for JitExecEnv<'_> {
         }
     }
 }
+
+impl WavmIo for WasmEnv {
+    fn get_u64_global(&self, idx: usize) -> Option<u64> {
+        self.small_globals.get(idx).copied()
+    }
+
+    fn set_u64_global(&mut self, idx: usize, val: u64) -> bool {
+        let Some(g) = self.small_globals.get_mut(idx) else {
+            return false;
+        };
+        *g = val;
+        true
+    }
+
+    fn get_bytes32_global(&self, idx: usize) -> Option<&[u8; 32]> {
+        self.large_globals.get(idx).map(|b| &b.0)
+    }
+
+    fn set_bytes32_global(&mut self, idx: usize, val: [u8; 32]) -> bool {
+        let Some(g) = self.large_globals.get_mut(idx) else {
+            return false;
+        };
+        *g = val.into();
+        true
+    }
+
+    fn get_sequencer_message(&self, num: u64) -> Option<&[u8]> {
+        self.sequencer_messages.get(&num).map(|v| v.as_slice())
+    }
+
+    fn get_delayed_message(&self, num: u64) -> Option<&[u8]> {
+        self.delayed_messages.get(&num).map(|v| v.as_slice())
+    }
+
+    fn get_preimage(&self, preimage_type: u8, hash: &[u8; 32]) -> Option<&[u8]> {
+        let Ok(pt) = preimage_type.try_into() else {
+            eprintln!("Go trying to get a preimage with unknown type {preimage_type}");
+            return None;
+        };
+        self.preimages
+            .get(&pt)
+            .and_then(|m| m.get(&Bytes32(*hash)))
+            .map(|v| v.as_slice())
+    }
+}